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;
780 # define G_flag_return_in_progress (G.flag_return_in_progress)
782 # define G_flag_return_in_progress 0
784 smallint exiting; /* used to prevent EXIT trap recursion */
785 /* These four support $?, $#, and $1 */
786 smalluint last_exitcode;
787 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
788 smalluint global_args_malloced;
789 /* how many non-NULL argv's we have. NB: $# + 1 */
793 char *argv0_for_re_execing;
795 #if ENABLE_HUSH_LOOPS
796 unsigned depth_break_continue;
797 unsigned depth_of_loop;
801 struct variable *top_var;
802 char **expanded_assignments;
803 #if ENABLE_HUSH_FUNCTIONS
804 struct function *top_func;
805 # if ENABLE_HUSH_LOCAL
806 struct variable **shadowed_vars_pp;
807 unsigned func_nest_level;
810 /* Signal and trap handling */
812 unsigned count_SIGCHLD;
813 unsigned handled_SIGCHLD;
814 smallint we_have_children;
816 struct FILE_list *FILE_list;
817 /* Which signals have non-DFL handler (even with no traps set)?
818 * Set at the start to:
819 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
820 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
821 * The rest is cleared right before execv syscalls.
822 * Other than these two times, never modified.
824 unsigned special_sig_mask;
826 unsigned fatal_sig_mask;
827 # define G_fatal_sig_mask G.fatal_sig_mask
829 # define G_fatal_sig_mask 0
831 char **traps; /* char *traps[NSIG] */
832 sigset_t pending_set;
834 unsigned long memleak_value;
838 #if ENABLE_FEATURE_EDITING
839 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
842 #define G (*ptr_to_globals)
843 /* Not #defining name to G.name - this quickly gets unwieldy
844 * (too many defines). Also, I actually prefer to see when a variable
845 * is global, thus "G." prefix is a useful hint */
846 #define INIT_G() do { \
847 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
848 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
849 sigfillset(&G.sa.sa_mask); \
850 G.sa.sa_flags = SA_RESTART; \
854 /* Function prototypes for builtins */
855 static int builtin_cd(char **argv) FAST_FUNC;
856 static int builtin_echo(char **argv) FAST_FUNC;
857 static int builtin_eval(char **argv) FAST_FUNC;
858 static int builtin_exec(char **argv) FAST_FUNC;
859 static int builtin_exit(char **argv) FAST_FUNC;
860 static int builtin_export(char **argv) FAST_FUNC;
862 static int builtin_fg_bg(char **argv) FAST_FUNC;
863 static int builtin_jobs(char **argv) FAST_FUNC;
866 static int builtin_help(char **argv) FAST_FUNC;
868 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
869 static int builtin_history(char **argv) FAST_FUNC;
871 #if ENABLE_HUSH_LOCAL
872 static int builtin_local(char **argv) FAST_FUNC;
875 static int builtin_memleak(char **argv) FAST_FUNC;
878 static int builtin_printf(char **argv) FAST_FUNC;
880 static int builtin_pwd(char **argv) FAST_FUNC;
881 static int builtin_read(char **argv) FAST_FUNC;
882 static int builtin_set(char **argv) FAST_FUNC;
883 static int builtin_shift(char **argv) FAST_FUNC;
884 static int builtin_source(char **argv) FAST_FUNC;
885 static int builtin_test(char **argv) FAST_FUNC;
886 static int builtin_trap(char **argv) FAST_FUNC;
887 static int builtin_type(char **argv) FAST_FUNC;
888 static int builtin_true(char **argv) FAST_FUNC;
889 static int builtin_umask(char **argv) FAST_FUNC;
890 static int builtin_unset(char **argv) FAST_FUNC;
891 static int builtin_wait(char **argv) FAST_FUNC;
892 #if ENABLE_HUSH_LOOPS
893 static int builtin_break(char **argv) FAST_FUNC;
894 static int builtin_continue(char **argv) FAST_FUNC;
896 #if ENABLE_HUSH_FUNCTIONS
897 static int builtin_return(char **argv) FAST_FUNC;
900 /* Table of built-in functions. They can be forked or not, depending on
901 * context: within pipes, they fork. As simple commands, they do not.
902 * When used in non-forking context, they can change global variables
903 * in the parent shell process. If forked, of course they cannot.
904 * For example, 'unset foo | whatever' will parse and run, but foo will
905 * still be set at the end. */
906 struct built_in_command {
908 int (*b_function)(char **argv) FAST_FUNC;
911 # define BLTIN(cmd, func, help) { cmd, func, help }
913 # define BLTIN(cmd, func, help) { cmd, func }
917 static const struct built_in_command bltins1[] = {
918 BLTIN("." , builtin_source , "Run commands in a file"),
919 BLTIN(":" , builtin_true , NULL),
921 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
923 #if ENABLE_HUSH_LOOPS
924 BLTIN("break" , builtin_break , "Exit from a loop"),
926 BLTIN("cd" , builtin_cd , "Change directory"),
927 #if ENABLE_HUSH_LOOPS
928 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
930 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
931 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
932 BLTIN("exit" , builtin_exit , "Exit"),
933 BLTIN("export" , builtin_export , "Set environment variables"),
935 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
938 BLTIN("help" , builtin_help , NULL),
940 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
941 BLTIN("history" , builtin_history , "Show command history"),
944 BLTIN("jobs" , builtin_jobs , "List jobs"),
946 #if ENABLE_HUSH_LOCAL
947 BLTIN("local" , builtin_local , "Set local variables"),
950 BLTIN("memleak" , builtin_memleak , NULL),
952 BLTIN("read" , builtin_read , "Input into variable"),
953 #if ENABLE_HUSH_FUNCTIONS
954 BLTIN("return" , builtin_return , "Return from a function"),
956 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
957 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
958 #if ENABLE_HUSH_BASH_COMPAT
959 BLTIN("source" , builtin_source , "Run commands in a file"),
961 BLTIN("trap" , builtin_trap , "Trap signals"),
962 BLTIN("true" , builtin_true , NULL),
963 BLTIN("type" , builtin_type , "Show command type"),
964 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
965 BLTIN("umask" , builtin_umask , "Set file creation mask"),
966 BLTIN("unset" , builtin_unset , "Unset variables"),
967 BLTIN("wait" , builtin_wait , "Wait for process"),
969 /* For now, echo and test are unconditionally enabled.
970 * Maybe make it configurable? */
971 static const struct built_in_command bltins2[] = {
972 BLTIN("[" , builtin_test , NULL),
973 BLTIN("echo" , builtin_echo , NULL),
975 BLTIN("printf" , builtin_printf , NULL),
977 BLTIN("pwd" , builtin_pwd , NULL),
978 BLTIN("test" , builtin_test , NULL),
985 /* prevent disasters with G.debug_indent < 0 */
986 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
987 # define debug_enter() (G.debug_indent++)
988 # define debug_leave() (G.debug_indent--)
990 # define indent() ((void)0)
991 # define debug_enter() ((void)0)
992 # define debug_leave() ((void)0)
996 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
999 #ifndef debug_printf_parse
1000 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1003 #ifndef debug_printf_exec
1004 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1007 #ifndef debug_printf_env
1008 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1011 #ifndef debug_printf_jobs
1012 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1013 # define DEBUG_JOBS 1
1015 # define DEBUG_JOBS 0
1018 #ifndef debug_printf_expand
1019 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1020 # define DEBUG_EXPAND 1
1022 # define DEBUG_EXPAND 0
1025 #ifndef debug_printf_varexp
1026 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1029 #ifndef debug_printf_glob
1030 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1031 # define DEBUG_GLOB 1
1033 # define DEBUG_GLOB 0
1036 #ifndef debug_printf_list
1037 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1040 #ifndef debug_printf_subst
1041 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1044 #ifndef debug_printf_clean
1045 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1046 # define DEBUG_CLEAN 1
1048 # define DEBUG_CLEAN 0
1052 static void debug_print_strings(const char *prefix, char **vv)
1055 fdprintf(2, "%s:\n", prefix);
1057 fdprintf(2, " '%s'\n", *vv++);
1060 # define debug_print_strings(prefix, vv) ((void)0)
1064 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1067 static void *xxmalloc(int lineno, size_t size)
1069 void *ptr = xmalloc((size + 0xff) & ~0xff);
1070 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1073 static void *xxrealloc(int lineno, void *ptr, size_t size)
1075 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1076 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1079 static char *xxstrdup(int lineno, const char *str)
1081 char *ptr = xstrdup(str);
1082 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1085 static void xxfree(void *ptr)
1087 fdprintf(2, "free %p\n", ptr);
1090 # define xmalloc(s) xxmalloc(__LINE__, s)
1091 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1092 # define xstrdup(s) xxstrdup(__LINE__, s)
1093 # define free(p) xxfree(p)
1097 /* Syntax and runtime errors. They always abort scripts.
1098 * In interactive use they usually discard unparsed and/or unexecuted commands
1099 * and return to the prompt.
1100 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1103 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1104 # define syntax_error(lineno, msg) syntax_error(msg)
1105 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1106 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1107 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1108 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1111 static void die_if_script(unsigned lineno, const char *fmt, ...)
1116 bb_error_msg("hush.c:%u", lineno);
1119 bb_verror_msg(fmt, p, NULL);
1121 if (!G_interactive_fd)
1125 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1128 bb_error_msg("syntax error: %s", msg);
1130 bb_error_msg("syntax error");
1133 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1135 bb_error_msg("syntax error at '%s'", msg);
1138 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1140 bb_error_msg("syntax error: unterminated %s", s);
1143 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1145 char msg[2] = { ch, '\0' };
1146 syntax_error_unterm_str(lineno, msg);
1149 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1154 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1158 # undef die_if_script
1159 # undef syntax_error
1160 # undef syntax_error_at
1161 # undef syntax_error_unterm_ch
1162 # undef syntax_error_unterm_str
1163 # undef syntax_error_unexpected_ch
1165 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1166 # define syntax_error(msg) syntax_error(__LINE__, msg)
1167 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1168 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1169 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1170 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1174 #if ENABLE_HUSH_INTERACTIVE
1175 static void cmdedit_update_prompt(void);
1177 # define cmdedit_update_prompt() ((void)0)
1181 /* Utility functions
1183 /* Replace each \x with x in place, return ptr past NUL. */
1184 static char *unbackslash(char *src)
1186 char *dst = src = strchrnul(src, '\\');
1190 if ((*dst++ = *src++) == '\0')
1196 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1217 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1218 v[count1 + count2] = NULL;
1221 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1225 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1227 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1228 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1231 #define add_strings_to_strings(strings, add, need_to_dup) \
1232 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1235 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1236 static char **add_string_to_strings(char **strings, char *add)
1241 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1244 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1246 char **ptr = add_string_to_strings(strings, add);
1247 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1250 #define add_string_to_strings(strings, add) \
1251 xx_add_string_to_strings(__LINE__, strings, add)
1254 static void free_strings(char **strings)
1269 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1271 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1272 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1274 /* fd was not open? */
1284 /* Manipulating the list of open FILEs */
1285 static FILE *remember_FILE(FILE *fp)
1288 struct FILE_list *n = xmalloc(sizeof(*n));
1289 n->next = G.FILE_list;
1293 close_on_exec_on(n->fd);
1297 static void fclose_and_forget(FILE *fp)
1299 struct FILE_list **pp = &G.FILE_list;
1301 struct FILE_list *cur = *pp;
1302 if (cur->fp == fp) {
1311 static int save_FILEs_on_redirect(int fd)
1313 struct FILE_list *fl = G.FILE_list;
1316 /* We use it only on script files, they are all CLOEXEC */
1317 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1324 static void restore_redirected_FILEs(void)
1326 struct FILE_list *fl = G.FILE_list;
1328 int should_be = fileno(fl->fp);
1329 if (fl->fd != should_be) {
1330 xmove_fd(fl->fd, should_be);
1336 #if ENABLE_FEATURE_SH_STANDALONE
1337 static void close_all_FILE_list(void)
1339 struct FILE_list *fl = G.FILE_list;
1341 /* fclose would also free FILE object.
1342 * It is disastrous if we share memory with a vforked parent.
1343 * I'm not sure we never come here after vfork.
1344 * Therefore just close fd, nothing more.
1346 /*fclose(fl->fp); - unsafe */
1354 /* Helpers for setting new $n and restoring them back
1356 typedef struct save_arg_t {
1360 smallint sv_g_malloced;
1363 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1367 sv->sv_argv0 = argv[0];
1368 sv->sv_g_argv = G.global_argv;
1369 sv->sv_g_argc = G.global_argc;
1370 sv->sv_g_malloced = G.global_args_malloced;
1372 argv[0] = G.global_argv[0]; /* retain $0 */
1373 G.global_argv = argv;
1374 G.global_args_malloced = 0;
1382 static void restore_G_args(save_arg_t *sv, char **argv)
1386 if (G.global_args_malloced) {
1387 /* someone ran "set -- arg1 arg2 ...", undo */
1389 while (*++pp) /* note: does not free $0 */
1391 free(G.global_argv);
1393 argv[0] = sv->sv_argv0;
1394 G.global_argv = sv->sv_g_argv;
1395 G.global_argc = sv->sv_g_argc;
1396 G.global_args_malloced = sv->sv_g_malloced;
1400 /* Basic theory of signal handling in shell
1401 * ========================================
1402 * This does not describe what hush does, rather, it is current understanding
1403 * what it _should_ do. If it doesn't, it's a bug.
1404 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1406 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1407 * is finished or backgrounded. It is the same in interactive and
1408 * non-interactive shells, and is the same regardless of whether
1409 * a user trap handler is installed or a shell special one is in effect.
1410 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1411 * backgrounds (i.e. stops) or kills all members of currently running
1414 * Wait builtin is interruptible by signals for which user trap is set
1415 * or by SIGINT in interactive shell.
1417 * Trap handlers will execute even within trap handlers. (right?)
1419 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1420 * except for handlers set to '' (empty string).
1422 * If job control is off, backgrounded commands ("cmd &")
1423 * have SIGINT, SIGQUIT set to SIG_IGN.
1425 * Commands which are run in command substitution ("`cmd`")
1426 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1428 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1429 * by the shell from its parent.
1431 * Signals which differ from SIG_DFL action
1432 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1435 * SIGTERM (interactive): ignore
1436 * SIGHUP (interactive):
1437 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1438 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1439 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1440 * that all pipe members are stopped. Try this in bash:
1441 * while :; do :; done - ^Z does not background it
1442 * (while :; do :; done) - ^Z backgrounds it
1443 * SIGINT (interactive): wait for last pipe, ignore the rest
1444 * of the command line, show prompt. NB: ^C does not send SIGINT
1445 * to interactive shell while shell is waiting for a pipe,
1446 * since shell is bg'ed (is not in foreground process group).
1447 * Example 1: this waits 5 sec, but does not execute ls:
1448 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1449 * Example 2: this does not wait and does not execute ls:
1450 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1451 * Example 3: this does not wait 5 sec, but executes ls:
1452 * "sleep 5; ls -l" + press ^C
1453 * Example 4: this does not wait and does not execute ls:
1454 * "sleep 5 & wait; ls -l" + press ^C
1456 * (What happens to signals which are IGN on shell start?)
1457 * (What happens with signal mask on shell start?)
1459 * Old implementation
1460 * ==================
1461 * We use in-kernel pending signal mask to determine which signals were sent.
1462 * We block all signals which we don't want to take action immediately,
1463 * i.e. we block all signals which need to have special handling as described
1464 * above, and all signals which have traps set.
1465 * After each pipe execution, we extract any pending signals via sigtimedwait()
1468 * unsigned special_sig_mask: a mask of such "special" signals
1469 * sigset_t blocked_set: current blocked signal set
1472 * clear bit in blocked_set unless it is also in special_sig_mask
1473 * "trap 'cmd' SIGxxx":
1474 * set bit in blocked_set (even if 'cmd' is '')
1475 * after [v]fork, if we plan to be a shell:
1476 * unblock signals with special interactive handling
1477 * (child shell is not interactive),
1478 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1479 * after [v]fork, if we plan to exec:
1480 * POSIX says fork clears pending signal mask in child - no need to clear it.
1481 * Restore blocked signal set to one inherited by shell just prior to exec.
1483 * Note: as a result, we do not use signal handlers much. The only uses
1484 * are to count SIGCHLDs
1485 * and to restore tty pgrp on signal-induced exit.
1488 * Standard says "When a subshell is entered, traps that are not being ignored
1489 * are set to the default actions". bash interprets it so that traps which
1490 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1492 * Problem: the above approach makes it unwieldy to catch signals while
1493 * we are in read builtin, or while we read commands from stdin:
1494 * masked signals are not visible!
1496 * New implementation
1497 * ==================
1498 * We record each signal we are interested in by installing signal handler
1499 * for them - a bit like emulating kernel pending signal mask in userspace.
1500 * We are interested in: signals which need to have special handling
1501 * as described above, and all signals which have traps set.
1502 * Signals are recorded in pending_set.
1503 * After each pipe execution, we extract any pending signals
1506 * unsigned special_sig_mask: a mask of shell-special signals.
1507 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1508 * char *traps[sig] if trap for sig is set (even if it's '').
1509 * sigset_t pending_set: set of sigs we received.
1512 * if sig is in special_sig_mask, set handler back to:
1513 * record_pending_signo, or to IGN if it's a tty stop signal
1514 * if sig is in fatal_sig_mask, set handler back to sigexit.
1515 * else: set handler back to SIG_DFL
1516 * "trap 'cmd' SIGxxx":
1517 * set handler to record_pending_signo.
1519 * set handler to SIG_IGN.
1520 * after [v]fork, if we plan to be a shell:
1521 * set signals with special interactive handling to SIG_DFL
1522 * (because child shell is not interactive),
1523 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1524 * after [v]fork, if we plan to exec:
1525 * POSIX says fork clears pending signal mask in child - no need to clear it.
1527 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1528 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1531 * Standard says "When a subshell is entered, traps that are not being ignored
1532 * are set to the default actions". bash interprets it so that traps which
1533 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1536 SPECIAL_INTERACTIVE_SIGS = 0
1541 SPECIAL_JOBSTOP_SIGS = 0
1550 static void record_pending_signo(int sig)
1552 sigaddset(&G.pending_set, sig);
1553 #if ENABLE_HUSH_FAST
1554 if (sig == SIGCHLD) {
1556 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1561 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1563 struct sigaction old_sa;
1565 /* We could use signal() to install handlers... almost:
1566 * except that we need to mask ALL signals while handlers run.
1567 * I saw signal nesting in strace, race window isn't small.
1568 * SA_RESTART is also needed, but in Linux, signal()
1569 * sets SA_RESTART too.
1571 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1572 /* sigfillset(&G.sa.sa_mask); - already done */
1573 /* G.sa.sa_flags = SA_RESTART; - already done */
1574 G.sa.sa_handler = handler;
1575 sigaction(sig, &G.sa, &old_sa);
1576 return old_sa.sa_handler;
1579 static void hush_exit(int exitcode) NORETURN;
1580 static void fflush_and__exit(void) NORETURN;
1581 static void restore_ttypgrp_and__exit(void) NORETURN;
1583 static void restore_ttypgrp_and__exit(void)
1585 /* xfunc has failed! die die die */
1586 /* no EXIT traps, this is an escape hatch! */
1588 hush_exit(xfunc_error_retval);
1591 /* Needed only on some libc:
1592 * It was observed that on exit(), fgetc'ed buffered data
1593 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1594 * With the net effect that even after fork(), not vfork(),
1595 * exit() in NOEXECed applet in "sh SCRIPT":
1596 * noexec_applet_here
1597 * echo END_OF_SCRIPT
1598 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1599 * This makes "echo END_OF_SCRIPT" executed twice.
1600 * Similar problems can be seen with die_if_script() -> xfunc_die()
1601 * and in `cmd` handling.
1602 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1604 static void fflush_and__exit(void)
1607 _exit(xfunc_error_retval);
1612 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1613 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1614 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1615 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1617 /* Restores tty foreground process group, and exits.
1618 * May be called as signal handler for fatal signal
1619 * (will resend signal to itself, producing correct exit state)
1620 * or called directly with -EXITCODE.
1621 * We also call it if xfunc is exiting.
1623 static void sigexit(int sig) NORETURN;
1624 static void sigexit(int sig)
1626 /* Careful: we can end up here after [v]fork. Do not restore
1627 * tty pgrp then, only top-level shell process does that */
1628 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1629 /* Disable all signals: job control, SIGPIPE, etc.
1630 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1632 sigprocmask_allsigs(SIG_BLOCK);
1633 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1636 /* Not a signal, just exit */
1640 kill_myself_with_sig(sig); /* does not return */
1644 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1645 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1649 static sighandler_t pick_sighandler(unsigned sig)
1651 sighandler_t handler = SIG_DFL;
1652 if (sig < sizeof(unsigned)*8) {
1653 unsigned sigmask = (1 << sig);
1657 if (G_fatal_sig_mask & sigmask)
1661 /* sig has special handling? */
1662 if (G.special_sig_mask & sigmask) {
1663 handler = record_pending_signo;
1664 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1665 * in order to ignore them: they will be raised
1666 * in an endless loop when we try to do some
1667 * terminal ioctls! We do have to _ignore_ these.
1669 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1676 /* Restores tty foreground process group, and exits. */
1677 static void hush_exit(int exitcode)
1679 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1680 save_history(G.line_input_state);
1684 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1686 /* argv[0] is unused */
1687 argv[1] = G.traps[0];
1689 G.exiting = 1; /* prevent EXIT trap recursion */
1690 /* Note: G.traps[0] is not cleared!
1691 * "trap" will still show it, if executed
1696 #if ENABLE_FEATURE_CLEAN_UP
1698 struct variable *cur_var;
1699 if (G.cwd != bb_msg_unknown)
1701 cur_var = G.top_var;
1703 struct variable *tmp = cur_var;
1704 if (!cur_var->max_len)
1705 free(cur_var->varstr);
1706 cur_var = cur_var->next;
1714 sigexit(- (exitcode & 0xff));
1721 //TODO: return a mask of ALL handled sigs?
1722 static int check_and_run_traps(void)
1729 if (sigisemptyset(&G.pending_set))
1734 if (sigismember(&G.pending_set, sig)) {
1735 sigdelset(&G.pending_set, sig);
1738 } while (sig < NSIG);
1741 if (G.traps && G.traps[sig]) {
1742 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1743 if (G.traps[sig][0]) {
1744 /* We have user-defined handler */
1745 smalluint save_rcode;
1747 /* argv[0] is unused */
1748 argv[1] = G.traps[sig];
1750 save_rcode = G.last_exitcode;
1752 G.last_exitcode = save_rcode;
1754 } /* else: "" trap, ignoring signal */
1757 /* not a trap: special action */
1760 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1761 /* Builtin was ^C'ed, make it look prettier: */
1769 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1770 /* bash is observed to signal whole process groups,
1771 * not individual processes */
1772 for (job = G.job_list; job; job = job->next) {
1775 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1776 if (kill(- job->pgrp, SIGHUP) == 0)
1777 kill(- job->pgrp, SIGCONT);
1782 #if ENABLE_HUSH_FAST
1784 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1786 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1788 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1789 * This simplifies wait builtin a bit.
1793 default: /* ignored: */
1794 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1795 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1797 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1798 * Example: wait is not interrupted by TERM
1799 * in interactive shell, because TERM is ignored.
1808 static const char *get_cwd(int force)
1810 if (force || G.cwd == NULL) {
1811 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1812 * we must not try to free(bb_msg_unknown) */
1813 if (G.cwd == bb_msg_unknown)
1815 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1817 G.cwd = bb_msg_unknown;
1824 * Shell and environment variable support
1826 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1828 struct variable **pp;
1829 struct variable *cur;
1832 while ((cur = *pp) != NULL) {
1833 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1840 static const char* FAST_FUNC get_local_var_value(const char *name)
1842 struct variable **vpp;
1843 unsigned len = strlen(name);
1845 if (G.expanded_assignments) {
1846 char **cpp = G.expanded_assignments;
1849 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1850 return cp + len + 1;
1855 vpp = get_ptr_to_local_var(name, len);
1857 return (*vpp)->varstr + len + 1;
1859 if (strcmp(name, "PPID") == 0)
1860 return utoa(G.root_ppid);
1861 // bash compat: UID? EUID?
1862 #if ENABLE_HUSH_RANDOM_SUPPORT
1863 if (strcmp(name, "RANDOM") == 0)
1864 return utoa(next_random(&G.random_gen));
1869 /* str holds "NAME=VAL" and is expected to be malloced.
1870 * We take ownership of it.
