1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
41 * grep for "TODO" and fix (some of them are easy)
42 * special variables (done: PWD, PPID, RANDOM)
45 * follow IFS rules more precisely, including update semantics
46 * builtins mandated by standards we don't support:
47 * [un]alias, command, fc, getopts, newgrp, readonly, times
48 * make complex ${var%...} constructs support optional
49 * make here documents optional
52 * redirection of stdout+stderr: &> and >&
53 * subst operator: ${var/[/]expr/expr}
54 * brace expansion: one/{two,three,four}
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
67 * export builtin should be special, its arguments are assignments
68 * and therefore expansion of them should be "one-word" expansion:
69 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
71 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
72 * ls: cannot access i=a: No such file or directory
73 * ls: cannot access b: No such file or directory
74 * Note1: same applies to local builtin.
75 * Note2: bash 3.2.33(1) does this only if export word itself
77 * $ export i=`echo 'aaa bbb'`; echo "$i"
79 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
82 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
84 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
85 #include <malloc.h> /* for malloc_trim */
87 /* #include <dmalloc.h> */
92 #include "shell_common.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 #include "NUM_APPLETS.h"
133 /* STANDALONE does not make sense, and won't compile */
134 # undef CONFIG_FEATURE_SH_STANDALONE
135 # undef ENABLE_FEATURE_SH_STANDALONE
136 # undef IF_FEATURE_SH_STANDALONE
137 # undef IF_NOT_FEATURE_SH_STANDALONE
138 # define ENABLE_FEATURE_SH_STANDALONE 0
139 # define IF_FEATURE_SH_STANDALONE(...)
140 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
143 #if !ENABLE_HUSH_INTERACTIVE
144 # undef ENABLE_FEATURE_EDITING
145 # define ENABLE_FEATURE_EDITING 0
146 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
147 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
150 /* Do we support ANY keywords? */
151 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
152 # define HAS_KEYWORDS 1
153 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
154 # define IF_HAS_NO_KEYWORDS(...)
156 # define HAS_KEYWORDS 0
157 # define IF_HAS_KEYWORDS(...)
158 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
161 /* If you comment out one of these below, it will be #defined later
162 * to perform debug printfs to stderr: */
163 #define debug_printf(...) do {} while (0)
164 /* Finer-grained debug switches */
165 #define debug_printf_parse(...) do {} while (0)
166 #define debug_print_tree(a, b) do {} while (0)
167 #define debug_printf_exec(...) do {} while (0)
168 #define debug_printf_env(...) do {} while (0)
169 #define debug_printf_jobs(...) do {} while (0)
170 #define debug_printf_expand(...) do {} while (0)
171 #define debug_printf_varexp(...) do {} while (0)
172 #define debug_printf_glob(...) do {} while (0)
173 #define debug_printf_list(...) do {} while (0)
174 #define debug_printf_subst(...) do {} while (0)
175 #define debug_printf_clean(...) do {} while (0)
177 #define ERR_PTR ((void*)(long)1)
179 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
181 #define _SPECIAL_VARS_STR "_*@$!?#"
182 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
183 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
185 #define SPECIAL_VAR_SYMBOL 3
189 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
191 /* This supports saving pointers malloced in vfork child,
192 * to be freed in the parent.
195 typedef struct nommu_save_t {
197 struct variable *old_vars;
199 char **argv_from_re_execing;
203 typedef enum reserved_style {
212 #if ENABLE_HUSH_LOOPS
219 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
224 /* three pseudo-keywords support contrived "case" syntax: */
225 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
226 RES_MATCH , /* "word)" */
227 RES_CASE_BODY, /* "this command is inside CASE" */
234 typedef struct o_string {
236 int length; /* position where data is appended */
238 /* Protect newly added chars against globbing
239 * (by prepending \ to *, ?, [, \) */
242 /* At least some part of the string was inside '' or "",
243 * possibly empty one: word"", wo''rd etc. */
245 smallint has_empty_slot;
246 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
249 MAYBE_ASSIGNMENT = 0,
250 DEFINITELY_ASSIGNMENT = 1,
252 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
254 /* Used for initialization: o_string foo = NULL_O_STRING; */
255 #define NULL_O_STRING { NULL }
257 /* I can almost use ordinary FILE*. Is open_memstream() universally
258 * available? Where is it documented? */
259 typedef struct in_str {
261 /* eof_flag=1: last char in ->p is really an EOF */
262 char eof_flag; /* meaningless if ->p == NULL */
264 #if ENABLE_HUSH_INTERACTIVE
266 smallint promptmode; /* 0: PS1, 1: PS2 */
269 int (*get) (struct in_str *) FAST_FUNC;
270 int (*peek) (struct in_str *) FAST_FUNC;
272 #define i_getch(input) ((input)->get(input))
273 #define i_peek(input) ((input)->peek(input))
275 /* The descrip member of this structure is only used to make
276 * debugging output pretty */
277 static const struct {
279 signed char default_fd;
282 { O_RDONLY, 0, "<" },
283 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
284 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
285 { O_CREAT|O_RDWR, 1, "<>" },
286 { O_RDONLY, 0, "<<" },
287 /* Should not be needed. Bogus default_fd helps in debugging */
288 /* { O_RDONLY, 77, "<<" }, */
291 struct redir_struct {
292 struct redir_struct *next;
293 char *rd_filename; /* filename */
294 int rd_fd; /* fd to redirect */
295 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
297 smallint rd_type; /* (enum redir_type) */
298 /* note: for heredocs, rd_filename contains heredoc delimiter,
299 * and subsequently heredoc itself; and rd_dup is a bitmask:
300 * bit 0: do we need to trim leading tabs?
301 * bit 1: is heredoc quoted (<<'delim' syntax) ?
304 typedef enum redir_type {
306 REDIRECT_OVERWRITE = 1,
309 REDIRECT_HEREDOC = 4,
310 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
313 REDIRFD_SYNTAX_ERR = -2,
314 REDIRFD_TO_FILE = -1,
315 /* otherwise, rd_fd is redirected to rd_dup */
317 HEREDOC_SKIPTABS = 1,
323 pid_t pid; /* 0 if exited */
324 int assignment_cnt; /* how many argv[i] are assignments? */
325 smallint is_stopped; /* is the command currently running? */
326 smallint cmd_type; /* CMD_xxx */
328 #define CMD_SUBSHELL 1
330 /* used for "[[ EXPR ]]" */
331 #if ENABLE_HUSH_BASH_COMPAT
332 # define CMD_SINGLEWORD_NOGLOB 2
335 /* used for "export noglob=* glob* a=`echo a b`" */
336 //#define CMD_SINGLEWORD_NOGLOB_COND 3
337 // It is hard to implement correctly, it adds significant amounts of tricky code,
338 // and all this is only useful for really obscure export statements
339 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
340 // guards the code which implements it, but I have doubts it works
341 // in all cases (especially with mixed globbed/non-globbed arguments)
343 #if ENABLE_HUSH_FUNCTIONS
344 # define CMD_FUNCDEF 3
347 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
350 char *group_as_string;
352 #if ENABLE_HUSH_FUNCTIONS
353 struct function *child_func;
354 /* This field is used to prevent a bug here:
355 * while...do f1() {a;}; f1; f1() {b;}; f1; done
356 * When we execute "f1() {a;}" cmd, we create new function and clear
357 * cmd->group, cmd->group_as_string, cmd->argv[0].
358 * When we execute "f1() {b;}", we notice that f1 exists,
359 * and that its "parent cmd" struct is still "alive",
360 * we put those fields back into cmd->xxx
361 * (struct function has ->parent_cmd ptr to facilitate that).
362 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
363 * Without this trick, loop would execute a;b;b;b;...
364 * instead of correct sequence a;b;a;b;...
365 * When command is freed, it severs the link
366 * (sets ->child_func->parent_cmd to NULL).
369 char **argv; /* command name and arguments */
370 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
371 * and on execution these are substituted with their values.
372 * Substitution can make _several_ words out of one argv[n]!
373 * Example: argv[0]=='.^C*^C.' here: echo .$*.
374 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
376 struct redir_struct *redirects; /* I/O redirections */
378 /* Is there anything in this command at all? */
379 #define IS_NULL_CMD(cmd) \
380 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
385 int num_cmds; /* total number of commands in pipe */
386 int alive_cmds; /* number of commands running (not exited) */
387 int stopped_cmds; /* number of commands alive, but stopped */
389 int jobid; /* job number */
390 pid_t pgrp; /* process group ID for the job */
391 char *cmdtext; /* name of job */
393 struct command *cmds; /* array of commands in pipe */
394 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
395 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
396 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
398 typedef enum pipe_style {
404 /* Is there anything in this pipe at all? */
405 #define IS_NULL_PIPE(pi) \
406 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
408 /* This holds pointers to the various results of parsing */
409 struct parse_context {
410 /* linked list of pipes */
411 struct pipe *list_head;
412 /* last pipe (being constructed right now) */
414 /* last command in pipe (being constructed right now) */
415 struct command *command;
416 /* last redirect in command->redirects list */
417 struct redir_struct *pending_redirect;
423 smallint ctx_inverted; /* "! cmd | cmd" */
425 smallint ctx_dsemicolon; /* ";;" seen */
427 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
429 /* group we are enclosed in:
430 * example: "if pipe1; pipe2; then pipe3; fi"
431 * when we see "if" or "then", we malloc and copy current context,
432 * and make ->stack point to it. then we parse pipeN.
433 * when closing "then" / fi" / whatever is found,
434 * we move list_head into ->stack->command->group,
435 * copy ->stack into current context, and delete ->stack.
436 * (parsing of { list } and ( list ) doesn't use this method)
438 struct parse_context *stack;
442 /* On program start, environ points to initial environment.
443 * putenv adds new pointers into it, unsetenv removes them.
444 * Neither of these (de)allocates the strings.
445 * setenv allocates new strings in malloc space and does putenv,
446 * and thus setenv is unusable (leaky) for shell's purposes */
447 #define setenv(...) setenv_is_leaky_dont_use()
449 struct variable *next;
450 char *varstr; /* points to "name=" portion */
451 #if ENABLE_HUSH_LOCAL
452 unsigned func_nest_level;
454 int max_len; /* if > 0, name is part of initial env; else name is malloced */
455 smallint flg_export; /* putenv should be done on this var */
456 smallint flg_read_only;
464 #if ENABLE_HUSH_FUNCTIONS
466 struct function *next;
468 struct command *parent_cmd;
471 char *body_as_string;
477 /* "Globals" within this file */
478 /* Sorted roughly by size (smaller offsets == smaller code) */
480 /* interactive_fd != 0 means we are an interactive shell.
481 * If we are, then saved_tty_pgrp can also be != 0, meaning
482 * that controlling tty is available. With saved_tty_pgrp == 0,
483 * job control still works, but terminal signals
484 * (^C, ^Z, ^Y, ^\) won't work at all, and background
485 * process groups can only be created with "cmd &".
486 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
487 * to give tty to the foreground process group,
488 * and will take it back when the group is stopped (^Z)
491 #if ENABLE_HUSH_INTERACTIVE
492 /* 'interactive_fd' is a fd# open to ctty, if we have one
493 * _AND_ if we decided to act interactively */
497 # define G_interactive_fd (G.interactive_fd)
499 # define G_interactive_fd 0
501 #if ENABLE_FEATURE_EDITING
502 line_input_t *line_input_state;
507 #if ENABLE_HUSH_RANDOM_SUPPORT
513 pid_t saved_tty_pgrp;
514 struct pipe *job_list;
515 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
517 # define G_saved_tty_pgrp 0
519 smallint flag_SIGINT;
520 #if ENABLE_HUSH_LOOPS
521 smallint flag_break_continue;
523 #if ENABLE_HUSH_FUNCTIONS
524 /* 0: outside of a function (or sourced file)
525 * -1: inside of a function, ok to use return builtin
526 * 1: return is invoked, skip all till end of func
528 smallint flag_return_in_progress;
531 smallint exiting; /* used to prevent EXIT trap recursion */
532 /* These four support $?, $#, and $1 */
533 smalluint last_exitcode;
534 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
535 smalluint global_args_malloced;
536 smalluint inherited_set_is_saved;
537 /* how many non-NULL argv's we have. NB: $# + 1 */
541 char *argv0_for_re_execing;
543 #if ENABLE_HUSH_LOOPS
544 unsigned depth_break_continue;
545 unsigned depth_of_loop;
549 struct variable *top_var; /* = &G.shell_ver (set in main()) */
550 struct variable shell_ver;
551 #if ENABLE_HUSH_FUNCTIONS
552 struct function *top_func;
553 # if ENABLE_HUSH_LOCAL
554 struct variable **shadowed_vars_pp;
555 unsigned func_nest_level;
558 /* Signal and trap handling */
560 unsigned count_SIGCHLD;
561 unsigned handled_SIGCHLD;
562 smallint we_have_children;
564 /* which signals have non-DFL handler (even with no traps set)? */
565 unsigned non_DFL_mask;
566 char **traps; /* char *traps[NSIG] */
567 sigset_t blocked_set;
568 sigset_t inherited_set;
570 unsigned long memleak_value;
573 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
575 #define G (*ptr_to_globals)
576 /* Not #defining name to G.name - this quickly gets unwieldy
577 * (too many defines). Also, I actually prefer to see when a variable
578 * is global, thus "G." prefix is a useful hint */
579 #define INIT_G() do { \
580 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
584 /* Function prototypes for builtins */
585 static int builtin_cd(char **argv) FAST_FUNC;
586 static int builtin_echo(char **argv) FAST_FUNC;
587 static int builtin_eval(char **argv) FAST_FUNC;
588 static int builtin_exec(char **argv) FAST_FUNC;
589 static int builtin_exit(char **argv) FAST_FUNC;
590 static int builtin_export(char **argv) FAST_FUNC;
592 static int builtin_fg_bg(char **argv) FAST_FUNC;
593 static int builtin_jobs(char **argv) FAST_FUNC;
596 static int builtin_help(char **argv) FAST_FUNC;
598 #if ENABLE_HUSH_LOCAL
599 static int builtin_local(char **argv) FAST_FUNC;
602 static int builtin_memleak(char **argv) FAST_FUNC;
605 static int builtin_printf(char **argv) FAST_FUNC;
607 static int builtin_pwd(char **argv) FAST_FUNC;
608 static int builtin_read(char **argv) FAST_FUNC;
609 static int builtin_set(char **argv) FAST_FUNC;
610 static int builtin_shift(char **argv) FAST_FUNC;
611 static int builtin_source(char **argv) FAST_FUNC;
612 static int builtin_test(char **argv) FAST_FUNC;
613 static int builtin_trap(char **argv) FAST_FUNC;
614 static int builtin_type(char **argv) FAST_FUNC;
615 static int builtin_true(char **argv) FAST_FUNC;
616 static int builtin_umask(char **argv) FAST_FUNC;
617 static int builtin_unset(char **argv) FAST_FUNC;
618 static int builtin_wait(char **argv) FAST_FUNC;
619 #if ENABLE_HUSH_LOOPS
620 static int builtin_break(char **argv) FAST_FUNC;
621 static int builtin_continue(char **argv) FAST_FUNC;
623 #if ENABLE_HUSH_FUNCTIONS
624 static int builtin_return(char **argv) FAST_FUNC;
627 /* Table of built-in functions. They can be forked or not, depending on
628 * context: within pipes, they fork. As simple commands, they do not.
629 * When used in non-forking context, they can change global variables
630 * in the parent shell process. If forked, of course they cannot.
631 * For example, 'unset foo | whatever' will parse and run, but foo will
632 * still be set at the end. */
633 struct built_in_command {
635 int (*b_function)(char **argv) FAST_FUNC;
638 # define BLTIN(cmd, func, help) { cmd, func, help }
640 # define BLTIN(cmd, func, help) { cmd, func }
644 static const struct built_in_command bltins1[] = {
645 BLTIN("." , builtin_source , "Run commands in a file"),
646 BLTIN(":" , builtin_true , NULL),
648 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
650 #if ENABLE_HUSH_LOOPS
651 BLTIN("break" , builtin_break , "Exit from a loop"),
653 BLTIN("cd" , builtin_cd , "Change directory"),
654 #if ENABLE_HUSH_LOOPS
655 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
657 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
658 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
659 BLTIN("exit" , builtin_exit , "Exit"),
660 BLTIN("export" , builtin_export , "Set environment variables"),
662 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
665 BLTIN("help" , builtin_help , NULL),
668 BLTIN("jobs" , builtin_jobs , "List jobs"),
670 #if ENABLE_HUSH_LOCAL
671 BLTIN("local" , builtin_local , "Set local variables"),
674 BLTIN("memleak" , builtin_memleak , NULL),
676 BLTIN("read" , builtin_read , "Input into variable"),
677 #if ENABLE_HUSH_FUNCTIONS
678 BLTIN("return" , builtin_return , "Return from a function"),
680 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
681 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
682 #if ENABLE_HUSH_BASH_COMPAT
683 BLTIN("source" , builtin_source , "Run commands in a file"),
685 BLTIN("trap" , builtin_trap , "Trap signals"),
686 BLTIN("type" , builtin_type , "Show command type"),
687 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
688 BLTIN("umask" , builtin_umask , "Set file creation mask"),
689 BLTIN("unset" , builtin_unset , "Unset variables"),
690 BLTIN("wait" , builtin_wait , "Wait for process"),
692 /* For now, echo and test are unconditionally enabled.
693 * Maybe make it configurable? */
694 static const struct built_in_command bltins2[] = {
695 BLTIN("[" , builtin_test , NULL),
696 BLTIN("echo" , builtin_echo , NULL),
698 BLTIN("printf" , builtin_printf , NULL),
700 BLTIN("pwd" , builtin_pwd , NULL),
701 BLTIN("test" , builtin_test , NULL),
708 /* prevent disasters with G.debug_indent < 0 */
709 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
710 # define debug_enter() (G.debug_indent++)
711 # define debug_leave() (G.debug_indent--)
713 # define indent() ((void)0)
714 # define debug_enter() ((void)0)
715 # define debug_leave() ((void)0)
719 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
722 #ifndef debug_printf_parse
723 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
726 #ifndef debug_printf_exec
727 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
730 #ifndef debug_printf_env
731 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
734 #ifndef debug_printf_jobs
735 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
736 # define DEBUG_JOBS 1
738 # define DEBUG_JOBS 0
741 #ifndef debug_printf_expand
742 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
743 # define DEBUG_EXPAND 1
745 # define DEBUG_EXPAND 0
748 #ifndef debug_printf_varexp
749 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
752 #ifndef debug_printf_glob
753 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
754 # define DEBUG_GLOB 1
756 # define DEBUG_GLOB 0
759 #ifndef debug_printf_list
760 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
763 #ifndef debug_printf_subst
764 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
767 #ifndef debug_printf_clean
768 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
769 # define DEBUG_CLEAN 1
771 # define DEBUG_CLEAN 0
775 static void debug_print_strings(const char *prefix, char **vv)
778 fprintf(stderr, "%s:\n", prefix);
780 fprintf(stderr, " '%s'\n", *vv++);
783 # define debug_print_strings(prefix, vv) ((void)0)
787 /* Leak hunting. Use hush_leaktool.sh for post-processing.
790 static void *xxmalloc(int lineno, size_t size)
792 void *ptr = xmalloc((size + 0xff) & ~0xff);
793 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
796 static void *xxrealloc(int lineno, void *ptr, size_t size)
798 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
799 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
802 static char *xxstrdup(int lineno, const char *str)
804 char *ptr = xstrdup(str);
805 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
808 static void xxfree(void *ptr)
810 fdprintf(2, "free %p\n", ptr);
813 # define xmalloc(s) xxmalloc(__LINE__, s)
814 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
815 # define xstrdup(s) xxstrdup(__LINE__, s)
816 # define free(p) xxfree(p)
820 /* Syntax and runtime errors. They always abort scripts.
821 * In interactive use they usually discard unparsed and/or unexecuted commands
822 * and return to the prompt.
823 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
826 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
827 # define syntax_error(lineno, msg) syntax_error(msg)
828 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
829 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
830 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
831 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
834 static void die_if_script(unsigned lineno, const char *fmt, ...)
839 bb_error_msg("hush.c:%u", lineno);
842 bb_verror_msg(fmt, p, NULL);
844 if (!G_interactive_fd)
848 static void syntax_error(unsigned lineno, const char *msg)
851 die_if_script(lineno, "syntax error: %s", msg);
853 die_if_script(lineno, "syntax error", NULL);
856 static void syntax_error_at(unsigned lineno, const char *msg)
858 die_if_script(lineno, "syntax error at '%s'", msg);
861 static void syntax_error_unterm_str(unsigned lineno, const char *s)
863 die_if_script(lineno, "syntax error: unterminated %s", s);
866 /* It so happens that all such cases are totally fatal
867 * even if shell is interactive: EOF while looking for closing
868 * delimiter. There is nowhere to read stuff from after that,
869 * it's EOF! The only choice is to terminate.
871 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
872 static void syntax_error_unterm_ch(unsigned lineno, char ch)
874 char msg[2] = { ch, '\0' };
875 syntax_error_unterm_str(lineno, msg);
879 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
884 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
888 # undef die_if_script
890 # undef syntax_error_at
891 # undef syntax_error_unterm_ch
892 # undef syntax_error_unterm_str
893 # undef syntax_error_unexpected_ch
895 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
896 # define syntax_error(msg) syntax_error(__LINE__, msg)
897 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
898 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
899 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
900 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
904 #if ENABLE_HUSH_INTERACTIVE
905 static void cmdedit_update_prompt(void);
907 # define cmdedit_update_prompt() ((void)0)
913 /* Replace each \x with x in place, return ptr past NUL. */
914 static char *unbackslash(char *src)
916 char *dst = src = strchrnul(src, '\\');
920 if ((*dst++ = *src++) == '\0')
926 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
947 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
948 v[count1 + count2] = NULL;
951 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
955 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
957 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
958 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
961 #define add_strings_to_strings(strings, add, need_to_dup) \
962 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
965 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
966 static char **add_string_to_strings(char **strings, char *add)
971 return add_strings_to_strings(strings, v, /*dup:*/ 0);
974 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
976 char **ptr = add_string_to_strings(strings, add);
977 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
980 #define add_string_to_strings(strings, add) \
981 xx_add_string_to_strings(__LINE__, strings, add)
984 static void free_strings(char **strings)
999 /* Helpers for setting new $n and restoring them back
1001 typedef struct save_arg_t {
1005 smallint sv_g_malloced;
1008 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1012 sv->sv_argv0 = argv[0];
1013 sv->sv_g_argv = G.global_argv;
1014 sv->sv_g_argc = G.global_argc;
1015 sv->sv_g_malloced = G.global_args_malloced;
1017 argv[0] = G.global_argv[0]; /* retain $0 */
1018 G.global_argv = argv;
1019 G.global_args_malloced = 0;
1027 static void restore_G_args(save_arg_t *sv, char **argv)
1031 if (G.global_args_malloced) {
1032 /* someone ran "set -- arg1 arg2 ...", undo */
1034 while (*++pp) /* note: does not free $0 */
1036 free(G.global_argv);
1038 argv[0] = sv->sv_argv0;
1039 G.global_argv = sv->sv_g_argv;
1040 G.global_argc = sv->sv_g_argc;
1041 G.global_args_malloced = sv->sv_g_malloced;
1045 /* Basic theory of signal handling in shell
1046 * ========================================
1047 * This does not describe what hush does, rather, it is current understanding
1048 * what it _should_ do. If it doesn't, it's a bug.
