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);
3162 nommu_addchr(as_string, ch);
3163 if ((ch == '\n' || ch == EOF)
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;
3171 while (ch == '\n') {
3172 o_addchr(&heredoc, ch);
3175 past_EOL = heredoc.length;
3177 ch = i_getch(input);
3179 nommu_addchr(as_string, ch);
3180 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3184 o_free_unsafe(&heredoc);
3187 o_addchr(&heredoc, ch);
3188 nommu_addchr(as_string, ch);
3189 if (prev == '\\' && ch == '\\')
3190 /* Correctly handle foo\\<eol> (not a line cont.) */
3191 prev = 0; /* not \ */
3197 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3198 * and load them all. There should be exactly heredoc_cnt of them.
3200 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3202 struct pipe *pi = ctx->list_head;
3204 while (pi && heredoc_cnt) {
3206 struct command *cmd = pi->cmds;
3208 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3210 cmd->argv ? cmd->argv[0] : "NONE");
3211 for (i = 0; i < pi->num_cmds; i++) {
3212 struct redir_struct *redir = cmd->redirects;
3214 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3215 i, cmd->argv ? cmd->argv[0] : "NONE");
3217 if (redir->rd_type == REDIRECT_HEREDOC) {
3220 redir->rd_type = REDIRECT_HEREDOC2;
3221 /* redir->rd_dup is (ab)used to indicate <<- */
3222 p = fetch_till_str(&ctx->as_string, input,
3223 redir->rd_filename, redir->rd_dup);
3225 syntax_error("unexpected EOF in here document");
3228 free(redir->rd_filename);
3229 redir->rd_filename = p;
3232 redir = redir->next;
3239 /* Should be 0. If it isn't, it's a parse error */
3241 bb_error_msg_and_die("heredoc BUG 2");
3247 static int run_list(struct pipe *pi);
3249 #define parse_stream(pstring, input, end_trigger) \
3250 parse_stream(input, end_trigger)
3252 static struct pipe *parse_stream(char **pstring,
3253 struct in_str *input,
3257 #if !ENABLE_HUSH_FUNCTIONS
3258 #define parse_group(dest, ctx, input, ch) \
3259 parse_group(ctx, input, ch)
3261 static int parse_group(o_string *dest, struct parse_context *ctx,
3262 struct in_str *input, int ch)
3264 /* dest contains characters seen prior to ( or {.
3265 * Typically it's empty, but for function defs,
3266 * it contains function name (without '()'). */
3267 struct pipe *pipe_list;
3269 struct command *command = ctx->command;
3271 debug_printf_parse("parse_group entered\n");
3272 #if ENABLE_HUSH_FUNCTIONS
3273 if (ch == '(' && !dest->has_quoted_part) {
3275 if (done_word(dest, ctx))
3278 goto skip; /* (... */
3279 if (command->argv[1]) { /* word word ... (... */
3280 syntax_error_unexpected_ch('(');
3283 /* it is "word(..." or "word (..." */
3285 ch = i_getch(input);
3286 while (ch == ' ' || ch == '\t');
3288 syntax_error_unexpected_ch(ch);
3291 nommu_addchr(&ctx->as_string, ch);
3293 ch = i_getch(input);
3294 while (ch == ' ' || ch == '\t' || ch == '\n');
3296 syntax_error_unexpected_ch(ch);
3299 nommu_addchr(&ctx->as_string, ch);
3300 command->cmd_type = CMD_FUNCDEF;
3305 #if 0 /* Prevented by caller */
3306 if (command->argv /* word [word]{... */
3307 || dest->length /* word{... */
3308 || dest->has_quoted_part /* ""{... */
3311 debug_printf_parse("parse_group return 1: "
3312 "syntax error, groups and arglists don't mix\n");
3317 #if ENABLE_HUSH_FUNCTIONS
3323 command->cmd_type = CMD_SUBSHELL;
3325 /* bash does not allow "{echo...", requires whitespace */
3326 ch = i_getch(input);
3327 if (ch != ' ' && ch != '\t' && ch != '\n') {
3328 syntax_error_unexpected_ch(ch);
3331 nommu_addchr(&ctx->as_string, ch);
3336 # define as_string NULL
3338 char *as_string = NULL;
3340 pipe_list = parse_stream(&as_string, input, endch);
3343 o_addstr(&ctx->as_string, as_string);
3345 /* empty ()/{} or parse error? */
3346 if (!pipe_list || pipe_list == ERR_PTR) {
3347 /* parse_stream already emitted error msg */
3350 debug_printf_parse("parse_group return 1: "
3351 "parse_stream returned %p\n", pipe_list);
3354 command->group = pipe_list;
3356 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3357 command->group_as_string = as_string;
3358 debug_printf_parse("end of group, remembering as:'%s'\n",
3359 command->group_as_string);
3363 debug_printf_parse("parse_group return 0\n");
3365 /* command remains "open", available for possible redirects */
3368 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3369 /* Subroutines for copying $(...) and `...` things */
3370 static void add_till_backquote(o_string *dest, struct in_str *input);
3372 static void add_till_single_quote(o_string *dest, struct in_str *input)
3375 int ch = i_getch(input);
3377 syntax_error_unterm_ch('\'');
3378 /*xfunc_die(); - redundant */
3385 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3386 static void add_till_double_quote(o_string *dest, struct in_str *input)
3389 int ch = i_getch(input);
3391 syntax_error_unterm_ch('"');
3392 /*xfunc_die(); - redundant */
3396 if (ch == '\\') { /* \x. Copy both chars. */
3398 ch = i_getch(input);
3402 add_till_backquote(dest, input);
3406 //if (ch == '$') ...
3409 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3411 * "Within the backquoted style of command substitution, backslash
3412 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3413 * The search for the matching backquote shall be satisfied by the first
3414 * backquote found without a preceding backslash; during this search,
3415 * if a non-escaped backquote is encountered within a shell comment,
3416 * a here-document, an embedded command substitution of the $(command)
3417 * form, or a quoted string, undefined results occur. A single-quoted
3418 * or double-quoted string that begins, but does not end, within the
3419 * "`...`" sequence produces undefined results."
3421 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3423 static void add_till_backquote(o_string *dest, struct in_str *input)
3426 int ch = i_getch(input);
3428 syntax_error_unterm_ch('`');
3429 /*xfunc_die(); - redundant */
3434 /* \x. Copy both chars unless it is \` */
3435 int ch2 = i_getch(input);
3437 syntax_error_unterm_ch('`');
3438 /*xfunc_die(); - redundant */
3440 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3447 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3448 * quoting and nested ()s.
3449 * "With the $(command) style of command substitution, all characters
3450 * following the open parenthesis to the matching closing parenthesis
3451 * constitute the command. Any valid shell script can be used for command,
3452 * except a script consisting solely of redirections which produces
3453 * unspecified results."
3455 * echo $(echo '(TEST)' BEST) (TEST) BEST
3456 * echo $(echo 'TEST)' BEST) TEST) BEST
3457 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3459 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3460 * can contain arbitrary constructs, just like $(cmd).
3461 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3462 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3464 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3465 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3468 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3469 # if ENABLE_HUSH_BASH_COMPAT
3470 char end_char2 = end_ch >> 8;
3472 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3475 ch = i_getch(input);
3477 syntax_error_unterm_ch(end_ch);
3478 /*xfunc_die(); - redundant */
3480 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3483 /* we look for closing )) of $((EXPR)) */
3484 if (i_peek(input) == end_ch) {
3485 i_getch(input); /* eat second ')' */
3490 if (ch == '(' || ch == '{') {
3491 ch = (ch == '(' ? ')' : '}');
3492 add_till_closing_bracket(dest, input, ch);
3497 add_till_single_quote(dest, input);
3502 add_till_double_quote(dest, input);
3507 add_till_backquote(dest, input);
3512 /* \x. Copy verbatim. Important for \(, \) */
3513 ch = i_getch(input);
3515 syntax_error_unterm_ch(')');
3516 /*xfunc_die(); - redundant */
3524 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3526 /* Return code: 0 for OK, 1 for syntax error */
3528 #define parse_dollar(as_string, dest, input, quote_mask) \
3529 parse_dollar(dest, input, quote_mask)
3530 #define as_string NULL
3532 static int parse_dollar(o_string *as_string,
3534 struct in_str *input, unsigned char quote_mask)
3536 int ch = i_peek(input); /* first character after the $ */
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 /* It should be ${?}, or ${#var},
3579 * or even ${?+subst} - operator acting on a special variable,
3580 * or the beginning of variable name.
3583 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3586 syntax_error_unterm_str("${name}");
3587 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
3590 nommu_addchr(as_string, ch);
3593 /* It's possible to just call add_till_closing_bracket() at this point.
3594 * However, this regresses some of our testsuite cases
3595 * which check invalid constructs like ${%}.
3596 * Oh well... let's check that the var name part is fine... */
3602 debug_printf_parse(": '%c'\n", ch);
3604 ch = i_getch(input);
3605 nommu_addchr(as_string, ch);
3609 if (!isalnum(ch) && ch != '_') {
3611 unsigned char last_ch;
3612 /* handle parameter expansions
3613 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3615 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3616 goto bad_dollar_syntax;
3618 /* Eat everything until closing '}' (or ':') */
3620 if (ENABLE_HUSH_BASH_COMPAT
3622 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3624 /* It's ${var:N[:M]} thing */
3625 end_ch = '}' * 0x100 + ':';
3627 if (ENABLE_HUSH_BASH_COMPAT
3630 /* It's ${var/[/]pattern[/repl]} thing */
3631 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3633 nommu_addchr(as_string, '/');
3636 end_ch = '}' * 0x100 + '/';
3642 #if ENABLE_HUSH_DOLLAR_OPS
3643 last_ch = add_till_closing_bracket(dest, input, end_ch);
3645 #error Simple code to only allow ${var} is not implemented
3648 o_addstr(as_string, dest->data + pos);
3649 o_addchr(as_string, last_ch);
3652 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3653 /* close the first block: */
3654 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3655 /* while parsing N from ${var:N[:M]}
3656 * or pattern from ${var/[/]pattern[/repl]} */
3657 if ((end_ch & 0xff) == last_ch) {
3658 /* got ':' or '/'- parse the rest */
3663 if (end_ch == '}' * 0x100 + ':') {
3664 /* it's ${var:N} - emulate :999999999 */
3665 o_addstr(dest, "999999999");
3666 } /* else: it's ${var/[/]pattern} */
3671 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3674 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3678 ch = i_getch(input);
3679 nommu_addchr(as_string, ch);
3680 # if ENABLE_SH_MATH_SUPPORT
3681 if (i_peek(input) == '(') {
3682 ch = i_getch(input);
3683 nommu_addchr(as_string, ch);
3684 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3685 o_addchr(dest, /*quote_mask |*/ '+');
3688 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
3690 o_addstr(as_string, dest->data + pos);
3691 o_addchr(as_string, ')');
3692 o_addchr(as_string, ')');
3694 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3698 # if ENABLE_HUSH_TICK
3699 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3700 o_addchr(dest, quote_mask | '`');
3703 add_till_closing_bracket(dest, input, ')');
3705 o_addstr(as_string, dest->data + pos);
3706 o_addchr(as_string, ')');
3708 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3714 ch = i_getch(input);
3715 nommu_addchr(as_string, ch);
3717 if (isalnum(ch)) { /* it's $_name or $_123 */
3722 /* TODO: $_ and $-: */
3723 /* $_ Shell or shell script name; or last argument of last command
3724 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
3725 * but in command's env, set to full pathname used to invoke it */
3726 /* $- Option flags set by set builtin or shell options (-i etc) */
3728 o_addQchr(dest, '$');
3730 debug_printf_parse("parse_dollar return 0\n");
3736 #define parse_stream_dquoted(as_string, dest, input, dquote_end, dquoted) \
3737 parse_stream_dquoted(dest, input, dquote_end, dquoted)
3738 #define as_string NULL
3740 static int parse_stream_dquoted(o_string *as_string,
3742 struct in_str *input,
3750 ch = i_getch(input);
3752 nommu_addchr(as_string, ch);
3753 if (ch == dquote_end) { /* may be only '"' or EOF */
3754 debug_printf_parse("parse_stream_dquoted return 0\n");
3757 /* note: can't move it above ch == dquote_end check! */
3759 syntax_error_unterm_ch('"');
3760 /*xfunc_die(); - redundant */
3764 next = i_peek(input);
3766 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
3767 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3768 if (dquoted && ch == '\\') {
3770 syntax_error("\\<eof>");
3774 * "The backslash retains its special meaning [in "..."]
3775 * only when followed by one of the following characters:
3776 * $, `, ", \, or <newline>. A double quote may be quoted
3777 * within double quotes by preceding it with a backslash."
3778 * NB: in (unquoted) heredoc, above does not apply to ".
3780 if (next == dquote_end || strchr("$`\\\n", next) != NULL) {
3781 ch = i_getch(input); /* eat next */
3783 goto again; /* skip \<newline> */
3784 } /* else: ch remains == '\\', and we double it */
3785 o_addqchr(dest, ch);
3786 nommu_addchr(as_string, ch);
3790 //CHECK: 0x80? or dquoted?
3791 if (parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80) != 0) {
3792 debug_printf_parse("parse_stream_dquoted return 1: "
3793 "parse_dollar returned non-0\n");
3798 #if ENABLE_HUSH_TICK
3800 //unsigned pos = dest->length;
3801 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3802 o_addchr(dest, 0x80 | '`');
3803 add_till_backquote(dest, input);
3804 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3805 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3809 o_addQchr(dest, ch);
3815 * Scan input until EOF or end_trigger char.
3816 * Return a list of pipes to execute, or NULL on EOF
3817 * or if end_trigger character is met.
3818 * On syntax error, exit is shell is not interactive,
3819 * reset parsing machinery and start parsing anew,
3820 * or return ERR_PTR.
3822 static struct pipe *parse_stream(char **pstring,
3823 struct in_str *input,
3826 struct parse_context ctx;
3827 o_string dest = NULL_O_STRING;
3830 /* Single-quote triggers a bypass of the main loop until its mate is
3831 * found. When recursing, quote state is passed in via dest->o_expflags.
3833 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
3834 end_trigger ? end_trigger : 'X');
3837 /* If very first arg is "" or '', dest.data may end up NULL.
3838 * Preventing this: */
3839 o_addchr(&dest, '\0');
3842 /* We used to separate words on $IFS here. This was wrong.
3843 * $IFS is used only for word splitting when $var is expanded,
3844 * here we should use blank chars as separators, not $IFS
3847 reset: /* we come back here only on syntax errors in interactive shell */
3849 #if ENABLE_HUSH_INTERACTIVE
3850 input->promptmode = 0; /* PS1 */
3852 if (MAYBE_ASSIGNMENT != 0)
3853 dest.o_assignment = MAYBE_ASSIGNMENT;
3854 initialize_context(&ctx);
3857 const char *is_blank;
3858 const char *is_special;
3862 redir_type redir_style;
3864 ch = i_getch(input);
3865 debug_printf_parse(": ch=%c (%d) escape=%d\n",
3866 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3871 syntax_error_unterm_str("here document");
3874 /* end_trigger == '}' case errors out earlier,
3875 * checking only ')' */
3876 if (end_trigger == ')') {
3877 syntax_error_unterm_ch('('); /* exits */
3878 /* goto parse_error; */
3881 if (done_word(&dest, &ctx)) {
3885 done_pipe(&ctx, PIPE_SEQ);
3887 /* If we got nothing... */
3888 /* (this makes bare "&" cmd a no-op.
