1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
41 * grep for "TODO" and fix (some of them are easy)
42 * special variables (done: PWD, PPID, RANDOM)
45 * follow IFS rules more precisely, including update semantics
46 * builtins mandated by standards we don't support:
47 * [un]alias, command, fc, getopts, newgrp, readonly, times
48 * make complex ${var%...} constructs support optional
49 * make here documents optional
52 * redirection of stdout+stderr: &> and >&
53 * brace expansion: one/{two,three,four}
54 * reserved words: function select
55 * advanced test: [[ ]]
56 * process substitution: <(list) and >(list)
59 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
60 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
61 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
63 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
64 * This is exactly equivalent to let "EXPR".
65 * $[EXPR]: synonym for $((EXPR))
66 * export builtin should be special, its arguments are assignments
67 * and therefore expansion of them should be "one-word" expansion:
68 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
70 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
71 * ls: cannot access i=a: No such file or directory
72 * ls: cannot access b: No such file or directory
73 * Note1: same applies to local builtin.
74 * Note2: bash 3.2.33(1) does this only if export word itself
76 * $ export i=`echo 'aaa bbb'`; echo "$i"
78 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
81 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
83 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
84 #include <malloc.h> /* for malloc_trim */
86 /* #include <dmalloc.h> */
91 #include "shell_common.h"
94 #if ENABLE_HUSH_RANDOM_SUPPORT
97 # define CLEAR_RANDOM_T(rnd) ((void)0)
100 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
103 //applet:IF_HUSH(APPLET(hush, _BB_DIR_BIN, _BB_SUID_DROP))
104 //applet:IF_MSH(APPLET(msh, _BB_DIR_BIN, _BB_SUID_DROP))
105 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, _BB_DIR_BIN, _BB_SUID_DROP, sh))
106 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, _BB_DIR_BIN, _BB_SUID_DROP, bash))
108 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
109 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
112 //config: bool "hush"
115 //config: hush is a small shell (25k). It handles the normal flow control
116 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
117 //config: case/esac. Redirections, here documents, $((arithmetic))
118 //config: and functions are supported.
120 //config: It will compile and work on no-mmu systems.
122 //config: It does not handle select, aliases, brace expansion,
123 //config: tilde expansion, &>file and >&file redirection of stdout+stderr.
125 //config:config HUSH_BASH_COMPAT
126 //config: bool "bash-compatible extensions"
128 //config: depends on HUSH
130 //config: Enable bash-compatible extensions.
132 //config:config HUSH_HELP
133 //config: bool "help builtin"
135 //config: depends on HUSH
137 //config: Enable help builtin in hush. Code size + ~1 kbyte.
139 //config:config HUSH_INTERACTIVE
140 //config: bool "Interactive mode"
142 //config: depends on HUSH
144 //config: Enable interactive mode (prompt and command editing).
145 //config: Without this, hush simply reads and executes commands
146 //config: from stdin just like a shell script from a file.
147 //config: No prompt, no PS1/PS2 magic shell variables.
149 //config:config HUSH_JOB
150 //config: bool "Job control"
152 //config: depends on HUSH_INTERACTIVE
154 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
155 //config: command (not entire shell), fg/bg builtins work. Without this option,
156 //config: "cmd &" still works by simply spawning a process and immediately
157 //config: prompting for next command (or executing next command in a script),
158 //config: but no separate process group is formed.
160 //config:config HUSH_TICK
161 //config: bool "Process substitution"
163 //config: depends on HUSH
165 //config: Enable process substitution `command` and $(command) in hush.
167 //config:config HUSH_IF
168 //config: bool "Support if/then/elif/else/fi"
170 //config: depends on HUSH
172 //config: Enable if/then/elif/else/fi in hush.
174 //config:config HUSH_LOOPS
175 //config: bool "Support for, while and until loops"
177 //config: depends on HUSH
179 //config: Enable for, while and until loops in hush.
181 //config:config HUSH_CASE
182 //config: bool "Support case ... esac statement"
184 //config: depends on HUSH
186 //config: Enable case ... esac statement in hush. +400 bytes.
188 //config:config HUSH_FUNCTIONS
189 //config: bool "Support funcname() { commands; } syntax"
191 //config: depends on HUSH
193 //config: Enable support for shell functions in hush. +800 bytes.
195 //config:config HUSH_LOCAL
196 //config: bool "Support local builtin"
198 //config: depends on HUSH_FUNCTIONS
200 //config: Enable support for local variables in functions.
202 //config:config HUSH_RANDOM_SUPPORT
203 //config: bool "Pseudorandom generator and $RANDOM variable"
205 //config: depends on HUSH
207 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
208 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
210 //config:config HUSH_EXPORT_N
211 //config: bool "Support 'export -n' option"
213 //config: depends on HUSH
215 //config: export -n unexports variables. It is a bash extension.
217 //config:config HUSH_MODE_X
218 //config: bool "Support 'hush -x' option and 'set -x' command"
220 //config: depends on HUSH
222 //config: This instructs hush to print commands before execution.
223 //config: Adds ~300 bytes.
226 //config: bool "msh (deprecated: aliased to hush)"
228 //config: select HUSH
230 //config: msh is deprecated and will be removed, please migrate to hush.
233 //usage:#define hush_trivial_usage NOUSAGE_STR
234 //usage:#define hush_full_usage ""
235 //usage:#define msh_trivial_usage NOUSAGE_STR
236 //usage:#define msh_full_usage ""
240 #define LEAK_HUNTING 0
241 #define BUILD_AS_NOMMU 0
242 /* Enable/disable sanity checks. Ok to enable in production,
243 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
244 * Keeping 1 for now even in released versions.
247 /* Slightly bigger (+200 bytes), but faster hush.
248 * So far it only enables a trick with counting SIGCHLDs and forks,
249 * which allows us to do fewer waitpid's.
250 * (we can detect a case where neither forks were done nor SIGCHLDs happened
251 * and therefore waitpid will return the same result as last time)
253 #define ENABLE_HUSH_FAST 0
254 /* TODO: implement simplified code for users which do not need ${var%...} ops
255 * So far ${var%...} ops are always enabled:
257 #define ENABLE_HUSH_DOLLAR_OPS 1
262 # undef USE_FOR_NOMMU
265 # define USE_FOR_NOMMU(...) __VA_ARGS__
266 # define USE_FOR_MMU(...)
269 #include "NUM_APPLETS.h"
271 /* STANDALONE does not make sense, and won't compile */
272 # undef CONFIG_FEATURE_SH_STANDALONE
273 # undef ENABLE_FEATURE_SH_STANDALONE
274 # undef IF_FEATURE_SH_STANDALONE
275 # undef IF_NOT_FEATURE_SH_STANDALONE
276 # define ENABLE_FEATURE_SH_STANDALONE 0
277 # define IF_FEATURE_SH_STANDALONE(...)
278 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
281 #if !ENABLE_HUSH_INTERACTIVE
282 # undef ENABLE_FEATURE_EDITING
283 # define ENABLE_FEATURE_EDITING 0
284 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
285 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
288 /* Do we support ANY keywords? */
289 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
290 # define HAS_KEYWORDS 1
291 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
292 # define IF_HAS_NO_KEYWORDS(...)
294 # define HAS_KEYWORDS 0
295 # define IF_HAS_KEYWORDS(...)
296 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
299 /* If you comment out one of these below, it will be #defined later
300 * to perform debug printfs to stderr: */
301 #define debug_printf(...) do {} while (0)
302 /* Finer-grained debug switches */
303 #define debug_printf_parse(...) do {} while (0)
304 #define debug_print_tree(a, b) do {} while (0)
305 #define debug_printf_exec(...) do {} while (0)
306 #define debug_printf_env(...) do {} while (0)
307 #define debug_printf_jobs(...) do {} while (0)
308 #define debug_printf_expand(...) do {} while (0)
309 #define debug_printf_varexp(...) do {} while (0)
310 #define debug_printf_glob(...) do {} while (0)
311 #define debug_printf_list(...) do {} while (0)
312 #define debug_printf_subst(...) do {} while (0)
313 #define debug_printf_clean(...) do {} while (0)
315 #define ERR_PTR ((void*)(long)1)
317 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
319 #define _SPECIAL_VARS_STR "_*@$!?#"
320 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
321 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
322 #if ENABLE_HUSH_BASH_COMPAT
323 /* Support / and // replace ops */
324 /* Note that // is stored as \ in "encoded" string representation */
325 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
326 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
327 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
329 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
330 # define VAR_SUBST_OPS "%#:-=+?"
331 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
334 #define SPECIAL_VAR_SYMBOL 3
338 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
340 /* This supports saving pointers malloced in vfork child,
341 * to be freed in the parent.
344 typedef struct nommu_save_t {
346 struct variable *old_vars;
348 char **argv_from_re_execing;
361 #if ENABLE_HUSH_LOOPS
368 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
373 /* three pseudo-keywords support contrived "case" syntax: */
374 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
375 RES_MATCH , /* "word)" */
376 RES_CASE_BODY, /* "this command is inside CASE" */
384 EXP_FLAG_GLOB = 0x200,
385 EXP_FLAG_ESC_GLOB_CHARS = 0x100,
386 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
389 typedef struct o_string {
391 int length; /* position where data is appended */
393 /* Protect newly added chars against globbing
394 * (by prepending \ to *, ?, [, \) */
396 /* At least some part of the string was inside '' or "",
397 * possibly empty one: word"", wo''rd etc. */
398 smallint has_quoted_part;
399 smallint has_empty_slot;
400 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
403 MAYBE_ASSIGNMENT = 0,
404 DEFINITELY_ASSIGNMENT = 1,
406 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
408 /* Used for initialization: o_string foo = NULL_O_STRING; */
409 #define NULL_O_STRING { NULL }
411 /* I can almost use ordinary FILE*. Is open_memstream() universally
412 * available? Where is it documented? */
413 typedef struct in_str {
415 /* eof_flag=1: last char in ->p is really an EOF */
416 char eof_flag; /* meaningless if ->p == NULL */
418 #if ENABLE_HUSH_INTERACTIVE
420 smallint promptmode; /* 0: PS1, 1: PS2 */
423 int (*get) (struct in_str *) FAST_FUNC;
424 int (*peek) (struct in_str *) FAST_FUNC;
426 #define i_getch(input) ((input)->get(input))
427 #define i_peek(input) ((input)->peek(input))
429 /* The descrip member of this structure is only used to make
430 * debugging output pretty */
431 static const struct {
433 signed char default_fd;
436 { O_RDONLY, 0, "<" },
437 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
438 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
439 { O_CREAT|O_RDWR, 1, "<>" },
440 { O_RDONLY, 0, "<<" },
441 /* Should not be needed. Bogus default_fd helps in debugging */
442 /* { O_RDONLY, 77, "<<" }, */
445 struct redir_struct {
446 struct redir_struct *next;
447 char *rd_filename; /* filename */
448 int rd_fd; /* fd to redirect */
449 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
451 smallint rd_type; /* (enum redir_type) */
452 /* note: for heredocs, rd_filename contains heredoc delimiter,
453 * and subsequently heredoc itself; and rd_dup is a bitmask:
454 * bit 0: do we need to trim leading tabs?
455 * bit 1: is heredoc quoted (<<'delim' syntax) ?
458 typedef enum redir_type {
460 REDIRECT_OVERWRITE = 1,
463 REDIRECT_HEREDOC = 4,
464 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
467 REDIRFD_SYNTAX_ERR = -2,
468 REDIRFD_TO_FILE = -1,
469 /* otherwise, rd_fd is redirected to rd_dup */
471 HEREDOC_SKIPTABS = 1,
477 pid_t pid; /* 0 if exited */
478 int assignment_cnt; /* how many argv[i] are assignments? */
479 smallint is_stopped; /* is the command currently running? */
480 smallint cmd_type; /* CMD_xxx */
482 #define CMD_SUBSHELL 1
483 #if ENABLE_HUSH_BASH_COMPAT
484 /* used for "[[ EXPR ]]" */
485 # define CMD_SINGLEWORD_NOGLOB 2
487 #if ENABLE_HUSH_FUNCTIONS
488 # define CMD_FUNCDEF 3
491 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
494 char *group_as_string;
496 #if ENABLE_HUSH_FUNCTIONS
497 struct function *child_func;
498 /* This field is used to prevent a bug here:
499 * while...do f1() {a;}; f1; f1() {b;}; f1; done
500 * When we execute "f1() {a;}" cmd, we create new function and clear
501 * cmd->group, cmd->group_as_string, cmd->argv[0].
502 * When we execute "f1() {b;}", we notice that f1 exists,
503 * and that its "parent cmd" struct is still "alive",
504 * we put those fields back into cmd->xxx
505 * (struct function has ->parent_cmd ptr to facilitate that).
506 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
507 * Without this trick, loop would execute a;b;b;b;...
508 * instead of correct sequence a;b;a;b;...
509 * When command is freed, it severs the link
510 * (sets ->child_func->parent_cmd to NULL).
513 char **argv; /* command name and arguments */
514 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
515 * and on execution these are substituted with their values.
516 * Substitution can make _several_ words out of one argv[n]!
517 * Example: argv[0]=='.^C*^C.' here: echo .$*.
518 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
520 struct redir_struct *redirects; /* I/O redirections */
522 /* Is there anything in this command at all? */
523 #define IS_NULL_CMD(cmd) \
524 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
529 int num_cmds; /* total number of commands in pipe */
530 int alive_cmds; /* number of commands running (not exited) */
531 int stopped_cmds; /* number of commands alive, but stopped */
533 int jobid; /* job number */
534 pid_t pgrp; /* process group ID for the job */
535 char *cmdtext; /* name of job */
537 struct command *cmds; /* array of commands in pipe */
538 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
539 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
540 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
542 typedef enum pipe_style {
548 /* Is there anything in this pipe at all? */
549 #define IS_NULL_PIPE(pi) \
550 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
552 /* This holds pointers to the various results of parsing */
553 struct parse_context {
554 /* linked list of pipes */
555 struct pipe *list_head;
556 /* last pipe (being constructed right now) */
558 /* last command in pipe (being constructed right now) */
559 struct command *command;
560 /* last redirect in command->redirects list */
561 struct redir_struct *pending_redirect;
567 smallint ctx_inverted; /* "! cmd | cmd" */
569 smallint ctx_dsemicolon; /* ";;" seen */
571 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
573 /* group we are enclosed in:
574 * example: "if pipe1; pipe2; then pipe3; fi"
575 * when we see "if" or "then", we malloc and copy current context,
576 * and make ->stack point to it. then we parse pipeN.
577 * when closing "then" / fi" / whatever is found,
578 * we move list_head into ->stack->command->group,
579 * copy ->stack into current context, and delete ->stack.
580 * (parsing of { list } and ( list ) doesn't use this method)
582 struct parse_context *stack;
586 /* On program start, environ points to initial environment.
587 * putenv adds new pointers into it, unsetenv removes them.
588 * Neither of these (de)allocates the strings.
589 * setenv allocates new strings in malloc space and does putenv,
590 * and thus setenv is unusable (leaky) for shell's purposes */
591 #define setenv(...) setenv_is_leaky_dont_use()
593 struct variable *next;
594 char *varstr; /* points to "name=" portion */
595 #if ENABLE_HUSH_LOCAL
596 unsigned func_nest_level;
598 int max_len; /* if > 0, name is part of initial env; else name is malloced */
599 smallint flg_export; /* putenv should be done on this var */
600 smallint flg_read_only;
608 #if ENABLE_HUSH_FUNCTIONS
610 struct function *next;
612 struct command *parent_cmd;
615 char *body_as_string;
621 /* "Globals" within this file */
622 /* Sorted roughly by size (smaller offsets == smaller code) */
624 /* interactive_fd != 0 means we are an interactive shell.
625 * If we are, then saved_tty_pgrp can also be != 0, meaning
626 * that controlling tty is available. With saved_tty_pgrp == 0,
627 * job control still works, but terminal signals
628 * (^C, ^Z, ^Y, ^\) won't work at all, and background
629 * process groups can only be created with "cmd &".
630 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
631 * to give tty to the foreground process group,
632 * and will take it back when the group is stopped (^Z)
635 #if ENABLE_HUSH_INTERACTIVE
636 /* 'interactive_fd' is a fd# open to ctty, if we have one
637 * _AND_ if we decided to act interactively */
641 # define G_interactive_fd (G.interactive_fd)
643 # define G_interactive_fd 0
645 #if ENABLE_FEATURE_EDITING
646 line_input_t *line_input_state;
651 #if ENABLE_HUSH_RANDOM_SUPPORT
657 pid_t saved_tty_pgrp;
658 struct pipe *job_list;
659 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
661 # define G_saved_tty_pgrp 0
663 smallint flag_SIGINT;
664 #if ENABLE_HUSH_LOOPS
665 smallint flag_break_continue;
667 #if ENABLE_HUSH_FUNCTIONS
668 /* 0: outside of a function (or sourced file)
669 * -1: inside of a function, ok to use return builtin
670 * 1: return is invoked, skip all till end of func
672 smallint flag_return_in_progress;
675 #if ENABLE_HUSH_MODE_X
677 # define G_x_mode (G.x_mode)
681 smallint exiting; /* used to prevent EXIT trap recursion */
682 /* These four support $?, $#, and $1 */
683 smalluint last_exitcode;
684 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
685 smalluint global_args_malloced;
686 smalluint inherited_set_is_saved;
687 /* how many non-NULL argv's we have. NB: $# + 1 */
691 char *argv0_for_re_execing;
693 #if ENABLE_HUSH_LOOPS
694 unsigned depth_break_continue;
695 unsigned depth_of_loop;
699 struct variable *top_var; /* = &G.shell_ver (set in main()) */
700 struct variable shell_ver;
701 char **expanded_assignments;
702 #if ENABLE_HUSH_FUNCTIONS
703 struct function *top_func;
704 # if ENABLE_HUSH_LOCAL
705 struct variable **shadowed_vars_pp;
706 unsigned func_nest_level;
709 /* Signal and trap handling */
711 unsigned count_SIGCHLD;
712 unsigned handled_SIGCHLD;
713 smallint we_have_children;
715 /* which signals have non-DFL handler (even with no traps set)? */
716 unsigned non_DFL_mask;
717 char **traps; /* char *traps[NSIG] */
718 sigset_t blocked_set;
719 sigset_t inherited_set;
721 unsigned long memleak_value;
724 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
726 #define G (*ptr_to_globals)
727 /* Not #defining name to G.name - this quickly gets unwieldy
728 * (too many defines). Also, I actually prefer to see when a variable
729 * is global, thus "G." prefix is a useful hint */
730 #define INIT_G() do { \
731 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
735 /* Function prototypes for builtins */
736 static int builtin_cd(char **argv) FAST_FUNC;
737 static int builtin_echo(char **argv) FAST_FUNC;
738 static int builtin_eval(char **argv) FAST_FUNC;
739 static int builtin_exec(char **argv) FAST_FUNC;
740 static int builtin_exit(char **argv) FAST_FUNC;
741 static int builtin_export(char **argv) FAST_FUNC;
743 static int builtin_fg_bg(char **argv) FAST_FUNC;
744 static int builtin_jobs(char **argv) FAST_FUNC;
747 static int builtin_help(char **argv) FAST_FUNC;
749 #if ENABLE_HUSH_LOCAL
750 static int builtin_local(char **argv) FAST_FUNC;
753 static int builtin_memleak(char **argv) FAST_FUNC;
756 static int builtin_printf(char **argv) FAST_FUNC;
758 static int builtin_pwd(char **argv) FAST_FUNC;
759 static int builtin_read(char **argv) FAST_FUNC;
760 static int builtin_set(char **argv) FAST_FUNC;
761 static int builtin_shift(char **argv) FAST_FUNC;
762 static int builtin_source(char **argv) FAST_FUNC;
763 static int builtin_test(char **argv) FAST_FUNC;
764 static int builtin_trap(char **argv) FAST_FUNC;
765 static int builtin_type(char **argv) FAST_FUNC;
766 static int builtin_true(char **argv) FAST_FUNC;
767 static int builtin_umask(char **argv) FAST_FUNC;
768 static int builtin_unset(char **argv) FAST_FUNC;
769 static int builtin_wait(char **argv) FAST_FUNC;
770 #if ENABLE_HUSH_LOOPS
771 static int builtin_break(char **argv) FAST_FUNC;
772 static int builtin_continue(char **argv) FAST_FUNC;
774 #if ENABLE_HUSH_FUNCTIONS
775 static int builtin_return(char **argv) FAST_FUNC;
778 /* Table of built-in functions. They can be forked or not, depending on
779 * context: within pipes, they fork. As simple commands, they do not.
780 * When used in non-forking context, they can change global variables
781 * in the parent shell process. If forked, of course they cannot.
782 * For example, 'unset foo | whatever' will parse and run, but foo will
783 * still be set at the end. */
784 struct built_in_command {
786 int (*b_function)(char **argv) FAST_FUNC;
789 # define BLTIN(cmd, func, help) { cmd, func, help }
791 # define BLTIN(cmd, func, help) { cmd, func }
795 static const struct built_in_command bltins1[] = {
796 BLTIN("." , builtin_source , "Run commands in a file"),
797 BLTIN(":" , builtin_true , NULL),
799 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
801 #if ENABLE_HUSH_LOOPS
802 BLTIN("break" , builtin_break , "Exit from a loop"),
804 BLTIN("cd" , builtin_cd , "Change directory"),
805 #if ENABLE_HUSH_LOOPS
806 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
808 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
809 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
810 BLTIN("exit" , builtin_exit , "Exit"),
811 BLTIN("export" , builtin_export , "Set environment variables"),
813 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
816 BLTIN("help" , builtin_help , NULL),
819 BLTIN("jobs" , builtin_jobs , "List jobs"),
821 #if ENABLE_HUSH_LOCAL
822 BLTIN("local" , builtin_local , "Set local variables"),
825 BLTIN("memleak" , builtin_memleak , NULL),
827 BLTIN("read" , builtin_read , "Input into variable"),
828 #if ENABLE_HUSH_FUNCTIONS
829 BLTIN("return" , builtin_return , "Return from a function"),
831 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
832 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
833 #if ENABLE_HUSH_BASH_COMPAT
834 BLTIN("source" , builtin_source , "Run commands in a file"),
836 BLTIN("trap" , builtin_trap , "Trap signals"),
837 BLTIN("type" , builtin_type , "Show command type"),
838 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
839 BLTIN("umask" , builtin_umask , "Set file creation mask"),
840 BLTIN("unset" , builtin_unset , "Unset variables"),
841 BLTIN("wait" , builtin_wait , "Wait for process"),
843 /* For now, echo and test are unconditionally enabled.
844 * Maybe make it configurable? */
845 static const struct built_in_command bltins2[] = {
846 BLTIN("[" , builtin_test , NULL),
847 BLTIN("echo" , builtin_echo , NULL),
849 BLTIN("printf" , builtin_printf , NULL),
851 BLTIN("pwd" , builtin_pwd , NULL),
852 BLTIN("test" , builtin_test , NULL),
859 /* prevent disasters with G.debug_indent < 0 */
860 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
861 # define debug_enter() (G.debug_indent++)
862 # define debug_leave() (G.debug_indent--)
864 # define indent() ((void)0)
865 # define debug_enter() ((void)0)
866 # define debug_leave() ((void)0)
870 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
873 #ifndef debug_printf_parse
874 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
877 #ifndef debug_printf_exec
878 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
881 #ifndef debug_printf_env
882 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
885 #ifndef debug_printf_jobs
886 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
887 # define DEBUG_JOBS 1
889 # define DEBUG_JOBS 0
892 #ifndef debug_printf_expand
893 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
894 # define DEBUG_EXPAND 1
896 # define DEBUG_EXPAND 0
899 #ifndef debug_printf_varexp
900 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
903 #ifndef debug_printf_glob
904 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
905 # define DEBUG_GLOB 1
907 # define DEBUG_GLOB 0
910 #ifndef debug_printf_list
911 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
914 #ifndef debug_printf_subst
915 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
918 #ifndef debug_printf_clean
919 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
920 # define DEBUG_CLEAN 1
922 # define DEBUG_CLEAN 0
926 static void debug_print_strings(const char *prefix, char **vv)
929 fprintf(stderr, "%s:\n", prefix);
931 fprintf(stderr, " '%s'\n", *vv++);
934 # define debug_print_strings(prefix, vv) ((void)0)
938 /* Leak hunting. Use hush_leaktool.sh for post-processing.
941 static void *xxmalloc(int lineno, size_t size)
943 void *ptr = xmalloc((size + 0xff) & ~0xff);
944 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
947 static void *xxrealloc(int lineno, void *ptr, size_t size)
949 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
950 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
953 static char *xxstrdup(int lineno, const char *str)
955 char *ptr = xstrdup(str);
956 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
959 static void xxfree(void *ptr)
961 fdprintf(2, "free %p\n", ptr);
964 # define xmalloc(s) xxmalloc(__LINE__, s)
965 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
966 # define xstrdup(s) xxstrdup(__LINE__, s)
967 # define free(p) xxfree(p)
971 /* Syntax and runtime errors. They always abort scripts.
