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 * builtins: return, ulimit
55 * follow IFS rules more precisely, including update semantics
56 * figure out what to do with backslash-newline
57 * continuation lines, both explicit and implicit - done?
59 * ^Z handling (and explain it in comments for mere humans)
60 * separate job control from interactiveness
61 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
63 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
65 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
67 /* #include <dmalloc.h> */
74 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
78 /* Debug build knobs */
79 #define LEAK_HUNTING 0
80 #define BUILD_AS_NOMMU 0
81 /* Enable/disable sanity checks. Ok to enable in production,
82 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
83 * Keeping 1 for now even in released versions.
93 # define USE_FOR_NOMMU(...) __VA_ARGS__
94 # define USE_FOR_MMU(...)
97 #if defined SINGLE_APPLET_MAIN
98 /* STANDALONE does not make sense, and won't compile */
99 # undef CONFIG_FEATURE_SH_STANDALONE
100 # undef ENABLE_FEATURE_SH_STANDALONE
101 # undef USE_FEATURE_SH_STANDALONE
102 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
103 # define ENABLE_FEATURE_SH_STANDALONE 0
104 # define USE_FEATURE_SH_STANDALONE(...)
105 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
108 #if !ENABLE_HUSH_INTERACTIVE
109 # undef ENABLE_FEATURE_EDITING
110 # define ENABLE_FEATURE_EDITING 0
111 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
112 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
115 /* Do we support ANY keywords? */
116 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
117 # define HAS_KEYWORDS 1
118 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
119 # define IF_HAS_NO_KEYWORDS(...)
121 # define HAS_KEYWORDS 0
122 # define IF_HAS_KEYWORDS(...)
123 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
126 /* If you comment out one of these below, it will be #defined later
127 * to perform debug printfs to stderr: */
128 #define debug_printf(...) do {} while (0)
129 /* Finer-grained debug switches */
130 #define debug_printf_parse(...) do {} while (0)
131 #define debug_print_tree(a, b) do {} while (0)
132 #define debug_printf_exec(...) do {} while (0)
133 #define debug_printf_env(...) do {} while (0)
134 #define debug_printf_jobs(...) do {} while (0)
135 #define debug_printf_expand(...) do {} while (0)
136 #define debug_printf_glob(...) do {} while (0)
137 #define debug_printf_list(...) do {} while (0)
138 #define debug_printf_subst(...) do {} while (0)
139 #define debug_printf_clean(...) do {} while (0)
141 #define ERR_PTR ((void*)(long)1)
143 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
145 #define SPECIAL_VAR_SYMBOL 3
147 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
149 /* This supports saving pointers malloced in vfork child,
150 * to be freed in the parent.
153 typedef struct nommu_save_t {
157 char **argv_from_re_execing;
161 /* The descrip member of this structure is only used to make
162 * debugging output pretty */
163 static const struct {
165 signed char default_fd;
169 { O_RDONLY, 0, "<" },
170 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
171 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
172 { O_RDONLY, 0, "<<" },
173 { O_CREAT|O_RDWR, 1, "<>" },
174 /* Should not be needed. Bogus default_fd helps in debugging */
175 /* { O_RDONLY, 77, "<<" }, */
178 typedef enum reserved_style {
187 #if ENABLE_HUSH_LOOPS
194 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
199 /* two pseudo-keywords support contrived "case" syntax: */
200 RES_MATCH , /* "word)" */
201 RES_CASEI , /* "this command is inside CASE" */
208 typedef struct o_string {
210 int length; /* position where data is appended */
212 /* Protect newly added chars against globbing
213 * (by prepending \ to *, ?, [, \) */
216 /* At least some part of the string was inside '' or "",
217 * possibly empty one: word"", wo''rd etc. */
219 smallint has_empty_slot;
220 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
223 MAYBE_ASSIGNMENT = 0,
224 DEFINITELY_ASSIGNMENT = 1,
226 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
228 /* Used for initialization: o_string foo = NULL_O_STRING; */
229 #define NULL_O_STRING { NULL }
231 /* I can almost use ordinary FILE*. Is open_memstream() universally
232 * available? Where is it documented? */
233 typedef struct in_str {
235 /* eof_flag=1: last char in ->p is really an EOF */
236 char eof_flag; /* meaningless if ->p == NULL */
238 #if ENABLE_HUSH_INTERACTIVE
240 smallint promptmode; /* 0: PS1, 1: PS2 */
243 int (*get) (struct in_str *);
244 int (*peek) (struct in_str *);
246 #define i_getch(input) ((input)->get(input))
247 #define i_peek(input) ((input)->peek(input))
249 struct redir_struct {
250 struct redir_struct *next;
251 char *rd_filename; /* filename */
252 int rd_fd; /* fd to redirect */
253 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
255 smallint rd_type; /* (enum redir_type) */
256 /* note: for heredocs, rd_filename contains heredoc delimiter,
257 * and subsequently heredoc itself; and rd_dup is a bitmask:
258 * 1: do we need to trim leading tabs?
259 * 2: is heredoc quoted (<<'delim' syntax) ?
262 typedef enum redir_type {
263 REDIRECT_INVALID = 0,
265 REDIRECT_OVERWRITE = 2,
267 REDIRECT_HEREDOC = 4,
269 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
272 REDIRFD_SYNTAX_ERR = -2,
273 REDIRFD_TO_FILE = -1,
274 /* otherwise, rd_fd is redirected to rd_dup */
276 HEREDOC_SKIPTABS = 1,
282 pid_t pid; /* 0 if exited */
283 int assignment_cnt; /* how many argv[i] are assignments? */
284 smallint is_stopped; /* is the command currently running? */
285 smallint grp_type; /* GRP_xxx */
287 #define GRP_SUBSHELL 1
288 #if ENABLE_HUSH_FUNCTIONS
289 # define GRP_FUNCTION 2
291 struct pipe *group; /* if non-NULL, this "command" is { list },
292 * ( list ), or a compound statement */
294 char *group_as_string;
296 #if ENABLE_HUSH_FUNCTIONS
297 struct function *child_func;
298 /* This field is used to prevent a bug here:
299 * while...do f1() {a;}; f1; f1 {b;}; f1; done
300 * When we execute "f1() {a;}" cmd, we create new function and clear
301 * cmd->group, cmd->group_as_string, cmd->argv[0].
302 * when we execute "f1 {b;}", we notice that f1 exists,
303 * and that it's "parent cmd" struct is still "alive",
304 * we put those fields back into cmd->xxx
305 * (struct function has ->parent_cmd ptr to facilitate that).
306 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
307 * Without this trick, loop would execute a;b;b;b;...
308 * instead of correct sequence a;b;a;b;...
309 * When command is freed, it severs the link
310 * (sets ->child_func->parent_cmd to NULL).
313 char **argv; /* command name and arguments */
314 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
315 * and on execution these are substituted with their values.
316 * Substitution can make _several_ words out of one argv[n]!
317 * Example: argv[0]=='.^C*^C.' here: echo .$*.
318 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
320 struct redir_struct *redirects; /* I/O redirections */
325 int num_cmds; /* total number of commands in pipe */
326 int alive_cmds; /* number of commands running (not exited) */
327 int stopped_cmds; /* number of commands alive, but stopped */
329 int jobid; /* job number */
330 pid_t pgrp; /* process group ID for the job */
331 char *cmdtext; /* name of job */
333 struct command *cmds; /* array of commands in pipe */
334 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
335 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
336 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
338 typedef enum pipe_style {
345 /* This holds pointers to the various results of parsing */
346 struct parse_context {
347 /* linked list of pipes */
348 struct pipe *list_head;
349 /* last pipe (being constructed right now) */
351 /* last command in pipe (being constructed right now) */
352 struct command *command;
353 /* last redirect in command->redirects list */
354 struct redir_struct *pending_redirect;
360 smallint ctx_inverted; /* "! cmd | cmd" */
362 smallint ctx_dsemicolon; /* ";;" seen */
364 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
366 /* group we are enclosed in:
367 * example: "if pipe1; pipe2; then pipe3; fi"
368 * when we see "if" or "then", we malloc and copy current context,
369 * and make ->stack point to it. then we parse pipeN.
370 * when closing "then" / fi" / whatever is found,
371 * we move list_head into ->stack->command->group,
372 * copy ->stack into current context, and delete ->stack.
373 * (parsing of { list } and ( list ) doesn't use this method)
375 struct parse_context *stack;
379 /* On program start, environ points to initial environment.
380 * putenv adds new pointers into it, unsetenv removes them.
381 * Neither of these (de)allocates the strings.
382 * setenv allocates new strings in malloc space and does putenv,
383 * and thus setenv is unusable (leaky) for shell's purposes */
384 #define setenv(...) setenv_is_leaky_dont_use()
386 struct variable *next;
387 char *varstr; /* points to "name=" portion */
388 int max_len; /* if > 0, name is part of initial env; else name is malloced */
389 smallint flg_export; /* putenv should be done on this var */
390 smallint flg_read_only;
398 #if ENABLE_HUSH_FUNCTIONS
400 struct function *next;
402 struct command *parent_cmd;
405 char *body_as_string;
411 /* "Globals" within this file */
412 /* Sorted roughly by size (smaller offsets == smaller code) */
414 #if ENABLE_HUSH_INTERACTIVE
415 /* 'interactive_fd' is a fd# open to ctty, if we have one
416 * _AND_ if we decided to act interactively */
420 #define G_interactive_fd (G.interactive_fd)
422 #define G_interactive_fd 0
424 #if ENABLE_FEATURE_EDITING
425 line_input_t *line_input_state;
431 pid_t saved_tty_pgrp;
433 struct pipe *job_list;
434 struct pipe *toplevel_list;
435 //// smallint ctrl_z_flag;
437 smallint flag_SIGINT;
438 #if ENABLE_HUSH_LOOPS
439 smallint flag_break_continue;
442 smallint exiting; /* used to prevent EXIT trap recursion */
443 /* These four support $?, $#, and $1 */
444 smalluint last_exitcode;
445 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
446 smalluint global_args_malloced;
447 /* how many non-NULL argv's we have. NB: $# + 1 */
451 char *argv0_for_re_execing;
453 #if ENABLE_HUSH_LOOPS
454 unsigned depth_break_continue;
455 unsigned depth_of_loop;
459 struct variable *top_var; /* = &G.shell_ver (set in main()) */
460 struct variable shell_ver;
461 #if ENABLE_HUSH_FUNCTIONS
462 struct function *top_func;
464 /* Signal and trap handling */
465 // unsigned count_SIGCHLD;
466 // unsigned handled_SIGCHLD;
467 /* which signals have non-DFL handler (even with no traps set)? */
468 unsigned non_DFL_mask;
469 char **traps; /* char *traps[NSIG] */
470 sigset_t blocked_set;
471 sigset_t inherited_set;
473 unsigned long memleak_value;
476 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
477 #if ENABLE_FEATURE_SH_STANDALONE
478 struct nofork_save_area nofork_save;
481 sigjmp_buf toplevel_jb;
484 #define G (*ptr_to_globals)
485 /* Not #defining name to G.name - this quickly gets unwieldy
486 * (too many defines). Also, I actually prefer to see when a variable
487 * is global, thus "G." prefix is a useful hint */
488 #define INIT_G() do { \
489 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
493 /* Function prototypes for builtins */
494 static int builtin_cd(char **argv);
495 static int builtin_echo(char **argv);
496 static int builtin_eval(char **argv);
497 static int builtin_exec(char **argv);
498 static int builtin_exit(char **argv);
499 static int builtin_export(char **argv);
501 static int builtin_fg_bg(char **argv);
502 static int builtin_jobs(char **argv);
505 static int builtin_help(char **argv);
508 static int builtin_memleak(char **argv);
510 static int builtin_pwd(char **argv);
511 static int builtin_read(char **argv);
512 static int builtin_set(char **argv);
513 static int builtin_shift(char **argv);
514 static int builtin_source(char **argv);
515 static int builtin_test(char **argv);
516 static int builtin_trap(char **argv);
517 static int builtin_true(char **argv);
518 static int builtin_umask(char **argv);
519 static int builtin_unset(char **argv);
520 static int builtin_wait(char **argv);
521 #if ENABLE_HUSH_LOOPS
522 static int builtin_break(char **argv);
523 static int builtin_continue(char **argv);
526 /* Table of built-in functions. They can be forked or not, depending on
527 * context: within pipes, they fork. As simple commands, they do not.
528 * When used in non-forking context, they can change global variables
529 * in the parent shell process. If forked, of course they cannot.
530 * For example, 'unset foo | whatever' will parse and run, but foo will
531 * still be set at the end. */
532 struct built_in_command {
534 int (*function)(char **argv);
537 #define BLTIN(cmd, func, help) { cmd, func, help }
539 #define BLTIN(cmd, func, help) { cmd, func }
543 /* For now, echo and test are unconditionally enabled.
544 * Maybe make it configurable? */
545 static const struct built_in_command bltins[] = {
546 BLTIN("." , builtin_source , "Run commands in a file"),
547 BLTIN(":" , builtin_true , "No-op"),
548 BLTIN("[" , builtin_test , "Test condition"),
550 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
552 #if ENABLE_HUSH_LOOPS
553 BLTIN("break" , builtin_break , "Exit from a loop"),
555 BLTIN("cd" , builtin_cd , "Change directory"),
556 #if ENABLE_HUSH_LOOPS
557 BLTIN("continue", builtin_continue, "Start new loop iteration"),
559 BLTIN("echo" , builtin_echo , "Write to stdout"),
560 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
561 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
562 BLTIN("exit" , builtin_exit , "Exit"),
563 BLTIN("export" , builtin_export , "Set environment variable"),
565 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
568 BLTIN("help" , builtin_help , "List shell built-in commands"),
571 BLTIN("jobs" , builtin_jobs , "List active jobs"),
574 BLTIN("memleak" , builtin_memleak , "Debug tool"),
576 BLTIN("pwd" , builtin_pwd , "Print current directory"),
577 BLTIN("read" , builtin_read , "Input environment variable"),
578 // BLTIN("return" , builtin_return , "Return from a function"),
579 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
580 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
581 BLTIN("test" , builtin_test , "Test condition"),
582 BLTIN("trap" , builtin_trap , "Trap signals"),
583 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
584 BLTIN("umask" , builtin_umask , "Set file creation mask"),
585 BLTIN("unset" , builtin_unset , "Unset environment variable"),
586 BLTIN("wait" , builtin_wait , "Wait for process"),
593 /* prevent disasters with G.debug_indent < 0 */
594 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
595 # define debug_enter() (G.debug_indent++)
596 # define debug_leave() (G.debug_indent--)
598 # define indent() ((void)0)
599 # define debug_enter() ((void)0)
600 # define debug_leave() ((void)0)
604 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
607 #ifndef debug_printf_parse
608 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
611 #ifndef debug_printf_exec
612 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
615 #ifndef debug_printf_env
616 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
619 #ifndef debug_printf_jobs
620 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
621 # define DEBUG_JOBS 1
623 # define DEBUG_JOBS 0
626 #ifndef debug_printf_expand
627 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
628 # define DEBUG_EXPAND 1
630 # define DEBUG_EXPAND 0
633 #ifndef debug_printf_glob
634 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
635 # define DEBUG_GLOB 1
637 # define DEBUG_GLOB 0
640 #ifndef debug_printf_list
641 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
644 #ifndef debug_printf_subst
645 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
648 #ifndef debug_printf_clean
649 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
650 # define DEBUG_CLEAN 1
652 # define DEBUG_CLEAN 0
656 static void debug_print_strings(const char *prefix, char **vv)
659 fprintf(stderr, "%s:\n", prefix);
661 fprintf(stderr, " '%s'\n", *vv++);
664 #define debug_print_strings(prefix, vv) ((void)0)
668 /* Leak hunting. Use hush_leaktool.sh for post-processing.
671 static void *xxmalloc(int lineno, size_t size)
673 void *ptr = xmalloc((size + 0xff) & ~0xff);
674 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
677 static void *xxrealloc(int lineno, void *ptr, size_t size)
679 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
680 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
683 static char *xxstrdup(int lineno, const char *str)
685 char *ptr = xstrdup(str);
686 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
689 static void xxfree(void *ptr)
691 fdprintf(2, "free %p\n", ptr);
694 #define xmalloc(s) xxmalloc(__LINE__, s)
695 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
696 #define xstrdup(s) xxstrdup(__LINE__, s)
697 #define free(p) xxfree(p)
701 /* Syntax and runtime errors. They always abort scripts.
702 * In interactive use they usually discard unparsed and/or unexecuted commands
703 * and return to the prompt.
704 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
707 # define die_if_script(lineno, fmt...) die_if_script(fmt)
708 # define syntax_error(lineno, msg) syntax_error(msg)
709 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
710 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
711 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
712 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
715 static void die_if_script(unsigned lineno, const char *fmt, ...)
720 bb_error_msg("hush.c:%u", lineno);
723 bb_verror_msg(fmt, p, NULL);
725 if (!G_interactive_fd)
729 static void syntax_error(unsigned lineno, const char *msg)
732 die_if_script(lineno, "syntax error: %s", msg);
734 die_if_script(lineno, "syntax error", NULL);
737 static void syntax_error_at(unsigned lineno, const char *msg)
739 die_if_script(lineno, "syntax error at '%s'", msg);
742 /* It so happens that all such cases are totally fatal
743 * even if shell is interactive: EOF while looking for closing
744 * delimiter. There is nowhere to read stuff from after that,
745 * it's EOF! The only choice is to terminate.
747 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
748 static void syntax_error_unterm_ch(unsigned lineno, char ch)
753 die_if_script(lineno, "syntax error: unterminated %s", msg);
757 static void syntax_error_unterm_str(unsigned lineno, const char *s)
759 die_if_script(lineno, "syntax error: unterminated %s", s);
762 static void syntax_error_unexpected_ch(unsigned lineno, char ch)
767 die_if_script(lineno, "syntax error: unexpected %s", msg);
771 # undef die_if_script
773 # undef syntax_error_at
774 # undef syntax_error_unterm_ch
775 # undef syntax_error_unterm_str
776 # undef syntax_error_unexpected_ch
778 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
779 # define syntax_error(msg) syntax_error(__LINE__, msg)
780 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
781 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
782 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
783 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
789 static int glob_needed(const char *s)
794 if (*s == '*' || *s == '[' || *s == '?')
801 static int is_well_formed_var_name(const char *s, char terminator)
803 if (!s || !(isalpha(*s) || *s == '_'))
806 while (isalnum(*s) || *s == '_')
808 return *s == terminator;
811 /* Replace each \x with x in place, return ptr past NUL. */
812 static char *unbackslash(char *src)
818 if ((*dst++ = *src++) == '\0')
824 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
845 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
846 v[count1 + count2] = NULL;
849 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
853 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
855 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
856 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
859 #define add_strings_to_strings(strings, add, need_to_dup) \
860 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
863 static char **add_string_to_strings(char **strings, char *add)
868 return add_strings_to_strings(strings, v, /*dup:*/ 0);
871 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
873 char **ptr = add_string_to_strings(strings, add);
874 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
877 #define add_string_to_strings(strings, add) \
878 xx_add_string_to_strings(__LINE__, strings, add)
881 static void putenv_all(char **strings)
886 debug_printf_env("putenv '%s'\n", *strings);
891 static char **putenv_all_and_save_old(char **strings)
901 eq = strchr(*strings, '=');
904 v = getenv(*strings);
907 /* v points to VAL in VAR=VAL, go back to VAR */
908 v -= (eq - *strings) + 1;
909 old = add_string_to_strings(old, v);
918 static void free_strings_and_unsetenv(char **strings, int unset)
928 debug_printf_env("unsetenv '%s'\n", *v);
936 static void free_strings(char **strings)
938 free_strings_and_unsetenv(strings, 0);
942 /* Basic theory of signal handling in shell
943 * ========================================
944 * This does not describe what hush does, rather, it is current understanding
945 * what it _should_ do. If it doesn't, it's a bug.
