1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
49 * follow IFS rules more precisely, including update semantics
50 * builtins mandated by standards we don't support:
51 * [un]alias, command, fc, getopts, newgrp, readonly, times
52 * make complex ${var%...} constructs support optional
53 * make here documents optional
56 * redirection of stdout+stderr: &> and >&
57 * reserved words: function select
58 * advanced test: [[ ]]
59 * process substitution: <(list) and >(list)
62 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
63 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
64 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
66 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
67 * This is exactly equivalent to let "EXPR".
68 * $[EXPR]: synonym for $((EXPR))
71 * In bash, export builtin is special, its arguments are assignments
72 * and therefore expansion of them should be "one-word" expansion:
73 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
75 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
76 * ls: cannot access i=a: No such file or directory
77 * ls: cannot access b: No such file or directory
78 * Note1: same applies to local builtin.
79 * Note2: bash 3.2.33(1) does this only if export word itself
81 * $ export i=`echo 'aaa bbb'`; echo "$i"
83 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
86 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
87 || defined(__APPLE__) \
89 # include <malloc.h> /* for malloc_trim */
92 /* #include <dmalloc.h> */
96 #include <sys/utsname.h> /* for setting $HOSTNAME */
98 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
100 #include "shell_common.h"
103 #if ENABLE_HUSH_RANDOM_SUPPORT
106 # define CLEAR_RANDOM_T(rnd) ((void)0)
108 #ifndef F_DUPFD_CLOEXEC
109 # define F_DUPFD_CLOEXEC F_DUPFD
112 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
116 //config: bool "hush"
119 //config: hush is a small shell (25k). It handles the normal flow control
120 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
121 //config: case/esac. Redirections, here documents, $((arithmetic))
122 //config: and functions are supported.
124 //config: It will compile and work on no-mmu systems.
126 //config: It does not handle select, aliases, tilde expansion,
127 //config: &>file and >&file redirection of stdout+stderr.
129 //config:config HUSH_BASH_COMPAT
130 //config: bool "bash-compatible extensions"
132 //config: depends on HUSH
134 //config: Enable bash-compatible extensions.
136 //config:config HUSH_BRACE_EXPANSION
137 //config: bool "Brace expansion"
139 //config: depends on HUSH_BASH_COMPAT
141 //config: Enable {abc,def} extension.
143 //config:config HUSH_HELP
144 //config: bool "help builtin"
146 //config: depends on HUSH
148 //config: Enable help builtin in hush. Code size + ~1 kbyte.
150 //config:config HUSH_INTERACTIVE
151 //config: bool "Interactive mode"
153 //config: depends on HUSH
155 //config: Enable interactive mode (prompt and command editing).
156 //config: Without this, hush simply reads and executes commands
157 //config: from stdin just like a shell script from a file.
158 //config: No prompt, no PS1/PS2 magic shell variables.
160 //config:config HUSH_SAVEHISTORY
161 //config: bool "Save command history to .hush_history"
163 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
165 //config: Enable history saving in hush.
167 //config:config HUSH_JOB
168 //config: bool "Job control"
170 //config: depends on HUSH_INTERACTIVE
172 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
173 //config: command (not entire shell), fg/bg builtins work. Without this option,
174 //config: "cmd &" still works by simply spawning a process and immediately
175 //config: prompting for next command (or executing next command in a script),
176 //config: but no separate process group is formed.
178 //config:config HUSH_TICK
179 //config: bool "Process substitution"
181 //config: depends on HUSH
183 //config: Enable process substitution `command` and $(command) in hush.
185 //config:config HUSH_IF
186 //config: bool "Support if/then/elif/else/fi"
188 //config: depends on HUSH
190 //config: Enable if/then/elif/else/fi in hush.
192 //config:config HUSH_LOOPS
193 //config: bool "Support for, while and until loops"
195 //config: depends on HUSH
197 //config: Enable for, while and until loops in hush.
199 //config:config HUSH_CASE
200 //config: bool "Support case ... esac statement"
202 //config: depends on HUSH
204 //config: Enable case ... esac statement in hush. +400 bytes.
206 //config:config HUSH_FUNCTIONS
207 //config: bool "Support funcname() { commands; } syntax"
209 //config: depends on HUSH
211 //config: Enable support for shell functions in hush. +800 bytes.
213 //config:config HUSH_LOCAL
214 //config: bool "Support local builtin"
216 //config: depends on HUSH_FUNCTIONS
218 //config: Enable support for local variables in functions.
220 //config:config HUSH_RANDOM_SUPPORT
221 //config: bool "Pseudorandom generator and $RANDOM variable"
223 //config: depends on HUSH
225 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
226 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
228 //config:config HUSH_EXPORT_N
229 //config: bool "Support 'export -n' option"
231 //config: depends on HUSH
233 //config: export -n unexports variables. It is a bash extension.
235 //config:config HUSH_MODE_X
236 //config: bool "Support 'hush -x' option and 'set -x' command"
238 //config: depends on HUSH
240 //config: This instructs hush to print commands before execution.
241 //config: Adds ~300 bytes.
244 //config: bool "msh (deprecated: aliased to hush)"
246 //config: select HUSH
248 //config: msh is deprecated and will be removed, please migrate to hush.
251 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
252 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
253 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
254 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
256 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
257 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
259 /* -i (interactive) and -s (read stdin) are also accepted,
260 * but currently do nothing, therefore aren't shown in help.
261 * NOMMU-specific options are not meant to be used by users,
262 * therefore we don't show them either.
264 //usage:#define hush_trivial_usage
265 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
266 //usage:#define hush_full_usage "\n\n"
267 //usage: "Unix shell interpreter"
269 //usage:#define msh_trivial_usage hush_trivial_usage
270 //usage:#define msh_full_usage hush_full_usage
272 //usage:#if ENABLE_FEATURE_SH_IS_HUSH
273 //usage:# define sh_trivial_usage hush_trivial_usage
274 //usage:# define sh_full_usage hush_full_usage
276 //usage:#if ENABLE_FEATURE_BASH_IS_HUSH
277 //usage:# define bash_trivial_usage hush_trivial_usage
278 //usage:# define bash_full_usage hush_full_usage
283 #define LEAK_HUNTING 0
284 #define BUILD_AS_NOMMU 0
285 /* Enable/disable sanity checks. Ok to enable in production,
286 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
287 * Keeping 1 for now even in released versions.
290 /* Slightly bigger (+200 bytes), but faster hush.
291 * So far it only enables a trick with counting SIGCHLDs and forks,
292 * which allows us to do fewer waitpid's.
293 * (we can detect a case where neither forks were done nor SIGCHLDs happened
294 * and therefore waitpid will return the same result as last time)
296 #define ENABLE_HUSH_FAST 0
297 /* TODO: implement simplified code for users which do not need ${var%...} ops
298 * So far ${var%...} ops are always enabled:
300 #define ENABLE_HUSH_DOLLAR_OPS 1
305 # undef USE_FOR_NOMMU
308 # define USE_FOR_NOMMU(...) __VA_ARGS__
309 # define USE_FOR_MMU(...)
312 #include "NUM_APPLETS.h"
314 /* STANDALONE does not make sense, and won't compile */
315 # undef CONFIG_FEATURE_SH_STANDALONE
316 # undef ENABLE_FEATURE_SH_STANDALONE
317 # undef IF_FEATURE_SH_STANDALONE
318 # undef IF_NOT_FEATURE_SH_STANDALONE
319 # define ENABLE_FEATURE_SH_STANDALONE 0
320 # define IF_FEATURE_SH_STANDALONE(...)
321 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
324 #if !ENABLE_HUSH_INTERACTIVE
325 # undef ENABLE_FEATURE_EDITING
326 # define ENABLE_FEATURE_EDITING 0
327 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
328 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
329 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
330 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
333 /* Do we support ANY keywords? */
334 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
335 # define HAS_KEYWORDS 1
336 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
337 # define IF_HAS_NO_KEYWORDS(...)
339 # define HAS_KEYWORDS 0
340 # define IF_HAS_KEYWORDS(...)
341 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
344 /* If you comment out one of these below, it will be #defined later
345 * to perform debug printfs to stderr: */
346 #define debug_printf(...) do {} while (0)
347 /* Finer-grained debug switches */
348 #define debug_printf_parse(...) do {} while (0)
349 #define debug_print_tree(a, b) do {} while (0)
350 #define debug_printf_exec(...) do {} while (0)
351 #define debug_printf_env(...) do {} while (0)
352 #define debug_printf_jobs(...) do {} while (0)
353 #define debug_printf_expand(...) do {} while (0)
354 #define debug_printf_varexp(...) do {} while (0)
355 #define debug_printf_glob(...) do {} while (0)
356 #define debug_printf_list(...) do {} while (0)
357 #define debug_printf_subst(...) do {} while (0)
358 #define debug_printf_clean(...) do {} while (0)
360 #define ERR_PTR ((void*)(long)1)
362 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
364 #define _SPECIAL_VARS_STR "_*@$!?#"
365 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
366 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
367 #if ENABLE_HUSH_BASH_COMPAT
368 /* Support / and // replace ops */
369 /* Note that // is stored as \ in "encoded" string representation */
370 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
371 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
372 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
374 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
375 # define VAR_SUBST_OPS "%#:-=+?"
376 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
379 #define SPECIAL_VAR_SYMBOL 3
383 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
385 /* This supports saving pointers malloced in vfork child,
386 * to be freed in the parent.
389 typedef struct nommu_save_t {
391 struct variable *old_vars;
393 char **argv_from_re_execing;
406 #if ENABLE_HUSH_LOOPS
413 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
418 /* three pseudo-keywords support contrived "case" syntax: */
419 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
420 RES_MATCH , /* "word)" */
421 RES_CASE_BODY, /* "this command is inside CASE" */
428 typedef struct o_string {
430 int length; /* position where data is appended */
433 /* At least some part of the string was inside '' or "",
434 * possibly empty one: word"", wo''rd etc. */
435 smallint has_quoted_part;
436 smallint has_empty_slot;
437 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
440 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
442 /* Protect newly added chars against globbing
443 * by prepending \ to *, ?, [, \ */
444 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
447 MAYBE_ASSIGNMENT = 0,
448 DEFINITELY_ASSIGNMENT = 1,
450 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
453 /* Used for initialization: o_string foo = NULL_O_STRING; */
454 #define NULL_O_STRING { NULL }
456 #ifndef debug_printf_parse
457 static const char *const assignment_flag[] = {
459 "DEFINITELY_ASSIGNMENT",
465 typedef struct in_str {
467 #if ENABLE_HUSH_INTERACTIVE
468 smallint promptmode; /* 0: PS1, 1: PS2 */
473 int (*get) (struct in_str *) FAST_FUNC;
474 int (*peek) (struct in_str *) FAST_FUNC;
476 #define i_getch(input) ((input)->get(input))
477 #define i_peek(input) ((input)->peek(input))
479 /* The descrip member of this structure is only used to make
480 * debugging output pretty */
481 static const struct {
483 signed char default_fd;
486 { O_RDONLY, 0, "<" },
487 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
488 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
489 { O_CREAT|O_RDWR, 1, "<>" },
490 { O_RDONLY, 0, "<<" },
491 /* Should not be needed. Bogus default_fd helps in debugging */
492 /* { O_RDONLY, 77, "<<" }, */
495 struct redir_struct {
496 struct redir_struct *next;
497 char *rd_filename; /* filename */
498 int rd_fd; /* fd to redirect */
499 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
501 smallint rd_type; /* (enum redir_type) */
502 /* note: for heredocs, rd_filename contains heredoc delimiter,
503 * and subsequently heredoc itself; and rd_dup is a bitmask:
504 * bit 0: do we need to trim leading tabs?
505 * bit 1: is heredoc quoted (<<'delim' syntax) ?
508 typedef enum redir_type {
510 REDIRECT_OVERWRITE = 1,
513 REDIRECT_HEREDOC = 4,
514 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
517 REDIRFD_SYNTAX_ERR = -2,
518 REDIRFD_TO_FILE = -1,
519 /* otherwise, rd_fd is redirected to rd_dup */
521 HEREDOC_SKIPTABS = 1,
527 pid_t pid; /* 0 if exited */
528 int assignment_cnt; /* how many argv[i] are assignments? */
529 smallint cmd_type; /* CMD_xxx */
531 #define CMD_SUBSHELL 1
532 #if ENABLE_HUSH_BASH_COMPAT
533 /* used for "[[ EXPR ]]" */
534 # define CMD_SINGLEWORD_NOGLOB 2
536 #if ENABLE_HUSH_FUNCTIONS
537 # define CMD_FUNCDEF 3
540 smalluint cmd_exitcode;
541 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
544 char *group_as_string;
546 #if ENABLE_HUSH_FUNCTIONS
547 struct function *child_func;
548 /* This field is used to prevent a bug here:
549 * while...do f1() {a;}; f1; f1() {b;}; f1; done
550 * When we execute "f1() {a;}" cmd, we create new function and clear
551 * cmd->group, cmd->group_as_string, cmd->argv[0].
552 * When we execute "f1() {b;}", we notice that f1 exists,
553 * and that its "parent cmd" struct is still "alive",
554 * we put those fields back into cmd->xxx
555 * (struct function has ->parent_cmd ptr to facilitate that).
556 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
557 * Without this trick, loop would execute a;b;b;b;...
558 * instead of correct sequence a;b;a;b;...
559 * When command is freed, it severs the link
560 * (sets ->child_func->parent_cmd to NULL).
563 char **argv; /* command name and arguments */
564 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
565 * and on execution these are substituted with their values.
566 * Substitution can make _several_ words out of one argv[n]!
567 * Example: argv[0]=='.^C*^C.' here: echo .$*.
568 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
570 struct redir_struct *redirects; /* I/O redirections */
572 /* Is there anything in this command at all? */
573 #define IS_NULL_CMD(cmd) \
574 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
578 int num_cmds; /* total number of commands in pipe */
579 int alive_cmds; /* number of commands running (not exited) */
580 int stopped_cmds; /* number of commands alive, but stopped */
582 int jobid; /* job number */
583 pid_t pgrp; /* process group ID for the job */
584 char *cmdtext; /* name of job */
586 struct command *cmds; /* array of commands in pipe */
587 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
588 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
589 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
591 typedef enum pipe_style {
597 /* Is there anything in this pipe at all? */
598 #define IS_NULL_PIPE(pi) \
599 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
601 /* This holds pointers to the various results of parsing */
602 struct parse_context {
603 /* linked list of pipes */
604 struct pipe *list_head;
605 /* last pipe (being constructed right now) */
607 /* last command in pipe (being constructed right now) */
608 struct command *command;
609 /* last redirect in command->redirects list */
610 struct redir_struct *pending_redirect;
616 smallint ctx_inverted; /* "! cmd | cmd" */
618 smallint ctx_dsemicolon; /* ";;" seen */
620 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
622 /* group we are enclosed in:
623 * example: "if pipe1; pipe2; then pipe3; fi"
624 * when we see "if" or "then", we malloc and copy current context,
625 * and make ->stack point to it. then we parse pipeN.
626 * when closing "then" / fi" / whatever is found,
627 * we move list_head into ->stack->command->group,
628 * copy ->stack into current context, and delete ->stack.
629 * (parsing of { list } and ( list ) doesn't use this method)
631 struct parse_context *stack;
635 /* On program start, environ points to initial environment.
636 * putenv adds new pointers into it, unsetenv removes them.
637 * Neither of these (de)allocates the strings.
638 * setenv allocates new strings in malloc space and does putenv,
639 * and thus setenv is unusable (leaky) for shell's purposes */
640 #define setenv(...) setenv_is_leaky_dont_use()
642 struct variable *next;
643 char *varstr; /* points to "name=" portion */
644 #if ENABLE_HUSH_LOCAL
645 unsigned func_nest_level;
647 int max_len; /* if > 0, name is part of initial env; else name is malloced */
648 smallint flg_export; /* putenv should be done on this var */
649 smallint flg_read_only;
657 #if ENABLE_HUSH_FUNCTIONS
659 struct function *next;
661 struct command *parent_cmd;
664 char *body_as_string;
670 /* set -/+o OPT support. (TODO: make it optional)
671 * bash supports the following opts:
682 * interactive-comments on
700 static const char o_opt_strings[] ALIGN1 =
703 #if ENABLE_HUSH_MODE_X
710 #if ENABLE_HUSH_MODE_X
718 struct FILE_list *next;
724 /* "Globals" within this file */
725 /* Sorted roughly by size (smaller offsets == smaller code) */
727 /* interactive_fd != 0 means we are an interactive shell.
728 * If we are, then saved_tty_pgrp can also be != 0, meaning
729 * that controlling tty is available. With saved_tty_pgrp == 0,
730 * job control still works, but terminal signals
731 * (^C, ^Z, ^Y, ^\) won't work at all, and background
732 * process groups can only be created with "cmd &".
733 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
734 * to give tty to the foreground process group,
735 * and will take it back when the group is stopped (^Z)
738 #if ENABLE_HUSH_INTERACTIVE
739 /* 'interactive_fd' is a fd# open to ctty, if we have one
740 * _AND_ if we decided to act interactively */
744 # define G_interactive_fd (G.interactive_fd)
746 # define G_interactive_fd 0
748 #if ENABLE_FEATURE_EDITING
749 line_input_t *line_input_state;
754 #if ENABLE_HUSH_RANDOM_SUPPORT
760 pid_t saved_tty_pgrp;
761 struct pipe *job_list;
762 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
764 # define G_saved_tty_pgrp 0
766 char o_opt[NUM_OPT_O];
767 #if ENABLE_HUSH_MODE_X
768 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
772 smallint flag_SIGINT;
773 #if ENABLE_HUSH_LOOPS
774 smallint flag_break_continue;
776 #if ENABLE_HUSH_FUNCTIONS
777 /* 0: outside of a function (or sourced file)
778 * -1: inside of a function, ok to use return builtin
779 * 1: return is invoked, skip all till end of func
781 smallint flag_return_in_progress;
782 # define G_flag_return_in_progress (G.flag_return_in_progress)
784 # define G_flag_return_in_progress 0
786 smallint exiting; /* used to prevent EXIT trap recursion */
787 /* These four support $?, $#, and $1 */
788 smalluint last_exitcode;
789 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
790 smalluint global_args_malloced;
791 /* how many non-NULL argv's we have. NB: $# + 1 */
795 char *argv0_for_re_execing;
797 #if ENABLE_HUSH_LOOPS
798 unsigned depth_break_continue;
799 unsigned depth_of_loop;
803 struct variable *top_var;
804 char **expanded_assignments;
805 #if ENABLE_HUSH_FUNCTIONS
806 struct function *top_func;
807 # if ENABLE_HUSH_LOCAL
808 struct variable **shadowed_vars_pp;
809 unsigned func_nest_level;
812 /* Signal and trap handling */
814 unsigned count_SIGCHLD;
815 unsigned handled_SIGCHLD;
816 smallint we_have_children;
818 struct FILE_list *FILE_list;
819 /* Which signals have non-DFL handler (even with no traps set)?
820 * Set at the start to:
821 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
822 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
823 * The rest is cleared right before execv syscalls.
824 * Other than these two times, never modified.
826 unsigned special_sig_mask;
828 unsigned fatal_sig_mask;
829 # define G_fatal_sig_mask G.fatal_sig_mask
831 # define G_fatal_sig_mask 0
833 char **traps; /* char *traps[NSIG] */
834 sigset_t pending_set;
836 unsigned long memleak_value;
840 #if ENABLE_FEATURE_EDITING
841 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
844 #define G (*ptr_to_globals)
845 /* Not #defining name to G.name - this quickly gets unwieldy
846 * (too many defines). Also, I actually prefer to see when a variable
847 * is global, thus "G." prefix is a useful hint */
848 #define INIT_G() do { \
849 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
850 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
851 sigfillset(&G.sa.sa_mask); \
852 G.sa.sa_flags = SA_RESTART; \
856 /* Function prototypes for builtins */
857 static int builtin_cd(char **argv) FAST_FUNC;
858 static int builtin_echo(char **argv) FAST_FUNC;
859 static int builtin_eval(char **argv) FAST_FUNC;
860 static int builtin_exec(char **argv) FAST_FUNC;
861 static int builtin_exit(char **argv) FAST_FUNC;
862 static int builtin_export(char **argv) FAST_FUNC;
864 static int builtin_fg_bg(char **argv) FAST_FUNC;
865 static int builtin_jobs(char **argv) FAST_FUNC;
868 static int builtin_help(char **argv) FAST_FUNC;
870 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
871 static int builtin_history(char **argv) FAST_FUNC;
873 #if ENABLE_HUSH_LOCAL
874 static int builtin_local(char **argv) FAST_FUNC;
877 static int builtin_memleak(char **argv) FAST_FUNC;
880 static int builtin_printf(char **argv) FAST_FUNC;
882 static int builtin_pwd(char **argv) FAST_FUNC;
883 static int builtin_read(char **argv) FAST_FUNC;
884 static int builtin_set(char **argv) FAST_FUNC;
885 static int builtin_shift(char **argv) FAST_FUNC;
886 static int builtin_source(char **argv) FAST_FUNC;
887 static int builtin_test(char **argv) FAST_FUNC;
888 static int builtin_trap(char **argv) FAST_FUNC;
889 static int builtin_type(char **argv) FAST_FUNC;
890 static int builtin_true(char **argv) FAST_FUNC;
891 static int builtin_umask(char **argv) FAST_FUNC;
892 static int builtin_unset(char **argv) FAST_FUNC;
893 static int builtin_wait(char **argv) FAST_FUNC;
894 #if ENABLE_HUSH_LOOPS
895 static int builtin_break(char **argv) FAST_FUNC;
896 static int builtin_continue(char **argv) FAST_FUNC;
898 #if ENABLE_HUSH_FUNCTIONS
899 static int builtin_return(char **argv) FAST_FUNC;
902 /* Table of built-in functions. They can be forked or not, depending on
903 * context: within pipes, they fork. As simple commands, they do not.
904 * When used in non-forking context, they can change global variables
905 * in the parent shell process. If forked, of course they cannot.
906 * For example, 'unset foo | whatever' will parse and run, but foo will
907 * still be set at the end. */
908 struct built_in_command {
910 int (*b_function)(char **argv) FAST_FUNC;
913 # define BLTIN(cmd, func, help) { cmd, func, help }
915 # define BLTIN(cmd, func, help) { cmd, func }
919 static const struct built_in_command bltins1[] = {
920 BLTIN("." , builtin_source , "Run commands in a file"),
921 BLTIN(":" , builtin_true , NULL),
923 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
925 #if ENABLE_HUSH_LOOPS
926 BLTIN("break" , builtin_break , "Exit from a loop"),
928 BLTIN("cd" , builtin_cd , "Change directory"),
929 #if ENABLE_HUSH_LOOPS
930 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
932 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
933 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
934 BLTIN("exit" , builtin_exit , "Exit"),
935 BLTIN("export" , builtin_export , "Set environment variables"),
937 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
940 BLTIN("help" , builtin_help , NULL),
942 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
943 BLTIN("history" , builtin_history , "Show command history"),
946 BLTIN("jobs" , builtin_jobs , "List jobs"),
948 #if ENABLE_HUSH_LOCAL
949 BLTIN("local" , builtin_local , "Set local variables"),
952 BLTIN("memleak" , builtin_memleak , NULL),
954 BLTIN("read" , builtin_read , "Input into variable"),
955 #if ENABLE_HUSH_FUNCTIONS
956 BLTIN("return" , builtin_return , "Return from a function"),
958 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
959 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
960 #if ENABLE_HUSH_BASH_COMPAT
961 BLTIN("source" , builtin_source , "Run commands in a file"),
963 BLTIN("trap" , builtin_trap , "Trap signals"),
964 BLTIN("true" , builtin_true , NULL),
965 BLTIN("type" , builtin_type , "Show command type"),
966 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
967 BLTIN("umask" , builtin_umask , "Set file creation mask"),
968 BLTIN("unset" , builtin_unset , "Unset variables"),
969 BLTIN("wait" , builtin_wait , "Wait for process"),
971 /* For now, echo and test are unconditionally enabled.
972 * Maybe make it configurable? */
973 static const struct built_in_command bltins2[] = {
974 BLTIN("[" , builtin_test , NULL),
975 BLTIN("echo" , builtin_echo , NULL),
977 BLTIN("printf" , builtin_printf , NULL),
979 BLTIN("pwd" , builtin_pwd , NULL),
980 BLTIN("test" , builtin_test , NULL),
987 /* prevent disasters with G.debug_indent < 0 */
988 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
989 # define debug_enter() (G.debug_indent++)
990 # define debug_leave() (G.debug_indent--)
992 # define indent() ((void)0)
993 # define debug_enter() ((void)0)
994 # define debug_leave() ((void)0)
998 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1001 #ifndef debug_printf_parse
1002 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1005 #ifndef debug_printf_exec
1006 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1009 #ifndef debug_printf_env
1010 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1013 #ifndef debug_printf_jobs
1014 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1015 # define DEBUG_JOBS 1
1017 # define DEBUG_JOBS 0
1020 #ifndef debug_printf_expand
1021 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1022 # define DEBUG_EXPAND 1
1024 # define DEBUG_EXPAND 0
1027 #ifndef debug_printf_varexp
1028 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1031 #ifndef debug_printf_glob
1032 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1033 # define DEBUG_GLOB 1
1035 # define DEBUG_GLOB 0
1038 #ifndef debug_printf_list
1039 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1042 #ifndef debug_printf_subst
1043 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1046 #ifndef debug_printf_clean
1047 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1048 # define DEBUG_CLEAN 1
1050 # define DEBUG_CLEAN 0
1054 static void debug_print_strings(const char *prefix, char **vv)
1057 fdprintf(2, "%s:\n", prefix);
1059 fdprintf(2, " '%s'\n", *vv++);
1062 # define debug_print_strings(prefix, vv) ((void)0)
1066 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1069 static void *xxmalloc(int lineno, size_t size)
1071 void *ptr = xmalloc((size + 0xff) & ~0xff);
1072 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1075 static void *xxrealloc(int lineno, void *ptr, size_t size)
1077 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1078 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1081 static char *xxstrdup(int lineno, const char *str)
1083 char *ptr = xstrdup(str);
1084 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1087 static void xxfree(void *ptr)
1089 fdprintf(2, "free %p\n", ptr);
1092 # define xmalloc(s) xxmalloc(__LINE__, s)
1093 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1094 # define xstrdup(s) xxstrdup(__LINE__, s)
1095 # define free(p) xxfree(p)
1099 /* Syntax and runtime errors. They always abort scripts.
1100 * In interactive use they usually discard unparsed and/or unexecuted commands
1101 * and return to the prompt.
1102 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1105 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1106 # define syntax_error(lineno, msg) syntax_error(msg)
1107 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1108 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1109 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1110 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1113 static void die_if_script(unsigned lineno, const char *fmt, ...)
