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
50 * redirection of stdout+stderr: &> and >&
51 * brace expansion: one/{two,three,four}
52 * reserved words: function select
53 * advanced test: [[ ]]
54 * process substitution: <(list) and >(list)
57 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
58 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
59 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
61 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
62 * This is exactly equivalent to let "EXPR".
63 * $[EXPR]: synonym for $((EXPR))
64 * export builtin should be special, its arguments are assignments
65 * and therefore expansion of them should be "one-word" expansion:
66 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
68 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
69 * ls: cannot access i=a: No such file or directory
70 * ls: cannot access b: No such file or directory
71 * Note1: same applies to local builtin.
72 * Note2: bash 3.2.33(1) does this only if export word itself
74 * $ export i=`echo 'aaa bbb'`; echo "$i"
76 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
79 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
81 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
82 #include <malloc.h> /* for malloc_trim */
84 /* #include <dmalloc.h> */
89 #include "shell_common.h"
90 #include "builtin_read.h"
91 #include "builtin_ulimit.h"
94 #if ENABLE_HUSH_RANDOM_SUPPORT
97 # define CLEAR_RANDOM_T(rnd) ((void)0)
100 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
105 #define LEAK_HUNTING 0
106 #define BUILD_AS_NOMMU 0
107 /* Enable/disable sanity checks. Ok to enable in production,
108 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
109 * Keeping 1 for now even in released versions.
112 /* Slightly bigger (+200 bytes), but faster hush.
113 * So far it only enables a trick with counting SIGCHLDs and forks,
114 * which allows us to do fewer waitpid's.
115 * (we can detect a case where neither forks were done nor SIGCHLDs happened
116 * and therefore waitpid will return the same result as last time)
118 #define ENABLE_HUSH_FAST 0
123 # undef USE_FOR_NOMMU
126 # define USE_FOR_NOMMU(...) __VA_ARGS__
127 # define USE_FOR_MMU(...)
130 #define SKIP_definitions 1
131 #include "applet_tables.h"
132 #undef SKIP_definitions
134 /* STANDALONE does not make sense, and won't compile */
135 # undef CONFIG_FEATURE_SH_STANDALONE
136 # undef ENABLE_FEATURE_SH_STANDALONE
137 # undef IF_FEATURE_SH_STANDALONE
138 # undef IF_NOT_FEATURE_SH_STANDALONE
139 # define ENABLE_FEATURE_SH_STANDALONE 0
140 # define IF_FEATURE_SH_STANDALONE(...)
141 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
144 #if !ENABLE_HUSH_INTERACTIVE
145 # undef ENABLE_FEATURE_EDITING
146 # define ENABLE_FEATURE_EDITING 0
147 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
148 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
151 /* Do we support ANY keywords? */
152 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
153 # define HAS_KEYWORDS 1
154 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
155 # define IF_HAS_NO_KEYWORDS(...)
157 # define HAS_KEYWORDS 0
158 # define IF_HAS_KEYWORDS(...)
159 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
162 /* If you comment out one of these below, it will be #defined later
163 * to perform debug printfs to stderr: */
164 #define debug_printf(...) do {} while (0)
165 /* Finer-grained debug switches */
166 #define debug_printf_parse(...) do {} while (0)
167 #define debug_print_tree(a, b) do {} while (0)
168 #define debug_printf_exec(...) do {} while (0)
169 #define debug_printf_env(...) do {} while (0)
170 #define debug_printf_jobs(...) do {} while (0)
171 #define debug_printf_expand(...) 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_VAR_SYMBOL 3
185 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
187 /* This supports saving pointers malloced in vfork child,
188 * to be freed in the parent.
191 typedef struct nommu_save_t {
193 struct variable *old_vars;
195 char **argv_from_re_execing;
199 typedef enum reserved_style {
208 #if ENABLE_HUSH_LOOPS
215 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
220 /* three pseudo-keywords support contrived "case" syntax: */
221 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
222 RES_MATCH , /* "word)" */
223 RES_CASE_BODY, /* "this command is inside CASE" */
230 typedef struct o_string {
232 int length; /* position where data is appended */
234 /* Protect newly added chars against globbing
235 * (by prepending \ to *, ?, [, \) */
238 /* At least some part of the string was inside '' or "",
239 * possibly empty one: word"", wo''rd etc. */
241 smallint has_empty_slot;
242 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
245 MAYBE_ASSIGNMENT = 0,
246 DEFINITELY_ASSIGNMENT = 1,
248 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
250 /* Used for initialization: o_string foo = NULL_O_STRING; */
251 #define NULL_O_STRING { NULL }
253 /* I can almost use ordinary FILE*. Is open_memstream() universally
254 * available? Where is it documented? */
255 typedef struct in_str {
257 /* eof_flag=1: last char in ->p is really an EOF */
258 char eof_flag; /* meaningless if ->p == NULL */
260 #if ENABLE_HUSH_INTERACTIVE
262 smallint promptmode; /* 0: PS1, 1: PS2 */
265 int (*get) (struct in_str *) FAST_FUNC;
266 int (*peek) (struct in_str *) FAST_FUNC;
268 #define i_getch(input) ((input)->get(input))
269 #define i_peek(input) ((input)->peek(input))
271 /* The descrip member of this structure is only used to make
272 * debugging output pretty */
273 static const struct {
275 signed char default_fd;
278 { O_RDONLY, 0, "<" },
279 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
280 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
281 { O_CREAT|O_RDWR, 1, "<>" },
282 { O_RDONLY, 0, "<<" },
283 /* Should not be needed. Bogus default_fd helps in debugging */
284 /* { O_RDONLY, 77, "<<" }, */
287 struct redir_struct {
288 struct redir_struct *next;
289 char *rd_filename; /* filename */
290 int rd_fd; /* fd to redirect */
291 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
293 smallint rd_type; /* (enum redir_type) */
294 /* note: for heredocs, rd_filename contains heredoc delimiter,
295 * and subsequently heredoc itself; and rd_dup is a bitmask:
296 * bit 0: do we need to trim leading tabs?
297 * bit 1: is heredoc quoted (<<'delim' syntax) ?
300 typedef enum redir_type {
302 REDIRECT_OVERWRITE = 1,
305 REDIRECT_HEREDOC = 4,
306 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
309 REDIRFD_SYNTAX_ERR = -2,
310 REDIRFD_TO_FILE = -1,
311 /* otherwise, rd_fd is redirected to rd_dup */
313 HEREDOC_SKIPTABS = 1,
319 pid_t pid; /* 0 if exited */
320 int assignment_cnt; /* how many argv[i] are assignments? */
321 smallint is_stopped; /* is the command currently running? */
322 smallint cmd_type; /* CMD_xxx */
324 #define CMD_SUBSHELL 1
326 /* used for "[[ EXPR ]]" */
327 #if ENABLE_HUSH_BASH_COMPAT
328 # define CMD_SINGLEWORD_NOGLOB 2
331 /* used for "export noglob=* glob* a=`echo a b`" */
332 //#define CMD_SINGLEWORD_NOGLOB_COND 3
333 // It is hard to implement correctly, it adds significant amounts of tricky code,
334 // and all this is only useful for really obscure export statements
335 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
336 // guards the code which implements it, but I have doubts it works
337 // in all cases (especially with mixed globbed/non-globbed arguments)
339 #if ENABLE_HUSH_FUNCTIONS
340 # define CMD_FUNCDEF 3
343 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
346 char *group_as_string;
348 #if ENABLE_HUSH_FUNCTIONS
349 struct function *child_func;
350 /* This field is used to prevent a bug here:
351 * while...do f1() {a;}; f1; f1() {b;}; f1; done
352 * When we execute "f1() {a;}" cmd, we create new function and clear
353 * cmd->group, cmd->group_as_string, cmd->argv[0].
354 * When we execute "f1() {b;}", we notice that f1 exists,
355 * and that its "parent cmd" struct is still "alive",
356 * we put those fields back into cmd->xxx
357 * (struct function has ->parent_cmd ptr to facilitate that).
358 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
359 * Without this trick, loop would execute a;b;b;b;...
360 * instead of correct sequence a;b;a;b;...
361 * When command is freed, it severs the link
362 * (sets ->child_func->parent_cmd to NULL).
365 char **argv; /* command name and arguments */
366 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
367 * and on execution these are substituted with their values.
368 * Substitution can make _several_ words out of one argv[n]!
369 * Example: argv[0]=='.^C*^C.' here: echo .$*.
370 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
372 struct redir_struct *redirects; /* I/O redirections */
374 /* Is there anything in this command at all? */
375 #define IS_NULL_CMD(cmd) \
376 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
381 int num_cmds; /* total number of commands in pipe */
382 int alive_cmds; /* number of commands running (not exited) */
383 int stopped_cmds; /* number of commands alive, but stopped */
385 int jobid; /* job number */
386 pid_t pgrp; /* process group ID for the job */
387 char *cmdtext; /* name of job */
389 struct command *cmds; /* array of commands in pipe */
390 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
391 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
392 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
394 typedef enum pipe_style {
400 /* Is there anything in this pipe at all? */
401 #define IS_NULL_PIPE(pi) \
402 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
404 /* This holds pointers to the various results of parsing */
405 struct parse_context {
406 /* linked list of pipes */
407 struct pipe *list_head;
408 /* last pipe (being constructed right now) */
410 /* last command in pipe (being constructed right now) */
411 struct command *command;
412 /* last redirect in command->redirects list */
413 struct redir_struct *pending_redirect;
419 smallint ctx_inverted; /* "! cmd | cmd" */
421 smallint ctx_dsemicolon; /* ";;" seen */
423 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
425 /* group we are enclosed in:
426 * example: "if pipe1; pipe2; then pipe3; fi"
427 * when we see "if" or "then", we malloc and copy current context,
428 * and make ->stack point to it. then we parse pipeN.
429 * when closing "then" / fi" / whatever is found,
430 * we move list_head into ->stack->command->group,
431 * copy ->stack into current context, and delete ->stack.
432 * (parsing of { list } and ( list ) doesn't use this method)
434 struct parse_context *stack;
438 /* On program start, environ points to initial environment.
439 * putenv adds new pointers into it, unsetenv removes them.
440 * Neither of these (de)allocates the strings.
441 * setenv allocates new strings in malloc space and does putenv,
442 * and thus setenv is unusable (leaky) for shell's purposes */
443 #define setenv(...) setenv_is_leaky_dont_use()
445 struct variable *next;
446 char *varstr; /* points to "name=" portion */
447 #if ENABLE_HUSH_LOCAL
448 unsigned func_nest_level;
450 int max_len; /* if > 0, name is part of initial env; else name is malloced */
451 smallint flg_export; /* putenv should be done on this var */
452 smallint flg_read_only;
460 #if ENABLE_HUSH_FUNCTIONS
462 struct function *next;
464 struct command *parent_cmd;
467 char *body_as_string;
473 /* "Globals" within this file */
474 /* Sorted roughly by size (smaller offsets == smaller code) */
476 /* interactive_fd != 0 means we are an interactive shell.
477 * If we are, then saved_tty_pgrp can also be != 0, meaning
478 * that controlling tty is available. With saved_tty_pgrp == 0,
479 * job control still works, but terminal signals
480 * (^C, ^Z, ^Y, ^\) won't work at all, and background
481 * process groups can only be created with "cmd &".
482 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
483 * to give tty to the foreground process group,
484 * and will take it back when the group is stopped (^Z)
487 #if ENABLE_HUSH_INTERACTIVE
488 /* 'interactive_fd' is a fd# open to ctty, if we have one
489 * _AND_ if we decided to act interactively */
493 # define G_interactive_fd (G.interactive_fd)
495 # define G_interactive_fd 0
497 #if ENABLE_FEATURE_EDITING
498 line_input_t *line_input_state;
503 #if ENABLE_HUSH_RANDOM_SUPPORT
509 pid_t saved_tty_pgrp;
510 struct pipe *job_list;
511 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
513 # define G_saved_tty_pgrp 0
515 smallint flag_SIGINT;
516 #if ENABLE_HUSH_LOOPS
517 smallint flag_break_continue;
519 #if ENABLE_HUSH_FUNCTIONS
520 /* 0: outside of a function (or sourced file)
521 * -1: inside of a function, ok to use return builtin
522 * 1: return is invoked, skip all till end of func
524 smallint flag_return_in_progress;
527 smallint exiting; /* used to prevent EXIT trap recursion */
528 /* These four support $?, $#, and $1 */
529 smalluint last_exitcode;
530 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
531 smalluint global_args_malloced;
532 smalluint inherited_set_is_saved;
533 /* how many non-NULL argv's we have. NB: $# + 1 */
537 char *argv0_for_re_execing;
539 #if ENABLE_HUSH_LOOPS
540 unsigned depth_break_continue;
541 unsigned depth_of_loop;
545 struct variable *top_var; /* = &G.shell_ver (set in main()) */
546 struct variable shell_ver;
547 #if ENABLE_HUSH_FUNCTIONS
548 struct function *top_func;
549 # if ENABLE_HUSH_LOCAL
550 struct variable **shadowed_vars_pp;
551 unsigned func_nest_level;
554 /* Signal and trap handling */
556 unsigned count_SIGCHLD;
557 unsigned handled_SIGCHLD;
558 smallint we_have_children;
560 /* which signals have non-DFL handler (even with no traps set)? */
561 unsigned non_DFL_mask;
562 char **traps; /* char *traps[NSIG] */
563 sigset_t blocked_set;
564 sigset_t inherited_set;
566 unsigned long memleak_value;
569 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
571 #define G (*ptr_to_globals)
572 /* Not #defining name to G.name - this quickly gets unwieldy
573 * (too many defines). Also, I actually prefer to see when a variable
574 * is global, thus "G." prefix is a useful hint */
575 #define INIT_G() do { \
576 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
580 /* Function prototypes for builtins */
581 static int builtin_cd(char **argv) FAST_FUNC;
582 static int builtin_echo(char **argv) FAST_FUNC;
583 static int builtin_eval(char **argv) FAST_FUNC;
584 static int builtin_exec(char **argv) FAST_FUNC;
585 static int builtin_exit(char **argv) FAST_FUNC;
586 static int builtin_export(char **argv) FAST_FUNC;
588 static int builtin_fg_bg(char **argv) FAST_FUNC;
589 static int builtin_jobs(char **argv) FAST_FUNC;
592 static int builtin_help(char **argv) FAST_FUNC;
594 #if ENABLE_HUSH_LOCAL
595 static int builtin_local(char **argv) FAST_FUNC;
598 static int builtin_memleak(char **argv) FAST_FUNC;
601 static int builtin_printf(char **argv) FAST_FUNC;
603 static int builtin_pwd(char **argv) FAST_FUNC;
604 static int builtin_read(char **argv) FAST_FUNC;
605 static int builtin_set(char **argv) FAST_FUNC;
606 static int builtin_shift(char **argv) FAST_FUNC;
607 static int builtin_source(char **argv) FAST_FUNC;
608 static int builtin_test(char **argv) FAST_FUNC;
609 static int builtin_trap(char **argv) FAST_FUNC;
610 static int builtin_type(char **argv) FAST_FUNC;
611 static int builtin_true(char **argv) FAST_FUNC;
612 static int builtin_umask(char **argv) FAST_FUNC;
613 static int builtin_unset(char **argv) FAST_FUNC;
614 static int builtin_wait(char **argv) FAST_FUNC;
615 #if ENABLE_HUSH_LOOPS
616 static int builtin_break(char **argv) FAST_FUNC;
617 static int builtin_continue(char **argv) FAST_FUNC;
619 #if ENABLE_HUSH_FUNCTIONS
620 static int builtin_return(char **argv) FAST_FUNC;
623 /* Table of built-in functions. They can be forked or not, depending on
624 * context: within pipes, they fork. As simple commands, they do not.
625 * When used in non-forking context, they can change global variables
626 * in the parent shell process. If forked, of course they cannot.
627 * For example, 'unset foo | whatever' will parse and run, but foo will
628 * still be set at the end. */
629 struct built_in_command {
631 int (*b_function)(char **argv) FAST_FUNC;
634 # define BLTIN(cmd, func, help) { cmd, func, help }
636 # define BLTIN(cmd, func, help) { cmd, func }
640 static const struct built_in_command bltins1[] = {
641 BLTIN("." , builtin_source , "Run commands in a file"),
642 BLTIN(":" , builtin_true , NULL),
644 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
646 #if ENABLE_HUSH_LOOPS
647 BLTIN("break" , builtin_break , "Exit from a loop"),
649 BLTIN("cd" , builtin_cd , "Change directory"),
650 #if ENABLE_HUSH_LOOPS
651 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
653 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
654 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
655 BLTIN("exit" , builtin_exit , "Exit"),
656 BLTIN("export" , builtin_export , "Set environment variables"),
658 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
661 BLTIN("help" , builtin_help , NULL),
664 BLTIN("jobs" , builtin_jobs , "List jobs"),
666 #if ENABLE_HUSH_LOCAL
667 BLTIN("local" , builtin_local , "Set local variables"),
670 BLTIN("memleak" , builtin_memleak , NULL),
672 BLTIN("read" , builtin_read , "Input into variable"),
673 #if ENABLE_HUSH_FUNCTIONS
674 BLTIN("return" , builtin_return , "Return from a function"),
676 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
677 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
678 #if ENABLE_HUSH_BASH_COMPAT
679 BLTIN("source" , builtin_source , "Run commands in a file"),
681 BLTIN("trap" , builtin_trap , "Trap signals"),
682 BLTIN("type" , builtin_type , "Show command type"),
683 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
684 BLTIN("umask" , builtin_umask , "Set file creation mask"),
685 BLTIN("unset" , builtin_unset , "Unset variables"),
686 BLTIN("wait" , builtin_wait , "Wait for process"),
688 /* For now, echo and test are unconditionally enabled.
689 * Maybe make it configurable? */
690 static const struct built_in_command bltins2[] = {
691 BLTIN("[" , builtin_test , NULL),
692 BLTIN("echo" , builtin_echo , NULL),
694 BLTIN("printf" , builtin_printf , NULL),
696 BLTIN("pwd" , builtin_pwd , NULL),
697 BLTIN("test" , builtin_test , NULL),
704 /* prevent disasters with G.debug_indent < 0 */
705 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
706 # define debug_enter() (G.debug_indent++)
707 # define debug_leave() (G.debug_indent--)
709 # define indent() ((void)0)
710 # define debug_enter() ((void)0)
711 # define debug_leave() ((void)0)
715 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
718 #ifndef debug_printf_parse
719 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
722 #ifndef debug_printf_exec
723 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
726 #ifndef debug_printf_env
727 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
730 #ifndef debug_printf_jobs
731 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
732 # define DEBUG_JOBS 1
734 # define DEBUG_JOBS 0
737 #ifndef debug_printf_expand
738 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
739 # define DEBUG_EXPAND 1
741 # define DEBUG_EXPAND 0
744 #ifndef debug_printf_glob
745 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
746 # define DEBUG_GLOB 1
748 # define DEBUG_GLOB 0
751 #ifndef debug_printf_list
752 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
755 #ifndef debug_printf_subst
756 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
759 #ifndef debug_printf_clean
760 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
761 # define DEBUG_CLEAN 1
763 # define DEBUG_CLEAN 0
767 static void debug_print_strings(const char *prefix, char **vv)
770 fprintf(stderr, "%s:\n", prefix);
772 fprintf(stderr, " '%s'\n", *vv++);
775 # define debug_print_strings(prefix, vv) ((void)0)
779 /* Leak hunting. Use hush_leaktool.sh for post-processing.
782 static void *xxmalloc(int lineno, size_t size)
784 void *ptr = xmalloc((size + 0xff) & ~0xff);
785 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
788 static void *xxrealloc(int lineno, void *ptr, size_t size)
790 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
791 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
794 static char *xxstrdup(int lineno, const char *str)
796 char *ptr = xstrdup(str);
797 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
800 static void xxfree(void *ptr)
802 fdprintf(2, "free %p\n", ptr);
805 #define xmalloc(s) xxmalloc(__LINE__, s)
806 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
807 #define xstrdup(s) xxstrdup(__LINE__, s)
808 #define free(p) xxfree(p)
812 /* Syntax and runtime errors. They always abort scripts.
813 * In interactive use they usually discard unparsed and/or unexecuted commands
814 * and return to the prompt.
815 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
818 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
819 # define syntax_error(lineno, msg) syntax_error(msg)
820 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
821 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
822 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
823 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
826 static void die_if_script(unsigned lineno, const char *fmt, ...)
831 bb_error_msg("hush.c:%u", lineno);
834 bb_verror_msg(fmt, p, NULL);
836 if (!G_interactive_fd)
840 static void syntax_error(unsigned lineno, const char *msg)
843 die_if_script(lineno, "syntax error: %s", msg);
845 die_if_script(lineno, "syntax error", NULL);
848 static void syntax_error_at(unsigned lineno, const char *msg)
850 die_if_script(lineno, "syntax error at '%s'", msg);
853 static void syntax_error_unterm_str(unsigned lineno, const char *s)
855 die_if_script(lineno, "syntax error: unterminated %s", s);
858 /* It so happens that all such cases are totally fatal
859 * even if shell is interactive: EOF while looking for closing
860 * delimiter. There is nowhere to read stuff from after that,
861 * it's EOF! The only choice is to terminate.
863 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
864 static void syntax_error_unterm_ch(unsigned lineno, char ch)
866 char msg[2] = { ch, '\0' };
867 syntax_error_unterm_str(lineno, msg);
871 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
876 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
880 # undef die_if_script
882 # undef syntax_error_at
883 # undef syntax_error_unterm_ch
884 # undef syntax_error_unterm_str
885 # undef syntax_error_unexpected_ch
887 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
888 # define syntax_error(msg) syntax_error(__LINE__, msg)
889 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
890 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
891 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
892 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
896 #if ENABLE_HUSH_INTERACTIVE
897 static void cmdedit_update_prompt(void);
899 # define cmdedit_update_prompt() ((void)0)
905 /* Replace each \x with x in place, return ptr past NUL. */
906 static char *unbackslash(char *src)
908 char *dst = src = strchrnul(src, '\\');
912 if ((*dst++ = *src++) == '\0')
918 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
939 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
940 v[count1 + count2] = NULL;
943 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
947 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
949 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
950 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
953 #define add_strings_to_strings(strings, add, need_to_dup) \
954 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
957 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
958 static char **add_string_to_strings(char **strings, char *add)
963 return add_strings_to_strings(strings, v, /*dup:*/ 0);
966 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
968 char **ptr = add_string_to_strings(strings, add);
969 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
972 #define add_string_to_strings(strings, add) \
973 xx_add_string_to_strings(__LINE__, strings, add)
976 static void free_strings(char **strings)
991 /* Helpers for setting new $n and restoring them back
993 typedef struct save_arg_t {
997 smallint sv_g_malloced;
1000 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1004 sv->sv_argv0 = argv[0];
1005 sv->sv_g_argv = G.global_argv;
1006 sv->sv_g_argc = G.global_argc;
1007 sv->sv_g_malloced = G.global_args_malloced;
1009 argv[0] = G.global_argv[0]; /* retain $0 */
1010 G.global_argv = argv;
1011 G.global_args_malloced = 0;
1019 static void restore_G_args(save_arg_t *sv, char **argv)
1023 if (G.global_args_malloced) {
1024 /* someone ran "set -- arg1 arg2 ...", undo */
1026 while (*++pp) /* note: does not free $0 */
1028 free(G.global_argv);
1030 argv[0] = sv->sv_argv0;
1031 G.global_argv = sv->sv_g_argv;
1032 G.global_argc = sv->sv_g_argc;
1033 G.global_args_malloced = sv->sv_g_malloced;
1037 /* Basic theory of signal handling in shell
1038 * ========================================
1039 * This does not describe what hush does, rather, it is current understanding
1040 * what it _should_ do. If it doesn't, it's a bug.