946 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
948 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
949 * is finished or backgrounded. It is the same in interactive and
950 * non-interactive shells, and is the same regardless of whether
951 * a user trap handler is installed or a shell special one is in effect.
952 * ^C or ^Z from keyboard seem to execute "at once" because it usually
953 * backgrounds (i.e. stops) or kills all members of currently running
956 * Wait builtin in interruptible by signals for which user trap is set
957 * or by SIGINT in interactive shell.
959 * Trap handlers will execute even within trap handlers. (right?)
961 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
963 * If job control is off, backgrounded commands ("cmd &")
964 * have SIGINT, SIGQUIT set to SIG_IGN.
966 * Commands run in command substitution ("`cmd`")
967 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
969 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
970 * by the shell from its parent.
972 * Siganls which differ from SIG_DFL action
973 * (note: child (i.e., [v]forked) shell is not an interactive shell):
976 * SIGTERM (interactive): ignore
977 * SIGHUP (interactive):
978 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
979 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
980 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
981 * that all pipe members are stopped) (right?)
982 * SIGINT (interactive): wait for last pipe, ignore the rest
983 * of the command line, show prompt. NB: ^C does not send SIGINT
984 * to interactive shell while shell is waiting for a pipe,
985 * since shell is bg'ed (is not in foreground process group).
986 * (check/expand this)
987 * Example 1: this waits 5 sec, but does not execute ls:
988 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
989 * Example 2: this does not wait and does not execute ls:
990 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
991 * Example 3: this does not wait 5 sec, but executes ls:
992 * "sleep 5; ls -l" + press ^C
994 * (What happens to signals which are IGN on shell start?)
995 * (What happens with signal mask on shell start?)
997 * Implementation in hush
998 * ======================
999 * We use in-kernel pending signal mask to determine which signals were sent.
1000 * We block all signals which we don't want to take action immediately,
1001 * i.e. we block all signals which need to have special handling as described
1002 * above, and all signals which have traps set.
1003 * After each pipe execution, we extract any pending signals via sigtimedwait()
1006 * unsigned non_DFL_mask: a mask of such "special" signals
1007 * sigset_t blocked_set: current blocked signal set
1010 * clear bit in blocked_set unless it is also in non_DFL_mask
1011 * "trap 'cmd' SIGxxx":
1012 * set bit in blocked_set (even if 'cmd' is '')
1013 * after [v]fork, if we plan to be a shell:
1014 * nothing for {} child shell (say, "true | { true; true; } | true")
1015 * unset all traps if () shell.
1016 * after [v]fork, if we plan to exec:
1017 * POSIX says pending signal mask is cleared in child - no need to clear it.
1018 * Restore blocked signal set to one inherited by shell just prior to exec.
1020 * Note: as a result, we do not use signal handlers much. The only uses
1021 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
1022 * and to restore tty pgrp on signal-induced exit.
1025 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1027 // G.count_SIGCHLD++;
1030 static int check_and_run_traps(int sig)
1032 static const struct timespec zero_timespec = { 0, 0 };
1033 smalluint save_rcode;
1039 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1044 if (G.traps && G.traps[sig]) {
1045 if (G.traps[sig][0]) {
1046 /* We have user-defined handler */
1047 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1048 save_rcode = G.last_exitcode;
1051 G.last_exitcode = save_rcode;
1052 } /* else: "" trap, ignoring signal */
1055 /* not a trap: special action */
1058 // G.count_SIGCHLD++;
1067 default: /* ignored: */
1068 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1077 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1078 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1079 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1080 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1082 /* Restores tty foreground process group, and exits.
1083 * May be called as signal handler for fatal signal
1084 * (will faithfully resend signal to itself, producing correct exit state)
1085 * or called directly with -EXITCODE.
1086 * We also call it if xfunc is exiting. */
1087 static void sigexit(int sig) NORETURN;
1088 static void sigexit(int sig)
1090 /* Disable all signals: job control, SIGPIPE, etc. */
1091 sigprocmask_allsigs(SIG_BLOCK);
1093 /* Careful: we can end up here after [v]fork. Do not restore
1094 * tty pgrp then, only top-level shell process does that */
1095 if (G_interactive_fd && getpid() == G.root_pid)
1096 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1098 /* Not a signal, just exit */
1102 kill_myself_with_sig(sig); /* does not return */
1106 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1107 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1111 /* Restores tty foreground process group, and exits. */
1112 static void hush_exit(int exitcode) NORETURN;
1113 static void hush_exit(int exitcode)
1115 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1116 /* Prevent recursion:
1117 * trap "echo Hi; exit" EXIT; exit
1119 char *argv[] = { NULL, G.traps[0], NULL };
1127 fflush(NULL); /* flush all streams */
1128 sigexit(- (exitcode & 0xff));
1135 static const char *set_cwd(void)
1137 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1138 * we must not try to free(bb_msg_unknown) */
1139 if (G.cwd == bb_msg_unknown)
1141 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1143 G.cwd = bb_msg_unknown;
1148 /* Get/check local shell variables */
1149 static struct variable *get_local_var(const char *name)
1151 struct variable *cur;
1157 for (cur = G.top_var; cur; cur = cur->next) {
1158 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1164 static const char *get_local_var_value(const char *src)
1166 struct variable *var = get_local_var(src);
1168 return strchr(var->varstr, '=') + 1;
1172 /* str holds "NAME=VAL" and is expected to be malloced.
1173 * We take ownership of it.
1177 * -1: if NAME is set, leave export status alone
1178 * if NAME is not set, do not export
1179 * flg_read_only is set only when we handle -R var=val
1182 #define set_local_var(str, flg_export, flg_read_only) \
1183 set_local_var(str, flg_export)
1185 static int set_local_var(char *str, int flg_export, int flg_read_only)
1187 struct variable *cur;
1191 value = strchr(str, '=');
1192 if (!value) { /* not expected to ever happen? */
1197 name_len = value - str + 1; /* including '=' */
1198 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1200 if (strncmp(cur->varstr, str, name_len) != 0) {
1202 /* Bail out. Note that now cur points
1203 * to last var in linked list */
1209 /* We found an existing var with this name */
1211 if (cur->flg_read_only) {
1215 bb_error_msg("%s: readonly variable", str);
1219 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1220 unsetenv(str); /* just in case */
1222 if (strcmp(cur->varstr, str) == 0) {
1227 if (cur->max_len >= strlen(str)) {
1228 /* This one is from startup env, reuse space */
1229 strcpy(cur->varstr, str);
1232 /* max_len == 0 signifies "malloced" var, which we can
1233 * (and has to) free */
1237 goto set_str_and_exp;
1240 /* Not found - create next variable struct */
1241 cur->next = xzalloc(sizeof(*cur));
1247 cur->flg_read_only = flg_read_only;
1250 if (flg_export == 1)
1251 cur->flg_export = 1;
1252 if (cur->flg_export) {
1253 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1254 return putenv(cur->varstr);
1259 static int unset_local_var(const char *name)
1261 struct variable *cur;
1262 struct variable *prev = prev; /* for gcc */
1266 return EXIT_SUCCESS;
1267 name_len = strlen(name);
1270 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1271 if (cur->flg_read_only) {
1272 bb_error_msg("%s: readonly variable", name);
1273 return EXIT_FAILURE;
1275 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1276 * is ro, and we cannot reach this code on the 1st pass */
1277 prev->next = cur->next;
1278 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1279 bb_unsetenv(cur->varstr);
1283 return EXIT_SUCCESS;
1288 return EXIT_SUCCESS;
1291 #if ENABLE_SH_MATH_SUPPORT
1292 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1293 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1294 static char *endofname(const char *name)
1302 if (!is_in_name(*p))
1308 static void arith_set_local_var(const char *name, const char *val, int flags)
1310 /* arith code doesnt malloc space, so do it for it */
1311 char *var = xasprintf("%s=%s", name, val);
1312 set_local_var(var, flags, 0);
1320 static int static_get(struct in_str *i)
1329 static int static_peek(struct in_str *i)
1334 #if ENABLE_HUSH_INTERACTIVE
1336 static void cmdedit_set_initial_prompt(void)
1338 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1339 G.PS1 = getenv("PS1");
1346 static const char* setup_prompt_string(int promptmode)
1348 const char *prompt_str;
1349 debug_printf("setup_prompt_string %d ", promptmode);
1350 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1351 /* Set up the prompt */
1352 if (promptmode == 0) { /* PS1 */
1354 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1359 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1360 debug_printf("result '%s'\n", prompt_str);
1364 static void get_user_input(struct in_str *i)
1367 const char *prompt_str;
1369 prompt_str = setup_prompt_string(i->promptmode);
1370 #if ENABLE_FEATURE_EDITING
1371 /* Enable command line editing only while a command line
1372 * is actually being read */
1375 /* buglet: SIGINT will not make new prompt to appear _at once_,
1376 * only after <Enter>. (^C will work) */
1377 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1378 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1379 check_and_run_traps(0);
1380 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1381 i->eof_flag = (r < 0);
1382 if (i->eof_flag) { /* EOF/error detected */
1383 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1384 G.user_input_buf[1] = '\0';
1389 fputs(prompt_str, stdout);
1391 G.user_input_buf[0] = r = fgetc(i->file);
1392 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1393 //do we need check_and_run_traps(0)? (maybe only if stdin)
1394 } while (G.flag_SIGINT);
1395 i->eof_flag = (r == EOF);
1397 i->p = G.user_input_buf;
1400 #endif /* INTERACTIVE */
1402 /* This is the magic location that prints prompts
1403 * and gets data back from the user */
1404 static int file_get(struct in_str *i)
1408 /* If there is data waiting, eat it up */
1409 if (i->p && *i->p) {
1410 #if ENABLE_HUSH_INTERACTIVE
1414 if (i->eof_flag && !*i->p)
1416 /* note: ch is never NUL */
1418 /* need to double check i->file because we might be doing something
1419 * more complicated by now, like sourcing or substituting. */
1420 #if ENABLE_HUSH_INTERACTIVE
1421 if (G_interactive_fd && i->promptme && i->file == stdin) {
1424 } while (!*i->p); /* need non-empty line */
1425 i->promptmode = 1; /* PS2 */
1430 do ch = fgetc(i->file); while (ch == '\0');
1432 debug_printf("file_get: got '%c' %d\n", ch, ch);
1433 #if ENABLE_HUSH_INTERACTIVE
1440 /* All callers guarantee this routine will never
1441 * be used right after a newline, so prompting is not needed.
1443 static int file_peek(struct in_str *i)
1446 if (i->p && *i->p) {
1447 if (i->eof_flag && !i->p[1])
1450 /* note: ch is never NUL */
1452 do ch = fgetc(i->file); while (ch == '\0');
1453 i->eof_flag = (ch == EOF);
1454 i->peek_buf[0] = ch;
1455 i->peek_buf[1] = '\0';
1457 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1461 static void setup_file_in_str(struct in_str *i, FILE *f)
1463 i->peek = file_peek;
1465 #if ENABLE_HUSH_INTERACTIVE
1467 i->promptmode = 0; /* PS1 */
1473 static void setup_string_in_str(struct in_str *i, const char *s)
1475 i->peek = static_peek;
1476 i->get = static_get;
1477 #if ENABLE_HUSH_INTERACTIVE
1479 i->promptmode = 0; /* PS1 */
1489 #define B_CHUNK (32 * sizeof(char*))
1491 static void o_reset_to_empty_unquoted(o_string *o)
1499 static void o_free(o_string *o)
1502 memset(o, 0, sizeof(*o));
1505 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1510 static void o_grow_by(o_string *o, int len)
1512 if (o->length + len > o->maxlen) {
1513 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1514 o->data = xrealloc(o->data, 1 + o->maxlen);
1518 static void o_addchr(o_string *o, int ch)
1520 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1522 o->data[o->length] = ch;
1524 o->data[o->length] = '\0';
1527 static void o_addblock(o_string *o, const char *str, int len)
1530 memcpy(&o->data[o->length], str, len);
1532 o->data[o->length] = '\0';
1536 static void o_addstr(o_string *o, const char *str)
1538 o_addblock(o, str, strlen(str));
1540 static void nommu_addchr(o_string *o, int ch)
1546 #define nommu_addchr(o, str) ((void)0)
1549 static void o_addstr_with_NUL(o_string *o, const char *str)
1551 o_addblock(o, str, strlen(str) + 1);
1554 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1559 && (*str != '*' && *str != '?' && *str != '[')
1567 /* My analysis of quoting semantics tells me that state information
1568 * is associated with a destination, not a source.
1570 static void o_addqchr(o_string *o, int ch)
1573 char *found = strchr("*?[\\", ch);
1578 o->data[o->length] = '\\';
1581 o->data[o->length] = ch;
1583 o->data[o->length] = '\0';
1586 static void o_addQchr(o_string *o, int ch)
1589 if (o->o_escape && strchr("*?[\\", ch)) {
1591 o->data[o->length] = '\\';
1595 o->data[o->length] = ch;
1597 o->data[o->length] = '\0';
1600 static void o_addQstr(o_string *o, const char *str, int len)
1603 o_addblock(o, str, len);
1609 int ordinary_cnt = strcspn(str, "*?[\\");
1610 if (ordinary_cnt > len) /* paranoia */
1612 o_addblock(o, str, ordinary_cnt);
1613 if (ordinary_cnt == len)
1615 str += ordinary_cnt;
1616 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1620 if (ch) { /* it is necessarily one of "*?[\\" */
1622 o->data[o->length] = '\\';
1626 o->data[o->length] = ch;
1628 o->data[o->length] = '\0';
1632 /* A special kind of o_string for $VAR and `cmd` expansion.
1633 * It contains char* list[] at the beginning, which is grown in 16 element
1634 * increments. Actual string data starts at the next multiple of 16 * (char*).
1635 * list[i] contains an INDEX (int!) into this string data.
1636 * It means that if list[] needs to grow, data needs to be moved higher up
1637 * but list[i]'s need not be modified.
1638 * NB: remembering how many list[i]'s you have there is crucial.
1639 * o_finalize_list() operation post-processes this structure - calculates
1640 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1642 #if DEBUG_EXPAND || DEBUG_GLOB
1643 static void debug_print_list(const char *prefix, o_string *o, int n)
1645 char **list = (char**)o->data;
1646 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1650 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1651 prefix, list, n, string_start, o->length, o->maxlen);
1654 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1655 o->data + (int)list[i] + string_start,
1656 o->data + (int)list[i] + string_start);
1660 const char *p = o->data + (int)list[n - 1] + string_start;
1662 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1666 #define debug_print_list(prefix, o, n) ((void)0)
1669 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1670 * in list[n] so that it points past last stored byte so far.
1671 * It returns n+1. */
1672 static int o_save_ptr_helper(o_string *o, int n)
1674 char **list = (char**)o->data;
1678 if (!o->has_empty_slot) {
1679 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1680 string_len = o->length - string_start;
1681 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1682 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1683 /* list[n] points to string_start, make space for 16 more pointers */
1684 o->maxlen += 0x10 * sizeof(list[0]);
1685 o->data = xrealloc(o->data, o->maxlen + 1);
1686 list = (char**)o->data;
1687 memmove(list + n + 0x10, list + n, string_len);
1688 o->length += 0x10 * sizeof(list[0]);
1690 debug_printf_list("list[%d]=%d string_start=%d\n",
1691 n, string_len, string_start);
1694 /* We have empty slot at list[n], reuse without growth */
1695 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1696 string_len = o->length - string_start;
1697 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1698 n, string_len, string_start);
1699 o->has_empty_slot = 0;
1701 list[n] = (char*)(ptrdiff_t)string_len;
1705 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1706 static int o_get_last_ptr(o_string *o, int n)
1708 char **list = (char**)o->data;
1709 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1711 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1714 /* o_glob performs globbing on last list[], saving each result
1715 * as a new list[]. */
1716 static int o_glob(o_string *o, int n)
1722 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1724 return o_save_ptr_helper(o, n);
1725 pattern = o->data + o_get_last_ptr(o, n);
1726 debug_printf_glob("glob pattern '%s'\n", pattern);
1727 if (!glob_needed(pattern)) {
1729 o->length = unbackslash(pattern) - o->data;
1730 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1731 return o_save_ptr_helper(o, n);
1734 memset(&globdata, 0, sizeof(globdata));
1735 gr = glob(pattern, 0, NULL, &globdata);
1736 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1737 if (gr == GLOB_NOSPACE)
1738 bb_error_msg_and_die("out of memory during glob");
1739 if (gr == GLOB_NOMATCH) {
1740 globfree(&globdata);
1743 if (gr != 0) { /* GLOB_ABORTED ? */
1744 //TODO: testcase for bad glob pattern behavior
1745 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1747 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1748 char **argv = globdata.gl_pathv;
1749 o->length = pattern - o->data; /* "forget" pattern */
1751 o_addstr_with_NUL(o, *argv);
1752 n = o_save_ptr_helper(o, n);
1758 globfree(&globdata);
1760 debug_print_list("o_glob returning", o, n);
1764 /* If o->o_glob == 1, glob the string so far remembered.
1765 * Otherwise, just finish current list[] and start new */
1766 static int o_save_ptr(o_string *o, int n)
1768 if (o->o_glob) { /* if globbing is requested */
1769 /* If o->has_empty_slot, list[n] was already globbed
1770 * (if it was requested back then when it was filled)
1771 * so don't do that again! */
1772 if (!o->has_empty_slot)
1773 return o_glob(o, n); /* o_save_ptr_helper is inside */
1775 return o_save_ptr_helper(o, n);
1778 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1779 static char **o_finalize_list(o_string *o, int n)
1784 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1786 debug_print_list("finalized", o, n);
1787 debug_printf_expand("finalized n:%d\n", n);
1788 list = (char**)o->data;
1789 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1793 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1799 /* Expansion can recurse */
1800 #if ENABLE_HUSH_TICK
1801 static int process_command_subs(o_string *dest, const char *s);
1803 static char *expand_string_to_string(const char *str);
1805 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1806 parse_stream_dquoted(dest, input, dquote_end)
1808 static int parse_stream_dquoted(o_string *as_string,
1810 struct in_str *input,
1813 /* expand_strvec_to_strvec() takes a list of strings, expands
1814 * all variable references within and returns a pointer to
1815 * a list of expanded strings, possibly with larger number
1816 * of strings. (Think VAR="a b"; echo $VAR).
1817 * This new list is allocated as a single malloc block.
1818 * NULL-terminated list of char* pointers is at the beginning of it,
1819 * followed by strings themself.
1820 * Caller can deallocate entire list by single free(list). */
1822 /* Store given string, finalizing the word and starting new one whenever
1823 * we encounter IFS char(s). This is used for expanding variable values.
1824 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1825 static int expand_on_ifs(o_string *output, int n, const char *str)
1828 int word_len = strcspn(str, G.ifs);
1830 if (output->o_escape || !output->o_glob)
1831 o_addQstr(output, str, word_len);
1832 else /* protect backslashes against globbing up :) */
1833 o_addblock_duplicate_backslash(output, str, word_len);
1836 if (!*str) /* EOL - do not finalize word */
1838 o_addchr(output, '\0');
1839 debug_print_list("expand_on_ifs", output, n);
1840 n = o_save_ptr(output, n);
1841 str += strspn(str, G.ifs); /* skip ifs chars */
1843 debug_print_list("expand_on_ifs[1]", output, n);
1847 /* Helper to expand $((...)) and heredoc body. These act as if
1848 * they are in double quotes, with the exception that they are not :).
