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 ""
237 //usage:#define sh_trivial_usage NOUSAGE_STR
238 //usage:#define sh_full_usage ""
239 //usage:#define bash_trivial_usage NOUSAGE_STR
240 //usage:#define bash_full_usage ""
244 #define LEAK_HUNTING 0
245 #define BUILD_AS_NOMMU 0
246 /* Enable/disable sanity checks. Ok to enable in production,
247 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
248 * Keeping 1 for now even in released versions.
251 /* Slightly bigger (+200 bytes), but faster hush.
252 * So far it only enables a trick with counting SIGCHLDs and forks,
253 * which allows us to do fewer waitpid's.
254 * (we can detect a case where neither forks were done nor SIGCHLDs happened
255 * and therefore waitpid will return the same result as last time)
257 #define ENABLE_HUSH_FAST 0
258 /* TODO: implement simplified code for users which do not need ${var%...} ops
259 * So far ${var%...} ops are always enabled:
261 #define ENABLE_HUSH_DOLLAR_OPS 1
266 # undef USE_FOR_NOMMU
269 # define USE_FOR_NOMMU(...) __VA_ARGS__
270 # define USE_FOR_MMU(...)
273 #include "NUM_APPLETS.h"
275 /* STANDALONE does not make sense, and won't compile */
276 # undef CONFIG_FEATURE_SH_STANDALONE
277 # undef ENABLE_FEATURE_SH_STANDALONE
278 # undef IF_FEATURE_SH_STANDALONE
279 # undef IF_NOT_FEATURE_SH_STANDALONE
280 # define ENABLE_FEATURE_SH_STANDALONE 0
281 # define IF_FEATURE_SH_STANDALONE(...)
282 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
285 #if !ENABLE_HUSH_INTERACTIVE
286 # undef ENABLE_FEATURE_EDITING
287 # define ENABLE_FEATURE_EDITING 0
288 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
289 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
292 /* Do we support ANY keywords? */
293 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
294 # define HAS_KEYWORDS 1
295 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
296 # define IF_HAS_NO_KEYWORDS(...)
298 # define HAS_KEYWORDS 0
299 # define IF_HAS_KEYWORDS(...)
300 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
303 /* If you comment out one of these below, it will be #defined later
304 * to perform debug printfs to stderr: */
305 #define debug_printf(...) do {} while (0)
306 /* Finer-grained debug switches */
307 #define debug_printf_parse(...) do {} while (0)
308 #define debug_print_tree(a, b) do {} while (0)
309 #define debug_printf_exec(...) do {} while (0)
310 #define debug_printf_env(...) do {} while (0)
311 #define debug_printf_jobs(...) do {} while (0)
312 #define debug_printf_expand(...) do {} while (0)
313 #define debug_printf_varexp(...) do {} while (0)
314 #define debug_printf_glob(...) do {} while (0)
315 #define debug_printf_list(...) do {} while (0)
316 #define debug_printf_subst(...) do {} while (0)
317 #define debug_printf_clean(...) do {} while (0)
319 #define ERR_PTR ((void*)(long)1)
321 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
323 #define _SPECIAL_VARS_STR "_*@$!?#"
324 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
325 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
326 #if ENABLE_HUSH_BASH_COMPAT
327 /* Support / and // replace ops */
328 /* Note that // is stored as \ in "encoded" string representation */
329 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
330 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
331 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
333 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
334 # define VAR_SUBST_OPS "%#:-=+?"
335 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
338 #define SPECIAL_VAR_SYMBOL 3
342 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
344 /* This supports saving pointers malloced in vfork child,
345 * to be freed in the parent.
348 typedef struct nommu_save_t {
350 struct variable *old_vars;
352 char **argv_from_re_execing;
365 #if ENABLE_HUSH_LOOPS
372 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
377 /* three pseudo-keywords support contrived "case" syntax: */
378 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
379 RES_MATCH , /* "word)" */
380 RES_CASE_BODY, /* "this command is inside CASE" */
388 EXP_FLAG_GLOB = 0x200,
389 EXP_FLAG_ESC_GLOB_CHARS = 0x100,
390 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
393 typedef struct o_string {
395 int length; /* position where data is appended */
397 /* Protect newly added chars against globbing
398 * (by prepending \ to *, ?, [, \) */
400 /* At least some part of the string was inside '' or "",
401 * possibly empty one: word"", wo''rd etc. */
402 smallint has_quoted_part;
403 smallint has_empty_slot;
404 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
407 MAYBE_ASSIGNMENT = 0,
408 DEFINITELY_ASSIGNMENT = 1,
410 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
412 /* Used for initialization: o_string foo = NULL_O_STRING; */
413 #define NULL_O_STRING { NULL }
415 /* I can almost use ordinary FILE*. Is open_memstream() universally
416 * available? Where is it documented? */
417 typedef struct in_str {
419 /* eof_flag=1: last char in ->p is really an EOF */
420 char eof_flag; /* meaningless if ->p == NULL */
422 #if ENABLE_HUSH_INTERACTIVE
424 smallint promptmode; /* 0: PS1, 1: PS2 */
427 int (*get) (struct in_str *) FAST_FUNC;
428 int (*peek) (struct in_str *) FAST_FUNC;
430 #define i_getch(input) ((input)->get(input))
431 #define i_peek(input) ((input)->peek(input))
433 /* The descrip member of this structure is only used to make
434 * debugging output pretty */
435 static const struct {
437 signed char default_fd;
440 { O_RDONLY, 0, "<" },
441 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
442 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
443 { O_CREAT|O_RDWR, 1, "<>" },
444 { O_RDONLY, 0, "<<" },
445 /* Should not be needed. Bogus default_fd helps in debugging */
446 /* { O_RDONLY, 77, "<<" }, */
449 struct redir_struct {
450 struct redir_struct *next;
451 char *rd_filename; /* filename */
452 int rd_fd; /* fd to redirect */
453 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
455 smallint rd_type; /* (enum redir_type) */
456 /* note: for heredocs, rd_filename contains heredoc delimiter,
457 * and subsequently heredoc itself; and rd_dup is a bitmask:
458 * bit 0: do we need to trim leading tabs?
459 * bit 1: is heredoc quoted (<<'delim' syntax) ?
462 typedef enum redir_type {
464 REDIRECT_OVERWRITE = 1,
467 REDIRECT_HEREDOC = 4,
468 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
471 REDIRFD_SYNTAX_ERR = -2,
472 REDIRFD_TO_FILE = -1,
473 /* otherwise, rd_fd is redirected to rd_dup */
475 HEREDOC_SKIPTABS = 1,
481 pid_t pid; /* 0 if exited */
482 int assignment_cnt; /* how many argv[i] are assignments? */
483 smallint is_stopped; /* is the command currently running? */
484 smallint cmd_type; /* CMD_xxx */
486 #define CMD_SUBSHELL 1
487 #if ENABLE_HUSH_BASH_COMPAT
488 /* used for "[[ EXPR ]]" */
489 # define CMD_SINGLEWORD_NOGLOB 2
491 #if ENABLE_HUSH_FUNCTIONS
492 # define CMD_FUNCDEF 3
495 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
498 char *group_as_string;
500 #if ENABLE_HUSH_FUNCTIONS
501 struct function *child_func;
502 /* This field is used to prevent a bug here:
503 * while...do f1() {a;}; f1; f1() {b;}; f1; done
504 * When we execute "f1() {a;}" cmd, we create new function and clear
505 * cmd->group, cmd->group_as_string, cmd->argv[0].
506 * When we execute "f1() {b;}", we notice that f1 exists,
507 * and that its "parent cmd" struct is still "alive",
508 * we put those fields back into cmd->xxx
509 * (struct function has ->parent_cmd ptr to facilitate that).
510 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
511 * Without this trick, loop would execute a;b;b;b;...
512 * instead of correct sequence a;b;a;b;...
513 * When command is freed, it severs the link
514 * (sets ->child_func->parent_cmd to NULL).
517 char **argv; /* command name and arguments */
518 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
519 * and on execution these are substituted with their values.
520 * Substitution can make _several_ words out of one argv[n]!
521 * Example: argv[0]=='.^C*^C.' here: echo .$*.
522 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
524 struct redir_struct *redirects; /* I/O redirections */
526 /* Is there anything in this command at all? */
527 #define IS_NULL_CMD(cmd) \
528 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
533 int num_cmds; /* total number of commands in pipe */
534 int alive_cmds; /* number of commands running (not exited) */
535 int stopped_cmds; /* number of commands alive, but stopped */
537 int jobid; /* job number */
538 pid_t pgrp; /* process group ID for the job */
539 char *cmdtext; /* name of job */
541 struct command *cmds; /* array of commands in pipe */
542 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
543 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
544 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
546 typedef enum pipe_style {
552 /* Is there anything in this pipe at all? */
553 #define IS_NULL_PIPE(pi) \
554 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
556 /* This holds pointers to the various results of parsing */
557 struct parse_context {
558 /* linked list of pipes */
559 struct pipe *list_head;
560 /* last pipe (being constructed right now) */
562 /* last command in pipe (being constructed right now) */
563 struct command *command;
564 /* last redirect in command->redirects list */
565 struct redir_struct *pending_redirect;
571 smallint ctx_inverted; /* "! cmd | cmd" */
573 smallint ctx_dsemicolon; /* ";;" seen */
575 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
577 /* group we are enclosed in:
578 * example: "if pipe1; pipe2; then pipe3; fi"
579 * when we see "if" or "then", we malloc and copy current context,
580 * and make ->stack point to it. then we parse pipeN.
581 * when closing "then" / fi" / whatever is found,
582 * we move list_head into ->stack->command->group,
583 * copy ->stack into current context, and delete ->stack.
584 * (parsing of { list } and ( list ) doesn't use this method)
586 struct parse_context *stack;
590 /* On program start, environ points to initial environment.
591 * putenv adds new pointers into it, unsetenv removes them.
592 * Neither of these (de)allocates the strings.
593 * setenv allocates new strings in malloc space and does putenv,
594 * and thus setenv is unusable (leaky) for shell's purposes */
595 #define setenv(...) setenv_is_leaky_dont_use()
597 struct variable *next;
598 char *varstr; /* points to "name=" portion */
599 #if ENABLE_HUSH_LOCAL
600 unsigned func_nest_level;
602 int max_len; /* if > 0, name is part of initial env; else name is malloced */
603 smallint flg_export; /* putenv should be done on this var */
604 smallint flg_read_only;
612 #if ENABLE_HUSH_FUNCTIONS
614 struct function *next;
616 struct command *parent_cmd;
619 char *body_as_string;
625 /* "Globals" within this file */
626 /* Sorted roughly by size (smaller offsets == smaller code) */
628 /* interactive_fd != 0 means we are an interactive shell.
629 * If we are, then saved_tty_pgrp can also be != 0, meaning
630 * that controlling tty is available. With saved_tty_pgrp == 0,
631 * job control still works, but terminal signals
632 * (^C, ^Z, ^Y, ^\) won't work at all, and background
633 * process groups can only be created with "cmd &".
634 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
635 * to give tty to the foreground process group,
636 * and will take it back when the group is stopped (^Z)
639 #if ENABLE_HUSH_INTERACTIVE
640 /* 'interactive_fd' is a fd# open to ctty, if we have one
641 * _AND_ if we decided to act interactively */
645 # define G_interactive_fd (G.interactive_fd)
647 # define G_interactive_fd 0
649 #if ENABLE_FEATURE_EDITING
650 line_input_t *line_input_state;
655 #if ENABLE_HUSH_RANDOM_SUPPORT
661 pid_t saved_tty_pgrp;
662 struct pipe *job_list;
663 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
665 # define G_saved_tty_pgrp 0
667 smallint flag_SIGINT;
668 #if ENABLE_HUSH_LOOPS
669 smallint flag_break_continue;
671 #if ENABLE_HUSH_FUNCTIONS
672 /* 0: outside of a function (or sourced file)
673 * -1: inside of a function, ok to use return builtin
674 * 1: return is invoked, skip all till end of func
676 smallint flag_return_in_progress;
679 #if ENABLE_HUSH_MODE_X
681 # define G_x_mode (G.x_mode)
685 smallint exiting; /* used to prevent EXIT trap recursion */
686 /* These four support $?, $#, and $1 */
687 smalluint last_exitcode;
688 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
689 smalluint global_args_malloced;
690 smalluint inherited_set_is_saved;
691 /* how many non-NULL argv's we have. NB: $# + 1 */
695 char *argv0_for_re_execing;
697 #if ENABLE_HUSH_LOOPS
698 unsigned depth_break_continue;
699 unsigned depth_of_loop;
703 struct variable *top_var; /* = &G.shell_ver (set in main()) */
704 struct variable shell_ver;
705 char **expanded_assignments;
706 #if ENABLE_HUSH_FUNCTIONS
707 struct function *top_func;
708 # if ENABLE_HUSH_LOCAL
709 struct variable **shadowed_vars_pp;
710 unsigned func_nest_level;
713 /* Signal and trap handling */
715 unsigned count_SIGCHLD;
716 unsigned handled_SIGCHLD;
717 smallint we_have_children;
719 /* which signals have non-DFL handler (even with no traps set)? */
720 unsigned non_DFL_mask;
721 char **traps; /* char *traps[NSIG] */
722 sigset_t blocked_set;
723 sigset_t inherited_set;
725 unsigned long memleak_value;
728 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
730 #define G (*ptr_to_globals)
731 /* Not #defining name to G.name - this quickly gets unwieldy
732 * (too many defines). Also, I actually prefer to see when a variable
733 * is global, thus "G." prefix is a useful hint */
734 #define INIT_G() do { \
735 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
739 /* Function prototypes for builtins */
740 static int builtin_cd(char **argv) FAST_FUNC;
741 static int builtin_echo(char **argv) FAST_FUNC;
742 static int builtin_eval(char **argv) FAST_FUNC;
743 static int builtin_exec(char **argv) FAST_FUNC;
744 static int builtin_exit(char **argv) FAST_FUNC;
745 static int builtin_export(char **argv) FAST_FUNC;
747 static int builtin_fg_bg(char **argv) FAST_FUNC;
748 static int builtin_jobs(char **argv) FAST_FUNC;
751 static int builtin_help(char **argv) FAST_FUNC;
753 #if ENABLE_HUSH_LOCAL
754 static int builtin_local(char **argv) FAST_FUNC;
757 static int builtin_memleak(char **argv) FAST_FUNC;
760 static int builtin_printf(char **argv) FAST_FUNC;
762 static int builtin_pwd(char **argv) FAST_FUNC;
763 static int builtin_read(char **argv) FAST_FUNC;
764 static int builtin_set(char **argv) FAST_FUNC;
765 static int builtin_shift(char **argv) FAST_FUNC;
766 static int builtin_source(char **argv) FAST_FUNC;
767 static int builtin_test(char **argv) FAST_FUNC;
768 static int builtin_trap(char **argv) FAST_FUNC;
769 static int builtin_type(char **argv) FAST_FUNC;
770 static int builtin_true(char **argv) FAST_FUNC;
771 static int builtin_umask(char **argv) FAST_FUNC;
772 static int builtin_unset(char **argv) FAST_FUNC;
773 static int builtin_wait(char **argv) FAST_FUNC;
774 #if ENABLE_HUSH_LOOPS
775 static int builtin_break(char **argv) FAST_FUNC;
776 static int builtin_continue(char **argv) FAST_FUNC;
778 #if ENABLE_HUSH_FUNCTIONS
779 static int builtin_return(char **argv) FAST_FUNC;
782 /* Table of built-in functions. They can be forked or not, depending on
783 * context: within pipes, they fork. As simple commands, they do not.
784 * When used in non-forking context, they can change global variables
785 * in the parent shell process. If forked, of course they cannot.
786 * For example, 'unset foo | whatever' will parse and run, but foo will
787 * still be set at the end. */
788 struct built_in_command {
790 int (*b_function)(char **argv) FAST_FUNC;
793 # define BLTIN(cmd, func, help) { cmd, func, help }
795 # define BLTIN(cmd, func, help) { cmd, func }
799 static const struct built_in_command bltins1[] = {
800 BLTIN("." , builtin_source , "Run commands in a file"),
801 BLTIN(":" , builtin_true , NULL),
803 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
805 #if ENABLE_HUSH_LOOPS
806 BLTIN("break" , builtin_break , "Exit from a loop"),
808 BLTIN("cd" , builtin_cd , "Change directory"),
809 #if ENABLE_HUSH_LOOPS
810 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
812 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
813 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
814 BLTIN("exit" , builtin_exit , "Exit"),
815 BLTIN("export" , builtin_export , "Set environment variables"),
817 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
820 BLTIN("help" , builtin_help , NULL),
823 BLTIN("jobs" , builtin_jobs , "List jobs"),
825 #if ENABLE_HUSH_LOCAL
826 BLTIN("local" , builtin_local , "Set local variables"),
829 BLTIN("memleak" , builtin_memleak , NULL),
831 BLTIN("read" , builtin_read , "Input into variable"),
832 #if ENABLE_HUSH_FUNCTIONS
833 BLTIN("return" , builtin_return , "Return from a function"),
835 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
836 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
837 #if ENABLE_HUSH_BASH_COMPAT
838 BLTIN("source" , builtin_source , "Run commands in a file"),
840 BLTIN("trap" , builtin_trap , "Trap signals"),
841 BLTIN("type" , builtin_type , "Show command type"),
842 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
843 BLTIN("umask" , builtin_umask , "Set file creation mask"),
844 BLTIN("unset" , builtin_unset , "Unset variables"),
845 BLTIN("wait" , builtin_wait , "Wait for process"),
847 /* For now, echo and test are unconditionally enabled.
848 * Maybe make it configurable? */
849 static const struct built_in_command bltins2[] = {
850 BLTIN("[" , builtin_test , NULL),
851 BLTIN("echo" , builtin_echo , NULL),
853 BLTIN("printf" , builtin_printf , NULL),
855 BLTIN("pwd" , builtin_pwd , NULL),
856 BLTIN("test" , builtin_test , NULL),
863 /* prevent disasters with G.debug_indent < 0 */
864 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
865 # define debug_enter() (G.debug_indent++)
866 # define debug_leave() (G.debug_indent--)
868 # define indent() ((void)0)
869 # define debug_enter() ((void)0)
870 # define debug_leave() ((void)0)
874 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
877 #ifndef debug_printf_parse
878 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
881 #ifndef debug_printf_exec
882 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
885 #ifndef debug_printf_env
886 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
889 #ifndef debug_printf_jobs
890 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
891 # define DEBUG_JOBS 1
893 # define DEBUG_JOBS 0
896 #ifndef debug_printf_expand
897 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
898 # define DEBUG_EXPAND 1
900 # define DEBUG_EXPAND 0
903 #ifndef debug_printf_varexp
904 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
907 #ifndef debug_printf_glob
908 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
909 # define DEBUG_GLOB 1
911 # define DEBUG_GLOB 0
914 #ifndef debug_printf_list
915 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
918 #ifndef debug_printf_subst
919 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
922 #ifndef debug_printf_clean
923 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
924 # define DEBUG_CLEAN 1
926 # define DEBUG_CLEAN 0
930 static void debug_print_strings(const char *prefix, char **vv)
933 fprintf(stderr, "%s:\n", prefix);
935 fprintf(stderr, " '%s'\n", *vv++);
938 # define debug_print_strings(prefix, vv) ((void)0)
942 /* Leak hunting. Use hush_leaktool.sh for post-processing.
945 static void *xxmalloc(int lineno, size_t size)
947 void *ptr = xmalloc((size + 0xff) & ~0xff);
948 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
951 static void *xxrealloc(int lineno, void *ptr, size_t size)
953 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
954 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
957 static char *xxstrdup(int lineno, const char *str)
959 char *ptr = xstrdup(str);
960 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
963 static void xxfree(void *ptr)
965 fdprintf(2, "free %p\n", ptr);
968 # define xmalloc(s) xxmalloc(__LINE__, s)
969 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
970 # define xstrdup(s) xxstrdup(__LINE__, s)
971 # define free(p) xxfree(p)
975 /* Syntax and runtime errors. They always abort scripts.
976 * In interactive use they usually discard unparsed and/or unexecuted commands
977 * and return to the prompt.
978 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
981 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
982 # define syntax_error(lineno, msg) syntax_error(msg)
983 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
984 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
985 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
986 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
989 static void die_if_script(unsigned lineno, const char *fmt, ...)
994 bb_error_msg("hush.c:%u", lineno);
997 bb_verror_msg(fmt, p, NULL);
999 if (!G_interactive_fd)
1003 static void syntax_error(unsigned lineno, const char *msg)
1006 die_if_script(lineno, "syntax error: %s", msg);
1008 die_if_script(lineno, "syntax error", NULL);
1011 static void syntax_error_at(unsigned lineno, const char *msg)
1013 die_if_script(lineno, "syntax error at '%s'", msg);
1016 static void syntax_error_unterm_str(unsigned lineno, const char *s)
1018 die_if_script(lineno, "syntax error: unterminated %s", s);
1021 /* It so happens that all such cases are totally fatal
1022 * even if shell is interactive: EOF while looking for closing
1023 * delimiter. There is nowhere to read stuff from after that,
1024 * it's EOF! The only choice is to terminate.
1026 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
1027 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1029 char msg[2] = { ch, '\0' };
1030 syntax_error_unterm_str(lineno, msg);
1034 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
1039 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1043 # undef die_if_script
1044 # undef syntax_error
1045 # undef syntax_error_at
1046 # undef syntax_error_unterm_ch
1047 # undef syntax_error_unterm_str
1048 # undef syntax_error_unexpected_ch
1050 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1051 # define syntax_error(msg) syntax_error(__LINE__, msg)
1052 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1053 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1054 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1055 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1059 #if ENABLE_HUSH_INTERACTIVE
1060 static void cmdedit_update_prompt(void);
1062 # define cmdedit_update_prompt() ((void)0)
1066 /* Utility functions
1068 /* Replace each \x with x in place, return ptr past NUL. */
1069 static char *unbackslash(char *src)
1071 char *dst = src = strchrnul(src, '\\');
1075 if ((*dst++ = *src++) == '\0')
1081 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1102 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1103 v[count1 + count2] = NULL;
1106 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1110 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1112 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1113 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1116 #define add_strings_to_strings(strings, add, need_to_dup) \
1117 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1120 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1121 static char **add_string_to_strings(char **strings, char *add)
1126 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1129 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1131 char **ptr = add_string_to_strings(strings, add);
1132 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1135 #define add_string_to_strings(strings, add) \
1136 xx_add_string_to_strings(__LINE__, strings, add)
1139 static void free_strings(char **strings)
1154 /* Helpers for setting new $n and restoring them back
1156 typedef struct save_arg_t {
1160 smallint sv_g_malloced;
1163 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1167 sv->sv_argv0 = argv[0];
1168 sv->sv_g_argv = G.global_argv;
1169 sv->sv_g_argc = G.global_argc;
1170 sv->sv_g_malloced = G.global_args_malloced;
1172 argv[0] = G.global_argv[0]; /* retain $0 */
1173 G.global_argv = argv;
1174 G.global_args_malloced = 0;
1182 static void restore_G_args(save_arg_t *sv, char **argv)
1186 if (G.global_args_malloced) {
1187 /* someone ran "set -- arg1 arg2 ...", undo */
1189 while (*++pp) /* note: does not free $0 */
1191 free(G.global_argv);
1193 argv[0] = sv->sv_argv0;
1194 G.global_argv = sv->sv_g_argv;
1195 G.global_argc = sv->sv_g_argc;
1196 G.global_args_malloced = sv->sv_g_malloced;
1200 /* Basic theory of signal handling in shell
1201 * ========================================
1202 * This does not describe what hush does, rather, it is current understanding
1203 * what it _should_ do. If it doesn't, it's a bug.
1204 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1206 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1207 * is finished or backgrounded. It is the same in interactive and
1208 * non-interactive shells, and is the same regardless of whether
1209 * a user trap handler is installed or a shell special one is in effect.
1210 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1211 * backgrounds (i.e. stops) or kills all members of currently running
1214 * Wait builtin in interruptible by signals for which user trap is set
1215 * or by SIGINT in interactive shell.
1217 * Trap handlers will execute even within trap handlers. (right?)
1219 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1220 * except for handlers set to '' (empty string).
1222 * If job control is off, backgrounded commands ("cmd &")
1223 * have SIGINT, SIGQUIT set to SIG_IGN.
