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 #if ENABLE_HUSH_BASH_COMPAT
677 BLTIN("source" , builtin_source , "Run commands in a file"),
679 BLTIN("trap" , builtin_trap , "Trap signals"),
680 BLTIN("type" , builtin_type , "Show command type"),
681 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
682 BLTIN("umask" , builtin_umask , "Set file creation mask"),
683 BLTIN("unset" , builtin_unset , "Unset variables"),
684 BLTIN("wait" , builtin_wait , "Wait for process"),
686 /* For now, echo and test are unconditionally enabled.
687 * Maybe make it configurable? */
688 static const struct built_in_command bltins2[] = {
689 BLTIN("[" , builtin_test , NULL),
690 BLTIN("echo" , builtin_echo , NULL),
692 BLTIN("printf" , builtin_printf , NULL),
694 BLTIN("pwd" , builtin_pwd , NULL),
695 BLTIN("test" , builtin_test , NULL),
702 /* prevent disasters with G.debug_indent < 0 */
703 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
704 # define debug_enter() (G.debug_indent++)
705 # define debug_leave() (G.debug_indent--)
707 # define indent() ((void)0)
708 # define debug_enter() ((void)0)
709 # define debug_leave() ((void)0)
713 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
716 #ifndef debug_printf_parse
717 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
720 #ifndef debug_printf_exec
721 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
724 #ifndef debug_printf_env
725 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
728 #ifndef debug_printf_jobs
729 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
730 # define DEBUG_JOBS 1
732 # define DEBUG_JOBS 0
735 #ifndef debug_printf_expand
736 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
737 # define DEBUG_EXPAND 1
739 # define DEBUG_EXPAND 0
742 #ifndef debug_printf_glob
743 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
744 # define DEBUG_GLOB 1
746 # define DEBUG_GLOB 0
749 #ifndef debug_printf_list
750 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
753 #ifndef debug_printf_subst
754 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
757 #ifndef debug_printf_clean
758 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
759 # define DEBUG_CLEAN 1
761 # define DEBUG_CLEAN 0
765 static void debug_print_strings(const char *prefix, char **vv)
768 fprintf(stderr, "%s:\n", prefix);
770 fprintf(stderr, " '%s'\n", *vv++);
773 # define debug_print_strings(prefix, vv) ((void)0)
777 /* Leak hunting. Use hush_leaktool.sh for post-processing.
780 static void *xxmalloc(int lineno, size_t size)
782 void *ptr = xmalloc((size + 0xff) & ~0xff);
783 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
786 static void *xxrealloc(int lineno, void *ptr, size_t size)
788 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
789 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
792 static char *xxstrdup(int lineno, const char *str)
794 char *ptr = xstrdup(str);
795 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
798 static void xxfree(void *ptr)
800 fdprintf(2, "free %p\n", ptr);
803 #define xmalloc(s) xxmalloc(__LINE__, s)
804 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
805 #define xstrdup(s) xxstrdup(__LINE__, s)
806 #define free(p) xxfree(p)
810 /* Syntax and runtime errors. They always abort scripts.
811 * In interactive use they usually discard unparsed and/or unexecuted commands
812 * and return to the prompt.
813 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
816 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
817 # define syntax_error(lineno, msg) syntax_error(msg)
818 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
819 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
820 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
821 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
824 static void die_if_script(unsigned lineno, const char *fmt, ...)
829 bb_error_msg("hush.c:%u", lineno);
832 bb_verror_msg(fmt, p, NULL);
834 if (!G_interactive_fd)
838 static void syntax_error(unsigned lineno, const char *msg)
841 die_if_script(lineno, "syntax error: %s", msg);
843 die_if_script(lineno, "syntax error", NULL);
846 static void syntax_error_at(unsigned lineno, const char *msg)
848 die_if_script(lineno, "syntax error at '%s'", msg);
851 static void syntax_error_unterm_str(unsigned lineno, const char *s)
853 die_if_script(lineno, "syntax error: unterminated %s", s);
856 /* It so happens that all such cases are totally fatal
857 * even if shell is interactive: EOF while looking for closing
858 * delimiter. There is nowhere to read stuff from after that,
859 * it's EOF! The only choice is to terminate.
861 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
862 static void syntax_error_unterm_ch(unsigned lineno, char ch)
864 char msg[2] = { ch, '\0' };
865 syntax_error_unterm_str(lineno, msg);
869 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
874 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
878 # undef die_if_script
880 # undef syntax_error_at
881 # undef syntax_error_unterm_ch
882 # undef syntax_error_unterm_str
883 # undef syntax_error_unexpected_ch
885 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
886 # define syntax_error(msg) syntax_error(__LINE__, msg)
887 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
888 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
889 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
890 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
894 #if ENABLE_HUSH_INTERACTIVE
895 static void cmdedit_update_prompt(void);
897 # define cmdedit_update_prompt() ((void)0)
903 /* Replace each \x with x in place, return ptr past NUL. */
904 static char *unbackslash(char *src)
906 char *dst = src = strchrnul(src, '\\');
910 if ((*dst++ = *src++) == '\0')
916 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
937 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
938 v[count1 + count2] = NULL;
941 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
945 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
947 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
948 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
951 #define add_strings_to_strings(strings, add, need_to_dup) \
952 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
955 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
956 static char **add_string_to_strings(char **strings, char *add)
961 return add_strings_to_strings(strings, v, /*dup:*/ 0);
964 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
966 char **ptr = add_string_to_strings(strings, add);
967 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
970 #define add_string_to_strings(strings, add) \
971 xx_add_string_to_strings(__LINE__, strings, add)
974 static void free_strings(char **strings)
989 /* Helpers for setting new $n and restoring them back
991 typedef struct save_arg_t {
995 smallint sv_g_malloced;
998 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1002 sv->sv_argv0 = argv[0];
1003 sv->sv_g_argv = G.global_argv;
1004 sv->sv_g_argc = G.global_argc;
1005 sv->sv_g_malloced = G.global_args_malloced;
1007 argv[0] = G.global_argv[0]; /* retain $0 */
1008 G.global_argv = argv;
1009 G.global_args_malloced = 0;
1017 static void restore_G_args(save_arg_t *sv, char **argv)
1021 if (G.global_args_malloced) {
1022 /* someone ran "set -- arg1 arg2 ...", undo */
1024 while (*++pp) /* note: does not free $0 */
1026 free(G.global_argv);
1028 argv[0] = sv->sv_argv0;
1029 G.global_argv = sv->sv_g_argv;
1030 G.global_argc = sv->sv_g_argc;
1031 G.global_args_malloced = sv->sv_g_malloced;
1035 /* Basic theory of signal handling in shell
1036 * ========================================
1037 * This does not describe what hush does, rather, it is current understanding
1038 * what it _should_ do. If it doesn't, it's a bug.
1039 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1041 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1042 * is finished or backgrounded. It is the same in interactive and
1043 * non-interactive shells, and is the same regardless of whether
1044 * a user trap handler is installed or a shell special one is in effect.
1045 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1046 * backgrounds (i.e. stops) or kills all members of currently running
1049 * Wait builtin in interruptible by signals for which user trap is set
1050 * or by SIGINT in interactive shell.
1052 * Trap handlers will execute even within trap handlers. (right?)
1054 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1055 * except for handlers set to '' (empty string).
1057 * If job control is off, backgrounded commands ("cmd &")
1058 * have SIGINT, SIGQUIT set to SIG_IGN.
1060 * Commands which are run in command substitution ("`cmd`")
1061 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1063 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1064 * by the shell from its parent.
1066 * Signals which differ from SIG_DFL action
1067 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1070 * SIGTERM (interactive): ignore
1071 * SIGHUP (interactive):
1072 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1073 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1074 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1075 * that all pipe members are stopped. Try this in bash:
1076 * while :; do :; done - ^Z does not background it
1077 * (while :; do :; done) - ^Z backgrounds it
1078 * SIGINT (interactive): wait for last pipe, ignore the rest
1079 * of the command line, show prompt. NB: ^C does not send SIGINT
1080 * to interactive shell while shell is waiting for a pipe,
1081 * since shell is bg'ed (is not in foreground process group).
1082 * Example 1: this waits 5 sec, but does not execute ls:
1083 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1084 * Example 2: this does not wait and does not execute ls:
1085 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1086 * Example 3: this does not wait 5 sec, but executes ls:
1087 * "sleep 5; ls -l" + press ^C
1089 * (What happens to signals which are IGN on shell start?)
1090 * (What happens with signal mask on shell start?)
1092 * Implementation in hush
1093 * ======================
1094 * We use in-kernel pending signal mask to determine which signals were sent.
1095 * We block all signals which we don't want to take action immediately,
1096 * i.e. we block all signals which need to have special handling as described
1097 * above, and all signals which have traps set.
1098 * After each pipe execution, we extract any pending signals via sigtimedwait()
1101 * unsigned non_DFL_mask: a mask of such "special" signals
1102 * sigset_t blocked_set: current blocked signal set
1105 * clear bit in blocked_set unless it is also in non_DFL_mask
1106 * "trap 'cmd' SIGxxx":
1107 * set bit in blocked_set (even if 'cmd' is '')
1108 * after [v]fork, if we plan to be a shell:
1109 * unblock signals with special interactive handling
1110 * (child shell is not interactive),
1111 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1112 * after [v]fork, if we plan to exec:
1113 * POSIX says fork clears pending signal mask in child - no need to clear it.
1114 * Restore blocked signal set to one inherited by shell just prior to exec.
1116 * Note: as a result, we do not use signal handlers much. The only uses
1117 * are to count SIGCHLDs
1118 * and to restore tty pgrp on signal-induced exit.
1121 * Standard says "When a subshell is entered, traps that are not being ignored
1122 * are set to the default actions". bash interprets it so that traps which
1123 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1126 SPECIAL_INTERACTIVE_SIGS = 0
1131 SPECIAL_JOB_SIGS = 0
1139 #if ENABLE_HUSH_FAST
1140 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1143 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1149 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1150 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1151 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1152 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1154 /* Restores tty foreground process group, and exits.
1155 * May be called as signal handler for fatal signal
1156 * (will resend signal to itself, producing correct exit state)
1157 * or called directly with -EXITCODE.
1158 * We also call it if xfunc is exiting. */
1159 static void sigexit(int sig) NORETURN;
1160 static void sigexit(int sig)
1162 /* Disable all signals: job control, SIGPIPE, etc. */
1163 sigprocmask_allsigs(SIG_BLOCK);
1165 /* Careful: we can end up here after [v]fork. Do not restore
1166 * tty pgrp then, only top-level shell process does that */
1167 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1168 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1170 /* Not a signal, just exit */
1174 kill_myself_with_sig(sig); /* does not return */
1178 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1179 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1183 /* Restores tty foreground process group, and exits. */
1184 static void hush_exit(int exitcode) NORETURN;
1185 static void hush_exit(int exitcode)
1187 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1188 /* Prevent recursion:
1189 * trap "echo Hi; exit" EXIT; exit
1191 char *argv[] = { NULL, G.traps[0], NULL };
1200 sigexit(- (exitcode & 0xff));
1206 static int check_and_run_traps(int sig)
1208 static const struct timespec zero_timespec = { 0, 0 };
1209 smalluint save_rcode;
1215 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1220 if (G.traps && G.traps[sig]) {
1221 if (G.traps[sig][0]) {
1222 /* We have user-defined handler */
1223 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1224 save_rcode = G.last_exitcode;
1227 G.last_exitcode = save_rcode;
1228 } /* else: "" trap, ignoring signal */
1231 /* not a trap: special action */
1233 #if ENABLE_HUSH_FAST
1236 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1240 /* Builtin was ^C'ed, make it look prettier: */
1247 /* bash is observed to signal whole process groups,
1248 * not individual processes */
1249 for (job = G.job_list; job; job = job->next) {
1252 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1253 if (kill(- job->pgrp, SIGHUP) == 0)
1254 kill(- job->pgrp, SIGCONT);
1259 default: /* ignored: */
1260 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1268 static const char *get_cwd(int force)
1270 if (force || G.cwd == NULL) {
1271 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1272 * we must not try to free(bb_msg_unknown) */
1273 if (G.cwd == bb_msg_unknown)
1275 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1277 G.cwd = bb_msg_unknown;
1284 * Shell and environment variable support
1286 static struct variable **get_ptr_to_local_var(const char *name)
1288 struct variable **pp;
1289 struct variable *cur;
1294 while ((cur = *pp) != NULL) {
1295 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1302 static struct variable *get_local_var(const char *name)
1304 struct variable **pp = get_ptr_to_local_var(name);
1310 static const char* FAST_FUNC get_local_var_value(const char *name)
1312 struct variable **pp = get_ptr_to_local_var(name);
1314 return strchr((*pp)->varstr, '=') + 1;
1315 if (strcmp(name, "PPID") == 0)
1316 return utoa(G.root_ppid);
1317 // bash compat: UID? EUID?
1318 #if ENABLE_HUSH_RANDOM_SUPPORT
1319 if (strcmp(name, "RANDOM") == 0) {
1320 return utoa(next_random(&G.random_gen));
1326 /* str holds "NAME=VAL" and is expected to be malloced.
1327 * We take ownership of it.
1329 * 0: do not change export flag
1330 * (if creating new variable, flag will be 0)
1331 * 1: set export flag and putenv the variable
1332 * -1: clear export flag and unsetenv the variable
1333 * flg_read_only is set only when we handle -R var=val
1335 #if !BB_MMU && ENABLE_HUSH_LOCAL
1336 /* all params are used */
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, local_lvl)
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)
1343 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1344 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1345 set_local_var(str, flg_export, flg_read_only)
1347 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1349 struct variable **var_pp;
1350 struct variable *cur;
1354 eq_sign = strchr(str, '=');
1355 if (!eq_sign) { /* not expected to ever happen? */
1360 name_len = eq_sign - str + 1; /* including '=' */
1361 var_pp = &G.top_var;
1362 while ((cur = *var_pp) != NULL) {
1363 if (strncmp(cur->varstr, str, name_len) != 0) {
1364 var_pp = &cur->next;
1367 /* We found an existing var with this name */
1368 if (cur->flg_read_only) {
1372 bb_error_msg("%s: readonly variable", str);
1376 if (flg_export == -1) { // "&& cur->flg_export" ?
1377 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1382 #if ENABLE_HUSH_LOCAL
1383 if (cur->func_nest_level < local_lvl) {
1384 /* New variable is declared as local,
1385 * and existing one is global, or local
1386 * from enclosing function.
1387 * Remove and save old one: */
1388 *var_pp = cur->next;
1389 cur->next = *G.shadowed_vars_pp;
1390 *G.shadowed_vars_pp = cur;
1391 /* bash 3.2.33(1) and exported vars:
1393 * # f() { local z=a; env | grep ^z; }
1399 if (cur->flg_export)
1404 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1409 if (cur->max_len != 0) {
1410 if (cur->max_len >= strlen(str)) {
1411 /* This one is from startup env, reuse space */
1412 strcpy(cur->varstr, str);
1416 /* max_len == 0 signifies "malloced" var, which we can
1417 * (and has to) free */
1421 goto set_str_and_exp;
1424 /* Not found - create new variable struct */
1425 cur = xzalloc(sizeof(*cur));
1426 #if ENABLE_HUSH_LOCAL
1427 cur->func_nest_level = local_lvl;
1429 cur->next = *var_pp;
1435 cur->flg_read_only = flg_read_only;
1438 if (flg_export == 1)
1439 cur->flg_export = 1;
1440 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1441 cmdedit_update_prompt();
1442 if (cur->flg_export) {
1443 if (flg_export == -1) {
1444 cur->flg_export = 0;
1445 /* unsetenv was already done */
1447 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1448 return putenv(cur->varstr);
1454 /* Used at startup and after each cd */
1455 static void set_pwd_var(int exp)
1457 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1458 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1461 static int unset_local_var_len(const char *name, int name_len)
1463 struct variable *cur;
1464 struct variable **var_pp;
1467 return EXIT_SUCCESS;
1468 var_pp = &G.top_var;
1469 while ((cur = *var_pp) != NULL) {
1470 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1471 if (cur->flg_read_only) {
1472 bb_error_msg("%s: readonly variable", name);
1473 return EXIT_FAILURE;
1475 *var_pp = cur->next;
1476 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1477 bb_unsetenv(cur->varstr);
1478 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1479 cmdedit_update_prompt();
1483 return EXIT_SUCCESS;
1485 var_pp = &cur->next;
1487 return EXIT_SUCCESS;
1490 static int unset_local_var(const char *name)
1492 return unset_local_var_len(name, strlen(name));
1495 static void unset_vars(char **strings)
1503 const char *eq = strchrnul(*v, '=');
1504 unset_local_var_len(*v, (int)(eq - *v));
1510 #if ENABLE_SH_MATH_SUPPORT
1511 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1512 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1513 static char* FAST_FUNC endofname(const char *name)
1521 if (!is_in_name(*p))
1528 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1530 char *var = xasprintf("%s=%s", name, val);
1531 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1536 * Helpers for "var1=val1 var2=val2 cmd" feature
1538 static void add_vars(struct variable *var)
1540 struct variable *next;
1544 var->next = G.top_var;
1546 if (var->flg_export) {
1547 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1548 putenv(var->varstr);
1550 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1556 static struct variable *set_vars_and_save_old(char **strings)
1559 struct variable *old = NULL;
1565 struct variable *var_p;
1566 struct variable **var_pp;
1569 eq = strchr(*s, '=');
1572 var_pp = get_ptr_to_local_var(*s);
1575 /* Remove variable from global linked list */
1577 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1578 *var_pp = var_p->next;
1579 /* Add it to returned list */
1583 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1594 static int FAST_FUNC static_get(struct in_str *i)
1603 static int FAST_FUNC static_peek(struct in_str *i)
1608 #if ENABLE_HUSH_INTERACTIVE
1610 static void cmdedit_update_prompt(void)
1612 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1613 G.PS1 = get_local_var_value("PS1");
1616 G.PS2 = get_local_var_value("PS2");
1624 static const char* setup_prompt_string(int promptmode)
1626 const char *prompt_str;
1627 debug_printf("setup_prompt_string %d ", promptmode);
1628 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1629 /* Set up the prompt */
1630 if (promptmode == 0) { /* PS1 */
1632 /* bash uses $PWD value, even if it is set by user.
1633 * It uses current dir only if PWD is unset.
1634 * We always use current dir. */
1635 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1640 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1641 debug_printf("result '%s'\n", prompt_str);
1645 static void get_user_input(struct in_str *i)
1648 const char *prompt_str;
1650 prompt_str = setup_prompt_string(i->promptmode);
1651 #if ENABLE_FEATURE_EDITING
1652 /* Enable command line editing only while a command line
1653 * is actually being read */
1656 /* buglet: SIGINT will not make new prompt to appear _at once_,
1657 * only after <Enter>. (^C will work) */
1658 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1659 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1660 check_and_run_traps(0);
1661 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1662 i->eof_flag = (r < 0);
1663 if (i->eof_flag) { /* EOF/error detected */
1664 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1665 G.user_input_buf[1] = '\0';
1670 fputs(prompt_str, stdout);
1672 G.user_input_buf[0] = r = fgetc(i->file);
1673 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1674 //do we need check_and_run_traps(0)? (maybe only if stdin)
1675 } while (G.flag_SIGINT);
1676 i->eof_flag = (r == EOF);
1678 i->p = G.user_input_buf;
1681 #endif /* INTERACTIVE */
1683 /* This is the magic location that prints prompts
1684 * and gets data back from the user */
1685 static int FAST_FUNC file_get(struct in_str *i)
1689 /* If there is data waiting, eat it up */
1690 if (i->p && *i->p) {
1691 #if ENABLE_HUSH_INTERACTIVE
1695 if (i->eof_flag && !*i->p)
1697 /* note: ch is never NUL */
1699 /* need to double check i->file because we might be doing something
1700 * more complicated by now, like sourcing or substituting. */
1701 #if ENABLE_HUSH_INTERACTIVE
1702 if (G_interactive_fd && i->promptme && i->file == stdin) {
1705 } while (!*i->p); /* need non-empty line */
1706 i->promptmode = 1; /* PS2 */
1711 do ch = fgetc(i->file); while (ch == '\0');
1713 debug_printf("file_get: got '%c' %d\n", ch, ch);
1714 #if ENABLE_HUSH_INTERACTIVE
1721 /* All callers guarantee this routine will never
1722 * be used right after a newline, so prompting is not needed.