1849 * Just the rules are similar: "expand only $var and `cmd`"
1851 * Returns malloced string.
1852 * As an optimization, we return NULL if expansion is not needed.
1854 static char *expand_pseudo_dquoted(const char *str)
1857 struct in_str input;
1858 o_string dest = NULL_O_STRING;
1860 if (strchr(str, '$') == NULL
1861 #if ENABLE_HUSH_TICK
1862 && strchr(str, '`') == NULL
1868 /* We need to expand. Example:
1869 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1871 setup_string_in_str(&input, str);
1872 parse_stream_dquoted(NULL, &dest, &input, EOF);
1873 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1874 exp_str = expand_string_to_string(dest.data);
1875 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1876 o_free_unsafe(&dest);
1880 /* Expand all variable references in given string, adding words to list[]
1881 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1882 * to be filled). This routine is extremely tricky: has to deal with
1883 * variables/parameters with whitespace, $* and $@, and constructs like
1884 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1885 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1887 /* or_mask is either 0 (normal case) or 0x80
1888 * (expansion of right-hand side of assignment == 1-element expand.
1889 * It will also do no globbing, and thus we must not backslash-quote!) */
1891 char first_ch, ored_ch;
1899 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1900 debug_print_list("expand_vars_to_list", output, n);
1901 n = o_save_ptr(output, n);
1902 debug_print_list("expand_vars_to_list[0]", output, n);
1904 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1905 #if ENABLE_HUSH_TICK
1906 o_string subst_result = NULL_O_STRING;
1908 #if ENABLE_SH_MATH_SUPPORT
1909 char arith_buf[sizeof(arith_t)*3 + 2];
1911 o_addblock(output, arg, p - arg);
1912 debug_print_list("expand_vars_to_list[1]", output, n);
1914 p = strchr(p, SPECIAL_VAR_SYMBOL);
1916 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1917 /* "$@" is special. Even if quoted, it can still
1918 * expand to nothing (not even an empty string) */
1919 if ((first_ch & 0x7f) != '@')
1920 ored_ch |= first_ch;
1923 switch (first_ch & 0x7f) {
1924 /* Highest bit in first_ch indicates that var is double-quoted */
1926 val = utoa(G.root_pid);
1928 case '!': /* bg pid */
1929 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1931 case '?': /* exitcode */
1932 val = utoa(G.last_exitcode);
1934 case '#': /* argc */
1935 if (arg[1] != SPECIAL_VAR_SYMBOL)
1936 /* actually, it's a ${#var} */
1938 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1943 if (!G.global_argv[i])
1945 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1946 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1947 smallint sv = output->o_escape;
1948 /* unquoted var's contents should be globbed, so don't escape */
1949 output->o_escape = 0;
1950 while (G.global_argv[i]) {
1951 n = expand_on_ifs(output, n, G.global_argv[i]);
1952 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1953 if (G.global_argv[i++][0] && G.global_argv[i]) {
1954 /* this argv[] is not empty and not last:
1955 * put terminating NUL, start new word */
1956 o_addchr(output, '\0');
1957 debug_print_list("expand_vars_to_list[2]", output, n);
1958 n = o_save_ptr(output, n);
1959 debug_print_list("expand_vars_to_list[3]", output, n);
1962 output->o_escape = sv;
1964 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1965 * and in this case should treat it like '$*' - see 'else...' below */
1966 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1968 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1969 if (++i >= G.global_argc)
1971 o_addchr(output, '\0');
1972 debug_print_list("expand_vars_to_list[4]", output, n);
1973 n = o_save_ptr(output, n);
1975 } else { /* quoted $*: add as one word */
1977 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1978 if (!G.global_argv[++i])
1981 o_addchr(output, G.ifs[0]);
1985 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1986 /* "Empty variable", used to make "" etc to not disappear */
1990 #if ENABLE_HUSH_TICK
1991 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1994 //TODO: can we just stuff it into "output" directly?
1995 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1996 process_command_subs(&subst_result, arg);
1997 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1998 val = subst_result.data;
2001 #if ENABLE_SH_MATH_SUPPORT
2002 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2003 arith_eval_hooks_t hooks;
2008 arg++; /* skip '+' */
2009 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2010 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2012 exp_str = expand_pseudo_dquoted(arg);
2013 hooks.lookupvar = get_local_var_value;
2014 hooks.setvar = arith_set_local_var;
2015 hooks.endofname = endofname;
2016 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2020 const char *msg = "error in arithmetic";
2023 msg = "exponent less than 0";
2026 msg = "divide by 0";
2029 msg = "expression recursion loop detected";
2034 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2035 sprintf(arith_buf, arith_t_fmt, res);
2040 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2042 bool exp_len = false;
2043 bool exp_null = false;
2045 char exp_save = exp_save; /* for compiler */
2046 char exp_op = exp_op; /* for compiler */
2047 char *exp_word = exp_word; /* for compiler */
2051 arg[0] = first_ch & 0x7f;
2053 /* prepare for expansions */
2054 if (var[0] == '#') {
2055 /* handle length expansion ${#var} */
2059 /* maybe handle parameter expansion */
2060 exp_off = strcspn(var, ":-=+?%#");
2064 exp_save = var[exp_off];
2065 exp_null = exp_save == ':';
2066 exp_word = var + exp_off;
2069 exp_op = *exp_word++;
2070 var[exp_off] = '\0';
2074 /* lookup the variable in question */
2075 if (isdigit(var[0])) {
2076 /* handle_dollar() should have vetted var for us */
2078 if (i < G.global_argc)
2079 val = G.global_argv[i];
2080 /* else val remains NULL: $N with too big N */
2082 val = get_local_var_value(var);
2084 /* handle any expansions */
2086 debug_printf_expand("expand: length of '%s' = ", val);
2087 val = utoa(val ? strlen(val) : 0);
2088 debug_printf_expand("%s\n", val);
2089 } else if (exp_off) {
2090 if (exp_op == '%' || exp_op == '#') {
2092 /* we need to do a pattern match */
2095 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2096 if (exp_op == *exp_word) /* ## or %% */
2098 val = dyn_val = xstrdup(val);
2099 loc = scan(dyn_val, exp_word, zero);
2106 /* we need to do an expansion */
2107 int exp_test = (!val || (exp_null && !val[0]));
2109 exp_test = !exp_test;
2110 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2111 exp_null ? "true" : "false", exp_test);
2113 if (exp_op == '?') {
2114 //TODO: how interactive bash aborts expansion mid-command?
2115 /* ${var?[error_msg_if_unset]} */
2116 /* ${var:?[error_msg_if_unset_or_null]} */
2117 /* mimic bash message */
2118 die_if_script("%s: %s",
2120 exp_word[0] ? exp_word : "parameter null or not set"
2126 if (exp_op == '=') {
2127 /* ${var=[word]} or ${var:=[word]} */
2128 if (isdigit(var[0]) || var[0] == '#') {
2129 /* mimic bash message */
2130 die_if_script("$%s: cannot assign in this way", var);
2133 char *new_var = xasprintf("%s=%s", var, val);
2134 set_local_var(new_var, -1, 0);
2140 var[exp_off] = exp_save;
2144 #if ENABLE_HUSH_TICK
2147 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2148 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2150 /* unquoted var's contents should be globbed, so don't escape */
2151 smallint sv = output->o_escape;
2152 output->o_escape = 0;
2153 n = expand_on_ifs(output, n, val);
2155 output->o_escape = sv;
2157 } else { /* quoted $VAR, val will be appended below */
2158 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2161 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2163 o_addQstr(output, val, strlen(val));
2167 /* Do the check to avoid writing to a const string */
2168 if (*p != SPECIAL_VAR_SYMBOL)
2169 *p = SPECIAL_VAR_SYMBOL;
2171 #if ENABLE_HUSH_TICK
2172 o_free(&subst_result);
2175 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2178 debug_print_list("expand_vars_to_list[a]", output, n);
2179 /* this part is literal, and it was already pre-quoted
2180 * if needed (much earlier), do not use o_addQstr here! */
2181 o_addstr_with_NUL(output, arg);
2182 debug_print_list("expand_vars_to_list[b]", output, n);
2183 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2184 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2187 /* allow to reuse list[n] later without re-growth */
2188 output->has_empty_slot = 1;
2190 o_addchr(output, '\0');
2195 static char **expand_variables(char **argv, int or_mask)
2200 o_string output = NULL_O_STRING;
2202 if (or_mask & 0x100) {
2203 output.o_escape = 1; /* protect against globbing for "$var" */
2204 /* (unquoted $var will temporarily switch it off) */
2211 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2214 debug_print_list("expand_variables", &output, n);
2216 /* output.data (malloced in one block) gets returned in "list" */
2217 list = o_finalize_list(&output, n);
2218 debug_print_strings("expand_variables[1]", list);
2222 static char **expand_strvec_to_strvec(char **argv)
2224 return expand_variables(argv, 0x100);
2227 /* Used for expansion of right hand of assignments */
2228 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2230 static char *expand_string_to_string(const char *str)
2232 char *argv[2], **list;
2234 argv[0] = (char*)str;
2236 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2238 if (!list[0] || list[1])
2239 bb_error_msg_and_die("BUG in varexp2");
2240 /* actually, just move string 2*sizeof(char*) bytes back */
2241 overlapping_strcpy((char*)list, list[0]);
2242 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2246 /* Used for "eval" builtin */
2247 static char* expand_strvec_to_string(char **argv)
2251 list = expand_variables(argv, 0x80);
2252 /* Convert all NULs to spaces */
2257 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2258 bb_error_msg_and_die("BUG in varexp3");
2259 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2263 overlapping_strcpy((char*)list, list[0]);
2264 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2268 static char **expand_assignments(char **argv, int count)
2272 /* Expand assignments into one string each */
2273 for (i = 0; i < count; i++) {
2274 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2282 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2284 static void reset_traps_to_defaults(void)
2292 for (sig = 0; sig < NSIG; sig++) {
2296 G.traps[sig] = NULL;
2297 /* There is no signal for 0 (EXIT) */
2300 /* there was a trap handler, we are removing it
2301 * (if sig has non-DFL handling,
2302 * we don't need to do anything) */
2303 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2305 sigdelset(&G.blocked_set, sig);
2309 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2314 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2315 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2317 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2318 char *heredoc_argv[4];
2319 struct variable *cur;
2320 #if ENABLE_HUSH_FUNCTIONS
2321 struct function *funcp;
2326 if (!g_argv0) { /* heredoc */
2327 argv = heredoc_argv;
2328 argv[0] = (char *) G.argv0_for_re_execing;
2329 argv[1] = (char *) "-<";
2330 argv[2] = (char *) s;
2332 pp = &argv[3]; /* used as pointer to empty environment */
2336 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2337 , (unsigned) G.root_pid
2338 , (unsigned) G.last_bg_pid
2339 , (unsigned) G.last_exitcode
2340 USE_HUSH_LOOPS(, G.depth_of_loop)
2342 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2343 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2346 for (cur = G.top_var; cur; cur = cur->next) {
2347 if (!cur->flg_export || cur->flg_read_only)
2350 #if ENABLE_HUSH_FUNCTIONS
2351 for (funcp = G.top_func; funcp; funcp = funcp->next)
2357 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2358 *pp++ = (char *) G.argv0_for_re_execing;
2360 for (cur = G.top_var; cur; cur = cur->next) {
2361 if (cur->varstr == hush_version_str)
2363 if (cur->flg_read_only) {
2364 *pp++ = (char *) "-R";
2365 *pp++ = cur->varstr;
2366 } else if (!cur->flg_export) {
2367 *pp++ = (char *) "-V";
2368 *pp++ = cur->varstr;
2371 #if ENABLE_HUSH_FUNCTIONS
2372 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2373 *pp++ = (char *) "-F";
2374 *pp++ = funcp->name;
2375 *pp++ = funcp->body_as_string;
2378 /* We can pass activated traps here. Say, -Tnn:trap_string
2380 * However, POSIX says that subshells reset signals with traps
2382 * I tested bash-3.2 and it not only does that with true subshells
2383 * of the form ( list ), but with any forked children shells.
2384 * I set trap "echo W" WINCH; and then tried:
2386 * { echo 1; sleep 20; echo 2; } &
2387 * while true; do echo 1; sleep 20; echo 2; break; done &
2388 * true | { echo 1; sleep 20; echo 2; } | cat
2390 * In all these cases sending SIGWINCH to the child shell
2391 * did not run the trap. If I add trap "echo V" WINCH;
2392 * _inside_ group (just before echo 1), it works.
2394 * I conclude it means we don't need to pass active traps here.
2395 * exec syscall below resets them to SIG_DFL for us.
2397 *pp++ = (char *) "-c";
2402 /* *pp = NULL; - is already there */
2406 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2407 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2408 execve(bb_busybox_exec_path, argv, pp);
2409 /* Fallback. Useful for init=/bin/hush usage etc */
2410 if (argv[0][0] == '/')
2411 execve(argv[0], argv, pp);
2412 xfunc_error_retval = 127;
2413 bb_error_msg_and_die("can't re-execute the shell");
2415 #endif /* !BB_MMU */
2418 static void setup_heredoc(struct redir_struct *redir)
2420 struct fd_pair pair;
2423 /* the _body_ of heredoc (misleading field name) */
2424 const char *heredoc = redir->rd_filename;
2431 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2432 expanded = expand_pseudo_dquoted(heredoc);
2436 len = strlen(heredoc);
2438 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2440 xmove_fd(pair.rd, redir->rd_fd);
2442 /* Try writing without forking. Newer kernels have
2443 * dynamically growing pipes. Must use non-blocking write! */
2446 written = write(pair.wr, heredoc, len);
2457 ndelay_off(pair.wr);
2459 /* Okay, pipe buffer was not big enough */
2460 /* Note: we must not create a stray child (bastard? :)
2461 * for the unsuspecting parent process. Child creates a grandchild
2462 * and exits before parent execs the process which consumes heredoc
2463 * (that exec happens after we return from this function) */
2466 bb_perror_msg_and_die("vfork");
2469 pid = BB_MMU ? fork() : vfork();
2471 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2475 close(redir->rd_fd); /* read side of the pipe */
2477 full_write(pair.wr, heredoc, len); /* may loop or block */
2480 /* Delegate blocking writes to another process */
2481 disable_restore_tty_pgrp_on_exit();
2482 xmove_fd(pair.wr, STDOUT_FILENO);
2483 re_execute_shell(&to_free, heredoc, NULL, NULL);
2487 enable_restore_tty_pgrp_on_exit();
2493 wait(NULL); /* wait till child has died */
2496 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2497 * and stderr if they are redirected. */
2498 static int setup_redirects(struct command *prog, int squirrel[])
2501 struct redir_struct *redir;
2503 for (redir = prog->redirects; redir; redir = redir->next) {
2504 if (redir->rd_type == REDIRECT_HEREDOC2) {
2505 /* rd_fd<<HERE case */
2506 if (squirrel && redir->rd_fd < 3) {
2507 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2509 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2511 debug_printf_parse("set heredoc '%s'\n",
2512 redir->rd_filename);
2513 setup_heredoc(redir);
2517 if (redir->rd_dup == REDIRFD_TO_FILE) {
2518 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2520 if (redir->rd_filename == NULL) {
2521 /* Something went wrong in the parse.
2522 * Pretend it didn't happen */
2523 bb_error_msg("bug in redirect parse");
2526 mode = redir_table[redir->rd_type].mode;
2527 p = expand_string_to_string(redir->rd_filename);
2528 openfd = open_or_warn(p, mode);
2531 /* this could get lost if stderr has been redirected, but
2532 * bash and ash both lose it as well (though zsh doesn't!) */
2533 //what the above comment tries to say?
2537 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2538 openfd = redir->rd_dup;
2541 if (openfd != redir->rd_fd) {
2542 if (squirrel && redir->rd_fd < 3) {
2543 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2545 if (openfd == REDIRFD_CLOSE) {
2546 /* "n>-" means "close me" */
2547 close(redir->rd_fd);
2549 xdup2(openfd, redir->rd_fd);
2550 if (redir->rd_dup == REDIRFD_TO_FILE)
2558 static void restore_redirects(int squirrel[])
2561 for (i = 0; i < 3; i++) {
2564 /* We simply die on error */
2571 static void free_pipe_list(struct pipe *head);
2573 /* Return code is the exit status of the pipe */
2574 static void free_pipe(struct pipe *pi)
2577 struct command *command;
2578 struct redir_struct *r, *rnext;
2581 if (pi->stopped_cmds > 0) /* why? */
2583 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2584 for (i = 0; i < pi->num_cmds; i++) {
2585 command = &pi->cmds[i];
2586 debug_printf_clean(" command %d:\n", i);
2587 if (command->argv) {
2588 for (a = 0, p = command->argv; *p; a++, p++) {
2589 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2591 free_strings(command->argv);
2592 command->argv = NULL;
2594 /* not "else if": on syntax error, we may have both! */
2595 if (command->group) {
2596 debug_printf_clean(" begin group (grp_type:%d)\n",
2598 free_pipe_list(command->group);
2599 debug_printf_clean(" end group\n");
2600 command->group = NULL;
2602 /* else is crucial here.
2603 * If group != NULL, child_func is meaningless */
2604 #if ENABLE_HUSH_FUNCTIONS
2605 else if (command->child_func) {
2606 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2607 command->child_func->parent_cmd = NULL;
2611 free(command->group_as_string);
2612 command->group_as_string = NULL;
2614 for (r = command->redirects; r; r = rnext) {
2615 debug_printf_clean(" redirect %d%s",
2616 r->rd_fd, redir_table[r->rd_type].descrip);
2617 /* guard against the case >$FOO, where foo is unset or blank */
2618 if (r->rd_filename) {
2619 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2620 free(r->rd_filename);
2621 r->rd_filename = NULL;
2623 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2627 command->redirects = NULL;
2629 free(pi->cmds); /* children are an array, they get freed all at once */
2637 static void free_pipe_list(struct pipe *head)
2639 struct pipe *pi, *next;
2641 for (pi = head; pi; pi = next) {
2643 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2646 debug_printf_clean("pipe followup code %d\n", pi->followup);
2648 /*pi->next = NULL;*/
2654 static int run_list(struct pipe *pi);
2656 #define parse_stream(pstring, input, end_trigger) \
2657 parse_stream(input, end_trigger)
2659 static struct pipe *parse_stream(char **pstring,
2660 struct in_str *input,
2662 static void parse_and_run_string(const char *s);
2665 static const struct built_in_command* find_builtin(const char *name)
2667 const struct built_in_command *x;
2668 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2669 if (strcmp(name, x->cmd) != 0)
2671 debug_printf_exec("found builtin '%s'\n", name);
2677 #if ENABLE_HUSH_FUNCTIONS
2678 static const struct function *find_function(const char *name)
2680 const struct function *funcp = G.top_func;
2682 if (strcmp(name, funcp->name) == 0) {
2685 funcp = funcp->next;
2687 debug_printf_exec("found function '%s'\n", name);
2691 /* Note: takes ownership on name ptr */
2692 static struct function *new_function(char *name)
2694 struct function *funcp;
2695 struct function **funcpp = &G.top_func;
2697 while ((funcp = *funcpp) != NULL) {
2698 struct command *cmd;
2700 if (strcmp(funcp->name, name) != 0) {
2701 funcpp = &funcp->next;
2705 cmd = funcp->parent_cmd;
2706 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2708 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2710 /* Note: if !funcp->body, do not free body_as_string!
