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.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
45 * Bash stuff (optionally enabled):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
51 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
52 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
53 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
55 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
56 * This is exactly equivalent to let "expression".
59 * grep for "TODO" and fix (some of them are easy)
60 * special variables (done: PWD, PPID, RANDOM)
61 * follow IFS rules more precisely, including update semantics
62 * export builtin should be special, its arguments are assignments
63 * and therefore expansion of them should be "one-word" expansion:
64 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
66 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
67 * ls: cannot access i=a: No such file or directory
68 * ls: cannot access b: No such file or directory
69 * Note1: same applies to local builtin.
70 * Note2: bash 3.2.33(1) does this only if export word itself
72 * $ export i=`echo 'aaa bbb'`; echo "$i"
74 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
77 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
79 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
80 #include <malloc.h> /* for malloc_trim */
82 /* #include <dmalloc.h> */
87 #include "shell_common.h"
88 #include "builtin_read.h"
89 #include "builtin_ulimit.h"
92 #if ENABLE_HUSH_RANDOM_SUPPORT
95 # define CLEAR_RANDOM_T(rnd) ((void)0)
98 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
103 #define LEAK_HUNTING 0
104 #define BUILD_AS_NOMMU 0
105 /* Enable/disable sanity checks. Ok to enable in production,
106 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
107 * Keeping 1 for now even in released versions.
110 /* Slightly bigger (+200 bytes), but faster hush.
111 * So far it only enables a trick with counting SIGCHLDs and forks,
112 * which allows us to do fewer waitpid's.
113 * (we can detect a case where neither forks were done nor SIGCHLDs happened
114 * and therefore waitpid will return the same result as last time)
116 #define ENABLE_HUSH_FAST 0
121 # undef USE_FOR_NOMMU
124 # define USE_FOR_NOMMU(...) __VA_ARGS__
125 # define USE_FOR_MMU(...)
128 #define SKIP_definitions 1
129 #include "applet_tables.h"
130 #undef SKIP_definitions
132 /* STANDALONE does not make sense, and won't compile */
133 # undef CONFIG_FEATURE_SH_STANDALONE
134 # undef ENABLE_FEATURE_SH_STANDALONE
135 # undef IF_FEATURE_SH_STANDALONE
136 # undef IF_NOT_FEATURE_SH_STANDALONE
137 # define ENABLE_FEATURE_SH_STANDALONE 0
138 # define IF_FEATURE_SH_STANDALONE(...)
139 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
142 #if !ENABLE_HUSH_INTERACTIVE
143 # undef ENABLE_FEATURE_EDITING
144 # define ENABLE_FEATURE_EDITING 0
145 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
146 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
149 /* Do we support ANY keywords? */
150 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
151 # define HAS_KEYWORDS 1
152 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
153 # define IF_HAS_NO_KEYWORDS(...)
155 # define HAS_KEYWORDS 0
156 # define IF_HAS_KEYWORDS(...)
157 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
160 /* If you comment out one of these below, it will be #defined later
161 * to perform debug printfs to stderr: */
162 #define debug_printf(...) do {} while (0)
163 /* Finer-grained debug switches */
164 #define debug_printf_parse(...) do {} while (0)
165 #define debug_print_tree(a, b) do {} while (0)
166 #define debug_printf_exec(...) do {} while (0)
167 #define debug_printf_env(...) do {} while (0)
168 #define debug_printf_jobs(...) do {} while (0)
169 #define debug_printf_expand(...) do {} while (0)
170 #define debug_printf_glob(...) do {} while (0)
171 #define debug_printf_list(...) do {} while (0)
172 #define debug_printf_subst(...) do {} while (0)
173 #define debug_printf_clean(...) do {} while (0)
175 #define ERR_PTR ((void*)(long)1)
177 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
179 #define SPECIAL_VAR_SYMBOL 3
183 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
185 /* This supports saving pointers malloced in vfork child,
186 * to be freed in the parent.
189 typedef struct nommu_save_t {
191 struct variable *old_vars;
193 char **argv_from_re_execing;
197 typedef enum reserved_style {
206 #if ENABLE_HUSH_LOOPS
213 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
218 /* three pseudo-keywords support contrived "case" syntax: */
219 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
220 RES_MATCH , /* "word)" */
221 RES_CASE_BODY, /* "this command is inside CASE" */
228 typedef struct o_string {
230 int length; /* position where data is appended */
232 /* Protect newly added chars against globbing
233 * (by prepending \ to *, ?, [, \) */
236 /* At least some part of the string was inside '' or "",
237 * possibly empty one: word"", wo''rd etc. */
239 smallint has_empty_slot;
240 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
243 MAYBE_ASSIGNMENT = 0,
244 DEFINITELY_ASSIGNMENT = 1,
246 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
248 /* Used for initialization: o_string foo = NULL_O_STRING; */
249 #define NULL_O_STRING { NULL }
251 /* I can almost use ordinary FILE*. Is open_memstream() universally
252 * available? Where is it documented? */
253 typedef struct in_str {
255 /* eof_flag=1: last char in ->p is really an EOF */
256 char eof_flag; /* meaningless if ->p == NULL */
258 #if ENABLE_HUSH_INTERACTIVE
260 smallint promptmode; /* 0: PS1, 1: PS2 */
263 int (*get) (struct in_str *) FAST_FUNC;
264 int (*peek) (struct in_str *) FAST_FUNC;
266 #define i_getch(input) ((input)->get(input))
267 #define i_peek(input) ((input)->peek(input))
269 /* The descrip member of this structure is only used to make
270 * debugging output pretty */
271 static const struct {
273 signed char default_fd;
276 { O_RDONLY, 0, "<" },
277 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
278 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
279 { O_CREAT|O_RDWR, 1, "<>" },
280 { O_RDONLY, 0, "<<" },
281 /* Should not be needed. Bogus default_fd helps in debugging */
282 /* { O_RDONLY, 77, "<<" }, */
285 struct redir_struct {
286 struct redir_struct *next;
287 char *rd_filename; /* filename */
288 int rd_fd; /* fd to redirect */
289 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
291 smallint rd_type; /* (enum redir_type) */
292 /* note: for heredocs, rd_filename contains heredoc delimiter,
293 * and subsequently heredoc itself; and rd_dup is a bitmask:
294 * bit 0: do we need to trim leading tabs?
295 * bit 1: is heredoc quoted (<<'delim' syntax) ?
298 typedef enum redir_type {
300 REDIRECT_OVERWRITE = 1,
303 REDIRECT_HEREDOC = 4,
304 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
307 REDIRFD_SYNTAX_ERR = -2,
308 REDIRFD_TO_FILE = -1,
309 /* otherwise, rd_fd is redirected to rd_dup */
311 HEREDOC_SKIPTABS = 1,
317 pid_t pid; /* 0 if exited */
318 int assignment_cnt; /* how many argv[i] are assignments? */
319 smallint is_stopped; /* is the command currently running? */
320 smallint cmd_type; /* CMD_xxx */
322 #define CMD_SUBSHELL 1
324 /* used for "[[ EXPR ]]" */
325 #if ENABLE_HUSH_BASH_COMPAT
326 # define CMD_SINGLEWORD_NOGLOB 2
329 /* used for "export noglob=* glob* a=`echo a b`" */
330 //#define CMD_SINGLEWORD_NOGLOB_COND 3
331 // It is hard to implement correctly, it adds significant amounts of tricky code,
332 // and all this is only useful for really obscure export statements
333 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
334 // guards the code which implements it, but I have doubts it works
335 // in all cases (especially with mixed globbed/non-globbed arguments)
337 #if ENABLE_HUSH_FUNCTIONS
338 # define CMD_FUNCDEF 3
341 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
344 char *group_as_string;
346 #if ENABLE_HUSH_FUNCTIONS
347 struct function *child_func;
348 /* This field is used to prevent a bug here:
349 * while...do f1() {a;}; f1; f1() {b;}; f1; done
350 * When we execute "f1() {a;}" cmd, we create new function and clear
351 * cmd->group, cmd->group_as_string, cmd->argv[0].
352 * When we execute "f1() {b;}", we notice that f1 exists,
353 * and that its "parent cmd" struct is still "alive",
354 * we put those fields back into cmd->xxx
355 * (struct function has ->parent_cmd ptr to facilitate that).
356 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
357 * Without this trick, loop would execute a;b;b;b;...
358 * instead of correct sequence a;b;a;b;...
359 * When command is freed, it severs the link
360 * (sets ->child_func->parent_cmd to NULL).
363 char **argv; /* command name and arguments */
364 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
365 * and on execution these are substituted with their values.
366 * Substitution can make _several_ words out of one argv[n]!
367 * Example: argv[0]=='.^C*^C.' here: echo .$*.
368 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
370 struct redir_struct *redirects; /* I/O redirections */
372 /* Is there anything in this command at all? */
373 #define IS_NULL_CMD(cmd) \
374 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
379 int num_cmds; /* total number of commands in pipe */
380 int alive_cmds; /* number of commands running (not exited) */
381 int stopped_cmds; /* number of commands alive, but stopped */
383 int jobid; /* job number */
384 pid_t pgrp; /* process group ID for the job */
385 char *cmdtext; /* name of job */
387 struct command *cmds; /* array of commands in pipe */
388 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
389 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
390 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
392 typedef enum pipe_style {
398 /* Is there anything in this pipe at all? */
399 #define IS_NULL_PIPE(pi) \
400 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
402 /* This holds pointers to the various results of parsing */
403 struct parse_context {
404 /* linked list of pipes */
405 struct pipe *list_head;
406 /* last pipe (being constructed right now) */
408 /* last command in pipe (being constructed right now) */
409 struct command *command;
410 /* last redirect in command->redirects list */
411 struct redir_struct *pending_redirect;
417 smallint ctx_inverted; /* "! cmd | cmd" */
419 smallint ctx_dsemicolon; /* ";;" seen */
421 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
423 /* group we are enclosed in:
424 * example: "if pipe1; pipe2; then pipe3; fi"
425 * when we see "if" or "then", we malloc and copy current context,
426 * and make ->stack point to it. then we parse pipeN.
427 * when closing "then" / fi" / whatever is found,
428 * we move list_head into ->stack->command->group,
429 * copy ->stack into current context, and delete ->stack.
430 * (parsing of { list } and ( list ) doesn't use this method)
432 struct parse_context *stack;
436 /* On program start, environ points to initial environment.
437 * putenv adds new pointers into it, unsetenv removes them.
438 * Neither of these (de)allocates the strings.
439 * setenv allocates new strings in malloc space and does putenv,
440 * and thus setenv is unusable (leaky) for shell's purposes */
441 #define setenv(...) setenv_is_leaky_dont_use()
443 struct variable *next;
444 char *varstr; /* points to "name=" portion */
445 #if ENABLE_HUSH_LOCAL
446 unsigned func_nest_level;
448 int max_len; /* if > 0, name is part of initial env; else name is malloced */
449 smallint flg_export; /* putenv should be done on this var */
450 smallint flg_read_only;
458 #if ENABLE_HUSH_FUNCTIONS
460 struct function *next;
462 struct command *parent_cmd;
465 char *body_as_string;
471 /* "Globals" within this file */
472 /* Sorted roughly by size (smaller offsets == smaller code) */
474 /* interactive_fd != 0 means we are an interactive shell.
475 * If we are, then saved_tty_pgrp can also be != 0, meaning
476 * that controlling tty is available. With saved_tty_pgrp == 0,
477 * job control still works, but terminal signals
478 * (^C, ^Z, ^Y, ^\) won't work at all, and background
479 * process groups can only be created with "cmd &".
480 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
481 * to give tty to the foreground process group,
482 * and will take it back when the group is stopped (^Z)
485 #if ENABLE_HUSH_INTERACTIVE
486 /* 'interactive_fd' is a fd# open to ctty, if we have one
487 * _AND_ if we decided to act interactively */
491 # define G_interactive_fd (G.interactive_fd)
493 # define G_interactive_fd 0
495 #if ENABLE_FEATURE_EDITING
496 line_input_t *line_input_state;
501 #if ENABLE_HUSH_RANDOM_SUPPORT
507 pid_t saved_tty_pgrp;
508 struct pipe *job_list;
509 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
511 # define G_saved_tty_pgrp 0
513 smallint flag_SIGINT;
514 #if ENABLE_HUSH_LOOPS
515 smallint flag_break_continue;
517 #if ENABLE_HUSH_FUNCTIONS
518 /* 0: outside of a function (or sourced file)
519 * -1: inside of a function, ok to use return builtin
520 * 1: return is invoked, skip all till end of func
522 smallint flag_return_in_progress;
525 smallint exiting; /* used to prevent EXIT trap recursion */
526 /* These four support $?, $#, and $1 */
527 smalluint last_exitcode;
528 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
529 smalluint global_args_malloced;
530 smalluint inherited_set_is_saved;
531 /* how many non-NULL argv's we have. NB: $# + 1 */
535 char *argv0_for_re_execing;
537 #if ENABLE_HUSH_LOOPS
538 unsigned depth_break_continue;
539 unsigned depth_of_loop;
543 struct variable *top_var; /* = &G.shell_ver (set in main()) */
544 struct variable shell_ver;
545 #if ENABLE_HUSH_FUNCTIONS
546 struct function *top_func;
547 # if ENABLE_HUSH_LOCAL
548 struct variable **shadowed_vars_pp;
549 unsigned func_nest_level;
552 /* Signal and trap handling */
554 unsigned count_SIGCHLD;
555 unsigned handled_SIGCHLD;
556 smallint we_have_children;
558 /* which signals have non-DFL handler (even with no traps set)? */
559 unsigned non_DFL_mask;
560 char **traps; /* char *traps[NSIG] */
561 sigset_t blocked_set;
562 sigset_t inherited_set;
564 unsigned long memleak_value;
567 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
569 #define G (*ptr_to_globals)
570 /* Not #defining name to G.name - this quickly gets unwieldy
571 * (too many defines). Also, I actually prefer to see when a variable
572 * is global, thus "G." prefix is a useful hint */
573 #define INIT_G() do { \
574 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
578 /* Function prototypes for builtins */
579 static int builtin_cd(char **argv) FAST_FUNC;
580 static int builtin_echo(char **argv) FAST_FUNC;
581 static int builtin_eval(char **argv) FAST_FUNC;
582 static int builtin_exec(char **argv) FAST_FUNC;
583 static int builtin_exit(char **argv) FAST_FUNC;
584 static int builtin_export(char **argv) FAST_FUNC;
586 static int builtin_fg_bg(char **argv) FAST_FUNC;
587 static int builtin_jobs(char **argv) FAST_FUNC;
590 static int builtin_help(char **argv) FAST_FUNC;
592 #if ENABLE_HUSH_LOCAL
593 static int builtin_local(char **argv) FAST_FUNC;
596 static int builtin_memleak(char **argv) FAST_FUNC;
599 static int builtin_printf(char **argv) FAST_FUNC;
601 static int builtin_pwd(char **argv) FAST_FUNC;
602 static int builtin_read(char **argv) FAST_FUNC;
603 static int builtin_set(char **argv) FAST_FUNC;
604 static int builtin_shift(char **argv) FAST_FUNC;
605 static int builtin_source(char **argv) FAST_FUNC;
606 static int builtin_test(char **argv) FAST_FUNC;
607 static int builtin_trap(char **argv) FAST_FUNC;
608 static int builtin_type(char **argv) FAST_FUNC;
609 static int builtin_true(char **argv) FAST_FUNC;
610 static int builtin_umask(char **argv) FAST_FUNC;
611 static int builtin_unset(char **argv) FAST_FUNC;
612 static int builtin_wait(char **argv) FAST_FUNC;
613 #if ENABLE_HUSH_LOOPS
614 static int builtin_break(char **argv) FAST_FUNC;
615 static int builtin_continue(char **argv) FAST_FUNC;
617 #if ENABLE_HUSH_FUNCTIONS
618 static int builtin_return(char **argv) FAST_FUNC;
621 /* Table of built-in functions. They can be forked or not, depending on
622 * context: within pipes, they fork. As simple commands, they do not.
623 * When used in non-forking context, they can change global variables
624 * in the parent shell process. If forked, of course they cannot.
625 * For example, 'unset foo | whatever' will parse and run, but foo will
626 * still be set at the end. */
627 struct built_in_command {
629 int (*b_function)(char **argv) FAST_FUNC;
632 # define BLTIN(cmd, func, help) { cmd, func, help }
634 # define BLTIN(cmd, func, help) { cmd, func }
638 static const struct built_in_command bltins1[] = {
639 BLTIN("." , builtin_source , "Run commands in a file"),
640 BLTIN(":" , builtin_true , NULL),
642 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
644 #if ENABLE_HUSH_LOOPS
645 BLTIN("break" , builtin_break , "Exit from a loop"),
647 BLTIN("cd" , builtin_cd , "Change directory"),
648 #if ENABLE_HUSH_LOOPS
649 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
651 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
652 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
653 BLTIN("exit" , builtin_exit , "Exit"),
654 BLTIN("export" , builtin_export , "Set environment variables"),
656 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
659 BLTIN("help" , builtin_help , NULL),
662 BLTIN("jobs" , builtin_jobs , "List jobs"),
664 #if ENABLE_HUSH_LOCAL
665 BLTIN("local" , builtin_local , "Set local variables"),
668 BLTIN("memleak" , builtin_memleak , NULL),
670 BLTIN("read" , builtin_read , "Input into variable"),
671 #if ENABLE_HUSH_FUNCTIONS
672 BLTIN("return" , builtin_return , "Return from a function"),
674 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
675 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
676 BLTIN("trap" , builtin_trap , "Trap signals"),
677 BLTIN("type" , builtin_type , "Show command type"),
678 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
679 BLTIN("umask" , builtin_umask , "Set file creation mask"),
680 BLTIN("unset" , builtin_unset , "Unset variables"),
681 BLTIN("wait" , builtin_wait , "Wait for process"),
683 /* For now, echo and test are unconditionally enabled.
684 * Maybe make it configurable? */
685 static const struct built_in_command bltins2[] = {
686 BLTIN("[" , builtin_test , NULL),
687 BLTIN("echo" , builtin_echo , NULL),
689 BLTIN("printf" , builtin_printf , NULL),
691 BLTIN("pwd" , builtin_pwd , NULL),
692 BLTIN("test" , builtin_test , NULL),
699 /* prevent disasters with G.debug_indent < 0 */
700 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
701 # define debug_enter() (G.debug_indent++)
702 # define debug_leave() (G.debug_indent--)
704 # define indent() ((void)0)
705 # define debug_enter() ((void)0)
706 # define debug_leave() ((void)0)
710 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
713 #ifndef debug_printf_parse
714 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
717 #ifndef debug_printf_exec
718 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
721 #ifndef debug_printf_env
722 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
725 #ifndef debug_printf_jobs
726 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
727 # define DEBUG_JOBS 1
729 # define DEBUG_JOBS 0
732 #ifndef debug_printf_expand
733 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
734 # define DEBUG_EXPAND 1
736 # define DEBUG_EXPAND 0
739 #ifndef debug_printf_glob
740 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
741 # define DEBUG_GLOB 1
743 # define DEBUG_GLOB 0
746 #ifndef debug_printf_list
747 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
750 #ifndef debug_printf_subst
751 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
754 #ifndef debug_printf_clean
755 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
756 # define DEBUG_CLEAN 1
758 # define DEBUG_CLEAN 0
762 static void debug_print_strings(const char *prefix, char **vv)
765 fprintf(stderr, "%s:\n", prefix);
767 fprintf(stderr, " '%s'\n", *vv++);
770 # define debug_print_strings(prefix, vv) ((void)0)
774 /* Leak hunting. Use hush_leaktool.sh for post-processing.
777 static void *xxmalloc(int lineno, size_t size)
779 void *ptr = xmalloc((size + 0xff) & ~0xff);
780 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
783 static void *xxrealloc(int lineno, void *ptr, size_t size)
785 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
786 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
789 static char *xxstrdup(int lineno, const char *str)
791 char *ptr = xstrdup(str);
792 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
795 static void xxfree(void *ptr)
797 fdprintf(2, "free %p\n", ptr);
800 #define xmalloc(s) xxmalloc(__LINE__, s)
801 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
802 #define xstrdup(s) xxstrdup(__LINE__, s)
803 #define free(p) xxfree(p)
807 /* Syntax and runtime errors. They always abort scripts.
808 * In interactive use they usually discard unparsed and/or unexecuted commands
809 * and return to the prompt.
810 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
813 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
814 # define syntax_error(lineno, msg) syntax_error(msg)
815 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
816 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
817 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
818 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
821 static void die_if_script(unsigned lineno, const char *fmt, ...)
826 bb_error_msg("hush.c:%u", lineno);
829 bb_verror_msg(fmt, p, NULL);
831 if (!G_interactive_fd)
835 static void syntax_error(unsigned lineno, const char *msg)
838 die_if_script(lineno, "syntax error: %s", msg);
840 die_if_script(lineno, "syntax error", NULL);
843 static void syntax_error_at(unsigned lineno, const char *msg)
845 die_if_script(lineno, "syntax error at '%s'", msg);
848 static void syntax_error_unterm_str(unsigned lineno, const char *s)
850 die_if_script(lineno, "syntax error: unterminated %s", s);
853 /* It so happens that all such cases are totally fatal
854 * even if shell is interactive: EOF while looking for closing
855 * delimiter. There is nowhere to read stuff from after that,
856 * it's EOF! The only choice is to terminate.
858 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
859 static void syntax_error_unterm_ch(unsigned lineno, char ch)
861 char msg[2] = { ch, '\0' };
862 syntax_error_unterm_str(lineno, msg);
866 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
871 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
875 # undef die_if_script
877 # undef syntax_error_at
878 # undef syntax_error_unterm_ch
879 # undef syntax_error_unterm_str
880 # undef syntax_error_unexpected_ch
882 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
883 # define syntax_error(msg) syntax_error(__LINE__, msg)
884 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
885 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
886 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
887 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
891 #if ENABLE_HUSH_INTERACTIVE
892 static void cmdedit_update_prompt(void);
894 # define cmdedit_update_prompt() ((void)0)
900 /* Replace each \x with x in place, return ptr past NUL. */
901 static char *unbackslash(char *src)
903 char *dst = src = strchrnul(src, '\\');
907 if ((*dst++ = *src++) == '\0')
913 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
934 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
935 v[count1 + count2] = NULL;
938 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
942 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
944 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
945 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
948 #define add_strings_to_strings(strings, add, need_to_dup) \
949 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
952 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
953 static char **add_string_to_strings(char **strings, char *add)
958 return add_strings_to_strings(strings, v, /*dup:*/ 0);
961 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
963 char **ptr = add_string_to_strings(strings, add);
964 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
967 #define add_string_to_strings(strings, add) \
968 xx_add_string_to_strings(__LINE__, strings, add)
971 static void free_strings(char **strings)
986 /* Helpers for setting new $n and restoring them back
988 typedef struct save_arg_t {
992 smallint sv_g_malloced;
995 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
999 sv->sv_argv0 = argv[0];
1000 sv->sv_g_argv = G.global_argv;
1001 sv->sv_g_argc = G.global_argc;
1002 sv->sv_g_malloced = G.global_args_malloced;
1004 argv[0] = G.global_argv[0]; /* retain $0 */
1005 G.global_argv = argv;
1006 G.global_args_malloced = 0;
1014 static void restore_G_args(save_arg_t *sv, char **argv)
1018 if (G.global_args_malloced) {
1019 /* someone ran "set -- arg1 arg2 ...", undo */
1021 while (*++pp) /* note: does not free $0 */
1023 free(G.global_argv);
1025 argv[0] = sv->sv_argv0;
1026 G.global_argv = sv->sv_g_argv;
1027 G.global_argc = sv->sv_g_argc;
1028 G.global_args_malloced = sv->sv_g_malloced;
1032 /* Basic theory of signal handling in shell
1033 * ========================================
1034 * This does not describe what hush does, rather, it is current understanding
1035 * what it _should_ do. If it doesn't, it's a bug.
