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>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
41 * grep for "TODO" and fix (some of them are easy)
42 * special variables (done: PWD, PPID, RANDOM)
45 * follow IFS rules more precisely, including update semantics
46 * builtins mandated by standards we don't support:
47 * [un]alias, command, fc, getopts, newgrp, readonly, times
48 * make complex ${var%...} constructs support optional
49 * make here documents optional
52 * redirection of stdout+stderr: &> and >&
53 * brace expansion: one/{two,three,four}
54 * reserved words: function select
55 * advanced test: [[ ]]
56 * process substitution: <(list) and >(list)
59 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
60 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
61 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
63 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
64 * This is exactly equivalent to let "EXPR".
65 * $[EXPR]: synonym for $((EXPR))
66 * export builtin should be special, its arguments are assignments
67 * and therefore expansion of them should be "one-word" expansion:
68 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
70 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
71 * ls: cannot access i=a: No such file or directory
72 * ls: cannot access b: No such file or directory
73 * Note1: same applies to local builtin.
74 * Note2: bash 3.2.33(1) does this only if export word itself
76 * $ export i=`echo 'aaa bbb'`; echo "$i"
78 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
81 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
83 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
84 #include <malloc.h> /* for malloc_trim */
86 /* #include <dmalloc.h> */
91 #include "shell_common.h"
94 #if ENABLE_HUSH_RANDOM_SUPPORT
97 # define CLEAR_RANDOM_T(rnd) ((void)0)
100 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
103 //applet:IF_HUSH(APPLET(hush, _BB_DIR_BIN, _BB_SUID_DROP))
104 //applet:IF_MSH(APPLET(msh, _BB_DIR_BIN, _BB_SUID_DROP))
105 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, _BB_DIR_BIN, _BB_SUID_DROP, sh))
106 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, _BB_DIR_BIN, _BB_SUID_DROP, bash))
108 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
109 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
112 //config: bool "hush"
115 //config: hush is a small shell (25k). It handles the normal flow control
116 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
117 //config: case/esac. Redirections, here documents, $((arithmetic))
118 //config: and functions are supported.
120 //config: It will compile and work on no-mmu systems.
122 //config: It does not handle select, aliases, brace expansion,
123 //config: tilde expansion, &>file and >&file redirection of stdout+stderr.
125 //config:config HUSH_BASH_COMPAT
126 //config: bool "bash-compatible extensions"
128 //config: depends on HUSH
130 //config: Enable bash-compatible extensions.
132 //config:config HUSH_HELP
133 //config: bool "help builtin"
135 //config: depends on HUSH
137 //config: Enable help builtin in hush. Code size + ~1 kbyte.
139 //config:config HUSH_INTERACTIVE
140 //config: bool "Interactive mode"
142 //config: depends on HUSH
144 //config: Enable interactive mode (prompt and command editing).
145 //config: Without this, hush simply reads and executes commands
146 //config: from stdin just like a shell script from a file.
147 //config: No prompt, no PS1/PS2 magic shell variables.
149 //config:config HUSH_JOB
150 //config: bool "Job control"
152 //config: depends on HUSH_INTERACTIVE
154 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
155 //config: command (not entire shell), fg/bg builtins work. Without this option,
156 //config: "cmd &" still works by simply spawning a process and immediately
157 //config: prompting for next command (or executing next command in a script),
158 //config: but no separate process group is formed.
160 //config:config HUSH_TICK
161 //config: bool "Process substitution"
163 //config: depends on HUSH
165 //config: Enable process substitution `command` and $(command) in hush.
167 //config:config HUSH_IF
168 //config: bool "Support if/then/elif/else/fi"
170 //config: depends on HUSH
172 //config: Enable if/then/elif/else/fi in hush.
174 //config:config HUSH_LOOPS
175 //config: bool "Support for, while and until loops"
177 //config: depends on HUSH
179 //config: Enable for, while and until loops in hush.
181 //config:config HUSH_CASE
182 //config: bool "Support case ... esac statement"
184 //config: depends on HUSH
186 //config: Enable case ... esac statement in hush. +400 bytes.
188 //config:config HUSH_FUNCTIONS
189 //config: bool "Support funcname() { commands; } syntax"
191 //config: depends on HUSH
193 //config: Enable support for shell functions in hush. +800 bytes.
195 //config:config HUSH_LOCAL
196 //config: bool "Support local builtin"
198 //config: depends on HUSH_FUNCTIONS
200 //config: Enable support for local variables in functions.
202 //config:config HUSH_RANDOM_SUPPORT
203 //config: bool "Pseudorandom generator and $RANDOM variable"
205 //config: depends on HUSH
207 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
208 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
210 //config:config HUSH_EXPORT_N
211 //config: bool "Support 'export -n' option"
213 //config: depends on HUSH
215 //config: export -n unexports variables. It is a bash extension.
217 //config:config HUSH_MODE_X
218 //config: bool "Support 'hush -x' option and 'set -x' command"
220 //config: depends on HUSH
222 //config: This instructs hush to print commands before execution.
223 //config: Adds ~300 bytes.
226 //config: bool "msh (deprecated: aliased to hush)"
228 //config: select HUSH
230 //config: msh is deprecated and will be removed, please migrate to hush.
233 //usage:#define hush_trivial_usage NOUSAGE_STR
234 //usage:#define hush_full_usage ""
235 //usage:#define msh_trivial_usage NOUSAGE_STR
236 //usage:#define msh_full_usage ""
240 #define LEAK_HUNTING 0
241 #define BUILD_AS_NOMMU 0
242 /* Enable/disable sanity checks. Ok to enable in production,
243 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
244 * Keeping 1 for now even in released versions.
247 /* Slightly bigger (+200 bytes), but faster hush.
248 * So far it only enables a trick with counting SIGCHLDs and forks,
249 * which allows us to do fewer waitpid's.
250 * (we can detect a case where neither forks were done nor SIGCHLDs happened
251 * and therefore waitpid will return the same result as last time)
253 #define ENABLE_HUSH_FAST 0
254 /* TODO: implement simplified code for users which do not need ${var%...} ops
255 * So far ${var%...} ops are always enabled:
257 #define ENABLE_HUSH_DOLLAR_OPS 1
262 # undef USE_FOR_NOMMU
265 # define USE_FOR_NOMMU(...) __VA_ARGS__
266 # define USE_FOR_MMU(...)
269 #include "NUM_APPLETS.h"
271 /* STANDALONE does not make sense, and won't compile */
272 # undef CONFIG_FEATURE_SH_STANDALONE
273 # undef ENABLE_FEATURE_SH_STANDALONE
274 # undef IF_FEATURE_SH_STANDALONE
275 # undef IF_NOT_FEATURE_SH_STANDALONE
276 # define ENABLE_FEATURE_SH_STANDALONE 0
277 # define IF_FEATURE_SH_STANDALONE(...)
278 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
281 #if !ENABLE_HUSH_INTERACTIVE
282 # undef ENABLE_FEATURE_EDITING
283 # define ENABLE_FEATURE_EDITING 0
284 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
285 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
288 /* Do we support ANY keywords? */
289 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
290 # define HAS_KEYWORDS 1
291 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
292 # define IF_HAS_NO_KEYWORDS(...)
294 # define HAS_KEYWORDS 0
295 # define IF_HAS_KEYWORDS(...)
296 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
299 /* If you comment out one of these below, it will be #defined later
300 * to perform debug printfs to stderr: */
301 #define debug_printf(...) do {} while (0)
302 /* Finer-grained debug switches */
303 #define debug_printf_parse(...) do {} while (0)
304 #define debug_print_tree(a, b) do {} while (0)
305 #define debug_printf_exec(...) do {} while (0)
306 #define debug_printf_env(...) do {} while (0)
307 #define debug_printf_jobs(...) do {} while (0)
308 #define debug_printf_expand(...) do {} while (0)
309 #define debug_printf_varexp(...) do {} while (0)
310 #define debug_printf_glob(...) do {} while (0)
311 #define debug_printf_list(...) do {} while (0)
312 #define debug_printf_subst(...) do {} while (0)
313 #define debug_printf_clean(...) do {} while (0)
315 #define ERR_PTR ((void*)(long)1)
317 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
319 #define _SPECIAL_VARS_STR "_*@$!?#"
320 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
321 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
322 #if ENABLE_HUSH_BASH_COMPAT
323 /* Support / and // replace ops */
324 /* Note that // is stored as \ in "encoded" string representation */
325 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
326 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
327 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
329 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
330 # define VAR_SUBST_OPS "%#:-=+?"
331 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
334 #define SPECIAL_VAR_SYMBOL 3
338 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
340 /* This supports saving pointers malloced in vfork child,
341 * to be freed in the parent.
344 typedef struct nommu_save_t {
346 struct variable *old_vars;
348 char **argv_from_re_execing;
352 typedef enum reserved_style {
361 #if ENABLE_HUSH_LOOPS
368 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
373 /* three pseudo-keywords support contrived "case" syntax: */
374 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
375 RES_MATCH , /* "word)" */
376 RES_CASE_BODY, /* "this command is inside CASE" */
383 typedef struct o_string {
385 int length; /* position where data is appended */
387 /* Protect newly added chars against globbing
388 * (by prepending \ to *, ?, [, \) */
391 /* At least some part of the string was inside '' or "",
392 * possibly empty one: word"", wo''rd etc. */
393 smallint has_quoted_part;
394 smallint has_empty_slot;
395 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
398 MAYBE_ASSIGNMENT = 0,
399 DEFINITELY_ASSIGNMENT = 1,
401 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
403 /* Used for initialization: o_string foo = NULL_O_STRING; */
404 #define NULL_O_STRING { NULL }
406 /* I can almost use ordinary FILE*. Is open_memstream() universally
407 * available? Where is it documented? */
408 typedef struct in_str {
410 /* eof_flag=1: last char in ->p is really an EOF */
411 char eof_flag; /* meaningless if ->p == NULL */
413 #if ENABLE_HUSH_INTERACTIVE
415 smallint promptmode; /* 0: PS1, 1: PS2 */
418 int (*get) (struct in_str *) FAST_FUNC;
419 int (*peek) (struct in_str *) FAST_FUNC;
421 #define i_getch(input) ((input)->get(input))
422 #define i_peek(input) ((input)->peek(input))
424 /* The descrip member of this structure is only used to make
425 * debugging output pretty */
426 static const struct {
428 signed char default_fd;
431 { O_RDONLY, 0, "<" },
432 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
433 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
434 { O_CREAT|O_RDWR, 1, "<>" },
435 { O_RDONLY, 0, "<<" },
436 /* Should not be needed. Bogus default_fd helps in debugging */
437 /* { O_RDONLY, 77, "<<" }, */
440 struct redir_struct {
441 struct redir_struct *next;
442 char *rd_filename; /* filename */
443 int rd_fd; /* fd to redirect */
444 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
446 smallint rd_type; /* (enum redir_type) */
447 /* note: for heredocs, rd_filename contains heredoc delimiter,
448 * and subsequently heredoc itself; and rd_dup is a bitmask:
449 * bit 0: do we need to trim leading tabs?
450 * bit 1: is heredoc quoted (<<'delim' syntax) ?
453 typedef enum redir_type {
455 REDIRECT_OVERWRITE = 1,
458 REDIRECT_HEREDOC = 4,
459 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
462 REDIRFD_SYNTAX_ERR = -2,
463 REDIRFD_TO_FILE = -1,
464 /* otherwise, rd_fd is redirected to rd_dup */
466 HEREDOC_SKIPTABS = 1,
472 pid_t pid; /* 0 if exited */
473 int assignment_cnt; /* how many argv[i] are assignments? */
474 smallint is_stopped; /* is the command currently running? */
475 smallint cmd_type; /* CMD_xxx */
477 #define CMD_SUBSHELL 1
478 #if ENABLE_HUSH_BASH_COMPAT
479 /* used for "[[ EXPR ]]" */
480 # define CMD_SINGLEWORD_NOGLOB 2
482 #if ENABLE_HUSH_FUNCTIONS
483 # define CMD_FUNCDEF 3
486 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
489 char *group_as_string;
491 #if ENABLE_HUSH_FUNCTIONS
492 struct function *child_func;
493 /* This field is used to prevent a bug here:
494 * while...do f1() {a;}; f1; f1() {b;}; f1; done
495 * When we execute "f1() {a;}" cmd, we create new function and clear
496 * cmd->group, cmd->group_as_string, cmd->argv[0].
497 * When we execute "f1() {b;}", we notice that f1 exists,
498 * and that its "parent cmd" struct is still "alive",
499 * we put those fields back into cmd->xxx
500 * (struct function has ->parent_cmd ptr to facilitate that).
501 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
502 * Without this trick, loop would execute a;b;b;b;...
503 * instead of correct sequence a;b;a;b;...
504 * When command is freed, it severs the link
505 * (sets ->child_func->parent_cmd to NULL).
508 char **argv; /* command name and arguments */
509 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
510 * and on execution these are substituted with their values.
511 * Substitution can make _several_ words out of one argv[n]!
512 * Example: argv[0]=='.^C*^C.' here: echo .$*.
513 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
515 struct redir_struct *redirects; /* I/O redirections */
517 /* Is there anything in this command at all? */
518 #define IS_NULL_CMD(cmd) \
519 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
524 int num_cmds; /* total number of commands in pipe */
525 int alive_cmds; /* number of commands running (not exited) */
526 int stopped_cmds; /* number of commands alive, but stopped */
528 int jobid; /* job number */
529 pid_t pgrp; /* process group ID for the job */
530 char *cmdtext; /* name of job */
532 struct command *cmds; /* array of commands in pipe */
533 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
534 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
535 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
537 typedef enum pipe_style {
543 /* Is there anything in this pipe at all? */
544 #define IS_NULL_PIPE(pi) \
545 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
547 /* This holds pointers to the various results of parsing */
548 struct parse_context {
549 /* linked list of pipes */
550 struct pipe *list_head;
551 /* last pipe (being constructed right now) */
553 /* last command in pipe (being constructed right now) */
554 struct command *command;
555 /* last redirect in command->redirects list */
556 struct redir_struct *pending_redirect;
562 smallint ctx_inverted; /* "! cmd | cmd" */
564 smallint ctx_dsemicolon; /* ";;" seen */
566 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
568 /* group we are enclosed in:
569 * example: "if pipe1; pipe2; then pipe3; fi"
570 * when we see "if" or "then", we malloc and copy current context,
571 * and make ->stack point to it. then we parse pipeN.
572 * when closing "then" / fi" / whatever is found,
573 * we move list_head into ->stack->command->group,
574 * copy ->stack into current context, and delete ->stack.
575 * (parsing of { list } and ( list ) doesn't use this method)
577 struct parse_context *stack;
581 /* On program start, environ points to initial environment.
582 * putenv adds new pointers into it, unsetenv removes them.
583 * Neither of these (de)allocates the strings.
584 * setenv allocates new strings in malloc space and does putenv,
585 * and thus setenv is unusable (leaky) for shell's purposes */
586 #define setenv(...) setenv_is_leaky_dont_use()
588 struct variable *next;
589 char *varstr; /* points to "name=" portion */
590 #if ENABLE_HUSH_LOCAL
591 unsigned func_nest_level;
593 int max_len; /* if > 0, name is part of initial env; else name is malloced */
594 smallint flg_export; /* putenv should be done on this var */
595 smallint flg_read_only;
603 #if ENABLE_HUSH_FUNCTIONS
605 struct function *next;
607 struct command *parent_cmd;
610 char *body_as_string;
616 /* "Globals" within this file */
617 /* Sorted roughly by size (smaller offsets == smaller code) */
619 /* interactive_fd != 0 means we are an interactive shell.
620 * If we are, then saved_tty_pgrp can also be != 0, meaning
621 * that controlling tty is available. With saved_tty_pgrp == 0,
622 * job control still works, but terminal signals
623 * (^C, ^Z, ^Y, ^\) won't work at all, and background
624 * process groups can only be created with "cmd &".
625 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
626 * to give tty to the foreground process group,
627 * and will take it back when the group is stopped (^Z)
630 #if ENABLE_HUSH_INTERACTIVE
631 /* 'interactive_fd' is a fd# open to ctty, if we have one
632 * _AND_ if we decided to act interactively */
636 # define G_interactive_fd (G.interactive_fd)
638 # define G_interactive_fd 0
640 #if ENABLE_FEATURE_EDITING
641 line_input_t *line_input_state;
646 #if ENABLE_HUSH_RANDOM_SUPPORT
652 pid_t saved_tty_pgrp;
653 struct pipe *job_list;
654 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
656 # define G_saved_tty_pgrp 0
658 smallint flag_SIGINT;
659 #if ENABLE_HUSH_LOOPS
660 smallint flag_break_continue;
662 #if ENABLE_HUSH_FUNCTIONS
663 /* 0: outside of a function (or sourced file)
664 * -1: inside of a function, ok to use return builtin
665 * 1: return is invoked, skip all till end of func
667 smallint flag_return_in_progress;
670 #if ENABLE_HUSH_MODE_X
672 # define G_x_mode (G.x_mode)
676 smallint exiting; /* used to prevent EXIT trap recursion */
677 /* These four support $?, $#, and $1 */
678 smalluint last_exitcode;
679 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
680 smalluint global_args_malloced;
681 smalluint inherited_set_is_saved;
682 /* how many non-NULL argv's we have. NB: $# + 1 */
686 char *argv0_for_re_execing;
688 #if ENABLE_HUSH_LOOPS
689 unsigned depth_break_continue;
690 unsigned depth_of_loop;
694 struct variable *top_var; /* = &G.shell_ver (set in main()) */
695 struct variable shell_ver;
696 char **expanded_assignments;
697 #if ENABLE_HUSH_FUNCTIONS
698 struct function *top_func;
699 # if ENABLE_HUSH_LOCAL
700 struct variable **shadowed_vars_pp;
701 unsigned func_nest_level;
704 /* Signal and trap handling */
706 unsigned count_SIGCHLD;
707 unsigned handled_SIGCHLD;
708 smallint we_have_children;
710 /* which signals have non-DFL handler (even with no traps set)? */
711 unsigned non_DFL_mask;
712 char **traps; /* char *traps[NSIG] */
713 sigset_t blocked_set;
714 sigset_t inherited_set;
716 unsigned long memleak_value;
719 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
721 #define G (*ptr_to_globals)
722 /* Not #defining name to G.name - this quickly gets unwieldy
723 * (too many defines). Also, I actually prefer to see when a variable
724 * is global, thus "G." prefix is a useful hint */
725 #define INIT_G() do { \
726 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
730 /* Function prototypes for builtins */
731 static int builtin_cd(char **argv) FAST_FUNC;
732 static int builtin_echo(char **argv) FAST_FUNC;
733 static int builtin_eval(char **argv) FAST_FUNC;
734 static int builtin_exec(char **argv) FAST_FUNC;
735 static int builtin_exit(char **argv) FAST_FUNC;
736 static int builtin_export(char **argv) FAST_FUNC;
738 static int builtin_fg_bg(char **argv) FAST_FUNC;
739 static int builtin_jobs(char **argv) FAST_FUNC;
742 static int builtin_help(char **argv) FAST_FUNC;
744 #if ENABLE_HUSH_LOCAL
745 static int builtin_local(char **argv) FAST_FUNC;
748 static int builtin_memleak(char **argv) FAST_FUNC;
751 static int builtin_printf(char **argv) FAST_FUNC;
753 static int builtin_pwd(char **argv) FAST_FUNC;
754 static int builtin_read(char **argv) FAST_FUNC;
755 static int builtin_set(char **argv) FAST_FUNC;
756 static int builtin_shift(char **argv) FAST_FUNC;
757 static int builtin_source(char **argv) FAST_FUNC;
758 static int builtin_test(char **argv) FAST_FUNC;
759 static int builtin_trap(char **argv) FAST_FUNC;
760 static int builtin_type(char **argv) FAST_FUNC;
761 static int builtin_true(char **argv) FAST_FUNC;
762 static int builtin_umask(char **argv) FAST_FUNC;
763 static int builtin_unset(char **argv) FAST_FUNC;
764 static int builtin_wait(char **argv) FAST_FUNC;
765 #if ENABLE_HUSH_LOOPS
766 static int builtin_break(char **argv) FAST_FUNC;
767 static int builtin_continue(char **argv) FAST_FUNC;
769 #if ENABLE_HUSH_FUNCTIONS
770 static int builtin_return(char **argv) FAST_FUNC;
773 /* Table of built-in functions. They can be forked or not, depending on
774 * context: within pipes, they fork. As simple commands, they do not.
775 * When used in non-forking context, they can change global variables
776 * in the parent shell process. If forked, of course they cannot.
777 * For example, 'unset foo | whatever' will parse and run, but foo will
778 * still be set at the end. */
779 struct built_in_command {
781 int (*b_function)(char **argv) FAST_FUNC;
784 # define BLTIN(cmd, func, help) { cmd, func, help }
786 # define BLTIN(cmd, func, help) { cmd, func }
790 static const struct built_in_command bltins1[] = {
791 BLTIN("." , builtin_source , "Run commands in a file"),
792 BLTIN(":" , builtin_true , NULL),
794 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
796 #if ENABLE_HUSH_LOOPS
797 BLTIN("break" , builtin_break , "Exit from a loop"),
799 BLTIN("cd" , builtin_cd , "Change directory"),
800 #if ENABLE_HUSH_LOOPS
801 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
803 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
804 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
805 BLTIN("exit" , builtin_exit , "Exit"),
806 BLTIN("export" , builtin_export , "Set environment variables"),
808 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
811 BLTIN("help" , builtin_help , NULL),
814 BLTIN("jobs" , builtin_jobs , "List jobs"),
816 #if ENABLE_HUSH_LOCAL
817 BLTIN("local" , builtin_local , "Set local variables"),
820 BLTIN("memleak" , builtin_memleak , NULL),
822 BLTIN("read" , builtin_read , "Input into variable"),
823 #if ENABLE_HUSH_FUNCTIONS
824 BLTIN("return" , builtin_return , "Return from a function"),
826 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
827 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
828 #if ENABLE_HUSH_BASH_COMPAT
829 BLTIN("source" , builtin_source , "Run commands in a file"),
831 BLTIN("trap" , builtin_trap , "Trap signals"),
832 BLTIN("type" , builtin_type , "Show command type"),
833 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
834 BLTIN("umask" , builtin_umask , "Set file creation mask"),
835 BLTIN("unset" , builtin_unset , "Unset variables"),
836 BLTIN("wait" , builtin_wait , "Wait for process"),
838 /* For now, echo and test are unconditionally enabled.
839 * Maybe make it configurable? */
840 static const struct built_in_command bltins2[] = {
841 BLTIN("[" , builtin_test , NULL),
842 BLTIN("echo" , builtin_echo , NULL),
844 BLTIN("printf" , builtin_printf , NULL),
846 BLTIN("pwd" , builtin_pwd , NULL),
847 BLTIN("test" , builtin_test , NULL),
854 /* prevent disasters with G.debug_indent < 0 */
855 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
856 # define debug_enter() (G.debug_indent++)
857 # define debug_leave() (G.debug_indent--)
859 # define indent() ((void)0)
860 # define debug_enter() ((void)0)
861 # define debug_leave() ((void)0)
865 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
868 #ifndef debug_printf_parse
869 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
872 #ifndef debug_printf_exec
873 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
876 #ifndef debug_printf_env
877 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
880 #ifndef debug_printf_jobs
881 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
882 # define DEBUG_JOBS 1
884 # define DEBUG_JOBS 0
887 #ifndef debug_printf_expand
888 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
889 # define DEBUG_EXPAND 1
891 # define DEBUG_EXPAND 0
894 #ifndef debug_printf_varexp
895 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
898 #ifndef debug_printf_glob
899 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
900 # define DEBUG_GLOB 1
902 # define DEBUG_GLOB 0
905 #ifndef debug_printf_list
906 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
909 #ifndef debug_printf_subst
910 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
913 #ifndef debug_printf_clean
914 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
915 # define DEBUG_CLEAN 1
917 # define DEBUG_CLEAN 0
921 static void debug_print_strings(const char *prefix, char **vv)
924 fprintf(stderr, "%s:\n", prefix);
926 fprintf(stderr, " '%s'\n", *vv++);
929 # define debug_print_strings(prefix, vv) ((void)0)
933 /* Leak hunting. Use hush_leaktool.sh for post-processing.
936 static void *xxmalloc(int lineno, size_t size)
938 void *ptr = xmalloc((size + 0xff) & ~0xff);
939 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
942 static void *xxrealloc(int lineno, void *ptr, size_t size)
944 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
945 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
948 static char *xxstrdup(int lineno, const char *str)
950 char *ptr = xstrdup(str);
951 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
954 static void xxfree(void *ptr)
956 fdprintf(2, "free %p\n", ptr);
959 # define xmalloc(s) xxmalloc(__LINE__, s)
960 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
961 # define xstrdup(s) xxstrdup(__LINE__, s)
962 # define free(p) xxfree(p)
966 /* Syntax and runtime errors. They always abort scripts.
967 * In interactive use they usually discard unparsed and/or unexecuted commands
968 * and return to the prompt.
