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 * subst operator: ${var/[/]expr/expr}
54 * brace expansion: one/{two,three,four}
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
67 * export builtin should be special, its arguments are assignments
68 * and therefore expansion of them should be "one-word" expansion:
69 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
71 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
72 * ls: cannot access i=a: No such file or directory
73 * ls: cannot access b: No such file or directory
74 * Note1: same applies to local builtin.
75 * Note2: bash 3.2.33(1) does this only if export word itself
77 * $ export i=`echo 'aaa bbb'`; echo "$i"
79 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
82 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
84 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
85 #include <malloc.h> /* for malloc_trim */
87 /* #include <dmalloc.h> */
92 #include "shell_common.h"
95 #if ENABLE_HUSH_RANDOM_SUPPORT
98 # define CLEAR_RANDOM_T(rnd) ((void)0)
101 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
106 #define LEAK_HUNTING 0
107 #define BUILD_AS_NOMMU 0
108 /* Enable/disable sanity checks. Ok to enable in production,
109 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
110 * Keeping 1 for now even in released versions.
113 /* Slightly bigger (+200 bytes), but faster hush.
114 * So far it only enables a trick with counting SIGCHLDs and forks,
115 * which allows us to do fewer waitpid's.
116 * (we can detect a case where neither forks were done nor SIGCHLDs happened
117 * and therefore waitpid will return the same result as last time)
119 #define ENABLE_HUSH_FAST 0
124 # undef USE_FOR_NOMMU
127 # define USE_FOR_NOMMU(...) __VA_ARGS__
128 # define USE_FOR_MMU(...)
131 #include "NUM_APPLETS.h"
133 /* STANDALONE does not make sense, and won't compile */
134 # undef CONFIG_FEATURE_SH_STANDALONE
135 # undef ENABLE_FEATURE_SH_STANDALONE
136 # undef IF_FEATURE_SH_STANDALONE
137 # undef IF_NOT_FEATURE_SH_STANDALONE
138 # define ENABLE_FEATURE_SH_STANDALONE 0
139 # define IF_FEATURE_SH_STANDALONE(...)
140 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
143 #if !ENABLE_HUSH_INTERACTIVE
144 # undef ENABLE_FEATURE_EDITING
145 # define ENABLE_FEATURE_EDITING 0
146 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
147 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
150 /* Do we support ANY keywords? */
151 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
152 # define HAS_KEYWORDS 1
153 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
154 # define IF_HAS_NO_KEYWORDS(...)
156 # define HAS_KEYWORDS 0
157 # define IF_HAS_KEYWORDS(...)
158 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
161 /* If you comment out one of these below, it will be #defined later
162 * to perform debug printfs to stderr: */
163 #define debug_printf(...) do {} while (0)
164 /* Finer-grained debug switches */
165 #define debug_printf_parse(...) do {} while (0)
166 #define debug_print_tree(a, b) do {} while (0)
167 #define debug_printf_exec(...) do {} while (0)
168 #define debug_printf_env(...) do {} while (0)
169 #define debug_printf_jobs(...) do {} while (0)
170 #define debug_printf_expand(...) do {} while (0)
171 #define debug_printf_varexp(...) do {} while (0)
172 #define debug_printf_glob(...) do {} while (0)
173 #define debug_printf_list(...) do {} while (0)
174 #define debug_printf_subst(...) do {} while (0)
175 #define debug_printf_clean(...) do {} while (0)
177 #define ERR_PTR ((void*)(long)1)
179 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
181 #define _SPECIAL_VARS_STR "_*@$!?#"
182 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
183 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
185 #define SPECIAL_VAR_SYMBOL 3
189 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
191 /* This supports saving pointers malloced in vfork child,
192 * to be freed in the parent.
195 typedef struct nommu_save_t {
197 struct variable *old_vars;
199 char **argv_from_re_execing;
203 typedef enum reserved_style {
212 #if ENABLE_HUSH_LOOPS
219 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
224 /* three pseudo-keywords support contrived "case" syntax: */
225 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
226 RES_MATCH , /* "word)" */
227 RES_CASE_BODY, /* "this command is inside CASE" */
234 typedef struct o_string {
236 int length; /* position where data is appended */
238 /* Protect newly added chars against globbing
239 * (by prepending \ to *, ?, [, \) */
242 /* At least some part of the string was inside '' or "",
243 * possibly empty one: word"", wo''rd etc. */
245 smallint has_empty_slot;
246 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
249 MAYBE_ASSIGNMENT = 0,
250 DEFINITELY_ASSIGNMENT = 1,
252 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
254 /* Used for initialization: o_string foo = NULL_O_STRING; */
255 #define NULL_O_STRING { NULL }
257 /* I can almost use ordinary FILE*. Is open_memstream() universally
258 * available? Where is it documented? */
259 typedef struct in_str {
261 /* eof_flag=1: last char in ->p is really an EOF */
262 char eof_flag; /* meaningless if ->p == NULL */
264 #if ENABLE_HUSH_INTERACTIVE
266 smallint promptmode; /* 0: PS1, 1: PS2 */
269 int (*get) (struct in_str *) FAST_FUNC;
270 int (*peek) (struct in_str *) FAST_FUNC;
272 #define i_getch(input) ((input)->get(input))
273 #define i_peek(input) ((input)->peek(input))
275 /* The descrip member of this structure is only used to make
276 * debugging output pretty */
277 static const struct {
279 signed char default_fd;
282 { O_RDONLY, 0, "<" },
283 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
284 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
285 { O_CREAT|O_RDWR, 1, "<>" },
286 { O_RDONLY, 0, "<<" },
287 /* Should not be needed. Bogus default_fd helps in debugging */
288 /* { O_RDONLY, 77, "<<" }, */
291 struct redir_struct {
292 struct redir_struct *next;
293 char *rd_filename; /* filename */
294 int rd_fd; /* fd to redirect */
295 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
297 smallint rd_type; /* (enum redir_type) */
298 /* note: for heredocs, rd_filename contains heredoc delimiter,
299 * and subsequently heredoc itself; and rd_dup is a bitmask:
300 * bit 0: do we need to trim leading tabs?
301 * bit 1: is heredoc quoted (<<'delim' syntax) ?
304 typedef enum redir_type {
306 REDIRECT_OVERWRITE = 1,
309 REDIRECT_HEREDOC = 4,
310 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
313 REDIRFD_SYNTAX_ERR = -2,
314 REDIRFD_TO_FILE = -1,
315 /* otherwise, rd_fd is redirected to rd_dup */
317 HEREDOC_SKIPTABS = 1,
323 pid_t pid; /* 0 if exited */
324 int assignment_cnt; /* how many argv[i] are assignments? */
325 smallint is_stopped; /* is the command currently running? */
326 smallint cmd_type; /* CMD_xxx */
328 #define CMD_SUBSHELL 1
330 /* used for "[[ EXPR ]]" */
331 #if ENABLE_HUSH_BASH_COMPAT
332 # define CMD_SINGLEWORD_NOGLOB 2
335 /* used for "export noglob=* glob* a=`echo a b`" */
336 //#define CMD_SINGLEWORD_NOGLOB_COND 3
337 // It is hard to implement correctly, it adds significant amounts of tricky code,
338 // and all this is only useful for really obscure export statements
339 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
340 // guards the code which implements it, but I have doubts it works
341 // in all cases (especially with mixed globbed/non-globbed arguments)
343 #if ENABLE_HUSH_FUNCTIONS
344 # define CMD_FUNCDEF 3
347 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
350 char *group_as_string;
352 #if ENABLE_HUSH_FUNCTIONS
353 struct function *child_func;
354 /* This field is used to prevent a bug here:
355 * while...do f1() {a;}; f1; f1() {b;}; f1; done
356 * When we execute "f1() {a;}" cmd, we create new function and clear
357 * cmd->group, cmd->group_as_string, cmd->argv[0].
358 * When we execute "f1() {b;}", we notice that f1 exists,
359 * and that its "parent cmd" struct is still "alive",
360 * we put those fields back into cmd->xxx
361 * (struct function has ->parent_cmd ptr to facilitate that).
362 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
363 * Without this trick, loop would execute a;b;b;b;...
364 * instead of correct sequence a;b;a;b;...
365 * When command is freed, it severs the link
366 * (sets ->child_func->parent_cmd to NULL).
369 char **argv; /* command name and arguments */
370 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
371 * and on execution these are substituted with their values.
372 * Substitution can make _several_ words out of one argv[n]!
373 * Example: argv[0]=='.^C*^C.' here: echo .$*.
374 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
376 struct redir_struct *redirects; /* I/O redirections */
378 /* Is there anything in this command at all? */
379 #define IS_NULL_CMD(cmd) \
380 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
385 int num_cmds; /* total number of commands in pipe */
386 int alive_cmds; /* number of commands running (not exited) */
387 int stopped_cmds; /* number of commands alive, but stopped */
389 int jobid; /* job number */
390 pid_t pgrp; /* process group ID for the job */
391 char *cmdtext; /* name of job */
393 struct command *cmds; /* array of commands in pipe */
394 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
395 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
396 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
398 typedef enum pipe_style {
404 /* Is there anything in this pipe at all? */
405 #define IS_NULL_PIPE(pi) \
406 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
408 /* This holds pointers to the various results of parsing */
409 struct parse_context {
410 /* linked list of pipes */
411 struct pipe *list_head;
412 /* last pipe (being constructed right now) */
414 /* last command in pipe (being constructed right now) */
415 struct command *command;
416 /* last redirect in command->redirects list */
417 struct redir_struct *pending_redirect;
423 smallint ctx_inverted; /* "! cmd | cmd" */
425 smallint ctx_dsemicolon; /* ";;" seen */
427 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
429 /* group we are enclosed in:
430 * example: "if pipe1; pipe2; then pipe3; fi"
431 * when we see "if" or "then", we malloc and copy current context,
432 * and make ->stack point to it. then we parse pipeN.
433 * when closing "then" / fi" / whatever is found,
434 * we move list_head into ->stack->command->group,
435 * copy ->stack into current context, and delete ->stack.
436 * (parsing of { list } and ( list ) doesn't use this method)
438 struct parse_context *stack;
442 /* On program start, environ points to initial environment.
443 * putenv adds new pointers into it, unsetenv removes them.
444 * Neither of these (de)allocates the strings.
445 * setenv allocates new strings in malloc space and does putenv,
446 * and thus setenv is unusable (leaky) for shell's purposes */
447 #define setenv(...) setenv_is_leaky_dont_use()
449 struct variable *next;
450 char *varstr; /* points to "name=" portion */
451 #if ENABLE_HUSH_LOCAL
452 unsigned func_nest_level;
454 int max_len; /* if > 0, name is part of initial env; else name is malloced */
455 smallint flg_export; /* putenv should be done on this var */
456 smallint flg_read_only;
464 #if ENABLE_HUSH_FUNCTIONS
466 struct function *next;
468 struct command *parent_cmd;
471 char *body_as_string;
477 /* "Globals" within this file */
478 /* Sorted roughly by size (smaller offsets == smaller code) */
480 /* interactive_fd != 0 means we are an interactive shell.
481 * If we are, then saved_tty_pgrp can also be != 0, meaning
482 * that controlling tty is available. With saved_tty_pgrp == 0,
483 * job control still works, but terminal signals
484 * (^C, ^Z, ^Y, ^\) won't work at all, and background
485 * process groups can only be created with "cmd &".
486 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
487 * to give tty to the foreground process group,
488 * and will take it back when the group is stopped (^Z)
491 #if ENABLE_HUSH_INTERACTIVE
492 /* 'interactive_fd' is a fd# open to ctty, if we have one
493 * _AND_ if we decided to act interactively */
497 # define G_interactive_fd (G.interactive_fd)
499 # define G_interactive_fd 0
501 #if ENABLE_FEATURE_EDITING
502 line_input_t *line_input_state;
507 #if ENABLE_HUSH_RANDOM_SUPPORT
513 pid_t saved_tty_pgrp;
514 struct pipe *job_list;
515 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
517 # define G_saved_tty_pgrp 0
519 smallint flag_SIGINT;
520 #if ENABLE_HUSH_LOOPS
521 smallint flag_break_continue;
523 #if ENABLE_HUSH_FUNCTIONS
524 /* 0: outside of a function (or sourced file)
525 * -1: inside of a function, ok to use return builtin
526 * 1: return is invoked, skip all till end of func
528 smallint flag_return_in_progress;
531 smallint exiting; /* used to prevent EXIT trap recursion */
532 /* These four support $?, $#, and $1 */
533 smalluint last_exitcode;
534 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
535 smalluint global_args_malloced;
536 smalluint inherited_set_is_saved;
537 /* how many non-NULL argv's we have. NB: $# + 1 */
541 char *argv0_for_re_execing;
543 #if ENABLE_HUSH_LOOPS
544 unsigned depth_break_continue;
545 unsigned depth_of_loop;
549 struct variable *top_var; /* = &G.shell_ver (set in main()) */
550 struct variable shell_ver;
551 #if ENABLE_HUSH_FUNCTIONS
552 struct function *top_func;
553 # if ENABLE_HUSH_LOCAL
554 struct variable **shadowed_vars_pp;
555 unsigned func_nest_level;
558 /* Signal and trap handling */
560 unsigned count_SIGCHLD;
561 unsigned handled_SIGCHLD;
562 smallint we_have_children;
564 /* which signals have non-DFL handler (even with no traps set)? */
565 unsigned non_DFL_mask;
566 char **traps; /* char *traps[NSIG] */
567 sigset_t blocked_set;
568 sigset_t inherited_set;
570 unsigned long memleak_value;
573 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
575 #define G (*ptr_to_globals)
576 /* Not #defining name to G.name - this quickly gets unwieldy
577 * (too many defines). Also, I actually prefer to see when a variable
578 * is global, thus "G." prefix is a useful hint */
579 #define INIT_G() do { \
580 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
584 /* Function prototypes for builtins */
585 static int builtin_cd(char **argv) FAST_FUNC;
586 static int builtin_echo(char **argv) FAST_FUNC;
587 static int builtin_eval(char **argv) FAST_FUNC;
588 static int builtin_exec(char **argv) FAST_FUNC;
589 static int builtin_exit(char **argv) FAST_FUNC;
590 static int builtin_export(char **argv) FAST_FUNC;
592 static int builtin_fg_bg(char **argv) FAST_FUNC;
593 static int builtin_jobs(char **argv) FAST_FUNC;
596 static int builtin_help(char **argv) FAST_FUNC;
598 #if ENABLE_HUSH_LOCAL
599 static int builtin_local(char **argv) FAST_FUNC;
602 static int builtin_memleak(char **argv) FAST_FUNC;
605 static int builtin_printf(char **argv) FAST_FUNC;
607 static int builtin_pwd(char **argv) FAST_FUNC;
608 static int builtin_read(char **argv) FAST_FUNC;
609 static int builtin_set(char **argv) FAST_FUNC;
610 static int builtin_shift(char **argv) FAST_FUNC;
611 static int builtin_source(char **argv) FAST_FUNC;
612 static int builtin_test(char **argv) FAST_FUNC;
613 static int builtin_trap(char **argv) FAST_FUNC;
614 static int builtin_type(char **argv) FAST_FUNC;
615 static int builtin_true(char **argv) FAST_FUNC;
616 static int builtin_umask(char **argv) FAST_FUNC;
617 static int builtin_unset(char **argv) FAST_FUNC;
618 static int builtin_wait(char **argv) FAST_FUNC;
619 #if ENABLE_HUSH_LOOPS
620 static int builtin_break(char **argv) FAST_FUNC;
621 static int builtin_continue(char **argv) FAST_FUNC;
623 #if ENABLE_HUSH_FUNCTIONS
624 static int builtin_return(char **argv) FAST_FUNC;
627 /* Table of built-in functions. They can be forked or not, depending on
628 * context: within pipes, they fork. As simple commands, they do not.
629 * When used in non-forking context, they can change global variables
630 * in the parent shell process. If forked, of course they cannot.
631 * For example, 'unset foo | whatever' will parse and run, but foo will
632 * still be set at the end. */
633 struct built_in_command {
635 int (*b_function)(char **argv) FAST_FUNC;
638 # define BLTIN(cmd, func, help) { cmd, func, help }
640 # define BLTIN(cmd, func, help) { cmd, func }
644 static const struct built_in_command bltins1[] = {
645 BLTIN("." , builtin_source , "Run commands in a file"),
646 BLTIN(":" , builtin_true , NULL),
648 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
650 #if ENABLE_HUSH_LOOPS
651 BLTIN("break" , builtin_break , "Exit from a loop"),
653 BLTIN("cd" , builtin_cd , "Change directory"),
654 #if ENABLE_HUSH_LOOPS
655 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
657 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
658 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
659 BLTIN("exit" , builtin_exit , "Exit"),
660 BLTIN("export" , builtin_export , "Set environment variables"),
662 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
665 BLTIN("help" , builtin_help , NULL),
668 BLTIN("jobs" , builtin_jobs , "List jobs"),
670 #if ENABLE_HUSH_LOCAL
671 BLTIN("local" , builtin_local , "Set local variables"),
674 BLTIN("memleak" , builtin_memleak , NULL),
676 BLTIN("read" , builtin_read , "Input into variable"),
677 #if ENABLE_HUSH_FUNCTIONS
678 BLTIN("return" , builtin_return , "Return from a function"),
680 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
681 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
682 #if ENABLE_HUSH_BASH_COMPAT
683 BLTIN("source" , builtin_source , "Run commands in a file"),
685 BLTIN("trap" , builtin_trap , "Trap signals"),
686 BLTIN("type" , builtin_type , "Show command type"),
687 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
688 BLTIN("umask" , builtin_umask , "Set file creation mask"),
689 BLTIN("unset" , builtin_unset , "Unset variables"),
690 BLTIN("wait" , builtin_wait , "Wait for process"),
692 /* For now, echo and test are unconditionally enabled.
693 * Maybe make it configurable? */
694 static const struct built_in_command bltins2[] = {
695 BLTIN("[" , builtin_test , NULL),
696 BLTIN("echo" , builtin_echo , NULL),
698 BLTIN("printf" , builtin_printf , NULL),
700 BLTIN("pwd" , builtin_pwd , NULL),
701 BLTIN("test" , builtin_test , NULL),
708 /* prevent disasters with G.debug_indent < 0 */
709 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
710 # define debug_enter() (G.debug_indent++)
711 # define debug_leave() (G.debug_indent--)
713 # define indent() ((void)0)
714 # define debug_enter() ((void)0)
715 # define debug_leave() ((void)0)
719 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
722 #ifndef debug_printf_parse
723 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
726 #ifndef debug_printf_exec
727 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
730 #ifndef debug_printf_env
731 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
734 #ifndef debug_printf_jobs
735 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
736 # define DEBUG_JOBS 1
738 # define DEBUG_JOBS 0
741 #ifndef debug_printf_expand
742 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
743 # define DEBUG_EXPAND 1
745 # define DEBUG_EXPAND 0
748 #ifndef debug_printf_varexp
749 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
752 #ifndef debug_printf_glob
753 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
754 # define DEBUG_GLOB 1
756 # define DEBUG_GLOB 0
759 #ifndef debug_printf_list
760 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
763 #ifndef debug_printf_subst
764 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
767 #ifndef debug_printf_clean
768 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
769 # define DEBUG_CLEAN 1
771 # define DEBUG_CLEAN 0
775 static void debug_print_strings(const char *prefix, char **vv)
778 fprintf(stderr, "%s:\n", prefix);
780 fprintf(stderr, " '%s'\n", *vv++);
783 # define debug_print_strings(prefix, vv) ((void)0)
787 /* Leak hunting. Use hush_leaktool.sh for post-processing.
790 static void *xxmalloc(int lineno, size_t size)
792 void *ptr = xmalloc((size + 0xff) & ~0xff);
793 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
796 static void *xxrealloc(int lineno, void *ptr, size_t size)
798 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
799 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
802 static char *xxstrdup(int lineno, const char *str)
804 char *ptr = xstrdup(str);
805 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
808 static void xxfree(void *ptr)
810 fdprintf(2, "free %p\n", ptr);
813 # define xmalloc(s) xxmalloc(__LINE__, s)
814 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
815 # define xstrdup(s) xxstrdup(__LINE__, s)
816 # define free(p) xxfree(p)
820 /* Syntax and runtime errors. They always abort scripts.
821 * In interactive use they usually discard unparsed and/or unexecuted commands
822 * and return to the prompt.
823 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
826 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
827 # define syntax_error(lineno, msg) syntax_error(msg)
828 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
829 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
830 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
831 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
834 static void die_if_script(unsigned lineno, const char *fmt, ...)
839 bb_error_msg("hush.c:%u", lineno);
842 bb_verror_msg(fmt, p, NULL);
844 if (!G_interactive_fd)
848 static void syntax_error(unsigned lineno, const char *msg)
851 die_if_script(lineno, "syntax error: %s", msg);
853 die_if_script(lineno, "syntax error", NULL);
856 static void syntax_error_at(unsigned lineno, const char *msg)
858 die_if_script(lineno, "syntax error at '%s'", msg);
861 static void syntax_error_unterm_str(unsigned lineno, const char *s)
863 die_if_script(lineno, "syntax error: unterminated %s", s);
866 /* It so happens that all such cases are totally fatal
867 * even if shell is interactive: EOF while looking for closing
868 * delimiter. There is nowhere to read stuff from after that,
869 * it's EOF! The only choice is to terminate.
871 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
872 static void syntax_error_unterm_ch(unsigned lineno, char ch)
874 char msg[2] = { ch, '\0' };
875 syntax_error_unterm_str(lineno, msg);
879 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
884 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
888 # undef die_if_script
890 # undef syntax_error_at
891 # undef syntax_error_unterm_ch
892 # undef syntax_error_unterm_str
893 # undef syntax_error_unexpected_ch
895 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
896 # define syntax_error(msg) syntax_error(__LINE__, msg)
897 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
898 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
899 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
900 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
904 #if ENABLE_HUSH_INTERACTIVE
905 static void cmdedit_update_prompt(void);
907 # define cmdedit_update_prompt() ((void)0)
913 /* Replace each \x with x in place, return ptr past NUL. */
914 static char *unbackslash(char *src)
916 char *dst = src = strchrnul(src, '\\');
920 if ((*dst++ = *src++) == '\0')
926 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
947 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
948 v[count1 + count2] = NULL;
951 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
955 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
957 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
958 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
961 #define add_strings_to_strings(strings, add, need_to_dup) \
962 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
965 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
966 static char **add_string_to_strings(char **strings, char *add)
971 return add_strings_to_strings(strings, v, /*dup:*/ 0);
974 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
976 char **ptr = add_string_to_strings(strings, add);
977 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
980 #define add_string_to_strings(strings, add) \
981 xx_add_string_to_strings(__LINE__, strings, add)
984 static void free_strings(char **strings)
999 /* Helpers for setting new $n and restoring them back
1001 typedef struct save_arg_t {
1005 smallint sv_g_malloced;
1008 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1012 sv->sv_argv0 = argv[0];
1013 sv->sv_g_argv = G.global_argv;
1014 sv->sv_g_argc = G.global_argc;
1015 sv->sv_g_malloced = G.global_args_malloced;
1017 argv[0] = G.global_argv[0]; /* retain $0 */
1018 G.global_argv = argv;
1019 G.global_args_malloced = 0;
1027 static void restore_G_args(save_arg_t *sv, char **argv)
1031 if (G.global_args_malloced) {
1032 /* someone ran "set -- arg1 arg2 ...", undo */
1034 while (*++pp) /* note: does not free $0 */
1036 free(G.global_argv);
1038 argv[0] = sv->sv_argv0;
1039 G.global_argv = sv->sv_g_argv;
1040 G.global_argc = sv->sv_g_argc;
1041 G.global_args_malloced = sv->sv_g_malloced;
1045 /* Basic theory of signal handling in shell
1046 * ========================================
1047 * This does not describe what hush does, rather, it is current understanding
1048 * what it _should_ do. If it doesn't, it's a bug.