1041 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1043 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1044 * is finished or backgrounded. It is the same in interactive and
1045 * non-interactive shells, and is the same regardless of whether
1046 * a user trap handler is installed or a shell special one is in effect.
1047 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1048 * backgrounds (i.e. stops) or kills all members of currently running
1051 * Wait builtin in interruptible by signals for which user trap is set
1052 * or by SIGINT in interactive shell.
1054 * Trap handlers will execute even within trap handlers. (right?)
1056 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1057 * except for handlers set to '' (empty string).
1059 * If job control is off, backgrounded commands ("cmd &")
1060 * have SIGINT, SIGQUIT set to SIG_IGN.
1062 * Commands which are run in command substitution ("`cmd`")
1063 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1065 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1066 * by the shell from its parent.
1068 * Signals which differ from SIG_DFL action
1069 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1072 * SIGTERM (interactive): ignore
1073 * SIGHUP (interactive):
1074 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1075 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1076 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1077 * that all pipe members are stopped. Try this in bash:
1078 * while :; do :; done - ^Z does not background it
1079 * (while :; do :; done) - ^Z backgrounds it
1080 * SIGINT (interactive): wait for last pipe, ignore the rest
1081 * of the command line, show prompt. NB: ^C does not send SIGINT
1082 * to interactive shell while shell is waiting for a pipe,
1083 * since shell is bg'ed (is not in foreground process group).
1084 * Example 1: this waits 5 sec, but does not execute ls:
1085 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1086 * Example 2: this does not wait and does not execute ls:
1087 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1088 * Example 3: this does not wait 5 sec, but executes ls:
1089 * "sleep 5; ls -l" + press ^C
1091 * (What happens to signals which are IGN on shell start?)
1092 * (What happens with signal mask on shell start?)
1094 * Implementation in hush
1095 * ======================
1096 * We use in-kernel pending signal mask to determine which signals were sent.
1097 * We block all signals which we don't want to take action immediately,
1098 * i.e. we block all signals which need to have special handling as described
1099 * above, and all signals which have traps set.
1100 * After each pipe execution, we extract any pending signals via sigtimedwait()
1103 * unsigned non_DFL_mask: a mask of such "special" signals
1104 * sigset_t blocked_set: current blocked signal set
1107 * clear bit in blocked_set unless it is also in non_DFL_mask
1108 * "trap 'cmd' SIGxxx":
1109 * set bit in blocked_set (even if 'cmd' is '')
1110 * after [v]fork, if we plan to be a shell:
1111 * unblock signals with special interactive handling
1112 * (child shell is not interactive),
1113 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1114 * after [v]fork, if we plan to exec:
1115 * POSIX says fork clears pending signal mask in child - no need to clear it.
1116 * Restore blocked signal set to one inherited by shell just prior to exec.
1118 * Note: as a result, we do not use signal handlers much. The only uses
1119 * are to count SIGCHLDs
1120 * and to restore tty pgrp on signal-induced exit.
1123 * Standard says "When a subshell is entered, traps that are not being ignored
1124 * are set to the default actions". bash interprets it so that traps which
1125 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1128 SPECIAL_INTERACTIVE_SIGS = 0
1133 SPECIAL_JOB_SIGS = 0
1141 #if ENABLE_HUSH_FAST
1142 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1145 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1151 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1152 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1153 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1154 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1156 /* Restores tty foreground process group, and exits.
1157 * May be called as signal handler for fatal signal
1158 * (will resend signal to itself, producing correct exit state)
1159 * or called directly with -EXITCODE.
1160 * We also call it if xfunc is exiting. */
1161 static void sigexit(int sig) NORETURN;
1162 static void sigexit(int sig)
1164 /* Disable all signals: job control, SIGPIPE, etc. */
1165 sigprocmask_allsigs(SIG_BLOCK);
1167 /* Careful: we can end up here after [v]fork. Do not restore
1168 * tty pgrp then, only top-level shell process does that */
1169 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1170 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1172 /* Not a signal, just exit */
1176 kill_myself_with_sig(sig); /* does not return */
1180 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1181 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1185 /* Restores tty foreground process group, and exits. */
1186 static void hush_exit(int exitcode) NORETURN;
1187 static void hush_exit(int exitcode)
1189 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1190 /* Prevent recursion:
1191 * trap "echo Hi; exit" EXIT; exit
1193 char *argv[] = { NULL, G.traps[0], NULL };
1202 sigexit(- (exitcode & 0xff));
1208 static int check_and_run_traps(int sig)
1210 static const struct timespec zero_timespec = { 0, 0 };
1211 smalluint save_rcode;
1217 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1222 if (G.traps && G.traps[sig]) {
1223 if (G.traps[sig][0]) {
1224 /* We have user-defined handler */
1225 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1226 save_rcode = G.last_exitcode;
1229 G.last_exitcode = save_rcode;
1230 } /* else: "" trap, ignoring signal */
1233 /* not a trap: special action */
1235 #if ENABLE_HUSH_FAST
1238 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1242 /* Builtin was ^C'ed, make it look prettier: */
1249 /* bash is observed to signal whole process groups,
1250 * not individual processes */
1251 for (job = G.job_list; job; job = job->next) {
1254 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1255 if (kill(- job->pgrp, SIGHUP) == 0)
1256 kill(- job->pgrp, SIGCONT);
1261 default: /* ignored: */
1262 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1270 static const char *get_cwd(int force)
1272 if (force || G.cwd == NULL) {
1273 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1274 * we must not try to free(bb_msg_unknown) */
1275 if (G.cwd == bb_msg_unknown)
1277 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1279 G.cwd = bb_msg_unknown;
1286 * Shell and environment variable support
1288 static struct variable **get_ptr_to_local_var(const char *name)
1290 struct variable **pp;
1291 struct variable *cur;
1296 while ((cur = *pp) != NULL) {
1297 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1304 static struct variable *get_local_var(const char *name)
1306 struct variable **pp = get_ptr_to_local_var(name);
1312 static const char* FAST_FUNC get_local_var_value(const char *name)
1314 struct variable **pp = get_ptr_to_local_var(name);
1316 return strchr((*pp)->varstr, '=') + 1;
1317 if (strcmp(name, "PPID") == 0)
1318 return utoa(G.root_ppid);
1319 // bash compat: UID? EUID?
1320 #if ENABLE_HUSH_RANDOM_SUPPORT
1321 if (strcmp(name, "RANDOM") == 0) {
1322 return utoa(next_random(&G.random_gen));
1328 /* str holds "NAME=VAL" and is expected to be malloced.
1329 * We take ownership of it.
1331 * 0: do not change export flag
1332 * (if creating new variable, flag will be 0)
1333 * 1: set export flag and putenv the variable
1334 * -1: clear export flag and unsetenv the variable
1335 * flg_read_only is set only when we handle -R var=val
1337 #if !BB_MMU && ENABLE_HUSH_LOCAL
1338 /* all params are used */
1339 #elif BB_MMU && ENABLE_HUSH_LOCAL
1340 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1341 set_local_var(str, flg_export, local_lvl)
1342 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1343 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1344 set_local_var(str, flg_export)
1345 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1346 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1347 set_local_var(str, flg_export, flg_read_only)
1349 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1351 struct variable **var_pp;
1352 struct variable *cur;
1356 eq_sign = strchr(str, '=');
1357 if (!eq_sign) { /* not expected to ever happen? */
1362 name_len = eq_sign - str + 1; /* including '=' */
1363 var_pp = &G.top_var;
1364 while ((cur = *var_pp) != NULL) {
1365 if (strncmp(cur->varstr, str, name_len) != 0) {
1366 var_pp = &cur->next;
1369 /* We found an existing var with this name */
1370 if (cur->flg_read_only) {
1374 bb_error_msg("%s: readonly variable", str);
1378 if (flg_export == -1) { // "&& cur->flg_export" ?
1379 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1384 #if ENABLE_HUSH_LOCAL
1385 if (cur->func_nest_level < local_lvl) {
1386 /* New variable is declared as local,
1387 * and existing one is global, or local
1388 * from enclosing function.
1389 * Remove and save old one: */
1390 *var_pp = cur->next;
1391 cur->next = *G.shadowed_vars_pp;
1392 *G.shadowed_vars_pp = cur;
1393 /* bash 3.2.33(1) and exported vars:
1395 * # f() { local z=a; env | grep ^z; }
1401 if (cur->flg_export)
1406 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1411 if (cur->max_len != 0) {
1412 if (cur->max_len >= strlen(str)) {
1413 /* This one is from startup env, reuse space */
1414 strcpy(cur->varstr, str);
1418 /* max_len == 0 signifies "malloced" var, which we can
1419 * (and has to) free */
1423 goto set_str_and_exp;
1426 /* Not found - create new variable struct */
1427 cur = xzalloc(sizeof(*cur));
1428 #if ENABLE_HUSH_LOCAL
1429 cur->func_nest_level = local_lvl;
1431 cur->next = *var_pp;
1437 cur->flg_read_only = flg_read_only;
1440 if (flg_export == 1)
1441 cur->flg_export = 1;
1442 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1443 cmdedit_update_prompt();
1444 if (cur->flg_export) {
1445 if (flg_export == -1) {
1446 cur->flg_export = 0;
1447 /* unsetenv was already done */
1449 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1450 return putenv(cur->varstr);
1456 /* Used at startup and after each cd */
1457 static void set_pwd_var(int exp)
1459 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1460 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1463 static int unset_local_var_len(const char *name, int name_len)
1465 struct variable *cur;
1466 struct variable **var_pp;
1469 return EXIT_SUCCESS;
1470 var_pp = &G.top_var;
1471 while ((cur = *var_pp) != NULL) {
1472 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1473 if (cur->flg_read_only) {
1474 bb_error_msg("%s: readonly variable", name);
1475 return EXIT_FAILURE;
1477 *var_pp = cur->next;
1478 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1479 bb_unsetenv(cur->varstr);
1480 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1481 cmdedit_update_prompt();
1485 return EXIT_SUCCESS;
1487 var_pp = &cur->next;
1489 return EXIT_SUCCESS;
1492 static int unset_local_var(const char *name)
1494 return unset_local_var_len(name, strlen(name));
1497 static void unset_vars(char **strings)
1505 const char *eq = strchrnul(*v, '=');
1506 unset_local_var_len(*v, (int)(eq - *v));
1512 #if ENABLE_SH_MATH_SUPPORT
1513 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1514 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1515 static char* FAST_FUNC endofname(const char *name)
1523 if (!is_in_name(*p))
1530 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1532 char *var = xasprintf("%s=%s", name, val);
1533 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1538 * Helpers for "var1=val1 var2=val2 cmd" feature
1540 static void add_vars(struct variable *var)
1542 struct variable *next;
1546 var->next = G.top_var;
1548 if (var->flg_export) {
1549 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1550 putenv(var->varstr);
1552 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1558 static struct variable *set_vars_and_save_old(char **strings)
1561 struct variable *old = NULL;
1567 struct variable *var_p;
1568 struct variable **var_pp;
1571 eq = strchr(*s, '=');
1574 var_pp = get_ptr_to_local_var(*s);
1577 /* Remove variable from global linked list */
1579 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1580 *var_pp = var_p->next;
1581 /* Add it to returned list */
1585 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1596 static int FAST_FUNC static_get(struct in_str *i)
1605 static int FAST_FUNC static_peek(struct in_str *i)
1610 #if ENABLE_HUSH_INTERACTIVE
1612 static void cmdedit_update_prompt(void)
1614 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1615 G.PS1 = get_local_var_value("PS1");
1618 G.PS2 = get_local_var_value("PS2");
1626 static const char* setup_prompt_string(int promptmode)
1628 const char *prompt_str;
1629 debug_printf("setup_prompt_string %d ", promptmode);
1630 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1631 /* Set up the prompt */
1632 if (promptmode == 0) { /* PS1 */
1634 /* bash uses $PWD value, even if it is set by user.
1635 * It uses current dir only if PWD is unset.
1636 * We always use current dir. */
1637 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1642 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1643 debug_printf("result '%s'\n", prompt_str);
1647 static void get_user_input(struct in_str *i)
1650 const char *prompt_str;
1652 prompt_str = setup_prompt_string(i->promptmode);
1653 #if ENABLE_FEATURE_EDITING
1654 /* Enable command line editing only while a command line
1655 * is actually being read */
1658 /* buglet: SIGINT will not make new prompt to appear _at once_,
1659 * only after <Enter>. (^C will work) */
1660 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1661 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1662 check_and_run_traps(0);
1663 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1664 i->eof_flag = (r < 0);
1665 if (i->eof_flag) { /* EOF/error detected */
1666 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1667 G.user_input_buf[1] = '\0';
1672 fputs(prompt_str, stdout);
1674 G.user_input_buf[0] = r = fgetc(i->file);
1675 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1676 //do we need check_and_run_traps(0)? (maybe only if stdin)
1677 } while (G.flag_SIGINT);
1678 i->eof_flag = (r == EOF);
1680 i->p = G.user_input_buf;
1683 #endif /* INTERACTIVE */
1685 /* This is the magic location that prints prompts
1686 * and gets data back from the user */
1687 static int FAST_FUNC file_get(struct in_str *i)
1691 /* If there is data waiting, eat it up */
1692 if (i->p && *i->p) {
1693 #if ENABLE_HUSH_INTERACTIVE
1697 if (i->eof_flag && !*i->p)
1699 /* note: ch is never NUL */
1701 /* need to double check i->file because we might be doing something
1702 * more complicated by now, like sourcing or substituting. */
1703 #if ENABLE_HUSH_INTERACTIVE
1704 if (G_interactive_fd && i->promptme && i->file == stdin) {
1707 } while (!*i->p); /* need non-empty line */
1708 i->promptmode = 1; /* PS2 */
1713 do ch = fgetc(i->file); while (ch == '\0');
1715 debug_printf("file_get: got '%c' %d\n", ch, ch);
1716 #if ENABLE_HUSH_INTERACTIVE
1723 /* All callers guarantee this routine will never
1724 * be used right after a newline, so prompting is not needed.
1726 static int FAST_FUNC file_peek(struct in_str *i)
1729 if (i->p && *i->p) {
1730 if (i->eof_flag && !i->p[1])
1733 /* note: ch is never NUL */
1735 do ch = fgetc(i->file); while (ch == '\0');
1736 i->eof_flag = (ch == EOF);
1737 i->peek_buf[0] = ch;
1738 i->peek_buf[1] = '\0';
1740 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1744 static void setup_file_in_str(struct in_str *i, FILE *f)
1746 i->peek = file_peek;
1748 #if ENABLE_HUSH_INTERACTIVE
1750 i->promptmode = 0; /* PS1 */
1756 static void setup_string_in_str(struct in_str *i, const char *s)
1758 i->peek = static_peek;
1759 i->get = static_get;
1760 #if ENABLE_HUSH_INTERACTIVE
1762 i->promptmode = 0; /* PS1 */
1772 #define B_CHUNK (32 * sizeof(char*))
1774 static void o_reset_to_empty_unquoted(o_string *o)
1782 static void o_free(o_string *o)
1785 memset(o, 0, sizeof(*o));
1788 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1793 static void o_grow_by(o_string *o, int len)
1795 if (o->length + len > o->maxlen) {
1796 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1797 o->data = xrealloc(o->data, 1 + o->maxlen);
1801 static void o_addchr(o_string *o, int ch)
1803 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1805 o->data[o->length] = ch;
1807 o->data[o->length] = '\0';
1810 static void o_addblock(o_string *o, const char *str, int len)
1813 memcpy(&o->data[o->length], str, len);
1815 o->data[o->length] = '\0';
1819 static void o_addstr(o_string *o, const char *str)
1821 o_addblock(o, str, strlen(str));
1823 static void nommu_addchr(o_string *o, int ch)
1829 # define nommu_addchr(o, str) ((void)0)
1832 static void o_addstr_with_NUL(o_string *o, const char *str)
1834 o_addblock(o, str, strlen(str) + 1);
1837 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1842 && (*str != '*' && *str != '?' && *str != '[')
1850 #undef HUSH_BRACE_EXP
1852 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1853 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1854 * Apparently, on unquoted $v bash still does globbing
1855 * ("v='*.txt'; echo $v" prints all .txt files),
1856 * but NOT brace expansion! Thus, there should be TWO independent
1857 * quoting mechanisms on $v expansion side: one protects
1858 * $v from brace expansion, and other additionally protects "$v" against globbing.
1859 * We have only second one.
1862 #ifdef HUSH_BRACE_EXP
1863 # define MAYBE_BRACES "{}"
1865 # define MAYBE_BRACES ""
1868 /* My analysis of quoting semantics tells me that state information
1869 * is associated with a destination, not a source.
1871 static void o_addqchr(o_string *o, int ch)
1874 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1879 o->data[o->length] = '\\';
1882 o->data[o->length] = ch;
1884 o->data[o->length] = '\0';
1887 static void o_addQchr(o_string *o, int ch)
1890 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1892 o->data[o->length] = '\\';
1896 o->data[o->length] = ch;
1898 o->data[o->length] = '\0';
1901 static void o_addQstr(o_string *o, const char *str, int len)
1904 o_addblock(o, str, len);
1910 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1911 if (ordinary_cnt > len) /* paranoia */
1913 o_addblock(o, str, ordinary_cnt);
1914 if (ordinary_cnt == len)
1916 str += ordinary_cnt;
1917 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1921 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1923 o->data[o->length] = '\\';
1927 o->data[o->length] = ch;
1929 o->data[o->length] = '\0';
1933 /* A special kind of o_string for $VAR and `cmd` expansion.
1934 * It contains char* list[] at the beginning, which is grown in 16 element
1935 * increments. Actual string data starts at the next multiple of 16 * (char*).
1936 * list[i] contains an INDEX (int!) into this string data.
1937 * It means that if list[] needs to grow, data needs to be moved higher up
1938 * but list[i]'s need not be modified.
1939 * NB: remembering how many list[i]'s you have there is crucial.
1940 * o_finalize_list() operation post-processes this structure - calculates
1941 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1943 #if DEBUG_EXPAND || DEBUG_GLOB
1944 static void debug_print_list(const char *prefix, o_string *o, int n)
1946 char **list = (char**)o->data;
1947 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1951 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1952 prefix, list, n, string_start, o->length, o->maxlen);
1955 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1956 o->data + (int)list[i] + string_start,
1957 o->data + (int)list[i] + string_start);
1961 const char *p = o->data + (int)list[n - 1] + string_start;
1963 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1967 # define debug_print_list(prefix, o, n) ((void)0)
1970 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1971 * in list[n] so that it points past last stored byte so far.
1972 * It returns n+1. */
1973 static int o_save_ptr_helper(o_string *o, int n)
1975 char **list = (char**)o->data;
1979 if (!o->has_empty_slot) {
1980 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1981 string_len = o->length - string_start;
1982 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1983 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1984 /* list[n] points to string_start, make space for 16 more pointers */
1985 o->maxlen += 0x10 * sizeof(list[0]);
1986 o->data = xrealloc(o->data, o->maxlen + 1);
1987 list = (char**)o->data;
1988 memmove(list + n + 0x10, list + n, string_len);
1989 o->length += 0x10 * sizeof(list[0]);
1991 debug_printf_list("list[%d]=%d string_start=%d\n",
1992 n, string_len, string_start);
1995 /* We have empty slot at list[n], reuse without growth */
1996 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1997 string_len = o->length - string_start;
1998 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1999 n, string_len, string_start);
2000 o->has_empty_slot = 0;
2002 list[n] = (char*)(ptrdiff_t)string_len;
2006 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2007 static int o_get_last_ptr(o_string *o, int n)
2009 char **list = (char**)o->data;
2010 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2012 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2015 #ifdef HUSH_BRACE_EXP
2016 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2017 * first, it processes even {a} (no commas), second,
2018 * I didn't manage to make it return strings when they don't match
2019 * existing files. Need to re-implement it.
2023 static int glob_needed(const char *s)
2032 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2038 /* Return pointer to next closing brace or to comma */
2039 static const char *next_brace_sub(const char *cp)
2043 while (*cp != '\0') {
2050 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2052 if (*cp++ == '{') /*}*/
2056 return *cp != '\0' ? cp : NULL;
2058 /* Recursive brace globber. Note: may garble pattern[]. */
2059 static int glob_brace(char *pattern, o_string *o, int n)
2061 char *new_pattern_buf;
2068 debug_printf_glob("glob_brace('%s')\n", pattern);
2074 if (*begin == '{') /*}*/ {
2075 /* Find the first sub-pattern and at the same time
2076 * find the rest after the closing brace */
2077 next = next_brace_sub(begin);
2079 /* An illegal expression */
2082 /*{*/ if (*next == '}') {
2083 /* "{abc}" with no commas - illegal
2084 * brace expr, disregard and skip it */
2090 if (*begin == '\\' && begin[1] != '\0')
2094 debug_printf_glob("begin:%s\n", begin);
2095 debug_printf_glob("next:%s\n", next);
2097 /* Now find the end of the whole brace expression */
2099 /*{*/ while (*rest != '}') {
2100 rest = next_brace_sub(rest);
2102 /* An illegal expression */
2105 debug_printf_glob("rest:%s\n", rest);
2107 rest_len = strlen(++rest) + 1;
2109 /* We are sure the brace expression is well-formed */
2111 /* Allocate working buffer large enough for our work */
2112 new_pattern_buf = xmalloc(strlen(pattern));
2114 /* We have a brace expression. BEGIN points to the opening {,
2115 * NEXT points past the terminator of the first element, and REST
2116 * points past the final }. We will accumulate result names from
2117 * recursive runs for each brace alternative in the buffer using
2122 /* Construct the new glob expression */
2125 mempcpy(new_pattern_buf,
2126 /* We know the prefix for all sub-patterns */
2127 pattern, begin - pattern),
2131 /* Note: glob_brace() may garble new_pattern_buf[].
2132 * That's why we re-copy prefix every time (1st memcpy above).
2134 n = glob_brace(new_pattern_buf, o, n);
2135 /*{*/ if (*next == '}') {
2136 /* We saw the last entry */
2140 next = next_brace_sub(next);
2142 free(new_pattern_buf);
2150 memset(&globdata, 0, sizeof(globdata));
2151 gr = glob(pattern, 0, NULL, &globdata);
2152 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2154 if (gr == GLOB_NOMATCH) {
2155 globfree(&globdata);
2156 /* NB: garbles parameter */
2157 unbackslash(pattern);
2158 o_addstr_with_NUL(o, pattern);
2159 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2160 return o_save_ptr_helper(o, n);
2162 if (gr == GLOB_NOSPACE)
2163 bb_error_msg_and_die(bb_msg_memory_exhausted);
2164 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2165 * but we didn't specify it. Paranoia again. */
2166 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2168 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2169 char **argv = globdata.gl_pathv;
2171 o_addstr_with_NUL(o, *argv);
2172 n = o_save_ptr_helper(o, n);
2178 globfree(&globdata);
2182 /* Performs globbing on last list[],
2183 * saving each result as a new list[].