2711 * This is a special case of "-F name body" function:
2712 * body_as_string was not malloced! */
2714 free_pipe_list(funcp->body);
2716 free(funcp->body_as_string);
2720 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2721 cmd->argv[0] = funcp->name;
2722 cmd->group = funcp->body;
2724 cmd->group_as_string = funcp->body_as_string;
2729 debug_printf_exec("remembering new function '%s'\n", command->argv[0]);
2730 funcp = *funcpp = xzalloc(sizeof(*funcp));
2731 /*funcp->next = NULL;*/
2738 #define exec_function(nommu_save, funcp, argv) \
2739 exec_function(funcp, argv)
2741 static void exec_function(nommu_save_t *nommu_save,
2742 const struct function *funcp,
2743 char **argv) NORETURN;
2744 static void exec_function(nommu_save_t *nommu_save,
2745 const struct function *funcp,
2751 argv[0] = G.global_argv[0];
2752 G.global_argv = argv;
2756 /* On MMU, funcp->body is always non-NULL */
2757 n = run_list(funcp->body);
2761 re_execute_shell(&nommu_save->argv_from_re_execing,
2762 funcp->body_as_string,
2768 static int run_function(const struct function *funcp, char **argv)
2773 smallint sv_g_malloced;
2778 sv_g_malloced = G.global_args_malloced;
2779 sv_g_argc = G.global_argc;
2780 sv_g_argv = G.global_argv;
2787 argv[0] = G.global_argv[0]; /* retain $0 */
2788 G.global_args_malloced = 0;
2790 G.global_argv = argv;
2792 /* On MMU, funcp->body is always non-NULL */
2795 /* Function defined by -F */
2796 parse_and_run_string(funcp->body_as_string);
2797 n = G.last_exitcode;
2801 n = run_list(funcp->body);
2804 if (G.global_args_malloced) {
2805 /* function ran "set -- arg1 arg2 ..." */
2809 free(G.global_argv);
2813 G.global_args_malloced = sv_g_malloced;
2814 G.global_argc = sv_g_argc;
2815 G.global_argv = sv_g_argv;
2823 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2824 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2825 #define pseudo_exec(nommu_save, command, argv_expanded) \
2826 pseudo_exec(command, argv_expanded)
2829 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2831 * XXX no exit() here. If you don't exec, use _exit instead.
2832 * The at_exit handlers apparently confuse the calling process,
2833 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2834 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2835 char **argv, int assignment_cnt,
2836 char **argv_expanded) NORETURN;
2837 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2838 char **argv, int assignment_cnt,
2839 char **argv_expanded)
2843 /* Case when we are here: ... | var=val | ... */
2844 if (!argv[assignment_cnt])
2845 _exit(EXIT_SUCCESS);
2847 new_env = expand_assignments(argv, assignment_cnt);
2849 putenv_all(new_env);
2850 free(new_env); /* optional */
2852 nommu_save->new_env = new_env;
2853 nommu_save->old_env = putenv_all_and_save_old(new_env);
2855 if (argv_expanded) {
2856 argv = argv_expanded;
2858 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2860 nommu_save->argv = argv;
2864 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2865 if (strchr(argv[0], '/') != NULL)
2869 /* On NOMMU, we must never block!
2870 * Example: { sleep 99999 | read line } & echo Ok
2871 * read builtin will block on read syscall, leaving parent blocked
2872 * in vfork. Therefore we can't do this:
2875 /* Check if the command matches any of the builtins.
2876 * Depending on context, this might be redundant. But it's
2877 * easier to waste a few CPU cycles than it is to figure out
2878 * if this is one of those cases.
2882 const struct built_in_command *x = find_builtin(argv[0]);
2884 rcode = x->function(argv);
2890 #if ENABLE_HUSH_FUNCTIONS
2891 /* Check if the command matches any functions */
2893 const struct function *funcp = find_function(argv[0]);
2895 exec_function(nommu_save, funcp, argv);
2900 #if ENABLE_FEATURE_SH_STANDALONE
2901 /* Check if the command matches any busybox applets */
2903 int a = find_applet_by_name(argv[0]);
2905 # if BB_MMU /* see above why on NOMMU it is not allowed */
2906 if (APPLET_IS_NOEXEC(a)) {
2907 debug_printf_exec("running applet '%s'\n", argv[0]);
2908 run_applet_no_and_exit(a, argv);
2911 /* Re-exec ourselves */
2912 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2913 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2914 execv(bb_busybox_exec_path, argv);
2915 /* If they called chroot or otherwise made the binary no longer
2916 * executable, fall through */
2921 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2924 debug_printf_exec("execing '%s'\n", argv[0]);
2925 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2926 execvp(argv[0], argv);
2927 bb_perror_msg("can't exec '%s'", argv[0]);
2928 _exit(EXIT_FAILURE);
2931 /* Called after [v]fork() in run_pipe
2933 static void pseudo_exec(nommu_save_t *nommu_save,
2934 struct command *command,
2935 char **argv_expanded) NORETURN;
2936 static void pseudo_exec(nommu_save_t *nommu_save,
2937 struct command *command,
2938 char **argv_expanded)
2940 if (command->argv) {
2941 pseudo_exec_argv(nommu_save, command->argv,
2942 command->assignment_cnt, argv_expanded);
2945 if (command->group) {
2946 /* Cases when we are here:
2949 * ... | ( list ) | ...
2950 * ... | { list } | ...
2954 debug_printf_exec("pseudo_exec: run_list\n");
2955 reset_traps_to_defaults();
2956 rcode = run_list(command->group);
2957 /* OK to leak memory by not calling free_pipe_list,
2958 * since this process is about to exit */
2961 re_execute_shell(&nommu_save->argv_from_re_execing,
2962 command->group_as_string,
2968 /* Case when we are here: ... | >file */
2969 debug_printf_exec("pseudo_exec'ed null command\n");
2970 _exit(EXIT_SUCCESS);
2974 static const char *get_cmdtext(struct pipe *pi)
2980 /* This is subtle. ->cmdtext is created only on first backgrounding.
2981 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2982 * On subsequent bg argv is trashed, but we won't use it */
2985 argv = pi->cmds[0].argv;
2986 if (!argv || !argv[0]) {
2987 pi->cmdtext = xzalloc(1);
2992 do len += strlen(*argv) + 1; while (*++argv);
2993 pi->cmdtext = p = xmalloc(len);
2994 argv = pi->cmds[0].argv;
2996 len = strlen(*argv);
2997 memcpy(p, *argv, len);
3005 static void insert_bg_job(struct pipe *pi)
3007 struct pipe *thejob;
3010 /* Linear search for the ID of the job to use */
3012 for (thejob = G.job_list; thejob; thejob = thejob->next)
3013 if (thejob->jobid >= pi->jobid)
3014 pi->jobid = thejob->jobid + 1;
3016 /* Add thejob to the list of running jobs */
3018 thejob = G.job_list = xmalloc(sizeof(*thejob));
3020 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
3022 thejob->next = xmalloc(sizeof(*thejob));
3023 thejob = thejob->next;
3026 /* Physically copy the struct job */
3027 memcpy(thejob, pi, sizeof(struct pipe));
3028 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3029 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
3030 for (i = 0; i < pi->num_cmds; i++) {
3031 // TODO: do we really need to have so many fields which are just dead weight
3032 // at execution stage?
3033 thejob->cmds[i].pid = pi->cmds[i].pid;
3034 /* all other fields are not used and stay zero */
3036 thejob->next = NULL;
3037 thejob->cmdtext = xstrdup(get_cmdtext(pi));
3039 /* We don't wait for background thejobs to return -- append it
3040 to the list of backgrounded thejobs and leave it alone */
3041 if (G_interactive_fd)
3042 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
3043 G.last_bg_pid = thejob->cmds[0].pid;
3044 G.last_jobid = thejob->jobid;
3047 static void remove_bg_job(struct pipe *pi)
3049 struct pipe *prev_pipe;
3051 if (pi == G.job_list) {
3052 G.job_list = pi->next;
3054 prev_pipe = G.job_list;
3055 while (prev_pipe->next != pi)
3056 prev_pipe = prev_pipe->next;
3057 prev_pipe->next = pi->next;
3060 G.last_jobid = G.job_list->jobid;
3065 /* Remove a backgrounded job */
3066 static void delete_finished_bg_job(struct pipe *pi)
3069 pi->stopped_cmds = 0;
3075 /* Check to see if any processes have exited -- if they
3076 * have, figure out why and see if a job has completed */
3077 static int checkjobs(struct pipe* fg_pipe)
3087 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3090 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3091 // /* avoid doing syscall, nothing there anyway */
3094 attributes = WUNTRACED;
3095 if (fg_pipe == NULL)
3096 attributes |= WNOHANG;
3098 /* Do we do this right?
3099 * bash-3.00# sleep 20 | false
3101 * [3]+ Stopped sleep 20 | false
3102 * bash-3.00# echo $?
3103 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3106 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
3107 //are stopped. Testcase: "cat | cat" in a script (not on command line)
3108 // + killall -STOP cat
3115 // i = G.count_SIGCHLD;
3116 childpid = waitpid(-1, &status, attributes);
3117 if (childpid <= 0) {
3118 if (childpid && errno != ECHILD)
3119 bb_perror_msg("waitpid");
3120 // else /* Until next SIGCHLD, waitpid's are useless */
3121 // G.handled_SIGCHLD = i;
3124 dead = WIFEXITED(status) || WIFSIGNALED(status);
3127 if (WIFSTOPPED(status))
3128 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3129 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3130 if (WIFSIGNALED(status))
3131 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3132 childpid, WTERMSIG(status), WEXITSTATUS(status));
3133 if (WIFEXITED(status))
3134 debug_printf_jobs("pid %d exited, exitcode %d\n",
3135 childpid, WEXITSTATUS(status));
3137 /* Were we asked to wait for fg pipe? */
3139 for (i = 0; i < fg_pipe->num_cmds; i++) {
3140 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3141 if (fg_pipe->cmds[i].pid != childpid)
3143 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
3145 fg_pipe->cmds[i].pid = 0;
3146 fg_pipe->alive_cmds--;
3147 if (i == fg_pipe->num_cmds - 1) {
3148 /* last process gives overall exitstatus */
3149 rcode = WEXITSTATUS(status);
3150 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3153 fg_pipe->cmds[i].is_stopped = 1;
3154 fg_pipe->stopped_cmds++;
3156 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3157 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3158 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3159 /* All processes in fg pipe have exited/stopped */
3161 if (fg_pipe->alive_cmds)
3162 insert_bg_job(fg_pipe);
3166 /* There are still running processes in the fg pipe */
3167 goto wait_more; /* do waitpid again */
3169 /* it wasnt fg_pipe, look for process in bg pipes */
3173 /* We asked to wait for bg or orphaned children */
3174 /* No need to remember exitcode in this case */
3175 for (pi = G.job_list; pi; pi = pi->next) {
3176 for (i = 0; i < pi->num_cmds; i++) {
3177 if (pi->cmds[i].pid == childpid)
3178 goto found_pi_and_prognum;
3181 /* Happens when shell is used as init process (init=/bin/sh) */
3182 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3183 continue; /* do waitpid again */
3185 found_pi_and_prognum:
3188 pi->cmds[i].pid = 0;
3190 if (!pi->alive_cmds) {
3191 if (G_interactive_fd)
3192 printf(JOB_STATUS_FORMAT, pi->jobid,
3193 "Done", pi->cmdtext);
3194 delete_finished_bg_job(pi);
3198 pi->cmds[i].is_stopped = 1;
3202 } /* while (waitpid succeeds)... */
3208 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3211 int rcode = checkjobs(fg_pipe);
3212 /* Job finished, move the shell to the foreground */
3213 p = getpgid(0); /* pgid of our process */
3214 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3215 tcsetpgrp(G_interactive_fd, p);
3220 /* Start all the jobs, but don't wait for anything to finish.
3223 * Return code is normally -1, when the caller has to wait for children
3224 * to finish to determine the exit status of the pipe. If the pipe
3225 * is a simple builtin command, however, the action is done by the
3226 * time run_pipe returns, and the exit code is provided as the
3229 * Returns -1 only if started some children. IOW: we have to
3230 * mask out retvals of builtins etc with 0xff!
3232 * The only case when we do not need to [v]fork is when the pipe
3233 * is single, non-backgrounded, non-subshell command. Examples:
3234 * cmd ; ... { list } ; ...
3235 * cmd && ... { list } && ...
3236 * cmd || ... { list } || ...
3237 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3238 * or (if SH_STANDALONE) an applet, and we can run the { list }
3239 * with run_list(). If it isn't one of these, we fork and exec cmd.
3241 * Cases when we must fork:
3242 * non-single: cmd | cmd
3243 * backgrounded: cmd & { list } &
3244 * subshell: ( list ) [&]
3246 static int run_pipe(struct pipe *pi)
3248 static const char *const null_ptr = NULL;
3251 int pipefds[2]; /* pipefds[0] is for reading */
3252 struct command *command;
3253 char **argv_expanded;
3256 /* it is not always needed, but we aim to smaller code */
3257 int squirrel[] = { -1, -1, -1 };
3260 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3263 USE_HUSH_JOB(pi->pgrp = -1;)
3264 pi->stopped_cmds = 0;
3265 command = &(pi->cmds[0]);
3266 argv_expanded = NULL;
3268 if (pi->num_cmds != 1
3269 || pi->followup == PIPE_BG
3270 || command->grp_type == GRP_SUBSHELL
3277 debug_printf_exec(": group:%p argv:'%s'\n",
3278 command->group, command->argv ? command->argv[0] : "NONE");
3280 if (command->group) {
3281 #if ENABLE_HUSH_FUNCTIONS
3282 if (command->grp_type == GRP_FUNCTION) {
3283 /* "executing" func () { list } */
3284 struct function *funcp;
3286 funcp = new_function(command->argv[0]);
3287 /* funcp->name is already set to argv[0] */
3288 funcp->body = command->group;
3290 funcp->body_as_string = command->group_as_string;
3291 command->group_as_string = NULL;
3293 command->group = NULL;
3294 command->argv[0] = NULL;
3295 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3296 funcp->parent_cmd = command;
3297 command->child_func = funcp;
3299 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3301 return EXIT_SUCCESS;
3305 debug_printf("non-subshell group\n");
3306 rcode = 1; /* exitcode if redir failed */
3307 if (setup_redirects(command, squirrel) == 0) {
3308 debug_printf_exec(": run_list\n");
3309 rcode = run_list(command->group) & 0xff;
3311 restore_redirects(squirrel);
3312 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3314 debug_printf_exec("run_pipe: return %d\n", rcode);
3318 argv = command->argv ? command->argv : (char **) &null_ptr;
3320 const struct built_in_command *x;
3321 #if ENABLE_HUSH_FUNCTIONS
3322 const struct function *funcp;
3326 char **new_env = NULL;
3327 char **old_env = NULL;
3329 if (argv[command->assignment_cnt] == NULL) {
3330 /* Assignments, but no command */
3331 /* Ensure redirects take effect. Try "a=t >file" */
3332 rcode = setup_redirects(command, squirrel);
3333 restore_redirects(squirrel);
3334 /* Set shell variables */
3336 p = expand_string_to_string(*argv);
3337 debug_printf_exec("set shell var:'%s'->'%s'\n",
3339 set_local_var(p, 0, 0);
3342 /* Do we need to flag set_local_var() errors?
3343 * "assignment to readonly var" and "putenv error"
3345 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3347 debug_printf_exec("run_pipe: return %d\n", rcode);
3351 /* Expand the rest into (possibly) many strings each */
3352 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3354 x = find_builtin(argv_expanded[0]);
3355 #if ENABLE_HUSH_FUNCTIONS
3358 funcp = find_function(argv_expanded[0]);
3362 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3363 debug_printf("exec with redirects only\n");
3364 rcode = setup_redirects(command, NULL);
3365 goto clean_up_and_ret1;
3368 /* XXX setup_redirects acts on file descriptors, not FILEs.
3369 * This is perfect for work that comes after exec().