1036 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1038 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1039 * is finished or backgrounded. It is the same in interactive and
1040 * non-interactive shells, and is the same regardless of whether
1041 * a user trap handler is installed or a shell special one is in effect.
1042 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1043 * backgrounds (i.e. stops) or kills all members of currently running
1046 * Wait builtin in interruptible by signals for which user trap is set
1047 * or by SIGINT in interactive shell.
1049 * Trap handlers will execute even within trap handlers. (right?)
1051 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1052 * except for handlers set to '' (empty string).
1054 * If job control is off, backgrounded commands ("cmd &")
1055 * have SIGINT, SIGQUIT set to SIG_IGN.
1057 * Commands which are run in command substitution ("`cmd`")
1058 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1060 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1061 * by the shell from its parent.
1063 * Signals which differ from SIG_DFL action
1064 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1067 * SIGTERM (interactive): ignore
1068 * SIGHUP (interactive):
1069 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1070 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1071 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1072 * that all pipe members are stopped. Try this in bash:
1073 * while :; do :; done - ^Z does not background it
1074 * (while :; do :; done) - ^Z backgrounds it
1075 * SIGINT (interactive): wait for last pipe, ignore the rest
1076 * of the command line, show prompt. NB: ^C does not send SIGINT
1077 * to interactive shell while shell is waiting for a pipe,
1078 * since shell is bg'ed (is not in foreground process group).
1079 * Example 1: this waits 5 sec, but does not execute ls:
1080 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1081 * Example 2: this does not wait and does not execute ls:
1082 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1083 * Example 3: this does not wait 5 sec, but executes ls:
1084 * "sleep 5; ls -l" + press ^C
1086 * (What happens to signals which are IGN on shell start?)
1087 * (What happens with signal mask on shell start?)
1089 * Implementation in hush
1090 * ======================
1091 * We use in-kernel pending signal mask to determine which signals were sent.
1092 * We block all signals which we don't want to take action immediately,
1093 * i.e. we block all signals which need to have special handling as described
1094 * above, and all signals which have traps set.
1095 * After each pipe execution, we extract any pending signals via sigtimedwait()
1098 * unsigned non_DFL_mask: a mask of such "special" signals
1099 * sigset_t blocked_set: current blocked signal set
1102 * clear bit in blocked_set unless it is also in non_DFL_mask
1103 * "trap 'cmd' SIGxxx":
1104 * set bit in blocked_set (even if 'cmd' is '')
1105 * after [v]fork, if we plan to be a shell:
1106 * unblock signals with special interactive handling
1107 * (child shell is not interactive),
1108 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1109 * after [v]fork, if we plan to exec:
1110 * POSIX says fork clears pending signal mask in child - no need to clear it.
1111 * Restore blocked signal set to one inherited by shell just prior to exec.
1113 * Note: as a result, we do not use signal handlers much. The only uses
1114 * are to count SIGCHLDs
1115 * and to restore tty pgrp on signal-induced exit.
1118 * Standard says "When a subshell is entered, traps that are not being ignored
1119 * are set to the default actions". bash interprets it so that traps which
1120 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1123 SPECIAL_INTERACTIVE_SIGS = 0
1128 SPECIAL_JOB_SIGS = 0
1136 #if ENABLE_HUSH_FAST
1137 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1140 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1146 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1147 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1148 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1149 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1151 /* Restores tty foreground process group, and exits.
1152 * May be called as signal handler for fatal signal
1153 * (will resend signal to itself, producing correct exit state)
1154 * or called directly with -EXITCODE.
1155 * We also call it if xfunc is exiting. */
1156 static void sigexit(int sig) NORETURN;
1157 static void sigexit(int sig)
1159 /* Disable all signals: job control, SIGPIPE, etc. */
1160 sigprocmask_allsigs(SIG_BLOCK);
1162 /* Careful: we can end up here after [v]fork. Do not restore
1163 * tty pgrp then, only top-level shell process does that */
1164 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1165 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1167 /* Not a signal, just exit */
1171 kill_myself_with_sig(sig); /* does not return */
1175 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1176 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1180 /* Restores tty foreground process group, and exits. */
1181 static void hush_exit(int exitcode) NORETURN;
1182 static void hush_exit(int exitcode)
1184 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1185 /* Prevent recursion:
1186 * trap "echo Hi; exit" EXIT; exit
1188 char *argv[] = { NULL, G.traps[0], NULL };
1197 sigexit(- (exitcode & 0xff));
1203 static int check_and_run_traps(int sig)
1205 static const struct timespec zero_timespec = { 0, 0 };
1206 smalluint save_rcode;
1212 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1217 if (G.traps && G.traps[sig]) {
1218 if (G.traps[sig][0]) {
1219 /* We have user-defined handler */
1220 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1221 save_rcode = G.last_exitcode;
1224 G.last_exitcode = save_rcode;
1225 } /* else: "" trap, ignoring signal */
1228 /* not a trap: special action */
1230 #if ENABLE_HUSH_FAST
1233 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1237 /* Builtin was ^C'ed, make it look prettier: */
1244 /* bash is observed to signal whole process groups,
1245 * not individual processes */
1246 for (job = G.job_list; job; job = job->next) {
1249 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1250 if (kill(- job->pgrp, SIGHUP) == 0)
1251 kill(- job->pgrp, SIGCONT);
1256 default: /* ignored: */
1257 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1265 static const char *get_cwd(int force)
1267 if (force || G.cwd == NULL) {
1268 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1269 * we must not try to free(bb_msg_unknown) */
1270 if (G.cwd == bb_msg_unknown)
1272 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1274 G.cwd = bb_msg_unknown;
1281 * Shell and environment variable support
1283 static struct variable **get_ptr_to_local_var(const char *name)
1285 struct variable **pp;
1286 struct variable *cur;
1291 while ((cur = *pp) != NULL) {
1292 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1299 static struct variable *get_local_var(const char *name)
1301 struct variable **pp = get_ptr_to_local_var(name);
1307 static const char* FAST_FUNC get_local_var_value(const char *name)
1309 struct variable **pp = get_ptr_to_local_var(name);
1311 return strchr((*pp)->varstr, '=') + 1;
1312 if (strcmp(name, "PPID") == 0)
1313 return utoa(G.root_ppid);
1314 // bash compat: UID? EUID?
1315 #if ENABLE_HUSH_RANDOM_SUPPORT
1316 if (strcmp(name, "RANDOM") == 0) {
1317 return utoa(next_random(&G.random_gen));
1323 /* str holds "NAME=VAL" and is expected to be malloced.
1324 * We take ownership of it.
1326 * 0: do not change export flag
1327 * (if creating new variable, flag will be 0)
1328 * 1: set export flag and putenv the variable
1329 * -1: clear export flag and unsetenv the variable
1330 * flg_read_only is set only when we handle -R var=val
1332 #if !BB_MMU && ENABLE_HUSH_LOCAL
1333 /* all params are used */
1334 #elif BB_MMU && ENABLE_HUSH_LOCAL
1335 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1336 set_local_var(str, flg_export, local_lvl)
1337 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1338 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1339 set_local_var(str, flg_export)
1340 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1341 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1342 set_local_var(str, flg_export, flg_read_only)
1344 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1346 struct variable **var_pp;
1347 struct variable *cur;
1351 eq_sign = strchr(str, '=');
1352 if (!eq_sign) { /* not expected to ever happen? */
1357 name_len = eq_sign - str + 1; /* including '=' */
1358 var_pp = &G.top_var;
1359 while ((cur = *var_pp) != NULL) {
1360 if (strncmp(cur->varstr, str, name_len) != 0) {
1361 var_pp = &cur->next;
1364 /* We found an existing var with this name */
1365 if (cur->flg_read_only) {
1369 bb_error_msg("%s: readonly variable", str);
1373 if (flg_export == -1) { // "&& cur->flg_export" ?
1374 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1379 #if ENABLE_HUSH_LOCAL
1380 if (cur->func_nest_level < local_lvl) {
1381 /* New variable is declared as local,
1382 * and existing one is global, or local
1383 * from enclosing function.
1384 * Remove and save old one: */
1385 *var_pp = cur->next;
1386 cur->next = *G.shadowed_vars_pp;
1387 *G.shadowed_vars_pp = cur;
1388 /* bash 3.2.33(1) and exported vars:
1390 * # f() { local z=a; env | grep ^z; }
1396 if (cur->flg_export)
1401 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1406 if (cur->max_len != 0) {
1407 if (cur->max_len >= strlen(str)) {
1408 /* This one is from startup env, reuse space */
1409 strcpy(cur->varstr, str);
1413 /* max_len == 0 signifies "malloced" var, which we can
1414 * (and has to) free */
1418 goto set_str_and_exp;
1421 /* Not found - create new variable struct */
1422 cur = xzalloc(sizeof(*cur));
1423 #if ENABLE_HUSH_LOCAL
1424 cur->func_nest_level = local_lvl;
1426 cur->next = *var_pp;
1432 cur->flg_read_only = flg_read_only;
1435 if (flg_export == 1)
1436 cur->flg_export = 1;
1437 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1438 cmdedit_update_prompt();
1439 if (cur->flg_export) {
1440 if (flg_export == -1) {
1441 cur->flg_export = 0;
1442 /* unsetenv was already done */
1444 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1445 return putenv(cur->varstr);
1451 /* Used at startup and after each cd */
1452 static void set_pwd_var(int exp)
1454 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1455 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1458 static int unset_local_var_len(const char *name, int name_len)
1460 struct variable *cur;
1461 struct variable **var_pp;
1464 return EXIT_SUCCESS;
1465 var_pp = &G.top_var;
1466 while ((cur = *var_pp) != NULL) {
1467 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1468 if (cur->flg_read_only) {
1469 bb_error_msg("%s: readonly variable", name);
1470 return EXIT_FAILURE;
1472 *var_pp = cur->next;
1473 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1474 bb_unsetenv(cur->varstr);
1475 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1476 cmdedit_update_prompt();
1480 return EXIT_SUCCESS;
1482 var_pp = &cur->next;
1484 return EXIT_SUCCESS;
1487 static int unset_local_var(const char *name)
1489 return unset_local_var_len(name, strlen(name));
1492 static void unset_vars(char **strings)
1500 const char *eq = strchrnul(*v, '=');
1501 unset_local_var_len(*v, (int)(eq - *v));
1507 #if ENABLE_SH_MATH_SUPPORT
1508 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1509 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1510 static char* FAST_FUNC endofname(const char *name)
1518 if (!is_in_name(*p))
1525 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1527 char *var = xasprintf("%s=%s", name, val);
1528 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1533 * Helpers for "var1=val1 var2=val2 cmd" feature
1535 static void add_vars(struct variable *var)
1537 struct variable *next;
1541 var->next = G.top_var;
1543 if (var->flg_export) {
1544 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1545 putenv(var->varstr);
1547 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1553 static struct variable *set_vars_and_save_old(char **strings)
1556 struct variable *old = NULL;
1562 struct variable *var_p;
1563 struct variable **var_pp;
1566 eq = strchr(*s, '=');
1569 var_pp = get_ptr_to_local_var(*s);
1572 /* Remove variable from global linked list */
1574 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1575 *var_pp = var_p->next;
1576 /* Add it to returned list */
1580 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1591 static int FAST_FUNC static_get(struct in_str *i)
1600 static int FAST_FUNC static_peek(struct in_str *i)
1605 #if ENABLE_HUSH_INTERACTIVE
1607 static void cmdedit_update_prompt(void)
1609 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1610 G.PS1 = get_local_var_value("PS1");
1613 G.PS2 = get_local_var_value("PS2");
1621 static const char* setup_prompt_string(int promptmode)
1623 const char *prompt_str;
1624 debug_printf("setup_prompt_string %d ", promptmode);
1625 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1626 /* Set up the prompt */
1627 if (promptmode == 0) { /* PS1 */
1629 /* bash uses $PWD value, even if it is set by user.
1630 * It uses current dir only if PWD is unset.
1631 * We always use current dir. */
1632 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1637 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1638 debug_printf("result '%s'\n", prompt_str);
1642 static void get_user_input(struct in_str *i)
1645 const char *prompt_str;
1647 prompt_str = setup_prompt_string(i->promptmode);
1648 #if ENABLE_FEATURE_EDITING
1649 /* Enable command line editing only while a command line
1650 * is actually being read */
1653 /* buglet: SIGINT will not make new prompt to appear _at once_,
1654 * only after <Enter>. (^C will work) */
1655 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1656 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1657 check_and_run_traps(0);
1658 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1659 i->eof_flag = (r < 0);
1660 if (i->eof_flag) { /* EOF/error detected */
1661 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1662 G.user_input_buf[1] = '\0';
1667 fputs(prompt_str, stdout);
1669 G.user_input_buf[0] = r = fgetc(i->file);
1670 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1671 //do we need check_and_run_traps(0)? (maybe only if stdin)
1672 } while (G.flag_SIGINT);
1673 i->eof_flag = (r == EOF);
1675 i->p = G.user_input_buf;
1678 #endif /* INTERACTIVE */
1680 /* This is the magic location that prints prompts
1681 * and gets data back from the user */
1682 static int FAST_FUNC file_get(struct in_str *i)
1686 /* If there is data waiting, eat it up */
1687 if (i->p && *i->p) {
1688 #if ENABLE_HUSH_INTERACTIVE
1692 if (i->eof_flag && !*i->p)
1694 /* note: ch is never NUL */
1696 /* need to double check i->file because we might be doing something
1697 * more complicated by now, like sourcing or substituting. */
1698 #if ENABLE_HUSH_INTERACTIVE
1699 if (G_interactive_fd && i->promptme && i->file == stdin) {
1702 } while (!*i->p); /* need non-empty line */
1703 i->promptmode = 1; /* PS2 */
1708 do ch = fgetc(i->file); while (ch == '\0');
1710 debug_printf("file_get: got '%c' %d\n", ch, ch);
1711 #if ENABLE_HUSH_INTERACTIVE
1718 /* All callers guarantee this routine will never
1719 * be used right after a newline, so prompting is not needed.
1721 static int FAST_FUNC file_peek(struct in_str *i)
1724 if (i->p && *i->p) {
1725 if (i->eof_flag && !i->p[1])
1728 /* note: ch is never NUL */
1730 do ch = fgetc(i->file); while (ch == '\0');
1731 i->eof_flag = (ch == EOF);
1732 i->peek_buf[0] = ch;
1733 i->peek_buf[1] = '\0';
1735 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1739 static void setup_file_in_str(struct in_str *i, FILE *f)
1741 i->peek = file_peek;
1743 #if ENABLE_HUSH_INTERACTIVE
1745 i->promptmode = 0; /* PS1 */
1751 static void setup_string_in_str(struct in_str *i, const char *s)
1753 i->peek = static_peek;
1754 i->get = static_get;
1755 #if ENABLE_HUSH_INTERACTIVE
1757 i->promptmode = 0; /* PS1 */
1767 #define B_CHUNK (32 * sizeof(char*))
1769 static void o_reset_to_empty_unquoted(o_string *o)
1777 static void o_free(o_string *o)
1780 memset(o, 0, sizeof(*o));
1783 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1788 static void o_grow_by(o_string *o, int len)
1790 if (o->length + len > o->maxlen) {
1791 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1792 o->data = xrealloc(o->data, 1 + o->maxlen);
1796 static void o_addchr(o_string *o, int ch)
1798 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1800 o->data[o->length] = ch;
1802 o->data[o->length] = '\0';
1805 static void o_addblock(o_string *o, const char *str, int len)
1808 memcpy(&o->data[o->length], str, len);
1810 o->data[o->length] = '\0';
1814 static void o_addstr(o_string *o, const char *str)
1816 o_addblock(o, str, strlen(str));
1818 static void nommu_addchr(o_string *o, int ch)
1824 # define nommu_addchr(o, str) ((void)0)
1827 static void o_addstr_with_NUL(o_string *o, const char *str)
1829 o_addblock(o, str, strlen(str) + 1);
1832 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1837 && (*str != '*' && *str != '?' && *str != '[')
1845 #undef HUSH_BRACE_EXP
1847 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1848 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1849 * Apparently, on unquoted $v bash still does globbing
1850 * ("v='*.txt'; echo $v" prints all .txt files),
1851 * but NOT brace expansion! Thus, there should be TWO independent
1852 * quoting mechanisms on $v expansion side: one protects
1853 * $v from brace expansion, and other additionally protects "$v" against globbing.
1854 * We have only second one.
1857 #ifdef HUSH_BRACE_EXP
1858 # define MAYBE_BRACES "{}"
1860 # define MAYBE_BRACES ""
1863 /* My analysis of quoting semantics tells me that state information
1864 * is associated with a destination, not a source.
1866 static void o_addqchr(o_string *o, int ch)
1869 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1874 o->data[o->length] = '\\';
1877 o->data[o->length] = ch;
1879 o->data[o->length] = '\0';
1882 static void o_addQchr(o_string *o, int ch)
1885 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1887 o->data[o->length] = '\\';
1891 o->data[o->length] = ch;
1893 o->data[o->length] = '\0';
1896 static void o_addQstr(o_string *o, const char *str, int len)
1899 o_addblock(o, str, len);
1905 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1906 if (ordinary_cnt > len) /* paranoia */
1908 o_addblock(o, str, ordinary_cnt);
1909 if (ordinary_cnt == len)
1911 str += ordinary_cnt;
1912 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1916 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1918 o->data[o->length] = '\\';
1922 o->data[o->length] = ch;
1924 o->data[o->length] = '\0';
1928 /* A special kind of o_string for $VAR and `cmd` expansion.
1929 * It contains char* list[] at the beginning, which is grown in 16 element
1930 * increments. Actual string data starts at the next multiple of 16 * (char*).
1931 * list[i] contains an INDEX (int!) into this string data.
1932 * It means that if list[] needs to grow, data needs to be moved higher up
1933 * but list[i]'s need not be modified.
1934 * NB: remembering how many list[i]'s you have there is crucial.
1935 * o_finalize_list() operation post-processes this structure - calculates
1936 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1938 #if DEBUG_EXPAND || DEBUG_GLOB
1939 static void debug_print_list(const char *prefix, o_string *o, int n)
1941 char **list = (char**)o->data;
1942 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1946 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1947 prefix, list, n, string_start, o->length, o->maxlen);
1950 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1951 o->data + (int)list[i] + string_start,
1952 o->data + (int)list[i] + string_start);
1956 const char *p = o->data + (int)list[n - 1] + string_start;
1958 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1962 # define debug_print_list(prefix, o, n) ((void)0)
1965 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1966 * in list[n] so that it points past last stored byte so far.
1967 * It returns n+1. */
1968 static int o_save_ptr_helper(o_string *o, int n)
1970 char **list = (char**)o->data;
1974 if (!o->has_empty_slot) {
1975 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1976 string_len = o->length - string_start;
1977 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1978 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1979 /* list[n] points to string_start, make space for 16 more pointers */
1980 o->maxlen += 0x10 * sizeof(list[0]);
1981 o->data = xrealloc(o->data, o->maxlen + 1);
1982 list = (char**)o->data;
1983 memmove(list + n + 0x10, list + n, string_len);
1984 o->length += 0x10 * sizeof(list[0]);
1986 debug_printf_list("list[%d]=%d string_start=%d\n",
1987 n, string_len, string_start);
1990 /* We have empty slot at list[n], reuse without growth */
1991 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1992 string_len = o->length - string_start;
1993 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1994 n, string_len, string_start);
1995 o->has_empty_slot = 0;
1997 list[n] = (char*)(ptrdiff_t)string_len;
2001 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2002 static int o_get_last_ptr(o_string *o, int n)
2004 char **list = (char**)o->data;
2005 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2007 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2010 #ifdef HUSH_BRACE_EXP
2011 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2012 * first, it processes even {a} (no commas), second,
2013 * I didn't manage to make it return strings when they don't match
2014 * existing files. Need to re-implement it.
2018 static int glob_needed(const char *s)
2027 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2033 /* Return pointer to next closing brace or to comma */
2034 static const char *next_brace_sub(const char *cp)
2038 while (*cp != '\0') {
2045 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2047 if (*cp++ == '{') /*}*/
2051 return *cp != '\0' ? cp : NULL;
2053 /* Recursive brace globber. Note: may garble pattern[]. */
2054 static int glob_brace(char *pattern, o_string *o, int n)
2056 char *new_pattern_buf;
2063 debug_printf_glob("glob_brace('%s')\n", pattern);
2069 if (*begin == '{') /*}*/ {
2070 /* Find the first sub-pattern and at the same time
2071 * find the rest after the closing brace */
2072 next = next_brace_sub(begin);
2074 /* An illegal expression */
2077 /*{*/ if (*next == '}') {
2078 /* "{abc}" with no commas - illegal
2079 * brace expr, disregard and skip it */
2085 if (*begin == '\\' && begin[1] != '\0')
2089 debug_printf_glob("begin:%s\n", begin);
2090 debug_printf_glob("next:%s\n", next);
2092 /* Now find the end of the whole brace expression */
2094 /*{*/ while (*rest != '}') {
2095 rest = next_brace_sub(rest);
2097 /* An illegal expression */
2100 debug_printf_glob("rest:%s\n", rest);
2102 rest_len = strlen(++rest) + 1;
2104 /* We are sure the brace expression is well-formed */
2106 /* Allocate working buffer large enough for our work */
2107 new_pattern_buf = xmalloc(strlen(pattern));
2109 /* We have a brace expression. BEGIN points to the opening {,
2110 * NEXT points past the terminator of the first element, and REST
2111 * points past the final }. We will accumulate result names from
2112 * recursive runs for each brace alternative in the buffer using
2117 /* Construct the new glob expression */
2120 mempcpy(new_pattern_buf,
2121 /* We know the prefix for all sub-patterns */
2122 pattern, begin - pattern),
2126 /* Note: glob_brace() may garble new_pattern_buf[].