2185 static int o_glob(o_string *o, int n)
2187 char *pattern, *copy;
2189 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2191 return o_save_ptr_helper(o, n);
2192 pattern = o->data + o_get_last_ptr(o, n);
2193 debug_printf_glob("glob pattern '%s'\n", pattern);
2194 if (!glob_needed(pattern)) {
2195 /* unbackslash last string in o in place, fix length */
2196 o->length = unbackslash(pattern) - o->data;
2197 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2198 return o_save_ptr_helper(o, n);
2201 copy = xstrdup(pattern);
2202 /* "forget" pattern in o */
2203 o->length = pattern - o->data;
2204 n = glob_brace(copy, o, n);
2207 debug_print_list("o_glob returning", o, n);
2214 static int glob_needed(const char *s)
2223 if (*s == '*' || *s == '[' || *s == '?')
2229 /* Performs globbing on last list[],
2230 * saving each result as a new list[].
2232 static int o_glob(o_string *o, int n)
2238 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2240 return o_save_ptr_helper(o, n);
2241 pattern = o->data + o_get_last_ptr(o, n);
2242 debug_printf_glob("glob pattern '%s'\n", pattern);
2243 if (!glob_needed(pattern)) {
2245 /* unbackslash last string in o in place, fix length */
2246 o->length = unbackslash(pattern) - o->data;
2247 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2248 return o_save_ptr_helper(o, n);
2251 memset(&globdata, 0, sizeof(globdata));
2252 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2253 * If we glob "*.\*" and don't find anything, we need
2254 * to fall back to using literal "*.*", but GLOB_NOCHECK
2255 * will return "*.\*"!
2257 gr = glob(pattern, 0, NULL, &globdata);
2258 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2260 if (gr == GLOB_NOMATCH) {
2261 globfree(&globdata);
2264 if (gr == GLOB_NOSPACE)
2265 bb_error_msg_and_die(bb_msg_memory_exhausted);
2266 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2267 * but we didn't specify it. Paranoia again. */
2268 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2270 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2271 char **argv = globdata.gl_pathv;
2272 /* "forget" pattern in o */
2273 o->length = pattern - o->data;
2275 o_addstr_with_NUL(o, *argv);
2276 n = o_save_ptr_helper(o, n);
2282 globfree(&globdata);
2284 debug_print_list("o_glob returning", o, n);
2290 /* If o->o_glob == 1, glob the string so far remembered.
2291 * Otherwise, just finish current list[] and start new */
2292 static int o_save_ptr(o_string *o, int n)
2294 if (o->o_glob) { /* if globbing is requested */
2295 /* If o->has_empty_slot, list[n] was already globbed
2296 * (if it was requested back then when it was filled)
2297 * so don't do that again! */
2298 if (!o->has_empty_slot)
2299 return o_glob(o, n); /* o_save_ptr_helper is inside */
2301 return o_save_ptr_helper(o, n);
2304 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2305 static char **o_finalize_list(o_string *o, int n)
2310 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2312 debug_print_list("finalized", o, n);
2313 debug_printf_expand("finalized n:%d\n", n);
2314 list = (char**)o->data;
2315 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2319 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2325 /* Expansion can recurse */
2326 #if ENABLE_HUSH_TICK
2327 static int process_command_subs(o_string *dest, const char *s);
2329 static char *expand_string_to_string(const char *str);
2331 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2332 parse_stream_dquoted(dest, input, dquote_end)
2334 static int parse_stream_dquoted(o_string *as_string,
2336 struct in_str *input,
2339 /* expand_strvec_to_strvec() takes a list of strings, expands
2340 * all variable references within and returns a pointer to
2341 * a list of expanded strings, possibly with larger number
2342 * of strings. (Think VAR="a b"; echo $VAR).
2343 * This new list is allocated as a single malloc block.
2344 * NULL-terminated list of char* pointers is at the beginning of it,
2345 * followed by strings themself.
2346 * Caller can deallocate entire list by single free(list). */
2348 /* Store given string, finalizing the word and starting new one whenever
2349 * we encounter IFS char(s). This is used for expanding variable values.
2350 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2351 static int expand_on_ifs(o_string *output, int n, const char *str)
2354 int word_len = strcspn(str, G.ifs);
2356 if (output->o_escape || !output->o_glob)
2357 o_addQstr(output, str, word_len);
2358 else /* protect backslashes against globbing up :) */
2359 o_addblock_duplicate_backslash(output, str, word_len);
2362 if (!*str) /* EOL - do not finalize word */
2364 o_addchr(output, '\0');
2365 debug_print_list("expand_on_ifs", output, n);
2366 n = o_save_ptr(output, n);
2367 str += strspn(str, G.ifs); /* skip ifs chars */
2369 debug_print_list("expand_on_ifs[1]", output, n);
2373 /* Helper to expand $((...)) and heredoc body. These act as if
2374 * they are in double quotes, with the exception that they are not :).
2375 * Just the rules are similar: "expand only $var and `cmd`"
2377 * Returns malloced string.
2378 * As an optimization, we return NULL if expansion is not needed.
2380 static char *expand_pseudo_dquoted(const char *str)
2383 struct in_str input;
2384 o_string dest = NULL_O_STRING;
2386 if (strchr(str, '$') == NULL
2387 #if ENABLE_HUSH_TICK
2388 && strchr(str, '`') == NULL
2394 /* We need to expand. Example:
2395 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2397 setup_string_in_str(&input, str);
2398 parse_stream_dquoted(NULL, &dest, &input, EOF);
2399 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2400 exp_str = expand_string_to_string(dest.data);
2401 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2402 o_free_unsafe(&dest);
2406 #if ENABLE_SH_MATH_SUPPORT
2407 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
2409 arith_eval_hooks_t hooks;
2413 hooks.lookupvar = get_local_var_value;
2414 hooks.setvar = set_local_var_from_halves;
2415 hooks.endofname = endofname;
2416 exp_str = expand_pseudo_dquoted(arg);
2417 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
2423 /* Expand all variable references in given string, adding words to list[]
2424 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2425 * to be filled). This routine is extremely tricky: has to deal with
2426 * variables/parameters with whitespace, $* and $@, and constructs like
2427 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2428 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2430 /* or_mask is either 0 (normal case) or 0x80 -
2431 * expansion of right-hand side of assignment == 1-element expand.
2432 * It will also do no globbing, and thus we must not backslash-quote!
2439 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2440 debug_print_list("expand_vars_to_list", output, n);
2441 n = o_save_ptr(output, n);
2442 debug_print_list("expand_vars_to_list[0]", output, n);
2444 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2447 char *to_be_freed = NULL;
2448 const char *val = NULL;
2449 #if ENABLE_HUSH_TICK
2450 o_string subst_result = NULL_O_STRING;
2452 #if ENABLE_SH_MATH_SUPPORT
2453 char arith_buf[sizeof(arith_t)*3 + 2];
2455 o_addblock(output, arg, p - arg);
2456 debug_print_list("expand_vars_to_list[1]", output, n);
2458 p = strchr(p, SPECIAL_VAR_SYMBOL);
2460 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2461 /* "$@" is special. Even if quoted, it can still
2462 * expand to nothing (not even an empty string) */
2463 if ((first_ch & 0x7f) != '@')
2464 ored_ch |= first_ch;
2466 switch (first_ch & 0x7f) {
2467 /* Highest bit in first_ch indicates that var is double-quoted */
2469 val = utoa(G.root_pid);
2471 case '!': /* bg pid */
2472 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2474 case '?': /* exitcode */
2475 val = utoa(G.last_exitcode);
2477 case '#': /* argc */
2478 if (arg[1] != SPECIAL_VAR_SYMBOL)
2479 /* actually, it's a ${#var} */
2481 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2486 if (!G.global_argv[i])
2488 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2489 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2490 smallint sv = output->o_escape;
2491 /* unquoted var's contents should be globbed, so don't escape */
2492 output->o_escape = 0;
2493 while (G.global_argv[i]) {
2494 n = expand_on_ifs(output, n, G.global_argv[i]);
2495 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2496 if (G.global_argv[i++][0] && G.global_argv[i]) {
2497 /* this argv[] is not empty and not last:
2498 * put terminating NUL, start new word */
2499 o_addchr(output, '\0');
2500 debug_print_list("expand_vars_to_list[2]", output, n);
2501 n = o_save_ptr(output, n);
2502 debug_print_list("expand_vars_to_list[3]", output, n);
2505 output->o_escape = sv;
2507 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2508 * and in this case should treat it like '$*' - see 'else...' below */
2509 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2511 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2512 if (++i >= G.global_argc)
2514 o_addchr(output, '\0');
2515 debug_print_list("expand_vars_to_list[4]", output, n);
2516 n = o_save_ptr(output, n);
2518 } else { /* quoted $*: add as one word */
2520 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2521 if (!G.global_argv[++i])
2524 o_addchr(output, G.ifs[0]);
2528 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2529 /* "Empty variable", used to make "" etc to not disappear */
2533 #if ENABLE_HUSH_TICK
2534 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2537 /* Can't just stuff it into output o_string,
2538 * expanded result may need to be globbed
2539 * and $IFS-splitted */
2540 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2541 G.last_exitcode = process_command_subs(&subst_result, arg);
2542 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2543 val = subst_result.data;
2546 #if ENABLE_SH_MATH_SUPPORT
2547 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2551 arg++; /* skip '+' */
2552 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2553 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2554 res = expand_and_evaluate_arith(arg, &errcode);
2557 const char *msg = "error in arithmetic";
2560 msg = "exponent less than 0";
2563 msg = "divide by 0";
2566 msg = "expression recursion loop detected";
2571 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2572 sprintf(arith_buf, arith_t_fmt, res);
2577 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2580 char exp_len; /* '#' if it's ${#var} */
2582 char exp_save = exp_save; /* for compiler */
2583 char *exp_saveptr = exp_saveptr; /* points to expansion operator */
2584 char *exp_word = exp_word; /* for compiler */
2587 arg[0] = first_ch & 0x7f;
2589 /* prepare for expansions */
2592 if (exp_len == '#') {
2593 /* handle length expansion ${#var} */
2596 /* maybe handle parameter expansion */
2597 exp_saveptr = var + strcspn(var, "%#:-=+?");
2598 exp_save = *exp_saveptr;
2600 exp_word = exp_saveptr;
2601 if (exp_save == ':')
2603 exp_op = *exp_word++;
2604 *exp_saveptr = '\0';
2608 /* lookup the variable in question */
2609 if (isdigit(var[0])) {
2610 /* handle_dollar() should have vetted var for us */
2612 if (i < G.global_argc)
2613 val = G.global_argv[i];
2614 /* else val remains NULL: $N with too big N */
2616 val = get_local_var_value(var);
2618 /* handle any expansions */
2619 if (exp_len == '#') {
2620 debug_printf_expand("expand: length(%s)=", val);
2621 val = utoa(val ? strlen(val) : 0);
2622 debug_printf_expand("%s\n", val);
2623 } else if (exp_op) {
2624 if (exp_op == '%' || exp_op == '#') {
2625 /* Standard-mandated substring removal ops:
2626 * ${parameter%word} - remove smallest suffix pattern
2627 * ${parameter%%word} - remove largest suffix pattern
2628 * ${parameter#word} - remove smallest prefix pattern
2629 * ${parameter##word} - remove largest prefix pattern
2631 * Word is expanded to produce a glob pattern.
2632 * Then var's value is matched to it and matching part removed.
2637 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2638 if (exp_op == *exp_word) /* ## or %% */
2640 val = to_be_freed = xstrdup(val);
2641 loc = scan(to_be_freed, exp_word, match_at_left);
2642 if (match_at_left) /* # or ## */
2644 else if (loc) /* % or %% and match was found */
2647 } else if (!strchr("%#:-=+?"+3, exp_op)) {
2648 #if ENABLE_HUSH_BASH_COMPAT
2649 /* exp_op is ':' and next char isn't a subst operator.
2650 * Assuming it's ${var:[N][:M]} bashism.
2651 * TODO: N, M can be expressions similar to $((EXPR)): 2+2, 2+var etc
2654 unsigned len = INT_MAX;
2657 if (*exp_word != ':') /* not ${var::...} */
2658 beg = bb_strtou(exp_word, &end, 0);
2659 //bb_error_msg("beg:'%s'=%u end:'%s'", exp_word, beg, end);
2661 if (end[1] != '\0') /* not ${var:NUM:} */
2662 len = bb_strtou(end + 1, &end, 0);
2667 //bb_error_msg("len:%u end:'%s'", len, end);
2670 //bb_error_msg("from val:'%s'", val);
2671 if (len == 0 || !val || beg >= strlen(val))
2674 val = to_be_freed = xstrndup(val + beg, len);
2675 //bb_error_msg("val:'%s'", val);
2679 die_if_script("malformed ${%s...}", var);
2682 } else { /* one of "-=+?" */
2683 /* Standard-mandated substitution ops:
2684 * ${var?word} - indicate error if unset
2685 * If var is unset, word (or a message indicating it is unset
2686 * if word is null) is written to standard error
2687 * and the shell exits with a non-zero exit status.
2688 * Otherwise, the value of var is substituted.
2689 * ${var-word} - use default value
2690 * If var is unset, word is substituted.
2691 * ${var=word} - assign and use default value
2692 * If var is unset, word is assigned to var.
2693 * In all cases, final value of var is substituted.
2694 * ${var+word} - use alternative value
2695 * If var is unset, null is substituted.
2696 * Otherwise, word is substituted.
2698 * Word is subjected to tilde expansion, parameter expansion,
2699 * command substitution, and arithmetic expansion.
2700 * If word is not needed, it is not expanded.
2702 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2703 * but also treat null var as if it is unset.
2705 int use_word = (!val || ((exp_save == ':') && !val[0]));
2707 use_word = !use_word;
2708 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2709 (exp_save == ':') ? "true" : "false", use_word);
2711 to_be_freed = expand_pseudo_dquoted(exp_word);
2713 exp_word = to_be_freed;
2714 if (exp_op == '?') {
2715 /* mimic bash message */
2716 die_if_script("%s: %s",
2718 exp_word[0] ? exp_word : "parameter null or not set"
2720 //TODO: how interactive bash aborts expansion mid-command?
2725 if (exp_op == '=') {
2726 /* ${var=[word]} or ${var:=[word]} */
2727 if (isdigit(var[0]) || var[0] == '#') {
2728 /* mimic bash message */
2729 die_if_script("$%s: cannot assign in this way", var);
2732 char *new_var = xasprintf("%s=%s", var, val);
2733 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2739 *exp_saveptr = exp_save;
2743 #if ENABLE_HUSH_TICK
2746 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2747 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2749 /* unquoted var's contents should be globbed, so don't escape */
2750 smallint sv = output->o_escape;
2751 output->o_escape = 0;
2752 n = expand_on_ifs(output, n, val);
2754 output->o_escape = sv;
2756 } else { /* quoted $VAR, val will be appended below */
2757 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2760 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2763 o_addQstr(output, val, strlen(val));
2766 /* Do the check to avoid writing to a const string */
2767 if (*p != SPECIAL_VAR_SYMBOL)
2768 *p = SPECIAL_VAR_SYMBOL;
2770 #if ENABLE_HUSH_TICK
2771 o_free(&subst_result);
2774 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2777 debug_print_list("expand_vars_to_list[a]", output, n);
2778 /* this part is literal, and it was already pre-quoted
2779 * if needed (much earlier), do not use o_addQstr here! */
2780 o_addstr_with_NUL(output, arg);
2781 debug_print_list("expand_vars_to_list[b]", output, n);
2782 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2783 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2786 /* allow to reuse list[n] later without re-growth */
2787 output->has_empty_slot = 1;
2789 o_addchr(output, '\0');
2794 static char **expand_variables(char **argv, int or_mask)
2799 o_string output = NULL_O_STRING;
2801 if (or_mask & 0x100) {
2802 output.o_escape = 1; /* protect against globbing for "$var" */
2803 /* (unquoted $var will temporarily switch it off) */
2810 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2813 debug_print_list("expand_variables", &output, n);
2815 /* output.data (malloced in one block) gets returned in "list" */
2816 list = o_finalize_list(&output, n);
2817 debug_print_strings("expand_variables[1]", list);
2821 static char **expand_strvec_to_strvec(char **argv)
2823 return expand_variables(argv, 0x100);
2826 #if ENABLE_HUSH_BASH_COMPAT
2827 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2829 return expand_variables(argv, 0x80);
2833 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2834 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2839 o_string output = NULL_O_STRING;
2844 int is_var = is_well_formed_var_name(*v, '=');
2845 /* is_var * 0x80: singleword expansion for vars */
2846 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2848 /* Subtle! expand_vars_to_list did not glob last word yet.
2849 * It does this only when fed with further data.
2850 * Therefore we set globbing flags AFTER it, not before:
2853 /* if it is not recognizably abc=...; then: */
2854 output.o_escape = !is_var; /* protect against globbing for "$var" */
2855 /* (unquoted $var will temporarily switch it off) */
2856 output.o_glob = !is_var; /* and indeed do globbing */
2859 debug_print_list("expand_cond", &output, n);
2861 /* output.data (malloced in one block) gets returned in "list" */
2862 list = o_finalize_list(&output, n);
2863 debug_print_strings("expand_cond[1]", list);
2868 /* Used for expansion of right hand of assignments */
2869 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2871 static char *expand_string_to_string(const char *str)
2873 char *argv[2], **list;
2875 argv[0] = (char*)str;
2877 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2879 if (!list[0] || list[1])
2880 bb_error_msg_and_die("BUG in varexp2");
2881 /* actually, just move string 2*sizeof(char*) bytes back */
2882 overlapping_strcpy((char*)list, list[0]);
2883 unbackslash((char*)list);
2884 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2888 /* Used for "eval" builtin */
2889 static char* expand_strvec_to_string(char **argv)
2893 list = expand_variables(argv, 0x80);
2894 /* Convert all NULs to spaces */
2899 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2900 bb_error_msg_and_die("BUG in varexp3");
2901 /* bash uses ' ' regardless of $IFS contents */
2906 overlapping_strcpy((char*)list, list[0]);
2907 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2911 static char **expand_assignments(char **argv, int count)
2915 /* Expand assignments into one string each */
2916 for (i = 0; i < count; i++) {
2917 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2925 void re_execute_shell(char ***to_free, const char *s,
2926 char *g_argv0, char **g_argv,
2927 char **builtin_argv) NORETURN;
2929 static void reset_traps_to_defaults(void)
2931 /* This function is always called in a child shell
2932 * after fork (not vfork, NOMMU doesn't use this function).
2937 /* Child shells are not interactive.
2938 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2939 * Testcase: (while :; do :; done) + ^Z should background.
2940 * Same goes for SIGTERM, SIGHUP, SIGINT.
2942 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2943 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2945 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2946 * Stupid. It can be done with *single* &= op, but we can't use
2947 * the fact that G.blocked_set is implemented as a bitmask
2949 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2953 /* Careful. Only if no trap or trap is not "" */
2954 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2955 sigdelset(&G.blocked_set, sig);
2962 /* Our homegrown sig mask is saner to work with :) */
2963 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2965 /* Resetting all traps to default except empty ones */
2966 mask = G.non_DFL_mask;
2967 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2968 if (!G.traps[sig] || !G.traps[sig][0])
2971 G.traps[sig] = NULL;
2972 /* There is no signal for 0 (EXIT) */
2975 /* There was a trap handler, we just removed it.
2976 * But if sig still has non-DFL handling,
2977 * we should not unblock the sig. */
2980 sigdelset(&G.blocked_set, sig);
2982 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2987 static void re_execute_shell(char ***to_free, const char *s,
2988 char *g_argv0, char **g_argv,
2989 char **builtin_argv) NORETURN;
2990 static void re_execute_shell(char ***to_free, const char *s,
2991 char *g_argv0, char **g_argv,
2992 char **builtin_argv)
2994 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
2995 /* delims + 2 * (number of bytes in printed hex numbers) */
2996 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
2997 char *heredoc_argv[4];
2998 struct variable *cur;
2999 # if ENABLE_HUSH_FUNCTIONS
3000 struct function *funcp;
3004 unsigned long long empty_trap_mask;
3006 if (!g_argv0) { /* heredoc */
3007 argv = heredoc_argv;
3008 argv[0] = (char *) G.argv0_for_re_execing;
3009 argv[1] = (char *) "-<";
3010 argv[2] = (char *) s;
3012 pp = &argv[3]; /* used as pointer to empty environment */
3018 if (pp) while (*pp++)
3021 empty_trap_mask = 0;
3024 for (sig = 1; sig < NSIG; sig++) {
3025 if (G.traps[sig] && !G.traps[sig][0])
3026 empty_trap_mask |= 1LL << sig;
3030 sprintf(param_buf, NOMMU_HACK_FMT
3031 , (unsigned) G.root_pid
3032 , (unsigned) G.root_ppid
3033 , (unsigned) G.last_bg_pid
3034 , (unsigned) G.last_exitcode
3037 IF_HUSH_LOOPS(, G.depth_of_loop)
3039 #undef NOMMU_HACK_FMT
3040 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3041 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3044 for (cur = G.top_var; cur; cur = cur->next) {
3045 if (!cur->flg_export || cur->flg_read_only)
3048 # if ENABLE_HUSH_FUNCTIONS
3049 for (funcp = G.top_func; funcp; funcp = funcp->next)
3055 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3056 *pp++ = (char *) G.argv0_for_re_execing;
3058 for (cur = G.top_var; cur; cur = cur->next) {
3059 if (cur->varstr == hush_version_str)
3061 if (cur->flg_read_only) {
3062 *pp++ = (char *) "-R";
3063 *pp++ = cur->varstr;
3064 } else if (!cur->flg_export) {
3065 *pp++ = (char *) "-V";
3066 *pp++ = cur->varstr;
3069 # if ENABLE_HUSH_FUNCTIONS
3070 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3071 *pp++ = (char *) "-F";
3072 *pp++ = funcp->name;
3073 *pp++ = funcp->body_as_string;
3076 /* We can pass activated traps here. Say, -Tnn:trap_string
3078 * However, POSIX says that subshells reset signals with traps
3080 * I tested bash-3.2 and it not only does that with true subshells
3081 * of the form ( list ), but with any forked children shells.
3082 * I set trap "echo W" WINCH; and then tried:
3084 * { echo 1; sleep 20; echo 2; } &
3085 * while true; do echo 1; sleep 20; echo 2; break; done &
3086 * true | { echo 1; sleep 20; echo 2; } | cat
3088 * In all these cases sending SIGWINCH to the child shell
3089 * did not run the trap. If I add trap "echo V" WINCH;
3090 * _inside_ group (just before echo 1), it works.
3092 * I conclude it means we don't need to pass active traps here.
3093 * Even if we would use signal handlers instead of signal masking
3094 * in order to implement trap handling,
3095 * exec syscall below resets signals to SIG_DFL for us.