1872 * 0: do not change export flag
1873 * (if creating new variable, flag will be 0)
1874 * 1: set export flag and putenv the variable
1875 * -1: clear export flag and unsetenv the variable
1876 * flg_read_only is set only when we handle -R var=val
1878 #if !BB_MMU && ENABLE_HUSH_LOCAL
1879 /* all params are used */
1880 #elif BB_MMU && ENABLE_HUSH_LOCAL
1881 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1882 set_local_var(str, flg_export, local_lvl)
1883 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1884 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1885 set_local_var(str, flg_export)
1886 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1887 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1888 set_local_var(str, flg_export, flg_read_only)
1890 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1892 struct variable **var_pp;
1893 struct variable *cur;
1894 char *free_me = NULL;
1898 eq_sign = strchr(str, '=');
1899 if (!eq_sign) { /* not expected to ever happen? */
1904 name_len = eq_sign - str + 1; /* including '=' */
1905 var_pp = &G.top_var;
1906 while ((cur = *var_pp) != NULL) {
1907 if (strncmp(cur->varstr, str, name_len) != 0) {
1908 var_pp = &cur->next;
1912 /* We found an existing var with this name */
1913 if (cur->flg_read_only) {
1917 bb_error_msg("%s: readonly variable", str);
1921 if (flg_export == -1) { // "&& cur->flg_export" ?
1922 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1927 #if ENABLE_HUSH_LOCAL
1928 if (cur->func_nest_level < local_lvl) {
1929 /* New variable is declared as local,
1930 * and existing one is global, or local
1931 * from enclosing function.
1932 * Remove and save old one: */
1933 *var_pp = cur->next;
1934 cur->next = *G.shadowed_vars_pp;
1935 *G.shadowed_vars_pp = cur;
1936 /* bash 3.2.33(1) and exported vars:
1938 * # f() { local z=a; env | grep ^z; }
1944 if (cur->flg_export)
1949 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1954 if (cur->max_len != 0) {
1955 if (cur->max_len >= strlen(str)) {
1956 /* This one is from startup env, reuse space */
1957 strcpy(cur->varstr, str);
1962 goto set_str_and_exp;
1964 /* max_len == 0 signifies "malloced" var, which we can
1965 * (and have to) free. But we can't free(cur->varstr) here:
1966 * if cur->flg_export is 1, it is in the environment.
1967 * We should either unsetenv+free, or wait until putenv,
1968 * then putenv(new)+free(old).
1970 free_me = cur->varstr;
1971 goto set_str_and_exp;
1974 /* Not found - create new variable struct */
1975 cur = xzalloc(sizeof(*cur));
1976 #if ENABLE_HUSH_LOCAL
1977 cur->func_nest_level = local_lvl;
1979 cur->next = *var_pp;
1985 cur->flg_read_only = flg_read_only;
1988 if (flg_export == 1)
1989 cur->flg_export = 1;
1990 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1991 cmdedit_update_prompt();
1992 if (cur->flg_export) {
1993 if (flg_export == -1) {
1994 cur->flg_export = 0;
1995 /* unsetenv was already done */
1998 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1999 i = putenv(cur->varstr);
2000 /* only now we can free old exported malloced string */
2009 /* Used at startup and after each cd */
2010 static void set_pwd_var(int exp)
2012 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2013 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2016 static int unset_local_var_len(const char *name, int name_len)
2018 struct variable *cur;
2019 struct variable **var_pp;
2022 return EXIT_SUCCESS;
2023 var_pp = &G.top_var;
2024 while ((cur = *var_pp) != NULL) {
2025 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2026 if (cur->flg_read_only) {
2027 bb_error_msg("%s: readonly variable", name);
2028 return EXIT_FAILURE;
2030 *var_pp = cur->next;
2031 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2032 bb_unsetenv(cur->varstr);
2033 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2034 cmdedit_update_prompt();
2038 return EXIT_SUCCESS;
2040 var_pp = &cur->next;
2042 return EXIT_SUCCESS;
2045 static int unset_local_var(const char *name)
2047 return unset_local_var_len(name, strlen(name));
2050 static void unset_vars(char **strings)
2058 const char *eq = strchrnul(*v, '=');
2059 unset_local_var_len(*v, (int)(eq - *v));
2065 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2067 char *var = xasprintf("%s=%s", name, val);
2068 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2073 * Helpers for "var1=val1 var2=val2 cmd" feature
2075 static void add_vars(struct variable *var)
2077 struct variable *next;
2081 var->next = G.top_var;
2083 if (var->flg_export) {
2084 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2085 putenv(var->varstr);
2087 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2093 static struct variable *set_vars_and_save_old(char **strings)
2096 struct variable *old = NULL;
2102 struct variable *var_p;
2103 struct variable **var_pp;
2106 eq = strchr(*s, '=');
2108 var_pp = get_ptr_to_local_var(*s, eq - *s);
2110 /* Remove variable from global linked list */
2112 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2113 *var_pp = var_p->next;
2114 /* Add it to returned list */
2118 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2129 static void reinit_unicode_for_hush(void)
2131 /* Unicode support should be activated even if LANG is set
2132 * _during_ shell execution, not only if it was set when
2133 * shell was started. Therefore, re-check LANG every time:
2135 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2136 || ENABLE_UNICODE_USING_LOCALE
2138 const char *s = get_local_var_value("LC_ALL");
2139 if (!s) s = get_local_var_value("LC_CTYPE");
2140 if (!s) s = get_local_var_value("LANG");
2146 * in_str support (strings, and "strings" read from files).
2149 #if ENABLE_HUSH_INTERACTIVE
2150 /* To test correct lineedit/interactive behavior, type from command line:
2156 * It excercises a lot of corner cases.
2158 static void cmdedit_update_prompt(void)
2160 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2161 G.PS1 = get_local_var_value("PS1");
2164 G.PS2 = get_local_var_value("PS2");
2171 static const char *setup_prompt_string(int promptmode)
2173 const char *prompt_str;
2174 debug_printf("setup_prompt_string %d ", promptmode);
2175 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2176 /* Set up the prompt */
2177 if (promptmode == 0) { /* PS1 */
2179 /* bash uses $PWD value, even if it is set by user.
2180 * It uses current dir only if PWD is unset.
2181 * We always use current dir. */
2182 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2187 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2188 debug_printf("prompt_str '%s'\n", prompt_str);
2191 static int get_user_input(struct in_str *i)
2194 const char *prompt_str;
2196 prompt_str = setup_prompt_string(i->promptmode);
2197 # if ENABLE_FEATURE_EDITING
2199 reinit_unicode_for_hush();
2201 /* buglet: SIGINT will not make new prompt to appear _at once_,
2202 * only after <Enter>. (^C will work) */
2203 r = read_line_input(G.line_input_state, prompt_str,
2204 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2207 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2208 check_and_run_traps();
2209 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2211 /* EOF/error detected */
2213 i->peek_buf[0] = r = EOF;
2216 i->p = G.user_input_buf;
2217 return (unsigned char)*i->p++;
2221 if (i->last_char == '\0' || i->last_char == '\n') {
2222 /* Why check_and_run_traps here? Try this interactively:
2223 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2224 * $ <[enter], repeatedly...>
2225 * Without check_and_run_traps, handler never runs.
2227 check_and_run_traps();
2228 fputs(prompt_str, stdout);
2232 } while (G.flag_SIGINT || r == '\0');
2236 /* This is the magic location that prints prompts
2237 * and gets data back from the user */
2238 static int fgetc_interactive(struct in_str *i)
2241 /* If it's interactive stdin, get new line. */
2242 if (G_interactive_fd && i->file == stdin) {
2243 /* Returns first char (or EOF), the rest is in i->p[] */
2244 ch = get_user_input(i);
2245 i->promptmode = 1; /* PS2 */
2247 /* Not stdin: script file, sourced file, etc */
2248 do ch = fgetc(i->file); while (ch == '\0');
2253 static inline int fgetc_interactive(struct in_str *i)
2256 do ch = fgetc(i->file); while (ch == '\0');
2259 #endif /* INTERACTIVE */
2261 static int FAST_FUNC file_get(struct in_str *i)
2265 #if ENABLE_FEATURE_EDITING
2266 /* This can be stdin, check line editing char[] buffer */
2267 if (i->p && *i->p != '\0') {
2268 ch = (unsigned char)*i->p++;
2272 /* peek_buf[] is an int array, not char. Can contain EOF. */
2273 ch = i->peek_buf[0];
2275 int ch2 = i->peek_buf[1];
2276 i->peek_buf[0] = ch2;
2277 if (ch2 == 0) /* very likely, avoid redundant write */
2283 ch = fgetc_interactive(i);
2285 debug_printf("file_get: got '%c' %d\n", ch, ch);
2290 static int FAST_FUNC file_peek(struct in_str *i)
2294 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2295 /* This can be stdin, check line editing char[] buffer */
2296 if (i->p && *i->p != '\0')
2297 return (unsigned char)*i->p;
2299 /* peek_buf[] is an int array, not char. Can contain EOF. */
2300 ch = i->peek_buf[0];
2304 /* Need to get a new char */
2305 ch = fgetc_interactive(i);
2306 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2308 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2309 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2315 i->peek_buf[0] = ch;
2316 /*i->peek_buf[1] = 0; - already is */
2320 static int FAST_FUNC static_get(struct in_str *i)
2322 int ch = (unsigned char)*i->p;
2331 static int FAST_FUNC static_peek(struct in_str *i)
2333 /* Doesn't report EOF on NUL. None of the callers care. */
2334 return (unsigned char)*i->p;
2337 /* Only ever called if i_peek() was called, and did not return EOF.
2338 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2339 * not end-of-line. Therefore we never need to read a new editing line here.
2341 static int i_peek2(struct in_str *i)
2345 /* There are two cases when i->p[] buffer exists.
2346 * (1) it's a string in_str.
2347 * (2) It's a file, and we have a saved line editing buffer.
2348 * In both cases, we know that i->p[0] exists and not NUL, and
2349 * the peek2 result is in i->p[1].
2352 return (unsigned char)i->p[1];
2354 /* Now we know it is a file-based in_str. */
2356 /* peek_buf[] is an int array, not char. Can contain EOF. */
2357 /* Is there 2nd char? */
2358 ch = i->peek_buf[1];
2360 /* We did not read it yet, get it now */
2361 do ch = fgetc(i->file); while (ch == '\0');
2362 i->peek_buf[1] = ch;
2365 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2369 static void setup_file_in_str(struct in_str *i, FILE *f)
2371 memset(i, 0, sizeof(*i));
2373 i->peek = file_peek;
2374 /* i->promptmode = 0; - PS1 (memset did it) */
2379 static void setup_string_in_str(struct in_str *i, const char *s)
2381 memset(i, 0, sizeof(*i));
2382 i->get = static_get;
2383 i->peek = static_peek;
2384 /* i->promptmode = 0; - PS1 (memset did it) */
2392 #define B_CHUNK (32 * sizeof(char*))
2394 static void o_reset_to_empty_unquoted(o_string *o)
2397 o->has_quoted_part = 0;
2402 static void o_free(o_string *o)
2405 memset(o, 0, sizeof(*o));
2408 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2413 static void o_grow_by(o_string *o, int len)
2415 if (o->length + len > o->maxlen) {
2416 o->maxlen += (2 * len) | (B_CHUNK-1);
2417 o->data = xrealloc(o->data, 1 + o->maxlen);
2421 static void o_addchr(o_string *o, int ch)
2423 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2424 if (o->length < o->maxlen) {
2425 /* likely. avoid o_grow_by() call */
2427 o->data[o->length] = ch;
2429 o->data[o->length] = '\0';
2437 /* Valid only if we know o_string is not empty */
2438 static void o_delchr(o_string *o)
2441 o->data[o->length] = '\0';
2445 static void o_addblock(o_string *o, const char *str, int len)
2448 memcpy(&o->data[o->length], str, len);
2450 o->data[o->length] = '\0';
2453 static void o_addstr(o_string *o, const char *str)
2455 o_addblock(o, str, strlen(str));
2459 static void nommu_addchr(o_string *o, int ch)
2465 # define nommu_addchr(o, str) ((void)0)
2468 static void o_addstr_with_NUL(o_string *o, const char *str)
2470 o_addblock(o, str, strlen(str) + 1);
2474 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2475 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2476 * Apparently, on unquoted $v bash still does globbing
2477 * ("v='*.txt'; echo $v" prints all .txt files),
2478 * but NOT brace expansion! Thus, there should be TWO independent
2479 * quoting mechanisms on $v expansion side: one protects
2480 * $v from brace expansion, and other additionally protects "$v" against globbing.
2481 * We have only second one.
2484 #if ENABLE_HUSH_BRACE_EXPANSION
2485 # define MAYBE_BRACES "{}"
2487 # define MAYBE_BRACES ""
2490 /* My analysis of quoting semantics tells me that state information
2491 * is associated with a destination, not a source.
2493 static void o_addqchr(o_string *o, int ch)
2496 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2501 o->data[o->length] = '\\';
2504 o->data[o->length] = ch;
2506 o->data[o->length] = '\0';
2509 static void o_addQchr(o_string *o, int ch)
2512 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2513 && strchr("*?[\\" MAYBE_BRACES, ch)
2516 o->data[o->length] = '\\';
2520 o->data[o->length] = ch;
2522 o->data[o->length] = '\0';
2525 static void o_addqblock(o_string *o, const char *str, int len)
2530 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2531 if (ordinary_cnt > len) /* paranoia */
2533 o_addblock(o, str, ordinary_cnt);
2534 if (ordinary_cnt == len)
2535 return; /* NUL is already added by o_addblock */
2536 str += ordinary_cnt;
2537 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2541 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2543 o->data[o->length] = '\\';
2547 o->data[o->length] = ch;
2550 o->data[o->length] = '\0';
2553 static void o_addQblock(o_string *o, const char *str, int len)
2555 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2556 o_addblock(o, str, len);
2559 o_addqblock(o, str, len);
2562 static void o_addQstr(o_string *o, const char *str)
2564 o_addQblock(o, str, strlen(str));
2567 /* A special kind of o_string for $VAR and `cmd` expansion.
2568 * It contains char* list[] at the beginning, which is grown in 16 element
2569 * increments. Actual string data starts at the next multiple of 16 * (char*).
2570 * list[i] contains an INDEX (int!) into this string data.
2571 * It means that if list[] needs to grow, data needs to be moved higher up
2572 * but list[i]'s need not be modified.
2573 * NB: remembering how many list[i]'s you have there is crucial.
2574 * o_finalize_list() operation post-processes this structure - calculates
2575 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2577 #if DEBUG_EXPAND || DEBUG_GLOB
2578 static void debug_print_list(const char *prefix, o_string *o, int n)
2580 char **list = (char**)o->data;
2581 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2585 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2586 prefix, list, n, string_start, o->length, o->maxlen,
2587 !!(o->o_expflags & EXP_FLAG_GLOB),
2589 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2592 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2593 o->data + (int)(uintptr_t)list[i] + string_start,
2594 o->data + (int)(uintptr_t)list[i] + string_start);
2598 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2600 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2604 # define debug_print_list(prefix, o, n) ((void)0)
2607 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2608 * in list[n] so that it points past last stored byte so far.
2609 * It returns n+1. */
2610 static int o_save_ptr_helper(o_string *o, int n)
2612 char **list = (char**)o->data;
2616 if (!o->has_empty_slot) {
2617 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2618 string_len = o->length - string_start;
2619 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2620 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2621 /* list[n] points to string_start, make space for 16 more pointers */
2622 o->maxlen += 0x10 * sizeof(list[0]);
2623 o->data = xrealloc(o->data, o->maxlen + 1);
2624 list = (char**)o->data;
2625 memmove(list + n + 0x10, list + n, string_len);
2626 o->length += 0x10 * sizeof(list[0]);
2628 debug_printf_list("list[%d]=%d string_start=%d\n",
2629 n, string_len, string_start);
2632 /* We have empty slot at list[n], reuse without growth */
2633 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2634 string_len = o->length - string_start;
2635 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2636 n, string_len, string_start);
2637 o->has_empty_slot = 0;
2639 o->has_quoted_part = 0;
2640 list[n] = (char*)(uintptr_t)string_len;
2644 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2645 static int o_get_last_ptr(o_string *o, int n)
2647 char **list = (char**)o->data;
2648 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2650 return ((int)(uintptr_t)list[n-1]) + string_start;
2653 #if ENABLE_HUSH_BRACE_EXPANSION
2654 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2655 * first, it processes even {a} (no commas), second,
2656 * I didn't manage to make it return strings when they don't match
2657 * existing files. Need to re-implement it.
2661 static int glob_needed(const char *s)
2670 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2676 /* Return pointer to next closing brace or to comma */
2677 static const char *next_brace_sub(const char *cp)
2681 while (*cp != '\0') {
2688 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2694 return *cp != '\0' ? cp : NULL;
2696 /* Recursive brace globber. Note: may garble pattern[]. */
2697 static int glob_brace(char *pattern, o_string *o, int n)
2699 char *new_pattern_buf;
2706 debug_printf_glob("glob_brace('%s')\n", pattern);
2712 if (*begin == '{') {
2713 /* Find the first sub-pattern and at the same time
2714 * find the rest after the closing brace */
2715 next = next_brace_sub(begin);
2717 /* An illegal expression */
2721 /* "{abc}" with no commas - illegal
2722 * brace expr, disregard and skip it */
2728 if (*begin == '\\' && begin[1] != '\0')
2732 debug_printf_glob("begin:%s\n", begin);
2733 debug_printf_glob("next:%s\n", next);
2735 /* Now find the end of the whole brace expression */
2737 while (*rest != '}') {
2738 rest = next_brace_sub(rest);
2740 /* An illegal expression */
2743 debug_printf_glob("rest:%s\n", rest);
2745 rest_len = strlen(++rest) + 1;
2747 /* We are sure the brace expression is well-formed */
2749 /* Allocate working buffer large enough for our work */
2750 new_pattern_buf = xmalloc(strlen(pattern));
2752 /* We have a brace expression. BEGIN points to the opening {,
2753 * NEXT points past the terminator of the first element, and REST
2754 * points past the final }. We will accumulate result names from
2755 * recursive runs for each brace alternative in the buffer using
2760 /* Construct the new glob expression */
2763 mempcpy(new_pattern_buf,
2764 /* We know the prefix for all sub-patterns */
2765 pattern, begin - pattern),
2769 /* Note: glob_brace() may garble new_pattern_buf[].
2770 * That's why we re-copy prefix every time (1st memcpy above).
2772 n = glob_brace(new_pattern_buf, o, n);
2774 /* We saw the last entry */
2778 next = next_brace_sub(next);
2780 free(new_pattern_buf);
2788 memset(&globdata, 0, sizeof(globdata));
2789 gr = glob(pattern, 0, NULL, &globdata);
2790 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2792 if (gr == GLOB_NOMATCH) {
2793 globfree(&globdata);
2794 /* NB: garbles parameter */
2795 unbackslash(pattern);
2796 o_addstr_with_NUL(o, pattern);
2797 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2798 return o_save_ptr_helper(o, n);
2800 if (gr == GLOB_NOSPACE)
2801 bb_error_msg_and_die(bb_msg_memory_exhausted);
2802 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2803 * but we didn't specify it. Paranoia again. */
2804 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2806 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2807 char **argv = globdata.gl_pathv;
2809 o_addstr_with_NUL(o, *argv);
2810 n = o_save_ptr_helper(o, n);
2816 globfree(&globdata);
2820 /* Performs globbing on last list[],
2821 * saving each result as a new list[].
2823 static int perform_glob(o_string *o, int n)
2825 char *pattern, *copy;
2827 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2829 return o_save_ptr_helper(o, n);
2830 pattern = o->data + o_get_last_ptr(o, n);
2831 debug_printf_glob("glob pattern '%s'\n", pattern);
2832 if (!glob_needed(pattern)) {
2833 /* unbackslash last string in o in place, fix length */
2834 o->length = unbackslash(pattern) - o->data;
2835 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2836 return o_save_ptr_helper(o, n);
2839 copy = xstrdup(pattern);
2840 /* "forget" pattern in o */
2841 o->length = pattern - o->data;
2842 n = glob_brace(copy, o, n);
2845 debug_print_list("perform_glob returning", o, n);
2849 #else /* !HUSH_BRACE_EXPANSION */
2852 static int glob_needed(const char *s)
2861 if (*s == '*' || *s == '[' || *s == '?')
2867 /* Performs globbing on last list[],
2868 * saving each result as a new list[].
2870 static int perform_glob(o_string *o, int n)
2876 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2878 return o_save_ptr_helper(o, n);
2879 pattern = o->data + o_get_last_ptr(o, n);
2880 debug_printf_glob("glob pattern '%s'\n", pattern);
2881 if (!glob_needed(pattern)) {
2883 /* unbackslash last string in o in place, fix length */
2884 o->length = unbackslash(pattern) - o->data;
2885 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2886 return o_save_ptr_helper(o, n);
2889 memset(&globdata, 0, sizeof(globdata));
2890 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2891 * If we glob "*.\*" and don't find anything, we need
2892 * to fall back to using literal "*.*", but GLOB_NOCHECK
2893 * will return "*.\*"!
2895 gr = glob(pattern, 0, NULL, &globdata);
2896 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2898 if (gr == GLOB_NOMATCH) {
2899 globfree(&globdata);
2902 if (gr == GLOB_NOSPACE)
2903 bb_error_msg_and_die(bb_msg_memory_exhausted);
2904 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2905 * but we didn't specify it. Paranoia again. */
2906 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2908 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2909 char **argv = globdata.gl_pathv;
2910 /* "forget" pattern in o */
2911 o->length = pattern - o->data;
2913 o_addstr_with_NUL(o, *argv);
2914 n = o_save_ptr_helper(o, n);
2920 globfree(&globdata);
2922 debug_print_list("perform_glob returning", o, n);
2926 #endif /* !HUSH_BRACE_EXPANSION */
2928 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2929 * Otherwise, just finish current list[] and start new */
2930 static int o_save_ptr(o_string *o, int n)
2932 if (o->o_expflags & EXP_FLAG_GLOB) {
2933 /* If o->has_empty_slot, list[n] was already globbed
2934 * (if it was requested back then when it was filled)
2935 * so don't do that again! */
2936 if (!o->has_empty_slot)
2937 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2939 return o_save_ptr_helper(o, n);
2942 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2943 static char **o_finalize_list(o_string *o, int n)
2948 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2950 debug_print_list("finalized", o, n);
2951 debug_printf_expand("finalized n:%d\n", n);
2952 list = (char**)o->data;
2953 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2957 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2962 static void free_pipe_list(struct pipe *pi);
2964 /* Returns pi->next - next pipe in the list */
2965 static struct pipe *free_pipe(struct pipe *pi)
2970 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2971 for (i = 0; i < pi->num_cmds; i++) {
2972 struct command *command;
2973 struct redir_struct *r, *rnext;
2975 command = &pi->cmds[i];
2976 debug_printf_clean(" command %d:\n", i);
2977 if (command->argv) {
2981 for (a = 0, p = command->argv; *p; a++, p++) {
2982 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2985 free_strings(command->argv);
2986 //command->argv = NULL;
2988 /* not "else if": on syntax error, we may have both! */
2989 if (command->group) {
2990 debug_printf_clean(" begin group (cmd_type:%d)\n",
2992 free_pipe_list(command->group);
2993 debug_printf_clean(" end group\n");
2994 //command->group = NULL;
2996 /* else is crucial here.
2997 * If group != NULL, child_func is meaningless */
2998 #if ENABLE_HUSH_FUNCTIONS
2999 else if (command->child_func) {
3000 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3001 command->child_func->parent_cmd = NULL;
3005 free(command->group_as_string);
3006 //command->group_as_string = NULL;
3008 for (r = command->redirects; r; r = rnext) {
3009 debug_printf_clean(" redirect %d%s",
3010 r->rd_fd, redir_table[r->rd_type].descrip);
3011 /* guard against the case >$FOO, where foo is unset or blank */
3012 if (r->rd_filename) {
3013 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3014 free(r->rd_filename);
3015 //r->rd_filename = NULL;
3017 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3021 //command->redirects = NULL;
3023 free(pi->cmds); /* children are an array, they get freed all at once */
3027 //pi->cmdtext = NULL;
3035 static void free_pipe_list(struct pipe *pi)
3039 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3041 debug_printf_clean("pipe followup code %d\n", pi->followup);
3047 /*** Parsing routines ***/
3049 #ifndef debug_print_tree
3050 static void debug_print_tree(struct pipe *pi, int lvl)
3052 static const char *const PIPE[] = {
3058 static const char *RES[] = {
3059 [RES_NONE ] = "NONE" ,
3062 [RES_THEN ] = "THEN" ,
3063 [RES_ELIF ] = "ELIF" ,
3064 [RES_ELSE ] = "ELSE" ,
3067 # if ENABLE_HUSH_LOOPS
3068 [RES_FOR ] = "FOR" ,
3069 [RES_WHILE] = "WHILE",
3070 [RES_UNTIL] = "UNTIL",
3072 [RES_DONE ] = "DONE" ,
3074 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3077 # if ENABLE_HUSH_CASE
3078 [RES_CASE ] = "CASE" ,
3079 [RES_CASE_IN ] = "CASE_IN" ,
3080 [RES_MATCH] = "MATCH",
3081 [RES_CASE_BODY] = "CASE_BODY",
3082 [RES_ESAC ] = "ESAC" ,
3084 [RES_XXXX ] = "XXXX" ,
3085 [RES_SNTX ] = "SNTX" ,
3087 static const char *const CMDTYPE[] = {
3091 # if ENABLE_HUSH_FUNCTIONS
3100 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3101 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3103 while (prn < pi->num_cmds) {
3104 struct command *command = &pi->cmds[prn];
3105 char **argv = command->argv;
3107 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3109 command->assignment_cnt);
3110 if (command->group) {
3111 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3112 CMDTYPE[command->cmd_type],
3115 , " group_as_string:", command->group_as_string
3120 debug_print_tree(command->group, lvl+1);
3124 if (argv) while (*argv) {
3125 fdprintf(2, " '%s'", *argv);
3135 #endif /* debug_print_tree */
3137 static struct pipe *new_pipe(void)
3140 pi = xzalloc(sizeof(struct pipe));
3141 /*pi->followup = 0; - deliberately invalid value */
3142 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3146 /* Command (member of a pipe) is complete, or we start a new pipe
3147 * if ctx->command is NULL.