969 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
972 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
973 # define syntax_error(lineno, msg) syntax_error(msg)
974 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
975 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
976 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
977 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
980 static void die_if_script(unsigned lineno, const char *fmt, ...)
985 bb_error_msg("hush.c:%u", lineno);
988 bb_verror_msg(fmt, p, NULL);
990 if (!G_interactive_fd)
994 static void syntax_error(unsigned lineno, const char *msg)
997 die_if_script(lineno, "syntax error: %s", msg);
999 die_if_script(lineno, "syntax error", NULL);
1002 static void syntax_error_at(unsigned lineno, const char *msg)
1004 die_if_script(lineno, "syntax error at '%s'", msg);
1007 static void syntax_error_unterm_str(unsigned lineno, const char *s)
1009 die_if_script(lineno, "syntax error: unterminated %s", s);
1012 /* It so happens that all such cases are totally fatal
1013 * even if shell is interactive: EOF while looking for closing
1014 * delimiter. There is nowhere to read stuff from after that,
1015 * it's EOF! The only choice is to terminate.
1017 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
1018 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1020 char msg[2] = { ch, '\0' };
1021 syntax_error_unterm_str(lineno, msg);
1025 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
1030 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1034 # undef die_if_script
1035 # undef syntax_error
1036 # undef syntax_error_at
1037 # undef syntax_error_unterm_ch
1038 # undef syntax_error_unterm_str
1039 # undef syntax_error_unexpected_ch
1041 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1042 # define syntax_error(msg) syntax_error(__LINE__, msg)
1043 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1044 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1045 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1046 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1050 #if ENABLE_HUSH_INTERACTIVE
1051 static void cmdedit_update_prompt(void);
1053 # define cmdedit_update_prompt() ((void)0)
1057 /* Utility functions
1059 /* Replace each \x with x in place, return ptr past NUL. */
1060 static char *unbackslash(char *src)
1062 char *dst = src = strchrnul(src, '\\');
1066 if ((*dst++ = *src++) == '\0')
1072 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1093 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1094 v[count1 + count2] = NULL;
1097 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1101 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1103 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1104 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1107 #define add_strings_to_strings(strings, add, need_to_dup) \
1108 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1111 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1112 static char **add_string_to_strings(char **strings, char *add)
1117 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1120 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1122 char **ptr = add_string_to_strings(strings, add);
1123 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1126 #define add_string_to_strings(strings, add) \
1127 xx_add_string_to_strings(__LINE__, strings, add)
1130 static void free_strings(char **strings)
1145 /* Helpers for setting new $n and restoring them back
1147 typedef struct save_arg_t {
1151 smallint sv_g_malloced;
1154 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1158 sv->sv_argv0 = argv[0];
1159 sv->sv_g_argv = G.global_argv;
1160 sv->sv_g_argc = G.global_argc;
1161 sv->sv_g_malloced = G.global_args_malloced;
1163 argv[0] = G.global_argv[0]; /* retain $0 */
1164 G.global_argv = argv;
1165 G.global_args_malloced = 0;
1173 static void restore_G_args(save_arg_t *sv, char **argv)
1177 if (G.global_args_malloced) {
1178 /* someone ran "set -- arg1 arg2 ...", undo */
1180 while (*++pp) /* note: does not free $0 */
1182 free(G.global_argv);
1184 argv[0] = sv->sv_argv0;
1185 G.global_argv = sv->sv_g_argv;
1186 G.global_argc = sv->sv_g_argc;
1187 G.global_args_malloced = sv->sv_g_malloced;
1191 /* Basic theory of signal handling in shell
1192 * ========================================
1193 * This does not describe what hush does, rather, it is current understanding
1194 * what it _should_ do. If it doesn't, it's a bug.
1195 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1197 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1198 * is finished or backgrounded. It is the same in interactive and
1199 * non-interactive shells, and is the same regardless of whether
1200 * a user trap handler is installed or a shell special one is in effect.
1201 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1202 * backgrounds (i.e. stops) or kills all members of currently running
1205 * Wait builtin in interruptible by signals for which user trap is set
1206 * or by SIGINT in interactive shell.
1208 * Trap handlers will execute even within trap handlers. (right?)
1210 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1211 * except for handlers set to '' (empty string).
1213 * If job control is off, backgrounded commands ("cmd &")
1214 * have SIGINT, SIGQUIT set to SIG_IGN.
1216 * Commands which are run in command substitution ("`cmd`")
1217 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1219 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1220 * by the shell from its parent.
1222 * Signals which differ from SIG_DFL action
1223 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1226 * SIGTERM (interactive): ignore
1227 * SIGHUP (interactive):
1228 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1229 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1230 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1231 * that all pipe members are stopped. Try this in bash:
1232 * while :; do :; done - ^Z does not background it
1233 * (while :; do :; done) - ^Z backgrounds it
1234 * SIGINT (interactive): wait for last pipe, ignore the rest
1235 * of the command line, show prompt. NB: ^C does not send SIGINT
1236 * to interactive shell while shell is waiting for a pipe,
1237 * since shell is bg'ed (is not in foreground process group).
1238 * Example 1: this waits 5 sec, but does not execute ls:
1239 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1240 * Example 2: this does not wait and does not execute ls:
1241 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1242 * Example 3: this does not wait 5 sec, but executes ls:
1243 * "sleep 5; ls -l" + press ^C
1245 * (What happens to signals which are IGN on shell start?)
1246 * (What happens with signal mask on shell start?)
1248 * Implementation in hush
1249 * ======================
1250 * We use in-kernel pending signal mask to determine which signals were sent.
1251 * We block all signals which we don't want to take action immediately,
1252 * i.e. we block all signals which need to have special handling as described
1253 * above, and all signals which have traps set.
1254 * After each pipe execution, we extract any pending signals via sigtimedwait()
1257 * unsigned non_DFL_mask: a mask of such "special" signals
1258 * sigset_t blocked_set: current blocked signal set
1261 * clear bit in blocked_set unless it is also in non_DFL_mask
1262 * "trap 'cmd' SIGxxx":
1263 * set bit in blocked_set (even if 'cmd' is '')
1264 * after [v]fork, if we plan to be a shell:
1265 * unblock signals with special interactive handling
1266 * (child shell is not interactive),
1267 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1268 * after [v]fork, if we plan to exec:
1269 * POSIX says fork clears pending signal mask in child - no need to clear it.
1270 * Restore blocked signal set to one inherited by shell just prior to exec.
1272 * Note: as a result, we do not use signal handlers much. The only uses
1273 * are to count SIGCHLDs
1274 * and to restore tty pgrp on signal-induced exit.
1277 * Standard says "When a subshell is entered, traps that are not being ignored
1278 * are set to the default actions". bash interprets it so that traps which
1279 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1282 SPECIAL_INTERACTIVE_SIGS = 0
1287 SPECIAL_JOB_SIGS = 0
1295 #if ENABLE_HUSH_FAST
1296 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1299 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1305 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1306 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1307 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1308 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1310 /* Restores tty foreground process group, and exits.
1311 * May be called as signal handler for fatal signal
1312 * (will resend signal to itself, producing correct exit state)
1313 * or called directly with -EXITCODE.
1314 * We also call it if xfunc is exiting. */
1315 static void sigexit(int sig) NORETURN;
1316 static void sigexit(int sig)
1318 /* Disable all signals: job control, SIGPIPE, etc. */
1319 sigprocmask_allsigs(SIG_BLOCK);
1321 /* Careful: we can end up here after [v]fork. Do not restore
1322 * tty pgrp then, only top-level shell process does that */
1323 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1324 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1326 /* Not a signal, just exit */
1330 kill_myself_with_sig(sig); /* does not return */
1334 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1335 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1339 /* Restores tty foreground process group, and exits. */
1340 static void hush_exit(int exitcode) NORETURN;
1341 static void hush_exit(int exitcode)
1343 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1344 /* Prevent recursion:
1345 * trap "echo Hi; exit" EXIT; exit
1348 /* argv[0] is unused */
1349 argv[1] = G.traps[0];
1354 /* free(argv[1]); - why bother */
1359 sigexit(- (exitcode & 0xff));
1365 static int check_and_run_traps(int sig)
1367 static const struct timespec zero_timespec;
1368 smalluint save_rcode;
1374 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1379 if (G.traps && G.traps[sig]) {
1380 if (G.traps[sig][0]) {
1381 /* We have user-defined handler */
1383 /* argv[0] is unused */
1384 argv[1] = G.traps[sig];
1386 save_rcode = G.last_exitcode;
1388 G.last_exitcode = save_rcode;
1389 } /* else: "" trap, ignoring signal */
1392 /* not a trap: special action */
1394 #if ENABLE_HUSH_FAST
1397 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1401 /* Builtin was ^C'ed, make it look prettier: */
1408 /* bash is observed to signal whole process groups,
1409 * not individual processes */
1410 for (job = G.job_list; job; job = job->next) {
1413 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1414 if (kill(- job->pgrp, SIGHUP) == 0)
1415 kill(- job->pgrp, SIGCONT);
1420 default: /* ignored: */
1421 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1429 static const char *get_cwd(int force)
1431 if (force || G.cwd == NULL) {
1432 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1433 * we must not try to free(bb_msg_unknown) */
1434 if (G.cwd == bb_msg_unknown)
1436 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1438 G.cwd = bb_msg_unknown;
1445 * Shell and environment variable support
1447 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1449 struct variable **pp;
1450 struct variable *cur;
1453 while ((cur = *pp) != NULL) {
1454 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1461 static const char* FAST_FUNC get_local_var_value(const char *name)
1463 struct variable **vpp;
1464 unsigned len = strlen(name);
1466 if (G.expanded_assignments) {
1467 char **cpp = G.expanded_assignments;
1470 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1471 return cp + len + 1;
1476 vpp = get_ptr_to_local_var(name, len);
1478 return (*vpp)->varstr + len + 1;
1480 if (strcmp(name, "PPID") == 0)
1481 return utoa(G.root_ppid);
1482 // bash compat: UID? EUID?
1483 #if ENABLE_HUSH_RANDOM_SUPPORT
1484 if (strcmp(name, "RANDOM") == 0)
1485 return utoa(next_random(&G.random_gen));
1490 /* str holds "NAME=VAL" and is expected to be malloced.
1491 * We take ownership of it.
1493 * 0: do not change export flag
1494 * (if creating new variable, flag will be 0)
1495 * 1: set export flag and putenv the variable
1496 * -1: clear export flag and unsetenv the variable
1497 * flg_read_only is set only when we handle -R var=val
1499 #if !BB_MMU && ENABLE_HUSH_LOCAL
1500 /* all params are used */
1501 #elif BB_MMU && ENABLE_HUSH_LOCAL
1502 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1503 set_local_var(str, flg_export, local_lvl)
1504 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1505 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1506 set_local_var(str, flg_export)
1507 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1508 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1509 set_local_var(str, flg_export, flg_read_only)
1511 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1513 struct variable **var_pp;
1514 struct variable *cur;
1518 eq_sign = strchr(str, '=');
1519 if (!eq_sign) { /* not expected to ever happen? */
1524 name_len = eq_sign - str + 1; /* including '=' */
1525 var_pp = &G.top_var;
1526 while ((cur = *var_pp) != NULL) {
1527 if (strncmp(cur->varstr, str, name_len) != 0) {
1528 var_pp = &cur->next;
1531 /* We found an existing var with this name */
1532 if (cur->flg_read_only) {
1536 bb_error_msg("%s: readonly variable", str);
1540 if (flg_export == -1) { // "&& cur->flg_export" ?
1541 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1546 #if ENABLE_HUSH_LOCAL
1547 if (cur->func_nest_level < local_lvl) {
1548 /* New variable is declared as local,
1549 * and existing one is global, or local
1550 * from enclosing function.
1551 * Remove and save old one: */
1552 *var_pp = cur->next;
1553 cur->next = *G.shadowed_vars_pp;
1554 *G.shadowed_vars_pp = cur;
1555 /* bash 3.2.33(1) and exported vars:
1557 * # f() { local z=a; env | grep ^z; }
1563 if (cur->flg_export)
1568 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1573 if (cur->max_len != 0) {
1574 if (cur->max_len >= strlen(str)) {
1575 /* This one is from startup env, reuse space */
1576 strcpy(cur->varstr, str);
1580 /* max_len == 0 signifies "malloced" var, which we can
1581 * (and has to) free */
1585 goto set_str_and_exp;
1588 /* Not found - create new variable struct */
1589 cur = xzalloc(sizeof(*cur));
1590 #if ENABLE_HUSH_LOCAL
1591 cur->func_nest_level = local_lvl;
1593 cur->next = *var_pp;
1599 cur->flg_read_only = flg_read_only;
1602 if (flg_export == 1)
1603 cur->flg_export = 1;
1604 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1605 cmdedit_update_prompt();
1606 if (cur->flg_export) {
1607 if (flg_export == -1) {
1608 cur->flg_export = 0;
1609 /* unsetenv was already done */
1611 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1612 return putenv(cur->varstr);
1618 /* Used at startup and after each cd */
1619 static void set_pwd_var(int exp)
1621 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1622 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1625 static int unset_local_var_len(const char *name, int name_len)
1627 struct variable *cur;
1628 struct variable **var_pp;
1631 return EXIT_SUCCESS;
1632 var_pp = &G.top_var;
1633 while ((cur = *var_pp) != NULL) {
1634 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1635 if (cur->flg_read_only) {
1636 bb_error_msg("%s: readonly variable", name);
1637 return EXIT_FAILURE;
1639 *var_pp = cur->next;
1640 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1641 bb_unsetenv(cur->varstr);
1642 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1643 cmdedit_update_prompt();
1647 return EXIT_SUCCESS;
1649 var_pp = &cur->next;
1651 return EXIT_SUCCESS;
1654 static int unset_local_var(const char *name)
1656 return unset_local_var_len(name, strlen(name));
1659 static void unset_vars(char **strings)
1667 const char *eq = strchrnul(*v, '=');
1668 unset_local_var_len(*v, (int)(eq - *v));
1674 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1676 char *var = xasprintf("%s=%s", name, val);
1677 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1682 * Helpers for "var1=val1 var2=val2 cmd" feature
1684 static void add_vars(struct variable *var)
1686 struct variable *next;
1690 var->next = G.top_var;
1692 if (var->flg_export) {
1693 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1694 putenv(var->varstr);
1696 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1702 static struct variable *set_vars_and_save_old(char **strings)
1705 struct variable *old = NULL;
1711 struct variable *var_p;
1712 struct variable **var_pp;
1715 eq = strchr(*s, '=');
1717 var_pp = get_ptr_to_local_var(*s, eq - *s);
1719 /* Remove variable from global linked list */
1721 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1722 *var_pp = var_p->next;
1723 /* Add it to returned list */
1727 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1738 static int FAST_FUNC static_get(struct in_str *i)
1748 static int FAST_FUNC static_peek(struct in_str *i)
1753 #if ENABLE_HUSH_INTERACTIVE
1755 static void cmdedit_update_prompt(void)
1757 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1758 G.PS1 = get_local_var_value("PS1");
1761 G.PS2 = get_local_var_value("PS2");
1769 static const char *setup_prompt_string(int promptmode)
1771 const char *prompt_str;
1772 debug_printf("setup_prompt_string %d ", promptmode);
1773 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1774 /* Set up the prompt */
1775 if (promptmode == 0) { /* PS1 */
1777 /* bash uses $PWD value, even if it is set by user.
1778 * It uses current dir only if PWD is unset.
1779 * We always use current dir. */
1780 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1785 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1786 debug_printf("result '%s'\n", prompt_str);
1790 static void get_user_input(struct in_str *i)
1793 const char *prompt_str;
1795 prompt_str = setup_prompt_string(i->promptmode);
1796 # if ENABLE_FEATURE_EDITING
1797 /* Enable command line editing only while a command line
1798 * is actually being read */
1801 /* buglet: SIGINT will not make new prompt to appear _at once_,
1802 * only after <Enter>. (^C will work) */
1803 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1804 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1805 check_and_run_traps(0);
1806 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1807 i->eof_flag = (r < 0);
1808 if (i->eof_flag) { /* EOF/error detected */
1809 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1810 G.user_input_buf[1] = '\0';
1815 fputs(prompt_str, stdout);
1817 G.user_input_buf[0] = r = fgetc(i->file);
1818 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1819 //do we need check_and_run_traps(0)? (maybe only if stdin)
1820 } while (G.flag_SIGINT);
1821 i->eof_flag = (r == EOF);
1823 i->p = G.user_input_buf;
1826 #endif /* INTERACTIVE */
1828 /* This is the magic location that prints prompts
1829 * and gets data back from the user */
1830 static int FAST_FUNC file_get(struct in_str *i)
1834 /* If there is data waiting, eat it up */
1835 if (i->p && *i->p) {
1836 #if ENABLE_HUSH_INTERACTIVE
1840 if (i->eof_flag && !*i->p)
1842 /* note: ch is never NUL */
1844 /* need to double check i->file because we might be doing something
1845 * more complicated by now, like sourcing or substituting. */
1846 #if ENABLE_HUSH_INTERACTIVE
1847 if (G_interactive_fd && i->promptme && i->file == stdin) {
1850 } while (!*i->p); /* need non-empty line */
1851 i->promptmode = 1; /* PS2 */
1856 do ch = fgetc(i->file); while (ch == '\0');
1858 debug_printf("file_get: got '%c' %d\n", ch, ch);
1859 #if ENABLE_HUSH_INTERACTIVE
1866 /* All callers guarantee this routine will never
1867 * be used right after a newline, so prompting is not needed.
1869 static int FAST_FUNC file_peek(struct in_str *i)
1872 if (i->p && *i->p) {
1873 if (i->eof_flag && !i->p[1])
1876 /* note: ch is never NUL */
1878 do ch = fgetc(i->file); while (ch == '\0');
1879 i->eof_flag = (ch == EOF);
1880 i->peek_buf[0] = ch;
1881 i->peek_buf[1] = '\0';
1883 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1887 static void setup_file_in_str(struct in_str *i, FILE *f)
1889 i->peek = file_peek;
1891 #if ENABLE_HUSH_INTERACTIVE
1893 i->promptmode = 0; /* PS1 */
1899 static void setup_string_in_str(struct in_str *i, const char *s)
1901 i->peek = static_peek;
1902 i->get = static_get;
1903 #if ENABLE_HUSH_INTERACTIVE
1905 i->promptmode = 0; /* PS1 */
1915 #define B_CHUNK (32 * sizeof(char*))
1917 static void o_reset_to_empty_unquoted(o_string *o)
1920 o->has_quoted_part = 0;
1925 static void o_free(o_string *o)
1928 memset(o, 0, sizeof(*o));
1931 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1936 static void o_grow_by(o_string *o, int len)
1938 if (o->length + len > o->maxlen) {
1939 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1940 o->data = xrealloc(o->data, 1 + o->maxlen);
1944 static void o_addchr(o_string *o, int ch)
1946 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1948 o->data[o->length] = ch;
1950 o->data[o->length] = '\0';
1953 static void o_addblock(o_string *o, const char *str, int len)
1956 memcpy(&o->data[o->length], str, len);
1958 o->data[o->length] = '\0';
1961 static void o_addstr(o_string *o, const char *str)
1963 o_addblock(o, str, strlen(str));
1967 static void nommu_addchr(o_string *o, int ch)
1973 # define nommu_addchr(o, str) ((void)0)
1976 static void o_addstr_with_NUL(o_string *o, const char *str)
1978 o_addblock(o, str, strlen(str) + 1);
1981 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1986 if (*str++ == '\\') {
1987 /* \z -> \\\z; \<eol> -> \\<eol> */
1992 o_addchr(o, *str++);
1998 #undef HUSH_BRACE_EXP
2000 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
2001 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2002 * Apparently, on unquoted $v bash still does globbing
2003 * ("v='*.txt'; echo $v" prints all .txt files),
2004 * but NOT brace expansion! Thus, there should be TWO independent
2005 * quoting mechanisms on $v expansion side: one protects
2006 * $v from brace expansion, and other additionally protects "$v" against globbing.
2007 * We have only second one.
2010 #ifdef HUSH_BRACE_EXP
2011 # define MAYBE_BRACES "{}"
2013 # define MAYBE_BRACES ""
2016 /* My analysis of quoting semantics tells me that state information
2017 * is associated with a destination, not a source.
2019 static void o_addqchr(o_string *o, int ch)
2022 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2027 o->data[o->length] = '\\';
2030 o->data[o->length] = ch;
2032 o->data[o->length] = '\0';
2035 static void o_addQchr(o_string *o, int ch)
2038 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
2040 o->data[o->length] = '\\';
2044 o->data[o->length] = ch;
2046 o->data[o->length] = '\0';
2049 static void o_addqblock(o_string *o, const char *str, int len)
2054 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2055 if (ordinary_cnt > len) /* paranoia */
2057 o_addblock(o, str, ordinary_cnt);
2058 if (ordinary_cnt == len)
2060 str += ordinary_cnt;
2061 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2065 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2067 o->data[o->length] = '\\';
2071 o->data[o->length] = ch;
2073 o->data[o->length] = '\0';
2077 static void o_addQblock(o_string *o, const char *str, int len)
2080 o_addblock(o, str, len);
2083 o_addqblock(o, str, len);
2086 static void o_addQstr(o_string *o, const char *str)
2088 o_addQblock(o, str, strlen(str));
2091 /* A special kind of o_string for $VAR and `cmd` expansion.
2092 * It contains char* list[] at the beginning, which is grown in 16 element
2093 * increments. Actual string data starts at the next multiple of 16 * (char*).
2094 * list[i] contains an INDEX (int!) into this string data.
2095 * It means that if list[] needs to grow, data needs to be moved higher up
2096 * but list[i]'s need not be modified.
2097 * NB: remembering how many list[i]'s you have there is crucial.
2098 * o_finalize_list() operation post-processes this structure - calculates
2099 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2101 #if DEBUG_EXPAND || DEBUG_GLOB
2102 static void debug_print_list(const char *prefix, o_string *o, int n)
2104 char **list = (char**)o->data;
2105 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2109 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2110 prefix, list, n, string_start, o->length, o->maxlen, o->o_glob, o->has_quoted_part, o->o_escape);
2113 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
2114 o->data + (int)list[i] + string_start,
2115 o->data + (int)list[i] + string_start);
2119 const char *p = o->data + (int)list[n - 1] + string_start;
2121 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2125 # define debug_print_list(prefix, o, n) ((void)0)
2128 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2129 * in list[n] so that it points past last stored byte so far.
2130 * It returns n+1. */
2131 static int o_save_ptr_helper(o_string *o, int n)
2133 char **list = (char**)o->data;
2137 if (!o->has_empty_slot) {
2138 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2139 string_len = o->length - string_start;
2140 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2141 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2142 /* list[n] points to string_start, make space for 16 more pointers */
2143 o->maxlen += 0x10 * sizeof(list[0]);
2144 o->data = xrealloc(o->data, o->maxlen + 1);
2145 list = (char**)o->data;
2146 memmove(list + n + 0x10, list + n, string_len);
2147 o->length += 0x10 * sizeof(list[0]);
2149 debug_printf_list("list[%d]=%d string_start=%d\n",
2150 n, string_len, string_start);
2153 /* We have empty slot at list[n], reuse without growth */
2154 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2155 string_len = o->length - string_start;
2156 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2157 n, string_len, string_start);
2158 o->has_empty_slot = 0;
2160 list[n] = (char*)(uintptr_t)string_len;
2164 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2165 static int o_get_last_ptr(o_string *o, int n)
2167 char **list = (char**)o->data;
2168 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2170 return ((int)(uintptr_t)list[n-1]) + string_start;
2173 #ifdef HUSH_BRACE_EXP
2174 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2175 * first, it processes even {a} (no commas), second,
2176 * I didn't manage to make it return strings when they don't match
2177 * existing files. Need to re-implement it.
2181 static int glob_needed(const char *s)
2190 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2196 /* Return pointer to next closing brace or to comma */
2197 static const char *next_brace_sub(const char *cp)
2201 while (*cp != '\0') {
2208 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2214 return *cp != '\0' ? cp : NULL;
2216 /* Recursive brace globber. Note: may garble pattern[]. */
2217 static int glob_brace(char *pattern, o_string *o, int n)
2219 char *new_pattern_buf;
2226 debug_printf_glob("glob_brace('%s')\n", pattern);
2232 if (*begin == '{') {
2233 /* Find the first sub-pattern and at the same time
2234 * find the rest after the closing brace */
2235 next = next_brace_sub(begin);
2237 /* An illegal expression */
2241 /* "{abc}" with no commas - illegal
2242 * brace expr, disregard and skip it */
2248 if (*begin == '\\' && begin[1] != '\0')
2252 debug_printf_glob("begin:%s\n", begin);
2253 debug_printf_glob("next:%s\n", next);
2255 /* Now find the end of the whole brace expression */
2257 while (*rest != '}') {
2258 rest = next_brace_sub(rest);
2260 /* An illegal expression */
2263 debug_printf_glob("rest:%s\n", rest);
2265 rest_len = strlen(++rest) + 1;
2267 /* We are sure the brace expression is well-formed */
2269 /* Allocate working buffer large enough for our work */
2270 new_pattern_buf = xmalloc(strlen(pattern));
2272 /* We have a brace expression. BEGIN points to the opening {,
2273 * NEXT points past the terminator of the first element, and REST
2274 * points past the final }. We will accumulate result names from
2275 * recursive runs for each brace alternative in the buffer using
2280 /* Construct the new glob expression */
2283 mempcpy(new_pattern_buf,
2284 /* We know the prefix for all sub-patterns */
2285 pattern, begin - pattern),
2289 /* Note: glob_brace() may garble new_pattern_buf[].