3097 *pp++ = (char *) "-c";
3100 while (*++builtin_argv)
3101 *pp++ = *builtin_argv;
3102 *pp++ = (char *) "";
3107 /* *pp = NULL; - is already there */
3111 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3112 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3113 execve(bb_busybox_exec_path, argv, pp);
3114 /* Fallback. Useful for init=/bin/hush usage etc */
3115 if (argv[0][0] == '/')
3116 execve(argv[0], argv, pp);
3117 xfunc_error_retval = 127;
3118 bb_error_msg_and_die("can't re-execute the shell");
3120 #endif /* !BB_MMU */
3123 static void setup_heredoc(struct redir_struct *redir)
3125 struct fd_pair pair;
3128 /* the _body_ of heredoc (misleading field name) */
3129 const char *heredoc = redir->rd_filename;
3136 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3137 expanded = expand_pseudo_dquoted(heredoc);
3141 len = strlen(heredoc);
3143 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3145 xmove_fd(pair.rd, redir->rd_fd);
3147 /* Try writing without forking. Newer kernels have
3148 * dynamically growing pipes. Must use non-blocking write! */
3151 written = write(pair.wr, heredoc, len);
3162 ndelay_off(pair.wr);
3164 /* Okay, pipe buffer was not big enough */
3165 /* Note: we must not create a stray child (bastard? :)
3166 * for the unsuspecting parent process. Child creates a grandchild
3167 * and exits before parent execs the process which consumes heredoc
3168 * (that exec happens after we return from this function) */
3174 bb_perror_msg_and_die("vfork");
3177 disable_restore_tty_pgrp_on_exit();
3178 pid = BB_MMU ? fork() : vfork();
3180 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3184 close(redir->rd_fd); /* read side of the pipe */
3186 full_write(pair.wr, heredoc, len); /* may loop or block */
3189 /* Delegate blocking writes to another process */
3190 xmove_fd(pair.wr, STDOUT_FILENO);
3191 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3195 #if ENABLE_HUSH_FAST
3197 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3199 enable_restore_tty_pgrp_on_exit();
3205 wait(NULL); /* wait till child has died */
3208 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3209 * and stderr if they are redirected. */
3210 static int setup_redirects(struct command *prog, int squirrel[])
3213 struct redir_struct *redir;
3215 for (redir = prog->redirects; redir; redir = redir->next) {
3216 if (redir->rd_type == REDIRECT_HEREDOC2) {
3217 /* rd_fd<<HERE case */
3218 if (squirrel && redir->rd_fd < 3
3219 && squirrel[redir->rd_fd] < 0
3221 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3223 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3225 debug_printf_parse("set heredoc '%s'\n",
3226 redir->rd_filename);
3227 setup_heredoc(redir);
3231 if (redir->rd_dup == REDIRFD_TO_FILE) {
3232 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3234 if (redir->rd_filename == NULL) {
3235 /* Something went wrong in the parse.
3236 * Pretend it didn't happen */
3237 bb_error_msg("bug in redirect parse");
3240 mode = redir_table[redir->rd_type].mode;
3241 p = expand_string_to_string(redir->rd_filename);
3242 openfd = open_or_warn(p, mode);
3245 /* this could get lost if stderr has been redirected, but
3246 * bash and ash both lose it as well (though zsh doesn't!) */
3247 //what the above comment tries to say?
3251 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3252 openfd = redir->rd_dup;
3255 if (openfd != redir->rd_fd) {
3256 if (squirrel && redir->rd_fd < 3
3257 && squirrel[redir->rd_fd] < 0
3259 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3261 if (openfd == REDIRFD_CLOSE) {
3262 /* "n>-" means "close me" */
3263 close(redir->rd_fd);
3265 xdup2(openfd, redir->rd_fd);
3266 if (redir->rd_dup == REDIRFD_TO_FILE)
3274 static void restore_redirects(int squirrel[])
3277 for (i = 0; i < 3; i++) {
3280 /* We simply die on error */
3287 static void free_pipe_list(struct pipe *head);
3289 /* Return code is the exit status of the pipe */
3290 static void free_pipe(struct pipe *pi)
3293 struct command *command;
3294 struct redir_struct *r, *rnext;
3297 if (pi->stopped_cmds > 0) /* why? */
3299 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3300 for (i = 0; i < pi->num_cmds; i++) {
3301 command = &pi->cmds[i];
3302 debug_printf_clean(" command %d:\n", i);
3303 if (command->argv) {
3304 for (a = 0, p = command->argv; *p; a++, p++) {
3305 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3307 free_strings(command->argv);
3308 command->argv = NULL;
3310 /* not "else if": on syntax error, we may have both! */
3311 if (command->group) {
3312 debug_printf_clean(" begin group (cmd_type:%d)\n",
3314 free_pipe_list(command->group);
3315 debug_printf_clean(" end group\n");
3316 command->group = NULL;
3318 /* else is crucial here.
3319 * If group != NULL, child_func is meaningless */
3320 #if ENABLE_HUSH_FUNCTIONS
3321 else if (command->child_func) {
3322 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3323 command->child_func->parent_cmd = NULL;
3327 free(command->group_as_string);
3328 command->group_as_string = NULL;
3330 for (r = command->redirects; r; r = rnext) {
3331 debug_printf_clean(" redirect %d%s",
3332 r->rd_fd, redir_table[r->rd_type].descrip);
3333 /* guard against the case >$FOO, where foo is unset or blank */
3334 if (r->rd_filename) {
3335 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3336 free(r->rd_filename);
3337 r->rd_filename = NULL;
3339 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3343 command->redirects = NULL;
3345 free(pi->cmds); /* children are an array, they get freed all at once */
3353 static void free_pipe_list(struct pipe *head)
3355 struct pipe *pi, *next;
3357 for (pi = head; pi; pi = next) {
3359 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3362 debug_printf_clean("pipe followup code %d\n", pi->followup);
3364 /*pi->next = NULL;*/
3370 static int run_list(struct pipe *pi);
3372 #define parse_stream(pstring, input, end_trigger) \
3373 parse_stream(input, end_trigger)
3375 static struct pipe *parse_stream(char **pstring,
3376 struct in_str *input,
3378 static void parse_and_run_string(const char *s);
3381 static char *find_in_path(const char *arg)
3384 const char *PATH = get_local_var_value("PATH");
3390 const char *end = strchrnul(PATH, ':');
3391 int sz = end - PATH; /* must be int! */
3395 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3397 /* We have xxx::yyyy in $PATH,
3398 * it means "use current dir" */
3401 if (access(ret, F_OK) == 0)
3414 static const struct built_in_command* find_builtin_helper(const char *name,
3415 const struct built_in_command *x,
3416 const struct built_in_command *end)
3419 if (strcmp(name, x->b_cmd) != 0) {
3423 debug_printf_exec("found builtin '%s'\n", name);
3428 static const struct built_in_command* find_builtin1(const char *name)
3430 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3432 static const struct built_in_command* find_builtin(const char *name)
3434 const struct built_in_command *x = find_builtin1(name);
3437 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3440 #if ENABLE_HUSH_FUNCTIONS
3441 static struct function **find_function_slot(const char *name)
3443 struct function **funcpp = &G.top_func;
3445 if (strcmp(name, (*funcpp)->name) == 0) {
3448 funcpp = &(*funcpp)->next;
3453 static const struct function *find_function(const char *name)
3455 const struct function *funcp = *find_function_slot(name);
3457 debug_printf_exec("found function '%s'\n", name);
3461 /* Note: takes ownership on name ptr */
3462 static struct function *new_function(char *name)
3464 struct function **funcpp = find_function_slot(name);
3465 struct function *funcp = *funcpp;
3467 if (funcp != NULL) {
3468 struct command *cmd = funcp->parent_cmd;
3469 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3471 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3473 /* Note: if !funcp->body, do not free body_as_string!
3474 * This is a special case of "-F name body" function:
3475 * body_as_string was not malloced! */
3477 free_pipe_list(funcp->body);
3479 free(funcp->body_as_string);
3483 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3484 cmd->argv[0] = funcp->name;
3485 cmd->group = funcp->body;
3487 cmd->group_as_string = funcp->body_as_string;
3491 debug_printf_exec("remembering new function '%s'\n", name);
3492 funcp = *funcpp = xzalloc(sizeof(*funcp));
3493 /*funcp->next = NULL;*/
3500 static void unset_func(const char *name)
3502 struct function **funcpp = find_function_slot(name);
3503 struct function *funcp = *funcpp;
3505 if (funcp != NULL) {
3506 debug_printf_exec("freeing function '%s'\n", funcp->name);
3507 *funcpp = funcp->next;
3508 /* funcp is unlinked now, deleting it.
3509 * Note: if !funcp->body, the function was created by
3510 * "-F name body", do not free ->body_as_string
3511 * and ->name as they were not malloced. */
3513 free_pipe_list(funcp->body);
3516 free(funcp->body_as_string);
3524 #define exec_function(to_free, funcp, argv) \
3525 exec_function(funcp, argv)
3527 static void exec_function(char ***to_free,
3528 const struct function *funcp,
3529 char **argv) NORETURN;
3530 static void exec_function(char ***to_free,
3531 const struct function *funcp,
3537 argv[0] = G.global_argv[0];
3538 G.global_argv = argv;
3542 /* On MMU, funcp->body is always non-NULL */
3543 n = run_list(funcp->body);
3547 re_execute_shell(to_free,
3548 funcp->body_as_string,
3555 static int run_function(const struct function *funcp, char **argv)
3561 save_and_replace_G_args(&sv, argv);
3563 /* "we are in function, ok to use return" */
3564 sv_flg = G.flag_return_in_progress;
3565 G.flag_return_in_progress = -1;
3566 # if ENABLE_HUSH_LOCAL
3567 G.func_nest_level++;
3570 /* On MMU, funcp->body is always non-NULL */
3573 /* Function defined by -F */
3574 parse_and_run_string(funcp->body_as_string);
3575 rc = G.last_exitcode;
3579 rc = run_list(funcp->body);
3582 # if ENABLE_HUSH_LOCAL
3584 struct variable *var;
3585 struct variable **var_pp;
3587 var_pp = &G.top_var;
3588 while ((var = *var_pp) != NULL) {
3589 if (var->func_nest_level < G.func_nest_level) {
3590 var_pp = &var->next;
3594 if (var->flg_export)
3595 bb_unsetenv(var->varstr);
3596 /* Remove from global list */
3597 *var_pp = var->next;
3603 G.func_nest_level--;
3606 G.flag_return_in_progress = sv_flg;
3608 restore_G_args(&sv, argv);
3612 #endif /* ENABLE_HUSH_FUNCTIONS */
3616 #define exec_builtin(to_free, x, argv) \
3617 exec_builtin(x, argv)
3619 #define exec_builtin(to_free, x, argv) \
3620 exec_builtin(to_free, argv)
3622 static void exec_builtin(char ***to_free,
3623 const struct built_in_command *x,
3624 char **argv) NORETURN;
3625 static void exec_builtin(char ***to_free,
3626 const struct built_in_command *x,
3630 int rcode = x->b_function(argv);
3634 /* On NOMMU, we must never block!
3635 * Example: { sleep 99 | read line; } & echo Ok
3637 re_execute_shell(to_free,
3646 static void execvp_or_die(char **argv) NORETURN;
3647 static void execvp_or_die(char **argv)
3649 debug_printf_exec("execing '%s'\n", argv[0]);
3650 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3651 execvp(argv[0], argv);
3652 bb_perror_msg("can't execute '%s'", argv[0]);
3653 _exit(127); /* bash compat */
3657 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3658 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3659 #define pseudo_exec(nommu_save, command, argv_expanded) \
3660 pseudo_exec(command, argv_expanded)
3663 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3665 * Don't exit() here. If you don't exec, use _exit instead.
3666 * The at_exit handlers apparently confuse the calling process,
3667 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3668 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3669 char **argv, int assignment_cnt,
3670 char **argv_expanded) NORETURN;
3671 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3672 char **argv, int assignment_cnt,
3673 char **argv_expanded)
3677 /* Case when we are here: ... | var=val | ... */
3678 if (!argv[assignment_cnt])
3679 _exit(EXIT_SUCCESS);
3681 new_env = expand_assignments(argv, assignment_cnt);
3683 set_vars_and_save_old(new_env);
3684 free(new_env); /* optional */
3685 /* we can also destroy set_vars_and_save_old's return value,
3688 nommu_save->new_env = new_env;
3689 nommu_save->old_vars = set_vars_and_save_old(new_env);
3691 if (argv_expanded) {
3692 argv = argv_expanded;
3694 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3696 nommu_save->argv = argv;
3700 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3701 if (strchr(argv[0], '/') != NULL)
3705 /* Check if the command matches any of the builtins.
3706 * Depending on context, this might be redundant. But it's
3707 * easier to waste a few CPU cycles than it is to figure out
3708 * if this is one of those cases.
3711 /* On NOMMU, it is more expensive to re-execute shell
3712 * just in order to run echo or test builtin.
3713 * It's better to skip it here and run corresponding
3714 * non-builtin later. */
3715 const struct built_in_command *x;
3716 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3718 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3721 #if ENABLE_HUSH_FUNCTIONS
3722 /* Check if the command matches any functions */
3724 const struct function *funcp = find_function(argv[0]);
3726 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3731 #if ENABLE_FEATURE_SH_STANDALONE
3732 /* Check if the command matches any busybox applets */
3734 int a = find_applet_by_name(argv[0]);
3736 # if BB_MMU /* see above why on NOMMU it is not allowed */
3737 if (APPLET_IS_NOEXEC(a)) {
3738 debug_printf_exec("running applet '%s'\n", argv[0]);
3739 run_applet_no_and_exit(a, argv);
3742 /* Re-exec ourselves */
3743 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3744 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3745 execv(bb_busybox_exec_path, argv);
3746 /* If they called chroot or otherwise made the binary no longer
3747 * executable, fall through */
3752 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3755 execvp_or_die(argv);
3758 /* Called after [v]fork() in run_pipe
3760 static void pseudo_exec(nommu_save_t *nommu_save,
3761 struct command *command,
3762 char **argv_expanded) NORETURN;
3763 static void pseudo_exec(nommu_save_t *nommu_save,
3764 struct command *command,
3765 char **argv_expanded)
3767 if (command->argv) {
3768 pseudo_exec_argv(nommu_save, command->argv,
3769 command->assignment_cnt, argv_expanded);
3772 if (command->group) {
3773 /* Cases when we are here:
3776 * ... | ( list ) | ...
3777 * ... | { list } | ...
3781 debug_printf_exec("pseudo_exec: run_list\n");
3782 reset_traps_to_defaults();
3783 rcode = run_list(command->group);
3784 /* OK to leak memory by not calling free_pipe_list,
3785 * since this process is about to exit */
3788 re_execute_shell(&nommu_save->argv_from_re_execing,
3789 command->group_as_string,
3796 /* Case when we are here: ... | >file */
3797 debug_printf_exec("pseudo_exec'ed null command\n");
3798 _exit(EXIT_SUCCESS);
3802 static const char *get_cmdtext(struct pipe *pi)
3808 /* This is subtle. ->cmdtext is created only on first backgrounding.
3809 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3810 * On subsequent bg argv is trashed, but we won't use it */
3813 argv = pi->cmds[0].argv;
3814 if (!argv || !argv[0]) {
3815 pi->cmdtext = xzalloc(1);
3821 len += strlen(*argv) + 1;
3825 argv = pi->cmds[0].argv;
3827 len = strlen(*argv);
3828 memcpy(p, *argv, len);
3836 static void insert_bg_job(struct pipe *pi)
3838 struct pipe *job, **jobp;
3841 /* Linear search for the ID of the job to use */
3843 for (job = G.job_list; job; job = job->next)
3844 if (job->jobid >= pi->jobid)
3845 pi->jobid = job->jobid + 1;
3847 /* Add job to the list of running jobs */
3849 while ((job = *jobp) != NULL)
3851 job = *jobp = xmalloc(sizeof(*job));
3853 *job = *pi; /* physical copy */
3855 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3856 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3857 for (i = 0; i < pi->num_cmds; i++) {
3858 job->cmds[i].pid = pi->cmds[i].pid;
3859 /* all other fields are not used and stay zero */
3861 job->cmdtext = xstrdup(get_cmdtext(pi));
3863 if (G_interactive_fd)
3864 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3865 /* Last command's pid goes to $! */
3866 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3867 G.last_jobid = job->jobid;
3870 static void remove_bg_job(struct pipe *pi)
3872 struct pipe *prev_pipe;
3874 if (pi == G.job_list) {
3875 G.job_list = pi->next;
3877 prev_pipe = G.job_list;
3878 while (prev_pipe->next != pi)
3879 prev_pipe = prev_pipe->next;
3880 prev_pipe->next = pi->next;
3883 G.last_jobid = G.job_list->jobid;
3888 /* Remove a backgrounded job */
3889 static void delete_finished_bg_job(struct pipe *pi)
3892 pi->stopped_cmds = 0;
3898 /* Check to see if any processes have exited -- if they
3899 * have, figure out why and see if a job has completed */
3900 static int checkjobs(struct pipe* fg_pipe)
3910 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3912 attributes = WUNTRACED;
3913 if (fg_pipe == NULL)
3914 attributes |= WNOHANG;
3917 #if ENABLE_HUSH_FAST
3918 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3919 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3920 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3921 /* There was neither fork nor SIGCHLD since last waitpid */
3922 /* Avoid doing waitpid syscall if possible */
3923 if (!G.we_have_children) {
3927 if (fg_pipe == NULL) { /* is WNOHANG set? */
3928 /* We have children, but they did not exit
3929 * or stop yet (we saw no SIGCHLD) */
3932 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3936 /* Do we do this right?
3937 * bash-3.00# sleep 20 | false
3939 * [3]+ Stopped sleep 20 | false
3940 * bash-3.00# echo $?
3941 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3942 * [hush 1.14.0: yes we do it right]
3949 #if ENABLE_HUSH_FAST
3950 i = G.count_SIGCHLD;
3952 childpid = waitpid(-1, &status, attributes);
3953 if (childpid <= 0) {
3954 if (childpid && errno != ECHILD)
3955 bb_perror_msg("waitpid");
3956 #if ENABLE_HUSH_FAST
3957 else { /* Until next SIGCHLD, waitpid's are useless */
3958 G.we_have_children = (childpid == 0);
3959 G.handled_SIGCHLD = i;
3960 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3965 dead = WIFEXITED(status) || WIFSIGNALED(status);
3968 if (WIFSTOPPED(status))
3969 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3970 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3971 if (WIFSIGNALED(status))
3972 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3973 childpid, WTERMSIG(status), WEXITSTATUS(status));
3974 if (WIFEXITED(status))
3975 debug_printf_jobs("pid %d exited, exitcode %d\n",
3976 childpid, WEXITSTATUS(status));
3978 /* Were we asked to wait for fg pipe? */
3980 for (i = 0; i < fg_pipe->num_cmds; i++) {
3981 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3982 if (fg_pipe->cmds[i].pid != childpid)
3985 fg_pipe->cmds[i].pid = 0;
3986 fg_pipe->alive_cmds--;
3987 if (i == fg_pipe->num_cmds - 1) {
3988 /* last process gives overall exitstatus */
3989 rcode = WEXITSTATUS(status);
3990 /* bash prints killer signal's name for *last*
3991 * process in pipe (prints just newline for SIGINT).
3992 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3994 if (WIFSIGNALED(status)) {
3995 int sig = WTERMSIG(status);
3996 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3997 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
3998 * Maybe we need to use sig | 128? */
4001 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
4004 fg_pipe->cmds[i].is_stopped = 1;
4005 fg_pipe->stopped_cmds++;
4007 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
4008 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
4009 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
4010 /* All processes in fg pipe have exited or stopped */
4011 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4012 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4013 * and "killall -STOP cat" */
4014 if (G_interactive_fd) {
4016 if (fg_pipe->alive_cmds)
4017 insert_bg_job(fg_pipe);
4021 if (!fg_pipe->alive_cmds)
4024 /* There are still running processes in the fg pipe */
4025 goto wait_more; /* do waitpid again */
4027 /* it wasnt fg_pipe, look for process in bg pipes */
4031 /* We asked to wait for bg or orphaned children */
4032 /* No need to remember exitcode in this case */
4033 for (pi = G.job_list; pi; pi = pi->next) {
4034 for (i = 0; i < pi->num_cmds; i++) {
4035 if (pi->cmds[i].pid == childpid)
4036 goto found_pi_and_prognum;
4039 /* Happens when shell is used as init process (init=/bin/sh) */
4040 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4041 continue; /* do waitpid again */
4043 found_pi_and_prognum:
4046 pi->cmds[i].pid = 0;
4048 if (!pi->alive_cmds) {
4049 if (G_interactive_fd)
4050 printf(JOB_STATUS_FORMAT, pi->jobid,
4051 "Done", pi->cmdtext);
4052 delete_finished_bg_job(pi);
4056 pi->cmds[i].is_stopped = 1;
4060 } /* while (waitpid succeeds)... */
4066 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4069 int rcode = checkjobs(fg_pipe);
4070 if (G_saved_tty_pgrp) {
4071 /* Job finished, move the shell to the foreground */
4072 p = getpgrp(); /* our process group id */
4073 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4074 tcsetpgrp(G_interactive_fd, p);
4080 /* Start all the jobs, but don't wait for anything to finish.
4083 * Return code is normally -1, when the caller has to wait for children
4084 * to finish to determine the exit status of the pipe. If the pipe
4085 * is a simple builtin command, however, the action is done by the
4086 * time run_pipe returns, and the exit code is provided as the
4089 * Returns -1 only if started some children. IOW: we have to
4090 * mask out retvals of builtins etc with 0xff!
4092 * The only case when we do not need to [v]fork is when the pipe
4093 * is single, non-backgrounded, non-subshell command. Examples:
4094 * cmd ; ... { list } ; ...
4095 * cmd && ... { list } && ...
4096 * cmd || ... { list } || ...
4097 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4098 * or (if SH_STANDALONE) an applet, and we can run the { list }
4099 * with run_list. If it isn't one of these, we fork and exec cmd.
4101 * Cases when we must fork:
4102 * non-single: cmd | cmd
4103 * backgrounded: cmd & { list } &
4104 * subshell: ( list ) [&]
4106 static NOINLINE int run_pipe(struct pipe *pi)
4108 static const char *const null_ptr = NULL;
4111 struct command *command;
4112 char **argv_expanded;
4115 /* it is not always needed, but we aim to smaller code */
4116 int squirrel[] = { -1, -1, -1 };
4119 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4122 IF_HUSH_JOB(pi->pgrp = -1;)
4123 pi->stopped_cmds = 0;
4124 command = &(pi->cmds[0]);
4125 argv_expanded = NULL;
4127 if (pi->num_cmds != 1
4128 || pi->followup == PIPE_BG
4129 || command->cmd_type == CMD_SUBSHELL
4136 debug_printf_exec(": group:%p argv:'%s'\n",
4137 command->group, command->argv ? command->argv[0] : "NONE");
4139 if (command->group) {
4140 #if ENABLE_HUSH_FUNCTIONS
4141 if (command->cmd_type == CMD_FUNCDEF) {
4142 /* "executing" func () { list } */
4143 struct function *funcp;
4145 funcp = new_function(command->argv[0]);
4146 /* funcp->name is already set to argv[0] */
4147 funcp->body = command->group;
4149 funcp->body_as_string = command->group_as_string;
4150 command->group_as_string = NULL;
4152 command->group = NULL;
4153 command->argv[0] = NULL;
4154 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4155 funcp->parent_cmd = command;
4156 command->child_func = funcp;
4158 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4160 return EXIT_SUCCESS;
4164 debug_printf("non-subshell group\n");
4165 rcode = 1; /* exitcode if redir failed */
4166 if (setup_redirects(command, squirrel) == 0) {
4167 debug_printf_exec(": run_list\n");
4168 rcode = run_list(command->group) & 0xff;
4170 restore_redirects(squirrel);
4171 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4173 debug_printf_exec("run_pipe: return %d\n", rcode);
4177 argv = command->argv ? command->argv : (char **) &null_ptr;
4179 const struct built_in_command *x;
4180 #if ENABLE_HUSH_FUNCTIONS
4181 const struct function *funcp;
4185 char **new_env = NULL;
4186 struct variable *old_vars = NULL;
4188 if (argv[command->assignment_cnt] == NULL) {
4189 /* Assignments, but no command */
4190 /* Ensure redirects take effect (that is, create files).
