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 #if ENABLE_HUSH_INTERACTIVE
466 smallint promptmode; /* 0: PS1, 1: PS2 */
471 int (*get) (struct in_str *) FAST_FUNC;
472 int (*peek) (struct in_str *) FAST_FUNC;
474 #define i_getch(input) ((input)->get(input))
475 #define i_peek(input) ((input)->peek(input))
477 /* The descrip member of this structure is only used to make
478 * debugging output pretty */
479 static const struct {
481 signed char default_fd;
484 { O_RDONLY, 0, "<" },
485 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
486 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
487 { O_CREAT|O_RDWR, 1, "<>" },
488 { O_RDONLY, 0, "<<" },
489 /* Should not be needed. Bogus default_fd helps in debugging */
490 /* { O_RDONLY, 77, "<<" }, */
493 struct redir_struct {
494 struct redir_struct *next;
495 char *rd_filename; /* filename */
496 int rd_fd; /* fd to redirect */
497 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
499 smallint rd_type; /* (enum redir_type) */
500 /* note: for heredocs, rd_filename contains heredoc delimiter,
501 * and subsequently heredoc itself; and rd_dup is a bitmask:
502 * bit 0: do we need to trim leading tabs?
503 * bit 1: is heredoc quoted (<<'delim' syntax) ?
506 typedef enum redir_type {
508 REDIRECT_OVERWRITE = 1,
511 REDIRECT_HEREDOC = 4,
512 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
515 REDIRFD_SYNTAX_ERR = -2,
516 REDIRFD_TO_FILE = -1,
517 /* otherwise, rd_fd is redirected to rd_dup */
519 HEREDOC_SKIPTABS = 1,
525 pid_t pid; /* 0 if exited */
526 int assignment_cnt; /* how many argv[i] are assignments? */
527 smallint cmd_type; /* CMD_xxx */
529 #define CMD_SUBSHELL 1
530 #if ENABLE_HUSH_BASH_COMPAT
531 /* used for "[[ EXPR ]]" */
532 # define CMD_SINGLEWORD_NOGLOB 2
534 #if ENABLE_HUSH_FUNCTIONS
535 # define CMD_FUNCDEF 3
538 smalluint cmd_exitcode;
539 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
542 char *group_as_string;
544 #if ENABLE_HUSH_FUNCTIONS
545 struct function *child_func;
546 /* This field is used to prevent a bug here:
547 * while...do f1() {a;}; f1; f1() {b;}; f1; done
548 * When we execute "f1() {a;}" cmd, we create new function and clear
549 * cmd->group, cmd->group_as_string, cmd->argv[0].
550 * When we execute "f1() {b;}", we notice that f1 exists,
551 * and that its "parent cmd" struct is still "alive",
552 * we put those fields back into cmd->xxx
553 * (struct function has ->parent_cmd ptr to facilitate that).
554 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
555 * Without this trick, loop would execute a;b;b;b;...
556 * instead of correct sequence a;b;a;b;...
557 * When command is freed, it severs the link
558 * (sets ->child_func->parent_cmd to NULL).
561 char **argv; /* command name and arguments */
562 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
563 * and on execution these are substituted with their values.
564 * Substitution can make _several_ words out of one argv[n]!
565 * Example: argv[0]=='.^C*^C.' here: echo .$*.
566 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
568 struct redir_struct *redirects; /* I/O redirections */
570 /* Is there anything in this command at all? */
571 #define IS_NULL_CMD(cmd) \
572 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
576 int num_cmds; /* total number of commands in pipe */
577 int alive_cmds; /* number of commands running (not exited) */
578 int stopped_cmds; /* number of commands alive, but stopped */
580 int jobid; /* job number */
581 pid_t pgrp; /* process group ID for the job */
582 char *cmdtext; /* name of job */
584 struct command *cmds; /* array of commands in pipe */
585 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
586 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
587 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
589 typedef enum pipe_style {
595 /* Is there anything in this pipe at all? */
596 #define IS_NULL_PIPE(pi) \
597 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
599 /* This holds pointers to the various results of parsing */
600 struct parse_context {
601 /* linked list of pipes */
602 struct pipe *list_head;
603 /* last pipe (being constructed right now) */
605 /* last command in pipe (being constructed right now) */
606 struct command *command;
607 /* last redirect in command->redirects list */
608 struct redir_struct *pending_redirect;
614 smallint ctx_inverted; /* "! cmd | cmd" */
616 smallint ctx_dsemicolon; /* ";;" seen */
618 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
620 /* group we are enclosed in:
621 * example: "if pipe1; pipe2; then pipe3; fi"
622 * when we see "if" or "then", we malloc and copy current context,
623 * and make ->stack point to it. then we parse pipeN.
624 * when closing "then" / fi" / whatever is found,
625 * we move list_head into ->stack->command->group,
626 * copy ->stack into current context, and delete ->stack.
627 * (parsing of { list } and ( list ) doesn't use this method)
629 struct parse_context *stack;
633 /* On program start, environ points to initial environment.
634 * putenv adds new pointers into it, unsetenv removes them.
635 * Neither of these (de)allocates the strings.
636 * setenv allocates new strings in malloc space and does putenv,
637 * and thus setenv is unusable (leaky) for shell's purposes */
638 #define setenv(...) setenv_is_leaky_dont_use()
640 struct variable *next;
641 char *varstr; /* points to "name=" portion */
642 #if ENABLE_HUSH_LOCAL
643 unsigned func_nest_level;
645 int max_len; /* if > 0, name is part of initial env; else name is malloced */
646 smallint flg_export; /* putenv should be done on this var */
647 smallint flg_read_only;
655 #if ENABLE_HUSH_FUNCTIONS
657 struct function *next;
659 struct command *parent_cmd;
662 char *body_as_string;
668 /* set -/+o OPT support. (TODO: make it optional)
669 * bash supports the following opts:
680 * interactive-comments on
698 static const char o_opt_strings[] ALIGN1 =
701 #if ENABLE_HUSH_MODE_X
708 #if ENABLE_HUSH_MODE_X
716 struct FILE_list *next;
722 /* "Globals" within this file */
723 /* Sorted roughly by size (smaller offsets == smaller code) */
725 /* interactive_fd != 0 means we are an interactive shell.
726 * If we are, then saved_tty_pgrp can also be != 0, meaning
727 * that controlling tty is available. With saved_tty_pgrp == 0,
728 * job control still works, but terminal signals
729 * (^C, ^Z, ^Y, ^\) won't work at all, and background
730 * process groups can only be created with "cmd &".
731 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
732 * to give tty to the foreground process group,
733 * and will take it back when the group is stopped (^Z)
736 #if ENABLE_HUSH_INTERACTIVE
737 /* 'interactive_fd' is a fd# open to ctty, if we have one
738 * _AND_ if we decided to act interactively */
742 # define G_interactive_fd (G.interactive_fd)
744 # define G_interactive_fd 0
746 #if ENABLE_FEATURE_EDITING
747 line_input_t *line_input_state;
752 #if ENABLE_HUSH_RANDOM_SUPPORT
758 pid_t saved_tty_pgrp;
759 struct pipe *job_list;
760 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
762 # define G_saved_tty_pgrp 0
764 char o_opt[NUM_OPT_O];
765 #if ENABLE_HUSH_MODE_X
766 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
770 smallint flag_SIGINT;
771 #if ENABLE_HUSH_LOOPS
772 smallint flag_break_continue;
774 #if ENABLE_HUSH_FUNCTIONS
775 /* 0: outside of a function (or sourced file)
776 * -1: inside of a function, ok to use return builtin
777 * 1: return is invoked, skip all till end of func
779 smallint flag_return_in_progress;
781 smallint exiting; /* used to prevent EXIT trap recursion */
782 /* These four support $?, $#, and $1 */
783 smalluint last_exitcode;
784 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
785 smalluint global_args_malloced;
786 /* how many non-NULL argv's we have. NB: $# + 1 */
790 char *argv0_for_re_execing;
792 #if ENABLE_HUSH_LOOPS
793 unsigned depth_break_continue;
794 unsigned depth_of_loop;
798 struct variable *top_var;
799 char **expanded_assignments;
800 #if ENABLE_HUSH_FUNCTIONS
801 struct function *top_func;
802 # if ENABLE_HUSH_LOCAL
803 struct variable **shadowed_vars_pp;
804 unsigned func_nest_level;
807 /* Signal and trap handling */
809 unsigned count_SIGCHLD;
810 unsigned handled_SIGCHLD;
811 smallint we_have_children;
813 struct FILE_list *FILE_list;
814 /* Which signals have non-DFL handler (even with no traps set)?
815 * Set at the start to:
816 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
817 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
818 * The rest is cleared right before execv syscalls.
819 * Other than these two times, never modified.
821 unsigned special_sig_mask;
823 unsigned fatal_sig_mask;
824 # define G_fatal_sig_mask G.fatal_sig_mask
826 # define G_fatal_sig_mask 0
828 char **traps; /* char *traps[NSIG] */
829 sigset_t pending_set;
831 unsigned long memleak_value;
835 #if ENABLE_FEATURE_EDITING
836 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
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");
2126 * in_str support (strings, and "strings" read from files).
2129 #if ENABLE_HUSH_INTERACTIVE
2130 /* To test correct lineedit/interactive behavior, type from command line:
2136 * It excercises a lot of corner cases.
2138 static void cmdedit_update_prompt(void)
2140 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2141 G.PS1 = get_local_var_value("PS1");
2144 G.PS2 = get_local_var_value("PS2");
2151 static const char *setup_prompt_string(int promptmode)
2153 const char *prompt_str;
2154 debug_printf("setup_prompt_string %d ", promptmode);
2155 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2156 /* Set up the prompt */
2157 if (promptmode == 0) { /* PS1 */
2159 /* bash uses $PWD value, even if it is set by user.
2160 * It uses current dir only if PWD is unset.
2161 * We always use current dir. */
2162 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2167 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2168 debug_printf("prompt_str '%s'\n", prompt_str);
2171 static int get_user_input(struct in_str *i)
2174 const char *prompt_str;
2176 prompt_str = setup_prompt_string(i->promptmode);
2177 # if ENABLE_FEATURE_EDITING
2179 reinit_unicode_for_hush();
2181 /* buglet: SIGINT will not make new prompt to appear _at once_,
2182 * only after <Enter>. (^C will work) */
2183 r = read_line_input(G.line_input_state, prompt_str,
2184 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2187 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2188 check_and_run_traps();
2189 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2191 /* EOF/error detected */
2193 i->peek_buf[0] = r = EOF;
2196 i->p = G.user_input_buf;
2197 return (unsigned char)*i->p++;
2201 if (i->last_char == '\0' || i->last_char == '\n') {
2202 /* Why check_and_run_traps here? Try this interactively:
2203 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2204 * $ <[enter], repeatedly...>
2205 * Without check_and_run_traps, handler never runs.
2207 check_and_run_traps();
2208 fputs(prompt_str, stdout);
2212 } while (G.flag_SIGINT || r == '\0');
2216 /* This is the magic location that prints prompts
2217 * and gets data back from the user */
2218 static int fgetc_interactive(struct in_str *i)
2221 /* If it's interactive stdin, get new line. */
2222 if (G_interactive_fd && i->file == stdin) {
2223 /* Returns first char (or EOF), the rest is in i->p[] */
2224 ch = get_user_input(i);
2225 i->promptmode = 1; /* PS2 */
2227 /* Not stdin: script file, sourced file, etc */
2228 do ch = fgetc(i->file); while (ch == '\0');
2233 static inline int fgetc_interactive(struct in_str *i)
2236 do ch = fgetc(i->file); while (ch == '\0');
2239 #endif /* INTERACTIVE */
2241 static int FAST_FUNC file_get(struct in_str *i)
2245 #if ENABLE_FEATURE_EDITING
2246 /* This can be stdin, check line editing char[] buffer */
2247 if (i->p && *i->p != '\0') {
2248 ch = (unsigned char)*i->p++;
2252 /* peek_buf[] is an int array, not char. Can contain EOF. */
2253 ch = i->peek_buf[0];
2255 int ch2 = i->peek_buf[1];
2256 i->peek_buf[0] = ch2;
2257 if (ch2 == 0) /* very likely, avoid redundant write */
2263 ch = fgetc_interactive(i);
2265 debug_printf("file_get: got '%c' %d\n", ch, ch);
2270 static int FAST_FUNC file_peek(struct in_str *i)
2274 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2275 /* This can be stdin, check line editing char[] buffer */
2276 if (i->p && *i->p != '\0')
2277 return (unsigned char)*i->p;
2279 /* peek_buf[] is an int array, not char. Can contain EOF. */
2280 ch = i->peek_buf[0];
2284 /* Need to get a new char */
2285 ch = fgetc_interactive(i);
2286 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2288 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2289 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2295 i->peek_buf[0] = ch;
2296 /*i->peek_buf[1] = 0; - already is */
2300 static int FAST_FUNC static_get(struct in_str *i)
2302 int ch = (unsigned char)*i->p;
2311 static int FAST_FUNC static_peek(struct in_str *i)
2313 /* Doesn't report EOF on NUL. None of the callers care. */
2314 return (unsigned char)*i->p;
2317 /* Only ever called if i_peek() was called, and did not return EOF.
2318 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2319 * not end-of-line. Therefore we never need to read a new editing line here.
2321 static int i_peek2(struct in_str *i)
2325 /* There are two cases when i->p[] buffer exists.
2326 * (1) it's a string in_str.
2327 * (2) It's a file, and we have a saved line editing buffer.
2328 * In both cases, we know that i->p[0] exists and not NUL, and
2329 * the peek2 result is in i->p[1].
2332 return (unsigned char)i->p[1];
2334 /* Now we know it is a file-based in_str. */
2336 /* peek_buf[] is an int array, not char. Can contain EOF. */
2337 /* Is there 2nd char? */
2338 ch = i->peek_buf[1];
2340 /* We did not read it yet, get it now */
2341 do ch = fgetc(i->file); while (ch == '\0');
2342 i->peek_buf[1] = ch;
2345 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2349 static void setup_file_in_str(struct in_str *i, FILE *f)
2351 memset(i, 0, sizeof(*i));
2353 i->peek = file_peek;
2354 /* i->promptmode = 0; - PS1 (memset did it) */
2359 static void setup_string_in_str(struct in_str *i, const char *s)
2361 memset(i, 0, sizeof(*i));
2362 i->get = static_get;
2363 i->peek = static_peek;
2364 /* i->promptmode = 0; - PS1 (memset did it) */
2372 #define B_CHUNK (32 * sizeof(char*))
2374 static void o_reset_to_empty_unquoted(o_string *o)
2377 o->has_quoted_part = 0;
2382 static void o_free(o_string *o)
2385 memset(o, 0, sizeof(*o));
2388 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2393 static void o_grow_by(o_string *o, int len)
2395 if (o->length + len > o->maxlen) {
2396 o->maxlen += (2 * len) | (B_CHUNK-1);
2397 o->data = xrealloc(o->data, 1 + o->maxlen);
2401 static void o_addchr(o_string *o, int ch)
2403 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2404 if (o->length < o->maxlen) {
2405 /* likely. avoid o_grow_by() call */
2407 o->data[o->length] = ch;
2409 o->data[o->length] = '\0';
2417 /* Valid only if we know o_string is not empty */
2418 static void o_delchr(o_string *o)
2421 o->data[o->length] = '\0';
2425 static void o_addblock(o_string *o, const char *str, int len)
2428 memcpy(&o->data[o->length], str, len);
2430 o->data[o->length] = '\0';
2433 static void o_addstr(o_string *o, const char *str)
2435 o_addblock(o, str, strlen(str));
2439 static void nommu_addchr(o_string *o, int ch)
2445 # define nommu_addchr(o, str) ((void)0)
2448 static void o_addstr_with_NUL(o_string *o, const char *str)
2450 o_addblock(o, str, strlen(str) + 1);
2454 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2455 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2456 * Apparently, on unquoted $v bash still does globbing
2457 * ("v='*.txt'; echo $v" prints all .txt files),
2458 * but NOT brace expansion! Thus, there should be TWO independent
2459 * quoting mechanisms on $v expansion side: one protects
2460 * $v from brace expansion, and other additionally protects "$v" against globbing.
2461 * We have only second one.
2464 #if ENABLE_HUSH_BRACE_EXPANSION
2465 # define MAYBE_BRACES "{}"
2467 # define MAYBE_BRACES ""
2470 /* My analysis of quoting semantics tells me that state information
2471 * is associated with a destination, not a source.
2473 static void o_addqchr(o_string *o, int ch)
2476 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2481 o->data[o->length] = '\\';
2484 o->data[o->length] = ch;
2486 o->data[o->length] = '\0';
2489 static void o_addQchr(o_string *o, int ch)
2492 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2493 && strchr("*?[\\" MAYBE_BRACES, ch)
2496 o->data[o->length] = '\\';
2500 o->data[o->length] = ch;
2502 o->data[o->length] = '\0';
2505 static void o_addqblock(o_string *o, const char *str, int len)
2510 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2511 if (ordinary_cnt > len) /* paranoia */
2513 o_addblock(o, str, ordinary_cnt);
2514 if (ordinary_cnt == len)
2515 return; /* NUL is already added by o_addblock */
2516 str += ordinary_cnt;
2517 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2521 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2523 o->data[o->length] = '\\';
2527 o->data[o->length] = ch;
2530 o->data[o->length] = '\0';
2533 static void o_addQblock(o_string *o, const char *str, int len)
2535 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2536 o_addblock(o, str, len);
2539 o_addqblock(o, str, len);
2542 static void o_addQstr(o_string *o, const char *str)
2544 o_addQblock(o, str, strlen(str));
2547 /* A special kind of o_string for $VAR and `cmd` expansion.
2548 * It contains char* list[] at the beginning, which is grown in 16 element
2549 * increments. Actual string data starts at the next multiple of 16 * (char*).
2550 * list[i] contains an INDEX (int!) into this string data.
2551 * It means that if list[] needs to grow, data needs to be moved higher up
2552 * but list[i]'s need not be modified.
2553 * NB: remembering how many list[i]'s you have there is crucial.
2554 * o_finalize_list() operation post-processes this structure - calculates
2555 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2557 #if DEBUG_EXPAND || DEBUG_GLOB
2558 static void debug_print_list(const char *prefix, o_string *o, int n)
2560 char **list = (char**)o->data;
2561 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2565 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2566 prefix, list, n, string_start, o->length, o->maxlen,
2567 !!(o->o_expflags & EXP_FLAG_GLOB),
2569 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2572 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2573 o->data + (int)(uintptr_t)list[i] + string_start,
2574 o->data + (int)(uintptr_t)list[i] + string_start);
2578 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2580 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2584 # define debug_print_list(prefix, o, n) ((void)0)
2587 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2588 * in list[n] so that it points past last stored byte so far.
2589 * It returns n+1. */
2590 static int o_save_ptr_helper(o_string *o, int n)
2592 char **list = (char**)o->data;
2596 if (!o->has_empty_slot) {
2597 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2598 string_len = o->length - string_start;
2599 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2600 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2601 /* list[n] points to string_start, make space for 16 more pointers */
2602 o->maxlen += 0x10 * sizeof(list[0]);
2603 o->data = xrealloc(o->data, o->maxlen + 1);
2604 list = (char**)o->data;
2605 memmove(list + n + 0x10, list + n, string_len);
2606 o->length += 0x10 * sizeof(list[0]);
2608 debug_printf_list("list[%d]=%d string_start=%d\n",
2609 n, string_len, string_start);
2612 /* We have empty slot at list[n], reuse without growth */
2613 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2614 string_len = o->length - string_start;
2615 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2616 n, string_len, string_start);
2617 o->has_empty_slot = 0;
2619 o->has_quoted_part = 0;
2620 list[n] = (char*)(uintptr_t)string_len;
2624 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2625 static int o_get_last_ptr(o_string *o, int n)
2627 char **list = (char**)o->data;
2628 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2630 return ((int)(uintptr_t)list[n-1]) + string_start;
2633 #if ENABLE_HUSH_BRACE_EXPANSION
2634 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2635 * first, it processes even {a} (no commas), second,
2636 * I didn't manage to make it return strings when they don't match
2637 * existing files. Need to re-implement it.
2641 static int glob_needed(const char *s)
2650 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2656 /* Return pointer to next closing brace or to comma */
2657 static const char *next_brace_sub(const char *cp)
2661 while (*cp != '\0') {
2668 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2674 return *cp != '\0' ? cp : NULL;
2676 /* Recursive brace globber. Note: may garble pattern[]. */
2677 static int glob_brace(char *pattern, o_string *o, int n)
2679 char *new_pattern_buf;
2686 debug_printf_glob("glob_brace('%s')\n", pattern);
2692 if (*begin == '{') {
2693 /* Find the first sub-pattern and at the same time
2694 * find the rest after the closing brace */
2695 next = next_brace_sub(begin);
2697 /* An illegal expression */
2701 /* "{abc}" with no commas - illegal
2702 * brace expr, disregard and skip it */
2708 if (*begin == '\\' && begin[1] != '\0')
2712 debug_printf_glob("begin:%s\n", begin);
2713 debug_printf_glob("next:%s\n", next);
2715 /* Now find the end of the whole brace expression */
2717 while (*rest != '}') {
2718 rest = next_brace_sub(rest);
2720 /* An illegal expression */
2723 debug_printf_glob("rest:%s\n", rest);
2725 rest_len = strlen(++rest) + 1;
2727 /* We are sure the brace expression is well-formed */
2729 /* Allocate working buffer large enough for our work */
2730 new_pattern_buf = xmalloc(strlen(pattern));
2732 /* We have a brace expression. BEGIN points to the opening {,
2733 * NEXT points past the terminator of the first element, and REST
2734 * points past the final }. We will accumulate result names from
2735 * recursive runs for each brace alternative in the buffer using
2740 /* Construct the new glob expression */
2743 mempcpy(new_pattern_buf,
2744 /* We know the prefix for all sub-patterns */
2745 pattern, begin - pattern),
2749 /* Note: glob_brace() may garble new_pattern_buf[].
2750 * That's why we re-copy prefix every time (1st memcpy above).
