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) */
2469 bb_perror_msg_and_die("vfork");
2472 disable_restore_tty_pgrp_on_exit();
2473 pid = BB_MMU ? fork() : vfork();
2475 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2479 close(redir->rd_fd); /* read side of the pipe */
2481 full_write(pair.wr, heredoc, len); /* may loop or block */
2484 /* Delegate blocking writes to another process */
2485 xmove_fd(pair.wr, STDOUT_FILENO);
2486 re_execute_shell(&to_free, heredoc, NULL, NULL);
2490 enable_restore_tty_pgrp_on_exit();
2496 wait(NULL); /* wait till child has died */
2499 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2500 * and stderr if they are redirected. */
2501 static int setup_redirects(struct command *prog, int squirrel[])
2504 struct redir_struct *redir;
2506 for (redir = prog->redirects; redir; redir = redir->next) {
2507 if (redir->rd_type == REDIRECT_HEREDOC2) {
2508 /* rd_fd<<HERE case */
2509 if (squirrel && redir->rd_fd < 3) {
2510 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2512 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2514 debug_printf_parse("set heredoc '%s'\n",
2515 redir->rd_filename);
2516 setup_heredoc(redir);
2520 if (redir->rd_dup == REDIRFD_TO_FILE) {
2521 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2523 if (redir->rd_filename == NULL) {
2524 /* Something went wrong in the parse.
2525 * Pretend it didn't happen */
2526 bb_error_msg("bug in redirect parse");
2529 mode = redir_table[redir->rd_type].mode;
2530 p = expand_string_to_string(redir->rd_filename);
2531 openfd = open_or_warn(p, mode);
2534 /* this could get lost if stderr has been redirected, but
2535 * bash and ash both lose it as well (though zsh doesn't!) */
2536 //what the above comment tries to say?
2540 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2541 openfd = redir->rd_dup;
2544 if (openfd != redir->rd_fd) {
2545 if (squirrel && redir->rd_fd < 3) {
2546 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2548 if (openfd == REDIRFD_CLOSE) {
2549 /* "n>-" means "close me" */
2550 close(redir->rd_fd);
2552 xdup2(openfd, redir->rd_fd);
2553 if (redir->rd_dup == REDIRFD_TO_FILE)
2561 static void restore_redirects(int squirrel[])
2564 for (i = 0; i < 3; i++) {
2567 /* We simply die on error */
2574 static void free_pipe_list(struct pipe *head);
2576 /* Return code is the exit status of the pipe */
2577 static void free_pipe(struct pipe *pi)
2580 struct command *command;
2581 struct redir_struct *r, *rnext;
2584 if (pi->stopped_cmds > 0) /* why? */
2586 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2587 for (i = 0; i < pi->num_cmds; i++) {
2588 command = &pi->cmds[i];
2589 debug_printf_clean(" command %d:\n", i);
2590 if (command->argv) {
2591 for (a = 0, p = command->argv; *p; a++, p++) {
2592 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2594 free_strings(command->argv);
2595 command->argv = NULL;
2597 /* not "else if": on syntax error, we may have both! */
2598 if (command->group) {
2599 debug_printf_clean(" begin group (grp_type:%d)\n",
2601 free_pipe_list(command->group);
2602 debug_printf_clean(" end group\n");
2603 command->group = NULL;
2605 /* else is crucial here.