1049 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1051 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1052 * is finished or backgrounded. It is the same in interactive and
1053 * non-interactive shells, and is the same regardless of whether
1054 * a user trap handler is installed or a shell special one is in effect.
1055 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1056 * backgrounds (i.e. stops) or kills all members of currently running
1059 * Wait builtin in interruptible by signals for which user trap is set
1060 * or by SIGINT in interactive shell.
1062 * Trap handlers will execute even within trap handlers. (right?)
1064 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1065 * except for handlers set to '' (empty string).
1067 * If job control is off, backgrounded commands ("cmd &")
1068 * have SIGINT, SIGQUIT set to SIG_IGN.
1070 * Commands which are run in command substitution ("`cmd`")
1071 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1073 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1074 * by the shell from its parent.
1076 * Signals which differ from SIG_DFL action
1077 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1080 * SIGTERM (interactive): ignore
1081 * SIGHUP (interactive):
1082 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1083 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1084 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1085 * that all pipe members are stopped. Try this in bash:
1086 * while :; do :; done - ^Z does not background it
1087 * (while :; do :; done) - ^Z backgrounds it
1088 * SIGINT (interactive): wait for last pipe, ignore the rest
1089 * of the command line, show prompt. NB: ^C does not send SIGINT
1090 * to interactive shell while shell is waiting for a pipe,
1091 * since shell is bg'ed (is not in foreground process group).
1092 * Example 1: this waits 5 sec, but does not execute ls:
1093 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1094 * Example 2: this does not wait and does not execute ls:
1095 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1096 * Example 3: this does not wait 5 sec, but executes ls:
1097 * "sleep 5; ls -l" + press ^C
1099 * (What happens to signals which are IGN on shell start?)
1100 * (What happens with signal mask on shell start?)
1102 * Implementation in hush
1103 * ======================
1104 * We use in-kernel pending signal mask to determine which signals were sent.
1105 * We block all signals which we don't want to take action immediately,
1106 * i.e. we block all signals which need to have special handling as described
1107 * above, and all signals which have traps set.
1108 * After each pipe execution, we extract any pending signals via sigtimedwait()
1111 * unsigned non_DFL_mask: a mask of such "special" signals
1112 * sigset_t blocked_set: current blocked signal set
1115 * clear bit in blocked_set unless it is also in non_DFL_mask
1116 * "trap 'cmd' SIGxxx":
1117 * set bit in blocked_set (even if 'cmd' is '')
1118 * after [v]fork, if we plan to be a shell:
1119 * unblock signals with special interactive handling
1120 * (child shell is not interactive),
1121 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1122 * after [v]fork, if we plan to exec:
1123 * POSIX says fork clears pending signal mask in child - no need to clear it.
1124 * Restore blocked signal set to one inherited by shell just prior to exec.
1126 * Note: as a result, we do not use signal handlers much. The only uses
1127 * are to count SIGCHLDs
1128 * and to restore tty pgrp on signal-induced exit.
1131 * Standard says "When a subshell is entered, traps that are not being ignored
1132 * are set to the default actions". bash interprets it so that traps which
1133 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1136 SPECIAL_INTERACTIVE_SIGS = 0
1141 SPECIAL_JOB_SIGS = 0
1149 #if ENABLE_HUSH_FAST
1150 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1153 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1159 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1160 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1161 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1162 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1164 /* Restores tty foreground process group, and exits.
1165 * May be called as signal handler for fatal signal
1166 * (will resend signal to itself, producing correct exit state)
1167 * or called directly with -EXITCODE.
1168 * We also call it if xfunc is exiting. */
1169 static void sigexit(int sig) NORETURN;
1170 static void sigexit(int sig)
1172 /* Disable all signals: job control, SIGPIPE, etc. */
1173 sigprocmask_allsigs(SIG_BLOCK);
1175 /* Careful: we can end up here after [v]fork. Do not restore
1176 * tty pgrp then, only top-level shell process does that */
1177 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1178 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1180 /* Not a signal, just exit */
1184 kill_myself_with_sig(sig); /* does not return */
1188 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1189 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1193 /* Restores tty foreground process group, and exits. */
1194 static void hush_exit(int exitcode) NORETURN;
1195 static void hush_exit(int exitcode)
1197 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1198 /* Prevent recursion:
1199 * trap "echo Hi; exit" EXIT; exit
1201 char *argv[] = { NULL, G.traps[0], NULL };
1210 sigexit(- (exitcode & 0xff));
1216 static int check_and_run_traps(int sig)
1218 static const struct timespec zero_timespec;
1219 smalluint save_rcode;
1225 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1230 if (G.traps && G.traps[sig]) {
1231 if (G.traps[sig][0]) {
1232 /* We have user-defined handler */
1233 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1234 save_rcode = G.last_exitcode;
1237 G.last_exitcode = save_rcode;
1238 } /* else: "" trap, ignoring signal */
1241 /* not a trap: special action */
1243 #if ENABLE_HUSH_FAST
1246 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1250 /* Builtin was ^C'ed, make it look prettier: */
1257 /* bash is observed to signal whole process groups,
1258 * not individual processes */
1259 for (job = G.job_list; job; job = job->next) {
1262 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1263 if (kill(- job->pgrp, SIGHUP) == 0)
1264 kill(- job->pgrp, SIGCONT);
1269 default: /* ignored: */
1270 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1278 static const char *get_cwd(int force)
1280 if (force || G.cwd == NULL) {
1281 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1282 * we must not try to free(bb_msg_unknown) */
1283 if (G.cwd == bb_msg_unknown)
1285 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1287 G.cwd = bb_msg_unknown;
1294 * Shell and environment variable support
1296 static struct variable **get_ptr_to_local_var(const char *name)
1298 struct variable **pp;
1299 struct variable *cur;
1304 while ((cur = *pp) != NULL) {
1305 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1312 static struct variable *get_local_var(const char *name)
1314 struct variable **pp = get_ptr_to_local_var(name);
1320 static const char* FAST_FUNC get_local_var_value(const char *name)
1322 struct variable **pp = get_ptr_to_local_var(name);
1324 return strchr((*pp)->varstr, '=') + 1;
1325 if (strcmp(name, "PPID") == 0)
1326 return utoa(G.root_ppid);
1327 // bash compat: UID? EUID?
1328 #if ENABLE_HUSH_RANDOM_SUPPORT
1329 if (strcmp(name, "RANDOM") == 0) {
1330 return utoa(next_random(&G.random_gen));
1336 /* str holds "NAME=VAL" and is expected to be malloced.
1337 * We take ownership of it.
1339 * 0: do not change export flag
1340 * (if creating new variable, flag will be 0)
1341 * 1: set export flag and putenv the variable
1342 * -1: clear export flag and unsetenv the variable
1343 * flg_read_only is set only when we handle -R var=val
1345 #if !BB_MMU && ENABLE_HUSH_LOCAL
1346 /* all params are used */
1347 #elif BB_MMU && ENABLE_HUSH_LOCAL
1348 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1349 set_local_var(str, flg_export, local_lvl)
1350 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1351 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1352 set_local_var(str, flg_export)
1353 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1354 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1355 set_local_var(str, flg_export, flg_read_only)
1357 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1359 struct variable **var_pp;
1360 struct variable *cur;
1364 eq_sign = strchr(str, '=');
1365 if (!eq_sign) { /* not expected to ever happen? */
1370 name_len = eq_sign - str + 1; /* including '=' */
1371 var_pp = &G.top_var;
1372 while ((cur = *var_pp) != NULL) {
1373 if (strncmp(cur->varstr, str, name_len) != 0) {
1374 var_pp = &cur->next;
1377 /* We found an existing var with this name */
1378 if (cur->flg_read_only) {
1382 bb_error_msg("%s: readonly variable", str);
1386 if (flg_export == -1) { // "&& cur->flg_export" ?
1387 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1392 #if ENABLE_HUSH_LOCAL
1393 if (cur->func_nest_level < local_lvl) {
1394 /* New variable is declared as local,
1395 * and existing one is global, or local
1396 * from enclosing function.
1397 * Remove and save old one: */
1398 *var_pp = cur->next;
1399 cur->next = *G.shadowed_vars_pp;
1400 *G.shadowed_vars_pp = cur;
1401 /* bash 3.2.33(1) and exported vars:
1403 * # f() { local z=a; env | grep ^z; }
1409 if (cur->flg_export)
1414 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1419 if (cur->max_len != 0) {
1420 if (cur->max_len >= strlen(str)) {
1421 /* This one is from startup env, reuse space */
1422 strcpy(cur->varstr, str);
1426 /* max_len == 0 signifies "malloced" var, which we can
1427 * (and has to) free */
1431 goto set_str_and_exp;
1434 /* Not found - create new variable struct */
1435 cur = xzalloc(sizeof(*cur));
1436 #if ENABLE_HUSH_LOCAL
1437 cur->func_nest_level = local_lvl;
1439 cur->next = *var_pp;
1445 cur->flg_read_only = flg_read_only;
1448 if (flg_export == 1)
1449 cur->flg_export = 1;
1450 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1451 cmdedit_update_prompt();
1452 if (cur->flg_export) {
1453 if (flg_export == -1) {
1454 cur->flg_export = 0;
1455 /* unsetenv was already done */
1457 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1458 return putenv(cur->varstr);
1464 /* Used at startup and after each cd */
1465 static void set_pwd_var(int exp)
1467 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1468 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1471 static int unset_local_var_len(const char *name, int name_len)
1473 struct variable *cur;
1474 struct variable **var_pp;
1477 return EXIT_SUCCESS;
1478 var_pp = &G.top_var;
1479 while ((cur = *var_pp) != NULL) {
1480 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1481 if (cur->flg_read_only) {
1482 bb_error_msg("%s: readonly variable", name);
1483 return EXIT_FAILURE;
1485 *var_pp = cur->next;
1486 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1487 bb_unsetenv(cur->varstr);
1488 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1489 cmdedit_update_prompt();
1493 return EXIT_SUCCESS;
1495 var_pp = &cur->next;
1497 return EXIT_SUCCESS;
1500 static int unset_local_var(const char *name)
1502 return unset_local_var_len(name, strlen(name));
1505 static void unset_vars(char **strings)
1513 const char *eq = strchrnul(*v, '=');
1514 unset_local_var_len(*v, (int)(eq - *v));
1520 #if ENABLE_SH_MATH_SUPPORT
1521 # define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1522 # define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1523 static char* FAST_FUNC endofname(const char *name)
1531 if (!is_in_name(*p))
1538 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1540 char *var = xasprintf("%s=%s", name, val);
1541 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1546 * Helpers for "var1=val1 var2=val2 cmd" feature
1548 static void add_vars(struct variable *var)
1550 struct variable *next;
1554 var->next = G.top_var;
1556 if (var->flg_export) {
1557 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1558 putenv(var->varstr);
1560 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1566 static struct variable *set_vars_and_save_old(char **strings)
1569 struct variable *old = NULL;
1575 struct variable *var_p;
1576 struct variable **var_pp;
1579 eq = strchr(*s, '=');
1582 var_pp = get_ptr_to_local_var(*s);
1585 /* Remove variable from global linked list */
1587 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1588 *var_pp = var_p->next;
1589 /* Add it to returned list */
1593 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1604 static int FAST_FUNC static_get(struct in_str *i)
1614 static int FAST_FUNC static_peek(struct in_str *i)
1619 #if ENABLE_HUSH_INTERACTIVE
1621 static void cmdedit_update_prompt(void)
1623 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1624 G.PS1 = get_local_var_value("PS1");
1627 G.PS2 = get_local_var_value("PS2");
1635 static const char* setup_prompt_string(int promptmode)
1637 const char *prompt_str;
1638 debug_printf("setup_prompt_string %d ", promptmode);
1639 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1640 /* Set up the prompt */
1641 if (promptmode == 0) { /* PS1 */
1643 /* bash uses $PWD value, even if it is set by user.
1644 * It uses current dir only if PWD is unset.
1645 * We always use current dir. */
1646 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1651 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1652 debug_printf("result '%s'\n", prompt_str);
1656 static void get_user_input(struct in_str *i)
1659 const char *prompt_str;
1661 prompt_str = setup_prompt_string(i->promptmode);
1662 # if ENABLE_FEATURE_EDITING
1663 /* Enable command line editing only while a command line
1664 * is actually being read */
1667 /* buglet: SIGINT will not make new prompt to appear _at once_,
1668 * only after <Enter>. (^C will work) */
1669 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1670 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1671 check_and_run_traps(0);
1672 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1673 i->eof_flag = (r < 0);
1674 if (i->eof_flag) { /* EOF/error detected */
1675 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1676 G.user_input_buf[1] = '\0';
1681 fputs(prompt_str, stdout);
1683 G.user_input_buf[0] = r = fgetc(i->file);
1684 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1685 //do we need check_and_run_traps(0)? (maybe only if stdin)
1686 } while (G.flag_SIGINT);
1687 i->eof_flag = (r == EOF);
1689 i->p = G.user_input_buf;
1692 #endif /* INTERACTIVE */
1694 /* This is the magic location that prints prompts
1695 * and gets data back from the user */
1696 static int FAST_FUNC file_get(struct in_str *i)
1700 /* If there is data waiting, eat it up */
1701 if (i->p && *i->p) {
1702 #if ENABLE_HUSH_INTERACTIVE
1706 if (i->eof_flag && !*i->p)
1708 /* note: ch is never NUL */
1710 /* need to double check i->file because we might be doing something
1711 * more complicated by now, like sourcing or substituting. */
1712 #if ENABLE_HUSH_INTERACTIVE
1713 if (G_interactive_fd && i->promptme && i->file == stdin) {
1716 } while (!*i->p); /* need non-empty line */
1717 i->promptmode = 1; /* PS2 */
1722 do ch = fgetc(i->file); while (ch == '\0');
1724 debug_printf("file_get: got '%c' %d\n", ch, ch);
1725 #if ENABLE_HUSH_INTERACTIVE
1732 /* All callers guarantee this routine will never
1733 * be used right after a newline, so prompting is not needed.
1735 static int FAST_FUNC file_peek(struct in_str *i)
1738 if (i->p && *i->p) {
1739 if (i->eof_flag && !i->p[1])
1742 /* note: ch is never NUL */
1744 do ch = fgetc(i->file); while (ch == '\0');
1745 i->eof_flag = (ch == EOF);
1746 i->peek_buf[0] = ch;
1747 i->peek_buf[1] = '\0';
1749 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1753 static void setup_file_in_str(struct in_str *i, FILE *f)
1755 i->peek = file_peek;
1757 #if ENABLE_HUSH_INTERACTIVE
1759 i->promptmode = 0; /* PS1 */
1765 static void setup_string_in_str(struct in_str *i, const char *s)
1767 i->peek = static_peek;
1768 i->get = static_get;
1769 #if ENABLE_HUSH_INTERACTIVE
1771 i->promptmode = 0; /* PS1 */
1781 #define B_CHUNK (32 * sizeof(char*))
1783 static void o_reset_to_empty_unquoted(o_string *o)
1791 static void o_free(o_string *o)
1794 memset(o, 0, sizeof(*o));
1797 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1802 static void o_grow_by(o_string *o, int len)
1804 if (o->length + len > o->maxlen) {
1805 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1806 o->data = xrealloc(o->data, 1 + o->maxlen);
1810 static void o_addchr(o_string *o, int ch)
1812 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1814 o->data[o->length] = ch;
1816 o->data[o->length] = '\0';
1819 static void o_addblock(o_string *o, const char *str, int len)
1822 memcpy(&o->data[o->length], str, len);
1824 o->data[o->length] = '\0';
1827 static void o_addstr(o_string *o, const char *str)
1829 o_addblock(o, str, strlen(str));
1833 static void nommu_addchr(o_string *o, int ch)
1839 # define nommu_addchr(o, str) ((void)0)
1842 static void o_addstr_with_NUL(o_string *o, const char *str)
1844 o_addblock(o, str, strlen(str) + 1);
1847 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1852 && (*str != '*' && *str != '?' && *str != '[')
1860 #undef HUSH_BRACE_EXP
1862 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1863 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1864 * Apparently, on unquoted $v bash still does globbing
1865 * ("v='*.txt'; echo $v" prints all .txt files),
1866 * but NOT brace expansion! Thus, there should be TWO independent
1867 * quoting mechanisms on $v expansion side: one protects
1868 * $v from brace expansion, and other additionally protects "$v" against globbing.
1869 * We have only second one.
1872 #ifdef HUSH_BRACE_EXP
1873 # define MAYBE_BRACES "{}"
1875 # define MAYBE_BRACES ""
1878 /* My analysis of quoting semantics tells me that state information
1879 * is associated with a destination, not a source.
1881 static void o_addqchr(o_string *o, int ch)
1884 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1889 o->data[o->length] = '\\';
1892 o->data[o->length] = ch;
1894 o->data[o->length] = '\0';
1897 static void o_addQchr(o_string *o, int ch)
1900 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1902 o->data[o->length] = '\\';
1906 o->data[o->length] = ch;
1908 o->data[o->length] = '\0';
1911 static void o_addQstr(o_string *o, const char *str, int len)
1914 o_addblock(o, str, len);
1920 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1921 if (ordinary_cnt > len) /* paranoia */
1923 o_addblock(o, str, ordinary_cnt);
1924 if (ordinary_cnt == len)
1926 str += ordinary_cnt;
1927 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1931 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1933 o->data[o->length] = '\\';
1937 o->data[o->length] = ch;
1939 o->data[o->length] = '\0';
1943 /* A special kind of o_string for $VAR and `cmd` expansion.
1944 * It contains char* list[] at the beginning, which is grown in 16 element
1945 * increments. Actual string data starts at the next multiple of 16 * (char*).
1946 * list[i] contains an INDEX (int!) into this string data.
1947 * It means that if list[] needs to grow, data needs to be moved higher up
1948 * but list[i]'s need not be modified.
1949 * NB: remembering how many list[i]'s you have there is crucial.
1950 * o_finalize_list() operation post-processes this structure - calculates
1951 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1953 #if DEBUG_EXPAND || DEBUG_GLOB
1954 static void debug_print_list(const char *prefix, o_string *o, int n)
1956 char **list = (char**)o->data;
1957 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1961 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1962 prefix, list, n, string_start, o->length, o->maxlen);
1965 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1966 o->data + (int)list[i] + string_start,
1967 o->data + (int)list[i] + string_start);
1971 const char *p = o->data + (int)list[n - 1] + string_start;
1973 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1977 # define debug_print_list(prefix, o, n) ((void)0)
1980 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1981 * in list[n] so that it points past last stored byte so far.
1982 * It returns n+1. */
1983 static int o_save_ptr_helper(o_string *o, int n)
1985 char **list = (char**)o->data;
1989 if (!o->has_empty_slot) {
1990 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1991 string_len = o->length - string_start;
1992 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1993 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1994 /* list[n] points to string_start, make space for 16 more pointers */
1995 o->maxlen += 0x10 * sizeof(list[0]);
1996 o->data = xrealloc(o->data, o->maxlen + 1);
1997 list = (char**)o->data;
1998 memmove(list + n + 0x10, list + n, string_len);
1999 o->length += 0x10 * sizeof(list[0]);
2001 debug_printf_list("list[%d]=%d string_start=%d\n",
2002 n, string_len, string_start);
2005 /* We have empty slot at list[n], reuse without growth */
2006 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2007 string_len = o->length - string_start;
2008 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2009 n, string_len, string_start);
2010 o->has_empty_slot = 0;
2012 list[n] = (char*)(ptrdiff_t)string_len;
2016 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2017 static int o_get_last_ptr(o_string *o, int n)
2019 char **list = (char**)o->data;
2020 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2022 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2025 #ifdef HUSH_BRACE_EXP
2026 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2027 * first, it processes even {a} (no commas), second,
2028 * I didn't manage to make it return strings when they don't match
2029 * existing files. Need to re-implement it.
2033 static int glob_needed(const char *s)
2042 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2048 /* Return pointer to next closing brace or to comma */
2049 static const char *next_brace_sub(const char *cp)
2053 while (*cp != '\0') {
2060 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2062 if (*cp++ == '{') /*}*/
2066 return *cp != '\0' ? cp : NULL;
2068 /* Recursive brace globber. Note: may garble pattern[]. */
2069 static int glob_brace(char *pattern, o_string *o, int n)
2071 char *new_pattern_buf;
2078 debug_printf_glob("glob_brace('%s')\n", pattern);
2084 if (*begin == '{') /*}*/ {
2085 /* Find the first sub-pattern and at the same time
2086 * find the rest after the closing brace */
2087 next = next_brace_sub(begin);
2089 /* An illegal expression */
2092 /*{*/ if (*next == '}') {
2093 /* "{abc}" with no commas - illegal
2094 * brace expr, disregard and skip it */
2100 if (*begin == '\\' && begin[1] != '\0')
2104 debug_printf_glob("begin:%s\n", begin);
2105 debug_printf_glob("next:%s\n", next);
2107 /* Now find the end of the whole brace expression */
2109 /*{*/ while (*rest != '}') {
2110 rest = next_brace_sub(rest);
2112 /* An illegal expression */
2115 debug_printf_glob("rest:%s\n", rest);
2117 rest_len = strlen(++rest) + 1;
2119 /* We are sure the brace expression is well-formed */
2121 /* Allocate working buffer large enough for our work */
2122 new_pattern_buf = xmalloc(strlen(pattern));
2124 /* We have a brace expression. BEGIN points to the opening {,
2125 * NEXT points past the terminator of the first element, and REST
2126 * points past the final }. We will accumulate result names from
2127 * recursive runs for each brace alternative in the buffer using
2132 /* Construct the new glob expression */
2135 mempcpy(new_pattern_buf,
2136 /* We know the prefix for all sub-patterns */
2137 pattern, begin - pattern),
2141 /* Note: glob_brace() may garble new_pattern_buf[].
2142 * That's why we re-copy prefix every time (1st memcpy above).
2144 n = glob_brace(new_pattern_buf, o, n);
2145 /*{*/ if (*next == '}') {
2146 /* We saw the last entry */
2150 next = next_brace_sub(next);
2152 free(new_pattern_buf);
2160 memset(&globdata, 0, sizeof(globdata));
2161 gr = glob(pattern, 0, NULL, &globdata);
2162 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2164 if (gr == GLOB_NOMATCH) {
2165 globfree(&globdata);
2166 /* NB: garbles parameter */
2167 unbackslash(pattern);
2168 o_addstr_with_NUL(o, pattern);
2169 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2170 return o_save_ptr_helper(o, n);
2172 if (gr == GLOB_NOSPACE)
2173 bb_error_msg_and_die(bb_msg_memory_exhausted);
2174 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2175 * but we didn't specify it. Paranoia again. */
2176 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2178 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2179 char **argv = globdata.gl_pathv;
2181 o_addstr_with_NUL(o, *argv);
2182 n = o_save_ptr_helper(o, n);
2188 globfree(&globdata);
2192 /* Performs globbing on last list[],
2193 * saving each result as a new list[].