2752 n = glob_brace(new_pattern_buf, o, n);
2754 /* We saw the last entry */
2758 next = next_brace_sub(next);
2760 free(new_pattern_buf);
2768 memset(&globdata, 0, sizeof(globdata));
2769 gr = glob(pattern, 0, NULL, &globdata);
2770 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2772 if (gr == GLOB_NOMATCH) {
2773 globfree(&globdata);
2774 /* NB: garbles parameter */
2775 unbackslash(pattern);
2776 o_addstr_with_NUL(o, pattern);
2777 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2778 return o_save_ptr_helper(o, n);
2780 if (gr == GLOB_NOSPACE)
2781 bb_error_msg_and_die(bb_msg_memory_exhausted);
2782 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2783 * but we didn't specify it. Paranoia again. */
2784 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2786 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2787 char **argv = globdata.gl_pathv;
2789 o_addstr_with_NUL(o, *argv);
2790 n = o_save_ptr_helper(o, n);
2796 globfree(&globdata);
2800 /* Performs globbing on last list[],
2801 * saving each result as a new list[].
2803 static int perform_glob(o_string *o, int n)
2805 char *pattern, *copy;
2807 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2809 return o_save_ptr_helper(o, n);
2810 pattern = o->data + o_get_last_ptr(o, n);
2811 debug_printf_glob("glob pattern '%s'\n", pattern);
2812 if (!glob_needed(pattern)) {
2813 /* unbackslash last string in o in place, fix length */
2814 o->length = unbackslash(pattern) - o->data;
2815 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2816 return o_save_ptr_helper(o, n);
2819 copy = xstrdup(pattern);
2820 /* "forget" pattern in o */
2821 o->length = pattern - o->data;
2822 n = glob_brace(copy, o, n);
2825 debug_print_list("perform_glob returning", o, n);
2829 #else /* !HUSH_BRACE_EXPANSION */
2832 static int glob_needed(const char *s)
2841 if (*s == '*' || *s == '[' || *s == '?')
2847 /* Performs globbing on last list[],
2848 * saving each result as a new list[].
2850 static int perform_glob(o_string *o, int n)
2856 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2858 return o_save_ptr_helper(o, n);
2859 pattern = o->data + o_get_last_ptr(o, n);
2860 debug_printf_glob("glob pattern '%s'\n", pattern);
2861 if (!glob_needed(pattern)) {
2863 /* unbackslash last string in o in place, fix length */
2864 o->length = unbackslash(pattern) - o->data;
2865 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2866 return o_save_ptr_helper(o, n);
2869 memset(&globdata, 0, sizeof(globdata));
2870 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2871 * If we glob "*.\*" and don't find anything, we need
2872 * to fall back to using literal "*.*", but GLOB_NOCHECK
2873 * will return "*.\*"!
2875 gr = glob(pattern, 0, NULL, &globdata);
2876 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2878 if (gr == GLOB_NOMATCH) {
2879 globfree(&globdata);
2882 if (gr == GLOB_NOSPACE)
2883 bb_error_msg_and_die(bb_msg_memory_exhausted);
2884 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2885 * but we didn't specify it. Paranoia again. */
2886 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2888 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2889 char **argv = globdata.gl_pathv;
2890 /* "forget" pattern in o */
2891 o->length = pattern - o->data;
2893 o_addstr_with_NUL(o, *argv);
2894 n = o_save_ptr_helper(o, n);
2900 globfree(&globdata);
2902 debug_print_list("perform_glob returning", o, n);
2906 #endif /* !HUSH_BRACE_EXPANSION */
2908 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2909 * Otherwise, just finish current list[] and start new */
2910 static int o_save_ptr(o_string *o, int n)
2912 if (o->o_expflags & EXP_FLAG_GLOB) {
2913 /* If o->has_empty_slot, list[n] was already globbed
2914 * (if it was requested back then when it was filled)
2915 * so don't do that again! */
2916 if (!o->has_empty_slot)
2917 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2919 return o_save_ptr_helper(o, n);
2922 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2923 static char **o_finalize_list(o_string *o, int n)
2928 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2930 debug_print_list("finalized", o, n);
2931 debug_printf_expand("finalized n:%d\n", n);
2932 list = (char**)o->data;
2933 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2937 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2942 static void free_pipe_list(struct pipe *pi);
2944 /* Returns pi->next - next pipe in the list */
2945 static struct pipe *free_pipe(struct pipe *pi)
2950 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2951 for (i = 0; i < pi->num_cmds; i++) {
2952 struct command *command;
2953 struct redir_struct *r, *rnext;
2955 command = &pi->cmds[i];
2956 debug_printf_clean(" command %d:\n", i);
2957 if (command->argv) {
2961 for (a = 0, p = command->argv; *p; a++, p++) {
2962 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2965 free_strings(command->argv);
2966 //command->argv = NULL;
2968 /* not "else if": on syntax error, we may have both! */
2969 if (command->group) {
2970 debug_printf_clean(" begin group (cmd_type:%d)\n",
2972 free_pipe_list(command->group);
2973 debug_printf_clean(" end group\n");
2974 //command->group = NULL;
2976 /* else is crucial here.
2977 * If group != NULL, child_func is meaningless */
2978 #if ENABLE_HUSH_FUNCTIONS
2979 else if (command->child_func) {
2980 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2981 command->child_func->parent_cmd = NULL;
2985 free(command->group_as_string);
2986 //command->group_as_string = NULL;
2988 for (r = command->redirects; r; r = rnext) {
2989 debug_printf_clean(" redirect %d%s",
2990 r->rd_fd, redir_table[r->rd_type].descrip);
2991 /* guard against the case >$FOO, where foo is unset or blank */
2992 if (r->rd_filename) {
2993 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2994 free(r->rd_filename);
2995 //r->rd_filename = NULL;
2997 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3001 //command->redirects = NULL;
3003 free(pi->cmds); /* children are an array, they get freed all at once */
3007 //pi->cmdtext = NULL;
3015 static void free_pipe_list(struct pipe *pi)
3019 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3021 debug_printf_clean("pipe followup code %d\n", pi->followup);
3027 /*** Parsing routines ***/
3029 #ifndef debug_print_tree
3030 static void debug_print_tree(struct pipe *pi, int lvl)
3032 static const char *const PIPE[] = {
3038 static const char *RES[] = {
3039 [RES_NONE ] = "NONE" ,
3042 [RES_THEN ] = "THEN" ,
3043 [RES_ELIF ] = "ELIF" ,
3044 [RES_ELSE ] = "ELSE" ,
3047 # if ENABLE_HUSH_LOOPS
3048 [RES_FOR ] = "FOR" ,
3049 [RES_WHILE] = "WHILE",
3050 [RES_UNTIL] = "UNTIL",
3052 [RES_DONE ] = "DONE" ,
3054 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3057 # if ENABLE_HUSH_CASE
3058 [RES_CASE ] = "CASE" ,
3059 [RES_CASE_IN ] = "CASE_IN" ,
3060 [RES_MATCH] = "MATCH",
3061 [RES_CASE_BODY] = "CASE_BODY",
3062 [RES_ESAC ] = "ESAC" ,
3064 [RES_XXXX ] = "XXXX" ,
3065 [RES_SNTX ] = "SNTX" ,
3067 static const char *const CMDTYPE[] = {
3071 # if ENABLE_HUSH_FUNCTIONS
3080 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3081 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3083 while (prn < pi->num_cmds) {
3084 struct command *command = &pi->cmds[prn];
3085 char **argv = command->argv;
3087 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3089 command->assignment_cnt);
3090 if (command->group) {
3091 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3092 CMDTYPE[command->cmd_type],
3095 , " group_as_string:", command->group_as_string
3100 debug_print_tree(command->group, lvl+1);
3104 if (argv) while (*argv) {
3105 fdprintf(2, " '%s'", *argv);
3115 #endif /* debug_print_tree */
3117 static struct pipe *new_pipe(void)
3120 pi = xzalloc(sizeof(struct pipe));
3121 /*pi->followup = 0; - deliberately invalid value */
3122 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3126 /* Command (member of a pipe) is complete, or we start a new pipe
3127 * if ctx->command is NULL.
3128 * No errors possible here.
3130 static int done_command(struct parse_context *ctx)
3132 /* The command is really already in the pipe structure, so
3133 * advance the pipe counter and make a new, null command. */
3134 struct pipe *pi = ctx->pipe;
3135 struct command *command = ctx->command;
3137 #if 0 /* Instead we emit error message at run time */
3138 if (ctx->pending_redirect) {
3139 /* For example, "cmd >" (no filename to redirect to) */
3140 die_if_script("syntax error: %s", "invalid redirect");
3141 ctx->pending_redirect = NULL;
3146 if (IS_NULL_CMD(command)) {
3147 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3151 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3152 //debug_print_tree(ctx->list_head, 20);
3154 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3157 /* Only real trickiness here is that the uncommitted
3158 * command structure is not counted in pi->num_cmds. */
3159 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3160 ctx->command = command = &pi->cmds[pi->num_cmds];
3162 memset(command, 0, sizeof(*command));
3163 return pi->num_cmds; /* used only for 0/nonzero check */
3166 static void done_pipe(struct parse_context *ctx, pipe_style type)
3170 debug_printf_parse("done_pipe entered, followup %d\n", type);
3171 /* Close previous command */
3172 not_null = done_command(ctx);
3173 ctx->pipe->followup = type;
3175 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3176 ctx->ctx_inverted = 0;
3177 ctx->pipe->res_word = ctx->ctx_res_w;
3180 /* Without this check, even just <enter> on command line generates
3181 * tree of three NOPs (!). Which is harmless but annoying.
3182 * IOW: it is safe to do it unconditionally. */
3185 || ctx->ctx_res_w == RES_FI
3187 #if ENABLE_HUSH_LOOPS
3188 || ctx->ctx_res_w == RES_DONE
3189 || ctx->ctx_res_w == RES_FOR
3190 || ctx->ctx_res_w == RES_IN
3192 #if ENABLE_HUSH_CASE
3193 || ctx->ctx_res_w == RES_ESAC
3197 debug_printf_parse("done_pipe: adding new pipe: "
3198 "not_null:%d ctx->ctx_res_w:%d\n",
3199 not_null, ctx->ctx_res_w);
3201 ctx->pipe->next = new_p;
3203 /* RES_THEN, RES_DO etc are "sticky" -
3204 * they remain set for pipes inside if/while.
3205 * This is used to control execution.
3206 * RES_FOR and RES_IN are NOT sticky (needed to support
3207 * cases where variable or value happens to match a keyword):
3209 #if ENABLE_HUSH_LOOPS
3210 if (ctx->ctx_res_w == RES_FOR
3211 || ctx->ctx_res_w == RES_IN)
3212 ctx->ctx_res_w = RES_NONE;
3214 #if ENABLE_HUSH_CASE
3215 if (ctx->ctx_res_w == RES_MATCH)
3216 ctx->ctx_res_w = RES_CASE_BODY;
3217 if (ctx->ctx_res_w == RES_CASE)
3218 ctx->ctx_res_w = RES_CASE_IN;
3220 ctx->command = NULL; /* trick done_command below */
3221 /* Create the memory for command, roughly:
3222 * ctx->pipe->cmds = new struct command;
3223 * ctx->command = &ctx->pipe->cmds[0];
3226 //debug_print_tree(ctx->list_head, 10);
3228 debug_printf_parse("done_pipe return\n");
3231 static void initialize_context(struct parse_context *ctx)
3233 memset(ctx, 0, sizeof(*ctx));
3234 ctx->pipe = ctx->list_head = new_pipe();
3235 /* Create the memory for command, roughly:
3236 * ctx->pipe->cmds = new struct command;
3237 * ctx->command = &ctx->pipe->cmds[0];
3242 /* If a reserved word is found and processed, parse context is modified
3243 * and 1 is returned.
3246 struct reserved_combo {
3249 unsigned char assignment_flag;
3253 FLAG_END = (1 << RES_NONE ),
3255 FLAG_IF = (1 << RES_IF ),
3256 FLAG_THEN = (1 << RES_THEN ),
3257 FLAG_ELIF = (1 << RES_ELIF ),
3258 FLAG_ELSE = (1 << RES_ELSE ),
3259 FLAG_FI = (1 << RES_FI ),
3261 # if ENABLE_HUSH_LOOPS
3262 FLAG_FOR = (1 << RES_FOR ),
3263 FLAG_WHILE = (1 << RES_WHILE),
3264 FLAG_UNTIL = (1 << RES_UNTIL),
3265 FLAG_DO = (1 << RES_DO ),
3266 FLAG_DONE = (1 << RES_DONE ),
3267 FLAG_IN = (1 << RES_IN ),
3269 # if ENABLE_HUSH_CASE
3270 FLAG_MATCH = (1 << RES_MATCH),
3271 FLAG_ESAC = (1 << RES_ESAC ),
3273 FLAG_START = (1 << RES_XXXX ),
3276 static const struct reserved_combo* match_reserved_word(o_string *word)
3278 /* Mostly a list of accepted follow-up reserved words.
3279 * FLAG_END means we are done with the sequence, and are ready
3280 * to turn the compound list into a command.
3281 * FLAG_START means the word must start a new compound list.
3283 static const struct reserved_combo reserved_list[] = {
3285 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3286 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3287 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3288 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3289 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3290 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3292 # if ENABLE_HUSH_LOOPS
3293 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3294 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3295 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3296 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3297 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3298 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3300 # if ENABLE_HUSH_CASE
3301 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3302 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3305 const struct reserved_combo *r;
3307 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3308 if (strcmp(word->data, r->literal) == 0)
3313 /* Return 0: not a keyword, 1: keyword
3315 static int reserved_word(o_string *word, struct parse_context *ctx)
3317 # if ENABLE_HUSH_CASE
3318 static const struct reserved_combo reserved_match = {
3319 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3322 const struct reserved_combo *r;
3324 if (word->has_quoted_part)
3326 r = match_reserved_word(word);
3330 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3331 # if ENABLE_HUSH_CASE
3332 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3333 /* "case word IN ..." - IN part starts first MATCH part */
3334 r = &reserved_match;
3337 if (r->flag == 0) { /* '!' */
3338 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3339 syntax_error("! ! command");
3340 ctx->ctx_res_w = RES_SNTX;
3342 ctx->ctx_inverted = 1;
3345 if (r->flag & FLAG_START) {
3346 struct parse_context *old;
3348 old = xmalloc(sizeof(*old));
3349 debug_printf_parse("push stack %p\n", old);
3350 *old = *ctx; /* physical copy */
3351 initialize_context(ctx);
3353 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3354 syntax_error_at(word->data);
3355 ctx->ctx_res_w = RES_SNTX;
3358 /* "{...} fi" is ok. "{...} if" is not
3360 * if { echo foo; } then { echo bar; } fi */
3361 if (ctx->command->group)
3362 done_pipe(ctx, PIPE_SEQ);
3365 ctx->ctx_res_w = r->res;
3366 ctx->old_flag = r->flag;
3367 word->o_assignment = r->assignment_flag;
3368 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3370 if (ctx->old_flag & FLAG_END) {
3371 struct parse_context *old;
3373 done_pipe(ctx, PIPE_SEQ);
3374 debug_printf_parse("pop stack %p\n", ctx->stack);
3376 old->command->group = ctx->list_head;
3377 old->command->cmd_type = CMD_NORMAL;
3379 /* At this point, the compound command's string is in
3380 * ctx->as_string... except for the leading keyword!
3381 * Consider this example: "echo a | if true; then echo a; fi"
3382 * ctx->as_string will contain "true; then echo a; fi",
3383 * with "if " remaining in old->as_string!
3387 int len = old->as_string.length;
3388 /* Concatenate halves */
3389 o_addstr(&old->as_string, ctx->as_string.data);
3390 o_free_unsafe(&ctx->as_string);
3391 /* Find where leading keyword starts in first half */
3392 str = old->as_string.data + len;
3393 if (str > old->as_string.data)
3394 str--; /* skip whitespace after keyword */
3395 while (str > old->as_string.data && isalpha(str[-1]))
3397 /* Ugh, we're done with this horrid hack */
3398 old->command->group_as_string = xstrdup(str);
3399 debug_printf_parse("pop, remembering as:'%s'\n",
3400 old->command->group_as_string);
3403 *ctx = *old; /* physical copy */
3408 #endif /* HAS_KEYWORDS */
3410 /* Word is complete, look at it and update parsing context.
3411 * Normal return is 0. Syntax errors return 1.
3412 * Note: on return, word is reset, but not o_free'd!
3414 static int done_word(o_string *word, struct parse_context *ctx)
3416 struct command *command = ctx->command;
3418 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3419 if (word->length == 0 && !word->has_quoted_part) {
3420 debug_printf_parse("done_word return 0: true null, ignored\n");
3424 if (ctx->pending_redirect) {
3425 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3426 * only if run as "bash", not "sh" */
3427 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3429 * ...the word that follows the redirection operator
3430 * shall be subjected to tilde expansion, parameter expansion,
3431 * command substitution, arithmetic expansion, and quote
3432 * removal. Pathname expansion shall not be performed
3433 * on the word by a non-interactive shell; an interactive
3434 * shell may perform it, but shall do so only when
3435 * the expansion would result in one word."
3437 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3438 /* Cater for >\file case:
3439 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3440 * Same with heredocs:
3441 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3443 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3444 unbackslash(ctx->pending_redirect->rd_filename);
3445 /* Is it <<"HEREDOC"? */
3446 if (word->has_quoted_part) {
3447 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3450 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3451 ctx->pending_redirect = NULL;
3454 # if ENABLE_HUSH_CASE
3455 if (ctx->ctx_dsemicolon
3456 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3458 /* already done when ctx_dsemicolon was set to 1: */
3459 /* ctx->ctx_res_w = RES_MATCH; */
3460 ctx->ctx_dsemicolon = 0;
3463 if (!command->argv /* if it's the first word... */
3464 # if ENABLE_HUSH_LOOPS
3465 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3466 && ctx->ctx_res_w != RES_IN
3468 # if ENABLE_HUSH_CASE
3469 && ctx->ctx_res_w != RES_CASE
3472 int reserved = reserved_word(word, ctx);
3473 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3475 o_reset_to_empty_unquoted(word);
3476 debug_printf_parse("done_word return %d\n",
3477 (ctx->ctx_res_w == RES_SNTX));
3478 return (ctx->ctx_res_w == RES_SNTX);
3480 # if ENABLE_HUSH_BASH_COMPAT
3481 if (strcmp(word->data, "[[") == 0) {
3482 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3488 if (command->group) {
3489 /* "{ echo foo; } echo bar" - bad */
3490 syntax_error_at(word->data);
3491 debug_printf_parse("done_word return 1: syntax error, "
3492 "groups and arglists don't mix\n");
3496 /* If this word wasn't an assignment, next ones definitely
3497 * can't be assignments. Even if they look like ones. */
3498 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3499 && word->o_assignment != WORD_IS_KEYWORD
3501 word->o_assignment = NOT_ASSIGNMENT;
3503 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3504 command->assignment_cnt++;
3505 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3507 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3508 word->o_assignment = MAYBE_ASSIGNMENT;
3510 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3512 if (word->has_quoted_part
3513 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3514 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3515 /* (otherwise it's known to be not empty and is already safe) */
3517 /* exclude "$@" - it can expand to no word despite "" */
3518 char *p = word->data;
3519 while (p[0] == SPECIAL_VAR_SYMBOL
3520 && (p[1] & 0x7f) == '@'
3521 && p[2] == SPECIAL_VAR_SYMBOL
3526 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3527 debug_print_strings("word appended to argv", command->argv);
3530 #if ENABLE_HUSH_LOOPS
3531 if (ctx->ctx_res_w == RES_FOR) {
3532 if (word->has_quoted_part
3533 || !is_well_formed_var_name(command->argv[0], '\0')
3535 /* bash says just "not a valid identifier" */
3536 syntax_error("not a valid identifier in for");
3539 /* Force FOR to have just one word (variable name) */
3540 /* NB: basically, this makes hush see "for v in ..."
3541 * syntax as if it is "for v; in ...". FOR and IN become
3542 * two pipe structs in parse tree. */
3543 done_pipe(ctx, PIPE_SEQ);
3546 #if ENABLE_HUSH_CASE
3547 /* Force CASE to have just one word */
3548 if (ctx->ctx_res_w == RES_CASE) {
3549 done_pipe(ctx, PIPE_SEQ);
3553 o_reset_to_empty_unquoted(word);
3555 debug_printf_parse("done_word return 0\n");
3560 /* Peek ahead in the input to find out if we have a "&n" construct,
3561 * as in "2>&1", that represents duplicating a file descriptor.
3563 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3564 * REDIRFD_SYNTAX_ERR if syntax error,
3565 * REDIRFD_TO_FILE if no & was seen,
3566 * or the number found.
3569 #define parse_redir_right_fd(as_string, input) \
3570 parse_redir_right_fd(input)
3572 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3578 return REDIRFD_TO_FILE;
3580 ch = i_getch(input); /* get the & */
3581 nommu_addchr(as_string, ch);
3584 ch = i_getch(input);
3585 nommu_addchr(as_string, ch);
3586 return REDIRFD_CLOSE;
3590 while (ch != EOF && isdigit(ch)) {
3591 d = d*10 + (ch-'0');
3593 ch = i_getch(input);
3594 nommu_addchr(as_string, ch);
3599 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3601 bb_error_msg("ambiguous redirect");
3602 return REDIRFD_SYNTAX_ERR;
3605 /* Return code is 0 normal, 1 if a syntax error is detected
3607 static int parse_redirect(struct parse_context *ctx,
3610 struct in_str *input)
3612 struct command *command = ctx->command;
3613 struct redir_struct *redir;
3614 struct redir_struct **redirp;
3617 dup_num = REDIRFD_TO_FILE;
3618 if (style != REDIRECT_HEREDOC) {
3619 /* Check for a '>&1' type redirect */
3620 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3621 if (dup_num == REDIRFD_SYNTAX_ERR)
3624 int ch = i_peek(input);
3625 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3626 if (dup_num) { /* <<-... */
3627 ch = i_getch(input);
3628 nommu_addchr(&ctx->as_string, ch);
3633 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3634 int ch = i_peek(input);
3636 /* >|FILE redirect ("clobbering" >).
3637 * Since we do not support "set -o noclobber" yet,
3638 * >| and > are the same for now. Just eat |.
