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:
45 * redirection of stdout+stderr: &> and >&
46 * brace expansion: one/{two,three,four}
47 * reserved words: function select
48 * advanced test: [[ ]]
49 * substrings: ${var:1:5}
50 * process substitution: <(list) and >(list)
53 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
54 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
55 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
57 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
58 * This is exactly equivalent to let "EXPR".
59 * $[EXPR]: synonym for $((EXPR))
62 * grep for "TODO" and fix (some of them are easy)
63 * special variables (done: PWD, PPID, RANDOM)
64 * follow IFS rules more precisely, including update semantics
65 * export builtin should be special, its arguments are assignments
66 * and therefore expansion of them should be "one-word" expansion:
67 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
69 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
70 * ls: cannot access i=a: No such file or directory
71 * ls: cannot access b: No such file or directory
72 * Note1: same applies to local builtin.
73 * Note2: bash 3.2.33(1) does this only if export word itself
75 * $ export i=`echo 'aaa bbb'`; echo "$i"
77 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
80 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
82 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
83 #include <malloc.h> /* for malloc_trim */
85 /* #include <dmalloc.h> */
90 #include "shell_common.h"
91 #include "builtin_read.h"
92 #include "builtin_ulimit.h"
95 #if ENABLE_HUSH_RANDOM_SUPPORT
98 # define CLEAR_RANDOM_T(rnd) ((void)0)
101 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
106 #define LEAK_HUNTING 0
107 #define BUILD_AS_NOMMU 0
108 /* Enable/disable sanity checks. Ok to enable in production,
109 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
110 * Keeping 1 for now even in released versions.
113 /* Slightly bigger (+200 bytes), but faster hush.
114 * So far it only enables a trick with counting SIGCHLDs and forks,
115 * which allows us to do fewer waitpid's.
116 * (we can detect a case where neither forks were done nor SIGCHLDs happened
117 * and therefore waitpid will return the same result as last time)
119 #define ENABLE_HUSH_FAST 0
124 # undef USE_FOR_NOMMU
127 # define USE_FOR_NOMMU(...) __VA_ARGS__
128 # define USE_FOR_MMU(...)
131 #define SKIP_definitions 1
132 #include "applet_tables.h"
133 #undef SKIP_definitions
135 /* STANDALONE does not make sense, and won't compile */
136 # undef CONFIG_FEATURE_SH_STANDALONE
137 # undef ENABLE_FEATURE_SH_STANDALONE
138 # undef IF_FEATURE_SH_STANDALONE
139 # undef IF_NOT_FEATURE_SH_STANDALONE
140 # define ENABLE_FEATURE_SH_STANDALONE 0
141 # define IF_FEATURE_SH_STANDALONE(...)
142 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
145 #if !ENABLE_HUSH_INTERACTIVE
146 # undef ENABLE_FEATURE_EDITING
147 # define ENABLE_FEATURE_EDITING 0
148 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
149 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
152 /* Do we support ANY keywords? */
153 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
154 # define HAS_KEYWORDS 1
155 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
156 # define IF_HAS_NO_KEYWORDS(...)
158 # define HAS_KEYWORDS 0
159 # define IF_HAS_KEYWORDS(...)
160 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
163 /* If you comment out one of these below, it will be #defined later
164 * to perform debug printfs to stderr: */
165 #define debug_printf(...) do {} while (0)
166 /* Finer-grained debug switches */
167 #define debug_printf_parse(...) do {} while (0)
168 #define debug_print_tree(a, b) do {} while (0)
169 #define debug_printf_exec(...) do {} while (0)
170 #define debug_printf_env(...) do {} while (0)
171 #define debug_printf_jobs(...) do {} while (0)
172 #define debug_printf_expand(...) do {} while (0)
173 #define debug_printf_glob(...) do {} while (0)
174 #define debug_printf_list(...) do {} while (0)
175 #define debug_printf_subst(...) do {} while (0)
176 #define debug_printf_clean(...) do {} while (0)
178 #define ERR_PTR ((void*)(long)1)
180 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
182 #define SPECIAL_VAR_SYMBOL 3
186 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
188 /* This supports saving pointers malloced in vfork child,
189 * to be freed in the parent.
192 typedef struct nommu_save_t {
194 struct variable *old_vars;
196 char **argv_from_re_execing;
200 typedef enum reserved_style {
209 #if ENABLE_HUSH_LOOPS
216 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
221 /* three pseudo-keywords support contrived "case" syntax: */
222 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
223 RES_MATCH , /* "word)" */
224 RES_CASE_BODY, /* "this command is inside CASE" */
231 typedef struct o_string {
233 int length; /* position where data is appended */
235 /* Protect newly added chars against globbing
236 * (by prepending \ to *, ?, [, \) */
239 /* At least some part of the string was inside '' or "",
240 * possibly empty one: word"", wo''rd etc. */
242 smallint has_empty_slot;
243 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
246 MAYBE_ASSIGNMENT = 0,
247 DEFINITELY_ASSIGNMENT = 1,
249 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
251 /* Used for initialization: o_string foo = NULL_O_STRING; */
252 #define NULL_O_STRING { NULL }
254 /* I can almost use ordinary FILE*. Is open_memstream() universally
255 * available? Where is it documented? */
256 typedef struct in_str {
258 /* eof_flag=1: last char in ->p is really an EOF */
259 char eof_flag; /* meaningless if ->p == NULL */
261 #if ENABLE_HUSH_INTERACTIVE
263 smallint promptmode; /* 0: PS1, 1: PS2 */
266 int (*get) (struct in_str *) FAST_FUNC;
267 int (*peek) (struct in_str *) FAST_FUNC;
269 #define i_getch(input) ((input)->get(input))
270 #define i_peek(input) ((input)->peek(input))
272 /* The descrip member of this structure is only used to make
273 * debugging output pretty */
274 static const struct {
276 signed char default_fd;
279 { O_RDONLY, 0, "<" },
280 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
281 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
282 { O_CREAT|O_RDWR, 1, "<>" },
283 { O_RDONLY, 0, "<<" },
284 /* Should not be needed. Bogus default_fd helps in debugging */
285 /* { O_RDONLY, 77, "<<" }, */
288 struct redir_struct {
289 struct redir_struct *next;
290 char *rd_filename; /* filename */
291 int rd_fd; /* fd to redirect */
292 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
294 smallint rd_type; /* (enum redir_type) */
295 /* note: for heredocs, rd_filename contains heredoc delimiter,
296 * and subsequently heredoc itself; and rd_dup is a bitmask:
297 * bit 0: do we need to trim leading tabs?
298 * bit 1: is heredoc quoted (<<'delim' syntax) ?
301 typedef enum redir_type {
303 REDIRECT_OVERWRITE = 1,
306 REDIRECT_HEREDOC = 4,
307 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
310 REDIRFD_SYNTAX_ERR = -2,
311 REDIRFD_TO_FILE = -1,
312 /* otherwise, rd_fd is redirected to rd_dup */
314 HEREDOC_SKIPTABS = 1,
320 pid_t pid; /* 0 if exited */
321 int assignment_cnt; /* how many argv[i] are assignments? */
322 smallint is_stopped; /* is the command currently running? */
323 smallint cmd_type; /* CMD_xxx */
325 #define CMD_SUBSHELL 1
327 /* used for "[[ EXPR ]]" */
328 #if ENABLE_HUSH_BASH_COMPAT
329 # define CMD_SINGLEWORD_NOGLOB 2
332 /* used for "export noglob=* glob* a=`echo a b`" */
333 //#define CMD_SINGLEWORD_NOGLOB_COND 3
334 // It is hard to implement correctly, it adds significant amounts of tricky code,
335 // and all this is only useful for really obscure export statements
336 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
337 // guards the code which implements it, but I have doubts it works
338 // in all cases (especially with mixed globbed/non-globbed arguments)
340 #if ENABLE_HUSH_FUNCTIONS
341 # define CMD_FUNCDEF 3
344 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
347 char *group_as_string;
349 #if ENABLE_HUSH_FUNCTIONS
350 struct function *child_func;
351 /* This field is used to prevent a bug here:
352 * while...do f1() {a;}; f1; f1() {b;}; f1; done
353 * When we execute "f1() {a;}" cmd, we create new function and clear
354 * cmd->group, cmd->group_as_string, cmd->argv[0].
355 * When we execute "f1() {b;}", we notice that f1 exists,
356 * and that its "parent cmd" struct is still "alive",
357 * we put those fields back into cmd->xxx
358 * (struct function has ->parent_cmd ptr to facilitate that).
359 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
360 * Without this trick, loop would execute a;b;b;b;...
361 * instead of correct sequence a;b;a;b;...
362 * When command is freed, it severs the link
363 * (sets ->child_func->parent_cmd to NULL).
366 char **argv; /* command name and arguments */
367 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
368 * and on execution these are substituted with their values.
369 * Substitution can make _several_ words out of one argv[n]!
370 * Example: argv[0]=='.^C*^C.' here: echo .$*.
371 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
373 struct redir_struct *redirects; /* I/O redirections */
375 /* Is there anything in this command at all? */
376 #define IS_NULL_CMD(cmd) \
377 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
382 int num_cmds; /* total number of commands in pipe */
383 int alive_cmds; /* number of commands running (not exited) */
384 int stopped_cmds; /* number of commands alive, but stopped */
386 int jobid; /* job number */
387 pid_t pgrp; /* process group ID for the job */
388 char *cmdtext; /* name of job */
390 struct command *cmds; /* array of commands in pipe */
391 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
392 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
393 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
395 typedef enum pipe_style {
401 /* Is there anything in this pipe at all? */
402 #define IS_NULL_PIPE(pi) \
403 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
405 /* This holds pointers to the various results of parsing */
406 struct parse_context {
407 /* linked list of pipes */
408 struct pipe *list_head;
409 /* last pipe (being constructed right now) */
411 /* last command in pipe (being constructed right now) */
412 struct command *command;
413 /* last redirect in command->redirects list */
414 struct redir_struct *pending_redirect;
420 smallint ctx_inverted; /* "! cmd | cmd" */
422 smallint ctx_dsemicolon; /* ";;" seen */
424 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
426 /* group we are enclosed in:
427 * example: "if pipe1; pipe2; then pipe3; fi"
428 * when we see "if" or "then", we malloc and copy current context,
429 * and make ->stack point to it. then we parse pipeN.
430 * when closing "then" / fi" / whatever is found,
431 * we move list_head into ->stack->command->group,
432 * copy ->stack into current context, and delete ->stack.
433 * (parsing of { list } and ( list ) doesn't use this method)
435 struct parse_context *stack;
439 /* On program start, environ points to initial environment.
440 * putenv adds new pointers into it, unsetenv removes them.
441 * Neither of these (de)allocates the strings.
442 * setenv allocates new strings in malloc space and does putenv,
443 * and thus setenv is unusable (leaky) for shell's purposes */
444 #define setenv(...) setenv_is_leaky_dont_use()
446 struct variable *next;
447 char *varstr; /* points to "name=" portion */
448 #if ENABLE_HUSH_LOCAL
449 unsigned func_nest_level;
451 int max_len; /* if > 0, name is part of initial env; else name is malloced */
452 smallint flg_export; /* putenv should be done on this var */
453 smallint flg_read_only;
461 #if ENABLE_HUSH_FUNCTIONS
463 struct function *next;
465 struct command *parent_cmd;
468 char *body_as_string;
474 /* "Globals" within this file */
475 /* Sorted roughly by size (smaller offsets == smaller code) */
477 /* interactive_fd != 0 means we are an interactive shell.
478 * If we are, then saved_tty_pgrp can also be != 0, meaning
479 * that controlling tty is available. With saved_tty_pgrp == 0,
480 * job control still works, but terminal signals
481 * (^C, ^Z, ^Y, ^\) won't work at all, and background
482 * process groups can only be created with "cmd &".
483 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
484 * to give tty to the foreground process group,
485 * and will take it back when the group is stopped (^Z)
488 #if ENABLE_HUSH_INTERACTIVE
489 /* 'interactive_fd' is a fd# open to ctty, if we have one
490 * _AND_ if we decided to act interactively */
494 # define G_interactive_fd (G.interactive_fd)
496 # define G_interactive_fd 0
498 #if ENABLE_FEATURE_EDITING
499 line_input_t *line_input_state;
504 #if ENABLE_HUSH_RANDOM_SUPPORT
510 pid_t saved_tty_pgrp;
511 struct pipe *job_list;
512 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
514 # define G_saved_tty_pgrp 0
516 smallint flag_SIGINT;
517 #if ENABLE_HUSH_LOOPS
518 smallint flag_break_continue;
520 #if ENABLE_HUSH_FUNCTIONS
521 /* 0: outside of a function (or sourced file)
522 * -1: inside of a function, ok to use return builtin
523 * 1: return is invoked, skip all till end of func
525 smallint flag_return_in_progress;
528 smallint exiting; /* used to prevent EXIT trap recursion */
529 /* These four support $?, $#, and $1 */
530 smalluint last_exitcode;
531 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
532 smalluint global_args_malloced;
533 smalluint inherited_set_is_saved;
534 /* how many non-NULL argv's we have. NB: $# + 1 */
538 char *argv0_for_re_execing;
540 #if ENABLE_HUSH_LOOPS
541 unsigned depth_break_continue;
542 unsigned depth_of_loop;
546 struct variable *top_var; /* = &G.shell_ver (set in main()) */
547 struct variable shell_ver;
548 #if ENABLE_HUSH_FUNCTIONS
549 struct function *top_func;
550 # if ENABLE_HUSH_LOCAL
551 struct variable **shadowed_vars_pp;
552 unsigned func_nest_level;
555 /* Signal and trap handling */
557 unsigned count_SIGCHLD;
558 unsigned handled_SIGCHLD;
559 smallint we_have_children;
561 /* which signals have non-DFL handler (even with no traps set)? */
562 unsigned non_DFL_mask;
563 char **traps; /* char *traps[NSIG] */
564 sigset_t blocked_set;
565 sigset_t inherited_set;
567 unsigned long memleak_value;
570 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
572 #define G (*ptr_to_globals)
573 /* Not #defining name to G.name - this quickly gets unwieldy
574 * (too many defines). Also, I actually prefer to see when a variable
575 * is global, thus "G." prefix is a useful hint */
576 #define INIT_G() do { \
577 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
581 /* Function prototypes for builtins */
582 static int builtin_cd(char **argv) FAST_FUNC;
583 static int builtin_echo(char **argv) FAST_FUNC;
584 static int builtin_eval(char **argv) FAST_FUNC;
585 static int builtin_exec(char **argv) FAST_FUNC;
586 static int builtin_exit(char **argv) FAST_FUNC;
587 static int builtin_export(char **argv) FAST_FUNC;
589 static int builtin_fg_bg(char **argv) FAST_FUNC;
590 static int builtin_jobs(char **argv) FAST_FUNC;
593 static int builtin_help(char **argv) FAST_FUNC;
595 #if ENABLE_HUSH_LOCAL
596 static int builtin_local(char **argv) FAST_FUNC;
599 static int builtin_memleak(char **argv) FAST_FUNC;
602 static int builtin_printf(char **argv) FAST_FUNC;
604 static int builtin_pwd(char **argv) FAST_FUNC;
605 static int builtin_read(char **argv) FAST_FUNC;
606 static int builtin_set(char **argv) FAST_FUNC;
607 static int builtin_shift(char **argv) FAST_FUNC;
608 static int builtin_source(char **argv) FAST_FUNC;
609 static int builtin_test(char **argv) FAST_FUNC;
610 static int builtin_trap(char **argv) FAST_FUNC;
611 static int builtin_type(char **argv) FAST_FUNC;
612 static int builtin_true(char **argv) FAST_FUNC;
613 static int builtin_umask(char **argv) FAST_FUNC;
614 static int builtin_unset(char **argv) FAST_FUNC;
615 static int builtin_wait(char **argv) FAST_FUNC;
616 #if ENABLE_HUSH_LOOPS
617 static int builtin_break(char **argv) FAST_FUNC;
618 static int builtin_continue(char **argv) FAST_FUNC;
620 #if ENABLE_HUSH_FUNCTIONS
621 static int builtin_return(char **argv) FAST_FUNC;
624 /* Table of built-in functions. They can be forked or not, depending on
625 * context: within pipes, they fork. As simple commands, they do not.
626 * When used in non-forking context, they can change global variables
627 * in the parent shell process. If forked, of course they cannot.
628 * For example, 'unset foo | whatever' will parse and run, but foo will
629 * still be set at the end. */
630 struct built_in_command {
632 int (*b_function)(char **argv) FAST_FUNC;
635 # define BLTIN(cmd, func, help) { cmd, func, help }
637 # define BLTIN(cmd, func, help) { cmd, func }
641 static const struct built_in_command bltins1[] = {
642 BLTIN("." , builtin_source , "Run commands in a file"),
643 BLTIN(":" , builtin_true , NULL),
645 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
647 #if ENABLE_HUSH_LOOPS
648 BLTIN("break" , builtin_break , "Exit from a loop"),
650 BLTIN("cd" , builtin_cd , "Change directory"),
651 #if ENABLE_HUSH_LOOPS
652 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
654 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
655 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
656 BLTIN("exit" , builtin_exit , "Exit"),
657 BLTIN("export" , builtin_export , "Set environment variables"),
659 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
662 BLTIN("help" , builtin_help , NULL),
665 BLTIN("jobs" , builtin_jobs , "List jobs"),
667 #if ENABLE_HUSH_LOCAL
668 BLTIN("local" , builtin_local , "Set local variables"),
671 BLTIN("memleak" , builtin_memleak , NULL),
673 BLTIN("read" , builtin_read , "Input into variable"),
674 #if ENABLE_HUSH_FUNCTIONS
675 BLTIN("return" , builtin_return , "Return from a function"),
677 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
678 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
679 #if ENABLE_HUSH_BASH_COMPAT
680 BLTIN("source" , builtin_source , "Run commands in a file"),
682 BLTIN("trap" , builtin_trap , "Trap signals"),
683 BLTIN("type" , builtin_type , "Show command type"),
684 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
685 BLTIN("umask" , builtin_umask , "Set file creation mask"),
686 BLTIN("unset" , builtin_unset , "Unset variables"),
687 BLTIN("wait" , builtin_wait , "Wait for process"),
689 /* For now, echo and test are unconditionally enabled.
690 * Maybe make it configurable? */
691 static const struct built_in_command bltins2[] = {
692 BLTIN("[" , builtin_test , NULL),
693 BLTIN("echo" , builtin_echo , NULL),
695 BLTIN("printf" , builtin_printf , NULL),
697 BLTIN("pwd" , builtin_pwd , NULL),
698 BLTIN("test" , builtin_test , NULL),
705 /* prevent disasters with G.debug_indent < 0 */
706 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
707 # define debug_enter() (G.debug_indent++)
708 # define debug_leave() (G.debug_indent--)
710 # define indent() ((void)0)
711 # define debug_enter() ((void)0)
712 # define debug_leave() ((void)0)
716 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
719 #ifndef debug_printf_parse
720 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
723 #ifndef debug_printf_exec
724 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
727 #ifndef debug_printf_env
728 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
731 #ifndef debug_printf_jobs
732 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
733 # define DEBUG_JOBS 1
735 # define DEBUG_JOBS 0
738 #ifndef debug_printf_expand
739 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
740 # define DEBUG_EXPAND 1
742 # define DEBUG_EXPAND 0
745 #ifndef debug_printf_glob
746 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
747 # define DEBUG_GLOB 1
749 # define DEBUG_GLOB 0
752 #ifndef debug_printf_list
753 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
756 #ifndef debug_printf_subst
757 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
760 #ifndef debug_printf_clean
761 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
762 # define DEBUG_CLEAN 1
764 # define DEBUG_CLEAN 0
768 static void debug_print_strings(const char *prefix, char **vv)
771 fprintf(stderr, "%s:\n", prefix);
773 fprintf(stderr, " '%s'\n", *vv++);
776 # define debug_print_strings(prefix, vv) ((void)0)
780 /* Leak hunting. Use hush_leaktool.sh for post-processing.
783 static void *xxmalloc(int lineno, size_t size)
785 void *ptr = xmalloc((size + 0xff) & ~0xff);
786 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
789 static void *xxrealloc(int lineno, void *ptr, size_t size)
791 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
792 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
795 static char *xxstrdup(int lineno, const char *str)
797 char *ptr = xstrdup(str);
798 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
801 static void xxfree(void *ptr)
803 fdprintf(2, "free %p\n", ptr);
806 #define xmalloc(s) xxmalloc(__LINE__, s)
807 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
808 #define xstrdup(s) xxstrdup(__LINE__, s)
809 #define free(p) xxfree(p)
813 /* Syntax and runtime errors. They always abort scripts.
814 * In interactive use they usually discard unparsed and/or unexecuted commands
815 * and return to the prompt.
816 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
819 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
820 # define syntax_error(lineno, msg) syntax_error(msg)
821 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
822 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
823 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
824 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
827 static void die_if_script(unsigned lineno, const char *fmt, ...)
832 bb_error_msg("hush.c:%u", lineno);
835 bb_verror_msg(fmt, p, NULL);
837 if (!G_interactive_fd)
841 static void syntax_error(unsigned lineno, const char *msg)
844 die_if_script(lineno, "syntax error: %s", msg);
846 die_if_script(lineno, "syntax error", NULL);
849 static void syntax_error_at(unsigned lineno, const char *msg)
851 die_if_script(lineno, "syntax error at '%s'", msg);
854 static void syntax_error_unterm_str(unsigned lineno, const char *s)
856 die_if_script(lineno, "syntax error: unterminated %s", s);
859 /* It so happens that all such cases are totally fatal
860 * even if shell is interactive: EOF while looking for closing
861 * delimiter. There is nowhere to read stuff from after that,
862 * it's EOF! The only choice is to terminate.