1724 static int FAST_FUNC file_peek(struct in_str *i)
1727 if (i->p && *i->p) {
1728 if (i->eof_flag && !i->p[1])
1731 /* note: ch is never NUL */
1733 do ch = fgetc(i->file); while (ch == '\0');
1734 i->eof_flag = (ch == EOF);
1735 i->peek_buf[0] = ch;
1736 i->peek_buf[1] = '\0';
1738 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1742 static void setup_file_in_str(struct in_str *i, FILE *f)
1744 i->peek = file_peek;
1746 #if ENABLE_HUSH_INTERACTIVE
1748 i->promptmode = 0; /* PS1 */
1754 static void setup_string_in_str(struct in_str *i, const char *s)
1756 i->peek = static_peek;
1757 i->get = static_get;
1758 #if ENABLE_HUSH_INTERACTIVE
1760 i->promptmode = 0; /* PS1 */
1770 #define B_CHUNK (32 * sizeof(char*))
1772 static void o_reset_to_empty_unquoted(o_string *o)
1780 static void o_free(o_string *o)
1783 memset(o, 0, sizeof(*o));
1786 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1791 static void o_grow_by(o_string *o, int len)
1793 if (o->length + len > o->maxlen) {
1794 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1795 o->data = xrealloc(o->data, 1 + o->maxlen);
1799 static void o_addchr(o_string *o, int ch)
1801 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1803 o->data[o->length] = ch;
1805 o->data[o->length] = '\0';
1808 static void o_addblock(o_string *o, const char *str, int len)
1811 memcpy(&o->data[o->length], str, len);
1813 o->data[o->length] = '\0';
1817 static void o_addstr(o_string *o, const char *str)
1819 o_addblock(o, str, strlen(str));
1821 static void nommu_addchr(o_string *o, int ch)
1827 # define nommu_addchr(o, str) ((void)0)
1830 static void o_addstr_with_NUL(o_string *o, const char *str)
1832 o_addblock(o, str, strlen(str) + 1);
1835 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1840 && (*str != '*' && *str != '?' && *str != '[')
1848 #undef HUSH_BRACE_EXP
1850 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1851 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1852 * Apparently, on unquoted $v bash still does globbing
1853 * ("v='*.txt'; echo $v" prints all .txt files),
1854 * but NOT brace expansion! Thus, there should be TWO independent
1855 * quoting mechanisms on $v expansion side: one protects
1856 * $v from brace expansion, and other additionally protects "$v" against globbing.
1857 * We have only second one.
1860 #ifdef HUSH_BRACE_EXP
1861 # define MAYBE_BRACES "{}"
1863 # define MAYBE_BRACES ""
1866 /* My analysis of quoting semantics tells me that state information
1867 * is associated with a destination, not a source.
1869 static void o_addqchr(o_string *o, int ch)
1872 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1877 o->data[o->length] = '\\';
1880 o->data[o->length] = ch;
1882 o->data[o->length] = '\0';
1885 static void o_addQchr(o_string *o, int ch)
1888 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1890 o->data[o->length] = '\\';
1894 o->data[o->length] = ch;
1896 o->data[o->length] = '\0';
1899 static void o_addQstr(o_string *o, const char *str, int len)
1902 o_addblock(o, str, len);
1908 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1909 if (ordinary_cnt > len) /* paranoia */
1911 o_addblock(o, str, ordinary_cnt);
1912 if (ordinary_cnt == len)
1914 str += ordinary_cnt;
1915 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1919 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1921 o->data[o->length] = '\\';
1925 o->data[o->length] = ch;
1927 o->data[o->length] = '\0';
1931 /* A special kind of o_string for $VAR and `cmd` expansion.
1932 * It contains char* list[] at the beginning, which is grown in 16 element
1933 * increments. Actual string data starts at the next multiple of 16 * (char*).
1934 * list[i] contains an INDEX (int!) into this string data.
1935 * It means that if list[] needs to grow, data needs to be moved higher up
1936 * but list[i]'s need not be modified.
1937 * NB: remembering how many list[i]'s you have there is crucial.
1938 * o_finalize_list() operation post-processes this structure - calculates
1939 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1941 #if DEBUG_EXPAND || DEBUG_GLOB
1942 static void debug_print_list(const char *prefix, o_string *o, int n)
1944 char **list = (char**)o->data;
1945 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1949 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1950 prefix, list, n, string_start, o->length, o->maxlen);
1953 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1954 o->data + (int)list[i] + string_start,
1955 o->data + (int)list[i] + string_start);
1959 const char *p = o->data + (int)list[n - 1] + string_start;
1961 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1965 # define debug_print_list(prefix, o, n) ((void)0)
1968 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1969 * in list[n] so that it points past last stored byte so far.
1970 * It returns n+1. */
1971 static int o_save_ptr_helper(o_string *o, int n)
1973 char **list = (char**)o->data;
1977 if (!o->has_empty_slot) {
1978 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1979 string_len = o->length - string_start;
1980 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1981 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1982 /* list[n] points to string_start, make space for 16 more pointers */
1983 o->maxlen += 0x10 * sizeof(list[0]);
1984 o->data = xrealloc(o->data, o->maxlen + 1);
1985 list = (char**)o->data;
1986 memmove(list + n + 0x10, list + n, string_len);
1987 o->length += 0x10 * sizeof(list[0]);
1989 debug_printf_list("list[%d]=%d string_start=%d\n",
1990 n, string_len, string_start);
1993 /* We have empty slot at list[n], reuse without growth */
1994 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1995 string_len = o->length - string_start;
1996 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1997 n, string_len, string_start);
1998 o->has_empty_slot = 0;
2000 list[n] = (char*)(ptrdiff_t)string_len;
2004 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2005 static int o_get_last_ptr(o_string *o, int n)
2007 char **list = (char**)o->data;
2008 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2010 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2013 #ifdef HUSH_BRACE_EXP
2014 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2015 * first, it processes even {a} (no commas), second,
2016 * I didn't manage to make it return strings when they don't match
2017 * existing files. Need to re-implement it.
2021 static int glob_needed(const char *s)
2030 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2036 /* Return pointer to next closing brace or to comma */
2037 static const char *next_brace_sub(const char *cp)
2041 while (*cp != '\0') {
2048 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2050 if (*cp++ == '{') /*}*/
2054 return *cp != '\0' ? cp : NULL;
2056 /* Recursive brace globber. Note: may garble pattern[]. */
2057 static int glob_brace(char *pattern, o_string *o, int n)
2059 char *new_pattern_buf;
2066 debug_printf_glob("glob_brace('%s')\n", pattern);
2072 if (*begin == '{') /*}*/ {
2073 /* Find the first sub-pattern and at the same time
2074 * find the rest after the closing brace */
2075 next = next_brace_sub(begin);
2077 /* An illegal expression */
2080 /*{*/ if (*next == '}') {
2081 /* "{abc}" with no commas - illegal
2082 * brace expr, disregard and skip it */
2088 if (*begin == '\\' && begin[1] != '\0')
2092 debug_printf_glob("begin:%s\n", begin);
2093 debug_printf_glob("next:%s\n", next);
2095 /* Now find the end of the whole brace expression */
2097 /*{*/ while (*rest != '}') {
2098 rest = next_brace_sub(rest);
2100 /* An illegal expression */
2103 debug_printf_glob("rest:%s\n", rest);
2105 rest_len = strlen(++rest) + 1;
2107 /* We are sure the brace expression is well-formed */
2109 /* Allocate working buffer large enough for our work */
2110 new_pattern_buf = xmalloc(strlen(pattern));
2112 /* We have a brace expression. BEGIN points to the opening {,
2113 * NEXT points past the terminator of the first element, and REST
2114 * points past the final }. We will accumulate result names from
2115 * recursive runs for each brace alternative in the buffer using
2120 /* Construct the new glob expression */
2123 mempcpy(new_pattern_buf,
2124 /* We know the prefix for all sub-patterns */
2125 pattern, begin - pattern),
2129 /* Note: glob_brace() may garble new_pattern_buf[].
2130 * That's why we re-copy prefix every time (1st memcpy above).
2132 n = glob_brace(new_pattern_buf, o, n);
2133 /*{*/ if (*next == '}') {
2134 /* We saw the last entry */
2138 next = next_brace_sub(next);
2140 free(new_pattern_buf);
2148 memset(&globdata, 0, sizeof(globdata));
2149 gr = glob(pattern, 0, NULL, &globdata);
2150 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2152 if (gr == GLOB_NOMATCH) {
2153 globfree(&globdata);
2154 /* NB: garbles parameter */
2155 unbackslash(pattern);
2156 o_addstr_with_NUL(o, pattern);
2157 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2158 return o_save_ptr_helper(o, n);
2160 if (gr == GLOB_NOSPACE)
2161 bb_error_msg_and_die(bb_msg_memory_exhausted);
2162 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2163 * but we didn't specify it. Paranoia again. */
2164 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2166 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2167 char **argv = globdata.gl_pathv;
2169 o_addstr_with_NUL(o, *argv);
2170 n = o_save_ptr_helper(o, n);
2176 globfree(&globdata);
2180 /* Performs globbing on last list[],
2181 * saving each result as a new list[].
2183 static int o_glob(o_string *o, int n)
2185 char *pattern, *copy;
2187 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2189 return o_save_ptr_helper(o, n);
2190 pattern = o->data + o_get_last_ptr(o, n);
2191 debug_printf_glob("glob pattern '%s'\n", pattern);
2192 if (!glob_needed(pattern)) {
2193 /* unbackslash last string in o in place, fix length */
2194 o->length = unbackslash(pattern) - o->data;
2195 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2196 return o_save_ptr_helper(o, n);
2199 copy = xstrdup(pattern);
2200 /* "forget" pattern in o */
2201 o->length = pattern - o->data;
2202 n = glob_brace(copy, o, n);
2205 debug_print_list("o_glob returning", o, n);
2212 static int glob_needed(const char *s)
2221 if (*s == '*' || *s == '[' || *s == '?')
2227 /* Performs globbing on last list[],
2228 * saving each result as a new list[].
2230 static int o_glob(o_string *o, int n)
2236 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2238 return o_save_ptr_helper(o, n);
2239 pattern = o->data + o_get_last_ptr(o, n);
2240 debug_printf_glob("glob pattern '%s'\n", pattern);
2241 if (!glob_needed(pattern)) {
2243 /* unbackslash last string in o in place, fix length */
2244 o->length = unbackslash(pattern) - o->data;
2245 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2246 return o_save_ptr_helper(o, n);
2249 memset(&globdata, 0, sizeof(globdata));
2250 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2251 * If we glob "*.\*" and don't find anything, we need
2252 * to fall back to using literal "*.*", but GLOB_NOCHECK
2253 * will return "*.\*"!
2255 gr = glob(pattern, 0, NULL, &globdata);
2256 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2258 if (gr == GLOB_NOMATCH) {
2259 globfree(&globdata);
2262 if (gr == GLOB_NOSPACE)
2263 bb_error_msg_and_die(bb_msg_memory_exhausted);
2264 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2265 * but we didn't specify it. Paranoia again. */
2266 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2268 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2269 char **argv = globdata.gl_pathv;
2270 /* "forget" pattern in o */
2271 o->length = pattern - o->data;
2273 o_addstr_with_NUL(o, *argv);
2274 n = o_save_ptr_helper(o, n);
2280 globfree(&globdata);
2282 debug_print_list("o_glob returning", o, n);
2288 /* If o->o_glob == 1, glob the string so far remembered.
2289 * Otherwise, just finish current list[] and start new */
2290 static int o_save_ptr(o_string *o, int n)
2292 if (o->o_glob) { /* if globbing is requested */
2293 /* If o->has_empty_slot, list[n] was already globbed
2294 * (if it was requested back then when it was filled)
2295 * so don't do that again! */
2296 if (!o->has_empty_slot)
2297 return o_glob(o, n); /* o_save_ptr_helper is inside */
2299 return o_save_ptr_helper(o, n);
2302 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2303 static char **o_finalize_list(o_string *o, int n)
2308 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2310 debug_print_list("finalized", o, n);
2311 debug_printf_expand("finalized n:%d\n", n);
2312 list = (char**)o->data;
2313 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2317 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2323 /* Expansion can recurse */
2324 #if ENABLE_HUSH_TICK
2325 static int process_command_subs(o_string *dest, const char *s);
2327 static char *expand_string_to_string(const char *str);
2329 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2330 parse_stream_dquoted(dest, input, dquote_end)
2332 static int parse_stream_dquoted(o_string *as_string,
2334 struct in_str *input,
2337 /* expand_strvec_to_strvec() takes a list of strings, expands
2338 * all variable references within and returns a pointer to
2339 * a list of expanded strings, possibly with larger number
2340 * of strings. (Think VAR="a b"; echo $VAR).
2341 * This new list is allocated as a single malloc block.
2342 * NULL-terminated list of char* pointers is at the beginning of it,
2343 * followed by strings themself.
2344 * Caller can deallocate entire list by single free(list). */
2346 /* Store given string, finalizing the word and starting new one whenever
2347 * we encounter IFS char(s). This is used for expanding variable values.
2348 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2349 static int expand_on_ifs(o_string *output, int n, const char *str)
2352 int word_len = strcspn(str, G.ifs);
2354 if (output->o_escape || !output->o_glob)
2355 o_addQstr(output, str, word_len);
2356 else /* protect backslashes against globbing up :) */
2357 o_addblock_duplicate_backslash(output, str, word_len);
2360 if (!*str) /* EOL - do not finalize word */
2362 o_addchr(output, '\0');
2363 debug_print_list("expand_on_ifs", output, n);
2364 n = o_save_ptr(output, n);
2365 str += strspn(str, G.ifs); /* skip ifs chars */
2367 debug_print_list("expand_on_ifs[1]", output, n);
2371 /* Helper to expand $((...)) and heredoc body. These act as if
2372 * they are in double quotes, with the exception that they are not :).
2373 * Just the rules are similar: "expand only $var and `cmd`"
2375 * Returns malloced string.
2376 * As an optimization, we return NULL if expansion is not needed.
2378 static char *expand_pseudo_dquoted(const char *str)
2381 struct in_str input;
2382 o_string dest = NULL_O_STRING;
2384 if (strchr(str, '$') == NULL
2385 #if ENABLE_HUSH_TICK
2386 && strchr(str, '`') == NULL
2392 /* We need to expand. Example:
2393 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2395 setup_string_in_str(&input, str);
2396 parse_stream_dquoted(NULL, &dest, &input, EOF);
2397 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2398 exp_str = expand_string_to_string(dest.data);
2399 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2400 o_free_unsafe(&dest);
2404 /* Expand all variable references in given string, adding words to list[]
2405 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2406 * to be filled). This routine is extremely tricky: has to deal with
2407 * variables/parameters with whitespace, $* and $@, and constructs like
2408 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2409 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2411 /* or_mask is either 0 (normal case) or 0x80 -
2412 * expansion of right-hand side of assignment == 1-element expand.
2413 * It will also do no globbing, and thus we must not backslash-quote!
2420 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2421 debug_print_list("expand_vars_to_list", output, n);
2422 n = o_save_ptr(output, n);
2423 debug_print_list("expand_vars_to_list[0]", output, n);
2425 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2428 char *dyn_val = NULL;
2429 const char *val = NULL;
2430 #if ENABLE_HUSH_TICK
2431 o_string subst_result = NULL_O_STRING;
2433 #if ENABLE_SH_MATH_SUPPORT
2434 char arith_buf[sizeof(arith_t)*3 + 2];
2436 o_addblock(output, arg, p - arg);
2437 debug_print_list("expand_vars_to_list[1]", output, n);
2439 p = strchr(p, SPECIAL_VAR_SYMBOL);
2441 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2442 /* "$@" is special. Even if quoted, it can still
2443 * expand to nothing (not even an empty string) */
2444 if ((first_ch & 0x7f) != '@')
2445 ored_ch |= first_ch;
2447 switch (first_ch & 0x7f) {
2448 /* Highest bit in first_ch indicates that var is double-quoted */
2450 val = utoa(G.root_pid);
2452 case '!': /* bg pid */
2453 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2455 case '?': /* exitcode */
2456 val = utoa(G.last_exitcode);
2458 case '#': /* argc */
2459 if (arg[1] != SPECIAL_VAR_SYMBOL)
2460 /* actually, it's a ${#var} */
2462 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2467 if (!G.global_argv[i])
2469 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2470 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2471 smallint sv = output->o_escape;
2472 /* unquoted var's contents should be globbed, so don't escape */
2473 output->o_escape = 0;
2474 while (G.global_argv[i]) {
2475 n = expand_on_ifs(output, n, G.global_argv[i]);
2476 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2477 if (G.global_argv[i++][0] && G.global_argv[i]) {
2478 /* this argv[] is not empty and not last:
2479 * put terminating NUL, start new word */
2480 o_addchr(output, '\0');
2481 debug_print_list("expand_vars_to_list[2]", output, n);
2482 n = o_save_ptr(output, n);
2483 debug_print_list("expand_vars_to_list[3]", output, n);
2486 output->o_escape = sv;
2488 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2489 * and in this case should treat it like '$*' - see 'else...' below */
2490 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2492 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2493 if (++i >= G.global_argc)
2495 o_addchr(output, '\0');
2496 debug_print_list("expand_vars_to_list[4]", output, n);
2497 n = o_save_ptr(output, n);
2499 } else { /* quoted $*: add as one word */
2501 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2502 if (!G.global_argv[++i])
2505 o_addchr(output, G.ifs[0]);
2509 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2510 /* "Empty variable", used to make "" etc to not disappear */
2514 #if ENABLE_HUSH_TICK
2515 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2518 /* Can't just stuff it into output o_string,
2519 * expanded result may need to be globbed
2520 * and $IFS-splitted */
2521 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2522 G.last_exitcode = process_command_subs(&subst_result, arg);
2523 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2524 val = subst_result.data;
2527 #if ENABLE_SH_MATH_SUPPORT
2528 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2529 arith_eval_hooks_t hooks;
2534 arg++; /* skip '+' */
2535 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2536 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2538 exp_str = expand_pseudo_dquoted(arg);
2539 hooks.lookupvar = get_local_var_value;
2540 hooks.setvar = set_local_var_from_halves;
2541 hooks.endofname = endofname;
2542 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2546 const char *msg = "error in arithmetic";
2549 msg = "exponent less than 0";
2552 msg = "divide by 0";
2555 msg = "expression recursion loop detected";
2560 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2561 sprintf(arith_buf, arith_t_fmt, res);
2566 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2568 bool exp_len = false;
2569 bool exp_null = false;
2571 char exp_save = exp_save; /* for compiler */
2572 char exp_op = exp_op; /* for compiler */
2573 char *exp_word = exp_word; /* for compiler */
2577 arg[0] = first_ch & 0x7f;
2579 /* prepare for expansions */
2580 if (var[0] == '#') {
2581 /* handle length expansion ${#var} */
2585 /* maybe handle parameter expansion */
2586 exp_off = strcspn(var, ":-=+?%#");
2590 exp_save = var[exp_off];
2591 exp_null = exp_save == ':';
2592 exp_word = var + exp_off;
2595 exp_op = *exp_word++;
2596 var[exp_off] = '\0';
2600 /* lookup the variable in question */
2601 if (isdigit(var[0])) {
2602 /* handle_dollar() should have vetted var for us */
2604 if (i < G.global_argc)
2605 val = G.global_argv[i];
2606 /* else val remains NULL: $N with too big N */
2608 val = get_local_var_value(var);
2610 /* handle any expansions */
2612 debug_printf_expand("expand: length of '%s' = ", val);
2613 val = utoa(val ? strlen(val) : 0);
2614 debug_printf_expand("%s\n", val);
2615 } else if (exp_off) {
2616 if (exp_op == '%' || exp_op == '#') {
2618 /* we need to do a pattern match */
2621 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2622 if (exp_op == *exp_word) /* ## or %% */
2624 val = dyn_val = xstrdup(val);
2625 loc = scan(dyn_val, exp_word, match_at_left);
2626 if (match_at_left) /* # or ## */
2628 else if (loc) /* % or %% and match was found */
2632 /* we need to do an expansion */
2633 int exp_test = (!val || (exp_null && !val[0]));
2635 exp_test = !exp_test;
2636 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2637 exp_null ? "true" : "false", exp_test);
2639 if (exp_op == '?') {
2640 //TODO: how interactive bash aborts expansion mid-command?
