1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
45 * Bash stuff (maybe optionally enable?):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
52 * grep for "TODO" and fix (some of them are easy)
53 * change { and } from special chars to reserved words
54 * $var refs in function do not pick up values set by "var=val func"
56 * follow IFS rules more precisely, including update semantics
57 * figure out what to do with backslash-newline
58 * continuation lines, both explicit and implicit - done?
59 * separate job control from interactiveness
60 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
62 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
64 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
66 /* #include <dmalloc.h> */
73 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
77 /* Debug build knobs */
78 #define LEAK_HUNTING 0
79 #define BUILD_AS_NOMMU 0
80 /* Enable/disable sanity checks. Ok to enable in production,
81 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
82 * Keeping 1 for now even in released versions.
92 # define USE_FOR_NOMMU(...) __VA_ARGS__
93 # define USE_FOR_MMU(...)
96 #if defined SINGLE_APPLET_MAIN
97 /* STANDALONE does not make sense, and won't compile */
98 # undef CONFIG_FEATURE_SH_STANDALONE
99 # undef ENABLE_FEATURE_SH_STANDALONE
100 # undef IF_FEATURE_SH_STANDALONE
101 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
102 # define ENABLE_FEATURE_SH_STANDALONE 0
103 # define IF_FEATURE_SH_STANDALONE(...)
104 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
107 #if !ENABLE_HUSH_INTERACTIVE
108 # undef ENABLE_FEATURE_EDITING
109 # define ENABLE_FEATURE_EDITING 0
110 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
111 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
114 /* Do we support ANY keywords? */
115 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
116 # define HAS_KEYWORDS 1
117 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
118 # define IF_HAS_NO_KEYWORDS(...)
120 # define HAS_KEYWORDS 0
121 # define IF_HAS_KEYWORDS(...)
122 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
125 /* If you comment out one of these below, it will be #defined later
126 * to perform debug printfs to stderr: */
127 #define debug_printf(...) do {} while (0)
128 /* Finer-grained debug switches */
129 #define debug_printf_parse(...) do {} while (0)
130 #define debug_print_tree(a, b) do {} while (0)
131 #define debug_printf_exec(...) do {} while (0)
132 #define debug_printf_env(...) do {} while (0)
133 #define debug_printf_jobs(...) do {} while (0)
134 #define debug_printf_expand(...) do {} while (0)
135 #define debug_printf_glob(...) do {} while (0)
136 #define debug_printf_list(...) do {} while (0)
137 #define debug_printf_subst(...) do {} while (0)
138 #define debug_printf_clean(...) do {} while (0)
140 #define ERR_PTR ((void*)(long)1)
142 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
144 #define SPECIAL_VAR_SYMBOL 3
146 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
148 /* This supports saving pointers malloced in vfork child,
149 * to be freed in the parent.
152 typedef struct nommu_save_t {
156 char **argv_from_re_execing;
160 /* The descrip member of this structure is only used to make
161 * debugging output pretty */
162 static const struct {
164 signed char default_fd;
168 { O_RDONLY, 0, "<" },
169 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
170 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
171 { O_RDONLY, 0, "<<" },
172 { O_CREAT|O_RDWR, 1, "<>" },
173 /* Should not be needed. Bogus default_fd helps in debugging */
174 /* { O_RDONLY, 77, "<<" }, */
177 typedef enum reserved_style {
186 #if ENABLE_HUSH_LOOPS
193 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
198 /* two pseudo-keywords support contrived "case" syntax: */
199 RES_MATCH , /* "word)" */
200 RES_CASEI , /* "this command is inside CASE" */
207 typedef struct o_string {
209 int length; /* position where data is appended */
211 /* Protect newly added chars against globbing
212 * (by prepending \ to *, ?, [, \) */
215 /* At least some part of the string was inside '' or "",
216 * possibly empty one: word"", wo''rd etc. */
218 smallint has_empty_slot;
219 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
222 MAYBE_ASSIGNMENT = 0,
223 DEFINITELY_ASSIGNMENT = 1,
225 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
227 /* Used for initialization: o_string foo = NULL_O_STRING; */
228 #define NULL_O_STRING { NULL }
230 /* I can almost use ordinary FILE*. Is open_memstream() universally
231 * available? Where is it documented? */
232 typedef struct in_str {
234 /* eof_flag=1: last char in ->p is really an EOF */
235 char eof_flag; /* meaningless if ->p == NULL */
237 #if ENABLE_HUSH_INTERACTIVE
239 smallint promptmode; /* 0: PS1, 1: PS2 */
242 int (*get) (struct in_str *);
243 int (*peek) (struct in_str *);
245 #define i_getch(input) ((input)->get(input))
246 #define i_peek(input) ((input)->peek(input))
248 struct redir_struct {
249 struct redir_struct *next;
250 char *rd_filename; /* filename */
251 int rd_fd; /* fd to redirect */
252 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
254 smallint rd_type; /* (enum redir_type) */
255 /* note: for heredocs, rd_filename contains heredoc delimiter,
256 * and subsequently heredoc itself; and rd_dup is a bitmask:
257 * 1: do we need to trim leading tabs?
258 * 2: is heredoc quoted (<<'delim' syntax) ?
261 typedef enum redir_type {
262 REDIRECT_INVALID = 0,
264 REDIRECT_OVERWRITE = 2,
266 REDIRECT_HEREDOC = 4,
268 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
271 REDIRFD_SYNTAX_ERR = -2,
272 REDIRFD_TO_FILE = -1,
273 /* otherwise, rd_fd is redirected to rd_dup */
275 HEREDOC_SKIPTABS = 1,
281 pid_t pid; /* 0 if exited */
282 int assignment_cnt; /* how many argv[i] are assignments? */
283 smallint is_stopped; /* is the command currently running? */
284 smallint grp_type; /* GRP_xxx */
286 #define GRP_SUBSHELL 1
287 #if ENABLE_HUSH_FUNCTIONS
288 # define GRP_FUNCTION 2
290 struct pipe *group; /* if non-NULL, this "command" is { list },
291 * ( list ), or a compound statement */
293 char *group_as_string;
295 #if ENABLE_HUSH_FUNCTIONS
296 struct function *child_func;
297 /* This field is used to prevent a bug here:
298 * while...do f1() {a;}; f1; f1 {b;}; f1; done
299 * When we execute "f1() {a;}" cmd, we create new function and clear
300 * cmd->group, cmd->group_as_string, cmd->argv[0].
301 * when we execute "f1 {b;}", we notice that f1 exists,
302 * and that it's "parent cmd" struct is still "alive",
303 * we put those fields back into cmd->xxx
304 * (struct function has ->parent_cmd ptr to facilitate that).
305 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
306 * Without this trick, loop would execute a;b;b;b;...
307 * instead of correct sequence a;b;a;b;...
308 * When command is freed, it severs the link
309 * (sets ->child_func->parent_cmd to NULL).
312 char **argv; /* command name and arguments */
313 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
314 * and on execution these are substituted with their values.
315 * Substitution can make _several_ words out of one argv[n]!
316 * Example: argv[0]=='.^C*^C.' here: echo .$*.
317 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
319 struct redir_struct *redirects; /* I/O redirections */
321 /* Is there anything in this command at all? */
322 #define IS_NULL_CMD(cmd) \
323 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
328 int num_cmds; /* total number of commands in pipe */
329 int alive_cmds; /* number of commands running (not exited) */
330 int stopped_cmds; /* number of commands alive, but stopped */
332 int jobid; /* job number */
333 pid_t pgrp; /* process group ID for the job */
334 char *cmdtext; /* name of job */
336 struct command *cmds; /* array of commands in pipe */
337 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
338 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
339 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
341 typedef enum pipe_style {
347 /* Is there anything in this pipe at all? */
348 #define IS_NULL_PIPE(pi) \
349 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
351 /* This holds pointers to the various results of parsing */
352 struct parse_context {
353 /* linked list of pipes */
354 struct pipe *list_head;
355 /* last pipe (being constructed right now) */
357 /* last command in pipe (being constructed right now) */
358 struct command *command;
359 /* last redirect in command->redirects list */
360 struct redir_struct *pending_redirect;
366 smallint ctx_inverted; /* "! cmd | cmd" */
368 smallint ctx_dsemicolon; /* ";;" seen */
370 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
372 /* group we are enclosed in:
373 * example: "if pipe1; pipe2; then pipe3; fi"
374 * when we see "if" or "then", we malloc and copy current context,
375 * and make ->stack point to it. then we parse pipeN.
376 * when closing "then" / fi" / whatever is found,
377 * we move list_head into ->stack->command->group,
378 * copy ->stack into current context, and delete ->stack.
379 * (parsing of { list } and ( list ) doesn't use this method)
381 struct parse_context *stack;
385 /* On program start, environ points to initial environment.
386 * putenv adds new pointers into it, unsetenv removes them.
387 * Neither of these (de)allocates the strings.
388 * setenv allocates new strings in malloc space and does putenv,
389 * and thus setenv is unusable (leaky) for shell's purposes */
390 #define setenv(...) setenv_is_leaky_dont_use()
392 struct variable *next;
393 char *varstr; /* points to "name=" portion */
394 int max_len; /* if > 0, name is part of initial env; else name is malloced */
395 smallint flg_export; /* putenv should be done on this var */
396 smallint flg_read_only;
404 #if ENABLE_HUSH_FUNCTIONS
406 struct function *next;
408 struct command *parent_cmd;
411 char *body_as_string;
417 /* "Globals" within this file */
418 /* Sorted roughly by size (smaller offsets == smaller code) */
420 #if ENABLE_HUSH_INTERACTIVE
421 /* 'interactive_fd' is a fd# open to ctty, if we have one
422 * _AND_ if we decided to act interactively */
426 #define G_interactive_fd (G.interactive_fd)
428 #define G_interactive_fd 0
430 #if ENABLE_FEATURE_EDITING
431 line_input_t *line_input_state;
437 pid_t saved_tty_pgrp;
439 struct pipe *job_list;
440 struct pipe *toplevel_list;
442 smallint flag_SIGINT;
443 #if ENABLE_HUSH_LOOPS
444 smallint flag_break_continue;
446 #if ENABLE_HUSH_FUNCTIONS
447 /* 0: outside of a function (or sourced file)
448 * -1: inside of a function, ok to use return builtin
449 * 1: return is invoked, skip all till end of func.
451 smallint flag_return_in_progress;
454 smallint exiting; /* used to prevent EXIT trap recursion */
455 /* These four support $?, $#, and $1 */
456 smalluint last_exitcode;
457 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
458 smalluint global_args_malloced;
459 /* how many non-NULL argv's we have. NB: $# + 1 */
463 char *argv0_for_re_execing;
465 #if ENABLE_HUSH_LOOPS
466 unsigned depth_break_continue;
467 unsigned depth_of_loop;
471 struct variable *top_var; /* = &G.shell_ver (set in main()) */
472 struct variable shell_ver;
473 #if ENABLE_HUSH_FUNCTIONS
474 struct function *top_func;
476 /* Signal and trap handling */
477 // unsigned count_SIGCHLD;
478 // unsigned handled_SIGCHLD;
479 /* which signals have non-DFL handler (even with no traps set)? */
480 unsigned non_DFL_mask;
481 char **traps; /* char *traps[NSIG] */
482 sigset_t blocked_set;
483 sigset_t inherited_set;
485 unsigned long memleak_value;
488 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
490 #define G (*ptr_to_globals)
491 /* Not #defining name to G.name - this quickly gets unwieldy
492 * (too many defines). Also, I actually prefer to see when a variable
493 * is global, thus "G." prefix is a useful hint */
494 #define INIT_G() do { \
495 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
499 /* Function prototypes for builtins */
500 static int builtin_cd(char **argv);
501 static int builtin_echo(char **argv);
502 static int builtin_eval(char **argv);
503 static int builtin_exec(char **argv);
504 static int builtin_exit(char **argv);
505 static int builtin_export(char **argv);
507 static int builtin_fg_bg(char **argv);
508 static int builtin_jobs(char **argv);
511 static int builtin_help(char **argv);
514 static int builtin_memleak(char **argv);
516 static int builtin_pwd(char **argv);
517 static int builtin_read(char **argv);
518 static int builtin_set(char **argv);
519 static int builtin_shift(char **argv);
520 static int builtin_source(char **argv);
521 static int builtin_test(char **argv);
522 static int builtin_trap(char **argv);
523 static int builtin_true(char **argv);
524 static int builtin_umask(char **argv);
525 static int builtin_unset(char **argv);
526 static int builtin_wait(char **argv);
527 #if ENABLE_HUSH_LOOPS
528 static int builtin_break(char **argv);
529 static int builtin_continue(char **argv);
531 #if ENABLE_HUSH_FUNCTIONS
532 static int builtin_return(char **argv);
535 /* Table of built-in functions. They can be forked or not, depending on
536 * context: within pipes, they fork. As simple commands, they do not.
537 * When used in non-forking context, they can change global variables
538 * in the parent shell process. If forked, of course they cannot.
539 * For example, 'unset foo | whatever' will parse and run, but foo will
540 * still be set at the end. */
541 struct built_in_command {
543 int (*function)(char **argv);
546 #define BLTIN(cmd, func, help) { cmd, func, help }
548 #define BLTIN(cmd, func, help) { cmd, func }
552 /* For now, echo and test are unconditionally enabled.
553 * Maybe make it configurable? */
554 static const struct built_in_command bltins[] = {
555 BLTIN("." , builtin_source , "Run commands in a file"),
556 BLTIN(":" , builtin_true , "No-op"),
557 BLTIN("[" , builtin_test , "Test condition"),
559 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
561 #if ENABLE_HUSH_LOOPS
562 BLTIN("break" , builtin_break , "Exit from a loop"),
564 BLTIN("cd" , builtin_cd , "Change directory"),
565 #if ENABLE_HUSH_LOOPS
566 BLTIN("continue", builtin_continue, "Start new loop iteration"),
568 BLTIN("echo" , builtin_echo , "Write to stdout"),
569 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
570 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
571 BLTIN("exit" , builtin_exit , "Exit"),
572 BLTIN("export" , builtin_export , "Set environment variable"),
574 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
577 BLTIN("help" , builtin_help , "List shell built-in commands"),
580 BLTIN("jobs" , builtin_jobs , "List active jobs"),
583 BLTIN("memleak" , builtin_memleak , "Debug tool"),
585 BLTIN("pwd" , builtin_pwd , "Print current directory"),
586 BLTIN("read" , builtin_read , "Input environment variable"),
587 #if ENABLE_HUSH_FUNCTIONS
588 BLTIN("return" , builtin_return , "Return from a function"),
590 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
591 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
592 BLTIN("test" , builtin_test , "Test condition"),
593 BLTIN("trap" , builtin_trap , "Trap signals"),
594 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
595 BLTIN("umask" , builtin_umask , "Set file creation mask"),
596 BLTIN("unset" , builtin_unset , "Unset environment variable"),
597 BLTIN("wait" , builtin_wait , "Wait for process"),
604 /* prevent disasters with G.debug_indent < 0 */
605 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
606 # define debug_enter() (G.debug_indent++)
607 # define debug_leave() (G.debug_indent--)
609 # define indent() ((void)0)
610 # define debug_enter() ((void)0)
611 # define debug_leave() ((void)0)
615 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
618 #ifndef debug_printf_parse
619 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
622 #ifndef debug_printf_exec
623 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
626 #ifndef debug_printf_env
627 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
630 #ifndef debug_printf_jobs
631 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
632 # define DEBUG_JOBS 1
634 # define DEBUG_JOBS 0
637 #ifndef debug_printf_expand
638 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
639 # define DEBUG_EXPAND 1
641 # define DEBUG_EXPAND 0
644 #ifndef debug_printf_glob
645 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
646 # define DEBUG_GLOB 1
648 # define DEBUG_GLOB 0
651 #ifndef debug_printf_list
652 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
655 #ifndef debug_printf_subst
656 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
659 #ifndef debug_printf_clean
660 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
661 # define DEBUG_CLEAN 1
663 # define DEBUG_CLEAN 0
667 static void debug_print_strings(const char *prefix, char **vv)
670 fprintf(stderr, "%s:\n", prefix);
672 fprintf(stderr, " '%s'\n", *vv++);
675 #define debug_print_strings(prefix, vv) ((void)0)
679 /* Leak hunting. Use hush_leaktool.sh for post-processing.
682 static void *xxmalloc(int lineno, size_t size)
684 void *ptr = xmalloc((size + 0xff) & ~0xff);
685 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
688 static void *xxrealloc(int lineno, void *ptr, size_t size)
690 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
691 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
694 static char *xxstrdup(int lineno, const char *str)
696 char *ptr = xstrdup(str);
697 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
700 static void xxfree(void *ptr)
702 fdprintf(2, "free %p\n", ptr);
705 #define xmalloc(s) xxmalloc(__LINE__, s)
706 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
707 #define xstrdup(s) xxstrdup(__LINE__, s)
708 #define free(p) xxfree(p)
712 /* Syntax and runtime errors. They always abort scripts.
713 * In interactive use they usually discard unparsed and/or unexecuted commands
714 * and return to the prompt.
715 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
718 # define die_if_script(lineno, fmt...) die_if_script(fmt)
719 # define syntax_error(lineno, msg) syntax_error(msg)
720 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
721 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
722 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
723 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
726 static void die_if_script(unsigned lineno, const char *fmt, ...)
731 bb_error_msg("hush.c:%u", lineno);
734 bb_verror_msg(fmt, p, NULL);
736 if (!G_interactive_fd)
740 static void syntax_error(unsigned lineno, const char *msg)
743 die_if_script(lineno, "syntax error: %s", msg);
745 die_if_script(lineno, "syntax error", NULL);
748 static void syntax_error_at(unsigned lineno, const char *msg)
750 die_if_script(lineno, "syntax error at '%s'", msg);
753 /* It so happens that all such cases are totally fatal
754 * even if shell is interactive: EOF while looking for closing
755 * delimiter. There is nowhere to read stuff from after that,
756 * it's EOF! The only choice is to terminate.
758 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
759 static void syntax_error_unterm_ch(unsigned lineno, char ch)
764 die_if_script(lineno, "syntax error: unterminated %s", msg);
768 static void syntax_error_unterm_str(unsigned lineno, const char *s)
770 die_if_script(lineno, "syntax error: unterminated %s", s);
773 static void syntax_error_unexpected_ch(unsigned lineno, char ch)
778 die_if_script(lineno, "syntax error: unexpected %s", msg);
782 # undef die_if_script
784 # undef syntax_error_at
785 # undef syntax_error_unterm_ch
786 # undef syntax_error_unterm_str
787 # undef syntax_error_unexpected_ch
789 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
790 # define syntax_error(msg) syntax_error(__LINE__, msg)
791 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
792 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
793 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
794 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
798 #if ENABLE_HUSH_INTERACTIVE
799 static void cmdedit_update_prompt(void);
801 # define cmdedit_update_prompt()
807 static int glob_needed(const char *s)
812 if (*s == '*' || *s == '[' || *s == '?')
