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 /* Expand all variable references in given string, adding words to list[]
2407 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2408 * to be filled). This routine is extremely tricky: has to deal with
2409 * variables/parameters with whitespace, $* and $@, and constructs like
2410 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2411 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2413 /* or_mask is either 0 (normal case) or 0x80 -
2414 * expansion of right-hand side of assignment == 1-element expand.
2415 * It will also do no globbing, and thus we must not backslash-quote!
2422 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2423 debug_print_list("expand_vars_to_list", output, n);
2424 n = o_save_ptr(output, n);
2425 debug_print_list("expand_vars_to_list[0]", output, n);
2427 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2430 char *dyn_val = NULL;
2431 const char *val = NULL;
2432 #if ENABLE_HUSH_TICK
2433 o_string subst_result = NULL_O_STRING;
2435 #if ENABLE_SH_MATH_SUPPORT
2436 char arith_buf[sizeof(arith_t)*3 + 2];
2438 o_addblock(output, arg, p - arg);
2439 debug_print_list("expand_vars_to_list[1]", output, n);
2441 p = strchr(p, SPECIAL_VAR_SYMBOL);
2443 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2444 /* "$@" is special. Even if quoted, it can still
2445 * expand to nothing (not even an empty string) */
2446 if ((first_ch & 0x7f) != '@')
2447 ored_ch |= first_ch;
2449 switch (first_ch & 0x7f) {
2450 /* Highest bit in first_ch indicates that var is double-quoted */
2452 val = utoa(G.root_pid);
2454 case '!': /* bg pid */
2455 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2457 case '?': /* exitcode */
2458 val = utoa(G.last_exitcode);
2460 case '#': /* argc */
2461 if (arg[1] != SPECIAL_VAR_SYMBOL)
2462 /* actually, it's a ${#var} */
2464 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2469 if (!G.global_argv[i])
2471 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2472 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2473 smallint sv = output->o_escape;
2474 /* unquoted var's contents should be globbed, so don't escape */
2475 output->o_escape = 0;
2476 while (G.global_argv[i]) {
2477 n = expand_on_ifs(output, n, G.global_argv[i]);
2478 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2479 if (G.global_argv[i++][0] && G.global_argv[i]) {
2480 /* this argv[] is not empty and not last:
2481 * put terminating NUL, start new word */
2482 o_addchr(output, '\0');
2483 debug_print_list("expand_vars_to_list[2]", output, n);
2484 n = o_save_ptr(output, n);
2485 debug_print_list("expand_vars_to_list[3]", output, n);
2488 output->o_escape = sv;
2490 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2491 * and in this case should treat it like '$*' - see 'else...' below */
2492 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2494 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2495 if (++i >= G.global_argc)
2497 o_addchr(output, '\0');
2498 debug_print_list("expand_vars_to_list[4]", output, n);
2499 n = o_save_ptr(output, n);
2501 } else { /* quoted $*: add as one word */
2503 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2504 if (!G.global_argv[++i])
2507 o_addchr(output, G.ifs[0]);
2511 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2512 /* "Empty variable", used to make "" etc to not disappear */
2516 #if ENABLE_HUSH_TICK
2517 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2520 /* Can't just stuff it into output o_string,
2521 * expanded result may need to be globbed
2522 * and $IFS-splitted */
2523 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2524 G.last_exitcode = process_command_subs(&subst_result, arg);
2525 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2526 val = subst_result.data;
2529 #if ENABLE_SH_MATH_SUPPORT
2530 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2531 arith_eval_hooks_t hooks;
2536 arg++; /* skip '+' */
2537 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2538 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2540 exp_str = expand_pseudo_dquoted(arg);
2541 hooks.lookupvar = get_local_var_value;
2542 hooks.setvar = set_local_var_from_halves;
2543 hooks.endofname = endofname;
2544 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2548 const char *msg = "error in arithmetic";
2551 msg = "exponent less than 0";
2554 msg = "divide by 0";
2557 msg = "expression recursion loop detected";
2562 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2563 sprintf(arith_buf, arith_t_fmt, res);
2568 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2571 char exp_len; /* '#' if it's ${#var} */
2573 char exp_save = exp_save; /* for compiler */
2574 char *exp_saveptr = exp_saveptr; /* points to expansion operator */
2575 char *exp_word = exp_word; /* for compiler */
2578 arg[0] = first_ch & 0x7f;
2580 /* prepare for expansions */
2583 if (exp_len == '#') {
2584 /* handle length expansion ${#var} */
2587 /* maybe handle parameter expansion */
2588 exp_saveptr = var + strcspn(var, "%#:-=+?");
2589 exp_save = *exp_saveptr;
2591 exp_word = exp_saveptr;
2592 if (exp_save == ':')
2594 exp_op = *exp_word++;
2595 *exp_saveptr = '\0';
2599 /* lookup the variable in question */
2600 if (isdigit(var[0])) {
2601 /* handle_dollar() should have vetted var for us */
2603 if (i < G.global_argc)
2604 val = G.global_argv[i];
2605 /* else val remains NULL: $N with too big N */
2607 val = get_local_var_value(var);
2609 /* handle any expansions */
2610 if (exp_len == '#') {
2611 debug_printf_expand("expand: length(%s)=", val);
2612 val = utoa(val ? strlen(val) : 0);
2613 debug_printf_expand("%s\n", val);
2614 } else if (exp_op) {
2615 if (exp_op == '%' || exp_op == '#') {
2616 /* Standard-mandated substring removal ops:
2617 * ${parameter%word} - remove smallest suffix pattern
2618 * ${parameter%%word} - remove largest suffix pattern
2619 * ${parameter#word} - remove smallest prefix pattern
2620 * ${parameter##word} - remove largest prefix pattern
2622 * Word is expanded to produce a glob pattern.
2623 * Then var's value is matched to it and matching part removed.
2628 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2629 if (exp_op == *exp_word) /* ## or %% */
2631 val = dyn_val = xstrdup(val);
2632 loc = scan(dyn_val, exp_word, match_at_left);
2633 if (match_at_left) /* # or ## */
2635 else if (loc) /* % or %% and match was found */
2638 } else if (!strchr("%#:-=+?"+3, exp_op)) {
2639 #if ENABLE_HUSH_BASH_COMPAT
2640 /* exp_op is ':' and next char isn't a subst operator.
2641 * Assuming it's ${var:[N][:M]} bashism.
2642 * TODO: N, M can be expressions similar to $((EXPR)): 2+2, 2+var etc
2645 unsigned len = INT_MAX;
2648 if (*exp_word != ':') /* not ${var::...} */
2649 beg = bb_strtou(exp_word, &end, 0);
2650 //bb_error_msg("beg:'%s'=%u end:'%s'", exp_word, beg, end);
2652 if (end[1] != '\0') /* not ${var:NUM:} */
2653 len = bb_strtou(end + 1, &end, 0);
2658 //bb_error_msg("len:%u end:'%s'", len, end);
2661 //bb_error_msg("from val:'%s'", val);
2662 if (len == 0 || !val || beg >= strlen(val))
2665 val = dyn_val = xstrndup(val + beg, len);
2666 //bb_error_msg("val:'%s'", val);
2670 die_if_script("malformed ${%s...}", var);
2673 } else { /* one of "-=+?" */
2674 /* Standard-mandated substitution ops:
2675 * ${var?word} - indicate error if unset
2676 * If var is unset, word (or a message indicating it is unset
2677 * if word is null) is written to standard error
2678 * and the shell exits with a non-zero exit status.
2679 * Otherwise, the value of var is substituted.
2680 * ${var-word} - use default value
2681 * If var is unset, word is substituted.
2682 * ${var=word} - assign and use default value
2683 * If var is unset, word is assigned to var.
2684 * In all cases, final value of var is substituted.
2685 * ${var+word} - use alternative value
2686 * If var is unset, null is substituted.
2687 * Otherwise, word is substituted.
2689 * Word is subjected to tilde expansion, parameter expansion,
2690 * command substitution, and arithmetic expansion.
2691 * If word is not needed, it is not expanded.
2693 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2694 * but also treat null var as if it is unset.
2696 int use_word = (!val || ((exp_save == ':') && !val[0]));
2698 use_word = !use_word;
2699 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2700 (exp_save == ':') ? "true" : "false", use_word);
2702 if (exp_op == '?') {
2703 //TODO: how interactive bash aborts expansion mid-command?
2704 /* mimic bash message */
2705 die_if_script("%s: %s",
2707 exp_word[0] ? exp_word : "parameter null or not set"
2713 if (exp_op == '=') {
2714 /* ${var=[word]} or ${var:=[word]} */
2715 if (isdigit(var[0]) || var[0] == '#') {
2716 /* mimic bash message */
2717 die_if_script("$%s: cannot assign in this way", var);
2720 char *new_var = xasprintf("%s=%s", var, val);
2721 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2727 *exp_saveptr = exp_save;
2731 #if ENABLE_HUSH_TICK
2734 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2735 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2737 /* unquoted var's contents should be globbed, so don't escape */
2738 smallint sv = output->o_escape;
2739 output->o_escape = 0;
2740 n = expand_on_ifs(output, n, val);
2742 output->o_escape = sv;
2744 } else { /* quoted $VAR, val will be appended below */
2745 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2748 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2751 o_addQstr(output, val, strlen(val));
2754 /* Do the check to avoid writing to a const string */
2755 if (*p != SPECIAL_VAR_SYMBOL)
2756 *p = SPECIAL_VAR_SYMBOL;
2758 #if ENABLE_HUSH_TICK
2759 o_free(&subst_result);
2762 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2765 debug_print_list("expand_vars_to_list[a]", output, n);
2766 /* this part is literal, and it was already pre-quoted
2767 * if needed (much earlier), do not use o_addQstr here! */
2768 o_addstr_with_NUL(output, arg);
2769 debug_print_list("expand_vars_to_list[b]", output, n);
2770 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2771 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2774 /* allow to reuse list[n] later without re-growth */
2775 output->has_empty_slot = 1;
2777 o_addchr(output, '\0');
2782 static char **expand_variables(char **argv, int or_mask)
2787 o_string output = NULL_O_STRING;
2789 if (or_mask & 0x100) {
2790 output.o_escape = 1; /* protect against globbing for "$var" */
2791 /* (unquoted $var will temporarily switch it off) */
2798 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2801 debug_print_list("expand_variables", &output, n);
2803 /* output.data (malloced in one block) gets returned in "list" */
2804 list = o_finalize_list(&output, n);
2805 debug_print_strings("expand_variables[1]", list);
2809 static char **expand_strvec_to_strvec(char **argv)
2811 return expand_variables(argv, 0x100);
2814 #if ENABLE_HUSH_BASH_COMPAT
2815 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2817 return expand_variables(argv, 0x80);
2821 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2822 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2827 o_string output = NULL_O_STRING;
2832 int is_var = is_well_formed_var_name(*v, '=');
2833 /* is_var * 0x80: singleword expansion for vars */
2834 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2836 /* Subtle! expand_vars_to_list did not glob last word yet.
2837 * It does this only when fed with further data.
2838 * Therefore we set globbing flags AFTER it, not before:
2841 /* if it is not recognizably abc=...; then: */
2842 output.o_escape = !is_var; /* protect against globbing for "$var" */
2843 /* (unquoted $var will temporarily switch it off) */
2844 output.o_glob = !is_var; /* and indeed do globbing */
2847 debug_print_list("expand_cond", &output, n);
2849 /* output.data (malloced in one block) gets returned in "list" */
2850 list = o_finalize_list(&output, n);
2851 debug_print_strings("expand_cond[1]", list);
2856 /* Used for expansion of right hand of assignments */
2857 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2859 static char *expand_string_to_string(const char *str)
2861 char *argv[2], **list;
2863 argv[0] = (char*)str;
2865 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2867 if (!list[0] || list[1])
2868 bb_error_msg_and_die("BUG in varexp2");
2869 /* actually, just move string 2*sizeof(char*) bytes back */
2870 overlapping_strcpy((char*)list, list[0]);
2871 unbackslash((char*)list);
2872 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2876 /* Used for "eval" builtin */
2877 static char* expand_strvec_to_string(char **argv)
2881 list = expand_variables(argv, 0x80);
2882 /* Convert all NULs to spaces */
2887 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2888 bb_error_msg_and_die("BUG in varexp3");
2889 /* bash uses ' ' regardless of $IFS contents */
2894 overlapping_strcpy((char*)list, list[0]);
2895 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2899 static char **expand_assignments(char **argv, int count)
2903 /* Expand assignments into one string each */
2904 for (i = 0; i < count; i++) {
2905 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2913 void re_execute_shell(char ***to_free, const char *s,
2914 char *g_argv0, char **g_argv,
2915 char **builtin_argv) NORETURN;
2917 static void reset_traps_to_defaults(void)
2919 /* This function is always called in a child shell
2920 * after fork (not vfork, NOMMU doesn't use this function).
2925 /* Child shells are not interactive.
2926 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2927 * Testcase: (while :; do :; done) + ^Z should background.
2928 * Same goes for SIGTERM, SIGHUP, SIGINT.
2930 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2931 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2933 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2934 * Stupid. It can be done with *single* &= op, but we can't use
2935 * the fact that G.blocked_set is implemented as a bitmask
2937 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2941 /* Careful. Only if no trap or trap is not "" */
2942 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2943 sigdelset(&G.blocked_set, sig);
2950 /* Our homegrown sig mask is saner to work with :) */
2951 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2953 /* Resetting all traps to default except empty ones */
2954 mask = G.non_DFL_mask;
2955 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2956 if (!G.traps[sig] || !G.traps[sig][0])
2959 G.traps[sig] = NULL;
2960 /* There is no signal for 0 (EXIT) */
2963 /* There was a trap handler, we just removed it.
2964 * But if sig still has non-DFL handling,
2965 * we should not unblock the sig. */
2968 sigdelset(&G.blocked_set, sig);
2970 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2975 static void re_execute_shell(char ***to_free, const char *s,
2976 char *g_argv0, char **g_argv,
2977 char **builtin_argv) NORETURN;
2978 static void re_execute_shell(char ***to_free, const char *s,
2979 char *g_argv0, char **g_argv,
2980 char **builtin_argv)
2982 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
2983 /* delims + 2 * (number of bytes in printed hex numbers) */
2984 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
2985 char *heredoc_argv[4];
2986 struct variable *cur;
2987 # if ENABLE_HUSH_FUNCTIONS
2988 struct function *funcp;
2992 unsigned long long empty_trap_mask;
2994 if (!g_argv0) { /* heredoc */
2995 argv = heredoc_argv;
2996 argv[0] = (char *) G.argv0_for_re_execing;
2997 argv[1] = (char *) "-<";
2998 argv[2] = (char *) s;
3000 pp = &argv[3]; /* used as pointer to empty environment */
3006 if (pp) while (*pp++)
3009 empty_trap_mask = 0;
3012 for (sig = 1; sig < NSIG; sig++) {
3013 if (G.traps[sig] && !G.traps[sig][0])
3014 empty_trap_mask |= 1LL << sig;
3018 sprintf(param_buf, NOMMU_HACK_FMT
3019 , (unsigned) G.root_pid
3020 , (unsigned) G.root_ppid
3021 , (unsigned) G.last_bg_pid
3022 , (unsigned) G.last_exitcode
3025 IF_HUSH_LOOPS(, G.depth_of_loop)
3027 #undef NOMMU_HACK_FMT
3028 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3029 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3032 for (cur = G.top_var; cur; cur = cur->next) {
3033 if (!cur->flg_export || cur->flg_read_only)
3036 # if ENABLE_HUSH_FUNCTIONS
3037 for (funcp = G.top_func; funcp; funcp = funcp->next)
3043 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3044 *pp++ = (char *) G.argv0_for_re_execing;
3046 for (cur = G.top_var; cur; cur = cur->next) {
3047 if (cur->varstr == hush_version_str)
3049 if (cur->flg_read_only) {
3050 *pp++ = (char *) "-R";
3051 *pp++ = cur->varstr;
3052 } else if (!cur->flg_export) {
3053 *pp++ = (char *) "-V";
3054 *pp++ = cur->varstr;
3057 # if ENABLE_HUSH_FUNCTIONS
3058 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3059 *pp++ = (char *) "-F";
3060 *pp++ = funcp->name;
3061 *pp++ = funcp->body_as_string;
3064 /* We can pass activated traps here. Say, -Tnn:trap_string
3066 * However, POSIX says that subshells reset signals with traps
3068 * I tested bash-3.2 and it not only does that with true subshells
3069 * of the form ( list ), but with any forked children shells.
3070 * I set trap "echo W" WINCH; and then tried:
3072 * { echo 1; sleep 20; echo 2; } &
3073 * while true; do echo 1; sleep 20; echo 2; break; done &
3074 * true | { echo 1; sleep 20; echo 2; } | cat
3076 * In all these cases sending SIGWINCH to the child shell
3077 * did not run the trap. If I add trap "echo V" WINCH;
3078 * _inside_ group (just before echo 1), it works.