3148 * No errors possible here.
3150 static int done_command(struct parse_context *ctx)
3152 /* The command is really already in the pipe structure, so
3153 * advance the pipe counter and make a new, null command. */
3154 struct pipe *pi = ctx->pipe;
3155 struct command *command = ctx->command;
3157 #if 0 /* Instead we emit error message at run time */
3158 if (ctx->pending_redirect) {
3159 /* For example, "cmd >" (no filename to redirect to) */
3160 die_if_script("syntax error: %s", "invalid redirect");
3161 ctx->pending_redirect = NULL;
3166 if (IS_NULL_CMD(command)) {
3167 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3171 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3172 //debug_print_tree(ctx->list_head, 20);
3174 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3177 /* Only real trickiness here is that the uncommitted
3178 * command structure is not counted in pi->num_cmds. */
3179 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3180 ctx->command = command = &pi->cmds[pi->num_cmds];
3182 memset(command, 0, sizeof(*command));
3183 return pi->num_cmds; /* used only for 0/nonzero check */
3186 static void done_pipe(struct parse_context *ctx, pipe_style type)
3190 debug_printf_parse("done_pipe entered, followup %d\n", type);
3191 /* Close previous command */
3192 not_null = done_command(ctx);
3193 ctx->pipe->followup = type;
3195 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3196 ctx->ctx_inverted = 0;
3197 ctx->pipe->res_word = ctx->ctx_res_w;
3200 /* Without this check, even just <enter> on command line generates
3201 * tree of three NOPs (!). Which is harmless but annoying.
3202 * IOW: it is safe to do it unconditionally. */
3205 || ctx->ctx_res_w == RES_FI
3207 #if ENABLE_HUSH_LOOPS
3208 || ctx->ctx_res_w == RES_DONE
3209 || ctx->ctx_res_w == RES_FOR
3210 || ctx->ctx_res_w == RES_IN
3212 #if ENABLE_HUSH_CASE
3213 || ctx->ctx_res_w == RES_ESAC
3217 debug_printf_parse("done_pipe: adding new pipe: "
3218 "not_null:%d ctx->ctx_res_w:%d\n",
3219 not_null, ctx->ctx_res_w);
3221 ctx->pipe->next = new_p;
3223 /* RES_THEN, RES_DO etc are "sticky" -
3224 * they remain set for pipes inside if/while.
3225 * This is used to control execution.
3226 * RES_FOR and RES_IN are NOT sticky (needed to support
3227 * cases where variable or value happens to match a keyword):
3229 #if ENABLE_HUSH_LOOPS
3230 if (ctx->ctx_res_w == RES_FOR
3231 || ctx->ctx_res_w == RES_IN)
3232 ctx->ctx_res_w = RES_NONE;
3234 #if ENABLE_HUSH_CASE
3235 if (ctx->ctx_res_w == RES_MATCH)
3236 ctx->ctx_res_w = RES_CASE_BODY;
3237 if (ctx->ctx_res_w == RES_CASE)
3238 ctx->ctx_res_w = RES_CASE_IN;
3240 ctx->command = NULL; /* trick done_command below */
3241 /* Create the memory for command, roughly:
3242 * ctx->pipe->cmds = new struct command;
3243 * ctx->command = &ctx->pipe->cmds[0];
3246 //debug_print_tree(ctx->list_head, 10);
3248 debug_printf_parse("done_pipe return\n");
3251 static void initialize_context(struct parse_context *ctx)
3253 memset(ctx, 0, sizeof(*ctx));
3254 ctx->pipe = ctx->list_head = new_pipe();
3255 /* Create the memory for command, roughly:
3256 * ctx->pipe->cmds = new struct command;
3257 * ctx->command = &ctx->pipe->cmds[0];
3262 /* If a reserved word is found and processed, parse context is modified
3263 * and 1 is returned.
3266 struct reserved_combo {
3269 unsigned char assignment_flag;
3273 FLAG_END = (1 << RES_NONE ),
3275 FLAG_IF = (1 << RES_IF ),
3276 FLAG_THEN = (1 << RES_THEN ),
3277 FLAG_ELIF = (1 << RES_ELIF ),
3278 FLAG_ELSE = (1 << RES_ELSE ),
3279 FLAG_FI = (1 << RES_FI ),
3281 # if ENABLE_HUSH_LOOPS
3282 FLAG_FOR = (1 << RES_FOR ),
3283 FLAG_WHILE = (1 << RES_WHILE),
3284 FLAG_UNTIL = (1 << RES_UNTIL),
3285 FLAG_DO = (1 << RES_DO ),
3286 FLAG_DONE = (1 << RES_DONE ),
3287 FLAG_IN = (1 << RES_IN ),
3289 # if ENABLE_HUSH_CASE
3290 FLAG_MATCH = (1 << RES_MATCH),
3291 FLAG_ESAC = (1 << RES_ESAC ),
3293 FLAG_START = (1 << RES_XXXX ),
3296 static const struct reserved_combo* match_reserved_word(o_string *word)
3298 /* Mostly a list of accepted follow-up reserved words.
3299 * FLAG_END means we are done with the sequence, and are ready
3300 * to turn the compound list into a command.
3301 * FLAG_START means the word must start a new compound list.
3303 static const struct reserved_combo reserved_list[] = {
3305 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3306 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3307 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3308 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3309 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3310 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3312 # if ENABLE_HUSH_LOOPS
3313 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3314 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3315 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3316 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3317 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3318 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3320 # if ENABLE_HUSH_CASE
3321 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3322 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3325 const struct reserved_combo *r;
3327 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3328 if (strcmp(word->data, r->literal) == 0)
3333 /* Return 0: not a keyword, 1: keyword
3335 static int reserved_word(o_string *word, struct parse_context *ctx)
3337 # if ENABLE_HUSH_CASE
3338 static const struct reserved_combo reserved_match = {
3339 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3342 const struct reserved_combo *r;
3344 if (word->has_quoted_part)
3346 r = match_reserved_word(word);
3350 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3351 # if ENABLE_HUSH_CASE
3352 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3353 /* "case word IN ..." - IN part starts first MATCH part */
3354 r = &reserved_match;
3357 if (r->flag == 0) { /* '!' */
3358 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3359 syntax_error("! ! command");
3360 ctx->ctx_res_w = RES_SNTX;
3362 ctx->ctx_inverted = 1;
3365 if (r->flag & FLAG_START) {
3366 struct parse_context *old;
3368 old = xmalloc(sizeof(*old));
3369 debug_printf_parse("push stack %p\n", old);
3370 *old = *ctx; /* physical copy */
3371 initialize_context(ctx);
3373 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3374 syntax_error_at(word->data);
3375 ctx->ctx_res_w = RES_SNTX;
3378 /* "{...} fi" is ok. "{...} if" is not
3380 * if { echo foo; } then { echo bar; } fi */
3381 if (ctx->command->group)
3382 done_pipe(ctx, PIPE_SEQ);
3385 ctx->ctx_res_w = r->res;
3386 ctx->old_flag = r->flag;
3387 word->o_assignment = r->assignment_flag;
3388 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3390 if (ctx->old_flag & FLAG_END) {
3391 struct parse_context *old;
3393 done_pipe(ctx, PIPE_SEQ);
3394 debug_printf_parse("pop stack %p\n", ctx->stack);
3396 old->command->group = ctx->list_head;
3397 old->command->cmd_type = CMD_NORMAL;
3399 /* At this point, the compound command's string is in
3400 * ctx->as_string... except for the leading keyword!
3401 * Consider this example: "echo a | if true; then echo a; fi"
3402 * ctx->as_string will contain "true; then echo a; fi",
3403 * with "if " remaining in old->as_string!
3407 int len = old->as_string.length;
3408 /* Concatenate halves */
3409 o_addstr(&old->as_string, ctx->as_string.data);
3410 o_free_unsafe(&ctx->as_string);
3411 /* Find where leading keyword starts in first half */
3412 str = old->as_string.data + len;
3413 if (str > old->as_string.data)
3414 str--; /* skip whitespace after keyword */
3415 while (str > old->as_string.data && isalpha(str[-1]))
3417 /* Ugh, we're done with this horrid hack */
3418 old->command->group_as_string = xstrdup(str);
3419 debug_printf_parse("pop, remembering as:'%s'\n",
3420 old->command->group_as_string);
3423 *ctx = *old; /* physical copy */
3428 #endif /* HAS_KEYWORDS */
3430 /* Word is complete, look at it and update parsing context.
3431 * Normal return is 0. Syntax errors return 1.
3432 * Note: on return, word is reset, but not o_free'd!
3434 static int done_word(o_string *word, struct parse_context *ctx)
3436 struct command *command = ctx->command;
3438 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3439 if (word->length == 0 && !word->has_quoted_part) {
3440 debug_printf_parse("done_word return 0: true null, ignored\n");
3444 if (ctx->pending_redirect) {
3445 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3446 * only if run as "bash", not "sh" */
3447 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3449 * ...the word that follows the redirection operator
3450 * shall be subjected to tilde expansion, parameter expansion,
3451 * command substitution, arithmetic expansion, and quote
3452 * removal. Pathname expansion shall not be performed
3453 * on the word by a non-interactive shell; an interactive
3454 * shell may perform it, but shall do so only when
3455 * the expansion would result in one word."
3457 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3458 /* Cater for >\file case:
3459 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3460 * Same with heredocs:
3461 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3463 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3464 unbackslash(ctx->pending_redirect->rd_filename);
3465 /* Is it <<"HEREDOC"? */
3466 if (word->has_quoted_part) {
3467 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3470 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3471 ctx->pending_redirect = NULL;
3474 # if ENABLE_HUSH_CASE
3475 if (ctx->ctx_dsemicolon
3476 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3478 /* already done when ctx_dsemicolon was set to 1: */
3479 /* ctx->ctx_res_w = RES_MATCH; */
3480 ctx->ctx_dsemicolon = 0;
3483 if (!command->argv /* if it's the first word... */
3484 # if ENABLE_HUSH_LOOPS
3485 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3486 && ctx->ctx_res_w != RES_IN
3488 # if ENABLE_HUSH_CASE
3489 && ctx->ctx_res_w != RES_CASE
3492 int reserved = reserved_word(word, ctx);
3493 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3495 o_reset_to_empty_unquoted(word);
3496 debug_printf_parse("done_word return %d\n",
3497 (ctx->ctx_res_w == RES_SNTX));
3498 return (ctx->ctx_res_w == RES_SNTX);
3500 # if ENABLE_HUSH_BASH_COMPAT
3501 if (strcmp(word->data, "[[") == 0) {
3502 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3508 if (command->group) {
3509 /* "{ echo foo; } echo bar" - bad */
3510 syntax_error_at(word->data);
3511 debug_printf_parse("done_word return 1: syntax error, "
3512 "groups and arglists don't mix\n");
3516 /* If this word wasn't an assignment, next ones definitely
3517 * can't be assignments. Even if they look like ones. */
3518 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3519 && word->o_assignment != WORD_IS_KEYWORD
3521 word->o_assignment = NOT_ASSIGNMENT;
3523 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3524 command->assignment_cnt++;
3525 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3527 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3528 word->o_assignment = MAYBE_ASSIGNMENT;
3530 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3532 if (word->has_quoted_part
3533 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3534 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3535 /* (otherwise it's known to be not empty and is already safe) */
3537 /* exclude "$@" - it can expand to no word despite "" */
3538 char *p = word->data;
3539 while (p[0] == SPECIAL_VAR_SYMBOL
3540 && (p[1] & 0x7f) == '@'
3541 && p[2] == SPECIAL_VAR_SYMBOL
3546 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3547 debug_print_strings("word appended to argv", command->argv);
3550 #if ENABLE_HUSH_LOOPS
3551 if (ctx->ctx_res_w == RES_FOR) {
3552 if (word->has_quoted_part
3553 || !is_well_formed_var_name(command->argv[0], '\0')
3555 /* bash says just "not a valid identifier" */
3556 syntax_error("not a valid identifier in for");
3559 /* Force FOR to have just one word (variable name) */
3560 /* NB: basically, this makes hush see "for v in ..."
3561 * syntax as if it is "for v; in ...". FOR and IN become
3562 * two pipe structs in parse tree. */
3563 done_pipe(ctx, PIPE_SEQ);
3566 #if ENABLE_HUSH_CASE
3567 /* Force CASE to have just one word */
3568 if (ctx->ctx_res_w == RES_CASE) {
3569 done_pipe(ctx, PIPE_SEQ);
3573 o_reset_to_empty_unquoted(word);
3575 debug_printf_parse("done_word return 0\n");
3580 /* Peek ahead in the input to find out if we have a "&n" construct,
3581 * as in "2>&1", that represents duplicating a file descriptor.
3583 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3584 * REDIRFD_SYNTAX_ERR if syntax error,
3585 * REDIRFD_TO_FILE if no & was seen,
3586 * or the number found.
3589 #define parse_redir_right_fd(as_string, input) \
3590 parse_redir_right_fd(input)
3592 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3598 return REDIRFD_TO_FILE;
3600 ch = i_getch(input); /* get the & */
3601 nommu_addchr(as_string, ch);
3604 ch = i_getch(input);
3605 nommu_addchr(as_string, ch);
3606 return REDIRFD_CLOSE;
3610 while (ch != EOF && isdigit(ch)) {
3611 d = d*10 + (ch-'0');
3613 ch = i_getch(input);
3614 nommu_addchr(as_string, ch);
3619 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3621 bb_error_msg("ambiguous redirect");
3622 return REDIRFD_SYNTAX_ERR;
3625 /* Return code is 0 normal, 1 if a syntax error is detected
3627 static int parse_redirect(struct parse_context *ctx,
3630 struct in_str *input)
3632 struct command *command = ctx->command;
3633 struct redir_struct *redir;
3634 struct redir_struct **redirp;
3637 dup_num = REDIRFD_TO_FILE;
3638 if (style != REDIRECT_HEREDOC) {
3639 /* Check for a '>&1' type redirect */
3640 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3641 if (dup_num == REDIRFD_SYNTAX_ERR)
3644 int ch = i_peek(input);
3645 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3646 if (dup_num) { /* <<-... */
3647 ch = i_getch(input);
3648 nommu_addchr(&ctx->as_string, ch);
3653 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3654 int ch = i_peek(input);
3656 /* >|FILE redirect ("clobbering" >).
3657 * Since we do not support "set -o noclobber" yet,
3658 * >| and > are the same for now. Just eat |.
3660 ch = i_getch(input);
3661 nommu_addchr(&ctx->as_string, ch);
3665 /* Create a new redir_struct and append it to the linked list */
3666 redirp = &command->redirects;
3667 while ((redir = *redirp) != NULL) {
3668 redirp = &(redir->next);
3670 *redirp = redir = xzalloc(sizeof(*redir));
3671 /* redir->next = NULL; */
3672 /* redir->rd_filename = NULL; */
3673 redir->rd_type = style;
3674 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3676 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3677 redir_table[style].descrip);
3679 redir->rd_dup = dup_num;
3680 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3681 /* Erik had a check here that the file descriptor in question
3682 * is legit; I postpone that to "run time"
3683 * A "-" representation of "close me" shows up as a -3 here */
3684 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3685 redir->rd_fd, redir->rd_dup);
3687 #if 0 /* Instead we emit error message at run time */
3688 if (ctx->pending_redirect) {
3689 /* For example, "cmd > <file" */
3690 die_if_script("syntax error: %s", "invalid redirect");
3693 /* Set ctx->pending_redirect, so we know what to do at the
3694 * end of the next parsed word. */
3695 ctx->pending_redirect = redir;
3700 /* If a redirect is immediately preceded by a number, that number is
3701 * supposed to tell which file descriptor to redirect. This routine
3702 * looks for such preceding numbers. In an ideal world this routine
3703 * needs to handle all the following classes of redirects...
3704 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3705 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3706 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3707 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3709 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3711 * ... If n is quoted, the number shall not be recognized as part of
3712 * the redirection expression. For example:
3714 * writes the character 2 into file a"
3715 * We are getting it right by setting ->has_quoted_part on any \<char>
3717 * A -1 return means no valid number was found,
3718 * the caller should use the appropriate default for this redirection.
3720 static int redirect_opt_num(o_string *o)
3724 if (o->data == NULL)
3726 num = bb_strtou(o->data, NULL, 10);
3727 if (errno || num < 0)
3729 o_reset_to_empty_unquoted(o);
3734 #define fetch_till_str(as_string, input, word, skip_tabs) \
3735 fetch_till_str(input, word, skip_tabs)
3737 static char *fetch_till_str(o_string *as_string,
3738 struct in_str *input,
3742 o_string heredoc = NULL_O_STRING;
3744 int prev = 0; /* not \ */
3750 ch = i_getch(input);
3752 nommu_addchr(as_string, ch);
3753 if ((ch == '\n' || ch == EOF)
3754 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3756 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3757 heredoc.data[past_EOL] = '\0';
3758 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3759 return heredoc.data;
3761 while (ch == '\n') {
3762 o_addchr(&heredoc, ch);
3765 past_EOL = heredoc.length;
3767 ch = i_getch(input);
3769 nommu_addchr(as_string, ch);
3770 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3774 o_free_unsafe(&heredoc);
3777 o_addchr(&heredoc, ch);
3778 nommu_addchr(as_string, ch);
3779 if (prev == '\\' && ch == '\\')
3780 /* Correctly handle foo\\<eol> (not a line cont.) */
3781 prev = 0; /* not \ */
3787 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3788 * and load them all. There should be exactly heredoc_cnt of them.
3790 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3792 struct pipe *pi = ctx->list_head;
3794 while (pi && heredoc_cnt) {
3796 struct command *cmd = pi->cmds;
3798 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3800 cmd->argv ? cmd->argv[0] : "NONE");
3801 for (i = 0; i < pi->num_cmds; i++) {
3802 struct redir_struct *redir = cmd->redirects;
3804 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3805 i, cmd->argv ? cmd->argv[0] : "NONE");
3807 if (redir->rd_type == REDIRECT_HEREDOC) {
3810 redir->rd_type = REDIRECT_HEREDOC2;
3811 /* redir->rd_dup is (ab)used to indicate <<- */
3812 p = fetch_till_str(&ctx->as_string, input,
3813 redir->rd_filename, redir->rd_dup);
3815 syntax_error("unexpected EOF in here document");
3818 free(redir->rd_filename);
3819 redir->rd_filename = p;
3822 redir = redir->next;
3829 /* Should be 0. If it isn't, it's a parse error */
3831 bb_error_msg_and_die("heredoc BUG 2");
3837 static int run_list(struct pipe *pi);
3839 #define parse_stream(pstring, input, end_trigger) \
3840 parse_stream(input, end_trigger)
3842 static struct pipe *parse_stream(char **pstring,
3843 struct in_str *input,
3847 #if !ENABLE_HUSH_FUNCTIONS
3848 #define parse_group(dest, ctx, input, ch) \
3849 parse_group(ctx, input, ch)
3851 static int parse_group(o_string *dest, struct parse_context *ctx,
3852 struct in_str *input, int ch)
3854 /* dest contains characters seen prior to ( or {.
3855 * Typically it's empty, but for function defs,
3856 * it contains function name (without '()'). */
3857 struct pipe *pipe_list;
3859 struct command *command = ctx->command;
3861 debug_printf_parse("parse_group entered\n");
3862 #if ENABLE_HUSH_FUNCTIONS
3863 if (ch == '(' && !dest->has_quoted_part) {
3865 if (done_word(dest, ctx))
3868 goto skip; /* (... */
3869 if (command->argv[1]) { /* word word ... (... */
3870 syntax_error_unexpected_ch('(');
3873 /* it is "word(..." or "word (..." */
3875 ch = i_getch(input);
3876 while (ch == ' ' || ch == '\t');
3878 syntax_error_unexpected_ch(ch);
3881 nommu_addchr(&ctx->as_string, ch);
3883 ch = i_getch(input);
3884 while (ch == ' ' || ch == '\t' || ch == '\n');
3886 syntax_error_unexpected_ch(ch);
3889 nommu_addchr(&ctx->as_string, ch);
3890 command->cmd_type = CMD_FUNCDEF;
3895 #if 0 /* Prevented by caller */
3896 if (command->argv /* word [word]{... */
3897 || dest->length /* word{... */
3898 || dest->has_quoted_part /* ""{... */
3901 debug_printf_parse("parse_group return 1: "
3902 "syntax error, groups and arglists don't mix\n");
3907 #if ENABLE_HUSH_FUNCTIONS
3913 command->cmd_type = CMD_SUBSHELL;
3915 /* bash does not allow "{echo...", requires whitespace */
3916 ch = i_getch(input);
3917 if (ch != ' ' && ch != '\t' && ch != '\n') {
3918 syntax_error_unexpected_ch(ch);
3921 nommu_addchr(&ctx->as_string, ch);
3926 # define as_string NULL
3928 char *as_string = NULL;
3930 pipe_list = parse_stream(&as_string, input, endch);
3933 o_addstr(&ctx->as_string, as_string);
3935 /* empty ()/{} or parse error? */
3936 if (!pipe_list || pipe_list == ERR_PTR) {
3937 /* parse_stream already emitted error msg */
3940 debug_printf_parse("parse_group return 1: "
3941 "parse_stream returned %p\n", pipe_list);
3944 command->group = pipe_list;
3946 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3947 command->group_as_string = as_string;
3948 debug_printf_parse("end of group, remembering as:'%s'\n",
3949 command->group_as_string);
3953 debug_printf_parse("parse_group return 0\n");
3955 /* command remains "open", available for possible redirects */
3958 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
3963 ch = i_getch(input);
3966 ch2 = i_peek(input);
3969 /* backslash+newline, skip it */
3974 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
3982 ch2 = i_peek2(input);
3985 /* backslash+newline, skip it */
3991 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3992 /* Subroutines for copying $(...) and `...` things */
3993 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3995 static int add_till_single_quote(o_string *dest, struct in_str *input)
3998 int ch = i_getch(input);
4000 syntax_error_unterm_ch('\'');
4008 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4009 static int add_till_double_quote(o_string *dest, struct in_str *input)
4012 int ch = i_getch(input);
4014 syntax_error_unterm_ch('"');
4019 if (ch == '\\') { /* \x. Copy both chars. */
4021 ch = i_getch(input);
4025 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4030 //if (ch == '$') ...
4033 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4035 * "Within the backquoted style of command substitution, backslash
4036 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4037 * The search for the matching backquote shall be satisfied by the first
4038 * backquote found without a preceding backslash; during this search,
4039 * if a non-escaped backquote is encountered within a shell comment,
4040 * a here-document, an embedded command substitution of the $(command)
4041 * form, or a quoted string, undefined results occur. A single-quoted
4042 * or double-quoted string that begins, but does not end, within the
4043 * "`...`" sequence produces undefined results."
4045 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4047 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4050 int ch = i_getch(input);
4054 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4055 ch = i_getch(input);
4059 && (!in_dquote || ch != '"')
4061 o_addchr(dest, '\\');
4065 syntax_error_unterm_ch('`');
4071 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4072 * quoting and nested ()s.
4073 * "With the $(command) style of command substitution, all characters
4074 * following the open parenthesis to the matching closing parenthesis
4075 * constitute the command. Any valid shell script can be used for command,
4076 * except a script consisting solely of redirections which produces
4077 * unspecified results."
4079 * echo $(echo '(TEST)' BEST) (TEST) BEST
4080 * echo $(echo 'TEST)' BEST) TEST) BEST
4081 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4083 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4084 * can contain arbitrary constructs, just like $(cmd).