819 static int is_well_formed_var_name(const char *s, char terminator)
821 if (!s || !(isalpha(*s) || *s == '_'))
824 while (isalnum(*s) || *s == '_')
826 return *s == terminator;
829 /* Replace each \x with x in place, return ptr past NUL. */
830 static char *unbackslash(char *src)
836 if ((*dst++ = *src++) == '\0')
842 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
863 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
864 v[count1 + count2] = NULL;
867 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
871 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
873 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
874 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
877 #define add_strings_to_strings(strings, add, need_to_dup) \
878 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
881 static char **add_string_to_strings(char **strings, char *add)
886 return add_strings_to_strings(strings, v, /*dup:*/ 0);
889 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
891 char **ptr = add_string_to_strings(strings, add);
892 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
895 #define add_string_to_strings(strings, add) \
896 xx_add_string_to_strings(__LINE__, strings, add)
899 static void putenv_all(char **strings)
904 debug_printf_env("putenv '%s'\n", *strings);
909 static char **putenv_all_and_save_old(char **strings)
919 eq = strchr(*strings, '=');
922 v = getenv(*strings);
925 /* v points to VAL in VAR=VAL, go back to VAR */
926 v -= (eq - *strings) + 1;
927 old = add_string_to_strings(old, v);
936 static void free_strings_and_unsetenv(char **strings, int unset)
946 debug_printf_env("unsetenv '%s'\n", *v);
954 static void free_strings(char **strings)
956 free_strings_and_unsetenv(strings, 0);
960 /* Helpers for setting new $n and restoring them back
962 typedef struct save_arg_t {
966 smallint sv_g_malloced;
969 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
973 sv->sv_argv0 = argv[0];
974 sv->sv_g_argv = G.global_argv;
975 sv->sv_g_argc = G.global_argc;
976 sv->sv_g_malloced = G.global_args_malloced;
978 argv[0] = G.global_argv[0]; /* retain $0 */
979 G.global_argv = argv;
980 G.global_args_malloced = 0;
988 static void restore_G_args(save_arg_t *sv, char **argv)
992 if (G.global_args_malloced) {
993 /* someone ran "set -- arg1 arg2 ...", undo */
995 while (*++pp) /* note: does not free $0 */
999 argv[0] = sv->sv_argv0;
1000 G.global_argv = sv->sv_g_argv;
1001 G.global_argc = sv->sv_g_argc;
1002 G.global_args_malloced = sv->sv_g_malloced;
1006 /* Basic theory of signal handling in shell
1007 * ========================================
1008 * This does not describe what hush does, rather, it is current understanding
1009 * what it _should_ do. If it doesn't, it's a bug.
1010 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1012 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1013 * is finished or backgrounded. It is the same in interactive and
1014 * non-interactive shells, and is the same regardless of whether
1015 * a user trap handler is installed or a shell special one is in effect.
1016 * ^C or ^Z from keyboard seem to execute "at once" because it usually
1017 * backgrounds (i.e. stops) or kills all members of currently running
1020 * Wait builtin in interruptible by signals for which user trap is set
1021 * or by SIGINT in interactive shell.
1023 * Trap handlers will execute even within trap handlers. (right?)
1025 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1027 * If job control is off, backgrounded commands ("cmd &")
1028 * have SIGINT, SIGQUIT set to SIG_IGN.
1030 * Commands run in command substitution ("`cmd`")
1031 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1033 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
1034 * by the shell from its parent.
1036 * Siganls which differ from SIG_DFL action
1037 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1040 * SIGTERM (interactive): ignore
1041 * SIGHUP (interactive):
1042 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1043 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1044 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1045 * that all pipe members are stopped. Try this in bash:
1046 * while :; do :; done - ^Z does not background it
1047 * (while :; do :; done) - ^Z backgrounds it
1048 * SIGINT (interactive): wait for last pipe, ignore the rest
1049 * of the command line, show prompt. NB: ^C does not send SIGINT
1050 * to interactive shell while shell is waiting for a pipe,
1051 * since shell is bg'ed (is not in foreground process group).
1052 * Example 1: this waits 5 sec, but does not execute ls:
1053 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1054 * Example 2: this does not wait and does not execute ls:
1055 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1056 * Example 3: this does not wait 5 sec, but executes ls:
1057 * "sleep 5; ls -l" + press ^C
1059 * (What happens to signals which are IGN on shell start?)
1060 * (What happens with signal mask on shell start?)
1062 * Implementation in hush
1063 * ======================
1064 * We use in-kernel pending signal mask to determine which signals were sent.
1065 * We block all signals which we don't want to take action immediately,
1066 * i.e. we block all signals which need to have special handling as described
1067 * above, and all signals which have traps set.
1068 * After each pipe execution, we extract any pending signals via sigtimedwait()
1071 * unsigned non_DFL_mask: a mask of such "special" signals
1072 * sigset_t blocked_set: current blocked signal set
1075 * clear bit in blocked_set unless it is also in non_DFL_mask
1076 * "trap 'cmd' SIGxxx":
1077 * set bit in blocked_set (even if 'cmd' is '')
1078 * after [v]fork, if we plan to be a shell:
1079 * unblock signals with special interactive handling
1080 * (child shell is not interactive),
1081 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1082 * after [v]fork, if we plan to exec:
1083 * POSIX says pending signal mask is cleared in child - no need to clear it.
1084 * Restore blocked signal set to one inherited by shell just prior to exec.
1086 * Note: as a result, we do not use signal handlers much. The only uses
1087 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
1088 * and to restore tty pgrp on signal-induced exit.
1091 SPECIAL_INTERACTIVE_SIGS = 0
1093 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
1100 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1102 // G.count_SIGCHLD++;
1107 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1108 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1109 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1110 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1112 /* Restores tty foreground process group, and exits.
1113 * May be called as signal handler for fatal signal
1114 * (will resend signal to itself, producing correct exit state)
1115 * or called directly with -EXITCODE.
1116 * We also call it if xfunc is exiting. */
1117 static void sigexit(int sig) NORETURN;
1118 static void sigexit(int sig)
1120 /* Disable all signals: job control, SIGPIPE, etc. */
1121 sigprocmask_allsigs(SIG_BLOCK);
1123 /* Careful: we can end up here after [v]fork. Do not restore
1124 * tty pgrp then, only top-level shell process does that */
1125 if (G_interactive_fd && getpid() == G.root_pid)
1126 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1128 /* Not a signal, just exit */
1132 kill_myself_with_sig(sig); /* does not return */
1136 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1137 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1141 /* Restores tty foreground process group, and exits. */
1142 static void hush_exit(int exitcode) NORETURN;
1143 static void hush_exit(int exitcode)
1145 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1146 /* Prevent recursion:
1147 * trap "echo Hi; exit" EXIT; exit
1149 char *argv[] = { NULL, G.traps[0], NULL };
1157 fflush(NULL); /* flush all streams */
1158 sigexit(- (exitcode & 0xff));
1164 static int check_and_run_traps(int sig)
1166 static const struct timespec zero_timespec = { 0, 0 };
1167 smalluint save_rcode;
1173 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1178 if (G.traps && G.traps[sig]) {
1179 if (G.traps[sig][0]) {
1180 /* We have user-defined handler */
1181 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1182 save_rcode = G.last_exitcode;
1185 G.last_exitcode = save_rcode;
1186 } /* else: "" trap, ignoring signal */
1189 /* not a trap: special action */
1192 // G.count_SIGCHLD++;
1195 /* Builtin was ^C'ed, make it look prettier: */
1202 /* bash is observed to signal whole process groups,
1203 * not individual processes */
1204 for (job = G.job_list; job; job = job->next) {
1207 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1208 if (kill(- job->pgrp, SIGHUP) == 0)
1209 kill(- job->pgrp, SIGCONT);
1214 default: /* ignored: */
1215 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1223 static const char *set_cwd(void)
1225 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1226 * we must not try to free(bb_msg_unknown) */
1227 if (G.cwd == bb_msg_unknown)
1229 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1231 G.cwd = bb_msg_unknown;
1236 /* Get/check local shell variables */
1237 static struct variable *get_local_var(const char *name)
1239 struct variable *cur;
1245 for (cur = G.top_var; cur; cur = cur->next) {
1246 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1252 static const char *get_local_var_value(const char *src)
1254 struct variable *var = get_local_var(src);
1256 return strchr(var->varstr, '=') + 1;
1260 /* str holds "NAME=VAL" and is expected to be malloced.
1261 * We take ownership of it.
1263 * 0: do not change export flag
1264 * (if creating new variable, flag will be 0)
1265 * 1: set export flag and putenv the variable
1266 * -1: clear export flag and unsetenv the variable
1267 * flg_read_only is set only when we handle -R var=val
1270 #define set_local_var(str, flg_export, flg_read_only) \
1271 set_local_var(str, flg_export)
1273 static int set_local_var(char *str, int flg_export, int flg_read_only)
1275 struct variable *cur;
1279 eq_sign = strchr(str, '=');
1280 if (!eq_sign) { /* not expected to ever happen? */
1285 name_len = eq_sign - str + 1; /* including '=' */
1286 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1288 if (strncmp(cur->varstr, str, name_len) != 0) {
1290 /* Bail out. Note that now cur points
1291 * to last var in linked list */
1297 /* We found an existing var with this name */
1298 if (cur->flg_read_only) {
1302 bb_error_msg("%s: readonly variable", str);
1306 if (flg_export == -1) {
1307 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1312 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1317 if (cur->max_len >= strlen(str)) {
1318 /* This one is from startup env, reuse space */
1319 strcpy(cur->varstr, str);
1322 /* max_len == 0 signifies "malloced" var, which we can
1323 * (and has to) free */
1327 goto set_str_and_exp;
1330 /* Not found - create next variable struct */
1331 cur->next = xzalloc(sizeof(*cur));
1337 cur->flg_read_only = flg_read_only;
1340 if (flg_export == 1)
1341 cur->flg_export = 1;
1342 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1343 cmdedit_update_prompt();
1344 if (cur->flg_export) {
1345 if (flg_export == -1) {
1346 cur->flg_export = 0;
1347 /* unsetenv was already done */
1349 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1350 return putenv(cur->varstr);
1356 static int unset_local_var(const char *name)
1358 struct variable *cur;
1359 struct variable *prev = prev; /* for gcc */
1363 return EXIT_SUCCESS;
1364 name_len = strlen(name);
1367 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1368 if (cur->flg_read_only) {
1369 bb_error_msg("%s: readonly variable", name);
1370 return EXIT_FAILURE;
1372 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1373 * is ro, and we cannot reach this code on the 1st pass */
1374 prev->next = cur->next;
1375 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1376 bb_unsetenv(cur->varstr);
1377 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1378 cmdedit_update_prompt();
1382 return EXIT_SUCCESS;
1387 return EXIT_SUCCESS;
1390 #if ENABLE_SH_MATH_SUPPORT
1391 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1392 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1393 static char *endofname(const char *name)
1401 if (!is_in_name(*p))
1407 static void arith_set_local_var(const char *name, const char *val, int flags)
1409 /* arith code doesnt malloc space, so do it for it */
1410 char *var = xasprintf("%s=%s", name, val);
1411 set_local_var(var, flags, 0);
1419 static int static_get(struct in_str *i)
1428 static int static_peek(struct in_str *i)
1433 #if ENABLE_HUSH_INTERACTIVE
1435 static void cmdedit_update_prompt(void)
1437 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1438 G.PS1 = get_local_var_value("PS1");
1441 G.PS2 = get_local_var_value("PS2");
1448 static const char* setup_prompt_string(int promptmode)
1450 const char *prompt_str;
1451 debug_printf("setup_prompt_string %d ", promptmode);
1452 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1453 /* Set up the prompt */
1454 if (promptmode == 0) { /* PS1 */
1456 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1461 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1462 debug_printf("result '%s'\n", prompt_str);
1466 static void get_user_input(struct in_str *i)
1469 const char *prompt_str;
1471 prompt_str = setup_prompt_string(i->promptmode);
1472 #if ENABLE_FEATURE_EDITING
1473 /* Enable command line editing only while a command line
1474 * is actually being read */
1477 /* buglet: SIGINT will not make new prompt to appear _at once_,
1478 * only after <Enter>. (^C will work) */
1479 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1480 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1481 check_and_run_traps(0);
1482 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1483 i->eof_flag = (r < 0);
1484 if (i->eof_flag) { /* EOF/error detected */
1485 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1486 G.user_input_buf[1] = '\0';
1491 fputs(prompt_str, stdout);
1493 G.user_input_buf[0] = r = fgetc(i->file);
1494 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1495 //do we need check_and_run_traps(0)? (maybe only if stdin)
1496 } while (G.flag_SIGINT);
1497 i->eof_flag = (r == EOF);
1499 i->p = G.user_input_buf;
1502 #endif /* INTERACTIVE */
1504 /* This is the magic location that prints prompts
1505 * and gets data back from the user */
1506 static int file_get(struct in_str *i)
1510 /* If there is data waiting, eat it up */
1511 if (i->p && *i->p) {
1512 #if ENABLE_HUSH_INTERACTIVE
1516 if (i->eof_flag && !*i->p)
1518 /* note: ch is never NUL */
1520 /* need to double check i->file because we might be doing something
1521 * more complicated by now, like sourcing or substituting. */
1522 #if ENABLE_HUSH_INTERACTIVE
1523 if (G_interactive_fd && i->promptme && i->file == stdin) {
1526 } while (!*i->p); /* need non-empty line */
1527 i->promptmode = 1; /* PS2 */
1532 do ch = fgetc(i->file); while (ch == '\0');
1534 debug_printf("file_get: got '%c' %d\n", ch, ch);
1535 #if ENABLE_HUSH_INTERACTIVE
1542 /* All callers guarantee this routine will never
1543 * be used right after a newline, so prompting is not needed.
1545 static int file_peek(struct in_str *i)
1548 if (i->p && *i->p) {
1549 if (i->eof_flag && !i->p[1])
1552 /* note: ch is never NUL */
1554 do ch = fgetc(i->file); while (ch == '\0');
1555 i->eof_flag = (ch == EOF);
1556 i->peek_buf[0] = ch;
1557 i->peek_buf[1] = '\0';
1559 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1563 static void setup_file_in_str(struct in_str *i, FILE *f)
1565 i->peek = file_peek;
1567 #if ENABLE_HUSH_INTERACTIVE
1569 i->promptmode = 0; /* PS1 */
1575 static void setup_string_in_str(struct in_str *i, const char *s)
1577 i->peek = static_peek;
1578 i->get = static_get;
1579 #if ENABLE_HUSH_INTERACTIVE
1581 i->promptmode = 0; /* PS1 */
1591 #define B_CHUNK (32 * sizeof(char*))
1593 static void o_reset_to_empty_unquoted(o_string *o)
1601 static void o_free(o_string *o)
1604 memset(o, 0, sizeof(*o));
1607 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1612 static void o_grow_by(o_string *o, int len)
1614 if (o->length + len > o->maxlen) {
1615 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1616 o->data = xrealloc(o->data, 1 + o->maxlen);
1620 static void o_addchr(o_string *o, int ch)
1622 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1624 o->data[o->length] = ch;
1626 o->data[o->length] = '\0';
1629 static void o_addblock(o_string *o, const char *str, int len)
1632 memcpy(&o->data[o->length], str, len);
1634 o->data[o->length] = '\0';
1638 static void o_addstr(o_string *o, const char *str)
1640 o_addblock(o, str, strlen(str));
1642 static void nommu_addchr(o_string *o, int ch)
1648 #define nommu_addchr(o, str) ((void)0)
1651 static void o_addstr_with_NUL(o_string *o, const char *str)
1653 o_addblock(o, str, strlen(str) + 1);
1656 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1661 && (*str != '*' && *str != '?' && *str != '[')
1669 /* My analysis of quoting semantics tells me that state information
1670 * is associated with a destination, not a source.
1672 static void o_addqchr(o_string *o, int ch)
1675 char *found = strchr("*?[\\", ch);
1680 o->data[o->length] = '\\';
1683 o->data[o->length] = ch;
1685 o->data[o->length] = '\0';
1688 static void o_addQchr(o_string *o, int ch)
1691 if (o->o_escape && strchr("*?[\\", ch)) {
1693 o->data[o->length] = '\\';
1697 o->data[o->length] = ch;
1699 o->data[o->length] = '\0';
1702 static void o_addQstr(o_string *o, const char *str, int len)
1705 o_addblock(o, str, len);
1711 int ordinary_cnt = strcspn(str, "*?[\\");
1712 if (ordinary_cnt > len) /* paranoia */
1714 o_addblock(o, str, ordinary_cnt);
1715 if (ordinary_cnt == len)
1717 str += ordinary_cnt;
1718 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1722 if (ch) { /* it is necessarily one of "*?[\\" */
1724 o->data[o->length] = '\\';
1728 o->data[o->length] = ch;
1730 o->data[o->length] = '\0';
1734 /* A special kind of o_string for $VAR and `cmd` expansion.
1735 * It contains char* list[] at the beginning, which is grown in 16 element
1736 * increments. Actual string data starts at the next multiple of 16 * (char*).
1737 * list[i] contains an INDEX (int!) into this string data.
1738 * It means that if list[] needs to grow, data needs to be moved higher up
1739 * but list[i]'s need not be modified.
1740 * NB: remembering how many list[i]'s you have there is crucial.
1741 * o_finalize_list() operation post-processes this structure - calculates
1742 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1744 #if DEBUG_EXPAND || DEBUG_GLOB
1745 static void debug_print_list(const char *prefix, o_string *o, int n)
1747 char **list = (char**)o->data;
1748 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1752 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1753 prefix, list, n, string_start, o->length, o->maxlen);
1756 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1757 o->data + (int)list[i] + string_start,
1758 o->data + (int)list[i] + string_start);
1762 const char *p = o->data + (int)list[n - 1] + string_start;
1764 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1768 #define debug_print_list(prefix, o, n) ((void)0)
1771 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1772 * in list[n] so that it points past last stored byte so far.
1773 * It returns n+1. */
1774 static int o_save_ptr_helper(o_string *o, int n)
1776 char **list = (char**)o->data;
1780 if (!o->has_empty_slot) {
1781 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1782 string_len = o->length - string_start;
1783 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1784 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1785 /* list[n] points to string_start, make space for 16 more pointers */
1786 o->maxlen += 0x10 * sizeof(list[0]);
1787 o->data = xrealloc(o->data, o->maxlen + 1);
1788 list = (char**)o->data;
1789 memmove(list + n + 0x10, list + n, string_len);
1790 o->length += 0x10 * sizeof(list[0]);
1792 debug_printf_list("list[%d]=%d string_start=%d\n",
1793 n, string_len, string_start);
1796 /* We have empty slot at list[n], reuse without growth */
1797 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1798 string_len = o->length - string_start;
1799 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1800 n, string_len, string_start);
1801 o->has_empty_slot = 0;
1803 list[n] = (char*)(ptrdiff_t)string_len;
1807 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1808 static int o_get_last_ptr(o_string *o, int n)
1810 char **list = (char**)o->data;
1811 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1813 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1816 /* o_glob performs globbing on last list[], saving each result
1817 * as a new list[]. */
1818 static int o_glob(o_string *o, int n)
1824 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1826 return o_save_ptr_helper(o, n);
1827 pattern = o->data + o_get_last_ptr(o, n);
1828 debug_printf_glob("glob pattern '%s'\n", pattern);
1829 if (!glob_needed(pattern)) {
1831 o->length = unbackslash(pattern) - o->data;
1832 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1833 return o_save_ptr_helper(o, n);
1836 memset(&globdata, 0, sizeof(globdata));
1837 gr = glob(pattern, 0, NULL, &globdata);
1838 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1839 if (gr == GLOB_NOSPACE)
1840 bb_error_msg_and_die("out of memory during glob");
1841 if (gr == GLOB_NOMATCH) {
1842 globfree(&globdata);
1845 if (gr != 0) { /* GLOB_ABORTED ? */
1846 /* TODO: testcase for bad glob pattern behavior */
1847 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1849 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1850 char **argv = globdata.gl_pathv;
1851 o->length = pattern - o->data; /* "forget" pattern */
1853 o_addstr_with_NUL(o, *argv);
1854 n = o_save_ptr_helper(o, n);
1860 globfree(&globdata);
1862 debug_print_list("o_glob returning", o, n);
1866 /* If o->o_glob == 1, glob the string so far remembered.
1867 * Otherwise, just finish current list[] and start new */
1868 static int o_save_ptr(o_string *o, int n)
1870 if (o->o_glob) { /* if globbing is requested */
1871 /* If o->has_empty_slot, list[n] was already globbed
1872 * (if it was requested back then when it was filled)
1873 * so don't do that again! */
1874 if (!o->has_empty_slot)
1875 return o_glob(o, n); /* o_save_ptr_helper is inside */
1877 return o_save_ptr_helper(o, n);
1880 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1881 static char **o_finalize_list(o_string *o, int n)
1886 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1888 debug_print_list("finalized", o, n);
1889 debug_printf_expand("finalized n:%d\n", n);
1890 list = (char**)o->data;
1891 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1895 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1901 /* Expansion can recurse */
1902 #if ENABLE_HUSH_TICK
1903 static int process_command_subs(o_string *dest, const char *s);
1905 static char *expand_string_to_string(const char *str);
1907 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1908 parse_stream_dquoted(dest, input, dquote_end)
1910 static int parse_stream_dquoted(o_string *as_string,
1912 struct in_str *input,
1915 /* expand_strvec_to_strvec() takes a list of strings, expands
1916 * all variable references within and returns a pointer to
1917 * a list of expanded strings, possibly with larger number
1918 * of strings. (Think VAR="a b"; echo $VAR).