3080 * I conclude it means we don't need to pass active traps here.
3081 * Even if we would use signal handlers instead of signal masking
3082 * in order to implement trap handling,
3083 * exec syscall below resets signals to SIG_DFL for us.
3085 *pp++ = (char *) "-c";
3088 while (*++builtin_argv)
3089 *pp++ = *builtin_argv;
3090 *pp++ = (char *) "";
3095 /* *pp = NULL; - is already there */
3099 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3100 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3101 execve(bb_busybox_exec_path, argv, pp);
3102 /* Fallback. Useful for init=/bin/hush usage etc */
3103 if (argv[0][0] == '/')
3104 execve(argv[0], argv, pp);
3105 xfunc_error_retval = 127;
3106 bb_error_msg_and_die("can't re-execute the shell");
3108 #endif /* !BB_MMU */
3111 static void setup_heredoc(struct redir_struct *redir)
3113 struct fd_pair pair;
3116 /* the _body_ of heredoc (misleading field name) */
3117 const char *heredoc = redir->rd_filename;
3124 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3125 expanded = expand_pseudo_dquoted(heredoc);
3129 len = strlen(heredoc);
3131 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3133 xmove_fd(pair.rd, redir->rd_fd);
3135 /* Try writing without forking. Newer kernels have
3136 * dynamically growing pipes. Must use non-blocking write! */
3139 written = write(pair.wr, heredoc, len);
3150 ndelay_off(pair.wr);
3152 /* Okay, pipe buffer was not big enough */
3153 /* Note: we must not create a stray child (bastard? :)
3154 * for the unsuspecting parent process. Child creates a grandchild
3155 * and exits before parent execs the process which consumes heredoc
3156 * (that exec happens after we return from this function) */
3162 bb_perror_msg_and_die("vfork");
3165 disable_restore_tty_pgrp_on_exit();
3166 pid = BB_MMU ? fork() : vfork();
3168 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3172 close(redir->rd_fd); /* read side of the pipe */
3174 full_write(pair.wr, heredoc, len); /* may loop or block */
3177 /* Delegate blocking writes to another process */
3178 xmove_fd(pair.wr, STDOUT_FILENO);
3179 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3183 #if ENABLE_HUSH_FAST
3185 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3187 enable_restore_tty_pgrp_on_exit();
3193 wait(NULL); /* wait till child has died */
3196 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3197 * and stderr if they are redirected. */
3198 static int setup_redirects(struct command *prog, int squirrel[])
3201 struct redir_struct *redir;
3203 for (redir = prog->redirects; redir; redir = redir->next) {
3204 if (redir->rd_type == REDIRECT_HEREDOC2) {
3205 /* rd_fd<<HERE case */
3206 if (squirrel && redir->rd_fd < 3
3207 && squirrel[redir->rd_fd] < 0
3209 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3211 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3213 debug_printf_parse("set heredoc '%s'\n",
3214 redir->rd_filename);
3215 setup_heredoc(redir);
3219 if (redir->rd_dup == REDIRFD_TO_FILE) {
3220 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3222 if (redir->rd_filename == NULL) {
3223 /* Something went wrong in the parse.
3224 * Pretend it didn't happen */
3225 bb_error_msg("bug in redirect parse");
3228 mode = redir_table[redir->rd_type].mode;
3229 p = expand_string_to_string(redir->rd_filename);
3230 openfd = open_or_warn(p, mode);
3233 /* this could get lost if stderr has been redirected, but
3234 * bash and ash both lose it as well (though zsh doesn't!) */
3235 //what the above comment tries to say?
3239 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3240 openfd = redir->rd_dup;
3243 if (openfd != redir->rd_fd) {
3244 if (squirrel && redir->rd_fd < 3
3245 && squirrel[redir->rd_fd] < 0
3247 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3249 if (openfd == REDIRFD_CLOSE) {
3250 /* "n>-" means "close me" */
3251 close(redir->rd_fd);
3253 xdup2(openfd, redir->rd_fd);
3254 if (redir->rd_dup == REDIRFD_TO_FILE)
3262 static void restore_redirects(int squirrel[])
3265 for (i = 0; i < 3; i++) {
3268 /* We simply die on error */
3275 static void free_pipe_list(struct pipe *head);
3277 /* Return code is the exit status of the pipe */
3278 static void free_pipe(struct pipe *pi)
3281 struct command *command;
3282 struct redir_struct *r, *rnext;
3285 if (pi->stopped_cmds > 0) /* why? */
3287 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3288 for (i = 0; i < pi->num_cmds; i++) {
3289 command = &pi->cmds[i];
3290 debug_printf_clean(" command %d:\n", i);
3291 if (command->argv) {
3292 for (a = 0, p = command->argv; *p; a++, p++) {
3293 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3295 free_strings(command->argv);
3296 command->argv = NULL;
3298 /* not "else if": on syntax error, we may have both! */
3299 if (command->group) {
3300 debug_printf_clean(" begin group (cmd_type:%d)\n",
3302 free_pipe_list(command->group);
3303 debug_printf_clean(" end group\n");
3304 command->group = NULL;
3306 /* else is crucial here.
3307 * If group != NULL, child_func is meaningless */
3308 #if ENABLE_HUSH_FUNCTIONS
3309 else if (command->child_func) {
3310 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3311 command->child_func->parent_cmd = NULL;
3315 free(command->group_as_string);
3316 command->group_as_string = NULL;
3318 for (r = command->redirects; r; r = rnext) {
3319 debug_printf_clean(" redirect %d%s",
3320 r->rd_fd, redir_table[r->rd_type].descrip);
3321 /* guard against the case >$FOO, where foo is unset or blank */
3322 if (r->rd_filename) {
3323 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3324 free(r->rd_filename);
3325 r->rd_filename = NULL;
3327 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3331 command->redirects = NULL;
3333 free(pi->cmds); /* children are an array, they get freed all at once */
3341 static void free_pipe_list(struct pipe *head)
3343 struct pipe *pi, *next;
3345 for (pi = head; pi; pi = next) {
3347 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3350 debug_printf_clean("pipe followup code %d\n", pi->followup);
3352 /*pi->next = NULL;*/
3358 static int run_list(struct pipe *pi);
3360 #define parse_stream(pstring, input, end_trigger) \
3361 parse_stream(input, end_trigger)
3363 static struct pipe *parse_stream(char **pstring,
3364 struct in_str *input,
3366 static void parse_and_run_string(const char *s);
3369 static char *find_in_path(const char *arg)
3372 const char *PATH = get_local_var_value("PATH");
3378 const char *end = strchrnul(PATH, ':');
3379 int sz = end - PATH; /* must be int! */
3383 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3385 /* We have xxx::yyyy in $PATH,
3386 * it means "use current dir" */
3389 if (access(ret, F_OK) == 0)
3402 static const struct built_in_command* find_builtin_helper(const char *name,
3403 const struct built_in_command *x,
3404 const struct built_in_command *end)
3407 if (strcmp(name, x->b_cmd) != 0) {
3411 debug_printf_exec("found builtin '%s'\n", name);
3416 static const struct built_in_command* find_builtin1(const char *name)
3418 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3420 static const struct built_in_command* find_builtin(const char *name)
3422 const struct built_in_command *x = find_builtin1(name);
3425 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3428 #if ENABLE_HUSH_FUNCTIONS
3429 static struct function **find_function_slot(const char *name)
3431 struct function **funcpp = &G.top_func;
3433 if (strcmp(name, (*funcpp)->name) == 0) {
3436 funcpp = &(*funcpp)->next;
3441 static const struct function *find_function(const char *name)
3443 const struct function *funcp = *find_function_slot(name);
3445 debug_printf_exec("found function '%s'\n", name);
3449 /* Note: takes ownership on name ptr */
3450 static struct function *new_function(char *name)
3452 struct function **funcpp = find_function_slot(name);
3453 struct function *funcp = *funcpp;
3455 if (funcp != NULL) {
3456 struct command *cmd = funcp->parent_cmd;
3457 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3459 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3461 /* Note: if !funcp->body, do not free body_as_string!
3462 * This is a special case of "-F name body" function:
3463 * body_as_string was not malloced! */
3465 free_pipe_list(funcp->body);
3467 free(funcp->body_as_string);
3471 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3472 cmd->argv[0] = funcp->name;
3473 cmd->group = funcp->body;
3475 cmd->group_as_string = funcp->body_as_string;
3479 debug_printf_exec("remembering new function '%s'\n", name);
3480 funcp = *funcpp = xzalloc(sizeof(*funcp));
3481 /*funcp->next = NULL;*/
3488 static void unset_func(const char *name)
3490 struct function **funcpp = find_function_slot(name);
3491 struct function *funcp = *funcpp;
3493 if (funcp != NULL) {
3494 debug_printf_exec("freeing function '%s'\n", funcp->name);
3495 *funcpp = funcp->next;
3496 /* funcp is unlinked now, deleting it.
3497 * Note: if !funcp->body, the function was created by
3498 * "-F name body", do not free ->body_as_string
3499 * and ->name as they were not malloced. */
3501 free_pipe_list(funcp->body);
3504 free(funcp->body_as_string);
3512 #define exec_function(to_free, funcp, argv) \
3513 exec_function(funcp, argv)
3515 static void exec_function(char ***to_free,
3516 const struct function *funcp,
3517 char **argv) NORETURN;
3518 static void exec_function(char ***to_free,
3519 const struct function *funcp,
3525 argv[0] = G.global_argv[0];
3526 G.global_argv = argv;
3530 /* On MMU, funcp->body is always non-NULL */
3531 n = run_list(funcp->body);
3535 re_execute_shell(to_free,
3536 funcp->body_as_string,
3543 static int run_function(const struct function *funcp, char **argv)
3549 save_and_replace_G_args(&sv, argv);
3551 /* "we are in function, ok to use return" */
3552 sv_flg = G.flag_return_in_progress;
3553 G.flag_return_in_progress = -1;
3554 # if ENABLE_HUSH_LOCAL
3555 G.func_nest_level++;
3558 /* On MMU, funcp->body is always non-NULL */
3561 /* Function defined by -F */
3562 parse_and_run_string(funcp->body_as_string);
3563 rc = G.last_exitcode;
3567 rc = run_list(funcp->body);
3570 # if ENABLE_HUSH_LOCAL
3572 struct variable *var;
3573 struct variable **var_pp;
3575 var_pp = &G.top_var;
3576 while ((var = *var_pp) != NULL) {
3577 if (var->func_nest_level < G.func_nest_level) {
3578 var_pp = &var->next;
3582 if (var->flg_export)
3583 bb_unsetenv(var->varstr);
3584 /* Remove from global list */
3585 *var_pp = var->next;
3591 G.func_nest_level--;
3594 G.flag_return_in_progress = sv_flg;
3596 restore_G_args(&sv, argv);
3600 #endif /* ENABLE_HUSH_FUNCTIONS */
3604 #define exec_builtin(to_free, x, argv) \
3605 exec_builtin(x, argv)
3607 #define exec_builtin(to_free, x, argv) \
3608 exec_builtin(to_free, argv)
3610 static void exec_builtin(char ***to_free,
3611 const struct built_in_command *x,
3612 char **argv) NORETURN;
3613 static void exec_builtin(char ***to_free,
3614 const struct built_in_command *x,
3618 int rcode = x->b_function(argv);
3622 /* On NOMMU, we must never block!
3623 * Example: { sleep 99 | read line; } & echo Ok
3625 re_execute_shell(to_free,
3634 static void execvp_or_die(char **argv) NORETURN;
3635 static void execvp_or_die(char **argv)
3637 debug_printf_exec("execing '%s'\n", argv[0]);
3638 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3639 execvp(argv[0], argv);
3640 bb_perror_msg("can't execute '%s'", argv[0]);
3641 _exit(127); /* bash compat */
3645 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3646 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3647 #define pseudo_exec(nommu_save, command, argv_expanded) \
3648 pseudo_exec(command, argv_expanded)
3651 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3653 * Don't exit() here. If you don't exec, use _exit instead.
3654 * The at_exit handlers apparently confuse the calling process,
3655 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3656 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3657 char **argv, int assignment_cnt,
3658 char **argv_expanded) NORETURN;
3659 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3660 char **argv, int assignment_cnt,
3661 char **argv_expanded)
3665 /* Case when we are here: ... | var=val | ... */
3666 if (!argv[assignment_cnt])
3667 _exit(EXIT_SUCCESS);
3669 new_env = expand_assignments(argv, assignment_cnt);
3671 set_vars_and_save_old(new_env);
3672 free(new_env); /* optional */
3673 /* we can also destroy set_vars_and_save_old's return value,
3676 nommu_save->new_env = new_env;
3677 nommu_save->old_vars = set_vars_and_save_old(new_env);
3679 if (argv_expanded) {
3680 argv = argv_expanded;
3682 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3684 nommu_save->argv = argv;
3688 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3689 if (strchr(argv[0], '/') != NULL)
3693 /* Check if the command matches any of the builtins.
3694 * Depending on context, this might be redundant. But it's
3695 * easier to waste a few CPU cycles than it is to figure out
3696 * if this is one of those cases.
3699 /* On NOMMU, it is more expensive to re-execute shell
3700 * just in order to run echo or test builtin.
3701 * It's better to skip it here and run corresponding
3702 * non-builtin later. */
3703 const struct built_in_command *x;
3704 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3706 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3709 #if ENABLE_HUSH_FUNCTIONS
3710 /* Check if the command matches any functions */
3712 const struct function *funcp = find_function(argv[0]);
3714 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3719 #if ENABLE_FEATURE_SH_STANDALONE
3720 /* Check if the command matches any busybox applets */
3722 int a = find_applet_by_name(argv[0]);
3724 # if BB_MMU /* see above why on NOMMU it is not allowed */
3725 if (APPLET_IS_NOEXEC(a)) {
3726 debug_printf_exec("running applet '%s'\n", argv[0]);
3727 run_applet_no_and_exit(a, argv);
3730 /* Re-exec ourselves */
3731 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3732 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3733 execv(bb_busybox_exec_path, argv);
3734 /* If they called chroot or otherwise made the binary no longer
3735 * executable, fall through */
3740 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3743 execvp_or_die(argv);
3746 /* Called after [v]fork() in run_pipe
3748 static void pseudo_exec(nommu_save_t *nommu_save,
3749 struct command *command,
3750 char **argv_expanded) NORETURN;
3751 static void pseudo_exec(nommu_save_t *nommu_save,
3752 struct command *command,
3753 char **argv_expanded)
3755 if (command->argv) {
3756 pseudo_exec_argv(nommu_save, command->argv,
3757 command->assignment_cnt, argv_expanded);
3760 if (command->group) {
3761 /* Cases when we are here:
3764 * ... | ( list ) | ...
3765 * ... | { list } | ...
3769 debug_printf_exec("pseudo_exec: run_list\n");
3770 reset_traps_to_defaults();
3771 rcode = run_list(command->group);
3772 /* OK to leak memory by not calling free_pipe_list,
3773 * since this process is about to exit */
3776 re_execute_shell(&nommu_save->argv_from_re_execing,
3777 command->group_as_string,
3784 /* Case when we are here: ... | >file */
3785 debug_printf_exec("pseudo_exec'ed null command\n");
3786 _exit(EXIT_SUCCESS);
3790 static const char *get_cmdtext(struct pipe *pi)
3796 /* This is subtle. ->cmdtext is created only on first backgrounding.