864 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
865 static void syntax_error_unterm_ch(unsigned lineno, char ch)
867 char msg[2] = { ch, '\0' };
868 syntax_error_unterm_str(lineno, msg);
872 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
877 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
881 # undef die_if_script
883 # undef syntax_error_at
884 # undef syntax_error_unterm_ch
885 # undef syntax_error_unterm_str
886 # undef syntax_error_unexpected_ch
888 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
889 # define syntax_error(msg) syntax_error(__LINE__, msg)
890 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
891 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
892 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
893 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
897 #if ENABLE_HUSH_INTERACTIVE
898 static void cmdedit_update_prompt(void);
900 # define cmdedit_update_prompt() ((void)0)
906 /* Replace each \x with x in place, return ptr past NUL. */
907 static char *unbackslash(char *src)
909 char *dst = src = strchrnul(src, '\\');
913 if ((*dst++ = *src++) == '\0')
919 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
940 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
941 v[count1 + count2] = NULL;
944 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
948 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
950 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
951 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
954 #define add_strings_to_strings(strings, add, need_to_dup) \
955 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
958 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
959 static char **add_string_to_strings(char **strings, char *add)
964 return add_strings_to_strings(strings, v, /*dup:*/ 0);
967 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
969 char **ptr = add_string_to_strings(strings, add);
970 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
973 #define add_string_to_strings(strings, add) \
974 xx_add_string_to_strings(__LINE__, strings, add)
977 static void free_strings(char **strings)
992 /* Helpers for setting new $n and restoring them back
994 typedef struct save_arg_t {
998 smallint sv_g_malloced;
1001 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1005 sv->sv_argv0 = argv[0];
1006 sv->sv_g_argv = G.global_argv;
1007 sv->sv_g_argc = G.global_argc;
1008 sv->sv_g_malloced = G.global_args_malloced;
1010 argv[0] = G.global_argv[0]; /* retain $0 */
1011 G.global_argv = argv;
1012 G.global_args_malloced = 0;
1020 static void restore_G_args(save_arg_t *sv, char **argv)
1024 if (G.global_args_malloced) {
1025 /* someone ran "set -- arg1 arg2 ...", undo */
1027 while (*++pp) /* note: does not free $0 */
1029 free(G.global_argv);
1031 argv[0] = sv->sv_argv0;
1032 G.global_argv = sv->sv_g_argv;
1033 G.global_argc = sv->sv_g_argc;
1034 G.global_args_malloced = sv->sv_g_malloced;
1038 /* Basic theory of signal handling in shell
1039 * ========================================
1040 * This does not describe what hush does, rather, it is current understanding
1041 * what it _should_ do. If it doesn't, it's a bug.
1042 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1044 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1045 * is finished or backgrounded. It is the same in interactive and
1046 * non-interactive shells, and is the same regardless of whether
1047 * a user trap handler is installed or a shell special one is in effect.
1048 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1049 * backgrounds (i.e. stops) or kills all members of currently running
1052 * Wait builtin in interruptible by signals for which user trap is set
1053 * or by SIGINT in interactive shell.
1055 * Trap handlers will execute even within trap handlers. (right?)
1057 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1058 * except for handlers set to '' (empty string).
1060 * If job control is off, backgrounded commands ("cmd &")
1061 * have SIGINT, SIGQUIT set to SIG_IGN.
1063 * Commands which are run in command substitution ("`cmd`")
1064 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1066 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1067 * by the shell from its parent.
1069 * Signals which differ from SIG_DFL action
1070 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1073 * SIGTERM (interactive): ignore
1074 * SIGHUP (interactive):
1075 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1076 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1077 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1078 * that all pipe members are stopped. Try this in bash:
1079 * while :; do :; done - ^Z does not background it
1080 * (while :; do :; done) - ^Z backgrounds it
1081 * SIGINT (interactive): wait for last pipe, ignore the rest
1082 * of the command line, show prompt. NB: ^C does not send SIGINT
1083 * to interactive shell while shell is waiting for a pipe,
1084 * since shell is bg'ed (is not in foreground process group).
1085 * Example 1: this waits 5 sec, but does not execute ls:
1086 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1087 * Example 2: this does not wait and does not execute ls:
1088 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1089 * Example 3: this does not wait 5 sec, but executes ls:
1090 * "sleep 5; ls -l" + press ^C
1092 * (What happens to signals which are IGN on shell start?)
1093 * (What happens with signal mask on shell start?)
1095 * Implementation in hush
1096 * ======================
1097 * We use in-kernel pending signal mask to determine which signals were sent.
1098 * We block all signals which we don't want to take action immediately,
1099 * i.e. we block all signals which need to have special handling as described
1100 * above, and all signals which have traps set.
1101 * After each pipe execution, we extract any pending signals via sigtimedwait()
1104 * unsigned non_DFL_mask: a mask of such "special" signals
1105 * sigset_t blocked_set: current blocked signal set
1108 * clear bit in blocked_set unless it is also in non_DFL_mask
1109 * "trap 'cmd' SIGxxx":
1110 * set bit in blocked_set (even if 'cmd' is '')
1111 * after [v]fork, if we plan to be a shell:
1112 * unblock signals with special interactive handling
1113 * (child shell is not interactive),
1114 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1115 * after [v]fork, if we plan to exec:
1116 * POSIX says fork clears pending signal mask in child - no need to clear it.
1117 * Restore blocked signal set to one inherited by shell just prior to exec.
1119 * Note: as a result, we do not use signal handlers much. The only uses
1120 * are to count SIGCHLDs
1121 * and to restore tty pgrp on signal-induced exit.
1124 * Standard says "When a subshell is entered, traps that are not being ignored
1125 * are set to the default actions". bash interprets it so that traps which
1126 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1129 SPECIAL_INTERACTIVE_SIGS = 0
1134 SPECIAL_JOB_SIGS = 0
1142 #if ENABLE_HUSH_FAST
1143 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1146 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1152 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1153 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1154 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1155 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1157 /* Restores tty foreground process group, and exits.
1158 * May be called as signal handler for fatal signal
1159 * (will resend signal to itself, producing correct exit state)
1160 * or called directly with -EXITCODE.
1161 * We also call it if xfunc is exiting. */
1162 static void sigexit(int sig) NORETURN;
1163 static void sigexit(int sig)
1165 /* Disable all signals: job control, SIGPIPE, etc. */
1166 sigprocmask_allsigs(SIG_BLOCK);
1168 /* Careful: we can end up here after [v]fork. Do not restore
1169 * tty pgrp then, only top-level shell process does that */
1170 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1171 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1173 /* Not a signal, just exit */
1177 kill_myself_with_sig(sig); /* does not return */
1181 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1182 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1186 /* Restores tty foreground process group, and exits. */
1187 static void hush_exit(int exitcode) NORETURN;
1188 static void hush_exit(int exitcode)
1190 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1191 /* Prevent recursion:
1192 * trap "echo Hi; exit" EXIT; exit
1194 char *argv[] = { NULL, G.traps[0], NULL };
1203 sigexit(- (exitcode & 0xff));
1209 static int check_and_run_traps(int sig)
1211 static const struct timespec zero_timespec = { 0, 0 };
1212 smalluint save_rcode;
1218 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1223 if (G.traps && G.traps[sig]) {
1224 if (G.traps[sig][0]) {
1225 /* We have user-defined handler */
1226 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1227 save_rcode = G.last_exitcode;
1230 G.last_exitcode = save_rcode;
1231 } /* else: "" trap, ignoring signal */
1234 /* not a trap: special action */
1236 #if ENABLE_HUSH_FAST
1239 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1243 /* Builtin was ^C'ed, make it look prettier: */
1250 /* bash is observed to signal whole process groups,
1251 * not individual processes */
1252 for (job = G.job_list; job; job = job->next) {
1255 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1256 if (kill(- job->pgrp, SIGHUP) == 0)
1257 kill(- job->pgrp, SIGCONT);
1262 default: /* ignored: */
1263 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1271 static const char *get_cwd(int force)
1273 if (force || G.cwd == NULL) {
1274 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1275 * we must not try to free(bb_msg_unknown) */
1276 if (G.cwd == bb_msg_unknown)
1278 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1280 G.cwd = bb_msg_unknown;
1287 * Shell and environment variable support
1289 static struct variable **get_ptr_to_local_var(const char *name)
1291 struct variable **pp;
1292 struct variable *cur;
1297 while ((cur = *pp) != NULL) {
1298 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1305 static struct variable *get_local_var(const char *name)
1307 struct variable **pp = get_ptr_to_local_var(name);
1313 static const char* FAST_FUNC get_local_var_value(const char *name)
1315 struct variable **pp = get_ptr_to_local_var(name);
1317 return strchr((*pp)->varstr, '=') + 1;
1318 if (strcmp(name, "PPID") == 0)
1319 return utoa(G.root_ppid);
1320 // bash compat: UID? EUID?
1321 #if ENABLE_HUSH_RANDOM_SUPPORT
1322 if (strcmp(name, "RANDOM") == 0) {
1323 return utoa(next_random(&G.random_gen));
1329 /* str holds "NAME=VAL" and is expected to be malloced.
1330 * We take ownership of it.
1332 * 0: do not change export flag
1333 * (if creating new variable, flag will be 0)
1334 * 1: set export flag and putenv the variable
1335 * -1: clear export flag and unsetenv the variable
1336 * flg_read_only is set only when we handle -R var=val
1338 #if !BB_MMU && ENABLE_HUSH_LOCAL
1339 /* all params are used */
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, local_lvl)
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)
1346 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1347 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1348 set_local_var(str, flg_export, flg_read_only)
1350 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1352 struct variable **var_pp;
1353 struct variable *cur;
1357 eq_sign = strchr(str, '=');
1358 if (!eq_sign) { /* not expected to ever happen? */
1363 name_len = eq_sign - str + 1; /* including '=' */
1364 var_pp = &G.top_var;
1365 while ((cur = *var_pp) != NULL) {
1366 if (strncmp(cur->varstr, str, name_len) != 0) {
1367 var_pp = &cur->next;
1370 /* We found an existing var with this name */
1371 if (cur->flg_read_only) {
1375 bb_error_msg("%s: readonly variable", str);
1379 if (flg_export == -1) { // "&& cur->flg_export" ?
1380 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1385 #if ENABLE_HUSH_LOCAL
1386 if (cur->func_nest_level < local_lvl) {
1387 /* New variable is declared as local,
1388 * and existing one is global, or local
1389 * from enclosing function.
1390 * Remove and save old one: */
1391 *var_pp = cur->next;
1392 cur->next = *G.shadowed_vars_pp;
1393 *G.shadowed_vars_pp = cur;
1394 /* bash 3.2.33(1) and exported vars:
1396 * # f() { local z=a; env | grep ^z; }
1402 if (cur->flg_export)
1407 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1412 if (cur->max_len != 0) {
1413 if (cur->max_len >= strlen(str)) {
1414 /* This one is from startup env, reuse space */
1415 strcpy(cur->varstr, str);
1419 /* max_len == 0 signifies "malloced" var, which we can
1420 * (and has to) free */
1424 goto set_str_and_exp;
1427 /* Not found - create new variable struct */
1428 cur = xzalloc(sizeof(*cur));
1429 #if ENABLE_HUSH_LOCAL
1430 cur->func_nest_level = local_lvl;
1432 cur->next = *var_pp;
1438 cur->flg_read_only = flg_read_only;
1441 if (flg_export == 1)
1442 cur->flg_export = 1;
1443 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1444 cmdedit_update_prompt();
1445 if (cur->flg_export) {
1446 if (flg_export == -1) {
1447 cur->flg_export = 0;
1448 /* unsetenv was already done */
1450 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1451 return putenv(cur->varstr);
1457 /* Used at startup and after each cd */
1458 static void set_pwd_var(int exp)
1460 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1461 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1464 static int unset_local_var_len(const char *name, int name_len)
1466 struct variable *cur;
1467 struct variable **var_pp;
1470 return EXIT_SUCCESS;
1471 var_pp = &G.top_var;
1472 while ((cur = *var_pp) != NULL) {
1473 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1474 if (cur->flg_read_only) {
1475 bb_error_msg("%s: readonly variable", name);
1476 return EXIT_FAILURE;
1478 *var_pp = cur->next;
1479 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1480 bb_unsetenv(cur->varstr);
1481 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1482 cmdedit_update_prompt();
1486 return EXIT_SUCCESS;
1488 var_pp = &cur->next;
1490 return EXIT_SUCCESS;
1493 static int unset_local_var(const char *name)
1495 return unset_local_var_len(name, strlen(name));
1498 static void unset_vars(char **strings)
1506 const char *eq = strchrnul(*v, '=');
1507 unset_local_var_len(*v, (int)(eq - *v));
1513 #if ENABLE_SH_MATH_SUPPORT
1514 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1515 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1516 static char* FAST_FUNC endofname(const char *name)
1524 if (!is_in_name(*p))
1531 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1533 char *var = xasprintf("%s=%s", name, val);
1534 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1539 * Helpers for "var1=val1 var2=val2 cmd" feature
1541 static void add_vars(struct variable *var)
1543 struct variable *next;
1547 var->next = G.top_var;
1549 if (var->flg_export) {
1550 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1551 putenv(var->varstr);
1553 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1559 static struct variable *set_vars_and_save_old(char **strings)
1562 struct variable *old = NULL;
1568 struct variable *var_p;
1569 struct variable **var_pp;
1572 eq = strchr(*s, '=');
1575 var_pp = get_ptr_to_local_var(*s);
1578 /* Remove variable from global linked list */
1580 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1581 *var_pp = var_p->next;
1582 /* Add it to returned list */
1586 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1597 static int FAST_FUNC static_get(struct in_str *i)
1606 static int FAST_FUNC static_peek(struct in_str *i)
1611 #if ENABLE_HUSH_INTERACTIVE
1613 static void cmdedit_update_prompt(void)
1615 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1616 G.PS1 = get_local_var_value("PS1");
1619 G.PS2 = get_local_var_value("PS2");
1627 static const char* setup_prompt_string(int promptmode)
1629 const char *prompt_str;
1630 debug_printf("setup_prompt_string %d ", promptmode);
1631 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1632 /* Set up the prompt */
1633 if (promptmode == 0) { /* PS1 */
1635 /* bash uses $PWD value, even if it is set by user.
1636 * It uses current dir only if PWD is unset.
1637 * We always use current dir. */
1638 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1643 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1644 debug_printf("result '%s'\n", prompt_str);
1648 static void get_user_input(struct in_str *i)
1651 const char *prompt_str;
1653 prompt_str = setup_prompt_string(i->promptmode);
1654 #if ENABLE_FEATURE_EDITING
1655 /* Enable command line editing only while a command line
1656 * is actually being read */
1659 /* buglet: SIGINT will not make new prompt to appear _at once_,
1660 * only after <Enter>. (^C will work) */
1661 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1662 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1663 check_and_run_traps(0);
1664 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1665 i->eof_flag = (r < 0);
1666 if (i->eof_flag) { /* EOF/error detected */
1667 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1668 G.user_input_buf[1] = '\0';
1673 fputs(prompt_str, stdout);
1675 G.user_input_buf[0] = r = fgetc(i->file);
1676 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1677 //do we need check_and_run_traps(0)? (maybe only if stdin)
1678 } while (G.flag_SIGINT);
1679 i->eof_flag = (r == EOF);
1681 i->p = G.user_input_buf;
1684 #endif /* INTERACTIVE */
1686 /* This is the magic location that prints prompts
1687 * and gets data back from the user */
1688 static int FAST_FUNC file_get(struct in_str *i)
1692 /* If there is data waiting, eat it up */
1693 if (i->p && *i->p) {
1694 #if ENABLE_HUSH_INTERACTIVE
1698 if (i->eof_flag && !*i->p)
1700 /* note: ch is never NUL */
1702 /* need to double check i->file because we might be doing something
1703 * more complicated by now, like sourcing or substituting. */
1704 #if ENABLE_HUSH_INTERACTIVE
1705 if (G_interactive_fd && i->promptme && i->file == stdin) {
1708 } while (!*i->p); /* need non-empty line */
1709 i->promptmode = 1; /* PS2 */
1714 do ch = fgetc(i->file); while (ch == '\0');
1716 debug_printf("file_get: got '%c' %d\n", ch, ch);
1717 #if ENABLE_HUSH_INTERACTIVE
1724 /* All callers guarantee this routine will never
1725 * be used right after a newline, so prompting is not needed.
1727 static int FAST_FUNC file_peek(struct in_str *i)
1730 if (i->p && *i->p) {
1731 if (i->eof_flag && !i->p[1])
1734 /* note: ch is never NUL */
1736 do ch = fgetc(i->file); while (ch == '\0');
1737 i->eof_flag = (ch == EOF);
1738 i->peek_buf[0] = ch;
1739 i->peek_buf[1] = '\0';
1741 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1745 static void setup_file_in_str(struct in_str *i, FILE *f)
1747 i->peek = file_peek;
1749 #if ENABLE_HUSH_INTERACTIVE
1751 i->promptmode = 0; /* PS1 */
1757 static void setup_string_in_str(struct in_str *i, const char *s)
1759 i->peek = static_peek;
1760 i->get = static_get;
1761 #if ENABLE_HUSH_INTERACTIVE
1763 i->promptmode = 0; /* PS1 */
1773 #define B_CHUNK (32 * sizeof(char*))
1775 static void o_reset_to_empty_unquoted(o_string *o)
1783 static void o_free(o_string *o)
1786 memset(o, 0, sizeof(*o));
1789 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1794 static void o_grow_by(o_string *o, int len)
1796 if (o->length + len > o->maxlen) {
1797 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1798 o->data = xrealloc(o->data, 1 + o->maxlen);
1802 static void o_addchr(o_string *o, int ch)
1804 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1806 o->data[o->length] = ch;
1808 o->data[o->length] = '\0';
1811 static void o_addblock(o_string *o, const char *str, int len)
1814 memcpy(&o->data[o->length], str, len);
1816 o->data[o->length] = '\0';
1820 static void o_addstr(o_string *o, const char *str)
1822 o_addblock(o, str, strlen(str));
1824 static void nommu_addchr(o_string *o, int ch)
1830 # define nommu_addchr(o, str) ((void)0)
1833 static void o_addstr_with_NUL(o_string *o, const char *str)
1835 o_addblock(o, str, strlen(str) + 1);
1838 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1843 && (*str != '*' && *str != '?' && *str != '[')
1851 #undef HUSH_BRACE_EXP
1853 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1854 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1855 * Apparently, on unquoted $v bash still does globbing
1856 * ("v='*.txt'; echo $v" prints all .txt files),
1857 * but NOT brace expansion! Thus, there should be TWO independent
1858 * quoting mechanisms on $v expansion side: one protects
1859 * $v from brace expansion, and other additionally protects "$v" against globbing.
1860 * We have only second one.
1863 #ifdef HUSH_BRACE_EXP
1864 # define MAYBE_BRACES "{}"
1866 # define MAYBE_BRACES ""
1869 /* My analysis of quoting semantics tells me that state information
1870 * is associated with a destination, not a source.
1872 static void o_addqchr(o_string *o, int ch)
1875 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1880 o->data[o->length] = '\\';
1883 o->data[o->length] = ch;
1885 o->data[o->length] = '\0';
1888 static void o_addQchr(o_string *o, int ch)
1891 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1893 o->data[o->length] = '\\';
1897 o->data[o->length] = ch;
1899 o->data[o->length] = '\0';
1902 static void o_addQstr(o_string *o, const char *str, int len)
1905 o_addblock(o, str, len);
1911 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1912 if (ordinary_cnt > len) /* paranoia */
1914 o_addblock(o, str, ordinary_cnt);
1915 if (ordinary_cnt == len)
1917 str += ordinary_cnt;
1918 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1922 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1924 o->data[o->length] = '\\';
1928 o->data[o->length] = ch;
1930 o->data[o->length] = '\0';
1934 /* A special kind of o_string for $VAR and `cmd` expansion.
1935 * It contains char* list[] at the beginning, which is grown in 16 element
1936 * increments. Actual string data starts at the next multiple of 16 * (char*).
1937 * list[i] contains an INDEX (int!) into this string data.
1938 * It means that if list[] needs to grow, data needs to be moved higher up
1939 * but list[i]'s need not be modified.
1940 * NB: remembering how many list[i]'s you have there is crucial.
1941 * o_finalize_list() operation post-processes this structure - calculates
1942 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1944 #if DEBUG_EXPAND || DEBUG_GLOB
1945 static void debug_print_list(const char *prefix, o_string *o, int n)
1947 char **list = (char**)o->data;
1948 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1952 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1953 prefix, list, n, string_start, o->length, o->maxlen);
1956 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1957 o->data + (int)list[i] + string_start,
1958 o->data + (int)list[i] + string_start);
1962 const char *p = o->data + (int)list[n - 1] + string_start;
1964 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1968 # define debug_print_list(prefix, o, n) ((void)0)
1971 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1972 * in list[n] so that it points past last stored byte so far.
1973 * It returns n+1. */
1974 static int o_save_ptr_helper(o_string *o, int n)
1976 char **list = (char**)o->data;
1980 if (!o->has_empty_slot) {
1981 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1982 string_len = o->length - string_start;
1983 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1984 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1985 /* list[n] points to string_start, make space for 16 more pointers */
1986 o->maxlen += 0x10 * sizeof(list[0]);
1987 o->data = xrealloc(o->data, o->maxlen + 1);
1988 list = (char**)o->data;
1989 memmove(list + n + 0x10, list + n, string_len);
1990 o->length += 0x10 * sizeof(list[0]);
1992 debug_printf_list("list[%d]=%d string_start=%d\n",
1993 n, string_len, string_start);
1996 /* We have empty slot at list[n], reuse without growth */
1997 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1998 string_len = o->length - string_start;
1999 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2000 n, string_len, string_start);
2001 o->has_empty_slot = 0;
2003 list[n] = (char*)(ptrdiff_t)string_len;
2007 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2008 static int o_get_last_ptr(o_string *o, int n)
2010 char **list = (char**)o->data;
2011 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2013 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2016 #ifdef HUSH_BRACE_EXP
2017 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2018 * first, it processes even {a} (no commas), second,
2019 * I didn't manage to make it return strings when they don't match
2020 * existing files. Need to re-implement it.
2024 static int glob_needed(const char *s)
2033 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2039 /* Return pointer to next closing brace or to comma */
2040 static const char *next_brace_sub(const char *cp)
2044 while (*cp != '\0') {
2051 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2053 if (*cp++ == '{') /*}*/
2057 return *cp != '\0' ? cp : NULL;
2059 /* Recursive brace globber. Note: may garble pattern[]. */
2060 static int glob_brace(char *pattern, o_string *o, int n)
2062 char *new_pattern_buf;
2069 debug_printf_glob("glob_brace('%s')\n", pattern);
2075 if (*begin == '{') /*}*/ {
2076 /* Find the first sub-pattern and at the same time
2077 * find the rest after the closing brace */
2078 next = next_brace_sub(begin);
2080 /* An illegal expression */
2083 /*{*/ if (*next == '}') {
2084 /* "{abc}" with no commas - illegal
2085 * brace expr, disregard and skip it */
2091 if (*begin == '\\' && begin[1] != '\0')
2095 debug_printf_glob("begin:%s\n", begin);
2096 debug_printf_glob("next:%s\n", next);
2098 /* Now find the end of the whole brace expression */
2100 /*{*/ while (*rest != '}') {
2101 rest = next_brace_sub(rest);
2103 /* An illegal expression */
2106 debug_printf_glob("rest:%s\n", rest);
2108 rest_len = strlen(++rest) + 1;
2110 /* We are sure the brace expression is well-formed */
2112 /* Allocate working buffer large enough for our work */
2113 new_pattern_buf = xmalloc(strlen(pattern));
2115 /* We have a brace expression. BEGIN points to the opening {,
2116 * NEXT points past the terminator of the first element, and REST
2117 * points past the final }. We will accumulate result names from
2118 * recursive runs for each brace alternative in the buffer using
2123 /* Construct the new glob expression */
2126 mempcpy(new_pattern_buf,
2127 /* We know the prefix for all sub-patterns */
2128 pattern, begin - pattern),
2132 /* Note: glob_brace() may garble new_pattern_buf[].
2133 * That's why we re-copy prefix every time (1st memcpy above).