1919 * This new list is allocated as a single malloc block.
1920 * NULL-terminated list of char* pointers is at the beginning of it,
1921 * followed by strings themself.
1922 * Caller can deallocate entire list by single free(list). */
1924 /* Store given string, finalizing the word and starting new one whenever
1925 * we encounter IFS char(s). This is used for expanding variable values.
1926 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1927 static int expand_on_ifs(o_string *output, int n, const char *str)
1930 int word_len = strcspn(str, G.ifs);
1932 if (output->o_escape || !output->o_glob)
1933 o_addQstr(output, str, word_len);
1934 else /* protect backslashes against globbing up :) */
1935 o_addblock_duplicate_backslash(output, str, word_len);
1938 if (!*str) /* EOL - do not finalize word */
1940 o_addchr(output, '\0');
1941 debug_print_list("expand_on_ifs", output, n);
1942 n = o_save_ptr(output, n);
1943 str += strspn(str, G.ifs); /* skip ifs chars */
1945 debug_print_list("expand_on_ifs[1]", output, n);
1949 /* Helper to expand $((...)) and heredoc body. These act as if
1950 * they are in double quotes, with the exception that they are not :).
1951 * Just the rules are similar: "expand only $var and `cmd`"
1953 * Returns malloced string.
1954 * As an optimization, we return NULL if expansion is not needed.
1956 static char *expand_pseudo_dquoted(const char *str)
1959 struct in_str input;
1960 o_string dest = NULL_O_STRING;
1962 if (strchr(str, '$') == NULL
1963 #if ENABLE_HUSH_TICK
1964 && strchr(str, '`') == NULL
1970 /* We need to expand. Example:
1971 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1973 setup_string_in_str(&input, str);
1974 parse_stream_dquoted(NULL, &dest, &input, EOF);
1975 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1976 exp_str = expand_string_to_string(dest.data);
1977 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1978 o_free_unsafe(&dest);
1982 /* Expand all variable references in given string, adding words to list[]
1983 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1984 * to be filled). This routine is extremely tricky: has to deal with
1985 * variables/parameters with whitespace, $* and $@, and constructs like
1986 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1987 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1989 /* or_mask is either 0 (normal case) or 0x80
1990 * (expansion of right-hand side of assignment == 1-element expand.
1991 * It will also do no globbing, and thus we must not backslash-quote!) */
1993 char first_ch, ored_ch;
2001 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
2002 debug_print_list("expand_vars_to_list", output, n);
2003 n = o_save_ptr(output, n);
2004 debug_print_list("expand_vars_to_list[0]", output, n);
2006 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2007 #if ENABLE_HUSH_TICK
2008 o_string subst_result = NULL_O_STRING;
2010 #if ENABLE_SH_MATH_SUPPORT
2011 char arith_buf[sizeof(arith_t)*3 + 2];
2013 o_addblock(output, arg, p - arg);
2014 debug_print_list("expand_vars_to_list[1]", output, n);
2016 p = strchr(p, SPECIAL_VAR_SYMBOL);
2018 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2019 /* "$@" is special. Even if quoted, it can still
2020 * expand to nothing (not even an empty string) */
2021 if ((first_ch & 0x7f) != '@')
2022 ored_ch |= first_ch;
2025 switch (first_ch & 0x7f) {
2026 /* Highest bit in first_ch indicates that var is double-quoted */
2028 val = utoa(G.root_pid);
2030 case '!': /* bg pid */
2031 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2033 case '?': /* exitcode */
2034 val = utoa(G.last_exitcode);
2036 case '#': /* argc */
2037 if (arg[1] != SPECIAL_VAR_SYMBOL)
2038 /* actually, it's a ${#var} */
2040 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2045 if (!G.global_argv[i])
2047 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2048 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2049 smallint sv = output->o_escape;
2050 /* unquoted var's contents should be globbed, so don't escape */
2051 output->o_escape = 0;
2052 while (G.global_argv[i]) {
2053 n = expand_on_ifs(output, n, G.global_argv[i]);
2054 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2055 if (G.global_argv[i++][0] && G.global_argv[i]) {
2056 /* this argv[] is not empty and not last:
2057 * put terminating NUL, start new word */
2058 o_addchr(output, '\0');
2059 debug_print_list("expand_vars_to_list[2]", output, n);
2060 n = o_save_ptr(output, n);
2061 debug_print_list("expand_vars_to_list[3]", output, n);
2064 output->o_escape = sv;
2066 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2067 * and in this case should treat it like '$*' - see 'else...' below */
2068 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2070 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2071 if (++i >= G.global_argc)
2073 o_addchr(output, '\0');
2074 debug_print_list("expand_vars_to_list[4]", output, n);
2075 n = o_save_ptr(output, n);
2077 } else { /* quoted $*: add as one word */
2079 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2080 if (!G.global_argv[++i])
2083 o_addchr(output, G.ifs[0]);
2087 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2088 /* "Empty variable", used to make "" etc to not disappear */
2092 #if ENABLE_HUSH_TICK
2093 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2096 /* Can't just stuff it into output o_string,
2097 * expanded result may need to be globbed
2098 * and $IFS-splitted */
2099 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2100 process_command_subs(&subst_result, arg);
2101 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2102 val = subst_result.data;
2105 #if ENABLE_SH_MATH_SUPPORT
2106 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2107 arith_eval_hooks_t hooks;
2112 arg++; /* skip '+' */
2113 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2114 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2116 exp_str = expand_pseudo_dquoted(arg);
2117 hooks.lookupvar = get_local_var_value;
2118 hooks.setvar = arith_set_local_var;
2119 hooks.endofname = endofname;
2120 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2124 const char *msg = "error in arithmetic";
2127 msg = "exponent less than 0";
2130 msg = "divide by 0";
2133 msg = "expression recursion loop detected";
2138 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2139 sprintf(arith_buf, arith_t_fmt, res);
2144 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2146 bool exp_len = false;
2147 bool exp_null = false;
2149 char exp_save = exp_save; /* for compiler */
2150 char exp_op = exp_op; /* for compiler */
2151 char *exp_word = exp_word; /* for compiler */
2155 arg[0] = first_ch & 0x7f;
2157 /* prepare for expansions */
2158 if (var[0] == '#') {
2159 /* handle length expansion ${#var} */
2163 /* maybe handle parameter expansion */
2164 exp_off = strcspn(var, ":-=+?%#");
2168 exp_save = var[exp_off];
2169 exp_null = exp_save == ':';
2170 exp_word = var + exp_off;
2173 exp_op = *exp_word++;
2174 var[exp_off] = '\0';
2178 /* lookup the variable in question */
2179 if (isdigit(var[0])) {
2180 /* handle_dollar() should have vetted var for us */
2182 if (i < G.global_argc)
2183 val = G.global_argv[i];
2184 /* else val remains NULL: $N with too big N */
2186 val = get_local_var_value(var);
2188 /* handle any expansions */
2190 debug_printf_expand("expand: length of '%s' = ", val);
2191 val = utoa(val ? strlen(val) : 0);
2192 debug_printf_expand("%s\n", val);
2193 } else if (exp_off) {
2194 if (exp_op == '%' || exp_op == '#') {
2196 /* we need to do a pattern match */
2199 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2200 if (exp_op == *exp_word) /* ## or %% */
2202 val = dyn_val = xstrdup(val);
2203 loc = scan(dyn_val, exp_word, zero);
2210 /* we need to do an expansion */
2211 int exp_test = (!val || (exp_null && !val[0]));
2213 exp_test = !exp_test;
2214 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2215 exp_null ? "true" : "false", exp_test);
2217 if (exp_op == '?') {
2218 //TODO: how interactive bash aborts expansion mid-command?
2219 /* ${var?[error_msg_if_unset]} */
2220 /* ${var:?[error_msg_if_unset_or_null]} */
2221 /* mimic bash message */
2222 die_if_script("%s: %s",
2224 exp_word[0] ? exp_word : "parameter null or not set"
2230 if (exp_op == '=') {
2231 /* ${var=[word]} or ${var:=[word]} */
2232 if (isdigit(var[0]) || var[0] == '#') {
2233 /* mimic bash message */
2234 die_if_script("$%s: cannot assign in this way", var);
2237 char *new_var = xasprintf("%s=%s", var, val);
2238 set_local_var(new_var, 0, 0);
2244 var[exp_off] = exp_save;
2248 #if ENABLE_HUSH_TICK
2251 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2252 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2254 /* unquoted var's contents should be globbed, so don't escape */
2255 smallint sv = output->o_escape;
2256 output->o_escape = 0;
2257 n = expand_on_ifs(output, n, val);
2259 output->o_escape = sv;
2261 } else { /* quoted $VAR, val will be appended below */
2262 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2265 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2267 o_addQstr(output, val, strlen(val));
2271 /* Do the check to avoid writing to a const string */
2272 if (*p != SPECIAL_VAR_SYMBOL)
2273 *p = SPECIAL_VAR_SYMBOL;
2275 #if ENABLE_HUSH_TICK
2276 o_free(&subst_result);
2279 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2282 debug_print_list("expand_vars_to_list[a]", output, n);
2283 /* this part is literal, and it was already pre-quoted
2284 * if needed (much earlier), do not use o_addQstr here! */
2285 o_addstr_with_NUL(output, arg);
2286 debug_print_list("expand_vars_to_list[b]", output, n);
2287 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2288 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2291 /* allow to reuse list[n] later without re-growth */
2292 output->has_empty_slot = 1;
2294 o_addchr(output, '\0');
2299 static char **expand_variables(char **argv, int or_mask)
2304 o_string output = NULL_O_STRING;
2306 if (or_mask & 0x100) {
2307 output.o_escape = 1; /* protect against globbing for "$var" */
2308 /* (unquoted $var will temporarily switch it off) */
2315 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2318 debug_print_list("expand_variables", &output, n);
2320 /* output.data (malloced in one block) gets returned in "list" */
2321 list = o_finalize_list(&output, n);
2322 debug_print_strings("expand_variables[1]", list);
2326 static char **expand_strvec_to_strvec(char **argv)
2328 return expand_variables(argv, 0x100);
2331 /* Used for expansion of right hand of assignments */
2332 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2334 static char *expand_string_to_string(const char *str)
2336 char *argv[2], **list;
2338 argv[0] = (char*)str;
2340 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2342 if (!list[0] || list[1])
2343 bb_error_msg_and_die("BUG in varexp2");
2344 /* actually, just move string 2*sizeof(char*) bytes back */
2345 overlapping_strcpy((char*)list, list[0]);
2346 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2350 /* Used for "eval" builtin */
2351 static char* expand_strvec_to_string(char **argv)
2355 list = expand_variables(argv, 0x80);
2356 /* Convert all NULs to spaces */
2361 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2362 bb_error_msg_and_die("BUG in varexp3");
2363 /* bash uses ' ' regardless of $IFS contents */
2368 overlapping_strcpy((char*)list, list[0]);
2369 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2373 static char **expand_assignments(char **argv, int count)
2377 /* Expand assignments into one string each */
2378 for (i = 0; i < count; i++) {
2379 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2387 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2389 static void reset_traps_to_defaults(void)
2391 /* This function is always called in a child shell
2392 * after fork (not vfork, NOMMU doesn't use this function).
2393 * Child shells are not interactive.
2394 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2395 * Testcase: (while :; do :; done) + ^Z should background.
2396 * Same goes for SIGTERM, SIGHUP, SIGINT.
2401 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2404 /* Stupid. It can be done with *single* &= op, but we can't use
2405 * the fact that G.blocked_set is implemented as a bitmask... */
2406 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2410 sigdelset(&G.blocked_set, sig);
2417 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2418 mask = G.non_DFL_mask;
2419 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2423 G.traps[sig] = NULL;
2424 /* There is no signal for 0 (EXIT) */
2427 /* There was a trap handler, we are removing it.
2428 * But if sig still has non-DFL handling,
2429 * we should not unblock it. */
2432 sigdelset(&G.blocked_set, sig);
2434 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2439 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2440 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2442 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2443 char *heredoc_argv[4];
2444 struct variable *cur;
2445 #if ENABLE_HUSH_FUNCTIONS
2446 struct function *funcp;
2451 if (!g_argv0) { /* heredoc */
2452 argv = heredoc_argv;
2453 argv[0] = (char *) G.argv0_for_re_execing;
2454 argv[1] = (char *) "-<";
2455 argv[2] = (char *) s;
2457 pp = &argv[3]; /* used as pointer to empty environment */
2461 sprintf(param_buf, "-$%x:%x:%x" IF_HUSH_LOOPS(":%x")
2462 , (unsigned) G.root_pid
2463 , (unsigned) G.last_bg_pid
2464 , (unsigned) G.last_exitcode
2465 IF_HUSH_LOOPS(, G.depth_of_loop)
2467 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2468 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2471 for (cur = G.top_var; cur; cur = cur->next) {
2472 if (!cur->flg_export || cur->flg_read_only)
2475 #if ENABLE_HUSH_FUNCTIONS
2476 for (funcp = G.top_func; funcp; funcp = funcp->next)
2482 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2483 *pp++ = (char *) G.argv0_for_re_execing;
2485 for (cur = G.top_var; cur; cur = cur->next) {
2486 if (cur->varstr == hush_version_str)
2488 if (cur->flg_read_only) {
2489 *pp++ = (char *) "-R";
2490 *pp++ = cur->varstr;
2491 } else if (!cur->flg_export) {
2492 *pp++ = (char *) "-V";
2493 *pp++ = cur->varstr;
2496 #if ENABLE_HUSH_FUNCTIONS
2497 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2498 *pp++ = (char *) "-F";
2499 *pp++ = funcp->name;
2500 *pp++ = funcp->body_as_string;
2503 /* We can pass activated traps here. Say, -Tnn:trap_string
2505 * However, POSIX says that subshells reset signals with traps
2507 * I tested bash-3.2 and it not only does that with true subshells
2508 * of the form ( list ), but with any forked children shells.
2509 * I set trap "echo W" WINCH; and then tried:
2511 * { echo 1; sleep 20; echo 2; } &
2512 * while true; do echo 1; sleep 20; echo 2; break; done &
2513 * true | { echo 1; sleep 20; echo 2; } | cat
2515 * In all these cases sending SIGWINCH to the child shell
2516 * did not run the trap. If I add trap "echo V" WINCH;
2517 * _inside_ group (just before echo 1), it works.
2519 * I conclude it means we don't need to pass active traps here.
2520 * exec syscall below resets them to SIG_DFL for us.
2522 *pp++ = (char *) "-c";
2527 /* *pp = NULL; - is already there */
2531 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2532 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2533 execve(bb_busybox_exec_path, argv, pp);
2534 /* Fallback. Useful for init=/bin/hush usage etc */
2535 if (argv[0][0] == '/')
2536 execve(argv[0], argv, pp);
2537 xfunc_error_retval = 127;
2538 bb_error_msg_and_die("can't re-execute the shell");
2540 #endif /* !BB_MMU */
2543 static void setup_heredoc(struct redir_struct *redir)
2545 struct fd_pair pair;
2548 /* the _body_ of heredoc (misleading field name) */
2549 const char *heredoc = redir->rd_filename;
2556 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2557 expanded = expand_pseudo_dquoted(heredoc);
2561 len = strlen(heredoc);
2563 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2565 xmove_fd(pair.rd, redir->rd_fd);
2567 /* Try writing without forking. Newer kernels have
2568 * dynamically growing pipes. Must use non-blocking write! */
2571 written = write(pair.wr, heredoc, len);
2582 ndelay_off(pair.wr);
2584 /* Okay, pipe buffer was not big enough */
2585 /* Note: we must not create a stray child (bastard? :)
2586 * for the unsuspecting parent process. Child creates a grandchild
2587 * and exits before parent execs the process which consumes heredoc
2588 * (that exec happens after we return from this function) */
2594 bb_perror_msg_and_die("vfork");
2597 disable_restore_tty_pgrp_on_exit();
2598 pid = BB_MMU ? fork() : vfork();
2600 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2604 close(redir->rd_fd); /* read side of the pipe */
2606 full_write(pair.wr, heredoc, len); /* may loop or block */
2609 /* Delegate blocking writes to another process */
2610 xmove_fd(pair.wr, STDOUT_FILENO);
2611 re_execute_shell(&to_free, heredoc, NULL, NULL);
2615 enable_restore_tty_pgrp_on_exit();
2621 wait(NULL); /* wait till child has died */
2624 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2625 * and stderr if they are redirected. */
2626 static int setup_redirects(struct command *prog, int squirrel[])
2629 struct redir_struct *redir;
2631 for (redir = prog->redirects; redir; redir = redir->next) {
2632 if (redir->rd_type == REDIRECT_HEREDOC2) {
2633 /* rd_fd<<HERE case */
2634 if (squirrel && redir->rd_fd < 3) {
2635 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2637 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2639 debug_printf_parse("set heredoc '%s'\n",
2640 redir->rd_filename);
2641 setup_heredoc(redir);
2645 if (redir->rd_dup == REDIRFD_TO_FILE) {
2646 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2648 if (redir->rd_filename == NULL) {
2649 /* Something went wrong in the parse.
2650 * Pretend it didn't happen */
2651 bb_error_msg("bug in redirect parse");
2654 mode = redir_table[redir->rd_type].mode;
2655 p = expand_string_to_string(redir->rd_filename);
2656 openfd = open_or_warn(p, mode);
2659 /* this could get lost if stderr has been redirected, but
2660 * bash and ash both lose it as well (though zsh doesn't!) */
2661 //what the above comment tries to say?
2665 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2666 openfd = redir->rd_dup;
2669 if (openfd != redir->rd_fd) {
2670 if (squirrel && redir->rd_fd < 3) {
2671 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2673 if (openfd == REDIRFD_CLOSE) {
2674 /* "n>-" means "close me" */
2675 close(redir->rd_fd);
2677 xdup2(openfd, redir->rd_fd);
2678 if (redir->rd_dup == REDIRFD_TO_FILE)
2686 static void restore_redirects(int squirrel[])
2689 for (i = 0; i < 3; i++) {
2692 /* We simply die on error */
2699 static void free_pipe_list(struct pipe *head);
2701 /* Return code is the exit status of the pipe */
2702 static void free_pipe(struct pipe *pi)
2705 struct command *command;
2706 struct redir_struct *r, *rnext;
2709 if (pi->stopped_cmds > 0) /* why? */
2711 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2712 for (i = 0; i < pi->num_cmds; i++) {
2713 command = &pi->cmds[i];
2714 debug_printf_clean(" command %d:\n", i);
2715 if (command->argv) {
2716 for (a = 0, p = command->argv; *p; a++, p++) {
2717 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2719 free_strings(command->argv);
2720 command->argv = NULL;
2722 /* not "else if": on syntax error, we may have both! */
2723 if (command->group) {
2724 debug_printf_clean(" begin group (grp_type:%d)\n",
2726 free_pipe_list(command->group);
2727 debug_printf_clean(" end group\n");
2728 command->group = NULL;
2730 /* else is crucial here.