3889 * bash says: "syntax error near unexpected token '&'") */
3890 if (pi->num_cmds == 0
3891 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
3897 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
3899 *pstring = ctx.as_string.data;
3901 o_free_unsafe(&ctx.as_string);
3904 debug_printf_parse("parse_stream return %p\n", pi);
3907 nommu_addchr(&ctx.as_string, ch);
3911 next = i_peek(input);
3913 is_special = "{}<>;&|()#'" /* special outside of "str" */
3914 "\\$\"" IF_HUSH_TICK("`"); /* always special */
3915 /* Are { and } special here? */
3916 if (ctx.command->argv /* word [word]{... - non-special */
3917 || dest.length /* word{... - non-special */
3918 || dest.has_quoted_part /* ""{... - non-special */
3919 || (next != ';' /* }; - special */
3920 && next != ')' /* }) - special */
3921 && next != '&' /* }& and }&& ... - special */
3922 && next != '|' /* }|| ... - special */
3923 && !strchr(defifs, next) /* {word - non-special */
3926 /* They are not special, skip "{}" */
3929 is_special = strchr(is_special, ch);
3930 is_blank = strchr(defifs, ch);
3932 if (!is_special && !is_blank) { /* ordinary char */
3934 o_addQchr(&dest, ch);
3935 if ((dest.o_assignment == MAYBE_ASSIGNMENT
3936 || dest.o_assignment == WORD_IS_KEYWORD)
3938 && is_well_formed_var_name(dest.data, '=')
3940 dest.o_assignment = DEFINITELY_ASSIGNMENT;
3946 if (done_word(&dest, &ctx)) {
3950 #if ENABLE_HUSH_CASE
3951 /* "case ... in <newline> word) ..." -
3952 * newlines are ignored (but ';' wouldn't be) */
3953 if (ctx.command->argv == NULL
3954 && ctx.ctx_res_w == RES_MATCH
3959 /* Treat newline as a command separator. */
3960 done_pipe(&ctx, PIPE_SEQ);
3961 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
3963 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
3968 dest.o_assignment = MAYBE_ASSIGNMENT;
3970 /* note: if (is_blank) continue;
3971 * will still trigger for us */
3975 /* "cmd}" or "cmd }..." without semicolon or &:
3976 * } is an ordinary char in this case, even inside { cmd; }
3977 * Pathological example: { ""}; } should exec "}" cmd
3980 if (!IS_NULL_CMD(ctx.command) /* cmd } */
3981 || dest.length != 0 /* word} */
3982 || dest.has_quoted_part /* ""} */
3986 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
3987 goto skip_end_trigger;
3988 /* else: } does terminate a group */
3991 if (end_trigger && end_trigger == ch
3992 && (ch != ';' || heredoc_cnt == 0)
3993 #if ENABLE_HUSH_CASE
3995 || ctx.ctx_res_w != RES_MATCH
3996 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4001 /* This is technically valid:
4002 * { cat <<HERE; }; echo Ok
4006 * but we don't support this.
4007 * We require heredoc to be in enclosing {}/(),
4010 syntax_error_unterm_str("here document");
4013 if (done_word(&dest, &ctx)) {
4016 done_pipe(&ctx, PIPE_SEQ);
4017 dest.o_assignment = MAYBE_ASSIGNMENT;
4018 /* Do we sit outside of any if's, loops or case's? */
4020 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4024 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4026 *pstring = ctx.as_string.data;
4028 o_free_unsafe(&ctx.as_string);
4031 debug_printf_parse("parse_stream return %p: "
4032 "end_trigger char found\n",
4034 return ctx.list_head;
4041 /* Catch <, > before deciding whether this word is
4042 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4045 redir_fd = redirect_opt_num(&dest);
4046 if (done_word(&dest, &ctx)) {
4049 redir_style = REDIRECT_OVERWRITE;
4051 redir_style = REDIRECT_APPEND;
4052 ch = i_getch(input);
4053 nommu_addchr(&ctx.as_string, ch);
4056 else if (next == '(') {
4057 syntax_error(">(process) not supported");
4061 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4063 continue; /* back to top of while (1) */
4065 redir_fd = redirect_opt_num(&dest);
4066 if (done_word(&dest, &ctx)) {
4069 redir_style = REDIRECT_INPUT;
4071 redir_style = REDIRECT_HEREDOC;
4073 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4074 ch = i_getch(input);
4075 nommu_addchr(&ctx.as_string, ch);
4076 } else if (next == '>') {
4077 redir_style = REDIRECT_IO;
4078 ch = i_getch(input);
4079 nommu_addchr(&ctx.as_string, ch);
4082 else if (next == '(') {
4083 syntax_error("<(process) not supported");
4087 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4089 continue; /* back to top of while (1) */
4092 if (dest.o_assignment == MAYBE_ASSIGNMENT
4093 /* check that we are not in word in "a=1 2>word b=1": */
4094 && !ctx.pending_redirect
4096 /* ch is a special char and thus this word
4097 * cannot be an assignment */
4098 dest.o_assignment = NOT_ASSIGNMENT;
4101 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4105 if (dest.length == 0) {
4108 if (ch == EOF || ch == '\n')
4111 /* note: we do not add it to &ctx.as_string */
4113 nommu_addchr(&ctx.as_string, '\n');
4115 o_addQchr(&dest, ch);
4120 syntax_error("\\<eof>");
4123 ch = i_getch(input);
4125 o_addchr(&dest, '\\');
4126 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4127 o_addchr(&dest, ch);
4128 nommu_addchr(&ctx.as_string, ch);
4129 /* Example: echo Hello \2>file
4130 * we need to know that word 2 is quoted */
4131 dest.has_quoted_part = 1;
4135 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
4136 ctx.as_string.data[--ctx.as_string.length] = '\0';
4141 if (parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0) != 0) {
4142 debug_printf_parse("parse_stream parse error: "
4143 "parse_dollar returned non-0\n");
4148 dest.has_quoted_part = 1;
4150 ch = i_getch(input);
4152 syntax_error_unterm_ch('\'');
4153 /*xfunc_die(); - redundant */
4155 nommu_addchr(&ctx.as_string, ch);
4158 o_addqchr(&dest, ch);
4162 dest.has_quoted_part = 1;
4163 if (dest.o_assignment == NOT_ASSIGNMENT)
4164 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4165 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"', /*dquoted:*/ 1))
4167 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4169 #if ENABLE_HUSH_TICK
4173 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4174 o_addchr(&dest, '`');
4176 add_till_backquote(&dest, input);
4178 o_addstr(&ctx.as_string, dest.data + pos);
4179 o_addchr(&ctx.as_string, '`');
4181 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4182 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4187 #if ENABLE_HUSH_CASE
4190 if (done_word(&dest, &ctx)) {
4193 done_pipe(&ctx, PIPE_SEQ);
4194 #if ENABLE_HUSH_CASE
4195 /* Eat multiple semicolons, detect
4196 * whether it means something special */
4201 ch = i_getch(input);
4202 nommu_addchr(&ctx.as_string, ch);
4203 if (ctx.ctx_res_w == RES_CASE_BODY) {
4204 ctx.ctx_dsemicolon = 1;
4205 ctx.ctx_res_w = RES_MATCH;
4211 /* We just finished a cmd. New one may start
4212 * with an assignment */
4213 dest.o_assignment = MAYBE_ASSIGNMENT;
4216 if (done_word(&dest, &ctx)) {
4220 ch = i_getch(input);
4221 nommu_addchr(&ctx.as_string, ch);
4222 done_pipe(&ctx, PIPE_AND);
4224 done_pipe(&ctx, PIPE_BG);
4228 if (done_word(&dest, &ctx)) {
4231 #if ENABLE_HUSH_CASE
4232 if (ctx.ctx_res_w == RES_MATCH)
4233 break; /* we are in case's "word | word)" */
4235 if (next == '|') { /* || */
4236 ch = i_getch(input);
4237 nommu_addchr(&ctx.as_string, ch);
4238 done_pipe(&ctx, PIPE_OR);
4240 /* we could pick up a file descriptor choice here
4241 * with redirect_opt_num(), but bash doesn't do it.
4242 * "echo foo 2| cat" yields "foo 2". */
4245 o_reset_to_empty_unquoted(&ctx.as_string);
4250 #if ENABLE_HUSH_CASE
4251 /* "case... in [(]word)..." - skip '(' */
4252 if (ctx.ctx_res_w == RES_MATCH
4253 && ctx.command->argv == NULL /* not (word|(... */
4254 && dest.length == 0 /* not word(... */
4255 && dest.has_quoted_part == 0 /* not ""(... */
4261 if (parse_group(&dest, &ctx, input, ch) != 0) {
4266 #if ENABLE_HUSH_CASE
4267 if (ctx.ctx_res_w == RES_MATCH)
4271 /* proper use of this character is caught by end_trigger:
4272 * if we see {, we call parse_group(..., end_trigger='}')
4273 * and it will match } earlier (not here). */
4274 syntax_error_unexpected_ch(ch);
4278 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4284 struct parse_context *pctx;
4285 IF_HAS_KEYWORDS(struct parse_context *p2;)
4287 /* Clean up allocated tree.
4288 * Sample for finding leaks on syntax error recovery path.
4289 * Run it from interactive shell, watch pmap `pidof hush`.
4290 * while if false; then false; fi; do break; fi
4291 * Samples to catch leaks at execution:
4292 * while if (true | {true;}); then echo ok; fi; do break; done
4293 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4297 /* Update pipe/command counts,
4298 * otherwise freeing may miss some */
4299 done_pipe(pctx, PIPE_SEQ);
4300 debug_printf_clean("freeing list %p from ctx %p\n",
4301 pctx->list_head, pctx);
4302 debug_print_tree(pctx->list_head, 0);
4303 free_pipe_list(pctx->list_head);
4304 debug_printf_clean("freed list %p\n", pctx->list_head);
4306 o_free_unsafe(&pctx->as_string);
4308 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4312 IF_HAS_KEYWORDS(pctx = p2;)
4313 } while (HAS_KEYWORDS && pctx);
4314 /* Free text, clear all dest fields */
4316 /* If we are not in top-level parse, we return,
4317 * our caller will propagate error.
4319 if (end_trigger != ';') {
4327 /* Discard cached input, force prompt */
4329 IF_HUSH_INTERACTIVE(input->promptme = 1;)
4335 /*** Execution routines ***/
4337 /* Expansion can recurse, need forward decls: */
4338 static char *expand_string_to_string(const char *str, int do_unbackslash);
4339 static int process_command_subs(o_string *dest, const char *s);
4341 /* expand_strvec_to_strvec() takes a list of strings, expands
4342 * all variable references within and returns a pointer to
4343 * a list of expanded strings, possibly with larger number
4344 * of strings. (Think VAR="a b"; echo $VAR).
4345 * This new list is allocated as a single malloc block.
4346 * NULL-terminated list of char* pointers is at the beginning of it,
4347 * followed by strings themselves.
4348 * Caller can deallocate entire list by single free(list). */
4350 /* Store given string, finalizing the word and starting new one whenever
4351 * we encounter IFS char(s). This is used for expanding variable values.
4352 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
4353 static int expand_on_ifs(o_string *output, int n, const char *str)
4356 int word_len = strcspn(str, G.ifs);
4358 if (!(output->o_expflags & EXP_FLAG_GLOB))
4359 o_addblock(output, str, word_len);
4361 /* Protect backslashes against globbing up :)
4362 * Example: "v='\*'; echo b$v" prints "b\*"
4363 * (and does not try to glob on "*")
4365 o_addblock_duplicate_backslash(output, str, word_len);
4366 /*/ Why can't we do it easier? */
4367 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4368 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4372 if (!*str) /* EOL - do not finalize word */
4374 o_addchr(output, '\0');
4375 debug_print_list("expand_on_ifs", output, n);
4376 n = o_save_ptr(output, n);
4377 str += strspn(str, G.ifs); /* skip ifs chars */
4379 debug_print_list("expand_on_ifs[1]", output, n);
4383 /* Helper to expand $((...)) and heredoc body. These act as if
4384 * they are in double quotes, with the exception that they are not :).
4385 * Just the rules are similar: "expand only $var and `cmd`"
4387 * Returns malloced string.
4388 * As an optimization, we return NULL if expansion is not needed.
4390 static char *expand_pseudo_dquoted(const char *str, int dquoted, int do_unbackslash)
4393 struct in_str input;
4394 o_string dest = NULL_O_STRING;
4396 if (!strchr(str, '$')
4397 && !strchr(str, '\\')
4398 #if ENABLE_HUSH_TICK
4399 && !strchr(str, '`')
4405 /* We need to expand. Example:
4406 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4408 setup_string_in_str(&input, str);
4409 parse_stream_dquoted(NULL, &dest, &input, EOF, dquoted);
4410 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4411 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4412 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4413 o_free_unsafe(&dest);
4417 #if ENABLE_SH_MATH_SUPPORT
4418 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
4420 arith_eval_hooks_t hooks;
4424 hooks.lookupvar = get_local_var_value;
4425 hooks.setvar = set_local_var_from_halves;
4426 //hooks.endofname = endofname;
4427 exp_str = expand_pseudo_dquoted(arg, /*dquoted:*/ 1, /*unbackslash:*/ 1);
4428 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
4434 #if ENABLE_HUSH_BASH_COMPAT
4435 /* ${var/[/]pattern[/repl]} helpers */
4436 static char *strstr_pattern(char *val, const char *pattern, int *size)
4439 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4440 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4447 /* Optimization: if "*pat" did not match the start of "string",
4448 * we know that "tring", "ring" etc will not match too:
4450 if (pattern[0] == '*')
4455 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4457 char *result = NULL;
4458 unsigned res_len = 0;
4459 unsigned repl_len = strlen(repl);
4463 char *s = strstr_pattern(val, pattern, &size);
4467 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4468 memcpy(result + res_len, val, s - val);
4470 strcpy(result + res_len, repl);
4471 res_len += repl_len;
4472 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4478 if (val[0] && result) {
4479 result = xrealloc(result, res_len + strlen(val) + 1);
4480 strcpy(result + res_len, val);
4481 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4483 debug_printf_varexp("result:'%s'\n", result);
4489 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4491 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4493 const char *val = NULL;
4494 char *to_be_freed = NULL;
4499 char exp_save = exp_save; /* for compiler */
4500 char *exp_saveptr; /* points to expansion operator */
4501 char *exp_word = exp_word; /* for compiler */
4504 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4506 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4508 first_char = arg[0] = arg0 & 0x7f;
4511 if (first_char == '#' /* ${#... */
4512 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4514 /* It must be length operator: ${#var} */
4518 /* Maybe handle parameter expansion */
4519 if (exp_saveptr /* if 2nd char is one of expansion operators */
4520 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4522 /* ${?:0}, ${#[:]%0} etc */
4523 exp_saveptr = var + 1;
4525 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4526 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4528 exp_op = exp_save = *exp_saveptr;
4530 exp_word = exp_saveptr + 1;
4531 if (exp_op == ':') {
4532 exp_op = *exp_word++;
4533 //TODO: try ${var:} and ${var:bogus} in non-bash config
4534 if (ENABLE_HUSH_BASH_COMPAT
4535 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4537 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4542 *exp_saveptr = '\0';
4543 } /* else: it's not an expansion op, but bare ${var} */
4546 /* Look up the variable in question */
4547 if (isdigit(var[0])) {
4548 /* parse_dollar should have vetted var for us */
4549 int n = xatoi_positive(var);
4550 if (n < G.global_argc)
4551 val = G.global_argv[n];
4552 /* else val remains NULL: $N with too big N */
4556 val = utoa(G.root_pid);
4558 case '!': /* bg pid */
4559 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
4561 case '?': /* exitcode */
4562 val = utoa(G.last_exitcode);
4564 case '#': /* argc */
4565 val = utoa(G.global_argc ? G.global_argc-1 : 0);
4568 val = get_local_var_value(var);
4572 /* Handle any expansions */
4573 if (exp_op == 'L') {
4574 debug_printf_expand("expand: length(%s)=", val);
4575 val = utoa(val ? strlen(val) : 0);
4576 debug_printf_expand("%s\n", val);
4577 } else if (exp_op) {
4578 if (exp_op == '%' || exp_op == '#') {
4579 /* Standard-mandated substring removal ops:
4580 * ${parameter%word} - remove smallest suffix pattern
4581 * ${parameter%%word} - remove largest suffix pattern
4582 * ${parameter#word} - remove smallest prefix pattern
4583 * ${parameter##word} - remove largest prefix pattern
4585 * Word is expanded to produce a glob pattern.