2127 * That's why we re-copy prefix every time (1st memcpy above).
2129 n = glob_brace(new_pattern_buf, o, n);
2130 /*{*/ if (*next == '}') {
2131 /* We saw the last entry */
2135 next = next_brace_sub(next);
2137 free(new_pattern_buf);
2145 memset(&globdata, 0, sizeof(globdata));
2146 gr = glob(pattern, 0, NULL, &globdata);
2147 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2149 if (gr == GLOB_NOMATCH) {
2150 globfree(&globdata);
2151 /* NB: garbles parameter */
2152 unbackslash(pattern);
2153 o_addstr_with_NUL(o, pattern);
2154 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2155 return o_save_ptr_helper(o, n);
2157 if (gr == GLOB_NOSPACE)
2158 bb_error_msg_and_die(bb_msg_memory_exhausted);
2159 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2160 * but we didn't specify it. Paranoia again. */
2161 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2163 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2164 char **argv = globdata.gl_pathv;
2166 o_addstr_with_NUL(o, *argv);
2167 n = o_save_ptr_helper(o, n);
2173 globfree(&globdata);
2177 /* Performs globbing on last list[],
2178 * saving each result as a new list[].
2180 static int o_glob(o_string *o, int n)
2182 char *pattern, *copy;
2184 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2186 return o_save_ptr_helper(o, n);
2187 pattern = o->data + o_get_last_ptr(o, n);
2188 debug_printf_glob("glob pattern '%s'\n", pattern);
2189 if (!glob_needed(pattern)) {
2190 /* unbackslash last string in o in place, fix length */
2191 o->length = unbackslash(pattern) - o->data;
2192 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2193 return o_save_ptr_helper(o, n);
2196 copy = xstrdup(pattern);
2197 /* "forget" pattern in o */
2198 o->length = pattern - o->data;
2199 n = glob_brace(copy, o, n);
2202 debug_print_list("o_glob returning", o, n);
2209 static int glob_needed(const char *s)
2218 if (*s == '*' || *s == '[' || *s == '?')
2224 /* Performs globbing on last list[],
2225 * saving each result as a new list[].
2227 static int o_glob(o_string *o, int n)
2233 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2235 return o_save_ptr_helper(o, n);
2236 pattern = o->data + o_get_last_ptr(o, n);
2237 debug_printf_glob("glob pattern '%s'\n", pattern);
2238 if (!glob_needed(pattern)) {
2240 /* unbackslash last string in o in place, fix length */
2241 o->length = unbackslash(pattern) - o->data;
2242 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2243 return o_save_ptr_helper(o, n);
2246 memset(&globdata, 0, sizeof(globdata));
2247 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2248 * If we glob "*.\*" and don't find anything, we need
2249 * to fall back to using literal "*.*", but GLOB_NOCHECK
2250 * will return "*.\*"!
2252 gr = glob(pattern, 0, NULL, &globdata);
2253 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2255 if (gr == GLOB_NOMATCH) {
2256 globfree(&globdata);
2259 if (gr == GLOB_NOSPACE)
2260 bb_error_msg_and_die(bb_msg_memory_exhausted);
2261 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2262 * but we didn't specify it. Paranoia again. */
2263 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2265 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2266 char **argv = globdata.gl_pathv;
2267 /* "forget" pattern in o */
2268 o->length = pattern - o->data;
2270 o_addstr_with_NUL(o, *argv);
2271 n = o_save_ptr_helper(o, n);
2277 globfree(&globdata);
2279 debug_print_list("o_glob returning", o, n);
2285 /* If o->o_glob == 1, glob the string so far remembered.
2286 * Otherwise, just finish current list[] and start new */
2287 static int o_save_ptr(o_string *o, int n)
2289 if (o->o_glob) { /* if globbing is requested */
2290 /* If o->has_empty_slot, list[n] was already globbed
2291 * (if it was requested back then when it was filled)
2292 * so don't do that again! */
2293 if (!o->has_empty_slot)
2294 return o_glob(o, n); /* o_save_ptr_helper is inside */
2296 return o_save_ptr_helper(o, n);
2299 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2300 static char **o_finalize_list(o_string *o, int n)
2305 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2307 debug_print_list("finalized", o, n);
2308 debug_printf_expand("finalized n:%d\n", n);
2309 list = (char**)o->data;
2310 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2314 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2320 /* Expansion can recurse */
2321 #if ENABLE_HUSH_TICK
2322 static int process_command_subs(o_string *dest, const char *s);
2324 static char *expand_string_to_string(const char *str);
2326 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2327 parse_stream_dquoted(dest, input, dquote_end)
2329 static int parse_stream_dquoted(o_string *as_string,
2331 struct in_str *input,
2334 /* expand_strvec_to_strvec() takes a list of strings, expands
2335 * all variable references within and returns a pointer to
2336 * a list of expanded strings, possibly with larger number
2337 * of strings. (Think VAR="a b"; echo $VAR).
2338 * This new list is allocated as a single malloc block.
2339 * NULL-terminated list of char* pointers is at the beginning of it,
2340 * followed by strings themself.
2341 * Caller can deallocate entire list by single free(list). */
2343 /* Store given string, finalizing the word and starting new one whenever
2344 * we encounter IFS char(s). This is used for expanding variable values.
2345 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2346 static int expand_on_ifs(o_string *output, int n, const char *str)
2349 int word_len = strcspn(str, G.ifs);
2351 if (output->o_escape || !output->o_glob)
2352 o_addQstr(output, str, word_len);
2353 else /* protect backslashes against globbing up :) */
2354 o_addblock_duplicate_backslash(output, str, word_len);
2357 if (!*str) /* EOL - do not finalize word */
2359 o_addchr(output, '\0');
2360 debug_print_list("expand_on_ifs", output, n);
2361 n = o_save_ptr(output, n);
2362 str += strspn(str, G.ifs); /* skip ifs chars */
2364 debug_print_list("expand_on_ifs[1]", output, n);
2368 /* Helper to expand $((...)) and heredoc body. These act as if
2369 * they are in double quotes, with the exception that they are not :).
2370 * Just the rules are similar: "expand only $var and `cmd`"
2372 * Returns malloced string.
2373 * As an optimization, we return NULL if expansion is not needed.
2375 static char *expand_pseudo_dquoted(const char *str)
2378 struct in_str input;
2379 o_string dest = NULL_O_STRING;
2381 if (strchr(str, '$') == NULL
2382 #if ENABLE_HUSH_TICK
2383 && strchr(str, '`') == NULL
2389 /* We need to expand. Example:
2390 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2392 setup_string_in_str(&input, str);
2393 parse_stream_dquoted(NULL, &dest, &input, EOF);
2394 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2395 exp_str = expand_string_to_string(dest.data);
2396 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2397 o_free_unsafe(&dest);
2401 /* Expand all variable references in given string, adding words to list[]
2402 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2403 * to be filled). This routine is extremely tricky: has to deal with
2404 * variables/parameters with whitespace, $* and $@, and constructs like
2405 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2406 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2408 /* or_mask is either 0 (normal case) or 0x80 -
2409 * expansion of right-hand side of assignment == 1-element expand.
2410 * It will also do no globbing, and thus we must not backslash-quote!
2417 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2418 debug_print_list("expand_vars_to_list", output, n);
2419 n = o_save_ptr(output, n);
2420 debug_print_list("expand_vars_to_list[0]", output, n);
2422 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2425 char *dyn_val = NULL;
2426 const char *val = NULL;
2427 #if ENABLE_HUSH_TICK
2428 o_string subst_result = NULL_O_STRING;
2430 #if ENABLE_SH_MATH_SUPPORT
2431 char arith_buf[sizeof(arith_t)*3 + 2];
2433 o_addblock(output, arg, p - arg);
2434 debug_print_list("expand_vars_to_list[1]", output, n);
2436 p = strchr(p, SPECIAL_VAR_SYMBOL);
2438 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2439 /* "$@" is special. Even if quoted, it can still
2440 * expand to nothing (not even an empty string) */
2441 if ((first_ch & 0x7f) != '@')
2442 ored_ch |= first_ch;
2444 switch (first_ch & 0x7f) {
2445 /* Highest bit in first_ch indicates that var is double-quoted */
2447 val = utoa(G.root_pid);
2449 case '!': /* bg pid */
2450 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2452 case '?': /* exitcode */
2453 val = utoa(G.last_exitcode);
2455 case '#': /* argc */
2456 if (arg[1] != SPECIAL_VAR_SYMBOL)
2457 /* actually, it's a ${#var} */
2459 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2464 if (!G.global_argv[i])
2466 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2467 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2468 smallint sv = output->o_escape;
2469 /* unquoted var's contents should be globbed, so don't escape */
2470 output->o_escape = 0;
2471 while (G.global_argv[i]) {
2472 n = expand_on_ifs(output, n, G.global_argv[i]);
2473 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2474 if (G.global_argv[i++][0] && G.global_argv[i]) {
2475 /* this argv[] is not empty and not last:
2476 * put terminating NUL, start new word */
2477 o_addchr(output, '\0');
2478 debug_print_list("expand_vars_to_list[2]", output, n);
2479 n = o_save_ptr(output, n);
2480 debug_print_list("expand_vars_to_list[3]", output, n);
2483 output->o_escape = sv;
2485 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2486 * and in this case should treat it like '$*' - see 'else...' below */
2487 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2489 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2490 if (++i >= G.global_argc)
2492 o_addchr(output, '\0');
2493 debug_print_list("expand_vars_to_list[4]", output, n);
2494 n = o_save_ptr(output, n);
2496 } else { /* quoted $*: add as one word */
2498 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2499 if (!G.global_argv[++i])
2502 o_addchr(output, G.ifs[0]);
2506 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2507 /* "Empty variable", used to make "" etc to not disappear */
2511 #if ENABLE_HUSH_TICK
2512 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2515 /* Can't just stuff it into output o_string,
2516 * expanded result may need to be globbed
2517 * and $IFS-splitted */
2518 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2519 G.last_exitcode = process_command_subs(&subst_result, arg);
2520 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2521 val = subst_result.data;
2524 #if ENABLE_SH_MATH_SUPPORT
2525 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2526 arith_eval_hooks_t hooks;
2531 arg++; /* skip '+' */
2532 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2533 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2535 exp_str = expand_pseudo_dquoted(arg);
2536 hooks.lookupvar = get_local_var_value;
2537 hooks.setvar = set_local_var_from_halves;
2538 hooks.endofname = endofname;
2539 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2543 const char *msg = "error in arithmetic";
2546 msg = "exponent less than 0";
2549 msg = "divide by 0";
2552 msg = "expression recursion loop detected";
2557 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2558 sprintf(arith_buf, arith_t_fmt, res);
2563 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2565 bool exp_len = false;
2566 bool exp_null = false;
2568 char exp_save = exp_save; /* for compiler */
2569 char exp_op = exp_op; /* for compiler */
2570 char *exp_word = exp_word; /* for compiler */
2574 arg[0] = first_ch & 0x7f;
2576 /* prepare for expansions */
2577 if (var[0] == '#') {
2578 /* handle length expansion ${#var} */
2582 /* maybe handle parameter expansion */
2583 exp_off = strcspn(var, ":-=+?%#");
2587 exp_save = var[exp_off];
2588 exp_null = exp_save == ':';
2589 exp_word = var + exp_off;
2592 exp_op = *exp_word++;
2593 var[exp_off] = '\0';
2597 /* lookup the variable in question */
2598 if (isdigit(var[0])) {
2599 /* handle_dollar() should have vetted var for us */
2601 if (i < G.global_argc)
2602 val = G.global_argv[i];
2603 /* else val remains NULL: $N with too big N */
2605 val = get_local_var_value(var);
2607 /* handle any expansions */
2609 debug_printf_expand("expand: length of '%s' = ", val);
2610 val = utoa(val ? strlen(val) : 0);
2611 debug_printf_expand("%s\n", val);
2612 } else if (exp_off) {
2613 if (exp_op == '%' || exp_op == '#') {
2615 /* we need to do a pattern match */
2618 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2619 if (exp_op == *exp_word) /* ## or %% */
2621 val = dyn_val = xstrdup(val);
2622 loc = scan(dyn_val, exp_word, match_at_left);
2623 if (match_at_left) /* # or ## */
2625 else if (loc) /* % or %% and match was found */
2629 /* we need to do an expansion */
2630 int exp_test = (!val || (exp_null && !val[0]));
2632 exp_test = !exp_test;
2633 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2634 exp_null ? "true" : "false", exp_test);
2636 if (exp_op == '?') {
2637 //TODO: how interactive bash aborts expansion mid-command?
2638 /* ${var?[error_msg_if_unset]} */
2639 /* ${var:?[error_msg_if_unset_or_null]} */
2640 /* mimic bash message */
2641 die_if_script("%s: %s",
2643 exp_word[0] ? exp_word : "parameter null or not set"
2649 if (exp_op == '=') {
2650 /* ${var=[word]} or ${var:=[word]} */
2651 if (isdigit(var[0]) || var[0] == '#') {
2652 /* mimic bash message */
2653 die_if_script("$%s: cannot assign in this way", var);
2656 char *new_var = xasprintf("%s=%s", var, val);
2657 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2663 var[exp_off] = exp_save;
2667 #if ENABLE_HUSH_TICK
2670 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2671 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2673 /* unquoted var's contents should be globbed, so don't escape */
2674 smallint sv = output->o_escape;
2675 output->o_escape = 0;
2676 n = expand_on_ifs(output, n, val);
2678 output->o_escape = sv;
2680 } else { /* quoted $VAR, val will be appended below */
2681 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2684 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2687 o_addQstr(output, val, strlen(val));
2690 /* Do the check to avoid writing to a const string */
2691 if (*p != SPECIAL_VAR_SYMBOL)
2692 *p = SPECIAL_VAR_SYMBOL;
2694 #if ENABLE_HUSH_TICK
2695 o_free(&subst_result);
2698 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2701 debug_print_list("expand_vars_to_list[a]", output, n);
2702 /* this part is literal, and it was already pre-quoted
2703 * if needed (much earlier), do not use o_addQstr here! */
2704 o_addstr_with_NUL(output, arg);
2705 debug_print_list("expand_vars_to_list[b]", output, n);
2706 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2707 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2710 /* allow to reuse list[n] later without re-growth */
2711 output->has_empty_slot = 1;
2713 o_addchr(output, '\0');
2718 static char **expand_variables(char **argv, int or_mask)
2723 o_string output = NULL_O_STRING;
2725 if (or_mask & 0x100) {
2726 output.o_escape = 1; /* protect against globbing for "$var" */
2727 /* (unquoted $var will temporarily switch it off) */
2734 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2737 debug_print_list("expand_variables", &output, n);
2739 /* output.data (malloced in one block) gets returned in "list" */
2740 list = o_finalize_list(&output, n);
2741 debug_print_strings("expand_variables[1]", list);
2745 static char **expand_strvec_to_strvec(char **argv)
2747 return expand_variables(argv, 0x100);
2750 #if ENABLE_HUSH_BASH_COMPAT
2751 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2753 return expand_variables(argv, 0x80);
2757 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2758 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2763 o_string output = NULL_O_STRING;
2768 int is_var = is_well_formed_var_name(*v, '=');
2769 /* is_var * 0x80: singleword expansion for vars */
2770 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2772 /* Subtle! expand_vars_to_list did not glob last word yet.
2773 * It does this only when fed with further data.
2774 * Therefore we set globbing flags AFTER it, not before:
2777 /* if it is not recognizably abc=...; then: */
2778 output.o_escape = !is_var; /* protect against globbing for "$var" */
2779 /* (unquoted $var will temporarily switch it off) */
2780 output.o_glob = !is_var; /* and indeed do globbing */
2783 debug_print_list("expand_cond", &output, n);
2785 /* output.data (malloced in one block) gets returned in "list" */
2786 list = o_finalize_list(&output, n);
2787 debug_print_strings("expand_cond[1]", list);
2792 /* Used for expansion of right hand of assignments */
2793 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2795 static char *expand_string_to_string(const char *str)
2797 char *argv[2], **list;
2799 argv[0] = (char*)str;
2801 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2803 if (!list[0] || list[1])
2804 bb_error_msg_and_die("BUG in varexp2");
2805 /* actually, just move string 2*sizeof(char*) bytes back */
2806 overlapping_strcpy((char*)list, list[0]);
2807 unbackslash((char*)list);
2808 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2812 /* Used for "eval" builtin */
2813 static char* expand_strvec_to_string(char **argv)
2817 list = expand_variables(argv, 0x80);
2818 /* Convert all NULs to spaces */
2823 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2824 bb_error_msg_and_die("BUG in varexp3");
2825 /* bash uses ' ' regardless of $IFS contents */
2830 overlapping_strcpy((char*)list, list[0]);
2831 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2835 static char **expand_assignments(char **argv, int count)
2839 /* Expand assignments into one string each */
2840 for (i = 0; i < count; i++) {
2841 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2849 void re_execute_shell(char ***to_free, const char *s,
2850 char *g_argv0, char **g_argv,
2851 char **builtin_argv) NORETURN;
2853 static void reset_traps_to_defaults(void)
2855 /* This function is always called in a child shell
2856 * after fork (not vfork, NOMMU doesn't use this function).
2861 /* Child shells are not interactive.
2862 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2863 * Testcase: (while :; do :; done) + ^Z should background.
2864 * Same goes for SIGTERM, SIGHUP, SIGINT.
2866 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2867 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2869 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2870 * Stupid. It can be done with *single* &= op, but we can't use
2871 * the fact that G.blocked_set is implemented as a bitmask
2873 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2877 /* Careful. Only if no trap or trap is not "" */
2878 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2879 sigdelset(&G.blocked_set, sig);
2886 /* Our homegrown sig mask is saner to work with :) */
2887 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2889 /* Resetting all traps to default except empty ones */
2890 mask = G.non_DFL_mask;
2891 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2892 if (!G.traps[sig] || !G.traps[sig][0])
2895 G.traps[sig] = NULL;
2896 /* There is no signal for 0 (EXIT) */
2899 /* There was a trap handler, we just removed it.
2900 * But if sig still has non-DFL handling,
2901 * we should not unblock the sig. */
2904 sigdelset(&G.blocked_set, sig);
2906 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2911 static void re_execute_shell(char ***to_free, const char *s,
2912 char *g_argv0, char **g_argv,
2913 char **builtin_argv) NORETURN;
2914 static void re_execute_shell(char ***to_free, const char *s,
2915 char *g_argv0, char **g_argv,
2916 char **builtin_argv)
2918 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
2919 /* delims + 2 * (number of bytes in printed hex numbers) */
2920 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
2921 char *heredoc_argv[4];
2922 struct variable *cur;
2923 # if ENABLE_HUSH_FUNCTIONS
2924 struct function *funcp;
2928 unsigned long long empty_trap_mask;
2930 if (!g_argv0) { /* heredoc */
2931 argv = heredoc_argv;
2932 argv[0] = (char *) G.argv0_for_re_execing;
2933 argv[1] = (char *) "-<";
2934 argv[2] = (char *) s;
2936 pp = &argv[3]; /* used as pointer to empty environment */
2942 if (pp) while (*pp++)
2945 empty_trap_mask = 0;
2948 for (sig = 1; sig < NSIG; sig++) {
2949 if (G.traps[sig] && !G.traps[sig][0])
2950 empty_trap_mask |= 1LL << sig;
2954 sprintf(param_buf, NOMMU_HACK_FMT
2955 , (unsigned) G.root_pid
2956 , (unsigned) G.root_ppid
2957 , (unsigned) G.last_bg_pid
2958 , (unsigned) G.last_exitcode
2961 IF_HUSH_LOOPS(, G.depth_of_loop)
2963 #undef NOMMU_HACK_FMT
2964 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
2965 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2968 for (cur = G.top_var; cur; cur = cur->next) {
2969 if (!cur->flg_export || cur->flg_read_only)
2972 # if ENABLE_HUSH_FUNCTIONS
2973 for (funcp = G.top_func; funcp; funcp = funcp->next)
2979 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2980 *pp++ = (char *) G.argv0_for_re_execing;
2982 for (cur = G.top_var; cur; cur = cur->next) {
2983 if (cur->varstr == hush_version_str)
2985 if (cur->flg_read_only) {
2986 *pp++ = (char *) "-R";
2987 *pp++ = cur->varstr;
2988 } else if (!cur->flg_export) {
2989 *pp++ = (char *) "-V";
2990 *pp++ = cur->varstr;
2993 # if ENABLE_HUSH_FUNCTIONS
2994 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2995 *pp++ = (char *) "-F";
2996 *pp++ = funcp->name;
2997 *pp++ = funcp->body_as_string;
3000 /* We can pass activated traps here. Say, -Tnn:trap_string
3002 * However, POSIX says that subshells reset signals with traps
3004 * I tested bash-3.2 and it not only does that with true subshells
3005 * of the form ( list ), but with any forked children shells.
3006 * I set trap "echo W" WINCH; and then tried:
3008 * { echo 1; sleep 20; echo 2; } &
3009 * while true; do echo 1; sleep 20; echo 2; break; done &
3010 * true | { echo 1; sleep 20; echo 2; } | cat
3012 * In all these cases sending SIGWINCH to the child shell
3013 * did not run the trap. If I add trap "echo V" WINCH;
3014 * _inside_ group (just before echo 1), it works.
3016 * I conclude it means we don't need to pass active traps here.
3017 * Even if we would use signal handlers instead of signal masking
3018 * in order to implement trap handling,
3019 * exec syscall below resets signals to SIG_DFL for us.