2606 * If group != NULL, child_func is meaningless */
2607 #if ENABLE_HUSH_FUNCTIONS
2608 else if (command->child_func) {
2609 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2610 command->child_func->parent_cmd = NULL;
2614 free(command->group_as_string);
2615 command->group_as_string = NULL;
2617 for (r = command->redirects; r; r = rnext) {
2618 debug_printf_clean(" redirect %d%s",
2619 r->rd_fd, redir_table[r->rd_type].descrip);
2620 /* guard against the case >$FOO, where foo is unset or blank */
2621 if (r->rd_filename) {
2622 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2623 free(r->rd_filename);
2624 r->rd_filename = NULL;
2626 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2630 command->redirects = NULL;
2632 free(pi->cmds); /* children are an array, they get freed all at once */
2640 static void free_pipe_list(struct pipe *head)
2642 struct pipe *pi, *next;
2644 for (pi = head; pi; pi = next) {
2646 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2649 debug_printf_clean("pipe followup code %d\n", pi->followup);
2651 /*pi->next = NULL;*/
2657 static int run_list(struct pipe *pi);
2659 #define parse_stream(pstring, input, end_trigger) \
2660 parse_stream(input, end_trigger)
2662 static struct pipe *parse_stream(char **pstring,
2663 struct in_str *input,
2665 static void parse_and_run_string(const char *s);
2668 static const struct built_in_command* find_builtin(const char *name)
2670 const struct built_in_command *x;
2671 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2672 if (strcmp(name, x->cmd) != 0)
2674 debug_printf_exec("found builtin '%s'\n", name);
2680 #if ENABLE_HUSH_FUNCTIONS
2681 static const struct function *find_function(const char *name)
2683 const struct function *funcp = G.top_func;
2685 if (strcmp(name, funcp->name) == 0) {
2688 funcp = funcp->next;
2690 debug_printf_exec("found function '%s'\n", name);
2694 /* Note: takes ownership on name ptr */
2695 static struct function *new_function(char *name)
2697 struct function *funcp;
2698 struct function **funcpp = &G.top_func;
2700 while ((funcp = *funcpp) != NULL) {
2701 struct command *cmd;
2703 if (strcmp(funcp->name, name) != 0) {
2704 funcpp = &funcp->next;
2708 cmd = funcp->parent_cmd;
2709 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2711 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2713 /* Note: if !funcp->body, do not free body_as_string!
2714 * This is a special case of "-F name body" function:
2715 * body_as_string was not malloced! */
2717 free_pipe_list(funcp->body);
2719 free(funcp->body_as_string);
2723 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2724 cmd->argv[0] = funcp->name;
2725 cmd->group = funcp->body;
2727 cmd->group_as_string = funcp->body_as_string;
2732 debug_printf_exec("remembering new function '%s'\n", command->argv[0]);
2733 funcp = *funcpp = xzalloc(sizeof(*funcp));
2734 /*funcp->next = NULL;*/
2741 #define exec_function(nommu_save, funcp, argv) \
2742 exec_function(funcp, argv)
2744 static void exec_function(nommu_save_t *nommu_save,
2745 const struct function *funcp,
2746 char **argv) NORETURN;
2747 static void exec_function(nommu_save_t *nommu_save,
2748 const struct function *funcp,
2754 argv[0] = G.global_argv[0];
2755 G.global_argv = argv;
2759 /* On MMU, funcp->body is always non-NULL */
2760 n = run_list(funcp->body);
2764 re_execute_shell(&nommu_save->argv_from_re_execing,
2765 funcp->body_as_string,
2771 static int run_function(const struct function *funcp, char **argv)
2776 smallint sv_g_malloced;
2781 sv_g_malloced = G.global_args_malloced;
2782 sv_g_argc = G.global_argc;
2783 sv_g_argv = G.global_argv;
2790 argv[0] = G.global_argv[0]; /* retain $0 */
2791 G.global_args_malloced = 0;
2793 G.global_argv = argv;
2795 /* On MMU, funcp->body is always non-NULL */
2798 /* Function defined by -F */
2799 parse_and_run_string(funcp->body_as_string);
2800 n = G.last_exitcode;
2804 n = run_list(funcp->body);
2807 if (G.global_args_malloced) {
2808 /* function ran "set -- arg1 arg2 ..." */
2812 free(G.global_argv);
2816 G.global_args_malloced = sv_g_malloced;
2817 G.global_argc = sv_g_argc;
2818 G.global_argv = sv_g_argv;
2826 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2827 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2828 #define pseudo_exec(nommu_save, command, argv_expanded) \
2829 pseudo_exec(command, argv_expanded)
2832 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2834 * XXX no exit() here. If you don't exec, use _exit instead.
