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)
47 * follow IFS rules more precisely, including update semantics
48 * builtins mandated by standards we don't support:
49 * [un]alias, command, fc, getopts, newgrp, readonly, times
50 * make complex ${var%...} constructs support optional
51 * make here documents optional
54 * redirection of stdout+stderr: &> and >&
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
69 * In bash, export builtin is special, its arguments are assignments
70 * and therefore expansion of them should be "one-word" expansion:
71 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
73 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
74 * ls: cannot access i=a: No such file or directory
75 * ls: cannot access b: No such file or directory
76 * Note1: same applies to local builtin.
77 * Note2: bash 3.2.33(1) does this only if export word itself
79 * $ export i=`echo 'aaa bbb'`; echo "$i"
81 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
84 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
85 || defined(__APPLE__) \
87 # include <malloc.h> /* for malloc_trim */
90 /* #include <dmalloc.h> */
94 #include <sys/utsname.h> /* for setting $HOSTNAME */
96 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
98 #include "shell_common.h"
101 #if ENABLE_HUSH_RANDOM_SUPPORT
104 # define CLEAR_RANDOM_T(rnd) ((void)0)
106 #ifndef F_DUPFD_CLOEXEC
107 # define F_DUPFD_CLOEXEC F_DUPFD
110 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
114 //config: bool "hush"
117 //config: hush is a small shell (25k). It handles the normal flow control
118 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
119 //config: case/esac. Redirections, here documents, $((arithmetic))
120 //config: and functions are supported.
122 //config: It will compile and work on no-mmu systems.
124 //config: It does not handle select, aliases, tilde expansion,
125 //config: &>file and >&file redirection of stdout+stderr.
127 //config:config HUSH_BASH_COMPAT
128 //config: bool "bash-compatible extensions"
130 //config: depends on HUSH
132 //config: Enable bash-compatible extensions.
134 //config:config HUSH_BRACE_EXPANSION
135 //config: bool "Brace expansion"
137 //config: depends on HUSH_BASH_COMPAT
139 //config: Enable {abc,def} extension.
141 //config:config HUSH_HELP
142 //config: bool "help builtin"
144 //config: depends on HUSH
146 //config: Enable help builtin in hush. Code size + ~1 kbyte.
148 //config:config HUSH_INTERACTIVE
149 //config: bool "Interactive mode"
151 //config: depends on HUSH
153 //config: Enable interactive mode (prompt and command editing).
154 //config: Without this, hush simply reads and executes commands
155 //config: from stdin just like a shell script from a file.
156 //config: No prompt, no PS1/PS2 magic shell variables.
158 //config:config HUSH_SAVEHISTORY
159 //config: bool "Save command history to .hush_history"
161 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
163 //config: Enable history saving in hush.
165 //config:config HUSH_JOB
166 //config: bool "Job control"
168 //config: depends on HUSH_INTERACTIVE
170 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
171 //config: command (not entire shell), fg/bg builtins work. Without this option,
172 //config: "cmd &" still works by simply spawning a process and immediately
173 //config: prompting for next command (or executing next command in a script),
174 //config: but no separate process group is formed.
176 //config:config HUSH_TICK
177 //config: bool "Process substitution"
179 //config: depends on HUSH
181 //config: Enable process substitution `command` and $(command) in hush.
183 //config:config HUSH_IF
184 //config: bool "Support if/then/elif/else/fi"
186 //config: depends on HUSH
188 //config: Enable if/then/elif/else/fi in hush.
190 //config:config HUSH_LOOPS
191 //config: bool "Support for, while and until loops"
193 //config: depends on HUSH
195 //config: Enable for, while and until loops in hush.
197 //config:config HUSH_CASE
198 //config: bool "Support case ... esac statement"
200 //config: depends on HUSH
202 //config: Enable case ... esac statement in hush. +400 bytes.
204 //config:config HUSH_FUNCTIONS
205 //config: bool "Support funcname() { commands; } syntax"
207 //config: depends on HUSH
209 //config: Enable support for shell functions in hush. +800 bytes.
211 //config:config HUSH_LOCAL
212 //config: bool "Support local builtin"
214 //config: depends on HUSH_FUNCTIONS
216 //config: Enable support for local variables in functions.
218 //config:config HUSH_RANDOM_SUPPORT
219 //config: bool "Pseudorandom generator and $RANDOM variable"
221 //config: depends on HUSH
223 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
224 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
226 //config:config HUSH_EXPORT_N
227 //config: bool "Support 'export -n' option"
229 //config: depends on HUSH
231 //config: export -n unexports variables. It is a bash extension.
233 //config:config HUSH_MODE_X
234 //config: bool "Support 'hush -x' option and 'set -x' command"
236 //config: depends on HUSH
238 //config: This instructs hush to print commands before execution.
239 //config: Adds ~300 bytes.
242 //config: bool "msh (deprecated: aliased to hush)"
244 //config: select HUSH
246 //config: msh is deprecated and will be removed, please migrate to hush.
249 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
250 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
251 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
252 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
254 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
255 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
257 /* -i (interactive) and -s (read stdin) are also accepted,
258 * but currently do nothing, therefore aren't shown in help.
259 * NOMMU-specific options are not meant to be used by users,
260 * therefore we don't show them either.
262 //usage:#define hush_trivial_usage
263 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
264 //usage:#define hush_full_usage "\n\n"
265 //usage: "Unix shell interpreter"
267 //usage:#define msh_trivial_usage hush_trivial_usage
268 //usage:#define msh_full_usage hush_full_usage
270 //usage:#if ENABLE_FEATURE_SH_IS_HUSH
271 //usage:# define sh_trivial_usage hush_trivial_usage
272 //usage:# define sh_full_usage hush_full_usage
274 //usage:#if ENABLE_FEATURE_BASH_IS_HUSH
275 //usage:# define bash_trivial_usage hush_trivial_usage
276 //usage:# define bash_full_usage hush_full_usage
281 #define LEAK_HUNTING 0
282 #define BUILD_AS_NOMMU 0
283 /* Enable/disable sanity checks. Ok to enable in production,
284 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
285 * Keeping 1 for now even in released versions.
288 /* Slightly bigger (+200 bytes), but faster hush.
289 * So far it only enables a trick with counting SIGCHLDs and forks,
290 * which allows us to do fewer waitpid's.
291 * (we can detect a case where neither forks were done nor SIGCHLDs happened
292 * and therefore waitpid will return the same result as last time)
294 #define ENABLE_HUSH_FAST 0
295 /* TODO: implement simplified code for users which do not need ${var%...} ops
296 * So far ${var%...} ops are always enabled:
298 #define ENABLE_HUSH_DOLLAR_OPS 1
303 # undef USE_FOR_NOMMU
306 # define USE_FOR_NOMMU(...) __VA_ARGS__
307 # define USE_FOR_MMU(...)
310 #include "NUM_APPLETS.h"
312 /* STANDALONE does not make sense, and won't compile */
313 # undef CONFIG_FEATURE_SH_STANDALONE
314 # undef ENABLE_FEATURE_SH_STANDALONE
315 # undef IF_FEATURE_SH_STANDALONE
316 # undef IF_NOT_FEATURE_SH_STANDALONE
317 # define ENABLE_FEATURE_SH_STANDALONE 0
318 # define IF_FEATURE_SH_STANDALONE(...)
319 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
322 #if !ENABLE_HUSH_INTERACTIVE
323 # undef ENABLE_FEATURE_EDITING
324 # define ENABLE_FEATURE_EDITING 0
325 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
326 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
327 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
328 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
331 /* Do we support ANY keywords? */
332 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
333 # define HAS_KEYWORDS 1
334 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
335 # define IF_HAS_NO_KEYWORDS(...)
337 # define HAS_KEYWORDS 0
338 # define IF_HAS_KEYWORDS(...)
339 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
342 /* If you comment out one of these below, it will be #defined later
343 * to perform debug printfs to stderr: */
344 #define debug_printf(...) do {} while (0)
345 /* Finer-grained debug switches */
346 #define debug_printf_parse(...) do {} while (0)
347 #define debug_print_tree(a, b) do {} while (0)
348 #define debug_printf_exec(...) do {} while (0)
349 #define debug_printf_env(...) do {} while (0)
350 #define debug_printf_jobs(...) do {} while (0)
351 #define debug_printf_expand(...) do {} while (0)
352 #define debug_printf_varexp(...) do {} while (0)
353 #define debug_printf_glob(...) do {} while (0)
354 #define debug_printf_list(...) do {} while (0)
355 #define debug_printf_subst(...) do {} while (0)
356 #define debug_printf_clean(...) do {} while (0)
358 #define ERR_PTR ((void*)(long)1)
360 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
362 #define _SPECIAL_VARS_STR "_*@$!?#"
363 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
364 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
365 #if ENABLE_HUSH_BASH_COMPAT
366 /* Support / and // replace ops */
367 /* Note that // is stored as \ in "encoded" string representation */
368 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
369 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
370 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
372 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
373 # define VAR_SUBST_OPS "%#:-=+?"
374 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
377 #define SPECIAL_VAR_SYMBOL 3
381 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
383 /* This supports saving pointers malloced in vfork child,
384 * to be freed in the parent.
387 typedef struct nommu_save_t {
389 struct variable *old_vars;
391 char **argv_from_re_execing;
404 #if ENABLE_HUSH_LOOPS
411 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
416 /* three pseudo-keywords support contrived "case" syntax: */
417 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
418 RES_MATCH , /* "word)" */
419 RES_CASE_BODY, /* "this command is inside CASE" */
426 typedef struct o_string {
428 int length; /* position where data is appended */
431 /* At least some part of the string was inside '' or "",
432 * possibly empty one: word"", wo''rd etc. */
433 smallint has_quoted_part;
434 smallint has_empty_slot;
435 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
438 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
440 /* Protect newly added chars against globbing
441 * by prepending \ to *, ?, [, \ */
442 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
445 MAYBE_ASSIGNMENT = 0,
446 DEFINITELY_ASSIGNMENT = 1,
448 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
451 /* Used for initialization: o_string foo = NULL_O_STRING; */
452 #define NULL_O_STRING { NULL }
454 #ifndef debug_printf_parse
455 static const char *const assignment_flag[] = {
457 "DEFINITELY_ASSIGNMENT",
463 typedef struct in_str {
465 /* eof_flag=1: last char in ->p is really an EOF */
466 char eof_flag; /* meaningless if ->p == NULL */
468 #if ENABLE_HUSH_INTERACTIVE
469 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;
783 smallint exiting; /* used to prevent EXIT trap recursion */
784 /* These four support $?, $#, and $1 */
785 smalluint last_exitcode;
786 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
787 smalluint global_args_malloced;
788 /* how many non-NULL argv's we have. NB: $# + 1 */
792 char *argv0_for_re_execing;
794 #if ENABLE_HUSH_LOOPS
795 unsigned depth_break_continue;
796 unsigned depth_of_loop;
800 struct variable *top_var;
801 char **expanded_assignments;
802 #if ENABLE_HUSH_FUNCTIONS
803 struct function *top_func;
804 # if ENABLE_HUSH_LOCAL
805 struct variable **shadowed_vars_pp;
806 unsigned func_nest_level;
809 /* Signal and trap handling */
811 unsigned count_SIGCHLD;
812 unsigned handled_SIGCHLD;
813 smallint we_have_children;
815 struct FILE_list *FILE_list;
816 /* Which signals have non-DFL handler (even with no traps set)?
817 * Set at the start to:
818 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
819 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
820 * The rest is cleared right before execv syscalls.
821 * Other than these two times, never modified.
823 unsigned special_sig_mask;
825 unsigned fatal_sig_mask;
826 # define G_fatal_sig_mask G.fatal_sig_mask
828 # define G_fatal_sig_mask 0
830 char **traps; /* char *traps[NSIG] */
831 sigset_t pending_set;
833 unsigned long memleak_value;
837 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
839 #define G (*ptr_to_globals)
840 /* Not #defining name to G.name - this quickly gets unwieldy
841 * (too many defines). Also, I actually prefer to see when a variable
842 * is global, thus "G." prefix is a useful hint */
843 #define INIT_G() do { \
844 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
845 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
846 sigfillset(&G.sa.sa_mask); \
847 G.sa.sa_flags = SA_RESTART; \
851 /* Function prototypes for builtins */
852 static int builtin_cd(char **argv) FAST_FUNC;
853 static int builtin_echo(char **argv) FAST_FUNC;
854 static int builtin_eval(char **argv) FAST_FUNC;
855 static int builtin_exec(char **argv) FAST_FUNC;
856 static int builtin_exit(char **argv) FAST_FUNC;
857 static int builtin_export(char **argv) FAST_FUNC;
859 static int builtin_fg_bg(char **argv) FAST_FUNC;
860 static int builtin_jobs(char **argv) FAST_FUNC;
863 static int builtin_help(char **argv) FAST_FUNC;
865 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
866 static int builtin_history(char **argv) FAST_FUNC;
868 #if ENABLE_HUSH_LOCAL
869 static int builtin_local(char **argv) FAST_FUNC;
872 static int builtin_memleak(char **argv) FAST_FUNC;
875 static int builtin_printf(char **argv) FAST_FUNC;
877 static int builtin_pwd(char **argv) FAST_FUNC;
878 static int builtin_read(char **argv) FAST_FUNC;
879 static int builtin_set(char **argv) FAST_FUNC;
880 static int builtin_shift(char **argv) FAST_FUNC;
881 static int builtin_source(char **argv) FAST_FUNC;
882 static int builtin_test(char **argv) FAST_FUNC;
883 static int builtin_trap(char **argv) FAST_FUNC;
884 static int builtin_type(char **argv) FAST_FUNC;
885 static int builtin_true(char **argv) FAST_FUNC;
886 static int builtin_umask(char **argv) FAST_FUNC;
887 static int builtin_unset(char **argv) FAST_FUNC;
888 static int builtin_wait(char **argv) FAST_FUNC;
889 #if ENABLE_HUSH_LOOPS
890 static int builtin_break(char **argv) FAST_FUNC;
891 static int builtin_continue(char **argv) FAST_FUNC;
893 #if ENABLE_HUSH_FUNCTIONS
894 static int builtin_return(char **argv) FAST_FUNC;
897 /* Table of built-in functions. They can be forked or not, depending on
898 * context: within pipes, they fork. As simple commands, they do not.
899 * When used in non-forking context, they can change global variables
900 * in the parent shell process. If forked, of course they cannot.
901 * For example, 'unset foo | whatever' will parse and run, but foo will
902 * still be set at the end. */
903 struct built_in_command {
905 int (*b_function)(char **argv) FAST_FUNC;
908 # define BLTIN(cmd, func, help) { cmd, func, help }
910 # define BLTIN(cmd, func, help) { cmd, func }
914 static const struct built_in_command bltins1[] = {
915 BLTIN("." , builtin_source , "Run commands in a file"),
916 BLTIN(":" , builtin_true , NULL),
918 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
920 #if ENABLE_HUSH_LOOPS
921 BLTIN("break" , builtin_break , "Exit from a loop"),
923 BLTIN("cd" , builtin_cd , "Change directory"),
924 #if ENABLE_HUSH_LOOPS
925 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
927 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
928 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
929 BLTIN("exit" , builtin_exit , "Exit"),
930 BLTIN("export" , builtin_export , "Set environment variables"),
932 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
935 BLTIN("help" , builtin_help , NULL),
937 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
938 BLTIN("history" , builtin_history , "Show command history"),
941 BLTIN("jobs" , builtin_jobs , "List jobs"),
943 #if ENABLE_HUSH_LOCAL
944 BLTIN("local" , builtin_local , "Set local variables"),
947 BLTIN("memleak" , builtin_memleak , NULL),
949 BLTIN("read" , builtin_read , "Input into variable"),
950 #if ENABLE_HUSH_FUNCTIONS
951 BLTIN("return" , builtin_return , "Return from a function"),
953 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
954 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
955 #if ENABLE_HUSH_BASH_COMPAT
956 BLTIN("source" , builtin_source , "Run commands in a file"),
958 BLTIN("trap" , builtin_trap , "Trap signals"),
959 BLTIN("true" , builtin_true , NULL),
960 BLTIN("type" , builtin_type , "Show command type"),
961 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
962 BLTIN("umask" , builtin_umask , "Set file creation mask"),
963 BLTIN("unset" , builtin_unset , "Unset variables"),
964 BLTIN("wait" , builtin_wait , "Wait for process"),
966 /* For now, echo and test are unconditionally enabled.
967 * Maybe make it configurable? */
968 static const struct built_in_command bltins2[] = {
969 BLTIN("[" , builtin_test , NULL),
970 BLTIN("echo" , builtin_echo , NULL),
972 BLTIN("printf" , builtin_printf , NULL),
974 BLTIN("pwd" , builtin_pwd , NULL),
975 BLTIN("test" , builtin_test , NULL),
982 /* prevent disasters with G.debug_indent < 0 */
983 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
984 # define debug_enter() (G.debug_indent++)
985 # define debug_leave() (G.debug_indent--)
987 # define indent() ((void)0)
988 # define debug_enter() ((void)0)
989 # define debug_leave() ((void)0)
993 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
996 #ifndef debug_printf_parse
997 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1000 #ifndef debug_printf_exec
1001 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1004 #ifndef debug_printf_env
1005 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1008 #ifndef debug_printf_jobs
1009 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1010 # define DEBUG_JOBS 1
1012 # define DEBUG_JOBS 0
1015 #ifndef debug_printf_expand
1016 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1017 # define DEBUG_EXPAND 1
1019 # define DEBUG_EXPAND 0
1022 #ifndef debug_printf_varexp
1023 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1026 #ifndef debug_printf_glob
1027 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1028 # define DEBUG_GLOB 1
1030 # define DEBUG_GLOB 0
1033 #ifndef debug_printf_list
1034 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1037 #ifndef debug_printf_subst
1038 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1041 #ifndef debug_printf_clean
1042 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1043 # define DEBUG_CLEAN 1
1045 # define DEBUG_CLEAN 0
1049 static void debug_print_strings(const char *prefix, char **vv)
1052 fdprintf(2, "%s:\n", prefix);
1054 fdprintf(2, " '%s'\n", *vv++);
1057 # define debug_print_strings(prefix, vv) ((void)0)
1061 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1064 static void *xxmalloc(int lineno, size_t size)
1066 void *ptr = xmalloc((size + 0xff) & ~0xff);
1067 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1070 static void *xxrealloc(int lineno, void *ptr, size_t size)
1072 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1073 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1076 static char *xxstrdup(int lineno, const char *str)
1078 char *ptr = xstrdup(str);
1079 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1082 static void xxfree(void *ptr)
1084 fdprintf(2, "free %p\n", ptr);
1087 # define xmalloc(s) xxmalloc(__LINE__, s)
1088 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1089 # define xstrdup(s) xxstrdup(__LINE__, s)
1090 # define free(p) xxfree(p)
1094 /* Syntax and runtime errors. They always abort scripts.
1095 * In interactive use they usually discard unparsed and/or unexecuted commands
1096 * and return to the prompt.
1097 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1100 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1101 # define syntax_error(lineno, msg) syntax_error(msg)
1102 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1103 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1104 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1105 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1108 static void die_if_script(unsigned lineno, const char *fmt, ...)
1113 bb_error_msg("hush.c:%u", lineno);
1116 bb_verror_msg(fmt, p, NULL);
1118 if (!G_interactive_fd)
1122 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1125 bb_error_msg("syntax error: %s", msg);
1127 bb_error_msg("syntax error");
1130 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1132 bb_error_msg("syntax error at '%s'", msg);
1135 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1137 bb_error_msg("syntax error: unterminated %s", s);
1140 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1142 char msg[2] = { ch, '\0' };
1143 syntax_error_unterm_str(lineno, msg);
1146 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1151 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1155 # undef die_if_script
1156 # undef syntax_error
1157 # undef syntax_error_at
1158 # undef syntax_error_unterm_ch
1159 # undef syntax_error_unterm_str
1160 # undef syntax_error_unexpected_ch
1162 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1163 # define syntax_error(msg) syntax_error(__LINE__, msg)
1164 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1165 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1166 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1167 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1171 #if ENABLE_HUSH_INTERACTIVE
1172 static void cmdedit_update_prompt(void);
1174 # define cmdedit_update_prompt() ((void)0)
1178 /* Utility functions
1180 /* Replace each \x with x in place, return ptr past NUL. */
1181 static char *unbackslash(char *src)
1183 char *dst = src = strchrnul(src, '\\');
1187 if ((*dst++ = *src++) == '\0')
1193 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1214 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1215 v[count1 + count2] = NULL;
1218 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1222 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1224 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1225 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1228 #define add_strings_to_strings(strings, add, need_to_dup) \
1229 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1232 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1233 static char **add_string_to_strings(char **strings, char *add)
1238 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1241 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1243 char **ptr = add_string_to_strings(strings, add);
1244 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1247 #define add_string_to_strings(strings, add) \
1248 xx_add_string_to_strings(__LINE__, strings, add)
1251 static void free_strings(char **strings)
1266 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1268 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1269 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1271 /* fd was not open? */
1281 /* Manipulating the list of open FILEs */
1282 static FILE *remember_FILE(FILE *fp)
1285 struct FILE_list *n = xmalloc(sizeof(*n));
1286 n->next = G.FILE_list;
1290 close_on_exec_on(n->fd);
1294 static void fclose_and_forget(FILE *fp)
1296 struct FILE_list **pp = &G.FILE_list;
1298 struct FILE_list *cur = *pp;
1299 if (cur->fp == fp) {
1308 static int save_FILEs_on_redirect(int fd)
1310 struct FILE_list *fl = G.FILE_list;
1313 /* We use it only on script files, they are all CLOEXEC */
1314 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1321 static void restore_redirected_FILEs(void)
1323 struct FILE_list *fl = G.FILE_list;
1325 int should_be = fileno(fl->fp);
1326 if (fl->fd != should_be) {
1327 xmove_fd(fl->fd, should_be);
1333 #if ENABLE_FEATURE_SH_STANDALONE
1334 static void close_all_FILE_list(void)
1336 struct FILE_list *fl = G.FILE_list;
1338 /* fclose would also free FILE object.
1339 * It is disastrous if we share memory with a vforked parent.
1340 * I'm not sure we never come here after vfork.
1341 * Therefore just close fd, nothing more.
1343 /*fclose(fl->fp); - unsafe */
1351 /* Helpers for setting new $n and restoring them back
1353 typedef struct save_arg_t {
1357 smallint sv_g_malloced;
1360 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1364 sv->sv_argv0 = argv[0];
1365 sv->sv_g_argv = G.global_argv;
1366 sv->sv_g_argc = G.global_argc;
1367 sv->sv_g_malloced = G.global_args_malloced;
1369 argv[0] = G.global_argv[0]; /* retain $0 */
1370 G.global_argv = argv;
1371 G.global_args_malloced = 0;
1379 static void restore_G_args(save_arg_t *sv, char **argv)
1383 if (G.global_args_malloced) {
1384 /* someone ran "set -- arg1 arg2 ...", undo */
1386 while (*++pp) /* note: does not free $0 */
1388 free(G.global_argv);
1390 argv[0] = sv->sv_argv0;
1391 G.global_argv = sv->sv_g_argv;
1392 G.global_argc = sv->sv_g_argc;
1393 G.global_args_malloced = sv->sv_g_malloced;
1397 /* Basic theory of signal handling in shell
1398 * ========================================
1399 * This does not describe what hush does, rather, it is current understanding
1400 * what it _should_ do. If it doesn't, it's a bug.
1401 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1403 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1404 * is finished or backgrounded. It is the same in interactive and
1405 * non-interactive shells, and is the same regardless of whether
1406 * a user trap handler is installed or a shell special one is in effect.
1407 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1408 * backgrounds (i.e. stops) or kills all members of currently running
1411 * Wait builtin is interruptible by signals for which user trap is set
1412 * or by SIGINT in interactive shell.
1414 * Trap handlers will execute even within trap handlers. (right?)
1416 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1417 * except for handlers set to '' (empty string).
1419 * If job control is off, backgrounded commands ("cmd &")
1420 * have SIGINT, SIGQUIT set to SIG_IGN.
1422 * Commands which are run in command substitution ("`cmd`")
1423 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1425 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1426 * by the shell from its parent.
1428 * Signals which differ from SIG_DFL action
1429 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1432 * SIGTERM (interactive): ignore
1433 * SIGHUP (interactive):
1434 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1435 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1436 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1437 * that all pipe members are stopped. Try this in bash:
1438 * while :; do :; done - ^Z does not background it
1439 * (while :; do :; done) - ^Z backgrounds it
1440 * SIGINT (interactive): wait for last pipe, ignore the rest
1441 * of the command line, show prompt. NB: ^C does not send SIGINT
1442 * to interactive shell while shell is waiting for a pipe,
1443 * since shell is bg'ed (is not in foreground process group).
1444 * Example 1: this waits 5 sec, but does not execute ls:
1445 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1446 * Example 2: this does not wait and does not execute ls:
1447 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1448 * Example 3: this does not wait 5 sec, but executes ls:
1449 * "sleep 5; ls -l" + press ^C
1450 * Example 4: this does not wait and does not execute ls:
1451 * "sleep 5 & wait; ls -l" + press ^C
1453 * (What happens to signals which are IGN on shell start?)
1454 * (What happens with signal mask on shell start?)
1456 * Old implementation
1457 * ==================
1458 * We use in-kernel pending signal mask to determine which signals were sent.
1459 * We block all signals which we don't want to take action immediately,
1460 * i.e. we block all signals which need to have special handling as described
1461 * above, and all signals which have traps set.