2641 /* ${var?[error_msg_if_unset]} */
2642 /* ${var:?[error_msg_if_unset_or_null]} */
2643 /* mimic bash message */
2644 die_if_script("%s: %s",
2646 exp_word[0] ? exp_word : "parameter null or not set"
2652 if (exp_op == '=') {
2653 /* ${var=[word]} or ${var:=[word]} */
2654 if (isdigit(var[0]) || var[0] == '#') {
2655 /* mimic bash message */
2656 die_if_script("$%s: cannot assign in this way", var);
2659 char *new_var = xasprintf("%s=%s", var, val);
2660 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2666 var[exp_off] = exp_save;
2670 #if ENABLE_HUSH_TICK
2673 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2674 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2676 /* unquoted var's contents should be globbed, so don't escape */
2677 smallint sv = output->o_escape;
2678 output->o_escape = 0;
2679 n = expand_on_ifs(output, n, val);
2681 output->o_escape = sv;
2683 } else { /* quoted $VAR, val will be appended below */
2684 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2687 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2690 o_addQstr(output, val, strlen(val));
2693 /* Do the check to avoid writing to a const string */
2694 if (*p != SPECIAL_VAR_SYMBOL)
2695 *p = SPECIAL_VAR_SYMBOL;
2697 #if ENABLE_HUSH_TICK
2698 o_free(&subst_result);
2701 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2704 debug_print_list("expand_vars_to_list[a]", output, n);
2705 /* this part is literal, and it was already pre-quoted
2706 * if needed (much earlier), do not use o_addQstr here! */
2707 o_addstr_with_NUL(output, arg);
2708 debug_print_list("expand_vars_to_list[b]", output, n);
2709 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2710 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2713 /* allow to reuse list[n] later without re-growth */
2714 output->has_empty_slot = 1;
2716 o_addchr(output, '\0');
2721 static char **expand_variables(char **argv, int or_mask)
2726 o_string output = NULL_O_STRING;
2728 if (or_mask & 0x100) {
2729 output.o_escape = 1; /* protect against globbing for "$var" */
2730 /* (unquoted $var will temporarily switch it off) */
2737 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2740 debug_print_list("expand_variables", &output, n);
2742 /* output.data (malloced in one block) gets returned in "list" */
2743 list = o_finalize_list(&output, n);
2744 debug_print_strings("expand_variables[1]", list);
2748 static char **expand_strvec_to_strvec(char **argv)
2750 return expand_variables(argv, 0x100);
2753 #if ENABLE_HUSH_BASH_COMPAT
2754 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2756 return expand_variables(argv, 0x80);
2760 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2761 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2766 o_string output = NULL_O_STRING;
2771 int is_var = is_well_formed_var_name(*v, '=');
2772 /* is_var * 0x80: singleword expansion for vars */
2773 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2775 /* Subtle! expand_vars_to_list did not glob last word yet.
2776 * It does this only when fed with further data.
2777 * Therefore we set globbing flags AFTER it, not before:
2780 /* if it is not recognizably abc=...; then: */
2781 output.o_escape = !is_var; /* protect against globbing for "$var" */
2782 /* (unquoted $var will temporarily switch it off) */
2783 output.o_glob = !is_var; /* and indeed do globbing */
2786 debug_print_list("expand_cond", &output, n);
2788 /* output.data (malloced in one block) gets returned in "list" */
2789 list = o_finalize_list(&output, n);
2790 debug_print_strings("expand_cond[1]", list);
2795 /* Used for expansion of right hand of assignments */
2796 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2798 static char *expand_string_to_string(const char *str)
2800 char *argv[2], **list;
2802 argv[0] = (char*)str;
2804 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2806 if (!list[0] || list[1])
2807 bb_error_msg_and_die("BUG in varexp2");
2808 /* actually, just move string 2*sizeof(char*) bytes back */
2809 overlapping_strcpy((char*)list, list[0]);
2810 unbackslash((char*)list);
2811 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2815 /* Used for "eval" builtin */
2816 static char* expand_strvec_to_string(char **argv)
2820 list = expand_variables(argv, 0x80);
2821 /* Convert all NULs to spaces */
2826 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2827 bb_error_msg_and_die("BUG in varexp3");
2828 /* bash uses ' ' regardless of $IFS contents */
2833 overlapping_strcpy((char*)list, list[0]);
2834 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2838 static char **expand_assignments(char **argv, int count)
2842 /* Expand assignments into one string each */
2843 for (i = 0; i < count; i++) {
2844 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2852 void re_execute_shell(char ***to_free, const char *s,
2853 char *g_argv0, char **g_argv,
2854 char **builtin_argv) NORETURN;
2856 static void reset_traps_to_defaults(void)
2858 /* This function is always called in a child shell
2859 * after fork (not vfork, NOMMU doesn't use this function).
2864 /* Child shells are not interactive.
2865 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2866 * Testcase: (while :; do :; done) + ^Z should background.
2867 * Same goes for SIGTERM, SIGHUP, SIGINT.
2869 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2870 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2872 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2873 * Stupid. It can be done with *single* &= op, but we can't use
2874 * the fact that G.blocked_set is implemented as a bitmask
2876 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2880 /* Careful. Only if no trap or trap is not "" */
2881 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2882 sigdelset(&G.blocked_set, sig);
2889 /* Our homegrown sig mask is saner to work with :) */
2890 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2892 /* Resetting all traps to default except empty ones */
2893 mask = G.non_DFL_mask;
2894 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2895 if (!G.traps[sig] || !G.traps[sig][0])
2898 G.traps[sig] = NULL;
2899 /* There is no signal for 0 (EXIT) */
2902 /* There was a trap handler, we just removed it.
2903 * But if sig still has non-DFL handling,
2904 * we should not unblock the sig. */
2907 sigdelset(&G.blocked_set, sig);
2909 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2914 static void re_execute_shell(char ***to_free, const char *s,
2915 char *g_argv0, char **g_argv,
2916 char **builtin_argv) NORETURN;
2917 static void re_execute_shell(char ***to_free, const char *s,
2918 char *g_argv0, char **g_argv,
2919 char **builtin_argv)
2921 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
2922 /* delims + 2 * (number of bytes in printed hex numbers) */
2923 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
2924 char *heredoc_argv[4];
2925 struct variable *cur;
2926 # if ENABLE_HUSH_FUNCTIONS
2927 struct function *funcp;
2931 unsigned long long empty_trap_mask;
2933 if (!g_argv0) { /* heredoc */
2934 argv = heredoc_argv;
2935 argv[0] = (char *) G.argv0_for_re_execing;
2936 argv[1] = (char *) "-<";
2937 argv[2] = (char *) s;
2939 pp = &argv[3]; /* used as pointer to empty environment */
2945 if (pp) while (*pp++)
2948 empty_trap_mask = 0;
2951 for (sig = 1; sig < NSIG; sig++) {
2952 if (G.traps[sig] && !G.traps[sig][0])
2953 empty_trap_mask |= 1LL << sig;
2957 sprintf(param_buf, NOMMU_HACK_FMT
2958 , (unsigned) G.root_pid
2959 , (unsigned) G.root_ppid
2960 , (unsigned) G.last_bg_pid
2961 , (unsigned) G.last_exitcode
2964 IF_HUSH_LOOPS(, G.depth_of_loop)
2966 #undef NOMMU_HACK_FMT
2967 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
2968 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2971 for (cur = G.top_var; cur; cur = cur->next) {
2972 if (!cur->flg_export || cur->flg_read_only)
2975 # if ENABLE_HUSH_FUNCTIONS
2976 for (funcp = G.top_func; funcp; funcp = funcp->next)
2982 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2983 *pp++ = (char *) G.argv0_for_re_execing;
2985 for (cur = G.top_var; cur; cur = cur->next) {
2986 if (cur->varstr == hush_version_str)
2988 if (cur->flg_read_only) {
2989 *pp++ = (char *) "-R";
2990 *pp++ = cur->varstr;
2991 } else if (!cur->flg_export) {
2992 *pp++ = (char *) "-V";
2993 *pp++ = cur->varstr;
2996 # if ENABLE_HUSH_FUNCTIONS
2997 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2998 *pp++ = (char *) "-F";
2999 *pp++ = funcp->name;
3000 *pp++ = funcp->body_as_string;
3003 /* We can pass activated traps here. Say, -Tnn:trap_string
3005 * However, POSIX says that subshells reset signals with traps
3007 * I tested bash-3.2 and it not only does that with true subshells
3008 * of the form ( list ), but with any forked children shells.
3009 * I set trap "echo W" WINCH; and then tried:
3011 * { echo 1; sleep 20; echo 2; } &
3012 * while true; do echo 1; sleep 20; echo 2; break; done &
3013 * true | { echo 1; sleep 20; echo 2; } | cat
3015 * In all these cases sending SIGWINCH to the child shell
3016 * did not run the trap. If I add trap "echo V" WINCH;
3017 * _inside_ group (just before echo 1), it works.
3019 * I conclude it means we don't need to pass active traps here.
3020 * Even if we would use signal handlers instead of signal masking
3021 * in order to implement trap handling,
3022 * exec syscall below resets signals to SIG_DFL for us.
3024 *pp++ = (char *) "-c";
3027 while (*++builtin_argv)
3028 *pp++ = *builtin_argv;
3029 *pp++ = (char *) "";
3034 /* *pp = NULL; - is already there */
3038 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3039 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3040 execve(bb_busybox_exec_path, argv, pp);
3041 /* Fallback. Useful for init=/bin/hush usage etc */
3042 if (argv[0][0] == '/')
3043 execve(argv[0], argv, pp);
3044 xfunc_error_retval = 127;
3045 bb_error_msg_and_die("can't re-execute the shell");
3047 #endif /* !BB_MMU */
3050 static void setup_heredoc(struct redir_struct *redir)
3052 struct fd_pair pair;
3055 /* the _body_ of heredoc (misleading field name) */
3056 const char *heredoc = redir->rd_filename;
3063 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3064 expanded = expand_pseudo_dquoted(heredoc);
3068 len = strlen(heredoc);
3070 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3072 xmove_fd(pair.rd, redir->rd_fd);
3074 /* Try writing without forking. Newer kernels have
3075 * dynamically growing pipes. Must use non-blocking write! */
3078 written = write(pair.wr, heredoc, len);
3089 ndelay_off(pair.wr);
3091 /* Okay, pipe buffer was not big enough */
3092 /* Note: we must not create a stray child (bastard? :)
3093 * for the unsuspecting parent process. Child creates a grandchild
3094 * and exits before parent execs the process which consumes heredoc
3095 * (that exec happens after we return from this function) */
3101 bb_perror_msg_and_die("vfork");
3104 disable_restore_tty_pgrp_on_exit();
3105 pid = BB_MMU ? fork() : vfork();
3107 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3111 close(redir->rd_fd); /* read side of the pipe */
3113 full_write(pair.wr, heredoc, len); /* may loop or block */
3116 /* Delegate blocking writes to another process */
3117 xmove_fd(pair.wr, STDOUT_FILENO);
3118 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3122 #if ENABLE_HUSH_FAST
3124 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3126 enable_restore_tty_pgrp_on_exit();
3132 wait(NULL); /* wait till child has died */
3135 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3136 * and stderr if they are redirected. */
3137 static int setup_redirects(struct command *prog, int squirrel[])
3140 struct redir_struct *redir;
3142 for (redir = prog->redirects; redir; redir = redir->next) {
3143 if (redir->rd_type == REDIRECT_HEREDOC2) {
3144 /* rd_fd<<HERE case */
3145 if (squirrel && redir->rd_fd < 3
3146 && squirrel[redir->rd_fd] < 0
3148 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3150 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3152 debug_printf_parse("set heredoc '%s'\n",
3153 redir->rd_filename);
3154 setup_heredoc(redir);
3158 if (redir->rd_dup == REDIRFD_TO_FILE) {
3159 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3161 if (redir->rd_filename == NULL) {
3162 /* Something went wrong in the parse.
3163 * Pretend it didn't happen */
3164 bb_error_msg("bug in redirect parse");
3167 mode = redir_table[redir->rd_type].mode;
3168 p = expand_string_to_string(redir->rd_filename);
3169 openfd = open_or_warn(p, mode);
3172 /* this could get lost if stderr has been redirected, but
3173 * bash and ash both lose it as well (though zsh doesn't!) */
3174 //what the above comment tries to say?
3178 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3179 openfd = redir->rd_dup;
3182 if (openfd != redir->rd_fd) {
3183 if (squirrel && redir->rd_fd < 3
3184 && squirrel[redir->rd_fd] < 0
3186 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3188 if (openfd == REDIRFD_CLOSE) {
3189 /* "n>-" means "close me" */
3190 close(redir->rd_fd);
3192 xdup2(openfd, redir->rd_fd);
3193 if (redir->rd_dup == REDIRFD_TO_FILE)
3201 static void restore_redirects(int squirrel[])
3204 for (i = 0; i < 3; i++) {
3207 /* We simply die on error */
3214 static void free_pipe_list(struct pipe *head);
3216 /* Return code is the exit status of the pipe */
3217 static void free_pipe(struct pipe *pi)
3220 struct command *command;
3221 struct redir_struct *r, *rnext;
3224 if (pi->stopped_cmds > 0) /* why? */
3226 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3227 for (i = 0; i < pi->num_cmds; i++) {
3228 command = &pi->cmds[i];
3229 debug_printf_clean(" command %d:\n", i);
3230 if (command->argv) {
3231 for (a = 0, p = command->argv; *p; a++, p++) {
3232 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3234 free_strings(command->argv);
3235 command->argv = NULL;
3237 /* not "else if": on syntax error, we may have both! */
3238 if (command->group) {
3239 debug_printf_clean(" begin group (cmd_type:%d)\n",
3241 free_pipe_list(command->group);
3242 debug_printf_clean(" end group\n");
3243 command->group = NULL;
3245 /* else is crucial here.
3246 * If group != NULL, child_func is meaningless */
3247 #if ENABLE_HUSH_FUNCTIONS
3248 else if (command->child_func) {
3249 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3250 command->child_func->parent_cmd = NULL;
3254 free(command->group_as_string);
3255 command->group_as_string = NULL;
3257 for (r = command->redirects; r; r = rnext) {
3258 debug_printf_clean(" redirect %d%s",
3259 r->rd_fd, redir_table[r->rd_type].descrip);
3260 /* guard against the case >$FOO, where foo is unset or blank */
3261 if (r->rd_filename) {
3262 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3263 free(r->rd_filename);
3264 r->rd_filename = NULL;
3266 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3270 command->redirects = NULL;
3272 free(pi->cmds); /* children are an array, they get freed all at once */
3280 static void free_pipe_list(struct pipe *head)
3282 struct pipe *pi, *next;
3284 for (pi = head; pi; pi = next) {
3286 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3289 debug_printf_clean("pipe followup code %d\n", pi->followup);
3291 /*pi->next = NULL;*/
3297 static int run_list(struct pipe *pi);
3299 #define parse_stream(pstring, input, end_trigger) \
3300 parse_stream(input, end_trigger)
3302 static struct pipe *parse_stream(char **pstring,
3303 struct in_str *input,
3305 static void parse_and_run_string(const char *s);
3308 static char *find_in_path(const char *arg)
3311 const char *PATH = get_local_var_value("PATH");
3317 const char *end = strchrnul(PATH, ':');
3318 int sz = end - PATH; /* must be int! */
3322 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3324 /* We have xxx::yyyy in $PATH,
3325 * it means "use current dir" */
3328 if (access(ret, F_OK) == 0)
3341 static const struct built_in_command* find_builtin_helper(const char *name,
3342 const struct built_in_command *x,
3343 const struct built_in_command *end)
3346 if (strcmp(name, x->b_cmd) != 0) {
3350 debug_printf_exec("found builtin '%s'\n", name);
3355 static const struct built_in_command* find_builtin1(const char *name)
3357 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3359 static const struct built_in_command* find_builtin(const char *name)
3361 const struct built_in_command *x = find_builtin1(name);
3364 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3367 #if ENABLE_HUSH_FUNCTIONS
3368 static struct function **find_function_slot(const char *name)
3370 struct function **funcpp = &G.top_func;
3372 if (strcmp(name, (*funcpp)->name) == 0) {
3375 funcpp = &(*funcpp)->next;
3380 static const struct function *find_function(const char *name)
3382 const struct function *funcp = *find_function_slot(name);
3384 debug_printf_exec("found function '%s'\n", name);
3388 /* Note: takes ownership on name ptr */
3389 static struct function *new_function(char *name)
3391 struct function **funcpp = find_function_slot(name);
3392 struct function *funcp = *funcpp;
3394 if (funcp != NULL) {
3395 struct command *cmd = funcp->parent_cmd;
3396 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3398 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3400 /* Note: if !funcp->body, do not free body_as_string!
3401 * This is a special case of "-F name body" function:
3402 * body_as_string was not malloced! */
3404 free_pipe_list(funcp->body);
3406 free(funcp->body_as_string);
3410 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3411 cmd->argv[0] = funcp->name;
3412 cmd->group = funcp->body;
3414 cmd->group_as_string = funcp->body_as_string;
3418 debug_printf_exec("remembering new function '%s'\n", name);
3419 funcp = *funcpp = xzalloc(sizeof(*funcp));
3420 /*funcp->next = NULL;*/
3427 static void unset_func(const char *name)
3429 struct function **funcpp = find_function_slot(name);
3430 struct function *funcp = *funcpp;
3432 if (funcp != NULL) {
3433 debug_printf_exec("freeing function '%s'\n", funcp->name);
3434 *funcpp = funcp->next;
3435 /* funcp is unlinked now, deleting it.
3436 * Note: if !funcp->body, the function was created by
3437 * "-F name body", do not free ->body_as_string
3438 * and ->name as they were not malloced. */
3440 free_pipe_list(funcp->body);
3443 free(funcp->body_as_string);
3451 #define exec_function(to_free, funcp, argv) \
3452 exec_function(funcp, argv)
3454 static void exec_function(char ***to_free,
3455 const struct function *funcp,
3456 char **argv) NORETURN;
3457 static void exec_function(char ***to_free,
3458 const struct function *funcp,
3464 argv[0] = G.global_argv[0];
3465 G.global_argv = argv;
3469 /* On MMU, funcp->body is always non-NULL */
3470 n = run_list(funcp->body);
3474 re_execute_shell(to_free,
3475 funcp->body_as_string,
3482 static int run_function(const struct function *funcp, char **argv)
3488 save_and_replace_G_args(&sv, argv);
3490 /* "we are in function, ok to use return" */
3491 sv_flg = G.flag_return_in_progress;
3492 G.flag_return_in_progress = -1;
3493 # if ENABLE_HUSH_LOCAL
3494 G.func_nest_level++;
3497 /* On MMU, funcp->body is always non-NULL */
3500 /* Function defined by -F */
3501 parse_and_run_string(funcp->body_as_string);
3502 rc = G.last_exitcode;
3506 rc = run_list(funcp->body);
3509 # if ENABLE_HUSH_LOCAL
3511 struct variable *var;
3512 struct variable **var_pp;
3514 var_pp = &G.top_var;
3515 while ((var = *var_pp) != NULL) {
3516 if (var->func_nest_level < G.func_nest_level) {
3517 var_pp = &var->next;
3521 if (var->flg_export)
3522 bb_unsetenv(var->varstr);
3523 /* Remove from global list */
3524 *var_pp = var->next;
3530 G.func_nest_level--;
3533 G.flag_return_in_progress = sv_flg;
3535 restore_G_args(&sv, argv);
3539 #endif /* ENABLE_HUSH_FUNCTIONS */
3543 #define exec_builtin(to_free, x, argv) \
3544 exec_builtin(x, argv)
3546 #define exec_builtin(to_free, x, argv) \
3547 exec_builtin(to_free, argv)
3549 static void exec_builtin(char ***to_free,
3550 const struct built_in_command *x,
3551 char **argv) NORETURN;
3552 static void exec_builtin(char ***to_free,
3553 const struct built_in_command *x,
3557 int rcode = x->b_function(argv);
3561 /* On NOMMU, we must never block!
3562 * Example: { sleep 99 | read line; } & echo Ok
3564 re_execute_shell(to_free,
3573 static void execvp_or_die(char **argv) NORETURN;
3574 static void execvp_or_die(char **argv)
3576 debug_printf_exec("execing '%s'\n", argv[0]);
3577 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3578 execvp(argv[0], argv);
3579 bb_perror_msg("can't execute '%s'", argv[0]);
3580 _exit(127); /* bash compat */
3584 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3585 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3586 #define pseudo_exec(nommu_save, command, argv_expanded) \
3587 pseudo_exec(command, argv_expanded)
3590 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3592 * Don't exit() here. If you don't exec, use _exit instead.
3593 * The at_exit handlers apparently confuse the calling process,
3594 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3595 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3596 char **argv, int assignment_cnt,
3597 char **argv_expanded) NORETURN;
3598 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3599 char **argv, int assignment_cnt,
3600 char **argv_expanded)
3604 /* Case when we are here: ... | var=val | ... */
3605 if (!argv[assignment_cnt])
3606 _exit(EXIT_SUCCESS);
3608 new_env = expand_assignments(argv, assignment_cnt);
3610 set_vars_and_save_old(new_env);
3611 free(new_env); /* optional */
3612 /* we can also destroy set_vars_and_save_old's return value,
3615 nommu_save->new_env = new_env;
3616 nommu_save->old_vars = set_vars_and_save_old(new_env);
3618 if (argv_expanded) {
3619 argv = argv_expanded;
3621 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3623 nommu_save->argv = argv;
3627 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3628 if (strchr(argv[0], '/') != NULL)
3632 /* Check if the command matches any of the builtins.