1225 * Commands which are run in command substitution ("`cmd`")
1226 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1228 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1229 * by the shell from its parent.
1231 * Signals which differ from SIG_DFL action
1232 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1235 * SIGTERM (interactive): ignore
1236 * SIGHUP (interactive):
1237 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1238 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1239 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1240 * that all pipe members are stopped. Try this in bash:
1241 * while :; do :; done - ^Z does not background it
1242 * (while :; do :; done) - ^Z backgrounds it
1243 * SIGINT (interactive): wait for last pipe, ignore the rest
1244 * of the command line, show prompt. NB: ^C does not send SIGINT
1245 * to interactive shell while shell is waiting for a pipe,
1246 * since shell is bg'ed (is not in foreground process group).
1247 * Example 1: this waits 5 sec, but does not execute ls:
1248 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1249 * Example 2: this does not wait and does not execute ls:
1250 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1251 * Example 3: this does not wait 5 sec, but executes ls:
1252 * "sleep 5; ls -l" + press ^C
1254 * (What happens to signals which are IGN on shell start?)
1255 * (What happens with signal mask on shell start?)
1257 * Implementation in hush
1258 * ======================
1259 * We use in-kernel pending signal mask to determine which signals were sent.
1260 * We block all signals which we don't want to take action immediately,
1261 * i.e. we block all signals which need to have special handling as described
1262 * above, and all signals which have traps set.
1263 * After each pipe execution, we extract any pending signals via sigtimedwait()
1266 * unsigned non_DFL_mask: a mask of such "special" signals
1267 * sigset_t blocked_set: current blocked signal set
1270 * clear bit in blocked_set unless it is also in non_DFL_mask
1271 * "trap 'cmd' SIGxxx":
1272 * set bit in blocked_set (even if 'cmd' is '')
1273 * after [v]fork, if we plan to be a shell:
1274 * unblock signals with special interactive handling
1275 * (child shell is not interactive),
1276 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1277 * after [v]fork, if we plan to exec:
1278 * POSIX says fork clears pending signal mask in child - no need to clear it.
1279 * Restore blocked signal set to one inherited by shell just prior to exec.
1281 * Note: as a result, we do not use signal handlers much. The only uses
1282 * are to count SIGCHLDs
1283 * and to restore tty pgrp on signal-induced exit.
1286 * Standard says "When a subshell is entered, traps that are not being ignored
1287 * are set to the default actions". bash interprets it so that traps which
1288 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1291 SPECIAL_INTERACTIVE_SIGS = 0
1296 SPECIAL_JOB_SIGS = 0
1304 #if ENABLE_HUSH_FAST
1305 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1308 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1314 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1315 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1316 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1317 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1319 /* Restores tty foreground process group, and exits.
1320 * May be called as signal handler for fatal signal
1321 * (will resend signal to itself, producing correct exit state)
1322 * or called directly with -EXITCODE.
1323 * We also call it if xfunc is exiting. */
1324 static void sigexit(int sig) NORETURN;
1325 static void sigexit(int sig)
1327 /* Disable all signals: job control, SIGPIPE, etc. */
1328 sigprocmask_allsigs(SIG_BLOCK);
1330 /* Careful: we can end up here after [v]fork. Do not restore
1331 * tty pgrp then, only top-level shell process does that */
1332 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1333 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1335 /* Not a signal, just exit */
1339 kill_myself_with_sig(sig); /* does not return */
1343 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1344 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1348 /* Restores tty foreground process group, and exits. */
1349 static void hush_exit(int exitcode) NORETURN;
1350 static void hush_exit(int exitcode)
1352 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1353 /* Prevent recursion:
1354 * trap "echo Hi; exit" EXIT; exit
1357 /* argv[0] is unused */
1358 argv[1] = G.traps[0];
1363 /* free(argv[1]); - why bother */
1368 sigexit(- (exitcode & 0xff));
1375 static int check_and_run_traps(int sig)
1377 /* I want it in rodata, not in bss.
1378 * gcc 4.2.1 puts it in rodata only if it has { 0, 0 }
1379 * initializer. But other compilers may still use bss.
1380 * TODO: find more portable solution.
1382 static const struct timespec zero_timespec = { 0, 0 };
1383 smalluint save_rcode;
1389 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1394 if (G.traps && G.traps[sig]) {
1395 if (G.traps[sig][0]) {
1396 /* We have user-defined handler */
1398 /* argv[0] is unused */
1399 argv[1] = G.traps[sig];
1401 save_rcode = G.last_exitcode;
1403 G.last_exitcode = save_rcode;
1404 } /* else: "" trap, ignoring signal */
1407 /* not a trap: special action */
1409 #if ENABLE_HUSH_FAST
1412 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1416 /* Builtin was ^C'ed, make it look prettier: */
1423 /* bash is observed to signal whole process groups,
1424 * not individual processes */
1425 for (job = G.job_list; job; job = job->next) {
1428 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1429 if (kill(- job->pgrp, SIGHUP) == 0)
1430 kill(- job->pgrp, SIGCONT);
1435 default: /* ignored: */
1436 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1444 static const char *get_cwd(int force)
1446 if (force || G.cwd == NULL) {
1447 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1448 * we must not try to free(bb_msg_unknown) */
1449 if (G.cwd == bb_msg_unknown)
1451 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1453 G.cwd = bb_msg_unknown;
1460 * Shell and environment variable support
1462 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1464 struct variable **pp;
1465 struct variable *cur;
1468 while ((cur = *pp) != NULL) {
1469 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1476 static const char* FAST_FUNC get_local_var_value(const char *name)
1478 struct variable **vpp;
1479 unsigned len = strlen(name);
1481 if (G.expanded_assignments) {
1482 char **cpp = G.expanded_assignments;
1485 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1486 return cp + len + 1;
1491 vpp = get_ptr_to_local_var(name, len);
1493 return (*vpp)->varstr + len + 1;
1495 if (strcmp(name, "PPID") == 0)
1496 return utoa(G.root_ppid);
1497 // bash compat: UID? EUID?
1498 #if ENABLE_HUSH_RANDOM_SUPPORT
1499 if (strcmp(name, "RANDOM") == 0)
1500 return utoa(next_random(&G.random_gen));
1505 /* str holds "NAME=VAL" and is expected to be malloced.
1506 * We take ownership of it.
1508 * 0: do not change export flag
1509 * (if creating new variable, flag will be 0)
1510 * 1: set export flag and putenv the variable
1511 * -1: clear export flag and unsetenv the variable
1512 * flg_read_only is set only when we handle -R var=val
1514 #if !BB_MMU && ENABLE_HUSH_LOCAL
1515 /* all params are used */
1516 #elif BB_MMU && ENABLE_HUSH_LOCAL
1517 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1518 set_local_var(str, flg_export, local_lvl)
1519 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1520 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1521 set_local_var(str, flg_export)
1522 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1523 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1524 set_local_var(str, flg_export, flg_read_only)
1526 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1528 struct variable **var_pp;
1529 struct variable *cur;
1533 eq_sign = strchr(str, '=');
1534 if (!eq_sign) { /* not expected to ever happen? */
1539 name_len = eq_sign - str + 1; /* including '=' */
1540 var_pp = &G.top_var;
1541 while ((cur = *var_pp) != NULL) {
1542 if (strncmp(cur->varstr, str, name_len) != 0) {
1543 var_pp = &cur->next;
1546 /* We found an existing var with this name */
1547 if (cur->flg_read_only) {
1551 bb_error_msg("%s: readonly variable", str);
1555 if (flg_export == -1) { // "&& cur->flg_export" ?
1556 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1561 #if ENABLE_HUSH_LOCAL
1562 if (cur->func_nest_level < local_lvl) {
1563 /* New variable is declared as local,
1564 * and existing one is global, or local
1565 * from enclosing function.
1566 * Remove and save old one: */
1567 *var_pp = cur->next;
1568 cur->next = *G.shadowed_vars_pp;
1569 *G.shadowed_vars_pp = cur;
1570 /* bash 3.2.33(1) and exported vars:
1572 * # f() { local z=a; env | grep ^z; }
1578 if (cur->flg_export)
1583 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1588 if (cur->max_len != 0) {
1589 if (cur->max_len >= strlen(str)) {
1590 /* This one is from startup env, reuse space */
1591 strcpy(cur->varstr, str);
1595 /* max_len == 0 signifies "malloced" var, which we can
1596 * (and has to) free */
1600 goto set_str_and_exp;
1603 /* Not found - create new variable struct */
1604 cur = xzalloc(sizeof(*cur));
1605 #if ENABLE_HUSH_LOCAL
1606 cur->func_nest_level = local_lvl;
1608 cur->next = *var_pp;
1614 cur->flg_read_only = flg_read_only;
1617 if (flg_export == 1)
1618 cur->flg_export = 1;
1619 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1620 cmdedit_update_prompt();
1621 if (cur->flg_export) {
1622 if (flg_export == -1) {
1623 cur->flg_export = 0;
1624 /* unsetenv was already done */
1626 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1627 return putenv(cur->varstr);
1633 /* Used at startup and after each cd */
1634 static void set_pwd_var(int exp)
1636 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1637 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1640 static int unset_local_var_len(const char *name, int name_len)
1642 struct variable *cur;
1643 struct variable **var_pp;
1646 return EXIT_SUCCESS;
1647 var_pp = &G.top_var;
1648 while ((cur = *var_pp) != NULL) {
1649 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1650 if (cur->flg_read_only) {
1651 bb_error_msg("%s: readonly variable", name);
1652 return EXIT_FAILURE;
1654 *var_pp = cur->next;
1655 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1656 bb_unsetenv(cur->varstr);
1657 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1658 cmdedit_update_prompt();
1662 return EXIT_SUCCESS;
1664 var_pp = &cur->next;
1666 return EXIT_SUCCESS;
1669 static int unset_local_var(const char *name)
1671 return unset_local_var_len(name, strlen(name));
1674 static void unset_vars(char **strings)
1682 const char *eq = strchrnul(*v, '=');
1683 unset_local_var_len(*v, (int)(eq - *v));
1689 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1691 char *var = xasprintf("%s=%s", name, val);
1692 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1697 * Helpers for "var1=val1 var2=val2 cmd" feature
1699 static void add_vars(struct variable *var)
1701 struct variable *next;
1705 var->next = G.top_var;
1707 if (var->flg_export) {
1708 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1709 putenv(var->varstr);
1711 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1717 static struct variable *set_vars_and_save_old(char **strings)
1720 struct variable *old = NULL;
1726 struct variable *var_p;
1727 struct variable **var_pp;
1730 eq = strchr(*s, '=');
1732 var_pp = get_ptr_to_local_var(*s, eq - *s);
1734 /* Remove variable from global linked list */
1736 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1737 *var_pp = var_p->next;
1738 /* Add it to returned list */
1742 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1753 static int FAST_FUNC static_get(struct in_str *i)
1763 static int FAST_FUNC static_peek(struct in_str *i)
1768 #if ENABLE_HUSH_INTERACTIVE
1770 static void cmdedit_update_prompt(void)
1772 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1773 G.PS1 = get_local_var_value("PS1");
1776 G.PS2 = get_local_var_value("PS2");
1784 static const char *setup_prompt_string(int promptmode)
1786 const char *prompt_str;
1787 debug_printf("setup_prompt_string %d ", promptmode);
1788 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1789 /* Set up the prompt */
1790 if (promptmode == 0) { /* PS1 */
1792 /* bash uses $PWD value, even if it is set by user.
1793 * It uses current dir only if PWD is unset.
1794 * We always use current dir. */
1795 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1800 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1801 debug_printf("result '%s'\n", prompt_str);
1805 static void get_user_input(struct in_str *i)
1808 const char *prompt_str;
1810 prompt_str = setup_prompt_string(i->promptmode);
1811 # if ENABLE_FEATURE_EDITING
1812 /* Enable command line editing only while a command line
1813 * is actually being read */
1816 /* buglet: SIGINT will not make new prompt to appear _at once_,
1817 * only after <Enter>. (^C will work) */
1818 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1819 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1820 check_and_run_traps(0);
1821 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1822 i->eof_flag = (r < 0);
1823 if (i->eof_flag) { /* EOF/error detected */
1824 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1825 G.user_input_buf[1] = '\0';
1830 fputs(prompt_str, stdout);
1832 G.user_input_buf[0] = r = fgetc(i->file);
1833 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1834 //do we need check_and_run_traps(0)? (maybe only if stdin)
1835 } while (G.flag_SIGINT);
1836 i->eof_flag = (r == EOF);
1838 i->p = G.user_input_buf;
1841 #endif /* INTERACTIVE */
1843 /* This is the magic location that prints prompts
1844 * and gets data back from the user */
1845 static int FAST_FUNC file_get(struct in_str *i)
1849 /* If there is data waiting, eat it up */
1850 if (i->p && *i->p) {
1851 #if ENABLE_HUSH_INTERACTIVE
1855 if (i->eof_flag && !*i->p)
1857 /* note: ch is never NUL */
1859 /* need to double check i->file because we might be doing something
1860 * more complicated by now, like sourcing or substituting. */
1861 #if ENABLE_HUSH_INTERACTIVE
1862 if (G_interactive_fd && i->promptme && i->file == stdin) {
1865 } while (!*i->p); /* need non-empty line */
1866 i->promptmode = 1; /* PS2 */
1871 do ch = fgetc(i->file); while (ch == '\0');
1873 debug_printf("file_get: got '%c' %d\n", ch, ch);
1874 #if ENABLE_HUSH_INTERACTIVE
1881 /* All callers guarantee this routine will never
1882 * be used right after a newline, so prompting is not needed.
1884 static int FAST_FUNC file_peek(struct in_str *i)
1887 if (i->p && *i->p) {
1888 if (i->eof_flag && !i->p[1])
1891 /* note: ch is never NUL */
1893 do ch = fgetc(i->file); while (ch == '\0');
1894 i->eof_flag = (ch == EOF);
1895 i->peek_buf[0] = ch;
1896 i->peek_buf[1] = '\0';
1898 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1902 static void setup_file_in_str(struct in_str *i, FILE *f)
1904 i->peek = file_peek;
1906 #if ENABLE_HUSH_INTERACTIVE
1908 i->promptmode = 0; /* PS1 */
1914 static void setup_string_in_str(struct in_str *i, const char *s)
1916 i->peek = static_peek;
1917 i->get = static_get;
1918 #if ENABLE_HUSH_INTERACTIVE
1920 i->promptmode = 0; /* PS1 */
1930 #define B_CHUNK (32 * sizeof(char*))
1932 static void o_reset_to_empty_unquoted(o_string *o)
1935 o->has_quoted_part = 0;
1940 static void o_free(o_string *o)
1943 memset(o, 0, sizeof(*o));
1946 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1951 static void o_grow_by(o_string *o, int len)
1953 if (o->length + len > o->maxlen) {
1954 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1955 o->data = xrealloc(o->data, 1 + o->maxlen);
1959 static void o_addchr(o_string *o, int ch)
1961 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1963 o->data[o->length] = ch;
1965 o->data[o->length] = '\0';
1968 static void o_addblock(o_string *o, const char *str, int len)
1971 memcpy(&o->data[o->length], str, len);
1973 o->data[o->length] = '\0';
1976 static void o_addstr(o_string *o, const char *str)
1978 o_addblock(o, str, strlen(str));
1982 static void nommu_addchr(o_string *o, int ch)
1988 # define nommu_addchr(o, str) ((void)0)
1991 static void o_addstr_with_NUL(o_string *o, const char *str)
1993 o_addblock(o, str, strlen(str) + 1);
1996 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
2001 if (*str++ == '\\') {
2002 /* \z -> \\\z; \<eol> -> \\<eol> */
2007 o_addchr(o, *str++);
2013 #undef HUSH_BRACE_EXP
2015 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
2016 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2017 * Apparently, on unquoted $v bash still does globbing
2018 * ("v='*.txt'; echo $v" prints all .txt files),
2019 * but NOT brace expansion! Thus, there should be TWO independent
2020 * quoting mechanisms on $v expansion side: one protects
2021 * $v from brace expansion, and other additionally protects "$v" against globbing.
2022 * We have only second one.
2025 #ifdef HUSH_BRACE_EXP
2026 # define MAYBE_BRACES "{}"
2028 # define MAYBE_BRACES ""
2031 /* My analysis of quoting semantics tells me that state information
2032 * is associated with a destination, not a source.
2034 static void o_addqchr(o_string *o, int ch)
2037 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2042 o->data[o->length] = '\\';
2045 o->data[o->length] = ch;
2047 o->data[o->length] = '\0';
2050 static void o_addQchr(o_string *o, int ch)
2053 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2054 && strchr("*?[\\" MAYBE_BRACES, ch)
2057 o->data[o->length] = '\\';
2061 o->data[o->length] = ch;
2063 o->data[o->length] = '\0';
2066 static void o_addqblock(o_string *o, const char *str, int len)
2071 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2072 if (ordinary_cnt > len) /* paranoia */
2074 o_addblock(o, str, ordinary_cnt);
2075 if (ordinary_cnt == len)
2077 str += ordinary_cnt;
2078 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2082 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2084 o->data[o->length] = '\\';
2088 o->data[o->length] = ch;
2090 o->data[o->length] = '\0';
2094 static void o_addQblock(o_string *o, const char *str, int len)
2096 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2097 o_addblock(o, str, len);
2100 o_addqblock(o, str, len);
2103 static void o_addQstr(o_string *o, const char *str)
2105 o_addQblock(o, str, strlen(str));
2108 /* A special kind of o_string for $VAR and `cmd` expansion.
2109 * It contains char* list[] at the beginning, which is grown in 16 element
2110 * increments. Actual string data starts at the next multiple of 16 * (char*).
2111 * list[i] contains an INDEX (int!) into this string data.
2112 * It means that if list[] needs to grow, data needs to be moved higher up
2113 * but list[i]'s need not be modified.
2114 * NB: remembering how many list[i]'s you have there is crucial.
2115 * o_finalize_list() operation post-processes this structure - calculates
2116 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2118 #if DEBUG_EXPAND || DEBUG_GLOB
2119 static void debug_print_list(const char *prefix, o_string *o, int n)
2121 char **list = (char**)o->data;
2122 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2126 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2127 prefix, list, n, string_start, o->length, o->maxlen,
2128 !!(o->o_expflags & EXP_FLAG_GLOB),
2130 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2133 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
2134 o->data + (int)list[i] + string_start,
2135 o->data + (int)list[i] + string_start);
2139 const char *p = o->data + (int)list[n - 1] + string_start;
2141 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2145 # define debug_print_list(prefix, o, n) ((void)0)
2148 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2149 * in list[n] so that it points past last stored byte so far.
2150 * It returns n+1. */
2151 static int o_save_ptr_helper(o_string *o, int n)
2153 char **list = (char**)o->data;
2157 if (!o->has_empty_slot) {
2158 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2159 string_len = o->length - string_start;
2160 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2161 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2162 /* list[n] points to string_start, make space for 16 more pointers */
2163 o->maxlen += 0x10 * sizeof(list[0]);
2164 o->data = xrealloc(o->data, o->maxlen + 1);
2165 list = (char**)o->data;
2166 memmove(list + n + 0x10, list + n, string_len);
2167 o->length += 0x10 * sizeof(list[0]);
2169 debug_printf_list("list[%d]=%d string_start=%d\n",
2170 n, string_len, string_start);
2173 /* We have empty slot at list[n], reuse without growth */
2174 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2175 string_len = o->length - string_start;
2176 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2177 n, string_len, string_start);
2178 o->has_empty_slot = 0;
2180 list[n] = (char*)(uintptr_t)string_len;
2184 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2185 static int o_get_last_ptr(o_string *o, int n)
2187 char **list = (char**)o->data;
2188 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2190 return ((int)(uintptr_t)list[n-1]) + string_start;
2193 #ifdef HUSH_BRACE_EXP
2194 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2195 * first, it processes even {a} (no commas), second,
2196 * I didn't manage to make it return strings when they don't match
2197 * existing files. Need to re-implement it.
2201 static int glob_needed(const char *s)
2210 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2216 /* Return pointer to next closing brace or to comma */
2217 static const char *next_brace_sub(const char *cp)
2221 while (*cp != '\0') {
2228 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2234 return *cp != '\0' ? cp : NULL;
2236 /* Recursive brace globber. Note: may garble pattern[]. */
2237 static int glob_brace(char *pattern, o_string *o, int n)
2239 char *new_pattern_buf;
2246 debug_printf_glob("glob_brace('%s')\n", pattern);
2252 if (*begin == '{') {
2253 /* Find the first sub-pattern and at the same time
2254 * find the rest after the closing brace */
2255 next = next_brace_sub(begin);
2257 /* An illegal expression */
2261 /* "{abc}" with no commas - illegal
2262 * brace expr, disregard and skip it */
2268 if (*begin == '\\' && begin[1] != '\0')
2272 debug_printf_glob("begin:%s\n", begin);
2273 debug_printf_glob("next:%s\n", next);
2275 /* Now find the end of the whole brace expression */
2277 while (*rest != '}') {
2278 rest = next_brace_sub(rest);
2280 /* An illegal expression */
2283 debug_printf_glob("rest:%s\n", rest);
2285 rest_len = strlen(++rest) + 1;
2287 /* We are sure the brace expression is well-formed */
2289 /* Allocate working buffer large enough for our work */
2290 new_pattern_buf = xmalloc(strlen(pattern));
2292 /* We have a brace expression. BEGIN points to the opening {,
2293 * NEXT points past the terminator of the first element, and REST
2294 * points past the final }. We will accumulate result names from
2295 * recursive runs for each brace alternative in the buffer using
2300 /* Construct the new glob expression */
2303 mempcpy(new_pattern_buf,
2304 /* We know the prefix for all sub-patterns */
2305 pattern, begin - pattern),
2309 /* Note: glob_brace() may garble new_pattern_buf[].
2310 * That's why we re-copy prefix every time (1st memcpy above).
2312 n = glob_brace(new_pattern_buf, o, n);
2314 /* We saw the last entry */
2318 next = next_brace_sub(next);
2320 free(new_pattern_buf);
2328 memset(&globdata, 0, sizeof(globdata));
2329 gr = glob(pattern, 0, NULL, &globdata);
2330 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2332 if (gr == GLOB_NOMATCH) {
2333 globfree(&globdata);
2334 /* NB: garbles parameter */
2335 unbackslash(pattern);
2336 o_addstr_with_NUL(o, pattern);
2337 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2338 return o_save_ptr_helper(o, n);
2340 if (gr == GLOB_NOSPACE)
2341 bb_error_msg_and_die(bb_msg_memory_exhausted);
2342 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2343 * but we didn't specify it. Paranoia again. */
2344 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2346 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2347 char **argv = globdata.gl_pathv;
2349 o_addstr_with_NUL(o, *argv);
2350 n = o_save_ptr_helper(o, n);
2356 globfree(&globdata);
2360 /* Performs globbing on last list[],
2361 * saving each result as a new list[].
2363 static int perform_glob(o_string *o, int n)
2365 char *pattern, *copy;
2367 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2369 return o_save_ptr_helper(o, n);
2370 pattern = o->data + o_get_last_ptr(o, n);
2371 debug_printf_glob("glob pattern '%s'\n", pattern);
2372 if (!glob_needed(pattern)) {
2373 /* unbackslash last string in o in place, fix length */
2374 o->length = unbackslash(pattern) - o->data;
2375 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2376 return o_save_ptr_helper(o, n);
2379 copy = xstrdup(pattern);
2380 /* "forget" pattern in o */
2381 o->length = pattern - o->data;
2382 n = glob_brace(copy, o, n);
2385 debug_print_list("perform_glob returning", o, n);
2389 #else /* !HUSH_BRACE_EXP */
2392 static int glob_needed(const char *s)
2401 if (*s == '*' || *s == '[' || *s == '?')
2407 /* Performs globbing on last list[],
2408 * saving each result as a new list[].
2410 static int perform_glob(o_string *o, int n)
2416 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2418 return o_save_ptr_helper(o, n);
2419 pattern = o->data + o_get_last_ptr(o, n);
2420 debug_printf_glob("glob pattern '%s'\n", pattern);
2421 if (!glob_needed(pattern)) {
2423 /* unbackslash last string in o in place, fix length */
2424 o->length = unbackslash(pattern) - o->data;
2425 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2426 return o_save_ptr_helper(o, n);
2429 memset(&globdata, 0, sizeof(globdata));
2430 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2431 * If we glob "*.\*" and don't find anything, we need
2432 * to fall back to using literal "*.*", but GLOB_NOCHECK
2433 * will return "*.\*"!