2135 n = glob_brace(new_pattern_buf, o, n);
2136 /*{*/ if (*next == '}') {
2137 /* We saw the last entry */
2141 next = next_brace_sub(next);
2143 free(new_pattern_buf);
2151 memset(&globdata, 0, sizeof(globdata));
2152 gr = glob(pattern, 0, NULL, &globdata);
2153 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2155 if (gr == GLOB_NOMATCH) {
2156 globfree(&globdata);
2157 /* NB: garbles parameter */
2158 unbackslash(pattern);
2159 o_addstr_with_NUL(o, pattern);
2160 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2161 return o_save_ptr_helper(o, n);
2163 if (gr == GLOB_NOSPACE)
2164 bb_error_msg_and_die(bb_msg_memory_exhausted);
2165 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2166 * but we didn't specify it. Paranoia again. */
2167 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2169 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2170 char **argv = globdata.gl_pathv;
2172 o_addstr_with_NUL(o, *argv);
2173 n = o_save_ptr_helper(o, n);
2179 globfree(&globdata);
2183 /* Performs globbing on last list[],
2184 * saving each result as a new list[].
2186 static int o_glob(o_string *o, int n)
2188 char *pattern, *copy;
2190 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2192 return o_save_ptr_helper(o, n);
2193 pattern = o->data + o_get_last_ptr(o, n);
2194 debug_printf_glob("glob pattern '%s'\n", pattern);
2195 if (!glob_needed(pattern)) {
2196 /* unbackslash last string in o in place, fix length */
2197 o->length = unbackslash(pattern) - o->data;
2198 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2199 return o_save_ptr_helper(o, n);
2202 copy = xstrdup(pattern);
2203 /* "forget" pattern in o */
2204 o->length = pattern - o->data;
2205 n = glob_brace(copy, o, n);
2208 debug_print_list("o_glob returning", o, n);
2215 static int glob_needed(const char *s)
2224 if (*s == '*' || *s == '[' || *s == '?')
2230 /* Performs globbing on last list[],
2231 * saving each result as a new list[].
2233 static int o_glob(o_string *o, int n)
2239 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2241 return o_save_ptr_helper(o, n);
2242 pattern = o->data + o_get_last_ptr(o, n);
2243 debug_printf_glob("glob pattern '%s'\n", pattern);
2244 if (!glob_needed(pattern)) {
2246 /* unbackslash last string in o in place, fix length */
2247 o->length = unbackslash(pattern) - o->data;
2248 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2249 return o_save_ptr_helper(o, n);
2252 memset(&globdata, 0, sizeof(globdata));
2253 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2254 * If we glob "*.\*" and don't find anything, we need
2255 * to fall back to using literal "*.*", but GLOB_NOCHECK
2256 * will return "*.\*"!
2258 gr = glob(pattern, 0, NULL, &globdata);
2259 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2261 if (gr == GLOB_NOMATCH) {
2262 globfree(&globdata);
2265 if (gr == GLOB_NOSPACE)
2266 bb_error_msg_and_die(bb_msg_memory_exhausted);
2267 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2268 * but we didn't specify it. Paranoia again. */
2269 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2271 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2272 char **argv = globdata.gl_pathv;
2273 /* "forget" pattern in o */
2274 o->length = pattern - o->data;
2276 o_addstr_with_NUL(o, *argv);
2277 n = o_save_ptr_helper(o, n);
2283 globfree(&globdata);
2285 debug_print_list("o_glob returning", o, n);
2291 /* If o->o_glob == 1, glob the string so far remembered.
2292 * Otherwise, just finish current list[] and start new */
2293 static int o_save_ptr(o_string *o, int n)
2295 if (o->o_glob) { /* if globbing is requested */
2296 /* If o->has_empty_slot, list[n] was already globbed
2297 * (if it was requested back then when it was filled)
2298 * so don't do that again! */
2299 if (!o->has_empty_slot)
2300 return o_glob(o, n); /* o_save_ptr_helper is inside */
2302 return o_save_ptr_helper(o, n);
2305 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2306 static char **o_finalize_list(o_string *o, int n)
2311 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2313 debug_print_list("finalized", o, n);
2314 debug_printf_expand("finalized n:%d\n", n);
2315 list = (char**)o->data;
2316 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2320 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2326 /* Expansion can recurse */
2327 #if ENABLE_HUSH_TICK
2328 static int process_command_subs(o_string *dest, const char *s);
2330 static char *expand_string_to_string(const char *str);
2332 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2333 parse_stream_dquoted(dest, input, dquote_end)
2335 static int parse_stream_dquoted(o_string *as_string,
2337 struct in_str *input,
2340 /* expand_strvec_to_strvec() takes a list of strings, expands
2341 * all variable references within and returns a pointer to
2342 * a list of expanded strings, possibly with larger number
2343 * of strings. (Think VAR="a b"; echo $VAR).
2344 * This new list is allocated as a single malloc block.
2345 * NULL-terminated list of char* pointers is at the beginning of it,
2346 * followed by strings themself.
2347 * Caller can deallocate entire list by single free(list). */
2349 /* Store given string, finalizing the word and starting new one whenever
2350 * we encounter IFS char(s). This is used for expanding variable values.
2351 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2352 static int expand_on_ifs(o_string *output, int n, const char *str)
2355 int word_len = strcspn(str, G.ifs);
2357 if (output->o_escape || !output->o_glob)
2358 o_addQstr(output, str, word_len);
2359 else /* protect backslashes against globbing up :) */
2360 o_addblock_duplicate_backslash(output, str, word_len);
2363 if (!*str) /* EOL - do not finalize word */
2365 o_addchr(output, '\0');
2366 debug_print_list("expand_on_ifs", output, n);
2367 n = o_save_ptr(output, n);
2368 str += strspn(str, G.ifs); /* skip ifs chars */
2370 debug_print_list("expand_on_ifs[1]", output, n);
2374 /* Helper to expand $((...)) and heredoc body. These act as if
2375 * they are in double quotes, with the exception that they are not :).
2376 * Just the rules are similar: "expand only $var and `cmd`"
2378 * Returns malloced string.
2379 * As an optimization, we return NULL if expansion is not needed.
2381 static char *expand_pseudo_dquoted(const char *str)
2384 struct in_str input;
2385 o_string dest = NULL_O_STRING;
2387 if (strchr(str, '$') == NULL
2388 #if ENABLE_HUSH_TICK
2389 && strchr(str, '`') == NULL
2395 /* We need to expand. Example:
2396 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2398 setup_string_in_str(&input, str);
2399 parse_stream_dquoted(NULL, &dest, &input, EOF);
2400 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2401 exp_str = expand_string_to_string(dest.data);
2402 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2403 o_free_unsafe(&dest);
2407 /* Expand all variable references in given string, adding words to list[]
2408 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2409 * to be filled). This routine is extremely tricky: has to deal with
2410 * variables/parameters with whitespace, $* and $@, and constructs like
2411 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2412 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2414 /* or_mask is either 0 (normal case) or 0x80 -
2415 * expansion of right-hand side of assignment == 1-element expand.
2416 * It will also do no globbing, and thus we must not backslash-quote!
2423 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2424 debug_print_list("expand_vars_to_list", output, n);
2425 n = o_save_ptr(output, n);
2426 debug_print_list("expand_vars_to_list[0]", output, n);
2428 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2431 char *dyn_val = NULL;
2432 const char *val = NULL;
2433 #if ENABLE_HUSH_TICK
2434 o_string subst_result = NULL_O_STRING;
2436 #if ENABLE_SH_MATH_SUPPORT
2437 char arith_buf[sizeof(arith_t)*3 + 2];
2439 o_addblock(output, arg, p - arg);
2440 debug_print_list("expand_vars_to_list[1]", output, n);
2442 p = strchr(p, SPECIAL_VAR_SYMBOL);
2444 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2445 /* "$@" is special. Even if quoted, it can still
2446 * expand to nothing (not even an empty string) */
2447 if ((first_ch & 0x7f) != '@')
2448 ored_ch |= first_ch;
2450 switch (first_ch & 0x7f) {
2451 /* Highest bit in first_ch indicates that var is double-quoted */
2453 val = utoa(G.root_pid);
2455 case '!': /* bg pid */
2456 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2458 case '?': /* exitcode */
2459 val = utoa(G.last_exitcode);
2461 case '#': /* argc */
2462 if (arg[1] != SPECIAL_VAR_SYMBOL)
2463 /* actually, it's a ${#var} */
2465 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2470 if (!G.global_argv[i])
2472 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2473 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2474 smallint sv = output->o_escape;
2475 /* unquoted var's contents should be globbed, so don't escape */
2476 output->o_escape = 0;
2477 while (G.global_argv[i]) {
2478 n = expand_on_ifs(output, n, G.global_argv[i]);
2479 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2480 if (G.global_argv[i++][0] && G.global_argv[i]) {
2481 /* this argv[] is not empty and not last:
2482 * put terminating NUL, start new word */
2483 o_addchr(output, '\0');
2484 debug_print_list("expand_vars_to_list[2]", output, n);
2485 n = o_save_ptr(output, n);
2486 debug_print_list("expand_vars_to_list[3]", output, n);
2489 output->o_escape = sv;
2491 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2492 * and in this case should treat it like '$*' - see 'else...' below */
2493 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2495 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2496 if (++i >= G.global_argc)
2498 o_addchr(output, '\0');
2499 debug_print_list("expand_vars_to_list[4]", output, n);
2500 n = o_save_ptr(output, n);
2502 } else { /* quoted $*: add as one word */
2504 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2505 if (!G.global_argv[++i])
2508 o_addchr(output, G.ifs[0]);
2512 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2513 /* "Empty variable", used to make "" etc to not disappear */
2517 #if ENABLE_HUSH_TICK
2518 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2521 /* Can't just stuff it into output o_string,
2522 * expanded result may need to be globbed
2523 * and $IFS-splitted */
2524 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2525 G.last_exitcode = process_command_subs(&subst_result, arg);
2526 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2527 val = subst_result.data;
2530 #if ENABLE_SH_MATH_SUPPORT
2531 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2532 arith_eval_hooks_t hooks;
2537 arg++; /* skip '+' */
2538 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2539 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2541 exp_str = expand_pseudo_dquoted(arg);
2542 hooks.lookupvar = get_local_var_value;
2543 hooks.setvar = set_local_var_from_halves;
2544 hooks.endofname = endofname;
2545 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2549 const char *msg = "error in arithmetic";
2552 msg = "exponent less than 0";
2555 msg = "divide by 0";
2558 msg = "expression recursion loop detected";
2563 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2564 sprintf(arith_buf, arith_t_fmt, res);
2569 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2574 char exp_save = exp_save; /* for compiler */
2575 char *exp_saveptr = exp_saveptr; /* points to expansion operator */
2576 char *exp_word = exp_word; /* for compiler */
2579 arg[0] = first_ch & 0x7f;
2581 /* prepare for expansions */
2584 if (var[0] == '#') {
2585 /* handle length expansion ${#var} */
2589 /* maybe handle parameter expansion */
2590 exp_saveptr = var + strcspn(var, ":-=+?%#");
2591 exp_save = *exp_saveptr;
2593 exp_word = exp_saveptr;
2594 if (exp_save == ':')
2596 exp_op = *exp_word++;
2597 *exp_saveptr = '\0';
2601 /* lookup the variable in question */
2602 if (isdigit(var[0])) {
2603 /* handle_dollar() should have vetted var for us */
2605 if (i < G.global_argc)
2606 val = G.global_argv[i];
2607 /* else val remains NULL: $N with too big N */
2609 val = get_local_var_value(var);
2611 /* handle any expansions */
2613 debug_printf_expand("expand: length of '%s' = ", val);
2614 val = utoa(val ? strlen(val) : 0);
2615 debug_printf_expand("%s\n", val);
2616 } else if (exp_op) {
2617 if (exp_op == '%' || exp_op == '#') {
2619 /* we need to do a pattern match */
2622 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2623 if (exp_op == *exp_word) /* ## or %% */
2625 val = dyn_val = xstrdup(val);
2626 loc = scan(dyn_val, exp_word, match_at_left);
2627 if (match_at_left) /* # or ## */
2629 else if (loc) /* % or %% and match was found */
2632 } else { /* one of :-=+? */
2633 //TODO: handle ${VAR:N[:M]} here. N, M can be expressions similar to $((EXPR)): 2+2, 2+var etc
2634 /* we need to do an expansion */
2635 int exp_test = (!val || ((exp_save == ':') && !val[0]));
2637 exp_test = !exp_test;
2638 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2639 (exp_save == ':') ? "true" : "false", exp_test);
2641 if (exp_op == '?') {
2642 //TODO: how interactive bash aborts expansion mid-command?
2643 /* ${var?[error_msg_if_unset]} */
2644 /* ${var:?[error_msg_if_unset_or_null]} */
2645 /* mimic bash message */
2646 die_if_script("%s: %s",
2648 exp_word[0] ? exp_word : "parameter null or not set"
2654 if (exp_op == '=') {
2655 /* ${var=[word]} or ${var:=[word]} */
2656 if (isdigit(var[0]) || var[0] == '#') {
2657 /* mimic bash message */
2658 die_if_script("$%s: cannot assign in this way", var);
2661 char *new_var = xasprintf("%s=%s", var, val);
2662 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2668 *exp_saveptr = exp_save;
2672 #if ENABLE_HUSH_TICK
2675 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2676 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2678 /* unquoted var's contents should be globbed, so don't escape */
2679 smallint sv = output->o_escape;
2680 output->o_escape = 0;
2681 n = expand_on_ifs(output, n, val);
2683 output->o_escape = sv;
2685 } else { /* quoted $VAR, val will be appended below */
2686 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2689 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2692 o_addQstr(output, val, strlen(val));
2695 /* Do the check to avoid writing to a const string */
2696 if (*p != SPECIAL_VAR_SYMBOL)
2697 *p = SPECIAL_VAR_SYMBOL;
2699 #if ENABLE_HUSH_TICK
2700 o_free(&subst_result);
2703 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2706 debug_print_list("expand_vars_to_list[a]", output, n);
2707 /* this part is literal, and it was already pre-quoted
2708 * if needed (much earlier), do not use o_addQstr here! */
2709 o_addstr_with_NUL(output, arg);
2710 debug_print_list("expand_vars_to_list[b]", output, n);
2711 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2712 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2715 /* allow to reuse list[n] later without re-growth */
2716 output->has_empty_slot = 1;
2718 o_addchr(output, '\0');
2723 static char **expand_variables(char **argv, int or_mask)
2728 o_string output = NULL_O_STRING;
2730 if (or_mask & 0x100) {
2731 output.o_escape = 1; /* protect against globbing for "$var" */
2732 /* (unquoted $var will temporarily switch it off) */
2739 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2742 debug_print_list("expand_variables", &output, n);
2744 /* output.data (malloced in one block) gets returned in "list" */
2745 list = o_finalize_list(&output, n);
2746 debug_print_strings("expand_variables[1]", list);
2750 static char **expand_strvec_to_strvec(char **argv)
2752 return expand_variables(argv, 0x100);
2755 #if ENABLE_HUSH_BASH_COMPAT
2756 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2758 return expand_variables(argv, 0x80);
2762 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2763 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2768 o_string output = NULL_O_STRING;
2773 int is_var = is_well_formed_var_name(*v, '=');
2774 /* is_var * 0x80: singleword expansion for vars */
2775 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2777 /* Subtle! expand_vars_to_list did not glob last word yet.
2778 * It does this only when fed with further data.
2779 * Therefore we set globbing flags AFTER it, not before:
2782 /* if it is not recognizably abc=...; then: */
2783 output.o_escape = !is_var; /* protect against globbing for "$var" */
2784 /* (unquoted $var will temporarily switch it off) */
2785 output.o_glob = !is_var; /* and indeed do globbing */
2788 debug_print_list("expand_cond", &output, n);
2790 /* output.data (malloced in one block) gets returned in "list" */
2791 list = o_finalize_list(&output, n);
2792 debug_print_strings("expand_cond[1]", list);
2797 /* Used for expansion of right hand of assignments */
2798 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2800 static char *expand_string_to_string(const char *str)
2802 char *argv[2], **list;
2804 argv[0] = (char*)str;
2806 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2808 if (!list[0] || list[1])
2809 bb_error_msg_and_die("BUG in varexp2");
2810 /* actually, just move string 2*sizeof(char*) bytes back */
2811 overlapping_strcpy((char*)list, list[0]);
2812 unbackslash((char*)list);
2813 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2817 /* Used for "eval" builtin */
2818 static char* expand_strvec_to_string(char **argv)
2822 list = expand_variables(argv, 0x80);
2823 /* Convert all NULs to spaces */
2828 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2829 bb_error_msg_and_die("BUG in varexp3");
2830 /* bash uses ' ' regardless of $IFS contents */
2835 overlapping_strcpy((char*)list, list[0]);
2836 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2840 static char **expand_assignments(char **argv, int count)
2844 /* Expand assignments into one string each */
2845 for (i = 0; i < count; i++) {
2846 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2854 void re_execute_shell(char ***to_free, const char *s,
2855 char *g_argv0, char **g_argv,
2856 char **builtin_argv) NORETURN;
2858 static void reset_traps_to_defaults(void)
2860 /* This function is always called in a child shell
2861 * after fork (not vfork, NOMMU doesn't use this function).
2866 /* Child shells are not interactive.
2867 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2868 * Testcase: (while :; do :; done) + ^Z should background.
2869 * Same goes for SIGTERM, SIGHUP, SIGINT.
2871 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2872 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2874 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2875 * Stupid. It can be done with *single* &= op, but we can't use
2876 * the fact that G.blocked_set is implemented as a bitmask
2878 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2882 /* Careful. Only if no trap or trap is not "" */
2883 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2884 sigdelset(&G.blocked_set, sig);
2891 /* Our homegrown sig mask is saner to work with :) */
2892 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2894 /* Resetting all traps to default except empty ones */
2895 mask = G.non_DFL_mask;
2896 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2897 if (!G.traps[sig] || !G.traps[sig][0])
2900 G.traps[sig] = NULL;
2901 /* There is no signal for 0 (EXIT) */
2904 /* There was a trap handler, we just removed it.
2905 * But if sig still has non-DFL handling,
2906 * we should not unblock the sig. */
2909 sigdelset(&G.blocked_set, sig);
2911 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2916 static void re_execute_shell(char ***to_free, const char *s,
2917 char *g_argv0, char **g_argv,
2918 char **builtin_argv) NORETURN;
2919 static void re_execute_shell(char ***to_free, const char *s,
2920 char *g_argv0, char **g_argv,
2921 char **builtin_argv)
2923 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
2924 /* delims + 2 * (number of bytes in printed hex numbers) */
2925 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
2926 char *heredoc_argv[4];
2927 struct variable *cur;
2928 # if ENABLE_HUSH_FUNCTIONS
2929 struct function *funcp;
2933 unsigned long long empty_trap_mask;
2935 if (!g_argv0) { /* heredoc */
2936 argv = heredoc_argv;
2937 argv[0] = (char *) G.argv0_for_re_execing;
2938 argv[1] = (char *) "-<";
2939 argv[2] = (char *) s;
2941 pp = &argv[3]; /* used as pointer to empty environment */
2947 if (pp) while (*pp++)
2950 empty_trap_mask = 0;
2953 for (sig = 1; sig < NSIG; sig++) {
2954 if (G.traps[sig] && !G.traps[sig][0])
2955 empty_trap_mask |= 1LL << sig;
2959 sprintf(param_buf, NOMMU_HACK_FMT
2960 , (unsigned) G.root_pid
2961 , (unsigned) G.root_ppid
2962 , (unsigned) G.last_bg_pid
2963 , (unsigned) G.last_exitcode
2966 IF_HUSH_LOOPS(, G.depth_of_loop)
2968 #undef NOMMU_HACK_FMT
2969 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
2970 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2973 for (cur = G.top_var; cur; cur = cur->next) {
2974 if (!cur->flg_export || cur->flg_read_only)
2977 # if ENABLE_HUSH_FUNCTIONS
2978 for (funcp = G.top_func; funcp; funcp = funcp->next)
2984 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2985 *pp++ = (char *) G.argv0_for_re_execing;
2987 for (cur = G.top_var; cur; cur = cur->next) {
2988 if (cur->varstr == hush_version_str)
2990 if (cur->flg_read_only) {
2991 *pp++ = (char *) "-R";
2992 *pp++ = cur->varstr;
2993 } else if (!cur->flg_export) {
2994 *pp++ = (char *) "-V";
2995 *pp++ = cur->varstr;
2998 # if ENABLE_HUSH_FUNCTIONS
2999 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3000 *pp++ = (char *) "-F";
3001 *pp++ = funcp->name;
3002 *pp++ = funcp->body_as_string;
3005 /* We can pass activated traps here. Say, -Tnn:trap_string
3007 * However, POSIX says that subshells reset signals with traps
3009 * I tested bash-3.2 and it not only does that with true subshells
3010 * of the form ( list ), but with any forked children shells.
3011 * I set trap "echo W" WINCH; and then tried:
3013 * { echo 1; sleep 20; echo 2; } &
3014 * while true; do echo 1; sleep 20; echo 2; break; done &
3015 * true | { echo 1; sleep 20; echo 2; } | cat
3017 * In all these cases sending SIGWINCH to the child shell
3018 * did not run the trap. If I add trap "echo V" WINCH;
3019 * _inside_ group (just before echo 1), it works.
3021 * I conclude it means we don't need to pass active traps here.
3022 * Even if we would use signal handlers instead of signal masking
3023 * in order to implement trap handling,
3024 * exec syscall below resets signals to SIG_DFL for us.
3026 *pp++ = (char *) "-c";
3029 while (*++builtin_argv)
3030 *pp++ = *builtin_argv;
3031 *pp++ = (char *) "";
3036 /* *pp = NULL; - is already there */
3040 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3041 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3042 execve(bb_busybox_exec_path, argv, pp);
3043 /* Fallback. Useful for init=/bin/hush usage etc */
3044 if (argv[0][0] == '/')
3045 execve(argv[0], argv, pp);
3046 xfunc_error_retval = 127;
3047 bb_error_msg_and_die("can't re-execute the shell");
3049 #endif /* !BB_MMU */
3052 static void setup_heredoc(struct redir_struct *redir)
3054 struct fd_pair pair;
3057 /* the _body_ of heredoc (misleading field name) */
3058 const char *heredoc = redir->rd_filename;
3065 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3066 expanded = expand_pseudo_dquoted(heredoc);
3070 len = strlen(heredoc);
3072 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3074 xmove_fd(pair.rd, redir->rd_fd);
3076 /* Try writing without forking. Newer kernels have
3077 * dynamically growing pipes. Must use non-blocking write! */
3080 written = write(pair.wr, heredoc, len);
3091 ndelay_off(pair.wr);
3093 /* Okay, pipe buffer was not big enough */
3094 /* Note: we must not create a stray child (bastard? :)
3095 * for the unsuspecting parent process. Child creates a grandchild
3096 * and exits before parent execs the process which consumes heredoc
3097 * (that exec happens after we return from this function) */
3103 bb_perror_msg_and_die("vfork");
3106 disable_restore_tty_pgrp_on_exit();
3107 pid = BB_MMU ? fork() : vfork();
3109 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3113 close(redir->rd_fd); /* read side of the pipe */
3115 full_write(pair.wr, heredoc, len); /* may loop or block */
3118 /* Delegate blocking writes to another process */
3119 xmove_fd(pair.wr, STDOUT_FILENO);
3120 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3124 #if ENABLE_HUSH_FAST
3126 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3128 enable_restore_tty_pgrp_on_exit();
3134 wait(NULL); /* wait till child has died */
3137 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3138 * and stderr if they are redirected. */
3139 static int setup_redirects(struct command *prog, int squirrel[])
3142 struct redir_struct *redir;
3144 for (redir = prog->redirects; redir; redir = redir->next) {
3145 if (redir->rd_type == REDIRECT_HEREDOC2) {
3146 /* rd_fd<<HERE case */
3147 if (squirrel && redir->rd_fd < 3
3148 && squirrel[redir->rd_fd] < 0
3150 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3152 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3154 debug_printf_parse("set heredoc '%s'\n",
3155 redir->rd_filename);
3156 setup_heredoc(redir);
3160 if (redir->rd_dup == REDIRFD_TO_FILE) {
3161 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3163 if (redir->rd_filename == NULL) {
3164 /* Something went wrong in the parse.