972 * In interactive use they usually discard unparsed and/or unexecuted commands
973 * and return to the prompt.
974 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
977 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
978 # define syntax_error(lineno, msg) syntax_error(msg)
979 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
980 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
981 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
982 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
985 static void die_if_script(unsigned lineno, const char *fmt, ...)
990 bb_error_msg("hush.c:%u", lineno);
993 bb_verror_msg(fmt, p, NULL);
995 if (!G_interactive_fd)
999 static void syntax_error(unsigned lineno, const char *msg)
1002 die_if_script(lineno, "syntax error: %s", msg);
1004 die_if_script(lineno, "syntax error", NULL);
1007 static void syntax_error_at(unsigned lineno, const char *msg)
1009 die_if_script(lineno, "syntax error at '%s'", msg);
1012 static void syntax_error_unterm_str(unsigned lineno, const char *s)
1014 die_if_script(lineno, "syntax error: unterminated %s", s);
1017 /* It so happens that all such cases are totally fatal
1018 * even if shell is interactive: EOF while looking for closing
1019 * delimiter. There is nowhere to read stuff from after that,
1020 * it's EOF! The only choice is to terminate.
1022 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
1023 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1025 char msg[2] = { ch, '\0' };
1026 syntax_error_unterm_str(lineno, msg);
1030 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
1035 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1039 # undef die_if_script
1040 # undef syntax_error
1041 # undef syntax_error_at
1042 # undef syntax_error_unterm_ch
1043 # undef syntax_error_unterm_str
1044 # undef syntax_error_unexpected_ch
1046 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1047 # define syntax_error(msg) syntax_error(__LINE__, msg)
1048 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1049 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1050 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1051 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1055 #if ENABLE_HUSH_INTERACTIVE
1056 static void cmdedit_update_prompt(void);
1058 # define cmdedit_update_prompt() ((void)0)
1062 /* Utility functions
1064 /* Replace each \x with x in place, return ptr past NUL. */
1065 static char *unbackslash(char *src)
1067 char *dst = src = strchrnul(src, '\\');
1071 if ((*dst++ = *src++) == '\0')
1077 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1098 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1099 v[count1 + count2] = NULL;
1102 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1106 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1108 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1109 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1112 #define add_strings_to_strings(strings, add, need_to_dup) \
1113 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1116 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1117 static char **add_string_to_strings(char **strings, char *add)
1122 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1125 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1127 char **ptr = add_string_to_strings(strings, add);
1128 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1131 #define add_string_to_strings(strings, add) \
1132 xx_add_string_to_strings(__LINE__, strings, add)
1135 static void free_strings(char **strings)
1150 /* Helpers for setting new $n and restoring them back
1152 typedef struct save_arg_t {
1156 smallint sv_g_malloced;
1159 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1163 sv->sv_argv0 = argv[0];
1164 sv->sv_g_argv = G.global_argv;
1165 sv->sv_g_argc = G.global_argc;
1166 sv->sv_g_malloced = G.global_args_malloced;
1168 argv[0] = G.global_argv[0]; /* retain $0 */
1169 G.global_argv = argv;
1170 G.global_args_malloced = 0;
1178 static void restore_G_args(save_arg_t *sv, char **argv)
1182 if (G.global_args_malloced) {
1183 /* someone ran "set -- arg1 arg2 ...", undo */
1185 while (*++pp) /* note: does not free $0 */
1187 free(G.global_argv);
1189 argv[0] = sv->sv_argv0;
1190 G.global_argv = sv->sv_g_argv;
1191 G.global_argc = sv->sv_g_argc;
1192 G.global_args_malloced = sv->sv_g_malloced;
1196 /* Basic theory of signal handling in shell
1197 * ========================================
1198 * This does not describe what hush does, rather, it is current understanding
1199 * what it _should_ do. If it doesn't, it's a bug.
1200 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1202 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1203 * is finished or backgrounded. It is the same in interactive and
1204 * non-interactive shells, and is the same regardless of whether
1205 * a user trap handler is installed or a shell special one is in effect.
1206 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1207 * backgrounds (i.e. stops) or kills all members of currently running
1210 * Wait builtin in interruptible by signals for which user trap is set
1211 * or by SIGINT in interactive shell.
1213 * Trap handlers will execute even within trap handlers. (right?)
1215 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1216 * except for handlers set to '' (empty string).
1218 * If job control is off, backgrounded commands ("cmd &")
1219 * have SIGINT, SIGQUIT set to SIG_IGN.
1221 * Commands which are run in command substitution ("`cmd`")
1222 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1224 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1225 * by the shell from its parent.
1227 * Signals which differ from SIG_DFL action
1228 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1231 * SIGTERM (interactive): ignore
1232 * SIGHUP (interactive):
1233 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1234 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1235 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1236 * that all pipe members are stopped. Try this in bash:
1237 * while :; do :; done - ^Z does not background it
1238 * (while :; do :; done) - ^Z backgrounds it
1239 * SIGINT (interactive): wait for last pipe, ignore the rest
1240 * of the command line, show prompt. NB: ^C does not send SIGINT
1241 * to interactive shell while shell is waiting for a pipe,
1242 * since shell is bg'ed (is not in foreground process group).
1243 * Example 1: this waits 5 sec, but does not execute ls:
1244 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1245 * Example 2: this does not wait and does not execute ls:
1246 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1247 * Example 3: this does not wait 5 sec, but executes ls:
1248 * "sleep 5; ls -l" + press ^C
1250 * (What happens to signals which are IGN on shell start?)
1251 * (What happens with signal mask on shell start?)
1253 * Implementation in hush
1254 * ======================
1255 * We use in-kernel pending signal mask to determine which signals were sent.
1256 * We block all signals which we don't want to take action immediately,
1257 * i.e. we block all signals which need to have special handling as described
1258 * above, and all signals which have traps set.
1259 * After each pipe execution, we extract any pending signals via sigtimedwait()
1262 * unsigned non_DFL_mask: a mask of such "special" signals
1263 * sigset_t blocked_set: current blocked signal set
1266 * clear bit in blocked_set unless it is also in non_DFL_mask
1267 * "trap 'cmd' SIGxxx":
1268 * set bit in blocked_set (even if 'cmd' is '')
1269 * after [v]fork, if we plan to be a shell:
1270 * unblock signals with special interactive handling
1271 * (child shell is not interactive),
1272 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1273 * after [v]fork, if we plan to exec:
1274 * POSIX says fork clears pending signal mask in child - no need to clear it.
1275 * Restore blocked signal set to one inherited by shell just prior to exec.
1277 * Note: as a result, we do not use signal handlers much. The only uses
1278 * are to count SIGCHLDs
1279 * and to restore tty pgrp on signal-induced exit.
1282 * Standard says "When a subshell is entered, traps that are not being ignored
1283 * are set to the default actions". bash interprets it so that traps which
1284 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1287 SPECIAL_INTERACTIVE_SIGS = 0
1292 SPECIAL_JOB_SIGS = 0
1300 #if ENABLE_HUSH_FAST
1301 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1304 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1310 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1311 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1312 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1313 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1315 /* Restores tty foreground process group, and exits.
1316 * May be called as signal handler for fatal signal
1317 * (will resend signal to itself, producing correct exit state)
1318 * or called directly with -EXITCODE.
1319 * We also call it if xfunc is exiting. */
1320 static void sigexit(int sig) NORETURN;
1321 static void sigexit(int sig)
1323 /* Disable all signals: job control, SIGPIPE, etc. */
1324 sigprocmask_allsigs(SIG_BLOCK);
1326 /* Careful: we can end up here after [v]fork. Do not restore
1327 * tty pgrp then, only top-level shell process does that */
1328 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1329 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1331 /* Not a signal, just exit */
1335 kill_myself_with_sig(sig); /* does not return */
1339 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1340 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1344 /* Restores tty foreground process group, and exits. */
1345 static void hush_exit(int exitcode) NORETURN;
1346 static void hush_exit(int exitcode)
1348 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1349 /* Prevent recursion:
1350 * trap "echo Hi; exit" EXIT; exit
1353 /* argv[0] is unused */
1354 argv[1] = G.traps[0];
1359 /* free(argv[1]); - why bother */
1364 sigexit(- (exitcode & 0xff));
1370 static int check_and_run_traps(int sig)
1372 static const struct timespec zero_timespec;
1373 smalluint save_rcode;
1379 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1384 if (G.traps && G.traps[sig]) {
1385 if (G.traps[sig][0]) {
1386 /* We have user-defined handler */
1388 /* argv[0] is unused */
1389 argv[1] = G.traps[sig];
1391 save_rcode = G.last_exitcode;
1393 G.last_exitcode = save_rcode;
1394 } /* else: "" trap, ignoring signal */
1397 /* not a trap: special action */
1399 #if ENABLE_HUSH_FAST
1402 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1406 /* Builtin was ^C'ed, make it look prettier: */
1413 /* bash is observed to signal whole process groups,
1414 * not individual processes */
1415 for (job = G.job_list; job; job = job->next) {
1418 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1419 if (kill(- job->pgrp, SIGHUP) == 0)
1420 kill(- job->pgrp, SIGCONT);
1425 default: /* ignored: */
1426 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1434 static const char *get_cwd(int force)
1436 if (force || G.cwd == NULL) {
1437 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1438 * we must not try to free(bb_msg_unknown) */
1439 if (G.cwd == bb_msg_unknown)
1441 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1443 G.cwd = bb_msg_unknown;
1450 * Shell and environment variable support
1452 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1454 struct variable **pp;
1455 struct variable *cur;
1458 while ((cur = *pp) != NULL) {
1459 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1466 static const char* FAST_FUNC get_local_var_value(const char *name)
1468 struct variable **vpp;
1469 unsigned len = strlen(name);
1471 if (G.expanded_assignments) {
1472 char **cpp = G.expanded_assignments;
1475 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1476 return cp + len + 1;
1481 vpp = get_ptr_to_local_var(name, len);
1483 return (*vpp)->varstr + len + 1;
1485 if (strcmp(name, "PPID") == 0)
1486 return utoa(G.root_ppid);
1487 // bash compat: UID? EUID?
1488 #if ENABLE_HUSH_RANDOM_SUPPORT
1489 if (strcmp(name, "RANDOM") == 0)
1490 return utoa(next_random(&G.random_gen));
1495 /* str holds "NAME=VAL" and is expected to be malloced.
1496 * We take ownership of it.
1498 * 0: do not change export flag
1499 * (if creating new variable, flag will be 0)
1500 * 1: set export flag and putenv the variable
1501 * -1: clear export flag and unsetenv the variable
1502 * flg_read_only is set only when we handle -R var=val
1504 #if !BB_MMU && ENABLE_HUSH_LOCAL
1505 /* all params are used */
1506 #elif BB_MMU && ENABLE_HUSH_LOCAL
1507 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1508 set_local_var(str, flg_export, local_lvl)
1509 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1510 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1511 set_local_var(str, flg_export)
1512 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1513 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1514 set_local_var(str, flg_export, flg_read_only)
1516 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1518 struct variable **var_pp;
1519 struct variable *cur;
1523 eq_sign = strchr(str, '=');
1524 if (!eq_sign) { /* not expected to ever happen? */
1529 name_len = eq_sign - str + 1; /* including '=' */
1530 var_pp = &G.top_var;
1531 while ((cur = *var_pp) != NULL) {
1532 if (strncmp(cur->varstr, str, name_len) != 0) {
1533 var_pp = &cur->next;
1536 /* We found an existing var with this name */
1537 if (cur->flg_read_only) {
1541 bb_error_msg("%s: readonly variable", str);
1545 if (flg_export == -1) { // "&& cur->flg_export" ?
1546 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1551 #if ENABLE_HUSH_LOCAL
1552 if (cur->func_nest_level < local_lvl) {
1553 /* New variable is declared as local,
1554 * and existing one is global, or local
1555 * from enclosing function.
1556 * Remove and save old one: */
1557 *var_pp = cur->next;
1558 cur->next = *G.shadowed_vars_pp;
1559 *G.shadowed_vars_pp = cur;
1560 /* bash 3.2.33(1) and exported vars:
1562 * # f() { local z=a; env | grep ^z; }
1568 if (cur->flg_export)
1573 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1578 if (cur->max_len != 0) {
1579 if (cur->max_len >= strlen(str)) {
1580 /* This one is from startup env, reuse space */
1581 strcpy(cur->varstr, str);
1585 /* max_len == 0 signifies "malloced" var, which we can
1586 * (and has to) free */
1590 goto set_str_and_exp;
1593 /* Not found - create new variable struct */
1594 cur = xzalloc(sizeof(*cur));
1595 #if ENABLE_HUSH_LOCAL
1596 cur->func_nest_level = local_lvl;
1598 cur->next = *var_pp;
1604 cur->flg_read_only = flg_read_only;
1607 if (flg_export == 1)
1608 cur->flg_export = 1;
1609 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1610 cmdedit_update_prompt();
1611 if (cur->flg_export) {
1612 if (flg_export == -1) {
1613 cur->flg_export = 0;
1614 /* unsetenv was already done */
1616 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1617 return putenv(cur->varstr);
1623 /* Used at startup and after each cd */
1624 static void set_pwd_var(int exp)
1626 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1627 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1630 static int unset_local_var_len(const char *name, int name_len)
1632 struct variable *cur;
1633 struct variable **var_pp;
1636 return EXIT_SUCCESS;
1637 var_pp = &G.top_var;
1638 while ((cur = *var_pp) != NULL) {
1639 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1640 if (cur->flg_read_only) {
1641 bb_error_msg("%s: readonly variable", name);
1642 return EXIT_FAILURE;
1644 *var_pp = cur->next;
1645 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1646 bb_unsetenv(cur->varstr);
1647 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1648 cmdedit_update_prompt();
1652 return EXIT_SUCCESS;
1654 var_pp = &cur->next;
1656 return EXIT_SUCCESS;
1659 static int unset_local_var(const char *name)
1661 return unset_local_var_len(name, strlen(name));
1664 static void unset_vars(char **strings)
1672 const char *eq = strchrnul(*v, '=');
1673 unset_local_var_len(*v, (int)(eq - *v));
1679 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1681 char *var = xasprintf("%s=%s", name, val);
1682 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1687 * Helpers for "var1=val1 var2=val2 cmd" feature
1689 static void add_vars(struct variable *var)
1691 struct variable *next;
1695 var->next = G.top_var;
1697 if (var->flg_export) {
1698 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1699 putenv(var->varstr);
1701 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1707 static struct variable *set_vars_and_save_old(char **strings)
1710 struct variable *old = NULL;
1716 struct variable *var_p;
1717 struct variable **var_pp;
1720 eq = strchr(*s, '=');
1722 var_pp = get_ptr_to_local_var(*s, eq - *s);
1724 /* Remove variable from global linked list */
1726 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1727 *var_pp = var_p->next;
1728 /* Add it to returned list */
1732 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1743 static int FAST_FUNC static_get(struct in_str *i)
1753 static int FAST_FUNC static_peek(struct in_str *i)
1758 #if ENABLE_HUSH_INTERACTIVE
1760 static void cmdedit_update_prompt(void)
1762 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1763 G.PS1 = get_local_var_value("PS1");
1766 G.PS2 = get_local_var_value("PS2");
1774 static const char *setup_prompt_string(int promptmode)
1776 const char *prompt_str;
1777 debug_printf("setup_prompt_string %d ", promptmode);
1778 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1779 /* Set up the prompt */
1780 if (promptmode == 0) { /* PS1 */
1782 /* bash uses $PWD value, even if it is set by user.
1783 * It uses current dir only if PWD is unset.
1784 * We always use current dir. */
1785 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1790 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1791 debug_printf("result '%s'\n", prompt_str);
1795 static void get_user_input(struct in_str *i)
1798 const char *prompt_str;
1800 prompt_str = setup_prompt_string(i->promptmode);
1801 # if ENABLE_FEATURE_EDITING
1802 /* Enable command line editing only while a command line
1803 * is actually being read */
1806 /* buglet: SIGINT will not make new prompt to appear _at once_,
1807 * only after <Enter>. (^C will work) */
1808 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1809 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1810 check_and_run_traps(0);
1811 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1812 i->eof_flag = (r < 0);
1813 if (i->eof_flag) { /* EOF/error detected */
1814 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1815 G.user_input_buf[1] = '\0';
1820 fputs(prompt_str, stdout);
1822 G.user_input_buf[0] = r = fgetc(i->file);
1823 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1824 //do we need check_and_run_traps(0)? (maybe only if stdin)
1825 } while (G.flag_SIGINT);
1826 i->eof_flag = (r == EOF);
1828 i->p = G.user_input_buf;
1831 #endif /* INTERACTIVE */
1833 /* This is the magic location that prints prompts
1834 * and gets data back from the user */
1835 static int FAST_FUNC file_get(struct in_str *i)
1839 /* If there is data waiting, eat it up */
1840 if (i->p && *i->p) {
1841 #if ENABLE_HUSH_INTERACTIVE
1845 if (i->eof_flag && !*i->p)
1847 /* note: ch is never NUL */
1849 /* need to double check i->file because we might be doing something
1850 * more complicated by now, like sourcing or substituting. */
1851 #if ENABLE_HUSH_INTERACTIVE
1852 if (G_interactive_fd && i->promptme && i->file == stdin) {
1855 } while (!*i->p); /* need non-empty line */
1856 i->promptmode = 1; /* PS2 */
1861 do ch = fgetc(i->file); while (ch == '\0');
1863 debug_printf("file_get: got '%c' %d\n", ch, ch);
1864 #if ENABLE_HUSH_INTERACTIVE
1871 /* All callers guarantee this routine will never
1872 * be used right after a newline, so prompting is not needed.
1874 static int FAST_FUNC file_peek(struct in_str *i)
1877 if (i->p && *i->p) {
1878 if (i->eof_flag && !i->p[1])
1881 /* note: ch is never NUL */
1883 do ch = fgetc(i->file); while (ch == '\0');
1884 i->eof_flag = (ch == EOF);
1885 i->peek_buf[0] = ch;
1886 i->peek_buf[1] = '\0';
1888 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1892 static void setup_file_in_str(struct in_str *i, FILE *f)
1894 i->peek = file_peek;
1896 #if ENABLE_HUSH_INTERACTIVE
1898 i->promptmode = 0; /* PS1 */
1904 static void setup_string_in_str(struct in_str *i, const char *s)
1906 i->peek = static_peek;
1907 i->get = static_get;
1908 #if ENABLE_HUSH_INTERACTIVE
1910 i->promptmode = 0; /* PS1 */
1920 #define B_CHUNK (32 * sizeof(char*))
1922 static void o_reset_to_empty_unquoted(o_string *o)
1925 o->has_quoted_part = 0;
1930 static void o_free(o_string *o)
1933 memset(o, 0, sizeof(*o));
1936 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1941 static void o_grow_by(o_string *o, int len)
1943 if (o->length + len > o->maxlen) {
1944 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1945 o->data = xrealloc(o->data, 1 + o->maxlen);
1949 static void o_addchr(o_string *o, int ch)
1951 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1953 o->data[o->length] = ch;
1955 o->data[o->length] = '\0';
1958 static void o_addblock(o_string *o, const char *str, int len)
1961 memcpy(&o->data[o->length], str, len);
1963 o->data[o->length] = '\0';
1966 static void o_addstr(o_string *o, const char *str)
1968 o_addblock(o, str, strlen(str));
1972 static void nommu_addchr(o_string *o, int ch)
1978 # define nommu_addchr(o, str) ((void)0)
1981 static void o_addstr_with_NUL(o_string *o, const char *str)
1983 o_addblock(o, str, strlen(str) + 1);
1986 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1991 if (*str++ == '\\') {
1992 /* \z -> \\\z; \<eol> -> \\<eol> */
1997 o_addchr(o, *str++);
2003 #undef HUSH_BRACE_EXP
2005 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
2006 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2007 * Apparently, on unquoted $v bash still does globbing
2008 * ("v='*.txt'; echo $v" prints all .txt files),
2009 * but NOT brace expansion! Thus, there should be TWO independent
2010 * quoting mechanisms on $v expansion side: one protects
2011 * $v from brace expansion, and other additionally protects "$v" against globbing.
2012 * We have only second one.
2015 #ifdef HUSH_BRACE_EXP
2016 # define MAYBE_BRACES "{}"
2018 # define MAYBE_BRACES ""
2021 /* My analysis of quoting semantics tells me that state information
2022 * is associated with a destination, not a source.
2024 static void o_addqchr(o_string *o, int ch)
2027 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2032 o->data[o->length] = '\\';
2035 o->data[o->length] = ch;
2037 o->data[o->length] = '\0';
2040 static void o_addQchr(o_string *o, int ch)
2043 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2044 && strchr("*?[\\" MAYBE_BRACES, ch)
2047 o->data[o->length] = '\\';
2051 o->data[o->length] = ch;
2053 o->data[o->length] = '\0';
2056 static void o_addqblock(o_string *o, const char *str, int len)
2061 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2062 if (ordinary_cnt > len) /* paranoia */
2064 o_addblock(o, str, ordinary_cnt);
2065 if (ordinary_cnt == len)
2067 str += ordinary_cnt;
2068 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2072 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2074 o->data[o->length] = '\\';
2078 o->data[o->length] = ch;
2080 o->data[o->length] = '\0';
2084 static void o_addQblock(o_string *o, const char *str, int len)
2086 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2087 o_addblock(o, str, len);
2090 o_addqblock(o, str, len);
2093 static void o_addQstr(o_string *o, const char *str)
2095 o_addQblock(o, str, strlen(str));
2098 /* A special kind of o_string for $VAR and `cmd` expansion.
2099 * It contains char* list[] at the beginning, which is grown in 16 element
2100 * increments. Actual string data starts at the next multiple of 16 * (char*).
2101 * list[i] contains an INDEX (int!) into this string data.
2102 * It means that if list[] needs to grow, data needs to be moved higher up
2103 * but list[i]'s need not be modified.
2104 * NB: remembering how many list[i]'s you have there is crucial.
2105 * o_finalize_list() operation post-processes this structure - calculates
2106 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2108 #if DEBUG_EXPAND || DEBUG_GLOB
2109 static void debug_print_list(const char *prefix, o_string *o, int n)
2111 char **list = (char**)o->data;
2112 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2116 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2117 prefix, list, n, string_start, o->length, o->maxlen,
2118 !!(o->o_expflags & EXP_FLAG_GLOB),
2120 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2123 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
2124 o->data + (int)list[i] + string_start,
2125 o->data + (int)list[i] + string_start);
2129 const char *p = o->data + (int)list[n - 1] + string_start;
2131 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2135 # define debug_print_list(prefix, o, n) ((void)0)
2138 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2139 * in list[n] so that it points past last stored byte so far.
2140 * It returns n+1. */
2141 static int o_save_ptr_helper(o_string *o, int n)
2143 char **list = (char**)o->data;
2147 if (!o->has_empty_slot) {
2148 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2149 string_len = o->length - string_start;
2150 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2151 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2152 /* list[n] points to string_start, make space for 16 more pointers */
2153 o->maxlen += 0x10 * sizeof(list[0]);
2154 o->data = xrealloc(o->data, o->maxlen + 1);
2155 list = (char**)o->data;
2156 memmove(list + n + 0x10, list + n, string_len);
2157 o->length += 0x10 * sizeof(list[0]);
2159 debug_printf_list("list[%d]=%d string_start=%d\n",
2160 n, string_len, string_start);
2163 /* We have empty slot at list[n], reuse without growth */
2164 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2165 string_len = o->length - string_start;
2166 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2167 n, string_len, string_start);
2168 o->has_empty_slot = 0;
2170 list[n] = (char*)(uintptr_t)string_len;
2174 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2175 static int o_get_last_ptr(o_string *o, int n)
2177 char **list = (char**)o->data;
2178 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2180 return ((int)(uintptr_t)list[n-1]) + string_start;
2183 #ifdef HUSH_BRACE_EXP
2184 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2185 * first, it processes even {a} (no commas), second,
2186 * I didn't manage to make it return strings when they don't match
2187 * existing files. Need to re-implement it.
2191 static int glob_needed(const char *s)
2200 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2206 /* Return pointer to next closing brace or to comma */
2207 static const char *next_brace_sub(const char *cp)
2211 while (*cp != '\0') {
2218 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2224 return *cp != '\0' ? cp : NULL;
2226 /* Recursive brace globber. Note: may garble pattern[]. */
2227 static int glob_brace(char *pattern, o_string *o, int n)
2229 char *new_pattern_buf;
2236 debug_printf_glob("glob_brace('%s')\n", pattern);
2242 if (*begin == '{') {
2243 /* Find the first sub-pattern and at the same time
2244 * find the rest after the closing brace */
2245 next = next_brace_sub(begin);
2247 /* An illegal expression */
2251 /* "{abc}" with no commas - illegal
2252 * brace expr, disregard and skip it */
2258 if (*begin == '\\' && begin[1] != '\0')
2262 debug_printf_glob("begin:%s\n", begin);
2263 debug_printf_glob("next:%s\n", next);
2265 /* Now find the end of the whole brace expression */
2267 while (*rest != '}') {
2268 rest = next_brace_sub(rest);
2270 /* An illegal expression */
2273 debug_printf_glob("rest:%s\n", rest);
2275 rest_len = strlen(++rest) + 1;
2277 /* We are sure the brace expression is well-formed */
2279 /* Allocate working buffer large enough for our work */
2280 new_pattern_buf = xmalloc(strlen(pattern));
2282 /* We have a brace expression. BEGIN points to the opening {,
2283 * NEXT points past the terminator of the first element, and REST
2284 * points past the final }. We will accumulate result names from
2285 * recursive runs for each brace alternative in the buffer using
2290 /* Construct the new glob expression */
2293 mempcpy(new_pattern_buf,
2294 /* We know the prefix for all sub-patterns */
2295 pattern, begin - pattern),
2299 /* Note: glob_brace() may garble new_pattern_buf[].