3633 * Depending on context, this might be redundant. But it's
3634 * easier to waste a few CPU cycles than it is to figure out
3635 * if this is one of those cases.
3638 /* On NOMMU, it is more expensive to re-execute shell
3639 * just in order to run echo or test builtin.
3640 * It's better to skip it here and run corresponding
3641 * non-builtin later. */
3642 const struct built_in_command *x;
3643 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3645 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3648 #if ENABLE_HUSH_FUNCTIONS
3649 /* Check if the command matches any functions */
3651 const struct function *funcp = find_function(argv[0]);
3653 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3658 #if ENABLE_FEATURE_SH_STANDALONE
3659 /* Check if the command matches any busybox applets */
3661 int a = find_applet_by_name(argv[0]);
3663 # if BB_MMU /* see above why on NOMMU it is not allowed */
3664 if (APPLET_IS_NOEXEC(a)) {
3665 debug_printf_exec("running applet '%s'\n", argv[0]);
3666 run_applet_no_and_exit(a, argv);
3669 /* Re-exec ourselves */
3670 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3671 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3672 execv(bb_busybox_exec_path, argv);
3673 /* If they called chroot or otherwise made the binary no longer
3674 * executable, fall through */
3679 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3682 execvp_or_die(argv);
3685 /* Called after [v]fork() in run_pipe
3687 static void pseudo_exec(nommu_save_t *nommu_save,
3688 struct command *command,
3689 char **argv_expanded) NORETURN;
3690 static void pseudo_exec(nommu_save_t *nommu_save,
3691 struct command *command,
3692 char **argv_expanded)
3694 if (command->argv) {
3695 pseudo_exec_argv(nommu_save, command->argv,
3696 command->assignment_cnt, argv_expanded);
3699 if (command->group) {
3700 /* Cases when we are here:
3703 * ... | ( list ) | ...
3704 * ... | { list } | ...
3708 debug_printf_exec("pseudo_exec: run_list\n");
3709 reset_traps_to_defaults();
3710 rcode = run_list(command->group);
3711 /* OK to leak memory by not calling free_pipe_list,
3712 * since this process is about to exit */
3715 re_execute_shell(&nommu_save->argv_from_re_execing,
3716 command->group_as_string,
3723 /* Case when we are here: ... | >file */
3724 debug_printf_exec("pseudo_exec'ed null command\n");
3725 _exit(EXIT_SUCCESS);
3729 static const char *get_cmdtext(struct pipe *pi)
3735 /* This is subtle. ->cmdtext is created only on first backgrounding.
3736 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3737 * On subsequent bg argv is trashed, but we won't use it */
3740 argv = pi->cmds[0].argv;
3741 if (!argv || !argv[0]) {
3742 pi->cmdtext = xzalloc(1);
3748 len += strlen(*argv) + 1;
3752 argv = pi->cmds[0].argv;
3754 len = strlen(*argv);
3755 memcpy(p, *argv, len);
3763 static void insert_bg_job(struct pipe *pi)
3765 struct pipe *job, **jobp;
3768 /* Linear search for the ID of the job to use */
3770 for (job = G.job_list; job; job = job->next)
3771 if (job->jobid >= pi->jobid)
3772 pi->jobid = job->jobid + 1;
3774 /* Add job to the list of running jobs */
3776 while ((job = *jobp) != NULL)
3778 job = *jobp = xmalloc(sizeof(*job));
3780 *job = *pi; /* physical copy */
3782 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3783 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3784 for (i = 0; i < pi->num_cmds; i++) {
3785 job->cmds[i].pid = pi->cmds[i].pid;
3786 /* all other fields are not used and stay zero */
3788 job->cmdtext = xstrdup(get_cmdtext(pi));
3790 if (G_interactive_fd)
3791 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3792 /* Last command's pid goes to $! */
3793 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3794 G.last_jobid = job->jobid;
3797 static void remove_bg_job(struct pipe *pi)
3799 struct pipe *prev_pipe;
3801 if (pi == G.job_list) {
3802 G.job_list = pi->next;
3804 prev_pipe = G.job_list;
3805 while (prev_pipe->next != pi)
3806 prev_pipe = prev_pipe->next;
3807 prev_pipe->next = pi->next;
3810 G.last_jobid = G.job_list->jobid;
3815 /* Remove a backgrounded job */
3816 static void delete_finished_bg_job(struct pipe *pi)
3819 pi->stopped_cmds = 0;
3825 /* Check to see if any processes have exited -- if they
3826 * have, figure out why and see if a job has completed */
3827 static int checkjobs(struct pipe* fg_pipe)
3837 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3839 attributes = WUNTRACED;
3840 if (fg_pipe == NULL)
3841 attributes |= WNOHANG;
3844 #if ENABLE_HUSH_FAST
3845 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3846 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3847 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3848 /* There was neither fork nor SIGCHLD since last waitpid */
3849 /* Avoid doing waitpid syscall if possible */
3850 if (!G.we_have_children) {
3854 if (fg_pipe == NULL) { /* is WNOHANG set? */
3855 /* We have children, but they did not exit
3856 * or stop yet (we saw no SIGCHLD) */
3859 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3863 /* Do we do this right?
3864 * bash-3.00# sleep 20 | false
3866 * [3]+ Stopped sleep 20 | false
3867 * bash-3.00# echo $?
3868 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3869 * [hush 1.14.0: yes we do it right]
3876 #if ENABLE_HUSH_FAST
3877 i = G.count_SIGCHLD;
3879 childpid = waitpid(-1, &status, attributes);
3880 if (childpid <= 0) {
3881 if (childpid && errno != ECHILD)
3882 bb_perror_msg("waitpid");
3883 #if ENABLE_HUSH_FAST
3884 else { /* Until next SIGCHLD, waitpid's are useless */
3885 G.we_have_children = (childpid == 0);
3886 G.handled_SIGCHLD = i;
3887 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3892 dead = WIFEXITED(status) || WIFSIGNALED(status);
3895 if (WIFSTOPPED(status))
3896 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3897 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3898 if (WIFSIGNALED(status))
3899 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3900 childpid, WTERMSIG(status), WEXITSTATUS(status));
3901 if (WIFEXITED(status))
3902 debug_printf_jobs("pid %d exited, exitcode %d\n",
3903 childpid, WEXITSTATUS(status));
3905 /* Were we asked to wait for fg pipe? */
3907 for (i = 0; i < fg_pipe->num_cmds; i++) {
3908 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3909 if (fg_pipe->cmds[i].pid != childpid)
3912 fg_pipe->cmds[i].pid = 0;
3913 fg_pipe->alive_cmds--;
3914 if (i == fg_pipe->num_cmds - 1) {
3915 /* last process gives overall exitstatus */
3916 rcode = WEXITSTATUS(status);
3917 /* bash prints killer signal's name for *last*
3918 * process in pipe (prints just newline for SIGINT).
3919 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3921 if (WIFSIGNALED(status)) {
3922 int sig = WTERMSIG(status);
3923 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3924 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
3925 * Maybe we need to use sig | 128? */
3928 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3931 fg_pipe->cmds[i].is_stopped = 1;
3932 fg_pipe->stopped_cmds++;
3934 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3935 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3936 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3937 /* All processes in fg pipe have exited or stopped */
3938 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3939 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3940 * and "killall -STOP cat" */
3941 if (G_interactive_fd) {
3943 if (fg_pipe->alive_cmds)
3944 insert_bg_job(fg_pipe);
3948 if (!fg_pipe->alive_cmds)
3951 /* There are still running processes in the fg pipe */
3952 goto wait_more; /* do waitpid again */
3954 /* it wasnt fg_pipe, look for process in bg pipes */
3958 /* We asked to wait for bg or orphaned children */
3959 /* No need to remember exitcode in this case */
3960 for (pi = G.job_list; pi; pi = pi->next) {
3961 for (i = 0; i < pi->num_cmds; i++) {
3962 if (pi->cmds[i].pid == childpid)
3963 goto found_pi_and_prognum;
3966 /* Happens when shell is used as init process (init=/bin/sh) */
3967 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3968 continue; /* do waitpid again */
3970 found_pi_and_prognum:
3973 pi->cmds[i].pid = 0;
3975 if (!pi->alive_cmds) {
3976 if (G_interactive_fd)
3977 printf(JOB_STATUS_FORMAT, pi->jobid,
3978 "Done", pi->cmdtext);
3979 delete_finished_bg_job(pi);
3983 pi->cmds[i].is_stopped = 1;
3987 } /* while (waitpid succeeds)... */
3993 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3996 int rcode = checkjobs(fg_pipe);
3997 if (G_saved_tty_pgrp) {
3998 /* Job finished, move the shell to the foreground */
3999 p = getpgrp(); /* our process group id */
4000 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4001 tcsetpgrp(G_interactive_fd, p);
4007 /* Start all the jobs, but don't wait for anything to finish.
4010 * Return code is normally -1, when the caller has to wait for children
4011 * to finish to determine the exit status of the pipe. If the pipe
4012 * is a simple builtin command, however, the action is done by the
4013 * time run_pipe returns, and the exit code is provided as the
4016 * Returns -1 only if started some children. IOW: we have to
4017 * mask out retvals of builtins etc with 0xff!
4019 * The only case when we do not need to [v]fork is when the pipe
4020 * is single, non-backgrounded, non-subshell command. Examples:
4021 * cmd ; ... { list } ; ...
4022 * cmd && ... { list } && ...
4023 * cmd || ... { list } || ...
4024 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4025 * or (if SH_STANDALONE) an applet, and we can run the { list }
4026 * with run_list. If it isn't one of these, we fork and exec cmd.
4028 * Cases when we must fork:
4029 * non-single: cmd | cmd
4030 * backgrounded: cmd & { list } &
4031 * subshell: ( list ) [&]
4033 static NOINLINE int run_pipe(struct pipe *pi)
4035 static const char *const null_ptr = NULL;
4038 struct command *command;
4039 char **argv_expanded;
4042 /* it is not always needed, but we aim to smaller code */
4043 int squirrel[] = { -1, -1, -1 };
4046 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4049 IF_HUSH_JOB(pi->pgrp = -1;)
4050 pi->stopped_cmds = 0;
4051 command = &(pi->cmds[0]);
4052 argv_expanded = NULL;
4054 if (pi->num_cmds != 1
4055 || pi->followup == PIPE_BG
4056 || command->cmd_type == CMD_SUBSHELL
4063 debug_printf_exec(": group:%p argv:'%s'\n",
4064 command->group, command->argv ? command->argv[0] : "NONE");
4066 if (command->group) {
4067 #if ENABLE_HUSH_FUNCTIONS
4068 if (command->cmd_type == CMD_FUNCDEF) {
4069 /* "executing" func () { list } */
4070 struct function *funcp;
4072 funcp = new_function(command->argv[0]);
4073 /* funcp->name is already set to argv[0] */
4074 funcp->body = command->group;
4076 funcp->body_as_string = command->group_as_string;
4077 command->group_as_string = NULL;
4079 command->group = NULL;
4080 command->argv[0] = NULL;
4081 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4082 funcp->parent_cmd = command;
4083 command->child_func = funcp;
4085 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4087 return EXIT_SUCCESS;
4091 debug_printf("non-subshell group\n");
4092 rcode = 1; /* exitcode if redir failed */
4093 if (setup_redirects(command, squirrel) == 0) {
4094 debug_printf_exec(": run_list\n");
4095 rcode = run_list(command->group) & 0xff;
4097 restore_redirects(squirrel);
4098 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4100 debug_printf_exec("run_pipe: return %d\n", rcode);
4104 argv = command->argv ? command->argv : (char **) &null_ptr;
4106 const struct built_in_command *x;
4107 #if ENABLE_HUSH_FUNCTIONS
4108 const struct function *funcp;
4112 char **new_env = NULL;
4113 struct variable *old_vars = NULL;
4115 if (argv[command->assignment_cnt] == NULL) {
4116 /* Assignments, but no command */
4117 /* Ensure redirects take effect. Try "a=t >file" */
4118 rcode = setup_redirects(command, squirrel);
4119 //FIXME: "false; q=`false`; echo $?" should print 1
4120 restore_redirects(squirrel);
4121 /* Set shell variables */
4123 p = expand_string_to_string(*argv);
4124 debug_printf_exec("set shell var:'%s'->'%s'\n",
4126 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4129 /* Do we need to flag set_local_var() errors?
4130 * "assignment to readonly var" and "putenv error"
4132 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4134 debug_printf_exec("run_pipe: return %d\n", rcode);
4138 /* Expand the rest into (possibly) many strings each */
4140 #if ENABLE_HUSH_BASH_COMPAT
4141 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4142 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4145 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4146 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4147 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4152 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4155 /* if someone gives us an empty string: `cmd with empty output` */
4156 if (!argv_expanded[0]) {
4157 free(argv_expanded);
4159 return G.last_exitcode;
4162 x = find_builtin(argv_expanded[0]);
4163 #if ENABLE_HUSH_FUNCTIONS
4166 funcp = find_function(argv_expanded[0]);
4170 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4171 debug_printf("exec with redirects only\n");
4172 rcode = setup_redirects(command, NULL);
4173 goto clean_up_and_ret1;
4176 /* setup_redirects acts on file descriptors, not FILEs.
4177 * This is perfect for work that comes after exec().
4178 * Is it really safe for inline use? Experimentally,
4179 * things seem to work. */
4180 rcode = setup_redirects(command, squirrel);
4182 new_env = expand_assignments(argv, command->assignment_cnt);
4183 old_vars = set_vars_and_save_old(new_env);
4185 debug_printf_exec(": builtin '%s' '%s'...\n",
4186 x->cmd, argv_expanded[1]);
4187 rcode = x->b_function(argv_expanded) & 0xff;
4190 #if ENABLE_HUSH_FUNCTIONS
4192 # if ENABLE_HUSH_LOCAL
4193 struct variable **sv;
4194 sv = G.shadowed_vars_pp;
4195 G.shadowed_vars_pp = &old_vars;
4197 debug_printf_exec(": function '%s' '%s'...\n",
4198 funcp->name, argv_expanded[1]);
4199 rcode = run_function(funcp, argv_expanded) & 0xff;
4200 # if ENABLE_HUSH_LOCAL
4201 G.shadowed_vars_pp = sv;
4206 #if ENABLE_FEATURE_SH_STANDALONE
4209 restore_redirects(squirrel);
4210 unset_vars(new_env);
4213 free(argv_expanded);
4214 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4216 debug_printf_exec("run_pipe return %d\n", rcode);
4220 #if ENABLE_FEATURE_SH_STANDALONE
4221 i = find_applet_by_name(argv_expanded[0]);
4222 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4223 rcode = setup_redirects(command, squirrel);
4225 new_env = expand_assignments(argv, command->assignment_cnt);
4226 old_vars = set_vars_and_save_old(new_env);
4227 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4228 argv_expanded[0], argv_expanded[1]);
4229 rcode = run_nofork_applet(i, argv_expanded);
4231 goto clean_up_and_ret;
4234 /* It is neither builtin nor applet. We must fork. */
4238 /* NB: argv_expanded may already be created, and that
4239 * might include `cmd` runs! Do not rerun it! We *must*
4240 * use argv_expanded if it's non-NULL */
4242 /* Going to fork a child per each pipe member */
4246 for (i = 0; i < pi->num_cmds; i++) {
4247 struct fd_pair pipefds;
4249 volatile nommu_save_t nommu_save;
4250 nommu_save.new_env = NULL;
4251 nommu_save.old_vars = NULL;
4252 nommu_save.argv = NULL;
4253 nommu_save.argv_from_re_execing = NULL;
4255 command = &(pi->cmds[i]);
4256 if (command->argv) {
4257 debug_printf_exec(": pipe member '%s' '%s'...\n",
4258 command->argv[0], command->argv[1]);
4260 debug_printf_exec(": pipe member with no argv\n");
4263 /* pipes are inserted between pairs of commands */
4266 if ((i + 1) < pi->num_cmds)
4267 xpiped_pair(pipefds);
4269 command->pid = BB_MMU ? fork() : vfork();
4270 if (!command->pid) { /* child */
4272 disable_restore_tty_pgrp_on_exit();
4273 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4275 /* Every child adds itself to new process group
4276 * with pgid == pid_of_first_child_in_pipe */
4277 if (G.run_list_level == 1 && G_interactive_fd) {
4280 if (pgrp < 0) /* true for 1st process only */
4282 if (setpgid(0, pgrp) == 0
4283 && pi->followup != PIPE_BG
4284 && G_saved_tty_pgrp /* we have ctty */
4286 /* We do it in *every* child, not just first,
4288 tcsetpgrp(G_interactive_fd, pgrp);
4292 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4293 /* 1st cmd in backgrounded pipe
4294 * should have its stdin /dev/null'ed */
4296 if (open(bb_dev_null, O_RDONLY))
4297 xopen("/", O_RDONLY);
4299 xmove_fd(nextin, 0);
4301 xmove_fd(pipefds.wr, 1);
4304 /* Like bash, explicit redirects override pipes,
4305 * and the pipe fd is available for dup'ing. */
4306 if (setup_redirects(command, NULL))
4309 /* Restore default handlers just prior to exec */
4310 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4312 /* Stores to nommu_save list of env vars putenv'ed
4313 * (NOMMU, on MMU we don't need that) */
4314 /* cast away volatility... */
4315 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4316 /* pseudo_exec() does not return */
4319 /* parent or error */
4320 #if ENABLE_HUSH_FAST
4322 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4324 enable_restore_tty_pgrp_on_exit();
4326 /* Clean up after vforked child */
4327 free(nommu_save.argv);
4328 free(nommu_save.argv_from_re_execing);
4329 unset_vars(nommu_save.new_env);
4330 add_vars(nommu_save.old_vars);
4332 free(argv_expanded);
4333 argv_expanded = NULL;
4334 if (command->pid < 0) { /* [v]fork failed */
4335 /* Clearly indicate, was it fork or vfork */
4336 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4340 /* Second and next children need to know pid of first one */
4342 pi->pgrp = command->pid;
4348 if ((i + 1) < pi->num_cmds)
4350 /* Pass read (output) pipe end to next iteration */
4351 nextin = pipefds.rd;
4354 if (!pi->alive_cmds) {
4356 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4361 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4365 #ifndef debug_print_tree
4366 static void debug_print_tree(struct pipe *pi, int lvl)
4368 static const char *const PIPE[] = {
4374 static const char *RES[] = {
4375 [RES_NONE ] = "NONE" ,
4378 [RES_THEN ] = "THEN" ,
4379 [RES_ELIF ] = "ELIF" ,
4380 [RES_ELSE ] = "ELSE" ,
4383 # if ENABLE_HUSH_LOOPS
4384 [RES_FOR ] = "FOR" ,
4385 [RES_WHILE] = "WHILE",
4386 [RES_UNTIL] = "UNTIL",
4388 [RES_DONE ] = "DONE" ,
4390 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4393 # if ENABLE_HUSH_CASE
4394 [RES_CASE ] = "CASE" ,
4395 [RES_CASE_IN ] = "CASE_IN" ,
4396 [RES_MATCH] = "MATCH",
4397 [RES_CASE_BODY] = "CASE_BODY",
4398 [RES_ESAC ] = "ESAC" ,
4400 [RES_XXXX ] = "XXXX" ,
4401 [RES_SNTX ] = "SNTX" ,
4403 static const char *const CMDTYPE[] = {
4407 # if ENABLE_HUSH_FUNCTIONS
4416 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4417 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4419 while (prn < pi->num_cmds) {
4420 struct command *command = &pi->cmds[prn];
4421 char **argv = command->argv;
4423 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4425 command->assignment_cnt);
4426 if (command->group) {
4427 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4428 CMDTYPE[command->cmd_type],
4431 , " group_as_string:", command->group_as_string
4436 debug_print_tree(command->group, lvl+1);
4440 if (argv) while (*argv) {
4441 fprintf(stderr, " '%s'", *argv);
4444 fprintf(stderr, "\n");
4451 #endif /* debug_print_tree */
4453 /* NB: called by pseudo_exec, and therefore must not modify any
4454 * global data until exec/_exit (we can be a child after vfork!) */
4455 static int run_list(struct pipe *pi)
4457 #if ENABLE_HUSH_CASE
4458 char *case_word = NULL;
4460 #if ENABLE_HUSH_LOOPS
4461 struct pipe *loop_top = NULL;
4462 char **for_lcur = NULL;
4463 char **for_list = NULL;
4465 smallint last_followup;
4467 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4468 smalluint cond_code = 0;
4470 enum { cond_code = 0 };
4473 smallint rword; /* enum reserved_style */
4474 smallint last_rword; /* ditto */
4477 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4480 #if ENABLE_HUSH_LOOPS
4481 /* Check syntax for "for" */
4482 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4483 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4485 /* current word is FOR or IN (BOLD in comments below) */
4486 if (cpipe->next == NULL) {
4487 syntax_error("malformed for");
4489 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4492 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4493 if (cpipe->next->res_word == RES_DO)
4495 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4496 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4497 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4499 syntax_error("malformed for");
4501 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4507 /* Past this point, all code paths should jump to ret: label
4508 * in order to return, no direct "return" statements please.