3165 * Pretend it didn't happen */
3166 bb_error_msg("bug in redirect parse");
3169 mode = redir_table[redir->rd_type].mode;
3170 p = expand_string_to_string(redir->rd_filename);
3171 openfd = open_or_warn(p, mode);
3174 /* this could get lost if stderr has been redirected, but
3175 * bash and ash both lose it as well (though zsh doesn't!) */
3176 //what the above comment tries to say?
3180 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3181 openfd = redir->rd_dup;
3184 if (openfd != redir->rd_fd) {
3185 if (squirrel && redir->rd_fd < 3
3186 && squirrel[redir->rd_fd] < 0
3188 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3190 if (openfd == REDIRFD_CLOSE) {
3191 /* "n>-" means "close me" */
3192 close(redir->rd_fd);
3194 xdup2(openfd, redir->rd_fd);
3195 if (redir->rd_dup == REDIRFD_TO_FILE)
3203 static void restore_redirects(int squirrel[])
3206 for (i = 0; i < 3; i++) {
3209 /* We simply die on error */
3216 static void free_pipe_list(struct pipe *head);
3218 /* Return code is the exit status of the pipe */
3219 static void free_pipe(struct pipe *pi)
3222 struct command *command;
3223 struct redir_struct *r, *rnext;
3226 if (pi->stopped_cmds > 0) /* why? */
3228 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3229 for (i = 0; i < pi->num_cmds; i++) {
3230 command = &pi->cmds[i];
3231 debug_printf_clean(" command %d:\n", i);
3232 if (command->argv) {
3233 for (a = 0, p = command->argv; *p; a++, p++) {
3234 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3236 free_strings(command->argv);
3237 command->argv = NULL;
3239 /* not "else if": on syntax error, we may have both! */
3240 if (command->group) {
3241 debug_printf_clean(" begin group (cmd_type:%d)\n",
3243 free_pipe_list(command->group);
3244 debug_printf_clean(" end group\n");
3245 command->group = NULL;
3247 /* else is crucial here.
3248 * If group != NULL, child_func is meaningless */
3249 #if ENABLE_HUSH_FUNCTIONS
3250 else if (command->child_func) {
3251 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3252 command->child_func->parent_cmd = NULL;
3256 free(command->group_as_string);
3257 command->group_as_string = NULL;
3259 for (r = command->redirects; r; r = rnext) {
3260 debug_printf_clean(" redirect %d%s",
3261 r->rd_fd, redir_table[r->rd_type].descrip);
3262 /* guard against the case >$FOO, where foo is unset or blank */
3263 if (r->rd_filename) {
3264 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3265 free(r->rd_filename);
3266 r->rd_filename = NULL;
3268 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3272 command->redirects = NULL;
3274 free(pi->cmds); /* children are an array, they get freed all at once */
3282 static void free_pipe_list(struct pipe *head)
3284 struct pipe *pi, *next;
3286 for (pi = head; pi; pi = next) {
3288 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3291 debug_printf_clean("pipe followup code %d\n", pi->followup);
3293 /*pi->next = NULL;*/
3299 static int run_list(struct pipe *pi);
3301 #define parse_stream(pstring, input, end_trigger) \
3302 parse_stream(input, end_trigger)
3304 static struct pipe *parse_stream(char **pstring,
3305 struct in_str *input,
3307 static void parse_and_run_string(const char *s);
3310 static char *find_in_path(const char *arg)
3313 const char *PATH = get_local_var_value("PATH");
3319 const char *end = strchrnul(PATH, ':');
3320 int sz = end - PATH; /* must be int! */
3324 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3326 /* We have xxx::yyyy in $PATH,
3327 * it means "use current dir" */
3330 if (access(ret, F_OK) == 0)
3343 static const struct built_in_command* find_builtin_helper(const char *name,
3344 const struct built_in_command *x,
3345 const struct built_in_command *end)
3348 if (strcmp(name, x->b_cmd) != 0) {
3352 debug_printf_exec("found builtin '%s'\n", name);
3357 static const struct built_in_command* find_builtin1(const char *name)
3359 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3361 static const struct built_in_command* find_builtin(const char *name)
3363 const struct built_in_command *x = find_builtin1(name);
3366 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3369 #if ENABLE_HUSH_FUNCTIONS
3370 static struct function **find_function_slot(const char *name)
3372 struct function **funcpp = &G.top_func;
3374 if (strcmp(name, (*funcpp)->name) == 0) {
3377 funcpp = &(*funcpp)->next;
3382 static const struct function *find_function(const char *name)
3384 const struct function *funcp = *find_function_slot(name);
3386 debug_printf_exec("found function '%s'\n", name);
3390 /* Note: takes ownership on name ptr */
3391 static struct function *new_function(char *name)
3393 struct function **funcpp = find_function_slot(name);
3394 struct function *funcp = *funcpp;
3396 if (funcp != NULL) {
3397 struct command *cmd = funcp->parent_cmd;
3398 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3400 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3402 /* Note: if !funcp->body, do not free body_as_string!
3403 * This is a special case of "-F name body" function:
3404 * body_as_string was not malloced! */
3406 free_pipe_list(funcp->body);
3408 free(funcp->body_as_string);
3412 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3413 cmd->argv[0] = funcp->name;
3414 cmd->group = funcp->body;
3416 cmd->group_as_string = funcp->body_as_string;
3420 debug_printf_exec("remembering new function '%s'\n", name);
3421 funcp = *funcpp = xzalloc(sizeof(*funcp));
3422 /*funcp->next = NULL;*/
3429 static void unset_func(const char *name)
3431 struct function **funcpp = find_function_slot(name);
3432 struct function *funcp = *funcpp;
3434 if (funcp != NULL) {
3435 debug_printf_exec("freeing function '%s'\n", funcp->name);
3436 *funcpp = funcp->next;
3437 /* funcp is unlinked now, deleting it.
3438 * Note: if !funcp->body, the function was created by
3439 * "-F name body", do not free ->body_as_string
3440 * and ->name as they were not malloced. */
3442 free_pipe_list(funcp->body);
3445 free(funcp->body_as_string);
3453 #define exec_function(to_free, funcp, argv) \
3454 exec_function(funcp, argv)
3456 static void exec_function(char ***to_free,
3457 const struct function *funcp,
3458 char **argv) NORETURN;
3459 static void exec_function(char ***to_free,
3460 const struct function *funcp,
3466 argv[0] = G.global_argv[0];
3467 G.global_argv = argv;
3471 /* On MMU, funcp->body is always non-NULL */
3472 n = run_list(funcp->body);
3476 re_execute_shell(to_free,
3477 funcp->body_as_string,
3484 static int run_function(const struct function *funcp, char **argv)
3490 save_and_replace_G_args(&sv, argv);
3492 /* "we are in function, ok to use return" */
3493 sv_flg = G.flag_return_in_progress;
3494 G.flag_return_in_progress = -1;
3495 # if ENABLE_HUSH_LOCAL
3496 G.func_nest_level++;
3499 /* On MMU, funcp->body is always non-NULL */
3502 /* Function defined by -F */
3503 parse_and_run_string(funcp->body_as_string);
3504 rc = G.last_exitcode;
3508 rc = run_list(funcp->body);
3511 # if ENABLE_HUSH_LOCAL
3513 struct variable *var;
3514 struct variable **var_pp;
3516 var_pp = &G.top_var;
3517 while ((var = *var_pp) != NULL) {
3518 if (var->func_nest_level < G.func_nest_level) {
3519 var_pp = &var->next;
3523 if (var->flg_export)
3524 bb_unsetenv(var->varstr);
3525 /* Remove from global list */
3526 *var_pp = var->next;
3532 G.func_nest_level--;
3535 G.flag_return_in_progress = sv_flg;
3537 restore_G_args(&sv, argv);
3541 #endif /* ENABLE_HUSH_FUNCTIONS */
3545 #define exec_builtin(to_free, x, argv) \
3546 exec_builtin(x, argv)
3548 #define exec_builtin(to_free, x, argv) \
3549 exec_builtin(to_free, argv)
3551 static void exec_builtin(char ***to_free,
3552 const struct built_in_command *x,
3553 char **argv) NORETURN;
3554 static void exec_builtin(char ***to_free,
3555 const struct built_in_command *x,
3559 int rcode = x->b_function(argv);
3563 /* On NOMMU, we must never block!
3564 * Example: { sleep 99 | read line; } & echo Ok
3566 re_execute_shell(to_free,
3575 static void execvp_or_die(char **argv) NORETURN;
3576 static void execvp_or_die(char **argv)
3578 debug_printf_exec("execing '%s'\n", argv[0]);
3579 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3580 execvp(argv[0], argv);
3581 bb_perror_msg("can't execute '%s'", argv[0]);
3582 _exit(127); /* bash compat */
3586 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3587 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3588 #define pseudo_exec(nommu_save, command, argv_expanded) \
3589 pseudo_exec(command, argv_expanded)
3592 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3594 * Don't exit() here. If you don't exec, use _exit instead.
3595 * The at_exit handlers apparently confuse the calling process,
3596 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3597 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3598 char **argv, int assignment_cnt,
3599 char **argv_expanded) NORETURN;
3600 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3601 char **argv, int assignment_cnt,
3602 char **argv_expanded)
3606 /* Case when we are here: ... | var=val | ... */
3607 if (!argv[assignment_cnt])
3608 _exit(EXIT_SUCCESS);
3610 new_env = expand_assignments(argv, assignment_cnt);
3612 set_vars_and_save_old(new_env);
3613 free(new_env); /* optional */
3614 /* we can also destroy set_vars_and_save_old's return value,
3617 nommu_save->new_env = new_env;
3618 nommu_save->old_vars = set_vars_and_save_old(new_env);
3620 if (argv_expanded) {
3621 argv = argv_expanded;
3623 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3625 nommu_save->argv = argv;
3629 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3630 if (strchr(argv[0], '/') != NULL)
3634 /* Check if the command matches any of the builtins.
3635 * Depending on context, this might be redundant. But it's
3636 * easier to waste a few CPU cycles than it is to figure out
3637 * if this is one of those cases.
3640 /* On NOMMU, it is more expensive to re-execute shell
3641 * just in order to run echo or test builtin.
3642 * It's better to skip it here and run corresponding
3643 * non-builtin later. */
3644 const struct built_in_command *x;
3645 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3647 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3650 #if ENABLE_HUSH_FUNCTIONS
3651 /* Check if the command matches any functions */
3653 const struct function *funcp = find_function(argv[0]);
3655 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3660 #if ENABLE_FEATURE_SH_STANDALONE
3661 /* Check if the command matches any busybox applets */
3663 int a = find_applet_by_name(argv[0]);
3665 # if BB_MMU /* see above why on NOMMU it is not allowed */
3666 if (APPLET_IS_NOEXEC(a)) {
3667 debug_printf_exec("running applet '%s'\n", argv[0]);
3668 run_applet_no_and_exit(a, argv);
3671 /* Re-exec ourselves */
3672 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3673 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3674 execv(bb_busybox_exec_path, argv);
3675 /* If they called chroot or otherwise made the binary no longer
3676 * executable, fall through */
3681 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3684 execvp_or_die(argv);
3687 /* Called after [v]fork() in run_pipe
3689 static void pseudo_exec(nommu_save_t *nommu_save,
3690 struct command *command,
3691 char **argv_expanded) NORETURN;
3692 static void pseudo_exec(nommu_save_t *nommu_save,
3693 struct command *command,
3694 char **argv_expanded)
3696 if (command->argv) {
3697 pseudo_exec_argv(nommu_save, command->argv,
3698 command->assignment_cnt, argv_expanded);
3701 if (command->group) {
3702 /* Cases when we are here:
3705 * ... | ( list ) | ...
3706 * ... | { list } | ...
3710 debug_printf_exec("pseudo_exec: run_list\n");
3711 reset_traps_to_defaults();
3712 rcode = run_list(command->group);
3713 /* OK to leak memory by not calling free_pipe_list,
3714 * since this process is about to exit */
3717 re_execute_shell(&nommu_save->argv_from_re_execing,
3718 command->group_as_string,
3725 /* Case when we are here: ... | >file */
3726 debug_printf_exec("pseudo_exec'ed null command\n");
3727 _exit(EXIT_SUCCESS);
3731 static const char *get_cmdtext(struct pipe *pi)
3737 /* This is subtle. ->cmdtext is created only on first backgrounding.
3738 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3739 * On subsequent bg argv is trashed, but we won't use it */
3742 argv = pi->cmds[0].argv;
3743 if (!argv || !argv[0]) {
3744 pi->cmdtext = xzalloc(1);
3750 len += strlen(*argv) + 1;
3754 argv = pi->cmds[0].argv;
3756 len = strlen(*argv);
3757 memcpy(p, *argv, len);
3765 static void insert_bg_job(struct pipe *pi)
3767 struct pipe *job, **jobp;
3770 /* Linear search for the ID of the job to use */
3772 for (job = G.job_list; job; job = job->next)
3773 if (job->jobid >= pi->jobid)
3774 pi->jobid = job->jobid + 1;
3776 /* Add job to the list of running jobs */
3778 while ((job = *jobp) != NULL)
3780 job = *jobp = xmalloc(sizeof(*job));
3782 *job = *pi; /* physical copy */
3784 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3785 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3786 for (i = 0; i < pi->num_cmds; i++) {
3787 job->cmds[i].pid = pi->cmds[i].pid;
3788 /* all other fields are not used and stay zero */
3790 job->cmdtext = xstrdup(get_cmdtext(pi));
3792 if (G_interactive_fd)
3793 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3794 /* Last command's pid goes to $! */
3795 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3796 G.last_jobid = job->jobid;
3799 static void remove_bg_job(struct pipe *pi)
3801 struct pipe *prev_pipe;
3803 if (pi == G.job_list) {
3804 G.job_list = pi->next;
3806 prev_pipe = G.job_list;
3807 while (prev_pipe->next != pi)
3808 prev_pipe = prev_pipe->next;
3809 prev_pipe->next = pi->next;
3812 G.last_jobid = G.job_list->jobid;
3817 /* Remove a backgrounded job */
3818 static void delete_finished_bg_job(struct pipe *pi)
3821 pi->stopped_cmds = 0;
3827 /* Check to see if any processes have exited -- if they
3828 * have, figure out why and see if a job has completed */
3829 static int checkjobs(struct pipe* fg_pipe)
3839 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3841 attributes = WUNTRACED;
3842 if (fg_pipe == NULL)
3843 attributes |= WNOHANG;
3846 #if ENABLE_HUSH_FAST
3847 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3848 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3849 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3850 /* There was neither fork nor SIGCHLD since last waitpid */
3851 /* Avoid doing waitpid syscall if possible */
3852 if (!G.we_have_children) {
3856 if (fg_pipe == NULL) { /* is WNOHANG set? */
3857 /* We have children, but they did not exit
3858 * or stop yet (we saw no SIGCHLD) */
3861 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3865 /* Do we do this right?
3866 * bash-3.00# sleep 20 | false
3868 * [3]+ Stopped sleep 20 | false
3869 * bash-3.00# echo $?
3870 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3871 * [hush 1.14.0: yes we do it right]
3878 #if ENABLE_HUSH_FAST
3879 i = G.count_SIGCHLD;
3881 childpid = waitpid(-1, &status, attributes);
3882 if (childpid <= 0) {
3883 if (childpid && errno != ECHILD)
3884 bb_perror_msg("waitpid");
3885 #if ENABLE_HUSH_FAST
3886 else { /* Until next SIGCHLD, waitpid's are useless */
3887 G.we_have_children = (childpid == 0);
3888 G.handled_SIGCHLD = i;
3889 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3894 dead = WIFEXITED(status) || WIFSIGNALED(status);
3897 if (WIFSTOPPED(status))
3898 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3899 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3900 if (WIFSIGNALED(status))
3901 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3902 childpid, WTERMSIG(status), WEXITSTATUS(status));
3903 if (WIFEXITED(status))
3904 debug_printf_jobs("pid %d exited, exitcode %d\n",
3905 childpid, WEXITSTATUS(status));
3907 /* Were we asked to wait for fg pipe? */
3909 for (i = 0; i < fg_pipe->num_cmds; i++) {
3910 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3911 if (fg_pipe->cmds[i].pid != childpid)
3914 fg_pipe->cmds[i].pid = 0;
3915 fg_pipe->alive_cmds--;
3916 if (i == fg_pipe->num_cmds - 1) {
3917 /* last process gives overall exitstatus */
3918 rcode = WEXITSTATUS(status);
3919 /* bash prints killer signal's name for *last*
3920 * process in pipe (prints just newline for SIGINT).
3921 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3923 if (WIFSIGNALED(status)) {
3924 int sig = WTERMSIG(status);
3925 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3926 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
3927 * Maybe we need to use sig | 128? */
3930 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3933 fg_pipe->cmds[i].is_stopped = 1;
3934 fg_pipe->stopped_cmds++;
3936 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3937 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3938 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3939 /* All processes in fg pipe have exited or stopped */
3940 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3941 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3942 * and "killall -STOP cat" */
3943 if (G_interactive_fd) {
3945 if (fg_pipe->alive_cmds)
3946 insert_bg_job(fg_pipe);
3950 if (!fg_pipe->alive_cmds)
3953 /* There are still running processes in the fg pipe */
3954 goto wait_more; /* do waitpid again */
3956 /* it wasnt fg_pipe, look for process in bg pipes */
3960 /* We asked to wait for bg or orphaned children */
3961 /* No need to remember exitcode in this case */
3962 for (pi = G.job_list; pi; pi = pi->next) {
3963 for (i = 0; i < pi->num_cmds; i++) {
3964 if (pi->cmds[i].pid == childpid)
3965 goto found_pi_and_prognum;
3968 /* Happens when shell is used as init process (init=/bin/sh) */
3969 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3970 continue; /* do waitpid again */
3972 found_pi_and_prognum:
3975 pi->cmds[i].pid = 0;
3977 if (!pi->alive_cmds) {
3978 if (G_interactive_fd)
3979 printf(JOB_STATUS_FORMAT, pi->jobid,
3980 "Done", pi->cmdtext);
3981 delete_finished_bg_job(pi);
3985 pi->cmds[i].is_stopped = 1;
3989 } /* while (waitpid succeeds)... */
3995 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3998 int rcode = checkjobs(fg_pipe);
3999 if (G_saved_tty_pgrp) {
4000 /* Job finished, move the shell to the foreground */
4001 p = getpgrp(); /* our process group id */
4002 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4003 tcsetpgrp(G_interactive_fd, p);
4009 /* Start all the jobs, but don't wait for anything to finish.
4012 * Return code is normally -1, when the caller has to wait for children
4013 * to finish to determine the exit status of the pipe. If the pipe
4014 * is a simple builtin command, however, the action is done by the
4015 * time run_pipe returns, and the exit code is provided as the
4018 * Returns -1 only if started some children. IOW: we have to
4019 * mask out retvals of builtins etc with 0xff!
4021 * The only case when we do not need to [v]fork is when the pipe
4022 * is single, non-backgrounded, non-subshell command. Examples:
4023 * cmd ; ... { list } ; ...
4024 * cmd && ... { list } && ...
4025 * cmd || ... { list } || ...
4026 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4027 * or (if SH_STANDALONE) an applet, and we can run the { list }
4028 * with run_list. If it isn't one of these, we fork and exec cmd.
4030 * Cases when we must fork:
4031 * non-single: cmd | cmd
4032 * backgrounded: cmd & { list } &
4033 * subshell: ( list ) [&]
4035 static NOINLINE int run_pipe(struct pipe *pi)
4037 static const char *const null_ptr = NULL;
4040 struct command *command;
4041 char **argv_expanded;
4044 /* it is not always needed, but we aim to smaller code */
4045 int squirrel[] = { -1, -1, -1 };
4048 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4051 IF_HUSH_JOB(pi->pgrp = -1;)
4052 pi->stopped_cmds = 0;
4053 command = &(pi->cmds[0]);
4054 argv_expanded = NULL;
4056 if (pi->num_cmds != 1
4057 || pi->followup == PIPE_BG
4058 || command->cmd_type == CMD_SUBSHELL
4065 debug_printf_exec(": group:%p argv:'%s'\n",
4066 command->group, command->argv ? command->argv[0] : "NONE");
4068 if (command->group) {
4069 #if ENABLE_HUSH_FUNCTIONS
4070 if (command->cmd_type == CMD_FUNCDEF) {
4071 /* "executing" func () { list } */
4072 struct function *funcp;
4074 funcp = new_function(command->argv[0]);
4075 /* funcp->name is already set to argv[0] */
4076 funcp->body = command->group;
4078 funcp->body_as_string = command->group_as_string;
4079 command->group_as_string = NULL;
4081 command->group = NULL;
4082 command->argv[0] = NULL;
4083 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4084 funcp->parent_cmd = command;
4085 command->child_func = funcp;
4087 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4089 return EXIT_SUCCESS;
4093 debug_printf("non-subshell group\n");
4094 rcode = 1; /* exitcode if redir failed */
4095 if (setup_redirects(command, squirrel) == 0) {
4096 debug_printf_exec(": run_list\n");
4097 rcode = run_list(command->group) & 0xff;
4099 restore_redirects(squirrel);
4100 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4102 debug_printf_exec("run_pipe: return %d\n", rcode);
4106 argv = command->argv ? command->argv : (char **) &null_ptr;
4108 const struct built_in_command *x;
4109 #if ENABLE_HUSH_FUNCTIONS
4110 const struct function *funcp;
4114 char **new_env = NULL;
4115 struct variable *old_vars = NULL;
4117 if (argv[command->assignment_cnt] == NULL) {
4118 /* Assignments, but no command */
4119 /* Ensure redirects take effect (that is, create files).