3021 *pp++ = (char *) "-c";
3024 while (*++builtin_argv)
3025 *pp++ = *builtin_argv;
3026 *pp++ = (char *) "";
3031 /* *pp = NULL; - is already there */
3035 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3036 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3037 execve(bb_busybox_exec_path, argv, pp);
3038 /* Fallback. Useful for init=/bin/hush usage etc */
3039 if (argv[0][0] == '/')
3040 execve(argv[0], argv, pp);
3041 xfunc_error_retval = 127;
3042 bb_error_msg_and_die("can't re-execute the shell");
3044 #endif /* !BB_MMU */
3047 static void setup_heredoc(struct redir_struct *redir)
3049 struct fd_pair pair;
3052 /* the _body_ of heredoc (misleading field name) */
3053 const char *heredoc = redir->rd_filename;
3060 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3061 expanded = expand_pseudo_dquoted(heredoc);
3065 len = strlen(heredoc);
3067 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3069 xmove_fd(pair.rd, redir->rd_fd);
3071 /* Try writing without forking. Newer kernels have
3072 * dynamically growing pipes. Must use non-blocking write! */
3075 written = write(pair.wr, heredoc, len);
3086 ndelay_off(pair.wr);
3088 /* Okay, pipe buffer was not big enough */
3089 /* Note: we must not create a stray child (bastard? :)
3090 * for the unsuspecting parent process. Child creates a grandchild
3091 * and exits before parent execs the process which consumes heredoc
3092 * (that exec happens after we return from this function) */
3098 bb_perror_msg_and_die("vfork");
3101 disable_restore_tty_pgrp_on_exit();
3102 pid = BB_MMU ? fork() : vfork();
3104 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3108 close(redir->rd_fd); /* read side of the pipe */
3110 full_write(pair.wr, heredoc, len); /* may loop or block */
3113 /* Delegate blocking writes to another process */
3114 xmove_fd(pair.wr, STDOUT_FILENO);
3115 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3119 #if ENABLE_HUSH_FAST
3121 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3123 enable_restore_tty_pgrp_on_exit();
3129 wait(NULL); /* wait till child has died */
3132 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3133 * and stderr if they are redirected. */
3134 static int setup_redirects(struct command *prog, int squirrel[])
3137 struct redir_struct *redir;
3139 for (redir = prog->redirects; redir; redir = redir->next) {
3140 if (redir->rd_type == REDIRECT_HEREDOC2) {
3141 /* rd_fd<<HERE case */
3142 if (squirrel && redir->rd_fd < 3
3143 && squirrel[redir->rd_fd] < 0
3145 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3147 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3149 debug_printf_parse("set heredoc '%s'\n",
3150 redir->rd_filename);
3151 setup_heredoc(redir);
3155 if (redir->rd_dup == REDIRFD_TO_FILE) {
3156 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3158 if (redir->rd_filename == NULL) {
3159 /* Something went wrong in the parse.
3160 * Pretend it didn't happen */
3161 bb_error_msg("bug in redirect parse");
3164 mode = redir_table[redir->rd_type].mode;
3165 p = expand_string_to_string(redir->rd_filename);
3166 openfd = open_or_warn(p, mode);
3169 /* this could get lost if stderr has been redirected, but
3170 * bash and ash both lose it as well (though zsh doesn't!) */
3171 //what the above comment tries to say?
3175 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3176 openfd = redir->rd_dup;
3179 if (openfd != redir->rd_fd) {
3180 if (squirrel && redir->rd_fd < 3
3181 && squirrel[redir->rd_fd] < 0
3183 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3185 if (openfd == REDIRFD_CLOSE) {
3186 /* "n>-" means "close me" */
3187 close(redir->rd_fd);
3189 xdup2(openfd, redir->rd_fd);
3190 if (redir->rd_dup == REDIRFD_TO_FILE)
3198 static void restore_redirects(int squirrel[])
3201 for (i = 0; i < 3; i++) {
3204 /* We simply die on error */
3211 static void free_pipe_list(struct pipe *head);
3213 /* Return code is the exit status of the pipe */
3214 static void free_pipe(struct pipe *pi)
3217 struct command *command;
3218 struct redir_struct *r, *rnext;
3221 if (pi->stopped_cmds > 0) /* why? */
3223 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3224 for (i = 0; i < pi->num_cmds; i++) {
3225 command = &pi->cmds[i];
3226 debug_printf_clean(" command %d:\n", i);
3227 if (command->argv) {
3228 for (a = 0, p = command->argv; *p; a++, p++) {
3229 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3231 free_strings(command->argv);
3232 command->argv = NULL;
3234 /* not "else if": on syntax error, we may have both! */
3235 if (command->group) {
3236 debug_printf_clean(" begin group (cmd_type:%d)\n",
3238 free_pipe_list(command->group);
3239 debug_printf_clean(" end group\n");
3240 command->group = NULL;
3242 /* else is crucial here.
3243 * If group != NULL, child_func is meaningless */
3244 #if ENABLE_HUSH_FUNCTIONS
3245 else if (command->child_func) {
3246 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3247 command->child_func->parent_cmd = NULL;
3251 free(command->group_as_string);
3252 command->group_as_string = NULL;
3254 for (r = command->redirects; r; r = rnext) {
3255 debug_printf_clean(" redirect %d%s",
3256 r->rd_fd, redir_table[r->rd_type].descrip);
3257 /* guard against the case >$FOO, where foo is unset or blank */
3258 if (r->rd_filename) {
3259 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3260 free(r->rd_filename);
3261 r->rd_filename = NULL;
3263 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3267 command->redirects = NULL;
3269 free(pi->cmds); /* children are an array, they get freed all at once */
3277 static void free_pipe_list(struct pipe *head)
3279 struct pipe *pi, *next;
3281 for (pi = head; pi; pi = next) {
3283 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3286 debug_printf_clean("pipe followup code %d\n", pi->followup);
3288 /*pi->next = NULL;*/
3294 static int run_list(struct pipe *pi);
3296 #define parse_stream(pstring, input, end_trigger) \
3297 parse_stream(input, end_trigger)
3299 static struct pipe *parse_stream(char **pstring,
3300 struct in_str *input,
3302 static void parse_and_run_string(const char *s);
3305 static char *find_in_path(const char *arg)
3308 const char *PATH = get_local_var_value("PATH");
3314 const char *end = strchrnul(PATH, ':');
3315 int sz = end - PATH; /* must be int! */
3319 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3321 /* We have xxx::yyyy in $PATH,
3322 * it means "use current dir" */
3325 if (access(ret, F_OK) == 0)
3338 static const struct built_in_command* find_builtin_helper(const char *name,
3339 const struct built_in_command *x,
3340 const struct built_in_command *end)
3343 if (strcmp(name, x->b_cmd) != 0) {
3347 debug_printf_exec("found builtin '%s'\n", name);
3352 static const struct built_in_command* find_builtin1(const char *name)
3354 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3356 static const struct built_in_command* find_builtin(const char *name)
3358 const struct built_in_command *x = find_builtin1(name);
3361 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3364 #if ENABLE_HUSH_FUNCTIONS
3365 static struct function **find_function_slot(const char *name)
3367 struct function **funcpp = &G.top_func;
3369 if (strcmp(name, (*funcpp)->name) == 0) {
3372 funcpp = &(*funcpp)->next;
3377 static const struct function *find_function(const char *name)
3379 const struct function *funcp = *find_function_slot(name);
3381 debug_printf_exec("found function '%s'\n", name);
3385 /* Note: takes ownership on name ptr */
3386 static struct function *new_function(char *name)
3388 struct function **funcpp = find_function_slot(name);
3389 struct function *funcp = *funcpp;
3391 if (funcp != NULL) {
3392 struct command *cmd = funcp->parent_cmd;
3393 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3395 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3397 /* Note: if !funcp->body, do not free body_as_string!
3398 * This is a special case of "-F name body" function:
3399 * body_as_string was not malloced! */
3401 free_pipe_list(funcp->body);
3403 free(funcp->body_as_string);
3407 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3408 cmd->argv[0] = funcp->name;
3409 cmd->group = funcp->body;
3411 cmd->group_as_string = funcp->body_as_string;
3415 debug_printf_exec("remembering new function '%s'\n", name);
3416 funcp = *funcpp = xzalloc(sizeof(*funcp));
3417 /*funcp->next = NULL;*/
3424 static void unset_func(const char *name)
3426 struct function **funcpp = find_function_slot(name);
3427 struct function *funcp = *funcpp;
3429 if (funcp != NULL) {
3430 debug_printf_exec("freeing function '%s'\n", funcp->name);
3431 *funcpp = funcp->next;
3432 /* funcp is unlinked now, deleting it.
3433 * Note: if !funcp->body, the function was created by
3434 * "-F name body", do not free ->body_as_string
3435 * and ->name as they were not malloced. */
3437 free_pipe_list(funcp->body);
3440 free(funcp->body_as_string);
3448 #define exec_function(to_free, funcp, argv) \
3449 exec_function(funcp, argv)
3451 static void exec_function(char ***to_free,
3452 const struct function *funcp,
3453 char **argv) NORETURN;
3454 static void exec_function(char ***to_free,
3455 const struct function *funcp,
3461 argv[0] = G.global_argv[0];
3462 G.global_argv = argv;
3466 /* On MMU, funcp->body is always non-NULL */
3467 n = run_list(funcp->body);
3471 re_execute_shell(to_free,
3472 funcp->body_as_string,
3479 static int run_function(const struct function *funcp, char **argv)
3485 save_and_replace_G_args(&sv, argv);
3487 /* "we are in function, ok to use return" */
3488 sv_flg = G.flag_return_in_progress;
3489 G.flag_return_in_progress = -1;
3490 # if ENABLE_HUSH_LOCAL
3491 G.func_nest_level++;
3494 /* On MMU, funcp->body is always non-NULL */
3497 /* Function defined by -F */
3498 parse_and_run_string(funcp->body_as_string);
3499 rc = G.last_exitcode;
3503 rc = run_list(funcp->body);
3506 # if ENABLE_HUSH_LOCAL
3508 struct variable *var;
3509 struct variable **var_pp;
3511 var_pp = &G.top_var;
3512 while ((var = *var_pp) != NULL) {
3513 if (var->func_nest_level < G.func_nest_level) {
3514 var_pp = &var->next;
3518 if (var->flg_export)
3519 bb_unsetenv(var->varstr);
3520 /* Remove from global list */
3521 *var_pp = var->next;
3527 G.func_nest_level--;
3530 G.flag_return_in_progress = sv_flg;
3532 restore_G_args(&sv, argv);
3536 #endif /* ENABLE_HUSH_FUNCTIONS */
3540 #define exec_builtin(to_free, x, argv) \
3541 exec_builtin(x, argv)
3543 #define exec_builtin(to_free, x, argv) \
3544 exec_builtin(to_free, argv)
3546 static void exec_builtin(char ***to_free,
3547 const struct built_in_command *x,
3548 char **argv) NORETURN;
3549 static void exec_builtin(char ***to_free,
3550 const struct built_in_command *x,
3554 int rcode = x->b_function(argv);
3558 /* On NOMMU, we must never block!
3559 * Example: { sleep 99 | read line; } & echo Ok
3561 re_execute_shell(to_free,
3570 static void execvp_or_die(char **argv) NORETURN;
3571 static void execvp_or_die(char **argv)
3573 debug_printf_exec("execing '%s'\n", argv[0]);
3574 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3575 execvp(argv[0], argv);
3576 bb_perror_msg("can't execute '%s'", argv[0]);
3577 _exit(127); /* bash compat */
3581 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3582 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3583 #define pseudo_exec(nommu_save, command, argv_expanded) \
3584 pseudo_exec(command, argv_expanded)
3587 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3589 * Don't exit() here. If you don't exec, use _exit instead.
3590 * The at_exit handlers apparently confuse the calling process,
3591 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3592 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3593 char **argv, int assignment_cnt,
3594 char **argv_expanded) NORETURN;
3595 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3596 char **argv, int assignment_cnt,
3597 char **argv_expanded)
3601 /* Case when we are here: ... | var=val | ... */
3602 if (!argv[assignment_cnt])
3603 _exit(EXIT_SUCCESS);
3605 new_env = expand_assignments(argv, assignment_cnt);
3607 set_vars_and_save_old(new_env);
3608 free(new_env); /* optional */
3609 /* we can also destroy set_vars_and_save_old's return value,
3612 nommu_save->new_env = new_env;
3613 nommu_save->old_vars = set_vars_and_save_old(new_env);
3615 if (argv_expanded) {
3616 argv = argv_expanded;
3618 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3620 nommu_save->argv = argv;
3624 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3625 if (strchr(argv[0], '/') != NULL)
3629 /* Check if the command matches any of the builtins.
3630 * Depending on context, this might be redundant. But it's
3631 * easier to waste a few CPU cycles than it is to figure out
3632 * if this is one of those cases.
3635 /* On NOMMU, it is more expensive to re-execute shell
3636 * just in order to run echo or test builtin.
3637 * It's better to skip it here and run corresponding
3638 * non-builtin later. */
3639 const struct built_in_command *x;
3640 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3642 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3645 #if ENABLE_HUSH_FUNCTIONS
3646 /* Check if the command matches any functions */
3648 const struct function *funcp = find_function(argv[0]);
3650 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3655 #if ENABLE_FEATURE_SH_STANDALONE
3656 /* Check if the command matches any busybox applets */
3658 int a = find_applet_by_name(argv[0]);
3660 # if BB_MMU /* see above why on NOMMU it is not allowed */
3661 if (APPLET_IS_NOEXEC(a)) {
3662 debug_printf_exec("running applet '%s'\n", argv[0]);
3663 run_applet_no_and_exit(a, argv);
3666 /* Re-exec ourselves */
3667 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3668 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3669 execv(bb_busybox_exec_path, argv);
3670 /* If they called chroot or otherwise made the binary no longer
3671 * executable, fall through */
3676 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3679 execvp_or_die(argv);
3682 /* Called after [v]fork() in run_pipe
3684 static void pseudo_exec(nommu_save_t *nommu_save,
3685 struct command *command,
3686 char **argv_expanded) NORETURN;
3687 static void pseudo_exec(nommu_save_t *nommu_save,
3688 struct command *command,
3689 char **argv_expanded)
3691 if (command->argv) {
3692 pseudo_exec_argv(nommu_save, command->argv,
3693 command->assignment_cnt, argv_expanded);
3696 if (command->group) {
3697 /* Cases when we are here:
3700 * ... | ( list ) | ...
3701 * ... | { list } | ...
3705 debug_printf_exec("pseudo_exec: run_list\n");
3706 reset_traps_to_defaults();
3707 rcode = run_list(command->group);
3708 /* OK to leak memory by not calling free_pipe_list,
3709 * since this process is about to exit */
3712 re_execute_shell(&nommu_save->argv_from_re_execing,
3713 command->group_as_string,
3720 /* Case when we are here: ... | >file */
3721 debug_printf_exec("pseudo_exec'ed null command\n");
3722 _exit(EXIT_SUCCESS);
3726 static const char *get_cmdtext(struct pipe *pi)
3732 /* This is subtle. ->cmdtext is created only on first backgrounding.
3733 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3734 * On subsequent bg argv is trashed, but we won't use it */
3737 argv = pi->cmds[0].argv;
3738 if (!argv || !argv[0]) {
3739 pi->cmdtext = xzalloc(1);
3745 len += strlen(*argv) + 1;
3749 argv = pi->cmds[0].argv;
3751 len = strlen(*argv);
3752 memcpy(p, *argv, len);
3760 static void insert_bg_job(struct pipe *pi)
3762 struct pipe *job, **jobp;
3765 /* Linear search for the ID of the job to use */
3767 for (job = G.job_list; job; job = job->next)
3768 if (job->jobid >= pi->jobid)
3769 pi->jobid = job->jobid + 1;
3771 /* Add job to the list of running jobs */
3773 while ((job = *jobp) != NULL)
3775 job = *jobp = xmalloc(sizeof(*job));
3777 *job = *pi; /* physical copy */
3779 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3780 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3781 for (i = 0; i < pi->num_cmds; i++) {
3782 job->cmds[i].pid = pi->cmds[i].pid;
3783 /* all other fields are not used and stay zero */
3785 job->cmdtext = xstrdup(get_cmdtext(pi));
3787 if (G_interactive_fd)
3788 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3789 /* Last command's pid goes to $! */
3790 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3791 G.last_jobid = job->jobid;
3794 static void remove_bg_job(struct pipe *pi)
3796 struct pipe *prev_pipe;
3798 if (pi == G.job_list) {
3799 G.job_list = pi->next;
3801 prev_pipe = G.job_list;
3802 while (prev_pipe->next != pi)
3803 prev_pipe = prev_pipe->next;
3804 prev_pipe->next = pi->next;
3807 G.last_jobid = G.job_list->jobid;
3812 /* Remove a backgrounded job */
3813 static void delete_finished_bg_job(struct pipe *pi)
3816 pi->stopped_cmds = 0;
3822 /* Check to see if any processes have exited -- if they
3823 * have, figure out why and see if a job has completed */
3824 static int checkjobs(struct pipe* fg_pipe)
3834 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3836 attributes = WUNTRACED;
3837 if (fg_pipe == NULL)
3838 attributes |= WNOHANG;
3841 #if ENABLE_HUSH_FAST
3842 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3843 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3844 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3845 /* There was neither fork nor SIGCHLD since last waitpid */
3846 /* Avoid doing waitpid syscall if possible */
3847 if (!G.we_have_children) {
3851 if (fg_pipe == NULL) { /* is WNOHANG set? */
3852 /* We have children, but they did not exit
3853 * or stop yet (we saw no SIGCHLD) */
3856 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3860 /* Do we do this right?
3861 * bash-3.00# sleep 20 | false
3863 * [3]+ Stopped sleep 20 | false
3864 * bash-3.00# echo $?
3865 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3866 * [hush 1.14.0: yes we do it right]
3873 #if ENABLE_HUSH_FAST
3874 i = G.count_SIGCHLD;
3876 childpid = waitpid(-1, &status, attributes);
3877 if (childpid <= 0) {
3878 if (childpid && errno != ECHILD)
3879 bb_perror_msg("waitpid");
3880 #if ENABLE_HUSH_FAST
3881 else { /* Until next SIGCHLD, waitpid's are useless */
3882 G.we_have_children = (childpid == 0);
3883 G.handled_SIGCHLD = i;
3884 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3889 dead = WIFEXITED(status) || WIFSIGNALED(status);
3892 if (WIFSTOPPED(status))
3893 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3894 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3895 if (WIFSIGNALED(status))
3896 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3897 childpid, WTERMSIG(status), WEXITSTATUS(status));
3898 if (WIFEXITED(status))
3899 debug_printf_jobs("pid %d exited, exitcode %d\n",
3900 childpid, WEXITSTATUS(status));
3902 /* Were we asked to wait for fg pipe? */
3904 for (i = 0; i < fg_pipe->num_cmds; i++) {
3905 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3906 if (fg_pipe->cmds[i].pid != childpid)
3909 fg_pipe->cmds[i].pid = 0;
3910 fg_pipe->alive_cmds--;
3911 if (i == fg_pipe->num_cmds - 1) {
3912 /* last process gives overall exitstatus */
3913 rcode = WEXITSTATUS(status);
3914 /* bash prints killer signal's name for *last*
3915 * process in pipe (prints just newline for SIGINT).
3916 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3918 if (WIFSIGNALED(status)) {
3919 int sig = WTERMSIG(status);
3920 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3921 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
3922 * Maybe we need to use sig | 128? */
3925 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3928 fg_pipe->cmds[i].is_stopped = 1;
3929 fg_pipe->stopped_cmds++;
3931 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3932 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3933 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3934 /* All processes in fg pipe have exited or stopped */
3935 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3936 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3937 * and "killall -STOP cat" */
3938 if (G_interactive_fd) {
3940 if (fg_pipe->alive_cmds)
3941 insert_bg_job(fg_pipe);
3945 if (!fg_pipe->alive_cmds)
3948 /* There are still running processes in the fg pipe */
3949 goto wait_more; /* do waitpid again */
3951 /* it wasnt fg_pipe, look for process in bg pipes */
3955 /* We asked to wait for bg or orphaned children */
3956 /* No need to remember exitcode in this case */
3957 for (pi = G.job_list; pi; pi = pi->next) {
3958 for (i = 0; i < pi->num_cmds; i++) {
3959 if (pi->cmds[i].pid == childpid)
3960 goto found_pi_and_prognum;
3963 /* Happens when shell is used as init process (init=/bin/sh) */
3964 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3965 continue; /* do waitpid again */
3967 found_pi_and_prognum:
3970 pi->cmds[i].pid = 0;
3972 if (!pi->alive_cmds) {
3973 if (G_interactive_fd)
3974 printf(JOB_STATUS_FORMAT, pi->jobid,
3975 "Done", pi->cmdtext);
3976 delete_finished_bg_job(pi);
3980 pi->cmds[i].is_stopped = 1;
3984 } /* while (waitpid succeeds)... */
3990 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3993 int rcode = checkjobs(fg_pipe);
3994 if (G_saved_tty_pgrp) {
3995 /* Job finished, move the shell to the foreground */
3996 p = getpgrp(); /* our process group id */
3997 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3998 tcsetpgrp(G_interactive_fd, p);
4004 /* Start all the jobs, but don't wait for anything to finish.
4007 * Return code is normally -1, when the caller has to wait for children
4008 * to finish to determine the exit status of the pipe. If the pipe
4009 * is a simple builtin command, however, the action is done by the
4010 * time run_pipe returns, and the exit code is provided as the
4013 * Returns -1 only if started some children. IOW: we have to
4014 * mask out retvals of builtins etc with 0xff!
4016 * The only case when we do not need to [v]fork is when the pipe
4017 * is single, non-backgrounded, non-subshell command. Examples:
4018 * cmd ; ... { list } ; ...
4019 * cmd && ... { list } && ...
4020 * cmd || ... { list } || ...
4021 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4022 * or (if SH_STANDALONE) an applet, and we can run the { list }
4023 * with run_list. If it isn't one of these, we fork and exec cmd.
4025 * Cases when we must fork:
4026 * non-single: cmd | cmd
4027 * backgrounded: cmd & { list } &
4028 * subshell: ( list ) [&]
4030 static NOINLINE int run_pipe(struct pipe *pi)
4032 static const char *const null_ptr = NULL;
4035 struct command *command;
4036 char **argv_expanded;
4039 /* it is not always needed, but we aim to smaller code */
4040 int squirrel[] = { -1, -1, -1 };
4043 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4046 IF_HUSH_JOB(pi->pgrp = -1;)
4047 pi->stopped_cmds = 0;
4048 command = &(pi->cmds[0]);
4049 argv_expanded = NULL;
4051 if (pi->num_cmds != 1
4052 || pi->followup == PIPE_BG
4053 || command->cmd_type == CMD_SUBSHELL
4060 debug_printf_exec(": group:%p argv:'%s'\n",
4061 command->group, command->argv ? command->argv[0] : "NONE");
4063 if (command->group) {
4064 #if ENABLE_HUSH_FUNCTIONS
4065 if (command->cmd_type == CMD_FUNCDEF) {
4066 /* "executing" func () { list } */
4067 struct function *funcp;
4069 funcp = new_function(command->argv[0]);
4070 /* funcp->name is already set to argv[0] */
4071 funcp->body = command->group;
4073 funcp->body_as_string = command->group_as_string;
4074 command->group_as_string = NULL;
4076 command->group = NULL;
4077 command->argv[0] = NULL;
4078 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4079 funcp->parent_cmd = command;
4080 command->child_func = funcp;
4082 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4084 return EXIT_SUCCESS;
4088 debug_printf("non-subshell group\n");
4089 rcode = 1; /* exitcode if redir failed */
4090 if (setup_redirects(command, squirrel) == 0) {
4091 debug_printf_exec(": run_list\n");
4092 rcode = run_list(command->group) & 0xff;
4094 restore_redirects(squirrel);
4095 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4097 debug_printf_exec("run_pipe: return %d\n", rcode);
4101 argv = command->argv ? command->argv : (char **) &null_ptr;
4103 const struct built_in_command *x;
4104 #if ENABLE_HUSH_FUNCTIONS
4105 const struct function *funcp;
4109 char **new_env = NULL;
4110 struct variable *old_vars = NULL;
4112 if (argv[command->assignment_cnt] == NULL) {
4113 /* Assignments, but no command */
4114 /* Ensure redirects take effect. Try "a=t >file" */
4115 rcode = setup_redirects(command, squirrel);
4116 //FIXME: "false; q=`false`; echo $?" should print 1
4117 restore_redirects(squirrel);
4118 /* Set shell variables */
4120 p = expand_string_to_string(*argv);
4121 debug_printf_exec("set shell var:'%s'->'%s'\n",
4123 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4126 /* Do we need to flag set_local_var() errors?