4191 * Try "a=t >file": */
4192 rcode = setup_redirects(command, squirrel);
4193 restore_redirects(squirrel);
4194 /* Set shell variables */
4196 p = expand_string_to_string(*argv);
4197 debug_printf_exec("set shell var:'%s'->'%s'\n",
4199 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4202 /* Redirect error sets $? to 1. Othervise,
4203 * if evaluating assignment value set $?, retain it.
4204 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4206 rcode = G.last_exitcode;
4207 /* Do we need to flag set_local_var() errors?
4208 * "assignment to readonly var" and "putenv error"
4210 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4212 debug_printf_exec("run_pipe: return %d\n", rcode);
4216 /* Expand the rest into (possibly) many strings each */
4218 #if ENABLE_HUSH_BASH_COMPAT
4219 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4220 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4223 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4224 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4225 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4230 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4233 /* if someone gives us an empty string: `cmd with empty output` */
4234 if (!argv_expanded[0]) {
4235 free(argv_expanded);
4237 return G.last_exitcode;
4240 x = find_builtin(argv_expanded[0]);
4241 #if ENABLE_HUSH_FUNCTIONS
4244 funcp = find_function(argv_expanded[0]);
4248 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4249 debug_printf("exec with redirects only\n");
4250 rcode = setup_redirects(command, NULL);
4251 goto clean_up_and_ret1;
4254 /* setup_redirects acts on file descriptors, not FILEs.
4255 * This is perfect for work that comes after exec().
4256 * Is it really safe for inline use? Experimentally,
4257 * things seem to work. */
4258 rcode = setup_redirects(command, squirrel);
4260 new_env = expand_assignments(argv, command->assignment_cnt);
4261 old_vars = set_vars_and_save_old(new_env);
4263 debug_printf_exec(": builtin '%s' '%s'...\n",
4264 x->b_cmd, argv_expanded[1]);
4265 rcode = x->b_function(argv_expanded) & 0xff;
4268 #if ENABLE_HUSH_FUNCTIONS
4270 # if ENABLE_HUSH_LOCAL
4271 struct variable **sv;
4272 sv = G.shadowed_vars_pp;
4273 G.shadowed_vars_pp = &old_vars;
4275 debug_printf_exec(": function '%s' '%s'...\n",
4276 funcp->name, argv_expanded[1]);
4277 rcode = run_function(funcp, argv_expanded) & 0xff;
4278 # if ENABLE_HUSH_LOCAL
4279 G.shadowed_vars_pp = sv;
4284 #if ENABLE_FEATURE_SH_STANDALONE
4287 restore_redirects(squirrel);
4288 unset_vars(new_env);
4291 free(argv_expanded);
4292 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4294 debug_printf_exec("run_pipe return %d\n", rcode);
4298 #if ENABLE_FEATURE_SH_STANDALONE
4299 i = find_applet_by_name(argv_expanded[0]);
4300 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4301 rcode = setup_redirects(command, squirrel);
4303 new_env = expand_assignments(argv, command->assignment_cnt);
4304 old_vars = set_vars_and_save_old(new_env);
4305 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4306 argv_expanded[0], argv_expanded[1]);
4307 rcode = run_nofork_applet(i, argv_expanded);
4309 goto clean_up_and_ret;
4312 /* It is neither builtin nor applet. We must fork. */
4316 /* NB: argv_expanded may already be created, and that
4317 * might include `cmd` runs! Do not rerun it! We *must*
4318 * use argv_expanded if it's non-NULL */
4320 /* Going to fork a child per each pipe member */
4324 for (i = 0; i < pi->num_cmds; i++) {
4325 struct fd_pair pipefds;
4327 volatile nommu_save_t nommu_save;
4328 nommu_save.new_env = NULL;
4329 nommu_save.old_vars = NULL;
4330 nommu_save.argv = NULL;
4331 nommu_save.argv_from_re_execing = NULL;
4333 command = &(pi->cmds[i]);
4334 if (command->argv) {
4335 debug_printf_exec(": pipe member '%s' '%s'...\n",
4336 command->argv[0], command->argv[1]);
4338 debug_printf_exec(": pipe member with no argv\n");
4341 /* pipes are inserted between pairs of commands */
4344 if ((i + 1) < pi->num_cmds)
4345 xpiped_pair(pipefds);
4347 command->pid = BB_MMU ? fork() : vfork();
4348 if (!command->pid) { /* child */
4350 disable_restore_tty_pgrp_on_exit();
4351 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4353 /* Every child adds itself to new process group
4354 * with pgid == pid_of_first_child_in_pipe */
4355 if (G.run_list_level == 1 && G_interactive_fd) {
4358 if (pgrp < 0) /* true for 1st process only */
4360 if (setpgid(0, pgrp) == 0
4361 && pi->followup != PIPE_BG
4362 && G_saved_tty_pgrp /* we have ctty */
4364 /* We do it in *every* child, not just first,
4366 tcsetpgrp(G_interactive_fd, pgrp);
4370 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4371 /* 1st cmd in backgrounded pipe
4372 * should have its stdin /dev/null'ed */
4374 if (open(bb_dev_null, O_RDONLY))
4375 xopen("/", O_RDONLY);
4377 xmove_fd(nextin, 0);
4379 xmove_fd(pipefds.wr, 1);
4382 /* Like bash, explicit redirects override pipes,
4383 * and the pipe fd is available for dup'ing. */
4384 if (setup_redirects(command, NULL))
4387 /* Restore default handlers just prior to exec */
4388 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4390 /* Stores to nommu_save list of env vars putenv'ed
4391 * (NOMMU, on MMU we don't need that) */
4392 /* cast away volatility... */
4393 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4394 /* pseudo_exec() does not return */
4397 /* parent or error */
4398 #if ENABLE_HUSH_FAST
4400 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4402 enable_restore_tty_pgrp_on_exit();
4404 /* Clean up after vforked child */
4405 free(nommu_save.argv);
4406 free(nommu_save.argv_from_re_execing);
4407 unset_vars(nommu_save.new_env);
4408 add_vars(nommu_save.old_vars);
4410 free(argv_expanded);
4411 argv_expanded = NULL;
4412 if (command->pid < 0) { /* [v]fork failed */
4413 /* Clearly indicate, was it fork or vfork */
4414 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4418 /* Second and next children need to know pid of first one */
4420 pi->pgrp = command->pid;
4426 if ((i + 1) < pi->num_cmds)
4428 /* Pass read (output) pipe end to next iteration */
4429 nextin = pipefds.rd;
4432 if (!pi->alive_cmds) {
4434 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4439 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4443 #ifndef debug_print_tree
4444 static void debug_print_tree(struct pipe *pi, int lvl)
4446 static const char *const PIPE[] = {
4452 static const char *RES[] = {
4453 [RES_NONE ] = "NONE" ,
4456 [RES_THEN ] = "THEN" ,
4457 [RES_ELIF ] = "ELIF" ,
4458 [RES_ELSE ] = "ELSE" ,
4461 # if ENABLE_HUSH_LOOPS
4462 [RES_FOR ] = "FOR" ,
4463 [RES_WHILE] = "WHILE",
4464 [RES_UNTIL] = "UNTIL",
4466 [RES_DONE ] = "DONE" ,
4468 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4471 # if ENABLE_HUSH_CASE
4472 [RES_CASE ] = "CASE" ,
4473 [RES_CASE_IN ] = "CASE_IN" ,
4474 [RES_MATCH] = "MATCH",
4475 [RES_CASE_BODY] = "CASE_BODY",
4476 [RES_ESAC ] = "ESAC" ,
4478 [RES_XXXX ] = "XXXX" ,
4479 [RES_SNTX ] = "SNTX" ,
4481 static const char *const CMDTYPE[] = {
4485 # if ENABLE_HUSH_FUNCTIONS
4494 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4495 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4497 while (prn < pi->num_cmds) {
4498 struct command *command = &pi->cmds[prn];
4499 char **argv = command->argv;
4501 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4503 command->assignment_cnt);
4504 if (command->group) {
4505 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4506 CMDTYPE[command->cmd_type],
4509 , " group_as_string:", command->group_as_string
4514 debug_print_tree(command->group, lvl+1);
4518 if (argv) while (*argv) {
4519 fprintf(stderr, " '%s'", *argv);
4522 fprintf(stderr, "\n");
4529 #endif /* debug_print_tree */
4531 /* NB: called by pseudo_exec, and therefore must not modify any
4532 * global data until exec/_exit (we can be a child after vfork!) */
4533 static int run_list(struct pipe *pi)
4535 #if ENABLE_HUSH_CASE
4536 char *case_word = NULL;
4538 #if ENABLE_HUSH_LOOPS
4539 struct pipe *loop_top = NULL;
4540 char **for_lcur = NULL;
4541 char **for_list = NULL;
4543 smallint last_followup;
4545 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4546 smalluint cond_code = 0;
4548 enum { cond_code = 0 };
4551 smallint rword; /* enum reserved_style */
4552 smallint last_rword; /* ditto */
4555 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4558 #if ENABLE_HUSH_LOOPS
4559 /* Check syntax for "for" */
4560 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4561 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4563 /* current word is FOR or IN (BOLD in comments below) */
4564 if (cpipe->next == NULL) {
4565 syntax_error("malformed for");
4567 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4570 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4571 if (cpipe->next->res_word == RES_DO)
4573 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4574 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4575 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4577 syntax_error("malformed for");
4579 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4585 /* Past this point, all code paths should jump to ret: label
4586 * in order to return, no direct "return" statements please.
4587 * This helps to ensure that no memory is leaked. */
4595 last_rword = RES_XXXX;
4597 last_followup = PIPE_SEQ;
4598 rcode = G.last_exitcode;
4600 /* Go through list of pipes, (maybe) executing them. */
4601 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4605 IF_HAS_KEYWORDS(rword = pi->res_word;)
4606 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4607 rword, cond_code, last_rword);
4608 #if ENABLE_HUSH_LOOPS
4609 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4610 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4612 /* start of a loop: remember where loop starts */
4617 /* Still in the same "if...", "then..." or "do..." branch? */
4618 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4619 if ((rcode == 0 && last_followup == PIPE_OR)
4620 || (rcode != 0 && last_followup == PIPE_AND)
4622 /* It is "<true> || CMD" or "<false> && CMD"
4623 * and we should not execute CMD */
4624 debug_printf_exec("skipped cmd because of || or &&\n");
4625 last_followup = pi->followup;
4629 last_followup = pi->followup;
4630 IF_HAS_KEYWORDS(last_rword = rword;)
4633 if (rword == RES_THEN) {
4634 /* if false; then ... fi has exitcode 0! */
4635 G.last_exitcode = rcode = EXIT_SUCCESS;
4636 /* "if <false> THEN cmd": skip cmd */
4640 if (rword == RES_ELSE || rword == RES_ELIF) {
4641 /* "if <true> then ... ELSE/ELIF cmd":
4642 * skip cmd and all following ones */
4647 #if ENABLE_HUSH_LOOPS
4648 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4650 /* first loop through for */
4652 static const char encoded_dollar_at[] ALIGN1 = {
4653 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4654 }; /* encoded representation of "$@" */
4655 static const char *const encoded_dollar_at_argv[] = {
4656 encoded_dollar_at, NULL
4657 }; /* argv list with one element: "$@" */
4660 vals = (char**)encoded_dollar_at_argv;
4661 if (pi->next->res_word == RES_IN) {
4662 /* if no variable values after "in" we skip "for" */
4663 if (!pi->next->cmds[0].argv) {
4664 G.last_exitcode = rcode = EXIT_SUCCESS;
4665 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4668 vals = pi->next->cmds[0].argv;
4669 } /* else: "for var; do..." -> assume "$@" list */
4670 /* create list of variable values */
4671 debug_print_strings("for_list made from", vals);
4672 for_list = expand_strvec_to_strvec(vals);
4673 for_lcur = for_list;
4674 debug_print_strings("for_list", for_list);
4677 /* "for" loop is over, clean up */
4683 /* Insert next value from for_lcur */
4684 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4685 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4688 if (rword == RES_IN) {
4689 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4691 if (rword == RES_DONE) {
4692 continue; /* "done" has no cmds too */
4695 #if ENABLE_HUSH_CASE
4696 if (rword == RES_CASE) {
4697 case_word = expand_strvec_to_string(pi->cmds->argv);
4700 if (rword == RES_MATCH) {
4703 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4705 /* all prev words didn't match, does this one match? */
4706 argv = pi->cmds->argv;
4708 char *pattern = expand_string_to_string(*argv);
4709 /* TODO: which FNM_xxx flags to use? */
4710 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4712 if (cond_code == 0) { /* match! we will execute this branch */
4713 free(case_word); /* make future "word)" stop */
4721 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4723 continue; /* not matched yet, skip this pipe */
4726 /* Just pressing <enter> in shell should check for jobs.
4727 * OTOH, in non-interactive shell this is useless
4728 * and only leads to extra job checks */
4729 if (pi->num_cmds == 0) {
4730 if (G_interactive_fd)
4731 goto check_jobs_and_continue;
4735 /* After analyzing all keywords and conditions, we decided
4736 * to execute this pipe. NB: have to do checkjobs(NULL)
4737 * after run_pipe to collect any background children,
4738 * even if list execution is to be stopped. */
4739 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4742 #if ENABLE_HUSH_LOOPS
4743 G.flag_break_continue = 0;
4745 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4747 /* We ran a builtin, function, or group.
4748 * rcode is already known
4749 * and we don't need to wait for anything. */
4750 G.last_exitcode = rcode;
4751 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4752 check_and_run_traps(0);
4753 #if ENABLE_HUSH_LOOPS
4754 /* Was it "break" or "continue"? */
4755 if (G.flag_break_continue) {
4756 smallint fbc = G.flag_break_continue;
4757 /* We might fall into outer *loop*,
4758 * don't want to break it too */
4760 G.depth_break_continue--;
4761 if (G.depth_break_continue == 0)
4762 G.flag_break_continue = 0;
4763 /* else: e.g. "continue 2" should *break* once, *then* continue */
4764 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4765 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4766 goto check_jobs_and_break;
4767 /* "continue": simulate end of loop */
4772 #if ENABLE_HUSH_FUNCTIONS
4773 if (G.flag_return_in_progress == 1) {
4774 /* same as "goto check_jobs_and_break" */
4779 } else if (pi->followup == PIPE_BG) {
4780 /* What does bash do with attempts to background builtins? */
4781 /* even bash 3.2 doesn't do that well with nested bg:
4782 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4783 * I'm NOT treating inner &'s as jobs */
4784 check_and_run_traps(0);
4786 if (G.run_list_level == 1)
4789 G.last_exitcode = rcode = EXIT_SUCCESS;
4790 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4793 if (G.run_list_level == 1 && G_interactive_fd) {
4794 /* Waits for completion, then fg's main shell */
4795 rcode = checkjobs_and_fg_shell(pi);
4796 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4797 check_and_run_traps(0);
4800 { /* This one just waits for completion */
4801 rcode = checkjobs(pi);
4802 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4803 check_and_run_traps(0);
4805 G.last_exitcode = rcode;
4809 /* Analyze how result affects subsequent commands */
4811 if (rword == RES_IF || rword == RES_ELIF)
4814 #if ENABLE_HUSH_LOOPS
4815 /* Beware of "while false; true; do ..."! */
4816 if (pi->next && pi->next->res_word == RES_DO) {
4817 if (rword == RES_WHILE) {
4819 /* "while false; do...done" - exitcode 0 */
4820 G.last_exitcode = rcode = EXIT_SUCCESS;
4821 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4822 goto check_jobs_and_break;
4825 if (rword == RES_UNTIL) {
4827 debug_printf_exec(": until expr is true: breaking\n");
4828 check_jobs_and_break:
4836 check_jobs_and_continue:
4843 #if ENABLE_HUSH_LOOPS
4848 #if ENABLE_HUSH_CASE
4852 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4856 /* Select which version we will use */
4857 static int run_and_free_list(struct pipe *pi)
4860 debug_printf_exec("run_and_free_list entered\n");
4862 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4863 rcode = run_list(pi);
4865 /* free_pipe_list has the side effect of clearing memory.
4866 * In the long run that function can be merged with run_list,
4867 * but doing that now would hobble the debugging effort. */
4869 debug_printf_exec("run_and_free_list return %d\n", rcode);
4874 static struct pipe *new_pipe(void)
4877 pi = xzalloc(sizeof(struct pipe));
4878 /*pi->followup = 0; - deliberately invalid value */
4879 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4883 /* Command (member of a pipe) is complete, or we start a new pipe
4884 * if ctx->command is NULL.
4885 * No errors possible here.
4887 static int done_command(struct parse_context *ctx)
4889 /* The command is really already in the pipe structure, so
4890 * advance the pipe counter and make a new, null command. */
4891 struct pipe *pi = ctx->pipe;
4892 struct command *command = ctx->command;
4895 if (IS_NULL_CMD(command)) {
4896 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4900 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4901 //debug_print_tree(ctx->list_head, 20);
4903 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4906 /* Only real trickiness here is that the uncommitted
4907 * command structure is not counted in pi->num_cmds. */
4908 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4909 ctx->command = command = &pi->cmds[pi->num_cmds];
4911 memset(command, 0, sizeof(*command));
4912 return pi->num_cmds; /* used only for 0/nonzero check */
4915 static void done_pipe(struct parse_context *ctx, pipe_style type)
4919 debug_printf_parse("done_pipe entered, followup %d\n", type);
4920 /* Close previous command */
4921 not_null = done_command(ctx);
4922 ctx->pipe->followup = type;
4924 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4925 ctx->ctx_inverted = 0;
4926 ctx->pipe->res_word = ctx->ctx_res_w;
4929 /* Without this check, even just <enter> on command line generates
4930 * tree of three NOPs (!). Which is harmless but annoying.
4931 * IOW: it is safe to do it unconditionally. */
4934 || ctx->ctx_res_w == RES_FI
4936 #if ENABLE_HUSH_LOOPS
4937 || ctx->ctx_res_w == RES_DONE
4938 || ctx->ctx_res_w == RES_FOR
4939 || ctx->ctx_res_w == RES_IN
4941 #if ENABLE_HUSH_CASE
4942 || ctx->ctx_res_w == RES_ESAC
4946 debug_printf_parse("done_pipe: adding new pipe: "
4947 "not_null:%d ctx->ctx_res_w:%d\n",
4948 not_null, ctx->ctx_res_w);
4950 ctx->pipe->next = new_p;
4952 /* RES_THEN, RES_DO etc are "sticky" -
4953 * they remain set for pipes inside if/while.
4954 * This is used to control execution.
4955 * RES_FOR and RES_IN are NOT sticky (needed to support
4956 * cases where variable or value happens to match a keyword):
4958 #if ENABLE_HUSH_LOOPS
4959 if (ctx->ctx_res_w == RES_FOR
4960 || ctx->ctx_res_w == RES_IN)
4961 ctx->ctx_res_w = RES_NONE;
4963 #if ENABLE_HUSH_CASE
4964 if (ctx->ctx_res_w == RES_MATCH)
4965 ctx->ctx_res_w = RES_CASE_BODY;
4966 if (ctx->ctx_res_w == RES_CASE)
4967 ctx->ctx_res_w = RES_CASE_IN;
4969 ctx->command = NULL; /* trick done_command below */
4970 /* Create the memory for command, roughly:
4971 * ctx->pipe->cmds = new struct command;
4972 * ctx->command = &ctx->pipe->cmds[0];
4975 //debug_print_tree(ctx->list_head, 10);
4977 debug_printf_parse("done_pipe return\n");
4980 static void initialize_context(struct parse_context *ctx)
4982 memset(ctx, 0, sizeof(*ctx));
4983 ctx->pipe = ctx->list_head = new_pipe();
4984 /* Create the memory for command, roughly:
4985 * ctx->pipe->cmds = new struct command;
4986 * ctx->command = &ctx->pipe->cmds[0];
4991 /* If a reserved word is found and processed, parse context is modified
4992 * and 1 is returned.
4995 struct reserved_combo {
4998 unsigned char assignment_flag;
5002 FLAG_END = (1 << RES_NONE ),
5004 FLAG_IF = (1 << RES_IF ),
5005 FLAG_THEN = (1 << RES_THEN ),
5006 FLAG_ELIF = (1 << RES_ELIF ),
5007 FLAG_ELSE = (1 << RES_ELSE ),
5008 FLAG_FI = (1 << RES_FI ),
5010 # if ENABLE_HUSH_LOOPS
5011 FLAG_FOR = (1 << RES_FOR ),
5012 FLAG_WHILE = (1 << RES_WHILE),
5013 FLAG_UNTIL = (1 << RES_UNTIL),
5014 FLAG_DO = (1 << RES_DO ),
5015 FLAG_DONE = (1 << RES_DONE ),
5016 FLAG_IN = (1 << RES_IN ),
5018 # if ENABLE_HUSH_CASE
5019 FLAG_MATCH = (1 << RES_MATCH),
5020 FLAG_ESAC = (1 << RES_ESAC ),
5022 FLAG_START = (1 << RES_XXXX ),
5025 static const struct reserved_combo* match_reserved_word(o_string *word)
5027 /* Mostly a list of accepted follow-up reserved words.
5028 * FLAG_END means we are done with the sequence, and are ready
5029 * to turn the compound list into a command.
5030 * FLAG_START means the word must start a new compound list.