2435 gr = glob(pattern, 0, NULL, &globdata);
2436 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2438 if (gr == GLOB_NOMATCH) {
2439 globfree(&globdata);
2442 if (gr == GLOB_NOSPACE)
2443 bb_error_msg_and_die(bb_msg_memory_exhausted);
2444 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2445 * but we didn't specify it. Paranoia again. */
2446 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2448 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2449 char **argv = globdata.gl_pathv;
2450 /* "forget" pattern in o */
2451 o->length = pattern - o->data;
2453 o_addstr_with_NUL(o, *argv);
2454 n = o_save_ptr_helper(o, n);
2460 globfree(&globdata);
2462 debug_print_list("perform_glob returning", o, n);
2466 #endif /* !HUSH_BRACE_EXP */
2468 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2469 * Otherwise, just finish current list[] and start new */
2470 static int o_save_ptr(o_string *o, int n)
2472 if (o->o_expflags & EXP_FLAG_GLOB) {
2473 /* If o->has_empty_slot, list[n] was already globbed
2474 * (if it was requested back then when it was filled)
2475 * so don't do that again! */
2476 if (!o->has_empty_slot)
2477 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2479 return o_save_ptr_helper(o, n);
2482 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2483 static char **o_finalize_list(o_string *o, int n)
2488 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2490 debug_print_list("finalized", o, n);
2491 debug_printf_expand("finalized n:%d\n", n);
2492 list = (char**)o->data;
2493 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2497 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2502 static void free_pipe_list(struct pipe *pi);
2504 /* Returns pi->next - next pipe in the list */
2505 static struct pipe *free_pipe(struct pipe *pi)
2510 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2511 for (i = 0; i < pi->num_cmds; i++) {
2512 struct command *command;
2513 struct redir_struct *r, *rnext;
2515 command = &pi->cmds[i];
2516 debug_printf_clean(" command %d:\n", i);
2517 if (command->argv) {
2521 for (a = 0, p = command->argv; *p; a++, p++) {
2522 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2525 free_strings(command->argv);
2526 //command->argv = NULL;
2528 /* not "else if": on syntax error, we may have both! */
2529 if (command->group) {
2530 debug_printf_clean(" begin group (cmd_type:%d)\n",
2532 free_pipe_list(command->group);
2533 debug_printf_clean(" end group\n");
2534 //command->group = NULL;
2536 /* else is crucial here.
2537 * If group != NULL, child_func is meaningless */
2538 #if ENABLE_HUSH_FUNCTIONS
2539 else if (command->child_func) {
2540 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2541 command->child_func->parent_cmd = NULL;
2545 free(command->group_as_string);
2546 //command->group_as_string = NULL;
2548 for (r = command->redirects; r; r = rnext) {
2549 debug_printf_clean(" redirect %d%s",
2550 r->rd_fd, redir_table[r->rd_type].descrip);
2551 /* guard against the case >$FOO, where foo is unset or blank */
2552 if (r->rd_filename) {
2553 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2554 free(r->rd_filename);
2555 //r->rd_filename = NULL;
2557 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2561 //command->redirects = NULL;
2563 free(pi->cmds); /* children are an array, they get freed all at once */
2567 //pi->cmdtext = NULL;
2575 static void free_pipe_list(struct pipe *pi)
2579 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2581 debug_printf_clean("pipe followup code %d\n", pi->followup);
2587 /*** Parsing routines ***/
2589 static struct pipe *new_pipe(void)
2592 pi = xzalloc(sizeof(struct pipe));
2593 /*pi->followup = 0; - deliberately invalid value */
2594 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2598 /* Command (member of a pipe) is complete, or we start a new pipe
2599 * if ctx->command is NULL.
2600 * No errors possible here.
2602 static int done_command(struct parse_context *ctx)
2604 /* The command is really already in the pipe structure, so
2605 * advance the pipe counter and make a new, null command. */
2606 struct pipe *pi = ctx->pipe;
2607 struct command *command = ctx->command;
2610 if (IS_NULL_CMD(command)) {
2611 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2615 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2616 //debug_print_tree(ctx->list_head, 20);
2618 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2621 /* Only real trickiness here is that the uncommitted
2622 * command structure is not counted in pi->num_cmds. */
2623 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2624 ctx->command = command = &pi->cmds[pi->num_cmds];
2626 memset(command, 0, sizeof(*command));
2627 return pi->num_cmds; /* used only for 0/nonzero check */
2630 static void done_pipe(struct parse_context *ctx, pipe_style type)
2634 debug_printf_parse("done_pipe entered, followup %d\n", type);
2635 /* Close previous command */
2636 not_null = done_command(ctx);
2637 ctx->pipe->followup = type;
2639 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2640 ctx->ctx_inverted = 0;
2641 ctx->pipe->res_word = ctx->ctx_res_w;
2644 /* Without this check, even just <enter> on command line generates
2645 * tree of three NOPs (!). Which is harmless but annoying.
2646 * IOW: it is safe to do it unconditionally. */
2649 || ctx->ctx_res_w == RES_FI
2651 #if ENABLE_HUSH_LOOPS
2652 || ctx->ctx_res_w == RES_DONE
2653 || ctx->ctx_res_w == RES_FOR
2654 || ctx->ctx_res_w == RES_IN
2656 #if ENABLE_HUSH_CASE
2657 || ctx->ctx_res_w == RES_ESAC
2661 debug_printf_parse("done_pipe: adding new pipe: "
2662 "not_null:%d ctx->ctx_res_w:%d\n",
2663 not_null, ctx->ctx_res_w);
2665 ctx->pipe->next = new_p;
2667 /* RES_THEN, RES_DO etc are "sticky" -
2668 * they remain set for pipes inside if/while.
2669 * This is used to control execution.
2670 * RES_FOR and RES_IN are NOT sticky (needed to support
2671 * cases where variable or value happens to match a keyword):
2673 #if ENABLE_HUSH_LOOPS
2674 if (ctx->ctx_res_w == RES_FOR
2675 || ctx->ctx_res_w == RES_IN)
2676 ctx->ctx_res_w = RES_NONE;
2678 #if ENABLE_HUSH_CASE
2679 if (ctx->ctx_res_w == RES_MATCH)
2680 ctx->ctx_res_w = RES_CASE_BODY;
2681 if (ctx->ctx_res_w == RES_CASE)
2682 ctx->ctx_res_w = RES_CASE_IN;
2684 ctx->command = NULL; /* trick done_command below */
2685 /* Create the memory for command, roughly:
2686 * ctx->pipe->cmds = new struct command;
2687 * ctx->command = &ctx->pipe->cmds[0];
2690 //debug_print_tree(ctx->list_head, 10);
2692 debug_printf_parse("done_pipe return\n");
2695 static void initialize_context(struct parse_context *ctx)
2697 memset(ctx, 0, sizeof(*ctx));
2698 ctx->pipe = ctx->list_head = new_pipe();
2699 /* Create the memory for command, roughly:
2700 * ctx->pipe->cmds = new struct command;
2701 * ctx->command = &ctx->pipe->cmds[0];
2706 /* If a reserved word is found and processed, parse context is modified
2707 * and 1 is returned.
2710 struct reserved_combo {
2713 unsigned char assignment_flag;
2717 FLAG_END = (1 << RES_NONE ),
2719 FLAG_IF = (1 << RES_IF ),
2720 FLAG_THEN = (1 << RES_THEN ),
2721 FLAG_ELIF = (1 << RES_ELIF ),
2722 FLAG_ELSE = (1 << RES_ELSE ),
2723 FLAG_FI = (1 << RES_FI ),
2725 # if ENABLE_HUSH_LOOPS
2726 FLAG_FOR = (1 << RES_FOR ),
2727 FLAG_WHILE = (1 << RES_WHILE),
2728 FLAG_UNTIL = (1 << RES_UNTIL),
2729 FLAG_DO = (1 << RES_DO ),
2730 FLAG_DONE = (1 << RES_DONE ),
2731 FLAG_IN = (1 << RES_IN ),
2733 # if ENABLE_HUSH_CASE
2734 FLAG_MATCH = (1 << RES_MATCH),
2735 FLAG_ESAC = (1 << RES_ESAC ),
2737 FLAG_START = (1 << RES_XXXX ),
2740 static const struct reserved_combo* match_reserved_word(o_string *word)
2742 /* Mostly a list of accepted follow-up reserved words.
2743 * FLAG_END means we are done with the sequence, and are ready
2744 * to turn the compound list into a command.
2745 * FLAG_START means the word must start a new compound list.
2747 static const struct reserved_combo reserved_list[] = {
2749 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
2750 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
2751 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2752 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
2753 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
2754 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
2756 # if ENABLE_HUSH_LOOPS
2757 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
2758 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2759 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2760 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
2761 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
2762 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
2764 # if ENABLE_HUSH_CASE
2765 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
2766 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
2769 const struct reserved_combo *r;
2771 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2772 if (strcmp(word->data, r->literal) == 0)
2777 /* Return 0: not a keyword, 1: keyword
2779 static int reserved_word(o_string *word, struct parse_context *ctx)
2781 # if ENABLE_HUSH_CASE
2782 static const struct reserved_combo reserved_match = {
2783 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
2786 const struct reserved_combo *r;
2788 if (word->has_quoted_part)
2790 r = match_reserved_word(word);
2794 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2795 # if ENABLE_HUSH_CASE
2796 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
2797 /* "case word IN ..." - IN part starts first MATCH part */
2798 r = &reserved_match;
2801 if (r->flag == 0) { /* '!' */
2802 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
2803 syntax_error("! ! command");
2804 ctx->ctx_res_w = RES_SNTX;
2806 ctx->ctx_inverted = 1;
2809 if (r->flag & FLAG_START) {
2810 struct parse_context *old;
2812 old = xmalloc(sizeof(*old));
2813 debug_printf_parse("push stack %p\n", old);
2814 *old = *ctx; /* physical copy */
2815 initialize_context(ctx);
2817 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
2818 syntax_error_at(word->data);
2819 ctx->ctx_res_w = RES_SNTX;
2822 /* "{...} fi" is ok. "{...} if" is not
2824 * if { echo foo; } then { echo bar; } fi */
2825 if (ctx->command->group)
2826 done_pipe(ctx, PIPE_SEQ);
2829 ctx->ctx_res_w = r->res;
2830 ctx->old_flag = r->flag;
2831 word->o_assignment = r->assignment_flag;
2833 if (ctx->old_flag & FLAG_END) {
2834 struct parse_context *old;
2836 done_pipe(ctx, PIPE_SEQ);
2837 debug_printf_parse("pop stack %p\n", ctx->stack);
2839 old->command->group = ctx->list_head;
2840 old->command->cmd_type = CMD_NORMAL;
2842 o_addstr(&old->as_string, ctx->as_string.data);
2843 o_free_unsafe(&ctx->as_string);
2844 old->command->group_as_string = xstrdup(old->as_string.data);
2845 debug_printf_parse("pop, remembering as:'%s'\n",
2846 old->command->group_as_string);
2848 *ctx = *old; /* physical copy */
2853 #endif /* HAS_KEYWORDS */
2855 /* Word is complete, look at it and update parsing context.
2856 * Normal return is 0. Syntax errors return 1.
2857 * Note: on return, word is reset, but not o_free'd!
2859 static int done_word(o_string *word, struct parse_context *ctx)
2861 struct command *command = ctx->command;
2863 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
2864 if (word->length == 0 && !word->has_quoted_part) {
2865 debug_printf_parse("done_word return 0: true null, ignored\n");
2869 if (ctx->pending_redirect) {
2870 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
2871 * only if run as "bash", not "sh" */
2872 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
2874 * ...the word that follows the redirection operator
2875 * shall be subjected to tilde expansion, parameter expansion,
2876 * command substitution, arithmetic expansion, and quote
2877 * removal. Pathname expansion shall not be performed
2878 * on the word by a non-interactive shell; an interactive
2879 * shell may perform it, but shall do so only when
2880 * the expansion would result in one word."
2882 ctx->pending_redirect->rd_filename = xstrdup(word->data);
2883 /* Cater for >\file case:
2884 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
2885 * Same with heredocs:
2886 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
2888 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
2889 unbackslash(ctx->pending_redirect->rd_filename);
2890 /* Is it <<"HEREDOC"? */
2891 if (word->has_quoted_part) {
2892 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
2895 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
2896 ctx->pending_redirect = NULL;
2898 /* If this word wasn't an assignment, next ones definitely
2899 * can't be assignments. Even if they look like ones. */
2900 if (word->o_assignment != DEFINITELY_ASSIGNMENT
2901 && word->o_assignment != WORD_IS_KEYWORD
2903 word->o_assignment = NOT_ASSIGNMENT;
2905 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
2906 command->assignment_cnt++;
2907 word->o_assignment = MAYBE_ASSIGNMENT;
2911 # if ENABLE_HUSH_CASE
2912 if (ctx->ctx_dsemicolon
2913 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
2915 /* already done when ctx_dsemicolon was set to 1: */
2916 /* ctx->ctx_res_w = RES_MATCH; */
2917 ctx->ctx_dsemicolon = 0;
2920 if (!command->argv /* if it's the first word... */
2921 # if ENABLE_HUSH_LOOPS
2922 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
2923 && ctx->ctx_res_w != RES_IN
2925 # if ENABLE_HUSH_CASE
2926 && ctx->ctx_res_w != RES_CASE
2929 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
2930 if (reserved_word(word, ctx)) {
2931 o_reset_to_empty_unquoted(word);
2932 debug_printf_parse("done_word return %d\n",
2933 (ctx->ctx_res_w == RES_SNTX));
2934 return (ctx->ctx_res_w == RES_SNTX);
2936 # if ENABLE_HUSH_BASH_COMPAT
2937 if (strcmp(word->data, "[[") == 0) {
2938 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
2944 if (command->group) {
2945 /* "{ echo foo; } echo bar" - bad */
2946 syntax_error_at(word->data);
2947 debug_printf_parse("done_word return 1: syntax error, "
2948 "groups and arglists don't mix\n");
2951 if (word->has_quoted_part
2952 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
2953 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
2954 /* (otherwise it's known to be not empty and is already safe) */
2956 /* exclude "$@" - it can expand to no word despite "" */
2957 char *p = word->data;
2958 while (p[0] == SPECIAL_VAR_SYMBOL
2959 && (p[1] & 0x7f) == '@'
2960 && p[2] == SPECIAL_VAR_SYMBOL
2964 if (p == word->data || p[0] != '\0') {
2965 /* saw no "$@", or not only "$@" but some
2966 * real text is there too */
2967 /* insert "empty variable" reference, this makes
2968 * e.g. "", $empty"" etc to not disappear */
2969 o_addchr(word, SPECIAL_VAR_SYMBOL);
2970 o_addchr(word, SPECIAL_VAR_SYMBOL);
2973 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
2974 debug_print_strings("word appended to argv", command->argv);
2977 #if ENABLE_HUSH_LOOPS
2978 if (ctx->ctx_res_w == RES_FOR) {
2979 if (word->has_quoted_part
2980 || !is_well_formed_var_name(command->argv[0], '\0')
2982 /* bash says just "not a valid identifier" */
2983 syntax_error("not a valid identifier in for");
2986 /* Force FOR to have just one word (variable name) */
2987 /* NB: basically, this makes hush see "for v in ..."
2988 * syntax as if it is "for v; in ...". FOR and IN become
2989 * two pipe structs in parse tree. */
2990 done_pipe(ctx, PIPE_SEQ);
2993 #if ENABLE_HUSH_CASE
2994 /* Force CASE to have just one word */
2995 if (ctx->ctx_res_w == RES_CASE) {
2996 done_pipe(ctx, PIPE_SEQ);
3000 o_reset_to_empty_unquoted(word);
3002 debug_printf_parse("done_word return 0\n");
3007 /* Peek ahead in the input to find out if we have a "&n" construct,
3008 * as in "2>&1", that represents duplicating a file descriptor.
3010 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3011 * REDIRFD_SYNTAX_ERR if syntax error,
3012 * REDIRFD_TO_FILE if no & was seen,
3013 * or the number found.
3016 #define parse_redir_right_fd(as_string, input) \
3017 parse_redir_right_fd(input)
3019 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3025 return REDIRFD_TO_FILE;
3027 ch = i_getch(input); /* get the & */
3028 nommu_addchr(as_string, ch);
3031 ch = i_getch(input);
3032 nommu_addchr(as_string, ch);
3033 return REDIRFD_CLOSE;
3037 while (ch != EOF && isdigit(ch)) {
3038 d = d*10 + (ch-'0');
3040 ch = i_getch(input);
3041 nommu_addchr(as_string, ch);
3046 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3048 bb_error_msg("ambiguous redirect");
3049 return REDIRFD_SYNTAX_ERR;
3052 /* Return code is 0 normal, 1 if a syntax error is detected
3054 static int parse_redirect(struct parse_context *ctx,
3057 struct in_str *input)
3059 struct command *command = ctx->command;
3060 struct redir_struct *redir;
3061 struct redir_struct **redirp;
3064 dup_num = REDIRFD_TO_FILE;
3065 if (style != REDIRECT_HEREDOC) {
3066 /* Check for a '>&1' type redirect */
3067 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3068 if (dup_num == REDIRFD_SYNTAX_ERR)
3071 int ch = i_peek(input);
3072 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3073 if (dup_num) { /* <<-... */
3074 ch = i_getch(input);
3075 nommu_addchr(&ctx->as_string, ch);
3080 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3081 int ch = i_peek(input);
3083 /* >|FILE redirect ("clobbering" >).
3084 * Since we do not support "set -o noclobber" yet,
3085 * >| and > are the same for now. Just eat |.
3087 ch = i_getch(input);
3088 nommu_addchr(&ctx->as_string, ch);
3092 /* Create a new redir_struct and append it to the linked list */
3093 redirp = &command->redirects;
3094 while ((redir = *redirp) != NULL) {
3095 redirp = &(redir->next);
3097 *redirp = redir = xzalloc(sizeof(*redir));
3098 /* redir->next = NULL; */
3099 /* redir->rd_filename = NULL; */
3100 redir->rd_type = style;
3101 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3103 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3104 redir_table[style].descrip);
3106 redir->rd_dup = dup_num;
3107 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3108 /* Erik had a check here that the file descriptor in question
3109 * is legit; I postpone that to "run time"
3110 * A "-" representation of "close me" shows up as a -3 here */
3111 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3112 redir->rd_fd, redir->rd_dup);
3114 /* Set ctx->pending_redirect, so we know what to do at the
3115 * end of the next parsed word. */
3116 ctx->pending_redirect = redir;
3121 /* If a redirect is immediately preceded by a number, that number is
3122 * supposed to tell which file descriptor to redirect. This routine
3123 * looks for such preceding numbers. In an ideal world this routine
3124 * needs to handle all the following classes of redirects...
3125 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3126 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3127 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3128 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3130 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3132 * ... If n is quoted, the number shall not be recognized as part of
3133 * the redirection expression. For example:
3135 * writes the character 2 into file a"
3136 * We are getting it right by setting ->has_quoted_part on any \<char>
3138 * A -1 return means no valid number was found,
3139 * the caller should use the appropriate default for this redirection.
3141 static int redirect_opt_num(o_string *o)
3145 if (o->data == NULL)
3147 num = bb_strtou(o->data, NULL, 10);
3148 if (errno || num < 0)
3150 o_reset_to_empty_unquoted(o);
3155 #define fetch_till_str(as_string, input, word, skip_tabs) \
3156 fetch_till_str(input, word, skip_tabs)
3158 static char *fetch_till_str(o_string *as_string,
3159 struct in_str *input,
3163 o_string heredoc = NULL_O_STRING;
3165 int prev = 0; /* not \ */
3170 ch = i_getch(input);
3172 nommu_addchr(as_string, ch);
3173 if ((ch == '\n' || ch == EOF)
3174 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3176 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3177 heredoc.data[past_EOL] = '\0';
3178 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3179 return heredoc.data;
3181 while (ch == '\n') {
3182 o_addchr(&heredoc, ch);
3185 past_EOL = heredoc.length;
3187 ch = i_getch(input);
3189 nommu_addchr(as_string, ch);
3190 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3194 o_free_unsafe(&heredoc);
3197 o_addchr(&heredoc, ch);
3198 nommu_addchr(as_string, ch);
3199 if (prev == '\\' && ch == '\\')
3200 /* Correctly handle foo\\<eol> (not a line cont.) */
3201 prev = 0; /* not \ */
3207 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3208 * and load them all. There should be exactly heredoc_cnt of them.
3210 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3212 struct pipe *pi = ctx->list_head;
3214 while (pi && heredoc_cnt) {
3216 struct command *cmd = pi->cmds;
3218 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3220 cmd->argv ? cmd->argv[0] : "NONE");
3221 for (i = 0; i < pi->num_cmds; i++) {
3222 struct redir_struct *redir = cmd->redirects;
3224 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3225 i, cmd->argv ? cmd->argv[0] : "NONE");
3227 if (redir->rd_type == REDIRECT_HEREDOC) {
3230 redir->rd_type = REDIRECT_HEREDOC2;
3231 /* redir->rd_dup is (ab)used to indicate <<- */
3232 p = fetch_till_str(&ctx->as_string, input,
3233 redir->rd_filename, redir->rd_dup);
3235 syntax_error("unexpected EOF in here document");
3238 free(redir->rd_filename);
3239 redir->rd_filename = p;
3242 redir = redir->next;
3249 /* Should be 0. If it isn't, it's a parse error */
3251 bb_error_msg_and_die("heredoc BUG 2");
3257 static int run_list(struct pipe *pi);
3259 #define parse_stream(pstring, input, end_trigger) \
3260 parse_stream(input, end_trigger)
3262 static struct pipe *parse_stream(char **pstring,
3263 struct in_str *input,
3267 #if !ENABLE_HUSH_FUNCTIONS
3268 #define parse_group(dest, ctx, input, ch) \
3269 parse_group(ctx, input, ch)
3271 static int parse_group(o_string *dest, struct parse_context *ctx,
3272 struct in_str *input, int ch)
3274 /* dest contains characters seen prior to ( or {.
3275 * Typically it's empty, but for function defs,
3276 * it contains function name (without '()'). */
3277 struct pipe *pipe_list;
3279 struct command *command = ctx->command;
3281 debug_printf_parse("parse_group entered\n");
3282 #if ENABLE_HUSH_FUNCTIONS
3283 if (ch == '(' && !dest->has_quoted_part) {
3285 if (done_word(dest, ctx))
3288 goto skip; /* (... */
3289 if (command->argv[1]) { /* word word ... (... */
3290 syntax_error_unexpected_ch('(');
3293 /* it is "word(..." or "word (..." */
3295 ch = i_getch(input);
3296 while (ch == ' ' || ch == '\t');
3298 syntax_error_unexpected_ch(ch);
3301 nommu_addchr(&ctx->as_string, ch);
3303 ch = i_getch(input);
3304 while (ch == ' ' || ch == '\t' || ch == '\n');
3306 syntax_error_unexpected_ch(ch);
3309 nommu_addchr(&ctx->as_string, ch);
3310 command->cmd_type = CMD_FUNCDEF;
3315 #if 0 /* Prevented by caller */
3316 if (command->argv /* word [word]{... */
3317 || dest->length /* word{... */
3318 || dest->has_quoted_part /* ""{... */
3321 debug_printf_parse("parse_group return 1: "
3322 "syntax error, groups and arglists don't mix\n");
3327 #if ENABLE_HUSH_FUNCTIONS
3333 command->cmd_type = CMD_SUBSHELL;
3335 /* bash does not allow "{echo...", requires whitespace */
3336 ch = i_getch(input);
3337 if (ch != ' ' && ch != '\t' && ch != '\n') {
3338 syntax_error_unexpected_ch(ch);
3341 nommu_addchr(&ctx->as_string, ch);
3346 # define as_string NULL
3348 char *as_string = NULL;
3350 pipe_list = parse_stream(&as_string, input, endch);
3353 o_addstr(&ctx->as_string, as_string);
3355 /* empty ()/{} or parse error? */
3356 if (!pipe_list || pipe_list == ERR_PTR) {
3357 /* parse_stream already emitted error msg */
3360 debug_printf_parse("parse_group return 1: "
3361 "parse_stream returned %p\n", pipe_list);
3364 command->group = pipe_list;
3366 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3367 command->group_as_string = as_string;
3368 debug_printf_parse("end of group, remembering as:'%s'\n",
3369 command->group_as_string);
3373 debug_printf_parse("parse_group return 0\n");
3375 /* command remains "open", available for possible redirects */
3378 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3379 /* Subroutines for copying $(...) and `...` things */
3380 static void add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3382 static void add_till_single_quote(o_string *dest, struct in_str *input)
3385 int ch = i_getch(input);
3387 syntax_error_unterm_ch('\'');
3388 /*xfunc_die(); - redundant */
3395 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3396 static void add_till_double_quote(o_string *dest, struct in_str *input)
3399 int ch = i_getch(input);
3401 syntax_error_unterm_ch('"');
3402 /*xfunc_die(); - redundant */
3406 if (ch == '\\') { /* \x. Copy both chars. */
3408 ch = i_getch(input);
3412 add_till_backquote(dest, input, /*in_dquote:*/ 1);
3416 //if (ch == '$') ...