1462 * After each pipe execution, we extract any pending signals via sigtimedwait()
1465 * unsigned special_sig_mask: a mask of such "special" signals
1466 * sigset_t blocked_set: current blocked signal set
1469 * clear bit in blocked_set unless it is also in special_sig_mask
1470 * "trap 'cmd' SIGxxx":
1471 * set bit in blocked_set (even if 'cmd' is '')
1472 * after [v]fork, if we plan to be a shell:
1473 * unblock signals with special interactive handling
1474 * (child shell is not interactive),
1475 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1476 * after [v]fork, if we plan to exec:
1477 * POSIX says fork clears pending signal mask in child - no need to clear it.
1478 * Restore blocked signal set to one inherited by shell just prior to exec.
1480 * Note: as a result, we do not use signal handlers much. The only uses
1481 * are to count SIGCHLDs
1482 * and to restore tty pgrp on signal-induced exit.
1485 * Standard says "When a subshell is entered, traps that are not being ignored
1486 * are set to the default actions". bash interprets it so that traps which
1487 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1489 * Problem: the above approach makes it unwieldy to catch signals while
1490 * we are in read builtin, or while we read commands from stdin:
1491 * masked signals are not visible!
1493 * New implementation
1494 * ==================
1495 * We record each signal we are interested in by installing signal handler
1496 * for them - a bit like emulating kernel pending signal mask in userspace.
1497 * We are interested in: signals which need to have special handling
1498 * as described above, and all signals which have traps set.
1499 * Signals are recorded in pending_set.
1500 * After each pipe execution, we extract any pending signals
1503 * unsigned special_sig_mask: a mask of shell-special signals.
1504 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1505 * char *traps[sig] if trap for sig is set (even if it's '').
1506 * sigset_t pending_set: set of sigs we received.
1509 * if sig is in special_sig_mask, set handler back to:
1510 * record_pending_signo, or to IGN if it's a tty stop signal
1511 * if sig is in fatal_sig_mask, set handler back to sigexit.
1512 * else: set handler back to SIG_DFL
1513 * "trap 'cmd' SIGxxx":
1514 * set handler to record_pending_signo.
1516 * set handler to SIG_IGN.
1517 * after [v]fork, if we plan to be a shell:
1518 * set signals with special interactive handling to SIG_DFL
1519 * (because child shell is not interactive),
1520 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1521 * after [v]fork, if we plan to exec:
1522 * POSIX says fork clears pending signal mask in child - no need to clear it.
1524 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1525 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1528 * Standard says "When a subshell is entered, traps that are not being ignored
1529 * are set to the default actions". bash interprets it so that traps which
1530 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1533 SPECIAL_INTERACTIVE_SIGS = 0
1538 SPECIAL_JOBSTOP_SIGS = 0
1547 static void record_pending_signo(int sig)
1549 sigaddset(&G.pending_set, sig);
1550 #if ENABLE_HUSH_FAST
1551 if (sig == SIGCHLD) {
1553 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1558 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1560 struct sigaction old_sa;
1562 /* We could use signal() to install handlers... almost:
1563 * except that we need to mask ALL signals while handlers run.
1564 * I saw signal nesting in strace, race window isn't small.
1565 * SA_RESTART is also needed, but in Linux, signal()
1566 * sets SA_RESTART too.
1568 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1569 /* sigfillset(&G.sa.sa_mask); - already done */
1570 /* G.sa.sa_flags = SA_RESTART; - already done */
1571 G.sa.sa_handler = handler;
1572 sigaction(sig, &G.sa, &old_sa);
1573 return old_sa.sa_handler;
1576 static void hush_exit(int exitcode) NORETURN;
1577 static void fflush_and__exit(void) NORETURN;
1578 static void restore_ttypgrp_and__exit(void) NORETURN;
1580 static void restore_ttypgrp_and__exit(void)
1582 /* xfunc has failed! die die die */
1583 /* no EXIT traps, this is an escape hatch! */
1585 hush_exit(xfunc_error_retval);
1588 /* Needed only on some libc:
1589 * It was observed that on exit(), fgetc'ed buffered data
1590 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1591 * With the net effect that even after fork(), not vfork(),
1592 * exit() in NOEXECed applet in "sh SCRIPT":
1593 * noexec_applet_here
1594 * echo END_OF_SCRIPT
1595 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1596 * This makes "echo END_OF_SCRIPT" executed twice.
1597 * Similar problems can be seen with die_if_script() -> xfunc_die()
1598 * and in `cmd` handling.
1599 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1601 static void fflush_and__exit(void)
1604 _exit(xfunc_error_retval);
1609 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1610 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1611 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1612 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1614 /* Restores tty foreground process group, and exits.
1615 * May be called as signal handler for fatal signal
1616 * (will resend signal to itself, producing correct exit state)
1617 * or called directly with -EXITCODE.
1618 * We also call it if xfunc is exiting.
1620 static void sigexit(int sig) NORETURN;
1621 static void sigexit(int sig)
1623 /* Careful: we can end up here after [v]fork. Do not restore
1624 * tty pgrp then, only top-level shell process does that */
1625 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1626 /* Disable all signals: job control, SIGPIPE, etc.
1627 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1629 sigprocmask_allsigs(SIG_BLOCK);
1630 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1633 /* Not a signal, just exit */
1637 kill_myself_with_sig(sig); /* does not return */
1641 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1642 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1646 static sighandler_t pick_sighandler(unsigned sig)
1648 sighandler_t handler = SIG_DFL;
1649 if (sig < sizeof(unsigned)*8) {
1650 unsigned sigmask = (1 << sig);
1654 if (G_fatal_sig_mask & sigmask)
1658 /* sig has special handling? */
1659 if (G.special_sig_mask & sigmask) {
1660 handler = record_pending_signo;
1661 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1662 * in order to ignore them: they will be raised
1663 * in an endless loop when we try to do some
1664 * terminal ioctls! We do have to _ignore_ these.
1666 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1673 /* Restores tty foreground process group, and exits. */
1674 static void hush_exit(int exitcode)
1676 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1677 save_history(G.line_input_state);
1681 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1683 /* argv[0] is unused */
1684 argv[1] = G.traps[0];
1686 G.exiting = 1; /* prevent EXIT trap recursion */
1687 /* Note: G.traps[0] is not cleared!
1688 * "trap" will still show it, if executed
1693 #if ENABLE_FEATURE_CLEAN_UP
1695 struct variable *cur_var;
1696 if (G.cwd != bb_msg_unknown)
1698 cur_var = G.top_var;
1700 struct variable *tmp = cur_var;
1701 if (!cur_var->max_len)
1702 free(cur_var->varstr);
1703 cur_var = cur_var->next;
1711 sigexit(- (exitcode & 0xff));
1718 //TODO: return a mask of ALL handled sigs?
1719 static int check_and_run_traps(void)
1726 if (sigisemptyset(&G.pending_set))
1731 if (sigismember(&G.pending_set, sig)) {
1732 sigdelset(&G.pending_set, sig);
1735 } while (sig < NSIG);
1738 if (G.traps && G.traps[sig]) {
1739 if (G.traps[sig][0]) {
1740 /* We have user-defined handler */
1741 smalluint save_rcode;
1743 /* argv[0] is unused */
1744 argv[1] = G.traps[sig];
1746 save_rcode = G.last_exitcode;
1748 G.last_exitcode = save_rcode;
1750 } /* else: "" trap, ignoring signal */
1753 /* not a trap: special action */
1756 /* Builtin was ^C'ed, make it look prettier: */
1764 /* bash is observed to signal whole process groups,
1765 * not individual processes */
1766 for (job = G.job_list; job; job = job->next) {
1769 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1770 if (kill(- job->pgrp, SIGHUP) == 0)
1771 kill(- job->pgrp, SIGCONT);
1776 #if ENABLE_HUSH_FAST
1779 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1781 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1782 * This simplifies wait builtin a bit.
1786 default: /* ignored: */
1787 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1789 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1790 * Example: wait is not interrupted by TERM
1791 * in interactive shell, because TERM is ignored.
1800 static const char *get_cwd(int force)
1802 if (force || G.cwd == NULL) {
1803 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1804 * we must not try to free(bb_msg_unknown) */
1805 if (G.cwd == bb_msg_unknown)
1807 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1809 G.cwd = bb_msg_unknown;
1816 * Shell and environment variable support
1818 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1820 struct variable **pp;
1821 struct variable *cur;
1824 while ((cur = *pp) != NULL) {
1825 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1832 static const char* FAST_FUNC get_local_var_value(const char *name)
1834 struct variable **vpp;
1835 unsigned len = strlen(name);
1837 if (G.expanded_assignments) {
1838 char **cpp = G.expanded_assignments;
1841 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1842 return cp + len + 1;
1847 vpp = get_ptr_to_local_var(name, len);
1849 return (*vpp)->varstr + len + 1;
1851 if (strcmp(name, "PPID") == 0)
1852 return utoa(G.root_ppid);
1853 // bash compat: UID? EUID?
1854 #if ENABLE_HUSH_RANDOM_SUPPORT
1855 if (strcmp(name, "RANDOM") == 0)
1856 return utoa(next_random(&G.random_gen));
1861 /* str holds "NAME=VAL" and is expected to be malloced.
1862 * We take ownership of it.
1864 * 0: do not change export flag
1865 * (if creating new variable, flag will be 0)
1866 * 1: set export flag and putenv the variable
1867 * -1: clear export flag and unsetenv the variable
1868 * flg_read_only is set only when we handle -R var=val
1870 #if !BB_MMU && ENABLE_HUSH_LOCAL
1871 /* all params are used */
1872 #elif BB_MMU && ENABLE_HUSH_LOCAL
1873 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1874 set_local_var(str, flg_export, local_lvl)
1875 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1876 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1877 set_local_var(str, flg_export)
1878 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1879 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1880 set_local_var(str, flg_export, flg_read_only)
1882 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1884 struct variable **var_pp;
1885 struct variable *cur;
1889 eq_sign = strchr(str, '=');
1890 if (!eq_sign) { /* not expected to ever happen? */
1895 name_len = eq_sign - str + 1; /* including '=' */
1896 var_pp = &G.top_var;
1897 while ((cur = *var_pp) != NULL) {
1898 if (strncmp(cur->varstr, str, name_len) != 0) {
1899 var_pp = &cur->next;
1902 /* We found an existing var with this name */
1903 if (cur->flg_read_only) {
1907 bb_error_msg("%s: readonly variable", str);
1911 if (flg_export == -1) { // "&& cur->flg_export" ?
1912 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1917 #if ENABLE_HUSH_LOCAL
1918 if (cur->func_nest_level < local_lvl) {
1919 /* New variable is declared as local,
1920 * and existing one is global, or local
1921 * from enclosing function.
1922 * Remove and save old one: */
1923 *var_pp = cur->next;
1924 cur->next = *G.shadowed_vars_pp;
1925 *G.shadowed_vars_pp = cur;
1926 /* bash 3.2.33(1) and exported vars:
1928 * # f() { local z=a; env | grep ^z; }
1934 if (cur->flg_export)
1939 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1944 if (cur->max_len != 0) {
1945 if (cur->max_len >= strlen(str)) {
1946 /* This one is from startup env, reuse space */
1947 strcpy(cur->varstr, str);
1951 /* max_len == 0 signifies "malloced" var, which we can
1952 * (and has to) free */
1956 goto set_str_and_exp;
1959 /* Not found - create new variable struct */
1960 cur = xzalloc(sizeof(*cur));
1961 #if ENABLE_HUSH_LOCAL
1962 cur->func_nest_level = local_lvl;
1964 cur->next = *var_pp;
1970 cur->flg_read_only = flg_read_only;
1973 if (flg_export == 1)
1974 cur->flg_export = 1;
1975 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1976 cmdedit_update_prompt();
1977 if (cur->flg_export) {
1978 if (flg_export == -1) {
1979 cur->flg_export = 0;
1980 /* unsetenv was already done */
1982 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1983 return putenv(cur->varstr);
1989 /* Used at startup and after each cd */
1990 static void set_pwd_var(int exp)
1992 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1993 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1996 static int unset_local_var_len(const char *name, int name_len)
1998 struct variable *cur;
1999 struct variable **var_pp;
2002 return EXIT_SUCCESS;
2003 var_pp = &G.top_var;
2004 while ((cur = *var_pp) != NULL) {
2005 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2006 if (cur->flg_read_only) {
2007 bb_error_msg("%s: readonly variable", name);
2008 return EXIT_FAILURE;
2010 *var_pp = cur->next;
2011 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2012 bb_unsetenv(cur->varstr);
2013 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2014 cmdedit_update_prompt();
2018 return EXIT_SUCCESS;
2020 var_pp = &cur->next;
2022 return EXIT_SUCCESS;
2025 static int unset_local_var(const char *name)
2027 return unset_local_var_len(name, strlen(name));
2030 static void unset_vars(char **strings)
2038 const char *eq = strchrnul(*v, '=');
2039 unset_local_var_len(*v, (int)(eq - *v));
2045 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2047 char *var = xasprintf("%s=%s", name, val);
2048 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2053 * Helpers for "var1=val1 var2=val2 cmd" feature
2055 static void add_vars(struct variable *var)
2057 struct variable *next;
2061 var->next = G.top_var;
2063 if (var->flg_export) {
2064 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2065 putenv(var->varstr);
2067 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2073 static struct variable *set_vars_and_save_old(char **strings)
2076 struct variable *old = NULL;
2082 struct variable *var_p;
2083 struct variable **var_pp;
2086 eq = strchr(*s, '=');
2088 var_pp = get_ptr_to_local_var(*s, eq - *s);
2090 /* Remove variable from global linked list */
2092 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2093 *var_pp = var_p->next;
2094 /* Add it to returned list */
2098 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2109 static void reinit_unicode_for_hush(void)
2111 /* Unicode support should be activated even if LANG is set
2112 * _during_ shell execution, not only if it was set when
2113 * shell was started. Therefore, re-check LANG every time:
2115 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2116 || ENABLE_UNICODE_USING_LOCALE
2118 const char *s = get_local_var_value("LC_ALL");
2119 if (!s) s = get_local_var_value("LC_CTYPE");
2120 if (!s) s = get_local_var_value("LANG");
2129 static int FAST_FUNC static_get(struct in_str *i)
2140 static int FAST_FUNC static_peek(struct in_str *i)
2145 #if ENABLE_HUSH_INTERACTIVE
2147 static void cmdedit_update_prompt(void)
2149 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2150 G.PS1 = get_local_var_value("PS1");
2153 G.PS2 = get_local_var_value("PS2");
2161 static const char *setup_prompt_string(int promptmode)
2163 const char *prompt_str;
2164 debug_printf("setup_prompt_string %d ", promptmode);
2165 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2166 /* Set up the prompt */
2167 if (promptmode == 0) { /* PS1 */
2169 /* bash uses $PWD value, even if it is set by user.
2170 * It uses current dir only if PWD is unset.
2171 * We always use current dir. */
2172 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2177 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2178 debug_printf("result '%s'\n", prompt_str);
2182 static void get_user_input(struct in_str *i)
2185 const char *prompt_str;
2187 prompt_str = setup_prompt_string(i->promptmode);
2188 # if ENABLE_FEATURE_EDITING
2189 /* Enable command line editing only while a command line
2190 * is actually being read */
2192 reinit_unicode_for_hush();
2194 /* buglet: SIGINT will not make new prompt to appear _at once_,
2195 * only after <Enter>. (^C will work) */
2196 r = read_line_input(G.line_input_state, prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, /*timeout*/ -1);
2197 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2198 check_and_run_traps();
2199 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2200 i->eof_flag = (r < 0);
2201 if (i->eof_flag) { /* EOF/error detected */
2202 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
2203 G.user_input_buf[1] = '\0';
2208 if (i->last_char == '\0' || i->last_char == '\n') {
2209 /* Why check_and_run_traps here? Try this interactively:
2210 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2211 * $ <[enter], repeatedly...>
2212 * Without check_and_run_traps, handler never runs.
2214 check_and_run_traps();
2215 fputs(prompt_str, stdout);
2218 G.user_input_buf[0] = r = fgetc(i->file);
2219 /*G.user_input_buf[1] = '\0'; - already is and never changed */
2220 } while (G.flag_SIGINT);
2221 i->eof_flag = (r == EOF);
2223 i->p = G.user_input_buf;
2226 #endif /* INTERACTIVE */
2228 /* This is the magic location that prints prompts
2229 * and gets data back from the user */
2230 static int FAST_FUNC file_get(struct in_str *i)
2234 /* If there is data waiting, eat it up */
2235 if (i->p && *i->p) {
2236 #if ENABLE_HUSH_INTERACTIVE
2240 if (i->eof_flag && !*i->p)
2242 /* note: ch is never NUL */
2244 /* need to double check i->file because we might be doing something
2245 * more complicated by now, like sourcing or substituting. */
2246 #if ENABLE_HUSH_INTERACTIVE
2247 if (G_interactive_fd && i->file == stdin) {
2250 } while (!*i->p); /* need non-empty line */
2251 i->promptmode = 1; /* PS2 */
2255 do ch = fgetc(i->file); while (ch == '\0');
2257 debug_printf("file_get: got '%c' %d\n", ch, ch);
2262 /* All callers guarantee this routine will never
2263 * be used right after a newline, so prompting is not needed.
2265 static int FAST_FUNC file_peek(struct in_str *i)
2268 if (i->p && *i->p) {
2269 if (i->eof_flag && !i->p[1])
2272 /* note: ch is never NUL */
2274 do ch = fgetc(i->file); while (ch == '\0');
2275 i->eof_flag = (ch == EOF);
2276 i->peek_buf[0] = ch;
2277 i->peek_buf[1] = '\0';
2279 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2283 static void setup_file_in_str(struct in_str *i, FILE *f)
2285 memset(i, 0, sizeof(*i));
2286 i->peek = file_peek;
2288 /* i->promptmode = 0; - PS1 (memset did it) */
2293 static void setup_string_in_str(struct in_str *i, const char *s)
2295 memset(i, 0, sizeof(*i));
2296 i->peek = static_peek;
2297 i->get = static_get;
2298 /* i->promptmode = 0; - PS1 (memset did it) */
2300 /* i->eof_flag = 0; */
2307 #define B_CHUNK (32 * sizeof(char*))
2309 static void o_reset_to_empty_unquoted(o_string *o)
2312 o->has_quoted_part = 0;
2317 static void o_free(o_string *o)
2320 memset(o, 0, sizeof(*o));
2323 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2328 static void o_grow_by(o_string *o, int len)
2330 if (o->length + len > o->maxlen) {
2331 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
2332 o->data = xrealloc(o->data, 1 + o->maxlen);
2336 static void o_addchr(o_string *o, int ch)
2338 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2340 o->data[o->length] = ch;
2342 o->data[o->length] = '\0';
2345 static void o_addblock(o_string *o, const char *str, int len)
2348 memcpy(&o->data[o->length], str, len);
2350 o->data[o->length] = '\0';
2353 static void o_addstr(o_string *o, const char *str)
2355 o_addblock(o, str, strlen(str));
2359 static void nommu_addchr(o_string *o, int ch)
2365 # define nommu_addchr(o, str) ((void)0)
2368 static void o_addstr_with_NUL(o_string *o, const char *str)
2370 o_addblock(o, str, strlen(str) + 1);
2374 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2375 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2376 * Apparently, on unquoted $v bash still does globbing
2377 * ("v='*.txt'; echo $v" prints all .txt files),
2378 * but NOT brace expansion! Thus, there should be TWO independent
2379 * quoting mechanisms on $v expansion side: one protects
2380 * $v from brace expansion, and other additionally protects "$v" against globbing.
2381 * We have only second one.
2384 #if ENABLE_HUSH_BRACE_EXPANSION
2385 # define MAYBE_BRACES "{}"
2387 # define MAYBE_BRACES ""
2390 /* My analysis of quoting semantics tells me that state information
2391 * is associated with a destination, not a source.
2393 static void o_addqchr(o_string *o, int ch)
2396 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2401 o->data[o->length] = '\\';
2404 o->data[o->length] = ch;
2406 o->data[o->length] = '\0';
2409 static void o_addQchr(o_string *o, int ch)
2412 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2413 && strchr("*?[\\" MAYBE_BRACES, ch)
2416 o->data[o->length] = '\\';
2420 o->data[o->length] = ch;
2422 o->data[o->length] = '\0';
2425 static void o_addqblock(o_string *o, const char *str, int len)
2430 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2431 if (ordinary_cnt > len) /* paranoia */
2433 o_addblock(o, str, ordinary_cnt);
2434 if (ordinary_cnt == len)
2435 return; /* NUL is already added by o_addblock */
2436 str += ordinary_cnt;
2437 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2441 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2443 o->data[o->length] = '\\';
2447 o->data[o->length] = ch;
2450 o->data[o->length] = '\0';
2453 static void o_addQblock(o_string *o, const char *str, int len)
2455 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2456 o_addblock(o, str, len);
2459 o_addqblock(o, str, len);
2462 static void o_addQstr(o_string *o, const char *str)
2464 o_addQblock(o, str, strlen(str));
2467 /* A special kind of o_string for $VAR and `cmd` expansion.
2468 * It contains char* list[] at the beginning, which is grown in 16 element
2469 * increments. Actual string data starts at the next multiple of 16 * (char*).
2470 * list[i] contains an INDEX (int!) into this string data.
2471 * It means that if list[] needs to grow, data needs to be moved higher up
2472 * but list[i]'s need not be modified.
2473 * NB: remembering how many list[i]'s you have there is crucial.
2474 * o_finalize_list() operation post-processes this structure - calculates
2475 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2477 #if DEBUG_EXPAND || DEBUG_GLOB
2478 static void debug_print_list(const char *prefix, o_string *o, int n)
2480 char **list = (char**)o->data;
2481 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2485 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2486 prefix, list, n, string_start, o->length, o->maxlen,
2487 !!(o->o_expflags & EXP_FLAG_GLOB),
2489 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2492 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2493 o->data + (int)(uintptr_t)list[i] + string_start,
2494 o->data + (int)(uintptr_t)list[i] + string_start);
2498 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2500 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2504 # define debug_print_list(prefix, o, n) ((void)0)
2507 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2508 * in list[n] so that it points past last stored byte so far.
2509 * It returns n+1. */
2510 static int o_save_ptr_helper(o_string *o, int n)
2512 char **list = (char**)o->data;
2516 if (!o->has_empty_slot) {
2517 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2518 string_len = o->length - string_start;
2519 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2520 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2521 /* list[n] points to string_start, make space for 16 more pointers */
2522 o->maxlen += 0x10 * sizeof(list[0]);
2523 o->data = xrealloc(o->data, o->maxlen + 1);
2524 list = (char**)o->data;
2525 memmove(list + n + 0x10, list + n, string_len);
2526 o->length += 0x10 * sizeof(list[0]);
2528 debug_printf_list("list[%d]=%d string_start=%d\n",
2529 n, string_len, string_start);
2532 /* We have empty slot at list[n], reuse without growth */
2533 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2534 string_len = o->length - string_start;
2535 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2536 n, string_len, string_start);
2537 o->has_empty_slot = 0;
2539 o->has_quoted_part = 0;
2540 list[n] = (char*)(uintptr_t)string_len;
2544 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2545 static int o_get_last_ptr(o_string *o, int n)
2547 char **list = (char**)o->data;
2548 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2550 return ((int)(uintptr_t)list[n-1]) + string_start;
2553 #if ENABLE_HUSH_BRACE_EXPANSION
2554 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2555 * first, it processes even {a} (no commas), second,
2556 * I didn't manage to make it return strings when they don't match
2557 * existing files. Need to re-implement it.
2561 static int glob_needed(const char *s)
2570 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2576 /* Return pointer to next closing brace or to comma */
2577 static const char *next_brace_sub(const char *cp)
2581 while (*cp != '\0') {
2588 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2594 return *cp != '\0' ? cp : NULL;
2596 /* Recursive brace globber. Note: may garble pattern[]. */
2597 static int glob_brace(char *pattern, o_string *o, int n)
2599 char *new_pattern_buf;
2606 debug_printf_glob("glob_brace('%s')\n", pattern);
2612 if (*begin == '{') {
2613 /* Find the first sub-pattern and at the same time
2614 * find the rest after the closing brace */
2615 next = next_brace_sub(begin);
2617 /* An illegal expression */
2621 /* "{abc}" with no commas - illegal
2622 * brace expr, disregard and skip it */
2628 if (*begin == '\\' && begin[1] != '\0')
2632 debug_printf_glob("begin:%s\n", begin);
2633 debug_printf_glob("next:%s\n", next);
2635 /* Now find the end of the whole brace expression */
2637 while (*rest != '}') {
2638 rest = next_brace_sub(rest);
2640 /* An illegal expression */
2643 debug_printf_glob("rest:%s\n", rest);
2645 rest_len = strlen(++rest) + 1;
2647 /* We are sure the brace expression is well-formed */
2649 /* Allocate working buffer large enough for our work */
2650 new_pattern_buf = xmalloc(strlen(pattern));
2652 /* We have a brace expression. BEGIN points to the opening {,
2653 * NEXT points past the terminator of the first element, and REST
2654 * points past the final }. We will accumulate result names from
2655 * recursive runs for each brace alternative in the buffer using
2660 /* Construct the new glob expression */
2663 mempcpy(new_pattern_buf,
2664 /* We know the prefix for all sub-patterns */
2665 pattern, begin - pattern),
2669 /* Note: glob_brace() may garble new_pattern_buf[].
2670 * That's why we re-copy prefix every time (1st memcpy above).