4120 * Try "a=t >file": */
4121 rcode = setup_redirects(command, squirrel);
4122 restore_redirects(squirrel);
4123 /* Set shell variables */
4125 p = expand_string_to_string(*argv);
4126 debug_printf_exec("set shell var:'%s'->'%s'\n",
4128 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4131 /* Redirect error sets $? to 1. Othervise,
4132 * if evaluating assignment value set $?, retain it.
4133 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4135 rcode = G.last_exitcode;
4136 /* Do we need to flag set_local_var() errors?
4137 * "assignment to readonly var" and "putenv error"
4139 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4141 debug_printf_exec("run_pipe: return %d\n", rcode);
4145 /* Expand the rest into (possibly) many strings each */
4147 #if ENABLE_HUSH_BASH_COMPAT
4148 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4149 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4152 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4153 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4154 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4159 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4162 /* if someone gives us an empty string: `cmd with empty output` */
4163 if (!argv_expanded[0]) {
4164 free(argv_expanded);
4166 return G.last_exitcode;
4169 x = find_builtin(argv_expanded[0]);
4170 #if ENABLE_HUSH_FUNCTIONS
4173 funcp = find_function(argv_expanded[0]);
4177 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4178 debug_printf("exec with redirects only\n");
4179 rcode = setup_redirects(command, NULL);
4180 goto clean_up_and_ret1;
4183 /* setup_redirects acts on file descriptors, not FILEs.
4184 * This is perfect for work that comes after exec().
4185 * Is it really safe for inline use? Experimentally,
4186 * things seem to work. */
4187 rcode = setup_redirects(command, squirrel);
4189 new_env = expand_assignments(argv, command->assignment_cnt);
4190 old_vars = set_vars_and_save_old(new_env);
4192 debug_printf_exec(": builtin '%s' '%s'...\n",
4193 x->b_cmd, argv_expanded[1]);
4194 rcode = x->b_function(argv_expanded) & 0xff;
4197 #if ENABLE_HUSH_FUNCTIONS
4199 # if ENABLE_HUSH_LOCAL
4200 struct variable **sv;
4201 sv = G.shadowed_vars_pp;
4202 G.shadowed_vars_pp = &old_vars;
4204 debug_printf_exec(": function '%s' '%s'...\n",
4205 funcp->name, argv_expanded[1]);
4206 rcode = run_function(funcp, argv_expanded) & 0xff;
4207 # if ENABLE_HUSH_LOCAL
4208 G.shadowed_vars_pp = sv;
4213 #if ENABLE_FEATURE_SH_STANDALONE
4216 restore_redirects(squirrel);
4217 unset_vars(new_env);
4220 free(argv_expanded);
4221 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4223 debug_printf_exec("run_pipe return %d\n", rcode);
4227 #if ENABLE_FEATURE_SH_STANDALONE
4228 i = find_applet_by_name(argv_expanded[0]);
4229 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4230 rcode = setup_redirects(command, squirrel);
4232 new_env = expand_assignments(argv, command->assignment_cnt);
4233 old_vars = set_vars_and_save_old(new_env);
4234 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4235 argv_expanded[0], argv_expanded[1]);
4236 rcode = run_nofork_applet(i, argv_expanded);
4238 goto clean_up_and_ret;
4241 /* It is neither builtin nor applet. We must fork. */
4245 /* NB: argv_expanded may already be created, and that
4246 * might include `cmd` runs! Do not rerun it! We *must*
4247 * use argv_expanded if it's non-NULL */
4249 /* Going to fork a child per each pipe member */
4253 for (i = 0; i < pi->num_cmds; i++) {
4254 struct fd_pair pipefds;
4256 volatile nommu_save_t nommu_save;
4257 nommu_save.new_env = NULL;
4258 nommu_save.old_vars = NULL;
4259 nommu_save.argv = NULL;
4260 nommu_save.argv_from_re_execing = NULL;
4262 command = &(pi->cmds[i]);
4263 if (command->argv) {
4264 debug_printf_exec(": pipe member '%s' '%s'...\n",
4265 command->argv[0], command->argv[1]);
4267 debug_printf_exec(": pipe member with no argv\n");
4270 /* pipes are inserted between pairs of commands */
4273 if ((i + 1) < pi->num_cmds)
4274 xpiped_pair(pipefds);
4276 command->pid = BB_MMU ? fork() : vfork();
4277 if (!command->pid) { /* child */
4279 disable_restore_tty_pgrp_on_exit();
4280 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4282 /* Every child adds itself to new process group
4283 * with pgid == pid_of_first_child_in_pipe */
4284 if (G.run_list_level == 1 && G_interactive_fd) {
4287 if (pgrp < 0) /* true for 1st process only */
4289 if (setpgid(0, pgrp) == 0
4290 && pi->followup != PIPE_BG
4291 && G_saved_tty_pgrp /* we have ctty */
4293 /* We do it in *every* child, not just first,
4295 tcsetpgrp(G_interactive_fd, pgrp);
4299 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4300 /* 1st cmd in backgrounded pipe
4301 * should have its stdin /dev/null'ed */
4303 if (open(bb_dev_null, O_RDONLY))
4304 xopen("/", O_RDONLY);
4306 xmove_fd(nextin, 0);
4308 xmove_fd(pipefds.wr, 1);
4311 /* Like bash, explicit redirects override pipes,
4312 * and the pipe fd is available for dup'ing. */
4313 if (setup_redirects(command, NULL))
4316 /* Restore default handlers just prior to exec */
4317 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4319 /* Stores to nommu_save list of env vars putenv'ed
4320 * (NOMMU, on MMU we don't need that) */
4321 /* cast away volatility... */
4322 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4323 /* pseudo_exec() does not return */
4326 /* parent or error */
4327 #if ENABLE_HUSH_FAST
4329 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4331 enable_restore_tty_pgrp_on_exit();
4333 /* Clean up after vforked child */
4334 free(nommu_save.argv);
4335 free(nommu_save.argv_from_re_execing);
4336 unset_vars(nommu_save.new_env);
4337 add_vars(nommu_save.old_vars);
4339 free(argv_expanded);
4340 argv_expanded = NULL;
4341 if (command->pid < 0) { /* [v]fork failed */
4342 /* Clearly indicate, was it fork or vfork */
4343 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4347 /* Second and next children need to know pid of first one */
4349 pi->pgrp = command->pid;
4355 if ((i + 1) < pi->num_cmds)
4357 /* Pass read (output) pipe end to next iteration */
4358 nextin = pipefds.rd;
4361 if (!pi->alive_cmds) {
4363 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4368 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4372 #ifndef debug_print_tree
4373 static void debug_print_tree(struct pipe *pi, int lvl)
4375 static const char *const PIPE[] = {
4381 static const char *RES[] = {
4382 [RES_NONE ] = "NONE" ,
4385 [RES_THEN ] = "THEN" ,
4386 [RES_ELIF ] = "ELIF" ,
4387 [RES_ELSE ] = "ELSE" ,
4390 # if ENABLE_HUSH_LOOPS
4391 [RES_FOR ] = "FOR" ,
4392 [RES_WHILE] = "WHILE",
4393 [RES_UNTIL] = "UNTIL",
4395 [RES_DONE ] = "DONE" ,
4397 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4400 # if ENABLE_HUSH_CASE
4401 [RES_CASE ] = "CASE" ,
4402 [RES_CASE_IN ] = "CASE_IN" ,
4403 [RES_MATCH] = "MATCH",
4404 [RES_CASE_BODY] = "CASE_BODY",
4405 [RES_ESAC ] = "ESAC" ,
4407 [RES_XXXX ] = "XXXX" ,
4408 [RES_SNTX ] = "SNTX" ,
4410 static const char *const CMDTYPE[] = {
4414 # if ENABLE_HUSH_FUNCTIONS
4423 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4424 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4426 while (prn < pi->num_cmds) {
4427 struct command *command = &pi->cmds[prn];
4428 char **argv = command->argv;
4430 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4432 command->assignment_cnt);
4433 if (command->group) {
4434 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4435 CMDTYPE[command->cmd_type],
4438 , " group_as_string:", command->group_as_string
4443 debug_print_tree(command->group, lvl+1);
4447 if (argv) while (*argv) {
4448 fprintf(stderr, " '%s'", *argv);
4451 fprintf(stderr, "\n");
4458 #endif /* debug_print_tree */
4460 /* NB: called by pseudo_exec, and therefore must not modify any
4461 * global data until exec/_exit (we can be a child after vfork!) */
4462 static int run_list(struct pipe *pi)
4464 #if ENABLE_HUSH_CASE
4465 char *case_word = NULL;
4467 #if ENABLE_HUSH_LOOPS
4468 struct pipe *loop_top = NULL;
4469 char **for_lcur = NULL;
4470 char **for_list = NULL;
4472 smallint last_followup;
4474 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4475 smalluint cond_code = 0;
4477 enum { cond_code = 0 };
4480 smallint rword; /* enum reserved_style */
4481 smallint last_rword; /* ditto */
4484 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4487 #if ENABLE_HUSH_LOOPS
4488 /* Check syntax for "for" */
4489 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4490 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4492 /* current word is FOR or IN (BOLD in comments below) */
4493 if (cpipe->next == NULL) {
4494 syntax_error("malformed for");
4496 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4499 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4500 if (cpipe->next->res_word == RES_DO)
4502 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4503 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4504 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4506 syntax_error("malformed for");
4508 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4514 /* Past this point, all code paths should jump to ret: label
4515 * in order to return, no direct "return" statements please.
4516 * This helps to ensure that no memory is leaked. */
4524 last_rword = RES_XXXX;
4526 last_followup = PIPE_SEQ;
4527 rcode = G.last_exitcode;
4529 /* Go through list of pipes, (maybe) executing them. */
4530 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4534 IF_HAS_KEYWORDS(rword = pi->res_word;)
4535 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4536 rword, cond_code, last_rword);
4537 #if ENABLE_HUSH_LOOPS
4538 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4539 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4541 /* start of a loop: remember where loop starts */
4546 /* Still in the same "if...", "then..." or "do..." branch? */
4547 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4548 if ((rcode == 0 && last_followup == PIPE_OR)
4549 || (rcode != 0 && last_followup == PIPE_AND)
4551 /* It is "<true> || CMD" or "<false> && CMD"
4552 * and we should not execute CMD */
4553 debug_printf_exec("skipped cmd because of || or &&\n");
4554 last_followup = pi->followup;
4558 last_followup = pi->followup;
4559 IF_HAS_KEYWORDS(last_rword = rword;)
4562 if (rword == RES_THEN) {
4563 /* if false; then ... fi has exitcode 0! */
4564 G.last_exitcode = rcode = EXIT_SUCCESS;
4565 /* "if <false> THEN cmd": skip cmd */
4569 if (rword == RES_ELSE || rword == RES_ELIF) {
4570 /* "if <true> then ... ELSE/ELIF cmd":
4571 * skip cmd and all following ones */
4576 #if ENABLE_HUSH_LOOPS
4577 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4579 /* first loop through for */
4581 static const char encoded_dollar_at[] ALIGN1 = {
4582 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4583 }; /* encoded representation of "$@" */
4584 static const char *const encoded_dollar_at_argv[] = {
4585 encoded_dollar_at, NULL
4586 }; /* argv list with one element: "$@" */
4589 vals = (char**)encoded_dollar_at_argv;
4590 if (pi->next->res_word == RES_IN) {
4591 /* if no variable values after "in" we skip "for" */
4592 if (!pi->next->cmds[0].argv) {
4593 G.last_exitcode = rcode = EXIT_SUCCESS;
4594 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4597 vals = pi->next->cmds[0].argv;
4598 } /* else: "for var; do..." -> assume "$@" list */
4599 /* create list of variable values */
4600 debug_print_strings("for_list made from", vals);
4601 for_list = expand_strvec_to_strvec(vals);
4602 for_lcur = for_list;
4603 debug_print_strings("for_list", for_list);
4606 /* "for" loop is over, clean up */
4612 /* Insert next value from for_lcur */
4613 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4614 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4617 if (rword == RES_IN) {
4618 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4620 if (rword == RES_DONE) {
4621 continue; /* "done" has no cmds too */
4624 #if ENABLE_HUSH_CASE
4625 if (rword == RES_CASE) {
4626 case_word = expand_strvec_to_string(pi->cmds->argv);
4629 if (rword == RES_MATCH) {
4632 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4634 /* all prev words didn't match, does this one match? */
4635 argv = pi->cmds->argv;
4637 char *pattern = expand_string_to_string(*argv);
4638 /* TODO: which FNM_xxx flags to use? */
4639 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4641 if (cond_code == 0) { /* match! we will execute this branch */
4642 free(case_word); /* make future "word)" stop */
4650 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4652 continue; /* not matched yet, skip this pipe */
4655 /* Just pressing <enter> in shell should check for jobs.
4656 * OTOH, in non-interactive shell this is useless
4657 * and only leads to extra job checks */
4658 if (pi->num_cmds == 0) {
4659 if (G_interactive_fd)
4660 goto check_jobs_and_continue;
4664 /* After analyzing all keywords and conditions, we decided
4665 * to execute this pipe. NB: have to do checkjobs(NULL)
4666 * after run_pipe to collect any background children,
4667 * even if list execution is to be stopped. */
4668 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4671 #if ENABLE_HUSH_LOOPS
4672 G.flag_break_continue = 0;
4674 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4676 /* We ran a builtin, function, or group.
4677 * rcode is already known
4678 * and we don't need to wait for anything. */
4679 G.last_exitcode = rcode;
4680 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4681 check_and_run_traps(0);
4682 #if ENABLE_HUSH_LOOPS
4683 /* Was it "break" or "continue"? */
4684 if (G.flag_break_continue) {
4685 smallint fbc = G.flag_break_continue;
4686 /* We might fall into outer *loop*,
4687 * don't want to break it too */
4689 G.depth_break_continue--;
4690 if (G.depth_break_continue == 0)
4691 G.flag_break_continue = 0;
4692 /* else: e.g. "continue 2" should *break* once, *then* continue */
4693 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4694 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4695 goto check_jobs_and_break;
4696 /* "continue": simulate end of loop */
4701 #if ENABLE_HUSH_FUNCTIONS
4702 if (G.flag_return_in_progress == 1) {
4703 /* same as "goto check_jobs_and_break" */
4708 } else if (pi->followup == PIPE_BG) {
4709 /* What does bash do with attempts to background builtins? */
4710 /* even bash 3.2 doesn't do that well with nested bg:
4711 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4712 * I'm NOT treating inner &'s as jobs */
4713 check_and_run_traps(0);
4715 if (G.run_list_level == 1)
4718 G.last_exitcode = rcode = EXIT_SUCCESS;
4719 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4722 if (G.run_list_level == 1 && G_interactive_fd) {
4723 /* Waits for completion, then fg's main shell */
4724 rcode = checkjobs_and_fg_shell(pi);
4725 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4726 check_and_run_traps(0);
4729 { /* This one just waits for completion */
4730 rcode = checkjobs(pi);
4731 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4732 check_and_run_traps(0);
4734 G.last_exitcode = rcode;
4738 /* Analyze how result affects subsequent commands */
4740 if (rword == RES_IF || rword == RES_ELIF)
4743 #if ENABLE_HUSH_LOOPS
4744 /* Beware of "while false; true; do ..."! */
4745 if (pi->next && pi->next->res_word == RES_DO) {
4746 if (rword == RES_WHILE) {
4748 /* "while false; do...done" - exitcode 0 */
4749 G.last_exitcode = rcode = EXIT_SUCCESS;
4750 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4751 goto check_jobs_and_break;
4754 if (rword == RES_UNTIL) {
4756 debug_printf_exec(": until expr is true: breaking\n");
4757 check_jobs_and_break:
4765 check_jobs_and_continue:
4772 #if ENABLE_HUSH_LOOPS
4777 #if ENABLE_HUSH_CASE
4781 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4785 /* Select which version we will use */
4786 static int run_and_free_list(struct pipe *pi)
4789 debug_printf_exec("run_and_free_list entered\n");
4791 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4792 rcode = run_list(pi);
4794 /* free_pipe_list has the side effect of clearing memory.
4795 * In the long run that function can be merged with run_list,
4796 * but doing that now would hobble the debugging effort. */
4798 debug_printf_exec("run_and_free_list return %d\n", rcode);
4803 static struct pipe *new_pipe(void)
4806 pi = xzalloc(sizeof(struct pipe));
4807 /*pi->followup = 0; - deliberately invalid value */
4808 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4812 /* Command (member of a pipe) is complete, or we start a new pipe
4813 * if ctx->command is NULL.
4814 * No errors possible here.
4816 static int done_command(struct parse_context *ctx)
4818 /* The command is really already in the pipe structure, so
4819 * advance the pipe counter and make a new, null command. */
4820 struct pipe *pi = ctx->pipe;
4821 struct command *command = ctx->command;
4824 if (IS_NULL_CMD(command)) {
4825 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4829 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4830 //debug_print_tree(ctx->list_head, 20);
4832 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4835 /* Only real trickiness here is that the uncommitted
4836 * command structure is not counted in pi->num_cmds. */
4837 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4838 ctx->command = command = &pi->cmds[pi->num_cmds];
4840 memset(command, 0, sizeof(*command));
4841 return pi->num_cmds; /* used only for 0/nonzero check */
4844 static void done_pipe(struct parse_context *ctx, pipe_style type)
4848 debug_printf_parse("done_pipe entered, followup %d\n", type);
4849 /* Close previous command */
4850 not_null = done_command(ctx);
4851 ctx->pipe->followup = type;
4853 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4854 ctx->ctx_inverted = 0;
4855 ctx->pipe->res_word = ctx->ctx_res_w;
4858 /* Without this check, even just <enter> on command line generates
4859 * tree of three NOPs (!). Which is harmless but annoying.
4860 * IOW: it is safe to do it unconditionally. */
4863 || ctx->ctx_res_w == RES_FI
4865 #if ENABLE_HUSH_LOOPS
4866 || ctx->ctx_res_w == RES_DONE
4867 || ctx->ctx_res_w == RES_FOR
4868 || ctx->ctx_res_w == RES_IN
4870 #if ENABLE_HUSH_CASE
4871 || ctx->ctx_res_w == RES_ESAC
4875 debug_printf_parse("done_pipe: adding new pipe: "
4876 "not_null:%d ctx->ctx_res_w:%d\n",
4877 not_null, ctx->ctx_res_w);
4879 ctx->pipe->next = new_p;
4881 /* RES_THEN, RES_DO etc are "sticky" -
4882 * they remain set for pipes inside if/while.
4883 * This is used to control execution.
4884 * RES_FOR and RES_IN are NOT sticky (needed to support
4885 * cases where variable or value happens to match a keyword):
4887 #if ENABLE_HUSH_LOOPS
4888 if (ctx->ctx_res_w == RES_FOR
4889 || ctx->ctx_res_w == RES_IN)
4890 ctx->ctx_res_w = RES_NONE;
4892 #if ENABLE_HUSH_CASE
4893 if (ctx->ctx_res_w == RES_MATCH)
4894 ctx->ctx_res_w = RES_CASE_BODY;
4895 if (ctx->ctx_res_w == RES_CASE)
4896 ctx->ctx_res_w = RES_CASE_IN;
4898 ctx->command = NULL; /* trick done_command below */
4899 /* Create the memory for command, roughly:
4900 * ctx->pipe->cmds = new struct command;
4901 * ctx->command = &ctx->pipe->cmds[0];
4904 //debug_print_tree(ctx->list_head, 10);
4906 debug_printf_parse("done_pipe return\n");
4909 static void initialize_context(struct parse_context *ctx)
4911 memset(ctx, 0, sizeof(*ctx));
4912 ctx->pipe = ctx->list_head = new_pipe();
4913 /* Create the memory for command, roughly:
4914 * ctx->pipe->cmds = new struct command;
4915 * ctx->command = &ctx->pipe->cmds[0];
4920 /* If a reserved word is found and processed, parse context is modified
4921 * and 1 is returned.
4924 struct reserved_combo {
4927 unsigned char assignment_flag;
4931 FLAG_END = (1 << RES_NONE ),
4933 FLAG_IF = (1 << RES_IF ),
4934 FLAG_THEN = (1 << RES_THEN ),
4935 FLAG_ELIF = (1 << RES_ELIF ),
4936 FLAG_ELSE = (1 << RES_ELSE ),
4937 FLAG_FI = (1 << RES_FI ),
4939 # if ENABLE_HUSH_LOOPS
4940 FLAG_FOR = (1 << RES_FOR ),
4941 FLAG_WHILE = (1 << RES_WHILE),
4942 FLAG_UNTIL = (1 << RES_UNTIL),
4943 FLAG_DO = (1 << RES_DO ),
4944 FLAG_DONE = (1 << RES_DONE ),
4945 FLAG_IN = (1 << RES_IN ),
4947 # if ENABLE_HUSH_CASE
4948 FLAG_MATCH = (1 << RES_MATCH),
4949 FLAG_ESAC = (1 << RES_ESAC ),
4951 FLAG_START = (1 << RES_XXXX ),
4954 static const struct reserved_combo* match_reserved_word(o_string *word)
4956 /* Mostly a list of accepted follow-up reserved words.
4957 * FLAG_END means we are done with the sequence, and are ready
4958 * to turn the compound list into a command.
4959 * FLAG_START means the word must start a new compound list.
4961 static const struct reserved_combo reserved_list[] = {
4963 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4964 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4965 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4966 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4967 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4968 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4970 # if ENABLE_HUSH_LOOPS
4971 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4972 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4973 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4974 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4975 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4976 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4978 # if ENABLE_HUSH_CASE
4979 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4980 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4983 const struct reserved_combo *r;
4985 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4986 if (strcmp(word->data, r->literal) == 0)
4991 /* Return 0: not a keyword, 1: keyword
4993 static int reserved_word(o_string *word, struct parse_context *ctx)
4995 # if ENABLE_HUSH_CASE
4996 static const struct reserved_combo reserved_match = {
4997 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5000 const struct reserved_combo *r;
5004 r = match_reserved_word(word);
5008 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5009 # if ENABLE_HUSH_CASE
5010 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5011 /* "case word IN ..." - IN part starts first MATCH part */
5012 r = &reserved_match;
5015 if (r->flag == 0) { /* '!' */
5016 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5017 syntax_error("! ! command");
5018 ctx->ctx_res_w = RES_SNTX;
5020 ctx->ctx_inverted = 1;
5023 if (r->flag & FLAG_START) {
5024 struct parse_context *old;
5026 old = xmalloc(sizeof(*old));
5027 debug_printf_parse("push stack %p\n", old);
5028 *old = *ctx; /* physical copy */
5029 initialize_context(ctx);
5031 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5032 syntax_error_at(word->data);
5033 ctx->ctx_res_w = RES_SNTX;
5036 /* "{...} fi" is ok. "{...} if" is not
5038 * if { echo foo; } then { echo bar; } fi */
5039 if (ctx->command->group)
5040 done_pipe(ctx, PIPE_SEQ);
5043 ctx->ctx_res_w = r->res;
5044 ctx->old_flag = r->flag;
5045 word->o_assignment = r->assignment_flag;
5047 if (ctx->old_flag & FLAG_END) {
5048 struct parse_context *old;
5050 done_pipe(ctx, PIPE_SEQ);
5051 debug_printf_parse("pop stack %p\n", ctx->stack);
5053 old->command->group = ctx->list_head;
5054 old->command->cmd_type = CMD_NORMAL;
5056 o_addstr(&old->as_string, ctx->as_string.data);
5057 o_free_unsafe(&ctx->as_string);
5058 old->command->group_as_string = xstrdup(old->as_string.data);
5059 debug_printf_parse("pop, remembering as:'%s'\n",
5060 old->command->group_as_string);
5062 *ctx = *old; /* physical copy */
5067 #endif /* HAS_KEYWORDS */
5069 /* Word is complete, look at it and update parsing context.