1118 bb_error_msg("hush.c:%u", lineno);
1121 bb_verror_msg(fmt, p, NULL);
1123 if (!G_interactive_fd)
1127 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1130 bb_error_msg("syntax error: %s", msg);
1132 bb_error_msg("syntax error");
1135 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1137 bb_error_msg("syntax error at '%s'", msg);
1140 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1142 bb_error_msg("syntax error: unterminated %s", s);
1145 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1147 char msg[2] = { ch, '\0' };
1148 syntax_error_unterm_str(lineno, msg);
1151 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1156 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1160 # undef die_if_script
1161 # undef syntax_error
1162 # undef syntax_error_at
1163 # undef syntax_error_unterm_ch
1164 # undef syntax_error_unterm_str
1165 # undef syntax_error_unexpected_ch
1167 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1168 # define syntax_error(msg) syntax_error(__LINE__, msg)
1169 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1170 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1171 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1172 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1176 #if ENABLE_HUSH_INTERACTIVE
1177 static void cmdedit_update_prompt(void);
1179 # define cmdedit_update_prompt() ((void)0)
1183 /* Utility functions
1185 /* Replace each \x with x in place, return ptr past NUL. */
1186 static char *unbackslash(char *src)
1188 char *dst = src = strchrnul(src, '\\');
1192 if ((*dst++ = *src++) == '\0')
1198 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1219 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1220 v[count1 + count2] = NULL;
1223 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1227 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1229 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1230 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1233 #define add_strings_to_strings(strings, add, need_to_dup) \
1234 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1237 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1238 static char **add_string_to_strings(char **strings, char *add)
1243 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1246 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1248 char **ptr = add_string_to_strings(strings, add);
1249 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1252 #define add_string_to_strings(strings, add) \
1253 xx_add_string_to_strings(__LINE__, strings, add)
1256 static void free_strings(char **strings)
1271 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1273 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1274 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1276 /* fd was not open? */
1286 /* Manipulating the list of open FILEs */
1287 static FILE *remember_FILE(FILE *fp)
1290 struct FILE_list *n = xmalloc(sizeof(*n));
1291 n->next = G.FILE_list;
1295 close_on_exec_on(n->fd);
1299 static void fclose_and_forget(FILE *fp)
1301 struct FILE_list **pp = &G.FILE_list;
1303 struct FILE_list *cur = *pp;
1304 if (cur->fp == fp) {
1313 static int save_FILEs_on_redirect(int fd)
1315 struct FILE_list *fl = G.FILE_list;
1318 /* We use it only on script files, they are all CLOEXEC */
1319 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1326 static void restore_redirected_FILEs(void)
1328 struct FILE_list *fl = G.FILE_list;
1330 int should_be = fileno(fl->fp);
1331 if (fl->fd != should_be) {
1332 xmove_fd(fl->fd, should_be);
1338 #if ENABLE_FEATURE_SH_STANDALONE
1339 static void close_all_FILE_list(void)
1341 struct FILE_list *fl = G.FILE_list;
1343 /* fclose would also free FILE object.
1344 * It is disastrous if we share memory with a vforked parent.
1345 * I'm not sure we never come here after vfork.
1346 * Therefore just close fd, nothing more.
1348 /*fclose(fl->fp); - unsafe */
1356 /* Helpers for setting new $n and restoring them back
1358 typedef struct save_arg_t {
1362 smallint sv_g_malloced;
1365 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1369 sv->sv_argv0 = argv[0];
1370 sv->sv_g_argv = G.global_argv;
1371 sv->sv_g_argc = G.global_argc;
1372 sv->sv_g_malloced = G.global_args_malloced;
1374 argv[0] = G.global_argv[0]; /* retain $0 */
1375 G.global_argv = argv;
1376 G.global_args_malloced = 0;
1384 static void restore_G_args(save_arg_t *sv, char **argv)
1388 if (G.global_args_malloced) {
1389 /* someone ran "set -- arg1 arg2 ...", undo */
1391 while (*++pp) /* note: does not free $0 */
1393 free(G.global_argv);
1395 argv[0] = sv->sv_argv0;
1396 G.global_argv = sv->sv_g_argv;
1397 G.global_argc = sv->sv_g_argc;
1398 G.global_args_malloced = sv->sv_g_malloced;
1402 /* Basic theory of signal handling in shell
1403 * ========================================
1404 * This does not describe what hush does, rather, it is current understanding
1405 * what it _should_ do. If it doesn't, it's a bug.
1406 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1408 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1409 * is finished or backgrounded. It is the same in interactive and
1410 * non-interactive shells, and is the same regardless of whether
1411 * a user trap handler is installed or a shell special one is in effect.
1412 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1413 * backgrounds (i.e. stops) or kills all members of currently running
1416 * Wait builtin is interruptible by signals for which user trap is set
1417 * or by SIGINT in interactive shell.
1419 * Trap handlers will execute even within trap handlers. (right?)
1421 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1422 * except for handlers set to '' (empty string).
1424 * If job control is off, backgrounded commands ("cmd &")
1425 * have SIGINT, SIGQUIT set to SIG_IGN.
1427 * Commands which are run in command substitution ("`cmd`")
1428 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1430 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1431 * by the shell from its parent.
1433 * Signals which differ from SIG_DFL action
1434 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1437 * SIGTERM (interactive): ignore
1438 * SIGHUP (interactive):
1439 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1440 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1441 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1442 * that all pipe members are stopped. Try this in bash:
1443 * while :; do :; done - ^Z does not background it
1444 * (while :; do :; done) - ^Z backgrounds it
1445 * SIGINT (interactive): wait for last pipe, ignore the rest
1446 * of the command line, show prompt. NB: ^C does not send SIGINT
1447 * to interactive shell while shell is waiting for a pipe,
1448 * since shell is bg'ed (is not in foreground process group).
1449 * Example 1: this waits 5 sec, but does not execute ls:
1450 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1451 * Example 2: this does not wait and does not execute ls:
1452 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1453 * Example 3: this does not wait 5 sec, but executes ls:
1454 * "sleep 5; ls -l" + press ^C
1455 * Example 4: this does not wait and does not execute ls:
1456 * "sleep 5 & wait; ls -l" + press ^C
1458 * (What happens to signals which are IGN on shell start?)
1459 * (What happens with signal mask on shell start?)
1461 * Old implementation
1462 * ==================
1463 * We use in-kernel pending signal mask to determine which signals were sent.
1464 * We block all signals which we don't want to take action immediately,
1465 * i.e. we block all signals which need to have special handling as described
1466 * above, and all signals which have traps set.
1467 * After each pipe execution, we extract any pending signals via sigtimedwait()
1470 * unsigned special_sig_mask: a mask of such "special" signals
1471 * sigset_t blocked_set: current blocked signal set
1474 * clear bit in blocked_set unless it is also in special_sig_mask
1475 * "trap 'cmd' SIGxxx":
1476 * set bit in blocked_set (even if 'cmd' is '')
1477 * after [v]fork, if we plan to be a shell:
1478 * unblock signals with special interactive handling
1479 * (child shell is not interactive),
1480 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1481 * after [v]fork, if we plan to exec:
1482 * POSIX says fork clears pending signal mask in child - no need to clear it.
1483 * Restore blocked signal set to one inherited by shell just prior to exec.
1485 * Note: as a result, we do not use signal handlers much. The only uses
1486 * are to count SIGCHLDs
1487 * and to restore tty pgrp on signal-induced exit.
1490 * Standard says "When a subshell is entered, traps that are not being ignored
1491 * are set to the default actions". bash interprets it so that traps which
1492 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1494 * Problem: the above approach makes it unwieldy to catch signals while
1495 * we are in read builtin, or while we read commands from stdin:
1496 * masked signals are not visible!
1498 * New implementation
1499 * ==================
1500 * We record each signal we are interested in by installing signal handler
1501 * for them - a bit like emulating kernel pending signal mask in userspace.
1502 * We are interested in: signals which need to have special handling
1503 * as described above, and all signals which have traps set.
1504 * Signals are recorded in pending_set.
1505 * After each pipe execution, we extract any pending signals
1508 * unsigned special_sig_mask: a mask of shell-special signals.
1509 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1510 * char *traps[sig] if trap for sig is set (even if it's '').
1511 * sigset_t pending_set: set of sigs we received.
1514 * if sig is in special_sig_mask, set handler back to:
1515 * record_pending_signo, or to IGN if it's a tty stop signal
1516 * if sig is in fatal_sig_mask, set handler back to sigexit.
1517 * else: set handler back to SIG_DFL
1518 * "trap 'cmd' SIGxxx":
1519 * set handler to record_pending_signo.
1521 * set handler to SIG_IGN.
1522 * after [v]fork, if we plan to be a shell:
1523 * set signals with special interactive handling to SIG_DFL
1524 * (because child shell is not interactive),
1525 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1526 * after [v]fork, if we plan to exec:
1527 * POSIX says fork clears pending signal mask in child - no need to clear it.
1529 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1530 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1533 * Standard says "When a subshell is entered, traps that are not being ignored
1534 * are set to the default actions". bash interprets it so that traps which
1535 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1538 SPECIAL_INTERACTIVE_SIGS = 0
1543 SPECIAL_JOBSTOP_SIGS = 0
1552 static void record_pending_signo(int sig)
1554 sigaddset(&G.pending_set, sig);
1555 #if ENABLE_HUSH_FAST
1556 if (sig == SIGCHLD) {
1558 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1563 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1565 struct sigaction old_sa;
1567 /* We could use signal() to install handlers... almost:
1568 * except that we need to mask ALL signals while handlers run.
1569 * I saw signal nesting in strace, race window isn't small.
1570 * SA_RESTART is also needed, but in Linux, signal()
1571 * sets SA_RESTART too.
1573 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1574 /* sigfillset(&G.sa.sa_mask); - already done */
1575 /* G.sa.sa_flags = SA_RESTART; - already done */
1576 G.sa.sa_handler = handler;
1577 sigaction(sig, &G.sa, &old_sa);
1578 return old_sa.sa_handler;
1581 static void hush_exit(int exitcode) NORETURN;
1582 static void fflush_and__exit(void) NORETURN;
1583 static void restore_ttypgrp_and__exit(void) NORETURN;
1585 static void restore_ttypgrp_and__exit(void)
1587 /* xfunc has failed! die die die */
1588 /* no EXIT traps, this is an escape hatch! */
1590 hush_exit(xfunc_error_retval);
1593 /* Needed only on some libc:
1594 * It was observed that on exit(), fgetc'ed buffered data
1595 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1596 * With the net effect that even after fork(), not vfork(),
1597 * exit() in NOEXECed applet in "sh SCRIPT":
1598 * noexec_applet_here
1599 * echo END_OF_SCRIPT
1600 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1601 * This makes "echo END_OF_SCRIPT" executed twice.
1602 * Similar problems can be seen with die_if_script() -> xfunc_die()
1603 * and in `cmd` handling.
1604 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1606 static void fflush_and__exit(void)
1609 _exit(xfunc_error_retval);
1614 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1615 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1616 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1617 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1619 /* Restores tty foreground process group, and exits.
1620 * May be called as signal handler for fatal signal
1621 * (will resend signal to itself, producing correct exit state)
1622 * or called directly with -EXITCODE.
1623 * We also call it if xfunc is exiting.
1625 static void sigexit(int sig) NORETURN;
1626 static void sigexit(int sig)
1628 /* Careful: we can end up here after [v]fork. Do not restore
1629 * tty pgrp then, only top-level shell process does that */
1630 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1631 /* Disable all signals: job control, SIGPIPE, etc.
1632 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1634 sigprocmask_allsigs(SIG_BLOCK);
1635 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1638 /* Not a signal, just exit */
1642 kill_myself_with_sig(sig); /* does not return */
1646 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1647 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1651 static sighandler_t pick_sighandler(unsigned sig)
1653 sighandler_t handler = SIG_DFL;
1654 if (sig < sizeof(unsigned)*8) {
1655 unsigned sigmask = (1 << sig);
1659 if (G_fatal_sig_mask & sigmask)
1663 /* sig has special handling? */
1664 if (G.special_sig_mask & sigmask) {
1665 handler = record_pending_signo;
1666 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1667 * in order to ignore them: they will be raised
1668 * in an endless loop when we try to do some
1669 * terminal ioctls! We do have to _ignore_ these.
1671 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1678 /* Restores tty foreground process group, and exits. */
1679 static void hush_exit(int exitcode)
1681 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1682 save_history(G.line_input_state);
1686 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1688 /* argv[0] is unused */
1689 argv[1] = G.traps[0];
1691 G.exiting = 1; /* prevent EXIT trap recursion */
1692 /* Note: G.traps[0] is not cleared!
1693 * "trap" will still show it, if executed
1698 #if ENABLE_FEATURE_CLEAN_UP
1700 struct variable *cur_var;
1701 if (G.cwd != bb_msg_unknown)
1703 cur_var = G.top_var;
1705 struct variable *tmp = cur_var;
1706 if (!cur_var->max_len)
1707 free(cur_var->varstr);
1708 cur_var = cur_var->next;
1716 sigexit(- (exitcode & 0xff));
1723 //TODO: return a mask of ALL handled sigs?
1724 static int check_and_run_traps(void)
1731 if (sigisemptyset(&G.pending_set))
1736 if (sigismember(&G.pending_set, sig)) {
1737 sigdelset(&G.pending_set, sig);
1740 } while (sig < NSIG);
1743 if (G.traps && G.traps[sig]) {
1744 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1745 if (G.traps[sig][0]) {
1746 /* We have user-defined handler */
1747 smalluint save_rcode;
1749 /* argv[0] is unused */
1750 argv[1] = G.traps[sig];
1752 save_rcode = G.last_exitcode;
1754 G.last_exitcode = save_rcode;
1756 } /* else: "" trap, ignoring signal */
1759 /* not a trap: special action */
1762 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1763 /* Builtin was ^C'ed, make it look prettier: */
1771 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1772 /* bash is observed to signal whole process groups,
1773 * not individual processes */
1774 for (job = G.job_list; job; job = job->next) {
1777 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1778 if (kill(- job->pgrp, SIGHUP) == 0)
1779 kill(- job->pgrp, SIGCONT);
1784 #if ENABLE_HUSH_FAST
1786 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1788 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1790 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1791 * This simplifies wait builtin a bit.
1795 default: /* ignored: */
1796 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1797 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1799 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1800 * Example: wait is not interrupted by TERM
1801 * in interactive shell, because TERM is ignored.
1810 static const char *get_cwd(int force)
1812 if (force || G.cwd == NULL) {
1813 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1814 * we must not try to free(bb_msg_unknown) */
1815 if (G.cwd == bb_msg_unknown)
1817 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1819 G.cwd = bb_msg_unknown;
1826 * Shell and environment variable support
1828 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1830 struct variable **pp;
1831 struct variable *cur;
1834 while ((cur = *pp) != NULL) {
1835 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1842 static const char* FAST_FUNC get_local_var_value(const char *name)
1844 struct variable **vpp;
1845 unsigned len = strlen(name);
1847 if (G.expanded_assignments) {
1848 char **cpp = G.expanded_assignments;
1851 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1852 return cp + len + 1;
1857 vpp = get_ptr_to_local_var(name, len);
1859 return (*vpp)->varstr + len + 1;
1861 if (strcmp(name, "PPID") == 0)
1862 return utoa(G.root_ppid);
1863 // bash compat: UID? EUID?
1864 #if ENABLE_HUSH_RANDOM_SUPPORT
1865 if (strcmp(name, "RANDOM") == 0)
1866 return utoa(next_random(&G.random_gen));
1871 /* str holds "NAME=VAL" and is expected to be malloced.
1872 * We take ownership of it.
1874 * 0: do not change export flag
1875 * (if creating new variable, flag will be 0)
1876 * 1: set export flag and putenv the variable
1877 * -1: clear export flag and unsetenv the variable
1878 * flg_read_only is set only when we handle -R var=val
1880 #if !BB_MMU && ENABLE_HUSH_LOCAL
1881 /* all params are used */
1882 #elif BB_MMU && ENABLE_HUSH_LOCAL
1883 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1884 set_local_var(str, flg_export, local_lvl)
1885 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1886 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1887 set_local_var(str, flg_export)
1888 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1889 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1890 set_local_var(str, flg_export, flg_read_only)
1892 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1894 struct variable **var_pp;
1895 struct variable *cur;
1896 char *free_me = NULL;
1900 eq_sign = strchr(str, '=');
1901 if (!eq_sign) { /* not expected to ever happen? */
1906 name_len = eq_sign - str + 1; /* including '=' */
1907 var_pp = &G.top_var;
1908 while ((cur = *var_pp) != NULL) {
1909 if (strncmp(cur->varstr, str, name_len) != 0) {
1910 var_pp = &cur->next;
1914 /* We found an existing var with this name */
1915 if (cur->flg_read_only) {
1919 bb_error_msg("%s: readonly variable", str);
1923 if (flg_export == -1) { // "&& cur->flg_export" ?
1924 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1929 #if ENABLE_HUSH_LOCAL
1930 if (cur->func_nest_level < local_lvl) {
1931 /* New variable is declared as local,
1932 * and existing one is global, or local
1933 * from enclosing function.
1934 * Remove and save old one: */
1935 *var_pp = cur->next;
1936 cur->next = *G.shadowed_vars_pp;
1937 *G.shadowed_vars_pp = cur;
1938 /* bash 3.2.33(1) and exported vars:
1940 * # f() { local z=a; env | grep ^z; }
1946 if (cur->flg_export)
1951 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1956 if (cur->max_len != 0) {
1957 if (cur->max_len >= strlen(str)) {
1958 /* This one is from startup env, reuse space */
1959 strcpy(cur->varstr, str);
1964 goto set_str_and_exp;
1966 /* max_len == 0 signifies "malloced" var, which we can
1967 * (and have to) free. But we can't free(cur->varstr) here:
1968 * if cur->flg_export is 1, it is in the environment.
1969 * We should either unsetenv+free, or wait until putenv,
1970 * then putenv(new)+free(old).
1972 free_me = cur->varstr;
1973 goto set_str_and_exp;
1976 /* Not found - create new variable struct */
1977 cur = xzalloc(sizeof(*cur));
1978 #if ENABLE_HUSH_LOCAL
1979 cur->func_nest_level = local_lvl;
1981 cur->next = *var_pp;
1987 cur->flg_read_only = flg_read_only;
1990 if (flg_export == 1)
1991 cur->flg_export = 1;
1992 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1993 cmdedit_update_prompt();
1994 if (cur->flg_export) {
1995 if (flg_export == -1) {
1996 cur->flg_export = 0;
1997 /* unsetenv was already done */
2000 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2001 i = putenv(cur->varstr);
2002 /* only now we can free old exported malloced string */
2011 /* Used at startup and after each cd */
2012 static void set_pwd_var(int exp)
2014 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2015 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2018 static int unset_local_var_len(const char *name, int name_len)
2020 struct variable *cur;
2021 struct variable **var_pp;
2024 return EXIT_SUCCESS;
2025 var_pp = &G.top_var;
2026 while ((cur = *var_pp) != NULL) {
2027 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2028 if (cur->flg_read_only) {
2029 bb_error_msg("%s: readonly variable", name);
2030 return EXIT_FAILURE;
2032 *var_pp = cur->next;
2033 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2034 bb_unsetenv(cur->varstr);
2035 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2036 cmdedit_update_prompt();
2040 return EXIT_SUCCESS;
2042 var_pp = &cur->next;
2044 return EXIT_SUCCESS;
2047 static int unset_local_var(const char *name)
2049 return unset_local_var_len(name, strlen(name));
2052 static void unset_vars(char **strings)
2060 const char *eq = strchrnul(*v, '=');
2061 unset_local_var_len(*v, (int)(eq - *v));
2067 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2069 char *var = xasprintf("%s=%s", name, val);
2070 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2075 * Helpers for "var1=val1 var2=val2 cmd" feature
2077 static void add_vars(struct variable *var)
2079 struct variable *next;
2083 var->next = G.top_var;
2085 if (var->flg_export) {
2086 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2087 putenv(var->varstr);
2089 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2095 static struct variable *set_vars_and_save_old(char **strings)
2098 struct variable *old = NULL;
2104 struct variable *var_p;
2105 struct variable **var_pp;
2108 eq = strchr(*s, '=');
2110 var_pp = get_ptr_to_local_var(*s, eq - *s);
2112 /* Remove variable from global linked list */
2114 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2115 *var_pp = var_p->next;
2116 /* Add it to returned list */
2120 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2131 static void reinit_unicode_for_hush(void)
2133 /* Unicode support should be activated even if LANG is set
2134 * _during_ shell execution, not only if it was set when
2135 * shell was started. Therefore, re-check LANG every time:
2137 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2138 || ENABLE_UNICODE_USING_LOCALE
2140 const char *s = get_local_var_value("LC_ALL");
2141 if (!s) s = get_local_var_value("LC_CTYPE");
2142 if (!s) s = get_local_var_value("LANG");
2148 * in_str support (strings, and "strings" read from files).
2151 #if ENABLE_HUSH_INTERACTIVE
2152 /* To test correct lineedit/interactive behavior, type from command line:
2158 * It excercises a lot of corner cases.
2160 static void cmdedit_update_prompt(void)
2162 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2163 G.PS1 = get_local_var_value("PS1");
2166 G.PS2 = get_local_var_value("PS2");
2173 static const char *setup_prompt_string(int promptmode)
2175 const char *prompt_str;
2176 debug_printf("setup_prompt_string %d ", promptmode);
2177 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2178 /* Set up the prompt */
2179 if (promptmode == 0) { /* PS1 */
2181 /* bash uses $PWD value, even if it is set by user.
2182 * It uses current dir only if PWD is unset.
2183 * We always use current dir. */
2184 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2189 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2190 debug_printf("prompt_str '%s'\n", prompt_str);
2193 static int get_user_input(struct in_str *i)
2196 const char *prompt_str;
2198 prompt_str = setup_prompt_string(i->promptmode);
2199 # if ENABLE_FEATURE_EDITING
2201 reinit_unicode_for_hush();
2203 /* buglet: SIGINT will not make new prompt to appear _at once_,
2204 * only after <Enter>. (^C will work) */
2205 r = read_line_input(G.line_input_state, prompt_str,
2206 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2209 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2210 check_and_run_traps();
2211 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2213 /* EOF/error detected */
2215 i->peek_buf[0] = r = EOF;
2218 i->p = G.user_input_buf;
2219 return (unsigned char)*i->p++;
2223 if (i->last_char == '\0' || i->last_char == '\n') {
2224 /* Why check_and_run_traps here? Try this interactively:
2225 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2226 * $ <[enter], repeatedly...>
2227 * Without check_and_run_traps, handler never runs.
2229 check_and_run_traps();
2230 fputs(prompt_str, stdout);
2234 } while (G.flag_SIGINT || r == '\0');
2238 /* This is the magic location that prints prompts
2239 * and gets data back from the user */
2240 static int fgetc_interactive(struct in_str *i)
2243 /* If it's interactive stdin, get new line. */
2244 if (G_interactive_fd && i->file == stdin) {
2245 /* Returns first char (or EOF), the rest is in i->p[] */
2246 ch = get_user_input(i);
2247 i->promptmode = 1; /* PS2 */
2249 /* Not stdin: script file, sourced file, etc */
2250 do ch = fgetc(i->file); while (ch == '\0');
2255 static inline int fgetc_interactive(struct in_str *i)
2258 do ch = fgetc(i->file); while (ch == '\0');
2261 #endif /* INTERACTIVE */
2263 static int FAST_FUNC file_get(struct in_str *i)
2267 #if ENABLE_FEATURE_EDITING
2268 /* This can be stdin, check line editing char[] buffer */
2269 if (i->p && *i->p != '\0') {
2270 ch = (unsigned char)*i->p++;
2274 /* peek_buf[] is an int array, not char. Can contain EOF. */
2275 ch = i->peek_buf[0];
2277 int ch2 = i->peek_buf[1];
2278 i->peek_buf[0] = ch2;
2279 if (ch2 == 0) /* very likely, avoid redundant write */
2285 ch = fgetc_interactive(i);
2287 debug_printf("file_get: got '%c' %d\n", ch, ch);
2292 static int FAST_FUNC file_peek(struct in_str *i)
2296 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2297 /* This can be stdin, check line editing char[] buffer */
2298 if (i->p && *i->p != '\0')
2299 return (unsigned char)*i->p;
2301 /* peek_buf[] is an int array, not char. Can contain EOF. */
2302 ch = i->peek_buf[0];
2306 /* Need to get a new char */
2307 ch = fgetc_interactive(i);
2308 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2310 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2311 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2317 i->peek_buf[0] = ch;
2318 /*i->peek_buf[1] = 0; - already is */
2322 static int FAST_FUNC static_get(struct in_str *i)
2324 int ch = (unsigned char)*i->p;
2333 static int FAST_FUNC static_peek(struct in_str *i)
2335 /* Doesn't report EOF on NUL. None of the callers care. */
2336 return (unsigned char)*i->p;
2339 /* Only ever called if i_peek() was called, and did not return EOF.
2340 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2341 * not end-of-line. Therefore we never need to read a new editing line here.
2343 static int i_peek2(struct in_str *i)
2347 /* There are two cases when i->p[] buffer exists.
2348 * (1) it's a string in_str.
2349 * (2) It's a file, and we have a saved line editing buffer.
2350 * In both cases, we know that i->p[0] exists and not NUL, and
2351 * the peek2 result is in i->p[1].
2354 return (unsigned char)i->p[1];
2356 /* Now we know it is a file-based in_str. */
2358 /* peek_buf[] is an int array, not char. Can contain EOF. */
2359 /* Is there 2nd char? */
2360 ch = i->peek_buf[1];
2362 /* We did not read it yet, get it now */
2363 do ch = fgetc(i->file); while (ch == '\0');
2364 i->peek_buf[1] = ch;
2367 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2371 static void setup_file_in_str(struct in_str *i, FILE *f)
2373 memset(i, 0, sizeof(*i));
2375 i->peek = file_peek;
2376 /* i->promptmode = 0; - PS1 (memset did it) */
2381 static void setup_string_in_str(struct in_str *i, const char *s)
2383 memset(i, 0, sizeof(*i));
2384 i->get = static_get;
2385 i->peek = static_peek;
2386 /* i->promptmode = 0; - PS1 (memset did it) */
2394 #define B_CHUNK (32 * sizeof(char*))
2396 static void o_reset_to_empty_unquoted(o_string *o)
2399 o->has_quoted_part = 0;
2404 static void o_free(o_string *o)
2407 memset(o, 0, sizeof(*o));
2410 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2415 static void o_grow_by(o_string *o, int len)
2417 if (o->length + len > o->maxlen) {
2418 o->maxlen += (2 * len) | (B_CHUNK-1);
2419 o->data = xrealloc(o->data, 1 + o->maxlen);
2423 static void o_addchr(o_string *o, int ch)
2425 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2426 if (o->length < o->maxlen) {
2427 /* likely. avoid o_grow_by() call */
2429 o->data[o->length] = ch;
2431 o->data[o->length] = '\0';
2439 /* Valid only if we know o_string is not empty */
2440 static void o_delchr(o_string *o)
2443 o->data[o->length] = '\0';
2447 static void o_addblock(o_string *o, const char *str, int len)
2450 memcpy(&o->data[o->length], str, len);
2452 o->data[o->length] = '\0';
2455 static void o_addstr(o_string *o, const char *str)
2457 o_addblock(o, str, strlen(str));
2461 static void nommu_addchr(o_string *o, int ch)
2467 # define nommu_addchr(o, str) ((void)0)
2470 static void o_addstr_with_NUL(o_string *o, const char *str)
2472 o_addblock(o, str, strlen(str) + 1);
2476 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2477 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2478 * Apparently, on unquoted $v bash still does globbing
2479 * ("v='*.txt'; echo $v" prints all .txt files),
2480 * but NOT brace expansion! Thus, there should be TWO independent
2481 * quoting mechanisms on $v expansion side: one protects
2482 * $v from brace expansion, and other additionally protects "$v" against globbing.