2290 * That's why we re-copy prefix every time (1st memcpy above).
2292 n = glob_brace(new_pattern_buf, o, n);
2294 /* We saw the last entry */
2298 next = next_brace_sub(next);
2300 free(new_pattern_buf);
2308 memset(&globdata, 0, sizeof(globdata));
2309 gr = glob(pattern, 0, NULL, &globdata);
2310 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2312 if (gr == GLOB_NOMATCH) {
2313 globfree(&globdata);
2314 /* NB: garbles parameter */
2315 unbackslash(pattern);
2316 o_addstr_with_NUL(o, pattern);
2317 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2318 return o_save_ptr_helper(o, n);
2320 if (gr == GLOB_NOSPACE)
2321 bb_error_msg_and_die(bb_msg_memory_exhausted);
2322 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2323 * but we didn't specify it. Paranoia again. */
2324 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2326 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2327 char **argv = globdata.gl_pathv;
2329 o_addstr_with_NUL(o, *argv);
2330 n = o_save_ptr_helper(o, n);
2336 globfree(&globdata);
2340 /* Performs globbing on last list[],
2341 * saving each result as a new list[].
2343 static int perform_glob(o_string *o, int n)
2345 char *pattern, *copy;
2347 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2349 return o_save_ptr_helper(o, n);
2350 pattern = o->data + o_get_last_ptr(o, n);
2351 debug_printf_glob("glob pattern '%s'\n", pattern);
2352 if (!glob_needed(pattern)) {
2353 /* unbackslash last string in o in place, fix length */
2354 o->length = unbackslash(pattern) - o->data;
2355 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2356 return o_save_ptr_helper(o, n);
2359 copy = xstrdup(pattern);
2360 /* "forget" pattern in o */
2361 o->length = pattern - o->data;
2362 n = glob_brace(copy, o, n);
2365 debug_print_list("perform_glob returning", o, n);
2369 #else /* !HUSH_BRACE_EXP */
2372 static int glob_needed(const char *s)
2381 if (*s == '*' || *s == '[' || *s == '?')
2387 /* Performs globbing on last list[],
2388 * saving each result as a new list[].
2390 static int perform_glob(o_string *o, int n)
2396 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2398 return o_save_ptr_helper(o, n);
2399 pattern = o->data + o_get_last_ptr(o, n);
2400 debug_printf_glob("glob pattern '%s'\n", pattern);
2401 if (!glob_needed(pattern)) {
2403 /* unbackslash last string in o in place, fix length */
2404 o->length = unbackslash(pattern) - o->data;
2405 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2406 return o_save_ptr_helper(o, n);
2409 memset(&globdata, 0, sizeof(globdata));
2410 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2411 * If we glob "*.\*" and don't find anything, we need
2412 * to fall back to using literal "*.*", but GLOB_NOCHECK
2413 * will return "*.\*"!
2415 gr = glob(pattern, 0, NULL, &globdata);
2416 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2418 if (gr == GLOB_NOMATCH) {
2419 globfree(&globdata);
2422 if (gr == GLOB_NOSPACE)
2423 bb_error_msg_and_die(bb_msg_memory_exhausted);
2424 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2425 * but we didn't specify it. Paranoia again. */
2426 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2428 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2429 char **argv = globdata.gl_pathv;
2430 /* "forget" pattern in o */
2431 o->length = pattern - o->data;
2433 o_addstr_with_NUL(o, *argv);
2434 n = o_save_ptr_helper(o, n);
2440 globfree(&globdata);
2442 debug_print_list("perform_glob returning", o, n);
2446 #endif /* !HUSH_BRACE_EXP */
2448 /* If o->o_glob == 1, glob the string so far remembered.
2449 * Otherwise, just finish current list[] and start new */
2450 static int o_save_ptr(o_string *o, int n)
2452 if (o->o_glob) { /* if globbing is requested */
2453 /* If o->has_empty_slot, list[n] was already globbed
2454 * (if it was requested back then when it was filled)
2455 * so don't do that again! */
2456 if (!o->has_empty_slot)
2457 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2459 return o_save_ptr_helper(o, n);
2462 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2463 static char **o_finalize_list(o_string *o, int n)
2468 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2470 debug_print_list("finalized", o, n);
2471 debug_printf_expand("finalized n:%d\n", n);
2472 list = (char**)o->data;
2473 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2477 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2482 static void free_pipe_list(struct pipe *pi);
2484 /* Returns pi->next - next pipe in the list */
2485 static struct pipe *free_pipe(struct pipe *pi)
2490 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2491 for (i = 0; i < pi->num_cmds; i++) {
2492 struct command *command;
2493 struct redir_struct *r, *rnext;
2495 command = &pi->cmds[i];
2496 debug_printf_clean(" command %d:\n", i);
2497 if (command->argv) {
2501 for (a = 0, p = command->argv; *p; a++, p++) {
2502 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2505 free_strings(command->argv);
2506 //command->argv = NULL;
2508 /* not "else if": on syntax error, we may have both! */
2509 if (command->group) {
2510 debug_printf_clean(" begin group (cmd_type:%d)\n",
2512 free_pipe_list(command->group);
2513 debug_printf_clean(" end group\n");
2514 //command->group = NULL;
2516 /* else is crucial here.
2517 * If group != NULL, child_func is meaningless */
2518 #if ENABLE_HUSH_FUNCTIONS
2519 else if (command->child_func) {
2520 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2521 command->child_func->parent_cmd = NULL;
2525 free(command->group_as_string);
2526 //command->group_as_string = NULL;
2528 for (r = command->redirects; r; r = rnext) {
2529 debug_printf_clean(" redirect %d%s",
2530 r->rd_fd, redir_table[r->rd_type].descrip);
2531 /* guard against the case >$FOO, where foo is unset or blank */
2532 if (r->rd_filename) {
2533 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2534 free(r->rd_filename);
2535 //r->rd_filename = NULL;
2537 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2541 //command->redirects = NULL;
2543 free(pi->cmds); /* children are an array, they get freed all at once */
2547 //pi->cmdtext = NULL;
2555 static void free_pipe_list(struct pipe *pi)
2559 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2561 debug_printf_clean("pipe followup code %d\n", pi->followup);
2567 /*** Parsing routines ***/
2569 static struct pipe *new_pipe(void)
2572 pi = xzalloc(sizeof(struct pipe));
2573 /*pi->followup = 0; - deliberately invalid value */
2574 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2578 /* Command (member of a pipe) is complete, or we start a new pipe
2579 * if ctx->command is NULL.
2580 * No errors possible here.
2582 static int done_command(struct parse_context *ctx)
2584 /* The command is really already in the pipe structure, so
2585 * advance the pipe counter and make a new, null command. */
2586 struct pipe *pi = ctx->pipe;
2587 struct command *command = ctx->command;
2590 if (IS_NULL_CMD(command)) {
2591 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2595 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2596 //debug_print_tree(ctx->list_head, 20);
2598 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2601 /* Only real trickiness here is that the uncommitted
2602 * command structure is not counted in pi->num_cmds. */
2603 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2604 ctx->command = command = &pi->cmds[pi->num_cmds];
2606 memset(command, 0, sizeof(*command));
2607 return pi->num_cmds; /* used only for 0/nonzero check */
2610 static void done_pipe(struct parse_context *ctx, pipe_style type)
2614 debug_printf_parse("done_pipe entered, followup %d\n", type);
2615 /* Close previous command */
2616 not_null = done_command(ctx);
2617 ctx->pipe->followup = type;
2619 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2620 ctx->ctx_inverted = 0;
2621 ctx->pipe->res_word = ctx->ctx_res_w;
2624 /* Without this check, even just <enter> on command line generates
2625 * tree of three NOPs (!). Which is harmless but annoying.
2626 * IOW: it is safe to do it unconditionally. */
2629 || ctx->ctx_res_w == RES_FI
2631 #if ENABLE_HUSH_LOOPS
2632 || ctx->ctx_res_w == RES_DONE
2633 || ctx->ctx_res_w == RES_FOR
2634 || ctx->ctx_res_w == RES_IN
2636 #if ENABLE_HUSH_CASE
2637 || ctx->ctx_res_w == RES_ESAC
2641 debug_printf_parse("done_pipe: adding new pipe: "
2642 "not_null:%d ctx->ctx_res_w:%d\n",
2643 not_null, ctx->ctx_res_w);
2645 ctx->pipe->next = new_p;
2647 /* RES_THEN, RES_DO etc are "sticky" -
2648 * they remain set for pipes inside if/while.
2649 * This is used to control execution.
2650 * RES_FOR and RES_IN are NOT sticky (needed to support
2651 * cases where variable or value happens to match a keyword):
2653 #if ENABLE_HUSH_LOOPS
2654 if (ctx->ctx_res_w == RES_FOR
2655 || ctx->ctx_res_w == RES_IN)
2656 ctx->ctx_res_w = RES_NONE;
2658 #if ENABLE_HUSH_CASE
2659 if (ctx->ctx_res_w == RES_MATCH)
2660 ctx->ctx_res_w = RES_CASE_BODY;
2661 if (ctx->ctx_res_w == RES_CASE)
2662 ctx->ctx_res_w = RES_CASE_IN;
2664 ctx->command = NULL; /* trick done_command below */
2665 /* Create the memory for command, roughly:
2666 * ctx->pipe->cmds = new struct command;
2667 * ctx->command = &ctx->pipe->cmds[0];
2670 //debug_print_tree(ctx->list_head, 10);
2672 debug_printf_parse("done_pipe return\n");
2675 static void initialize_context(struct parse_context *ctx)
2677 memset(ctx, 0, sizeof(*ctx));
2678 ctx->pipe = ctx->list_head = new_pipe();
2679 /* Create the memory for command, roughly:
2680 * ctx->pipe->cmds = new struct command;
2681 * ctx->command = &ctx->pipe->cmds[0];
2686 /* If a reserved word is found and processed, parse context is modified
2687 * and 1 is returned.
2690 struct reserved_combo {
2693 unsigned char assignment_flag;
2697 FLAG_END = (1 << RES_NONE ),
2699 FLAG_IF = (1 << RES_IF ),
2700 FLAG_THEN = (1 << RES_THEN ),
2701 FLAG_ELIF = (1 << RES_ELIF ),
2702 FLAG_ELSE = (1 << RES_ELSE ),
2703 FLAG_FI = (1 << RES_FI ),
2705 # if ENABLE_HUSH_LOOPS
2706 FLAG_FOR = (1 << RES_FOR ),
2707 FLAG_WHILE = (1 << RES_WHILE),
2708 FLAG_UNTIL = (1 << RES_UNTIL),
2709 FLAG_DO = (1 << RES_DO ),
2710 FLAG_DONE = (1 << RES_DONE ),
2711 FLAG_IN = (1 << RES_IN ),
2713 # if ENABLE_HUSH_CASE
2714 FLAG_MATCH = (1 << RES_MATCH),
2715 FLAG_ESAC = (1 << RES_ESAC ),
2717 FLAG_START = (1 << RES_XXXX ),
2720 static const struct reserved_combo* match_reserved_word(o_string *word)
2722 /* Mostly a list of accepted follow-up reserved words.
2723 * FLAG_END means we are done with the sequence, and are ready
2724 * to turn the compound list into a command.
2725 * FLAG_START means the word must start a new compound list.
2727 static const struct reserved_combo reserved_list[] = {
2729 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
2730 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
2731 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2732 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
2733 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
2734 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
2736 # if ENABLE_HUSH_LOOPS
2737 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
2738 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2739 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2740 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
2741 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
2742 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
2744 # if ENABLE_HUSH_CASE
2745 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
2746 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
2749 const struct reserved_combo *r;
2751 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2752 if (strcmp(word->data, r->literal) == 0)
2757 /* Return 0: not a keyword, 1: keyword
2759 static int reserved_word(o_string *word, struct parse_context *ctx)
2761 # if ENABLE_HUSH_CASE
2762 static const struct reserved_combo reserved_match = {
2763 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
2766 const struct reserved_combo *r;
2768 if (word->has_quoted_part)
2770 r = match_reserved_word(word);
2774 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2775 # if ENABLE_HUSH_CASE
2776 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
2777 /* "case word IN ..." - IN part starts first MATCH part */
2778 r = &reserved_match;
2781 if (r->flag == 0) { /* '!' */
2782 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
2783 syntax_error("! ! command");
2784 ctx->ctx_res_w = RES_SNTX;
2786 ctx->ctx_inverted = 1;
2789 if (r->flag & FLAG_START) {
2790 struct parse_context *old;
2792 old = xmalloc(sizeof(*old));
2793 debug_printf_parse("push stack %p\n", old);
2794 *old = *ctx; /* physical copy */
2795 initialize_context(ctx);
2797 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
2798 syntax_error_at(word->data);
2799 ctx->ctx_res_w = RES_SNTX;
2802 /* "{...} fi" is ok. "{...} if" is not
2804 * if { echo foo; } then { echo bar; } fi */
2805 if (ctx->command->group)
2806 done_pipe(ctx, PIPE_SEQ);
2809 ctx->ctx_res_w = r->res;
2810 ctx->old_flag = r->flag;
2811 word->o_assignment = r->assignment_flag;
2813 if (ctx->old_flag & FLAG_END) {
2814 struct parse_context *old;
2816 done_pipe(ctx, PIPE_SEQ);
2817 debug_printf_parse("pop stack %p\n", ctx->stack);
2819 old->command->group = ctx->list_head;
2820 old->command->cmd_type = CMD_NORMAL;
2822 o_addstr(&old->as_string, ctx->as_string.data);
2823 o_free_unsafe(&ctx->as_string);
2824 old->command->group_as_string = xstrdup(old->as_string.data);
2825 debug_printf_parse("pop, remembering as:'%s'\n",
2826 old->command->group_as_string);
2828 *ctx = *old; /* physical copy */
2833 #endif /* HAS_KEYWORDS */
2835 /* Word is complete, look at it and update parsing context.
2836 * Normal return is 0. Syntax errors return 1.
2837 * Note: on return, word is reset, but not o_free'd!
2839 static int done_word(o_string *word, struct parse_context *ctx)
2841 struct command *command = ctx->command;
2843 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
2844 if (word->length == 0 && !word->has_quoted_part) {
2845 debug_printf_parse("done_word return 0: true null, ignored\n");
2849 if (ctx->pending_redirect) {
2850 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
2851 * only if run as "bash", not "sh" */
2852 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
2854 * ...the word that follows the redirection operator
2855 * shall be subjected to tilde expansion, parameter expansion,
2856 * command substitution, arithmetic expansion, and quote
2857 * removal. Pathname expansion shall not be performed
2858 * on the word by a non-interactive shell; an interactive
2859 * shell may perform it, but shall do so only when
2860 * the expansion would result in one word."
2862 ctx->pending_redirect->rd_filename = xstrdup(word->data);
2863 /* Cater for >\file case:
2864 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
2865 * Same with heredocs:
2866 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
2868 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
2869 unbackslash(ctx->pending_redirect->rd_filename);
2870 /* Is it <<"HEREDOC"? */
2871 if (word->has_quoted_part) {
2872 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
2875 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
2876 ctx->pending_redirect = NULL;
2878 /* If this word wasn't an assignment, next ones definitely
2879 * can't be assignments. Even if they look like ones. */
2880 if (word->o_assignment != DEFINITELY_ASSIGNMENT
2881 && word->o_assignment != WORD_IS_KEYWORD
2883 word->o_assignment = NOT_ASSIGNMENT;
2885 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
2886 command->assignment_cnt++;
2887 word->o_assignment = MAYBE_ASSIGNMENT;
2891 # if ENABLE_HUSH_CASE
2892 if (ctx->ctx_dsemicolon
2893 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
2895 /* already done when ctx_dsemicolon was set to 1: */
2896 /* ctx->ctx_res_w = RES_MATCH; */
2897 ctx->ctx_dsemicolon = 0;
2900 if (!command->argv /* if it's the first word... */
2901 # if ENABLE_HUSH_LOOPS
2902 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
2903 && ctx->ctx_res_w != RES_IN
2905 # if ENABLE_HUSH_CASE
2906 && ctx->ctx_res_w != RES_CASE
2909 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
2910 if (reserved_word(word, ctx)) {
2911 o_reset_to_empty_unquoted(word);
2912 debug_printf_parse("done_word return %d\n",
2913 (ctx->ctx_res_w == RES_SNTX));
2914 return (ctx->ctx_res_w == RES_SNTX);
2916 # if ENABLE_HUSH_BASH_COMPAT
2917 if (strcmp(word->data, "[[") == 0) {
2918 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
2924 if (command->group) {
2925 /* "{ echo foo; } echo bar" - bad */
2926 syntax_error_at(word->data);
2927 debug_printf_parse("done_word return 1: syntax error, "
2928 "groups and arglists don't mix\n");
2931 if (word->has_quoted_part
2932 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
2933 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
2934 /* (otherwise it's known to be not empty and is already safe) */
2936 /* exclude "$@" - it can expand to no word despite "" */
2937 char *p = word->data;
2938 while (p[0] == SPECIAL_VAR_SYMBOL
2939 && (p[1] & 0x7f) == '@'
2940 && p[2] == SPECIAL_VAR_SYMBOL
2944 if (p == word->data || p[0] != '\0') {
2945 /* saw no "$@", or not only "$@" but some
2946 * real text is there too */
2947 /* insert "empty variable" reference, this makes
2948 * e.g. "", $empty"" etc to not disappear */
2949 o_addchr(word, SPECIAL_VAR_SYMBOL);
2950 o_addchr(word, SPECIAL_VAR_SYMBOL);
2953 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
2954 debug_print_strings("word appended to argv", command->argv);
2957 #if ENABLE_HUSH_LOOPS
2958 if (ctx->ctx_res_w == RES_FOR) {
2959 if (word->has_quoted_part
2960 || !is_well_formed_var_name(command->argv[0], '\0')
2962 /* bash says just "not a valid identifier" */
2963 syntax_error("not a valid identifier in for");
2966 /* Force FOR to have just one word (variable name) */
2967 /* NB: basically, this makes hush see "for v in ..."
2968 * syntax as if it is "for v; in ...". FOR and IN become
2969 * two pipe structs in parse tree. */
2970 done_pipe(ctx, PIPE_SEQ);
2973 #if ENABLE_HUSH_CASE
2974 /* Force CASE to have just one word */
2975 if (ctx->ctx_res_w == RES_CASE) {
2976 done_pipe(ctx, PIPE_SEQ);
2980 o_reset_to_empty_unquoted(word);
2982 debug_printf_parse("done_word return 0\n");
2987 /* Peek ahead in the input to find out if we have a "&n" construct,
2988 * as in "2>&1", that represents duplicating a file descriptor.
2990 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
2991 * REDIRFD_SYNTAX_ERR if syntax error,
2992 * REDIRFD_TO_FILE if no & was seen,
2993 * or the number found.
2996 #define parse_redir_right_fd(as_string, input) \
2997 parse_redir_right_fd(input)
2999 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3005 return REDIRFD_TO_FILE;
3007 ch = i_getch(input); /* get the & */
3008 nommu_addchr(as_string, ch);
3011 ch = i_getch(input);
3012 nommu_addchr(as_string, ch);
3013 return REDIRFD_CLOSE;
3017 while (ch != EOF && isdigit(ch)) {
3018 d = d*10 + (ch-'0');
3020 ch = i_getch(input);
3021 nommu_addchr(as_string, ch);
3026 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3028 bb_error_msg("ambiguous redirect");
3029 return REDIRFD_SYNTAX_ERR;
3032 /* Return code is 0 normal, 1 if a syntax error is detected
3034 static int parse_redirect(struct parse_context *ctx,
3037 struct in_str *input)
3039 struct command *command = ctx->command;
3040 struct redir_struct *redir;
3041 struct redir_struct **redirp;
3044 dup_num = REDIRFD_TO_FILE;
3045 if (style != REDIRECT_HEREDOC) {
3046 /* Check for a '>&1' type redirect */
3047 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3048 if (dup_num == REDIRFD_SYNTAX_ERR)
3051 int ch = i_peek(input);
3052 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3053 if (dup_num) { /* <<-... */
3054 ch = i_getch(input);
3055 nommu_addchr(&ctx->as_string, ch);
3060 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3061 int ch = i_peek(input);
3063 /* >|FILE redirect ("clobbering" >).
3064 * Since we do not support "set -o noclobber" yet,
3065 * >| and > are the same for now. Just eat |.
3067 ch = i_getch(input);
3068 nommu_addchr(&ctx->as_string, ch);
3072 /* Create a new redir_struct and append it to the linked list */
3073 redirp = &command->redirects;
3074 while ((redir = *redirp) != NULL) {
3075 redirp = &(redir->next);
3077 *redirp = redir = xzalloc(sizeof(*redir));
3078 /* redir->next = NULL; */
3079 /* redir->rd_filename = NULL; */
3080 redir->rd_type = style;
3081 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3083 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3084 redir_table[style].descrip);
3086 redir->rd_dup = dup_num;
3087 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3088 /* Erik had a check here that the file descriptor in question
3089 * is legit; I postpone that to "run time"
3090 * A "-" representation of "close me" shows up as a -3 here */
3091 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3092 redir->rd_fd, redir->rd_dup);
3094 /* Set ctx->pending_redirect, so we know what to do at the
3095 * end of the next parsed word. */
3096 ctx->pending_redirect = redir;
3101 /* If a redirect is immediately preceded by a number, that number is
3102 * supposed to tell which file descriptor to redirect. This routine
3103 * looks for such preceding numbers. In an ideal world this routine
3104 * needs to handle all the following classes of redirects...
3105 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3106 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3107 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3108 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3110 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3112 * ... If n is quoted, the number shall not be recognized as part of
3113 * the redirection expression. For example:
3115 * writes the character 2 into file a"
3116 * We are getting it right by setting ->has_quoted_part on any \<char>
3118 * A -1 return means no valid number was found,
3119 * the caller should use the appropriate default for this redirection.
3121 static int redirect_opt_num(o_string *o)
3125 if (o->data == NULL)
3127 num = bb_strtou(o->data, NULL, 10);
3128 if (errno || num < 0)
3130 o_reset_to_empty_unquoted(o);
3135 #define fetch_till_str(as_string, input, word, skip_tabs) \
3136 fetch_till_str(input, word, skip_tabs)
3138 static char *fetch_till_str(o_string *as_string,
3139 struct in_str *input,
3143 o_string heredoc = NULL_O_STRING;
3145 int prev = 0; /* not \ */
3150 ch = i_getch(input);
3151 nommu_addchr(as_string, ch);
3153 /* TODO: or EOF? (heredoc delimiter may end with <eof>, not only <eol>) */
3154 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3156 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3157 heredoc.data[past_EOL] = '\0';
3158 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3159 return heredoc.data;
3162 o_addchr(&heredoc, '\n');
3163 prev = 0; /* not \ */
3164 past_EOL = heredoc.length;
3167 ch = i_getch(input);
3168 nommu_addchr(as_string, ch);
3169 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3170 } while (ch == '\n');
3173 o_free_unsafe(&heredoc);
3176 o_addchr(&heredoc, ch);
3177 if (prev == '\\' && ch == '\\')
3178 /* Correctly handle foo\\<eol> (not a line cont.) */
3179 prev = 0; /* not \ */
3182 nommu_addchr(as_string, ch);
3186 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3187 * and load them all. There should be exactly heredoc_cnt of them.
3189 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3191 struct pipe *pi = ctx->list_head;
3193 while (pi && heredoc_cnt) {
3195 struct command *cmd = pi->cmds;
3197 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3199 cmd->argv ? cmd->argv[0] : "NONE");
3200 for (i = 0; i < pi->num_cmds; i++) {
3201 struct redir_struct *redir = cmd->redirects;
3203 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3204 i, cmd->argv ? cmd->argv[0] : "NONE");
3206 if (redir->rd_type == REDIRECT_HEREDOC) {
3209 redir->rd_type = REDIRECT_HEREDOC2;
3210 /* redir->rd_dup is (ab)used to indicate <<- */
3211 p = fetch_till_str(&ctx->as_string, input,
3212 redir->rd_filename, redir->rd_dup);
3214 syntax_error("unexpected EOF in here document");
3217 free(redir->rd_filename);
3218 redir->rd_filename = p;
3221 redir = redir->next;
3228 /* Should be 0. If it isn't, it's a parse error */
3230 bb_error_msg_and_die("heredoc BUG 2");
3236 static int run_list(struct pipe *pi);
3238 #define parse_stream(pstring, input, end_trigger) \
3239 parse_stream(input, end_trigger)
3241 static struct pipe *parse_stream(char **pstring,
3242 struct in_str *input,
3246 #if !ENABLE_HUSH_FUNCTIONS
3247 #define parse_group(dest, ctx, input, ch) \
3248 parse_group(ctx, input, ch)
3250 static int parse_group(o_string *dest, struct parse_context *ctx,
3251 struct in_str *input, int ch)
3253 /* dest contains characters seen prior to ( or {.