3640 ch = i_getch(input);
3641 nommu_addchr(&ctx->as_string, ch);
3645 /* Create a new redir_struct and append it to the linked list */
3646 redirp = &command->redirects;
3647 while ((redir = *redirp) != NULL) {
3648 redirp = &(redir->next);
3650 *redirp = redir = xzalloc(sizeof(*redir));
3651 /* redir->next = NULL; */
3652 /* redir->rd_filename = NULL; */
3653 redir->rd_type = style;
3654 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3656 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3657 redir_table[style].descrip);
3659 redir->rd_dup = dup_num;
3660 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3661 /* Erik had a check here that the file descriptor in question
3662 * is legit; I postpone that to "run time"
3663 * A "-" representation of "close me" shows up as a -3 here */
3664 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3665 redir->rd_fd, redir->rd_dup);
3667 #if 0 /* Instead we emit error message at run time */
3668 if (ctx->pending_redirect) {
3669 /* For example, "cmd > <file" */
3670 die_if_script("syntax error: %s", "invalid redirect");
3673 /* Set ctx->pending_redirect, so we know what to do at the
3674 * end of the next parsed word. */
3675 ctx->pending_redirect = redir;
3680 /* If a redirect is immediately preceded by a number, that number is
3681 * supposed to tell which file descriptor to redirect. This routine
3682 * looks for such preceding numbers. In an ideal world this routine
3683 * needs to handle all the following classes of redirects...
3684 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3685 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3686 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3687 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3689 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3691 * ... If n is quoted, the number shall not be recognized as part of
3692 * the redirection expression. For example:
3694 * writes the character 2 into file a"
3695 * We are getting it right by setting ->has_quoted_part on any \<char>
3697 * A -1 return means no valid number was found,
3698 * the caller should use the appropriate default for this redirection.
3700 static int redirect_opt_num(o_string *o)
3704 if (o->data == NULL)
3706 num = bb_strtou(o->data, NULL, 10);
3707 if (errno || num < 0)
3709 o_reset_to_empty_unquoted(o);
3714 #define fetch_till_str(as_string, input, word, skip_tabs) \
3715 fetch_till_str(input, word, skip_tabs)
3717 static char *fetch_till_str(o_string *as_string,
3718 struct in_str *input,
3722 o_string heredoc = NULL_O_STRING;
3724 int prev = 0; /* not \ */
3730 ch = i_getch(input);
3732 nommu_addchr(as_string, ch);
3733 if ((ch == '\n' || ch == EOF)
3734 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3736 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3737 heredoc.data[past_EOL] = '\0';
3738 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3739 return heredoc.data;
3741 while (ch == '\n') {
3742 o_addchr(&heredoc, ch);
3745 past_EOL = heredoc.length;
3747 ch = i_getch(input);
3749 nommu_addchr(as_string, ch);
3750 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3754 o_free_unsafe(&heredoc);
3757 o_addchr(&heredoc, ch);
3758 nommu_addchr(as_string, ch);
3759 if (prev == '\\' && ch == '\\')
3760 /* Correctly handle foo\\<eol> (not a line cont.) */
3761 prev = 0; /* not \ */
3767 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3768 * and load them all. There should be exactly heredoc_cnt of them.
3770 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3772 struct pipe *pi = ctx->list_head;
3774 while (pi && heredoc_cnt) {
3776 struct command *cmd = pi->cmds;
3778 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3780 cmd->argv ? cmd->argv[0] : "NONE");
3781 for (i = 0; i < pi->num_cmds; i++) {
3782 struct redir_struct *redir = cmd->redirects;
3784 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3785 i, cmd->argv ? cmd->argv[0] : "NONE");
3787 if (redir->rd_type == REDIRECT_HEREDOC) {
3790 redir->rd_type = REDIRECT_HEREDOC2;
3791 /* redir->rd_dup is (ab)used to indicate <<- */
3792 p = fetch_till_str(&ctx->as_string, input,
3793 redir->rd_filename, redir->rd_dup);
3795 syntax_error("unexpected EOF in here document");
3798 free(redir->rd_filename);
3799 redir->rd_filename = p;
3802 redir = redir->next;
3809 /* Should be 0. If it isn't, it's a parse error */
3811 bb_error_msg_and_die("heredoc BUG 2");
3817 static int run_list(struct pipe *pi);
3819 #define parse_stream(pstring, input, end_trigger) \
3820 parse_stream(input, end_trigger)
3822 static struct pipe *parse_stream(char **pstring,
3823 struct in_str *input,
3827 #if !ENABLE_HUSH_FUNCTIONS
3828 #define parse_group(dest, ctx, input, ch) \
3829 parse_group(ctx, input, ch)
3831 static int parse_group(o_string *dest, struct parse_context *ctx,
3832 struct in_str *input, int ch)
3834 /* dest contains characters seen prior to ( or {.
3835 * Typically it's empty, but for function defs,
3836 * it contains function name (without '()'). */
3837 struct pipe *pipe_list;
3839 struct command *command = ctx->command;
3841 debug_printf_parse("parse_group entered\n");
3842 #if ENABLE_HUSH_FUNCTIONS
3843 if (ch == '(' && !dest->has_quoted_part) {
3845 if (done_word(dest, ctx))
3848 goto skip; /* (... */
3849 if (command->argv[1]) { /* word word ... (... */
3850 syntax_error_unexpected_ch('(');
3853 /* it is "word(..." or "word (..." */
3855 ch = i_getch(input);
3856 while (ch == ' ' || ch == '\t');
3858 syntax_error_unexpected_ch(ch);
3861 nommu_addchr(&ctx->as_string, ch);
3863 ch = i_getch(input);
3864 while (ch == ' ' || ch == '\t' || ch == '\n');
3866 syntax_error_unexpected_ch(ch);
3869 nommu_addchr(&ctx->as_string, ch);
3870 command->cmd_type = CMD_FUNCDEF;
3875 #if 0 /* Prevented by caller */
3876 if (command->argv /* word [word]{... */
3877 || dest->length /* word{... */
3878 || dest->has_quoted_part /* ""{... */
3881 debug_printf_parse("parse_group return 1: "
3882 "syntax error, groups and arglists don't mix\n");
3887 #if ENABLE_HUSH_FUNCTIONS
3893 command->cmd_type = CMD_SUBSHELL;
3895 /* bash does not allow "{echo...", requires whitespace */
3896 ch = i_getch(input);
3897 if (ch != ' ' && ch != '\t' && ch != '\n') {
3898 syntax_error_unexpected_ch(ch);
3901 nommu_addchr(&ctx->as_string, ch);
3906 # define as_string NULL
3908 char *as_string = NULL;
3910 pipe_list = parse_stream(&as_string, input, endch);
3913 o_addstr(&ctx->as_string, as_string);
3915 /* empty ()/{} or parse error? */
3916 if (!pipe_list || pipe_list == ERR_PTR) {
3917 /* parse_stream already emitted error msg */
3920 debug_printf_parse("parse_group return 1: "
3921 "parse_stream returned %p\n", pipe_list);
3924 command->group = pipe_list;
3926 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3927 command->group_as_string = as_string;
3928 debug_printf_parse("end of group, remembering as:'%s'\n",
3929 command->group_as_string);
3933 debug_printf_parse("parse_group return 0\n");
3935 /* command remains "open", available for possible redirects */
3938 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
3943 ch = i_getch(input);
3946 ch2 = i_peek(input);
3949 /* backslash+newline, skip it */
3954 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
3962 ch2 = i_peek2(input);
3965 /* backslash+newline, skip it */
3971 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3972 /* Subroutines for copying $(...) and `...` things */
3973 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3975 static int add_till_single_quote(o_string *dest, struct in_str *input)
3978 int ch = i_getch(input);
3980 syntax_error_unterm_ch('\'');
3988 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3989 static int add_till_double_quote(o_string *dest, struct in_str *input)
3992 int ch = i_getch(input);
3994 syntax_error_unterm_ch('"');
3999 if (ch == '\\') { /* \x. Copy both chars. */
4001 ch = i_getch(input);
4005 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4010 //if (ch == '$') ...
4013 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4015 * "Within the backquoted style of command substitution, backslash
4016 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4017 * The search for the matching backquote shall be satisfied by the first
4018 * backquote found without a preceding backslash; during this search,
4019 * if a non-escaped backquote is encountered within a shell comment,
4020 * a here-document, an embedded command substitution of the $(command)
4021 * form, or a quoted string, undefined results occur. A single-quoted
4022 * or double-quoted string that begins, but does not end, within the
4023 * "`...`" sequence produces undefined results."
4025 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4027 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4030 int ch = i_getch(input);
4034 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4035 ch = i_getch(input);
4039 && (!in_dquote || ch != '"')
4041 o_addchr(dest, '\\');
4045 syntax_error_unterm_ch('`');
4051 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4052 * quoting and nested ()s.
4053 * "With the $(command) style of command substitution, all characters
4054 * following the open parenthesis to the matching closing parenthesis
4055 * constitute the command. Any valid shell script can be used for command,
4056 * except a script consisting solely of redirections which produces
4057 * unspecified results."
4059 * echo $(echo '(TEST)' BEST) (TEST) BEST
4060 * echo $(echo 'TEST)' BEST) TEST) BEST
4061 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4063 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4064 * can contain arbitrary constructs, just like $(cmd).
4065 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4066 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4068 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4069 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4072 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4073 # if ENABLE_HUSH_BASH_COMPAT
4074 char end_char2 = end_ch >> 8;
4076 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4079 ch = i_getch(input);
4081 syntax_error_unterm_ch(end_ch);
4084 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4087 /* we look for closing )) of $((EXPR)) */
4088 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4089 i_getch(input); /* eat second ')' */
4094 if (ch == '(' || ch == '{') {
4095 ch = (ch == '(' ? ')' : '}');
4096 if (!add_till_closing_bracket(dest, input, ch))
4102 if (!add_till_single_quote(dest, input))
4108 if (!add_till_double_quote(dest, input))
4114 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4120 /* \x. Copy verbatim. Important for \(, \) */
4121 ch = i_getch(input);
4123 syntax_error_unterm_ch(')');
4128 /* "backslash+newline", ignore both */
4129 o_delchr(dest); /* undo insertion of '\' */
4139 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
4141 /* Return code: 0 for OK, 1 for syntax error */
4143 #define parse_dollar(as_string, dest, input, quote_mask) \
4144 parse_dollar(dest, input, quote_mask)
4145 #define as_string NULL
4147 static int parse_dollar(o_string *as_string,
4149 struct in_str *input, unsigned char quote_mask)
4151 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4153 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4155 ch = i_getch(input);
4156 nommu_addchr(as_string, ch);
4158 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4160 debug_printf_parse(": '%c'\n", ch);
4161 o_addchr(dest, ch | quote_mask);
4163 ch = i_peek_and_eat_bkslash_nl(input);
4164 if (!isalnum(ch) && ch != '_') {
4165 /* End of variable name reached */
4168 ch = i_getch(input);
4169 nommu_addchr(as_string, ch);
4171 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4172 } else if (isdigit(ch)) {
4174 ch = i_getch(input);
4175 nommu_addchr(as_string, ch);
4176 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4177 debug_printf_parse(": '%c'\n", ch);
4178 o_addchr(dest, ch | quote_mask);
4179 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4180 } else switch (ch) {
4182 case '!': /* last bg pid */
4183 case '?': /* last exit code */
4184 case '#': /* number of args */
4185 case '*': /* args */
4186 case '@': /* args */
4187 goto make_one_char_var;
4189 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4191 ch = i_getch(input); /* eat '{' */
4192 nommu_addchr(as_string, ch);
4194 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4195 /* It should be ${?}, or ${#var},
4196 * or even ${?+subst} - operator acting on a special variable,
4197 * or the beginning of variable name.
4200 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4203 syntax_error_unterm_str("${name}");
4204 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4207 nommu_addchr(as_string, ch);
4210 /* It's possible to just call add_till_closing_bracket() at this point.
4211 * However, this regresses some of our testsuite cases
4212 * which check invalid constructs like ${%}.
4213 * Oh well... let's check that the var name part is fine... */
4219 debug_printf_parse(": '%c'\n", ch);
4221 ch = i_getch(input);
4222 nommu_addchr(as_string, ch);
4226 if (!isalnum(ch) && ch != '_') {
4228 unsigned char last_ch;
4229 /* handle parameter expansions
4230 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4232 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4233 goto bad_dollar_syntax;
4235 /* Eat everything until closing '}' (or ':') */
4237 if (ENABLE_HUSH_BASH_COMPAT
4239 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4241 /* It's ${var:N[:M]} thing */
4242 end_ch = '}' * 0x100 + ':';
4244 if (ENABLE_HUSH_BASH_COMPAT
4247 /* It's ${var/[/]pattern[/repl]} thing */
4248 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4250 nommu_addchr(as_string, '/');
4253 end_ch = '}' * 0x100 + '/';
4259 #if ENABLE_HUSH_DOLLAR_OPS
4260 last_ch = add_till_closing_bracket(dest, input, end_ch);
4261 if (last_ch == 0) /* error? */
4264 #error Simple code to only allow ${var} is not implemented
4267 o_addstr(as_string, dest->data + pos);
4268 o_addchr(as_string, last_ch);
4271 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4272 /* close the first block: */
4273 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4274 /* while parsing N from ${var:N[:M]}
4275 * or pattern from ${var/[/]pattern[/repl]} */
4276 if ((end_ch & 0xff) == last_ch) {
4277 /* got ':' or '/'- parse the rest */
4282 if (end_ch == '}' * 0x100 + ':') {
4283 /* it's ${var:N} - emulate :999999999 */
4284 o_addstr(dest, "999999999");
4285 } /* else: it's ${var/[/]pattern} */
4290 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4293 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4297 ch = i_getch(input);
4298 nommu_addchr(as_string, ch);
4299 # if ENABLE_SH_MATH_SUPPORT
4300 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4301 ch = i_getch(input);
4302 nommu_addchr(as_string, ch);
4303 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4304 o_addchr(dest, /*quote_mask |*/ '+');
4307 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4308 return 0; /* error */
4310 o_addstr(as_string, dest->data + pos);
4311 o_addchr(as_string, ')');
4312 o_addchr(as_string, ')');
4314 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4318 # if ENABLE_HUSH_TICK
4319 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4320 o_addchr(dest, quote_mask | '`');
4323 if (!add_till_closing_bracket(dest, input, ')'))
4324 return 0; /* error */
4326 o_addstr(as_string, dest->data + pos);
4327 o_addchr(as_string, ')');
4329 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4335 ch = i_getch(input);
4336 nommu_addchr(as_string, ch);
4337 ch = i_peek_and_eat_bkslash_nl(input);
4338 if (isalnum(ch)) { /* it's $_name or $_123 */
4343 /* TODO: $_ and $-: */
4344 /* $_ Shell or shell script name; or last argument of last command
4345 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4346 * but in command's env, set to full pathname used to invoke it */
4347 /* $- Option flags set by set builtin or shell options (-i etc) */
4349 o_addQchr(dest, '$');
4351 debug_printf_parse("parse_dollar return 1 (ok)\n");
4357 # if ENABLE_HUSH_BASH_COMPAT
4358 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4359 encode_string(dest, input, dquote_end, process_bkslash)
4361 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4362 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4363 encode_string(dest, input, dquote_end)
4365 #define as_string NULL
4369 # if ENABLE_HUSH_BASH_COMPAT
4370 /* all parameters are needed, no macro tricks */
4372 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4373 encode_string(as_string, dest, input, dquote_end)
4376 static int encode_string(o_string *as_string,
4378 struct in_str *input,
4380 int process_bkslash)
4382 #if !ENABLE_HUSH_BASH_COMPAT
4383 const int process_bkslash = 1;
4389 ch = i_getch(input);
4391 nommu_addchr(as_string, ch);
4392 if (ch == dquote_end) { /* may be only '"' or EOF */
4393 debug_printf_parse("encode_string return 1 (ok)\n");
4396 /* note: can't move it above ch == dquote_end check! */
4398 syntax_error_unterm_ch('"');
4399 return 0; /* error */
4403 next = i_peek(input);
4405 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4406 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4407 if (process_bkslash && ch == '\\') {
4409 syntax_error("\\<eof>");
4413 * "The backslash retains its special meaning [in "..."]
4414 * only when followed by one of the following characters:
4415 * $, `, ", \, or <newline>. A double quote may be quoted
4416 * within double quotes by preceding it with a backslash."
4417 * NB: in (unquoted) heredoc, above does not apply to ",
4418 * therefore we check for it by "next == dquote_end" cond.
4420 if (next == dquote_end || strchr("$`\\\n", next)) {
4421 ch = i_getch(input); /* eat next */
4423 goto again; /* skip \<newline> */
4424 } /* else: ch remains == '\\', and we double it below: */
4425 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4426 nommu_addchr(as_string, ch);
4430 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4431 debug_printf_parse("encode_string return 0: "
4432 "parse_dollar returned 0 (error)\n");
4437 #if ENABLE_HUSH_TICK
4439 //unsigned pos = dest->length;
4440 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4441 o_addchr(dest, 0x80 | '`');
4442 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4443 return 0; /* error */
4444 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4445 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4449 o_addQchr(dest, ch);
4455 * Scan input until EOF or end_trigger char.
4456 * Return a list of pipes to execute, or NULL on EOF
4457 * or if end_trigger character is met.
4458 * On syntax error, exit if shell is not interactive,
4459 * reset parsing machinery and start parsing anew,
4460 * or return ERR_PTR.
4462 static struct pipe *parse_stream(char **pstring,
4463 struct in_str *input,
4466 struct parse_context ctx;
4467 o_string dest = NULL_O_STRING;
4470 /* Single-quote triggers a bypass of the main loop until its mate is
4471 * found. When recursing, quote state is passed in via dest->o_expflags.
4473 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4474 end_trigger ? end_trigger : 'X');
4477 /* If very first arg is "" or '', dest.data may end up NULL.
4478 * Preventing this: */
4479 o_addchr(&dest, '\0');
4482 /* We used to separate words on $IFS here. This was wrong.
4483 * $IFS is used only for word splitting when $var is expanded,
4484 * here we should use blank chars as separators, not $IFS
4487 if (MAYBE_ASSIGNMENT != 0)
4488 dest.o_assignment = MAYBE_ASSIGNMENT;
4489 initialize_context(&ctx);
4492 const char *is_blank;
4493 const char *is_special;
4497 redir_type redir_style;
4499 ch = i_getch(input);
4500 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4501 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4506 syntax_error_unterm_str("here document");
4509 /* end_trigger == '}' case errors out earlier,
4510 * checking only ')' */
4511 if (end_trigger == ')') {
4512 syntax_error_unterm_ch('(');
4516 if (done_word(&dest, &ctx)) {
4520 done_pipe(&ctx, PIPE_SEQ);
4522 /* If we got nothing... */
4523 /* (this makes bare "&" cmd a no-op.
4524 * bash says: "syntax error near unexpected token '&'") */
4525 if (pi->num_cmds == 0
4526 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4532 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4534 *pstring = ctx.as_string.data;
4536 o_free_unsafe(&ctx.as_string);
4539 debug_printf_parse("parse_stream return %p\n", pi);
4542 nommu_addchr(&ctx.as_string, ch);
4546 next = i_peek(input);
4548 is_special = "{}<>;&|()#'" /* special outside of "str" */
4549 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4550 /* Are { and } special here? */
4551 if (ctx.command->argv /* word [word]{... - non-special */
4552 || dest.length /* word{... - non-special */
4553 || dest.has_quoted_part /* ""{... - non-special */
4554 || (next != ';' /* }; - special */
4555 && next != ')' /* }) - special */
4556 && next != '&' /* }& and }&& ... - special */
4557 && next != '|' /* }|| ... - special */
4558 && !strchr(defifs, next) /* {word - non-special */
4561 /* They are not special, skip "{}" */
4564 is_special = strchr(is_special, ch);
4565 is_blank = strchr(defifs, ch);
4567 if (!is_special && !is_blank) { /* ordinary char */
4569 o_addQchr(&dest, ch);
4570 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4571 || dest.o_assignment == WORD_IS_KEYWORD)
4573 && is_well_formed_var_name(dest.data, '=')
4575 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4576 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4582 if (done_word(&dest, &ctx)) {
4586 /* Is this a case when newline is simply ignored?
4588 * "cmd | <newline> cmd ..."
4589 * "case ... in <newline> word) ..."
4591 if (IS_NULL_CMD(ctx.command)
4592 && dest.length == 0 && !dest.has_quoted_part
4594 /* This newline can be ignored. But...
4595 * Without check #1, interactive shell
4596 * ignores even bare <newline>,
4597 * and shows the continuation prompt:
4598 * ps1_prompt$ <enter>
4599 * ps2> _ <=== wrong, should be ps1
4600 * Without check #2, "cmd & <newline>"
4601 * is similarly mistreated.
4602 * (BTW, this makes "cmd & cmd"
4603 * and "cmd && cmd" non-orthogonal.
4604 * Really, ask yourself, why
4605 * "cmd && <newline>" doesn't start
4606 * cmd but waits for more input?
4609 struct pipe *pi = ctx.list_head;
4610 if (pi->num_cmds != 0 /* check #1 */
4611 && pi->followup != PIPE_BG /* check #2 */
4616 /* Treat newline as a command separator. */
4617 done_pipe(&ctx, PIPE_SEQ);
4618 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4620 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4625 dest.o_assignment = MAYBE_ASSIGNMENT;
4626 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4628 /* note: if (is_blank) continue;
4629 * will still trigger for us */
4633 /* "cmd}" or "cmd }..." without semicolon or &:
4634 * } is an ordinary char in this case, even inside { cmd; }
4635 * Pathological example: { ""}; } should exec "}" cmd
4638 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4639 || dest.length != 0 /* word} */
4640 || dest.has_quoted_part /* ""} */
4644 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4645 goto skip_end_trigger;
4646 /* else: } does terminate a group */
4649 if (end_trigger && end_trigger == ch
4650 && (ch != ';' || heredoc_cnt == 0)
4651 #if ENABLE_HUSH_CASE
4653 || ctx.ctx_res_w != RES_MATCH
4654 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4659 /* This is technically valid:
4660 * { cat <<HERE; }; echo Ok
4664 * but we don't support this.