1049 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1051 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1052 * is finished or backgrounded. It is the same in interactive and
1053 * non-interactive shells, and is the same regardless of whether
1054 * a user trap handler is installed or a shell special one is in effect.
1055 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1056 * backgrounds (i.e. stops) or kills all members of currently running
1059 * Wait builtin in interruptible by signals for which user trap is set
1060 * or by SIGINT in interactive shell.
1062 * Trap handlers will execute even within trap handlers. (right?)
1064 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1065 * except for handlers set to '' (empty string).
1067 * If job control is off, backgrounded commands ("cmd &")
1068 * have SIGINT, SIGQUIT set to SIG_IGN.
1070 * Commands which are run in command substitution ("`cmd`")
1071 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1073 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1074 * by the shell from its parent.
1076 * Signals which differ from SIG_DFL action
1077 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1080 * SIGTERM (interactive): ignore
1081 * SIGHUP (interactive):
1082 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1083 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1084 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1085 * that all pipe members are stopped. Try this in bash:
1086 * while :; do :; done - ^Z does not background it
1087 * (while :; do :; done) - ^Z backgrounds it
1088 * SIGINT (interactive): wait for last pipe, ignore the rest
1089 * of the command line, show prompt. NB: ^C does not send SIGINT
1090 * to interactive shell while shell is waiting for a pipe,
1091 * since shell is bg'ed (is not in foreground process group).
1092 * Example 1: this waits 5 sec, but does not execute ls:
1093 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1094 * Example 2: this does not wait and does not execute ls:
1095 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1096 * Example 3: this does not wait 5 sec, but executes ls:
1097 * "sleep 5; ls -l" + press ^C
1099 * (What happens to signals which are IGN on shell start?)
1100 * (What happens with signal mask on shell start?)
1102 * Implementation in hush
1103 * ======================
1104 * We use in-kernel pending signal mask to determine which signals were sent.
1105 * We block all signals which we don't want to take action immediately,
1106 * i.e. we block all signals which need to have special handling as described
1107 * above, and all signals which have traps set.
1108 * After each pipe execution, we extract any pending signals via sigtimedwait()
1111 * unsigned non_DFL_mask: a mask of such "special" signals
1112 * sigset_t blocked_set: current blocked signal set
1115 * clear bit in blocked_set unless it is also in non_DFL_mask
1116 * "trap 'cmd' SIGxxx":
1117 * set bit in blocked_set (even if 'cmd' is '')
1118 * after [v]fork, if we plan to be a shell:
1119 * unblock signals with special interactive handling
1120 * (child shell is not interactive),
1121 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1122 * after [v]fork, if we plan to exec:
1123 * POSIX says fork clears pending signal mask in child - no need to clear it.
1124 * Restore blocked signal set to one inherited by shell just prior to exec.
1126 * Note: as a result, we do not use signal handlers much. The only uses
1127 * are to count SIGCHLDs
1128 * and to restore tty pgrp on signal-induced exit.
1131 * Standard says "When a subshell is entered, traps that are not being ignored
1132 * are set to the default actions". bash interprets it so that traps which
1133 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1136 SPECIAL_INTERACTIVE_SIGS = 0
1141 SPECIAL_JOB_SIGS = 0
1149 #if ENABLE_HUSH_FAST
1150 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1153 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1159 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1160 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1161 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1162 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1164 /* Restores tty foreground process group, and exits.
1165 * May be called as signal handler for fatal signal
1166 * (will resend signal to itself, producing correct exit state)
1167 * or called directly with -EXITCODE.
1168 * We also call it if xfunc is exiting. */
1169 static void sigexit(int sig) NORETURN;
1170 static void sigexit(int sig)
1172 /* Disable all signals: job control, SIGPIPE, etc. */
1173 sigprocmask_allsigs(SIG_BLOCK);
1175 /* Careful: we can end up here after [v]fork. Do not restore
1176 * tty pgrp then, only top-level shell process does that */
1177 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1178 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1180 /* Not a signal, just exit */
1184 kill_myself_with_sig(sig); /* does not return */
1188 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1189 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1193 /* Restores tty foreground process group, and exits. */
1194 static void hush_exit(int exitcode) NORETURN;
1195 static void hush_exit(int exitcode)
1197 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1198 /* Prevent recursion:
1199 * trap "echo Hi; exit" EXIT; exit
1201 char *argv[] = { NULL, G.traps[0], NULL };
1210 sigexit(- (exitcode & 0xff));
1216 static int check_and_run_traps(int sig)
1218 static const struct timespec zero_timespec;
1219 smalluint save_rcode;
1225 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1230 if (G.traps && G.traps[sig]) {
1231 if (G.traps[sig][0]) {
1232 /* We have user-defined handler */
1233 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1234 save_rcode = G.last_exitcode;
1237 G.last_exitcode = save_rcode;
1238 } /* else: "" trap, ignoring signal */
1241 /* not a trap: special action */
1243 #if ENABLE_HUSH_FAST
1246 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1250 /* Builtin was ^C'ed, make it look prettier: */
1257 /* bash is observed to signal whole process groups,
1258 * not individual processes */
1259 for (job = G.job_list; job; job = job->next) {
1262 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1263 if (kill(- job->pgrp, SIGHUP) == 0)
1264 kill(- job->pgrp, SIGCONT);
1269 default: /* ignored: */
1270 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1278 static const char *get_cwd(int force)
1280 if (force || G.cwd == NULL) {
1281 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1282 * we must not try to free(bb_msg_unknown) */
1283 if (G.cwd == bb_msg_unknown)
1285 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1287 G.cwd = bb_msg_unknown;
1294 * Shell and environment variable support
1296 static struct variable **get_ptr_to_local_var(const char *name)
1298 struct variable **pp;
1299 struct variable *cur;
1304 while ((cur = *pp) != NULL) {
1305 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1312 static struct variable *get_local_var(const char *name)
1314 struct variable **pp = get_ptr_to_local_var(name);
1320 static const char* FAST_FUNC get_local_var_value(const char *name)
1322 struct variable **pp = get_ptr_to_local_var(name);
1324 return strchr((*pp)->varstr, '=') + 1;
1325 if (strcmp(name, "PPID") == 0)
1326 return utoa(G.root_ppid);
1327 // bash compat: UID? EUID?
1328 #if ENABLE_HUSH_RANDOM_SUPPORT
1329 if (strcmp(name, "RANDOM") == 0) {
1330 return utoa(next_random(&G.random_gen));
1336 /* str holds "NAME=VAL" and is expected to be malloced.
1337 * We take ownership of it.
1339 * 0: do not change export flag
1340 * (if creating new variable, flag will be 0)
1341 * 1: set export flag and putenv the variable
1342 * -1: clear export flag and unsetenv the variable
1343 * flg_read_only is set only when we handle -R var=val
1345 #if !BB_MMU && ENABLE_HUSH_LOCAL
1346 /* all params are used */
1347 #elif BB_MMU && ENABLE_HUSH_LOCAL
1348 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1349 set_local_var(str, flg_export, local_lvl)
1350 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1351 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1352 set_local_var(str, flg_export)
1353 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1354 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1355 set_local_var(str, flg_export, flg_read_only)
1357 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1359 struct variable **var_pp;
1360 struct variable *cur;
1364 eq_sign = strchr(str, '=');
1365 if (!eq_sign) { /* not expected to ever happen? */
1370 name_len = eq_sign - str + 1; /* including '=' */
1371 var_pp = &G.top_var;
1372 while ((cur = *var_pp) != NULL) {
1373 if (strncmp(cur->varstr, str, name_len) != 0) {
1374 var_pp = &cur->next;
1377 /* We found an existing var with this name */
1378 if (cur->flg_read_only) {
1382 bb_error_msg("%s: readonly variable", str);
1386 if (flg_export == -1) { // "&& cur->flg_export" ?
1387 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1392 #if ENABLE_HUSH_LOCAL
1393 if (cur->func_nest_level < local_lvl) {
1394 /* New variable is declared as local,
1395 * and existing one is global, or local
1396 * from enclosing function.
1397 * Remove and save old one: */
1398 *var_pp = cur->next;
1399 cur->next = *G.shadowed_vars_pp;
1400 *G.shadowed_vars_pp = cur;
1401 /* bash 3.2.33(1) and exported vars:
1403 * # f() { local z=a; env | grep ^z; }
1409 if (cur->flg_export)
1414 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1419 if (cur->max_len != 0) {
1420 if (cur->max_len >= strlen(str)) {
1421 /* This one is from startup env, reuse space */
1422 strcpy(cur->varstr, str);
1426 /* max_len == 0 signifies "malloced" var, which we can
1427 * (and has to) free */
1431 goto set_str_and_exp;
1434 /* Not found - create new variable struct */
1435 cur = xzalloc(sizeof(*cur));
1436 #if ENABLE_HUSH_LOCAL
1437 cur->func_nest_level = local_lvl;
1439 cur->next = *var_pp;
1445 cur->flg_read_only = flg_read_only;
1448 if (flg_export == 1)
1449 cur->flg_export = 1;
1450 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1451 cmdedit_update_prompt();
1452 if (cur->flg_export) {
1453 if (flg_export == -1) {
1454 cur->flg_export = 0;
1455 /* unsetenv was already done */
1457 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1458 return putenv(cur->varstr);
1464 /* Used at startup and after each cd */
1465 static void set_pwd_var(int exp)
1467 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1468 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1471 static int unset_local_var_len(const char *name, int name_len)
1473 struct variable *cur;
1474 struct variable **var_pp;
1477 return EXIT_SUCCESS;
1478 var_pp = &G.top_var;
1479 while ((cur = *var_pp) != NULL) {
1480 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1481 if (cur->flg_read_only) {
1482 bb_error_msg("%s: readonly variable", name);
1483 return EXIT_FAILURE;
1485 *var_pp = cur->next;
1486 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1487 bb_unsetenv(cur->varstr);
1488 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1489 cmdedit_update_prompt();
1493 return EXIT_SUCCESS;
1495 var_pp = &cur->next;
1497 return EXIT_SUCCESS;
1500 static int unset_local_var(const char *name)
1502 return unset_local_var_len(name, strlen(name));
1505 static void unset_vars(char **strings)
1513 const char *eq = strchrnul(*v, '=');
1514 unset_local_var_len(*v, (int)(eq - *v));
1520 #if ENABLE_SH_MATH_SUPPORT
1521 # define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1522 # define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1523 static char* FAST_FUNC endofname(const char *name)
1531 if (!is_in_name(*p))
1538 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1540 char *var = xasprintf("%s=%s", name, val);
1541 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1546 * Helpers for "var1=val1 var2=val2 cmd" feature
1548 static void add_vars(struct variable *var)
1550 struct variable *next;
1554 var->next = G.top_var;
1556 if (var->flg_export) {
1557 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1558 putenv(var->varstr);
1560 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1566 static struct variable *set_vars_and_save_old(char **strings)
1569 struct variable *old = NULL;
1575 struct variable *var_p;
1576 struct variable **var_pp;
1579 eq = strchr(*s, '=');
1582 var_pp = get_ptr_to_local_var(*s);
1585 /* Remove variable from global linked list */
1587 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1588 *var_pp = var_p->next;
1589 /* Add it to returned list */
1593 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1604 static int FAST_FUNC static_get(struct in_str *i)
1614 static int FAST_FUNC static_peek(struct in_str *i)
1619 #if ENABLE_HUSH_INTERACTIVE
1621 static void cmdedit_update_prompt(void)
1623 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1624 G.PS1 = get_local_var_value("PS1");
1627 G.PS2 = get_local_var_value("PS2");
1635 static const char* setup_prompt_string(int promptmode)
1637 const char *prompt_str;
1638 debug_printf("setup_prompt_string %d ", promptmode);
1639 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1640 /* Set up the prompt */
1641 if (promptmode == 0) { /* PS1 */
1643 /* bash uses $PWD value, even if it is set by user.
1644 * It uses current dir only if PWD is unset.
1645 * We always use current dir. */
1646 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1651 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1652 debug_printf("result '%s'\n", prompt_str);
1656 static void get_user_input(struct in_str *i)
1659 const char *prompt_str;
1661 prompt_str = setup_prompt_string(i->promptmode);
1662 # if ENABLE_FEATURE_EDITING
1663 /* Enable command line editing only while a command line
1664 * is actually being read */
1667 /* buglet: SIGINT will not make new prompt to appear _at once_,
1668 * only after <Enter>. (^C will work) */
1669 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1670 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1671 check_and_run_traps(0);
1672 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1673 i->eof_flag = (r < 0);
1674 if (i->eof_flag) { /* EOF/error detected */
1675 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1676 G.user_input_buf[1] = '\0';
1681 fputs(prompt_str, stdout);
1683 G.user_input_buf[0] = r = fgetc(i->file);
1684 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1685 //do we need check_and_run_traps(0)? (maybe only if stdin)
1686 } while (G.flag_SIGINT);
1687 i->eof_flag = (r == EOF);
1689 i->p = G.user_input_buf;
1692 #endif /* INTERACTIVE */
1694 /* This is the magic location that prints prompts
1695 * and gets data back from the user */
1696 static int FAST_FUNC file_get(struct in_str *i)
1700 /* If there is data waiting, eat it up */
1701 if (i->p && *i->p) {
1702 #if ENABLE_HUSH_INTERACTIVE
1706 if (i->eof_flag && !*i->p)
1708 /* note: ch is never NUL */
1710 /* need to double check i->file because we might be doing something
1711 * more complicated by now, like sourcing or substituting. */
1712 #if ENABLE_HUSH_INTERACTIVE
1713 if (G_interactive_fd && i->promptme && i->file == stdin) {
1716 } while (!*i->p); /* need non-empty line */
1717 i->promptmode = 1; /* PS2 */
1722 do ch = fgetc(i->file); while (ch == '\0');
1724 debug_printf("file_get: got '%c' %d\n", ch, ch);
1725 #if ENABLE_HUSH_INTERACTIVE
1732 /* All callers guarantee this routine will never
1733 * be used right after a newline, so prompting is not needed.
1735 static int FAST_FUNC file_peek(struct in_str *i)
1738 if (i->p && *i->p) {
1739 if (i->eof_flag && !i->p[1])
1742 /* note: ch is never NUL */
1744 do ch = fgetc(i->file); while (ch == '\0');
1745 i->eof_flag = (ch == EOF);
1746 i->peek_buf[0] = ch;
1747 i->peek_buf[1] = '\0';
1749 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1753 static void setup_file_in_str(struct in_str *i, FILE *f)
1755 i->peek = file_peek;
1757 #if ENABLE_HUSH_INTERACTIVE
1759 i->promptmode = 0; /* PS1 */
1765 static void setup_string_in_str(struct in_str *i, const char *s)
1767 i->peek = static_peek;
1768 i->get = static_get;
1769 #if ENABLE_HUSH_INTERACTIVE
1771 i->promptmode = 0; /* PS1 */
1781 #define B_CHUNK (32 * sizeof(char*))
1783 static void o_reset_to_empty_unquoted(o_string *o)
1791 static void o_free(o_string *o)
1794 memset(o, 0, sizeof(*o));
1797 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1802 static void o_grow_by(o_string *o, int len)
1804 if (o->length + len > o->maxlen) {
1805 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1806 o->data = xrealloc(o->data, 1 + o->maxlen);
1810 static void o_addchr(o_string *o, int ch)
1812 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1814 o->data[o->length] = ch;
1816 o->data[o->length] = '\0';
1819 static void o_addblock(o_string *o, const char *str, int len)
1822 memcpy(&o->data[o->length], str, len);
1824 o->data[o->length] = '\0';
1827 static void o_addstr(o_string *o, const char *str)
1829 o_addblock(o, str, strlen(str));
1833 static void nommu_addchr(o_string *o, int ch)
1839 # define nommu_addchr(o, str) ((void)0)
1842 static void o_addstr_with_NUL(o_string *o, const char *str)
1844 o_addblock(o, str, strlen(str) + 1);
1847 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1852 && (*str != '*' && *str != '?' && *str != '[')
1860 #undef HUSH_BRACE_EXP
1862 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1863 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1864 * Apparently, on unquoted $v bash still does globbing
1865 * ("v='*.txt'; echo $v" prints all .txt files),
1866 * but NOT brace expansion! Thus, there should be TWO independent
1867 * quoting mechanisms on $v expansion side: one protects
1868 * $v from brace expansion, and other additionally protects "$v" against globbing.
1869 * We have only second one.
1872 #ifdef HUSH_BRACE_EXP
1873 # define MAYBE_BRACES "{}"
1875 # define MAYBE_BRACES ""
1878 /* My analysis of quoting semantics tells me that state information
1879 * is associated with a destination, not a source.
1881 static void o_addqchr(o_string *o, int ch)
1884 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1889 o->data[o->length] = '\\';
1892 o->data[o->length] = ch;
1894 o->data[o->length] = '\0';
1897 static void o_addQchr(o_string *o, int ch)
1900 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1902 o->data[o->length] = '\\';
1906 o->data[o->length] = ch;
1908 o->data[o->length] = '\0';
1911 static void o_addQstr(o_string *o, const char *str, int len)
1914 o_addblock(o, str, len);
1920 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1921 if (ordinary_cnt > len) /* paranoia */
1923 o_addblock(o, str, ordinary_cnt);
1924 if (ordinary_cnt == len)
1926 str += ordinary_cnt;
1927 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1931 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1933 o->data[o->length] = '\\';
1937 o->data[o->length] = ch;
1939 o->data[o->length] = '\0';
1943 /* A special kind of o_string for $VAR and `cmd` expansion.
1944 * It contains char* list[] at the beginning, which is grown in 16 element
1945 * increments. Actual string data starts at the next multiple of 16 * (char*).
1946 * list[i] contains an INDEX (int!) into this string data.
1947 * It means that if list[] needs to grow, data needs to be moved higher up
1948 * but list[i]'s need not be modified.
1949 * NB: remembering how many list[i]'s you have there is crucial.
1950 * o_finalize_list() operation post-processes this structure - calculates
1951 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1953 #if DEBUG_EXPAND || DEBUG_GLOB
1954 static void debug_print_list(const char *prefix, o_string *o, int n)
1956 char **list = (char**)o->data;
1957 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1961 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1962 prefix, list, n, string_start, o->length, o->maxlen);
1965 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1966 o->data + (int)list[i] + string_start,
1967 o->data + (int)list[i] + string_start);
1971 const char *p = o->data + (int)list[n - 1] + string_start;
1973 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1977 # define debug_print_list(prefix, o, n) ((void)0)
1980 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1981 * in list[n] so that it points past last stored byte so far.
1982 * It returns n+1. */
1983 static int o_save_ptr_helper(o_string *o, int n)
1985 char **list = (char**)o->data;
1989 if (!o->has_empty_slot) {
1990 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1991 string_len = o->length - string_start;
1992 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1993 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1994 /* list[n] points to string_start, make space for 16 more pointers */
1995 o->maxlen += 0x10 * sizeof(list[0]);
1996 o->data = xrealloc(o->data, o->maxlen + 1);
1997 list = (char**)o->data;
1998 memmove(list + n + 0x10, list + n, string_len);
1999 o->length += 0x10 * sizeof(list[0]);
2001 debug_printf_list("list[%d]=%d string_start=%d\n",
2002 n, string_len, string_start);
2005 /* We have empty slot at list[n], reuse without growth */
2006 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2007 string_len = o->length - string_start;
2008 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2009 n, string_len, string_start);
2010 o->has_empty_slot = 0;
2012 list[n] = (char*)(ptrdiff_t)string_len;
2016 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2017 static int o_get_last_ptr(o_string *o, int n)
2019 char **list = (char**)o->data;
2020 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2022 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2025 #ifdef HUSH_BRACE_EXP
2026 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2027 * first, it processes even {a} (no commas), second,
2028 * I didn't manage to make it return strings when they don't match
2029 * existing files. Need to re-implement it.
2033 static int glob_needed(const char *s)
2042 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2048 /* Return pointer to next closing brace or to comma */
2049 static const char *next_brace_sub(const char *cp)
2053 while (*cp != '\0') {
2060 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2062 if (*cp++ == '{') /*}*/
2066 return *cp != '\0' ? cp : NULL;
2068 /* Recursive brace globber. Note: may garble pattern[]. */
2069 static int glob_brace(char *pattern, o_string *o, int n)
2071 char *new_pattern_buf;
2078 debug_printf_glob("glob_brace('%s')\n", pattern);
2084 if (*begin == '{') /*}*/ {
2085 /* Find the first sub-pattern and at the same time
2086 * find the rest after the closing brace */
2087 next = next_brace_sub(begin);
2089 /* An illegal expression */
2092 /*{*/ if (*next == '}') {
2093 /* "{abc}" with no commas - illegal
2094 * brace expr, disregard and skip it */
2100 if (*begin == '\\' && begin[1] != '\0')
2104 debug_printf_glob("begin:%s\n", begin);
2105 debug_printf_glob("next:%s\n", next);
2107 /* Now find the end of the whole brace expression */
2109 /*{*/ while (*rest != '}') {
2110 rest = next_brace_sub(rest);
2112 /* An illegal expression */
2115 debug_printf_glob("rest:%s\n", rest);
2117 rest_len = strlen(++rest) + 1;
2119 /* We are sure the brace expression is well-formed */
2121 /* Allocate working buffer large enough for our work */
2122 new_pattern_buf = xmalloc(strlen(pattern));
2124 /* We have a brace expression. BEGIN points to the opening {,
2125 * NEXT points past the terminator of the first element, and REST
2126 * points past the final }. We will accumulate result names from
2127 * recursive runs for each brace alternative in the buffer using
2132 /* Construct the new glob expression */
2135 mempcpy(new_pattern_buf,
2136 /* We know the prefix for all sub-patterns */
2137 pattern, begin - pattern),
2141 /* Note: glob_brace() may garble new_pattern_buf[].
2142 * That's why we re-copy prefix every time (1st memcpy above).
2144 n = glob_brace(new_pattern_buf, o, n);
2145 /*{*/ if (*next == '}') {
2146 /* We saw the last entry */
2150 next = next_brace_sub(next);
2152 free(new_pattern_buf);
2160 memset(&globdata, 0, sizeof(globdata));
2161 gr = glob(pattern, 0, NULL, &globdata);
2162 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2164 if (gr == GLOB_NOMATCH) {
2165 globfree(&globdata);
2166 /* NB: garbles parameter */
2167 unbackslash(pattern);
2168 o_addstr_with_NUL(o, pattern);
2169 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2170 return o_save_ptr_helper(o, n);
2172 if (gr == GLOB_NOSPACE)
2173 bb_error_msg_and_die(bb_msg_memory_exhausted);
2174 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2175 * but we didn't specify it. Paranoia again. */
2176 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2178 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2179 char **argv = globdata.gl_pathv;
2181 o_addstr_with_NUL(o, *argv);
2182 n = o_save_ptr_helper(o, n);
2188 globfree(&globdata);
2192 /* Performs globbing on last list[],
2193 * saving each result as a new list[].
2195 static int o_glob(o_string *o, int n)
2197 char *pattern, *copy;
2199 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2201 return o_save_ptr_helper(o, n);
2202 pattern = o->data + o_get_last_ptr(o, n);
2203 debug_printf_glob("glob pattern '%s'\n", pattern);
2204 if (!glob_needed(pattern)) {
2205 /* unbackslash last string in o in place, fix length */
2206 o->length = unbackslash(pattern) - o->data;
2207 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2208 return o_save_ptr_helper(o, n);
2211 copy = xstrdup(pattern);
2212 /* "forget" pattern in o */
2213 o->length = pattern - o->data;
2214 n = glob_brace(copy, o, n);
2217 debug_print_list("o_glob returning", o, n);
2221 #else /* !HUSH_BRACE_EXP */
2224 static int glob_needed(const char *s)
2233 if (*s == '*' || *s == '[' || *s == '?')