2672 n = glob_brace(new_pattern_buf, o, n);
2674 /* We saw the last entry */
2678 next = next_brace_sub(next);
2680 free(new_pattern_buf);
2688 memset(&globdata, 0, sizeof(globdata));
2689 gr = glob(pattern, 0, NULL, &globdata);
2690 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2692 if (gr == GLOB_NOMATCH) {
2693 globfree(&globdata);
2694 /* NB: garbles parameter */
2695 unbackslash(pattern);
2696 o_addstr_with_NUL(o, pattern);
2697 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2698 return o_save_ptr_helper(o, n);
2700 if (gr == GLOB_NOSPACE)
2701 bb_error_msg_and_die(bb_msg_memory_exhausted);
2702 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2703 * but we didn't specify it. Paranoia again. */
2704 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2706 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2707 char **argv = globdata.gl_pathv;
2709 o_addstr_with_NUL(o, *argv);
2710 n = o_save_ptr_helper(o, n);
2716 globfree(&globdata);
2720 /* Performs globbing on last list[],
2721 * saving each result as a new list[].
2723 static int perform_glob(o_string *o, int n)
2725 char *pattern, *copy;
2727 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2729 return o_save_ptr_helper(o, n);
2730 pattern = o->data + o_get_last_ptr(o, n);
2731 debug_printf_glob("glob pattern '%s'\n", pattern);
2732 if (!glob_needed(pattern)) {
2733 /* unbackslash last string in o in place, fix length */
2734 o->length = unbackslash(pattern) - o->data;
2735 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2736 return o_save_ptr_helper(o, n);
2739 copy = xstrdup(pattern);
2740 /* "forget" pattern in o */
2741 o->length = pattern - o->data;
2742 n = glob_brace(copy, o, n);
2745 debug_print_list("perform_glob returning", o, n);
2749 #else /* !HUSH_BRACE_EXPANSION */
2752 static int glob_needed(const char *s)
2761 if (*s == '*' || *s == '[' || *s == '?')
2767 /* Performs globbing on last list[],
2768 * saving each result as a new list[].
2770 static int perform_glob(o_string *o, int n)
2776 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2778 return o_save_ptr_helper(o, n);
2779 pattern = o->data + o_get_last_ptr(o, n);
2780 debug_printf_glob("glob pattern '%s'\n", pattern);
2781 if (!glob_needed(pattern)) {
2783 /* unbackslash last string in o in place, fix length */
2784 o->length = unbackslash(pattern) - o->data;
2785 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2786 return o_save_ptr_helper(o, n);
2789 memset(&globdata, 0, sizeof(globdata));
2790 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2791 * If we glob "*.\*" and don't find anything, we need
2792 * to fall back to using literal "*.*", but GLOB_NOCHECK
2793 * will return "*.\*"!
2795 gr = glob(pattern, 0, NULL, &globdata);
2796 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2798 if (gr == GLOB_NOMATCH) {
2799 globfree(&globdata);
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;
2810 /* "forget" pattern in o */
2811 o->length = pattern - o->data;
2813 o_addstr_with_NUL(o, *argv);
2814 n = o_save_ptr_helper(o, n);
2820 globfree(&globdata);
2822 debug_print_list("perform_glob returning", o, n);
2826 #endif /* !HUSH_BRACE_EXPANSION */
2828 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2829 * Otherwise, just finish current list[] and start new */
2830 static int o_save_ptr(o_string *o, int n)
2832 if (o->o_expflags & EXP_FLAG_GLOB) {
2833 /* If o->has_empty_slot, list[n] was already globbed
2834 * (if it was requested back then when it was filled)
2835 * so don't do that again! */
2836 if (!o->has_empty_slot)
2837 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2839 return o_save_ptr_helper(o, n);
2842 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2843 static char **o_finalize_list(o_string *o, int n)
2848 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2850 debug_print_list("finalized", o, n);
2851 debug_printf_expand("finalized n:%d\n", n);
2852 list = (char**)o->data;
2853 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2857 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2862 static void free_pipe_list(struct pipe *pi);
2864 /* Returns pi->next - next pipe in the list */
2865 static struct pipe *free_pipe(struct pipe *pi)
2870 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2871 for (i = 0; i < pi->num_cmds; i++) {
2872 struct command *command;
2873 struct redir_struct *r, *rnext;
2875 command = &pi->cmds[i];
2876 debug_printf_clean(" command %d:\n", i);
2877 if (command->argv) {
2881 for (a = 0, p = command->argv; *p; a++, p++) {
2882 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2885 free_strings(command->argv);
2886 //command->argv = NULL;
2888 /* not "else if": on syntax error, we may have both! */
2889 if (command->group) {
2890 debug_printf_clean(" begin group (cmd_type:%d)\n",
2892 free_pipe_list(command->group);
2893 debug_printf_clean(" end group\n");
2894 //command->group = NULL;
2896 /* else is crucial here.
2897 * If group != NULL, child_func is meaningless */
2898 #if ENABLE_HUSH_FUNCTIONS
2899 else if (command->child_func) {
2900 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2901 command->child_func->parent_cmd = NULL;
2905 free(command->group_as_string);
2906 //command->group_as_string = NULL;
2908 for (r = command->redirects; r; r = rnext) {
2909 debug_printf_clean(" redirect %d%s",
2910 r->rd_fd, redir_table[r->rd_type].descrip);
2911 /* guard against the case >$FOO, where foo is unset or blank */
2912 if (r->rd_filename) {
2913 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2914 free(r->rd_filename);
2915 //r->rd_filename = NULL;
2917 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2921 //command->redirects = NULL;
2923 free(pi->cmds); /* children are an array, they get freed all at once */
2927 //pi->cmdtext = NULL;
2935 static void free_pipe_list(struct pipe *pi)
2939 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2941 debug_printf_clean("pipe followup code %d\n", pi->followup);
2947 /*** Parsing routines ***/
2949 #ifndef debug_print_tree
2950 static void debug_print_tree(struct pipe *pi, int lvl)
2952 static const char *const PIPE[] = {
2958 static const char *RES[] = {
2959 [RES_NONE ] = "NONE" ,
2962 [RES_THEN ] = "THEN" ,
2963 [RES_ELIF ] = "ELIF" ,
2964 [RES_ELSE ] = "ELSE" ,
2967 # if ENABLE_HUSH_LOOPS
2968 [RES_FOR ] = "FOR" ,
2969 [RES_WHILE] = "WHILE",
2970 [RES_UNTIL] = "UNTIL",
2972 [RES_DONE ] = "DONE" ,
2974 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2977 # if ENABLE_HUSH_CASE
2978 [RES_CASE ] = "CASE" ,
2979 [RES_CASE_IN ] = "CASE_IN" ,
2980 [RES_MATCH] = "MATCH",
2981 [RES_CASE_BODY] = "CASE_BODY",
2982 [RES_ESAC ] = "ESAC" ,
2984 [RES_XXXX ] = "XXXX" ,
2985 [RES_SNTX ] = "SNTX" ,
2987 static const char *const CMDTYPE[] = {
2991 # if ENABLE_HUSH_FUNCTIONS
3000 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3001 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3003 while (prn < pi->num_cmds) {
3004 struct command *command = &pi->cmds[prn];
3005 char **argv = command->argv;
3007 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3009 command->assignment_cnt);
3010 if (command->group) {
3011 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3012 CMDTYPE[command->cmd_type],
3015 , " group_as_string:", command->group_as_string
3020 debug_print_tree(command->group, lvl+1);
3024 if (argv) while (*argv) {
3025 fdprintf(2, " '%s'", *argv);
3035 #endif /* debug_print_tree */
3037 static struct pipe *new_pipe(void)
3040 pi = xzalloc(sizeof(struct pipe));
3041 /*pi->followup = 0; - deliberately invalid value */
3042 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3046 /* Command (member of a pipe) is complete, or we start a new pipe
3047 * if ctx->command is NULL.
3048 * No errors possible here.
3050 static int done_command(struct parse_context *ctx)
3052 /* The command is really already in the pipe structure, so
3053 * advance the pipe counter and make a new, null command. */
3054 struct pipe *pi = ctx->pipe;
3055 struct command *command = ctx->command;
3057 #if 0 /* Instead we emit error message at run time */
3058 if (ctx->pending_redirect) {
3059 /* For example, "cmd >" (no filename to redirect to) */
3060 die_if_script("syntax error: %s", "invalid redirect");
3061 ctx->pending_redirect = NULL;
3066 if (IS_NULL_CMD(command)) {
3067 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3071 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3072 //debug_print_tree(ctx->list_head, 20);
3074 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3077 /* Only real trickiness here is that the uncommitted
3078 * command structure is not counted in pi->num_cmds. */
3079 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3080 ctx->command = command = &pi->cmds[pi->num_cmds];
3082 memset(command, 0, sizeof(*command));
3083 return pi->num_cmds; /* used only for 0/nonzero check */
3086 static void done_pipe(struct parse_context *ctx, pipe_style type)
3090 debug_printf_parse("done_pipe entered, followup %d\n", type);
3091 /* Close previous command */
3092 not_null = done_command(ctx);
3093 ctx->pipe->followup = type;
3095 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3096 ctx->ctx_inverted = 0;
3097 ctx->pipe->res_word = ctx->ctx_res_w;
3100 /* Without this check, even just <enter> on command line generates
3101 * tree of three NOPs (!). Which is harmless but annoying.
3102 * IOW: it is safe to do it unconditionally. */
3105 || ctx->ctx_res_w == RES_FI
3107 #if ENABLE_HUSH_LOOPS
3108 || ctx->ctx_res_w == RES_DONE
3109 || ctx->ctx_res_w == RES_FOR
3110 || ctx->ctx_res_w == RES_IN
3112 #if ENABLE_HUSH_CASE
3113 || ctx->ctx_res_w == RES_ESAC
3117 debug_printf_parse("done_pipe: adding new pipe: "
3118 "not_null:%d ctx->ctx_res_w:%d\n",
3119 not_null, ctx->ctx_res_w);
3121 ctx->pipe->next = new_p;
3123 /* RES_THEN, RES_DO etc are "sticky" -
3124 * they remain set for pipes inside if/while.
3125 * This is used to control execution.
3126 * RES_FOR and RES_IN are NOT sticky (needed to support
3127 * cases where variable or value happens to match a keyword):
3129 #if ENABLE_HUSH_LOOPS
3130 if (ctx->ctx_res_w == RES_FOR
3131 || ctx->ctx_res_w == RES_IN)
3132 ctx->ctx_res_w = RES_NONE;
3134 #if ENABLE_HUSH_CASE
3135 if (ctx->ctx_res_w == RES_MATCH)
3136 ctx->ctx_res_w = RES_CASE_BODY;
3137 if (ctx->ctx_res_w == RES_CASE)
3138 ctx->ctx_res_w = RES_CASE_IN;
3140 ctx->command = NULL; /* trick done_command below */
3141 /* Create the memory for command, roughly:
3142 * ctx->pipe->cmds = new struct command;
3143 * ctx->command = &ctx->pipe->cmds[0];
3146 //debug_print_tree(ctx->list_head, 10);
3148 debug_printf_parse("done_pipe return\n");
3151 static void initialize_context(struct parse_context *ctx)
3153 memset(ctx, 0, sizeof(*ctx));
3154 ctx->pipe = ctx->list_head = new_pipe();
3155 /* Create the memory for command, roughly:
3156 * ctx->pipe->cmds = new struct command;
3157 * ctx->command = &ctx->pipe->cmds[0];
3162 /* If a reserved word is found and processed, parse context is modified
3163 * and 1 is returned.
3166 struct reserved_combo {
3169 unsigned char assignment_flag;
3173 FLAG_END = (1 << RES_NONE ),
3175 FLAG_IF = (1 << RES_IF ),
3176 FLAG_THEN = (1 << RES_THEN ),
3177 FLAG_ELIF = (1 << RES_ELIF ),
3178 FLAG_ELSE = (1 << RES_ELSE ),
3179 FLAG_FI = (1 << RES_FI ),
3181 # if ENABLE_HUSH_LOOPS
3182 FLAG_FOR = (1 << RES_FOR ),
3183 FLAG_WHILE = (1 << RES_WHILE),
3184 FLAG_UNTIL = (1 << RES_UNTIL),
3185 FLAG_DO = (1 << RES_DO ),
3186 FLAG_DONE = (1 << RES_DONE ),
3187 FLAG_IN = (1 << RES_IN ),
3189 # if ENABLE_HUSH_CASE
3190 FLAG_MATCH = (1 << RES_MATCH),
3191 FLAG_ESAC = (1 << RES_ESAC ),
3193 FLAG_START = (1 << RES_XXXX ),
3196 static const struct reserved_combo* match_reserved_word(o_string *word)
3198 /* Mostly a list of accepted follow-up reserved words.
3199 * FLAG_END means we are done with the sequence, and are ready
3200 * to turn the compound list into a command.
3201 * FLAG_START means the word must start a new compound list.
3203 static const struct reserved_combo reserved_list[] = {
3205 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3206 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3207 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3208 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3209 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3210 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3212 # if ENABLE_HUSH_LOOPS
3213 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3214 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3215 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3216 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3217 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3218 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3220 # if ENABLE_HUSH_CASE
3221 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3222 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3225 const struct reserved_combo *r;
3227 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3228 if (strcmp(word->data, r->literal) == 0)
3233 /* Return 0: not a keyword, 1: keyword
3235 static int reserved_word(o_string *word, struct parse_context *ctx)
3237 # if ENABLE_HUSH_CASE
3238 static const struct reserved_combo reserved_match = {
3239 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3242 const struct reserved_combo *r;
3244 if (word->has_quoted_part)
3246 r = match_reserved_word(word);
3250 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3251 # if ENABLE_HUSH_CASE
3252 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3253 /* "case word IN ..." - IN part starts first MATCH part */
3254 r = &reserved_match;
3257 if (r->flag == 0) { /* '!' */
3258 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3259 syntax_error("! ! command");
3260 ctx->ctx_res_w = RES_SNTX;
3262 ctx->ctx_inverted = 1;
3265 if (r->flag & FLAG_START) {
3266 struct parse_context *old;
3268 old = xmalloc(sizeof(*old));
3269 debug_printf_parse("push stack %p\n", old);
3270 *old = *ctx; /* physical copy */
3271 initialize_context(ctx);
3273 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3274 syntax_error_at(word->data);
3275 ctx->ctx_res_w = RES_SNTX;
3278 /* "{...} fi" is ok. "{...} if" is not
3280 * if { echo foo; } then { echo bar; } fi */
3281 if (ctx->command->group)
3282 done_pipe(ctx, PIPE_SEQ);
3285 ctx->ctx_res_w = r->res;
3286 ctx->old_flag = r->flag;
3287 word->o_assignment = r->assignment_flag;
3288 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3290 if (ctx->old_flag & FLAG_END) {
3291 struct parse_context *old;
3293 done_pipe(ctx, PIPE_SEQ);
3294 debug_printf_parse("pop stack %p\n", ctx->stack);
3296 old->command->group = ctx->list_head;
3297 old->command->cmd_type = CMD_NORMAL;
3299 /* At this point, the compound command's string is in
3300 * ctx->as_string... except for the leading keyword!
3301 * Consider this example: "echo a | if true; then echo a; fi"
3302 * ctx->as_string will contain "true; then echo a; fi",
3303 * with "if " remaining in old->as_string!
3307 int len = old->as_string.length;
3308 /* Concatenate halves */
3309 o_addstr(&old->as_string, ctx->as_string.data);
3310 o_free_unsafe(&ctx->as_string);
3311 /* Find where leading keyword starts in first half */
3312 str = old->as_string.data + len;
3313 if (str > old->as_string.data)
3314 str--; /* skip whitespace after keyword */
3315 while (str > old->as_string.data && isalpha(str[-1]))
3317 /* Ugh, we're done with this horrid hack */
3318 old->command->group_as_string = xstrdup(str);
3319 debug_printf_parse("pop, remembering as:'%s'\n",
3320 old->command->group_as_string);
3323 *ctx = *old; /* physical copy */
3328 #endif /* HAS_KEYWORDS */
3330 /* Word is complete, look at it and update parsing context.
3331 * Normal return is 0. Syntax errors return 1.
3332 * Note: on return, word is reset, but not o_free'd!
3334 static int done_word(o_string *word, struct parse_context *ctx)
3336 struct command *command = ctx->command;
3338 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3339 if (word->length == 0 && !word->has_quoted_part) {
3340 debug_printf_parse("done_word return 0: true null, ignored\n");
3344 if (ctx->pending_redirect) {
3345 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3346 * only if run as "bash", not "sh" */
3347 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3349 * ...the word that follows the redirection operator
3350 * shall be subjected to tilde expansion, parameter expansion,
3351 * command substitution, arithmetic expansion, and quote
3352 * removal. Pathname expansion shall not be performed
3353 * on the word by a non-interactive shell; an interactive
3354 * shell may perform it, but shall do so only when
3355 * the expansion would result in one word."
3357 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3358 /* Cater for >\file case:
3359 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3360 * Same with heredocs:
3361 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3363 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3364 unbackslash(ctx->pending_redirect->rd_filename);
3365 /* Is it <<"HEREDOC"? */
3366 if (word->has_quoted_part) {
3367 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3370 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3371 ctx->pending_redirect = NULL;
3374 # if ENABLE_HUSH_CASE
3375 if (ctx->ctx_dsemicolon
3376 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3378 /* already done when ctx_dsemicolon was set to 1: */
3379 /* ctx->ctx_res_w = RES_MATCH; */
3380 ctx->ctx_dsemicolon = 0;
3383 if (!command->argv /* if it's the first word... */
3384 # if ENABLE_HUSH_LOOPS
3385 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3386 && ctx->ctx_res_w != RES_IN
3388 # if ENABLE_HUSH_CASE
3389 && ctx->ctx_res_w != RES_CASE
3392 int reserved = reserved_word(word, ctx);
3393 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3395 o_reset_to_empty_unquoted(word);
3396 debug_printf_parse("done_word return %d\n",
3397 (ctx->ctx_res_w == RES_SNTX));
3398 return (ctx->ctx_res_w == RES_SNTX);
3400 # if ENABLE_HUSH_BASH_COMPAT
3401 if (strcmp(word->data, "[[") == 0) {
3402 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3408 if (command->group) {
3409 /* "{ echo foo; } echo bar" - bad */
3410 syntax_error_at(word->data);
3411 debug_printf_parse("done_word return 1: syntax error, "
3412 "groups and arglists don't mix\n");
3416 /* If this word wasn't an assignment, next ones definitely
3417 * can't be assignments. Even if they look like ones. */
3418 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3419 && word->o_assignment != WORD_IS_KEYWORD
3421 word->o_assignment = NOT_ASSIGNMENT;
3423 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3424 command->assignment_cnt++;
3425 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3427 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3428 word->o_assignment = MAYBE_ASSIGNMENT;
3430 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3432 if (word->has_quoted_part
3433 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3434 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3435 /* (otherwise it's known to be not empty and is already safe) */
3437 /* exclude "$@" - it can expand to no word despite "" */
3438 char *p = word->data;
3439 while (p[0] == SPECIAL_VAR_SYMBOL
3440 && (p[1] & 0x7f) == '@'
3441 && p[2] == SPECIAL_VAR_SYMBOL
3446 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3447 debug_print_strings("word appended to argv", command->argv);
3450 #if ENABLE_HUSH_LOOPS
3451 if (ctx->ctx_res_w == RES_FOR) {
3452 if (word->has_quoted_part
3453 || !is_well_formed_var_name(command->argv[0], '\0')
3455 /* bash says just "not a valid identifier" */
3456 syntax_error("not a valid identifier in for");
3459 /* Force FOR to have just one word (variable name) */
3460 /* NB: basically, this makes hush see "for v in ..."
3461 * syntax as if it is "for v; in ...". FOR and IN become
3462 * two pipe structs in parse tree. */
3463 done_pipe(ctx, PIPE_SEQ);
3466 #if ENABLE_HUSH_CASE
3467 /* Force CASE to have just one word */
3468 if (ctx->ctx_res_w == RES_CASE) {
3469 done_pipe(ctx, PIPE_SEQ);
3473 o_reset_to_empty_unquoted(word);
3475 debug_printf_parse("done_word return 0\n");
3480 /* Peek ahead in the input to find out if we have a "&n" construct,
3481 * as in "2>&1", that represents duplicating a file descriptor.
3483 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3484 * REDIRFD_SYNTAX_ERR if syntax error,
3485 * REDIRFD_TO_FILE if no & was seen,
3486 * or the number found.
3489 #define parse_redir_right_fd(as_string, input) \
3490 parse_redir_right_fd(input)
3492 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3498 return REDIRFD_TO_FILE;
3500 ch = i_getch(input); /* get the & */
3501 nommu_addchr(as_string, ch);
3504 ch = i_getch(input);
3505 nommu_addchr(as_string, ch);
3506 return REDIRFD_CLOSE;
3510 while (ch != EOF && isdigit(ch)) {
3511 d = d*10 + (ch-'0');
3513 ch = i_getch(input);
3514 nommu_addchr(as_string, ch);
3519 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3521 bb_error_msg("ambiguous redirect");
3522 return REDIRFD_SYNTAX_ERR;
3525 /* Return code is 0 normal, 1 if a syntax error is detected
3527 static int parse_redirect(struct parse_context *ctx,
3530 struct in_str *input)
3532 struct command *command = ctx->command;
3533 struct redir_struct *redir;
3534 struct redir_struct **redirp;
3537 dup_num = REDIRFD_TO_FILE;
3538 if (style != REDIRECT_HEREDOC) {
3539 /* Check for a '>&1' type redirect */
3540 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3541 if (dup_num == REDIRFD_SYNTAX_ERR)
3544 int ch = i_peek(input);
3545 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3546 if (dup_num) { /* <<-... */
3547 ch = i_getch(input);
3548 nommu_addchr(&ctx->as_string, ch);
3553 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3554 int ch = i_peek(input);
3556 /* >|FILE redirect ("clobbering" >).
3557 * Since we do not support "set -o noclobber" yet,
3558 * >| and > are the same for now. Just eat |.
3560 ch = i_getch(input);
3561 nommu_addchr(&ctx->as_string, ch);
3565 /* Create a new redir_struct and append it to the linked list */
3566 redirp = &command->redirects;
3567 while ((redir = *redirp) != NULL) {
3568 redirp = &(redir->next);
3570 *redirp = redir = xzalloc(sizeof(*redir));
3571 /* redir->next = NULL; */
3572 /* redir->rd_filename = NULL; */
3573 redir->rd_type = style;
3574 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3576 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3577 redir_table[style].descrip);
3579 redir->rd_dup = dup_num;
3580 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3581 /* Erik had a check here that the file descriptor in question
3582 * is legit; I postpone that to "run time"
3583 * A "-" representation of "close me" shows up as a -3 here */
3584 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3585 redir->rd_fd, redir->rd_dup);
3587 #if 0 /* Instead we emit error message at run time */
3588 if (ctx->pending_redirect) {
3589 /* For example, "cmd > <file" */
3590 die_if_script("syntax error: %s", "invalid redirect");
3593 /* Set ctx->pending_redirect, so we know what to do at the
3594 * end of the next parsed word. */
3595 ctx->pending_redirect = redir;
3600 /* If a redirect is immediately preceded by a number, that number is
3601 * supposed to tell which file descriptor to redirect. This routine
3602 * looks for such preceding numbers. In an ideal world this routine
3603 * needs to handle all the following classes of redirects...
3604 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3605 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3606 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3607 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3609 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3611 * ... If n is quoted, the number shall not be recognized as part of
3612 * the redirection expression. For example:
3614 * writes the character 2 into file a"
3615 * We are getting it right by setting ->has_quoted_part on any \<char>
3617 * A -1 return means no valid number was found,
3618 * the caller should use the appropriate default for this redirection.
3620 static int redirect_opt_num(o_string *o)
3624 if (o->data == NULL)
3626 num = bb_strtou(o->data, NULL, 10);
3627 if (errno || num < 0)
3629 o_reset_to_empty_unquoted(o);
3634 #define fetch_till_str(as_string, input, word, skip_tabs) \
3635 fetch_till_str(input, word, skip_tabs)
3637 static char *fetch_till_str(o_string *as_string,
3638 struct in_str *input,
3642 o_string heredoc = NULL_O_STRING;
3644 int prev = 0; /* not \ */
3650 ch = i_getch(input);
3652 nommu_addchr(as_string, ch);
3653 if ((ch == '\n' || ch == EOF)
3654 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3656 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3657 heredoc.data[past_EOL] = '\0';
3658 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3659 return heredoc.data;
3661 while (ch == '\n') {
3662 o_addchr(&heredoc, ch);
3665 past_EOL = heredoc.length;
3667 ch = i_getch(input);
3669 nommu_addchr(as_string, ch);
3670 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3674 o_free_unsafe(&heredoc);
3677 o_addchr(&heredoc, ch);
3678 nommu_addchr(as_string, ch);
3679 if (prev == '\\' && ch == '\\')
3680 /* Correctly handle foo\\<eol> (not a line cont.) */
3681 prev = 0; /* not \ */
3687 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3688 * and load them all. There should be exactly heredoc_cnt of them.
3690 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3692 struct pipe *pi = ctx->list_head;
3694 while (pi && heredoc_cnt) {
3696 struct command *cmd = pi->cmds;
3698 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3700 cmd->argv ? cmd->argv[0] : "NONE");
3701 for (i = 0; i < pi->num_cmds; i++) {
3702 struct redir_struct *redir = cmd->redirects;
3704 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3705 i, cmd->argv ? cmd->argv[0] : "NONE");
3707 if (redir->rd_type == REDIRECT_HEREDOC) {
3710 redir->rd_type = REDIRECT_HEREDOC2;
3711 /* redir->rd_dup is (ab)used to indicate <<- */
3712 p = fetch_till_str(&ctx->as_string, input,
3713 redir->rd_filename, redir->rd_dup);
3715 syntax_error("unexpected EOF in here document");
3718 free(redir->rd_filename);
3719 redir->rd_filename = p;
3722 redir = redir->next;
3729 /* Should be 0. If it isn't, it's a parse error */
3731 bb_error_msg_and_die("heredoc BUG 2");
3737 static int run_list(struct pipe *pi);
3739 #define parse_stream(pstring, input, end_trigger) \
3740 parse_stream(input, end_trigger)
3742 static struct pipe *parse_stream(char **pstring,
3743 struct in_str *input,
3747 #if !ENABLE_HUSH_FUNCTIONS
3748 #define parse_group(dest, ctx, input, ch) \
3749 parse_group(ctx, input, ch)
3751 static int parse_group(o_string *dest, struct parse_context *ctx,
3752 struct in_str *input, int ch)
3754 /* dest contains characters seen prior to ( or {.