3370 * Is it really safe for inline use? Experimentally,
3371 * things seem to work with glibc. */
3372 rcode = setup_redirects(command, squirrel);
3374 new_env = expand_assignments(argv, command->assignment_cnt);
3375 old_env = putenv_all_and_save_old(new_env);
3377 debug_printf_exec(": builtin '%s' '%s'...\n",
3378 x->cmd, argv_expanded[1]);
3379 rcode = x->function(argv_expanded) & 0xff;
3381 #if ENABLE_HUSH_FUNCTIONS
3383 debug_printf_exec(": function '%s' '%s'...\n",
3384 funcp->name, argv_expanded[1]);
3385 rcode = run_function(funcp, argv_expanded) & 0xff;
3389 #if ENABLE_FEATURE_SH_STANDALONE
3392 restore_redirects(squirrel);
3393 free_strings_and_unsetenv(new_env, 1);
3394 putenv_all(old_env);
3395 /* Free the pointers, but the strings themselves
3396 * are in environ now, don't use free_strings! */
3399 free(argv_expanded);
3400 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3402 debug_printf_exec("run_pipe return %d\n", rcode);
3406 #if ENABLE_FEATURE_SH_STANDALONE
3407 i = find_applet_by_name(argv_expanded[0]);
3408 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3409 rcode = setup_redirects(command, squirrel);
3411 save_nofork_data(&G.nofork_save);
3412 new_env = expand_assignments(argv, command->assignment_cnt);
3413 old_env = putenv_all_and_save_old(new_env);
3414 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3415 argv_expanded[0], argv_expanded[1]);
3416 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3418 goto clean_up_and_ret;
3421 /* It is neither builtin nor applet. We must fork. */
3425 /* NB: argv_expanded may already be created, and that
3426 * might include `cmd` runs! Do not rerun it! We *must*
3427 * use argv_expanded if it's non-NULL */
3429 /* Going to fork a child per each pipe member */
3433 for (i = 0; i < pi->num_cmds; i++) {
3435 volatile nommu_save_t nommu_save;
3436 nommu_save.new_env = NULL;
3437 nommu_save.old_env = NULL;
3438 nommu_save.argv = NULL;
3439 nommu_save.argv_from_re_execing = NULL;
3441 command = &(pi->cmds[i]);
3442 if (command->argv) {
3443 debug_printf_exec(": pipe member '%s' '%s'...\n",
3444 command->argv[0], command->argv[1]);
3446 debug_printf_exec(": pipe member with no argv\n");
3449 /* pipes are inserted between pairs of commands */
3452 if ((i + 1) < pi->num_cmds)
3455 command->pid = BB_MMU ? fork() : vfork();
3456 if (!command->pid) { /* child */
3458 disable_restore_tty_pgrp_on_exit();
3460 /* Every child adds itself to new process group
3461 * with pgid == pid_of_first_child_in_pipe */
3462 if (G.run_list_level == 1 && G_interactive_fd) {
3465 if (pgrp < 0) /* true for 1st process only */
3467 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3468 /* We do it in *every* child, not just first,
3470 tcsetpgrp(G_interactive_fd, pgrp);
3474 xmove_fd(nextin, 0);
3475 xmove_fd(pipefds[1], 1); /* write end */
3477 close(pipefds[0]); /* read end */
3478 /* Like bash, explicit redirects override pipes,
3479 * and the pipe fd is available for dup'ing. */
3480 if (setup_redirects(command, NULL))
3483 /* Restore default handlers just prior to exec */
3484 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3486 /* Stores to nommu_save list of env vars putenv'ed
3487 * (NOMMU, on MMU we don't need that) */
3488 /* cast away volatility... */
3489 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3490 /* pseudo_exec() does not return */
3493 /* parent or error */
3494 enable_restore_tty_pgrp_on_exit();
3496 /* Clean up after vforked child */
3497 free(nommu_save.argv);
3498 free(nommu_save.argv_from_re_execing);
3499 free_strings_and_unsetenv(nommu_save.new_env, 1);
3500 putenv_all(nommu_save.old_env);
3501 /* Free the pointers, but the strings themselves
3502 * are in environ now, don't use free_strings! */
3503 free(nommu_save.old_env);
3505 free(argv_expanded);
3506 argv_expanded = NULL;
3507 if (command->pid < 0) { /* [v]fork failed */
3508 /* Clearly indicate, was it fork or vfork */
3509 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3513 /* Second and next children need to know pid of first one */
3515 pi->pgrp = command->pid;
3521 if ((i + 1) < pi->num_cmds)
3522 close(pipefds[1]); /* write end */
3523 /* Pass read (output) pipe end to next iteration */
3524 nextin = pipefds[0];
3527 if (!pi->alive_cmds) {
3529 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3534 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3538 #ifndef debug_print_tree
3539 static void debug_print_tree(struct pipe *pi, int lvl)
3541 static const char *const PIPE[] = {
3547 static const char *RES[] = {
3548 [RES_NONE ] = "NONE" ,
3551 [RES_THEN ] = "THEN" ,
3552 [RES_ELIF ] = "ELIF" ,
3553 [RES_ELSE ] = "ELSE" ,
3556 #if ENABLE_HUSH_LOOPS
3557 [RES_FOR ] = "FOR" ,
3558 [RES_WHILE] = "WHILE",
3559 [RES_UNTIL] = "UNTIL",
3561 [RES_DONE ] = "DONE" ,
3563 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3566 #if ENABLE_HUSH_CASE
3567 [RES_CASE ] = "CASE" ,
3568 [RES_MATCH] = "MATCH",
3569 [RES_CASEI] = "CASEI",
3570 [RES_ESAC ] = "ESAC" ,
3572 [RES_XXXX ] = "XXXX" ,
3573 [RES_SNTX ] = "SNTX" ,
3575 static const char *const GRPTYPE[] = {
3578 #if ENABLE_HUSH_FUNCTIONS
3587 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3588 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3590 while (prn < pi->num_cmds) {
3591 struct command *command = &pi->cmds[prn];
3592 char **argv = command->argv;
3594 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3596 command->assignment_cnt);
3597 if (command->group) {
3598 fprintf(stderr, " group %s: (argv=%p)\n",
3599 GRPTYPE[command->grp_type],
3601 debug_print_tree(command->group, lvl+1);
3605 if (argv) while (*argv) {
3606 fprintf(stderr, " '%s'", *argv);
3609 fprintf(stderr, "\n");
3618 /* NB: called by pseudo_exec, and therefore must not modify any
3619 * global data until exec/_exit (we can be a child after vfork!) */
3620 static int run_list(struct pipe *pi)
3622 #if ENABLE_HUSH_CASE
3623 char *case_word = NULL;
3625 #if ENABLE_HUSH_LOOPS
3626 struct pipe *loop_top = NULL;
3627 char *for_varname = NULL;
3628 char **for_lcur = NULL;
3629 char **for_list = NULL;
3631 smallint last_followup;
3633 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3634 smalluint cond_code = 0;
3636 enum { cond_code = 0 };
3639 smallint rword; /* enum reserved_style */
3640 smallint last_rword; /* ditto */
3643 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3646 #if ENABLE_HUSH_LOOPS
3647 /* Check syntax for "for" */
3648 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3649 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3651 /* current word is FOR or IN (BOLD in comments below) */
3652 if (cpipe->next == NULL) {
3653 syntax_error("malformed for");
3655 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3658 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3659 if (cpipe->next->res_word == RES_DO)
3661 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3662 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3663 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3665 syntax_error("malformed for");
3667 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3673 /* Past this point, all code paths should jump to ret: label
3674 * in order to return, no direct "return" statements please.
3675 * This helps to ensure that no memory is leaked. */
3677 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3680 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3681 * We are saving state before entering outermost list ("while...done")
3682 * so that ctrl-Z will correctly background _entire_ outermost list,
3683 * not just a part of it (like "sleep 1 | exit 2") */
3684 if (++G.run_list_level == 1 && G_interactive_fd) {
3685 if (sigsetjmp(G.toplevel_jb, 1)) {
3686 /* ctrl-Z forked and we are parent; or ctrl-C.
3687 * Sighandler has longjmped us here */
3688 signal(SIGINT, SIG_IGN);
3689 signal(SIGTSTP, SIG_IGN);
3690 /* Restore level (we can be coming from deep inside
3692 G.run_list_level = 1;
3693 #if ENABLE_FEATURE_SH_STANDALONE
3694 if (G.nofork_save.saved) { /* if save area is valid */
3695 debug_printf_jobs("exiting nofork early\n");
3696 restore_nofork_data(&G.nofork_save);
3699 //// if (G.ctrl_z_flag) {
3700 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3701 //// * Remember this child as background job */
3702 //// insert_bg_job(pi);
3704 /* ctrl-C. We just stop doing whatever we were doing */
3707 USE_HUSH_LOOPS(loop_top = NULL;)
3708 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3712 //// /* ctrl-Z handler will store pid etc in pi */
3713 //// G.toplevel_list = pi;
3714 //// G.ctrl_z_flag = 0;
3715 #if ENABLE_FEATURE_SH_STANDALONE
3716 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3718 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3719 //// signal(SIGINT, handler_ctrl_c);
3725 last_rword = RES_XXXX;
3727 last_followup = PIPE_SEQ;
3728 rcode = G.last_exitcode;
3730 /* Go through list of pipes, (maybe) executing them. */
3731 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3735 IF_HAS_KEYWORDS(rword = pi->res_word;)
3736 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3737 rword, cond_code, last_rword);
3738 #if ENABLE_HUSH_LOOPS
3739 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3740 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3742 /* start of a loop: remember where loop starts */
3747 /* Still in the same "if...", "then..." or "do..." branch? */
3748 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3749 if ((rcode == 0 && last_followup == PIPE_OR)
3750 || (rcode != 0 && last_followup == PIPE_AND)
3752 /* It is "<true> || CMD" or "<false> && CMD"
3753 * and we should not execute CMD */
3754 debug_printf_exec("skipped cmd because of || or &&\n");
3755 last_followup = pi->followup;
3759 last_followup = pi->followup;
3760 IF_HAS_KEYWORDS(last_rword = rword;)
3763 if (rword == RES_THEN) {
3764 /* if false; then ... fi has exitcode 0! */
3765 G.last_exitcode = rcode = EXIT_SUCCESS;
3766 /* "if <false> THEN cmd": skip cmd */
3770 if (rword == RES_ELSE || rword == RES_ELIF) {
3771 /* "if <true> then ... ELSE/ELIF cmd":
3772 * skip cmd and all following ones */
3777 #if ENABLE_HUSH_LOOPS
3778 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3780 /* first loop through for */
3782 static const char encoded_dollar_at[] ALIGN1 = {
3783 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3784 }; /* encoded representation of "$@" */
3785 static const char *const encoded_dollar_at_argv[] = {
3786 encoded_dollar_at, NULL
3787 }; /* argv list with one element: "$@" */
3790 vals = (char**)encoded_dollar_at_argv;
3791 if (pi->next->res_word == RES_IN) {
3792 /* if no variable values after "in" we skip "for" */
3793 if (!pi->next->cmds[0].argv) {
3794 G.last_exitcode = rcode = EXIT_SUCCESS;
3795 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3798 vals = pi->next->cmds[0].argv;
3799 } /* else: "for var; do..." -> assume "$@" list */
3800 /* create list of variable values */
3801 debug_print_strings("for_list made from", vals);
3802 for_list = expand_strvec_to_strvec(vals);
3803 for_lcur = for_list;
3804 debug_print_strings("for_list", for_list);
3805 for_varname = pi->cmds[0].argv[0];
3806 pi->cmds[0].argv[0] = NULL;
3808 free(pi->cmds[0].argv[0]);
3810 /* "for" loop is over, clean up */
3814 pi->cmds[0].argv[0] = for_varname;
3817 /* Insert next value from for_lcur */
3818 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3819 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3820 pi->cmds[0].assignment_cnt = 1;
3822 if (rword == RES_IN) {
3823 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3825 if (rword == RES_DONE) {
3826 continue; /* "done" has no cmds too */
3829 #if ENABLE_HUSH_CASE
3830 if (rword == RES_CASE) {
3831 case_word = expand_strvec_to_string(pi->cmds->argv);
3834 if (rword == RES_MATCH) {
3837 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3839 /* all prev words didn't match, does this one match? */
3840 argv = pi->cmds->argv;
3842 char *pattern = expand_string_to_string(*argv);
3843 /* TODO: which FNM_xxx flags to use? */
3844 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3846 if (cond_code == 0) { /* match! we will execute this branch */
3847 free(case_word); /* make future "word)" stop */
3855 if (rword == RES_CASEI) { /* inside of a case branch */
3857 continue; /* not matched yet, skip this pipe */
3860 /* Just pressing <enter> in shell should check for jobs.
3861 * OTOH, in non-interactive shell this is useless
3862 * and only leads to extra job checks */
3863 if (pi->num_cmds == 0) {
3864 if (G_interactive_fd)
3865 goto check_jobs_and_continue;
3869 /* After analyzing all keywords and conditions, we decided
3870 * to execute this pipe. NB: have to do checkjobs(NULL)
3871 * after run_pipe to collect any background children,
3872 * even if list execution is to be stopped. */
3873 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3876 #if ENABLE_HUSH_LOOPS
3877 G.flag_break_continue = 0;
3879 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3881 /* We only ran a builtin: rcode is already known
3882 * and we don't need to wait for anything. */
3883 G.last_exitcode = rcode;
3884 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3885 check_and_run_traps(0);
3886 #if ENABLE_HUSH_LOOPS
3887 /* Was it "break" or "continue"? */
3888 if (G.flag_break_continue) {
3889 smallint fbc = G.flag_break_continue;
3890 /* We might fall into outer *loop*,
3891 * don't want to break it too */
3893 G.depth_break_continue--;
3894 if (G.depth_break_continue == 0)
3895 G.flag_break_continue = 0;
3896 /* else: e.g. "continue 2" should *break* once, *then* continue */
3897 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3898 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3899 goto check_jobs_and_break;
3900 /* "continue": simulate end of loop */
3905 } else if (pi->followup == PIPE_BG) {
3906 /* What does bash do with attempts to background builtins? */
3907 /* even bash 3.2 doesn't do that well with nested bg:
3908 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3909 * I'm NOT treating inner &'s as jobs */
3910 check_and_run_traps(0);
3912 if (G.run_list_level == 1)
3915 G.last_exitcode = rcode = EXIT_SUCCESS;
3916 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3919 if (G.run_list_level == 1 && G_interactive_fd) {
3920 /* Waits for completion, then fg's main shell */
3921 rcode = checkjobs_and_fg_shell(pi);
3922 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3923 check_and_run_traps(0);
3926 { /* This one just waits for completion */
3927 rcode = checkjobs(pi);
3928 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3929 check_and_run_traps(0);
3931 G.last_exitcode = rcode;
3935 /* Analyze how result affects subsequent commands */
3937 if (rword == RES_IF || rword == RES_ELIF)
3940 #if ENABLE_HUSH_LOOPS
3941 /* Beware of "while false; true; do ..."! */
3942 if (pi->next && pi->next->res_word == RES_DO) {
3943 if (rword == RES_WHILE) {
3945 /* "while false; do...done" - exitcode 0 */
3946 G.last_exitcode = rcode = EXIT_SUCCESS;
3947 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3948 goto check_jobs_and_break;
3951 if (rword == RES_UNTIL) {
3953 debug_printf_exec(": until expr is true: breaking\n");
3954 check_jobs_and_break:
3962 check_jobs_and_continue:
3967 //// if (G.ctrl_z_flag) {
3968 //// /* ctrl-Z forked somewhere in the past, we are the child,
3969 //// * and now we completed running the list. Exit. */
3975 //// if (!G.run_list_level && G_interactive_fd) {
3976 //// signal(SIGTSTP, SIG_IGN);
3977 //// signal(SIGINT, SIG_IGN);
3980 #if ENABLE_HUSH_LOOPS
3985 #if ENABLE_HUSH_CASE
3989 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3993 /* Select which version we will use */
3994 static int run_and_free_list(struct pipe *pi)
3997 debug_printf_exec("run_and_free_list entered\n");
3999 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4000 rcode = run_list(pi);
4002 /* free_pipe_list has the side effect of clearing memory.
4003 * In the long run that function can be merged with run_list,
4004 * but doing that now would hobble the debugging effort. */
4006 debug_printf_exec("run_and_free_list return %d\n", rcode);
4011 static struct pipe *new_pipe(void)
4014 pi = xzalloc(sizeof(struct pipe));
4015 /*pi->followup = 0; - deliberately invalid value */
4016 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4020 /* Command (member of a pipe) is complete. The only possible error here
4021 * is out of memory, in which case xmalloc exits. */
4022 static int done_command(struct parse_context *ctx)
4024 /* The command is really already in the pipe structure, so
4025 * advance the pipe counter and make a new, null command. */
4026 struct pipe *pi = ctx->pipe;
4027 struct command *command = ctx->command;
4030 if (command->group == NULL
4031 && command->argv == NULL
4032 && command->redirects == NULL
4034 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4035 memset(command, 0, sizeof(*command)); /* paranoia */
4036 return pi->num_cmds;
4039 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4040 //debug_print_tree(ctx->list_head, 20);
4042 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4045 /* Only real trickiness here is that the uncommitted
4046 * command structure is not counted in pi->num_cmds. */
4047 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4048 command = &pi->cmds[pi->num_cmds];
4049 memset(command, 0, sizeof(*command));
4051 ctx->command = command;
4052 /* but ctx->pipe and ctx->list_head remain unchanged */
4054 return pi->num_cmds; /* used only for 0/nonzero check */
4057 static void done_pipe(struct parse_context *ctx, pipe_style type)
4061 debug_printf_parse("done_pipe entered, followup %d\n", type);
4062 /* Close previous command */
4063 not_null = done_command(ctx);
4064 ctx->pipe->followup = type;
4066 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4067 ctx->ctx_inverted = 0;
4068 ctx->pipe->res_word = ctx->ctx_res_w;
4071 /* Without this check, even just <enter> on command line generates
4072 * tree of three NOPs (!). Which is harmless but annoying.
4073 * IOW: it is safe to do it unconditionally.
4074 * RES_NONE case is for "for a in; do ..." (empty IN set)
4075 * and other cases to work. */
4078 || ctx->ctx_res_w == RES_FI
4080 #if ENABLE_HUSH_LOOPS
4081 || ctx->ctx_res_w == RES_DONE
4082 || ctx->ctx_res_w == RES_FOR
4083 || ctx->ctx_res_w == RES_IN
4085 #if ENABLE_HUSH_CASE
4086 || ctx->ctx_res_w == RES_ESAC
4090 debug_printf_parse("done_pipe: adding new pipe: "
4091 "not_null:%d ctx->ctx_res_w:%d\n",
4092 not_null, ctx->ctx_res_w);
4094 ctx->pipe->next = new_p;
4096 /* RES_THEN, RES_DO etc are "sticky" -
4097 * they remain set for commands inside if/while.
4098 * This is used to control execution.
4099 * RES_FOR and RES_IN are NOT sticky (needed to support
4100 * cases where variable or value happens to match a keyword):
4102 #if ENABLE_HUSH_LOOPS
4103 if (ctx->ctx_res_w == RES_FOR
4104 || ctx->ctx_res_w == RES_IN)
4105 ctx->ctx_res_w = RES_NONE;
4107 #if ENABLE_HUSH_CASE
4108 if (ctx->ctx_res_w == RES_MATCH)
4109 ctx->ctx_res_w = RES_CASEI;
4111 ctx->command = NULL; /* trick done_command below */
4112 /* Create the memory for command, roughly:
4113 * ctx->pipe->cmds = new struct command;
4114 * ctx->command = &ctx->pipe->cmds[0];
4117 //debug_print_tree(ctx->list_head, 10);
4119 debug_printf_parse("done_pipe return\n");
4122 static void initialize_context(struct parse_context *ctx)
4124 memset(ctx, 0, sizeof(*ctx));
4125 ctx->pipe = ctx->list_head = new_pipe();
4126 /* Create the memory for command, roughly:
4127 * ctx->pipe->cmds = new struct command;
4128 * ctx->command = &ctx->pipe->cmds[0];
4133 /* If a reserved word is found and processed, parse context is modified
4134 * and 1 is returned.
4137 struct reserved_combo {
4140 unsigned char assignment_flag;
4144 FLAG_END = (1 << RES_NONE ),
4146 FLAG_IF = (1 << RES_IF ),
4147 FLAG_THEN = (1 << RES_THEN ),
4148 FLAG_ELIF = (1 << RES_ELIF ),
4149 FLAG_ELSE = (1 << RES_ELSE ),
4150 FLAG_FI = (1 << RES_FI ),
4152 #if ENABLE_HUSH_LOOPS
4153 FLAG_FOR = (1 << RES_FOR ),
4154 FLAG_WHILE = (1 << RES_WHILE),
4155 FLAG_UNTIL = (1 << RES_UNTIL),
4156 FLAG_DO = (1 << RES_DO ),
4157 FLAG_DONE = (1 << RES_DONE ),
4158 FLAG_IN = (1 << RES_IN ),
4160 #if ENABLE_HUSH_CASE
4161 FLAG_MATCH = (1 << RES_MATCH),
4162 FLAG_ESAC = (1 << RES_ESAC ),
4164 FLAG_START = (1 << RES_XXXX ),
4167 static const struct reserved_combo* match_reserved_word(o_string *word)
4169 /* Mostly a list of accepted follow-up reserved words.
4170 * FLAG_END means we are done with the sequence, and are ready
4171 * to turn the compound list into a command.
4172 * FLAG_START means the word must start a new compound list.
4174 static const struct reserved_combo reserved_list[] = {
4176 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4177 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4178 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4179 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4180 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4181 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4183 #if ENABLE_HUSH_LOOPS
4184 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4185 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4186 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4187 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4188 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4189 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4191 #if ENABLE_HUSH_CASE
4192 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4193 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4196 const struct reserved_combo *r;
4198 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4199 if (strcmp(word->data, r->literal) == 0)
4204 static int reserved_word(o_string *word, struct parse_context *ctx)
4206 #if ENABLE_HUSH_CASE
4207 static const struct reserved_combo reserved_match = {
4208 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4211 const struct reserved_combo *r;
4213 r = match_reserved_word(word);
4217 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4218 #if ENABLE_HUSH_CASE
4219 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4220 /* "case word IN ..." - IN part starts first match part */
4221 r = &reserved_match;
4224 if (r->flag == 0) { /* '!' */
4225 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4226 syntax_error("! ! command");
4227 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
4229 ctx->ctx_inverted = 1;
4232 if (r->flag & FLAG_START) {
4233 struct parse_context *old;
4234 old = xmalloc(sizeof(*old));
4235 debug_printf_parse("push stack %p\n", old);
4236 *old = *ctx; /* physical copy */
4237 initialize_context(ctx);
4239 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4240 syntax_error_at(word->data);
4241 ctx->ctx_res_w = RES_SNTX;
4244 ctx->ctx_res_w = r->res;
4245 ctx->old_flag = r->flag;
4246 if (ctx->old_flag & FLAG_END) {
4247 struct parse_context *old;
4248 done_pipe(ctx, PIPE_SEQ);
4249 debug_printf_parse("pop stack %p\n", ctx->stack);
4251 old->command->group = ctx->list_head;
4252 old->command->grp_type = GRP_NORMAL;
4254 o_addstr(&old->as_string, ctx->as_string.data);
4255 o_free_unsafe(&ctx->as_string);
4256 old->command->group_as_string = xstrdup(old->as_string.data);
4257 debug_printf_parse("pop, remembering as:'%s'\n",
4258 old->command->group_as_string);
4260 *ctx = *old; /* physical copy */
4263 word->o_assignment = r->assignment_flag;
4268 /* Word is complete, look at it and update parsing context.