5070 * Normal return is 0. Syntax errors return 1.
5071 * Note: on return, word is reset, but not o_free'd!
5073 static int done_word(o_string *word, struct parse_context *ctx)
5075 struct command *command = ctx->command;
5077 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5078 if (word->length == 0 && word->o_quoted == 0) {
5079 debug_printf_parse("done_word return 0: true null, ignored\n");
5083 if (ctx->pending_redirect) {
5084 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5085 * only if run as "bash", not "sh" */
5086 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5088 * ...the word that follows the redirection operator
5089 * shall be subjected to tilde expansion, parameter expansion,
5090 * command substitution, arithmetic expansion, and quote
5091 * removal. Pathname expansion shall not be performed
5092 * on the word by a non-interactive shell; an interactive
5093 * shell may perform it, but shall do so only when
5094 * the expansion would result in one word."
5096 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5097 /* Cater for >\file case:
5098 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5099 * Same with heredocs:
5100 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5102 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5103 unbackslash(ctx->pending_redirect->rd_filename);
5104 /* Is it <<"HEREDOC"? */
5105 if (word->o_quoted) {
5106 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5109 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5110 ctx->pending_redirect = NULL;
5112 /* If this word wasn't an assignment, next ones definitely
5113 * can't be assignments. Even if they look like ones. */
5114 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5115 && word->o_assignment != WORD_IS_KEYWORD
5117 word->o_assignment = NOT_ASSIGNMENT;
5119 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5120 command->assignment_cnt++;
5121 word->o_assignment = MAYBE_ASSIGNMENT;
5125 # if ENABLE_HUSH_CASE
5126 if (ctx->ctx_dsemicolon
5127 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5129 /* already done when ctx_dsemicolon was set to 1: */
5130 /* ctx->ctx_res_w = RES_MATCH; */
5131 ctx->ctx_dsemicolon = 0;
5134 if (!command->argv /* if it's the first word... */
5135 # if ENABLE_HUSH_LOOPS
5136 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5137 && ctx->ctx_res_w != RES_IN
5139 # if ENABLE_HUSH_CASE
5140 && ctx->ctx_res_w != RES_CASE
5143 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5144 if (reserved_word(word, ctx)) {
5145 o_reset_to_empty_unquoted(word);
5146 debug_printf_parse("done_word return %d\n",
5147 (ctx->ctx_res_w == RES_SNTX));
5148 return (ctx->ctx_res_w == RES_SNTX);
5150 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5151 if (strcmp(word->data, "export") == 0
5152 # if ENABLE_HUSH_LOCAL
5153 || strcmp(word->data, "local") == 0
5156 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5159 # if ENABLE_HUSH_BASH_COMPAT
5160 if (strcmp(word->data, "[[") == 0) {
5161 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5167 if (command->group) {
5168 /* "{ echo foo; } echo bar" - bad */
5169 syntax_error_at(word->data);
5170 debug_printf_parse("done_word return 1: syntax error, "
5171 "groups and arglists don't mix\n");
5174 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5175 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5176 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5177 /* (otherwise it's known to be not empty and is already safe) */
5179 /* exclude "$@" - it can expand to no word despite "" */
5180 char *p = word->data;
5181 while (p[0] == SPECIAL_VAR_SYMBOL
5182 && (p[1] & 0x7f) == '@'
5183 && p[2] == SPECIAL_VAR_SYMBOL
5187 if (p == word->data || p[0] != '\0') {
5188 /* saw no "$@", or not only "$@" but some
5189 * real text is there too */
5190 /* insert "empty variable" reference, this makes
5191 * e.g. "", $empty"" etc to not disappear */
5192 o_addchr(word, SPECIAL_VAR_SYMBOL);
5193 o_addchr(word, SPECIAL_VAR_SYMBOL);
5196 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5197 debug_print_strings("word appended to argv", command->argv);
5200 #if ENABLE_HUSH_LOOPS
5201 if (ctx->ctx_res_w == RES_FOR) {
5203 || !is_well_formed_var_name(command->argv[0], '\0')
5205 /* bash says just "not a valid identifier" */
5206 syntax_error("not a valid identifier in for");
5209 /* Force FOR to have just one word (variable name) */
5210 /* NB: basically, this makes hush see "for v in ..."
5211 * syntax as if it is "for v; in ...". FOR and IN become
5212 * two pipe structs in parse tree. */
5213 done_pipe(ctx, PIPE_SEQ);
5216 #if ENABLE_HUSH_CASE
5217 /* Force CASE to have just one word */
5218 if (ctx->ctx_res_w == RES_CASE) {
5219 done_pipe(ctx, PIPE_SEQ);
5223 o_reset_to_empty_unquoted(word);
5225 debug_printf_parse("done_word return 0\n");
5230 /* Peek ahead in the input to find out if we have a "&n" construct,
5231 * as in "2>&1", that represents duplicating a file descriptor.
5233 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5234 * REDIRFD_SYNTAX_ERR if syntax error,
5235 * REDIRFD_TO_FILE if no & was seen,
5236 * or the number found.
5239 #define parse_redir_right_fd(as_string, input) \
5240 parse_redir_right_fd(input)
5242 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5248 return REDIRFD_TO_FILE;
5250 ch = i_getch(input); /* get the & */
5251 nommu_addchr(as_string, ch);
5254 ch = i_getch(input);
5255 nommu_addchr(as_string, ch);
5256 return REDIRFD_CLOSE;
5260 while (ch != EOF && isdigit(ch)) {
5261 d = d*10 + (ch-'0');
5263 ch = i_getch(input);
5264 nommu_addchr(as_string, ch);
5269 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5271 bb_error_msg("ambiguous redirect");
5272 return REDIRFD_SYNTAX_ERR;
5275 /* Return code is 0 normal, 1 if a syntax error is detected
5277 static int parse_redirect(struct parse_context *ctx,
5280 struct in_str *input)
5282 struct command *command = ctx->command;
5283 struct redir_struct *redir;
5284 struct redir_struct **redirp;
5287 dup_num = REDIRFD_TO_FILE;
5288 if (style != REDIRECT_HEREDOC) {
5289 /* Check for a '>&1' type redirect */
5290 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5291 if (dup_num == REDIRFD_SYNTAX_ERR)
5294 int ch = i_peek(input);
5295 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5296 if (dup_num) { /* <<-... */
5297 ch = i_getch(input);
5298 nommu_addchr(&ctx->as_string, ch);
5303 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5304 int ch = i_peek(input);
5306 /* >|FILE redirect ("clobbering" >).
5307 * Since we do not support "set -o noclobber" yet,
5308 * >| and > are the same for now. Just eat |.
5310 ch = i_getch(input);
5311 nommu_addchr(&ctx->as_string, ch);
5315 /* Create a new redir_struct and append it to the linked list */
5316 redirp = &command->redirects;
5317 while ((redir = *redirp) != NULL) {
5318 redirp = &(redir->next);
5320 *redirp = redir = xzalloc(sizeof(*redir));
5321 /* redir->next = NULL; */
5322 /* redir->rd_filename = NULL; */
5323 redir->rd_type = style;
5324 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5326 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5327 redir_table[style].descrip);
5329 redir->rd_dup = dup_num;
5330 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5331 /* Erik had a check here that the file descriptor in question
5332 * is legit; I postpone that to "run time"
5333 * A "-" representation of "close me" shows up as a -3 here */
5334 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5335 redir->rd_fd, redir->rd_dup);
5337 /* Set ctx->pending_redirect, so we know what to do at the
5338 * end of the next parsed word. */
5339 ctx->pending_redirect = redir;
5344 /* If a redirect is immediately preceded by a number, that number is
5345 * supposed to tell which file descriptor to redirect. This routine
5346 * looks for such preceding numbers. In an ideal world this routine
5347 * needs to handle all the following classes of redirects...
5348 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5349 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5350 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5351 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5353 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5355 * ... If n is quoted, the number shall not be recognized as part of
5356 * the redirection expression. For example:
5358 * writes the character 2 into file a"
5359 * We are getting it right by setting ->o_quoted on any \<char>
5361 * A -1 return means no valid number was found,
5362 * the caller should use the appropriate default for this redirection.
5364 static int redirect_opt_num(o_string *o)
5368 if (o->data == NULL)
5370 num = bb_strtou(o->data, NULL, 10);
5371 if (errno || num < 0)
5373 o_reset_to_empty_unquoted(o);
5378 #define fetch_till_str(as_string, input, word, skip_tabs) \
5379 fetch_till_str(input, word, skip_tabs)
5381 static char *fetch_till_str(o_string *as_string,
5382 struct in_str *input,
5386 o_string heredoc = NULL_O_STRING;
5392 ch = i_getch(input);
5393 nommu_addchr(as_string, ch);
5395 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5396 heredoc.data[past_EOL] = '\0';
5397 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5398 return heredoc.data;
5401 o_addchr(&heredoc, ch);
5402 past_EOL = heredoc.length;
5405 ch = i_getch(input);
5406 nommu_addchr(as_string, ch);
5407 } while (skip_tabs && ch == '\t');
5408 } while (ch == '\n');
5411 o_free_unsafe(&heredoc);
5414 o_addchr(&heredoc, ch);
5415 nommu_addchr(as_string, ch);
5419 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5420 * and load them all. There should be exactly heredoc_cnt of them.
5422 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5424 struct pipe *pi = ctx->list_head;
5426 while (pi && heredoc_cnt) {
5428 struct command *cmd = pi->cmds;
5430 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5432 cmd->argv ? cmd->argv[0] : "NONE");
5433 for (i = 0; i < pi->num_cmds; i++) {
5434 struct redir_struct *redir = cmd->redirects;
5436 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5437 i, cmd->argv ? cmd->argv[0] : "NONE");
5439 if (redir->rd_type == REDIRECT_HEREDOC) {
5442 redir->rd_type = REDIRECT_HEREDOC2;
5443 /* redir->rd_dup is (ab)used to indicate <<- */
5444 p = fetch_till_str(&ctx->as_string, input,
5445 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5447 syntax_error("unexpected EOF in here document");
5450 free(redir->rd_filename);
5451 redir->rd_filename = p;
5454 redir = redir->next;
5461 /* Should be 0. If it isn't, it's a parse error */
5463 bb_error_msg_and_die("heredoc BUG 2");
5469 #if ENABLE_HUSH_TICK
5470 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5475 char **to_free = NULL;
5479 pid = BB_MMU ? fork() : vfork();
5481 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5483 if (pid == 0) { /* child */
5484 disable_restore_tty_pgrp_on_exit();
5485 /* Process substitution is not considered to be usual
5486 * 'command execution'.
5487 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5494 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5495 close(channel[0]); /* NB: close _first_, then move fd! */
5496 xmove_fd(channel[1], 1);
5497 /* Prevent it from trying to handle ctrl-z etc */
5498 IF_HUSH_JOB(G.run_list_level = 1;)
5499 /* Awful hack for `trap` or $(trap).
5501 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5502 * contains an example where "trap" is executed in a subshell:
5504 * save_traps=$(trap)
5506 * eval "$save_traps"
5508 * Standard does not say that "trap" in subshell shall print
5509 * parent shell's traps. It only says that its output
5510 * must have suitable form, but then, in the above example
5511 * (which is not supposed to be normative), it implies that.
5513 * bash (and probably other shell) does implement it
5514 * (traps are reset to defaults, but "trap" still shows them),
5515 * but as a result, "trap" logic is hopelessly messed up:
5518 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5519 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5520 * # true | trap <--- trap is in subshell - no output (ditto)
5521 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5522 * trap -- 'echo Ho' SIGWINCH
5523 * # echo `(trap)` <--- in subshell in subshell - output
5524 * trap -- 'echo Ho' SIGWINCH
5525 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5526 * trap -- 'echo Ho' SIGWINCH
5528 * The rules when to forget and when to not forget traps
5529 * get really complex and nonsensical.
5531 * Our solution: ONLY bare $(trap) or `trap` is special.
5533 s = skip_whitespace(s);
5534 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5536 static const char *const argv[] = { NULL, NULL };
5537 builtin_trap((char**)argv);
5538 exit(0); /* not _exit() - we need to fflush */
5541 reset_traps_to_defaults();
5542 parse_and_run_string(s);
5543 _exit(G.last_exitcode);
5545 /* We re-execute after vfork on NOMMU. This makes this script safe:
5546 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5547 * huge=`cat BIG` # was blocking here forever
5550 re_execute_shell(&to_free,
5560 # if ENABLE_HUSH_FAST
5562 //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);
5564 enable_restore_tty_pgrp_on_exit();
5569 close_on_exec_on(channel[0]);
5570 return xfdopen_for_read(channel[0]);
5573 /* Return code is exit status of the process that is run. */
5574 static int process_command_subs(o_string *dest, const char *s)
5577 struct in_str pipe_str;
5579 int status, ch, eol_cnt;
5581 fp = generate_stream_from_string(s, &pid);
5583 /* Now send results of command back into original context */
5584 setup_file_in_str(&pipe_str, fp);
5586 while ((ch = i_getch(&pipe_str)) != EOF) {
5592 o_addchr(dest, '\n');
5595 o_addQchr(dest, ch);
5598 debug_printf("done reading from `cmd` pipe, closing it\n");
5600 /* We need to extract exitcode. Test case
5601 * "true; echo `sleep 1; false` $?"
5603 safe_waitpid(pid, &status, 0);
5604 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5605 return WEXITSTATUS(status);
5607 #endif /* ENABLE_HUSH_TICK */
5609 #if !ENABLE_HUSH_FUNCTIONS
5610 #define parse_group(dest, ctx, input, ch) \
5611 parse_group(ctx, input, ch)
5613 static int parse_group(o_string *dest, struct parse_context *ctx,
5614 struct in_str *input, int ch)
5616 /* dest contains characters seen prior to ( or {.
5617 * Typically it's empty, but for function defs,
5618 * it contains function name (without '()'). */
5619 struct pipe *pipe_list;
5621 struct command *command = ctx->command;
5623 debug_printf_parse("parse_group entered\n");
5624 #if ENABLE_HUSH_FUNCTIONS
5625 if (ch == '(' && !dest->o_quoted) {
5627 if (done_word(dest, ctx))
5630 goto skip; /* (... */
5631 if (command->argv[1]) { /* word word ... (... */
5632 syntax_error_unexpected_ch('(');
5635 /* it is "word(..." or "word (..." */
5637 ch = i_getch(input);
5638 while (ch == ' ' || ch == '\t');
5640 syntax_error_unexpected_ch(ch);
5643 nommu_addchr(&ctx->as_string, ch);
5645 ch = i_getch(input);
5646 while (ch == ' ' || ch == '\t' || ch == '\n');
5648 syntax_error_unexpected_ch(ch);
5651 nommu_addchr(&ctx->as_string, ch);
5652 command->cmd_type = CMD_FUNCDEF;
5657 #if 0 /* Prevented by caller */
5658 if (command->argv /* word [word]{... */
5659 || dest->length /* word{... */
5660 || dest->o_quoted /* ""{... */
5663 debug_printf_parse("parse_group return 1: "
5664 "syntax error, groups and arglists don't mix\n");
5669 #if ENABLE_HUSH_FUNCTIONS
5675 command->cmd_type = CMD_SUBSHELL;
5677 /* bash does not allow "{echo...", requires whitespace */
5678 ch = i_getch(input);
5679 if (ch != ' ' && ch != '\t' && ch != '\n') {
5680 syntax_error_unexpected_ch(ch);
5683 nommu_addchr(&ctx->as_string, ch);
5688 char *as_string = NULL;
5690 pipe_list = parse_stream(&as_string, input, endch);
5693 o_addstr(&ctx->as_string, as_string);
5695 /* empty ()/{} or parse error? */
5696 if (!pipe_list || pipe_list == ERR_PTR) {
5697 /* parse_stream already emitted error msg */
5701 debug_printf_parse("parse_group return 1: "
5702 "parse_stream returned %p\n", pipe_list);
5705 command->group = pipe_list;
5707 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5708 command->group_as_string = as_string;
5709 debug_printf_parse("end of group, remembering as:'%s'\n",
5710 command->group_as_string);
5713 debug_printf_parse("parse_group return 0\n");
5715 /* command remains "open", available for possible redirects */
5718 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5719 /* Subroutines for copying $(...) and `...` things */
5720 static void add_till_backquote(o_string *dest, struct in_str *input);
5722 static void add_till_single_quote(o_string *dest, struct in_str *input)
5725 int ch = i_getch(input);
5727 syntax_error_unterm_ch('\'');
5728 /*xfunc_die(); - redundant */
5735 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5736 static void add_till_double_quote(o_string *dest, struct in_str *input)
5739 int ch = i_getch(input);
5741 syntax_error_unterm_ch('"');
5742 /*xfunc_die(); - redundant */
5746 if (ch == '\\') { /* \x. Copy both chars. */
5748 ch = i_getch(input);
5752 add_till_backquote(dest, input);
5756 //if (ch == '$') ...
5759 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5761 * "Within the backquoted style of command substitution, backslash
5762 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5763 * The search for the matching backquote shall be satisfied by the first
5764 * backquote found without a preceding backslash; during this search,
5765 * if a non-escaped backquote is encountered within a shell comment,
5766 * a here-document, an embedded command substitution of the $(command)
5767 * form, or a quoted string, undefined results occur. A single-quoted
5768 * or double-quoted string that begins, but does not end, within the
5769 * "`...`" sequence produces undefined results."
5771 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5773 static void add_till_backquote(o_string *dest, struct in_str *input)
5776 int ch = i_getch(input);
5778 syntax_error_unterm_ch('`');
5779 /*xfunc_die(); - redundant */
5784 /* \x. Copy both chars unless it is \` */
5785 int ch2 = i_getch(input);
5787 syntax_error_unterm_ch('`');
5788 /*xfunc_die(); - redundant */
5790 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5797 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5798 * quoting and nested ()s.
5799 * "With the $(command) style of command substitution, all characters
5800 * following the open parenthesis to the matching closing parenthesis
5801 * constitute the command. Any valid shell script can be used for command,
5802 * except a script consisting solely of redirections which produces
5803 * unspecified results."
5805 * echo $(echo '(TEST)' BEST) (TEST) BEST
5806 * echo $(echo 'TEST)' BEST) TEST) BEST
5807 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5809 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5813 int ch = i_getch(input);
5815 syntax_error_unterm_ch(')');
5816 /*xfunc_die(); - redundant */
5824 if (i_peek(input) == ')') {
5832 add_till_single_quote(dest, input);
5837 add_till_double_quote(dest, input);
5842 /* \x. Copy verbatim. Important for \(, \) */
5843 ch = i_getch(input);
5845 syntax_error_unterm_ch(')');
5846 /*xfunc_die(); - redundant */
5853 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5855 /* Return code: 0 for OK, 1 for syntax error */
5857 #define handle_dollar(as_string, dest, input) \
5858 handle_dollar(dest, input)
5860 static int handle_dollar(o_string *as_string,
5862 struct in_str *input)
5864 int ch = i_peek(input); /* first character after the $ */
5865 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5867 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5869 ch = i_getch(input);
5870 nommu_addchr(as_string, ch);
5872 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5874 debug_printf_parse(": '%c'\n", ch);
5875 o_addchr(dest, ch | quote_mask);
5878 if (!isalnum(ch) && ch != '_')
5880 ch = i_getch(input);
5881 nommu_addchr(as_string, ch);
5883 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5884 } else if (isdigit(ch)) {
5886 ch = i_getch(input);
5887 nommu_addchr(as_string, ch);
5888 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5889 debug_printf_parse(": '%c'\n", ch);
5890 o_addchr(dest, ch | quote_mask);
5891 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5892 } else switch (ch) {
5894 case '!': /* last bg pid */
5895 case '?': /* last exit code */
5896 case '#': /* number of args */
5897 case '*': /* args */
5898 case '@': /* args */
5899 goto make_one_char_var;
5901 bool first_char, all_digits;
5904 ch = i_getch(input);
5905 nommu_addchr(as_string, ch);
5906 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5908 /* TODO: maybe someone will try to escape the '}' */
5913 ch = i_getch(input);
5914 nommu_addchr(as_string, ch);
5921 /* ${#var}: length of var contents */
5928 /* They're being verbose and doing ${?} */
5929 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5934 && ( (all_digits && !isdigit(ch))
5935 || (!all_digits && !isalnum(ch) && ch != '_')
5938 /* handle parameter expansions
5939 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5944 case ':': /* null modifier */
5945 if (expansion == 0) {
5946 debug_printf_parse(": null modifier\n");
5951 case '#': /* remove prefix */
5952 case '%': /* remove suffix */
5953 if (expansion == 0) {
5954 debug_printf_parse(": remove suffix/prefix\n");
5959 case '-': /* default value */
5960 case '=': /* assign default */
5961 case '+': /* alternative */
5962 case '?': /* error indicate */
5963 debug_printf_parse(": parameter expansion\n");
5968 syntax_error_unterm_str("${name}");
5969 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5974 debug_printf_parse(": '%c'\n", ch);
5975 o_addchr(dest, ch | quote_mask);
5979 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5982 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
5987 ch = i_getch(input);
5988 nommu_addchr(as_string, ch);
5989 # if ENABLE_SH_MATH_SUPPORT
5990 if (i_peek(input) == '(') {
5991 ch = i_getch(input);
5992 nommu_addchr(as_string, ch);
5993 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5994 o_addchr(dest, /*quote_mask |*/ '+');
5998 add_till_closing_paren(dest, input, true);
6001 o_addstr(as_string, dest->data + pos);
6002 o_addchr(as_string, ')');
6003 o_addchr(as_string, ')');
6006 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6010 # if ENABLE_HUSH_TICK
6011 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6012 o_addchr(dest, quote_mask | '`');
6016 add_till_closing_paren(dest, input, false);
6019 o_addstr(as_string, dest->data + pos);
6020 o_addchr(as_string, ')');
6023 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6029 ch = i_getch(input);
6030 nommu_addchr(as_string, ch);
6032 if (isalnum(ch)) { /* it's $_name or $_123 */
6037 /* TODO: $_ and $-: */
6038 /* $_ Shell or shell script name; or last argument of last command
6039 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6040 * but in command's env, set to full pathname used to invoke it */
6041 /* $- Option flags set by set builtin or shell options (-i etc) */
6043 o_addQchr(dest, '$');
6045 debug_printf_parse("handle_dollar return 0\n");
6050 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6051 parse_stream_dquoted(dest, input, dquote_end)
6053 static int parse_stream_dquoted(o_string *as_string,
6055 struct in_str *input,
6062 ch = i_getch(input);
6064 nommu_addchr(as_string, ch);
6065 if (ch == dquote_end) { /* may be only '"' or EOF */
6066 if (dest->o_assignment == NOT_ASSIGNMENT)
6067 dest->o_escape ^= 1;
6068 debug_printf_parse("parse_stream_dquoted return 0\n");
6071 /* note: can't move it above ch == dquote_end check! */
6073 syntax_error_unterm_ch('"');
6074 /*xfunc_die(); - redundant */
6078 next = i_peek(input);
6080 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6081 ch, ch, dest->o_escape);
6084 syntax_error("\\<eof>");
6088 * "The backslash retains its special meaning [in "..."]