4586 * Then var's value is matched to it and matching part removed.
4588 if (val && val[0]) {
4591 unsigned scan_flags = pick_scan(exp_op, *exp_word);
4592 if (exp_op == *exp_word) /* ## or %% */
4594 //TODO: avoid xstrdup unless needed
4595 // (see HACK ALERT below for an example)
4596 val = to_be_freed = xstrdup(val);
4597 exp_exp_word = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 1, /*unbackslash:*/ 1);
4599 exp_word = exp_exp_word;
4600 loc = scan_and_match(to_be_freed, exp_word, scan_flags);
4601 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
4602 // exp_op, to_be_freed, exp_word, loc);
4604 if (loc) { /* match was found */
4605 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
4612 #if ENABLE_HUSH_BASH_COMPAT
4613 else if (exp_op == '/' || exp_op == '\\') {
4614 /* It's ${var/[/]pattern[/repl]} thing.
4615 * Note that in encoded form it has TWO parts:
4616 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4618 /* Empty variable always gives nothing: */
4619 // "v=''; echo ${v/*/w}" prints "", not "w"
4620 if (val && val[0]) {
4621 /* It's ${var/[/]pattern[/repl]} thing */
4623 * Pattern is taken literally, while
4624 * repl should be unbackslashed and globbed
4625 * by the usual expansion rules:
4627 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
4628 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
4629 * v='a bz'; echo ${v/a*z/a*z} prints "az"
4630 * v='a bz'; echo ${v/a*z/\z} prints "z"
4631 * (note that a*z _pattern_ is never globbed!)
4633 char *pattern, *repl, *t;
4634 pattern = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 0, /*unbackslash:*/ 0);
4636 pattern = xstrdup(exp_word);
4637 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
4638 *p++ = SPECIAL_VAR_SYMBOL;
4640 p = strchr(p, SPECIAL_VAR_SYMBOL);
4642 repl = expand_pseudo_dquoted(exp_word, /*dquoted:*/ arg0 & 0x80, /*unbackslash:*/ 1);
4643 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
4644 /* HACK ALERT. We depend here on the fact that
4645 * G.global_argv and results of utoa and get_local_var_value
4646 * are actually in writable memory:
4647 * replace_pattern momentarily stores NULs there. */
4649 to_be_freed = replace_pattern(t,
4651 (repl ? repl : exp_word),
4653 if (to_be_freed) /* at least one replace happened */
4660 else if (exp_op == ':') {
4661 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
4662 /* It's ${var:N[:M]} bashism.
4663 * Note that in encoded form it has TWO parts:
4664 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
4669 beg = expand_and_evaluate_arith(exp_word, &errcode);
4670 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
4671 *p++ = SPECIAL_VAR_SYMBOL;
4673 p = strchr(p, SPECIAL_VAR_SYMBOL);
4675 len = expand_and_evaluate_arith(exp_word, &errcode);
4676 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
4678 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
4679 if (beg < 0) /* bash compat */
4681 debug_printf_varexp("from val:'%s'\n", val);
4682 if (len == 0 || !val || beg >= strlen(val))
4685 /* Paranoia. What if user entered 9999999999999
4686 * which fits in arith_t but not int? */
4689 val = to_be_freed = xstrndup(val + beg, len);
4691 debug_printf_varexp("val:'%s'\n", val);
4695 die_if_script("malformed ${%s:...}", var);
4698 } else { /* one of "-=+?" */
4699 /* Standard-mandated substitution ops:
4700 * ${var?word} - indicate error if unset
4701 * If var is unset, word (or a message indicating it is unset
4702 * if word is null) is written to standard error
4703 * and the shell exits with a non-zero exit status.
4704 * Otherwise, the value of var is substituted.
4705 * ${var-word} - use default value
4706 * If var is unset, word is substituted.
4707 * ${var=word} - assign and use default value
4708 * If var is unset, word is assigned to var.
4709 * In all cases, final value of var is substituted.
4710 * ${var+word} - use alternative value
4711 * If var is unset, null is substituted.
4712 * Otherwise, word is substituted.
4714 * Word is subjected to tilde expansion, parameter expansion,
4715 * command substitution, and arithmetic expansion.
4716 * If word is not needed, it is not expanded.
4718 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
4719 * but also treat null var as if it is unset.
4721 int use_word = (!val || ((exp_save == ':') && !val[0]));
4723 use_word = !use_word;
4724 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
4725 (exp_save == ':') ? "true" : "false", use_word);
4727 to_be_freed = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 1, /*unbackslash:*/ 1);
4729 exp_word = to_be_freed;
4730 if (exp_op == '?') {
4731 /* mimic bash message */
4732 die_if_script("%s: %s",
4734 exp_word[0] ? exp_word : "parameter null or not set"
4736 //TODO: how interactive bash aborts expansion mid-command?
4741 if (exp_op == '=') {
4742 /* ${var=[word]} or ${var:=[word]} */
4743 if (isdigit(var[0]) || var[0] == '#') {
4744 /* mimic bash message */
4745 die_if_script("$%s: cannot assign in this way", var);
4748 char *new_var = xasprintf("%s=%s", var, val);
4749 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4753 } /* one of "-=+?" */
4755 *exp_saveptr = exp_save;
4761 *to_be_freed_pp = to_be_freed;
4765 /* Expand all variable references in given string, adding words to list[]
4766 * at n, n+1,... positions. Return updated n (so that list[n] is next one
4767 * to be filled). This routine is extremely tricky: has to deal with
4768 * variables/parameters with whitespace, $* and $@, and constructs like
4769 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
4770 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
4772 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
4773 * expansion of right-hand side of assignment == 1-element expand.
4775 char cant_be_null = 0; /* only bit 0x80 matters */
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 /* Fetch special var name (if it is indeed one of them)
4800 * and quote bit, force the bit on if singleword expansion -
4801 * important for not getting v=$@ expand to many words. */
4802 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
4804 /* Is this variable quoted and thus expansion can't be null?
4805 * "$@" is special. Even if quoted, it can still
4806 * expand to nothing (not even an empty string),
4807 * thus it is excluded. */
4808 if ((first_ch & 0x7f) != '@')
4809 cant_be_null |= first_ch;
4811 switch (first_ch & 0x7f) {
4812 /* Highest bit in first_ch indicates that var is double-quoted */
4816 if (!G.global_argv[1])
4819 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
4820 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
4821 while (G.global_argv[i]) {
4822 n = expand_on_ifs(output, n, G.global_argv[i]);
4823 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
4824 if (G.global_argv[i++][0] && G.global_argv[i]) {
4825 /* this argv[] is not empty and not last:
4826 * put terminating NUL, start new word */
4827 o_addchr(output, '\0');
4828 debug_print_list("expand_vars_to_list[2]", output, n);
4829 n = o_save_ptr(output, n);
4830 debug_print_list("expand_vars_to_list[3]", output, n);
4834 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
4835 * and in this case should treat it like '$*' - see 'else...' below */
4836 if (first_ch == ('@'|0x80) /* quoted $@ */
4837 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
4840 o_addQstr(output, G.global_argv[i]);
4841 if (++i >= G.global_argc)
4843 o_addchr(output, '\0');
4844 debug_print_list("expand_vars_to_list[4]", output, n);
4845 n = o_save_ptr(output, n);
4847 } else { /* quoted $* (or v="$@" case): add as one word */
4849 o_addQstr(output, G.global_argv[i]);
4850 if (!G.global_argv[++i])
4853 o_addchr(output, G.ifs[0]);
4858 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
4859 /* "Empty variable", used to make "" etc to not disappear */
4861 cant_be_null = 0x80;
4863 #if ENABLE_HUSH_TICK
4864 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
4865 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
4867 /* Can't just stuff it into output o_string,
4868 * expanded result may need to be globbed
4869 * and $IFS-splitted */
4870 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
4871 G.last_exitcode = process_command_subs(&subst_result, arg);
4872 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
4873 val = subst_result.data;
4876 #if ENABLE_SH_MATH_SUPPORT
4877 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
4881 arg++; /* skip '+' */
4882 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
4883 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
4884 res = expand_and_evaluate_arith(arg, &errcode);
4887 const char *msg = "error in arithmetic";
4890 msg = "exponent less than 0";
4893 msg = "divide by 0";
4896 msg = "expression recursion loop detected";
4901 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
4902 sprintf(arith_buf, arith_t_fmt, res);
4908 val = expand_one_var(&to_be_freed, arg, &p);
4909 IF_HUSH_TICK(store_val:)
4910 if (!(first_ch & 0x80)) { /* unquoted $VAR */
4911 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
4912 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4913 if (val && val[0]) {
4914 n = expand_on_ifs(output, n, val);
4917 } else { /* quoted $VAR, val will be appended below */
4918 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
4919 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4923 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
4925 if (val && val[0]) {
4926 o_addQstr(output, val);
4930 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
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 && !(cant_be_null & 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, int do_unbackslash)
5001 char *argv[2], **list;
5003 debug_printf_expand("string_to_string<='%s'\n", str);
5004 /* This is generally an optimization, but it also
5005 * handles "", which otherwise trips over !list[0] check below.
5006 * (is this ever happens that we actually get str="" here?)
5008 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5009 //TODO: Can use on strings with \ too, just unbackslash() them?
5010 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5011 return xstrdup(str);
5014 argv[0] = (char*)str;
5016 list = expand_variables(argv, do_unbackslash
5017 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5018 : EXP_FLAG_SINGLEWORD
5021 if (!list[0] || list[1])
5022 bb_error_msg_and_die("BUG in varexp2");
5023 /* actually, just move string 2*sizeof(char*) bytes back */
5024 overlapping_strcpy((char*)list, list[0]);
5026 unbackslash((char*)list);
5027 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5031 /* Used for "eval" builtin */
5032 static char* expand_strvec_to_string(char **argv)
5036 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5037 /* Convert all NULs to spaces */
5042 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5043 bb_error_msg_and_die("BUG in varexp3");
5044 /* bash uses ' ' regardless of $IFS contents */
5049 overlapping_strcpy((char*)list, list[0]);
5050 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5054 static char **expand_assignments(char **argv, int count)
5059 G.expanded_assignments = p = NULL;
5060 /* Expand assignments into one string each */
5061 for (i = 0; i < count; i++) {
5062 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5064 G.expanded_assignments = NULL;
5071 void re_execute_shell(char ***to_free, const char *s,
5072 char *g_argv0, char **g_argv,
5073 char **builtin_argv) NORETURN;
5075 static void reset_traps_to_defaults(void)
5077 /* This function is always called in a child shell
5078 * after fork (not vfork, NOMMU doesn't use this function).
5083 /* Child shells are not interactive.
5084 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5085 * Testcase: (while :; do :; done) + ^Z should background.
5086 * Same goes for SIGTERM, SIGHUP, SIGINT.
5088 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
5089 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
5091 /* Switching off SPECIAL_INTERACTIVE_SIGS.
5092 * Stupid. It can be done with *single* &= op, but we can't use
5093 * the fact that G.blocked_set is implemented as a bitmask
5095 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
5099 /* Careful. Only if no trap or trap is not "" */
5100 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
5101 sigdelset(&G.blocked_set, sig);
5108 /* Our homegrown sig mask is saner to work with :) */
5109 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5111 /* Resetting all traps to default except empty ones */
5112 mask = G.non_DFL_mask;
5113 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
5114 if (!G.traps[sig] || !G.traps[sig][0])
5117 G.traps[sig] = NULL;
5118 /* There is no signal for 0 (EXIT) */
5121 /* There was a trap handler, we just removed it.
5122 * But if sig still has non-DFL handling,
5123 * we should not unblock the sig. */
5126 sigdelset(&G.blocked_set, sig);
5128 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5133 static void re_execute_shell(char ***to_free, const char *s,
5134 char *g_argv0, char **g_argv,
5135 char **builtin_argv) NORETURN;
5136 static void re_execute_shell(char ***to_free, const char *s,
5137 char *g_argv0, char **g_argv,
5138 char **builtin_argv)
5140 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5141 /* delims + 2 * (number of bytes in printed hex numbers) */
5142 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5143 char *heredoc_argv[4];
5144 struct variable *cur;
5145 # if ENABLE_HUSH_FUNCTIONS
5146 struct function *funcp;
5150 unsigned long long empty_trap_mask;
5152 if (!g_argv0) { /* heredoc */
5153 argv = heredoc_argv;
5154 argv[0] = (char *) G.argv0_for_re_execing;
5155 argv[1] = (char *) "-<";
5156 argv[2] = (char *) s;
5158 pp = &argv[3]; /* used as pointer to empty environment */
5164 if (pp) while (*pp++)
5167 empty_trap_mask = 0;
5170 for (sig = 1; sig < NSIG; sig++) {
5171 if (G.traps[sig] && !G.traps[sig][0])
5172 empty_trap_mask |= 1LL << sig;
5176 sprintf(param_buf, NOMMU_HACK_FMT
5177 , (unsigned) G.root_pid
5178 , (unsigned) G.root_ppid
5179 , (unsigned) G.last_bg_pid
5180 , (unsigned) G.last_exitcode
5183 IF_HUSH_LOOPS(, G.depth_of_loop)
5185 # undef NOMMU_HACK_FMT
5186 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5187 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5190 for (cur = G.top_var; cur; cur = cur->next) {
5191 if (!cur->flg_export || cur->flg_read_only)
5194 # if ENABLE_HUSH_FUNCTIONS
5195 for (funcp = G.top_func; funcp; funcp = funcp->next)
5201 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5202 *pp++ = (char *) G.argv0_for_re_execing;
5204 for (cur = G.top_var; cur; cur = cur->next) {
5205 if (strcmp(cur->varstr, hush_version_str) == 0)
5207 if (cur->flg_read_only) {
5208 *pp++ = (char *) "-R";
5209 *pp++ = cur->varstr;
5210 } else if (!cur->flg_export) {
5211 *pp++ = (char *) "-V";
5212 *pp++ = cur->varstr;
5215 # if ENABLE_HUSH_FUNCTIONS
5216 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5217 *pp++ = (char *) "-F";
5218 *pp++ = funcp->name;
5219 *pp++ = funcp->body_as_string;
5222 /* We can pass activated traps here. Say, -Tnn:trap_string
5224 * However, POSIX says that subshells reset signals with traps
5226 * I tested bash-3.2 and it not only does that with true subshells
5227 * of the form ( list ), but with any forked children shells.