5032 static const struct reserved_combo reserved_list[] = {
5034 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5035 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5036 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5037 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5038 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5039 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5041 # if ENABLE_HUSH_LOOPS
5042 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5043 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5044 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5045 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5046 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5047 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5049 # if ENABLE_HUSH_CASE
5050 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5051 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5054 const struct reserved_combo *r;
5056 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5057 if (strcmp(word->data, r->literal) == 0)
5062 /* Return 0: not a keyword, 1: keyword
5064 static int reserved_word(o_string *word, struct parse_context *ctx)
5066 # if ENABLE_HUSH_CASE
5067 static const struct reserved_combo reserved_match = {
5068 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5071 const struct reserved_combo *r;
5075 r = match_reserved_word(word);
5079 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5080 # if ENABLE_HUSH_CASE
5081 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5082 /* "case word IN ..." - IN part starts first MATCH part */
5083 r = &reserved_match;
5086 if (r->flag == 0) { /* '!' */
5087 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5088 syntax_error("! ! command");
5089 ctx->ctx_res_w = RES_SNTX;
5091 ctx->ctx_inverted = 1;
5094 if (r->flag & FLAG_START) {
5095 struct parse_context *old;
5097 old = xmalloc(sizeof(*old));
5098 debug_printf_parse("push stack %p\n", old);
5099 *old = *ctx; /* physical copy */
5100 initialize_context(ctx);
5102 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5103 syntax_error_at(word->data);
5104 ctx->ctx_res_w = RES_SNTX;
5107 /* "{...} fi" is ok. "{...} if" is not
5109 * if { echo foo; } then { echo bar; } fi */
5110 if (ctx->command->group)
5111 done_pipe(ctx, PIPE_SEQ);
5114 ctx->ctx_res_w = r->res;
5115 ctx->old_flag = r->flag;
5116 word->o_assignment = r->assignment_flag;
5118 if (ctx->old_flag & FLAG_END) {
5119 struct parse_context *old;
5121 done_pipe(ctx, PIPE_SEQ);
5122 debug_printf_parse("pop stack %p\n", ctx->stack);
5124 old->command->group = ctx->list_head;
5125 old->command->cmd_type = CMD_NORMAL;
5127 o_addstr(&old->as_string, ctx->as_string.data);
5128 o_free_unsafe(&ctx->as_string);
5129 old->command->group_as_string = xstrdup(old->as_string.data);
5130 debug_printf_parse("pop, remembering as:'%s'\n",
5131 old->command->group_as_string);
5133 *ctx = *old; /* physical copy */
5138 #endif /* HAS_KEYWORDS */
5140 /* Word is complete, look at it and update parsing context.
5141 * Normal return is 0. Syntax errors return 1.
5142 * Note: on return, word is reset, but not o_free'd!
5144 static int done_word(o_string *word, struct parse_context *ctx)
5146 struct command *command = ctx->command;
5148 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5149 if (word->length == 0 && word->o_quoted == 0) {
5150 debug_printf_parse("done_word return 0: true null, ignored\n");
5154 if (ctx->pending_redirect) {
5155 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5156 * only if run as "bash", not "sh" */
5157 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5159 * ...the word that follows the redirection operator
5160 * shall be subjected to tilde expansion, parameter expansion,
5161 * command substitution, arithmetic expansion, and quote
5162 * removal. Pathname expansion shall not be performed
5163 * on the word by a non-interactive shell; an interactive
5164 * shell may perform it, but shall do so only when
5165 * the expansion would result in one word."
5167 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5168 /* Cater for >\file case:
5169 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5170 * Same with heredocs:
5171 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5173 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5174 unbackslash(ctx->pending_redirect->rd_filename);
5175 /* Is it <<"HEREDOC"? */
5176 if (word->o_quoted) {
5177 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5180 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5181 ctx->pending_redirect = NULL;
5183 /* If this word wasn't an assignment, next ones definitely
5184 * can't be assignments. Even if they look like ones. */
5185 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5186 && word->o_assignment != WORD_IS_KEYWORD
5188 word->o_assignment = NOT_ASSIGNMENT;
5190 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5191 command->assignment_cnt++;
5192 word->o_assignment = MAYBE_ASSIGNMENT;
5196 # if ENABLE_HUSH_CASE
5197 if (ctx->ctx_dsemicolon
5198 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5200 /* already done when ctx_dsemicolon was set to 1: */
5201 /* ctx->ctx_res_w = RES_MATCH; */
5202 ctx->ctx_dsemicolon = 0;
5205 if (!command->argv /* if it's the first word... */
5206 # if ENABLE_HUSH_LOOPS
5207 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5208 && ctx->ctx_res_w != RES_IN
5210 # if ENABLE_HUSH_CASE
5211 && ctx->ctx_res_w != RES_CASE
5214 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5215 if (reserved_word(word, ctx)) {
5216 o_reset_to_empty_unquoted(word);
5217 debug_printf_parse("done_word return %d\n",
5218 (ctx->ctx_res_w == RES_SNTX));
5219 return (ctx->ctx_res_w == RES_SNTX);
5221 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5222 if (strcmp(word->data, "export") == 0
5223 # if ENABLE_HUSH_LOCAL
5224 || strcmp(word->data, "local") == 0
5227 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5230 # if ENABLE_HUSH_BASH_COMPAT
5231 if (strcmp(word->data, "[[") == 0) {
5232 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5238 if (command->group) {
5239 /* "{ echo foo; } echo bar" - bad */
5240 syntax_error_at(word->data);
5241 debug_printf_parse("done_word return 1: syntax error, "
5242 "groups and arglists don't mix\n");
5245 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5246 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5247 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5248 /* (otherwise it's known to be not empty and is already safe) */
5250 /* exclude "$@" - it can expand to no word despite "" */
5251 char *p = word->data;
5252 while (p[0] == SPECIAL_VAR_SYMBOL
5253 && (p[1] & 0x7f) == '@'
5254 && p[2] == SPECIAL_VAR_SYMBOL
5258 if (p == word->data || p[0] != '\0') {
5259 /* saw no "$@", or not only "$@" but some
5260 * real text is there too */
5261 /* insert "empty variable" reference, this makes
5262 * e.g. "", $empty"" etc to not disappear */
5263 o_addchr(word, SPECIAL_VAR_SYMBOL);
5264 o_addchr(word, SPECIAL_VAR_SYMBOL);
5267 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5268 debug_print_strings("word appended to argv", command->argv);
5271 #if ENABLE_HUSH_LOOPS
5272 if (ctx->ctx_res_w == RES_FOR) {
5274 || !is_well_formed_var_name(command->argv[0], '\0')
5276 /* bash says just "not a valid identifier" */
5277 syntax_error("not a valid identifier in for");
5280 /* Force FOR to have just one word (variable name) */
5281 /* NB: basically, this makes hush see "for v in ..."
5282 * syntax as if it is "for v; in ...". FOR and IN become
5283 * two pipe structs in parse tree. */
5284 done_pipe(ctx, PIPE_SEQ);
5287 #if ENABLE_HUSH_CASE
5288 /* Force CASE to have just one word */
5289 if (ctx->ctx_res_w == RES_CASE) {
5290 done_pipe(ctx, PIPE_SEQ);
5294 o_reset_to_empty_unquoted(word);
5296 debug_printf_parse("done_word return 0\n");
5301 /* Peek ahead in the input to find out if we have a "&n" construct,
5302 * as in "2>&1", that represents duplicating a file descriptor.
5304 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5305 * REDIRFD_SYNTAX_ERR if syntax error,
5306 * REDIRFD_TO_FILE if no & was seen,
5307 * or the number found.
5310 #define parse_redir_right_fd(as_string, input) \
5311 parse_redir_right_fd(input)
5313 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5319 return REDIRFD_TO_FILE;
5321 ch = i_getch(input); /* get the & */
5322 nommu_addchr(as_string, ch);
5325 ch = i_getch(input);
5326 nommu_addchr(as_string, ch);
5327 return REDIRFD_CLOSE;
5331 while (ch != EOF && isdigit(ch)) {
5332 d = d*10 + (ch-'0');
5334 ch = i_getch(input);
5335 nommu_addchr(as_string, ch);
5340 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5342 bb_error_msg("ambiguous redirect");
5343 return REDIRFD_SYNTAX_ERR;
5346 /* Return code is 0 normal, 1 if a syntax error is detected
5348 static int parse_redirect(struct parse_context *ctx,
5351 struct in_str *input)
5353 struct command *command = ctx->command;
5354 struct redir_struct *redir;
5355 struct redir_struct **redirp;
5358 dup_num = REDIRFD_TO_FILE;
5359 if (style != REDIRECT_HEREDOC) {
5360 /* Check for a '>&1' type redirect */
5361 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5362 if (dup_num == REDIRFD_SYNTAX_ERR)
5365 int ch = i_peek(input);
5366 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5367 if (dup_num) { /* <<-... */
5368 ch = i_getch(input);
5369 nommu_addchr(&ctx->as_string, ch);
5374 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5375 int ch = i_peek(input);
5377 /* >|FILE redirect ("clobbering" >).
5378 * Since we do not support "set -o noclobber" yet,
5379 * >| and > are the same for now. Just eat |.
5381 ch = i_getch(input);
5382 nommu_addchr(&ctx->as_string, ch);
5386 /* Create a new redir_struct and append it to the linked list */
5387 redirp = &command->redirects;
5388 while ((redir = *redirp) != NULL) {
5389 redirp = &(redir->next);
5391 *redirp = redir = xzalloc(sizeof(*redir));
5392 /* redir->next = NULL; */
5393 /* redir->rd_filename = NULL; */
5394 redir->rd_type = style;
5395 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5397 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5398 redir_table[style].descrip);
5400 redir->rd_dup = dup_num;
5401 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5402 /* Erik had a check here that the file descriptor in question
5403 * is legit; I postpone that to "run time"
5404 * A "-" representation of "close me" shows up as a -3 here */
5405 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5406 redir->rd_fd, redir->rd_dup);
5408 /* Set ctx->pending_redirect, so we know what to do at the
5409 * end of the next parsed word. */
5410 ctx->pending_redirect = redir;
5415 /* If a redirect is immediately preceded by a number, that number is
5416 * supposed to tell which file descriptor to redirect. This routine
5417 * looks for such preceding numbers. In an ideal world this routine
5418 * needs to handle all the following classes of redirects...
5419 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5420 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5421 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5422 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5424 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5426 * ... If n is quoted, the number shall not be recognized as part of
5427 * the redirection expression. For example:
5429 * writes the character 2 into file a"
5430 * We are getting it right by setting ->o_quoted on any \<char>
5432 * A -1 return means no valid number was found,
5433 * the caller should use the appropriate default for this redirection.
5435 static int redirect_opt_num(o_string *o)
5439 if (o->data == NULL)
5441 num = bb_strtou(o->data, NULL, 10);
5442 if (errno || num < 0)
5444 o_reset_to_empty_unquoted(o);
5449 #define fetch_till_str(as_string, input, word, skip_tabs) \
5450 fetch_till_str(input, word, skip_tabs)
5452 static char *fetch_till_str(o_string *as_string,
5453 struct in_str *input,
5457 o_string heredoc = NULL_O_STRING;
5463 ch = i_getch(input);
5464 nommu_addchr(as_string, ch);
5466 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5467 heredoc.data[past_EOL] = '\0';
5468 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5469 return heredoc.data;
5472 o_addchr(&heredoc, ch);
5473 past_EOL = heredoc.length;
5476 ch = i_getch(input);
5477 nommu_addchr(as_string, ch);
5478 } while (skip_tabs && ch == '\t');
5479 } while (ch == '\n');
5482 o_free_unsafe(&heredoc);
5485 o_addchr(&heredoc, ch);
5486 nommu_addchr(as_string, ch);
5490 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5491 * and load them all. There should be exactly heredoc_cnt of them.
5493 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5495 struct pipe *pi = ctx->list_head;
5497 while (pi && heredoc_cnt) {
5499 struct command *cmd = pi->cmds;
5501 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5503 cmd->argv ? cmd->argv[0] : "NONE");
5504 for (i = 0; i < pi->num_cmds; i++) {
5505 struct redir_struct *redir = cmd->redirects;
5507 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5508 i, cmd->argv ? cmd->argv[0] : "NONE");
5510 if (redir->rd_type == REDIRECT_HEREDOC) {
5513 redir->rd_type = REDIRECT_HEREDOC2;
5514 /* redir->rd_dup is (ab)used to indicate <<- */
5515 p = fetch_till_str(&ctx->as_string, input,
5516 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5518 syntax_error("unexpected EOF in here document");
5521 free(redir->rd_filename);
5522 redir->rd_filename = p;
5525 redir = redir->next;
5532 /* Should be 0. If it isn't, it's a parse error */
5534 bb_error_msg_and_die("heredoc BUG 2");
5540 #if ENABLE_HUSH_TICK
5541 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5546 char **to_free = NULL;
5550 pid = BB_MMU ? fork() : vfork();
5552 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5554 if (pid == 0) { /* child */
5555 disable_restore_tty_pgrp_on_exit();
5556 /* Process substitution is not considered to be usual
5557 * 'command execution'.
5558 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5565 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5566 close(channel[0]); /* NB: close _first_, then move fd! */
5567 xmove_fd(channel[1], 1);
5568 /* Prevent it from trying to handle ctrl-z etc */
5569 IF_HUSH_JOB(G.run_list_level = 1;)
5570 /* Awful hack for `trap` or $(trap).
5572 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5573 * contains an example where "trap" is executed in a subshell:
5575 * save_traps=$(trap)
5577 * eval "$save_traps"
5579 * Standard does not say that "trap" in subshell shall print
5580 * parent shell's traps. It only says that its output
5581 * must have suitable form, but then, in the above example
5582 * (which is not supposed to be normative), it implies that.
5584 * bash (and probably other shell) does implement it
5585 * (traps are reset to defaults, but "trap" still shows them),
5586 * but as a result, "trap" logic is hopelessly messed up:
5589 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5590 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5591 * # true | trap <--- trap is in subshell - no output (ditto)
5592 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5593 * trap -- 'echo Ho' SIGWINCH
5594 * # echo `(trap)` <--- in subshell in subshell - output
5595 * trap -- 'echo Ho' SIGWINCH
5596 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5597 * trap -- 'echo Ho' SIGWINCH
5599 * The rules when to forget and when to not forget traps
5600 * get really complex and nonsensical.
5602 * Our solution: ONLY bare $(trap) or `trap` is special.
5604 s = skip_whitespace(s);
5605 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5607 static const char *const argv[] = { NULL, NULL };
5608 builtin_trap((char**)argv);
5609 exit(0); /* not _exit() - we need to fflush */
5612 reset_traps_to_defaults();
5613 parse_and_run_string(s);
5614 _exit(G.last_exitcode);
5616 /* We re-execute after vfork on NOMMU. This makes this script safe:
5617 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5618 * huge=`cat BIG` # was blocking here forever
5621 re_execute_shell(&to_free,
5631 # if ENABLE_HUSH_FAST
5633 //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);
5635 enable_restore_tty_pgrp_on_exit();
5640 close_on_exec_on(channel[0]);
5641 return xfdopen_for_read(channel[0]);
5644 /* Return code is exit status of the process that is run. */
5645 static int process_command_subs(o_string *dest, const char *s)
5648 struct in_str pipe_str;
5650 int status, ch, eol_cnt;
5652 fp = generate_stream_from_string(s, &pid);
5654 /* Now send results of command back into original context */
5655 setup_file_in_str(&pipe_str, fp);
5657 while ((ch = i_getch(&pipe_str)) != EOF) {
5663 o_addchr(dest, '\n');
5666 o_addQchr(dest, ch);
5669 debug_printf("done reading from `cmd` pipe, closing it\n");
5671 /* We need to extract exitcode. Test case
5672 * "true; echo `sleep 1; false` $?"
5674 safe_waitpid(pid, &status, 0);
5675 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5676 return WEXITSTATUS(status);
5678 #endif /* ENABLE_HUSH_TICK */
5680 #if !ENABLE_HUSH_FUNCTIONS
5681 #define parse_group(dest, ctx, input, ch) \
5682 parse_group(ctx, input, ch)
5684 static int parse_group(o_string *dest, struct parse_context *ctx,
5685 struct in_str *input, int ch)
5687 /* dest contains characters seen prior to ( or {.
5688 * Typically it's empty, but for function defs,
5689 * it contains function name (without '()'). */
5690 struct pipe *pipe_list;
5692 struct command *command = ctx->command;
5694 debug_printf_parse("parse_group entered\n");
5695 #if ENABLE_HUSH_FUNCTIONS
5696 if (ch == '(' && !dest->o_quoted) {
5698 if (done_word(dest, ctx))
5701 goto skip; /* (... */
5702 if (command->argv[1]) { /* word word ... (... */
5703 syntax_error_unexpected_ch('(');
5706 /* it is "word(..." or "word (..." */
5708 ch = i_getch(input);
5709 while (ch == ' ' || ch == '\t');
5711 syntax_error_unexpected_ch(ch);
5714 nommu_addchr(&ctx->as_string, ch);
5716 ch = i_getch(input);
5717 while (ch == ' ' || ch == '\t' || ch == '\n');
5719 syntax_error_unexpected_ch(ch);
5722 nommu_addchr(&ctx->as_string, ch);
5723 command->cmd_type = CMD_FUNCDEF;
5728 #if 0 /* Prevented by caller */
5729 if (command->argv /* word [word]{... */
5730 || dest->length /* word{... */
5731 || dest->o_quoted /* ""{... */
5734 debug_printf_parse("parse_group return 1: "
5735 "syntax error, groups and arglists don't mix\n");
5740 #if ENABLE_HUSH_FUNCTIONS
5746 command->cmd_type = CMD_SUBSHELL;
5748 /* bash does not allow "{echo...", requires whitespace */
5749 ch = i_getch(input);
5750 if (ch != ' ' && ch != '\t' && ch != '\n') {
5751 syntax_error_unexpected_ch(ch);
5754 nommu_addchr(&ctx->as_string, ch);
5759 char *as_string = NULL;
5761 pipe_list = parse_stream(&as_string, input, endch);
5764 o_addstr(&ctx->as_string, as_string);
5766 /* empty ()/{} or parse error? */
5767 if (!pipe_list || pipe_list == ERR_PTR) {
5768 /* parse_stream already emitted error msg */
5772 debug_printf_parse("parse_group return 1: "
5773 "parse_stream returned %p\n", pipe_list);
5776 command->group = pipe_list;
5778 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5779 command->group_as_string = as_string;
5780 debug_printf_parse("end of group, remembering as:'%s'\n",
5781 command->group_as_string);
5784 debug_printf_parse("parse_group return 0\n");
5786 /* command remains "open", available for possible redirects */
5789 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5790 /* Subroutines for copying $(...) and `...` things */
5791 static void add_till_backquote(o_string *dest, struct in_str *input);
5793 static void add_till_single_quote(o_string *dest, struct in_str *input)
5796 int ch = i_getch(input);
5798 syntax_error_unterm_ch('\'');
5799 /*xfunc_die(); - redundant */
5806 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5807 static void add_till_double_quote(o_string *dest, struct in_str *input)
5810 int ch = i_getch(input);
5812 syntax_error_unterm_ch('"');
5813 /*xfunc_die(); - redundant */
5817 if (ch == '\\') { /* \x. Copy both chars. */
5819 ch = i_getch(input);
5823 add_till_backquote(dest, input);
5827 //if (ch == '$') ...
5830 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5832 * "Within the backquoted style of command substitution, backslash
5833 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5834 * The search for the matching backquote shall be satisfied by the first
5835 * backquote found without a preceding backslash; during this search,
5836 * if a non-escaped backquote is encountered within a shell comment,
5837 * a here-document, an embedded command substitution of the $(command)
5838 * form, or a quoted string, undefined results occur. A single-quoted
5839 * or double-quoted string that begins, but does not end, within the
5840 * "`...`" sequence produces undefined results."
5842 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5844 static void add_till_backquote(o_string *dest, struct in_str *input)
5847 int ch = i_getch(input);
5849 syntax_error_unterm_ch('`');
5850 /*xfunc_die(); - redundant */
5855 /* \x. Copy both chars unless it is \` */
5856 int ch2 = i_getch(input);
5858 syntax_error_unterm_ch('`');
5859 /*xfunc_die(); - redundant */
5861 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5868 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5869 * quoting and nested ()s.
5870 * "With the $(command) style of command substitution, all characters
5871 * following the open parenthesis to the matching closing parenthesis
5872 * constitute the command. Any valid shell script can be used for command,
5873 * except a script consisting solely of redirections which produces
5874 * unspecified results."
5876 * echo $(echo '(TEST)' BEST) (TEST) BEST
5877 * echo $(echo 'TEST)' BEST) TEST) BEST
5878 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5880 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5884 int ch = i_getch(input);
5886 syntax_error_unterm_ch(')');
5887 /*xfunc_die(); - redundant */
5895 if (i_peek(input) == ')') {
5903 add_till_single_quote(dest, input);
5908 add_till_double_quote(dest, input);
5913 /* \x. Copy verbatim. Important for \(, \) */
5914 ch = i_getch(input);
5916 syntax_error_unterm_ch(')');
5917 /*xfunc_die(); - redundant */
5924 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5926 /* Return code: 0 for OK, 1 for syntax error */
5928 #define handle_dollar(as_string, dest, input) \
5929 handle_dollar(dest, input)
5931 static int handle_dollar(o_string *as_string,
5933 struct in_str *input)
5935 int ch = i_peek(input); /* first character after the $ */
5936 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5938 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5940 ch = i_getch(input);
5941 nommu_addchr(as_string, ch);
5943 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5945 debug_printf_parse(": '%c'\n", ch);
5946 o_addchr(dest, ch | quote_mask);
5949 if (!isalnum(ch) && ch != '_')
5951 ch = i_getch(input);
5952 nommu_addchr(as_string, ch);
5954 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5955 } else if (isdigit(ch)) {
5957 ch = i_getch(input);
5958 nommu_addchr(as_string, ch);
5959 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5960 debug_printf_parse(": '%c'\n", ch);
5961 o_addchr(dest, ch | quote_mask);
5962 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5963 } else switch (ch) {
5965 case '!': /* last bg pid */
5966 case '?': /* last exit code */
5967 case '#': /* number of args */
5968 case '*': /* args */
5969 case '@': /* args */
5970 goto make_one_char_var;
5972 bool first_char, all_digits;
5973 bool in_expansion_param;
5975 ch = i_getch(input);
5976 nommu_addchr(as_string, ch);
5977 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5979 // TODO: need to handle "a=ab}; echo ${a%\}}"
5980 // and "a=abc; c=c; echo ${a%${c}}"
5981 in_expansion_param = false;
5985 ch = i_getch(input);
5986 nommu_addchr(as_string, ch);
5993 /* ${#var}: length of var contents */
6000 /* They're being verbose and doing ${?} */
6001 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
6005 if (!in_expansion_param
6006 && ( (all_digits && !isdigit(ch)) /* met non-digit: 123w */
6007 || (!all_digits && !isalnum(ch) && ch != '_') /* met non-name char: abc% */
6010 /* handle parameter expansions
6011 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6013 if (first_char /* bad (empty var name): "${%..." */
6014 || !strchr("%#:-=+?", ch) /* bad: "${var<bad_char>..." */
6016 syntax_error_unterm_str("${name}");
6017 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
6020 in_expansion_param = true;
6023 debug_printf_parse(": '%c'\n", ch);
6024 o_addchr(dest, ch | quote_mask);
6028 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6031 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6036 ch = i_getch(input);
6037 nommu_addchr(as_string, ch);
6038 # if ENABLE_SH_MATH_SUPPORT
6039 if (i_peek(input) == '(') {
6040 ch = i_getch(input);
6041 nommu_addchr(as_string, ch);
6042 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6043 o_addchr(dest, /*quote_mask |*/ '+');
6047 add_till_closing_paren(dest, input, true);
6050 o_addstr(as_string, dest->data + pos);
6051 o_addchr(as_string, ')');
6052 o_addchr(as_string, ')');
6055 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6059 # if ENABLE_HUSH_TICK
6060 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6061 o_addchr(dest, quote_mask | '`');
6065 add_till_closing_paren(dest, input, false);
6068 o_addstr(as_string, dest->data + pos);
6069 o_addchr(as_string, ')');
6072 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6078 ch = i_getch(input);
6079 nommu_addchr(as_string, ch);
6081 if (isalnum(ch)) { /* it's $_name or $_123 */
6086 /* TODO: $_ and $-: */
6087 /* $_ Shell or shell script name; or last argument of last command
6088 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6089 * but in command's env, set to full pathname used to invoke it */
6090 /* $- Option flags set by set builtin or shell options (-i etc) */
6092 o_addQchr(dest, '$');
6094 debug_printf_parse("handle_dollar return 0\n");
6099 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6100 parse_stream_dquoted(dest, input, dquote_end)
6102 static int parse_stream_dquoted(o_string *as_string,
6104 struct in_str *input,
6111 ch = i_getch(input);
6113 nommu_addchr(as_string, ch);
6114 if (ch == dquote_end) { /* may be only '"' or EOF */
6115 if (dest->o_assignment == NOT_ASSIGNMENT)
6116 dest->o_escape ^= 1;
6117 debug_printf_parse("parse_stream_dquoted return 0\n");
6120 /* note: can't move it above ch == dquote_end check! */
6122 syntax_error_unterm_ch('"');
6123 /*xfunc_die(); - redundant */
6127 next = i_peek(input);
6129 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6130 ch, ch, dest->o_escape);
6133 syntax_error("\\<eof>");
6137 * "The backslash retains its special meaning [in "..."]