4127 * "assignment to readonly var" and "putenv error"
4129 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4131 debug_printf_exec("run_pipe: return %d\n", rcode);
4135 /* Expand the rest into (possibly) many strings each */
4137 #if ENABLE_HUSH_BASH_COMPAT
4138 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4139 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4142 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4143 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4144 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4149 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4152 /* if someone gives us an empty string: `cmd with empty output` */
4153 if (!argv_expanded[0]) {
4154 free(argv_expanded);
4156 return G.last_exitcode;
4159 x = find_builtin(argv_expanded[0]);
4160 #if ENABLE_HUSH_FUNCTIONS
4163 funcp = find_function(argv_expanded[0]);
4167 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4168 debug_printf("exec with redirects only\n");
4169 rcode = setup_redirects(command, NULL);
4170 goto clean_up_and_ret1;
4173 /* setup_redirects acts on file descriptors, not FILEs.
4174 * This is perfect for work that comes after exec().
4175 * Is it really safe for inline use? Experimentally,
4176 * things seem to work. */
4177 rcode = setup_redirects(command, squirrel);
4179 new_env = expand_assignments(argv, command->assignment_cnt);
4180 old_vars = set_vars_and_save_old(new_env);
4182 debug_printf_exec(": builtin '%s' '%s'...\n",
4183 x->cmd, argv_expanded[1]);
4184 rcode = x->b_function(argv_expanded) & 0xff;
4187 #if ENABLE_HUSH_FUNCTIONS
4189 # if ENABLE_HUSH_LOCAL
4190 struct variable **sv;
4191 sv = G.shadowed_vars_pp;
4192 G.shadowed_vars_pp = &old_vars;
4194 debug_printf_exec(": function '%s' '%s'...\n",
4195 funcp->name, argv_expanded[1]);
4196 rcode = run_function(funcp, argv_expanded) & 0xff;
4197 # if ENABLE_HUSH_LOCAL
4198 G.shadowed_vars_pp = sv;
4203 #if ENABLE_FEATURE_SH_STANDALONE
4206 restore_redirects(squirrel);
4207 unset_vars(new_env);
4210 free(argv_expanded);
4211 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4213 debug_printf_exec("run_pipe return %d\n", rcode);
4217 #if ENABLE_FEATURE_SH_STANDALONE
4218 i = find_applet_by_name(argv_expanded[0]);
4219 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4220 rcode = setup_redirects(command, squirrel);
4222 new_env = expand_assignments(argv, command->assignment_cnt);
4223 old_vars = set_vars_and_save_old(new_env);
4224 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4225 argv_expanded[0], argv_expanded[1]);
4226 rcode = run_nofork_applet(i, argv_expanded);
4228 goto clean_up_and_ret;
4231 /* It is neither builtin nor applet. We must fork. */
4235 /* NB: argv_expanded may already be created, and that
4236 * might include `cmd` runs! Do not rerun it! We *must*
4237 * use argv_expanded if it's non-NULL */
4239 /* Going to fork a child per each pipe member */
4243 for (i = 0; i < pi->num_cmds; i++) {
4244 struct fd_pair pipefds;
4246 volatile nommu_save_t nommu_save;
4247 nommu_save.new_env = NULL;
4248 nommu_save.old_vars = NULL;
4249 nommu_save.argv = NULL;
4250 nommu_save.argv_from_re_execing = NULL;
4252 command = &(pi->cmds[i]);
4253 if (command->argv) {
4254 debug_printf_exec(": pipe member '%s' '%s'...\n",
4255 command->argv[0], command->argv[1]);
4257 debug_printf_exec(": pipe member with no argv\n");
4260 /* pipes are inserted between pairs of commands */
4263 if ((i + 1) < pi->num_cmds)
4264 xpiped_pair(pipefds);
4266 command->pid = BB_MMU ? fork() : vfork();
4267 if (!command->pid) { /* child */
4269 disable_restore_tty_pgrp_on_exit();
4270 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4272 /* Every child adds itself to new process group
4273 * with pgid == pid_of_first_child_in_pipe */
4274 if (G.run_list_level == 1 && G_interactive_fd) {
4277 if (pgrp < 0) /* true for 1st process only */
4279 if (setpgid(0, pgrp) == 0
4280 && pi->followup != PIPE_BG
4281 && G_saved_tty_pgrp /* we have ctty */
4283 /* We do it in *every* child, not just first,
4285 tcsetpgrp(G_interactive_fd, pgrp);
4289 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4290 /* 1st cmd in backgrounded pipe
4291 * should have its stdin /dev/null'ed */
4293 if (open(bb_dev_null, O_RDONLY))
4294 xopen("/", O_RDONLY);
4296 xmove_fd(nextin, 0);
4298 xmove_fd(pipefds.wr, 1);
4301 /* Like bash, explicit redirects override pipes,
4302 * and the pipe fd is available for dup'ing. */
4303 if (setup_redirects(command, NULL))
4306 /* Restore default handlers just prior to exec */
4307 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4309 /* Stores to nommu_save list of env vars putenv'ed
4310 * (NOMMU, on MMU we don't need that) */
4311 /* cast away volatility... */
4312 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4313 /* pseudo_exec() does not return */
4316 /* parent or error */
4317 #if ENABLE_HUSH_FAST
4319 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4321 enable_restore_tty_pgrp_on_exit();
4323 /* Clean up after vforked child */
4324 free(nommu_save.argv);
4325 free(nommu_save.argv_from_re_execing);
4326 unset_vars(nommu_save.new_env);
4327 add_vars(nommu_save.old_vars);
4329 free(argv_expanded);
4330 argv_expanded = NULL;
4331 if (command->pid < 0) { /* [v]fork failed */
4332 /* Clearly indicate, was it fork or vfork */
4333 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4337 /* Second and next children need to know pid of first one */
4339 pi->pgrp = command->pid;
4345 if ((i + 1) < pi->num_cmds)
4347 /* Pass read (output) pipe end to next iteration */
4348 nextin = pipefds.rd;
4351 if (!pi->alive_cmds) {
4353 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4358 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4362 #ifndef debug_print_tree
4363 static void debug_print_tree(struct pipe *pi, int lvl)
4365 static const char *const PIPE[] = {
4371 static const char *RES[] = {
4372 [RES_NONE ] = "NONE" ,
4375 [RES_THEN ] = "THEN" ,
4376 [RES_ELIF ] = "ELIF" ,
4377 [RES_ELSE ] = "ELSE" ,
4380 # if ENABLE_HUSH_LOOPS
4381 [RES_FOR ] = "FOR" ,
4382 [RES_WHILE] = "WHILE",
4383 [RES_UNTIL] = "UNTIL",
4385 [RES_DONE ] = "DONE" ,
4387 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4390 # if ENABLE_HUSH_CASE
4391 [RES_CASE ] = "CASE" ,
4392 [RES_CASE_IN ] = "CASE_IN" ,
4393 [RES_MATCH] = "MATCH",
4394 [RES_CASE_BODY] = "CASE_BODY",
4395 [RES_ESAC ] = "ESAC" ,
4397 [RES_XXXX ] = "XXXX" ,
4398 [RES_SNTX ] = "SNTX" ,
4400 static const char *const CMDTYPE[] = {
4404 # if ENABLE_HUSH_FUNCTIONS
4413 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4414 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4416 while (prn < pi->num_cmds) {
4417 struct command *command = &pi->cmds[prn];
4418 char **argv = command->argv;
4420 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4422 command->assignment_cnt);
4423 if (command->group) {
4424 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4425 CMDTYPE[command->cmd_type],
4428 , " group_as_string:", command->group_as_string
4433 debug_print_tree(command->group, lvl+1);
4437 if (argv) while (*argv) {
4438 fprintf(stderr, " '%s'", *argv);
4441 fprintf(stderr, "\n");
4448 #endif /* debug_print_tree */
4450 /* NB: called by pseudo_exec, and therefore must not modify any
4451 * global data until exec/_exit (we can be a child after vfork!) */
4452 static int run_list(struct pipe *pi)
4454 #if ENABLE_HUSH_CASE
4455 char *case_word = NULL;
4457 #if ENABLE_HUSH_LOOPS
4458 struct pipe *loop_top = NULL;
4459 char **for_lcur = NULL;
4460 char **for_list = NULL;
4462 smallint last_followup;
4464 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4465 smalluint cond_code = 0;
4467 enum { cond_code = 0 };
4470 smallint rword; /* enum reserved_style */
4471 smallint last_rword; /* ditto */
4474 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4477 #if ENABLE_HUSH_LOOPS
4478 /* Check syntax for "for" */
4479 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4480 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4482 /* current word is FOR or IN (BOLD in comments below) */
4483 if (cpipe->next == NULL) {
4484 syntax_error("malformed for");
4486 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4489 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4490 if (cpipe->next->res_word == RES_DO)
4492 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4493 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4494 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4496 syntax_error("malformed for");
4498 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4504 /* Past this point, all code paths should jump to ret: label
4505 * in order to return, no direct "return" statements please.
4506 * This helps to ensure that no memory is leaked. */
4514 last_rword = RES_XXXX;
4516 last_followup = PIPE_SEQ;
4517 rcode = G.last_exitcode;
4519 /* Go through list of pipes, (maybe) executing them. */
4520 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4524 IF_HAS_KEYWORDS(rword = pi->res_word;)
4525 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4526 rword, cond_code, last_rword);
4527 #if ENABLE_HUSH_LOOPS
4528 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4529 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4531 /* start of a loop: remember where loop starts */
4536 /* Still in the same "if...", "then..." or "do..." branch? */
4537 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4538 if ((rcode == 0 && last_followup == PIPE_OR)
4539 || (rcode != 0 && last_followup == PIPE_AND)
4541 /* It is "<true> || CMD" or "<false> && CMD"
4542 * and we should not execute CMD */
4543 debug_printf_exec("skipped cmd because of || or &&\n");
4544 last_followup = pi->followup;
4548 last_followup = pi->followup;
4549 IF_HAS_KEYWORDS(last_rword = rword;)
4552 if (rword == RES_THEN) {
4553 /* if false; then ... fi has exitcode 0! */
4554 G.last_exitcode = rcode = EXIT_SUCCESS;
4555 /* "if <false> THEN cmd": skip cmd */
4559 if (rword == RES_ELSE || rword == RES_ELIF) {
4560 /* "if <true> then ... ELSE/ELIF cmd":
4561 * skip cmd and all following ones */
4566 #if ENABLE_HUSH_LOOPS
4567 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4569 /* first loop through for */
4571 static const char encoded_dollar_at[] ALIGN1 = {
4572 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4573 }; /* encoded representation of "$@" */
4574 static const char *const encoded_dollar_at_argv[] = {
4575 encoded_dollar_at, NULL
4576 }; /* argv list with one element: "$@" */
4579 vals = (char**)encoded_dollar_at_argv;
4580 if (pi->next->res_word == RES_IN) {
4581 /* if no variable values after "in" we skip "for" */
4582 if (!pi->next->cmds[0].argv) {
4583 G.last_exitcode = rcode = EXIT_SUCCESS;
4584 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4587 vals = pi->next->cmds[0].argv;
4588 } /* else: "for var; do..." -> assume "$@" list */
4589 /* create list of variable values */
4590 debug_print_strings("for_list made from", vals);
4591 for_list = expand_strvec_to_strvec(vals);
4592 for_lcur = for_list;
4593 debug_print_strings("for_list", for_list);
4596 /* "for" loop is over, clean up */
4602 /* Insert next value from for_lcur */
4603 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4604 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4607 if (rword == RES_IN) {
4608 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4610 if (rword == RES_DONE) {
4611 continue; /* "done" has no cmds too */
4614 #if ENABLE_HUSH_CASE
4615 if (rword == RES_CASE) {
4616 case_word = expand_strvec_to_string(pi->cmds->argv);
4619 if (rword == RES_MATCH) {
4622 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4624 /* all prev words didn't match, does this one match? */
4625 argv = pi->cmds->argv;
4627 char *pattern = expand_string_to_string(*argv);
4628 /* TODO: which FNM_xxx flags to use? */
4629 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4631 if (cond_code == 0) { /* match! we will execute this branch */
4632 free(case_word); /* make future "word)" stop */
4640 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4642 continue; /* not matched yet, skip this pipe */
4645 /* Just pressing <enter> in shell should check for jobs.
4646 * OTOH, in non-interactive shell this is useless
4647 * and only leads to extra job checks */
4648 if (pi->num_cmds == 0) {
4649 if (G_interactive_fd)
4650 goto check_jobs_and_continue;
4654 /* After analyzing all keywords and conditions, we decided
4655 * to execute this pipe. NB: have to do checkjobs(NULL)
4656 * after run_pipe to collect any background children,
4657 * even if list execution is to be stopped. */
4658 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4661 #if ENABLE_HUSH_LOOPS
4662 G.flag_break_continue = 0;
4664 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4666 /* We ran a builtin, function, or group.
4667 * rcode is already known
4668 * and we don't need to wait for anything. */
4669 G.last_exitcode = rcode;
4670 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4671 check_and_run_traps(0);
4672 #if ENABLE_HUSH_LOOPS
4673 /* Was it "break" or "continue"? */
4674 if (G.flag_break_continue) {
4675 smallint fbc = G.flag_break_continue;
4676 /* We might fall into outer *loop*,
4677 * don't want to break it too */
4679 G.depth_break_continue--;
4680 if (G.depth_break_continue == 0)
4681 G.flag_break_continue = 0;
4682 /* else: e.g. "continue 2" should *break* once, *then* continue */
4683 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4684 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4685 goto check_jobs_and_break;
4686 /* "continue": simulate end of loop */
4691 #if ENABLE_HUSH_FUNCTIONS
4692 if (G.flag_return_in_progress == 1) {
4693 /* same as "goto check_jobs_and_break" */
4698 } else if (pi->followup == PIPE_BG) {
4699 /* What does bash do with attempts to background builtins? */
4700 /* even bash 3.2 doesn't do that well with nested bg:
4701 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4702 * I'm NOT treating inner &'s as jobs */
4703 check_and_run_traps(0);
4705 if (G.run_list_level == 1)
4708 G.last_exitcode = rcode = EXIT_SUCCESS;
4709 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4712 if (G.run_list_level == 1 && G_interactive_fd) {
4713 /* Waits for completion, then fg's main shell */
4714 rcode = checkjobs_and_fg_shell(pi);
4715 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4716 check_and_run_traps(0);
4719 { /* This one just waits for completion */
4720 rcode = checkjobs(pi);
4721 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4722 check_and_run_traps(0);
4724 G.last_exitcode = rcode;
4728 /* Analyze how result affects subsequent commands */
4730 if (rword == RES_IF || rword == RES_ELIF)
4733 #if ENABLE_HUSH_LOOPS
4734 /* Beware of "while false; true; do ..."! */
4735 if (pi->next && pi->next->res_word == RES_DO) {
4736 if (rword == RES_WHILE) {
4738 /* "while false; do...done" - exitcode 0 */
4739 G.last_exitcode = rcode = EXIT_SUCCESS;
4740 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4741 goto check_jobs_and_break;
4744 if (rword == RES_UNTIL) {
4746 debug_printf_exec(": until expr is true: breaking\n");
4747 check_jobs_and_break:
4755 check_jobs_and_continue:
4762 #if ENABLE_HUSH_LOOPS
4767 #if ENABLE_HUSH_CASE
4771 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4775 /* Select which version we will use */
4776 static int run_and_free_list(struct pipe *pi)
4779 debug_printf_exec("run_and_free_list entered\n");
4781 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4782 rcode = run_list(pi);
4784 /* free_pipe_list has the side effect of clearing memory.
4785 * In the long run that function can be merged with run_list,
4786 * but doing that now would hobble the debugging effort. */
4788 debug_printf_exec("run_and_free_list return %d\n", rcode);
4793 static struct pipe *new_pipe(void)
4796 pi = xzalloc(sizeof(struct pipe));
4797 /*pi->followup = 0; - deliberately invalid value */
4798 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4802 /* Command (member of a pipe) is complete, or we start a new pipe
4803 * if ctx->command is NULL.
4804 * No errors possible here.
4806 static int done_command(struct parse_context *ctx)
4808 /* The command is really already in the pipe structure, so
4809 * advance the pipe counter and make a new, null command. */
4810 struct pipe *pi = ctx->pipe;
4811 struct command *command = ctx->command;
4814 if (IS_NULL_CMD(command)) {
4815 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4819 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4820 //debug_print_tree(ctx->list_head, 20);
4822 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4825 /* Only real trickiness here is that the uncommitted
4826 * command structure is not counted in pi->num_cmds. */
4827 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4828 ctx->command = command = &pi->cmds[pi->num_cmds];
4830 memset(command, 0, sizeof(*command));
4831 return pi->num_cmds; /* used only for 0/nonzero check */
4834 static void done_pipe(struct parse_context *ctx, pipe_style type)
4838 debug_printf_parse("done_pipe entered, followup %d\n", type);
4839 /* Close previous command */
4840 not_null = done_command(ctx);
4841 ctx->pipe->followup = type;
4843 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4844 ctx->ctx_inverted = 0;
4845 ctx->pipe->res_word = ctx->ctx_res_w;
4848 /* Without this check, even just <enter> on command line generates
4849 * tree of three NOPs (!). Which is harmless but annoying.
4850 * IOW: it is safe to do it unconditionally. */
4853 || ctx->ctx_res_w == RES_FI
4855 #if ENABLE_HUSH_LOOPS
4856 || ctx->ctx_res_w == RES_DONE
4857 || ctx->ctx_res_w == RES_FOR
4858 || ctx->ctx_res_w == RES_IN
4860 #if ENABLE_HUSH_CASE
4861 || ctx->ctx_res_w == RES_ESAC
4865 debug_printf_parse("done_pipe: adding new pipe: "
4866 "not_null:%d ctx->ctx_res_w:%d\n",
4867 not_null, ctx->ctx_res_w);
4869 ctx->pipe->next = new_p;
4871 /* RES_THEN, RES_DO etc are "sticky" -
4872 * they remain set for pipes inside if/while.
4873 * This is used to control execution.
4874 * RES_FOR and RES_IN are NOT sticky (needed to support
4875 * cases where variable or value happens to match a keyword):
4877 #if ENABLE_HUSH_LOOPS
4878 if (ctx->ctx_res_w == RES_FOR
4879 || ctx->ctx_res_w == RES_IN)
4880 ctx->ctx_res_w = RES_NONE;
4882 #if ENABLE_HUSH_CASE
4883 if (ctx->ctx_res_w == RES_MATCH)
4884 ctx->ctx_res_w = RES_CASE_BODY;
4885 if (ctx->ctx_res_w == RES_CASE)
4886 ctx->ctx_res_w = RES_CASE_IN;
4888 ctx->command = NULL; /* trick done_command below */
4889 /* Create the memory for command, roughly:
4890 * ctx->pipe->cmds = new struct command;
4891 * ctx->command = &ctx->pipe->cmds[0];
4894 //debug_print_tree(ctx->list_head, 10);
4896 debug_printf_parse("done_pipe return\n");
4899 static void initialize_context(struct parse_context *ctx)
4901 memset(ctx, 0, sizeof(*ctx));
4902 ctx->pipe = ctx->list_head = new_pipe();
4903 /* Create the memory for command, roughly:
4904 * ctx->pipe->cmds = new struct command;
4905 * ctx->command = &ctx->pipe->cmds[0];
4910 /* If a reserved word is found and processed, parse context is modified
4911 * and 1 is returned.
4914 struct reserved_combo {
4917 unsigned char assignment_flag;
4921 FLAG_END = (1 << RES_NONE ),
4923 FLAG_IF = (1 << RES_IF ),
4924 FLAG_THEN = (1 << RES_THEN ),
4925 FLAG_ELIF = (1 << RES_ELIF ),
4926 FLAG_ELSE = (1 << RES_ELSE ),
4927 FLAG_FI = (1 << RES_FI ),
4929 # if ENABLE_HUSH_LOOPS
4930 FLAG_FOR = (1 << RES_FOR ),
4931 FLAG_WHILE = (1 << RES_WHILE),
4932 FLAG_UNTIL = (1 << RES_UNTIL),
4933 FLAG_DO = (1 << RES_DO ),
4934 FLAG_DONE = (1 << RES_DONE ),
4935 FLAG_IN = (1 << RES_IN ),
4937 # if ENABLE_HUSH_CASE
4938 FLAG_MATCH = (1 << RES_MATCH),
4939 FLAG_ESAC = (1 << RES_ESAC ),
4941 FLAG_START = (1 << RES_XXXX ),
4944 static const struct reserved_combo* match_reserved_word(o_string *word)
4946 /* Mostly a list of accepted follow-up reserved words.
4947 * FLAG_END means we are done with the sequence, and are ready
4948 * to turn the compound list into a command.
4949 * FLAG_START means the word must start a new compound list.
4951 static const struct reserved_combo reserved_list[] = {
4953 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4954 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4955 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4956 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4957 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4958 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4960 # if ENABLE_HUSH_LOOPS
4961 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4962 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4963 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4964 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4965 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4966 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4968 # if ENABLE_HUSH_CASE
4969 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4970 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4973 const struct reserved_combo *r;
4975 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4976 if (strcmp(word->data, r->literal) == 0)
4981 /* Return 0: not a keyword, 1: keyword
4983 static int reserved_word(o_string *word, struct parse_context *ctx)
4985 # if ENABLE_HUSH_CASE
4986 static const struct reserved_combo reserved_match = {
4987 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4990 const struct reserved_combo *r;
4994 r = match_reserved_word(word);
4998 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4999 # if ENABLE_HUSH_CASE
5000 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5001 /* "case word IN ..." - IN part starts first MATCH part */
5002 r = &reserved_match;
5005 if (r->flag == 0) { /* '!' */
5006 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5007 syntax_error("! ! command");
5008 ctx->ctx_res_w = RES_SNTX;
5010 ctx->ctx_inverted = 1;
5013 if (r->flag & FLAG_START) {
5014 struct parse_context *old;
5016 old = xmalloc(sizeof(*old));
5017 debug_printf_parse("push stack %p\n", old);
5018 *old = *ctx; /* physical copy */
5019 initialize_context(ctx);
5021 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5022 syntax_error_at(word->data);
5023 ctx->ctx_res_w = RES_SNTX;
5026 /* "{...} fi" is ok. "{...} if" is not
5028 * if { echo foo; } then { echo bar; } fi */
5029 if (ctx->command->group)
5030 done_pipe(ctx, PIPE_SEQ);
5033 ctx->ctx_res_w = r->res;
5034 ctx->old_flag = r->flag;
5035 word->o_assignment = r->assignment_flag;
5037 if (ctx->old_flag & FLAG_END) {
5038 struct parse_context *old;
5040 done_pipe(ctx, PIPE_SEQ);
5041 debug_printf_parse("pop stack %p\n", ctx->stack);
5043 old->command->group = ctx->list_head;
5044 old->command->cmd_type = CMD_NORMAL;
5046 o_addstr(&old->as_string, ctx->as_string.data);
5047 o_free_unsafe(&ctx->as_string);
5048 old->command->group_as_string = xstrdup(old->as_string.data);
5049 debug_printf_parse("pop, remembering as:'%s'\n",
5050 old->command->group_as_string);
5052 *ctx = *old; /* physical copy */
5057 #endif /* HAS_KEYWORDS */
5059 /* Word is complete, look at it and update parsing context.