2483 * We have only second one.
2486 #if ENABLE_HUSH_BRACE_EXPANSION
2487 # define MAYBE_BRACES "{}"
2489 # define MAYBE_BRACES ""
2492 /* My analysis of quoting semantics tells me that state information
2493 * is associated with a destination, not a source.
2495 static void o_addqchr(o_string *o, int ch)
2498 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2503 o->data[o->length] = '\\';
2506 o->data[o->length] = ch;
2508 o->data[o->length] = '\0';
2511 static void o_addQchr(o_string *o, int ch)
2514 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2515 && strchr("*?[\\" MAYBE_BRACES, ch)
2518 o->data[o->length] = '\\';
2522 o->data[o->length] = ch;
2524 o->data[o->length] = '\0';
2527 static void o_addqblock(o_string *o, const char *str, int len)
2532 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2533 if (ordinary_cnt > len) /* paranoia */
2535 o_addblock(o, str, ordinary_cnt);
2536 if (ordinary_cnt == len)
2537 return; /* NUL is already added by o_addblock */
2538 str += ordinary_cnt;
2539 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2543 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2545 o->data[o->length] = '\\';
2549 o->data[o->length] = ch;
2552 o->data[o->length] = '\0';
2555 static void o_addQblock(o_string *o, const char *str, int len)
2557 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2558 o_addblock(o, str, len);
2561 o_addqblock(o, str, len);
2564 static void o_addQstr(o_string *o, const char *str)
2566 o_addQblock(o, str, strlen(str));
2569 /* A special kind of o_string for $VAR and `cmd` expansion.
2570 * It contains char* list[] at the beginning, which is grown in 16 element
2571 * increments. Actual string data starts at the next multiple of 16 * (char*).
2572 * list[i] contains an INDEX (int!) into this string data.
2573 * It means that if list[] needs to grow, data needs to be moved higher up
2574 * but list[i]'s need not be modified.
2575 * NB: remembering how many list[i]'s you have there is crucial.
2576 * o_finalize_list() operation post-processes this structure - calculates
2577 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2579 #if DEBUG_EXPAND || DEBUG_GLOB
2580 static void debug_print_list(const char *prefix, o_string *o, int n)
2582 char **list = (char**)o->data;
2583 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2587 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2588 prefix, list, n, string_start, o->length, o->maxlen,
2589 !!(o->o_expflags & EXP_FLAG_GLOB),
2591 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2594 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2595 o->data + (int)(uintptr_t)list[i] + string_start,
2596 o->data + (int)(uintptr_t)list[i] + string_start);
2600 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2602 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2606 # define debug_print_list(prefix, o, n) ((void)0)
2609 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2610 * in list[n] so that it points past last stored byte so far.
2611 * It returns n+1. */
2612 static int o_save_ptr_helper(o_string *o, int n)
2614 char **list = (char**)o->data;
2618 if (!o->has_empty_slot) {
2619 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2620 string_len = o->length - string_start;
2621 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2622 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2623 /* list[n] points to string_start, make space for 16 more pointers */
2624 o->maxlen += 0x10 * sizeof(list[0]);
2625 o->data = xrealloc(o->data, o->maxlen + 1);
2626 list = (char**)o->data;
2627 memmove(list + n + 0x10, list + n, string_len);
2628 o->length += 0x10 * sizeof(list[0]);
2630 debug_printf_list("list[%d]=%d string_start=%d\n",
2631 n, string_len, string_start);
2634 /* We have empty slot at list[n], reuse without growth */
2635 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2636 string_len = o->length - string_start;
2637 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2638 n, string_len, string_start);
2639 o->has_empty_slot = 0;
2641 o->has_quoted_part = 0;
2642 list[n] = (char*)(uintptr_t)string_len;
2646 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2647 static int o_get_last_ptr(o_string *o, int n)
2649 char **list = (char**)o->data;
2650 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2652 return ((int)(uintptr_t)list[n-1]) + string_start;
2655 #if ENABLE_HUSH_BRACE_EXPANSION
2656 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2657 * first, it processes even {a} (no commas), second,
2658 * I didn't manage to make it return strings when they don't match
2659 * existing files. Need to re-implement it.
2663 static int glob_needed(const char *s)
2672 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2678 /* Return pointer to next closing brace or to comma */
2679 static const char *next_brace_sub(const char *cp)
2683 while (*cp != '\0') {
2690 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2696 return *cp != '\0' ? cp : NULL;
2698 /* Recursive brace globber. Note: may garble pattern[]. */
2699 static int glob_brace(char *pattern, o_string *o, int n)
2701 char *new_pattern_buf;
2708 debug_printf_glob("glob_brace('%s')\n", pattern);
2714 if (*begin == '{') {
2715 /* Find the first sub-pattern and at the same time
2716 * find the rest after the closing brace */
2717 next = next_brace_sub(begin);
2719 /* An illegal expression */
2723 /* "{abc}" with no commas - illegal
2724 * brace expr, disregard and skip it */
2730 if (*begin == '\\' && begin[1] != '\0')
2734 debug_printf_glob("begin:%s\n", begin);
2735 debug_printf_glob("next:%s\n", next);
2737 /* Now find the end of the whole brace expression */
2739 while (*rest != '}') {
2740 rest = next_brace_sub(rest);
2742 /* An illegal expression */
2745 debug_printf_glob("rest:%s\n", rest);
2747 rest_len = strlen(++rest) + 1;
2749 /* We are sure the brace expression is well-formed */
2751 /* Allocate working buffer large enough for our work */
2752 new_pattern_buf = xmalloc(strlen(pattern));
2754 /* We have a brace expression. BEGIN points to the opening {,
2755 * NEXT points past the terminator of the first element, and REST
2756 * points past the final }. We will accumulate result names from
2757 * recursive runs for each brace alternative in the buffer using
2762 /* Construct the new glob expression */
2765 mempcpy(new_pattern_buf,
2766 /* We know the prefix for all sub-patterns */
2767 pattern, begin - pattern),
2771 /* Note: glob_brace() may garble new_pattern_buf[].
2772 * That's why we re-copy prefix every time (1st memcpy above).
2774 n = glob_brace(new_pattern_buf, o, n);
2776 /* We saw the last entry */
2780 next = next_brace_sub(next);
2782 free(new_pattern_buf);
2790 memset(&globdata, 0, sizeof(globdata));
2791 gr = glob(pattern, 0, NULL, &globdata);
2792 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2794 if (gr == GLOB_NOMATCH) {
2795 globfree(&globdata);
2796 /* NB: garbles parameter */
2797 unbackslash(pattern);
2798 o_addstr_with_NUL(o, pattern);
2799 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2800 return o_save_ptr_helper(o, n);
2802 if (gr == GLOB_NOSPACE)
2803 bb_error_msg_and_die(bb_msg_memory_exhausted);
2804 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2805 * but we didn't specify it. Paranoia again. */
2806 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2808 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2809 char **argv = globdata.gl_pathv;
2811 o_addstr_with_NUL(o, *argv);
2812 n = o_save_ptr_helper(o, n);
2818 globfree(&globdata);
2822 /* Performs globbing on last list[],
2823 * saving each result as a new list[].
2825 static int perform_glob(o_string *o, int n)
2827 char *pattern, *copy;
2829 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2831 return o_save_ptr_helper(o, n);
2832 pattern = o->data + o_get_last_ptr(o, n);
2833 debug_printf_glob("glob pattern '%s'\n", pattern);
2834 if (!glob_needed(pattern)) {
2835 /* unbackslash last string in o in place, fix length */
2836 o->length = unbackslash(pattern) - o->data;
2837 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2838 return o_save_ptr_helper(o, n);
2841 copy = xstrdup(pattern);
2842 /* "forget" pattern in o */
2843 o->length = pattern - o->data;
2844 n = glob_brace(copy, o, n);
2847 debug_print_list("perform_glob returning", o, n);
2851 #else /* !HUSH_BRACE_EXPANSION */
2854 static int glob_needed(const char *s)
2863 if (*s == '*' || *s == '[' || *s == '?')
2869 /* Performs globbing on last list[],
2870 * saving each result as a new list[].
2872 static int perform_glob(o_string *o, int n)
2878 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2880 return o_save_ptr_helper(o, n);
2881 pattern = o->data + o_get_last_ptr(o, n);
2882 debug_printf_glob("glob pattern '%s'\n", pattern);
2883 if (!glob_needed(pattern)) {
2885 /* unbackslash last string in o in place, fix length */
2886 o->length = unbackslash(pattern) - o->data;
2887 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2888 return o_save_ptr_helper(o, n);
2891 memset(&globdata, 0, sizeof(globdata));
2892 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2893 * If we glob "*.\*" and don't find anything, we need
2894 * to fall back to using literal "*.*", but GLOB_NOCHECK
2895 * will return "*.\*"!
2897 gr = glob(pattern, 0, NULL, &globdata);
2898 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2900 if (gr == GLOB_NOMATCH) {
2901 globfree(&globdata);
2904 if (gr == GLOB_NOSPACE)
2905 bb_error_msg_and_die(bb_msg_memory_exhausted);
2906 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2907 * but we didn't specify it. Paranoia again. */
2908 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2910 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2911 char **argv = globdata.gl_pathv;
2912 /* "forget" pattern in o */
2913 o->length = pattern - o->data;
2915 o_addstr_with_NUL(o, *argv);
2916 n = o_save_ptr_helper(o, n);
2922 globfree(&globdata);
2924 debug_print_list("perform_glob returning", o, n);
2928 #endif /* !HUSH_BRACE_EXPANSION */
2930 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2931 * Otherwise, just finish current list[] and start new */
2932 static int o_save_ptr(o_string *o, int n)
2934 if (o->o_expflags & EXP_FLAG_GLOB) {
2935 /* If o->has_empty_slot, list[n] was already globbed
2936 * (if it was requested back then when it was filled)
2937 * so don't do that again! */
2938 if (!o->has_empty_slot)
2939 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2941 return o_save_ptr_helper(o, n);
2944 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2945 static char **o_finalize_list(o_string *o, int n)
2950 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2952 debug_print_list("finalized", o, n);
2953 debug_printf_expand("finalized n:%d\n", n);
2954 list = (char**)o->data;
2955 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2959 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2964 static void free_pipe_list(struct pipe *pi);
2966 /* Returns pi->next - next pipe in the list */
2967 static struct pipe *free_pipe(struct pipe *pi)
2972 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2973 for (i = 0; i < pi->num_cmds; i++) {
2974 struct command *command;
2975 struct redir_struct *r, *rnext;
2977 command = &pi->cmds[i];
2978 debug_printf_clean(" command %d:\n", i);
2979 if (command->argv) {
2983 for (a = 0, p = command->argv; *p; a++, p++) {
2984 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2987 free_strings(command->argv);
2988 //command->argv = NULL;
2990 /* not "else if": on syntax error, we may have both! */
2991 if (command->group) {
2992 debug_printf_clean(" begin group (cmd_type:%d)\n",
2994 free_pipe_list(command->group);
2995 debug_printf_clean(" end group\n");
2996 //command->group = NULL;
2998 /* else is crucial here.
2999 * If group != NULL, child_func is meaningless */
3000 #if ENABLE_HUSH_FUNCTIONS
3001 else if (command->child_func) {
3002 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3003 command->child_func->parent_cmd = NULL;
3007 free(command->group_as_string);
3008 //command->group_as_string = NULL;
3010 for (r = command->redirects; r; r = rnext) {
3011 debug_printf_clean(" redirect %d%s",
3012 r->rd_fd, redir_table[r->rd_type].descrip);
3013 /* guard against the case >$FOO, where foo is unset or blank */
3014 if (r->rd_filename) {
3015 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3016 free(r->rd_filename);
3017 //r->rd_filename = NULL;
3019 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3023 //command->redirects = NULL;
3025 free(pi->cmds); /* children are an array, they get freed all at once */
3029 //pi->cmdtext = NULL;
3037 static void free_pipe_list(struct pipe *pi)
3041 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3043 debug_printf_clean("pipe followup code %d\n", pi->followup);
3049 /*** Parsing routines ***/
3051 #ifndef debug_print_tree
3052 static void debug_print_tree(struct pipe *pi, int lvl)
3054 static const char *const PIPE[] = {
3060 static const char *RES[] = {
3061 [RES_NONE ] = "NONE" ,
3064 [RES_THEN ] = "THEN" ,
3065 [RES_ELIF ] = "ELIF" ,
3066 [RES_ELSE ] = "ELSE" ,
3069 # if ENABLE_HUSH_LOOPS
3070 [RES_FOR ] = "FOR" ,
3071 [RES_WHILE] = "WHILE",
3072 [RES_UNTIL] = "UNTIL",
3074 [RES_DONE ] = "DONE" ,
3076 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3079 # if ENABLE_HUSH_CASE
3080 [RES_CASE ] = "CASE" ,
3081 [RES_CASE_IN ] = "CASE_IN" ,
3082 [RES_MATCH] = "MATCH",
3083 [RES_CASE_BODY] = "CASE_BODY",
3084 [RES_ESAC ] = "ESAC" ,
3086 [RES_XXXX ] = "XXXX" ,
3087 [RES_SNTX ] = "SNTX" ,
3089 static const char *const CMDTYPE[] = {
3093 # if ENABLE_HUSH_FUNCTIONS
3102 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3103 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3105 while (prn < pi->num_cmds) {
3106 struct command *command = &pi->cmds[prn];
3107 char **argv = command->argv;
3109 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3111 command->assignment_cnt);
3112 if (command->group) {
3113 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3114 CMDTYPE[command->cmd_type],
3117 , " group_as_string:", command->group_as_string
3122 debug_print_tree(command->group, lvl+1);
3126 if (argv) while (*argv) {
3127 fdprintf(2, " '%s'", *argv);
3137 #endif /* debug_print_tree */
3139 static struct pipe *new_pipe(void)
3142 pi = xzalloc(sizeof(struct pipe));
3143 /*pi->followup = 0; - deliberately invalid value */
3144 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3148 /* Command (member of a pipe) is complete, or we start a new pipe
3149 * if ctx->command is NULL.
3150 * No errors possible here.
3152 static int done_command(struct parse_context *ctx)
3154 /* The command is really already in the pipe structure, so
3155 * advance the pipe counter and make a new, null command. */
3156 struct pipe *pi = ctx->pipe;
3157 struct command *command = ctx->command;
3159 #if 0 /* Instead we emit error message at run time */
3160 if (ctx->pending_redirect) {
3161 /* For example, "cmd >" (no filename to redirect to) */
3162 die_if_script("syntax error: %s", "invalid redirect");
3163 ctx->pending_redirect = NULL;
3168 if (IS_NULL_CMD(command)) {
3169 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3173 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3174 //debug_print_tree(ctx->list_head, 20);
3176 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3179 /* Only real trickiness here is that the uncommitted
3180 * command structure is not counted in pi->num_cmds. */
3181 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3182 ctx->command = command = &pi->cmds[pi->num_cmds];
3184 memset(command, 0, sizeof(*command));
3185 return pi->num_cmds; /* used only for 0/nonzero check */
3188 static void done_pipe(struct parse_context *ctx, pipe_style type)
3192 debug_printf_parse("done_pipe entered, followup %d\n", type);
3193 /* Close previous command */
3194 not_null = done_command(ctx);
3195 ctx->pipe->followup = type;
3197 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3198 ctx->ctx_inverted = 0;
3199 ctx->pipe->res_word = ctx->ctx_res_w;
3202 /* Without this check, even just <enter> on command line generates
3203 * tree of three NOPs (!). Which is harmless but annoying.
3204 * IOW: it is safe to do it unconditionally. */
3207 || ctx->ctx_res_w == RES_FI
3209 #if ENABLE_HUSH_LOOPS
3210 || ctx->ctx_res_w == RES_DONE
3211 || ctx->ctx_res_w == RES_FOR
3212 || ctx->ctx_res_w == RES_IN
3214 #if ENABLE_HUSH_CASE
3215 || ctx->ctx_res_w == RES_ESAC
3219 debug_printf_parse("done_pipe: adding new pipe: "
3220 "not_null:%d ctx->ctx_res_w:%d\n",
3221 not_null, ctx->ctx_res_w);
3223 ctx->pipe->next = new_p;
3225 /* RES_THEN, RES_DO etc are "sticky" -
3226 * they remain set for pipes inside if/while.
3227 * This is used to control execution.
3228 * RES_FOR and RES_IN are NOT sticky (needed to support
3229 * cases where variable or value happens to match a keyword):
3231 #if ENABLE_HUSH_LOOPS
3232 if (ctx->ctx_res_w == RES_FOR
3233 || ctx->ctx_res_w == RES_IN)
3234 ctx->ctx_res_w = RES_NONE;
3236 #if ENABLE_HUSH_CASE
3237 if (ctx->ctx_res_w == RES_MATCH)
3238 ctx->ctx_res_w = RES_CASE_BODY;
3239 if (ctx->ctx_res_w == RES_CASE)
3240 ctx->ctx_res_w = RES_CASE_IN;
3242 ctx->command = NULL; /* trick done_command below */
3243 /* Create the memory for command, roughly:
3244 * ctx->pipe->cmds = new struct command;
3245 * ctx->command = &ctx->pipe->cmds[0];
3248 //debug_print_tree(ctx->list_head, 10);
3250 debug_printf_parse("done_pipe return\n");
3253 static void initialize_context(struct parse_context *ctx)
3255 memset(ctx, 0, sizeof(*ctx));
3256 ctx->pipe = ctx->list_head = new_pipe();
3257 /* Create the memory for command, roughly:
3258 * ctx->pipe->cmds = new struct command;
3259 * ctx->command = &ctx->pipe->cmds[0];
3264 /* If a reserved word is found and processed, parse context is modified
3265 * and 1 is returned.
3268 struct reserved_combo {
3271 unsigned char assignment_flag;
3275 FLAG_END = (1 << RES_NONE ),
3277 FLAG_IF = (1 << RES_IF ),
3278 FLAG_THEN = (1 << RES_THEN ),
3279 FLAG_ELIF = (1 << RES_ELIF ),
3280 FLAG_ELSE = (1 << RES_ELSE ),
3281 FLAG_FI = (1 << RES_FI ),
3283 # if ENABLE_HUSH_LOOPS
3284 FLAG_FOR = (1 << RES_FOR ),
3285 FLAG_WHILE = (1 << RES_WHILE),
3286 FLAG_UNTIL = (1 << RES_UNTIL),
3287 FLAG_DO = (1 << RES_DO ),
3288 FLAG_DONE = (1 << RES_DONE ),
3289 FLAG_IN = (1 << RES_IN ),
3291 # if ENABLE_HUSH_CASE
3292 FLAG_MATCH = (1 << RES_MATCH),
3293 FLAG_ESAC = (1 << RES_ESAC ),
3295 FLAG_START = (1 << RES_XXXX ),
3298 static const struct reserved_combo* match_reserved_word(o_string *word)
3300 /* Mostly a list of accepted follow-up reserved words.
3301 * FLAG_END means we are done with the sequence, and are ready
3302 * to turn the compound list into a command.
3303 * FLAG_START means the word must start a new compound list.
3305 static const struct reserved_combo reserved_list[] = {
3307 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3308 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3309 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3310 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3311 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3312 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3314 # if ENABLE_HUSH_LOOPS
3315 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3316 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3317 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3318 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3319 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3320 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3322 # if ENABLE_HUSH_CASE
3323 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3324 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3327 const struct reserved_combo *r;
3329 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3330 if (strcmp(word->data, r->literal) == 0)
3335 /* Return 0: not a keyword, 1: keyword
3337 static int reserved_word(o_string *word, struct parse_context *ctx)
3339 # if ENABLE_HUSH_CASE
3340 static const struct reserved_combo reserved_match = {
3341 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3344 const struct reserved_combo *r;
3346 if (word->has_quoted_part)
3348 r = match_reserved_word(word);
3352 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3353 # if ENABLE_HUSH_CASE
3354 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3355 /* "case word IN ..." - IN part starts first MATCH part */
3356 r = &reserved_match;
3359 if (r->flag == 0) { /* '!' */
3360 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3361 syntax_error("! ! command");
3362 ctx->ctx_res_w = RES_SNTX;
3364 ctx->ctx_inverted = 1;
3367 if (r->flag & FLAG_START) {
3368 struct parse_context *old;
3370 old = xmalloc(sizeof(*old));
3371 debug_printf_parse("push stack %p\n", old);
3372 *old = *ctx; /* physical copy */
3373 initialize_context(ctx);
3375 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3376 syntax_error_at(word->data);
3377 ctx->ctx_res_w = RES_SNTX;
3380 /* "{...} fi" is ok. "{...} if" is not
3382 * if { echo foo; } then { echo bar; } fi */
3383 if (ctx->command->group)
3384 done_pipe(ctx, PIPE_SEQ);
3387 ctx->ctx_res_w = r->res;
3388 ctx->old_flag = r->flag;
3389 word->o_assignment = r->assignment_flag;
3390 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3392 if (ctx->old_flag & FLAG_END) {
3393 struct parse_context *old;
3395 done_pipe(ctx, PIPE_SEQ);
3396 debug_printf_parse("pop stack %p\n", ctx->stack);
3398 old->command->group = ctx->list_head;
3399 old->command->cmd_type = CMD_NORMAL;
3401 /* At this point, the compound command's string is in
3402 * ctx->as_string... except for the leading keyword!
3403 * Consider this example: "echo a | if true; then echo a; fi"
3404 * ctx->as_string will contain "true; then echo a; fi",
3405 * with "if " remaining in old->as_string!
3409 int len = old->as_string.length;
3410 /* Concatenate halves */
3411 o_addstr(&old->as_string, ctx->as_string.data);
3412 o_free_unsafe(&ctx->as_string);
3413 /* Find where leading keyword starts in first half */
3414 str = old->as_string.data + len;
3415 if (str > old->as_string.data)
3416 str--; /* skip whitespace after keyword */
3417 while (str > old->as_string.data && isalpha(str[-1]))
3419 /* Ugh, we're done with this horrid hack */
3420 old->command->group_as_string = xstrdup(str);
3421 debug_printf_parse("pop, remembering as:'%s'\n",
3422 old->command->group_as_string);
3425 *ctx = *old; /* physical copy */
3430 #endif /* HAS_KEYWORDS */
3432 /* Word is complete, look at it and update parsing context.
3433 * Normal return is 0. Syntax errors return 1.
3434 * Note: on return, word is reset, but not o_free'd!
3436 static int done_word(o_string *word, struct parse_context *ctx)
3438 struct command *command = ctx->command;
3440 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3441 if (word->length == 0 && !word->has_quoted_part) {
3442 debug_printf_parse("done_word return 0: true null, ignored\n");
3446 if (ctx->pending_redirect) {
3447 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3448 * only if run as "bash", not "sh" */
3449 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3451 * ...the word that follows the redirection operator
3452 * shall be subjected to tilde expansion, parameter expansion,
3453 * command substitution, arithmetic expansion, and quote
3454 * removal. Pathname expansion shall not be performed
3455 * on the word by a non-interactive shell; an interactive
3456 * shell may perform it, but shall do so only when
3457 * the expansion would result in one word."
3459 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3460 /* Cater for >\file case:
3461 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3462 * Same with heredocs:
3463 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3465 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3466 unbackslash(ctx->pending_redirect->rd_filename);
3467 /* Is it <<"HEREDOC"? */
3468 if (word->has_quoted_part) {
3469 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3472 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3473 ctx->pending_redirect = NULL;
3476 # if ENABLE_HUSH_CASE
3477 if (ctx->ctx_dsemicolon
3478 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3480 /* already done when ctx_dsemicolon was set to 1: */
3481 /* ctx->ctx_res_w = RES_MATCH; */
3482 ctx->ctx_dsemicolon = 0;
3485 if (!command->argv /* if it's the first word... */
3486 # if ENABLE_HUSH_LOOPS
3487 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3488 && ctx->ctx_res_w != RES_IN
3490 # if ENABLE_HUSH_CASE
3491 && ctx->ctx_res_w != RES_CASE
3494 int reserved = reserved_word(word, ctx);
3495 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3497 o_reset_to_empty_unquoted(word);
3498 debug_printf_parse("done_word return %d\n",
3499 (ctx->ctx_res_w == RES_SNTX));
3500 return (ctx->ctx_res_w == RES_SNTX);
3502 # if ENABLE_HUSH_BASH_COMPAT
3503 if (strcmp(word->data, "[[") == 0) {
3504 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3510 if (command->group) {
3511 /* "{ echo foo; } echo bar" - bad */
3512 syntax_error_at(word->data);
3513 debug_printf_parse("done_word return 1: syntax error, "
3514 "groups and arglists don't mix\n");
3518 /* If this word wasn't an assignment, next ones definitely
3519 * can't be assignments. Even if they look like ones. */
3520 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3521 && word->o_assignment != WORD_IS_KEYWORD
3523 word->o_assignment = NOT_ASSIGNMENT;
3525 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3526 command->assignment_cnt++;
3527 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3529 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3530 word->o_assignment = MAYBE_ASSIGNMENT;
3532 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3534 if (word->has_quoted_part
3535 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3536 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3537 /* (otherwise it's known to be not empty and is already safe) */
3539 /* exclude "$@" - it can expand to no word despite "" */
3540 char *p = word->data;
3541 while (p[0] == SPECIAL_VAR_SYMBOL
3542 && (p[1] & 0x7f) == '@'
3543 && p[2] == SPECIAL_VAR_SYMBOL
3548 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3549 debug_print_strings("word appended to argv", command->argv);
3552 #if ENABLE_HUSH_LOOPS
3553 if (ctx->ctx_res_w == RES_FOR) {
3554 if (word->has_quoted_part
3555 || !is_well_formed_var_name(command->argv[0], '\0')
3557 /* bash says just "not a valid identifier" */
3558 syntax_error("not a valid identifier in for");
3561 /* Force FOR to have just one word (variable name) */
3562 /* NB: basically, this makes hush see "for v in ..."
3563 * syntax as if it is "for v; in ...". FOR and IN become
3564 * two pipe structs in parse tree. */
3565 done_pipe(ctx, PIPE_SEQ);
3568 #if ENABLE_HUSH_CASE
3569 /* Force CASE to have just one word */
3570 if (ctx->ctx_res_w == RES_CASE) {
3571 done_pipe(ctx, PIPE_SEQ);
3575 o_reset_to_empty_unquoted(word);
3577 debug_printf_parse("done_word return 0\n");
3582 /* Peek ahead in the input to find out if we have a "&n" construct,
3583 * as in "2>&1", that represents duplicating a file descriptor.
3585 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3586 * REDIRFD_SYNTAX_ERR if syntax error,
3587 * REDIRFD_TO_FILE if no & was seen,
3588 * or the number found.