4269 * Normal return is 0. Syntax errors return 1.
4270 * Note: on return, word is reset, but not o_free'd!
4272 static int done_word(o_string *word, struct parse_context *ctx)
4274 struct command *command = ctx->command;
4276 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4277 if (word->length == 0 && word->o_quoted == 0) {
4278 debug_printf_parse("done_word return 0: true null, ignored\n");
4282 if (ctx->pending_redirect) {
4283 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4284 * only if run as "bash", not "sh" */
4285 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4287 * ...the word that follows the redirection operator
4288 * shall be subjected to tilde expansion, parameter expansion,
4289 * command substitution, arithmetic expansion, and quote
4290 * removal. Pathname expansion shall not be performed
4291 * on the word by a non-interactive shell; an interactive
4292 * shell may perform it, but shall do so only when
4293 * the expansion would result in one word."
4295 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4296 /* Cater for >\file case:
4297 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4298 * Same with heredocs:
4299 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4301 unbackslash(ctx->pending_redirect->rd_filename);
4302 /* Is it <<"HEREDOC"? */
4303 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4306 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4308 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4309 ctx->pending_redirect = NULL;
4311 /* If this word wasn't an assignment, next ones definitely
4312 * can't be assignments. Even if they look like ones. */
4313 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4314 && word->o_assignment != WORD_IS_KEYWORD
4316 word->o_assignment = NOT_ASSIGNMENT;
4318 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4319 command->assignment_cnt++;
4320 word->o_assignment = MAYBE_ASSIGNMENT;
4323 if (command->group) {
4324 /* "{ echo foo; } echo bar" - bad */
4325 /* NB: bash allows e.g.:
4326 * if true; then { echo foo; } fi
4327 * while if false; then false; fi do break; done
4329 * while if false; then false; fi; do; break; done
4331 syntax_error_at(word->data);
4332 debug_printf_parse("done_word return 1: syntax error, "
4333 "groups and arglists don't mix\n");
4337 # if ENABLE_HUSH_CASE
4338 if (ctx->ctx_dsemicolon
4339 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4341 /* already done when ctx_dsemicolon was set to 1: */
4342 /* ctx->ctx_res_w = RES_MATCH; */
4343 ctx->ctx_dsemicolon = 0;
4346 if (!command->argv /* if it's the first word... */
4347 # if ENABLE_HUSH_LOOPS
4348 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4349 && ctx->ctx_res_w != RES_IN
4352 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
4353 if (reserved_word(word, ctx)) {
4354 o_reset_to_empty_unquoted(word);
4355 debug_printf_parse("done_word return %d\n",
4356 (ctx->ctx_res_w == RES_SNTX));
4357 return (ctx->ctx_res_w == RES_SNTX);
4361 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4362 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4363 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4364 /* (otherwise it's known to be not empty and is already safe) */
4366 /* exclude "$@" - it can expand to no word despite "" */
4367 char *p = word->data;
4368 while (p[0] == SPECIAL_VAR_SYMBOL
4369 && (p[1] & 0x7f) == '@'
4370 && p[2] == SPECIAL_VAR_SYMBOL
4374 if (p == word->data || p[0] != '\0') {
4375 /* saw no "$@", or not only "$@" but some
4376 * real text is there too */
4377 /* insert "empty variable" reference, this makes
4378 * e.g. "", $empty"" etc to not disappear */
4379 o_addchr(word, SPECIAL_VAR_SYMBOL);
4380 o_addchr(word, SPECIAL_VAR_SYMBOL);
4383 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4384 //SEGV, but good idea.
4385 // command->argv = add_string_to_strings(command->argv, word->data);
4386 // word->data = NULL;
4387 // word->length = 0;
4388 debug_print_strings("word appended to argv", command->argv);
4391 #if ENABLE_HUSH_LOOPS
4392 if (ctx->ctx_res_w == RES_FOR) {
4394 || !is_well_formed_var_name(command->argv[0], '\0')
4396 /* bash says just "not a valid identifier" */
4397 syntax_error("not a valid identifier in for");
4400 /* Force FOR to have just one word (variable name) */
4401 /* NB: basically, this makes hush see "for v in ..."
4402 * syntax as if it is "for v; in ...". FOR and IN become
4403 * two pipe structs in parse tree. */
4404 done_pipe(ctx, PIPE_SEQ);
4407 #if ENABLE_HUSH_CASE
4408 /* Force CASE to have just one word */
4409 if (ctx->ctx_res_w == RES_CASE) {
4410 done_pipe(ctx, PIPE_SEQ);
4414 o_reset_to_empty_unquoted(word);
4416 debug_printf_parse("done_word return 0\n");
4421 /* Peek ahead in the input to find out if we have a "&n" construct,
4422 * as in "2>&1", that represents duplicating a file descriptor.
4424 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4425 * REDIRFD_SYNTAX_ERR if syntax error,
4426 * REDIRFD_TO_FILE if no & was seen,
4427 * or the number found.
4430 #define parse_redir_right_fd(as_string, input) \
4431 parse_redir_right_fd(input)
4433 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4439 return REDIRFD_TO_FILE;
4441 ch = i_getch(input); /* get the & */
4442 nommu_addchr(as_string, ch);
4445 ch = i_getch(input);
4446 nommu_addchr(as_string, ch);
4447 return REDIRFD_CLOSE;
4451 while (ch != EOF && isdigit(ch)) {
4452 d = d*10 + (ch-'0');
4454 ch = i_getch(input);
4455 nommu_addchr(as_string, ch);
4460 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4462 bb_error_msg("ambiguous redirect");
4463 return REDIRFD_SYNTAX_ERR;
4466 /* Return code is 0 normal, 1 if a syntax error is detected
4468 static int parse_redirect(struct parse_context *ctx,
4471 struct in_str *input)
4473 struct command *command = ctx->command;
4474 struct redir_struct *redir;
4475 struct redir_struct **redirp;
4478 dup_num = REDIRFD_TO_FILE;
4479 if (style != REDIRECT_HEREDOC) {
4480 /* Check for a '>&1' type redirect */
4481 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4482 if (dup_num == REDIRFD_SYNTAX_ERR)
4485 int ch = i_peek(input);
4486 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4487 if (dup_num) { /* <<-... */
4488 ch = i_getch(input);
4489 nommu_addchr(&ctx->as_string, ch);
4494 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4495 int ch = i_peek(input);
4497 /* >|FILE redirect ("clobbering" >).
4498 * Since we do not support "set -o noclobber" yet,
4499 * >| and > are the same for now. Just eat |.
4501 ch = i_getch(input);
4502 nommu_addchr(&ctx->as_string, ch);
4506 /* Create a new redir_struct and append it to the linked list */
4507 redirp = &command->redirects;
4508 while ((redir = *redirp) != NULL) {
4509 redirp = &(redir->next);
4511 *redirp = redir = xzalloc(sizeof(*redir));
4512 /* redir->next = NULL; */
4513 /* redir->rd_filename = NULL; */
4514 redir->rd_type = style;
4515 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4517 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4518 redir_table[style].descrip);
4520 redir->rd_dup = dup_num;
4521 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4522 /* Erik had a check here that the file descriptor in question
4523 * is legit; I postpone that to "run time"
4524 * A "-" representation of "close me" shows up as a -3 here */
4525 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4526 redir->rd_fd, redir->rd_dup);
4528 /* Set ctx->pending_redirect, so we know what to do at the
4529 * end of the next parsed word. */
4530 ctx->pending_redirect = redir;
4535 /* If a redirect is immediately preceded by a number, that number is
4536 * supposed to tell which file descriptor to redirect. This routine
4537 * looks for such preceding numbers. In an ideal world this routine
4538 * needs to handle all the following classes of redirects...
4539 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4540 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4541 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4542 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4544 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4546 * ... If n is quoted, the number shall not be recognized as part of
4547 * the redirection expression. For example:
4549 * writes the character 2 into file a"
4550 * We are getting it right by setting ->o_quoted on any \<char>
4552 * A -1 return means no valid number was found,
4553 * the caller should use the appropriate default for this redirection.
4555 static int redirect_opt_num(o_string *o)
4559 if (o->data == NULL)
4561 num = bb_strtou(o->data, NULL, 10);
4562 if (errno || num < 0)
4564 o_reset_to_empty_unquoted(o);
4569 #define fetch_till_str(as_string, input, word, skip_tabs) \
4570 fetch_till_str(input, word, skip_tabs)
4572 static char *fetch_till_str(o_string *as_string,
4573 struct in_str *input,
4577 o_string heredoc = NULL_O_STRING;
4583 ch = i_getch(input);
4584 nommu_addchr(as_string, ch);
4586 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4587 heredoc.data[past_EOL] = '\0';
4588 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4589 return heredoc.data;
4592 o_addchr(&heredoc, ch);
4593 past_EOL = heredoc.length;
4596 ch = i_getch(input);
4597 nommu_addchr(as_string, ch);
4598 } while (skip_tabs && ch == '\t');
4599 } while (ch == '\n');
4602 o_free_unsafe(&heredoc);
4605 o_addchr(&heredoc, ch);
4606 nommu_addchr(as_string, ch);
4610 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4611 * and load them all. There should be exactly heredoc_cnt of them.
4613 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4615 struct pipe *pi = ctx->list_head;
4617 while (pi && heredoc_cnt) {
4619 struct command *cmd = pi->cmds;
4621 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4623 cmd->argv ? cmd->argv[0] : "NONE");
4624 for (i = 0; i < pi->num_cmds; i++) {
4625 struct redir_struct *redir = cmd->redirects;
4627 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4628 i, cmd->argv ? cmd->argv[0] : "NONE");
4630 if (redir->rd_type == REDIRECT_HEREDOC) {
4633 redir->rd_type = REDIRECT_HEREDOC2;
4634 /* redir->dup is (ab)used to indicate <<- */
4635 p = fetch_till_str(&ctx->as_string, input,
4636 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4638 syntax_error("unexpected EOF in here document");
4641 free(redir->rd_filename);
4642 redir->rd_filename = p;
4645 redir = redir->next;
4652 /* Should be 0. If it isn't, it's a parse error */
4654 bb_error_msg_and_die("heredoc BUG 2");
4660 #if ENABLE_HUSH_TICK
4661 static FILE *generate_stream_from_string(const char *s)
4664 int pid, channel[2];
4670 pid = BB_MMU ? fork() : vfork();
4672 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4674 if (pid == 0) { /* child */
4675 disable_restore_tty_pgrp_on_exit();
4676 /* Process substitution is not considered to be usual
4677 * 'command execution'.
4678 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4685 close(channel[0]); /* NB: close _first_, then move fd! */
4686 xmove_fd(channel[1], 1);
4687 /* Prevent it from trying to handle ctrl-z etc */
4688 USE_HUSH_JOB(G.run_list_level = 1;)
4690 reset_traps_to_defaults();
4691 parse_and_run_string(s);
4692 _exit(G.last_exitcode);
4694 /* We re-execute after vfork on NOMMU. This makes this script safe:
4695 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4696 * huge=`cat BIG` # was blocking here forever
4699 re_execute_shell(&to_free,
4707 enable_restore_tty_pgrp_on_exit();
4712 pf = fdopen(channel[0], "r");
4716 /* Return code is exit status of the process that is run. */
4717 static int process_command_subs(o_string *dest, const char *s)
4720 struct in_str pipe_str;
4723 pf = generate_stream_from_string(s);
4726 close_on_exec_on(fileno(pf));
4728 /* Now send results of command back into original context */
4729 setup_file_in_str(&pipe_str, pf);
4731 while ((ch = i_getch(&pipe_str)) != EOF) {
4737 o_addchr(dest, '\n');
4740 o_addQchr(dest, ch);
4743 debug_printf("done reading from pipe, pclose()ing\n");
4744 /* Note: we got EOF, and we just close the read end of the pipe.
4745 * We do not wait for the `cmd` child to terminate. bash and ash do.
4747 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4748 * `false`; echo $? - bash outputs "1"
4751 debug_printf("closed FILE from child. return 0\n");
4756 static int parse_group(o_string *dest, struct parse_context *ctx,
4757 struct in_str *input, int ch)
4759 /* dest contains characters seen prior to ( or {.
4760 * Typically it's empty, but for function defs,
4761 * it contains function name (without '()'). */
4762 struct pipe *pipe_list;
4764 struct command *command = ctx->command;
4766 debug_printf_parse("parse_group entered\n");
4767 #if ENABLE_HUSH_FUNCTIONS
4768 if (ch == '(' && !dest->o_quoted) {
4770 done_word(dest, ctx);
4772 goto skip; /* (... */
4773 if (command->argv[1]) { /* word word ... (... */
4774 syntax_error_unexpected_ch('(');
4777 /* it is "word(..." or "word (..." */
4779 ch = i_getch(input);
4780 while (ch == ' ' || ch == '\t');
4782 syntax_error_unexpected_ch(ch);
4785 nommu_addchr(&ctx->as_string, ch);
4787 ch = i_getch(input);
4788 while (ch == ' ' || ch == '\t' || ch == '\n');
4790 syntax_error_unexpected_ch(ch);
4793 nommu_addchr(&ctx->as_string, ch);
4794 command->grp_type = GRP_FUNCTION;
4798 if (command->argv /* word [word]{... */
4799 || dest->length /* word{... */
4800 || dest->o_quoted /* ""{... */
4803 debug_printf_parse("parse_group return 1: "
4804 "syntax error, groups and arglists don't mix\n");
4808 #if ENABLE_HUSH_FUNCTIONS
4814 command->grp_type = GRP_SUBSHELL;
4819 char *as_string = NULL;
4821 pipe_list = parse_stream(&as_string, input, endch);
4824 o_addstr(&ctx->as_string, as_string);
4826 /* empty ()/{} or parse error? */
4827 if (!pipe_list || pipe_list == ERR_PTR) {
4832 debug_printf_parse("parse_group return 1: "
4833 "parse_stream returned %p\n", pipe_list);
4836 command->group = pipe_list;
4838 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4839 command->group_as_string = as_string;
4840 debug_printf_parse("end of group, remembering as:'%s'\n",
4841 command->group_as_string);
4844 debug_printf_parse("parse_group return 0\n");
4846 /* command remains "open", available for possible redirects */
4849 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4850 /* Subroutines for copying $(...) and `...` things */
4851 static void add_till_backquote(o_string *dest, struct in_str *input);
4853 static void add_till_single_quote(o_string *dest, struct in_str *input)
4856 int ch = i_getch(input);
4858 syntax_error_unterm_ch('\'');
4859 /*xfunc_die(); - redundant */
4866 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4867 static void add_till_double_quote(o_string *dest, struct in_str *input)
4870 int ch = i_getch(input);
4872 syntax_error_unterm_ch('"');
4873 /*xfunc_die(); - redundant */
4877 if (ch == '\\') { /* \x. Copy both chars. */
4879 ch = i_getch(input);
4883 add_till_backquote(dest, input);
4887 //if (ch == '$') ...
4890 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4892 * "Within the backquoted style of command substitution, backslash
4893 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4894 * The search for the matching backquote shall be satisfied by the first
4895 * backquote found without a preceding backslash; during this search,
4896 * if a non-escaped backquote is encountered within a shell comment,
4897 * a here-document, an embedded command substitution of the $(command)
4898 * form, or a quoted string, undefined results occur. A single-quoted
4899 * or double-quoted string that begins, but does not end, within the
4900 * "`...`" sequence produces undefined results."
4902 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4904 static void add_till_backquote(o_string *dest, struct in_str *input)
4907 int ch = i_getch(input);
4909 syntax_error_unterm_ch('`');
4910 /*xfunc_die(); - redundant */
4915 /* \x. Copy both chars unless it is \` */
4916 int ch2 = i_getch(input);
4918 syntax_error_unterm_ch('`');
4919 /*xfunc_die(); - redundant */
4921 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4928 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4929 * quoting and nested ()s.
4930 * "With the $(command) style of command substitution, all characters
4931 * following the open parenthesis to the matching closing parenthesis
4932 * constitute the command. Any valid shell script can be used for command,
4933 * except a script consisting solely of redirections which produces
4934 * unspecified results."
4936 * echo $(echo '(TEST)' BEST) (TEST) BEST
4937 * echo $(echo 'TEST)' BEST) TEST) BEST
4938 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4940 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4944 int ch = i_getch(input);
4946 syntax_error_unterm_ch(')');
4947 /*xfunc_die(); - redundant */
4955 if (i_peek(input) == ')') {
4963 add_till_single_quote(dest, input);
4968 add_till_double_quote(dest, input);
4973 /* \x. Copy verbatim. Important for \(, \) */
4974 ch = i_getch(input);
4976 syntax_error_unterm_ch(')');
4977 /*xfunc_die(); - redundant */
4984 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4986 /* Return code: 0 for OK, 1 for syntax error */
4988 #define handle_dollar(as_string, dest, input) \
4989 handle_dollar(dest, input)
4991 static int handle_dollar(o_string *as_string,
4993 struct in_str *input)
4996 int ch = i_peek(input); /* first character after the $ */
4997 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4999 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5001 ch = i_getch(input);
5002 nommu_addchr(as_string, ch);
5004 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5006 debug_printf_parse(": '%c'\n", ch);
5007 o_addchr(dest, ch | quote_mask);
5010 if (!isalnum(ch) && ch != '_')
5012 ch = i_getch(input);
5013 nommu_addchr(as_string, ch);
5015 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5016 } else if (isdigit(ch)) {
5018 ch = i_getch(input);
5019 nommu_addchr(as_string, ch);
5020 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5021 debug_printf_parse(": '%c'\n", ch);
5022 o_addchr(dest, ch | quote_mask);
5023 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5024 } else switch (ch) {
5026 case '!': /* last bg pid */
5027 case '?': /* last exit code */
5028 case '#': /* number of args */
5029 case '*': /* args */
5030 case '@': /* args */
5031 goto make_one_char_var;
5033 bool first_char, all_digits;
5035 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5036 ch = i_getch(input);
5037 nommu_addchr(as_string, ch);
5038 /* XXX maybe someone will try to escape the '}' */
5043 ch = i_getch(input);
5044 nommu_addchr(as_string, ch);
5050 /* ${#var}: length of var contents */
5052 else if (isdigit(ch)) {
5059 && ( (all_digits && !isdigit(ch))
5060 || (!all_digits && !isalnum(ch) && ch != '_')
5063 /* handle parameter expansions
5064 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5069 case ':': /* null modifier */
5070 if (expansion == 0) {
5071 debug_printf_parse(": null modifier\n");
5076 case '#': /* remove prefix */
5077 case '%': /* remove suffix */
5078 if (expansion == 0) {
5079 debug_printf_parse(": remove suffix/prefix\n");
5084 case '-': /* default value */
5085 case '=': /* assign default */
5086 case '+': /* alternative */
5087 case '?': /* error indicate */
5088 debug_printf_parse(": parameter expansion\n");
5093 syntax_error_unterm_str("${name}");
5094 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5099 debug_printf_parse(": '%c'\n", ch);
5100 o_addchr(dest, ch | quote_mask);
5104 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5107 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5112 ch = i_getch(input);
5113 nommu_addchr(as_string, ch);
5114 # if ENABLE_SH_MATH_SUPPORT
5115 if (i_peek(input) == '(') {
5116 ch = i_getch(input);
5117 nommu_addchr(as_string, ch);
5118 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5119 o_addchr(dest, /*quote_mask |*/ '+');
5123 add_till_closing_paren(dest, input, true);
5126 o_addstr(as_string, dest->data + pos);
5127 o_addchr(as_string, ')');
5128 o_addchr(as_string, ')');
5131 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5135 # if ENABLE_HUSH_TICK
5136 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5137 o_addchr(dest, quote_mask | '`');
5141 add_till_closing_paren(dest, input, false);
5144 o_addstr(as_string, dest->data + pos);
5145 o_addchr(as_string, '`');
5148 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5154 ch = i_getch(input);
5155 nommu_addchr(as_string, ch);
5157 if (isalnum(ch)) { /* it's $_name or $_123 */
5163 /* $_ Shell or shell script name; or last cmd name */
5164 /* $- Option flags set by set builtin or shell options (-i etc) */
5166 o_addQchr(dest, '$');
5168 debug_printf_parse("handle_dollar return 0\n");
5173 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5174 parse_stream_dquoted(dest, input, dquote_end)
5176 static int parse_stream_dquoted(o_string *as_string,
5178 struct in_str *input,
5185 ch = i_getch(input);
5187 nommu_addchr(as_string, ch);
5188 if (ch == dquote_end) { /* may be only '"' or EOF */
5189 if (dest->o_assignment == NOT_ASSIGNMENT)
5190 dest->o_escape ^= 1;
5191 debug_printf_parse("parse_stream_dquoted return 0\n");
5194 /* note: can't move it above ch == dquote_end check! */
5196 syntax_error_unterm_ch('"');
5197 /*xfunc_die(); - redundant */
5201 next = i_peek(input);
5203 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5204 ch, ch, dest->o_escape);
5207 syntax_error("\\<eof>");
5211 * "The backslash retains its special meaning [in "..."]