4509 * This helps to ensure that no memory is leaked. */
4517 last_rword = RES_XXXX;
4519 last_followup = PIPE_SEQ;
4520 rcode = G.last_exitcode;
4522 /* Go through list of pipes, (maybe) executing them. */
4523 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4527 IF_HAS_KEYWORDS(rword = pi->res_word;)
4528 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4529 rword, cond_code, last_rword);
4530 #if ENABLE_HUSH_LOOPS
4531 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4532 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4534 /* start of a loop: remember where loop starts */
4539 /* Still in the same "if...", "then..." or "do..." branch? */
4540 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4541 if ((rcode == 0 && last_followup == PIPE_OR)
4542 || (rcode != 0 && last_followup == PIPE_AND)
4544 /* It is "<true> || CMD" or "<false> && CMD"
4545 * and we should not execute CMD */
4546 debug_printf_exec("skipped cmd because of || or &&\n");
4547 last_followup = pi->followup;
4551 last_followup = pi->followup;
4552 IF_HAS_KEYWORDS(last_rword = rword;)
4555 if (rword == RES_THEN) {
4556 /* if false; then ... fi has exitcode 0! */
4557 G.last_exitcode = rcode = EXIT_SUCCESS;
4558 /* "if <false> THEN cmd": skip cmd */
4562 if (rword == RES_ELSE || rword == RES_ELIF) {
4563 /* "if <true> then ... ELSE/ELIF cmd":
4564 * skip cmd and all following ones */
4569 #if ENABLE_HUSH_LOOPS
4570 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4572 /* first loop through for */
4574 static const char encoded_dollar_at[] ALIGN1 = {
4575 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4576 }; /* encoded representation of "$@" */
4577 static const char *const encoded_dollar_at_argv[] = {
4578 encoded_dollar_at, NULL
4579 }; /* argv list with one element: "$@" */
4582 vals = (char**)encoded_dollar_at_argv;
4583 if (pi->next->res_word == RES_IN) {
4584 /* if no variable values after "in" we skip "for" */
4585 if (!pi->next->cmds[0].argv) {
4586 G.last_exitcode = rcode = EXIT_SUCCESS;
4587 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4590 vals = pi->next->cmds[0].argv;
4591 } /* else: "for var; do..." -> assume "$@" list */
4592 /* create list of variable values */
4593 debug_print_strings("for_list made from", vals);
4594 for_list = expand_strvec_to_strvec(vals);
4595 for_lcur = for_list;
4596 debug_print_strings("for_list", for_list);
4599 /* "for" loop is over, clean up */
4605 /* Insert next value from for_lcur */
4606 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4607 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4610 if (rword == RES_IN) {
4611 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4613 if (rword == RES_DONE) {
4614 continue; /* "done" has no cmds too */
4617 #if ENABLE_HUSH_CASE
4618 if (rword == RES_CASE) {
4619 case_word = expand_strvec_to_string(pi->cmds->argv);
4622 if (rword == RES_MATCH) {
4625 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4627 /* all prev words didn't match, does this one match? */
4628 argv = pi->cmds->argv;
4630 char *pattern = expand_string_to_string(*argv);
4631 /* TODO: which FNM_xxx flags to use? */
4632 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4634 if (cond_code == 0) { /* match! we will execute this branch */
4635 free(case_word); /* make future "word)" stop */
4643 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4645 continue; /* not matched yet, skip this pipe */
4648 /* Just pressing <enter> in shell should check for jobs.
4649 * OTOH, in non-interactive shell this is useless
4650 * and only leads to extra job checks */
4651 if (pi->num_cmds == 0) {
4652 if (G_interactive_fd)
4653 goto check_jobs_and_continue;
4657 /* After analyzing all keywords and conditions, we decided
4658 * to execute this pipe. NB: have to do checkjobs(NULL)
4659 * after run_pipe to collect any background children,
4660 * even if list execution is to be stopped. */
4661 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4664 #if ENABLE_HUSH_LOOPS
4665 G.flag_break_continue = 0;
4667 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4669 /* We ran a builtin, function, or group.
4670 * rcode is already known
4671 * and we don't need to wait for anything. */
4672 G.last_exitcode = rcode;
4673 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4674 check_and_run_traps(0);
4675 #if ENABLE_HUSH_LOOPS
4676 /* Was it "break" or "continue"? */
4677 if (G.flag_break_continue) {
4678 smallint fbc = G.flag_break_continue;
4679 /* We might fall into outer *loop*,
4680 * don't want to break it too */
4682 G.depth_break_continue--;
4683 if (G.depth_break_continue == 0)
4684 G.flag_break_continue = 0;
4685 /* else: e.g. "continue 2" should *break* once, *then* continue */
4686 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4687 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4688 goto check_jobs_and_break;
4689 /* "continue": simulate end of loop */
4694 #if ENABLE_HUSH_FUNCTIONS
4695 if (G.flag_return_in_progress == 1) {
4696 /* same as "goto check_jobs_and_break" */
4701 } else if (pi->followup == PIPE_BG) {
4702 /* What does bash do with attempts to background builtins? */
4703 /* even bash 3.2 doesn't do that well with nested bg:
4704 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4705 * I'm NOT treating inner &'s as jobs */
4706 check_and_run_traps(0);
4708 if (G.run_list_level == 1)
4711 G.last_exitcode = rcode = EXIT_SUCCESS;
4712 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4715 if (G.run_list_level == 1 && G_interactive_fd) {
4716 /* Waits for completion, then fg's main shell */
4717 rcode = checkjobs_and_fg_shell(pi);
4718 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4719 check_and_run_traps(0);
4722 { /* This one just waits for completion */
4723 rcode = checkjobs(pi);
4724 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4725 check_and_run_traps(0);
4727 G.last_exitcode = rcode;
4731 /* Analyze how result affects subsequent commands */
4733 if (rword == RES_IF || rword == RES_ELIF)
4736 #if ENABLE_HUSH_LOOPS
4737 /* Beware of "while false; true; do ..."! */
4738 if (pi->next && pi->next->res_word == RES_DO) {
4739 if (rword == RES_WHILE) {
4741 /* "while false; do...done" - exitcode 0 */
4742 G.last_exitcode = rcode = EXIT_SUCCESS;
4743 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4744 goto check_jobs_and_break;
4747 if (rword == RES_UNTIL) {
4749 debug_printf_exec(": until expr is true: breaking\n");
4750 check_jobs_and_break:
4758 check_jobs_and_continue:
4765 #if ENABLE_HUSH_LOOPS
4770 #if ENABLE_HUSH_CASE
4774 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4778 /* Select which version we will use */
4779 static int run_and_free_list(struct pipe *pi)
4782 debug_printf_exec("run_and_free_list entered\n");
4784 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4785 rcode = run_list(pi);
4787 /* free_pipe_list has the side effect of clearing memory.
4788 * In the long run that function can be merged with run_list,
4789 * but doing that now would hobble the debugging effort. */
4791 debug_printf_exec("run_and_free_list return %d\n", rcode);
4796 static struct pipe *new_pipe(void)
4799 pi = xzalloc(sizeof(struct pipe));
4800 /*pi->followup = 0; - deliberately invalid value */
4801 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4805 /* Command (member of a pipe) is complete, or we start a new pipe
4806 * if ctx->command is NULL.
4807 * No errors possible here.
4809 static int done_command(struct parse_context *ctx)
4811 /* The command is really already in the pipe structure, so
4812 * advance the pipe counter and make a new, null command. */
4813 struct pipe *pi = ctx->pipe;
4814 struct command *command = ctx->command;
4817 if (IS_NULL_CMD(command)) {
4818 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4822 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4823 //debug_print_tree(ctx->list_head, 20);
4825 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4828 /* Only real trickiness here is that the uncommitted
4829 * command structure is not counted in pi->num_cmds. */
4830 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4831 ctx->command = command = &pi->cmds[pi->num_cmds];
4833 memset(command, 0, sizeof(*command));
4834 return pi->num_cmds; /* used only for 0/nonzero check */
4837 static void done_pipe(struct parse_context *ctx, pipe_style type)
4841 debug_printf_parse("done_pipe entered, followup %d\n", type);
4842 /* Close previous command */
4843 not_null = done_command(ctx);
4844 ctx->pipe->followup = type;
4846 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4847 ctx->ctx_inverted = 0;
4848 ctx->pipe->res_word = ctx->ctx_res_w;
4851 /* Without this check, even just <enter> on command line generates
4852 * tree of three NOPs (!). Which is harmless but annoying.
4853 * IOW: it is safe to do it unconditionally. */
4856 || ctx->ctx_res_w == RES_FI
4858 #if ENABLE_HUSH_LOOPS
4859 || ctx->ctx_res_w == RES_DONE
4860 || ctx->ctx_res_w == RES_FOR
4861 || ctx->ctx_res_w == RES_IN
4863 #if ENABLE_HUSH_CASE
4864 || ctx->ctx_res_w == RES_ESAC
4868 debug_printf_parse("done_pipe: adding new pipe: "
4869 "not_null:%d ctx->ctx_res_w:%d\n",
4870 not_null, ctx->ctx_res_w);
4872 ctx->pipe->next = new_p;
4874 /* RES_THEN, RES_DO etc are "sticky" -
4875 * they remain set for pipes inside if/while.
4876 * This is used to control execution.
4877 * RES_FOR and RES_IN are NOT sticky (needed to support
4878 * cases where variable or value happens to match a keyword):
4880 #if ENABLE_HUSH_LOOPS
4881 if (ctx->ctx_res_w == RES_FOR
4882 || ctx->ctx_res_w == RES_IN)
4883 ctx->ctx_res_w = RES_NONE;
4885 #if ENABLE_HUSH_CASE
4886 if (ctx->ctx_res_w == RES_MATCH)
4887 ctx->ctx_res_w = RES_CASE_BODY;
4888 if (ctx->ctx_res_w == RES_CASE)
4889 ctx->ctx_res_w = RES_CASE_IN;
4891 ctx->command = NULL; /* trick done_command below */
4892 /* Create the memory for command, roughly:
4893 * ctx->pipe->cmds = new struct command;
4894 * ctx->command = &ctx->pipe->cmds[0];
4897 //debug_print_tree(ctx->list_head, 10);
4899 debug_printf_parse("done_pipe return\n");
4902 static void initialize_context(struct parse_context *ctx)
4904 memset(ctx, 0, sizeof(*ctx));
4905 ctx->pipe = ctx->list_head = new_pipe();
4906 /* Create the memory for command, roughly:
4907 * ctx->pipe->cmds = new struct command;
4908 * ctx->command = &ctx->pipe->cmds[0];
4913 /* If a reserved word is found and processed, parse context is modified
4914 * and 1 is returned.
4917 struct reserved_combo {
4920 unsigned char assignment_flag;
4924 FLAG_END = (1 << RES_NONE ),
4926 FLAG_IF = (1 << RES_IF ),
4927 FLAG_THEN = (1 << RES_THEN ),
4928 FLAG_ELIF = (1 << RES_ELIF ),
4929 FLAG_ELSE = (1 << RES_ELSE ),
4930 FLAG_FI = (1 << RES_FI ),
4932 # if ENABLE_HUSH_LOOPS
4933 FLAG_FOR = (1 << RES_FOR ),
4934 FLAG_WHILE = (1 << RES_WHILE),
4935 FLAG_UNTIL = (1 << RES_UNTIL),
4936 FLAG_DO = (1 << RES_DO ),
4937 FLAG_DONE = (1 << RES_DONE ),
4938 FLAG_IN = (1 << RES_IN ),
4940 # if ENABLE_HUSH_CASE
4941 FLAG_MATCH = (1 << RES_MATCH),
4942 FLAG_ESAC = (1 << RES_ESAC ),
4944 FLAG_START = (1 << RES_XXXX ),
4947 static const struct reserved_combo* match_reserved_word(o_string *word)
4949 /* Mostly a list of accepted follow-up reserved words.
4950 * FLAG_END means we are done with the sequence, and are ready
4951 * to turn the compound list into a command.
4952 * FLAG_START means the word must start a new compound list.
4954 static const struct reserved_combo reserved_list[] = {
4956 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4957 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4958 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4959 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4960 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4961 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4963 # if ENABLE_HUSH_LOOPS
4964 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4965 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4966 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4967 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4968 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4969 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4971 # if ENABLE_HUSH_CASE
4972 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4973 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4976 const struct reserved_combo *r;
4978 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4979 if (strcmp(word->data, r->literal) == 0)
4984 /* Return 0: not a keyword, 1: keyword
4986 static int reserved_word(o_string *word, struct parse_context *ctx)
4988 # if ENABLE_HUSH_CASE
4989 static const struct reserved_combo reserved_match = {
4990 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4993 const struct reserved_combo *r;
4997 r = match_reserved_word(word);
5001 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5002 # if ENABLE_HUSH_CASE
5003 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5004 /* "case word IN ..." - IN part starts first MATCH part */
5005 r = &reserved_match;
5008 if (r->flag == 0) { /* '!' */
5009 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5010 syntax_error("! ! command");
5011 ctx->ctx_res_w = RES_SNTX;
5013 ctx->ctx_inverted = 1;
5016 if (r->flag & FLAG_START) {
5017 struct parse_context *old;
5019 old = xmalloc(sizeof(*old));
5020 debug_printf_parse("push stack %p\n", old);
5021 *old = *ctx; /* physical copy */
5022 initialize_context(ctx);
5024 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5025 syntax_error_at(word->data);
5026 ctx->ctx_res_w = RES_SNTX;
5029 /* "{...} fi" is ok. "{...} if" is not
5031 * if { echo foo; } then { echo bar; } fi */
5032 if (ctx->command->group)
5033 done_pipe(ctx, PIPE_SEQ);
5036 ctx->ctx_res_w = r->res;
5037 ctx->old_flag = r->flag;
5038 word->o_assignment = r->assignment_flag;
5040 if (ctx->old_flag & FLAG_END) {
5041 struct parse_context *old;
5043 done_pipe(ctx, PIPE_SEQ);
5044 debug_printf_parse("pop stack %p\n", ctx->stack);
5046 old->command->group = ctx->list_head;
5047 old->command->cmd_type = CMD_NORMAL;
5049 o_addstr(&old->as_string, ctx->as_string.data);
5050 o_free_unsafe(&ctx->as_string);
5051 old->command->group_as_string = xstrdup(old->as_string.data);
5052 debug_printf_parse("pop, remembering as:'%s'\n",
5053 old->command->group_as_string);
5055 *ctx = *old; /* physical copy */
5060 #endif /* HAS_KEYWORDS */
5062 /* Word is complete, look at it and update parsing context.
5063 * Normal return is 0. Syntax errors return 1.
5064 * Note: on return, word is reset, but not o_free'd!
5066 static int done_word(o_string *word, struct parse_context *ctx)
5068 struct command *command = ctx->command;
5070 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5071 if (word->length == 0 && word->o_quoted == 0) {
5072 debug_printf_parse("done_word return 0: true null, ignored\n");
5076 if (ctx->pending_redirect) {
5077 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5078 * only if run as "bash", not "sh" */
5079 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5081 * ...the word that follows the redirection operator
5082 * shall be subjected to tilde expansion, parameter expansion,
5083 * command substitution, arithmetic expansion, and quote
5084 * removal. Pathname expansion shall not be performed
5085 * on the word by a non-interactive shell; an interactive
5086 * shell may perform it, but shall do so only when
5087 * the expansion would result in one word."
5089 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5090 /* Cater for >\file case:
5091 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5092 * Same with heredocs:
5093 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5095 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5096 unbackslash(ctx->pending_redirect->rd_filename);
5097 /* Is it <<"HEREDOC"? */
5098 if (word->o_quoted) {
5099 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5102 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5103 ctx->pending_redirect = NULL;
5105 /* If this word wasn't an assignment, next ones definitely
5106 * can't be assignments. Even if they look like ones. */
5107 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5108 && word->o_assignment != WORD_IS_KEYWORD
5110 word->o_assignment = NOT_ASSIGNMENT;
5112 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5113 command->assignment_cnt++;
5114 word->o_assignment = MAYBE_ASSIGNMENT;
5118 # if ENABLE_HUSH_CASE
5119 if (ctx->ctx_dsemicolon
5120 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5122 /* already done when ctx_dsemicolon was set to 1: */
5123 /* ctx->ctx_res_w = RES_MATCH; */
5124 ctx->ctx_dsemicolon = 0;
5127 if (!command->argv /* if it's the first word... */
5128 # if ENABLE_HUSH_LOOPS
5129 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5130 && ctx->ctx_res_w != RES_IN
5132 # if ENABLE_HUSH_CASE
5133 && ctx->ctx_res_w != RES_CASE
5136 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5137 if (reserved_word(word, ctx)) {
5138 o_reset_to_empty_unquoted(word);
5139 debug_printf_parse("done_word return %d\n",
5140 (ctx->ctx_res_w == RES_SNTX));
5141 return (ctx->ctx_res_w == RES_SNTX);
5143 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5144 if (strcmp(word->data, "export") == 0
5145 # if ENABLE_HUSH_LOCAL
5146 || strcmp(word->data, "local") == 0
5149 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5152 # if ENABLE_HUSH_BASH_COMPAT
5153 if (strcmp(word->data, "[[") == 0) {
5154 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5160 if (command->group) {
5161 /* "{ echo foo; } echo bar" - bad */
5162 syntax_error_at(word->data);
5163 debug_printf_parse("done_word return 1: syntax error, "
5164 "groups and arglists don't mix\n");
5167 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5168 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5169 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5170 /* (otherwise it's known to be not empty and is already safe) */
5172 /* exclude "$@" - it can expand to no word despite "" */
5173 char *p = word->data;
5174 while (p[0] == SPECIAL_VAR_SYMBOL
5175 && (p[1] & 0x7f) == '@'
5176 && p[2] == SPECIAL_VAR_SYMBOL
5180 if (p == word->data || p[0] != '\0') {
5181 /* saw no "$@", or not only "$@" but some
5182 * real text is there too */
5183 /* insert "empty variable" reference, this makes
5184 * e.g. "", $empty"" etc to not disappear */
5185 o_addchr(word, SPECIAL_VAR_SYMBOL);
5186 o_addchr(word, SPECIAL_VAR_SYMBOL);
5189 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5190 debug_print_strings("word appended to argv", command->argv);
5193 #if ENABLE_HUSH_LOOPS
5194 if (ctx->ctx_res_w == RES_FOR) {
5196 || !is_well_formed_var_name(command->argv[0], '\0')
5198 /* bash says just "not a valid identifier" */
5199 syntax_error("not a valid identifier in for");
5202 /* Force FOR to have just one word (variable name) */
5203 /* NB: basically, this makes hush see "for v in ..."
5204 * syntax as if it is "for v; in ...". FOR and IN become
5205 * two pipe structs in parse tree. */
5206 done_pipe(ctx, PIPE_SEQ);
5209 #if ENABLE_HUSH_CASE
5210 /* Force CASE to have just one word */
5211 if (ctx->ctx_res_w == RES_CASE) {
5212 done_pipe(ctx, PIPE_SEQ);
5216 o_reset_to_empty_unquoted(word);
5218 debug_printf_parse("done_word return 0\n");
5223 /* Peek ahead in the input to find out if we have a "&n" construct,
5224 * as in "2>&1", that represents duplicating a file descriptor.
5226 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5227 * REDIRFD_SYNTAX_ERR if syntax error,
5228 * REDIRFD_TO_FILE if no & was seen,
5229 * or the number found.
5232 #define parse_redir_right_fd(as_string, input) \
5233 parse_redir_right_fd(input)
5235 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5241 return REDIRFD_TO_FILE;
5243 ch = i_getch(input); /* get the & */
5244 nommu_addchr(as_string, ch);
5247 ch = i_getch(input);
5248 nommu_addchr(as_string, ch);
5249 return REDIRFD_CLOSE;
5253 while (ch != EOF && isdigit(ch)) {
5254 d = d*10 + (ch-'0');
5256 ch = i_getch(input);
5257 nommu_addchr(as_string, ch);
5262 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5264 bb_error_msg("ambiguous redirect");
5265 return REDIRFD_SYNTAX_ERR;
5268 /* Return code is 0 normal, 1 if a syntax error is detected
5270 static int parse_redirect(struct parse_context *ctx,
5273 struct in_str *input)
5275 struct command *command = ctx->command;
5276 struct redir_struct *redir;
5277 struct redir_struct **redirp;
5280 dup_num = REDIRFD_TO_FILE;
5281 if (style != REDIRECT_HEREDOC) {
5282 /* Check for a '>&1' type redirect */
5283 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5284 if (dup_num == REDIRFD_SYNTAX_ERR)
5287 int ch = i_peek(input);
5288 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5289 if (dup_num) { /* <<-... */
5290 ch = i_getch(input);
5291 nommu_addchr(&ctx->as_string, ch);
5296 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5297 int ch = i_peek(input);
5299 /* >|FILE redirect ("clobbering" >).