5228 * I set trap "echo W" WINCH; and then tried:
5230 * { echo 1; sleep 20; echo 2; } &
5231 * while true; do echo 1; sleep 20; echo 2; break; done &
5232 * true | { echo 1; sleep 20; echo 2; } | cat
5234 * In all these cases sending SIGWINCH to the child shell
5235 * did not run the trap. If I add trap "echo V" WINCH;
5236 * _inside_ group (just before echo 1), it works.
5238 * I conclude it means we don't need to pass active traps here.
5239 * Even if we would use signal handlers instead of signal masking
5240 * in order to implement trap handling,
5241 * exec syscall below resets signals to SIG_DFL for us.
5243 *pp++ = (char *) "-c";
5246 while (*++builtin_argv)
5247 *pp++ = *builtin_argv;
5248 *pp++ = (char *) "";
5253 /* *pp = NULL; - is already there */
5257 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5258 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5259 execve(bb_busybox_exec_path, argv, pp);
5260 /* Fallback. Useful for init=/bin/hush usage etc */
5261 if (argv[0][0] == '/')
5262 execve(argv[0], argv, pp);
5263 xfunc_error_retval = 127;
5264 bb_error_msg_and_die("can't re-execute the shell");
5266 #endif /* !BB_MMU */
5269 static int run_and_free_list(struct pipe *pi);
5271 /* Executing from string: eval, sh -c '...'
5272 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5273 * end_trigger controls how often we stop parsing
5274 * NUL: parse all, execute, return
5275 * ';': parse till ';' or newline, execute, repeat till EOF
5277 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5279 /* Why we need empty flag?
5280 * An obscure corner case "false; ``; echo $?":
5281 * empty command in `` should still set $? to 0.
5282 * But we can't just set $? to 0 at the start,
5283 * this breaks "false; echo `echo $?`" case.
5287 struct pipe *pipe_list;
5289 pipe_list = parse_stream(NULL, inp, end_trigger);
5290 if (!pipe_list) { /* EOF */
5292 G.last_exitcode = 0;
5295 debug_print_tree(pipe_list, 0);
5296 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5297 run_and_free_list(pipe_list);
5302 static void parse_and_run_string(const char *s)
5304 struct in_str input;
5305 setup_string_in_str(&input, s);
5306 parse_and_run_stream(&input, '\0');
5309 static void parse_and_run_file(FILE *f)
5311 struct in_str input;
5312 setup_file_in_str(&input, f);
5313 parse_and_run_stream(&input, ';');
5316 #if ENABLE_HUSH_TICK
5317 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5322 char **to_free = NULL;
5326 pid = BB_MMU ? xfork() : xvfork();
5327 if (pid == 0) { /* child */
5328 disable_restore_tty_pgrp_on_exit();
5329 /* Process substitution is not considered to be usual
5330 * 'command execution'.
5331 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5338 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5339 close(channel[0]); /* NB: close _first_, then move fd! */
5340 xmove_fd(channel[1], 1);
5341 /* Prevent it from trying to handle ctrl-z etc */
5342 IF_HUSH_JOB(G.run_list_level = 1;)
5343 /* Awful hack for `trap` or $(trap).
5345 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5346 * contains an example where "trap" is executed in a subshell:
5348 * save_traps=$(trap)
5350 * eval "$save_traps"
5352 * Standard does not say that "trap" in subshell shall print
5353 * parent shell's traps. It only says that its output
5354 * must have suitable form, but then, in the above example
5355 * (which is not supposed to be normative), it implies that.
5357 * bash (and probably other shell) does implement it
5358 * (traps are reset to defaults, but "trap" still shows them),
5359 * but as a result, "trap" logic is hopelessly messed up:
5362 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5363 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5364 * # true | trap <--- trap is in subshell - no output (ditto)
5365 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5366 * trap -- 'echo Ho' SIGWINCH
5367 * # echo `(trap)` <--- in subshell in subshell - output
5368 * trap -- 'echo Ho' SIGWINCH
5369 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5370 * trap -- 'echo Ho' SIGWINCH
5372 * The rules when to forget and when to not forget traps
5373 * get really complex and nonsensical.
5375 * Our solution: ONLY bare $(trap) or `trap` is special.
5377 s = skip_whitespace(s);
5378 if (strncmp(s, "trap", 4) == 0
5379 && skip_whitespace(s + 4)[0] == '\0'
5381 static const char *const argv[] = { NULL, NULL };
5382 builtin_trap((char**)argv);
5383 exit(0); /* not _exit() - we need to fflush */
5386 reset_traps_to_defaults();
5387 parse_and_run_string(s);
5388 _exit(G.last_exitcode);
5390 /* We re-execute after vfork on NOMMU. This makes this script safe:
5391 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5392 * huge=`cat BIG` # was blocking here forever
5395 re_execute_shell(&to_free,
5405 # if ENABLE_HUSH_FAST
5407 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5408 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5409 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5411 enable_restore_tty_pgrp_on_exit();
5416 close_on_exec_on(channel[0]);
5417 return xfdopen_for_read(channel[0]);
5420 /* Return code is exit status of the process that is run. */
5421 static int process_command_subs(o_string *dest, const char *s)
5424 struct in_str pipe_str;
5426 int status, ch, eol_cnt;
5428 fp = generate_stream_from_string(s, &pid);
5430 /* Now send results of command back into original context */
5431 setup_file_in_str(&pipe_str, fp);
5433 while ((ch = i_getch(&pipe_str)) != EOF) {
5439 o_addchr(dest, '\n');
5442 o_addQchr(dest, ch);
5445 debug_printf("done reading from `cmd` pipe, closing it\n");
5447 /* We need to extract exitcode. Test case
5448 * "true; echo `sleep 1; false` $?"
5450 safe_waitpid(pid, &status, 0);
5451 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5452 return WEXITSTATUS(status);
5454 #endif /* ENABLE_HUSH_TICK */
5457 static void setup_heredoc(struct redir_struct *redir)
5459 struct fd_pair pair;
5462 /* the _body_ of heredoc (misleading field name) */
5463 const char *heredoc = redir->rd_filename;
5470 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5471 expanded = expand_pseudo_dquoted(heredoc, /*dquoted:*/ 1, /*unbackslash:*/ 1);
5475 len = strlen(heredoc);
5477 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5479 xmove_fd(pair.rd, redir->rd_fd);
5481 /* Try writing without forking. Newer kernels have
5482 * dynamically growing pipes. Must use non-blocking write! */
5485 written = write(pair.wr, heredoc, len);
5496 ndelay_off(pair.wr);
5498 /* Okay, pipe buffer was not big enough */
5499 /* Note: we must not create a stray child (bastard? :)
5500 * for the unsuspecting parent process. Child creates a grandchild
5501 * and exits before parent execs the process which consumes heredoc
5502 * (that exec happens after we return from this function) */
5509 disable_restore_tty_pgrp_on_exit();
5510 pid = BB_MMU ? xfork() : xvfork();
5514 close(redir->rd_fd); /* read side of the pipe */
5516 full_write(pair.wr, heredoc, len); /* may loop or block */
5519 /* Delegate blocking writes to another process */
5520 xmove_fd(pair.wr, STDOUT_FILENO);
5521 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
5525 #if ENABLE_HUSH_FAST
5527 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5529 enable_restore_tty_pgrp_on_exit();
5535 wait(NULL); /* wait till child has died */
5538 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
5539 * and stderr if they are redirected. */
5540 static int setup_redirects(struct command *prog, int squirrel[])
5543 struct redir_struct *redir;
5545 for (redir = prog->redirects; redir; redir = redir->next) {
5546 if (redir->rd_type == REDIRECT_HEREDOC2) {
5547 /* rd_fd<<HERE case */
5548 if (squirrel && redir->rd_fd < 3
5549 && squirrel[redir->rd_fd] < 0
5551 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5553 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
5555 debug_printf_parse("set heredoc '%s'\n",
5556 redir->rd_filename);
5557 setup_heredoc(redir);
5561 if (redir->rd_dup == REDIRFD_TO_FILE) {
5562 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
5564 if (redir->rd_filename == NULL) {
5565 /* Something went wrong in the parse.
5566 * Pretend it didn't happen */
5567 bb_error_msg("bug in redirect parse");
5570 mode = redir_table[redir->rd_type].mode;
5571 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
5572 openfd = open_or_warn(p, mode);
5575 /* this could get lost if stderr has been redirected, but
5576 * bash and ash both lose it as well (though zsh doesn't!) */
5577 //what the above comment tries to say?
5581 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
5582 openfd = redir->rd_dup;
5585 if (openfd != redir->rd_fd) {
5586 if (squirrel && redir->rd_fd < 3
5587 && squirrel[redir->rd_fd] < 0
5589 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5591 if (openfd == REDIRFD_CLOSE) {
5592 /* "n>-" means "close me" */
5593 close(redir->rd_fd);
5595 xdup2(openfd, redir->rd_fd);
5596 if (redir->rd_dup == REDIRFD_TO_FILE)
5604 static void restore_redirects(int squirrel[])
5607 for (i = 0; i < 3; i++) {
5610 /* We simply die on error */
5616 static char *find_in_path(const char *arg)
5619 const char *PATH = get_local_var_value("PATH");
5625 const char *end = strchrnul(PATH, ':');
5626 int sz = end - PATH; /* must be int! */
5630 ret = xasprintf("%.*s/%s", sz, PATH, arg);
5632 /* We have xxx::yyyy in $PATH,
5633 * it means "use current dir" */
5636 if (access(ret, F_OK) == 0)
5649 static const struct built_in_command *find_builtin_helper(const char *name,
5650 const struct built_in_command *x,
5651 const struct built_in_command *end)
5654 if (strcmp(name, x->b_cmd) != 0) {
5658 debug_printf_exec("found builtin '%s'\n", name);
5663 static const struct built_in_command *find_builtin1(const char *name)
5665 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
5667 static const struct built_in_command *find_builtin(const char *name)
5669 const struct built_in_command *x = find_builtin1(name);
5672 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
5675 #if ENABLE_HUSH_FUNCTIONS
5676 static struct function **find_function_slot(const char *name)
5678 struct function **funcpp = &G.top_func;
5680 if (strcmp(name, (*funcpp)->name) == 0) {
5683 funcpp = &(*funcpp)->next;
5688 static const struct function *find_function(const char *name)
5690 const struct function *funcp = *find_function_slot(name);
5692 debug_printf_exec("found function '%s'\n", name);
5696 /* Note: takes ownership on name ptr */
5697 static struct function *new_function(char *name)
5699 struct function **funcpp = find_function_slot(name);
5700 struct function *funcp = *funcpp;
5702 if (funcp != NULL) {
5703 struct command *cmd = funcp->parent_cmd;
5704 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
5706 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
5708 /* Note: if !funcp->body, do not free body_as_string!
5709 * This is a special case of "-F name body" function:
5710 * body_as_string was not malloced! */
5712 free_pipe_list(funcp->body);
5714 free(funcp->body_as_string);
5718 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
5719 cmd->argv[0] = funcp->name;
5720 cmd->group = funcp->body;
5722 cmd->group_as_string = funcp->body_as_string;
5726 debug_printf_exec("remembering new function '%s'\n", name);
5727 funcp = *funcpp = xzalloc(sizeof(*funcp));
5728 /*funcp->next = NULL;*/
5735 static void unset_func(const char *name)
5737 struct function **funcpp = find_function_slot(name);
5738 struct function *funcp = *funcpp;
5740 if (funcp != NULL) {
5741 debug_printf_exec("freeing function '%s'\n", funcp->name);
5742 *funcpp = funcp->next;
5743 /* funcp is unlinked now, deleting it.
5744 * Note: if !funcp->body, the function was created by
5745 * "-F name body", do not free ->body_as_string
5746 * and ->name as they were not malloced. */
5748 free_pipe_list(funcp->body);
5751 free(funcp->body_as_string);
5759 #define exec_function(to_free, funcp, argv) \
5760 exec_function(funcp, argv)
5762 static void exec_function(char ***to_free,
5763 const struct function *funcp,
5764 char **argv) NORETURN;
5765 static void exec_function(char ***to_free,
5766 const struct function *funcp,
5772 argv[0] = G.global_argv[0];
5773 G.global_argv = argv;
5777 /* On MMU, funcp->body is always non-NULL */
5778 n = run_list(funcp->body);
5782 re_execute_shell(to_free,
5783 funcp->body_as_string,
5790 static int run_function(const struct function *funcp, char **argv)
5796 save_and_replace_G_args(&sv, argv);
5798 /* "we are in function, ok to use return" */
5799 sv_flg = G.flag_return_in_progress;
5800 G.flag_return_in_progress = -1;
5801 # if ENABLE_HUSH_LOCAL
5802 G.func_nest_level++;
5805 /* On MMU, funcp->body is always non-NULL */
5808 /* Function defined by -F */
5809 parse_and_run_string(funcp->body_as_string);
5810 rc = G.last_exitcode;
5814 rc = run_list(funcp->body);
5817 # if ENABLE_HUSH_LOCAL
5819 struct variable *var;
5820 struct variable **var_pp;
5822 var_pp = &G.top_var;
5823 while ((var = *var_pp) != NULL) {
5824 if (var->func_nest_level < G.func_nest_level) {
5825 var_pp = &var->next;
5829 if (var->flg_export)
5830 bb_unsetenv(var->varstr);
5831 /* Remove from global list */
5832 *var_pp = var->next;
5838 G.func_nest_level--;
5841 G.flag_return_in_progress = sv_flg;
5843 restore_G_args(&sv, argv);
5847 #endif /* ENABLE_HUSH_FUNCTIONS */
5851 #define exec_builtin(to_free, x, argv) \
5852 exec_builtin(x, argv)
5854 #define exec_builtin(to_free, x, argv) \
5855 exec_builtin(to_free, argv)
5857 static void exec_builtin(char ***to_free,
5858 const struct built_in_command *x,
5859 char **argv) NORETURN;
5860 static void exec_builtin(char ***to_free,
5861 const struct built_in_command *x,
5865 int rcode = x->b_function(argv);
5869 /* On NOMMU, we must never block!
5870 * Example: { sleep 99 | read line; } & echo Ok
5872 re_execute_shell(to_free,
5881 static void execvp_or_die(char **argv) NORETURN;
5882 static void execvp_or_die(char **argv)
5884 debug_printf_exec("execing '%s'\n", argv[0]);
5885 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5886 execvp(argv[0], argv);
5887 bb_perror_msg("can't execute '%s'", argv[0]);
5888 _exit(127); /* bash compat */
5891 #if ENABLE_HUSH_MODE_X
5892 static void dump_cmd_in_x_mode(char **argv)
5894 if (G_x_mode && argv) {
5895 /* We want to output the line in one write op */
5903 len += strlen(argv[n++]) + 1;
5909 p += sprintf(p, " %s", argv[n++]);
5917 # define dump_cmd_in_x_mode(argv) ((void)0)
5921 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
5922 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
5923 #define pseudo_exec(nommu_save, command, argv_expanded) \
5924 pseudo_exec(command, argv_expanded)
5927 /* Called after [v]fork() in run_pipe, or from builtin_exec.
5929 * Don't exit() here. If you don't exec, use _exit instead.
5930 * The at_exit handlers apparently confuse the calling process,
5931 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
5932 static void pseudo_exec_argv(nommu_save_t *nommu_save,
5933 char **argv, int assignment_cnt,
5934 char **argv_expanded) NORETURN;
5935 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
5936 char **argv, int assignment_cnt,
5937 char **argv_expanded)
5941 new_env = expand_assignments(argv, assignment_cnt);
5942 dump_cmd_in_x_mode(new_env);
5944 if (!argv[assignment_cnt]) {
5945 /* Case when we are here: ... | var=val | ...