3591 #define parse_redir_right_fd(as_string, input) \
3592 parse_redir_right_fd(input)
3594 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3600 return REDIRFD_TO_FILE;
3602 ch = i_getch(input); /* get the & */
3603 nommu_addchr(as_string, ch);
3606 ch = i_getch(input);
3607 nommu_addchr(as_string, ch);
3608 return REDIRFD_CLOSE;
3612 while (ch != EOF && isdigit(ch)) {
3613 d = d*10 + (ch-'0');
3615 ch = i_getch(input);
3616 nommu_addchr(as_string, ch);
3621 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3623 bb_error_msg("ambiguous redirect");
3624 return REDIRFD_SYNTAX_ERR;
3627 /* Return code is 0 normal, 1 if a syntax error is detected
3629 static int parse_redirect(struct parse_context *ctx,
3632 struct in_str *input)
3634 struct command *command = ctx->command;
3635 struct redir_struct *redir;
3636 struct redir_struct **redirp;
3639 dup_num = REDIRFD_TO_FILE;
3640 if (style != REDIRECT_HEREDOC) {
3641 /* Check for a '>&1' type redirect */
3642 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3643 if (dup_num == REDIRFD_SYNTAX_ERR)
3646 int ch = i_peek(input);
3647 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3648 if (dup_num) { /* <<-... */
3649 ch = i_getch(input);
3650 nommu_addchr(&ctx->as_string, ch);
3655 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3656 int ch = i_peek(input);
3658 /* >|FILE redirect ("clobbering" >).
3659 * Since we do not support "set -o noclobber" yet,
3660 * >| and > are the same for now. Just eat |.
3662 ch = i_getch(input);
3663 nommu_addchr(&ctx->as_string, ch);
3667 /* Create a new redir_struct and append it to the linked list */
3668 redirp = &command->redirects;
3669 while ((redir = *redirp) != NULL) {
3670 redirp = &(redir->next);
3672 *redirp = redir = xzalloc(sizeof(*redir));
3673 /* redir->next = NULL; */
3674 /* redir->rd_filename = NULL; */
3675 redir->rd_type = style;
3676 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3678 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3679 redir_table[style].descrip);
3681 redir->rd_dup = dup_num;
3682 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3683 /* Erik had a check here that the file descriptor in question
3684 * is legit; I postpone that to "run time"
3685 * A "-" representation of "close me" shows up as a -3 here */
3686 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3687 redir->rd_fd, redir->rd_dup);
3689 #if 0 /* Instead we emit error message at run time */
3690 if (ctx->pending_redirect) {
3691 /* For example, "cmd > <file" */
3692 die_if_script("syntax error: %s", "invalid redirect");
3695 /* Set ctx->pending_redirect, so we know what to do at the
3696 * end of the next parsed word. */
3697 ctx->pending_redirect = redir;
3702 /* If a redirect is immediately preceded by a number, that number is
3703 * supposed to tell which file descriptor to redirect. This routine
3704 * looks for such preceding numbers. In an ideal world this routine
3705 * needs to handle all the following classes of redirects...
3706 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3707 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3708 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3709 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3711 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3713 * ... If n is quoted, the number shall not be recognized as part of
3714 * the redirection expression. For example:
3716 * writes the character 2 into file a"
3717 * We are getting it right by setting ->has_quoted_part on any \<char>
3719 * A -1 return means no valid number was found,
3720 * the caller should use the appropriate default for this redirection.
3722 static int redirect_opt_num(o_string *o)
3726 if (o->data == NULL)
3728 num = bb_strtou(o->data, NULL, 10);
3729 if (errno || num < 0)
3731 o_reset_to_empty_unquoted(o);
3736 #define fetch_till_str(as_string, input, word, skip_tabs) \
3737 fetch_till_str(input, word, skip_tabs)
3739 static char *fetch_till_str(o_string *as_string,
3740 struct in_str *input,
3744 o_string heredoc = NULL_O_STRING;
3746 int prev = 0; /* not \ */
3752 ch = i_getch(input);
3754 nommu_addchr(as_string, ch);
3755 if ((ch == '\n' || ch == EOF)
3756 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3758 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3759 heredoc.data[past_EOL] = '\0';
3760 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3761 return heredoc.data;
3763 while (ch == '\n') {
3764 o_addchr(&heredoc, ch);
3767 past_EOL = heredoc.length;
3769 ch = i_getch(input);
3771 nommu_addchr(as_string, ch);
3772 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3776 o_free_unsafe(&heredoc);
3779 o_addchr(&heredoc, ch);
3780 nommu_addchr(as_string, ch);
3781 if (prev == '\\' && ch == '\\')
3782 /* Correctly handle foo\\<eol> (not a line cont.) */
3783 prev = 0; /* not \ */
3789 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3790 * and load them all. There should be exactly heredoc_cnt of them.
3792 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3794 struct pipe *pi = ctx->list_head;
3796 while (pi && heredoc_cnt) {
3798 struct command *cmd = pi->cmds;
3800 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3802 cmd->argv ? cmd->argv[0] : "NONE");
3803 for (i = 0; i < pi->num_cmds; i++) {
3804 struct redir_struct *redir = cmd->redirects;
3806 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3807 i, cmd->argv ? cmd->argv[0] : "NONE");
3809 if (redir->rd_type == REDIRECT_HEREDOC) {
3812 redir->rd_type = REDIRECT_HEREDOC2;
3813 /* redir->rd_dup is (ab)used to indicate <<- */
3814 p = fetch_till_str(&ctx->as_string, input,
3815 redir->rd_filename, redir->rd_dup);
3817 syntax_error("unexpected EOF in here document");
3820 free(redir->rd_filename);
3821 redir->rd_filename = p;
3824 redir = redir->next;
3831 /* Should be 0. If it isn't, it's a parse error */
3833 bb_error_msg_and_die("heredoc BUG 2");
3839 static int run_list(struct pipe *pi);
3841 #define parse_stream(pstring, input, end_trigger) \
3842 parse_stream(input, end_trigger)
3844 static struct pipe *parse_stream(char **pstring,
3845 struct in_str *input,
3849 #if !ENABLE_HUSH_FUNCTIONS
3850 #define parse_group(dest, ctx, input, ch) \
3851 parse_group(ctx, input, ch)
3853 static int parse_group(o_string *dest, struct parse_context *ctx,
3854 struct in_str *input, int ch)
3856 /* dest contains characters seen prior to ( or {.
3857 * Typically it's empty, but for function defs,
3858 * it contains function name (without '()'). */
3859 struct pipe *pipe_list;
3861 struct command *command = ctx->command;
3863 debug_printf_parse("parse_group entered\n");
3864 #if ENABLE_HUSH_FUNCTIONS
3865 if (ch == '(' && !dest->has_quoted_part) {
3867 if (done_word(dest, ctx))
3870 goto skip; /* (... */
3871 if (command->argv[1]) { /* word word ... (... */
3872 syntax_error_unexpected_ch('(');
3875 /* it is "word(..." or "word (..." */
3877 ch = i_getch(input);
3878 while (ch == ' ' || ch == '\t');
3880 syntax_error_unexpected_ch(ch);
3883 nommu_addchr(&ctx->as_string, ch);
3885 ch = i_getch(input);
3886 while (ch == ' ' || ch == '\t' || ch == '\n');
3888 syntax_error_unexpected_ch(ch);
3891 nommu_addchr(&ctx->as_string, ch);
3892 command->cmd_type = CMD_FUNCDEF;
3897 #if 0 /* Prevented by caller */
3898 if (command->argv /* word [word]{... */
3899 || dest->length /* word{... */
3900 || dest->has_quoted_part /* ""{... */
3903 debug_printf_parse("parse_group return 1: "
3904 "syntax error, groups and arglists don't mix\n");
3909 #if ENABLE_HUSH_FUNCTIONS
3915 command->cmd_type = CMD_SUBSHELL;
3917 /* bash does not allow "{echo...", requires whitespace */
3918 ch = i_getch(input);
3919 if (ch != ' ' && ch != '\t' && ch != '\n') {
3920 syntax_error_unexpected_ch(ch);
3923 nommu_addchr(&ctx->as_string, ch);
3928 # define as_string NULL
3930 char *as_string = NULL;
3932 pipe_list = parse_stream(&as_string, input, endch);
3935 o_addstr(&ctx->as_string, as_string);
3937 /* empty ()/{} or parse error? */
3938 if (!pipe_list || pipe_list == ERR_PTR) {
3939 /* parse_stream already emitted error msg */
3942 debug_printf_parse("parse_group return 1: "
3943 "parse_stream returned %p\n", pipe_list);
3946 command->group = pipe_list;
3948 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3949 command->group_as_string = as_string;
3950 debug_printf_parse("end of group, remembering as:'%s'\n",
3951 command->group_as_string);
3955 debug_printf_parse("parse_group return 0\n");
3957 /* command remains "open", available for possible redirects */
3960 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
3965 ch = i_getch(input);
3968 ch2 = i_peek(input);
3971 /* backslash+newline, skip it */
3976 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
3984 ch2 = i_peek2(input);
3987 /* backslash+newline, skip it */
3993 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3994 /* Subroutines for copying $(...) and `...` things */
3995 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3997 static int add_till_single_quote(o_string *dest, struct in_str *input)
4000 int ch = i_getch(input);
4002 syntax_error_unterm_ch('\'');
4010 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4011 static int add_till_double_quote(o_string *dest, struct in_str *input)
4014 int ch = i_getch(input);
4016 syntax_error_unterm_ch('"');
4021 if (ch == '\\') { /* \x. Copy both chars. */
4023 ch = i_getch(input);
4027 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4032 //if (ch == '$') ...
4035 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4037 * "Within the backquoted style of command substitution, backslash
4038 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4039 * The search for the matching backquote shall be satisfied by the first
4040 * backquote found without a preceding backslash; during this search,
4041 * if a non-escaped backquote is encountered within a shell comment,
4042 * a here-document, an embedded command substitution of the $(command)
4043 * form, or a quoted string, undefined results occur. A single-quoted
4044 * or double-quoted string that begins, but does not end, within the
4045 * "`...`" sequence produces undefined results."
4047 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4049 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4052 int ch = i_getch(input);
4056 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4057 ch = i_getch(input);
4061 && (!in_dquote || ch != '"')
4063 o_addchr(dest, '\\');
4067 syntax_error_unterm_ch('`');
4073 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4074 * quoting and nested ()s.
4075 * "With the $(command) style of command substitution, all characters
4076 * following the open parenthesis to the matching closing parenthesis
4077 * constitute the command. Any valid shell script can be used for command,
4078 * except a script consisting solely of redirections which produces
4079 * unspecified results."
4081 * echo $(echo '(TEST)' BEST) (TEST) BEST
4082 * echo $(echo 'TEST)' BEST) TEST) BEST
4083 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4085 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4086 * can contain arbitrary constructs, just like $(cmd).
4087 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4088 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4090 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4091 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4094 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4095 # if ENABLE_HUSH_BASH_COMPAT
4096 char end_char2 = end_ch >> 8;
4098 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4101 ch = i_getch(input);
4103 syntax_error_unterm_ch(end_ch);
4106 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4109 /* we look for closing )) of $((EXPR)) */
4110 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4111 i_getch(input); /* eat second ')' */
4116 if (ch == '(' || ch == '{') {
4117 ch = (ch == '(' ? ')' : '}');
4118 if (!add_till_closing_bracket(dest, input, ch))
4124 if (!add_till_single_quote(dest, input))
4130 if (!add_till_double_quote(dest, input))
4136 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4142 /* \x. Copy verbatim. Important for \(, \) */
4143 ch = i_getch(input);
4145 syntax_error_unterm_ch(')');
4150 /* "backslash+newline", ignore both */
4151 o_delchr(dest); /* undo insertion of '\' */
4161 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
4163 /* Return code: 0 for OK, 1 for syntax error */
4165 #define parse_dollar(as_string, dest, input, quote_mask) \
4166 parse_dollar(dest, input, quote_mask)
4167 #define as_string NULL
4169 static int parse_dollar(o_string *as_string,
4171 struct in_str *input, unsigned char quote_mask)
4173 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4175 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4177 ch = i_getch(input);
4178 nommu_addchr(as_string, ch);
4180 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4182 debug_printf_parse(": '%c'\n", ch);
4183 o_addchr(dest, ch | quote_mask);
4185 ch = i_peek_and_eat_bkslash_nl(input);
4186 if (!isalnum(ch) && ch != '_') {
4187 /* End of variable name reached */
4190 ch = i_getch(input);
4191 nommu_addchr(as_string, ch);
4193 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4194 } else if (isdigit(ch)) {
4196 ch = i_getch(input);
4197 nommu_addchr(as_string, ch);
4198 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4199 debug_printf_parse(": '%c'\n", ch);
4200 o_addchr(dest, ch | quote_mask);
4201 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4202 } else switch (ch) {
4204 case '!': /* last bg pid */
4205 case '?': /* last exit code */
4206 case '#': /* number of args */
4207 case '*': /* args */
4208 case '@': /* args */
4209 goto make_one_char_var;
4211 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4213 ch = i_getch(input); /* eat '{' */
4214 nommu_addchr(as_string, ch);
4216 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4217 /* It should be ${?}, or ${#var},
4218 * or even ${?+subst} - operator acting on a special variable,
4219 * or the beginning of variable name.
4222 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4225 syntax_error_unterm_str("${name}");
4226 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4229 nommu_addchr(as_string, ch);
4232 /* It's possible to just call add_till_closing_bracket() at this point.
4233 * However, this regresses some of our testsuite cases
4234 * which check invalid constructs like ${%}.
4235 * Oh well... let's check that the var name part is fine... */
4241 debug_printf_parse(": '%c'\n", ch);
4243 ch = i_getch(input);
4244 nommu_addchr(as_string, ch);
4248 if (!isalnum(ch) && ch != '_') {
4250 unsigned char last_ch;
4251 /* handle parameter expansions
4252 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4254 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4255 goto bad_dollar_syntax;
4257 /* Eat everything until closing '}' (or ':') */
4259 if (ENABLE_HUSH_BASH_COMPAT
4261 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4263 /* It's ${var:N[:M]} thing */
4264 end_ch = '}' * 0x100 + ':';
4266 if (ENABLE_HUSH_BASH_COMPAT
4269 /* It's ${var/[/]pattern[/repl]} thing */
4270 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4272 nommu_addchr(as_string, '/');
4275 end_ch = '}' * 0x100 + '/';
4281 #if ENABLE_HUSH_DOLLAR_OPS
4282 last_ch = add_till_closing_bracket(dest, input, end_ch);
4283 if (last_ch == 0) /* error? */
4286 #error Simple code to only allow ${var} is not implemented
4289 o_addstr(as_string, dest->data + pos);
4290 o_addchr(as_string, last_ch);
4293 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4294 /* close the first block: */
4295 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4296 /* while parsing N from ${var:N[:M]}
4297 * or pattern from ${var/[/]pattern[/repl]} */
4298 if ((end_ch & 0xff) == last_ch) {
4299 /* got ':' or '/'- parse the rest */
4304 if (end_ch == '}' * 0x100 + ':') {
4305 /* it's ${var:N} - emulate :999999999 */
4306 o_addstr(dest, "999999999");
4307 } /* else: it's ${var/[/]pattern} */
4312 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4315 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4319 ch = i_getch(input);
4320 nommu_addchr(as_string, ch);
4321 # if ENABLE_SH_MATH_SUPPORT
4322 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4323 ch = i_getch(input);
4324 nommu_addchr(as_string, ch);
4325 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4326 o_addchr(dest, /*quote_mask |*/ '+');
4329 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4330 return 0; /* error */
4332 o_addstr(as_string, dest->data + pos);
4333 o_addchr(as_string, ')');
4334 o_addchr(as_string, ')');
4336 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4340 # if ENABLE_HUSH_TICK
4341 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4342 o_addchr(dest, quote_mask | '`');
4345 if (!add_till_closing_bracket(dest, input, ')'))
4346 return 0; /* error */
4348 o_addstr(as_string, dest->data + pos);
4349 o_addchr(as_string, ')');
4351 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4357 ch = i_getch(input);
4358 nommu_addchr(as_string, ch);
4359 ch = i_peek_and_eat_bkslash_nl(input);
4360 if (isalnum(ch)) { /* it's $_name or $_123 */
4365 /* TODO: $_ and $-: */
4366 /* $_ Shell or shell script name; or last argument of last command
4367 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4368 * but in command's env, set to full pathname used to invoke it */
4369 /* $- Option flags set by set builtin or shell options (-i etc) */
4371 o_addQchr(dest, '$');
4373 debug_printf_parse("parse_dollar return 1 (ok)\n");
4379 # if ENABLE_HUSH_BASH_COMPAT
4380 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4381 encode_string(dest, input, dquote_end, process_bkslash)
4383 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4384 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4385 encode_string(dest, input, dquote_end)
4387 #define as_string NULL
4391 # if ENABLE_HUSH_BASH_COMPAT
4392 /* all parameters are needed, no macro tricks */
4394 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4395 encode_string(as_string, dest, input, dquote_end)
4398 static int encode_string(o_string *as_string,
4400 struct in_str *input,
4402 int process_bkslash)
4404 #if !ENABLE_HUSH_BASH_COMPAT
4405 const int process_bkslash = 1;
4411 ch = i_getch(input);
4413 nommu_addchr(as_string, ch);
4414 if (ch == dquote_end) { /* may be only '"' or EOF */
4415 debug_printf_parse("encode_string return 1 (ok)\n");
4418 /* note: can't move it above ch == dquote_end check! */
4420 syntax_error_unterm_ch('"');
4421 return 0; /* error */
4425 next = i_peek(input);
4427 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4428 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4429 if (process_bkslash && ch == '\\') {
4431 syntax_error("\\<eof>");
4435 * "The backslash retains its special meaning [in "..."]
4436 * only when followed by one of the following characters:
4437 * $, `, ", \, or <newline>. A double quote may be quoted
4438 * within double quotes by preceding it with a backslash."
4439 * NB: in (unquoted) heredoc, above does not apply to ",
4440 * therefore we check for it by "next == dquote_end" cond.
4442 if (next == dquote_end || strchr("$`\\\n", next)) {
4443 ch = i_getch(input); /* eat next */
4445 goto again; /* skip \<newline> */
4446 } /* else: ch remains == '\\', and we double it below: */
4447 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4448 nommu_addchr(as_string, ch);
4452 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4453 debug_printf_parse("encode_string return 0: "
4454 "parse_dollar returned 0 (error)\n");
4459 #if ENABLE_HUSH_TICK
4461 //unsigned pos = dest->length;
4462 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4463 o_addchr(dest, 0x80 | '`');
4464 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4465 return 0; /* error */
4466 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4467 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4471 o_addQchr(dest, ch);
4477 * Scan input until EOF or end_trigger char.
4478 * Return a list of pipes to execute, or NULL on EOF
4479 * or if end_trigger character is met.
4480 * On syntax error, exit if shell is not interactive,
4481 * reset parsing machinery and start parsing anew,
4482 * or return ERR_PTR.
4484 static struct pipe *parse_stream(char **pstring,
4485 struct in_str *input,
4488 struct parse_context ctx;
4489 o_string dest = NULL_O_STRING;
4492 /* Single-quote triggers a bypass of the main loop until its mate is
4493 * found. When recursing, quote state is passed in via dest->o_expflags.
4495 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4496 end_trigger ? end_trigger : 'X');
4499 /* If very first arg is "" or '', dest.data may end up NULL.
4500 * Preventing this: */
4501 o_addchr(&dest, '\0');
4504 /* We used to separate words on $IFS here. This was wrong.
4505 * $IFS is used only for word splitting when $var is expanded,
4506 * here we should use blank chars as separators, not $IFS
4509 if (MAYBE_ASSIGNMENT != 0)
4510 dest.o_assignment = MAYBE_ASSIGNMENT;
4511 initialize_context(&ctx);
4514 const char *is_blank;
4515 const char *is_special;
4519 redir_type redir_style;
4521 ch = i_getch(input);
4522 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4523 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4528 syntax_error_unterm_str("here document");
4531 /* end_trigger == '}' case errors out earlier,
4532 * checking only ')' */
4533 if (end_trigger == ')') {
4534 syntax_error_unterm_ch('(');
4538 if (done_word(&dest, &ctx)) {
4542 done_pipe(&ctx, PIPE_SEQ);
4544 /* If we got nothing... */
4545 /* (this makes bare "&" cmd a no-op.
4546 * bash says: "syntax error near unexpected token '&'") */
4547 if (pi->num_cmds == 0
4548 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4554 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4556 *pstring = ctx.as_string.data;
4558 o_free_unsafe(&ctx.as_string);
4561 debug_printf_parse("parse_stream return %p\n", pi);
4564 nommu_addchr(&ctx.as_string, ch);
4568 next = i_peek(input);
4570 is_special = "{}<>;&|()#'" /* special outside of "str" */
4571 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4572 /* Are { and } special here? */
4573 if (ctx.command->argv /* word [word]{... - non-special */
4574 || dest.length /* word{... - non-special */
4575 || dest.has_quoted_part /* ""{... - non-special */
4576 || (next != ';' /* }; - special */
4577 && next != ')' /* }) - special */
4578 && next != '&' /* }& and }&& ... - special */
4579 && next != '|' /* }|| ... - special */
4580 && !strchr(defifs, next) /* {word - non-special */
4583 /* They are not special, skip "{}" */
4586 is_special = strchr(is_special, ch);
4587 is_blank = strchr(defifs, ch);
4589 if (!is_special && !is_blank) { /* ordinary char */
4591 o_addQchr(&dest, ch);
4592 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4593 || dest.o_assignment == WORD_IS_KEYWORD)
4595 && is_well_formed_var_name(dest.data, '=')
4597 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4598 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4604 if (done_word(&dest, &ctx)) {
4608 /* Is this a case when newline is simply ignored?
4610 * "cmd | <newline> cmd ..."
4611 * "case ... in <newline> word) ..."
4613 if (IS_NULL_CMD(ctx.command)
4614 && dest.length == 0 && !dest.has_quoted_part
4616 /* This newline can be ignored. But...
4617 * Without check #1, interactive shell
4618 * ignores even bare <newline>,
4619 * and shows the continuation prompt:
4620 * ps1_prompt$ <enter>
4621 * ps2> _ <=== wrong, should be ps1
4622 * Without check #2, "cmd & <newline>"
4623 * is similarly mistreated.
4624 * (BTW, this makes "cmd & cmd"
4625 * and "cmd && cmd" non-orthogonal.
4626 * Really, ask yourself, why
4627 * "cmd && <newline>" doesn't start
4628 * cmd but waits for more input?
4631 struct pipe *pi = ctx.list_head;
4632 if (pi->num_cmds != 0 /* check #1 */
4633 && pi->followup != PIPE_BG /* check #2 */
4638 /* Treat newline as a command separator. */
4639 done_pipe(&ctx, PIPE_SEQ);
4640 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4642 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4647 dest.o_assignment = MAYBE_ASSIGNMENT;
4648 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4650 /* note: if (is_blank) continue;
4651 * will still trigger for us */
4655 /* "cmd}" or "cmd }..." without semicolon or &:
4656 * } is an ordinary char in this case, even inside { cmd; }
4657 * Pathological example: { ""}; } should exec "}" cmd
4660 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4661 || dest.length != 0 /* word} */
4662 || dest.has_quoted_part /* ""} */
4666 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4667 goto skip_end_trigger;
4668 /* else: } does terminate a group */
4671 if (end_trigger && end_trigger == ch
4672 && (ch != ';' || heredoc_cnt == 0)
4673 #if ENABLE_HUSH_CASE
4675 || ctx.ctx_res_w != RES_MATCH
4676 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4681 /* This is technically valid:
4682 * { cat <<HERE; }; echo Ok
4686 * but we don't support this.
4687 * We require heredoc to be in enclosing {}/(),
4690 syntax_error_unterm_str("here document");
4693 if (done_word(&dest, &ctx)) {
4696 done_pipe(&ctx, PIPE_SEQ);
4697 dest.o_assignment = MAYBE_ASSIGNMENT;
4698 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4699 /* Do we sit outside of any if's, loops or case's? */
4701 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4705 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4707 *pstring = ctx.as_string.data;
4709 o_free_unsafe(&ctx.as_string);
4712 debug_printf_parse("parse_stream return %p: "
4713 "end_trigger char found\n",
4715 return ctx.list_head;
4722 /* Catch <, > before deciding whether this word is
4723 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4726 redir_fd = redirect_opt_num(&dest);
4727 if (done_word(&dest, &ctx)) {
4730 redir_style = REDIRECT_OVERWRITE;
4732 redir_style = REDIRECT_APPEND;
4733 ch = i_getch(input);
4734 nommu_addchr(&ctx.as_string, ch);
4737 else if (next == '(') {
4738 syntax_error(">(process) not supported");
4742 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4744 continue; /* back to top of while (1) */
4746 redir_fd = redirect_opt_num(&dest);
4747 if (done_word(&dest, &ctx)) {
4750 redir_style = REDIRECT_INPUT;
4752 redir_style = REDIRECT_HEREDOC;
4754 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4755 ch = i_getch(input);
4756 nommu_addchr(&ctx.as_string, ch);
4757 } else if (next == '>') {
4758 redir_style = REDIRECT_IO;
4759 ch = i_getch(input);
4760 nommu_addchr(&ctx.as_string, ch);
4763 else if (next == '(') {
4764 syntax_error("<(process) not supported");
4768 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4770 continue; /* back to top of while (1) */
4772 if (dest.length == 0 && !dest.has_quoted_part) {
4773 /* skip "#comment" */
4776 if (ch == EOF || ch == '\n')
4779 /* note: we do not add it to &ctx.as_string */
4781 nommu_addchr(&ctx.as_string, '\n');
4782 continue; /* back to top of while (1) */
4787 /* It's "\<newline>" */
4789 /* Remove trailing '\' from ctx.as_string */
4790 ctx.as_string.data[--ctx.as_string.length] = '\0';
4792 ch = i_getch(input); /* eat it */
4793 continue; /* back to top of while (1) */
4798 if (dest.o_assignment == MAYBE_ASSIGNMENT
4799 /* check that we are not in word in "a=1 2>word b=1": */
4800 && !ctx.pending_redirect
4802 /* ch is a special char and thus this word
4803 * cannot be an assignment */
4804 dest.o_assignment = NOT_ASSIGNMENT;
4805 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4808 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4811 case '#': /* non-comment #: "echo a#b" etc */
4812 o_addQchr(&dest, ch);
4816 syntax_error("\\<eof>");
4819 ch = i_getch(input);
4820 /* note: ch != '\n' (that case does not reach this place) */
4821 o_addchr(&dest, '\\');
4822 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4823 o_addchr(&dest, ch);
4824 nommu_addchr(&ctx.as_string, ch);
4825 /* Example: echo Hello \2>file
4826 * we need to know that word 2 is quoted */
4827 dest.has_quoted_part = 1;
4830 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4831 debug_printf_parse("parse_stream parse error: "
4832 "parse_dollar returned 0 (error)\n");
4837 dest.has_quoted_part = 1;
4838 if (next == '\'' && !ctx.pending_redirect) {
4839 insert_empty_quoted_str_marker:
4840 nommu_addchr(&ctx.as_string, next);
4841 i_getch(input); /* eat second ' */
4842 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4843 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4846 ch = i_getch(input);
4848 syntax_error_unterm_ch('\'');
4851 nommu_addchr(&ctx.as_string, ch);
4854 o_addqchr(&dest, ch);
4859 dest.has_quoted_part = 1;
4860 if (next == '"' && !ctx.pending_redirect)
4861 goto insert_empty_quoted_str_marker;
4862 if (dest.o_assignment == NOT_ASSIGNMENT)
4863 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4864 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4866 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4868 #if ENABLE_HUSH_TICK
4870 USE_FOR_NOMMU(unsigned pos;)
4872 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4873 o_addchr(&dest, '`');
4874 USE_FOR_NOMMU(pos = dest.length;)
4875 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4878 o_addstr(&ctx.as_string, dest.data + pos);
4879 o_addchr(&ctx.as_string, '`');
4881 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4882 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4887 #if ENABLE_HUSH_CASE
4890 if (done_word(&dest, &ctx)) {
4893 done_pipe(&ctx, PIPE_SEQ);
4894 #if ENABLE_HUSH_CASE
4895 /* Eat multiple semicolons, detect
4896 * whether it means something special */
4901 ch = i_getch(input);
4902 nommu_addchr(&ctx.as_string, ch);
4903 if (ctx.ctx_res_w == RES_CASE_BODY) {
4904 ctx.ctx_dsemicolon = 1;
4905 ctx.ctx_res_w = RES_MATCH;
4911 /* We just finished a cmd. New one may start
4912 * with an assignment */
4913 dest.o_assignment = MAYBE_ASSIGNMENT;
4914 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4917 if (done_word(&dest, &ctx)) {
4921 ch = i_getch(input);
4922 nommu_addchr(&ctx.as_string, ch);
4923 done_pipe(&ctx, PIPE_AND);
4925 done_pipe(&ctx, PIPE_BG);
4929 if (done_word(&dest, &ctx)) {
4932 #if ENABLE_HUSH_CASE
4933 if (ctx.ctx_res_w == RES_MATCH)
4934 break; /* we are in case's "word | word)" */
4936 if (next == '|') { /* || */
4937 ch = i_getch(input);
4938 nommu_addchr(&ctx.as_string, ch);
4939 done_pipe(&ctx, PIPE_OR);
4941 /* we could pick up a file descriptor choice here
4942 * with redirect_opt_num(), but bash doesn't do it.