4665 * We require heredoc to be in enclosing {}/(),
4668 syntax_error_unterm_str("here document");
4671 if (done_word(&dest, &ctx)) {
4674 done_pipe(&ctx, PIPE_SEQ);
4675 dest.o_assignment = MAYBE_ASSIGNMENT;
4676 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4677 /* Do we sit outside of any if's, loops or case's? */
4679 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4683 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4685 *pstring = ctx.as_string.data;
4687 o_free_unsafe(&ctx.as_string);
4690 debug_printf_parse("parse_stream return %p: "
4691 "end_trigger char found\n",
4693 return ctx.list_head;
4700 /* Catch <, > before deciding whether this word is
4701 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4704 redir_fd = redirect_opt_num(&dest);
4705 if (done_word(&dest, &ctx)) {
4708 redir_style = REDIRECT_OVERWRITE;
4710 redir_style = REDIRECT_APPEND;
4711 ch = i_getch(input);
4712 nommu_addchr(&ctx.as_string, ch);
4715 else if (next == '(') {
4716 syntax_error(">(process) not supported");
4720 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4722 continue; /* back to top of while (1) */
4724 redir_fd = redirect_opt_num(&dest);
4725 if (done_word(&dest, &ctx)) {
4728 redir_style = REDIRECT_INPUT;
4730 redir_style = REDIRECT_HEREDOC;
4732 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4733 ch = i_getch(input);
4734 nommu_addchr(&ctx.as_string, ch);
4735 } else if (next == '>') {
4736 redir_style = REDIRECT_IO;
4737 ch = i_getch(input);
4738 nommu_addchr(&ctx.as_string, ch);
4741 else if (next == '(') {
4742 syntax_error("<(process) not supported");
4746 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4748 continue; /* back to top of while (1) */
4750 if (dest.length == 0 && !dest.has_quoted_part) {
4751 /* skip "#comment" */
4754 if (ch == EOF || ch == '\n')
4757 /* note: we do not add it to &ctx.as_string */
4759 nommu_addchr(&ctx.as_string, '\n');
4760 continue; /* back to top of while (1) */
4765 /* It's "\<newline>" */
4767 /* Remove trailing '\' from ctx.as_string */
4768 ctx.as_string.data[--ctx.as_string.length] = '\0';
4770 ch = i_getch(input); /* eat it */
4771 continue; /* back to top of while (1) */
4776 if (dest.o_assignment == MAYBE_ASSIGNMENT
4777 /* check that we are not in word in "a=1 2>word b=1": */
4778 && !ctx.pending_redirect
4780 /* ch is a special char and thus this word
4781 * cannot be an assignment */
4782 dest.o_assignment = NOT_ASSIGNMENT;
4783 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4786 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4789 case '#': /* non-comment #: "echo a#b" etc */
4790 o_addQchr(&dest, ch);
4794 syntax_error("\\<eof>");
4797 ch = i_getch(input);
4798 /* note: ch != '\n' (that case does not reach this place) */
4799 o_addchr(&dest, '\\');
4800 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4801 o_addchr(&dest, ch);
4802 nommu_addchr(&ctx.as_string, ch);
4803 /* Example: echo Hello \2>file
4804 * we need to know that word 2 is quoted */
4805 dest.has_quoted_part = 1;
4808 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4809 debug_printf_parse("parse_stream parse error: "
4810 "parse_dollar returned 0 (error)\n");
4815 dest.has_quoted_part = 1;
4816 if (next == '\'' && !ctx.pending_redirect) {
4817 insert_empty_quoted_str_marker:
4818 nommu_addchr(&ctx.as_string, next);
4819 i_getch(input); /* eat second ' */
4820 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4821 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4824 ch = i_getch(input);
4826 syntax_error_unterm_ch('\'');
4829 nommu_addchr(&ctx.as_string, ch);
4832 o_addqchr(&dest, ch);
4837 dest.has_quoted_part = 1;
4838 if (next == '"' && !ctx.pending_redirect)
4839 goto insert_empty_quoted_str_marker;
4840 if (dest.o_assignment == NOT_ASSIGNMENT)
4841 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4842 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4844 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4846 #if ENABLE_HUSH_TICK
4848 USE_FOR_NOMMU(unsigned pos;)
4850 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4851 o_addchr(&dest, '`');
4852 USE_FOR_NOMMU(pos = dest.length;)
4853 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4856 o_addstr(&ctx.as_string, dest.data + pos);
4857 o_addchr(&ctx.as_string, '`');
4859 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4860 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4865 #if ENABLE_HUSH_CASE
4868 if (done_word(&dest, &ctx)) {
4871 done_pipe(&ctx, PIPE_SEQ);
4872 #if ENABLE_HUSH_CASE
4873 /* Eat multiple semicolons, detect
4874 * whether it means something special */
4879 ch = i_getch(input);
4880 nommu_addchr(&ctx.as_string, ch);
4881 if (ctx.ctx_res_w == RES_CASE_BODY) {
4882 ctx.ctx_dsemicolon = 1;
4883 ctx.ctx_res_w = RES_MATCH;
4889 /* We just finished a cmd. New one may start
4890 * with an assignment */
4891 dest.o_assignment = MAYBE_ASSIGNMENT;
4892 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4895 if (done_word(&dest, &ctx)) {
4899 ch = i_getch(input);
4900 nommu_addchr(&ctx.as_string, ch);
4901 done_pipe(&ctx, PIPE_AND);
4903 done_pipe(&ctx, PIPE_BG);
4907 if (done_word(&dest, &ctx)) {
4910 #if ENABLE_HUSH_CASE
4911 if (ctx.ctx_res_w == RES_MATCH)
4912 break; /* we are in case's "word | word)" */
4914 if (next == '|') { /* || */
4915 ch = i_getch(input);
4916 nommu_addchr(&ctx.as_string, ch);
4917 done_pipe(&ctx, PIPE_OR);
4919 /* we could pick up a file descriptor choice here
4920 * with redirect_opt_num(), but bash doesn't do it.
4921 * "echo foo 2| cat" yields "foo 2". */
4926 #if ENABLE_HUSH_CASE
4927 /* "case... in [(]word)..." - skip '(' */
4928 if (ctx.ctx_res_w == RES_MATCH
4929 && ctx.command->argv == NULL /* not (word|(... */
4930 && dest.length == 0 /* not word(... */
4931 && dest.has_quoted_part == 0 /* not ""(... */
4937 if (parse_group(&dest, &ctx, input, ch) != 0) {
4942 #if ENABLE_HUSH_CASE
4943 if (ctx.ctx_res_w == RES_MATCH)
4947 /* proper use of this character is caught by end_trigger:
4948 * if we see {, we call parse_group(..., end_trigger='}')
4949 * and it will match } earlier (not here). */
4950 syntax_error_unexpected_ch(ch);
4954 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4960 struct parse_context *pctx;
4961 IF_HAS_KEYWORDS(struct parse_context *p2;)
4963 /* Clean up allocated tree.
4964 * Sample for finding leaks on syntax error recovery path.
4965 * Run it from interactive shell, watch pmap `pidof hush`.
4966 * while if false; then false; fi; do break; fi
4967 * Samples to catch leaks at execution:
4968 * while if (true | {true;}); then echo ok; fi; do break; done
4969 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4973 /* Update pipe/command counts,
4974 * otherwise freeing may miss some */
4975 done_pipe(pctx, PIPE_SEQ);
4976 debug_printf_clean("freeing list %p from ctx %p\n",
4977 pctx->list_head, pctx);
4978 debug_print_tree(pctx->list_head, 0);
4979 free_pipe_list(pctx->list_head);
4980 debug_printf_clean("freed list %p\n", pctx->list_head);
4982 o_free_unsafe(&pctx->as_string);
4984 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4988 IF_HAS_KEYWORDS(pctx = p2;)
4989 } while (HAS_KEYWORDS && pctx);
4992 G.last_exitcode = 1;
5003 /*** Execution routines ***/
5005 /* Expansion can recurse, need forward decls: */
5006 #if !ENABLE_HUSH_BASH_COMPAT
5007 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5008 #define expand_string_to_string(str, do_unbackslash) \
5009 expand_string_to_string(str)
5011 static char *expand_string_to_string(const char *str, int do_unbackslash);
5012 #if ENABLE_HUSH_TICK
5013 static int process_command_subs(o_string *dest, const char *s);
5016 /* expand_strvec_to_strvec() takes a list of strings, expands
5017 * all variable references within and returns a pointer to
5018 * a list of expanded strings, possibly with larger number
5019 * of strings. (Think VAR="a b"; echo $VAR).
5020 * This new list is allocated as a single malloc block.
5021 * NULL-terminated list of char* pointers is at the beginning of it,
5022 * followed by strings themselves.
5023 * Caller can deallocate entire list by single free(list). */
5025 /* A horde of its helpers come first: */
5027 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5029 while (--len >= 0) {
5032 #if ENABLE_HUSH_BRACE_EXPANSION
5033 if (c == '{' || c == '}') {
5034 /* { -> \{, } -> \} */
5036 /* And now we want to add { or } and continue:
5039 * luckily, just falling throught achieves this.
5045 /* \z -> \\\z; \<eol> -> \\<eol> */
5050 o_addchr(o, *str++);
5056 /* Store given string, finalizing the word and starting new one whenever
5057 * we encounter IFS char(s). This is used for expanding variable values.
5058 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5059 * Return in *ended_with_ifs:
5060 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5062 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5064 int last_is_ifs = 0;
5069 if (!*str) /* EOL - do not finalize word */
5071 word_len = strcspn(str, G.ifs);
5073 /* We have WORD_LEN leading non-IFS chars */
5074 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5075 o_addblock(output, str, word_len);
5077 /* Protect backslashes against globbing up :)
5078 * Example: "v='\*'; echo b$v" prints "b\*"
5079 * (and does not try to glob on "*")
5081 o_addblock_duplicate_backslash(output, str, word_len);
5082 /*/ Why can't we do it easier? */
5083 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5084 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5088 if (!*str) /* EOL - do not finalize word */
5092 /* We know str here points to at least one IFS char */
5094 str += strspn(str, G.ifs); /* skip IFS chars */
5095 if (!*str) /* EOL - do not finalize word */
5098 /* Start new word... but not always! */
5099 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5100 if (output->has_quoted_part
5101 /* Case "v=' a'; echo $v":
5102 * here nothing precedes the space in $v expansion,
5103 * therefore we should not finish the word
5104 * (IOW: if there *is* word to finalize, only then do it):
5106 || (n > 0 && output->data[output->length - 1])
5108 o_addchr(output, '\0');
5109 debug_print_list("expand_on_ifs", output, n);
5110 n = o_save_ptr(output, n);
5115 *ended_with_ifs = last_is_ifs;
5116 debug_print_list("expand_on_ifs[1]", output, n);
5120 /* Helper to expand $((...)) and heredoc body. These act as if
5121 * they are in double quotes, with the exception that they are not :).
5122 * Just the rules are similar: "expand only $var and `cmd`"
5124 * Returns malloced string.
5125 * As an optimization, we return NULL if expansion is not needed.
5127 #if !ENABLE_HUSH_BASH_COMPAT
5128 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5129 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5130 encode_then_expand_string(str)
5132 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5135 struct in_str input;
5136 o_string dest = NULL_O_STRING;
5138 if (!strchr(str, '$')
5139 && !strchr(str, '\\')
5140 #if ENABLE_HUSH_TICK
5141 && !strchr(str, '`')
5147 /* We need to expand. Example:
5148 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5150 setup_string_in_str(&input, str);
5151 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5152 //TODO: error check (encode_string returns 0 on error)?
5153 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5154 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5155 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5156 o_free_unsafe(&dest);
5160 #if ENABLE_SH_MATH_SUPPORT
5161 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5163 arith_state_t math_state;
5167 math_state.lookupvar = get_local_var_value;
5168 math_state.setvar = set_local_var_from_halves;
5169 //math_state.endofname = endofname;
5170 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5171 res = arith(&math_state, exp_str ? exp_str : arg);
5174 *errmsg_p = math_state.errmsg;
5175 if (math_state.errmsg)
5176 die_if_script(math_state.errmsg);
5181 #if ENABLE_HUSH_BASH_COMPAT
5182 /* ${var/[/]pattern[/repl]} helpers */
5183 static char *strstr_pattern(char *val, const char *pattern, int *size)
5186 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5187 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5194 /* Optimization: if "*pat" did not match the start of "string",
5195 * we know that "tring", "ring" etc will not match too:
5197 if (pattern[0] == '*')
5202 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5204 char *result = NULL;
5205 unsigned res_len = 0;
5206 unsigned repl_len = strlen(repl);
5210 char *s = strstr_pattern(val, pattern, &size);
5214 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5215 memcpy(result + res_len, val, s - val);
5217 strcpy(result + res_len, repl);
5218 res_len += repl_len;
5219 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5225 if (val[0] && result) {
5226 result = xrealloc(result, res_len + strlen(val) + 1);
5227 strcpy(result + res_len, val);
5228 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5230 debug_printf_varexp("result:'%s'\n", result);
5236 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5238 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5240 const char *val = NULL;
5241 char *to_be_freed = NULL;
5246 char exp_save = exp_save; /* for compiler */
5247 char *exp_saveptr; /* points to expansion operator */
5248 char *exp_word = exp_word; /* for compiler */
5251 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5253 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5255 first_char = arg[0] = arg0 & 0x7f;
5258 if (first_char == '#' /* ${#... */
5259 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5261 /* It must be length operator: ${#var} */
5265 /* Maybe handle parameter expansion */
5266 if (exp_saveptr /* if 2nd char is one of expansion operators */
5267 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5269 /* ${?:0}, ${#[:]%0} etc */
5270 exp_saveptr = var + 1;
5272 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5273 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5275 exp_op = exp_save = *exp_saveptr;
5277 exp_word = exp_saveptr + 1;
5278 if (exp_op == ':') {
5279 exp_op = *exp_word++;
5280 //TODO: try ${var:} and ${var:bogus} in non-bash config
5281 if (ENABLE_HUSH_BASH_COMPAT
5282 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5284 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5289 *exp_saveptr = '\0';
5290 } /* else: it's not an expansion op, but bare ${var} */
5293 /* Look up the variable in question */
5294 if (isdigit(var[0])) {
5295 /* parse_dollar should have vetted var for us */
5296 int n = xatoi_positive(var);
5297 if (n < G.global_argc)
5298 val = G.global_argv[n];
5299 /* else val remains NULL: $N with too big N */
5303 val = utoa(G.root_pid);
5305 case '!': /* bg pid */
5306 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5308 case '?': /* exitcode */
5309 val = utoa(G.last_exitcode);
5311 case '#': /* argc */
5312 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5315 val = get_local_var_value(var);
5319 /* Handle any expansions */
5320 if (exp_op == 'L') {
5321 reinit_unicode_for_hush();
5322 debug_printf_expand("expand: length(%s)=", val);
5323 val = utoa(val ? unicode_strlen(val) : 0);
5324 debug_printf_expand("%s\n", val);
5325 } else if (exp_op) {
5326 if (exp_op == '%' || exp_op == '#') {
5327 /* Standard-mandated substring removal ops:
5328 * ${parameter%word} - remove smallest suffix pattern
5329 * ${parameter%%word} - remove largest suffix pattern
5330 * ${parameter#word} - remove smallest prefix pattern
5331 * ${parameter##word} - remove largest prefix pattern
5333 * Word is expanded to produce a glob pattern.
5334 * Then var's value is matched to it and matching part removed.
5336 if (val && val[0]) {
5340 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5341 if (exp_op == *exp_word) /* ## or %% */
5343 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5345 exp_word = exp_exp_word;
5346 /* HACK ALERT. We depend here on the fact that
5347 * G.global_argv and results of utoa and get_local_var_value
5348 * are actually in writable memory:
5349 * scan_and_match momentarily stores NULs there. */
5351 loc = scan_and_match(t, exp_word, scan_flags);
5352 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5353 // exp_op, t, exp_word, loc);
5355 if (loc) { /* match was found */
5356 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5357 val = loc; /* take right part */
5359 val = to_be_freed = xstrndup(val, loc - val); /* left */
5363 #if ENABLE_HUSH_BASH_COMPAT
5364 else if (exp_op == '/' || exp_op == '\\') {
5365 /* It's ${var/[/]pattern[/repl]} thing.
5366 * Note that in encoded form it has TWO parts:
5367 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5368 * and if // is used, it is encoded as \:
5369 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5371 /* Empty variable always gives nothing: */
5372 // "v=''; echo ${v/*/w}" prints "", not "w"
5373 if (val && val[0]) {
5374 /* pattern uses non-standard expansion.
5375 * repl should be unbackslashed and globbed
5376 * by the usual expansion rules:
5378 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5379 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5380 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5381 * v='a bz'; echo ${v/a*z/\z} prints "z"
5382 * (note that a*z _pattern_ is never globbed!)
5384 char *pattern, *repl, *t;
5385 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5387 pattern = xstrdup(exp_word);
5388 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5389 *p++ = SPECIAL_VAR_SYMBOL;
5391 p = strchr(p, SPECIAL_VAR_SYMBOL);
5393 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5394 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5395 /* HACK ALERT. We depend here on the fact that
5396 * G.global_argv and results of utoa and get_local_var_value
5397 * are actually in writable memory:
5398 * replace_pattern momentarily stores NULs there. */
5400 to_be_freed = replace_pattern(t,
5402 (repl ? repl : exp_word),
5404 if (to_be_freed) /* at least one replace happened */
5411 else if (exp_op == ':') {
5412 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5413 /* It's ${var:N[:M]} bashism.
5414 * Note that in encoded form it has TWO parts:
5415 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5420 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5423 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5424 *p++ = SPECIAL_VAR_SYMBOL;
5426 p = strchr(p, SPECIAL_VAR_SYMBOL);
5428 len = expand_and_evaluate_arith(exp_word, &errmsg);
5431 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5432 if (len >= 0) { /* bash compat: len < 0 is illegal */
5433 if (beg < 0) /* bash compat */
5435 debug_printf_varexp("from val:'%s'\n", val);
5436 if (len == 0 || !val || beg >= strlen(val)) {
5440 /* Paranoia. What if user entered 9999999999999
5441 * which fits in arith_t but not int? */
5444 val = to_be_freed = xstrndup(val + beg, len);
5446 debug_printf_varexp("val:'%s'\n", val);
5450 die_if_script("malformed ${%s:...}", var);
5453 } else { /* one of "-=+?" */
5454 /* Standard-mandated substitution ops:
5455 * ${var?word} - indicate error if unset
5456 * If var is unset, word (or a message indicating it is unset
5457 * if word is null) is written to standard error
5458 * and the shell exits with a non-zero exit status.
5459 * Otherwise, the value of var is substituted.
5460 * ${var-word} - use default value
5461 * If var is unset, word is substituted.
5462 * ${var=word} - assign and use default value
5463 * If var is unset, word is assigned to var.
5464 * In all cases, final value of var is substituted.
5465 * ${var+word} - use alternative value
5466 * If var is unset, null is substituted.
5467 * Otherwise, word is substituted.
5469 * Word is subjected to tilde expansion, parameter expansion,
5470 * command substitution, and arithmetic expansion.
5471 * If word is not needed, it is not expanded.
5473 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5474 * but also treat null var as if it is unset.
5476 int use_word = (!val || ((exp_save == ':') && !val[0]));
5478 use_word = !use_word;
5479 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5480 (exp_save == ':') ? "true" : "false", use_word);
5482 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5484 exp_word = to_be_freed;
5485 if (exp_op == '?') {
5486 /* mimic bash message */
5487 die_if_script("%s: %s",
5489 exp_word[0] ? exp_word : "parameter null or not set"
5491 //TODO: how interactive bash aborts expansion mid-command?
5496 if (exp_op == '=') {
5497 /* ${var=[word]} or ${var:=[word]} */
5498 if (isdigit(var[0]) || var[0] == '#') {
5499 /* mimic bash message */
5500 die_if_script("$%s: cannot assign in this way", var);
5503 char *new_var = xasprintf("%s=%s", var, val);
5504 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5508 } /* one of "-=+?" */
5510 *exp_saveptr = exp_save;
5516 *to_be_freed_pp = to_be_freed;
5520 /* Expand all variable references in given string, adding words to list[]
5521 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5522 * to be filled). This routine is extremely tricky: has to deal with
5523 * variables/parameters with whitespace, $* and $@, and constructs like
5524 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5525 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5527 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5528 * expansion of right-hand side of assignment == 1-element expand.
5530 char cant_be_null = 0; /* only bit 0x80 matters */
5531 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5534 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5535 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5536 debug_print_list("expand_vars_to_list", output, n);
5537 n = o_save_ptr(output, n);
5538 debug_print_list("expand_vars_to_list[0]", output, n);
5540 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5542 char *to_be_freed = NULL;
5543 const char *val = NULL;
5544 #if ENABLE_HUSH_TICK
5545 o_string subst_result = NULL_O_STRING;
5547 #if ENABLE_SH_MATH_SUPPORT
5548 char arith_buf[sizeof(arith_t)*3 + 2];
5552 o_addchr(output, '\0');
5553 n = o_save_ptr(output, n);
5557 o_addblock(output, arg, p - arg);
5558 debug_print_list("expand_vars_to_list[1]", output, n);
5560 p = strchr(p, SPECIAL_VAR_SYMBOL);
5562 /* Fetch special var name (if it is indeed one of them)
5563 * and quote bit, force the bit on if singleword expansion -
5564 * important for not getting v=$@ expand to many words. */
5565 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5567 /* Is this variable quoted and thus expansion can't be null?