6138 * only when followed by one of the following characters:
6139 * $, `, ", \, or <newline>. A double quote may be quoted
6140 * within double quotes by preceding it with a backslash."
6142 if (strchr("$`\"\\\n", next) != NULL) {
6143 ch = i_getch(input);
6145 o_addqchr(dest, ch);
6146 nommu_addchr(as_string, ch);
6149 o_addqchr(dest, '\\');
6150 nommu_addchr(as_string, '\\');
6155 if (handle_dollar(as_string, dest, input) != 0) {
6156 debug_printf_parse("parse_stream_dquoted return 1: "
6157 "handle_dollar returned non-0\n");
6162 #if ENABLE_HUSH_TICK
6164 //int pos = dest->length;
6165 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6166 o_addchr(dest, 0x80 | '`');
6167 add_till_backquote(dest, input);
6168 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6169 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6173 o_addQchr(dest, ch);
6175 && (dest->o_assignment == MAYBE_ASSIGNMENT
6176 || dest->o_assignment == WORD_IS_KEYWORD)
6177 && is_well_formed_var_name(dest->data, '=')
6179 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6185 * Scan input until EOF or end_trigger char.
6186 * Return a list of pipes to execute, or NULL on EOF
6187 * or if end_trigger character is met.
6188 * On syntax error, exit is shell is not interactive,
6189 * reset parsing machinery and start parsing anew,
6190 * or return ERR_PTR.
6192 static struct pipe *parse_stream(char **pstring,
6193 struct in_str *input,
6196 struct parse_context ctx;
6197 o_string dest = NULL_O_STRING;
6201 /* Double-quote state is handled in the state variable is_in_dquote.
6202 * A single-quote triggers a bypass of the main loop until its mate is
6203 * found. When recursing, quote state is passed in via dest->o_escape.
6205 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6206 end_trigger ? end_trigger : 'X');
6209 /* If very first arg is "" or '', dest.data may end up NULL.
6210 * Preventing this: */
6211 o_addchr(&dest, '\0');
6214 G.ifs = get_local_var_value("IFS");
6219 #if ENABLE_HUSH_INTERACTIVE
6220 input->promptmode = 0; /* PS1 */
6222 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6223 initialize_context(&ctx);
6228 const char *is_special;
6232 redir_type redir_style;
6235 /* dest.o_quoted = 1; - already is (see below) */
6236 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6239 /* We reached closing '"' */
6242 ch = i_getch(input);
6243 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6244 ch, ch, dest.o_escape);
6249 syntax_error_unterm_str("here document");
6252 /* end_trigger == '}' case errors out earlier,
6253 * checking only ')' */
6254 if (end_trigger == ')') {
6255 syntax_error_unterm_ch('('); /* exits */
6256 /* goto parse_error; */
6259 if (done_word(&dest, &ctx)) {
6263 done_pipe(&ctx, PIPE_SEQ);
6265 /* If we got nothing... */
6266 /* (this makes bare "&" cmd a no-op.
6267 * bash says: "syntax error near unexpected token '&'") */
6268 if (pi->num_cmds == 0
6269 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6275 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6277 *pstring = ctx.as_string.data;
6279 o_free_unsafe(&ctx.as_string);
6282 debug_printf_parse("parse_stream return %p\n", pi);
6285 nommu_addchr(&ctx.as_string, ch);
6289 next = i_peek(input);
6291 is_special = "{}<>;&|()#'" /* special outside of "str" */
6292 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6293 /* Are { and } special here? */
6294 if (ctx.command->argv /* word [word]{... - non-special */
6295 || dest.length /* word{... - non-special */
6296 || dest.o_quoted /* ""{... - non-special */
6297 || (next != ';' /* }; - special */
6298 && next != ')' /* }) - special */
6299 && next != '&' /* }& and }&& ... - special */
6300 && next != '|' /* }|| ... - special */
6301 && !strchr(G.ifs, next) /* {word - non-special */
6304 /* They are not special, skip "{}" */
6307 is_special = strchr(is_special, ch);
6308 is_ifs = strchr(G.ifs, ch);
6310 if (!is_special && !is_ifs) { /* ordinary char */
6312 o_addQchr(&dest, ch);
6313 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6314 || dest.o_assignment == WORD_IS_KEYWORD)
6316 && is_well_formed_var_name(dest.data, '=')
6318 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6324 if (done_word(&dest, &ctx)) {
6328 #if ENABLE_HUSH_CASE
6329 /* "case ... in <newline> word) ..." -
6330 * newlines are ignored (but ';' wouldn't be) */
6331 if (ctx.command->argv == NULL
6332 && ctx.ctx_res_w == RES_MATCH
6337 /* Treat newline as a command separator. */
6338 done_pipe(&ctx, PIPE_SEQ);
6339 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6341 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6346 dest.o_assignment = MAYBE_ASSIGNMENT;
6348 /* note: if (is_ifs) continue;
6349 * will still trigger for us */
6353 /* "cmd}" or "cmd }..." without semicolon or &:
6354 * } is an ordinary char in this case, even inside { cmd; }
6355 * Pathological example: { ""}; } should exec "}" cmd
6358 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6359 || dest.length != 0 /* word} */
6360 || dest.o_quoted /* ""} */
6364 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6365 goto skip_end_trigger;
6366 /* else: } does terminate a group */
6369 if (end_trigger && end_trigger == ch
6370 && (ch != ';' || heredoc_cnt == 0)
6371 #if ENABLE_HUSH_CASE
6373 || ctx.ctx_res_w != RES_MATCH
6374 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6379 /* This is technically valid:
6380 * { cat <<HERE; }; echo Ok
6384 * but we don't support this.
6385 * We require heredoc to be in enclosing {}/(),
6388 syntax_error_unterm_str("here document");
6391 if (done_word(&dest, &ctx)) {
6394 done_pipe(&ctx, PIPE_SEQ);
6395 dest.o_assignment = MAYBE_ASSIGNMENT;
6396 /* Do we sit outside of any if's, loops or case's? */
6398 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6402 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6404 *pstring = ctx.as_string.data;
6406 o_free_unsafe(&ctx.as_string);
6409 debug_printf_parse("parse_stream return %p: "
6410 "end_trigger char found\n",
6412 return ctx.list_head;
6419 /* Catch <, > before deciding whether this word is
6420 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6423 redir_fd = redirect_opt_num(&dest);
6424 if (done_word(&dest, &ctx)) {
6427 redir_style = REDIRECT_OVERWRITE;
6429 redir_style = REDIRECT_APPEND;
6430 ch = i_getch(input);
6431 nommu_addchr(&ctx.as_string, ch);
6434 else if (next == '(') {
6435 syntax_error(">(process) not supported");
6439 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6441 continue; /* back to top of while (1) */
6443 redir_fd = redirect_opt_num(&dest);
6444 if (done_word(&dest, &ctx)) {
6447 redir_style = REDIRECT_INPUT;
6449 redir_style = REDIRECT_HEREDOC;
6451 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6452 ch = i_getch(input);
6453 nommu_addchr(&ctx.as_string, ch);
6454 } else if (next == '>') {
6455 redir_style = REDIRECT_IO;
6456 ch = i_getch(input);
6457 nommu_addchr(&ctx.as_string, ch);
6460 else if (next == '(') {
6461 syntax_error("<(process) not supported");
6465 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6467 continue; /* back to top of while (1) */
6470 if (dest.o_assignment == MAYBE_ASSIGNMENT
6471 /* check that we are not in word in "a=1 2>word b=1": */
6472 && !ctx.pending_redirect
6474 /* ch is a special char and thus this word
6475 * cannot be an assignment */
6476 dest.o_assignment = NOT_ASSIGNMENT;
6479 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6483 if (dest.length == 0) {
6486 if (ch == EOF || ch == '\n')
6489 /* note: we do not add it to &ctx.as_string */
6491 nommu_addchr(&ctx.as_string, '\n');
6493 o_addQchr(&dest, ch);
6498 syntax_error("\\<eof>");
6501 ch = i_getch(input);
6503 o_addchr(&dest, '\\');
6504 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6505 o_addchr(&dest, ch);
6506 nommu_addchr(&ctx.as_string, ch);
6507 /* Example: echo Hello \2>file
6508 * we need to know that word 2 is quoted */
6513 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6514 ctx.as_string.data[--ctx.as_string.length] = '\0';
6519 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6520 debug_printf_parse("parse_stream parse error: "
6521 "handle_dollar returned non-0\n");
6528 ch = i_getch(input);
6530 syntax_error_unterm_ch('\'');
6531 /*xfunc_die(); - redundant */
6533 nommu_addchr(&ctx.as_string, ch);
6536 o_addqchr(&dest, ch);
6541 is_in_dquote ^= 1; /* invert */
6542 if (dest.o_assignment == NOT_ASSIGNMENT)
6545 #if ENABLE_HUSH_TICK
6550 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6551 o_addchr(&dest, '`');
6555 add_till_backquote(&dest, input);
6557 o_addstr(&ctx.as_string, dest.data + pos);
6558 o_addchr(&ctx.as_string, '`');
6560 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6561 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6566 #if ENABLE_HUSH_CASE
6569 if (done_word(&dest, &ctx)) {
6572 done_pipe(&ctx, PIPE_SEQ);
6573 #if ENABLE_HUSH_CASE
6574 /* Eat multiple semicolons, detect
6575 * whether it means something special */
6580 ch = i_getch(input);
6581 nommu_addchr(&ctx.as_string, ch);
6582 if (ctx.ctx_res_w == RES_CASE_BODY) {
6583 ctx.ctx_dsemicolon = 1;
6584 ctx.ctx_res_w = RES_MATCH;
6590 /* We just finished a cmd. New one may start
6591 * with an assignment */
6592 dest.o_assignment = MAYBE_ASSIGNMENT;
6595 if (done_word(&dest, &ctx)) {
6599 ch = i_getch(input);
6600 nommu_addchr(&ctx.as_string, ch);
6601 done_pipe(&ctx, PIPE_AND);
6603 done_pipe(&ctx, PIPE_BG);
6607 if (done_word(&dest, &ctx)) {
6610 #if ENABLE_HUSH_CASE
6611 if (ctx.ctx_res_w == RES_MATCH)
6612 break; /* we are in case's "word | word)" */
6614 if (next == '|') { /* || */
6615 ch = i_getch(input);
6616 nommu_addchr(&ctx.as_string, ch);
6617 done_pipe(&ctx, PIPE_OR);
6619 /* we could pick up a file descriptor choice here
6620 * with redirect_opt_num(), but bash doesn't do it.
6621 * "echo foo 2| cat" yields "foo 2". */
6624 o_reset_to_empty_unquoted(&ctx.as_string);
6629 #if ENABLE_HUSH_CASE
6630 /* "case... in [(]word)..." - skip '(' */
6631 if (ctx.ctx_res_w == RES_MATCH
6632 && ctx.command->argv == NULL /* not (word|(... */
6633 && dest.length == 0 /* not word(... */
6634 && dest.o_quoted == 0 /* not ""(... */
6640 if (parse_group(&dest, &ctx, input, ch) != 0) {
6645 #if ENABLE_HUSH_CASE
6646 if (ctx.ctx_res_w == RES_MATCH)
6650 /* proper use of this character is caught by end_trigger:
6651 * if we see {, we call parse_group(..., end_trigger='}')
6652 * and it will match } earlier (not here). */
6653 syntax_error_unexpected_ch(ch);
6657 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6663 struct parse_context *pctx;
6664 IF_HAS_KEYWORDS(struct parse_context *p2;)
6666 /* Clean up allocated tree.
6667 * Sample for finding leaks on syntax error recovery path.
6668 * Run it from interactive shell, watch pmap `pidof hush`.
6669 * while if false; then false; fi; do break; fi
6670 * Samples to catch leaks at execution:
6671 * while if (true | {true;}); then echo ok; fi; do break; done
6672 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6676 /* Update pipe/command counts,
6677 * otherwise freeing may miss some */
6678 done_pipe(pctx, PIPE_SEQ);
6679 debug_printf_clean("freeing list %p from ctx %p\n",
6680 pctx->list_head, pctx);
6681 debug_print_tree(pctx->list_head, 0);
6682 free_pipe_list(pctx->list_head);
6683 debug_printf_clean("freed list %p\n", pctx->list_head);
6685 o_free_unsafe(&pctx->as_string);
6687 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6691 IF_HAS_KEYWORDS(pctx = p2;)
6692 } while (HAS_KEYWORDS && pctx);
6693 /* Free text, clear all dest fields */
6695 /* If we are not in top-level parse, we return,
6696 * our caller will propagate error.
6698 if (end_trigger != ';') {
6706 /* Discard cached input, force prompt */
6708 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6713 /* Executing from string: eval, sh -c '...'
6714 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6715 * end_trigger controls how often we stop parsing
6716 * NUL: parse all, execute, return
6717 * ';': parse till ';' or newline, execute, repeat till EOF
6719 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6721 /* Why we need empty flag?
6722 * An obscure corner case "false; ``; echo $?":
6723 * empty command in `` should still set $? to 0.
6724 * But we can't just set $? to 0 at the start,
6725 * this breaks "false; echo `echo $?`" case.
6729 struct pipe *pipe_list;
6731 pipe_list = parse_stream(NULL, inp, end_trigger);
6732 if (!pipe_list) { /* EOF */
6734 G.last_exitcode = 0;
6737 debug_print_tree(pipe_list, 0);
6738 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6739 run_and_free_list(pipe_list);
6744 static void parse_and_run_string(const char *s)
6746 struct in_str input;
6747 setup_string_in_str(&input, s);
6748 parse_and_run_stream(&input, '\0');
6751 static void parse_and_run_file(FILE *f)
6753 struct in_str input;
6754 setup_file_in_str(&input, f);
6755 parse_and_run_stream(&input, ';');
6758 /* Called a few times only (or even once if "sh -c") */
6759 static void init_sigmasks(void)
6763 sigset_t old_blocked_set;
6765 if (!G.inherited_set_is_saved) {
6766 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6767 G.inherited_set = G.blocked_set;
6769 old_blocked_set = G.blocked_set;
6771 mask = (1 << SIGQUIT);
6772 if (G_interactive_fd) {
6773 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6774 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6775 mask |= SPECIAL_JOB_SIGS;
6777 G.non_DFL_mask = mask;
6782 sigaddset(&G.blocked_set, sig);
6786 sigdelset(&G.blocked_set, SIGCHLD);
6788 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6789 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6791 /* POSIX allows shell to re-enable SIGCHLD
6792 * even if it was SIG_IGN on entry */
6793 #if ENABLE_HUSH_FAST
6794 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6795 if (!G.inherited_set_is_saved)
6796 signal(SIGCHLD, SIGCHLD_handler);
6798 if (!G.inherited_set_is_saved)
6799 signal(SIGCHLD, SIG_DFL);
6802 G.inherited_set_is_saved = 1;
6807 static void maybe_set_to_sigexit(int sig)
6809 void (*handler)(int);
6810 /* non_DFL_mask'ed signals are, well, masked,
6811 * no need to set handler for them.
6813 if (!((G.non_DFL_mask >> sig) & 1)) {
6814 handler = signal(sig, sigexit);
6815 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6816 signal(sig, handler);
6819 /* Set handlers to restore tty pgrp and exit */
6820 static void set_fatal_handlers(void)
6822 /* We _must_ restore tty pgrp on fatal signals */
6824 maybe_set_to_sigexit(SIGILL );
6825 maybe_set_to_sigexit(SIGFPE );
6826 maybe_set_to_sigexit(SIGBUS );
6827 maybe_set_to_sigexit(SIGSEGV);
6828 maybe_set_to_sigexit(SIGTRAP);
6829 } /* else: hush is perfect. what SEGV? */
6830 maybe_set_to_sigexit(SIGABRT);
6831 /* bash 3.2 seems to handle these just like 'fatal' ones */
6832 maybe_set_to_sigexit(SIGPIPE);
6833 maybe_set_to_sigexit(SIGALRM);
6834 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6835 * if we aren't interactive... but in this case
6836 * we never want to restore pgrp on exit, and this fn is not called */
6837 /*maybe_set_to_sigexit(SIGHUP );*/
6838 /*maybe_set_to_sigexit(SIGTERM);*/
6839 /*maybe_set_to_sigexit(SIGINT );*/
6843 static int set_mode(const char cstate, const char mode)
6845 int state = (cstate == '-' ? 1 : 0);
6847 case 'n': G.fake_mode = state; break;
6848 case 'x': /*G.debug_mode = state;*/ break;
6849 default: return EXIT_FAILURE;
6851 return EXIT_SUCCESS;
6854 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6855 int hush_main(int argc, char **argv)
6857 static const struct variable const_shell_ver = {
6859 .varstr = (char*)hush_version_str,
6860 .max_len = 1, /* 0 can provoke free(name) */
6865 unsigned builtin_argc;
6867 struct variable *cur_var;
6870 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6871 G.last_exitcode = EXIT_SUCCESS;
6873 G.argv0_for_re_execing = argv[0];
6875 /* Deal with HUSH_VERSION */
6876 G.shell_ver = const_shell_ver; /* copying struct here */
6877 G.top_var = &G.shell_ver;
6878 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6879 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6880 /* Initialize our shell local variables with the values
6881 * currently living in the environment */
6882 cur_var = G.top_var;
6885 char *value = strchr(*e, '=');
6886 if (value) { /* paranoia */
6887 cur_var->next = xzalloc(sizeof(*cur_var));
6888 cur_var = cur_var->next;
6889 cur_var->varstr = *e;
6890 cur_var->max_len = strlen(*e);
6891 cur_var->flg_export = 1;
6895 /* reinstate HUSH_VERSION */
6896 debug_printf_env("putenv '%s'\n", hush_version_str);
6897 putenv((char *)hush_version_str);
6900 set_pwd_var(/*exp:*/ 1);
6901 /* bash also exports SHLVL and _,
6902 * and sets (but doesn't export) the following variables:
6904 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6905 * BASH_VERSION='3.2.0(1)-release'
6907 * MACHTYPE=i386-pc-linux-gnu
6909 * HOSTNAME=<xxxxxxxxxx>
6910 * PPID=<NNNNN> - we also do it elsewhere
6921 * PIPESTATUS=([0]="0")
6922 * HISTFILE=/<xxx>/.bash_history
6926 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6928 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6938 #if ENABLE_FEATURE_EDITING
6939 G.line_input_state = new_line_input_t(FOR_SHELL);
6941 G.global_argc = argc;
6942 G.global_argv = argv;
6943 /* Initialize some more globals to non-zero values */
6944 cmdedit_update_prompt();
6946 if (setjmp(die_jmp)) {
6947 /* xfunc has failed! die die die */
6948 /* no EXIT traps, this is an escape hatch! */
6950 hush_exit(xfunc_error_retval);
6953 /* Shell is non-interactive at first. We need to call
6954 * init_sigmasks() if we are going to execute "sh <script>",
6955 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6956 * If we later decide that we are interactive, we run init_sigmasks()
6957 * in order to intercept (more) signals.
6961 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6964 opt = getopt(argc, argv, "+c:xins"
6967 # if ENABLE_HUSH_FUNCTIONS
6977 * sh ... -c 'script'
6978 * sh ... -c 'script' ARG0 [ARG1...]
6979 * On NOMMU, if builtin_argc != 0,
6980 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
6981 * "" needs to be replaced with NULL
6982 * and BARGV vector fed to builtin function.
6983 * Note: the form without ARG0 never happens:
6984 * sh ... -c 'builtin' BARGV... ""
6987 G.root_pid = getpid();
6988 G.root_ppid = getppid();
6990 G.global_argv = argv + optind;
6991 G.global_argc = argc - optind;
6993 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6994 const struct built_in_command *x;
6997 x = find_builtin(optarg);
6998 if (x) { /* paranoia */
6999 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7000 G.global_argv += builtin_argc;
7001 G.global_argv[-1] = NULL; /* replace "" */
7002 G.last_exitcode = x->b_function(argv + optind - 1);
7006 if (!G.global_argv[0]) {
7007 /* -c 'script' (no params): prevent empty $0 */
7008 G.global_argv--; /* points to argv[i] of 'script' */
7009 G.global_argv[0] = argv[0];
7011 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7013 parse_and_run_string(optarg);
7016 /* Well, we cannot just declare interactiveness,
7017 * we have to have some stuff (ctty, etc) */
7018 /* G_interactive_fd++; */
7021 /* "-s" means "read from stdin", but this is how we always
7022 * operate, so simply do nothing here. */
7025 case '<': /* "big heredoc" support */
7026 full_write(STDOUT_FILENO, optarg, strlen(optarg));
7029 unsigned long long empty_trap_mask;
7031 G.root_pid = bb_strtou(optarg, &optarg, 16);
7033 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7035 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7037 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7039 builtin_argc = bb_strtou(optarg, &optarg, 16);
7041 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7042 if (empty_trap_mask != 0) {
7045 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7046 for (sig = 1; sig < NSIG; sig++) {
7047 if (empty_trap_mask & (1LL << sig)) {
7048 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7049 sigaddset(&G.blocked_set, sig);
7052 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7054 # if ENABLE_HUSH_LOOPS
7056 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7062 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7064 # if ENABLE_HUSH_FUNCTIONS
7066 struct function *funcp = new_function(optarg);
7067 /* funcp->name is already set to optarg */
7068 /* funcp->body is set to NULL. It's a special case. */
7069 funcp->body_as_string = argv[optind];
7077 if (!set_mode('-', opt))
7081 fprintf(stderr, "Usage: sh [FILE]...\n"
7082 " or: sh -c command [args]...\n\n");
7088 } /* option parsing loop */
7091 G.root_pid = getpid();
7092 G.root_ppid = getppid();
7095 /* If we are login shell... */
7096 if (argv[0] && argv[0][0] == '-') {
7098 debug_printf("sourcing /etc/profile\n");
7099 input = fopen_for_read("/etc/profile");
7100 if (input != NULL) {
7101 close_on_exec_on(fileno(input));
7103 parse_and_run_file(input);
7106 /* bash: after sourcing /etc/profile,
7107 * tries to source (in the given order):
7108 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7109 * stopping on first found. --noprofile turns this off.