3254 * Typically it's empty, but for function defs,
3255 * it contains function name (without '()'). */
3256 struct pipe *pipe_list;
3258 struct command *command = ctx->command;
3260 debug_printf_parse("parse_group entered\n");
3261 #if ENABLE_HUSH_FUNCTIONS
3262 if (ch == '(' && !dest->has_quoted_part) {
3264 if (done_word(dest, ctx))
3267 goto skip; /* (... */
3268 if (command->argv[1]) { /* word word ... (... */
3269 syntax_error_unexpected_ch('(');
3272 /* it is "word(..." or "word (..." */
3274 ch = i_getch(input);
3275 while (ch == ' ' || ch == '\t');
3277 syntax_error_unexpected_ch(ch);
3280 nommu_addchr(&ctx->as_string, ch);
3282 ch = i_getch(input);
3283 while (ch == ' ' || ch == '\t' || ch == '\n');
3285 syntax_error_unexpected_ch(ch);
3288 nommu_addchr(&ctx->as_string, ch);
3289 command->cmd_type = CMD_FUNCDEF;
3294 #if 0 /* Prevented by caller */
3295 if (command->argv /* word [word]{... */
3296 || dest->length /* word{... */
3297 || dest->has_quoted_part /* ""{... */
3300 debug_printf_parse("parse_group return 1: "
3301 "syntax error, groups and arglists don't mix\n");
3306 #if ENABLE_HUSH_FUNCTIONS
3312 command->cmd_type = CMD_SUBSHELL;
3314 /* bash does not allow "{echo...", requires whitespace */
3315 ch = i_getch(input);
3316 if (ch != ' ' && ch != '\t' && ch != '\n') {
3317 syntax_error_unexpected_ch(ch);
3320 nommu_addchr(&ctx->as_string, ch);
3325 # define as_string NULL
3327 char *as_string = NULL;
3329 pipe_list = parse_stream(&as_string, input, endch);
3332 o_addstr(&ctx->as_string, as_string);
3334 /* empty ()/{} or parse error? */
3335 if (!pipe_list || pipe_list == ERR_PTR) {
3336 /* parse_stream already emitted error msg */
3339 debug_printf_parse("parse_group return 1: "
3340 "parse_stream returned %p\n", pipe_list);
3343 command->group = pipe_list;
3345 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3346 command->group_as_string = as_string;
3347 debug_printf_parse("end of group, remembering as:'%s'\n",
3348 command->group_as_string);
3352 debug_printf_parse("parse_group return 0\n");
3354 /* command remains "open", available for possible redirects */
3357 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3358 /* Subroutines for copying $(...) and `...` things */
3359 static void add_till_backquote(o_string *dest, struct in_str *input);
3361 static void add_till_single_quote(o_string *dest, struct in_str *input)
3364 int ch = i_getch(input);
3366 syntax_error_unterm_ch('\'');
3367 /*xfunc_die(); - redundant */
3374 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3375 static void add_till_double_quote(o_string *dest, struct in_str *input)
3378 int ch = i_getch(input);
3380 syntax_error_unterm_ch('"');
3381 /*xfunc_die(); - redundant */
3385 if (ch == '\\') { /* \x. Copy both chars. */
3387 ch = i_getch(input);
3391 add_till_backquote(dest, input);
3395 //if (ch == '$') ...
3398 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3400 * "Within the backquoted style of command substitution, backslash
3401 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3402 * The search for the matching backquote shall be satisfied by the first
3403 * backquote found without a preceding backslash; during this search,
3404 * if a non-escaped backquote is encountered within a shell comment,
3405 * a here-document, an embedded command substitution of the $(command)
3406 * form, or a quoted string, undefined results occur. A single-quoted
3407 * or double-quoted string that begins, but does not end, within the
3408 * "`...`" sequence produces undefined results."
3410 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3412 static void add_till_backquote(o_string *dest, struct in_str *input)
3415 int ch = i_getch(input);
3417 syntax_error_unterm_ch('`');
3418 /*xfunc_die(); - redundant */
3423 /* \x. Copy both chars unless it is \` */
3424 int ch2 = i_getch(input);
3426 syntax_error_unterm_ch('`');
3427 /*xfunc_die(); - redundant */
3429 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3436 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3437 * quoting and nested ()s.
3438 * "With the $(command) style of command substitution, all characters
3439 * following the open parenthesis to the matching closing parenthesis
3440 * constitute the command. Any valid shell script can be used for command,
3441 * except a script consisting solely of redirections which produces
3442 * unspecified results."
3444 * echo $(echo '(TEST)' BEST) (TEST) BEST
3445 * echo $(echo 'TEST)' BEST) TEST) BEST
3446 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3448 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3449 * can contain arbitrary constructs, just like $(cmd).
3450 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3451 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3453 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3454 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3457 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3458 # if ENABLE_HUSH_BASH_COMPAT
3459 char end_char2 = end_ch >> 8;
3461 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3464 ch = i_getch(input);
3466 syntax_error_unterm_ch(end_ch);
3467 /*xfunc_die(); - redundant */
3469 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3472 /* we look for closing )) of $((EXPR)) */
3473 if (i_peek(input) == end_ch) {
3474 i_getch(input); /* eat second ')' */
3479 if (ch == '(' || ch == '{') {
3480 ch = (ch == '(' ? ')' : '}');
3481 add_till_closing_bracket(dest, input, ch);
3486 add_till_single_quote(dest, input);
3491 add_till_double_quote(dest, input);
3496 add_till_backquote(dest, input);
3501 /* \x. Copy verbatim. Important for \(, \) */
3502 ch = i_getch(input);
3504 syntax_error_unterm_ch(')');
3505 /*xfunc_die(); - redundant */
3513 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3515 /* Return code: 0 for OK, 1 for syntax error */
3517 #define parse_dollar(as_string, dest, input) \
3518 parse_dollar(dest, input)
3519 #define as_string NULL
3521 static int parse_dollar(o_string *as_string,
3523 struct in_str *input)
3525 int ch = i_peek(input); /* first character after the $ */
3526 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
3528 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3530 ch = i_getch(input);
3531 nommu_addchr(as_string, ch);
3533 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3535 debug_printf_parse(": '%c'\n", ch);
3536 o_addchr(dest, ch | quote_mask);
3539 if (!isalnum(ch) && ch != '_')
3541 ch = i_getch(input);
3542 nommu_addchr(as_string, ch);
3544 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3545 } else if (isdigit(ch)) {
3547 ch = i_getch(input);
3548 nommu_addchr(as_string, ch);
3549 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3550 debug_printf_parse(": '%c'\n", ch);
3551 o_addchr(dest, ch | quote_mask);
3552 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3553 } else switch (ch) {
3555 case '!': /* last bg pid */
3556 case '?': /* last exit code */
3557 case '#': /* number of args */
3558 case '*': /* args */
3559 case '@': /* args */
3560 goto make_one_char_var;
3562 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3564 ch = i_getch(input); /* eat '{' */
3565 nommu_addchr(as_string, ch);
3567 ch = i_getch(input); /* first char after '{' */
3568 nommu_addchr(as_string, ch);
3569 /* It should be ${?}, or ${#var},
3570 * or even ${?+subst} - operator acting on a special variable,
3571 * or the beginning of variable name.
3573 if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
3575 syntax_error_unterm_str("${name}");
3576 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
3581 /* It's possible to just call add_till_closing_bracket() at this point.
3582 * However, this regresses some of our testsuite cases
3583 * which check invalid constructs like ${%}.
3584 * Oh well... let's check that the var name part is fine... */
3590 debug_printf_parse(": '%c'\n", ch);
3592 ch = i_getch(input);
3593 nommu_addchr(as_string, ch);
3597 if (!isalnum(ch) && ch != '_') {
3599 unsigned char last_ch;
3600 /* handle parameter expansions
3601 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3603 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3604 goto bad_dollar_syntax;
3606 /* Eat everything until closing '}' (or ':') */
3608 if (ENABLE_HUSH_BASH_COMPAT
3610 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3612 /* It's ${var:N[:M]} thing */
3613 end_ch = '}' * 0x100 + ':';
3615 if (ENABLE_HUSH_BASH_COMPAT
3618 /* It's ${var/[/]pattern[/repl]} thing */
3619 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3621 nommu_addchr(as_string, '/');
3624 end_ch = '}' * 0x100 + '/';
3630 #if ENABLE_HUSH_DOLLAR_OPS
3631 last_ch = add_till_closing_bracket(dest, input, end_ch);
3633 #error Simple code to only allow ${var} is not implemented
3636 o_addstr(as_string, dest->data + pos);
3637 o_addchr(as_string, last_ch);
3640 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3641 /* close the first block: */
3642 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3643 /* while parsing N from ${var:N[:M]}
3644 * or pattern from ${var/[/]pattern[/repl]} */
3645 if ((end_ch & 0xff) == last_ch) {
3646 /* got ':' or '/'- parse the rest */
3651 if (end_ch == '}' * 0x100 + ':') {
3652 /* it's ${var:N} - emulate :999999999 */
3653 o_addstr(dest, "999999999");
3654 } /* else: it's ${var/[/]pattern} */
3659 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3662 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3666 ch = i_getch(input);
3667 nommu_addchr(as_string, ch);
3668 # if ENABLE_SH_MATH_SUPPORT
3669 if (i_peek(input) == '(') {
3670 ch = i_getch(input);
3671 nommu_addchr(as_string, ch);
3672 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3673 o_addchr(dest, /*quote_mask |*/ '+');
3676 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
3678 o_addstr(as_string, dest->data + pos);
3679 o_addchr(as_string, ')');
3680 o_addchr(as_string, ')');
3682 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3686 # if ENABLE_HUSH_TICK
3687 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3688 o_addchr(dest, quote_mask | '`');
3691 add_till_closing_bracket(dest, input, ')');
3693 o_addstr(as_string, dest->data + pos);
3694 o_addchr(as_string, ')');
3696 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3702 ch = i_getch(input);
3703 nommu_addchr(as_string, ch);
3705 if (isalnum(ch)) { /* it's $_name or $_123 */
3710 /* TODO: $_ and $-: */
3711 /* $_ Shell or shell script name; or last argument of last command
3712 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
3713 * but in command's env, set to full pathname used to invoke it */
3714 /* $- Option flags set by set builtin or shell options (-i etc) */
3716 o_addQchr(dest, '$');
3718 debug_printf_parse("parse_dollar return 0\n");
3724 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
3725 parse_stream_dquoted(dest, input, dquote_end)
3726 #define as_string NULL
3728 static int parse_stream_dquoted(o_string *as_string,
3730 struct in_str *input,
3737 ch = i_getch(input);
3739 nommu_addchr(as_string, ch);
3740 if (ch == dquote_end) { /* may be only '"' or EOF */
3741 if (dest->o_assignment == NOT_ASSIGNMENT)
3742 dest->o_escape ^= 1;
3743 debug_printf_parse("parse_stream_dquoted return 0\n");
3746 /* note: can't move it above ch == dquote_end check! */
3748 syntax_error_unterm_ch('"');
3749 /*xfunc_die(); - redundant */
3753 next = i_peek(input);
3755 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
3756 ch, ch, dest->o_escape);
3759 syntax_error("\\<eof>");
3763 * "The backslash retains its special meaning [in "..."]
3764 * only when followed by one of the following characters:
3765 * $, `, ", \, or <newline>. A double quote may be quoted
3766 * within double quotes by preceding it with a backslash."
3767 * NB: in (unquoted) heredoc, above does not apply to ".
3769 if (next == dquote_end || strchr("$`\\\n", next) != NULL) {
3770 ch = i_getch(input);
3772 o_addqchr(dest, ch);
3773 nommu_addchr(as_string, ch);
3776 o_addqchr(dest, '\\');
3777 nommu_addchr(as_string, '\\');
3782 if (parse_dollar(as_string, dest, input) != 0) {
3783 debug_printf_parse("parse_stream_dquoted return 1: "
3784 "parse_dollar returned non-0\n");
3789 #if ENABLE_HUSH_TICK
3791 //unsigned pos = dest->length;
3792 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3793 o_addchr(dest, 0x80 | '`');
3794 add_till_backquote(dest, input);
3795 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3796 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3800 o_addQchr(dest, ch);
3802 && (dest->o_assignment == MAYBE_ASSIGNMENT
3803 || dest->o_assignment == WORD_IS_KEYWORD)
3804 && is_well_formed_var_name(dest->data, '=')
3806 dest->o_assignment = DEFINITELY_ASSIGNMENT;
3813 * Scan input until EOF or end_trigger char.
3814 * Return a list of pipes to execute, or NULL on EOF
3815 * or if end_trigger character is met.
3816 * On syntax error, exit is shell is not interactive,
3817 * reset parsing machinery and start parsing anew,
3818 * or return ERR_PTR.
3820 static struct pipe *parse_stream(char **pstring,
3821 struct in_str *input,
3824 struct parse_context ctx;
3825 o_string dest = NULL_O_STRING;
3829 /* Double-quote state is handled in the state variable is_in_dquote.
3830 * A single-quote triggers a bypass of the main loop until its mate is
3831 * found. When recursing, quote state is passed in via dest->o_escape.
3833 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
3834 end_trigger ? end_trigger : 'X');
3837 /* If very first arg is "" or '', dest.data may end up NULL.
3838 * Preventing this: */
3839 o_addchr(&dest, '\0');
3842 G.ifs = get_local_var_value("IFS");
3847 #if ENABLE_HUSH_INTERACTIVE
3848 input->promptmode = 0; /* PS1 */
3850 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
3851 initialize_context(&ctx);
3856 const char *is_special;
3860 redir_type redir_style;
3863 /* dest.has_quoted_part = 1; - already is (see below) */
3864 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
3867 /* We reached closing '"' */
3870 ch = i_getch(input);
3871 debug_printf_parse(": ch=%c (%d) escape=%d\n",
3872 ch, ch, dest.o_escape);
3877 syntax_error_unterm_str("here document");
3880 /* end_trigger == '}' case errors out earlier,
3881 * checking only ')' */
3882 if (end_trigger == ')') {
3883 syntax_error_unterm_ch('('); /* exits */
3884 /* goto parse_error; */
3887 if (done_word(&dest, &ctx)) {
3891 done_pipe(&ctx, PIPE_SEQ);
3893 /* If we got nothing... */
3894 /* (this makes bare "&" cmd a no-op.
3895 * bash says: "syntax error near unexpected token '&'") */
3896 if (pi->num_cmds == 0
3897 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
3903 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
3905 *pstring = ctx.as_string.data;
3907 o_free_unsafe(&ctx.as_string);
3910 debug_printf_parse("parse_stream return %p\n", pi);
3913 nommu_addchr(&ctx.as_string, ch);
3917 next = i_peek(input);
3919 is_special = "{}<>;&|()#'" /* special outside of "str" */
3920 "\\$\"" IF_HUSH_TICK("`"); /* always special */
3921 /* Are { and } special here? */
3922 if (ctx.command->argv /* word [word]{... - non-special */
3923 || dest.length /* word{... - non-special */
3924 || dest.has_quoted_part /* ""{... - non-special */
3925 || (next != ';' /* }; - special */
3926 && next != ')' /* }) - special */
3927 && next != '&' /* }& and }&& ... - special */
3928 && next != '|' /* }|| ... - special */
3929 && !strchr(G.ifs, next) /* {word - non-special */
3932 /* They are not special, skip "{}" */
3935 is_special = strchr(is_special, ch);
3936 is_ifs = strchr(G.ifs, ch);
3938 if (!is_special && !is_ifs) { /* ordinary char */
3940 o_addQchr(&dest, ch);
3941 if ((dest.o_assignment == MAYBE_ASSIGNMENT
3942 || dest.o_assignment == WORD_IS_KEYWORD)
3944 && is_well_formed_var_name(dest.data, '=')
3946 dest.o_assignment = DEFINITELY_ASSIGNMENT;
3952 if (done_word(&dest, &ctx)) {
3956 #if ENABLE_HUSH_CASE
3957 /* "case ... in <newline> word) ..." -
3958 * newlines are ignored (but ';' wouldn't be) */
3959 if (ctx.command->argv == NULL
3960 && ctx.ctx_res_w == RES_MATCH
3965 /* Treat newline as a command separator. */
3966 done_pipe(&ctx, PIPE_SEQ);
3967 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
3969 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
3974 dest.o_assignment = MAYBE_ASSIGNMENT;
3976 /* note: if (is_ifs) continue;
3977 * will still trigger for us */
3981 /* "cmd}" or "cmd }..." without semicolon or &:
3982 * } is an ordinary char in this case, even inside { cmd; }
3983 * Pathological example: { ""}; } should exec "}" cmd
3986 if (!IS_NULL_CMD(ctx.command) /* cmd } */
3987 || dest.length != 0 /* word} */
3988 || dest.has_quoted_part /* ""} */
3992 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
3993 goto skip_end_trigger;
3994 /* else: } does terminate a group */
3997 if (end_trigger && end_trigger == ch
3998 && (ch != ';' || heredoc_cnt == 0)
3999 #if ENABLE_HUSH_CASE
4001 || ctx.ctx_res_w != RES_MATCH
4002 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4007 /* This is technically valid:
4008 * { cat <<HERE; }; echo Ok
4012 * but we don't support this.
4013 * We require heredoc to be in enclosing {}/(),
4016 syntax_error_unterm_str("here document");
4019 if (done_word(&dest, &ctx)) {
4022 done_pipe(&ctx, PIPE_SEQ);
4023 dest.o_assignment = MAYBE_ASSIGNMENT;
4024 /* Do we sit outside of any if's, loops or case's? */
4026 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4030 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4032 *pstring = ctx.as_string.data;
4034 o_free_unsafe(&ctx.as_string);
4037 debug_printf_parse("parse_stream return %p: "
4038 "end_trigger char found\n",
4040 return ctx.list_head;
4047 /* Catch <, > before deciding whether this word is
4048 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4051 redir_fd = redirect_opt_num(&dest);
4052 if (done_word(&dest, &ctx)) {
4055 redir_style = REDIRECT_OVERWRITE;
4057 redir_style = REDIRECT_APPEND;
4058 ch = i_getch(input);
4059 nommu_addchr(&ctx.as_string, ch);
4062 else if (next == '(') {
4063 syntax_error(">(process) not supported");
4067 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4069 continue; /* back to top of while (1) */
4071 redir_fd = redirect_opt_num(&dest);
4072 if (done_word(&dest, &ctx)) {
4075 redir_style = REDIRECT_INPUT;
4077 redir_style = REDIRECT_HEREDOC;
4079 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4080 ch = i_getch(input);
4081 nommu_addchr(&ctx.as_string, ch);
4082 } else if (next == '>') {
4083 redir_style = REDIRECT_IO;
4084 ch = i_getch(input);
4085 nommu_addchr(&ctx.as_string, ch);
4088 else if (next == '(') {
4089 syntax_error("<(process) not supported");
4093 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4095 continue; /* back to top of while (1) */
4098 if (dest.o_assignment == MAYBE_ASSIGNMENT
4099 /* check that we are not in word in "a=1 2>word b=1": */
4100 && !ctx.pending_redirect
4102 /* ch is a special char and thus this word
4103 * cannot be an assignment */
4104 dest.o_assignment = NOT_ASSIGNMENT;
4107 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4111 if (dest.length == 0) {
4114 if (ch == EOF || ch == '\n')
4117 /* note: we do not add it to &ctx.as_string */
4119 nommu_addchr(&ctx.as_string, '\n');
4121 o_addQchr(&dest, ch);
4126 syntax_error("\\<eof>");
4129 ch = i_getch(input);
4131 o_addchr(&dest, '\\');
4132 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4133 o_addchr(&dest, ch);
4134 nommu_addchr(&ctx.as_string, ch);
4135 /* Example: echo Hello \2>file
4136 * we need to know that word 2 is quoted */
4137 dest.has_quoted_part = 1;
4141 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
4142 ctx.as_string.data[--ctx.as_string.length] = '\0';
4147 if (parse_dollar(&ctx.as_string, &dest, input) != 0) {
4148 debug_printf_parse("parse_stream parse error: "
4149 "parse_dollar returned non-0\n");
4154 dest.has_quoted_part = 1;
4156 ch = i_getch(input);
4158 syntax_error_unterm_ch('\'');
4159 /*xfunc_die(); - redundant */
4161 nommu_addchr(&ctx.as_string, ch);
4164 o_addqchr(&dest, ch);
4168 dest.has_quoted_part = 1;
4169 is_in_dquote ^= 1; /* invert */
4170 if (dest.o_assignment == NOT_ASSIGNMENT)
4173 #if ENABLE_HUSH_TICK
4177 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4178 o_addchr(&dest, '`');
4180 add_till_backquote(&dest, input);
4182 o_addstr(&ctx.as_string, dest.data + pos);
4183 o_addchr(&ctx.as_string, '`');
4185 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4186 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4191 #if ENABLE_HUSH_CASE
4194 if (done_word(&dest, &ctx)) {
4197 done_pipe(&ctx, PIPE_SEQ);
4198 #if ENABLE_HUSH_CASE
4199 /* Eat multiple semicolons, detect
4200 * whether it means something special */
4205 ch = i_getch(input);
4206 nommu_addchr(&ctx.as_string, ch);
4207 if (ctx.ctx_res_w == RES_CASE_BODY) {
4208 ctx.ctx_dsemicolon = 1;
4209 ctx.ctx_res_w = RES_MATCH;
4215 /* We just finished a cmd. New one may start
4216 * with an assignment */
4217 dest.o_assignment = MAYBE_ASSIGNMENT;
4220 if (done_word(&dest, &ctx)) {
4224 ch = i_getch(input);
4225 nommu_addchr(&ctx.as_string, ch);
4226 done_pipe(&ctx, PIPE_AND);
4228 done_pipe(&ctx, PIPE_BG);
4232 if (done_word(&dest, &ctx)) {
4235 #if ENABLE_HUSH_CASE
4236 if (ctx.ctx_res_w == RES_MATCH)
4237 break; /* we are in case's "word | word)" */
4239 if (next == '|') { /* || */
4240 ch = i_getch(input);
4241 nommu_addchr(&ctx.as_string, ch);
4242 done_pipe(&ctx, PIPE_OR);
4244 /* we could pick up a file descriptor choice here
4245 * with redirect_opt_num(), but bash doesn't do it.
4246 * "echo foo 2| cat" yields "foo 2". */
4249 o_reset_to_empty_unquoted(&ctx.as_string);
4254 #if ENABLE_HUSH_CASE
4255 /* "case... in [(]word)..." - skip '(' */
4256 if (ctx.ctx_res_w == RES_MATCH
4257 && ctx.command->argv == NULL /* not (word|(... */
4258 && dest.length == 0 /* not word(... */
4259 && dest.has_quoted_part == 0 /* not ""(... */
4265 if (parse_group(&dest, &ctx, input, ch) != 0) {
4270 #if ENABLE_HUSH_CASE
4271 if (ctx.ctx_res_w == RES_MATCH)
4275 /* proper use of this character is caught by end_trigger:
4276 * if we see {, we call parse_group(..., end_trigger='}')
4277 * and it will match } earlier (not here). */
4278 syntax_error_unexpected_ch(ch);
4282 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4288 struct parse_context *pctx;
4289 IF_HAS_KEYWORDS(struct parse_context *p2;)
4291 /* Clean up allocated tree.
4292 * Sample for finding leaks on syntax error recovery path.
4293 * Run it from interactive shell, watch pmap `pidof hush`.
4294 * while if false; then false; fi; do break; fi
4295 * Samples to catch leaks at execution:
4296 * while if (true | {true;}); then echo ok; fi; do break; done
4297 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4301 /* Update pipe/command counts,
4302 * otherwise freeing may miss some */
4303 done_pipe(pctx, PIPE_SEQ);
4304 debug_printf_clean("freeing list %p from ctx %p\n",
4305 pctx->list_head, pctx);
4306 debug_print_tree(pctx->list_head, 0);
4307 free_pipe_list(pctx->list_head);
4308 debug_printf_clean("freed list %p\n", pctx->list_head);
4310 o_free_unsafe(&pctx->as_string);
4312 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4316 IF_HAS_KEYWORDS(pctx = p2;)
4317 } while (HAS_KEYWORDS && pctx);
4318 /* Free text, clear all dest fields */
4320 /* If we are not in top-level parse, we return,
4321 * our caller will propagate error.
4323 if (end_trigger != ';') {
4331 /* Discard cached input, force prompt */
4333 IF_HUSH_INTERACTIVE(input->promptme = 1;)
4339 /*** Execution routines ***/
4341 /* Expansion can recurse, need forward decls: */
4342 static char *expand_string_to_string(const char *str);
4343 static int process_command_subs(o_string *dest, const char *s);
4345 /* expand_strvec_to_strvec() takes a list of strings, expands
4346 * all variable references within and returns a pointer to
4347 * a list of expanded strings, possibly with larger number
4348 * of strings. (Think VAR="a b"; echo $VAR).