3797 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3798 * On subsequent bg argv is trashed, but we won't use it */
3801 argv = pi->cmds[0].argv;
3802 if (!argv || !argv[0]) {
3803 pi->cmdtext = xzalloc(1);
3809 len += strlen(*argv) + 1;
3813 argv = pi->cmds[0].argv;
3815 len = strlen(*argv);
3816 memcpy(p, *argv, len);
3824 static void insert_bg_job(struct pipe *pi)
3826 struct pipe *job, **jobp;
3829 /* Linear search for the ID of the job to use */
3831 for (job = G.job_list; job; job = job->next)
3832 if (job->jobid >= pi->jobid)
3833 pi->jobid = job->jobid + 1;
3835 /* Add job to the list of running jobs */
3837 while ((job = *jobp) != NULL)
3839 job = *jobp = xmalloc(sizeof(*job));
3841 *job = *pi; /* physical copy */
3843 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3844 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3845 for (i = 0; i < pi->num_cmds; i++) {
3846 job->cmds[i].pid = pi->cmds[i].pid;
3847 /* all other fields are not used and stay zero */
3849 job->cmdtext = xstrdup(get_cmdtext(pi));
3851 if (G_interactive_fd)
3852 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3853 /* Last command's pid goes to $! */
3854 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3855 G.last_jobid = job->jobid;
3858 static void remove_bg_job(struct pipe *pi)
3860 struct pipe *prev_pipe;
3862 if (pi == G.job_list) {
3863 G.job_list = pi->next;
3865 prev_pipe = G.job_list;
3866 while (prev_pipe->next != pi)
3867 prev_pipe = prev_pipe->next;
3868 prev_pipe->next = pi->next;
3871 G.last_jobid = G.job_list->jobid;
3876 /* Remove a backgrounded job */
3877 static void delete_finished_bg_job(struct pipe *pi)
3880 pi->stopped_cmds = 0;
3886 /* Check to see if any processes have exited -- if they
3887 * have, figure out why and see if a job has completed */
3888 static int checkjobs(struct pipe* fg_pipe)
3898 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3900 attributes = WUNTRACED;
3901 if (fg_pipe == NULL)
3902 attributes |= WNOHANG;
3905 #if ENABLE_HUSH_FAST
3906 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3907 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3908 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3909 /* There was neither fork nor SIGCHLD since last waitpid */
3910 /* Avoid doing waitpid syscall if possible */
3911 if (!G.we_have_children) {
3915 if (fg_pipe == NULL) { /* is WNOHANG set? */
3916 /* We have children, but they did not exit
3917 * or stop yet (we saw no SIGCHLD) */
3920 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3924 /* Do we do this right?
3925 * bash-3.00# sleep 20 | false
3927 * [3]+ Stopped sleep 20 | false
3928 * bash-3.00# echo $?
3929 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3930 * [hush 1.14.0: yes we do it right]
3937 #if ENABLE_HUSH_FAST
3938 i = G.count_SIGCHLD;
3940 childpid = waitpid(-1, &status, attributes);
3941 if (childpid <= 0) {
3942 if (childpid && errno != ECHILD)
3943 bb_perror_msg("waitpid");
3944 #if ENABLE_HUSH_FAST
3945 else { /* Until next SIGCHLD, waitpid's are useless */
3946 G.we_have_children = (childpid == 0);
3947 G.handled_SIGCHLD = i;
3948 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3953 dead = WIFEXITED(status) || WIFSIGNALED(status);
3956 if (WIFSTOPPED(status))
3957 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3958 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3959 if (WIFSIGNALED(status))
3960 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3961 childpid, WTERMSIG(status), WEXITSTATUS(status));
3962 if (WIFEXITED(status))
3963 debug_printf_jobs("pid %d exited, exitcode %d\n",
3964 childpid, WEXITSTATUS(status));
3966 /* Were we asked to wait for fg pipe? */
3968 for (i = 0; i < fg_pipe->num_cmds; i++) {
3969 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3970 if (fg_pipe->cmds[i].pid != childpid)
3973 fg_pipe->cmds[i].pid = 0;
3974 fg_pipe->alive_cmds--;
3975 if (i == fg_pipe->num_cmds - 1) {
3976 /* last process gives overall exitstatus */
3977 rcode = WEXITSTATUS(status);
3978 /* bash prints killer signal's name for *last*
3979 * process in pipe (prints just newline for SIGINT).
3980 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3982 if (WIFSIGNALED(status)) {
3983 int sig = WTERMSIG(status);
3984 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3985 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
3986 * Maybe we need to use sig | 128? */
3989 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3992 fg_pipe->cmds[i].is_stopped = 1;
3993 fg_pipe->stopped_cmds++;
3995 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3996 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3997 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3998 /* All processes in fg pipe have exited or stopped */
3999 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4000 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4001 * and "killall -STOP cat" */
4002 if (G_interactive_fd) {
4004 if (fg_pipe->alive_cmds)
4005 insert_bg_job(fg_pipe);
4009 if (!fg_pipe->alive_cmds)
4012 /* There are still running processes in the fg pipe */
4013 goto wait_more; /* do waitpid again */
4015 /* it wasnt fg_pipe, look for process in bg pipes */
4019 /* We asked to wait for bg or orphaned children */
4020 /* No need to remember exitcode in this case */
4021 for (pi = G.job_list; pi; pi = pi->next) {
4022 for (i = 0; i < pi->num_cmds; i++) {
4023 if (pi->cmds[i].pid == childpid)
4024 goto found_pi_and_prognum;
4027 /* Happens when shell is used as init process (init=/bin/sh) */
4028 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4029 continue; /* do waitpid again */
4031 found_pi_and_prognum:
4034 pi->cmds[i].pid = 0;
4036 if (!pi->alive_cmds) {
4037 if (G_interactive_fd)
4038 printf(JOB_STATUS_FORMAT, pi->jobid,
4039 "Done", pi->cmdtext);
4040 delete_finished_bg_job(pi);
4044 pi->cmds[i].is_stopped = 1;
4048 } /* while (waitpid succeeds)... */
4054 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4057 int rcode = checkjobs(fg_pipe);
4058 if (G_saved_tty_pgrp) {
4059 /* Job finished, move the shell to the foreground */
4060 p = getpgrp(); /* our process group id */
4061 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4062 tcsetpgrp(G_interactive_fd, p);
4068 /* Start all the jobs, but don't wait for anything to finish.
4071 * Return code is normally -1, when the caller has to wait for children
4072 * to finish to determine the exit status of the pipe. If the pipe
4073 * is a simple builtin command, however, the action is done by the
4074 * time run_pipe returns, and the exit code is provided as the
4077 * Returns -1 only if started some children. IOW: we have to
4078 * mask out retvals of builtins etc with 0xff!
4080 * The only case when we do not need to [v]fork is when the pipe
4081 * is single, non-backgrounded, non-subshell command. Examples:
4082 * cmd ; ... { list } ; ...
4083 * cmd && ... { list } && ...
4084 * cmd || ... { list } || ...
4085 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4086 * or (if SH_STANDALONE) an applet, and we can run the { list }
4087 * with run_list. If it isn't one of these, we fork and exec cmd.
4089 * Cases when we must fork:
4090 * non-single: cmd | cmd
4091 * backgrounded: cmd & { list } &
4092 * subshell: ( list ) [&]
4094 static NOINLINE int run_pipe(struct pipe *pi)
4096 static const char *const null_ptr = NULL;
4099 struct command *command;
4100 char **argv_expanded;
4103 /* it is not always needed, but we aim to smaller code */
4104 int squirrel[] = { -1, -1, -1 };
4107 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4110 IF_HUSH_JOB(pi->pgrp = -1;)
4111 pi->stopped_cmds = 0;
4112 command = &(pi->cmds[0]);
4113 argv_expanded = NULL;
4115 if (pi->num_cmds != 1
4116 || pi->followup == PIPE_BG
4117 || command->cmd_type == CMD_SUBSHELL
4124 debug_printf_exec(": group:%p argv:'%s'\n",
4125 command->group, command->argv ? command->argv[0] : "NONE");
4127 if (command->group) {
4128 #if ENABLE_HUSH_FUNCTIONS
4129 if (command->cmd_type == CMD_FUNCDEF) {
4130 /* "executing" func () { list } */
4131 struct function *funcp;
4133 funcp = new_function(command->argv[0]);
4134 /* funcp->name is already set to argv[0] */
4135 funcp->body = command->group;
4137 funcp->body_as_string = command->group_as_string;
4138 command->group_as_string = NULL;
4140 command->group = NULL;
4141 command->argv[0] = NULL;
4142 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4143 funcp->parent_cmd = command;
4144 command->child_func = funcp;
4146 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4148 return EXIT_SUCCESS;
4152 debug_printf("non-subshell group\n");
4153 rcode = 1; /* exitcode if redir failed */
4154 if (setup_redirects(command, squirrel) == 0) {
4155 debug_printf_exec(": run_list\n");
4156 rcode = run_list(command->group) & 0xff;
4158 restore_redirects(squirrel);
4159 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4161 debug_printf_exec("run_pipe: return %d\n", rcode);
4165 argv = command->argv ? command->argv : (char **) &null_ptr;
4167 const struct built_in_command *x;
4168 #if ENABLE_HUSH_FUNCTIONS
4169 const struct function *funcp;
4173 char **new_env = NULL;
4174 struct variable *old_vars = NULL;
4176 if (argv[command->assignment_cnt] == NULL) {
4177 /* Assignments, but no command */
4178 /* Ensure redirects take effect (that is, create files).
4179 * Try "a=t >file": */
4180 rcode = setup_redirects(command, squirrel);
4181 restore_redirects(squirrel);
4182 /* Set shell variables */
4184 p = expand_string_to_string(*argv);
4185 debug_printf_exec("set shell var:'%s'->'%s'\n",
4187 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4190 /* Redirect error sets $? to 1. Othervise,
4191 * if evaluating assignment value set $?, retain it.
4192 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4194 rcode = G.last_exitcode;
4195 /* Do we need to flag set_local_var() errors?
4196 * "assignment to readonly var" and "putenv error"
4198 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4200 debug_printf_exec("run_pipe: return %d\n", rcode);
4204 /* Expand the rest into (possibly) many strings each */
4206 #if ENABLE_HUSH_BASH_COMPAT
4207 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4208 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4211 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4212 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4213 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4218 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4221 /* if someone gives us an empty string: `cmd with empty output` */
4222 if (!argv_expanded[0]) {
4223 free(argv_expanded);
4225 return G.last_exitcode;
4228 x = find_builtin(argv_expanded[0]);
4229 #if ENABLE_HUSH_FUNCTIONS
4232 funcp = find_function(argv_expanded[0]);
4236 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4237 debug_printf("exec with redirects only\n");
4238 rcode = setup_redirects(command, NULL);
4239 goto clean_up_and_ret1;
4242 /* setup_redirects acts on file descriptors, not FILEs.
4243 * This is perfect for work that comes after exec().
4244 * Is it really safe for inline use? Experimentally,
4245 * things seem to work. */
4246 rcode = setup_redirects(command, squirrel);
4248 new_env = expand_assignments(argv, command->assignment_cnt);
4249 old_vars = set_vars_and_save_old(new_env);
4251 debug_printf_exec(": builtin '%s' '%s'...\n",
4252 x->b_cmd, argv_expanded[1]);
4253 rcode = x->b_function(argv_expanded) & 0xff;
4256 #if ENABLE_HUSH_FUNCTIONS
4258 # if ENABLE_HUSH_LOCAL
4259 struct variable **sv;
4260 sv = G.shadowed_vars_pp;
4261 G.shadowed_vars_pp = &old_vars;
4263 debug_printf_exec(": function '%s' '%s'...\n",
4264 funcp->name, argv_expanded[1]);
4265 rcode = run_function(funcp, argv_expanded) & 0xff;
4266 # if ENABLE_HUSH_LOCAL
4267 G.shadowed_vars_pp = sv;
4272 #if ENABLE_FEATURE_SH_STANDALONE
4275 restore_redirects(squirrel);
4276 unset_vars(new_env);
4279 free(argv_expanded);
4280 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4282 debug_printf_exec("run_pipe return %d\n", rcode);
4286 #if ENABLE_FEATURE_SH_STANDALONE
4287 i = find_applet_by_name(argv_expanded[0]);
4288 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4289 rcode = setup_redirects(command, squirrel);
4291 new_env = expand_assignments(argv, command->assignment_cnt);
4292 old_vars = set_vars_and_save_old(new_env);
4293 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4294 argv_expanded[0], argv_expanded[1]);
4295 rcode = run_nofork_applet(i, argv_expanded);
4297 goto clean_up_and_ret;
4300 /* It is neither builtin nor applet. We must fork. */
4304 /* NB: argv_expanded may already be created, and that
4305 * might include `cmd` runs! Do not rerun it! We *must*
4306 * use argv_expanded if it's non-NULL */
4308 /* Going to fork a child per each pipe member */
4312 for (i = 0; i < pi->num_cmds; i++) {
4313 struct fd_pair pipefds;
4315 volatile nommu_save_t nommu_save;
4316 nommu_save.new_env = NULL;
4317 nommu_save.old_vars = NULL;
4318 nommu_save.argv = NULL;
4319 nommu_save.argv_from_re_execing = NULL;
4321 command = &(pi->cmds[i]);
4322 if (command->argv) {
4323 debug_printf_exec(": pipe member '%s' '%s'...\n",
4324 command->argv[0], command->argv[1]);
4326 debug_printf_exec(": pipe member with no argv\n");
4329 /* pipes are inserted between pairs of commands */
4332 if ((i + 1) < pi->num_cmds)
4333 xpiped_pair(pipefds);
4335 command->pid = BB_MMU ? fork() : vfork();
4336 if (!command->pid) { /* child */
4338 disable_restore_tty_pgrp_on_exit();
4339 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4341 /* Every child adds itself to new process group
4342 * with pgid == pid_of_first_child_in_pipe */
4343 if (G.run_list_level == 1 && G_interactive_fd) {
4346 if (pgrp < 0) /* true for 1st process only */
4348 if (setpgid(0, pgrp) == 0
4349 && pi->followup != PIPE_BG
4350 && G_saved_tty_pgrp /* we have ctty */
4352 /* We do it in *every* child, not just first,
4354 tcsetpgrp(G_interactive_fd, pgrp);
4358 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4359 /* 1st cmd in backgrounded pipe
4360 * should have its stdin /dev/null'ed */
4362 if (open(bb_dev_null, O_RDONLY))
4363 xopen("/", O_RDONLY);
4365 xmove_fd(nextin, 0);
4367 xmove_fd(pipefds.wr, 1);
4370 /* Like bash, explicit redirects override pipes,
4371 * and the pipe fd is available for dup'ing. */
4372 if (setup_redirects(command, NULL))
4375 /* Restore default handlers just prior to exec */
4376 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4378 /* Stores to nommu_save list of env vars putenv'ed
4379 * (NOMMU, on MMU we don't need that) */
4380 /* cast away volatility... */
4381 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4382 /* pseudo_exec() does not return */
4385 /* parent or error */
4386 #if ENABLE_HUSH_FAST
4388 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4390 enable_restore_tty_pgrp_on_exit();
4392 /* Clean up after vforked child */
4393 free(nommu_save.argv);
4394 free(nommu_save.argv_from_re_execing);
4395 unset_vars(nommu_save.new_env);
4396 add_vars(nommu_save.old_vars);
4398 free(argv_expanded);
4399 argv_expanded = NULL;
4400 if (command->pid < 0) { /* [v]fork failed */
4401 /* Clearly indicate, was it fork or vfork */
4402 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4406 /* Second and next children need to know pid of first one */
4408 pi->pgrp = command->pid;
4414 if ((i + 1) < pi->num_cmds)
4416 /* Pass read (output) pipe end to next iteration */
4417 nextin = pipefds.rd;
4420 if (!pi->alive_cmds) {
4422 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4427 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4431 #ifndef debug_print_tree
4432 static void debug_print_tree(struct pipe *pi, int lvl)
4434 static const char *const PIPE[] = {
4440 static const char *RES[] = {
4441 [RES_NONE ] = "NONE" ,
4444 [RES_THEN ] = "THEN" ,
4445 [RES_ELIF ] = "ELIF" ,
4446 [RES_ELSE ] = "ELSE" ,
4449 # if ENABLE_HUSH_LOOPS
4450 [RES_FOR ] = "FOR" ,
4451 [RES_WHILE] = "WHILE",
4452 [RES_UNTIL] = "UNTIL",
4454 [RES_DONE ] = "DONE" ,
4456 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4459 # if ENABLE_HUSH_CASE
4460 [RES_CASE ] = "CASE" ,
4461 [RES_CASE_IN ] = "CASE_IN" ,
4462 [RES_MATCH] = "MATCH",
4463 [RES_CASE_BODY] = "CASE_BODY",
4464 [RES_ESAC ] = "ESAC" ,
4466 [RES_XXXX ] = "XXXX" ,
4467 [RES_SNTX ] = "SNTX" ,
4469 static const char *const CMDTYPE[] = {
4473 # if ENABLE_HUSH_FUNCTIONS
4482 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4483 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4485 while (prn < pi->num_cmds) {
4486 struct command *command = &pi->cmds[prn];
4487 char **argv = command->argv;
4489 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4491 command->assignment_cnt);
4492 if (command->group) {
4493 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4494 CMDTYPE[command->cmd_type],
4497 , " group_as_string:", command->group_as_string
4502 debug_print_tree(command->group, lvl+1);
4506 if (argv) while (*argv) {
4507 fprintf(stderr, " '%s'", *argv);
4510 fprintf(stderr, "\n");
4517 #endif /* debug_print_tree */
4519 /* NB: called by pseudo_exec, and therefore must not modify any
4520 * global data until exec/_exit (we can be a child after vfork!) */
4521 static int run_list(struct pipe *pi)
4523 #if ENABLE_HUSH_CASE
4524 char *case_word = NULL;
4526 #if ENABLE_HUSH_LOOPS
4527 struct pipe *loop_top = NULL;
4528 char **for_lcur = NULL;
4529 char **for_list = NULL;
4531 smallint last_followup;
4533 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4534 smalluint cond_code = 0;
4536 enum { cond_code = 0 };
4539 smallint rword; /* enum reserved_style */
4540 smallint last_rword; /* ditto */
4543 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4546 #if ENABLE_HUSH_LOOPS
4547 /* Check syntax for "for" */
4548 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4549 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4551 /* current word is FOR or IN (BOLD in comments below) */
4552 if (cpipe->next == NULL) {
4553 syntax_error("malformed for");
4555 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4558 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4559 if (cpipe->next->res_word == RES_DO)
4561 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4562 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4563 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4565 syntax_error("malformed for");
4567 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4573 /* Past this point, all code paths should jump to ret: label
4574 * in order to return, no direct "return" statements please.