3755 * Typically it's empty, but for function defs,
3756 * it contains function name (without '()'). */
3757 struct pipe *pipe_list;
3759 struct command *command = ctx->command;
3761 debug_printf_parse("parse_group entered\n");
3762 #if ENABLE_HUSH_FUNCTIONS
3763 if (ch == '(' && !dest->has_quoted_part) {
3765 if (done_word(dest, ctx))
3768 goto skip; /* (... */
3769 if (command->argv[1]) { /* word word ... (... */
3770 syntax_error_unexpected_ch('(');
3773 /* it is "word(..." or "word (..." */
3775 ch = i_getch(input);
3776 while (ch == ' ' || ch == '\t');
3778 syntax_error_unexpected_ch(ch);
3781 nommu_addchr(&ctx->as_string, ch);
3783 ch = i_getch(input);
3784 while (ch == ' ' || ch == '\t' || ch == '\n');
3786 syntax_error_unexpected_ch(ch);
3789 nommu_addchr(&ctx->as_string, ch);
3790 command->cmd_type = CMD_FUNCDEF;
3795 #if 0 /* Prevented by caller */
3796 if (command->argv /* word [word]{... */
3797 || dest->length /* word{... */
3798 || dest->has_quoted_part /* ""{... */
3801 debug_printf_parse("parse_group return 1: "
3802 "syntax error, groups and arglists don't mix\n");
3807 #if ENABLE_HUSH_FUNCTIONS
3813 command->cmd_type = CMD_SUBSHELL;
3815 /* bash does not allow "{echo...", requires whitespace */
3816 ch = i_getch(input);
3817 if (ch != ' ' && ch != '\t' && ch != '\n') {
3818 syntax_error_unexpected_ch(ch);
3821 nommu_addchr(&ctx->as_string, ch);
3826 # define as_string NULL
3828 char *as_string = NULL;
3830 pipe_list = parse_stream(&as_string, input, endch);
3833 o_addstr(&ctx->as_string, as_string);
3835 /* empty ()/{} or parse error? */
3836 if (!pipe_list || pipe_list == ERR_PTR) {
3837 /* parse_stream already emitted error msg */
3840 debug_printf_parse("parse_group return 1: "
3841 "parse_stream returned %p\n", pipe_list);
3844 command->group = pipe_list;
3846 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3847 command->group_as_string = as_string;
3848 debug_printf_parse("end of group, remembering as:'%s'\n",
3849 command->group_as_string);
3853 debug_printf_parse("parse_group return 0\n");
3855 /* command remains "open", available for possible redirects */
3858 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3859 /* Subroutines for copying $(...) and `...` things */
3860 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3862 static int add_till_single_quote(o_string *dest, struct in_str *input)
3865 int ch = i_getch(input);
3867 syntax_error_unterm_ch('\'');
3875 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3876 static int add_till_double_quote(o_string *dest, struct in_str *input)
3879 int ch = i_getch(input);
3881 syntax_error_unterm_ch('"');
3886 if (ch == '\\') { /* \x. Copy both chars. */
3888 ch = i_getch(input);
3892 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
3897 //if (ch == '$') ...
3900 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3902 * "Within the backquoted style of command substitution, backslash
3903 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3904 * The search for the matching backquote shall be satisfied by the first
3905 * backquote found without a preceding backslash; during this search,
3906 * if a non-escaped backquote is encountered within a shell comment,
3907 * a here-document, an embedded command substitution of the $(command)
3908 * form, or a quoted string, undefined results occur. A single-quoted
3909 * or double-quoted string that begins, but does not end, within the
3910 * "`...`" sequence produces undefined results."
3912 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3914 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3917 int ch = i_getch(input);
3921 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3922 ch = i_getch(input);
3926 && (!in_dquote || ch != '"')
3928 o_addchr(dest, '\\');
3932 syntax_error_unterm_ch('`');
3938 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3939 * quoting and nested ()s.
3940 * "With the $(command) style of command substitution, all characters
3941 * following the open parenthesis to the matching closing parenthesis
3942 * constitute the command. Any valid shell script can be used for command,
3943 * except a script consisting solely of redirections which produces
3944 * unspecified results."
3946 * echo $(echo '(TEST)' BEST) (TEST) BEST
3947 * echo $(echo 'TEST)' BEST) TEST) BEST
3948 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3950 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3951 * can contain arbitrary constructs, just like $(cmd).
3952 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3953 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3955 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3956 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3959 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3960 # if ENABLE_HUSH_BASH_COMPAT
3961 char end_char2 = end_ch >> 8;
3963 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3966 ch = i_getch(input);
3968 syntax_error_unterm_ch(end_ch);
3971 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3974 /* we look for closing )) of $((EXPR)) */
3975 if (i_peek(input) == end_ch) {
3976 i_getch(input); /* eat second ')' */
3981 if (ch == '(' || ch == '{') {
3982 ch = (ch == '(' ? ')' : '}');
3983 if (!add_till_closing_bracket(dest, input, ch))
3989 if (!add_till_single_quote(dest, input))
3995 if (!add_till_double_quote(dest, input))
4001 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4007 /* \x. Copy verbatim. Important for \(, \) */
4008 ch = i_getch(input);
4010 syntax_error_unterm_ch(')');
4019 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
4021 /* Return code: 0 for OK, 1 for syntax error */
4023 #define parse_dollar(as_string, dest, input, quote_mask) \
4024 parse_dollar(dest, input, quote_mask)
4025 #define as_string NULL
4027 static int parse_dollar(o_string *as_string,
4029 struct in_str *input, unsigned char quote_mask)
4031 int ch = i_peek(input); /* first character after the $ */
4033 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4035 ch = i_getch(input);
4036 nommu_addchr(as_string, ch);
4038 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4040 debug_printf_parse(": '%c'\n", ch);
4041 o_addchr(dest, ch | quote_mask);
4044 if (!isalnum(ch) && ch != '_')
4046 ch = i_getch(input);
4047 nommu_addchr(as_string, ch);
4049 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4050 } else if (isdigit(ch)) {
4052 ch = i_getch(input);
4053 nommu_addchr(as_string, ch);
4054 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4055 debug_printf_parse(": '%c'\n", ch);
4056 o_addchr(dest, ch | quote_mask);
4057 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4058 } else switch (ch) {
4060 case '!': /* last bg pid */
4061 case '?': /* last exit code */
4062 case '#': /* number of args */
4063 case '*': /* args */
4064 case '@': /* args */
4065 goto make_one_char_var;
4067 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4069 ch = i_getch(input); /* eat '{' */
4070 nommu_addchr(as_string, ch);
4072 ch = i_getch(input); /* first char after '{' */
4073 /* It should be ${?}, or ${#var},
4074 * or even ${?+subst} - operator acting on a special variable,
4075 * or the beginning of variable name.
4078 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4081 syntax_error_unterm_str("${name}");
4082 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4085 nommu_addchr(as_string, ch);
4088 /* It's possible to just call add_till_closing_bracket() at this point.
4089 * However, this regresses some of our testsuite cases
4090 * which check invalid constructs like ${%}.
4091 * Oh well... let's check that the var name part is fine... */
4097 debug_printf_parse(": '%c'\n", ch);
4099 ch = i_getch(input);
4100 nommu_addchr(as_string, ch);
4104 if (!isalnum(ch) && ch != '_') {
4106 unsigned char last_ch;
4107 /* handle parameter expansions
4108 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4110 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4111 goto bad_dollar_syntax;
4113 /* Eat everything until closing '}' (or ':') */
4115 if (ENABLE_HUSH_BASH_COMPAT
4117 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4119 /* It's ${var:N[:M]} thing */
4120 end_ch = '}' * 0x100 + ':';
4122 if (ENABLE_HUSH_BASH_COMPAT
4125 /* It's ${var/[/]pattern[/repl]} thing */
4126 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4128 nommu_addchr(as_string, '/');
4131 end_ch = '}' * 0x100 + '/';
4137 #if ENABLE_HUSH_DOLLAR_OPS
4138 last_ch = add_till_closing_bracket(dest, input, end_ch);
4139 if (last_ch == 0) /* error? */
4142 #error Simple code to only allow ${var} is not implemented
4145 o_addstr(as_string, dest->data + pos);
4146 o_addchr(as_string, last_ch);
4149 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4150 /* close the first block: */
4151 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4152 /* while parsing N from ${var:N[:M]}
4153 * or pattern from ${var/[/]pattern[/repl]} */
4154 if ((end_ch & 0xff) == last_ch) {
4155 /* got ':' or '/'- parse the rest */
4160 if (end_ch == '}' * 0x100 + ':') {
4161 /* it's ${var:N} - emulate :999999999 */
4162 o_addstr(dest, "999999999");
4163 } /* else: it's ${var/[/]pattern} */
4168 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4171 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4175 ch = i_getch(input);
4176 nommu_addchr(as_string, ch);
4177 # if ENABLE_SH_MATH_SUPPORT
4178 if (i_peek(input) == '(') {
4179 ch = i_getch(input);
4180 nommu_addchr(as_string, ch);
4181 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4182 o_addchr(dest, /*quote_mask |*/ '+');
4185 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4186 return 0; /* error */
4188 o_addstr(as_string, dest->data + pos);
4189 o_addchr(as_string, ')');
4190 o_addchr(as_string, ')');
4192 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4196 # if ENABLE_HUSH_TICK
4197 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4198 o_addchr(dest, quote_mask | '`');
4201 if (!add_till_closing_bracket(dest, input, ')'))
4202 return 0; /* error */
4204 o_addstr(as_string, dest->data + pos);
4205 o_addchr(as_string, ')');
4207 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4213 ch = i_getch(input);
4214 nommu_addchr(as_string, ch);
4216 if (isalnum(ch)) { /* it's $_name or $_123 */
4221 /* TODO: $_ and $-: */
4222 /* $_ Shell or shell script name; or last argument of last command
4223 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4224 * but in command's env, set to full pathname used to invoke it */
4225 /* $- Option flags set by set builtin or shell options (-i etc) */
4227 o_addQchr(dest, '$');
4229 debug_printf_parse("parse_dollar return 1 (ok)\n");
4235 # if ENABLE_HUSH_BASH_COMPAT
4236 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4237 encode_string(dest, input, dquote_end, process_bkslash)
4239 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4240 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4241 encode_string(dest, input, dquote_end)
4243 #define as_string NULL
4247 # if ENABLE_HUSH_BASH_COMPAT
4248 /* all parameters are needed, no macro tricks */
4250 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4251 encode_string(as_string, dest, input, dquote_end)
4254 static int encode_string(o_string *as_string,
4256 struct in_str *input,
4258 int process_bkslash)
4260 #if !ENABLE_HUSH_BASH_COMPAT
4261 const int process_bkslash = 1;
4267 ch = i_getch(input);
4269 nommu_addchr(as_string, ch);
4270 if (ch == dquote_end) { /* may be only '"' or EOF */
4271 debug_printf_parse("encode_string return 1 (ok)\n");
4274 /* note: can't move it above ch == dquote_end check! */
4276 syntax_error_unterm_ch('"');
4277 return 0; /* error */
4281 next = i_peek(input);
4283 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4284 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4285 if (process_bkslash && ch == '\\') {
4287 syntax_error("\\<eof>");
4291 * "The backslash retains its special meaning [in "..."]
4292 * only when followed by one of the following characters:
4293 * $, `, ", \, or <newline>. A double quote may be quoted
4294 * within double quotes by preceding it with a backslash."
4295 * NB: in (unquoted) heredoc, above does not apply to ",
4296 * therefore we check for it by "next == dquote_end" cond.
4298 if (next == dquote_end || strchr("$`\\\n", next)) {
4299 ch = i_getch(input); /* eat next */
4301 goto again; /* skip \<newline> */
4302 } /* else: ch remains == '\\', and we double it below: */
4303 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4304 nommu_addchr(as_string, ch);
4308 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4309 debug_printf_parse("encode_string return 0: "
4310 "parse_dollar returned 0 (error)\n");
4315 #if ENABLE_HUSH_TICK
4317 //unsigned pos = dest->length;
4318 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4319 o_addchr(dest, 0x80 | '`');
4320 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4321 return 0; /* error */
4322 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4323 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4327 o_addQchr(dest, ch);
4333 * Scan input until EOF or end_trigger char.
4334 * Return a list of pipes to execute, or NULL on EOF
4335 * or if end_trigger character is met.
4336 * On syntax error, exit if shell is not interactive,
4337 * reset parsing machinery and start parsing anew,
4338 * or return ERR_PTR.
4340 static struct pipe *parse_stream(char **pstring,
4341 struct in_str *input,
4344 struct parse_context ctx;
4345 o_string dest = NULL_O_STRING;
4348 /* Single-quote triggers a bypass of the main loop until its mate is
4349 * found. When recursing, quote state is passed in via dest->o_expflags.
4351 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4352 end_trigger ? end_trigger : 'X');
4355 /* If very first arg is "" or '', dest.data may end up NULL.
4356 * Preventing this: */
4357 o_addchr(&dest, '\0');
4360 /* We used to separate words on $IFS here. This was wrong.
4361 * $IFS is used only for word splitting when $var is expanded,
4362 * here we should use blank chars as separators, not $IFS
4365 if (MAYBE_ASSIGNMENT != 0)
4366 dest.o_assignment = MAYBE_ASSIGNMENT;
4367 initialize_context(&ctx);
4370 const char *is_blank;
4371 const char *is_special;
4375 redir_type redir_style;
4377 ch = i_getch(input);
4378 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4379 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4384 syntax_error_unterm_str("here document");
4387 /* end_trigger == '}' case errors out earlier,
4388 * checking only ')' */
4389 if (end_trigger == ')') {
4390 syntax_error_unterm_ch('(');
4394 if (done_word(&dest, &ctx)) {
4398 done_pipe(&ctx, PIPE_SEQ);
4400 /* If we got nothing... */
4401 /* (this makes bare "&" cmd a no-op.
4402 * bash says: "syntax error near unexpected token '&'") */
4403 if (pi->num_cmds == 0
4404 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4410 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4412 *pstring = ctx.as_string.data;
4414 o_free_unsafe(&ctx.as_string);
4417 debug_printf_parse("parse_stream return %p\n", pi);
4420 nommu_addchr(&ctx.as_string, ch);
4424 next = i_peek(input);
4426 is_special = "{}<>;&|()#'" /* special outside of "str" */
4427 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4428 /* Are { and } special here? */
4429 if (ctx.command->argv /* word [word]{... - non-special */
4430 || dest.length /* word{... - non-special */
4431 || dest.has_quoted_part /* ""{... - non-special */
4432 || (next != ';' /* }; - special */
4433 && next != ')' /* }) - special */
4434 && next != '&' /* }& and }&& ... - special */
4435 && next != '|' /* }|| ... - special */
4436 && !strchr(defifs, next) /* {word - non-special */
4439 /* They are not special, skip "{}" */
4442 is_special = strchr(is_special, ch);
4443 is_blank = strchr(defifs, ch);
4445 if (!is_special && !is_blank) { /* ordinary char */
4447 o_addQchr(&dest, ch);
4448 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4449 || dest.o_assignment == WORD_IS_KEYWORD)
4451 && is_well_formed_var_name(dest.data, '=')
4453 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4454 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4460 if (done_word(&dest, &ctx)) {
4464 /* Is this a case when newline is simply ignored?
4466 * "cmd | <newline> cmd ..."
4467 * "case ... in <newline> word) ..."
4469 if (IS_NULL_CMD(ctx.command)
4470 && dest.length == 0 && !dest.has_quoted_part
4472 /* This newline can be ignored. But...
4473 * Without check #1, interactive shell
4474 * ignores even bare <newline>,
4475 * and shows the continuation prompt:
4476 * ps1_prompt$ <enter>
4477 * ps2> _ <=== wrong, should be ps1
4478 * Without check #2, "cmd & <newline>"
4479 * is similarly mistreated.
4480 * (BTW, this makes "cmd & cmd"
4481 * and "cmd && cmd" non-orthogonal.
4482 * Really, ask yourself, why
4483 * "cmd && <newline>" doesn't start
4484 * cmd but waits for more input?
4487 struct pipe *pi = ctx.list_head;
4488 if (pi->num_cmds != 0 /* check #1 */
4489 && pi->followup != PIPE_BG /* check #2 */
4494 /* Treat newline as a command separator. */
4495 done_pipe(&ctx, PIPE_SEQ);
4496 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4498 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4503 dest.o_assignment = MAYBE_ASSIGNMENT;
4504 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4506 /* note: if (is_blank) continue;
4507 * will still trigger for us */
4511 /* "cmd}" or "cmd }..." without semicolon or &:
4512 * } is an ordinary char in this case, even inside { cmd; }
4513 * Pathological example: { ""}; } should exec "}" cmd
4516 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4517 || dest.length != 0 /* word} */
4518 || dest.has_quoted_part /* ""} */
4522 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4523 goto skip_end_trigger;
4524 /* else: } does terminate a group */
4527 if (end_trigger && end_trigger == ch
4528 && (ch != ';' || heredoc_cnt == 0)
4529 #if ENABLE_HUSH_CASE
4531 || ctx.ctx_res_w != RES_MATCH
4532 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4537 /* This is technically valid:
4538 * { cat <<HERE; }; echo Ok
4542 * but we don't support this.
4543 * We require heredoc to be in enclosing {}/(),
4546 syntax_error_unterm_str("here document");
4549 if (done_word(&dest, &ctx)) {
4552 done_pipe(&ctx, PIPE_SEQ);
4553 dest.o_assignment = MAYBE_ASSIGNMENT;
4554 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4555 /* Do we sit outside of any if's, loops or case's? */
4557 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4561 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4563 *pstring = ctx.as_string.data;
4565 o_free_unsafe(&ctx.as_string);
4568 debug_printf_parse("parse_stream return %p: "
4569 "end_trigger char found\n",
4571 return ctx.list_head;
4578 /* Catch <, > before deciding whether this word is
4579 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4582 redir_fd = redirect_opt_num(&dest);
4583 if (done_word(&dest, &ctx)) {
4586 redir_style = REDIRECT_OVERWRITE;
4588 redir_style = REDIRECT_APPEND;
4589 ch = i_getch(input);
4590 nommu_addchr(&ctx.as_string, ch);
4593 else if (next == '(') {
4594 syntax_error(">(process) not supported");
4598 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4600 continue; /* back to top of while (1) */
4602 redir_fd = redirect_opt_num(&dest);
4603 if (done_word(&dest, &ctx)) {
4606 redir_style = REDIRECT_INPUT;
4608 redir_style = REDIRECT_HEREDOC;
4610 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4611 ch = i_getch(input);
4612 nommu_addchr(&ctx.as_string, ch);
4613 } else if (next == '>') {
4614 redir_style = REDIRECT_IO;
4615 ch = i_getch(input);
4616 nommu_addchr(&ctx.as_string, ch);
4619 else if (next == '(') {
4620 syntax_error("<(process) not supported");
4624 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4626 continue; /* back to top of while (1) */
4628 if (dest.length == 0 && !dest.has_quoted_part) {
4629 /* skip "#comment" */
4632 if (ch == EOF || ch == '\n')
4635 /* note: we do not add it to &ctx.as_string */
4637 nommu_addchr(&ctx.as_string, '\n');
4638 continue; /* back to top of while (1) */
4643 /* It's "\<newline>" */
4645 /* Remove trailing '\' from ctx.as_string */
4646 ctx.as_string.data[--ctx.as_string.length] = '\0';
4648 ch = i_getch(input); /* eat it */
4649 continue; /* back to top of while (1) */
4654 if (dest.o_assignment == MAYBE_ASSIGNMENT
4655 /* check that we are not in word in "a=1 2>word b=1": */
4656 && !ctx.pending_redirect
4658 /* ch is a special char and thus this word
4659 * cannot be an assignment */
4660 dest.o_assignment = NOT_ASSIGNMENT;
4661 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4664 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4667 case '#': /* non-comment #: "echo a#b" etc */
4668 o_addQchr(&dest, ch);
4672 syntax_error("\\<eof>");
4675 ch = i_getch(input);
4676 /* note: ch != '\n' (that case does not reach this place) */
4677 o_addchr(&dest, '\\');
4678 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4679 o_addchr(&dest, ch);
4680 nommu_addchr(&ctx.as_string, ch);
4681 /* Example: echo Hello \2>file
4682 * we need to know that word 2 is quoted */
4683 dest.has_quoted_part = 1;
4686 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4687 debug_printf_parse("parse_stream parse error: "
4688 "parse_dollar returned 0 (error)\n");
4693 dest.has_quoted_part = 1;
4694 if (next == '\'' && !ctx.pending_redirect) {
4695 insert_empty_quoted_str_marker:
4696 nommu_addchr(&ctx.as_string, next);
4697 i_getch(input); /* eat second ' */
4698 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4699 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4702 ch = i_getch(input);
4704 syntax_error_unterm_ch('\'');
4707 nommu_addchr(&ctx.as_string, ch);
4710 o_addqchr(&dest, ch);
4715 dest.has_quoted_part = 1;
4716 if (next == '"' && !ctx.pending_redirect)
4717 goto insert_empty_quoted_str_marker;
4718 if (dest.o_assignment == NOT_ASSIGNMENT)
4719 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4720 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4722 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4724 #if ENABLE_HUSH_TICK
4726 USE_FOR_NOMMU(unsigned pos;)
4728 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4729 o_addchr(&dest, '`');
4730 USE_FOR_NOMMU(pos = dest.length;)
4731 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4734 o_addstr(&ctx.as_string, dest.data + pos);
4735 o_addchr(&ctx.as_string, '`');
4737 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4738 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4743 #if ENABLE_HUSH_CASE
4746 if (done_word(&dest, &ctx)) {
4749 done_pipe(&ctx, PIPE_SEQ);
4750 #if ENABLE_HUSH_CASE
4751 /* Eat multiple semicolons, detect
4752 * whether it means something special */
4757 ch = i_getch(input);
4758 nommu_addchr(&ctx.as_string, ch);
4759 if (ctx.ctx_res_w == RES_CASE_BODY) {
4760 ctx.ctx_dsemicolon = 1;
4761 ctx.ctx_res_w = RES_MATCH;
4767 /* We just finished a cmd. New one may start
4768 * with an assignment */
4769 dest.o_assignment = MAYBE_ASSIGNMENT;
4770 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4773 if (done_word(&dest, &ctx)) {
4777 ch = i_getch(input);
4778 nommu_addchr(&ctx.as_string, ch);
4779 done_pipe(&ctx, PIPE_AND);
4781 done_pipe(&ctx, PIPE_BG);
4785 if (done_word(&dest, &ctx)) {
4788 #if ENABLE_HUSH_CASE
4789 if (ctx.ctx_res_w == RES_MATCH)
4790 break; /* we are in case's "word | word)" */
4792 if (next == '|') { /* || */
4793 ch = i_getch(input);
4794 nommu_addchr(&ctx.as_string, ch);
4795 done_pipe(&ctx, PIPE_OR);
4797 /* we could pick up a file descriptor choice here
4798 * with redirect_opt_num(), but bash doesn't do it.
4799 * "echo foo 2| cat" yields "foo 2". */
4804 #if ENABLE_HUSH_CASE
4805 /* "case... in [(]word)..." - skip '(' */
4806 if (ctx.ctx_res_w == RES_MATCH
4807 && ctx.command->argv == NULL /* not (word|(... */
4808 && dest.length == 0 /* not word(... */
4809 && dest.has_quoted_part == 0 /* not ""(... */
4815 if (parse_group(&dest, &ctx, input, ch) != 0) {
4820 #if ENABLE_HUSH_CASE
4821 if (ctx.ctx_res_w == RES_MATCH)
4825 /* proper use of this character is caught by end_trigger:
4826 * if we see {, we call parse_group(..., end_trigger='}')
4827 * and it will match } earlier (not here). */
4828 syntax_error_unexpected_ch(ch);
4832 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4838 struct parse_context *pctx;
4839 IF_HAS_KEYWORDS(struct parse_context *p2;)
4841 /* Clean up allocated tree.
4842 * Sample for finding leaks on syntax error recovery path.
4843 * Run it from interactive shell, watch pmap `pidof hush`.
4844 * while if false; then false; fi; do break; fi
4845 * Samples to catch leaks at execution:
4846 * while if (true | {true;}); then echo ok; fi; do break; done
4847 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4851 /* Update pipe/command counts,
4852 * otherwise freeing may miss some */
4853 done_pipe(pctx, PIPE_SEQ);
4854 debug_printf_clean("freeing list %p from ctx %p\n",
4855 pctx->list_head, pctx);
4856 debug_print_tree(pctx->list_head, 0);
4857 free_pipe_list(pctx->list_head);
4858 debug_printf_clean("freed list %p\n", pctx->list_head);
4860 o_free_unsafe(&pctx->as_string);
4862 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4866 IF_HAS_KEYWORDS(pctx = p2;)
4867 } while (HAS_KEYWORDS && pctx);
4870 G.last_exitcode = 1;
4881 /*** Execution routines ***/
4883 /* Expansion can recurse, need forward decls: */
4884 #if !ENABLE_HUSH_BASH_COMPAT
4885 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4886 #define expand_string_to_string(str, do_unbackslash) \
4887 expand_string_to_string(str)
4889 static char *expand_string_to_string(const char *str, int do_unbackslash);
4890 #if ENABLE_HUSH_TICK
4891 static int process_command_subs(o_string *dest, const char *s);
4894 /* expand_strvec_to_strvec() takes a list of strings, expands
4895 * all variable references within and returns a pointer to
4896 * a list of expanded strings, possibly with larger number
4897 * of strings. (Think VAR="a b"; echo $VAR).