2300 * That's why we re-copy prefix every time (1st memcpy above).
2302 n = glob_brace(new_pattern_buf, o, n);
2304 /* We saw the last entry */
2308 next = next_brace_sub(next);
2310 free(new_pattern_buf);
2318 memset(&globdata, 0, sizeof(globdata));
2319 gr = glob(pattern, 0, NULL, &globdata);
2320 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2322 if (gr == GLOB_NOMATCH) {
2323 globfree(&globdata);
2324 /* NB: garbles parameter */
2325 unbackslash(pattern);
2326 o_addstr_with_NUL(o, pattern);
2327 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2328 return o_save_ptr_helper(o, n);
2330 if (gr == GLOB_NOSPACE)
2331 bb_error_msg_and_die(bb_msg_memory_exhausted);
2332 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2333 * but we didn't specify it. Paranoia again. */
2334 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2336 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2337 char **argv = globdata.gl_pathv;
2339 o_addstr_with_NUL(o, *argv);
2340 n = o_save_ptr_helper(o, n);
2346 globfree(&globdata);
2350 /* Performs globbing on last list[],
2351 * saving each result as a new list[].
2353 static int perform_glob(o_string *o, int n)
2355 char *pattern, *copy;
2357 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2359 return o_save_ptr_helper(o, n);
2360 pattern = o->data + o_get_last_ptr(o, n);
2361 debug_printf_glob("glob pattern '%s'\n", pattern);
2362 if (!glob_needed(pattern)) {
2363 /* unbackslash last string in o in place, fix length */
2364 o->length = unbackslash(pattern) - o->data;
2365 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2366 return o_save_ptr_helper(o, n);
2369 copy = xstrdup(pattern);
2370 /* "forget" pattern in o */
2371 o->length = pattern - o->data;
2372 n = glob_brace(copy, o, n);
2375 debug_print_list("perform_glob returning", o, n);
2379 #else /* !HUSH_BRACE_EXP */
2382 static int glob_needed(const char *s)
2391 if (*s == '*' || *s == '[' || *s == '?')
2397 /* Performs globbing on last list[],
2398 * saving each result as a new list[].
2400 static int perform_glob(o_string *o, int n)
2406 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2408 return o_save_ptr_helper(o, n);
2409 pattern = o->data + o_get_last_ptr(o, n);
2410 debug_printf_glob("glob pattern '%s'\n", pattern);
2411 if (!glob_needed(pattern)) {
2413 /* unbackslash last string in o in place, fix length */
2414 o->length = unbackslash(pattern) - o->data;
2415 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2416 return o_save_ptr_helper(o, n);
2419 memset(&globdata, 0, sizeof(globdata));
2420 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2421 * If we glob "*.\*" and don't find anything, we need
2422 * to fall back to using literal "*.*", but GLOB_NOCHECK
2423 * will return "*.\*"!
2425 gr = glob(pattern, 0, NULL, &globdata);
2426 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2428 if (gr == GLOB_NOMATCH) {
2429 globfree(&globdata);
2432 if (gr == GLOB_NOSPACE)
2433 bb_error_msg_and_die(bb_msg_memory_exhausted);
2434 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2435 * but we didn't specify it. Paranoia again. */
2436 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2438 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2439 char **argv = globdata.gl_pathv;
2440 /* "forget" pattern in o */
2441 o->length = pattern - o->data;
2443 o_addstr_with_NUL(o, *argv);
2444 n = o_save_ptr_helper(o, n);
2450 globfree(&globdata);
2452 debug_print_list("perform_glob returning", o, n);
2456 #endif /* !HUSH_BRACE_EXP */
2458 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2459 * Otherwise, just finish current list[] and start new */
2460 static int o_save_ptr(o_string *o, int n)
2462 if (o->o_expflags & EXP_FLAG_GLOB) {
2463 /* If o->has_empty_slot, list[n] was already globbed
2464 * (if it was requested back then when it was filled)
2465 * so don't do that again! */
2466 if (!o->has_empty_slot)
2467 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2469 return o_save_ptr_helper(o, n);
2472 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2473 static char **o_finalize_list(o_string *o, int n)
2478 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2480 debug_print_list("finalized", o, n);
2481 debug_printf_expand("finalized n:%d\n", n);
2482 list = (char**)o->data;
2483 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2487 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2492 static void free_pipe_list(struct pipe *pi);
2494 /* Returns pi->next - next pipe in the list */
2495 static struct pipe *free_pipe(struct pipe *pi)
2500 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2501 for (i = 0; i < pi->num_cmds; i++) {
2502 struct command *command;
2503 struct redir_struct *r, *rnext;
2505 command = &pi->cmds[i];
2506 debug_printf_clean(" command %d:\n", i);
2507 if (command->argv) {
2511 for (a = 0, p = command->argv; *p; a++, p++) {
2512 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2515 free_strings(command->argv);
2516 //command->argv = NULL;
2518 /* not "else if": on syntax error, we may have both! */
2519 if (command->group) {
2520 debug_printf_clean(" begin group (cmd_type:%d)\n",
2522 free_pipe_list(command->group);
2523 debug_printf_clean(" end group\n");
2524 //command->group = NULL;
2526 /* else is crucial here.
2527 * If group != NULL, child_func is meaningless */
2528 #if ENABLE_HUSH_FUNCTIONS
2529 else if (command->child_func) {
2530 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2531 command->child_func->parent_cmd = NULL;
2535 free(command->group_as_string);
2536 //command->group_as_string = NULL;
2538 for (r = command->redirects; r; r = rnext) {
2539 debug_printf_clean(" redirect %d%s",
2540 r->rd_fd, redir_table[r->rd_type].descrip);
2541 /* guard against the case >$FOO, where foo is unset or blank */
2542 if (r->rd_filename) {
2543 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2544 free(r->rd_filename);
2545 //r->rd_filename = NULL;
2547 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2551 //command->redirects = NULL;
2553 free(pi->cmds); /* children are an array, they get freed all at once */
2557 //pi->cmdtext = NULL;
2565 static void free_pipe_list(struct pipe *pi)
2569 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2571 debug_printf_clean("pipe followup code %d\n", pi->followup);
2577 /*** Parsing routines ***/
2579 static struct pipe *new_pipe(void)
2582 pi = xzalloc(sizeof(struct pipe));
2583 /*pi->followup = 0; - deliberately invalid value */
2584 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2588 /* Command (member of a pipe) is complete, or we start a new pipe
2589 * if ctx->command is NULL.
2590 * No errors possible here.
2592 static int done_command(struct parse_context *ctx)
2594 /* The command is really already in the pipe structure, so
2595 * advance the pipe counter and make a new, null command. */
2596 struct pipe *pi = ctx->pipe;
2597 struct command *command = ctx->command;
2600 if (IS_NULL_CMD(command)) {
2601 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2605 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2606 //debug_print_tree(ctx->list_head, 20);
2608 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2611 /* Only real trickiness here is that the uncommitted
2612 * command structure is not counted in pi->num_cmds. */
2613 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2614 ctx->command = command = &pi->cmds[pi->num_cmds];
2616 memset(command, 0, sizeof(*command));
2617 return pi->num_cmds; /* used only for 0/nonzero check */
2620 static void done_pipe(struct parse_context *ctx, pipe_style type)
2624 debug_printf_parse("done_pipe entered, followup %d\n", type);
2625 /* Close previous command */
2626 not_null = done_command(ctx);
2627 ctx->pipe->followup = type;
2629 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2630 ctx->ctx_inverted = 0;
2631 ctx->pipe->res_word = ctx->ctx_res_w;
2634 /* Without this check, even just <enter> on command line generates
2635 * tree of three NOPs (!). Which is harmless but annoying.
2636 * IOW: it is safe to do it unconditionally. */
2639 || ctx->ctx_res_w == RES_FI
2641 #if ENABLE_HUSH_LOOPS
2642 || ctx->ctx_res_w == RES_DONE
2643 || ctx->ctx_res_w == RES_FOR
2644 || ctx->ctx_res_w == RES_IN
2646 #if ENABLE_HUSH_CASE
2647 || ctx->ctx_res_w == RES_ESAC
2651 debug_printf_parse("done_pipe: adding new pipe: "
2652 "not_null:%d ctx->ctx_res_w:%d\n",
2653 not_null, ctx->ctx_res_w);
2655 ctx->pipe->next = new_p;
2657 /* RES_THEN, RES_DO etc are "sticky" -
2658 * they remain set for pipes inside if/while.
2659 * This is used to control execution.
2660 * RES_FOR and RES_IN are NOT sticky (needed to support
2661 * cases where variable or value happens to match a keyword):
2663 #if ENABLE_HUSH_LOOPS
2664 if (ctx->ctx_res_w == RES_FOR
2665 || ctx->ctx_res_w == RES_IN)
2666 ctx->ctx_res_w = RES_NONE;
2668 #if ENABLE_HUSH_CASE
2669 if (ctx->ctx_res_w == RES_MATCH)
2670 ctx->ctx_res_w = RES_CASE_BODY;
2671 if (ctx->ctx_res_w == RES_CASE)
2672 ctx->ctx_res_w = RES_CASE_IN;
2674 ctx->command = NULL; /* trick done_command below */
2675 /* Create the memory for command, roughly:
2676 * ctx->pipe->cmds = new struct command;
2677 * ctx->command = &ctx->pipe->cmds[0];
2680 //debug_print_tree(ctx->list_head, 10);
2682 debug_printf_parse("done_pipe return\n");
2685 static void initialize_context(struct parse_context *ctx)
2687 memset(ctx, 0, sizeof(*ctx));
2688 ctx->pipe = ctx->list_head = new_pipe();
2689 /* Create the memory for command, roughly:
2690 * ctx->pipe->cmds = new struct command;
2691 * ctx->command = &ctx->pipe->cmds[0];
2696 /* If a reserved word is found and processed, parse context is modified
2697 * and 1 is returned.
2700 struct reserved_combo {
2703 unsigned char assignment_flag;
2707 FLAG_END = (1 << RES_NONE ),
2709 FLAG_IF = (1 << RES_IF ),
2710 FLAG_THEN = (1 << RES_THEN ),
2711 FLAG_ELIF = (1 << RES_ELIF ),
2712 FLAG_ELSE = (1 << RES_ELSE ),
2713 FLAG_FI = (1 << RES_FI ),
2715 # if ENABLE_HUSH_LOOPS
2716 FLAG_FOR = (1 << RES_FOR ),
2717 FLAG_WHILE = (1 << RES_WHILE),
2718 FLAG_UNTIL = (1 << RES_UNTIL),
2719 FLAG_DO = (1 << RES_DO ),
2720 FLAG_DONE = (1 << RES_DONE ),
2721 FLAG_IN = (1 << RES_IN ),
2723 # if ENABLE_HUSH_CASE
2724 FLAG_MATCH = (1 << RES_MATCH),
2725 FLAG_ESAC = (1 << RES_ESAC ),
2727 FLAG_START = (1 << RES_XXXX ),
2730 static const struct reserved_combo* match_reserved_word(o_string *word)
2732 /* Mostly a list of accepted follow-up reserved words.
2733 * FLAG_END means we are done with the sequence, and are ready
2734 * to turn the compound list into a command.
2735 * FLAG_START means the word must start a new compound list.
2737 static const struct reserved_combo reserved_list[] = {
2739 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
2740 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
2741 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2742 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
2743 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
2744 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
2746 # if ENABLE_HUSH_LOOPS
2747 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
2748 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2749 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2750 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
2751 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
2752 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
2754 # if ENABLE_HUSH_CASE
2755 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
2756 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
2759 const struct reserved_combo *r;
2761 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2762 if (strcmp(word->data, r->literal) == 0)
2767 /* Return 0: not a keyword, 1: keyword
2769 static int reserved_word(o_string *word, struct parse_context *ctx)
2771 # if ENABLE_HUSH_CASE
2772 static const struct reserved_combo reserved_match = {
2773 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
2776 const struct reserved_combo *r;
2778 if (word->has_quoted_part)
2780 r = match_reserved_word(word);
2784 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2785 # if ENABLE_HUSH_CASE
2786 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
2787 /* "case word IN ..." - IN part starts first MATCH part */
2788 r = &reserved_match;
2791 if (r->flag == 0) { /* '!' */
2792 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
2793 syntax_error("! ! command");
2794 ctx->ctx_res_w = RES_SNTX;
2796 ctx->ctx_inverted = 1;
2799 if (r->flag & FLAG_START) {
2800 struct parse_context *old;
2802 old = xmalloc(sizeof(*old));
2803 debug_printf_parse("push stack %p\n", old);
2804 *old = *ctx; /* physical copy */
2805 initialize_context(ctx);
2807 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
2808 syntax_error_at(word->data);
2809 ctx->ctx_res_w = RES_SNTX;
2812 /* "{...} fi" is ok. "{...} if" is not
2814 * if { echo foo; } then { echo bar; } fi */
2815 if (ctx->command->group)
2816 done_pipe(ctx, PIPE_SEQ);
2819 ctx->ctx_res_w = r->res;
2820 ctx->old_flag = r->flag;
2821 word->o_assignment = r->assignment_flag;
2823 if (ctx->old_flag & FLAG_END) {
2824 struct parse_context *old;
2826 done_pipe(ctx, PIPE_SEQ);
2827 debug_printf_parse("pop stack %p\n", ctx->stack);
2829 old->command->group = ctx->list_head;
2830 old->command->cmd_type = CMD_NORMAL;
2832 o_addstr(&old->as_string, ctx->as_string.data);
2833 o_free_unsafe(&ctx->as_string);
2834 old->command->group_as_string = xstrdup(old->as_string.data);
2835 debug_printf_parse("pop, remembering as:'%s'\n",
2836 old->command->group_as_string);
2838 *ctx = *old; /* physical copy */
2843 #endif /* HAS_KEYWORDS */
2845 /* Word is complete, look at it and update parsing context.
2846 * Normal return is 0. Syntax errors return 1.
2847 * Note: on return, word is reset, but not o_free'd!
2849 static int done_word(o_string *word, struct parse_context *ctx)
2851 struct command *command = ctx->command;
2853 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
2854 if (word->length == 0 && !word->has_quoted_part) {
2855 debug_printf_parse("done_word return 0: true null, ignored\n");
2859 if (ctx->pending_redirect) {
2860 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
2861 * only if run as "bash", not "sh" */
2862 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
2864 * ...the word that follows the redirection operator
2865 * shall be subjected to tilde expansion, parameter expansion,
2866 * command substitution, arithmetic expansion, and quote
2867 * removal. Pathname expansion shall not be performed
2868 * on the word by a non-interactive shell; an interactive
2869 * shell may perform it, but shall do so only when
2870 * the expansion would result in one word."
2872 ctx->pending_redirect->rd_filename = xstrdup(word->data);
2873 /* Cater for >\file case:
2874 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
2875 * Same with heredocs:
2876 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
2878 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
2879 unbackslash(ctx->pending_redirect->rd_filename);
2880 /* Is it <<"HEREDOC"? */
2881 if (word->has_quoted_part) {
2882 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
2885 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
2886 ctx->pending_redirect = NULL;
2888 /* If this word wasn't an assignment, next ones definitely
2889 * can't be assignments. Even if they look like ones. */
2890 if (word->o_assignment != DEFINITELY_ASSIGNMENT
2891 && word->o_assignment != WORD_IS_KEYWORD
2893 word->o_assignment = NOT_ASSIGNMENT;
2895 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
2896 command->assignment_cnt++;
2897 word->o_assignment = MAYBE_ASSIGNMENT;
2901 # if ENABLE_HUSH_CASE
2902 if (ctx->ctx_dsemicolon
2903 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
2905 /* already done when ctx_dsemicolon was set to 1: */
2906 /* ctx->ctx_res_w = RES_MATCH; */
2907 ctx->ctx_dsemicolon = 0;
2910 if (!command->argv /* if it's the first word... */
2911 # if ENABLE_HUSH_LOOPS
2912 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
2913 && ctx->ctx_res_w != RES_IN
2915 # if ENABLE_HUSH_CASE
2916 && ctx->ctx_res_w != RES_CASE
2919 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
2920 if (reserved_word(word, ctx)) {
2921 o_reset_to_empty_unquoted(word);
2922 debug_printf_parse("done_word return %d\n",
2923 (ctx->ctx_res_w == RES_SNTX));
2924 return (ctx->ctx_res_w == RES_SNTX);
2926 # if ENABLE_HUSH_BASH_COMPAT
2927 if (strcmp(word->data, "[[") == 0) {
2928 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
2934 if (command->group) {
2935 /* "{ echo foo; } echo bar" - bad */
2936 syntax_error_at(word->data);
2937 debug_printf_parse("done_word return 1: syntax error, "
2938 "groups and arglists don't mix\n");
2941 if (word->has_quoted_part
2942 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
2943 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
2944 /* (otherwise it's known to be not empty and is already safe) */
2946 /* exclude "$@" - it can expand to no word despite "" */
2947 char *p = word->data;
2948 while (p[0] == SPECIAL_VAR_SYMBOL
2949 && (p[1] & 0x7f) == '@'
2950 && p[2] == SPECIAL_VAR_SYMBOL
2954 if (p == word->data || p[0] != '\0') {
2955 /* saw no "$@", or not only "$@" but some
2956 * real text is there too */
2957 /* insert "empty variable" reference, this makes
2958 * e.g. "", $empty"" etc to not disappear */
2959 o_addchr(word, SPECIAL_VAR_SYMBOL);
2960 o_addchr(word, SPECIAL_VAR_SYMBOL);
2963 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
2964 debug_print_strings("word appended to argv", command->argv);
2967 #if ENABLE_HUSH_LOOPS
2968 if (ctx->ctx_res_w == RES_FOR) {
2969 if (word->has_quoted_part
2970 || !is_well_formed_var_name(command->argv[0], '\0')
2972 /* bash says just "not a valid identifier" */
2973 syntax_error("not a valid identifier in for");
2976 /* Force FOR to have just one word (variable name) */
2977 /* NB: basically, this makes hush see "for v in ..."
2978 * syntax as if it is "for v; in ...". FOR and IN become
2979 * two pipe structs in parse tree. */
2980 done_pipe(ctx, PIPE_SEQ);
2983 #if ENABLE_HUSH_CASE
2984 /* Force CASE to have just one word */
2985 if (ctx->ctx_res_w == RES_CASE) {
2986 done_pipe(ctx, PIPE_SEQ);
2990 o_reset_to_empty_unquoted(word);
2992 debug_printf_parse("done_word return 0\n");
2997 /* Peek ahead in the input to find out if we have a "&n" construct,
2998 * as in "2>&1", that represents duplicating a file descriptor.
3000 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3001 * REDIRFD_SYNTAX_ERR if syntax error,
3002 * REDIRFD_TO_FILE if no & was seen,
3003 * or the number found.
3006 #define parse_redir_right_fd(as_string, input) \
3007 parse_redir_right_fd(input)
3009 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3015 return REDIRFD_TO_FILE;
3017 ch = i_getch(input); /* get the & */
3018 nommu_addchr(as_string, ch);
3021 ch = i_getch(input);
3022 nommu_addchr(as_string, ch);
3023 return REDIRFD_CLOSE;
3027 while (ch != EOF && isdigit(ch)) {
3028 d = d*10 + (ch-'0');
3030 ch = i_getch(input);
3031 nommu_addchr(as_string, ch);
3036 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3038 bb_error_msg("ambiguous redirect");
3039 return REDIRFD_SYNTAX_ERR;
3042 /* Return code is 0 normal, 1 if a syntax error is detected
3044 static int parse_redirect(struct parse_context *ctx,
3047 struct in_str *input)
3049 struct command *command = ctx->command;
3050 struct redir_struct *redir;
3051 struct redir_struct **redirp;
3054 dup_num = REDIRFD_TO_FILE;
3055 if (style != REDIRECT_HEREDOC) {
3056 /* Check for a '>&1' type redirect */
3057 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3058 if (dup_num == REDIRFD_SYNTAX_ERR)
3061 int ch = i_peek(input);
3062 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3063 if (dup_num) { /* <<-... */
3064 ch = i_getch(input);
3065 nommu_addchr(&ctx->as_string, ch);
3070 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3071 int ch = i_peek(input);
3073 /* >|FILE redirect ("clobbering" >).
3074 * Since we do not support "set -o noclobber" yet,
3075 * >| and > are the same for now. Just eat |.
3077 ch = i_getch(input);
3078 nommu_addchr(&ctx->as_string, ch);
3082 /* Create a new redir_struct and append it to the linked list */
3083 redirp = &command->redirects;
3084 while ((redir = *redirp) != NULL) {
3085 redirp = &(redir->next);
3087 *redirp = redir = xzalloc(sizeof(*redir));
3088 /* redir->next = NULL; */
3089 /* redir->rd_filename = NULL; */
3090 redir->rd_type = style;
3091 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3093 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3094 redir_table[style].descrip);
3096 redir->rd_dup = dup_num;
3097 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3098 /* Erik had a check here that the file descriptor in question
3099 * is legit; I postpone that to "run time"
3100 * A "-" representation of "close me" shows up as a -3 here */
3101 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3102 redir->rd_fd, redir->rd_dup);
3104 /* Set ctx->pending_redirect, so we know what to do at the
3105 * end of the next parsed word. */
3106 ctx->pending_redirect = redir;
3111 /* If a redirect is immediately preceded by a number, that number is
3112 * supposed to tell which file descriptor to redirect. This routine
3113 * looks for such preceding numbers. In an ideal world this routine
3114 * needs to handle all the following classes of redirects...
3115 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3116 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3117 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3118 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3120 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3122 * ... If n is quoted, the number shall not be recognized as part of
3123 * the redirection expression. For example:
3125 * writes the character 2 into file a"
3126 * We are getting it right by setting ->has_quoted_part on any \<char>
3128 * A -1 return means no valid number was found,
3129 * the caller should use the appropriate default for this redirection.
3131 static int redirect_opt_num(o_string *o)
3135 if (o->data == NULL)
3137 num = bb_strtou(o->data, NULL, 10);
3138 if (errno || num < 0)
3140 o_reset_to_empty_unquoted(o);
3145 #define fetch_till_str(as_string, input, word, skip_tabs) \
3146 fetch_till_str(input, word, skip_tabs)
3148 static char *fetch_till_str(o_string *as_string,
3149 struct in_str *input,
3153 o_string heredoc = NULL_O_STRING;
3155 int prev = 0; /* not \ */
3160 ch = i_getch(input);
3161 nommu_addchr(as_string, ch);
3163 /* TODO: or EOF? (heredoc delimiter may end with <eof>, not only <eol>) */
3164 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3166 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3167 heredoc.data[past_EOL] = '\0';
3168 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3169 return heredoc.data;
3172 o_addchr(&heredoc, '\n');
3173 prev = 0; /* not \ */
3174 past_EOL = heredoc.length;
3177 ch = i_getch(input);
3178 nommu_addchr(as_string, ch);
3179 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3180 } while (ch == '\n');
3183 o_free_unsafe(&heredoc);
3186 o_addchr(&heredoc, ch);
3187 if (prev == '\\' && ch == '\\')
3188 /* Correctly handle foo\\<eol> (not a line cont.) */
3189 prev = 0; /* not \ */
3192 nommu_addchr(as_string, ch);
3196 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3197 * and load them all. There should be exactly heredoc_cnt of them.
3199 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3201 struct pipe *pi = ctx->list_head;
3203 while (pi && heredoc_cnt) {
3205 struct command *cmd = pi->cmds;
3207 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3209 cmd->argv ? cmd->argv[0] : "NONE");
3210 for (i = 0; i < pi->num_cmds; i++) {
3211 struct redir_struct *redir = cmd->redirects;
3213 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3214 i, cmd->argv ? cmd->argv[0] : "NONE");
3216 if (redir->rd_type == REDIRECT_HEREDOC) {
3219 redir->rd_type = REDIRECT_HEREDOC2;
3220 /* redir->rd_dup is (ab)used to indicate <<- */
3221 p = fetch_till_str(&ctx->as_string, input,
3222 redir->rd_filename, redir->rd_dup);
3224 syntax_error("unexpected EOF in here document");
3227 free(redir->rd_filename);
3228 redir->rd_filename = p;
3231 redir = redir->next;
3238 /* Should be 0. If it isn't, it's a parse error */
3240 bb_error_msg_and_die("heredoc BUG 2");
3246 static int run_list(struct pipe *pi);
3248 #define parse_stream(pstring, input, end_trigger) \
3249 parse_stream(input, end_trigger)
3251 static struct pipe *parse_stream(char **pstring,
3252 struct in_str *input,
3256 #if !ENABLE_HUSH_FUNCTIONS
3257 #define parse_group(dest, ctx, input, ch) \
3258 parse_group(ctx, input, ch)
3260 static int parse_group(o_string *dest, struct parse_context *ctx,
3261 struct in_str *input, int ch)
3263 /* dest contains characters seen prior to ( or {.