4349 * This new list is allocated as a single malloc block.
4350 * NULL-terminated list of char* pointers is at the beginning of it,
4351 * followed by strings themself.
4352 * Caller can deallocate entire list by single free(list). */
4354 /* Store given string, finalizing the word and starting new one whenever
4355 * we encounter IFS char(s). This is used for expanding variable values.
4356 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
4357 static int expand_on_ifs(o_string *output, int n, const char *str)
4360 int word_len = strcspn(str, G.ifs);
4362 if (output->o_escape)
4363 o_addqblock(output, str, word_len);
4364 else if (!output->o_glob)
4365 o_addblock(output, str, word_len);
4366 else /* if (!escape && glob) */ {
4367 /* Protect backslashes against globbing up :)
4368 * Example: "v='\*'; echo b$v"
4370 o_addblock_duplicate_backslash(output, str, word_len);
4371 /*/ Why can't we do it easier? */
4372 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4373 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4377 if (!*str) /* EOL - do not finalize word */
4379 o_addchr(output, '\0');
4380 debug_print_list("expand_on_ifs", output, n);
4381 n = o_save_ptr(output, n);
4382 str += strspn(str, G.ifs); /* skip ifs chars */
4384 debug_print_list("expand_on_ifs[1]", output, n);
4388 /* Helper to expand $((...)) and heredoc body. These act as if
4389 * they are in double quotes, with the exception that they are not :).
4390 * Just the rules are similar: "expand only $var and `cmd`"
4392 * Returns malloced string.
4393 * As an optimization, we return NULL if expansion is not needed.
4395 static char *expand_pseudo_dquoted(const char *str)
4398 struct in_str input;
4399 o_string dest = NULL_O_STRING;
4401 if (!strchr(str, '$')
4402 && !strchr(str, '\\')
4403 #if ENABLE_HUSH_TICK
4404 && !strchr(str, '`')
4410 /* We need to expand. Example:
4411 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4413 setup_string_in_str(&input, str);
4414 parse_stream_dquoted(NULL, &dest, &input, EOF);
4415 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4416 exp_str = expand_string_to_string(dest.data);
4417 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4418 o_free_unsafe(&dest);
4422 #if ENABLE_SH_MATH_SUPPORT
4423 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
4425 arith_eval_hooks_t hooks;
4429 hooks.lookupvar = get_local_var_value;
4430 hooks.setvar = set_local_var_from_halves;
4431 //hooks.endofname = endofname;
4432 exp_str = expand_pseudo_dquoted(arg);
4433 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
4439 #if ENABLE_HUSH_BASH_COMPAT
4440 /* ${var/[/]pattern[/repl]} helpers */
4441 static char *strstr_pattern(char *val, const char *pattern, int *size)
4444 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4445 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4452 /* Optimization: if "*pat" did not match the start of "string",
4453 * we know that "tring", "ring" etc will not match too:
4455 if (pattern[0] == '*')
4460 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4462 char *result = NULL;
4463 unsigned res_len = 0;
4464 unsigned repl_len = strlen(repl);
4468 char *s = strstr_pattern(val, pattern, &size);
4472 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4473 memcpy(result + res_len, val, s - val);
4475 strcpy(result + res_len, repl);
4476 res_len += repl_len;
4477 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4483 if (val[0] && result) {
4484 result = xrealloc(result, res_len + strlen(val) + 1);
4485 strcpy(result + res_len, val);
4486 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4488 debug_printf_varexp("result:'%s'\n", result);
4494 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4496 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp, char first_ch)
4498 const char *val = NULL;
4499 char *to_be_freed = NULL;
4504 char exp_save = exp_save; /* for compiler */
4505 char *exp_saveptr; /* points to expansion operator */
4506 char *exp_word = exp_word; /* for compiler */
4510 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4511 first_char = arg[0] = first_ch & 0x7f;
4514 if (first_char == '#' && arg[1] && !exp_saveptr) {
4515 /* handle length expansion ${#var} */
4519 /* maybe handle parameter expansion */
4520 if (exp_saveptr /* if 2nd char is one of expansion operators */
4521 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4523 /* ${?:0}, ${#[:]%0} etc */
4524 exp_saveptr = var + 1;
4526 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4527 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4529 exp_op = exp_save = *exp_saveptr;
4531 exp_word = exp_saveptr + 1;
4532 if (exp_op == ':') {
4533 exp_op = *exp_word++;
4534 if (ENABLE_HUSH_BASH_COMPAT
4535 && (exp_op == '\0' || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4537 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4542 *exp_saveptr = '\0';
4543 } /* else: it's not an expansion op, but bare ${var} */
4546 /* lookup the variable in question */
4547 if (isdigit(var[0])) {
4548 /* parse_dollar() should have vetted var for us */
4549 int n = xatoi_positive(var);
4550 if (n < G.global_argc)
4551 val = G.global_argv[n];
4552 /* else val remains NULL: $N with too big N */
4556 val = utoa(G.root_pid);
4558 case '!': /* bg pid */
4559 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
4561 case '?': /* exitcode */
4562 val = utoa(G.last_exitcode);
4564 case '#': /* argc */
4565 val = utoa(G.global_argc ? G.global_argc-1 : 0);
4568 val = get_local_var_value(var);
4572 /* Handle any expansions */
4573 if (exp_op == 'L') {
4574 debug_printf_expand("expand: length(%s)=", val);
4575 val = utoa(val ? strlen(val) : 0);
4576 debug_printf_expand("%s\n", val);
4577 } else if (exp_op) {
4578 if (exp_op == '%' || exp_op == '#') {
4579 /* Standard-mandated substring removal ops:
4580 * ${parameter%word} - remove smallest suffix pattern
4581 * ${parameter%%word} - remove largest suffix pattern
4582 * ${parameter#word} - remove smallest prefix pattern
4583 * ${parameter##word} - remove largest prefix pattern
4585 * Word is expanded to produce a glob pattern.
4586 * Then var's value is matched to it and matching part removed.
4588 if (val && val[0]) {
4591 unsigned scan_flags = pick_scan(exp_op, *exp_word);
4592 if (exp_op == *exp_word) /* ## or %% */
4594 //TODO: avoid xstrdup unless needed
4595 // (see HACK ALERT below for an example)
4596 val = to_be_freed = xstrdup(val);
4597 //TODO: fix expansion rules:
4598 exp_exp_word = expand_pseudo_dquoted(exp_word);
4600 exp_word = exp_exp_word;
4601 loc = scan_and_match(to_be_freed, exp_word, scan_flags);
4602 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
4603 // exp_op, to_be_freed, exp_word, loc);
4605 if (loc) { /* match was found */
4606 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
4613 #if ENABLE_HUSH_BASH_COMPAT
4614 else if (exp_op == '/' || exp_op == '\\') {
4615 /* It's ${var/[/]pattern[/repl]} thing.
4616 * Note that in encoded form it has TWO parts:
4617 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4619 /* Empty variable always gives nothing: */
4620 // "v=''; echo ${v/*/w}" prints "", not "w"
4621 if (val && val[0]) {
4622 /* It's ${var/[/]pattern[/repl]} thing */
4624 * Pattern is taken literally, while
4625 * repl should be de-backslased and globbed
4626 * by the usual expansion rules:
4628 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
4629 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
4630 * v='a bz'; echo ${v/a*z/a*z} prints "az"
4631 * v='a bz'; echo ${v/a*z/\z} prints "z"
4632 * (note that a*z _pattern_ is never globbed!)
4634 //TODO: fix expansion rules:
4635 char *pattern, *repl, *t;
4636 pattern = expand_pseudo_dquoted(exp_word);
4638 pattern = xstrdup(exp_word);
4639 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
4640 *p++ = SPECIAL_VAR_SYMBOL;
4642 p = strchr(p, SPECIAL_VAR_SYMBOL);
4644 repl = expand_pseudo_dquoted(exp_word);
4645 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
4646 /* HACK ALERT. We depend here on the fact that
4647 * G.global_argv and results of utoa and get_local_var_value
4648 * are actually in writable memory:
4649 * replace_pattern momentarily stores NULs there. */
4651 to_be_freed = replace_pattern(t,
4653 (repl ? repl : exp_word),
4655 if (to_be_freed) /* at least one replace happened */
4662 else if (exp_op == ':') {
4663 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
4664 /* It's ${var:N[:M]} bashism.
4665 * Note that in encoded form it has TWO parts:
4666 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
4671 beg = expand_and_evaluate_arith(exp_word, &errcode);
4672 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
4673 *p++ = SPECIAL_VAR_SYMBOL;
4675 p = strchr(p, SPECIAL_VAR_SYMBOL);
4677 len = expand_and_evaluate_arith(exp_word, &errcode);
4678 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
4680 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
4681 if (beg < 0) /* bash compat */
4683 debug_printf_varexp("from val:'%s'\n", val);
4684 if (len == 0 || !val || beg >= strlen(val))
4687 /* Paranoia. What if user entered 9999999999999
4688 * which fits in arith_t but not int? */
4691 val = to_be_freed = xstrndup(val + beg, len);
4693 debug_printf_varexp("val:'%s'\n", val);
4697 die_if_script("malformed ${%s:...}", var);
4700 } else { /* one of "-=+?" */
4701 /* Standard-mandated substitution ops:
4702 * ${var?word} - indicate error if unset
4703 * If var is unset, word (or a message indicating it is unset
4704 * if word is null) is written to standard error
4705 * and the shell exits with a non-zero exit status.
4706 * Otherwise, the value of var is substituted.
4707 * ${var-word} - use default value
4708 * If var is unset, word is substituted.
4709 * ${var=word} - assign and use default value
4710 * If var is unset, word is assigned to var.
4711 * In all cases, final value of var is substituted.
4712 * ${var+word} - use alternative value
4713 * If var is unset, null is substituted.
4714 * Otherwise, word is substituted.
4716 * Word is subjected to tilde expansion, parameter expansion,
4717 * command substitution, and arithmetic expansion.
4718 * If word is not needed, it is not expanded.
4720 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
4721 * but also treat null var as if it is unset.
4723 int use_word = (!val || ((exp_save == ':') && !val[0]));
4725 use_word = !use_word;
4726 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
4727 (exp_save == ':') ? "true" : "false", use_word);
4729 to_be_freed = expand_pseudo_dquoted(exp_word);
4731 exp_word = to_be_freed;
4732 if (exp_op == '?') {
4733 /* mimic bash message */
4734 die_if_script("%s: %s",
4736 exp_word[0] ? exp_word : "parameter null or not set"
4738 //TODO: how interactive bash aborts expansion mid-command?
4743 if (exp_op == '=') {
4744 /* ${var=[word]} or ${var:=[word]} */
4745 if (isdigit(var[0]) || var[0] == '#') {
4746 /* mimic bash message */
4747 die_if_script("$%s: cannot assign in this way", var);
4750 char *new_var = xasprintf("%s=%s", var, val);
4751 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4755 } /* one of "-=+?" */
4757 *exp_saveptr = exp_save;
4763 *to_be_freed_pp = to_be_freed;
4767 /* Expand all variable references in given string, adding words to list[]
4768 * at n, n+1,... positions. Return updated n (so that list[n] is next one
4769 * to be filled). This routine is extremely tricky: has to deal with
4770 * variables/parameters with whitespace, $* and $@, and constructs like
4771 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
4772 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
4774 /* or_mask is either 0 (normal case) or 0x80 -
4775 * expansion of right-hand side of assignment == 1-element expand.
4776 * It will also do no globbing, and thus we must not backslash-quote!
4783 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
4784 debug_print_list("expand_vars_to_list", output, n);
4785 n = o_save_ptr(output, n);
4786 debug_print_list("expand_vars_to_list[0]", output, n);
4788 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
4790 char *to_be_freed = NULL;
4791 const char *val = NULL;
4792 #if ENABLE_HUSH_TICK
4793 o_string subst_result = NULL_O_STRING;
4795 #if ENABLE_SH_MATH_SUPPORT
4796 char arith_buf[sizeof(arith_t)*3 + 2];
4798 o_addblock(output, arg, p - arg);
4799 debug_print_list("expand_vars_to_list[1]", output, n);
4801 p = strchr(p, SPECIAL_VAR_SYMBOL);
4803 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
4804 /* "$@" is special. Even if quoted, it can still
4805 * expand to nothing (not even an empty string) */
4806 if ((first_ch & 0x7f) != '@')
4807 ored_ch |= first_ch;
4809 switch (first_ch & 0x7f) {
4810 /* Highest bit in first_ch indicates that var is double-quoted */
4814 if (!G.global_argv[1])
4817 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
4818 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
4819 smallint sv = output->o_escape;
4820 /* unquoted var's contents should be globbed, so don't escape */
4821 output->o_escape = 0;
4822 while (G.global_argv[i]) {
4823 n = expand_on_ifs(output, n, G.global_argv[i]);
4824 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
4825 if (G.global_argv[i++][0] && G.global_argv[i]) {
4826 /* this argv[] is not empty and not last:
4827 * put terminating NUL, start new word */
4828 o_addchr(output, '\0');
4829 debug_print_list("expand_vars_to_list[2]", output, n);
4830 n = o_save_ptr(output, n);
4831 debug_print_list("expand_vars_to_list[3]", output, n);
4834 output->o_escape = sv;
4836 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
4837 * and in this case should treat it like '$*' - see 'else...' below */
4838 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
4840 o_addQstr(output, G.global_argv[i]);
4841 if (++i >= G.global_argc)
4843 o_addchr(output, '\0');
4844 debug_print_list("expand_vars_to_list[4]", output, n);
4845 n = o_save_ptr(output, n);
4847 } else { /* quoted $*: add as one word */
4849 o_addQstr(output, G.global_argv[i]);
4850 if (!G.global_argv[++i])
4853 o_addchr(output, G.ifs[0]);
4858 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
4859 /* "Empty variable", used to make "" etc to not disappear */
4863 #if ENABLE_HUSH_TICK
4864 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
4867 /* Can't just stuff it into output o_string,
4868 * expanded result may need to be globbed
4869 * and $IFS-splitted */
4870 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
4871 G.last_exitcode = process_command_subs(&subst_result, arg);
4872 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
4873 val = subst_result.data;
4876 #if ENABLE_SH_MATH_SUPPORT
4877 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
4881 arg++; /* skip '+' */
4882 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
4883 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
4884 res = expand_and_evaluate_arith(arg, &errcode);
4887 const char *msg = "error in arithmetic";
4890 msg = "exponent less than 0";
4893 msg = "divide by 0";
4896 msg = "expression recursion loop detected";
4901 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
4902 sprintf(arith_buf, arith_t_fmt, res);
4908 val = expand_one_var(&to_be_freed, arg, &p, first_ch);
4909 IF_HUSH_TICK(store_val:)
4910 if (!(first_ch & 0x80)) { /* unquoted $VAR */
4911 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
4912 if (val && val[0]) {
4913 /* unquoted var's contents should be globbed, so don't escape */
4914 smallint sv = output->o_escape;
4915 output->o_escape = 0;
4916 n = expand_on_ifs(output, n, val);
4918 output->o_escape = sv;
4920 } else { /* quoted $VAR, val will be appended below */
4921 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
4925 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
4927 if (val && val[0]) {
4928 o_addQstr(output, val);
4931 /* Do the check to avoid writing to a const string */
4932 if (*p != SPECIAL_VAR_SYMBOL)
4933 *p = SPECIAL_VAR_SYMBOL;
4935 #if ENABLE_HUSH_TICK
4936 o_free(&subst_result);
4939 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
4942 debug_print_list("expand_vars_to_list[a]", output, n);
4943 /* this part is literal, and it was already pre-quoted
4944 * if needed (much earlier), do not use o_addQstr here! */
4945 o_addstr_with_NUL(output, arg);
4946 debug_print_list("expand_vars_to_list[b]", output, n);
4947 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
4948 && !(ored_ch & 0x80) /* and all vars were not quoted. */
4951 /* allow to reuse list[n] later without re-growth */
4952 output->has_empty_slot = 1;
4954 o_addchr(output, '\0');
4961 EXPVAR_FLAG_GLOB = 0x200,
4962 EXPVAR_FLAG_ESCAPE_VARS = 0x100,
4963 EXPVAR_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
4965 static char **expand_variables(char **argv, unsigned or_mask)
4969 o_string output = NULL_O_STRING;
4971 /* protect against globbing for "$var"? */
4972 /* (unquoted $var will temporarily switch it off) */
4973 output.o_escape = 1 & (or_mask / EXPVAR_FLAG_ESCAPE_VARS);
4974 output.o_glob = 1 & (or_mask / EXPVAR_FLAG_GLOB);
4978 n = expand_vars_to_list(&output, n, *argv, (unsigned char)or_mask);
4981 debug_print_list("expand_variables", &output, n);
4983 /* output.data (malloced in one block) gets returned in "list" */
4984 list = o_finalize_list(&output, n);
4985 debug_print_strings("expand_variables[1]", list);
4989 static char **expand_strvec_to_strvec(char **argv)
4991 return expand_variables(argv, EXPVAR_FLAG_GLOB | EXPVAR_FLAG_ESCAPE_VARS);
4994 #if ENABLE_HUSH_BASH_COMPAT
4995 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
4997 return expand_variables(argv, EXPVAR_FLAG_SINGLEWORD);
5001 /* Used for expansion of right hand of assignments */
5002 /* NB: should NOT do globbing!
5003 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*" */
5004 static char *expand_string_to_string(const char *str)
5006 char *argv[2], **list;
5008 /* This is generally an optimization, but it also
5009 * handles "", which otherwise trips over !list[0] check below.
5010 * (is this ever happens that we actually get str="" here?)
5012 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5013 //TODO: Can use on strings with \ too, just unbackslash() them?
5014 debug_printf_expand("string_to_string(fast)='%s'\n", str);
5015 return xstrdup(str);
5018 argv[0] = (char*)str;
5020 list = expand_variables(argv, EXPVAR_FLAG_ESCAPE_VARS | EXPVAR_FLAG_SINGLEWORD);
5022 if (!list[0] || list[1])
5023 bb_error_msg_and_die("BUG in varexp2");
5024 /* actually, just move string 2*sizeof(char*) bytes back */
5025 overlapping_strcpy((char*)list, list[0]);
5026 unbackslash((char*)list);
5027 debug_printf_expand("string_to_string='%s'\n", (char*)list);
5031 /* Used for "eval" builtin */
5032 static char* expand_strvec_to_string(char **argv)
5036 list = expand_variables(argv, EXPVAR_FLAG_SINGLEWORD);
5037 /* Convert all NULs to spaces */
5042 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5043 bb_error_msg_and_die("BUG in varexp3");
5044 /* bash uses ' ' regardless of $IFS contents */
5049 overlapping_strcpy((char*)list, list[0]);
5050 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5054 static char **expand_assignments(char **argv, int count)
5059 G.expanded_assignments = p = NULL;
5060 /* Expand assignments into one string each */
5061 for (i = 0; i < count; i++) {
5062 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i]));
5064 G.expanded_assignments = NULL;
5071 void re_execute_shell(char ***to_free, const char *s,
5072 char *g_argv0, char **g_argv,
5073 char **builtin_argv) NORETURN;
5075 static void reset_traps_to_defaults(void)
5077 /* This function is always called in a child shell
5078 * after fork (not vfork, NOMMU doesn't use this function).
5083 /* Child shells are not interactive.
5084 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5085 * Testcase: (while :; do :; done) + ^Z should background.
5086 * Same goes for SIGTERM, SIGHUP, SIGINT.
5088 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
5089 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
5091 /* Switching off SPECIAL_INTERACTIVE_SIGS.
5092 * Stupid. It can be done with *single* &= op, but we can't use
5093 * the fact that G.blocked_set is implemented as a bitmask
5095 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
5099 /* Careful. Only if no trap or trap is not "" */
5100 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
5101 sigdelset(&G.blocked_set, sig);
5108 /* Our homegrown sig mask is saner to work with :) */
5109 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5111 /* Resetting all traps to default except empty ones */
5112 mask = G.non_DFL_mask;
5113 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
5114 if (!G.traps[sig] || !G.traps[sig][0])
5117 G.traps[sig] = NULL;
5118 /* There is no signal for 0 (EXIT) */
5121 /* There was a trap handler, we just removed it.
5122 * But if sig still has non-DFL handling,
5123 * we should not unblock the sig. */
5126 sigdelset(&G.blocked_set, sig);
5128 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5133 static void re_execute_shell(char ***to_free, const char *s,
5134 char *g_argv0, char **g_argv,
5135 char **builtin_argv) NORETURN;
5136 static void re_execute_shell(char ***to_free, const char *s,
5137 char *g_argv0, char **g_argv,
5138 char **builtin_argv)
5140 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5141 /* delims + 2 * (number of bytes in printed hex numbers) */
5142 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5143 char *heredoc_argv[4];
5144 struct variable *cur;
5145 # if ENABLE_HUSH_FUNCTIONS
5146 struct function *funcp;
5150 unsigned long long empty_trap_mask;
5152 if (!g_argv0) { /* heredoc */
5153 argv = heredoc_argv;
5154 argv[0] = (char *) G.argv0_for_re_execing;
5155 argv[1] = (char *) "-<";
5156 argv[2] = (char *) s;
5158 pp = &argv[3]; /* used as pointer to empty environment */
5164 if (pp) while (*pp++)
5167 empty_trap_mask = 0;
5170 for (sig = 1; sig < NSIG; sig++) {
5171 if (G.traps[sig] && !G.traps[sig][0])
5172 empty_trap_mask |= 1LL << sig;
5176 sprintf(param_buf, NOMMU_HACK_FMT
5177 , (unsigned) G.root_pid
5178 , (unsigned) G.root_ppid
5179 , (unsigned) G.last_bg_pid
5180 , (unsigned) G.last_exitcode
5183 IF_HUSH_LOOPS(, G.depth_of_loop)
5185 # undef NOMMU_HACK_FMT
5186 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5187 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5190 for (cur = G.top_var; cur; cur = cur->next) {
5191 if (!cur->flg_export || cur->flg_read_only)
5194 # if ENABLE_HUSH_FUNCTIONS
5195 for (funcp = G.top_func; funcp; funcp = funcp->next)
5201 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5202 *pp++ = (char *) G.argv0_for_re_execing;
5204 for (cur = G.top_var; cur; cur = cur->next) {
5205 if (strcmp(cur->varstr, hush_version_str) == 0)
5207 if (cur->flg_read_only) {
5208 *pp++ = (char *) "-R";
5209 *pp++ = cur->varstr;
5210 } else if (!cur->flg_export) {
5211 *pp++ = (char *) "-V";
5212 *pp++ = cur->varstr;
5215 # if ENABLE_HUSH_FUNCTIONS
5216 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5217 *pp++ = (char *) "-F";
5218 *pp++ = funcp->name;
5219 *pp++ = funcp->body_as_string;
5222 /* We can pass activated traps here. Say, -Tnn:trap_string
5224 * However, POSIX says that subshells reset signals with traps
5226 * I tested bash-3.2 and it not only does that with true subshells
5227 * of the form ( list ), but with any forked children shells.
5228 * I set trap "echo W" WINCH; and then tried:
5230 * { echo 1; sleep 20; echo 2; } &
5231 * while true; do echo 1; sleep 20; echo 2; break; done &
5232 * true | { echo 1; sleep 20; echo 2; } | cat
5234 * In all these cases sending SIGWINCH to the child shell
5235 * did not run the trap. If I add trap "echo V" WINCH;
5236 * _inside_ group (just before echo 1), it works.
5238 * I conclude it means we don't need to pass active traps here.
5239 * Even if we would use signal handlers instead of signal masking
5240 * in order to implement trap handling,
5241 * exec syscall below resets signals to SIG_DFL for us.
5243 *pp++ = (char *) "-c";
5246 while (*++builtin_argv)
5247 *pp++ = *builtin_argv;
5248 *pp++ = (char *) "";
5253 /* *pp = NULL; - is already there */
5257 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5258 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5259 execve(bb_busybox_exec_path, argv, pp);
5260 /* Fallback. Useful for init=/bin/hush usage etc */
5261 if (argv[0][0] == '/')
5262 execve(argv[0], argv, pp);
5263 xfunc_error_retval = 127;
5264 bb_error_msg_and_die("can't re-execute the shell");
5266 #endif /* !BB_MMU */
5269 static int run_and_free_list(struct pipe *pi);
5271 /* Executing from string: eval, sh -c '...'
5272 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5273 * end_trigger controls how often we stop parsing
5274 * NUL: parse all, execute, return
5275 * ';': parse till ';' or newline, execute, repeat till EOF
5277 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5279 /* Why we need empty flag?
5280 * An obscure corner case "false; ``; echo $?":
5281 * empty command in `` should still set $? to 0.
5282 * But we can't just set $? to 0 at the start,
5283 * this breaks "false; echo `echo $?`" case.