2835 * The at_exit handlers apparently confuse the calling process,
2836 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2837 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2838 char **argv, int assignment_cnt,
2839 char **argv_expanded) NORETURN;
2840 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2841 char **argv, int assignment_cnt,
2842 char **argv_expanded)
2846 /* Case when we are here: ... | var=val | ... */
2847 if (!argv[assignment_cnt])
2848 _exit(EXIT_SUCCESS);
2850 new_env = expand_assignments(argv, assignment_cnt);
2852 putenv_all(new_env);
2853 free(new_env); /* optional */
2855 nommu_save->new_env = new_env;
2856 nommu_save->old_env = putenv_all_and_save_old(new_env);
2858 if (argv_expanded) {
2859 argv = argv_expanded;
2861 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2863 nommu_save->argv = argv;
2867 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2868 if (strchr(argv[0], '/') != NULL)
2872 /* On NOMMU, we must never block!
2873 * Example: { sleep 99999 | read line } & echo Ok
2874 * read builtin will block on read syscall, leaving parent blocked
2875 * in vfork. Therefore we can't do this:
2878 /* Check if the command matches any of the builtins.
2879 * Depending on context, this might be redundant. But it's
2880 * easier to waste a few CPU cycles than it is to figure out
2881 * if this is one of those cases.
2885 const struct built_in_command *x = find_builtin(argv[0]);
2887 rcode = x->function(argv);
2893 #if ENABLE_HUSH_FUNCTIONS
2894 /* Check if the command matches any functions */
2896 const struct function *funcp = find_function(argv[0]);
2898 exec_function(nommu_save, funcp, argv);
2903 #if ENABLE_FEATURE_SH_STANDALONE
2904 /* Check if the command matches any busybox applets */
2906 int a = find_applet_by_name(argv[0]);
2908 # if BB_MMU /* see above why on NOMMU it is not allowed */
2909 if (APPLET_IS_NOEXEC(a)) {
2910 debug_printf_exec("running applet '%s'\n", argv[0]);
2911 run_applet_no_and_exit(a, argv);
2914 /* Re-exec ourselves */
2915 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2916 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2917 execv(bb_busybox_exec_path, argv);
2918 /* If they called chroot or otherwise made the binary no longer
2919 * executable, fall through */
2924 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2927 debug_printf_exec("execing '%s'\n", argv[0]);
2928 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2929 execvp(argv[0], argv);
2930 bb_perror_msg("can't exec '%s'", argv[0]);
2931 _exit(EXIT_FAILURE);
2934 /* Called after [v]fork() in run_pipe
2936 static void pseudo_exec(nommu_save_t *nommu_save,
2937 struct command *command,
2938 char **argv_expanded) NORETURN;
2939 static void pseudo_exec(nommu_save_t *nommu_save,
2940 struct command *command,
2941 char **argv_expanded)
2943 if (command->argv) {
2944 pseudo_exec_argv(nommu_save, command->argv,
2945 command->assignment_cnt, argv_expanded);
2948 if (command->group) {
2949 /* Cases when we are here:
2952 * ... | ( list ) | ...
2953 * ... | { list } | ...
2957 debug_printf_exec("pseudo_exec: run_list\n");
2958 reset_traps_to_defaults();
2959 rcode = run_list(command->group);
2960 /* OK to leak memory by not calling free_pipe_list,
2961 * since this process is about to exit */
2964 re_execute_shell(&nommu_save->argv_from_re_execing,
2965 command->group_as_string,
2971 /* Case when we are here: ... | >file */
2972 debug_printf_exec("pseudo_exec'ed null command\n");
2973 _exit(EXIT_SUCCESS);
2977 static const char *get_cmdtext(struct pipe *pi)
2983 /* This is subtle. ->cmdtext is created only on first backgrounding.