2239 /* Performs globbing on last list[],
2240 * saving each result as a new list[].
2242 static int o_glob(o_string *o, int n)
2248 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2250 return o_save_ptr_helper(o, n);
2251 pattern = o->data + o_get_last_ptr(o, n);
2252 debug_printf_glob("glob pattern '%s'\n", pattern);
2253 if (!glob_needed(pattern)) {
2255 /* unbackslash last string in o in place, fix length */
2256 o->length = unbackslash(pattern) - o->data;
2257 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2258 return o_save_ptr_helper(o, n);
2261 memset(&globdata, 0, sizeof(globdata));
2262 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2263 * If we glob "*.\*" and don't find anything, we need
2264 * to fall back to using literal "*.*", but GLOB_NOCHECK
2265 * will return "*.\*"!
2267 gr = glob(pattern, 0, NULL, &globdata);
2268 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2270 if (gr == GLOB_NOMATCH) {
2271 globfree(&globdata);
2274 if (gr == GLOB_NOSPACE)
2275 bb_error_msg_and_die(bb_msg_memory_exhausted);
2276 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2277 * but we didn't specify it. Paranoia again. */
2278 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2280 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2281 char **argv = globdata.gl_pathv;
2282 /* "forget" pattern in o */
2283 o->length = pattern - o->data;
2285 o_addstr_with_NUL(o, *argv);
2286 n = o_save_ptr_helper(o, n);
2292 globfree(&globdata);
2294 debug_print_list("o_glob returning", o, n);
2298 #endif /* !HUSH_BRACE_EXP */
2300 /* If o->o_glob == 1, glob the string so far remembered.
2301 * Otherwise, just finish current list[] and start new */
2302 static int o_save_ptr(o_string *o, int n)
2304 if (o->o_glob) { /* if globbing is requested */
2305 /* If o->has_empty_slot, list[n] was already globbed
2306 * (if it was requested back then when it was filled)
2307 * so don't do that again! */
2308 if (!o->has_empty_slot)
2309 return o_glob(o, n); /* o_save_ptr_helper is inside */
2311 return o_save_ptr_helper(o, n);
2314 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2315 static char **o_finalize_list(o_string *o, int n)
2320 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2322 debug_print_list("finalized", o, n);
2323 debug_printf_expand("finalized n:%d\n", n);
2324 list = (char**)o->data;
2325 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2329 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2335 /* Expansion can recurse */
2336 #if ENABLE_HUSH_TICK
2337 static int process_command_subs(o_string *dest, const char *s);
2339 static char *expand_string_to_string(const char *str);
2341 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2342 parse_stream_dquoted(dest, input, dquote_end)
2344 static int parse_stream_dquoted(o_string *as_string,
2346 struct in_str *input,
2349 /* expand_strvec_to_strvec() takes a list of strings, expands
2350 * all variable references within and returns a pointer to
2351 * a list of expanded strings, possibly with larger number
2352 * of strings. (Think VAR="a b"; echo $VAR).
2353 * This new list is allocated as a single malloc block.
2354 * NULL-terminated list of char* pointers is at the beginning of it,
2355 * followed by strings themself.
2356 * Caller can deallocate entire list by single free(list). */
2358 /* Store given string, finalizing the word and starting new one whenever
2359 * we encounter IFS char(s). This is used for expanding variable values.
2360 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2361 static int expand_on_ifs(o_string *output, int n, const char *str)
2364 int word_len = strcspn(str, G.ifs);
2366 if (output->o_escape || !output->o_glob)
2367 o_addQstr(output, str, word_len);
2368 else /* protect backslashes against globbing up :) */
2369 o_addblock_duplicate_backslash(output, str, word_len);
2372 if (!*str) /* EOL - do not finalize word */
2374 o_addchr(output, '\0');
2375 debug_print_list("expand_on_ifs", output, n);
2376 n = o_save_ptr(output, n);
2377 str += strspn(str, G.ifs); /* skip ifs chars */
2379 debug_print_list("expand_on_ifs[1]", output, n);
2383 /* Helper to expand $((...)) and heredoc body. These act as if
2384 * they are in double quotes, with the exception that they are not :).
2385 * Just the rules are similar: "expand only $var and `cmd`"
2387 * Returns malloced string.
2388 * As an optimization, we return NULL if expansion is not needed.
2390 static char *expand_pseudo_dquoted(const char *str)
2393 struct in_str input;
2394 o_string dest = NULL_O_STRING;
2396 if (strchr(str, '$') == NULL
2397 #if ENABLE_HUSH_TICK
2398 && strchr(str, '`') == NULL
2404 /* We need to expand. Example:
2405 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2407 setup_string_in_str(&input, str);
2408 parse_stream_dquoted(NULL, &dest, &input, EOF);
2409 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2410 exp_str = expand_string_to_string(dest.data);
2411 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2412 o_free_unsafe(&dest);
2416 #if ENABLE_SH_MATH_SUPPORT
2417 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
2419 arith_eval_hooks_t hooks;
2423 hooks.lookupvar = get_local_var_value;
2424 hooks.setvar = set_local_var_from_halves;
2425 hooks.endofname = endofname;
2426 exp_str = expand_pseudo_dquoted(arg);
2427 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
2433 /* Expand all variable references in given string, adding words to list[]
2434 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2435 * to be filled). This routine is extremely tricky: has to deal with
2436 * variables/parameters with whitespace, $* and $@, and constructs like
2437 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2438 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2440 /* or_mask is either 0 (normal case) or 0x80 -
2441 * expansion of right-hand side of assignment == 1-element expand.
2442 * It will also do no globbing, and thus we must not backslash-quote!
2449 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2450 debug_print_list("expand_vars_to_list", output, n);
2451 n = o_save_ptr(output, n);
2452 debug_print_list("expand_vars_to_list[0]", output, n);
2454 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2457 char *to_be_freed = NULL;
2458 const char *val = NULL;
2459 #if ENABLE_HUSH_TICK
2460 o_string subst_result = NULL_O_STRING;
2462 #if ENABLE_SH_MATH_SUPPORT
2463 char arith_buf[sizeof(arith_t)*3 + 2];
2465 o_addblock(output, arg, p - arg);
2466 debug_print_list("expand_vars_to_list[1]", output, n);
2468 p = strchr(p, SPECIAL_VAR_SYMBOL);
2470 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2471 /* "$@" is special. Even if quoted, it can still
2472 * expand to nothing (not even an empty string) */
2473 if ((first_ch & 0x7f) != '@')
2474 ored_ch |= first_ch;
2476 switch (first_ch & 0x7f) {
2477 /* Highest bit in first_ch indicates that var is double-quoted */
2481 if (!G.global_argv[i])
2483 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2484 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2485 smallint sv = output->o_escape;
2486 /* unquoted var's contents should be globbed, so don't escape */
2487 output->o_escape = 0;
2488 while (G.global_argv[i]) {
2489 n = expand_on_ifs(output, n, G.global_argv[i]);
2490 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2491 if (G.global_argv[i++][0] && G.global_argv[i]) {
2492 /* this argv[] is not empty and not last:
2493 * put terminating NUL, start new word */
2494 o_addchr(output, '\0');
2495 debug_print_list("expand_vars_to_list[2]", output, n);
2496 n = o_save_ptr(output, n);
2497 debug_print_list("expand_vars_to_list[3]", output, n);
2500 output->o_escape = sv;
2502 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2503 * and in this case should treat it like '$*' - see 'else...' below */
2504 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2506 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2507 if (++i >= G.global_argc)
2509 o_addchr(output, '\0');
2510 debug_print_list("expand_vars_to_list[4]", output, n);
2511 n = o_save_ptr(output, n);
2513 } else { /* quoted $*: add as one word */
2515 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2516 if (!G.global_argv[++i])
2519 o_addchr(output, G.ifs[0]);
2523 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2524 /* "Empty variable", used to make "" etc to not disappear */
2528 #if ENABLE_HUSH_TICK
2529 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2532 /* Can't just stuff it into output o_string,
2533 * expanded result may need to be globbed
2534 * and $IFS-splitted */
2535 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2536 G.last_exitcode = process_command_subs(&subst_result, arg);
2537 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2538 val = subst_result.data;
2541 #if ENABLE_SH_MATH_SUPPORT
2542 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2546 arg++; /* skip '+' */
2547 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2548 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2549 res = expand_and_evaluate_arith(arg, &errcode);
2552 const char *msg = "error in arithmetic";
2555 msg = "exponent less than 0";
2558 msg = "divide by 0";
2561 msg = "expression recursion loop detected";
2566 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2567 sprintf(arith_buf, arith_t_fmt, res);
2572 default: { /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2576 char exp_save = exp_save; /* for compiler */
2577 char *exp_saveptr; /* points to expansion operator */
2578 char *exp_word = exp_word; /* for compiler */
2582 exp_saveptr = arg[1] ? strchr("%#:-=+?", arg[1]) : NULL;
2583 first_char = arg[0] = first_ch & 0x7f;
2586 if (first_char == '#' && arg[1] && !exp_saveptr) {
2587 /* handle length expansion ${#var} */
2591 /* maybe handle parameter expansion */
2592 if (exp_saveptr /* if 2nd char is one of expansion operators */
2593 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
2595 /* ${?:0}, ${#[:]%0} etc */
2596 exp_saveptr = var + 1;
2598 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
2599 exp_saveptr = var+1 + strcspn(var+1, "%#:-=+?");
2601 exp_op = exp_save = *exp_saveptr;
2603 exp_word = exp_saveptr + 1;
2604 if (exp_op == ':') {
2605 exp_op = *exp_word++;
2606 if (ENABLE_HUSH_BASH_COMPAT
2607 && (exp_op == '\0' || !strchr("%#:-=+?"+3, exp_op))
2609 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
2614 *exp_saveptr = '\0';
2615 } /* else: it's not an expansion op, but bare ${var} */
2618 /* lookup the variable in question */
2619 if (isdigit(var[0])) {
2620 /* parse_dollar() should have vetted var for us */
2622 if (i < G.global_argc)
2623 val = G.global_argv[i];
2624 /* else val remains NULL: $N with too big N */
2628 val = utoa(G.root_pid);
2630 case '!': /* bg pid */
2631 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2633 case '?': /* exitcode */
2634 val = utoa(G.last_exitcode);
2636 case '#': /* argc */
2637 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2640 val = get_local_var_value(var);
2644 /* handle any expansions */
2645 if (exp_op == 'L') {
2646 debug_printf_expand("expand: length(%s)=", val);
2647 val = utoa(val ? strlen(val) : 0);
2648 debug_printf_expand("%s\n", val);
2649 } else if (exp_op) {
2650 if (exp_op == '%' || exp_op == '#') {
2651 /* Standard-mandated substring removal ops:
2652 * ${parameter%word} - remove smallest suffix pattern
2653 * ${parameter%%word} - remove largest suffix pattern
2654 * ${parameter#word} - remove smallest prefix pattern
2655 * ${parameter##word} - remove largest prefix pattern
2657 * Word is expanded to produce a glob pattern.
2658 * Then var's value is matched to it and matching part removed.
2663 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2664 if (exp_op == *exp_word) /* ## or %% */
2666 val = to_be_freed = xstrdup(val);
2668 char *exp_exp_word = expand_pseudo_dquoted(exp_word);
2670 exp_word = exp_exp_word;
2671 loc = scan(to_be_freed, exp_word, match_at_left);
2672 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
2673 // exp_op, to_be_freed, exp_word, loc);
2676 if (loc) { /* match was found */
2677 if (match_at_left) /* # or ## */
2683 } else if (exp_op == ':') {
2684 #if ENABLE_HUSH_BASH_COMPAT
2685 /* It's ${var:N[:M]} bashism.
2686 * Note that in encoded form it has TWO parts:
2687 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
2692 beg = expand_and_evaluate_arith(exp_word, &errcode);
2693 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
2694 *p++ = SPECIAL_VAR_SYMBOL;
2696 p = strchr(p, SPECIAL_VAR_SYMBOL);
2698 len = expand_and_evaluate_arith(exp_word, &errcode);
2699 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
2701 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
2702 if (beg < 0) /* bash compat */
2704 debug_printf_varexp("from val:'%s'\n", val);
2705 if (len == 0 || !val || beg >= strlen(val))
2708 /* Paranoia. What if user entered 9999999999999
2709 * which fits in arith_t but not int? */
2712 val = to_be_freed = xstrndup(val + beg, len);
2714 debug_printf_varexp("val:'%s'\n", val);
2718 die_if_script("malformed ${%s:...}", var);
2721 } else { /* one of "-=+?" */
2722 /* Standard-mandated substitution ops:
2723 * ${var?word} - indicate error if unset
2724 * If var is unset, word (or a message indicating it is unset
2725 * if word is null) is written to standard error
2726 * and the shell exits with a non-zero exit status.
2727 * Otherwise, the value of var is substituted.
2728 * ${var-word} - use default value
2729 * If var is unset, word is substituted.
2730 * ${var=word} - assign and use default value
2731 * If var is unset, word is assigned to var.
2732 * In all cases, final value of var is substituted.
2733 * ${var+word} - use alternative value
2734 * If var is unset, null is substituted.
2735 * Otherwise, word is substituted.
2737 * Word is subjected to tilde expansion, parameter expansion,
2738 * command substitution, and arithmetic expansion.
2739 * If word is not needed, it is not expanded.
2741 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2742 * but also treat null var as if it is unset.
2744 int use_word = (!val || ((exp_save == ':') && !val[0]));
2746 use_word = !use_word;
2747 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2748 (exp_save == ':') ? "true" : "false", use_word);
2750 to_be_freed = expand_pseudo_dquoted(exp_word);
2752 exp_word = to_be_freed;
2753 if (exp_op == '?') {
2754 /* mimic bash message */
2755 die_if_script("%s: %s",
2757 exp_word[0] ? exp_word : "parameter null or not set"
2759 //TODO: how interactive bash aborts expansion mid-command?
2764 if (exp_op == '=') {
2765 /* ${var=[word]} or ${var:=[word]} */
2766 if (isdigit(var[0]) || var[0] == '#') {
2767 /* mimic bash message */
2768 die_if_script("$%s: cannot assign in this way", var);
2771 char *new_var = xasprintf("%s=%s", var, val);
2772 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2776 } /* one of "-=+?" */
2778 *exp_saveptr = exp_save;
2782 #if ENABLE_HUSH_TICK
2785 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2786 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2788 /* unquoted var's contents should be globbed, so don't escape */
2789 smallint sv = output->o_escape;
2790 output->o_escape = 0;
2791 n = expand_on_ifs(output, n, val);
2793 output->o_escape = sv;
2795 } else { /* quoted $VAR, val will be appended below */
2796 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2799 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2802 o_addQstr(output, val, strlen(val));
2805 /* Do the check to avoid writing to a const string */
2806 if (*p != SPECIAL_VAR_SYMBOL)
2807 *p = SPECIAL_VAR_SYMBOL;
2809 #if ENABLE_HUSH_TICK
2810 o_free(&subst_result);
2813 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2816 debug_print_list("expand_vars_to_list[a]", output, n);
2817 /* this part is literal, and it was already pre-quoted
2818 * if needed (much earlier), do not use o_addQstr here! */
2819 o_addstr_with_NUL(output, arg);
2820 debug_print_list("expand_vars_to_list[b]", output, n);
2821 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2822 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2825 /* allow to reuse list[n] later without re-growth */
2826 output->has_empty_slot = 1;
2828 o_addchr(output, '\0');
2833 static char **expand_variables(char **argv, int or_mask)
2838 o_string output = NULL_O_STRING;
2840 if (or_mask & 0x100) {
2841 output.o_escape = 1; /* protect against globbing for "$var" */
2842 /* (unquoted $var will temporarily switch it off) */
2849 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2852 debug_print_list("expand_variables", &output, n);
2854 /* output.data (malloced in one block) gets returned in "list" */
2855 list = o_finalize_list(&output, n);
2856 debug_print_strings("expand_variables[1]", list);
2860 static char **expand_strvec_to_strvec(char **argv)
2862 return expand_variables(argv, 0x100);
2865 #if ENABLE_HUSH_BASH_COMPAT
2866 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2868 return expand_variables(argv, 0x80);
2872 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2873 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2878 o_string output = NULL_O_STRING;
2883 int is_var = is_well_formed_var_name(*v, '=');
2884 /* is_var * 0x80: singleword expansion for vars */
2885 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2887 /* Subtle! expand_vars_to_list did not glob last word yet.
2888 * It does this only when fed with further data.
2889 * Therefore we set globbing flags AFTER it, not before:
2892 /* if it is not recognizably abc=...; then: */
2893 output.o_escape = !is_var; /* protect against globbing for "$var" */
2894 /* (unquoted $var will temporarily switch it off) */
2895 output.o_glob = !is_var; /* and indeed do globbing */
2898 debug_print_list("expand_cond", &output, n);
2900 /* output.data (malloced in one block) gets returned in "list" */
2901 list = o_finalize_list(&output, n);
2902 debug_print_strings("expand_cond[1]", list);
2907 /* Used for expansion of right hand of assignments */
2908 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2910 static char *expand_string_to_string(const char *str)
2912 char *argv[2], **list;
2914 argv[0] = (char*)str;
2916 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2918 if (!list[0] || list[1])
2919 bb_error_msg_and_die("BUG in varexp2");
2920 /* actually, just move string 2*sizeof(char*) bytes back */
2921 overlapping_strcpy((char*)list, list[0]);
2922 unbackslash((char*)list);
2923 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2927 /* Used for "eval" builtin */
2928 static char* expand_strvec_to_string(char **argv)
2932 list = expand_variables(argv, 0x80);
2933 /* Convert all NULs to spaces */
2938 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2939 bb_error_msg_and_die("BUG in varexp3");
2940 /* bash uses ' ' regardless of $IFS contents */
2945 overlapping_strcpy((char*)list, list[0]);
2946 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2950 static char **expand_assignments(char **argv, int count)
2954 /* Expand assignments into one string each */
2955 for (i = 0; i < count; i++) {
2956 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2964 void re_execute_shell(char ***to_free, const char *s,
2965 char *g_argv0, char **g_argv,
2966 char **builtin_argv) NORETURN;
2968 static void reset_traps_to_defaults(void)
2970 /* This function is always called in a child shell
2971 * after fork (not vfork, NOMMU doesn't use this function).
2976 /* Child shells are not interactive.
2977 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2978 * Testcase: (while :; do :; done) + ^Z should background.
2979 * Same goes for SIGTERM, SIGHUP, SIGINT.
2981 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2982 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2984 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2985 * Stupid. It can be done with *single* &= op, but we can't use
2986 * the fact that G.blocked_set is implemented as a bitmask
2988 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2992 /* Careful. Only if no trap or trap is not "" */
2993 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2994 sigdelset(&G.blocked_set, sig);
3001 /* Our homegrown sig mask is saner to work with :) */
3002 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
3004 /* Resetting all traps to default except empty ones */
3005 mask = G.non_DFL_mask;
3006 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
3007 if (!G.traps[sig] || !G.traps[sig][0])
3010 G.traps[sig] = NULL;
3011 /* There is no signal for 0 (EXIT) */
3014 /* There was a trap handler, we just removed it.
3015 * But if sig still has non-DFL handling,
3016 * we should not unblock the sig. */
3019 sigdelset(&G.blocked_set, sig);
3021 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
3026 static void re_execute_shell(char ***to_free, const char *s,
3027 char *g_argv0, char **g_argv,
3028 char **builtin_argv) NORETURN;
3029 static void re_execute_shell(char ***to_free, const char *s,
3030 char *g_argv0, char **g_argv,
3031 char **builtin_argv)
3033 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
3034 /* delims + 2 * (number of bytes in printed hex numbers) */
3035 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
3036 char *heredoc_argv[4];
3037 struct variable *cur;
3038 # if ENABLE_HUSH_FUNCTIONS
3039 struct function *funcp;
3043 unsigned long long empty_trap_mask;
3045 if (!g_argv0) { /* heredoc */
3046 argv = heredoc_argv;
3047 argv[0] = (char *) G.argv0_for_re_execing;
3048 argv[1] = (char *) "-<";
3049 argv[2] = (char *) s;
3051 pp = &argv[3]; /* used as pointer to empty environment */
3057 if (pp) while (*pp++)
3060 empty_trap_mask = 0;
3063 for (sig = 1; sig < NSIG; sig++) {
3064 if (G.traps[sig] && !G.traps[sig][0])
3065 empty_trap_mask |= 1LL << sig;
3069 sprintf(param_buf, NOMMU_HACK_FMT
3070 , (unsigned) G.root_pid
3071 , (unsigned) G.root_ppid
3072 , (unsigned) G.last_bg_pid
3073 , (unsigned) G.last_exitcode
3076 IF_HUSH_LOOPS(, G.depth_of_loop)
3078 # undef NOMMU_HACK_FMT
3079 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3080 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3083 for (cur = G.top_var; cur; cur = cur->next) {
3084 if (!cur->flg_export || cur->flg_read_only)
3087 # if ENABLE_HUSH_FUNCTIONS
3088 for (funcp = G.top_func; funcp; funcp = funcp->next)
3094 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3095 *pp++ = (char *) G.argv0_for_re_execing;
3097 for (cur = G.top_var; cur; cur = cur->next) {
3098 if (cur->varstr == hush_version_str)
3100 if (cur->flg_read_only) {
3101 *pp++ = (char *) "-R";
3102 *pp++ = cur->varstr;
3103 } else if (!cur->flg_export) {
3104 *pp++ = (char *) "-V";
3105 *pp++ = cur->varstr;
3108 # if ENABLE_HUSH_FUNCTIONS
3109 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3110 *pp++ = (char *) "-F";
3111 *pp++ = funcp->name;
3112 *pp++ = funcp->body_as_string;
3115 /* We can pass activated traps here. Say, -Tnn:trap_string
3117 * However, POSIX says that subshells reset signals with traps
3119 * I tested bash-3.2 and it not only does that with true subshells
3120 * of the form ( list ), but with any forked children shells.
3121 * I set trap "echo W" WINCH; and then tried:
3123 * { echo 1; sleep 20; echo 2; } &
3124 * while true; do echo 1; sleep 20; echo 2; break; done &
3125 * true | { echo 1; sleep 20; echo 2; } | cat
3127 * In all these cases sending SIGWINCH to the child shell
3128 * did not run the trap. If I add trap "echo V" WINCH;
3129 * _inside_ group (just before echo 1), it works.
3131 * I conclude it means we don't need to pass active traps here.
3132 * Even if we would use signal handlers instead of signal masking
3133 * in order to implement trap handling,
3134 * exec syscall below resets signals to SIG_DFL for us.