3419 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3421 * "Within the backquoted style of command substitution, backslash
3422 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3423 * The search for the matching backquote shall be satisfied by the first
3424 * backquote found without a preceding backslash; during this search,
3425 * if a non-escaped backquote is encountered within a shell comment,
3426 * a here-document, an embedded command substitution of the $(command)
3427 * form, or a quoted string, undefined results occur. A single-quoted
3428 * or double-quoted string that begins, but does not end, within the
3429 * "`...`" sequence produces undefined results."
3431 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3433 static void add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3436 int ch = i_getch(input);
3440 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3441 ch = i_getch(input);
3445 && (!in_dquote || ch != '"')
3447 o_addchr(dest, '\\');
3451 syntax_error_unterm_ch('`');
3452 /*xfunc_die(); - redundant */
3457 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3458 * quoting and nested ()s.
3459 * "With the $(command) style of command substitution, all characters
3460 * following the open parenthesis to the matching closing parenthesis
3461 * constitute the command. Any valid shell script can be used for command,
3462 * except a script consisting solely of redirections which produces
3463 * unspecified results."
3465 * echo $(echo '(TEST)' BEST) (TEST) BEST
3466 * echo $(echo 'TEST)' BEST) TEST) BEST
3467 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3469 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3470 * can contain arbitrary constructs, just like $(cmd).
3471 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3472 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3474 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3475 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3478 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3479 # if ENABLE_HUSH_BASH_COMPAT
3480 char end_char2 = end_ch >> 8;
3482 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3485 ch = i_getch(input);
3487 syntax_error_unterm_ch(end_ch);
3488 /*xfunc_die(); - redundant */
3490 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3493 /* we look for closing )) of $((EXPR)) */
3494 if (i_peek(input) == end_ch) {
3495 i_getch(input); /* eat second ')' */
3500 if (ch == '(' || ch == '{') {
3501 ch = (ch == '(' ? ')' : '}');
3502 add_till_closing_bracket(dest, input, ch);
3507 add_till_single_quote(dest, input);
3512 add_till_double_quote(dest, input);
3517 add_till_backquote(dest, input, /*in_dquote:*/ 0);
3522 /* \x. Copy verbatim. Important for \(, \) */
3523 ch = i_getch(input);
3525 syntax_error_unterm_ch(')');
3526 /*xfunc_die(); - redundant */
3534 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3536 /* Return code: 0 for OK, 1 for syntax error */
3538 #define parse_dollar(as_string, dest, input, quote_mask) \
3539 parse_dollar(dest, input, quote_mask)
3540 #define as_string NULL
3542 static int parse_dollar(o_string *as_string,
3544 struct in_str *input, unsigned char quote_mask)
3546 int ch = i_peek(input); /* first character after the $ */
3548 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3550 ch = i_getch(input);
3551 nommu_addchr(as_string, ch);
3553 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3555 debug_printf_parse(": '%c'\n", ch);
3556 o_addchr(dest, ch | quote_mask);
3559 if (!isalnum(ch) && ch != '_')
3561 ch = i_getch(input);
3562 nommu_addchr(as_string, ch);
3564 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3565 } else if (isdigit(ch)) {
3567 ch = i_getch(input);
3568 nommu_addchr(as_string, ch);
3569 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3570 debug_printf_parse(": '%c'\n", ch);
3571 o_addchr(dest, ch | quote_mask);
3572 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3573 } else switch (ch) {
3575 case '!': /* last bg pid */
3576 case '?': /* last exit code */
3577 case '#': /* number of args */
3578 case '*': /* args */
3579 case '@': /* args */
3580 goto make_one_char_var;
3582 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3584 ch = i_getch(input); /* eat '{' */
3585 nommu_addchr(as_string, ch);
3587 ch = i_getch(input); /* first char after '{' */
3588 /* It should be ${?}, or ${#var},
3589 * or even ${?+subst} - operator acting on a special variable,
3590 * or the beginning of variable name.
3593 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3596 syntax_error_unterm_str("${name}");
3597 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
3600 nommu_addchr(as_string, ch);
3603 /* It's possible to just call add_till_closing_bracket() at this point.
3604 * However, this regresses some of our testsuite cases
3605 * which check invalid constructs like ${%}.
3606 * Oh well... let's check that the var name part is fine... */
3612 debug_printf_parse(": '%c'\n", ch);
3614 ch = i_getch(input);
3615 nommu_addchr(as_string, ch);
3619 if (!isalnum(ch) && ch != '_') {
3621 unsigned char last_ch;
3622 /* handle parameter expansions
3623 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3625 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3626 goto bad_dollar_syntax;
3628 /* Eat everything until closing '}' (or ':') */
3630 if (ENABLE_HUSH_BASH_COMPAT
3632 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3634 /* It's ${var:N[:M]} thing */
3635 end_ch = '}' * 0x100 + ':';
3637 if (ENABLE_HUSH_BASH_COMPAT
3640 /* It's ${var/[/]pattern[/repl]} thing */
3641 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3643 nommu_addchr(as_string, '/');
3646 end_ch = '}' * 0x100 + '/';
3652 #if ENABLE_HUSH_DOLLAR_OPS
3653 last_ch = add_till_closing_bracket(dest, input, end_ch);
3655 #error Simple code to only allow ${var} is not implemented
3658 o_addstr(as_string, dest->data + pos);
3659 o_addchr(as_string, last_ch);
3662 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3663 /* close the first block: */
3664 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3665 /* while parsing N from ${var:N[:M]}
3666 * or pattern from ${var/[/]pattern[/repl]} */
3667 if ((end_ch & 0xff) == last_ch) {
3668 /* got ':' or '/'- parse the rest */
3673 if (end_ch == '}' * 0x100 + ':') {
3674 /* it's ${var:N} - emulate :999999999 */
3675 o_addstr(dest, "999999999");
3676 } /* else: it's ${var/[/]pattern} */
3681 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3684 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3688 ch = i_getch(input);
3689 nommu_addchr(as_string, ch);
3690 # if ENABLE_SH_MATH_SUPPORT
3691 if (i_peek(input) == '(') {
3692 ch = i_getch(input);
3693 nommu_addchr(as_string, ch);
3694 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3695 o_addchr(dest, /*quote_mask |*/ '+');
3698 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
3700 o_addstr(as_string, dest->data + pos);
3701 o_addchr(as_string, ')');
3702 o_addchr(as_string, ')');
3704 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3708 # if ENABLE_HUSH_TICK
3709 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3710 o_addchr(dest, quote_mask | '`');
3713 add_till_closing_bracket(dest, input, ')');
3715 o_addstr(as_string, dest->data + pos);
3716 o_addchr(as_string, ')');
3718 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3724 ch = i_getch(input);
3725 nommu_addchr(as_string, ch);
3727 if (isalnum(ch)) { /* it's $_name or $_123 */
3732 /* TODO: $_ and $-: */
3733 /* $_ Shell or shell script name; or last argument of last command
3734 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
3735 * but in command's env, set to full pathname used to invoke it */
3736 /* $- Option flags set by set builtin or shell options (-i etc) */
3738 o_addQchr(dest, '$');
3740 debug_printf_parse("parse_dollar return 0\n");
3746 # if ENABLE_HUSH_BASH_COMPAT
3747 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3748 encode_string(dest, input, dquote_end, process_bkslash)
3750 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
3751 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3752 encode_string(dest, input, dquote_end)
3754 #define as_string NULL
3758 # if ENABLE_HUSH_BASH_COMPAT
3759 /* all parameters are needed, no macro tricks */
3761 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3762 encode_string(as_string, dest, input, dquote_end)
3765 static int encode_string(o_string *as_string,
3767 struct in_str *input,
3769 int process_bkslash)
3771 #if !ENABLE_HUSH_BASH_COMPAT
3772 const int process_bkslash = 1;
3778 ch = i_getch(input);
3780 nommu_addchr(as_string, ch);
3781 if (ch == dquote_end) { /* may be only '"' or EOF */
3782 debug_printf_parse("encode_string return 0\n");
3785 /* note: can't move it above ch == dquote_end check! */
3787 syntax_error_unterm_ch('"');
3788 /*xfunc_die(); - redundant */
3792 next = i_peek(input);
3794 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
3795 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3796 if (process_bkslash && ch == '\\') {
3798 syntax_error("\\<eof>");
3802 * "The backslash retains its special meaning [in "..."]
3803 * only when followed by one of the following characters:
3804 * $, `, ", \, or <newline>. A double quote may be quoted
3805 * within double quotes by preceding it with a backslash."
3806 * NB: in (unquoted) heredoc, above does not apply to ",
3807 * therefore we check for it by "next == dquote_end" cond.
3809 if (next == dquote_end || strchr("$`\\\n", next)) {
3810 ch = i_getch(input); /* eat next */
3812 goto again; /* skip \<newline> */
3813 } /* else: ch remains == '\\', and we double it below: */
3814 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
3815 nommu_addchr(as_string, ch);
3819 if (parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80) != 0) {
3820 debug_printf_parse("encode_string return 1: "
3821 "parse_dollar returned non-0\n");
3826 #if ENABLE_HUSH_TICK
3828 //unsigned pos = dest->length;
3829 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3830 o_addchr(dest, 0x80 | '`');
3831 add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"');
3832 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3833 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3837 o_addQchr(dest, ch);
3843 * Scan input until EOF or end_trigger char.
3844 * Return a list of pipes to execute, or NULL on EOF
3845 * or if end_trigger character is met.
3846 * On syntax error, exit is shell is not interactive,
3847 * reset parsing machinery and start parsing anew,
3848 * or return ERR_PTR.
3850 static struct pipe *parse_stream(char **pstring,
3851 struct in_str *input,
3854 struct parse_context ctx;
3855 o_string dest = NULL_O_STRING;
3858 /* Single-quote triggers a bypass of the main loop until its mate is
3859 * found. When recursing, quote state is passed in via dest->o_expflags.
3861 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
3862 end_trigger ? end_trigger : 'X');
3865 /* If very first arg is "" or '', dest.data may end up NULL.
3866 * Preventing this: */
3867 o_addchr(&dest, '\0');
3870 /* We used to separate words on $IFS here. This was wrong.
3871 * $IFS is used only for word splitting when $var is expanded,
3872 * here we should use blank chars as separators, not $IFS
3875 reset: /* we come back here only on syntax errors in interactive shell */
3877 #if ENABLE_HUSH_INTERACTIVE
3878 input->promptmode = 0; /* PS1 */
3880 if (MAYBE_ASSIGNMENT != 0)
3881 dest.o_assignment = MAYBE_ASSIGNMENT;
3882 initialize_context(&ctx);
3885 const char *is_blank;
3886 const char *is_special;
3890 redir_type redir_style;
3892 ch = i_getch(input);
3893 debug_printf_parse(": ch=%c (%d) escape=%d\n",
3894 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3899 syntax_error_unterm_str("here document");
3902 /* end_trigger == '}' case errors out earlier,
3903 * checking only ')' */
3904 if (end_trigger == ')') {
3905 syntax_error_unterm_ch('('); /* exits */
3906 /* goto parse_error; */
3909 if (done_word(&dest, &ctx)) {
3913 done_pipe(&ctx, PIPE_SEQ);
3915 /* If we got nothing... */
3916 /* (this makes bare "&" cmd a no-op.
3917 * bash says: "syntax error near unexpected token '&'") */
3918 if (pi->num_cmds == 0
3919 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
3925 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
3927 *pstring = ctx.as_string.data;
3929 o_free_unsafe(&ctx.as_string);
3932 debug_printf_parse("parse_stream return %p\n", pi);
3935 nommu_addchr(&ctx.as_string, ch);
3939 next = i_peek(input);
3941 is_special = "{}<>;&|()#'" /* special outside of "str" */
3942 "\\$\"" IF_HUSH_TICK("`"); /* always special */
3943 /* Are { and } special here? */
3944 if (ctx.command->argv /* word [word]{... - non-special */
3945 || dest.length /* word{... - non-special */
3946 || dest.has_quoted_part /* ""{... - non-special */
3947 || (next != ';' /* }; - special */
3948 && next != ')' /* }) - special */
3949 && next != '&' /* }& and }&& ... - special */
3950 && next != '|' /* }|| ... - special */
3951 && !strchr(defifs, next) /* {word - non-special */
3954 /* They are not special, skip "{}" */
3957 is_special = strchr(is_special, ch);
3958 is_blank = strchr(defifs, ch);
3960 if (!is_special && !is_blank) { /* ordinary char */
3962 o_addQchr(&dest, ch);
3963 if ((dest.o_assignment == MAYBE_ASSIGNMENT
3964 || dest.o_assignment == WORD_IS_KEYWORD)
3966 && is_well_formed_var_name(dest.data, '=')
3968 dest.o_assignment = DEFINITELY_ASSIGNMENT;
3974 if (done_word(&dest, &ctx)) {
3978 #if ENABLE_HUSH_CASE
3979 /* "case ... in <newline> word) ..." -
3980 * newlines are ignored (but ';' wouldn't be) */
3981 if (ctx.command->argv == NULL
3982 && ctx.ctx_res_w == RES_MATCH
3987 /* Treat newline as a command separator. */
3988 done_pipe(&ctx, PIPE_SEQ);
3989 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
3991 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
3996 dest.o_assignment = MAYBE_ASSIGNMENT;
3998 /* note: if (is_blank) continue;
3999 * will still trigger for us */
4003 /* "cmd}" or "cmd }..." without semicolon or &:
4004 * } is an ordinary char in this case, even inside { cmd; }
4005 * Pathological example: { ""}; } should exec "}" cmd
4008 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4009 || dest.length != 0 /* word} */
4010 || dest.has_quoted_part /* ""} */
4014 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4015 goto skip_end_trigger;
4016 /* else: } does terminate a group */
4019 if (end_trigger && end_trigger == ch
4020 && (ch != ';' || heredoc_cnt == 0)
4021 #if ENABLE_HUSH_CASE
4023 || ctx.ctx_res_w != RES_MATCH
4024 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4029 /* This is technically valid:
4030 * { cat <<HERE; }; echo Ok
4034 * but we don't support this.
4035 * We require heredoc to be in enclosing {}/(),
4038 syntax_error_unterm_str("here document");
4041 if (done_word(&dest, &ctx)) {
4044 done_pipe(&ctx, PIPE_SEQ);
4045 dest.o_assignment = MAYBE_ASSIGNMENT;
4046 /* Do we sit outside of any if's, loops or case's? */
4048 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4052 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4054 *pstring = ctx.as_string.data;
4056 o_free_unsafe(&ctx.as_string);
4059 debug_printf_parse("parse_stream return %p: "
4060 "end_trigger char found\n",
4062 return ctx.list_head;
4069 /* Catch <, > before deciding whether this word is
4070 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4073 redir_fd = redirect_opt_num(&dest);
4074 if (done_word(&dest, &ctx)) {
4077 redir_style = REDIRECT_OVERWRITE;
4079 redir_style = REDIRECT_APPEND;
4080 ch = i_getch(input);
4081 nommu_addchr(&ctx.as_string, ch);
4084 else if (next == '(') {
4085 syntax_error(">(process) not supported");
4089 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4091 continue; /* back to top of while (1) */
4093 redir_fd = redirect_opt_num(&dest);
4094 if (done_word(&dest, &ctx)) {
4097 redir_style = REDIRECT_INPUT;
4099 redir_style = REDIRECT_HEREDOC;
4101 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4102 ch = i_getch(input);
4103 nommu_addchr(&ctx.as_string, ch);
4104 } else if (next == '>') {
4105 redir_style = REDIRECT_IO;
4106 ch = i_getch(input);
4107 nommu_addchr(&ctx.as_string, ch);
4110 else if (next == '(') {
4111 syntax_error("<(process) not supported");
4115 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4117 continue; /* back to top of while (1) */
4120 if (dest.o_assignment == MAYBE_ASSIGNMENT
4121 /* check that we are not in word in "a=1 2>word b=1": */
4122 && !ctx.pending_redirect
4124 /* ch is a special char and thus this word
4125 * cannot be an assignment */
4126 dest.o_assignment = NOT_ASSIGNMENT;
4129 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4133 if (dest.length == 0) {
4136 if (ch == EOF || ch == '\n')
4139 /* note: we do not add it to &ctx.as_string */
4141 nommu_addchr(&ctx.as_string, '\n');
4143 o_addQchr(&dest, ch);
4148 syntax_error("\\<eof>");
4151 ch = i_getch(input);
4153 o_addchr(&dest, '\\');
4154 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4155 o_addchr(&dest, ch);
4156 nommu_addchr(&ctx.as_string, ch);
4157 /* Example: echo Hello \2>file
4158 * we need to know that word 2 is quoted */
4159 dest.has_quoted_part = 1;
4163 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
4164 ctx.as_string.data[--ctx.as_string.length] = '\0';
4169 if (parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0) != 0) {
4170 debug_printf_parse("parse_stream parse error: "
4171 "parse_dollar returned non-0\n");
4176 dest.has_quoted_part = 1;
4178 ch = i_getch(input);
4180 syntax_error_unterm_ch('\'');
4181 /*xfunc_die(); - redundant */
4183 nommu_addchr(&ctx.as_string, ch);
4186 o_addqchr(&dest, ch);
4190 dest.has_quoted_part = 1;
4191 if (dest.o_assignment == NOT_ASSIGNMENT)
4192 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4193 if (encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4195 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4197 #if ENABLE_HUSH_TICK
4201 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4202 o_addchr(&dest, '`');
4204 add_till_backquote(&dest, input, /*in_dquote:*/ 0);
4206 o_addstr(&ctx.as_string, dest.data + pos);
4207 o_addchr(&ctx.as_string, '`');
4209 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4210 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4215 #if ENABLE_HUSH_CASE
4218 if (done_word(&dest, &ctx)) {
4221 done_pipe(&ctx, PIPE_SEQ);
4222 #if ENABLE_HUSH_CASE
4223 /* Eat multiple semicolons, detect
4224 * whether it means something special */
4229 ch = i_getch(input);
4230 nommu_addchr(&ctx.as_string, ch);
4231 if (ctx.ctx_res_w == RES_CASE_BODY) {
4232 ctx.ctx_dsemicolon = 1;
4233 ctx.ctx_res_w = RES_MATCH;
4239 /* We just finished a cmd. New one may start
4240 * with an assignment */
4241 dest.o_assignment = MAYBE_ASSIGNMENT;
4244 if (done_word(&dest, &ctx)) {
4248 ch = i_getch(input);
4249 nommu_addchr(&ctx.as_string, ch);
4250 done_pipe(&ctx, PIPE_AND);
4252 done_pipe(&ctx, PIPE_BG);
4256 if (done_word(&dest, &ctx)) {
4259 #if ENABLE_HUSH_CASE
4260 if (ctx.ctx_res_w == RES_MATCH)
4261 break; /* we are in case's "word | word)" */
4263 if (next == '|') { /* || */
4264 ch = i_getch(input);
4265 nommu_addchr(&ctx.as_string, ch);
4266 done_pipe(&ctx, PIPE_OR);
4268 /* we could pick up a file descriptor choice here
4269 * with redirect_opt_num(), but bash doesn't do it.
4270 * "echo foo 2| cat" yields "foo 2". */
4273 o_reset_to_empty_unquoted(&ctx.as_string);
4278 #if ENABLE_HUSH_CASE
4279 /* "case... in [(]word)..." - skip '(' */
4280 if (ctx.ctx_res_w == RES_MATCH
4281 && ctx.command->argv == NULL /* not (word|(... */
4282 && dest.length == 0 /* not word(... */
4283 && dest.has_quoted_part == 0 /* not ""(... */
4289 if (parse_group(&dest, &ctx, input, ch) != 0) {
4294 #if ENABLE_HUSH_CASE
4295 if (ctx.ctx_res_w == RES_MATCH)
4299 /* proper use of this character is caught by end_trigger:
4300 * if we see {, we call parse_group(..., end_trigger='}')
4301 * and it will match } earlier (not here). */
4302 syntax_error_unexpected_ch(ch);
4306 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4312 struct parse_context *pctx;
4313 IF_HAS_KEYWORDS(struct parse_context *p2;)
4315 /* Clean up allocated tree.
4316 * Sample for finding leaks on syntax error recovery path.
4317 * Run it from interactive shell, watch pmap `pidof hush`.
4318 * while if false; then false; fi; do break; fi
4319 * Samples to catch leaks at execution:
4320 * while if (true | {true;}); then echo ok; fi; do break; done
4321 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4325 /* Update pipe/command counts,
4326 * otherwise freeing may miss some */
4327 done_pipe(pctx, PIPE_SEQ);
4328 debug_printf_clean("freeing list %p from ctx %p\n",
4329 pctx->list_head, pctx);
4330 debug_print_tree(pctx->list_head, 0);
4331 free_pipe_list(pctx->list_head);
4332 debug_printf_clean("freed list %p\n", pctx->list_head);
4334 o_free_unsafe(&pctx->as_string);
4336 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4340 IF_HAS_KEYWORDS(pctx = p2;)
4341 } while (HAS_KEYWORDS && pctx);
4342 /* Free text, clear all dest fields */
4344 /* If we are not in top-level parse, we return,
4345 * our caller will propagate error.
4347 if (end_trigger != ';') {
4355 /* Discard cached input, force prompt */
4357 IF_HUSH_INTERACTIVE(input->promptme = 1;)
4363 /*** Execution routines ***/
4365 /* Expansion can recurse, need forward decls: */
4366 #if !ENABLE_HUSH_BASH_COMPAT
4367 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4368 #define expand_string_to_string(str, do_unbackslash) \
4369 expand_string_to_string(str)
4371 static char *expand_string_to_string(const char *str, int do_unbackslash);
4372 static int process_command_subs(o_string *dest, const char *s);
4374 /* expand_strvec_to_strvec() takes a list of strings, expands
4375 * all variable references within and returns a pointer to
4376 * a list of expanded strings, possibly with larger number
4377 * of strings. (Think VAR="a b"; echo $VAR).
4378 * This new list is allocated as a single malloc block.
4379 * NULL-terminated list of char* pointers is at the beginning of it,
4380 * followed by strings themselves.
4381 * Caller can deallocate entire list by single free(list). */
4383 /* Store given string, finalizing the word and starting new one whenever
4384 * we encounter IFS char(s). This is used for expanding variable values.
4385 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
4386 static int expand_on_ifs(o_string *output, int n, const char *str)
4389 int word_len = strcspn(str, G.ifs);
4391 if (!(output->o_expflags & EXP_FLAG_GLOB))
4392 o_addblock(output, str, word_len);
4394 /* Protect backslashes against globbing up :)
4395 * Example: "v='\*'; echo b$v" prints "b\*"
4396 * (and does not try to glob on "*")
4398 o_addblock_duplicate_backslash(output, str, word_len);
4399 /*/ Why can't we do it easier? */
4400 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4401 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4405 if (!*str) /* EOL - do not finalize word */
4407 o_addchr(output, '\0');
4408 debug_print_list("expand_on_ifs", output, n);
4409 n = o_save_ptr(output, n);
4410 str += strspn(str, G.ifs); /* skip ifs chars */
4412 debug_print_list("expand_on_ifs[1]", output, n);
4416 /* Helper to expand $((...)) and heredoc body. These act as if
4417 * they are in double quotes, with the exception that they are not :).
4418 * Just the rules are similar: "expand only $var and `cmd`"
4420 * Returns malloced string.
4421 * As an optimization, we return NULL if expansion is not needed.