2731 * If group != NULL, child_func is meaningless */
2732 #if ENABLE_HUSH_FUNCTIONS
2733 else if (command->child_func) {
2734 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2735 command->child_func->parent_cmd = NULL;
2739 free(command->group_as_string);
2740 command->group_as_string = NULL;
2742 for (r = command->redirects; r; r = rnext) {
2743 debug_printf_clean(" redirect %d%s",
2744 r->rd_fd, redir_table[r->rd_type].descrip);
2745 /* guard against the case >$FOO, where foo is unset or blank */
2746 if (r->rd_filename) {
2747 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2748 free(r->rd_filename);
2749 r->rd_filename = NULL;
2751 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2755 command->redirects = NULL;
2757 free(pi->cmds); /* children are an array, they get freed all at once */
2765 static void free_pipe_list(struct pipe *head)
2767 struct pipe *pi, *next;
2769 for (pi = head; pi; pi = next) {
2771 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2774 debug_printf_clean("pipe followup code %d\n", pi->followup);
2776 /*pi->next = NULL;*/
2782 static int run_list(struct pipe *pi);
2784 #define parse_stream(pstring, input, end_trigger) \
2785 parse_stream(input, end_trigger)
2787 static struct pipe *parse_stream(char **pstring,
2788 struct in_str *input,
2790 static void parse_and_run_string(const char *s);
2793 static const struct built_in_command* find_builtin(const char *name)
2795 const struct built_in_command *x;
2796 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2797 if (strcmp(name, x->cmd) != 0)
2799 debug_printf_exec("found builtin '%s'\n", name);
2805 #if ENABLE_HUSH_FUNCTIONS
2806 static const struct function *find_function(const char *name)
2808 const struct function *funcp = G.top_func;
2810 if (strcmp(name, funcp->name) == 0) {
2813 funcp = funcp->next;
2816 debug_printf_exec("found function '%s'\n", name);
2820 /* Note: takes ownership on name ptr */
2821 static struct function *new_function(char *name)
2823 struct function *funcp;
2824 struct function **funcpp = &G.top_func;
2826 while ((funcp = *funcpp) != NULL) {
2827 struct command *cmd;
2829 if (strcmp(funcp->name, name) != 0) {
2830 funcpp = &funcp->next;
2834 cmd = funcp->parent_cmd;
2835 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2837 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2839 /* Note: if !funcp->body, do not free body_as_string!
2840 * This is a special case of "-F name body" function:
2841 * body_as_string was not malloced! */
2843 free_pipe_list(funcp->body);
2845 free(funcp->body_as_string);
2849 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2850 cmd->argv[0] = funcp->name;
2851 cmd->group = funcp->body;
2853 cmd->group_as_string = funcp->body_as_string;
2858 debug_printf_exec("remembering new function '%s'\n", name);
2859 funcp = *funcpp = xzalloc(sizeof(*funcp));
2860 /*funcp->next = NULL;*/
2866 static void unset_func(const char *name)
2868 struct function *funcp;
2869 struct function **funcpp = &G.top_func;
2871 while ((funcp = *funcpp) != NULL) {
2872 if (strcmp(funcp->name, name) == 0) {
2873 *funcpp = funcp->next;
2874 /* funcp is unlinked now, deleting it */
2876 /* Note: if !funcp->body, do not free body_as_string!
2877 * This is a special case of "-F name body" function:
2878 * body_as_string was not malloced! */
2880 free_pipe_list(funcp->body);
2882 free(funcp->body_as_string);
2888 funcpp = &funcp->next;
2893 #define exec_function(nommu_save, funcp, argv) \
2894 exec_function(funcp, argv)
2896 static void exec_function(nommu_save_t *nommu_save,
2897 const struct function *funcp,
2898 char **argv) NORETURN;
2899 static void exec_function(nommu_save_t *nommu_save,
2900 const struct function *funcp,
2906 argv[0] = G.global_argv[0];
2907 G.global_argv = argv;
2911 /* On MMU, funcp->body is always non-NULL */
2912 n = run_list(funcp->body);
2916 re_execute_shell(&nommu_save->argv_from_re_execing,
2917 funcp->body_as_string,
2923 static int run_function(const struct function *funcp, char **argv)
2927 #if ENABLE_HUSH_FUNCTIONS
2931 save_and_replace_G_args(&sv, argv);
2932 #if ENABLE_HUSH_FUNCTIONS
2933 /* "we are in function, ok to use return" */
2934 sv_flg = G.flag_return_in_progress;
2935 G.flag_return_in_progress = -1;
2938 /* On MMU, funcp->body is always non-NULL */
2941 /* Function defined by -F */
2942 parse_and_run_string(funcp->body_as_string);
2943 rc = G.last_exitcode;
2947 rc = run_list(funcp->body);
2950 #if ENABLE_HUSH_FUNCTIONS
2951 G.flag_return_in_progress = sv_flg;
2953 restore_G_args(&sv, argv);
2961 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2962 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2963 #define pseudo_exec(nommu_save, command, argv_expanded) \
2964 pseudo_exec(command, argv_expanded)
2967 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2969 * Don't exit() here. If you don't exec, use _exit instead.
2970 * The at_exit handlers apparently confuse the calling process,
2971 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2972 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2973 char **argv, int assignment_cnt,
2974 char **argv_expanded) NORETURN;
2975 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2976 char **argv, int assignment_cnt,
2977 char **argv_expanded)
2981 /* Case when we are here: ... | var=val | ... */
2982 if (!argv[assignment_cnt])
2983 _exit(EXIT_SUCCESS);
2985 new_env = expand_assignments(argv, assignment_cnt);
2987 putenv_all(new_env);
2988 free(new_env); /* optional */
2990 nommu_save->new_env = new_env;
2991 nommu_save->old_env = putenv_all_and_save_old(new_env);
2993 if (argv_expanded) {
2994 argv = argv_expanded;
2996 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2998 nommu_save->argv = argv;
3002 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3003 if (strchr(argv[0], '/') != NULL)
3007 /* On NOMMU, we must never block!
3008 * Example: { sleep 99999 | read line } & echo Ok
3009 * read builtin will block on read syscall, leaving parent blocked
3010 * in vfork. Therefore we can't do this:
3013 /* Check if the command matches any of the builtins.
3014 * Depending on context, this might be redundant. But it's
3015 * easier to waste a few CPU cycles than it is to figure out
3016 * if this is one of those cases.
3020 const struct built_in_command *x = find_builtin(argv[0]);
3022 rcode = x->function(argv);
3028 #if ENABLE_HUSH_FUNCTIONS
3029 /* Check if the command matches any functions */
3031 const struct function *funcp = find_function(argv[0]);
3033 exec_function(nommu_save, funcp, argv);
3038 #if ENABLE_FEATURE_SH_STANDALONE
3039 /* Check if the command matches any busybox applets */
3041 int a = find_applet_by_name(argv[0]);
3043 # if BB_MMU /* see above why on NOMMU it is not allowed */
3044 if (APPLET_IS_NOEXEC(a)) {
3045 debug_printf_exec("running applet '%s'\n", argv[0]);
3046 run_applet_no_and_exit(a, argv);
3049 /* Re-exec ourselves */
3050 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3051 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3052 execv(bb_busybox_exec_path, argv);
3053 /* If they called chroot or otherwise made the binary no longer
3054 * executable, fall through */
3059 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3062 debug_printf_exec("execing '%s'\n", argv[0]);
3063 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3064 execvp(argv[0], argv);
3065 bb_perror_msg("can't execute '%s'", argv[0]);
3066 _exit(EXIT_FAILURE);
3069 /* Called after [v]fork() in run_pipe
3071 static void pseudo_exec(nommu_save_t *nommu_save,
3072 struct command *command,
3073 char **argv_expanded) NORETURN;
3074 static void pseudo_exec(nommu_save_t *nommu_save,
3075 struct command *command,
3076 char **argv_expanded)
3078 if (command->argv) {
3079 pseudo_exec_argv(nommu_save, command->argv,
3080 command->assignment_cnt, argv_expanded);
3083 if (command->group) {
3084 /* Cases when we are here:
3087 * ... | ( list ) | ...
3088 * ... | { list } | ...
3092 debug_printf_exec("pseudo_exec: run_list\n");
3093 reset_traps_to_defaults();
3094 rcode = run_list(command->group);
3095 /* OK to leak memory by not calling free_pipe_list,
3096 * since this process is about to exit */
3099 re_execute_shell(&nommu_save->argv_from_re_execing,
3100 command->group_as_string,
3106 /* Case when we are here: ... | >file */
3107 debug_printf_exec("pseudo_exec'ed null command\n");
3108 _exit(EXIT_SUCCESS);
3112 static const char *get_cmdtext(struct pipe *pi)
3118 /* This is subtle. ->cmdtext is created only on first backgrounding.
3119 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3120 * On subsequent bg argv is trashed, but we won't use it */
3123 argv = pi->cmds[0].argv;
3124 if (!argv || !argv[0]) {
3125 pi->cmdtext = xzalloc(1);
3131 len += strlen(*argv) + 1;
3134 pi->cmdtext = p;// = xmalloc(len);
3135 argv = pi->cmds[0].argv;
3137 len = strlen(*argv);
3138 memcpy(p, *argv, len);
3146 static void insert_bg_job(struct pipe *pi)
3148 struct pipe *job, **jobp;
3151 /* Linear search for the ID of the job to use */
3153 for (job = G.job_list; job; job = job->next)
3154 if (job->jobid >= pi->jobid)
3155 pi->jobid = job->jobid + 1;
3157 /* Add job to the list of running jobs */
3159 while ((job = *jobp) != NULL)
3161 job = *jobp = xmalloc(sizeof(*job));
3163 *job = *pi; /* physical copy */
3165 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3166 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3167 for (i = 0; i < pi->num_cmds; i++) {
3168 job->cmds[i].pid = pi->cmds[i].pid;
3169 /* all other fields are not used and stay zero */
3171 job->cmdtext = xstrdup(get_cmdtext(pi));
3173 if (G_interactive_fd)
3174 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3175 /* Last command's pid goes to $! */
3176 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3177 G.last_jobid = job->jobid;
3180 static void remove_bg_job(struct pipe *pi)
3182 struct pipe *prev_pipe;
3184 if (pi == G.job_list) {
3185 G.job_list = pi->next;
3187 prev_pipe = G.job_list;
3188 while (prev_pipe->next != pi)
3189 prev_pipe = prev_pipe->next;
3190 prev_pipe->next = pi->next;
3193 G.last_jobid = G.job_list->jobid;
3198 /* Remove a backgrounded job */
3199 static void delete_finished_bg_job(struct pipe *pi)
3202 pi->stopped_cmds = 0;
3208 /* Check to see if any processes have exited -- if they
3209 * have, figure out why and see if a job has completed */
3210 static int checkjobs(struct pipe* fg_pipe)
3220 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3223 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3224 // /* avoid doing syscall, nothing there anyway */
3227 attributes = WUNTRACED;
3228 if (fg_pipe == NULL)
3229 attributes |= WNOHANG;
3231 /* Do we do this right?
3232 * bash-3.00# sleep 20 | false
3234 * [3]+ Stopped sleep 20 | false
3235 * bash-3.00# echo $?
3236 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3237 * [hush 1.14.0: yes we do it right]
3244 // i = G.count_SIGCHLD;
3245 childpid = waitpid(-1, &status, attributes);
3246 if (childpid <= 0) {
3247 if (childpid && errno != ECHILD)
3248 bb_perror_msg("waitpid");
3249 // else /* Until next SIGCHLD, waitpid's are useless */
3250 // G.handled_SIGCHLD = i;
3253 dead = WIFEXITED(status) || WIFSIGNALED(status);
3256 if (WIFSTOPPED(status))
3257 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3258 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3259 if (WIFSIGNALED(status))
3260 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3261 childpid, WTERMSIG(status), WEXITSTATUS(status));
3262 if (WIFEXITED(status))
3263 debug_printf_jobs("pid %d exited, exitcode %d\n",
3264 childpid, WEXITSTATUS(status));
3266 /* Were we asked to wait for fg pipe? */
3268 for (i = 0; i < fg_pipe->num_cmds; i++) {
3269 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3270 if (fg_pipe->cmds[i].pid != childpid)
3273 fg_pipe->cmds[i].pid = 0;
3274 fg_pipe->alive_cmds--;
3275 if (i == fg_pipe->num_cmds - 1) {
3276 /* last process gives overall exitstatus */
3277 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3278 rcode = WEXITSTATUS(status);
3279 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3280 /* bash prints killing signal's name for *last*
3281 * process in pipe (prints just newline for SIGINT).
3282 * Mimic this. Example: "sleep 5" + ^\
3284 if (WIFSIGNALED(status)) {
3285 int sig = WTERMSIG(status);
3286 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3290 fg_pipe->cmds[i].is_stopped = 1;
3291 fg_pipe->stopped_cmds++;
3293 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3294 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3295 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3296 /* All processes in fg pipe have exited or stopped */
3297 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3298 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3299 * and "killall -STOP cat" */
3300 if (G_interactive_fd) {
3302 if (fg_pipe->alive_cmds)
3303 insert_bg_job(fg_pipe);
3308 /* There are still running processes in the fg pipe */
3309 goto wait_more; /* do waitpid again */
3311 /* it wasnt fg_pipe, look for process in bg pipes */
3315 /* We asked to wait for bg or orphaned children */
3316 /* No need to remember exitcode in this case */
3317 for (pi = G.job_list; pi; pi = pi->next) {
3318 for (i = 0; i < pi->num_cmds; i++) {
3319 if (pi->cmds[i].pid == childpid)
3320 goto found_pi_and_prognum;
3323 /* Happens when shell is used as init process (init=/bin/sh) */
3324 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3325 continue; /* do waitpid again */
3327 found_pi_and_prognum:
3330 pi->cmds[i].pid = 0;
3332 if (!pi->alive_cmds) {
3333 if (G_interactive_fd)
3334 printf(JOB_STATUS_FORMAT, pi->jobid,
3335 "Done", pi->cmdtext);
3336 delete_finished_bg_job(pi);
3340 pi->cmds[i].is_stopped = 1;
3344 } /* while (waitpid succeeds)... */
3350 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3353 int rcode = checkjobs(fg_pipe);
3354 /* Job finished, move the shell to the foreground */
3355 p = getpgid(0); /* pgid of our process */
3356 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3357 tcsetpgrp(G_interactive_fd, p);
3362 /* Start all the jobs, but don't wait for anything to finish.
3365 * Return code is normally -1, when the caller has to wait for children
3366 * to finish to determine the exit status of the pipe. If the pipe
3367 * is a simple builtin command, however, the action is done by the
3368 * time run_pipe returns, and the exit code is provided as the
3371 * Returns -1 only if started some children. IOW: we have to
3372 * mask out retvals of builtins etc with 0xff!
3374 * The only case when we do not need to [v]fork is when the pipe
3375 * is single, non-backgrounded, non-subshell command. Examples:
3376 * cmd ; ... { list } ; ...
3377 * cmd && ... { list } && ...
3378 * cmd || ... { list } || ...
3379 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3380 * or (if SH_STANDALONE) an applet, and we can run the { list }
3381 * with run_list. If it isn't one of these, we fork and exec cmd.
3383 * Cases when we must fork:
3384 * non-single: cmd | cmd
3385 * backgrounded: cmd & { list } &
3386 * subshell: ( list ) [&]
3388 static int run_pipe(struct pipe *pi)
3390 static const char *const null_ptr = NULL;
3393 struct command *command;
3394 char **argv_expanded;
3397 /* it is not always needed, but we aim to smaller code */
3398 int squirrel[] = { -1, -1, -1 };
3401 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3404 IF_HUSH_JOB(pi->pgrp = -1;)
3405 pi->stopped_cmds = 0;
3406 command = &(pi->cmds[0]);
3407 argv_expanded = NULL;
3409 if (pi->num_cmds != 1
3410 || pi->followup == PIPE_BG
3411 || command->grp_type == GRP_SUBSHELL
3418 debug_printf_exec(": group:%p argv:'%s'\n",
3419 command->group, command->argv ? command->argv[0] : "NONE");
3421 if (command->group) {
3422 #if ENABLE_HUSH_FUNCTIONS
3423 if (command->grp_type == GRP_FUNCTION) {
3424 /* "executing" func () { list } */
3425 struct function *funcp;
3427 funcp = new_function(command->argv[0]);
3428 /* funcp->name is already set to argv[0] */
3429 funcp->body = command->group;
3431 funcp->body_as_string = command->group_as_string;
3432 command->group_as_string = NULL;
3434 command->group = NULL;
3435 command->argv[0] = NULL;
3436 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3437 funcp->parent_cmd = command;
3438 command->child_func = funcp;
3440 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3442 return EXIT_SUCCESS;
3446 debug_printf("non-subshell group\n");
3447 rcode = 1; /* exitcode if redir failed */
3448 if (setup_redirects(command, squirrel) == 0) {
3449 debug_printf_exec(": run_list\n");
3450 rcode = run_list(command->group) & 0xff;
3452 restore_redirects(squirrel);
3453 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3455 debug_printf_exec("run_pipe: return %d\n", rcode);
3459 argv = command->argv ? command->argv : (char **) &null_ptr;
3461 const struct built_in_command *x;
3462 #if ENABLE_HUSH_FUNCTIONS
3463 const struct function *funcp;
3467 char **new_env = NULL;
3468 char **old_env = NULL;
3470 if (argv[command->assignment_cnt] == NULL) {
3471 /* Assignments, but no command */
3472 /* Ensure redirects take effect. Try "a=t >file" */
3473 rcode = setup_redirects(command, squirrel);
3474 restore_redirects(squirrel);
3475 /* Set shell variables */
3477 p = expand_string_to_string(*argv);
3478 debug_printf_exec("set shell var:'%s'->'%s'\n",
3480 set_local_var(p, 0, 0);
3483 /* Do we need to flag set_local_var() errors?
3484 * "assignment to readonly var" and "putenv error"
3486 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3488 debug_printf_exec("run_pipe: return %d\n", rcode);
3492 /* Expand the rest into (possibly) many strings each */
3493 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3495 x = find_builtin(argv_expanded[0]);
3496 #if ENABLE_HUSH_FUNCTIONS
3499 funcp = find_function(argv_expanded[0]);
3503 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3504 debug_printf("exec with redirects only\n");
3505 rcode = setup_redirects(command, NULL);
3506 goto clean_up_and_ret1;
3509 /* setup_redirects acts on file descriptors, not FILEs.
3510 * This is perfect for work that comes after exec().