4085 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4086 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4088 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4089 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4092 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4093 # if ENABLE_HUSH_BASH_COMPAT
4094 char end_char2 = end_ch >> 8;
4096 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4099 ch = i_getch(input);
4101 syntax_error_unterm_ch(end_ch);
4104 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4107 /* we look for closing )) of $((EXPR)) */
4108 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4109 i_getch(input); /* eat second ')' */
4114 if (ch == '(' || ch == '{') {
4115 ch = (ch == '(' ? ')' : '}');
4116 if (!add_till_closing_bracket(dest, input, ch))
4122 if (!add_till_single_quote(dest, input))
4128 if (!add_till_double_quote(dest, input))
4134 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4140 /* \x. Copy verbatim. Important for \(, \) */
4141 ch = i_getch(input);
4143 syntax_error_unterm_ch(')');
4148 /* "backslash+newline", ignore both */
4149 o_delchr(dest); /* undo insertion of '\' */
4159 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
4161 /* Return code: 0 for OK, 1 for syntax error */
4163 #define parse_dollar(as_string, dest, input, quote_mask) \
4164 parse_dollar(dest, input, quote_mask)
4165 #define as_string NULL
4167 static int parse_dollar(o_string *as_string,
4169 struct in_str *input, unsigned char quote_mask)
4171 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4173 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4175 ch = i_getch(input);
4176 nommu_addchr(as_string, ch);
4178 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4180 debug_printf_parse(": '%c'\n", ch);
4181 o_addchr(dest, ch | quote_mask);
4183 ch = i_peek_and_eat_bkslash_nl(input);
4184 if (!isalnum(ch) && ch != '_') {
4185 /* End of variable name reached */
4188 ch = i_getch(input);
4189 nommu_addchr(as_string, ch);
4191 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4192 } else if (isdigit(ch)) {
4194 ch = i_getch(input);
4195 nommu_addchr(as_string, ch);
4196 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4197 debug_printf_parse(": '%c'\n", ch);
4198 o_addchr(dest, ch | quote_mask);
4199 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4200 } else switch (ch) {
4202 case '!': /* last bg pid */
4203 case '?': /* last exit code */
4204 case '#': /* number of args */
4205 case '*': /* args */
4206 case '@': /* args */
4207 goto make_one_char_var;
4209 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4211 ch = i_getch(input); /* eat '{' */
4212 nommu_addchr(as_string, ch);
4214 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4215 /* It should be ${?}, or ${#var},
4216 * or even ${?+subst} - operator acting on a special variable,
4217 * or the beginning of variable name.
4220 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4223 syntax_error_unterm_str("${name}");
4224 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4227 nommu_addchr(as_string, ch);
4230 /* It's possible to just call add_till_closing_bracket() at this point.
4231 * However, this regresses some of our testsuite cases
4232 * which check invalid constructs like ${%}.
4233 * Oh well... let's check that the var name part is fine... */
4239 debug_printf_parse(": '%c'\n", ch);
4241 ch = i_getch(input);
4242 nommu_addchr(as_string, ch);
4246 if (!isalnum(ch) && ch != '_') {
4248 unsigned char last_ch;
4249 /* handle parameter expansions
4250 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4252 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4253 goto bad_dollar_syntax;
4255 /* Eat everything until closing '}' (or ':') */
4257 if (ENABLE_HUSH_BASH_COMPAT
4259 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4261 /* It's ${var:N[:M]} thing */
4262 end_ch = '}' * 0x100 + ':';
4264 if (ENABLE_HUSH_BASH_COMPAT
4267 /* It's ${var/[/]pattern[/repl]} thing */
4268 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4270 nommu_addchr(as_string, '/');
4273 end_ch = '}' * 0x100 + '/';
4279 #if ENABLE_HUSH_DOLLAR_OPS
4280 last_ch = add_till_closing_bracket(dest, input, end_ch);
4281 if (last_ch == 0) /* error? */
4284 #error Simple code to only allow ${var} is not implemented
4287 o_addstr(as_string, dest->data + pos);
4288 o_addchr(as_string, last_ch);
4291 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4292 /* close the first block: */
4293 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4294 /* while parsing N from ${var:N[:M]}
4295 * or pattern from ${var/[/]pattern[/repl]} */
4296 if ((end_ch & 0xff) == last_ch) {
4297 /* got ':' or '/'- parse the rest */
4302 if (end_ch == '}' * 0x100 + ':') {
4303 /* it's ${var:N} - emulate :999999999 */
4304 o_addstr(dest, "999999999");
4305 } /* else: it's ${var/[/]pattern} */
4310 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4313 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4317 ch = i_getch(input);
4318 nommu_addchr(as_string, ch);
4319 # if ENABLE_SH_MATH_SUPPORT
4320 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4321 ch = i_getch(input);
4322 nommu_addchr(as_string, ch);
4323 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4324 o_addchr(dest, /*quote_mask |*/ '+');
4327 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4328 return 0; /* error */
4330 o_addstr(as_string, dest->data + pos);
4331 o_addchr(as_string, ')');
4332 o_addchr(as_string, ')');
4334 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4338 # if ENABLE_HUSH_TICK
4339 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4340 o_addchr(dest, quote_mask | '`');
4343 if (!add_till_closing_bracket(dest, input, ')'))
4344 return 0; /* error */
4346 o_addstr(as_string, dest->data + pos);
4347 o_addchr(as_string, ')');
4349 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4355 ch = i_getch(input);
4356 nommu_addchr(as_string, ch);
4357 ch = i_peek_and_eat_bkslash_nl(input);
4358 if (isalnum(ch)) { /* it's $_name or $_123 */
4363 /* TODO: $_ and $-: */
4364 /* $_ Shell or shell script name; or last argument of last command
4365 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4366 * but in command's env, set to full pathname used to invoke it */
4367 /* $- Option flags set by set builtin or shell options (-i etc) */
4369 o_addQchr(dest, '$');
4371 debug_printf_parse("parse_dollar return 1 (ok)\n");
4377 # if ENABLE_HUSH_BASH_COMPAT
4378 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4379 encode_string(dest, input, dquote_end, process_bkslash)
4381 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4382 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4383 encode_string(dest, input, dquote_end)
4385 #define as_string NULL
4389 # if ENABLE_HUSH_BASH_COMPAT
4390 /* all parameters are needed, no macro tricks */
4392 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4393 encode_string(as_string, dest, input, dquote_end)
4396 static int encode_string(o_string *as_string,
4398 struct in_str *input,
4400 int process_bkslash)
4402 #if !ENABLE_HUSH_BASH_COMPAT
4403 const int process_bkslash = 1;
4409 ch = i_getch(input);
4411 nommu_addchr(as_string, ch);
4412 if (ch == dquote_end) { /* may be only '"' or EOF */
4413 debug_printf_parse("encode_string return 1 (ok)\n");
4416 /* note: can't move it above ch == dquote_end check! */
4418 syntax_error_unterm_ch('"');
4419 return 0; /* error */
4423 next = i_peek(input);
4425 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4426 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4427 if (process_bkslash && ch == '\\') {
4429 syntax_error("\\<eof>");
4433 * "The backslash retains its special meaning [in "..."]
4434 * only when followed by one of the following characters:
4435 * $, `, ", \, or <newline>. A double quote may be quoted
4436 * within double quotes by preceding it with a backslash."
4437 * NB: in (unquoted) heredoc, above does not apply to ",
4438 * therefore we check for it by "next == dquote_end" cond.
4440 if (next == dquote_end || strchr("$`\\\n", next)) {
4441 ch = i_getch(input); /* eat next */
4443 goto again; /* skip \<newline> */
4444 } /* else: ch remains == '\\', and we double it below: */
4445 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4446 nommu_addchr(as_string, ch);
4450 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4451 debug_printf_parse("encode_string return 0: "
4452 "parse_dollar returned 0 (error)\n");
4457 #if ENABLE_HUSH_TICK
4459 //unsigned pos = dest->length;
4460 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4461 o_addchr(dest, 0x80 | '`');
4462 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4463 return 0; /* error */
4464 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4465 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4469 o_addQchr(dest, ch);
4475 * Scan input until EOF or end_trigger char.
4476 * Return a list of pipes to execute, or NULL on EOF
4477 * or if end_trigger character is met.
4478 * On syntax error, exit if shell is not interactive,
4479 * reset parsing machinery and start parsing anew,
4480 * or return ERR_PTR.
4482 static struct pipe *parse_stream(char **pstring,
4483 struct in_str *input,
4486 struct parse_context ctx;
4487 o_string dest = NULL_O_STRING;
4490 /* Single-quote triggers a bypass of the main loop until its mate is
4491 * found. When recursing, quote state is passed in via dest->o_expflags.
4493 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4494 end_trigger ? end_trigger : 'X');
4497 /* If very first arg is "" or '', dest.data may end up NULL.
4498 * Preventing this: */
4499 o_addchr(&dest, '\0');
4502 /* We used to separate words on $IFS here. This was wrong.
4503 * $IFS is used only for word splitting when $var is expanded,
4504 * here we should use blank chars as separators, not $IFS
4507 if (MAYBE_ASSIGNMENT != 0)
4508 dest.o_assignment = MAYBE_ASSIGNMENT;
4509 initialize_context(&ctx);
4512 const char *is_blank;
4513 const char *is_special;
4517 redir_type redir_style;
4519 ch = i_getch(input);
4520 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4521 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4526 syntax_error_unterm_str("here document");
4529 /* end_trigger == '}' case errors out earlier,
4530 * checking only ')' */
4531 if (end_trigger == ')') {
4532 syntax_error_unterm_ch('(');
4536 if (done_word(&dest, &ctx)) {
4540 done_pipe(&ctx, PIPE_SEQ);
4542 /* If we got nothing... */
4543 /* (this makes bare "&" cmd a no-op.
4544 * bash says: "syntax error near unexpected token '&'") */
4545 if (pi->num_cmds == 0
4546 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4552 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4554 *pstring = ctx.as_string.data;
4556 o_free_unsafe(&ctx.as_string);
4559 debug_printf_parse("parse_stream return %p\n", pi);
4562 nommu_addchr(&ctx.as_string, ch);
4566 next = i_peek(input);
4568 is_special = "{}<>;&|()#'" /* special outside of "str" */
4569 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4570 /* Are { and } special here? */
4571 if (ctx.command->argv /* word [word]{... - non-special */
4572 || dest.length /* word{... - non-special */
4573 || dest.has_quoted_part /* ""{... - non-special */
4574 || (next != ';' /* }; - special */
4575 && next != ')' /* }) - special */
4576 && next != '&' /* }& and }&& ... - special */
4577 && next != '|' /* }|| ... - special */
4578 && !strchr(defifs, next) /* {word - non-special */
4581 /* They are not special, skip "{}" */
4584 is_special = strchr(is_special, ch);
4585 is_blank = strchr(defifs, ch);
4587 if (!is_special && !is_blank) { /* ordinary char */
4589 o_addQchr(&dest, ch);
4590 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4591 || dest.o_assignment == WORD_IS_KEYWORD)
4593 && is_well_formed_var_name(dest.data, '=')
4595 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4596 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4602 if (done_word(&dest, &ctx)) {
4606 /* Is this a case when newline is simply ignored?
4608 * "cmd | <newline> cmd ..."
4609 * "case ... in <newline> word) ..."
4611 if (IS_NULL_CMD(ctx.command)
4612 && dest.length == 0 && !dest.has_quoted_part
4614 /* This newline can be ignored. But...
4615 * Without check #1, interactive shell
4616 * ignores even bare <newline>,
4617 * and shows the continuation prompt:
4618 * ps1_prompt$ <enter>
4619 * ps2> _ <=== wrong, should be ps1
4620 * Without check #2, "cmd & <newline>"
4621 * is similarly mistreated.
4622 * (BTW, this makes "cmd & cmd"
4623 * and "cmd && cmd" non-orthogonal.
4624 * Really, ask yourself, why
4625 * "cmd && <newline>" doesn't start
4626 * cmd but waits for more input?
4629 struct pipe *pi = ctx.list_head;
4630 if (pi->num_cmds != 0 /* check #1 */
4631 && pi->followup != PIPE_BG /* check #2 */
4636 /* Treat newline as a command separator. */
4637 done_pipe(&ctx, PIPE_SEQ);
4638 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4640 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4645 dest.o_assignment = MAYBE_ASSIGNMENT;
4646 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4648 /* note: if (is_blank) continue;
4649 * will still trigger for us */
4653 /* "cmd}" or "cmd }..." without semicolon or &:
4654 * } is an ordinary char in this case, even inside { cmd; }
4655 * Pathological example: { ""}; } should exec "}" cmd
4658 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4659 || dest.length != 0 /* word} */
4660 || dest.has_quoted_part /* ""} */
4664 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4665 goto skip_end_trigger;
4666 /* else: } does terminate a group */
4669 if (end_trigger && end_trigger == ch
4670 && (ch != ';' || heredoc_cnt == 0)
4671 #if ENABLE_HUSH_CASE
4673 || ctx.ctx_res_w != RES_MATCH
4674 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4679 /* This is technically valid:
4680 * { cat <<HERE; }; echo Ok
4684 * but we don't support this.
4685 * We require heredoc to be in enclosing {}/(),
4688 syntax_error_unterm_str("here document");
4691 if (done_word(&dest, &ctx)) {
4694 done_pipe(&ctx, PIPE_SEQ);
4695 dest.o_assignment = MAYBE_ASSIGNMENT;
4696 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4697 /* Do we sit outside of any if's, loops or case's? */
4699 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4703 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4705 *pstring = ctx.as_string.data;
4707 o_free_unsafe(&ctx.as_string);
4710 debug_printf_parse("parse_stream return %p: "
4711 "end_trigger char found\n",
4713 return ctx.list_head;
4720 /* Catch <, > before deciding whether this word is
4721 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4724 redir_fd = redirect_opt_num(&dest);
4725 if (done_word(&dest, &ctx)) {
4728 redir_style = REDIRECT_OVERWRITE;
4730 redir_style = REDIRECT_APPEND;
4731 ch = i_getch(input);
4732 nommu_addchr(&ctx.as_string, ch);
4735 else if (next == '(') {
4736 syntax_error(">(process) not supported");
4740 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4742 continue; /* back to top of while (1) */
4744 redir_fd = redirect_opt_num(&dest);
4745 if (done_word(&dest, &ctx)) {
4748 redir_style = REDIRECT_INPUT;
4750 redir_style = REDIRECT_HEREDOC;
4752 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4753 ch = i_getch(input);
4754 nommu_addchr(&ctx.as_string, ch);
4755 } else if (next == '>') {
4756 redir_style = REDIRECT_IO;
4757 ch = i_getch(input);
4758 nommu_addchr(&ctx.as_string, ch);
4761 else if (next == '(') {
4762 syntax_error("<(process) not supported");
4766 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4768 continue; /* back to top of while (1) */
4770 if (dest.length == 0 && !dest.has_quoted_part) {
4771 /* skip "#comment" */
4774 if (ch == EOF || ch == '\n')
4777 /* note: we do not add it to &ctx.as_string */
4779 nommu_addchr(&ctx.as_string, '\n');
4780 continue; /* back to top of while (1) */
4785 /* It's "\<newline>" */
4787 /* Remove trailing '\' from ctx.as_string */
4788 ctx.as_string.data[--ctx.as_string.length] = '\0';
4790 ch = i_getch(input); /* eat it */
4791 continue; /* back to top of while (1) */
4796 if (dest.o_assignment == MAYBE_ASSIGNMENT
4797 /* check that we are not in word in "a=1 2>word b=1": */
4798 && !ctx.pending_redirect
4800 /* ch is a special char and thus this word
4801 * cannot be an assignment */
4802 dest.o_assignment = NOT_ASSIGNMENT;
4803 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4806 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4809 case '#': /* non-comment #: "echo a#b" etc */
4810 o_addQchr(&dest, ch);
4814 syntax_error("\\<eof>");
4817 ch = i_getch(input);
4818 /* note: ch != '\n' (that case does not reach this place) */
4819 o_addchr(&dest, '\\');
4820 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4821 o_addchr(&dest, ch);
4822 nommu_addchr(&ctx.as_string, ch);
4823 /* Example: echo Hello \2>file
4824 * we need to know that word 2 is quoted */
4825 dest.has_quoted_part = 1;
4828 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4829 debug_printf_parse("parse_stream parse error: "
4830 "parse_dollar returned 0 (error)\n");
4835 dest.has_quoted_part = 1;
4836 if (next == '\'' && !ctx.pending_redirect) {
4837 insert_empty_quoted_str_marker:
4838 nommu_addchr(&ctx.as_string, next);
4839 i_getch(input); /* eat second ' */
4840 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4841 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4844 ch = i_getch(input);
4846 syntax_error_unterm_ch('\'');
4849 nommu_addchr(&ctx.as_string, ch);
4852 o_addqchr(&dest, ch);
4857 dest.has_quoted_part = 1;
4858 if (next == '"' && !ctx.pending_redirect)
4859 goto insert_empty_quoted_str_marker;
4860 if (dest.o_assignment == NOT_ASSIGNMENT)
4861 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4862 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4864 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4866 #if ENABLE_HUSH_TICK
4868 USE_FOR_NOMMU(unsigned pos;)
4870 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4871 o_addchr(&dest, '`');
4872 USE_FOR_NOMMU(pos = dest.length;)
4873 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4876 o_addstr(&ctx.as_string, dest.data + pos);
4877 o_addchr(&ctx.as_string, '`');
4879 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4880 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4885 #if ENABLE_HUSH_CASE
4888 if (done_word(&dest, &ctx)) {
4891 done_pipe(&ctx, PIPE_SEQ);
4892 #if ENABLE_HUSH_CASE
4893 /* Eat multiple semicolons, detect
4894 * whether it means something special */
4899 ch = i_getch(input);
4900 nommu_addchr(&ctx.as_string, ch);
4901 if (ctx.ctx_res_w == RES_CASE_BODY) {
4902 ctx.ctx_dsemicolon = 1;
4903 ctx.ctx_res_w = RES_MATCH;
4909 /* We just finished a cmd. New one may start
4910 * with an assignment */
4911 dest.o_assignment = MAYBE_ASSIGNMENT;
4912 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4915 if (done_word(&dest, &ctx)) {
4919 ch = i_getch(input);
4920 nommu_addchr(&ctx.as_string, ch);
4921 done_pipe(&ctx, PIPE_AND);
4923 done_pipe(&ctx, PIPE_BG);
4927 if (done_word(&dest, &ctx)) {
4930 #if ENABLE_HUSH_CASE
4931 if (ctx.ctx_res_w == RES_MATCH)
4932 break; /* we are in case's "word | word)" */
4934 if (next == '|') { /* || */
4935 ch = i_getch(input);
4936 nommu_addchr(&ctx.as_string, ch);
4937 done_pipe(&ctx, PIPE_OR);
4939 /* we could pick up a file descriptor choice here
4940 * with redirect_opt_num(), but bash doesn't do it.
4941 * "echo foo 2| cat" yields "foo 2". */
4946 #if ENABLE_HUSH_CASE
4947 /* "case... in [(]word)..." - skip '(' */
4948 if (ctx.ctx_res_w == RES_MATCH
4949 && ctx.command->argv == NULL /* not (word|(... */
4950 && dest.length == 0 /* not word(... */
4951 && dest.has_quoted_part == 0 /* not ""(... */
4957 if (parse_group(&dest, &ctx, input, ch) != 0) {
4962 #if ENABLE_HUSH_CASE
4963 if (ctx.ctx_res_w == RES_MATCH)
4967 /* proper use of this character is caught by end_trigger:
4968 * if we see {, we call parse_group(..., end_trigger='}')
4969 * and it will match } earlier (not here). */
4970 syntax_error_unexpected_ch(ch);
4974 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4980 struct parse_context *pctx;
4981 IF_HAS_KEYWORDS(struct parse_context *p2;)
4983 /* Clean up allocated tree.
4984 * Sample for finding leaks on syntax error recovery path.
4985 * Run it from interactive shell, watch pmap `pidof hush`.
4986 * while if false; then false; fi; do break; fi
4987 * Samples to catch leaks at execution:
4988 * while if (true | {true;}); then echo ok; fi; do break; done
4989 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4993 /* Update pipe/command counts,
4994 * otherwise freeing may miss some */
4995 done_pipe(pctx, PIPE_SEQ);
4996 debug_printf_clean("freeing list %p from ctx %p\n",
4997 pctx->list_head, pctx);
4998 debug_print_tree(pctx->list_head, 0);
4999 free_pipe_list(pctx->list_head);
5000 debug_printf_clean("freed list %p\n", pctx->list_head);
5002 o_free_unsafe(&pctx->as_string);
5004 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5008 IF_HAS_KEYWORDS(pctx = p2;)
5009 } while (HAS_KEYWORDS && pctx);
5012 G.last_exitcode = 1;
5023 /*** Execution routines ***/
5025 /* Expansion can recurse, need forward decls: */
5026 #if !ENABLE_HUSH_BASH_COMPAT
5027 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5028 #define expand_string_to_string(str, do_unbackslash) \
5029 expand_string_to_string(str)
5031 static char *expand_string_to_string(const char *str, int do_unbackslash);
5032 #if ENABLE_HUSH_TICK
5033 static int process_command_subs(o_string *dest, const char *s);
5036 /* expand_strvec_to_strvec() takes a list of strings, expands
5037 * all variable references within and returns a pointer to
5038 * a list of expanded strings, possibly with larger number
5039 * of strings. (Think VAR="a b"; echo $VAR).
5040 * This new list is allocated as a single malloc block.
5041 * NULL-terminated list of char* pointers is at the beginning of it,
5042 * followed by strings themselves.
5043 * Caller can deallocate entire list by single free(list). */
5045 /* A horde of its helpers come first: */
5047 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5049 while (--len >= 0) {
5052 #if ENABLE_HUSH_BRACE_EXPANSION
5053 if (c == '{' || c == '}') {
5054 /* { -> \{, } -> \} */
5056 /* And now we want to add { or } and continue:
5059 * luckily, just falling throught achieves this.
5065 /* \z -> \\\z; \<eol> -> \\<eol> */
5070 o_addchr(o, *str++);
5076 /* Store given string, finalizing the word and starting new one whenever
5077 * we encounter IFS char(s). This is used for expanding variable values.
5078 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5079 * Return in *ended_with_ifs:
5080 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5082 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5084 int last_is_ifs = 0;
5089 if (!*str) /* EOL - do not finalize word */
5091 word_len = strcspn(str, G.ifs);
5093 /* We have WORD_LEN leading non-IFS chars */
5094 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5095 o_addblock(output, str, word_len);
5097 /* Protect backslashes against globbing up :)
5098 * Example: "v='\*'; echo b$v" prints "b\*"
5099 * (and does not try to glob on "*")
5101 o_addblock_duplicate_backslash(output, str, word_len);
5102 /*/ Why can't we do it easier? */
5103 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5104 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5108 if (!*str) /* EOL - do not finalize word */
5112 /* We know str here points to at least one IFS char */
5114 str += strspn(str, G.ifs); /* skip IFS chars */
5115 if (!*str) /* EOL - do not finalize word */
5118 /* Start new word... but not always! */
5119 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5120 if (output->has_quoted_part
5121 /* Case "v=' a'; echo $v":
5122 * here nothing precedes the space in $v expansion,
5123 * therefore we should not finish the word
5124 * (IOW: if there *is* word to finalize, only then do it):
5126 || (n > 0 && output->data[output->length - 1])
5128 o_addchr(output, '\0');
5129 debug_print_list("expand_on_ifs", output, n);
5130 n = o_save_ptr(output, n);
5135 *ended_with_ifs = last_is_ifs;
5136 debug_print_list("expand_on_ifs[1]", output, n);
5140 /* Helper to expand $((...)) and heredoc body. These act as if
5141 * they are in double quotes, with the exception that they are not :).
5142 * Just the rules are similar: "expand only $var and `cmd`"
5144 * Returns malloced string.
5145 * As an optimization, we return NULL if expansion is not needed.
5147 #if !ENABLE_HUSH_BASH_COMPAT
5148 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5149 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5150 encode_then_expand_string(str)
5152 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5155 struct in_str input;
5156 o_string dest = NULL_O_STRING;
5158 if (!strchr(str, '$')
5159 && !strchr(str, '\\')
5160 #if ENABLE_HUSH_TICK
5161 && !strchr(str, '`')
5167 /* We need to expand. Example:
5168 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5170 setup_string_in_str(&input, str);
5171 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5172 //TODO: error check (encode_string returns 0 on error)?