5212 * only when followed by one of the following characters:
5213 * $, `, ", \, or <newline>. A double quote may be quoted
5214 * within double quotes by preceding it with a backslash.
5216 if (strchr("$`\"\\", next) != NULL) {
5217 o_addqchr(dest, i_getch(input));
5219 o_addqchr(dest, '\\');
5224 if (handle_dollar(as_string, dest, input) != 0) {
5225 debug_printf_parse("parse_stream_dquoted return 1: "
5226 "handle_dollar returned non-0\n");
5231 #if ENABLE_HUSH_TICK
5233 //int pos = dest->length;
5234 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5235 o_addchr(dest, 0x80 | '`');
5236 add_till_backquote(dest, input);
5237 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5238 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5242 o_addQchr(dest, ch);
5244 && (dest->o_assignment == MAYBE_ASSIGNMENT
5245 || dest->o_assignment == WORD_IS_KEYWORD)
5246 && is_well_formed_var_name(dest->data, '=')
5248 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5254 * Scan input until EOF or end_trigger char.
5255 * Return a list of pipes to execute, or NULL on EOF
5256 * or if end_trigger character is met.
5257 * On syntax error, exit is shell is not interactive,
5258 * reset parsing machinery and start parsing anew,
5259 * or return ERR_PTR.
5261 static struct pipe *parse_stream(char **pstring,
5262 struct in_str *input,
5265 struct parse_context ctx;
5266 o_string dest = NULL_O_STRING;
5270 /* Double-quote state is handled in the state variable is_in_dquote.
5271 * A single-quote triggers a bypass of the main loop until its mate is
5272 * found. When recursing, quote state is passed in via dest->o_escape.
5274 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5275 end_trigger ? : 'X');
5278 G.ifs = get_local_var_value("IFS");
5283 #if ENABLE_HUSH_INTERACTIVE
5284 input->promptmode = 0; /* PS1 */
5286 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5287 initialize_context(&ctx);
5292 const char *is_special;
5296 redir_type redir_style;
5299 /* dest.o_quoted = 1; - already is (see below) */
5300 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5303 /* We reached closing '"' */
5306 ch = i_getch(input);
5307 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5308 ch, ch, dest.o_escape);
5313 syntax_error_unterm_str("here document");
5316 if (done_word(&dest, &ctx)) {
5320 done_pipe(&ctx, PIPE_SEQ);
5322 /* If we got nothing... */
5323 /* (this makes bare "&" cmd a no-op.
5324 * bash says: "syntax error near unexpected token '&'") */
5325 if (pi->num_cmds == 0
5326 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5332 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5334 *pstring = ctx.as_string.data;
5336 o_free_unsafe(&ctx.as_string);
5339 debug_printf_parse("parse_stream return %p\n", pi);
5342 nommu_addchr(&ctx.as_string, ch);
5343 is_ifs = strchr(G.ifs, ch);
5344 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5345 "\\$\"" USE_HUSH_TICK("`") /* always special */
5348 if (!is_special && !is_ifs) { /* ordinary char */
5349 o_addQchr(&dest, ch);
5350 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5351 || dest.o_assignment == WORD_IS_KEYWORD)
5353 && is_well_formed_var_name(dest.data, '=')
5355 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5361 if (done_word(&dest, &ctx)) {
5365 #if ENABLE_HUSH_CASE
5366 /* "case ... in <newline> word) ..." -
5367 * newlines are ignored (but ';' wouldn't be) */
5368 if (ctx.command->argv == NULL
5369 && ctx.ctx_res_w == RES_MATCH
5374 /* Treat newline as a command separator. */
5375 done_pipe(&ctx, PIPE_SEQ);
5376 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5378 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5383 dest.o_assignment = MAYBE_ASSIGNMENT;
5385 /* note: if (is_ifs) continue;
5386 * will still trigger for us */
5389 if (end_trigger && end_trigger == ch
5390 && (heredoc_cnt == 0 || end_trigger != ';')
5392 //TODO: disallow "{ cmd }" without semicolon
5394 /* This is technically valid:
5395 * { cat <<HERE; }; echo Ok
5400 * but we don't support this.
5401 * We require heredoc to be in enclosing {}/(),
5404 syntax_error_unterm_str("here document");
5407 if (done_word(&dest, &ctx)) {
5410 done_pipe(&ctx, PIPE_SEQ);
5411 dest.o_assignment = MAYBE_ASSIGNMENT;
5412 /* Do we sit outside of any if's, loops or case's? */
5414 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5418 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5420 *pstring = ctx.as_string.data;
5422 o_free_unsafe(&ctx.as_string);
5425 debug_printf_parse("parse_stream return %p: "
5426 "end_trigger char found\n",
5428 return ctx.list_head;
5436 next = i_peek(input);
5439 /* Catch <, > before deciding whether this word is
5440 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5443 redir_fd = redirect_opt_num(&dest);
5444 if (done_word(&dest, &ctx)) {
5447 redir_style = REDIRECT_OVERWRITE;
5449 redir_style = REDIRECT_APPEND;
5450 ch = i_getch(input);
5451 nommu_addchr(&ctx.as_string, ch);
5454 else if (next == '(') {
5455 syntax_error(">(process) not supported");
5459 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5461 continue; /* back to top of while (1) */
5463 redir_fd = redirect_opt_num(&dest);
5464 if (done_word(&dest, &ctx)) {
5467 redir_style = REDIRECT_INPUT;
5469 redir_style = REDIRECT_HEREDOC;
5471 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5472 ch = i_getch(input);
5473 nommu_addchr(&ctx.as_string, ch);
5474 } else if (next == '>') {
5475 redir_style = REDIRECT_IO;
5476 ch = i_getch(input);
5477 nommu_addchr(&ctx.as_string, ch);
5480 else if (next == '(') {
5481 syntax_error("<(process) not supported");
5485 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5487 continue; /* back to top of while (1) */
5490 if (dest.o_assignment == MAYBE_ASSIGNMENT
5491 /* check that we are not in word in "a=1 2>word b=1": */
5492 && !ctx.pending_redirect
5494 /* ch is a special char and thus this word
5495 * cannot be an assignment */
5496 dest.o_assignment = NOT_ASSIGNMENT;
5501 if (dest.length == 0) {
5504 if (ch == EOF || ch == '\n')
5507 /* note: we do not add it to &ctx.as_string */
5509 nommu_addchr(&ctx.as_string, '\n');
5511 o_addQchr(&dest, ch);
5516 syntax_error("\\<eof>");
5519 o_addchr(&dest, '\\');
5520 ch = i_getch(input);
5521 nommu_addchr(&ctx.as_string, ch);
5522 o_addchr(&dest, ch);
5523 /* Example: echo Hello \2>file
5524 * we need to know that word 2 is quoted */
5528 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5529 debug_printf_parse("parse_stream parse error: "
5530 "handle_dollar returned non-0\n");
5537 ch = i_getch(input);
5539 syntax_error_unterm_ch('\'');
5540 /*xfunc_die(); - redundant */
5542 nommu_addchr(&ctx.as_string, ch);
5545 if (dest.o_assignment == NOT_ASSIGNMENT)
5546 o_addqchr(&dest, ch);
5548 o_addchr(&dest, ch);
5553 is_in_dquote ^= 1; /* invert */
5554 if (dest.o_assignment == NOT_ASSIGNMENT)
5557 #if ENABLE_HUSH_TICK
5562 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5563 o_addchr(&dest, '`');
5567 add_till_backquote(&dest, input);
5569 o_addstr(&ctx.as_string, dest.data + pos);
5570 o_addchr(&ctx.as_string, '`');
5572 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5573 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5578 #if ENABLE_HUSH_CASE
5581 if (done_word(&dest, &ctx)) {
5584 done_pipe(&ctx, PIPE_SEQ);
5585 #if ENABLE_HUSH_CASE
5586 /* Eat multiple semicolons, detect
5587 * whether it means something special */
5592 ch = i_getch(input);
5593 nommu_addchr(&ctx.as_string, ch);
5594 if (ctx.ctx_res_w == RES_CASEI) {
5595 ctx.ctx_dsemicolon = 1;
5596 ctx.ctx_res_w = RES_MATCH;
5602 /* We just finished a cmd. New one may start
5603 * with an assignment */
5604 dest.o_assignment = MAYBE_ASSIGNMENT;
5607 if (done_word(&dest, &ctx)) {
5611 ch = i_getch(input);
5612 nommu_addchr(&ctx.as_string, ch);
5613 done_pipe(&ctx, PIPE_AND);
5615 done_pipe(&ctx, PIPE_BG);
5619 if (done_word(&dest, &ctx)) {
5622 #if ENABLE_HUSH_CASE
5623 if (ctx.ctx_res_w == RES_MATCH)
5624 break; /* we are in case's "word | word)" */
5626 if (next == '|') { /* || */
5627 ch = i_getch(input);
5628 nommu_addchr(&ctx.as_string, ch);
5629 done_pipe(&ctx, PIPE_OR);
5631 /* we could pick up a file descriptor choice here
5632 * with redirect_opt_num(), but bash doesn't do it.
5633 * "echo foo 2| cat" yields "foo 2". */
5638 #if ENABLE_HUSH_CASE
5639 /* "case... in [(]word)..." - skip '(' */
5640 if (ctx.ctx_res_w == RES_MATCH
5641 && ctx.command->argv == NULL /* not (word|(... */
5642 && dest.length == 0 /* not word(... */
5643 && dest.o_quoted == 0 /* not ""(... */
5649 if (parse_group(&dest, &ctx, input, ch) != 0) {
5654 #if ENABLE_HUSH_CASE
5655 if (ctx.ctx_res_w == RES_MATCH)
5659 /* proper use of this character is caught by end_trigger:
5660 * if we see {, we call parse_group(..., end_trigger='}')
5661 * and it will match } earlier (not here). */
5662 syntax_error_unexpected_ch(ch);
5666 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5672 struct parse_context *pctx;
5673 IF_HAS_KEYWORDS(struct parse_context *p2;)
5675 /* Clean up allocated tree.
5676 * Samples for finding leaks on syntax error recovery path.
5677 * Run them from interactive shell, watch pmap `pidof hush`.
5678 * while if false; then false; fi do break; done
5680 * while if false; then false; fi; do break; fi
5681 * Samples to catch leaks at execution:
5682 * while if (true | {true;}); then echo ok; fi; do break; done
5683 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5687 /* Update pipe/command counts,
5688 * otherwise freeing may miss some */
5689 done_pipe(pctx, PIPE_SEQ);
5690 debug_printf_clean("freeing list %p from ctx %p\n",
5691 pctx->list_head, pctx);
5692 debug_print_tree(pctx->list_head, 0);
5693 free_pipe_list(pctx->list_head);
5694 debug_printf_clean("freed list %p\n", pctx->list_head);
5696 o_free_unsafe(&pctx->as_string);
5698 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5702 IF_HAS_KEYWORDS(pctx = p2;)
5703 } while (HAS_KEYWORDS && pctx);
5704 /* Free text, clear all dest fields */
5706 /* If we are not in top-level parse, we return,
5707 * our caller will propagate error.
5709 if (end_trigger != ';') {
5717 /* Discard cached input, force prompt */
5719 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5724 /* Executing from string: eval, sh -c '...'
5725 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5726 * end_trigger controls how often we stop parsing
5727 * NUL: parse all, execute, return
5728 * ';': parse till ';' or newline, execute, repeat till EOF
5730 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5733 struct pipe *pipe_list;
5735 pipe_list = parse_stream(NULL, inp, end_trigger);
5736 if (!pipe_list) /* EOF */
5738 debug_print_tree(pipe_list, 0);
5739 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5740 run_and_free_list(pipe_list);
5744 static void parse_and_run_string(const char *s)
5746 struct in_str input;
5747 setup_string_in_str(&input, s);
5748 parse_and_run_stream(&input, '\0');
5751 static void parse_and_run_file(FILE *f)
5753 struct in_str input;
5754 setup_file_in_str(&input, f);
5755 parse_and_run_stream(&input, ';');
5758 /* Called a few times only (or even once if "sh -c") */
5759 static void block_signals(int second_time)
5764 mask = (1 << SIGQUIT);
5765 if (G_interactive_fd) {
5769 //TODO | (1 << SIGHUP)
5771 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5776 G.non_DFL_mask = mask;
5779 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5783 sigaddset(&G.blocked_set, sig);
5787 sigdelset(&G.blocked_set, SIGCHLD);
5789 sigprocmask(SIG_SETMASK, &G.blocked_set,
5790 second_time ? NULL : &G.inherited_set);
5791 /* POSIX allows shell to re-enable SIGCHLD
5792 * even if it was SIG_IGN on entry */
5793 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5795 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5800 static void maybe_set_to_sigexit(int sig)
5802 void (*handler)(int);
5803 /* non_DFL_mask'ed signals are, well, masked,
5804 * no need to set handler for them.
5806 if (!((G.non_DFL_mask >> sig) & 1)) {
5807 handler = signal(sig, sigexit);
5808 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5809 signal(sig, handler);
5812 /* Set handlers to restore tty pgrp and exit */
5813 static void set_fatal_handlers(void)
5815 /* We _must_ restore tty pgrp on fatal signals */
5817 maybe_set_to_sigexit(SIGILL );
5818 maybe_set_to_sigexit(SIGFPE );
5819 maybe_set_to_sigexit(SIGBUS );
5820 maybe_set_to_sigexit(SIGSEGV);
5821 maybe_set_to_sigexit(SIGTRAP);
5822 } /* else: hush is perfect. what SEGV? */
5823 maybe_set_to_sigexit(SIGABRT);
5824 /* bash 3.2 seems to handle these just like 'fatal' ones */
5825 maybe_set_to_sigexit(SIGPIPE);
5826 maybe_set_to_sigexit(SIGALRM);
5827 //TODO: disable and move down when proper SIGHUP handling is added
5828 maybe_set_to_sigexit(SIGHUP );
5829 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5830 * if we aren't interactive... but in this case
5831 * we never want to restore pgrp on exit, and this fn is not called */
5832 /*maybe_set_to_sigexit(SIGTERM);*/
5833 /*maybe_set_to_sigexit(SIGINT );*/
5837 static int set_mode(const char cstate, const char mode)
5839 int state = (cstate == '-' ? 1 : 0);
5841 case 'n': G.fake_mode = state; break;
5842 case 'x': /*G.debug_mode = state;*/ break;
5843 default: return EXIT_FAILURE;
5845 return EXIT_SUCCESS;
5848 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5849 int hush_main(int argc, char **argv)
5851 static const struct variable const_shell_ver = {
5853 .varstr = (char*)hush_version_str,
5854 .max_len = 1, /* 0 can provoke free(name) */
5858 int signal_mask_is_inited = 0;
5861 struct variable *cur_var;
5864 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5865 G.last_exitcode = EXIT_SUCCESS;
5867 G.argv0_for_re_execing = argv[0];
5869 /* Deal with HUSH_VERSION */
5870 G.shell_ver = const_shell_ver; /* copying struct here */
5871 G.top_var = &G.shell_ver;
5872 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5873 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5874 /* Initialize our shell local variables with the values
5875 * currently living in the environment */
5876 cur_var = G.top_var;
5879 char *value = strchr(*e, '=');
5880 if (value) { /* paranoia */
5881 cur_var->next = xzalloc(sizeof(*cur_var));
5882 cur_var = cur_var->next;
5883 cur_var->varstr = *e;
5884 cur_var->max_len = strlen(*e);
5885 cur_var->flg_export = 1;
5889 debug_printf_env("putenv '%s'\n", hush_version_str);
5890 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5891 #if ENABLE_FEATURE_EDITING
5892 G.line_input_state = new_line_input_t(FOR_SHELL);
5894 G.global_argc = argc;
5895 G.global_argv = argv;
5896 /* Initialize some more globals to non-zero values */
5898 #if ENABLE_HUSH_INTERACTIVE
5899 if (ENABLE_FEATURE_EDITING)
5900 cmdedit_set_initial_prompt();
5904 if (setjmp(die_jmp)) {
5905 /* xfunc has failed! die die die */
5906 /* no EXIT traps, this is an escape hatch! */
5908 hush_exit(xfunc_error_retval);
5911 /* Shell is non-interactive at first. We need to call
5912 * block_signals(0) if we are going to execute "sh <script>",
5913 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5914 * If we later decide that we are interactive, we run block_signals(0)
5915 * (or re-run block_signals(1) if we ran block_signals(0) before)
5916 * in order to intercept (more) signals.