4943 * "echo foo 2| cat" yields "foo 2". */
4948 #if ENABLE_HUSH_CASE
4949 /* "case... in [(]word)..." - skip '(' */
4950 if (ctx.ctx_res_w == RES_MATCH
4951 && ctx.command->argv == NULL /* not (word|(... */
4952 && dest.length == 0 /* not word(... */
4953 && dest.has_quoted_part == 0 /* not ""(... */
4959 if (parse_group(&dest, &ctx, input, ch) != 0) {
4964 #if ENABLE_HUSH_CASE
4965 if (ctx.ctx_res_w == RES_MATCH)
4969 /* proper use of this character is caught by end_trigger:
4970 * if we see {, we call parse_group(..., end_trigger='}')
4971 * and it will match } earlier (not here). */
4972 syntax_error_unexpected_ch(ch);
4976 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4982 struct parse_context *pctx;
4983 IF_HAS_KEYWORDS(struct parse_context *p2;)
4985 /* Clean up allocated tree.
4986 * Sample for finding leaks on syntax error recovery path.
4987 * Run it from interactive shell, watch pmap `pidof hush`.
4988 * while if false; then false; fi; do break; fi
4989 * Samples to catch leaks at execution:
4990 * while if (true | {true;}); then echo ok; fi; do break; done
4991 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4995 /* Update pipe/command counts,
4996 * otherwise freeing may miss some */
4997 done_pipe(pctx, PIPE_SEQ);
4998 debug_printf_clean("freeing list %p from ctx %p\n",
4999 pctx->list_head, pctx);
5000 debug_print_tree(pctx->list_head, 0);
5001 free_pipe_list(pctx->list_head);
5002 debug_printf_clean("freed list %p\n", pctx->list_head);
5004 o_free_unsafe(&pctx->as_string);
5006 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5010 IF_HAS_KEYWORDS(pctx = p2;)
5011 } while (HAS_KEYWORDS && pctx);
5014 G.last_exitcode = 1;
5025 /*** Execution routines ***/
5027 /* Expansion can recurse, need forward decls: */
5028 #if !ENABLE_HUSH_BASH_COMPAT
5029 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5030 #define expand_string_to_string(str, do_unbackslash) \
5031 expand_string_to_string(str)
5033 static char *expand_string_to_string(const char *str, int do_unbackslash);
5034 #if ENABLE_HUSH_TICK
5035 static int process_command_subs(o_string *dest, const char *s);
5038 /* expand_strvec_to_strvec() takes a list of strings, expands
5039 * all variable references within and returns a pointer to
5040 * a list of expanded strings, possibly with larger number
5041 * of strings. (Think VAR="a b"; echo $VAR).
5042 * This new list is allocated as a single malloc block.
5043 * NULL-terminated list of char* pointers is at the beginning of it,
5044 * followed by strings themselves.
5045 * Caller can deallocate entire list by single free(list). */
5047 /* A horde of its helpers come first: */
5049 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5051 while (--len >= 0) {
5054 #if ENABLE_HUSH_BRACE_EXPANSION
5055 if (c == '{' || c == '}') {
5056 /* { -> \{, } -> \} */
5058 /* And now we want to add { or } and continue:
5061 * luckily, just falling throught achieves this.
5067 /* \z -> \\\z; \<eol> -> \\<eol> */
5072 o_addchr(o, *str++);
5078 /* Store given string, finalizing the word and starting new one whenever
5079 * we encounter IFS char(s). This is used for expanding variable values.
5080 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5081 * Return in *ended_with_ifs:
5082 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5084 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5086 int last_is_ifs = 0;
5091 if (!*str) /* EOL - do not finalize word */
5093 word_len = strcspn(str, G.ifs);
5095 /* We have WORD_LEN leading non-IFS chars */
5096 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5097 o_addblock(output, str, word_len);
5099 /* Protect backslashes against globbing up :)
5100 * Example: "v='\*'; echo b$v" prints "b\*"
5101 * (and does not try to glob on "*")
5103 o_addblock_duplicate_backslash(output, str, word_len);
5104 /*/ Why can't we do it easier? */
5105 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5106 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5110 if (!*str) /* EOL - do not finalize word */
5114 /* We know str here points to at least one IFS char */
5116 str += strspn(str, G.ifs); /* skip IFS chars */
5117 if (!*str) /* EOL - do not finalize word */
5120 /* Start new word... but not always! */
5121 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5122 if (output->has_quoted_part
5123 /* Case "v=' a'; echo $v":
5124 * here nothing precedes the space in $v expansion,
5125 * therefore we should not finish the word
5126 * (IOW: if there *is* word to finalize, only then do it):
5128 || (n > 0 && output->data[output->length - 1])
5130 o_addchr(output, '\0');
5131 debug_print_list("expand_on_ifs", output, n);
5132 n = o_save_ptr(output, n);
5137 *ended_with_ifs = last_is_ifs;
5138 debug_print_list("expand_on_ifs[1]", output, n);
5142 /* Helper to expand $((...)) and heredoc body. These act as if
5143 * they are in double quotes, with the exception that they are not :).
5144 * Just the rules are similar: "expand only $var and `cmd`"
5146 * Returns malloced string.
5147 * As an optimization, we return NULL if expansion is not needed.
5149 #if !ENABLE_HUSH_BASH_COMPAT
5150 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5151 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5152 encode_then_expand_string(str)
5154 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5157 struct in_str input;
5158 o_string dest = NULL_O_STRING;
5160 if (!strchr(str, '$')
5161 && !strchr(str, '\\')
5162 #if ENABLE_HUSH_TICK
5163 && !strchr(str, '`')
5169 /* We need to expand. Example:
5170 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5172 setup_string_in_str(&input, str);
5173 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5174 //TODO: error check (encode_string returns 0 on error)?
5175 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5176 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5177 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5178 o_free_unsafe(&dest);
5182 #if ENABLE_SH_MATH_SUPPORT
5183 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5185 arith_state_t math_state;
5189 math_state.lookupvar = get_local_var_value;
5190 math_state.setvar = set_local_var_from_halves;
5191 //math_state.endofname = endofname;
5192 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5193 res = arith(&math_state, exp_str ? exp_str : arg);
5196 *errmsg_p = math_state.errmsg;
5197 if (math_state.errmsg)
5198 die_if_script(math_state.errmsg);
5203 #if ENABLE_HUSH_BASH_COMPAT
5204 /* ${var/[/]pattern[/repl]} helpers */
5205 static char *strstr_pattern(char *val, const char *pattern, int *size)
5208 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5209 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5216 /* Optimization: if "*pat" did not match the start of "string",
5217 * we know that "tring", "ring" etc will not match too:
5219 if (pattern[0] == '*')
5224 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5226 char *result = NULL;
5227 unsigned res_len = 0;
5228 unsigned repl_len = strlen(repl);
5232 char *s = strstr_pattern(val, pattern, &size);
5236 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5237 memcpy(result + res_len, val, s - val);
5239 strcpy(result + res_len, repl);
5240 res_len += repl_len;
5241 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5247 if (val[0] && result) {
5248 result = xrealloc(result, res_len + strlen(val) + 1);
5249 strcpy(result + res_len, val);
5250 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5252 debug_printf_varexp("result:'%s'\n", result);
5258 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5260 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5262 const char *val = NULL;
5263 char *to_be_freed = NULL;
5268 char exp_save = exp_save; /* for compiler */
5269 char *exp_saveptr; /* points to expansion operator */
5270 char *exp_word = exp_word; /* for compiler */
5273 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5275 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5277 first_char = arg[0] = arg0 & 0x7f;
5280 if (first_char == '#' /* ${#... */
5281 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5283 /* It must be length operator: ${#var} */
5287 /* Maybe handle parameter expansion */
5288 if (exp_saveptr /* if 2nd char is one of expansion operators */
5289 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5291 /* ${?:0}, ${#[:]%0} etc */
5292 exp_saveptr = var + 1;
5294 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5295 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5297 exp_op = exp_save = *exp_saveptr;
5299 exp_word = exp_saveptr + 1;
5300 if (exp_op == ':') {
5301 exp_op = *exp_word++;
5302 //TODO: try ${var:} and ${var:bogus} in non-bash config
5303 if (ENABLE_HUSH_BASH_COMPAT
5304 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5306 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5311 *exp_saveptr = '\0';
5312 } /* else: it's not an expansion op, but bare ${var} */
5315 /* Look up the variable in question */
5316 if (isdigit(var[0])) {
5317 /* parse_dollar should have vetted var for us */
5318 int n = xatoi_positive(var);
5319 if (n < G.global_argc)
5320 val = G.global_argv[n];
5321 /* else val remains NULL: $N with too big N */
5325 val = utoa(G.root_pid);
5327 case '!': /* bg pid */
5328 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5330 case '?': /* exitcode */
5331 val = utoa(G.last_exitcode);
5333 case '#': /* argc */
5334 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5337 val = get_local_var_value(var);
5341 /* Handle any expansions */
5342 if (exp_op == 'L') {
5343 reinit_unicode_for_hush();
5344 debug_printf_expand("expand: length(%s)=", val);
5345 val = utoa(val ? unicode_strlen(val) : 0);
5346 debug_printf_expand("%s\n", val);
5347 } else if (exp_op) {
5348 if (exp_op == '%' || exp_op == '#') {
5349 /* Standard-mandated substring removal ops:
5350 * ${parameter%word} - remove smallest suffix pattern
5351 * ${parameter%%word} - remove largest suffix pattern
5352 * ${parameter#word} - remove smallest prefix pattern
5353 * ${parameter##word} - remove largest prefix pattern
5355 * Word is expanded to produce a glob pattern.
5356 * Then var's value is matched to it and matching part removed.
5358 if (val && val[0]) {
5362 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5363 if (exp_op == *exp_word) /* ## or %% */
5365 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5367 exp_word = exp_exp_word;
5368 /* HACK ALERT. We depend here on the fact that
5369 * G.global_argv and results of utoa and get_local_var_value
5370 * are actually in writable memory:
5371 * scan_and_match momentarily stores NULs there. */
5373 loc = scan_and_match(t, exp_word, scan_flags);
5374 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5375 // exp_op, t, exp_word, loc);
5377 if (loc) { /* match was found */
5378 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5379 val = loc; /* take right part */
5381 val = to_be_freed = xstrndup(val, loc - val); /* left */
5385 #if ENABLE_HUSH_BASH_COMPAT
5386 else if (exp_op == '/' || exp_op == '\\') {
5387 /* It's ${var/[/]pattern[/repl]} thing.
5388 * Note that in encoded form it has TWO parts:
5389 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5390 * and if // is used, it is encoded as \:
5391 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5393 /* Empty variable always gives nothing: */
5394 // "v=''; echo ${v/*/w}" prints "", not "w"
5395 if (val && val[0]) {
5396 /* pattern uses non-standard expansion.
5397 * repl should be unbackslashed and globbed
5398 * by the usual expansion rules:
5400 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5401 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5402 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5403 * v='a bz'; echo ${v/a*z/\z} prints "z"
5404 * (note that a*z _pattern_ is never globbed!)
5406 char *pattern, *repl, *t;
5407 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5409 pattern = xstrdup(exp_word);
5410 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5411 *p++ = SPECIAL_VAR_SYMBOL;
5413 p = strchr(p, SPECIAL_VAR_SYMBOL);
5415 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5416 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5417 /* HACK ALERT. We depend here on the fact that
5418 * G.global_argv and results of utoa and get_local_var_value
5419 * are actually in writable memory:
5420 * replace_pattern momentarily stores NULs there. */
5422 to_be_freed = replace_pattern(t,
5424 (repl ? repl : exp_word),
5426 if (to_be_freed) /* at least one replace happened */
5433 else if (exp_op == ':') {
5434 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5435 /* It's ${var:N[:M]} bashism.
5436 * Note that in encoded form it has TWO parts:
5437 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5442 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5445 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5446 *p++ = SPECIAL_VAR_SYMBOL;
5448 p = strchr(p, SPECIAL_VAR_SYMBOL);
5450 len = expand_and_evaluate_arith(exp_word, &errmsg);
5453 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5454 if (len >= 0) { /* bash compat: len < 0 is illegal */
5455 if (beg < 0) /* bash compat */
5457 debug_printf_varexp("from val:'%s'\n", val);
5458 if (len == 0 || !val || beg >= strlen(val)) {
5462 /* Paranoia. What if user entered 9999999999999
5463 * which fits in arith_t but not int? */
5466 val = to_be_freed = xstrndup(val + beg, len);
5468 debug_printf_varexp("val:'%s'\n", val);
5472 die_if_script("malformed ${%s:...}", var);
5475 } else { /* one of "-=+?" */
5476 /* Standard-mandated substitution ops:
5477 * ${var?word} - indicate error if unset
5478 * If var is unset, word (or a message indicating it is unset
5479 * if word is null) is written to standard error
5480 * and the shell exits with a non-zero exit status.
5481 * Otherwise, the value of var is substituted.
5482 * ${var-word} - use default value
5483 * If var is unset, word is substituted.
5484 * ${var=word} - assign and use default value
5485 * If var is unset, word is assigned to var.
5486 * In all cases, final value of var is substituted.
5487 * ${var+word} - use alternative value
5488 * If var is unset, null is substituted.
5489 * Otherwise, word is substituted.
5491 * Word is subjected to tilde expansion, parameter expansion,
5492 * command substitution, and arithmetic expansion.
5493 * If word is not needed, it is not expanded.
5495 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5496 * but also treat null var as if it is unset.
5498 int use_word = (!val || ((exp_save == ':') && !val[0]));
5500 use_word = !use_word;
5501 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5502 (exp_save == ':') ? "true" : "false", use_word);
5504 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5506 exp_word = to_be_freed;
5507 if (exp_op == '?') {
5508 /* mimic bash message */
5509 die_if_script("%s: %s",
5511 exp_word[0] ? exp_word : "parameter null or not set"
5513 //TODO: how interactive bash aborts expansion mid-command?
5518 if (exp_op == '=') {
5519 /* ${var=[word]} or ${var:=[word]} */
5520 if (isdigit(var[0]) || var[0] == '#') {
5521 /* mimic bash message */
5522 die_if_script("$%s: cannot assign in this way", var);
5525 char *new_var = xasprintf("%s=%s", var, val);
5526 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5530 } /* one of "-=+?" */
5532 *exp_saveptr = exp_save;
5538 *to_be_freed_pp = to_be_freed;
5542 /* Expand all variable references in given string, adding words to list[]
5543 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5544 * to be filled). This routine is extremely tricky: has to deal with
5545 * variables/parameters with whitespace, $* and $@, and constructs like
5546 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5547 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5549 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5550 * expansion of right-hand side of assignment == 1-element expand.
5552 char cant_be_null = 0; /* only bit 0x80 matters */
5553 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5556 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5557 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5558 debug_print_list("expand_vars_to_list", output, n);
5559 n = o_save_ptr(output, n);
5560 debug_print_list("expand_vars_to_list[0]", output, n);
5562 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5564 char *to_be_freed = NULL;
5565 const char *val = NULL;
5566 #if ENABLE_HUSH_TICK
5567 o_string subst_result = NULL_O_STRING;
5569 #if ENABLE_SH_MATH_SUPPORT
5570 char arith_buf[sizeof(arith_t)*3 + 2];
5574 o_addchr(output, '\0');
5575 n = o_save_ptr(output, n);
5579 o_addblock(output, arg, p - arg);
5580 debug_print_list("expand_vars_to_list[1]", output, n);
5582 p = strchr(p, SPECIAL_VAR_SYMBOL);
5584 /* Fetch special var name (if it is indeed one of them)
5585 * and quote bit, force the bit on if singleword expansion -
5586 * important for not getting v=$@ expand to many words. */
5587 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5589 /* Is this variable quoted and thus expansion can't be null?
5590 * "$@" is special. Even if quoted, it can still
5591 * expand to nothing (not even an empty string),
5592 * thus it is excluded. */
5593 if ((first_ch & 0x7f) != '@')
5594 cant_be_null |= first_ch;
5596 switch (first_ch & 0x7f) {
5597 /* Highest bit in first_ch indicates that var is double-quoted */
5601 if (!G.global_argv[1])
5604 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5605 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5606 while (G.global_argv[i]) {
5607 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5608 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5609 if (G.global_argv[i++][0] && G.global_argv[i]) {
5610 /* this argv[] is not empty and not last:
5611 * put terminating NUL, start new word */
5612 o_addchr(output, '\0');
5613 debug_print_list("expand_vars_to_list[2]", output, n);
5614 n = o_save_ptr(output, n);
5615 debug_print_list("expand_vars_to_list[3]", output, n);
5619 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5620 * and in this case should treat it like '$*' - see 'else...' below */
5621 if (first_ch == ('@'|0x80) /* quoted $@ */
5622 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5625 o_addQstr(output, G.global_argv[i]);
5626 if (++i >= G.global_argc)
5628 o_addchr(output, '\0');
5629 debug_print_list("expand_vars_to_list[4]", output, n);
5630 n = o_save_ptr(output, n);
5632 } else { /* quoted $* (or v="$@" case): add as one word */
5634 o_addQstr(output, G.global_argv[i]);
5635 if (!G.global_argv[++i])
5638 o_addchr(output, G.ifs[0]);
5640 output->has_quoted_part = 1;
5644 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5645 /* "Empty variable", used to make "" etc to not disappear */
5646 output->has_quoted_part = 1;
5648 cant_be_null = 0x80;
5650 #if ENABLE_HUSH_TICK
5651 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5652 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5654 /* Can't just stuff it into output o_string,
5655 * expanded result may need to be globbed
5656 * and $IFS-splitted */
5657 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5658 G.last_exitcode = process_command_subs(&subst_result, arg);
5659 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5660 val = subst_result.data;
5663 #if ENABLE_SH_MATH_SUPPORT
5664 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5667 arg++; /* skip '+' */
5668 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5669 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5670 res = expand_and_evaluate_arith(arg, NULL);
5671 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5672 sprintf(arith_buf, ARITH_FMT, res);
5678 val = expand_one_var(&to_be_freed, arg, &p);
5679 IF_HUSH_TICK(store_val:)
5680 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5681 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5682 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5683 if (val && val[0]) {
5684 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5687 } else { /* quoted $VAR, val will be appended below */
5688 output->has_quoted_part = 1;
5689 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5690 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5693 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5695 if (val && val[0]) {
5696 o_addQstr(output, val);
5700 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5701 * Do the check to avoid writing to a const string. */
5702 if (*p != SPECIAL_VAR_SYMBOL)
5703 *p = SPECIAL_VAR_SYMBOL;
5705 #if ENABLE_HUSH_TICK
5706 o_free(&subst_result);
5709 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5713 o_addchr(output, '\0');
5714 n = o_save_ptr(output, n);
5716 debug_print_list("expand_vars_to_list[a]", output, n);
5717 /* this part is literal, and it was already pre-quoted
5718 * if needed (much earlier), do not use o_addQstr here! */
5719 o_addstr_with_NUL(output, arg);
5720 debug_print_list("expand_vars_to_list[b]", output, n);
5721 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5722 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5725 /* allow to reuse list[n] later without re-growth */
5726 output->has_empty_slot = 1;
5728 o_addchr(output, '\0');
5734 static char **expand_variables(char **argv, unsigned expflags)
5738 o_string output = NULL_O_STRING;
5740 output.o_expflags = expflags;
5744 n = expand_vars_to_list(&output, n, *argv);
5747 debug_print_list("expand_variables", &output, n);
5749 /* output.data (malloced in one block) gets returned in "list" */
5750 list = o_finalize_list(&output, n);
5751 debug_print_strings("expand_variables[1]", list);
5755 static char **expand_strvec_to_strvec(char **argv)
5757 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5760 #if ENABLE_HUSH_BASH_COMPAT
5761 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5763 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5767 /* Used for expansion of right hand of assignments,
5768 * $((...)), heredocs, variable espansion parts.
5770 * NB: should NOT do globbing!
5771 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5773 static char *expand_string_to_string(const char *str, int do_unbackslash)
5775 #if !ENABLE_HUSH_BASH_COMPAT
5776 const int do_unbackslash = 1;
5778 char *argv[2], **list;
5780 debug_printf_expand("string_to_string<='%s'\n", str);
5781 /* This is generally an optimization, but it also
5782 * handles "", which otherwise trips over !list[0] check below.
5783 * (is this ever happens that we actually get str="" here?)
5785 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5786 //TODO: Can use on strings with \ too, just unbackslash() them?
5787 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5788 return xstrdup(str);
5791 argv[0] = (char*)str;
5793 list = expand_variables(argv, do_unbackslash
5794 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5795 : EXP_FLAG_SINGLEWORD
5798 if (!list[0] || list[1])
5799 bb_error_msg_and_die("BUG in varexp2");
5800 /* actually, just move string 2*sizeof(char*) bytes back */
5801 overlapping_strcpy((char*)list, list[0]);
5803 unbackslash((char*)list);
5804 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5808 /* Used for "eval" builtin */
5809 static char* expand_strvec_to_string(char **argv)
5813 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5814 /* Convert all NULs to spaces */
5819 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5820 bb_error_msg_and_die("BUG in varexp3");
5821 /* bash uses ' ' regardless of $IFS contents */
5826 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5827 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5831 static char **expand_assignments(char **argv, int count)
5836 G.expanded_assignments = p = NULL;
5837 /* Expand assignments into one string each */
5838 for (i = 0; i < count; i++) {
5839 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5841 G.expanded_assignments = NULL;
5846 static void switch_off_special_sigs(unsigned mask)
5849 while ((mask >>= 1) != 0) {
5854 if (G.traps[sig] && !G.traps[sig][0])
5855 /* trap is '', has to remain SIG_IGN */
5858 G.traps[sig] = NULL;
5860 /* We are here only if no trap or trap was not '' */
5861 install_sighandler(sig, SIG_DFL);
5867 void re_execute_shell(char ***to_free, const char *s,
5868 char *g_argv0, char **g_argv,
5869 char **builtin_argv) NORETURN;
5871 static void reset_traps_to_defaults(void)
5873 /* This function is always called in a child shell
5874 * after fork (not vfork, NOMMU doesn't use this function).
5879 /* Child shells are not interactive.
5880 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5881 * Testcase: (while :; do :; done) + ^Z should background.
5882 * Same goes for SIGTERM, SIGHUP, SIGINT.
5884 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5885 if (!G.traps && !mask)
5886 return; /* already no traps and no special sigs */
5888 /* Switch off special sigs */
5889 switch_off_special_sigs(mask);
5891 G_fatal_sig_mask = 0;
5893 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5894 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5895 * remain set in G.special_sig_mask */
5900 /* Reset all sigs to default except ones with empty traps */
5901 for (sig = 0; sig < NSIG; sig++) {
5903 continue; /* no trap: nothing to do */
5904 if (!G.traps[sig][0])
5905 continue; /* empty trap: has to remain SIG_IGN */
5906 /* sig has non-empty trap, reset it: */
5908 G.traps[sig] = NULL;
5909 /* There is no signal for trap 0 (EXIT) */
5912 install_sighandler(sig, pick_sighandler(sig));
5918 static void re_execute_shell(char ***to_free, const char *s,
5919 char *g_argv0, char **g_argv,
5920 char **builtin_argv) NORETURN;
5921 static void re_execute_shell(char ***to_free, const char *s,
5922 char *g_argv0, char **g_argv,
5923 char **builtin_argv)
5925 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5926 /* delims + 2 * (number of bytes in printed hex numbers) */
5927 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5928 char *heredoc_argv[4];
5929 struct variable *cur;
5930 # if ENABLE_HUSH_FUNCTIONS
5931 struct function *funcp;
5935 unsigned long long empty_trap_mask;
5937 if (!g_argv0) { /* heredoc */
5938 argv = heredoc_argv;
5939 argv[0] = (char *) G.argv0_for_re_execing;
5940 argv[1] = (char *) "-<";
5941 argv[2] = (char *) s;
5943 pp = &argv[3]; /* used as pointer to empty environment */
5949 if (pp) while (*pp++)
5952 empty_trap_mask = 0;
5955 for (sig = 1; sig < NSIG; sig++) {
5956 if (G.traps[sig] && !G.traps[sig][0])
5957 empty_trap_mask |= 1LL << sig;
5961 sprintf(param_buf, NOMMU_HACK_FMT
5962 , (unsigned) G.root_pid
5963 , (unsigned) G.root_ppid
5964 , (unsigned) G.last_bg_pid
5965 , (unsigned) G.last_exitcode
5968 IF_HUSH_LOOPS(, G.depth_of_loop)
5970 # undef NOMMU_HACK_FMT
5971 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5972 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5975 for (cur = G.top_var; cur; cur = cur->next) {
5976 if (!cur->flg_export || cur->flg_read_only)
5979 # if ENABLE_HUSH_FUNCTIONS
5980 for (funcp = G.top_func; funcp; funcp = funcp->next)
5986 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5987 *pp++ = (char *) G.argv0_for_re_execing;
5989 for (cur = G.top_var; cur; cur = cur->next) {
5990 if (strcmp(cur->varstr, hush_version_str) == 0)
5992 if (cur->flg_read_only) {
5993 *pp++ = (char *) "-R";
5994 *pp++ = cur->varstr;
5995 } else if (!cur->flg_export) {
5996 *pp++ = (char *) "-V";
5997 *pp++ = cur->varstr;
6000 # if ENABLE_HUSH_FUNCTIONS
6001 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6002 *pp++ = (char *) "-F";
6003 *pp++ = funcp->name;
6004 *pp++ = funcp->body_as_string;
6007 /* We can pass activated traps here. Say, -Tnn:trap_string
6009 * However, POSIX says that subshells reset signals with traps
6011 * I tested bash-3.2 and it not only does that with true subshells
6012 * of the form ( list ), but with any forked children shells.