2195 static int o_glob(o_string *o, int n)
2197 char *pattern, *copy;
2199 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2201 return o_save_ptr_helper(o, n);
2202 pattern = o->data + o_get_last_ptr(o, n);
2203 debug_printf_glob("glob pattern '%s'\n", pattern);
2204 if (!glob_needed(pattern)) {
2205 /* unbackslash last string in o in place, fix length */
2206 o->length = unbackslash(pattern) - o->data;
2207 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2208 return o_save_ptr_helper(o, n);
2211 copy = xstrdup(pattern);
2212 /* "forget" pattern in o */
2213 o->length = pattern - o->data;
2214 n = glob_brace(copy, o, n);
2217 debug_print_list("o_glob returning", o, n);
2221 #else /* !HUSH_BRACE_EXP */
2224 static int glob_needed(const char *s)
2233 if (*s == '*' || *s == '[' || *s == '?')
2239 /* Performs globbing on last list[],
2240 * saving each result as a new list[].
2242 static int o_glob(o_string *o, int n)
2248 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2250 return o_save_ptr_helper(o, n);
2251 pattern = o->data + o_get_last_ptr(o, n);
2252 debug_printf_glob("glob pattern '%s'\n", pattern);
2253 if (!glob_needed(pattern)) {
2255 /* unbackslash last string in o in place, fix length */
2256 o->length = unbackslash(pattern) - o->data;
2257 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2258 return o_save_ptr_helper(o, n);
2261 memset(&globdata, 0, sizeof(globdata));
2262 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2263 * If we glob "*.\*" and don't find anything, we need
2264 * to fall back to using literal "*.*", but GLOB_NOCHECK
2265 * will return "*.\*"!
2267 gr = glob(pattern, 0, NULL, &globdata);
2268 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2270 if (gr == GLOB_NOMATCH) {
2271 globfree(&globdata);
2274 if (gr == GLOB_NOSPACE)
2275 bb_error_msg_and_die(bb_msg_memory_exhausted);
2276 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2277 * but we didn't specify it. Paranoia again. */
2278 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2280 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2281 char **argv = globdata.gl_pathv;
2282 /* "forget" pattern in o */
2283 o->length = pattern - o->data;
2285 o_addstr_with_NUL(o, *argv);
2286 n = o_save_ptr_helper(o, n);
2292 globfree(&globdata);
2294 debug_print_list("o_glob returning", o, n);
2298 #endif /* !HUSH_BRACE_EXP */
2300 /* If o->o_glob == 1, glob the string so far remembered.
2301 * Otherwise, just finish current list[] and start new */
2302 static int o_save_ptr(o_string *o, int n)
2304 if (o->o_glob) { /* if globbing is requested */
2305 /* If o->has_empty_slot, list[n] was already globbed
2306 * (if it was requested back then when it was filled)
2307 * so don't do that again! */
2308 if (!o->has_empty_slot)
2309 return o_glob(o, n); /* o_save_ptr_helper is inside */
2311 return o_save_ptr_helper(o, n);
2314 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2315 static char **o_finalize_list(o_string *o, int n)
2320 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2322 debug_print_list("finalized", o, n);
2323 debug_printf_expand("finalized n:%d\n", n);
2324 list = (char**)o->data;
2325 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2329 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2335 /* Expansion can recurse */
2336 #if ENABLE_HUSH_TICK
2337 static int process_command_subs(o_string *dest, const char *s);
2339 static char *expand_string_to_string(const char *str);
2341 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2342 parse_stream_dquoted(dest, input, dquote_end)
2344 static int parse_stream_dquoted(o_string *as_string,
2346 struct in_str *input,
2349 /* expand_strvec_to_strvec() takes a list of strings, expands
2350 * all variable references within and returns a pointer to
2351 * a list of expanded strings, possibly with larger number
2352 * of strings. (Think VAR="a b"; echo $VAR).
2353 * This new list is allocated as a single malloc block.
2354 * NULL-terminated list of char* pointers is at the beginning of it,
2355 * followed by strings themself.
2356 * Caller can deallocate entire list by single free(list). */
2358 /* Store given string, finalizing the word and starting new one whenever
2359 * we encounter IFS char(s). This is used for expanding variable values.
2360 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2361 static int expand_on_ifs(o_string *output, int n, const char *str)
2364 int word_len = strcspn(str, G.ifs);
2366 if (output->o_escape || !output->o_glob)
2367 o_addQstr(output, str, word_len);
2368 else /* protect backslashes against globbing up :) */
2369 o_addblock_duplicate_backslash(output, str, word_len);
2372 if (!*str) /* EOL - do not finalize word */
2374 o_addchr(output, '\0');
2375 debug_print_list("expand_on_ifs", output, n);
2376 n = o_save_ptr(output, n);
2377 str += strspn(str, G.ifs); /* skip ifs chars */
2379 debug_print_list("expand_on_ifs[1]", output, n);
2383 /* Helper to expand $((...)) and heredoc body. These act as if
2384 * they are in double quotes, with the exception that they are not :).
2385 * Just the rules are similar: "expand only $var and `cmd`"
2387 * Returns malloced string.
2388 * As an optimization, we return NULL if expansion is not needed.
2390 static char *expand_pseudo_dquoted(const char *str)
2393 struct in_str input;
2394 o_string dest = NULL_O_STRING;
2396 if (strchr(str, '$') == NULL
2397 #if ENABLE_HUSH_TICK
2398 && strchr(str, '`') == NULL
2404 /* We need to expand. Example:
2405 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2407 setup_string_in_str(&input, str);
2408 parse_stream_dquoted(NULL, &dest, &input, EOF);
2409 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2410 exp_str = expand_string_to_string(dest.data);
2411 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2412 o_free_unsafe(&dest);
2416 #if ENABLE_SH_MATH_SUPPORT
2417 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
2419 arith_eval_hooks_t hooks;
2423 hooks.lookupvar = get_local_var_value;
2424 hooks.setvar = set_local_var_from_halves;
2425 hooks.endofname = endofname;
2426 exp_str = expand_pseudo_dquoted(arg);
2427 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
2433 /* Expand all variable references in given string, adding words to list[]
2434 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2435 * to be filled). This routine is extremely tricky: has to deal with
2436 * variables/parameters with whitespace, $* and $@, and constructs like
2437 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2438 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2440 /* or_mask is either 0 (normal case) or 0x80 -
2441 * expansion of right-hand side of assignment == 1-element expand.
2442 * It will also do no globbing, and thus we must not backslash-quote!
2449 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2450 debug_print_list("expand_vars_to_list", output, n);
2451 n = o_save_ptr(output, n);
2452 debug_print_list("expand_vars_to_list[0]", output, n);
2454 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2457 char *to_be_freed = NULL;
2458 const char *val = NULL;
2459 #if ENABLE_HUSH_TICK
2460 o_string subst_result = NULL_O_STRING;
2462 #if ENABLE_SH_MATH_SUPPORT
2463 char arith_buf[sizeof(arith_t)*3 + 2];
2465 o_addblock(output, arg, p - arg);
2466 debug_print_list("expand_vars_to_list[1]", output, n);
2468 p = strchr(p, SPECIAL_VAR_SYMBOL);
2470 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2471 /* "$@" is special. Even if quoted, it can still
2472 * expand to nothing (not even an empty string) */
2473 if ((first_ch & 0x7f) != '@')
2474 ored_ch |= first_ch;
2476 switch (first_ch & 0x7f) {
2477 /* Highest bit in first_ch indicates that var is double-quoted */
2481 if (!G.global_argv[i])
2483 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2484 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2485 smallint sv = output->o_escape;
2486 /* unquoted var's contents should be globbed, so don't escape */
2487 output->o_escape = 0;
2488 while (G.global_argv[i]) {
2489 n = expand_on_ifs(output, n, G.global_argv[i]);
2490 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2491 if (G.global_argv[i++][0] && G.global_argv[i]) {
2492 /* this argv[] is not empty and not last:
2493 * put terminating NUL, start new word */
2494 o_addchr(output, '\0');
2495 debug_print_list("expand_vars_to_list[2]", output, n);
2496 n = o_save_ptr(output, n);
2497 debug_print_list("expand_vars_to_list[3]", output, n);
2500 output->o_escape = sv;
2502 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2503 * and in this case should treat it like '$*' - see 'else...' below */
2504 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2506 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2507 if (++i >= G.global_argc)
2509 o_addchr(output, '\0');
2510 debug_print_list("expand_vars_to_list[4]", output, n);
2511 n = o_save_ptr(output, n);
2513 } else { /* quoted $*: add as one word */
2515 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2516 if (!G.global_argv[++i])
2519 o_addchr(output, G.ifs[0]);
2523 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2524 /* "Empty variable", used to make "" etc to not disappear */
2528 #if ENABLE_HUSH_TICK
2529 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2532 /* Can't just stuff it into output o_string,
2533 * expanded result may need to be globbed
2534 * and $IFS-splitted */
2535 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2536 G.last_exitcode = process_command_subs(&subst_result, arg);
2537 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2538 val = subst_result.data;
2541 #if ENABLE_SH_MATH_SUPPORT
2542 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2546 arg++; /* skip '+' */
2547 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2548 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2549 res = expand_and_evaluate_arith(arg, &errcode);
2552 const char *msg = "error in arithmetic";
2555 msg = "exponent less than 0";
2558 msg = "divide by 0";
2561 msg = "expression recursion loop detected";
2566 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2567 sprintf(arith_buf, arith_t_fmt, res);
2572 default: { /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2576 char exp_save = exp_save; /* for compiler */
2577 char *exp_saveptr; /* points to expansion operator */
2578 char *exp_word = exp_word; /* for compiler */
2582 exp_saveptr = arg[1] ? strchr("%#:-=+?", arg[1]) : NULL;
2583 first_char = arg[0] = first_ch & 0x7f;
2586 if (first_char == '#' && arg[1] && !exp_saveptr) {
2587 /* handle length expansion ${#var} */
2591 /* maybe handle parameter expansion */
2592 if (exp_saveptr /* if 2nd char is one of expansion operators */
2593 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
2595 /* ${?:0}, ${#[:]%0} etc */
2596 exp_saveptr = var + 1;
2598 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
2599 exp_saveptr = var+1 + strcspn(var+1, "%#:-=+?");
2601 exp_op = exp_save = *exp_saveptr;
2603 exp_word = exp_saveptr + 1;
2604 if (exp_op == ':') {
2605 exp_op = *exp_word++;
2606 if (ENABLE_HUSH_BASH_COMPAT
2607 && (exp_op == '\0' || !strchr("%#:-=+?"+3, exp_op))
2609 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
2614 *exp_saveptr = '\0';
2615 } /* else: it's not an expansion op, but bare ${var} */
2618 /* lookup the variable in question */
2619 if (isdigit(var[0])) {
2620 /* parse_dollar() should have vetted var for us */
2622 if (i < G.global_argc)
2623 val = G.global_argv[i];
2624 /* else val remains NULL: $N with too big N */
2628 val = utoa(G.root_pid);
2630 case '!': /* bg pid */
2631 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2633 case '?': /* exitcode */
2634 val = utoa(G.last_exitcode);
2636 case '#': /* argc */
2637 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2640 val = get_local_var_value(var);
2644 /* handle any expansions */
2645 if (exp_op == 'L') {
2646 debug_printf_expand("expand: length(%s)=", val);
2647 val = utoa(val ? strlen(val) : 0);
2648 debug_printf_expand("%s\n", val);
2649 } else if (exp_op) {
2650 if (exp_op == '%' || exp_op == '#') {
2651 /* Standard-mandated substring removal ops:
2652 * ${parameter%word} - remove smallest suffix pattern
2653 * ${parameter%%word} - remove largest suffix pattern
2654 * ${parameter#word} - remove smallest prefix pattern
2655 * ${parameter##word} - remove largest prefix pattern
2657 * Word is expanded to produce a glob pattern.
2658 * Then var's value is matched to it and matching part removed.
2663 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2664 if (exp_op == *exp_word) /* ## or %% */
2666 val = to_be_freed = xstrdup(val);
2668 char *exp_exp_word = expand_pseudo_dquoted(exp_word);
2670 exp_word = exp_exp_word;
2671 loc = scan(to_be_freed, exp_word, match_at_left);
2672 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
2673 // exp_op, to_be_freed, exp_word, loc);
2676 if (loc) { /* match was found */
2677 if (match_at_left) /* # or ## */
2683 } else if (exp_op == ':') {
2684 #if ENABLE_HUSH_BASH_COMPAT
2685 /* It's ${var:N[:M]} bashism.
2686 * Note that in encoded form it has TWO parts:
2687 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
2692 beg = expand_and_evaluate_arith(exp_word, &errcode);
2693 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
2694 *p++ = SPECIAL_VAR_SYMBOL;
2696 p = strchr(p, SPECIAL_VAR_SYMBOL);
2698 len = expand_and_evaluate_arith(exp_word, &errcode);
2699 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
2701 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
2702 if (beg < 0) /* bash compat */
2704 debug_printf_varexp("from val:'%s'\n", val);
2705 if (len == 0 || !val || beg >= strlen(val))
2708 /* Paranoia. What if user entered 9999999999999
2709 * which fits in arith_t but not int? */
2712 val = to_be_freed = xstrndup(val + beg, len);
2714 debug_printf_varexp("val:'%s'\n", val);
2718 die_if_script("malformed ${%s:...}", var);
2721 } else { /* one of "-=+?" */
2722 /* Standard-mandated substitution ops:
2723 * ${var?word} - indicate error if unset
2724 * If var is unset, word (or a message indicating it is unset
2725 * if word is null) is written to standard error
2726 * and the shell exits with a non-zero exit status.
2727 * Otherwise, the value of var is substituted.
2728 * ${var-word} - use default value
2729 * If var is unset, word is substituted.
2730 * ${var=word} - assign and use default value
2731 * If var is unset, word is assigned to var.
2732 * In all cases, final value of var is substituted.
2733 * ${var+word} - use alternative value
2734 * If var is unset, null is substituted.
2735 * Otherwise, word is substituted.
2737 * Word is subjected to tilde expansion, parameter expansion,
2738 * command substitution, and arithmetic expansion.
2739 * If word is not needed, it is not expanded.
2741 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2742 * but also treat null var as if it is unset.
2744 int use_word = (!val || ((exp_save == ':') && !val[0]));
2746 use_word = !use_word;
2747 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2748 (exp_save == ':') ? "true" : "false", use_word);
2750 to_be_freed = expand_pseudo_dquoted(exp_word);
2752 exp_word = to_be_freed;
2753 if (exp_op == '?') {
2754 /* mimic bash message */
2755 die_if_script("%s: %s",
2757 exp_word[0] ? exp_word : "parameter null or not set"
2759 //TODO: how interactive bash aborts expansion mid-command?
2764 if (exp_op == '=') {
2765 /* ${var=[word]} or ${var:=[word]} */
2766 if (isdigit(var[0]) || var[0] == '#') {
2767 /* mimic bash message */
2768 die_if_script("$%s: cannot assign in this way", var);
2771 char *new_var = xasprintf("%s=%s", var, val);
2772 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2776 } /* one of "-=+?" */
2778 *exp_saveptr = exp_save;
2782 #if ENABLE_HUSH_TICK
2785 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2786 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2788 /* unquoted var's contents should be globbed, so don't escape */
2789 smallint sv = output->o_escape;
2790 output->o_escape = 0;
2791 n = expand_on_ifs(output, n, val);
2793 output->o_escape = sv;
2795 } else { /* quoted $VAR, val will be appended below */
2796 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2799 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2802 o_addQstr(output, val, strlen(val));
2805 /* Do the check to avoid writing to a const string */
2806 if (*p != SPECIAL_VAR_SYMBOL)
2807 *p = SPECIAL_VAR_SYMBOL;
2809 #if ENABLE_HUSH_TICK
2810 o_free(&subst_result);
2813 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2816 debug_print_list("expand_vars_to_list[a]", output, n);
2817 /* this part is literal, and it was already pre-quoted
2818 * if needed (much earlier), do not use o_addQstr here! */
2819 o_addstr_with_NUL(output, arg);
2820 debug_print_list("expand_vars_to_list[b]", output, n);
2821 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2822 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2825 /* allow to reuse list[n] later without re-growth */
2826 output->has_empty_slot = 1;
2828 o_addchr(output, '\0');
2833 static char **expand_variables(char **argv, int or_mask)
2838 o_string output = NULL_O_STRING;
2840 if (or_mask & 0x100) {
2841 output.o_escape = 1; /* protect against globbing for "$var" */
2842 /* (unquoted $var will temporarily switch it off) */
2849 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2852 debug_print_list("expand_variables", &output, n);
2854 /* output.data (malloced in one block) gets returned in "list" */
2855 list = o_finalize_list(&output, n);
2856 debug_print_strings("expand_variables[1]", list);
2860 static char **expand_strvec_to_strvec(char **argv)
2862 return expand_variables(argv, 0x100);
2865 #if ENABLE_HUSH_BASH_COMPAT
2866 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2868 return expand_variables(argv, 0x80);
2872 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2873 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2878 o_string output = NULL_O_STRING;
2883 int is_var = is_well_formed_var_name(*v, '=');
2884 /* is_var * 0x80: singleword expansion for vars */
2885 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2887 /* Subtle! expand_vars_to_list did not glob last word yet.
2888 * It does this only when fed with further data.
2889 * Therefore we set globbing flags AFTER it, not before:
2892 /* if it is not recognizably abc=...; then: */
2893 output.o_escape = !is_var; /* protect against globbing for "$var" */
2894 /* (unquoted $var will temporarily switch it off) */
2895 output.o_glob = !is_var; /* and indeed do globbing */
2898 debug_print_list("expand_cond", &output, n);
2900 /* output.data (malloced in one block) gets returned in "list" */
2901 list = o_finalize_list(&output, n);
2902 debug_print_strings("expand_cond[1]", list);
2907 /* Used for expansion of right hand of assignments */
2908 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2910 static char *expand_string_to_string(const char *str)
2912 char *argv[2], **list;
2914 argv[0] = (char*)str;
2916 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2918 if (!list[0] || list[1])
2919 bb_error_msg_and_die("BUG in varexp2");
2920 /* actually, just move string 2*sizeof(char*) bytes back */
2921 overlapping_strcpy((char*)list, list[0]);
2922 unbackslash((char*)list);
2923 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2927 /* Used for "eval" builtin */
2928 static char* expand_strvec_to_string(char **argv)
2932 list = expand_variables(argv, 0x80);
2933 /* Convert all NULs to spaces */
2938 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2939 bb_error_msg_and_die("BUG in varexp3");
2940 /* bash uses ' ' regardless of $IFS contents */
2945 overlapping_strcpy((char*)list, list[0]);
2946 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2950 static char **expand_assignments(char **argv, int count)
2954 /* Expand assignments into one string each */
2955 for (i = 0; i < count; i++) {
2956 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2964 void re_execute_shell(char ***to_free, const char *s,
2965 char *g_argv0, char **g_argv,
2966 char **builtin_argv) NORETURN;
2968 static void reset_traps_to_defaults(void)
2970 /* This function is always called in a child shell
2971 * after fork (not vfork, NOMMU doesn't use this function).
2976 /* Child shells are not interactive.
2977 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2978 * Testcase: (while :; do :; done) + ^Z should background.
2979 * Same goes for SIGTERM, SIGHUP, SIGINT.
2981 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2982 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2984 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2985 * Stupid. It can be done with *single* &= op, but we can't use
2986 * the fact that G.blocked_set is implemented as a bitmask
2988 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2992 /* Careful. Only if no trap or trap is not "" */
2993 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2994 sigdelset(&G.blocked_set, sig);
3001 /* Our homegrown sig mask is saner to work with :) */
3002 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
3004 /* Resetting all traps to default except empty ones */
3005 mask = G.non_DFL_mask;
3006 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
3007 if (!G.traps[sig] || !G.traps[sig][0])
3010 G.traps[sig] = NULL;
3011 /* There is no signal for 0 (EXIT) */
3014 /* There was a trap handler, we just removed it.
3015 * But if sig still has non-DFL handling,
3016 * we should not unblock the sig. */
3019 sigdelset(&G.blocked_set, sig);
3021 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
3026 static void re_execute_shell(char ***to_free, const char *s,
3027 char *g_argv0, char **g_argv,
3028 char **builtin_argv) NORETURN;
3029 static void re_execute_shell(char ***to_free, const char *s,
3030 char *g_argv0, char **g_argv,
3031 char **builtin_argv)
3033 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
3034 /* delims + 2 * (number of bytes in printed hex numbers) */
3035 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
3036 char *heredoc_argv[4];
3037 struct variable *cur;
3038 # if ENABLE_HUSH_FUNCTIONS
3039 struct function *funcp;
3043 unsigned long long empty_trap_mask;
3045 if (!g_argv0) { /* heredoc */
3046 argv = heredoc_argv;
3047 argv[0] = (char *) G.argv0_for_re_execing;
3048 argv[1] = (char *) "-<";
3049 argv[2] = (char *) s;
3051 pp = &argv[3]; /* used as pointer to empty environment */
3057 if (pp) while (*pp++)
3060 empty_trap_mask = 0;
3063 for (sig = 1; sig < NSIG; sig++) {
3064 if (G.traps[sig] && !G.traps[sig][0])
3065 empty_trap_mask |= 1LL << sig;
3069 sprintf(param_buf, NOMMU_HACK_FMT
3070 , (unsigned) G.root_pid
3071 , (unsigned) G.root_ppid
3072 , (unsigned) G.last_bg_pid
3073 , (unsigned) G.last_exitcode
3076 IF_HUSH_LOOPS(, G.depth_of_loop)
3078 # undef NOMMU_HACK_FMT
3079 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3080 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3083 for (cur = G.top_var; cur; cur = cur->next) {
3084 if (!cur->flg_export || cur->flg_read_only)
3087 # if ENABLE_HUSH_FUNCTIONS
3088 for (funcp = G.top_func; funcp; funcp = funcp->next)
3094 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3095 *pp++ = (char *) G.argv0_for_re_execing;
3097 for (cur = G.top_var; cur; cur = cur->next) {
3098 if (cur->varstr == hush_version_str)
3100 if (cur->flg_read_only) {
3101 *pp++ = (char *) "-R";
3102 *pp++ = cur->varstr;
3103 } else if (!cur->flg_export) {
3104 *pp++ = (char *) "-V";
3105 *pp++ = cur->varstr;
3108 # if ENABLE_HUSH_FUNCTIONS
3109 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3110 *pp++ = (char *) "-F";
3111 *pp++ = funcp->name;
3112 *pp++ = funcp->body_as_string;
3115 /* We can pass activated traps here. Say, -Tnn:trap_string
3117 * However, POSIX says that subshells reset signals with traps
3119 * I tested bash-3.2 and it not only does that with true subshells
3120 * of the form ( list ), but with any forked children shells.
3121 * I set trap "echo W" WINCH; and then tried:
3123 * { echo 1; sleep 20; echo 2; } &
3124 * while true; do echo 1; sleep 20; echo 2; break; done &
3125 * true | { echo 1; sleep 20; echo 2; } | cat
3127 * In all these cases sending SIGWINCH to the child shell
3128 * did not run the trap. If I add trap "echo V" WINCH;
3129 * _inside_ group (just before echo 1), it works.
3131 * I conclude it means we don't need to pass active traps here.
3132 * Even if we would use signal handlers instead of signal masking
3133 * in order to implement trap handling,
3134 * exec syscall below resets signals to SIG_DFL for us.