2984 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2985 * On subsequent bg argv is trashed, but we won't use it */
2988 argv = pi->cmds[0].argv;
2989 if (!argv || !argv[0]) {
2990 pi->cmdtext = xzalloc(1);
2995 do len += strlen(*argv) + 1; while (*++argv);
2996 pi->cmdtext = p = xmalloc(len);
2997 argv = pi->cmds[0].argv;
2999 len = strlen(*argv);
3000 memcpy(p, *argv, len);
3008 static void insert_bg_job(struct pipe *pi)
3010 struct pipe *thejob;
3013 /* Linear search for the ID of the job to use */
3015 for (thejob = G.job_list; thejob; thejob = thejob->next)
3016 if (thejob->jobid >= pi->jobid)
3017 pi->jobid = thejob->jobid + 1;
3019 /* Add thejob to the list of running jobs */
3021 thejob = G.job_list = xmalloc(sizeof(*thejob));
3023 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
3025 thejob->next = xmalloc(sizeof(*thejob));
3026 thejob = thejob->next;
3029 /* Physically copy the struct job */
3030 memcpy(thejob, pi, sizeof(struct pipe));
3031 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3032 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
3033 for (i = 0; i < pi->num_cmds; i++) {
3034 // TODO: do we really need to have so many fields which are just dead weight
3035 // at execution stage?
3036 thejob->cmds[i].pid = pi->cmds[i].pid;
3037 /* all other fields are not used and stay zero */
3039 thejob->next = NULL;
3040 thejob->cmdtext = xstrdup(get_cmdtext(pi));
3042 /* We don't wait for background thejobs to return -- append it
3043 to the list of backgrounded thejobs and leave it alone */
3044 if (G_interactive_fd)
3045 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
3046 G.last_bg_pid = thejob->cmds[0].pid;
3047 G.last_jobid = thejob->jobid;
3050 static void remove_bg_job(struct pipe *pi)
3052 struct pipe *prev_pipe;
3054 if (pi == G.job_list) {
3055 G.job_list = pi->next;
3057 prev_pipe = G.job_list;
3058 while (prev_pipe->next != pi)
3059 prev_pipe = prev_pipe->next;
3060 prev_pipe->next = pi->next;
3063 G.last_jobid = G.job_list->jobid;
3068 /* Remove a backgrounded job */
3069 static void delete_finished_bg_job(struct pipe *pi)
3072 pi->stopped_cmds = 0;
3078 /* Check to see if any processes have exited -- if they
3079 * have, figure out why and see if a job has completed */
3080 static int checkjobs(struct pipe* fg_pipe)
3090 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3093 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3094 // /* avoid doing syscall, nothing there anyway */
3097 attributes = WUNTRACED;
3098 if (fg_pipe == NULL)
3099 attributes |= WNOHANG;
3101 /* Do we do this right?
3102 * bash-3.00# sleep 20 | false
3104 * [3]+ Stopped sleep 20 | false
3105 * bash-3.00# echo $?
3106 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3109 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
3110 //are stopped. Testcase: "cat | cat" in a script (not on command line)
3111 // + killall -STOP cat
3118 // i = G.count_SIGCHLD;
3119 childpid = waitpid(-1, &status, attributes);
3120 if (childpid <= 0) {
3121 if (childpid && errno != ECHILD)
3122 bb_perror_msg("waitpid");
3123 // else /* Until next SIGCHLD, waitpid's are useless */
3124 // G.handled_SIGCHLD = i;
3127 dead = WIFEXITED(status) || WIFSIGNALED(status);
3130 if (WIFSTOPPED(status))
3131 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3132 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3133 if (WIFSIGNALED(status))
3134 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3135 childpid, WTERMSIG(status), WEXITSTATUS(status));
3136 if (WIFEXITED(status))
3137 debug_printf_jobs("pid %d exited, exitcode %d\n",
3138 childpid, WEXITSTATUS(status));
3140 /* Were we asked to wait for fg pipe? */
3142 for (i = 0; i < fg_pipe->num_cmds; i++) {
3143 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3144 if (fg_pipe->cmds[i].pid != childpid)
3146 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