4575 * This helps to ensure that no memory is leaked. */
4583 last_rword = RES_XXXX;
4585 last_followup = PIPE_SEQ;
4586 rcode = G.last_exitcode;
4588 /* Go through list of pipes, (maybe) executing them. */
4589 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4593 IF_HAS_KEYWORDS(rword = pi->res_word;)
4594 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4595 rword, cond_code, last_rword);
4596 #if ENABLE_HUSH_LOOPS
4597 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4598 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4600 /* start of a loop: remember where loop starts */
4605 /* Still in the same "if...", "then..." or "do..." branch? */
4606 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4607 if ((rcode == 0 && last_followup == PIPE_OR)
4608 || (rcode != 0 && last_followup == PIPE_AND)
4610 /* It is "<true> || CMD" or "<false> && CMD"
4611 * and we should not execute CMD */
4612 debug_printf_exec("skipped cmd because of || or &&\n");
4613 last_followup = pi->followup;
4617 last_followup = pi->followup;
4618 IF_HAS_KEYWORDS(last_rword = rword;)
4621 if (rword == RES_THEN) {
4622 /* if false; then ... fi has exitcode 0! */
4623 G.last_exitcode = rcode = EXIT_SUCCESS;
4624 /* "if <false> THEN cmd": skip cmd */
4628 if (rword == RES_ELSE || rword == RES_ELIF) {
4629 /* "if <true> then ... ELSE/ELIF cmd":
4630 * skip cmd and all following ones */
4635 #if ENABLE_HUSH_LOOPS
4636 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4638 /* first loop through for */
4640 static const char encoded_dollar_at[] ALIGN1 = {
4641 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4642 }; /* encoded representation of "$@" */
4643 static const char *const encoded_dollar_at_argv[] = {
4644 encoded_dollar_at, NULL
4645 }; /* argv list with one element: "$@" */
4648 vals = (char**)encoded_dollar_at_argv;
4649 if (pi->next->res_word == RES_IN) {
4650 /* if no variable values after "in" we skip "for" */
4651 if (!pi->next->cmds[0].argv) {
4652 G.last_exitcode = rcode = EXIT_SUCCESS;
4653 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4656 vals = pi->next->cmds[0].argv;
4657 } /* else: "for var; do..." -> assume "$@" list */
4658 /* create list of variable values */
4659 debug_print_strings("for_list made from", vals);
4660 for_list = expand_strvec_to_strvec(vals);
4661 for_lcur = for_list;
4662 debug_print_strings("for_list", for_list);
4665 /* "for" loop is over, clean up */
4671 /* Insert next value from for_lcur */
4672 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4673 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4676 if (rword == RES_IN) {
4677 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4679 if (rword == RES_DONE) {
4680 continue; /* "done" has no cmds too */
4683 #if ENABLE_HUSH_CASE
4684 if (rword == RES_CASE) {
4685 case_word = expand_strvec_to_string(pi->cmds->argv);
4688 if (rword == RES_MATCH) {
4691 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4693 /* all prev words didn't match, does this one match? */
4694 argv = pi->cmds->argv;
4696 char *pattern = expand_string_to_string(*argv);
4697 /* TODO: which FNM_xxx flags to use? */
4698 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4700 if (cond_code == 0) { /* match! we will execute this branch */
4701 free(case_word); /* make future "word)" stop */
4709 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4711 continue; /* not matched yet, skip this pipe */
4714 /* Just pressing <enter> in shell should check for jobs.
4715 * OTOH, in non-interactive shell this is useless
4716 * and only leads to extra job checks */
4717 if (pi->num_cmds == 0) {
4718 if (G_interactive_fd)
4719 goto check_jobs_and_continue;
4723 /* After analyzing all keywords and conditions, we decided
4724 * to execute this pipe. NB: have to do checkjobs(NULL)
4725 * after run_pipe to collect any background children,
4726 * even if list execution is to be stopped. */
4727 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4730 #if ENABLE_HUSH_LOOPS
4731 G.flag_break_continue = 0;
4733 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4735 /* We ran a builtin, function, or group.
4736 * rcode is already known
4737 * and we don't need to wait for anything. */
4738 G.last_exitcode = rcode;
4739 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4740 check_and_run_traps(0);
4741 #if ENABLE_HUSH_LOOPS
4742 /* Was it "break" or "continue"? */
4743 if (G.flag_break_continue) {
4744 smallint fbc = G.flag_break_continue;
4745 /* We might fall into outer *loop*,
4746 * don't want to break it too */
4748 G.depth_break_continue--;
4749 if (G.depth_break_continue == 0)
4750 G.flag_break_continue = 0;
4751 /* else: e.g. "continue 2" should *break* once, *then* continue */
4752 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4753 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4754 goto check_jobs_and_break;
4755 /* "continue": simulate end of loop */
4760 #if ENABLE_HUSH_FUNCTIONS
4761 if (G.flag_return_in_progress == 1) {
4762 /* same as "goto check_jobs_and_break" */
4767 } else if (pi->followup == PIPE_BG) {
4768 /* What does bash do with attempts to background builtins? */
4769 /* even bash 3.2 doesn't do that well with nested bg:
4770 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4771 * I'm NOT treating inner &'s as jobs */
4772 check_and_run_traps(0);
4774 if (G.run_list_level == 1)
4777 G.last_exitcode = rcode = EXIT_SUCCESS;
4778 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4781 if (G.run_list_level == 1 && G_interactive_fd) {
4782 /* Waits for completion, then fg's main shell */
4783 rcode = checkjobs_and_fg_shell(pi);
4784 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4785 check_and_run_traps(0);
4788 { /* This one just waits for completion */
4789 rcode = checkjobs(pi);
4790 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4791 check_and_run_traps(0);
4793 G.last_exitcode = rcode;
4797 /* Analyze how result affects subsequent commands */
4799 if (rword == RES_IF || rword == RES_ELIF)
4802 #if ENABLE_HUSH_LOOPS
4803 /* Beware of "while false; true; do ..."! */
4804 if (pi->next && pi->next->res_word == RES_DO) {
4805 if (rword == RES_WHILE) {
4807 /* "while false; do...done" - exitcode 0 */
4808 G.last_exitcode = rcode = EXIT_SUCCESS;
4809 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4810 goto check_jobs_and_break;
4813 if (rword == RES_UNTIL) {
4815 debug_printf_exec(": until expr is true: breaking\n");
4816 check_jobs_and_break:
4824 check_jobs_and_continue:
4831 #if ENABLE_HUSH_LOOPS
4836 #if ENABLE_HUSH_CASE
4840 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4844 /* Select which version we will use */
4845 static int run_and_free_list(struct pipe *pi)
4848 debug_printf_exec("run_and_free_list entered\n");
4850 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4851 rcode = run_list(pi);
4853 /* free_pipe_list has the side effect of clearing memory.
4854 * In the long run that function can be merged with run_list,
4855 * but doing that now would hobble the debugging effort. */
4857 debug_printf_exec("run_and_free_list return %d\n", rcode);
4862 static struct pipe *new_pipe(void)
4865 pi = xzalloc(sizeof(struct pipe));
4866 /*pi->followup = 0; - deliberately invalid value */
4867 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4871 /* Command (member of a pipe) is complete, or we start a new pipe
4872 * if ctx->command is NULL.
4873 * No errors possible here.
4875 static int done_command(struct parse_context *ctx)
4877 /* The command is really already in the pipe structure, so
4878 * advance the pipe counter and make a new, null command. */
4879 struct pipe *pi = ctx->pipe;
4880 struct command *command = ctx->command;
4883 if (IS_NULL_CMD(command)) {
4884 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4888 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4889 //debug_print_tree(ctx->list_head, 20);
4891 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4894 /* Only real trickiness here is that the uncommitted
4895 * command structure is not counted in pi->num_cmds. */
4896 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4897 ctx->command = command = &pi->cmds[pi->num_cmds];
4899 memset(command, 0, sizeof(*command));
4900 return pi->num_cmds; /* used only for 0/nonzero check */
4903 static void done_pipe(struct parse_context *ctx, pipe_style type)
4907 debug_printf_parse("done_pipe entered, followup %d\n", type);
4908 /* Close previous command */
4909 not_null = done_command(ctx);
4910 ctx->pipe->followup = type;
4912 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4913 ctx->ctx_inverted = 0;
4914 ctx->pipe->res_word = ctx->ctx_res_w;
4917 /* Without this check, even just <enter> on command line generates
4918 * tree of three NOPs (!). Which is harmless but annoying.
4919 * IOW: it is safe to do it unconditionally. */
4922 || ctx->ctx_res_w == RES_FI
4924 #if ENABLE_HUSH_LOOPS
4925 || ctx->ctx_res_w == RES_DONE
4926 || ctx->ctx_res_w == RES_FOR
4927 || ctx->ctx_res_w == RES_IN
4929 #if ENABLE_HUSH_CASE
4930 || ctx->ctx_res_w == RES_ESAC
4934 debug_printf_parse("done_pipe: adding new pipe: "
4935 "not_null:%d ctx->ctx_res_w:%d\n",
4936 not_null, ctx->ctx_res_w);
4938 ctx->pipe->next = new_p;
4940 /* RES_THEN, RES_DO etc are "sticky" -
4941 * they remain set for pipes inside if/while.
4942 * This is used to control execution.
4943 * RES_FOR and RES_IN are NOT sticky (needed to support
4944 * cases where variable or value happens to match a keyword):
4946 #if ENABLE_HUSH_LOOPS
4947 if (ctx->ctx_res_w == RES_FOR
4948 || ctx->ctx_res_w == RES_IN)
4949 ctx->ctx_res_w = RES_NONE;
4951 #if ENABLE_HUSH_CASE
4952 if (ctx->ctx_res_w == RES_MATCH)
4953 ctx->ctx_res_w = RES_CASE_BODY;
4954 if (ctx->ctx_res_w == RES_CASE)
4955 ctx->ctx_res_w = RES_CASE_IN;
4957 ctx->command = NULL; /* trick done_command below */
4958 /* Create the memory for command, roughly:
4959 * ctx->pipe->cmds = new struct command;
4960 * ctx->command = &ctx->pipe->cmds[0];
4963 //debug_print_tree(ctx->list_head, 10);
4965 debug_printf_parse("done_pipe return\n");
4968 static void initialize_context(struct parse_context *ctx)
4970 memset(ctx, 0, sizeof(*ctx));
4971 ctx->pipe = ctx->list_head = new_pipe();
4972 /* Create the memory for command, roughly:
4973 * ctx->pipe->cmds = new struct command;
4974 * ctx->command = &ctx->pipe->cmds[0];
4979 /* If a reserved word is found and processed, parse context is modified
4980 * and 1 is returned.
4983 struct reserved_combo {
4986 unsigned char assignment_flag;
4990 FLAG_END = (1 << RES_NONE ),
4992 FLAG_IF = (1 << RES_IF ),
4993 FLAG_THEN = (1 << RES_THEN ),
4994 FLAG_ELIF = (1 << RES_ELIF ),
4995 FLAG_ELSE = (1 << RES_ELSE ),
4996 FLAG_FI = (1 << RES_FI ),
4998 # if ENABLE_HUSH_LOOPS
4999 FLAG_FOR = (1 << RES_FOR ),
5000 FLAG_WHILE = (1 << RES_WHILE),
5001 FLAG_UNTIL = (1 << RES_UNTIL),
5002 FLAG_DO = (1 << RES_DO ),
5003 FLAG_DONE = (1 << RES_DONE ),
5004 FLAG_IN = (1 << RES_IN ),
5006 # if ENABLE_HUSH_CASE
5007 FLAG_MATCH = (1 << RES_MATCH),
5008 FLAG_ESAC = (1 << RES_ESAC ),
5010 FLAG_START = (1 << RES_XXXX ),
5013 static const struct reserved_combo* match_reserved_word(o_string *word)
5015 /* Mostly a list of accepted follow-up reserved words.
5016 * FLAG_END means we are done with the sequence, and are ready
5017 * to turn the compound list into a command.
5018 * FLAG_START means the word must start a new compound list.
5020 static const struct reserved_combo reserved_list[] = {
5022 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5023 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5024 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5025 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5026 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5027 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5029 # if ENABLE_HUSH_LOOPS
5030 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5031 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5032 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5033 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5034 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5035 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5037 # if ENABLE_HUSH_CASE
5038 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5039 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5042 const struct reserved_combo *r;
5044 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5045 if (strcmp(word->data, r->literal) == 0)
5050 /* Return 0: not a keyword, 1: keyword
5052 static int reserved_word(o_string *word, struct parse_context *ctx)
5054 # if ENABLE_HUSH_CASE
5055 static const struct reserved_combo reserved_match = {
5056 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5059 const struct reserved_combo *r;
5063 r = match_reserved_word(word);
5067 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5068 # if ENABLE_HUSH_CASE
5069 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5070 /* "case word IN ..." - IN part starts first MATCH part */
5071 r = &reserved_match;
5074 if (r->flag == 0) { /* '!' */
5075 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5076 syntax_error("! ! command");
5077 ctx->ctx_res_w = RES_SNTX;
5079 ctx->ctx_inverted = 1;
5082 if (r->flag & FLAG_START) {
5083 struct parse_context *old;
5085 old = xmalloc(sizeof(*old));
5086 debug_printf_parse("push stack %p\n", old);
5087 *old = *ctx; /* physical copy */
5088 initialize_context(ctx);
5090 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5091 syntax_error_at(word->data);
5092 ctx->ctx_res_w = RES_SNTX;
5095 /* "{...} fi" is ok. "{...} if" is not
5097 * if { echo foo; } then { echo bar; } fi */
5098 if (ctx->command->group)
5099 done_pipe(ctx, PIPE_SEQ);
5102 ctx->ctx_res_w = r->res;
5103 ctx->old_flag = r->flag;
5104 word->o_assignment = r->assignment_flag;
5106 if (ctx->old_flag & FLAG_END) {
5107 struct parse_context *old;
5109 done_pipe(ctx, PIPE_SEQ);
5110 debug_printf_parse("pop stack %p\n", ctx->stack);
5112 old->command->group = ctx->list_head;
5113 old->command->cmd_type = CMD_NORMAL;
5115 o_addstr(&old->as_string, ctx->as_string.data);
5116 o_free_unsafe(&ctx->as_string);
5117 old->command->group_as_string = xstrdup(old->as_string.data);
5118 debug_printf_parse("pop, remembering as:'%s'\n",
5119 old->command->group_as_string);
5121 *ctx = *old; /* physical copy */
5126 #endif /* HAS_KEYWORDS */
5128 /* Word is complete, look at it and update parsing context.
5129 * Normal return is 0. Syntax errors return 1.
5130 * Note: on return, word is reset, but not o_free'd!
5132 static int done_word(o_string *word, struct parse_context *ctx)
5134 struct command *command = ctx->command;
5136 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5137 if (word->length == 0 && word->o_quoted == 0) {
5138 debug_printf_parse("done_word return 0: true null, ignored\n");
5142 if (ctx->pending_redirect) {
5143 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5144 * only if run as "bash", not "sh" */
5145 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5147 * ...the word that follows the redirection operator
5148 * shall be subjected to tilde expansion, parameter expansion,
5149 * command substitution, arithmetic expansion, and quote
5150 * removal. Pathname expansion shall not be performed
5151 * on the word by a non-interactive shell; an interactive
5152 * shell may perform it, but shall do so only when
5153 * the expansion would result in one word."