5060 * Normal return is 0. Syntax errors return 1.
5061 * Note: on return, word is reset, but not o_free'd!
5063 static int done_word(o_string *word, struct parse_context *ctx)
5065 struct command *command = ctx->command;
5067 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5068 if (word->length == 0 && word->o_quoted == 0) {
5069 debug_printf_parse("done_word return 0: true null, ignored\n");
5073 if (ctx->pending_redirect) {
5074 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5075 * only if run as "bash", not "sh" */
5076 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5078 * ...the word that follows the redirection operator
5079 * shall be subjected to tilde expansion, parameter expansion,
5080 * command substitution, arithmetic expansion, and quote
5081 * removal. Pathname expansion shall not be performed
5082 * on the word by a non-interactive shell; an interactive
5083 * shell may perform it, but shall do so only when
5084 * the expansion would result in one word."
5086 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5087 /* Cater for >\file case:
5088 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5089 * Same with heredocs:
5090 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5092 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5093 unbackslash(ctx->pending_redirect->rd_filename);
5094 /* Is it <<"HEREDOC"? */
5095 if (word->o_quoted) {
5096 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5099 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5100 ctx->pending_redirect = NULL;
5102 /* If this word wasn't an assignment, next ones definitely
5103 * can't be assignments. Even if they look like ones. */
5104 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5105 && word->o_assignment != WORD_IS_KEYWORD
5107 word->o_assignment = NOT_ASSIGNMENT;
5109 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5110 command->assignment_cnt++;
5111 word->o_assignment = MAYBE_ASSIGNMENT;
5115 # if ENABLE_HUSH_CASE
5116 if (ctx->ctx_dsemicolon
5117 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5119 /* already done when ctx_dsemicolon was set to 1: */
5120 /* ctx->ctx_res_w = RES_MATCH; */
5121 ctx->ctx_dsemicolon = 0;
5124 if (!command->argv /* if it's the first word... */
5125 # if ENABLE_HUSH_LOOPS
5126 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5127 && ctx->ctx_res_w != RES_IN
5129 # if ENABLE_HUSH_CASE
5130 && ctx->ctx_res_w != RES_CASE
5133 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5134 if (reserved_word(word, ctx)) {
5135 o_reset_to_empty_unquoted(word);
5136 debug_printf_parse("done_word return %d\n",
5137 (ctx->ctx_res_w == RES_SNTX));
5138 return (ctx->ctx_res_w == RES_SNTX);
5140 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5141 if (strcmp(word->data, "export") == 0
5142 # if ENABLE_HUSH_LOCAL
5143 || strcmp(word->data, "local") == 0
5146 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5149 # if ENABLE_HUSH_BASH_COMPAT
5150 if (strcmp(word->data, "[[") == 0) {
5151 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5157 if (command->group) {
5158 /* "{ echo foo; } echo bar" - bad */
5159 syntax_error_at(word->data);
5160 debug_printf_parse("done_word return 1: syntax error, "
5161 "groups and arglists don't mix\n");
5164 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5165 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5166 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5167 /* (otherwise it's known to be not empty and is already safe) */
5169 /* exclude "$@" - it can expand to no word despite "" */
5170 char *p = word->data;
5171 while (p[0] == SPECIAL_VAR_SYMBOL
5172 && (p[1] & 0x7f) == '@'
5173 && p[2] == SPECIAL_VAR_SYMBOL
5177 if (p == word->data || p[0] != '\0') {
5178 /* saw no "$@", or not only "$@" but some
5179 * real text is there too */
5180 /* insert "empty variable" reference, this makes
5181 * e.g. "", $empty"" etc to not disappear */
5182 o_addchr(word, SPECIAL_VAR_SYMBOL);
5183 o_addchr(word, SPECIAL_VAR_SYMBOL);
5186 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5187 debug_print_strings("word appended to argv", command->argv);
5190 #if ENABLE_HUSH_LOOPS
5191 if (ctx->ctx_res_w == RES_FOR) {
5193 || !is_well_formed_var_name(command->argv[0], '\0')
5195 /* bash says just "not a valid identifier" */
5196 syntax_error("not a valid identifier in for");
5199 /* Force FOR to have just one word (variable name) */
5200 /* NB: basically, this makes hush see "for v in ..."
5201 * syntax as if it is "for v; in ...". FOR and IN become
5202 * two pipe structs in parse tree. */
5203 done_pipe(ctx, PIPE_SEQ);
5206 #if ENABLE_HUSH_CASE
5207 /* Force CASE to have just one word */
5208 if (ctx->ctx_res_w == RES_CASE) {
5209 done_pipe(ctx, PIPE_SEQ);
5213 o_reset_to_empty_unquoted(word);
5215 debug_printf_parse("done_word return 0\n");
5220 /* Peek ahead in the input to find out if we have a "&n" construct,
5221 * as in "2>&1", that represents duplicating a file descriptor.
5223 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5224 * REDIRFD_SYNTAX_ERR if syntax error,
5225 * REDIRFD_TO_FILE if no & was seen,
5226 * or the number found.
5229 #define parse_redir_right_fd(as_string, input) \
5230 parse_redir_right_fd(input)
5232 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5238 return REDIRFD_TO_FILE;
5240 ch = i_getch(input); /* get the & */
5241 nommu_addchr(as_string, ch);
5244 ch = i_getch(input);
5245 nommu_addchr(as_string, ch);
5246 return REDIRFD_CLOSE;
5250 while (ch != EOF && isdigit(ch)) {
5251 d = d*10 + (ch-'0');
5253 ch = i_getch(input);
5254 nommu_addchr(as_string, ch);
5259 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5261 bb_error_msg("ambiguous redirect");
5262 return REDIRFD_SYNTAX_ERR;
5265 /* Return code is 0 normal, 1 if a syntax error is detected
5267 static int parse_redirect(struct parse_context *ctx,
5270 struct in_str *input)
5272 struct command *command = ctx->command;
5273 struct redir_struct *redir;
5274 struct redir_struct **redirp;
5277 dup_num = REDIRFD_TO_FILE;
5278 if (style != REDIRECT_HEREDOC) {
5279 /* Check for a '>&1' type redirect */
5280 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5281 if (dup_num == REDIRFD_SYNTAX_ERR)
5284 int ch = i_peek(input);
5285 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5286 if (dup_num) { /* <<-... */
5287 ch = i_getch(input);
5288 nommu_addchr(&ctx->as_string, ch);
5293 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5294 int ch = i_peek(input);
5296 /* >|FILE redirect ("clobbering" >).
5297 * Since we do not support "set -o noclobber" yet,
5298 * >| and > are the same for now. Just eat |.
5300 ch = i_getch(input);
5301 nommu_addchr(&ctx->as_string, ch);
5305 /* Create a new redir_struct and append it to the linked list */
5306 redirp = &command->redirects;
5307 while ((redir = *redirp) != NULL) {
5308 redirp = &(redir->next);
5310 *redirp = redir = xzalloc(sizeof(*redir));
5311 /* redir->next = NULL; */
5312 /* redir->rd_filename = NULL; */
5313 redir->rd_type = style;
5314 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5316 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5317 redir_table[style].descrip);
5319 redir->rd_dup = dup_num;
5320 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5321 /* Erik had a check here that the file descriptor in question
5322 * is legit; I postpone that to "run time"
5323 * A "-" representation of "close me" shows up as a -3 here */
5324 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5325 redir->rd_fd, redir->rd_dup);
5327 /* Set ctx->pending_redirect, so we know what to do at the
5328 * end of the next parsed word. */
5329 ctx->pending_redirect = redir;
5334 /* If a redirect is immediately preceded by a number, that number is
5335 * supposed to tell which file descriptor to redirect. This routine
5336 * looks for such preceding numbers. In an ideal world this routine
5337 * needs to handle all the following classes of redirects...
5338 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5339 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5340 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5341 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5343 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5345 * ... If n is quoted, the number shall not be recognized as part of
5346 * the redirection expression. For example:
5348 * writes the character 2 into file a"
5349 * We are getting it right by setting ->o_quoted on any \<char>
5351 * A -1 return means no valid number was found,
5352 * the caller should use the appropriate default for this redirection.
5354 static int redirect_opt_num(o_string *o)
5358 if (o->data == NULL)
5360 num = bb_strtou(o->data, NULL, 10);
5361 if (errno || num < 0)
5363 o_reset_to_empty_unquoted(o);
5368 #define fetch_till_str(as_string, input, word, skip_tabs) \
5369 fetch_till_str(input, word, skip_tabs)
5371 static char *fetch_till_str(o_string *as_string,
5372 struct in_str *input,
5376 o_string heredoc = NULL_O_STRING;
5382 ch = i_getch(input);
5383 nommu_addchr(as_string, ch);
5385 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5386 heredoc.data[past_EOL] = '\0';
5387 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5388 return heredoc.data;
5391 o_addchr(&heredoc, ch);
5392 past_EOL = heredoc.length;
5395 ch = i_getch(input);
5396 nommu_addchr(as_string, ch);
5397 } while (skip_tabs && ch == '\t');
5398 } while (ch == '\n');
5401 o_free_unsafe(&heredoc);
5404 o_addchr(&heredoc, ch);
5405 nommu_addchr(as_string, ch);
5409 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5410 * and load them all. There should be exactly heredoc_cnt of them.
5412 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5414 struct pipe *pi = ctx->list_head;
5416 while (pi && heredoc_cnt) {
5418 struct command *cmd = pi->cmds;
5420 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5422 cmd->argv ? cmd->argv[0] : "NONE");
5423 for (i = 0; i < pi->num_cmds; i++) {
5424 struct redir_struct *redir = cmd->redirects;
5426 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5427 i, cmd->argv ? cmd->argv[0] : "NONE");
5429 if (redir->rd_type == REDIRECT_HEREDOC) {
5432 redir->rd_type = REDIRECT_HEREDOC2;
5433 /* redir->rd_dup is (ab)used to indicate <<- */
5434 p = fetch_till_str(&ctx->as_string, input,
5435 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5437 syntax_error("unexpected EOF in here document");
5440 free(redir->rd_filename);
5441 redir->rd_filename = p;
5444 redir = redir->next;
5451 /* Should be 0. If it isn't, it's a parse error */
5453 bb_error_msg_and_die("heredoc BUG 2");
5459 #if ENABLE_HUSH_TICK
5460 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5465 char **to_free = NULL;
5469 pid = BB_MMU ? fork() : vfork();
5471 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5473 if (pid == 0) { /* child */
5474 disable_restore_tty_pgrp_on_exit();
5475 /* Process substitution is not considered to be usual
5476 * 'command execution'.
5477 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5484 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5485 close(channel[0]); /* NB: close _first_, then move fd! */
5486 xmove_fd(channel[1], 1);
5487 /* Prevent it from trying to handle ctrl-z etc */
5488 IF_HUSH_JOB(G.run_list_level = 1;)
5489 /* Awful hack for `trap` or $(trap).
5491 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5492 * contains an example where "trap" is executed in a subshell:
5494 * save_traps=$(trap)
5496 * eval "$save_traps"
5498 * Standard does not say that "trap" in subshell shall print
5499 * parent shell's traps. It only says that its output
5500 * must have suitable form, but then, in the above example
5501 * (which is not supposed to be normative), it implies that.
5503 * bash (and probably other shell) does implement it
5504 * (traps are reset to defaults, but "trap" still shows them),
5505 * but as a result, "trap" logic is hopelessly messed up:
5508 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5509 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5510 * # true | trap <--- trap is in subshell - no output (ditto)
5511 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5512 * trap -- 'echo Ho' SIGWINCH
5513 * # echo `(trap)` <--- in subshell in subshell - output
5514 * trap -- 'echo Ho' SIGWINCH
5515 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5516 * trap -- 'echo Ho' SIGWINCH
5518 * The rules when to forget and when to not forget traps
5519 * get really complex and nonsensical.
5521 * Our solution: ONLY bare $(trap) or `trap` is special.
5523 s = skip_whitespace(s);
5524 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5526 static const char *const argv[] = { NULL, NULL };
5527 builtin_trap((char**)argv);
5528 exit(0); /* not _exit() - we need to fflush */
5531 reset_traps_to_defaults();
5532 parse_and_run_string(s);
5533 _exit(G.last_exitcode);
5535 /* We re-execute after vfork on NOMMU. This makes this script safe:
5536 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5537 * huge=`cat BIG` # was blocking here forever
5540 re_execute_shell(&to_free,
5550 # if ENABLE_HUSH_FAST
5552 //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);
5554 enable_restore_tty_pgrp_on_exit();
5559 close_on_exec_on(channel[0]);
5560 return xfdopen_for_read(channel[0]);
5563 /* Return code is exit status of the process that is run. */
5564 static int process_command_subs(o_string *dest, const char *s)
5567 struct in_str pipe_str;
5569 int status, ch, eol_cnt;
5571 fp = generate_stream_from_string(s, &pid);
5573 /* Now send results of command back into original context */
5574 setup_file_in_str(&pipe_str, fp);
5576 while ((ch = i_getch(&pipe_str)) != EOF) {
5582 o_addchr(dest, '\n');
5585 o_addQchr(dest, ch);
5588 debug_printf("done reading from `cmd` pipe, closing it\n");
5590 /* We need to extract exitcode. Test case
5591 * "true; echo `sleep 1; false` $?"
5593 safe_waitpid(pid, &status, 0);
5594 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5595 return WEXITSTATUS(status);
5597 #endif /* ENABLE_HUSH_TICK */
5599 #if !ENABLE_HUSH_FUNCTIONS
5600 #define parse_group(dest, ctx, input, ch) \
5601 parse_group(ctx, input, ch)
5603 static int parse_group(o_string *dest, struct parse_context *ctx,
5604 struct in_str *input, int ch)
5606 /* dest contains characters seen prior to ( or {.
5607 * Typically it's empty, but for function defs,
5608 * it contains function name (without '()'). */
5609 struct pipe *pipe_list;
5611 struct command *command = ctx->command;
5613 debug_printf_parse("parse_group entered\n");
5614 #if ENABLE_HUSH_FUNCTIONS
5615 if (ch == '(' && !dest->o_quoted) {
5617 if (done_word(dest, ctx))
5620 goto skip; /* (... */
5621 if (command->argv[1]) { /* word word ... (... */
5622 syntax_error_unexpected_ch('(');
5625 /* it is "word(..." or "word (..." */
5627 ch = i_getch(input);
5628 while (ch == ' ' || ch == '\t');
5630 syntax_error_unexpected_ch(ch);
5633 nommu_addchr(&ctx->as_string, ch);
5635 ch = i_getch(input);
5636 while (ch == ' ' || ch == '\t' || ch == '\n');
5638 syntax_error_unexpected_ch(ch);
5641 nommu_addchr(&ctx->as_string, ch);
5642 command->cmd_type = CMD_FUNCDEF;
5647 #if 0 /* Prevented by caller */
5648 if (command->argv /* word [word]{... */
5649 || dest->length /* word{... */
5650 || dest->o_quoted /* ""{... */
5653 debug_printf_parse("parse_group return 1: "
5654 "syntax error, groups and arglists don't mix\n");
5659 #if ENABLE_HUSH_FUNCTIONS
5665 command->cmd_type = CMD_SUBSHELL;
5667 /* bash does not allow "{echo...", requires whitespace */
5668 ch = i_getch(input);
5669 if (ch != ' ' && ch != '\t' && ch != '\n') {
5670 syntax_error_unexpected_ch(ch);
5673 nommu_addchr(&ctx->as_string, ch);
5678 char *as_string = NULL;
5680 pipe_list = parse_stream(&as_string, input, endch);
5683 o_addstr(&ctx->as_string, as_string);
5685 /* empty ()/{} or parse error? */
5686 if (!pipe_list || pipe_list == ERR_PTR) {
5687 /* parse_stream already emitted error msg */
5691 debug_printf_parse("parse_group return 1: "
5692 "parse_stream returned %p\n", pipe_list);
5695 command->group = pipe_list;
5697 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5698 command->group_as_string = as_string;
5699 debug_printf_parse("end of group, remembering as:'%s'\n",
5700 command->group_as_string);
5703 debug_printf_parse("parse_group return 0\n");
5705 /* command remains "open", available for possible redirects */
5708 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5709 /* Subroutines for copying $(...) and `...` things */
5710 static void add_till_backquote(o_string *dest, struct in_str *input);
5712 static void add_till_single_quote(o_string *dest, struct in_str *input)
5715 int ch = i_getch(input);
5717 syntax_error_unterm_ch('\'');
5718 /*xfunc_die(); - redundant */
5725 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5726 static void add_till_double_quote(o_string *dest, struct in_str *input)
5729 int ch = i_getch(input);
5731 syntax_error_unterm_ch('"');
5732 /*xfunc_die(); - redundant */
5736 if (ch == '\\') { /* \x. Copy both chars. */
5738 ch = i_getch(input);
5742 add_till_backquote(dest, input);
5746 //if (ch == '$') ...
5749 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5751 * "Within the backquoted style of command substitution, backslash
5752 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5753 * The search for the matching backquote shall be satisfied by the first
5754 * backquote found without a preceding backslash; during this search,
5755 * if a non-escaped backquote is encountered within a shell comment,
5756 * a here-document, an embedded command substitution of the $(command)
5757 * form, or a quoted string, undefined results occur. A single-quoted
5758 * or double-quoted string that begins, but does not end, within the
5759 * "`...`" sequence produces undefined results."
5761 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5763 static void add_till_backquote(o_string *dest, struct in_str *input)
5766 int ch = i_getch(input);
5768 syntax_error_unterm_ch('`');
5769 /*xfunc_die(); - redundant */
5774 /* \x. Copy both chars unless it is \` */
5775 int ch2 = i_getch(input);
5777 syntax_error_unterm_ch('`');
5778 /*xfunc_die(); - redundant */
5780 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5787 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5788 * quoting and nested ()s.
5789 * "With the $(command) style of command substitution, all characters
5790 * following the open parenthesis to the matching closing parenthesis
5791 * constitute the command. Any valid shell script can be used for command,
5792 * except a script consisting solely of redirections which produces
5793 * unspecified results."
5795 * echo $(echo '(TEST)' BEST) (TEST) BEST
5796 * echo $(echo 'TEST)' BEST) TEST) BEST
5797 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5799 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5803 int ch = i_getch(input);
5805 syntax_error_unterm_ch(')');
5806 /*xfunc_die(); - redundant */
5814 if (i_peek(input) == ')') {
5822 add_till_single_quote(dest, input);
5827 add_till_double_quote(dest, input);
5832 /* \x. Copy verbatim. Important for \(, \) */
5833 ch = i_getch(input);
5835 syntax_error_unterm_ch(')');
5836 /*xfunc_die(); - redundant */
5843 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5845 /* Return code: 0 for OK, 1 for syntax error */
5847 #define handle_dollar(as_string, dest, input) \
5848 handle_dollar(dest, input)
5850 static int handle_dollar(o_string *as_string,
5852 struct in_str *input)
5854 int ch = i_peek(input); /* first character after the $ */
5855 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5857 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5859 ch = i_getch(input);
5860 nommu_addchr(as_string, ch);
5862 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5864 debug_printf_parse(": '%c'\n", ch);
5865 o_addchr(dest, ch | quote_mask);
5868 if (!isalnum(ch) && ch != '_')
5870 ch = i_getch(input);
5871 nommu_addchr(as_string, ch);
5873 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5874 } else if (isdigit(ch)) {
5876 ch = i_getch(input);
5877 nommu_addchr(as_string, ch);
5878 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5879 debug_printf_parse(": '%c'\n", ch);
5880 o_addchr(dest, ch | quote_mask);
5881 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5882 } else switch (ch) {
5884 case '!': /* last bg pid */
5885 case '?': /* last exit code */
5886 case '#': /* number of args */
5887 case '*': /* args */
5888 case '@': /* args */
5889 goto make_one_char_var;
5891 bool first_char, all_digits;
5894 ch = i_getch(input);
5895 nommu_addchr(as_string, ch);
5896 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5898 /* TODO: maybe someone will try to escape the '}' */
5903 ch = i_getch(input);
5904 nommu_addchr(as_string, ch);
5911 /* ${#var}: length of var contents */
5918 /* They're being verbose and doing ${?} */
5919 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5924 && ( (all_digits && !isdigit(ch))
5925 || (!all_digits && !isalnum(ch) && ch != '_')
5928 /* handle parameter expansions
5929 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5934 case ':': /* null modifier */
5935 if (expansion == 0) {
5936 debug_printf_parse(": null modifier\n");
5941 case '#': /* remove prefix */
5942 case '%': /* remove suffix */
5943 if (expansion == 0) {
5944 debug_printf_parse(": remove suffix/prefix\n");
5949 case '-': /* default value */
5950 case '=': /* assign default */
5951 case '+': /* alternative */
5952 case '?': /* error indicate */
5953 debug_printf_parse(": parameter expansion\n");
5958 syntax_error_unterm_str("${name}");
5959 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5964 debug_printf_parse(": '%c'\n", ch);
5965 o_addchr(dest, ch | quote_mask);
5969 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5972 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
5977 ch = i_getch(input);
5978 nommu_addchr(as_string, ch);
5979 # if ENABLE_SH_MATH_SUPPORT
5980 if (i_peek(input) == '(') {
5981 ch = i_getch(input);
5982 nommu_addchr(as_string, ch);
5983 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5984 o_addchr(dest, /*quote_mask |*/ '+');
5988 add_till_closing_paren(dest, input, true);
5991 o_addstr(as_string, dest->data + pos);
5992 o_addchr(as_string, ')');
5993 o_addchr(as_string, ')');
5996 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6000 # if ENABLE_HUSH_TICK
6001 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6002 o_addchr(dest, quote_mask | '`');
6006 add_till_closing_paren(dest, input, false);
6009 o_addstr(as_string, dest->data + pos);
6010 o_addchr(as_string, ')');
6013 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6019 ch = i_getch(input);
6020 nommu_addchr(as_string, ch);
6022 if (isalnum(ch)) { /* it's $_name or $_123 */
6027 /* TODO: $_ and $-: */
6028 /* $_ Shell or shell script name; or last argument of last command
6029 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6030 * but in command's env, set to full pathname used to invoke it */
6031 /* $- Option flags set by set builtin or shell options (-i etc) */
6033 o_addQchr(dest, '$');
6035 debug_printf_parse("handle_dollar return 0\n");
6040 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6041 parse_stream_dquoted(dest, input, dquote_end)
6043 static int parse_stream_dquoted(o_string *as_string,
6045 struct in_str *input,
6052 ch = i_getch(input);
6054 nommu_addchr(as_string, ch);
6055 if (ch == dquote_end) { /* may be only '"' or EOF */
6056 if (dest->o_assignment == NOT_ASSIGNMENT)
6057 dest->o_escape ^= 1;
6058 debug_printf_parse("parse_stream_dquoted return 0\n");
6061 /* note: can't move it above ch == dquote_end check! */
6063 syntax_error_unterm_ch('"');
6064 /*xfunc_die(); - redundant */
6068 next = i_peek(input);
6070 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6071 ch, ch, dest->o_escape);
6074 syntax_error("\\<eof>");
6078 * "The backslash retains its special meaning [in "..."]