6089 * only when followed by one of the following characters:
6090 * $, `, ", \, or <newline>. A double quote may be quoted
6091 * within double quotes by preceding it with a backslash."
6093 if (strchr("$`\"\\\n", next) != NULL) {
6094 ch = i_getch(input);
6096 o_addqchr(dest, ch);
6097 nommu_addchr(as_string, ch);
6100 o_addqchr(dest, '\\');
6101 nommu_addchr(as_string, '\\');
6106 if (handle_dollar(as_string, dest, input) != 0) {
6107 debug_printf_parse("parse_stream_dquoted return 1: "
6108 "handle_dollar returned non-0\n");
6113 #if ENABLE_HUSH_TICK
6115 //int pos = dest->length;
6116 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6117 o_addchr(dest, 0x80 | '`');
6118 add_till_backquote(dest, input);
6119 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6120 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6124 o_addQchr(dest, ch);
6126 && (dest->o_assignment == MAYBE_ASSIGNMENT
6127 || dest->o_assignment == WORD_IS_KEYWORD)
6128 && is_well_formed_var_name(dest->data, '=')
6130 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6136 * Scan input until EOF or end_trigger char.
6137 * Return a list of pipes to execute, or NULL on EOF
6138 * or if end_trigger character is met.
6139 * On syntax error, exit is shell is not interactive,
6140 * reset parsing machinery and start parsing anew,
6141 * or return ERR_PTR.
6143 static struct pipe *parse_stream(char **pstring,
6144 struct in_str *input,
6147 struct parse_context ctx;
6148 o_string dest = NULL_O_STRING;
6152 /* Double-quote state is handled in the state variable is_in_dquote.
6153 * A single-quote triggers a bypass of the main loop until its mate is
6154 * found. When recursing, quote state is passed in via dest->o_escape.
6156 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6157 end_trigger ? end_trigger : 'X');
6160 /* If very first arg is "" or '', dest.data may end up NULL.
6161 * Preventing this: */
6162 o_addchr(&dest, '\0');
6165 G.ifs = get_local_var_value("IFS");
6170 #if ENABLE_HUSH_INTERACTIVE
6171 input->promptmode = 0; /* PS1 */
6173 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6174 initialize_context(&ctx);
6179 const char *is_special;
6183 redir_type redir_style;
6186 /* dest.o_quoted = 1; - already is (see below) */
6187 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6190 /* We reached closing '"' */
6193 ch = i_getch(input);
6194 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6195 ch, ch, dest.o_escape);
6200 syntax_error_unterm_str("here document");
6203 /* end_trigger == '}' case errors out earlier,
6204 * checking only ')' */
6205 if (end_trigger == ')') {
6206 syntax_error_unterm_ch('('); /* exits */
6207 /* goto parse_error; */
6210 if (done_word(&dest, &ctx)) {
6214 done_pipe(&ctx, PIPE_SEQ);
6216 /* If we got nothing... */
6217 /* (this makes bare "&" cmd a no-op.
6218 * bash says: "syntax error near unexpected token '&'") */
6219 if (pi->num_cmds == 0
6220 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6226 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6228 *pstring = ctx.as_string.data;
6230 o_free_unsafe(&ctx.as_string);
6233 debug_printf_parse("parse_stream return %p\n", pi);
6236 nommu_addchr(&ctx.as_string, ch);
6240 next = i_peek(input);
6242 is_special = "{}<>;&|()#'" /* special outside of "str" */
6243 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6244 /* Are { and } special here? */
6245 if (ctx.command->argv /* word [word]{... - non-special */
6246 || dest.length /* word{... - non-special */
6247 || dest.o_quoted /* ""{... - non-special */
6248 || (next != ';' /* }; - special */
6249 && next != ')' /* }) - special */
6250 && next != '&' /* }& and }&& ... - special */
6251 && next != '|' /* }|| ... - special */
6252 && !strchr(G.ifs, next) /* {word - non-special */
6255 /* They are not special, skip "{}" */
6258 is_special = strchr(is_special, ch);
6259 is_ifs = strchr(G.ifs, ch);
6261 if (!is_special && !is_ifs) { /* ordinary char */
6263 o_addQchr(&dest, ch);
6264 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6265 || dest.o_assignment == WORD_IS_KEYWORD)
6267 && is_well_formed_var_name(dest.data, '=')
6269 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6275 if (done_word(&dest, &ctx)) {
6279 #if ENABLE_HUSH_CASE
6280 /* "case ... in <newline> word) ..." -
6281 * newlines are ignored (but ';' wouldn't be) */
6282 if (ctx.command->argv == NULL
6283 && ctx.ctx_res_w == RES_MATCH
6288 /* Treat newline as a command separator. */
6289 done_pipe(&ctx, PIPE_SEQ);
6290 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6292 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6297 dest.o_assignment = MAYBE_ASSIGNMENT;
6299 /* note: if (is_ifs) continue;
6300 * will still trigger for us */
6304 /* "cmd}" or "cmd }..." without semicolon or &:
6305 * } is an ordinary char in this case, even inside { cmd; }
6306 * Pathological example: { ""}; } should exec "}" cmd
6309 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6310 || dest.length != 0 /* word} */
6311 || dest.o_quoted /* ""} */
6315 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6316 goto skip_end_trigger;
6317 /* else: } does terminate a group */
6320 if (end_trigger && end_trigger == ch
6321 && (ch != ';' || heredoc_cnt == 0)
6322 #if ENABLE_HUSH_CASE
6324 || ctx.ctx_res_w != RES_MATCH
6325 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6330 /* This is technically valid:
6331 * { cat <<HERE; }; echo Ok
6335 * but we don't support this.
6336 * We require heredoc to be in enclosing {}/(),
6339 syntax_error_unterm_str("here document");
6342 if (done_word(&dest, &ctx)) {
6345 done_pipe(&ctx, PIPE_SEQ);
6346 dest.o_assignment = MAYBE_ASSIGNMENT;
6347 /* Do we sit outside of any if's, loops or case's? */
6349 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6353 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6355 *pstring = ctx.as_string.data;
6357 o_free_unsafe(&ctx.as_string);
6360 debug_printf_parse("parse_stream return %p: "
6361 "end_trigger char found\n",
6363 return ctx.list_head;
6370 /* Catch <, > before deciding whether this word is
6371 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6374 redir_fd = redirect_opt_num(&dest);
6375 if (done_word(&dest, &ctx)) {
6378 redir_style = REDIRECT_OVERWRITE;
6380 redir_style = REDIRECT_APPEND;
6381 ch = i_getch(input);
6382 nommu_addchr(&ctx.as_string, ch);
6385 else if (next == '(') {
6386 syntax_error(">(process) not supported");
6390 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6392 continue; /* back to top of while (1) */
6394 redir_fd = redirect_opt_num(&dest);
6395 if (done_word(&dest, &ctx)) {
6398 redir_style = REDIRECT_INPUT;
6400 redir_style = REDIRECT_HEREDOC;
6402 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6403 ch = i_getch(input);
6404 nommu_addchr(&ctx.as_string, ch);
6405 } else if (next == '>') {
6406 redir_style = REDIRECT_IO;
6407 ch = i_getch(input);
6408 nommu_addchr(&ctx.as_string, ch);
6411 else if (next == '(') {
6412 syntax_error("<(process) not supported");
6416 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6418 continue; /* back to top of while (1) */
6421 if (dest.o_assignment == MAYBE_ASSIGNMENT
6422 /* check that we are not in word in "a=1 2>word b=1": */
6423 && !ctx.pending_redirect
6425 /* ch is a special char and thus this word
6426 * cannot be an assignment */
6427 dest.o_assignment = NOT_ASSIGNMENT;
6430 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6434 if (dest.length == 0) {
6437 if (ch == EOF || ch == '\n')
6440 /* note: we do not add it to &ctx.as_string */
6442 nommu_addchr(&ctx.as_string, '\n');
6444 o_addQchr(&dest, ch);
6449 syntax_error("\\<eof>");
6452 ch = i_getch(input);
6454 o_addchr(&dest, '\\');
6455 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6456 o_addchr(&dest, ch);
6457 nommu_addchr(&ctx.as_string, ch);
6458 /* Example: echo Hello \2>file
6459 * we need to know that word 2 is quoted */
6464 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6465 ctx.as_string.data[--ctx.as_string.length] = '\0';
6470 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6471 debug_printf_parse("parse_stream parse error: "
6472 "handle_dollar returned non-0\n");
6479 ch = i_getch(input);
6481 syntax_error_unterm_ch('\'');
6482 /*xfunc_die(); - redundant */
6484 nommu_addchr(&ctx.as_string, ch);
6487 o_addqchr(&dest, ch);
6492 is_in_dquote ^= 1; /* invert */
6493 if (dest.o_assignment == NOT_ASSIGNMENT)
6496 #if ENABLE_HUSH_TICK
6501 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6502 o_addchr(&dest, '`');
6506 add_till_backquote(&dest, input);
6508 o_addstr(&ctx.as_string, dest.data + pos);
6509 o_addchr(&ctx.as_string, '`');
6511 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6512 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6517 #if ENABLE_HUSH_CASE
6520 if (done_word(&dest, &ctx)) {
6523 done_pipe(&ctx, PIPE_SEQ);
6524 #if ENABLE_HUSH_CASE
6525 /* Eat multiple semicolons, detect
6526 * whether it means something special */
6531 ch = i_getch(input);
6532 nommu_addchr(&ctx.as_string, ch);
6533 if (ctx.ctx_res_w == RES_CASE_BODY) {
6534 ctx.ctx_dsemicolon = 1;
6535 ctx.ctx_res_w = RES_MATCH;
6541 /* We just finished a cmd. New one may start
6542 * with an assignment */
6543 dest.o_assignment = MAYBE_ASSIGNMENT;
6546 if (done_word(&dest, &ctx)) {
6550 ch = i_getch(input);
6551 nommu_addchr(&ctx.as_string, ch);
6552 done_pipe(&ctx, PIPE_AND);
6554 done_pipe(&ctx, PIPE_BG);
6558 if (done_word(&dest, &ctx)) {
6561 #if ENABLE_HUSH_CASE
6562 if (ctx.ctx_res_w == RES_MATCH)
6563 break; /* we are in case's "word | word)" */
6565 if (next == '|') { /* || */
6566 ch = i_getch(input);
6567 nommu_addchr(&ctx.as_string, ch);
6568 done_pipe(&ctx, PIPE_OR);
6570 /* we could pick up a file descriptor choice here
6571 * with redirect_opt_num(), but bash doesn't do it.
6572 * "echo foo 2| cat" yields "foo 2". */
6575 o_reset_to_empty_unquoted(&ctx.as_string);
6580 #if ENABLE_HUSH_CASE
6581 /* "case... in [(]word)..." - skip '(' */
6582 if (ctx.ctx_res_w == RES_MATCH
6583 && ctx.command->argv == NULL /* not (word|(... */
6584 && dest.length == 0 /* not word(... */
6585 && dest.o_quoted == 0 /* not ""(... */
6591 if (parse_group(&dest, &ctx, input, ch) != 0) {
6596 #if ENABLE_HUSH_CASE
6597 if (ctx.ctx_res_w == RES_MATCH)
6601 /* proper use of this character is caught by end_trigger:
6602 * if we see {, we call parse_group(..., end_trigger='}')
6603 * and it will match } earlier (not here). */
6604 syntax_error_unexpected_ch(ch);
6608 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6614 struct parse_context *pctx;
6615 IF_HAS_KEYWORDS(struct parse_context *p2;)
6617 /* Clean up allocated tree.
6618 * Sample for finding leaks on syntax error recovery path.
6619 * Run it from interactive shell, watch pmap `pidof hush`.
6620 * while if false; then false; fi; do break; fi
6621 * Samples to catch leaks at execution:
6622 * while if (true | {true;}); then echo ok; fi; do break; done
6623 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6627 /* Update pipe/command counts,
6628 * otherwise freeing may miss some */
6629 done_pipe(pctx, PIPE_SEQ);
6630 debug_printf_clean("freeing list %p from ctx %p\n",
6631 pctx->list_head, pctx);
6632 debug_print_tree(pctx->list_head, 0);
6633 free_pipe_list(pctx->list_head);
6634 debug_printf_clean("freed list %p\n", pctx->list_head);
6636 o_free_unsafe(&pctx->as_string);
6638 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6642 IF_HAS_KEYWORDS(pctx = p2;)
6643 } while (HAS_KEYWORDS && pctx);
6644 /* Free text, clear all dest fields */
6646 /* If we are not in top-level parse, we return,
6647 * our caller will propagate error.
6649 if (end_trigger != ';') {
6657 /* Discard cached input, force prompt */
6659 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6664 /* Executing from string: eval, sh -c '...'
6665 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6666 * end_trigger controls how often we stop parsing
6667 * NUL: parse all, execute, return
6668 * ';': parse till ';' or newline, execute, repeat till EOF
6670 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6672 /* Why we need empty flag?
6673 * An obscure corner case "false; ``; echo $?":
6674 * empty command in `` should still set $? to 0.
6675 * But we can't just set $? to 0 at the start,
6676 * this breaks "false; echo `echo $?`" case.
6680 struct pipe *pipe_list;
6682 pipe_list = parse_stream(NULL, inp, end_trigger);
6683 if (!pipe_list) { /* EOF */
6685 G.last_exitcode = 0;
6688 debug_print_tree(pipe_list, 0);
6689 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6690 run_and_free_list(pipe_list);
6695 static void parse_and_run_string(const char *s)
6697 struct in_str input;
6698 setup_string_in_str(&input, s);
6699 parse_and_run_stream(&input, '\0');
6702 static void parse_and_run_file(FILE *f)
6704 struct in_str input;
6705 setup_file_in_str(&input, f);
6706 parse_and_run_stream(&input, ';');
6709 /* Called a few times only (or even once if "sh -c") */
6710 static void init_sigmasks(void)
6714 sigset_t old_blocked_set;
6716 if (!G.inherited_set_is_saved) {
6717 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6718 G.inherited_set = G.blocked_set;
6720 old_blocked_set = G.blocked_set;
6722 mask = (1 << SIGQUIT);
6723 if (G_interactive_fd) {
6724 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6725 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6726 mask |= SPECIAL_JOB_SIGS;
6728 G.non_DFL_mask = mask;
6733 sigaddset(&G.blocked_set, sig);
6737 sigdelset(&G.blocked_set, SIGCHLD);
6739 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6740 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6742 /* POSIX allows shell to re-enable SIGCHLD
6743 * even if it was SIG_IGN on entry */
6744 #if ENABLE_HUSH_FAST
6745 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6746 if (!G.inherited_set_is_saved)
6747 signal(SIGCHLD, SIGCHLD_handler);
6749 if (!G.inherited_set_is_saved)
6750 signal(SIGCHLD, SIG_DFL);
6753 G.inherited_set_is_saved = 1;
6758 static void maybe_set_to_sigexit(int sig)
6760 void (*handler)(int);
6761 /* non_DFL_mask'ed signals are, well, masked,
6762 * no need to set handler for them.
6764 if (!((G.non_DFL_mask >> sig) & 1)) {
6765 handler = signal(sig, sigexit);
6766 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6767 signal(sig, handler);
6770 /* Set handlers to restore tty pgrp and exit */
6771 static void set_fatal_handlers(void)
6773 /* We _must_ restore tty pgrp on fatal signals */
6775 maybe_set_to_sigexit(SIGILL );
6776 maybe_set_to_sigexit(SIGFPE );
6777 maybe_set_to_sigexit(SIGBUS );
6778 maybe_set_to_sigexit(SIGSEGV);
6779 maybe_set_to_sigexit(SIGTRAP);
6780 } /* else: hush is perfect. what SEGV? */
6781 maybe_set_to_sigexit(SIGABRT);
6782 /* bash 3.2 seems to handle these just like 'fatal' ones */
6783 maybe_set_to_sigexit(SIGPIPE);
6784 maybe_set_to_sigexit(SIGALRM);
6785 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6786 * if we aren't interactive... but in this case
6787 * we never want to restore pgrp on exit, and this fn is not called */
6788 /*maybe_set_to_sigexit(SIGHUP );*/
6789 /*maybe_set_to_sigexit(SIGTERM);*/
6790 /*maybe_set_to_sigexit(SIGINT );*/
6794 static int set_mode(const char cstate, const char mode)
6796 int state = (cstate == '-' ? 1 : 0);
6798 case 'n': G.fake_mode = state; break;
6799 case 'x': /*G.debug_mode = state;*/ break;
6800 default: return EXIT_FAILURE;
6802 return EXIT_SUCCESS;
6805 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6806 int hush_main(int argc, char **argv)
6808 static const struct variable const_shell_ver = {
6810 .varstr = (char*)hush_version_str,
6811 .max_len = 1, /* 0 can provoke free(name) */
6816 unsigned builtin_argc;
6818 struct variable *cur_var;
6821 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6822 G.last_exitcode = EXIT_SUCCESS;
6824 G.argv0_for_re_execing = argv[0];
6826 /* Deal with HUSH_VERSION */
6827 G.shell_ver = const_shell_ver; /* copying struct here */
6828 G.top_var = &G.shell_ver;
6829 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6830 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6831 /* Initialize our shell local variables with the values
6832 * currently living in the environment */
6833 cur_var = G.top_var;
6836 char *value = strchr(*e, '=');
6837 if (value) { /* paranoia */
6838 cur_var->next = xzalloc(sizeof(*cur_var));
6839 cur_var = cur_var->next;
6840 cur_var->varstr = *e;
6841 cur_var->max_len = strlen(*e);
6842 cur_var->flg_export = 1;
6846 /* reinstate HUSH_VERSION */
6847 debug_printf_env("putenv '%s'\n", hush_version_str);
6848 putenv((char *)hush_version_str);
6851 set_pwd_var(/*exp:*/ 1);
6852 /* bash also exports SHLVL and _,
6853 * and sets (but doesn't export) the following variables:
6855 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6856 * BASH_VERSION='3.2.0(1)-release'
6858 * MACHTYPE=i386-pc-linux-gnu
6860 * HOSTNAME=<xxxxxxxxxx>
6861 * PPID=<NNNNN> - we also do it elsewhere
6872 * PIPESTATUS=([0]="0")
6873 * HISTFILE=/<xxx>/.bash_history
6877 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6879 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6889 #if ENABLE_FEATURE_EDITING
6890 G.line_input_state = new_line_input_t(FOR_SHELL);
6892 G.global_argc = argc;
6893 G.global_argv = argv;
6894 /* Initialize some more globals to non-zero values */
6895 cmdedit_update_prompt();
6897 if (setjmp(die_jmp)) {
6898 /* xfunc has failed! die die die */
6899 /* no EXIT traps, this is an escape hatch! */
6901 hush_exit(xfunc_error_retval);
6904 /* Shell is non-interactive at first. We need to call
6905 * init_sigmasks() if we are going to execute "sh <script>",
6906 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6907 * If we later decide that we are interactive, we run init_sigmasks()
6908 * in order to intercept (more) signals.
6912 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6915 opt = getopt(argc, argv, "+c:xins"
6918 # if ENABLE_HUSH_FUNCTIONS
6928 * sh ... -c 'script'
6929 * sh ... -c 'script' ARG0 [ARG1...]
6930 * On NOMMU, if builtin_argc != 0,
6931 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
6932 * "" needs to be replaced with NULL
6933 * and BARGV vector fed to builtin function.
6934 * Note: the form without ARG0 never happens:
6935 * sh ... -c 'builtin' BARGV... ""
6938 G.root_pid = getpid();
6939 G.root_ppid = getppid();
6941 G.global_argv = argv + optind;
6942 G.global_argc = argc - optind;
6944 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6945 const struct built_in_command *x;
6948 x = find_builtin(optarg);
6949 if (x) { /* paranoia */
6950 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6951 G.global_argv += builtin_argc;
6952 G.global_argv[-1] = NULL; /* replace "" */
6953 G.last_exitcode = x->b_function(argv + optind - 1);
6957 if (!G.global_argv[0]) {
6958 /* -c 'script' (no params): prevent empty $0 */
6959 G.global_argv--; /* points to argv[i] of 'script' */
6960 G.global_argv[0] = argv[0];
6962 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
6964 parse_and_run_string(optarg);
6967 /* Well, we cannot just declare interactiveness,
6968 * we have to have some stuff (ctty, etc) */
6969 /* G_interactive_fd++; */
6972 /* "-s" means "read from stdin", but this is how we always
6973 * operate, so simply do nothing here. */
6976 case '<': /* "big heredoc" support */
6977 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6980 unsigned long long empty_trap_mask;
6982 G.root_pid = bb_strtou(optarg, &optarg, 16);
6984 G.root_ppid = bb_strtou(optarg, &optarg, 16);
6986 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6988 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6990 builtin_argc = bb_strtou(optarg, &optarg, 16);
6992 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
6993 if (empty_trap_mask != 0) {
6996 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6997 for (sig = 1; sig < NSIG; sig++) {
6998 if (empty_trap_mask & (1LL << sig)) {
6999 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7000 sigaddset(&G.blocked_set, sig);
7003 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7005 # if ENABLE_HUSH_LOOPS
7007 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7013 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7015 # if ENABLE_HUSH_FUNCTIONS
7017 struct function *funcp = new_function(optarg);
7018 /* funcp->name is already set to optarg */
7019 /* funcp->body is set to NULL. It's a special case. */
7020 funcp->body_as_string = argv[optind];
7028 if (!set_mode('-', opt))
7032 fprintf(stderr, "Usage: sh [FILE]...\n"
7033 " or: sh -c command [args]...\n\n");
7039 } /* option parsing loop */
7042 G.root_pid = getpid();
7043 G.root_ppid = getppid();
7046 /* If we are login shell... */
7047 if (argv[0] && argv[0][0] == '-') {
7049 debug_printf("sourcing /etc/profile\n");
7050 input = fopen_for_read("/etc/profile");
7051 if (input != NULL) {
7052 close_on_exec_on(fileno(input));
7054 parse_and_run_file(input);
7057 /* bash: after sourcing /etc/profile,
7058 * tries to source (in the given order):
7059 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7060 * stopping on first found. --noprofile turns this off.