3511 * Is it really safe for inline use? Experimentally,
3512 * things seem to work. */
3513 rcode = setup_redirects(command, squirrel);
3515 new_env = expand_assignments(argv, command->assignment_cnt);
3516 old_env = putenv_all_and_save_old(new_env);
3518 debug_printf_exec(": builtin '%s' '%s'...\n",
3519 x->cmd, argv_expanded[1]);
3520 rcode = x->function(argv_expanded) & 0xff;
3523 #if ENABLE_HUSH_FUNCTIONS
3525 debug_printf_exec(": function '%s' '%s'...\n",
3526 funcp->name, argv_expanded[1]);
3527 rcode = run_function(funcp, argv_expanded) & 0xff;
3531 #if ENABLE_FEATURE_SH_STANDALONE
3534 restore_redirects(squirrel);
3535 free_strings_and_unsetenv(new_env, 1);
3536 putenv_all(old_env);
3537 /* Free the pointers, but the strings themselves
3538 * are in environ now, don't use free_strings! */
3541 free(argv_expanded);
3542 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3544 debug_printf_exec("run_pipe return %d\n", rcode);
3548 #if ENABLE_FEATURE_SH_STANDALONE
3549 i = find_applet_by_name(argv_expanded[0]);
3550 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3551 rcode = setup_redirects(command, squirrel);
3553 new_env = expand_assignments(argv, command->assignment_cnt);
3554 old_env = putenv_all_and_save_old(new_env);
3555 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3556 argv_expanded[0], argv_expanded[1]);
3557 rcode = run_nofork_applet(i, argv_expanded);
3559 goto clean_up_and_ret;
3562 /* It is neither builtin nor applet. We must fork. */
3566 /* NB: argv_expanded may already be created, and that
3567 * might include `cmd` runs! Do not rerun it! We *must*
3568 * use argv_expanded if it's non-NULL */
3570 /* Going to fork a child per each pipe member */
3574 for (i = 0; i < pi->num_cmds; i++) {
3575 struct fd_pair pipefds;
3577 volatile nommu_save_t nommu_save;
3578 nommu_save.new_env = NULL;
3579 nommu_save.old_env = NULL;
3580 nommu_save.argv = NULL;
3581 nommu_save.argv_from_re_execing = NULL;
3583 command = &(pi->cmds[i]);
3584 if (command->argv) {
3585 debug_printf_exec(": pipe member '%s' '%s'...\n",
3586 command->argv[0], command->argv[1]);
3588 debug_printf_exec(": pipe member with no argv\n");
3591 /* pipes are inserted between pairs of commands */
3594 if ((i + 1) < pi->num_cmds)
3595 xpiped_pair(pipefds);
3597 command->pid = BB_MMU ? fork() : vfork();
3598 if (!command->pid) { /* child */
3600 disable_restore_tty_pgrp_on_exit();
3602 /* Every child adds itself to new process group
3603 * with pgid == pid_of_first_child_in_pipe */
3604 if (G.run_list_level == 1 && G_interactive_fd) {
3607 if (pgrp < 0) /* true for 1st process only */
3609 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3610 /* We do it in *every* child, not just first,
3612 tcsetpgrp(G_interactive_fd, pgrp);
3616 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
3617 /* 1st cmd in backgrounded pipe
3618 * should have its stdin /dev/null'ed */
3620 if (open(bb_dev_null, O_RDONLY))
3621 xopen("/", O_RDONLY);
3623 xmove_fd(nextin, 0);
3625 xmove_fd(pipefds.wr, 1);
3628 /* Like bash, explicit redirects override pipes,
3629 * and the pipe fd is available for dup'ing. */
3630 if (setup_redirects(command, NULL))
3633 /* Restore default handlers just prior to exec */
3634 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3636 /* Stores to nommu_save list of env vars putenv'ed
3637 * (NOMMU, on MMU we don't need that) */
3638 /* cast away volatility... */
3639 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3640 /* pseudo_exec() does not return */
3643 /* parent or error */
3644 enable_restore_tty_pgrp_on_exit();
3646 /* Clean up after vforked child */
3647 free(nommu_save.argv);
3648 free(nommu_save.argv_from_re_execing);
3649 free_strings_and_unsetenv(nommu_save.new_env, 1);
3650 putenv_all(nommu_save.old_env);
3651 /* Free the pointers, but the strings themselves
3652 * are in environ now, don't use free_strings! */
3653 free(nommu_save.old_env);
3655 free(argv_expanded);
3656 argv_expanded = NULL;
3657 if (command->pid < 0) { /* [v]fork failed */
3658 /* Clearly indicate, was it fork or vfork */
3659 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3663 /* Second and next children need to know pid of first one */
3665 pi->pgrp = command->pid;
3671 if ((i + 1) < pi->num_cmds)
3673 /* Pass read (output) pipe end to next iteration */
3674 nextin = pipefds.rd;
3677 if (!pi->alive_cmds) {
3679 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3684 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3688 #ifndef debug_print_tree
3689 static void debug_print_tree(struct pipe *pi, int lvl)
3691 static const char *const PIPE[] = {
3697 static const char *RES[] = {
3698 [RES_NONE ] = "NONE" ,
3701 [RES_THEN ] = "THEN" ,
3702 [RES_ELIF ] = "ELIF" ,
3703 [RES_ELSE ] = "ELSE" ,
3706 #if ENABLE_HUSH_LOOPS
3707 [RES_FOR ] = "FOR" ,
3708 [RES_WHILE] = "WHILE",
3709 [RES_UNTIL] = "UNTIL",
3711 [RES_DONE ] = "DONE" ,
3713 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3716 #if ENABLE_HUSH_CASE
3717 [RES_CASE ] = "CASE" ,
3718 [RES_MATCH] = "MATCH",
3719 [RES_CASEI] = "CASEI",
3720 [RES_ESAC ] = "ESAC" ,
3722 [RES_XXXX ] = "XXXX" ,
3723 [RES_SNTX ] = "SNTX" ,
3725 static const char *const GRPTYPE[] = {
3728 #if ENABLE_HUSH_FUNCTIONS
3737 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3738 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3740 while (prn < pi->num_cmds) {
3741 struct command *command = &pi->cmds[prn];
3742 char **argv = command->argv;
3744 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3746 command->assignment_cnt);
3747 if (command->group) {
3748 fprintf(stderr, " group %s: (argv=%p)\n",
3749 GRPTYPE[command->grp_type],
3751 debug_print_tree(command->group, lvl+1);
3755 if (argv) while (*argv) {
3756 fprintf(stderr, " '%s'", *argv);
3759 fprintf(stderr, "\n");
3768 /* NB: called by pseudo_exec, and therefore must not modify any
3769 * global data until exec/_exit (we can be a child after vfork!) */
3770 static int run_list(struct pipe *pi)
3772 #if ENABLE_HUSH_CASE
3773 char *case_word = NULL;
3775 #if ENABLE_HUSH_LOOPS
3776 struct pipe *loop_top = NULL;
3777 char *for_varname = NULL;
3778 char **for_lcur = NULL;
3779 char **for_list = NULL;
3781 smallint last_followup;
3783 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3784 smalluint cond_code = 0;
3786 enum { cond_code = 0 };
3789 smallint rword; /* enum reserved_style */
3790 smallint last_rword; /* ditto */
3793 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3796 #if ENABLE_HUSH_LOOPS
3797 /* Check syntax for "for" */
3798 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3799 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3801 /* current word is FOR or IN (BOLD in comments below) */
3802 if (cpipe->next == NULL) {
3803 syntax_error("malformed for");
3805 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3808 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3809 if (cpipe->next->res_word == RES_DO)
3811 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3812 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3813 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3815 syntax_error("malformed for");
3817 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3823 /* Past this point, all code paths should jump to ret: label
3824 * in order to return, no direct "return" statements please.
3825 * This helps to ensure that no memory is leaked. */
3833 last_rword = RES_XXXX;
3835 last_followup = PIPE_SEQ;
3836 rcode = G.last_exitcode;
3838 /* Go through list of pipes, (maybe) executing them. */
3839 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3843 IF_HAS_KEYWORDS(rword = pi->res_word;)
3844 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3845 rword, cond_code, last_rword);
3846 #if ENABLE_HUSH_LOOPS
3847 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3848 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3850 /* start of a loop: remember where loop starts */
3855 /* Still in the same "if...", "then..." or "do..." branch? */
3856 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3857 if ((rcode == 0 && last_followup == PIPE_OR)
3858 || (rcode != 0 && last_followup == PIPE_AND)
3860 /* It is "<true> || CMD" or "<false> && CMD"
3861 * and we should not execute CMD */
3862 debug_printf_exec("skipped cmd because of || or &&\n");
3863 last_followup = pi->followup;
3867 last_followup = pi->followup;
3868 IF_HAS_KEYWORDS(last_rword = rword;)
3871 if (rword == RES_THEN) {
3872 /* if false; then ... fi has exitcode 0! */
3873 G.last_exitcode = rcode = EXIT_SUCCESS;
3874 /* "if <false> THEN cmd": skip cmd */
3878 if (rword == RES_ELSE || rword == RES_ELIF) {
3879 /* "if <true> then ... ELSE/ELIF cmd":
3880 * skip cmd and all following ones */
3885 #if ENABLE_HUSH_LOOPS
3886 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3888 /* first loop through for */
3890 static const char encoded_dollar_at[] ALIGN1 = {
3891 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3892 }; /* encoded representation of "$@" */
3893 static const char *const encoded_dollar_at_argv[] = {
3894 encoded_dollar_at, NULL
3895 }; /* argv list with one element: "$@" */
3898 vals = (char**)encoded_dollar_at_argv;
3899 if (pi->next->res_word == RES_IN) {
3900 /* if no variable values after "in" we skip "for" */
3901 if (!pi->next->cmds[0].argv) {
3902 G.last_exitcode = rcode = EXIT_SUCCESS;
3903 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3906 vals = pi->next->cmds[0].argv;
3907 } /* else: "for var; do..." -> assume "$@" list */
3908 /* create list of variable values */
3909 debug_print_strings("for_list made from", vals);
3910 for_list = expand_strvec_to_strvec(vals);
3911 for_lcur = for_list;
3912 debug_print_strings("for_list", for_list);
3913 for_varname = pi->cmds[0].argv[0];
3914 pi->cmds[0].argv[0] = NULL;
3916 free(pi->cmds[0].argv[0]);
3918 /* "for" loop is over, clean up */
3922 pi->cmds[0].argv[0] = for_varname;
3925 /* Insert next value from for_lcur */
3926 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3927 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3928 pi->cmds[0].assignment_cnt = 1;
3930 if (rword == RES_IN) {
3931 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3933 if (rword == RES_DONE) {
3934 continue; /* "done" has no cmds too */
3937 #if ENABLE_HUSH_CASE
3938 if (rword == RES_CASE) {
3939 case_word = expand_strvec_to_string(pi->cmds->argv);
3942 if (rword == RES_MATCH) {
3945 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3947 /* all prev words didn't match, does this one match? */
3948 argv = pi->cmds->argv;
3950 char *pattern = expand_string_to_string(*argv);
3951 /* TODO: which FNM_xxx flags to use? */
3952 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3954 if (cond_code == 0) { /* match! we will execute this branch */
3955 free(case_word); /* make future "word)" stop */
3963 if (rword == RES_CASEI) { /* inside of a case branch */
3965 continue; /* not matched yet, skip this pipe */
3968 /* Just pressing <enter> in shell should check for jobs.
3969 * OTOH, in non-interactive shell this is useless
3970 * and only leads to extra job checks */
3971 if (pi->num_cmds == 0) {
3972 if (G_interactive_fd)
3973 goto check_jobs_and_continue;
3977 /* After analyzing all keywords and conditions, we decided
3978 * to execute this pipe. NB: have to do checkjobs(NULL)
3979 * after run_pipe to collect any background children,
3980 * even if list execution is to be stopped. */
3981 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3984 #if ENABLE_HUSH_LOOPS
3985 G.flag_break_continue = 0;
3987 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3989 /* We ran a builtin, function, or group.
3990 * rcode is already known
3991 * and we don't need to wait for anything. */
3992 G.last_exitcode = rcode;
3993 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3994 check_and_run_traps(0);
3995 #if ENABLE_HUSH_LOOPS
3996 /* Was it "break" or "continue"? */
3997 if (G.flag_break_continue) {
3998 smallint fbc = G.flag_break_continue;
3999 /* We might fall into outer *loop*,
4000 * don't want to break it too */
4002 G.depth_break_continue--;
4003 if (G.depth_break_continue == 0)
4004 G.flag_break_continue = 0;
4005 /* else: e.g. "continue 2" should *break* once, *then* continue */
4006 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4007 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4008 goto check_jobs_and_break;
4009 /* "continue": simulate end of loop */
4014 #if ENABLE_HUSH_FUNCTIONS
4015 if (G.flag_return_in_progress == 1)
4016 goto check_jobs_and_break;
4018 } else if (pi->followup == PIPE_BG) {
4019 /* What does bash do with attempts to background builtins? */
4020 /* even bash 3.2 doesn't do that well with nested bg:
4021 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4022 * I'm NOT treating inner &'s as jobs */
4023 check_and_run_traps(0);
4025 if (G.run_list_level == 1)
4027 debug_printf_exec("insert_bg_job1\n");
4029 debug_printf_exec("insert_bg_job2\n");
4032 G.last_exitcode = rcode = EXIT_SUCCESS;
4033 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4036 if (G.run_list_level == 1 && G_interactive_fd) {
4037 /* Waits for completion, then fg's main shell */
4038 rcode = checkjobs_and_fg_shell(pi);
4039 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4040 check_and_run_traps(0);
4043 { /* This one just waits for completion */
4044 rcode = checkjobs(pi);
4045 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4046 check_and_run_traps(0);
4048 G.last_exitcode = rcode;
4052 /* Analyze how result affects subsequent commands */
4054 if (rword == RES_IF || rword == RES_ELIF)
4057 #if ENABLE_HUSH_LOOPS
4058 /* Beware of "while false; true; do ..."! */
4059 if (pi->next && pi->next->res_word == RES_DO) {
4060 if (rword == RES_WHILE) {
4062 /* "while false; do...done" - exitcode 0 */
4063 G.last_exitcode = rcode = EXIT_SUCCESS;
4064 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4065 goto check_jobs_and_break;
4068 if (rword == RES_UNTIL) {
4070 debug_printf_exec(": until expr is true: breaking\n");
4071 check_jobs_and_break:
4079 check_jobs_and_continue:
4086 #if ENABLE_HUSH_LOOPS
4091 #if ENABLE_HUSH_CASE
4095 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4099 /* Select which version we will use */
4100 static int run_and_free_list(struct pipe *pi)
4103 debug_printf_exec("run_and_free_list entered\n");
4105 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4106 rcode = run_list(pi);
4108 /* free_pipe_list has the side effect of clearing memory.
4109 * In the long run that function can be merged with run_list,
4110 * but doing that now would hobble the debugging effort. */
4112 debug_printf_exec("run_and_free_list return %d\n", rcode);
4117 static struct pipe *new_pipe(void)
4120 pi = xzalloc(sizeof(struct pipe));
4121 /*pi->followup = 0; - deliberately invalid value */
4122 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4126 /* Command (member of a pipe) is complete, or we start a new pipe
4127 * if ctx->command is NULL.
4128 * No errors possible here.
4130 static int done_command(struct parse_context *ctx)
4132 /* The command is really already in the pipe structure, so
4133 * advance the pipe counter and make a new, null command. */
4134 struct pipe *pi = ctx->pipe;
4135 struct command *command = ctx->command;
4138 if (IS_NULL_CMD(command)) {
4139 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4143 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4144 //debug_print_tree(ctx->list_head, 20);
4146 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4149 /* Only real trickiness here is that the uncommitted
4150 * command structure is not counted in pi->num_cmds. */
4151 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4152 ctx->command = command = &pi->cmds[pi->num_cmds];
4154 memset(command, 0, sizeof(*command));
4155 return pi->num_cmds; /* used only for 0/nonzero check */
4158 static void done_pipe(struct parse_context *ctx, pipe_style type)
4162 debug_printf_parse("done_pipe entered, followup %d\n", type);
4163 /* Close previous command */
4164 not_null = done_command(ctx);
4165 ctx->pipe->followup = type;
4167 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4168 ctx->ctx_inverted = 0;
4169 ctx->pipe->res_word = ctx->ctx_res_w;
4172 /* Without this check, even just <enter> on command line generates
4173 * tree of three NOPs (!). Which is harmless but annoying.
4174 * IOW: it is safe to do it unconditionally. */
4177 || ctx->ctx_res_w == RES_FI
4179 #if ENABLE_HUSH_LOOPS
4180 || ctx->ctx_res_w == RES_DONE
4181 || ctx->ctx_res_w == RES_FOR
4182 || ctx->ctx_res_w == RES_IN
4184 #if ENABLE_HUSH_CASE
4185 || ctx->ctx_res_w == RES_ESAC
4189 debug_printf_parse("done_pipe: adding new pipe: "
4190 "not_null:%d ctx->ctx_res_w:%d\n",
4191 not_null, ctx->ctx_res_w);
4193 ctx->pipe->next = new_p;
4195 /* RES_THEN, RES_DO etc are "sticky" -
4196 * they remain set for pipes inside if/while.
4197 * This is used to control execution.
4198 * RES_FOR and RES_IN are NOT sticky (needed to support
4199 * cases where variable or value happens to match a keyword):
4201 #if ENABLE_HUSH_LOOPS
4202 if (ctx->ctx_res_w == RES_FOR
4203 || ctx->ctx_res_w == RES_IN)
4204 ctx->ctx_res_w = RES_NONE;
4206 #if ENABLE_HUSH_CASE
4207 if (ctx->ctx_res_w == RES_MATCH)
4208 ctx->ctx_res_w = RES_CASEI;
4210 ctx->command = NULL; /* trick done_command below */
4211 /* Create the memory for command, roughly:
4212 * ctx->pipe->cmds = new struct command;
4213 * ctx->command = &ctx->pipe->cmds[0];
4216 //debug_print_tree(ctx->list_head, 10);
4218 debug_printf_parse("done_pipe return\n");
4221 static void initialize_context(struct parse_context *ctx)
4223 memset(ctx, 0, sizeof(*ctx));
4224 ctx->pipe = ctx->list_head = new_pipe();
4225 /* Create the memory for command, roughly:
4226 * ctx->pipe->cmds = new struct command;
4227 * ctx->command = &ctx->pipe->cmds[0];
4232 /* If a reserved word is found and processed, parse context is modified
4233 * and 1 is returned.
4236 struct reserved_combo {
4239 unsigned char assignment_flag;
4243 FLAG_END = (1 << RES_NONE ),
4245 FLAG_IF = (1 << RES_IF ),
4246 FLAG_THEN = (1 << RES_THEN ),
4247 FLAG_ELIF = (1 << RES_ELIF ),
4248 FLAG_ELSE = (1 << RES_ELSE ),
4249 FLAG_FI = (1 << RES_FI ),
4251 #if ENABLE_HUSH_LOOPS
4252 FLAG_FOR = (1 << RES_FOR ),
4253 FLAG_WHILE = (1 << RES_WHILE),
4254 FLAG_UNTIL = (1 << RES_UNTIL),
4255 FLAG_DO = (1 << RES_DO ),
4256 FLAG_DONE = (1 << RES_DONE ),
4257 FLAG_IN = (1 << RES_IN ),
4259 #if ENABLE_HUSH_CASE
4260 FLAG_MATCH = (1 << RES_MATCH),
4261 FLAG_ESAC = (1 << RES_ESAC ),
4263 FLAG_START = (1 << RES_XXXX ),
4266 static const struct reserved_combo* match_reserved_word(o_string *word)
4268 /* Mostly a list of accepted follow-up reserved words.
4269 * FLAG_END means we are done with the sequence, and are ready
4270 * to turn the compound list into a command.
4271 * FLAG_START means the word must start a new compound list.
4273 static const struct reserved_combo reserved_list[] = {
4275 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4276 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4277 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4278 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4279 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4280 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4282 #if ENABLE_HUSH_LOOPS
4283 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4284 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4285 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4286 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4287 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4288 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4290 #if ENABLE_HUSH_CASE
4291 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4292 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4295 const struct reserved_combo *r;
4297 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4298 if (strcmp(word->data, r->literal) == 0)
4303 /* Return 0: not a keyword, 1: keyword
4305 static int reserved_word(o_string *word, struct parse_context *ctx)
4307 #if ENABLE_HUSH_CASE
4308 static const struct reserved_combo reserved_match = {
4309 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4312 const struct reserved_combo *r;
4316 r = match_reserved_word(word);
4320 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4321 #if ENABLE_HUSH_CASE
4322 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4323 /* "case word IN ..." - IN part starts first match part */
4324 r = &reserved_match;
4327 if (r->flag == 0) { /* '!' */
4328 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4329 syntax_error("! ! command");
4330 ctx->ctx_res_w = RES_SNTX;
4332 ctx->ctx_inverted = 1;
4335 if (r->flag & FLAG_START) {
4336 struct parse_context *old;
4338 old = xmalloc(sizeof(*old));
4339 debug_printf_parse("push stack %p\n", old);
4340 *old = *ctx; /* physical copy */
4341 initialize_context(ctx);
4343 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4344 syntax_error_at(word->data);
4345 ctx->ctx_res_w = RES_SNTX;
4348 /* "{...} fi" is ok. "{...} if" is not
4350 * if { echo foo; } then { echo bar; } fi */
4351 if (ctx->command->group)
4352 done_pipe(ctx, PIPE_SEQ);
4355 ctx->ctx_res_w = r->res;
4356 ctx->old_flag = r->flag;
4357 word->o_assignment = r->assignment_flag;
4359 if (ctx->old_flag & FLAG_END) {
4360 struct parse_context *old;
4362 done_pipe(ctx, PIPE_SEQ);
4363 debug_printf_parse("pop stack %p\n", ctx->stack);
4365 old->command->group = ctx->list_head;
4366 old->command->grp_type = GRP_NORMAL;
4368 o_addstr(&old->as_string, ctx->as_string.data);
4369 o_free_unsafe(&ctx->as_string);
4370 old->command->group_as_string = xstrdup(old->as_string.data);
4371 debug_printf_parse("pop, remembering as:'%s'\n",
4372 old->command->group_as_string);
4374 *ctx = *old; /* physical copy */
4381 /* Word is complete, look at it and update parsing context.