3264 * Typically it's empty, but for function defs,
3265 * it contains function name (without '()'). */
3266 struct pipe *pipe_list;
3268 struct command *command = ctx->command;
3270 debug_printf_parse("parse_group entered\n");
3271 #if ENABLE_HUSH_FUNCTIONS
3272 if (ch == '(' && !dest->has_quoted_part) {
3274 if (done_word(dest, ctx))
3277 goto skip; /* (... */
3278 if (command->argv[1]) { /* word word ... (... */
3279 syntax_error_unexpected_ch('(');
3282 /* it is "word(..." or "word (..." */
3284 ch = i_getch(input);
3285 while (ch == ' ' || ch == '\t');
3287 syntax_error_unexpected_ch(ch);
3290 nommu_addchr(&ctx->as_string, ch);
3292 ch = i_getch(input);
3293 while (ch == ' ' || ch == '\t' || ch == '\n');
3295 syntax_error_unexpected_ch(ch);
3298 nommu_addchr(&ctx->as_string, ch);
3299 command->cmd_type = CMD_FUNCDEF;
3304 #if 0 /* Prevented by caller */
3305 if (command->argv /* word [word]{... */
3306 || dest->length /* word{... */
3307 || dest->has_quoted_part /* ""{... */
3310 debug_printf_parse("parse_group return 1: "
3311 "syntax error, groups and arglists don't mix\n");
3316 #if ENABLE_HUSH_FUNCTIONS
3322 command->cmd_type = CMD_SUBSHELL;
3324 /* bash does not allow "{echo...", requires whitespace */
3325 ch = i_getch(input);
3326 if (ch != ' ' && ch != '\t' && ch != '\n') {
3327 syntax_error_unexpected_ch(ch);
3330 nommu_addchr(&ctx->as_string, ch);
3335 # define as_string NULL
3337 char *as_string = NULL;
3339 pipe_list = parse_stream(&as_string, input, endch);
3342 o_addstr(&ctx->as_string, as_string);
3344 /* empty ()/{} or parse error? */
3345 if (!pipe_list || pipe_list == ERR_PTR) {
3346 /* parse_stream already emitted error msg */
3349 debug_printf_parse("parse_group return 1: "
3350 "parse_stream returned %p\n", pipe_list);
3353 command->group = pipe_list;
3355 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3356 command->group_as_string = as_string;
3357 debug_printf_parse("end of group, remembering as:'%s'\n",
3358 command->group_as_string);
3362 debug_printf_parse("parse_group return 0\n");
3364 /* command remains "open", available for possible redirects */
3367 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3368 /* Subroutines for copying $(...) and `...` things */
3369 static void add_till_backquote(o_string *dest, struct in_str *input);
3371 static void add_till_single_quote(o_string *dest, struct in_str *input)
3374 int ch = i_getch(input);
3376 syntax_error_unterm_ch('\'');
3377 /*xfunc_die(); - redundant */
3384 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3385 static void add_till_double_quote(o_string *dest, struct in_str *input)
3388 int ch = i_getch(input);
3390 syntax_error_unterm_ch('"');
3391 /*xfunc_die(); - redundant */
3395 if (ch == '\\') { /* \x. Copy both chars. */
3397 ch = i_getch(input);
3401 add_till_backquote(dest, input);
3405 //if (ch == '$') ...
3408 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3410 * "Within the backquoted style of command substitution, backslash
3411 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3412 * The search for the matching backquote shall be satisfied by the first
3413 * backquote found without a preceding backslash; during this search,
3414 * if a non-escaped backquote is encountered within a shell comment,
3415 * a here-document, an embedded command substitution of the $(command)
3416 * form, or a quoted string, undefined results occur. A single-quoted
3417 * or double-quoted string that begins, but does not end, within the
3418 * "`...`" sequence produces undefined results."
3420 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3422 static void add_till_backquote(o_string *dest, struct in_str *input)
3425 int ch = i_getch(input);
3427 syntax_error_unterm_ch('`');
3428 /*xfunc_die(); - redundant */
3433 /* \x. Copy both chars unless it is \` */
3434 int ch2 = i_getch(input);
3436 syntax_error_unterm_ch('`');
3437 /*xfunc_die(); - redundant */
3439 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3446 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3447 * quoting and nested ()s.
3448 * "With the $(command) style of command substitution, all characters
3449 * following the open parenthesis to the matching closing parenthesis
3450 * constitute the command. Any valid shell script can be used for command,
3451 * except a script consisting solely of redirections which produces
3452 * unspecified results."
3454 * echo $(echo '(TEST)' BEST) (TEST) BEST
3455 * echo $(echo 'TEST)' BEST) TEST) BEST
3456 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3458 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3459 * can contain arbitrary constructs, just like $(cmd).
3460 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3461 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3463 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3464 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3467 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3468 # if ENABLE_HUSH_BASH_COMPAT
3469 char end_char2 = end_ch >> 8;
3471 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3474 ch = i_getch(input);
3476 syntax_error_unterm_ch(end_ch);
3477 /*xfunc_die(); - redundant */
3479 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3482 /* we look for closing )) of $((EXPR)) */
3483 if (i_peek(input) == end_ch) {
3484 i_getch(input); /* eat second ')' */
3489 if (ch == '(' || ch == '{') {
3490 ch = (ch == '(' ? ')' : '}');
3491 add_till_closing_bracket(dest, input, ch);
3496 add_till_single_quote(dest, input);
3501 add_till_double_quote(dest, input);
3506 add_till_backquote(dest, input);
3511 /* \x. Copy verbatim. Important for \(, \) */
3512 ch = i_getch(input);
3514 syntax_error_unterm_ch(')');
3515 /*xfunc_die(); - redundant */
3523 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3525 /* Return code: 0 for OK, 1 for syntax error */
3527 #define parse_dollar(as_string, dest, input) \
3528 parse_dollar(dest, input)
3529 #define as_string NULL
3531 static int parse_dollar(o_string *as_string,
3533 struct in_str *input)
3535 int ch = i_peek(input); /* first character after the $ */
3536 unsigned char quote_mask = (dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS) ? 0x80 : 0;
3538 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3540 ch = i_getch(input);
3541 nommu_addchr(as_string, ch);
3543 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3545 debug_printf_parse(": '%c'\n", ch);
3546 o_addchr(dest, ch | quote_mask);
3549 if (!isalnum(ch) && ch != '_')
3551 ch = i_getch(input);
3552 nommu_addchr(as_string, ch);
3554 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3555 } else if (isdigit(ch)) {
3557 ch = i_getch(input);
3558 nommu_addchr(as_string, ch);
3559 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3560 debug_printf_parse(": '%c'\n", ch);
3561 o_addchr(dest, ch | quote_mask);
3562 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3563 } else switch (ch) {
3565 case '!': /* last bg pid */
3566 case '?': /* last exit code */
3567 case '#': /* number of args */
3568 case '*': /* args */
3569 case '@': /* args */
3570 goto make_one_char_var;
3572 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3574 ch = i_getch(input); /* eat '{' */
3575 nommu_addchr(as_string, ch);
3577 ch = i_getch(input); /* first char after '{' */
3578 nommu_addchr(as_string, ch);
3579 /* It should be ${?}, or ${#var},
3580 * or even ${?+subst} - operator acting on a special variable,
3581 * or the beginning of variable name.
3583 if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
3585 syntax_error_unterm_str("${name}");
3586 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
3591 /* It's possible to just call add_till_closing_bracket() at this point.
3592 * However, this regresses some of our testsuite cases
3593 * which check invalid constructs like ${%}.
3594 * Oh well... let's check that the var name part is fine... */
3600 debug_printf_parse(": '%c'\n", ch);
3602 ch = i_getch(input);
3603 nommu_addchr(as_string, ch);
3607 if (!isalnum(ch) && ch != '_') {
3609 unsigned char last_ch;
3610 /* handle parameter expansions
3611 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3613 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3614 goto bad_dollar_syntax;
3616 /* Eat everything until closing '}' (or ':') */
3618 if (ENABLE_HUSH_BASH_COMPAT
3620 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3622 /* It's ${var:N[:M]} thing */
3623 end_ch = '}' * 0x100 + ':';
3625 if (ENABLE_HUSH_BASH_COMPAT
3628 /* It's ${var/[/]pattern[/repl]} thing */
3629 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3631 nommu_addchr(as_string, '/');
3634 end_ch = '}' * 0x100 + '/';
3640 #if ENABLE_HUSH_DOLLAR_OPS
3641 last_ch = add_till_closing_bracket(dest, input, end_ch);
3643 #error Simple code to only allow ${var} is not implemented
3646 o_addstr(as_string, dest->data + pos);
3647 o_addchr(as_string, last_ch);
3650 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3651 /* close the first block: */
3652 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3653 /* while parsing N from ${var:N[:M]}
3654 * or pattern from ${var/[/]pattern[/repl]} */
3655 if ((end_ch & 0xff) == last_ch) {
3656 /* got ':' or '/'- parse the rest */
3661 if (end_ch == '}' * 0x100 + ':') {
3662 /* it's ${var:N} - emulate :999999999 */
3663 o_addstr(dest, "999999999");
3664 } /* else: it's ${var/[/]pattern} */
3669 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3672 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3676 ch = i_getch(input);
3677 nommu_addchr(as_string, ch);
3678 # if ENABLE_SH_MATH_SUPPORT
3679 if (i_peek(input) == '(') {
3680 ch = i_getch(input);
3681 nommu_addchr(as_string, ch);
3682 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3683 o_addchr(dest, /*quote_mask |*/ '+');
3686 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
3688 o_addstr(as_string, dest->data + pos);
3689 o_addchr(as_string, ')');
3690 o_addchr(as_string, ')');
3692 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3696 # if ENABLE_HUSH_TICK
3697 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3698 o_addchr(dest, quote_mask | '`');
3701 add_till_closing_bracket(dest, input, ')');
3703 o_addstr(as_string, dest->data + pos);
3704 o_addchr(as_string, ')');
3706 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3712 ch = i_getch(input);
3713 nommu_addchr(as_string, ch);
3715 if (isalnum(ch)) { /* it's $_name or $_123 */
3720 /* TODO: $_ and $-: */
3721 /* $_ Shell or shell script name; or last argument of last command
3722 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
3723 * but in command's env, set to full pathname used to invoke it */
3724 /* $- Option flags set by set builtin or shell options (-i etc) */
3726 o_addQchr(dest, '$');
3728 debug_printf_parse("parse_dollar return 0\n");
3734 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
3735 parse_stream_dquoted(dest, input, dquote_end)
3736 #define as_string NULL
3738 static int parse_stream_dquoted(o_string *as_string,
3740 struct in_str *input,
3747 ch = i_getch(input);
3749 nommu_addchr(as_string, ch);
3750 if (ch == dquote_end) { /* may be only '"' or EOF */
3751 if (dest->o_assignment == NOT_ASSIGNMENT)
3752 dest->o_expflags ^= EXP_FLAG_ESC_GLOB_CHARS;
3753 debug_printf_parse("parse_stream_dquoted return 0\n");
3756 /* note: can't move it above ch == dquote_end check! */
3758 syntax_error_unterm_ch('"');
3759 /*xfunc_die(); - redundant */
3763 next = i_peek(input);
3765 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
3766 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3769 syntax_error("\\<eof>");
3773 * "The backslash retains its special meaning [in "..."]
3774 * only when followed by one of the following characters:
3775 * $, `, ", \, or <newline>. A double quote may be quoted
3776 * within double quotes by preceding it with a backslash."
3777 * NB: in (unquoted) heredoc, above does not apply to ".
3779 if (next == dquote_end || strchr("$`\\\n", next) != NULL) {
3780 ch = i_getch(input); /* eat next */
3782 goto again; /* skip \<newline> */
3783 } /* else: ch remains == '\\', and we double it */
3784 o_addqchr(dest, ch);
3785 nommu_addchr(as_string, ch);
3789 if (parse_dollar(as_string, dest, input) != 0) {
3790 debug_printf_parse("parse_stream_dquoted return 1: "
3791 "parse_dollar returned non-0\n");
3796 #if ENABLE_HUSH_TICK
3798 //unsigned pos = dest->length;
3799 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3800 o_addchr(dest, 0x80 | '`');
3801 add_till_backquote(dest, input);
3802 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3803 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3807 o_addQchr(dest, ch);
3813 * Scan input until EOF or end_trigger char.
3814 * Return a list of pipes to execute, or NULL on EOF
3815 * or if end_trigger character is met.
3816 * On syntax error, exit is shell is not interactive,
3817 * reset parsing machinery and start parsing anew,
3818 * or return ERR_PTR.
3820 static struct pipe *parse_stream(char **pstring,
3821 struct in_str *input,
3824 struct parse_context ctx;
3825 o_string dest = NULL_O_STRING;
3828 /* Single-quote triggers a bypass of the main loop until its mate is
3829 * found. When recursing, quote state is passed in via dest->o_expflags.
3831 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
3832 end_trigger ? end_trigger : 'X');
3835 /* If very first arg is "" or '', dest.data may end up NULL.
3836 * Preventing this: */
3837 o_addchr(&dest, '\0');
3840 /* We used to separate words on $IFS here. This was wrong.
3841 * $IFS is used only for word splitting when $var is expanded,
3842 * here we should use blank chars as separators, not $IFS
3845 reset: /* we come back here only on syntax errors in interactive shell */
3847 #if ENABLE_HUSH_INTERACTIVE
3848 input->promptmode = 0; /* PS1 */
3850 if (MAYBE_ASSIGNMENT != 0)
3851 dest.o_assignment = MAYBE_ASSIGNMENT;
3852 initialize_context(&ctx);
3855 const char *is_blank;
3856 const char *is_special;
3860 redir_type redir_style;
3862 ch = i_getch(input);
3863 debug_printf_parse(": ch=%c (%d) escape=%d\n",
3864 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3869 syntax_error_unterm_str("here document");
3872 /* end_trigger == '}' case errors out earlier,
3873 * checking only ')' */
3874 if (end_trigger == ')') {
3875 syntax_error_unterm_ch('('); /* exits */
3876 /* goto parse_error; */
3879 if (done_word(&dest, &ctx)) {
3883 done_pipe(&ctx, PIPE_SEQ);
3885 /* If we got nothing... */
3886 /* (this makes bare "&" cmd a no-op.
3887 * bash says: "syntax error near unexpected token '&'") */
3888 if (pi->num_cmds == 0
3889 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
3895 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
3897 *pstring = ctx.as_string.data;
3899 o_free_unsafe(&ctx.as_string);
3902 debug_printf_parse("parse_stream return %p\n", pi);
3905 nommu_addchr(&ctx.as_string, ch);
3909 next = i_peek(input);
3911 is_special = "{}<>;&|()#'" /* special outside of "str" */
3912 "\\$\"" IF_HUSH_TICK("`"); /* always special */
3913 /* Are { and } special here? */
3914 if (ctx.command->argv /* word [word]{... - non-special */
3915 || dest.length /* word{... - non-special */
3916 || dest.has_quoted_part /* ""{... - non-special */
3917 || (next != ';' /* }; - special */
3918 && next != ')' /* }) - special */
3919 && next != '&' /* }& and }&& ... - special */
3920 && next != '|' /* }|| ... - special */
3921 && !strchr(defifs, next) /* {word - non-special */
3924 /* They are not special, skip "{}" */
3927 is_special = strchr(is_special, ch);
3928 is_blank = strchr(defifs, ch);
3930 if (!is_special && !is_blank) { /* ordinary char */
3932 o_addQchr(&dest, ch);
3933 if ((dest.o_assignment == MAYBE_ASSIGNMENT
3934 || dest.o_assignment == WORD_IS_KEYWORD)
3936 && is_well_formed_var_name(dest.data, '=')
3938 dest.o_assignment = DEFINITELY_ASSIGNMENT;
3944 if (done_word(&dest, &ctx)) {
3948 #if ENABLE_HUSH_CASE
3949 /* "case ... in <newline> word) ..." -
3950 * newlines are ignored (but ';' wouldn't be) */
3951 if (ctx.command->argv == NULL
3952 && ctx.ctx_res_w == RES_MATCH
3957 /* Treat newline as a command separator. */
3958 done_pipe(&ctx, PIPE_SEQ);
3959 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
3961 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
3966 dest.o_assignment = MAYBE_ASSIGNMENT;
3968 /* note: if (is_blank) continue;
3969 * will still trigger for us */
3973 /* "cmd}" or "cmd }..." without semicolon or &:
3974 * } is an ordinary char in this case, even inside { cmd; }
3975 * Pathological example: { ""}; } should exec "}" cmd
3978 if (!IS_NULL_CMD(ctx.command) /* cmd } */
3979 || dest.length != 0 /* word} */
3980 || dest.has_quoted_part /* ""} */
3984 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
3985 goto skip_end_trigger;
3986 /* else: } does terminate a group */
3989 if (end_trigger && end_trigger == ch
3990 && (ch != ';' || heredoc_cnt == 0)
3991 #if ENABLE_HUSH_CASE
3993 || ctx.ctx_res_w != RES_MATCH
3994 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
3999 /* This is technically valid:
4000 * { cat <<HERE; }; echo Ok
4004 * but we don't support this.
4005 * We require heredoc to be in enclosing {}/(),
4008 syntax_error_unterm_str("here document");
4011 if (done_word(&dest, &ctx)) {
4014 done_pipe(&ctx, PIPE_SEQ);
4015 dest.o_assignment = MAYBE_ASSIGNMENT;
4016 /* Do we sit outside of any if's, loops or case's? */
4018 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4022 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4024 *pstring = ctx.as_string.data;
4026 o_free_unsafe(&ctx.as_string);
4029 debug_printf_parse("parse_stream return %p: "
4030 "end_trigger char found\n",
4032 return ctx.list_head;
4039 /* Catch <, > before deciding whether this word is
4040 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4043 redir_fd = redirect_opt_num(&dest);
4044 if (done_word(&dest, &ctx)) {
4047 redir_style = REDIRECT_OVERWRITE;
4049 redir_style = REDIRECT_APPEND;
4050 ch = i_getch(input);
4051 nommu_addchr(&ctx.as_string, ch);
4054 else if (next == '(') {
4055 syntax_error(">(process) not supported");
4059 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4061 continue; /* back to top of while (1) */
4063 redir_fd = redirect_opt_num(&dest);
4064 if (done_word(&dest, &ctx)) {
4067 redir_style = REDIRECT_INPUT;
4069 redir_style = REDIRECT_HEREDOC;
4071 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4072 ch = i_getch(input);
4073 nommu_addchr(&ctx.as_string, ch);
4074 } else if (next == '>') {
4075 redir_style = REDIRECT_IO;
4076 ch = i_getch(input);
4077 nommu_addchr(&ctx.as_string, ch);
4080 else if (next == '(') {
4081 syntax_error("<(process) not supported");
4085 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4087 continue; /* back to top of while (1) */
4090 if (dest.o_assignment == MAYBE_ASSIGNMENT
4091 /* check that we are not in word in "a=1 2>word b=1": */
4092 && !ctx.pending_redirect
4094 /* ch is a special char and thus this word
4095 * cannot be an assignment */
4096 dest.o_assignment = NOT_ASSIGNMENT;
4099 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4103 if (dest.length == 0) {
4106 if (ch == EOF || ch == '\n')
4109 /* note: we do not add it to &ctx.as_string */
4111 nommu_addchr(&ctx.as_string, '\n');
4113 o_addQchr(&dest, ch);
4118 syntax_error("\\<eof>");
4121 ch = i_getch(input);
4123 o_addchr(&dest, '\\');
4124 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4125 o_addchr(&dest, ch);
4126 nommu_addchr(&ctx.as_string, ch);
4127 /* Example: echo Hello \2>file
4128 * we need to know that word 2 is quoted */
4129 dest.has_quoted_part = 1;
4133 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
4134 ctx.as_string.data[--ctx.as_string.length] = '\0';
4139 if (parse_dollar(&ctx.as_string, &dest, input) != 0) {
4140 debug_printf_parse("parse_stream parse error: "
4141 "parse_dollar returned non-0\n");
4146 dest.has_quoted_part = 1;
4148 ch = i_getch(input);
4150 syntax_error_unterm_ch('\'');
4151 /*xfunc_die(); - redundant */
4153 nommu_addchr(&ctx.as_string, ch);
4156 o_addqchr(&dest, ch);
4160 dest.has_quoted_part = 1;
4161 if (dest.o_assignment == NOT_ASSIGNMENT)
4162 dest.o_expflags ^= EXP_FLAG_ESC_GLOB_CHARS;
4163 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"'))
4166 #if ENABLE_HUSH_TICK
4170 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4171 o_addchr(&dest, '`');
4173 add_till_backquote(&dest, input);
4175 o_addstr(&ctx.as_string, dest.data + pos);
4176 o_addchr(&ctx.as_string, '`');
4178 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4179 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4184 #if ENABLE_HUSH_CASE
4187 if (done_word(&dest, &ctx)) {
4190 done_pipe(&ctx, PIPE_SEQ);
4191 #if ENABLE_HUSH_CASE
4192 /* Eat multiple semicolons, detect
4193 * whether it means something special */
4198 ch = i_getch(input);
4199 nommu_addchr(&ctx.as_string, ch);
4200 if (ctx.ctx_res_w == RES_CASE_BODY) {
4201 ctx.ctx_dsemicolon = 1;
4202 ctx.ctx_res_w = RES_MATCH;
4208 /* We just finished a cmd. New one may start
4209 * with an assignment */
4210 dest.o_assignment = MAYBE_ASSIGNMENT;
4213 if (done_word(&dest, &ctx)) {
4217 ch = i_getch(input);
4218 nommu_addchr(&ctx.as_string, ch);
4219 done_pipe(&ctx, PIPE_AND);
4221 done_pipe(&ctx, PIPE_BG);
4225 if (done_word(&dest, &ctx)) {
4228 #if ENABLE_HUSH_CASE
4229 if (ctx.ctx_res_w == RES_MATCH)
4230 break; /* we are in case's "word | word)" */
4232 if (next == '|') { /* || */
4233 ch = i_getch(input);
4234 nommu_addchr(&ctx.as_string, ch);
4235 done_pipe(&ctx, PIPE_OR);
4237 /* we could pick up a file descriptor choice here
4238 * with redirect_opt_num(), but bash doesn't do it.
4239 * "echo foo 2| cat" yields "foo 2". */
4242 o_reset_to_empty_unquoted(&ctx.as_string);
4247 #if ENABLE_HUSH_CASE
4248 /* "case... in [(]word)..." - skip '(' */
4249 if (ctx.ctx_res_w == RES_MATCH
4250 && ctx.command->argv == NULL /* not (word|(... */
4251 && dest.length == 0 /* not word(... */
4252 && dest.has_quoted_part == 0 /* not ""(... */
4258 if (parse_group(&dest, &ctx, input, ch) != 0) {
4263 #if ENABLE_HUSH_CASE
4264 if (ctx.ctx_res_w == RES_MATCH)
4268 /* proper use of this character is caught by end_trigger:
4269 * if we see {, we call parse_group(..., end_trigger='}')
4270 * and it will match } earlier (not here). */
4271 syntax_error_unexpected_ch(ch);
4275 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4281 struct parse_context *pctx;
4282 IF_HAS_KEYWORDS(struct parse_context *p2;)
4284 /* Clean up allocated tree.
4285 * Sample for finding leaks on syntax error recovery path.
4286 * Run it from interactive shell, watch pmap `pidof hush`.
4287 * while if false; then false; fi; do break; fi
4288 * Samples to catch leaks at execution:
4289 * while if (true | {true;}); then echo ok; fi; do break; done
4290 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4294 /* Update pipe/command counts,
4295 * otherwise freeing may miss some */
4296 done_pipe(pctx, PIPE_SEQ);
4297 debug_printf_clean("freeing list %p from ctx %p\n",
4298 pctx->list_head, pctx);
4299 debug_print_tree(pctx->list_head, 0);
4300 free_pipe_list(pctx->list_head);
4301 debug_printf_clean("freed list %p\n", pctx->list_head);
4303 o_free_unsafe(&pctx->as_string);
4305 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4309 IF_HAS_KEYWORDS(pctx = p2;)
4310 } while (HAS_KEYWORDS && pctx);
4311 /* Free text, clear all dest fields */
4313 /* If we are not in top-level parse, we return,
4314 * our caller will propagate error.