5568 * "$@" is special. Even if quoted, it can still
5569 * expand to nothing (not even an empty string),
5570 * thus it is excluded. */
5571 if ((first_ch & 0x7f) != '@')
5572 cant_be_null |= first_ch;
5574 switch (first_ch & 0x7f) {
5575 /* Highest bit in first_ch indicates that var is double-quoted */
5579 if (!G.global_argv[1])
5582 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5583 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5584 while (G.global_argv[i]) {
5585 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5586 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5587 if (G.global_argv[i++][0] && G.global_argv[i]) {
5588 /* this argv[] is not empty and not last:
5589 * put terminating NUL, start new word */
5590 o_addchr(output, '\0');
5591 debug_print_list("expand_vars_to_list[2]", output, n);
5592 n = o_save_ptr(output, n);
5593 debug_print_list("expand_vars_to_list[3]", output, n);
5597 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5598 * and in this case should treat it like '$*' - see 'else...' below */
5599 if (first_ch == ('@'|0x80) /* quoted $@ */
5600 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5603 o_addQstr(output, G.global_argv[i]);
5604 if (++i >= G.global_argc)
5606 o_addchr(output, '\0');
5607 debug_print_list("expand_vars_to_list[4]", output, n);
5608 n = o_save_ptr(output, n);
5610 } else { /* quoted $* (or v="$@" case): add as one word */
5612 o_addQstr(output, G.global_argv[i]);
5613 if (!G.global_argv[++i])
5616 o_addchr(output, G.ifs[0]);
5618 output->has_quoted_part = 1;
5622 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5623 /* "Empty variable", used to make "" etc to not disappear */
5624 output->has_quoted_part = 1;
5626 cant_be_null = 0x80;
5628 #if ENABLE_HUSH_TICK
5629 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5630 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5632 /* Can't just stuff it into output o_string,
5633 * expanded result may need to be globbed
5634 * and $IFS-splitted */
5635 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5636 G.last_exitcode = process_command_subs(&subst_result, arg);
5637 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5638 val = subst_result.data;
5641 #if ENABLE_SH_MATH_SUPPORT
5642 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5645 arg++; /* skip '+' */
5646 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5647 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5648 res = expand_and_evaluate_arith(arg, NULL);
5649 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5650 sprintf(arith_buf, ARITH_FMT, res);
5656 val = expand_one_var(&to_be_freed, arg, &p);
5657 IF_HUSH_TICK(store_val:)
5658 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5659 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5660 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5661 if (val && val[0]) {
5662 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5665 } else { /* quoted $VAR, val will be appended below */
5666 output->has_quoted_part = 1;
5667 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5668 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5671 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5673 if (val && val[0]) {
5674 o_addQstr(output, val);
5678 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5679 * Do the check to avoid writing to a const string. */
5680 if (*p != SPECIAL_VAR_SYMBOL)
5681 *p = SPECIAL_VAR_SYMBOL;
5683 #if ENABLE_HUSH_TICK
5684 o_free(&subst_result);
5687 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5691 o_addchr(output, '\0');
5692 n = o_save_ptr(output, n);
5694 debug_print_list("expand_vars_to_list[a]", output, n);
5695 /* this part is literal, and it was already pre-quoted
5696 * if needed (much earlier), do not use o_addQstr here! */
5697 o_addstr_with_NUL(output, arg);
5698 debug_print_list("expand_vars_to_list[b]", output, n);
5699 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5700 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5703 /* allow to reuse list[n] later without re-growth */
5704 output->has_empty_slot = 1;
5706 o_addchr(output, '\0');
5712 static char **expand_variables(char **argv, unsigned expflags)
5716 o_string output = NULL_O_STRING;
5718 output.o_expflags = expflags;
5722 n = expand_vars_to_list(&output, n, *argv);
5725 debug_print_list("expand_variables", &output, n);
5727 /* output.data (malloced in one block) gets returned in "list" */
5728 list = o_finalize_list(&output, n);
5729 debug_print_strings("expand_variables[1]", list);
5733 static char **expand_strvec_to_strvec(char **argv)
5735 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5738 #if ENABLE_HUSH_BASH_COMPAT
5739 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5741 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5745 /* Used for expansion of right hand of assignments,
5746 * $((...)), heredocs, variable espansion parts.
5748 * NB: should NOT do globbing!
5749 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5751 static char *expand_string_to_string(const char *str, int do_unbackslash)
5753 #if !ENABLE_HUSH_BASH_COMPAT
5754 const int do_unbackslash = 1;
5756 char *argv[2], **list;
5758 debug_printf_expand("string_to_string<='%s'\n", str);
5759 /* This is generally an optimization, but it also
5760 * handles "", which otherwise trips over !list[0] check below.
5761 * (is this ever happens that we actually get str="" here?)
5763 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5764 //TODO: Can use on strings with \ too, just unbackslash() them?
5765 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5766 return xstrdup(str);
5769 argv[0] = (char*)str;
5771 list = expand_variables(argv, do_unbackslash
5772 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5773 : EXP_FLAG_SINGLEWORD
5776 if (!list[0] || list[1])
5777 bb_error_msg_and_die("BUG in varexp2");
5778 /* actually, just move string 2*sizeof(char*) bytes back */
5779 overlapping_strcpy((char*)list, list[0]);
5781 unbackslash((char*)list);
5782 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5786 /* Used for "eval" builtin */
5787 static char* expand_strvec_to_string(char **argv)
5791 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5792 /* Convert all NULs to spaces */
5797 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5798 bb_error_msg_and_die("BUG in varexp3");
5799 /* bash uses ' ' regardless of $IFS contents */
5804 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5805 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5809 static char **expand_assignments(char **argv, int count)
5814 G.expanded_assignments = p = NULL;
5815 /* Expand assignments into one string each */
5816 for (i = 0; i < count; i++) {
5817 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5819 G.expanded_assignments = NULL;
5824 static void switch_off_special_sigs(unsigned mask)
5827 while ((mask >>= 1) != 0) {
5832 if (G.traps[sig] && !G.traps[sig][0])
5833 /* trap is '', has to remain SIG_IGN */
5836 G.traps[sig] = NULL;
5838 /* We are here only if no trap or trap was not '' */
5839 install_sighandler(sig, SIG_DFL);
5845 void re_execute_shell(char ***to_free, const char *s,
5846 char *g_argv0, char **g_argv,
5847 char **builtin_argv) NORETURN;
5849 static void reset_traps_to_defaults(void)
5851 /* This function is always called in a child shell
5852 * after fork (not vfork, NOMMU doesn't use this function).
5857 /* Child shells are not interactive.
5858 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5859 * Testcase: (while :; do :; done) + ^Z should background.
5860 * Same goes for SIGTERM, SIGHUP, SIGINT.
5862 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5863 if (!G.traps && !mask)
5864 return; /* already no traps and no special sigs */
5866 /* Switch off special sigs */
5867 switch_off_special_sigs(mask);
5869 G_fatal_sig_mask = 0;
5871 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5872 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5873 * remain set in G.special_sig_mask */
5878 /* Reset all sigs to default except ones with empty traps */
5879 for (sig = 0; sig < NSIG; sig++) {
5881 continue; /* no trap: nothing to do */
5882 if (!G.traps[sig][0])
5883 continue; /* empty trap: has to remain SIG_IGN */
5884 /* sig has non-empty trap, reset it: */
5886 G.traps[sig] = NULL;
5887 /* There is no signal for trap 0 (EXIT) */
5890 install_sighandler(sig, pick_sighandler(sig));
5896 static void re_execute_shell(char ***to_free, const char *s,
5897 char *g_argv0, char **g_argv,
5898 char **builtin_argv) NORETURN;
5899 static void re_execute_shell(char ***to_free, const char *s,
5900 char *g_argv0, char **g_argv,
5901 char **builtin_argv)
5903 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5904 /* delims + 2 * (number of bytes in printed hex numbers) */
5905 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5906 char *heredoc_argv[4];
5907 struct variable *cur;
5908 # if ENABLE_HUSH_FUNCTIONS
5909 struct function *funcp;
5913 unsigned long long empty_trap_mask;
5915 if (!g_argv0) { /* heredoc */
5916 argv = heredoc_argv;
5917 argv[0] = (char *) G.argv0_for_re_execing;
5918 argv[1] = (char *) "-<";
5919 argv[2] = (char *) s;
5921 pp = &argv[3]; /* used as pointer to empty environment */
5927 if (pp) while (*pp++)
5930 empty_trap_mask = 0;
5933 for (sig = 1; sig < NSIG; sig++) {
5934 if (G.traps[sig] && !G.traps[sig][0])
5935 empty_trap_mask |= 1LL << sig;
5939 sprintf(param_buf, NOMMU_HACK_FMT
5940 , (unsigned) G.root_pid
5941 , (unsigned) G.root_ppid
5942 , (unsigned) G.last_bg_pid
5943 , (unsigned) G.last_exitcode
5946 IF_HUSH_LOOPS(, G.depth_of_loop)
5948 # undef NOMMU_HACK_FMT
5949 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5950 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5953 for (cur = G.top_var; cur; cur = cur->next) {
5954 if (!cur->flg_export || cur->flg_read_only)
5957 # if ENABLE_HUSH_FUNCTIONS
5958 for (funcp = G.top_func; funcp; funcp = funcp->next)
5964 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5965 *pp++ = (char *) G.argv0_for_re_execing;
5967 for (cur = G.top_var; cur; cur = cur->next) {
5968 if (strcmp(cur->varstr, hush_version_str) == 0)
5970 if (cur->flg_read_only) {
5971 *pp++ = (char *) "-R";
5972 *pp++ = cur->varstr;
5973 } else if (!cur->flg_export) {
5974 *pp++ = (char *) "-V";
5975 *pp++ = cur->varstr;
5978 # if ENABLE_HUSH_FUNCTIONS
5979 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5980 *pp++ = (char *) "-F";
5981 *pp++ = funcp->name;
5982 *pp++ = funcp->body_as_string;
5985 /* We can pass activated traps here. Say, -Tnn:trap_string
5987 * However, POSIX says that subshells reset signals with traps
5989 * I tested bash-3.2 and it not only does that with true subshells
5990 * of the form ( list ), but with any forked children shells.
5991 * I set trap "echo W" WINCH; and then tried:
5993 * { echo 1; sleep 20; echo 2; } &
5994 * while true; do echo 1; sleep 20; echo 2; break; done &
5995 * true | { echo 1; sleep 20; echo 2; } | cat
5997 * In all these cases sending SIGWINCH to the child shell
5998 * did not run the trap. If I add trap "echo V" WINCH;
5999 * _inside_ group (just before echo 1), it works.
6001 * I conclude it means we don't need to pass active traps here.
6003 *pp++ = (char *) "-c";
6006 while (*++builtin_argv)
6007 *pp++ = *builtin_argv;
6008 *pp++ = (char *) "";
6013 /* *pp = NULL; - is already there */
6017 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6018 /* Don't propagate SIG_IGN to the child */
6019 if (SPECIAL_JOBSTOP_SIGS != 0)
6020 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6021 execve(bb_busybox_exec_path, argv, pp);
6022 /* Fallback. Useful for init=/bin/hush usage etc */
6023 if (argv[0][0] == '/')
6024 execve(argv[0], argv, pp);
6025 xfunc_error_retval = 127;
6026 bb_error_msg_and_die("can't re-execute the shell");
6028 #endif /* !BB_MMU */
6031 static int run_and_free_list(struct pipe *pi);
6033 /* Executing from string: eval, sh -c '...'
6034 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6035 * end_trigger controls how often we stop parsing
6036 * NUL: parse all, execute, return
6037 * ';': parse till ';' or newline, execute, repeat till EOF
6039 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6041 /* Why we need empty flag?
6042 * An obscure corner case "false; ``; echo $?":
6043 * empty command in `` should still set $? to 0.
6044 * But we can't just set $? to 0 at the start,
6045 * this breaks "false; echo `echo $?`" case.
6049 struct pipe *pipe_list;
6051 #if ENABLE_HUSH_INTERACTIVE
6052 if (end_trigger == ';')
6053 inp->promptmode = 0; /* PS1 */
6055 pipe_list = parse_stream(NULL, inp, end_trigger);
6056 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6057 /* If we are in "big" script
6058 * (not in `cmd` or something similar)...
6060 if (pipe_list == ERR_PTR && end_trigger == ';') {
6061 /* Discard cached input (rest of line) */
6062 int ch = inp->last_char;
6063 while (ch != EOF && ch != '\n') {
6064 //bb_error_msg("Discarded:'%c'", ch);
6069 /* This stream isn't empty */
6073 if (!pipe_list && empty)
6074 G.last_exitcode = 0;
6077 debug_print_tree(pipe_list, 0);
6078 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6079 run_and_free_list(pipe_list);
6081 #if ENABLE_HUSH_FUNCTIONS
6082 if (G.flag_return_in_progress == 1)
6088 static void parse_and_run_string(const char *s)
6090 struct in_str input;
6091 setup_string_in_str(&input, s);
6092 parse_and_run_stream(&input, '\0');
6095 static void parse_and_run_file(FILE *f)
6097 struct in_str input;
6098 setup_file_in_str(&input, f);
6099 parse_and_run_stream(&input, ';');
6102 #if ENABLE_HUSH_TICK
6103 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6108 char **to_free = NULL;
6112 pid = BB_MMU ? xfork() : xvfork();
6113 if (pid == 0) { /* child */
6114 disable_restore_tty_pgrp_on_exit();
6115 /* Process substitution is not considered to be usual
6116 * 'command execution'.
6117 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6124 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6125 close(channel[0]); /* NB: close _first_, then move fd! */
6126 xmove_fd(channel[1], 1);
6127 /* Prevent it from trying to handle ctrl-z etc */
6128 IF_HUSH_JOB(G.run_list_level = 1;)
6129 /* Awful hack for `trap` or $(trap).
6131 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6132 * contains an example where "trap" is executed in a subshell:
6134 * save_traps=$(trap)
6136 * eval "$save_traps"
6138 * Standard does not say that "trap" in subshell shall print
6139 * parent shell's traps. It only says that its output
6140 * must have suitable form, but then, in the above example
6141 * (which is not supposed to be normative), it implies that.
6143 * bash (and probably other shell) does implement it
6144 * (traps are reset to defaults, but "trap" still shows them),
6145 * but as a result, "trap" logic is hopelessly messed up:
6148 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6149 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6150 * # true | trap <--- trap is in subshell - no output (ditto)
6151 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6152 * trap -- 'echo Ho' SIGWINCH
6153 * # echo `(trap)` <--- in subshell in subshell - output
6154 * trap -- 'echo Ho' SIGWINCH
6155 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6156 * trap -- 'echo Ho' SIGWINCH
6158 * The rules when to forget and when to not forget traps
6159 * get really complex and nonsensical.
6161 * Our solution: ONLY bare $(trap) or `trap` is special.
6163 s = skip_whitespace(s);
6164 if (is_prefixed_with(s, "trap")
6165 && skip_whitespace(s + 4)[0] == '\0'
6167 static const char *const argv[] = { NULL, NULL };
6168 builtin_trap((char**)argv);
6169 fflush_all(); /* important */
6173 reset_traps_to_defaults();
6174 parse_and_run_string(s);
6175 _exit(G.last_exitcode);
6177 /* We re-execute after vfork on NOMMU. This makes this script safe:
6178 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6179 * huge=`cat BIG` # was blocking here forever
6182 re_execute_shell(&to_free,
6192 # if ENABLE_HUSH_FAST
6194 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6195 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6196 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6198 enable_restore_tty_pgrp_on_exit();
6203 return remember_FILE(xfdopen_for_read(channel[0]));
6206 /* Return code is exit status of the process that is run. */
6207 static int process_command_subs(o_string *dest, const char *s)
6210 struct in_str pipe_str;
6212 int status, ch, eol_cnt;
6214 fp = generate_stream_from_string(s, &pid);
6216 /* Now send results of command back into original context */
6217 setup_file_in_str(&pipe_str, fp);
6219 while ((ch = i_getch(&pipe_str)) != EOF) {
6225 o_addchr(dest, '\n');
6228 o_addQchr(dest, ch);
6231 debug_printf("done reading from `cmd` pipe, closing it\n");
6232 fclose_and_forget(fp);
6233 /* We need to extract exitcode. Test case
6234 * "true; echo `sleep 1; false` $?"
6236 safe_waitpid(pid, &status, 0);
6237 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6238 return WEXITSTATUS(status);
6240 #endif /* ENABLE_HUSH_TICK */
6243 static void setup_heredoc(struct redir_struct *redir)
6245 struct fd_pair pair;
6248 /* the _body_ of heredoc (misleading field name) */
6249 const char *heredoc = redir->rd_filename;
6256 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6257 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6261 len = strlen(heredoc);
6263 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6265 xmove_fd(pair.rd, redir->rd_fd);
6267 /* Try writing without forking. Newer kernels have
6268 * dynamically growing pipes. Must use non-blocking write! */
6271 written = write(pair.wr, heredoc, len);
6282 ndelay_off(pair.wr);
6284 /* Okay, pipe buffer was not big enough */
6285 /* Note: we must not create a stray child (bastard? :)
6286 * for the unsuspecting parent process. Child creates a grandchild
6287 * and exits before parent execs the process which consumes heredoc
6288 * (that exec happens after we return from this function) */
6295 disable_restore_tty_pgrp_on_exit();
6296 pid = BB_MMU ? xfork() : xvfork();
6300 close(redir->rd_fd); /* read side of the pipe */
6302 full_write(pair.wr, heredoc, len); /* may loop or block */
6305 /* Delegate blocking writes to another process */
6306 xmove_fd(pair.wr, STDOUT_FILENO);
6307 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6311 #if ENABLE_HUSH_FAST
6313 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6315 enable_restore_tty_pgrp_on_exit();
6321 wait(NULL); /* wait till child has died */
6324 /* fd: redirect wants this fd to be used (e.g. 3>file).
6325 * Move all conflicting internally used fds,
6326 * and remember them so that we can restore them later.
6328 static int save_fds_on_redirect(int fd, int squirrel[3])
6331 /* Handle redirects of fds 0,1,2 */
6333 /* If we collide with an already moved stdio fd... */
6334 if (fd == squirrel[0]) {
6335 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6338 if (fd == squirrel[1]) {
6339 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6342 if (fd == squirrel[2]) {
6343 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6346 /* If we are about to redirect stdio fd, and did not yet move it... */
6347 if (fd <= 2 && squirrel[fd] < 0) {
6348 /* We avoid taking stdio fds */
6349 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6350 if (squirrel[fd] < 0 && errno != EBADF)
6352 return 0; /* "we did not close fd" */
6356 #if ENABLE_HUSH_INTERACTIVE
6357 if (fd != 0 && fd == G.interactive_fd) {
6358 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6363 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6364 * (1) Redirect in a forked child. No need to save FILEs' fds,
6365 * we aren't going to use them anymore, ok to trash.
6366 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6367 * but how are we doing to use them?
6368 * "fileno(fd) = new_fd" can't be done.
6373 return save_FILEs_on_redirect(fd);
6376 static void restore_redirects(int squirrel[3])
6379 for (i = 0; i <= 2; i++) {
6382 /* We simply die on error */
6387 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6389 restore_redirected_FILEs();
6392 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6393 * and stderr if they are redirected. */
6394 static int setup_redirects(struct command *prog, int squirrel[])
6397 struct redir_struct *redir;
6399 for (redir = prog->redirects; redir; redir = redir->next) {
6400 if (redir->rd_type == REDIRECT_HEREDOC2) {
6401 /* "rd_fd<<HERE" case */
6402 save_fds_on_redirect(redir->rd_fd, squirrel);
6403 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6405 debug_printf_parse("set heredoc '%s'\n",
6406 redir->rd_filename);
6407 setup_heredoc(redir);
6411 if (redir->rd_dup == REDIRFD_TO_FILE) {
6412 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6414 if (redir->rd_filename == NULL) {
6417 * "cmd >" (no filename)
6418 * "cmd > <file" (2nd redirect starts too early)
6420 die_if_script("syntax error: %s", "invalid redirect");
6423 mode = redir_table[redir->rd_type].mode;
6424 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6425 openfd = open_or_warn(p, mode);
6428 /* Error message from open_or_warn can be lost
6429 * if stderr has been redirected, but bash
6430 * and ash both lose it as well
6431 * (though zsh doesn't!)
6436 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6437 openfd = redir->rd_dup;
6440 if (openfd != redir->rd_fd) {
6441 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6442 if (openfd == REDIRFD_CLOSE) {
6443 /* "rd_fd >&-" means "close me" */
6445 /* ^^^ optimization: saving may already
6446 * have closed it. If not... */
6447 close(redir->rd_fd);
6450 xdup2(openfd, redir->rd_fd);
6451 if (redir->rd_dup == REDIRFD_TO_FILE)
6452 /* "rd_fd > FILE" */
6454 /* else: "rd_fd > rd_dup" */
6461 static char *find_in_path(const char *arg)
6464 const char *PATH = get_local_var_value("PATH");
6470 const char *end = strchrnul(PATH, ':');
6471 int sz = end - PATH; /* must be int! */
6475 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6477 /* We have xxx::yyyy in $PATH,
6478 * it means "use current dir" */
6481 if (access(ret, F_OK) == 0)
6494 static const struct built_in_command *find_builtin_helper(const char *name,
6495 const struct built_in_command *x,
6496 const struct built_in_command *end)
6499 if (strcmp(name, x->b_cmd) != 0) {
6503 debug_printf_exec("found builtin '%s'\n", name);
6508 static const struct built_in_command *find_builtin1(const char *name)
6510 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6512 static const struct built_in_command *find_builtin(const char *name)
6514 const struct built_in_command *x = find_builtin1(name);
6517 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6520 #if ENABLE_HUSH_FUNCTIONS
6521 static struct function **find_function_slot(const char *name)
6523 struct function **funcpp = &G.top_func;
6525 if (strcmp(name, (*funcpp)->name) == 0) {
6528 funcpp = &(*funcpp)->next;
6533 static const struct function *find_function(const char *name)
6535 const struct function *funcp = *find_function_slot(name);
6537 debug_printf_exec("found function '%s'\n", name);
6541 /* Note: takes ownership on name ptr */
6542 static struct function *new_function(char *name)
6544 struct function **funcpp = find_function_slot(name);
6545 struct function *funcp = *funcpp;
6547 if (funcp != NULL) {
6548 struct command *cmd = funcp->parent_cmd;
6549 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6551 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6553 /* Note: if !funcp->body, do not free body_as_string!