6013 * I set trap "echo W" WINCH; and then tried:
6015 * { echo 1; sleep 20; echo 2; } &
6016 * while true; do echo 1; sleep 20; echo 2; break; done &
6017 * true | { echo 1; sleep 20; echo 2; } | cat
6019 * In all these cases sending SIGWINCH to the child shell
6020 * did not run the trap. If I add trap "echo V" WINCH;
6021 * _inside_ group (just before echo 1), it works.
6023 * I conclude it means we don't need to pass active traps here.
6025 *pp++ = (char *) "-c";
6028 while (*++builtin_argv)
6029 *pp++ = *builtin_argv;
6030 *pp++ = (char *) "";
6035 /* *pp = NULL; - is already there */
6039 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6040 /* Don't propagate SIG_IGN to the child */
6041 if (SPECIAL_JOBSTOP_SIGS != 0)
6042 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6043 execve(bb_busybox_exec_path, argv, pp);
6044 /* Fallback. Useful for init=/bin/hush usage etc */
6045 if (argv[0][0] == '/')
6046 execve(argv[0], argv, pp);
6047 xfunc_error_retval = 127;
6048 bb_error_msg_and_die("can't re-execute the shell");
6050 #endif /* !BB_MMU */
6053 static int run_and_free_list(struct pipe *pi);
6055 /* Executing from string: eval, sh -c '...'
6056 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6057 * end_trigger controls how often we stop parsing
6058 * NUL: parse all, execute, return
6059 * ';': parse till ';' or newline, execute, repeat till EOF
6061 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6063 /* Why we need empty flag?
6064 * An obscure corner case "false; ``; echo $?":
6065 * empty command in `` should still set $? to 0.
6066 * But we can't just set $? to 0 at the start,
6067 * this breaks "false; echo `echo $?`" case.
6071 struct pipe *pipe_list;
6073 #if ENABLE_HUSH_INTERACTIVE
6074 if (end_trigger == ';')
6075 inp->promptmode = 0; /* PS1 */
6077 pipe_list = parse_stream(NULL, inp, end_trigger);
6078 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6079 /* If we are in "big" script
6080 * (not in `cmd` or something similar)...
6082 if (pipe_list == ERR_PTR && end_trigger == ';') {
6083 /* Discard cached input (rest of line) */
6084 int ch = inp->last_char;
6085 while (ch != EOF && ch != '\n') {
6086 //bb_error_msg("Discarded:'%c'", ch);
6091 /* This stream isn't empty */
6095 if (!pipe_list && empty)
6096 G.last_exitcode = 0;
6099 debug_print_tree(pipe_list, 0);
6100 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6101 run_and_free_list(pipe_list);
6103 if (G_flag_return_in_progress == 1)
6108 static void parse_and_run_string(const char *s)
6110 struct in_str input;
6111 setup_string_in_str(&input, s);
6112 parse_and_run_stream(&input, '\0');
6115 static void parse_and_run_file(FILE *f)
6117 struct in_str input;
6118 setup_file_in_str(&input, f);
6119 parse_and_run_stream(&input, ';');
6122 #if ENABLE_HUSH_TICK
6123 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6128 char **to_free = NULL;
6132 pid = BB_MMU ? xfork() : xvfork();
6133 if (pid == 0) { /* child */
6134 disable_restore_tty_pgrp_on_exit();
6135 /* Process substitution is not considered to be usual
6136 * 'command execution'.
6137 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6144 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6145 close(channel[0]); /* NB: close _first_, then move fd! */
6146 xmove_fd(channel[1], 1);
6147 /* Prevent it from trying to handle ctrl-z etc */
6148 IF_HUSH_JOB(G.run_list_level = 1;)
6149 /* Awful hack for `trap` or $(trap).
6151 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6152 * contains an example where "trap" is executed in a subshell:
6154 * save_traps=$(trap)
6156 * eval "$save_traps"
6158 * Standard does not say that "trap" in subshell shall print
6159 * parent shell's traps. It only says that its output
6160 * must have suitable form, but then, in the above example
6161 * (which is not supposed to be normative), it implies that.
6163 * bash (and probably other shell) does implement it
6164 * (traps are reset to defaults, but "trap" still shows them),
6165 * but as a result, "trap" logic is hopelessly messed up:
6168 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6169 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6170 * # true | trap <--- trap is in subshell - no output (ditto)
6171 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6172 * trap -- 'echo Ho' SIGWINCH
6173 * # echo `(trap)` <--- in subshell in subshell - output
6174 * trap -- 'echo Ho' SIGWINCH
6175 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6176 * trap -- 'echo Ho' SIGWINCH
6178 * The rules when to forget and when to not forget traps
6179 * get really complex and nonsensical.
6181 * Our solution: ONLY bare $(trap) or `trap` is special.
6183 s = skip_whitespace(s);
6184 if (is_prefixed_with(s, "trap")
6185 && skip_whitespace(s + 4)[0] == '\0'
6187 static const char *const argv[] = { NULL, NULL };
6188 builtin_trap((char**)argv);
6189 fflush_all(); /* important */
6193 reset_traps_to_defaults();
6194 parse_and_run_string(s);
6195 _exit(G.last_exitcode);
6197 /* We re-execute after vfork on NOMMU. This makes this script safe:
6198 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6199 * huge=`cat BIG` # was blocking here forever
6202 re_execute_shell(&to_free,
6212 # if ENABLE_HUSH_FAST
6214 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6215 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6216 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6218 enable_restore_tty_pgrp_on_exit();
6223 return remember_FILE(xfdopen_for_read(channel[0]));
6226 /* Return code is exit status of the process that is run. */
6227 static int process_command_subs(o_string *dest, const char *s)
6230 struct in_str pipe_str;
6232 int status, ch, eol_cnt;
6234 fp = generate_stream_from_string(s, &pid);
6236 /* Now send results of command back into original context */
6237 setup_file_in_str(&pipe_str, fp);
6239 while ((ch = i_getch(&pipe_str)) != EOF) {
6245 o_addchr(dest, '\n');
6248 o_addQchr(dest, ch);
6251 debug_printf("done reading from `cmd` pipe, closing it\n");
6252 fclose_and_forget(fp);
6253 /* We need to extract exitcode. Test case
6254 * "true; echo `sleep 1; false` $?"
6256 safe_waitpid(pid, &status, 0);
6257 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6258 return WEXITSTATUS(status);
6260 #endif /* ENABLE_HUSH_TICK */
6263 static void setup_heredoc(struct redir_struct *redir)
6265 struct fd_pair pair;
6268 /* the _body_ of heredoc (misleading field name) */
6269 const char *heredoc = redir->rd_filename;
6276 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6277 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6281 len = strlen(heredoc);
6283 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6285 xmove_fd(pair.rd, redir->rd_fd);
6287 /* Try writing without forking. Newer kernels have
6288 * dynamically growing pipes. Must use non-blocking write! */
6291 written = write(pair.wr, heredoc, len);
6302 ndelay_off(pair.wr);
6304 /* Okay, pipe buffer was not big enough */
6305 /* Note: we must not create a stray child (bastard? :)
6306 * for the unsuspecting parent process. Child creates a grandchild
6307 * and exits before parent execs the process which consumes heredoc
6308 * (that exec happens after we return from this function) */
6315 disable_restore_tty_pgrp_on_exit();
6316 pid = BB_MMU ? xfork() : xvfork();
6320 close(redir->rd_fd); /* read side of the pipe */
6322 full_write(pair.wr, heredoc, len); /* may loop or block */
6325 /* Delegate blocking writes to another process */
6326 xmove_fd(pair.wr, STDOUT_FILENO);
6327 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6331 #if ENABLE_HUSH_FAST
6333 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6335 enable_restore_tty_pgrp_on_exit();
6341 wait(NULL); /* wait till child has died */
6344 /* fd: redirect wants this fd to be used (e.g. 3>file).
6345 * Move all conflicting internally used fds,
6346 * and remember them so that we can restore them later.
6348 static int save_fds_on_redirect(int fd, int squirrel[3])
6351 /* Handle redirects of fds 0,1,2 */
6353 /* If we collide with an already moved stdio fd... */
6354 if (fd == squirrel[0]) {
6355 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6358 if (fd == squirrel[1]) {
6359 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6362 if (fd == squirrel[2]) {
6363 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6366 /* If we are about to redirect stdio fd, and did not yet move it... */
6367 if (fd <= 2 && squirrel[fd] < 0) {
6368 /* We avoid taking stdio fds */
6369 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6370 if (squirrel[fd] < 0 && errno != EBADF)
6372 return 0; /* "we did not close fd" */
6376 #if ENABLE_HUSH_INTERACTIVE
6377 if (fd != 0 && fd == G.interactive_fd) {
6378 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6383 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6384 * (1) Redirect in a forked child. No need to save FILEs' fds,
6385 * we aren't going to use them anymore, ok to trash.
6386 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6387 * but how are we doing to use them?
6388 * "fileno(fd) = new_fd" can't be done.
6393 return save_FILEs_on_redirect(fd);
6396 static void restore_redirects(int squirrel[3])
6399 for (i = 0; i <= 2; i++) {
6402 /* We simply die on error */
6407 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6409 restore_redirected_FILEs();
6412 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6413 * and stderr if they are redirected. */
6414 static int setup_redirects(struct command *prog, int squirrel[])
6417 struct redir_struct *redir;
6419 for (redir = prog->redirects; redir; redir = redir->next) {
6420 if (redir->rd_type == REDIRECT_HEREDOC2) {
6421 /* "rd_fd<<HERE" case */
6422 save_fds_on_redirect(redir->rd_fd, squirrel);
6423 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6425 debug_printf_parse("set heredoc '%s'\n",
6426 redir->rd_filename);
6427 setup_heredoc(redir);
6431 if (redir->rd_dup == REDIRFD_TO_FILE) {
6432 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6434 if (redir->rd_filename == NULL) {
6437 * "cmd >" (no filename)
6438 * "cmd > <file" (2nd redirect starts too early)
6440 die_if_script("syntax error: %s", "invalid redirect");
6443 mode = redir_table[redir->rd_type].mode;
6444 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6445 openfd = open_or_warn(p, mode);
6448 /* Error message from open_or_warn can be lost
6449 * if stderr has been redirected, but bash
6450 * and ash both lose it as well
6451 * (though zsh doesn't!)
6456 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6457 openfd = redir->rd_dup;
6460 if (openfd != redir->rd_fd) {
6461 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6462 if (openfd == REDIRFD_CLOSE) {
6463 /* "rd_fd >&-" means "close me" */
6465 /* ^^^ optimization: saving may already
6466 * have closed it. If not... */
6467 close(redir->rd_fd);
6470 xdup2(openfd, redir->rd_fd);
6471 if (redir->rd_dup == REDIRFD_TO_FILE)
6472 /* "rd_fd > FILE" */
6474 /* else: "rd_fd > rd_dup" */
6481 static char *find_in_path(const char *arg)
6484 const char *PATH = get_local_var_value("PATH");
6490 const char *end = strchrnul(PATH, ':');
6491 int sz = end - PATH; /* must be int! */
6495 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6497 /* We have xxx::yyyy in $PATH,
6498 * it means "use current dir" */
6501 if (access(ret, F_OK) == 0)
6514 static const struct built_in_command *find_builtin_helper(const char *name,
6515 const struct built_in_command *x,
6516 const struct built_in_command *end)
6519 if (strcmp(name, x->b_cmd) != 0) {
6523 debug_printf_exec("found builtin '%s'\n", name);
6528 static const struct built_in_command *find_builtin1(const char *name)
6530 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6532 static const struct built_in_command *find_builtin(const char *name)
6534 const struct built_in_command *x = find_builtin1(name);
6537 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6540 #if ENABLE_HUSH_FUNCTIONS
6541 static struct function **find_function_slot(const char *name)
6543 struct function **funcpp = &G.top_func;
6545 if (strcmp(name, (*funcpp)->name) == 0) {
6548 funcpp = &(*funcpp)->next;
6553 static const struct function *find_function(const char *name)
6555 const struct function *funcp = *find_function_slot(name);
6557 debug_printf_exec("found function '%s'\n", name);
6561 /* Note: takes ownership on name ptr */
6562 static struct function *new_function(char *name)
6564 struct function **funcpp = find_function_slot(name);
6565 struct function *funcp = *funcpp;
6567 if (funcp != NULL) {
6568 struct command *cmd = funcp->parent_cmd;
6569 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6571 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6573 /* Note: if !funcp->body, do not free body_as_string!
6574 * This is a special case of "-F name body" function:
6575 * body_as_string was not malloced! */
6577 free_pipe_list(funcp->body);
6579 free(funcp->body_as_string);
6583 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6584 cmd->argv[0] = funcp->name;
6585 cmd->group = funcp->body;
6587 cmd->group_as_string = funcp->body_as_string;
6591 debug_printf_exec("remembering new function '%s'\n", name);
6592 funcp = *funcpp = xzalloc(sizeof(*funcp));
6593 /*funcp->next = NULL;*/
6600 static void unset_func(const char *name)
6602 struct function **funcpp = find_function_slot(name);
6603 struct function *funcp = *funcpp;
6605 if (funcp != NULL) {
6606 debug_printf_exec("freeing function '%s'\n", funcp->name);
6607 *funcpp = funcp->next;
6608 /* funcp is unlinked now, deleting it.
6609 * Note: if !funcp->body, the function was created by
6610 * "-F name body", do not free ->body_as_string
6611 * and ->name as they were not malloced. */
6613 free_pipe_list(funcp->body);
6616 free(funcp->body_as_string);
6624 #define exec_function(to_free, funcp, argv) \
6625 exec_function(funcp, argv)
6627 static void exec_function(char ***to_free,
6628 const struct function *funcp,
6629 char **argv) NORETURN;
6630 static void exec_function(char ***to_free,
6631 const struct function *funcp,
6637 argv[0] = G.global_argv[0];
6638 G.global_argv = argv;
6642 /* On MMU, funcp->body is always non-NULL */
6643 n = run_list(funcp->body);
6647 re_execute_shell(to_free,
6648 funcp->body_as_string,
6655 static int run_function(const struct function *funcp, char **argv)
6661 save_and_replace_G_args(&sv, argv);
6663 /* "we are in function, ok to use return" */
6664 sv_flg = G_flag_return_in_progress;
6665 G_flag_return_in_progress = -1;
6666 # if ENABLE_HUSH_LOCAL
6667 G.func_nest_level++;
6670 /* On MMU, funcp->body is always non-NULL */
6673 /* Function defined by -F */
6674 parse_and_run_string(funcp->body_as_string);
6675 rc = G.last_exitcode;
6679 rc = run_list(funcp->body);
6682 # if ENABLE_HUSH_LOCAL
6684 struct variable *var;
6685 struct variable **var_pp;
6687 var_pp = &G.top_var;
6688 while ((var = *var_pp) != NULL) {
6689 if (var->func_nest_level < G.func_nest_level) {
6690 var_pp = &var->next;
6694 if (var->flg_export)
6695 bb_unsetenv(var->varstr);
6696 /* Remove from global list */
6697 *var_pp = var->next;
6703 G.func_nest_level--;
6706 G_flag_return_in_progress = sv_flg;
6708 restore_G_args(&sv, argv);
6712 #endif /* ENABLE_HUSH_FUNCTIONS */
6716 #define exec_builtin(to_free, x, argv) \
6717 exec_builtin(x, argv)
6719 #define exec_builtin(to_free, x, argv) \
6720 exec_builtin(to_free, argv)
6722 static void exec_builtin(char ***to_free,
6723 const struct built_in_command *x,
6724 char **argv) NORETURN;
6725 static void exec_builtin(char ***to_free,
6726 const struct built_in_command *x,
6732 rcode = x->b_function(argv);
6737 /* On NOMMU, we must never block!
6738 * Example: { sleep 99 | read line; } & echo Ok
6740 re_execute_shell(to_free,
6749 static void execvp_or_die(char **argv) NORETURN;
6750 static void execvp_or_die(char **argv)
6753 debug_printf_exec("execing '%s'\n", argv[0]);
6754 /* Don't propagate SIG_IGN to the child */
6755 if (SPECIAL_JOBSTOP_SIGS != 0)
6756 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6757 execvp(argv[0], argv);
6759 if (errno == EACCES) e = 126;
6760 if (errno == ENOENT) e = 127;
6761 bb_perror_msg("can't execute '%s'", argv[0]);
6765 #if ENABLE_HUSH_MODE_X
6766 static void dump_cmd_in_x_mode(char **argv)
6768 if (G_x_mode && argv) {
6769 /* We want to output the line in one write op */
6777 len += strlen(argv[n++]) + 1;
6783 p += sprintf(p, " %s", argv[n++]);
6791 # define dump_cmd_in_x_mode(argv) ((void)0)
6795 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6796 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6797 #define pseudo_exec(nommu_save, command, argv_expanded) \
6798 pseudo_exec(command, argv_expanded)
6801 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6803 * Don't exit() here. If you don't exec, use _exit instead.
6804 * The at_exit handlers apparently confuse the calling process,
6805 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6807 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6808 char **argv, int assignment_cnt,
6809 char **argv_expanded) NORETURN;
6810 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6811 char **argv, int assignment_cnt,
6812 char **argv_expanded)
6816 new_env = expand_assignments(argv, assignment_cnt);
6817 dump_cmd_in_x_mode(new_env);
6819 if (!argv[assignment_cnt]) {
6820 /* Case when we are here: ... | var=val | ...
6821 * (note that we do not exit early, i.e., do not optimize out
6822 * expand_assignments(): think about ... | var=`sleep 1` | ...
6824 free_strings(new_env);
6825 _exit(EXIT_SUCCESS);
6829 set_vars_and_save_old(new_env);
6830 free(new_env); /* optional */
6831 /* we can also destroy set_vars_and_save_old's return value,
6834 nommu_save->new_env = new_env;
6835 nommu_save->old_vars = set_vars_and_save_old(new_env);
6838 if (argv_expanded) {
6839 argv = argv_expanded;
6841 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6843 nommu_save->argv = argv;
6846 dump_cmd_in_x_mode(argv);
6848 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6849 if (strchr(argv[0], '/') != NULL)
6853 /* Check if the command matches any of the builtins.
6854 * Depending on context, this might be redundant. But it's
6855 * easier to waste a few CPU cycles than it is to figure out
6856 * if this is one of those cases.
6859 /* On NOMMU, it is more expensive to re-execute shell
6860 * just in order to run echo or test builtin.
6861 * It's better to skip it here and run corresponding
6862 * non-builtin later. */
6863 const struct built_in_command *x;
6864 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6866 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6869 #if ENABLE_HUSH_FUNCTIONS
6870 /* Check if the command matches any functions */
6872 const struct function *funcp = find_function(argv[0]);
6874 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6879 #if ENABLE_FEATURE_SH_STANDALONE
6880 /* Check if the command matches any busybox applets */
6882 int a = find_applet_by_name(argv[0]);
6884 # if BB_MMU /* see above why on NOMMU it is not allowed */
6885 if (APPLET_IS_NOEXEC(a)) {
6886 /* Do not leak open fds from opened script files etc */
6887 close_all_FILE_list();
6888 debug_printf_exec("running applet '%s'\n", argv[0]);
6889 run_applet_no_and_exit(a, argv);
6892 /* Re-exec ourselves */
6893 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6894 /* Don't propagate SIG_IGN to the child */
6895 if (SPECIAL_JOBSTOP_SIGS != 0)
6896 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6897 execv(bb_busybox_exec_path, argv);
6898 /* If they called chroot or otherwise made the binary no longer
6899 * executable, fall through */
6904 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6907 execvp_or_die(argv);
6910 /* Called after [v]fork() in run_pipe
6912 static void pseudo_exec(nommu_save_t *nommu_save,
6913 struct command *command,
6914 char **argv_expanded) NORETURN;
6915 static void pseudo_exec(nommu_save_t *nommu_save,
6916 struct command *command,
6917 char **argv_expanded)
6919 if (command->argv) {
6920 pseudo_exec_argv(nommu_save, command->argv,
6921 command->assignment_cnt, argv_expanded);
6924 if (command->group) {
6925 /* Cases when we are here:
6928 * ... | ( list ) | ...
6929 * ... | { list } | ...
6933 debug_printf_exec("pseudo_exec: run_list\n");
6934 reset_traps_to_defaults();
6935 rcode = run_list(command->group);
6936 /* OK to leak memory by not calling free_pipe_list,
6937 * since this process is about to exit */
6940 re_execute_shell(&nommu_save->argv_from_re_execing,
6941 command->group_as_string,
6948 /* Case when we are here: ... | >file */
6949 debug_printf_exec("pseudo_exec'ed null command\n");
6950 _exit(EXIT_SUCCESS);
6954 static const char *get_cmdtext(struct pipe *pi)
6960 /* This is subtle. ->cmdtext is created only on first backgrounding.
6961 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6962 * On subsequent bg argv is trashed, but we won't use it */
6965 argv = pi->cmds[0].argv;
6966 if (!argv || !argv[0]) {
6967 pi->cmdtext = xzalloc(1);
6973 len += strlen(*argv) + 1;
6977 argv = pi->cmds[0].argv;
6979 len = strlen(*argv);
6980 memcpy(p, *argv, len);
6988 static void insert_bg_job(struct pipe *pi)
6990 struct pipe *job, **jobp;
6993 /* Linear search for the ID of the job to use */
6995 for (job = G.job_list; job; job = job->next)
6996 if (job->jobid >= pi->jobid)
6997 pi->jobid = job->jobid + 1;
6999 /* Add job to the list of running jobs */
7001 while ((job = *jobp) != NULL)
7003 job = *jobp = xmalloc(sizeof(*job));
7005 *job = *pi; /* physical copy */
7007 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7008 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7009 for (i = 0; i < pi->num_cmds; i++) {
7010 job->cmds[i].pid = pi->cmds[i].pid;
7011 /* all other fields are not used and stay zero */
7013 job->cmdtext = xstrdup(get_cmdtext(pi));
7015 if (G_interactive_fd)
7016 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
7017 G.last_jobid = job->jobid;
7020 static void remove_bg_job(struct pipe *pi)
7022 struct pipe *prev_pipe;
7024 if (pi == G.job_list) {
7025 G.job_list = pi->next;
7027 prev_pipe = G.job_list;
7028 while (prev_pipe->next != pi)
7029 prev_pipe = prev_pipe->next;
7030 prev_pipe->next = pi->next;
7033 G.last_jobid = G.job_list->jobid;
7038 /* Remove a backgrounded job */
7039 static void delete_finished_bg_job(struct pipe *pi)
7046 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7053 dead = WIFEXITED(status) || WIFSIGNALED(status);
7056 if (WIFSTOPPED(status))
7057 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7058 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7059 if (WIFSIGNALED(status))
7060 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7061 childpid, WTERMSIG(status), WEXITSTATUS(status));
7062 if (WIFEXITED(status))
7063 debug_printf_jobs("pid %d exited, exitcode %d\n",
7064 childpid, WEXITSTATUS(status));
7066 /* Were we asked to wait for a fg pipe? */
7068 i = fg_pipe->num_cmds;
7070 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7071 if (fg_pipe->cmds[i].pid != childpid)
7075 fg_pipe->cmds[i].pid = 0;
7076 fg_pipe->alive_cmds--;
7077 ex = WEXITSTATUS(status);
7078 /* bash prints killer signal's name for *last*
7079 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7080 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7082 if (WIFSIGNALED(status)) {
7083 int sig = WTERMSIG(status);
7084 if (i == fg_pipe->num_cmds-1)
7085 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7086 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7087 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7088 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7089 * Maybe we need to use sig | 128? */
7092 fg_pipe->cmds[i].cmd_exitcode = ex;
7094 fg_pipe->stopped_cmds++;
7096 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7097 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7098 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
7099 /* All processes in fg pipe have exited or stopped */
7101 i = fg_pipe->num_cmds;
7103 rcode = fg_pipe->cmds[i].cmd_exitcode;
7104 /* usually last process gives overall exitstatus,
7105 * but with "set -o pipefail", last *failed* process does */
7106 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7109 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
7110 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7111 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7112 * and "killall -STOP cat" */
7113 if (G_interactive_fd) {
7115 if (fg_pipe->alive_cmds != 0)
7116 insert_bg_job(fg_pipe);
7120 if (fg_pipe->alive_cmds == 0)
7123 /* There are still running processes in the fg_pipe */
7126 /* It wasnt in fg_pipe, look for process in bg pipes */
7130 /* We were asked to wait for bg or orphaned children */
7131 /* No need to remember exitcode in this case */
7132 for (pi = G.job_list; pi; pi = pi->next) {
7133 for (i = 0; i < pi->num_cmds; i++) {
7134 if (pi->cmds[i].pid == childpid)
7135 goto found_pi_and_prognum;
7138 /* Happens when shell is used as init process (init=/bin/sh) */
7139 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7140 return -1; /* this wasn't a process from fg_pipe */
7142 found_pi_and_prognum:
7145 pi->cmds[i].pid = 0;
7146 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7147 if (WIFSIGNALED(status))
7148 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7150 if (!pi->alive_cmds) {
7151 if (G_interactive_fd)
7152 printf(JOB_STATUS_FORMAT, pi->jobid,
7153 "Done", pi->cmdtext);
7154 delete_finished_bg_job(pi);
7161 return -1; /* this wasn't a process from fg_pipe */
7164 /* Check to see if any processes have exited -- if they have,
7165 * figure out why and see if a job has completed.
7166 * Alternatively (fg_pipe == NULL, waitfor_pid != 0),
7167 * wait for a specific pid to complete, return exitcode+1
7168 * (this allows to distinguish zero as "no children exited" result).
7170 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7176 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7178 attributes = WUNTRACED;
7179 if (fg_pipe == NULL)
7180 attributes |= WNOHANG;
7183 #if ENABLE_HUSH_FAST
7184 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7185 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7186 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7187 /* There was neither fork nor SIGCHLD since last waitpid */
7188 /* Avoid doing waitpid syscall if possible */
7189 if (!G.we_have_children) {
7193 if (fg_pipe == NULL) { /* is WNOHANG set? */
7194 /* We have children, but they did not exit
7195 * or stop yet (we saw no SIGCHLD) */
7198 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7202 /* Do we do this right?
7203 * bash-3.00# sleep 20 | false
7205 * [3]+ Stopped sleep 20 | false
7206 * bash-3.00# echo $?