4316 if (end_trigger != ';') {
4324 /* Discard cached input, force prompt */
4326 IF_HUSH_INTERACTIVE(input->promptme = 1;)
4332 /*** Execution routines ***/
4334 /* Expansion can recurse, need forward decls: */
4335 static char *expand_string_to_string(const char *str);
4336 static int process_command_subs(o_string *dest, const char *s);
4338 /* expand_strvec_to_strvec() takes a list of strings, expands
4339 * all variable references within and returns a pointer to
4340 * a list of expanded strings, possibly with larger number
4341 * of strings. (Think VAR="a b"; echo $VAR).
4342 * This new list is allocated as a single malloc block.
4343 * NULL-terminated list of char* pointers is at the beginning of it,
4344 * followed by strings themselves.
4345 * Caller can deallocate entire list by single free(list). */
4347 /* Store given string, finalizing the word and starting new one whenever
4348 * we encounter IFS char(s). This is used for expanding variable values.
4349 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
4350 static int expand_on_ifs(o_string *output, int n, const char *str)
4353 int word_len = strcspn(str, G.ifs);
4355 if (output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
4356 o_addqblock(output, str, word_len);
4357 else if (!(output->o_expflags & EXP_FLAG_GLOB))
4358 o_addblock(output, str, word_len);
4359 else /* if (!escape && glob) */ {
4360 /* Protect backslashes against globbing up :)
4361 * Example: "v='\*'; echo b$v"
4363 o_addblock_duplicate_backslash(output, str, word_len);
4364 /*/ Why can't we do it easier? */
4365 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4366 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4370 if (!*str) /* EOL - do not finalize word */
4372 o_addchr(output, '\0');
4373 debug_print_list("expand_on_ifs", output, n);
4374 n = o_save_ptr(output, n);
4375 str += strspn(str, G.ifs); /* skip ifs chars */
4377 debug_print_list("expand_on_ifs[1]", output, n);
4381 /* Helper to expand $((...)) and heredoc body. These act as if
4382 * they are in double quotes, with the exception that they are not :).
4383 * Just the rules are similar: "expand only $var and `cmd`"
4385 * Returns malloced string.
4386 * As an optimization, we return NULL if expansion is not needed.
4388 static char *expand_pseudo_dquoted(const char *str)
4391 struct in_str input;
4392 o_string dest = NULL_O_STRING;
4394 if (!strchr(str, '$')
4395 && !strchr(str, '\\')
4396 #if ENABLE_HUSH_TICK
4397 && !strchr(str, '`')
4403 /* We need to expand. Example:
4404 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4406 setup_string_in_str(&input, str);
4407 parse_stream_dquoted(NULL, &dest, &input, EOF);
4408 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4409 exp_str = expand_string_to_string(dest.data);
4410 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4411 o_free_unsafe(&dest);
4415 #if ENABLE_SH_MATH_SUPPORT
4416 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
4418 arith_eval_hooks_t hooks;
4422 hooks.lookupvar = get_local_var_value;
4423 hooks.setvar = set_local_var_from_halves;
4424 //hooks.endofname = endofname;
4425 exp_str = expand_pseudo_dquoted(arg);
4426 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
4432 #if ENABLE_HUSH_BASH_COMPAT
4433 /* ${var/[/]pattern[/repl]} helpers */
4434 static char *strstr_pattern(char *val, const char *pattern, int *size)
4437 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4438 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4445 /* Optimization: if "*pat" did not match the start of "string",
4446 * we know that "tring", "ring" etc will not match too:
4448 if (pattern[0] == '*')
4453 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4455 char *result = NULL;
4456 unsigned res_len = 0;
4457 unsigned repl_len = strlen(repl);
4461 char *s = strstr_pattern(val, pattern, &size);
4465 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4466 memcpy(result + res_len, val, s - val);
4468 strcpy(result + res_len, repl);
4469 res_len += repl_len;
4470 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4476 if (val[0] && result) {
4477 result = xrealloc(result, res_len + strlen(val) + 1);
4478 strcpy(result + res_len, val);
4479 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4481 debug_printf_varexp("result:'%s'\n", result);
4487 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4489 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp, char first_ch)
4491 const char *val = NULL;
4492 char *to_be_freed = NULL;
4497 char exp_save = exp_save; /* for compiler */
4498 char *exp_saveptr; /* points to expansion operator */
4499 char *exp_word = exp_word; /* for compiler */
4501 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4503 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4504 first_char = arg[0] = first_ch & 0x7f;
4507 if (first_char == '#' /* ${#... */
4508 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4510 /* It must be length operator: ${#var} */
4514 /* Maybe handle parameter expansion */
4515 if (exp_saveptr /* if 2nd char is one of expansion operators */
4516 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4518 /* ${?:0}, ${#[:]%0} etc */
4519 exp_saveptr = var + 1;
4521 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4522 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4524 exp_op = exp_save = *exp_saveptr;
4526 exp_word = exp_saveptr + 1;
4527 if (exp_op == ':') {
4528 exp_op = *exp_word++;
4529 //TODO: try ${var:} and ${var:bogus} in non-bash config
4530 if (ENABLE_HUSH_BASH_COMPAT
4531 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4533 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4538 *exp_saveptr = '\0';
4539 } /* else: it's not an expansion op, but bare ${var} */
4542 /* Look up the variable in question */
4543 if (isdigit(var[0])) {
4544 /* parse_dollar should have vetted var for us */
4545 int n = xatoi_positive(var);
4546 if (n < G.global_argc)
4547 val = G.global_argv[n];
4548 /* else val remains NULL: $N with too big N */
4552 val = utoa(G.root_pid);
4554 case '!': /* bg pid */
4555 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
4557 case '?': /* exitcode */
4558 val = utoa(G.last_exitcode);
4560 case '#': /* argc */
4561 val = utoa(G.global_argc ? G.global_argc-1 : 0);
4564 val = get_local_var_value(var);
4568 /* Handle any expansions */
4569 if (exp_op == 'L') {
4570 debug_printf_expand("expand: length(%s)=", val);
4571 val = utoa(val ? strlen(val) : 0);
4572 debug_printf_expand("%s\n", val);
4573 } else if (exp_op) {
4574 if (exp_op == '%' || exp_op == '#') {
4575 /* Standard-mandated substring removal ops:
4576 * ${parameter%word} - remove smallest suffix pattern
4577 * ${parameter%%word} - remove largest suffix pattern
4578 * ${parameter#word} - remove smallest prefix pattern
4579 * ${parameter##word} - remove largest prefix pattern
4581 * Word is expanded to produce a glob pattern.
4582 * Then var's value is matched to it and matching part removed.
4584 if (val && val[0]) {
4587 unsigned scan_flags = pick_scan(exp_op, *exp_word);
4588 if (exp_op == *exp_word) /* ## or %% */
4590 //TODO: avoid xstrdup unless needed
4591 // (see HACK ALERT below for an example)
4592 val = to_be_freed = xstrdup(val);
4593 //TODO: fix expansion rules:
4594 exp_exp_word = expand_pseudo_dquoted(exp_word);
4596 exp_word = exp_exp_word;
4597 loc = scan_and_match(to_be_freed, exp_word, scan_flags);
4598 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
4599 // exp_op, to_be_freed, exp_word, loc);
4601 if (loc) { /* match was found */
4602 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
4609 #if ENABLE_HUSH_BASH_COMPAT
4610 else if (exp_op == '/' || exp_op == '\\') {
4611 /* It's ${var/[/]pattern[/repl]} thing.
4612 * Note that in encoded form it has TWO parts:
4613 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4615 /* Empty variable always gives nothing: */
4616 // "v=''; echo ${v/*/w}" prints "", not "w"
4617 if (val && val[0]) {
4618 /* It's ${var/[/]pattern[/repl]} thing */
4620 * Pattern is taken literally, while
4621 * repl should be unbackslashed and globbed
4622 * by the usual expansion rules:
4624 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
4625 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
4626 * v='a bz'; echo ${v/a*z/a*z} prints "az"
4627 * v='a bz'; echo ${v/a*z/\z} prints "z"
4628 * (note that a*z _pattern_ is never globbed!)
4630 //TODO: fix expansion rules:
4631 char *pattern, *repl, *t;
4632 pattern = expand_pseudo_dquoted(exp_word);
4634 pattern = xstrdup(exp_word);
4635 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
4636 *p++ = SPECIAL_VAR_SYMBOL;
4638 p = strchr(p, SPECIAL_VAR_SYMBOL);
4640 repl = expand_pseudo_dquoted(exp_word);
4641 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
4642 /* HACK ALERT. We depend here on the fact that
4643 * G.global_argv and results of utoa and get_local_var_value
4644 * are actually in writable memory:
4645 * replace_pattern momentarily stores NULs there. */
4647 to_be_freed = replace_pattern(t,
4649 (repl ? repl : exp_word),
4651 if (to_be_freed) /* at least one replace happened */
4658 else if (exp_op == ':') {
4659 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
4660 /* It's ${var:N[:M]} bashism.
4661 * Note that in encoded form it has TWO parts:
4662 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
4667 beg = expand_and_evaluate_arith(exp_word, &errcode);
4668 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
4669 *p++ = SPECIAL_VAR_SYMBOL;
4671 p = strchr(p, SPECIAL_VAR_SYMBOL);
4673 len = expand_and_evaluate_arith(exp_word, &errcode);
4674 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
4676 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
4677 if (beg < 0) /* bash compat */
4679 debug_printf_varexp("from val:'%s'\n", val);
4680 if (len == 0 || !val || beg >= strlen(val))
4683 /* Paranoia. What if user entered 9999999999999
4684 * which fits in arith_t but not int? */
4687 val = to_be_freed = xstrndup(val + beg, len);
4689 debug_printf_varexp("val:'%s'\n", val);
4693 die_if_script("malformed ${%s:...}", var);
4696 } else { /* one of "-=+?" */
4697 /* Standard-mandated substitution ops:
4698 * ${var?word} - indicate error if unset
4699 * If var is unset, word (or a message indicating it is unset
4700 * if word is null) is written to standard error
4701 * and the shell exits with a non-zero exit status.
4702 * Otherwise, the value of var is substituted.
4703 * ${var-word} - use default value
4704 * If var is unset, word is substituted.
4705 * ${var=word} - assign and use default value
4706 * If var is unset, word is assigned to var.
4707 * In all cases, final value of var is substituted.
4708 * ${var+word} - use alternative value
4709 * If var is unset, null is substituted.
4710 * Otherwise, word is substituted.
4712 * Word is subjected to tilde expansion, parameter expansion,
4713 * command substitution, and arithmetic expansion.
4714 * If word is not needed, it is not expanded.
4716 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
4717 * but also treat null var as if it is unset.
4719 int use_word = (!val || ((exp_save == ':') && !val[0]));
4721 use_word = !use_word;
4722 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
4723 (exp_save == ':') ? "true" : "false", use_word);
4725 to_be_freed = expand_pseudo_dquoted(exp_word);
4727 exp_word = to_be_freed;
4728 if (exp_op == '?') {
4729 /* mimic bash message */
4730 die_if_script("%s: %s",
4732 exp_word[0] ? exp_word : "parameter null or not set"
4734 //TODO: how interactive bash aborts expansion mid-command?
4739 if (exp_op == '=') {
4740 /* ${var=[word]} or ${var:=[word]} */
4741 if (isdigit(var[0]) || var[0] == '#') {
4742 /* mimic bash message */
4743 die_if_script("$%s: cannot assign in this way", var);
4746 char *new_var = xasprintf("%s=%s", var, val);
4747 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4751 } /* one of "-=+?" */
4753 *exp_saveptr = exp_save;
4759 *to_be_freed_pp = to_be_freed;
4763 /* Expand all variable references in given string, adding words to list[]
4764 * at n, n+1,... positions. Return updated n (so that list[n] is next one
4765 * to be filled). This routine is extremely tricky: has to deal with
4766 * variables/parameters with whitespace, $* and $@, and constructs like
4767 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
4768 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
4770 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
4771 * expansion of right-hand side of assignment == 1-element expand.
4778 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
4779 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
4780 debug_print_list("expand_vars_to_list", output, n);
4781 n = o_save_ptr(output, n);
4782 debug_print_list("expand_vars_to_list[0]", output, n);
4784 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
4786 char *to_be_freed = NULL;
4787 const char *val = NULL;
4788 #if ENABLE_HUSH_TICK
4789 o_string subst_result = NULL_O_STRING;
4791 #if ENABLE_SH_MATH_SUPPORT
4792 char arith_buf[sizeof(arith_t)*3 + 2];
4794 o_addblock(output, arg, p - arg);
4795 debug_print_list("expand_vars_to_list[1]", output, n);
4797 p = strchr(p, SPECIAL_VAR_SYMBOL);
4799 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
4800 /* "$@" is special. Even if quoted, it can still
4801 * expand to nothing (not even an empty string) */
4802 if ((first_ch & 0x7f) != '@')
4803 ored_ch |= first_ch;
4805 switch (first_ch & 0x7f) {
4806 /* Highest bit in first_ch indicates that var is double-quoted */
4810 if (!G.global_argv[1])
4813 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
4814 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
4815 int sv = output->o_expflags;
4816 /* unquoted var's contents should be globbed, so don't escape */
4817 output->o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4818 while (G.global_argv[i]) {
4819 n = expand_on_ifs(output, n, G.global_argv[i]);
4820 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
4821 if (G.global_argv[i++][0] && G.global_argv[i]) {
4822 /* this argv[] is not empty and not last:
4823 * put terminating NUL, start new word */
4824 o_addchr(output, '\0');
4825 debug_print_list("expand_vars_to_list[2]", output, n);
4826 n = o_save_ptr(output, n);
4827 debug_print_list("expand_vars_to_list[3]", output, n);
4830 output->o_expflags = sv;
4832 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
4833 * and in this case should treat it like '$*' - see 'else...' below */
4834 if (first_ch == ('@'|0x80) /* quoted $@ */
4835 && !(output->o_expflags & EXP_FLAG_SINGLEWORD)
4838 o_addQstr(output, G.global_argv[i]);
4839 if (++i >= G.global_argc)
4841 o_addchr(output, '\0');
4842 debug_print_list("expand_vars_to_list[4]", output, n);
4843 n = o_save_ptr(output, n);
4845 } else { /* quoted $*: add as one word */
4847 o_addQstr(output, G.global_argv[i]);
4848 if (!G.global_argv[++i])
4851 o_addchr(output, G.ifs[0]);
4856 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
4857 /* "Empty variable", used to make "" etc to not disappear */
4861 #if ENABLE_HUSH_TICK
4862 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
4865 /* Can't just stuff it into output o_string,
4866 * expanded result may need to be globbed
4867 * and $IFS-splitted */
4868 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
4869 G.last_exitcode = process_command_subs(&subst_result, arg);
4870 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
4871 val = subst_result.data;
4874 #if ENABLE_SH_MATH_SUPPORT
4875 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
4879 arg++; /* skip '+' */
4880 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
4881 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
4882 res = expand_and_evaluate_arith(arg, &errcode);
4885 const char *msg = "error in arithmetic";
4888 msg = "exponent less than 0";
4891 msg = "divide by 0";
4894 msg = "expression recursion loop detected";
4899 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
4900 sprintf(arith_buf, arith_t_fmt, res);
4906 val = expand_one_var(&to_be_freed, arg, &p, first_ch);
4907 IF_HUSH_TICK(store_val:)
4908 if (!(first_ch & 0x80)) { /* unquoted $VAR */
4909 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
4910 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4911 if (val && val[0]) {
4912 /* unquoted var's contents should be globbed, so don't escape */
4913 int sv = output->o_expflags;
4914 output->o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4915 n = expand_on_ifs(output, n, val);
4917 output->o_expflags = sv;
4919 } else { /* quoted $VAR, val will be appended below */
4920 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
4921 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4925 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
4927 if (val && val[0]) {
4928 o_addQstr(output, val);
4931 /* Do the check to avoid writing to a const string */
4932 if (*p != SPECIAL_VAR_SYMBOL)
4933 *p = SPECIAL_VAR_SYMBOL;
4935 #if ENABLE_HUSH_TICK
4936 o_free(&subst_result);
4939 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
4942 debug_print_list("expand_vars_to_list[a]", output, n);
4943 /* this part is literal, and it was already pre-quoted
4944 * if needed (much earlier), do not use o_addQstr here! */
4945 o_addstr_with_NUL(output, arg);
4946 debug_print_list("expand_vars_to_list[b]", output, n);
4947 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
4948 && !(ored_ch & 0x80) /* and all vars were not quoted. */
4951 /* allow to reuse list[n] later without re-growth */
4952 output->has_empty_slot = 1;
4954 o_addchr(output, '\0');
4960 static char **expand_variables(char **argv, unsigned expflags)
4964 o_string output = NULL_O_STRING;
4966 output.o_expflags = expflags;
4970 n = expand_vars_to_list(&output, n, *argv);
4973 debug_print_list("expand_variables", &output, n);
4975 /* output.data (malloced in one block) gets returned in "list" */
4976 list = o_finalize_list(&output, n);
4977 debug_print_strings("expand_variables[1]", list);
4981 static char **expand_strvec_to_strvec(char **argv)
4983 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
4986 #if ENABLE_HUSH_BASH_COMPAT
4987 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
4989 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
4993 /* Used for expansion of right hand of assignments,
4994 * $((...)), heredocs, variable espansion parts.
4996 * NB: should NOT do globbing!
4997 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
4999 static char *expand_string_to_string(const char *str)
5001 char *argv[2], **list;
5003 /* This is generally an optimization, but it also
5004 * handles "", which otherwise trips over !list[0] check below.
5005 * (is this ever happens that we actually get str="" here?)
5007 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5008 //TODO: Can use on strings with \ too, just unbackslash() them?
5009 debug_printf_expand("string_to_string(fast)='%s'\n", str);
5010 return xstrdup(str);
5013 argv[0] = (char*)str;
5015 list = expand_variables(argv, EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD);
5017 if (!list[0] || list[1])
5018 bb_error_msg_and_die("BUG in varexp2");
5019 /* actually, just move string 2*sizeof(char*) bytes back */
5020 overlapping_strcpy((char*)list, list[0]);
5021 unbackslash((char*)list);
5022 debug_printf_expand("string_to_string='%s'\n", (char*)list);
5026 /* Used for "eval" builtin */
5027 static char* expand_strvec_to_string(char **argv)
5031 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5032 /* Convert all NULs to spaces */
5037 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5038 bb_error_msg_and_die("BUG in varexp3");
5039 /* bash uses ' ' regardless of $IFS contents */
5044 overlapping_strcpy((char*)list, list[0]);
5045 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5049 static char **expand_assignments(char **argv, int count)
5054 G.expanded_assignments = p = NULL;
5055 /* Expand assignments into one string each */
5056 for (i = 0; i < count; i++) {
5057 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i]));
5059 G.expanded_assignments = NULL;
5066 void re_execute_shell(char ***to_free, const char *s,
5067 char *g_argv0, char **g_argv,
5068 char **builtin_argv) NORETURN;
5070 static void reset_traps_to_defaults(void)
5072 /* This function is always called in a child shell
5073 * after fork (not vfork, NOMMU doesn't use this function).
5078 /* Child shells are not interactive.
5079 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5080 * Testcase: (while :; do :; done) + ^Z should background.
5081 * Same goes for SIGTERM, SIGHUP, SIGINT.
5083 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
5084 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
5086 /* Switching off SPECIAL_INTERACTIVE_SIGS.
5087 * Stupid. It can be done with *single* &= op, but we can't use
5088 * the fact that G.blocked_set is implemented as a bitmask
5090 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
5094 /* Careful. Only if no trap or trap is not "" */
5095 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
5096 sigdelset(&G.blocked_set, sig);
5103 /* Our homegrown sig mask is saner to work with :) */
5104 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5106 /* Resetting all traps to default except empty ones */
5107 mask = G.non_DFL_mask;
5108 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
5109 if (!G.traps[sig] || !G.traps[sig][0])
5112 G.traps[sig] = NULL;
5113 /* There is no signal for 0 (EXIT) */
5116 /* There was a trap handler, we just removed it.
5117 * But if sig still has non-DFL handling,
5118 * we should not unblock the sig. */
5121 sigdelset(&G.blocked_set, sig);
5123 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5128 static void re_execute_shell(char ***to_free, const char *s,
5129 char *g_argv0, char **g_argv,
5130 char **builtin_argv) NORETURN;
5131 static void re_execute_shell(char ***to_free, const char *s,
5132 char *g_argv0, char **g_argv,
5133 char **builtin_argv)
5135 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5136 /* delims + 2 * (number of bytes in printed hex numbers) */
5137 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5138 char *heredoc_argv[4];
5139 struct variable *cur;
5140 # if ENABLE_HUSH_FUNCTIONS
5141 struct function *funcp;
5145 unsigned long long empty_trap_mask;
5147 if (!g_argv0) { /* heredoc */
5148 argv = heredoc_argv;
5149 argv[0] = (char *) G.argv0_for_re_execing;
5150 argv[1] = (char *) "-<";
5151 argv[2] = (char *) s;
5153 pp = &argv[3]; /* used as pointer to empty environment */
5159 if (pp) while (*pp++)
5162 empty_trap_mask = 0;
5165 for (sig = 1; sig < NSIG; sig++) {
5166 if (G.traps[sig] && !G.traps[sig][0])
5167 empty_trap_mask |= 1LL << sig;
5171 sprintf(param_buf, NOMMU_HACK_FMT
5172 , (unsigned) G.root_pid
5173 , (unsigned) G.root_ppid
5174 , (unsigned) G.last_bg_pid
5175 , (unsigned) G.last_exitcode
5178 IF_HUSH_LOOPS(, G.depth_of_loop)
5180 # undef NOMMU_HACK_FMT
5181 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5182 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5185 for (cur = G.top_var; cur; cur = cur->next) {
5186 if (!cur->flg_export || cur->flg_read_only)
5189 # if ENABLE_HUSH_FUNCTIONS
5190 for (funcp = G.top_func; funcp; funcp = funcp->next)
5196 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5197 *pp++ = (char *) G.argv0_for_re_execing;
5199 for (cur = G.top_var; cur; cur = cur->next) {
5200 if (strcmp(cur->varstr, hush_version_str) == 0)
5202 if (cur->flg_read_only) {
5203 *pp++ = (char *) "-R";
5204 *pp++ = cur->varstr;
5205 } else if (!cur->flg_export) {
5206 *pp++ = (char *) "-V";
5207 *pp++ = cur->varstr;
5210 # if ENABLE_HUSH_FUNCTIONS
5211 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5212 *pp++ = (char *) "-F";
5213 *pp++ = funcp->name;
5214 *pp++ = funcp->body_as_string;
5217 /* We can pass activated traps here. Say, -Tnn:trap_string
5219 * However, POSIX says that subshells reset signals with traps
5221 * I tested bash-3.2 and it not only does that with true subshells
5222 * of the form ( list ), but with any forked children shells.
5223 * I set trap "echo W" WINCH; and then tried:
5225 * { echo 1; sleep 20; echo 2; } &
5226 * while true; do echo 1; sleep 20; echo 2; break; done &
5227 * true | { echo 1; sleep 20; echo 2; } | cat
5229 * In all these cases sending SIGWINCH to the child shell
5230 * did not run the trap. If I add trap "echo V" WINCH;
5231 * _inside_ group (just before echo 1), it works.
5233 * I conclude it means we don't need to pass active traps here.
5234 * Even if we would use signal handlers instead of signal masking
5235 * in order to implement trap handling,
5236 * exec syscall below resets signals to SIG_DFL for us.
5238 *pp++ = (char *) "-c";
5241 while (*++builtin_argv)
5242 *pp++ = *builtin_argv;
5243 *pp++ = (char *) "";
5248 /* *pp = NULL; - is already there */
5252 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5253 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5254 execve(bb_busybox_exec_path, argv, pp);
5255 /* Fallback. Useful for init=/bin/hush usage etc */
5256 if (argv[0][0] == '/')
5257 execve(argv[0], argv, pp);
5258 xfunc_error_retval = 127;
5259 bb_error_msg_and_die("can't re-execute the shell");
5261 #endif /* !BB_MMU */
5264 static int run_and_free_list(struct pipe *pi);
5266 /* Executing from string: eval, sh -c '...'
5267 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5268 * end_trigger controls how often we stop parsing
5269 * NUL: parse all, execute, return
5270 * ';': parse till ';' or newline, execute, repeat till EOF
5272 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5274 /* Why we need empty flag?
5275 * An obscure corner case "false; ``; echo $?":
5276 * empty command in `` should still set $? to 0.
5277 * But we can't just set $? to 0 at the start,
5278 * this breaks "false; echo `echo $?`" case.