5946 * (note that we do not exit early, i.e., do not optimize out
5947 * expand_assignments(): think about ... | var=`sleep 1` | ...
5949 free_strings(new_env);
5950 _exit(EXIT_SUCCESS);
5954 set_vars_and_save_old(new_env);
5955 free(new_env); /* optional */
5956 /* we can also destroy set_vars_and_save_old's return value,
5959 nommu_save->new_env = new_env;
5960 nommu_save->old_vars = set_vars_and_save_old(new_env);
5963 if (argv_expanded) {
5964 argv = argv_expanded;
5966 argv = expand_strvec_to_strvec(argv + assignment_cnt);
5968 nommu_save->argv = argv;
5971 dump_cmd_in_x_mode(argv);
5973 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
5974 if (strchr(argv[0], '/') != NULL)
5978 /* Check if the command matches any of the builtins.
5979 * Depending on context, this might be redundant. But it's
5980 * easier to waste a few CPU cycles than it is to figure out
5981 * if this is one of those cases.
5984 /* On NOMMU, it is more expensive to re-execute shell
5985 * just in order to run echo or test builtin.
5986 * It's better to skip it here and run corresponding
5987 * non-builtin later. */
5988 const struct built_in_command *x;
5989 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
5991 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
5994 #if ENABLE_HUSH_FUNCTIONS
5995 /* Check if the command matches any functions */
5997 const struct function *funcp = find_function(argv[0]);
5999 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6004 #if ENABLE_FEATURE_SH_STANDALONE
6005 /* Check if the command matches any busybox applets */
6007 int a = find_applet_by_name(argv[0]);
6009 # if BB_MMU /* see above why on NOMMU it is not allowed */
6010 if (APPLET_IS_NOEXEC(a)) {
6011 debug_printf_exec("running applet '%s'\n", argv[0]);
6012 run_applet_no_and_exit(a, argv);
6015 /* Re-exec ourselves */
6016 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6017 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6018 execv(bb_busybox_exec_path, argv);
6019 /* If they called chroot or otherwise made the binary no longer
6020 * executable, fall through */
6025 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6028 execvp_or_die(argv);
6031 /* Called after [v]fork() in run_pipe
6033 static void pseudo_exec(nommu_save_t *nommu_save,
6034 struct command *command,
6035 char **argv_expanded) NORETURN;
6036 static void pseudo_exec(nommu_save_t *nommu_save,
6037 struct command *command,
6038 char **argv_expanded)
6040 if (command->argv) {
6041 pseudo_exec_argv(nommu_save, command->argv,
6042 command->assignment_cnt, argv_expanded);
6045 if (command->group) {
6046 /* Cases when we are here:
6049 * ... | ( list ) | ...
6050 * ... | { list } | ...
6054 debug_printf_exec("pseudo_exec: run_list\n");
6055 reset_traps_to_defaults();
6056 rcode = run_list(command->group);
6057 /* OK to leak memory by not calling free_pipe_list,
6058 * since this process is about to exit */
6061 re_execute_shell(&nommu_save->argv_from_re_execing,
6062 command->group_as_string,
6069 /* Case when we are here: ... | >file */
6070 debug_printf_exec("pseudo_exec'ed null command\n");
6071 _exit(EXIT_SUCCESS);
6075 static const char *get_cmdtext(struct pipe *pi)
6081 /* This is subtle. ->cmdtext is created only on first backgrounding.
6082 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6083 * On subsequent bg argv is trashed, but we won't use it */
6086 argv = pi->cmds[0].argv;
6087 if (!argv || !argv[0]) {
6088 pi->cmdtext = xzalloc(1);
6094 len += strlen(*argv) + 1;
6098 argv = pi->cmds[0].argv;
6100 len = strlen(*argv);
6101 memcpy(p, *argv, len);
6109 static void insert_bg_job(struct pipe *pi)
6111 struct pipe *job, **jobp;
6114 /* Linear search for the ID of the job to use */
6116 for (job = G.job_list; job; job = job->next)
6117 if (job->jobid >= pi->jobid)
6118 pi->jobid = job->jobid + 1;
6120 /* Add job to the list of running jobs */
6122 while ((job = *jobp) != NULL)
6124 job = *jobp = xmalloc(sizeof(*job));
6126 *job = *pi; /* physical copy */
6128 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6129 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6130 for (i = 0; i < pi->num_cmds; i++) {
6131 job->cmds[i].pid = pi->cmds[i].pid;
6132 /* all other fields are not used and stay zero */
6134 job->cmdtext = xstrdup(get_cmdtext(pi));
6136 if (G_interactive_fd)
6137 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6138 G.last_jobid = job->jobid;
6141 static void remove_bg_job(struct pipe *pi)
6143 struct pipe *prev_pipe;
6145 if (pi == G.job_list) {
6146 G.job_list = pi->next;
6148 prev_pipe = G.job_list;
6149 while (prev_pipe->next != pi)
6150 prev_pipe = prev_pipe->next;
6151 prev_pipe->next = pi->next;
6154 G.last_jobid = G.job_list->jobid;
6159 /* Remove a backgrounded job */
6160 static void delete_finished_bg_job(struct pipe *pi)
6167 /* Check to see if any processes have exited -- if they
6168 * have, figure out why and see if a job has completed */
6169 static int checkjobs(struct pipe *fg_pipe)
6179 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6181 attributes = WUNTRACED;
6182 if (fg_pipe == NULL)
6183 attributes |= WNOHANG;
6186 #if ENABLE_HUSH_FAST
6187 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6188 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6189 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6190 /* There was neither fork nor SIGCHLD since last waitpid */
6191 /* Avoid doing waitpid syscall if possible */
6192 if (!G.we_have_children) {
6196 if (fg_pipe == NULL) { /* is WNOHANG set? */
6197 /* We have children, but they did not exit
6198 * or stop yet (we saw no SIGCHLD) */
6201 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6205 /* Do we do this right?
6206 * bash-3.00# sleep 20 | false
6208 * [3]+ Stopped sleep 20 | false
6209 * bash-3.00# echo $?
6210 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6211 * [hush 1.14.0: yes we do it right]
6218 #if ENABLE_HUSH_FAST
6219 i = G.count_SIGCHLD;
6221 childpid = waitpid(-1, &status, attributes);
6222 if (childpid <= 0) {
6223 if (childpid && errno != ECHILD)
6224 bb_perror_msg("waitpid");
6225 #if ENABLE_HUSH_FAST
6226 else { /* Until next SIGCHLD, waitpid's are useless */
6227 G.we_have_children = (childpid == 0);
6228 G.handled_SIGCHLD = i;
6229 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6234 dead = WIFEXITED(status) || WIFSIGNALED(status);
6237 if (WIFSTOPPED(status))
6238 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6239 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6240 if (WIFSIGNALED(status))
6241 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6242 childpid, WTERMSIG(status), WEXITSTATUS(status));
6243 if (WIFEXITED(status))
6244 debug_printf_jobs("pid %d exited, exitcode %d\n",
6245 childpid, WEXITSTATUS(status));
6247 /* Were we asked to wait for fg pipe? */
6249 for (i = 0; i < fg_pipe->num_cmds; i++) {
6250 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6251 if (fg_pipe->cmds[i].pid != childpid)
6254 fg_pipe->cmds[i].pid = 0;
6255 fg_pipe->alive_cmds--;
6256 if (i == fg_pipe->num_cmds - 1) {
6257 /* last process gives overall exitstatus */
6258 rcode = WEXITSTATUS(status);
6259 /* bash prints killer signal's name for *last*
6260 * process in pipe (prints just newline for SIGINT).
6261 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6263 if (WIFSIGNALED(status)) {
6264 int sig = WTERMSIG(status);
6265 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
6266 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6267 * Maybe we need to use sig | 128? */
6270 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6273 fg_pipe->cmds[i].is_stopped = 1;
6274 fg_pipe->stopped_cmds++;
6276 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6277 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6278 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
6279 /* All processes in fg pipe have exited or stopped */
6280 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6281 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6282 * and "killall -STOP cat" */
6283 if (G_interactive_fd) {
6285 if (fg_pipe->alive_cmds)
6286 insert_bg_job(fg_pipe);
6290 if (!fg_pipe->alive_cmds)
6293 /* There are still running processes in the fg pipe */
6294 goto wait_more; /* do waitpid again */
6296 /* it wasnt fg_pipe, look for process in bg pipes */
6300 /* We asked to wait for bg or orphaned children */
6301 /* No need to remember exitcode in this case */
6302 for (pi = G.job_list; pi; pi = pi->next) {
6303 for (i = 0; i < pi->num_cmds; i++) {
6304 if (pi->cmds[i].pid == childpid)
6305 goto found_pi_and_prognum;
6308 /* Happens when shell is used as init process (init=/bin/sh) */
6309 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6310 continue; /* do waitpid again */
6312 found_pi_and_prognum:
6315 pi->cmds[i].pid = 0;
6317 if (!pi->alive_cmds) {
6318 if (G_interactive_fd)
6319 printf(JOB_STATUS_FORMAT, pi->jobid,
6320 "Done", pi->cmdtext);
6321 delete_finished_bg_job(pi);
6325 pi->cmds[i].is_stopped = 1;
6329 } /* while (waitpid succeeds)... */
6335 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6338 int rcode = checkjobs(fg_pipe);
6339 if (G_saved_tty_pgrp) {
6340 /* Job finished, move the shell to the foreground */
6341 p = getpgrp(); /* our process group id */
6342 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6343 tcsetpgrp(G_interactive_fd, p);
6349 /* Start all the jobs, but don't wait for anything to finish.
6352 * Return code is normally -1, when the caller has to wait for children
6353 * to finish to determine the exit status of the pipe. If the pipe
6354 * is a simple builtin command, however, the action is done by the
6355 * time run_pipe returns, and the exit code is provided as the
6358 * Returns -1 only if started some children. IOW: we have to
6359 * mask out retvals of builtins etc with 0xff!
6361 * The only case when we do not need to [v]fork is when the pipe
6362 * is single, non-backgrounded, non-subshell command. Examples:
6363 * cmd ; ... { list } ; ...
6364 * cmd && ... { list } && ...
6365 * cmd || ... { list } || ...
6366 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
6367 * or (if SH_STANDALONE) an applet, and we can run the { list }
6368 * with run_list. If it isn't one of these, we fork and exec cmd.
6370 * Cases when we must fork:
6371 * non-single: cmd | cmd
6372 * backgrounded: cmd & { list } &
6373 * subshell: ( list ) [&]
6375 #if !ENABLE_HUSH_MODE_X
6376 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, char argv_expanded) \
6377 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6379 static int redirect_and_varexp_helper(char ***new_env_p,
6380 struct variable **old_vars_p,
6381 struct command *command,
6383 char **argv_expanded)
6385 /* setup_redirects acts on file descriptors, not FILEs.
6386 * This is perfect for work that comes after exec().
6387 * Is it really safe for inline use? Experimentally,
6388 * things seem to work. */
6389 int rcode = setup_redirects(command, squirrel);
6391 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6392 *new_env_p = new_env;
6393 dump_cmd_in_x_mode(new_env);
6394 dump_cmd_in_x_mode(argv_expanded);
6396 *old_vars_p = set_vars_and_save_old(new_env);
6400 static NOINLINE int run_pipe(struct pipe *pi)
6402 static const char *const null_ptr = NULL;
6406 struct command *command;
6407 char **argv_expanded;
6409 /* it is not always needed, but we aim to smaller code */
6410 int squirrel[] = { -1, -1, -1 };
6413 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6416 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6417 * Result should be 3 lines: q w e, qwe, q w e
6419 G.ifs = get_local_var_value("IFS");
6423 IF_HUSH_JOB(pi->pgrp = -1;)
6424 pi->stopped_cmds = 0;
6425 command = &pi->cmds[0];
6426 argv_expanded = NULL;
6428 if (pi->num_cmds != 1
6429 || pi->followup == PIPE_BG
6430 || command->cmd_type == CMD_SUBSHELL
6437 debug_printf_exec(": group:%p argv:'%s'\n",
6438 command->group, command->argv ? command->argv[0] : "NONE");
6440 if (command->group) {
6441 #if ENABLE_HUSH_FUNCTIONS
6442 if (command->cmd_type == CMD_FUNCDEF) {
6443 /* "executing" func () { list } */
6444 struct function *funcp;
6446 funcp = new_function(command->argv[0]);
6447 /* funcp->name is already set to argv[0] */
6448 funcp->body = command->group;
6450 funcp->body_as_string = command->group_as_string;
6451 command->group_as_string = NULL;
6453 command->group = NULL;
6454 command->argv[0] = NULL;
6455 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6456 funcp->parent_cmd = command;
6457 command->child_func = funcp;
6459 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6461 return EXIT_SUCCESS;
6465 debug_printf("non-subshell group\n");
6466 rcode = 1; /* exitcode if redir failed */
6467 if (setup_redirects(command, squirrel) == 0) {
6468 debug_printf_exec(": run_list\n");
6469 rcode = run_list(command->group) & 0xff;
6471 restore_redirects(squirrel);
6472 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6474 debug_printf_exec("run_pipe: return %d\n", rcode);
6478 argv = command->argv ? command->argv : (char **) &null_ptr;
6480 const struct built_in_command *x;
6481 #if ENABLE_HUSH_FUNCTIONS
6482 const struct function *funcp;
6486 char **new_env = NULL;
6487 struct variable *old_vars = NULL;
6489 if (argv[command->assignment_cnt] == NULL) {
6490 /* Assignments, but no command */
6491 /* Ensure redirects take effect (that is, create files).
6492 * Try "a=t >file" */
6493 #if 0 /* A few cases in testsuite fail with this code. FIXME */
6494 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
6495 /* Set shell variables */
6499 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6500 /* Do we need to flag set_local_var() errors?
6501 * "assignment to readonly var" and "putenv error"
6506 /* Redirect error sets $? to 1. Otherwise,
6507 * if evaluating assignment value set $?, retain it.
6508 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6510 rcode = G.last_exitcode;
6511 /* Exit, _skipping_ variable restoring code: */
6512 goto clean_up_and_ret0;
6514 #else /* Older, bigger, but more correct code */
6516 rcode = setup_redirects(command, squirrel);
6517 restore_redirects(squirrel);
6518 /* Set shell variables */
6520 bb_putchar_stderr('+');
6522 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
6524 fprintf(stderr, " %s", p);
6525 debug_printf_exec("set shell var:'%s'->'%s'\n",
6527 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6528 /* Do we need to flag set_local_var() errors?
6529 * "assignment to readonly var" and "putenv error"
6534 bb_putchar_stderr('\n');
6535 /* Redirect error sets $? to 1. Otherwise,
6536 * if evaluating assignment value set $?, retain it.