4423 #if !ENABLE_HUSH_BASH_COMPAT
4424 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4425 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
4426 encode_then_expand_string(str)
4428 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
4431 struct in_str input;
4432 o_string dest = NULL_O_STRING;
4434 if (!strchr(str, '$')
4435 && !strchr(str, '\\')
4436 #if ENABLE_HUSH_TICK
4437 && !strchr(str, '`')
4443 /* We need to expand. Example:
4444 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4446 setup_string_in_str(&input, str);
4447 encode_string(NULL, &dest, &input, EOF, process_bkslash);
4448 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4449 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4450 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4451 o_free_unsafe(&dest);
4455 #if ENABLE_SH_MATH_SUPPORT
4456 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
4458 arith_eval_hooks_t hooks;
4462 hooks.lookupvar = get_local_var_value;
4463 hooks.setvar = set_local_var_from_halves;
4464 //hooks.endofname = endofname;
4465 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4466 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
4472 #if ENABLE_HUSH_BASH_COMPAT
4473 /* ${var/[/]pattern[/repl]} helpers */
4474 static char *strstr_pattern(char *val, const char *pattern, int *size)
4477 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4478 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4485 /* Optimization: if "*pat" did not match the start of "string",
4486 * we know that "tring", "ring" etc will not match too:
4488 if (pattern[0] == '*')
4493 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4495 char *result = NULL;
4496 unsigned res_len = 0;
4497 unsigned repl_len = strlen(repl);
4501 char *s = strstr_pattern(val, pattern, &size);
4505 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4506 memcpy(result + res_len, val, s - val);
4508 strcpy(result + res_len, repl);
4509 res_len += repl_len;
4510 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4516 if (val[0] && result) {
4517 result = xrealloc(result, res_len + strlen(val) + 1);
4518 strcpy(result + res_len, val);
4519 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4521 debug_printf_varexp("result:'%s'\n", result);
4527 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4529 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4531 const char *val = NULL;
4532 char *to_be_freed = NULL;
4537 char exp_save = exp_save; /* for compiler */
4538 char *exp_saveptr; /* points to expansion operator */
4539 char *exp_word = exp_word; /* for compiler */
4542 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4544 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4546 first_char = arg[0] = arg0 & 0x7f;
4549 if (first_char == '#' /* ${#... */
4550 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4552 /* It must be length operator: ${#var} */
4556 /* Maybe handle parameter expansion */
4557 if (exp_saveptr /* if 2nd char is one of expansion operators */
4558 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4560 /* ${?:0}, ${#[:]%0} etc */
4561 exp_saveptr = var + 1;
4563 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4564 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4566 exp_op = exp_save = *exp_saveptr;
4568 exp_word = exp_saveptr + 1;
4569 if (exp_op == ':') {
4570 exp_op = *exp_word++;
4571 //TODO: try ${var:} and ${var:bogus} in non-bash config
4572 if (ENABLE_HUSH_BASH_COMPAT
4573 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4575 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4580 *exp_saveptr = '\0';
4581 } /* else: it's not an expansion op, but bare ${var} */
4584 /* Look up the variable in question */
4585 if (isdigit(var[0])) {
4586 /* parse_dollar should have vetted var for us */
4587 int n = xatoi_positive(var);
4588 if (n < G.global_argc)
4589 val = G.global_argv[n];
4590 /* else val remains NULL: $N with too big N */
4594 val = utoa(G.root_pid);
4596 case '!': /* bg pid */
4597 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
4599 case '?': /* exitcode */
4600 val = utoa(G.last_exitcode);
4602 case '#': /* argc */
4603 val = utoa(G.global_argc ? G.global_argc-1 : 0);
4606 val = get_local_var_value(var);
4610 /* Handle any expansions */
4611 if (exp_op == 'L') {
4612 debug_printf_expand("expand: length(%s)=", val);
4613 val = utoa(val ? strlen(val) : 0);
4614 debug_printf_expand("%s\n", val);
4615 } else if (exp_op) {
4616 if (exp_op == '%' || exp_op == '#') {
4617 /* Standard-mandated substring removal ops:
4618 * ${parameter%word} - remove smallest suffix pattern
4619 * ${parameter%%word} - remove largest suffix pattern
4620 * ${parameter#word} - remove smallest prefix pattern
4621 * ${parameter##word} - remove largest prefix pattern
4623 * Word is expanded to produce a glob pattern.
4624 * Then var's value is matched to it and matching part removed.
4626 if (val && val[0]) {
4630 unsigned scan_flags = pick_scan(exp_op, *exp_word);
4631 if (exp_op == *exp_word) /* ## or %% */
4633 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4635 exp_word = exp_exp_word;
4636 /* HACK ALERT. We depend here on the fact that
4637 * G.global_argv and results of utoa and get_local_var_value
4638 * are actually in writable memory:
4639 * scan_and_match momentarily stores NULs there. */
4641 loc = scan_and_match(t, exp_word, scan_flags);
4642 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
4643 // exp_op, t, exp_word, loc);
4645 if (loc) { /* match was found */
4646 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
4647 val = loc; /* take right part */
4649 val = to_be_freed = xstrndup(val, loc - val); /* left */
4653 #if ENABLE_HUSH_BASH_COMPAT
4654 else if (exp_op == '/' || exp_op == '\\') {
4655 /* It's ${var/[/]pattern[/repl]} thing.
4656 * Note that in encoded form it has TWO parts:
4657 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4658 * and if // is used, it is encoded as \:
4659 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4661 /* Empty variable always gives nothing: */
4662 // "v=''; echo ${v/*/w}" prints "", not "w"
4663 if (val && val[0]) {
4664 /* pattern uses non-standard expansion.
4665 * repl should be unbackslashed and globbed
4666 * by the usual expansion rules:
4668 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
4669 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
4670 * v='a bz'; echo ${v/a*z/a*z} prints "az"
4671 * v='a bz'; echo ${v/a*z/\z} prints "z"
4672 * (note that a*z _pattern_ is never globbed!)
4674 char *pattern, *repl, *t;
4675 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
4677 pattern = xstrdup(exp_word);
4678 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
4679 *p++ = SPECIAL_VAR_SYMBOL;
4681 p = strchr(p, SPECIAL_VAR_SYMBOL);
4683 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
4684 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
4685 /* HACK ALERT. We depend here on the fact that
4686 * G.global_argv and results of utoa and get_local_var_value
4687 * are actually in writable memory:
4688 * replace_pattern momentarily stores NULs there. */
4690 to_be_freed = replace_pattern(t,
4692 (repl ? repl : exp_word),
4694 if (to_be_freed) /* at least one replace happened */
4701 else if (exp_op == ':') {
4702 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
4703 /* It's ${var:N[:M]} bashism.
4704 * Note that in encoded form it has TWO parts:
4705 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
4710 beg = expand_and_evaluate_arith(exp_word, &errcode);
4711 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
4712 *p++ = SPECIAL_VAR_SYMBOL;
4714 p = strchr(p, SPECIAL_VAR_SYMBOL);
4716 len = expand_and_evaluate_arith(exp_word, &errcode);
4717 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
4719 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
4720 if (beg < 0) /* bash compat */
4722 debug_printf_varexp("from val:'%s'\n", val);
4723 if (len == 0 || !val || beg >= strlen(val))
4726 /* Paranoia. What if user entered 9999999999999
4727 * which fits in arith_t but not int? */
4730 val = to_be_freed = xstrndup(val + beg, len);
4732 debug_printf_varexp("val:'%s'\n", val);
4736 die_if_script("malformed ${%s:...}", var);
4739 } else { /* one of "-=+?" */
4740 /* Standard-mandated substitution ops:
4741 * ${var?word} - indicate error if unset
4742 * If var is unset, word (or a message indicating it is unset
4743 * if word is null) is written to standard error
4744 * and the shell exits with a non-zero exit status.
4745 * Otherwise, the value of var is substituted.
4746 * ${var-word} - use default value
4747 * If var is unset, word is substituted.
4748 * ${var=word} - assign and use default value
4749 * If var is unset, word is assigned to var.
4750 * In all cases, final value of var is substituted.
4751 * ${var+word} - use alternative value
4752 * If var is unset, null is substituted.
4753 * Otherwise, word is substituted.
4755 * Word is subjected to tilde expansion, parameter expansion,
4756 * command substitution, and arithmetic expansion.
4757 * If word is not needed, it is not expanded.
4759 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
4760 * but also treat null var as if it is unset.
4762 int use_word = (!val || ((exp_save == ':') && !val[0]));
4764 use_word = !use_word;
4765 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
4766 (exp_save == ':') ? "true" : "false", use_word);
4768 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4770 exp_word = to_be_freed;
4771 if (exp_op == '?') {
4772 /* mimic bash message */
4773 die_if_script("%s: %s",
4775 exp_word[0] ? exp_word : "parameter null or not set"
4777 //TODO: how interactive bash aborts expansion mid-command?
4782 if (exp_op == '=') {
4783 /* ${var=[word]} or ${var:=[word]} */
4784 if (isdigit(var[0]) || var[0] == '#') {
4785 /* mimic bash message */
4786 die_if_script("$%s: cannot assign in this way", var);
4789 char *new_var = xasprintf("%s=%s", var, val);
4790 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4794 } /* one of "-=+?" */
4796 *exp_saveptr = exp_save;
4802 *to_be_freed_pp = to_be_freed;
4806 /* Expand all variable references in given string, adding words to list[]
4807 * at n, n+1,... positions. Return updated n (so that list[n] is next one
4808 * to be filled). This routine is extremely tricky: has to deal with
4809 * variables/parameters with whitespace, $* and $@, and constructs like
4810 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
4811 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
4813 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
4814 * expansion of right-hand side of assignment == 1-element expand.
4816 char cant_be_null = 0; /* only bit 0x80 matters */
4819 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
4820 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
4821 debug_print_list("expand_vars_to_list", output, n);
4822 n = o_save_ptr(output, n);
4823 debug_print_list("expand_vars_to_list[0]", output, n);
4825 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
4827 char *to_be_freed = NULL;
4828 const char *val = NULL;
4829 #if ENABLE_HUSH_TICK
4830 o_string subst_result = NULL_O_STRING;
4832 #if ENABLE_SH_MATH_SUPPORT
4833 char arith_buf[sizeof(arith_t)*3 + 2];
4835 o_addblock(output, arg, p - arg);
4836 debug_print_list("expand_vars_to_list[1]", output, n);
4838 p = strchr(p, SPECIAL_VAR_SYMBOL);
4840 /* Fetch special var name (if it is indeed one of them)
4841 * and quote bit, force the bit on if singleword expansion -
4842 * important for not getting v=$@ expand to many words. */
4843 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
4845 /* Is this variable quoted and thus expansion can't be null?
4846 * "$@" is special. Even if quoted, it can still
4847 * expand to nothing (not even an empty string),
4848 * thus it is excluded. */
4849 if ((first_ch & 0x7f) != '@')
4850 cant_be_null |= first_ch;
4852 switch (first_ch & 0x7f) {
4853 /* Highest bit in first_ch indicates that var is double-quoted */
4857 if (!G.global_argv[1])
4860 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
4861 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
4862 while (G.global_argv[i]) {
4863 n = expand_on_ifs(output, n, G.global_argv[i]);
4864 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
4865 if (G.global_argv[i++][0] && G.global_argv[i]) {
4866 /* this argv[] is not empty and not last:
4867 * put terminating NUL, start new word */
4868 o_addchr(output, '\0');
4869 debug_print_list("expand_vars_to_list[2]", output, n);
4870 n = o_save_ptr(output, n);
4871 debug_print_list("expand_vars_to_list[3]", output, n);
4875 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
4876 * and in this case should treat it like '$*' - see 'else...' below */
4877 if (first_ch == ('@'|0x80) /* quoted $@ */
4878 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
4881 o_addQstr(output, G.global_argv[i]);
4882 if (++i >= G.global_argc)
4884 o_addchr(output, '\0');
4885 debug_print_list("expand_vars_to_list[4]", output, n);
4886 n = o_save_ptr(output, n);
4888 } else { /* quoted $* (or v="$@" case): add as one word */
4890 o_addQstr(output, G.global_argv[i]);
4891 if (!G.global_argv[++i])
4894 o_addchr(output, G.ifs[0]);
4899 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
4900 /* "Empty variable", used to make "" etc to not disappear */
4902 cant_be_null = 0x80;
4904 #if ENABLE_HUSH_TICK
4905 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
4906 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
4908 /* Can't just stuff it into output o_string,
4909 * expanded result may need to be globbed
4910 * and $IFS-splitted */
4911 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
4912 G.last_exitcode = process_command_subs(&subst_result, arg);
4913 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
4914 val = subst_result.data;
4917 #if ENABLE_SH_MATH_SUPPORT
4918 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
4922 arg++; /* skip '+' */
4923 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
4924 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
4925 res = expand_and_evaluate_arith(arg, &errcode);
4928 const char *msg = "error in arithmetic";
4931 msg = "exponent less than 0";
4934 msg = "divide by 0";
4937 msg = "expression recursion loop detected";
4942 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
4943 sprintf(arith_buf, arith_t_fmt, res);
4949 val = expand_one_var(&to_be_freed, arg, &p);
4950 IF_HUSH_TICK(store_val:)
4951 if (!(first_ch & 0x80)) { /* unquoted $VAR */
4952 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
4953 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4954 if (val && val[0]) {
4955 n = expand_on_ifs(output, n, val);
4958 } else { /* quoted $VAR, val will be appended below */
4959 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
4960 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4964 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
4966 if (val && val[0]) {
4967 o_addQstr(output, val);
4971 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
4972 * Do the check to avoid writing to a const string. */
4973 if (*p != SPECIAL_VAR_SYMBOL)
4974 *p = SPECIAL_VAR_SYMBOL;
4976 #if ENABLE_HUSH_TICK
4977 o_free(&subst_result);
4980 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
4983 debug_print_list("expand_vars_to_list[a]", output, n);
4984 /* this part is literal, and it was already pre-quoted
4985 * if needed (much earlier), do not use o_addQstr here! */
4986 o_addstr_with_NUL(output, arg);
4987 debug_print_list("expand_vars_to_list[b]", output, n);
4988 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
4989 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
4992 /* allow to reuse list[n] later without re-growth */
4993 output->has_empty_slot = 1;
4995 o_addchr(output, '\0');
5001 static char **expand_variables(char **argv, unsigned expflags)
5005 o_string output = NULL_O_STRING;
5007 output.o_expflags = expflags;
5011 n = expand_vars_to_list(&output, n, *argv);
5014 debug_print_list("expand_variables", &output, n);
5016 /* output.data (malloced in one block) gets returned in "list" */
5017 list = o_finalize_list(&output, n);
5018 debug_print_strings("expand_variables[1]", list);
5022 static char **expand_strvec_to_strvec(char **argv)
5024 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5027 #if ENABLE_HUSH_BASH_COMPAT
5028 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5030 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5034 /* Used for expansion of right hand of assignments,
5035 * $((...)), heredocs, variable espansion parts.
5037 * NB: should NOT do globbing!
5038 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5040 static char *expand_string_to_string(const char *str, int do_unbackslash)
5042 #if !ENABLE_HUSH_BASH_COMPAT
5043 const int do_unbackslash = 1;
5045 char *argv[2], **list;
5047 debug_printf_expand("string_to_string<='%s'\n", str);
5048 /* This is generally an optimization, but it also
5049 * handles "", which otherwise trips over !list[0] check below.
5050 * (is this ever happens that we actually get str="" here?)
5052 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5053 //TODO: Can use on strings with \ too, just unbackslash() them?
5054 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5055 return xstrdup(str);
5058 argv[0] = (char*)str;
5060 list = expand_variables(argv, do_unbackslash
5061 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5062 : EXP_FLAG_SINGLEWORD
5065 if (!list[0] || list[1])
5066 bb_error_msg_and_die("BUG in varexp2");
5067 /* actually, just move string 2*sizeof(char*) bytes back */
5068 overlapping_strcpy((char*)list, list[0]);
5070 unbackslash((char*)list);
5071 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5075 /* Used for "eval" builtin */
5076 static char* expand_strvec_to_string(char **argv)
5080 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5081 /* Convert all NULs to spaces */
5086 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5087 bb_error_msg_and_die("BUG in varexp3");
5088 /* bash uses ' ' regardless of $IFS contents */
5093 overlapping_strcpy((char*)list, list[0]);
5094 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5098 static char **expand_assignments(char **argv, int count)
5103 G.expanded_assignments = p = NULL;
5104 /* Expand assignments into one string each */
5105 for (i = 0; i < count; i++) {
5106 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5108 G.expanded_assignments = NULL;
5115 void re_execute_shell(char ***to_free, const char *s,
5116 char *g_argv0, char **g_argv,
5117 char **builtin_argv) NORETURN;
5119 static void reset_traps_to_defaults(void)
5121 /* This function is always called in a child shell
5122 * after fork (not vfork, NOMMU doesn't use this function).
5127 /* Child shells are not interactive.
5128 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5129 * Testcase: (while :; do :; done) + ^Z should background.
5130 * Same goes for SIGTERM, SIGHUP, SIGINT.
5132 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
5133 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
5135 /* Switching off SPECIAL_INTERACTIVE_SIGS.
5136 * Stupid. It can be done with *single* &= op, but we can't use
5137 * the fact that G.blocked_set is implemented as a bitmask
5139 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
5143 /* Careful. Only if no trap or trap is not "" */
5144 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
5145 sigdelset(&G.blocked_set, sig);
5152 /* Our homegrown sig mask is saner to work with :) */
5153 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5155 /* Resetting all traps to default except empty ones */
5156 mask = G.non_DFL_mask;
5157 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
5158 if (!G.traps[sig] || !G.traps[sig][0])
5161 G.traps[sig] = NULL;
5162 /* There is no signal for 0 (EXIT) */
5165 /* There was a trap handler, we just removed it.
5166 * But if sig still has non-DFL handling,
5167 * we should not unblock the sig. */
5170 sigdelset(&G.blocked_set, sig);
5172 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5177 static void re_execute_shell(char ***to_free, const char *s,
5178 char *g_argv0, char **g_argv,
5179 char **builtin_argv) NORETURN;
5180 static void re_execute_shell(char ***to_free, const char *s,
5181 char *g_argv0, char **g_argv,
5182 char **builtin_argv)
5184 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5185 /* delims + 2 * (number of bytes in printed hex numbers) */
5186 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5187 char *heredoc_argv[4];
5188 struct variable *cur;
5189 # if ENABLE_HUSH_FUNCTIONS
5190 struct function *funcp;
5194 unsigned long long empty_trap_mask;
5196 if (!g_argv0) { /* heredoc */
5197 argv = heredoc_argv;
5198 argv[0] = (char *) G.argv0_for_re_execing;
5199 argv[1] = (char *) "-<";
5200 argv[2] = (char *) s;
5202 pp = &argv[3]; /* used as pointer to empty environment */
5208 if (pp) while (*pp++)
5211 empty_trap_mask = 0;
5214 for (sig = 1; sig < NSIG; sig++) {
5215 if (G.traps[sig] && !G.traps[sig][0])
5216 empty_trap_mask |= 1LL << sig;
5220 sprintf(param_buf, NOMMU_HACK_FMT
5221 , (unsigned) G.root_pid
5222 , (unsigned) G.root_ppid
5223 , (unsigned) G.last_bg_pid
5224 , (unsigned) G.last_exitcode
5227 IF_HUSH_LOOPS(, G.depth_of_loop)
5229 # undef NOMMU_HACK_FMT
5230 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5231 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5234 for (cur = G.top_var; cur; cur = cur->next) {
5235 if (!cur->flg_export || cur->flg_read_only)
5238 # if ENABLE_HUSH_FUNCTIONS
5239 for (funcp = G.top_func; funcp; funcp = funcp->next)
5245 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5246 *pp++ = (char *) G.argv0_for_re_execing;
5248 for (cur = G.top_var; cur; cur = cur->next) {
5249 if (strcmp(cur->varstr, hush_version_str) == 0)
5251 if (cur->flg_read_only) {
5252 *pp++ = (char *) "-R";
5253 *pp++ = cur->varstr;
5254 } else if (!cur->flg_export) {
5255 *pp++ = (char *) "-V";
5256 *pp++ = cur->varstr;
5259 # if ENABLE_HUSH_FUNCTIONS
5260 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5261 *pp++ = (char *) "-F";
5262 *pp++ = funcp->name;
5263 *pp++ = funcp->body_as_string;
5266 /* We can pass activated traps here. Say, -Tnn:trap_string
5268 * However, POSIX says that subshells reset signals with traps
5270 * I tested bash-3.2 and it not only does that with true subshells
5271 * of the form ( list ), but with any forked children shells.
5272 * I set trap "echo W" WINCH; and then tried:
5274 * { echo 1; sleep 20; echo 2; } &
5275 * while true; do echo 1; sleep 20; echo 2; break; done &
5276 * true | { echo 1; sleep 20; echo 2; } | cat
5278 * In all these cases sending SIGWINCH to the child shell
5279 * did not run the trap. If I add trap "echo V" WINCH;
5280 * _inside_ group (just before echo 1), it works.
5282 * I conclude it means we don't need to pass active traps here.
5283 * Even if we would use signal handlers instead of signal masking
5284 * in order to implement trap handling,
5285 * exec syscall below resets signals to SIG_DFL for us.
5287 *pp++ = (char *) "-c";
5290 while (*++builtin_argv)
5291 *pp++ = *builtin_argv;
5292 *pp++ = (char *) "";
5297 /* *pp = NULL; - is already there */
5301 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5302 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5303 execve(bb_busybox_exec_path, argv, pp);
5304 /* Fallback. Useful for init=/bin/hush usage etc */
5305 if (argv[0][0] == '/')
5306 execve(argv[0], argv, pp);
5307 xfunc_error_retval = 127;
5308 bb_error_msg_and_die("can't re-execute the shell");
5310 #endif /* !BB_MMU */
5313 static int run_and_free_list(struct pipe *pi);
5315 /* Executing from string: eval, sh -c '...'
5316 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5317 * end_trigger controls how often we stop parsing
5318 * NUL: parse all, execute, return
5319 * ';': parse till ';' or newline, execute, repeat till EOF
5321 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5323 /* Why we need empty flag?
5324 * An obscure corner case "false; ``; echo $?":
5325 * empty command in `` should still set $? to 0.
5326 * But we can't just set $? to 0 at the start,
5327 * this breaks "false; echo `echo $?`" case.
5331 struct pipe *pipe_list;
5333 pipe_list = parse_stream(NULL, inp, end_trigger);
5334 if (!pipe_list) { /* EOF */
5336 G.last_exitcode = 0;
5339 debug_print_tree(pipe_list, 0);
5340 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5341 run_and_free_list(pipe_list);
5346 static void parse_and_run_string(const char *s)
5348 struct in_str input;
5349 setup_string_in_str(&input, s);
5350 parse_and_run_stream(&input, '\0');
5353 static void parse_and_run_file(FILE *f)
5355 struct in_str input;
5356 setup_file_in_str(&input, f);
5357 parse_and_run_stream(&input, ';');
5360 #if ENABLE_HUSH_TICK
5361 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5366 char **to_free = NULL;
5370 pid = BB_MMU ? xfork() : xvfork();
5371 if (pid == 0) { /* child */
5372 disable_restore_tty_pgrp_on_exit();
5373 /* Process substitution is not considered to be usual
5374 * 'command execution'.
5375 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5382 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5383 close(channel[0]); /* NB: close _first_, then move fd! */
5384 xmove_fd(channel[1], 1);
5385 /* Prevent it from trying to handle ctrl-z etc */
5386 IF_HUSH_JOB(G.run_list_level = 1;)
5387 /* Awful hack for `trap` or $(trap).
5389 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5390 * contains an example where "trap" is executed in a subshell:
5392 * save_traps=$(trap)
5394 * eval "$save_traps"
5396 * Standard does not say that "trap" in subshell shall print
5397 * parent shell's traps. It only says that its output
5398 * must have suitable form, but then, in the above example
5399 * (which is not supposed to be normative), it implies that.
5401 * bash (and probably other shell) does implement it
5402 * (traps are reset to defaults, but "trap" still shows them),
5403 * but as a result, "trap" logic is hopelessly messed up:
5406 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5407 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5408 * # true | trap <--- trap is in subshell - no output (ditto)
5409 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5410 * trap -- 'echo Ho' SIGWINCH
5411 * # echo `(trap)` <--- in subshell in subshell - output
5412 * trap -- 'echo Ho' SIGWINCH
5413 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5414 * trap -- 'echo Ho' SIGWINCH
5416 * The rules when to forget and when to not forget traps
5417 * get really complex and nonsensical.