3136 *pp++ = (char *) "-c";
3139 while (*++builtin_argv)
3140 *pp++ = *builtin_argv;
3141 *pp++ = (char *) "";
3146 /* *pp = NULL; - is already there */
3150 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3151 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3152 execve(bb_busybox_exec_path, argv, pp);
3153 /* Fallback. Useful for init=/bin/hush usage etc */
3154 if (argv[0][0] == '/')
3155 execve(argv[0], argv, pp);
3156 xfunc_error_retval = 127;
3157 bb_error_msg_and_die("can't re-execute the shell");
3159 #endif /* !BB_MMU */
3162 static void setup_heredoc(struct redir_struct *redir)
3164 struct fd_pair pair;
3167 /* the _body_ of heredoc (misleading field name) */
3168 const char *heredoc = redir->rd_filename;
3175 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3176 expanded = expand_pseudo_dquoted(heredoc);
3180 len = strlen(heredoc);
3182 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3184 xmove_fd(pair.rd, redir->rd_fd);
3186 /* Try writing without forking. Newer kernels have
3187 * dynamically growing pipes. Must use non-blocking write! */
3190 written = write(pair.wr, heredoc, len);
3201 ndelay_off(pair.wr);
3203 /* Okay, pipe buffer was not big enough */
3204 /* Note: we must not create a stray child (bastard? :)
3205 * for the unsuspecting parent process. Child creates a grandchild
3206 * and exits before parent execs the process which consumes heredoc
3207 * (that exec happens after we return from this function) */
3214 disable_restore_tty_pgrp_on_exit();
3215 pid = BB_MMU ? xfork() : xvfork();
3219 close(redir->rd_fd); /* read side of the pipe */
3221 full_write(pair.wr, heredoc, len); /* may loop or block */
3224 /* Delegate blocking writes to another process */
3225 xmove_fd(pair.wr, STDOUT_FILENO);
3226 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3230 #if ENABLE_HUSH_FAST
3232 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3234 enable_restore_tty_pgrp_on_exit();
3240 wait(NULL); /* wait till child has died */
3243 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3244 * and stderr if they are redirected. */
3245 static int setup_redirects(struct command *prog, int squirrel[])
3248 struct redir_struct *redir;
3250 for (redir = prog->redirects; redir; redir = redir->next) {
3251 if (redir->rd_type == REDIRECT_HEREDOC2) {
3252 /* rd_fd<<HERE case */
3253 if (squirrel && redir->rd_fd < 3
3254 && squirrel[redir->rd_fd] < 0
3256 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3258 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3260 debug_printf_parse("set heredoc '%s'\n",
3261 redir->rd_filename);
3262 setup_heredoc(redir);
3266 if (redir->rd_dup == REDIRFD_TO_FILE) {
3267 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3269 if (redir->rd_filename == NULL) {
3270 /* Something went wrong in the parse.
3271 * Pretend it didn't happen */
3272 bb_error_msg("bug in redirect parse");
3275 mode = redir_table[redir->rd_type].mode;
3276 p = expand_string_to_string(redir->rd_filename);
3277 openfd = open_or_warn(p, mode);
3280 /* this could get lost if stderr has been redirected, but
3281 * bash and ash both lose it as well (though zsh doesn't!) */
3282 //what the above comment tries to say?
3286 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3287 openfd = redir->rd_dup;
3290 if (openfd != redir->rd_fd) {
3291 if (squirrel && redir->rd_fd < 3
3292 && squirrel[redir->rd_fd] < 0
3294 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3296 if (openfd == REDIRFD_CLOSE) {
3297 /* "n>-" means "close me" */
3298 close(redir->rd_fd);
3300 xdup2(openfd, redir->rd_fd);
3301 if (redir->rd_dup == REDIRFD_TO_FILE)
3309 static void restore_redirects(int squirrel[])
3312 for (i = 0; i < 3; i++) {
3315 /* We simply die on error */
3322 static void free_pipe_list(struct pipe *head);
3324 /* Return code is the exit status of the pipe */
3325 static void free_pipe(struct pipe *pi)
3328 struct command *command;
3329 struct redir_struct *r, *rnext;
3332 if (pi->stopped_cmds > 0) /* why? */
3334 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3335 for (i = 0; i < pi->num_cmds; i++) {
3336 command = &pi->cmds[i];
3337 debug_printf_clean(" command %d:\n", i);
3338 if (command->argv) {
3339 for (a = 0, p = command->argv; *p; a++, p++) {
3340 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3342 free_strings(command->argv);
3343 command->argv = NULL;
3345 /* not "else if": on syntax error, we may have both! */
3346 if (command->group) {
3347 debug_printf_clean(" begin group (cmd_type:%d)\n",
3349 free_pipe_list(command->group);
3350 debug_printf_clean(" end group\n");
3351 command->group = NULL;
3353 /* else is crucial here.
3354 * If group != NULL, child_func is meaningless */
3355 #if ENABLE_HUSH_FUNCTIONS
3356 else if (command->child_func) {
3357 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3358 command->child_func->parent_cmd = NULL;
3362 free(command->group_as_string);
3363 command->group_as_string = NULL;
3365 for (r = command->redirects; r; r = rnext) {
3366 debug_printf_clean(" redirect %d%s",
3367 r->rd_fd, redir_table[r->rd_type].descrip);
3368 /* guard against the case >$FOO, where foo is unset or blank */
3369 if (r->rd_filename) {
3370 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3371 free(r->rd_filename);
3372 r->rd_filename = NULL;
3374 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3378 command->redirects = NULL;
3380 free(pi->cmds); /* children are an array, they get freed all at once */
3388 static void free_pipe_list(struct pipe *head)
3390 struct pipe *pi, *next;
3392 for (pi = head; pi; pi = next) {
3394 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3397 debug_printf_clean("pipe followup code %d\n", pi->followup);
3399 /*pi->next = NULL;*/
3405 static int run_list(struct pipe *pi);
3407 #define parse_stream(pstring, input, end_trigger) \
3408 parse_stream(input, end_trigger)
3410 static struct pipe *parse_stream(char **pstring,
3411 struct in_str *input,
3413 static void parse_and_run_string(const char *s);
3416 static char *find_in_path(const char *arg)
3419 const char *PATH = get_local_var_value("PATH");
3425 const char *end = strchrnul(PATH, ':');
3426 int sz = end - PATH; /* must be int! */
3430 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3432 /* We have xxx::yyyy in $PATH,
3433 * it means "use current dir" */
3436 if (access(ret, F_OK) == 0)
3449 static const struct built_in_command* find_builtin_helper(const char *name,
3450 const struct built_in_command *x,
3451 const struct built_in_command *end)
3454 if (strcmp(name, x->b_cmd) != 0) {
3458 debug_printf_exec("found builtin '%s'\n", name);
3463 static const struct built_in_command* find_builtin1(const char *name)
3465 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3467 static const struct built_in_command* find_builtin(const char *name)
3469 const struct built_in_command *x = find_builtin1(name);
3472 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3475 #if ENABLE_HUSH_FUNCTIONS
3476 static struct function **find_function_slot(const char *name)
3478 struct function **funcpp = &G.top_func;
3480 if (strcmp(name, (*funcpp)->name) == 0) {
3483 funcpp = &(*funcpp)->next;
3488 static const struct function *find_function(const char *name)
3490 const struct function *funcp = *find_function_slot(name);
3492 debug_printf_exec("found function '%s'\n", name);
3496 /* Note: takes ownership on name ptr */
3497 static struct function *new_function(char *name)
3499 struct function **funcpp = find_function_slot(name);
3500 struct function *funcp = *funcpp;
3502 if (funcp != NULL) {
3503 struct command *cmd = funcp->parent_cmd;
3504 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3506 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3508 /* Note: if !funcp->body, do not free body_as_string!
3509 * This is a special case of "-F name body" function:
3510 * body_as_string was not malloced! */
3512 free_pipe_list(funcp->body);
3514 free(funcp->body_as_string);
3518 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3519 cmd->argv[0] = funcp->name;
3520 cmd->group = funcp->body;
3522 cmd->group_as_string = funcp->body_as_string;
3526 debug_printf_exec("remembering new function '%s'\n", name);
3527 funcp = *funcpp = xzalloc(sizeof(*funcp));
3528 /*funcp->next = NULL;*/
3535 static void unset_func(const char *name)
3537 struct function **funcpp = find_function_slot(name);
3538 struct function *funcp = *funcpp;
3540 if (funcp != NULL) {
3541 debug_printf_exec("freeing function '%s'\n", funcp->name);
3542 *funcpp = funcp->next;
3543 /* funcp is unlinked now, deleting it.
3544 * Note: if !funcp->body, the function was created by
3545 * "-F name body", do not free ->body_as_string
3546 * and ->name as they were not malloced. */
3548 free_pipe_list(funcp->body);
3551 free(funcp->body_as_string);
3559 #define exec_function(to_free, funcp, argv) \
3560 exec_function(funcp, argv)
3562 static void exec_function(char ***to_free,
3563 const struct function *funcp,
3564 char **argv) NORETURN;
3565 static void exec_function(char ***to_free,
3566 const struct function *funcp,
3572 argv[0] = G.global_argv[0];
3573 G.global_argv = argv;
3577 /* On MMU, funcp->body is always non-NULL */
3578 n = run_list(funcp->body);
3582 re_execute_shell(to_free,
3583 funcp->body_as_string,
3590 static int run_function(const struct function *funcp, char **argv)
3596 save_and_replace_G_args(&sv, argv);
3598 /* "we are in function, ok to use return" */
3599 sv_flg = G.flag_return_in_progress;
3600 G.flag_return_in_progress = -1;
3601 # if ENABLE_HUSH_LOCAL
3602 G.func_nest_level++;
3605 /* On MMU, funcp->body is always non-NULL */
3608 /* Function defined by -F */
3609 parse_and_run_string(funcp->body_as_string);
3610 rc = G.last_exitcode;
3614 rc = run_list(funcp->body);
3617 # if ENABLE_HUSH_LOCAL
3619 struct variable *var;
3620 struct variable **var_pp;
3622 var_pp = &G.top_var;
3623 while ((var = *var_pp) != NULL) {
3624 if (var->func_nest_level < G.func_nest_level) {
3625 var_pp = &var->next;
3629 if (var->flg_export)
3630 bb_unsetenv(var->varstr);
3631 /* Remove from global list */
3632 *var_pp = var->next;
3638 G.func_nest_level--;
3641 G.flag_return_in_progress = sv_flg;
3643 restore_G_args(&sv, argv);
3647 #endif /* ENABLE_HUSH_FUNCTIONS */
3651 #define exec_builtin(to_free, x, argv) \
3652 exec_builtin(x, argv)
3654 #define exec_builtin(to_free, x, argv) \
3655 exec_builtin(to_free, argv)
3657 static void exec_builtin(char ***to_free,
3658 const struct built_in_command *x,
3659 char **argv) NORETURN;
3660 static void exec_builtin(char ***to_free,
3661 const struct built_in_command *x,
3665 int rcode = x->b_function(argv);
3669 /* On NOMMU, we must never block!
3670 * Example: { sleep 99 | read line; } & echo Ok
3672 re_execute_shell(to_free,
3681 static void execvp_or_die(char **argv) NORETURN;
3682 static void execvp_or_die(char **argv)
3684 debug_printf_exec("execing '%s'\n", argv[0]);
3685 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3686 execvp(argv[0], argv);
3687 bb_perror_msg("can't execute '%s'", argv[0]);
3688 _exit(127); /* bash compat */
3692 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3693 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3694 #define pseudo_exec(nommu_save, command, argv_expanded) \
3695 pseudo_exec(command, argv_expanded)
3698 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3700 * Don't exit() here. If you don't exec, use _exit instead.
3701 * The at_exit handlers apparently confuse the calling process,
3702 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3703 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3704 char **argv, int assignment_cnt,
3705 char **argv_expanded) NORETURN;
3706 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3707 char **argv, int assignment_cnt,
3708 char **argv_expanded)
3712 /* Case when we are here: ... | var=val | ... */
3713 if (!argv[assignment_cnt])
3714 _exit(EXIT_SUCCESS);
3716 new_env = expand_assignments(argv, assignment_cnt);
3718 set_vars_and_save_old(new_env);
3719 free(new_env); /* optional */
3720 /* we can also destroy set_vars_and_save_old's return value,
3723 nommu_save->new_env = new_env;
3724 nommu_save->old_vars = set_vars_and_save_old(new_env);
3726 if (argv_expanded) {
3727 argv = argv_expanded;
3729 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3731 nommu_save->argv = argv;
3735 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3736 if (strchr(argv[0], '/') != NULL)
3740 /* Check if the command matches any of the builtins.
3741 * Depending on context, this might be redundant. But it's
3742 * easier to waste a few CPU cycles than it is to figure out
3743 * if this is one of those cases.
3746 /* On NOMMU, it is more expensive to re-execute shell
3747 * just in order to run echo or test builtin.
3748 * It's better to skip it here and run corresponding
3749 * non-builtin later. */
3750 const struct built_in_command *x;
3751 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3753 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3756 #if ENABLE_HUSH_FUNCTIONS
3757 /* Check if the command matches any functions */
3759 const struct function *funcp = find_function(argv[0]);
3761 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3766 #if ENABLE_FEATURE_SH_STANDALONE
3767 /* Check if the command matches any busybox applets */
3769 int a = find_applet_by_name(argv[0]);
3771 # if BB_MMU /* see above why on NOMMU it is not allowed */
3772 if (APPLET_IS_NOEXEC(a)) {
3773 debug_printf_exec("running applet '%s'\n", argv[0]);
3774 run_applet_no_and_exit(a, argv);
3777 /* Re-exec ourselves */
3778 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3779 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3780 execv(bb_busybox_exec_path, argv);
3781 /* If they called chroot or otherwise made the binary no longer
3782 * executable, fall through */
3787 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3790 execvp_or_die(argv);
3793 /* Called after [v]fork() in run_pipe
3795 static void pseudo_exec(nommu_save_t *nommu_save,
3796 struct command *command,
3797 char **argv_expanded) NORETURN;
3798 static void pseudo_exec(nommu_save_t *nommu_save,
3799 struct command *command,
3800 char **argv_expanded)
3802 if (command->argv) {
3803 pseudo_exec_argv(nommu_save, command->argv,
3804 command->assignment_cnt, argv_expanded);
3807 if (command->group) {
3808 /* Cases when we are here:
3811 * ... | ( list ) | ...
3812 * ... | { list } | ...
3816 debug_printf_exec("pseudo_exec: run_list\n");
3817 reset_traps_to_defaults();
3818 rcode = run_list(command->group);
3819 /* OK to leak memory by not calling free_pipe_list,
3820 * since this process is about to exit */
3823 re_execute_shell(&nommu_save->argv_from_re_execing,
3824 command->group_as_string,
3831 /* Case when we are here: ... | >file */
3832 debug_printf_exec("pseudo_exec'ed null command\n");
3833 _exit(EXIT_SUCCESS);
3837 static const char *get_cmdtext(struct pipe *pi)
3843 /* This is subtle. ->cmdtext is created only on first backgrounding.
3844 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3845 * On subsequent bg argv is trashed, but we won't use it */
3848 argv = pi->cmds[0].argv;
3849 if (!argv || !argv[0]) {
3850 pi->cmdtext = xzalloc(1);
3856 len += strlen(*argv) + 1;
3860 argv = pi->cmds[0].argv;
3862 len = strlen(*argv);
3863 memcpy(p, *argv, len);
3871 static void insert_bg_job(struct pipe *pi)
3873 struct pipe *job, **jobp;
3876 /* Linear search for the ID of the job to use */
3878 for (job = G.job_list; job; job = job->next)
3879 if (job->jobid >= pi->jobid)
3880 pi->jobid = job->jobid + 1;
3882 /* Add job to the list of running jobs */
3884 while ((job = *jobp) != NULL)
3886 job = *jobp = xmalloc(sizeof(*job));
3888 *job = *pi; /* physical copy */
3890 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3891 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3892 for (i = 0; i < pi->num_cmds; i++) {
3893 job->cmds[i].pid = pi->cmds[i].pid;
3894 /* all other fields are not used and stay zero */
3896 job->cmdtext = xstrdup(get_cmdtext(pi));
3898 if (G_interactive_fd)
3899 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3900 /* Last command's pid goes to $! */
3901 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3902 G.last_jobid = job->jobid;
3905 static void remove_bg_job(struct pipe *pi)
3907 struct pipe *prev_pipe;
3909 if (pi == G.job_list) {
3910 G.job_list = pi->next;
3912 prev_pipe = G.job_list;
3913 while (prev_pipe->next != pi)
3914 prev_pipe = prev_pipe->next;
3915 prev_pipe->next = pi->next;
3918 G.last_jobid = G.job_list->jobid;
3923 /* Remove a backgrounded job */
3924 static void delete_finished_bg_job(struct pipe *pi)
3927 pi->stopped_cmds = 0;
3933 /* Check to see if any processes have exited -- if they
3934 * have, figure out why and see if a job has completed */
3935 static int checkjobs(struct pipe* fg_pipe)
3945 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3947 attributes = WUNTRACED;
3948 if (fg_pipe == NULL)
3949 attributes |= WNOHANG;
3952 #if ENABLE_HUSH_FAST
3953 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3954 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3955 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3956 /* There was neither fork nor SIGCHLD since last waitpid */
3957 /* Avoid doing waitpid syscall if possible */
3958 if (!G.we_have_children) {
3962 if (fg_pipe == NULL) { /* is WNOHANG set? */
3963 /* We have children, but they did not exit
3964 * or stop yet (we saw no SIGCHLD) */
3967 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3971 /* Do we do this right?
3972 * bash-3.00# sleep 20 | false
3974 * [3]+ Stopped sleep 20 | false
3975 * bash-3.00# echo $?
3976 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3977 * [hush 1.14.0: yes we do it right]
3984 #if ENABLE_HUSH_FAST
3985 i = G.count_SIGCHLD;
3987 childpid = waitpid(-1, &status, attributes);
3988 if (childpid <= 0) {
3989 if (childpid && errno != ECHILD)
3990 bb_perror_msg("waitpid");
3991 #if ENABLE_HUSH_FAST
3992 else { /* Until next SIGCHLD, waitpid's are useless */
3993 G.we_have_children = (childpid == 0);
3994 G.handled_SIGCHLD = i;
3995 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4000 dead = WIFEXITED(status) || WIFSIGNALED(status);
4003 if (WIFSTOPPED(status))
4004 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
4005 childpid, WSTOPSIG(status), WEXITSTATUS(status));
4006 if (WIFSIGNALED(status))
4007 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
4008 childpid, WTERMSIG(status), WEXITSTATUS(status));
4009 if (WIFEXITED(status))
4010 debug_printf_jobs("pid %d exited, exitcode %d\n",
4011 childpid, WEXITSTATUS(status));
4013 /* Were we asked to wait for fg pipe? */
4015 for (i = 0; i < fg_pipe->num_cmds; i++) {
4016 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
4017 if (fg_pipe->cmds[i].pid != childpid)
4020 fg_pipe->cmds[i].pid = 0;
4021 fg_pipe->alive_cmds--;
4022 if (i == fg_pipe->num_cmds - 1) {
4023 /* last process gives overall exitstatus */
4024 rcode = WEXITSTATUS(status);
4025 /* bash prints killer signal's name for *last*
4026 * process in pipe (prints just newline for SIGINT).
4027 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
4029 if (WIFSIGNALED(status)) {
4030 int sig = WTERMSIG(status);
4031 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
4032 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
4033 * Maybe we need to use sig | 128? */
4036 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
4039 fg_pipe->cmds[i].is_stopped = 1;
4040 fg_pipe->stopped_cmds++;
4042 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
4043 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
4044 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
4045 /* All processes in fg pipe have exited or stopped */
4046 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4047 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4048 * and "killall -STOP cat" */
4049 if (G_interactive_fd) {
4051 if (fg_pipe->alive_cmds)
4052 insert_bg_job(fg_pipe);
4056 if (!fg_pipe->alive_cmds)
4059 /* There are still running processes in the fg pipe */
4060 goto wait_more; /* do waitpid again */
4062 /* it wasnt fg_pipe, look for process in bg pipes */
4066 /* We asked to wait for bg or orphaned children */
4067 /* No need to remember exitcode in this case */
4068 for (pi = G.job_list; pi; pi = pi->next) {
4069 for (i = 0; i < pi->num_cmds; i++) {
4070 if (pi->cmds[i].pid == childpid)
4071 goto found_pi_and_prognum;
4074 /* Happens when shell is used as init process (init=/bin/sh) */
4075 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4076 continue; /* do waitpid again */
4078 found_pi_and_prognum:
4081 pi->cmds[i].pid = 0;
4083 if (!pi->alive_cmds) {
4084 if (G_interactive_fd)
4085 printf(JOB_STATUS_FORMAT, pi->jobid,
4086 "Done", pi->cmdtext);
4087 delete_finished_bg_job(pi);
4091 pi->cmds[i].is_stopped = 1;
4095 } /* while (waitpid succeeds)... */
4101 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4104 int rcode = checkjobs(fg_pipe);
4105 if (G_saved_tty_pgrp) {
4106 /* Job finished, move the shell to the foreground */
4107 p = getpgrp(); /* our process group id */
4108 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4109 tcsetpgrp(G_interactive_fd, p);
4115 /* Start all the jobs, but don't wait for anything to finish.
4118 * Return code is normally -1, when the caller has to wait for children
4119 * to finish to determine the exit status of the pipe. If the pipe
4120 * is a simple builtin command, however, the action is done by the
4121 * time run_pipe returns, and the exit code is provided as the
4124 * Returns -1 only if started some children. IOW: we have to
4125 * mask out retvals of builtins etc with 0xff!
4127 * The only case when we do not need to [v]fork is when the pipe
4128 * is single, non-backgrounded, non-subshell command. Examples:
4129 * cmd ; ... { list } ; ...
4130 * cmd && ... { list } && ...
4131 * cmd || ... { list } || ...
4132 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4133 * or (if SH_STANDALONE) an applet, and we can run the { list }
4134 * with run_list. If it isn't one of these, we fork and exec cmd.
4136 * Cases when we must fork:
4137 * non-single: cmd | cmd
4138 * backgrounded: cmd & { list } &
4139 * subshell: ( list ) [&]
4141 static NOINLINE int run_pipe(struct pipe *pi)
4143 static const char *const null_ptr = NULL;
4146 struct command *command;
4147 char **argv_expanded;
4150 /* it is not always needed, but we aim to smaller code */
4151 int squirrel[] = { -1, -1, -1 };
4154 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4157 IF_HUSH_JOB(pi->pgrp = -1;)
4158 pi->stopped_cmds = 0;
4159 command = &(pi->cmds[0]);
4160 argv_expanded = NULL;
4162 if (pi->num_cmds != 1
4163 || pi->followup == PIPE_BG
4164 || command->cmd_type == CMD_SUBSHELL
4171 debug_printf_exec(": group:%p argv:'%s'\n",
4172 command->group, command->argv ? command->argv[0] : "NONE");
4174 if (command->group) {
4175 #if ENABLE_HUSH_FUNCTIONS
4176 if (command->cmd_type == CMD_FUNCDEF) {
4177 /* "executing" func () { list } */
4178 struct function *funcp;
4180 funcp = new_function(command->argv[0]);
4181 /* funcp->name is already set to argv[0] */
4182 funcp->body = command->group;
4184 funcp->body_as_string = command->group_as_string;
4185 command->group_as_string = NULL;
4187 command->group = NULL;
4188 command->argv[0] = NULL;
4189 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4190 funcp->parent_cmd = command;
4191 command->child_func = funcp;
4193 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4195 return EXIT_SUCCESS;
4199 debug_printf("non-subshell group\n");
4200 rcode = 1; /* exitcode if redir failed */
4201 if (setup_redirects(command, squirrel) == 0) {
4202 debug_printf_exec(": run_list\n");
4203 rcode = run_list(command->group) & 0xff;
4205 restore_redirects(squirrel);
4206 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4208 debug_printf_exec("run_pipe: return %d\n", rcode);
4212 argv = command->argv ? command->argv : (char **) &null_ptr;
4214 const struct built_in_command *x;
4215 #if ENABLE_HUSH_FUNCTIONS
4216 const struct function *funcp;
4220 char **new_env = NULL;
4221 struct variable *old_vars = NULL;
4223 if (argv[command->assignment_cnt] == NULL) {
4224 /* Assignments, but no command */
4225 /* Ensure redirects take effect (that is, create files).