5155 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5156 /* Cater for >\file case:
5157 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5158 * Same with heredocs:
5159 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5161 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5162 unbackslash(ctx->pending_redirect->rd_filename);
5163 /* Is it <<"HEREDOC"? */
5164 if (word->o_quoted) {
5165 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5168 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5169 ctx->pending_redirect = NULL;
5171 /* If this word wasn't an assignment, next ones definitely
5172 * can't be assignments. Even if they look like ones. */
5173 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5174 && word->o_assignment != WORD_IS_KEYWORD
5176 word->o_assignment = NOT_ASSIGNMENT;
5178 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5179 command->assignment_cnt++;
5180 word->o_assignment = MAYBE_ASSIGNMENT;
5184 # if ENABLE_HUSH_CASE
5185 if (ctx->ctx_dsemicolon
5186 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5188 /* already done when ctx_dsemicolon was set to 1: */
5189 /* ctx->ctx_res_w = RES_MATCH; */
5190 ctx->ctx_dsemicolon = 0;
5193 if (!command->argv /* if it's the first word... */
5194 # if ENABLE_HUSH_LOOPS
5195 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5196 && ctx->ctx_res_w != RES_IN
5198 # if ENABLE_HUSH_CASE
5199 && ctx->ctx_res_w != RES_CASE
5202 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5203 if (reserved_word(word, ctx)) {
5204 o_reset_to_empty_unquoted(word);
5205 debug_printf_parse("done_word return %d\n",
5206 (ctx->ctx_res_w == RES_SNTX));
5207 return (ctx->ctx_res_w == RES_SNTX);
5209 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5210 if (strcmp(word->data, "export") == 0
5211 # if ENABLE_HUSH_LOCAL
5212 || strcmp(word->data, "local") == 0
5215 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5218 # if ENABLE_HUSH_BASH_COMPAT
5219 if (strcmp(word->data, "[[") == 0) {
5220 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5226 if (command->group) {
5227 /* "{ echo foo; } echo bar" - bad */
5228 syntax_error_at(word->data);
5229 debug_printf_parse("done_word return 1: syntax error, "
5230 "groups and arglists don't mix\n");
5233 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5234 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5235 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5236 /* (otherwise it's known to be not empty and is already safe) */
5238 /* exclude "$@" - it can expand to no word despite "" */
5239 char *p = word->data;
5240 while (p[0] == SPECIAL_VAR_SYMBOL
5241 && (p[1] & 0x7f) == '@'
5242 && p[2] == SPECIAL_VAR_SYMBOL
5246 if (p == word->data || p[0] != '\0') {
5247 /* saw no "$@", or not only "$@" but some
5248 * real text is there too */
5249 /* insert "empty variable" reference, this makes
5250 * e.g. "", $empty"" etc to not disappear */
5251 o_addchr(word, SPECIAL_VAR_SYMBOL);
5252 o_addchr(word, SPECIAL_VAR_SYMBOL);
5255 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5256 debug_print_strings("word appended to argv", command->argv);
5259 #if ENABLE_HUSH_LOOPS
5260 if (ctx->ctx_res_w == RES_FOR) {
5262 || !is_well_formed_var_name(command->argv[0], '\0')
5264 /* bash says just "not a valid identifier" */
5265 syntax_error("not a valid identifier in for");
5268 /* Force FOR to have just one word (variable name) */
5269 /* NB: basically, this makes hush see "for v in ..."
5270 * syntax as if it is "for v; in ...". FOR and IN become
5271 * two pipe structs in parse tree. */
5272 done_pipe(ctx, PIPE_SEQ);
5275 #if ENABLE_HUSH_CASE
5276 /* Force CASE to have just one word */
5277 if (ctx->ctx_res_w == RES_CASE) {
5278 done_pipe(ctx, PIPE_SEQ);
5282 o_reset_to_empty_unquoted(word);
5284 debug_printf_parse("done_word return 0\n");
5289 /* Peek ahead in the input to find out if we have a "&n" construct,
5290 * as in "2>&1", that represents duplicating a file descriptor.
5292 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5293 * REDIRFD_SYNTAX_ERR if syntax error,
5294 * REDIRFD_TO_FILE if no & was seen,
5295 * or the number found.
5298 #define parse_redir_right_fd(as_string, input) \
5299 parse_redir_right_fd(input)
5301 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5307 return REDIRFD_TO_FILE;
5309 ch = i_getch(input); /* get the & */
5310 nommu_addchr(as_string, ch);
5313 ch = i_getch(input);
5314 nommu_addchr(as_string, ch);
5315 return REDIRFD_CLOSE;
5319 while (ch != EOF && isdigit(ch)) {
5320 d = d*10 + (ch-'0');
5322 ch = i_getch(input);
5323 nommu_addchr(as_string, ch);
5328 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5330 bb_error_msg("ambiguous redirect");
5331 return REDIRFD_SYNTAX_ERR;
5334 /* Return code is 0 normal, 1 if a syntax error is detected
5336 static int parse_redirect(struct parse_context *ctx,
5339 struct in_str *input)
5341 struct command *command = ctx->command;
5342 struct redir_struct *redir;
5343 struct redir_struct **redirp;
5346 dup_num = REDIRFD_TO_FILE;
5347 if (style != REDIRECT_HEREDOC) {
5348 /* Check for a '>&1' type redirect */
5349 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5350 if (dup_num == REDIRFD_SYNTAX_ERR)
5353 int ch = i_peek(input);
5354 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5355 if (dup_num) { /* <<-... */
5356 ch = i_getch(input);
5357 nommu_addchr(&ctx->as_string, ch);
5362 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5363 int ch = i_peek(input);
5365 /* >|FILE redirect ("clobbering" >).
5366 * Since we do not support "set -o noclobber" yet,
5367 * >| and > are the same for now. Just eat |.
5369 ch = i_getch(input);
5370 nommu_addchr(&ctx->as_string, ch);
5374 /* Create a new redir_struct and append it to the linked list */
5375 redirp = &command->redirects;
5376 while ((redir = *redirp) != NULL) {
5377 redirp = &(redir->next);
5379 *redirp = redir = xzalloc(sizeof(*redir));
5380 /* redir->next = NULL; */
5381 /* redir->rd_filename = NULL; */
5382 redir->rd_type = style;
5383 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5385 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5386 redir_table[style].descrip);
5388 redir->rd_dup = dup_num;
5389 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5390 /* Erik had a check here that the file descriptor in question
5391 * is legit; I postpone that to "run time"
5392 * A "-" representation of "close me" shows up as a -3 here */
5393 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5394 redir->rd_fd, redir->rd_dup);
5396 /* Set ctx->pending_redirect, so we know what to do at the
5397 * end of the next parsed word. */
5398 ctx->pending_redirect = redir;
5403 /* If a redirect is immediately preceded by a number, that number is
5404 * supposed to tell which file descriptor to redirect. This routine
5405 * looks for such preceding numbers. In an ideal world this routine
5406 * needs to handle all the following classes of redirects...
5407 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5408 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5409 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5410 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5412 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5414 * ... If n is quoted, the number shall not be recognized as part of
5415 * the redirection expression. For example:
5417 * writes the character 2 into file a"
5418 * We are getting it right by setting ->o_quoted on any \<char>
5420 * A -1 return means no valid number was found,
5421 * the caller should use the appropriate default for this redirection.
5423 static int redirect_opt_num(o_string *o)
5427 if (o->data == NULL)
5429 num = bb_strtou(o->data, NULL, 10);
5430 if (errno || num < 0)
5432 o_reset_to_empty_unquoted(o);
5437 #define fetch_till_str(as_string, input, word, skip_tabs) \
5438 fetch_till_str(input, word, skip_tabs)
5440 static char *fetch_till_str(o_string *as_string,
5441 struct in_str *input,
5445 o_string heredoc = NULL_O_STRING;
5451 ch = i_getch(input);
5452 nommu_addchr(as_string, ch);
5454 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5455 heredoc.data[past_EOL] = '\0';
5456 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5457 return heredoc.data;
5460 o_addchr(&heredoc, ch);
5461 past_EOL = heredoc.length;
5464 ch = i_getch(input);
5465 nommu_addchr(as_string, ch);
5466 } while (skip_tabs && ch == '\t');
5467 } while (ch == '\n');
5470 o_free_unsafe(&heredoc);
5473 o_addchr(&heredoc, ch);
5474 nommu_addchr(as_string, ch);
5478 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5479 * and load them all. There should be exactly heredoc_cnt of them.
5481 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5483 struct pipe *pi = ctx->list_head;
5485 while (pi && heredoc_cnt) {
5487 struct command *cmd = pi->cmds;
5489 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5491 cmd->argv ? cmd->argv[0] : "NONE");
5492 for (i = 0; i < pi->num_cmds; i++) {
5493 struct redir_struct *redir = cmd->redirects;
5495 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5496 i, cmd->argv ? cmd->argv[0] : "NONE");
5498 if (redir->rd_type == REDIRECT_HEREDOC) {
5501 redir->rd_type = REDIRECT_HEREDOC2;
5502 /* redir->rd_dup is (ab)used to indicate <<- */
5503 p = fetch_till_str(&ctx->as_string, input,
5504 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5506 syntax_error("unexpected EOF in here document");
5509 free(redir->rd_filename);
5510 redir->rd_filename = p;
5513 redir = redir->next;
5520 /* Should be 0. If it isn't, it's a parse error */
5522 bb_error_msg_and_die("heredoc BUG 2");
5528 #if ENABLE_HUSH_TICK
5529 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5534 char **to_free = NULL;
5538 pid = BB_MMU ? fork() : vfork();
5540 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5542 if (pid == 0) { /* child */
5543 disable_restore_tty_pgrp_on_exit();
5544 /* Process substitution is not considered to be usual
5545 * 'command execution'.
5546 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5553 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5554 close(channel[0]); /* NB: close _first_, then move fd! */
5555 xmove_fd(channel[1], 1);
5556 /* Prevent it from trying to handle ctrl-z etc */
5557 IF_HUSH_JOB(G.run_list_level = 1;)
5558 /* Awful hack for `trap` or $(trap).
5560 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5561 * contains an example where "trap" is executed in a subshell:
5563 * save_traps=$(trap)
5565 * eval "$save_traps"
5567 * Standard does not say that "trap" in subshell shall print
5568 * parent shell's traps. It only says that its output
5569 * must have suitable form, but then, in the above example
5570 * (which is not supposed to be normative), it implies that.
5572 * bash (and probably other shell) does implement it
5573 * (traps are reset to defaults, but "trap" still shows them),
5574 * but as a result, "trap" logic is hopelessly messed up:
5577 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5578 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5579 * # true | trap <--- trap is in subshell - no output (ditto)
5580 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5581 * trap -- 'echo Ho' SIGWINCH
5582 * # echo `(trap)` <--- in subshell in subshell - output
5583 * trap -- 'echo Ho' SIGWINCH
5584 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5585 * trap -- 'echo Ho' SIGWINCH
5587 * The rules when to forget and when to not forget traps
5588 * get really complex and nonsensical.
5590 * Our solution: ONLY bare $(trap) or `trap` is special.
5592 s = skip_whitespace(s);
5593 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5595 static const char *const argv[] = { NULL, NULL };
5596 builtin_trap((char**)argv);
5597 exit(0); /* not _exit() - we need to fflush */
5600 reset_traps_to_defaults();
5601 parse_and_run_string(s);
5602 _exit(G.last_exitcode);
5604 /* We re-execute after vfork on NOMMU. This makes this script safe:
5605 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5606 * huge=`cat BIG` # was blocking here forever
5609 re_execute_shell(&to_free,
5619 # if ENABLE_HUSH_FAST
5621 //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);
5623 enable_restore_tty_pgrp_on_exit();
5628 close_on_exec_on(channel[0]);
5629 return xfdopen_for_read(channel[0]);
5632 /* Return code is exit status of the process that is run. */
5633 static int process_command_subs(o_string *dest, const char *s)
5636 struct in_str pipe_str;
5638 int status, ch, eol_cnt;
5640 fp = generate_stream_from_string(s, &pid);
5642 /* Now send results of command back into original context */
5643 setup_file_in_str(&pipe_str, fp);
5645 while ((ch = i_getch(&pipe_str)) != EOF) {
5651 o_addchr(dest, '\n');
5654 o_addQchr(dest, ch);
5657 debug_printf("done reading from `cmd` pipe, closing it\n");
5659 /* We need to extract exitcode. Test case
5660 * "true; echo `sleep 1; false` $?"
5662 safe_waitpid(pid, &status, 0);
5663 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5664 return WEXITSTATUS(status);
5666 #endif /* ENABLE_HUSH_TICK */
5668 #if !ENABLE_HUSH_FUNCTIONS
5669 #define parse_group(dest, ctx, input, ch) \
5670 parse_group(ctx, input, ch)
5672 static int parse_group(o_string *dest, struct parse_context *ctx,
5673 struct in_str *input, int ch)
5675 /* dest contains characters seen prior to ( or {.
5676 * Typically it's empty, but for function defs,
5677 * it contains function name (without '()'). */
5678 struct pipe *pipe_list;
5680 struct command *command = ctx->command;
5682 debug_printf_parse("parse_group entered\n");
5683 #if ENABLE_HUSH_FUNCTIONS
5684 if (ch == '(' && !dest->o_quoted) {
5686 if (done_word(dest, ctx))
5689 goto skip; /* (... */
5690 if (command->argv[1]) { /* word word ... (... */
5691 syntax_error_unexpected_ch('(');
5694 /* it is "word(..." or "word (..." */
5696 ch = i_getch(input);
5697 while (ch == ' ' || ch == '\t');
5699 syntax_error_unexpected_ch(ch);
5702 nommu_addchr(&ctx->as_string, ch);
5704 ch = i_getch(input);
5705 while (ch == ' ' || ch == '\t' || ch == '\n');
5707 syntax_error_unexpected_ch(ch);
5710 nommu_addchr(&ctx->as_string, ch);
5711 command->cmd_type = CMD_FUNCDEF;
5716 #if 0 /* Prevented by caller */
5717 if (command->argv /* word [word]{... */
5718 || dest->length /* word{... */
5719 || dest->o_quoted /* ""{... */
5722 debug_printf_parse("parse_group return 1: "
5723 "syntax error, groups and arglists don't mix\n");
5728 #if ENABLE_HUSH_FUNCTIONS
5734 command->cmd_type = CMD_SUBSHELL;
5736 /* bash does not allow "{echo...", requires whitespace */
5737 ch = i_getch(input);
5738 if (ch != ' ' && ch != '\t' && ch != '\n') {
5739 syntax_error_unexpected_ch(ch);
5742 nommu_addchr(&ctx->as_string, ch);
5747 char *as_string = NULL;
5749 pipe_list = parse_stream(&as_string, input, endch);
5752 o_addstr(&ctx->as_string, as_string);
5754 /* empty ()/{} or parse error? */
5755 if (!pipe_list || pipe_list == ERR_PTR) {
5756 /* parse_stream already emitted error msg */
5760 debug_printf_parse("parse_group return 1: "
5761 "parse_stream returned %p\n", pipe_list);
5764 command->group = pipe_list;
5766 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5767 command->group_as_string = as_string;
5768 debug_printf_parse("end of group, remembering as:'%s'\n",
5769 command->group_as_string);
5772 debug_printf_parse("parse_group return 0\n");
5774 /* command remains "open", available for possible redirects */
5777 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5778 /* Subroutines for copying $(...) and `...` things */
5779 static void add_till_backquote(o_string *dest, struct in_str *input);
5781 static void add_till_single_quote(o_string *dest, struct in_str *input)
5784 int ch = i_getch(input);
5786 syntax_error_unterm_ch('\'');
5787 /*xfunc_die(); - redundant */
5794 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5795 static void add_till_double_quote(o_string *dest, struct in_str *input)
5798 int ch = i_getch(input);
5800 syntax_error_unterm_ch('"');
5801 /*xfunc_die(); - redundant */
5805 if (ch == '\\') { /* \x. Copy both chars. */
5807 ch = i_getch(input);
5811 add_till_backquote(dest, input);
5815 //if (ch == '$') ...
5818 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5820 * "Within the backquoted style of command substitution, backslash
5821 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5822 * The search for the matching backquote shall be satisfied by the first
5823 * backquote found without a preceding backslash; during this search,
5824 * if a non-escaped backquote is encountered within a shell comment,
5825 * a here-document, an embedded command substitution of the $(command)
5826 * form, or a quoted string, undefined results occur. A single-quoted
5827 * or double-quoted string that begins, but does not end, within the
5828 * "`...`" sequence produces undefined results."
5830 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5832 static void add_till_backquote(o_string *dest, struct in_str *input)
5835 int ch = i_getch(input);
5837 syntax_error_unterm_ch('`');
5838 /*xfunc_die(); - redundant */
5843 /* \x. Copy both chars unless it is \` */
5844 int ch2 = i_getch(input);
5846 syntax_error_unterm_ch('`');
5847 /*xfunc_die(); - redundant */
5849 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5856 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5857 * quoting and nested ()s.
5858 * "With the $(command) style of command substitution, all characters
5859 * following the open parenthesis to the matching closing parenthesis
5860 * constitute the command. Any valid shell script can be used for command,
5861 * except a script consisting solely of redirections which produces
5862 * unspecified results."