7061 * bash also sources ~/.bash_logout on exit.
7062 * If called as sh, skips .bash_XXX files.
7069 * "bash <script>" (which is never interactive (unless -i?))
7070 * sources $BASH_ENV here (without scanning $PATH).
7071 * If called as sh, does the same but with $ENV.
7073 debug_printf("running script '%s'\n", argv[optind]);
7074 G.global_argv = argv + optind;
7075 G.global_argc = argc - optind;
7076 input = xfopen_for_read(argv[optind]);
7077 close_on_exec_on(fileno(input));
7079 parse_and_run_file(input);
7080 #if ENABLE_FEATURE_CLEAN_UP
7086 /* Up to here, shell was non-interactive. Now it may become one.
7087 * NB: don't forget to (re)run init_sigmasks() as needed.
7090 /* A shell is interactive if the '-i' flag was given,
7091 * or if all of the following conditions are met:
7093 * no arguments remaining or the -s flag given
7094 * standard input is a terminal
7095 * standard output is a terminal
7096 * Refer to Posix.2, the description of the 'sh' utility.
7099 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7100 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7101 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7102 if (G_saved_tty_pgrp < 0)
7103 G_saved_tty_pgrp = 0;
7105 /* try to dup stdin to high fd#, >= 255 */
7106 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7107 if (G_interactive_fd < 0) {
7108 /* try to dup to any fd */
7109 G_interactive_fd = dup(STDIN_FILENO);
7110 if (G_interactive_fd < 0) {
7112 G_interactive_fd = 0;
7113 G_saved_tty_pgrp = 0;
7116 // TODO: track & disallow any attempts of user
7117 // to (inadvertently) close/redirect G_interactive_fd
7119 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7120 if (G_interactive_fd) {
7121 close_on_exec_on(G_interactive_fd);
7123 if (G_saved_tty_pgrp) {
7124 /* If we were run as 'hush &', sleep until we are
7125 * in the foreground (tty pgrp == our pgrp).
7126 * If we get started under a job aware app (like bash),
7127 * make sure we are now in charge so we don't fight over
7128 * who gets the foreground */
7130 pid_t shell_pgrp = getpgrp();
7131 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7132 if (G_saved_tty_pgrp == shell_pgrp)
7134 /* send TTIN to ourself (should stop us) */
7135 kill(- shell_pgrp, SIGTTIN);
7139 /* Block some signals */
7142 if (G_saved_tty_pgrp) {
7143 /* Set other signals to restore saved_tty_pgrp */
7144 set_fatal_handlers();
7145 /* Put ourselves in our own process group
7146 * (bash, too, does this only if ctty is available) */
7147 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7148 /* Grab control of the terminal */
7149 tcsetpgrp(G_interactive_fd, getpid());
7151 /* -1 is special - makes xfuncs longjmp, not exit
7152 * (we reset die_sleep = 0 whereever we [v]fork) */
7153 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7157 #elif ENABLE_HUSH_INTERACTIVE
7158 /* No job control compiled in, only prompt/line editing */
7159 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7160 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7161 if (G_interactive_fd < 0) {
7162 /* try to dup to any fd */
7163 G_interactive_fd = dup(STDIN_FILENO);
7164 if (G_interactive_fd < 0)
7166 G_interactive_fd = 0;
7169 if (G_interactive_fd) {
7170 close_on_exec_on(G_interactive_fd);
7174 /* We have interactiveness code disabled */
7178 * if interactive but not a login shell, sources ~/.bashrc
7179 * (--norc turns this off, --rcfile <file> overrides)
7182 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7183 /* note: ash and hush share this string */
7184 printf("\n\n%s %s\n"
7185 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7188 "hush - the humble shell"
7192 parse_and_run_file(stdin);
7195 #if ENABLE_FEATURE_CLEAN_UP
7196 if (G.cwd != bb_msg_unknown)
7198 cur_var = G.top_var->next;
7200 struct variable *tmp = cur_var;
7201 if (!cur_var->max_len)
7202 free(cur_var->varstr);
7203 cur_var = cur_var->next;
7207 hush_exit(G.last_exitcode);
7212 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7213 int lash_main(int argc, char **argv)
7215 bb_error_msg("lash is deprecated, please use hush instead");
7216 return hush_main(argc, argv);
7221 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7222 int msh_main(int argc, char **argv)
7224 //bb_error_msg("msh is deprecated, please use hush instead");
7225 return hush_main(argc, argv);
7233 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7238 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7245 return applet_main_func(argc, argv - argc);
7248 static int FAST_FUNC builtin_test(char **argv)
7250 return run_applet_main(argv, test_main);
7253 static int FAST_FUNC builtin_echo(char **argv)
7255 return run_applet_main(argv, echo_main);
7259 static int FAST_FUNC builtin_printf(char **argv)
7261 return run_applet_main(argv, printf_main);
7265 static char **skip_dash_dash(char **argv)
7268 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7273 static int FAST_FUNC builtin_eval(char **argv)
7275 int rcode = EXIT_SUCCESS;
7277 argv = skip_dash_dash(argv);
7279 char *str = expand_strvec_to_string(argv);
7281 * eval "echo Hi; done" ("done" is syntax error):
7282 * "echo Hi" will not execute too.
7284 parse_and_run_string(str);
7286 rcode = G.last_exitcode;
7291 static int FAST_FUNC builtin_cd(char **argv)
7295 argv = skip_dash_dash(argv);
7297 if (newdir == NULL) {
7298 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7299 * bash says "bash: cd: HOME not set" and does nothing
7302 const char *home = get_local_var_value("HOME");
7303 newdir = home ? home : "/";
7305 if (chdir(newdir)) {
7306 /* Mimic bash message exactly */
7307 bb_perror_msg("cd: %s", newdir);
7308 return EXIT_FAILURE;
7310 /* Read current dir (get_cwd(1) is inside) and set PWD.
7311 * Note: do not enforce exporting. If PWD was unset or unexported,
7312 * set it again, but do not export. bash does the same.
7314 set_pwd_var(/*exp:*/ 0);
7315 return EXIT_SUCCESS;
7318 static int FAST_FUNC builtin_exec(char **argv)
7320 argv = skip_dash_dash(argv);
7321 if (argv[0] == NULL)
7322 return EXIT_SUCCESS; /* bash does this */
7324 /* Careful: we can end up here after [v]fork. Do not restore
7325 * tty pgrp then, only top-level shell process does that */
7326 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7327 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7329 /* TODO: if exec fails, bash does NOT exit! We do.
7330 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7331 * and tcsetpgrp, and this is inherently racy.
7333 execvp_or_die(argv);
7336 static int FAST_FUNC builtin_exit(char **argv)
7338 debug_printf_exec("%s()\n", __func__);
7340 /* interactive bash:
7341 * # trap "echo EEE" EXIT
7344 * There are stopped jobs.
7345 * (if there are _stopped_ jobs, running ones don't count)
7348 # EEE (then bash exits)
7350 * we can use G.exiting = -1 as indicator "last cmd was exit"
7353 /* note: EXIT trap is run by hush_exit */
7354 argv = skip_dash_dash(argv);
7355 if (argv[0] == NULL)
7356 hush_exit(G.last_exitcode);
7357 /* mimic bash: exit 123abc == exit 255 + error msg */
7358 xfunc_error_retval = 255;
7359 /* bash: exit -2 == exit 254, no error msg */
7360 hush_exit(xatoi(argv[0]) & 0xff);
7363 static void print_escaped(const char *s)
7368 const char *p = strchrnul(s, '\'');
7369 /* print 'xxxx', possibly just '' */
7370 printf("'%.*s'", (int)(p - s), s);
7375 /* s points to '; print "'''...'''" */
7377 do putchar('\''); while (*++s == '\'');
7382 #if !ENABLE_HUSH_LOCAL
7383 #define helper_export_local(argv, exp, lvl) \
7384 helper_export_local(argv, exp)
7386 static void helper_export_local(char **argv, int exp, int lvl)
7391 /* So far we do not check that name is valid (TODO?) */
7393 if (strchr(name, '=') == NULL) {
7394 struct variable *var;
7396 var = get_local_var(name);
7397 if (exp == -1) { /* unexporting? */
7398 /* export -n NAME (without =VALUE) */
7400 var->flg_export = 0;
7401 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7403 } /* else: export -n NOT_EXISTING_VAR: no-op */
7406 if (exp == 1) { /* exporting? */
7407 /* export NAME (without =VALUE) */
7409 var->flg_export = 1;
7410 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7411 putenv(var->varstr);
7415 /* Exporting non-existing variable.
7416 * bash does not put it in environment,
7417 * but remembers that it is exported,
7418 * and does put it in env when it is set later.
7419 * We just set it to "" and export. */
7420 /* Or, it's "local NAME" (without =VALUE).
7421 * bash sets the value to "". */
7422 name = xasprintf("%s=", name);
7424 /* (Un)exporting/making local NAME=VALUE */
7425 name = xstrdup(name);
7427 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7431 static int FAST_FUNC builtin_export(char **argv)
7433 unsigned opt_unexport;
7435 #if ENABLE_HUSH_EXPORT_N
7436 /* "!": do not abort on errors */
7437 opt_unexport = getopt32(argv, "!n");
7438 if (opt_unexport == (uint32_t)-1)
7439 return EXIT_FAILURE;
7446 if (argv[0] == NULL) {
7453 /* ash emits: export VAR='VAL'
7454 * bash: declare -x VAR="VAL"
7455 * we follow ash example */
7456 const char *s = *e++;
7457 const char *p = strchr(s, '=');
7459 if (!p) /* wtf? take next variable */
7462 printf("export %.*s", (int)(p - s) + 1, s);
7463 print_escaped(p + 1);
7467 /*fflush_all(); - done after each builtin anyway */
7469 return EXIT_SUCCESS;
7472 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7474 return EXIT_SUCCESS;
7477 #if ENABLE_HUSH_LOCAL
7478 static int FAST_FUNC builtin_local(char **argv)
7480 if (G.func_nest_level == 0) {
7481 bb_error_msg("%s: not in a function", argv[0]);
7482 return EXIT_FAILURE; /* bash compat */
7484 helper_export_local(argv, 0, G.func_nest_level);
7485 return EXIT_SUCCESS;
7489 static int FAST_FUNC builtin_trap(char **argv)
7495 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7500 /* No args: print all trapped */
7501 for (i = 0; i < NSIG; ++i) {
7504 print_escaped(G.traps[i]);
7505 /* note: bash adds "SIG", but only if invoked
7506 * as "bash". If called as "sh", or if set -o posix,
7507 * then it prints short signal names.
7508 * We are printing short names: */
7509 printf(" %s\n", get_signame(i));
7512 /*fflush_all(); - done after each builtin anyway */
7513 return EXIT_SUCCESS;
7517 /* If first arg is a number: reset all specified signals */
7518 sig = bb_strtou(*argv, NULL, 10);
7524 sig = get_signum(*argv++);
7525 if (sig < 0 || sig >= NSIG) {
7527 /* Mimic bash message exactly */
7528 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7533 G.traps[sig] = xstrdup(new_cmd);
7535 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7536 get_signame(sig), sig, G.traps[sig]);
7538 /* There is no signal for 0 (EXIT) */
7543 sigaddset(&G.blocked_set, sig);
7545 /* There was a trap handler, we are removing it
7546 * (if sig has non-DFL handling,
7547 * we don't need to do anything) */
7548 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7550 sigdelset(&G.blocked_set, sig);
7553 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7557 if (!argv[1]) { /* no second arg */
7558 bb_error_msg("trap: invalid arguments");
7559 return EXIT_FAILURE;
7562 /* First arg is "-": reset all specified to default */
7563 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7564 /* Everything else: set arg as signal handler
7565 * (includes "" case, which ignores signal) */
7566 if (argv[0][0] == '-') {
7567 if (argv[0][1] == '\0') { /* "-" */
7568 /* new_cmd remains NULL: "reset these sigs" */
7571 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7574 /* else: "-something", no special meaning */
7579 goto process_sig_list;
7582 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7583 static int FAST_FUNC builtin_type(char **argv)
7585 int ret = EXIT_SUCCESS;
7591 if (0) {} /* make conditional compile easier below */
7592 /*else if (find_alias(*argv))
7593 type = "an alias";*/
7594 #if ENABLE_HUSH_FUNCTIONS
7595 else if (find_function(*argv))
7596 type = "a function";
7598 else if (find_builtin(*argv))
7599 type = "a shell builtin";
7600 else if ((path = find_in_path(*argv)) != NULL)
7603 bb_error_msg("type: %s: not found", *argv);
7608 printf("%s is %s\n", *argv, type);
7616 /* built-in 'fg' and 'bg' handler */
7617 static int FAST_FUNC builtin_fg_bg(char **argv)
7622 if (!G_interactive_fd)
7623 return EXIT_FAILURE;
7625 /* If they gave us no args, assume they want the last backgrounded task */
7627 for (pi = G.job_list; pi; pi = pi->next) {
7628 if (pi->jobid == G.last_jobid) {
7632 bb_error_msg("%s: no current job", argv[0]);
7633 return EXIT_FAILURE;
7635 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7636 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7637 return EXIT_FAILURE;
7639 for (pi = G.job_list; pi; pi = pi->next) {
7640 if (pi->jobid == jobnum) {
7644 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7645 return EXIT_FAILURE;
7647 /* TODO: bash prints a string representation
7648 * of job being foregrounded (like "sleep 1 | cat") */
7649 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7650 /* Put the job into the foreground. */
7651 tcsetpgrp(G_interactive_fd, pi->pgrp);
7654 /* Restart the processes in the job */
7655 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7656 for (i = 0; i < pi->num_cmds; i++) {
7657 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7658 pi->cmds[i].is_stopped = 0;
7660 pi->stopped_cmds = 0;
7662 i = kill(- pi->pgrp, SIGCONT);
7664 if (errno == ESRCH) {
7665 delete_finished_bg_job(pi);
7666 return EXIT_SUCCESS;
7668 bb_perror_msg("kill (SIGCONT)");
7671 if (argv[0][0] == 'f') {
7673 return checkjobs_and_fg_shell(pi);
7675 return EXIT_SUCCESS;
7679 #if ENABLE_HUSH_HELP
7680 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7682 const struct built_in_command *x;
7685 "Built-in commands:\n"
7686 "------------------\n");
7687 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7689 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7692 return EXIT_SUCCESS;
7697 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7700 const char *status_string;
7702 for (job = G.job_list; job; job = job->next) {
7703 if (job->alive_cmds == job->stopped_cmds)
7704 status_string = "Stopped";
7706 status_string = "Running";
7708 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7710 return EXIT_SUCCESS;
7715 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7720 # ifdef M_TRIM_THRESHOLD
7721 /* Optional. Reduces probability of false positives */
7724 /* Crude attempt to find where "free memory" starts,
7725 * sans fragmentation. */
7727 l = (unsigned long)p;
7730 if (l < (unsigned long)p) l = (unsigned long)p;
7733 if (!G.memleak_value)
7734 G.memleak_value = l;
7736 l -= G.memleak_value;
7743 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7748 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7751 return EXIT_SUCCESS;
7754 static int FAST_FUNC builtin_read(char **argv)
7763 /* "!": do not abort on errors.
7764 * Option string must start with "sr" to match BUILTIN_READ_xxx
7766 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7767 if (read_flags == (uint32_t)-1)
7768 return EXIT_FAILURE;
7771 r = shell_builtin_read(set_local_var_from_halves,
7773 get_local_var_value("IFS"), /* can be NULL */
7781 if ((uintptr_t)r > 1) {
7782 bb_error_msg("%s", r);
7783 r = (char*)(uintptr_t)1;
7786 return (uintptr_t)r;
7789 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7790 * built-in 'set' handler
7792 * set [-abCefhmnuvx] [-o option] [argument...]
7793 * set [+abCefhmnuvx] [+o option] [argument...]
7794 * set -- [argument...]
7797 * Implementations shall support the options in both their hyphen and
7798 * plus-sign forms. These options can also be specified as options to sh.
7800 * Write out all variables and their values: set
7801 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7802 * Turn on the -x and -v options: set -xv
7803 * Unset all positional parameters: set --
7804 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7805 * Set the positional parameters to the expansion of x, even if x expands
7806 * with a leading '-' or '+': set -- $x
7808 * So far, we only support "set -- [argument...]" and some of the short names.
7810 static int FAST_FUNC builtin_set(char **argv)
7813 char **pp, **g_argv;
7814 char *arg = *++argv;
7818 for (e = G.top_var; e; e = e->next)
7820 return EXIT_SUCCESS;
7824 if (!strcmp(arg, "--")) {
7828 if (arg[0] != '+' && arg[0] != '-')
7830 for (n = 1; arg[n]; ++n)
7831 if (set_mode(arg[0], arg[n]))
7833 } while ((arg = *++argv) != NULL);
7834 /* Now argv[0] is 1st argument */
7837 return EXIT_SUCCESS;
7840 /* NB: G.global_argv[0] ($0) is never freed/changed */
7841 g_argv = G.global_argv;
7842 if (G.global_args_malloced) {
7848 G.global_args_malloced = 1;
7849 pp = xzalloc(sizeof(pp[0]) * 2);
7850 pp[0] = g_argv[0]; /* retain $0 */
7853 /* This realloc's G.global_argv */
7854 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7861 return EXIT_SUCCESS;
7863 /* Nothing known, so abort */
7865 bb_error_msg("set: %s: invalid option", arg);
7866 return EXIT_FAILURE;
7869 static int FAST_FUNC builtin_shift(char **argv)
7872 argv = skip_dash_dash(argv);
7876 if (n >= 0 && n < G.global_argc) {
7877 if (G.global_args_malloced) {
7880 free(G.global_argv[m++]);
7883 memmove(&G.global_argv[1], &G.global_argv[n+1],
7884 G.global_argc * sizeof(G.global_argv[0]));
7885 return EXIT_SUCCESS;
7887 return EXIT_FAILURE;
7890 static int FAST_FUNC builtin_source(char **argv)
7892 char *arg_path, *filename;
7895 #if ENABLE_HUSH_FUNCTIONS
7899 argv = skip_dash_dash(argv);
7902 /* bash says: "bash: .: filename argument required" */
7903 return 2; /* bash compat */
7906 if (!strchr(filename, '/')) {
7907 arg_path = find_in_path(filename);
7909 filename = arg_path;
7911 input = fopen_or_warn(filename, "r");
7914 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7915 return EXIT_FAILURE;
7917 close_on_exec_on(fileno(input));
7919 #if ENABLE_HUSH_FUNCTIONS
7920 sv_flg = G.flag_return_in_progress;
7921 /* "we are inside sourced file, ok to use return" */
7922 G.flag_return_in_progress = -1;
7924 save_and_replace_G_args(&sv, argv);
7926 parse_and_run_file(input);
7929 restore_G_args(&sv, argv);
7930 #if ENABLE_HUSH_FUNCTIONS
7931 G.flag_return_in_progress = sv_flg;
7934 return G.last_exitcode;
7937 static int FAST_FUNC builtin_umask(char **argv)
7943 argv = skip_dash_dash(argv);
7945 mode_t old_mask = mask;
7948 rc = bb_parse_mode(argv[0], &mask);
7953 * bash: umask: 'q': invalid symbolic mode operator
7954 * bash: umask: 999: octal number out of range
7956 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
7961 printf("%04o\n", (unsigned) mask);
7962 /* fall through and restore mask which we set to 0 */
7966 return !rc; /* rc != 0 - success */
7969 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7970 static int FAST_FUNC builtin_unset(char **argv)
7975 /* "!": do not abort on errors */
7976 /* "+": stop at 1st non-option */
7977 opts = getopt32(argv, "!+vf");
7978 if (opts == (unsigned)-1)
7979 return EXIT_FAILURE;
7981 bb_error_msg("unset: -v and -f are exclusive");
7982 return EXIT_FAILURE;
7988 if (!(opts & 2)) { /* not -f */
7989 if (unset_local_var(*argv)) {
7990 /* unset <nonexistent_var> doesn't fail.
7991 * Error is when one tries to unset RO var.
7992 * Message was printed by unset_local_var. */
7996 #if ENABLE_HUSH_FUNCTIONS
8006 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8007 static int FAST_FUNC builtin_wait(char **argv)
8009 int ret = EXIT_SUCCESS;
8012 argv = skip_dash_dash(argv);
8013 if (argv[0] == NULL) {
8014 /* Don't care about wait results */
8015 /* Note 1: must wait until there are no more children */
8016 /* Note 2: must be interruptible */
8018 * $ sleep 3 & sleep 6 & wait
8023 * $ sleep 3 & sleep 6 & wait
8027 * ^C <-- after ~4 sec from keyboard
8030 sigaddset(&G.blocked_set, SIGCHLD);
8031 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8034 if (errno == ECHILD)
8036 /* Wait for SIGCHLD or any other signal of interest */
8037 /* sigtimedwait with infinite timeout: */
8038 sig = sigwaitinfo(&G.blocked_set, NULL);
8040 sig = check_and_run_traps(sig);
8041 if (sig && sig != SIGCHLD) { /* see note 2 */
8047 sigdelset(&G.blocked_set, SIGCHLD);
8048 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8052 /* This is probably buggy wrt interruptible-ness */
8054 pid_t pid = bb_strtou(*argv, NULL, 10);
8056 /* mimic bash message */
8057 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8058 return EXIT_FAILURE;
8060 if (waitpid(pid, &status, 0) == pid) {
8061 if (WIFSIGNALED(status))
8062 ret = 128 + WTERMSIG(status);
8063 else if (WIFEXITED(status))
8064 ret = WEXITSTATUS(status);
8068 bb_perror_msg("wait %s", *argv);
8077 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8078 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8081 def = bb_strtou(argv[1], NULL, 10);
8082 if (errno || def < def_min || argv[2]) {
8083 bb_error_msg("%s: bad arguments", argv[0]);
8091 #if ENABLE_HUSH_LOOPS
8092 static int FAST_FUNC builtin_break(char **argv)
8095 if (G.depth_of_loop == 0) {
8096 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8097 return EXIT_SUCCESS; /* bash compat */
8099 G.flag_break_continue++; /* BC_BREAK = 1 */
8101 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8102 if (depth == UINT_MAX)
8103 G.flag_break_continue = BC_BREAK;
8104 if (G.depth_of_loop < depth)
8105 G.depth_break_continue = G.depth_of_loop;
8107 return EXIT_SUCCESS;
8110 static int FAST_FUNC builtin_continue(char **argv)
8112 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8113 return builtin_break(argv);
8117 #if ENABLE_HUSH_FUNCTIONS
8118 static int FAST_FUNC builtin_return(char **argv)
8122 if (G.flag_return_in_progress != -1) {
8123 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8124 return EXIT_FAILURE; /* bash compat */
8127 G.flag_return_in_progress = 1;
8130 * out of range: wraps around at 256, does not error out
8131 * non-numeric param:
8132 * f() { false; return qwe; }; f; echo $?
8133 * bash: return: qwe: numeric argument required <== we do this
8134 * 255 <== we also do this
8136 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);