7207 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7208 * [hush 1.14.0: yes we do it right]
7212 #if ENABLE_HUSH_FAST
7214 i = G.count_SIGCHLD;
7216 childpid = waitpid(-1, &status, attributes);
7217 if (childpid <= 0) {
7218 if (childpid && errno != ECHILD)
7219 bb_perror_msg("waitpid");
7220 #if ENABLE_HUSH_FAST
7221 else { /* Until next SIGCHLD, waitpid's are useless */
7222 G.we_have_children = (childpid == 0);
7223 G.handled_SIGCHLD = i;
7224 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7227 /* ECHILD (no children), or 0 (no change in children status) */
7231 rcode = process_wait_result(fg_pipe, childpid, status);
7233 /* fg_pipe exited or stopped */
7236 if (childpid == waitfor_pid) {
7237 rcode = WEXITSTATUS(status);
7238 if (WIFSIGNALED(status))
7239 rcode = 128 + WTERMSIG(status);
7241 break; /* "wait PID" called us, give it exitcode+1 */
7243 /* This wasn't one of our processes, or */
7244 /* fg_pipe still has running processes, do waitpid again */
7245 } /* while (waitpid succeeds)... */
7251 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7254 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7255 if (G_saved_tty_pgrp) {
7256 /* Job finished, move the shell to the foreground */
7257 p = getpgrp(); /* our process group id */
7258 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7259 tcsetpgrp(G_interactive_fd, p);
7265 /* Start all the jobs, but don't wait for anything to finish.
7268 * Return code is normally -1, when the caller has to wait for children
7269 * to finish to determine the exit status of the pipe. If the pipe
7270 * is a simple builtin command, however, the action is done by the
7271 * time run_pipe returns, and the exit code is provided as the
7274 * Returns -1 only if started some children. IOW: we have to
7275 * mask out retvals of builtins etc with 0xff!
7277 * The only case when we do not need to [v]fork is when the pipe
7278 * is single, non-backgrounded, non-subshell command. Examples:
7279 * cmd ; ... { list } ; ...
7280 * cmd && ... { list } && ...
7281 * cmd || ... { list } || ...
7282 * If it is, then we can run cmd as a builtin, NOFORK,
7283 * or (if SH_STANDALONE) an applet, and we can run the { list }
7284 * with run_list. If it isn't one of these, we fork and exec cmd.
7286 * Cases when we must fork:
7287 * non-single: cmd | cmd
7288 * backgrounded: cmd & { list } &
7289 * subshell: ( list ) [&]
7291 #if !ENABLE_HUSH_MODE_X
7292 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7293 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7295 static int redirect_and_varexp_helper(char ***new_env_p,
7296 struct variable **old_vars_p,
7297 struct command *command,
7299 char **argv_expanded)
7301 /* setup_redirects acts on file descriptors, not FILEs.
7302 * This is perfect for work that comes after exec().
7303 * Is it really safe for inline use? Experimentally,
7304 * things seem to work. */
7305 int rcode = setup_redirects(command, squirrel);
7307 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7308 *new_env_p = new_env;
7309 dump_cmd_in_x_mode(new_env);
7310 dump_cmd_in_x_mode(argv_expanded);
7312 *old_vars_p = set_vars_and_save_old(new_env);
7316 static NOINLINE int run_pipe(struct pipe *pi)
7318 static const char *const null_ptr = NULL;
7322 struct command *command;
7323 char **argv_expanded;
7325 /* it is not always needed, but we aim to smaller code */
7326 int squirrel[] = { -1, -1, -1 };
7329 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7332 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7333 * Result should be 3 lines: q w e, qwe, q w e
7335 G.ifs = get_local_var_value("IFS");
7339 IF_HUSH_JOB(pi->pgrp = -1;)
7340 pi->stopped_cmds = 0;
7341 command = &pi->cmds[0];
7342 argv_expanded = NULL;
7344 if (pi->num_cmds != 1
7345 || pi->followup == PIPE_BG
7346 || command->cmd_type == CMD_SUBSHELL
7353 debug_printf_exec(": group:%p argv:'%s'\n",
7354 command->group, command->argv ? command->argv[0] : "NONE");
7356 if (command->group) {
7357 #if ENABLE_HUSH_FUNCTIONS
7358 if (command->cmd_type == CMD_FUNCDEF) {
7359 /* "executing" func () { list } */
7360 struct function *funcp;
7362 funcp = new_function(command->argv[0]);
7363 /* funcp->name is already set to argv[0] */
7364 funcp->body = command->group;
7366 funcp->body_as_string = command->group_as_string;
7367 command->group_as_string = NULL;
7369 command->group = NULL;
7370 command->argv[0] = NULL;
7371 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7372 funcp->parent_cmd = command;
7373 command->child_func = funcp;
7375 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7377 return EXIT_SUCCESS;
7381 debug_printf("non-subshell group\n");
7382 rcode = 1; /* exitcode if redir failed */
7383 if (setup_redirects(command, squirrel) == 0) {
7384 debug_printf_exec(": run_list\n");
7385 rcode = run_list(command->group) & 0xff;
7387 restore_redirects(squirrel);
7388 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7390 debug_printf_exec("run_pipe: return %d\n", rcode);
7394 argv = command->argv ? command->argv : (char **) &null_ptr;
7396 const struct built_in_command *x;
7397 #if ENABLE_HUSH_FUNCTIONS
7398 const struct function *funcp;
7402 char **new_env = NULL;
7403 struct variable *old_vars = NULL;
7405 if (argv[command->assignment_cnt] == NULL) {
7406 /* Assignments, but no command */
7407 /* Ensure redirects take effect (that is, create files).
7408 * Try "a=t >file" */
7409 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7410 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7411 /* Set shell variables */
7415 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7416 /* Do we need to flag set_local_var() errors?
7417 * "assignment to readonly var" and "putenv error"
7422 /* Redirect error sets $? to 1. Otherwise,
7423 * if evaluating assignment value set $?, retain it.
7424 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7426 rcode = G.last_exitcode;
7427 /* Exit, _skipping_ variable restoring code: */
7428 goto clean_up_and_ret0;
7430 #else /* Older, bigger, but more correct code */
7432 rcode = setup_redirects(command, squirrel);
7433 restore_redirects(squirrel);
7434 /* Set shell variables */
7436 bb_putchar_stderr('+');
7438 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7440 fprintf(stderr, " %s", p);
7441 debug_printf_exec("set shell var:'%s'->'%s'\n",
7443 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7444 /* Do we need to flag set_local_var() errors?
7445 * "assignment to readonly var" and "putenv error"
7450 bb_putchar_stderr('\n');
7451 /* Redirect error sets $? to 1. Otherwise,
7452 * if evaluating assignment value set $?, retain it.
7453 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7455 rcode = G.last_exitcode;
7456 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7458 debug_printf_exec("run_pipe: return %d\n", rcode);
7463 /* Expand the rest into (possibly) many strings each */
7464 #if ENABLE_HUSH_BASH_COMPAT
7465 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7466 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7470 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7473 /* if someone gives us an empty string: `cmd with empty output` */
7474 if (!argv_expanded[0]) {
7475 free(argv_expanded);
7477 return G.last_exitcode;
7480 x = find_builtin(argv_expanded[0]);
7481 #if ENABLE_HUSH_FUNCTIONS
7484 funcp = find_function(argv_expanded[0]);
7488 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7489 debug_printf("exec with redirects only\n");
7490 rcode = setup_redirects(command, NULL);
7491 /* rcode=1 can be if redir file can't be opened */
7492 goto clean_up_and_ret1;
7495 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7498 debug_printf_exec(": builtin '%s' '%s'...\n",
7499 x->b_cmd, argv_expanded[1]);
7501 rcode = x->b_function(argv_expanded) & 0xff;
7504 #if ENABLE_HUSH_FUNCTIONS
7506 # if ENABLE_HUSH_LOCAL
7507 struct variable **sv;
7508 sv = G.shadowed_vars_pp;
7509 G.shadowed_vars_pp = &old_vars;
7511 debug_printf_exec(": function '%s' '%s'...\n",
7512 funcp->name, argv_expanded[1]);
7513 rcode = run_function(funcp, argv_expanded) & 0xff;
7514 # if ENABLE_HUSH_LOCAL
7515 G.shadowed_vars_pp = sv;
7521 unset_vars(new_env);
7523 /* clean_up_and_ret0: */
7524 restore_redirects(squirrel);
7526 free(argv_expanded);
7527 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7529 debug_printf_exec("run_pipe return %d\n", rcode);
7533 if (ENABLE_FEATURE_SH_NOFORK) {
7534 int n = find_applet_by_name(argv_expanded[0]);
7535 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7536 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7538 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7539 argv_expanded[0], argv_expanded[1]);
7540 rcode = run_nofork_applet(n, argv_expanded);
7542 goto clean_up_and_ret;
7545 /* It is neither builtin nor applet. We must fork. */
7549 /* NB: argv_expanded may already be created, and that
7550 * might include `cmd` runs! Do not rerun it! We *must*
7551 * use argv_expanded if it's non-NULL */
7553 /* Going to fork a child per each pipe member */
7558 while (cmd_no < pi->num_cmds) {
7559 struct fd_pair pipefds;
7561 volatile nommu_save_t nommu_save;
7562 nommu_save.new_env = NULL;
7563 nommu_save.old_vars = NULL;
7564 nommu_save.argv = NULL;
7565 nommu_save.argv_from_re_execing = NULL;
7567 command = &pi->cmds[cmd_no];
7569 if (command->argv) {
7570 debug_printf_exec(": pipe member '%s' '%s'...\n",
7571 command->argv[0], command->argv[1]);
7573 debug_printf_exec(": pipe member with no argv\n");
7576 /* pipes are inserted between pairs of commands */
7579 if (cmd_no < pi->num_cmds)
7580 xpiped_pair(pipefds);
7582 command->pid = BB_MMU ? fork() : vfork();
7583 if (!command->pid) { /* child */
7585 disable_restore_tty_pgrp_on_exit();
7586 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7588 /* Every child adds itself to new process group
7589 * with pgid == pid_of_first_child_in_pipe */
7590 if (G.run_list_level == 1 && G_interactive_fd) {
7593 if (pgrp < 0) /* true for 1st process only */
7595 if (setpgid(0, pgrp) == 0
7596 && pi->followup != PIPE_BG
7597 && G_saved_tty_pgrp /* we have ctty */
7599 /* We do it in *every* child, not just first,
7601 tcsetpgrp(G_interactive_fd, pgrp);
7605 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7606 /* 1st cmd in backgrounded pipe
7607 * should have its stdin /dev/null'ed */
7609 if (open(bb_dev_null, O_RDONLY))
7610 xopen("/", O_RDONLY);
7612 xmove_fd(next_infd, 0);
7614 xmove_fd(pipefds.wr, 1);
7617 /* Like bash, explicit redirects override pipes,
7618 * and the pipe fd (fd#1) is available for dup'ing:
7619 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7620 * of cmd1 goes into pipe.
7622 if (setup_redirects(command, NULL)) {
7623 /* Happens when redir file can't be opened:
7624 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7626 * hush: can't open '/qwe/rty': No such file or directory
7628 * (echo BAR is not executed, it hits _exit(1) below)
7633 /* Stores to nommu_save list of env vars putenv'ed
7634 * (NOMMU, on MMU we don't need that) */
7635 /* cast away volatility... */
7636 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7637 /* pseudo_exec() does not return */
7640 /* parent or error */
7641 #if ENABLE_HUSH_FAST
7643 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7645 enable_restore_tty_pgrp_on_exit();
7647 /* Clean up after vforked child */
7648 free(nommu_save.argv);
7649 free(nommu_save.argv_from_re_execing);
7650 unset_vars(nommu_save.new_env);
7651 add_vars(nommu_save.old_vars);
7653 free(argv_expanded);
7654 argv_expanded = NULL;
7655 if (command->pid < 0) { /* [v]fork failed */
7656 /* Clearly indicate, was it fork or vfork */
7657 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7661 /* Second and next children need to know pid of first one */
7663 pi->pgrp = command->pid;
7669 if (cmd_no < pi->num_cmds)
7671 /* Pass read (output) pipe end to next iteration */
7672 next_infd = pipefds.rd;
7675 if (!pi->alive_cmds) {
7677 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7682 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7686 /* NB: called by pseudo_exec, and therefore must not modify any
7687 * global data until exec/_exit (we can be a child after vfork!) */
7688 static int run_list(struct pipe *pi)
7690 #if ENABLE_HUSH_CASE
7691 char *case_word = NULL;
7693 #if ENABLE_HUSH_LOOPS
7694 struct pipe *loop_top = NULL;
7695 char **for_lcur = NULL;
7696 char **for_list = NULL;
7698 smallint last_followup;
7700 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7701 smalluint cond_code = 0;
7703 enum { cond_code = 0 };
7706 smallint rword; /* RES_foo */
7707 smallint last_rword; /* ditto */
7710 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7713 #if ENABLE_HUSH_LOOPS
7714 /* Check syntax for "for" */
7717 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7718 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7720 /* current word is FOR or IN (BOLD in comments below) */
7721 if (cpipe->next == NULL) {
7722 syntax_error("malformed for");
7724 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7727 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7728 if (cpipe->next->res_word == RES_DO)
7730 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7731 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7732 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7734 syntax_error("malformed for");
7736 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7743 /* Past this point, all code paths should jump to ret: label
7744 * in order to return, no direct "return" statements please.
7745 * This helps to ensure that no memory is leaked. */
7753 last_rword = RES_XXXX;
7755 last_followup = PIPE_SEQ;
7756 rcode = G.last_exitcode;
7758 /* Go through list of pipes, (maybe) executing them. */
7759 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7762 if (G_flag_return_in_progress == 1)
7765 IF_HAS_KEYWORDS(rword = pi->res_word;)
7766 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7767 rword, cond_code, last_rword);
7768 #if ENABLE_HUSH_LOOPS
7769 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7770 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7772 /* start of a loop: remember where loop starts */
7777 /* Still in the same "if...", "then..." or "do..." branch? */
7778 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7779 if ((rcode == 0 && last_followup == PIPE_OR)
7780 || (rcode != 0 && last_followup == PIPE_AND)
7782 /* It is "<true> || CMD" or "<false> && CMD"
7783 * and we should not execute CMD */
7784 debug_printf_exec("skipped cmd because of || or &&\n");
7785 last_followup = pi->followup;
7786 goto dont_check_jobs_but_continue;
7789 last_followup = pi->followup;
7790 IF_HAS_KEYWORDS(last_rword = rword;)
7793 if (rword == RES_THEN) {
7794 /* if false; then ... fi has exitcode 0! */
7795 G.last_exitcode = rcode = EXIT_SUCCESS;
7796 /* "if <false> THEN cmd": skip cmd */
7800 if (rword == RES_ELSE || rword == RES_ELIF) {
7801 /* "if <true> then ... ELSE/ELIF cmd":
7802 * skip cmd and all following ones */
7807 #if ENABLE_HUSH_LOOPS
7808 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7810 /* first loop through for */
7812 static const char encoded_dollar_at[] ALIGN1 = {
7813 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7814 }; /* encoded representation of "$@" */
7815 static const char *const encoded_dollar_at_argv[] = {
7816 encoded_dollar_at, NULL
7817 }; /* argv list with one element: "$@" */
7820 vals = (char**)encoded_dollar_at_argv;
7821 if (pi->next->res_word == RES_IN) {
7822 /* if no variable values after "in" we skip "for" */
7823 if (!pi->next->cmds[0].argv) {
7824 G.last_exitcode = rcode = EXIT_SUCCESS;
7825 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7828 vals = pi->next->cmds[0].argv;
7829 } /* else: "for var; do..." -> assume "$@" list */
7830 /* create list of variable values */
7831 debug_print_strings("for_list made from", vals);
7832 for_list = expand_strvec_to_strvec(vals);
7833 for_lcur = for_list;
7834 debug_print_strings("for_list", for_list);
7837 /* "for" loop is over, clean up */
7843 /* Insert next value from for_lcur */
7844 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7845 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7848 if (rword == RES_IN) {
7849 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7851 if (rword == RES_DONE) {
7852 continue; /* "done" has no cmds too */
7855 #if ENABLE_HUSH_CASE
7856 if (rword == RES_CASE) {
7857 case_word = expand_strvec_to_string(pi->cmds->argv);
7860 if (rword == RES_MATCH) {
7863 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7865 /* all prev words didn't match, does this one match? */
7866 argv = pi->cmds->argv;
7868 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7869 /* TODO: which FNM_xxx flags to use? */
7870 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7872 if (cond_code == 0) { /* match! we will execute this branch */
7873 free(case_word); /* make future "word)" stop */
7881 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7883 continue; /* not matched yet, skip this pipe */
7886 /* Just pressing <enter> in shell should check for jobs.
7887 * OTOH, in non-interactive shell this is useless
7888 * and only leads to extra job checks */
7889 if (pi->num_cmds == 0) {
7890 if (G_interactive_fd)
7891 goto check_jobs_and_continue;
7895 /* After analyzing all keywords and conditions, we decided
7896 * to execute this pipe. NB: have to do checkjobs(NULL)
7897 * after run_pipe to collect any background children,
7898 * even if list execution is to be stopped. */
7899 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7902 #if ENABLE_HUSH_LOOPS
7903 G.flag_break_continue = 0;
7905 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7907 /* We ran a builtin, function, or group.
7908 * rcode is already known
7909 * and we don't need to wait for anything. */
7910 G.last_exitcode = rcode;
7911 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7912 check_and_run_traps();
7913 #if ENABLE_HUSH_LOOPS
7914 /* Was it "break" or "continue"? */
7915 if (G.flag_break_continue) {
7916 smallint fbc = G.flag_break_continue;
7917 /* We might fall into outer *loop*,
7918 * don't want to break it too */
7920 G.depth_break_continue--;
7921 if (G.depth_break_continue == 0)
7922 G.flag_break_continue = 0;
7923 /* else: e.g. "continue 2" should *break* once, *then* continue */
7924 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7925 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7926 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7929 /* "continue": simulate end of loop */
7934 if (G_flag_return_in_progress == 1) {
7935 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7938 } else if (pi->followup == PIPE_BG) {
7939 /* What does bash do with attempts to background builtins? */
7940 /* even bash 3.2 doesn't do that well with nested bg:
7941 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7942 * I'm NOT treating inner &'s as jobs */
7943 check_and_run_traps();
7945 if (G.run_list_level == 1)
7948 /* Last command's pid goes to $! */
7949 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7950 G.last_exitcode = rcode = EXIT_SUCCESS;
7951 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7954 if (G.run_list_level == 1 && G_interactive_fd) {
7955 /* Waits for completion, then fg's main shell */
7956 rcode = checkjobs_and_fg_shell(pi);
7957 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7958 check_and_run_traps();
7961 { /* This one just waits for completion */
7962 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
7963 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7964 check_and_run_traps();
7966 G.last_exitcode = rcode;
7970 /* Analyze how result affects subsequent commands */
7972 if (rword == RES_IF || rword == RES_ELIF)
7975 check_jobs_and_continue:
7976 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7977 dont_check_jobs_but_continue: ;
7978 #if ENABLE_HUSH_LOOPS
7979 /* Beware of "while false; true; do ..."! */
7981 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
7982 /* check for RES_DONE is needed for "while ...; do \n done" case */
7984 if (rword == RES_WHILE) {
7986 /* "while false; do...done" - exitcode 0 */
7987 G.last_exitcode = rcode = EXIT_SUCCESS;
7988 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7992 if (rword == RES_UNTIL) {
7994 debug_printf_exec(": until expr is true: breaking\n");
8005 #if ENABLE_HUSH_LOOPS
8010 #if ENABLE_HUSH_CASE
8014 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8018 /* Select which version we will use */
8019 static int run_and_free_list(struct pipe *pi)
8022 debug_printf_exec("run_and_free_list entered\n");
8023 if (!G.o_opt[OPT_O_NOEXEC]) {
8024 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8025 rcode = run_list(pi);
8027 /* free_pipe_list has the side effect of clearing memory.
8028 * In the long run that function can be merged with run_list,
8029 * but doing that now would hobble the debugging effort. */
8031 debug_printf_exec("run_and_free_list return %d\n", rcode);
8036 static void install_sighandlers(unsigned mask)
8038 sighandler_t old_handler;
8040 while ((mask >>= 1) != 0) {
8044 old_handler = install_sighandler(sig, pick_sighandler(sig));
8045 /* POSIX allows shell to re-enable SIGCHLD
8046 * even if it was SIG_IGN on entry.
8047 * Therefore we skip IGN check for it:
8051 if (old_handler == SIG_IGN) {
8052 /* oops... restore back to IGN, and record this fact */
8053 install_sighandler(sig, old_handler);
8055 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8057 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8062 /* Called a few times only (or even once if "sh -c") */
8063 static void install_special_sighandlers(void)
8067 /* Which signals are shell-special? */
8068 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8069 if (G_interactive_fd) {
8070 mask |= SPECIAL_INTERACTIVE_SIGS;
8071 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8072 mask |= SPECIAL_JOBSTOP_SIGS;
8074 /* Careful, do not re-install handlers we already installed */
8075 if (G.special_sig_mask != mask) {
8076 unsigned diff = mask & ~G.special_sig_mask;
8077 G.special_sig_mask = mask;
8078 install_sighandlers(diff);
8084 /* Set handlers to restore tty pgrp and exit */
8085 static void install_fatal_sighandlers(void)
8089 /* We will restore tty pgrp on these signals */
8091 + (1 << SIGILL ) * HUSH_DEBUG
8092 + (1 << SIGFPE ) * HUSH_DEBUG
8093 + (1 << SIGBUS ) * HUSH_DEBUG
8094 + (1 << SIGSEGV) * HUSH_DEBUG
8095 + (1 << SIGTRAP) * HUSH_DEBUG
8097 /* bash 3.2 seems to handle these just like 'fatal' ones */
8100 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8101 * if we aren't interactive... but in this case
8102 * we never want to restore pgrp on exit, and this fn is not called
8104 /*+ (1 << SIGHUP )*/
8105 /*+ (1 << SIGTERM)*/
8106 /*+ (1 << SIGINT )*/
8108 G_fatal_sig_mask = mask;
8110 install_sighandlers(mask);
8114 static int set_mode(int state, char mode, const char *o_opt)
8119 G.o_opt[OPT_O_NOEXEC] = state;
8122 IF_HUSH_MODE_X(G_x_mode = state;)
8126 /* "set -+o" without parameter.
8127 * in bash, set -o produces this output:
8131 * We always use the second form.
8133 const char *p = o_opt_strings;
8136 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8142 idx = index_in_strings(o_opt_strings, o_opt);
8144 G.o_opt[idx] = state;
8148 return EXIT_FAILURE;
8150 return EXIT_SUCCESS;
8153 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8154 int hush_main(int argc, char **argv)
8157 OPT_login = (1 << 0),
8161 unsigned builtin_argc;
8163 struct variable *cur_var;
8164 struct variable *shell_ver;
8167 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8168 G.last_exitcode = EXIT_SUCCESS;
8170 #if ENABLE_HUSH_FAST
8171 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8174 G.argv0_for_re_execing = argv[0];
8176 /* Deal with HUSH_VERSION */
8177 shell_ver = xzalloc(sizeof(*shell_ver));
8178 shell_ver->flg_export = 1;
8179 shell_ver->flg_read_only = 1;
8180 /* Code which handles ${var<op>...} needs writable values for all variables,
8181 * therefore we xstrdup: */
8182 shell_ver->varstr = xstrdup(hush_version_str);
8183 /* Create shell local variables from the values
8184 * currently living in the environment */
8185 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8186 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8187 G.top_var = shell_ver;
8188 cur_var = G.top_var;
8191 char *value = strchr(*e, '=');
8192 if (value) { /* paranoia */
8193 cur_var->next = xzalloc(sizeof(*cur_var));
8194 cur_var = cur_var->next;
8195 cur_var->varstr = *e;
8196 cur_var->max_len = strlen(*e);
8197 cur_var->flg_export = 1;
8201 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8202 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8203 putenv(shell_ver->varstr);
8206 set_pwd_var(/*exp:*/ 1);
8208 #if ENABLE_HUSH_BASH_COMPAT
8209 /* Set (but not export) HOSTNAME unless already set */
8210 if (!get_local_var_value("HOSTNAME")) {
8213 set_local_var_from_halves("HOSTNAME", uts.nodename);
8215 /* bash also exports SHLVL and _,
8216 * and sets (but doesn't export) the following variables:
8218 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8219 * BASH_VERSION='3.2.0(1)-release'
8221 * MACHTYPE=i386-pc-linux-gnu
8223 * PPID=<NNNNN> - we also do it elsewhere
8234 * PIPESTATUS=([0]="0")
8235 * HISTFILE=/<xxx>/.bash_history
8239 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8241 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8252 #if ENABLE_FEATURE_EDITING
8253 G.line_input_state = new_line_input_t(FOR_SHELL);
8256 /* Initialize some more globals to non-zero values */
8257 cmdedit_update_prompt();
8259 die_func = restore_ttypgrp_and__exit;
8261 /* Shell is non-interactive at first. We need to call
8262 * install_special_sighandlers() if we are going to execute "sh <script>",
8263 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8264 * If we later decide that we are interactive, we run install_special_sighandlers()
8265 * in order to intercept (more) signals.
8269 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8270 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8273 opt = getopt(argc, argv, "+c:xinsl"
8276 # if ENABLE_HUSH_FUNCTIONS
8286 * sh ... -c 'script'
8287 * sh ... -c 'script' ARG0 [ARG1...]
8288 * On NOMMU, if builtin_argc != 0,
8289 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8290 * "" needs to be replaced with NULL
8291 * and BARGV vector fed to builtin function.
8292 * Note: the form without ARG0 never happens:
8293 * sh ... -c 'builtin' BARGV... ""
8296 G.root_pid = getpid();
8297 G.root_ppid = getppid();
8299 G.global_argv = argv + optind;
8300 G.global_argc = argc - optind;
8302 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8303 const struct built_in_command *x;
8305 install_special_sighandlers();
8306 x = find_builtin(optarg);
8307 if (x) { /* paranoia */
8308 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8309 G.global_argv += builtin_argc;
8310 G.global_argv[-1] = NULL; /* replace "" */
8312 G.last_exitcode = x->b_function(argv + optind - 1);
8316 if (!G.global_argv[0]) {
8317 /* -c 'script' (no params): prevent empty $0 */
8318 G.global_argv--; /* points to argv[i] of 'script' */
8319 G.global_argv[0] = argv[0];
8321 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8322 install_special_sighandlers();
8323 parse_and_run_string(optarg);
8326 /* Well, we cannot just declare interactiveness,
8327 * we have to have some stuff (ctty, etc) */
8328 /* G_interactive_fd++; */
8331 /* "-s" means "read from stdin", but this is how we always
8332 * operate, so simply do nothing here. */
8338 case '<': /* "big heredoc" support */
8339 full_write1_str(optarg);
8342 unsigned long long empty_trap_mask;
8344 G.root_pid = bb_strtou(optarg, &optarg, 16);
8346 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8348 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8350 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8352 builtin_argc = bb_strtou(optarg, &optarg, 16);
8354 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8355 if (empty_trap_mask != 0) {
8357 install_special_sighandlers();
8358 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8359 for (sig = 1; sig < NSIG; sig++) {
8360 if (empty_trap_mask & (1LL << sig)) {
8361 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8362 install_sighandler(sig, SIG_IGN);
8366 # if ENABLE_HUSH_LOOPS
8368 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8374 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8376 # if ENABLE_HUSH_FUNCTIONS
8378 struct function *funcp = new_function(optarg);
8379 /* funcp->name is already set to optarg */
8380 /* funcp->body is set to NULL. It's a special case. */
8381 funcp->body_as_string = argv[optind];
8389 if (set_mode(1, opt, NULL) == 0) /* no error */
8393 fprintf(stderr, "Usage: sh [FILE]...\n"
8394 " or: sh -c command [args]...\n\n");
8400 } /* option parsing loop */
8402 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8403 G.global_argc = argc - (optind - 1);
8404 G.global_argv = argv + (optind - 1);
8405 G.global_argv[0] = argv[0];
8408 G.root_pid = getpid();
8409 G.root_ppid = getppid();
8412 /* If we are login shell... */
8413 if (flags & OPT_login) {
8415 debug_printf("sourcing /etc/profile\n");
8416 input = fopen_for_read("/etc/profile");
8417 if (input != NULL) {
8418 remember_FILE(input);
8419 install_special_sighandlers();
8420 parse_and_run_file(input);
8421 fclose_and_forget(input);
8423 /* bash: after sourcing /etc/profile,
8424 * tries to source (in the given order):
8425 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8426 * stopping on first found. --noprofile turns this off.