4898 * This new list is allocated as a single malloc block.
4899 * NULL-terminated list of char* pointers is at the beginning of it,
4900 * followed by strings themselves.
4901 * Caller can deallocate entire list by single free(list). */
4903 /* A horde of its helpers come first: */
4905 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
4907 while (--len >= 0) {
4910 #if ENABLE_HUSH_BRACE_EXPANSION
4911 if (c == '{' || c == '}') {
4912 /* { -> \{, } -> \} */
4914 /* And now we want to add { or } and continue:
4917 * luckily, just falling throught achieves this.
4923 /* \z -> \\\z; \<eol> -> \\<eol> */
4928 o_addchr(o, *str++);
4934 /* Store given string, finalizing the word and starting new one whenever
4935 * we encounter IFS char(s). This is used for expanding variable values.
4936 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
4937 * Return in *ended_with_ifs:
4938 * 1 - ended with IFS char, else 0 (this includes case of empty str).
4940 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
4942 int last_is_ifs = 0;
4947 if (!*str) /* EOL - do not finalize word */
4949 word_len = strcspn(str, G.ifs);
4951 /* We have WORD_LEN leading non-IFS chars */
4952 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
4953 o_addblock(output, str, word_len);
4955 /* Protect backslashes against globbing up :)
4956 * Example: "v='\*'; echo b$v" prints "b\*"
4957 * (and does not try to glob on "*")
4959 o_addblock_duplicate_backslash(output, str, word_len);
4960 /*/ Why can't we do it easier? */
4961 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4962 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4966 if (!*str) /* EOL - do not finalize word */
4970 /* We know str here points to at least one IFS char */
4972 str += strspn(str, G.ifs); /* skip IFS chars */
4973 if (!*str) /* EOL - do not finalize word */
4976 /* Start new word... but not always! */
4977 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
4978 if (output->has_quoted_part
4979 /* Case "v=' a'; echo $v":
4980 * here nothing precedes the space in $v expansion,
4981 * therefore we should not finish the word
4982 * (IOW: if there *is* word to finalize, only then do it):
4984 || (n > 0 && output->data[output->length - 1])
4986 o_addchr(output, '\0');
4987 debug_print_list("expand_on_ifs", output, n);
4988 n = o_save_ptr(output, n);
4993 *ended_with_ifs = last_is_ifs;
4994 debug_print_list("expand_on_ifs[1]", output, n);
4998 /* Helper to expand $((...)) and heredoc body. These act as if
4999 * they are in double quotes, with the exception that they are not :).
5000 * Just the rules are similar: "expand only $var and `cmd`"
5002 * Returns malloced string.
5003 * As an optimization, we return NULL if expansion is not needed.
5005 #if !ENABLE_HUSH_BASH_COMPAT
5006 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5007 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5008 encode_then_expand_string(str)
5010 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5013 struct in_str input;
5014 o_string dest = NULL_O_STRING;
5016 if (!strchr(str, '$')
5017 && !strchr(str, '\\')
5018 #if ENABLE_HUSH_TICK
5019 && !strchr(str, '`')
5025 /* We need to expand. Example:
5026 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5028 setup_string_in_str(&input, str);
5029 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5030 //TODO: error check (encode_string returns 0 on error)?
5031 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5032 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5033 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5034 o_free_unsafe(&dest);
5038 #if ENABLE_SH_MATH_SUPPORT
5039 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5041 arith_state_t math_state;
5045 math_state.lookupvar = get_local_var_value;
5046 math_state.setvar = set_local_var_from_halves;
5047 //math_state.endofname = endofname;
5048 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5049 res = arith(&math_state, exp_str ? exp_str : arg);
5052 *errmsg_p = math_state.errmsg;
5053 if (math_state.errmsg)
5054 die_if_script(math_state.errmsg);
5059 #if ENABLE_HUSH_BASH_COMPAT
5060 /* ${var/[/]pattern[/repl]} helpers */
5061 static char *strstr_pattern(char *val, const char *pattern, int *size)
5064 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5065 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5072 /* Optimization: if "*pat" did not match the start of "string",
5073 * we know that "tring", "ring" etc will not match too:
5075 if (pattern[0] == '*')
5080 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5082 char *result = NULL;
5083 unsigned res_len = 0;
5084 unsigned repl_len = strlen(repl);
5088 char *s = strstr_pattern(val, pattern, &size);
5092 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5093 memcpy(result + res_len, val, s - val);
5095 strcpy(result + res_len, repl);
5096 res_len += repl_len;
5097 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5103 if (val[0] && result) {
5104 result = xrealloc(result, res_len + strlen(val) + 1);
5105 strcpy(result + res_len, val);
5106 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5108 debug_printf_varexp("result:'%s'\n", result);
5114 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5116 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5118 const char *val = NULL;
5119 char *to_be_freed = NULL;
5124 char exp_save = exp_save; /* for compiler */
5125 char *exp_saveptr; /* points to expansion operator */
5126 char *exp_word = exp_word; /* for compiler */
5129 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5131 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5133 first_char = arg[0] = arg0 & 0x7f;
5136 if (first_char == '#' /* ${#... */
5137 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5139 /* It must be length operator: ${#var} */
5143 /* Maybe handle parameter expansion */
5144 if (exp_saveptr /* if 2nd char is one of expansion operators */
5145 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5147 /* ${?:0}, ${#[:]%0} etc */
5148 exp_saveptr = var + 1;
5150 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5151 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5153 exp_op = exp_save = *exp_saveptr;
5155 exp_word = exp_saveptr + 1;
5156 if (exp_op == ':') {
5157 exp_op = *exp_word++;
5158 //TODO: try ${var:} and ${var:bogus} in non-bash config
5159 if (ENABLE_HUSH_BASH_COMPAT
5160 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5162 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5167 *exp_saveptr = '\0';
5168 } /* else: it's not an expansion op, but bare ${var} */
5171 /* Look up the variable in question */
5172 if (isdigit(var[0])) {
5173 /* parse_dollar should have vetted var for us */
5174 int n = xatoi_positive(var);
5175 if (n < G.global_argc)
5176 val = G.global_argv[n];
5177 /* else val remains NULL: $N with too big N */
5181 val = utoa(G.root_pid);
5183 case '!': /* bg pid */
5184 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5186 case '?': /* exitcode */
5187 val = utoa(G.last_exitcode);
5189 case '#': /* argc */
5190 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5193 val = get_local_var_value(var);
5197 /* Handle any expansions */
5198 if (exp_op == 'L') {
5199 reinit_unicode_for_hush();
5200 debug_printf_expand("expand: length(%s)=", val);
5201 val = utoa(val ? unicode_strlen(val) : 0);
5202 debug_printf_expand("%s\n", val);
5203 } else if (exp_op) {
5204 if (exp_op == '%' || exp_op == '#') {
5205 /* Standard-mandated substring removal ops:
5206 * ${parameter%word} - remove smallest suffix pattern
5207 * ${parameter%%word} - remove largest suffix pattern
5208 * ${parameter#word} - remove smallest prefix pattern
5209 * ${parameter##word} - remove largest prefix pattern
5211 * Word is expanded to produce a glob pattern.
5212 * Then var's value is matched to it and matching part removed.
5214 if (val && val[0]) {
5218 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5219 if (exp_op == *exp_word) /* ## or %% */
5221 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5223 exp_word = exp_exp_word;
5224 /* HACK ALERT. We depend here on the fact that
5225 * G.global_argv and results of utoa and get_local_var_value
5226 * are actually in writable memory:
5227 * scan_and_match momentarily stores NULs there. */
5229 loc = scan_and_match(t, exp_word, scan_flags);
5230 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5231 // exp_op, t, exp_word, loc);
5233 if (loc) { /* match was found */
5234 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5235 val = loc; /* take right part */
5237 val = to_be_freed = xstrndup(val, loc - val); /* left */
5241 #if ENABLE_HUSH_BASH_COMPAT
5242 else if (exp_op == '/' || exp_op == '\\') {
5243 /* It's ${var/[/]pattern[/repl]} thing.
5244 * Note that in encoded form it has TWO parts:
5245 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5246 * and if // is used, it is encoded as \:
5247 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5249 /* Empty variable always gives nothing: */
5250 // "v=''; echo ${v/*/w}" prints "", not "w"
5251 if (val && val[0]) {
5252 /* pattern uses non-standard expansion.
5253 * repl should be unbackslashed and globbed
5254 * by the usual expansion rules:
5256 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5257 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5258 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5259 * v='a bz'; echo ${v/a*z/\z} prints "z"
5260 * (note that a*z _pattern_ is never globbed!)
5262 char *pattern, *repl, *t;
5263 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5265 pattern = xstrdup(exp_word);
5266 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5267 *p++ = SPECIAL_VAR_SYMBOL;
5269 p = strchr(p, SPECIAL_VAR_SYMBOL);
5271 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5272 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5273 /* HACK ALERT. We depend here on the fact that
5274 * G.global_argv and results of utoa and get_local_var_value
5275 * are actually in writable memory:
5276 * replace_pattern momentarily stores NULs there. */
5278 to_be_freed = replace_pattern(t,
5280 (repl ? repl : exp_word),
5282 if (to_be_freed) /* at least one replace happened */
5289 else if (exp_op == ':') {
5290 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5291 /* It's ${var:N[:M]} bashism.
5292 * Note that in encoded form it has TWO parts:
5293 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5298 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5301 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5302 *p++ = SPECIAL_VAR_SYMBOL;
5304 p = strchr(p, SPECIAL_VAR_SYMBOL);
5306 len = expand_and_evaluate_arith(exp_word, &errmsg);
5309 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5310 if (len >= 0) { /* bash compat: len < 0 is illegal */
5311 if (beg < 0) /* bash compat */
5313 debug_printf_varexp("from val:'%s'\n", val);
5314 if (len == 0 || !val || beg >= strlen(val)) {
5318 /* Paranoia. What if user entered 9999999999999
5319 * which fits in arith_t but not int? */
5322 val = to_be_freed = xstrndup(val + beg, len);
5324 debug_printf_varexp("val:'%s'\n", val);
5328 die_if_script("malformed ${%s:...}", var);
5331 } else { /* one of "-=+?" */
5332 /* Standard-mandated substitution ops:
5333 * ${var?word} - indicate error if unset
5334 * If var is unset, word (or a message indicating it is unset
5335 * if word is null) is written to standard error
5336 * and the shell exits with a non-zero exit status.
5337 * Otherwise, the value of var is substituted.
5338 * ${var-word} - use default value
5339 * If var is unset, word is substituted.
5340 * ${var=word} - assign and use default value
5341 * If var is unset, word is assigned to var.
5342 * In all cases, final value of var is substituted.
5343 * ${var+word} - use alternative value
5344 * If var is unset, null is substituted.
5345 * Otherwise, word is substituted.
5347 * Word is subjected to tilde expansion, parameter expansion,
5348 * command substitution, and arithmetic expansion.
5349 * If word is not needed, it is not expanded.
5351 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5352 * but also treat null var as if it is unset.
5354 int use_word = (!val || ((exp_save == ':') && !val[0]));
5356 use_word = !use_word;
5357 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5358 (exp_save == ':') ? "true" : "false", use_word);
5360 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5362 exp_word = to_be_freed;
5363 if (exp_op == '?') {
5364 /* mimic bash message */
5365 die_if_script("%s: %s",
5367 exp_word[0] ? exp_word : "parameter null or not set"
5369 //TODO: how interactive bash aborts expansion mid-command?
5374 if (exp_op == '=') {
5375 /* ${var=[word]} or ${var:=[word]} */
5376 if (isdigit(var[0]) || var[0] == '#') {
5377 /* mimic bash message */
5378 die_if_script("$%s: cannot assign in this way", var);
5381 char *new_var = xasprintf("%s=%s", var, val);
5382 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5386 } /* one of "-=+?" */
5388 *exp_saveptr = exp_save;
5394 *to_be_freed_pp = to_be_freed;
5398 /* Expand all variable references in given string, adding words to list[]
5399 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5400 * to be filled). This routine is extremely tricky: has to deal with
5401 * variables/parameters with whitespace, $* and $@, and constructs like
5402 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5403 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5405 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5406 * expansion of right-hand side of assignment == 1-element expand.
5408 char cant_be_null = 0; /* only bit 0x80 matters */
5409 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5412 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5413 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5414 debug_print_list("expand_vars_to_list", output, n);
5415 n = o_save_ptr(output, n);
5416 debug_print_list("expand_vars_to_list[0]", output, n);
5418 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5420 char *to_be_freed = NULL;
5421 const char *val = NULL;
5422 #if ENABLE_HUSH_TICK
5423 o_string subst_result = NULL_O_STRING;
5425 #if ENABLE_SH_MATH_SUPPORT
5426 char arith_buf[sizeof(arith_t)*3 + 2];
5430 o_addchr(output, '\0');
5431 n = o_save_ptr(output, n);
5435 o_addblock(output, arg, p - arg);
5436 debug_print_list("expand_vars_to_list[1]", output, n);
5438 p = strchr(p, SPECIAL_VAR_SYMBOL);
5440 /* Fetch special var name (if it is indeed one of them)
5441 * and quote bit, force the bit on if singleword expansion -
5442 * important for not getting v=$@ expand to many words. */
5443 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5445 /* Is this variable quoted and thus expansion can't be null?
5446 * "$@" is special. Even if quoted, it can still
5447 * expand to nothing (not even an empty string),
5448 * thus it is excluded. */
5449 if ((first_ch & 0x7f) != '@')
5450 cant_be_null |= first_ch;
5452 switch (first_ch & 0x7f) {
5453 /* Highest bit in first_ch indicates that var is double-quoted */
5457 if (!G.global_argv[1])
5460 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5461 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5462 while (G.global_argv[i]) {
5463 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5464 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5465 if (G.global_argv[i++][0] && G.global_argv[i]) {
5466 /* this argv[] is not empty and not last:
5467 * put terminating NUL, start new word */
5468 o_addchr(output, '\0');
5469 debug_print_list("expand_vars_to_list[2]", output, n);
5470 n = o_save_ptr(output, n);
5471 debug_print_list("expand_vars_to_list[3]", output, n);
5475 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5476 * and in this case should treat it like '$*' - see 'else...' below */
5477 if (first_ch == ('@'|0x80) /* quoted $@ */
5478 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5481 o_addQstr(output, G.global_argv[i]);
5482 if (++i >= G.global_argc)
5484 o_addchr(output, '\0');
5485 debug_print_list("expand_vars_to_list[4]", output, n);
5486 n = o_save_ptr(output, n);
5488 } else { /* quoted $* (or v="$@" case): add as one word */
5490 o_addQstr(output, G.global_argv[i]);
5491 if (!G.global_argv[++i])
5494 o_addchr(output, G.ifs[0]);
5496 output->has_quoted_part = 1;
5500 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5501 /* "Empty variable", used to make "" etc to not disappear */
5502 output->has_quoted_part = 1;
5504 cant_be_null = 0x80;
5506 #if ENABLE_HUSH_TICK
5507 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5508 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5510 /* Can't just stuff it into output o_string,
5511 * expanded result may need to be globbed
5512 * and $IFS-splitted */
5513 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5514 G.last_exitcode = process_command_subs(&subst_result, arg);
5515 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5516 val = subst_result.data;
5519 #if ENABLE_SH_MATH_SUPPORT
5520 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5523 arg++; /* skip '+' */
5524 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5525 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5526 res = expand_and_evaluate_arith(arg, NULL);
5527 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5528 sprintf(arith_buf, ARITH_FMT, res);
5534 val = expand_one_var(&to_be_freed, arg, &p);
5535 IF_HUSH_TICK(store_val:)
5536 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5537 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5538 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5539 if (val && val[0]) {
5540 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5543 } else { /* quoted $VAR, val will be appended below */
5544 output->has_quoted_part = 1;
5545 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5546 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5549 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5551 if (val && val[0]) {
5552 o_addQstr(output, val);
5556 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5557 * Do the check to avoid writing to a const string. */
5558 if (*p != SPECIAL_VAR_SYMBOL)
5559 *p = SPECIAL_VAR_SYMBOL;
5561 #if ENABLE_HUSH_TICK
5562 o_free(&subst_result);
5565 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5569 o_addchr(output, '\0');
5570 n = o_save_ptr(output, n);
5572 debug_print_list("expand_vars_to_list[a]", output, n);
5573 /* this part is literal, and it was already pre-quoted
5574 * if needed (much earlier), do not use o_addQstr here! */
5575 o_addstr_with_NUL(output, arg);
5576 debug_print_list("expand_vars_to_list[b]", output, n);
5577 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5578 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5581 /* allow to reuse list[n] later without re-growth */
5582 output->has_empty_slot = 1;
5584 o_addchr(output, '\0');
5590 static char **expand_variables(char **argv, unsigned expflags)
5594 o_string output = NULL_O_STRING;
5596 output.o_expflags = expflags;
5600 n = expand_vars_to_list(&output, n, *argv);
5603 debug_print_list("expand_variables", &output, n);
5605 /* output.data (malloced in one block) gets returned in "list" */
5606 list = o_finalize_list(&output, n);
5607 debug_print_strings("expand_variables[1]", list);
5611 static char **expand_strvec_to_strvec(char **argv)
5613 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5616 #if ENABLE_HUSH_BASH_COMPAT
5617 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5619 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5623 /* Used for expansion of right hand of assignments,
5624 * $((...)), heredocs, variable espansion parts.
5626 * NB: should NOT do globbing!
5627 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5629 static char *expand_string_to_string(const char *str, int do_unbackslash)
5631 #if !ENABLE_HUSH_BASH_COMPAT
5632 const int do_unbackslash = 1;
5634 char *argv[2], **list;
5636 debug_printf_expand("string_to_string<='%s'\n", str);
5637 /* This is generally an optimization, but it also
5638 * handles "", which otherwise trips over !list[0] check below.
5639 * (is this ever happens that we actually get str="" here?)
5641 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5642 //TODO: Can use on strings with \ too, just unbackslash() them?
5643 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5644 return xstrdup(str);
5647 argv[0] = (char*)str;
5649 list = expand_variables(argv, do_unbackslash
5650 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5651 : EXP_FLAG_SINGLEWORD
5654 if (!list[0] || list[1])
5655 bb_error_msg_and_die("BUG in varexp2");
5656 /* actually, just move string 2*sizeof(char*) bytes back */
5657 overlapping_strcpy((char*)list, list[0]);
5659 unbackslash((char*)list);
5660 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5664 /* Used for "eval" builtin */
5665 static char* expand_strvec_to_string(char **argv)
5669 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5670 /* Convert all NULs to spaces */
5675 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5676 bb_error_msg_and_die("BUG in varexp3");
5677 /* bash uses ' ' regardless of $IFS contents */
5682 overlapping_strcpy((char*)list, list[0]);
5683 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5687 static char **expand_assignments(char **argv, int count)
5692 G.expanded_assignments = p = NULL;
5693 /* Expand assignments into one string each */
5694 for (i = 0; i < count; i++) {
5695 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5697 G.expanded_assignments = NULL;
5702 static void switch_off_special_sigs(unsigned mask)
5705 while ((mask >>= 1) != 0) {
5710 if (G.traps[sig] && !G.traps[sig][0])
5711 /* trap is '', has to remain SIG_IGN */
5714 G.traps[sig] = NULL;
5716 /* We are here only if no trap or trap was not '' */
5717 install_sighandler(sig, SIG_DFL);
5723 void re_execute_shell(char ***to_free, const char *s,
5724 char *g_argv0, char **g_argv,
5725 char **builtin_argv) NORETURN;
5727 static void reset_traps_to_defaults(void)
5729 /* This function is always called in a child shell
5730 * after fork (not vfork, NOMMU doesn't use this function).
5735 /* Child shells are not interactive.
5736 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5737 * Testcase: (while :; do :; done) + ^Z should background.
5738 * Same goes for SIGTERM, SIGHUP, SIGINT.
5740 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5741 if (!G.traps && !mask)
5742 return; /* already no traps and no special sigs */
5744 /* Switch off special sigs */
5745 switch_off_special_sigs(mask);
5747 G_fatal_sig_mask = 0;
5749 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5750 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5751 * remain set in G.special_sig_mask */
5756 /* Reset all sigs to default except ones with empty traps */
5757 for (sig = 0; sig < NSIG; sig++) {
5759 continue; /* no trap: nothing to do */
5760 if (!G.traps[sig][0])
5761 continue; /* empty trap: has to remain SIG_IGN */
5762 /* sig has non-empty trap, reset it: */
5764 G.traps[sig] = NULL;
5765 /* There is no signal for trap 0 (EXIT) */
5768 install_sighandler(sig, pick_sighandler(sig));
5774 static void re_execute_shell(char ***to_free, const char *s,
5775 char *g_argv0, char **g_argv,
5776 char **builtin_argv) NORETURN;
5777 static void re_execute_shell(char ***to_free, const char *s,
5778 char *g_argv0, char **g_argv,
5779 char **builtin_argv)
5781 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5782 /* delims + 2 * (number of bytes in printed hex numbers) */
5783 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5784 char *heredoc_argv[4];
5785 struct variable *cur;
5786 # if ENABLE_HUSH_FUNCTIONS
5787 struct function *funcp;
5791 unsigned long long empty_trap_mask;
5793 if (!g_argv0) { /* heredoc */
5794 argv = heredoc_argv;
5795 argv[0] = (char *) G.argv0_for_re_execing;
5796 argv[1] = (char *) "-<";
5797 argv[2] = (char *) s;
5799 pp = &argv[3]; /* used as pointer to empty environment */
5805 if (pp) while (*pp++)
5808 empty_trap_mask = 0;
5811 for (sig = 1; sig < NSIG; sig++) {
5812 if (G.traps[sig] && !G.traps[sig][0])
5813 empty_trap_mask |= 1LL << sig;
5817 sprintf(param_buf, NOMMU_HACK_FMT
5818 , (unsigned) G.root_pid
5819 , (unsigned) G.root_ppid
5820 , (unsigned) G.last_bg_pid
5821 , (unsigned) G.last_exitcode
5824 IF_HUSH_LOOPS(, G.depth_of_loop)
5826 # undef NOMMU_HACK_FMT
5827 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5828 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5831 for (cur = G.top_var; cur; cur = cur->next) {
5832 if (!cur->flg_export || cur->flg_read_only)
5835 # if ENABLE_HUSH_FUNCTIONS
5836 for (funcp = G.top_func; funcp; funcp = funcp->next)
5842 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5843 *pp++ = (char *) G.argv0_for_re_execing;
5845 for (cur = G.top_var; cur; cur = cur->next) {
5846 if (strcmp(cur->varstr, hush_version_str) == 0)
5848 if (cur->flg_read_only) {
5849 *pp++ = (char *) "-R";
5850 *pp++ = cur->varstr;
5851 } else if (!cur->flg_export) {
5852 *pp++ = (char *) "-V";
5853 *pp++ = cur->varstr;
5856 # if ENABLE_HUSH_FUNCTIONS
5857 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5858 *pp++ = (char *) "-F";
5859 *pp++ = funcp->name;
5860 *pp++ = funcp->body_as_string;
5863 /* We can pass activated traps here. Say, -Tnn:trap_string
5865 * However, POSIX says that subshells reset signals with traps
5867 * I tested bash-3.2 and it not only does that with true subshells
5868 * of the form ( list ), but with any forked children shells.
5869 * I set trap "echo W" WINCH; and then tried:
5871 * { echo 1; sleep 20; echo 2; } &
5872 * while true; do echo 1; sleep 20; echo 2; break; done &
5873 * true | { echo 1; sleep 20; echo 2; } | cat
5875 * In all these cases sending SIGWINCH to the child shell
5876 * did not run the trap. If I add trap "echo V" WINCH;
5877 * _inside_ group (just before echo 1), it works.
5879 * I conclude it means we don't need to pass active traps here.
5881 *pp++ = (char *) "-c";
5884 while (*++builtin_argv)
5885 *pp++ = *builtin_argv;
5886 *pp++ = (char *) "";
5891 /* *pp = NULL; - is already there */
5895 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5896 /* Don't propagate SIG_IGN to the child */
5897 if (SPECIAL_JOBSTOP_SIGS != 0)
5898 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
5899 execve(bb_busybox_exec_path, argv, pp);
5900 /* Fallback. Useful for init=/bin/hush usage etc */
5901 if (argv[0][0] == '/')
5902 execve(argv[0], argv, pp);
5903 xfunc_error_retval = 127;
5904 bb_error_msg_and_die("can't re-execute the shell");
5906 #endif /* !BB_MMU */
5909 static int run_and_free_list(struct pipe *pi);
5911 /* Executing from string: eval, sh -c '...'
5912 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5913 * end_trigger controls how often we stop parsing
5914 * NUL: parse all, execute, return
5915 * ';': parse till ';' or newline, execute, repeat till EOF
5917 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5919 /* Why we need empty flag?
5920 * An obscure corner case "false; ``; echo $?":
5921 * empty command in `` should still set $? to 0.
5922 * But we can't just set $? to 0 at the start,
5923 * this breaks "false; echo `echo $?`" case.
5927 struct pipe *pipe_list;
5929 #if ENABLE_HUSH_INTERACTIVE
5930 if (end_trigger == ';')
5931 inp->promptmode = 0; /* PS1 */
5933 pipe_list = parse_stream(NULL, inp, end_trigger);
5934 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
5935 /* If we are in "big" script
5936 * (not in `cmd` or something similar)...