5419 * Our solution: ONLY bare $(trap) or `trap` is special.
5421 s = skip_whitespace(s);
5422 if (strncmp(s, "trap", 4) == 0
5423 && skip_whitespace(s + 4)[0] == '\0'
5425 static const char *const argv[] = { NULL, NULL };
5426 builtin_trap((char**)argv);
5427 exit(0); /* not _exit() - we need to fflush */
5430 reset_traps_to_defaults();
5431 parse_and_run_string(s);
5432 _exit(G.last_exitcode);
5434 /* We re-execute after vfork on NOMMU. This makes this script safe:
5435 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5436 * huge=`cat BIG` # was blocking here forever
5439 re_execute_shell(&to_free,
5449 # if ENABLE_HUSH_FAST
5451 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5452 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5453 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5455 enable_restore_tty_pgrp_on_exit();
5460 close_on_exec_on(channel[0]);
5461 return xfdopen_for_read(channel[0]);
5464 /* Return code is exit status of the process that is run. */
5465 static int process_command_subs(o_string *dest, const char *s)
5468 struct in_str pipe_str;
5470 int status, ch, eol_cnt;
5472 fp = generate_stream_from_string(s, &pid);
5474 /* Now send results of command back into original context */
5475 setup_file_in_str(&pipe_str, fp);
5477 while ((ch = i_getch(&pipe_str)) != EOF) {
5483 o_addchr(dest, '\n');
5486 o_addQchr(dest, ch);
5489 debug_printf("done reading from `cmd` pipe, closing it\n");
5491 /* We need to extract exitcode. Test case
5492 * "true; echo `sleep 1; false` $?"
5494 safe_waitpid(pid, &status, 0);
5495 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5496 return WEXITSTATUS(status);
5498 #endif /* ENABLE_HUSH_TICK */
5501 static void setup_heredoc(struct redir_struct *redir)
5503 struct fd_pair pair;
5506 /* the _body_ of heredoc (misleading field name) */
5507 const char *heredoc = redir->rd_filename;
5514 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5515 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5519 len = strlen(heredoc);
5521 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5523 xmove_fd(pair.rd, redir->rd_fd);
5525 /* Try writing without forking. Newer kernels have
5526 * dynamically growing pipes. Must use non-blocking write! */
5529 written = write(pair.wr, heredoc, len);
5540 ndelay_off(pair.wr);
5542 /* Okay, pipe buffer was not big enough */
5543 /* Note: we must not create a stray child (bastard? :)
5544 * for the unsuspecting parent process. Child creates a grandchild
5545 * and exits before parent execs the process which consumes heredoc
5546 * (that exec happens after we return from this function) */
5553 disable_restore_tty_pgrp_on_exit();
5554 pid = BB_MMU ? xfork() : xvfork();
5558 close(redir->rd_fd); /* read side of the pipe */
5560 full_write(pair.wr, heredoc, len); /* may loop or block */
5563 /* Delegate blocking writes to another process */
5564 xmove_fd(pair.wr, STDOUT_FILENO);
5565 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
5569 #if ENABLE_HUSH_FAST
5571 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5573 enable_restore_tty_pgrp_on_exit();
5579 wait(NULL); /* wait till child has died */
5582 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
5583 * and stderr if they are redirected. */
5584 static int setup_redirects(struct command *prog, int squirrel[])
5587 struct redir_struct *redir;
5589 for (redir = prog->redirects; redir; redir = redir->next) {
5590 if (redir->rd_type == REDIRECT_HEREDOC2) {
5591 /* rd_fd<<HERE case */
5592 if (squirrel && redir->rd_fd < 3
5593 && squirrel[redir->rd_fd] < 0
5595 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5597 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
5599 debug_printf_parse("set heredoc '%s'\n",
5600 redir->rd_filename);
5601 setup_heredoc(redir);
5605 if (redir->rd_dup == REDIRFD_TO_FILE) {
5606 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
5608 if (redir->rd_filename == NULL) {
5609 /* Something went wrong in the parse.
5610 * Pretend it didn't happen */
5611 bb_error_msg("bug in redirect parse");
5614 mode = redir_table[redir->rd_type].mode;
5615 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
5616 openfd = open_or_warn(p, mode);
5619 /* this could get lost if stderr has been redirected, but
5620 * bash and ash both lose it as well (though zsh doesn't!) */
5621 //what the above comment tries to say?
5625 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
5626 openfd = redir->rd_dup;
5629 if (openfd != redir->rd_fd) {
5630 if (squirrel && redir->rd_fd < 3
5631 && squirrel[redir->rd_fd] < 0
5633 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5635 if (openfd == REDIRFD_CLOSE) {
5636 /* "n>-" means "close me" */
5637 close(redir->rd_fd);
5639 xdup2(openfd, redir->rd_fd);
5640 if (redir->rd_dup == REDIRFD_TO_FILE)
5648 static void restore_redirects(int squirrel[])
5651 for (i = 0; i < 3; i++) {
5654 /* We simply die on error */
5660 static char *find_in_path(const char *arg)
5663 const char *PATH = get_local_var_value("PATH");
5669 const char *end = strchrnul(PATH, ':');
5670 int sz = end - PATH; /* must be int! */
5674 ret = xasprintf("%.*s/%s", sz, PATH, arg);
5676 /* We have xxx::yyyy in $PATH,
5677 * it means "use current dir" */
5680 if (access(ret, F_OK) == 0)
5693 static const struct built_in_command *find_builtin_helper(const char *name,
5694 const struct built_in_command *x,
5695 const struct built_in_command *end)
5698 if (strcmp(name, x->b_cmd) != 0) {
5702 debug_printf_exec("found builtin '%s'\n", name);
5707 static const struct built_in_command *find_builtin1(const char *name)
5709 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
5711 static const struct built_in_command *find_builtin(const char *name)
5713 const struct built_in_command *x = find_builtin1(name);
5716 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
5719 #if ENABLE_HUSH_FUNCTIONS
5720 static struct function **find_function_slot(const char *name)
5722 struct function **funcpp = &G.top_func;
5724 if (strcmp(name, (*funcpp)->name) == 0) {
5727 funcpp = &(*funcpp)->next;
5732 static const struct function *find_function(const char *name)
5734 const struct function *funcp = *find_function_slot(name);
5736 debug_printf_exec("found function '%s'\n", name);
5740 /* Note: takes ownership on name ptr */
5741 static struct function *new_function(char *name)
5743 struct function **funcpp = find_function_slot(name);
5744 struct function *funcp = *funcpp;
5746 if (funcp != NULL) {
5747 struct command *cmd = funcp->parent_cmd;
5748 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
5750 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
5752 /* Note: if !funcp->body, do not free body_as_string!
5753 * This is a special case of "-F name body" function:
5754 * body_as_string was not malloced! */
5756 free_pipe_list(funcp->body);
5758 free(funcp->body_as_string);
5762 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
5763 cmd->argv[0] = funcp->name;
5764 cmd->group = funcp->body;
5766 cmd->group_as_string = funcp->body_as_string;
5770 debug_printf_exec("remembering new function '%s'\n", name);
5771 funcp = *funcpp = xzalloc(sizeof(*funcp));
5772 /*funcp->next = NULL;*/
5779 static void unset_func(const char *name)
5781 struct function **funcpp = find_function_slot(name);
5782 struct function *funcp = *funcpp;
5784 if (funcp != NULL) {
5785 debug_printf_exec("freeing function '%s'\n", funcp->name);
5786 *funcpp = funcp->next;
5787 /* funcp is unlinked now, deleting it.
5788 * Note: if !funcp->body, the function was created by
5789 * "-F name body", do not free ->body_as_string
5790 * and ->name as they were not malloced. */
5792 free_pipe_list(funcp->body);
5795 free(funcp->body_as_string);
5803 #define exec_function(to_free, funcp, argv) \
5804 exec_function(funcp, argv)
5806 static void exec_function(char ***to_free,
5807 const struct function *funcp,
5808 char **argv) NORETURN;
5809 static void exec_function(char ***to_free,
5810 const struct function *funcp,
5816 argv[0] = G.global_argv[0];
5817 G.global_argv = argv;
5821 /* On MMU, funcp->body is always non-NULL */
5822 n = run_list(funcp->body);
5826 re_execute_shell(to_free,
5827 funcp->body_as_string,
5834 static int run_function(const struct function *funcp, char **argv)
5840 save_and_replace_G_args(&sv, argv);
5842 /* "we are in function, ok to use return" */
5843 sv_flg = G.flag_return_in_progress;
5844 G.flag_return_in_progress = -1;
5845 # if ENABLE_HUSH_LOCAL
5846 G.func_nest_level++;
5849 /* On MMU, funcp->body is always non-NULL */
5852 /* Function defined by -F */
5853 parse_and_run_string(funcp->body_as_string);
5854 rc = G.last_exitcode;
5858 rc = run_list(funcp->body);
5861 # if ENABLE_HUSH_LOCAL
5863 struct variable *var;
5864 struct variable **var_pp;
5866 var_pp = &G.top_var;
5867 while ((var = *var_pp) != NULL) {
5868 if (var->func_nest_level < G.func_nest_level) {
5869 var_pp = &var->next;
5873 if (var->flg_export)
5874 bb_unsetenv(var->varstr);
5875 /* Remove from global list */
5876 *var_pp = var->next;
5882 G.func_nest_level--;
5885 G.flag_return_in_progress = sv_flg;
5887 restore_G_args(&sv, argv);
5891 #endif /* ENABLE_HUSH_FUNCTIONS */
5895 #define exec_builtin(to_free, x, argv) \
5896 exec_builtin(x, argv)
5898 #define exec_builtin(to_free, x, argv) \
5899 exec_builtin(to_free, argv)
5901 static void exec_builtin(char ***to_free,
5902 const struct built_in_command *x,
5903 char **argv) NORETURN;
5904 static void exec_builtin(char ***to_free,
5905 const struct built_in_command *x,
5909 int rcode = x->b_function(argv);
5913 /* On NOMMU, we must never block!
5914 * Example: { sleep 99 | read line; } & echo Ok
5916 re_execute_shell(to_free,
5925 static void execvp_or_die(char **argv) NORETURN;
5926 static void execvp_or_die(char **argv)
5928 debug_printf_exec("execing '%s'\n", argv[0]);
5929 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5930 execvp(argv[0], argv);
5931 bb_perror_msg("can't execute '%s'", argv[0]);
5932 _exit(127); /* bash compat */
5935 #if ENABLE_HUSH_MODE_X
5936 static void dump_cmd_in_x_mode(char **argv)
5938 if (G_x_mode && argv) {
5939 /* We want to output the line in one write op */
5947 len += strlen(argv[n++]) + 1;
5953 p += sprintf(p, " %s", argv[n++]);
5961 # define dump_cmd_in_x_mode(argv) ((void)0)
5965 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
5966 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
5967 #define pseudo_exec(nommu_save, command, argv_expanded) \
5968 pseudo_exec(command, argv_expanded)
5971 /* Called after [v]fork() in run_pipe, or from builtin_exec.
5973 * Don't exit() here. If you don't exec, use _exit instead.
5974 * The at_exit handlers apparently confuse the calling process,
5975 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
5976 static void pseudo_exec_argv(nommu_save_t *nommu_save,
5977 char **argv, int assignment_cnt,
5978 char **argv_expanded) NORETURN;
5979 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
5980 char **argv, int assignment_cnt,
5981 char **argv_expanded)
5985 new_env = expand_assignments(argv, assignment_cnt);
5986 dump_cmd_in_x_mode(new_env);
5988 if (!argv[assignment_cnt]) {
5989 /* Case when we are here: ... | var=val | ...
5990 * (note that we do not exit early, i.e., do not optimize out
5991 * expand_assignments(): think about ... | var=`sleep 1` | ...
5993 free_strings(new_env);
5994 _exit(EXIT_SUCCESS);
5998 set_vars_and_save_old(new_env);
5999 free(new_env); /* optional */
6000 /* we can also destroy set_vars_and_save_old's return value,
6003 nommu_save->new_env = new_env;
6004 nommu_save->old_vars = set_vars_and_save_old(new_env);
6007 if (argv_expanded) {
6008 argv = argv_expanded;
6010 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6012 nommu_save->argv = argv;
6015 dump_cmd_in_x_mode(argv);
6017 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6018 if (strchr(argv[0], '/') != NULL)
6022 /* Check if the command matches any of the builtins.
6023 * Depending on context, this might be redundant. But it's
6024 * easier to waste a few CPU cycles than it is to figure out
6025 * if this is one of those cases.
6028 /* On NOMMU, it is more expensive to re-execute shell
6029 * just in order to run echo or test builtin.
6030 * It's better to skip it here and run corresponding
6031 * non-builtin later. */
6032 const struct built_in_command *x;
6033 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6035 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6038 #if ENABLE_HUSH_FUNCTIONS
6039 /* Check if the command matches any functions */
6041 const struct function *funcp = find_function(argv[0]);
6043 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6048 #if ENABLE_FEATURE_SH_STANDALONE
6049 /* Check if the command matches any busybox applets */
6051 int a = find_applet_by_name(argv[0]);
6053 # if BB_MMU /* see above why on NOMMU it is not allowed */
6054 if (APPLET_IS_NOEXEC(a)) {
6055 debug_printf_exec("running applet '%s'\n", argv[0]);
6056 run_applet_no_and_exit(a, argv);
6059 /* Re-exec ourselves */
6060 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6061 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6062 execv(bb_busybox_exec_path, argv);
6063 /* If they called chroot or otherwise made the binary no longer
6064 * executable, fall through */
6069 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6072 execvp_or_die(argv);
6075 /* Called after [v]fork() in run_pipe
6077 static void pseudo_exec(nommu_save_t *nommu_save,
6078 struct command *command,
6079 char **argv_expanded) NORETURN;
6080 static void pseudo_exec(nommu_save_t *nommu_save,
6081 struct command *command,
6082 char **argv_expanded)
6084 if (command->argv) {
6085 pseudo_exec_argv(nommu_save, command->argv,
6086 command->assignment_cnt, argv_expanded);
6089 if (command->group) {
6090 /* Cases when we are here:
6093 * ... | ( list ) | ...
6094 * ... | { list } | ...
6098 debug_printf_exec("pseudo_exec: run_list\n");
6099 reset_traps_to_defaults();
6100 rcode = run_list(command->group);
6101 /* OK to leak memory by not calling free_pipe_list,
6102 * since this process is about to exit */
6105 re_execute_shell(&nommu_save->argv_from_re_execing,
6106 command->group_as_string,
6113 /* Case when we are here: ... | >file */
6114 debug_printf_exec("pseudo_exec'ed null command\n");
6115 _exit(EXIT_SUCCESS);
6119 static const char *get_cmdtext(struct pipe *pi)
6125 /* This is subtle. ->cmdtext is created only on first backgrounding.
6126 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6127 * On subsequent bg argv is trashed, but we won't use it */
6130 argv = pi->cmds[0].argv;
6131 if (!argv || !argv[0]) {
6132 pi->cmdtext = xzalloc(1);
6138 len += strlen(*argv) + 1;
6142 argv = pi->cmds[0].argv;
6144 len = strlen(*argv);
6145 memcpy(p, *argv, len);
6153 static void insert_bg_job(struct pipe *pi)
6155 struct pipe *job, **jobp;
6158 /* Linear search for the ID of the job to use */
6160 for (job = G.job_list; job; job = job->next)
6161 if (job->jobid >= pi->jobid)
6162 pi->jobid = job->jobid + 1;
6164 /* Add job to the list of running jobs */
6166 while ((job = *jobp) != NULL)
6168 job = *jobp = xmalloc(sizeof(*job));
6170 *job = *pi; /* physical copy */
6172 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6173 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6174 for (i = 0; i < pi->num_cmds; i++) {
6175 job->cmds[i].pid = pi->cmds[i].pid;
6176 /* all other fields are not used and stay zero */
6178 job->cmdtext = xstrdup(get_cmdtext(pi));
6180 if (G_interactive_fd)
6181 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6182 G.last_jobid = job->jobid;
6185 static void remove_bg_job(struct pipe *pi)
6187 struct pipe *prev_pipe;
6189 if (pi == G.job_list) {
6190 G.job_list = pi->next;
6192 prev_pipe = G.job_list;
6193 while (prev_pipe->next != pi)
6194 prev_pipe = prev_pipe->next;
6195 prev_pipe->next = pi->next;
6198 G.last_jobid = G.job_list->jobid;
6203 /* Remove a backgrounded job */
6204 static void delete_finished_bg_job(struct pipe *pi)
6211 /* Check to see if any processes have exited -- if they
6212 * have, figure out why and see if a job has completed */
6213 static int checkjobs(struct pipe *fg_pipe)
6223 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6225 attributes = WUNTRACED;
6226 if (fg_pipe == NULL)
6227 attributes |= WNOHANG;
6230 #if ENABLE_HUSH_FAST
6231 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6232 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6233 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6234 /* There was neither fork nor SIGCHLD since last waitpid */
6235 /* Avoid doing waitpid syscall if possible */
6236 if (!G.we_have_children) {
6240 if (fg_pipe == NULL) { /* is WNOHANG set? */
6241 /* We have children, but they did not exit
6242 * or stop yet (we saw no SIGCHLD) */
6245 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6249 /* Do we do this right?
6250 * bash-3.00# sleep 20 | false
6252 * [3]+ Stopped sleep 20 | false
6253 * bash-3.00# echo $?
6254 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6255 * [hush 1.14.0: yes we do it right]
6262 #if ENABLE_HUSH_FAST
6263 i = G.count_SIGCHLD;
6265 childpid = waitpid(-1, &status, attributes);
6266 if (childpid <= 0) {
6267 if (childpid && errno != ECHILD)
6268 bb_perror_msg("waitpid");
6269 #if ENABLE_HUSH_FAST
6270 else { /* Until next SIGCHLD, waitpid's are useless */
6271 G.we_have_children = (childpid == 0);
6272 G.handled_SIGCHLD = i;
6273 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6278 dead = WIFEXITED(status) || WIFSIGNALED(status);
6281 if (WIFSTOPPED(status))
6282 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6283 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6284 if (WIFSIGNALED(status))
6285 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6286 childpid, WTERMSIG(status), WEXITSTATUS(status));
6287 if (WIFEXITED(status))
6288 debug_printf_jobs("pid %d exited, exitcode %d\n",
6289 childpid, WEXITSTATUS(status));
6291 /* Were we asked to wait for fg pipe? */
6293 for (i = 0; i < fg_pipe->num_cmds; i++) {
6294 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6295 if (fg_pipe->cmds[i].pid != childpid)
6298 fg_pipe->cmds[i].pid = 0;
6299 fg_pipe->alive_cmds--;
6300 if (i == fg_pipe->num_cmds - 1) {
6301 /* last process gives overall exitstatus */
6302 rcode = WEXITSTATUS(status);
6303 /* bash prints killer signal's name for *last*
6304 * process in pipe (prints just newline for SIGINT).
6305 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6307 if (WIFSIGNALED(status)) {
6308 int sig = WTERMSIG(status);
6309 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
6310 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6311 * Maybe we need to use sig | 128? */
6314 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6317 fg_pipe->cmds[i].is_stopped = 1;
6318 fg_pipe->stopped_cmds++;
6320 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6321 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6322 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
6323 /* All processes in fg pipe have exited or stopped */
6324 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6325 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6326 * and "killall -STOP cat" */
6327 if (G_interactive_fd) {
6329 if (fg_pipe->alive_cmds)
6330 insert_bg_job(fg_pipe);
6334 if (!fg_pipe->alive_cmds)
6337 /* There are still running processes in the fg pipe */
6338 goto wait_more; /* do waitpid again */
6340 /* it wasnt fg_pipe, look for process in bg pipes */
6344 /* We asked to wait for bg or orphaned children */
6345 /* No need to remember exitcode in this case */
6346 for (pi = G.job_list; pi; pi = pi->next) {
6347 for (i = 0; i < pi->num_cmds; i++) {
6348 if (pi->cmds[i].pid == childpid)
6349 goto found_pi_and_prognum;
6352 /* Happens when shell is used as init process (init=/bin/sh) */
6353 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6354 continue; /* do waitpid again */
6356 found_pi_and_prognum:
6359 pi->cmds[i].pid = 0;
6361 if (!pi->alive_cmds) {
6362 if (G_interactive_fd)
6363 printf(JOB_STATUS_FORMAT, pi->jobid,
6364 "Done", pi->cmdtext);
6365 delete_finished_bg_job(pi);
6369 pi->cmds[i].is_stopped = 1;
6373 } /* while (waitpid succeeds)... */
6379 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6382 int rcode = checkjobs(fg_pipe);
6383 if (G_saved_tty_pgrp) {
6384 /* Job finished, move the shell to the foreground */
6385 p = getpgrp(); /* our process group id */
6386 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6387 tcsetpgrp(G_interactive_fd, p);
6393 /* Start all the jobs, but don't wait for anything to finish.
6396 * Return code is normally -1, when the caller has to wait for children
6397 * to finish to determine the exit status of the pipe. If the pipe
6398 * is a simple builtin command, however, the action is done by the
6399 * time run_pipe returns, and the exit code is provided as the
6402 * Returns -1 only if started some children. IOW: we have to
6403 * mask out retvals of builtins etc with 0xff!
6405 * The only case when we do not need to [v]fork is when the pipe
6406 * is single, non-backgrounded, non-subshell command. Examples:
6407 * cmd ; ... { list } ; ...
6408 * cmd && ... { list } && ...
6409 * cmd || ... { list } || ...
6410 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
6411 * or (if SH_STANDALONE) an applet, and we can run the { list }
6412 * with run_list. If it isn't one of these, we fork and exec cmd.
6414 * Cases when we must fork:
6415 * non-single: cmd | cmd
6416 * backgrounded: cmd & { list } &
6417 * subshell: ( list ) [&]
6419 #if !ENABLE_HUSH_MODE_X
6420 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, char argv_expanded) \
6421 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6423 static int redirect_and_varexp_helper(char ***new_env_p,
6424 struct variable **old_vars_p,
6425 struct command *command,
6427 char **argv_expanded)
6429 /* setup_redirects acts on file descriptors, not FILEs.
6430 * This is perfect for work that comes after exec().
6431 * Is it really safe for inline use? Experimentally,
6432 * things seem to work. */
6433 int rcode = setup_redirects(command, squirrel);
6435 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6436 *new_env_p = new_env;
6437 dump_cmd_in_x_mode(new_env);
6438 dump_cmd_in_x_mode(argv_expanded);
6440 *old_vars_p = set_vars_and_save_old(new_env);
6444 static NOINLINE int run_pipe(struct pipe *pi)
6446 static const char *const null_ptr = NULL;
6450 struct command *command;
6451 char **argv_expanded;
6453 /* it is not always needed, but we aim to smaller code */
6454 int squirrel[] = { -1, -1, -1 };
6457 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6460 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6461 * Result should be 3 lines: q w e, qwe, q w e
6463 G.ifs = get_local_var_value("IFS");
6467 IF_HUSH_JOB(pi->pgrp = -1;)
6468 pi->stopped_cmds = 0;
6469 command = &pi->cmds[0];
6470 argv_expanded = NULL;
6472 if (pi->num_cmds != 1
6473 || pi->followup == PIPE_BG
6474 || command->cmd_type == CMD_SUBSHELL
6481 debug_printf_exec(": group:%p argv:'%s'\n",
6482 command->group, command->argv ? command->argv[0] : "NONE");
6484 if (command->group) {
6485 #if ENABLE_HUSH_FUNCTIONS
6486 if (command->cmd_type == CMD_FUNCDEF) {
6487 /* "executing" func () { list } */
6488 struct function *funcp;
6490 funcp = new_function(command->argv[0]);
6491 /* funcp->name is already set to argv[0] */
6492 funcp->body = command->group;
6494 funcp->body_as_string = command->group_as_string;
6495 command->group_as_string = NULL;
6497 command->group = NULL;
6498 command->argv[0] = NULL;
6499 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6500 funcp->parent_cmd = command;
6501 command->child_func = funcp;
6503 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6505 return EXIT_SUCCESS;
6509 debug_printf("non-subshell group\n");
6510 rcode = 1; /* exitcode if redir failed */
6511 if (setup_redirects(command, squirrel) == 0) {
6512 debug_printf_exec(": run_list\n");
6513 rcode = run_list(command->group) & 0xff;
6515 restore_redirects(squirrel);
6516 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6518 debug_printf_exec("run_pipe: return %d\n", rcode);
6522 argv = command->argv ? command->argv : (char **) &null_ptr;
6524 const struct built_in_command *x;
6525 #if ENABLE_HUSH_FUNCTIONS
6526 const struct function *funcp;
6530 char **new_env = NULL;
6531 struct variable *old_vars = NULL;
6533 if (argv[command->assignment_cnt] == NULL) {
6534 /* Assignments, but no command */
6535 /* Ensure redirects take effect (that is, create files).