3148 fg_pipe->cmds[i].pid = 0;
3149 fg_pipe->alive_cmds--;
3150 if (i == fg_pipe->num_cmds - 1) {
3151 /* last process gives overall exitstatus */
3152 rcode = WEXITSTATUS(status);
3153 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3156 fg_pipe->cmds[i].is_stopped = 1;
3157 fg_pipe->stopped_cmds++;
3159 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3160 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3161 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3162 /* All processes in fg pipe have exited/stopped */
3164 if (fg_pipe->alive_cmds)
3165 insert_bg_job(fg_pipe);
3169 /* There are still running processes in the fg pipe */
3170 goto wait_more; /* do waitpid again */
3172 /* it wasnt fg_pipe, look for process in bg pipes */
3176 /* We asked to wait for bg or orphaned children */
3177 /* No need to remember exitcode in this case */
3178 for (pi = G.job_list; pi; pi = pi->next) {
3179 for (i = 0; i < pi->num_cmds; i++) {
3180 if (pi->cmds[i].pid == childpid)
3181 goto found_pi_and_prognum;
3184 /* Happens when shell is used as init process (init=/bin/sh) */
3185 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3186 continue; /* do waitpid again */
3188 found_pi_and_prognum:
3191 pi->cmds[i].pid = 0;
3193 if (!pi->alive_cmds) {
3194 if (G_interactive_fd)
3195 printf(JOB_STATUS_FORMAT, pi->jobid,
3196 "Done", pi->cmdtext);
3197 delete_finished_bg_job(pi);
3201 pi->cmds[i].is_stopped = 1;
3205 } /* while (waitpid succeeds)... */
3211 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3214 int rcode = checkjobs(fg_pipe);
3215 /* Job finished, move the shell to the foreground */
3216 p = getpgid(0); /* pgid of our process */
3217 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3218 tcsetpgrp(G_interactive_fd, p);
3223 /* Start all the jobs, but don't wait for anything to finish.
3226 * Return code is normally -1, when the caller has to wait for children
3227 * to finish to determine the exit status of the pipe. If the pipe
3228 * is a simple builtin command, however, the action is done by the
3229 * time run_pipe returns, and the exit code is provided as the
3232 * Returns -1 only if started some children. IOW: we have to
3233 * mask out retvals of builtins etc with 0xff!
3235 * The only case when we do not need to [v]fork is when the pipe
3236 * is single, non-backgrounded, non-subshell command. Examples:
3237 * cmd ; ... { list } ; ...
3238 * cmd && ... { list } && ...
3239 * cmd || ... { list } || ...
3240 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3241 * or (if SH_STANDALONE) an applet, and we can run the { list }
3242 * with run_list(). If it isn't one of these, we fork and exec cmd.
3244 * Cases when we must fork:
3245 * non-single: cmd | cmd
3246 * backgrounded: cmd & { list } &
3247 * subshell: ( list ) [&]
3249 static int run_pipe(struct pipe *pi)
3251 static const char *const null_ptr = NULL;
3254 int pipefds[2]; /* pipefds[0] is for reading */
3255 struct command *command;
3256 char **argv_expanded;
3259 /* it is not always needed, but we aim to smaller code */
3260 int squirrel[] = { -1, -1, -1 };
3263 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3266 USE_HUSH_JOB(pi->pgrp = -1;)
3267 pi->stopped_cmds = 0;
3268 command = &(pi->cmds[0]);
3269 argv_expanded = NULL;
3271 if (pi->num_cmds != 1
3272 || pi->followup == PIPE_BG
3273 || command->grp_type == GRP_SUBSHELL
3280 debug_printf_exec(": group:%p argv:'%s'\n",
3281 command->group, command->argv ? command->argv[0] : "NONE");
3283 if (command->group) {
3284 #if ENABLE_HUSH_FUNCTIONS
3285 if (command->grp_type == GRP_FUNCTION) {
3286 /* "executing" func () { list } */
3287 struct function *funcp;
3289 funcp = new_function(command->argv[0]);
3290 /* funcp->name is already set to argv[0] */
3291 funcp->body = command->group;
3293 funcp->body_as_string = command->group_as_string;