5938 if (pipe_list == ERR_PTR && end_trigger == ';') {
5939 /* Discard cached input (rest of line) */
5940 int ch = inp->last_char;
5941 while (ch != EOF && ch != '\n') {
5942 //bb_error_msg("Discarded:'%c'", ch);
5947 /* This stream isn't empty */
5951 if (!pipe_list && empty)
5952 G.last_exitcode = 0;
5955 debug_print_tree(pipe_list, 0);
5956 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5957 run_and_free_list(pipe_list);
5959 #if ENABLE_HUSH_FUNCTIONS
5960 if (G.flag_return_in_progress == 1)
5966 static void parse_and_run_string(const char *s)
5968 struct in_str input;
5969 setup_string_in_str(&input, s);
5970 parse_and_run_stream(&input, '\0');
5973 static void parse_and_run_file(FILE *f)
5975 struct in_str input;
5976 setup_file_in_str(&input, f);
5977 parse_and_run_stream(&input, ';');
5980 #if ENABLE_HUSH_TICK
5981 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5986 char **to_free = NULL;
5990 pid = BB_MMU ? xfork() : xvfork();
5991 if (pid == 0) { /* child */
5992 disable_restore_tty_pgrp_on_exit();
5993 /* Process substitution is not considered to be usual
5994 * 'command execution'.
5995 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6002 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6003 close(channel[0]); /* NB: close _first_, then move fd! */
6004 xmove_fd(channel[1], 1);
6005 /* Prevent it from trying to handle ctrl-z etc */
6006 IF_HUSH_JOB(G.run_list_level = 1;)
6007 /* Awful hack for `trap` or $(trap).
6009 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6010 * contains an example where "trap" is executed in a subshell:
6012 * save_traps=$(trap)
6014 * eval "$save_traps"
6016 * Standard does not say that "trap" in subshell shall print
6017 * parent shell's traps. It only says that its output
6018 * must have suitable form, but then, in the above example
6019 * (which is not supposed to be normative), it implies that.
6021 * bash (and probably other shell) does implement it
6022 * (traps are reset to defaults, but "trap" still shows them),
6023 * but as a result, "trap" logic is hopelessly messed up:
6026 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6027 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6028 * # true | trap <--- trap is in subshell - no output (ditto)
6029 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6030 * trap -- 'echo Ho' SIGWINCH
6031 * # echo `(trap)` <--- in subshell in subshell - output
6032 * trap -- 'echo Ho' SIGWINCH
6033 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6034 * trap -- 'echo Ho' SIGWINCH
6036 * The rules when to forget and when to not forget traps
6037 * get really complex and nonsensical.
6039 * Our solution: ONLY bare $(trap) or `trap` is special.
6041 s = skip_whitespace(s);
6042 if (is_prefixed_with(s, "trap")
6043 && skip_whitespace(s + 4)[0] == '\0'
6045 static const char *const argv[] = { NULL, NULL };
6046 builtin_trap((char**)argv);
6047 fflush_all(); /* important */
6051 reset_traps_to_defaults();
6052 parse_and_run_string(s);
6053 _exit(G.last_exitcode);
6055 /* We re-execute after vfork on NOMMU. This makes this script safe:
6056 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6057 * huge=`cat BIG` # was blocking here forever
6060 re_execute_shell(&to_free,
6070 # if ENABLE_HUSH_FAST
6072 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6073 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6074 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6076 enable_restore_tty_pgrp_on_exit();
6081 return remember_FILE(xfdopen_for_read(channel[0]));
6084 /* Return code is exit status of the process that is run. */
6085 static int process_command_subs(o_string *dest, const char *s)
6088 struct in_str pipe_str;
6090 int status, ch, eol_cnt;
6092 fp = generate_stream_from_string(s, &pid);
6094 /* Now send results of command back into original context */
6095 setup_file_in_str(&pipe_str, fp);
6097 while ((ch = i_getch(&pipe_str)) != EOF) {
6103 o_addchr(dest, '\n');
6106 o_addQchr(dest, ch);
6109 debug_printf("done reading from `cmd` pipe, closing it\n");
6110 fclose_and_forget(fp);
6111 /* We need to extract exitcode. Test case
6112 * "true; echo `sleep 1; false` $?"
6114 safe_waitpid(pid, &status, 0);
6115 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6116 return WEXITSTATUS(status);
6118 #endif /* ENABLE_HUSH_TICK */
6121 static void setup_heredoc(struct redir_struct *redir)
6123 struct fd_pair pair;
6126 /* the _body_ of heredoc (misleading field name) */
6127 const char *heredoc = redir->rd_filename;
6134 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6135 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6139 len = strlen(heredoc);
6141 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6143 xmove_fd(pair.rd, redir->rd_fd);
6145 /* Try writing without forking. Newer kernels have
6146 * dynamically growing pipes. Must use non-blocking write! */
6149 written = write(pair.wr, heredoc, len);
6160 ndelay_off(pair.wr);
6162 /* Okay, pipe buffer was not big enough */
6163 /* Note: we must not create a stray child (bastard? :)
6164 * for the unsuspecting parent process. Child creates a grandchild
6165 * and exits before parent execs the process which consumes heredoc
6166 * (that exec happens after we return from this function) */
6173 disable_restore_tty_pgrp_on_exit();
6174 pid = BB_MMU ? xfork() : xvfork();
6178 close(redir->rd_fd); /* read side of the pipe */
6180 full_write(pair.wr, heredoc, len); /* may loop or block */
6183 /* Delegate blocking writes to another process */
6184 xmove_fd(pair.wr, STDOUT_FILENO);
6185 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6189 #if ENABLE_HUSH_FAST
6191 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6193 enable_restore_tty_pgrp_on_exit();
6199 wait(NULL); /* wait till child has died */
6202 /* fd: redirect wants this fd to be used (e.g. 3>file).
6203 * Move all conflicting internally used fds,
6204 * and remember them so that we can restore them later.
6206 static int save_fds_on_redirect(int fd, int squirrel[3])
6209 /* Handle redirects of fds 0,1,2 */
6211 /* If we collide with an already moved stdio fd... */
6212 if (fd == squirrel[0]) {
6213 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6216 if (fd == squirrel[1]) {
6217 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6220 if (fd == squirrel[2]) {
6221 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6224 /* If we are about to redirect stdio fd, and did not yet move it... */
6225 if (fd <= 2 && squirrel[fd] < 0) {
6226 /* We avoid taking stdio fds */
6227 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6228 if (squirrel[fd] < 0 && errno != EBADF)
6230 return 0; /* "we did not close fd" */
6234 #if ENABLE_HUSH_INTERACTIVE
6235 if (fd != 0 && fd == G.interactive_fd) {
6236 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6241 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6242 * (1) Redirect in a forked child. No need to save FILEs' fds,
6243 * we aren't going to use them anymore, ok to trash.
6244 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6245 * but how are we doing to use them?
6246 * "fileno(fd) = new_fd" can't be done.
6251 return save_FILEs_on_redirect(fd);
6254 static void restore_redirects(int squirrel[3])
6257 for (i = 0; i <= 2; i++) {
6260 /* We simply die on error */
6265 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6267 restore_redirected_FILEs();
6270 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6271 * and stderr if they are redirected. */
6272 static int setup_redirects(struct command *prog, int squirrel[])
6275 struct redir_struct *redir;
6277 for (redir = prog->redirects; redir; redir = redir->next) {
6278 if (redir->rd_type == REDIRECT_HEREDOC2) {
6279 /* "rd_fd<<HERE" case */
6280 save_fds_on_redirect(redir->rd_fd, squirrel);
6281 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6283 debug_printf_parse("set heredoc '%s'\n",
6284 redir->rd_filename);
6285 setup_heredoc(redir);
6289 if (redir->rd_dup == REDIRFD_TO_FILE) {
6290 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6292 if (redir->rd_filename == NULL) {
6295 * "cmd >" (no filename)
6296 * "cmd > <file" (2nd redirect starts too early)
6298 die_if_script("syntax error: %s", "invalid redirect");
6301 mode = redir_table[redir->rd_type].mode;
6302 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6303 openfd = open_or_warn(p, mode);
6306 /* Error message from open_or_warn can be lost
6307 * if stderr has been redirected, but bash
6308 * and ash both lose it as well
6309 * (though zsh doesn't!)
6314 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6315 openfd = redir->rd_dup;
6318 if (openfd != redir->rd_fd) {
6319 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6320 if (openfd == REDIRFD_CLOSE) {
6321 /* "rd_fd >&-" means "close me" */
6323 /* ^^^ optimization: saving may already
6324 * have closed it. If not... */
6325 close(redir->rd_fd);
6328 xdup2(openfd, redir->rd_fd);
6329 if (redir->rd_dup == REDIRFD_TO_FILE)
6330 /* "rd_fd > FILE" */
6332 /* else: "rd_fd > rd_dup" */
6339 static char *find_in_path(const char *arg)
6342 const char *PATH = get_local_var_value("PATH");
6348 const char *end = strchrnul(PATH, ':');
6349 int sz = end - PATH; /* must be int! */
6353 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6355 /* We have xxx::yyyy in $PATH,
6356 * it means "use current dir" */
6359 if (access(ret, F_OK) == 0)
6372 static const struct built_in_command *find_builtin_helper(const char *name,
6373 const struct built_in_command *x,
6374 const struct built_in_command *end)
6377 if (strcmp(name, x->b_cmd) != 0) {
6381 debug_printf_exec("found builtin '%s'\n", name);
6386 static const struct built_in_command *find_builtin1(const char *name)
6388 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6390 static const struct built_in_command *find_builtin(const char *name)
6392 const struct built_in_command *x = find_builtin1(name);
6395 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6398 #if ENABLE_HUSH_FUNCTIONS
6399 static struct function **find_function_slot(const char *name)
6401 struct function **funcpp = &G.top_func;
6403 if (strcmp(name, (*funcpp)->name) == 0) {
6406 funcpp = &(*funcpp)->next;
6411 static const struct function *find_function(const char *name)
6413 const struct function *funcp = *find_function_slot(name);
6415 debug_printf_exec("found function '%s'\n", name);
6419 /* Note: takes ownership on name ptr */
6420 static struct function *new_function(char *name)
6422 struct function **funcpp = find_function_slot(name);
6423 struct function *funcp = *funcpp;
6425 if (funcp != NULL) {
6426 struct command *cmd = funcp->parent_cmd;
6427 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6429 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6431 /* Note: if !funcp->body, do not free body_as_string!
6432 * This is a special case of "-F name body" function:
6433 * body_as_string was not malloced! */
6435 free_pipe_list(funcp->body);
6437 free(funcp->body_as_string);
6441 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6442 cmd->argv[0] = funcp->name;
6443 cmd->group = funcp->body;
6445 cmd->group_as_string = funcp->body_as_string;
6449 debug_printf_exec("remembering new function '%s'\n", name);
6450 funcp = *funcpp = xzalloc(sizeof(*funcp));
6451 /*funcp->next = NULL;*/
6458 static void unset_func(const char *name)
6460 struct function **funcpp = find_function_slot(name);
6461 struct function *funcp = *funcpp;
6463 if (funcp != NULL) {
6464 debug_printf_exec("freeing function '%s'\n", funcp->name);
6465 *funcpp = funcp->next;
6466 /* funcp is unlinked now, deleting it.
6467 * Note: if !funcp->body, the function was created by
6468 * "-F name body", do not free ->body_as_string
6469 * and ->name as they were not malloced. */
6471 free_pipe_list(funcp->body);
6474 free(funcp->body_as_string);
6482 #define exec_function(to_free, funcp, argv) \
6483 exec_function(funcp, argv)
6485 static void exec_function(char ***to_free,
6486 const struct function *funcp,
6487 char **argv) NORETURN;
6488 static void exec_function(char ***to_free,
6489 const struct function *funcp,
6495 argv[0] = G.global_argv[0];
6496 G.global_argv = argv;
6500 /* On MMU, funcp->body is always non-NULL */
6501 n = run_list(funcp->body);
6505 re_execute_shell(to_free,
6506 funcp->body_as_string,
6513 static int run_function(const struct function *funcp, char **argv)
6519 save_and_replace_G_args(&sv, argv);
6521 /* "we are in function, ok to use return" */
6522 sv_flg = G.flag_return_in_progress;
6523 G.flag_return_in_progress = -1;
6524 # if ENABLE_HUSH_LOCAL
6525 G.func_nest_level++;
6528 /* On MMU, funcp->body is always non-NULL */
6531 /* Function defined by -F */
6532 parse_and_run_string(funcp->body_as_string);
6533 rc = G.last_exitcode;
6537 rc = run_list(funcp->body);
6540 # if ENABLE_HUSH_LOCAL
6542 struct variable *var;
6543 struct variable **var_pp;
6545 var_pp = &G.top_var;
6546 while ((var = *var_pp) != NULL) {
6547 if (var->func_nest_level < G.func_nest_level) {
6548 var_pp = &var->next;
6552 if (var->flg_export)
6553 bb_unsetenv(var->varstr);
6554 /* Remove from global list */
6555 *var_pp = var->next;
6561 G.func_nest_level--;
6564 G.flag_return_in_progress = sv_flg;
6566 restore_G_args(&sv, argv);
6570 #endif /* ENABLE_HUSH_FUNCTIONS */
6574 #define exec_builtin(to_free, x, argv) \
6575 exec_builtin(x, argv)
6577 #define exec_builtin(to_free, x, argv) \
6578 exec_builtin(to_free, argv)
6580 static void exec_builtin(char ***to_free,
6581 const struct built_in_command *x,
6582 char **argv) NORETURN;
6583 static void exec_builtin(char ***to_free,
6584 const struct built_in_command *x,
6590 rcode = x->b_function(argv);
6595 /* On NOMMU, we must never block!
6596 * Example: { sleep 99 | read line; } & echo Ok
6598 re_execute_shell(to_free,
6607 static void execvp_or_die(char **argv) NORETURN;
6608 static void execvp_or_die(char **argv)
6610 debug_printf_exec("execing '%s'\n", argv[0]);
6611 /* Don't propagate SIG_IGN to the child */
6612 if (SPECIAL_JOBSTOP_SIGS != 0)
6613 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6614 execvp(argv[0], argv);
6615 bb_perror_msg("can't execute '%s'", argv[0]);
6616 _exit(127); /* bash compat */
6619 #if ENABLE_HUSH_MODE_X
6620 static void dump_cmd_in_x_mode(char **argv)
6622 if (G_x_mode && argv) {
6623 /* We want to output the line in one write op */
6631 len += strlen(argv[n++]) + 1;
6637 p += sprintf(p, " %s", argv[n++]);
6645 # define dump_cmd_in_x_mode(argv) ((void)0)
6649 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6650 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6651 #define pseudo_exec(nommu_save, command, argv_expanded) \
6652 pseudo_exec(command, argv_expanded)
6655 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6657 * Don't exit() here. If you don't exec, use _exit instead.
6658 * The at_exit handlers apparently confuse the calling process,
6659 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6661 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6662 char **argv, int assignment_cnt,
6663 char **argv_expanded) NORETURN;
6664 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6665 char **argv, int assignment_cnt,
6666 char **argv_expanded)
6670 new_env = expand_assignments(argv, assignment_cnt);
6671 dump_cmd_in_x_mode(new_env);
6673 if (!argv[assignment_cnt]) {
6674 /* Case when we are here: ... | var=val | ...
6675 * (note that we do not exit early, i.e., do not optimize out
6676 * expand_assignments(): think about ... | var=`sleep 1` | ...
6678 free_strings(new_env);
6679 _exit(EXIT_SUCCESS);
6683 set_vars_and_save_old(new_env);
6684 free(new_env); /* optional */
6685 /* we can also destroy set_vars_and_save_old's return value,
6688 nommu_save->new_env = new_env;
6689 nommu_save->old_vars = set_vars_and_save_old(new_env);
6692 if (argv_expanded) {
6693 argv = argv_expanded;
6695 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6697 nommu_save->argv = argv;
6700 dump_cmd_in_x_mode(argv);
6702 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6703 if (strchr(argv[0], '/') != NULL)
6707 /* Check if the command matches any of the builtins.
6708 * Depending on context, this might be redundant. But it's
6709 * easier to waste a few CPU cycles than it is to figure out
6710 * if this is one of those cases.
6713 /* On NOMMU, it is more expensive to re-execute shell
6714 * just in order to run echo or test builtin.
6715 * It's better to skip it here and run corresponding
6716 * non-builtin later. */
6717 const struct built_in_command *x;
6718 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6720 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6723 #if ENABLE_HUSH_FUNCTIONS
6724 /* Check if the command matches any functions */
6726 const struct function *funcp = find_function(argv[0]);
6728 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6733 #if ENABLE_FEATURE_SH_STANDALONE
6734 /* Check if the command matches any busybox applets */
6736 int a = find_applet_by_name(argv[0]);
6738 # if BB_MMU /* see above why on NOMMU it is not allowed */
6739 if (APPLET_IS_NOEXEC(a)) {
6740 /* Do not leak open fds from opened script files etc */
6741 close_all_FILE_list();
6742 debug_printf_exec("running applet '%s'\n", argv[0]);
6743 run_applet_no_and_exit(a, argv);
6746 /* Re-exec ourselves */
6747 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6748 /* Don't propagate SIG_IGN to the child */
6749 if (SPECIAL_JOBSTOP_SIGS != 0)
6750 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6751 execv(bb_busybox_exec_path, argv);
6752 /* If they called chroot or otherwise made the binary no longer
6753 * executable, fall through */
6758 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6761 execvp_or_die(argv);
6764 /* Called after [v]fork() in run_pipe
6766 static void pseudo_exec(nommu_save_t *nommu_save,
6767 struct command *command,
6768 char **argv_expanded) NORETURN;
6769 static void pseudo_exec(nommu_save_t *nommu_save,
6770 struct command *command,
6771 char **argv_expanded)
6773 if (command->argv) {
6774 pseudo_exec_argv(nommu_save, command->argv,
6775 command->assignment_cnt, argv_expanded);
6778 if (command->group) {
6779 /* Cases when we are here:
6782 * ... | ( list ) | ...
6783 * ... | { list } | ...
6787 debug_printf_exec("pseudo_exec: run_list\n");
6788 reset_traps_to_defaults();
6789 rcode = run_list(command->group);
6790 /* OK to leak memory by not calling free_pipe_list,
6791 * since this process is about to exit */
6794 re_execute_shell(&nommu_save->argv_from_re_execing,
6795 command->group_as_string,
6802 /* Case when we are here: ... | >file */
6803 debug_printf_exec("pseudo_exec'ed null command\n");
6804 _exit(EXIT_SUCCESS);
6808 static const char *get_cmdtext(struct pipe *pi)
6814 /* This is subtle. ->cmdtext is created only on first backgrounding.
6815 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6816 * On subsequent bg argv is trashed, but we won't use it */
6819 argv = pi->cmds[0].argv;
6820 if (!argv || !argv[0]) {
6821 pi->cmdtext = xzalloc(1);
6827 len += strlen(*argv) + 1;
6831 argv = pi->cmds[0].argv;
6833 len = strlen(*argv);
6834 memcpy(p, *argv, len);
6842 static void insert_bg_job(struct pipe *pi)
6844 struct pipe *job, **jobp;
6847 /* Linear search for the ID of the job to use */
6849 for (job = G.job_list; job; job = job->next)
6850 if (job->jobid >= pi->jobid)
6851 pi->jobid = job->jobid + 1;
6853 /* Add job to the list of running jobs */
6855 while ((job = *jobp) != NULL)
6857 job = *jobp = xmalloc(sizeof(*job));
6859 *job = *pi; /* physical copy */
6861 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6862 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6863 for (i = 0; i < pi->num_cmds; i++) {
6864 job->cmds[i].pid = pi->cmds[i].pid;
6865 /* all other fields are not used and stay zero */
6867 job->cmdtext = xstrdup(get_cmdtext(pi));
6869 if (G_interactive_fd)
6870 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6871 G.last_jobid = job->jobid;
6874 static void remove_bg_job(struct pipe *pi)
6876 struct pipe *prev_pipe;
6878 if (pi == G.job_list) {
6879 G.job_list = pi->next;
6881 prev_pipe = G.job_list;
6882 while (prev_pipe->next != pi)
6883 prev_pipe = prev_pipe->next;
6884 prev_pipe->next = pi->next;
6887 G.last_jobid = G.job_list->jobid;
6892 /* Remove a backgrounded job */
6893 static void delete_finished_bg_job(struct pipe *pi)
6900 /* Check to see if any processes have exited -- if they
6901 * have, figure out why and see if a job has completed */
6902 static int checkjobs(struct pipe *fg_pipe)
6912 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6914 attributes = WUNTRACED;
6915 if (fg_pipe == NULL)
6916 attributes |= WNOHANG;
6919 #if ENABLE_HUSH_FAST
6920 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6921 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6922 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6923 /* There was neither fork nor SIGCHLD since last waitpid */
6924 /* Avoid doing waitpid syscall if possible */
6925 if (!G.we_have_children) {
6929 if (fg_pipe == NULL) { /* is WNOHANG set? */
6930 /* We have children, but they did not exit
6931 * or stop yet (we saw no SIGCHLD) */
6934 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6938 /* Do we do this right?
6939 * bash-3.00# sleep 20 | false
6941 * [3]+ Stopped sleep 20 | false
6942 * bash-3.00# echo $?
6943 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6944 * [hush 1.14.0: yes we do it right]
6951 #if ENABLE_HUSH_FAST
6952 i = G.count_SIGCHLD;
6954 childpid = waitpid(-1, &status, attributes);
6955 if (childpid <= 0) {
6956 if (childpid && errno != ECHILD)
6957 bb_perror_msg("waitpid");
6958 #if ENABLE_HUSH_FAST
6959 else { /* Until next SIGCHLD, waitpid's are useless */
6960 G.we_have_children = (childpid == 0);
6961 G.handled_SIGCHLD = i;
6962 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6967 dead = WIFEXITED(status) || WIFSIGNALED(status);
6970 if (WIFSTOPPED(status))
6971 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6972 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6973 if (WIFSIGNALED(status))
6974 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6975 childpid, WTERMSIG(status), WEXITSTATUS(status));
6976 if (WIFEXITED(status))
6977 debug_printf_jobs("pid %d exited, exitcode %d\n",
6978 childpid, WEXITSTATUS(status));
6980 /* Were we asked to wait for fg pipe? */
6982 i = fg_pipe->num_cmds;
6984 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6985 if (fg_pipe->cmds[i].pid != childpid)
6989 fg_pipe->cmds[i].pid = 0;
6990 fg_pipe->alive_cmds--;
6991 ex = WEXITSTATUS(status);
6992 /* bash prints killer signal's name for *last*
6993 * process in pipe (prints just newline for SIGINT/SIGPIPE).
6994 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6996 if (WIFSIGNALED(status)) {
6997 int sig = WTERMSIG(status);
6998 if (i == fg_pipe->num_cmds-1)
6999 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7000 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7001 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7002 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7003 * Maybe we need to use sig | 128? */
7006 fg_pipe->cmds[i].cmd_exitcode = ex;
7008 fg_pipe->stopped_cmds++;
7010 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7011 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7012 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
7013 /* All processes in fg pipe have exited or stopped */
7014 i = fg_pipe->num_cmds;
7016 rcode = fg_pipe->cmds[i].cmd_exitcode;
7017 /* usually last process gives overall exitstatus,
7018 * but with "set -o pipefail", last *failed* process does */
7019 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7022 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
7023 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7024 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7025 * and "killall -STOP cat" */
7026 if (G_interactive_fd) {
7028 if (fg_pipe->alive_cmds != 0)
7029 insert_bg_job(fg_pipe);
7033 if (fg_pipe->alive_cmds == 0)
7036 /* There are still running processes in the fg pipe */
7037 goto wait_more; /* do waitpid again */
7039 /* it wasnt fg_pipe, look for process in bg pipes */
7043 /* We asked to wait for bg or orphaned children */
7044 /* No need to remember exitcode in this case */
7045 for (pi = G.job_list; pi; pi = pi->next) {
7046 for (i = 0; i < pi->num_cmds; i++) {
7047 if (pi->cmds[i].pid == childpid)
7048 goto found_pi_and_prognum;
7051 /* Happens when shell is used as init process (init=/bin/sh) */
7052 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7053 continue; /* do waitpid again */
7055 found_pi_and_prognum:
7058 pi->cmds[i].pid = 0;
7060 if (!pi->alive_cmds) {
7061 if (G_interactive_fd)
7062 printf(JOB_STATUS_FORMAT, pi->jobid,
7063 "Done", pi->cmdtext);
7064 delete_finished_bg_job(pi);
7071 } /* while (waitpid succeeds)... */
7077 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7080 int rcode = checkjobs(fg_pipe);
7081 if (G_saved_tty_pgrp) {
7082 /* Job finished, move the shell to the foreground */
7083 p = getpgrp(); /* our process group id */
7084 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7085 tcsetpgrp(G_interactive_fd, p);
7091 /* Start all the jobs, but don't wait for anything to finish.
7094 * Return code is normally -1, when the caller has to wait for children
7095 * to finish to determine the exit status of the pipe. If the pipe
7096 * is a simple builtin command, however, the action is done by the
7097 * time run_pipe returns, and the exit code is provided as the
7100 * Returns -1 only if started some children. IOW: we have to
7101 * mask out retvals of builtins etc with 0xff!
7103 * The only case when we do not need to [v]fork is when the pipe
7104 * is single, non-backgrounded, non-subshell command. Examples:
7105 * cmd ; ... { list } ; ...
7106 * cmd && ... { list } && ...
7107 * cmd || ... { list } || ...
7108 * If it is, then we can run cmd as a builtin, NOFORK,
7109 * or (if SH_STANDALONE) an applet, and we can run the { list }
7110 * with run_list. If it isn't one of these, we fork and exec cmd.