5300 * Since we do not support "set -o noclobber" yet,
5301 * >| and > are the same for now. Just eat |.
5303 ch = i_getch(input);
5304 nommu_addchr(&ctx->as_string, ch);
5308 /* Create a new redir_struct and append it to the linked list */
5309 redirp = &command->redirects;
5310 while ((redir = *redirp) != NULL) {
5311 redirp = &(redir->next);
5313 *redirp = redir = xzalloc(sizeof(*redir));
5314 /* redir->next = NULL; */
5315 /* redir->rd_filename = NULL; */
5316 redir->rd_type = style;
5317 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5319 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5320 redir_table[style].descrip);
5322 redir->rd_dup = dup_num;
5323 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5324 /* Erik had a check here that the file descriptor in question
5325 * is legit; I postpone that to "run time"
5326 * A "-" representation of "close me" shows up as a -3 here */
5327 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5328 redir->rd_fd, redir->rd_dup);
5330 /* Set ctx->pending_redirect, so we know what to do at the
5331 * end of the next parsed word. */
5332 ctx->pending_redirect = redir;
5337 /* If a redirect is immediately preceded by a number, that number is
5338 * supposed to tell which file descriptor to redirect. This routine
5339 * looks for such preceding numbers. In an ideal world this routine
5340 * needs to handle all the following classes of redirects...
5341 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5342 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5343 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5344 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5346 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5348 * ... If n is quoted, the number shall not be recognized as part of
5349 * the redirection expression. For example:
5351 * writes the character 2 into file a"
5352 * We are getting it right by setting ->o_quoted on any \<char>
5354 * A -1 return means no valid number was found,
5355 * the caller should use the appropriate default for this redirection.
5357 static int redirect_opt_num(o_string *o)
5361 if (o->data == NULL)
5363 num = bb_strtou(o->data, NULL, 10);
5364 if (errno || num < 0)
5366 o_reset_to_empty_unquoted(o);
5371 #define fetch_till_str(as_string, input, word, skip_tabs) \
5372 fetch_till_str(input, word, skip_tabs)
5374 static char *fetch_till_str(o_string *as_string,
5375 struct in_str *input,
5379 o_string heredoc = NULL_O_STRING;
5385 ch = i_getch(input);
5386 nommu_addchr(as_string, ch);
5388 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5389 heredoc.data[past_EOL] = '\0';
5390 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5391 return heredoc.data;
5394 o_addchr(&heredoc, ch);
5395 past_EOL = heredoc.length;
5398 ch = i_getch(input);
5399 nommu_addchr(as_string, ch);
5400 } while (skip_tabs && ch == '\t');
5401 } while (ch == '\n');
5404 o_free_unsafe(&heredoc);
5407 o_addchr(&heredoc, ch);
5408 nommu_addchr(as_string, ch);
5412 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5413 * and load them all. There should be exactly heredoc_cnt of them.
5415 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5417 struct pipe *pi = ctx->list_head;
5419 while (pi && heredoc_cnt) {
5421 struct command *cmd = pi->cmds;
5423 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5425 cmd->argv ? cmd->argv[0] : "NONE");
5426 for (i = 0; i < pi->num_cmds; i++) {
5427 struct redir_struct *redir = cmd->redirects;
5429 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5430 i, cmd->argv ? cmd->argv[0] : "NONE");
5432 if (redir->rd_type == REDIRECT_HEREDOC) {
5435 redir->rd_type = REDIRECT_HEREDOC2;
5436 /* redir->rd_dup is (ab)used to indicate <<- */
5437 p = fetch_till_str(&ctx->as_string, input,
5438 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5440 syntax_error("unexpected EOF in here document");
5443 free(redir->rd_filename);
5444 redir->rd_filename = p;
5447 redir = redir->next;
5454 /* Should be 0. If it isn't, it's a parse error */
5456 bb_error_msg_and_die("heredoc BUG 2");
5462 #if ENABLE_HUSH_TICK
5463 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5468 char **to_free = NULL;
5472 pid = BB_MMU ? fork() : vfork();
5474 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5476 if (pid == 0) { /* child */
5477 disable_restore_tty_pgrp_on_exit();
5478 /* Process substitution is not considered to be usual
5479 * 'command execution'.
5480 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5487 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5488 close(channel[0]); /* NB: close _first_, then move fd! */
5489 xmove_fd(channel[1], 1);
5490 /* Prevent it from trying to handle ctrl-z etc */
5491 IF_HUSH_JOB(G.run_list_level = 1;)
5492 /* Awful hack for `trap` or $(trap).
5494 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5495 * contains an example where "trap" is executed in a subshell:
5497 * save_traps=$(trap)
5499 * eval "$save_traps"
5501 * Standard does not say that "trap" in subshell shall print
5502 * parent shell's traps. It only says that its output
5503 * must have suitable form, but then, in the above example
5504 * (which is not supposed to be normative), it implies that.
5506 * bash (and probably other shell) does implement it
5507 * (traps are reset to defaults, but "trap" still shows them),
5508 * but as a result, "trap" logic is hopelessly messed up:
5511 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5512 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5513 * # true | trap <--- trap is in subshell - no output (ditto)
5514 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5515 * trap -- 'echo Ho' SIGWINCH
5516 * # echo `(trap)` <--- in subshell in subshell - output
5517 * trap -- 'echo Ho' SIGWINCH
5518 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5519 * trap -- 'echo Ho' SIGWINCH
5521 * The rules when to forget and when to not forget traps
5522 * get really complex and nonsensical.
5524 * Our solution: ONLY bare $(trap) or `trap` is special.
5526 s = skip_whitespace(s);
5527 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5529 static const char *const argv[] = { NULL, NULL };
5530 builtin_trap((char**)argv);
5531 exit(0); /* not _exit() - we need to fflush */
5534 reset_traps_to_defaults();
5535 parse_and_run_string(s);
5536 _exit(G.last_exitcode);
5538 /* We re-execute after vfork on NOMMU. This makes this script safe:
5539 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5540 * huge=`cat BIG` # was blocking here forever
5543 re_execute_shell(&to_free,
5553 # if ENABLE_HUSH_FAST
5555 //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);
5557 enable_restore_tty_pgrp_on_exit();
5562 close_on_exec_on(channel[0]);
5563 return xfdopen_for_read(channel[0]);
5566 /* Return code is exit status of the process that is run. */
5567 static int process_command_subs(o_string *dest, const char *s)
5570 struct in_str pipe_str;
5572 int status, ch, eol_cnt;
5574 fp = generate_stream_from_string(s, &pid);
5576 /* Now send results of command back into original context */
5577 setup_file_in_str(&pipe_str, fp);
5579 while ((ch = i_getch(&pipe_str)) != EOF) {
5585 o_addchr(dest, '\n');
5588 o_addQchr(dest, ch);
5591 debug_printf("done reading from `cmd` pipe, closing it\n");
5593 /* We need to extract exitcode. Test case
5594 * "true; echo `sleep 1; false` $?"
5596 safe_waitpid(pid, &status, 0);
5597 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5598 return WEXITSTATUS(status);
5600 #endif /* ENABLE_HUSH_TICK */
5602 #if !ENABLE_HUSH_FUNCTIONS
5603 #define parse_group(dest, ctx, input, ch) \
5604 parse_group(ctx, input, ch)
5606 static int parse_group(o_string *dest, struct parse_context *ctx,
5607 struct in_str *input, int ch)
5609 /* dest contains characters seen prior to ( or {.
5610 * Typically it's empty, but for function defs,
5611 * it contains function name (without '()'). */
5612 struct pipe *pipe_list;
5614 struct command *command = ctx->command;
5616 debug_printf_parse("parse_group entered\n");
5617 #if ENABLE_HUSH_FUNCTIONS
5618 if (ch == '(' && !dest->o_quoted) {
5620 if (done_word(dest, ctx))
5623 goto skip; /* (... */
5624 if (command->argv[1]) { /* word word ... (... */
5625 syntax_error_unexpected_ch('(');
5628 /* it is "word(..." or "word (..." */
5630 ch = i_getch(input);
5631 while (ch == ' ' || ch == '\t');
5633 syntax_error_unexpected_ch(ch);
5636 nommu_addchr(&ctx->as_string, ch);
5638 ch = i_getch(input);
5639 while (ch == ' ' || ch == '\t' || ch == '\n');
5641 syntax_error_unexpected_ch(ch);
5644 nommu_addchr(&ctx->as_string, ch);
5645 command->cmd_type = CMD_FUNCDEF;
5650 #if 0 /* Prevented by caller */
5651 if (command->argv /* word [word]{... */
5652 || dest->length /* word{... */
5653 || dest->o_quoted /* ""{... */
5656 debug_printf_parse("parse_group return 1: "
5657 "syntax error, groups and arglists don't mix\n");
5662 #if ENABLE_HUSH_FUNCTIONS
5668 command->cmd_type = CMD_SUBSHELL;
5670 /* bash does not allow "{echo...", requires whitespace */
5671 ch = i_getch(input);
5672 if (ch != ' ' && ch != '\t' && ch != '\n') {
5673 syntax_error_unexpected_ch(ch);
5676 nommu_addchr(&ctx->as_string, ch);
5681 char *as_string = NULL;
5683 pipe_list = parse_stream(&as_string, input, endch);
5686 o_addstr(&ctx->as_string, as_string);
5688 /* empty ()/{} or parse error? */
5689 if (!pipe_list || pipe_list == ERR_PTR) {
5690 /* parse_stream already emitted error msg */
5694 debug_printf_parse("parse_group return 1: "
5695 "parse_stream returned %p\n", pipe_list);
5698 command->group = pipe_list;
5700 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5701 command->group_as_string = as_string;
5702 debug_printf_parse("end of group, remembering as:'%s'\n",
5703 command->group_as_string);
5706 debug_printf_parse("parse_group return 0\n");
5708 /* command remains "open", available for possible redirects */
5711 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5712 /* Subroutines for copying $(...) and `...` things */
5713 static void add_till_backquote(o_string *dest, struct in_str *input);
5715 static void add_till_single_quote(o_string *dest, struct in_str *input)
5718 int ch = i_getch(input);
5720 syntax_error_unterm_ch('\'');
5721 /*xfunc_die(); - redundant */
5728 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5729 static void add_till_double_quote(o_string *dest, struct in_str *input)
5732 int ch = i_getch(input);
5734 syntax_error_unterm_ch('"');
5735 /*xfunc_die(); - redundant */
5739 if (ch == '\\') { /* \x. Copy both chars. */
5741 ch = i_getch(input);
5745 add_till_backquote(dest, input);
5749 //if (ch == '$') ...
5752 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5754 * "Within the backquoted style of command substitution, backslash
5755 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5756 * The search for the matching backquote shall be satisfied by the first
5757 * backquote found without a preceding backslash; during this search,
5758 * if a non-escaped backquote is encountered within a shell comment,
5759 * a here-document, an embedded command substitution of the $(command)
5760 * form, or a quoted string, undefined results occur. A single-quoted
5761 * or double-quoted string that begins, but does not end, within the
5762 * "`...`" sequence produces undefined results."
5764 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5766 static void add_till_backquote(o_string *dest, struct in_str *input)
5769 int ch = i_getch(input);
5771 syntax_error_unterm_ch('`');
5772 /*xfunc_die(); - redundant */
5777 /* \x. Copy both chars unless it is \` */
5778 int ch2 = i_getch(input);
5780 syntax_error_unterm_ch('`');
5781 /*xfunc_die(); - redundant */
5783 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5790 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5791 * quoting and nested ()s.
5792 * "With the $(command) style of command substitution, all characters
5793 * following the open parenthesis to the matching closing parenthesis
5794 * constitute the command. Any valid shell script can be used for command,
5795 * except a script consisting solely of redirections which produces
5796 * unspecified results."
5798 * echo $(echo '(TEST)' BEST) (TEST) BEST
5799 * echo $(echo 'TEST)' BEST) TEST) BEST
5800 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5802 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5806 int ch = i_getch(input);
5808 syntax_error_unterm_ch(')');
5809 /*xfunc_die(); - redundant */
5817 if (i_peek(input) == ')') {
5825 add_till_single_quote(dest, input);
5830 add_till_double_quote(dest, input);
5835 /* \x. Copy verbatim. Important for \(, \) */
5836 ch = i_getch(input);
5838 syntax_error_unterm_ch(')');
5839 /*xfunc_die(); - redundant */
5846 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5848 /* Return code: 0 for OK, 1 for syntax error */
5850 #define handle_dollar(as_string, dest, input) \
5851 handle_dollar(dest, input)
5853 static int handle_dollar(o_string *as_string,
5855 struct in_str *input)
5857 int ch = i_peek(input); /* first character after the $ */
5858 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5860 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5862 ch = i_getch(input);
5863 nommu_addchr(as_string, ch);
5865 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5867 debug_printf_parse(": '%c'\n", ch);
5868 o_addchr(dest, ch | quote_mask);
5871 if (!isalnum(ch) && ch != '_')
5873 ch = i_getch(input);
5874 nommu_addchr(as_string, ch);
5876 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5877 } else if (isdigit(ch)) {
5879 ch = i_getch(input);
5880 nommu_addchr(as_string, ch);
5881 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5882 debug_printf_parse(": '%c'\n", ch);
5883 o_addchr(dest, ch | quote_mask);
5884 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5885 } else switch (ch) {
5887 case '!': /* last bg pid */
5888 case '?': /* last exit code */
5889 case '#': /* number of args */
5890 case '*': /* args */
5891 case '@': /* args */
5892 goto make_one_char_var;
5894 bool first_char, all_digits;
5897 ch = i_getch(input);
5898 nommu_addchr(as_string, ch);
5899 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5901 /* TODO: maybe someone will try to escape the '}' */
5906 ch = i_getch(input);
5907 nommu_addchr(as_string, ch);
5914 /* ${#var}: length of var contents */
5921 /* They're being verbose and doing ${?} */
5922 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5927 && ( (all_digits && !isdigit(ch))
5928 || (!all_digits && !isalnum(ch) && ch != '_')
5931 /* handle parameter expansions
5932 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5937 case ':': /* null modifier */
5938 if (expansion == 0) {
5939 debug_printf_parse(": null modifier\n");
5944 case '#': /* remove prefix */
5945 case '%': /* remove suffix */
5946 if (expansion == 0) {
5947 debug_printf_parse(": remove suffix/prefix\n");
5952 case '-': /* default value */
5953 case '=': /* assign default */
5954 case '+': /* alternative */
5955 case '?': /* error indicate */
5956 debug_printf_parse(": parameter expansion\n");
5961 syntax_error_unterm_str("${name}");
5962 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5967 debug_printf_parse(": '%c'\n", ch);
5968 o_addchr(dest, ch | quote_mask);
5972 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5975 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
5980 ch = i_getch(input);
5981 nommu_addchr(as_string, ch);
5982 # if ENABLE_SH_MATH_SUPPORT
5983 if (i_peek(input) == '(') {
5984 ch = i_getch(input);
5985 nommu_addchr(as_string, ch);
5986 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5987 o_addchr(dest, /*quote_mask |*/ '+');
5991 add_till_closing_paren(dest, input, true);
5994 o_addstr(as_string, dest->data + pos);
5995 o_addchr(as_string, ')');
5996 o_addchr(as_string, ')');
5999 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6003 # if ENABLE_HUSH_TICK
6004 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6005 o_addchr(dest, quote_mask | '`');
6009 add_till_closing_paren(dest, input, false);
6012 o_addstr(as_string, dest->data + pos);
6013 o_addchr(as_string, ')');
6016 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6022 ch = i_getch(input);
6023 nommu_addchr(as_string, ch);
6025 if (isalnum(ch)) { /* it's $_name or $_123 */
6030 /* TODO: $_ and $-: */
6031 /* $_ Shell or shell script name; or last argument of last command
6032 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6033 * but in command's env, set to full pathname used to invoke it */
6034 /* $- Option flags set by set builtin or shell options (-i etc) */
6036 o_addQchr(dest, '$');
6038 debug_printf_parse("handle_dollar return 0\n");
6043 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6044 parse_stream_dquoted(dest, input, dquote_end)
6046 static int parse_stream_dquoted(o_string *as_string,
6048 struct in_str *input,
6055 ch = i_getch(input);
6057 nommu_addchr(as_string, ch);
6058 if (ch == dquote_end) { /* may be only '"' or EOF */
6059 if (dest->o_assignment == NOT_ASSIGNMENT)
6060 dest->o_escape ^= 1;
6061 debug_printf_parse("parse_stream_dquoted return 0\n");
6064 /* note: can't move it above ch == dquote_end check! */
6066 syntax_error_unterm_ch('"');
6067 /*xfunc_die(); - redundant */
6071 next = i_peek(input);
6073 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6074 ch, ch, dest->o_escape);
6077 syntax_error("\\<eof>");
6081 * "The backslash retains its special meaning [in "..."]
6082 * only when followed by one of the following characters:
6083 * $, `, ", \, or <newline>. A double quote may be quoted
6084 * within double quotes by preceding it with a backslash."
6086 if (strchr("$`\"\\\n", next) != NULL) {
6087 ch = i_getch(input);
6089 o_addqchr(dest, ch);
6090 nommu_addchr(as_string, ch);
6093 o_addqchr(dest, '\\');
6094 nommu_addchr(as_string, '\\');
6099 if (handle_dollar(as_string, dest, input) != 0) {
6100 debug_printf_parse("parse_stream_dquoted return 1: "
6101 "handle_dollar returned non-0\n");
6106 #if ENABLE_HUSH_TICK
6108 //int pos = dest->length;
6109 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6110 o_addchr(dest, 0x80 | '`');
6111 add_till_backquote(dest, input);
6112 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6113 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6117 o_addQchr(dest, ch);
6119 && (dest->o_assignment == MAYBE_ASSIGNMENT
6120 || dest->o_assignment == WORD_IS_KEYWORD)
6121 && is_well_formed_var_name(dest->data, '=')
6123 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6129 * Scan input until EOF or end_trigger char.
6130 * Return a list of pipes to execute, or NULL on EOF
6131 * or if end_trigger character is met.
6132 * On syntax error, exit is shell is not interactive,
6133 * reset parsing machinery and start parsing anew,
6134 * or return ERR_PTR.
6136 static struct pipe *parse_stream(char **pstring,
6137 struct in_str *input,
6140 struct parse_context ctx;
6141 o_string dest = NULL_O_STRING;
6145 /* Double-quote state is handled in the state variable is_in_dquote.
6146 * A single-quote triggers a bypass of the main loop until its mate is
6147 * found. When recursing, quote state is passed in via dest->o_escape.
6149 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6150 end_trigger ? end_trigger : 'X');
6153 /* If very first arg is "" or '', dest.data may end up NULL.
6154 * Preventing this: */
6155 o_addchr(&dest, '\0');
6158 G.ifs = get_local_var_value("IFS");
6163 #if ENABLE_HUSH_INTERACTIVE
6164 input->promptmode = 0; /* PS1 */
6166 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6167 initialize_context(&ctx);
6172 const char *is_special;
6176 redir_type redir_style;
6179 /* dest.o_quoted = 1; - already is (see below) */
6180 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6183 /* We reached closing '"' */
6186 ch = i_getch(input);
6187 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6188 ch, ch, dest.o_escape);
6193 syntax_error_unterm_str("here document");
6196 /* end_trigger == '}' case errors out earlier,
6197 * checking only ')' */
6198 if (end_trigger == ')') {
6199 syntax_error_unterm_ch('('); /* exits */
6200 /* goto parse_error; */
6203 if (done_word(&dest, &ctx)) {
6207 done_pipe(&ctx, PIPE_SEQ);
6209 /* If we got nothing... */
6210 /* (this makes bare "&" cmd a no-op.