3136 *pp++ = (char *) "-c";
3139 while (*++builtin_argv)
3140 *pp++ = *builtin_argv;
3141 *pp++ = (char *) "";
3146 /* *pp = NULL; - is already there */
3150 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3151 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3152 execve(bb_busybox_exec_path, argv, pp);
3153 /* Fallback. Useful for init=/bin/hush usage etc */
3154 if (argv[0][0] == '/')
3155 execve(argv[0], argv, pp);
3156 xfunc_error_retval = 127;
3157 bb_error_msg_and_die("can't re-execute the shell");
3159 #endif /* !BB_MMU */
3162 static void setup_heredoc(struct redir_struct *redir)
3164 struct fd_pair pair;
3167 /* the _body_ of heredoc (misleading field name) */
3168 const char *heredoc = redir->rd_filename;
3175 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3176 expanded = expand_pseudo_dquoted(heredoc);
3180 len = strlen(heredoc);
3182 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3184 xmove_fd(pair.rd, redir->rd_fd);
3186 /* Try writing without forking. Newer kernels have
3187 * dynamically growing pipes. Must use non-blocking write! */
3190 written = write(pair.wr, heredoc, len);
3201 ndelay_off(pair.wr);
3203 /* Okay, pipe buffer was not big enough */
3204 /* Note: we must not create a stray child (bastard? :)
3205 * for the unsuspecting parent process. Child creates a grandchild
3206 * and exits before parent execs the process which consumes heredoc
3207 * (that exec happens after we return from this function) */
3213 bb_perror_msg_and_die("vfork");
3216 disable_restore_tty_pgrp_on_exit();
3217 pid = BB_MMU ? fork() : vfork();
3219 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3223 close(redir->rd_fd); /* read side of the pipe */
3225 full_write(pair.wr, heredoc, len); /* may loop or block */
3228 /* Delegate blocking writes to another process */
3229 xmove_fd(pair.wr, STDOUT_FILENO);
3230 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3234 #if ENABLE_HUSH_FAST
3236 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3238 enable_restore_tty_pgrp_on_exit();
3244 wait(NULL); /* wait till child has died */
3247 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3248 * and stderr if they are redirected. */
3249 static int setup_redirects(struct command *prog, int squirrel[])
3252 struct redir_struct *redir;
3254 for (redir = prog->redirects; redir; redir = redir->next) {
3255 if (redir->rd_type == REDIRECT_HEREDOC2) {
3256 /* rd_fd<<HERE case */
3257 if (squirrel && redir->rd_fd < 3
3258 && squirrel[redir->rd_fd] < 0
3260 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3262 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3264 debug_printf_parse("set heredoc '%s'\n",
3265 redir->rd_filename);
3266 setup_heredoc(redir);
3270 if (redir->rd_dup == REDIRFD_TO_FILE) {
3271 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3273 if (redir->rd_filename == NULL) {
3274 /* Something went wrong in the parse.
3275 * Pretend it didn't happen */
3276 bb_error_msg("bug in redirect parse");
3279 mode = redir_table[redir->rd_type].mode;
3280 p = expand_string_to_string(redir->rd_filename);
3281 openfd = open_or_warn(p, mode);
3284 /* this could get lost if stderr has been redirected, but
3285 * bash and ash both lose it as well (though zsh doesn't!) */
3286 //what the above comment tries to say?
3290 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3291 openfd = redir->rd_dup;
3294 if (openfd != redir->rd_fd) {
3295 if (squirrel && redir->rd_fd < 3
3296 && squirrel[redir->rd_fd] < 0
3298 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3300 if (openfd == REDIRFD_CLOSE) {
3301 /* "n>-" means "close me" */
3302 close(redir->rd_fd);
3304 xdup2(openfd, redir->rd_fd);
3305 if (redir->rd_dup == REDIRFD_TO_FILE)
3313 static void restore_redirects(int squirrel[])
3316 for (i = 0; i < 3; i++) {
3319 /* We simply die on error */
3326 static void free_pipe_list(struct pipe *head);
3328 /* Return code is the exit status of the pipe */
3329 static void free_pipe(struct pipe *pi)
3332 struct command *command;
3333 struct redir_struct *r, *rnext;
3336 if (pi->stopped_cmds > 0) /* why? */
3338 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3339 for (i = 0; i < pi->num_cmds; i++) {
3340 command = &pi->cmds[i];
3341 debug_printf_clean(" command %d:\n", i);
3342 if (command->argv) {
3343 for (a = 0, p = command->argv; *p; a++, p++) {
3344 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3346 free_strings(command->argv);
3347 command->argv = NULL;
3349 /* not "else if": on syntax error, we may have both! */
3350 if (command->group) {
3351 debug_printf_clean(" begin group (cmd_type:%d)\n",
3353 free_pipe_list(command->group);
3354 debug_printf_clean(" end group\n");
3355 command->group = NULL;
3357 /* else is crucial here.
3358 * If group != NULL, child_func is meaningless */
3359 #if ENABLE_HUSH_FUNCTIONS
3360 else if (command->child_func) {
3361 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3362 command->child_func->parent_cmd = NULL;
3366 free(command->group_as_string);
3367 command->group_as_string = NULL;
3369 for (r = command->redirects; r; r = rnext) {
3370 debug_printf_clean(" redirect %d%s",
3371 r->rd_fd, redir_table[r->rd_type].descrip);
3372 /* guard against the case >$FOO, where foo is unset or blank */
3373 if (r->rd_filename) {
3374 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3375 free(r->rd_filename);
3376 r->rd_filename = NULL;
3378 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3382 command->redirects = NULL;
3384 free(pi->cmds); /* children are an array, they get freed all at once */
3392 static void free_pipe_list(struct pipe *head)
3394 struct pipe *pi, *next;
3396 for (pi = head; pi; pi = next) {
3398 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3401 debug_printf_clean("pipe followup code %d\n", pi->followup);
3403 /*pi->next = NULL;*/
3409 static int run_list(struct pipe *pi);
3411 #define parse_stream(pstring, input, end_trigger) \
3412 parse_stream(input, end_trigger)
3414 static struct pipe *parse_stream(char **pstring,
3415 struct in_str *input,
3417 static void parse_and_run_string(const char *s);
3420 static char *find_in_path(const char *arg)
3423 const char *PATH = get_local_var_value("PATH");
3429 const char *end = strchrnul(PATH, ':');
3430 int sz = end - PATH; /* must be int! */
3434 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3436 /* We have xxx::yyyy in $PATH,
3437 * it means "use current dir" */
3440 if (access(ret, F_OK) == 0)
3453 static const struct built_in_command* find_builtin_helper(const char *name,
3454 const struct built_in_command *x,
3455 const struct built_in_command *end)
3458 if (strcmp(name, x->b_cmd) != 0) {
3462 debug_printf_exec("found builtin '%s'\n", name);
3467 static const struct built_in_command* find_builtin1(const char *name)
3469 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3471 static const struct built_in_command* find_builtin(const char *name)
3473 const struct built_in_command *x = find_builtin1(name);
3476 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3479 #if ENABLE_HUSH_FUNCTIONS
3480 static struct function **find_function_slot(const char *name)
3482 struct function **funcpp = &G.top_func;
3484 if (strcmp(name, (*funcpp)->name) == 0) {
3487 funcpp = &(*funcpp)->next;
3492 static const struct function *find_function(const char *name)
3494 const struct function *funcp = *find_function_slot(name);
3496 debug_printf_exec("found function '%s'\n", name);
3500 /* Note: takes ownership on name ptr */
3501 static struct function *new_function(char *name)
3503 struct function **funcpp = find_function_slot(name);
3504 struct function *funcp = *funcpp;
3506 if (funcp != NULL) {
3507 struct command *cmd = funcp->parent_cmd;
3508 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3510 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3512 /* Note: if !funcp->body, do not free body_as_string!
3513 * This is a special case of "-F name body" function:
3514 * body_as_string was not malloced! */
3516 free_pipe_list(funcp->body);
3518 free(funcp->body_as_string);
3522 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3523 cmd->argv[0] = funcp->name;
3524 cmd->group = funcp->body;
3526 cmd->group_as_string = funcp->body_as_string;
3530 debug_printf_exec("remembering new function '%s'\n", name);
3531 funcp = *funcpp = xzalloc(sizeof(*funcp));
3532 /*funcp->next = NULL;*/
3539 static void unset_func(const char *name)
3541 struct function **funcpp = find_function_slot(name);
3542 struct function *funcp = *funcpp;
3544 if (funcp != NULL) {
3545 debug_printf_exec("freeing function '%s'\n", funcp->name);
3546 *funcpp = funcp->next;
3547 /* funcp is unlinked now, deleting it.
3548 * Note: if !funcp->body, the function was created by
3549 * "-F name body", do not free ->body_as_string
3550 * and ->name as they were not malloced. */
3552 free_pipe_list(funcp->body);
3555 free(funcp->body_as_string);
3563 #define exec_function(to_free, funcp, argv) \
3564 exec_function(funcp, argv)
3566 static void exec_function(char ***to_free,
3567 const struct function *funcp,
3568 char **argv) NORETURN;
3569 static void exec_function(char ***to_free,
3570 const struct function *funcp,
3576 argv[0] = G.global_argv[0];
3577 G.global_argv = argv;
3581 /* On MMU, funcp->body is always non-NULL */
3582 n = run_list(funcp->body);
3586 re_execute_shell(to_free,
3587 funcp->body_as_string,
3594 static int run_function(const struct function *funcp, char **argv)
3600 save_and_replace_G_args(&sv, argv);
3602 /* "we are in function, ok to use return" */
3603 sv_flg = G.flag_return_in_progress;
3604 G.flag_return_in_progress = -1;
3605 # if ENABLE_HUSH_LOCAL
3606 G.func_nest_level++;
3609 /* On MMU, funcp->body is always non-NULL */
3612 /* Function defined by -F */
3613 parse_and_run_string(funcp->body_as_string);
3614 rc = G.last_exitcode;
3618 rc = run_list(funcp->body);
3621 # if ENABLE_HUSH_LOCAL
3623 struct variable *var;
3624 struct variable **var_pp;
3626 var_pp = &G.top_var;
3627 while ((var = *var_pp) != NULL) {
3628 if (var->func_nest_level < G.func_nest_level) {
3629 var_pp = &var->next;
3633 if (var->flg_export)
3634 bb_unsetenv(var->varstr);
3635 /* Remove from global list */
3636 *var_pp = var->next;
3642 G.func_nest_level--;
3645 G.flag_return_in_progress = sv_flg;
3647 restore_G_args(&sv, argv);
3651 #endif /* ENABLE_HUSH_FUNCTIONS */
3655 #define exec_builtin(to_free, x, argv) \
3656 exec_builtin(x, argv)
3658 #define exec_builtin(to_free, x, argv) \
3659 exec_builtin(to_free, argv)
3661 static void exec_builtin(char ***to_free,
3662 const struct built_in_command *x,
3663 char **argv) NORETURN;
3664 static void exec_builtin(char ***to_free,
3665 const struct built_in_command *x,
3669 int rcode = x->b_function(argv);
3673 /* On NOMMU, we must never block!
3674 * Example: { sleep 99 | read line; } & echo Ok
3676 re_execute_shell(to_free,
3685 static void execvp_or_die(char **argv) NORETURN;
3686 static void execvp_or_die(char **argv)
3688 debug_printf_exec("execing '%s'\n", argv[0]);
3689 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3690 execvp(argv[0], argv);
3691 bb_perror_msg("can't execute '%s'", argv[0]);
3692 _exit(127); /* bash compat */
3696 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3697 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3698 #define pseudo_exec(nommu_save, command, argv_expanded) \
3699 pseudo_exec(command, argv_expanded)
3702 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3704 * Don't exit() here. If you don't exec, use _exit instead.
3705 * The at_exit handlers apparently confuse the calling process,
3706 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3707 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3708 char **argv, int assignment_cnt,
3709 char **argv_expanded) NORETURN;
3710 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3711 char **argv, int assignment_cnt,
3712 char **argv_expanded)
3716 /* Case when we are here: ... | var=val | ... */
3717 if (!argv[assignment_cnt])
3718 _exit(EXIT_SUCCESS);
3720 new_env = expand_assignments(argv, assignment_cnt);
3722 set_vars_and_save_old(new_env);
3723 free(new_env); /* optional */
3724 /* we can also destroy set_vars_and_save_old's return value,
3727 nommu_save->new_env = new_env;
3728 nommu_save->old_vars = set_vars_and_save_old(new_env);
3730 if (argv_expanded) {
3731 argv = argv_expanded;
3733 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3735 nommu_save->argv = argv;
3739 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3740 if (strchr(argv[0], '/') != NULL)
3744 /* Check if the command matches any of the builtins.
3745 * Depending on context, this might be redundant. But it's
3746 * easier to waste a few CPU cycles than it is to figure out
3747 * if this is one of those cases.
3750 /* On NOMMU, it is more expensive to re-execute shell
3751 * just in order to run echo or test builtin.
3752 * It's better to skip it here and run corresponding
3753 * non-builtin later. */
3754 const struct built_in_command *x;
3755 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3757 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3760 #if ENABLE_HUSH_FUNCTIONS
3761 /* Check if the command matches any functions */
3763 const struct function *funcp = find_function(argv[0]);
3765 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3770 #if ENABLE_FEATURE_SH_STANDALONE
3771 /* Check if the command matches any busybox applets */
3773 int a = find_applet_by_name(argv[0]);
3775 # if BB_MMU /* see above why on NOMMU it is not allowed */
3776 if (APPLET_IS_NOEXEC(a)) {
3777 debug_printf_exec("running applet '%s'\n", argv[0]);
3778 run_applet_no_and_exit(a, argv);
3781 /* Re-exec ourselves */
3782 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3783 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3784 execv(bb_busybox_exec_path, argv);
3785 /* If they called chroot or otherwise made the binary no longer
3786 * executable, fall through */
3791 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3794 execvp_or_die(argv);
3797 /* Called after [v]fork() in run_pipe
3799 static void pseudo_exec(nommu_save_t *nommu_save,
3800 struct command *command,
3801 char **argv_expanded) NORETURN;
3802 static void pseudo_exec(nommu_save_t *nommu_save,
3803 struct command *command,
3804 char **argv_expanded)
3806 if (command->argv) {
3807 pseudo_exec_argv(nommu_save, command->argv,
3808 command->assignment_cnt, argv_expanded);
3811 if (command->group) {
3812 /* Cases when we are here:
3815 * ... | ( list ) | ...
3816 * ... | { list } | ...
3820 debug_printf_exec("pseudo_exec: run_list\n");
3821 reset_traps_to_defaults();
3822 rcode = run_list(command->group);
3823 /* OK to leak memory by not calling free_pipe_list,
3824 * since this process is about to exit */
3827 re_execute_shell(&nommu_save->argv_from_re_execing,
3828 command->group_as_string,
3835 /* Case when we are here: ... | >file */
3836 debug_printf_exec("pseudo_exec'ed null command\n");
3837 _exit(EXIT_SUCCESS);
3841 static const char *get_cmdtext(struct pipe *pi)
3847 /* This is subtle. ->cmdtext is created only on first backgrounding.
3848 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3849 * On subsequent bg argv is trashed, but we won't use it */
3852 argv = pi->cmds[0].argv;
3853 if (!argv || !argv[0]) {
3854 pi->cmdtext = xzalloc(1);
3860 len += strlen(*argv) + 1;
3864 argv = pi->cmds[0].argv;
3866 len = strlen(*argv);
3867 memcpy(p, *argv, len);
3875 static void insert_bg_job(struct pipe *pi)
3877 struct pipe *job, **jobp;
3880 /* Linear search for the ID of the job to use */
3882 for (job = G.job_list; job; job = job->next)
3883 if (job->jobid >= pi->jobid)
3884 pi->jobid = job->jobid + 1;
3886 /* Add job to the list of running jobs */
3888 while ((job = *jobp) != NULL)
3890 job = *jobp = xmalloc(sizeof(*job));
3892 *job = *pi; /* physical copy */
3894 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3895 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3896 for (i = 0; i < pi->num_cmds; i++) {
3897 job->cmds[i].pid = pi->cmds[i].pid;
3898 /* all other fields are not used and stay zero */
3900 job->cmdtext = xstrdup(get_cmdtext(pi));
3902 if (G_interactive_fd)
3903 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3904 /* Last command's pid goes to $! */
3905 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3906 G.last_jobid = job->jobid;
3909 static void remove_bg_job(struct pipe *pi)
3911 struct pipe *prev_pipe;
3913 if (pi == G.job_list) {
3914 G.job_list = pi->next;
3916 prev_pipe = G.job_list;
3917 while (prev_pipe->next != pi)
3918 prev_pipe = prev_pipe->next;
3919 prev_pipe->next = pi->next;
3922 G.last_jobid = G.job_list->jobid;
3927 /* Remove a backgrounded job */
3928 static void delete_finished_bg_job(struct pipe *pi)
3931 pi->stopped_cmds = 0;
3937 /* Check to see if any processes have exited -- if they
3938 * have, figure out why and see if a job has completed */
3939 static int checkjobs(struct pipe* fg_pipe)
3949 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3951 attributes = WUNTRACED;
3952 if (fg_pipe == NULL)
3953 attributes |= WNOHANG;
3956 #if ENABLE_HUSH_FAST
3957 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3958 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3959 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3960 /* There was neither fork nor SIGCHLD since last waitpid */
3961 /* Avoid doing waitpid syscall if possible */
3962 if (!G.we_have_children) {
3966 if (fg_pipe == NULL) { /* is WNOHANG set? */
3967 /* We have children, but they did not exit
3968 * or stop yet (we saw no SIGCHLD) */
3971 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3975 /* Do we do this right?
3976 * bash-3.00# sleep 20 | false
3978 * [3]+ Stopped sleep 20 | false
3979 * bash-3.00# echo $?
3980 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3981 * [hush 1.14.0: yes we do it right]
3988 #if ENABLE_HUSH_FAST
3989 i = G.count_SIGCHLD;
3991 childpid = waitpid(-1, &status, attributes);
3992 if (childpid <= 0) {
3993 if (childpid && errno != ECHILD)
3994 bb_perror_msg("waitpid");
3995 #if ENABLE_HUSH_FAST
3996 else { /* Until next SIGCHLD, waitpid's are useless */
3997 G.we_have_children = (childpid == 0);
3998 G.handled_SIGCHLD = i;
3999 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4004 dead = WIFEXITED(status) || WIFSIGNALED(status);
4007 if (WIFSTOPPED(status))
4008 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
4009 childpid, WSTOPSIG(status), WEXITSTATUS(status));
4010 if (WIFSIGNALED(status))
4011 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
4012 childpid, WTERMSIG(status), WEXITSTATUS(status));
4013 if (WIFEXITED(status))
4014 debug_printf_jobs("pid %d exited, exitcode %d\n",
4015 childpid, WEXITSTATUS(status));
4017 /* Were we asked to wait for fg pipe? */
4019 for (i = 0; i < fg_pipe->num_cmds; i++) {
4020 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
4021 if (fg_pipe->cmds[i].pid != childpid)
4024 fg_pipe->cmds[i].pid = 0;
4025 fg_pipe->alive_cmds--;
4026 if (i == fg_pipe->num_cmds - 1) {
4027 /* last process gives overall exitstatus */
4028 rcode = WEXITSTATUS(status);
4029 /* bash prints killer signal's name for *last*
4030 * process in pipe (prints just newline for SIGINT).
4031 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
4033 if (WIFSIGNALED(status)) {
4034 int sig = WTERMSIG(status);
4035 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
4036 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
4037 * Maybe we need to use sig | 128? */
4040 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
4043 fg_pipe->cmds[i].is_stopped = 1;
4044 fg_pipe->stopped_cmds++;
4046 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
4047 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
4048 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
4049 /* All processes in fg pipe have exited or stopped */
4050 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4051 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4052 * and "killall -STOP cat" */
4053 if (G_interactive_fd) {
4055 if (fg_pipe->alive_cmds)
4056 insert_bg_job(fg_pipe);
4060 if (!fg_pipe->alive_cmds)
4063 /* There are still running processes in the fg pipe */
4064 goto wait_more; /* do waitpid again */
4066 /* it wasnt fg_pipe, look for process in bg pipes */
4070 /* We asked to wait for bg or orphaned children */
4071 /* No need to remember exitcode in this case */
4072 for (pi = G.job_list; pi; pi = pi->next) {
4073 for (i = 0; i < pi->num_cmds; i++) {
4074 if (pi->cmds[i].pid == childpid)
4075 goto found_pi_and_prognum;
4078 /* Happens when shell is used as init process (init=/bin/sh) */
4079 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4080 continue; /* do waitpid again */
4082 found_pi_and_prognum:
4085 pi->cmds[i].pid = 0;
4087 if (!pi->alive_cmds) {
4088 if (G_interactive_fd)
4089 printf(JOB_STATUS_FORMAT, pi->jobid,
4090 "Done", pi->cmdtext);
4091 delete_finished_bg_job(pi);
4095 pi->cmds[i].is_stopped = 1;
4099 } /* while (waitpid succeeds)... */
4105 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4108 int rcode = checkjobs(fg_pipe);
4109 if (G_saved_tty_pgrp) {
4110 /* Job finished, move the shell to the foreground */
4111 p = getpgrp(); /* our process group id */
4112 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4113 tcsetpgrp(G_interactive_fd, p);
4119 /* Start all the jobs, but don't wait for anything to finish.
4122 * Return code is normally -1, when the caller has to wait for children
4123 * to finish to determine the exit status of the pipe. If the pipe
4124 * is a simple builtin command, however, the action is done by the
4125 * time run_pipe returns, and the exit code is provided as the
4128 * Returns -1 only if started some children. IOW: we have to
4129 * mask out retvals of builtins etc with 0xff!
4131 * The only case when we do not need to [v]fork is when the pipe
4132 * is single, non-backgrounded, non-subshell command. Examples:
4133 * cmd ; ... { list } ; ...
4134 * cmd && ... { list } && ...
4135 * cmd || ... { list } || ...
4136 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4137 * or (if SH_STANDALONE) an applet, and we can run the { list }
4138 * with run_list. If it isn't one of these, we fork and exec cmd.
4140 * Cases when we must fork:
4141 * non-single: cmd | cmd
4142 * backgrounded: cmd & { list } &
4143 * subshell: ( list ) [&]
4145 static NOINLINE int run_pipe(struct pipe *pi)
4147 static const char *const null_ptr = NULL;
4150 struct command *command;
4151 char **argv_expanded;
4154 /* it is not always needed, but we aim to smaller code */
4155 int squirrel[] = { -1, -1, -1 };
4158 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4161 IF_HUSH_JOB(pi->pgrp = -1;)
4162 pi->stopped_cmds = 0;
4163 command = &(pi->cmds[0]);
4164 argv_expanded = NULL;
4166 if (pi->num_cmds != 1
4167 || pi->followup == PIPE_BG
4168 || command->cmd_type == CMD_SUBSHELL
4175 debug_printf_exec(": group:%p argv:'%s'\n",
4176 command->group, command->argv ? command->argv[0] : "NONE");
4178 if (command->group) {
4179 #if ENABLE_HUSH_FUNCTIONS
4180 if (command->cmd_type == CMD_FUNCDEF) {
4181 /* "executing" func () { list } */
4182 struct function *funcp;
4184 funcp = new_function(command->argv[0]);
4185 /* funcp->name is already set to argv[0] */
4186 funcp->body = command->group;
4188 funcp->body_as_string = command->group_as_string;
4189 command->group_as_string = NULL;
4191 command->group = NULL;
4192 command->argv[0] = NULL;
4193 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4194 funcp->parent_cmd = command;
4195 command->child_func = funcp;
4197 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4199 return EXIT_SUCCESS;
4203 debug_printf("non-subshell group\n");
4204 rcode = 1; /* exitcode if redir failed */
4205 if (setup_redirects(command, squirrel) == 0) {
4206 debug_printf_exec(": run_list\n");
4207 rcode = run_list(command->group) & 0xff;
4209 restore_redirects(squirrel);
4210 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4212 debug_printf_exec("run_pipe: return %d\n", rcode);
4216 argv = command->argv ? command->argv : (char **) &null_ptr;
4218 const struct built_in_command *x;
4219 #if ENABLE_HUSH_FUNCTIONS
4220 const struct function *funcp;
4224 char **new_env = NULL;
4225 struct variable *old_vars = NULL;
4227 if (argv[command->assignment_cnt] == NULL) {
4228 /* Assignments, but no command */
4229 /* Ensure redirects take effect (that is, create files).