5173 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5174 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5175 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5176 o_free_unsafe(&dest);
5180 #if ENABLE_SH_MATH_SUPPORT
5181 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5183 arith_state_t math_state;
5187 math_state.lookupvar = get_local_var_value;
5188 math_state.setvar = set_local_var_from_halves;
5189 //math_state.endofname = endofname;
5190 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5191 res = arith(&math_state, exp_str ? exp_str : arg);
5194 *errmsg_p = math_state.errmsg;
5195 if (math_state.errmsg)
5196 die_if_script(math_state.errmsg);
5201 #if ENABLE_HUSH_BASH_COMPAT
5202 /* ${var/[/]pattern[/repl]} helpers */
5203 static char *strstr_pattern(char *val, const char *pattern, int *size)
5206 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5207 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5214 /* Optimization: if "*pat" did not match the start of "string",
5215 * we know that "tring", "ring" etc will not match too:
5217 if (pattern[0] == '*')
5222 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5224 char *result = NULL;
5225 unsigned res_len = 0;
5226 unsigned repl_len = strlen(repl);
5230 char *s = strstr_pattern(val, pattern, &size);
5234 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5235 memcpy(result + res_len, val, s - val);
5237 strcpy(result + res_len, repl);
5238 res_len += repl_len;
5239 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5245 if (val[0] && result) {
5246 result = xrealloc(result, res_len + strlen(val) + 1);
5247 strcpy(result + res_len, val);
5248 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5250 debug_printf_varexp("result:'%s'\n", result);
5256 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5258 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5260 const char *val = NULL;
5261 char *to_be_freed = NULL;
5266 char exp_save = exp_save; /* for compiler */
5267 char *exp_saveptr; /* points to expansion operator */
5268 char *exp_word = exp_word; /* for compiler */
5271 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5273 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5275 first_char = arg[0] = arg0 & 0x7f;
5278 if (first_char == '#' /* ${#... */
5279 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5281 /* It must be length operator: ${#var} */
5285 /* Maybe handle parameter expansion */
5286 if (exp_saveptr /* if 2nd char is one of expansion operators */
5287 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5289 /* ${?:0}, ${#[:]%0} etc */
5290 exp_saveptr = var + 1;
5292 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5293 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5295 exp_op = exp_save = *exp_saveptr;
5297 exp_word = exp_saveptr + 1;
5298 if (exp_op == ':') {
5299 exp_op = *exp_word++;
5300 //TODO: try ${var:} and ${var:bogus} in non-bash config
5301 if (ENABLE_HUSH_BASH_COMPAT
5302 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5304 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5309 *exp_saveptr = '\0';
5310 } /* else: it's not an expansion op, but bare ${var} */
5313 /* Look up the variable in question */
5314 if (isdigit(var[0])) {
5315 /* parse_dollar should have vetted var for us */
5316 int n = xatoi_positive(var);
5317 if (n < G.global_argc)
5318 val = G.global_argv[n];
5319 /* else val remains NULL: $N with too big N */
5323 val = utoa(G.root_pid);
5325 case '!': /* bg pid */
5326 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5328 case '?': /* exitcode */
5329 val = utoa(G.last_exitcode);
5331 case '#': /* argc */
5332 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5335 val = get_local_var_value(var);
5339 /* Handle any expansions */
5340 if (exp_op == 'L') {
5341 reinit_unicode_for_hush();
5342 debug_printf_expand("expand: length(%s)=", val);
5343 val = utoa(val ? unicode_strlen(val) : 0);
5344 debug_printf_expand("%s\n", val);
5345 } else if (exp_op) {
5346 if (exp_op == '%' || exp_op == '#') {
5347 /* Standard-mandated substring removal ops:
5348 * ${parameter%word} - remove smallest suffix pattern
5349 * ${parameter%%word} - remove largest suffix pattern
5350 * ${parameter#word} - remove smallest prefix pattern
5351 * ${parameter##word} - remove largest prefix pattern
5353 * Word is expanded to produce a glob pattern.
5354 * Then var's value is matched to it and matching part removed.
5356 if (val && val[0]) {
5360 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5361 if (exp_op == *exp_word) /* ## or %% */
5363 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5365 exp_word = exp_exp_word;
5366 /* HACK ALERT. We depend here on the fact that
5367 * G.global_argv and results of utoa and get_local_var_value
5368 * are actually in writable memory:
5369 * scan_and_match momentarily stores NULs there. */
5371 loc = scan_and_match(t, exp_word, scan_flags);
5372 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5373 // exp_op, t, exp_word, loc);
5375 if (loc) { /* match was found */
5376 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5377 val = loc; /* take right part */
5379 val = to_be_freed = xstrndup(val, loc - val); /* left */
5383 #if ENABLE_HUSH_BASH_COMPAT
5384 else if (exp_op == '/' || exp_op == '\\') {
5385 /* It's ${var/[/]pattern[/repl]} thing.
5386 * Note that in encoded form it has TWO parts:
5387 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5388 * and if // is used, it is encoded as \:
5389 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5391 /* Empty variable always gives nothing: */
5392 // "v=''; echo ${v/*/w}" prints "", not "w"
5393 if (val && val[0]) {
5394 /* pattern uses non-standard expansion.
5395 * repl should be unbackslashed and globbed
5396 * by the usual expansion rules:
5398 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5399 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5400 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5401 * v='a bz'; echo ${v/a*z/\z} prints "z"
5402 * (note that a*z _pattern_ is never globbed!)
5404 char *pattern, *repl, *t;
5405 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5407 pattern = xstrdup(exp_word);
5408 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5409 *p++ = SPECIAL_VAR_SYMBOL;
5411 p = strchr(p, SPECIAL_VAR_SYMBOL);
5413 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5414 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5415 /* HACK ALERT. We depend here on the fact that
5416 * G.global_argv and results of utoa and get_local_var_value
5417 * are actually in writable memory:
5418 * replace_pattern momentarily stores NULs there. */
5420 to_be_freed = replace_pattern(t,
5422 (repl ? repl : exp_word),
5424 if (to_be_freed) /* at least one replace happened */
5431 else if (exp_op == ':') {
5432 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5433 /* It's ${var:N[:M]} bashism.
5434 * Note that in encoded form it has TWO parts:
5435 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5440 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5443 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5444 *p++ = SPECIAL_VAR_SYMBOL;
5446 p = strchr(p, SPECIAL_VAR_SYMBOL);
5448 len = expand_and_evaluate_arith(exp_word, &errmsg);
5451 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5452 if (len >= 0) { /* bash compat: len < 0 is illegal */
5453 if (beg < 0) /* bash compat */
5455 debug_printf_varexp("from val:'%s'\n", val);
5456 if (len == 0 || !val || beg >= strlen(val)) {
5460 /* Paranoia. What if user entered 9999999999999
5461 * which fits in arith_t but not int? */
5464 val = to_be_freed = xstrndup(val + beg, len);
5466 debug_printf_varexp("val:'%s'\n", val);
5470 die_if_script("malformed ${%s:...}", var);
5473 } else { /* one of "-=+?" */
5474 /* Standard-mandated substitution ops:
5475 * ${var?word} - indicate error if unset
5476 * If var is unset, word (or a message indicating it is unset
5477 * if word is null) is written to standard error
5478 * and the shell exits with a non-zero exit status.
5479 * Otherwise, the value of var is substituted.
5480 * ${var-word} - use default value
5481 * If var is unset, word is substituted.
5482 * ${var=word} - assign and use default value
5483 * If var is unset, word is assigned to var.
5484 * In all cases, final value of var is substituted.
5485 * ${var+word} - use alternative value
5486 * If var is unset, null is substituted.
5487 * Otherwise, word is substituted.
5489 * Word is subjected to tilde expansion, parameter expansion,
5490 * command substitution, and arithmetic expansion.
5491 * If word is not needed, it is not expanded.
5493 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5494 * but also treat null var as if it is unset.
5496 int use_word = (!val || ((exp_save == ':') && !val[0]));
5498 use_word = !use_word;
5499 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5500 (exp_save == ':') ? "true" : "false", use_word);
5502 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5504 exp_word = to_be_freed;
5505 if (exp_op == '?') {
5506 /* mimic bash message */
5507 die_if_script("%s: %s",
5509 exp_word[0] ? exp_word : "parameter null or not set"
5511 //TODO: how interactive bash aborts expansion mid-command?
5516 if (exp_op == '=') {
5517 /* ${var=[word]} or ${var:=[word]} */
5518 if (isdigit(var[0]) || var[0] == '#') {
5519 /* mimic bash message */
5520 die_if_script("$%s: cannot assign in this way", var);
5523 char *new_var = xasprintf("%s=%s", var, val);
5524 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5528 } /* one of "-=+?" */
5530 *exp_saveptr = exp_save;
5536 *to_be_freed_pp = to_be_freed;
5540 /* Expand all variable references in given string, adding words to list[]
5541 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5542 * to be filled). This routine is extremely tricky: has to deal with
5543 * variables/parameters with whitespace, $* and $@, and constructs like
5544 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5545 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5547 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5548 * expansion of right-hand side of assignment == 1-element expand.
5550 char cant_be_null = 0; /* only bit 0x80 matters */
5551 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5554 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5555 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5556 debug_print_list("expand_vars_to_list", output, n);
5557 n = o_save_ptr(output, n);
5558 debug_print_list("expand_vars_to_list[0]", output, n);
5560 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5562 char *to_be_freed = NULL;
5563 const char *val = NULL;
5564 #if ENABLE_HUSH_TICK
5565 o_string subst_result = NULL_O_STRING;
5567 #if ENABLE_SH_MATH_SUPPORT
5568 char arith_buf[sizeof(arith_t)*3 + 2];
5572 o_addchr(output, '\0');
5573 n = o_save_ptr(output, n);
5577 o_addblock(output, arg, p - arg);
5578 debug_print_list("expand_vars_to_list[1]", output, n);
5580 p = strchr(p, SPECIAL_VAR_SYMBOL);
5582 /* Fetch special var name (if it is indeed one of them)
5583 * and quote bit, force the bit on if singleword expansion -
5584 * important for not getting v=$@ expand to many words. */
5585 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5587 /* Is this variable quoted and thus expansion can't be null?
5588 * "$@" is special. Even if quoted, it can still
5589 * expand to nothing (not even an empty string),
5590 * thus it is excluded. */
5591 if ((first_ch & 0x7f) != '@')
5592 cant_be_null |= first_ch;
5594 switch (first_ch & 0x7f) {
5595 /* Highest bit in first_ch indicates that var is double-quoted */
5599 if (!G.global_argv[1])
5602 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5603 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5604 while (G.global_argv[i]) {
5605 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5606 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5607 if (G.global_argv[i++][0] && G.global_argv[i]) {
5608 /* this argv[] is not empty and not last:
5609 * put terminating NUL, start new word */
5610 o_addchr(output, '\0');
5611 debug_print_list("expand_vars_to_list[2]", output, n);
5612 n = o_save_ptr(output, n);
5613 debug_print_list("expand_vars_to_list[3]", output, n);
5617 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5618 * and in this case should treat it like '$*' - see 'else...' below */
5619 if (first_ch == ('@'|0x80) /* quoted $@ */
5620 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5623 o_addQstr(output, G.global_argv[i]);
5624 if (++i >= G.global_argc)
5626 o_addchr(output, '\0');
5627 debug_print_list("expand_vars_to_list[4]", output, n);
5628 n = o_save_ptr(output, n);
5630 } else { /* quoted $* (or v="$@" case): add as one word */
5632 o_addQstr(output, G.global_argv[i]);
5633 if (!G.global_argv[++i])
5636 o_addchr(output, G.ifs[0]);
5638 output->has_quoted_part = 1;
5642 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5643 /* "Empty variable", used to make "" etc to not disappear */
5644 output->has_quoted_part = 1;
5646 cant_be_null = 0x80;
5648 #if ENABLE_HUSH_TICK
5649 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5650 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5652 /* Can't just stuff it into output o_string,
5653 * expanded result may need to be globbed
5654 * and $IFS-splitted */
5655 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5656 G.last_exitcode = process_command_subs(&subst_result, arg);
5657 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5658 val = subst_result.data;
5661 #if ENABLE_SH_MATH_SUPPORT
5662 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5665 arg++; /* skip '+' */
5666 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5667 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5668 res = expand_and_evaluate_arith(arg, NULL);
5669 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5670 sprintf(arith_buf, ARITH_FMT, res);
5676 val = expand_one_var(&to_be_freed, arg, &p);
5677 IF_HUSH_TICK(store_val:)
5678 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5679 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5680 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5681 if (val && val[0]) {
5682 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5685 } else { /* quoted $VAR, val will be appended below */
5686 output->has_quoted_part = 1;
5687 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5688 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5691 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5693 if (val && val[0]) {
5694 o_addQstr(output, val);
5698 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5699 * Do the check to avoid writing to a const string. */
5700 if (*p != SPECIAL_VAR_SYMBOL)
5701 *p = SPECIAL_VAR_SYMBOL;
5703 #if ENABLE_HUSH_TICK
5704 o_free(&subst_result);
5707 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5711 o_addchr(output, '\0');
5712 n = o_save_ptr(output, n);
5714 debug_print_list("expand_vars_to_list[a]", output, n);
5715 /* this part is literal, and it was already pre-quoted
5716 * if needed (much earlier), do not use o_addQstr here! */
5717 o_addstr_with_NUL(output, arg);
5718 debug_print_list("expand_vars_to_list[b]", output, n);
5719 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5720 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5723 /* allow to reuse list[n] later without re-growth */
5724 output->has_empty_slot = 1;
5726 o_addchr(output, '\0');
5732 static char **expand_variables(char **argv, unsigned expflags)
5736 o_string output = NULL_O_STRING;
5738 output.o_expflags = expflags;
5742 n = expand_vars_to_list(&output, n, *argv);
5745 debug_print_list("expand_variables", &output, n);
5747 /* output.data (malloced in one block) gets returned in "list" */
5748 list = o_finalize_list(&output, n);
5749 debug_print_strings("expand_variables[1]", list);
5753 static char **expand_strvec_to_strvec(char **argv)
5755 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5758 #if ENABLE_HUSH_BASH_COMPAT
5759 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5761 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5765 /* Used for expansion of right hand of assignments,
5766 * $((...)), heredocs, variable espansion parts.
5768 * NB: should NOT do globbing!
5769 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5771 static char *expand_string_to_string(const char *str, int do_unbackslash)
5773 #if !ENABLE_HUSH_BASH_COMPAT
5774 const int do_unbackslash = 1;
5776 char *argv[2], **list;
5778 debug_printf_expand("string_to_string<='%s'\n", str);
5779 /* This is generally an optimization, but it also
5780 * handles "", which otherwise trips over !list[0] check below.
5781 * (is this ever happens that we actually get str="" here?)
5783 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5784 //TODO: Can use on strings with \ too, just unbackslash() them?
5785 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5786 return xstrdup(str);
5789 argv[0] = (char*)str;
5791 list = expand_variables(argv, do_unbackslash
5792 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5793 : EXP_FLAG_SINGLEWORD
5796 if (!list[0] || list[1])
5797 bb_error_msg_and_die("BUG in varexp2");
5798 /* actually, just move string 2*sizeof(char*) bytes back */
5799 overlapping_strcpy((char*)list, list[0]);
5801 unbackslash((char*)list);
5802 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5806 /* Used for "eval" builtin */
5807 static char* expand_strvec_to_string(char **argv)
5811 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5812 /* Convert all NULs to spaces */
5817 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5818 bb_error_msg_and_die("BUG in varexp3");
5819 /* bash uses ' ' regardless of $IFS contents */
5824 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5825 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5829 static char **expand_assignments(char **argv, int count)
5834 G.expanded_assignments = p = NULL;
5835 /* Expand assignments into one string each */
5836 for (i = 0; i < count; i++) {
5837 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5839 G.expanded_assignments = NULL;
5844 static void switch_off_special_sigs(unsigned mask)
5847 while ((mask >>= 1) != 0) {
5852 if (G.traps[sig] && !G.traps[sig][0])
5853 /* trap is '', has to remain SIG_IGN */
5856 G.traps[sig] = NULL;
5858 /* We are here only if no trap or trap was not '' */
5859 install_sighandler(sig, SIG_DFL);
5865 void re_execute_shell(char ***to_free, const char *s,
5866 char *g_argv0, char **g_argv,
5867 char **builtin_argv) NORETURN;
5869 static void reset_traps_to_defaults(void)
5871 /* This function is always called in a child shell
5872 * after fork (not vfork, NOMMU doesn't use this function).
5877 /* Child shells are not interactive.
5878 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5879 * Testcase: (while :; do :; done) + ^Z should background.
5880 * Same goes for SIGTERM, SIGHUP, SIGINT.
5882 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5883 if (!G.traps && !mask)
5884 return; /* already no traps and no special sigs */
5886 /* Switch off special sigs */
5887 switch_off_special_sigs(mask);
5889 G_fatal_sig_mask = 0;
5891 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5892 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5893 * remain set in G.special_sig_mask */
5898 /* Reset all sigs to default except ones with empty traps */
5899 for (sig = 0; sig < NSIG; sig++) {
5901 continue; /* no trap: nothing to do */
5902 if (!G.traps[sig][0])
5903 continue; /* empty trap: has to remain SIG_IGN */
5904 /* sig has non-empty trap, reset it: */
5906 G.traps[sig] = NULL;
5907 /* There is no signal for trap 0 (EXIT) */
5910 install_sighandler(sig, pick_sighandler(sig));
5916 static void re_execute_shell(char ***to_free, const char *s,
5917 char *g_argv0, char **g_argv,
5918 char **builtin_argv) NORETURN;
5919 static void re_execute_shell(char ***to_free, const char *s,
5920 char *g_argv0, char **g_argv,
5921 char **builtin_argv)
5923 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5924 /* delims + 2 * (number of bytes in printed hex numbers) */
5925 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5926 char *heredoc_argv[4];
5927 struct variable *cur;
5928 # if ENABLE_HUSH_FUNCTIONS
5929 struct function *funcp;
5933 unsigned long long empty_trap_mask;
5935 if (!g_argv0) { /* heredoc */
5936 argv = heredoc_argv;
5937 argv[0] = (char *) G.argv0_for_re_execing;
5938 argv[1] = (char *) "-<";
5939 argv[2] = (char *) s;
5941 pp = &argv[3]; /* used as pointer to empty environment */
5947 if (pp) while (*pp++)
5950 empty_trap_mask = 0;
5953 for (sig = 1; sig < NSIG; sig++) {
5954 if (G.traps[sig] && !G.traps[sig][0])
5955 empty_trap_mask |= 1LL << sig;
5959 sprintf(param_buf, NOMMU_HACK_FMT
5960 , (unsigned) G.root_pid
5961 , (unsigned) G.root_ppid
5962 , (unsigned) G.last_bg_pid
5963 , (unsigned) G.last_exitcode
5966 IF_HUSH_LOOPS(, G.depth_of_loop)
5968 # undef NOMMU_HACK_FMT
5969 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5970 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5973 for (cur = G.top_var; cur; cur = cur->next) {
5974 if (!cur->flg_export || cur->flg_read_only)
5977 # if ENABLE_HUSH_FUNCTIONS
5978 for (funcp = G.top_func; funcp; funcp = funcp->next)
5984 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5985 *pp++ = (char *) G.argv0_for_re_execing;
5987 for (cur = G.top_var; cur; cur = cur->next) {
5988 if (strcmp(cur->varstr, hush_version_str) == 0)
5990 if (cur->flg_read_only) {
5991 *pp++ = (char *) "-R";
5992 *pp++ = cur->varstr;
5993 } else if (!cur->flg_export) {
5994 *pp++ = (char *) "-V";
5995 *pp++ = cur->varstr;
5998 # if ENABLE_HUSH_FUNCTIONS
5999 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6000 *pp++ = (char *) "-F";
6001 *pp++ = funcp->name;
6002 *pp++ = funcp->body_as_string;
6005 /* We can pass activated traps here. Say, -Tnn:trap_string
6007 * However, POSIX says that subshells reset signals with traps
6009 * I tested bash-3.2 and it not only does that with true subshells
6010 * of the form ( list ), but with any forked children shells.
6011 * I set trap "echo W" WINCH; and then tried:
6013 * { echo 1; sleep 20; echo 2; } &
6014 * while true; do echo 1; sleep 20; echo 2; break; done &
6015 * true | { echo 1; sleep 20; echo 2; } | cat
6017 * In all these cases sending SIGWINCH to the child shell
6018 * did not run the trap. If I add trap "echo V" WINCH;
6019 * _inside_ group (just before echo 1), it works.
6021 * I conclude it means we don't need to pass active traps here.
6023 *pp++ = (char *) "-c";
6026 while (*++builtin_argv)
6027 *pp++ = *builtin_argv;
6028 *pp++ = (char *) "";
6033 /* *pp = NULL; - is already there */
6037 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6038 /* Don't propagate SIG_IGN to the child */
6039 if (SPECIAL_JOBSTOP_SIGS != 0)
6040 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6041 execve(bb_busybox_exec_path, argv, pp);
6042 /* Fallback. Useful for init=/bin/hush usage etc */
6043 if (argv[0][0] == '/')
6044 execve(argv[0], argv, pp);
6045 xfunc_error_retval = 127;
6046 bb_error_msg_and_die("can't re-execute the shell");
6048 #endif /* !BB_MMU */
6051 static int run_and_free_list(struct pipe *pi);
6053 /* Executing from string: eval, sh -c '...'
6054 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6055 * end_trigger controls how often we stop parsing
6056 * NUL: parse all, execute, return
6057 * ';': parse till ';' or newline, execute, repeat till EOF
6059 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6061 /* Why we need empty flag?
6062 * An obscure corner case "false; ``; echo $?":
6063 * empty command in `` should still set $? to 0.
6064 * But we can't just set $? to 0 at the start,
6065 * this breaks "false; echo `echo $?`" case.
6069 struct pipe *pipe_list;
6071 #if ENABLE_HUSH_INTERACTIVE
6072 if (end_trigger == ';')
6073 inp->promptmode = 0; /* PS1 */
6075 pipe_list = parse_stream(NULL, inp, end_trigger);
6076 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6077 /* If we are in "big" script
6078 * (not in `cmd` or something similar)...
6080 if (pipe_list == ERR_PTR && end_trigger == ';') {
6081 /* Discard cached input (rest of line) */
6082 int ch = inp->last_char;
6083 while (ch != EOF && ch != '\n') {
6084 //bb_error_msg("Discarded:'%c'", ch);
6089 /* This stream isn't empty */
6093 if (!pipe_list && empty)
6094 G.last_exitcode = 0;
6097 debug_print_tree(pipe_list, 0);
6098 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6099 run_and_free_list(pipe_list);
6101 if (G_flag_return_in_progress == 1)
6106 static void parse_and_run_string(const char *s)
6108 struct in_str input;
6109 setup_string_in_str(&input, s);
6110 parse_and_run_stream(&input, '\0');
6113 static void parse_and_run_file(FILE *f)
6115 struct in_str input;
6116 setup_file_in_str(&input, f);
6117 parse_and_run_stream(&input, ';');
6120 #if ENABLE_HUSH_TICK
6121 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6126 char **to_free = NULL;
6130 pid = BB_MMU ? xfork() : xvfork();
6131 if (pid == 0) { /* child */
6132 disable_restore_tty_pgrp_on_exit();
6133 /* Process substitution is not considered to be usual
6134 * 'command execution'.
6135 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6142 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6143 close(channel[0]); /* NB: close _first_, then move fd! */
6144 xmove_fd(channel[1], 1);
6145 /* Prevent it from trying to handle ctrl-z etc */
6146 IF_HUSH_JOB(G.run_list_level = 1;)
6147 /* Awful hack for `trap` or $(trap).
6149 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6150 * contains an example where "trap" is executed in a subshell:
6152 * save_traps=$(trap)
6154 * eval "$save_traps"
6156 * Standard does not say that "trap" in subshell shall print
6157 * parent shell's traps. It only says that its output
6158 * must have suitable form, but then, in the above example
6159 * (which is not supposed to be normative), it implies that.
6161 * bash (and probably other shell) does implement it
6162 * (traps are reset to defaults, but "trap" still shows them),
6163 * but as a result, "trap" logic is hopelessly messed up:
6166 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6167 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6168 * # true | trap <--- trap is in subshell - no output (ditto)
6169 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6170 * trap -- 'echo Ho' SIGWINCH
6171 * # echo `(trap)` <--- in subshell in subshell - output
6172 * trap -- 'echo Ho' SIGWINCH
6173 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6174 * trap -- 'echo Ho' SIGWINCH
6176 * The rules when to forget and when to not forget traps
6177 * get really complex and nonsensical.
6179 * Our solution: ONLY bare $(trap) or `trap` is special.