4226 * Try "a=t >file": */
4227 rcode = setup_redirects(command, squirrel);
4228 restore_redirects(squirrel);
4229 /* Set shell variables */
4231 p = expand_string_to_string(*argv);
4232 debug_printf_exec("set shell var:'%s'->'%s'\n",
4234 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4237 /* Redirect error sets $? to 1. Othervise,
4238 * if evaluating assignment value set $?, retain it.
4239 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4241 rcode = G.last_exitcode;
4242 /* Do we need to flag set_local_var() errors?
4243 * "assignment to readonly var" and "putenv error"
4245 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4247 debug_printf_exec("run_pipe: return %d\n", rcode);
4251 /* Expand the rest into (possibly) many strings each */
4253 #if ENABLE_HUSH_BASH_COMPAT
4254 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4255 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4258 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4259 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4260 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4265 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4268 /* if someone gives us an empty string: `cmd with empty output` */
4269 if (!argv_expanded[0]) {
4270 free(argv_expanded);
4272 return G.last_exitcode;
4275 x = find_builtin(argv_expanded[0]);
4276 #if ENABLE_HUSH_FUNCTIONS
4279 funcp = find_function(argv_expanded[0]);
4283 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4284 debug_printf("exec with redirects only\n");
4285 rcode = setup_redirects(command, NULL);
4286 goto clean_up_and_ret1;
4289 /* setup_redirects acts on file descriptors, not FILEs.
4290 * This is perfect for work that comes after exec().
4291 * Is it really safe for inline use? Experimentally,
4292 * things seem to work. */
4293 rcode = setup_redirects(command, squirrel);
4295 new_env = expand_assignments(argv, command->assignment_cnt);
4296 old_vars = set_vars_and_save_old(new_env);
4298 debug_printf_exec(": builtin '%s' '%s'...\n",
4299 x->b_cmd, argv_expanded[1]);
4300 rcode = x->b_function(argv_expanded) & 0xff;
4303 #if ENABLE_HUSH_FUNCTIONS
4305 # if ENABLE_HUSH_LOCAL
4306 struct variable **sv;
4307 sv = G.shadowed_vars_pp;
4308 G.shadowed_vars_pp = &old_vars;
4310 debug_printf_exec(": function '%s' '%s'...\n",
4311 funcp->name, argv_expanded[1]);
4312 rcode = run_function(funcp, argv_expanded) & 0xff;
4313 # if ENABLE_HUSH_LOCAL
4314 G.shadowed_vars_pp = sv;
4319 #if ENABLE_FEATURE_SH_STANDALONE
4322 restore_redirects(squirrel);
4323 unset_vars(new_env);
4326 free(argv_expanded);
4327 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4329 debug_printf_exec("run_pipe return %d\n", rcode);
4333 #if ENABLE_FEATURE_SH_STANDALONE
4334 i = find_applet_by_name(argv_expanded[0]);
4335 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4336 rcode = setup_redirects(command, squirrel);
4338 new_env = expand_assignments(argv, command->assignment_cnt);
4339 old_vars = set_vars_and_save_old(new_env);
4340 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4341 argv_expanded[0], argv_expanded[1]);
4342 rcode = run_nofork_applet(i, argv_expanded);
4344 goto clean_up_and_ret;
4347 /* It is neither builtin nor applet. We must fork. */
4351 /* NB: argv_expanded may already be created, and that
4352 * might include `cmd` runs! Do not rerun it! We *must*
4353 * use argv_expanded if it's non-NULL */
4355 /* Going to fork a child per each pipe member */
4359 for (i = 0; i < pi->num_cmds; i++) {
4360 struct fd_pair pipefds;
4362 volatile nommu_save_t nommu_save;
4363 nommu_save.new_env = NULL;
4364 nommu_save.old_vars = NULL;
4365 nommu_save.argv = NULL;
4366 nommu_save.argv_from_re_execing = NULL;
4368 command = &(pi->cmds[i]);
4369 if (command->argv) {
4370 debug_printf_exec(": pipe member '%s' '%s'...\n",
4371 command->argv[0], command->argv[1]);
4373 debug_printf_exec(": pipe member with no argv\n");
4376 /* pipes are inserted between pairs of commands */
4379 if ((i + 1) < pi->num_cmds)
4380 xpiped_pair(pipefds);
4382 command->pid = BB_MMU ? fork() : vfork();
4383 if (!command->pid) { /* child */
4385 disable_restore_tty_pgrp_on_exit();
4386 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4388 /* Every child adds itself to new process group
4389 * with pgid == pid_of_first_child_in_pipe */
4390 if (G.run_list_level == 1 && G_interactive_fd) {
4393 if (pgrp < 0) /* true for 1st process only */
4395 if (setpgid(0, pgrp) == 0
4396 && pi->followup != PIPE_BG
4397 && G_saved_tty_pgrp /* we have ctty */
4399 /* We do it in *every* child, not just first,
4401 tcsetpgrp(G_interactive_fd, pgrp);
4405 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4406 /* 1st cmd in backgrounded pipe
4407 * should have its stdin /dev/null'ed */
4409 if (open(bb_dev_null, O_RDONLY))
4410 xopen("/", O_RDONLY);
4412 xmove_fd(nextin, 0);
4414 xmove_fd(pipefds.wr, 1);
4417 /* Like bash, explicit redirects override pipes,
4418 * and the pipe fd is available for dup'ing. */
4419 if (setup_redirects(command, NULL))
4422 /* Restore default handlers just prior to exec */
4423 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4425 /* Stores to nommu_save list of env vars putenv'ed
4426 * (NOMMU, on MMU we don't need that) */
4427 /* cast away volatility... */
4428 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4429 /* pseudo_exec() does not return */
4432 /* parent or error */
4433 #if ENABLE_HUSH_FAST
4435 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4437 enable_restore_tty_pgrp_on_exit();
4439 /* Clean up after vforked child */
4440 free(nommu_save.argv);
4441 free(nommu_save.argv_from_re_execing);
4442 unset_vars(nommu_save.new_env);
4443 add_vars(nommu_save.old_vars);
4445 free(argv_expanded);
4446 argv_expanded = NULL;
4447 if (command->pid < 0) { /* [v]fork failed */
4448 /* Clearly indicate, was it fork or vfork */
4449 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
4453 /* Second and next children need to know pid of first one */
4455 pi->pgrp = command->pid;
4461 if ((i + 1) < pi->num_cmds)
4463 /* Pass read (output) pipe end to next iteration */
4464 nextin = pipefds.rd;
4467 if (!pi->alive_cmds) {
4469 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4474 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4478 #ifndef debug_print_tree
4479 static void debug_print_tree(struct pipe *pi, int lvl)
4481 static const char *const PIPE[] = {
4487 static const char *RES[] = {
4488 [RES_NONE ] = "NONE" ,
4491 [RES_THEN ] = "THEN" ,
4492 [RES_ELIF ] = "ELIF" ,
4493 [RES_ELSE ] = "ELSE" ,
4496 # if ENABLE_HUSH_LOOPS
4497 [RES_FOR ] = "FOR" ,
4498 [RES_WHILE] = "WHILE",
4499 [RES_UNTIL] = "UNTIL",
4501 [RES_DONE ] = "DONE" ,
4503 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4506 # if ENABLE_HUSH_CASE
4507 [RES_CASE ] = "CASE" ,
4508 [RES_CASE_IN ] = "CASE_IN" ,
4509 [RES_MATCH] = "MATCH",
4510 [RES_CASE_BODY] = "CASE_BODY",
4511 [RES_ESAC ] = "ESAC" ,
4513 [RES_XXXX ] = "XXXX" ,
4514 [RES_SNTX ] = "SNTX" ,
4516 static const char *const CMDTYPE[] = {
4520 # if ENABLE_HUSH_FUNCTIONS
4529 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4530 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4532 while (prn < pi->num_cmds) {
4533 struct command *command = &pi->cmds[prn];
4534 char **argv = command->argv;
4536 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4538 command->assignment_cnt);
4539 if (command->group) {
4540 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4541 CMDTYPE[command->cmd_type],
4544 , " group_as_string:", command->group_as_string
4549 debug_print_tree(command->group, lvl+1);
4553 if (argv) while (*argv) {
4554 fprintf(stderr, " '%s'", *argv);
4557 fprintf(stderr, "\n");
4564 #endif /* debug_print_tree */
4566 /* NB: called by pseudo_exec, and therefore must not modify any
4567 * global data until exec/_exit (we can be a child after vfork!) */
4568 static int run_list(struct pipe *pi)
4570 #if ENABLE_HUSH_CASE
4571 char *case_word = NULL;
4573 #if ENABLE_HUSH_LOOPS
4574 struct pipe *loop_top = NULL;
4575 char **for_lcur = NULL;
4576 char **for_list = NULL;
4578 smallint last_followup;
4580 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4581 smalluint cond_code = 0;
4583 enum { cond_code = 0 };
4586 smallint rword; /* enum reserved_style */
4587 smallint last_rword; /* ditto */
4590 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4593 #if ENABLE_HUSH_LOOPS
4594 /* Check syntax for "for" */
4595 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4596 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4598 /* current word is FOR or IN (BOLD in comments below) */
4599 if (cpipe->next == NULL) {
4600 syntax_error("malformed for");
4602 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4605 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4606 if (cpipe->next->res_word == RES_DO)
4608 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4609 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4610 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4612 syntax_error("malformed for");
4614 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4620 /* Past this point, all code paths should jump to ret: label
4621 * in order to return, no direct "return" statements please.
4622 * This helps to ensure that no memory is leaked. */
4630 last_rword = RES_XXXX;
4632 last_followup = PIPE_SEQ;
4633 rcode = G.last_exitcode;
4635 /* Go through list of pipes, (maybe) executing them. */
4636 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4640 IF_HAS_KEYWORDS(rword = pi->res_word;)
4641 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4642 rword, cond_code, last_rword);
4643 #if ENABLE_HUSH_LOOPS
4644 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4645 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4647 /* start of a loop: remember where loop starts */
4652 /* Still in the same "if...", "then..." or "do..." branch? */
4653 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4654 if ((rcode == 0 && last_followup == PIPE_OR)
4655 || (rcode != 0 && last_followup == PIPE_AND)
4657 /* It is "<true> || CMD" or "<false> && CMD"
4658 * and we should not execute CMD */
4659 debug_printf_exec("skipped cmd because of || or &&\n");
4660 last_followup = pi->followup;
4664 last_followup = pi->followup;
4665 IF_HAS_KEYWORDS(last_rword = rword;)
4668 if (rword == RES_THEN) {
4669 /* if false; then ... fi has exitcode 0! */
4670 G.last_exitcode = rcode = EXIT_SUCCESS;
4671 /* "if <false> THEN cmd": skip cmd */
4675 if (rword == RES_ELSE || rword == RES_ELIF) {
4676 /* "if <true> then ... ELSE/ELIF cmd":
4677 * skip cmd and all following ones */
4682 #if ENABLE_HUSH_LOOPS
4683 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4685 /* first loop through for */
4687 static const char encoded_dollar_at[] ALIGN1 = {
4688 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4689 }; /* encoded representation of "$@" */
4690 static const char *const encoded_dollar_at_argv[] = {
4691 encoded_dollar_at, NULL
4692 }; /* argv list with one element: "$@" */
4695 vals = (char**)encoded_dollar_at_argv;
4696 if (pi->next->res_word == RES_IN) {
4697 /* if no variable values after "in" we skip "for" */
4698 if (!pi->next->cmds[0].argv) {
4699 G.last_exitcode = rcode = EXIT_SUCCESS;
4700 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4703 vals = pi->next->cmds[0].argv;
4704 } /* else: "for var; do..." -> assume "$@" list */
4705 /* create list of variable values */
4706 debug_print_strings("for_list made from", vals);
4707 for_list = expand_strvec_to_strvec(vals);
4708 for_lcur = for_list;
4709 debug_print_strings("for_list", for_list);
4712 /* "for" loop is over, clean up */
4718 /* Insert next value from for_lcur */
4719 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4720 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4723 if (rword == RES_IN) {
4724 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4726 if (rword == RES_DONE) {
4727 continue; /* "done" has no cmds too */
4730 #if ENABLE_HUSH_CASE
4731 if (rword == RES_CASE) {
4732 case_word = expand_strvec_to_string(pi->cmds->argv);
4735 if (rword == RES_MATCH) {
4738 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4740 /* all prev words didn't match, does this one match? */
4741 argv = pi->cmds->argv;
4743 char *pattern = expand_string_to_string(*argv);
4744 /* TODO: which FNM_xxx flags to use? */
4745 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4747 if (cond_code == 0) { /* match! we will execute this branch */
4748 free(case_word); /* make future "word)" stop */
4756 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4758 continue; /* not matched yet, skip this pipe */
4761 /* Just pressing <enter> in shell should check for jobs.
4762 * OTOH, in non-interactive shell this is useless
4763 * and only leads to extra job checks */
4764 if (pi->num_cmds == 0) {
4765 if (G_interactive_fd)
4766 goto check_jobs_and_continue;
4770 /* After analyzing all keywords and conditions, we decided
4771 * to execute this pipe. NB: have to do checkjobs(NULL)
4772 * after run_pipe to collect any background children,
4773 * even if list execution is to be stopped. */
4774 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4777 #if ENABLE_HUSH_LOOPS
4778 G.flag_break_continue = 0;
4780 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4782 /* We ran a builtin, function, or group.
4783 * rcode is already known
4784 * and we don't need to wait for anything. */
4785 G.last_exitcode = rcode;
4786 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4787 check_and_run_traps(0);
4788 #if ENABLE_HUSH_LOOPS
4789 /* Was it "break" or "continue"? */
4790 if (G.flag_break_continue) {
4791 smallint fbc = G.flag_break_continue;
4792 /* We might fall into outer *loop*,
4793 * don't want to break it too */
4795 G.depth_break_continue--;
4796 if (G.depth_break_continue == 0)
4797 G.flag_break_continue = 0;
4798 /* else: e.g. "continue 2" should *break* once, *then* continue */
4799 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4800 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4801 goto check_jobs_and_break;
4802 /* "continue": simulate end of loop */
4807 #if ENABLE_HUSH_FUNCTIONS
4808 if (G.flag_return_in_progress == 1) {
4809 /* same as "goto check_jobs_and_break" */
4814 } else if (pi->followup == PIPE_BG) {
4815 /* What does bash do with attempts to background builtins? */
4816 /* even bash 3.2 doesn't do that well with nested bg:
4817 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4818 * I'm NOT treating inner &'s as jobs */
4819 check_and_run_traps(0);
4821 if (G.run_list_level == 1)
4824 G.last_exitcode = rcode = EXIT_SUCCESS;
4825 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4828 if (G.run_list_level == 1 && G_interactive_fd) {
4829 /* Waits for completion, then fg's main shell */
4830 rcode = checkjobs_and_fg_shell(pi);
4831 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4832 check_and_run_traps(0);
4835 { /* This one just waits for completion */
4836 rcode = checkjobs(pi);
4837 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4838 check_and_run_traps(0);
4840 G.last_exitcode = rcode;
4844 /* Analyze how result affects subsequent commands */
4846 if (rword == RES_IF || rword == RES_ELIF)
4849 #if ENABLE_HUSH_LOOPS
4850 /* Beware of "while false; true; do ..."! */
4851 if (pi->next && pi->next->res_word == RES_DO) {
4852 if (rword == RES_WHILE) {
4854 /* "while false; do...done" - exitcode 0 */
4855 G.last_exitcode = rcode = EXIT_SUCCESS;
4856 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4857 goto check_jobs_and_break;
4860 if (rword == RES_UNTIL) {
4862 debug_printf_exec(": until expr is true: breaking\n");
4863 check_jobs_and_break:
4871 check_jobs_and_continue:
4878 #if ENABLE_HUSH_LOOPS
4883 #if ENABLE_HUSH_CASE
4887 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4891 /* Select which version we will use */
4892 static int run_and_free_list(struct pipe *pi)
4895 debug_printf_exec("run_and_free_list entered\n");
4897 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4898 rcode = run_list(pi);
4900 /* free_pipe_list has the side effect of clearing memory.
4901 * In the long run that function can be merged with run_list,
4902 * but doing that now would hobble the debugging effort. */
4904 debug_printf_exec("run_and_free_list return %d\n", rcode);
4909 static struct pipe *new_pipe(void)
4912 pi = xzalloc(sizeof(struct pipe));
4913 /*pi->followup = 0; - deliberately invalid value */
4914 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4918 /* Command (member of a pipe) is complete, or we start a new pipe
4919 * if ctx->command is NULL.
4920 * No errors possible here.
4922 static int done_command(struct parse_context *ctx)
4924 /* The command is really already in the pipe structure, so
4925 * advance the pipe counter and make a new, null command. */
4926 struct pipe *pi = ctx->pipe;
4927 struct command *command = ctx->command;
4930 if (IS_NULL_CMD(command)) {
4931 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4935 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4936 //debug_print_tree(ctx->list_head, 20);
4938 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4941 /* Only real trickiness here is that the uncommitted
4942 * command structure is not counted in pi->num_cmds. */
4943 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4944 ctx->command = command = &pi->cmds[pi->num_cmds];
4946 memset(command, 0, sizeof(*command));
4947 return pi->num_cmds; /* used only for 0/nonzero check */
4950 static void done_pipe(struct parse_context *ctx, pipe_style type)
4954 debug_printf_parse("done_pipe entered, followup %d\n", type);
4955 /* Close previous command */
4956 not_null = done_command(ctx);
4957 ctx->pipe->followup = type;
4959 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4960 ctx->ctx_inverted = 0;
4961 ctx->pipe->res_word = ctx->ctx_res_w;
4964 /* Without this check, even just <enter> on command line generates
4965 * tree of three NOPs (!). Which is harmless but annoying.
4966 * IOW: it is safe to do it unconditionally. */
4969 || ctx->ctx_res_w == RES_FI
4971 #if ENABLE_HUSH_LOOPS
4972 || ctx->ctx_res_w == RES_DONE
4973 || ctx->ctx_res_w == RES_FOR
4974 || ctx->ctx_res_w == RES_IN
4976 #if ENABLE_HUSH_CASE
4977 || ctx->ctx_res_w == RES_ESAC
4981 debug_printf_parse("done_pipe: adding new pipe: "
4982 "not_null:%d ctx->ctx_res_w:%d\n",
4983 not_null, ctx->ctx_res_w);
4985 ctx->pipe->next = new_p;
4987 /* RES_THEN, RES_DO etc are "sticky" -
4988 * they remain set for pipes inside if/while.
4989 * This is used to control execution.
4990 * RES_FOR and RES_IN are NOT sticky (needed to support
4991 * cases where variable or value happens to match a keyword):
4993 #if ENABLE_HUSH_LOOPS
4994 if (ctx->ctx_res_w == RES_FOR
4995 || ctx->ctx_res_w == RES_IN)
4996 ctx->ctx_res_w = RES_NONE;
4998 #if ENABLE_HUSH_CASE
4999 if (ctx->ctx_res_w == RES_MATCH)
5000 ctx->ctx_res_w = RES_CASE_BODY;
5001 if (ctx->ctx_res_w == RES_CASE)
5002 ctx->ctx_res_w = RES_CASE_IN;
5004 ctx->command = NULL; /* trick done_command below */
5005 /* Create the memory for command, roughly:
5006 * ctx->pipe->cmds = new struct command;
5007 * ctx->command = &ctx->pipe->cmds[0];
5010 //debug_print_tree(ctx->list_head, 10);
5012 debug_printf_parse("done_pipe return\n");
5015 static void initialize_context(struct parse_context *ctx)
5017 memset(ctx, 0, sizeof(*ctx));
5018 ctx->pipe = ctx->list_head = new_pipe();
5019 /* Create the memory for command, roughly:
5020 * ctx->pipe->cmds = new struct command;
5021 * ctx->command = &ctx->pipe->cmds[0];
5026 /* If a reserved word is found and processed, parse context is modified
5027 * and 1 is returned.
5030 struct reserved_combo {
5033 unsigned char assignment_flag;
5037 FLAG_END = (1 << RES_NONE ),
5039 FLAG_IF = (1 << RES_IF ),
5040 FLAG_THEN = (1 << RES_THEN ),
5041 FLAG_ELIF = (1 << RES_ELIF ),
5042 FLAG_ELSE = (1 << RES_ELSE ),
5043 FLAG_FI = (1 << RES_FI ),
5045 # if ENABLE_HUSH_LOOPS
5046 FLAG_FOR = (1 << RES_FOR ),
5047 FLAG_WHILE = (1 << RES_WHILE),
5048 FLAG_UNTIL = (1 << RES_UNTIL),
5049 FLAG_DO = (1 << RES_DO ),
5050 FLAG_DONE = (1 << RES_DONE ),
5051 FLAG_IN = (1 << RES_IN ),
5053 # if ENABLE_HUSH_CASE
5054 FLAG_MATCH = (1 << RES_MATCH),
5055 FLAG_ESAC = (1 << RES_ESAC ),
5057 FLAG_START = (1 << RES_XXXX ),
5060 static const struct reserved_combo* match_reserved_word(o_string *word)
5062 /* Mostly a list of accepted follow-up reserved words.
5063 * FLAG_END means we are done with the sequence, and are ready
5064 * to turn the compound list into a command.
5065 * FLAG_START means the word must start a new compound list.
5067 static const struct reserved_combo reserved_list[] = {
5069 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5070 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5071 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5072 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5073 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5074 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5076 # if ENABLE_HUSH_LOOPS
5077 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5078 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5079 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5080 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5081 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5082 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5084 # if ENABLE_HUSH_CASE
5085 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5086 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5089 const struct reserved_combo *r;
5091 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5092 if (strcmp(word->data, r->literal) == 0)
5097 /* Return 0: not a keyword, 1: keyword
5099 static int reserved_word(o_string *word, struct parse_context *ctx)
5101 # if ENABLE_HUSH_CASE
5102 static const struct reserved_combo reserved_match = {
5103 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5106 const struct reserved_combo *r;
5110 r = match_reserved_word(word);
5114 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5115 # if ENABLE_HUSH_CASE
5116 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5117 /* "case word IN ..." - IN part starts first MATCH part */
5118 r = &reserved_match;
5121 if (r->flag == 0) { /* '!' */
5122 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5123 syntax_error("! ! command");
5124 ctx->ctx_res_w = RES_SNTX;
5126 ctx->ctx_inverted = 1;
5129 if (r->flag & FLAG_START) {
5130 struct parse_context *old;
5132 old = xmalloc(sizeof(*old));
5133 debug_printf_parse("push stack %p\n", old);
5134 *old = *ctx; /* physical copy */
5135 initialize_context(ctx);
5137 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5138 syntax_error_at(word->data);
5139 ctx->ctx_res_w = RES_SNTX;
5142 /* "{...} fi" is ok. "{...} if" is not
5144 * if { echo foo; } then { echo bar; } fi */
5145 if (ctx->command->group)
5146 done_pipe(ctx, PIPE_SEQ);
5149 ctx->ctx_res_w = r->res;
5150 ctx->old_flag = r->flag;
5151 word->o_assignment = r->assignment_flag;
5153 if (ctx->old_flag & FLAG_END) {
5154 struct parse_context *old;
5156 done_pipe(ctx, PIPE_SEQ);
5157 debug_printf_parse("pop stack %p\n", ctx->stack);
5159 old->command->group = ctx->list_head;
5160 old->command->cmd_type = CMD_NORMAL;
5162 o_addstr(&old->as_string, ctx->as_string.data);
5163 o_free_unsafe(&ctx->as_string);
5164 old->command->group_as_string = xstrdup(old->as_string.data);
5165 debug_printf_parse("pop, remembering as:'%s'\n",
5166 old->command->group_as_string);
5168 *ctx = *old; /* physical copy */
5173 #endif /* HAS_KEYWORDS */
5175 /* Word is complete, look at it and update parsing context.