4230 * Try "a=t >file": */
4231 rcode = setup_redirects(command, squirrel);
4232 restore_redirects(squirrel);
4233 /* Set shell variables */
4235 p = expand_string_to_string(*argv);
4236 debug_printf_exec("set shell var:'%s'->'%s'\n",
4238 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4241 /* Redirect error sets $? to 1. Othervise,
4242 * if evaluating assignment value set $?, retain it.
4243 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4245 rcode = G.last_exitcode;
4246 /* Do we need to flag set_local_var() errors?
4247 * "assignment to readonly var" and "putenv error"
4249 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4251 debug_printf_exec("run_pipe: return %d\n", rcode);
4255 /* Expand the rest into (possibly) many strings each */
4257 #if ENABLE_HUSH_BASH_COMPAT
4258 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4259 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4262 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4263 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4264 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4269 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4272 /* if someone gives us an empty string: `cmd with empty output` */
4273 if (!argv_expanded[0]) {
4274 free(argv_expanded);
4276 return G.last_exitcode;
4279 x = find_builtin(argv_expanded[0]);
4280 #if ENABLE_HUSH_FUNCTIONS
4283 funcp = find_function(argv_expanded[0]);
4287 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4288 debug_printf("exec with redirects only\n");
4289 rcode = setup_redirects(command, NULL);
4290 goto clean_up_and_ret1;
4293 /* setup_redirects acts on file descriptors, not FILEs.
4294 * This is perfect for work that comes after exec().
4295 * Is it really safe for inline use? Experimentally,
4296 * things seem to work. */
4297 rcode = setup_redirects(command, squirrel);
4299 new_env = expand_assignments(argv, command->assignment_cnt);
4300 old_vars = set_vars_and_save_old(new_env);
4302 debug_printf_exec(": builtin '%s' '%s'...\n",
4303 x->b_cmd, argv_expanded[1]);
4304 rcode = x->b_function(argv_expanded) & 0xff;
4307 #if ENABLE_HUSH_FUNCTIONS
4309 # if ENABLE_HUSH_LOCAL
4310 struct variable **sv;
4311 sv = G.shadowed_vars_pp;
4312 G.shadowed_vars_pp = &old_vars;
4314 debug_printf_exec(": function '%s' '%s'...\n",
4315 funcp->name, argv_expanded[1]);
4316 rcode = run_function(funcp, argv_expanded) & 0xff;
4317 # if ENABLE_HUSH_LOCAL
4318 G.shadowed_vars_pp = sv;
4323 #if ENABLE_FEATURE_SH_STANDALONE
4326 restore_redirects(squirrel);
4327 unset_vars(new_env);
4330 free(argv_expanded);
4331 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4333 debug_printf_exec("run_pipe return %d\n", rcode);
4337 #if ENABLE_FEATURE_SH_STANDALONE
4338 i = find_applet_by_name(argv_expanded[0]);
4339 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4340 rcode = setup_redirects(command, squirrel);
4342 new_env = expand_assignments(argv, command->assignment_cnt);
4343 old_vars = set_vars_and_save_old(new_env);
4344 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4345 argv_expanded[0], argv_expanded[1]);
4346 rcode = run_nofork_applet(i, argv_expanded);
4348 goto clean_up_and_ret;
4351 /* It is neither builtin nor applet. We must fork. */
4355 /* NB: argv_expanded may already be created, and that
4356 * might include `cmd` runs! Do not rerun it! We *must*
4357 * use argv_expanded if it's non-NULL */
4359 /* Going to fork a child per each pipe member */
4363 for (i = 0; i < pi->num_cmds; i++) {
4364 struct fd_pair pipefds;
4366 volatile nommu_save_t nommu_save;
4367 nommu_save.new_env = NULL;
4368 nommu_save.old_vars = NULL;
4369 nommu_save.argv = NULL;
4370 nommu_save.argv_from_re_execing = NULL;
4372 command = &(pi->cmds[i]);
4373 if (command->argv) {
4374 debug_printf_exec(": pipe member '%s' '%s'...\n",
4375 command->argv[0], command->argv[1]);
4377 debug_printf_exec(": pipe member with no argv\n");
4380 /* pipes are inserted between pairs of commands */
4383 if ((i + 1) < pi->num_cmds)
4384 xpiped_pair(pipefds);
4386 command->pid = BB_MMU ? fork() : vfork();
4387 if (!command->pid) { /* child */
4389 disable_restore_tty_pgrp_on_exit();
4390 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4392 /* Every child adds itself to new process group
4393 * with pgid == pid_of_first_child_in_pipe */
4394 if (G.run_list_level == 1 && G_interactive_fd) {
4397 if (pgrp < 0) /* true for 1st process only */
4399 if (setpgid(0, pgrp) == 0
4400 && pi->followup != PIPE_BG
4401 && G_saved_tty_pgrp /* we have ctty */
4403 /* We do it in *every* child, not just first,
4405 tcsetpgrp(G_interactive_fd, pgrp);
4409 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4410 /* 1st cmd in backgrounded pipe
4411 * should have its stdin /dev/null'ed */
4413 if (open(bb_dev_null, O_RDONLY))
4414 xopen("/", O_RDONLY);
4416 xmove_fd(nextin, 0);
4418 xmove_fd(pipefds.wr, 1);
4421 /* Like bash, explicit redirects override pipes,
4422 * and the pipe fd is available for dup'ing. */
4423 if (setup_redirects(command, NULL))
4426 /* Restore default handlers just prior to exec */
4427 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4429 /* Stores to nommu_save list of env vars putenv'ed
4430 * (NOMMU, on MMU we don't need that) */
4431 /* cast away volatility... */
4432 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4433 /* pseudo_exec() does not return */
4436 /* parent or error */
4437 #if ENABLE_HUSH_FAST
4439 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4441 enable_restore_tty_pgrp_on_exit();
4443 /* Clean up after vforked child */
4444 free(nommu_save.argv);
4445 free(nommu_save.argv_from_re_execing);
4446 unset_vars(nommu_save.new_env);
4447 add_vars(nommu_save.old_vars);
4449 free(argv_expanded);
4450 argv_expanded = NULL;
4451 if (command->pid < 0) { /* [v]fork failed */
4452 /* Clearly indicate, was it fork or vfork */
4453 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4457 /* Second and next children need to know pid of first one */
4459 pi->pgrp = command->pid;
4465 if ((i + 1) < pi->num_cmds)
4467 /* Pass read (output) pipe end to next iteration */
4468 nextin = pipefds.rd;
4471 if (!pi->alive_cmds) {
4473 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4478 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4482 #ifndef debug_print_tree
4483 static void debug_print_tree(struct pipe *pi, int lvl)
4485 static const char *const PIPE[] = {
4491 static const char *RES[] = {
4492 [RES_NONE ] = "NONE" ,
4495 [RES_THEN ] = "THEN" ,
4496 [RES_ELIF ] = "ELIF" ,
4497 [RES_ELSE ] = "ELSE" ,
4500 # if ENABLE_HUSH_LOOPS
4501 [RES_FOR ] = "FOR" ,
4502 [RES_WHILE] = "WHILE",
4503 [RES_UNTIL] = "UNTIL",
4505 [RES_DONE ] = "DONE" ,
4507 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4510 # if ENABLE_HUSH_CASE
4511 [RES_CASE ] = "CASE" ,
4512 [RES_CASE_IN ] = "CASE_IN" ,
4513 [RES_MATCH] = "MATCH",
4514 [RES_CASE_BODY] = "CASE_BODY",
4515 [RES_ESAC ] = "ESAC" ,
4517 [RES_XXXX ] = "XXXX" ,
4518 [RES_SNTX ] = "SNTX" ,
4520 static const char *const CMDTYPE[] = {
4524 # if ENABLE_HUSH_FUNCTIONS
4533 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4534 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4536 while (prn < pi->num_cmds) {
4537 struct command *command = &pi->cmds[prn];
4538 char **argv = command->argv;
4540 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4542 command->assignment_cnt);
4543 if (command->group) {
4544 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4545 CMDTYPE[command->cmd_type],
4548 , " group_as_string:", command->group_as_string
4553 debug_print_tree(command->group, lvl+1);
4557 if (argv) while (*argv) {
4558 fprintf(stderr, " '%s'", *argv);
4561 fprintf(stderr, "\n");
4568 #endif /* debug_print_tree */
4570 /* NB: called by pseudo_exec, and therefore must not modify any
4571 * global data until exec/_exit (we can be a child after vfork!) */
4572 static int run_list(struct pipe *pi)
4574 #if ENABLE_HUSH_CASE
4575 char *case_word = NULL;
4577 #if ENABLE_HUSH_LOOPS
4578 struct pipe *loop_top = NULL;
4579 char **for_lcur = NULL;
4580 char **for_list = NULL;
4582 smallint last_followup;
4584 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4585 smalluint cond_code = 0;
4587 enum { cond_code = 0 };
4590 smallint rword; /* enum reserved_style */
4591 smallint last_rword; /* ditto */
4594 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4597 #if ENABLE_HUSH_LOOPS
4598 /* Check syntax for "for" */
4599 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4600 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4602 /* current word is FOR or IN (BOLD in comments below) */
4603 if (cpipe->next == NULL) {
4604 syntax_error("malformed for");
4606 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4609 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4610 if (cpipe->next->res_word == RES_DO)
4612 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4613 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4614 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4616 syntax_error("malformed for");
4618 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4624 /* Past this point, all code paths should jump to ret: label
4625 * in order to return, no direct "return" statements please.
4626 * This helps to ensure that no memory is leaked. */
4634 last_rword = RES_XXXX;
4636 last_followup = PIPE_SEQ;
4637 rcode = G.last_exitcode;
4639 /* Go through list of pipes, (maybe) executing them. */
4640 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4644 IF_HAS_KEYWORDS(rword = pi->res_word;)
4645 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4646 rword, cond_code, last_rword);
4647 #if ENABLE_HUSH_LOOPS
4648 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4649 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4651 /* start of a loop: remember where loop starts */
4656 /* Still in the same "if...", "then..." or "do..." branch? */
4657 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4658 if ((rcode == 0 && last_followup == PIPE_OR)
4659 || (rcode != 0 && last_followup == PIPE_AND)
4661 /* It is "<true> || CMD" or "<false> && CMD"
4662 * and we should not execute CMD */
4663 debug_printf_exec("skipped cmd because of || or &&\n");
4664 last_followup = pi->followup;
4668 last_followup = pi->followup;
4669 IF_HAS_KEYWORDS(last_rword = rword;)
4672 if (rword == RES_THEN) {
4673 /* if false; then ... fi has exitcode 0! */
4674 G.last_exitcode = rcode = EXIT_SUCCESS;
4675 /* "if <false> THEN cmd": skip cmd */
4679 if (rword == RES_ELSE || rword == RES_ELIF) {
4680 /* "if <true> then ... ELSE/ELIF cmd":
4681 * skip cmd and all following ones */
4686 #if ENABLE_HUSH_LOOPS
4687 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4689 /* first loop through for */
4691 static const char encoded_dollar_at[] ALIGN1 = {
4692 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4693 }; /* encoded representation of "$@" */
4694 static const char *const encoded_dollar_at_argv[] = {
4695 encoded_dollar_at, NULL
4696 }; /* argv list with one element: "$@" */
4699 vals = (char**)encoded_dollar_at_argv;
4700 if (pi->next->res_word == RES_IN) {
4701 /* if no variable values after "in" we skip "for" */
4702 if (!pi->next->cmds[0].argv) {
4703 G.last_exitcode = rcode = EXIT_SUCCESS;
4704 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4707 vals = pi->next->cmds[0].argv;
4708 } /* else: "for var; do..." -> assume "$@" list */
4709 /* create list of variable values */
4710 debug_print_strings("for_list made from", vals);
4711 for_list = expand_strvec_to_strvec(vals);
4712 for_lcur = for_list;
4713 debug_print_strings("for_list", for_list);
4716 /* "for" loop is over, clean up */
4722 /* Insert next value from for_lcur */
4723 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4724 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4727 if (rword == RES_IN) {
4728 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4730 if (rword == RES_DONE) {
4731 continue; /* "done" has no cmds too */
4734 #if ENABLE_HUSH_CASE
4735 if (rword == RES_CASE) {
4736 case_word = expand_strvec_to_string(pi->cmds->argv);
4739 if (rword == RES_MATCH) {
4742 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4744 /* all prev words didn't match, does this one match? */
4745 argv = pi->cmds->argv;
4747 char *pattern = expand_string_to_string(*argv);
4748 /* TODO: which FNM_xxx flags to use? */
4749 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4751 if (cond_code == 0) { /* match! we will execute this branch */
4752 free(case_word); /* make future "word)" stop */
4760 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4762 continue; /* not matched yet, skip this pipe */
4765 /* Just pressing <enter> in shell should check for jobs.
4766 * OTOH, in non-interactive shell this is useless
4767 * and only leads to extra job checks */
4768 if (pi->num_cmds == 0) {
4769 if (G_interactive_fd)
4770 goto check_jobs_and_continue;
4774 /* After analyzing all keywords and conditions, we decided
4775 * to execute this pipe. NB: have to do checkjobs(NULL)
4776 * after run_pipe to collect any background children,
4777 * even if list execution is to be stopped. */
4778 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4781 #if ENABLE_HUSH_LOOPS
4782 G.flag_break_continue = 0;
4784 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4786 /* We ran a builtin, function, or group.
4787 * rcode is already known
4788 * and we don't need to wait for anything. */
4789 G.last_exitcode = rcode;
4790 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4791 check_and_run_traps(0);
4792 #if ENABLE_HUSH_LOOPS
4793 /* Was it "break" or "continue"? */
4794 if (G.flag_break_continue) {
4795 smallint fbc = G.flag_break_continue;
4796 /* We might fall into outer *loop*,
4797 * don't want to break it too */
4799 G.depth_break_continue--;
4800 if (G.depth_break_continue == 0)
4801 G.flag_break_continue = 0;
4802 /* else: e.g. "continue 2" should *break* once, *then* continue */
4803 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4804 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4805 goto check_jobs_and_break;
4806 /* "continue": simulate end of loop */
4811 #if ENABLE_HUSH_FUNCTIONS
4812 if (G.flag_return_in_progress == 1) {
4813 /* same as "goto check_jobs_and_break" */
4818 } else if (pi->followup == PIPE_BG) {
4819 /* What does bash do with attempts to background builtins? */
4820 /* even bash 3.2 doesn't do that well with nested bg:
4821 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4822 * I'm NOT treating inner &'s as jobs */
4823 check_and_run_traps(0);
4825 if (G.run_list_level == 1)
4828 G.last_exitcode = rcode = EXIT_SUCCESS;
4829 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4832 if (G.run_list_level == 1 && G_interactive_fd) {
4833 /* Waits for completion, then fg's main shell */
4834 rcode = checkjobs_and_fg_shell(pi);
4835 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4836 check_and_run_traps(0);
4839 { /* This one just waits for completion */
4840 rcode = checkjobs(pi);
4841 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4842 check_and_run_traps(0);
4844 G.last_exitcode = rcode;
4848 /* Analyze how result affects subsequent commands */
4850 if (rword == RES_IF || rword == RES_ELIF)
4853 #if ENABLE_HUSH_LOOPS
4854 /* Beware of "while false; true; do ..."! */
4855 if (pi->next && pi->next->res_word == RES_DO) {
4856 if (rword == RES_WHILE) {
4858 /* "while false; do...done" - exitcode 0 */
4859 G.last_exitcode = rcode = EXIT_SUCCESS;
4860 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4861 goto check_jobs_and_break;
4864 if (rword == RES_UNTIL) {
4866 debug_printf_exec(": until expr is true: breaking\n");
4867 check_jobs_and_break:
4875 check_jobs_and_continue:
4882 #if ENABLE_HUSH_LOOPS
4887 #if ENABLE_HUSH_CASE
4891 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4895 /* Select which version we will use */
4896 static int run_and_free_list(struct pipe *pi)
4899 debug_printf_exec("run_and_free_list entered\n");
4901 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4902 rcode = run_list(pi);
4904 /* free_pipe_list has the side effect of clearing memory.
4905 * In the long run that function can be merged with run_list,
4906 * but doing that now would hobble the debugging effort. */
4908 debug_printf_exec("run_and_free_list return %d\n", rcode);
4913 static struct pipe *new_pipe(void)
4916 pi = xzalloc(sizeof(struct pipe));
4917 /*pi->followup = 0; - deliberately invalid value */
4918 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4922 /* Command (member of a pipe) is complete, or we start a new pipe
4923 * if ctx->command is NULL.
4924 * No errors possible here.
4926 static int done_command(struct parse_context *ctx)
4928 /* The command is really already in the pipe structure, so
4929 * advance the pipe counter and make a new, null command. */
4930 struct pipe *pi = ctx->pipe;
4931 struct command *command = ctx->command;
4934 if (IS_NULL_CMD(command)) {
4935 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4939 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4940 //debug_print_tree(ctx->list_head, 20);
4942 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4945 /* Only real trickiness here is that the uncommitted
4946 * command structure is not counted in pi->num_cmds. */
4947 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4948 ctx->command = command = &pi->cmds[pi->num_cmds];
4950 memset(command, 0, sizeof(*command));
4951 return pi->num_cmds; /* used only for 0/nonzero check */
4954 static void done_pipe(struct parse_context *ctx, pipe_style type)
4958 debug_printf_parse("done_pipe entered, followup %d\n", type);
4959 /* Close previous command */
4960 not_null = done_command(ctx);
4961 ctx->pipe->followup = type;
4963 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4964 ctx->ctx_inverted = 0;
4965 ctx->pipe->res_word = ctx->ctx_res_w;
4968 /* Without this check, even just <enter> on command line generates
4969 * tree of three NOPs (!). Which is harmless but annoying.
4970 * IOW: it is safe to do it unconditionally. */
4973 || ctx->ctx_res_w == RES_FI
4975 #if ENABLE_HUSH_LOOPS
4976 || ctx->ctx_res_w == RES_DONE
4977 || ctx->ctx_res_w == RES_FOR
4978 || ctx->ctx_res_w == RES_IN
4980 #if ENABLE_HUSH_CASE
4981 || ctx->ctx_res_w == RES_ESAC
4985 debug_printf_parse("done_pipe: adding new pipe: "
4986 "not_null:%d ctx->ctx_res_w:%d\n",
4987 not_null, ctx->ctx_res_w);
4989 ctx->pipe->next = new_p;
4991 /* RES_THEN, RES_DO etc are "sticky" -
4992 * they remain set for pipes inside if/while.
4993 * This is used to control execution.
4994 * RES_FOR and RES_IN are NOT sticky (needed to support
4995 * cases where variable or value happens to match a keyword):
4997 #if ENABLE_HUSH_LOOPS
4998 if (ctx->ctx_res_w == RES_FOR
4999 || ctx->ctx_res_w == RES_IN)
5000 ctx->ctx_res_w = RES_NONE;
5002 #if ENABLE_HUSH_CASE
5003 if (ctx->ctx_res_w == RES_MATCH)
5004 ctx->ctx_res_w = RES_CASE_BODY;
5005 if (ctx->ctx_res_w == RES_CASE)
5006 ctx->ctx_res_w = RES_CASE_IN;
5008 ctx->command = NULL; /* trick done_command below */
5009 /* Create the memory for command, roughly:
5010 * ctx->pipe->cmds = new struct command;
5011 * ctx->command = &ctx->pipe->cmds[0];
5014 //debug_print_tree(ctx->list_head, 10);
5016 debug_printf_parse("done_pipe return\n");
5019 static void initialize_context(struct parse_context *ctx)
5021 memset(ctx, 0, sizeof(*ctx));
5022 ctx->pipe = ctx->list_head = new_pipe();
5023 /* Create the memory for command, roughly:
5024 * ctx->pipe->cmds = new struct command;
5025 * ctx->command = &ctx->pipe->cmds[0];
5030 /* If a reserved word is found and processed, parse context is modified
5031 * and 1 is returned.
5034 struct reserved_combo {
5037 unsigned char assignment_flag;
5041 FLAG_END = (1 << RES_NONE ),
5043 FLAG_IF = (1 << RES_IF ),
5044 FLAG_THEN = (1 << RES_THEN ),
5045 FLAG_ELIF = (1 << RES_ELIF ),
5046 FLAG_ELSE = (1 << RES_ELSE ),
5047 FLAG_FI = (1 << RES_FI ),
5049 # if ENABLE_HUSH_LOOPS
5050 FLAG_FOR = (1 << RES_FOR ),
5051 FLAG_WHILE = (1 << RES_WHILE),
5052 FLAG_UNTIL = (1 << RES_UNTIL),
5053 FLAG_DO = (1 << RES_DO ),
5054 FLAG_DONE = (1 << RES_DONE ),
5055 FLAG_IN = (1 << RES_IN ),
5057 # if ENABLE_HUSH_CASE
5058 FLAG_MATCH = (1 << RES_MATCH),
5059 FLAG_ESAC = (1 << RES_ESAC ),
5061 FLAG_START = (1 << RES_XXXX ),
5064 static const struct reserved_combo* match_reserved_word(o_string *word)
5066 /* Mostly a list of accepted follow-up reserved words.
5067 * FLAG_END means we are done with the sequence, and are ready
5068 * to turn the compound list into a command.
5069 * FLAG_START means the word must start a new compound list.
5071 static const struct reserved_combo reserved_list[] = {
5073 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5074 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5075 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5076 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5077 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5078 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5080 # if ENABLE_HUSH_LOOPS
5081 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5082 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5083 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5084 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5085 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5086 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5088 # if ENABLE_HUSH_CASE
5089 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5090 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5093 const struct reserved_combo *r;
5095 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5096 if (strcmp(word->data, r->literal) == 0)
5101 /* Return 0: not a keyword, 1: keyword
5103 static int reserved_word(o_string *word, struct parse_context *ctx)
5105 # if ENABLE_HUSH_CASE
5106 static const struct reserved_combo reserved_match = {
5107 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5110 const struct reserved_combo *r;
5114 r = match_reserved_word(word);
5118 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5119 # if ENABLE_HUSH_CASE
5120 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5121 /* "case word IN ..." - IN part starts first MATCH part */
5122 r = &reserved_match;
5125 if (r->flag == 0) { /* '!' */
5126 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5127 syntax_error("! ! command");
5128 ctx->ctx_res_w = RES_SNTX;
5130 ctx->ctx_inverted = 1;
5133 if (r->flag & FLAG_START) {
5134 struct parse_context *old;
5136 old = xmalloc(sizeof(*old));
5137 debug_printf_parse("push stack %p\n", old);
5138 *old = *ctx; /* physical copy */
5139 initialize_context(ctx);
5141 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5142 syntax_error_at(word->data);
5143 ctx->ctx_res_w = RES_SNTX;
5146 /* "{...} fi" is ok. "{...} if" is not
5148 * if { echo foo; } then { echo bar; } fi */
5149 if (ctx->command->group)
5150 done_pipe(ctx, PIPE_SEQ);
5153 ctx->ctx_res_w = r->res;
5154 ctx->old_flag = r->flag;
5155 word->o_assignment = r->assignment_flag;
5157 if (ctx->old_flag & FLAG_END) {
5158 struct parse_context *old;
5160 done_pipe(ctx, PIPE_SEQ);
5161 debug_printf_parse("pop stack %p\n", ctx->stack);
5163 old->command->group = ctx->list_head;
5164 old->command->cmd_type = CMD_NORMAL;
5166 o_addstr(&old->as_string, ctx->as_string.data);
5167 o_free_unsafe(&ctx->as_string);
5168 old->command->group_as_string = xstrdup(old->as_string.data);
5169 debug_printf_parse("pop, remembering as:'%s'\n",
5170 old->command->group_as_string);
5172 *ctx = *old; /* physical copy */
5177 #endif /* HAS_KEYWORDS */
5179 /* Word is complete, look at it and update parsing context.