6537 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6539 rcode = G.last_exitcode;
6540 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6542 debug_printf_exec("run_pipe: return %d\n", rcode);
6547 /* Expand the rest into (possibly) many strings each */
6549 #if ENABLE_HUSH_BASH_COMPAT
6550 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
6551 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
6555 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
6558 /* if someone gives us an empty string: `cmd with empty output` */
6559 if (!argv_expanded[0]) {
6560 free(argv_expanded);
6562 return G.last_exitcode;
6565 x = find_builtin(argv_expanded[0]);
6566 #if ENABLE_HUSH_FUNCTIONS
6569 funcp = find_function(argv_expanded[0]);
6573 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
6574 debug_printf("exec with redirects only\n");
6575 rcode = setup_redirects(command, NULL);
6576 goto clean_up_and_ret1;
6579 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6582 debug_printf_exec(": builtin '%s' '%s'...\n",
6583 x->b_cmd, argv_expanded[1]);
6584 rcode = x->b_function(argv_expanded) & 0xff;
6587 #if ENABLE_HUSH_FUNCTIONS
6589 # if ENABLE_HUSH_LOCAL
6590 struct variable **sv;
6591 sv = G.shadowed_vars_pp;
6592 G.shadowed_vars_pp = &old_vars;
6594 debug_printf_exec(": function '%s' '%s'...\n",
6595 funcp->name, argv_expanded[1]);
6596 rcode = run_function(funcp, argv_expanded) & 0xff;
6597 # if ENABLE_HUSH_LOCAL
6598 G.shadowed_vars_pp = sv;
6604 unset_vars(new_env);
6606 /* clean_up_and_ret0: */
6607 restore_redirects(squirrel);
6609 free(argv_expanded);
6610 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6612 debug_printf_exec("run_pipe return %d\n", rcode);
6616 if (ENABLE_FEATURE_SH_STANDALONE) {
6617 int n = find_applet_by_name(argv_expanded[0]);
6618 if (n >= 0 && APPLET_IS_NOFORK(n)) {
6619 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6621 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
6622 argv_expanded[0], argv_expanded[1]);
6623 rcode = run_nofork_applet(n, argv_expanded);
6625 goto clean_up_and_ret;
6628 /* It is neither builtin nor applet. We must fork. */
6632 /* NB: argv_expanded may already be created, and that
6633 * might include `cmd` runs! Do not rerun it! We *must*
6634 * use argv_expanded if it's non-NULL */
6636 /* Going to fork a child per each pipe member */
6641 while (cmd_no < pi->num_cmds) {
6642 struct fd_pair pipefds;
6644 volatile nommu_save_t nommu_save;
6645 nommu_save.new_env = NULL;
6646 nommu_save.old_vars = NULL;
6647 nommu_save.argv = NULL;
6648 nommu_save.argv_from_re_execing = NULL;
6650 command = &pi->cmds[cmd_no];
6652 if (command->argv) {
6653 debug_printf_exec(": pipe member '%s' '%s'...\n",
6654 command->argv[0], command->argv[1]);
6656 debug_printf_exec(": pipe member with no argv\n");
6659 /* pipes are inserted between pairs of commands */
6662 if (cmd_no < pi->num_cmds)
6663 xpiped_pair(pipefds);
6665 command->pid = BB_MMU ? fork() : vfork();
6666 if (!command->pid) { /* child */
6668 disable_restore_tty_pgrp_on_exit();
6669 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6671 /* Every child adds itself to new process group
6672 * with pgid == pid_of_first_child_in_pipe */
6673 if (G.run_list_level == 1 && G_interactive_fd) {
6676 if (pgrp < 0) /* true for 1st process only */
6678 if (setpgid(0, pgrp) == 0
6679 && pi->followup != PIPE_BG
6680 && G_saved_tty_pgrp /* we have ctty */
6682 /* We do it in *every* child, not just first,
6684 tcsetpgrp(G_interactive_fd, pgrp);
6688 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
6689 /* 1st cmd in backgrounded pipe
6690 * should have its stdin /dev/null'ed */
6692 if (open(bb_dev_null, O_RDONLY))
6693 xopen("/", O_RDONLY);
6695 xmove_fd(next_infd, 0);
6697 xmove_fd(pipefds.wr, 1);
6700 /* Like bash, explicit redirects override pipes,
6701 * and the pipe fd is available for dup'ing. */
6702 if (setup_redirects(command, NULL))
6705 /* Restore default handlers just prior to exec */
6706 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
6708 /* Stores to nommu_save list of env vars putenv'ed
6709 * (NOMMU, on MMU we don't need that) */
6710 /* cast away volatility... */
6711 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
6712 /* pseudo_exec() does not return */
6715 /* parent or error */
6716 #if ENABLE_HUSH_FAST
6718 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6720 enable_restore_tty_pgrp_on_exit();
6722 /* Clean up after vforked child */
6723 free(nommu_save.argv);
6724 free(nommu_save.argv_from_re_execing);
6725 unset_vars(nommu_save.new_env);
6726 add_vars(nommu_save.old_vars);
6728 free(argv_expanded);
6729 argv_expanded = NULL;
6730 if (command->pid < 0) { /* [v]fork failed */
6731 /* Clearly indicate, was it fork or vfork */
6732 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
6736 /* Second and next children need to know pid of first one */
6738 pi->pgrp = command->pid;
6744 if (cmd_no < pi->num_cmds)
6746 /* Pass read (output) pipe end to next iteration */
6747 next_infd = pipefds.rd;
6750 if (!pi->alive_cmds) {
6752 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
6757 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
6761 #ifndef debug_print_tree
6762 static void debug_print_tree(struct pipe *pi, int lvl)
6764 static const char *const PIPE[] = {
6770 static const char *RES[] = {
6771 [RES_NONE ] = "NONE" ,
6774 [RES_THEN ] = "THEN" ,
6775 [RES_ELIF ] = "ELIF" ,
6776 [RES_ELSE ] = "ELSE" ,
6779 # if ENABLE_HUSH_LOOPS
6780 [RES_FOR ] = "FOR" ,
6781 [RES_WHILE] = "WHILE",
6782 [RES_UNTIL] = "UNTIL",
6784 [RES_DONE ] = "DONE" ,
6786 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
6789 # if ENABLE_HUSH_CASE
6790 [RES_CASE ] = "CASE" ,
6791 [RES_CASE_IN ] = "CASE_IN" ,
6792 [RES_MATCH] = "MATCH",
6793 [RES_CASE_BODY] = "CASE_BODY",
6794 [RES_ESAC ] = "ESAC" ,
6796 [RES_XXXX ] = "XXXX" ,
6797 [RES_SNTX ] = "SNTX" ,
6799 static const char *const CMDTYPE[] = {
6803 # if ENABLE_HUSH_FUNCTIONS
6812 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
6813 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
6815 while (prn < pi->num_cmds) {
6816 struct command *command = &pi->cmds[prn];
6817 char **argv = command->argv;
6819 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
6821 command->assignment_cnt);
6822 if (command->group) {
6823 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
6824 CMDTYPE[command->cmd_type],
6827 , " group_as_string:", command->group_as_string
6832 debug_print_tree(command->group, lvl+1);
6836 if (argv) while (*argv) {
6837 fprintf(stderr, " '%s'", *argv);
6840 fprintf(stderr, "\n");
6847 #endif /* debug_print_tree */
6849 /* NB: called by pseudo_exec, and therefore must not modify any
6850 * global data until exec/_exit (we can be a child after vfork!) */
6851 static int run_list(struct pipe *pi)
6853 #if ENABLE_HUSH_CASE
6854 char *case_word = NULL;
6856 #if ENABLE_HUSH_LOOPS
6857 struct pipe *loop_top = NULL;
6858 char **for_lcur = NULL;
6859 char **for_list = NULL;
6861 smallint last_followup;
6863 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
6864 smalluint cond_code = 0;
6866 enum { cond_code = 0 };
6869 smallint rword; /* RES_foo */
6870 smallint last_rword; /* ditto */
6873 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
6876 #if ENABLE_HUSH_LOOPS
6877 /* Check syntax for "for" */
6878 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
6879 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
6881 /* current word is FOR or IN (BOLD in comments below) */
6882 if (cpipe->next == NULL) {
6883 syntax_error("malformed for");
6885 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
6888 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
6889 if (cpipe->next->res_word == RES_DO)
6891 /* next word is not "do". It must be "in" then ("FOR v in ...") */
6892 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
6893 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
6895 syntax_error("malformed for");
6897 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
6903 /* Past this point, all code paths should jump to ret: label
6904 * in order to return, no direct "return" statements please.
6905 * This helps to ensure that no memory is leaked. */
6913 last_rword = RES_XXXX;
6915 last_followup = PIPE_SEQ;
6916 rcode = G.last_exitcode;
6918 /* Go through list of pipes, (maybe) executing them. */
6919 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
6923 IF_HAS_KEYWORDS(rword = pi->res_word;)
6924 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
6925 rword, cond_code, last_rword);
6926 #if ENABLE_HUSH_LOOPS
6927 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
6928 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
6930 /* start of a loop: remember where loop starts */
6935 /* Still in the same "if...", "then..." or "do..." branch? */
6936 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
6937 if ((rcode == 0 && last_followup == PIPE_OR)
6938 || (rcode != 0 && last_followup == PIPE_AND)
6940 /* It is "<true> || CMD" or "<false> && CMD"
6941 * and we should not execute CMD */
6942 debug_printf_exec("skipped cmd because of || or &&\n");
6943 last_followup = pi->followup;
6947 last_followup = pi->followup;
6948 IF_HAS_KEYWORDS(last_rword = rword;)
6951 if (rword == RES_THEN) {
6952 /* if false; then ... fi has exitcode 0! */
6953 G.last_exitcode = rcode = EXIT_SUCCESS;
6954 /* "if <false> THEN cmd": skip cmd */
6958 if (rword == RES_ELSE || rword == RES_ELIF) {
6959 /* "if <true> then ... ELSE/ELIF cmd":
6960 * skip cmd and all following ones */
6965 #if ENABLE_HUSH_LOOPS
6966 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
6968 /* first loop through for */
6970 static const char encoded_dollar_at[] ALIGN1 = {
6971 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
6972 }; /* encoded representation of "$@" */
6973 static const char *const encoded_dollar_at_argv[] = {
6974 encoded_dollar_at, NULL
6975 }; /* argv list with one element: "$@" */
6978 vals = (char**)encoded_dollar_at_argv;
6979 if (pi->next->res_word == RES_IN) {
6980 /* if no variable values after "in" we skip "for" */
6981 if (!pi->next->cmds[0].argv) {
6982 G.last_exitcode = rcode = EXIT_SUCCESS;
6983 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
6986 vals = pi->next->cmds[0].argv;
6987 } /* else: "for var; do..." -> assume "$@" list */
6988 /* create list of variable values */
6989 debug_print_strings("for_list made from", vals);
6990 for_list = expand_strvec_to_strvec(vals);
6991 for_lcur = for_list;
6992 debug_print_strings("for_list", for_list);
6995 /* "for" loop is over, clean up */
7001 /* Insert next value from for_lcur */
7002 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7003 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7006 if (rword == RES_IN) {
7007 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7009 if (rword == RES_DONE) {
7010 continue; /* "done" has no cmds too */
7013 #if ENABLE_HUSH_CASE
7014 if (rword == RES_CASE) {
7015 case_word = expand_strvec_to_string(pi->cmds->argv);
7018 if (rword == RES_MATCH) {
7021 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7023 /* all prev words didn't match, does this one match? */
7024 argv = pi->cmds->argv;
7026 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7027 /* TODO: which FNM_xxx flags to use? */
7028 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7030 if (cond_code == 0) { /* match! we will execute this branch */
7031 free(case_word); /* make future "word)" stop */
7039 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7041 continue; /* not matched yet, skip this pipe */
7044 /* Just pressing <enter> in shell should check for jobs.
7045 * OTOH, in non-interactive shell this is useless
7046 * and only leads to extra job checks */
7047 if (pi->num_cmds == 0) {
7048 if (G_interactive_fd)
7049 goto check_jobs_and_continue;
7053 /* After analyzing all keywords and conditions, we decided
7054 * to execute this pipe. NB: have to do checkjobs(NULL)
7055 * after run_pipe to collect any background children,
7056 * even if list execution is to be stopped. */
7057 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7060 #if ENABLE_HUSH_LOOPS
7061 G.flag_break_continue = 0;
7063 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7065 /* We ran a builtin, function, or group.
7066 * rcode is already known
7067 * and we don't need to wait for anything. */
7068 G.last_exitcode = rcode;
7069 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7070 check_and_run_traps(0);
7071 #if ENABLE_HUSH_LOOPS
7072 /* Was it "break" or "continue"? */
7073 if (G.flag_break_continue) {
7074 smallint fbc = G.flag_break_continue;
7075 /* We might fall into outer *loop*,
7076 * don't want to break it too */
7078 G.depth_break_continue--;
7079 if (G.depth_break_continue == 0)
7080 G.flag_break_continue = 0;
7081 /* else: e.g. "continue 2" should *break* once, *then* continue */
7082 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7083 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
7084 goto check_jobs_and_break;
7085 /* "continue": simulate end of loop */
7090 #if ENABLE_HUSH_FUNCTIONS
7091 if (G.flag_return_in_progress == 1) {
7092 /* same as "goto check_jobs_and_break" */
7097 } else if (pi->followup == PIPE_BG) {
7098 /* What does bash do with attempts to background builtins? */
7099 /* even bash 3.2 doesn't do that well with nested bg:
7100 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7101 * I'm NOT treating inner &'s as jobs */
7102 check_and_run_traps(0);
7104 if (G.run_list_level == 1)
7107 /* Last command's pid goes to $! */
7108 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7109 G.last_exitcode = rcode = EXIT_SUCCESS;
7110 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7113 if (G.run_list_level == 1 && G_interactive_fd) {
7114 /* Waits for completion, then fg's main shell */
7115 rcode = checkjobs_and_fg_shell(pi);
7116 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7117 check_and_run_traps(0);
7120 { /* This one just waits for completion */
7121 rcode = checkjobs(pi);
7122 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7123 check_and_run_traps(0);
7125 G.last_exitcode = rcode;
7129 /* Analyze how result affects subsequent commands */
7131 if (rword == RES_IF || rword == RES_ELIF)
7134 #if ENABLE_HUSH_LOOPS
7135 /* Beware of "while false; true; do ..."! */
7136 if (pi->next && pi->next->res_word == RES_DO) {
7137 if (rword == RES_WHILE) {
7139 /* "while false; do...done" - exitcode 0 */
7140 G.last_exitcode = rcode = EXIT_SUCCESS;
7141 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7142 goto check_jobs_and_break;
7145 if (rword == RES_UNTIL) {
7147 debug_printf_exec(": until expr is true: breaking\n");
7148 check_jobs_and_break:
7156 check_jobs_and_continue:
7163 #if ENABLE_HUSH_LOOPS
7168 #if ENABLE_HUSH_CASE
7172 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7176 /* Select which version we will use */
7177 static int run_and_free_list(struct pipe *pi)
7180 debug_printf_exec("run_and_free_list entered\n");
7182 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7183 rcode = run_list(pi);
7185 /* free_pipe_list has the side effect of clearing memory.
7186 * In the long run that function can be merged with run_list,
7187 * but doing that now would hobble the debugging effort. */
7189 debug_printf_exec("run_and_free_list return %d\n", rcode);
7194 /* Called a few times only (or even once if "sh -c") */
7195 static void init_sigmasks(void)
7199 sigset_t old_blocked_set;
7201 if (!G.inherited_set_is_saved) {
7202 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
7203 G.inherited_set = G.blocked_set;
7205 old_blocked_set = G.blocked_set;
7207 mask = (1 << SIGQUIT);
7208 if (G_interactive_fd) {
7209 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
7210 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7211 mask |= SPECIAL_JOB_SIGS;
7213 G.non_DFL_mask = mask;
7218 sigaddset(&G.blocked_set, sig);
7222 sigdelset(&G.blocked_set, SIGCHLD);
7224 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
7225 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7227 /* POSIX allows shell to re-enable SIGCHLD
7228 * even if it was SIG_IGN on entry */
7229 #if ENABLE_HUSH_FAST
7230 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7231 if (!G.inherited_set_is_saved)
7232 signal(SIGCHLD, SIGCHLD_handler);
7234 if (!G.inherited_set_is_saved)
7235 signal(SIGCHLD, SIG_DFL);
7238 G.inherited_set_is_saved = 1;
7243 static void maybe_set_to_sigexit(int sig)
7245 void (*handler)(int);
7246 /* non_DFL_mask'ed signals are, well, masked,
7247 * no need to set handler for them.