5282 struct pipe *pipe_list;
5284 pipe_list = parse_stream(NULL, inp, end_trigger);
5285 if (!pipe_list) { /* EOF */
5287 G.last_exitcode = 0;
5290 debug_print_tree(pipe_list, 0);
5291 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5292 run_and_free_list(pipe_list);
5297 static void parse_and_run_string(const char *s)
5299 struct in_str input;
5300 setup_string_in_str(&input, s);
5301 parse_and_run_stream(&input, '\0');
5304 static void parse_and_run_file(FILE *f)
5306 struct in_str input;
5307 setup_file_in_str(&input, f);
5308 parse_and_run_stream(&input, ';');
5311 #if ENABLE_HUSH_TICK
5312 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5317 char **to_free = NULL;
5321 pid = BB_MMU ? xfork() : xvfork();
5322 if (pid == 0) { /* child */
5323 disable_restore_tty_pgrp_on_exit();
5324 /* Process substitution is not considered to be usual
5325 * 'command execution'.
5326 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5333 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5334 close(channel[0]); /* NB: close _first_, then move fd! */
5335 xmove_fd(channel[1], 1);
5336 /* Prevent it from trying to handle ctrl-z etc */
5337 IF_HUSH_JOB(G.run_list_level = 1;)
5338 /* Awful hack for `trap` or $(trap).
5340 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5341 * contains an example where "trap" is executed in a subshell:
5343 * save_traps=$(trap)
5345 * eval "$save_traps"
5347 * Standard does not say that "trap" in subshell shall print
5348 * parent shell's traps. It only says that its output
5349 * must have suitable form, but then, in the above example
5350 * (which is not supposed to be normative), it implies that.
5352 * bash (and probably other shell) does implement it
5353 * (traps are reset to defaults, but "trap" still shows them),
5354 * but as a result, "trap" logic is hopelessly messed up:
5357 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5358 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5359 * # true | trap <--- trap is in subshell - no output (ditto)
5360 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5361 * trap -- 'echo Ho' SIGWINCH
5362 * # echo `(trap)` <--- in subshell in subshell - output
5363 * trap -- 'echo Ho' SIGWINCH
5364 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5365 * trap -- 'echo Ho' SIGWINCH
5367 * The rules when to forget and when to not forget traps
5368 * get really complex and nonsensical.
5370 * Our solution: ONLY bare $(trap) or `trap` is special.
5372 s = skip_whitespace(s);
5373 if (strncmp(s, "trap", 4) == 0
5374 && skip_whitespace(s + 4)[0] == '\0'
5376 static const char *const argv[] = { NULL, NULL };
5377 builtin_trap((char**)argv);
5378 exit(0); /* not _exit() - we need to fflush */
5381 reset_traps_to_defaults();
5382 parse_and_run_string(s);
5383 _exit(G.last_exitcode);
5385 /* We re-execute after vfork on NOMMU. This makes this script safe:
5386 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5387 * huge=`cat BIG` # was blocking here forever
5390 re_execute_shell(&to_free,
5400 # if ENABLE_HUSH_FAST
5402 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5403 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5404 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5406 enable_restore_tty_pgrp_on_exit();
5411 close_on_exec_on(channel[0]);
5412 return xfdopen_for_read(channel[0]);
5415 /* Return code is exit status of the process that is run. */
5416 static int process_command_subs(o_string *dest, const char *s)
5419 struct in_str pipe_str;
5421 int status, ch, eol_cnt;
5423 fp = generate_stream_from_string(s, &pid);
5425 /* Now send results of command back into original context */
5426 setup_file_in_str(&pipe_str, fp);
5428 while ((ch = i_getch(&pipe_str)) != EOF) {
5434 o_addchr(dest, '\n');
5437 o_addQchr(dest, ch);
5440 debug_printf("done reading from `cmd` pipe, closing it\n");
5442 /* We need to extract exitcode. Test case
5443 * "true; echo `sleep 1; false` $?"
5445 safe_waitpid(pid, &status, 0);
5446 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5447 return WEXITSTATUS(status);
5449 #endif /* ENABLE_HUSH_TICK */
5452 static void setup_heredoc(struct redir_struct *redir)
5454 struct fd_pair pair;
5457 /* the _body_ of heredoc (misleading field name) */
5458 const char *heredoc = redir->rd_filename;
5465 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5466 expanded = expand_pseudo_dquoted(heredoc);
5470 len = strlen(heredoc);
5472 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5474 xmove_fd(pair.rd, redir->rd_fd);
5476 /* Try writing without forking. Newer kernels have
5477 * dynamically growing pipes. Must use non-blocking write! */
5480 written = write(pair.wr, heredoc, len);
5491 ndelay_off(pair.wr);
5493 /* Okay, pipe buffer was not big enough */
5494 /* Note: we must not create a stray child (bastard? :)
5495 * for the unsuspecting parent process. Child creates a grandchild
5496 * and exits before parent execs the process which consumes heredoc
5497 * (that exec happens after we return from this function) */
5504 disable_restore_tty_pgrp_on_exit();
5505 pid = BB_MMU ? xfork() : xvfork();
5509 close(redir->rd_fd); /* read side of the pipe */
5511 full_write(pair.wr, heredoc, len); /* may loop or block */
5514 /* Delegate blocking writes to another process */
5515 xmove_fd(pair.wr, STDOUT_FILENO);
5516 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
5520 #if ENABLE_HUSH_FAST
5522 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5524 enable_restore_tty_pgrp_on_exit();
5530 wait(NULL); /* wait till child has died */
5533 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
5534 * and stderr if they are redirected. */
5535 static int setup_redirects(struct command *prog, int squirrel[])
5538 struct redir_struct *redir;
5540 for (redir = prog->redirects; redir; redir = redir->next) {
5541 if (redir->rd_type == REDIRECT_HEREDOC2) {
5542 /* rd_fd<<HERE case */
5543 if (squirrel && redir->rd_fd < 3
5544 && squirrel[redir->rd_fd] < 0
5546 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5548 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
5550 debug_printf_parse("set heredoc '%s'\n",
5551 redir->rd_filename);
5552 setup_heredoc(redir);
5556 if (redir->rd_dup == REDIRFD_TO_FILE) {
5557 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
5559 if (redir->rd_filename == NULL) {
5560 /* Something went wrong in the parse.
5561 * Pretend it didn't happen */
5562 bb_error_msg("bug in redirect parse");
5565 mode = redir_table[redir->rd_type].mode;
5566 p = expand_string_to_string(redir->rd_filename);
5567 openfd = open_or_warn(p, mode);
5570 /* this could get lost if stderr has been redirected, but
5571 * bash and ash both lose it as well (though zsh doesn't!) */
5572 //what the above comment tries to say?
5576 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
5577 openfd = redir->rd_dup;
5580 if (openfd != redir->rd_fd) {
5581 if (squirrel && redir->rd_fd < 3
5582 && squirrel[redir->rd_fd] < 0
5584 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5586 if (openfd == REDIRFD_CLOSE) {
5587 /* "n>-" means "close me" */
5588 close(redir->rd_fd);
5590 xdup2(openfd, redir->rd_fd);
5591 if (redir->rd_dup == REDIRFD_TO_FILE)
5599 static void restore_redirects(int squirrel[])
5602 for (i = 0; i < 3; i++) {
5605 /* We simply die on error */
5611 static char *find_in_path(const char *arg)
5614 const char *PATH = get_local_var_value("PATH");
5620 const char *end = strchrnul(PATH, ':');
5621 int sz = end - PATH; /* must be int! */
5625 ret = xasprintf("%.*s/%s", sz, PATH, arg);
5627 /* We have xxx::yyyy in $PATH,
5628 * it means "use current dir" */
5631 if (access(ret, F_OK) == 0)
5644 static const struct built_in_command *find_builtin_helper(const char *name,
5645 const struct built_in_command *x,
5646 const struct built_in_command *end)
5649 if (strcmp(name, x->b_cmd) != 0) {
5653 debug_printf_exec("found builtin '%s'\n", name);
5658 static const struct built_in_command *find_builtin1(const char *name)
5660 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
5662 static const struct built_in_command *find_builtin(const char *name)
5664 const struct built_in_command *x = find_builtin1(name);
5667 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
5670 #if ENABLE_HUSH_FUNCTIONS
5671 static struct function **find_function_slot(const char *name)
5673 struct function **funcpp = &G.top_func;
5675 if (strcmp(name, (*funcpp)->name) == 0) {
5678 funcpp = &(*funcpp)->next;
5683 static const struct function *find_function(const char *name)
5685 const struct function *funcp = *find_function_slot(name);
5687 debug_printf_exec("found function '%s'\n", name);
5691 /* Note: takes ownership on name ptr */
5692 static struct function *new_function(char *name)
5694 struct function **funcpp = find_function_slot(name);
5695 struct function *funcp = *funcpp;
5697 if (funcp != NULL) {
5698 struct command *cmd = funcp->parent_cmd;
5699 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
5701 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
5703 /* Note: if !funcp->body, do not free body_as_string!
5704 * This is a special case of "-F name body" function:
5705 * body_as_string was not malloced! */
5707 free_pipe_list(funcp->body);
5709 free(funcp->body_as_string);
5713 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
5714 cmd->argv[0] = funcp->name;
5715 cmd->group = funcp->body;
5717 cmd->group_as_string = funcp->body_as_string;
5721 debug_printf_exec("remembering new function '%s'\n", name);
5722 funcp = *funcpp = xzalloc(sizeof(*funcp));
5723 /*funcp->next = NULL;*/
5730 static void unset_func(const char *name)
5732 struct function **funcpp = find_function_slot(name);
5733 struct function *funcp = *funcpp;
5735 if (funcp != NULL) {
5736 debug_printf_exec("freeing function '%s'\n", funcp->name);
5737 *funcpp = funcp->next;
5738 /* funcp is unlinked now, deleting it.
5739 * Note: if !funcp->body, the function was created by
5740 * "-F name body", do not free ->body_as_string
5741 * and ->name as they were not malloced. */
5743 free_pipe_list(funcp->body);
5746 free(funcp->body_as_string);
5754 #define exec_function(to_free, funcp, argv) \
5755 exec_function(funcp, argv)
5757 static void exec_function(char ***to_free,
5758 const struct function *funcp,
5759 char **argv) NORETURN;
5760 static void exec_function(char ***to_free,
5761 const struct function *funcp,
5767 argv[0] = G.global_argv[0];
5768 G.global_argv = argv;
5772 /* On MMU, funcp->body is always non-NULL */
5773 n = run_list(funcp->body);
5777 re_execute_shell(to_free,
5778 funcp->body_as_string,
5785 static int run_function(const struct function *funcp, char **argv)
5791 save_and_replace_G_args(&sv, argv);
5793 /* "we are in function, ok to use return" */
5794 sv_flg = G.flag_return_in_progress;
5795 G.flag_return_in_progress = -1;
5796 # if ENABLE_HUSH_LOCAL
5797 G.func_nest_level++;
5800 /* On MMU, funcp->body is always non-NULL */
5803 /* Function defined by -F */
5804 parse_and_run_string(funcp->body_as_string);
5805 rc = G.last_exitcode;
5809 rc = run_list(funcp->body);
5812 # if ENABLE_HUSH_LOCAL
5814 struct variable *var;
5815 struct variable **var_pp;
5817 var_pp = &G.top_var;
5818 while ((var = *var_pp) != NULL) {
5819 if (var->func_nest_level < G.func_nest_level) {
5820 var_pp = &var->next;
5824 if (var->flg_export)
5825 bb_unsetenv(var->varstr);
5826 /* Remove from global list */
5827 *var_pp = var->next;
5833 G.func_nest_level--;
5836 G.flag_return_in_progress = sv_flg;
5838 restore_G_args(&sv, argv);
5842 #endif /* ENABLE_HUSH_FUNCTIONS */
5846 #define exec_builtin(to_free, x, argv) \
5847 exec_builtin(x, argv)
5849 #define exec_builtin(to_free, x, argv) \
5850 exec_builtin(to_free, argv)
5852 static void exec_builtin(char ***to_free,
5853 const struct built_in_command *x,
5854 char **argv) NORETURN;
5855 static void exec_builtin(char ***to_free,
5856 const struct built_in_command *x,
5860 int rcode = x->b_function(argv);
5864 /* On NOMMU, we must never block!
5865 * Example: { sleep 99 | read line; } & echo Ok
5867 re_execute_shell(to_free,
5876 static void execvp_or_die(char **argv) NORETURN;
5877 static void execvp_or_die(char **argv)
5879 debug_printf_exec("execing '%s'\n", argv[0]);
5880 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5881 execvp(argv[0], argv);
5882 bb_perror_msg("can't execute '%s'", argv[0]);
5883 _exit(127); /* bash compat */
5886 #if ENABLE_HUSH_MODE_X
5887 static void dump_cmd_in_x_mode(char **argv)
5889 if (G_x_mode && argv) {
5890 /* We want to output the line in one write op */
5898 len += strlen(argv[n++]) + 1;
5904 p += sprintf(p, " %s", argv[n++]);
5912 # define dump_cmd_in_x_mode(argv) ((void)0)
5916 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
5917 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
5918 #define pseudo_exec(nommu_save, command, argv_expanded) \
5919 pseudo_exec(command, argv_expanded)
5922 /* Called after [v]fork() in run_pipe, or from builtin_exec.
5924 * Don't exit() here. If you don't exec, use _exit instead.
5925 * The at_exit handlers apparently confuse the calling process,
5926 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
5927 static void pseudo_exec_argv(nommu_save_t *nommu_save,
5928 char **argv, int assignment_cnt,
5929 char **argv_expanded) NORETURN;
5930 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
5931 char **argv, int assignment_cnt,
5932 char **argv_expanded)
5936 new_env = expand_assignments(argv, assignment_cnt);
5937 dump_cmd_in_x_mode(new_env);
5939 if (!argv[assignment_cnt]) {
5940 /* Case when we are here: ... | var=val | ...
5941 * (note that we do not exit early, i.e., do not optimize out
5942 * expand_assignments(): think about ... | var=`sleep 1` | ...
5944 free_strings(new_env);
5945 _exit(EXIT_SUCCESS);
5949 set_vars_and_save_old(new_env);
5950 free(new_env); /* optional */
5951 /* we can also destroy set_vars_and_save_old's return value,
5954 nommu_save->new_env = new_env;
5955 nommu_save->old_vars = set_vars_and_save_old(new_env);
5958 if (argv_expanded) {
5959 argv = argv_expanded;
5961 argv = expand_strvec_to_strvec(argv + assignment_cnt);
5963 nommu_save->argv = argv;
5966 dump_cmd_in_x_mode(argv);
5968 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
5969 if (strchr(argv[0], '/') != NULL)
5973 /* Check if the command matches any of the builtins.
5974 * Depending on context, this might be redundant. But it's
5975 * easier to waste a few CPU cycles than it is to figure out
5976 * if this is one of those cases.
5979 /* On NOMMU, it is more expensive to re-execute shell
5980 * just in order to run echo or test builtin.
5981 * It's better to skip it here and run corresponding
5982 * non-builtin later. */
5983 const struct built_in_command *x;
5984 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
5986 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
5989 #if ENABLE_HUSH_FUNCTIONS
5990 /* Check if the command matches any functions */
5992 const struct function *funcp = find_function(argv[0]);
5994 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
5999 #if ENABLE_FEATURE_SH_STANDALONE
6000 /* Check if the command matches any busybox applets */
6002 int a = find_applet_by_name(argv[0]);
6004 # if BB_MMU /* see above why on NOMMU it is not allowed */
6005 if (APPLET_IS_NOEXEC(a)) {
6006 debug_printf_exec("running applet '%s'\n", argv[0]);
6007 run_applet_no_and_exit(a, argv);
6010 /* Re-exec ourselves */
6011 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6012 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6013 execv(bb_busybox_exec_path, argv);
6014 /* If they called chroot or otherwise made the binary no longer
6015 * executable, fall through */
6020 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6023 execvp_or_die(argv);
6026 /* Called after [v]fork() in run_pipe
6028 static void pseudo_exec(nommu_save_t *nommu_save,
6029 struct command *command,
6030 char **argv_expanded) NORETURN;
6031 static void pseudo_exec(nommu_save_t *nommu_save,
6032 struct command *command,
6033 char **argv_expanded)
6035 if (command->argv) {
6036 pseudo_exec_argv(nommu_save, command->argv,
6037 command->assignment_cnt, argv_expanded);
6040 if (command->group) {
6041 /* Cases when we are here:
6044 * ... | ( list ) | ...
6045 * ... | { list } | ...
6049 debug_printf_exec("pseudo_exec: run_list\n");
6050 reset_traps_to_defaults();
6051 rcode = run_list(command->group);
6052 /* OK to leak memory by not calling free_pipe_list,
6053 * since this process is about to exit */
6056 re_execute_shell(&nommu_save->argv_from_re_execing,
6057 command->group_as_string,
6064 /* Case when we are here: ... | >file */
6065 debug_printf_exec("pseudo_exec'ed null command\n");
6066 _exit(EXIT_SUCCESS);
6070 static const char *get_cmdtext(struct pipe *pi)
6076 /* This is subtle. ->cmdtext is created only on first backgrounding.
6077 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6078 * On subsequent bg argv is trashed, but we won't use it */
6081 argv = pi->cmds[0].argv;
6082 if (!argv || !argv[0]) {
6083 pi->cmdtext = xzalloc(1);
6089 len += strlen(*argv) + 1;
6093 argv = pi->cmds[0].argv;
6095 len = strlen(*argv);
6096 memcpy(p, *argv, len);
6104 static void insert_bg_job(struct pipe *pi)
6106 struct pipe *job, **jobp;
6109 /* Linear search for the ID of the job to use */
6111 for (job = G.job_list; job; job = job->next)
6112 if (job->jobid >= pi->jobid)
6113 pi->jobid = job->jobid + 1;
6115 /* Add job to the list of running jobs */
6117 while ((job = *jobp) != NULL)
6119 job = *jobp = xmalloc(sizeof(*job));
6121 *job = *pi; /* physical copy */
6123 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6124 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6125 for (i = 0; i < pi->num_cmds; i++) {
6126 job->cmds[i].pid = pi->cmds[i].pid;
6127 /* all other fields are not used and stay zero */
6129 job->cmdtext = xstrdup(get_cmdtext(pi));
6131 if (G_interactive_fd)
6132 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6133 G.last_jobid = job->jobid;
6136 static void remove_bg_job(struct pipe *pi)
6138 struct pipe *prev_pipe;
6140 if (pi == G.job_list) {
6141 G.job_list = pi->next;
6143 prev_pipe = G.job_list;
6144 while (prev_pipe->next != pi)
6145 prev_pipe = prev_pipe->next;
6146 prev_pipe->next = pi->next;
6149 G.last_jobid = G.job_list->jobid;
6154 /* Remove a backgrounded job */
6155 static void delete_finished_bg_job(struct pipe *pi)
6162 /* Check to see if any processes have exited -- if they
6163 * have, figure out why and see if a job has completed */
6164 static int checkjobs(struct pipe *fg_pipe)
6174 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6176 attributes = WUNTRACED;
6177 if (fg_pipe == NULL)
6178 attributes |= WNOHANG;
6181 #if ENABLE_HUSH_FAST
6182 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6183 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6184 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6185 /* There was neither fork nor SIGCHLD since last waitpid */
6186 /* Avoid doing waitpid syscall if possible */
6187 if (!G.we_have_children) {
6191 if (fg_pipe == NULL) { /* is WNOHANG set? */
6192 /* We have children, but they did not exit
6193 * or stop yet (we saw no SIGCHLD) */
6196 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6200 /* Do we do this right?
6201 * bash-3.00# sleep 20 | false
6203 * [3]+ Stopped sleep 20 | false
6204 * bash-3.00# echo $?
6205 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6206 * [hush 1.14.0: yes we do it right]
6213 #if ENABLE_HUSH_FAST
6214 i = G.count_SIGCHLD;
6216 childpid = waitpid(-1, &status, attributes);
6217 if (childpid <= 0) {
6218 if (childpid && errno != ECHILD)
6219 bb_perror_msg("waitpid");
6220 #if ENABLE_HUSH_FAST
6221 else { /* Until next SIGCHLD, waitpid's are useless */
6222 G.we_have_children = (childpid == 0);
6223 G.handled_SIGCHLD = i;
6224 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6229 dead = WIFEXITED(status) || WIFSIGNALED(status);
6232 if (WIFSTOPPED(status))
6233 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6234 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6235 if (WIFSIGNALED(status))
6236 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6237 childpid, WTERMSIG(status), WEXITSTATUS(status));
6238 if (WIFEXITED(status))
6239 debug_printf_jobs("pid %d exited, exitcode %d\n",
6240 childpid, WEXITSTATUS(status));
6242 /* Were we asked to wait for fg pipe? */
6244 for (i = 0; i < fg_pipe->num_cmds; i++) {
6245 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6246 if (fg_pipe->cmds[i].pid != childpid)
6249 fg_pipe->cmds[i].pid = 0;
6250 fg_pipe->alive_cmds--;
6251 if (i == fg_pipe->num_cmds - 1) {
6252 /* last process gives overall exitstatus */
6253 rcode = WEXITSTATUS(status);
6254 /* bash prints killer signal's name for *last*
6255 * process in pipe (prints just newline for SIGINT).
6256 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6258 if (WIFSIGNALED(status)) {
6259 int sig = WTERMSIG(status);
6260 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
6261 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6262 * Maybe we need to use sig | 128? */
6265 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6268 fg_pipe->cmds[i].is_stopped = 1;
6269 fg_pipe->stopped_cmds++;
6271 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6272 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6273 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
6274 /* All processes in fg pipe have exited or stopped */
6275 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6276 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6277 * and "killall -STOP cat" */
6278 if (G_interactive_fd) {
6280 if (fg_pipe->alive_cmds)
6281 insert_bg_job(fg_pipe);
6285 if (!fg_pipe->alive_cmds)
6288 /* There are still running processes in the fg pipe */
6289 goto wait_more; /* do waitpid again */
6291 /* it wasnt fg_pipe, look for process in bg pipes */
6295 /* We asked to wait for bg or orphaned children */
6296 /* No need to remember exitcode in this case */
6297 for (pi = G.job_list; pi; pi = pi->next) {
6298 for (i = 0; i < pi->num_cmds; i++) {
6299 if (pi->cmds[i].pid == childpid)
6300 goto found_pi_and_prognum;
6303 /* Happens when shell is used as init process (init=/bin/sh) */
6304 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6305 continue; /* do waitpid again */
6307 found_pi_and_prognum:
6310 pi->cmds[i].pid = 0;
6312 if (!pi->alive_cmds) {
6313 if (G_interactive_fd)
6314 printf(JOB_STATUS_FORMAT, pi->jobid,
6315 "Done", pi->cmdtext);
6316 delete_finished_bg_job(pi);
6320 pi->cmds[i].is_stopped = 1;
6324 } /* while (waitpid succeeds)... */
6330 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6333 int rcode = checkjobs(fg_pipe);
6334 if (G_saved_tty_pgrp) {
6335 /* Job finished, move the shell to the foreground */
6336 p = getpgrp(); /* our process group id */
6337 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6338 tcsetpgrp(G_interactive_fd, p);
6344 /* Start all the jobs, but don't wait for anything to finish.
6347 * Return code is normally -1, when the caller has to wait for children
6348 * to finish to determine the exit status of the pipe. If the pipe
6349 * is a simple builtin command, however, the action is done by the
6350 * time run_pipe returns, and the exit code is provided as the
6353 * Returns -1 only if started some children. IOW: we have to
6354 * mask out retvals of builtins etc with 0xff!
6356 * The only case when we do not need to [v]fork is when the pipe
6357 * is single, non-backgrounded, non-subshell command. Examples:
6358 * cmd ; ... { list } ; ...
6359 * cmd && ... { list } && ...
6360 * cmd || ... { list } || ...
6361 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
6362 * or (if SH_STANDALONE) an applet, and we can run the { list }
6363 * with run_list. If it isn't one of these, we fork and exec cmd.
6365 * Cases when we must fork:
6366 * non-single: cmd | cmd
6367 * backgrounded: cmd & { list } &
6368 * subshell: ( list ) [&]
6370 #if !ENABLE_HUSH_MODE_X
6371 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, char argv_expanded) \
6372 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6374 static int redirect_and_varexp_helper(char ***new_env_p,
6375 struct variable **old_vars_p,
6376 struct command *command,
6378 char **argv_expanded)
6380 /* setup_redirects acts on file descriptors, not FILEs.
6381 * This is perfect for work that comes after exec().