7110 * bash also sources ~/.bash_logout on exit.
7111 * If called as sh, skips .bash_XXX files.
7118 * "bash <script>" (which is never interactive (unless -i?))
7119 * sources $BASH_ENV here (without scanning $PATH).
7120 * If called as sh, does the same but with $ENV.
7122 debug_printf("running script '%s'\n", argv[optind]);
7123 G.global_argv = argv + optind;
7124 G.global_argc = argc - optind;
7125 input = xfopen_for_read(argv[optind]);
7126 close_on_exec_on(fileno(input));
7128 parse_and_run_file(input);
7129 #if ENABLE_FEATURE_CLEAN_UP
7135 /* Up to here, shell was non-interactive. Now it may become one.
7136 * NB: don't forget to (re)run init_sigmasks() as needed.
7139 /* A shell is interactive if the '-i' flag was given,
7140 * or if all of the following conditions are met:
7142 * no arguments remaining or the -s flag given
7143 * standard input is a terminal
7144 * standard output is a terminal
7145 * Refer to Posix.2, the description of the 'sh' utility.
7148 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7149 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7150 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7151 if (G_saved_tty_pgrp < 0)
7152 G_saved_tty_pgrp = 0;
7154 /* try to dup stdin to high fd#, >= 255 */
7155 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7156 if (G_interactive_fd < 0) {
7157 /* try to dup to any fd */
7158 G_interactive_fd = dup(STDIN_FILENO);
7159 if (G_interactive_fd < 0) {
7161 G_interactive_fd = 0;
7162 G_saved_tty_pgrp = 0;
7165 // TODO: track & disallow any attempts of user
7166 // to (inadvertently) close/redirect G_interactive_fd
7168 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7169 if (G_interactive_fd) {
7170 close_on_exec_on(G_interactive_fd);
7172 if (G_saved_tty_pgrp) {
7173 /* If we were run as 'hush &', sleep until we are
7174 * in the foreground (tty pgrp == our pgrp).
7175 * If we get started under a job aware app (like bash),
7176 * make sure we are now in charge so we don't fight over
7177 * who gets the foreground */
7179 pid_t shell_pgrp = getpgrp();
7180 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7181 if (G_saved_tty_pgrp == shell_pgrp)
7183 /* send TTIN to ourself (should stop us) */
7184 kill(- shell_pgrp, SIGTTIN);
7188 /* Block some signals */
7191 if (G_saved_tty_pgrp) {
7192 /* Set other signals to restore saved_tty_pgrp */
7193 set_fatal_handlers();
7194 /* Put ourselves in our own process group
7195 * (bash, too, does this only if ctty is available) */
7196 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7197 /* Grab control of the terminal */
7198 tcsetpgrp(G_interactive_fd, getpid());
7200 /* -1 is special - makes xfuncs longjmp, not exit
7201 * (we reset die_sleep = 0 whereever we [v]fork) */
7202 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7206 #elif ENABLE_HUSH_INTERACTIVE
7207 /* No job control compiled in, only prompt/line editing */
7208 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7209 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7210 if (G_interactive_fd < 0) {
7211 /* try to dup to any fd */
7212 G_interactive_fd = dup(STDIN_FILENO);
7213 if (G_interactive_fd < 0)
7215 G_interactive_fd = 0;
7218 if (G_interactive_fd) {
7219 close_on_exec_on(G_interactive_fd);
7223 /* We have interactiveness code disabled */
7227 * if interactive but not a login shell, sources ~/.bashrc
7228 * (--norc turns this off, --rcfile <file> overrides)
7231 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7232 /* note: ash and hush share this string */
7233 printf("\n\n%s %s\n"
7234 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7237 "hush - the humble shell"
7241 parse_and_run_file(stdin);
7244 #if ENABLE_FEATURE_CLEAN_UP
7245 if (G.cwd != bb_msg_unknown)
7247 cur_var = G.top_var->next;
7249 struct variable *tmp = cur_var;
7250 if (!cur_var->max_len)
7251 free(cur_var->varstr);
7252 cur_var = cur_var->next;
7256 hush_exit(G.last_exitcode);
7261 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7262 int lash_main(int argc, char **argv)
7264 bb_error_msg("lash is deprecated, please use hush instead");
7265 return hush_main(argc, argv);
7270 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7271 int msh_main(int argc, char **argv)
7273 //bb_error_msg("msh is deprecated, please use hush instead");
7274 return hush_main(argc, argv);
7282 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7287 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7294 return applet_main_func(argc, argv - argc);
7297 static int FAST_FUNC builtin_test(char **argv)
7299 return run_applet_main(argv, test_main);
7302 static int FAST_FUNC builtin_echo(char **argv)
7304 return run_applet_main(argv, echo_main);
7308 static int FAST_FUNC builtin_printf(char **argv)
7310 return run_applet_main(argv, printf_main);
7314 static char **skip_dash_dash(char **argv)
7317 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7322 static int FAST_FUNC builtin_eval(char **argv)
7324 int rcode = EXIT_SUCCESS;
7326 argv = skip_dash_dash(argv);
7328 char *str = expand_strvec_to_string(argv);
7330 * eval "echo Hi; done" ("done" is syntax error):
7331 * "echo Hi" will not execute too.
7333 parse_and_run_string(str);
7335 rcode = G.last_exitcode;
7340 static int FAST_FUNC builtin_cd(char **argv)
7344 argv = skip_dash_dash(argv);
7346 if (newdir == NULL) {
7347 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7348 * bash says "bash: cd: HOME not set" and does nothing
7351 const char *home = get_local_var_value("HOME");
7352 newdir = home ? home : "/";
7354 if (chdir(newdir)) {
7355 /* Mimic bash message exactly */
7356 bb_perror_msg("cd: %s", newdir);
7357 return EXIT_FAILURE;
7359 /* Read current dir (get_cwd(1) is inside) and set PWD.
7360 * Note: do not enforce exporting. If PWD was unset or unexported,
7361 * set it again, but do not export. bash does the same.
7363 set_pwd_var(/*exp:*/ 0);
7364 return EXIT_SUCCESS;
7367 static int FAST_FUNC builtin_exec(char **argv)
7369 argv = skip_dash_dash(argv);
7370 if (argv[0] == NULL)
7371 return EXIT_SUCCESS; /* bash does this */
7373 /* Careful: we can end up here after [v]fork. Do not restore
7374 * tty pgrp then, only top-level shell process does that */
7375 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7376 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7378 /* TODO: if exec fails, bash does NOT exit! We do.
7379 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7380 * and tcsetpgrp, and this is inherently racy.
7382 execvp_or_die(argv);
7385 static int FAST_FUNC builtin_exit(char **argv)
7387 debug_printf_exec("%s()\n", __func__);
7389 /* interactive bash:
7390 * # trap "echo EEE" EXIT
7393 * There are stopped jobs.
7394 * (if there are _stopped_ jobs, running ones don't count)
7397 # EEE (then bash exits)
7399 * we can use G.exiting = -1 as indicator "last cmd was exit"
7402 /* note: EXIT trap is run by hush_exit */
7403 argv = skip_dash_dash(argv);
7404 if (argv[0] == NULL)
7405 hush_exit(G.last_exitcode);
7406 /* mimic bash: exit 123abc == exit 255 + error msg */
7407 xfunc_error_retval = 255;
7408 /* bash: exit -2 == exit 254, no error msg */
7409 hush_exit(xatoi(argv[0]) & 0xff);
7412 static void print_escaped(const char *s)
7417 const char *p = strchrnul(s, '\'');
7418 /* print 'xxxx', possibly just '' */
7419 printf("'%.*s'", (int)(p - s), s);
7424 /* s points to '; print "'''...'''" */
7426 do putchar('\''); while (*++s == '\'');
7431 #if !ENABLE_HUSH_LOCAL
7432 #define helper_export_local(argv, exp, lvl) \
7433 helper_export_local(argv, exp)
7435 static void helper_export_local(char **argv, int exp, int lvl)
7440 /* So far we do not check that name is valid (TODO?) */
7442 if (strchr(name, '=') == NULL) {
7443 struct variable *var;
7445 var = get_local_var(name);
7446 if (exp == -1) { /* unexporting? */
7447 /* export -n NAME (without =VALUE) */
7449 var->flg_export = 0;
7450 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7452 } /* else: export -n NOT_EXISTING_VAR: no-op */
7455 if (exp == 1) { /* exporting? */
7456 /* export NAME (without =VALUE) */
7458 var->flg_export = 1;
7459 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7460 putenv(var->varstr);
7464 /* Exporting non-existing variable.
7465 * bash does not put it in environment,
7466 * but remembers that it is exported,
7467 * and does put it in env when it is set later.
7468 * We just set it to "" and export. */
7469 /* Or, it's "local NAME" (without =VALUE).
7470 * bash sets the value to "". */
7471 name = xasprintf("%s=", name);
7473 /* (Un)exporting/making local NAME=VALUE */
7474 name = xstrdup(name);
7476 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7480 static int FAST_FUNC builtin_export(char **argv)
7482 unsigned opt_unexport;
7484 #if ENABLE_HUSH_EXPORT_N
7485 /* "!": do not abort on errors */
7486 opt_unexport = getopt32(argv, "!n");
7487 if (opt_unexport == (uint32_t)-1)
7488 return EXIT_FAILURE;
7495 if (argv[0] == NULL) {
7502 /* ash emits: export VAR='VAL'
7503 * bash: declare -x VAR="VAL"
7504 * we follow ash example */
7505 const char *s = *e++;
7506 const char *p = strchr(s, '=');
7508 if (!p) /* wtf? take next variable */
7511 printf("export %.*s", (int)(p - s) + 1, s);
7512 print_escaped(p + 1);
7516 /*fflush_all(); - done after each builtin anyway */
7518 return EXIT_SUCCESS;
7521 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7523 return EXIT_SUCCESS;
7526 #if ENABLE_HUSH_LOCAL
7527 static int FAST_FUNC builtin_local(char **argv)
7529 if (G.func_nest_level == 0) {
7530 bb_error_msg("%s: not in a function", argv[0]);
7531 return EXIT_FAILURE; /* bash compat */
7533 helper_export_local(argv, 0, G.func_nest_level);
7534 return EXIT_SUCCESS;
7538 static int FAST_FUNC builtin_trap(char **argv)
7544 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7549 /* No args: print all trapped */
7550 for (i = 0; i < NSIG; ++i) {
7553 print_escaped(G.traps[i]);
7554 /* note: bash adds "SIG", but only if invoked
7555 * as "bash". If called as "sh", or if set -o posix,
7556 * then it prints short signal names.
7557 * We are printing short names: */
7558 printf(" %s\n", get_signame(i));
7561 /*fflush_all(); - done after each builtin anyway */
7562 return EXIT_SUCCESS;
7566 /* If first arg is a number: reset all specified signals */
7567 sig = bb_strtou(*argv, NULL, 10);
7573 sig = get_signum(*argv++);
7574 if (sig < 0 || sig >= NSIG) {
7576 /* Mimic bash message exactly */
7577 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7582 G.traps[sig] = xstrdup(new_cmd);
7584 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7585 get_signame(sig), sig, G.traps[sig]);
7587 /* There is no signal for 0 (EXIT) */
7592 sigaddset(&G.blocked_set, sig);
7594 /* There was a trap handler, we are removing it
7595 * (if sig has non-DFL handling,
7596 * we don't need to do anything) */
7597 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7599 sigdelset(&G.blocked_set, sig);
7602 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7606 if (!argv[1]) { /* no second arg */
7607 bb_error_msg("trap: invalid arguments");
7608 return EXIT_FAILURE;
7611 /* First arg is "-": reset all specified to default */
7612 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7613 /* Everything else: set arg as signal handler
7614 * (includes "" case, which ignores signal) */
7615 if (argv[0][0] == '-') {
7616 if (argv[0][1] == '\0') { /* "-" */
7617 /* new_cmd remains NULL: "reset these sigs" */
7620 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7623 /* else: "-something", no special meaning */
7628 goto process_sig_list;
7631 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7632 static int FAST_FUNC builtin_type(char **argv)
7634 int ret = EXIT_SUCCESS;
7640 if (0) {} /* make conditional compile easier below */
7641 /*else if (find_alias(*argv))
7642 type = "an alias";*/
7643 #if ENABLE_HUSH_FUNCTIONS
7644 else if (find_function(*argv))
7645 type = "a function";
7647 else if (find_builtin(*argv))
7648 type = "a shell builtin";
7649 else if ((path = find_in_path(*argv)) != NULL)
7652 bb_error_msg("type: %s: not found", *argv);
7657 printf("%s is %s\n", *argv, type);
7665 /* built-in 'fg' and 'bg' handler */
7666 static int FAST_FUNC builtin_fg_bg(char **argv)
7671 if (!G_interactive_fd)
7672 return EXIT_FAILURE;
7674 /* If they gave us no args, assume they want the last backgrounded task */
7676 for (pi = G.job_list; pi; pi = pi->next) {
7677 if (pi->jobid == G.last_jobid) {
7681 bb_error_msg("%s: no current job", argv[0]);
7682 return EXIT_FAILURE;
7684 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7685 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7686 return EXIT_FAILURE;
7688 for (pi = G.job_list; pi; pi = pi->next) {
7689 if (pi->jobid == jobnum) {
7693 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7694 return EXIT_FAILURE;
7696 /* TODO: bash prints a string representation
7697 * of job being foregrounded (like "sleep 1 | cat") */
7698 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7699 /* Put the job into the foreground. */
7700 tcsetpgrp(G_interactive_fd, pi->pgrp);
7703 /* Restart the processes in the job */
7704 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7705 for (i = 0; i < pi->num_cmds; i++) {
7706 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7707 pi->cmds[i].is_stopped = 0;
7709 pi->stopped_cmds = 0;
7711 i = kill(- pi->pgrp, SIGCONT);
7713 if (errno == ESRCH) {
7714 delete_finished_bg_job(pi);
7715 return EXIT_SUCCESS;
7717 bb_perror_msg("kill (SIGCONT)");
7720 if (argv[0][0] == 'f') {
7722 return checkjobs_and_fg_shell(pi);
7724 return EXIT_SUCCESS;
7728 #if ENABLE_HUSH_HELP
7729 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7731 const struct built_in_command *x;
7734 "Built-in commands:\n"
7735 "------------------\n");
7736 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7738 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7741 return EXIT_SUCCESS;
7746 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7749 const char *status_string;
7751 for (job = G.job_list; job; job = job->next) {
7752 if (job->alive_cmds == job->stopped_cmds)
7753 status_string = "Stopped";
7755 status_string = "Running";
7757 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7759 return EXIT_SUCCESS;
7764 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7769 # ifdef M_TRIM_THRESHOLD
7770 /* Optional. Reduces probability of false positives */
7773 /* Crude attempt to find where "free memory" starts,
7774 * sans fragmentation. */
7776 l = (unsigned long)p;
7779 if (l < (unsigned long)p) l = (unsigned long)p;
7782 if (!G.memleak_value)
7783 G.memleak_value = l;
7785 l -= G.memleak_value;
7792 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7797 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7800 return EXIT_SUCCESS;
7803 static int FAST_FUNC builtin_read(char **argv)
7812 /* "!": do not abort on errors.
7813 * Option string must start with "sr" to match BUILTIN_READ_xxx
7815 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7816 if (read_flags == (uint32_t)-1)
7817 return EXIT_FAILURE;
7820 r = shell_builtin_read(set_local_var_from_halves,
7822 get_local_var_value("IFS"), /* can be NULL */
7830 if ((uintptr_t)r > 1) {
7831 bb_error_msg("%s", r);
7832 r = (char*)(uintptr_t)1;
7835 return (uintptr_t)r;
7838 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7839 * built-in 'set' handler
7841 * set [-abCefhmnuvx] [-o option] [argument...]
7842 * set [+abCefhmnuvx] [+o option] [argument...]
7843 * set -- [argument...]
7846 * Implementations shall support the options in both their hyphen and
7847 * plus-sign forms. These options can also be specified as options to sh.
7849 * Write out all variables and their values: set
7850 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7851 * Turn on the -x and -v options: set -xv
7852 * Unset all positional parameters: set --
7853 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7854 * Set the positional parameters to the expansion of x, even if x expands
7855 * with a leading '-' or '+': set -- $x
7857 * So far, we only support "set -- [argument...]" and some of the short names.
7859 static int FAST_FUNC builtin_set(char **argv)
7862 char **pp, **g_argv;
7863 char *arg = *++argv;
7867 for (e = G.top_var; e; e = e->next)
7869 return EXIT_SUCCESS;
7873 if (!strcmp(arg, "--")) {
7877 if (arg[0] != '+' && arg[0] != '-')
7879 for (n = 1; arg[n]; ++n)
7880 if (set_mode(arg[0], arg[n]))
7882 } while ((arg = *++argv) != NULL);
7883 /* Now argv[0] is 1st argument */
7886 return EXIT_SUCCESS;
7889 /* NB: G.global_argv[0] ($0) is never freed/changed */
7890 g_argv = G.global_argv;
7891 if (G.global_args_malloced) {
7897 G.global_args_malloced = 1;
7898 pp = xzalloc(sizeof(pp[0]) * 2);
7899 pp[0] = g_argv[0]; /* retain $0 */
7902 /* This realloc's G.global_argv */
7903 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7910 return EXIT_SUCCESS;
7912 /* Nothing known, so abort */
7914 bb_error_msg("set: %s: invalid option", arg);
7915 return EXIT_FAILURE;
7918 static int FAST_FUNC builtin_shift(char **argv)
7921 argv = skip_dash_dash(argv);
7925 if (n >= 0 && n < G.global_argc) {
7926 if (G.global_args_malloced) {
7929 free(G.global_argv[m++]);
7932 memmove(&G.global_argv[1], &G.global_argv[n+1],
7933 G.global_argc * sizeof(G.global_argv[0]));
7934 return EXIT_SUCCESS;
7936 return EXIT_FAILURE;
7939 static int FAST_FUNC builtin_source(char **argv)
7941 char *arg_path, *filename;
7944 #if ENABLE_HUSH_FUNCTIONS
7948 argv = skip_dash_dash(argv);
7951 /* bash says: "bash: .: filename argument required" */
7952 return 2; /* bash compat */
7955 if (!strchr(filename, '/')) {
7956 arg_path = find_in_path(filename);
7958 filename = arg_path;
7960 input = fopen_or_warn(filename, "r");
7963 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7964 return EXIT_FAILURE;
7966 close_on_exec_on(fileno(input));
7968 #if ENABLE_HUSH_FUNCTIONS
7969 sv_flg = G.flag_return_in_progress;
7970 /* "we are inside sourced file, ok to use return" */
7971 G.flag_return_in_progress = -1;
7973 save_and_replace_G_args(&sv, argv);
7975 parse_and_run_file(input);
7978 restore_G_args(&sv, argv);
7979 #if ENABLE_HUSH_FUNCTIONS
7980 G.flag_return_in_progress = sv_flg;
7983 return G.last_exitcode;
7986 static int FAST_FUNC builtin_umask(char **argv)
7992 argv = skip_dash_dash(argv);
7994 mode_t old_mask = mask;
7997 rc = bb_parse_mode(argv[0], &mask);
8002 * bash: umask: 'q': invalid symbolic mode operator
8003 * bash: umask: 999: octal number out of range
8005 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8010 printf("%04o\n", (unsigned) mask);
8011 /* fall through and restore mask which we set to 0 */
8015 return !rc; /* rc != 0 - success */
8018 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8019 static int FAST_FUNC builtin_unset(char **argv)
8024 /* "!": do not abort on errors */
8025 /* "+": stop at 1st non-option */
8026 opts = getopt32(argv, "!+vf");
8027 if (opts == (unsigned)-1)
8028 return EXIT_FAILURE;
8030 bb_error_msg("unset: -v and -f are exclusive");
8031 return EXIT_FAILURE;
8037 if (!(opts & 2)) { /* not -f */
8038 if (unset_local_var(*argv)) {
8039 /* unset <nonexistent_var> doesn't fail.
8040 * Error is when one tries to unset RO var.
8041 * Message was printed by unset_local_var. */
8045 #if ENABLE_HUSH_FUNCTIONS
8055 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8056 static int FAST_FUNC builtin_wait(char **argv)
8058 int ret = EXIT_SUCCESS;
8061 argv = skip_dash_dash(argv);
8062 if (argv[0] == NULL) {
8063 /* Don't care about wait results */
8064 /* Note 1: must wait until there are no more children */
8065 /* Note 2: must be interruptible */
8067 * $ sleep 3 & sleep 6 & wait
8072 * $ sleep 3 & sleep 6 & wait
8076 * ^C <-- after ~4 sec from keyboard
8079 sigaddset(&G.blocked_set, SIGCHLD);
8080 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8083 if (errno == ECHILD)
8085 /* Wait for SIGCHLD or any other signal of interest */
8086 /* sigtimedwait with infinite timeout: */
8087 sig = sigwaitinfo(&G.blocked_set, NULL);
8089 sig = check_and_run_traps(sig);
8090 if (sig && sig != SIGCHLD) { /* see note 2 */
8096 sigdelset(&G.blocked_set, SIGCHLD);
8097 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8101 /* This is probably buggy wrt interruptible-ness */
8103 pid_t pid = bb_strtou(*argv, NULL, 10);
8105 /* mimic bash message */
8106 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8107 return EXIT_FAILURE;
8109 if (waitpid(pid, &status, 0) == pid) {
8110 if (WIFSIGNALED(status))
8111 ret = 128 + WTERMSIG(status);
8112 else if (WIFEXITED(status))
8113 ret = WEXITSTATUS(status);
8117 bb_perror_msg("wait %s", *argv);
8126 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8127 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8130 def = bb_strtou(argv[1], NULL, 10);
8131 if (errno || def < def_min || argv[2]) {
8132 bb_error_msg("%s: bad arguments", argv[0]);
8140 #if ENABLE_HUSH_LOOPS
8141 static int FAST_FUNC builtin_break(char **argv)
8144 if (G.depth_of_loop == 0) {
8145 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8146 return EXIT_SUCCESS; /* bash compat */
8148 G.flag_break_continue++; /* BC_BREAK = 1 */
8150 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8151 if (depth == UINT_MAX)
8152 G.flag_break_continue = BC_BREAK;
8153 if (G.depth_of_loop < depth)
8154 G.depth_break_continue = G.depth_of_loop;
8156 return EXIT_SUCCESS;
8159 static int FAST_FUNC builtin_continue(char **argv)
8161 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8162 return builtin_break(argv);
8166 #if ENABLE_HUSH_FUNCTIONS
8167 static int FAST_FUNC builtin_return(char **argv)
8171 if (G.flag_return_in_progress != -1) {
8172 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8173 return EXIT_FAILURE; /* bash compat */
8176 G.flag_return_in_progress = 1;
8179 * out of range: wraps around at 256, does not error out
8180 * non-numeric param:
8181 * f() { false; return qwe; }; f; echo $?
8182 * bash: return: qwe: numeric argument required <== we do this
8183 * 255 <== we also do this
8185 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);