7112 * Cases when we must fork:
7113 * non-single: cmd | cmd
7114 * backgrounded: cmd & { list } &
7115 * subshell: ( list ) [&]
7117 #if !ENABLE_HUSH_MODE_X
7118 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7119 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7121 static int redirect_and_varexp_helper(char ***new_env_p,
7122 struct variable **old_vars_p,
7123 struct command *command,
7125 char **argv_expanded)
7127 /* setup_redirects acts on file descriptors, not FILEs.
7128 * This is perfect for work that comes after exec().
7129 * Is it really safe for inline use? Experimentally,
7130 * things seem to work. */
7131 int rcode = setup_redirects(command, squirrel);
7133 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7134 *new_env_p = new_env;
7135 dump_cmd_in_x_mode(new_env);
7136 dump_cmd_in_x_mode(argv_expanded);
7138 *old_vars_p = set_vars_and_save_old(new_env);
7142 static NOINLINE int run_pipe(struct pipe *pi)
7144 static const char *const null_ptr = NULL;
7148 struct command *command;
7149 char **argv_expanded;
7151 /* it is not always needed, but we aim to smaller code */
7152 int squirrel[] = { -1, -1, -1 };
7155 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7158 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7159 * Result should be 3 lines: q w e, qwe, q w e
7161 G.ifs = get_local_var_value("IFS");
7165 IF_HUSH_JOB(pi->pgrp = -1;)
7166 pi->stopped_cmds = 0;
7167 command = &pi->cmds[0];
7168 argv_expanded = NULL;
7170 if (pi->num_cmds != 1
7171 || pi->followup == PIPE_BG
7172 || command->cmd_type == CMD_SUBSHELL
7179 debug_printf_exec(": group:%p argv:'%s'\n",
7180 command->group, command->argv ? command->argv[0] : "NONE");
7182 if (command->group) {
7183 #if ENABLE_HUSH_FUNCTIONS
7184 if (command->cmd_type == CMD_FUNCDEF) {
7185 /* "executing" func () { list } */
7186 struct function *funcp;
7188 funcp = new_function(command->argv[0]);
7189 /* funcp->name is already set to argv[0] */
7190 funcp->body = command->group;
7192 funcp->body_as_string = command->group_as_string;
7193 command->group_as_string = NULL;
7195 command->group = NULL;
7196 command->argv[0] = NULL;
7197 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7198 funcp->parent_cmd = command;
7199 command->child_func = funcp;
7201 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7203 return EXIT_SUCCESS;
7207 debug_printf("non-subshell group\n");
7208 rcode = 1; /* exitcode if redir failed */
7209 if (setup_redirects(command, squirrel) == 0) {
7210 debug_printf_exec(": run_list\n");
7211 rcode = run_list(command->group) & 0xff;
7213 restore_redirects(squirrel);
7214 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7216 debug_printf_exec("run_pipe: return %d\n", rcode);
7220 argv = command->argv ? command->argv : (char **) &null_ptr;
7222 const struct built_in_command *x;
7223 #if ENABLE_HUSH_FUNCTIONS
7224 const struct function *funcp;
7228 char **new_env = NULL;
7229 struct variable *old_vars = NULL;
7231 if (argv[command->assignment_cnt] == NULL) {
7232 /* Assignments, but no command */
7233 /* Ensure redirects take effect (that is, create files).
7234 * Try "a=t >file" */
7235 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7236 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7237 /* Set shell variables */
7241 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7242 /* Do we need to flag set_local_var() errors?
7243 * "assignment to readonly var" and "putenv error"
7248 /* Redirect error sets $? to 1. Otherwise,
7249 * if evaluating assignment value set $?, retain it.
7250 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7252 rcode = G.last_exitcode;
7253 /* Exit, _skipping_ variable restoring code: */
7254 goto clean_up_and_ret0;
7256 #else /* Older, bigger, but more correct code */
7258 rcode = setup_redirects(command, squirrel);
7259 restore_redirects(squirrel);
7260 /* Set shell variables */
7262 bb_putchar_stderr('+');
7264 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7266 fprintf(stderr, " %s", p);
7267 debug_printf_exec("set shell var:'%s'->'%s'\n",
7269 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7270 /* Do we need to flag set_local_var() errors?
7271 * "assignment to readonly var" and "putenv error"
7276 bb_putchar_stderr('\n');
7277 /* Redirect error sets $? to 1. Otherwise,
7278 * if evaluating assignment value set $?, retain it.
7279 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7281 rcode = G.last_exitcode;
7282 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7284 debug_printf_exec("run_pipe: return %d\n", rcode);
7289 /* Expand the rest into (possibly) many strings each */
7290 #if ENABLE_HUSH_BASH_COMPAT
7291 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7292 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7296 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7299 /* if someone gives us an empty string: `cmd with empty output` */
7300 if (!argv_expanded[0]) {
7301 free(argv_expanded);
7303 return G.last_exitcode;
7306 x = find_builtin(argv_expanded[0]);
7307 #if ENABLE_HUSH_FUNCTIONS
7310 funcp = find_function(argv_expanded[0]);
7314 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7315 debug_printf("exec with redirects only\n");
7316 rcode = setup_redirects(command, NULL);
7317 /* rcode=1 can be if redir file can't be opened */
7318 goto clean_up_and_ret1;
7321 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7324 debug_printf_exec(": builtin '%s' '%s'...\n",
7325 x->b_cmd, argv_expanded[1]);
7327 rcode = x->b_function(argv_expanded) & 0xff;
7330 #if ENABLE_HUSH_FUNCTIONS
7332 # if ENABLE_HUSH_LOCAL
7333 struct variable **sv;
7334 sv = G.shadowed_vars_pp;
7335 G.shadowed_vars_pp = &old_vars;
7337 debug_printf_exec(": function '%s' '%s'...\n",
7338 funcp->name, argv_expanded[1]);
7339 rcode = run_function(funcp, argv_expanded) & 0xff;
7340 # if ENABLE_HUSH_LOCAL
7341 G.shadowed_vars_pp = sv;
7347 unset_vars(new_env);
7349 /* clean_up_and_ret0: */
7350 restore_redirects(squirrel);
7352 free(argv_expanded);
7353 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7355 debug_printf_exec("run_pipe return %d\n", rcode);
7359 if (ENABLE_FEATURE_SH_NOFORK) {
7360 int n = find_applet_by_name(argv_expanded[0]);
7361 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7362 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7364 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7365 argv_expanded[0], argv_expanded[1]);
7366 rcode = run_nofork_applet(n, argv_expanded);
7368 goto clean_up_and_ret;
7371 /* It is neither builtin nor applet. We must fork. */
7375 /* NB: argv_expanded may already be created, and that
7376 * might include `cmd` runs! Do not rerun it! We *must*
7377 * use argv_expanded if it's non-NULL */
7379 /* Going to fork a child per each pipe member */
7384 while (cmd_no < pi->num_cmds) {
7385 struct fd_pair pipefds;
7387 volatile nommu_save_t nommu_save;
7388 nommu_save.new_env = NULL;
7389 nommu_save.old_vars = NULL;
7390 nommu_save.argv = NULL;
7391 nommu_save.argv_from_re_execing = NULL;
7393 command = &pi->cmds[cmd_no];
7395 if (command->argv) {
7396 debug_printf_exec(": pipe member '%s' '%s'...\n",
7397 command->argv[0], command->argv[1]);
7399 debug_printf_exec(": pipe member with no argv\n");
7402 /* pipes are inserted between pairs of commands */
7405 if (cmd_no < pi->num_cmds)
7406 xpiped_pair(pipefds);
7408 command->pid = BB_MMU ? fork() : vfork();
7409 if (!command->pid) { /* child */
7411 disable_restore_tty_pgrp_on_exit();
7412 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7414 /* Every child adds itself to new process group
7415 * with pgid == pid_of_first_child_in_pipe */
7416 if (G.run_list_level == 1 && G_interactive_fd) {
7419 if (pgrp < 0) /* true for 1st process only */
7421 if (setpgid(0, pgrp) == 0
7422 && pi->followup != PIPE_BG
7423 && G_saved_tty_pgrp /* we have ctty */
7425 /* We do it in *every* child, not just first,
7427 tcsetpgrp(G_interactive_fd, pgrp);
7431 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7432 /* 1st cmd in backgrounded pipe
7433 * should have its stdin /dev/null'ed */
7435 if (open(bb_dev_null, O_RDONLY))
7436 xopen("/", O_RDONLY);
7438 xmove_fd(next_infd, 0);
7440 xmove_fd(pipefds.wr, 1);
7443 /* Like bash, explicit redirects override pipes,
7444 * and the pipe fd (fd#1) is available for dup'ing:
7445 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7446 * of cmd1 goes into pipe.
7448 if (setup_redirects(command, NULL)) {
7449 /* Happens when redir file can't be opened:
7450 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7452 * hush: can't open '/qwe/rty': No such file or directory
7454 * (echo BAR is not executed, it hits _exit(1) below)
7459 /* Stores to nommu_save list of env vars putenv'ed
7460 * (NOMMU, on MMU we don't need that) */
7461 /* cast away volatility... */
7462 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7463 /* pseudo_exec() does not return */
7466 /* parent or error */
7467 #if ENABLE_HUSH_FAST
7469 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7471 enable_restore_tty_pgrp_on_exit();
7473 /* Clean up after vforked child */
7474 free(nommu_save.argv);
7475 free(nommu_save.argv_from_re_execing);
7476 unset_vars(nommu_save.new_env);
7477 add_vars(nommu_save.old_vars);
7479 free(argv_expanded);
7480 argv_expanded = NULL;
7481 if (command->pid < 0) { /* [v]fork failed */
7482 /* Clearly indicate, was it fork or vfork */
7483 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7487 /* Second and next children need to know pid of first one */
7489 pi->pgrp = command->pid;
7495 if (cmd_no < pi->num_cmds)
7497 /* Pass read (output) pipe end to next iteration */
7498 next_infd = pipefds.rd;
7501 if (!pi->alive_cmds) {
7503 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7508 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7512 /* NB: called by pseudo_exec, and therefore must not modify any
7513 * global data until exec/_exit (we can be a child after vfork!) */
7514 static int run_list(struct pipe *pi)
7516 #if ENABLE_HUSH_CASE
7517 char *case_word = NULL;
7519 #if ENABLE_HUSH_LOOPS
7520 struct pipe *loop_top = NULL;
7521 char **for_lcur = NULL;
7522 char **for_list = NULL;
7524 smallint last_followup;
7526 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7527 smalluint cond_code = 0;
7529 enum { cond_code = 0 };
7532 smallint rword; /* RES_foo */
7533 smallint last_rword; /* ditto */
7536 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7539 #if ENABLE_HUSH_LOOPS
7540 /* Check syntax for "for" */
7543 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7544 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7546 /* current word is FOR or IN (BOLD in comments below) */
7547 if (cpipe->next == NULL) {
7548 syntax_error("malformed for");
7550 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7553 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7554 if (cpipe->next->res_word == RES_DO)
7556 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7557 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7558 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7560 syntax_error("malformed for");
7562 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7569 /* Past this point, all code paths should jump to ret: label
7570 * in order to return, no direct "return" statements please.
7571 * This helps to ensure that no memory is leaked. */
7579 last_rword = RES_XXXX;
7581 last_followup = PIPE_SEQ;
7582 rcode = G.last_exitcode;
7584 /* Go through list of pipes, (maybe) executing them. */
7585 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7589 IF_HAS_KEYWORDS(rword = pi->res_word;)
7590 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7591 rword, cond_code, last_rword);
7592 #if ENABLE_HUSH_LOOPS
7593 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7594 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7596 /* start of a loop: remember where loop starts */
7601 /* Still in the same "if...", "then..." or "do..." branch? */
7602 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7603 if ((rcode == 0 && last_followup == PIPE_OR)
7604 || (rcode != 0 && last_followup == PIPE_AND)
7606 /* It is "<true> || CMD" or "<false> && CMD"
7607 * and we should not execute CMD */
7608 debug_printf_exec("skipped cmd because of || or &&\n");
7609 last_followup = pi->followup;
7610 goto dont_check_jobs_but_continue;
7613 last_followup = pi->followup;
7614 IF_HAS_KEYWORDS(last_rword = rword;)
7617 if (rword == RES_THEN) {
7618 /* if false; then ... fi has exitcode 0! */
7619 G.last_exitcode = rcode = EXIT_SUCCESS;
7620 /* "if <false> THEN cmd": skip cmd */
7624 if (rword == RES_ELSE || rword == RES_ELIF) {
7625 /* "if <true> then ... ELSE/ELIF cmd":
7626 * skip cmd and all following ones */
7631 #if ENABLE_HUSH_LOOPS
7632 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7634 /* first loop through for */
7636 static const char encoded_dollar_at[] ALIGN1 = {
7637 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7638 }; /* encoded representation of "$@" */
7639 static const char *const encoded_dollar_at_argv[] = {
7640 encoded_dollar_at, NULL
7641 }; /* argv list with one element: "$@" */
7644 vals = (char**)encoded_dollar_at_argv;
7645 if (pi->next->res_word == RES_IN) {
7646 /* if no variable values after "in" we skip "for" */
7647 if (!pi->next->cmds[0].argv) {
7648 G.last_exitcode = rcode = EXIT_SUCCESS;
7649 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7652 vals = pi->next->cmds[0].argv;
7653 } /* else: "for var; do..." -> assume "$@" list */
7654 /* create list of variable values */
7655 debug_print_strings("for_list made from", vals);
7656 for_list = expand_strvec_to_strvec(vals);
7657 for_lcur = for_list;
7658 debug_print_strings("for_list", for_list);
7661 /* "for" loop is over, clean up */
7667 /* Insert next value from for_lcur */
7668 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7669 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7672 if (rword == RES_IN) {
7673 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7675 if (rword == RES_DONE) {
7676 continue; /* "done" has no cmds too */
7679 #if ENABLE_HUSH_CASE
7680 if (rword == RES_CASE) {
7681 case_word = expand_strvec_to_string(pi->cmds->argv);
7684 if (rword == RES_MATCH) {
7687 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7689 /* all prev words didn't match, does this one match? */
7690 argv = pi->cmds->argv;
7692 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7693 /* TODO: which FNM_xxx flags to use? */
7694 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7696 if (cond_code == 0) { /* match! we will execute this branch */
7697 free(case_word); /* make future "word)" stop */
7705 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7707 continue; /* not matched yet, skip this pipe */
7710 /* Just pressing <enter> in shell should check for jobs.
7711 * OTOH, in non-interactive shell this is useless
7712 * and only leads to extra job checks */
7713 if (pi->num_cmds == 0) {
7714 if (G_interactive_fd)
7715 goto check_jobs_and_continue;
7719 /* After analyzing all keywords and conditions, we decided
7720 * to execute this pipe. NB: have to do checkjobs(NULL)
7721 * after run_pipe to collect any background children,
7722 * even if list execution is to be stopped. */
7723 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7726 #if ENABLE_HUSH_LOOPS
7727 G.flag_break_continue = 0;
7729 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7731 /* We ran a builtin, function, or group.
7732 * rcode is already known
7733 * and we don't need to wait for anything. */
7734 G.last_exitcode = rcode;
7735 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7736 check_and_run_traps();
7737 #if ENABLE_HUSH_LOOPS
7738 /* Was it "break" or "continue"? */
7739 if (G.flag_break_continue) {
7740 smallint fbc = G.flag_break_continue;
7741 /* We might fall into outer *loop*,
7742 * don't want to break it too */
7744 G.depth_break_continue--;
7745 if (G.depth_break_continue == 0)
7746 G.flag_break_continue = 0;
7747 /* else: e.g. "continue 2" should *break* once, *then* continue */
7748 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7749 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7753 /* "continue": simulate end of loop */
7758 #if ENABLE_HUSH_FUNCTIONS
7759 if (G.flag_return_in_progress == 1) {
7764 } else if (pi->followup == PIPE_BG) {
7765 /* What does bash do with attempts to background builtins? */
7766 /* even bash 3.2 doesn't do that well with nested bg:
7767 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7768 * I'm NOT treating inner &'s as jobs */
7769 check_and_run_traps();
7771 if (G.run_list_level == 1)
7774 /* Last command's pid goes to $! */
7775 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7776 G.last_exitcode = rcode = EXIT_SUCCESS;
7777 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7780 if (G.run_list_level == 1 && G_interactive_fd) {
7781 /* Waits for completion, then fg's main shell */
7782 rcode = checkjobs_and_fg_shell(pi);
7783 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7784 check_and_run_traps();
7787 { /* This one just waits for completion */
7788 rcode = checkjobs(pi);
7789 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7790 check_and_run_traps();
7792 G.last_exitcode = rcode;
7796 /* Analyze how result affects subsequent commands */
7798 if (rword == RES_IF || rword == RES_ELIF)
7801 check_jobs_and_continue:
7803 dont_check_jobs_but_continue: ;
7804 #if ENABLE_HUSH_LOOPS
7805 /* Beware of "while false; true; do ..."! */
7807 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
7808 /* check for RES_DONE is needed for "while ...; do \n done" case */
7810 if (rword == RES_WHILE) {
7812 /* "while false; do...done" - exitcode 0 */
7813 G.last_exitcode = rcode = EXIT_SUCCESS;
7814 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7818 if (rword == RES_UNTIL) {
7820 debug_printf_exec(": until expr is true: breaking\n");
7831 #if ENABLE_HUSH_LOOPS
7836 #if ENABLE_HUSH_CASE
7840 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7844 /* Select which version we will use */
7845 static int run_and_free_list(struct pipe *pi)
7848 debug_printf_exec("run_and_free_list entered\n");
7849 if (!G.o_opt[OPT_O_NOEXEC]) {
7850 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7851 rcode = run_list(pi);
7853 /* free_pipe_list has the side effect of clearing memory.
7854 * In the long run that function can be merged with run_list,
7855 * but doing that now would hobble the debugging effort. */
7857 debug_printf_exec("run_and_free_list return %d\n", rcode);
7862 static void install_sighandlers(unsigned mask)
7864 sighandler_t old_handler;
7866 while ((mask >>= 1) != 0) {
7870 old_handler = install_sighandler(sig, pick_sighandler(sig));
7871 /* POSIX allows shell to re-enable SIGCHLD
7872 * even if it was SIG_IGN on entry.
7873 * Therefore we skip IGN check for it:
7877 if (old_handler == SIG_IGN) {
7878 /* oops... restore back to IGN, and record this fact */
7879 install_sighandler(sig, old_handler);
7881 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7883 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7888 /* Called a few times only (or even once if "sh -c") */
7889 static void install_special_sighandlers(void)
7893 /* Which signals are shell-special? */
7894 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
7895 if (G_interactive_fd) {
7896 mask |= SPECIAL_INTERACTIVE_SIGS;
7897 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7898 mask |= SPECIAL_JOBSTOP_SIGS;
7900 /* Careful, do not re-install handlers we already installed */
7901 if (G.special_sig_mask != mask) {
7902 unsigned diff = mask & ~G.special_sig_mask;
7903 G.special_sig_mask = mask;
7904 install_sighandlers(diff);
7910 /* Set handlers to restore tty pgrp and exit */
7911 static void install_fatal_sighandlers(void)
7915 /* We will restore tty pgrp on these signals */
7917 + (1 << SIGILL ) * HUSH_DEBUG
7918 + (1 << SIGFPE ) * HUSH_DEBUG
7919 + (1 << SIGBUS ) * HUSH_DEBUG
7920 + (1 << SIGSEGV) * HUSH_DEBUG
7921 + (1 << SIGTRAP) * HUSH_DEBUG
7923 /* bash 3.2 seems to handle these just like 'fatal' ones */
7926 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
7927 * if we aren't interactive... but in this case
7928 * we never want to restore pgrp on exit, and this fn is not called
7930 /*+ (1 << SIGHUP )*/
7931 /*+ (1 << SIGTERM)*/
7932 /*+ (1 << SIGINT )*/
7934 G_fatal_sig_mask = mask;
7936 install_sighandlers(mask);
7940 static int set_mode(int state, char mode, const char *o_opt)
7945 G.o_opt[OPT_O_NOEXEC] = state;
7948 IF_HUSH_MODE_X(G_x_mode = state;)
7952 /* "set -+o" without parameter.
7953 * in bash, set -o produces this output:
7957 * We always use the second form.
7959 const char *p = o_opt_strings;
7962 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
7968 idx = index_in_strings(o_opt_strings, o_opt);
7970 G.o_opt[idx] = state;
7974 return EXIT_FAILURE;
7976 return EXIT_SUCCESS;
7979 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7980 int hush_main(int argc, char **argv)
7983 OPT_login = (1 << 0),
7987 unsigned builtin_argc;
7989 struct variable *cur_var;
7990 struct variable *shell_ver;
7993 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
7994 G.last_exitcode = EXIT_SUCCESS;
7996 #if ENABLE_HUSH_FAST
7997 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8000 G.argv0_for_re_execing = argv[0];
8002 /* Deal with HUSH_VERSION */
8003 shell_ver = xzalloc(sizeof(*shell_ver));
8004 shell_ver->flg_export = 1;
8005 shell_ver->flg_read_only = 1;
8006 /* Code which handles ${var<op>...} needs writable values for all variables,
8007 * therefore we xstrdup: */
8008 shell_ver->varstr = xstrdup(hush_version_str);
8009 /* Create shell local variables from the values
8010 * currently living in the environment */
8011 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8012 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8013 G.top_var = shell_ver;
8014 cur_var = G.top_var;
8017 char *value = strchr(*e, '=');
8018 if (value) { /* paranoia */
8019 cur_var->next = xzalloc(sizeof(*cur_var));
8020 cur_var = cur_var->next;
8021 cur_var->varstr = *e;
8022 cur_var->max_len = strlen(*e);
8023 cur_var->flg_export = 1;
8027 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8028 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8029 putenv(shell_ver->varstr);
8032 set_pwd_var(/*exp:*/ 1);
8034 #if ENABLE_HUSH_BASH_COMPAT
8035 /* Set (but not export) HOSTNAME unless already set */
8036 if (!get_local_var_value("HOSTNAME")) {
8039 set_local_var_from_halves("HOSTNAME", uts.nodename);
8041 /* bash also exports SHLVL and _,
8042 * and sets (but doesn't export) the following variables:
8044 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8045 * BASH_VERSION='3.2.0(1)-release'
8047 * MACHTYPE=i386-pc-linux-gnu
8049 * PPID=<NNNNN> - we also do it elsewhere
8060 * PIPESTATUS=([0]="0")
8061 * HISTFILE=/<xxx>/.bash_history
8065 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8067 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8078 #if ENABLE_FEATURE_EDITING
8079 G.line_input_state = new_line_input_t(FOR_SHELL);
8082 /* Initialize some more globals to non-zero values */
8083 cmdedit_update_prompt();
8085 die_func = restore_ttypgrp_and__exit;
8087 /* Shell is non-interactive at first. We need to call
8088 * install_special_sighandlers() if we are going to execute "sh <script>",
8089 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8090 * If we later decide that we are interactive, we run install_special_sighandlers()
8091 * in order to intercept (more) signals.
8095 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8096 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8099 opt = getopt(argc, argv, "+c:xinsl"
8102 # if ENABLE_HUSH_FUNCTIONS
8112 * sh ... -c 'script'
8113 * sh ... -c 'script' ARG0 [ARG1...]
8114 * On NOMMU, if builtin_argc != 0,
8115 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8116 * "" needs to be replaced with NULL
8117 * and BARGV vector fed to builtin function.
8118 * Note: the form without ARG0 never happens:
8119 * sh ... -c 'builtin' BARGV... ""
8122 G.root_pid = getpid();
8123 G.root_ppid = getppid();
8125 G.global_argv = argv + optind;
8126 G.global_argc = argc - optind;
8128 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8129 const struct built_in_command *x;
8131 install_special_sighandlers();
8132 x = find_builtin(optarg);
8133 if (x) { /* paranoia */
8134 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8135 G.global_argv += builtin_argc;
8136 G.global_argv[-1] = NULL; /* replace "" */
8138 G.last_exitcode = x->b_function(argv + optind - 1);
8142 if (!G.global_argv[0]) {
8143 /* -c 'script' (no params): prevent empty $0 */
8144 G.global_argv--; /* points to argv[i] of 'script' */
8145 G.global_argv[0] = argv[0];
8147 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8148 install_special_sighandlers();
8149 parse_and_run_string(optarg);
8152 /* Well, we cannot just declare interactiveness,
8153 * we have to have some stuff (ctty, etc) */
8154 /* G_interactive_fd++; */
8157 /* "-s" means "read from stdin", but this is how we always
8158 * operate, so simply do nothing here. */
8164 case '<': /* "big heredoc" support */
8165 full_write1_str(optarg);
8168 unsigned long long empty_trap_mask;
8170 G.root_pid = bb_strtou(optarg, &optarg, 16);
8172 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8174 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8176 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8178 builtin_argc = bb_strtou(optarg, &optarg, 16);
8180 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8181 if (empty_trap_mask != 0) {
8183 install_special_sighandlers();
8184 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8185 for (sig = 1; sig < NSIG; sig++) {
8186 if (empty_trap_mask & (1LL << sig)) {
8187 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8188 install_sighandler(sig, SIG_IGN);
8192 # if ENABLE_HUSH_LOOPS
8194 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8200 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8202 # if ENABLE_HUSH_FUNCTIONS
8204 struct function *funcp = new_function(optarg);
8205 /* funcp->name is already set to optarg */
8206 /* funcp->body is set to NULL. It's a special case. */
8207 funcp->body_as_string = argv[optind];
8215 if (set_mode(1, opt, NULL) == 0) /* no error */
8219 fprintf(stderr, "Usage: sh [FILE]...\n"
8220 " or: sh -c command [args]...\n\n");
8226 } /* option parsing loop */
8228 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8229 G.global_argc = argc - (optind - 1);
8230 G.global_argv = argv + (optind - 1);
8231 G.global_argv[0] = argv[0];
8234 G.root_pid = getpid();
8235 G.root_ppid = getppid();
8238 /* If we are login shell... */
8239 if (flags & OPT_login) {
8241 debug_printf("sourcing /etc/profile\n");
8242 input = fopen_for_read("/etc/profile");
8243 if (input != NULL) {
8244 remember_FILE(input);
8245 install_special_sighandlers();
8246 parse_and_run_file(input);
8247 fclose_and_forget(input);
8249 /* bash: after sourcing /etc/profile,
8250 * tries to source (in the given order):
8251 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8252 * stopping on first found. --noprofile turns this off.