7249 if (!((G.non_DFL_mask >> sig) & 1)) {
7250 handler = signal(sig, sigexit);
7251 if (handler == SIG_IGN) /* oops... restore back to IGN! */
7252 signal(sig, handler);
7255 /* Set handlers to restore tty pgrp and exit */
7256 static void set_fatal_handlers(void)
7258 /* We _must_ restore tty pgrp on fatal signals */
7260 maybe_set_to_sigexit(SIGILL );
7261 maybe_set_to_sigexit(SIGFPE );
7262 maybe_set_to_sigexit(SIGBUS );
7263 maybe_set_to_sigexit(SIGSEGV);
7264 maybe_set_to_sigexit(SIGTRAP);
7265 } /* else: hush is perfect. what SEGV? */
7266 maybe_set_to_sigexit(SIGABRT);
7267 /* bash 3.2 seems to handle these just like 'fatal' ones */
7268 maybe_set_to_sigexit(SIGPIPE);
7269 maybe_set_to_sigexit(SIGALRM);
7270 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
7271 * if we aren't interactive... but in this case
7272 * we never want to restore pgrp on exit, and this fn is not called */
7273 /*maybe_set_to_sigexit(SIGHUP );*/
7274 /*maybe_set_to_sigexit(SIGTERM);*/
7275 /*maybe_set_to_sigexit(SIGINT );*/
7279 static int set_mode(const char cstate, const char mode)
7281 int state = (cstate == '-' ? 1 : 0);
7283 case 'n': G.n_mode = state; break;
7284 case 'x': IF_HUSH_MODE_X(G_x_mode = state;) break;
7285 default: return EXIT_FAILURE;
7287 return EXIT_SUCCESS;
7290 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7291 int hush_main(int argc, char **argv)
7294 unsigned builtin_argc;
7296 struct variable *cur_var;
7299 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
7300 G.last_exitcode = EXIT_SUCCESS;
7302 G.argv0_for_re_execing = argv[0];
7304 /* Deal with HUSH_VERSION */
7305 G.shell_ver.flg_export = 1;
7306 G.shell_ver.flg_read_only = 1;
7307 /* Code which handles ${var/P/R} needs writable values for all variables,
7308 * therefore we xstrdup: */
7309 G.shell_ver.varstr = xstrdup(hush_version_str),
7310 G.top_var = &G.shell_ver;
7311 /* Create shell local variables from the values
7312 * currently living in the environment */
7313 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7314 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7315 cur_var = G.top_var;
7318 char *value = strchr(*e, '=');
7319 if (value) { /* paranoia */
7320 cur_var->next = xzalloc(sizeof(*cur_var));
7321 cur_var = cur_var->next;
7322 cur_var->varstr = *e;
7323 cur_var->max_len = strlen(*e);
7324 cur_var->flg_export = 1;
7328 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7329 debug_printf_env("putenv '%s'\n", G.shell_ver.varstr);
7330 putenv(G.shell_ver.varstr);
7333 set_pwd_var(/*exp:*/ 1);
7334 /* bash also exports SHLVL and _,
7335 * and sets (but doesn't export) the following variables:
7337 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7338 * BASH_VERSION='3.2.0(1)-release'
7340 * MACHTYPE=i386-pc-linux-gnu
7342 * HOSTNAME=<xxxxxxxxxx>
7343 * PPID=<NNNNN> - we also do it elsewhere
7354 * PIPESTATUS=([0]="0")
7355 * HISTFILE=/<xxx>/.bash_history
7359 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7361 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7371 #if ENABLE_FEATURE_EDITING
7372 G.line_input_state = new_line_input_t(FOR_SHELL);
7374 G.global_argc = argc;
7375 G.global_argv = argv;
7376 /* Initialize some more globals to non-zero values */
7377 cmdedit_update_prompt();
7379 if (setjmp(die_jmp)) {
7380 /* xfunc has failed! die die die */
7381 /* no EXIT traps, this is an escape hatch! */
7383 hush_exit(xfunc_error_retval);
7386 /* Shell is non-interactive at first. We need to call
7387 * init_sigmasks() if we are going to execute "sh <script>",
7388 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7389 * If we later decide that we are interactive, we run init_sigmasks()
7390 * in order to intercept (more) signals.
7394 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7397 opt = getopt(argc, argv, "+c:xins"
7400 # if ENABLE_HUSH_FUNCTIONS
7410 * sh ... -c 'script'
7411 * sh ... -c 'script' ARG0 [ARG1...]
7412 * On NOMMU, if builtin_argc != 0,
7413 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7414 * "" needs to be replaced with NULL
7415 * and BARGV vector fed to builtin function.
7416 * Note: the form without ARG0 never happens:
7417 * sh ... -c 'builtin' BARGV... ""
7420 G.root_pid = getpid();
7421 G.root_ppid = getppid();
7423 G.global_argv = argv + optind;
7424 G.global_argc = argc - optind;
7426 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7427 const struct built_in_command *x;
7430 x = find_builtin(optarg);
7431 if (x) { /* paranoia */
7432 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7433 G.global_argv += builtin_argc;
7434 G.global_argv[-1] = NULL; /* replace "" */
7435 G.last_exitcode = x->b_function(argv + optind - 1);
7439 if (!G.global_argv[0]) {
7440 /* -c 'script' (no params): prevent empty $0 */
7441 G.global_argv--; /* points to argv[i] of 'script' */
7442 G.global_argv[0] = argv[0];
7444 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7446 parse_and_run_string(optarg);
7449 /* Well, we cannot just declare interactiveness,
7450 * we have to have some stuff (ctty, etc) */
7451 /* G_interactive_fd++; */
7454 /* "-s" means "read from stdin", but this is how we always
7455 * operate, so simply do nothing here. */
7458 case '<': /* "big heredoc" support */
7459 full_write1_str(optarg);
7462 unsigned long long empty_trap_mask;
7464 G.root_pid = bb_strtou(optarg, &optarg, 16);
7466 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7468 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7470 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7472 builtin_argc = bb_strtou(optarg, &optarg, 16);
7474 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7475 if (empty_trap_mask != 0) {
7478 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7479 for (sig = 1; sig < NSIG; sig++) {
7480 if (empty_trap_mask & (1LL << sig)) {
7481 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7482 sigaddset(&G.blocked_set, sig);
7485 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7487 # if ENABLE_HUSH_LOOPS
7489 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7495 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7497 # if ENABLE_HUSH_FUNCTIONS
7499 struct function *funcp = new_function(optarg);
7500 /* funcp->name is already set to optarg */
7501 /* funcp->body is set to NULL. It's a special case. */
7502 funcp->body_as_string = argv[optind];
7510 if (set_mode('-', opt) == 0) /* no error */
7514 fprintf(stderr, "Usage: sh [FILE]...\n"
7515 " or: sh -c command [args]...\n\n");
7521 } /* option parsing loop */
7524 G.root_pid = getpid();
7525 G.root_ppid = getppid();
7528 /* If we are login shell... */
7529 if (argv[0] && argv[0][0] == '-') {
7531 debug_printf("sourcing /etc/profile\n");
7532 input = fopen_for_read("/etc/profile");
7533 if (input != NULL) {
7534 close_on_exec_on(fileno(input));
7536 parse_and_run_file(input);
7539 /* bash: after sourcing /etc/profile,
7540 * tries to source (in the given order):
7541 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7542 * stopping on first found. --noprofile turns this off.
7543 * bash also sources ~/.bash_logout on exit.
7544 * If called as sh, skips .bash_XXX files.
7551 * "bash <script>" (which is never interactive (unless -i?))
7552 * sources $BASH_ENV here (without scanning $PATH).
7553 * If called as sh, does the same but with $ENV.
7555 debug_printf("running script '%s'\n", argv[optind]);
7556 G.global_argv = argv + optind;
7557 G.global_argc = argc - optind;
7558 input = xfopen_for_read(argv[optind]);
7559 close_on_exec_on(fileno(input));
7561 parse_and_run_file(input);
7562 #if ENABLE_FEATURE_CLEAN_UP
7568 /* Up to here, shell was non-interactive. Now it may become one.
7569 * NB: don't forget to (re)run init_sigmasks() as needed.
7572 /* A shell is interactive if the '-i' flag was given,
7573 * or if all of the following conditions are met:
7575 * no arguments remaining or the -s flag given
7576 * standard input is a terminal
7577 * standard output is a terminal
7578 * Refer to Posix.2, the description of the 'sh' utility.
7581 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7582 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7583 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7584 if (G_saved_tty_pgrp < 0)
7585 G_saved_tty_pgrp = 0;
7587 /* try to dup stdin to high fd#, >= 255 */
7588 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7589 if (G_interactive_fd < 0) {
7590 /* try to dup to any fd */
7591 G_interactive_fd = dup(STDIN_FILENO);
7592 if (G_interactive_fd < 0) {
7594 G_interactive_fd = 0;
7595 G_saved_tty_pgrp = 0;
7598 // TODO: track & disallow any attempts of user
7599 // to (inadvertently) close/redirect G_interactive_fd
7601 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7602 if (G_interactive_fd) {
7603 close_on_exec_on(G_interactive_fd);
7605 if (G_saved_tty_pgrp) {
7606 /* If we were run as 'hush &', sleep until we are
7607 * in the foreground (tty pgrp == our pgrp).
7608 * If we get started under a job aware app (like bash),
7609 * make sure we are now in charge so we don't fight over
7610 * who gets the foreground */
7612 pid_t shell_pgrp = getpgrp();
7613 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7614 if (G_saved_tty_pgrp == shell_pgrp)
7616 /* send TTIN to ourself (should stop us) */
7617 kill(- shell_pgrp, SIGTTIN);
7621 /* Block some signals */
7624 if (G_saved_tty_pgrp) {
7625 /* Set other signals to restore saved_tty_pgrp */
7626 set_fatal_handlers();
7627 /* Put ourselves in our own process group
7628 * (bash, too, does this only if ctty is available) */
7629 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7630 /* Grab control of the terminal */
7631 tcsetpgrp(G_interactive_fd, getpid());
7633 /* -1 is special - makes xfuncs longjmp, not exit
7634 * (we reset die_sleep = 0 whereever we [v]fork) */
7635 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7639 #elif ENABLE_HUSH_INTERACTIVE
7640 /* No job control compiled in, only prompt/line editing */
7641 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7642 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7643 if (G_interactive_fd < 0) {
7644 /* try to dup to any fd */
7645 G_interactive_fd = dup(STDIN_FILENO);
7646 if (G_interactive_fd < 0)
7648 G_interactive_fd = 0;
7651 if (G_interactive_fd) {
7652 close_on_exec_on(G_interactive_fd);
7656 /* We have interactiveness code disabled */
7660 * if interactive but not a login shell, sources ~/.bashrc
7661 * (--norc turns this off, --rcfile <file> overrides)
7664 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7665 /* note: ash and hush share this string */
7666 printf("\n\n%s %s\n"
7667 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7670 "hush - the humble shell"
7674 parse_and_run_file(stdin);
7677 #if ENABLE_FEATURE_CLEAN_UP
7678 if (G.cwd != bb_msg_unknown)
7680 cur_var = G.top_var->next;
7682 struct variable *tmp = cur_var;
7683 if (!cur_var->max_len)
7684 free(cur_var->varstr);
7685 cur_var = cur_var->next;
7689 hush_exit(G.last_exitcode);
7694 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7695 int msh_main(int argc, char **argv)
7697 //bb_error_msg("msh is deprecated, please use hush instead");
7698 return hush_main(argc, argv);
7706 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7711 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7718 return applet_main_func(argc, argv - argc);
7721 static int FAST_FUNC builtin_test(char **argv)
7723 return run_applet_main(argv, test_main);
7726 static int FAST_FUNC builtin_echo(char **argv)
7728 return run_applet_main(argv, echo_main);
7732 static int FAST_FUNC builtin_printf(char **argv)
7734 return run_applet_main(argv, printf_main);
7738 static char **skip_dash_dash(char **argv)
7741 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7746 static int FAST_FUNC builtin_eval(char **argv)
7748 int rcode = EXIT_SUCCESS;
7750 argv = skip_dash_dash(argv);
7752 char *str = expand_strvec_to_string(argv);
7754 * eval "echo Hi; done" ("done" is syntax error):
7755 * "echo Hi" will not execute too.
7757 parse_and_run_string(str);
7759 rcode = G.last_exitcode;
7764 static int FAST_FUNC builtin_cd(char **argv)
7768 argv = skip_dash_dash(argv);
7770 if (newdir == NULL) {
7771 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7772 * bash says "bash: cd: HOME not set" and does nothing
7775 const char *home = get_local_var_value("HOME");
7776 newdir = home ? home : "/";
7778 if (chdir(newdir)) {
7779 /* Mimic bash message exactly */
7780 bb_perror_msg("cd: %s", newdir);
7781 return EXIT_FAILURE;
7783 /* Read current dir (get_cwd(1) is inside) and set PWD.
7784 * Note: do not enforce exporting. If PWD was unset or unexported,
7785 * set it again, but do not export. bash does the same.
7787 set_pwd_var(/*exp:*/ 0);
7788 return EXIT_SUCCESS;
7791 static int FAST_FUNC builtin_exec(char **argv)
7793 argv = skip_dash_dash(argv);
7794 if (argv[0] == NULL)
7795 return EXIT_SUCCESS; /* bash does this */
7797 /* Careful: we can end up here after [v]fork. Do not restore
7798 * tty pgrp then, only top-level shell process does that */
7799 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7800 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7802 /* TODO: if exec fails, bash does NOT exit! We do.
7803 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7804 * and tcsetpgrp, and this is inherently racy.
7806 execvp_or_die(argv);
7809 static int FAST_FUNC builtin_exit(char **argv)
7811 debug_printf_exec("%s()\n", __func__);
7813 /* interactive bash:
7814 * # trap "echo EEE" EXIT
7817 * There are stopped jobs.
7818 * (if there are _stopped_ jobs, running ones don't count)
7821 # EEE (then bash exits)
7823 * we can use G.exiting = -1 as indicator "last cmd was exit"
7826 /* note: EXIT trap is run by hush_exit */
7827 argv = skip_dash_dash(argv);
7828 if (argv[0] == NULL)
7829 hush_exit(G.last_exitcode);
7830 /* mimic bash: exit 123abc == exit 255 + error msg */
7831 xfunc_error_retval = 255;
7832 /* bash: exit -2 == exit 254, no error msg */
7833 hush_exit(xatoi(argv[0]) & 0xff);
7836 static void print_escaped(const char *s)
7841 const char *p = strchrnul(s, '\'');
7842 /* print 'xxxx', possibly just '' */
7843 printf("'%.*s'", (int)(p - s), s);
7848 /* s points to '; print "'''...'''" */
7850 do putchar('\''); while (*++s == '\'');
7855 #if !ENABLE_HUSH_LOCAL
7856 #define helper_export_local(argv, exp, lvl) \
7857 helper_export_local(argv, exp)
7859 static void helper_export_local(char **argv, int exp, int lvl)
7863 char *name_end = strchrnul(name, '=');
7865 /* So far we do not check that name is valid (TODO?) */
7867 if (*name_end == '\0') {
7868 struct variable *var, **vpp;
7870 vpp = get_ptr_to_local_var(name, name_end - name);
7871 var = vpp ? *vpp : NULL;
7873 if (exp == -1) { /* unexporting? */
7874 /* export -n NAME (without =VALUE) */
7876 var->flg_export = 0;
7877 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7879 } /* else: export -n NOT_EXISTING_VAR: no-op */
7882 if (exp == 1) { /* exporting? */
7883 /* export NAME (without =VALUE) */
7885 var->flg_export = 1;
7886 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7887 putenv(var->varstr);
7891 /* Exporting non-existing variable.