6382 * Is it really safe for inline use? Experimentally,
6383 * things seem to work. */
6384 int rcode = setup_redirects(command, squirrel);
6386 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6387 *new_env_p = new_env;
6388 dump_cmd_in_x_mode(new_env);
6389 dump_cmd_in_x_mode(argv_expanded);
6391 *old_vars_p = set_vars_and_save_old(new_env);
6395 static NOINLINE int run_pipe(struct pipe *pi)
6397 static const char *const null_ptr = NULL;
6401 struct command *command;
6402 char **argv_expanded;
6404 /* it is not always needed, but we aim to smaller code */
6405 int squirrel[] = { -1, -1, -1 };
6408 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6411 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6412 * Result should be 3 lines: q w e, qwe, q w e
6414 G.ifs = get_local_var_value("IFS");
6418 IF_HUSH_JOB(pi->pgrp = -1;)
6419 pi->stopped_cmds = 0;
6420 command = &pi->cmds[0];
6421 argv_expanded = NULL;
6423 if (pi->num_cmds != 1
6424 || pi->followup == PIPE_BG
6425 || command->cmd_type == CMD_SUBSHELL
6432 debug_printf_exec(": group:%p argv:'%s'\n",
6433 command->group, command->argv ? command->argv[0] : "NONE");
6435 if (command->group) {
6436 #if ENABLE_HUSH_FUNCTIONS
6437 if (command->cmd_type == CMD_FUNCDEF) {
6438 /* "executing" func () { list } */
6439 struct function *funcp;
6441 funcp = new_function(command->argv[0]);
6442 /* funcp->name is already set to argv[0] */
6443 funcp->body = command->group;
6445 funcp->body_as_string = command->group_as_string;
6446 command->group_as_string = NULL;
6448 command->group = NULL;
6449 command->argv[0] = NULL;
6450 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6451 funcp->parent_cmd = command;
6452 command->child_func = funcp;
6454 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6456 return EXIT_SUCCESS;
6460 debug_printf("non-subshell group\n");
6461 rcode = 1; /* exitcode if redir failed */
6462 if (setup_redirects(command, squirrel) == 0) {
6463 debug_printf_exec(": run_list\n");
6464 rcode = run_list(command->group) & 0xff;
6466 restore_redirects(squirrel);
6467 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6469 debug_printf_exec("run_pipe: return %d\n", rcode);
6473 argv = command->argv ? command->argv : (char **) &null_ptr;
6475 const struct built_in_command *x;
6476 #if ENABLE_HUSH_FUNCTIONS
6477 const struct function *funcp;
6481 char **new_env = NULL;
6482 struct variable *old_vars = NULL;
6484 if (argv[command->assignment_cnt] == NULL) {
6485 /* Assignments, but no command */
6486 /* Ensure redirects take effect (that is, create files).
6487 * Try "a=t >file" */
6488 #if 0 /* A few cases in testsuite fail with this code. FIXME */
6489 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
6490 /* Set shell variables */
6494 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6495 /* Do we need to flag set_local_var() errors?
6496 * "assignment to readonly var" and "putenv error"
6501 /* Redirect error sets $? to 1. Otherwise,
6502 * if evaluating assignment value set $?, retain it.
6503 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6505 rcode = G.last_exitcode;
6506 /* Exit, _skipping_ variable restoring code: */
6507 goto clean_up_and_ret0;
6509 #else /* Older, bigger, but more correct code */
6511 rcode = setup_redirects(command, squirrel);
6512 restore_redirects(squirrel);
6513 /* Set shell variables */
6515 bb_putchar_stderr('+');
6517 char *p = expand_string_to_string(*argv);
6519 fprintf(stderr, " %s", p);
6520 debug_printf_exec("set shell var:'%s'->'%s'\n",
6522 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6523 /* Do we need to flag set_local_var() errors?
6524 * "assignment to readonly var" and "putenv error"
6529 bb_putchar_stderr('\n');
6530 /* Redirect error sets $? to 1. Otherwise,
6531 * if evaluating assignment value set $?, retain it.
6532 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6534 rcode = G.last_exitcode;
6535 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6537 debug_printf_exec("run_pipe: return %d\n", rcode);
6542 /* Expand the rest into (possibly) many strings each */
6544 #if ENABLE_HUSH_BASH_COMPAT
6545 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
6546 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
6550 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
6553 /* if someone gives us an empty string: `cmd with empty output` */
6554 if (!argv_expanded[0]) {
6555 free(argv_expanded);
6557 return G.last_exitcode;
6560 x = find_builtin(argv_expanded[0]);
6561 #if ENABLE_HUSH_FUNCTIONS
6564 funcp = find_function(argv_expanded[0]);
6568 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
6569 debug_printf("exec with redirects only\n");
6570 rcode = setup_redirects(command, NULL);
6571 goto clean_up_and_ret1;
6574 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6577 debug_printf_exec(": builtin '%s' '%s'...\n",
6578 x->b_cmd, argv_expanded[1]);
6579 rcode = x->b_function(argv_expanded) & 0xff;
6582 #if ENABLE_HUSH_FUNCTIONS
6584 # if ENABLE_HUSH_LOCAL
6585 struct variable **sv;
6586 sv = G.shadowed_vars_pp;
6587 G.shadowed_vars_pp = &old_vars;
6589 debug_printf_exec(": function '%s' '%s'...\n",
6590 funcp->name, argv_expanded[1]);
6591 rcode = run_function(funcp, argv_expanded) & 0xff;
6592 # if ENABLE_HUSH_LOCAL
6593 G.shadowed_vars_pp = sv;
6599 unset_vars(new_env);
6601 /* clean_up_and_ret0: */
6602 restore_redirects(squirrel);
6604 free(argv_expanded);
6605 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6607 debug_printf_exec("run_pipe return %d\n", rcode);
6611 if (ENABLE_FEATURE_SH_STANDALONE) {
6612 int n = find_applet_by_name(argv_expanded[0]);
6613 if (n >= 0 && APPLET_IS_NOFORK(n)) {
6614 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6616 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
6617 argv_expanded[0], argv_expanded[1]);
6618 rcode = run_nofork_applet(n, argv_expanded);
6620 goto clean_up_and_ret;
6623 /* It is neither builtin nor applet. We must fork. */
6627 /* NB: argv_expanded may already be created, and that
6628 * might include `cmd` runs! Do not rerun it! We *must*
6629 * use argv_expanded if it's non-NULL */
6631 /* Going to fork a child per each pipe member */
6636 while (cmd_no < pi->num_cmds) {
6637 struct fd_pair pipefds;
6639 volatile nommu_save_t nommu_save;
6640 nommu_save.new_env = NULL;
6641 nommu_save.old_vars = NULL;
6642 nommu_save.argv = NULL;
6643 nommu_save.argv_from_re_execing = NULL;
6645 command = &pi->cmds[cmd_no];
6647 if (command->argv) {
6648 debug_printf_exec(": pipe member '%s' '%s'...\n",
6649 command->argv[0], command->argv[1]);
6651 debug_printf_exec(": pipe member with no argv\n");
6654 /* pipes are inserted between pairs of commands */
6657 if (cmd_no < pi->num_cmds)
6658 xpiped_pair(pipefds);
6660 command->pid = BB_MMU ? fork() : vfork();
6661 if (!command->pid) { /* child */
6663 disable_restore_tty_pgrp_on_exit();
6664 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6666 /* Every child adds itself to new process group
6667 * with pgid == pid_of_first_child_in_pipe */
6668 if (G.run_list_level == 1 && G_interactive_fd) {
6671 if (pgrp < 0) /* true for 1st process only */
6673 if (setpgid(0, pgrp) == 0
6674 && pi->followup != PIPE_BG
6675 && G_saved_tty_pgrp /* we have ctty */
6677 /* We do it in *every* child, not just first,
6679 tcsetpgrp(G_interactive_fd, pgrp);
6683 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
6684 /* 1st cmd in backgrounded pipe
6685 * should have its stdin /dev/null'ed */
6687 if (open(bb_dev_null, O_RDONLY))
6688 xopen("/", O_RDONLY);
6690 xmove_fd(next_infd, 0);
6692 xmove_fd(pipefds.wr, 1);
6695 /* Like bash, explicit redirects override pipes,
6696 * and the pipe fd is available for dup'ing. */
6697 if (setup_redirects(command, NULL))
6700 /* Restore default handlers just prior to exec */
6701 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
6703 /* Stores to nommu_save list of env vars putenv'ed
6704 * (NOMMU, on MMU we don't need that) */
6705 /* cast away volatility... */
6706 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
6707 /* pseudo_exec() does not return */
6710 /* parent or error */
6711 #if ENABLE_HUSH_FAST
6713 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6715 enable_restore_tty_pgrp_on_exit();
6717 /* Clean up after vforked child */
6718 free(nommu_save.argv);
6719 free(nommu_save.argv_from_re_execing);
6720 unset_vars(nommu_save.new_env);
6721 add_vars(nommu_save.old_vars);
6723 free(argv_expanded);
6724 argv_expanded = NULL;
6725 if (command->pid < 0) { /* [v]fork failed */
6726 /* Clearly indicate, was it fork or vfork */
6727 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
6731 /* Second and next children need to know pid of first one */
6733 pi->pgrp = command->pid;
6739 if (cmd_no < pi->num_cmds)
6741 /* Pass read (output) pipe end to next iteration */
6742 next_infd = pipefds.rd;
6745 if (!pi->alive_cmds) {
6747 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
6752 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
6756 #ifndef debug_print_tree
6757 static void debug_print_tree(struct pipe *pi, int lvl)
6759 static const char *const PIPE[] = {
6765 static const char *RES[] = {
6766 [RES_NONE ] = "NONE" ,
6769 [RES_THEN ] = "THEN" ,
6770 [RES_ELIF ] = "ELIF" ,
6771 [RES_ELSE ] = "ELSE" ,
6774 # if ENABLE_HUSH_LOOPS
6775 [RES_FOR ] = "FOR" ,
6776 [RES_WHILE] = "WHILE",
6777 [RES_UNTIL] = "UNTIL",
6779 [RES_DONE ] = "DONE" ,
6781 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
6784 # if ENABLE_HUSH_CASE
6785 [RES_CASE ] = "CASE" ,
6786 [RES_CASE_IN ] = "CASE_IN" ,
6787 [RES_MATCH] = "MATCH",
6788 [RES_CASE_BODY] = "CASE_BODY",
6789 [RES_ESAC ] = "ESAC" ,
6791 [RES_XXXX ] = "XXXX" ,
6792 [RES_SNTX ] = "SNTX" ,
6794 static const char *const CMDTYPE[] = {
6798 # if ENABLE_HUSH_FUNCTIONS
6807 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
6808 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
6810 while (prn < pi->num_cmds) {
6811 struct command *command = &pi->cmds[prn];
6812 char **argv = command->argv;
6814 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
6816 command->assignment_cnt);
6817 if (command->group) {
6818 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
6819 CMDTYPE[command->cmd_type],
6822 , " group_as_string:", command->group_as_string
6827 debug_print_tree(command->group, lvl+1);
6831 if (argv) while (*argv) {
6832 fprintf(stderr, " '%s'", *argv);
6835 fprintf(stderr, "\n");
6842 #endif /* debug_print_tree */
6844 /* NB: called by pseudo_exec, and therefore must not modify any
6845 * global data until exec/_exit (we can be a child after vfork!) */
6846 static int run_list(struct pipe *pi)
6848 #if ENABLE_HUSH_CASE
6849 char *case_word = NULL;
6851 #if ENABLE_HUSH_LOOPS
6852 struct pipe *loop_top = NULL;
6853 char **for_lcur = NULL;
6854 char **for_list = NULL;
6856 smallint last_followup;
6858 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
6859 smalluint cond_code = 0;
6861 enum { cond_code = 0 };
6864 smallint rword; /* RES_foo */
6865 smallint last_rword; /* ditto */
6868 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
6871 #if ENABLE_HUSH_LOOPS
6872 /* Check syntax for "for" */
6873 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
6874 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
6876 /* current word is FOR or IN (BOLD in comments below) */
6877 if (cpipe->next == NULL) {
6878 syntax_error("malformed for");
6880 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
6883 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
6884 if (cpipe->next->res_word == RES_DO)
6886 /* next word is not "do". It must be "in" then ("FOR v in ...") */
6887 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
6888 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
6890 syntax_error("malformed for");
6892 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
6898 /* Past this point, all code paths should jump to ret: label
6899 * in order to return, no direct "return" statements please.
6900 * This helps to ensure that no memory is leaked. */
6908 last_rword = RES_XXXX;
6910 last_followup = PIPE_SEQ;
6911 rcode = G.last_exitcode;
6913 /* Go through list of pipes, (maybe) executing them. */
6914 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
6918 IF_HAS_KEYWORDS(rword = pi->res_word;)
6919 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
6920 rword, cond_code, last_rword);
6921 #if ENABLE_HUSH_LOOPS
6922 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
6923 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
6925 /* start of a loop: remember where loop starts */
6930 /* Still in the same "if...", "then..." or "do..." branch? */
6931 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
6932 if ((rcode == 0 && last_followup == PIPE_OR)
6933 || (rcode != 0 && last_followup == PIPE_AND)
6935 /* It is "<true> || CMD" or "<false> && CMD"
6936 * and we should not execute CMD */
6937 debug_printf_exec("skipped cmd because of || or &&\n");
6938 last_followup = pi->followup;
6942 last_followup = pi->followup;
6943 IF_HAS_KEYWORDS(last_rword = rword;)
6946 if (rword == RES_THEN) {
6947 /* if false; then ... fi has exitcode 0! */
6948 G.last_exitcode = rcode = EXIT_SUCCESS;
6949 /* "if <false> THEN cmd": skip cmd */
6953 if (rword == RES_ELSE || rword == RES_ELIF) {
6954 /* "if <true> then ... ELSE/ELIF cmd":
6955 * skip cmd and all following ones */
6960 #if ENABLE_HUSH_LOOPS
6961 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
6963 /* first loop through for */
6965 static const char encoded_dollar_at[] ALIGN1 = {
6966 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
6967 }; /* encoded representation of "$@" */
6968 static const char *const encoded_dollar_at_argv[] = {
6969 encoded_dollar_at, NULL
6970 }; /* argv list with one element: "$@" */
6973 vals = (char**)encoded_dollar_at_argv;
6974 if (pi->next->res_word == RES_IN) {
6975 /* if no variable values after "in" we skip "for" */
6976 if (!pi->next->cmds[0].argv) {
6977 G.last_exitcode = rcode = EXIT_SUCCESS;
6978 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
6981 vals = pi->next->cmds[0].argv;
6982 } /* else: "for var; do..." -> assume "$@" list */
6983 /* create list of variable values */
6984 debug_print_strings("for_list made from", vals);
6985 for_list = expand_strvec_to_strvec(vals);
6986 for_lcur = for_list;
6987 debug_print_strings("for_list", for_list);
6990 /* "for" loop is over, clean up */
6996 /* Insert next value from for_lcur */
6997 /* note: *for_lcur already has quotes removed, $var expanded, etc */
6998 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7001 if (rword == RES_IN) {
7002 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7004 if (rword == RES_DONE) {
7005 continue; /* "done" has no cmds too */
7008 #if ENABLE_HUSH_CASE
7009 if (rword == RES_CASE) {
7010 case_word = expand_strvec_to_string(pi->cmds->argv);
7013 if (rword == RES_MATCH) {
7016 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7018 /* all prev words didn't match, does this one match? */
7019 argv = pi->cmds->argv;
7021 char *pattern = expand_string_to_string(*argv);
7022 /* TODO: which FNM_xxx flags to use? */
7023 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7025 if (cond_code == 0) { /* match! we will execute this branch */
7026 free(case_word); /* make future "word)" stop */
7034 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7036 continue; /* not matched yet, skip this pipe */
7039 /* Just pressing <enter> in shell should check for jobs.
7040 * OTOH, in non-interactive shell this is useless
7041 * and only leads to extra job checks */
7042 if (pi->num_cmds == 0) {
7043 if (G_interactive_fd)
7044 goto check_jobs_and_continue;
7048 /* After analyzing all keywords and conditions, we decided
7049 * to execute this pipe. NB: have to do checkjobs(NULL)
7050 * after run_pipe to collect any background children,
7051 * even if list execution is to be stopped. */
7052 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7055 #if ENABLE_HUSH_LOOPS
7056 G.flag_break_continue = 0;
7058 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7060 /* We ran a builtin, function, or group.
7061 * rcode is already known
7062 * and we don't need to wait for anything. */
7063 G.last_exitcode = rcode;
7064 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7065 check_and_run_traps(0);
7066 #if ENABLE_HUSH_LOOPS
7067 /* Was it "break" or "continue"? */
7068 if (G.flag_break_continue) {
7069 smallint fbc = G.flag_break_continue;
7070 /* We might fall into outer *loop*,
7071 * don't want to break it too */
7073 G.depth_break_continue--;
7074 if (G.depth_break_continue == 0)
7075 G.flag_break_continue = 0;
7076 /* else: e.g. "continue 2" should *break* once, *then* continue */
7077 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7078 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
7079 goto check_jobs_and_break;
7080 /* "continue": simulate end of loop */
7085 #if ENABLE_HUSH_FUNCTIONS
7086 if (G.flag_return_in_progress == 1) {
7087 /* same as "goto check_jobs_and_break" */
7092 } else if (pi->followup == PIPE_BG) {
7093 /* What does bash do with attempts to background builtins? */
7094 /* even bash 3.2 doesn't do that well with nested bg:
7095 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7096 * I'm NOT treating inner &'s as jobs */
7097 check_and_run_traps(0);
7099 if (G.run_list_level == 1)
7102 /* Last command's pid goes to $! */
7103 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7104 G.last_exitcode = rcode = EXIT_SUCCESS;
7105 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7108 if (G.run_list_level == 1 && G_interactive_fd) {
7109 /* Waits for completion, then fg's main shell */
7110 rcode = checkjobs_and_fg_shell(pi);
7111 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7112 check_and_run_traps(0);
7115 { /* This one just waits for completion */
7116 rcode = checkjobs(pi);
7117 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7118 check_and_run_traps(0);
7120 G.last_exitcode = rcode;
7124 /* Analyze how result affects subsequent commands */
7126 if (rword == RES_IF || rword == RES_ELIF)
7129 #if ENABLE_HUSH_LOOPS
7130 /* Beware of "while false; true; do ..."! */
7131 if (pi->next && pi->next->res_word == RES_DO) {
7132 if (rword == RES_WHILE) {
7134 /* "while false; do...done" - exitcode 0 */
7135 G.last_exitcode = rcode = EXIT_SUCCESS;
7136 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7137 goto check_jobs_and_break;
7140 if (rword == RES_UNTIL) {
7142 debug_printf_exec(": until expr is true: breaking\n");
7143 check_jobs_and_break:
7151 check_jobs_and_continue:
7158 #if ENABLE_HUSH_LOOPS
7163 #if ENABLE_HUSH_CASE
7167 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7171 /* Select which version we will use */
7172 static int run_and_free_list(struct pipe *pi)
7175 debug_printf_exec("run_and_free_list entered\n");
7177 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7178 rcode = run_list(pi);
7180 /* free_pipe_list has the side effect of clearing memory.
7181 * In the long run that function can be merged with run_list,
7182 * but doing that now would hobble the debugging effort. */
7184 debug_printf_exec("run_and_free_list return %d\n", rcode);
7189 /* Called a few times only (or even once if "sh -c") */
7190 static void init_sigmasks(void)
7194 sigset_t old_blocked_set;
7196 if (!G.inherited_set_is_saved) {
7197 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
7198 G.inherited_set = G.blocked_set;
7200 old_blocked_set = G.blocked_set;
7202 mask = (1 << SIGQUIT);
7203 if (G_interactive_fd) {
7204 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
7205 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7206 mask |= SPECIAL_JOB_SIGS;
7208 G.non_DFL_mask = mask;
7213 sigaddset(&G.blocked_set, sig);
7217 sigdelset(&G.blocked_set, SIGCHLD);
7219 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
7220 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7222 /* POSIX allows shell to re-enable SIGCHLD
7223 * even if it was SIG_IGN on entry */
7224 #if ENABLE_HUSH_FAST
7225 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7226 if (!G.inherited_set_is_saved)
7227 signal(SIGCHLD, SIGCHLD_handler);
7229 if (!G.inherited_set_is_saved)
7230 signal(SIGCHLD, SIG_DFL);
7233 G.inherited_set_is_saved = 1;
7238 static void maybe_set_to_sigexit(int sig)
7240 void (*handler)(int);
7241 /* non_DFL_mask'ed signals are, well, masked,
7242 * no need to set handler for them.
7244 if (!((G.non_DFL_mask >> sig) & 1)) {
7245 handler = signal(sig, sigexit);
7246 if (handler == SIG_IGN) /* oops... restore back to IGN! */
7247 signal(sig, handler);
7250 /* Set handlers to restore tty pgrp and exit */
7251 static void set_fatal_handlers(void)
7253 /* We _must_ restore tty pgrp on fatal signals */
7255 maybe_set_to_sigexit(SIGILL );
7256 maybe_set_to_sigexit(SIGFPE );
7257 maybe_set_to_sigexit(SIGBUS );
7258 maybe_set_to_sigexit(SIGSEGV);
7259 maybe_set_to_sigexit(SIGTRAP);
7260 } /* else: hush is perfect. what SEGV? */
7261 maybe_set_to_sigexit(SIGABRT);
7262 /* bash 3.2 seems to handle these just like 'fatal' ones */
7263 maybe_set_to_sigexit(SIGPIPE);
7264 maybe_set_to_sigexit(SIGALRM);
7265 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
7266 * if we aren't interactive... but in this case
7267 * we never want to restore pgrp on exit, and this fn is not called */
7268 /*maybe_set_to_sigexit(SIGHUP );*/
7269 /*maybe_set_to_sigexit(SIGTERM);*/
7270 /*maybe_set_to_sigexit(SIGINT );*/
7274 static int set_mode(const char cstate, const char mode)
7276 int state = (cstate == '-' ? 1 : 0);
7278 case 'n': G.n_mode = state; break;
7279 case 'x': IF_HUSH_MODE_X(G_x_mode = state;) break;
7280 default: return EXIT_FAILURE;
7282 return EXIT_SUCCESS;
7285 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7286 int hush_main(int argc, char **argv)
7289 unsigned builtin_argc;
7291 struct variable *cur_var;
7294 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
7295 G.last_exitcode = EXIT_SUCCESS;
7297 G.argv0_for_re_execing = argv[0];
7299 /* Deal with HUSH_VERSION */
7300 G.shell_ver.flg_export = 1;
7301 G.shell_ver.flg_read_only = 1;
7302 /* Code which handles ${var/P/R} needs writable values for all variables,
7303 * therefore we xstrdup: */
7304 G.shell_ver.varstr = xstrdup(hush_version_str),
7305 G.top_var = &G.shell_ver;
7306 /* Create shell local variables from the values
7307 * currently living in the environment */
7308 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7309 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7310 cur_var = G.top_var;
7313 char *value = strchr(*e, '=');
7314 if (value) { /* paranoia */
7315 cur_var->next = xzalloc(sizeof(*cur_var));
7316 cur_var = cur_var->next;
7317 cur_var->varstr = *e;
7318 cur_var->max_len = strlen(*e);
7319 cur_var->flg_export = 1;
7323 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7324 debug_printf_env("putenv '%s'\n", G.shell_ver.varstr);
7325 putenv(G.shell_ver.varstr);
7328 set_pwd_var(/*exp:*/ 1);
7329 /* bash also exports SHLVL and _,
7330 * and sets (but doesn't export) the following variables:
7332 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7333 * BASH_VERSION='3.2.0(1)-release'
7335 * MACHTYPE=i386-pc-linux-gnu
7337 * HOSTNAME=<xxxxxxxxxx>
7338 * PPID=<NNNNN> - we also do it elsewhere
7349 * PIPESTATUS=([0]="0")
7350 * HISTFILE=/<xxx>/.bash_history
7354 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7356 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7366 #if ENABLE_FEATURE_EDITING
7367 G.line_input_state = new_line_input_t(FOR_SHELL);
7369 G.global_argc = argc;
7370 G.global_argv = argv;
7371 /* Initialize some more globals to non-zero values */
7372 cmdedit_update_prompt();
7374 if (setjmp(die_jmp)) {
7375 /* xfunc has failed! die die die */
7376 /* no EXIT traps, this is an escape hatch! */
7378 hush_exit(xfunc_error_retval);
7381 /* Shell is non-interactive at first. We need to call
7382 * init_sigmasks() if we are going to execute "sh <script>",
7383 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7384 * If we later decide that we are interactive, we run init_sigmasks()
7385 * in order to intercept (more) signals.
7389 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7392 opt = getopt(argc, argv, "+c:xins"
7395 # if ENABLE_HUSH_FUNCTIONS
7405 * sh ... -c 'script'
7406 * sh ... -c 'script' ARG0 [ARG1...]
7407 * On NOMMU, if builtin_argc != 0,
7408 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7409 * "" needs to be replaced with NULL
7410 * and BARGV vector fed to builtin function.