5864 * echo $(echo '(TEST)' BEST) (TEST) BEST
5865 * echo $(echo 'TEST)' BEST) TEST) BEST
5866 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5868 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5872 int ch = i_getch(input);
5874 syntax_error_unterm_ch(')');
5875 /*xfunc_die(); - redundant */
5883 if (i_peek(input) == ')') {
5891 add_till_single_quote(dest, input);
5896 add_till_double_quote(dest, input);
5901 /* \x. Copy verbatim. Important for \(, \) */
5902 ch = i_getch(input);
5904 syntax_error_unterm_ch(')');
5905 /*xfunc_die(); - redundant */
5912 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5914 /* Return code: 0 for OK, 1 for syntax error */
5916 #define handle_dollar(as_string, dest, input) \
5917 handle_dollar(dest, input)
5919 static int handle_dollar(o_string *as_string,
5921 struct in_str *input)
5923 int ch = i_peek(input); /* first character after the $ */
5924 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5926 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5928 ch = i_getch(input);
5929 nommu_addchr(as_string, ch);
5931 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5933 debug_printf_parse(": '%c'\n", ch);
5934 o_addchr(dest, ch | quote_mask);
5937 if (!isalnum(ch) && ch != '_')
5939 ch = i_getch(input);
5940 nommu_addchr(as_string, ch);
5942 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5943 } else if (isdigit(ch)) {
5945 ch = i_getch(input);
5946 nommu_addchr(as_string, ch);
5947 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5948 debug_printf_parse(": '%c'\n", ch);
5949 o_addchr(dest, ch | quote_mask);
5950 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5951 } else switch (ch) {
5953 case '!': /* last bg pid */
5954 case '?': /* last exit code */
5955 case '#': /* number of args */
5956 case '*': /* args */
5957 case '@': /* args */
5958 goto make_one_char_var;
5960 bool first_char, all_digits;
5961 bool in_expansion_param;
5963 ch = i_getch(input);
5964 nommu_addchr(as_string, ch);
5965 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5967 // TODO: need to handle "a=ab}; echo ${a%\}}"
5968 // and "a=abc; c=c; echo ${a%${c}}"
5969 in_expansion_param = false;
5973 ch = i_getch(input);
5974 nommu_addchr(as_string, ch);
5981 /* ${#var}: length of var contents */
5988 /* They're being verbose and doing ${?} */
5989 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5993 if (!in_expansion_param
5994 && ( (all_digits && !isdigit(ch)) /* met non-digit: 123w */
5995 || (!all_digits && !isalnum(ch) && ch != '_') /* met non-name char: abc% */
5998 /* handle parameter expansions
5999 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6001 if (first_char /* bad (empty var name): "${%..." */
6002 || !strchr("%#:-=+?", ch) /* bad: "${var<bad_char>..." */
6004 syntax_error_unterm_str("${name}");
6005 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
6008 in_expansion_param = true;
6011 debug_printf_parse(": '%c'\n", ch);
6012 o_addchr(dest, ch | quote_mask);
6016 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6019 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6024 ch = i_getch(input);
6025 nommu_addchr(as_string, ch);
6026 # if ENABLE_SH_MATH_SUPPORT
6027 if (i_peek(input) == '(') {
6028 ch = i_getch(input);
6029 nommu_addchr(as_string, ch);
6030 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6031 o_addchr(dest, /*quote_mask |*/ '+');
6035 add_till_closing_paren(dest, input, true);
6038 o_addstr(as_string, dest->data + pos);
6039 o_addchr(as_string, ')');
6040 o_addchr(as_string, ')');
6043 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6047 # if ENABLE_HUSH_TICK
6048 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6049 o_addchr(dest, quote_mask | '`');
6053 add_till_closing_paren(dest, input, false);
6056 o_addstr(as_string, dest->data + pos);
6057 o_addchr(as_string, ')');
6060 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6066 ch = i_getch(input);
6067 nommu_addchr(as_string, ch);
6069 if (isalnum(ch)) { /* it's $_name or $_123 */
6074 /* TODO: $_ and $-: */
6075 /* $_ Shell or shell script name; or last argument of last command
6076 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6077 * but in command's env, set to full pathname used to invoke it */
6078 /* $- Option flags set by set builtin or shell options (-i etc) */
6080 o_addQchr(dest, '$');
6082 debug_printf_parse("handle_dollar return 0\n");
6087 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6088 parse_stream_dquoted(dest, input, dquote_end)
6090 static int parse_stream_dquoted(o_string *as_string,
6092 struct in_str *input,
6099 ch = i_getch(input);
6101 nommu_addchr(as_string, ch);
6102 if (ch == dquote_end) { /* may be only '"' or EOF */
6103 if (dest->o_assignment == NOT_ASSIGNMENT)
6104 dest->o_escape ^= 1;
6105 debug_printf_parse("parse_stream_dquoted return 0\n");
6108 /* note: can't move it above ch == dquote_end check! */
6110 syntax_error_unterm_ch('"');
6111 /*xfunc_die(); - redundant */
6115 next = i_peek(input);
6117 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6118 ch, ch, dest->o_escape);
6121 syntax_error("\\<eof>");
6125 * "The backslash retains its special meaning [in "..."]
6126 * only when followed by one of the following characters:
6127 * $, `, ", \, or <newline>. A double quote may be quoted
6128 * within double quotes by preceding it with a backslash."
6130 if (strchr("$`\"\\\n", next) != NULL) {
6131 ch = i_getch(input);
6133 o_addqchr(dest, ch);
6134 nommu_addchr(as_string, ch);
6137 o_addqchr(dest, '\\');
6138 nommu_addchr(as_string, '\\');
6143 if (handle_dollar(as_string, dest, input) != 0) {
6144 debug_printf_parse("parse_stream_dquoted return 1: "
6145 "handle_dollar returned non-0\n");
6150 #if ENABLE_HUSH_TICK
6152 //int pos = dest->length;
6153 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6154 o_addchr(dest, 0x80 | '`');
6155 add_till_backquote(dest, input);
6156 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6157 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6161 o_addQchr(dest, ch);
6163 && (dest->o_assignment == MAYBE_ASSIGNMENT
6164 || dest->o_assignment == WORD_IS_KEYWORD)
6165 && is_well_formed_var_name(dest->data, '=')
6167 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6173 * Scan input until EOF or end_trigger char.
6174 * Return a list of pipes to execute, or NULL on EOF
6175 * or if end_trigger character is met.
6176 * On syntax error, exit is shell is not interactive,
6177 * reset parsing machinery and start parsing anew,
6178 * or return ERR_PTR.
6180 static struct pipe *parse_stream(char **pstring,
6181 struct in_str *input,
6184 struct parse_context ctx;
6185 o_string dest = NULL_O_STRING;
6189 /* Double-quote state is handled in the state variable is_in_dquote.
6190 * A single-quote triggers a bypass of the main loop until its mate is
6191 * found. When recursing, quote state is passed in via dest->o_escape.
6193 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6194 end_trigger ? end_trigger : 'X');
6197 /* If very first arg is "" or '', dest.data may end up NULL.
6198 * Preventing this: */
6199 o_addchr(&dest, '\0');
6202 G.ifs = get_local_var_value("IFS");
6207 #if ENABLE_HUSH_INTERACTIVE
6208 input->promptmode = 0; /* PS1 */
6210 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6211 initialize_context(&ctx);
6216 const char *is_special;
6220 redir_type redir_style;
6223 /* dest.o_quoted = 1; - already is (see below) */
6224 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6227 /* We reached closing '"' */
6230 ch = i_getch(input);
6231 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6232 ch, ch, dest.o_escape);
6237 syntax_error_unterm_str("here document");
6240 /* end_trigger == '}' case errors out earlier,
6241 * checking only ')' */
6242 if (end_trigger == ')') {
6243 syntax_error_unterm_ch('('); /* exits */
6244 /* goto parse_error; */
6247 if (done_word(&dest, &ctx)) {
6251 done_pipe(&ctx, PIPE_SEQ);
6253 /* If we got nothing... */
6254 /* (this makes bare "&" cmd a no-op.
6255 * bash says: "syntax error near unexpected token '&'") */
6256 if (pi->num_cmds == 0
6257 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6263 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6265 *pstring = ctx.as_string.data;
6267 o_free_unsafe(&ctx.as_string);
6270 debug_printf_parse("parse_stream return %p\n", pi);
6273 nommu_addchr(&ctx.as_string, ch);
6277 next = i_peek(input);
6279 is_special = "{}<>;&|()#'" /* special outside of "str" */
6280 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6281 /* Are { and } special here? */
6282 if (ctx.command->argv /* word [word]{... - non-special */
6283 || dest.length /* word{... - non-special */
6284 || dest.o_quoted /* ""{... - non-special */
6285 || (next != ';' /* }; - special */
6286 && next != ')' /* }) - special */
6287 && next != '&' /* }& and }&& ... - special */
6288 && next != '|' /* }|| ... - special */
6289 && !strchr(G.ifs, next) /* {word - non-special */
6292 /* They are not special, skip "{}" */
6295 is_special = strchr(is_special, ch);
6296 is_ifs = strchr(G.ifs, ch);
6298 if (!is_special && !is_ifs) { /* ordinary char */
6300 o_addQchr(&dest, ch);
6301 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6302 || dest.o_assignment == WORD_IS_KEYWORD)
6304 && is_well_formed_var_name(dest.data, '=')
6306 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6312 if (done_word(&dest, &ctx)) {
6316 #if ENABLE_HUSH_CASE
6317 /* "case ... in <newline> word) ..." -
6318 * newlines are ignored (but ';' wouldn't be) */
6319 if (ctx.command->argv == NULL
6320 && ctx.ctx_res_w == RES_MATCH
6325 /* Treat newline as a command separator. */
6326 done_pipe(&ctx, PIPE_SEQ);
6327 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6329 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6334 dest.o_assignment = MAYBE_ASSIGNMENT;
6336 /* note: if (is_ifs) continue;
6337 * will still trigger for us */
6341 /* "cmd}" or "cmd }..." without semicolon or &:
6342 * } is an ordinary char in this case, even inside { cmd; }
6343 * Pathological example: { ""}; } should exec "}" cmd
6346 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6347 || dest.length != 0 /* word} */
6348 || dest.o_quoted /* ""} */
6352 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6353 goto skip_end_trigger;
6354 /* else: } does terminate a group */
6357 if (end_trigger && end_trigger == ch
6358 && (ch != ';' || heredoc_cnt == 0)
6359 #if ENABLE_HUSH_CASE
6361 || ctx.ctx_res_w != RES_MATCH
6362 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6367 /* This is technically valid:
6368 * { cat <<HERE; }; echo Ok
6372 * but we don't support this.
6373 * We require heredoc to be in enclosing {}/(),
6376 syntax_error_unterm_str("here document");
6379 if (done_word(&dest, &ctx)) {
6382 done_pipe(&ctx, PIPE_SEQ);
6383 dest.o_assignment = MAYBE_ASSIGNMENT;
6384 /* Do we sit outside of any if's, loops or case's? */
6386 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6390 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6392 *pstring = ctx.as_string.data;
6394 o_free_unsafe(&ctx.as_string);
6397 debug_printf_parse("parse_stream return %p: "
6398 "end_trigger char found\n",
6400 return ctx.list_head;
6407 /* Catch <, > before deciding whether this word is
6408 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6411 redir_fd = redirect_opt_num(&dest);
6412 if (done_word(&dest, &ctx)) {
6415 redir_style = REDIRECT_OVERWRITE;
6417 redir_style = REDIRECT_APPEND;
6418 ch = i_getch(input);
6419 nommu_addchr(&ctx.as_string, ch);
6422 else if (next == '(') {
6423 syntax_error(">(process) not supported");
6427 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6429 continue; /* back to top of while (1) */
6431 redir_fd = redirect_opt_num(&dest);
6432 if (done_word(&dest, &ctx)) {
6435 redir_style = REDIRECT_INPUT;
6437 redir_style = REDIRECT_HEREDOC;
6439 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6440 ch = i_getch(input);
6441 nommu_addchr(&ctx.as_string, ch);
6442 } else if (next == '>') {
6443 redir_style = REDIRECT_IO;
6444 ch = i_getch(input);
6445 nommu_addchr(&ctx.as_string, ch);
6448 else if (next == '(') {
6449 syntax_error("<(process) not supported");
6453 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6455 continue; /* back to top of while (1) */
6458 if (dest.o_assignment == MAYBE_ASSIGNMENT
6459 /* check that we are not in word in "a=1 2>word b=1": */
6460 && !ctx.pending_redirect
6462 /* ch is a special char and thus this word
6463 * cannot be an assignment */
6464 dest.o_assignment = NOT_ASSIGNMENT;
6467 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6471 if (dest.length == 0) {
6474 if (ch == EOF || ch == '\n')
6477 /* note: we do not add it to &ctx.as_string */
6479 nommu_addchr(&ctx.as_string, '\n');
6481 o_addQchr(&dest, ch);
6486 syntax_error("\\<eof>");
6489 ch = i_getch(input);
6491 o_addchr(&dest, '\\');
6492 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6493 o_addchr(&dest, ch);
6494 nommu_addchr(&ctx.as_string, ch);
6495 /* Example: echo Hello \2>file
6496 * we need to know that word 2 is quoted */
6501 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6502 ctx.as_string.data[--ctx.as_string.length] = '\0';
6507 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6508 debug_printf_parse("parse_stream parse error: "
6509 "handle_dollar returned non-0\n");
6516 ch = i_getch(input);
6518 syntax_error_unterm_ch('\'');
6519 /*xfunc_die(); - redundant */
6521 nommu_addchr(&ctx.as_string, ch);
6524 o_addqchr(&dest, ch);
6529 is_in_dquote ^= 1; /* invert */
6530 if (dest.o_assignment == NOT_ASSIGNMENT)
6533 #if ENABLE_HUSH_TICK
6538 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6539 o_addchr(&dest, '`');
6543 add_till_backquote(&dest, input);
6545 o_addstr(&ctx.as_string, dest.data + pos);
6546 o_addchr(&ctx.as_string, '`');
6548 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6549 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6554 #if ENABLE_HUSH_CASE
6557 if (done_word(&dest, &ctx)) {
6560 done_pipe(&ctx, PIPE_SEQ);
6561 #if ENABLE_HUSH_CASE
6562 /* Eat multiple semicolons, detect
6563 * whether it means something special */
6568 ch = i_getch(input);
6569 nommu_addchr(&ctx.as_string, ch);
6570 if (ctx.ctx_res_w == RES_CASE_BODY) {
6571 ctx.ctx_dsemicolon = 1;
6572 ctx.ctx_res_w = RES_MATCH;
6578 /* We just finished a cmd. New one may start
6579 * with an assignment */
6580 dest.o_assignment = MAYBE_ASSIGNMENT;
6583 if (done_word(&dest, &ctx)) {
6587 ch = i_getch(input);
6588 nommu_addchr(&ctx.as_string, ch);
6589 done_pipe(&ctx, PIPE_AND);
6591 done_pipe(&ctx, PIPE_BG);
6595 if (done_word(&dest, &ctx)) {
6598 #if ENABLE_HUSH_CASE
6599 if (ctx.ctx_res_w == RES_MATCH)
6600 break; /* we are in case's "word | word)" */
6602 if (next == '|') { /* || */
6603 ch = i_getch(input);
6604 nommu_addchr(&ctx.as_string, ch);
6605 done_pipe(&ctx, PIPE_OR);
6607 /* we could pick up a file descriptor choice here
6608 * with redirect_opt_num(), but bash doesn't do it.
6609 * "echo foo 2| cat" yields "foo 2". */
6612 o_reset_to_empty_unquoted(&ctx.as_string);
6617 #if ENABLE_HUSH_CASE
6618 /* "case... in [(]word)..." - skip '(' */
6619 if (ctx.ctx_res_w == RES_MATCH
6620 && ctx.command->argv == NULL /* not (word|(... */
6621 && dest.length == 0 /* not word(... */
6622 && dest.o_quoted == 0 /* not ""(... */
6628 if (parse_group(&dest, &ctx, input, ch) != 0) {
6633 #if ENABLE_HUSH_CASE
6634 if (ctx.ctx_res_w == RES_MATCH)
6638 /* proper use of this character is caught by end_trigger:
6639 * if we see {, we call parse_group(..., end_trigger='}')
6640 * and it will match } earlier (not here). */
6641 syntax_error_unexpected_ch(ch);
6645 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6651 struct parse_context *pctx;
6652 IF_HAS_KEYWORDS(struct parse_context *p2;)
6654 /* Clean up allocated tree.
6655 * Sample for finding leaks on syntax error recovery path.
6656 * Run it from interactive shell, watch pmap `pidof hush`.