5287 struct pipe *pipe_list;
5289 pipe_list = parse_stream(NULL, inp, end_trigger);
5290 if (!pipe_list) { /* EOF */
5292 G.last_exitcode = 0;
5295 debug_print_tree(pipe_list, 0);
5296 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5297 run_and_free_list(pipe_list);
5302 static void parse_and_run_string(const char *s)
5304 struct in_str input;
5305 setup_string_in_str(&input, s);
5306 parse_and_run_stream(&input, '\0');
5309 static void parse_and_run_file(FILE *f)
5311 struct in_str input;
5312 setup_file_in_str(&input, f);
5313 parse_and_run_stream(&input, ';');
5316 #if ENABLE_HUSH_TICK
5317 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5322 char **to_free = NULL;
5326 pid = BB_MMU ? xfork() : xvfork();
5327 if (pid == 0) { /* child */
5328 disable_restore_tty_pgrp_on_exit();
5329 /* Process substitution is not considered to be usual
5330 * 'command execution'.
5331 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5338 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5339 close(channel[0]); /* NB: close _first_, then move fd! */
5340 xmove_fd(channel[1], 1);
5341 /* Prevent it from trying to handle ctrl-z etc */
5342 IF_HUSH_JOB(G.run_list_level = 1;)
5343 /* Awful hack for `trap` or $(trap).
5345 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5346 * contains an example where "trap" is executed in a subshell:
5348 * save_traps=$(trap)
5350 * eval "$save_traps"
5352 * Standard does not say that "trap" in subshell shall print
5353 * parent shell's traps. It only says that its output
5354 * must have suitable form, but then, in the above example
5355 * (which is not supposed to be normative), it implies that.
5357 * bash (and probably other shell) does implement it
5358 * (traps are reset to defaults, but "trap" still shows them),
5359 * but as a result, "trap" logic is hopelessly messed up:
5362 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5363 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5364 * # true | trap <--- trap is in subshell - no output (ditto)
5365 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5366 * trap -- 'echo Ho' SIGWINCH
5367 * # echo `(trap)` <--- in subshell in subshell - output
5368 * trap -- 'echo Ho' SIGWINCH
5369 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5370 * trap -- 'echo Ho' SIGWINCH
5372 * The rules when to forget and when to not forget traps
5373 * get really complex and nonsensical.
5375 * Our solution: ONLY bare $(trap) or `trap` is special.
5377 s = skip_whitespace(s);
5378 if (strncmp(s, "trap", 4) == 0
5379 && skip_whitespace(s + 4)[0] == '\0'
5381 static const char *const argv[] = { NULL, NULL };
5382 builtin_trap((char**)argv);
5383 exit(0); /* not _exit() - we need to fflush */
5386 reset_traps_to_defaults();
5387 parse_and_run_string(s);
5388 _exit(G.last_exitcode);
5390 /* We re-execute after vfork on NOMMU. This makes this script safe:
5391 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5392 * huge=`cat BIG` # was blocking here forever
5395 re_execute_shell(&to_free,
5405 # if ENABLE_HUSH_FAST
5407 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5408 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5409 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5411 enable_restore_tty_pgrp_on_exit();
5416 close_on_exec_on(channel[0]);
5417 return xfdopen_for_read(channel[0]);
5420 /* Return code is exit status of the process that is run. */
5421 static int process_command_subs(o_string *dest, const char *s)
5424 struct in_str pipe_str;
5426 int status, ch, eol_cnt;
5428 fp = generate_stream_from_string(s, &pid);
5430 /* Now send results of command back into original context */
5431 setup_file_in_str(&pipe_str, fp);
5433 while ((ch = i_getch(&pipe_str)) != EOF) {
5439 o_addchr(dest, '\n');
5442 o_addQchr(dest, ch);
5445 debug_printf("done reading from `cmd` pipe, closing it\n");
5447 /* We need to extract exitcode. Test case
5448 * "true; echo `sleep 1; false` $?"
5450 safe_waitpid(pid, &status, 0);
5451 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5452 return WEXITSTATUS(status);
5454 #endif /* ENABLE_HUSH_TICK */
5457 static void setup_heredoc(struct redir_struct *redir)
5459 struct fd_pair pair;
5462 /* the _body_ of heredoc (misleading field name) */
5463 const char *heredoc = redir->rd_filename;
5470 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5471 expanded = expand_pseudo_dquoted(heredoc);
5475 len = strlen(heredoc);
5477 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5479 xmove_fd(pair.rd, redir->rd_fd);
5481 /* Try writing without forking. Newer kernels have
5482 * dynamically growing pipes. Must use non-blocking write! */
5485 written = write(pair.wr, heredoc, len);
5496 ndelay_off(pair.wr);
5498 /* Okay, pipe buffer was not big enough */
5499 /* Note: we must not create a stray child (bastard? :)
5500 * for the unsuspecting parent process. Child creates a grandchild
5501 * and exits before parent execs the process which consumes heredoc
5502 * (that exec happens after we return from this function) */
5509 disable_restore_tty_pgrp_on_exit();
5510 pid = BB_MMU ? xfork() : xvfork();
5514 close(redir->rd_fd); /* read side of the pipe */
5516 full_write(pair.wr, heredoc, len); /* may loop or block */
5519 /* Delegate blocking writes to another process */
5520 xmove_fd(pair.wr, STDOUT_FILENO);
5521 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
5525 #if ENABLE_HUSH_FAST
5527 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5529 enable_restore_tty_pgrp_on_exit();
5535 wait(NULL); /* wait till child has died */
5538 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
5539 * and stderr if they are redirected. */
5540 static int setup_redirects(struct command *prog, int squirrel[])
5543 struct redir_struct *redir;
5545 for (redir = prog->redirects; redir; redir = redir->next) {
5546 if (redir->rd_type == REDIRECT_HEREDOC2) {
5547 /* rd_fd<<HERE case */
5548 if (squirrel && redir->rd_fd < 3
5549 && squirrel[redir->rd_fd] < 0
5551 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5553 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
5555 debug_printf_parse("set heredoc '%s'\n",
5556 redir->rd_filename);
5557 setup_heredoc(redir);
5561 if (redir->rd_dup == REDIRFD_TO_FILE) {
5562 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
5564 if (redir->rd_filename == NULL) {
5565 /* Something went wrong in the parse.
5566 * Pretend it didn't happen */
5567 bb_error_msg("bug in redirect parse");
5570 mode = redir_table[redir->rd_type].mode;
5571 p = expand_string_to_string(redir->rd_filename);
5572 openfd = open_or_warn(p, mode);
5575 /* this could get lost if stderr has been redirected, but
5576 * bash and ash both lose it as well (though zsh doesn't!) */
5577 //what the above comment tries to say?
5581 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
5582 openfd = redir->rd_dup;
5585 if (openfd != redir->rd_fd) {
5586 if (squirrel && redir->rd_fd < 3
5587 && squirrel[redir->rd_fd] < 0
5589 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5591 if (openfd == REDIRFD_CLOSE) {
5592 /* "n>-" means "close me" */
5593 close(redir->rd_fd);
5595 xdup2(openfd, redir->rd_fd);
5596 if (redir->rd_dup == REDIRFD_TO_FILE)
5604 static void restore_redirects(int squirrel[])
5607 for (i = 0; i < 3; i++) {
5610 /* We simply die on error */
5616 static char *find_in_path(const char *arg)
5619 const char *PATH = get_local_var_value("PATH");
5625 const char *end = strchrnul(PATH, ':');
5626 int sz = end - PATH; /* must be int! */
5630 ret = xasprintf("%.*s/%s", sz, PATH, arg);
5632 /* We have xxx::yyyy in $PATH,
5633 * it means "use current dir" */
5636 if (access(ret, F_OK) == 0)
5649 static const struct built_in_command *find_builtin_helper(const char *name,
5650 const struct built_in_command *x,
5651 const struct built_in_command *end)
5654 if (strcmp(name, x->b_cmd) != 0) {
5658 debug_printf_exec("found builtin '%s'\n", name);
5663 static const struct built_in_command *find_builtin1(const char *name)
5665 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
5667 static const struct built_in_command *find_builtin(const char *name)
5669 const struct built_in_command *x = find_builtin1(name);
5672 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
5675 #if ENABLE_HUSH_FUNCTIONS
5676 static struct function **find_function_slot(const char *name)
5678 struct function **funcpp = &G.top_func;
5680 if (strcmp(name, (*funcpp)->name) == 0) {
5683 funcpp = &(*funcpp)->next;
5688 static const struct function *find_function(const char *name)
5690 const struct function *funcp = *find_function_slot(name);
5692 debug_printf_exec("found function '%s'\n", name);
5696 /* Note: takes ownership on name ptr */
5697 static struct function *new_function(char *name)
5699 struct function **funcpp = find_function_slot(name);
5700 struct function *funcp = *funcpp;
5702 if (funcp != NULL) {
5703 struct command *cmd = funcp->parent_cmd;
5704 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
5706 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
5708 /* Note: if !funcp->body, do not free body_as_string!
5709 * This is a special case of "-F name body" function:
5710 * body_as_string was not malloced! */
5712 free_pipe_list(funcp->body);
5714 free(funcp->body_as_string);
5718 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
5719 cmd->argv[0] = funcp->name;
5720 cmd->group = funcp->body;
5722 cmd->group_as_string = funcp->body_as_string;
5726 debug_printf_exec("remembering new function '%s'\n", name);
5727 funcp = *funcpp = xzalloc(sizeof(*funcp));
5728 /*funcp->next = NULL;*/
5735 static void unset_func(const char *name)
5737 struct function **funcpp = find_function_slot(name);
5738 struct function *funcp = *funcpp;
5740 if (funcp != NULL) {
5741 debug_printf_exec("freeing function '%s'\n", funcp->name);
5742 *funcpp = funcp->next;
5743 /* funcp is unlinked now, deleting it.
5744 * Note: if !funcp->body, the function was created by
5745 * "-F name body", do not free ->body_as_string
5746 * and ->name as they were not malloced. */
5748 free_pipe_list(funcp->body);
5751 free(funcp->body_as_string);
5759 #define exec_function(to_free, funcp, argv) \
5760 exec_function(funcp, argv)
5762 static void exec_function(char ***to_free,
5763 const struct function *funcp,
5764 char **argv) NORETURN;
5765 static void exec_function(char ***to_free,
5766 const struct function *funcp,
5772 argv[0] = G.global_argv[0];
5773 G.global_argv = argv;
5777 /* On MMU, funcp->body is always non-NULL */
5778 n = run_list(funcp->body);
5782 re_execute_shell(to_free,
5783 funcp->body_as_string,
5790 static int run_function(const struct function *funcp, char **argv)
5796 save_and_replace_G_args(&sv, argv);
5798 /* "we are in function, ok to use return" */
5799 sv_flg = G.flag_return_in_progress;
5800 G.flag_return_in_progress = -1;
5801 # if ENABLE_HUSH_LOCAL
5802 G.func_nest_level++;
5805 /* On MMU, funcp->body is always non-NULL */
5808 /* Function defined by -F */
5809 parse_and_run_string(funcp->body_as_string);
5810 rc = G.last_exitcode;
5814 rc = run_list(funcp->body);
5817 # if ENABLE_HUSH_LOCAL
5819 struct variable *var;
5820 struct variable **var_pp;
5822 var_pp = &G.top_var;
5823 while ((var = *var_pp) != NULL) {
5824 if (var->func_nest_level < G.func_nest_level) {
5825 var_pp = &var->next;
5829 if (var->flg_export)
5830 bb_unsetenv(var->varstr);
5831 /* Remove from global list */
5832 *var_pp = var->next;
5838 G.func_nest_level--;
5841 G.flag_return_in_progress = sv_flg;
5843 restore_G_args(&sv, argv);
5847 #endif /* ENABLE_HUSH_FUNCTIONS */
5851 #define exec_builtin(to_free, x, argv) \
5852 exec_builtin(x, argv)
5854 #define exec_builtin(to_free, x, argv) \
5855 exec_builtin(to_free, argv)
5857 static void exec_builtin(char ***to_free,
5858 const struct built_in_command *x,
5859 char **argv) NORETURN;
5860 static void exec_builtin(char ***to_free,
5861 const struct built_in_command *x,
5865 int rcode = x->b_function(argv);
5869 /* On NOMMU, we must never block!
5870 * Example: { sleep 99 | read line; } & echo Ok
5872 re_execute_shell(to_free,
5881 static void execvp_or_die(char **argv) NORETURN;
5882 static void execvp_or_die(char **argv)
5884 debug_printf_exec("execing '%s'\n", argv[0]);
5885 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5886 execvp(argv[0], argv);
5887 bb_perror_msg("can't execute '%s'", argv[0]);
5888 _exit(127); /* bash compat */
5891 #if ENABLE_HUSH_MODE_X
5892 static void dump_cmd_in_x_mode(char **argv)
5894 if (G_x_mode && argv) {
5895 /* We want to output the line in one write op */
5903 len += strlen(argv[n++]) + 1;
5909 p += sprintf(p, " %s", argv[n++]);
5917 # define dump_cmd_in_x_mode(argv) ((void)0)
5921 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
5922 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
5923 #define pseudo_exec(nommu_save, command, argv_expanded) \
5924 pseudo_exec(command, argv_expanded)
5927 /* Called after [v]fork() in run_pipe, or from builtin_exec.
5929 * Don't exit() here. If you don't exec, use _exit instead.
5930 * The at_exit handlers apparently confuse the calling process,
5931 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
5932 static void pseudo_exec_argv(nommu_save_t *nommu_save,
5933 char **argv, int assignment_cnt,
5934 char **argv_expanded) NORETURN;
5935 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
5936 char **argv, int assignment_cnt,
5937 char **argv_expanded)
5941 new_env = expand_assignments(argv, assignment_cnt);
5942 dump_cmd_in_x_mode(new_env);
5944 if (!argv[assignment_cnt]) {
5945 /* Case when we are here: ... | var=val | ...
5946 * (note that we do not exit early, i.e., do not optimize out
5947 * expand_assignments(): think about ... | var=`sleep 1` | ...
5949 free_strings(new_env);
5950 _exit(EXIT_SUCCESS);
5954 set_vars_and_save_old(new_env);
5955 free(new_env); /* optional */
5956 /* we can also destroy set_vars_and_save_old's return value,
5959 nommu_save->new_env = new_env;
5960 nommu_save->old_vars = set_vars_and_save_old(new_env);
5963 if (argv_expanded) {
5964 argv = argv_expanded;
5966 argv = expand_strvec_to_strvec(argv + assignment_cnt);
5968 nommu_save->argv = argv;
5971 dump_cmd_in_x_mode(argv);
5973 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
5974 if (strchr(argv[0], '/') != NULL)
5978 /* Check if the command matches any of the builtins.
5979 * Depending on context, this might be redundant. But it's
5980 * easier to waste a few CPU cycles than it is to figure out
5981 * if this is one of those cases.
5984 /* On NOMMU, it is more expensive to re-execute shell
5985 * just in order to run echo or test builtin.
5986 * It's better to skip it here and run corresponding
5987 * non-builtin later. */
5988 const struct built_in_command *x;
5989 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
5991 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
5994 #if ENABLE_HUSH_FUNCTIONS
5995 /* Check if the command matches any functions */
5997 const struct function *funcp = find_function(argv[0]);
5999 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6004 #if ENABLE_FEATURE_SH_STANDALONE
6005 /* Check if the command matches any busybox applets */
6007 int a = find_applet_by_name(argv[0]);
6009 # if BB_MMU /* see above why on NOMMU it is not allowed */
6010 if (APPLET_IS_NOEXEC(a)) {
6011 debug_printf_exec("running applet '%s'\n", argv[0]);
6012 run_applet_no_and_exit(a, argv);
6015 /* Re-exec ourselves */
6016 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6017 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6018 execv(bb_busybox_exec_path, argv);
6019 /* If they called chroot or otherwise made the binary no longer
6020 * executable, fall through */
6025 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6028 execvp_or_die(argv);
6031 /* Called after [v]fork() in run_pipe
6033 static void pseudo_exec(nommu_save_t *nommu_save,
6034 struct command *command,
6035 char **argv_expanded) NORETURN;
6036 static void pseudo_exec(nommu_save_t *nommu_save,
6037 struct command *command,
6038 char **argv_expanded)
6040 if (command->argv) {
6041 pseudo_exec_argv(nommu_save, command->argv,
6042 command->assignment_cnt, argv_expanded);
6045 if (command->group) {
6046 /* Cases when we are here:
6049 * ... | ( list ) | ...
6050 * ... | { list } | ...
6054 debug_printf_exec("pseudo_exec: run_list\n");
6055 reset_traps_to_defaults();
6056 rcode = run_list(command->group);
6057 /* OK to leak memory by not calling free_pipe_list,
6058 * since this process is about to exit */
6061 re_execute_shell(&nommu_save->argv_from_re_execing,
6062 command->group_as_string,
6069 /* Case when we are here: ... | >file */
6070 debug_printf_exec("pseudo_exec'ed null command\n");
6071 _exit(EXIT_SUCCESS);
6075 static const char *get_cmdtext(struct pipe *pi)
6081 /* This is subtle. ->cmdtext is created only on first backgrounding.
6082 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6083 * On subsequent bg argv is trashed, but we won't use it */
6086 argv = pi->cmds[0].argv;
6087 if (!argv || !argv[0]) {
6088 pi->cmdtext = xzalloc(1);
6094 len += strlen(*argv) + 1;
6098 argv = pi->cmds[0].argv;
6100 len = strlen(*argv);
6101 memcpy(p, *argv, len);
6109 static void insert_bg_job(struct pipe *pi)
6111 struct pipe *job, **jobp;
6114 /* Linear search for the ID of the job to use */
6116 for (job = G.job_list; job; job = job->next)
6117 if (job->jobid >= pi->jobid)
6118 pi->jobid = job->jobid + 1;
6120 /* Add job to the list of running jobs */
6122 while ((job = *jobp) != NULL)
6124 job = *jobp = xmalloc(sizeof(*job));
6126 *job = *pi; /* physical copy */
6128 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6129 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6130 for (i = 0; i < pi->num_cmds; i++) {
6131 job->cmds[i].pid = pi->cmds[i].pid;
6132 /* all other fields are not used and stay zero */
6134 job->cmdtext = xstrdup(get_cmdtext(pi));
6136 if (G_interactive_fd)
6137 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6138 G.last_jobid = job->jobid;
6141 static void remove_bg_job(struct pipe *pi)
6143 struct pipe *prev_pipe;
6145 if (pi == G.job_list) {
6146 G.job_list = pi->next;
6148 prev_pipe = G.job_list;
6149 while (prev_pipe->next != pi)
6150 prev_pipe = prev_pipe->next;
6151 prev_pipe->next = pi->next;
6154 G.last_jobid = G.job_list->jobid;
6159 /* Remove a backgrounded job */
6160 static void delete_finished_bg_job(struct pipe *pi)
6167 /* Check to see if any processes have exited -- if they
6168 * have, figure out why and see if a job has completed */
6169 static int checkjobs(struct pipe *fg_pipe)
6179 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6181 attributes = WUNTRACED;
6182 if (fg_pipe == NULL)
6183 attributes |= WNOHANG;
6186 #if ENABLE_HUSH_FAST
6187 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6188 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6189 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6190 /* There was neither fork nor SIGCHLD since last waitpid */
6191 /* Avoid doing waitpid syscall if possible */
6192 if (!G.we_have_children) {
6196 if (fg_pipe == NULL) { /* is WNOHANG set? */
6197 /* We have children, but they did not exit
6198 * or stop yet (we saw no SIGCHLD) */
6201 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6205 /* Do we do this right?
6206 * bash-3.00# sleep 20 | false
6208 * [3]+ Stopped sleep 20 | false
6209 * bash-3.00# echo $?
6210 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6211 * [hush 1.14.0: yes we do it right]
6218 #if ENABLE_HUSH_FAST
6219 i = G.count_SIGCHLD;
6221 childpid = waitpid(-1, &status, attributes);
6222 if (childpid <= 0) {
6223 if (childpid && errno != ECHILD)
6224 bb_perror_msg("waitpid");
6225 #if ENABLE_HUSH_FAST
6226 else { /* Until next SIGCHLD, waitpid's are useless */
6227 G.we_have_children = (childpid == 0);
6228 G.handled_SIGCHLD = i;
6229 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6234 dead = WIFEXITED(status) || WIFSIGNALED(status);
6237 if (WIFSTOPPED(status))
6238 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6239 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6240 if (WIFSIGNALED(status))
6241 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6242 childpid, WTERMSIG(status), WEXITSTATUS(status));
6243 if (WIFEXITED(status))
6244 debug_printf_jobs("pid %d exited, exitcode %d\n",
6245 childpid, WEXITSTATUS(status));
6247 /* Were we asked to wait for fg pipe? */
6249 for (i = 0; i < fg_pipe->num_cmds; i++) {
6250 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6251 if (fg_pipe->cmds[i].pid != childpid)
6254 fg_pipe->cmds[i].pid = 0;
6255 fg_pipe->alive_cmds--;
6256 if (i == fg_pipe->num_cmds - 1) {
6257 /* last process gives overall exitstatus */
6258 rcode = WEXITSTATUS(status);
6259 /* bash prints killer signal's name for *last*
6260 * process in pipe (prints just newline for SIGINT).
6261 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6263 if (WIFSIGNALED(status)) {
6264 int sig = WTERMSIG(status);
6265 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
6266 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6267 * Maybe we need to use sig | 128? */
6270 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6273 fg_pipe->cmds[i].is_stopped = 1;
6274 fg_pipe->stopped_cmds++;
6276 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6277 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6278 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
6279 /* All processes in fg pipe have exited or stopped */
6280 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6281 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6282 * and "killall -STOP cat" */
6283 if (G_interactive_fd) {
6285 if (fg_pipe->alive_cmds)
6286 insert_bg_job(fg_pipe);
6290 if (!fg_pipe->alive_cmds)
6293 /* There are still running processes in the fg pipe */
6294 goto wait_more; /* do waitpid again */
6296 /* it wasnt fg_pipe, look for process in bg pipes */
6300 /* We asked to wait for bg or orphaned children */
6301 /* No need to remember exitcode in this case */
6302 for (pi = G.job_list; pi; pi = pi->next) {
6303 for (i = 0; i < pi->num_cmds; i++) {
6304 if (pi->cmds[i].pid == childpid)
6305 goto found_pi_and_prognum;
6308 /* Happens when shell is used as init process (init=/bin/sh) */
6309 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6310 continue; /* do waitpid again */
6312 found_pi_and_prognum:
6315 pi->cmds[i].pid = 0;
6317 if (!pi->alive_cmds) {
6318 if (G_interactive_fd)
6319 printf(JOB_STATUS_FORMAT, pi->jobid,
6320 "Done", pi->cmdtext);
6321 delete_finished_bg_job(pi);
6325 pi->cmds[i].is_stopped = 1;
6329 } /* while (waitpid succeeds)... */
6335 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6338 int rcode = checkjobs(fg_pipe);
6339 if (G_saved_tty_pgrp) {
6340 /* Job finished, move the shell to the foreground */
6341 p = getpgrp(); /* our process group id */
6342 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6343 tcsetpgrp(G_interactive_fd, p);
6349 /* Start all the jobs, but don't wait for anything to finish.
6352 * Return code is normally -1, when the caller has to wait for children
6353 * to finish to determine the exit status of the pipe. If the pipe
6354 * is a simple builtin command, however, the action is done by the
6355 * time run_pipe returns, and the exit code is provided as the
6358 * Returns -1 only if started some children. IOW: we have to
6359 * mask out retvals of builtins etc with 0xff!
6361 * The only case when we do not need to [v]fork is when the pipe
6362 * is single, non-backgrounded, non-subshell command. Examples:
6363 * cmd ; ... { list } ; ...
6364 * cmd && ... { list } && ...
6365 * cmd || ... { list } || ...
6366 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
6367 * or (if SH_STANDALONE) an applet, and we can run the { list }
6368 * with run_list. If it isn't one of these, we fork and exec cmd.
6370 * Cases when we must fork:
6371 * non-single: cmd | cmd
6372 * backgrounded: cmd & { list } &
6373 * subshell: ( list ) [&]
6375 #if !ENABLE_HUSH_MODE_X
6376 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, char argv_expanded) \
6377 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6379 static int redirect_and_varexp_helper(char ***new_env_p,
6380 struct variable **old_vars_p,
6381 struct command *command,
6383 char **argv_expanded)
6385 /* setup_redirects acts on file descriptors, not FILEs.
6386 * This is perfect for work that comes after exec().