6181 s = skip_whitespace(s);
6182 if (is_prefixed_with(s, "trap")
6183 && skip_whitespace(s + 4)[0] == '\0'
6185 static const char *const argv[] = { NULL, NULL };
6186 builtin_trap((char**)argv);
6187 fflush_all(); /* important */
6191 reset_traps_to_defaults();
6192 parse_and_run_string(s);
6193 _exit(G.last_exitcode);
6195 /* We re-execute after vfork on NOMMU. This makes this script safe:
6196 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6197 * huge=`cat BIG` # was blocking here forever
6200 re_execute_shell(&to_free,
6210 # if ENABLE_HUSH_FAST
6212 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6213 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6214 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6216 enable_restore_tty_pgrp_on_exit();
6221 return remember_FILE(xfdopen_for_read(channel[0]));
6224 /* Return code is exit status of the process that is run. */
6225 static int process_command_subs(o_string *dest, const char *s)
6228 struct in_str pipe_str;
6230 int status, ch, eol_cnt;
6232 fp = generate_stream_from_string(s, &pid);
6234 /* Now send results of command back into original context */
6235 setup_file_in_str(&pipe_str, fp);
6237 while ((ch = i_getch(&pipe_str)) != EOF) {
6243 o_addchr(dest, '\n');
6246 o_addQchr(dest, ch);
6249 debug_printf("done reading from `cmd` pipe, closing it\n");
6250 fclose_and_forget(fp);
6251 /* We need to extract exitcode. Test case
6252 * "true; echo `sleep 1; false` $?"
6254 safe_waitpid(pid, &status, 0);
6255 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6256 return WEXITSTATUS(status);
6258 #endif /* ENABLE_HUSH_TICK */
6261 static void setup_heredoc(struct redir_struct *redir)
6263 struct fd_pair pair;
6266 /* the _body_ of heredoc (misleading field name) */
6267 const char *heredoc = redir->rd_filename;
6274 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6275 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6279 len = strlen(heredoc);
6281 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6283 xmove_fd(pair.rd, redir->rd_fd);
6285 /* Try writing without forking. Newer kernels have
6286 * dynamically growing pipes. Must use non-blocking write! */
6289 written = write(pair.wr, heredoc, len);
6300 ndelay_off(pair.wr);
6302 /* Okay, pipe buffer was not big enough */
6303 /* Note: we must not create a stray child (bastard? :)
6304 * for the unsuspecting parent process. Child creates a grandchild
6305 * and exits before parent execs the process which consumes heredoc
6306 * (that exec happens after we return from this function) */
6313 disable_restore_tty_pgrp_on_exit();
6314 pid = BB_MMU ? xfork() : xvfork();
6318 close(redir->rd_fd); /* read side of the pipe */
6320 full_write(pair.wr, heredoc, len); /* may loop or block */
6323 /* Delegate blocking writes to another process */
6324 xmove_fd(pair.wr, STDOUT_FILENO);
6325 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6329 #if ENABLE_HUSH_FAST
6331 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6333 enable_restore_tty_pgrp_on_exit();
6339 wait(NULL); /* wait till child has died */
6342 /* fd: redirect wants this fd to be used (e.g. 3>file).
6343 * Move all conflicting internally used fds,
6344 * and remember them so that we can restore them later.
6346 static int save_fds_on_redirect(int fd, int squirrel[3])
6349 /* Handle redirects of fds 0,1,2 */
6351 /* If we collide with an already moved stdio fd... */
6352 if (fd == squirrel[0]) {
6353 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6356 if (fd == squirrel[1]) {
6357 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6360 if (fd == squirrel[2]) {
6361 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6364 /* If we are about to redirect stdio fd, and did not yet move it... */
6365 if (fd <= 2 && squirrel[fd] < 0) {
6366 /* We avoid taking stdio fds */
6367 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6368 if (squirrel[fd] < 0 && errno != EBADF)
6370 return 0; /* "we did not close fd" */
6374 #if ENABLE_HUSH_INTERACTIVE
6375 if (fd != 0 && fd == G.interactive_fd) {
6376 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6381 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6382 * (1) Redirect in a forked child. No need to save FILEs' fds,
6383 * we aren't going to use them anymore, ok to trash.
6384 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6385 * but how are we doing to use them?
6386 * "fileno(fd) = new_fd" can't be done.
6391 return save_FILEs_on_redirect(fd);
6394 static void restore_redirects(int squirrel[3])
6397 for (i = 0; i <= 2; i++) {
6400 /* We simply die on error */
6405 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6407 restore_redirected_FILEs();
6410 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6411 * and stderr if they are redirected. */
6412 static int setup_redirects(struct command *prog, int squirrel[])
6415 struct redir_struct *redir;
6417 for (redir = prog->redirects; redir; redir = redir->next) {
6418 if (redir->rd_type == REDIRECT_HEREDOC2) {
6419 /* "rd_fd<<HERE" case */
6420 save_fds_on_redirect(redir->rd_fd, squirrel);
6421 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6423 debug_printf_parse("set heredoc '%s'\n",
6424 redir->rd_filename);
6425 setup_heredoc(redir);
6429 if (redir->rd_dup == REDIRFD_TO_FILE) {
6430 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6432 if (redir->rd_filename == NULL) {
6435 * "cmd >" (no filename)
6436 * "cmd > <file" (2nd redirect starts too early)
6438 die_if_script("syntax error: %s", "invalid redirect");
6441 mode = redir_table[redir->rd_type].mode;
6442 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6443 openfd = open_or_warn(p, mode);
6446 /* Error message from open_or_warn can be lost
6447 * if stderr has been redirected, but bash
6448 * and ash both lose it as well
6449 * (though zsh doesn't!)
6454 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6455 openfd = redir->rd_dup;
6458 if (openfd != redir->rd_fd) {
6459 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6460 if (openfd == REDIRFD_CLOSE) {
6461 /* "rd_fd >&-" means "close me" */
6463 /* ^^^ optimization: saving may already
6464 * have closed it. If not... */
6465 close(redir->rd_fd);
6468 xdup2(openfd, redir->rd_fd);
6469 if (redir->rd_dup == REDIRFD_TO_FILE)
6470 /* "rd_fd > FILE" */
6472 /* else: "rd_fd > rd_dup" */
6479 static char *find_in_path(const char *arg)
6482 const char *PATH = get_local_var_value("PATH");
6488 const char *end = strchrnul(PATH, ':');
6489 int sz = end - PATH; /* must be int! */
6493 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6495 /* We have xxx::yyyy in $PATH,
6496 * it means "use current dir" */
6499 if (access(ret, F_OK) == 0)
6512 static const struct built_in_command *find_builtin_helper(const char *name,
6513 const struct built_in_command *x,
6514 const struct built_in_command *end)
6517 if (strcmp(name, x->b_cmd) != 0) {
6521 debug_printf_exec("found builtin '%s'\n", name);
6526 static const struct built_in_command *find_builtin1(const char *name)
6528 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6530 static const struct built_in_command *find_builtin(const char *name)
6532 const struct built_in_command *x = find_builtin1(name);
6535 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6538 #if ENABLE_HUSH_FUNCTIONS
6539 static struct function **find_function_slot(const char *name)
6541 struct function **funcpp = &G.top_func;
6543 if (strcmp(name, (*funcpp)->name) == 0) {
6546 funcpp = &(*funcpp)->next;
6551 static const struct function *find_function(const char *name)
6553 const struct function *funcp = *find_function_slot(name);
6555 debug_printf_exec("found function '%s'\n", name);
6559 /* Note: takes ownership on name ptr */
6560 static struct function *new_function(char *name)
6562 struct function **funcpp = find_function_slot(name);
6563 struct function *funcp = *funcpp;
6565 if (funcp != NULL) {
6566 struct command *cmd = funcp->parent_cmd;
6567 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6569 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6571 /* Note: if !funcp->body, do not free body_as_string!
6572 * This is a special case of "-F name body" function:
6573 * body_as_string was not malloced! */
6575 free_pipe_list(funcp->body);
6577 free(funcp->body_as_string);
6581 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6582 cmd->argv[0] = funcp->name;
6583 cmd->group = funcp->body;
6585 cmd->group_as_string = funcp->body_as_string;
6589 debug_printf_exec("remembering new function '%s'\n", name);
6590 funcp = *funcpp = xzalloc(sizeof(*funcp));
6591 /*funcp->next = NULL;*/
6598 static void unset_func(const char *name)
6600 struct function **funcpp = find_function_slot(name);
6601 struct function *funcp = *funcpp;
6603 if (funcp != NULL) {
6604 debug_printf_exec("freeing function '%s'\n", funcp->name);
6605 *funcpp = funcp->next;
6606 /* funcp is unlinked now, deleting it.
6607 * Note: if !funcp->body, the function was created by
6608 * "-F name body", do not free ->body_as_string
6609 * and ->name as they were not malloced. */
6611 free_pipe_list(funcp->body);
6614 free(funcp->body_as_string);
6622 #define exec_function(to_free, funcp, argv) \
6623 exec_function(funcp, argv)
6625 static void exec_function(char ***to_free,
6626 const struct function *funcp,
6627 char **argv) NORETURN;
6628 static void exec_function(char ***to_free,
6629 const struct function *funcp,
6635 argv[0] = G.global_argv[0];
6636 G.global_argv = argv;
6640 /* On MMU, funcp->body is always non-NULL */
6641 n = run_list(funcp->body);
6645 re_execute_shell(to_free,
6646 funcp->body_as_string,
6653 static int run_function(const struct function *funcp, char **argv)
6659 save_and_replace_G_args(&sv, argv);
6661 /* "we are in function, ok to use return" */
6662 sv_flg = G_flag_return_in_progress;
6663 G_flag_return_in_progress = -1;
6664 # if ENABLE_HUSH_LOCAL
6665 G.func_nest_level++;
6668 /* On MMU, funcp->body is always non-NULL */
6671 /* Function defined by -F */
6672 parse_and_run_string(funcp->body_as_string);
6673 rc = G.last_exitcode;
6677 rc = run_list(funcp->body);
6680 # if ENABLE_HUSH_LOCAL
6682 struct variable *var;
6683 struct variable **var_pp;
6685 var_pp = &G.top_var;
6686 while ((var = *var_pp) != NULL) {
6687 if (var->func_nest_level < G.func_nest_level) {
6688 var_pp = &var->next;
6692 if (var->flg_export)
6693 bb_unsetenv(var->varstr);
6694 /* Remove from global list */
6695 *var_pp = var->next;
6701 G.func_nest_level--;
6704 G_flag_return_in_progress = sv_flg;
6706 restore_G_args(&sv, argv);
6710 #endif /* ENABLE_HUSH_FUNCTIONS */
6714 #define exec_builtin(to_free, x, argv) \
6715 exec_builtin(x, argv)
6717 #define exec_builtin(to_free, x, argv) \
6718 exec_builtin(to_free, argv)
6720 static void exec_builtin(char ***to_free,
6721 const struct built_in_command *x,
6722 char **argv) NORETURN;
6723 static void exec_builtin(char ***to_free,
6724 const struct built_in_command *x,
6730 rcode = x->b_function(argv);
6735 /* On NOMMU, we must never block!
6736 * Example: { sleep 99 | read line; } & echo Ok
6738 re_execute_shell(to_free,
6747 static void execvp_or_die(char **argv) NORETURN;
6748 static void execvp_or_die(char **argv)
6751 debug_printf_exec("execing '%s'\n", argv[0]);
6752 /* Don't propagate SIG_IGN to the child */
6753 if (SPECIAL_JOBSTOP_SIGS != 0)
6754 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6755 execvp(argv[0], argv);
6757 if (errno == EACCES) e = 126;
6758 if (errno == ENOENT) e = 127;
6759 bb_perror_msg("can't execute '%s'", argv[0]);
6763 #if ENABLE_HUSH_MODE_X
6764 static void dump_cmd_in_x_mode(char **argv)
6766 if (G_x_mode && argv) {
6767 /* We want to output the line in one write op */
6775 len += strlen(argv[n++]) + 1;
6781 p += sprintf(p, " %s", argv[n++]);
6789 # define dump_cmd_in_x_mode(argv) ((void)0)
6793 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6794 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6795 #define pseudo_exec(nommu_save, command, argv_expanded) \
6796 pseudo_exec(command, argv_expanded)
6799 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6801 * Don't exit() here. If you don't exec, use _exit instead.
6802 * The at_exit handlers apparently confuse the calling process,
6803 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6805 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6806 char **argv, int assignment_cnt,
6807 char **argv_expanded) NORETURN;
6808 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6809 char **argv, int assignment_cnt,
6810 char **argv_expanded)
6814 new_env = expand_assignments(argv, assignment_cnt);
6815 dump_cmd_in_x_mode(new_env);
6817 if (!argv[assignment_cnt]) {
6818 /* Case when we are here: ... | var=val | ...
6819 * (note that we do not exit early, i.e., do not optimize out
6820 * expand_assignments(): think about ... | var=`sleep 1` | ...
6822 free_strings(new_env);
6823 _exit(EXIT_SUCCESS);
6827 set_vars_and_save_old(new_env);
6828 free(new_env); /* optional */
6829 /* we can also destroy set_vars_and_save_old's return value,
6832 nommu_save->new_env = new_env;
6833 nommu_save->old_vars = set_vars_and_save_old(new_env);
6836 if (argv_expanded) {
6837 argv = argv_expanded;
6839 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6841 nommu_save->argv = argv;
6844 dump_cmd_in_x_mode(argv);
6846 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6847 if (strchr(argv[0], '/') != NULL)
6851 /* Check if the command matches any of the builtins.
6852 * Depending on context, this might be redundant. But it's
6853 * easier to waste a few CPU cycles than it is to figure out
6854 * if this is one of those cases.
6857 /* On NOMMU, it is more expensive to re-execute shell
6858 * just in order to run echo or test builtin.
6859 * It's better to skip it here and run corresponding
6860 * non-builtin later. */
6861 const struct built_in_command *x;
6862 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6864 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6867 #if ENABLE_HUSH_FUNCTIONS
6868 /* Check if the command matches any functions */
6870 const struct function *funcp = find_function(argv[0]);
6872 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6877 #if ENABLE_FEATURE_SH_STANDALONE
6878 /* Check if the command matches any busybox applets */
6880 int a = find_applet_by_name(argv[0]);
6882 # if BB_MMU /* see above why on NOMMU it is not allowed */
6883 if (APPLET_IS_NOEXEC(a)) {
6884 /* Do not leak open fds from opened script files etc */
6885 close_all_FILE_list();
6886 debug_printf_exec("running applet '%s'\n", argv[0]);
6887 run_applet_no_and_exit(a, argv);
6890 /* Re-exec ourselves */
6891 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6892 /* Don't propagate SIG_IGN to the child */
6893 if (SPECIAL_JOBSTOP_SIGS != 0)
6894 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6895 execv(bb_busybox_exec_path, argv);
6896 /* If they called chroot or otherwise made the binary no longer
6897 * executable, fall through */
6902 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6905 execvp_or_die(argv);
6908 /* Called after [v]fork() in run_pipe
6910 static void pseudo_exec(nommu_save_t *nommu_save,
6911 struct command *command,
6912 char **argv_expanded) NORETURN;
6913 static void pseudo_exec(nommu_save_t *nommu_save,
6914 struct command *command,
6915 char **argv_expanded)
6917 if (command->argv) {
6918 pseudo_exec_argv(nommu_save, command->argv,
6919 command->assignment_cnt, argv_expanded);
6922 if (command->group) {
6923 /* Cases when we are here:
6926 * ... | ( list ) | ...
6927 * ... | { list } | ...
6931 debug_printf_exec("pseudo_exec: run_list\n");
6932 reset_traps_to_defaults();
6933 rcode = run_list(command->group);
6934 /* OK to leak memory by not calling free_pipe_list,
6935 * since this process is about to exit */
6938 re_execute_shell(&nommu_save->argv_from_re_execing,
6939 command->group_as_string,
6946 /* Case when we are here: ... | >file */
6947 debug_printf_exec("pseudo_exec'ed null command\n");
6948 _exit(EXIT_SUCCESS);
6952 static const char *get_cmdtext(struct pipe *pi)
6958 /* This is subtle. ->cmdtext is created only on first backgrounding.
6959 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6960 * On subsequent bg argv is trashed, but we won't use it */
6963 argv = pi->cmds[0].argv;
6964 if (!argv || !argv[0]) {
6965 pi->cmdtext = xzalloc(1);
6971 len += strlen(*argv) + 1;
6975 argv = pi->cmds[0].argv;
6977 len = strlen(*argv);
6978 memcpy(p, *argv, len);
6986 static void insert_bg_job(struct pipe *pi)
6988 struct pipe *job, **jobp;
6991 /* Linear search for the ID of the job to use */
6993 for (job = G.job_list; job; job = job->next)
6994 if (job->jobid >= pi->jobid)
6995 pi->jobid = job->jobid + 1;
6997 /* Add job to the list of running jobs */
6999 while ((job = *jobp) != NULL)
7001 job = *jobp = xmalloc(sizeof(*job));
7003 *job = *pi; /* physical copy */
7005 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7006 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7007 for (i = 0; i < pi->num_cmds; i++) {
7008 job->cmds[i].pid = pi->cmds[i].pid;
7009 /* all other fields are not used and stay zero */
7011 job->cmdtext = xstrdup(get_cmdtext(pi));
7013 if (G_interactive_fd)
7014 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
7015 G.last_jobid = job->jobid;
7018 static void remove_bg_job(struct pipe *pi)
7020 struct pipe *prev_pipe;
7022 if (pi == G.job_list) {
7023 G.job_list = pi->next;
7025 prev_pipe = G.job_list;
7026 while (prev_pipe->next != pi)
7027 prev_pipe = prev_pipe->next;
7028 prev_pipe->next = pi->next;
7031 G.last_jobid = G.job_list->jobid;
7036 /* Remove a backgrounded job */
7037 static void delete_finished_bg_job(struct pipe *pi)
7044 /* Check to see if any processes have exited -- if they
7045 * have, figure out why and see if a job has completed */
7046 static int checkjobs(struct pipe *fg_pipe)
7056 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7058 attributes = WUNTRACED;
7059 if (fg_pipe == NULL)
7060 attributes |= WNOHANG;
7063 #if ENABLE_HUSH_FAST
7064 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7065 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7066 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7067 /* There was neither fork nor SIGCHLD since last waitpid */
7068 /* Avoid doing waitpid syscall if possible */
7069 if (!G.we_have_children) {
7073 if (fg_pipe == NULL) { /* is WNOHANG set? */
7074 /* We have children, but they did not exit
7075 * or stop yet (we saw no SIGCHLD) */
7078 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7082 /* Do we do this right?
7083 * bash-3.00# sleep 20 | false
7085 * [3]+ Stopped sleep 20 | false
7086 * bash-3.00# echo $?
7087 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7088 * [hush 1.14.0: yes we do it right]
7095 #if ENABLE_HUSH_FAST
7096 i = G.count_SIGCHLD;
7098 childpid = waitpid(-1, &status, attributes);
7099 if (childpid <= 0) {
7100 if (childpid && errno != ECHILD)
7101 bb_perror_msg("waitpid");
7102 #if ENABLE_HUSH_FAST
7103 else { /* Until next SIGCHLD, waitpid's are useless */
7104 G.we_have_children = (childpid == 0);
7105 G.handled_SIGCHLD = i;
7106 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7111 dead = WIFEXITED(status) || WIFSIGNALED(status);
7114 if (WIFSTOPPED(status))
7115 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7116 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7117 if (WIFSIGNALED(status))
7118 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7119 childpid, WTERMSIG(status), WEXITSTATUS(status));
7120 if (WIFEXITED(status))
7121 debug_printf_jobs("pid %d exited, exitcode %d\n",
7122 childpid, WEXITSTATUS(status));
7124 /* Were we asked to wait for fg pipe? */
7126 i = fg_pipe->num_cmds;
7128 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7129 if (fg_pipe->cmds[i].pid != childpid)
7133 fg_pipe->cmds[i].pid = 0;
7134 fg_pipe->alive_cmds--;
7135 ex = WEXITSTATUS(status);
7136 /* bash prints killer signal's name for *last*
7137 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7138 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7140 if (WIFSIGNALED(status)) {
7141 int sig = WTERMSIG(status);
7142 if (i == fg_pipe->num_cmds-1)
7143 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7144 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7145 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7146 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7147 * Maybe we need to use sig | 128? */
7150 fg_pipe->cmds[i].cmd_exitcode = ex;
7152 fg_pipe->stopped_cmds++;
7154 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7155 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7156 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
7157 /* All processes in fg pipe have exited or stopped */
7158 i = fg_pipe->num_cmds;
7160 rcode = fg_pipe->cmds[i].cmd_exitcode;
7161 /* usually last process gives overall exitstatus,
7162 * but with "set -o pipefail", last *failed* process does */
7163 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7166 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
7167 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7168 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7169 * and "killall -STOP cat" */
7170 if (G_interactive_fd) {
7172 if (fg_pipe->alive_cmds != 0)
7173 insert_bg_job(fg_pipe);
7177 if (fg_pipe->alive_cmds == 0)
7180 /* There are still running processes in the fg pipe */
7181 goto wait_more; /* do waitpid again */
7183 /* it wasnt fg_pipe, look for process in bg pipes */
7187 /* We asked to wait for bg or orphaned children */
7188 /* No need to remember exitcode in this case */
7189 for (pi = G.job_list; pi; pi = pi->next) {
7190 for (i = 0; i < pi->num_cmds; i++) {
7191 if (pi->cmds[i].pid == childpid)
7192 goto found_pi_and_prognum;
7195 /* Happens when shell is used as init process (init=/bin/sh) */
7196 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7197 continue; /* do waitpid again */
7199 found_pi_and_prognum:
7202 pi->cmds[i].pid = 0;
7204 if (!pi->alive_cmds) {
7205 if (G_interactive_fd)
7206 printf(JOB_STATUS_FORMAT, pi->jobid,
7207 "Done", pi->cmdtext);
7208 delete_finished_bg_job(pi);
7215 } /* while (waitpid succeeds)... */
7221 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7224 int rcode = checkjobs(fg_pipe);
7225 if (G_saved_tty_pgrp) {
7226 /* Job finished, move the shell to the foreground */
7227 p = getpgrp(); /* our process group id */
7228 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7229 tcsetpgrp(G_interactive_fd, p);
7235 /* Start all the jobs, but don't wait for anything to finish.
7238 * Return code is normally -1, when the caller has to wait for children
7239 * to finish to determine the exit status of the pipe. If the pipe
7240 * is a simple builtin command, however, the action is done by the
7241 * time run_pipe returns, and the exit code is provided as the
7244 * Returns -1 only if started some children. IOW: we have to
7245 * mask out retvals of builtins etc with 0xff!
7247 * The only case when we do not need to [v]fork is when the pipe
7248 * is single, non-backgrounded, non-subshell command. Examples:
7249 * cmd ; ... { list } ; ...
7250 * cmd && ... { list } && ...
7251 * cmd || ... { list } || ...
7252 * If it is, then we can run cmd as a builtin, NOFORK,
7253 * or (if SH_STANDALONE) an applet, and we can run the { list }
7254 * with run_list. If it isn't one of these, we fork and exec cmd.
7256 * Cases when we must fork:
7257 * non-single: cmd | cmd
7258 * backgrounded: cmd & { list } &
7259 * subshell: ( list ) [&]
7261 #if !ENABLE_HUSH_MODE_X
7262 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7263 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7265 static int redirect_and_varexp_helper(char ***new_env_p,
7266 struct variable **old_vars_p,
7267 struct command *command,
7269 char **argv_expanded)
7271 /* setup_redirects acts on file descriptors, not FILEs.
7272 * This is perfect for work that comes after exec().
7273 * Is it really safe for inline use? Experimentally,
7274 * things seem to work. */
7275 int rcode = setup_redirects(command, squirrel);
7277 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7278 *new_env_p = new_env;
7279 dump_cmd_in_x_mode(new_env);
7280 dump_cmd_in_x_mode(argv_expanded);
7282 *old_vars_p = set_vars_and_save_old(new_env);
7286 static NOINLINE int run_pipe(struct pipe *pi)
7288 static const char *const null_ptr = NULL;
7292 struct command *command;
7293 char **argv_expanded;
7295 /* it is not always needed, but we aim to smaller code */
7296 int squirrel[] = { -1, -1, -1 };
7299 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7302 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7303 * Result should be 3 lines: q w e, qwe, q w e
7305 G.ifs = get_local_var_value("IFS");
7309 IF_HUSH_JOB(pi->pgrp = -1;)
7310 pi->stopped_cmds = 0;
7311 command = &pi->cmds[0];
7312 argv_expanded = NULL;
7314 if (pi->num_cmds != 1
7315 || pi->followup == PIPE_BG
7316 || command->cmd_type == CMD_SUBSHELL
7323 debug_printf_exec(": group:%p argv:'%s'\n",
7324 command->group, command->argv ? command->argv[0] : "NONE");
7326 if (command->group) {
7327 #if ENABLE_HUSH_FUNCTIONS
7328 if (command->cmd_type == CMD_FUNCDEF) {
7329 /* "executing" func () { list } */
7330 struct function *funcp;
7332 funcp = new_function(command->argv[0]);
7333 /* funcp->name is already set to argv[0] */
7334 funcp->body = command->group;
7336 funcp->body_as_string = command->group_as_string;
7337 command->group_as_string = NULL;
7339 command->group = NULL;
7340 command->argv[0] = NULL;
7341 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7342 funcp->parent_cmd = command;
7343 command->child_func = funcp;
7345 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7347 return EXIT_SUCCESS;
7351 debug_printf("non-subshell group\n");
7352 rcode = 1; /* exitcode if redir failed */
7353 if (setup_redirects(command, squirrel) == 0) {
7354 debug_printf_exec(": run_list\n");
7355 rcode = run_list(command->group) & 0xff;
7357 restore_redirects(squirrel);
7358 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7360 debug_printf_exec("run_pipe: return %d\n", rcode);
7364 argv = command->argv ? command->argv : (char **) &null_ptr;
7366 const struct built_in_command *x;
7367 #if ENABLE_HUSH_FUNCTIONS
7368 const struct function *funcp;
7372 char **new_env = NULL;
7373 struct variable *old_vars = NULL;
7375 if (argv[command->assignment_cnt] == NULL) {
7376 /* Assignments, but no command */
7377 /* Ensure redirects take effect (that is, create files).