6657 * while if false; then false; fi; do break; fi
6658 * Samples to catch leaks at execution:
6659 * while if (true | {true;}); then echo ok; fi; do break; done
6660 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6664 /* Update pipe/command counts,
6665 * otherwise freeing may miss some */
6666 done_pipe(pctx, PIPE_SEQ);
6667 debug_printf_clean("freeing list %p from ctx %p\n",
6668 pctx->list_head, pctx);
6669 debug_print_tree(pctx->list_head, 0);
6670 free_pipe_list(pctx->list_head);
6671 debug_printf_clean("freed list %p\n", pctx->list_head);
6673 o_free_unsafe(&pctx->as_string);
6675 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6679 IF_HAS_KEYWORDS(pctx = p2;)
6680 } while (HAS_KEYWORDS && pctx);
6681 /* Free text, clear all dest fields */
6683 /* If we are not in top-level parse, we return,
6684 * our caller will propagate error.
6686 if (end_trigger != ';') {
6694 /* Discard cached input, force prompt */
6696 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6701 /* Executing from string: eval, sh -c '...'
6702 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6703 * end_trigger controls how often we stop parsing
6704 * NUL: parse all, execute, return
6705 * ';': parse till ';' or newline, execute, repeat till EOF
6707 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6709 /* Why we need empty flag?
6710 * An obscure corner case "false; ``; echo $?":
6711 * empty command in `` should still set $? to 0.
6712 * But we can't just set $? to 0 at the start,
6713 * this breaks "false; echo `echo $?`" case.
6717 struct pipe *pipe_list;
6719 pipe_list = parse_stream(NULL, inp, end_trigger);
6720 if (!pipe_list) { /* EOF */
6722 G.last_exitcode = 0;
6725 debug_print_tree(pipe_list, 0);
6726 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6727 run_and_free_list(pipe_list);
6732 static void parse_and_run_string(const char *s)
6734 struct in_str input;
6735 setup_string_in_str(&input, s);
6736 parse_and_run_stream(&input, '\0');
6739 static void parse_and_run_file(FILE *f)
6741 struct in_str input;
6742 setup_file_in_str(&input, f);
6743 parse_and_run_stream(&input, ';');
6746 /* Called a few times only (or even once if "sh -c") */
6747 static void init_sigmasks(void)
6751 sigset_t old_blocked_set;
6753 if (!G.inherited_set_is_saved) {
6754 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6755 G.inherited_set = G.blocked_set;
6757 old_blocked_set = G.blocked_set;
6759 mask = (1 << SIGQUIT);
6760 if (G_interactive_fd) {
6761 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6762 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6763 mask |= SPECIAL_JOB_SIGS;
6765 G.non_DFL_mask = mask;
6770 sigaddset(&G.blocked_set, sig);
6774 sigdelset(&G.blocked_set, SIGCHLD);
6776 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6777 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6779 /* POSIX allows shell to re-enable SIGCHLD
6780 * even if it was SIG_IGN on entry */
6781 #if ENABLE_HUSH_FAST
6782 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6783 if (!G.inherited_set_is_saved)
6784 signal(SIGCHLD, SIGCHLD_handler);
6786 if (!G.inherited_set_is_saved)
6787 signal(SIGCHLD, SIG_DFL);
6790 G.inherited_set_is_saved = 1;
6795 static void maybe_set_to_sigexit(int sig)
6797 void (*handler)(int);
6798 /* non_DFL_mask'ed signals are, well, masked,
6799 * no need to set handler for them.
6801 if (!((G.non_DFL_mask >> sig) & 1)) {
6802 handler = signal(sig, sigexit);
6803 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6804 signal(sig, handler);
6807 /* Set handlers to restore tty pgrp and exit */
6808 static void set_fatal_handlers(void)
6810 /* We _must_ restore tty pgrp on fatal signals */
6812 maybe_set_to_sigexit(SIGILL );
6813 maybe_set_to_sigexit(SIGFPE );
6814 maybe_set_to_sigexit(SIGBUS );
6815 maybe_set_to_sigexit(SIGSEGV);
6816 maybe_set_to_sigexit(SIGTRAP);
6817 } /* else: hush is perfect. what SEGV? */
6818 maybe_set_to_sigexit(SIGABRT);
6819 /* bash 3.2 seems to handle these just like 'fatal' ones */
6820 maybe_set_to_sigexit(SIGPIPE);
6821 maybe_set_to_sigexit(SIGALRM);
6822 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6823 * if we aren't interactive... but in this case
6824 * we never want to restore pgrp on exit, and this fn is not called */
6825 /*maybe_set_to_sigexit(SIGHUP );*/
6826 /*maybe_set_to_sigexit(SIGTERM);*/
6827 /*maybe_set_to_sigexit(SIGINT );*/
6831 static int set_mode(const char cstate, const char mode)
6833 int state = (cstate == '-' ? 1 : 0);
6835 case 'n': G.fake_mode = state; break;
6836 case 'x': /*G.debug_mode = state;*/ break;
6837 default: return EXIT_FAILURE;
6839 return EXIT_SUCCESS;
6842 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6843 int hush_main(int argc, char **argv)
6845 static const struct variable const_shell_ver = {
6847 .varstr = (char*)hush_version_str,
6848 .max_len = 1, /* 0 can provoke free(name) */
6853 unsigned builtin_argc;
6855 struct variable *cur_var;
6858 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6859 G.last_exitcode = EXIT_SUCCESS;
6861 G.argv0_for_re_execing = argv[0];
6863 /* Deal with HUSH_VERSION */
6864 G.shell_ver = const_shell_ver; /* copying struct here */
6865 G.top_var = &G.shell_ver;
6866 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6867 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6868 /* Initialize our shell local variables with the values
6869 * currently living in the environment */
6870 cur_var = G.top_var;
6873 char *value = strchr(*e, '=');
6874 if (value) { /* paranoia */
6875 cur_var->next = xzalloc(sizeof(*cur_var));
6876 cur_var = cur_var->next;
6877 cur_var->varstr = *e;
6878 cur_var->max_len = strlen(*e);
6879 cur_var->flg_export = 1;
6883 /* reinstate HUSH_VERSION */
6884 debug_printf_env("putenv '%s'\n", hush_version_str);
6885 putenv((char *)hush_version_str);
6888 set_pwd_var(/*exp:*/ 1);
6889 /* bash also exports SHLVL and _,
6890 * and sets (but doesn't export) the following variables:
6892 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6893 * BASH_VERSION='3.2.0(1)-release'
6895 * MACHTYPE=i386-pc-linux-gnu
6897 * HOSTNAME=<xxxxxxxxxx>
6898 * PPID=<NNNNN> - we also do it elsewhere
6909 * PIPESTATUS=([0]="0")
6910 * HISTFILE=/<xxx>/.bash_history
6914 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6916 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6926 #if ENABLE_FEATURE_EDITING
6927 G.line_input_state = new_line_input_t(FOR_SHELL);
6929 G.global_argc = argc;
6930 G.global_argv = argv;
6931 /* Initialize some more globals to non-zero values */
6932 cmdedit_update_prompt();
6934 if (setjmp(die_jmp)) {
6935 /* xfunc has failed! die die die */
6936 /* no EXIT traps, this is an escape hatch! */
6938 hush_exit(xfunc_error_retval);
6941 /* Shell is non-interactive at first. We need to call
6942 * init_sigmasks() if we are going to execute "sh <script>",
6943 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6944 * If we later decide that we are interactive, we run init_sigmasks()
6945 * in order to intercept (more) signals.
6949 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6952 opt = getopt(argc, argv, "+c:xins"
6955 # if ENABLE_HUSH_FUNCTIONS
6965 * sh ... -c 'script'
6966 * sh ... -c 'script' ARG0 [ARG1...]
6967 * On NOMMU, if builtin_argc != 0,
6968 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
6969 * "" needs to be replaced with NULL
6970 * and BARGV vector fed to builtin function.
6971 * Note: the form without ARG0 never happens:
6972 * sh ... -c 'builtin' BARGV... ""
6975 G.root_pid = getpid();
6976 G.root_ppid = getppid();
6978 G.global_argv = argv + optind;
6979 G.global_argc = argc - optind;
6981 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6982 const struct built_in_command *x;
6985 x = find_builtin(optarg);
6986 if (x) { /* paranoia */
6987 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6988 G.global_argv += builtin_argc;
6989 G.global_argv[-1] = NULL; /* replace "" */
6990 G.last_exitcode = x->b_function(argv + optind - 1);
6994 if (!G.global_argv[0]) {
6995 /* -c 'script' (no params): prevent empty $0 */
6996 G.global_argv--; /* points to argv[i] of 'script' */
6997 G.global_argv[0] = argv[0];
6999 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7001 parse_and_run_string(optarg);
7004 /* Well, we cannot just declare interactiveness,
7005 * we have to have some stuff (ctty, etc) */
7006 /* G_interactive_fd++; */
7009 /* "-s" means "read from stdin", but this is how we always
7010 * operate, so simply do nothing here. */
7013 case '<': /* "big heredoc" support */
7014 full_write(STDOUT_FILENO, optarg, strlen(optarg));
7017 unsigned long long empty_trap_mask;
7019 G.root_pid = bb_strtou(optarg, &optarg, 16);
7021 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7023 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7025 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7027 builtin_argc = bb_strtou(optarg, &optarg, 16);
7029 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7030 if (empty_trap_mask != 0) {
7033 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7034 for (sig = 1; sig < NSIG; sig++) {
7035 if (empty_trap_mask & (1LL << sig)) {
7036 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7037 sigaddset(&G.blocked_set, sig);
7040 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7042 # if ENABLE_HUSH_LOOPS
7044 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7050 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7052 # if ENABLE_HUSH_FUNCTIONS
7054 struct function *funcp = new_function(optarg);
7055 /* funcp->name is already set to optarg */
7056 /* funcp->body is set to NULL. It's a special case. */
7057 funcp->body_as_string = argv[optind];
7065 if (!set_mode('-', opt))
7069 fprintf(stderr, "Usage: sh [FILE]...\n"
7070 " or: sh -c command [args]...\n\n");
7076 } /* option parsing loop */
7079 G.root_pid = getpid();
7080 G.root_ppid = getppid();
7083 /* If we are login shell... */
7084 if (argv[0] && argv[0][0] == '-') {
7086 debug_printf("sourcing /etc/profile\n");
7087 input = fopen_for_read("/etc/profile");
7088 if (input != NULL) {
7089 close_on_exec_on(fileno(input));
7091 parse_and_run_file(input);
7094 /* bash: after sourcing /etc/profile,
7095 * tries to source (in the given order):
7096 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7097 * stopping on first found. --noprofile turns this off.
7098 * bash also sources ~/.bash_logout on exit.
7099 * If called as sh, skips .bash_XXX files.
7106 * "bash <script>" (which is never interactive (unless -i?))
7107 * sources $BASH_ENV here (without scanning $PATH).
7108 * If called as sh, does the same but with $ENV.
7110 debug_printf("running script '%s'\n", argv[optind]);
7111 G.global_argv = argv + optind;
7112 G.global_argc = argc - optind;
7113 input = xfopen_for_read(argv[optind]);
7114 close_on_exec_on(fileno(input));
7116 parse_and_run_file(input);
7117 #if ENABLE_FEATURE_CLEAN_UP
7123 /* Up to here, shell was non-interactive. Now it may become one.
7124 * NB: don't forget to (re)run init_sigmasks() as needed.
7127 /* A shell is interactive if the '-i' flag was given,
7128 * or if all of the following conditions are met:
7130 * no arguments remaining or the -s flag given
7131 * standard input is a terminal
7132 * standard output is a terminal
7133 * Refer to Posix.2, the description of the 'sh' utility.
7136 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7137 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7138 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7139 if (G_saved_tty_pgrp < 0)
7140 G_saved_tty_pgrp = 0;
7142 /* try to dup stdin to high fd#, >= 255 */
7143 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7144 if (G_interactive_fd < 0) {
7145 /* try to dup to any fd */
7146 G_interactive_fd = dup(STDIN_FILENO);
7147 if (G_interactive_fd < 0) {
7149 G_interactive_fd = 0;
7150 G_saved_tty_pgrp = 0;
7153 // TODO: track & disallow any attempts of user
7154 // to (inadvertently) close/redirect G_interactive_fd
7156 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7157 if (G_interactive_fd) {
7158 close_on_exec_on(G_interactive_fd);
7160 if (G_saved_tty_pgrp) {
7161 /* If we were run as 'hush &', sleep until we are
7162 * in the foreground (tty pgrp == our pgrp).
7163 * If we get started under a job aware app (like bash),
7164 * make sure we are now in charge so we don't fight over
7165 * who gets the foreground */
7167 pid_t shell_pgrp = getpgrp();
7168 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7169 if (G_saved_tty_pgrp == shell_pgrp)
7171 /* send TTIN to ourself (should stop us) */
7172 kill(- shell_pgrp, SIGTTIN);
7176 /* Block some signals */
7179 if (G_saved_tty_pgrp) {
7180 /* Set other signals to restore saved_tty_pgrp */
7181 set_fatal_handlers();
7182 /* Put ourselves in our own process group
7183 * (bash, too, does this only if ctty is available) */
7184 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7185 /* Grab control of the terminal */
7186 tcsetpgrp(G_interactive_fd, getpid());
7188 /* -1 is special - makes xfuncs longjmp, not exit
7189 * (we reset die_sleep = 0 whereever we [v]fork) */
7190 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7194 #elif ENABLE_HUSH_INTERACTIVE
7195 /* No job control compiled in, only prompt/line editing */
7196 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7197 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7198 if (G_interactive_fd < 0) {
7199 /* try to dup to any fd */
7200 G_interactive_fd = dup(STDIN_FILENO);
7201 if (G_interactive_fd < 0)
7203 G_interactive_fd = 0;
7206 if (G_interactive_fd) {
7207 close_on_exec_on(G_interactive_fd);
7211 /* We have interactiveness code disabled */
7215 * if interactive but not a login shell, sources ~/.bashrc
7216 * (--norc turns this off, --rcfile <file> overrides)
7219 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7220 /* note: ash and hush share this string */
7221 printf("\n\n%s %s\n"
7222 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7225 "hush - the humble shell"
7229 parse_and_run_file(stdin);
7232 #if ENABLE_FEATURE_CLEAN_UP
7233 if (G.cwd != bb_msg_unknown)
7235 cur_var = G.top_var->next;
7237 struct variable *tmp = cur_var;
7238 if (!cur_var->max_len)
7239 free(cur_var->varstr);
7240 cur_var = cur_var->next;
7244 hush_exit(G.last_exitcode);
7249 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7250 int lash_main(int argc, char **argv)
7252 bb_error_msg("lash is deprecated, please use hush instead");
7253 return hush_main(argc, argv);
7258 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7259 int msh_main(int argc, char **argv)
7261 //bb_error_msg("msh is deprecated, please use hush instead");
7262 return hush_main(argc, argv);
7270 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7275 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7282 return applet_main_func(argc, argv - argc);
7285 static int FAST_FUNC builtin_test(char **argv)
7287 return run_applet_main(argv, test_main);
7290 static int FAST_FUNC builtin_echo(char **argv)
7292 return run_applet_main(argv, echo_main);
7296 static int FAST_FUNC builtin_printf(char **argv)
7298 return run_applet_main(argv, printf_main);
7302 static char **skip_dash_dash(char **argv)
7305 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7310 static int FAST_FUNC builtin_eval(char **argv)
7312 int rcode = EXIT_SUCCESS;
7314 argv = skip_dash_dash(argv);
7316 char *str = expand_strvec_to_string(argv);
7318 * eval "echo Hi; done" ("done" is syntax error):
7319 * "echo Hi" will not execute too.
7321 parse_and_run_string(str);
7323 rcode = G.last_exitcode;
7328 static int FAST_FUNC builtin_cd(char **argv)
7332 argv = skip_dash_dash(argv);
7334 if (newdir == NULL) {
7335 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7336 * bash says "bash: cd: HOME not set" and does nothing
7339 const char *home = get_local_var_value("HOME");
7340 newdir = home ? home : "/";
7342 if (chdir(newdir)) {
7343 /* Mimic bash message exactly */
7344 bb_perror_msg("cd: %s", newdir);
7345 return EXIT_FAILURE;
7347 /* Read current dir (get_cwd(1) is inside) and set PWD.
7348 * Note: do not enforce exporting. If PWD was unset or unexported,
7349 * set it again, but do not export. bash does the same.
7351 set_pwd_var(/*exp:*/ 0);
7352 return EXIT_SUCCESS;
7355 static int FAST_FUNC builtin_exec(char **argv)
7357 argv = skip_dash_dash(argv);
7358 if (argv[0] == NULL)
7359 return EXIT_SUCCESS; /* bash does this */
7361 /* Careful: we can end up here after [v]fork. Do not restore
7362 * tty pgrp then, only top-level shell process does that */
7363 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7364 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7366 /* TODO: if exec fails, bash does NOT exit! We do.