6387 * Is it really safe for inline use? Experimentally,
6388 * things seem to work. */
6389 int rcode = setup_redirects(command, squirrel);
6391 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6392 *new_env_p = new_env;
6393 dump_cmd_in_x_mode(new_env);
6394 dump_cmd_in_x_mode(argv_expanded);
6396 *old_vars_p = set_vars_and_save_old(new_env);
6400 static NOINLINE int run_pipe(struct pipe *pi)
6402 static const char *const null_ptr = NULL;
6406 struct command *command;
6407 char **argv_expanded;
6409 /* it is not always needed, but we aim to smaller code */
6410 int squirrel[] = { -1, -1, -1 };
6413 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6416 IF_HUSH_JOB(pi->pgrp = -1;)
6417 pi->stopped_cmds = 0;
6418 command = &pi->cmds[0];
6419 argv_expanded = NULL;
6421 if (pi->num_cmds != 1
6422 || pi->followup == PIPE_BG
6423 || command->cmd_type == CMD_SUBSHELL
6430 debug_printf_exec(": group:%p argv:'%s'\n",
6431 command->group, command->argv ? command->argv[0] : "NONE");
6433 if (command->group) {
6434 #if ENABLE_HUSH_FUNCTIONS
6435 if (command->cmd_type == CMD_FUNCDEF) {
6436 /* "executing" func () { list } */
6437 struct function *funcp;
6439 funcp = new_function(command->argv[0]);
6440 /* funcp->name is already set to argv[0] */
6441 funcp->body = command->group;
6443 funcp->body_as_string = command->group_as_string;
6444 command->group_as_string = NULL;
6446 command->group = NULL;
6447 command->argv[0] = NULL;
6448 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6449 funcp->parent_cmd = command;
6450 command->child_func = funcp;
6452 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6454 return EXIT_SUCCESS;
6458 debug_printf("non-subshell group\n");
6459 rcode = 1; /* exitcode if redir failed */
6460 if (setup_redirects(command, squirrel) == 0) {
6461 debug_printf_exec(": run_list\n");
6462 rcode = run_list(command->group) & 0xff;
6464 restore_redirects(squirrel);
6465 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6467 debug_printf_exec("run_pipe: return %d\n", rcode);
6471 argv = command->argv ? command->argv : (char **) &null_ptr;
6473 const struct built_in_command *x;
6474 #if ENABLE_HUSH_FUNCTIONS
6475 const struct function *funcp;
6479 char **new_env = NULL;
6480 struct variable *old_vars = NULL;
6482 if (argv[command->assignment_cnt] == NULL) {
6483 /* Assignments, but no command */
6484 /* Ensure redirects take effect (that is, create files).
6485 * Try "a=t >file" */
6486 #if 0 /* A few cases in testsuite fail with this code. FIXME */
6487 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
6488 /* Set shell variables */
6492 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6493 /* Do we need to flag set_local_var() errors?
6494 * "assignment to readonly var" and "putenv error"
6499 /* Redirect error sets $? to 1. Otherwise,
6500 * if evaluating assignment value set $?, retain it.
6501 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6503 rcode = G.last_exitcode;
6504 /* Exit, _skipping_ variable restoring code: */
6505 goto clean_up_and_ret0;
6507 #else /* Older, bigger, but more correct code */
6509 rcode = setup_redirects(command, squirrel);
6510 restore_redirects(squirrel);
6511 /* Set shell variables */
6513 bb_putchar_stderr('+');
6515 char *p = expand_string_to_string(*argv);
6517 fprintf(stderr, " %s", p);
6518 debug_printf_exec("set shell var:'%s'->'%s'\n",
6520 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6521 /* Do we need to flag set_local_var() errors?
6522 * "assignment to readonly var" and "putenv error"
6527 bb_putchar_stderr('\n');
6528 /* Redirect error sets $? to 1. Otherwise,
6529 * if evaluating assignment value set $?, retain it.
6530 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6532 rcode = G.last_exitcode;
6533 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6535 debug_printf_exec("run_pipe: return %d\n", rcode);
6540 /* Expand the rest into (possibly) many strings each */
6542 #if ENABLE_HUSH_BASH_COMPAT
6543 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
6544 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
6548 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
6551 /* if someone gives us an empty string: `cmd with empty output` */
6552 if (!argv_expanded[0]) {
6553 free(argv_expanded);
6555 return G.last_exitcode;
6558 x = find_builtin(argv_expanded[0]);
6559 #if ENABLE_HUSH_FUNCTIONS
6562 funcp = find_function(argv_expanded[0]);
6566 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
6567 debug_printf("exec with redirects only\n");
6568 rcode = setup_redirects(command, NULL);
6569 goto clean_up_and_ret1;
6572 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6575 debug_printf_exec(": builtin '%s' '%s'...\n",
6576 x->b_cmd, argv_expanded[1]);
6577 rcode = x->b_function(argv_expanded) & 0xff;
6580 #if ENABLE_HUSH_FUNCTIONS
6582 # if ENABLE_HUSH_LOCAL
6583 struct variable **sv;
6584 sv = G.shadowed_vars_pp;
6585 G.shadowed_vars_pp = &old_vars;
6587 debug_printf_exec(": function '%s' '%s'...\n",
6588 funcp->name, argv_expanded[1]);
6589 rcode = run_function(funcp, argv_expanded) & 0xff;
6590 # if ENABLE_HUSH_LOCAL
6591 G.shadowed_vars_pp = sv;
6597 unset_vars(new_env);
6599 /* clean_up_and_ret0: */
6600 restore_redirects(squirrel);
6602 free(argv_expanded);
6603 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6605 debug_printf_exec("run_pipe return %d\n", rcode);
6609 if (ENABLE_FEATURE_SH_STANDALONE) {
6610 int n = find_applet_by_name(argv_expanded[0]);
6611 if (n >= 0 && APPLET_IS_NOFORK(n)) {
6612 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6614 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
6615 argv_expanded[0], argv_expanded[1]);
6616 rcode = run_nofork_applet(n, argv_expanded);
6618 goto clean_up_and_ret;
6621 /* It is neither builtin nor applet. We must fork. */
6625 /* NB: argv_expanded may already be created, and that
6626 * might include `cmd` runs! Do not rerun it! We *must*
6627 * use argv_expanded if it's non-NULL */
6629 /* Going to fork a child per each pipe member */
6634 while (cmd_no < pi->num_cmds) {
6635 struct fd_pair pipefds;
6637 volatile nommu_save_t nommu_save;
6638 nommu_save.new_env = NULL;
6639 nommu_save.old_vars = NULL;
6640 nommu_save.argv = NULL;
6641 nommu_save.argv_from_re_execing = NULL;
6643 command = &pi->cmds[cmd_no];
6645 if (command->argv) {
6646 debug_printf_exec(": pipe member '%s' '%s'...\n",
6647 command->argv[0], command->argv[1]);
6649 debug_printf_exec(": pipe member with no argv\n");
6652 /* pipes are inserted between pairs of commands */
6655 if (cmd_no < pi->num_cmds)
6656 xpiped_pair(pipefds);
6658 command->pid = BB_MMU ? fork() : vfork();
6659 if (!command->pid) { /* child */
6661 disable_restore_tty_pgrp_on_exit();
6662 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6664 /* Every child adds itself to new process group
6665 * with pgid == pid_of_first_child_in_pipe */
6666 if (G.run_list_level == 1 && G_interactive_fd) {
6669 if (pgrp < 0) /* true for 1st process only */
6671 if (setpgid(0, pgrp) == 0
6672 && pi->followup != PIPE_BG
6673 && G_saved_tty_pgrp /* we have ctty */
6675 /* We do it in *every* child, not just first,
6677 tcsetpgrp(G_interactive_fd, pgrp);
6681 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
6682 /* 1st cmd in backgrounded pipe
6683 * should have its stdin /dev/null'ed */
6685 if (open(bb_dev_null, O_RDONLY))
6686 xopen("/", O_RDONLY);
6688 xmove_fd(next_infd, 0);
6690 xmove_fd(pipefds.wr, 1);
6693 /* Like bash, explicit redirects override pipes,
6694 * and the pipe fd is available for dup'ing. */
6695 if (setup_redirects(command, NULL))
6698 /* Restore default handlers just prior to exec */
6699 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
6701 /* Stores to nommu_save list of env vars putenv'ed
6702 * (NOMMU, on MMU we don't need that) */
6703 /* cast away volatility... */
6704 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
6705 /* pseudo_exec() does not return */
6708 /* parent or error */
6709 #if ENABLE_HUSH_FAST
6711 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6713 enable_restore_tty_pgrp_on_exit();
6715 /* Clean up after vforked child */
6716 free(nommu_save.argv);
6717 free(nommu_save.argv_from_re_execing);
6718 unset_vars(nommu_save.new_env);
6719 add_vars(nommu_save.old_vars);
6721 free(argv_expanded);
6722 argv_expanded = NULL;
6723 if (command->pid < 0) { /* [v]fork failed */
6724 /* Clearly indicate, was it fork or vfork */
6725 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
6729 /* Second and next children need to know pid of first one */
6731 pi->pgrp = command->pid;
6737 if (cmd_no < pi->num_cmds)
6739 /* Pass read (output) pipe end to next iteration */
6740 next_infd = pipefds.rd;
6743 if (!pi->alive_cmds) {
6745 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
6750 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
6754 #ifndef debug_print_tree
6755 static void debug_print_tree(struct pipe *pi, int lvl)
6757 static const char *const PIPE[] = {
6763 static const char *RES[] = {
6764 [RES_NONE ] = "NONE" ,
6767 [RES_THEN ] = "THEN" ,
6768 [RES_ELIF ] = "ELIF" ,
6769 [RES_ELSE ] = "ELSE" ,
6772 # if ENABLE_HUSH_LOOPS
6773 [RES_FOR ] = "FOR" ,
6774 [RES_WHILE] = "WHILE",
6775 [RES_UNTIL] = "UNTIL",
6777 [RES_DONE ] = "DONE" ,
6779 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
6782 # if ENABLE_HUSH_CASE
6783 [RES_CASE ] = "CASE" ,
6784 [RES_CASE_IN ] = "CASE_IN" ,
6785 [RES_MATCH] = "MATCH",
6786 [RES_CASE_BODY] = "CASE_BODY",
6787 [RES_ESAC ] = "ESAC" ,
6789 [RES_XXXX ] = "XXXX" ,
6790 [RES_SNTX ] = "SNTX" ,
6792 static const char *const CMDTYPE[] = {
6796 # if ENABLE_HUSH_FUNCTIONS
6805 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
6806 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
6808 while (prn < pi->num_cmds) {
6809 struct command *command = &pi->cmds[prn];
6810 char **argv = command->argv;
6812 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
6814 command->assignment_cnt);
6815 if (command->group) {
6816 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
6817 CMDTYPE[command->cmd_type],
6820 , " group_as_string:", command->group_as_string
6825 debug_print_tree(command->group, lvl+1);
6829 if (argv) while (*argv) {
6830 fprintf(stderr, " '%s'", *argv);
6833 fprintf(stderr, "\n");
6840 #endif /* debug_print_tree */
6842 /* NB: called by pseudo_exec, and therefore must not modify any
6843 * global data until exec/_exit (we can be a child after vfork!) */
6844 static int run_list(struct pipe *pi)
6846 #if ENABLE_HUSH_CASE
6847 char *case_word = NULL;
6849 #if ENABLE_HUSH_LOOPS
6850 struct pipe *loop_top = NULL;
6851 char **for_lcur = NULL;
6852 char **for_list = NULL;
6854 smallint last_followup;
6856 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
6857 smalluint cond_code = 0;
6859 enum { cond_code = 0 };
6862 smallint rword; /* enum reserved_style */
6863 smallint last_rword; /* ditto */
6866 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
6869 #if ENABLE_HUSH_LOOPS
6870 /* Check syntax for "for" */
6871 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
6872 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
6874 /* current word is FOR or IN (BOLD in comments below) */
6875 if (cpipe->next == NULL) {
6876 syntax_error("malformed for");
6878 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
6881 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
6882 if (cpipe->next->res_word == RES_DO)
6884 /* next word is not "do". It must be "in" then ("FOR v in ...") */
6885 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
6886 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
6888 syntax_error("malformed for");
6890 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
6896 /* Past this point, all code paths should jump to ret: label
6897 * in order to return, no direct "return" statements please.
6898 * This helps to ensure that no memory is leaked. */
6906 last_rword = RES_XXXX;
6908 last_followup = PIPE_SEQ;
6909 rcode = G.last_exitcode;
6911 /* Go through list of pipes, (maybe) executing them. */
6912 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
6916 IF_HAS_KEYWORDS(rword = pi->res_word;)
6917 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
6918 rword, cond_code, last_rword);
6919 #if ENABLE_HUSH_LOOPS
6920 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
6921 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
6923 /* start of a loop: remember where loop starts */
6928 /* Still in the same "if...", "then..." or "do..." branch? */
6929 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
6930 if ((rcode == 0 && last_followup == PIPE_OR)
6931 || (rcode != 0 && last_followup == PIPE_AND)
6933 /* It is "<true> || CMD" or "<false> && CMD"
6934 * and we should not execute CMD */
6935 debug_printf_exec("skipped cmd because of || or &&\n");
6936 last_followup = pi->followup;
6940 last_followup = pi->followup;
6941 IF_HAS_KEYWORDS(last_rword = rword;)
6944 if (rword == RES_THEN) {
6945 /* if false; then ... fi has exitcode 0! */
6946 G.last_exitcode = rcode = EXIT_SUCCESS;
6947 /* "if <false> THEN cmd": skip cmd */
6951 if (rword == RES_ELSE || rword == RES_ELIF) {
6952 /* "if <true> then ... ELSE/ELIF cmd":
6953 * skip cmd and all following ones */
6958 #if ENABLE_HUSH_LOOPS
6959 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
6961 /* first loop through for */
6963 static const char encoded_dollar_at[] ALIGN1 = {
6964 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
6965 }; /* encoded representation of "$@" */
6966 static const char *const encoded_dollar_at_argv[] = {
6967 encoded_dollar_at, NULL
6968 }; /* argv list with one element: "$@" */
6971 vals = (char**)encoded_dollar_at_argv;
6972 if (pi->next->res_word == RES_IN) {
6973 /* if no variable values after "in" we skip "for" */
6974 if (!pi->next->cmds[0].argv) {
6975 G.last_exitcode = rcode = EXIT_SUCCESS;
6976 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
6979 vals = pi->next->cmds[0].argv;
6980 } /* else: "for var; do..." -> assume "$@" list */
6981 /* create list of variable values */
6982 debug_print_strings("for_list made from", vals);
6983 for_list = expand_strvec_to_strvec(vals);
6984 for_lcur = for_list;
6985 debug_print_strings("for_list", for_list);
6988 /* "for" loop is over, clean up */
6994 /* Insert next value from for_lcur */
6995 /* note: *for_lcur already has quotes removed, $var expanded, etc */
6996 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6999 if (rword == RES_IN) {
7000 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7002 if (rword == RES_DONE) {
7003 continue; /* "done" has no cmds too */
7006 #if ENABLE_HUSH_CASE
7007 if (rword == RES_CASE) {
7008 case_word = expand_strvec_to_string(pi->cmds->argv);
7011 if (rword == RES_MATCH) {
7014 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7016 /* all prev words didn't match, does this one match? */
7017 argv = pi->cmds->argv;
7019 char *pattern = expand_string_to_string(*argv);
7020 /* TODO: which FNM_xxx flags to use? */
7021 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7023 if (cond_code == 0) { /* match! we will execute this branch */
7024 free(case_word); /* make future "word)" stop */
7032 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7034 continue; /* not matched yet, skip this pipe */
7037 /* Just pressing <enter> in shell should check for jobs.
7038 * OTOH, in non-interactive shell this is useless
7039 * and only leads to extra job checks */
7040 if (pi->num_cmds == 0) {
7041 if (G_interactive_fd)
7042 goto check_jobs_and_continue;
7046 /* After analyzing all keywords and conditions, we decided
7047 * to execute this pipe. NB: have to do checkjobs(NULL)
7048 * after run_pipe to collect any background children,
7049 * even if list execution is to be stopped. */
7050 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7053 #if ENABLE_HUSH_LOOPS
7054 G.flag_break_continue = 0;
7056 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7058 /* We ran a builtin, function, or group.
7059 * rcode is already known
7060 * and we don't need to wait for anything. */
7061 G.last_exitcode = rcode;
7062 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7063 check_and_run_traps(0);
7064 #if ENABLE_HUSH_LOOPS
7065 /* Was it "break" or "continue"? */
7066 if (G.flag_break_continue) {
7067 smallint fbc = G.flag_break_continue;
7068 /* We might fall into outer *loop*,
7069 * don't want to break it too */
7071 G.depth_break_continue--;
7072 if (G.depth_break_continue == 0)
7073 G.flag_break_continue = 0;
7074 /* else: e.g. "continue 2" should *break* once, *then* continue */
7075 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7076 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
7077 goto check_jobs_and_break;
7078 /* "continue": simulate end of loop */
7083 #if ENABLE_HUSH_FUNCTIONS
7084 if (G.flag_return_in_progress == 1) {
7085 /* same as "goto check_jobs_and_break" */
7090 } else if (pi->followup == PIPE_BG) {
7091 /* What does bash do with attempts to background builtins? */
7092 /* even bash 3.2 doesn't do that well with nested bg:
7093 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7094 * I'm NOT treating inner &'s as jobs */
7095 check_and_run_traps(0);
7097 if (G.run_list_level == 1)
7100 /* Last command's pid goes to $! */
7101 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7102 G.last_exitcode = rcode = EXIT_SUCCESS;
7103 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7106 if (G.run_list_level == 1 && G_interactive_fd) {
7107 /* Waits for completion, then fg's main shell */
7108 rcode = checkjobs_and_fg_shell(pi);
7109 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7110 check_and_run_traps(0);
7113 { /* This one just waits for completion */
7114 rcode = checkjobs(pi);
7115 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7116 check_and_run_traps(0);
7118 G.last_exitcode = rcode;
7122 /* Analyze how result affects subsequent commands */
7124 if (rword == RES_IF || rword == RES_ELIF)
7127 #if ENABLE_HUSH_LOOPS
7128 /* Beware of "while false; true; do ..."! */
7129 if (pi->next && pi->next->res_word == RES_DO) {
7130 if (rword == RES_WHILE) {
7132 /* "while false; do...done" - exitcode 0 */
7133 G.last_exitcode = rcode = EXIT_SUCCESS;
7134 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7135 goto check_jobs_and_break;
7138 if (rword == RES_UNTIL) {
7140 debug_printf_exec(": until expr is true: breaking\n");
7141 check_jobs_and_break:
7149 check_jobs_and_continue:
7156 #if ENABLE_HUSH_LOOPS
7161 #if ENABLE_HUSH_CASE
7165 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7169 /* Select which version we will use */
7170 static int run_and_free_list(struct pipe *pi)
7173 debug_printf_exec("run_and_free_list entered\n");
7175 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7176 rcode = run_list(pi);
7178 /* free_pipe_list has the side effect of clearing memory.
7179 * In the long run that function can be merged with run_list,
7180 * but doing that now would hobble the debugging effort. */
7182 debug_printf_exec("run_and_free_list return %d\n", rcode);
7187 /* Called a few times only (or even once if "sh -c") */
7188 static void init_sigmasks(void)
7192 sigset_t old_blocked_set;
7194 if (!G.inherited_set_is_saved) {
7195 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
7196 G.inherited_set = G.blocked_set;
7198 old_blocked_set = G.blocked_set;
7200 mask = (1 << SIGQUIT);
7201 if (G_interactive_fd) {
7202 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
7203 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7204 mask |= SPECIAL_JOB_SIGS;
7206 G.non_DFL_mask = mask;
7211 sigaddset(&G.blocked_set, sig);
7215 sigdelset(&G.blocked_set, SIGCHLD);
7217 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
7218 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7220 /* POSIX allows shell to re-enable SIGCHLD
7221 * even if it was SIG_IGN on entry */
7222 #if ENABLE_HUSH_FAST
7223 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7224 if (!G.inherited_set_is_saved)
7225 signal(SIGCHLD, SIGCHLD_handler);
7227 if (!G.inherited_set_is_saved)
7228 signal(SIGCHLD, SIG_DFL);
7231 G.inherited_set_is_saved = 1;
7236 static void maybe_set_to_sigexit(int sig)
7238 void (*handler)(int);
7239 /* non_DFL_mask'ed signals are, well, masked,
7240 * no need to set handler for them.
7242 if (!((G.non_DFL_mask >> sig) & 1)) {
7243 handler = signal(sig, sigexit);
7244 if (handler == SIG_IGN) /* oops... restore back to IGN! */
7245 signal(sig, handler);
7248 /* Set handlers to restore tty pgrp and exit */
7249 static void set_fatal_handlers(void)
7251 /* We _must_ restore tty pgrp on fatal signals */
7253 maybe_set_to_sigexit(SIGILL );
7254 maybe_set_to_sigexit(SIGFPE );
7255 maybe_set_to_sigexit(SIGBUS );
7256 maybe_set_to_sigexit(SIGSEGV);
7257 maybe_set_to_sigexit(SIGTRAP);
7258 } /* else: hush is perfect. what SEGV? */
7259 maybe_set_to_sigexit(SIGABRT);
7260 /* bash 3.2 seems to handle these just like 'fatal' ones */
7261 maybe_set_to_sigexit(SIGPIPE);
7262 maybe_set_to_sigexit(SIGALRM);
7263 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
7264 * if we aren't interactive... but in this case
7265 * we never want to restore pgrp on exit, and this fn is not called */
7266 /*maybe_set_to_sigexit(SIGHUP );*/
7267 /*maybe_set_to_sigexit(SIGTERM);*/
7268 /*maybe_set_to_sigexit(SIGINT );*/
7272 static int set_mode(const char cstate, const char mode)
7274 int state = (cstate == '-' ? 1 : 0);
7276 case 'n': G.n_mode = state; break;
7277 case 'x': IF_HUSH_MODE_X(G_x_mode = state;) break;
7278 default: return EXIT_FAILURE;
7280 return EXIT_SUCCESS;
7283 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7284 int hush_main(int argc, char **argv)
7287 unsigned builtin_argc;
7289 struct variable *cur_var;
7292 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
7293 G.last_exitcode = EXIT_SUCCESS;
7295 G.argv0_for_re_execing = argv[0];
7297 /* Deal with HUSH_VERSION */
7298 G.shell_ver.flg_export = 1;
7299 G.shell_ver.flg_read_only = 1;
7300 /* Code which handles ${var/P/R} needs writable values for all variables,
7301 * therefore we xstrdup: */
7302 G.shell_ver.varstr = xstrdup(hush_version_str),
7303 G.top_var = &G.shell_ver;
7304 /* Create shell local variables from the values
7305 * currently living in the environment */
7306 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7307 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7308 cur_var = G.top_var;
7311 char *value = strchr(*e, '=');
7312 if (value) { /* paranoia */
7313 cur_var->next = xzalloc(sizeof(*cur_var));
7314 cur_var = cur_var->next;
7315 cur_var->varstr = *e;
7316 cur_var->max_len = strlen(*e);
7317 cur_var->flg_export = 1;
7321 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7322 debug_printf_env("putenv '%s'\n", G.shell_ver.varstr);
7323 putenv(G.shell_ver.varstr);
7326 set_pwd_var(/*exp:*/ 1);
7327 /* bash also exports SHLVL and _,
7328 * and sets (but doesn't export) the following variables:
7330 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7331 * BASH_VERSION='3.2.0(1)-release'
7333 * MACHTYPE=i386-pc-linux-gnu
7335 * HOSTNAME=<xxxxxxxxxx>
7336 * PPID=<NNNNN> - we also do it elsewhere
7347 * PIPESTATUS=([0]="0")
7348 * HISTFILE=/<xxx>/.bash_history
7352 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7354 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7364 #if ENABLE_FEATURE_EDITING
7365 G.line_input_state = new_line_input_t(FOR_SHELL);
7367 G.global_argc = argc;
7368 G.global_argv = argv;
7369 /* Initialize some more globals to non-zero values */
7370 cmdedit_update_prompt();
7372 if (setjmp(die_jmp)) {
7373 /* xfunc has failed! die die die */
7374 /* no EXIT traps, this is an escape hatch! */
7376 hush_exit(xfunc_error_retval);
7379 /* Shell is non-interactive at first. We need to call
7380 * init_sigmasks() if we are going to execute "sh <script>",
7381 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7382 * If we later decide that we are interactive, we run init_sigmasks()
7383 * in order to intercept (more) signals.
7387 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7390 opt = getopt(argc, argv, "+c:xins"
7393 # if ENABLE_HUSH_FUNCTIONS
7403 * sh ... -c 'script'
7404 * sh ... -c 'script' ARG0 [ARG1...]
7405 * On NOMMU, if builtin_argc != 0,
7406 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7407 * "" needs to be replaced with NULL
7408 * and BARGV vector fed to builtin function.