6554 * This is a special case of "-F name body" function:
6555 * body_as_string was not malloced! */
6557 free_pipe_list(funcp->body);
6559 free(funcp->body_as_string);
6563 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6564 cmd->argv[0] = funcp->name;
6565 cmd->group = funcp->body;
6567 cmd->group_as_string = funcp->body_as_string;
6571 debug_printf_exec("remembering new function '%s'\n", name);
6572 funcp = *funcpp = xzalloc(sizeof(*funcp));
6573 /*funcp->next = NULL;*/
6580 static void unset_func(const char *name)
6582 struct function **funcpp = find_function_slot(name);
6583 struct function *funcp = *funcpp;
6585 if (funcp != NULL) {
6586 debug_printf_exec("freeing function '%s'\n", funcp->name);
6587 *funcpp = funcp->next;
6588 /* funcp is unlinked now, deleting it.
6589 * Note: if !funcp->body, the function was created by
6590 * "-F name body", do not free ->body_as_string
6591 * and ->name as they were not malloced. */
6593 free_pipe_list(funcp->body);
6596 free(funcp->body_as_string);
6604 #define exec_function(to_free, funcp, argv) \
6605 exec_function(funcp, argv)
6607 static void exec_function(char ***to_free,
6608 const struct function *funcp,
6609 char **argv) NORETURN;
6610 static void exec_function(char ***to_free,
6611 const struct function *funcp,
6617 argv[0] = G.global_argv[0];
6618 G.global_argv = argv;
6622 /* On MMU, funcp->body is always non-NULL */
6623 n = run_list(funcp->body);
6627 re_execute_shell(to_free,
6628 funcp->body_as_string,
6635 static int run_function(const struct function *funcp, char **argv)
6641 save_and_replace_G_args(&sv, argv);
6643 /* "we are in function, ok to use return" */
6644 sv_flg = G.flag_return_in_progress;
6645 G.flag_return_in_progress = -1;
6646 # if ENABLE_HUSH_LOCAL
6647 G.func_nest_level++;
6650 /* On MMU, funcp->body is always non-NULL */
6653 /* Function defined by -F */
6654 parse_and_run_string(funcp->body_as_string);
6655 rc = G.last_exitcode;
6659 rc = run_list(funcp->body);
6662 # if ENABLE_HUSH_LOCAL
6664 struct variable *var;
6665 struct variable **var_pp;
6667 var_pp = &G.top_var;
6668 while ((var = *var_pp) != NULL) {
6669 if (var->func_nest_level < G.func_nest_level) {
6670 var_pp = &var->next;
6674 if (var->flg_export)
6675 bb_unsetenv(var->varstr);
6676 /* Remove from global list */
6677 *var_pp = var->next;
6683 G.func_nest_level--;
6686 G.flag_return_in_progress = sv_flg;
6688 restore_G_args(&sv, argv);
6692 #endif /* ENABLE_HUSH_FUNCTIONS */
6696 #define exec_builtin(to_free, x, argv) \
6697 exec_builtin(x, argv)
6699 #define exec_builtin(to_free, x, argv) \
6700 exec_builtin(to_free, argv)
6702 static void exec_builtin(char ***to_free,
6703 const struct built_in_command *x,
6704 char **argv) NORETURN;
6705 static void exec_builtin(char ***to_free,
6706 const struct built_in_command *x,
6712 rcode = x->b_function(argv);
6717 /* On NOMMU, we must never block!
6718 * Example: { sleep 99 | read line; } & echo Ok
6720 re_execute_shell(to_free,
6729 static void execvp_or_die(char **argv) NORETURN;
6730 static void execvp_or_die(char **argv)
6732 debug_printf_exec("execing '%s'\n", argv[0]);
6733 /* Don't propagate SIG_IGN to the child */
6734 if (SPECIAL_JOBSTOP_SIGS != 0)
6735 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6736 execvp(argv[0], argv);
6737 bb_perror_msg("can't execute '%s'", argv[0]);
6738 _exit(127); /* bash compat */
6741 #if ENABLE_HUSH_MODE_X
6742 static void dump_cmd_in_x_mode(char **argv)
6744 if (G_x_mode && argv) {
6745 /* We want to output the line in one write op */
6753 len += strlen(argv[n++]) + 1;
6759 p += sprintf(p, " %s", argv[n++]);
6767 # define dump_cmd_in_x_mode(argv) ((void)0)
6771 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6772 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6773 #define pseudo_exec(nommu_save, command, argv_expanded) \
6774 pseudo_exec(command, argv_expanded)
6777 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6779 * Don't exit() here. If you don't exec, use _exit instead.
6780 * The at_exit handlers apparently confuse the calling process,
6781 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6783 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6784 char **argv, int assignment_cnt,
6785 char **argv_expanded) NORETURN;
6786 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6787 char **argv, int assignment_cnt,
6788 char **argv_expanded)
6792 new_env = expand_assignments(argv, assignment_cnt);
6793 dump_cmd_in_x_mode(new_env);
6795 if (!argv[assignment_cnt]) {
6796 /* Case when we are here: ... | var=val | ...
6797 * (note that we do not exit early, i.e., do not optimize out
6798 * expand_assignments(): think about ... | var=`sleep 1` | ...
6800 free_strings(new_env);
6801 _exit(EXIT_SUCCESS);
6805 set_vars_and_save_old(new_env);
6806 free(new_env); /* optional */
6807 /* we can also destroy set_vars_and_save_old's return value,
6810 nommu_save->new_env = new_env;
6811 nommu_save->old_vars = set_vars_and_save_old(new_env);
6814 if (argv_expanded) {
6815 argv = argv_expanded;
6817 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6819 nommu_save->argv = argv;
6822 dump_cmd_in_x_mode(argv);
6824 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6825 if (strchr(argv[0], '/') != NULL)
6829 /* Check if the command matches any of the builtins.
6830 * Depending on context, this might be redundant. But it's
6831 * easier to waste a few CPU cycles than it is to figure out
6832 * if this is one of those cases.
6835 /* On NOMMU, it is more expensive to re-execute shell
6836 * just in order to run echo or test builtin.
6837 * It's better to skip it here and run corresponding
6838 * non-builtin later. */
6839 const struct built_in_command *x;
6840 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6842 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6845 #if ENABLE_HUSH_FUNCTIONS
6846 /* Check if the command matches any functions */
6848 const struct function *funcp = find_function(argv[0]);
6850 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6855 #if ENABLE_FEATURE_SH_STANDALONE
6856 /* Check if the command matches any busybox applets */
6858 int a = find_applet_by_name(argv[0]);
6860 # if BB_MMU /* see above why on NOMMU it is not allowed */
6861 if (APPLET_IS_NOEXEC(a)) {
6862 /* Do not leak open fds from opened script files etc */
6863 close_all_FILE_list();
6864 debug_printf_exec("running applet '%s'\n", argv[0]);
6865 run_applet_no_and_exit(a, argv);
6868 /* Re-exec ourselves */
6869 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6870 /* Don't propagate SIG_IGN to the child */
6871 if (SPECIAL_JOBSTOP_SIGS != 0)
6872 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6873 execv(bb_busybox_exec_path, argv);
6874 /* If they called chroot or otherwise made the binary no longer
6875 * executable, fall through */
6880 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6883 execvp_or_die(argv);
6886 /* Called after [v]fork() in run_pipe
6888 static void pseudo_exec(nommu_save_t *nommu_save,
6889 struct command *command,
6890 char **argv_expanded) NORETURN;
6891 static void pseudo_exec(nommu_save_t *nommu_save,
6892 struct command *command,
6893 char **argv_expanded)
6895 if (command->argv) {
6896 pseudo_exec_argv(nommu_save, command->argv,
6897 command->assignment_cnt, argv_expanded);
6900 if (command->group) {
6901 /* Cases when we are here:
6904 * ... | ( list ) | ...
6905 * ... | { list } | ...
6909 debug_printf_exec("pseudo_exec: run_list\n");
6910 reset_traps_to_defaults();
6911 rcode = run_list(command->group);
6912 /* OK to leak memory by not calling free_pipe_list,
6913 * since this process is about to exit */
6916 re_execute_shell(&nommu_save->argv_from_re_execing,
6917 command->group_as_string,
6924 /* Case when we are here: ... | >file */
6925 debug_printf_exec("pseudo_exec'ed null command\n");
6926 _exit(EXIT_SUCCESS);
6930 static const char *get_cmdtext(struct pipe *pi)
6936 /* This is subtle. ->cmdtext is created only on first backgrounding.
6937 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6938 * On subsequent bg argv is trashed, but we won't use it */
6941 argv = pi->cmds[0].argv;
6942 if (!argv || !argv[0]) {
6943 pi->cmdtext = xzalloc(1);
6949 len += strlen(*argv) + 1;
6953 argv = pi->cmds[0].argv;
6955 len = strlen(*argv);
6956 memcpy(p, *argv, len);
6964 static void insert_bg_job(struct pipe *pi)
6966 struct pipe *job, **jobp;
6969 /* Linear search for the ID of the job to use */
6971 for (job = G.job_list; job; job = job->next)
6972 if (job->jobid >= pi->jobid)
6973 pi->jobid = job->jobid + 1;
6975 /* Add job to the list of running jobs */
6977 while ((job = *jobp) != NULL)
6979 job = *jobp = xmalloc(sizeof(*job));
6981 *job = *pi; /* physical copy */
6983 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6984 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6985 for (i = 0; i < pi->num_cmds; i++) {
6986 job->cmds[i].pid = pi->cmds[i].pid;
6987 /* all other fields are not used and stay zero */
6989 job->cmdtext = xstrdup(get_cmdtext(pi));
6991 if (G_interactive_fd)
6992 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6993 G.last_jobid = job->jobid;
6996 static void remove_bg_job(struct pipe *pi)
6998 struct pipe *prev_pipe;
7000 if (pi == G.job_list) {
7001 G.job_list = pi->next;
7003 prev_pipe = G.job_list;
7004 while (prev_pipe->next != pi)
7005 prev_pipe = prev_pipe->next;
7006 prev_pipe->next = pi->next;
7009 G.last_jobid = G.job_list->jobid;
7014 /* Remove a backgrounded job */
7015 static void delete_finished_bg_job(struct pipe *pi)
7022 /* Check to see if any processes have exited -- if they
7023 * have, figure out why and see if a job has completed */
7024 static int checkjobs(struct pipe *fg_pipe)
7034 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7036 attributes = WUNTRACED;
7037 if (fg_pipe == NULL)
7038 attributes |= WNOHANG;
7041 #if ENABLE_HUSH_FAST
7042 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7043 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7044 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7045 /* There was neither fork nor SIGCHLD since last waitpid */
7046 /* Avoid doing waitpid syscall if possible */
7047 if (!G.we_have_children) {
7051 if (fg_pipe == NULL) { /* is WNOHANG set? */
7052 /* We have children, but they did not exit
7053 * or stop yet (we saw no SIGCHLD) */
7056 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7060 /* Do we do this right?
7061 * bash-3.00# sleep 20 | false
7063 * [3]+ Stopped sleep 20 | false
7064 * bash-3.00# echo $?
7065 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7066 * [hush 1.14.0: yes we do it right]
7073 #if ENABLE_HUSH_FAST
7074 i = G.count_SIGCHLD;
7076 childpid = waitpid(-1, &status, attributes);
7077 if (childpid <= 0) {
7078 if (childpid && errno != ECHILD)
7079 bb_perror_msg("waitpid");
7080 #if ENABLE_HUSH_FAST
7081 else { /* Until next SIGCHLD, waitpid's are useless */
7082 G.we_have_children = (childpid == 0);
7083 G.handled_SIGCHLD = i;
7084 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7089 dead = WIFEXITED(status) || WIFSIGNALED(status);
7092 if (WIFSTOPPED(status))
7093 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7094 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7095 if (WIFSIGNALED(status))
7096 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7097 childpid, WTERMSIG(status), WEXITSTATUS(status));
7098 if (WIFEXITED(status))
7099 debug_printf_jobs("pid %d exited, exitcode %d\n",
7100 childpid, WEXITSTATUS(status));
7102 /* Were we asked to wait for fg pipe? */
7104 i = fg_pipe->num_cmds;
7106 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7107 if (fg_pipe->cmds[i].pid != childpid)
7111 fg_pipe->cmds[i].pid = 0;
7112 fg_pipe->alive_cmds--;
7113 ex = WEXITSTATUS(status);
7114 /* bash prints killer signal's name for *last*
7115 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7116 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7118 if (WIFSIGNALED(status)) {
7119 int sig = WTERMSIG(status);
7120 if (i == fg_pipe->num_cmds-1)
7121 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7122 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7123 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7124 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7125 * Maybe we need to use sig | 128? */
7128 fg_pipe->cmds[i].cmd_exitcode = ex;
7130 fg_pipe->stopped_cmds++;
7132 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7133 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7134 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
7135 /* All processes in fg pipe have exited or stopped */
7136 i = fg_pipe->num_cmds;
7138 rcode = fg_pipe->cmds[i].cmd_exitcode;
7139 /* usually last process gives overall exitstatus,
7140 * but with "set -o pipefail", last *failed* process does */
7141 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7144 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
7145 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7146 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7147 * and "killall -STOP cat" */
7148 if (G_interactive_fd) {
7150 if (fg_pipe->alive_cmds != 0)
7151 insert_bg_job(fg_pipe);
7155 if (fg_pipe->alive_cmds == 0)
7158 /* There are still running processes in the fg pipe */
7159 goto wait_more; /* do waitpid again */
7161 /* it wasnt fg_pipe, look for process in bg pipes */
7165 /* We asked to wait for bg or orphaned children */
7166 /* No need to remember exitcode in this case */
7167 for (pi = G.job_list; pi; pi = pi->next) {
7168 for (i = 0; i < pi->num_cmds; i++) {
7169 if (pi->cmds[i].pid == childpid)
7170 goto found_pi_and_prognum;
7173 /* Happens when shell is used as init process (init=/bin/sh) */
7174 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7175 continue; /* do waitpid again */
7177 found_pi_and_prognum:
7180 pi->cmds[i].pid = 0;
7182 if (!pi->alive_cmds) {
7183 if (G_interactive_fd)
7184 printf(JOB_STATUS_FORMAT, pi->jobid,
7185 "Done", pi->cmdtext);
7186 delete_finished_bg_job(pi);
7193 } /* while (waitpid succeeds)... */
7199 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7202 int rcode = checkjobs(fg_pipe);
7203 if (G_saved_tty_pgrp) {
7204 /* Job finished, move the shell to the foreground */
7205 p = getpgrp(); /* our process group id */
7206 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7207 tcsetpgrp(G_interactive_fd, p);
7213 /* Start all the jobs, but don't wait for anything to finish.
7216 * Return code is normally -1, when the caller has to wait for children
7217 * to finish to determine the exit status of the pipe. If the pipe
7218 * is a simple builtin command, however, the action is done by the
7219 * time run_pipe returns, and the exit code is provided as the
7222 * Returns -1 only if started some children. IOW: we have to
7223 * mask out retvals of builtins etc with 0xff!
7225 * The only case when we do not need to [v]fork is when the pipe
7226 * is single, non-backgrounded, non-subshell command. Examples:
7227 * cmd ; ... { list } ; ...
7228 * cmd && ... { list } && ...
7229 * cmd || ... { list } || ...
7230 * If it is, then we can run cmd as a builtin, NOFORK,
7231 * or (if SH_STANDALONE) an applet, and we can run the { list }
7232 * with run_list. If it isn't one of these, we fork and exec cmd.
7234 * Cases when we must fork:
7235 * non-single: cmd | cmd
7236 * backgrounded: cmd & { list } &
7237 * subshell: ( list ) [&]
7239 #if !ENABLE_HUSH_MODE_X
7240 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7241 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7243 static int redirect_and_varexp_helper(char ***new_env_p,
7244 struct variable **old_vars_p,
7245 struct command *command,
7247 char **argv_expanded)
7249 /* setup_redirects acts on file descriptors, not FILEs.
7250 * This is perfect for work that comes after exec().
7251 * Is it really safe for inline use? Experimentally,
7252 * things seem to work. */
7253 int rcode = setup_redirects(command, squirrel);
7255 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7256 *new_env_p = new_env;
7257 dump_cmd_in_x_mode(new_env);
7258 dump_cmd_in_x_mode(argv_expanded);
7260 *old_vars_p = set_vars_and_save_old(new_env);
7264 static NOINLINE int run_pipe(struct pipe *pi)
7266 static const char *const null_ptr = NULL;
7270 struct command *command;
7271 char **argv_expanded;
7273 /* it is not always needed, but we aim to smaller code */
7274 int squirrel[] = { -1, -1, -1 };
7277 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7280 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7281 * Result should be 3 lines: q w e, qwe, q w e
7283 G.ifs = get_local_var_value("IFS");
7287 IF_HUSH_JOB(pi->pgrp = -1;)
7288 pi->stopped_cmds = 0;
7289 command = &pi->cmds[0];
7290 argv_expanded = NULL;
7292 if (pi->num_cmds != 1
7293 || pi->followup == PIPE_BG
7294 || command->cmd_type == CMD_SUBSHELL
7301 debug_printf_exec(": group:%p argv:'%s'\n",
7302 command->group, command->argv ? command->argv[0] : "NONE");
7304 if (command->group) {
7305 #if ENABLE_HUSH_FUNCTIONS
7306 if (command->cmd_type == CMD_FUNCDEF) {
7307 /* "executing" func () { list } */
7308 struct function *funcp;
7310 funcp = new_function(command->argv[0]);
7311 /* funcp->name is already set to argv[0] */
7312 funcp->body = command->group;
7314 funcp->body_as_string = command->group_as_string;
7315 command->group_as_string = NULL;
7317 command->group = NULL;
7318 command->argv[0] = NULL;
7319 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7320 funcp->parent_cmd = command;
7321 command->child_func = funcp;
7323 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7325 return EXIT_SUCCESS;
7329 debug_printf("non-subshell group\n");
7330 rcode = 1; /* exitcode if redir failed */
7331 if (setup_redirects(command, squirrel) == 0) {
7332 debug_printf_exec(": run_list\n");
7333 rcode = run_list(command->group) & 0xff;
7335 restore_redirects(squirrel);
7336 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7338 debug_printf_exec("run_pipe: return %d\n", rcode);
7342 argv = command->argv ? command->argv : (char **) &null_ptr;
7344 const struct built_in_command *x;
7345 #if ENABLE_HUSH_FUNCTIONS
7346 const struct function *funcp;
7350 char **new_env = NULL;
7351 struct variable *old_vars = NULL;
7353 if (argv[command->assignment_cnt] == NULL) {
7354 /* Assignments, but no command */
7355 /* Ensure redirects take effect (that is, create files).
7356 * Try "a=t >file" */
7357 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7358 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7359 /* Set shell variables */
7363 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7364 /* Do we need to flag set_local_var() errors?
7365 * "assignment to readonly var" and "putenv error"
7370 /* Redirect error sets $? to 1. Otherwise,
7371 * if evaluating assignment value set $?, retain it.
7372 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7374 rcode = G.last_exitcode;
7375 /* Exit, _skipping_ variable restoring code: */
7376 goto clean_up_and_ret0;
7378 #else /* Older, bigger, but more correct code */
7380 rcode = setup_redirects(command, squirrel);
7381 restore_redirects(squirrel);
7382 /* Set shell variables */
7384 bb_putchar_stderr('+');
7386 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7388 fprintf(stderr, " %s", p);
7389 debug_printf_exec("set shell var:'%s'->'%s'\n",
7391 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7392 /* Do we need to flag set_local_var() errors?
7393 * "assignment to readonly var" and "putenv error"
7398 bb_putchar_stderr('\n');
7399 /* Redirect error sets $? to 1. Otherwise,
7400 * if evaluating assignment value set $?, retain it.
7401 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7403 rcode = G.last_exitcode;
7404 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7406 debug_printf_exec("run_pipe: return %d\n", rcode);
7411 /* Expand the rest into (possibly) many strings each */
7412 #if ENABLE_HUSH_BASH_COMPAT
7413 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7414 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7418 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7421 /* if someone gives us an empty string: `cmd with empty output` */
7422 if (!argv_expanded[0]) {
7423 free(argv_expanded);
7425 return G.last_exitcode;
7428 x = find_builtin(argv_expanded[0]);
7429 #if ENABLE_HUSH_FUNCTIONS
7432 funcp = find_function(argv_expanded[0]);
7436 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7437 debug_printf("exec with redirects only\n");
7438 rcode = setup_redirects(command, NULL);
7439 /* rcode=1 can be if redir file can't be opened */
7440 goto clean_up_and_ret1;
7443 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7446 debug_printf_exec(": builtin '%s' '%s'...\n",
7447 x->b_cmd, argv_expanded[1]);
7449 rcode = x->b_function(argv_expanded) & 0xff;
7452 #if ENABLE_HUSH_FUNCTIONS
7454 # if ENABLE_HUSH_LOCAL
7455 struct variable **sv;
7456 sv = G.shadowed_vars_pp;
7457 G.shadowed_vars_pp = &old_vars;
7459 debug_printf_exec(": function '%s' '%s'...\n",
7460 funcp->name, argv_expanded[1]);
7461 rcode = run_function(funcp, argv_expanded) & 0xff;
7462 # if ENABLE_HUSH_LOCAL
7463 G.shadowed_vars_pp = sv;
7469 unset_vars(new_env);
7471 /* clean_up_and_ret0: */
7472 restore_redirects(squirrel);
7474 free(argv_expanded);
7475 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7477 debug_printf_exec("run_pipe return %d\n", rcode);
7481 if (ENABLE_FEATURE_SH_NOFORK) {
7482 int n = find_applet_by_name(argv_expanded[0]);
7483 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7484 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7486 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7487 argv_expanded[0], argv_expanded[1]);
7488 rcode = run_nofork_applet(n, argv_expanded);
7490 goto clean_up_and_ret;
7493 /* It is neither builtin nor applet. We must fork. */
7497 /* NB: argv_expanded may already be created, and that
7498 * might include `cmd` runs! Do not rerun it! We *must*
7499 * use argv_expanded if it's non-NULL */
7501 /* Going to fork a child per each pipe member */
7506 while (cmd_no < pi->num_cmds) {
7507 struct fd_pair pipefds;
7509 volatile nommu_save_t nommu_save;
7510 nommu_save.new_env = NULL;
7511 nommu_save.old_vars = NULL;
7512 nommu_save.argv = NULL;
7513 nommu_save.argv_from_re_execing = NULL;
7515 command = &pi->cmds[cmd_no];
7517 if (command->argv) {
7518 debug_printf_exec(": pipe member '%s' '%s'...\n",
7519 command->argv[0], command->argv[1]);
7521 debug_printf_exec(": pipe member with no argv\n");
7524 /* pipes are inserted between pairs of commands */
7527 if (cmd_no < pi->num_cmds)
7528 xpiped_pair(pipefds);
7530 command->pid = BB_MMU ? fork() : vfork();
7531 if (!command->pid) { /* child */
7533 disable_restore_tty_pgrp_on_exit();
7534 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7536 /* Every child adds itself to new process group
7537 * with pgid == pid_of_first_child_in_pipe */
7538 if (G.run_list_level == 1 && G_interactive_fd) {
7541 if (pgrp < 0) /* true for 1st process only */
7543 if (setpgid(0, pgrp) == 0
7544 && pi->followup != PIPE_BG
7545 && G_saved_tty_pgrp /* we have ctty */
7547 /* We do it in *every* child, not just first,
7549 tcsetpgrp(G_interactive_fd, pgrp);
7553 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7554 /* 1st cmd in backgrounded pipe
7555 * should have its stdin /dev/null'ed */
7557 if (open(bb_dev_null, O_RDONLY))
7558 xopen("/", O_RDONLY);
7560 xmove_fd(next_infd, 0);
7562 xmove_fd(pipefds.wr, 1);
7565 /* Like bash, explicit redirects override pipes,
7566 * and the pipe fd (fd#1) is available for dup'ing:
7567 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7568 * of cmd1 goes into pipe.