6079 * only when followed by one of the following characters:
6080 * $, `, ", \, or <newline>. A double quote may be quoted
6081 * within double quotes by preceding it with a backslash."
6083 if (strchr("$`\"\\\n", next) != NULL) {
6084 ch = i_getch(input);
6086 o_addqchr(dest, ch);
6087 nommu_addchr(as_string, ch);
6090 o_addqchr(dest, '\\');
6091 nommu_addchr(as_string, '\\');
6096 if (handle_dollar(as_string, dest, input) != 0) {
6097 debug_printf_parse("parse_stream_dquoted return 1: "
6098 "handle_dollar returned non-0\n");
6103 #if ENABLE_HUSH_TICK
6105 //int pos = dest->length;
6106 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6107 o_addchr(dest, 0x80 | '`');
6108 add_till_backquote(dest, input);
6109 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6110 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6114 o_addQchr(dest, ch);
6116 && (dest->o_assignment == MAYBE_ASSIGNMENT
6117 || dest->o_assignment == WORD_IS_KEYWORD)
6118 && is_well_formed_var_name(dest->data, '=')
6120 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6126 * Scan input until EOF or end_trigger char.
6127 * Return a list of pipes to execute, or NULL on EOF
6128 * or if end_trigger character is met.
6129 * On syntax error, exit is shell is not interactive,
6130 * reset parsing machinery and start parsing anew,
6131 * or return ERR_PTR.
6133 static struct pipe *parse_stream(char **pstring,
6134 struct in_str *input,
6137 struct parse_context ctx;
6138 o_string dest = NULL_O_STRING;
6142 /* Double-quote state is handled in the state variable is_in_dquote.
6143 * A single-quote triggers a bypass of the main loop until its mate is
6144 * found. When recursing, quote state is passed in via dest->o_escape.
6146 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6147 end_trigger ? end_trigger : 'X');
6150 /* If very first arg is "" or '', dest.data may end up NULL.
6151 * Preventing this: */
6152 o_addchr(&dest, '\0');
6155 G.ifs = get_local_var_value("IFS");
6160 #if ENABLE_HUSH_INTERACTIVE
6161 input->promptmode = 0; /* PS1 */
6163 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6164 initialize_context(&ctx);
6169 const char *is_special;
6173 redir_type redir_style;
6176 /* dest.o_quoted = 1; - already is (see below) */
6177 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6180 /* We reached closing '"' */
6183 ch = i_getch(input);
6184 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6185 ch, ch, dest.o_escape);
6190 syntax_error_unterm_str("here document");
6193 /* end_trigger == '}' case errors out earlier,
6194 * checking only ')' */
6195 if (end_trigger == ')') {
6196 syntax_error_unterm_ch('('); /* exits */
6197 /* goto parse_error; */
6200 if (done_word(&dest, &ctx)) {
6204 done_pipe(&ctx, PIPE_SEQ);
6206 /* If we got nothing... */
6207 /* (this makes bare "&" cmd a no-op.
6208 * bash says: "syntax error near unexpected token '&'") */
6209 if (pi->num_cmds == 0
6210 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6216 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6218 *pstring = ctx.as_string.data;
6220 o_free_unsafe(&ctx.as_string);
6223 debug_printf_parse("parse_stream return %p\n", pi);
6226 nommu_addchr(&ctx.as_string, ch);
6230 next = i_peek(input);
6232 is_special = "{}<>;&|()#'" /* special outside of "str" */
6233 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6234 /* Are { and } special here? */
6235 if (ctx.command->argv /* word [word]{... */
6236 || dest.length /* word{... */
6237 || dest.o_quoted /* ""{... */
6238 || (next != ';' && next != ')' && !strchr(G.ifs, next)) /* {word */
6240 /* They are not special, skip "{}" */
6243 is_special = strchr(is_special, ch);
6244 is_ifs = strchr(G.ifs, ch);
6246 if (!is_special && !is_ifs) { /* ordinary char */
6248 o_addQchr(&dest, ch);
6249 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6250 || dest.o_assignment == WORD_IS_KEYWORD)
6252 && is_well_formed_var_name(dest.data, '=')
6254 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6260 if (done_word(&dest, &ctx)) {
6264 #if ENABLE_HUSH_CASE
6265 /* "case ... in <newline> word) ..." -
6266 * newlines are ignored (but ';' wouldn't be) */
6267 if (ctx.command->argv == NULL
6268 && ctx.ctx_res_w == RES_MATCH
6273 /* Treat newline as a command separator. */
6274 done_pipe(&ctx, PIPE_SEQ);
6275 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6277 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6282 dest.o_assignment = MAYBE_ASSIGNMENT;
6284 /* note: if (is_ifs) continue;
6285 * will still trigger for us */
6289 /* "cmd}" or "cmd }..." without semicolon or &:
6290 * } is an ordinary char in this case, even inside { cmd; }
6291 * Pathological example: { ""}; } should exec "}" cmd
6294 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6295 || dest.length != 0 /* word} */
6296 || dest.o_quoted /* ""} */
6300 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6301 goto skip_end_trigger;
6302 /* else: } does terminate a group */
6305 if (end_trigger && end_trigger == ch
6306 && (ch != ';' || heredoc_cnt == 0)
6307 #if ENABLE_HUSH_CASE
6309 || ctx.ctx_res_w != RES_MATCH
6310 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6315 /* This is technically valid:
6316 * { cat <<HERE; }; echo Ok
6320 * but we don't support this.
6321 * We require heredoc to be in enclosing {}/(),
6324 syntax_error_unterm_str("here document");
6327 if (done_word(&dest, &ctx)) {
6330 done_pipe(&ctx, PIPE_SEQ);
6331 dest.o_assignment = MAYBE_ASSIGNMENT;
6332 /* Do we sit outside of any if's, loops or case's? */
6334 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6338 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6340 *pstring = ctx.as_string.data;
6342 o_free_unsafe(&ctx.as_string);
6345 debug_printf_parse("parse_stream return %p: "
6346 "end_trigger char found\n",
6348 return ctx.list_head;
6355 /* Catch <, > before deciding whether this word is
6356 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6359 redir_fd = redirect_opt_num(&dest);
6360 if (done_word(&dest, &ctx)) {
6363 redir_style = REDIRECT_OVERWRITE;
6365 redir_style = REDIRECT_APPEND;
6366 ch = i_getch(input);
6367 nommu_addchr(&ctx.as_string, ch);
6370 else if (next == '(') {
6371 syntax_error(">(process) not supported");
6375 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6377 continue; /* back to top of while (1) */
6379 redir_fd = redirect_opt_num(&dest);
6380 if (done_word(&dest, &ctx)) {
6383 redir_style = REDIRECT_INPUT;
6385 redir_style = REDIRECT_HEREDOC;
6387 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6388 ch = i_getch(input);
6389 nommu_addchr(&ctx.as_string, ch);
6390 } else if (next == '>') {
6391 redir_style = REDIRECT_IO;
6392 ch = i_getch(input);
6393 nommu_addchr(&ctx.as_string, ch);
6396 else if (next == '(') {
6397 syntax_error("<(process) not supported");
6401 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6403 continue; /* back to top of while (1) */
6406 if (dest.o_assignment == MAYBE_ASSIGNMENT
6407 /* check that we are not in word in "a=1 2>word b=1": */
6408 && !ctx.pending_redirect
6410 /* ch is a special char and thus this word
6411 * cannot be an assignment */
6412 dest.o_assignment = NOT_ASSIGNMENT;
6415 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6419 if (dest.length == 0) {
6422 if (ch == EOF || ch == '\n')
6425 /* note: we do not add it to &ctx.as_string */
6427 nommu_addchr(&ctx.as_string, '\n');
6429 o_addQchr(&dest, ch);
6434 syntax_error("\\<eof>");
6437 ch = i_getch(input);
6439 o_addchr(&dest, '\\');
6440 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6441 o_addchr(&dest, ch);
6442 nommu_addchr(&ctx.as_string, ch);
6443 /* Example: echo Hello \2>file
6444 * we need to know that word 2 is quoted */
6449 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6450 ctx.as_string.data[--ctx.as_string.length] = '\0';
6455 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6456 debug_printf_parse("parse_stream parse error: "
6457 "handle_dollar returned non-0\n");
6464 ch = i_getch(input);
6466 syntax_error_unterm_ch('\'');
6467 /*xfunc_die(); - redundant */
6469 nommu_addchr(&ctx.as_string, ch);
6472 o_addqchr(&dest, ch);
6477 is_in_dquote ^= 1; /* invert */
6478 if (dest.o_assignment == NOT_ASSIGNMENT)
6481 #if ENABLE_HUSH_TICK
6486 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6487 o_addchr(&dest, '`');
6491 add_till_backquote(&dest, input);
6493 o_addstr(&ctx.as_string, dest.data + pos);
6494 o_addchr(&ctx.as_string, '`');
6496 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6497 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6502 #if ENABLE_HUSH_CASE
6505 if (done_word(&dest, &ctx)) {
6508 done_pipe(&ctx, PIPE_SEQ);
6509 #if ENABLE_HUSH_CASE
6510 /* Eat multiple semicolons, detect
6511 * whether it means something special */
6516 ch = i_getch(input);
6517 nommu_addchr(&ctx.as_string, ch);
6518 if (ctx.ctx_res_w == RES_CASE_BODY) {
6519 ctx.ctx_dsemicolon = 1;
6520 ctx.ctx_res_w = RES_MATCH;
6526 /* We just finished a cmd. New one may start
6527 * with an assignment */
6528 dest.o_assignment = MAYBE_ASSIGNMENT;
6531 if (done_word(&dest, &ctx)) {
6535 ch = i_getch(input);
6536 nommu_addchr(&ctx.as_string, ch);
6537 done_pipe(&ctx, PIPE_AND);
6539 done_pipe(&ctx, PIPE_BG);
6543 if (done_word(&dest, &ctx)) {
6546 #if ENABLE_HUSH_CASE
6547 if (ctx.ctx_res_w == RES_MATCH)
6548 break; /* we are in case's "word | word)" */
6550 if (next == '|') { /* || */
6551 ch = i_getch(input);
6552 nommu_addchr(&ctx.as_string, ch);
6553 done_pipe(&ctx, PIPE_OR);
6555 /* we could pick up a file descriptor choice here
6556 * with redirect_opt_num(), but bash doesn't do it.
6557 * "echo foo 2| cat" yields "foo 2". */
6560 o_reset_to_empty_unquoted(&ctx.as_string);
6565 #if ENABLE_HUSH_CASE
6566 /* "case... in [(]word)..." - skip '(' */
6567 if (ctx.ctx_res_w == RES_MATCH
6568 && ctx.command->argv == NULL /* not (word|(... */
6569 && dest.length == 0 /* not word(... */
6570 && dest.o_quoted == 0 /* not ""(... */
6576 if (parse_group(&dest, &ctx, input, ch) != 0) {
6581 #if ENABLE_HUSH_CASE
6582 if (ctx.ctx_res_w == RES_MATCH)
6586 /* proper use of this character is caught by end_trigger:
6587 * if we see {, we call parse_group(..., end_trigger='}')
6588 * and it will match } earlier (not here). */
6589 syntax_error_unexpected_ch(ch);
6593 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6599 struct parse_context *pctx;
6600 IF_HAS_KEYWORDS(struct parse_context *p2;)
6602 /* Clean up allocated tree.
6603 * Sample for finding leaks on syntax error recovery path.
6604 * Run it from interactive shell, watch pmap `pidof hush`.
6605 * while if false; then false; fi; do break; fi
6606 * Samples to catch leaks at execution:
6607 * while if (true | {true;}); then echo ok; fi; do break; done
6608 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6612 /* Update pipe/command counts,
6613 * otherwise freeing may miss some */
6614 done_pipe(pctx, PIPE_SEQ);
6615 debug_printf_clean("freeing list %p from ctx %p\n",
6616 pctx->list_head, pctx);
6617 debug_print_tree(pctx->list_head, 0);
6618 free_pipe_list(pctx->list_head);
6619 debug_printf_clean("freed list %p\n", pctx->list_head);
6621 o_free_unsafe(&pctx->as_string);
6623 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6627 IF_HAS_KEYWORDS(pctx = p2;)
6628 } while (HAS_KEYWORDS && pctx);
6629 /* Free text, clear all dest fields */
6631 /* If we are not in top-level parse, we return,
6632 * our caller will propagate error.
6634 if (end_trigger != ';') {
6642 /* Discard cached input, force prompt */
6644 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6649 /* Executing from string: eval, sh -c '...'
6650 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6651 * end_trigger controls how often we stop parsing
6652 * NUL: parse all, execute, return
6653 * ';': parse till ';' or newline, execute, repeat till EOF
6655 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6657 /* Why we need empty flag?
6658 * An obscure corner case "false; ``; echo $?":
6659 * empty command in `` should still set $? to 0.
6660 * But we can't just set $? to 0 at the start,
6661 * this breaks "false; echo `echo $?`" case.
6665 struct pipe *pipe_list;
6667 pipe_list = parse_stream(NULL, inp, end_trigger);
6668 if (!pipe_list) { /* EOF */
6670 G.last_exitcode = 0;
6673 debug_print_tree(pipe_list, 0);
6674 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6675 run_and_free_list(pipe_list);
6680 static void parse_and_run_string(const char *s)
6682 struct in_str input;
6683 setup_string_in_str(&input, s);
6684 parse_and_run_stream(&input, '\0');
6687 static void parse_and_run_file(FILE *f)
6689 struct in_str input;
6690 setup_file_in_str(&input, f);
6691 parse_and_run_stream(&input, ';');
6694 /* Called a few times only (or even once if "sh -c") */
6695 static void init_sigmasks(void)
6699 sigset_t old_blocked_set;
6701 if (!G.inherited_set_is_saved) {
6702 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6703 G.inherited_set = G.blocked_set;
6705 old_blocked_set = G.blocked_set;
6707 mask = (1 << SIGQUIT);
6708 if (G_interactive_fd) {
6709 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6710 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6711 mask |= SPECIAL_JOB_SIGS;
6713 G.non_DFL_mask = mask;
6718 sigaddset(&G.blocked_set, sig);
6722 sigdelset(&G.blocked_set, SIGCHLD);
6724 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6725 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6727 /* POSIX allows shell to re-enable SIGCHLD
6728 * even if it was SIG_IGN on entry */
6729 #if ENABLE_HUSH_FAST
6730 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6731 if (!G.inherited_set_is_saved)
6732 signal(SIGCHLD, SIGCHLD_handler);
6734 if (!G.inherited_set_is_saved)
6735 signal(SIGCHLD, SIG_DFL);
6738 G.inherited_set_is_saved = 1;
6743 static void maybe_set_to_sigexit(int sig)
6745 void (*handler)(int);
6746 /* non_DFL_mask'ed signals are, well, masked,
6747 * no need to set handler for them.
6749 if (!((G.non_DFL_mask >> sig) & 1)) {
6750 handler = signal(sig, sigexit);
6751 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6752 signal(sig, handler);
6755 /* Set handlers to restore tty pgrp and exit */
6756 static void set_fatal_handlers(void)
6758 /* We _must_ restore tty pgrp on fatal signals */
6760 maybe_set_to_sigexit(SIGILL );
6761 maybe_set_to_sigexit(SIGFPE );
6762 maybe_set_to_sigexit(SIGBUS );
6763 maybe_set_to_sigexit(SIGSEGV);
6764 maybe_set_to_sigexit(SIGTRAP);
6765 } /* else: hush is perfect. what SEGV? */
6766 maybe_set_to_sigexit(SIGABRT);
6767 /* bash 3.2 seems to handle these just like 'fatal' ones */
6768 maybe_set_to_sigexit(SIGPIPE);
6769 maybe_set_to_sigexit(SIGALRM);
6770 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6771 * if we aren't interactive... but in this case
6772 * we never want to restore pgrp on exit, and this fn is not called */
6773 /*maybe_set_to_sigexit(SIGHUP );*/
6774 /*maybe_set_to_sigexit(SIGTERM);*/
6775 /*maybe_set_to_sigexit(SIGINT );*/
6779 static int set_mode(const char cstate, const char mode)
6781 int state = (cstate == '-' ? 1 : 0);
6783 case 'n': G.fake_mode = state; break;
6784 case 'x': /*G.debug_mode = state;*/ break;
6785 default: return EXIT_FAILURE;
6787 return EXIT_SUCCESS;
6790 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6791 int hush_main(int argc, char **argv)
6793 static const struct variable const_shell_ver = {
6795 .varstr = (char*)hush_version_str,
6796 .max_len = 1, /* 0 can provoke free(name) */
6801 unsigned builtin_argc;
6803 struct variable *cur_var;
6806 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6807 G.last_exitcode = EXIT_SUCCESS;
6809 G.argv0_for_re_execing = argv[0];
6811 /* Deal with HUSH_VERSION */
6812 G.shell_ver = const_shell_ver; /* copying struct here */
6813 G.top_var = &G.shell_ver;
6814 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6815 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6816 /* Initialize our shell local variables with the values
6817 * currently living in the environment */
6818 cur_var = G.top_var;
6821 char *value = strchr(*e, '=');
6822 if (value) { /* paranoia */
6823 cur_var->next = xzalloc(sizeof(*cur_var));
6824 cur_var = cur_var->next;
6825 cur_var->varstr = *e;
6826 cur_var->max_len = strlen(*e);
6827 cur_var->flg_export = 1;
6831 /* reinstate HUSH_VERSION */
6832 debug_printf_env("putenv '%s'\n", hush_version_str);
6833 putenv((char *)hush_version_str);
6836 set_pwd_var(/*exp:*/ 1);
6837 /* bash also exports SHLVL and _,
6838 * and sets (but doesn't export) the following variables:
6840 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6841 * BASH_VERSION='3.2.0(1)-release'
6843 * MACHTYPE=i386-pc-linux-gnu
6845 * HOSTNAME=<xxxxxxxxxx>
6846 * PPID=<NNNNN> - we also do it elsewhere
6857 * PIPESTATUS=([0]="0")
6858 * HISTFILE=/<xxx>/.bash_history
6862 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6864 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6874 #if ENABLE_FEATURE_EDITING
6875 G.line_input_state = new_line_input_t(FOR_SHELL);
6877 G.global_argc = argc;
6878 G.global_argv = argv;
6879 /* Initialize some more globals to non-zero values */
6880 cmdedit_update_prompt();
6882 if (setjmp(die_jmp)) {
6883 /* xfunc has failed! die die die */
6884 /* no EXIT traps, this is an escape hatch! */
6886 hush_exit(xfunc_error_retval);
6889 /* Shell is non-interactive at first. We need to call
6890 * init_sigmasks() if we are going to execute "sh <script>",
6891 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6892 * If we later decide that we are interactive, we run init_sigmasks()
6893 * in order to intercept (more) signals.
6897 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6900 opt = getopt(argc, argv, "+c:xins"
6903 # if ENABLE_HUSH_FUNCTIONS
6913 * sh ... -c 'script'
6914 * sh ... -c 'script' ARG0 [ARG1...]
6915 * On NOMMU, if builtin_argc != 0,
6916 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
6917 * "" needs to be replaced with NULL
6918 * and BARGV vector fed to builtin function.
6919 * Note: the form without ARG0 never happens:
6920 * sh ... -c 'builtin' BARGV... ""
6923 G.root_pid = getpid();
6924 G.root_ppid = getppid();
6926 G.global_argv = argv + optind;
6927 G.global_argc = argc - optind;
6929 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6930 const struct built_in_command *x;
6933 x = find_builtin(optarg);
6934 if (x) { /* paranoia */
6935 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6936 G.global_argv += builtin_argc;
6937 G.global_argv[-1] = NULL; /* replace "" */
6938 G.last_exitcode = x->b_function(argv + optind - 1);
6942 if (!G.global_argv[0]) {
6943 /* -c 'script' (no params): prevent empty $0 */
6944 G.global_argv--; /* points to argv[i] of 'script' */
6945 G.global_argv[0] = argv[0];
6947 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
6949 parse_and_run_string(optarg);
6952 /* Well, we cannot just declare interactiveness,
6953 * we have to have some stuff (ctty, etc) */
6954 /* G_interactive_fd++; */
6957 /* "-s" means "read from stdin", but this is how we always
6958 * operate, so simply do nothing here. */
6961 case '<': /* "big heredoc" support */
6962 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6965 unsigned long long empty_trap_mask;
6967 G.root_pid = bb_strtou(optarg, &optarg, 16);
6969 G.root_ppid = bb_strtou(optarg, &optarg, 16);
6971 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6973 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6975 builtin_argc = bb_strtou(optarg, &optarg, 16);
6977 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
6978 if (empty_trap_mask != 0) {
6981 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6982 for (sig = 1; sig < NSIG; sig++) {
6983 if (empty_trap_mask & (1LL << sig)) {
6984 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
6985 sigaddset(&G.blocked_set, sig);
6988 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6990 # if ENABLE_HUSH_LOOPS
6992 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6998 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7000 # if ENABLE_HUSH_FUNCTIONS
7002 struct function *funcp = new_function(optarg);
7003 /* funcp->name is already set to optarg */
7004 /* funcp->body is set to NULL. It's a special case. */
7005 funcp->body_as_string = argv[optind];
7013 if (!set_mode('-', opt))
7017 fprintf(stderr, "Usage: sh [FILE]...\n"
7018 " or: sh -c command [args]...\n\n");
7024 } /* option parsing loop */
7027 G.root_pid = getpid();
7028 G.root_ppid = getppid();
7031 /* If we are login shell... */
7032 if (argv[0] && argv[0][0] == '-') {
7034 debug_printf("sourcing /etc/profile\n");
7035 input = fopen_for_read("/etc/profile");
7036 if (input != NULL) {
7037 close_on_exec_on(fileno(input));
7039 parse_and_run_file(input);
7042 /* bash: after sourcing /etc/profile,
7043 * tries to source (in the given order):
7044 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7045 * stopping on first found. --noprofile turns this off.