7378 * Try "a=t >file" */
7379 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7380 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7381 /* Set shell variables */
7385 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7386 /* Do we need to flag set_local_var() errors?
7387 * "assignment to readonly var" and "putenv error"
7392 /* Redirect error sets $? to 1. Otherwise,
7393 * if evaluating assignment value set $?, retain it.
7394 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7396 rcode = G.last_exitcode;
7397 /* Exit, _skipping_ variable restoring code: */
7398 goto clean_up_and_ret0;
7400 #else /* Older, bigger, but more correct code */
7402 rcode = setup_redirects(command, squirrel);
7403 restore_redirects(squirrel);
7404 /* Set shell variables */
7406 bb_putchar_stderr('+');
7408 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7410 fprintf(stderr, " %s", p);
7411 debug_printf_exec("set shell var:'%s'->'%s'\n",
7413 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7414 /* Do we need to flag set_local_var() errors?
7415 * "assignment to readonly var" and "putenv error"
7420 bb_putchar_stderr('\n');
7421 /* Redirect error sets $? to 1. Otherwise,
7422 * if evaluating assignment value set $?, retain it.
7423 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7425 rcode = G.last_exitcode;
7426 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7428 debug_printf_exec("run_pipe: return %d\n", rcode);
7433 /* Expand the rest into (possibly) many strings each */
7434 #if ENABLE_HUSH_BASH_COMPAT
7435 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7436 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7440 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7443 /* if someone gives us an empty string: `cmd with empty output` */
7444 if (!argv_expanded[0]) {
7445 free(argv_expanded);
7447 return G.last_exitcode;
7450 x = find_builtin(argv_expanded[0]);
7451 #if ENABLE_HUSH_FUNCTIONS
7454 funcp = find_function(argv_expanded[0]);
7458 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7459 debug_printf("exec with redirects only\n");
7460 rcode = setup_redirects(command, NULL);
7461 /* rcode=1 can be if redir file can't be opened */
7462 goto clean_up_and_ret1;
7465 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7468 debug_printf_exec(": builtin '%s' '%s'...\n",
7469 x->b_cmd, argv_expanded[1]);
7471 rcode = x->b_function(argv_expanded) & 0xff;
7474 #if ENABLE_HUSH_FUNCTIONS
7476 # if ENABLE_HUSH_LOCAL
7477 struct variable **sv;
7478 sv = G.shadowed_vars_pp;
7479 G.shadowed_vars_pp = &old_vars;
7481 debug_printf_exec(": function '%s' '%s'...\n",
7482 funcp->name, argv_expanded[1]);
7483 rcode = run_function(funcp, argv_expanded) & 0xff;
7484 # if ENABLE_HUSH_LOCAL
7485 G.shadowed_vars_pp = sv;
7491 unset_vars(new_env);
7493 /* clean_up_and_ret0: */
7494 restore_redirects(squirrel);
7496 free(argv_expanded);
7497 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7499 debug_printf_exec("run_pipe return %d\n", rcode);
7503 if (ENABLE_FEATURE_SH_NOFORK) {
7504 int n = find_applet_by_name(argv_expanded[0]);
7505 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7506 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7508 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7509 argv_expanded[0], argv_expanded[1]);
7510 rcode = run_nofork_applet(n, argv_expanded);
7512 goto clean_up_and_ret;
7515 /* It is neither builtin nor applet. We must fork. */
7519 /* NB: argv_expanded may already be created, and that
7520 * might include `cmd` runs! Do not rerun it! We *must*
7521 * use argv_expanded if it's non-NULL */
7523 /* Going to fork a child per each pipe member */
7528 while (cmd_no < pi->num_cmds) {
7529 struct fd_pair pipefds;
7531 volatile nommu_save_t nommu_save;
7532 nommu_save.new_env = NULL;
7533 nommu_save.old_vars = NULL;
7534 nommu_save.argv = NULL;
7535 nommu_save.argv_from_re_execing = NULL;
7537 command = &pi->cmds[cmd_no];
7539 if (command->argv) {
7540 debug_printf_exec(": pipe member '%s' '%s'...\n",
7541 command->argv[0], command->argv[1]);
7543 debug_printf_exec(": pipe member with no argv\n");
7546 /* pipes are inserted between pairs of commands */
7549 if (cmd_no < pi->num_cmds)
7550 xpiped_pair(pipefds);
7552 command->pid = BB_MMU ? fork() : vfork();
7553 if (!command->pid) { /* child */
7555 disable_restore_tty_pgrp_on_exit();
7556 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7558 /* Every child adds itself to new process group
7559 * with pgid == pid_of_first_child_in_pipe */
7560 if (G.run_list_level == 1 && G_interactive_fd) {
7563 if (pgrp < 0) /* true for 1st process only */
7565 if (setpgid(0, pgrp) == 0
7566 && pi->followup != PIPE_BG
7567 && G_saved_tty_pgrp /* we have ctty */
7569 /* We do it in *every* child, not just first,
7571 tcsetpgrp(G_interactive_fd, pgrp);
7575 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7576 /* 1st cmd in backgrounded pipe
7577 * should have its stdin /dev/null'ed */
7579 if (open(bb_dev_null, O_RDONLY))
7580 xopen("/", O_RDONLY);
7582 xmove_fd(next_infd, 0);
7584 xmove_fd(pipefds.wr, 1);
7587 /* Like bash, explicit redirects override pipes,
7588 * and the pipe fd (fd#1) is available for dup'ing:
7589 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7590 * of cmd1 goes into pipe.
7592 if (setup_redirects(command, NULL)) {
7593 /* Happens when redir file can't be opened:
7594 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7596 * hush: can't open '/qwe/rty': No such file or directory
7598 * (echo BAR is not executed, it hits _exit(1) below)
7603 /* Stores to nommu_save list of env vars putenv'ed
7604 * (NOMMU, on MMU we don't need that) */
7605 /* cast away volatility... */
7606 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7607 /* pseudo_exec() does not return */
7610 /* parent or error */
7611 #if ENABLE_HUSH_FAST
7613 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7615 enable_restore_tty_pgrp_on_exit();
7617 /* Clean up after vforked child */
7618 free(nommu_save.argv);
7619 free(nommu_save.argv_from_re_execing);
7620 unset_vars(nommu_save.new_env);
7621 add_vars(nommu_save.old_vars);
7623 free(argv_expanded);
7624 argv_expanded = NULL;
7625 if (command->pid < 0) { /* [v]fork failed */
7626 /* Clearly indicate, was it fork or vfork */
7627 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7631 /* Second and next children need to know pid of first one */
7633 pi->pgrp = command->pid;
7639 if (cmd_no < pi->num_cmds)
7641 /* Pass read (output) pipe end to next iteration */
7642 next_infd = pipefds.rd;
7645 if (!pi->alive_cmds) {
7647 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7652 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7656 /* NB: called by pseudo_exec, and therefore must not modify any
7657 * global data until exec/_exit (we can be a child after vfork!) */
7658 static int run_list(struct pipe *pi)
7660 #if ENABLE_HUSH_CASE
7661 char *case_word = NULL;
7663 #if ENABLE_HUSH_LOOPS
7664 struct pipe *loop_top = NULL;
7665 char **for_lcur = NULL;
7666 char **for_list = NULL;
7668 smallint last_followup;
7670 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7671 smalluint cond_code = 0;
7673 enum { cond_code = 0 };
7676 smallint rword; /* RES_foo */
7677 smallint last_rword; /* ditto */
7680 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7683 #if ENABLE_HUSH_LOOPS
7684 /* Check syntax for "for" */
7687 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7688 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7690 /* current word is FOR or IN (BOLD in comments below) */
7691 if (cpipe->next == NULL) {
7692 syntax_error("malformed for");
7694 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7697 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7698 if (cpipe->next->res_word == RES_DO)
7700 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7701 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7702 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7704 syntax_error("malformed for");
7706 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7713 /* Past this point, all code paths should jump to ret: label
7714 * in order to return, no direct "return" statements please.
7715 * This helps to ensure that no memory is leaked. */
7723 last_rword = RES_XXXX;
7725 last_followup = PIPE_SEQ;
7726 rcode = G.last_exitcode;
7728 /* Go through list of pipes, (maybe) executing them. */
7729 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7732 if (G_flag_return_in_progress == 1)
7735 IF_HAS_KEYWORDS(rword = pi->res_word;)
7736 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7737 rword, cond_code, last_rword);
7738 #if ENABLE_HUSH_LOOPS
7739 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7740 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7742 /* start of a loop: remember where loop starts */
7747 /* Still in the same "if...", "then..." or "do..." branch? */
7748 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7749 if ((rcode == 0 && last_followup == PIPE_OR)
7750 || (rcode != 0 && last_followup == PIPE_AND)
7752 /* It is "<true> || CMD" or "<false> && CMD"
7753 * and we should not execute CMD */
7754 debug_printf_exec("skipped cmd because of || or &&\n");
7755 last_followup = pi->followup;
7756 goto dont_check_jobs_but_continue;
7759 last_followup = pi->followup;
7760 IF_HAS_KEYWORDS(last_rword = rword;)
7763 if (rword == RES_THEN) {
7764 /* if false; then ... fi has exitcode 0! */
7765 G.last_exitcode = rcode = EXIT_SUCCESS;
7766 /* "if <false> THEN cmd": skip cmd */
7770 if (rword == RES_ELSE || rword == RES_ELIF) {
7771 /* "if <true> then ... ELSE/ELIF cmd":
7772 * skip cmd and all following ones */
7777 #if ENABLE_HUSH_LOOPS
7778 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7780 /* first loop through for */
7782 static const char encoded_dollar_at[] ALIGN1 = {
7783 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7784 }; /* encoded representation of "$@" */
7785 static const char *const encoded_dollar_at_argv[] = {
7786 encoded_dollar_at, NULL
7787 }; /* argv list with one element: "$@" */
7790 vals = (char**)encoded_dollar_at_argv;
7791 if (pi->next->res_word == RES_IN) {
7792 /* if no variable values after "in" we skip "for" */
7793 if (!pi->next->cmds[0].argv) {
7794 G.last_exitcode = rcode = EXIT_SUCCESS;
7795 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7798 vals = pi->next->cmds[0].argv;
7799 } /* else: "for var; do..." -> assume "$@" list */
7800 /* create list of variable values */
7801 debug_print_strings("for_list made from", vals);
7802 for_list = expand_strvec_to_strvec(vals);
7803 for_lcur = for_list;
7804 debug_print_strings("for_list", for_list);
7807 /* "for" loop is over, clean up */
7813 /* Insert next value from for_lcur */
7814 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7815 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7818 if (rword == RES_IN) {
7819 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7821 if (rword == RES_DONE) {
7822 continue; /* "done" has no cmds too */
7825 #if ENABLE_HUSH_CASE
7826 if (rword == RES_CASE) {
7827 case_word = expand_strvec_to_string(pi->cmds->argv);
7830 if (rword == RES_MATCH) {
7833 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7835 /* all prev words didn't match, does this one match? */
7836 argv = pi->cmds->argv;
7838 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7839 /* TODO: which FNM_xxx flags to use? */
7840 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7842 if (cond_code == 0) { /* match! we will execute this branch */
7843 free(case_word); /* make future "word)" stop */
7851 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7853 continue; /* not matched yet, skip this pipe */
7856 /* Just pressing <enter> in shell should check for jobs.
7857 * OTOH, in non-interactive shell this is useless
7858 * and only leads to extra job checks */
7859 if (pi->num_cmds == 0) {
7860 if (G_interactive_fd)
7861 goto check_jobs_and_continue;
7865 /* After analyzing all keywords and conditions, we decided
7866 * to execute this pipe. NB: have to do checkjobs(NULL)
7867 * after run_pipe to collect any background children,
7868 * even if list execution is to be stopped. */
7869 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7872 #if ENABLE_HUSH_LOOPS
7873 G.flag_break_continue = 0;
7875 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7877 /* We ran a builtin, function, or group.
7878 * rcode is already known
7879 * and we don't need to wait for anything. */
7880 G.last_exitcode = rcode;
7881 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7882 check_and_run_traps();
7883 #if ENABLE_HUSH_LOOPS
7884 /* Was it "break" or "continue"? */
7885 if (G.flag_break_continue) {
7886 smallint fbc = G.flag_break_continue;
7887 /* We might fall into outer *loop*,
7888 * don't want to break it too */
7890 G.depth_break_continue--;
7891 if (G.depth_break_continue == 0)
7892 G.flag_break_continue = 0;
7893 /* else: e.g. "continue 2" should *break* once, *then* continue */
7894 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7895 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7899 /* "continue": simulate end of loop */
7904 if (G_flag_return_in_progress == 1) {
7908 } else if (pi->followup == PIPE_BG) {
7909 /* What does bash do with attempts to background builtins? */
7910 /* even bash 3.2 doesn't do that well with nested bg:
7911 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7912 * I'm NOT treating inner &'s as jobs */
7913 check_and_run_traps();
7915 if (G.run_list_level == 1)
7918 /* Last command's pid goes to $! */
7919 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7920 G.last_exitcode = rcode = EXIT_SUCCESS;
7921 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7924 if (G.run_list_level == 1 && G_interactive_fd) {
7925 /* Waits for completion, then fg's main shell */
7926 rcode = checkjobs_and_fg_shell(pi);
7927 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7928 check_and_run_traps();
7931 { /* This one just waits for completion */
7932 rcode = checkjobs(pi);
7933 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7934 check_and_run_traps();
7936 G.last_exitcode = rcode;
7940 /* Analyze how result affects subsequent commands */
7942 if (rword == RES_IF || rword == RES_ELIF)
7945 check_jobs_and_continue:
7947 dont_check_jobs_but_continue: ;
7948 #if ENABLE_HUSH_LOOPS
7949 /* Beware of "while false; true; do ..."! */
7951 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
7952 /* check for RES_DONE is needed for "while ...; do \n done" case */
7954 if (rword == RES_WHILE) {
7956 /* "while false; do...done" - exitcode 0 */
7957 G.last_exitcode = rcode = EXIT_SUCCESS;
7958 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7962 if (rword == RES_UNTIL) {
7964 debug_printf_exec(": until expr is true: breaking\n");
7975 #if ENABLE_HUSH_LOOPS
7980 #if ENABLE_HUSH_CASE
7984 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7988 /* Select which version we will use */
7989 static int run_and_free_list(struct pipe *pi)
7992 debug_printf_exec("run_and_free_list entered\n");
7993 if (!G.o_opt[OPT_O_NOEXEC]) {
7994 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7995 rcode = run_list(pi);
7997 /* free_pipe_list has the side effect of clearing memory.
7998 * In the long run that function can be merged with run_list,
7999 * but doing that now would hobble the debugging effort. */
8001 debug_printf_exec("run_and_free_list return %d\n", rcode);
8006 static void install_sighandlers(unsigned mask)
8008 sighandler_t old_handler;
8010 while ((mask >>= 1) != 0) {
8014 old_handler = install_sighandler(sig, pick_sighandler(sig));
8015 /* POSIX allows shell to re-enable SIGCHLD
8016 * even if it was SIG_IGN on entry.
8017 * Therefore we skip IGN check for it:
8021 if (old_handler == SIG_IGN) {
8022 /* oops... restore back to IGN, and record this fact */
8023 install_sighandler(sig, old_handler);
8025 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8027 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8032 /* Called a few times only (or even once if "sh -c") */
8033 static void install_special_sighandlers(void)
8037 /* Which signals are shell-special? */
8038 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8039 if (G_interactive_fd) {
8040 mask |= SPECIAL_INTERACTIVE_SIGS;
8041 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8042 mask |= SPECIAL_JOBSTOP_SIGS;
8044 /* Careful, do not re-install handlers we already installed */
8045 if (G.special_sig_mask != mask) {
8046 unsigned diff = mask & ~G.special_sig_mask;
8047 G.special_sig_mask = mask;
8048 install_sighandlers(diff);
8054 /* Set handlers to restore tty pgrp and exit */
8055 static void install_fatal_sighandlers(void)
8059 /* We will restore tty pgrp on these signals */
8061 + (1 << SIGILL ) * HUSH_DEBUG
8062 + (1 << SIGFPE ) * HUSH_DEBUG
8063 + (1 << SIGBUS ) * HUSH_DEBUG
8064 + (1 << SIGSEGV) * HUSH_DEBUG
8065 + (1 << SIGTRAP) * HUSH_DEBUG
8067 /* bash 3.2 seems to handle these just like 'fatal' ones */
8070 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8071 * if we aren't interactive... but in this case
8072 * we never want to restore pgrp on exit, and this fn is not called
8074 /*+ (1 << SIGHUP )*/
8075 /*+ (1 << SIGTERM)*/
8076 /*+ (1 << SIGINT )*/
8078 G_fatal_sig_mask = mask;
8080 install_sighandlers(mask);
8084 static int set_mode(int state, char mode, const char *o_opt)
8089 G.o_opt[OPT_O_NOEXEC] = state;
8092 IF_HUSH_MODE_X(G_x_mode = state;)
8096 /* "set -+o" without parameter.
8097 * in bash, set -o produces this output:
8101 * We always use the second form.
8103 const char *p = o_opt_strings;
8106 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8112 idx = index_in_strings(o_opt_strings, o_opt);
8114 G.o_opt[idx] = state;
8118 return EXIT_FAILURE;
8120 return EXIT_SUCCESS;
8123 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8124 int hush_main(int argc, char **argv)
8127 OPT_login = (1 << 0),
8131 unsigned builtin_argc;
8133 struct variable *cur_var;
8134 struct variable *shell_ver;
8137 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8138 G.last_exitcode = EXIT_SUCCESS;
8140 #if ENABLE_HUSH_FAST
8141 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8144 G.argv0_for_re_execing = argv[0];
8146 /* Deal with HUSH_VERSION */
8147 shell_ver = xzalloc(sizeof(*shell_ver));
8148 shell_ver->flg_export = 1;
8149 shell_ver->flg_read_only = 1;
8150 /* Code which handles ${var<op>...} needs writable values for all variables,
8151 * therefore we xstrdup: */
8152 shell_ver->varstr = xstrdup(hush_version_str);
8153 /* Create shell local variables from the values
8154 * currently living in the environment */
8155 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8156 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8157 G.top_var = shell_ver;
8158 cur_var = G.top_var;
8161 char *value = strchr(*e, '=');
8162 if (value) { /* paranoia */
8163 cur_var->next = xzalloc(sizeof(*cur_var));
8164 cur_var = cur_var->next;
8165 cur_var->varstr = *e;
8166 cur_var->max_len = strlen(*e);
8167 cur_var->flg_export = 1;
8171 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8172 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8173 putenv(shell_ver->varstr);
8176 set_pwd_var(/*exp:*/ 1);
8178 #if ENABLE_HUSH_BASH_COMPAT
8179 /* Set (but not export) HOSTNAME unless already set */
8180 if (!get_local_var_value("HOSTNAME")) {
8183 set_local_var_from_halves("HOSTNAME", uts.nodename);
8185 /* bash also exports SHLVL and _,
8186 * and sets (but doesn't export) the following variables:
8188 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8189 * BASH_VERSION='3.2.0(1)-release'
8191 * MACHTYPE=i386-pc-linux-gnu
8193 * PPID=<NNNNN> - we also do it elsewhere
8204 * PIPESTATUS=([0]="0")
8205 * HISTFILE=/<xxx>/.bash_history
8209 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8211 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8222 #if ENABLE_FEATURE_EDITING
8223 G.line_input_state = new_line_input_t(FOR_SHELL);
8226 /* Initialize some more globals to non-zero values */
8227 cmdedit_update_prompt();
8229 die_func = restore_ttypgrp_and__exit;
8231 /* Shell is non-interactive at first. We need to call
8232 * install_special_sighandlers() if we are going to execute "sh <script>",
8233 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8234 * If we later decide that we are interactive, we run install_special_sighandlers()
8235 * in order to intercept (more) signals.
8239 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8240 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8243 opt = getopt(argc, argv, "+c:xinsl"
8246 # if ENABLE_HUSH_FUNCTIONS
8256 * sh ... -c 'script'
8257 * sh ... -c 'script' ARG0 [ARG1...]
8258 * On NOMMU, if builtin_argc != 0,
8259 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8260 * "" needs to be replaced with NULL
8261 * and BARGV vector fed to builtin function.
8262 * Note: the form without ARG0 never happens:
8263 * sh ... -c 'builtin' BARGV... ""
8266 G.root_pid = getpid();
8267 G.root_ppid = getppid();
8269 G.global_argv = argv + optind;
8270 G.global_argc = argc - optind;
8272 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8273 const struct built_in_command *x;
8275 install_special_sighandlers();
8276 x = find_builtin(optarg);
8277 if (x) { /* paranoia */
8278 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8279 G.global_argv += builtin_argc;
8280 G.global_argv[-1] = NULL; /* replace "" */
8282 G.last_exitcode = x->b_function(argv + optind - 1);
8286 if (!G.global_argv[0]) {
8287 /* -c 'script' (no params): prevent empty $0 */
8288 G.global_argv--; /* points to argv[i] of 'script' */
8289 G.global_argv[0] = argv[0];
8291 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8292 install_special_sighandlers();
8293 parse_and_run_string(optarg);
8296 /* Well, we cannot just declare interactiveness,
8297 * we have to have some stuff (ctty, etc) */
8298 /* G_interactive_fd++; */
8301 /* "-s" means "read from stdin", but this is how we always
8302 * operate, so simply do nothing here. */
8308 case '<': /* "big heredoc" support */
8309 full_write1_str(optarg);
8312 unsigned long long empty_trap_mask;
8314 G.root_pid = bb_strtou(optarg, &optarg, 16);
8316 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8318 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8320 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8322 builtin_argc = bb_strtou(optarg, &optarg, 16);
8324 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8325 if (empty_trap_mask != 0) {
8327 install_special_sighandlers();
8328 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8329 for (sig = 1; sig < NSIG; sig++) {
8330 if (empty_trap_mask & (1LL << sig)) {
8331 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8332 install_sighandler(sig, SIG_IGN);
8336 # if ENABLE_HUSH_LOOPS
8338 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8344 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8346 # if ENABLE_HUSH_FUNCTIONS
8348 struct function *funcp = new_function(optarg);
8349 /* funcp->name is already set to optarg */
8350 /* funcp->body is set to NULL. It's a special case. */
8351 funcp->body_as_string = argv[optind];
8359 if (set_mode(1, opt, NULL) == 0) /* no error */
8363 fprintf(stderr, "Usage: sh [FILE]...\n"
8364 " or: sh -c command [args]...\n\n");
8370 } /* option parsing loop */
8372 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8373 G.global_argc = argc - (optind - 1);
8374 G.global_argv = argv + (optind - 1);
8375 G.global_argv[0] = argv[0];
8378 G.root_pid = getpid();
8379 G.root_ppid = getppid();
8382 /* If we are login shell... */
8383 if (flags & OPT_login) {
8385 debug_printf("sourcing /etc/profile\n");
8386 input = fopen_for_read("/etc/profile");
8387 if (input != NULL) {
8388 remember_FILE(input);
8389 install_special_sighandlers();
8390 parse_and_run_file(input);
8391 fclose_and_forget(input);
8393 /* bash: after sourcing /etc/profile,
8394 * tries to source (in the given order):
8395 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8396 * stopping on first found. --noprofile turns this off.
8397 * bash also sources ~/.bash_logout on exit.
8398 * If called as sh, skips .bash_XXX files.
8402 if (G.global_argv[1]) {
8405 * "bash <script>" (which is never interactive (unless -i?))
8406 * sources $BASH_ENV here (without scanning $PATH).
8407 * If called as sh, does the same but with $ENV.
8411 debug_printf("running script '%s'\n", G.global_argv[0]);
8412 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8413 input = xfopen_for_read(G.global_argv[0]);
8414 xfunc_error_retval = 1;
8415 remember_FILE(input);
8416 install_special_sighandlers();
8417 parse_and_run_file(input);
8418 #if ENABLE_FEATURE_CLEAN_UP
8419 fclose_and_forget(input);
8424 /* Up to here, shell was non-interactive. Now it may become one.