7367 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7368 * and tcsetpgrp, and this is inherently racy.
7370 execvp_or_die(argv);
7373 static int FAST_FUNC builtin_exit(char **argv)
7375 debug_printf_exec("%s()\n", __func__);
7377 /* interactive bash:
7378 * # trap "echo EEE" EXIT
7381 * There are stopped jobs.
7382 * (if there are _stopped_ jobs, running ones don't count)
7385 # EEE (then bash exits)
7387 * we can use G.exiting = -1 as indicator "last cmd was exit"
7390 /* note: EXIT trap is run by hush_exit */
7391 argv = skip_dash_dash(argv);
7392 if (argv[0] == NULL)
7393 hush_exit(G.last_exitcode);
7394 /* mimic bash: exit 123abc == exit 255 + error msg */
7395 xfunc_error_retval = 255;
7396 /* bash: exit -2 == exit 254, no error msg */
7397 hush_exit(xatoi(argv[0]) & 0xff);
7400 static void print_escaped(const char *s)
7405 const char *p = strchrnul(s, '\'');
7406 /* print 'xxxx', possibly just '' */
7407 printf("'%.*s'", (int)(p - s), s);
7412 /* s points to '; print "'''...'''" */
7414 do putchar('\''); while (*++s == '\'');
7419 #if !ENABLE_HUSH_LOCAL
7420 #define helper_export_local(argv, exp, lvl) \
7421 helper_export_local(argv, exp)
7423 static void helper_export_local(char **argv, int exp, int lvl)
7428 /* So far we do not check that name is valid (TODO?) */
7430 if (strchr(name, '=') == NULL) {
7431 struct variable *var;
7433 var = get_local_var(name);
7434 if (exp == -1) { /* unexporting? */
7435 /* export -n NAME (without =VALUE) */
7437 var->flg_export = 0;
7438 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7440 } /* else: export -n NOT_EXISTING_VAR: no-op */
7443 if (exp == 1) { /* exporting? */
7444 /* export NAME (without =VALUE) */
7446 var->flg_export = 1;
7447 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7448 putenv(var->varstr);
7452 /* Exporting non-existing variable.
7453 * bash does not put it in environment,
7454 * but remembers that it is exported,
7455 * and does put it in env when it is set later.
7456 * We just set it to "" and export. */
7457 /* Or, it's "local NAME" (without =VALUE).
7458 * bash sets the value to "". */
7459 name = xasprintf("%s=", name);
7461 /* (Un)exporting/making local NAME=VALUE */
7462 name = xstrdup(name);
7464 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7468 static int FAST_FUNC builtin_export(char **argv)
7470 unsigned opt_unexport;
7472 #if ENABLE_HUSH_EXPORT_N
7473 /* "!": do not abort on errors */
7474 opt_unexport = getopt32(argv, "!n");
7475 if (opt_unexport == (uint32_t)-1)
7476 return EXIT_FAILURE;
7483 if (argv[0] == NULL) {
7490 /* ash emits: export VAR='VAL'
7491 * bash: declare -x VAR="VAL"
7492 * we follow ash example */
7493 const char *s = *e++;
7494 const char *p = strchr(s, '=');
7496 if (!p) /* wtf? take next variable */
7499 printf("export %.*s", (int)(p - s) + 1, s);
7500 print_escaped(p + 1);
7504 /*fflush_all(); - done after each builtin anyway */
7506 return EXIT_SUCCESS;
7509 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7511 return EXIT_SUCCESS;
7514 #if ENABLE_HUSH_LOCAL
7515 static int FAST_FUNC builtin_local(char **argv)
7517 if (G.func_nest_level == 0) {
7518 bb_error_msg("%s: not in a function", argv[0]);
7519 return EXIT_FAILURE; /* bash compat */
7521 helper_export_local(argv, 0, G.func_nest_level);
7522 return EXIT_SUCCESS;
7526 static int FAST_FUNC builtin_trap(char **argv)
7532 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7537 /* No args: print all trapped */
7538 for (i = 0; i < NSIG; ++i) {
7541 print_escaped(G.traps[i]);
7542 /* note: bash adds "SIG", but only if invoked
7543 * as "bash". If called as "sh", or if set -o posix,
7544 * then it prints short signal names.
7545 * We are printing short names: */
7546 printf(" %s\n", get_signame(i));
7549 /*fflush_all(); - done after each builtin anyway */
7550 return EXIT_SUCCESS;
7554 /* If first arg is a number: reset all specified signals */
7555 sig = bb_strtou(*argv, NULL, 10);
7561 sig = get_signum(*argv++);
7562 if (sig < 0 || sig >= NSIG) {
7564 /* Mimic bash message exactly */
7565 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7570 G.traps[sig] = xstrdup(new_cmd);
7572 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7573 get_signame(sig), sig, G.traps[sig]);
7575 /* There is no signal for 0 (EXIT) */
7580 sigaddset(&G.blocked_set, sig);
7582 /* There was a trap handler, we are removing it
7583 * (if sig has non-DFL handling,
7584 * we don't need to do anything) */
7585 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7587 sigdelset(&G.blocked_set, sig);
7590 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7594 if (!argv[1]) { /* no second arg */
7595 bb_error_msg("trap: invalid arguments");
7596 return EXIT_FAILURE;
7599 /* First arg is "-": reset all specified to default */
7600 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7601 /* Everything else: set arg as signal handler
7602 * (includes "" case, which ignores signal) */
7603 if (argv[0][0] == '-') {
7604 if (argv[0][1] == '\0') { /* "-" */
7605 /* new_cmd remains NULL: "reset these sigs" */
7608 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7611 /* else: "-something", no special meaning */
7616 goto process_sig_list;
7619 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7620 static int FAST_FUNC builtin_type(char **argv)
7622 int ret = EXIT_SUCCESS;
7628 if (0) {} /* make conditional compile easier below */
7629 /*else if (find_alias(*argv))
7630 type = "an alias";*/
7631 #if ENABLE_HUSH_FUNCTIONS
7632 else if (find_function(*argv))
7633 type = "a function";
7635 else if (find_builtin(*argv))
7636 type = "a shell builtin";
7637 else if ((path = find_in_path(*argv)) != NULL)
7640 bb_error_msg("type: %s: not found", *argv);
7645 printf("%s is %s\n", *argv, type);
7653 /* built-in 'fg' and 'bg' handler */
7654 static int FAST_FUNC builtin_fg_bg(char **argv)
7659 if (!G_interactive_fd)
7660 return EXIT_FAILURE;
7662 /* If they gave us no args, assume they want the last backgrounded task */
7664 for (pi = G.job_list; pi; pi = pi->next) {
7665 if (pi->jobid == G.last_jobid) {
7669 bb_error_msg("%s: no current job", argv[0]);
7670 return EXIT_FAILURE;
7672 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7673 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7674 return EXIT_FAILURE;
7676 for (pi = G.job_list; pi; pi = pi->next) {
7677 if (pi->jobid == jobnum) {
7681 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7682 return EXIT_FAILURE;
7684 /* TODO: bash prints a string representation
7685 * of job being foregrounded (like "sleep 1 | cat") */
7686 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7687 /* Put the job into the foreground. */
7688 tcsetpgrp(G_interactive_fd, pi->pgrp);
7691 /* Restart the processes in the job */
7692 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7693 for (i = 0; i < pi->num_cmds; i++) {
7694 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7695 pi->cmds[i].is_stopped = 0;
7697 pi->stopped_cmds = 0;
7699 i = kill(- pi->pgrp, SIGCONT);
7701 if (errno == ESRCH) {
7702 delete_finished_bg_job(pi);
7703 return EXIT_SUCCESS;
7705 bb_perror_msg("kill (SIGCONT)");
7708 if (argv[0][0] == 'f') {
7710 return checkjobs_and_fg_shell(pi);
7712 return EXIT_SUCCESS;
7716 #if ENABLE_HUSH_HELP
7717 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7719 const struct built_in_command *x;
7722 "Built-in commands:\n"
7723 "------------------\n");
7724 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7726 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7729 return EXIT_SUCCESS;
7734 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7737 const char *status_string;
7739 for (job = G.job_list; job; job = job->next) {
7740 if (job->alive_cmds == job->stopped_cmds)
7741 status_string = "Stopped";
7743 status_string = "Running";
7745 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7747 return EXIT_SUCCESS;
7752 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7757 # ifdef M_TRIM_THRESHOLD
7758 /* Optional. Reduces probability of false positives */
7761 /* Crude attempt to find where "free memory" starts,
7762 * sans fragmentation. */
7764 l = (unsigned long)p;
7767 if (l < (unsigned long)p) l = (unsigned long)p;
7770 if (!G.memleak_value)
7771 G.memleak_value = l;
7773 l -= G.memleak_value;
7780 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7785 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7788 return EXIT_SUCCESS;
7791 static int FAST_FUNC builtin_read(char **argv)
7800 /* "!": do not abort on errors.
7801 * Option string must start with "sr" to match BUILTIN_READ_xxx
7803 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7804 if (read_flags == (uint32_t)-1)
7805 return EXIT_FAILURE;
7808 r = shell_builtin_read(set_local_var_from_halves,
7810 get_local_var_value("IFS"), /* can be NULL */
7818 if ((uintptr_t)r > 1) {
7819 bb_error_msg("%s", r);
7820 r = (char*)(uintptr_t)1;
7823 return (uintptr_t)r;
7826 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7827 * built-in 'set' handler
7829 * set [-abCefhmnuvx] [-o option] [argument...]
7830 * set [+abCefhmnuvx] [+o option] [argument...]
7831 * set -- [argument...]
7834 * Implementations shall support the options in both their hyphen and
7835 * plus-sign forms. These options can also be specified as options to sh.
7837 * Write out all variables and their values: set
7838 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7839 * Turn on the -x and -v options: set -xv
7840 * Unset all positional parameters: set --
7841 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7842 * Set the positional parameters to the expansion of x, even if x expands
7843 * with a leading '-' or '+': set -- $x
7845 * So far, we only support "set -- [argument...]" and some of the short names.
7847 static int FAST_FUNC builtin_set(char **argv)
7850 char **pp, **g_argv;
7851 char *arg = *++argv;
7855 for (e = G.top_var; e; e = e->next)
7857 return EXIT_SUCCESS;
7861 if (!strcmp(arg, "--")) {
7865 if (arg[0] != '+' && arg[0] != '-')
7867 for (n = 1; arg[n]; ++n)
7868 if (set_mode(arg[0], arg[n]))
7870 } while ((arg = *++argv) != NULL);
7871 /* Now argv[0] is 1st argument */
7874 return EXIT_SUCCESS;
7877 /* NB: G.global_argv[0] ($0) is never freed/changed */
7878 g_argv = G.global_argv;
7879 if (G.global_args_malloced) {
7885 G.global_args_malloced = 1;
7886 pp = xzalloc(sizeof(pp[0]) * 2);
7887 pp[0] = g_argv[0]; /* retain $0 */
7890 /* This realloc's G.global_argv */
7891 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7898 return EXIT_SUCCESS;
7900 /* Nothing known, so abort */
7902 bb_error_msg("set: %s: invalid option", arg);
7903 return EXIT_FAILURE;
7906 static int FAST_FUNC builtin_shift(char **argv)
7909 argv = skip_dash_dash(argv);
7913 if (n >= 0 && n < G.global_argc) {
7914 if (G.global_args_malloced) {
7917 free(G.global_argv[m++]);
7920 memmove(&G.global_argv[1], &G.global_argv[n+1],
7921 G.global_argc * sizeof(G.global_argv[0]));
7922 return EXIT_SUCCESS;
7924 return EXIT_FAILURE;
7927 static int FAST_FUNC builtin_source(char **argv)
7929 char *arg_path, *filename;
7932 #if ENABLE_HUSH_FUNCTIONS
7936 argv = skip_dash_dash(argv);
7939 /* bash says: "bash: .: filename argument required" */
7940 return 2; /* bash compat */
7943 if (!strchr(filename, '/')) {
7944 arg_path = find_in_path(filename);
7946 filename = arg_path;
7948 input = fopen_or_warn(filename, "r");
7951 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7952 return EXIT_FAILURE;
7954 close_on_exec_on(fileno(input));
7956 #if ENABLE_HUSH_FUNCTIONS
7957 sv_flg = G.flag_return_in_progress;
7958 /* "we are inside sourced file, ok to use return" */
7959 G.flag_return_in_progress = -1;
7961 save_and_replace_G_args(&sv, argv);
7963 parse_and_run_file(input);
7966 restore_G_args(&sv, argv);
7967 #if ENABLE_HUSH_FUNCTIONS
7968 G.flag_return_in_progress = sv_flg;
7971 return G.last_exitcode;
7974 static int FAST_FUNC builtin_umask(char **argv)
7980 argv = skip_dash_dash(argv);
7982 mode_t old_mask = mask;
7985 rc = bb_parse_mode(argv[0], &mask);
7990 * bash: umask: 'q': invalid symbolic mode operator
7991 * bash: umask: 999: octal number out of range
7993 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
7998 printf("%04o\n", (unsigned) mask);
7999 /* fall through and restore mask which we set to 0 */
8003 return !rc; /* rc != 0 - success */
8006 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8007 static int FAST_FUNC builtin_unset(char **argv)
8012 /* "!": do not abort on errors */
8013 /* "+": stop at 1st non-option */
8014 opts = getopt32(argv, "!+vf");
8015 if (opts == (unsigned)-1)
8016 return EXIT_FAILURE;
8018 bb_error_msg("unset: -v and -f are exclusive");
8019 return EXIT_FAILURE;
8025 if (!(opts & 2)) { /* not -f */
8026 if (unset_local_var(*argv)) {
8027 /* unset <nonexistent_var> doesn't fail.
8028 * Error is when one tries to unset RO var.
8029 * Message was printed by unset_local_var. */
8033 #if ENABLE_HUSH_FUNCTIONS
8043 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8044 static int FAST_FUNC builtin_wait(char **argv)
8046 int ret = EXIT_SUCCESS;
8049 argv = skip_dash_dash(argv);
8050 if (argv[0] == NULL) {
8051 /* Don't care about wait results */
8052 /* Note 1: must wait until there are no more children */
8053 /* Note 2: must be interruptible */
8055 * $ sleep 3 & sleep 6 & wait
8060 * $ sleep 3 & sleep 6 & wait
8064 * ^C <-- after ~4 sec from keyboard
8067 sigaddset(&G.blocked_set, SIGCHLD);
8068 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8071 if (errno == ECHILD)
8073 /* Wait for SIGCHLD or any other signal of interest */
8074 /* sigtimedwait with infinite timeout: */
8075 sig = sigwaitinfo(&G.blocked_set, NULL);
8077 sig = check_and_run_traps(sig);
8078 if (sig && sig != SIGCHLD) { /* see note 2 */
8084 sigdelset(&G.blocked_set, SIGCHLD);
8085 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8089 /* This is probably buggy wrt interruptible-ness */
8091 pid_t pid = bb_strtou(*argv, NULL, 10);
8093 /* mimic bash message */
8094 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8095 return EXIT_FAILURE;
8097 if (waitpid(pid, &status, 0) == pid) {
8098 if (WIFSIGNALED(status))
8099 ret = 128 + WTERMSIG(status);
8100 else if (WIFEXITED(status))
8101 ret = WEXITSTATUS(status);
8105 bb_perror_msg("wait %s", *argv);
8114 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8115 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8118 def = bb_strtou(argv[1], NULL, 10);
8119 if (errno || def < def_min || argv[2]) {
8120 bb_error_msg("%s: bad arguments", argv[0]);
8128 #if ENABLE_HUSH_LOOPS
8129 static int FAST_FUNC builtin_break(char **argv)
8132 if (G.depth_of_loop == 0) {
8133 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8134 return EXIT_SUCCESS; /* bash compat */
8136 G.flag_break_continue++; /* BC_BREAK = 1 */
8138 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8139 if (depth == UINT_MAX)
8140 G.flag_break_continue = BC_BREAK;
8141 if (G.depth_of_loop < depth)
8142 G.depth_break_continue = G.depth_of_loop;
8144 return EXIT_SUCCESS;
8147 static int FAST_FUNC builtin_continue(char **argv)
8149 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8150 return builtin_break(argv);
8154 #if ENABLE_HUSH_FUNCTIONS
8155 static int FAST_FUNC builtin_return(char **argv)
8159 if (G.flag_return_in_progress != -1) {
8160 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8161 return EXIT_FAILURE; /* bash compat */
8164 G.flag_return_in_progress = 1;
8167 * out of range: wraps around at 256, does not error out
8168 * non-numeric param:
8169 * f() { false; return qwe; }; f; echo $?
8170 * bash: return: qwe: numeric argument required <== we do this
8171 * 255 <== we also do this
8173 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);