5176 * Normal return is 0. Syntax errors return 1.
5177 * Note: on return, word is reset, but not o_free'd!
5179 static int done_word(o_string *word, struct parse_context *ctx)
5181 struct command *command = ctx->command;
5183 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5184 if (word->length == 0 && word->o_quoted == 0) {
5185 debug_printf_parse("done_word return 0: true null, ignored\n");
5189 if (ctx->pending_redirect) {
5190 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5191 * only if run as "bash", not "sh" */
5192 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5194 * ...the word that follows the redirection operator
5195 * shall be subjected to tilde expansion, parameter expansion,
5196 * command substitution, arithmetic expansion, and quote
5197 * removal. Pathname expansion shall not be performed
5198 * on the word by a non-interactive shell; an interactive
5199 * shell may perform it, but shall do so only when
5200 * the expansion would result in one word."
5202 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5203 /* Cater for >\file case:
5204 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5205 * Same with heredocs:
5206 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5208 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5209 unbackslash(ctx->pending_redirect->rd_filename);
5210 /* Is it <<"HEREDOC"? */
5211 if (word->o_quoted) {
5212 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5215 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5216 ctx->pending_redirect = NULL;
5218 /* If this word wasn't an assignment, next ones definitely
5219 * can't be assignments. Even if they look like ones. */
5220 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5221 && word->o_assignment != WORD_IS_KEYWORD
5223 word->o_assignment = NOT_ASSIGNMENT;
5225 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5226 command->assignment_cnt++;
5227 word->o_assignment = MAYBE_ASSIGNMENT;
5231 # if ENABLE_HUSH_CASE
5232 if (ctx->ctx_dsemicolon
5233 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5235 /* already done when ctx_dsemicolon was set to 1: */
5236 /* ctx->ctx_res_w = RES_MATCH; */
5237 ctx->ctx_dsemicolon = 0;
5240 if (!command->argv /* if it's the first word... */
5241 # if ENABLE_HUSH_LOOPS
5242 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5243 && ctx->ctx_res_w != RES_IN
5245 # if ENABLE_HUSH_CASE
5246 && ctx->ctx_res_w != RES_CASE
5249 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5250 if (reserved_word(word, ctx)) {
5251 o_reset_to_empty_unquoted(word);
5252 debug_printf_parse("done_word return %d\n",
5253 (ctx->ctx_res_w == RES_SNTX));
5254 return (ctx->ctx_res_w == RES_SNTX);
5256 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5257 if (strcmp(word->data, "export") == 0
5258 # if ENABLE_HUSH_LOCAL
5259 || strcmp(word->data, "local") == 0
5262 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5265 # if ENABLE_HUSH_BASH_COMPAT
5266 if (strcmp(word->data, "[[") == 0) {
5267 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5273 if (command->group) {
5274 /* "{ echo foo; } echo bar" - bad */
5275 syntax_error_at(word->data);
5276 debug_printf_parse("done_word return 1: syntax error, "
5277 "groups and arglists don't mix\n");
5280 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5281 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5282 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5283 /* (otherwise it's known to be not empty and is already safe) */
5285 /* exclude "$@" - it can expand to no word despite "" */
5286 char *p = word->data;
5287 while (p[0] == SPECIAL_VAR_SYMBOL
5288 && (p[1] & 0x7f) == '@'
5289 && p[2] == SPECIAL_VAR_SYMBOL
5293 if (p == word->data || p[0] != '\0') {
5294 /* saw no "$@", or not only "$@" but some
5295 * real text is there too */
5296 /* insert "empty variable" reference, this makes
5297 * e.g. "", $empty"" etc to not disappear */
5298 o_addchr(word, SPECIAL_VAR_SYMBOL);
5299 o_addchr(word, SPECIAL_VAR_SYMBOL);
5302 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5303 debug_print_strings("word appended to argv", command->argv);
5306 #if ENABLE_HUSH_LOOPS
5307 if (ctx->ctx_res_w == RES_FOR) {
5309 || !is_well_formed_var_name(command->argv[0], '\0')
5311 /* bash says just "not a valid identifier" */
5312 syntax_error("not a valid identifier in for");
5315 /* Force FOR to have just one word (variable name) */
5316 /* NB: basically, this makes hush see "for v in ..."
5317 * syntax as if it is "for v; in ...". FOR and IN become
5318 * two pipe structs in parse tree. */
5319 done_pipe(ctx, PIPE_SEQ);
5322 #if ENABLE_HUSH_CASE
5323 /* Force CASE to have just one word */
5324 if (ctx->ctx_res_w == RES_CASE) {
5325 done_pipe(ctx, PIPE_SEQ);
5329 o_reset_to_empty_unquoted(word);
5331 debug_printf_parse("done_word return 0\n");
5336 /* Peek ahead in the input to find out if we have a "&n" construct,
5337 * as in "2>&1", that represents duplicating a file descriptor.
5339 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5340 * REDIRFD_SYNTAX_ERR if syntax error,
5341 * REDIRFD_TO_FILE if no & was seen,
5342 * or the number found.
5345 #define parse_redir_right_fd(as_string, input) \
5346 parse_redir_right_fd(input)
5348 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5354 return REDIRFD_TO_FILE;
5356 ch = i_getch(input); /* get the & */
5357 nommu_addchr(as_string, ch);
5360 ch = i_getch(input);
5361 nommu_addchr(as_string, ch);
5362 return REDIRFD_CLOSE;
5366 while (ch != EOF && isdigit(ch)) {
5367 d = d*10 + (ch-'0');
5369 ch = i_getch(input);
5370 nommu_addchr(as_string, ch);
5375 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5377 bb_error_msg("ambiguous redirect");
5378 return REDIRFD_SYNTAX_ERR;
5381 /* Return code is 0 normal, 1 if a syntax error is detected
5383 static int parse_redirect(struct parse_context *ctx,
5386 struct in_str *input)
5388 struct command *command = ctx->command;
5389 struct redir_struct *redir;
5390 struct redir_struct **redirp;
5393 dup_num = REDIRFD_TO_FILE;
5394 if (style != REDIRECT_HEREDOC) {
5395 /* Check for a '>&1' type redirect */
5396 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5397 if (dup_num == REDIRFD_SYNTAX_ERR)
5400 int ch = i_peek(input);
5401 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5402 if (dup_num) { /* <<-... */
5403 ch = i_getch(input);
5404 nommu_addchr(&ctx->as_string, ch);
5409 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5410 int ch = i_peek(input);
5412 /* >|FILE redirect ("clobbering" >).
5413 * Since we do not support "set -o noclobber" yet,
5414 * >| and > are the same for now. Just eat |.
5416 ch = i_getch(input);
5417 nommu_addchr(&ctx->as_string, ch);
5421 /* Create a new redir_struct and append it to the linked list */
5422 redirp = &command->redirects;
5423 while ((redir = *redirp) != NULL) {
5424 redirp = &(redir->next);
5426 *redirp = redir = xzalloc(sizeof(*redir));
5427 /* redir->next = NULL; */
5428 /* redir->rd_filename = NULL; */
5429 redir->rd_type = style;
5430 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5432 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5433 redir_table[style].descrip);
5435 redir->rd_dup = dup_num;
5436 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5437 /* Erik had a check here that the file descriptor in question
5438 * is legit; I postpone that to "run time"
5439 * A "-" representation of "close me" shows up as a -3 here */
5440 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5441 redir->rd_fd, redir->rd_dup);
5443 /* Set ctx->pending_redirect, so we know what to do at the
5444 * end of the next parsed word. */
5445 ctx->pending_redirect = redir;
5450 /* If a redirect is immediately preceded by a number, that number is
5451 * supposed to tell which file descriptor to redirect. This routine
5452 * looks for such preceding numbers. In an ideal world this routine
5453 * needs to handle all the following classes of redirects...
5454 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5455 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5456 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5457 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5459 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5461 * ... If n is quoted, the number shall not be recognized as part of
5462 * the redirection expression. For example:
5464 * writes the character 2 into file a"
5465 * We are getting it right by setting ->o_quoted on any \<char>
5467 * A -1 return means no valid number was found,
5468 * the caller should use the appropriate default for this redirection.
5470 static int redirect_opt_num(o_string *o)
5474 if (o->data == NULL)
5476 num = bb_strtou(o->data, NULL, 10);
5477 if (errno || num < 0)
5479 o_reset_to_empty_unquoted(o);
5484 #define fetch_till_str(as_string, input, word, skip_tabs) \
5485 fetch_till_str(input, word, skip_tabs)
5487 static char *fetch_till_str(o_string *as_string,
5488 struct in_str *input,
5492 o_string heredoc = NULL_O_STRING;
5498 ch = i_getch(input);
5499 nommu_addchr(as_string, ch);
5501 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5502 heredoc.data[past_EOL] = '\0';
5503 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5504 return heredoc.data;
5507 o_addchr(&heredoc, ch);
5508 past_EOL = heredoc.length;
5511 ch = i_getch(input);
5512 nommu_addchr(as_string, ch);
5513 } while (skip_tabs && ch == '\t');
5514 } while (ch == '\n');
5517 o_free_unsafe(&heredoc);
5520 o_addchr(&heredoc, ch);
5521 nommu_addchr(as_string, ch);
5525 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5526 * and load them all. There should be exactly heredoc_cnt of them.
5528 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5530 struct pipe *pi = ctx->list_head;
5532 while (pi && heredoc_cnt) {
5534 struct command *cmd = pi->cmds;
5536 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5538 cmd->argv ? cmd->argv[0] : "NONE");
5539 for (i = 0; i < pi->num_cmds; i++) {
5540 struct redir_struct *redir = cmd->redirects;
5542 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5543 i, cmd->argv ? cmd->argv[0] : "NONE");
5545 if (redir->rd_type == REDIRECT_HEREDOC) {
5548 redir->rd_type = REDIRECT_HEREDOC2;
5549 /* redir->rd_dup is (ab)used to indicate <<- */
5550 p = fetch_till_str(&ctx->as_string, input,
5551 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5553 syntax_error("unexpected EOF in here document");
5556 free(redir->rd_filename);
5557 redir->rd_filename = p;
5560 redir = redir->next;
5567 /* Should be 0. If it isn't, it's a parse error */
5569 bb_error_msg_and_die("heredoc BUG 2");
5575 #if ENABLE_HUSH_TICK
5576 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5581 char **to_free = NULL;
5585 pid = BB_MMU ? xfork() : xvfork();
5586 if (pid == 0) { /* child */
5587 disable_restore_tty_pgrp_on_exit();
5588 /* Process substitution is not considered to be usual
5589 * 'command execution'.
5590 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5597 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5598 close(channel[0]); /* NB: close _first_, then move fd! */
5599 xmove_fd(channel[1], 1);
5600 /* Prevent it from trying to handle ctrl-z etc */
5601 IF_HUSH_JOB(G.run_list_level = 1;)
5602 /* Awful hack for `trap` or $(trap).
5604 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5605 * contains an example where "trap" is executed in a subshell:
5607 * save_traps=$(trap)
5609 * eval "$save_traps"
5611 * Standard does not say that "trap" in subshell shall print
5612 * parent shell's traps. It only says that its output
5613 * must have suitable form, but then, in the above example
5614 * (which is not supposed to be normative), it implies that.
5616 * bash (and probably other shell) does implement it
5617 * (traps are reset to defaults, but "trap" still shows them),
5618 * but as a result, "trap" logic is hopelessly messed up:
5621 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5622 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5623 * # true | trap <--- trap is in subshell - no output (ditto)
5624 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5625 * trap -- 'echo Ho' SIGWINCH
5626 * # echo `(trap)` <--- in subshell in subshell - output
5627 * trap -- 'echo Ho' SIGWINCH
5628 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5629 * trap -- 'echo Ho' SIGWINCH
5631 * The rules when to forget and when to not forget traps
5632 * get really complex and nonsensical.
5634 * Our solution: ONLY bare $(trap) or `trap` is special.
5636 s = skip_whitespace(s);
5637 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5639 static const char *const argv[] = { NULL, NULL };
5640 builtin_trap((char**)argv);
5641 exit(0); /* not _exit() - we need to fflush */
5644 reset_traps_to_defaults();
5645 parse_and_run_string(s);
5646 _exit(G.last_exitcode);
5648 /* We re-execute after vfork on NOMMU. This makes this script safe:
5649 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5650 * huge=`cat BIG` # was blocking here forever
5653 re_execute_shell(&to_free,
5663 # if ENABLE_HUSH_FAST
5665 //bb_error_msg("[%d] fork in generate_stream_from_string: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5667 enable_restore_tty_pgrp_on_exit();
5672 close_on_exec_on(channel[0]);
5673 return xfdopen_for_read(channel[0]);
5676 /* Return code is exit status of the process that is run. */
5677 static int process_command_subs(o_string *dest, const char *s)
5680 struct in_str pipe_str;
5682 int status, ch, eol_cnt;
5684 fp = generate_stream_from_string(s, &pid);
5686 /* Now send results of command back into original context */
5687 setup_file_in_str(&pipe_str, fp);
5689 while ((ch = i_getch(&pipe_str)) != EOF) {
5695 o_addchr(dest, '\n');
5698 o_addQchr(dest, ch);
5701 debug_printf("done reading from `cmd` pipe, closing it\n");
5703 /* We need to extract exitcode. Test case
5704 * "true; echo `sleep 1; false` $?"
5706 safe_waitpid(pid, &status, 0);
5707 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5708 return WEXITSTATUS(status);
5710 #endif /* ENABLE_HUSH_TICK */
5712 #if !ENABLE_HUSH_FUNCTIONS
5713 #define parse_group(dest, ctx, input, ch) \
5714 parse_group(ctx, input, ch)
5716 static int parse_group(o_string *dest, struct parse_context *ctx,
5717 struct in_str *input, int ch)
5719 /* dest contains characters seen prior to ( or {.
5720 * Typically it's empty, but for function defs,
5721 * it contains function name (without '()'). */
5722 struct pipe *pipe_list;
5724 struct command *command = ctx->command;
5726 debug_printf_parse("parse_group entered\n");
5727 #if ENABLE_HUSH_FUNCTIONS
5728 if (ch == '(' && !dest->o_quoted) {
5730 if (done_word(dest, ctx))
5733 goto skip; /* (... */
5734 if (command->argv[1]) { /* word word ... (... */
5735 syntax_error_unexpected_ch('(');
5738 /* it is "word(..." or "word (..." */
5740 ch = i_getch(input);
5741 while (ch == ' ' || ch == '\t');
5743 syntax_error_unexpected_ch(ch);
5746 nommu_addchr(&ctx->as_string, ch);
5748 ch = i_getch(input);
5749 while (ch == ' ' || ch == '\t' || ch == '\n');
5751 syntax_error_unexpected_ch(ch);
5754 nommu_addchr(&ctx->as_string, ch);
5755 command->cmd_type = CMD_FUNCDEF;
5760 #if 0 /* Prevented by caller */
5761 if (command->argv /* word [word]{... */
5762 || dest->length /* word{... */
5763 || dest->o_quoted /* ""{... */
5766 debug_printf_parse("parse_group return 1: "
5767 "syntax error, groups and arglists don't mix\n");
5772 #if ENABLE_HUSH_FUNCTIONS
5778 command->cmd_type = CMD_SUBSHELL;
5780 /* bash does not allow "{echo...", requires whitespace */
5781 ch = i_getch(input);
5782 if (ch != ' ' && ch != '\t' && ch != '\n') {
5783 syntax_error_unexpected_ch(ch);
5786 nommu_addchr(&ctx->as_string, ch);
5791 # define as_string NULL
5793 char *as_string = NULL;
5795 pipe_list = parse_stream(&as_string, input, endch);
5798 o_addstr(&ctx->as_string, as_string);
5800 /* empty ()/{} or parse error? */
5801 if (!pipe_list || pipe_list == ERR_PTR) {
5802 /* parse_stream already emitted error msg */
5805 debug_printf_parse("parse_group return 1: "
5806 "parse_stream returned %p\n", pipe_list);
5809 command->group = pipe_list;
5811 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5812 command->group_as_string = as_string;
5813 debug_printf_parse("end of group, remembering as:'%s'\n",
5814 command->group_as_string);
5818 debug_printf_parse("parse_group return 0\n");
5820 /* command remains "open", available for possible redirects */
5823 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5824 /* Subroutines for copying $(...) and `...` things */
5825 static void add_till_backquote(o_string *dest, struct in_str *input);
5827 static void add_till_single_quote(o_string *dest, struct in_str *input)
5830 int ch = i_getch(input);
5832 syntax_error_unterm_ch('\'');
5833 /*xfunc_die(); - redundant */
5840 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5841 static void add_till_double_quote(o_string *dest, struct in_str *input)
5844 int ch = i_getch(input);
5846 syntax_error_unterm_ch('"');
5847 /*xfunc_die(); - redundant */
5851 if (ch == '\\') { /* \x. Copy both chars. */
5853 ch = i_getch(input);
5857 add_till_backquote(dest, input);
5861 //if (ch == '$') ...
5864 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5866 * "Within the backquoted style of command substitution, backslash
5867 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5868 * The search for the matching backquote shall be satisfied by the first
5869 * backquote found without a preceding backslash; during this search,
5870 * if a non-escaped backquote is encountered within a shell comment,
5871 * a here-document, an embedded command substitution of the $(command)
5872 * form, or a quoted string, undefined results occur. A single-quoted
5873 * or double-quoted string that begins, but does not end, within the
5874 * "`...`" sequence produces undefined results."
5876 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5878 static void add_till_backquote(o_string *dest, struct in_str *input)
5881 int ch = i_getch(input);
5883 syntax_error_unterm_ch('`');
5884 /*xfunc_die(); - redundant */
5889 /* \x. Copy both chars unless it is \` */
5890 int ch2 = i_getch(input);
5892 syntax_error_unterm_ch('`');
5893 /*xfunc_die(); - redundant */
5895 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5902 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5903 * quoting and nested ()s.
5904 * "With the $(command) style of command substitution, all characters
5905 * following the open parenthesis to the matching closing parenthesis
5906 * constitute the command. Any valid shell script can be used for command,
5907 * except a script consisting solely of redirections which produces
5908 * unspecified results."
5910 * echo $(echo '(TEST)' BEST) (TEST) BEST
5911 * echo $(echo 'TEST)' BEST) TEST) BEST
5912 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5914 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
5915 * can contain arbitrary constructs, just like $(cmd).
5916 * In bash compat mode, it needs to also be able to stop on '}' or ':'
5917 * for ${var:N[:M]} parsing.
5919 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
5920 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
5923 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
5924 #if ENABLE_HUSH_BASH_COMPAT
5925 char end_char2 = end_ch >> 8;
5927 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
5930 ch = i_getch(input);
5932 syntax_error_unterm_ch(end_ch);
5933 /*xfunc_die(); - redundant */
5935 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
5938 /* we look for closing )) of $((EXPR)) */
5939 if (i_peek(input) == end_ch) {
5940 i_getch(input); /* eat second ')' */
5945 if (ch == '(' || ch == '{') {
5946 ch = (ch == '(' ? ')' : '}');
5947 add_till_closing_bracket(dest, input, ch);
5952 add_till_single_quote(dest, input);
5957 add_till_double_quote(dest, input);
5962 add_till_backquote(dest, input);
5967 /* \x. Copy verbatim. Important for \(, \) */
5968 ch = i_getch(input);
5970 syntax_error_unterm_ch(')');
5971 /*xfunc_die(); - redundant */
5979 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5981 /* Return code: 0 for OK, 1 for syntax error */
5983 #define parse_dollar(as_string, dest, input) \
5984 parse_dollar(dest, input)
5985 #define as_string NULL
5987 static int parse_dollar(o_string *as_string,
5989 struct in_str *input)
5991 int ch = i_peek(input); /* first character after the $ */
5992 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5994 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
5996 ch = i_getch(input);
5997 nommu_addchr(as_string, ch);
5999 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6001 debug_printf_parse(": '%c'\n", ch);
6002 o_addchr(dest, ch | quote_mask);
6005 if (!isalnum(ch) && ch != '_')
6007 ch = i_getch(input);
6008 nommu_addchr(as_string, ch);
6010 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6011 } else if (isdigit(ch)) {
6013 ch = i_getch(input);
6014 nommu_addchr(as_string, ch);
6015 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6016 debug_printf_parse(": '%c'\n", ch);
6017 o_addchr(dest, ch | quote_mask);
6018 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6019 } else switch (ch) {
6021 case '!': /* last bg pid */
6022 case '?': /* last exit code */
6023 case '#': /* number of args */
6024 case '*': /* args */
6025 case '@': /* args */
6026 goto make_one_char_var;
6028 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6030 ch = i_getch(input); /* eat '{' */
6031 nommu_addchr(as_string, ch);
6033 ch = i_getch(input); /* first char after '{' */
6034 nommu_addchr(as_string, ch);
6035 /* It should be ${?}, or ${#var},
6036 * or even ${?+subst} - operator acting on a special variable,
6037 * or the beginning of variable name.
6039 if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
6041 syntax_error_unterm_str("${name}");
6042 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
6047 /* It's possible to just call add_till_closing_bracket() at this point.
6048 * However, this regresses some of our testsuite cases
6049 * which check invalid constructs like ${%}.