6211 * bash says: "syntax error near unexpected token '&'") */
6212 if (pi->num_cmds == 0
6213 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6219 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6221 *pstring = ctx.as_string.data;
6223 o_free_unsafe(&ctx.as_string);
6226 debug_printf_parse("parse_stream return %p\n", pi);
6229 nommu_addchr(&ctx.as_string, ch);
6233 next = i_peek(input);
6235 is_special = "{}<>;&|()#'" /* special outside of "str" */
6236 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6237 /* Are { and } special here? */
6238 if (ctx.command->argv /* word [word]{... - non-special */
6239 || dest.length /* word{... - non-special */
6240 || dest.o_quoted /* ""{... - non-special */
6241 || (next != ';' /* }; - special */
6242 && next != ')' /* }) - special */
6243 && next != '&' /* }& and }&& ... - special */
6244 && next != '|' /* }|| ... - special */
6245 && !strchr(G.ifs, next) /* {word - non-special */
6248 /* They are not special, skip "{}" */
6251 is_special = strchr(is_special, ch);
6252 is_ifs = strchr(G.ifs, ch);
6254 if (!is_special && !is_ifs) { /* ordinary char */
6256 o_addQchr(&dest, ch);
6257 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6258 || dest.o_assignment == WORD_IS_KEYWORD)
6260 && is_well_formed_var_name(dest.data, '=')
6262 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6268 if (done_word(&dest, &ctx)) {
6272 #if ENABLE_HUSH_CASE
6273 /* "case ... in <newline> word) ..." -
6274 * newlines are ignored (but ';' wouldn't be) */
6275 if (ctx.command->argv == NULL
6276 && ctx.ctx_res_w == RES_MATCH
6281 /* Treat newline as a command separator. */
6282 done_pipe(&ctx, PIPE_SEQ);
6283 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6285 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6290 dest.o_assignment = MAYBE_ASSIGNMENT;
6292 /* note: if (is_ifs) continue;
6293 * will still trigger for us */
6297 /* "cmd}" or "cmd }..." without semicolon or &:
6298 * } is an ordinary char in this case, even inside { cmd; }
6299 * Pathological example: { ""}; } should exec "}" cmd
6302 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6303 || dest.length != 0 /* word} */
6304 || dest.o_quoted /* ""} */
6308 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6309 goto skip_end_trigger;
6310 /* else: } does terminate a group */
6313 if (end_trigger && end_trigger == ch
6314 && (ch != ';' || heredoc_cnt == 0)
6315 #if ENABLE_HUSH_CASE
6317 || ctx.ctx_res_w != RES_MATCH
6318 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6323 /* This is technically valid:
6324 * { cat <<HERE; }; echo Ok
6328 * but we don't support this.
6329 * We require heredoc to be in enclosing {}/(),
6332 syntax_error_unterm_str("here document");
6335 if (done_word(&dest, &ctx)) {
6338 done_pipe(&ctx, PIPE_SEQ);
6339 dest.o_assignment = MAYBE_ASSIGNMENT;
6340 /* Do we sit outside of any if's, loops or case's? */
6342 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6346 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6348 *pstring = ctx.as_string.data;
6350 o_free_unsafe(&ctx.as_string);
6353 debug_printf_parse("parse_stream return %p: "
6354 "end_trigger char found\n",
6356 return ctx.list_head;
6363 /* Catch <, > before deciding whether this word is
6364 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6367 redir_fd = redirect_opt_num(&dest);
6368 if (done_word(&dest, &ctx)) {
6371 redir_style = REDIRECT_OVERWRITE;
6373 redir_style = REDIRECT_APPEND;
6374 ch = i_getch(input);
6375 nommu_addchr(&ctx.as_string, ch);
6378 else if (next == '(') {
6379 syntax_error(">(process) not supported");
6383 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6385 continue; /* back to top of while (1) */
6387 redir_fd = redirect_opt_num(&dest);
6388 if (done_word(&dest, &ctx)) {
6391 redir_style = REDIRECT_INPUT;
6393 redir_style = REDIRECT_HEREDOC;
6395 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6396 ch = i_getch(input);
6397 nommu_addchr(&ctx.as_string, ch);
6398 } else if (next == '>') {
6399 redir_style = REDIRECT_IO;
6400 ch = i_getch(input);
6401 nommu_addchr(&ctx.as_string, ch);
6404 else if (next == '(') {
6405 syntax_error("<(process) not supported");
6409 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6411 continue; /* back to top of while (1) */
6414 if (dest.o_assignment == MAYBE_ASSIGNMENT
6415 /* check that we are not in word in "a=1 2>word b=1": */
6416 && !ctx.pending_redirect
6418 /* ch is a special char and thus this word
6419 * cannot be an assignment */
6420 dest.o_assignment = NOT_ASSIGNMENT;
6423 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6427 if (dest.length == 0) {
6430 if (ch == EOF || ch == '\n')
6433 /* note: we do not add it to &ctx.as_string */
6435 nommu_addchr(&ctx.as_string, '\n');
6437 o_addQchr(&dest, ch);
6442 syntax_error("\\<eof>");
6445 ch = i_getch(input);
6447 o_addchr(&dest, '\\');
6448 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6449 o_addchr(&dest, ch);
6450 nommu_addchr(&ctx.as_string, ch);
6451 /* Example: echo Hello \2>file
6452 * we need to know that word 2 is quoted */
6457 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6458 ctx.as_string.data[--ctx.as_string.length] = '\0';
6463 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6464 debug_printf_parse("parse_stream parse error: "
6465 "handle_dollar returned non-0\n");
6472 ch = i_getch(input);
6474 syntax_error_unterm_ch('\'');
6475 /*xfunc_die(); - redundant */
6477 nommu_addchr(&ctx.as_string, ch);
6480 o_addqchr(&dest, ch);
6485 is_in_dquote ^= 1; /* invert */
6486 if (dest.o_assignment == NOT_ASSIGNMENT)
6489 #if ENABLE_HUSH_TICK
6494 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6495 o_addchr(&dest, '`');
6499 add_till_backquote(&dest, input);
6501 o_addstr(&ctx.as_string, dest.data + pos);
6502 o_addchr(&ctx.as_string, '`');
6504 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6505 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6510 #if ENABLE_HUSH_CASE
6513 if (done_word(&dest, &ctx)) {
6516 done_pipe(&ctx, PIPE_SEQ);
6517 #if ENABLE_HUSH_CASE
6518 /* Eat multiple semicolons, detect
6519 * whether it means something special */
6524 ch = i_getch(input);
6525 nommu_addchr(&ctx.as_string, ch);
6526 if (ctx.ctx_res_w == RES_CASE_BODY) {
6527 ctx.ctx_dsemicolon = 1;
6528 ctx.ctx_res_w = RES_MATCH;
6534 /* We just finished a cmd. New one may start
6535 * with an assignment */
6536 dest.o_assignment = MAYBE_ASSIGNMENT;
6539 if (done_word(&dest, &ctx)) {
6543 ch = i_getch(input);
6544 nommu_addchr(&ctx.as_string, ch);
6545 done_pipe(&ctx, PIPE_AND);
6547 done_pipe(&ctx, PIPE_BG);
6551 if (done_word(&dest, &ctx)) {
6554 #if ENABLE_HUSH_CASE
6555 if (ctx.ctx_res_w == RES_MATCH)
6556 break; /* we are in case's "word | word)" */
6558 if (next == '|') { /* || */
6559 ch = i_getch(input);
6560 nommu_addchr(&ctx.as_string, ch);
6561 done_pipe(&ctx, PIPE_OR);
6563 /* we could pick up a file descriptor choice here
6564 * with redirect_opt_num(), but bash doesn't do it.
6565 * "echo foo 2| cat" yields "foo 2". */
6568 o_reset_to_empty_unquoted(&ctx.as_string);
6573 #if ENABLE_HUSH_CASE
6574 /* "case... in [(]word)..." - skip '(' */
6575 if (ctx.ctx_res_w == RES_MATCH
6576 && ctx.command->argv == NULL /* not (word|(... */
6577 && dest.length == 0 /* not word(... */
6578 && dest.o_quoted == 0 /* not ""(... */
6584 if (parse_group(&dest, &ctx, input, ch) != 0) {
6589 #if ENABLE_HUSH_CASE
6590 if (ctx.ctx_res_w == RES_MATCH)
6594 /* proper use of this character is caught by end_trigger:
6595 * if we see {, we call parse_group(..., end_trigger='}')
6596 * and it will match } earlier (not here). */
6597 syntax_error_unexpected_ch(ch);
6601 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6607 struct parse_context *pctx;
6608 IF_HAS_KEYWORDS(struct parse_context *p2;)
6610 /* Clean up allocated tree.
6611 * Sample for finding leaks on syntax error recovery path.
6612 * Run it from interactive shell, watch pmap `pidof hush`.
6613 * while if false; then false; fi; do break; fi
6614 * Samples to catch leaks at execution:
6615 * while if (true | {true;}); then echo ok; fi; do break; done
6616 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6620 /* Update pipe/command counts,
6621 * otherwise freeing may miss some */
6622 done_pipe(pctx, PIPE_SEQ);
6623 debug_printf_clean("freeing list %p from ctx %p\n",
6624 pctx->list_head, pctx);
6625 debug_print_tree(pctx->list_head, 0);
6626 free_pipe_list(pctx->list_head);
6627 debug_printf_clean("freed list %p\n", pctx->list_head);
6629 o_free_unsafe(&pctx->as_string);
6631 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6635 IF_HAS_KEYWORDS(pctx = p2;)
6636 } while (HAS_KEYWORDS && pctx);
6637 /* Free text, clear all dest fields */
6639 /* If we are not in top-level parse, we return,
6640 * our caller will propagate error.
6642 if (end_trigger != ';') {
6650 /* Discard cached input, force prompt */
6652 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6657 /* Executing from string: eval, sh -c '...'
6658 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6659 * end_trigger controls how often we stop parsing
6660 * NUL: parse all, execute, return
6661 * ';': parse till ';' or newline, execute, repeat till EOF
6663 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6665 /* Why we need empty flag?
6666 * An obscure corner case "false; ``; echo $?":
6667 * empty command in `` should still set $? to 0.
6668 * But we can't just set $? to 0 at the start,
6669 * this breaks "false; echo `echo $?`" case.
6673 struct pipe *pipe_list;
6675 pipe_list = parse_stream(NULL, inp, end_trigger);
6676 if (!pipe_list) { /* EOF */
6678 G.last_exitcode = 0;
6681 debug_print_tree(pipe_list, 0);
6682 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6683 run_and_free_list(pipe_list);
6688 static void parse_and_run_string(const char *s)
6690 struct in_str input;
6691 setup_string_in_str(&input, s);
6692 parse_and_run_stream(&input, '\0');
6695 static void parse_and_run_file(FILE *f)
6697 struct in_str input;
6698 setup_file_in_str(&input, f);
6699 parse_and_run_stream(&input, ';');
6702 /* Called a few times only (or even once if "sh -c") */
6703 static void init_sigmasks(void)
6707 sigset_t old_blocked_set;
6709 if (!G.inherited_set_is_saved) {
6710 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6711 G.inherited_set = G.blocked_set;
6713 old_blocked_set = G.blocked_set;
6715 mask = (1 << SIGQUIT);
6716 if (G_interactive_fd) {
6717 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6718 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6719 mask |= SPECIAL_JOB_SIGS;
6721 G.non_DFL_mask = mask;
6726 sigaddset(&G.blocked_set, sig);
6730 sigdelset(&G.blocked_set, SIGCHLD);
6732 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6733 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6735 /* POSIX allows shell to re-enable SIGCHLD
6736 * even if it was SIG_IGN on entry */
6737 #if ENABLE_HUSH_FAST
6738 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6739 if (!G.inherited_set_is_saved)
6740 signal(SIGCHLD, SIGCHLD_handler);
6742 if (!G.inherited_set_is_saved)
6743 signal(SIGCHLD, SIG_DFL);
6746 G.inherited_set_is_saved = 1;
6751 static void maybe_set_to_sigexit(int sig)
6753 void (*handler)(int);
6754 /* non_DFL_mask'ed signals are, well, masked,
6755 * no need to set handler for them.
6757 if (!((G.non_DFL_mask >> sig) & 1)) {
6758 handler = signal(sig, sigexit);
6759 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6760 signal(sig, handler);
6763 /* Set handlers to restore tty pgrp and exit */
6764 static void set_fatal_handlers(void)
6766 /* We _must_ restore tty pgrp on fatal signals */
6768 maybe_set_to_sigexit(SIGILL );
6769 maybe_set_to_sigexit(SIGFPE );
6770 maybe_set_to_sigexit(SIGBUS );
6771 maybe_set_to_sigexit(SIGSEGV);
6772 maybe_set_to_sigexit(SIGTRAP);
6773 } /* else: hush is perfect. what SEGV? */
6774 maybe_set_to_sigexit(SIGABRT);
6775 /* bash 3.2 seems to handle these just like 'fatal' ones */
6776 maybe_set_to_sigexit(SIGPIPE);
6777 maybe_set_to_sigexit(SIGALRM);
6778 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6779 * if we aren't interactive... but in this case
6780 * we never want to restore pgrp on exit, and this fn is not called */
6781 /*maybe_set_to_sigexit(SIGHUP );*/
6782 /*maybe_set_to_sigexit(SIGTERM);*/
6783 /*maybe_set_to_sigexit(SIGINT );*/
6787 static int set_mode(const char cstate, const char mode)
6789 int state = (cstate == '-' ? 1 : 0);
6791 case 'n': G.fake_mode = state; break;
6792 case 'x': /*G.debug_mode = state;*/ break;
6793 default: return EXIT_FAILURE;
6795 return EXIT_SUCCESS;
6798 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6799 int hush_main(int argc, char **argv)
6801 static const struct variable const_shell_ver = {
6803 .varstr = (char*)hush_version_str,
6804 .max_len = 1, /* 0 can provoke free(name) */
6809 unsigned builtin_argc;
6811 struct variable *cur_var;
6814 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6815 G.last_exitcode = EXIT_SUCCESS;
6817 G.argv0_for_re_execing = argv[0];
6819 /* Deal with HUSH_VERSION */
6820 G.shell_ver = const_shell_ver; /* copying struct here */
6821 G.top_var = &G.shell_ver;
6822 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6823 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6824 /* Initialize our shell local variables with the values
6825 * currently living in the environment */
6826 cur_var = G.top_var;
6829 char *value = strchr(*e, '=');
6830 if (value) { /* paranoia */
6831 cur_var->next = xzalloc(sizeof(*cur_var));
6832 cur_var = cur_var->next;
6833 cur_var->varstr = *e;
6834 cur_var->max_len = strlen(*e);
6835 cur_var->flg_export = 1;
6839 /* reinstate HUSH_VERSION */
6840 debug_printf_env("putenv '%s'\n", hush_version_str);
6841 putenv((char *)hush_version_str);
6844 set_pwd_var(/*exp:*/ 1);
6845 /* bash also exports SHLVL and _,
6846 * and sets (but doesn't export) the following variables:
6848 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6849 * BASH_VERSION='3.2.0(1)-release'
6851 * MACHTYPE=i386-pc-linux-gnu
6853 * HOSTNAME=<xxxxxxxxxx>
6854 * PPID=<NNNNN> - we also do it elsewhere
6865 * PIPESTATUS=([0]="0")
6866 * HISTFILE=/<xxx>/.bash_history
6870 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6872 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6882 #if ENABLE_FEATURE_EDITING
6883 G.line_input_state = new_line_input_t(FOR_SHELL);
6885 G.global_argc = argc;
6886 G.global_argv = argv;
6887 /* Initialize some more globals to non-zero values */
6888 cmdedit_update_prompt();
6890 if (setjmp(die_jmp)) {
6891 /* xfunc has failed! die die die */
6892 /* no EXIT traps, this is an escape hatch! */
6894 hush_exit(xfunc_error_retval);
6897 /* Shell is non-interactive at first. We need to call
6898 * init_sigmasks() if we are going to execute "sh <script>",
6899 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6900 * If we later decide that we are interactive, we run init_sigmasks()
6901 * in order to intercept (more) signals.
6905 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6908 opt = getopt(argc, argv, "+c:xins"
6911 # if ENABLE_HUSH_FUNCTIONS
6921 * sh ... -c 'script'
6922 * sh ... -c 'script' ARG0 [ARG1...]
6923 * On NOMMU, if builtin_argc != 0,
6924 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
6925 * "" needs to be replaced with NULL
6926 * and BARGV vector fed to builtin function.
6927 * Note: the form without ARG0 never happens:
6928 * sh ... -c 'builtin' BARGV... ""
6931 G.root_pid = getpid();
6932 G.root_ppid = getppid();
6934 G.global_argv = argv + optind;
6935 G.global_argc = argc - optind;
6937 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6938 const struct built_in_command *x;
6941 x = find_builtin(optarg);
6942 if (x) { /* paranoia */
6943 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6944 G.global_argv += builtin_argc;
6945 G.global_argv[-1] = NULL; /* replace "" */
6946 G.last_exitcode = x->b_function(argv + optind - 1);
6950 if (!G.global_argv[0]) {
6951 /* -c 'script' (no params): prevent empty $0 */
6952 G.global_argv--; /* points to argv[i] of 'script' */
6953 G.global_argv[0] = argv[0];
6955 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
6957 parse_and_run_string(optarg);
6960 /* Well, we cannot just declare interactiveness,
6961 * we have to have some stuff (ctty, etc) */
6962 /* G_interactive_fd++; */
6965 /* "-s" means "read from stdin", but this is how we always
6966 * operate, so simply do nothing here. */
6969 case '<': /* "big heredoc" support */
6970 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6973 unsigned long long empty_trap_mask;
6975 G.root_pid = bb_strtou(optarg, &optarg, 16);
6977 G.root_ppid = bb_strtou(optarg, &optarg, 16);
6979 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6981 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6983 builtin_argc = bb_strtou(optarg, &optarg, 16);
6985 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
6986 if (empty_trap_mask != 0) {
6989 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6990 for (sig = 1; sig < NSIG; sig++) {
6991 if (empty_trap_mask & (1LL << sig)) {
6992 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
6993 sigaddset(&G.blocked_set, sig);
6996 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6998 # if ENABLE_HUSH_LOOPS
7000 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7006 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7008 # if ENABLE_HUSH_FUNCTIONS
7010 struct function *funcp = new_function(optarg);
7011 /* funcp->name is already set to optarg */
7012 /* funcp->body is set to NULL. It's a special case. */
7013 funcp->body_as_string = argv[optind];
7021 if (!set_mode('-', opt))
7025 fprintf(stderr, "Usage: sh [FILE]...\n"
7026 " or: sh -c command [args]...\n\n");
7032 } /* option parsing loop */
7035 G.root_pid = getpid();
7036 G.root_ppid = getppid();
7039 /* If we are login shell... */
7040 if (argv[0] && argv[0][0] == '-') {
7042 debug_printf("sourcing /etc/profile\n");
7043 input = fopen_for_read("/etc/profile");
7044 if (input != NULL) {
7045 close_on_exec_on(fileno(input));
7047 parse_and_run_file(input);
7050 /* bash: after sourcing /etc/profile,
7051 * tries to source (in the given order):
7052 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7053 * stopping on first found. --noprofile turns this off.
7054 * bash also sources ~/.bash_logout on exit.
7055 * If called as sh, skips .bash_XXX files.
7062 * "bash <script>" (which is never interactive (unless -i?))
7063 * sources $BASH_ENV here (without scanning $PATH).
7064 * If called as sh, does the same but with $ENV.
7066 debug_printf("running script '%s'\n", argv[optind]);
7067 G.global_argv = argv + optind;
7068 G.global_argc = argc - optind;
7069 input = xfopen_for_read(argv[optind]);
7070 close_on_exec_on(fileno(input));
7072 parse_and_run_file(input);
7073 #if ENABLE_FEATURE_CLEAN_UP
7079 /* Up to here, shell was non-interactive. Now it may become one.
7080 * NB: don't forget to (re)run init_sigmasks() as needed.
7083 /* A shell is interactive if the '-i' flag was given,
7084 * or if all of the following conditions are met:
7086 * no arguments remaining or the -s flag given
7087 * standard input is a terminal
7088 * standard output is a terminal
7089 * Refer to Posix.2, the description of the 'sh' utility.
7092 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7093 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7094 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7095 if (G_saved_tty_pgrp < 0)
7096 G_saved_tty_pgrp = 0;
7098 /* try to dup stdin to high fd#, >= 255 */
7099 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7100 if (G_interactive_fd < 0) {
7101 /* try to dup to any fd */
7102 G_interactive_fd = dup(STDIN_FILENO);
7103 if (G_interactive_fd < 0) {
7105 G_interactive_fd = 0;
7106 G_saved_tty_pgrp = 0;
7109 // TODO: track & disallow any attempts of user
7110 // to (inadvertently) close/redirect G_interactive_fd
7112 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7113 if (G_interactive_fd) {
7114 close_on_exec_on(G_interactive_fd);
7116 if (G_saved_tty_pgrp) {
7117 /* If we were run as 'hush &', sleep until we are
7118 * in the foreground (tty pgrp == our pgrp).