5180 * Normal return is 0. Syntax errors return 1.
5181 * Note: on return, word is reset, but not o_free'd!
5183 static int done_word(o_string *word, struct parse_context *ctx)
5185 struct command *command = ctx->command;
5187 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5188 if (word->length == 0 && word->o_quoted == 0) {
5189 debug_printf_parse("done_word return 0: true null, ignored\n");
5193 if (ctx->pending_redirect) {
5194 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5195 * only if run as "bash", not "sh" */
5196 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5198 * ...the word that follows the redirection operator
5199 * shall be subjected to tilde expansion, parameter expansion,
5200 * command substitution, arithmetic expansion, and quote
5201 * removal. Pathname expansion shall not be performed
5202 * on the word by a non-interactive shell; an interactive
5203 * shell may perform it, but shall do so only when
5204 * the expansion would result in one word."
5206 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5207 /* Cater for >\file case:
5208 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5209 * Same with heredocs:
5210 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5212 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5213 unbackslash(ctx->pending_redirect->rd_filename);
5214 /* Is it <<"HEREDOC"? */
5215 if (word->o_quoted) {
5216 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5219 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5220 ctx->pending_redirect = NULL;
5222 /* If this word wasn't an assignment, next ones definitely
5223 * can't be assignments. Even if they look like ones. */
5224 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5225 && word->o_assignment != WORD_IS_KEYWORD
5227 word->o_assignment = NOT_ASSIGNMENT;
5229 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5230 command->assignment_cnt++;
5231 word->o_assignment = MAYBE_ASSIGNMENT;
5235 # if ENABLE_HUSH_CASE
5236 if (ctx->ctx_dsemicolon
5237 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5239 /* already done when ctx_dsemicolon was set to 1: */
5240 /* ctx->ctx_res_w = RES_MATCH; */
5241 ctx->ctx_dsemicolon = 0;
5244 if (!command->argv /* if it's the first word... */
5245 # if ENABLE_HUSH_LOOPS
5246 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5247 && ctx->ctx_res_w != RES_IN
5249 # if ENABLE_HUSH_CASE
5250 && ctx->ctx_res_w != RES_CASE
5253 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5254 if (reserved_word(word, ctx)) {
5255 o_reset_to_empty_unquoted(word);
5256 debug_printf_parse("done_word return %d\n",
5257 (ctx->ctx_res_w == RES_SNTX));
5258 return (ctx->ctx_res_w == RES_SNTX);
5260 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5261 if (strcmp(word->data, "export") == 0
5262 # if ENABLE_HUSH_LOCAL
5263 || strcmp(word->data, "local") == 0
5266 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5269 # if ENABLE_HUSH_BASH_COMPAT
5270 if (strcmp(word->data, "[[") == 0) {
5271 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5277 if (command->group) {
5278 /* "{ echo foo; } echo bar" - bad */
5279 syntax_error_at(word->data);
5280 debug_printf_parse("done_word return 1: syntax error, "
5281 "groups and arglists don't mix\n");
5284 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5285 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5286 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5287 /* (otherwise it's known to be not empty and is already safe) */
5289 /* exclude "$@" - it can expand to no word despite "" */
5290 char *p = word->data;
5291 while (p[0] == SPECIAL_VAR_SYMBOL
5292 && (p[1] & 0x7f) == '@'
5293 && p[2] == SPECIAL_VAR_SYMBOL
5297 if (p == word->data || p[0] != '\0') {
5298 /* saw no "$@", or not only "$@" but some
5299 * real text is there too */
5300 /* insert "empty variable" reference, this makes
5301 * e.g. "", $empty"" etc to not disappear */
5302 o_addchr(word, SPECIAL_VAR_SYMBOL);
5303 o_addchr(word, SPECIAL_VAR_SYMBOL);
5306 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5307 debug_print_strings("word appended to argv", command->argv);
5310 #if ENABLE_HUSH_LOOPS
5311 if (ctx->ctx_res_w == RES_FOR) {
5313 || !is_well_formed_var_name(command->argv[0], '\0')
5315 /* bash says just "not a valid identifier" */
5316 syntax_error("not a valid identifier in for");
5319 /* Force FOR to have just one word (variable name) */
5320 /* NB: basically, this makes hush see "for v in ..."
5321 * syntax as if it is "for v; in ...". FOR and IN become
5322 * two pipe structs in parse tree. */
5323 done_pipe(ctx, PIPE_SEQ);
5326 #if ENABLE_HUSH_CASE
5327 /* Force CASE to have just one word */
5328 if (ctx->ctx_res_w == RES_CASE) {
5329 done_pipe(ctx, PIPE_SEQ);
5333 o_reset_to_empty_unquoted(word);
5335 debug_printf_parse("done_word return 0\n");
5340 /* Peek ahead in the input to find out if we have a "&n" construct,
5341 * as in "2>&1", that represents duplicating a file descriptor.
5343 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5344 * REDIRFD_SYNTAX_ERR if syntax error,
5345 * REDIRFD_TO_FILE if no & was seen,
5346 * or the number found.
5349 #define parse_redir_right_fd(as_string, input) \
5350 parse_redir_right_fd(input)
5352 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5358 return REDIRFD_TO_FILE;
5360 ch = i_getch(input); /* get the & */
5361 nommu_addchr(as_string, ch);
5364 ch = i_getch(input);
5365 nommu_addchr(as_string, ch);
5366 return REDIRFD_CLOSE;
5370 while (ch != EOF && isdigit(ch)) {
5371 d = d*10 + (ch-'0');
5373 ch = i_getch(input);
5374 nommu_addchr(as_string, ch);
5379 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5381 bb_error_msg("ambiguous redirect");
5382 return REDIRFD_SYNTAX_ERR;
5385 /* Return code is 0 normal, 1 if a syntax error is detected
5387 static int parse_redirect(struct parse_context *ctx,
5390 struct in_str *input)
5392 struct command *command = ctx->command;
5393 struct redir_struct *redir;
5394 struct redir_struct **redirp;
5397 dup_num = REDIRFD_TO_FILE;
5398 if (style != REDIRECT_HEREDOC) {
5399 /* Check for a '>&1' type redirect */
5400 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5401 if (dup_num == REDIRFD_SYNTAX_ERR)
5404 int ch = i_peek(input);
5405 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5406 if (dup_num) { /* <<-... */
5407 ch = i_getch(input);
5408 nommu_addchr(&ctx->as_string, ch);
5413 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5414 int ch = i_peek(input);
5416 /* >|FILE redirect ("clobbering" >).
5417 * Since we do not support "set -o noclobber" yet,
5418 * >| and > are the same for now. Just eat |.
5420 ch = i_getch(input);
5421 nommu_addchr(&ctx->as_string, ch);
5425 /* Create a new redir_struct and append it to the linked list */
5426 redirp = &command->redirects;
5427 while ((redir = *redirp) != NULL) {
5428 redirp = &(redir->next);
5430 *redirp = redir = xzalloc(sizeof(*redir));
5431 /* redir->next = NULL; */
5432 /* redir->rd_filename = NULL; */
5433 redir->rd_type = style;
5434 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5436 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5437 redir_table[style].descrip);
5439 redir->rd_dup = dup_num;
5440 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5441 /* Erik had a check here that the file descriptor in question
5442 * is legit; I postpone that to "run time"
5443 * A "-" representation of "close me" shows up as a -3 here */
5444 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5445 redir->rd_fd, redir->rd_dup);
5447 /* Set ctx->pending_redirect, so we know what to do at the
5448 * end of the next parsed word. */
5449 ctx->pending_redirect = redir;
5454 /* If a redirect is immediately preceded by a number, that number is
5455 * supposed to tell which file descriptor to redirect. This routine
5456 * looks for such preceding numbers. In an ideal world this routine
5457 * needs to handle all the following classes of redirects...
5458 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5459 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5460 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5461 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5463 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5465 * ... If n is quoted, the number shall not be recognized as part of
5466 * the redirection expression. For example:
5468 * writes the character 2 into file a"
5469 * We are getting it right by setting ->o_quoted on any \<char>
5471 * A -1 return means no valid number was found,
5472 * the caller should use the appropriate default for this redirection.
5474 static int redirect_opt_num(o_string *o)
5478 if (o->data == NULL)
5480 num = bb_strtou(o->data, NULL, 10);
5481 if (errno || num < 0)
5483 o_reset_to_empty_unquoted(o);
5488 #define fetch_till_str(as_string, input, word, skip_tabs) \
5489 fetch_till_str(input, word, skip_tabs)
5491 static char *fetch_till_str(o_string *as_string,
5492 struct in_str *input,
5496 o_string heredoc = NULL_O_STRING;
5502 ch = i_getch(input);
5503 nommu_addchr(as_string, ch);
5505 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5506 heredoc.data[past_EOL] = '\0';
5507 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5508 return heredoc.data;
5511 o_addchr(&heredoc, ch);
5512 past_EOL = heredoc.length;
5515 ch = i_getch(input);
5516 nommu_addchr(as_string, ch);
5517 } while (skip_tabs && ch == '\t');
5518 } while (ch == '\n');
5521 o_free_unsafe(&heredoc);
5524 o_addchr(&heredoc, ch);
5525 nommu_addchr(as_string, ch);
5529 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5530 * and load them all. There should be exactly heredoc_cnt of them.
5532 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5534 struct pipe *pi = ctx->list_head;
5536 while (pi && heredoc_cnt) {
5538 struct command *cmd = pi->cmds;
5540 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5542 cmd->argv ? cmd->argv[0] : "NONE");
5543 for (i = 0; i < pi->num_cmds; i++) {
5544 struct redir_struct *redir = cmd->redirects;
5546 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5547 i, cmd->argv ? cmd->argv[0] : "NONE");
5549 if (redir->rd_type == REDIRECT_HEREDOC) {
5552 redir->rd_type = REDIRECT_HEREDOC2;
5553 /* redir->rd_dup is (ab)used to indicate <<- */
5554 p = fetch_till_str(&ctx->as_string, input,
5555 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5557 syntax_error("unexpected EOF in here document");
5560 free(redir->rd_filename);
5561 redir->rd_filename = p;
5564 redir = redir->next;
5571 /* Should be 0. If it isn't, it's a parse error */
5573 bb_error_msg_and_die("heredoc BUG 2");
5579 #if ENABLE_HUSH_TICK
5580 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5585 char **to_free = NULL;
5589 pid = BB_MMU ? fork() : vfork();
5591 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5593 if (pid == 0) { /* child */
5594 disable_restore_tty_pgrp_on_exit();
5595 /* Process substitution is not considered to be usual
5596 * 'command execution'.
5597 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5604 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5605 close(channel[0]); /* NB: close _first_, then move fd! */
5606 xmove_fd(channel[1], 1);
5607 /* Prevent it from trying to handle ctrl-z etc */
5608 IF_HUSH_JOB(G.run_list_level = 1;)
5609 /* Awful hack for `trap` or $(trap).
5611 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5612 * contains an example where "trap" is executed in a subshell:
5614 * save_traps=$(trap)
5616 * eval "$save_traps"
5618 * Standard does not say that "trap" in subshell shall print
5619 * parent shell's traps. It only says that its output
5620 * must have suitable form, but then, in the above example
5621 * (which is not supposed to be normative), it implies that.
5623 * bash (and probably other shell) does implement it
5624 * (traps are reset to defaults, but "trap" still shows them),
5625 * but as a result, "trap" logic is hopelessly messed up:
5628 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5629 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5630 * # true | trap <--- trap is in subshell - no output (ditto)
5631 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5632 * trap -- 'echo Ho' SIGWINCH
5633 * # echo `(trap)` <--- in subshell in subshell - output
5634 * trap -- 'echo Ho' SIGWINCH
5635 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5636 * trap -- 'echo Ho' SIGWINCH
5638 * The rules when to forget and when to not forget traps
5639 * get really complex and nonsensical.
5641 * Our solution: ONLY bare $(trap) or `trap` is special.
5643 s = skip_whitespace(s);
5644 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5646 static const char *const argv[] = { NULL, NULL };
5647 builtin_trap((char**)argv);
5648 exit(0); /* not _exit() - we need to fflush */
5651 reset_traps_to_defaults();
5652 parse_and_run_string(s);
5653 _exit(G.last_exitcode);
5655 /* We re-execute after vfork on NOMMU. This makes this script safe:
5656 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5657 * huge=`cat BIG` # was blocking here forever
5660 re_execute_shell(&to_free,
5670 # if ENABLE_HUSH_FAST
5672 //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);
5674 enable_restore_tty_pgrp_on_exit();
5679 close_on_exec_on(channel[0]);
5680 return xfdopen_for_read(channel[0]);
5683 /* Return code is exit status of the process that is run. */
5684 static int process_command_subs(o_string *dest, const char *s)
5687 struct in_str pipe_str;
5689 int status, ch, eol_cnt;
5691 fp = generate_stream_from_string(s, &pid);
5693 /* Now send results of command back into original context */
5694 setup_file_in_str(&pipe_str, fp);
5696 while ((ch = i_getch(&pipe_str)) != EOF) {
5702 o_addchr(dest, '\n');
5705 o_addQchr(dest, ch);
5708 debug_printf("done reading from `cmd` pipe, closing it\n");
5710 /* We need to extract exitcode. Test case
5711 * "true; echo `sleep 1; false` $?"
5713 safe_waitpid(pid, &status, 0);
5714 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5715 return WEXITSTATUS(status);
5717 #endif /* ENABLE_HUSH_TICK */
5719 #if !ENABLE_HUSH_FUNCTIONS
5720 #define parse_group(dest, ctx, input, ch) \
5721 parse_group(ctx, input, ch)
5723 static int parse_group(o_string *dest, struct parse_context *ctx,
5724 struct in_str *input, int ch)
5726 /* dest contains characters seen prior to ( or {.
5727 * Typically it's empty, but for function defs,
5728 * it contains function name (without '()'). */
5729 struct pipe *pipe_list;
5731 struct command *command = ctx->command;
5733 debug_printf_parse("parse_group entered\n");
5734 #if ENABLE_HUSH_FUNCTIONS
5735 if (ch == '(' && !dest->o_quoted) {
5737 if (done_word(dest, ctx))
5740 goto skip; /* (... */
5741 if (command->argv[1]) { /* word word ... (... */
5742 syntax_error_unexpected_ch('(');
5745 /* it is "word(..." or "word (..." */
5747 ch = i_getch(input);
5748 while (ch == ' ' || ch == '\t');
5750 syntax_error_unexpected_ch(ch);
5753 nommu_addchr(&ctx->as_string, ch);
5755 ch = i_getch(input);
5756 while (ch == ' ' || ch == '\t' || ch == '\n');
5758 syntax_error_unexpected_ch(ch);
5761 nommu_addchr(&ctx->as_string, ch);
5762 command->cmd_type = CMD_FUNCDEF;
5767 #if 0 /* Prevented by caller */
5768 if (command->argv /* word [word]{... */
5769 || dest->length /* word{... */
5770 || dest->o_quoted /* ""{... */
5773 debug_printf_parse("parse_group return 1: "
5774 "syntax error, groups and arglists don't mix\n");
5779 #if ENABLE_HUSH_FUNCTIONS
5785 command->cmd_type = CMD_SUBSHELL;
5787 /* bash does not allow "{echo...", requires whitespace */
5788 ch = i_getch(input);
5789 if (ch != ' ' && ch != '\t' && ch != '\n') {
5790 syntax_error_unexpected_ch(ch);
5793 nommu_addchr(&ctx->as_string, ch);
5798 # define as_string NULL
5800 char *as_string = NULL;
5802 pipe_list = parse_stream(&as_string, input, endch);
5805 o_addstr(&ctx->as_string, as_string);
5807 /* empty ()/{} or parse error? */
5808 if (!pipe_list || pipe_list == ERR_PTR) {
5809 /* parse_stream already emitted error msg */
5812 debug_printf_parse("parse_group return 1: "
5813 "parse_stream returned %p\n", pipe_list);
5816 command->group = pipe_list;
5818 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5819 command->group_as_string = as_string;
5820 debug_printf_parse("end of group, remembering as:'%s'\n",
5821 command->group_as_string);
5825 debug_printf_parse("parse_group return 0\n");
5827 /* command remains "open", available for possible redirects */
5830 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5831 /* Subroutines for copying $(...) and `...` things */
5832 static void add_till_backquote(o_string *dest, struct in_str *input);
5834 static void add_till_single_quote(o_string *dest, struct in_str *input)
5837 int ch = i_getch(input);
5839 syntax_error_unterm_ch('\'');
5840 /*xfunc_die(); - redundant */
5847 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5848 static void add_till_double_quote(o_string *dest, struct in_str *input)
5851 int ch = i_getch(input);
5853 syntax_error_unterm_ch('"');
5854 /*xfunc_die(); - redundant */
5858 if (ch == '\\') { /* \x. Copy both chars. */
5860 ch = i_getch(input);
5864 add_till_backquote(dest, input);
5868 //if (ch == '$') ...
5871 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5873 * "Within the backquoted style of command substitution, backslash
5874 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5875 * The search for the matching backquote shall be satisfied by the first
5876 * backquote found without a preceding backslash; during this search,
5877 * if a non-escaped backquote is encountered within a shell comment,
5878 * a here-document, an embedded command substitution of the $(command)
5879 * form, or a quoted string, undefined results occur. A single-quoted
5880 * or double-quoted string that begins, but does not end, within the
5881 * "`...`" sequence produces undefined results."
5883 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5885 static void add_till_backquote(o_string *dest, struct in_str *input)
5888 int ch = i_getch(input);
5890 syntax_error_unterm_ch('`');
5891 /*xfunc_die(); - redundant */
5896 /* \x. Copy both chars unless it is \` */
5897 int ch2 = i_getch(input);
5899 syntax_error_unterm_ch('`');
5900 /*xfunc_die(); - redundant */
5902 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5909 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5910 * quoting and nested ()s.
5911 * "With the $(command) style of command substitution, all characters
5912 * following the open parenthesis to the matching closing parenthesis
5913 * constitute the command. Any valid shell script can be used for command,
5914 * except a script consisting solely of redirections which produces
5915 * unspecified results."
5917 * echo $(echo '(TEST)' BEST) (TEST) BEST
5918 * echo $(echo 'TEST)' BEST) TEST) BEST
5919 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5921 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
5922 * can contain arbitrary constructs, just like $(cmd).
5923 * In bash compat mode, it needs to also be able to stop on '}' or ':'
5924 * for ${var:N[:M]} parsing.
5926 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
5927 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
5930 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
5931 #if ENABLE_HUSH_BASH_COMPAT
5932 char end_char2 = end_ch >> 8;
5934 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
5937 ch = i_getch(input);
5939 syntax_error_unterm_ch(end_ch);
5940 /*xfunc_die(); - redundant */
5942 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
5945 /* we look for closing )) of $((EXPR)) */
5946 if (i_peek(input) == end_ch) {
5947 i_getch(input); /* eat second ')' */
5952 if (ch == '(' || ch == '{') {
5953 ch = (ch == '(' ? ')' : '}');
5954 add_till_closing_bracket(dest, input, ch);
5959 add_till_single_quote(dest, input);
5964 add_till_double_quote(dest, input);
5969 add_till_backquote(dest, input);
5974 /* \x. Copy verbatim. Important for \(, \) */
5975 ch = i_getch(input);
5977 syntax_error_unterm_ch(')');
5978 /*xfunc_die(); - redundant */
5986 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5988 /* Return code: 0 for OK, 1 for syntax error */
5990 #define parse_dollar(as_string, dest, input) \
5991 parse_dollar(dest, input)
5992 #define as_string NULL
5994 static int parse_dollar(o_string *as_string,
5996 struct in_str *input)
5998 int ch = i_peek(input); /* first character after the $ */
5999 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
6001 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
6003 ch = i_getch(input);
6004 nommu_addchr(as_string, ch);
6006 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6008 debug_printf_parse(": '%c'\n", ch);
6009 o_addchr(dest, ch | quote_mask);
6012 if (!isalnum(ch) && ch != '_')
6014 ch = i_getch(input);
6015 nommu_addchr(as_string, ch);
6017 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6018 } else if (isdigit(ch)) {
6020 ch = i_getch(input);
6021 nommu_addchr(as_string, ch);
6022 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6023 debug_printf_parse(": '%c'\n", ch);
6024 o_addchr(dest, ch | quote_mask);
6025 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6026 } else switch (ch) {
6028 case '!': /* last bg pid */
6029 case '?': /* last exit code */
6030 case '#': /* number of args */
6031 case '*': /* args */
6032 case '@': /* args */
6033 goto make_one_char_var;
6035 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6037 ch = i_getch(input); /* eat '{' */
6038 nommu_addchr(as_string, ch);
6040 ch = i_getch(input); /* first char after '{' */
6041 nommu_addchr(as_string, ch);
6042 /* It should be ${?}, or ${#var},
6043 * or even ${?+subst} - operator acting on a special variable,
6044 * or the beginning of variable name.
6046 if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
6048 syntax_error_unterm_str("${name}");
6049 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
6054 /* It's possible to just call add_till_closing_bracket() at this point.
6055 * However, this regresses some of our testsuite cases
6056 * which check invalid constructs like ${%}.