7046 * bash also sources ~/.bash_logout on exit.
7047 * If called as sh, skips .bash_XXX files.
7054 * "bash <script>" (which is never interactive (unless -i?))
7055 * sources $BASH_ENV here (without scanning $PATH).
7056 * If called as sh, does the same but with $ENV.
7058 debug_printf("running script '%s'\n", argv[optind]);
7059 G.global_argv = argv + optind;
7060 G.global_argc = argc - optind;
7061 input = xfopen_for_read(argv[optind]);
7062 close_on_exec_on(fileno(input));
7064 parse_and_run_file(input);
7065 #if ENABLE_FEATURE_CLEAN_UP
7071 /* Up to here, shell was non-interactive. Now it may become one.
7072 * NB: don't forget to (re)run init_sigmasks() as needed.
7075 /* A shell is interactive if the '-i' flag was given,
7076 * or if all of the following conditions are met:
7078 * no arguments remaining or the -s flag given
7079 * standard input is a terminal
7080 * standard output is a terminal
7081 * Refer to Posix.2, the description of the 'sh' utility.
7084 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7085 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7086 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7087 if (G_saved_tty_pgrp < 0)
7088 G_saved_tty_pgrp = 0;
7090 /* try to dup stdin to high fd#, >= 255 */
7091 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7092 if (G_interactive_fd < 0) {
7093 /* try to dup to any fd */
7094 G_interactive_fd = dup(STDIN_FILENO);
7095 if (G_interactive_fd < 0) {
7097 G_interactive_fd = 0;
7098 G_saved_tty_pgrp = 0;
7101 // TODO: track & disallow any attempts of user
7102 // to (inadvertently) close/redirect G_interactive_fd
7104 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7105 if (G_interactive_fd) {
7106 close_on_exec_on(G_interactive_fd);
7108 if (G_saved_tty_pgrp) {
7109 /* If we were run as 'hush &', sleep until we are
7110 * in the foreground (tty pgrp == our pgrp).
7111 * If we get started under a job aware app (like bash),
7112 * make sure we are now in charge so we don't fight over
7113 * who gets the foreground */
7115 pid_t shell_pgrp = getpgrp();
7116 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7117 if (G_saved_tty_pgrp == shell_pgrp)
7119 /* send TTIN to ourself (should stop us) */
7120 kill(- shell_pgrp, SIGTTIN);
7124 /* Block some signals */
7127 if (G_saved_tty_pgrp) {
7128 /* Set other signals to restore saved_tty_pgrp */
7129 set_fatal_handlers();
7130 /* Put ourselves in our own process group
7131 * (bash, too, does this only if ctty is available) */
7132 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7133 /* Grab control of the terminal */
7134 tcsetpgrp(G_interactive_fd, getpid());
7136 /* -1 is special - makes xfuncs longjmp, not exit
7137 * (we reset die_sleep = 0 whereever we [v]fork) */
7138 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7142 #elif ENABLE_HUSH_INTERACTIVE
7143 /* No job control compiled in, only prompt/line editing */
7144 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7145 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7146 if (G_interactive_fd < 0) {
7147 /* try to dup to any fd */
7148 G_interactive_fd = dup(STDIN_FILENO);
7149 if (G_interactive_fd < 0)
7151 G_interactive_fd = 0;
7154 if (G_interactive_fd) {
7155 close_on_exec_on(G_interactive_fd);
7159 /* We have interactiveness code disabled */
7163 * if interactive but not a login shell, sources ~/.bashrc
7164 * (--norc turns this off, --rcfile <file> overrides)
7167 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7168 /* note: ash and hush share this string */
7169 printf("\n\n%s %s\n"
7170 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7173 "hush - the humble shell"
7177 parse_and_run_file(stdin);
7180 #if ENABLE_FEATURE_CLEAN_UP
7181 if (G.cwd != bb_msg_unknown)
7183 cur_var = G.top_var->next;
7185 struct variable *tmp = cur_var;
7186 if (!cur_var->max_len)
7187 free(cur_var->varstr);
7188 cur_var = cur_var->next;
7192 hush_exit(G.last_exitcode);
7197 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7198 int lash_main(int argc, char **argv)
7200 bb_error_msg("lash is deprecated, please use hush instead");
7201 return hush_main(argc, argv);
7206 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7207 int msh_main(int argc, char **argv)
7209 //bb_error_msg("msh is deprecated, please use hush instead");
7210 return hush_main(argc, argv);
7218 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7223 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7230 return applet_main_func(argc, argv - argc);
7233 static int FAST_FUNC builtin_test(char **argv)
7235 return run_applet_main(argv, test_main);
7238 static int FAST_FUNC builtin_echo(char **argv)
7240 return run_applet_main(argv, echo_main);
7244 static int FAST_FUNC builtin_printf(char **argv)
7246 return run_applet_main(argv, printf_main);
7250 static int FAST_FUNC builtin_eval(char **argv)
7252 int rcode = EXIT_SUCCESS;
7255 char *str = expand_strvec_to_string(argv);
7257 * eval "echo Hi; done" ("done" is syntax error):
7258 * "echo Hi" will not execute too.
7260 parse_and_run_string(str);
7262 rcode = G.last_exitcode;
7267 static int FAST_FUNC builtin_cd(char **argv)
7269 const char *newdir = argv[1];
7270 if (newdir == NULL) {
7271 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7272 * bash says "bash: cd: HOME not set" and does nothing
7275 const char *home = get_local_var_value("HOME");
7276 newdir = home ? home : "/";
7278 if (chdir(newdir)) {
7279 /* Mimic bash message exactly */
7280 bb_perror_msg("cd: %s", newdir);
7281 return EXIT_FAILURE;
7283 /* Read current dir (get_cwd(1) is inside) and set PWD.
7284 * Note: do not enforce exporting. If PWD was unset or unexported,
7285 * set it again, but do not export. bash does the same.
7287 set_pwd_var(/*exp:*/ 0);
7288 return EXIT_SUCCESS;
7291 static int FAST_FUNC builtin_exec(char **argv)
7293 if (*++argv == NULL)
7294 return EXIT_SUCCESS; /* bash does this */
7296 /* Careful: we can end up here after [v]fork. Do not restore
7297 * tty pgrp then, only top-level shell process does that */
7298 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7299 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7301 /* TODO: if exec fails, bash does NOT exit! We do.
7302 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7303 * and tcsetpgrp, and this is inherently racy.
7305 execvp_or_die(argv);
7308 static int FAST_FUNC builtin_exit(char **argv)
7310 debug_printf_exec("%s()\n", __func__);
7312 /* interactive bash:
7313 * # trap "echo EEE" EXIT
7316 * There are stopped jobs.
7317 * (if there are _stopped_ jobs, running ones don't count)
7320 # EEE (then bash exits)
7322 * we can use G.exiting = -1 as indicator "last cmd was exit"
7325 /* note: EXIT trap is run by hush_exit */
7326 if (*++argv == NULL)
7327 hush_exit(G.last_exitcode);
7328 /* mimic bash: exit 123abc == exit 255 + error msg */
7329 xfunc_error_retval = 255;
7330 /* bash: exit -2 == exit 254, no error msg */
7331 hush_exit(xatoi(*argv) & 0xff);
7334 static void print_escaped(const char *s)
7339 const char *p = strchrnul(s, '\'');
7340 /* print 'xxxx', possibly just '' */
7341 printf("'%.*s'", (int)(p - s), s);
7346 /* s points to '; print "'''...'''" */
7348 do putchar('\''); while (*++s == '\'');
7353 #if !ENABLE_HUSH_LOCAL
7354 #define helper_export_local(argv, exp, lvl) \
7355 helper_export_local(argv, exp)
7357 static void helper_export_local(char **argv, int exp, int lvl)
7362 /* So far we do not check that name is valid (TODO?) */
7364 if (strchr(name, '=') == NULL) {
7365 struct variable *var;
7367 var = get_local_var(name);
7368 if (exp == -1) { /* unexporting? */
7369 /* export -n NAME (without =VALUE) */
7371 var->flg_export = 0;
7372 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7374 } /* else: export -n NOT_EXISTING_VAR: no-op */
7377 if (exp == 1) { /* exporting? */
7378 /* export NAME (without =VALUE) */
7380 var->flg_export = 1;
7381 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7382 putenv(var->varstr);
7386 /* Exporting non-existing variable.
7387 * bash does not put it in environment,
7388 * but remembers that it is exported,
7389 * and does put it in env when it is set later.
7390 * We just set it to "" and export. */
7391 /* Or, it's "local NAME" (without =VALUE).
7392 * bash sets the value to "". */
7393 name = xasprintf("%s=", name);
7395 /* (Un)exporting/making local NAME=VALUE */
7396 name = xstrdup(name);
7398 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7402 static int FAST_FUNC builtin_export(char **argv)
7404 unsigned opt_unexport;
7406 #if ENABLE_HUSH_EXPORT_N
7407 /* "!": do not abort on errors */
7408 opt_unexport = getopt32(argv, "!n");
7409 if (opt_unexport == (uint32_t)-1)
7410 return EXIT_FAILURE;
7417 if (argv[0] == NULL) {
7424 /* ash emits: export VAR='VAL'
7425 * bash: declare -x VAR="VAL"
7426 * we follow ash example */
7427 const char *s = *e++;
7428 const char *p = strchr(s, '=');
7430 if (!p) /* wtf? take next variable */
7433 printf("export %.*s", (int)(p - s) + 1, s);
7434 print_escaped(p + 1);
7438 /*fflush_all(); - done after each builtin anyway */
7440 return EXIT_SUCCESS;
7443 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7445 return EXIT_SUCCESS;
7448 #if ENABLE_HUSH_LOCAL
7449 static int FAST_FUNC builtin_local(char **argv)
7451 if (G.func_nest_level == 0) {
7452 bb_error_msg("%s: not in a function", argv[0]);
7453 return EXIT_FAILURE; /* bash compat */
7455 helper_export_local(argv, 0, G.func_nest_level);
7456 return EXIT_SUCCESS;
7460 static int FAST_FUNC builtin_trap(char **argv)
7466 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7471 /* No args: print all trapped */
7472 for (i = 0; i < NSIG; ++i) {
7475 print_escaped(G.traps[i]);
7476 /* note: bash adds "SIG", but only if invoked
7477 * as "bash". If called as "sh", or if set -o posix,
7478 * then it prints short signal names.
7479 * We are printing short names: */
7480 printf(" %s\n", get_signame(i));
7483 /*fflush_all(); - done after each builtin anyway */
7484 return EXIT_SUCCESS;
7488 /* If first arg is a number: reset all specified signals */
7489 sig = bb_strtou(*argv, NULL, 10);
7495 sig = get_signum(*argv++);
7496 if (sig < 0 || sig >= NSIG) {
7498 /* Mimic bash message exactly */
7499 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7504 G.traps[sig] = xstrdup(new_cmd);
7506 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7507 get_signame(sig), sig, G.traps[sig]);
7509 /* There is no signal for 0 (EXIT) */
7514 sigaddset(&G.blocked_set, sig);
7516 /* There was a trap handler, we are removing it
7517 * (if sig has non-DFL handling,
7518 * we don't need to do anything) */
7519 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7521 sigdelset(&G.blocked_set, sig);
7524 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7528 if (!argv[1]) { /* no second arg */
7529 bb_error_msg("trap: invalid arguments");
7530 return EXIT_FAILURE;
7533 /* First arg is "-": reset all specified to default */
7534 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7535 /* Everything else: set arg as signal handler
7536 * (includes "" case, which ignores signal) */
7537 if (argv[0][0] == '-') {
7538 if (argv[0][1] == '\0') { /* "-" */
7539 /* new_cmd remains NULL: "reset these sigs" */
7542 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7545 /* else: "-something", no special meaning */
7550 goto process_sig_list;
7553 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7554 static int FAST_FUNC builtin_type(char **argv)
7556 int ret = EXIT_SUCCESS;
7562 if (0) {} /* make conditional compile easier below */
7563 /*else if (find_alias(*argv))
7564 type = "an alias";*/
7565 #if ENABLE_HUSH_FUNCTIONS
7566 else if (find_function(*argv))
7567 type = "a function";
7569 else if (find_builtin(*argv))
7570 type = "a shell builtin";
7571 else if ((path = find_in_path(*argv)) != NULL)
7574 bb_error_msg("type: %s: not found", *argv);
7579 printf("%s is %s\n", *argv, type);
7587 /* built-in 'fg' and 'bg' handler */
7588 static int FAST_FUNC builtin_fg_bg(char **argv)
7593 if (!G_interactive_fd)
7594 return EXIT_FAILURE;
7596 /* If they gave us no args, assume they want the last backgrounded task */
7598 for (pi = G.job_list; pi; pi = pi->next) {
7599 if (pi->jobid == G.last_jobid) {
7603 bb_error_msg("%s: no current job", argv[0]);
7604 return EXIT_FAILURE;
7606 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7607 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7608 return EXIT_FAILURE;
7610 for (pi = G.job_list; pi; pi = pi->next) {
7611 if (pi->jobid == jobnum) {
7615 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7616 return EXIT_FAILURE;
7618 /* TODO: bash prints a string representation
7619 * of job being foregrounded (like "sleep 1 | cat") */
7620 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7621 /* Put the job into the foreground. */
7622 tcsetpgrp(G_interactive_fd, pi->pgrp);
7625 /* Restart the processes in the job */
7626 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7627 for (i = 0; i < pi->num_cmds; i++) {
7628 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7629 pi->cmds[i].is_stopped = 0;
7631 pi->stopped_cmds = 0;
7633 i = kill(- pi->pgrp, SIGCONT);
7635 if (errno == ESRCH) {
7636 delete_finished_bg_job(pi);
7637 return EXIT_SUCCESS;
7639 bb_perror_msg("kill (SIGCONT)");
7642 if (argv[0][0] == 'f') {
7644 return checkjobs_and_fg_shell(pi);
7646 return EXIT_SUCCESS;
7650 #if ENABLE_HUSH_HELP
7651 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7653 const struct built_in_command *x;
7656 "Built-in commands:\n"
7657 "------------------\n");
7658 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7660 printf("%s\t%s\n", x->b_cmd, x->b_descr);
7663 return EXIT_SUCCESS;
7668 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7671 const char *status_string;
7673 for (job = G.job_list; job; job = job->next) {
7674 if (job->alive_cmds == job->stopped_cmds)
7675 status_string = "Stopped";
7677 status_string = "Running";
7679 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7681 return EXIT_SUCCESS;
7686 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7691 # ifdef M_TRIM_THRESHOLD
7692 /* Optional. Reduces probability of false positives */
7695 /* Crude attempt to find where "free memory" starts,
7696 * sans fragmentation. */
7698 l = (unsigned long)p;
7701 if (l < (unsigned long)p) l = (unsigned long)p;
7704 if (!G.memleak_value)
7705 G.memleak_value = l;
7707 l -= G.memleak_value;
7714 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7719 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7722 return EXIT_SUCCESS;
7725 static int FAST_FUNC builtin_read(char **argv)
7734 /* "!": do not abort on errors.
7735 * Option string must start with "sr" to match BUILTIN_READ_xxx
7737 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7738 if (read_flags == (uint32_t)-1)
7739 return EXIT_FAILURE;
7742 r = shell_builtin_read(set_local_var_from_halves,
7744 get_local_var_value("IFS"), /* can be NULL */
7752 if ((uintptr_t)r > 1) {
7753 bb_error_msg("%s", r);
7754 r = (char*)(uintptr_t)1;
7757 return (uintptr_t)r;
7760 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7761 * built-in 'set' handler
7763 * set [-abCefhmnuvx] [-o option] [argument...]
7764 * set [+abCefhmnuvx] [+o option] [argument...]
7765 * set -- [argument...]
7768 * Implementations shall support the options in both their hyphen and
7769 * plus-sign forms. These options can also be specified as options to sh.
7771 * Write out all variables and their values: set
7772 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7773 * Turn on the -x and -v options: set -xv
7774 * Unset all positional parameters: set --
7775 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7776 * Set the positional parameters to the expansion of x, even if x expands
7777 * with a leading '-' or '+': set -- $x
7779 * So far, we only support "set -- [argument...]" and some of the short names.
7781 static int FAST_FUNC builtin_set(char **argv)
7784 char **pp, **g_argv;
7785 char *arg = *++argv;
7789 for (e = G.top_var; e; e = e->next)
7791 return EXIT_SUCCESS;
7795 if (!strcmp(arg, "--")) {
7799 if (arg[0] != '+' && arg[0] != '-')
7801 for (n = 1; arg[n]; ++n)
7802 if (set_mode(arg[0], arg[n]))
7804 } while ((arg = *++argv) != NULL);
7805 /* Now argv[0] is 1st argument */
7808 return EXIT_SUCCESS;
7811 /* NB: G.global_argv[0] ($0) is never freed/changed */
7812 g_argv = G.global_argv;
7813 if (G.global_args_malloced) {
7819 G.global_args_malloced = 1;
7820 pp = xzalloc(sizeof(pp[0]) * 2);
7821 pp[0] = g_argv[0]; /* retain $0 */
7824 /* This realloc's G.global_argv */
7825 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7832 return EXIT_SUCCESS;
7834 /* Nothing known, so abort */
7836 bb_error_msg("set: %s: invalid option", arg);
7837 return EXIT_FAILURE;
7840 static int FAST_FUNC builtin_shift(char **argv)
7846 if (n >= 0 && n < G.global_argc) {
7847 if (G.global_args_malloced) {
7850 free(G.global_argv[m++]);
7853 memmove(&G.global_argv[1], &G.global_argv[n+1],
7854 G.global_argc * sizeof(G.global_argv[0]));
7855 return EXIT_SUCCESS;
7857 return EXIT_FAILURE;
7860 static int FAST_FUNC builtin_source(char **argv)
7865 #if ENABLE_HUSH_FUNCTIONS
7869 if (*++argv == NULL)
7870 return EXIT_FAILURE;
7872 if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
7873 input = fopen_for_read(arg_path);
7876 input = fopen_or_warn(*argv, "r");
7878 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7879 return EXIT_FAILURE;
7881 close_on_exec_on(fileno(input));
7883 #if ENABLE_HUSH_FUNCTIONS
7884 sv_flg = G.flag_return_in_progress;
7885 /* "we are inside sourced file, ok to use return" */
7886 G.flag_return_in_progress = -1;
7888 save_and_replace_G_args(&sv, argv);
7890 parse_and_run_file(input);
7893 restore_G_args(&sv, argv);
7894 #if ENABLE_HUSH_FUNCTIONS
7895 G.flag_return_in_progress = sv_flg;
7898 return G.last_exitcode;
7901 static int FAST_FUNC builtin_umask(char **argv)
7908 mode_t old_mask = mask;
7911 rc = bb_parse_mode(argv[1], &mask);
7916 * bash: umask: 'q': invalid symbolic mode operator
7917 * bash: umask: 999: octal number out of range
7919 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7924 printf("%04o\n", (unsigned) mask);
7925 /* fall through and restore mask which we set to 0 */
7929 return !rc; /* rc != 0 - success */
7932 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7933 static int FAST_FUNC builtin_unset(char **argv)
7938 /* "!": do not abort on errors */
7939 /* "+": stop at 1st non-option */
7940 opts = getopt32(argv, "!+vf");
7941 if (opts == (unsigned)-1)
7942 return EXIT_FAILURE;
7944 bb_error_msg("unset: -v and -f are exclusive");
7945 return EXIT_FAILURE;
7951 if (!(opts & 2)) { /* not -f */
7952 if (unset_local_var(*argv)) {
7953 /* unset <nonexistent_var> doesn't fail.
7954 * Error is when one tries to unset RO var.
7955 * Message was printed by unset_local_var. */
7959 #if ENABLE_HUSH_FUNCTIONS
7969 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7970 static int FAST_FUNC builtin_wait(char **argv)
7972 int ret = EXIT_SUCCESS;
7975 if (*++argv == NULL) {
7976 /* Don't care about wait results */
7977 /* Note 1: must wait until there are no more children */
7978 /* Note 2: must be interruptible */
7980 * $ sleep 3 & sleep 6 & wait
7985 * $ sleep 3 & sleep 6 & wait
7989 * ^C <-- after ~4 sec from keyboard
7992 sigaddset(&G.blocked_set, SIGCHLD);
7993 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7996 if (errno == ECHILD)
7998 /* Wait for SIGCHLD or any other signal of interest */
7999 /* sigtimedwait with infinite timeout: */
8000 sig = sigwaitinfo(&G.blocked_set, NULL);
8002 sig = check_and_run_traps(sig);
8003 if (sig && sig != SIGCHLD) { /* see note 2 */
8009 sigdelset(&G.blocked_set, SIGCHLD);
8010 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8014 /* This is probably buggy wrt interruptible-ness */
8016 pid_t pid = bb_strtou(*argv, NULL, 10);
8018 /* mimic bash message */
8019 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8020 return EXIT_FAILURE;
8022 if (waitpid(pid, &status, 0) == pid) {
8023 if (WIFSIGNALED(status))
8024 ret = 128 + WTERMSIG(status);
8025 else if (WIFEXITED(status))
8026 ret = WEXITSTATUS(status);
8030 bb_perror_msg("wait %s", *argv);
8039 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8040 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8043 def = bb_strtou(argv[1], NULL, 10);
8044 if (errno || def < def_min || argv[2]) {
8045 bb_error_msg("%s: bad arguments", argv[0]);
8053 #if ENABLE_HUSH_LOOPS
8054 static int FAST_FUNC builtin_break(char **argv)
8057 if (G.depth_of_loop == 0) {
8058 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8059 return EXIT_SUCCESS; /* bash compat */
8061 G.flag_break_continue++; /* BC_BREAK = 1 */
8063 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8064 if (depth == UINT_MAX)
8065 G.flag_break_continue = BC_BREAK;
8066 if (G.depth_of_loop < depth)
8067 G.depth_break_continue = G.depth_of_loop;
8069 return EXIT_SUCCESS;
8072 static int FAST_FUNC builtin_continue(char **argv)
8074 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8075 return builtin_break(argv);
8079 #if ENABLE_HUSH_FUNCTIONS
8080 static int FAST_FUNC builtin_return(char **argv)
8084 if (G.flag_return_in_progress != -1) {
8085 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8086 return EXIT_FAILURE; /* bash compat */
8089 G.flag_return_in_progress = 1;
8092 * out of range: wraps around at 256, does not error out
8093 * non-numeric param:
8094 * f() { false; return qwe; }; f; echo $?
8095 * bash: return: qwe: numeric argument required <== we do this
8096 * 255 <== we also do this
8098 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);