7409 * Note: the form without ARG0 never happens:
7410 * sh ... -c 'builtin' BARGV... ""
7413 G.root_pid = getpid();
7414 G.root_ppid = getppid();
7416 G.global_argv = argv + optind;
7417 G.global_argc = argc - optind;
7419 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7420 const struct built_in_command *x;
7423 x = find_builtin(optarg);
7424 if (x) { /* paranoia */
7425 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7426 G.global_argv += builtin_argc;
7427 G.global_argv[-1] = NULL; /* replace "" */
7428 G.last_exitcode = x->b_function(argv + optind - 1);
7432 if (!G.global_argv[0]) {
7433 /* -c 'script' (no params): prevent empty $0 */
7434 G.global_argv--; /* points to argv[i] of 'script' */
7435 G.global_argv[0] = argv[0];
7437 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7439 parse_and_run_string(optarg);
7442 /* Well, we cannot just declare interactiveness,
7443 * we have to have some stuff (ctty, etc) */
7444 /* G_interactive_fd++; */
7447 /* "-s" means "read from stdin", but this is how we always
7448 * operate, so simply do nothing here. */
7451 case '<': /* "big heredoc" support */
7452 full_write1_str(optarg);
7455 unsigned long long empty_trap_mask;
7457 G.root_pid = bb_strtou(optarg, &optarg, 16);
7459 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7461 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7463 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7465 builtin_argc = bb_strtou(optarg, &optarg, 16);
7467 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7468 if (empty_trap_mask != 0) {
7471 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7472 for (sig = 1; sig < NSIG; sig++) {
7473 if (empty_trap_mask & (1LL << sig)) {
7474 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7475 sigaddset(&G.blocked_set, sig);
7478 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7480 # if ENABLE_HUSH_LOOPS
7482 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7488 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7490 # if ENABLE_HUSH_FUNCTIONS
7492 struct function *funcp = new_function(optarg);
7493 /* funcp->name is already set to optarg */
7494 /* funcp->body is set to NULL. It's a special case. */
7495 funcp->body_as_string = argv[optind];
7503 if (set_mode('-', opt) == 0) /* no error */
7507 fprintf(stderr, "Usage: sh [FILE]...\n"
7508 " or: sh -c command [args]...\n\n");
7514 } /* option parsing loop */
7517 G.root_pid = getpid();
7518 G.root_ppid = getppid();
7521 /* If we are login shell... */
7522 if (argv[0] && argv[0][0] == '-') {
7524 debug_printf("sourcing /etc/profile\n");
7525 input = fopen_for_read("/etc/profile");
7526 if (input != NULL) {
7527 close_on_exec_on(fileno(input));
7529 parse_and_run_file(input);
7532 /* bash: after sourcing /etc/profile,
7533 * tries to source (in the given order):
7534 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7535 * stopping on first found. --noprofile turns this off.
7536 * bash also sources ~/.bash_logout on exit.
7537 * If called as sh, skips .bash_XXX files.
7544 * "bash <script>" (which is never interactive (unless -i?))
7545 * sources $BASH_ENV here (without scanning $PATH).
7546 * If called as sh, does the same but with $ENV.
7548 debug_printf("running script '%s'\n", argv[optind]);
7549 G.global_argv = argv + optind;
7550 G.global_argc = argc - optind;
7551 input = xfopen_for_read(argv[optind]);
7552 close_on_exec_on(fileno(input));
7554 parse_and_run_file(input);
7555 #if ENABLE_FEATURE_CLEAN_UP
7561 /* Up to here, shell was non-interactive. Now it may become one.
7562 * NB: don't forget to (re)run init_sigmasks() as needed.
7565 /* A shell is interactive if the '-i' flag was given,
7566 * or if all of the following conditions are met:
7568 * no arguments remaining or the -s flag given
7569 * standard input is a terminal
7570 * standard output is a terminal
7571 * Refer to Posix.2, the description of the 'sh' utility.
7574 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7575 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7576 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7577 if (G_saved_tty_pgrp < 0)
7578 G_saved_tty_pgrp = 0;
7580 /* try to dup stdin to high fd#, >= 255 */
7581 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7582 if (G_interactive_fd < 0) {
7583 /* try to dup to any fd */
7584 G_interactive_fd = dup(STDIN_FILENO);
7585 if (G_interactive_fd < 0) {
7587 G_interactive_fd = 0;
7588 G_saved_tty_pgrp = 0;
7591 // TODO: track & disallow any attempts of user
7592 // to (inadvertently) close/redirect G_interactive_fd
7594 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7595 if (G_interactive_fd) {
7596 close_on_exec_on(G_interactive_fd);
7598 if (G_saved_tty_pgrp) {
7599 /* If we were run as 'hush &', sleep until we are
7600 * in the foreground (tty pgrp == our pgrp).
7601 * If we get started under a job aware app (like bash),
7602 * make sure we are now in charge so we don't fight over
7603 * who gets the foreground */
7605 pid_t shell_pgrp = getpgrp();
7606 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7607 if (G_saved_tty_pgrp == shell_pgrp)
7609 /* send TTIN to ourself (should stop us) */
7610 kill(- shell_pgrp, SIGTTIN);
7614 /* Block some signals */
7617 if (G_saved_tty_pgrp) {
7618 /* Set other signals to restore saved_tty_pgrp */
7619 set_fatal_handlers();
7620 /* Put ourselves in our own process group
7621 * (bash, too, does this only if ctty is available) */
7622 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7623 /* Grab control of the terminal */
7624 tcsetpgrp(G_interactive_fd, getpid());
7626 /* -1 is special - makes xfuncs longjmp, not exit
7627 * (we reset die_sleep = 0 whereever we [v]fork) */
7628 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7632 #elif ENABLE_HUSH_INTERACTIVE
7633 /* No job control compiled in, only prompt/line editing */
7634 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7635 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7636 if (G_interactive_fd < 0) {
7637 /* try to dup to any fd */
7638 G_interactive_fd = dup(STDIN_FILENO);
7639 if (G_interactive_fd < 0)
7641 G_interactive_fd = 0;
7644 if (G_interactive_fd) {
7645 close_on_exec_on(G_interactive_fd);
7649 /* We have interactiveness code disabled */
7653 * if interactive but not a login shell, sources ~/.bashrc
7654 * (--norc turns this off, --rcfile <file> overrides)
7657 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7658 /* note: ash and hush share this string */
7659 printf("\n\n%s %s\n"
7660 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7663 "hush - the humble shell"
7667 parse_and_run_file(stdin);
7670 #if ENABLE_FEATURE_CLEAN_UP
7671 if (G.cwd != bb_msg_unknown)
7673 cur_var = G.top_var->next;
7675 struct variable *tmp = cur_var;
7676 if (!cur_var->max_len)
7677 free(cur_var->varstr);
7678 cur_var = cur_var->next;
7682 hush_exit(G.last_exitcode);
7687 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7688 int msh_main(int argc, char **argv)
7690 //bb_error_msg("msh is deprecated, please use hush instead");
7691 return hush_main(argc, argv);
7699 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7704 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7711 return applet_main_func(argc, argv - argc);
7714 static int FAST_FUNC builtin_test(char **argv)
7716 return run_applet_main(argv, test_main);
7719 static int FAST_FUNC builtin_echo(char **argv)
7721 return run_applet_main(argv, echo_main);
7725 static int FAST_FUNC builtin_printf(char **argv)
7727 return run_applet_main(argv, printf_main);
7731 static char **skip_dash_dash(char **argv)
7734 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7739 static int FAST_FUNC builtin_eval(char **argv)
7741 int rcode = EXIT_SUCCESS;
7743 argv = skip_dash_dash(argv);
7745 char *str = expand_strvec_to_string(argv);
7747 * eval "echo Hi; done" ("done" is syntax error):
7748 * "echo Hi" will not execute too.
7750 parse_and_run_string(str);
7752 rcode = G.last_exitcode;
7757 static int FAST_FUNC builtin_cd(char **argv)
7761 argv = skip_dash_dash(argv);
7763 if (newdir == NULL) {
7764 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7765 * bash says "bash: cd: HOME not set" and does nothing
7768 const char *home = get_local_var_value("HOME");
7769 newdir = home ? home : "/";
7771 if (chdir(newdir)) {
7772 /* Mimic bash message exactly */
7773 bb_perror_msg("cd: %s", newdir);
7774 return EXIT_FAILURE;
7776 /* Read current dir (get_cwd(1) is inside) and set PWD.
7777 * Note: do not enforce exporting. If PWD was unset or unexported,
7778 * set it again, but do not export. bash does the same.
7780 set_pwd_var(/*exp:*/ 0);
7781 return EXIT_SUCCESS;
7784 static int FAST_FUNC builtin_exec(char **argv)
7786 argv = skip_dash_dash(argv);
7787 if (argv[0] == NULL)
7788 return EXIT_SUCCESS; /* bash does this */
7790 /* Careful: we can end up here after [v]fork. Do not restore
7791 * tty pgrp then, only top-level shell process does that */
7792 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7793 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7795 /* TODO: if exec fails, bash does NOT exit! We do.
7796 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7797 * and tcsetpgrp, and this is inherently racy.
7799 execvp_or_die(argv);
7802 static int FAST_FUNC builtin_exit(char **argv)
7804 debug_printf_exec("%s()\n", __func__);
7806 /* interactive bash:
7807 * # trap "echo EEE" EXIT
7810 * There are stopped jobs.
7811 * (if there are _stopped_ jobs, running ones don't count)
7814 # EEE (then bash exits)
7816 * we can use G.exiting = -1 as indicator "last cmd was exit"
7819 /* note: EXIT trap is run by hush_exit */
7820 argv = skip_dash_dash(argv);
7821 if (argv[0] == NULL)
7822 hush_exit(G.last_exitcode);
7823 /* mimic bash: exit 123abc == exit 255 + error msg */
7824 xfunc_error_retval = 255;
7825 /* bash: exit -2 == exit 254, no error msg */
7826 hush_exit(xatoi(argv[0]) & 0xff);
7829 static void print_escaped(const char *s)
7834 const char *p = strchrnul(s, '\'');
7835 /* print 'xxxx', possibly just '' */
7836 printf("'%.*s'", (int)(p - s), s);
7841 /* s points to '; print "'''...'''" */
7843 do putchar('\''); while (*++s == '\'');
7848 #if !ENABLE_HUSH_LOCAL
7849 #define helper_export_local(argv, exp, lvl) \
7850 helper_export_local(argv, exp)
7852 static void helper_export_local(char **argv, int exp, int lvl)
7856 char *name_end = strchrnul(name, '=');
7858 /* So far we do not check that name is valid (TODO?) */
7860 if (*name_end == '\0') {
7861 struct variable *var, **vpp;
7863 vpp = get_ptr_to_local_var(name, name_end - name);
7864 var = vpp ? *vpp : NULL;
7866 if (exp == -1) { /* unexporting? */
7867 /* export -n NAME (without =VALUE) */
7869 var->flg_export = 0;
7870 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7872 } /* else: export -n NOT_EXISTING_VAR: no-op */
7875 if (exp == 1) { /* exporting? */
7876 /* export NAME (without =VALUE) */
7878 var->flg_export = 1;
7879 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7880 putenv(var->varstr);
7884 /* Exporting non-existing variable.
7885 * bash does not put it in environment,
7886 * but remembers that it is exported,
7887 * and does put it in env when it is set later.
7888 * We just set it to "" and export. */
7889 /* Or, it's "local NAME" (without =VALUE).
7890 * bash sets the value to "". */
7891 name = xasprintf("%s=", name);
7893 /* (Un)exporting/making local NAME=VALUE */
7894 name = xstrdup(name);
7896 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7900 static int FAST_FUNC builtin_export(char **argv)
7902 unsigned opt_unexport;
7904 #if ENABLE_HUSH_EXPORT_N
7905 /* "!": do not abort on errors */
7906 opt_unexport = getopt32(argv, "!n");
7907 if (opt_unexport == (uint32_t)-1)
7908 return EXIT_FAILURE;
7915 if (argv[0] == NULL) {
7922 /* ash emits: export VAR='VAL'
7923 * bash: declare -x VAR="VAL"
7924 * we follow ash example */
7925 const char *s = *e++;
7926 const char *p = strchr(s, '=');
7928 if (!p) /* wtf? take next variable */
7931 printf("export %.*s", (int)(p - s) + 1, s);
7932 print_escaped(p + 1);
7936 /*fflush_all(); - done after each builtin anyway */
7938 return EXIT_SUCCESS;
7941 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7943 return EXIT_SUCCESS;
7946 #if ENABLE_HUSH_LOCAL
7947 static int FAST_FUNC builtin_local(char **argv)
7949 if (G.func_nest_level == 0) {
7950 bb_error_msg("%s: not in a function", argv[0]);
7951 return EXIT_FAILURE; /* bash compat */
7953 helper_export_local(argv, 0, G.func_nest_level);
7954 return EXIT_SUCCESS;
7958 static int FAST_FUNC builtin_trap(char **argv)
7964 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7969 /* No args: print all trapped */
7970 for (i = 0; i < NSIG; ++i) {
7973 print_escaped(G.traps[i]);
7974 /* note: bash adds "SIG", but only if invoked
7975 * as "bash". If called as "sh", or if set -o posix,
7976 * then it prints short signal names.
7977 * We are printing short names: */
7978 printf(" %s\n", get_signame(i));
7981 /*fflush_all(); - done after each builtin anyway */
7982 return EXIT_SUCCESS;
7986 /* If first arg is a number: reset all specified signals */
7987 sig = bb_strtou(*argv, NULL, 10);
7993 sig = get_signum(*argv++);
7994 if (sig < 0 || sig >= NSIG) {
7996 /* Mimic bash message exactly */
7997 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8002 G.traps[sig] = xstrdup(new_cmd);
8004 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8005 get_signame(sig), sig, G.traps[sig]);
8007 /* There is no signal for 0 (EXIT) */
8012 sigaddset(&G.blocked_set, sig);
8014 /* There was a trap handler, we are removing it
8015 * (if sig has non-DFL handling,
8016 * we don't need to do anything) */
8017 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
8019 sigdelset(&G.blocked_set, sig);
8022 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8026 if (!argv[1]) { /* no second arg */
8027 bb_error_msg("trap: invalid arguments");
8028 return EXIT_FAILURE;
8031 /* First arg is "-": reset all specified to default */
8032 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8033 /* Everything else: set arg as signal handler
8034 * (includes "" case, which ignores signal) */
8035 if (argv[0][0] == '-') {
8036 if (argv[0][1] == '\0') { /* "-" */
8037 /* new_cmd remains NULL: "reset these sigs" */
8040 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8043 /* else: "-something", no special meaning */
8048 goto process_sig_list;
8051 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8052 static int FAST_FUNC builtin_type(char **argv)
8054 int ret = EXIT_SUCCESS;
8060 if (0) {} /* make conditional compile easier below */
8061 /*else if (find_alias(*argv))
8062 type = "an alias";*/
8063 #if ENABLE_HUSH_FUNCTIONS
8064 else if (find_function(*argv))
8065 type = "a function";
8067 else if (find_builtin(*argv))
8068 type = "a shell builtin";
8069 else if ((path = find_in_path(*argv)) != NULL)
8072 bb_error_msg("type: %s: not found", *argv);
8077 printf("%s is %s\n", *argv, type);
8085 /* built-in 'fg' and 'bg' handler */
8086 static int FAST_FUNC builtin_fg_bg(char **argv)
8091 if (!G_interactive_fd)
8092 return EXIT_FAILURE;
8094 /* If they gave us no args, assume they want the last backgrounded task */
8096 for (pi = G.job_list; pi; pi = pi->next) {
8097 if (pi->jobid == G.last_jobid) {
8101 bb_error_msg("%s: no current job", argv[0]);
8102 return EXIT_FAILURE;
8104 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8105 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8106 return EXIT_FAILURE;
8108 for (pi = G.job_list; pi; pi = pi->next) {
8109 if (pi->jobid == jobnum) {
8113 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8114 return EXIT_FAILURE;
8116 /* TODO: bash prints a string representation
8117 * of job being foregrounded (like "sleep 1 | cat") */
8118 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8119 /* Put the job into the foreground. */
8120 tcsetpgrp(G_interactive_fd, pi->pgrp);
8123 /* Restart the processes in the job */
8124 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8125 for (i = 0; i < pi->num_cmds; i++) {
8126 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8127 pi->cmds[i].is_stopped = 0;
8129 pi->stopped_cmds = 0;
8131 i = kill(- pi->pgrp, SIGCONT);
8133 if (errno == ESRCH) {
8134 delete_finished_bg_job(pi);
8135 return EXIT_SUCCESS;
8137 bb_perror_msg("kill (SIGCONT)");
8140 if (argv[0][0] == 'f') {
8142 return checkjobs_and_fg_shell(pi);
8144 return EXIT_SUCCESS;
8148 #if ENABLE_HUSH_HELP
8149 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8151 const struct built_in_command *x;
8154 "Built-in commands:\n"
8155 "------------------\n");
8156 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8158 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8161 return EXIT_SUCCESS;
8166 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8169 const char *status_string;
8171 for (job = G.job_list; job; job = job->next) {
8172 if (job->alive_cmds == job->stopped_cmds)
8173 status_string = "Stopped";
8175 status_string = "Running";
8177 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8179 return EXIT_SUCCESS;
8184 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8189 # ifdef M_TRIM_THRESHOLD
8190 /* Optional. Reduces probability of false positives */
8193 /* Crude attempt to find where "free memory" starts,
8194 * sans fragmentation. */
8196 l = (unsigned long)p;
8199 if (l < (unsigned long)p) l = (unsigned long)p;
8202 if (!G.memleak_value)
8203 G.memleak_value = l;
8205 l -= G.memleak_value;
8212 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8217 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8220 return EXIT_SUCCESS;
8223 static int FAST_FUNC builtin_read(char **argv)
8232 /* "!": do not abort on errors.
8233 * Option string must start with "sr" to match BUILTIN_READ_xxx
8235 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8236 if (read_flags == (uint32_t)-1)
8237 return EXIT_FAILURE;
8240 r = shell_builtin_read(set_local_var_from_halves,
8242 get_local_var_value("IFS"), /* can be NULL */
8250 if ((uintptr_t)r > 1) {
8251 bb_error_msg("%s", r);
8252 r = (char*)(uintptr_t)1;
8255 return (uintptr_t)r;
8258 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8259 * built-in 'set' handler
8261 * set [-abCefhmnuvx] [-o option] [argument...]
8262 * set [+abCefhmnuvx] [+o option] [argument...]
8263 * set -- [argument...]
8266 * Implementations shall support the options in both their hyphen and
8267 * plus-sign forms. These options can also be specified as options to sh.
8269 * Write out all variables and their values: set
8270 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8271 * Turn on the -x and -v options: set -xv
8272 * Unset all positional parameters: set --
8273 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8274 * Set the positional parameters to the expansion of x, even if x expands
8275 * with a leading '-' or '+': set -- $x
8277 * So far, we only support "set -- [argument...]" and some of the short names.
8279 static int FAST_FUNC builtin_set(char **argv)
8282 char **pp, **g_argv;
8283 char *arg = *++argv;
8287 for (e = G.top_var; e; e = e->next)
8289 return EXIT_SUCCESS;
8293 if (!strcmp(arg, "--")) {
8297 if (arg[0] != '+' && arg[0] != '-')
8299 for (n = 1; arg[n]; ++n)
8300 if (set_mode(arg[0], arg[n]))
8302 } while ((arg = *++argv) != NULL);
8303 /* Now argv[0] is 1st argument */
8306 return EXIT_SUCCESS;
8309 /* NB: G.global_argv[0] ($0) is never freed/changed */
8310 g_argv = G.global_argv;
8311 if (G.global_args_malloced) {
8317 G.global_args_malloced = 1;
8318 pp = xzalloc(sizeof(pp[0]) * 2);
8319 pp[0] = g_argv[0]; /* retain $0 */
8322 /* This realloc's G.global_argv */
8323 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8330 return EXIT_SUCCESS;
8332 /* Nothing known, so abort */
8334 bb_error_msg("set: %s: invalid option", arg);
8335 return EXIT_FAILURE;
8338 static int FAST_FUNC builtin_shift(char **argv)
8341 argv = skip_dash_dash(argv);
8345 if (n >= 0 && n < G.global_argc) {
8346 if (G.global_args_malloced) {
8349 free(G.global_argv[m++]);
8352 memmove(&G.global_argv[1], &G.global_argv[n+1],
8353 G.global_argc * sizeof(G.global_argv[0]));
8354 return EXIT_SUCCESS;
8356 return EXIT_FAILURE;
8359 static int FAST_FUNC builtin_source(char **argv)
8361 char *arg_path, *filename;
8364 #if ENABLE_HUSH_FUNCTIONS
8368 argv = skip_dash_dash(argv);
8371 /* bash says: "bash: .: filename argument required" */
8372 return 2; /* bash compat */
8375 if (!strchr(filename, '/')) {
8376 arg_path = find_in_path(filename);
8378 filename = arg_path;
8380 input = fopen_or_warn(filename, "r");
8383 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8384 return EXIT_FAILURE;
8386 close_on_exec_on(fileno(input));
8388 #if ENABLE_HUSH_FUNCTIONS
8389 sv_flg = G.flag_return_in_progress;
8390 /* "we are inside sourced file, ok to use return" */
8391 G.flag_return_in_progress = -1;
8393 save_and_replace_G_args(&sv, argv);
8395 parse_and_run_file(input);
8398 restore_G_args(&sv, argv);
8399 #if ENABLE_HUSH_FUNCTIONS
8400 G.flag_return_in_progress = sv_flg;
8403 return G.last_exitcode;
8406 static int FAST_FUNC builtin_umask(char **argv)
8412 argv = skip_dash_dash(argv);
8414 mode_t old_mask = mask;
8417 rc = bb_parse_mode(argv[0], &mask);
8422 * bash: umask: 'q': invalid symbolic mode operator
8423 * bash: umask: 999: octal number out of range
8425 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8430 printf("%04o\n", (unsigned) mask);
8431 /* fall through and restore mask which we set to 0 */
8435 return !rc; /* rc != 0 - success */
8438 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8439 static int FAST_FUNC builtin_unset(char **argv)
8444 /* "!": do not abort on errors */
8445 /* "+": stop at 1st non-option */
8446 opts = getopt32(argv, "!+vf");
8447 if (opts == (unsigned)-1)
8448 return EXIT_FAILURE;
8450 bb_error_msg("unset: -v and -f are exclusive");
8451 return EXIT_FAILURE;
8457 if (!(opts & 2)) { /* not -f */
8458 if (unset_local_var(*argv)) {
8459 /* unset <nonexistent_var> doesn't fail.
8460 * Error is when one tries to unset RO var.
8461 * Message was printed by unset_local_var. */
8465 #if ENABLE_HUSH_FUNCTIONS
8475 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8476 static int FAST_FUNC builtin_wait(char **argv)
8478 int ret = EXIT_SUCCESS;
8481 argv = skip_dash_dash(argv);
8482 if (argv[0] == NULL) {
8483 /* Don't care about wait results */
8484 /* Note 1: must wait until there are no more children */
8485 /* Note 2: must be interruptible */
8487 * $ sleep 3 & sleep 6 & wait
8492 * $ sleep 3 & sleep 6 & wait
8496 * ^C <-- after ~4 sec from keyboard
8499 sigaddset(&G.blocked_set, SIGCHLD);
8500 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8503 if (errno == ECHILD)
8505 /* Wait for SIGCHLD or any other signal of interest */
8506 /* sigtimedwait with infinite timeout: */
8507 sig = sigwaitinfo(&G.blocked_set, NULL);
8509 sig = check_and_run_traps(sig);
8510 if (sig && sig != SIGCHLD) { /* see note 2 */
8516 sigdelset(&G.blocked_set, SIGCHLD);
8517 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8521 /* This is probably buggy wrt interruptible-ness */
8523 pid_t pid = bb_strtou(*argv, NULL, 10);
8525 /* mimic bash message */
8526 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8527 return EXIT_FAILURE;
8529 if (waitpid(pid, &status, 0) == pid) {
8530 if (WIFSIGNALED(status))
8531 ret = 128 + WTERMSIG(status);
8532 else if (WIFEXITED(status))
8533 ret = WEXITSTATUS(status);
8537 bb_perror_msg("wait %s", *argv);
8546 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8547 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8550 def = bb_strtou(argv[1], NULL, 10);
8551 if (errno || def < def_min || argv[2]) {
8552 bb_error_msg("%s: bad arguments", argv[0]);
8560 #if ENABLE_HUSH_LOOPS
8561 static int FAST_FUNC builtin_break(char **argv)
8564 if (G.depth_of_loop == 0) {
8565 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8566 return EXIT_SUCCESS; /* bash compat */
8568 G.flag_break_continue++; /* BC_BREAK = 1 */
8570 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8571 if (depth == UINT_MAX)
8572 G.flag_break_continue = BC_BREAK;
8573 if (G.depth_of_loop < depth)
8574 G.depth_break_continue = G.depth_of_loop;
8576 return EXIT_SUCCESS;
8579 static int FAST_FUNC builtin_continue(char **argv)
8581 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8582 return builtin_break(argv);
8586 #if ENABLE_HUSH_FUNCTIONS
8587 static int FAST_FUNC builtin_return(char **argv)
8591 if (G.flag_return_in_progress != -1) {
8592 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8593 return EXIT_FAILURE; /* bash compat */
8596 G.flag_return_in_progress = 1;
8599 * out of range: wraps around at 256, does not error out
8600 * non-numeric param:
8601 * f() { false; return qwe; }; f; echo $?
8602 * bash: return: qwe: numeric argument required <== we do this
8603 * 255 <== we also do this
8605 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);