6057 * Oh well... let's check that the var name part is fine... */
6063 debug_printf_parse(": '%c'\n", ch);
6065 ch = i_getch(input);
6066 nommu_addchr(as_string, ch);
6070 if (!isalnum(ch) && ch != '_') {
6072 unsigned char last_ch;
6073 /* handle parameter expansions
6074 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6076 if (!strchr("%#:-=+?", ch)) /* ${var<bad_char>... */
6077 goto bad_dollar_syntax;
6080 /* Eat everything until closing '}' (or ':') */
6082 if (ENABLE_HUSH_BASH_COMPAT
6084 && !strchr("%#:-=+?"+3, i_peek(input))
6086 /* It's ${var:N[:M]} thing */
6087 end_ch = '}' * 0x100 + ':';
6092 last_ch = add_till_closing_bracket(dest, input, end_ch);
6094 o_addstr(as_string, dest->data + pos);
6095 o_addchr(as_string, last_ch);
6098 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
6099 /* close the first block: */
6100 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6101 /* while parsing N from ${var:N[:M]}... */
6102 if ((end_ch & 0xff) == last_ch) {
6103 /* ...got ':' - parse the rest */
6107 /* ...got '}', not ':' - it's ${var:N}! emulate :999999999 */
6108 o_addstr(dest, "999999999");
6113 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6116 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6120 ch = i_getch(input);
6121 nommu_addchr(as_string, ch);
6122 # if ENABLE_SH_MATH_SUPPORT
6123 if (i_peek(input) == '(') {
6124 ch = i_getch(input);
6125 nommu_addchr(as_string, ch);
6126 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6127 o_addchr(dest, /*quote_mask |*/ '+');
6130 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
6132 o_addstr(as_string, dest->data + pos);
6133 o_addchr(as_string, ')');
6134 o_addchr(as_string, ')');
6136 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6140 # if ENABLE_HUSH_TICK
6141 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6142 o_addchr(dest, quote_mask | '`');
6145 add_till_closing_bracket(dest, input, ')');
6147 o_addstr(as_string, dest->data + pos);
6148 o_addchr(as_string, ')');
6150 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6156 ch = i_getch(input);
6157 nommu_addchr(as_string, ch);
6159 if (isalnum(ch)) { /* it's $_name or $_123 */
6164 /* TODO: $_ and $-: */
6165 /* $_ Shell or shell script name; or last argument of last command
6166 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6167 * but in command's env, set to full pathname used to invoke it */
6168 /* $- Option flags set by set builtin or shell options (-i etc) */
6170 o_addQchr(dest, '$');
6172 debug_printf_parse("parse_dollar return 0\n");
6178 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6179 parse_stream_dquoted(dest, input, dquote_end)
6180 #define as_string NULL
6182 static int parse_stream_dquoted(o_string *as_string,
6184 struct in_str *input,
6191 ch = i_getch(input);
6193 nommu_addchr(as_string, ch);
6194 if (ch == dquote_end) { /* may be only '"' or EOF */
6195 if (dest->o_assignment == NOT_ASSIGNMENT)
6196 dest->o_escape ^= 1;
6197 debug_printf_parse("parse_stream_dquoted return 0\n");
6200 /* note: can't move it above ch == dquote_end check! */
6202 syntax_error_unterm_ch('"');
6203 /*xfunc_die(); - redundant */
6207 next = i_peek(input);
6209 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6210 ch, ch, dest->o_escape);
6213 syntax_error("\\<eof>");
6217 * "The backslash retains its special meaning [in "..."]
6218 * only when followed by one of the following characters:
6219 * $, `, ", \, or <newline>. A double quote may be quoted
6220 * within double quotes by preceding it with a backslash."
6222 if (strchr("$`\"\\\n", next) != NULL) {
6223 ch = i_getch(input);
6225 o_addqchr(dest, ch);
6226 nommu_addchr(as_string, ch);
6229 o_addqchr(dest, '\\');
6230 nommu_addchr(as_string, '\\');
6235 if (parse_dollar(as_string, dest, input) != 0) {
6236 debug_printf_parse("parse_stream_dquoted return 1: "
6237 "parse_dollar returned non-0\n");
6242 #if ENABLE_HUSH_TICK
6244 //unsigned pos = dest->length;
6245 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6246 o_addchr(dest, 0x80 | '`');
6247 add_till_backquote(dest, input);
6248 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6249 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6253 o_addQchr(dest, ch);
6255 && (dest->o_assignment == MAYBE_ASSIGNMENT
6256 || dest->o_assignment == WORD_IS_KEYWORD)
6257 && is_well_formed_var_name(dest->data, '=')
6259 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6266 * Scan input until EOF or end_trigger char.
6267 * Return a list of pipes to execute, or NULL on EOF
6268 * or if end_trigger character is met.
6269 * On syntax error, exit is shell is not interactive,
6270 * reset parsing machinery and start parsing anew,
6271 * or return ERR_PTR.
6273 static struct pipe *parse_stream(char **pstring,
6274 struct in_str *input,
6277 struct parse_context ctx;
6278 o_string dest = NULL_O_STRING;
6282 /* Double-quote state is handled in the state variable is_in_dquote.
6283 * A single-quote triggers a bypass of the main loop until its mate is
6284 * found. When recursing, quote state is passed in via dest->o_escape.
6286 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6287 end_trigger ? end_trigger : 'X');
6290 /* If very first arg is "" or '', dest.data may end up NULL.
6291 * Preventing this: */
6292 o_addchr(&dest, '\0');
6295 G.ifs = get_local_var_value("IFS");
6300 #if ENABLE_HUSH_INTERACTIVE
6301 input->promptmode = 0; /* PS1 */
6303 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6304 initialize_context(&ctx);
6309 const char *is_special;
6313 redir_type redir_style;
6316 /* dest.o_quoted = 1; - already is (see below) */
6317 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6320 /* We reached closing '"' */
6323 ch = i_getch(input);
6324 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6325 ch, ch, dest.o_escape);
6330 syntax_error_unterm_str("here document");
6333 /* end_trigger == '}' case errors out earlier,
6334 * checking only ')' */
6335 if (end_trigger == ')') {
6336 syntax_error_unterm_ch('('); /* exits */
6337 /* goto parse_error; */
6340 if (done_word(&dest, &ctx)) {
6344 done_pipe(&ctx, PIPE_SEQ);
6346 /* If we got nothing... */
6347 /* (this makes bare "&" cmd a no-op.
6348 * bash says: "syntax error near unexpected token '&'") */
6349 if (pi->num_cmds == 0
6350 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6356 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6358 *pstring = ctx.as_string.data;
6360 o_free_unsafe(&ctx.as_string);
6363 debug_printf_parse("parse_stream return %p\n", pi);
6366 nommu_addchr(&ctx.as_string, ch);
6370 next = i_peek(input);
6372 is_special = "{}<>;&|()#'" /* special outside of "str" */
6373 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6374 /* Are { and } special here? */
6375 if (ctx.command->argv /* word [word]{... - non-special */
6376 || dest.length /* word{... - non-special */
6377 || dest.o_quoted /* ""{... - non-special */
6378 || (next != ';' /* }; - special */
6379 && next != ')' /* }) - special */
6380 && next != '&' /* }& and }&& ... - special */
6381 && next != '|' /* }|| ... - special */
6382 && !strchr(G.ifs, next) /* {word - non-special */
6385 /* They are not special, skip "{}" */
6388 is_special = strchr(is_special, ch);
6389 is_ifs = strchr(G.ifs, ch);
6391 if (!is_special && !is_ifs) { /* ordinary char */
6393 o_addQchr(&dest, ch);
6394 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6395 || dest.o_assignment == WORD_IS_KEYWORD)
6397 && is_well_formed_var_name(dest.data, '=')
6399 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6405 if (done_word(&dest, &ctx)) {
6409 #if ENABLE_HUSH_CASE
6410 /* "case ... in <newline> word) ..." -
6411 * newlines are ignored (but ';' wouldn't be) */
6412 if (ctx.command->argv == NULL
6413 && ctx.ctx_res_w == RES_MATCH
6418 /* Treat newline as a command separator. */
6419 done_pipe(&ctx, PIPE_SEQ);
6420 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6422 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6427 dest.o_assignment = MAYBE_ASSIGNMENT;
6429 /* note: if (is_ifs) continue;
6430 * will still trigger for us */
6434 /* "cmd}" or "cmd }..." without semicolon or &:
6435 * } is an ordinary char in this case, even inside { cmd; }
6436 * Pathological example: { ""}; } should exec "}" cmd
6439 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6440 || dest.length != 0 /* word} */
6441 || dest.o_quoted /* ""} */
6445 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6446 goto skip_end_trigger;
6447 /* else: } does terminate a group */
6450 if (end_trigger && end_trigger == ch
6451 && (ch != ';' || heredoc_cnt == 0)
6452 #if ENABLE_HUSH_CASE
6454 || ctx.ctx_res_w != RES_MATCH
6455 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6460 /* This is technically valid:
6461 * { cat <<HERE; }; echo Ok
6465 * but we don't support this.
6466 * We require heredoc to be in enclosing {}/(),
6469 syntax_error_unterm_str("here document");
6472 if (done_word(&dest, &ctx)) {
6475 done_pipe(&ctx, PIPE_SEQ);
6476 dest.o_assignment = MAYBE_ASSIGNMENT;
6477 /* Do we sit outside of any if's, loops or case's? */
6479 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6483 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6485 *pstring = ctx.as_string.data;
6487 o_free_unsafe(&ctx.as_string);
6490 debug_printf_parse("parse_stream return %p: "
6491 "end_trigger char found\n",
6493 return ctx.list_head;
6500 /* Catch <, > before deciding whether this word is
6501 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6504 redir_fd = redirect_opt_num(&dest);
6505 if (done_word(&dest, &ctx)) {
6508 redir_style = REDIRECT_OVERWRITE;
6510 redir_style = REDIRECT_APPEND;
6511 ch = i_getch(input);
6512 nommu_addchr(&ctx.as_string, ch);
6515 else if (next == '(') {
6516 syntax_error(">(process) not supported");
6520 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6522 continue; /* back to top of while (1) */
6524 redir_fd = redirect_opt_num(&dest);
6525 if (done_word(&dest, &ctx)) {
6528 redir_style = REDIRECT_INPUT;
6530 redir_style = REDIRECT_HEREDOC;
6532 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6533 ch = i_getch(input);
6534 nommu_addchr(&ctx.as_string, ch);
6535 } else if (next == '>') {
6536 redir_style = REDIRECT_IO;
6537 ch = i_getch(input);
6538 nommu_addchr(&ctx.as_string, ch);
6541 else if (next == '(') {
6542 syntax_error("<(process) not supported");
6546 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6548 continue; /* back to top of while (1) */
6551 if (dest.o_assignment == MAYBE_ASSIGNMENT
6552 /* check that we are not in word in "a=1 2>word b=1": */
6553 && !ctx.pending_redirect
6555 /* ch is a special char and thus this word
6556 * cannot be an assignment */
6557 dest.o_assignment = NOT_ASSIGNMENT;
6560 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6564 if (dest.length == 0) {
6567 if (ch == EOF || ch == '\n')
6570 /* note: we do not add it to &ctx.as_string */
6572 nommu_addchr(&ctx.as_string, '\n');
6574 o_addQchr(&dest, ch);
6579 syntax_error("\\<eof>");
6582 ch = i_getch(input);
6584 o_addchr(&dest, '\\');
6585 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6586 o_addchr(&dest, ch);
6587 nommu_addchr(&ctx.as_string, ch);
6588 /* Example: echo Hello \2>file
6589 * we need to know that word 2 is quoted */
6594 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6595 ctx.as_string.data[--ctx.as_string.length] = '\0';
6600 if (parse_dollar(&ctx.as_string, &dest, input) != 0) {
6601 debug_printf_parse("parse_stream parse error: "
6602 "parse_dollar returned non-0\n");
6609 ch = i_getch(input);
6611 syntax_error_unterm_ch('\'');
6612 /*xfunc_die(); - redundant */
6614 nommu_addchr(&ctx.as_string, ch);
6617 o_addqchr(&dest, ch);
6622 is_in_dquote ^= 1; /* invert */
6623 if (dest.o_assignment == NOT_ASSIGNMENT)
6626 #if ENABLE_HUSH_TICK
6630 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6631 o_addchr(&dest, '`');
6633 add_till_backquote(&dest, input);
6635 o_addstr(&ctx.as_string, dest.data + pos);
6636 o_addchr(&ctx.as_string, '`');
6638 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6639 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6644 #if ENABLE_HUSH_CASE
6647 if (done_word(&dest, &ctx)) {
6650 done_pipe(&ctx, PIPE_SEQ);
6651 #if ENABLE_HUSH_CASE
6652 /* Eat multiple semicolons, detect
6653 * whether it means something special */
6658 ch = i_getch(input);
6659 nommu_addchr(&ctx.as_string, ch);
6660 if (ctx.ctx_res_w == RES_CASE_BODY) {
6661 ctx.ctx_dsemicolon = 1;
6662 ctx.ctx_res_w = RES_MATCH;
6668 /* We just finished a cmd. New one may start
6669 * with an assignment */
6670 dest.o_assignment = MAYBE_ASSIGNMENT;
6673 if (done_word(&dest, &ctx)) {
6677 ch = i_getch(input);
6678 nommu_addchr(&ctx.as_string, ch);
6679 done_pipe(&ctx, PIPE_AND);
6681 done_pipe(&ctx, PIPE_BG);
6685 if (done_word(&dest, &ctx)) {
6688 #if ENABLE_HUSH_CASE
6689 if (ctx.ctx_res_w == RES_MATCH)
6690 break; /* we are in case's "word | word)" */
6692 if (next == '|') { /* || */
6693 ch = i_getch(input);
6694 nommu_addchr(&ctx.as_string, ch);
6695 done_pipe(&ctx, PIPE_OR);
6697 /* we could pick up a file descriptor choice here
6698 * with redirect_opt_num(), but bash doesn't do it.
6699 * "echo foo 2| cat" yields "foo 2". */
6702 o_reset_to_empty_unquoted(&ctx.as_string);
6707 #if ENABLE_HUSH_CASE
6708 /* "case... in [(]word)..." - skip '(' */
6709 if (ctx.ctx_res_w == RES_MATCH
6710 && ctx.command->argv == NULL /* not (word|(... */
6711 && dest.length == 0 /* not word(... */
6712 && dest.o_quoted == 0 /* not ""(... */
6718 if (parse_group(&dest, &ctx, input, ch) != 0) {
6723 #if ENABLE_HUSH_CASE
6724 if (ctx.ctx_res_w == RES_MATCH)
6728 /* proper use of this character is caught by end_trigger:
6729 * if we see {, we call parse_group(..., end_trigger='}')
6730 * and it will match } earlier (not here). */
6731 syntax_error_unexpected_ch(ch);
6735 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6741 struct parse_context *pctx;
6742 IF_HAS_KEYWORDS(struct parse_context *p2;)
6744 /* Clean up allocated tree.
6745 * Sample for finding leaks on syntax error recovery path.
6746 * Run it from interactive shell, watch pmap `pidof hush`.
6747 * while if false; then false; fi; do break; fi
6748 * Samples to catch leaks at execution:
6749 * while if (true | {true;}); then echo ok; fi; do break; done
6750 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6754 /* Update pipe/command counts,
6755 * otherwise freeing may miss some */
6756 done_pipe(pctx, PIPE_SEQ);
6757 debug_printf_clean("freeing list %p from ctx %p\n",
6758 pctx->list_head, pctx);
6759 debug_print_tree(pctx->list_head, 0);
6760 free_pipe_list(pctx->list_head);
6761 debug_printf_clean("freed list %p\n", pctx->list_head);
6763 o_free_unsafe(&pctx->as_string);
6765 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6769 IF_HAS_KEYWORDS(pctx = p2;)
6770 } while (HAS_KEYWORDS && pctx);
6771 /* Free text, clear all dest fields */
6773 /* If we are not in top-level parse, we return,
6774 * our caller will propagate error.
6776 if (end_trigger != ';') {
6784 /* Discard cached input, force prompt */
6786 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6791 /* Executing from string: eval, sh -c '...'
6792 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6793 * end_trigger controls how often we stop parsing
6794 * NUL: parse all, execute, return
6795 * ';': parse till ';' or newline, execute, repeat till EOF
6797 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6799 /* Why we need empty flag?
6800 * An obscure corner case "false; ``; echo $?":
6801 * empty command in `` should still set $? to 0.
6802 * But we can't just set $? to 0 at the start,
6803 * this breaks "false; echo `echo $?`" case.
6807 struct pipe *pipe_list;
6809 pipe_list = parse_stream(NULL, inp, end_trigger);
6810 if (!pipe_list) { /* EOF */
6812 G.last_exitcode = 0;
6815 debug_print_tree(pipe_list, 0);
6816 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6817 run_and_free_list(pipe_list);
6822 static void parse_and_run_string(const char *s)
6824 struct in_str input;
6825 setup_string_in_str(&input, s);
6826 parse_and_run_stream(&input, '\0');
6829 static void parse_and_run_file(FILE *f)
6831 struct in_str input;
6832 setup_file_in_str(&input, f);
6833 parse_and_run_stream(&input, ';');
6836 /* Called a few times only (or even once if "sh -c") */
6837 static void init_sigmasks(void)
6841 sigset_t old_blocked_set;
6843 if (!G.inherited_set_is_saved) {
6844 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6845 G.inherited_set = G.blocked_set;
6847 old_blocked_set = G.blocked_set;
6849 mask = (1 << SIGQUIT);
6850 if (G_interactive_fd) {
6851 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6852 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6853 mask |= SPECIAL_JOB_SIGS;
6855 G.non_DFL_mask = mask;
6860 sigaddset(&G.blocked_set, sig);
6864 sigdelset(&G.blocked_set, SIGCHLD);
6866 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6867 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6869 /* POSIX allows shell to re-enable SIGCHLD
6870 * even if it was SIG_IGN on entry */
6871 #if ENABLE_HUSH_FAST
6872 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6873 if (!G.inherited_set_is_saved)
6874 signal(SIGCHLD, SIGCHLD_handler);
6876 if (!G.inherited_set_is_saved)
6877 signal(SIGCHLD, SIG_DFL);
6880 G.inherited_set_is_saved = 1;
6885 static void maybe_set_to_sigexit(int sig)
6887 void (*handler)(int);
6888 /* non_DFL_mask'ed signals are, well, masked,
6889 * no need to set handler for them.
6891 if (!((G.non_DFL_mask >> sig) & 1)) {
6892 handler = signal(sig, sigexit);
6893 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6894 signal(sig, handler);
6897 /* Set handlers to restore tty pgrp and exit */
6898 static void set_fatal_handlers(void)
6900 /* We _must_ restore tty pgrp on fatal signals */
6902 maybe_set_to_sigexit(SIGILL );
6903 maybe_set_to_sigexit(SIGFPE );
6904 maybe_set_to_sigexit(SIGBUS );
6905 maybe_set_to_sigexit(SIGSEGV);
6906 maybe_set_to_sigexit(SIGTRAP);
6907 } /* else: hush is perfect. what SEGV? */
6908 maybe_set_to_sigexit(SIGABRT);
6909 /* bash 3.2 seems to handle these just like 'fatal' ones */
6910 maybe_set_to_sigexit(SIGPIPE);
6911 maybe_set_to_sigexit(SIGALRM);
6912 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6913 * if we aren't interactive... but in this case
6914 * we never want to restore pgrp on exit, and this fn is not called */
6915 /*maybe_set_to_sigexit(SIGHUP );*/
6916 /*maybe_set_to_sigexit(SIGTERM);*/
6917 /*maybe_set_to_sigexit(SIGINT );*/
6921 static int set_mode(const char cstate, const char mode)
6923 int state = (cstate == '-' ? 1 : 0);
6925 case 'n': G.fake_mode = state; break;
6926 case 'x': /*G.debug_mode = state;*/ break;
6927 default: return EXIT_FAILURE;
6929 return EXIT_SUCCESS;
6932 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6933 int hush_main(int argc, char **argv)
6935 static const struct variable const_shell_ver = {
6937 .varstr = (char*)hush_version_str,
6938 .max_len = 1, /* 0 can provoke free(name) */
6943 unsigned builtin_argc;
6945 struct variable *cur_var;
6948 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6949 G.last_exitcode = EXIT_SUCCESS;
6951 G.argv0_for_re_execing = argv[0];
6953 /* Deal with HUSH_VERSION */
6954 G.shell_ver = const_shell_ver; /* copying struct here */
6955 G.top_var = &G.shell_ver;
6956 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6957 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6958 /* Initialize our shell local variables with the values
6959 * currently living in the environment */
6960 cur_var = G.top_var;
6963 char *value = strchr(*e, '=');
6964 if (value) { /* paranoia */
6965 cur_var->next = xzalloc(sizeof(*cur_var));
6966 cur_var = cur_var->next;
6967 cur_var->varstr = *e;
6968 cur_var->max_len = strlen(*e);
6969 cur_var->flg_export = 1;
6973 /* reinstate HUSH_VERSION */
6974 debug_printf_env("putenv '%s'\n", hush_version_str);
6975 putenv((char *)hush_version_str);
6978 set_pwd_var(/*exp:*/ 1);
6979 /* bash also exports SHLVL and _,
6980 * and sets (but doesn't export) the following variables:
6982 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6983 * BASH_VERSION='3.2.0(1)-release'
6985 * MACHTYPE=i386-pc-linux-gnu
6987 * HOSTNAME=<xxxxxxxxxx>
6988 * PPID=<NNNNN> - we also do it elsewhere
6999 * PIPESTATUS=([0]="0")
7000 * HISTFILE=/<xxx>/.bash_history
7004 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7006 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7016 #if ENABLE_FEATURE_EDITING
7017 G.line_input_state = new_line_input_t(FOR_SHELL);
7019 G.global_argc = argc;
7020 G.global_argv = argv;
7021 /* Initialize some more globals to non-zero values */
7022 cmdedit_update_prompt();
7024 if (setjmp(die_jmp)) {
7025 /* xfunc has failed! die die die */
7026 /* no EXIT traps, this is an escape hatch! */
7028 hush_exit(xfunc_error_retval);
7031 /* Shell is non-interactive at first. We need to call
7032 * init_sigmasks() if we are going to execute "sh <script>",
7033 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7034 * If we later decide that we are interactive, we run init_sigmasks()
7035 * in order to intercept (more) signals.
7039 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7042 opt = getopt(argc, argv, "+c:xins"
7045 # if ENABLE_HUSH_FUNCTIONS
7055 * sh ... -c 'script'
7056 * sh ... -c 'script' ARG0 [ARG1...]
7057 * On NOMMU, if builtin_argc != 0,
7058 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7059 * "" needs to be replaced with NULL
7060 * and BARGV vector fed to builtin function.
7061 * Note: the form without ARG0 never happens:
7062 * sh ... -c 'builtin' BARGV... ""
7065 G.root_pid = getpid();
7066 G.root_ppid = getppid();
7068 G.global_argv = argv + optind;
7069 G.global_argc = argc - optind;
7071 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7072 const struct built_in_command *x;
7075 x = find_builtin(optarg);
7076 if (x) { /* paranoia */
7077 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7078 G.global_argv += builtin_argc;
7079 G.global_argv[-1] = NULL; /* replace "" */
7080 G.last_exitcode = x->b_function(argv + optind - 1);
7084 if (!G.global_argv[0]) {
7085 /* -c 'script' (no params): prevent empty $0 */
7086 G.global_argv--; /* points to argv[i] of 'script' */
7087 G.global_argv[0] = argv[0];
7089 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7091 parse_and_run_string(optarg);
7094 /* Well, we cannot just declare interactiveness,
7095 * we have to have some stuff (ctty, etc) */
7096 /* G_interactive_fd++; */
7099 /* "-s" means "read from stdin", but this is how we always
7100 * operate, so simply do nothing here. */
7103 case '<': /* "big heredoc" support */
7104 full_write1_str(optarg);
7107 unsigned long long empty_trap_mask;
7109 G.root_pid = bb_strtou(optarg, &optarg, 16);
7111 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7113 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7115 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7117 builtin_argc = bb_strtou(optarg, &optarg, 16);
7119 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7120 if (empty_trap_mask != 0) {
7123 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7124 for (sig = 1; sig < NSIG; sig++) {
7125 if (empty_trap_mask & (1LL << sig)) {
7126 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7127 sigaddset(&G.blocked_set, sig);
7130 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7132 # if ENABLE_HUSH_LOOPS
7134 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7140 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7142 # if ENABLE_HUSH_FUNCTIONS
7144 struct function *funcp = new_function(optarg);
7145 /* funcp->name is already set to optarg */
7146 /* funcp->body is set to NULL. It's a special case. */
7147 funcp->body_as_string = argv[optind];
7155 if (!set_mode('-', opt))
7159 fprintf(stderr, "Usage: sh [FILE]...\n"
7160 " or: sh -c command [args]...\n\n");
7166 } /* option parsing loop */
7169 G.root_pid = getpid();
7170 G.root_ppid = getppid();
7173 /* If we are login shell... */
7174 if (argv[0] && argv[0][0] == '-') {
7176 debug_printf("sourcing /etc/profile\n");
7177 input = fopen_for_read("/etc/profile");
7178 if (input != NULL) {
7179 close_on_exec_on(fileno(input));
7181 parse_and_run_file(input);
7184 /* bash: after sourcing /etc/profile,
7185 * tries to source (in the given order):
7186 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7187 * stopping on first found. --noprofile turns this off.