8253 * bash also sources ~/.bash_logout on exit.
8254 * If called as sh, skips .bash_XXX files.
8258 if (G.global_argv[1]) {
8261 * "bash <script>" (which is never interactive (unless -i?))
8262 * sources $BASH_ENV here (without scanning $PATH).
8263 * If called as sh, does the same but with $ENV.
8267 debug_printf("running script '%s'\n", G.global_argv[0]);
8268 input = xfopen_for_read(G.global_argv[0]);
8269 remember_FILE(input);
8270 install_special_sighandlers();
8271 parse_and_run_file(input);
8272 #if ENABLE_FEATURE_CLEAN_UP
8273 fclose_and_forget(input);
8278 /* Up to here, shell was non-interactive. Now it may become one.
8279 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8282 /* A shell is interactive if the '-i' flag was given,
8283 * or if all of the following conditions are met:
8285 * no arguments remaining or the -s flag given
8286 * standard input is a terminal
8287 * standard output is a terminal
8288 * Refer to Posix.2, the description of the 'sh' utility.
8291 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8292 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8293 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8294 if (G_saved_tty_pgrp < 0)
8295 G_saved_tty_pgrp = 0;
8297 /* try to dup stdin to high fd#, >= 255 */
8298 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8299 if (G_interactive_fd < 0) {
8300 /* try to dup to any fd */
8301 G_interactive_fd = dup(STDIN_FILENO);
8302 if (G_interactive_fd < 0) {
8304 G_interactive_fd = 0;
8305 G_saved_tty_pgrp = 0;
8308 // TODO: track & disallow any attempts of user
8309 // to (inadvertently) close/redirect G_interactive_fd
8311 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8312 if (G_interactive_fd) {
8313 close_on_exec_on(G_interactive_fd);
8315 if (G_saved_tty_pgrp) {
8316 /* If we were run as 'hush &', sleep until we are
8317 * in the foreground (tty pgrp == our pgrp).
8318 * If we get started under a job aware app (like bash),
8319 * make sure we are now in charge so we don't fight over
8320 * who gets the foreground */
8322 pid_t shell_pgrp = getpgrp();
8323 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8324 if (G_saved_tty_pgrp == shell_pgrp)
8326 /* send TTIN to ourself (should stop us) */
8327 kill(- shell_pgrp, SIGTTIN);
8331 /* Install more signal handlers */
8332 install_special_sighandlers();
8334 if (G_saved_tty_pgrp) {
8335 /* Set other signals to restore saved_tty_pgrp */
8336 install_fatal_sighandlers();
8337 /* Put ourselves in our own process group
8338 * (bash, too, does this only if ctty is available) */
8339 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8340 /* Grab control of the terminal */
8341 tcsetpgrp(G_interactive_fd, getpid());
8343 enable_restore_tty_pgrp_on_exit();
8345 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8347 const char *hp = get_local_var_value("HISTFILE");
8349 hp = get_local_var_value("HOME");
8351 hp = concat_path_file(hp, ".hush_history");
8356 G.line_input_state->hist_file = hp;
8357 //set_local_var(xasprintf("HISTFILE=%s", ...));
8359 # if ENABLE_FEATURE_SH_HISTFILESIZE
8360 hp = get_local_var_value("HISTFILESIZE");
8361 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8366 install_special_sighandlers();
8368 #elif ENABLE_HUSH_INTERACTIVE
8369 /* No job control compiled in, only prompt/line editing */
8370 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8371 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8372 if (G_interactive_fd < 0) {
8373 /* try to dup to any fd */
8374 G_interactive_fd = dup(STDIN_FILENO);
8375 if (G_interactive_fd < 0)
8377 G_interactive_fd = 0;
8380 if (G_interactive_fd) {
8381 close_on_exec_on(G_interactive_fd);
8383 install_special_sighandlers();
8385 /* We have interactiveness code disabled */
8386 install_special_sighandlers();
8389 * if interactive but not a login shell, sources ~/.bashrc
8390 * (--norc turns this off, --rcfile <file> overrides)
8393 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8394 /* note: ash and hush share this string */
8395 printf("\n\n%s %s\n"
8396 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8399 "hush - the humble shell"
8403 parse_and_run_file(stdin);
8406 hush_exit(G.last_exitcode);
8411 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8412 int msh_main(int argc, char **argv)
8414 //bb_error_msg("msh is deprecated, please use hush instead");
8415 return hush_main(argc, argv);
8423 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8428 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8435 return applet_main_func(argc, argv - argc);
8438 static int FAST_FUNC builtin_test(char **argv)
8440 return run_applet_main(argv, test_main);
8443 static int FAST_FUNC builtin_echo(char **argv)
8445 return run_applet_main(argv, echo_main);
8449 static int FAST_FUNC builtin_printf(char **argv)
8451 return run_applet_main(argv, printf_main);
8455 static char **skip_dash_dash(char **argv)
8458 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8463 static int FAST_FUNC builtin_eval(char **argv)
8465 int rcode = EXIT_SUCCESS;
8467 argv = skip_dash_dash(argv);
8469 char *str = expand_strvec_to_string(argv);
8471 * eval "echo Hi; done" ("done" is syntax error):
8472 * "echo Hi" will not execute too.
8474 parse_and_run_string(str);
8476 rcode = G.last_exitcode;
8481 static int FAST_FUNC builtin_cd(char **argv)
8485 argv = skip_dash_dash(argv);
8487 if (newdir == NULL) {
8488 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8489 * bash says "bash: cd: HOME not set" and does nothing
8492 const char *home = get_local_var_value("HOME");
8493 newdir = home ? home : "/";
8495 if (chdir(newdir)) {
8496 /* Mimic bash message exactly */
8497 bb_perror_msg("cd: %s", newdir);
8498 return EXIT_FAILURE;
8500 /* Read current dir (get_cwd(1) is inside) and set PWD.
8501 * Note: do not enforce exporting. If PWD was unset or unexported,
8502 * set it again, but do not export. bash does the same.
8504 set_pwd_var(/*exp:*/ 0);
8505 return EXIT_SUCCESS;
8508 static int FAST_FUNC builtin_exec(char **argv)
8510 argv = skip_dash_dash(argv);
8511 if (argv[0] == NULL)
8512 return EXIT_SUCCESS; /* bash does this */
8514 /* Careful: we can end up here after [v]fork. Do not restore
8515 * tty pgrp then, only top-level shell process does that */
8516 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8517 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8519 /* TODO: if exec fails, bash does NOT exit! We do.
8520 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8521 * and tcsetpgrp, and this is inherently racy.
8523 execvp_or_die(argv);
8526 static int FAST_FUNC builtin_exit(char **argv)
8528 debug_printf_exec("%s()\n", __func__);
8530 /* interactive bash:
8531 * # trap "echo EEE" EXIT
8534 * There are stopped jobs.
8535 * (if there are _stopped_ jobs, running ones don't count)
8538 * EEE (then bash exits)
8540 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8543 /* note: EXIT trap is run by hush_exit */
8544 argv = skip_dash_dash(argv);
8545 if (argv[0] == NULL)
8546 hush_exit(G.last_exitcode);
8547 /* mimic bash: exit 123abc == exit 255 + error msg */
8548 xfunc_error_retval = 255;
8549 /* bash: exit -2 == exit 254, no error msg */
8550 hush_exit(xatoi(argv[0]) & 0xff);
8553 static void print_escaped(const char *s)
8558 const char *p = strchrnul(s, '\'');
8559 /* print 'xxxx', possibly just '' */
8560 printf("'%.*s'", (int)(p - s), s);
8565 /* s points to '; print "'''...'''" */
8567 do putchar('\''); while (*++s == '\'');
8572 #if !ENABLE_HUSH_LOCAL
8573 #define helper_export_local(argv, exp, lvl) \
8574 helper_export_local(argv, exp)
8576 static void helper_export_local(char **argv, int exp, int lvl)
8580 char *name_end = strchrnul(name, '=');
8582 /* So far we do not check that name is valid (TODO?) */
8584 if (*name_end == '\0') {
8585 struct variable *var, **vpp;
8587 vpp = get_ptr_to_local_var(name, name_end - name);
8588 var = vpp ? *vpp : NULL;
8590 if (exp == -1) { /* unexporting? */
8591 /* export -n NAME (without =VALUE) */
8593 var->flg_export = 0;
8594 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8596 } /* else: export -n NOT_EXISTING_VAR: no-op */
8599 if (exp == 1) { /* exporting? */
8600 /* export NAME (without =VALUE) */
8602 var->flg_export = 1;
8603 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8604 putenv(var->varstr);
8608 /* Exporting non-existing variable.
8609 * bash does not put it in environment,
8610 * but remembers that it is exported,
8611 * and does put it in env when it is set later.
8612 * We just set it to "" and export. */
8613 /* Or, it's "local NAME" (without =VALUE).
8614 * bash sets the value to "". */
8615 name = xasprintf("%s=", name);
8617 /* (Un)exporting/making local NAME=VALUE */
8618 name = xstrdup(name);
8620 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8624 static int FAST_FUNC builtin_export(char **argv)
8626 unsigned opt_unexport;
8628 #if ENABLE_HUSH_EXPORT_N
8629 /* "!": do not abort on errors */
8630 opt_unexport = getopt32(argv, "!n");
8631 if (opt_unexport == (uint32_t)-1)
8632 return EXIT_FAILURE;
8639 if (argv[0] == NULL) {
8646 /* ash emits: export VAR='VAL'
8647 * bash: declare -x VAR="VAL"
8648 * we follow ash example */
8649 const char *s = *e++;
8650 const char *p = strchr(s, '=');
8652 if (!p) /* wtf? take next variable */
8655 printf("export %.*s", (int)(p - s) + 1, s);
8656 print_escaped(p + 1);
8660 /*fflush_all(); - done after each builtin anyway */
8662 return EXIT_SUCCESS;
8665 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8667 return EXIT_SUCCESS;
8670 #if ENABLE_HUSH_LOCAL
8671 static int FAST_FUNC builtin_local(char **argv)
8673 if (G.func_nest_level == 0) {
8674 bb_error_msg("%s: not in a function", argv[0]);
8675 return EXIT_FAILURE; /* bash compat */
8677 helper_export_local(argv, 0, G.func_nest_level);
8678 return EXIT_SUCCESS;
8682 static int FAST_FUNC builtin_trap(char **argv)
8688 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8693 /* No args: print all trapped */
8694 for (i = 0; i < NSIG; ++i) {
8697 print_escaped(G.traps[i]);
8698 /* note: bash adds "SIG", but only if invoked
8699 * as "bash". If called as "sh", or if set -o posix,
8700 * then it prints short signal names.
8701 * We are printing short names: */
8702 printf(" %s\n", get_signame(i));
8705 /*fflush_all(); - done after each builtin anyway */
8706 return EXIT_SUCCESS;
8710 /* If first arg is a number: reset all specified signals */
8711 sig = bb_strtou(*argv, NULL, 10);
8717 sighandler_t handler;
8719 sig = get_signum(*argv++);
8720 if (sig < 0 || sig >= NSIG) {
8722 /* Mimic bash message exactly */
8723 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8728 G.traps[sig] = xstrdup(new_cmd);
8730 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8731 get_signame(sig), sig, G.traps[sig]);
8733 /* There is no signal for 0 (EXIT) */
8738 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
8740 /* We are removing trap handler */
8741 handler = pick_sighandler(sig);
8742 install_sighandler(sig, handler);
8747 if (!argv[1]) { /* no second arg */
8748 bb_error_msg("trap: invalid arguments");
8749 return EXIT_FAILURE;
8752 /* First arg is "-": reset all specified to default */
8753 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8754 /* Everything else: set arg as signal handler
8755 * (includes "" case, which ignores signal) */
8756 if (argv[0][0] == '-') {
8757 if (argv[0][1] == '\0') { /* "-" */
8758 /* new_cmd remains NULL: "reset these sigs" */
8761 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8764 /* else: "-something", no special meaning */
8769 goto process_sig_list;
8772 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8773 static int FAST_FUNC builtin_type(char **argv)
8775 int ret = EXIT_SUCCESS;
8781 if (0) {} /* make conditional compile easier below */
8782 /*else if (find_alias(*argv))
8783 type = "an alias";*/
8784 #if ENABLE_HUSH_FUNCTIONS
8785 else if (find_function(*argv))
8786 type = "a function";
8788 else if (find_builtin(*argv))
8789 type = "a shell builtin";
8790 else if ((path = find_in_path(*argv)) != NULL)
8793 bb_error_msg("type: %s: not found", *argv);
8798 printf("%s is %s\n", *argv, type);
8806 /* built-in 'fg' and 'bg' handler */
8807 static int FAST_FUNC builtin_fg_bg(char **argv)
8812 if (!G_interactive_fd)
8813 return EXIT_FAILURE;
8815 /* If they gave us no args, assume they want the last backgrounded task */
8817 for (pi = G.job_list; pi; pi = pi->next) {
8818 if (pi->jobid == G.last_jobid) {
8822 bb_error_msg("%s: no current job", argv[0]);
8823 return EXIT_FAILURE;
8825 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8826 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8827 return EXIT_FAILURE;
8829 for (pi = G.job_list; pi; pi = pi->next) {
8830 if (pi->jobid == jobnum) {
8834 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8835 return EXIT_FAILURE;
8837 /* TODO: bash prints a string representation
8838 * of job being foregrounded (like "sleep 1 | cat") */
8839 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8840 /* Put the job into the foreground. */
8841 tcsetpgrp(G_interactive_fd, pi->pgrp);
8844 /* Restart the processes in the job */
8845 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8846 for (i = 0; i < pi->num_cmds; i++) {
8847 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8849 pi->stopped_cmds = 0;
8851 i = kill(- pi->pgrp, SIGCONT);
8853 if (errno == ESRCH) {
8854 delete_finished_bg_job(pi);
8855 return EXIT_SUCCESS;
8857 bb_perror_msg("kill (SIGCONT)");
8860 if (argv[0][0] == 'f') {
8862 return checkjobs_and_fg_shell(pi);
8864 return EXIT_SUCCESS;
8868 #if ENABLE_HUSH_HELP
8869 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8871 const struct built_in_command *x;
8874 "Built-in commands:\n"
8875 "------------------\n");
8876 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8878 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8881 return EXIT_SUCCESS;
8885 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
8886 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8888 show_history(G.line_input_state);
8889 return EXIT_SUCCESS;
8894 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8897 const char *status_string;
8899 for (job = G.job_list; job; job = job->next) {
8900 if (job->alive_cmds == job->stopped_cmds)
8901 status_string = "Stopped";
8903 status_string = "Running";
8905 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8907 return EXIT_SUCCESS;
8912 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8917 # ifdef M_TRIM_THRESHOLD
8918 /* Optional. Reduces probability of false positives */
8921 /* Crude attempt to find where "free memory" starts,
8922 * sans fragmentation. */
8924 l = (unsigned long)p;
8927 if (l < (unsigned long)p) l = (unsigned long)p;
8930 if (!G.memleak_value)
8931 G.memleak_value = l;
8933 l -= G.memleak_value;
8940 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8945 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8948 return EXIT_SUCCESS;
8951 /* Interruptibility of read builtin in bash
8952 * (tested on bash-4.2.8 by sending signals (not by ^C)):
8954 * Empty trap makes read ignore corresponding signal, for any signal.
8957 * - terminates non-interactive shell;
8958 * - interrupts read in interactive shell;
8959 * if it has non-empty trap:
8960 * - executes trap and returns to command prompt in interactive shell;
8961 * - executes trap and returns to read in non-interactive shell;
8963 * - is ignored (does not interrupt) read in interactive shell;
8964 * - terminates non-interactive shell;
8965 * if it has non-empty trap:
8966 * - executes trap and returns to read;
8968 * - terminates shell (regardless of interactivity);
8969 * if it has non-empty trap:
8970 * - executes trap and returns to read;
8972 static int FAST_FUNC builtin_read(char **argv)
8982 /* "!": do not abort on errors.
8983 * Option string must start with "sr" to match BUILTIN_READ_xxx
8985 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8986 if (read_flags == (uint32_t)-1)
8987 return EXIT_FAILURE;
8989 ifs = get_local_var_value("IFS"); /* can be NULL */
8992 r = shell_builtin_read(set_local_var_from_halves,
9002 if ((uintptr_t)r == 1 && errno == EINTR) {
9003 unsigned sig = check_and_run_traps();
9004 if (sig && sig != SIGINT)
9008 if ((uintptr_t)r > 1) {
9009 bb_error_msg("%s", r);
9010 r = (char*)(uintptr_t)1;
9013 return (uintptr_t)r;
9016 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9017 * built-in 'set' handler
9019 * set [-abCefhmnuvx] [-o option] [argument...]
9020 * set [+abCefhmnuvx] [+o option] [argument...]
9021 * set -- [argument...]
9024 * Implementations shall support the options in both their hyphen and
9025 * plus-sign forms. These options can also be specified as options to sh.
9027 * Write out all variables and their values: set
9028 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9029 * Turn on the -x and -v options: set -xv
9030 * Unset all positional parameters: set --
9031 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9032 * Set the positional parameters to the expansion of x, even if x expands
9033 * with a leading '-' or '+': set -- $x
9035 * So far, we only support "set -- [argument...]" and some of the short names.
9037 static int FAST_FUNC builtin_set(char **argv)
9040 char **pp, **g_argv;
9041 char *arg = *++argv;
9045 for (e = G.top_var; e; e = e->next)
9047 return EXIT_SUCCESS;
9051 if (strcmp(arg, "--") == 0) {
9055 if (arg[0] != '+' && arg[0] != '-')
9057 for (n = 1; arg[n]; ++n) {
9058 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9060 if (arg[n] == 'o' && argv[1])
9063 } while ((arg = *++argv) != NULL);
9064 /* Now argv[0] is 1st argument */
9067 return EXIT_SUCCESS;
9070 /* NB: G.global_argv[0] ($0) is never freed/changed */
9071 g_argv = G.global_argv;
9072 if (G.global_args_malloced) {
9078 G.global_args_malloced = 1;
9079 pp = xzalloc(sizeof(pp[0]) * 2);
9080 pp[0] = g_argv[0]; /* retain $0 */
9083 /* This realloc's G.global_argv */
9084 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9091 return EXIT_SUCCESS;
9093 /* Nothing known, so abort */
9095 bb_error_msg("set: %s: invalid option", arg);
9096 return EXIT_FAILURE;
9099 static int FAST_FUNC builtin_shift(char **argv)
9102 argv = skip_dash_dash(argv);
9106 if (n >= 0 && n < G.global_argc) {
9107 if (G.global_args_malloced) {
9110 free(G.global_argv[m++]);
9113 memmove(&G.global_argv[1], &G.global_argv[n+1],
9114 G.global_argc * sizeof(G.global_argv[0]));
9115 return EXIT_SUCCESS;
9117 return EXIT_FAILURE;
9120 static int FAST_FUNC builtin_source(char **argv)
9122 char *arg_path, *filename;
9125 #if ENABLE_HUSH_FUNCTIONS
9129 argv = skip_dash_dash(argv);
9132 /* bash says: "bash: .: filename argument required" */
9133 return 2; /* bash compat */
9136 if (!strchr(filename, '/')) {
9137 arg_path = find_in_path(filename);
9139 filename = arg_path;
9141 input = remember_FILE(fopen_or_warn(filename, "r"));
9144 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9145 /* POSIX: non-interactive shell should abort here,
9146 * not merely fail. So far no one complained :)
9148 return EXIT_FAILURE;
9151 #if ENABLE_HUSH_FUNCTIONS
9152 sv_flg = G.flag_return_in_progress;
9153 /* "we are inside sourced file, ok to use return" */
9154 G.flag_return_in_progress = -1;
9157 save_and_replace_G_args(&sv, argv);
9159 parse_and_run_file(input);
9160 fclose_and_forget(input);
9163 restore_G_args(&sv, argv);
9164 #if ENABLE_HUSH_FUNCTIONS
9165 G.flag_return_in_progress = sv_flg;
9168 return G.last_exitcode;
9171 static int FAST_FUNC builtin_umask(char **argv)
9178 argv = skip_dash_dash(argv);
9180 mode_t old_mask = mask;
9182 /* numeric umasks are taken as-is */
9183 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9184 if (!isdigit(argv[0][0]))
9186 mask = bb_parse_mode(argv[0], mask);
9187 if (!isdigit(argv[0][0]))
9189 if ((unsigned)mask > 0777) {
9192 * bash: umask: 'q': invalid symbolic mode operator
9193 * bash: umask: 999: octal number out of range
9195 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9200 printf("%04o\n", (unsigned) mask);
9201 /* fall through and restore mask which we set to 0 */
9205 return !rc; /* rc != 0 - success */
9208 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9209 static int FAST_FUNC builtin_unset(char **argv)
9214 /* "!": do not abort on errors */
9215 /* "+": stop at 1st non-option */
9216 opts = getopt32(argv, "!+vf");
9217 if (opts == (unsigned)-1)
9218 return EXIT_FAILURE;
9220 bb_error_msg("unset: -v and -f are exclusive");
9221 return EXIT_FAILURE;
9227 if (!(opts & 2)) { /* not -f */
9228 if (unset_local_var(*argv)) {
9229 /* unset <nonexistent_var> doesn't fail.
9230 * Error is when one tries to unset RO var.
9231 * Message was printed by unset_local_var. */
9235 #if ENABLE_HUSH_FUNCTIONS
9245 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9246 static int FAST_FUNC builtin_wait(char **argv)
9248 int ret = EXIT_SUCCESS;
9251 argv = skip_dash_dash(argv);
9252 if (argv[0] == NULL) {
9253 /* Don't care about wait results */
9254 /* Note 1: must wait until there are no more children */
9255 /* Note 2: must be interruptible */
9257 * $ sleep 3 & sleep 6 & wait
9262 * $ sleep 3 & sleep 6 & wait
9266 * ^C <-- after ~4 sec from keyboard
9271 sigset_t oldset, allsigs;
9273 /* waitpid is not interruptible by SA_RESTARTed
9274 * signals which we use. Thus, this ugly dance:
9277 /* Make sure possible SIGCHLD is stored in kernel's
9278 * pending signal mask before we call waitpid.
9279 * Or else we may race with SIGCHLD, lose it,
9280 * and get stuck in sigwaitinfo...
9282 sigfillset(&allsigs);
9283 sigprocmask(SIG_SETMASK, &allsigs, &oldset);
9285 if (!sigisemptyset(&G.pending_set)) {
9286 /* Crap! we raced with some signal! */
9291 checkjobs(NULL); /* waitpid(WNOHANG) inside */
9292 if (errno == ECHILD) {
9293 sigprocmask(SIG_SETMASK, &oldset, NULL);
9297 /* Wait for SIGCHLD or any other signal */
9298 //sig = sigwaitinfo(&allsigs, NULL);
9299 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9300 /* Note: sigsuspend invokes signal handler */
9301 sigsuspend(&oldset);
9303 sigprocmask(SIG_SETMASK, &oldset, NULL);
9305 /* So, did we get a signal? */
9307 // raise(sig); /* run handler */
9308 sig = check_and_run_traps();
9309 if (sig /*&& sig != SIGCHLD - always true */) {
9314 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9319 /* This is probably buggy wrt interruptible-ness */
9321 pid_t pid = bb_strtou(*argv, NULL, 10);
9323 /* mimic bash message */
9324 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9325 return EXIT_FAILURE;
9327 if (waitpid(pid, &status, 0) == pid) {
9328 ret = WEXITSTATUS(status);
9329 if (WIFSIGNALED(status))
9330 ret = 128 + WTERMSIG(status);
9332 bb_perror_msg("wait %s", *argv);
9341 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9342 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9345 def = bb_strtou(argv[1], NULL, 10);
9346 if (errno || def < def_min || argv[2]) {
9347 bb_error_msg("%s: bad arguments", argv[0]);
9355 #if ENABLE_HUSH_LOOPS
9356 static int FAST_FUNC builtin_break(char **argv)
9359 if (G.depth_of_loop == 0) {
9360 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9361 /* if we came from builtin_continue(), need to undo "= 1" */
9362 G.flag_break_continue = 0;
9363 return EXIT_SUCCESS; /* bash compat */
9365 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9367 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9368 if (depth == UINT_MAX)
9369 G.flag_break_continue = BC_BREAK;
9370 if (G.depth_of_loop < depth)
9371 G.depth_break_continue = G.depth_of_loop;
9373 return EXIT_SUCCESS;
9376 static int FAST_FUNC builtin_continue(char **argv)
9378 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9379 return builtin_break(argv);
9383 #if ENABLE_HUSH_FUNCTIONS
9384 static int FAST_FUNC builtin_return(char **argv)
9388 if (G.flag_return_in_progress != -1) {
9389 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9390 return EXIT_FAILURE; /* bash compat */
9393 G.flag_return_in_progress = 1;
9396 * out of range: wraps around at 256, does not error out
9397 * non-numeric param:
9398 * f() { false; return qwe; }; f; echo $?
9399 * bash: return: qwe: numeric argument required <== we do this
9400 * 255 <== we also do this
9402 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);