3294 command->group_as_string = NULL;
3296 command->group = NULL;
3297 command->argv[0] = NULL;
3298 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3299 funcp->parent_cmd = command;
3300 command->child_func = funcp;
3302 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3304 return EXIT_SUCCESS;
3308 debug_printf("non-subshell group\n");
3309 rcode = 1; /* exitcode if redir failed */
3310 if (setup_redirects(command, squirrel) == 0) {
3311 debug_printf_exec(": run_list\n");
3312 rcode = run_list(command->group) & 0xff;
3314 restore_redirects(squirrel);
3315 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3317 debug_printf_exec("run_pipe: return %d\n", rcode);
3321 argv = command->argv ? command->argv : (char **) &null_ptr;
3323 const struct built_in_command *x;
3324 #if ENABLE_HUSH_FUNCTIONS
3325 const struct function *funcp;
3329 char **new_env = NULL;
3330 char **old_env = NULL;
3332 if (argv[command->assignment_cnt] == NULL) {
3333 /* Assignments, but no command */
3334 /* Ensure redirects take effect. Try "a=t >file" */
3335 rcode = setup_redirects(command, squirrel);
3336 restore_redirects(squirrel);
3337 /* Set shell variables */
3339 p = expand_string_to_string(*argv);
3340 debug_printf_exec("set shell var:'%s'->'%s'\n",
3342 set_local_var(p, 0, 0);
3345 /* Do we need to flag set_local_var() errors?
3346 * "assignment to readonly var" and "putenv error"
3348 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3350 debug_printf_exec("run_pipe: return %d\n", rcode);
3354 /* Expand the rest into (possibly) many strings each */
3355 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3357 x = find_builtin(argv_expanded[0]);
3358 #if ENABLE_HUSH_FUNCTIONS
3361 funcp = find_function(argv_expanded[0]);
3365 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3366 debug_printf("exec with redirects only\n");
3367 rcode = setup_redirects(command, NULL);
3368 goto clean_up_and_ret1;
3371 /* XXX setup_redirects acts on file descriptors, not FILEs.
3372 * This is perfect for work that comes after exec().
3373 * Is it really safe for inline use? Experimentally,
3374 * things seem to work with glibc. */
3375 rcode = setup_redirects(command, squirrel);
3377 new_env = expand_assignments(argv, command->assignment_cnt);
3378 old_env = putenv_all_and_save_old(new_env);
3380 debug_printf_exec(": builtin '%s' '%s'...\n",
3381 x->cmd, argv_expanded[1]);
3382 rcode = x->function(argv_expanded) & 0xff;
3384 #if ENABLE_HUSH_FUNCTIONS
3386 debug_printf_exec(": function '%s' '%s'...\n",
3387 funcp->name, argv_expanded[1]);
3388 rcode = run_function(funcp, argv_expanded) & 0xff;
3392 #if ENABLE_FEATURE_SH_STANDALONE
3395 restore_redirects(squirrel);
3396 free_strings_and_unsetenv(new_env, 1);
3397 putenv_all(old_env);
3398 /* Free the pointers, but the strings themselves
3399 * are in environ now, don't use free_strings! */
3402 free(argv_expanded);
3403 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3405 debug_printf_exec("run_pipe return %d\n", rcode);
3409 #if ENABLE_FEATURE_SH_STANDALONE
3410 i = find_applet_by_name(argv_expanded[0]);
3411 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3412 rcode = setup_redirects(command, squirrel);
3414 save_nofork_data(&G.nofork_save);
3415 new_env = expand_assignments(argv, command->assignment_cnt);
3416 old_env = putenv_all_and_save_old(new_env);
3417 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3418 argv_expanded[0], argv_expanded[1]);
3419 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3421 goto clean_up_and_ret;
3424 /* It is neither builtin nor applet. We must fork. */
3428 /* NB: argv_expanded may already be created, and that
3429 * might include `cmd` runs! Do not rerun it! We *must*
3430 * use argv_expanded if it's non-NULL */
3432 /* Going to fork a child per each pipe member */
3436 for (i = 0; i < pi->num_cmds; i++) {
3438 volatile nommu_save_t nommu_save;