7892 * bash does not put it in environment,
7893 * but remembers that it is exported,
7894 * and does put it in env when it is set later.
7895 * We just set it to "" and export. */
7896 /* Or, it's "local NAME" (without =VALUE).
7897 * bash sets the value to "". */
7898 name = xasprintf("%s=", name);
7900 /* (Un)exporting/making local NAME=VALUE */
7901 name = xstrdup(name);
7903 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7907 static int FAST_FUNC builtin_export(char **argv)
7909 unsigned opt_unexport;
7911 #if ENABLE_HUSH_EXPORT_N
7912 /* "!": do not abort on errors */
7913 opt_unexport = getopt32(argv, "!n");
7914 if (opt_unexport == (uint32_t)-1)
7915 return EXIT_FAILURE;
7922 if (argv[0] == NULL) {
7929 /* ash emits: export VAR='VAL'
7930 * bash: declare -x VAR="VAL"
7931 * we follow ash example */
7932 const char *s = *e++;
7933 const char *p = strchr(s, '=');
7935 if (!p) /* wtf? take next variable */
7938 printf("export %.*s", (int)(p - s) + 1, s);
7939 print_escaped(p + 1);
7943 /*fflush_all(); - done after each builtin anyway */
7945 return EXIT_SUCCESS;
7948 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7950 return EXIT_SUCCESS;
7953 #if ENABLE_HUSH_LOCAL
7954 static int FAST_FUNC builtin_local(char **argv)
7956 if (G.func_nest_level == 0) {
7957 bb_error_msg("%s: not in a function", argv[0]);
7958 return EXIT_FAILURE; /* bash compat */
7960 helper_export_local(argv, 0, G.func_nest_level);
7961 return EXIT_SUCCESS;
7965 static int FAST_FUNC builtin_trap(char **argv)
7971 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7976 /* No args: print all trapped */
7977 for (i = 0; i < NSIG; ++i) {
7980 print_escaped(G.traps[i]);
7981 /* note: bash adds "SIG", but only if invoked
7982 * as "bash". If called as "sh", or if set -o posix,
7983 * then it prints short signal names.
7984 * We are printing short names: */
7985 printf(" %s\n", get_signame(i));
7988 /*fflush_all(); - done after each builtin anyway */
7989 return EXIT_SUCCESS;
7993 /* If first arg is a number: reset all specified signals */
7994 sig = bb_strtou(*argv, NULL, 10);
8000 sig = get_signum(*argv++);
8001 if (sig < 0 || sig >= NSIG) {
8003 /* Mimic bash message exactly */
8004 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8009 G.traps[sig] = xstrdup(new_cmd);
8011 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8012 get_signame(sig), sig, G.traps[sig]);
8014 /* There is no signal for 0 (EXIT) */
8019 sigaddset(&G.blocked_set, sig);
8021 /* There was a trap handler, we are removing it
8022 * (if sig has non-DFL handling,
8023 * we don't need to do anything) */
8024 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
8026 sigdelset(&G.blocked_set, sig);
8029 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8033 if (!argv[1]) { /* no second arg */
8034 bb_error_msg("trap: invalid arguments");
8035 return EXIT_FAILURE;
8038 /* First arg is "-": reset all specified to default */
8039 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8040 /* Everything else: set arg as signal handler
8041 * (includes "" case, which ignores signal) */
8042 if (argv[0][0] == '-') {
8043 if (argv[0][1] == '\0') { /* "-" */
8044 /* new_cmd remains NULL: "reset these sigs" */
8047 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8050 /* else: "-something", no special meaning */
8055 goto process_sig_list;
8058 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8059 static int FAST_FUNC builtin_type(char **argv)
8061 int ret = EXIT_SUCCESS;
8067 if (0) {} /* make conditional compile easier below */
8068 /*else if (find_alias(*argv))
8069 type = "an alias";*/
8070 #if ENABLE_HUSH_FUNCTIONS
8071 else if (find_function(*argv))
8072 type = "a function";
8074 else if (find_builtin(*argv))
8075 type = "a shell builtin";
8076 else if ((path = find_in_path(*argv)) != NULL)
8079 bb_error_msg("type: %s: not found", *argv);
8084 printf("%s is %s\n", *argv, type);
8092 /* built-in 'fg' and 'bg' handler */
8093 static int FAST_FUNC builtin_fg_bg(char **argv)
8098 if (!G_interactive_fd)
8099 return EXIT_FAILURE;
8101 /* If they gave us no args, assume they want the last backgrounded task */
8103 for (pi = G.job_list; pi; pi = pi->next) {
8104 if (pi->jobid == G.last_jobid) {
8108 bb_error_msg("%s: no current job", argv[0]);
8109 return EXIT_FAILURE;
8111 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8112 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8113 return EXIT_FAILURE;
8115 for (pi = G.job_list; pi; pi = pi->next) {
8116 if (pi->jobid == jobnum) {
8120 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8121 return EXIT_FAILURE;
8123 /* TODO: bash prints a string representation
8124 * of job being foregrounded (like "sleep 1 | cat") */
8125 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8126 /* Put the job into the foreground. */
8127 tcsetpgrp(G_interactive_fd, pi->pgrp);
8130 /* Restart the processes in the job */
8131 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8132 for (i = 0; i < pi->num_cmds; i++) {
8133 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8134 pi->cmds[i].is_stopped = 0;
8136 pi->stopped_cmds = 0;
8138 i = kill(- pi->pgrp, SIGCONT);
8140 if (errno == ESRCH) {
8141 delete_finished_bg_job(pi);
8142 return EXIT_SUCCESS;
8144 bb_perror_msg("kill (SIGCONT)");
8147 if (argv[0][0] == 'f') {
8149 return checkjobs_and_fg_shell(pi);
8151 return EXIT_SUCCESS;
8155 #if ENABLE_HUSH_HELP
8156 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8158 const struct built_in_command *x;
8161 "Built-in commands:\n"
8162 "------------------\n");
8163 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8165 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8168 return EXIT_SUCCESS;
8173 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8176 const char *status_string;
8178 for (job = G.job_list; job; job = job->next) {
8179 if (job->alive_cmds == job->stopped_cmds)
8180 status_string = "Stopped";
8182 status_string = "Running";
8184 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8186 return EXIT_SUCCESS;
8191 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8196 # ifdef M_TRIM_THRESHOLD
8197 /* Optional. Reduces probability of false positives */
8200 /* Crude attempt to find where "free memory" starts,
8201 * sans fragmentation. */
8203 l = (unsigned long)p;
8206 if (l < (unsigned long)p) l = (unsigned long)p;
8209 if (!G.memleak_value)
8210 G.memleak_value = l;
8212 l -= G.memleak_value;
8219 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8224 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8227 return EXIT_SUCCESS;
8230 static int FAST_FUNC builtin_read(char **argv)
8239 /* "!": do not abort on errors.
8240 * Option string must start with "sr" to match BUILTIN_READ_xxx
8242 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8243 if (read_flags == (uint32_t)-1)
8244 return EXIT_FAILURE;
8247 r = shell_builtin_read(set_local_var_from_halves,
8249 get_local_var_value("IFS"), /* can be NULL */
8257 if ((uintptr_t)r > 1) {
8258 bb_error_msg("%s", r);
8259 r = (char*)(uintptr_t)1;
8262 return (uintptr_t)r;
8265 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8266 * built-in 'set' handler
8268 * set [-abCefhmnuvx] [-o option] [argument...]
8269 * set [+abCefhmnuvx] [+o option] [argument...]
8270 * set -- [argument...]
8273 * Implementations shall support the options in both their hyphen and
8274 * plus-sign forms. These options can also be specified as options to sh.
8276 * Write out all variables and their values: set
8277 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8278 * Turn on the -x and -v options: set -xv
8279 * Unset all positional parameters: set --
8280 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8281 * Set the positional parameters to the expansion of x, even if x expands
8282 * with a leading '-' or '+': set -- $x
8284 * So far, we only support "set -- [argument...]" and some of the short names.
8286 static int FAST_FUNC builtin_set(char **argv)
8289 char **pp, **g_argv;
8290 char *arg = *++argv;
8294 for (e = G.top_var; e; e = e->next)
8296 return EXIT_SUCCESS;
8300 if (!strcmp(arg, "--")) {
8304 if (arg[0] != '+' && arg[0] != '-')
8306 for (n = 1; arg[n]; ++n)
8307 if (set_mode(arg[0], arg[n]))
8309 } while ((arg = *++argv) != NULL);
8310 /* Now argv[0] is 1st argument */
8313 return EXIT_SUCCESS;
8316 /* NB: G.global_argv[0] ($0) is never freed/changed */
8317 g_argv = G.global_argv;
8318 if (G.global_args_malloced) {
8324 G.global_args_malloced = 1;
8325 pp = xzalloc(sizeof(pp[0]) * 2);
8326 pp[0] = g_argv[0]; /* retain $0 */
8329 /* This realloc's G.global_argv */
8330 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8337 return EXIT_SUCCESS;
8339 /* Nothing known, so abort */
8341 bb_error_msg("set: %s: invalid option", arg);
8342 return EXIT_FAILURE;
8345 static int FAST_FUNC builtin_shift(char **argv)
8348 argv = skip_dash_dash(argv);
8352 if (n >= 0 && n < G.global_argc) {
8353 if (G.global_args_malloced) {
8356 free(G.global_argv[m++]);
8359 memmove(&G.global_argv[1], &G.global_argv[n+1],
8360 G.global_argc * sizeof(G.global_argv[0]));
8361 return EXIT_SUCCESS;
8363 return EXIT_FAILURE;
8366 static int FAST_FUNC builtin_source(char **argv)
8368 char *arg_path, *filename;
8371 #if ENABLE_HUSH_FUNCTIONS
8375 argv = skip_dash_dash(argv);
8378 /* bash says: "bash: .: filename argument required" */
8379 return 2; /* bash compat */
8382 if (!strchr(filename, '/')) {
8383 arg_path = find_in_path(filename);
8385 filename = arg_path;
8387 input = fopen_or_warn(filename, "r");
8390 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8391 return EXIT_FAILURE;
8393 close_on_exec_on(fileno(input));
8395 #if ENABLE_HUSH_FUNCTIONS
8396 sv_flg = G.flag_return_in_progress;
8397 /* "we are inside sourced file, ok to use return" */
8398 G.flag_return_in_progress = -1;
8400 save_and_replace_G_args(&sv, argv);
8402 parse_and_run_file(input);
8405 restore_G_args(&sv, argv);
8406 #if ENABLE_HUSH_FUNCTIONS
8407 G.flag_return_in_progress = sv_flg;
8410 return G.last_exitcode;
8413 static int FAST_FUNC builtin_umask(char **argv)
8419 argv = skip_dash_dash(argv);
8421 mode_t old_mask = mask;
8424 rc = bb_parse_mode(argv[0], &mask);
8429 * bash: umask: 'q': invalid symbolic mode operator
8430 * bash: umask: 999: octal number out of range
8432 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8437 printf("%04o\n", (unsigned) mask);
8438 /* fall through and restore mask which we set to 0 */
8442 return !rc; /* rc != 0 - success */
8445 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8446 static int FAST_FUNC builtin_unset(char **argv)
8451 /* "!": do not abort on errors */
8452 /* "+": stop at 1st non-option */
8453 opts = getopt32(argv, "!+vf");
8454 if (opts == (unsigned)-1)
8455 return EXIT_FAILURE;
8457 bb_error_msg("unset: -v and -f are exclusive");
8458 return EXIT_FAILURE;
8464 if (!(opts & 2)) { /* not -f */
8465 if (unset_local_var(*argv)) {
8466 /* unset <nonexistent_var> doesn't fail.
8467 * Error is when one tries to unset RO var.
8468 * Message was printed by unset_local_var. */
8472 #if ENABLE_HUSH_FUNCTIONS
8482 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8483 static int FAST_FUNC builtin_wait(char **argv)
8485 int ret = EXIT_SUCCESS;
8488 argv = skip_dash_dash(argv);
8489 if (argv[0] == NULL) {
8490 /* Don't care about wait results */
8491 /* Note 1: must wait until there are no more children */
8492 /* Note 2: must be interruptible */
8494 * $ sleep 3 & sleep 6 & wait
8499 * $ sleep 3 & sleep 6 & wait
8503 * ^C <-- after ~4 sec from keyboard
8506 sigaddset(&G.blocked_set, SIGCHLD);
8507 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8510 if (errno == ECHILD)
8512 /* Wait for SIGCHLD or any other signal of interest */
8513 /* sigtimedwait with infinite timeout: */
8514 sig = sigwaitinfo(&G.blocked_set, NULL);
8516 sig = check_and_run_traps(sig);
8517 if (sig && sig != SIGCHLD) { /* see note 2 */
8523 sigdelset(&G.blocked_set, SIGCHLD);
8524 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8528 /* This is probably buggy wrt interruptible-ness */
8530 pid_t pid = bb_strtou(*argv, NULL, 10);
8532 /* mimic bash message */
8533 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8534 return EXIT_FAILURE;
8536 if (waitpid(pid, &status, 0) == pid) {
8537 if (WIFSIGNALED(status))
8538 ret = 128 + WTERMSIG(status);
8539 else if (WIFEXITED(status))
8540 ret = WEXITSTATUS(status);
8544 bb_perror_msg("wait %s", *argv);
8553 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8554 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8557 def = bb_strtou(argv[1], NULL, 10);
8558 if (errno || def < def_min || argv[2]) {
8559 bb_error_msg("%s: bad arguments", argv[0]);
8567 #if ENABLE_HUSH_LOOPS
8568 static int FAST_FUNC builtin_break(char **argv)
8571 if (G.depth_of_loop == 0) {
8572 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8573 return EXIT_SUCCESS; /* bash compat */
8575 G.flag_break_continue++; /* BC_BREAK = 1 */
8577 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8578 if (depth == UINT_MAX)
8579 G.flag_break_continue = BC_BREAK;
8580 if (G.depth_of_loop < depth)
8581 G.depth_break_continue = G.depth_of_loop;
8583 return EXIT_SUCCESS;
8586 static int FAST_FUNC builtin_continue(char **argv)
8588 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8589 return builtin_break(argv);
8593 #if ENABLE_HUSH_FUNCTIONS
8594 static int FAST_FUNC builtin_return(char **argv)
8598 if (G.flag_return_in_progress != -1) {
8599 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8600 return EXIT_FAILURE; /* bash compat */
8603 G.flag_return_in_progress = 1;
8606 * out of range: wraps around at 256, does not error out
8607 * non-numeric param:
8608 * f() { false; return qwe; }; f; echo $?
8609 * bash: return: qwe: numeric argument required <== we do this
8610 * 255 <== we also do this
8612 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);