4382 * Normal return is 0. Syntax errors return 1.
4383 * Note: on return, word is reset, but not o_free'd!
4385 static int done_word(o_string *word, struct parse_context *ctx)
4387 struct command *command = ctx->command;
4389 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4390 if (word->length == 0 && word->o_quoted == 0) {
4391 debug_printf_parse("done_word return 0: true null, ignored\n");
4395 if (ctx->pending_redirect) {
4396 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4397 * only if run as "bash", not "sh" */
4398 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4400 * ...the word that follows the redirection operator
4401 * shall be subjected to tilde expansion, parameter expansion,
4402 * command substitution, arithmetic expansion, and quote
4403 * removal. Pathname expansion shall not be performed
4404 * on the word by a non-interactive shell; an interactive
4405 * shell may perform it, but shall do so only when
4406 * the expansion would result in one word."
4408 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4409 /* Cater for >\file case:
4410 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4411 * Same with heredocs:
4412 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4414 unbackslash(ctx->pending_redirect->rd_filename);
4415 /* Is it <<"HEREDOC"? */
4416 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4419 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4421 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4422 ctx->pending_redirect = NULL;
4424 /* If this word wasn't an assignment, next ones definitely
4425 * can't be assignments. Even if they look like ones. */
4426 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4427 && word->o_assignment != WORD_IS_KEYWORD
4429 word->o_assignment = NOT_ASSIGNMENT;
4431 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4432 command->assignment_cnt++;
4433 word->o_assignment = MAYBE_ASSIGNMENT;
4437 # if ENABLE_HUSH_CASE
4438 if (ctx->ctx_dsemicolon
4439 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4441 /* already done when ctx_dsemicolon was set to 1: */
4442 /* ctx->ctx_res_w = RES_MATCH; */
4443 ctx->ctx_dsemicolon = 0;
4446 if (!command->argv /* if it's the first word... */
4447 # if ENABLE_HUSH_LOOPS
4448 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4449 && ctx->ctx_res_w != RES_IN
4452 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4453 if (reserved_word(word, ctx)) {
4454 o_reset_to_empty_unquoted(word);
4455 debug_printf_parse("done_word return %d\n",
4456 (ctx->ctx_res_w == RES_SNTX));
4457 return (ctx->ctx_res_w == RES_SNTX);
4461 if (command->group) {
4462 /* "{ echo foo; } echo bar" - bad */
4463 syntax_error_at(word->data);
4464 debug_printf_parse("done_word return 1: syntax error, "
4465 "groups and arglists don't mix\n");
4468 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4469 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4470 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4471 /* (otherwise it's known to be not empty and is already safe) */
4473 /* exclude "$@" - it can expand to no word despite "" */
4474 char *p = word->data;
4475 while (p[0] == SPECIAL_VAR_SYMBOL
4476 && (p[1] & 0x7f) == '@'
4477 && p[2] == SPECIAL_VAR_SYMBOL
4481 if (p == word->data || p[0] != '\0') {
4482 /* saw no "$@", or not only "$@" but some
4483 * real text is there too */
4484 /* insert "empty variable" reference, this makes
4485 * e.g. "", $empty"" etc to not disappear */
4486 o_addchr(word, SPECIAL_VAR_SYMBOL);
4487 o_addchr(word, SPECIAL_VAR_SYMBOL);
4490 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4491 debug_print_strings("word appended to argv", command->argv);
4494 #if ENABLE_HUSH_LOOPS
4495 if (ctx->ctx_res_w == RES_FOR) {
4497 || !is_well_formed_var_name(command->argv[0], '\0')
4499 /* bash says just "not a valid identifier" */
4500 syntax_error("not a valid identifier in for");
4503 /* Force FOR to have just one word (variable name) */
4504 /* NB: basically, this makes hush see "for v in ..."
4505 * syntax as if it is "for v; in ...". FOR and IN become
4506 * two pipe structs in parse tree. */
4507 done_pipe(ctx, PIPE_SEQ);
4510 #if ENABLE_HUSH_CASE
4511 /* Force CASE to have just one word */
4512 if (ctx->ctx_res_w == RES_CASE) {
4513 done_pipe(ctx, PIPE_SEQ);
4517 o_reset_to_empty_unquoted(word);
4519 debug_printf_parse("done_word return 0\n");
4524 /* Peek ahead in the input to find out if we have a "&n" construct,
4525 * as in "2>&1", that represents duplicating a file descriptor.
4527 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4528 * REDIRFD_SYNTAX_ERR if syntax error,
4529 * REDIRFD_TO_FILE if no & was seen,
4530 * or the number found.
4533 #define parse_redir_right_fd(as_string, input) \
4534 parse_redir_right_fd(input)
4536 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4542 return REDIRFD_TO_FILE;
4544 ch = i_getch(input); /* get the & */
4545 nommu_addchr(as_string, ch);
4548 ch = i_getch(input);
4549 nommu_addchr(as_string, ch);
4550 return REDIRFD_CLOSE;
4554 while (ch != EOF && isdigit(ch)) {
4555 d = d*10 + (ch-'0');
4557 ch = i_getch(input);
4558 nommu_addchr(as_string, ch);
4563 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4565 bb_error_msg("ambiguous redirect");
4566 return REDIRFD_SYNTAX_ERR;
4569 /* Return code is 0 normal, 1 if a syntax error is detected
4571 static int parse_redirect(struct parse_context *ctx,
4574 struct in_str *input)
4576 struct command *command = ctx->command;
4577 struct redir_struct *redir;
4578 struct redir_struct **redirp;
4581 dup_num = REDIRFD_TO_FILE;
4582 if (style != REDIRECT_HEREDOC) {
4583 /* Check for a '>&1' type redirect */
4584 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4585 if (dup_num == REDIRFD_SYNTAX_ERR)
4588 int ch = i_peek(input);
4589 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4590 if (dup_num) { /* <<-... */
4591 ch = i_getch(input);
4592 nommu_addchr(&ctx->as_string, ch);
4597 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4598 int ch = i_peek(input);
4600 /* >|FILE redirect ("clobbering" >).
4601 * Since we do not support "set -o noclobber" yet,
4602 * >| and > are the same for now. Just eat |.
4604 ch = i_getch(input);
4605 nommu_addchr(&ctx->as_string, ch);
4609 /* Create a new redir_struct and append it to the linked list */
4610 redirp = &command->redirects;
4611 while ((redir = *redirp) != NULL) {
4612 redirp = &(redir->next);
4614 *redirp = redir = xzalloc(sizeof(*redir));
4615 /* redir->next = NULL; */
4616 /* redir->rd_filename = NULL; */
4617 redir->rd_type = style;
4618 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4620 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4621 redir_table[style].descrip);
4623 redir->rd_dup = dup_num;
4624 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4625 /* Erik had a check here that the file descriptor in question
4626 * is legit; I postpone that to "run time"
4627 * A "-" representation of "close me" shows up as a -3 here */
4628 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4629 redir->rd_fd, redir->rd_dup);
4631 /* Set ctx->pending_redirect, so we know what to do at the
4632 * end of the next parsed word. */
4633 ctx->pending_redirect = redir;
4638 /* If a redirect is immediately preceded by a number, that number is
4639 * supposed to tell which file descriptor to redirect. This routine
4640 * looks for such preceding numbers. In an ideal world this routine
4641 * needs to handle all the following classes of redirects...
4642 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4643 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4644 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4645 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4647 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4649 * ... If n is quoted, the number shall not be recognized as part of
4650 * the redirection expression. For example:
4652 * writes the character 2 into file a"
4653 * We are getting it right by setting ->o_quoted on any \<char>
4655 * A -1 return means no valid number was found,
4656 * the caller should use the appropriate default for this redirection.
4658 static int redirect_opt_num(o_string *o)
4662 if (o->data == NULL)
4664 num = bb_strtou(o->data, NULL, 10);
4665 if (errno || num < 0)
4667 o_reset_to_empty_unquoted(o);
4672 #define fetch_till_str(as_string, input, word, skip_tabs) \
4673 fetch_till_str(input, word, skip_tabs)
4675 static char *fetch_till_str(o_string *as_string,
4676 struct in_str *input,
4680 o_string heredoc = NULL_O_STRING;
4686 ch = i_getch(input);
4687 nommu_addchr(as_string, ch);
4689 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4690 heredoc.data[past_EOL] = '\0';
4691 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4692 return heredoc.data;
4695 o_addchr(&heredoc, ch);
4696 past_EOL = heredoc.length;
4699 ch = i_getch(input);
4700 nommu_addchr(as_string, ch);
4701 } while (skip_tabs && ch == '\t');
4702 } while (ch == '\n');
4705 o_free_unsafe(&heredoc);
4708 o_addchr(&heredoc, ch);
4709 nommu_addchr(as_string, ch);
4713 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4714 * and load them all. There should be exactly heredoc_cnt of them.
4716 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4718 struct pipe *pi = ctx->list_head;
4720 while (pi && heredoc_cnt) {
4722 struct command *cmd = pi->cmds;
4724 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4726 cmd->argv ? cmd->argv[0] : "NONE");
4727 for (i = 0; i < pi->num_cmds; i++) {
4728 struct redir_struct *redir = cmd->redirects;
4730 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4731 i, cmd->argv ? cmd->argv[0] : "NONE");
4733 if (redir->rd_type == REDIRECT_HEREDOC) {
4736 redir->rd_type = REDIRECT_HEREDOC2;
4737 /* redir->dup is (ab)used to indicate <<- */
4738 p = fetch_till_str(&ctx->as_string, input,
4739 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4741 syntax_error("unexpected EOF in here document");
4744 free(redir->rd_filename);
4745 redir->rd_filename = p;
4748 redir = redir->next;
4755 /* Should be 0. If it isn't, it's a parse error */
4757 bb_error_msg_and_die("heredoc BUG 2");
4763 #if ENABLE_HUSH_TICK
4764 static FILE *generate_stream_from_string(const char *s)
4767 int pid, channel[2];
4773 pid = BB_MMU ? fork() : vfork();
4775 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4777 if (pid == 0) { /* child */
4778 disable_restore_tty_pgrp_on_exit();
4779 /* Process substitution is not considered to be usual
4780 * 'command execution'.
4781 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4788 close(channel[0]); /* NB: close _first_, then move fd! */
4789 xmove_fd(channel[1], 1);
4790 /* Prevent it from trying to handle ctrl-z etc */
4791 IF_HUSH_JOB(G.run_list_level = 1;)
4793 reset_traps_to_defaults();
4794 parse_and_run_string(s);
4795 _exit(G.last_exitcode);
4797 /* We re-execute after vfork on NOMMU. This makes this script safe:
4798 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4799 * huge=`cat BIG` # was blocking here forever
4802 re_execute_shell(&to_free,
4810 enable_restore_tty_pgrp_on_exit();
4815 pf = fdopen(channel[0], "r");
4819 /* Return code is exit status of the process that is run. */
4820 static int process_command_subs(o_string *dest, const char *s)
4823 struct in_str pipe_str;
4826 pf = generate_stream_from_string(s);
4829 close_on_exec_on(fileno(pf));
4831 /* Now send results of command back into original context */
4832 setup_file_in_str(&pipe_str, pf);
4834 while ((ch = i_getch(&pipe_str)) != EOF) {
4840 o_addchr(dest, '\n');
4843 o_addQchr(dest, ch);
4846 debug_printf("done reading from pipe, pclose()ing\n");
4847 /* Note: we got EOF, and we just close the read end of the pipe.
4848 * We do not wait for the `cmd` child to terminate. bash and ash do.
4850 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4851 * `false`; echo $? - bash outputs "1"
4854 debug_printf("closed FILE from child. return 0\n");
4859 static int parse_group(o_string *dest, struct parse_context *ctx,
4860 struct in_str *input, int ch)
4862 /* dest contains characters seen prior to ( or {.
4863 * Typically it's empty, but for function defs,
4864 * it contains function name (without '()'). */
4865 struct pipe *pipe_list;
4867 struct command *command = ctx->command;
4869 debug_printf_parse("parse_group entered\n");
4870 #if ENABLE_HUSH_FUNCTIONS
4871 if (ch == '(' && !dest->o_quoted) {
4873 if (done_word(dest, ctx))
4876 goto skip; /* (... */
4877 if (command->argv[1]) { /* word word ... (... */
4878 syntax_error_unexpected_ch('(');
4881 /* it is "word(..." or "word (..." */
4883 ch = i_getch(input);
4884 while (ch == ' ' || ch == '\t');
4886 syntax_error_unexpected_ch(ch);
4889 nommu_addchr(&ctx->as_string, ch);
4891 ch = i_getch(input);
4892 while (ch == ' ' || ch == '\t' || ch == '\n');
4894 syntax_error_unexpected_ch(ch);
4897 nommu_addchr(&ctx->as_string, ch);
4898 command->grp_type = GRP_FUNCTION;
4902 if (command->argv /* word [word]{... */
4903 || dest->length /* word{... */
4904 || dest->o_quoted /* ""{... */
4907 debug_printf_parse("parse_group return 1: "
4908 "syntax error, groups and arglists don't mix\n");
4912 #if ENABLE_HUSH_FUNCTIONS
4918 command->grp_type = GRP_SUBSHELL;
4920 /* bash does not allow "{echo...", requires whitespace */
4921 ch = i_getch(input);
4922 if (ch != ' ' && ch != '\t' && ch != '\n') {
4923 syntax_error_unexpected_ch(ch);
4926 nommu_addchr(&ctx->as_string, ch);
4931 char *as_string = NULL;
4933 pipe_list = parse_stream(&as_string, input, endch);
4936 o_addstr(&ctx->as_string, as_string);
4938 /* empty ()/{} or parse error? */
4939 if (!pipe_list || pipe_list == ERR_PTR) {
4940 /* parse_stream already emitted error msg */
4944 debug_printf_parse("parse_group return 1: "
4945 "parse_stream returned %p\n", pipe_list);
4948 command->group = pipe_list;
4950 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4951 command->group_as_string = as_string;
4952 debug_printf_parse("end of group, remembering as:'%s'\n",
4953 command->group_as_string);
4956 debug_printf_parse("parse_group return 0\n");
4958 /* command remains "open", available for possible redirects */
4961 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4962 /* Subroutines for copying $(...) and `...` things */
4963 static void add_till_backquote(o_string *dest, struct in_str *input);
4965 static void add_till_single_quote(o_string *dest, struct in_str *input)
4968 int ch = i_getch(input);
4970 syntax_error_unterm_ch('\'');
4971 /*xfunc_die(); - redundant */
4978 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4979 static void add_till_double_quote(o_string *dest, struct in_str *input)
4982 int ch = i_getch(input);
4984 syntax_error_unterm_ch('"');
4985 /*xfunc_die(); - redundant */
4989 if (ch == '\\') { /* \x. Copy both chars. */
4991 ch = i_getch(input);
4995 add_till_backquote(dest, input);
4999 //if (ch == '$') ...
5002 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5004 * "Within the backquoted style of command substitution, backslash
5005 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5006 * The search for the matching backquote shall be satisfied by the first
5007 * backquote found without a preceding backslash; during this search,
5008 * if a non-escaped backquote is encountered within a shell comment,
5009 * a here-document, an embedded command substitution of the $(command)
5010 * form, or a quoted string, undefined results occur. A single-quoted
5011 * or double-quoted string that begins, but does not end, within the
5012 * "`...`" sequence produces undefined results."
5014 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5016 static void add_till_backquote(o_string *dest, struct in_str *input)
5019 int ch = i_getch(input);
5021 syntax_error_unterm_ch('`');
5022 /*xfunc_die(); - redundant */
5027 /* \x. Copy both chars unless it is \` */
5028 int ch2 = i_getch(input);
5030 syntax_error_unterm_ch('`');
5031 /*xfunc_die(); - redundant */
5033 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5040 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5041 * quoting and nested ()s.
5042 * "With the $(command) style of command substitution, all characters
5043 * following the open parenthesis to the matching closing parenthesis
5044 * constitute the command. Any valid shell script can be used for command,
5045 * except a script consisting solely of redirections which produces
5046 * unspecified results."
5048 * echo $(echo '(TEST)' BEST) (TEST) BEST
5049 * echo $(echo 'TEST)' BEST) TEST) BEST
5050 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5052 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5056 int ch = i_getch(input);
5058 syntax_error_unterm_ch(')');
5059 /*xfunc_die(); - redundant */
5067 if (i_peek(input) == ')') {
5075 add_till_single_quote(dest, input);
5080 add_till_double_quote(dest, input);
5085 /* \x. Copy verbatim. Important for \(, \) */
5086 ch = i_getch(input);
5088 syntax_error_unterm_ch(')');
5089 /*xfunc_die(); - redundant */
5096 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5098 /* Return code: 0 for OK, 1 for syntax error */
5100 #define handle_dollar(as_string, dest, input) \
5101 handle_dollar(dest, input)
5103 static int handle_dollar(o_string *as_string,
5105 struct in_str *input)
5108 int ch = i_peek(input); /* first character after the $ */
5109 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5111 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5113 ch = i_getch(input);
5114 nommu_addchr(as_string, ch);
5116 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5118 debug_printf_parse(": '%c'\n", ch);
5119 o_addchr(dest, ch | quote_mask);
5122 if (!isalnum(ch) && ch != '_')
5124 ch = i_getch(input);
5125 nommu_addchr(as_string, ch);
5127 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5128 } else if (isdigit(ch)) {
5130 ch = i_getch(input);
5131 nommu_addchr(as_string, ch);
5132 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5133 debug_printf_parse(": '%c'\n", ch);
5134 o_addchr(dest, ch | quote_mask);
5135 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5136 } else switch (ch) {
5138 case '!': /* last bg pid */
5139 case '?': /* last exit code */
5140 case '#': /* number of args */
5141 case '*': /* args */
5142 case '@': /* args */
5143 goto make_one_char_var;
5145 bool first_char, all_digits;
5147 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5148 ch = i_getch(input);
5149 nommu_addchr(as_string, ch);
5150 /* TODO: maybe someone will try to escape the '}' */
5155 ch = i_getch(input);
5156 nommu_addchr(as_string, ch);
5163 /* ${#var}: length of var contents */
5173 && ( (all_digits && !isdigit(ch))
5174 || (!all_digits && !isalnum(ch) && ch != '_')
5177 /* handle parameter expansions
5178 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5183 case ':': /* null modifier */
5184 if (expansion == 0) {
5185 debug_printf_parse(": null modifier\n");
5190 case '#': /* remove prefix */
5191 case '%': /* remove suffix */
5192 if (expansion == 0) {
5193 debug_printf_parse(": remove suffix/prefix\n");
5198 case '-': /* default value */
5199 case '=': /* assign default */
5200 case '+': /* alternative */
5201 case '?': /* error indicate */
5202 debug_printf_parse(": parameter expansion\n");
5207 syntax_error_unterm_str("${name}");
5208 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5213 debug_printf_parse(": '%c'\n", ch);
5214 o_addchr(dest, ch | quote_mask);
5218 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5221 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5226 ch = i_getch(input);
5227 nommu_addchr(as_string, ch);
5228 # if ENABLE_SH_MATH_SUPPORT
5229 if (i_peek(input) == '(') {
5230 ch = i_getch(input);
5231 nommu_addchr(as_string, ch);
5232 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5233 o_addchr(dest, /*quote_mask |*/ '+');
5237 add_till_closing_paren(dest, input, true);
5240 o_addstr(as_string, dest->data + pos);
5241 o_addchr(as_string, ')');
5242 o_addchr(as_string, ')');
5245 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5249 # if ENABLE_HUSH_TICK
5250 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5251 o_addchr(dest, quote_mask | '`');
5255 add_till_closing_paren(dest, input, false);
5258 o_addstr(as_string, dest->data + pos);
5259 o_addchr(as_string, '`');
5262 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5268 ch = i_getch(input);
5269 nommu_addchr(as_string, ch);
5271 if (isalnum(ch)) { /* it's $_name or $_123 */
5277 /* $_ Shell or shell script name; or last cmd name */
5278 /* $- Option flags set by set builtin or shell options (-i etc) */
5280 o_addQchr(dest, '$');
5282 debug_printf_parse("handle_dollar return 0\n");
5287 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5288 parse_stream_dquoted(dest, input, dquote_end)
5290 static int parse_stream_dquoted(o_string *as_string,
5292 struct in_str *input,
5299 ch = i_getch(input);
5301 nommu_addchr(as_string, ch);
5302 if (ch == dquote_end) { /* may be only '"' or EOF */
5303 if (dest->o_assignment == NOT_ASSIGNMENT)
5304 dest->o_escape ^= 1;
5305 debug_printf_parse("parse_stream_dquoted return 0\n");
5308 /* note: can't move it above ch == dquote_end check! */
5310 syntax_error_unterm_ch('"');
5311 /*xfunc_die(); - redundant */
5315 next = i_peek(input);
5317 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5318 ch, ch, dest->o_escape);
5321 syntax_error("\\<eof>");
5325 * "The backslash retains its special meaning [in "..."]