6050 * Oh well... let's check that the var name part is fine... */
6056 debug_printf_parse(": '%c'\n", ch);
6058 ch = i_getch(input);
6059 nommu_addchr(as_string, ch);
6063 if (!isalnum(ch) && ch != '_') {
6065 unsigned char last_ch;
6066 /* handle parameter expansions
6067 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6069 if (!strchr("%#:-=+?", ch)) /* ${var<bad_char>... */
6070 goto bad_dollar_syntax;
6073 /* Eat everything until closing '}' (or ':') */
6075 if (ENABLE_HUSH_BASH_COMPAT
6077 && !strchr("%#:-=+?"+3, i_peek(input))
6079 /* It's ${var:N[:M]} thing */
6080 end_ch = '}' * 0x100 + ':';
6085 last_ch = add_till_closing_bracket(dest, input, end_ch);
6087 o_addstr(as_string, dest->data + pos);
6088 o_addchr(as_string, last_ch);
6091 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
6092 /* close the first block: */
6093 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6094 /* while parsing N from ${var:N[:M]}... */
6095 if ((end_ch & 0xff) == last_ch) {
6096 /* ...got ':' - parse the rest */
6100 /* ...got '}', not ':' - it's ${var:N}! emulate :999999999 */
6101 o_addstr(dest, "999999999");
6106 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6109 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6113 ch = i_getch(input);
6114 nommu_addchr(as_string, ch);
6115 # if ENABLE_SH_MATH_SUPPORT
6116 if (i_peek(input) == '(') {
6117 ch = i_getch(input);
6118 nommu_addchr(as_string, ch);
6119 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6120 o_addchr(dest, /*quote_mask |*/ '+');
6123 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
6125 o_addstr(as_string, dest->data + pos);
6126 o_addchr(as_string, ')');
6127 o_addchr(as_string, ')');
6129 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6133 # if ENABLE_HUSH_TICK
6134 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6135 o_addchr(dest, quote_mask | '`');
6138 add_till_closing_bracket(dest, input, ')');
6140 o_addstr(as_string, dest->data + pos);
6141 o_addchr(as_string, ')');
6143 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6149 ch = i_getch(input);
6150 nommu_addchr(as_string, ch);
6152 if (isalnum(ch)) { /* it's $_name or $_123 */
6157 /* TODO: $_ and $-: */
6158 /* $_ Shell or shell script name; or last argument of last command
6159 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6160 * but in command's env, set to full pathname used to invoke it */
6161 /* $- Option flags set by set builtin or shell options (-i etc) */
6163 o_addQchr(dest, '$');
6165 debug_printf_parse("parse_dollar return 0\n");
6171 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6172 parse_stream_dquoted(dest, input, dquote_end)
6173 #define as_string NULL
6175 static int parse_stream_dquoted(o_string *as_string,
6177 struct in_str *input,
6184 ch = i_getch(input);
6186 nommu_addchr(as_string, ch);
6187 if (ch == dquote_end) { /* may be only '"' or EOF */
6188 if (dest->o_assignment == NOT_ASSIGNMENT)
6189 dest->o_escape ^= 1;
6190 debug_printf_parse("parse_stream_dquoted return 0\n");
6193 /* note: can't move it above ch == dquote_end check! */
6195 syntax_error_unterm_ch('"');
6196 /*xfunc_die(); - redundant */
6200 next = i_peek(input);
6202 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6203 ch, ch, dest->o_escape);
6206 syntax_error("\\<eof>");
6210 * "The backslash retains its special meaning [in "..."]
6211 * only when followed by one of the following characters:
6212 * $, `, ", \, or <newline>. A double quote may be quoted
6213 * within double quotes by preceding it with a backslash."
6215 if (strchr("$`\"\\\n", next) != NULL) {
6216 ch = i_getch(input);
6218 o_addqchr(dest, ch);
6219 nommu_addchr(as_string, ch);
6222 o_addqchr(dest, '\\');
6223 nommu_addchr(as_string, '\\');
6228 if (parse_dollar(as_string, dest, input) != 0) {
6229 debug_printf_parse("parse_stream_dquoted return 1: "
6230 "parse_dollar returned non-0\n");
6235 #if ENABLE_HUSH_TICK
6237 //unsigned pos = dest->length;
6238 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6239 o_addchr(dest, 0x80 | '`');
6240 add_till_backquote(dest, input);
6241 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6242 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6246 o_addQchr(dest, ch);
6248 && (dest->o_assignment == MAYBE_ASSIGNMENT
6249 || dest->o_assignment == WORD_IS_KEYWORD)
6250 && is_well_formed_var_name(dest->data, '=')
6252 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6259 * Scan input until EOF or end_trigger char.
6260 * Return a list of pipes to execute, or NULL on EOF
6261 * or if end_trigger character is met.
6262 * On syntax error, exit is shell is not interactive,
6263 * reset parsing machinery and start parsing anew,
6264 * or return ERR_PTR.
6266 static struct pipe *parse_stream(char **pstring,
6267 struct in_str *input,
6270 struct parse_context ctx;
6271 o_string dest = NULL_O_STRING;
6275 /* Double-quote state is handled in the state variable is_in_dquote.
6276 * A single-quote triggers a bypass of the main loop until its mate is
6277 * found. When recursing, quote state is passed in via dest->o_escape.
6279 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6280 end_trigger ? end_trigger : 'X');
6283 /* If very first arg is "" or '', dest.data may end up NULL.
6284 * Preventing this: */
6285 o_addchr(&dest, '\0');
6288 G.ifs = get_local_var_value("IFS");
6293 #if ENABLE_HUSH_INTERACTIVE
6294 input->promptmode = 0; /* PS1 */
6296 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6297 initialize_context(&ctx);
6302 const char *is_special;
6306 redir_type redir_style;
6309 /* dest.o_quoted = 1; - already is (see below) */
6310 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6313 /* We reached closing '"' */
6316 ch = i_getch(input);
6317 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6318 ch, ch, dest.o_escape);
6323 syntax_error_unterm_str("here document");
6326 /* end_trigger == '}' case errors out earlier,
6327 * checking only ')' */
6328 if (end_trigger == ')') {
6329 syntax_error_unterm_ch('('); /* exits */
6330 /* goto parse_error; */
6333 if (done_word(&dest, &ctx)) {
6337 done_pipe(&ctx, PIPE_SEQ);
6339 /* If we got nothing... */
6340 /* (this makes bare "&" cmd a no-op.
6341 * bash says: "syntax error near unexpected token '&'") */
6342 if (pi->num_cmds == 0
6343 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6349 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6351 *pstring = ctx.as_string.data;
6353 o_free_unsafe(&ctx.as_string);
6356 debug_printf_parse("parse_stream return %p\n", pi);
6359 nommu_addchr(&ctx.as_string, ch);
6363 next = i_peek(input);
6365 is_special = "{}<>;&|()#'" /* special outside of "str" */
6366 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6367 /* Are { and } special here? */
6368 if (ctx.command->argv /* word [word]{... - non-special */
6369 || dest.length /* word{... - non-special */
6370 || dest.o_quoted /* ""{... - non-special */
6371 || (next != ';' /* }; - special */
6372 && next != ')' /* }) - special */
6373 && next != '&' /* }& and }&& ... - special */
6374 && next != '|' /* }|| ... - special */
6375 && !strchr(G.ifs, next) /* {word - non-special */
6378 /* They are not special, skip "{}" */
6381 is_special = strchr(is_special, ch);
6382 is_ifs = strchr(G.ifs, ch);
6384 if (!is_special && !is_ifs) { /* ordinary char */
6386 o_addQchr(&dest, ch);
6387 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6388 || dest.o_assignment == WORD_IS_KEYWORD)
6390 && is_well_formed_var_name(dest.data, '=')
6392 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6398 if (done_word(&dest, &ctx)) {
6402 #if ENABLE_HUSH_CASE
6403 /* "case ... in <newline> word) ..." -
6404 * newlines are ignored (but ';' wouldn't be) */
6405 if (ctx.command->argv == NULL
6406 && ctx.ctx_res_w == RES_MATCH
6411 /* Treat newline as a command separator. */
6412 done_pipe(&ctx, PIPE_SEQ);
6413 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6415 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6420 dest.o_assignment = MAYBE_ASSIGNMENT;
6422 /* note: if (is_ifs) continue;
6423 * will still trigger for us */
6427 /* "cmd}" or "cmd }..." without semicolon or &:
6428 * } is an ordinary char in this case, even inside { cmd; }
6429 * Pathological example: { ""}; } should exec "}" cmd
6432 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6433 || dest.length != 0 /* word} */
6434 || dest.o_quoted /* ""} */
6438 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6439 goto skip_end_trigger;
6440 /* else: } does terminate a group */
6443 if (end_trigger && end_trigger == ch
6444 && (ch != ';' || heredoc_cnt == 0)
6445 #if ENABLE_HUSH_CASE
6447 || ctx.ctx_res_w != RES_MATCH
6448 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6453 /* This is technically valid:
6454 * { cat <<HERE; }; echo Ok
6458 * but we don't support this.
6459 * We require heredoc to be in enclosing {}/(),
6462 syntax_error_unterm_str("here document");
6465 if (done_word(&dest, &ctx)) {
6468 done_pipe(&ctx, PIPE_SEQ);
6469 dest.o_assignment = MAYBE_ASSIGNMENT;
6470 /* Do we sit outside of any if's, loops or case's? */
6472 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6476 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6478 *pstring = ctx.as_string.data;
6480 o_free_unsafe(&ctx.as_string);
6483 debug_printf_parse("parse_stream return %p: "
6484 "end_trigger char found\n",
6486 return ctx.list_head;
6493 /* Catch <, > before deciding whether this word is
6494 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6497 redir_fd = redirect_opt_num(&dest);
6498 if (done_word(&dest, &ctx)) {
6501 redir_style = REDIRECT_OVERWRITE;
6503 redir_style = REDIRECT_APPEND;
6504 ch = i_getch(input);
6505 nommu_addchr(&ctx.as_string, ch);
6508 else if (next == '(') {
6509 syntax_error(">(process) not supported");
6513 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6515 continue; /* back to top of while (1) */
6517 redir_fd = redirect_opt_num(&dest);
6518 if (done_word(&dest, &ctx)) {
6521 redir_style = REDIRECT_INPUT;
6523 redir_style = REDIRECT_HEREDOC;
6525 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6526 ch = i_getch(input);
6527 nommu_addchr(&ctx.as_string, ch);
6528 } else if (next == '>') {
6529 redir_style = REDIRECT_IO;
6530 ch = i_getch(input);
6531 nommu_addchr(&ctx.as_string, ch);
6534 else if (next == '(') {
6535 syntax_error("<(process) not supported");
6539 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6541 continue; /* back to top of while (1) */
6544 if (dest.o_assignment == MAYBE_ASSIGNMENT
6545 /* check that we are not in word in "a=1 2>word b=1": */
6546 && !ctx.pending_redirect
6548 /* ch is a special char and thus this word
6549 * cannot be an assignment */
6550 dest.o_assignment = NOT_ASSIGNMENT;
6553 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6557 if (dest.length == 0) {
6560 if (ch == EOF || ch == '\n')
6563 /* note: we do not add it to &ctx.as_string */
6565 nommu_addchr(&ctx.as_string, '\n');
6567 o_addQchr(&dest, ch);
6572 syntax_error("\\<eof>");
6575 ch = i_getch(input);
6577 o_addchr(&dest, '\\');
6578 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6579 o_addchr(&dest, ch);
6580 nommu_addchr(&ctx.as_string, ch);
6581 /* Example: echo Hello \2>file
6582 * we need to know that word 2 is quoted */
6587 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6588 ctx.as_string.data[--ctx.as_string.length] = '\0';
6593 if (parse_dollar(&ctx.as_string, &dest, input) != 0) {
6594 debug_printf_parse("parse_stream parse error: "
6595 "parse_dollar returned non-0\n");
6602 ch = i_getch(input);
6604 syntax_error_unterm_ch('\'');
6605 /*xfunc_die(); - redundant */
6607 nommu_addchr(&ctx.as_string, ch);
6610 o_addqchr(&dest, ch);
6615 is_in_dquote ^= 1; /* invert */
6616 if (dest.o_assignment == NOT_ASSIGNMENT)
6619 #if ENABLE_HUSH_TICK
6623 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6624 o_addchr(&dest, '`');
6626 add_till_backquote(&dest, input);
6628 o_addstr(&ctx.as_string, dest.data + pos);
6629 o_addchr(&ctx.as_string, '`');
6631 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6632 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6637 #if ENABLE_HUSH_CASE
6640 if (done_word(&dest, &ctx)) {
6643 done_pipe(&ctx, PIPE_SEQ);
6644 #if ENABLE_HUSH_CASE
6645 /* Eat multiple semicolons, detect
6646 * whether it means something special */
6651 ch = i_getch(input);
6652 nommu_addchr(&ctx.as_string, ch);
6653 if (ctx.ctx_res_w == RES_CASE_BODY) {
6654 ctx.ctx_dsemicolon = 1;
6655 ctx.ctx_res_w = RES_MATCH;
6661 /* We just finished a cmd. New one may start
6662 * with an assignment */
6663 dest.o_assignment = MAYBE_ASSIGNMENT;
6666 if (done_word(&dest, &ctx)) {
6670 ch = i_getch(input);
6671 nommu_addchr(&ctx.as_string, ch);
6672 done_pipe(&ctx, PIPE_AND);
6674 done_pipe(&ctx, PIPE_BG);
6678 if (done_word(&dest, &ctx)) {
6681 #if ENABLE_HUSH_CASE
6682 if (ctx.ctx_res_w == RES_MATCH)
6683 break; /* we are in case's "word | word)" */
6685 if (next == '|') { /* || */
6686 ch = i_getch(input);
6687 nommu_addchr(&ctx.as_string, ch);
6688 done_pipe(&ctx, PIPE_OR);
6690 /* we could pick up a file descriptor choice here
6691 * with redirect_opt_num(), but bash doesn't do it.
6692 * "echo foo 2| cat" yields "foo 2". */
6695 o_reset_to_empty_unquoted(&ctx.as_string);
6700 #if ENABLE_HUSH_CASE
6701 /* "case... in [(]word)..." - skip '(' */
6702 if (ctx.ctx_res_w == RES_MATCH
6703 && ctx.command->argv == NULL /* not (word|(... */
6704 && dest.length == 0 /* not word(... */
6705 && dest.o_quoted == 0 /* not ""(... */
6711 if (parse_group(&dest, &ctx, input, ch) != 0) {
6716 #if ENABLE_HUSH_CASE
6717 if (ctx.ctx_res_w == RES_MATCH)
6721 /* proper use of this character is caught by end_trigger:
6722 * if we see {, we call parse_group(..., end_trigger='}')
6723 * and it will match } earlier (not here). */
6724 syntax_error_unexpected_ch(ch);
6728 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6734 struct parse_context *pctx;
6735 IF_HAS_KEYWORDS(struct parse_context *p2;)
6737 /* Clean up allocated tree.
6738 * Sample for finding leaks on syntax error recovery path.
6739 * Run it from interactive shell, watch pmap `pidof hush`.
6740 * while if false; then false; fi; do break; fi
6741 * Samples to catch leaks at execution:
6742 * while if (true | {true;}); then echo ok; fi; do break; done
6743 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6747 /* Update pipe/command counts,
6748 * otherwise freeing may miss some */
6749 done_pipe(pctx, PIPE_SEQ);
6750 debug_printf_clean("freeing list %p from ctx %p\n",
6751 pctx->list_head, pctx);
6752 debug_print_tree(pctx->list_head, 0);
6753 free_pipe_list(pctx->list_head);
6754 debug_printf_clean("freed list %p\n", pctx->list_head);
6756 o_free_unsafe(&pctx->as_string);
6758 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6762 IF_HAS_KEYWORDS(pctx = p2;)
6763 } while (HAS_KEYWORDS && pctx);
6764 /* Free text, clear all dest fields */
6766 /* If we are not in top-level parse, we return,
6767 * our caller will propagate error.
6769 if (end_trigger != ';') {
6777 /* Discard cached input, force prompt */
6779 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6784 /* Executing from string: eval, sh -c '...'
6785 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6786 * end_trigger controls how often we stop parsing
6787 * NUL: parse all, execute, return
6788 * ';': parse till ';' or newline, execute, repeat till EOF
6790 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6792 /* Why we need empty flag?
6793 * An obscure corner case "false; ``; echo $?":
6794 * empty command in `` should still set $? to 0.
6795 * But we can't just set $? to 0 at the start,
6796 * this breaks "false; echo `echo $?`" case.
6800 struct pipe *pipe_list;
6802 pipe_list = parse_stream(NULL, inp, end_trigger);
6803 if (!pipe_list) { /* EOF */
6805 G.last_exitcode = 0;
6808 debug_print_tree(pipe_list, 0);
6809 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6810 run_and_free_list(pipe_list);
6815 static void parse_and_run_string(const char *s)
6817 struct in_str input;
6818 setup_string_in_str(&input, s);
6819 parse_and_run_stream(&input, '\0');
6822 static void parse_and_run_file(FILE *f)
6824 struct in_str input;
6825 setup_file_in_str(&input, f);
6826 parse_and_run_stream(&input, ';');
6829 /* Called a few times only (or even once if "sh -c") */
6830 static void init_sigmasks(void)
6834 sigset_t old_blocked_set;
6836 if (!G.inherited_set_is_saved) {
6837 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6838 G.inherited_set = G.blocked_set;
6840 old_blocked_set = G.blocked_set;
6842 mask = (1 << SIGQUIT);
6843 if (G_interactive_fd) {
6844 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6845 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6846 mask |= SPECIAL_JOB_SIGS;
6848 G.non_DFL_mask = mask;
6853 sigaddset(&G.blocked_set, sig);
6857 sigdelset(&G.blocked_set, SIGCHLD);
6859 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6860 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6862 /* POSIX allows shell to re-enable SIGCHLD
6863 * even if it was SIG_IGN on entry */
6864 #if ENABLE_HUSH_FAST
6865 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6866 if (!G.inherited_set_is_saved)
6867 signal(SIGCHLD, SIGCHLD_handler);
6869 if (!G.inherited_set_is_saved)
6870 signal(SIGCHLD, SIG_DFL);
6873 G.inherited_set_is_saved = 1;
6878 static void maybe_set_to_sigexit(int sig)
6880 void (*handler)(int);
6881 /* non_DFL_mask'ed signals are, well, masked,
6882 * no need to set handler for them.
6884 if (!((G.non_DFL_mask >> sig) & 1)) {
6885 handler = signal(sig, sigexit);
6886 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6887 signal(sig, handler);
6890 /* Set handlers to restore tty pgrp and exit */
6891 static void set_fatal_handlers(void)
6893 /* We _must_ restore tty pgrp on fatal signals */
6895 maybe_set_to_sigexit(SIGILL );
6896 maybe_set_to_sigexit(SIGFPE );
6897 maybe_set_to_sigexit(SIGBUS );
6898 maybe_set_to_sigexit(SIGSEGV);
6899 maybe_set_to_sigexit(SIGTRAP);
6900 } /* else: hush is perfect. what SEGV? */
6901 maybe_set_to_sigexit(SIGABRT);
6902 /* bash 3.2 seems to handle these just like 'fatal' ones */
6903 maybe_set_to_sigexit(SIGPIPE);
6904 maybe_set_to_sigexit(SIGALRM);
6905 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6906 * if we aren't interactive... but in this case
6907 * we never want to restore pgrp on exit, and this fn is not called */
6908 /*maybe_set_to_sigexit(SIGHUP );*/
6909 /*maybe_set_to_sigexit(SIGTERM);*/
6910 /*maybe_set_to_sigexit(SIGINT );*/
6914 static int set_mode(const char cstate, const char mode)
6916 int state = (cstate == '-' ? 1 : 0);
6918 case 'n': G.fake_mode = state; break;
6919 case 'x': /*G.debug_mode = state;*/ break;
6920 default: return EXIT_FAILURE;
6922 return EXIT_SUCCESS;
6925 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6926 int hush_main(int argc, char **argv)
6928 static const struct variable const_shell_ver = {
6930 .varstr = (char*)hush_version_str,
6931 .max_len = 1, /* 0 can provoke free(name) */
6936 unsigned builtin_argc;
6938 struct variable *cur_var;
6941 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6942 G.last_exitcode = EXIT_SUCCESS;
6944 G.argv0_for_re_execing = argv[0];
6946 /* Deal with HUSH_VERSION */
6947 G.shell_ver = const_shell_ver; /* copying struct here */
6948 G.top_var = &G.shell_ver;
6949 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6950 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6951 /* Initialize our shell local variables with the values
6952 * currently living in the environment */
6953 cur_var = G.top_var;
6956 char *value = strchr(*e, '=');
6957 if (value) { /* paranoia */
6958 cur_var->next = xzalloc(sizeof(*cur_var));
6959 cur_var = cur_var->next;
6960 cur_var->varstr = *e;
6961 cur_var->max_len = strlen(*e);
6962 cur_var->flg_export = 1;
6966 /* reinstate HUSH_VERSION */
6967 debug_printf_env("putenv '%s'\n", hush_version_str);
6968 putenv((char *)hush_version_str);
6971 set_pwd_var(/*exp:*/ 1);
6972 /* bash also exports SHLVL and _,
6973 * and sets (but doesn't export) the following variables:
6975 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6976 * BASH_VERSION='3.2.0(1)-release'
6978 * MACHTYPE=i386-pc-linux-gnu
6980 * HOSTNAME=<xxxxxxxxxx>
6981 * PPID=<NNNNN> - we also do it elsewhere
6992 * PIPESTATUS=([0]="0")
6993 * HISTFILE=/<xxx>/.bash_history
6997 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6999 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7009 #if ENABLE_FEATURE_EDITING
7010 G.line_input_state = new_line_input_t(FOR_SHELL);
7012 G.global_argc = argc;
7013 G.global_argv = argv;
7014 /* Initialize some more globals to non-zero values */
7015 cmdedit_update_prompt();
7017 if (setjmp(die_jmp)) {
7018 /* xfunc has failed! die die die */
7019 /* no EXIT traps, this is an escape hatch! */
7021 hush_exit(xfunc_error_retval);
7024 /* Shell is non-interactive at first. We need to call
7025 * init_sigmasks() if we are going to execute "sh <script>",
7026 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7027 * If we later decide that we are interactive, we run init_sigmasks()
7028 * in order to intercept (more) signals.
7032 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7035 opt = getopt(argc, argv, "+c:xins"
7038 # if ENABLE_HUSH_FUNCTIONS
7048 * sh ... -c 'script'
7049 * sh ... -c 'script' ARG0 [ARG1...]
7050 * On NOMMU, if builtin_argc != 0,
7051 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7052 * "" needs to be replaced with NULL
7053 * and BARGV vector fed to builtin function.
7054 * Note: the form without ARG0 never happens:
7055 * sh ... -c 'builtin' BARGV... ""
7058 G.root_pid = getpid();
7059 G.root_ppid = getppid();
7061 G.global_argv = argv + optind;
7062 G.global_argc = argc - optind;
7064 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7065 const struct built_in_command *x;
7068 x = find_builtin(optarg);
7069 if (x) { /* paranoia */
7070 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7071 G.global_argv += builtin_argc;
7072 G.global_argv[-1] = NULL; /* replace "" */
7073 G.last_exitcode = x->b_function(argv + optind - 1);
7077 if (!G.global_argv[0]) {
7078 /* -c 'script' (no params): prevent empty $0 */
7079 G.global_argv--; /* points to argv[i] of 'script' */
7080 G.global_argv[0] = argv[0];
7082 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7084 parse_and_run_string(optarg);
7087 /* Well, we cannot just declare interactiveness,
7088 * we have to have some stuff (ctty, etc) */
7089 /* G_interactive_fd++; */
7092 /* "-s" means "read from stdin", but this is how we always
7093 * operate, so simply do nothing here. */
7096 case '<': /* "big heredoc" support */
7097 full_write1_str(optarg);
7100 unsigned long long empty_trap_mask;
7102 G.root_pid = bb_strtou(optarg, &optarg, 16);
7104 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7106 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7108 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7110 builtin_argc = bb_strtou(optarg, &optarg, 16);
7112 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7113 if (empty_trap_mask != 0) {
7116 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7117 for (sig = 1; sig < NSIG; sig++) {
7118 if (empty_trap_mask & (1LL << sig)) {
7119 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7120 sigaddset(&G.blocked_set, sig);
7123 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7125 # if ENABLE_HUSH_LOOPS
7127 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7133 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7135 # if ENABLE_HUSH_FUNCTIONS
7137 struct function *funcp = new_function(optarg);
7138 /* funcp->name is already set to optarg */
7139 /* funcp->body is set to NULL. It's a special case. */
7140 funcp->body_as_string = argv[optind];
7148 if (!set_mode('-', opt))
7152 fprintf(stderr, "Usage: sh [FILE]...\n"
7153 " or: sh -c command [args]...\n\n");
7159 } /* option parsing loop */
7162 G.root_pid = getpid();
7163 G.root_ppid = getppid();
7166 /* If we are login shell... */
7167 if (argv[0] && argv[0][0] == '-') {
7169 debug_printf("sourcing /etc/profile\n");
7170 input = fopen_for_read("/etc/profile");
7171 if (input != NULL) {
7172 close_on_exec_on(fileno(input));
7174 parse_and_run_file(input);
7177 /* bash: after sourcing /etc/profile,
7178 * tries to source (in the given order):
7179 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7180 * stopping on first found. --noprofile turns this off.