6536 * Try "a=t >file" */
6537 #if 0 /* A few cases in testsuite fail with this code. FIXME */
6538 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
6539 /* Set shell variables */
6543 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6544 /* Do we need to flag set_local_var() errors?
6545 * "assignment to readonly var" and "putenv error"
6550 /* Redirect error sets $? to 1. Otherwise,
6551 * if evaluating assignment value set $?, retain it.
6552 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6554 rcode = G.last_exitcode;
6555 /* Exit, _skipping_ variable restoring code: */
6556 goto clean_up_and_ret0;
6558 #else /* Older, bigger, but more correct code */
6560 rcode = setup_redirects(command, squirrel);
6561 restore_redirects(squirrel);
6562 /* Set shell variables */
6564 bb_putchar_stderr('+');
6566 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
6568 fprintf(stderr, " %s", p);
6569 debug_printf_exec("set shell var:'%s'->'%s'\n",
6571 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6572 /* Do we need to flag set_local_var() errors?
6573 * "assignment to readonly var" and "putenv error"
6578 bb_putchar_stderr('\n');
6579 /* Redirect error sets $? to 1. Otherwise,
6580 * if evaluating assignment value set $?, retain it.
6581 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6583 rcode = G.last_exitcode;
6584 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6586 debug_printf_exec("run_pipe: return %d\n", rcode);
6591 /* Expand the rest into (possibly) many strings each */
6593 #if ENABLE_HUSH_BASH_COMPAT
6594 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
6595 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
6599 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
6602 /* if someone gives us an empty string: `cmd with empty output` */
6603 if (!argv_expanded[0]) {
6604 free(argv_expanded);
6606 return G.last_exitcode;
6609 x = find_builtin(argv_expanded[0]);
6610 #if ENABLE_HUSH_FUNCTIONS
6613 funcp = find_function(argv_expanded[0]);
6617 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
6618 debug_printf("exec with redirects only\n");
6619 rcode = setup_redirects(command, NULL);
6620 goto clean_up_and_ret1;
6623 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6626 debug_printf_exec(": builtin '%s' '%s'...\n",
6627 x->b_cmd, argv_expanded[1]);
6628 rcode = x->b_function(argv_expanded) & 0xff;
6631 #if ENABLE_HUSH_FUNCTIONS
6633 # if ENABLE_HUSH_LOCAL
6634 struct variable **sv;
6635 sv = G.shadowed_vars_pp;
6636 G.shadowed_vars_pp = &old_vars;
6638 debug_printf_exec(": function '%s' '%s'...\n",
6639 funcp->name, argv_expanded[1]);
6640 rcode = run_function(funcp, argv_expanded) & 0xff;
6641 # if ENABLE_HUSH_LOCAL
6642 G.shadowed_vars_pp = sv;
6648 unset_vars(new_env);
6650 /* clean_up_and_ret0: */
6651 restore_redirects(squirrel);
6653 free(argv_expanded);
6654 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6656 debug_printf_exec("run_pipe return %d\n", rcode);
6660 if (ENABLE_FEATURE_SH_STANDALONE) {
6661 int n = find_applet_by_name(argv_expanded[0]);
6662 if (n >= 0 && APPLET_IS_NOFORK(n)) {
6663 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6665 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
6666 argv_expanded[0], argv_expanded[1]);
6667 rcode = run_nofork_applet(n, argv_expanded);
6669 goto clean_up_and_ret;
6672 /* It is neither builtin nor applet. We must fork. */
6676 /* NB: argv_expanded may already be created, and that
6677 * might include `cmd` runs! Do not rerun it! We *must*
6678 * use argv_expanded if it's non-NULL */
6680 /* Going to fork a child per each pipe member */
6685 while (cmd_no < pi->num_cmds) {
6686 struct fd_pair pipefds;
6688 volatile nommu_save_t nommu_save;
6689 nommu_save.new_env = NULL;
6690 nommu_save.old_vars = NULL;
6691 nommu_save.argv = NULL;
6692 nommu_save.argv_from_re_execing = NULL;
6694 command = &pi->cmds[cmd_no];
6696 if (command->argv) {
6697 debug_printf_exec(": pipe member '%s' '%s'...\n",
6698 command->argv[0], command->argv[1]);
6700 debug_printf_exec(": pipe member with no argv\n");
6703 /* pipes are inserted between pairs of commands */
6706 if (cmd_no < pi->num_cmds)
6707 xpiped_pair(pipefds);
6709 command->pid = BB_MMU ? fork() : vfork();
6710 if (!command->pid) { /* child */
6712 disable_restore_tty_pgrp_on_exit();
6713 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6715 /* Every child adds itself to new process group
6716 * with pgid == pid_of_first_child_in_pipe */
6717 if (G.run_list_level == 1 && G_interactive_fd) {
6720 if (pgrp < 0) /* true for 1st process only */
6722 if (setpgid(0, pgrp) == 0
6723 && pi->followup != PIPE_BG
6724 && G_saved_tty_pgrp /* we have ctty */
6726 /* We do it in *every* child, not just first,
6728 tcsetpgrp(G_interactive_fd, pgrp);
6732 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
6733 /* 1st cmd in backgrounded pipe
6734 * should have its stdin /dev/null'ed */
6736 if (open(bb_dev_null, O_RDONLY))
6737 xopen("/", O_RDONLY);
6739 xmove_fd(next_infd, 0);
6741 xmove_fd(pipefds.wr, 1);
6744 /* Like bash, explicit redirects override pipes,
6745 * and the pipe fd is available for dup'ing. */
6746 if (setup_redirects(command, NULL))
6749 /* Restore default handlers just prior to exec */
6750 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
6752 /* Stores to nommu_save list of env vars putenv'ed
6753 * (NOMMU, on MMU we don't need that) */
6754 /* cast away volatility... */
6755 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
6756 /* pseudo_exec() does not return */
6759 /* parent or error */
6760 #if ENABLE_HUSH_FAST
6762 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6764 enable_restore_tty_pgrp_on_exit();
6766 /* Clean up after vforked child */
6767 free(nommu_save.argv);
6768 free(nommu_save.argv_from_re_execing);
6769 unset_vars(nommu_save.new_env);
6770 add_vars(nommu_save.old_vars);
6772 free(argv_expanded);
6773 argv_expanded = NULL;
6774 if (command->pid < 0) { /* [v]fork failed */
6775 /* Clearly indicate, was it fork or vfork */
6776 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
6780 /* Second and next children need to know pid of first one */
6782 pi->pgrp = command->pid;
6788 if (cmd_no < pi->num_cmds)
6790 /* Pass read (output) pipe end to next iteration */
6791 next_infd = pipefds.rd;
6794 if (!pi->alive_cmds) {
6796 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
6801 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
6805 #ifndef debug_print_tree
6806 static void debug_print_tree(struct pipe *pi, int lvl)
6808 static const char *const PIPE[] = {
6814 static const char *RES[] = {
6815 [RES_NONE ] = "NONE" ,
6818 [RES_THEN ] = "THEN" ,
6819 [RES_ELIF ] = "ELIF" ,
6820 [RES_ELSE ] = "ELSE" ,
6823 # if ENABLE_HUSH_LOOPS
6824 [RES_FOR ] = "FOR" ,
6825 [RES_WHILE] = "WHILE",
6826 [RES_UNTIL] = "UNTIL",
6828 [RES_DONE ] = "DONE" ,
6830 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
6833 # if ENABLE_HUSH_CASE
6834 [RES_CASE ] = "CASE" ,
6835 [RES_CASE_IN ] = "CASE_IN" ,
6836 [RES_MATCH] = "MATCH",
6837 [RES_CASE_BODY] = "CASE_BODY",
6838 [RES_ESAC ] = "ESAC" ,
6840 [RES_XXXX ] = "XXXX" ,
6841 [RES_SNTX ] = "SNTX" ,
6843 static const char *const CMDTYPE[] = {
6847 # if ENABLE_HUSH_FUNCTIONS
6856 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
6857 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
6859 while (prn < pi->num_cmds) {
6860 struct command *command = &pi->cmds[prn];
6861 char **argv = command->argv;
6863 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
6865 command->assignment_cnt);
6866 if (command->group) {
6867 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
6868 CMDTYPE[command->cmd_type],
6871 , " group_as_string:", command->group_as_string
6876 debug_print_tree(command->group, lvl+1);
6880 if (argv) while (*argv) {
6881 fprintf(stderr, " '%s'", *argv);
6884 fprintf(stderr, "\n");
6891 #endif /* debug_print_tree */
6893 /* NB: called by pseudo_exec, and therefore must not modify any
6894 * global data until exec/_exit (we can be a child after vfork!) */
6895 static int run_list(struct pipe *pi)
6897 #if ENABLE_HUSH_CASE
6898 char *case_word = NULL;
6900 #if ENABLE_HUSH_LOOPS
6901 struct pipe *loop_top = NULL;
6902 char **for_lcur = NULL;
6903 char **for_list = NULL;
6905 smallint last_followup;
6907 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
6908 smalluint cond_code = 0;
6910 enum { cond_code = 0 };
6913 smallint rword; /* RES_foo */
6914 smallint last_rword; /* ditto */
6917 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
6920 #if ENABLE_HUSH_LOOPS
6921 /* Check syntax for "for" */
6922 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
6923 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
6925 /* current word is FOR or IN (BOLD in comments below) */
6926 if (cpipe->next == NULL) {
6927 syntax_error("malformed for");
6929 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
6932 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
6933 if (cpipe->next->res_word == RES_DO)
6935 /* next word is not "do". It must be "in" then ("FOR v in ...") */
6936 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
6937 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
6939 syntax_error("malformed for");
6941 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
6947 /* Past this point, all code paths should jump to ret: label
6948 * in order to return, no direct "return" statements please.
6949 * This helps to ensure that no memory is leaked. */
6957 last_rword = RES_XXXX;
6959 last_followup = PIPE_SEQ;
6960 rcode = G.last_exitcode;
6962 /* Go through list of pipes, (maybe) executing them. */
6963 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
6967 IF_HAS_KEYWORDS(rword = pi->res_word;)
6968 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
6969 rword, cond_code, last_rword);
6970 #if ENABLE_HUSH_LOOPS
6971 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
6972 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
6974 /* start of a loop: remember where loop starts */
6979 /* Still in the same "if...", "then..." or "do..." branch? */
6980 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
6981 if ((rcode == 0 && last_followup == PIPE_OR)
6982 || (rcode != 0 && last_followup == PIPE_AND)
6984 /* It is "<true> || CMD" or "<false> && CMD"
6985 * and we should not execute CMD */
6986 debug_printf_exec("skipped cmd because of || or &&\n");
6987 last_followup = pi->followup;
6991 last_followup = pi->followup;
6992 IF_HAS_KEYWORDS(last_rword = rword;)
6995 if (rword == RES_THEN) {
6996 /* if false; then ... fi has exitcode 0! */
6997 G.last_exitcode = rcode = EXIT_SUCCESS;
6998 /* "if <false> THEN cmd": skip cmd */
7002 if (rword == RES_ELSE || rword == RES_ELIF) {
7003 /* "if <true> then ... ELSE/ELIF cmd":
7004 * skip cmd and all following ones */
7009 #if ENABLE_HUSH_LOOPS
7010 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7012 /* first loop through for */
7014 static const char encoded_dollar_at[] ALIGN1 = {
7015 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7016 }; /* encoded representation of "$@" */
7017 static const char *const encoded_dollar_at_argv[] = {
7018 encoded_dollar_at, NULL
7019 }; /* argv list with one element: "$@" */
7022 vals = (char**)encoded_dollar_at_argv;
7023 if (pi->next->res_word == RES_IN) {
7024 /* if no variable values after "in" we skip "for" */
7025 if (!pi->next->cmds[0].argv) {
7026 G.last_exitcode = rcode = EXIT_SUCCESS;
7027 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7030 vals = pi->next->cmds[0].argv;
7031 } /* else: "for var; do..." -> assume "$@" list */
7032 /* create list of variable values */
7033 debug_print_strings("for_list made from", vals);
7034 for_list = expand_strvec_to_strvec(vals);
7035 for_lcur = for_list;
7036 debug_print_strings("for_list", for_list);
7039 /* "for" loop is over, clean up */
7045 /* Insert next value from for_lcur */
7046 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7047 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7050 if (rword == RES_IN) {
7051 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7053 if (rword == RES_DONE) {
7054 continue; /* "done" has no cmds too */
7057 #if ENABLE_HUSH_CASE
7058 if (rword == RES_CASE) {
7059 case_word = expand_strvec_to_string(pi->cmds->argv);
7062 if (rword == RES_MATCH) {
7065 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7067 /* all prev words didn't match, does this one match? */
7068 argv = pi->cmds->argv;
7070 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7071 /* TODO: which FNM_xxx flags to use? */
7072 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7074 if (cond_code == 0) { /* match! we will execute this branch */
7075 free(case_word); /* make future "word)" stop */
7083 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7085 continue; /* not matched yet, skip this pipe */
7088 /* Just pressing <enter> in shell should check for jobs.
7089 * OTOH, in non-interactive shell this is useless
7090 * and only leads to extra job checks */
7091 if (pi->num_cmds == 0) {
7092 if (G_interactive_fd)
7093 goto check_jobs_and_continue;
7097 /* After analyzing all keywords and conditions, we decided
7098 * to execute this pipe. NB: have to do checkjobs(NULL)
7099 * after run_pipe to collect any background children,
7100 * even if list execution is to be stopped. */
7101 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7104 #if ENABLE_HUSH_LOOPS
7105 G.flag_break_continue = 0;
7107 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7109 /* We ran a builtin, function, or group.
7110 * rcode is already known
7111 * and we don't need to wait for anything. */
7112 G.last_exitcode = rcode;
7113 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7114 check_and_run_traps(0);
7115 #if ENABLE_HUSH_LOOPS
7116 /* Was it "break" or "continue"? */
7117 if (G.flag_break_continue) {
7118 smallint fbc = G.flag_break_continue;
7119 /* We might fall into outer *loop*,
7120 * don't want to break it too */
7122 G.depth_break_continue--;
7123 if (G.depth_break_continue == 0)
7124 G.flag_break_continue = 0;
7125 /* else: e.g. "continue 2" should *break* once, *then* continue */
7126 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7127 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
7128 goto check_jobs_and_break;
7129 /* "continue": simulate end of loop */
7134 #if ENABLE_HUSH_FUNCTIONS
7135 if (G.flag_return_in_progress == 1) {
7136 /* same as "goto check_jobs_and_break" */
7141 } else if (pi->followup == PIPE_BG) {
7142 /* What does bash do with attempts to background builtins? */
7143 /* even bash 3.2 doesn't do that well with nested bg:
7144 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7145 * I'm NOT treating inner &'s as jobs */
7146 check_and_run_traps(0);
7148 if (G.run_list_level == 1)
7151 /* Last command's pid goes to $! */
7152 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7153 G.last_exitcode = rcode = EXIT_SUCCESS;
7154 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7157 if (G.run_list_level == 1 && G_interactive_fd) {
7158 /* Waits for completion, then fg's main shell */
7159 rcode = checkjobs_and_fg_shell(pi);
7160 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7161 check_and_run_traps(0);
7164 { /* This one just waits for completion */
7165 rcode = checkjobs(pi);
7166 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7167 check_and_run_traps(0);
7169 G.last_exitcode = rcode;
7173 /* Analyze how result affects subsequent commands */
7175 if (rword == RES_IF || rword == RES_ELIF)
7178 #if ENABLE_HUSH_LOOPS
7179 /* Beware of "while false; true; do ..."! */
7180 if (pi->next && pi->next->res_word == RES_DO) {
7181 if (rword == RES_WHILE) {
7183 /* "while false; do...done" - exitcode 0 */
7184 G.last_exitcode = rcode = EXIT_SUCCESS;
7185 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7186 goto check_jobs_and_break;
7189 if (rword == RES_UNTIL) {
7191 debug_printf_exec(": until expr is true: breaking\n");
7192 check_jobs_and_break:
7200 check_jobs_and_continue:
7207 #if ENABLE_HUSH_LOOPS
7212 #if ENABLE_HUSH_CASE
7216 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7220 /* Select which version we will use */
7221 static int run_and_free_list(struct pipe *pi)
7224 debug_printf_exec("run_and_free_list entered\n");
7226 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7227 rcode = run_list(pi);
7229 /* free_pipe_list has the side effect of clearing memory.
7230 * In the long run that function can be merged with run_list,
7231 * but doing that now would hobble the debugging effort. */
7233 debug_printf_exec("run_and_free_list return %d\n", rcode);
7238 /* Called a few times only (or even once if "sh -c") */
7239 static void init_sigmasks(void)
7243 sigset_t old_blocked_set;
7245 if (!G.inherited_set_is_saved) {
7246 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
7247 G.inherited_set = G.blocked_set;
7249 old_blocked_set = G.blocked_set;
7251 mask = (1 << SIGQUIT);
7252 if (G_interactive_fd) {
7253 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
7254 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7255 mask |= SPECIAL_JOB_SIGS;
7257 G.non_DFL_mask = mask;
7262 sigaddset(&G.blocked_set, sig);
7266 sigdelset(&G.blocked_set, SIGCHLD);
7268 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
7269 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7271 /* POSIX allows shell to re-enable SIGCHLD
7272 * even if it was SIG_IGN on entry */
7273 #if ENABLE_HUSH_FAST
7274 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7275 if (!G.inherited_set_is_saved)
7276 signal(SIGCHLD, SIGCHLD_handler);
7278 if (!G.inherited_set_is_saved)
7279 signal(SIGCHLD, SIG_DFL);
7282 G.inherited_set_is_saved = 1;
7287 static void maybe_set_to_sigexit(int sig)
7289 void (*handler)(int);
7290 /* non_DFL_mask'ed signals are, well, masked,
7291 * no need to set handler for them.
7293 if (!((G.non_DFL_mask >> sig) & 1)) {
7294 handler = signal(sig, sigexit);
7295 if (handler == SIG_IGN) /* oops... restore back to IGN! */
7296 signal(sig, handler);
7299 /* Set handlers to restore tty pgrp and exit */
7300 static void set_fatal_handlers(void)
7302 /* We _must_ restore tty pgrp on fatal signals */
7304 maybe_set_to_sigexit(SIGILL );
7305 maybe_set_to_sigexit(SIGFPE );
7306 maybe_set_to_sigexit(SIGBUS );
7307 maybe_set_to_sigexit(SIGSEGV);
7308 maybe_set_to_sigexit(SIGTRAP);
7309 } /* else: hush is perfect. what SEGV? */
7310 maybe_set_to_sigexit(SIGABRT);
7311 /* bash 3.2 seems to handle these just like 'fatal' ones */
7312 maybe_set_to_sigexit(SIGPIPE);
7313 maybe_set_to_sigexit(SIGALRM);
7314 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
7315 * if we aren't interactive... but in this case
7316 * we never want to restore pgrp on exit, and this fn is not called */
7317 /*maybe_set_to_sigexit(SIGHUP );*/
7318 /*maybe_set_to_sigexit(SIGTERM);*/
7319 /*maybe_set_to_sigexit(SIGINT );*/
7323 static int set_mode(const char cstate, const char mode)
7325 int state = (cstate == '-' ? 1 : 0);
7327 case 'n': G.n_mode = state; break;
7328 case 'x': IF_HUSH_MODE_X(G_x_mode = state;) break;
7329 default: return EXIT_FAILURE;
7331 return EXIT_SUCCESS;
7334 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7335 int hush_main(int argc, char **argv)
7338 unsigned builtin_argc;
7340 struct variable *cur_var;
7343 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
7344 G.last_exitcode = EXIT_SUCCESS;
7346 G.argv0_for_re_execing = argv[0];
7348 /* Deal with HUSH_VERSION */
7349 G.shell_ver.flg_export = 1;
7350 G.shell_ver.flg_read_only = 1;
7351 /* Code which handles ${var<op>...} needs writable values for all variables,
7352 * therefore we xstrdup: */
7353 G.shell_ver.varstr = xstrdup(hush_version_str),
7354 G.top_var = &G.shell_ver;
7355 /* Create shell local variables from the values
7356 * currently living in the environment */
7357 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7358 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7359 cur_var = G.top_var;
7362 char *value = strchr(*e, '=');
7363 if (value) { /* paranoia */
7364 cur_var->next = xzalloc(sizeof(*cur_var));
7365 cur_var = cur_var->next;
7366 cur_var->varstr = *e;
7367 cur_var->max_len = strlen(*e);
7368 cur_var->flg_export = 1;
7372 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7373 debug_printf_env("putenv '%s'\n", G.shell_ver.varstr);
7374 putenv(G.shell_ver.varstr);
7377 set_pwd_var(/*exp:*/ 1);
7378 /* bash also exports SHLVL and _,
7379 * and sets (but doesn't export) the following variables:
7381 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7382 * BASH_VERSION='3.2.0(1)-release'
7384 * MACHTYPE=i386-pc-linux-gnu
7386 * HOSTNAME=<xxxxxxxxxx>
7387 * PPID=<NNNNN> - we also do it elsewhere
7398 * PIPESTATUS=([0]="0")
7399 * HISTFILE=/<xxx>/.bash_history
7403 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7405 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7415 #if ENABLE_FEATURE_EDITING
7416 G.line_input_state = new_line_input_t(FOR_SHELL);
7418 G.global_argc = argc;
7419 G.global_argv = argv;
7420 /* Initialize some more globals to non-zero values */
7421 cmdedit_update_prompt();
7423 if (setjmp(die_jmp)) {
7424 /* xfunc has failed! die die die */
7425 /* no EXIT traps, this is an escape hatch! */
7427 hush_exit(xfunc_error_retval);
7430 /* Shell is non-interactive at first. We need to call
7431 * init_sigmasks() if we are going to execute "sh <script>",
7432 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7433 * If we later decide that we are interactive, we run init_sigmasks()
7434 * in order to intercept (more) signals.
7438 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7441 opt = getopt(argc, argv, "+c:xins"
7444 # if ENABLE_HUSH_FUNCTIONS
7454 * sh ... -c 'script'
7455 * sh ... -c 'script' ARG0 [ARG1...]
7456 * On NOMMU, if builtin_argc != 0,
7457 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7458 * "" needs to be replaced with NULL
7459 * and BARGV vector fed to builtin function.