3439 nommu_save.new_env = NULL;
3440 nommu_save.old_env = NULL;
3441 nommu_save.argv = NULL;
3442 nommu_save.argv_from_re_execing = NULL;
3444 command = &(pi->cmds[i]);
3445 if (command->argv) {
3446 debug_printf_exec(": pipe member '%s' '%s'...\n",
3447 command->argv[0], command->argv[1]);
3449 debug_printf_exec(": pipe member with no argv\n");
3452 /* pipes are inserted between pairs of commands */
3455 if ((i + 1) < pi->num_cmds)
3458 command->pid = BB_MMU ? fork() : vfork();
3459 if (!command->pid) { /* child */
3461 disable_restore_tty_pgrp_on_exit();
3463 /* Every child adds itself to new process group
3464 * with pgid == pid_of_first_child_in_pipe */
3465 if (G.run_list_level == 1 && G_interactive_fd) {
3468 if (pgrp < 0) /* true for 1st process only */
3470 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3471 /* We do it in *every* child, not just first,
3473 tcsetpgrp(G_interactive_fd, pgrp);
3477 xmove_fd(nextin, 0);
3478 xmove_fd(pipefds[1], 1); /* write end */
3480 close(pipefds[0]); /* read end */
3481 /* Like bash, explicit redirects override pipes,
3482 * and the pipe fd is available for dup'ing. */
3483 if (setup_redirects(command, NULL))
3486 /* Restore default handlers just prior to exec */
3487 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3489 /* Stores to nommu_save list of env vars putenv'ed
3490 * (NOMMU, on MMU we don't need that) */
3491 /* cast away volatility... */
3492 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3493 /* pseudo_exec() does not return */
3496 /* parent or error */
3497 enable_restore_tty_pgrp_on_exit();
3499 /* Clean up after vforked child */
3500 free(nommu_save.argv);
3501 free(nommu_save.argv_from_re_execing);
3502 free_strings_and_unsetenv(nommu_save.new_env, 1);
3503 putenv_all(nommu_save.old_env);
3504 /* Free the pointers, but the strings themselves
3505 * are in environ now, don't use free_strings! */
3506 free(nommu_save.old_env);
3508 free(argv_expanded);
3509 argv_expanded = NULL;
3510 if (command->pid < 0) { /* [v]fork failed */
3511 /* Clearly indicate, was it fork or vfork */
3512 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3516 /* Second and next children need to know pid of first one */
3518 pi->pgrp = command->pid;
3524 if ((i + 1) < pi->num_cmds)
3525 close(pipefds[1]); /* write end */
3526 /* Pass read (output) pipe end to next iteration */
3527 nextin = pipefds[0];
3530 if (!pi->alive_cmds) {
3532 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3537 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3541 #ifndef debug_print_tree
3542 static void debug_print_tree(struct pipe *pi, int lvl)
3544 static const char *const PIPE[] = {
3550 static const char *RES[] = {
3551 [RES_NONE ] = "NONE" ,
3554 [RES_THEN ] = "THEN" ,
3555 [RES_ELIF ] = "ELIF" ,
3556 [RES_ELSE ] = "ELSE" ,
3559 #if ENABLE_HUSH_LOOPS
3560 [RES_FOR ] = "FOR" ,
3561 [RES_WHILE] = "WHILE",
3562 [RES_UNTIL] = "UNTIL",
3564 [RES_DONE ] = "DONE" ,
3566 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3569 #if ENABLE_HUSH_CASE
3570 [RES_CASE ] = "CASE" ,
3571 [RES_MATCH] = "MATCH",
3572 [RES_CASEI] = "CASEI",
3573 [RES_ESAC ] = "ESAC" ,
3575 [RES_XXXX ] = "XXXX" ,
3576 [RES_SNTX ] = "SNTX" ,
3578 static const char *const GRPTYPE[] = {
3581 #if ENABLE_HUSH_FUNCTIONS
3590 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3591 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3593 while (prn < pi->num_cmds) {
3594 struct command *command = &pi->cmds[prn];
3595 char **argv = command->argv;
3597 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3599 command->assignment_cnt);
3600 if (command->group) {
3601 fprintf(stderr, " group %s: (argv=%p)\n",
3602 GRPTYPE[command->grp_type],
3604 debug_print_tree(command->group, lvl+1);
3608 if (argv) while (*argv) {
3609 fprintf(stderr, " '%s'", *argv);
3612 fprintf(stderr, "\n");