7119 * If we get started under a job aware app (like bash),
7120 * make sure we are now in charge so we don't fight over
7121 * who gets the foreground */
7123 pid_t shell_pgrp = getpgrp();
7124 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7125 if (G_saved_tty_pgrp == shell_pgrp)
7127 /* send TTIN to ourself (should stop us) */
7128 kill(- shell_pgrp, SIGTTIN);
7132 /* Block some signals */
7135 if (G_saved_tty_pgrp) {
7136 /* Set other signals to restore saved_tty_pgrp */
7137 set_fatal_handlers();
7138 /* Put ourselves in our own process group
7139 * (bash, too, does this only if ctty is available) */
7140 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7141 /* Grab control of the terminal */
7142 tcsetpgrp(G_interactive_fd, getpid());
7144 /* -1 is special - makes xfuncs longjmp, not exit
7145 * (we reset die_sleep = 0 whereever we [v]fork) */
7146 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7150 #elif ENABLE_HUSH_INTERACTIVE
7151 /* No job control compiled in, only prompt/line editing */
7152 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7153 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7154 if (G_interactive_fd < 0) {
7155 /* try to dup to any fd */
7156 G_interactive_fd = dup(STDIN_FILENO);
7157 if (G_interactive_fd < 0)
7159 G_interactive_fd = 0;
7162 if (G_interactive_fd) {
7163 close_on_exec_on(G_interactive_fd);
7167 /* We have interactiveness code disabled */
7171 * if interactive but not a login shell, sources ~/.bashrc
7172 * (--norc turns this off, --rcfile <file> overrides)
7175 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7176 /* note: ash and hush share this string */
7177 printf("\n\n%s %s\n"
7178 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7181 "hush - the humble shell"
7185 parse_and_run_file(stdin);
7188 #if ENABLE_FEATURE_CLEAN_UP
7189 if (G.cwd != bb_msg_unknown)
7191 cur_var = G.top_var->next;
7193 struct variable *tmp = cur_var;
7194 if (!cur_var->max_len)
7195 free(cur_var->varstr);
7196 cur_var = cur_var->next;
7200 hush_exit(G.last_exitcode);
7205 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7206 int lash_main(int argc, char **argv)
7208 bb_error_msg("lash is deprecated, please use hush instead");
7209 return hush_main(argc, argv);
7214 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7215 int msh_main(int argc, char **argv)
7217 //bb_error_msg("msh is deprecated, please use hush instead");
7218 return hush_main(argc, argv);
7226 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7231 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7238 return applet_main_func(argc, argv - argc);
7241 static int FAST_FUNC builtin_test(char **argv)
7243 return run_applet_main(argv, test_main);
7246 static int FAST_FUNC builtin_echo(char **argv)
7248 return run_applet_main(argv, echo_main);
7252 static int FAST_FUNC builtin_printf(char **argv)
7254 return run_applet_main(argv, printf_main);
7258 static int FAST_FUNC builtin_eval(char **argv)
7260 int rcode = EXIT_SUCCESS;
7263 char *str = expand_strvec_to_string(argv);
7265 * eval "echo Hi; done" ("done" is syntax error):
7266 * "echo Hi" will not execute too.
7268 parse_and_run_string(str);
7270 rcode = G.last_exitcode;
7275 static int FAST_FUNC builtin_cd(char **argv)
7277 const char *newdir = argv[1];
7278 if (newdir == NULL) {
7279 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7280 * bash says "bash: cd: HOME not set" and does nothing
7283 const char *home = get_local_var_value("HOME");
7284 newdir = home ? home : "/";
7286 if (chdir(newdir)) {
7287 /* Mimic bash message exactly */
7288 bb_perror_msg("cd: %s", newdir);
7289 return EXIT_FAILURE;
7291 /* Read current dir (get_cwd(1) is inside) and set PWD.
7292 * Note: do not enforce exporting. If PWD was unset or unexported,
7293 * set it again, but do not export. bash does the same.
7295 set_pwd_var(/*exp:*/ 0);
7296 return EXIT_SUCCESS;
7299 static int FAST_FUNC builtin_exec(char **argv)
7301 if (*++argv == NULL)
7302 return EXIT_SUCCESS; /* bash does this */
7304 /* Careful: we can end up here after [v]fork. Do not restore
7305 * tty pgrp then, only top-level shell process does that */
7306 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7307 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7309 /* TODO: if exec fails, bash does NOT exit! We do.
7310 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7311 * and tcsetpgrp, and this is inherently racy.
7313 execvp_or_die(argv);
7316 static int FAST_FUNC builtin_exit(char **argv)
7318 debug_printf_exec("%s()\n", __func__);
7320 /* interactive bash:
7321 * # trap "echo EEE" EXIT
7324 * There are stopped jobs.
7325 * (if there are _stopped_ jobs, running ones don't count)
7328 # EEE (then bash exits)
7330 * we can use G.exiting = -1 as indicator "last cmd was exit"
7333 /* note: EXIT trap is run by hush_exit */
7334 if (*++argv == NULL)
7335 hush_exit(G.last_exitcode);
7336 /* mimic bash: exit 123abc == exit 255 + error msg */
7337 xfunc_error_retval = 255;
7338 /* bash: exit -2 == exit 254, no error msg */
7339 hush_exit(xatoi(*argv) & 0xff);
7342 static void print_escaped(const char *s)
7347 const char *p = strchrnul(s, '\'');
7348 /* print 'xxxx', possibly just '' */
7349 printf("'%.*s'", (int)(p - s), s);
7354 /* s points to '; print "'''...'''" */
7356 do putchar('\''); while (*++s == '\'');
7361 #if !ENABLE_HUSH_LOCAL
7362 #define helper_export_local(argv, exp, lvl) \
7363 helper_export_local(argv, exp)
7365 static void helper_export_local(char **argv, int exp, int lvl)
7370 /* So far we do not check that name is valid (TODO?) */
7372 if (strchr(name, '=') == NULL) {
7373 struct variable *var;
7375 var = get_local_var(name);
7376 if (exp == -1) { /* unexporting? */
7377 /* export -n NAME (without =VALUE) */
7379 var->flg_export = 0;
7380 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7382 } /* else: export -n NOT_EXISTING_VAR: no-op */
7385 if (exp == 1) { /* exporting? */
7386 /* export NAME (without =VALUE) */
7388 var->flg_export = 1;
7389 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7390 putenv(var->varstr);
7394 /* Exporting non-existing variable.
7395 * bash does not put it in environment,
7396 * but remembers that it is exported,
7397 * and does put it in env when it is set later.
7398 * We just set it to "" and export. */
7399 /* Or, it's "local NAME" (without =VALUE).
7400 * bash sets the value to "". */
7401 name = xasprintf("%s=", name);
7403 /* (Un)exporting/making local NAME=VALUE */
7404 name = xstrdup(name);
7406 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7410 static int FAST_FUNC builtin_export(char **argv)
7412 unsigned opt_unexport;
7414 #if ENABLE_HUSH_EXPORT_N
7415 /* "!": do not abort on errors */
7416 opt_unexport = getopt32(argv, "!n");
7417 if (opt_unexport == (uint32_t)-1)
7418 return EXIT_FAILURE;
7425 if (argv[0] == NULL) {
7432 /* ash emits: export VAR='VAL'
7433 * bash: declare -x VAR="VAL"
7434 * we follow ash example */
7435 const char *s = *e++;
7436 const char *p = strchr(s, '=');
7438 if (!p) /* wtf? take next variable */
7441 printf("export %.*s", (int)(p - s) + 1, s);
7442 print_escaped(p + 1);
7446 /*fflush_all(); - done after each builtin anyway */
7448 return EXIT_SUCCESS;
7451 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7453 return EXIT_SUCCESS;
7456 #if ENABLE_HUSH_LOCAL
7457 static int FAST_FUNC builtin_local(char **argv)
7459 if (G.func_nest_level == 0) {
7460 bb_error_msg("%s: not in a function", argv[0]);
7461 return EXIT_FAILURE; /* bash compat */
7463 helper_export_local(argv, 0, G.func_nest_level);
7464 return EXIT_SUCCESS;
7468 static int FAST_FUNC builtin_trap(char **argv)
7474 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7479 /* No args: print all trapped */
7480 for (i = 0; i < NSIG; ++i) {
7483 print_escaped(G.traps[i]);
7484 /* note: bash adds "SIG", but only if invoked
7485 * as "bash". If called as "sh", or if set -o posix,
7486 * then it prints short signal names.
7487 * We are printing short names: */
7488 printf(" %s\n", get_signame(i));
7491 /*fflush_all(); - done after each builtin anyway */
7492 return EXIT_SUCCESS;
7496 /* If first arg is a number: reset all specified signals */
7497 sig = bb_strtou(*argv, NULL, 10);
7503 sig = get_signum(*argv++);
7504 if (sig < 0 || sig >= NSIG) {
7506 /* Mimic bash message exactly */
7507 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7512 G.traps[sig] = xstrdup(new_cmd);
7514 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7515 get_signame(sig), sig, G.traps[sig]);
7517 /* There is no signal for 0 (EXIT) */
7522 sigaddset(&G.blocked_set, sig);
7524 /* There was a trap handler, we are removing it
7525 * (if sig has non-DFL handling,
7526 * we don't need to do anything) */
7527 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7529 sigdelset(&G.blocked_set, sig);
7532 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7536 if (!argv[1]) { /* no second arg */
7537 bb_error_msg("trap: invalid arguments");
7538 return EXIT_FAILURE;
7541 /* First arg is "-": reset all specified to default */
7542 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7543 /* Everything else: set arg as signal handler
7544 * (includes "" case, which ignores signal) */
7545 if (argv[0][0] == '-') {
7546 if (argv[0][1] == '\0') { /* "-" */
7547 /* new_cmd remains NULL: "reset these sigs" */
7550 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7553 /* else: "-something", no special meaning */
7558 goto process_sig_list;
7561 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7562 static int FAST_FUNC builtin_type(char **argv)
7564 int ret = EXIT_SUCCESS;
7570 if (0) {} /* make conditional compile easier below */
7571 /*else if (find_alias(*argv))
7572 type = "an alias";*/
7573 #if ENABLE_HUSH_FUNCTIONS
7574 else if (find_function(*argv))
7575 type = "a function";
7577 else if (find_builtin(*argv))
7578 type = "a shell builtin";
7579 else if ((path = find_in_path(*argv)) != NULL)
7582 bb_error_msg("type: %s: not found", *argv);
7587 printf("%s is %s\n", *argv, type);
7595 /* built-in 'fg' and 'bg' handler */
7596 static int FAST_FUNC builtin_fg_bg(char **argv)
7601 if (!G_interactive_fd)
7602 return EXIT_FAILURE;
7604 /* If they gave us no args, assume they want the last backgrounded task */
7606 for (pi = G.job_list; pi; pi = pi->next) {
7607 if (pi->jobid == G.last_jobid) {
7611 bb_error_msg("%s: no current job", argv[0]);
7612 return EXIT_FAILURE;
7614 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7615 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7616 return EXIT_FAILURE;
7618 for (pi = G.job_list; pi; pi = pi->next) {
7619 if (pi->jobid == jobnum) {
7623 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7624 return EXIT_FAILURE;
7626 /* TODO: bash prints a string representation
7627 * of job being foregrounded (like "sleep 1 | cat") */
7628 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7629 /* Put the job into the foreground. */
7630 tcsetpgrp(G_interactive_fd, pi->pgrp);
7633 /* Restart the processes in the job */
7634 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7635 for (i = 0; i < pi->num_cmds; i++) {
7636 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7637 pi->cmds[i].is_stopped = 0;
7639 pi->stopped_cmds = 0;
7641 i = kill(- pi->pgrp, SIGCONT);
7643 if (errno == ESRCH) {
7644 delete_finished_bg_job(pi);
7645 return EXIT_SUCCESS;
7647 bb_perror_msg("kill (SIGCONT)");
7650 if (argv[0][0] == 'f') {
7652 return checkjobs_and_fg_shell(pi);
7654 return EXIT_SUCCESS;
7658 #if ENABLE_HUSH_HELP
7659 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7661 const struct built_in_command *x;
7664 "Built-in commands:\n"
7665 "------------------\n");
7666 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7668 printf("%s\t%s\n", x->b_cmd, x->b_descr);
7671 return EXIT_SUCCESS;
7676 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7679 const char *status_string;
7681 for (job = G.job_list; job; job = job->next) {
7682 if (job->alive_cmds == job->stopped_cmds)
7683 status_string = "Stopped";
7685 status_string = "Running";
7687 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7689 return EXIT_SUCCESS;
7694 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7699 # ifdef M_TRIM_THRESHOLD
7700 /* Optional. Reduces probability of false positives */
7703 /* Crude attempt to find where "free memory" starts,
7704 * sans fragmentation. */
7706 l = (unsigned long)p;
7709 if (l < (unsigned long)p) l = (unsigned long)p;
7712 if (!G.memleak_value)
7713 G.memleak_value = l;
7715 l -= G.memleak_value;
7722 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7727 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7730 return EXIT_SUCCESS;
7733 static int FAST_FUNC builtin_read(char **argv)
7742 /* "!": do not abort on errors.
7743 * Option string must start with "sr" to match BUILTIN_READ_xxx
7745 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7746 if (read_flags == (uint32_t)-1)
7747 return EXIT_FAILURE;
7750 r = shell_builtin_read(set_local_var_from_halves,
7752 get_local_var_value("IFS"), /* can be NULL */
7760 if ((uintptr_t)r > 1) {
7761 bb_error_msg("%s", r);
7762 r = (char*)(uintptr_t)1;
7765 return (uintptr_t)r;
7768 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7769 * built-in 'set' handler
7771 * set [-abCefhmnuvx] [-o option] [argument...]
7772 * set [+abCefhmnuvx] [+o option] [argument...]
7773 * set -- [argument...]
7776 * Implementations shall support the options in both their hyphen and
7777 * plus-sign forms. These options can also be specified as options to sh.
7779 * Write out all variables and their values: set
7780 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7781 * Turn on the -x and -v options: set -xv
7782 * Unset all positional parameters: set --
7783 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7784 * Set the positional parameters to the expansion of x, even if x expands
7785 * with a leading '-' or '+': set -- $x
7787 * So far, we only support "set -- [argument...]" and some of the short names.
7789 static int FAST_FUNC builtin_set(char **argv)
7792 char **pp, **g_argv;
7793 char *arg = *++argv;
7797 for (e = G.top_var; e; e = e->next)
7799 return EXIT_SUCCESS;
7803 if (!strcmp(arg, "--")) {
7807 if (arg[0] != '+' && arg[0] != '-')
7809 for (n = 1; arg[n]; ++n)
7810 if (set_mode(arg[0], arg[n]))
7812 } while ((arg = *++argv) != NULL);
7813 /* Now argv[0] is 1st argument */
7816 return EXIT_SUCCESS;
7819 /* NB: G.global_argv[0] ($0) is never freed/changed */
7820 g_argv = G.global_argv;
7821 if (G.global_args_malloced) {
7827 G.global_args_malloced = 1;
7828 pp = xzalloc(sizeof(pp[0]) * 2);
7829 pp[0] = g_argv[0]; /* retain $0 */
7832 /* This realloc's G.global_argv */
7833 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7840 return EXIT_SUCCESS;
7842 /* Nothing known, so abort */
7844 bb_error_msg("set: %s: invalid option", arg);
7845 return EXIT_FAILURE;
7848 static int FAST_FUNC builtin_shift(char **argv)
7854 if (n >= 0 && n < G.global_argc) {
7855 if (G.global_args_malloced) {
7858 free(G.global_argv[m++]);
7861 memmove(&G.global_argv[1], &G.global_argv[n+1],
7862 G.global_argc * sizeof(G.global_argv[0]));
7863 return EXIT_SUCCESS;
7865 return EXIT_FAILURE;
7868 static int FAST_FUNC builtin_source(char **argv)
7873 #if ENABLE_HUSH_FUNCTIONS
7877 if (*++argv == NULL)
7878 return EXIT_FAILURE;
7880 if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
7881 input = fopen_for_read(arg_path);
7884 input = fopen_or_warn(*argv, "r");
7886 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7887 return EXIT_FAILURE;
7889 close_on_exec_on(fileno(input));
7891 #if ENABLE_HUSH_FUNCTIONS
7892 sv_flg = G.flag_return_in_progress;
7893 /* "we are inside sourced file, ok to use return" */
7894 G.flag_return_in_progress = -1;
7896 save_and_replace_G_args(&sv, argv);
7898 parse_and_run_file(input);
7901 restore_G_args(&sv, argv);
7902 #if ENABLE_HUSH_FUNCTIONS
7903 G.flag_return_in_progress = sv_flg;
7906 return G.last_exitcode;
7909 static int FAST_FUNC builtin_umask(char **argv)
7916 mode_t old_mask = mask;
7919 rc = bb_parse_mode(argv[1], &mask);
7924 * bash: umask: 'q': invalid symbolic mode operator
7925 * bash: umask: 999: octal number out of range
7927 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7932 printf("%04o\n", (unsigned) mask);
7933 /* fall through and restore mask which we set to 0 */
7937 return !rc; /* rc != 0 - success */
7940 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7941 static int FAST_FUNC builtin_unset(char **argv)
7946 /* "!": do not abort on errors */
7947 /* "+": stop at 1st non-option */
7948 opts = getopt32(argv, "!+vf");
7949 if (opts == (unsigned)-1)
7950 return EXIT_FAILURE;
7952 bb_error_msg("unset: -v and -f are exclusive");
7953 return EXIT_FAILURE;
7959 if (!(opts & 2)) { /* not -f */
7960 if (unset_local_var(*argv)) {
7961 /* unset <nonexistent_var> doesn't fail.
7962 * Error is when one tries to unset RO var.
7963 * Message was printed by unset_local_var. */
7967 #if ENABLE_HUSH_FUNCTIONS
7977 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7978 static int FAST_FUNC builtin_wait(char **argv)
7980 int ret = EXIT_SUCCESS;
7983 if (*++argv == NULL) {
7984 /* Don't care about wait results */
7985 /* Note 1: must wait until there are no more children */
7986 /* Note 2: must be interruptible */
7988 * $ sleep 3 & sleep 6 & wait
7993 * $ sleep 3 & sleep 6 & wait
7997 * ^C <-- after ~4 sec from keyboard
8000 sigaddset(&G.blocked_set, SIGCHLD);
8001 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8004 if (errno == ECHILD)
8006 /* Wait for SIGCHLD or any other signal of interest */
8007 /* sigtimedwait with infinite timeout: */
8008 sig = sigwaitinfo(&G.blocked_set, NULL);
8010 sig = check_and_run_traps(sig);
8011 if (sig && sig != SIGCHLD) { /* see note 2 */
8017 sigdelset(&G.blocked_set, SIGCHLD);
8018 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8022 /* This is probably buggy wrt interruptible-ness */
8024 pid_t pid = bb_strtou(*argv, NULL, 10);
8026 /* mimic bash message */
8027 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8028 return EXIT_FAILURE;
8030 if (waitpid(pid, &status, 0) == pid) {
8031 if (WIFSIGNALED(status))
8032 ret = 128 + WTERMSIG(status);
8033 else if (WIFEXITED(status))
8034 ret = WEXITSTATUS(status);
8038 bb_perror_msg("wait %s", *argv);
8047 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8048 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8051 def = bb_strtou(argv[1], NULL, 10);
8052 if (errno || def < def_min || argv[2]) {
8053 bb_error_msg("%s: bad arguments", argv[0]);
8061 #if ENABLE_HUSH_LOOPS
8062 static int FAST_FUNC builtin_break(char **argv)
8065 if (G.depth_of_loop == 0) {
8066 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8067 return EXIT_SUCCESS; /* bash compat */
8069 G.flag_break_continue++; /* BC_BREAK = 1 */
8071 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8072 if (depth == UINT_MAX)
8073 G.flag_break_continue = BC_BREAK;
8074 if (G.depth_of_loop < depth)
8075 G.depth_break_continue = G.depth_of_loop;
8077 return EXIT_SUCCESS;
8080 static int FAST_FUNC builtin_continue(char **argv)
8082 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8083 return builtin_break(argv);
8087 #if ENABLE_HUSH_FUNCTIONS
8088 static int FAST_FUNC builtin_return(char **argv)
8092 if (G.flag_return_in_progress != -1) {
8093 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8094 return EXIT_FAILURE; /* bash compat */
8097 G.flag_return_in_progress = 1;
8100 * out of range: wraps around at 256, does not error out
8101 * non-numeric param:
8102 * f() { false; return qwe; }; f; echo $?
8103 * bash: return: qwe: numeric argument required <== we do this
8104 * 255 <== we also do this
8106 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);