7411 * Note: the form without ARG0 never happens:
7412 * sh ... -c 'builtin' BARGV... ""
7415 G.root_pid = getpid();
7416 G.root_ppid = getppid();
7418 G.global_argv = argv + optind;
7419 G.global_argc = argc - optind;
7421 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7422 const struct built_in_command *x;
7425 x = find_builtin(optarg);
7426 if (x) { /* paranoia */
7427 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7428 G.global_argv += builtin_argc;
7429 G.global_argv[-1] = NULL; /* replace "" */
7430 G.last_exitcode = x->b_function(argv + optind - 1);
7434 if (!G.global_argv[0]) {
7435 /* -c 'script' (no params): prevent empty $0 */
7436 G.global_argv--; /* points to argv[i] of 'script' */
7437 G.global_argv[0] = argv[0];
7439 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7441 parse_and_run_string(optarg);
7444 /* Well, we cannot just declare interactiveness,
7445 * we have to have some stuff (ctty, etc) */
7446 /* G_interactive_fd++; */
7449 /* "-s" means "read from stdin", but this is how we always
7450 * operate, so simply do nothing here. */
7453 case '<': /* "big heredoc" support */
7454 full_write1_str(optarg);
7457 unsigned long long empty_trap_mask;
7459 G.root_pid = bb_strtou(optarg, &optarg, 16);
7461 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7463 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7465 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7467 builtin_argc = bb_strtou(optarg, &optarg, 16);
7469 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7470 if (empty_trap_mask != 0) {
7473 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7474 for (sig = 1; sig < NSIG; sig++) {
7475 if (empty_trap_mask & (1LL << sig)) {
7476 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7477 sigaddset(&G.blocked_set, sig);
7480 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7482 # if ENABLE_HUSH_LOOPS
7484 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7490 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7492 # if ENABLE_HUSH_FUNCTIONS
7494 struct function *funcp = new_function(optarg);
7495 /* funcp->name is already set to optarg */
7496 /* funcp->body is set to NULL. It's a special case. */
7497 funcp->body_as_string = argv[optind];
7505 if (set_mode('-', opt) == 0) /* no error */
7509 fprintf(stderr, "Usage: sh [FILE]...\n"
7510 " or: sh -c command [args]...\n\n");
7516 } /* option parsing loop */
7519 G.root_pid = getpid();
7520 G.root_ppid = getppid();
7523 /* If we are login shell... */
7524 if (argv[0] && argv[0][0] == '-') {
7526 debug_printf("sourcing /etc/profile\n");
7527 input = fopen_for_read("/etc/profile");
7528 if (input != NULL) {
7529 close_on_exec_on(fileno(input));
7531 parse_and_run_file(input);
7534 /* bash: after sourcing /etc/profile,
7535 * tries to source (in the given order):
7536 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7537 * stopping on first found. --noprofile turns this off.
7538 * bash also sources ~/.bash_logout on exit.
7539 * If called as sh, skips .bash_XXX files.
7546 * "bash <script>" (which is never interactive (unless -i?))
7547 * sources $BASH_ENV here (without scanning $PATH).
7548 * If called as sh, does the same but with $ENV.
7550 debug_printf("running script '%s'\n", argv[optind]);
7551 G.global_argv = argv + optind;
7552 G.global_argc = argc - optind;
7553 input = xfopen_for_read(argv[optind]);
7554 close_on_exec_on(fileno(input));
7556 parse_and_run_file(input);
7557 #if ENABLE_FEATURE_CLEAN_UP
7563 /* Up to here, shell was non-interactive. Now it may become one.
7564 * NB: don't forget to (re)run init_sigmasks() as needed.
7567 /* A shell is interactive if the '-i' flag was given,
7568 * or if all of the following conditions are met:
7570 * no arguments remaining or the -s flag given
7571 * standard input is a terminal
7572 * standard output is a terminal
7573 * Refer to Posix.2, the description of the 'sh' utility.
7576 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7577 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7578 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7579 if (G_saved_tty_pgrp < 0)
7580 G_saved_tty_pgrp = 0;
7582 /* try to dup stdin to high fd#, >= 255 */
7583 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7584 if (G_interactive_fd < 0) {
7585 /* try to dup to any fd */
7586 G_interactive_fd = dup(STDIN_FILENO);
7587 if (G_interactive_fd < 0) {
7589 G_interactive_fd = 0;
7590 G_saved_tty_pgrp = 0;
7593 // TODO: track & disallow any attempts of user
7594 // to (inadvertently) close/redirect G_interactive_fd
7596 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7597 if (G_interactive_fd) {
7598 close_on_exec_on(G_interactive_fd);
7600 if (G_saved_tty_pgrp) {
7601 /* If we were run as 'hush &', sleep until we are
7602 * in the foreground (tty pgrp == our pgrp).
7603 * If we get started under a job aware app (like bash),
7604 * make sure we are now in charge so we don't fight over
7605 * who gets the foreground */
7607 pid_t shell_pgrp = getpgrp();
7608 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7609 if (G_saved_tty_pgrp == shell_pgrp)
7611 /* send TTIN to ourself (should stop us) */
7612 kill(- shell_pgrp, SIGTTIN);
7616 /* Block some signals */
7619 if (G_saved_tty_pgrp) {
7620 /* Set other signals to restore saved_tty_pgrp */
7621 set_fatal_handlers();
7622 /* Put ourselves in our own process group
7623 * (bash, too, does this only if ctty is available) */
7624 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7625 /* Grab control of the terminal */
7626 tcsetpgrp(G_interactive_fd, getpid());
7628 /* -1 is special - makes xfuncs longjmp, not exit
7629 * (we reset die_sleep = 0 whereever we [v]fork) */
7630 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7634 #elif ENABLE_HUSH_INTERACTIVE
7635 /* No job control compiled in, only prompt/line editing */
7636 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7637 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7638 if (G_interactive_fd < 0) {
7639 /* try to dup to any fd */
7640 G_interactive_fd = dup(STDIN_FILENO);
7641 if (G_interactive_fd < 0)
7643 G_interactive_fd = 0;
7646 if (G_interactive_fd) {
7647 close_on_exec_on(G_interactive_fd);
7651 /* We have interactiveness code disabled */
7655 * if interactive but not a login shell, sources ~/.bashrc
7656 * (--norc turns this off, --rcfile <file> overrides)
7659 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7660 /* note: ash and hush share this string */
7661 printf("\n\n%s %s\n"
7662 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7665 "hush - the humble shell"
7669 parse_and_run_file(stdin);
7672 #if ENABLE_FEATURE_CLEAN_UP
7673 if (G.cwd != bb_msg_unknown)
7675 cur_var = G.top_var->next;
7677 struct variable *tmp = cur_var;
7678 if (!cur_var->max_len)
7679 free(cur_var->varstr);
7680 cur_var = cur_var->next;
7684 hush_exit(G.last_exitcode);
7689 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7690 int msh_main(int argc, char **argv)
7692 //bb_error_msg("msh is deprecated, please use hush instead");
7693 return hush_main(argc, argv);
7701 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7706 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7713 return applet_main_func(argc, argv - argc);
7716 static int FAST_FUNC builtin_test(char **argv)
7718 return run_applet_main(argv, test_main);
7721 static int FAST_FUNC builtin_echo(char **argv)
7723 return run_applet_main(argv, echo_main);
7727 static int FAST_FUNC builtin_printf(char **argv)
7729 return run_applet_main(argv, printf_main);
7733 static char **skip_dash_dash(char **argv)
7736 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7741 static int FAST_FUNC builtin_eval(char **argv)
7743 int rcode = EXIT_SUCCESS;
7745 argv = skip_dash_dash(argv);
7747 char *str = expand_strvec_to_string(argv);
7749 * eval "echo Hi; done" ("done" is syntax error):
7750 * "echo Hi" will not execute too.
7752 parse_and_run_string(str);
7754 rcode = G.last_exitcode;
7759 static int FAST_FUNC builtin_cd(char **argv)
7763 argv = skip_dash_dash(argv);
7765 if (newdir == NULL) {
7766 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7767 * bash says "bash: cd: HOME not set" and does nothing
7770 const char *home = get_local_var_value("HOME");
7771 newdir = home ? home : "/";
7773 if (chdir(newdir)) {
7774 /* Mimic bash message exactly */
7775 bb_perror_msg("cd: %s", newdir);
7776 return EXIT_FAILURE;
7778 /* Read current dir (get_cwd(1) is inside) and set PWD.
7779 * Note: do not enforce exporting. If PWD was unset or unexported,
7780 * set it again, but do not export. bash does the same.
7782 set_pwd_var(/*exp:*/ 0);
7783 return EXIT_SUCCESS;
7786 static int FAST_FUNC builtin_exec(char **argv)
7788 argv = skip_dash_dash(argv);
7789 if (argv[0] == NULL)
7790 return EXIT_SUCCESS; /* bash does this */
7792 /* Careful: we can end up here after [v]fork. Do not restore
7793 * tty pgrp then, only top-level shell process does that */
7794 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7795 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7797 /* TODO: if exec fails, bash does NOT exit! We do.
7798 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7799 * and tcsetpgrp, and this is inherently racy.
7801 execvp_or_die(argv);
7804 static int FAST_FUNC builtin_exit(char **argv)
7806 debug_printf_exec("%s()\n", __func__);
7808 /* interactive bash:
7809 * # trap "echo EEE" EXIT
7812 * There are stopped jobs.
7813 * (if there are _stopped_ jobs, running ones don't count)
7816 # EEE (then bash exits)
7818 * we can use G.exiting = -1 as indicator "last cmd was exit"
7821 /* note: EXIT trap is run by hush_exit */
7822 argv = skip_dash_dash(argv);
7823 if (argv[0] == NULL)
7824 hush_exit(G.last_exitcode);
7825 /* mimic bash: exit 123abc == exit 255 + error msg */
7826 xfunc_error_retval = 255;
7827 /* bash: exit -2 == exit 254, no error msg */
7828 hush_exit(xatoi(argv[0]) & 0xff);
7831 static void print_escaped(const char *s)
7836 const char *p = strchrnul(s, '\'');
7837 /* print 'xxxx', possibly just '' */
7838 printf("'%.*s'", (int)(p - s), s);
7843 /* s points to '; print "'''...'''" */
7845 do putchar('\''); while (*++s == '\'');
7850 #if !ENABLE_HUSH_LOCAL
7851 #define helper_export_local(argv, exp, lvl) \
7852 helper_export_local(argv, exp)
7854 static void helper_export_local(char **argv, int exp, int lvl)
7858 char *name_end = strchrnul(name, '=');
7860 /* So far we do not check that name is valid (TODO?) */
7862 if (*name_end == '\0') {
7863 struct variable *var, **vpp;
7865 vpp = get_ptr_to_local_var(name, name_end - name);
7866 var = vpp ? *vpp : NULL;
7868 if (exp == -1) { /* unexporting? */
7869 /* export -n NAME (without =VALUE) */
7871 var->flg_export = 0;
7872 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7874 } /* else: export -n NOT_EXISTING_VAR: no-op */
7877 if (exp == 1) { /* exporting? */
7878 /* export NAME (without =VALUE) */
7880 var->flg_export = 1;
7881 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7882 putenv(var->varstr);
7886 /* Exporting non-existing variable.
7887 * bash does not put it in environment,
7888 * but remembers that it is exported,
7889 * and does put it in env when it is set later.
7890 * We just set it to "" and export. */
7891 /* Or, it's "local NAME" (without =VALUE).
7892 * bash sets the value to "". */
7893 name = xasprintf("%s=", name);
7895 /* (Un)exporting/making local NAME=VALUE */
7896 name = xstrdup(name);
7898 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7902 static int FAST_FUNC builtin_export(char **argv)
7904 unsigned opt_unexport;
7906 #if ENABLE_HUSH_EXPORT_N
7907 /* "!": do not abort on errors */
7908 opt_unexport = getopt32(argv, "!n");
7909 if (opt_unexport == (uint32_t)-1)
7910 return EXIT_FAILURE;
7917 if (argv[0] == NULL) {
7924 /* ash emits: export VAR='VAL'
7925 * bash: declare -x VAR="VAL"
7926 * we follow ash example */
7927 const char *s = *e++;
7928 const char *p = strchr(s, '=');
7930 if (!p) /* wtf? take next variable */
7933 printf("export %.*s", (int)(p - s) + 1, s);
7934 print_escaped(p + 1);
7938 /*fflush_all(); - done after each builtin anyway */
7940 return EXIT_SUCCESS;
7943 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7945 return EXIT_SUCCESS;
7948 #if ENABLE_HUSH_LOCAL
7949 static int FAST_FUNC builtin_local(char **argv)
7951 if (G.func_nest_level == 0) {
7952 bb_error_msg("%s: not in a function", argv[0]);
7953 return EXIT_FAILURE; /* bash compat */
7955 helper_export_local(argv, 0, G.func_nest_level);
7956 return EXIT_SUCCESS;
7960 static int FAST_FUNC builtin_trap(char **argv)
7966 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7971 /* No args: print all trapped */
7972 for (i = 0; i < NSIG; ++i) {
7975 print_escaped(G.traps[i]);
7976 /* note: bash adds "SIG", but only if invoked
7977 * as "bash". If called as "sh", or if set -o posix,
7978 * then it prints short signal names.
7979 * We are printing short names: */
7980 printf(" %s\n", get_signame(i));
7983 /*fflush_all(); - done after each builtin anyway */
7984 return EXIT_SUCCESS;
7988 /* If first arg is a number: reset all specified signals */
7989 sig = bb_strtou(*argv, NULL, 10);
7995 sig = get_signum(*argv++);
7996 if (sig < 0 || sig >= NSIG) {
7998 /* Mimic bash message exactly */
7999 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8004 G.traps[sig] = xstrdup(new_cmd);
8006 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8007 get_signame(sig), sig, G.traps[sig]);
8009 /* There is no signal for 0 (EXIT) */
8014 sigaddset(&G.blocked_set, sig);
8016 /* There was a trap handler, we are removing it
8017 * (if sig has non-DFL handling,
8018 * we don't need to do anything) */
8019 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
8021 sigdelset(&G.blocked_set, sig);
8024 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8028 if (!argv[1]) { /* no second arg */
8029 bb_error_msg("trap: invalid arguments");
8030 return EXIT_FAILURE;
8033 /* First arg is "-": reset all specified to default */
8034 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8035 /* Everything else: set arg as signal handler
8036 * (includes "" case, which ignores signal) */
8037 if (argv[0][0] == '-') {
8038 if (argv[0][1] == '\0') { /* "-" */
8039 /* new_cmd remains NULL: "reset these sigs" */
8042 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8045 /* else: "-something", no special meaning */
8050 goto process_sig_list;
8053 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8054 static int FAST_FUNC builtin_type(char **argv)
8056 int ret = EXIT_SUCCESS;
8062 if (0) {} /* make conditional compile easier below */
8063 /*else if (find_alias(*argv))
8064 type = "an alias";*/
8065 #if ENABLE_HUSH_FUNCTIONS
8066 else if (find_function(*argv))
8067 type = "a function";
8069 else if (find_builtin(*argv))
8070 type = "a shell builtin";
8071 else if ((path = find_in_path(*argv)) != NULL)
8074 bb_error_msg("type: %s: not found", *argv);
8079 printf("%s is %s\n", *argv, type);
8087 /* built-in 'fg' and 'bg' handler */
8088 static int FAST_FUNC builtin_fg_bg(char **argv)
8093 if (!G_interactive_fd)
8094 return EXIT_FAILURE;
8096 /* If they gave us no args, assume they want the last backgrounded task */
8098 for (pi = G.job_list; pi; pi = pi->next) {
8099 if (pi->jobid == G.last_jobid) {
8103 bb_error_msg("%s: no current job", argv[0]);
8104 return EXIT_FAILURE;
8106 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8107 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8108 return EXIT_FAILURE;
8110 for (pi = G.job_list; pi; pi = pi->next) {
8111 if (pi->jobid == jobnum) {
8115 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8116 return EXIT_FAILURE;
8118 /* TODO: bash prints a string representation
8119 * of job being foregrounded (like "sleep 1 | cat") */
8120 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8121 /* Put the job into the foreground. */
8122 tcsetpgrp(G_interactive_fd, pi->pgrp);
8125 /* Restart the processes in the job */
8126 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8127 for (i = 0; i < pi->num_cmds; i++) {
8128 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8129 pi->cmds[i].is_stopped = 0;
8131 pi->stopped_cmds = 0;
8133 i = kill(- pi->pgrp, SIGCONT);
8135 if (errno == ESRCH) {
8136 delete_finished_bg_job(pi);
8137 return EXIT_SUCCESS;
8139 bb_perror_msg("kill (SIGCONT)");
8142 if (argv[0][0] == 'f') {
8144 return checkjobs_and_fg_shell(pi);
8146 return EXIT_SUCCESS;
8150 #if ENABLE_HUSH_HELP
8151 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8153 const struct built_in_command *x;
8156 "Built-in commands:\n"
8157 "------------------\n");
8158 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8160 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8163 return EXIT_SUCCESS;
8168 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8171 const char *status_string;
8173 for (job = G.job_list; job; job = job->next) {
8174 if (job->alive_cmds == job->stopped_cmds)
8175 status_string = "Stopped";
8177 status_string = "Running";
8179 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8181 return EXIT_SUCCESS;
8186 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8191 # ifdef M_TRIM_THRESHOLD
8192 /* Optional. Reduces probability of false positives */
8195 /* Crude attempt to find where "free memory" starts,
8196 * sans fragmentation. */
8198 l = (unsigned long)p;
8201 if (l < (unsigned long)p) l = (unsigned long)p;
8204 if (!G.memleak_value)
8205 G.memleak_value = l;
8207 l -= G.memleak_value;
8214 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8219 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8222 return EXIT_SUCCESS;
8225 static int FAST_FUNC builtin_read(char **argv)
8234 /* "!": do not abort on errors.
8235 * Option string must start with "sr" to match BUILTIN_READ_xxx
8237 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8238 if (read_flags == (uint32_t)-1)
8239 return EXIT_FAILURE;
8242 r = shell_builtin_read(set_local_var_from_halves,
8244 get_local_var_value("IFS"), /* can be NULL */
8252 if ((uintptr_t)r > 1) {
8253 bb_error_msg("%s", r);
8254 r = (char*)(uintptr_t)1;
8257 return (uintptr_t)r;
8260 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8261 * built-in 'set' handler
8263 * set [-abCefhmnuvx] [-o option] [argument...]
8264 * set [+abCefhmnuvx] [+o option] [argument...]
8265 * set -- [argument...]
8268 * Implementations shall support the options in both their hyphen and
8269 * plus-sign forms. These options can also be specified as options to sh.
8271 * Write out all variables and their values: set
8272 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8273 * Turn on the -x and -v options: set -xv
8274 * Unset all positional parameters: set --
8275 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8276 * Set the positional parameters to the expansion of x, even if x expands
8277 * with a leading '-' or '+': set -- $x
8279 * So far, we only support "set -- [argument...]" and some of the short names.
8281 static int FAST_FUNC builtin_set(char **argv)
8284 char **pp, **g_argv;
8285 char *arg = *++argv;
8289 for (e = G.top_var; e; e = e->next)
8291 return EXIT_SUCCESS;
8295 if (!strcmp(arg, "--")) {
8299 if (arg[0] != '+' && arg[0] != '-')
8301 for (n = 1; arg[n]; ++n)
8302 if (set_mode(arg[0], arg[n]))
8304 } while ((arg = *++argv) != NULL);
8305 /* Now argv[0] is 1st argument */
8308 return EXIT_SUCCESS;
8311 /* NB: G.global_argv[0] ($0) is never freed/changed */
8312 g_argv = G.global_argv;
8313 if (G.global_args_malloced) {
8319 G.global_args_malloced = 1;
8320 pp = xzalloc(sizeof(pp[0]) * 2);
8321 pp[0] = g_argv[0]; /* retain $0 */
8324 /* This realloc's G.global_argv */
8325 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8332 return EXIT_SUCCESS;
8334 /* Nothing known, so abort */
8336 bb_error_msg("set: %s: invalid option", arg);
8337 return EXIT_FAILURE;
8340 static int FAST_FUNC builtin_shift(char **argv)
8343 argv = skip_dash_dash(argv);
8347 if (n >= 0 && n < G.global_argc) {
8348 if (G.global_args_malloced) {
8351 free(G.global_argv[m++]);
8354 memmove(&G.global_argv[1], &G.global_argv[n+1],
8355 G.global_argc * sizeof(G.global_argv[0]));
8356 return EXIT_SUCCESS;
8358 return EXIT_FAILURE;
8361 static int FAST_FUNC builtin_source(char **argv)
8363 char *arg_path, *filename;
8366 #if ENABLE_HUSH_FUNCTIONS
8370 argv = skip_dash_dash(argv);
8373 /* bash says: "bash: .: filename argument required" */
8374 return 2; /* bash compat */
8377 if (!strchr(filename, '/')) {
8378 arg_path = find_in_path(filename);
8380 filename = arg_path;
8382 input = fopen_or_warn(filename, "r");
8385 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8386 return EXIT_FAILURE;
8388 close_on_exec_on(fileno(input));
8390 #if ENABLE_HUSH_FUNCTIONS
8391 sv_flg = G.flag_return_in_progress;
8392 /* "we are inside sourced file, ok to use return" */
8393 G.flag_return_in_progress = -1;
8395 save_and_replace_G_args(&sv, argv);
8397 parse_and_run_file(input);
8400 restore_G_args(&sv, argv);
8401 #if ENABLE_HUSH_FUNCTIONS
8402 G.flag_return_in_progress = sv_flg;
8405 return G.last_exitcode;
8408 static int FAST_FUNC builtin_umask(char **argv)
8414 argv = skip_dash_dash(argv);
8416 mode_t old_mask = mask;
8419 rc = bb_parse_mode(argv[0], &mask);
8424 * bash: umask: 'q': invalid symbolic mode operator
8425 * bash: umask: 999: octal number out of range
8427 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8432 printf("%04o\n", (unsigned) mask);
8433 /* fall through and restore mask which we set to 0 */
8437 return !rc; /* rc != 0 - success */
8440 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8441 static int FAST_FUNC builtin_unset(char **argv)
8446 /* "!": do not abort on errors */
8447 /* "+": stop at 1st non-option */
8448 opts = getopt32(argv, "!+vf");
8449 if (opts == (unsigned)-1)
8450 return EXIT_FAILURE;
8452 bb_error_msg("unset: -v and -f are exclusive");
8453 return EXIT_FAILURE;
8459 if (!(opts & 2)) { /* not -f */
8460 if (unset_local_var(*argv)) {
8461 /* unset <nonexistent_var> doesn't fail.
8462 * Error is when one tries to unset RO var.
8463 * Message was printed by unset_local_var. */
8467 #if ENABLE_HUSH_FUNCTIONS
8477 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8478 static int FAST_FUNC builtin_wait(char **argv)
8480 int ret = EXIT_SUCCESS;
8483 argv = skip_dash_dash(argv);
8484 if (argv[0] == NULL) {
8485 /* Don't care about wait results */
8486 /* Note 1: must wait until there are no more children */
8487 /* Note 2: must be interruptible */
8489 * $ sleep 3 & sleep 6 & wait
8494 * $ sleep 3 & sleep 6 & wait
8498 * ^C <-- after ~4 sec from keyboard
8501 sigaddset(&G.blocked_set, SIGCHLD);
8502 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8505 if (errno == ECHILD)
8507 /* Wait for SIGCHLD or any other signal of interest */
8508 /* sigtimedwait with infinite timeout: */
8509 sig = sigwaitinfo(&G.blocked_set, NULL);
8511 sig = check_and_run_traps(sig);
8512 if (sig && sig != SIGCHLD) { /* see note 2 */
8518 sigdelset(&G.blocked_set, SIGCHLD);
8519 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8523 /* This is probably buggy wrt interruptible-ness */
8525 pid_t pid = bb_strtou(*argv, NULL, 10);
8527 /* mimic bash message */
8528 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8529 return EXIT_FAILURE;
8531 if (waitpid(pid, &status, 0) == pid) {
8532 if (WIFSIGNALED(status))
8533 ret = 128 + WTERMSIG(status);
8534 else if (WIFEXITED(status))
8535 ret = WEXITSTATUS(status);
8539 bb_perror_msg("wait %s", *argv);
8548 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8549 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8552 def = bb_strtou(argv[1], NULL, 10);
8553 if (errno || def < def_min || argv[2]) {
8554 bb_error_msg("%s: bad arguments", argv[0]);
8562 #if ENABLE_HUSH_LOOPS
8563 static int FAST_FUNC builtin_break(char **argv)
8566 if (G.depth_of_loop == 0) {
8567 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8568 return EXIT_SUCCESS; /* bash compat */
8570 G.flag_break_continue++; /* BC_BREAK = 1 */
8572 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8573 if (depth == UINT_MAX)
8574 G.flag_break_continue = BC_BREAK;
8575 if (G.depth_of_loop < depth)
8576 G.depth_break_continue = G.depth_of_loop;
8578 return EXIT_SUCCESS;
8581 static int FAST_FUNC builtin_continue(char **argv)
8583 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8584 return builtin_break(argv);
8588 #if ENABLE_HUSH_FUNCTIONS
8589 static int FAST_FUNC builtin_return(char **argv)
8593 if (G.flag_return_in_progress != -1) {
8594 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8595 return EXIT_FAILURE; /* bash compat */
8598 G.flag_return_in_progress = 1;
8601 * out of range: wraps around at 256, does not error out
8602 * non-numeric param:
8603 * f() { false; return qwe; }; f; echo $?
8604 * bash: return: qwe: numeric argument required <== we do this
8605 * 255 <== we also do this
8607 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);