8427 * bash also sources ~/.bash_logout on exit.
8428 * If called as sh, skips .bash_XXX files.
8432 if (G.global_argv[1]) {
8435 * "bash <script>" (which is never interactive (unless -i?))
8436 * sources $BASH_ENV here (without scanning $PATH).
8437 * If called as sh, does the same but with $ENV.
8438 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8442 debug_printf("running script '%s'\n", G.global_argv[0]);
8443 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8444 input = xfopen_for_read(G.global_argv[0]);
8445 xfunc_error_retval = 1;
8446 remember_FILE(input);
8447 install_special_sighandlers();
8448 parse_and_run_file(input);
8449 #if ENABLE_FEATURE_CLEAN_UP
8450 fclose_and_forget(input);
8455 /* Up to here, shell was non-interactive. Now it may become one.
8456 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8459 /* A shell is interactive if the '-i' flag was given,
8460 * or if all of the following conditions are met:
8462 * no arguments remaining or the -s flag given
8463 * standard input is a terminal
8464 * standard output is a terminal
8465 * Refer to Posix.2, the description of the 'sh' utility.
8468 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8469 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8470 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8471 if (G_saved_tty_pgrp < 0)
8472 G_saved_tty_pgrp = 0;
8474 /* try to dup stdin to high fd#, >= 255 */
8475 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8476 if (G_interactive_fd < 0) {
8477 /* try to dup to any fd */
8478 G_interactive_fd = dup(STDIN_FILENO);
8479 if (G_interactive_fd < 0) {
8481 G_interactive_fd = 0;
8482 G_saved_tty_pgrp = 0;
8485 // TODO: track & disallow any attempts of user
8486 // to (inadvertently) close/redirect G_interactive_fd
8488 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8489 if (G_interactive_fd) {
8490 close_on_exec_on(G_interactive_fd);
8492 if (G_saved_tty_pgrp) {
8493 /* If we were run as 'hush &', sleep until we are
8494 * in the foreground (tty pgrp == our pgrp).
8495 * If we get started under a job aware app (like bash),
8496 * make sure we are now in charge so we don't fight over
8497 * who gets the foreground */
8499 pid_t shell_pgrp = getpgrp();
8500 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8501 if (G_saved_tty_pgrp == shell_pgrp)
8503 /* send TTIN to ourself (should stop us) */
8504 kill(- shell_pgrp, SIGTTIN);
8508 /* Install more signal handlers */
8509 install_special_sighandlers();
8511 if (G_saved_tty_pgrp) {
8512 /* Set other signals to restore saved_tty_pgrp */
8513 install_fatal_sighandlers();
8514 /* Put ourselves in our own process group
8515 * (bash, too, does this only if ctty is available) */
8516 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8517 /* Grab control of the terminal */
8518 tcsetpgrp(G_interactive_fd, getpid());
8520 enable_restore_tty_pgrp_on_exit();
8522 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8524 const char *hp = get_local_var_value("HISTFILE");
8526 hp = get_local_var_value("HOME");
8528 hp = concat_path_file(hp, ".hush_history");
8533 G.line_input_state->hist_file = hp;
8534 //set_local_var(xasprintf("HISTFILE=%s", ...));
8536 # if ENABLE_FEATURE_SH_HISTFILESIZE
8537 hp = get_local_var_value("HISTFILESIZE");
8538 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8543 install_special_sighandlers();
8545 #elif ENABLE_HUSH_INTERACTIVE
8546 /* No job control compiled in, only prompt/line editing */
8547 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8548 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8549 if (G_interactive_fd < 0) {
8550 /* try to dup to any fd */
8551 G_interactive_fd = dup(STDIN_FILENO);
8552 if (G_interactive_fd < 0)
8554 G_interactive_fd = 0;
8557 if (G_interactive_fd) {
8558 close_on_exec_on(G_interactive_fd);
8560 install_special_sighandlers();
8562 /* We have interactiveness code disabled */
8563 install_special_sighandlers();
8566 * if interactive but not a login shell, sources ~/.bashrc
8567 * (--norc turns this off, --rcfile <file> overrides)
8570 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8571 /* note: ash and hush share this string */
8572 printf("\n\n%s %s\n"
8573 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8576 "hush - the humble shell"
8580 parse_and_run_file(stdin);
8583 hush_exit(G.last_exitcode);
8588 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8589 int msh_main(int argc, char **argv)
8591 bb_error_msg("msh is deprecated, please use hush instead");
8592 return hush_main(argc, argv);
8600 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8605 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8612 return applet_main_func(argc, argv - argc);
8615 static int FAST_FUNC builtin_test(char **argv)
8617 return run_applet_main(argv, test_main);
8620 static int FAST_FUNC builtin_echo(char **argv)
8622 return run_applet_main(argv, echo_main);
8626 static int FAST_FUNC builtin_printf(char **argv)
8628 return run_applet_main(argv, printf_main);
8632 static char **skip_dash_dash(char **argv)
8635 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8640 static int FAST_FUNC builtin_eval(char **argv)
8642 int rcode = EXIT_SUCCESS;
8644 argv = skip_dash_dash(argv);
8646 char *str = expand_strvec_to_string(argv);
8648 * eval "echo Hi; done" ("done" is syntax error):
8649 * "echo Hi" will not execute too.
8651 parse_and_run_string(str);
8653 rcode = G.last_exitcode;
8658 static int FAST_FUNC builtin_cd(char **argv)
8662 argv = skip_dash_dash(argv);
8664 if (newdir == NULL) {
8665 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8666 * bash says "bash: cd: HOME not set" and does nothing
8669 const char *home = get_local_var_value("HOME");
8670 newdir = home ? home : "/";
8672 if (chdir(newdir)) {
8673 /* Mimic bash message exactly */
8674 bb_perror_msg("cd: %s", newdir);
8675 return EXIT_FAILURE;
8677 /* Read current dir (get_cwd(1) is inside) and set PWD.
8678 * Note: do not enforce exporting. If PWD was unset or unexported,
8679 * set it again, but do not export. bash does the same.
8681 set_pwd_var(/*exp:*/ 0);
8682 return EXIT_SUCCESS;
8685 static int FAST_FUNC builtin_exec(char **argv)
8687 argv = skip_dash_dash(argv);
8688 if (argv[0] == NULL)
8689 return EXIT_SUCCESS; /* bash does this */
8691 /* Careful: we can end up here after [v]fork. Do not restore
8692 * tty pgrp then, only top-level shell process does that */
8693 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8694 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8696 /* TODO: if exec fails, bash does NOT exit! We do.
8697 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8698 * and tcsetpgrp, and this is inherently racy.
8700 execvp_or_die(argv);
8703 static int FAST_FUNC builtin_exit(char **argv)
8705 debug_printf_exec("%s()\n", __func__);
8707 /* interactive bash:
8708 * # trap "echo EEE" EXIT
8711 * There are stopped jobs.
8712 * (if there are _stopped_ jobs, running ones don't count)
8715 * EEE (then bash exits)
8717 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8720 /* note: EXIT trap is run by hush_exit */
8721 argv = skip_dash_dash(argv);
8722 if (argv[0] == NULL)
8723 hush_exit(G.last_exitcode);
8724 /* mimic bash: exit 123abc == exit 255 + error msg */
8725 xfunc_error_retval = 255;
8726 /* bash: exit -2 == exit 254, no error msg */
8727 hush_exit(xatoi(argv[0]) & 0xff);
8730 static void print_escaped(const char *s)
8735 const char *p = strchrnul(s, '\'');
8736 /* print 'xxxx', possibly just '' */
8737 printf("'%.*s'", (int)(p - s), s);
8742 /* s points to '; print "'''...'''" */
8744 do putchar('\''); while (*++s == '\'');
8749 #if !ENABLE_HUSH_LOCAL
8750 #define helper_export_local(argv, exp, lvl) \
8751 helper_export_local(argv, exp)
8753 static void helper_export_local(char **argv, int exp, int lvl)
8757 char *name_end = strchrnul(name, '=');
8759 /* So far we do not check that name is valid (TODO?) */
8761 if (*name_end == '\0') {
8762 struct variable *var, **vpp;
8764 vpp = get_ptr_to_local_var(name, name_end - name);
8765 var = vpp ? *vpp : NULL;
8767 if (exp == -1) { /* unexporting? */
8768 /* export -n NAME (without =VALUE) */
8770 var->flg_export = 0;
8771 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8773 } /* else: export -n NOT_EXISTING_VAR: no-op */
8776 if (exp == 1) { /* exporting? */
8777 /* export NAME (without =VALUE) */
8779 var->flg_export = 1;
8780 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8781 putenv(var->varstr);
8785 #if ENABLE_HUSH_LOCAL
8786 if (exp == 0 /* local? */
8787 && var && var->func_nest_level == lvl
8789 /* "local x=abc; ...; local x" - ignore second local decl */
8793 /* Exporting non-existing variable.
8794 * bash does not put it in environment,
8795 * but remembers that it is exported,
8796 * and does put it in env when it is set later.
8797 * We just set it to "" and export. */
8798 /* Or, it's "local NAME" (without =VALUE).
8799 * bash sets the value to "". */
8800 name = xasprintf("%s=", name);
8802 /* (Un)exporting/making local NAME=VALUE */
8803 name = xstrdup(name);
8805 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8809 static int FAST_FUNC builtin_export(char **argv)
8811 unsigned opt_unexport;
8813 #if ENABLE_HUSH_EXPORT_N
8814 /* "!": do not abort on errors */
8815 opt_unexport = getopt32(argv, "!n");
8816 if (opt_unexport == (uint32_t)-1)
8817 return EXIT_FAILURE;
8824 if (argv[0] == NULL) {
8831 /* ash emits: export VAR='VAL'
8832 * bash: declare -x VAR="VAL"
8833 * we follow ash example */
8834 const char *s = *e++;
8835 const char *p = strchr(s, '=');
8837 if (!p) /* wtf? take next variable */
8840 printf("export %.*s", (int)(p - s) + 1, s);
8841 print_escaped(p + 1);
8845 /*fflush_all(); - done after each builtin anyway */
8847 return EXIT_SUCCESS;
8850 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8852 return EXIT_SUCCESS;
8855 #if ENABLE_HUSH_LOCAL
8856 static int FAST_FUNC builtin_local(char **argv)
8858 if (G.func_nest_level == 0) {
8859 bb_error_msg("%s: not in a function", argv[0]);
8860 return EXIT_FAILURE; /* bash compat */
8862 helper_export_local(argv, 0, G.func_nest_level);
8863 return EXIT_SUCCESS;
8867 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8868 static int FAST_FUNC builtin_unset(char **argv)
8873 /* "!": do not abort on errors */
8874 /* "+": stop at 1st non-option */
8875 opts = getopt32(argv, "!+vf");
8876 if (opts == (unsigned)-1)
8877 return EXIT_FAILURE;
8879 bb_error_msg("unset: -v and -f are exclusive");
8880 return EXIT_FAILURE;
8886 if (!(opts & 2)) { /* not -f */
8887 if (unset_local_var(*argv)) {
8888 /* unset <nonexistent_var> doesn't fail.
8889 * Error is when one tries to unset RO var.
8890 * Message was printed by unset_local_var. */
8894 #if ENABLE_HUSH_FUNCTIONS
8904 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8905 * built-in 'set' handler
8907 * set [-abCefhmnuvx] [-o option] [argument...]
8908 * set [+abCefhmnuvx] [+o option] [argument...]
8909 * set -- [argument...]
8912 * Implementations shall support the options in both their hyphen and
8913 * plus-sign forms. These options can also be specified as options to sh.
8915 * Write out all variables and their values: set
8916 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8917 * Turn on the -x and -v options: set -xv
8918 * Unset all positional parameters: set --
8919 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8920 * Set the positional parameters to the expansion of x, even if x expands
8921 * with a leading '-' or '+': set -- $x
8923 * So far, we only support "set -- [argument...]" and some of the short names.
8925 static int FAST_FUNC builtin_set(char **argv)
8928 char **pp, **g_argv;
8929 char *arg = *++argv;
8933 for (e = G.top_var; e; e = e->next)
8935 return EXIT_SUCCESS;
8939 if (strcmp(arg, "--") == 0) {
8943 if (arg[0] != '+' && arg[0] != '-')
8945 for (n = 1; arg[n]; ++n) {
8946 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8948 if (arg[n] == 'o' && argv[1])
8951 } while ((arg = *++argv) != NULL);
8952 /* Now argv[0] is 1st argument */
8955 return EXIT_SUCCESS;
8958 /* NB: G.global_argv[0] ($0) is never freed/changed */
8959 g_argv = G.global_argv;
8960 if (G.global_args_malloced) {
8966 G.global_args_malloced = 1;
8967 pp = xzalloc(sizeof(pp[0]) * 2);
8968 pp[0] = g_argv[0]; /* retain $0 */
8971 /* This realloc's G.global_argv */
8972 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8979 return EXIT_SUCCESS;
8981 /* Nothing known, so abort */
8983 bb_error_msg("set: %s: invalid option", arg);
8984 return EXIT_FAILURE;
8987 static int FAST_FUNC builtin_shift(char **argv)
8990 argv = skip_dash_dash(argv);
8994 if (n >= 0 && n < G.global_argc) {
8995 if (G.global_args_malloced) {
8998 free(G.global_argv[m++]);
9001 memmove(&G.global_argv[1], &G.global_argv[n+1],
9002 G.global_argc * sizeof(G.global_argv[0]));
9003 return EXIT_SUCCESS;
9005 return EXIT_FAILURE;
9008 /* Interruptibility of read builtin in bash
9009 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9011 * Empty trap makes read ignore corresponding signal, for any signal.
9014 * - terminates non-interactive shell;
9015 * - interrupts read in interactive shell;
9016 * if it has non-empty trap:
9017 * - executes trap and returns to command prompt in interactive shell;
9018 * - executes trap and returns to read in non-interactive shell;
9020 * - is ignored (does not interrupt) read in interactive shell;
9021 * - terminates non-interactive shell;
9022 * if it has non-empty trap:
9023 * - executes trap and returns to read;
9025 * - terminates shell (regardless of interactivity);
9026 * if it has non-empty trap:
9027 * - executes trap and returns to read;
9029 static int FAST_FUNC builtin_read(char **argv)
9039 /* "!": do not abort on errors.
9040 * Option string must start with "sr" to match BUILTIN_READ_xxx
9042 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9043 if (read_flags == (uint32_t)-1)
9044 return EXIT_FAILURE;
9046 ifs = get_local_var_value("IFS"); /* can be NULL */
9049 r = shell_builtin_read(set_local_var_from_halves,
9059 if ((uintptr_t)r == 1 && errno == EINTR) {
9060 unsigned sig = check_and_run_traps();
9061 if (sig && sig != SIGINT)
9065 if ((uintptr_t)r > 1) {
9066 bb_error_msg("%s", r);
9067 r = (char*)(uintptr_t)1;
9070 return (uintptr_t)r;
9073 static int FAST_FUNC builtin_trap(char **argv)
9079 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
9084 /* No args: print all trapped */
9085 for (i = 0; i < NSIG; ++i) {
9088 print_escaped(G.traps[i]);
9089 /* note: bash adds "SIG", but only if invoked
9090 * as "bash". If called as "sh", or if set -o posix,
9091 * then it prints short signal names.
9092 * We are printing short names: */
9093 printf(" %s\n", get_signame(i));
9096 /*fflush_all(); - done after each builtin anyway */
9097 return EXIT_SUCCESS;
9101 /* If first arg is a number: reset all specified signals */
9102 sig = bb_strtou(*argv, NULL, 10);
9108 sighandler_t handler;
9110 sig = get_signum(*argv++);
9111 if (sig < 0 || sig >= NSIG) {
9113 /* Mimic bash message exactly */
9114 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9119 G.traps[sig] = xstrdup(new_cmd);
9121 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9122 get_signame(sig), sig, G.traps[sig]);
9124 /* There is no signal for 0 (EXIT) */
9129 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9131 /* We are removing trap handler */
9132 handler = pick_sighandler(sig);
9133 install_sighandler(sig, handler);
9138 if (!argv[1]) { /* no second arg */
9139 bb_error_msg("trap: invalid arguments");
9140 return EXIT_FAILURE;
9143 /* First arg is "-": reset all specified to default */
9144 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9145 /* Everything else: set arg as signal handler
9146 * (includes "" case, which ignores signal) */
9147 if (argv[0][0] == '-') {
9148 if (argv[0][1] == '\0') { /* "-" */
9149 /* new_cmd remains NULL: "reset these sigs" */
9152 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9155 /* else: "-something", no special meaning */
9160 goto process_sig_list;
9163 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9164 static int FAST_FUNC builtin_type(char **argv)
9166 int ret = EXIT_SUCCESS;
9172 if (0) {} /* make conditional compile easier below */
9173 /*else if (find_alias(*argv))
9174 type = "an alias";*/
9175 #if ENABLE_HUSH_FUNCTIONS
9176 else if (find_function(*argv))
9177 type = "a function";
9179 else if (find_builtin(*argv))
9180 type = "a shell builtin";
9181 else if ((path = find_in_path(*argv)) != NULL)
9184 bb_error_msg("type: %s: not found", *argv);
9189 printf("%s is %s\n", *argv, type);
9197 /* built-in 'fg' and 'bg' handler */
9198 static int FAST_FUNC builtin_fg_bg(char **argv)
9203 if (!G_interactive_fd)
9204 return EXIT_FAILURE;
9206 /* If they gave us no args, assume they want the last backgrounded task */
9208 for (pi = G.job_list; pi; pi = pi->next) {
9209 if (pi->jobid == G.last_jobid) {
9213 bb_error_msg("%s: no current job", argv[0]);
9214 return EXIT_FAILURE;
9216 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
9217 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
9218 return EXIT_FAILURE;
9220 for (pi = G.job_list; pi; pi = pi->next) {
9221 if (pi->jobid == jobnum) {
9225 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
9226 return EXIT_FAILURE;
9228 /* TODO: bash prints a string representation
9229 * of job being foregrounded (like "sleep 1 | cat") */
9230 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9231 /* Put the job into the foreground. */
9232 tcsetpgrp(G_interactive_fd, pi->pgrp);
9235 /* Restart the processes in the job */
9236 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9237 for (i = 0; i < pi->num_cmds; i++) {
9238 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9240 pi->stopped_cmds = 0;
9242 i = kill(- pi->pgrp, SIGCONT);
9244 if (errno == ESRCH) {
9245 delete_finished_bg_job(pi);
9246 return EXIT_SUCCESS;
9248 bb_perror_msg("kill (SIGCONT)");
9251 if (argv[0][0] == 'f') {
9253 return checkjobs_and_fg_shell(pi);
9255 return EXIT_SUCCESS;
9259 #if ENABLE_HUSH_HELP
9260 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9262 const struct built_in_command *x;
9265 "Built-in commands:\n"
9266 "------------------\n");
9267 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9269 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9271 return EXIT_SUCCESS;
9275 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9276 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9278 show_history(G.line_input_state);
9279 return EXIT_SUCCESS;
9284 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9287 const char *status_string;
9289 for (job = G.job_list; job; job = job->next) {
9290 if (job->alive_cmds == job->stopped_cmds)
9291 status_string = "Stopped";
9293 status_string = "Running";
9295 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9297 return EXIT_SUCCESS;
9302 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9307 # ifdef M_TRIM_THRESHOLD
9308 /* Optional. Reduces probability of false positives */
9311 /* Crude attempt to find where "free memory" starts,
9312 * sans fragmentation. */
9314 l = (unsigned long)p;
9317 if (l < (unsigned long)p) l = (unsigned long)p;
9323 struct mallinfo mi = mallinfo();
9324 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9325 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9329 if (!G.memleak_value)
9330 G.memleak_value = l;
9332 l -= G.memleak_value;
9339 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9344 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9347 return EXIT_SUCCESS;
9350 static int FAST_FUNC builtin_source(char **argv)
9352 char *arg_path, *filename;
9355 #if ENABLE_HUSH_FUNCTIONS
9359 argv = skip_dash_dash(argv);
9362 /* bash says: "bash: .: filename argument required" */
9363 return 2; /* bash compat */
9366 if (!strchr(filename, '/')) {
9367 arg_path = find_in_path(filename);
9369 filename = arg_path;
9371 input = remember_FILE(fopen_or_warn(filename, "r"));
9374 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9375 /* POSIX: non-interactive shell should abort here,
9376 * not merely fail. So far no one complained :)
9378 return EXIT_FAILURE;
9381 #if ENABLE_HUSH_FUNCTIONS
9382 sv_flg = G_flag_return_in_progress;
9383 /* "we are inside sourced file, ok to use return" */
9384 G_flag_return_in_progress = -1;
9387 save_and_replace_G_args(&sv, argv);
9389 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9390 G.last_exitcode = 0;
9391 parse_and_run_file(input);
9392 fclose_and_forget(input);
9395 restore_G_args(&sv, argv);
9396 #if ENABLE_HUSH_FUNCTIONS
9397 G_flag_return_in_progress = sv_flg;
9400 return G.last_exitcode;
9403 static int FAST_FUNC builtin_umask(char **argv)
9410 argv = skip_dash_dash(argv);
9412 mode_t old_mask = mask;
9414 /* numeric umasks are taken as-is */
9415 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9416 if (!isdigit(argv[0][0]))
9418 mask = bb_parse_mode(argv[0], mask);
9419 if (!isdigit(argv[0][0]))
9421 if ((unsigned)mask > 0777) {
9424 * bash: umask: 'q': invalid symbolic mode operator
9425 * bash: umask: 999: octal number out of range
9427 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9432 printf("%04o\n", (unsigned) mask);
9433 /* fall through and restore mask which we set to 0 */
9437 return !rc; /* rc != 0 - success */
9440 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9441 static int wait_for_child_or_signal(pid_t waitfor_pid)
9446 sigset_t oldset, allsigs;
9448 /* waitpid is not interruptible by SA_RESTARTed
9449 * signals which we use. Thus, this ugly dance:
9452 /* Make sure possible SIGCHLD is stored in kernel's
9453 * pending signal mask before we call waitpid.
9454 * Or else we may race with SIGCHLD, lose it,
9455 * and get stuck in sigwaitinfo...
9457 sigfillset(&allsigs);
9458 sigprocmask(SIG_SETMASK, &allsigs, &oldset);
9460 if (!sigisemptyset(&G.pending_set)) {
9461 /* Crap! we raced with some signal! */
9466 /*errno = 0; - checkjobs does this */
9467 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9468 /* if ECHILD, there are no children (ret is -1 or 0) */
9469 /* if ret == 0, no children changed state */
9470 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9471 if (errno == ECHILD || ret--) {
9472 if (ret < 0) /* if ECHILD, may need to fix */
9474 sigprocmask(SIG_SETMASK, &oldset, NULL);
9478 /* Wait for SIGCHLD or any other signal */
9479 //sig = sigwaitinfo(&allsigs, NULL);
9480 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9481 /* Note: sigsuspend invokes signal handler */
9482 sigsuspend(&oldset);
9484 sigprocmask(SIG_SETMASK, &oldset, NULL);
9486 /* So, did we get a signal? */
9488 // raise(sig); /* run handler */
9489 sig = check_and_run_traps();
9490 if (sig /*&& sig != SIGCHLD - always true */) {
9495 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9500 static int FAST_FUNC builtin_wait(char **argv)
9505 argv = skip_dash_dash(argv);
9506 if (argv[0] == NULL) {
9507 /* Don't care about wait results */
9508 /* Note 1: must wait until there are no more children */
9509 /* Note 2: must be interruptible */
9511 * $ sleep 3 & sleep 6 & wait
9516 * $ sleep 3 & sleep 6 & wait
9520 * ^C <-- after ~4 sec from keyboard
9523 return wait_for_child_or_signal(0 /*(no pid to wait for)*/);
9526 /* TODO: support "wait %jobspec" */
9528 pid_t pid = bb_strtou(*argv, NULL, 10);
9529 if (errno || pid <= 0) {
9530 /* mimic bash message */
9531 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9533 continue; /* bash checks all argv[] */
9535 /* Do we have such child? */
9536 ret = waitpid(pid, &status, WNOHANG);
9539 if (errno == ECHILD) {
9540 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9541 /* "wait $!" but last bg task has already exited. Try:
9542 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9543 * In bash it prints exitcode 0, then 3.
9545 ret = 0; /* FIXME */
9548 /* Example: "wait 1". mimic bash message */
9549 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9552 bb_perror_msg("wait %s", *argv);
9555 continue; /* bash checks all argv[] */
9558 /* Yes, and it still runs */
9559 ret = wait_for_child_or_signal(pid);
9561 /* Yes, and it just exited */
9562 process_wait_result(NULL, pid, status);
9563 ret = WEXITSTATUS(status);
9564 if (WIFSIGNALED(status))
9565 ret = 128 + WTERMSIG(status);
9572 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9573 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9576 def = bb_strtou(argv[1], NULL, 10);
9577 if (errno || def < def_min || argv[2]) {
9578 bb_error_msg("%s: bad arguments", argv[0]);
9586 #if ENABLE_HUSH_LOOPS
9587 static int FAST_FUNC builtin_break(char **argv)
9590 if (G.depth_of_loop == 0) {
9591 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9592 /* if we came from builtin_continue(), need to undo "= 1" */
9593 G.flag_break_continue = 0;
9594 return EXIT_SUCCESS; /* bash compat */
9596 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9598 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9599 if (depth == UINT_MAX)
9600 G.flag_break_continue = BC_BREAK;
9601 if (G.depth_of_loop < depth)
9602 G.depth_break_continue = G.depth_of_loop;
9604 return EXIT_SUCCESS;
9607 static int FAST_FUNC builtin_continue(char **argv)
9609 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9610 return builtin_break(argv);
9614 #if ENABLE_HUSH_FUNCTIONS
9615 static int FAST_FUNC builtin_return(char **argv)
9619 if (G_flag_return_in_progress != -1) {
9620 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9621 return EXIT_FAILURE; /* bash compat */
9624 G_flag_return_in_progress = 1;
9627 * out of range: wraps around at 256, does not error out
9628 * non-numeric param:
9629 * f() { false; return qwe; }; f; echo $?
9630 * bash: return: qwe: numeric argument required <== we do this
9631 * 255 <== we also do this
9633 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);