7460 * Note: the form without ARG0 never happens:
7461 * sh ... -c 'builtin' BARGV... ""
7464 G.root_pid = getpid();
7465 G.root_ppid = getppid();
7467 G.global_argv = argv + optind;
7468 G.global_argc = argc - optind;
7470 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7471 const struct built_in_command *x;
7474 x = find_builtin(optarg);
7475 if (x) { /* paranoia */
7476 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7477 G.global_argv += builtin_argc;
7478 G.global_argv[-1] = NULL; /* replace "" */
7479 G.last_exitcode = x->b_function(argv + optind - 1);
7483 if (!G.global_argv[0]) {
7484 /* -c 'script' (no params): prevent empty $0 */
7485 G.global_argv--; /* points to argv[i] of 'script' */
7486 G.global_argv[0] = argv[0];
7488 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7490 parse_and_run_string(optarg);
7493 /* Well, we cannot just declare interactiveness,
7494 * we have to have some stuff (ctty, etc) */
7495 /* G_interactive_fd++; */
7498 /* "-s" means "read from stdin", but this is how we always
7499 * operate, so simply do nothing here. */
7502 case '<': /* "big heredoc" support */
7503 full_write1_str(optarg);
7506 unsigned long long empty_trap_mask;
7508 G.root_pid = bb_strtou(optarg, &optarg, 16);
7510 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7512 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7514 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7516 builtin_argc = bb_strtou(optarg, &optarg, 16);
7518 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7519 if (empty_trap_mask != 0) {
7522 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7523 for (sig = 1; sig < NSIG; sig++) {
7524 if (empty_trap_mask & (1LL << sig)) {
7525 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7526 sigaddset(&G.blocked_set, sig);
7529 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7531 # if ENABLE_HUSH_LOOPS
7533 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7539 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7541 # if ENABLE_HUSH_FUNCTIONS
7543 struct function *funcp = new_function(optarg);
7544 /* funcp->name is already set to optarg */
7545 /* funcp->body is set to NULL. It's a special case. */
7546 funcp->body_as_string = argv[optind];
7554 if (set_mode('-', opt) == 0) /* no error */
7558 fprintf(stderr, "Usage: sh [FILE]...\n"
7559 " or: sh -c command [args]...\n\n");
7565 } /* option parsing loop */
7568 G.root_pid = getpid();
7569 G.root_ppid = getppid();
7572 /* If we are login shell... */
7573 if (argv[0] && argv[0][0] == '-') {
7575 debug_printf("sourcing /etc/profile\n");
7576 input = fopen_for_read("/etc/profile");
7577 if (input != NULL) {
7578 close_on_exec_on(fileno(input));
7580 parse_and_run_file(input);
7583 /* bash: after sourcing /etc/profile,
7584 * tries to source (in the given order):
7585 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7586 * stopping on first found. --noprofile turns this off.
7587 * bash also sources ~/.bash_logout on exit.
7588 * If called as sh, skips .bash_XXX files.
7595 * "bash <script>" (which is never interactive (unless -i?))
7596 * sources $BASH_ENV here (without scanning $PATH).
7597 * If called as sh, does the same but with $ENV.
7599 debug_printf("running script '%s'\n", argv[optind]);
7600 G.global_argv = argv + optind;
7601 G.global_argc = argc - optind;
7602 input = xfopen_for_read(argv[optind]);
7603 close_on_exec_on(fileno(input));
7605 parse_and_run_file(input);
7606 #if ENABLE_FEATURE_CLEAN_UP
7612 /* Up to here, shell was non-interactive. Now it may become one.
7613 * NB: don't forget to (re)run init_sigmasks() as needed.
7616 /* A shell is interactive if the '-i' flag was given,
7617 * or if all of the following conditions are met:
7619 * no arguments remaining or the -s flag given
7620 * standard input is a terminal
7621 * standard output is a terminal
7622 * Refer to Posix.2, the description of the 'sh' utility.
7625 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7626 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7627 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7628 if (G_saved_tty_pgrp < 0)
7629 G_saved_tty_pgrp = 0;
7631 /* try to dup stdin to high fd#, >= 255 */
7632 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7633 if (G_interactive_fd < 0) {
7634 /* try to dup to any fd */
7635 G_interactive_fd = dup(STDIN_FILENO);
7636 if (G_interactive_fd < 0) {
7638 G_interactive_fd = 0;
7639 G_saved_tty_pgrp = 0;
7642 // TODO: track & disallow any attempts of user
7643 // to (inadvertently) close/redirect G_interactive_fd
7645 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7646 if (G_interactive_fd) {
7647 close_on_exec_on(G_interactive_fd);
7649 if (G_saved_tty_pgrp) {
7650 /* If we were run as 'hush &', sleep until we are
7651 * in the foreground (tty pgrp == our pgrp).
7652 * If we get started under a job aware app (like bash),
7653 * make sure we are now in charge so we don't fight over
7654 * who gets the foreground */
7656 pid_t shell_pgrp = getpgrp();
7657 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7658 if (G_saved_tty_pgrp == shell_pgrp)
7660 /* send TTIN to ourself (should stop us) */
7661 kill(- shell_pgrp, SIGTTIN);
7665 /* Block some signals */
7668 if (G_saved_tty_pgrp) {
7669 /* Set other signals to restore saved_tty_pgrp */
7670 set_fatal_handlers();
7671 /* Put ourselves in our own process group
7672 * (bash, too, does this only if ctty is available) */
7673 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7674 /* Grab control of the terminal */
7675 tcsetpgrp(G_interactive_fd, getpid());
7677 /* -1 is special - makes xfuncs longjmp, not exit
7678 * (we reset die_sleep = 0 whereever we [v]fork) */
7679 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7683 #elif ENABLE_HUSH_INTERACTIVE
7684 /* No job control compiled in, only prompt/line editing */
7685 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7686 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7687 if (G_interactive_fd < 0) {
7688 /* try to dup to any fd */
7689 G_interactive_fd = dup(STDIN_FILENO);
7690 if (G_interactive_fd < 0)
7692 G_interactive_fd = 0;
7695 if (G_interactive_fd) {
7696 close_on_exec_on(G_interactive_fd);
7700 /* We have interactiveness code disabled */
7704 * if interactive but not a login shell, sources ~/.bashrc
7705 * (--norc turns this off, --rcfile <file> overrides)
7708 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7709 /* note: ash and hush share this string */
7710 printf("\n\n%s %s\n"
7711 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7714 "hush - the humble shell"
7718 parse_and_run_file(stdin);
7721 #if ENABLE_FEATURE_CLEAN_UP
7722 if (G.cwd != bb_msg_unknown)
7724 cur_var = G.top_var->next;
7726 struct variable *tmp = cur_var;
7727 if (!cur_var->max_len)
7728 free(cur_var->varstr);
7729 cur_var = cur_var->next;
7733 hush_exit(G.last_exitcode);
7738 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7739 int msh_main(int argc, char **argv)
7741 //bb_error_msg("msh is deprecated, please use hush instead");
7742 return hush_main(argc, argv);
7750 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7755 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7762 return applet_main_func(argc, argv - argc);
7765 static int FAST_FUNC builtin_test(char **argv)
7767 return run_applet_main(argv, test_main);
7770 static int FAST_FUNC builtin_echo(char **argv)
7772 return run_applet_main(argv, echo_main);
7776 static int FAST_FUNC builtin_printf(char **argv)
7778 return run_applet_main(argv, printf_main);
7782 static char **skip_dash_dash(char **argv)
7785 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7790 static int FAST_FUNC builtin_eval(char **argv)
7792 int rcode = EXIT_SUCCESS;
7794 argv = skip_dash_dash(argv);
7796 char *str = expand_strvec_to_string(argv);
7798 * eval "echo Hi; done" ("done" is syntax error):
7799 * "echo Hi" will not execute too.
7801 parse_and_run_string(str);
7803 rcode = G.last_exitcode;
7808 static int FAST_FUNC builtin_cd(char **argv)
7812 argv = skip_dash_dash(argv);
7814 if (newdir == NULL) {
7815 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7816 * bash says "bash: cd: HOME not set" and does nothing
7819 const char *home = get_local_var_value("HOME");
7820 newdir = home ? home : "/";
7822 if (chdir(newdir)) {
7823 /* Mimic bash message exactly */
7824 bb_perror_msg("cd: %s", newdir);
7825 return EXIT_FAILURE;
7827 /* Read current dir (get_cwd(1) is inside) and set PWD.
7828 * Note: do not enforce exporting. If PWD was unset or unexported,
7829 * set it again, but do not export. bash does the same.
7831 set_pwd_var(/*exp:*/ 0);
7832 return EXIT_SUCCESS;
7835 static int FAST_FUNC builtin_exec(char **argv)
7837 argv = skip_dash_dash(argv);
7838 if (argv[0] == NULL)
7839 return EXIT_SUCCESS; /* bash does this */
7841 /* Careful: we can end up here after [v]fork. Do not restore
7842 * tty pgrp then, only top-level shell process does that */
7843 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7844 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7846 /* TODO: if exec fails, bash does NOT exit! We do.
7847 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7848 * and tcsetpgrp, and this is inherently racy.
7850 execvp_or_die(argv);
7853 static int FAST_FUNC builtin_exit(char **argv)
7855 debug_printf_exec("%s()\n", __func__);
7857 /* interactive bash:
7858 * # trap "echo EEE" EXIT
7861 * There are stopped jobs.
7862 * (if there are _stopped_ jobs, running ones don't count)
7865 # EEE (then bash exits)
7867 * we can use G.exiting = -1 as indicator "last cmd was exit"
7870 /* note: EXIT trap is run by hush_exit */
7871 argv = skip_dash_dash(argv);
7872 if (argv[0] == NULL)
7873 hush_exit(G.last_exitcode);
7874 /* mimic bash: exit 123abc == exit 255 + error msg */
7875 xfunc_error_retval = 255;
7876 /* bash: exit -2 == exit 254, no error msg */
7877 hush_exit(xatoi(argv[0]) & 0xff);
7880 static void print_escaped(const char *s)
7885 const char *p = strchrnul(s, '\'');
7886 /* print 'xxxx', possibly just '' */
7887 printf("'%.*s'", (int)(p - s), s);
7892 /* s points to '; print "'''...'''" */
7894 do putchar('\''); while (*++s == '\'');
7899 #if !ENABLE_HUSH_LOCAL
7900 #define helper_export_local(argv, exp, lvl) \
7901 helper_export_local(argv, exp)
7903 static void helper_export_local(char **argv, int exp, int lvl)
7907 char *name_end = strchrnul(name, '=');
7909 /* So far we do not check that name is valid (TODO?) */
7911 if (*name_end == '\0') {
7912 struct variable *var, **vpp;
7914 vpp = get_ptr_to_local_var(name, name_end - name);
7915 var = vpp ? *vpp : NULL;
7917 if (exp == -1) { /* unexporting? */
7918 /* export -n NAME (without =VALUE) */
7920 var->flg_export = 0;
7921 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7923 } /* else: export -n NOT_EXISTING_VAR: no-op */
7926 if (exp == 1) { /* exporting? */
7927 /* export NAME (without =VALUE) */
7929 var->flg_export = 1;
7930 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7931 putenv(var->varstr);
7935 /* Exporting non-existing variable.
7936 * bash does not put it in environment,
7937 * but remembers that it is exported,
7938 * and does put it in env when it is set later.
7939 * We just set it to "" and export. */
7940 /* Or, it's "local NAME" (without =VALUE).
7941 * bash sets the value to "". */
7942 name = xasprintf("%s=", name);
7944 /* (Un)exporting/making local NAME=VALUE */
7945 name = xstrdup(name);
7947 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7951 static int FAST_FUNC builtin_export(char **argv)
7953 unsigned opt_unexport;
7955 #if ENABLE_HUSH_EXPORT_N
7956 /* "!": do not abort on errors */
7957 opt_unexport = getopt32(argv, "!n");
7958 if (opt_unexport == (uint32_t)-1)
7959 return EXIT_FAILURE;
7966 if (argv[0] == NULL) {
7973 /* ash emits: export VAR='VAL'
7974 * bash: declare -x VAR="VAL"
7975 * we follow ash example */
7976 const char *s = *e++;
7977 const char *p = strchr(s, '=');
7979 if (!p) /* wtf? take next variable */
7982 printf("export %.*s", (int)(p - s) + 1, s);
7983 print_escaped(p + 1);
7987 /*fflush_all(); - done after each builtin anyway */
7989 return EXIT_SUCCESS;
7992 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7994 return EXIT_SUCCESS;
7997 #if ENABLE_HUSH_LOCAL
7998 static int FAST_FUNC builtin_local(char **argv)
8000 if (G.func_nest_level == 0) {
8001 bb_error_msg("%s: not in a function", argv[0]);
8002 return EXIT_FAILURE; /* bash compat */
8004 helper_export_local(argv, 0, G.func_nest_level);
8005 return EXIT_SUCCESS;
8009 static int FAST_FUNC builtin_trap(char **argv)
8015 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8020 /* No args: print all trapped */
8021 for (i = 0; i < NSIG; ++i) {
8024 print_escaped(G.traps[i]);
8025 /* note: bash adds "SIG", but only if invoked
8026 * as "bash". If called as "sh", or if set -o posix,
8027 * then it prints short signal names.
8028 * We are printing short names: */
8029 printf(" %s\n", get_signame(i));
8032 /*fflush_all(); - done after each builtin anyway */
8033 return EXIT_SUCCESS;
8037 /* If first arg is a number: reset all specified signals */
8038 sig = bb_strtou(*argv, NULL, 10);
8044 sig = get_signum(*argv++);
8045 if (sig < 0 || sig >= NSIG) {
8047 /* Mimic bash message exactly */
8048 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8053 G.traps[sig] = xstrdup(new_cmd);
8055 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8056 get_signame(sig), sig, G.traps[sig]);
8058 /* There is no signal for 0 (EXIT) */
8063 sigaddset(&G.blocked_set, sig);
8065 /* There was a trap handler, we are removing it
8066 * (if sig has non-DFL handling,
8067 * we don't need to do anything) */
8068 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
8070 sigdelset(&G.blocked_set, sig);
8073 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8077 if (!argv[1]) { /* no second arg */
8078 bb_error_msg("trap: invalid arguments");
8079 return EXIT_FAILURE;
8082 /* First arg is "-": reset all specified to default */
8083 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8084 /* Everything else: set arg as signal handler
8085 * (includes "" case, which ignores signal) */
8086 if (argv[0][0] == '-') {
8087 if (argv[0][1] == '\0') { /* "-" */
8088 /* new_cmd remains NULL: "reset these sigs" */
8091 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8094 /* else: "-something", no special meaning */
8099 goto process_sig_list;
8102 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8103 static int FAST_FUNC builtin_type(char **argv)
8105 int ret = EXIT_SUCCESS;
8111 if (0) {} /* make conditional compile easier below */
8112 /*else if (find_alias(*argv))
8113 type = "an alias";*/
8114 #if ENABLE_HUSH_FUNCTIONS
8115 else if (find_function(*argv))
8116 type = "a function";
8118 else if (find_builtin(*argv))
8119 type = "a shell builtin";
8120 else if ((path = find_in_path(*argv)) != NULL)
8123 bb_error_msg("type: %s: not found", *argv);
8128 printf("%s is %s\n", *argv, type);
8136 /* built-in 'fg' and 'bg' handler */
8137 static int FAST_FUNC builtin_fg_bg(char **argv)
8142 if (!G_interactive_fd)
8143 return EXIT_FAILURE;
8145 /* If they gave us no args, assume they want the last backgrounded task */
8147 for (pi = G.job_list; pi; pi = pi->next) {
8148 if (pi->jobid == G.last_jobid) {
8152 bb_error_msg("%s: no current job", argv[0]);
8153 return EXIT_FAILURE;
8155 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8156 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8157 return EXIT_FAILURE;
8159 for (pi = G.job_list; pi; pi = pi->next) {
8160 if (pi->jobid == jobnum) {
8164 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8165 return EXIT_FAILURE;
8167 /* TODO: bash prints a string representation
8168 * of job being foregrounded (like "sleep 1 | cat") */
8169 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8170 /* Put the job into the foreground. */
8171 tcsetpgrp(G_interactive_fd, pi->pgrp);
8174 /* Restart the processes in the job */
8175 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8176 for (i = 0; i < pi->num_cmds; i++) {
8177 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8178 pi->cmds[i].is_stopped = 0;
8180 pi->stopped_cmds = 0;
8182 i = kill(- pi->pgrp, SIGCONT);
8184 if (errno == ESRCH) {
8185 delete_finished_bg_job(pi);
8186 return EXIT_SUCCESS;
8188 bb_perror_msg("kill (SIGCONT)");
8191 if (argv[0][0] == 'f') {
8193 return checkjobs_and_fg_shell(pi);
8195 return EXIT_SUCCESS;
8199 #if ENABLE_HUSH_HELP
8200 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8202 const struct built_in_command *x;
8205 "Built-in commands:\n"
8206 "------------------\n");
8207 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8209 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8212 return EXIT_SUCCESS;
8217 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8220 const char *status_string;
8222 for (job = G.job_list; job; job = job->next) {
8223 if (job->alive_cmds == job->stopped_cmds)
8224 status_string = "Stopped";
8226 status_string = "Running";
8228 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8230 return EXIT_SUCCESS;
8235 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8240 # ifdef M_TRIM_THRESHOLD
8241 /* Optional. Reduces probability of false positives */
8244 /* Crude attempt to find where "free memory" starts,
8245 * sans fragmentation. */
8247 l = (unsigned long)p;
8250 if (l < (unsigned long)p) l = (unsigned long)p;
8253 if (!G.memleak_value)
8254 G.memleak_value = l;
8256 l -= G.memleak_value;
8263 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8268 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8271 return EXIT_SUCCESS;
8274 static int FAST_FUNC builtin_read(char **argv)
8283 /* "!": do not abort on errors.
8284 * Option string must start with "sr" to match BUILTIN_READ_xxx
8286 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8287 if (read_flags == (uint32_t)-1)
8288 return EXIT_FAILURE;
8291 r = shell_builtin_read(set_local_var_from_halves,
8293 get_local_var_value("IFS"), /* can be NULL */
8301 if ((uintptr_t)r > 1) {
8302 bb_error_msg("%s", r);
8303 r = (char*)(uintptr_t)1;
8306 return (uintptr_t)r;
8309 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8310 * built-in 'set' handler
8312 * set [-abCefhmnuvx] [-o option] [argument...]
8313 * set [+abCefhmnuvx] [+o option] [argument...]
8314 * set -- [argument...]
8317 * Implementations shall support the options in both their hyphen and
8318 * plus-sign forms. These options can also be specified as options to sh.
8320 * Write out all variables and their values: set
8321 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8322 * Turn on the -x and -v options: set -xv
8323 * Unset all positional parameters: set --
8324 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8325 * Set the positional parameters to the expansion of x, even if x expands
8326 * with a leading '-' or '+': set -- $x
8328 * So far, we only support "set -- [argument...]" and some of the short names.
8330 static int FAST_FUNC builtin_set(char **argv)
8333 char **pp, **g_argv;
8334 char *arg = *++argv;
8338 for (e = G.top_var; e; e = e->next)
8340 return EXIT_SUCCESS;
8344 if (!strcmp(arg, "--")) {
8348 if (arg[0] != '+' && arg[0] != '-')
8350 for (n = 1; arg[n]; ++n)
8351 if (set_mode(arg[0], arg[n]))
8353 } while ((arg = *++argv) != NULL);
8354 /* Now argv[0] is 1st argument */
8357 return EXIT_SUCCESS;
8360 /* NB: G.global_argv[0] ($0) is never freed/changed */
8361 g_argv = G.global_argv;
8362 if (G.global_args_malloced) {
8368 G.global_args_malloced = 1;
8369 pp = xzalloc(sizeof(pp[0]) * 2);
8370 pp[0] = g_argv[0]; /* retain $0 */
8373 /* This realloc's G.global_argv */
8374 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8381 return EXIT_SUCCESS;
8383 /* Nothing known, so abort */
8385 bb_error_msg("set: %s: invalid option", arg);
8386 return EXIT_FAILURE;
8389 static int FAST_FUNC builtin_shift(char **argv)
8392 argv = skip_dash_dash(argv);
8396 if (n >= 0 && n < G.global_argc) {
8397 if (G.global_args_malloced) {
8400 free(G.global_argv[m++]);
8403 memmove(&G.global_argv[1], &G.global_argv[n+1],
8404 G.global_argc * sizeof(G.global_argv[0]));
8405 return EXIT_SUCCESS;
8407 return EXIT_FAILURE;
8410 static int FAST_FUNC builtin_source(char **argv)
8412 char *arg_path, *filename;
8415 #if ENABLE_HUSH_FUNCTIONS
8419 argv = skip_dash_dash(argv);
8422 /* bash says: "bash: .: filename argument required" */
8423 return 2; /* bash compat */
8426 if (!strchr(filename, '/')) {
8427 arg_path = find_in_path(filename);
8429 filename = arg_path;
8431 input = fopen_or_warn(filename, "r");
8434 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8435 return EXIT_FAILURE;
8437 close_on_exec_on(fileno(input));
8439 #if ENABLE_HUSH_FUNCTIONS
8440 sv_flg = G.flag_return_in_progress;
8441 /* "we are inside sourced file, ok to use return" */
8442 G.flag_return_in_progress = -1;
8444 save_and_replace_G_args(&sv, argv);
8446 parse_and_run_file(input);
8449 restore_G_args(&sv, argv);
8450 #if ENABLE_HUSH_FUNCTIONS
8451 G.flag_return_in_progress = sv_flg;
8454 return G.last_exitcode;
8457 static int FAST_FUNC builtin_umask(char **argv)
8463 argv = skip_dash_dash(argv);
8465 mode_t old_mask = mask;
8468 rc = bb_parse_mode(argv[0], &mask);
8473 * bash: umask: 'q': invalid symbolic mode operator
8474 * bash: umask: 999: octal number out of range
8476 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8481 printf("%04o\n", (unsigned) mask);
8482 /* fall through and restore mask which we set to 0 */
8486 return !rc; /* rc != 0 - success */
8489 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8490 static int FAST_FUNC builtin_unset(char **argv)
8495 /* "!": do not abort on errors */
8496 /* "+": stop at 1st non-option */
8497 opts = getopt32(argv, "!+vf");
8498 if (opts == (unsigned)-1)
8499 return EXIT_FAILURE;
8501 bb_error_msg("unset: -v and -f are exclusive");
8502 return EXIT_FAILURE;
8508 if (!(opts & 2)) { /* not -f */
8509 if (unset_local_var(*argv)) {
8510 /* unset <nonexistent_var> doesn't fail.
8511 * Error is when one tries to unset RO var.
8512 * Message was printed by unset_local_var. */
8516 #if ENABLE_HUSH_FUNCTIONS
8526 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8527 static int FAST_FUNC builtin_wait(char **argv)
8529 int ret = EXIT_SUCCESS;
8532 argv = skip_dash_dash(argv);
8533 if (argv[0] == NULL) {
8534 /* Don't care about wait results */
8535 /* Note 1: must wait until there are no more children */
8536 /* Note 2: must be interruptible */
8538 * $ sleep 3 & sleep 6 & wait
8543 * $ sleep 3 & sleep 6 & wait
8547 * ^C <-- after ~4 sec from keyboard
8550 sigaddset(&G.blocked_set, SIGCHLD);
8551 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8554 if (errno == ECHILD)
8556 /* Wait for SIGCHLD or any other signal of interest */
8557 /* sigtimedwait with infinite timeout: */
8558 sig = sigwaitinfo(&G.blocked_set, NULL);
8560 sig = check_and_run_traps(sig);
8561 if (sig && sig != SIGCHLD) { /* see note 2 */
8567 sigdelset(&G.blocked_set, SIGCHLD);
8568 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8572 /* This is probably buggy wrt interruptible-ness */
8574 pid_t pid = bb_strtou(*argv, NULL, 10);
8576 /* mimic bash message */
8577 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8578 return EXIT_FAILURE;
8580 if (waitpid(pid, &status, 0) == pid) {
8581 if (WIFSIGNALED(status))
8582 ret = 128 + WTERMSIG(status);
8583 else if (WIFEXITED(status))
8584 ret = WEXITSTATUS(status);
8588 bb_perror_msg("wait %s", *argv);
8597 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8598 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8601 def = bb_strtou(argv[1], NULL, 10);
8602 if (errno || def < def_min || argv[2]) {
8603 bb_error_msg("%s: bad arguments", argv[0]);
8611 #if ENABLE_HUSH_LOOPS
8612 static int FAST_FUNC builtin_break(char **argv)
8615 if (G.depth_of_loop == 0) {
8616 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8617 return EXIT_SUCCESS; /* bash compat */
8619 G.flag_break_continue++; /* BC_BREAK = 1 */
8621 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8622 if (depth == UINT_MAX)
8623 G.flag_break_continue = BC_BREAK;
8624 if (G.depth_of_loop < depth)
8625 G.depth_break_continue = G.depth_of_loop;
8627 return EXIT_SUCCESS;
8630 static int FAST_FUNC builtin_continue(char **argv)
8632 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8633 return builtin_break(argv);
8637 #if ENABLE_HUSH_FUNCTIONS
8638 static int FAST_FUNC builtin_return(char **argv)
8642 if (G.flag_return_in_progress != -1) {
8643 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8644 return EXIT_FAILURE; /* bash compat */
8647 G.flag_return_in_progress = 1;
8650 * out of range: wraps around at 256, does not error out
8651 * non-numeric param:
8652 * f() { false; return qwe; }; f; echo $?
8653 * bash: return: qwe: numeric argument required <== we do this
8654 * 255 <== we also do this
8656 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);