5920 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5922 opt = getopt(argc, argv, "c:xins"
5925 # if ENABLE_HUSH_FUNCTIONS
5935 G.root_pid = getpid();
5936 G.global_argv = argv + optind;
5937 if (!argv[optind]) {
5938 /* -c 'script' (no params): prevent empty $0 */
5939 *--G.global_argv = argv[0];
5941 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5942 G.global_argc = argc - optind;
5943 block_signals(0); /* 0: called 1st time */
5944 parse_and_run_string(optarg);
5947 /* Well, we cannot just declare interactiveness,
5948 * we have to have some stuff (ctty, etc) */
5949 /* G_interactive_fd++; */
5952 /* "-s" means "read from stdin", but this is how we always
5953 * operate, so simply do nothing here. */
5956 case '<': /* "big heredoc" support */
5957 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5960 G.root_pid = bb_strtou(optarg, &optarg, 16);
5962 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5964 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5965 # if ENABLE_HUSH_LOOPS
5967 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5972 set_local_var(xstrdup(optarg), 0, opt == 'R');
5974 # if ENABLE_HUSH_FUNCTIONS
5976 struct function *funcp = new_function(optarg);
5977 /* funcp->name is already set to optarg */
5978 /* funcp->body is set to NULL. It's a special case. */
5979 funcp->body_as_string = argv[optind];
5987 if (!set_mode('-', opt))
5991 fprintf(stderr, "Usage: sh [FILE]...\n"
5992 " or: sh -c command [args]...\n\n");
5998 } /* option parsing loop */
6001 G.root_pid = getpid();
6003 /* If we are login shell... */
6004 if (argv[0] && argv[0][0] == '-') {
6006 /* XXX what should argv be while sourcing /etc/profile? */
6007 debug_printf("sourcing /etc/profile\n");
6008 input = fopen_for_read("/etc/profile");
6009 if (input != NULL) {
6010 close_on_exec_on(fileno(input));
6011 block_signals(0); /* 0: called 1st time */
6012 signal_mask_is_inited = 1;
6013 parse_and_run_file(input);
6016 /* bash: after sourcing /etc/profile,
6017 * tries to source (in the given order):
6018 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6019 * stopping of first found. --noprofile turns this off.
6020 * bash also sources ~/.bash_logout on exit.
6021 * If called as sh, skips .bash_XXX files.
6028 * "bash <script>" (which is never interactive (unless -i?))
6029 * sources $BASH_ENV here (without scanning $PATH).
6030 * If called as sh, does the same but with $ENV.
6032 debug_printf("running script '%s'\n", argv[optind]);
6033 G.global_argv = argv + optind;
6034 G.global_argc = argc - optind;
6035 input = xfopen_for_read(argv[optind]);
6036 close_on_exec_on(fileno(input));
6037 if (!signal_mask_is_inited)
6038 block_signals(0); /* 0: called 1st time */
6039 parse_and_run_file(input);
6040 #if ENABLE_FEATURE_CLEAN_UP
6046 /* Up to here, shell was non-interactive. Now it may become one.
6047 * NB: don't forget to (re)run block_signals(0/1) as needed.
6050 /* A shell is interactive if the '-i' flag was given, or if all of
6051 * the following conditions are met:
6053 * no arguments remaining or the -s flag given
6054 * standard input is a terminal
6055 * standard output is a terminal
6056 * Refer to Posix.2, the description of the 'sh' utility.
6059 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6060 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6061 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6062 //TODO: "interactive" and "have job control" are two different things.
6063 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6064 //should stay on! Currently, we mix these into one.
6065 if (G.saved_tty_pgrp >= 0) {
6066 /* try to dup stdin to high fd#, >= 255 */
6067 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6068 if (G_interactive_fd < 0) {
6069 /* try to dup to any fd */
6070 G_interactive_fd = dup(STDIN_FILENO);
6071 if (G_interactive_fd < 0)
6073 G_interactive_fd = 0;
6075 // TODO: track & disallow any attempts of user
6076 // to (inadvertently) close/redirect it
6079 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6080 if (G_interactive_fd) {
6083 /* We are indeed interactive shell, and we will perform
6084 * job control. Setting up for that. */
6086 close_on_exec_on(G_interactive_fd);
6087 /* If we were run as 'hush &', sleep until we are
6088 * in the foreground (tty pgrp == our pgrp).
6089 * If we get started under a job aware app (like bash),
6090 * make sure we are now in charge so we don't fight over
6091 * who gets the foreground */
6093 shell_pgrp = getpgrp();
6094 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6095 if (G.saved_tty_pgrp == shell_pgrp)
6097 /* send TTIN to ourself (should stop us) */
6098 kill(- shell_pgrp, SIGTTIN);
6100 /* Block some signals */
6101 block_signals(signal_mask_is_inited);
6102 /* Set other signals to restore saved_tty_pgrp */
6103 set_fatal_handlers();
6104 /* Put ourselves in our own process group */
6105 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6106 /* Grab control of the terminal */
6107 tcsetpgrp(G_interactive_fd, getpid());
6108 /* -1 is special - makes xfuncs longjmp, not exit
6109 * (we reset die_sleep = 0 whereever we [v]fork) */
6110 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6111 } else if (!signal_mask_is_inited) {
6112 block_signals(0); /* 0: called 1st time */
6113 } /* else: block_signals(0) was done before */
6114 #elif ENABLE_HUSH_INTERACTIVE
6115 /* No job control compiled in, only prompt/line editing */
6116 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6117 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6118 if (G_interactive_fd < 0) {
6119 /* try to dup to any fd */
6120 G_interactive_fd = dup(STDIN_FILENO);
6121 if (G_interactive_fd < 0)
6123 G_interactive_fd = 0;
6126 if (G_interactive_fd) {
6127 close_on_exec_on(G_interactive_fd);
6128 block_signals(signal_mask_is_inited);
6129 } else if (!signal_mask_is_inited) {
6133 /* We have interactiveness code disabled */
6134 if (!signal_mask_is_inited) {
6139 * if interactive but not a login shell, sources ~/.bashrc
6140 * (--norc turns this off, --rcfile <file> overrides)
6143 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6144 printf("\n\n%s hush - the humble shell\n", bb_banner);
6145 printf("Enter 'help' for a list of built-in commands.\n\n");
6148 parse_and_run_file(stdin);
6151 #if ENABLE_FEATURE_CLEAN_UP
6152 if (G.cwd != bb_msg_unknown)
6154 cur_var = G.top_var->next;
6156 struct variable *tmp = cur_var;
6157 if (!cur_var->max_len)
6158 free(cur_var->varstr);
6159 cur_var = cur_var->next;
6163 hush_exit(G.last_exitcode);
6168 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6169 int lash_main(int argc, char **argv)
6171 //bb_error_msg("lash is deprecated, please use hush instead");
6172 return hush_main(argc, argv);
6180 static int builtin_trap(char **argv)
6187 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6191 /* No args: print all trapped. This isn't 100% correct as we
6192 * should be escaping the cmd so that it can be pasted back in
6194 for (i = 0; i < NSIG; ++i)
6196 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
6197 return EXIT_SUCCESS;
6202 /* If first arg is decimal: reset all specified signals */
6203 sig = bb_strtou(*argv, NULL, 10);
6209 sig = get_signum(*argv++);
6210 if (sig < 0 || sig >= NSIG) {
6212 /* Mimic bash message exactly */
6213 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
6218 G.traps[sig] = xstrdup(new_cmd);
6220 debug_printf("trap: setting SIG%s (%i) to '%s'",
6221 get_signame(sig), sig, G.traps[sig]);
6223 /* There is no signal for 0 (EXIT) */
6228 sigaddset(&G.blocked_set, sig);
6230 /* There was a trap handler, we are removing it
6231 * (if sig has non-DFL handling,
6232 * we don't need to do anything) */
6233 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6235 sigdelset(&G.blocked_set, sig);
6237 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6242 /* First arg is "-": reset all specified to default */
6243 /* First arg is "": ignore all specified */
6244 /* Everything else: execute first arg upon signal */
6246 bb_error_msg("trap: invalid arguments");
6247 return EXIT_FAILURE;
6249 if (NOT_LONE_DASH(*argv))
6255 static int builtin_true(char **argv UNUSED_PARAM)
6260 static int builtin_test(char **argv)
6267 return test_main(argc, argv - argc);
6270 static int builtin_echo(char **argv)
6277 return echo_main(argc, argv - argc);
6280 static int builtin_eval(char **argv)
6282 int rcode = EXIT_SUCCESS;
6285 char *str = expand_strvec_to_string(argv);
6287 * eval "echo Hi; done" ("done" is syntax error):
6288 * "echo Hi" will not execute too.
6290 parse_and_run_string(str);
6292 rcode = G.last_exitcode;
6297 static int builtin_cd(char **argv)
6299 const char *newdir = argv[1];
6300 if (newdir == NULL) {
6301 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6302 * bash says "bash: cd: HOME not set" and does nothing
6305 newdir = getenv("HOME") ? : "/";
6307 if (chdir(newdir)) {
6308 /* Mimic bash message exactly */
6309 bb_perror_msg("cd: %s", newdir);
6310 return EXIT_FAILURE;
6313 return EXIT_SUCCESS;
6316 static int builtin_exec(char **argv)
6318 if (*++argv == NULL)
6319 return EXIT_SUCCESS; /* bash does this */
6324 // FIXME: if exec fails, bash does NOT exit! We do...
6325 pseudo_exec_argv(&dummy, argv, 0, NULL);
6330 static int builtin_exit(char **argv)
6332 debug_printf_exec("%s()\n", __func__);
6333 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6334 //puts("exit"); /* bash does it */
6335 // TODO: warn if we have background jobs: "There are stopped jobs"
6336 // On second consecutive 'exit', exit anyway.
6337 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6339 /* note: EXIT trap is run by hush_exit */
6340 if (*++argv == NULL)
6341 hush_exit(G.last_exitcode);
6342 /* mimic bash: exit 123abc == exit 255 + error msg */
6343 xfunc_error_retval = 255;
6344 /* bash: exit -2 == exit 254, no error msg */
6345 hush_exit(xatoi(*argv) & 0xff);
6348 static int builtin_export(char **argv)
6350 if (*++argv == NULL) {
6357 /* ash emits: export VAR='VAL'
6358 * bash: declare -x VAR="VAL"
6359 * we follow ash example */
6360 const char *s = *e++;
6361 const char *p = strchr(s, '=');
6363 if (!p) /* wtf? take next variable */
6366 printf("export %.*s", (int)(p - s) + 1, s);
6370 p = strchrnul(s, '\'');
6372 printf("'%.*s'", (int)(p - s), s);
6377 /* s points to '; print ''...'''" */
6379 do putchar('\''); while (*++s == '\'');
6387 return EXIT_SUCCESS;
6394 value = strchr(name, '=');
6396 /* They are exporting something without a =VALUE */
6397 struct variable *var;
6399 var = get_local_var(name);
6401 var->flg_export = 1;
6402 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6403 putenv(var->varstr);
6405 /* bash does not return an error when trying to export
6406 * an undefined variable. Do likewise. */
6409 set_local_var(xstrdup(name), 1, 0);
6412 return EXIT_SUCCESS;
6416 /* built-in 'fg' and 'bg' handler */
6417 static int builtin_fg_bg(char **argv)
6422 if (!G_interactive_fd)
6423 return EXIT_FAILURE;
6424 /* If they gave us no args, assume they want the last backgrounded task */
6426 for (pi = G.job_list; pi; pi = pi->next) {
6427 if (pi->jobid == G.last_jobid) {
6431 bb_error_msg("%s: no current job", argv[0]);
6432 return EXIT_FAILURE;
6434 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6435 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6436 return EXIT_FAILURE;
6438 for (pi = G.job_list; pi; pi = pi->next) {
6439 if (pi->jobid == jobnum) {
6443 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6444 return EXIT_FAILURE;
6446 // TODO: bash prints a string representation
6447 // of job being foregrounded (like "sleep 1 | cat")
6448 if (argv[0][0] == 'f') {
6449 /* Put the job into the foreground. */
6450 tcsetpgrp(G_interactive_fd, pi->pgrp);
6453 /* Restart the processes in the job */
6454 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6455 for (i = 0; i < pi->num_cmds; i++) {
6456 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6457 pi->cmds[i].is_stopped = 0;
6459 pi->stopped_cmds = 0;
6461 i = kill(- pi->pgrp, SIGCONT);
6463 if (errno == ESRCH) {
6464 delete_finished_bg_job(pi);
6465 return EXIT_SUCCESS;
6467 bb_perror_msg("kill (SIGCONT)");
6470 if (argv[0][0] == 'f') {
6472 return checkjobs_and_fg_shell(pi);
6474 return EXIT_SUCCESS;
6478 #if ENABLE_HUSH_HELP
6479 static int builtin_help(char **argv UNUSED_PARAM)
6481 const struct built_in_command *x;
6484 "Built-in commands:\n"
6485 "------------------\n");
6486 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6487 printf("%s\t%s\n", x->cmd, x->descr);
6490 return EXIT_SUCCESS;
6495 static int builtin_jobs(char **argv UNUSED_PARAM)
6498 const char *status_string;
6500 for (job = G.job_list; job; job = job->next) {
6501 if (job->alive_cmds == job->stopped_cmds)
6502 status_string = "Stopped";
6504 status_string = "Running";
6506 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6508 return EXIT_SUCCESS;
6513 static int builtin_memleak(char **argv UNUSED_PARAM)
6518 /* Crude attempt to find where "free memory" starts,
6519 * sans fragmentation. */
6521 l = (unsigned long)p;
6524 if (l < (unsigned long)p) l = (unsigned long)p;
6527 if (!G.memleak_value)
6528 G.memleak_value = l;
6530 l -= G.memleak_value;
6537 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6542 static int builtin_pwd(char **argv UNUSED_PARAM)
6545 return EXIT_SUCCESS;
6548 static int builtin_read(char **argv)
6551 const char *name = "REPLY";
6555 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6556 * and _after_ that_ it will complain */
6557 if (!is_well_formed_var_name(name, '\0')) {
6558 /* Mimic bash message */
6559 bb_error_msg("read: '%s': not a valid identifier", name);
6564 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6566 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6567 return set_local_var(string, 0, 0);
6570 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6571 * built-in 'set' handler
6573 * set [-abCefhmnuvx] [-o option] [argument...]
6574 * set [+abCefhmnuvx] [+o option] [argument...]
6575 * set -- [argument...]
6578 * Implementations shall support the options in both their hyphen and
6579 * plus-sign forms. These options can also be specified as options to sh.
6581 * Write out all variables and their values: set
6582 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6583 * Turn on the -x and -v options: set -xv
6584 * Unset all positional parameters: set --
6585 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6586 * Set the positional parameters to the expansion of x, even if x expands
6587 * with a leading '-' or '+': set -- $x
6589 * So far, we only support "set -- [argument...]" and some of the short names.
6591 static int builtin_set(char **argv)
6594 char **pp, **g_argv;
6595 char *arg = *++argv;
6599 for (e = G.top_var; e; e = e->next)
6601 return EXIT_SUCCESS;
6605 if (!strcmp(arg, "--")) {
6609 if (arg[0] != '+' && arg[0] != '-')
6611 for (n = 1; arg[n]; ++n)
6612 if (set_mode(arg[0], arg[n]))
6614 } while ((arg = *++argv) != NULL);
6615 /* Now argv[0] is 1st argument */
6618 return EXIT_SUCCESS;
6621 /* NB: G.global_argv[0] ($0) is never freed/changed */
6622 g_argv = G.global_argv;
6623 if (G.global_args_malloced) {
6629 G.global_args_malloced = 1;
6630 pp = xzalloc(sizeof(pp[0]) * 2);
6631 pp[0] = g_argv[0]; /* retain $0 */
6634 /* This realloc's G.global_argv */
6635 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6642 return EXIT_SUCCESS;
6644 /* Nothing known, so abort */
6646 bb_error_msg("set: %s: invalid option", arg);
6647 return EXIT_FAILURE;
6650 static int builtin_shift(char **argv)
6656 if (n >= 0 && n < G.global_argc) {
6657 if (G.global_args_malloced) {
6660 free(G.global_argv[m++]);
6663 memmove(&G.global_argv[1], &G.global_argv[n+1],
6664 G.global_argc * sizeof(G.global_argv[0]));
6665 return EXIT_SUCCESS;
6667 return EXIT_FAILURE;
6670 static int builtin_source(char **argv)
6674 if (*++argv == NULL)
6675 return EXIT_FAILURE;
6677 /* XXX search through $PATH is missing */
6678 input = fopen_or_warn(*argv, "r");
6680 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6681 return EXIT_FAILURE;
6683 close_on_exec_on(fileno(input));
6685 /* Now run the file */
6687 /* XXX argv and argc are broken; need to save old G.global_argv
6688 * (pointer only is OK!) on this stack frame,
6689 * set G.global_argv=argv+1, recurse, and restore. */
6690 parse_and_run_file(input);
6692 return G.last_exitcode;
6695 static int builtin_umask(char **argv)
6698 const char *arg = argv[1];
6700 //TODO: umask may take chmod-like symbolic masks
6701 new_umask = bb_strtou(arg, NULL, 8);
6703 //Message? bash examples:
6704 //bash: umask: 'q': invalid symbolic mode operator
6705 //bash: umask: 999: octal number out of range
6706 return EXIT_FAILURE;
6709 new_umask = umask(0);
6710 printf("%.3o\n", (unsigned) new_umask);
6711 /* fall through and restore new_umask which we set to 0 */
6714 return EXIT_SUCCESS;
6717 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6718 static int builtin_unset(char **argv)
6724 return EXIT_SUCCESS;
6727 if (argv[0][0] == '-') {
6728 switch (argv[0][1]) {
6734 bb_error_msg("unset: %s: invalid option", *argv);
6735 return EXIT_FAILURE;
6737 //TODO: disallow "unset -vf ..." too
6744 if (unset_local_var(*argv)) {
6745 /* unset <nonexistent_var> doesn't fail.
6746 * Error is when one tries to unset RO var.
6747 * Message was printed by unset_local_var. */
6751 //#if ENABLE_HUSH_FUNCTIONS
6753 // unset_local_func(*argv);
6761 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6762 static int builtin_wait(char **argv)
6764 int ret = EXIT_SUCCESS;
6767 if (*++argv == NULL) {
6768 /* Don't care about wait results */
6769 /* Note 1: must wait until there are no more children */
6770 /* Note 2: must be interruptible */
6772 * $ sleep 3 & sleep 6 & wait
6777 * $ sleep 3 & sleep 6 & wait
6781 * ^C <-- after ~4 sec from keyboard
6784 sigaddset(&G.blocked_set, SIGCHLD);
6785 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6788 if (errno == ECHILD)
6790 /* Wait for SIGCHLD or any other signal of interest */
6791 /* sigtimedwait with infinite timeout: */
6792 sig = sigwaitinfo(&G.blocked_set, NULL);
6794 sig = check_and_run_traps(sig);
6795 if (sig && sig != SIGCHLD) { /* see note 2 */
6801 sigdelset(&G.blocked_set, SIGCHLD);
6802 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6806 /* This is probably buggy wrt interruptible-ness */
6808 pid_t pid = bb_strtou(*argv, NULL, 10);
6810 /* mimic bash message */
6811 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6812 return EXIT_FAILURE;
6814 if (waitpid(pid, &status, 0) == pid) {
6815 if (WIFSIGNALED(status))
6816 ret = 128 + WTERMSIG(status);
6817 else if (WIFEXITED(status))
6818 ret = WEXITSTATUS(status);
6822 bb_perror_msg("wait %s", *argv);
6831 #if ENABLE_HUSH_LOOPS
6832 static int builtin_break(char **argv)
6834 if (G.depth_of_loop == 0) {
6835 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6836 return EXIT_SUCCESS; /* bash compat */
6838 G.flag_break_continue++; /* BC_BREAK = 1 */
6839 G.depth_break_continue = 1;
6841 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6842 if (errno || !G.depth_break_continue || argv[2]) {
6843 bb_error_msg("%s: bad arguments", argv[0]);
6844 G.flag_break_continue = BC_BREAK;
6845 G.depth_break_continue = UINT_MAX;
6848 if (G.depth_of_loop < G.depth_break_continue)
6849 G.depth_break_continue = G.depth_of_loop;
6850 return EXIT_SUCCESS;
6853 static int builtin_continue(char **argv)
6855 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6856 return builtin_break(argv);