8425 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8428 /* A shell is interactive if the '-i' flag was given,
8429 * or if all of the following conditions are met:
8431 * no arguments remaining or the -s flag given
8432 * standard input is a terminal
8433 * standard output is a terminal
8434 * Refer to Posix.2, the description of the 'sh' utility.
8437 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8438 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8439 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8440 if (G_saved_tty_pgrp < 0)
8441 G_saved_tty_pgrp = 0;
8443 /* try to dup stdin to high fd#, >= 255 */
8444 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8445 if (G_interactive_fd < 0) {
8446 /* try to dup to any fd */
8447 G_interactive_fd = dup(STDIN_FILENO);
8448 if (G_interactive_fd < 0) {
8450 G_interactive_fd = 0;
8451 G_saved_tty_pgrp = 0;
8454 // TODO: track & disallow any attempts of user
8455 // to (inadvertently) close/redirect G_interactive_fd
8457 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8458 if (G_interactive_fd) {
8459 close_on_exec_on(G_interactive_fd);
8461 if (G_saved_tty_pgrp) {
8462 /* If we were run as 'hush &', sleep until we are
8463 * in the foreground (tty pgrp == our pgrp).
8464 * If we get started under a job aware app (like bash),
8465 * make sure we are now in charge so we don't fight over
8466 * who gets the foreground */
8468 pid_t shell_pgrp = getpgrp();
8469 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8470 if (G_saved_tty_pgrp == shell_pgrp)
8472 /* send TTIN to ourself (should stop us) */
8473 kill(- shell_pgrp, SIGTTIN);
8477 /* Install more signal handlers */
8478 install_special_sighandlers();
8480 if (G_saved_tty_pgrp) {
8481 /* Set other signals to restore saved_tty_pgrp */
8482 install_fatal_sighandlers();
8483 /* Put ourselves in our own process group
8484 * (bash, too, does this only if ctty is available) */
8485 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8486 /* Grab control of the terminal */
8487 tcsetpgrp(G_interactive_fd, getpid());
8489 enable_restore_tty_pgrp_on_exit();
8491 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8493 const char *hp = get_local_var_value("HISTFILE");
8495 hp = get_local_var_value("HOME");
8497 hp = concat_path_file(hp, ".hush_history");
8502 G.line_input_state->hist_file = hp;
8503 //set_local_var(xasprintf("HISTFILE=%s", ...));
8505 # if ENABLE_FEATURE_SH_HISTFILESIZE
8506 hp = get_local_var_value("HISTFILESIZE");
8507 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8512 install_special_sighandlers();
8514 #elif ENABLE_HUSH_INTERACTIVE
8515 /* No job control compiled in, only prompt/line editing */
8516 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8517 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8518 if (G_interactive_fd < 0) {
8519 /* try to dup to any fd */
8520 G_interactive_fd = dup(STDIN_FILENO);
8521 if (G_interactive_fd < 0)
8523 G_interactive_fd = 0;
8526 if (G_interactive_fd) {
8527 close_on_exec_on(G_interactive_fd);
8529 install_special_sighandlers();
8531 /* We have interactiveness code disabled */
8532 install_special_sighandlers();
8535 * if interactive but not a login shell, sources ~/.bashrc
8536 * (--norc turns this off, --rcfile <file> overrides)
8539 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8540 /* note: ash and hush share this string */
8541 printf("\n\n%s %s\n"
8542 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8545 "hush - the humble shell"
8549 parse_and_run_file(stdin);
8552 hush_exit(G.last_exitcode);
8557 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8558 int msh_main(int argc, char **argv)
8560 bb_error_msg("msh is deprecated, please use hush instead");
8561 return hush_main(argc, argv);
8569 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8574 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8581 return applet_main_func(argc, argv - argc);
8584 static int FAST_FUNC builtin_test(char **argv)
8586 return run_applet_main(argv, test_main);
8589 static int FAST_FUNC builtin_echo(char **argv)
8591 return run_applet_main(argv, echo_main);
8595 static int FAST_FUNC builtin_printf(char **argv)
8597 return run_applet_main(argv, printf_main);
8601 static char **skip_dash_dash(char **argv)
8604 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8609 static int FAST_FUNC builtin_eval(char **argv)
8611 int rcode = EXIT_SUCCESS;
8613 argv = skip_dash_dash(argv);
8615 char *str = expand_strvec_to_string(argv);
8617 * eval "echo Hi; done" ("done" is syntax error):
8618 * "echo Hi" will not execute too.
8620 parse_and_run_string(str);
8622 rcode = G.last_exitcode;
8627 static int FAST_FUNC builtin_cd(char **argv)
8631 argv = skip_dash_dash(argv);
8633 if (newdir == NULL) {
8634 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8635 * bash says "bash: cd: HOME not set" and does nothing
8638 const char *home = get_local_var_value("HOME");
8639 newdir = home ? home : "/";
8641 if (chdir(newdir)) {
8642 /* Mimic bash message exactly */
8643 bb_perror_msg("cd: %s", newdir);
8644 return EXIT_FAILURE;
8646 /* Read current dir (get_cwd(1) is inside) and set PWD.
8647 * Note: do not enforce exporting. If PWD was unset or unexported,
8648 * set it again, but do not export. bash does the same.
8650 set_pwd_var(/*exp:*/ 0);
8651 return EXIT_SUCCESS;
8654 static int FAST_FUNC builtin_exec(char **argv)
8656 argv = skip_dash_dash(argv);
8657 if (argv[0] == NULL)
8658 return EXIT_SUCCESS; /* bash does this */
8660 /* Careful: we can end up here after [v]fork. Do not restore
8661 * tty pgrp then, only top-level shell process does that */
8662 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8663 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8665 /* TODO: if exec fails, bash does NOT exit! We do.
8666 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8667 * and tcsetpgrp, and this is inherently racy.
8669 execvp_or_die(argv);
8672 static int FAST_FUNC builtin_exit(char **argv)
8674 debug_printf_exec("%s()\n", __func__);
8676 /* interactive bash:
8677 * # trap "echo EEE" EXIT
8680 * There are stopped jobs.
8681 * (if there are _stopped_ jobs, running ones don't count)
8684 * EEE (then bash exits)
8686 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8689 /* note: EXIT trap is run by hush_exit */
8690 argv = skip_dash_dash(argv);
8691 if (argv[0] == NULL)
8692 hush_exit(G.last_exitcode);
8693 /* mimic bash: exit 123abc == exit 255 + error msg */
8694 xfunc_error_retval = 255;
8695 /* bash: exit -2 == exit 254, no error msg */
8696 hush_exit(xatoi(argv[0]) & 0xff);
8699 static void print_escaped(const char *s)
8704 const char *p = strchrnul(s, '\'');
8705 /* print 'xxxx', possibly just '' */
8706 printf("'%.*s'", (int)(p - s), s);
8711 /* s points to '; print "'''...'''" */
8713 do putchar('\''); while (*++s == '\'');
8718 #if !ENABLE_HUSH_LOCAL
8719 #define helper_export_local(argv, exp, lvl) \
8720 helper_export_local(argv, exp)
8722 static void helper_export_local(char **argv, int exp, int lvl)
8726 char *name_end = strchrnul(name, '=');
8728 /* So far we do not check that name is valid (TODO?) */
8730 if (*name_end == '\0') {
8731 struct variable *var, **vpp;
8733 vpp = get_ptr_to_local_var(name, name_end - name);
8734 var = vpp ? *vpp : NULL;
8736 if (exp == -1) { /* unexporting? */
8737 /* export -n NAME (without =VALUE) */
8739 var->flg_export = 0;
8740 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8742 } /* else: export -n NOT_EXISTING_VAR: no-op */
8745 if (exp == 1) { /* exporting? */
8746 /* export NAME (without =VALUE) */
8748 var->flg_export = 1;
8749 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8750 putenv(var->varstr);
8754 #if ENABLE_HUSH_LOCAL
8755 if (exp == 0 /* local? */
8756 && var && var->func_nest_level == lvl
8758 /* "local x=abc; ...; local x" - ignore second local decl */
8762 /* Exporting non-existing variable.
8763 * bash does not put it in environment,
8764 * but remembers that it is exported,
8765 * and does put it in env when it is set later.
8766 * We just set it to "" and export. */
8767 /* Or, it's "local NAME" (without =VALUE).
8768 * bash sets the value to "". */
8769 name = xasprintf("%s=", name);
8771 /* (Un)exporting/making local NAME=VALUE */
8772 name = xstrdup(name);
8774 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8778 static int FAST_FUNC builtin_export(char **argv)
8780 unsigned opt_unexport;
8782 #if ENABLE_HUSH_EXPORT_N
8783 /* "!": do not abort on errors */
8784 opt_unexport = getopt32(argv, "!n");
8785 if (opt_unexport == (uint32_t)-1)
8786 return EXIT_FAILURE;
8793 if (argv[0] == NULL) {
8800 /* ash emits: export VAR='VAL'
8801 * bash: declare -x VAR="VAL"
8802 * we follow ash example */
8803 const char *s = *e++;
8804 const char *p = strchr(s, '=');
8806 if (!p) /* wtf? take next variable */
8809 printf("export %.*s", (int)(p - s) + 1, s);
8810 print_escaped(p + 1);
8814 /*fflush_all(); - done after each builtin anyway */
8816 return EXIT_SUCCESS;
8819 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8821 return EXIT_SUCCESS;
8824 #if ENABLE_HUSH_LOCAL
8825 static int FAST_FUNC builtin_local(char **argv)
8827 if (G.func_nest_level == 0) {
8828 bb_error_msg("%s: not in a function", argv[0]);
8829 return EXIT_FAILURE; /* bash compat */
8831 helper_export_local(argv, 0, G.func_nest_level);
8832 return EXIT_SUCCESS;
8836 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8837 static int FAST_FUNC builtin_unset(char **argv)
8842 /* "!": do not abort on errors */
8843 /* "+": stop at 1st non-option */
8844 opts = getopt32(argv, "!+vf");
8845 if (opts == (unsigned)-1)
8846 return EXIT_FAILURE;
8848 bb_error_msg("unset: -v and -f are exclusive");
8849 return EXIT_FAILURE;
8855 if (!(opts & 2)) { /* not -f */
8856 if (unset_local_var(*argv)) {
8857 /* unset <nonexistent_var> doesn't fail.
8858 * Error is when one tries to unset RO var.
8859 * Message was printed by unset_local_var. */
8863 #if ENABLE_HUSH_FUNCTIONS
8873 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8874 * built-in 'set' handler
8876 * set [-abCefhmnuvx] [-o option] [argument...]
8877 * set [+abCefhmnuvx] [+o option] [argument...]
8878 * set -- [argument...]
8881 * Implementations shall support the options in both their hyphen and
8882 * plus-sign forms. These options can also be specified as options to sh.
8884 * Write out all variables and their values: set
8885 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8886 * Turn on the -x and -v options: set -xv
8887 * Unset all positional parameters: set --
8888 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8889 * Set the positional parameters to the expansion of x, even if x expands
8890 * with a leading '-' or '+': set -- $x
8892 * So far, we only support "set -- [argument...]" and some of the short names.
8894 static int FAST_FUNC builtin_set(char **argv)
8897 char **pp, **g_argv;
8898 char *arg = *++argv;
8902 for (e = G.top_var; e; e = e->next)
8904 return EXIT_SUCCESS;
8908 if (strcmp(arg, "--") == 0) {
8912 if (arg[0] != '+' && arg[0] != '-')
8914 for (n = 1; arg[n]; ++n) {
8915 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8917 if (arg[n] == 'o' && argv[1])
8920 } while ((arg = *++argv) != NULL);
8921 /* Now argv[0] is 1st argument */
8924 return EXIT_SUCCESS;
8927 /* NB: G.global_argv[0] ($0) is never freed/changed */
8928 g_argv = G.global_argv;
8929 if (G.global_args_malloced) {
8935 G.global_args_malloced = 1;
8936 pp = xzalloc(sizeof(pp[0]) * 2);
8937 pp[0] = g_argv[0]; /* retain $0 */
8940 /* This realloc's G.global_argv */
8941 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8948 return EXIT_SUCCESS;
8950 /* Nothing known, so abort */
8952 bb_error_msg("set: %s: invalid option", arg);
8953 return EXIT_FAILURE;
8956 static int FAST_FUNC builtin_shift(char **argv)
8959 argv = skip_dash_dash(argv);
8963 if (n >= 0 && n < G.global_argc) {
8964 if (G.global_args_malloced) {
8967 free(G.global_argv[m++]);
8970 memmove(&G.global_argv[1], &G.global_argv[n+1],
8971 G.global_argc * sizeof(G.global_argv[0]));
8972 return EXIT_SUCCESS;
8974 return EXIT_FAILURE;
8977 /* Interruptibility of read builtin in bash
8978 * (tested on bash-4.2.8 by sending signals (not by ^C)):
8980 * Empty trap makes read ignore corresponding signal, for any signal.
8983 * - terminates non-interactive shell;
8984 * - interrupts read in interactive shell;
8985 * if it has non-empty trap:
8986 * - executes trap and returns to command prompt in interactive shell;
8987 * - executes trap and returns to read in non-interactive shell;
8989 * - is ignored (does not interrupt) read in interactive shell;
8990 * - terminates non-interactive shell;
8991 * if it has non-empty trap:
8992 * - executes trap and returns to read;
8994 * - terminates shell (regardless of interactivity);
8995 * if it has non-empty trap:
8996 * - executes trap and returns to read;
8998 static int FAST_FUNC builtin_read(char **argv)
9008 /* "!": do not abort on errors.
9009 * Option string must start with "sr" to match BUILTIN_READ_xxx
9011 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9012 if (read_flags == (uint32_t)-1)
9013 return EXIT_FAILURE;
9015 ifs = get_local_var_value("IFS"); /* can be NULL */
9018 r = shell_builtin_read(set_local_var_from_halves,
9028 if ((uintptr_t)r == 1 && errno == EINTR) {
9029 unsigned sig = check_and_run_traps();
9030 if (sig && sig != SIGINT)
9034 if ((uintptr_t)r > 1) {
9035 bb_error_msg("%s", r);
9036 r = (char*)(uintptr_t)1;
9039 return (uintptr_t)r;
9042 static int FAST_FUNC builtin_trap(char **argv)
9048 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
9053 /* No args: print all trapped */
9054 for (i = 0; i < NSIG; ++i) {
9057 print_escaped(G.traps[i]);
9058 /* note: bash adds "SIG", but only if invoked
9059 * as "bash". If called as "sh", or if set -o posix,
9060 * then it prints short signal names.
9061 * We are printing short names: */
9062 printf(" %s\n", get_signame(i));
9065 /*fflush_all(); - done after each builtin anyway */
9066 return EXIT_SUCCESS;
9070 /* If first arg is a number: reset all specified signals */
9071 sig = bb_strtou(*argv, NULL, 10);
9077 sighandler_t handler;
9079 sig = get_signum(*argv++);
9080 if (sig < 0 || sig >= NSIG) {
9082 /* Mimic bash message exactly */
9083 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9088 G.traps[sig] = xstrdup(new_cmd);
9090 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9091 get_signame(sig), sig, G.traps[sig]);
9093 /* There is no signal for 0 (EXIT) */
9098 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9100 /* We are removing trap handler */
9101 handler = pick_sighandler(sig);
9102 install_sighandler(sig, handler);
9107 if (!argv[1]) { /* no second arg */
9108 bb_error_msg("trap: invalid arguments");
9109 return EXIT_FAILURE;
9112 /* First arg is "-": reset all specified to default */
9113 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9114 /* Everything else: set arg as signal handler
9115 * (includes "" case, which ignores signal) */
9116 if (argv[0][0] == '-') {
9117 if (argv[0][1] == '\0') { /* "-" */
9118 /* new_cmd remains NULL: "reset these sigs" */
9121 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9124 /* else: "-something", no special meaning */
9129 goto process_sig_list;
9132 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9133 static int FAST_FUNC builtin_type(char **argv)
9135 int ret = EXIT_SUCCESS;
9141 if (0) {} /* make conditional compile easier below */
9142 /*else if (find_alias(*argv))
9143 type = "an alias";*/
9144 #if ENABLE_HUSH_FUNCTIONS
9145 else if (find_function(*argv))
9146 type = "a function";
9148 else if (find_builtin(*argv))
9149 type = "a shell builtin";
9150 else if ((path = find_in_path(*argv)) != NULL)
9153 bb_error_msg("type: %s: not found", *argv);
9158 printf("%s is %s\n", *argv, type);
9166 /* built-in 'fg' and 'bg' handler */
9167 static int FAST_FUNC builtin_fg_bg(char **argv)
9172 if (!G_interactive_fd)
9173 return EXIT_FAILURE;
9175 /* If they gave us no args, assume they want the last backgrounded task */
9177 for (pi = G.job_list; pi; pi = pi->next) {
9178 if (pi->jobid == G.last_jobid) {
9182 bb_error_msg("%s: no current job", argv[0]);
9183 return EXIT_FAILURE;
9185 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
9186 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
9187 return EXIT_FAILURE;
9189 for (pi = G.job_list; pi; pi = pi->next) {
9190 if (pi->jobid == jobnum) {
9194 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
9195 return EXIT_FAILURE;
9197 /* TODO: bash prints a string representation
9198 * of job being foregrounded (like "sleep 1 | cat") */
9199 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9200 /* Put the job into the foreground. */
9201 tcsetpgrp(G_interactive_fd, pi->pgrp);
9204 /* Restart the processes in the job */
9205 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9206 for (i = 0; i < pi->num_cmds; i++) {
9207 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9209 pi->stopped_cmds = 0;
9211 i = kill(- pi->pgrp, SIGCONT);
9213 if (errno == ESRCH) {
9214 delete_finished_bg_job(pi);
9215 return EXIT_SUCCESS;
9217 bb_perror_msg("kill (SIGCONT)");
9220 if (argv[0][0] == 'f') {
9222 return checkjobs_and_fg_shell(pi);
9224 return EXIT_SUCCESS;
9228 #if ENABLE_HUSH_HELP
9229 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9231 const struct built_in_command *x;
9234 "Built-in commands:\n"
9235 "------------------\n");
9236 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9238 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9240 return EXIT_SUCCESS;
9244 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9245 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9247 show_history(G.line_input_state);
9248 return EXIT_SUCCESS;
9253 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9256 const char *status_string;
9258 for (job = G.job_list; job; job = job->next) {
9259 if (job->alive_cmds == job->stopped_cmds)
9260 status_string = "Stopped";
9262 status_string = "Running";
9264 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9266 return EXIT_SUCCESS;
9271 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9276 # ifdef M_TRIM_THRESHOLD
9277 /* Optional. Reduces probability of false positives */
9280 /* Crude attempt to find where "free memory" starts,
9281 * sans fragmentation. */
9283 l = (unsigned long)p;
9286 if (l < (unsigned long)p) l = (unsigned long)p;
9292 struct mallinfo mi = mallinfo();
9293 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9294 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9298 if (!G.memleak_value)
9299 G.memleak_value = l;
9301 l -= G.memleak_value;
9308 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9313 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9316 return EXIT_SUCCESS;
9319 static int FAST_FUNC builtin_source(char **argv)
9321 char *arg_path, *filename;
9324 #if ENABLE_HUSH_FUNCTIONS
9328 argv = skip_dash_dash(argv);
9331 /* bash says: "bash: .: filename argument required" */
9332 return 2; /* bash compat */
9335 if (!strchr(filename, '/')) {
9336 arg_path = find_in_path(filename);
9338 filename = arg_path;
9340 input = remember_FILE(fopen_or_warn(filename, "r"));
9343 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9344 /* POSIX: non-interactive shell should abort here,
9345 * not merely fail. So far no one complained :)
9347 return EXIT_FAILURE;
9350 #if ENABLE_HUSH_FUNCTIONS
9351 sv_flg = G_flag_return_in_progress;
9352 /* "we are inside sourced file, ok to use return" */
9353 G_flag_return_in_progress = -1;
9356 save_and_replace_G_args(&sv, argv);
9358 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9359 G.last_exitcode = 0;
9360 parse_and_run_file(input);
9361 fclose_and_forget(input);
9364 restore_G_args(&sv, argv);
9365 #if ENABLE_HUSH_FUNCTIONS
9366 G_flag_return_in_progress = sv_flg;
9369 return G.last_exitcode;
9372 static int FAST_FUNC builtin_umask(char **argv)
9379 argv = skip_dash_dash(argv);
9381 mode_t old_mask = mask;
9383 /* numeric umasks are taken as-is */
9384 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9385 if (!isdigit(argv[0][0]))
9387 mask = bb_parse_mode(argv[0], mask);
9388 if (!isdigit(argv[0][0]))
9390 if ((unsigned)mask > 0777) {
9393 * bash: umask: 'q': invalid symbolic mode operator
9394 * bash: umask: 999: octal number out of range
9396 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9401 printf("%04o\n", (unsigned) mask);
9402 /* fall through and restore mask which we set to 0 */
9406 return !rc; /* rc != 0 - success */
9409 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9410 static int FAST_FUNC builtin_wait(char **argv)
9412 int ret = EXIT_SUCCESS;
9415 argv = skip_dash_dash(argv);
9416 if (argv[0] == NULL) {
9417 /* Don't care about wait results */
9418 /* Note 1: must wait until there are no more children */
9419 /* Note 2: must be interruptible */
9421 * $ sleep 3 & sleep 6 & wait
9426 * $ sleep 3 & sleep 6 & wait
9430 * ^C <-- after ~4 sec from keyboard
9435 sigset_t oldset, allsigs;
9437 /* waitpid is not interruptible by SA_RESTARTed
9438 * signals which we use. Thus, this ugly dance:
9441 /* Make sure possible SIGCHLD is stored in kernel's
9442 * pending signal mask before we call waitpid.
9443 * Or else we may race with SIGCHLD, lose it,
9444 * and get stuck in sigwaitinfo...
9446 sigfillset(&allsigs);
9447 sigprocmask(SIG_SETMASK, &allsigs, &oldset);
9449 if (!sigisemptyset(&G.pending_set)) {
9450 /* Crap! we raced with some signal! */
9455 checkjobs(NULL); /* waitpid(WNOHANG) inside */
9456 if (errno == ECHILD) {
9457 sigprocmask(SIG_SETMASK, &oldset, NULL);
9461 /* Wait for SIGCHLD or any other signal */
9462 //sig = sigwaitinfo(&allsigs, NULL);
9463 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9464 /* Note: sigsuspend invokes signal handler */
9465 sigsuspend(&oldset);
9467 sigprocmask(SIG_SETMASK, &oldset, NULL);
9469 /* So, did we get a signal? */
9471 // raise(sig); /* run handler */
9472 sig = check_and_run_traps();
9473 if (sig /*&& sig != SIGCHLD - always true */) {
9478 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9483 /* This is probably buggy wrt interruptible-ness */
9485 pid_t pid = bb_strtou(*argv, NULL, 10);
9487 /* mimic bash message */
9488 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9489 return EXIT_FAILURE;
9491 if (waitpid(pid, &status, 0) == pid) {
9492 ret = WEXITSTATUS(status);
9493 if (WIFSIGNALED(status))
9494 ret = 128 + WTERMSIG(status);
9496 bb_perror_msg("wait %s", *argv);
9505 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9506 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9509 def = bb_strtou(argv[1], NULL, 10);
9510 if (errno || def < def_min || argv[2]) {
9511 bb_error_msg("%s: bad arguments", argv[0]);
9519 #if ENABLE_HUSH_LOOPS
9520 static int FAST_FUNC builtin_break(char **argv)
9523 if (G.depth_of_loop == 0) {
9524 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9525 /* if we came from builtin_continue(), need to undo "= 1" */
9526 G.flag_break_continue = 0;
9527 return EXIT_SUCCESS; /* bash compat */
9529 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9531 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9532 if (depth == UINT_MAX)
9533 G.flag_break_continue = BC_BREAK;
9534 if (G.depth_of_loop < depth)
9535 G.depth_break_continue = G.depth_of_loop;
9537 return EXIT_SUCCESS;
9540 static int FAST_FUNC builtin_continue(char **argv)
9542 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9543 return builtin_break(argv);
9547 #if ENABLE_HUSH_FUNCTIONS
9548 static int FAST_FUNC builtin_return(char **argv)
9552 if (G_flag_return_in_progress != -1) {
9553 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9554 return EXIT_FAILURE; /* bash compat */
9557 G_flag_return_in_progress = 1;
9560 * out of range: wraps around at 256, does not error out
9561 * non-numeric param:
9562 * f() { false; return qwe; }; f; echo $?
9563 * bash: return: qwe: numeric argument required <== we do this
9564 * 255 <== we also do this
9566 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);