5326 * only when followed by one of the following characters:
5327 * $, `, ", \, or <newline>. A double quote may be quoted
5328 * within double quotes by preceding it with a backslash.
5330 if (strchr("$`\"\\", next) != NULL) {
5331 o_addqchr(dest, i_getch(input));
5333 o_addqchr(dest, '\\');
5338 if (handle_dollar(as_string, dest, input) != 0) {
5339 debug_printf_parse("parse_stream_dquoted return 1: "
5340 "handle_dollar returned non-0\n");
5345 #if ENABLE_HUSH_TICK
5347 //int pos = dest->length;
5348 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5349 o_addchr(dest, 0x80 | '`');
5350 add_till_backquote(dest, input);
5351 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5352 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5356 o_addQchr(dest, ch);
5358 && (dest->o_assignment == MAYBE_ASSIGNMENT
5359 || dest->o_assignment == WORD_IS_KEYWORD)
5360 && is_well_formed_var_name(dest->data, '=')
5362 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5368 * Scan input until EOF or end_trigger char.
5369 * Return a list of pipes to execute, or NULL on EOF
5370 * or if end_trigger character is met.
5371 * On syntax error, exit is shell is not interactive,
5372 * reset parsing machinery and start parsing anew,
5373 * or return ERR_PTR.
5375 static struct pipe *parse_stream(char **pstring,
5376 struct in_str *input,
5379 struct parse_context ctx;
5380 o_string dest = NULL_O_STRING;
5384 /* Double-quote state is handled in the state variable is_in_dquote.
5385 * A single-quote triggers a bypass of the main loop until its mate is
5386 * found. When recursing, quote state is passed in via dest->o_escape.
5388 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5389 end_trigger ? : 'X');
5392 G.ifs = get_local_var_value("IFS");
5397 #if ENABLE_HUSH_INTERACTIVE
5398 input->promptmode = 0; /* PS1 */
5400 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5401 initialize_context(&ctx);
5406 const char *is_special;
5410 redir_type redir_style;
5413 /* dest.o_quoted = 1; - already is (see below) */
5414 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5417 /* We reached closing '"' */
5420 ch = i_getch(input);
5421 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5422 ch, ch, dest.o_escape);
5427 syntax_error_unterm_str("here document");
5430 if (done_word(&dest, &ctx)) {
5434 done_pipe(&ctx, PIPE_SEQ);
5436 /* If we got nothing... */
5437 /* (this makes bare "&" cmd a no-op.
5438 * bash says: "syntax error near unexpected token '&'") */
5439 if (pi->num_cmds == 0
5440 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5446 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5448 *pstring = ctx.as_string.data;
5450 o_free_unsafe(&ctx.as_string);
5453 debug_printf_parse("parse_stream return %p\n", pi);
5456 nommu_addchr(&ctx.as_string, ch);
5457 is_ifs = strchr(G.ifs, ch);
5458 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5459 "\\$\"" IF_HUSH_TICK("`") /* always special */
5462 if (!is_special && !is_ifs) { /* ordinary char */
5464 o_addQchr(&dest, ch);
5465 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5466 || dest.o_assignment == WORD_IS_KEYWORD)
5468 && is_well_formed_var_name(dest.data, '=')
5470 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5476 if (done_word(&dest, &ctx)) {
5480 #if ENABLE_HUSH_CASE
5481 /* "case ... in <newline> word) ..." -
5482 * newlines are ignored (but ';' wouldn't be) */
5483 if (ctx.command->argv == NULL
5484 && ctx.ctx_res_w == RES_MATCH
5489 /* Treat newline as a command separator. */
5490 done_pipe(&ctx, PIPE_SEQ);
5491 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5493 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5498 dest.o_assignment = MAYBE_ASSIGNMENT;
5500 /* note: if (is_ifs) continue;
5501 * will still trigger for us */
5505 /* "cmd}" or "cmd }..." without semicolon or &:
5506 * } is an ordinary char in this case, even inside { cmd; }
5507 * Pathological example: { ""}; } should exec "}" cmd
5510 if (!IS_NULL_CMD(ctx.command) /* cmd } */
5511 || dest.length != 0 /* word} */
5512 || dest.o_quoted /* ""} */
5516 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5517 goto skip_end_trigger;
5518 /* else: } does terminate a group */
5521 if (end_trigger && end_trigger == ch
5522 && (heredoc_cnt == 0 || end_trigger != ';')
5525 /* This is technically valid:
5526 * { cat <<HERE; }; echo Ok
5530 * but we don't support this.
5531 * We require heredoc to be in enclosing {}/(),
5534 syntax_error_unterm_str("here document");
5537 if (done_word(&dest, &ctx)) {
5540 done_pipe(&ctx, PIPE_SEQ);
5541 dest.o_assignment = MAYBE_ASSIGNMENT;
5542 /* Do we sit outside of any if's, loops or case's? */
5544 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5548 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5550 *pstring = ctx.as_string.data;
5552 o_free_unsafe(&ctx.as_string);
5555 debug_printf_parse("parse_stream return %p: "
5556 "end_trigger char found\n",
5558 return ctx.list_head;
5567 next = i_peek(input);
5570 /* Catch <, > before deciding whether this word is
5571 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5574 redir_fd = redirect_opt_num(&dest);
5575 if (done_word(&dest, &ctx)) {
5578 redir_style = REDIRECT_OVERWRITE;
5580 redir_style = REDIRECT_APPEND;
5581 ch = i_getch(input);
5582 nommu_addchr(&ctx.as_string, ch);
5585 else if (next == '(') {
5586 syntax_error(">(process) not supported");
5590 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5592 continue; /* back to top of while (1) */
5594 redir_fd = redirect_opt_num(&dest);
5595 if (done_word(&dest, &ctx)) {
5598 redir_style = REDIRECT_INPUT;
5600 redir_style = REDIRECT_HEREDOC;
5602 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5603 ch = i_getch(input);
5604 nommu_addchr(&ctx.as_string, ch);
5605 } else if (next == '>') {
5606 redir_style = REDIRECT_IO;
5607 ch = i_getch(input);
5608 nommu_addchr(&ctx.as_string, ch);
5611 else if (next == '(') {
5612 syntax_error("<(process) not supported");
5616 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5618 continue; /* back to top of while (1) */
5621 if (dest.o_assignment == MAYBE_ASSIGNMENT
5622 /* check that we are not in word in "a=1 2>word b=1": */
5623 && !ctx.pending_redirect
5625 /* ch is a special char and thus this word
5626 * cannot be an assignment */
5627 dest.o_assignment = NOT_ASSIGNMENT;
5632 if (dest.length == 0) {
5635 if (ch == EOF || ch == '\n')
5638 /* note: we do not add it to &ctx.as_string */
5640 nommu_addchr(&ctx.as_string, '\n');
5642 o_addQchr(&dest, ch);
5647 syntax_error("\\<eof>");
5650 o_addchr(&dest, '\\');
5651 ch = i_getch(input);
5652 nommu_addchr(&ctx.as_string, ch);
5653 o_addchr(&dest, ch);
5654 /* Example: echo Hello \2>file
5655 * we need to know that word 2 is quoted */
5659 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5660 debug_printf_parse("parse_stream parse error: "
5661 "handle_dollar returned non-0\n");
5668 ch = i_getch(input);
5670 syntax_error_unterm_ch('\'');
5671 /*xfunc_die(); - redundant */
5673 nommu_addchr(&ctx.as_string, ch);
5676 if (dest.o_assignment == NOT_ASSIGNMENT)
5677 o_addqchr(&dest, ch);
5679 o_addchr(&dest, ch);
5684 is_in_dquote ^= 1; /* invert */
5685 if (dest.o_assignment == NOT_ASSIGNMENT)
5688 #if ENABLE_HUSH_TICK
5693 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5694 o_addchr(&dest, '`');
5698 add_till_backquote(&dest, input);
5700 o_addstr(&ctx.as_string, dest.data + pos);
5701 o_addchr(&ctx.as_string, '`');
5703 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5704 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5709 #if ENABLE_HUSH_CASE
5712 if (done_word(&dest, &ctx)) {
5715 done_pipe(&ctx, PIPE_SEQ);
5716 #if ENABLE_HUSH_CASE
5717 /* Eat multiple semicolons, detect
5718 * whether it means something special */
5723 ch = i_getch(input);
5724 nommu_addchr(&ctx.as_string, ch);
5725 if (ctx.ctx_res_w == RES_CASEI) {
5726 ctx.ctx_dsemicolon = 1;
5727 ctx.ctx_res_w = RES_MATCH;
5733 /* We just finished a cmd. New one may start
5734 * with an assignment */
5735 dest.o_assignment = MAYBE_ASSIGNMENT;
5738 if (done_word(&dest, &ctx)) {
5742 ch = i_getch(input);
5743 nommu_addchr(&ctx.as_string, ch);
5744 done_pipe(&ctx, PIPE_AND);
5746 done_pipe(&ctx, PIPE_BG);
5750 if (done_word(&dest, &ctx)) {
5753 #if ENABLE_HUSH_CASE
5754 if (ctx.ctx_res_w == RES_MATCH)
5755 break; /* we are in case's "word | word)" */
5757 if (next == '|') { /* || */
5758 ch = i_getch(input);
5759 nommu_addchr(&ctx.as_string, ch);
5760 done_pipe(&ctx, PIPE_OR);
5762 /* we could pick up a file descriptor choice here
5763 * with redirect_opt_num(), but bash doesn't do it.
5764 * "echo foo 2| cat" yields "foo 2". */
5769 #if ENABLE_HUSH_CASE
5770 /* "case... in [(]word)..." - skip '(' */
5771 if (ctx.ctx_res_w == RES_MATCH
5772 && ctx.command->argv == NULL /* not (word|(... */
5773 && dest.length == 0 /* not word(... */
5774 && dest.o_quoted == 0 /* not ""(... */
5780 if (parse_group(&dest, &ctx, input, ch) != 0) {
5785 #if ENABLE_HUSH_CASE
5786 if (ctx.ctx_res_w == RES_MATCH)
5790 /* proper use of this character is caught by end_trigger:
5791 * if we see {, we call parse_group(..., end_trigger='}')
5792 * and it will match } earlier (not here). */
5793 syntax_error_unexpected_ch(ch);
5797 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5803 struct parse_context *pctx;
5804 IF_HAS_KEYWORDS(struct parse_context *p2;)
5806 /* Clean up allocated tree.
5807 * Samples for finding leaks on syntax error recovery path.
5808 * Run them from interactive shell, watch pmap `pidof hush`.
5809 * while if false; then false; fi do break; done
5811 * while if false; then false; fi; do break; fi
5812 * Samples to catch leaks at execution:
5813 * while if (true | {true;}); then echo ok; fi; do break; done
5814 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5818 /* Update pipe/command counts,
5819 * otherwise freeing may miss some */
5820 done_pipe(pctx, PIPE_SEQ);
5821 debug_printf_clean("freeing list %p from ctx %p\n",
5822 pctx->list_head, pctx);
5823 debug_print_tree(pctx->list_head, 0);
5824 free_pipe_list(pctx->list_head);
5825 debug_printf_clean("freed list %p\n", pctx->list_head);
5827 o_free_unsafe(&pctx->as_string);
5829 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5833 IF_HAS_KEYWORDS(pctx = p2;)
5834 } while (HAS_KEYWORDS && pctx);
5835 /* Free text, clear all dest fields */
5837 /* If we are not in top-level parse, we return,
5838 * our caller will propagate error.
5840 if (end_trigger != ';') {
5848 /* Discard cached input, force prompt */
5850 IF_HUSH_INTERACTIVE(input->promptme = 1;)
5855 /* Executing from string: eval, sh -c '...'
5856 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5857 * end_trigger controls how often we stop parsing
5858 * NUL: parse all, execute, return
5859 * ';': parse till ';' or newline, execute, repeat till EOF
5861 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5864 struct pipe *pipe_list;
5866 pipe_list = parse_stream(NULL, inp, end_trigger);
5867 if (!pipe_list) /* EOF */
5869 debug_print_tree(pipe_list, 0);
5870 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5871 run_and_free_list(pipe_list);
5875 static void parse_and_run_string(const char *s)
5877 struct in_str input;
5878 setup_string_in_str(&input, s);
5879 parse_and_run_stream(&input, '\0');
5882 static void parse_and_run_file(FILE *f)
5884 struct in_str input;
5885 setup_file_in_str(&input, f);
5886 parse_and_run_stream(&input, ';');
5889 /* Called a few times only (or even once if "sh -c") */
5890 static void block_signals(int second_time)
5895 mask = (1 << SIGQUIT);
5896 if (G_interactive_fd)
5897 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
5898 G.non_DFL_mask = mask;
5901 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5905 sigaddset(&G.blocked_set, sig);
5909 sigdelset(&G.blocked_set, SIGCHLD);
5911 sigprocmask(SIG_SETMASK, &G.blocked_set,
5912 second_time ? NULL : &G.inherited_set);
5913 /* POSIX allows shell to re-enable SIGCHLD
5914 * even if it was SIG_IGN on entry */
5915 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5917 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5922 static void maybe_set_to_sigexit(int sig)
5924 void (*handler)(int);
5925 /* non_DFL_mask'ed signals are, well, masked,
5926 * no need to set handler for them.
5928 if (!((G.non_DFL_mask >> sig) & 1)) {
5929 handler = signal(sig, sigexit);
5930 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5931 signal(sig, handler);
5934 /* Set handlers to restore tty pgrp and exit */
5935 static void set_fatal_handlers(void)
5937 /* We _must_ restore tty pgrp on fatal signals */
5939 maybe_set_to_sigexit(SIGILL );
5940 maybe_set_to_sigexit(SIGFPE );
5941 maybe_set_to_sigexit(SIGBUS );
5942 maybe_set_to_sigexit(SIGSEGV);
5943 maybe_set_to_sigexit(SIGTRAP);
5944 } /* else: hush is perfect. what SEGV? */
5945 maybe_set_to_sigexit(SIGABRT);
5946 /* bash 3.2 seems to handle these just like 'fatal' ones */
5947 maybe_set_to_sigexit(SIGPIPE);
5948 maybe_set_to_sigexit(SIGALRM);
5949 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
5950 * if we aren't interactive... but in this case
5951 * we never want to restore pgrp on exit, and this fn is not called */
5952 /*maybe_set_to_sigexit(SIGHUP );*/
5953 /*maybe_set_to_sigexit(SIGTERM);*/
5954 /*maybe_set_to_sigexit(SIGINT );*/
5958 static int set_mode(const char cstate, const char mode)
5960 int state = (cstate == '-' ? 1 : 0);
5962 case 'n': G.fake_mode = state; break;
5963 case 'x': /*G.debug_mode = state;*/ break;
5964 default: return EXIT_FAILURE;
5966 return EXIT_SUCCESS;
5969 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5970 int hush_main(int argc, char **argv)
5972 static const struct variable const_shell_ver = {
5974 .varstr = (char*)hush_version_str,
5975 .max_len = 1, /* 0 can provoke free(name) */
5979 int signal_mask_is_inited = 0;
5982 struct variable *cur_var;
5985 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5986 G.last_exitcode = EXIT_SUCCESS;
5988 G.argv0_for_re_execing = argv[0];
5990 /* Deal with HUSH_VERSION */
5991 G.shell_ver = const_shell_ver; /* copying struct here */
5992 G.top_var = &G.shell_ver;
5993 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5994 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5995 /* Initialize our shell local variables with the values
5996 * currently living in the environment */
5997 cur_var = G.top_var;
6000 char *value = strchr(*e, '=');
6001 if (value) { /* paranoia */
6002 cur_var->next = xzalloc(sizeof(*cur_var));
6003 cur_var = cur_var->next;
6004 cur_var->varstr = *e;
6005 cur_var->max_len = strlen(*e);
6006 cur_var->flg_export = 1;
6010 debug_printf_env("putenv '%s'\n", hush_version_str);
6011 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
6012 #if ENABLE_FEATURE_EDITING
6013 G.line_input_state = new_line_input_t(FOR_SHELL);
6015 G.global_argc = argc;
6016 G.global_argv = argv;
6017 /* Initialize some more globals to non-zero values */
6019 cmdedit_update_prompt();
6021 if (setjmp(die_jmp)) {
6022 /* xfunc has failed! die die die */
6023 /* no EXIT traps, this is an escape hatch! */
6025 hush_exit(xfunc_error_retval);
6028 /* Shell is non-interactive at first. We need to call
6029 * block_signals(0) if we are going to execute "sh <script>",
6030 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6031 * If we later decide that we are interactive, we run block_signals(0)
6032 * (or re-run block_signals(1) if we ran block_signals(0) before)
6033 * in order to intercept (more) signals.
6037 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6039 opt = getopt(argc, argv, "c:xins"
6042 # if ENABLE_HUSH_FUNCTIONS
6052 G.root_pid = getpid();
6053 G.global_argv = argv + optind;
6054 if (!argv[optind]) {
6055 /* -c 'script' (no params): prevent empty $0 */
6056 *--G.global_argv = argv[0];
6058 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
6059 G.global_argc = argc - optind;
6060 block_signals(0); /* 0: called 1st time */
6061 parse_and_run_string(optarg);
6064 /* Well, we cannot just declare interactiveness,
6065 * we have to have some stuff (ctty, etc) */
6066 /* G_interactive_fd++; */
6069 /* "-s" means "read from stdin", but this is how we always
6070 * operate, so simply do nothing here. */
6073 case '<': /* "big heredoc" support */
6074 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6077 G.root_pid = bb_strtou(optarg, &optarg, 16);
6079 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6081 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6082 # if ENABLE_HUSH_LOOPS
6084 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6089 set_local_var(xstrdup(optarg), 0, opt == 'R');
6091 # if ENABLE_HUSH_FUNCTIONS
6093 struct function *funcp = new_function(optarg);
6094 /* funcp->name is already set to optarg */
6095 /* funcp->body is set to NULL. It's a special case. */
6096 funcp->body_as_string = argv[optind];
6104 if (!set_mode('-', opt))
6108 fprintf(stderr, "Usage: sh [FILE]...\n"
6109 " or: sh -c command [args]...\n\n");
6115 } /* option parsing loop */
6118 G.root_pid = getpid();
6120 /* If we are login shell... */
6121 if (argv[0] && argv[0][0] == '-') {
6123 /* TODO: what should argv be while sourcing /etc/profile? */
6124 debug_printf("sourcing /etc/profile\n");
6125 input = fopen_for_read("/etc/profile");
6126 if (input != NULL) {
6127 close_on_exec_on(fileno(input));
6128 block_signals(0); /* 0: called 1st time */
6129 signal_mask_is_inited = 1;
6130 parse_and_run_file(input);
6133 /* bash: after sourcing /etc/profile,
6134 * tries to source (in the given order):
6135 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6136 * stopping of first found. --noprofile turns this off.
6137 * bash also sources ~/.bash_logout on exit.
6138 * If called as sh, skips .bash_XXX files.
6145 * "bash <script>" (which is never interactive (unless -i?))
6146 * sources $BASH_ENV here (without scanning $PATH).