7570 if (setup_redirects(command, NULL)) {
7571 /* Happens when redir file can't be opened:
7572 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7574 * hush: can't open '/qwe/rty': No such file or directory
7576 * (echo BAR is not executed, it hits _exit(1) below)
7581 /* Stores to nommu_save list of env vars putenv'ed
7582 * (NOMMU, on MMU we don't need that) */
7583 /* cast away volatility... */
7584 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7585 /* pseudo_exec() does not return */
7588 /* parent or error */
7589 #if ENABLE_HUSH_FAST
7591 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7593 enable_restore_tty_pgrp_on_exit();
7595 /* Clean up after vforked child */
7596 free(nommu_save.argv);
7597 free(nommu_save.argv_from_re_execing);
7598 unset_vars(nommu_save.new_env);
7599 add_vars(nommu_save.old_vars);
7601 free(argv_expanded);
7602 argv_expanded = NULL;
7603 if (command->pid < 0) { /* [v]fork failed */
7604 /* Clearly indicate, was it fork or vfork */
7605 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7609 /* Second and next children need to know pid of first one */
7611 pi->pgrp = command->pid;
7617 if (cmd_no < pi->num_cmds)
7619 /* Pass read (output) pipe end to next iteration */
7620 next_infd = pipefds.rd;
7623 if (!pi->alive_cmds) {
7625 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7630 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7634 /* NB: called by pseudo_exec, and therefore must not modify any
7635 * global data until exec/_exit (we can be a child after vfork!) */
7636 static int run_list(struct pipe *pi)
7638 #if ENABLE_HUSH_CASE
7639 char *case_word = NULL;
7641 #if ENABLE_HUSH_LOOPS
7642 struct pipe *loop_top = NULL;
7643 char **for_lcur = NULL;
7644 char **for_list = NULL;
7646 smallint last_followup;
7648 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7649 smalluint cond_code = 0;
7651 enum { cond_code = 0 };
7654 smallint rword; /* RES_foo */
7655 smallint last_rword; /* ditto */
7658 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7661 #if ENABLE_HUSH_LOOPS
7662 /* Check syntax for "for" */
7665 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7666 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7668 /* current word is FOR or IN (BOLD in comments below) */
7669 if (cpipe->next == NULL) {
7670 syntax_error("malformed for");
7672 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7675 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7676 if (cpipe->next->res_word == RES_DO)
7678 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7679 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7680 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7682 syntax_error("malformed for");
7684 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7691 /* Past this point, all code paths should jump to ret: label
7692 * in order to return, no direct "return" statements please.
7693 * This helps to ensure that no memory is leaked. */
7701 last_rword = RES_XXXX;
7703 last_followup = PIPE_SEQ;
7704 rcode = G.last_exitcode;
7706 /* Go through list of pipes, (maybe) executing them. */
7707 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7711 IF_HAS_KEYWORDS(rword = pi->res_word;)
7712 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7713 rword, cond_code, last_rword);
7714 #if ENABLE_HUSH_LOOPS
7715 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7716 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7718 /* start of a loop: remember where loop starts */
7723 /* Still in the same "if...", "then..." or "do..." branch? */
7724 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7725 if ((rcode == 0 && last_followup == PIPE_OR)
7726 || (rcode != 0 && last_followup == PIPE_AND)
7728 /* It is "<true> || CMD" or "<false> && CMD"
7729 * and we should not execute CMD */
7730 debug_printf_exec("skipped cmd because of || or &&\n");
7731 last_followup = pi->followup;
7732 goto dont_check_jobs_but_continue;
7735 last_followup = pi->followup;
7736 IF_HAS_KEYWORDS(last_rword = rword;)
7739 if (rword == RES_THEN) {
7740 /* if false; then ... fi has exitcode 0! */
7741 G.last_exitcode = rcode = EXIT_SUCCESS;
7742 /* "if <false> THEN cmd": skip cmd */
7746 if (rword == RES_ELSE || rword == RES_ELIF) {
7747 /* "if <true> then ... ELSE/ELIF cmd":
7748 * skip cmd and all following ones */
7753 #if ENABLE_HUSH_LOOPS
7754 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7756 /* first loop through for */
7758 static const char encoded_dollar_at[] ALIGN1 = {
7759 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7760 }; /* encoded representation of "$@" */
7761 static const char *const encoded_dollar_at_argv[] = {
7762 encoded_dollar_at, NULL
7763 }; /* argv list with one element: "$@" */
7766 vals = (char**)encoded_dollar_at_argv;
7767 if (pi->next->res_word == RES_IN) {
7768 /* if no variable values after "in" we skip "for" */
7769 if (!pi->next->cmds[0].argv) {
7770 G.last_exitcode = rcode = EXIT_SUCCESS;
7771 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7774 vals = pi->next->cmds[0].argv;
7775 } /* else: "for var; do..." -> assume "$@" list */
7776 /* create list of variable values */
7777 debug_print_strings("for_list made from", vals);
7778 for_list = expand_strvec_to_strvec(vals);
7779 for_lcur = for_list;
7780 debug_print_strings("for_list", for_list);
7783 /* "for" loop is over, clean up */
7789 /* Insert next value from for_lcur */
7790 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7791 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7794 if (rword == RES_IN) {
7795 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7797 if (rword == RES_DONE) {
7798 continue; /* "done" has no cmds too */
7801 #if ENABLE_HUSH_CASE
7802 if (rword == RES_CASE) {
7803 case_word = expand_strvec_to_string(pi->cmds->argv);
7806 if (rword == RES_MATCH) {
7809 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7811 /* all prev words didn't match, does this one match? */
7812 argv = pi->cmds->argv;
7814 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7815 /* TODO: which FNM_xxx flags to use? */
7816 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7818 if (cond_code == 0) { /* match! we will execute this branch */
7819 free(case_word); /* make future "word)" stop */
7827 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7829 continue; /* not matched yet, skip this pipe */
7832 /* Just pressing <enter> in shell should check for jobs.
7833 * OTOH, in non-interactive shell this is useless
7834 * and only leads to extra job checks */
7835 if (pi->num_cmds == 0) {
7836 if (G_interactive_fd)
7837 goto check_jobs_and_continue;
7841 /* After analyzing all keywords and conditions, we decided
7842 * to execute this pipe. NB: have to do checkjobs(NULL)
7843 * after run_pipe to collect any background children,
7844 * even if list execution is to be stopped. */
7845 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7848 #if ENABLE_HUSH_LOOPS
7849 G.flag_break_continue = 0;
7851 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7853 /* We ran a builtin, function, or group.
7854 * rcode is already known
7855 * and we don't need to wait for anything. */
7856 G.last_exitcode = rcode;
7857 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7858 check_and_run_traps();
7859 #if ENABLE_HUSH_LOOPS
7860 /* Was it "break" or "continue"? */
7861 if (G.flag_break_continue) {
7862 smallint fbc = G.flag_break_continue;
7863 /* We might fall into outer *loop*,
7864 * don't want to break it too */
7866 G.depth_break_continue--;
7867 if (G.depth_break_continue == 0)
7868 G.flag_break_continue = 0;
7869 /* else: e.g. "continue 2" should *break* once, *then* continue */
7870 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7871 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7875 /* "continue": simulate end of loop */
7880 #if ENABLE_HUSH_FUNCTIONS
7881 if (G.flag_return_in_progress == 1) {
7886 } else if (pi->followup == PIPE_BG) {
7887 /* What does bash do with attempts to background builtins? */
7888 /* even bash 3.2 doesn't do that well with nested bg:
7889 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7890 * I'm NOT treating inner &'s as jobs */
7891 check_and_run_traps();
7893 if (G.run_list_level == 1)
7896 /* Last command's pid goes to $! */
7897 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7898 G.last_exitcode = rcode = EXIT_SUCCESS;
7899 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7902 if (G.run_list_level == 1 && G_interactive_fd) {
7903 /* Waits for completion, then fg's main shell */
7904 rcode = checkjobs_and_fg_shell(pi);
7905 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7906 check_and_run_traps();
7909 { /* This one just waits for completion */
7910 rcode = checkjobs(pi);
7911 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7912 check_and_run_traps();
7914 G.last_exitcode = rcode;
7918 /* Analyze how result affects subsequent commands */
7920 if (rword == RES_IF || rword == RES_ELIF)
7923 check_jobs_and_continue:
7925 dont_check_jobs_but_continue: ;
7926 #if ENABLE_HUSH_LOOPS
7927 /* Beware of "while false; true; do ..."! */
7929 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
7930 /* check for RES_DONE is needed for "while ...; do \n done" case */
7932 if (rword == RES_WHILE) {
7934 /* "while false; do...done" - exitcode 0 */
7935 G.last_exitcode = rcode = EXIT_SUCCESS;
7936 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7940 if (rword == RES_UNTIL) {
7942 debug_printf_exec(": until expr is true: breaking\n");
7953 #if ENABLE_HUSH_LOOPS
7958 #if ENABLE_HUSH_CASE
7962 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7966 /* Select which version we will use */
7967 static int run_and_free_list(struct pipe *pi)
7970 debug_printf_exec("run_and_free_list entered\n");
7971 if (!G.o_opt[OPT_O_NOEXEC]) {
7972 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7973 rcode = run_list(pi);
7975 /* free_pipe_list has the side effect of clearing memory.
7976 * In the long run that function can be merged with run_list,
7977 * but doing that now would hobble the debugging effort. */
7979 debug_printf_exec("run_and_free_list return %d\n", rcode);
7984 static void install_sighandlers(unsigned mask)
7986 sighandler_t old_handler;
7988 while ((mask >>= 1) != 0) {
7992 old_handler = install_sighandler(sig, pick_sighandler(sig));
7993 /* POSIX allows shell to re-enable SIGCHLD
7994 * even if it was SIG_IGN on entry.
7995 * Therefore we skip IGN check for it:
7999 if (old_handler == SIG_IGN) {
8000 /* oops... restore back to IGN, and record this fact */
8001 install_sighandler(sig, old_handler);
8003 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8005 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8010 /* Called a few times only (or even once if "sh -c") */
8011 static void install_special_sighandlers(void)
8015 /* Which signals are shell-special? */
8016 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8017 if (G_interactive_fd) {
8018 mask |= SPECIAL_INTERACTIVE_SIGS;
8019 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8020 mask |= SPECIAL_JOBSTOP_SIGS;
8022 /* Careful, do not re-install handlers we already installed */
8023 if (G.special_sig_mask != mask) {
8024 unsigned diff = mask & ~G.special_sig_mask;
8025 G.special_sig_mask = mask;
8026 install_sighandlers(diff);
8032 /* Set handlers to restore tty pgrp and exit */
8033 static void install_fatal_sighandlers(void)
8037 /* We will restore tty pgrp on these signals */
8039 + (1 << SIGILL ) * HUSH_DEBUG
8040 + (1 << SIGFPE ) * HUSH_DEBUG
8041 + (1 << SIGBUS ) * HUSH_DEBUG
8042 + (1 << SIGSEGV) * HUSH_DEBUG
8043 + (1 << SIGTRAP) * HUSH_DEBUG
8045 /* bash 3.2 seems to handle these just like 'fatal' ones */
8048 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8049 * if we aren't interactive... but in this case
8050 * we never want to restore pgrp on exit, and this fn is not called
8052 /*+ (1 << SIGHUP )*/
8053 /*+ (1 << SIGTERM)*/
8054 /*+ (1 << SIGINT )*/
8056 G_fatal_sig_mask = mask;
8058 install_sighandlers(mask);
8062 static int set_mode(int state, char mode, const char *o_opt)
8067 G.o_opt[OPT_O_NOEXEC] = state;
8070 IF_HUSH_MODE_X(G_x_mode = state;)
8074 /* "set -+o" without parameter.
8075 * in bash, set -o produces this output:
8079 * We always use the second form.
8081 const char *p = o_opt_strings;
8084 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8090 idx = index_in_strings(o_opt_strings, o_opt);
8092 G.o_opt[idx] = state;
8096 return EXIT_FAILURE;
8098 return EXIT_SUCCESS;
8101 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8102 int hush_main(int argc, char **argv)
8105 OPT_login = (1 << 0),
8109 unsigned builtin_argc;
8111 struct variable *cur_var;
8112 struct variable *shell_ver;
8115 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8116 G.last_exitcode = EXIT_SUCCESS;
8118 #if ENABLE_HUSH_FAST
8119 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8122 G.argv0_for_re_execing = argv[0];
8124 /* Deal with HUSH_VERSION */
8125 shell_ver = xzalloc(sizeof(*shell_ver));
8126 shell_ver->flg_export = 1;
8127 shell_ver->flg_read_only = 1;
8128 /* Code which handles ${var<op>...} needs writable values for all variables,
8129 * therefore we xstrdup: */
8130 shell_ver->varstr = xstrdup(hush_version_str);
8131 /* Create shell local variables from the values
8132 * currently living in the environment */
8133 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8134 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8135 G.top_var = shell_ver;
8136 cur_var = G.top_var;
8139 char *value = strchr(*e, '=');
8140 if (value) { /* paranoia */
8141 cur_var->next = xzalloc(sizeof(*cur_var));
8142 cur_var = cur_var->next;
8143 cur_var->varstr = *e;
8144 cur_var->max_len = strlen(*e);
8145 cur_var->flg_export = 1;
8149 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8150 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8151 putenv(shell_ver->varstr);
8154 set_pwd_var(/*exp:*/ 1);
8156 #if ENABLE_HUSH_BASH_COMPAT
8157 /* Set (but not export) HOSTNAME unless already set */
8158 if (!get_local_var_value("HOSTNAME")) {
8161 set_local_var_from_halves("HOSTNAME", uts.nodename);
8163 /* bash also exports SHLVL and _,
8164 * and sets (but doesn't export) the following variables:
8166 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8167 * BASH_VERSION='3.2.0(1)-release'
8169 * MACHTYPE=i386-pc-linux-gnu
8171 * PPID=<NNNNN> - we also do it elsewhere
8182 * PIPESTATUS=([0]="0")
8183 * HISTFILE=/<xxx>/.bash_history
8187 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8189 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8200 #if ENABLE_FEATURE_EDITING
8201 G.line_input_state = new_line_input_t(FOR_SHELL);
8204 /* Initialize some more globals to non-zero values */
8205 cmdedit_update_prompt();
8207 die_func = restore_ttypgrp_and__exit;
8209 /* Shell is non-interactive at first. We need to call
8210 * install_special_sighandlers() if we are going to execute "sh <script>",
8211 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8212 * If we later decide that we are interactive, we run install_special_sighandlers()
8213 * in order to intercept (more) signals.
8217 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8218 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8221 opt = getopt(argc, argv, "+c:xinsl"
8224 # if ENABLE_HUSH_FUNCTIONS
8234 * sh ... -c 'script'
8235 * sh ... -c 'script' ARG0 [ARG1...]
8236 * On NOMMU, if builtin_argc != 0,
8237 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8238 * "" needs to be replaced with NULL
8239 * and BARGV vector fed to builtin function.
8240 * Note: the form without ARG0 never happens:
8241 * sh ... -c 'builtin' BARGV... ""
8244 G.root_pid = getpid();
8245 G.root_ppid = getppid();
8247 G.global_argv = argv + optind;
8248 G.global_argc = argc - optind;
8250 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8251 const struct built_in_command *x;
8253 install_special_sighandlers();
8254 x = find_builtin(optarg);
8255 if (x) { /* paranoia */
8256 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8257 G.global_argv += builtin_argc;
8258 G.global_argv[-1] = NULL; /* replace "" */
8260 G.last_exitcode = x->b_function(argv + optind - 1);
8264 if (!G.global_argv[0]) {
8265 /* -c 'script' (no params): prevent empty $0 */
8266 G.global_argv--; /* points to argv[i] of 'script' */
8267 G.global_argv[0] = argv[0];
8269 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8270 install_special_sighandlers();
8271 parse_and_run_string(optarg);
8274 /* Well, we cannot just declare interactiveness,
8275 * we have to have some stuff (ctty, etc) */
8276 /* G_interactive_fd++; */
8279 /* "-s" means "read from stdin", but this is how we always
8280 * operate, so simply do nothing here. */
8286 case '<': /* "big heredoc" support */
8287 full_write1_str(optarg);
8290 unsigned long long empty_trap_mask;
8292 G.root_pid = bb_strtou(optarg, &optarg, 16);
8294 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8296 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8298 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8300 builtin_argc = bb_strtou(optarg, &optarg, 16);
8302 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8303 if (empty_trap_mask != 0) {
8305 install_special_sighandlers();
8306 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8307 for (sig = 1; sig < NSIG; sig++) {
8308 if (empty_trap_mask & (1LL << sig)) {
8309 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8310 install_sighandler(sig, SIG_IGN);
8314 # if ENABLE_HUSH_LOOPS
8316 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8322 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8324 # if ENABLE_HUSH_FUNCTIONS
8326 struct function *funcp = new_function(optarg);
8327 /* funcp->name is already set to optarg */
8328 /* funcp->body is set to NULL. It's a special case. */
8329 funcp->body_as_string = argv[optind];
8337 if (set_mode(1, opt, NULL) == 0) /* no error */
8341 fprintf(stderr, "Usage: sh [FILE]...\n"
8342 " or: sh -c command [args]...\n\n");
8348 } /* option parsing loop */
8350 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8351 G.global_argc = argc - (optind - 1);
8352 G.global_argv = argv + (optind - 1);
8353 G.global_argv[0] = argv[0];
8356 G.root_pid = getpid();
8357 G.root_ppid = getppid();
8360 /* If we are login shell... */
8361 if (flags & OPT_login) {
8363 debug_printf("sourcing /etc/profile\n");
8364 input = fopen_for_read("/etc/profile");
8365 if (input != NULL) {
8366 remember_FILE(input);
8367 install_special_sighandlers();
8368 parse_and_run_file(input);
8369 fclose_and_forget(input);
8371 /* bash: after sourcing /etc/profile,
8372 * tries to source (in the given order):
8373 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8374 * stopping on first found. --noprofile turns this off.
8375 * bash also sources ~/.bash_logout on exit.
8376 * If called as sh, skips .bash_XXX files.
8380 if (G.global_argv[1]) {
8383 * "bash <script>" (which is never interactive (unless -i?))
8384 * sources $BASH_ENV here (without scanning $PATH).
8385 * If called as sh, does the same but with $ENV.
8389 debug_printf("running script '%s'\n", G.global_argv[0]);
8390 input = xfopen_for_read(G.global_argv[0]);
8391 remember_FILE(input);
8392 install_special_sighandlers();
8393 parse_and_run_file(input);
8394 #if ENABLE_FEATURE_CLEAN_UP
8395 fclose_and_forget(input);
8400 /* Up to here, shell was non-interactive. Now it may become one.
8401 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8404 /* A shell is interactive if the '-i' flag was given,
8405 * or if all of the following conditions are met:
8407 * no arguments remaining or the -s flag given
8408 * standard input is a terminal
8409 * standard output is a terminal
8410 * Refer to Posix.2, the description of the 'sh' utility.
8413 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8414 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8415 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8416 if (G_saved_tty_pgrp < 0)
8417 G_saved_tty_pgrp = 0;
8419 /* try to dup stdin to high fd#, >= 255 */
8420 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8421 if (G_interactive_fd < 0) {
8422 /* try to dup to any fd */
8423 G_interactive_fd = dup(STDIN_FILENO);
8424 if (G_interactive_fd < 0) {
8426 G_interactive_fd = 0;
8427 G_saved_tty_pgrp = 0;
8430 // TODO: track & disallow any attempts of user
8431 // to (inadvertently) close/redirect G_interactive_fd
8433 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8434 if (G_interactive_fd) {
8435 close_on_exec_on(G_interactive_fd);
8437 if (G_saved_tty_pgrp) {
8438 /* If we were run as 'hush &', sleep until we are
8439 * in the foreground (tty pgrp == our pgrp).