7181 * bash also sources ~/.bash_logout on exit.
7182 * If called as sh, skips .bash_XXX files.
7189 * "bash <script>" (which is never interactive (unless -i?))
7190 * sources $BASH_ENV here (without scanning $PATH).
7191 * If called as sh, does the same but with $ENV.
7193 debug_printf("running script '%s'\n", argv[optind]);
7194 G.global_argv = argv + optind;
7195 G.global_argc = argc - optind;
7196 input = xfopen_for_read(argv[optind]);
7197 close_on_exec_on(fileno(input));
7199 parse_and_run_file(input);
7200 #if ENABLE_FEATURE_CLEAN_UP
7206 /* Up to here, shell was non-interactive. Now it may become one.
7207 * NB: don't forget to (re)run init_sigmasks() as needed.
7210 /* A shell is interactive if the '-i' flag was given,
7211 * or if all of the following conditions are met:
7213 * no arguments remaining or the -s flag given
7214 * standard input is a terminal
7215 * standard output is a terminal
7216 * Refer to Posix.2, the description of the 'sh' utility.
7219 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7220 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7221 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7222 if (G_saved_tty_pgrp < 0)
7223 G_saved_tty_pgrp = 0;
7225 /* try to dup stdin to high fd#, >= 255 */
7226 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7227 if (G_interactive_fd < 0) {
7228 /* try to dup to any fd */
7229 G_interactive_fd = dup(STDIN_FILENO);
7230 if (G_interactive_fd < 0) {
7232 G_interactive_fd = 0;
7233 G_saved_tty_pgrp = 0;
7236 // TODO: track & disallow any attempts of user
7237 // to (inadvertently) close/redirect G_interactive_fd
7239 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7240 if (G_interactive_fd) {
7241 close_on_exec_on(G_interactive_fd);
7243 if (G_saved_tty_pgrp) {
7244 /* If we were run as 'hush &', sleep until we are
7245 * in the foreground (tty pgrp == our pgrp).
7246 * If we get started under a job aware app (like bash),
7247 * make sure we are now in charge so we don't fight over
7248 * who gets the foreground */
7250 pid_t shell_pgrp = getpgrp();
7251 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7252 if (G_saved_tty_pgrp == shell_pgrp)
7254 /* send TTIN to ourself (should stop us) */
7255 kill(- shell_pgrp, SIGTTIN);
7259 /* Block some signals */
7262 if (G_saved_tty_pgrp) {
7263 /* Set other signals to restore saved_tty_pgrp */
7264 set_fatal_handlers();
7265 /* Put ourselves in our own process group
7266 * (bash, too, does this only if ctty is available) */
7267 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7268 /* Grab control of the terminal */
7269 tcsetpgrp(G_interactive_fd, getpid());
7271 /* -1 is special - makes xfuncs longjmp, not exit
7272 * (we reset die_sleep = 0 whereever we [v]fork) */
7273 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7277 #elif ENABLE_HUSH_INTERACTIVE
7278 /* No job control compiled in, only prompt/line editing */
7279 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7280 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7281 if (G_interactive_fd < 0) {
7282 /* try to dup to any fd */
7283 G_interactive_fd = dup(STDIN_FILENO);
7284 if (G_interactive_fd < 0)
7286 G_interactive_fd = 0;
7289 if (G_interactive_fd) {
7290 close_on_exec_on(G_interactive_fd);
7294 /* We have interactiveness code disabled */
7298 * if interactive but not a login shell, sources ~/.bashrc
7299 * (--norc turns this off, --rcfile <file> overrides)
7302 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7303 /* note: ash and hush share this string */
7304 printf("\n\n%s %s\n"
7305 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7308 "hush - the humble shell"
7312 parse_and_run_file(stdin);
7315 #if ENABLE_FEATURE_CLEAN_UP
7316 if (G.cwd != bb_msg_unknown)
7318 cur_var = G.top_var->next;
7320 struct variable *tmp = cur_var;
7321 if (!cur_var->max_len)
7322 free(cur_var->varstr);
7323 cur_var = cur_var->next;
7327 hush_exit(G.last_exitcode);
7332 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7333 int lash_main(int argc, char **argv)
7335 bb_error_msg("lash is deprecated, please use hush instead");
7336 return hush_main(argc, argv);
7341 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7342 int msh_main(int argc, char **argv)
7344 //bb_error_msg("msh is deprecated, please use hush instead");
7345 return hush_main(argc, argv);
7353 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7358 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7365 return applet_main_func(argc, argv - argc);
7368 static int FAST_FUNC builtin_test(char **argv)
7370 return run_applet_main(argv, test_main);
7373 static int FAST_FUNC builtin_echo(char **argv)
7375 return run_applet_main(argv, echo_main);
7379 static int FAST_FUNC builtin_printf(char **argv)
7381 return run_applet_main(argv, printf_main);
7385 static char **skip_dash_dash(char **argv)
7388 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7393 static int FAST_FUNC builtin_eval(char **argv)
7395 int rcode = EXIT_SUCCESS;
7397 argv = skip_dash_dash(argv);
7399 char *str = expand_strvec_to_string(argv);
7401 * eval "echo Hi; done" ("done" is syntax error):
7402 * "echo Hi" will not execute too.
7404 parse_and_run_string(str);
7406 rcode = G.last_exitcode;
7411 static int FAST_FUNC builtin_cd(char **argv)
7415 argv = skip_dash_dash(argv);
7417 if (newdir == NULL) {
7418 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7419 * bash says "bash: cd: HOME not set" and does nothing
7422 const char *home = get_local_var_value("HOME");
7423 newdir = home ? home : "/";
7425 if (chdir(newdir)) {
7426 /* Mimic bash message exactly */
7427 bb_perror_msg("cd: %s", newdir);
7428 return EXIT_FAILURE;
7430 /* Read current dir (get_cwd(1) is inside) and set PWD.
7431 * Note: do not enforce exporting. If PWD was unset or unexported,
7432 * set it again, but do not export. bash does the same.
7434 set_pwd_var(/*exp:*/ 0);
7435 return EXIT_SUCCESS;
7438 static int FAST_FUNC builtin_exec(char **argv)
7440 argv = skip_dash_dash(argv);
7441 if (argv[0] == NULL)
7442 return EXIT_SUCCESS; /* bash does this */
7444 /* Careful: we can end up here after [v]fork. Do not restore
7445 * tty pgrp then, only top-level shell process does that */
7446 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7447 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7449 /* TODO: if exec fails, bash does NOT exit! We do.
7450 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7451 * and tcsetpgrp, and this is inherently racy.
7453 execvp_or_die(argv);
7456 static int FAST_FUNC builtin_exit(char **argv)
7458 debug_printf_exec("%s()\n", __func__);
7460 /* interactive bash:
7461 * # trap "echo EEE" EXIT
7464 * There are stopped jobs.
7465 * (if there are _stopped_ jobs, running ones don't count)
7468 # EEE (then bash exits)
7470 * we can use G.exiting = -1 as indicator "last cmd was exit"
7473 /* note: EXIT trap is run by hush_exit */
7474 argv = skip_dash_dash(argv);
7475 if (argv[0] == NULL)
7476 hush_exit(G.last_exitcode);
7477 /* mimic bash: exit 123abc == exit 255 + error msg */
7478 xfunc_error_retval = 255;
7479 /* bash: exit -2 == exit 254, no error msg */
7480 hush_exit(xatoi(argv[0]) & 0xff);
7483 static void print_escaped(const char *s)
7488 const char *p = strchrnul(s, '\'');
7489 /* print 'xxxx', possibly just '' */
7490 printf("'%.*s'", (int)(p - s), s);
7495 /* s points to '; print "'''...'''" */
7497 do putchar('\''); while (*++s == '\'');
7502 #if !ENABLE_HUSH_LOCAL
7503 #define helper_export_local(argv, exp, lvl) \
7504 helper_export_local(argv, exp)
7506 static void helper_export_local(char **argv, int exp, int lvl)
7511 /* So far we do not check that name is valid (TODO?) */
7513 if (strchr(name, '=') == NULL) {
7514 struct variable *var;
7516 var = get_local_var(name);
7517 if (exp == -1) { /* unexporting? */
7518 /* export -n NAME (without =VALUE) */
7520 var->flg_export = 0;
7521 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7523 } /* else: export -n NOT_EXISTING_VAR: no-op */
7526 if (exp == 1) { /* exporting? */
7527 /* export NAME (without =VALUE) */
7529 var->flg_export = 1;
7530 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7531 putenv(var->varstr);
7535 /* Exporting non-existing variable.
7536 * bash does not put it in environment,
7537 * but remembers that it is exported,
7538 * and does put it in env when it is set later.
7539 * We just set it to "" and export. */
7540 /* Or, it's "local NAME" (without =VALUE).
7541 * bash sets the value to "". */
7542 name = xasprintf("%s=", name);
7544 /* (Un)exporting/making local NAME=VALUE */
7545 name = xstrdup(name);
7547 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7551 static int FAST_FUNC builtin_export(char **argv)
7553 unsigned opt_unexport;
7555 #if ENABLE_HUSH_EXPORT_N
7556 /* "!": do not abort on errors */
7557 opt_unexport = getopt32(argv, "!n");
7558 if (opt_unexport == (uint32_t)-1)
7559 return EXIT_FAILURE;
7566 if (argv[0] == NULL) {
7573 /* ash emits: export VAR='VAL'
7574 * bash: declare -x VAR="VAL"
7575 * we follow ash example */
7576 const char *s = *e++;
7577 const char *p = strchr(s, '=');
7579 if (!p) /* wtf? take next variable */
7582 printf("export %.*s", (int)(p - s) + 1, s);
7583 print_escaped(p + 1);
7587 /*fflush_all(); - done after each builtin anyway */
7589 return EXIT_SUCCESS;
7592 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7594 return EXIT_SUCCESS;
7597 #if ENABLE_HUSH_LOCAL
7598 static int FAST_FUNC builtin_local(char **argv)
7600 if (G.func_nest_level == 0) {
7601 bb_error_msg("%s: not in a function", argv[0]);
7602 return EXIT_FAILURE; /* bash compat */
7604 helper_export_local(argv, 0, G.func_nest_level);
7605 return EXIT_SUCCESS;
7609 static int FAST_FUNC builtin_trap(char **argv)
7615 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7620 /* No args: print all trapped */
7621 for (i = 0; i < NSIG; ++i) {
7624 print_escaped(G.traps[i]);
7625 /* note: bash adds "SIG", but only if invoked
7626 * as "bash". If called as "sh", or if set -o posix,
7627 * then it prints short signal names.
7628 * We are printing short names: */
7629 printf(" %s\n", get_signame(i));
7632 /*fflush_all(); - done after each builtin anyway */
7633 return EXIT_SUCCESS;
7637 /* If first arg is a number: reset all specified signals */
7638 sig = bb_strtou(*argv, NULL, 10);
7644 sig = get_signum(*argv++);
7645 if (sig < 0 || sig >= NSIG) {
7647 /* Mimic bash message exactly */
7648 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7653 G.traps[sig] = xstrdup(new_cmd);
7655 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7656 get_signame(sig), sig, G.traps[sig]);
7658 /* There is no signal for 0 (EXIT) */
7663 sigaddset(&G.blocked_set, sig);
7665 /* There was a trap handler, we are removing it
7666 * (if sig has non-DFL handling,
7667 * we don't need to do anything) */
7668 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7670 sigdelset(&G.blocked_set, sig);
7673 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7677 if (!argv[1]) { /* no second arg */
7678 bb_error_msg("trap: invalid arguments");
7679 return EXIT_FAILURE;
7682 /* First arg is "-": reset all specified to default */
7683 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7684 /* Everything else: set arg as signal handler
7685 * (includes "" case, which ignores signal) */
7686 if (argv[0][0] == '-') {
7687 if (argv[0][1] == '\0') { /* "-" */
7688 /* new_cmd remains NULL: "reset these sigs" */
7691 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7694 /* else: "-something", no special meaning */
7699 goto process_sig_list;
7702 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7703 static int FAST_FUNC builtin_type(char **argv)
7705 int ret = EXIT_SUCCESS;
7711 if (0) {} /* make conditional compile easier below */
7712 /*else if (find_alias(*argv))
7713 type = "an alias";*/
7714 #if ENABLE_HUSH_FUNCTIONS
7715 else if (find_function(*argv))
7716 type = "a function";
7718 else if (find_builtin(*argv))
7719 type = "a shell builtin";
7720 else if ((path = find_in_path(*argv)) != NULL)
7723 bb_error_msg("type: %s: not found", *argv);
7728 printf("%s is %s\n", *argv, type);
7736 /* built-in 'fg' and 'bg' handler */
7737 static int FAST_FUNC builtin_fg_bg(char **argv)
7742 if (!G_interactive_fd)
7743 return EXIT_FAILURE;
7745 /* If they gave us no args, assume they want the last backgrounded task */
7747 for (pi = G.job_list; pi; pi = pi->next) {
7748 if (pi->jobid == G.last_jobid) {
7752 bb_error_msg("%s: no current job", argv[0]);
7753 return EXIT_FAILURE;
7755 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7756 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7757 return EXIT_FAILURE;
7759 for (pi = G.job_list; pi; pi = pi->next) {
7760 if (pi->jobid == jobnum) {
7764 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7765 return EXIT_FAILURE;
7767 /* TODO: bash prints a string representation
7768 * of job being foregrounded (like "sleep 1 | cat") */
7769 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7770 /* Put the job into the foreground. */
7771 tcsetpgrp(G_interactive_fd, pi->pgrp);
7774 /* Restart the processes in the job */
7775 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7776 for (i = 0; i < pi->num_cmds; i++) {
7777 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7778 pi->cmds[i].is_stopped = 0;
7780 pi->stopped_cmds = 0;
7782 i = kill(- pi->pgrp, SIGCONT);
7784 if (errno == ESRCH) {
7785 delete_finished_bg_job(pi);
7786 return EXIT_SUCCESS;
7788 bb_perror_msg("kill (SIGCONT)");
7791 if (argv[0][0] == 'f') {
7793 return checkjobs_and_fg_shell(pi);
7795 return EXIT_SUCCESS;
7799 #if ENABLE_HUSH_HELP
7800 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7802 const struct built_in_command *x;
7805 "Built-in commands:\n"
7806 "------------------\n");
7807 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7809 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7812 return EXIT_SUCCESS;
7817 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7820 const char *status_string;
7822 for (job = G.job_list; job; job = job->next) {
7823 if (job->alive_cmds == job->stopped_cmds)
7824 status_string = "Stopped";
7826 status_string = "Running";
7828 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7830 return EXIT_SUCCESS;
7835 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7840 # ifdef M_TRIM_THRESHOLD
7841 /* Optional. Reduces probability of false positives */
7844 /* Crude attempt to find where "free memory" starts,
7845 * sans fragmentation. */
7847 l = (unsigned long)p;
7850 if (l < (unsigned long)p) l = (unsigned long)p;
7853 if (!G.memleak_value)
7854 G.memleak_value = l;
7856 l -= G.memleak_value;
7863 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7868 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7871 return EXIT_SUCCESS;
7874 static int FAST_FUNC builtin_read(char **argv)
7883 /* "!": do not abort on errors.
7884 * Option string must start with "sr" to match BUILTIN_READ_xxx
7886 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7887 if (read_flags == (uint32_t)-1)
7888 return EXIT_FAILURE;
7891 r = shell_builtin_read(set_local_var_from_halves,
7893 get_local_var_value("IFS"), /* can be NULL */
7901 if ((uintptr_t)r > 1) {
7902 bb_error_msg("%s", r);
7903 r = (char*)(uintptr_t)1;
7906 return (uintptr_t)r;
7909 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7910 * built-in 'set' handler
7912 * set [-abCefhmnuvx] [-o option] [argument...]
7913 * set [+abCefhmnuvx] [+o option] [argument...]
7914 * set -- [argument...]
7917 * Implementations shall support the options in both their hyphen and
7918 * plus-sign forms. These options can also be specified as options to sh.
7920 * Write out all variables and their values: set
7921 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7922 * Turn on the -x and -v options: set -xv
7923 * Unset all positional parameters: set --
7924 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7925 * Set the positional parameters to the expansion of x, even if x expands
7926 * with a leading '-' or '+': set -- $x
7928 * So far, we only support "set -- [argument...]" and some of the short names.
7930 static int FAST_FUNC builtin_set(char **argv)
7933 char **pp, **g_argv;
7934 char *arg = *++argv;
7938 for (e = G.top_var; e; e = e->next)
7940 return EXIT_SUCCESS;
7944 if (!strcmp(arg, "--")) {
7948 if (arg[0] != '+' && arg[0] != '-')
7950 for (n = 1; arg[n]; ++n)
7951 if (set_mode(arg[0], arg[n]))
7953 } while ((arg = *++argv) != NULL);
7954 /* Now argv[0] is 1st argument */
7957 return EXIT_SUCCESS;
7960 /* NB: G.global_argv[0] ($0) is never freed/changed */
7961 g_argv = G.global_argv;
7962 if (G.global_args_malloced) {
7968 G.global_args_malloced = 1;
7969 pp = xzalloc(sizeof(pp[0]) * 2);
7970 pp[0] = g_argv[0]; /* retain $0 */
7973 /* This realloc's G.global_argv */
7974 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7981 return EXIT_SUCCESS;
7983 /* Nothing known, so abort */
7985 bb_error_msg("set: %s: invalid option", arg);
7986 return EXIT_FAILURE;
7989 static int FAST_FUNC builtin_shift(char **argv)
7992 argv = skip_dash_dash(argv);
7996 if (n >= 0 && n < G.global_argc) {
7997 if (G.global_args_malloced) {
8000 free(G.global_argv[m++]);
8003 memmove(&G.global_argv[1], &G.global_argv[n+1],
8004 G.global_argc * sizeof(G.global_argv[0]));
8005 return EXIT_SUCCESS;
8007 return EXIT_FAILURE;
8010 static int FAST_FUNC builtin_source(char **argv)
8012 char *arg_path, *filename;
8015 #if ENABLE_HUSH_FUNCTIONS
8019 argv = skip_dash_dash(argv);
8022 /* bash says: "bash: .: filename argument required" */
8023 return 2; /* bash compat */
8026 if (!strchr(filename, '/')) {
8027 arg_path = find_in_path(filename);
8029 filename = arg_path;
8031 input = fopen_or_warn(filename, "r");
8034 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8035 return EXIT_FAILURE;
8037 close_on_exec_on(fileno(input));
8039 #if ENABLE_HUSH_FUNCTIONS
8040 sv_flg = G.flag_return_in_progress;
8041 /* "we are inside sourced file, ok to use return" */
8042 G.flag_return_in_progress = -1;
8044 save_and_replace_G_args(&sv, argv);
8046 parse_and_run_file(input);
8049 restore_G_args(&sv, argv);
8050 #if ENABLE_HUSH_FUNCTIONS
8051 G.flag_return_in_progress = sv_flg;
8054 return G.last_exitcode;
8057 static int FAST_FUNC builtin_umask(char **argv)
8063 argv = skip_dash_dash(argv);
8065 mode_t old_mask = mask;
8068 rc = bb_parse_mode(argv[0], &mask);
8073 * bash: umask: 'q': invalid symbolic mode operator
8074 * bash: umask: 999: octal number out of range
8076 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8081 printf("%04o\n", (unsigned) mask);
8082 /* fall through and restore mask which we set to 0 */
8086 return !rc; /* rc != 0 - success */
8089 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8090 static int FAST_FUNC builtin_unset(char **argv)
8095 /* "!": do not abort on errors */
8096 /* "+": stop at 1st non-option */
8097 opts = getopt32(argv, "!+vf");
8098 if (opts == (unsigned)-1)
8099 return EXIT_FAILURE;
8101 bb_error_msg("unset: -v and -f are exclusive");
8102 return EXIT_FAILURE;
8108 if (!(opts & 2)) { /* not -f */
8109 if (unset_local_var(*argv)) {
8110 /* unset <nonexistent_var> doesn't fail.
8111 * Error is when one tries to unset RO var.
8112 * Message was printed by unset_local_var. */
8116 #if ENABLE_HUSH_FUNCTIONS
8126 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8127 static int FAST_FUNC builtin_wait(char **argv)
8129 int ret = EXIT_SUCCESS;
8132 argv = skip_dash_dash(argv);
8133 if (argv[0] == NULL) {
8134 /* Don't care about wait results */
8135 /* Note 1: must wait until there are no more children */
8136 /* Note 2: must be interruptible */
8138 * $ sleep 3 & sleep 6 & wait
8143 * $ sleep 3 & sleep 6 & wait
8147 * ^C <-- after ~4 sec from keyboard
8150 sigaddset(&G.blocked_set, SIGCHLD);
8151 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8154 if (errno == ECHILD)
8156 /* Wait for SIGCHLD or any other signal of interest */
8157 /* sigtimedwait with infinite timeout: */
8158 sig = sigwaitinfo(&G.blocked_set, NULL);
8160 sig = check_and_run_traps(sig);
8161 if (sig && sig != SIGCHLD) { /* see note 2 */
8167 sigdelset(&G.blocked_set, SIGCHLD);
8168 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8172 /* This is probably buggy wrt interruptible-ness */
8174 pid_t pid = bb_strtou(*argv, NULL, 10);
8176 /* mimic bash message */
8177 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8178 return EXIT_FAILURE;
8180 if (waitpid(pid, &status, 0) == pid) {
8181 if (WIFSIGNALED(status))
8182 ret = 128 + WTERMSIG(status);
8183 else if (WIFEXITED(status))
8184 ret = WEXITSTATUS(status);
8188 bb_perror_msg("wait %s", *argv);
8197 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8198 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8201 def = bb_strtou(argv[1], NULL, 10);
8202 if (errno || def < def_min || argv[2]) {
8203 bb_error_msg("%s: bad arguments", argv[0]);
8211 #if ENABLE_HUSH_LOOPS
8212 static int FAST_FUNC builtin_break(char **argv)
8215 if (G.depth_of_loop == 0) {
8216 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8217 return EXIT_SUCCESS; /* bash compat */
8219 G.flag_break_continue++; /* BC_BREAK = 1 */
8221 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8222 if (depth == UINT_MAX)
8223 G.flag_break_continue = BC_BREAK;
8224 if (G.depth_of_loop < depth)
8225 G.depth_break_continue = G.depth_of_loop;
8227 return EXIT_SUCCESS;
8230 static int FAST_FUNC builtin_continue(char **argv)
8232 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8233 return builtin_break(argv);
8237 #if ENABLE_HUSH_FUNCTIONS
8238 static int FAST_FUNC builtin_return(char **argv)
8242 if (G.flag_return_in_progress != -1) {
8243 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8244 return EXIT_FAILURE; /* bash compat */
8247 G.flag_return_in_progress = 1;
8250 * out of range: wraps around at 256, does not error out
8251 * non-numeric param:
8252 * f() { false; return qwe; }; f; echo $?
8253 * bash: return: qwe: numeric argument required <== we do this
8254 * 255 <== we also do this
8256 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);