7188 * bash also sources ~/.bash_logout on exit.
7189 * If called as sh, skips .bash_XXX files.
7196 * "bash <script>" (which is never interactive (unless -i?))
7197 * sources $BASH_ENV here (without scanning $PATH).
7198 * If called as sh, does the same but with $ENV.
7200 debug_printf("running script '%s'\n", argv[optind]);
7201 G.global_argv = argv + optind;
7202 G.global_argc = argc - optind;
7203 input = xfopen_for_read(argv[optind]);
7204 close_on_exec_on(fileno(input));
7206 parse_and_run_file(input);
7207 #if ENABLE_FEATURE_CLEAN_UP
7213 /* Up to here, shell was non-interactive. Now it may become one.
7214 * NB: don't forget to (re)run init_sigmasks() as needed.
7217 /* A shell is interactive if the '-i' flag was given,
7218 * or if all of the following conditions are met:
7220 * no arguments remaining or the -s flag given
7221 * standard input is a terminal
7222 * standard output is a terminal
7223 * Refer to Posix.2, the description of the 'sh' utility.
7226 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7227 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7228 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7229 if (G_saved_tty_pgrp < 0)
7230 G_saved_tty_pgrp = 0;
7232 /* try to dup stdin to high fd#, >= 255 */
7233 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7234 if (G_interactive_fd < 0) {
7235 /* try to dup to any fd */
7236 G_interactive_fd = dup(STDIN_FILENO);
7237 if (G_interactive_fd < 0) {
7239 G_interactive_fd = 0;
7240 G_saved_tty_pgrp = 0;
7243 // TODO: track & disallow any attempts of user
7244 // to (inadvertently) close/redirect G_interactive_fd
7246 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7247 if (G_interactive_fd) {
7248 close_on_exec_on(G_interactive_fd);
7250 if (G_saved_tty_pgrp) {
7251 /* If we were run as 'hush &', sleep until we are
7252 * in the foreground (tty pgrp == our pgrp).
7253 * If we get started under a job aware app (like bash),
7254 * make sure we are now in charge so we don't fight over
7255 * who gets the foreground */
7257 pid_t shell_pgrp = getpgrp();
7258 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7259 if (G_saved_tty_pgrp == shell_pgrp)
7261 /* send TTIN to ourself (should stop us) */
7262 kill(- shell_pgrp, SIGTTIN);
7266 /* Block some signals */
7269 if (G_saved_tty_pgrp) {
7270 /* Set other signals to restore saved_tty_pgrp */
7271 set_fatal_handlers();
7272 /* Put ourselves in our own process group
7273 * (bash, too, does this only if ctty is available) */
7274 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7275 /* Grab control of the terminal */
7276 tcsetpgrp(G_interactive_fd, getpid());
7278 /* -1 is special - makes xfuncs longjmp, not exit
7279 * (we reset die_sleep = 0 whereever we [v]fork) */
7280 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7284 #elif ENABLE_HUSH_INTERACTIVE
7285 /* No job control compiled in, only prompt/line editing */
7286 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7287 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7288 if (G_interactive_fd < 0) {
7289 /* try to dup to any fd */
7290 G_interactive_fd = dup(STDIN_FILENO);
7291 if (G_interactive_fd < 0)
7293 G_interactive_fd = 0;
7296 if (G_interactive_fd) {
7297 close_on_exec_on(G_interactive_fd);
7301 /* We have interactiveness code disabled */
7305 * if interactive but not a login shell, sources ~/.bashrc
7306 * (--norc turns this off, --rcfile <file> overrides)
7309 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7310 /* note: ash and hush share this string */
7311 printf("\n\n%s %s\n"
7312 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7315 "hush - the humble shell"
7319 parse_and_run_file(stdin);
7322 #if ENABLE_FEATURE_CLEAN_UP
7323 if (G.cwd != bb_msg_unknown)
7325 cur_var = G.top_var->next;
7327 struct variable *tmp = cur_var;
7328 if (!cur_var->max_len)
7329 free(cur_var->varstr);
7330 cur_var = cur_var->next;
7334 hush_exit(G.last_exitcode);
7339 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7340 int lash_main(int argc, char **argv)
7342 bb_error_msg("lash is deprecated, please use hush instead");
7343 return hush_main(argc, argv);
7348 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7349 int msh_main(int argc, char **argv)
7351 //bb_error_msg("msh is deprecated, please use hush instead");
7352 return hush_main(argc, argv);
7360 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7365 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7372 return applet_main_func(argc, argv - argc);
7375 static int FAST_FUNC builtin_test(char **argv)
7377 return run_applet_main(argv, test_main);
7380 static int FAST_FUNC builtin_echo(char **argv)
7382 return run_applet_main(argv, echo_main);
7386 static int FAST_FUNC builtin_printf(char **argv)
7388 return run_applet_main(argv, printf_main);
7392 static char **skip_dash_dash(char **argv)
7395 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7400 static int FAST_FUNC builtin_eval(char **argv)
7402 int rcode = EXIT_SUCCESS;
7404 argv = skip_dash_dash(argv);
7406 char *str = expand_strvec_to_string(argv);
7408 * eval "echo Hi; done" ("done" is syntax error):
7409 * "echo Hi" will not execute too.
7411 parse_and_run_string(str);
7413 rcode = G.last_exitcode;
7418 static int FAST_FUNC builtin_cd(char **argv)
7422 argv = skip_dash_dash(argv);
7424 if (newdir == NULL) {
7425 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7426 * bash says "bash: cd: HOME not set" and does nothing
7429 const char *home = get_local_var_value("HOME");
7430 newdir = home ? home : "/";
7432 if (chdir(newdir)) {
7433 /* Mimic bash message exactly */
7434 bb_perror_msg("cd: %s", newdir);
7435 return EXIT_FAILURE;
7437 /* Read current dir (get_cwd(1) is inside) and set PWD.
7438 * Note: do not enforce exporting. If PWD was unset or unexported,
7439 * set it again, but do not export. bash does the same.
7441 set_pwd_var(/*exp:*/ 0);
7442 return EXIT_SUCCESS;
7445 static int FAST_FUNC builtin_exec(char **argv)
7447 argv = skip_dash_dash(argv);
7448 if (argv[0] == NULL)
7449 return EXIT_SUCCESS; /* bash does this */
7451 /* Careful: we can end up here after [v]fork. Do not restore
7452 * tty pgrp then, only top-level shell process does that */
7453 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7454 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7456 /* TODO: if exec fails, bash does NOT exit! We do.
7457 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7458 * and tcsetpgrp, and this is inherently racy.
7460 execvp_or_die(argv);
7463 static int FAST_FUNC builtin_exit(char **argv)
7465 debug_printf_exec("%s()\n", __func__);
7467 /* interactive bash:
7468 * # trap "echo EEE" EXIT
7471 * There are stopped jobs.
7472 * (if there are _stopped_ jobs, running ones don't count)
7475 # EEE (then bash exits)
7477 * we can use G.exiting = -1 as indicator "last cmd was exit"
7480 /* note: EXIT trap is run by hush_exit */
7481 argv = skip_dash_dash(argv);
7482 if (argv[0] == NULL)
7483 hush_exit(G.last_exitcode);
7484 /* mimic bash: exit 123abc == exit 255 + error msg */
7485 xfunc_error_retval = 255;
7486 /* bash: exit -2 == exit 254, no error msg */
7487 hush_exit(xatoi(argv[0]) & 0xff);
7490 static void print_escaped(const char *s)
7495 const char *p = strchrnul(s, '\'');
7496 /* print 'xxxx', possibly just '' */
7497 printf("'%.*s'", (int)(p - s), s);
7502 /* s points to '; print "'''...'''" */
7504 do putchar('\''); while (*++s == '\'');
7509 #if !ENABLE_HUSH_LOCAL
7510 #define helper_export_local(argv, exp, lvl) \
7511 helper_export_local(argv, exp)
7513 static void helper_export_local(char **argv, int exp, int lvl)
7518 /* So far we do not check that name is valid (TODO?) */
7520 if (strchr(name, '=') == NULL) {
7521 struct variable *var;
7523 var = get_local_var(name);
7524 if (exp == -1) { /* unexporting? */
7525 /* export -n NAME (without =VALUE) */
7527 var->flg_export = 0;
7528 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7530 } /* else: export -n NOT_EXISTING_VAR: no-op */
7533 if (exp == 1) { /* exporting? */
7534 /* export NAME (without =VALUE) */
7536 var->flg_export = 1;
7537 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7538 putenv(var->varstr);
7542 /* Exporting non-existing variable.
7543 * bash does not put it in environment,
7544 * but remembers that it is exported,
7545 * and does put it in env when it is set later.
7546 * We just set it to "" and export. */
7547 /* Or, it's "local NAME" (without =VALUE).
7548 * bash sets the value to "". */
7549 name = xasprintf("%s=", name);
7551 /* (Un)exporting/making local NAME=VALUE */
7552 name = xstrdup(name);
7554 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7558 static int FAST_FUNC builtin_export(char **argv)
7560 unsigned opt_unexport;
7562 #if ENABLE_HUSH_EXPORT_N
7563 /* "!": do not abort on errors */
7564 opt_unexport = getopt32(argv, "!n");
7565 if (opt_unexport == (uint32_t)-1)
7566 return EXIT_FAILURE;
7573 if (argv[0] == NULL) {
7580 /* ash emits: export VAR='VAL'
7581 * bash: declare -x VAR="VAL"
7582 * we follow ash example */
7583 const char *s = *e++;
7584 const char *p = strchr(s, '=');
7586 if (!p) /* wtf? take next variable */
7589 printf("export %.*s", (int)(p - s) + 1, s);
7590 print_escaped(p + 1);
7594 /*fflush_all(); - done after each builtin anyway */
7596 return EXIT_SUCCESS;
7599 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7601 return EXIT_SUCCESS;
7604 #if ENABLE_HUSH_LOCAL
7605 static int FAST_FUNC builtin_local(char **argv)
7607 if (G.func_nest_level == 0) {
7608 bb_error_msg("%s: not in a function", argv[0]);
7609 return EXIT_FAILURE; /* bash compat */
7611 helper_export_local(argv, 0, G.func_nest_level);
7612 return EXIT_SUCCESS;
7616 static int FAST_FUNC builtin_trap(char **argv)
7622 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7627 /* No args: print all trapped */
7628 for (i = 0; i < NSIG; ++i) {
7631 print_escaped(G.traps[i]);
7632 /* note: bash adds "SIG", but only if invoked
7633 * as "bash". If called as "sh", or if set -o posix,
7634 * then it prints short signal names.
7635 * We are printing short names: */
7636 printf(" %s\n", get_signame(i));
7639 /*fflush_all(); - done after each builtin anyway */
7640 return EXIT_SUCCESS;
7644 /* If first arg is a number: reset all specified signals */
7645 sig = bb_strtou(*argv, NULL, 10);
7651 sig = get_signum(*argv++);
7652 if (sig < 0 || sig >= NSIG) {
7654 /* Mimic bash message exactly */
7655 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7660 G.traps[sig] = xstrdup(new_cmd);
7662 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7663 get_signame(sig), sig, G.traps[sig]);
7665 /* There is no signal for 0 (EXIT) */
7670 sigaddset(&G.blocked_set, sig);
7672 /* There was a trap handler, we are removing it
7673 * (if sig has non-DFL handling,
7674 * we don't need to do anything) */
7675 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7677 sigdelset(&G.blocked_set, sig);
7680 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7684 if (!argv[1]) { /* no second arg */
7685 bb_error_msg("trap: invalid arguments");
7686 return EXIT_FAILURE;
7689 /* First arg is "-": reset all specified to default */
7690 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7691 /* Everything else: set arg as signal handler
7692 * (includes "" case, which ignores signal) */
7693 if (argv[0][0] == '-') {
7694 if (argv[0][1] == '\0') { /* "-" */
7695 /* new_cmd remains NULL: "reset these sigs" */
7698 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7701 /* else: "-something", no special meaning */
7706 goto process_sig_list;
7709 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7710 static int FAST_FUNC builtin_type(char **argv)
7712 int ret = EXIT_SUCCESS;
7718 if (0) {} /* make conditional compile easier below */
7719 /*else if (find_alias(*argv))
7720 type = "an alias";*/
7721 #if ENABLE_HUSH_FUNCTIONS
7722 else if (find_function(*argv))
7723 type = "a function";
7725 else if (find_builtin(*argv))
7726 type = "a shell builtin";
7727 else if ((path = find_in_path(*argv)) != NULL)
7730 bb_error_msg("type: %s: not found", *argv);
7735 printf("%s is %s\n", *argv, type);
7743 /* built-in 'fg' and 'bg' handler */
7744 static int FAST_FUNC builtin_fg_bg(char **argv)
7749 if (!G_interactive_fd)
7750 return EXIT_FAILURE;
7752 /* If they gave us no args, assume they want the last backgrounded task */
7754 for (pi = G.job_list; pi; pi = pi->next) {
7755 if (pi->jobid == G.last_jobid) {
7759 bb_error_msg("%s: no current job", argv[0]);
7760 return EXIT_FAILURE;
7762 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7763 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7764 return EXIT_FAILURE;
7766 for (pi = G.job_list; pi; pi = pi->next) {
7767 if (pi->jobid == jobnum) {
7771 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7772 return EXIT_FAILURE;
7774 /* TODO: bash prints a string representation
7775 * of job being foregrounded (like "sleep 1 | cat") */
7776 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7777 /* Put the job into the foreground. */
7778 tcsetpgrp(G_interactive_fd, pi->pgrp);
7781 /* Restart the processes in the job */
7782 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7783 for (i = 0; i < pi->num_cmds; i++) {
7784 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7785 pi->cmds[i].is_stopped = 0;
7787 pi->stopped_cmds = 0;
7789 i = kill(- pi->pgrp, SIGCONT);
7791 if (errno == ESRCH) {
7792 delete_finished_bg_job(pi);
7793 return EXIT_SUCCESS;
7795 bb_perror_msg("kill (SIGCONT)");
7798 if (argv[0][0] == 'f') {
7800 return checkjobs_and_fg_shell(pi);
7802 return EXIT_SUCCESS;
7806 #if ENABLE_HUSH_HELP
7807 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7809 const struct built_in_command *x;
7812 "Built-in commands:\n"
7813 "------------------\n");
7814 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7816 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7819 return EXIT_SUCCESS;
7824 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7827 const char *status_string;
7829 for (job = G.job_list; job; job = job->next) {
7830 if (job->alive_cmds == job->stopped_cmds)
7831 status_string = "Stopped";
7833 status_string = "Running";
7835 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7837 return EXIT_SUCCESS;
7842 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7847 # ifdef M_TRIM_THRESHOLD
7848 /* Optional. Reduces probability of false positives */
7851 /* Crude attempt to find where "free memory" starts,
7852 * sans fragmentation. */
7854 l = (unsigned long)p;
7857 if (l < (unsigned long)p) l = (unsigned long)p;
7860 if (!G.memleak_value)
7861 G.memleak_value = l;
7863 l -= G.memleak_value;
7870 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7875 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7878 return EXIT_SUCCESS;
7881 static int FAST_FUNC builtin_read(char **argv)
7890 /* "!": do not abort on errors.
7891 * Option string must start with "sr" to match BUILTIN_READ_xxx
7893 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7894 if (read_flags == (uint32_t)-1)
7895 return EXIT_FAILURE;
7898 r = shell_builtin_read(set_local_var_from_halves,
7900 get_local_var_value("IFS"), /* can be NULL */
7908 if ((uintptr_t)r > 1) {
7909 bb_error_msg("%s", r);
7910 r = (char*)(uintptr_t)1;
7913 return (uintptr_t)r;
7916 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7917 * built-in 'set' handler
7919 * set [-abCefhmnuvx] [-o option] [argument...]
7920 * set [+abCefhmnuvx] [+o option] [argument...]
7921 * set -- [argument...]
7924 * Implementations shall support the options in both their hyphen and
7925 * plus-sign forms. These options can also be specified as options to sh.
7927 * Write out all variables and their values: set
7928 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7929 * Turn on the -x and -v options: set -xv
7930 * Unset all positional parameters: set --
7931 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7932 * Set the positional parameters to the expansion of x, even if x expands
7933 * with a leading '-' or '+': set -- $x
7935 * So far, we only support "set -- [argument...]" and some of the short names.
7937 static int FAST_FUNC builtin_set(char **argv)
7940 char **pp, **g_argv;
7941 char *arg = *++argv;
7945 for (e = G.top_var; e; e = e->next)
7947 return EXIT_SUCCESS;
7951 if (!strcmp(arg, "--")) {
7955 if (arg[0] != '+' && arg[0] != '-')
7957 for (n = 1; arg[n]; ++n)
7958 if (set_mode(arg[0], arg[n]))
7960 } while ((arg = *++argv) != NULL);
7961 /* Now argv[0] is 1st argument */
7964 return EXIT_SUCCESS;
7967 /* NB: G.global_argv[0] ($0) is never freed/changed */
7968 g_argv = G.global_argv;
7969 if (G.global_args_malloced) {
7975 G.global_args_malloced = 1;
7976 pp = xzalloc(sizeof(pp[0]) * 2);
7977 pp[0] = g_argv[0]; /* retain $0 */
7980 /* This realloc's G.global_argv */
7981 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7988 return EXIT_SUCCESS;
7990 /* Nothing known, so abort */
7992 bb_error_msg("set: %s: invalid option", arg);
7993 return EXIT_FAILURE;
7996 static int FAST_FUNC builtin_shift(char **argv)
7999 argv = skip_dash_dash(argv);
8003 if (n >= 0 && n < G.global_argc) {
8004 if (G.global_args_malloced) {
8007 free(G.global_argv[m++]);
8010 memmove(&G.global_argv[1], &G.global_argv[n+1],
8011 G.global_argc * sizeof(G.global_argv[0]));
8012 return EXIT_SUCCESS;
8014 return EXIT_FAILURE;
8017 static int FAST_FUNC builtin_source(char **argv)
8019 char *arg_path, *filename;
8022 #if ENABLE_HUSH_FUNCTIONS
8026 argv = skip_dash_dash(argv);
8029 /* bash says: "bash: .: filename argument required" */
8030 return 2; /* bash compat */
8033 if (!strchr(filename, '/')) {
8034 arg_path = find_in_path(filename);
8036 filename = arg_path;
8038 input = fopen_or_warn(filename, "r");
8041 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8042 return EXIT_FAILURE;
8044 close_on_exec_on(fileno(input));
8046 #if ENABLE_HUSH_FUNCTIONS
8047 sv_flg = G.flag_return_in_progress;
8048 /* "we are inside sourced file, ok to use return" */
8049 G.flag_return_in_progress = -1;
8051 save_and_replace_G_args(&sv, argv);
8053 parse_and_run_file(input);
8056 restore_G_args(&sv, argv);
8057 #if ENABLE_HUSH_FUNCTIONS
8058 G.flag_return_in_progress = sv_flg;
8061 return G.last_exitcode;
8064 static int FAST_FUNC builtin_umask(char **argv)
8070 argv = skip_dash_dash(argv);
8072 mode_t old_mask = mask;
8075 rc = bb_parse_mode(argv[0], &mask);
8080 * bash: umask: 'q': invalid symbolic mode operator
8081 * bash: umask: 999: octal number out of range
8083 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8088 printf("%04o\n", (unsigned) mask);
8089 /* fall through and restore mask which we set to 0 */
8093 return !rc; /* rc != 0 - success */
8096 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8097 static int FAST_FUNC builtin_unset(char **argv)
8102 /* "!": do not abort on errors */
8103 /* "+": stop at 1st non-option */
8104 opts = getopt32(argv, "!+vf");
8105 if (opts == (unsigned)-1)
8106 return EXIT_FAILURE;
8108 bb_error_msg("unset: -v and -f are exclusive");
8109 return EXIT_FAILURE;
8115 if (!(opts & 2)) { /* not -f */
8116 if (unset_local_var(*argv)) {
8117 /* unset <nonexistent_var> doesn't fail.
8118 * Error is when one tries to unset RO var.
8119 * Message was printed by unset_local_var. */
8123 #if ENABLE_HUSH_FUNCTIONS
8133 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8134 static int FAST_FUNC builtin_wait(char **argv)
8136 int ret = EXIT_SUCCESS;
8139 argv = skip_dash_dash(argv);
8140 if (argv[0] == NULL) {
8141 /* Don't care about wait results */
8142 /* Note 1: must wait until there are no more children */
8143 /* Note 2: must be interruptible */
8145 * $ sleep 3 & sleep 6 & wait
8150 * $ sleep 3 & sleep 6 & wait
8154 * ^C <-- after ~4 sec from keyboard
8157 sigaddset(&G.blocked_set, SIGCHLD);
8158 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8161 if (errno == ECHILD)
8163 /* Wait for SIGCHLD or any other signal of interest */
8164 /* sigtimedwait with infinite timeout: */
8165 sig = sigwaitinfo(&G.blocked_set, NULL);
8167 sig = check_and_run_traps(sig);
8168 if (sig && sig != SIGCHLD) { /* see note 2 */
8174 sigdelset(&G.blocked_set, SIGCHLD);
8175 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8179 /* This is probably buggy wrt interruptible-ness */
8181 pid_t pid = bb_strtou(*argv, NULL, 10);
8183 /* mimic bash message */
8184 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8185 return EXIT_FAILURE;
8187 if (waitpid(pid, &status, 0) == pid) {
8188 if (WIFSIGNALED(status))
8189 ret = 128 + WTERMSIG(status);
8190 else if (WIFEXITED(status))
8191 ret = WEXITSTATUS(status);
8195 bb_perror_msg("wait %s", *argv);
8204 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8205 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8208 def = bb_strtou(argv[1], NULL, 10);
8209 if (errno || def < def_min || argv[2]) {
8210 bb_error_msg("%s: bad arguments", argv[0]);
8218 #if ENABLE_HUSH_LOOPS
8219 static int FAST_FUNC builtin_break(char **argv)
8222 if (G.depth_of_loop == 0) {
8223 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8224 return EXIT_SUCCESS; /* bash compat */
8226 G.flag_break_continue++; /* BC_BREAK = 1 */
8228 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8229 if (depth == UINT_MAX)
8230 G.flag_break_continue = BC_BREAK;
8231 if (G.depth_of_loop < depth)
8232 G.depth_break_continue = G.depth_of_loop;
8234 return EXIT_SUCCESS;
8237 static int FAST_FUNC builtin_continue(char **argv)
8239 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8240 return builtin_break(argv);
8244 #if ENABLE_HUSH_FUNCTIONS
8245 static int FAST_FUNC builtin_return(char **argv)
8249 if (G.flag_return_in_progress != -1) {
8250 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8251 return EXIT_FAILURE; /* bash compat */
8254 G.flag_return_in_progress = 1;
8257 * out of range: wraps around at 256, does not error out
8258 * non-numeric param:
8259 * f() { false; return qwe; }; f; echo $?
8260 * bash: return: qwe: numeric argument required <== we do this
8261 * 255 <== we also do this
8263 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);