8440 * If we get started under a job aware app (like bash),
8441 * make sure we are now in charge so we don't fight over
8442 * who gets the foreground */
8444 pid_t shell_pgrp = getpgrp();
8445 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8446 if (G_saved_tty_pgrp == shell_pgrp)
8448 /* send TTIN to ourself (should stop us) */
8449 kill(- shell_pgrp, SIGTTIN);
8453 /* Install more signal handlers */
8454 install_special_sighandlers();
8456 if (G_saved_tty_pgrp) {
8457 /* Set other signals to restore saved_tty_pgrp */
8458 install_fatal_sighandlers();
8459 /* Put ourselves in our own process group
8460 * (bash, too, does this only if ctty is available) */
8461 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8462 /* Grab control of the terminal */
8463 tcsetpgrp(G_interactive_fd, getpid());
8465 enable_restore_tty_pgrp_on_exit();
8467 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8469 const char *hp = get_local_var_value("HISTFILE");
8471 hp = get_local_var_value("HOME");
8473 hp = concat_path_file(hp, ".hush_history");
8478 G.line_input_state->hist_file = hp;
8479 //set_local_var(xasprintf("HISTFILE=%s", ...));
8481 # if ENABLE_FEATURE_SH_HISTFILESIZE
8482 hp = get_local_var_value("HISTFILESIZE");
8483 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8488 install_special_sighandlers();
8490 #elif ENABLE_HUSH_INTERACTIVE
8491 /* No job control compiled in, only prompt/line editing */
8492 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8493 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8494 if (G_interactive_fd < 0) {
8495 /* try to dup to any fd */
8496 G_interactive_fd = dup(STDIN_FILENO);
8497 if (G_interactive_fd < 0)
8499 G_interactive_fd = 0;
8502 if (G_interactive_fd) {
8503 close_on_exec_on(G_interactive_fd);
8505 install_special_sighandlers();
8507 /* We have interactiveness code disabled */
8508 install_special_sighandlers();
8511 * if interactive but not a login shell, sources ~/.bashrc
8512 * (--norc turns this off, --rcfile <file> overrides)
8515 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8516 /* note: ash and hush share this string */
8517 printf("\n\n%s %s\n"
8518 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8521 "hush - the humble shell"
8525 parse_and_run_file(stdin);
8528 hush_exit(G.last_exitcode);
8533 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8534 int msh_main(int argc, char **argv)
8536 bb_error_msg("msh is deprecated, please use hush instead");
8537 return hush_main(argc, argv);
8545 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8550 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8557 return applet_main_func(argc, argv - argc);
8560 static int FAST_FUNC builtin_test(char **argv)
8562 return run_applet_main(argv, test_main);
8565 static int FAST_FUNC builtin_echo(char **argv)
8567 return run_applet_main(argv, echo_main);
8571 static int FAST_FUNC builtin_printf(char **argv)
8573 return run_applet_main(argv, printf_main);
8577 static char **skip_dash_dash(char **argv)
8580 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8585 static int FAST_FUNC builtin_eval(char **argv)
8587 int rcode = EXIT_SUCCESS;
8589 argv = skip_dash_dash(argv);
8591 char *str = expand_strvec_to_string(argv);
8593 * eval "echo Hi; done" ("done" is syntax error):
8594 * "echo Hi" will not execute too.
8596 parse_and_run_string(str);
8598 rcode = G.last_exitcode;
8603 static int FAST_FUNC builtin_cd(char **argv)
8607 argv = skip_dash_dash(argv);
8609 if (newdir == NULL) {
8610 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8611 * bash says "bash: cd: HOME not set" and does nothing
8614 const char *home = get_local_var_value("HOME");
8615 newdir = home ? home : "/";
8617 if (chdir(newdir)) {
8618 /* Mimic bash message exactly */
8619 bb_perror_msg("cd: %s", newdir);
8620 return EXIT_FAILURE;
8622 /* Read current dir (get_cwd(1) is inside) and set PWD.
8623 * Note: do not enforce exporting. If PWD was unset or unexported,
8624 * set it again, but do not export. bash does the same.
8626 set_pwd_var(/*exp:*/ 0);
8627 return EXIT_SUCCESS;
8630 static int FAST_FUNC builtin_exec(char **argv)
8632 argv = skip_dash_dash(argv);
8633 if (argv[0] == NULL)
8634 return EXIT_SUCCESS; /* bash does this */
8636 /* Careful: we can end up here after [v]fork. Do not restore
8637 * tty pgrp then, only top-level shell process does that */
8638 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8639 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8641 /* TODO: if exec fails, bash does NOT exit! We do.
8642 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8643 * and tcsetpgrp, and this is inherently racy.
8645 execvp_or_die(argv);
8648 static int FAST_FUNC builtin_exit(char **argv)
8650 debug_printf_exec("%s()\n", __func__);
8652 /* interactive bash:
8653 * # trap "echo EEE" EXIT
8656 * There are stopped jobs.
8657 * (if there are _stopped_ jobs, running ones don't count)
8660 * EEE (then bash exits)
8662 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8665 /* note: EXIT trap is run by hush_exit */
8666 argv = skip_dash_dash(argv);
8667 if (argv[0] == NULL)
8668 hush_exit(G.last_exitcode);
8669 /* mimic bash: exit 123abc == exit 255 + error msg */
8670 xfunc_error_retval = 255;
8671 /* bash: exit -2 == exit 254, no error msg */
8672 hush_exit(xatoi(argv[0]) & 0xff);
8675 static void print_escaped(const char *s)
8680 const char *p = strchrnul(s, '\'');
8681 /* print 'xxxx', possibly just '' */
8682 printf("'%.*s'", (int)(p - s), s);
8687 /* s points to '; print "'''...'''" */
8689 do putchar('\''); while (*++s == '\'');
8694 #if !ENABLE_HUSH_LOCAL
8695 #define helper_export_local(argv, exp, lvl) \
8696 helper_export_local(argv, exp)
8698 static void helper_export_local(char **argv, int exp, int lvl)
8702 char *name_end = strchrnul(name, '=');
8704 /* So far we do not check that name is valid (TODO?) */
8706 if (*name_end == '\0') {
8707 struct variable *var, **vpp;
8709 vpp = get_ptr_to_local_var(name, name_end - name);
8710 var = vpp ? *vpp : NULL;
8712 if (exp == -1) { /* unexporting? */
8713 /* export -n NAME (without =VALUE) */
8715 var->flg_export = 0;
8716 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8718 } /* else: export -n NOT_EXISTING_VAR: no-op */
8721 if (exp == 1) { /* exporting? */
8722 /* export NAME (without =VALUE) */
8724 var->flg_export = 1;
8725 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8726 putenv(var->varstr);
8730 /* Exporting non-existing variable.
8731 * bash does not put it in environment,
8732 * but remembers that it is exported,
8733 * and does put it in env when it is set later.
8734 * We just set it to "" and export. */
8735 /* Or, it's "local NAME" (without =VALUE).
8736 * bash sets the value to "". */
8737 name = xasprintf("%s=", name);
8739 /* (Un)exporting/making local NAME=VALUE */
8740 name = xstrdup(name);
8742 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8746 static int FAST_FUNC builtin_export(char **argv)
8748 unsigned opt_unexport;
8750 #if ENABLE_HUSH_EXPORT_N
8751 /* "!": do not abort on errors */
8752 opt_unexport = getopt32(argv, "!n");
8753 if (opt_unexport == (uint32_t)-1)
8754 return EXIT_FAILURE;
8761 if (argv[0] == NULL) {
8768 /* ash emits: export VAR='VAL'
8769 * bash: declare -x VAR="VAL"
8770 * we follow ash example */
8771 const char *s = *e++;
8772 const char *p = strchr(s, '=');
8774 if (!p) /* wtf? take next variable */
8777 printf("export %.*s", (int)(p - s) + 1, s);
8778 print_escaped(p + 1);
8782 /*fflush_all(); - done after each builtin anyway */
8784 return EXIT_SUCCESS;
8787 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8789 return EXIT_SUCCESS;
8792 #if ENABLE_HUSH_LOCAL
8793 static int FAST_FUNC builtin_local(char **argv)
8795 if (G.func_nest_level == 0) {
8796 bb_error_msg("%s: not in a function", argv[0]);
8797 return EXIT_FAILURE; /* bash compat */
8799 helper_export_local(argv, 0, G.func_nest_level);
8800 return EXIT_SUCCESS;
8804 static int FAST_FUNC builtin_trap(char **argv)
8810 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8815 /* No args: print all trapped */
8816 for (i = 0; i < NSIG; ++i) {
8819 print_escaped(G.traps[i]);
8820 /* note: bash adds "SIG", but only if invoked
8821 * as "bash". If called as "sh", or if set -o posix,
8822 * then it prints short signal names.
8823 * We are printing short names: */
8824 printf(" %s\n", get_signame(i));
8827 /*fflush_all(); - done after each builtin anyway */
8828 return EXIT_SUCCESS;
8832 /* If first arg is a number: reset all specified signals */
8833 sig = bb_strtou(*argv, NULL, 10);
8839 sighandler_t handler;
8841 sig = get_signum(*argv++);
8842 if (sig < 0 || sig >= NSIG) {
8844 /* Mimic bash message exactly */
8845 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8850 G.traps[sig] = xstrdup(new_cmd);
8852 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8853 get_signame(sig), sig, G.traps[sig]);
8855 /* There is no signal for 0 (EXIT) */
8860 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
8862 /* We are removing trap handler */
8863 handler = pick_sighandler(sig);
8864 install_sighandler(sig, handler);
8869 if (!argv[1]) { /* no second arg */
8870 bb_error_msg("trap: invalid arguments");
8871 return EXIT_FAILURE;
8874 /* First arg is "-": reset all specified to default */
8875 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8876 /* Everything else: set arg as signal handler
8877 * (includes "" case, which ignores signal) */
8878 if (argv[0][0] == '-') {
8879 if (argv[0][1] == '\0') { /* "-" */
8880 /* new_cmd remains NULL: "reset these sigs" */
8883 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8886 /* else: "-something", no special meaning */
8891 goto process_sig_list;
8894 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8895 static int FAST_FUNC builtin_type(char **argv)
8897 int ret = EXIT_SUCCESS;
8903 if (0) {} /* make conditional compile easier below */
8904 /*else if (find_alias(*argv))
8905 type = "an alias";*/
8906 #if ENABLE_HUSH_FUNCTIONS
8907 else if (find_function(*argv))
8908 type = "a function";
8910 else if (find_builtin(*argv))
8911 type = "a shell builtin";
8912 else if ((path = find_in_path(*argv)) != NULL)
8915 bb_error_msg("type: %s: not found", *argv);
8920 printf("%s is %s\n", *argv, type);
8928 /* built-in 'fg' and 'bg' handler */
8929 static int FAST_FUNC builtin_fg_bg(char **argv)
8934 if (!G_interactive_fd)
8935 return EXIT_FAILURE;
8937 /* If they gave us no args, assume they want the last backgrounded task */
8939 for (pi = G.job_list; pi; pi = pi->next) {
8940 if (pi->jobid == G.last_jobid) {
8944 bb_error_msg("%s: no current job", argv[0]);
8945 return EXIT_FAILURE;
8947 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8948 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8949 return EXIT_FAILURE;
8951 for (pi = G.job_list; pi; pi = pi->next) {
8952 if (pi->jobid == jobnum) {
8956 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8957 return EXIT_FAILURE;
8959 /* TODO: bash prints a string representation
8960 * of job being foregrounded (like "sleep 1 | cat") */
8961 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8962 /* Put the job into the foreground. */
8963 tcsetpgrp(G_interactive_fd, pi->pgrp);
8966 /* Restart the processes in the job */
8967 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8968 for (i = 0; i < pi->num_cmds; i++) {
8969 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8971 pi->stopped_cmds = 0;
8973 i = kill(- pi->pgrp, SIGCONT);
8975 if (errno == ESRCH) {
8976 delete_finished_bg_job(pi);
8977 return EXIT_SUCCESS;
8979 bb_perror_msg("kill (SIGCONT)");
8982 if (argv[0][0] == 'f') {
8984 return checkjobs_and_fg_shell(pi);
8986 return EXIT_SUCCESS;
8990 #if ENABLE_HUSH_HELP
8991 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8993 const struct built_in_command *x;
8996 "Built-in commands:\n"
8997 "------------------\n");
8998 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9000 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9003 return EXIT_SUCCESS;
9007 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9008 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9010 show_history(G.line_input_state);
9011 return EXIT_SUCCESS;
9016 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9019 const char *status_string;
9021 for (job = G.job_list; job; job = job->next) {
9022 if (job->alive_cmds == job->stopped_cmds)
9023 status_string = "Stopped";
9025 status_string = "Running";
9027 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9029 return EXIT_SUCCESS;
9034 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9039 # ifdef M_TRIM_THRESHOLD
9040 /* Optional. Reduces probability of false positives */
9043 /* Crude attempt to find where "free memory" starts,
9044 * sans fragmentation. */
9046 l = (unsigned long)p;
9049 if (l < (unsigned long)p) l = (unsigned long)p;
9052 if (!G.memleak_value)
9053 G.memleak_value = l;
9055 l -= G.memleak_value;
9062 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9067 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9070 return EXIT_SUCCESS;
9073 /* Interruptibility of read builtin in bash
9074 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9076 * Empty trap makes read ignore corresponding signal, for any signal.
9079 * - terminates non-interactive shell;
9080 * - interrupts read in interactive shell;
9081 * if it has non-empty trap:
9082 * - executes trap and returns to command prompt in interactive shell;
9083 * - executes trap and returns to read in non-interactive shell;
9085 * - is ignored (does not interrupt) read in interactive shell;
9086 * - terminates non-interactive shell;
9087 * if it has non-empty trap:
9088 * - executes trap and returns to read;
9090 * - terminates shell (regardless of interactivity);
9091 * if it has non-empty trap:
9092 * - executes trap and returns to read;
9094 static int FAST_FUNC builtin_read(char **argv)
9104 /* "!": do not abort on errors.
9105 * Option string must start with "sr" to match BUILTIN_READ_xxx
9107 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9108 if (read_flags == (uint32_t)-1)
9109 return EXIT_FAILURE;
9111 ifs = get_local_var_value("IFS"); /* can be NULL */
9114 r = shell_builtin_read(set_local_var_from_halves,
9124 if ((uintptr_t)r == 1 && errno == EINTR) {
9125 unsigned sig = check_and_run_traps();
9126 if (sig && sig != SIGINT)
9130 if ((uintptr_t)r > 1) {
9131 bb_error_msg("%s", r);
9132 r = (char*)(uintptr_t)1;
9135 return (uintptr_t)r;
9138 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9139 * built-in 'set' handler
9141 * set [-abCefhmnuvx] [-o option] [argument...]
9142 * set [+abCefhmnuvx] [+o option] [argument...]
9143 * set -- [argument...]
9146 * Implementations shall support the options in both their hyphen and
9147 * plus-sign forms. These options can also be specified as options to sh.
9149 * Write out all variables and their values: set
9150 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9151 * Turn on the -x and -v options: set -xv
9152 * Unset all positional parameters: set --
9153 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9154 * Set the positional parameters to the expansion of x, even if x expands
9155 * with a leading '-' or '+': set -- $x
9157 * So far, we only support "set -- [argument...]" and some of the short names.
9159 static int FAST_FUNC builtin_set(char **argv)
9162 char **pp, **g_argv;
9163 char *arg = *++argv;
9167 for (e = G.top_var; e; e = e->next)
9169 return EXIT_SUCCESS;
9173 if (strcmp(arg, "--") == 0) {
9177 if (arg[0] != '+' && arg[0] != '-')
9179 for (n = 1; arg[n]; ++n) {
9180 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9182 if (arg[n] == 'o' && argv[1])
9185 } while ((arg = *++argv) != NULL);
9186 /* Now argv[0] is 1st argument */
9189 return EXIT_SUCCESS;
9192 /* NB: G.global_argv[0] ($0) is never freed/changed */
9193 g_argv = G.global_argv;
9194 if (G.global_args_malloced) {
9200 G.global_args_malloced = 1;
9201 pp = xzalloc(sizeof(pp[0]) * 2);
9202 pp[0] = g_argv[0]; /* retain $0 */
9205 /* This realloc's G.global_argv */
9206 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9213 return EXIT_SUCCESS;
9215 /* Nothing known, so abort */
9217 bb_error_msg("set: %s: invalid option", arg);
9218 return EXIT_FAILURE;
9221 static int FAST_FUNC builtin_shift(char **argv)
9224 argv = skip_dash_dash(argv);
9228 if (n >= 0 && n < G.global_argc) {
9229 if (G.global_args_malloced) {
9232 free(G.global_argv[m++]);
9235 memmove(&G.global_argv[1], &G.global_argv[n+1],
9236 G.global_argc * sizeof(G.global_argv[0]));
9237 return EXIT_SUCCESS;
9239 return EXIT_FAILURE;
9242 static int FAST_FUNC builtin_source(char **argv)
9244 char *arg_path, *filename;
9247 #if ENABLE_HUSH_FUNCTIONS
9251 argv = skip_dash_dash(argv);
9254 /* bash says: "bash: .: filename argument required" */
9255 return 2; /* bash compat */
9258 if (!strchr(filename, '/')) {
9259 arg_path = find_in_path(filename);
9261 filename = arg_path;
9263 input = remember_FILE(fopen_or_warn(filename, "r"));
9266 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9267 /* POSIX: non-interactive shell should abort here,
9268 * not merely fail. So far no one complained :)
9270 return EXIT_FAILURE;
9273 #if ENABLE_HUSH_FUNCTIONS
9274 sv_flg = G.flag_return_in_progress;
9275 /* "we are inside sourced file, ok to use return" */
9276 G.flag_return_in_progress = -1;
9279 save_and_replace_G_args(&sv, argv);
9281 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9282 G.last_exitcode = 0;
9283 parse_and_run_file(input);
9284 fclose_and_forget(input);
9287 restore_G_args(&sv, argv);
9288 #if ENABLE_HUSH_FUNCTIONS
9289 G.flag_return_in_progress = sv_flg;
9292 return G.last_exitcode;
9295 static int FAST_FUNC builtin_umask(char **argv)
9302 argv = skip_dash_dash(argv);
9304 mode_t old_mask = mask;
9306 /* numeric umasks are taken as-is */
9307 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9308 if (!isdigit(argv[0][0]))
9310 mask = bb_parse_mode(argv[0], mask);
9311 if (!isdigit(argv[0][0]))
9313 if ((unsigned)mask > 0777) {
9316 * bash: umask: 'q': invalid symbolic mode operator
9317 * bash: umask: 999: octal number out of range
9319 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9324 printf("%04o\n", (unsigned) mask);
9325 /* fall through and restore mask which we set to 0 */
9329 return !rc; /* rc != 0 - success */
9332 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9333 static int FAST_FUNC builtin_unset(char **argv)
9338 /* "!": do not abort on errors */
9339 /* "+": stop at 1st non-option */
9340 opts = getopt32(argv, "!+vf");
9341 if (opts == (unsigned)-1)
9342 return EXIT_FAILURE;
9344 bb_error_msg("unset: -v and -f are exclusive");
9345 return EXIT_FAILURE;
9351 if (!(opts & 2)) { /* not -f */
9352 if (unset_local_var(*argv)) {
9353 /* unset <nonexistent_var> doesn't fail.
9354 * Error is when one tries to unset RO var.
9355 * Message was printed by unset_local_var. */
9359 #if ENABLE_HUSH_FUNCTIONS
9369 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9370 static int FAST_FUNC builtin_wait(char **argv)
9372 int ret = EXIT_SUCCESS;
9375 argv = skip_dash_dash(argv);
9376 if (argv[0] == NULL) {
9377 /* Don't care about wait results */
9378 /* Note 1: must wait until there are no more children */
9379 /* Note 2: must be interruptible */
9381 * $ sleep 3 & sleep 6 & wait
9386 * $ sleep 3 & sleep 6 & wait
9390 * ^C <-- after ~4 sec from keyboard
9395 sigset_t oldset, allsigs;
9397 /* waitpid is not interruptible by SA_RESTARTed
9398 * signals which we use. Thus, this ugly dance:
9401 /* Make sure possible SIGCHLD is stored in kernel's
9402 * pending signal mask before we call waitpid.
9403 * Or else we may race with SIGCHLD, lose it,
9404 * and get stuck in sigwaitinfo...
9406 sigfillset(&allsigs);
9407 sigprocmask(SIG_SETMASK, &allsigs, &oldset);
9409 if (!sigisemptyset(&G.pending_set)) {
9410 /* Crap! we raced with some signal! */
9415 checkjobs(NULL); /* waitpid(WNOHANG) inside */
9416 if (errno == ECHILD) {
9417 sigprocmask(SIG_SETMASK, &oldset, NULL);
9421 /* Wait for SIGCHLD or any other signal */
9422 //sig = sigwaitinfo(&allsigs, NULL);
9423 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9424 /* Note: sigsuspend invokes signal handler */
9425 sigsuspend(&oldset);
9427 sigprocmask(SIG_SETMASK, &oldset, NULL);
9429 /* So, did we get a signal? */
9431 // raise(sig); /* run handler */
9432 sig = check_and_run_traps();
9433 if (sig /*&& sig != SIGCHLD - always true */) {
9438 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9443 /* This is probably buggy wrt interruptible-ness */
9445 pid_t pid = bb_strtou(*argv, NULL, 10);
9447 /* mimic bash message */
9448 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9449 return EXIT_FAILURE;
9451 if (waitpid(pid, &status, 0) == pid) {
9452 ret = WEXITSTATUS(status);
9453 if (WIFSIGNALED(status))
9454 ret = 128 + WTERMSIG(status);
9456 bb_perror_msg("wait %s", *argv);
9465 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9466 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9469 def = bb_strtou(argv[1], NULL, 10);
9470 if (errno || def < def_min || argv[2]) {
9471 bb_error_msg("%s: bad arguments", argv[0]);
9479 #if ENABLE_HUSH_LOOPS
9480 static int FAST_FUNC builtin_break(char **argv)
9483 if (G.depth_of_loop == 0) {
9484 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9485 /* if we came from builtin_continue(), need to undo "= 1" */
9486 G.flag_break_continue = 0;
9487 return EXIT_SUCCESS; /* bash compat */
9489 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9491 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9492 if (depth == UINT_MAX)
9493 G.flag_break_continue = BC_BREAK;
9494 if (G.depth_of_loop < depth)
9495 G.depth_break_continue = G.depth_of_loop;
9497 return EXIT_SUCCESS;
9500 static int FAST_FUNC builtin_continue(char **argv)
9502 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9503 return builtin_break(argv);
9507 #if ENABLE_HUSH_FUNCTIONS
9508 static int FAST_FUNC builtin_return(char **argv)
9512 if (G.flag_return_in_progress != -1) {
9513 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9514 return EXIT_FAILURE; /* bash compat */
9517 G.flag_return_in_progress = 1;
9520 * out of range: wraps around at 256, does not error out
9521 * non-numeric param:
9522 * f() { false; return qwe; }; f; echo $?
9523 * bash: return: qwe: numeric argument required <== we do this
9524 * 255 <== we also do this
9526 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);