6147 * If called as sh, does the same but with $ENV.
6149 debug_printf("running script '%s'\n", argv[optind]);
6150 G.global_argv = argv + optind;
6151 G.global_argc = argc - optind;
6152 input = xfopen_for_read(argv[optind]);
6153 close_on_exec_on(fileno(input));
6154 if (!signal_mask_is_inited)
6155 block_signals(0); /* 0: called 1st time */
6156 parse_and_run_file(input);
6157 #if ENABLE_FEATURE_CLEAN_UP
6163 /* Up to here, shell was non-interactive. Now it may become one.
6164 * NB: don't forget to (re)run block_signals(0/1) as needed.
6167 /* A shell is interactive if the '-i' flag was given, or if all of
6168 * the following conditions are met:
6170 * no arguments remaining or the -s flag given
6171 * standard input is a terminal
6172 * standard output is a terminal
6173 * Refer to Posix.2, the description of the 'sh' utility.
6176 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6177 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6178 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6179 //TODO: "interactive" and "have job control" are two different things.
6180 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6181 //should stay on! Currently, we mix these into one.
6182 if (G.saved_tty_pgrp >= 0) {
6183 /* try to dup stdin to high fd#, >= 255 */
6184 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6185 if (G_interactive_fd < 0) {
6186 /* try to dup to any fd */
6187 G_interactive_fd = dup(STDIN_FILENO);
6188 if (G_interactive_fd < 0)
6190 G_interactive_fd = 0;
6192 // TODO: track & disallow any attempts of user
6193 // to (inadvertently) close/redirect it
6196 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6197 if (G_interactive_fd) {
6200 /* We are indeed interactive shell, and we will perform
6201 * job control. Setting up for that. */
6203 close_on_exec_on(G_interactive_fd);
6204 /* If we were run as 'hush &', sleep until we are
6205 * in the foreground (tty pgrp == our pgrp).
6206 * If we get started under a job aware app (like bash),
6207 * make sure we are now in charge so we don't fight over
6208 * who gets the foreground */
6210 shell_pgrp = getpgrp();
6211 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6212 if (G.saved_tty_pgrp == shell_pgrp)
6214 /* send TTIN to ourself (should stop us) */
6215 kill(- shell_pgrp, SIGTTIN);
6217 /* Block some signals */
6218 block_signals(signal_mask_is_inited);
6219 /* Set other signals to restore saved_tty_pgrp */
6220 set_fatal_handlers();
6221 /* Put ourselves in our own process group */
6222 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6223 /* Grab control of the terminal */
6224 tcsetpgrp(G_interactive_fd, getpid());
6225 /* -1 is special - makes xfuncs longjmp, not exit
6226 * (we reset die_sleep = 0 whereever we [v]fork) */
6227 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6228 } else if (!signal_mask_is_inited) {
6229 block_signals(0); /* 0: called 1st time */
6230 } /* else: block_signals(0) was done before */
6231 #elif ENABLE_HUSH_INTERACTIVE
6232 /* No job control compiled in, only prompt/line editing */
6233 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6234 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6235 if (G_interactive_fd < 0) {
6236 /* try to dup to any fd */
6237 G_interactive_fd = dup(STDIN_FILENO);
6238 if (G_interactive_fd < 0)
6240 G_interactive_fd = 0;
6243 if (G_interactive_fd) {
6244 close_on_exec_on(G_interactive_fd);
6245 block_signals(signal_mask_is_inited);
6246 } else if (!signal_mask_is_inited) {
6250 /* We have interactiveness code disabled */
6251 if (!signal_mask_is_inited) {
6256 * if interactive but not a login shell, sources ~/.bashrc
6257 * (--norc turns this off, --rcfile <file> overrides)
6260 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6261 printf("\n\n%s hush - the humble shell\n", bb_banner);
6262 printf("Enter 'help' for a list of built-in commands.\n\n");
6265 parse_and_run_file(stdin);
6268 #if ENABLE_FEATURE_CLEAN_UP
6269 if (G.cwd != bb_msg_unknown)
6271 cur_var = G.top_var->next;
6273 struct variable *tmp = cur_var;
6274 if (!cur_var->max_len)
6275 free(cur_var->varstr);
6276 cur_var = cur_var->next;
6280 hush_exit(G.last_exitcode);
6285 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6286 int lash_main(int argc, char **argv)
6288 //bb_error_msg("lash is deprecated, please use hush instead");
6289 return hush_main(argc, argv);
6297 static int builtin_true(char **argv UNUSED_PARAM)
6302 static int builtin_test(char **argv)
6309 return test_main(argc, argv - argc);
6312 static int builtin_echo(char **argv)
6319 return echo_main(argc, argv - argc);
6322 static int builtin_eval(char **argv)
6324 int rcode = EXIT_SUCCESS;
6327 char *str = expand_strvec_to_string(argv);
6329 * eval "echo Hi; done" ("done" is syntax error):
6330 * "echo Hi" will not execute too.
6332 parse_and_run_string(str);
6334 rcode = G.last_exitcode;
6339 static int builtin_cd(char **argv)
6341 const char *newdir = argv[1];
6342 if (newdir == NULL) {
6343 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6344 * bash says "bash: cd: HOME not set" and does nothing
6347 newdir = get_local_var_value("HOME") ? : "/";
6349 if (chdir(newdir)) {
6350 /* Mimic bash message exactly */
6351 bb_perror_msg("cd: %s", newdir);
6352 return EXIT_FAILURE;
6355 return EXIT_SUCCESS;
6358 static int builtin_exec(char **argv)
6360 if (*++argv == NULL)
6361 return EXIT_SUCCESS; /* bash does this */
6366 /* TODO: if exec fails, bash does NOT exit! We do... */
6367 pseudo_exec_argv(&dummy, argv, 0, NULL);
6372 static int builtin_exit(char **argv)
6374 debug_printf_exec("%s()\n", __func__);
6376 /* interactive bash:
6377 * # trap "echo EEE" EXIT
6380 * There are stopped jobs.
6381 * (if there are _stopped_ jobs, running ones don't count)
6384 # EEE (then bash exits)
6386 * we can use G.exiting = -1 as indicator "last cmd was exit"
6389 /* note: EXIT trap is run by hush_exit */
6390 if (*++argv == NULL)
6391 hush_exit(G.last_exitcode);
6392 /* mimic bash: exit 123abc == exit 255 + error msg */
6393 xfunc_error_retval = 255;
6394 /* bash: exit -2 == exit 254, no error msg */
6395 hush_exit(xatoi(*argv) & 0xff);
6398 static void print_escaped(const char *s)
6404 p = strchrnul(s, '\'');
6405 /* print 'xxxx', possibly just '' */
6406 printf("'%.*s'", (int)(p - s), s);
6411 /* s points to '; print "'''...'''" */
6413 do putchar('\''); while (*++s == '\'');
6418 static int builtin_export(char **argv)
6420 unsigned opt_unexport;
6422 if (argv[1] == NULL) {
6429 /* ash emits: export VAR='VAL'
6430 * bash: declare -x VAR="VAL"
6431 * we follow ash example */
6432 const char *s = *e++;
6433 const char *p = strchr(s, '=');
6435 if (!p) /* wtf? take next variable */
6438 printf("export %.*s", (int)(p - s) + 1, s);
6439 print_escaped(p + 1);
6443 /*fflush(stdout); - done after each builtin anyway */
6445 return EXIT_SUCCESS;
6448 #if ENABLE_HUSH_EXPORT_N
6449 opt_unexport = getopt32(argv, "+n"); /* "+": stop at 1st non-option */
6459 /* So far we do not check that name is valid (TODO?) */
6461 if (strchr(name, '=') == NULL) {
6462 struct variable *var;
6464 var = get_local_var(name);
6466 /* export -n NAME (without =VALUE) */
6468 var->flg_export = 0;
6469 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
6471 } /* else: export -n NOT_EXISTING_VAR: no-op */
6474 /* export NAME (without =VALUE) */
6476 var->flg_export = 1;
6477 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6478 putenv(var->varstr);
6481 /* Exporting non-existing variable.
6482 * bash does not put it in environment,
6483 * but remembers that it is exported,
6484 * and does put it in env when it is set later.
6485 * We just set it to "" and export. */
6486 name = xasprintf("%s=", name);
6488 /* (Un)exporting NAME=VALUE */
6489 name = xstrdup(name);
6492 /*export:*/ (opt_unexport ? -1 : 1),
6497 return EXIT_SUCCESS;
6500 static int builtin_trap(char **argv)
6506 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6511 /* No args: print all trapped */
6512 for (i = 0; i < NSIG; ++i) {
6515 print_escaped(G.traps[i]);
6516 printf(" %s\n", get_signame(i));
6519 /*fflush(stdout); - done after each builtin anyway */
6520 return EXIT_SUCCESS;
6524 /* If first arg is a number: reset all specified signals */
6525 sig = bb_strtou(*argv, NULL, 10);
6531 sig = get_signum(*argv++);
6532 if (sig < 0 || sig >= NSIG) {
6534 /* Mimic bash message exactly */
6535 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
6540 G.traps[sig] = xstrdup(new_cmd);
6542 debug_printf("trap: setting SIG%s (%i) to '%s'",
6543 get_signame(sig), sig, G.traps[sig]);
6545 /* There is no signal for 0 (EXIT) */
6550 sigaddset(&G.blocked_set, sig);
6552 /* There was a trap handler, we are removing it
6553 * (if sig has non-DFL handling,
6554 * we don't need to do anything) */
6555 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6557 sigdelset(&G.blocked_set, sig);
6560 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6564 if (!argv[1]) { /* no second arg */
6565 bb_error_msg("trap: invalid arguments");
6566 return EXIT_FAILURE;
6569 /* First arg is "-": reset all specified to default */
6570 /* First arg is "--": skip it, the rest is "handler SIGs..." */
6571 /* Everything else: set arg as signal handler
6572 * (includes "" case, which ignores signal) */
6573 if (argv[0][0] == '-') {
6574 if (argv[0][1] == '\0') { /* "-" */
6575 /* new_cmd remains NULL: "reset these sigs" */
6578 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
6581 /* else: "-something", no special meaning */
6586 goto process_sig_list;
6590 /* built-in 'fg' and 'bg' handler */
6591 static int builtin_fg_bg(char **argv)
6596 if (!G_interactive_fd)
6597 return EXIT_FAILURE;
6598 /* If they gave us no args, assume they want the last backgrounded task */
6600 for (pi = G.job_list; pi; pi = pi->next) {
6601 if (pi->jobid == G.last_jobid) {
6605 bb_error_msg("%s: no current job", argv[0]);
6606 return EXIT_FAILURE;
6608 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6609 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6610 return EXIT_FAILURE;
6612 for (pi = G.job_list; pi; pi = pi->next) {
6613 if (pi->jobid == jobnum) {
6617 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6618 return EXIT_FAILURE;
6620 /* TODO: bash prints a string representation
6621 * of job being foregrounded (like "sleep 1 | cat") */
6622 if (argv[0][0] == 'f') {
6623 /* Put the job into the foreground. */
6624 tcsetpgrp(G_interactive_fd, pi->pgrp);
6627 /* Restart the processes in the job */
6628 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6629 for (i = 0; i < pi->num_cmds; i++) {
6630 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6631 pi->cmds[i].is_stopped = 0;
6633 pi->stopped_cmds = 0;
6635 i = kill(- pi->pgrp, SIGCONT);
6637 if (errno == ESRCH) {
6638 delete_finished_bg_job(pi);
6639 return EXIT_SUCCESS;
6641 bb_perror_msg("kill (SIGCONT)");
6644 if (argv[0][0] == 'f') {
6646 return checkjobs_and_fg_shell(pi);
6648 return EXIT_SUCCESS;
6652 #if ENABLE_HUSH_HELP
6653 static int builtin_help(char **argv UNUSED_PARAM)
6655 const struct built_in_command *x;
6658 "Built-in commands:\n"
6659 "------------------\n");
6660 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6661 printf("%s\t%s\n", x->cmd, x->descr);
6664 return EXIT_SUCCESS;
6669 static int builtin_jobs(char **argv UNUSED_PARAM)
6672 const char *status_string;
6674 for (job = G.job_list; job; job = job->next) {
6675 if (job->alive_cmds == job->stopped_cmds)
6676 status_string = "Stopped";
6678 status_string = "Running";
6680 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6682 return EXIT_SUCCESS;
6687 static int builtin_memleak(char **argv UNUSED_PARAM)
6692 /* Crude attempt to find where "free memory" starts,
6693 * sans fragmentation. */
6695 l = (unsigned long)p;
6698 if (l < (unsigned long)p) l = (unsigned long)p;
6701 if (!G.memleak_value)
6702 G.memleak_value = l;
6704 l -= G.memleak_value;
6711 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6716 static int builtin_pwd(char **argv UNUSED_PARAM)
6719 return EXIT_SUCCESS;
6722 static int builtin_read(char **argv)
6725 const char *name = "REPLY";
6729 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6730 * and _after_ that_ it will complain */
6731 if (!is_well_formed_var_name(name, '\0')) {
6732 /* Mimic bash message */
6733 bb_error_msg("read: '%s': not a valid identifier", name);
6738 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6740 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6741 return set_local_var(string, 0, 0);
6744 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6745 * built-in 'set' handler
6747 * set [-abCefhmnuvx] [-o option] [argument...]
6748 * set [+abCefhmnuvx] [+o option] [argument...]
6749 * set -- [argument...]
6752 * Implementations shall support the options in both their hyphen and
6753 * plus-sign forms. These options can also be specified as options to sh.
6755 * Write out all variables and their values: set
6756 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6757 * Turn on the -x and -v options: set -xv
6758 * Unset all positional parameters: set --
6759 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6760 * Set the positional parameters to the expansion of x, even if x expands
6761 * with a leading '-' or '+': set -- $x
6763 * So far, we only support "set -- [argument...]" and some of the short names.
6765 static int builtin_set(char **argv)
6768 char **pp, **g_argv;
6769 char *arg = *++argv;
6773 for (e = G.top_var; e; e = e->next)
6775 return EXIT_SUCCESS;
6779 if (!strcmp(arg, "--")) {
6783 if (arg[0] != '+' && arg[0] != '-')
6785 for (n = 1; arg[n]; ++n)
6786 if (set_mode(arg[0], arg[n]))
6788 } while ((arg = *++argv) != NULL);
6789 /* Now argv[0] is 1st argument */
6792 return EXIT_SUCCESS;
6795 /* NB: G.global_argv[0] ($0) is never freed/changed */
6796 g_argv = G.global_argv;
6797 if (G.global_args_malloced) {
6803 G.global_args_malloced = 1;
6804 pp = xzalloc(sizeof(pp[0]) * 2);
6805 pp[0] = g_argv[0]; /* retain $0 */
6808 /* This realloc's G.global_argv */
6809 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6816 return EXIT_SUCCESS;
6818 /* Nothing known, so abort */
6820 bb_error_msg("set: %s: invalid option", arg);
6821 return EXIT_FAILURE;
6824 static int builtin_shift(char **argv)
6830 if (n >= 0 && n < G.global_argc) {
6831 if (G.global_args_malloced) {
6834 free(G.global_argv[m++]);
6837 memmove(&G.global_argv[1], &G.global_argv[n+1],
6838 G.global_argc * sizeof(G.global_argv[0]));
6839 return EXIT_SUCCESS;
6841 return EXIT_FAILURE;
6844 static int builtin_source(char **argv)
6848 #if ENABLE_HUSH_FUNCTIONS
6852 if (*++argv == NULL)
6853 return EXIT_FAILURE;
6855 // TODO: search through $PATH is missing
6856 input = fopen_or_warn(*argv, "r");
6858 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6859 return EXIT_FAILURE;
6861 close_on_exec_on(fileno(input));
6863 #if ENABLE_HUSH_FUNCTIONS
6864 sv_flg = G.flag_return_in_progress;
6865 /* "we are inside sourced file, ok to use return" */
6866 G.flag_return_in_progress = -1;
6868 save_and_replace_G_args(&sv, argv);
6870 parse_and_run_file(input);
6873 restore_G_args(&sv, argv);
6874 #if ENABLE_HUSH_FUNCTIONS
6875 G.flag_return_in_progress = sv_flg;
6878 return G.last_exitcode;
6881 static int builtin_umask(char **argv)
6888 mode_t old_mask = mask;
6891 rc = bb_parse_mode(argv[1], &mask);
6896 * bash: umask: 'q': invalid symbolic mode operator
6897 * bash: umask: 999: octal number out of range
6899 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
6904 printf("%04o\n", (unsigned) mask);
6905 /* fall through and restore mask which we set to 0 */
6909 return !rc; /* rc != 0 - success */
6912 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6913 static int builtin_unset(char **argv)
6920 return EXIT_SUCCESS;
6923 while ((arg = *argv) != NULL && arg[0] == '-') {
6929 if (var == 0 || var == *arg) {
6933 /* else: unset -vf, which is illegal.
6936 bb_error_msg("unset: %s: invalid option", *argv);
6937 return EXIT_FAILURE;
6946 if (unset_local_var(*argv)) {
6947 /* unset <nonexistent_var> doesn't fail.
6948 * Error is when one tries to unset RO var.
6949 * Message was printed by unset_local_var. */
6953 #if ENABLE_HUSH_FUNCTIONS
6963 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6964 static int builtin_wait(char **argv)
6966 int ret = EXIT_SUCCESS;
6969 if (*++argv == NULL) {
6970 /* Don't care about wait results */
6971 /* Note 1: must wait until there are no more children */
6972 /* Note 2: must be interruptible */
6974 * $ sleep 3 & sleep 6 & wait
6979 * $ sleep 3 & sleep 6 & wait
6983 * ^C <-- after ~4 sec from keyboard
6986 sigaddset(&G.blocked_set, SIGCHLD);
6987 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6990 if (errno == ECHILD)
6992 /* Wait for SIGCHLD or any other signal of interest */
6993 /* sigtimedwait with infinite timeout: */
6994 sig = sigwaitinfo(&G.blocked_set, NULL);
6996 sig = check_and_run_traps(sig);
6997 if (sig && sig != SIGCHLD) { /* see note 2 */
7003 sigdelset(&G.blocked_set, SIGCHLD);
7004 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7008 /* This is probably buggy wrt interruptible-ness */
7010 pid_t pid = bb_strtou(*argv, NULL, 10);
7012 /* mimic bash message */
7013 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
7014 return EXIT_FAILURE;
7016 if (waitpid(pid, &status, 0) == pid) {
7017 if (WIFSIGNALED(status))
7018 ret = 128 + WTERMSIG(status);
7019 else if (WIFEXITED(status))
7020 ret = WEXITSTATUS(status);
7024 bb_perror_msg("wait %s", *argv);
7033 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
7034 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
7037 def = bb_strtou(argv[1], NULL, 10);
7038 if (errno || def < def_min || argv[2]) {
7039 bb_error_msg("%s: bad arguments", argv[0]);
7047 #if ENABLE_HUSH_LOOPS
7048 static int builtin_break(char **argv)
7051 if (G.depth_of_loop == 0) {
7052 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7053 return EXIT_SUCCESS; /* bash compat */
7055 G.flag_break_continue++; /* BC_BREAK = 1 */
7057 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
7058 if (depth == UINT_MAX)
7059 G.flag_break_continue = BC_BREAK;
7060 if (G.depth_of_loop < depth)
7061 G.depth_break_continue = G.depth_of_loop;
7063 return EXIT_SUCCESS;
7066 static int builtin_continue(char **argv)
7068 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
7069 return builtin_break(argv);
7073 #if ENABLE_HUSH_FUNCTIONS
7074 static int builtin_return(char **argv)
7078 if (G.flag_return_in_progress != -1) {
7079 bb_error_msg("%s: not in a function or sourced script", argv[0]);
7080 return EXIT_FAILURE; /* bash compat */
7083 G.flag_return_in_progress = 1;
7086 * out of range: wraps around at 256, does not error out
7087 * non-numeric param:
7088 * f() { false; return qwe; }; f; echo $?
7089 * bash: return: qwe: numeric argument required <== we do this
7090 * 255 <== we also do this
7092 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);