3621 /* NB: called by pseudo_exec, and therefore must not modify any
3622 * global data until exec/_exit (we can be a child after vfork!) */
3623 static int run_list(struct pipe *pi)
3625 #if ENABLE_HUSH_CASE
3626 char *case_word = NULL;
3628 #if ENABLE_HUSH_LOOPS
3629 struct pipe *loop_top = NULL;
3630 char *for_varname = NULL;
3631 char **for_lcur = NULL;
3632 char **for_list = NULL;
3634 smallint last_followup;
3636 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3637 smalluint cond_code = 0;
3639 enum { cond_code = 0 };
3642 smallint rword; /* enum reserved_style */
3643 smallint last_rword; /* ditto */
3646 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3649 #if ENABLE_HUSH_LOOPS
3650 /* Check syntax for "for" */
3651 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3652 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3654 /* current word is FOR or IN (BOLD in comments below) */
3655 if (cpipe->next == NULL) {
3656 syntax_error("malformed for");
3658 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3661 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3662 if (cpipe->next->res_word == RES_DO)
3664 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3665 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3666 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3668 syntax_error("malformed for");
3670 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3676 /* Past this point, all code paths should jump to ret: label
3677 * in order to return, no direct "return" statements please.
3678 * This helps to ensure that no memory is leaked. */
3680 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3683 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3684 * We are saving state before entering outermost list ("while...done")
3685 * so that ctrl-Z will correctly background _entire_ outermost list,
3686 * not just a part of it (like "sleep 1 | exit 2") */
3687 if (++G.run_list_level == 1 && G_interactive_fd) {
3688 if (sigsetjmp(G.toplevel_jb, 1)) {
3689 /* ctrl-Z forked and we are parent; or ctrl-C.
3690 * Sighandler has longjmped us here */
3691 signal(SIGINT, SIG_IGN);
3692 signal(SIGTSTP, SIG_IGN);
3693 /* Restore level (we can be coming from deep inside
3695 G.run_list_level = 1;
3696 #if ENABLE_FEATURE_SH_STANDALONE
3697 if (G.nofork_save.saved) { /* if save area is valid */
3698 debug_printf_jobs("exiting nofork early\n");
3699 restore_nofork_data(&G.nofork_save);
3702 //// if (G.ctrl_z_flag) {
3703 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3704 //// * Remember this child as background job */
3705 //// insert_bg_job(pi);
3707 /* ctrl-C. We just stop doing whatever we were doing */
3710 USE_HUSH_LOOPS(loop_top = NULL;)
3711 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3715 //// /* ctrl-Z handler will store pid etc in pi */
3716 //// G.toplevel_list = pi;
3717 //// G.ctrl_z_flag = 0;
3718 #if ENABLE_FEATURE_SH_STANDALONE
3719 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3721 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3722 //// signal(SIGINT, handler_ctrl_c);
3728 last_rword = RES_XXXX;
3730 last_followup = PIPE_SEQ;
3731 rcode = G.last_exitcode;
3733 /* Go through list of pipes, (maybe) executing them. */
3734 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3738 IF_HAS_KEYWORDS(rword = pi->res_word;)
3739 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3740 rword, cond_code, last_rword);
3741 #if ENABLE_HUSH_LOOPS
3742 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3743 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3745 /* start of a loop: remember where loop starts */
3750 /* Still in the same "if...", "then..." or "do..." branch? */
3751 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3752 if ((rcode == 0 && last_followup == PIPE_OR)
3753 || (rcode != 0 && last_followup == PIPE_AND)
3755 /* It is "<true> || CMD" or "<false> && CMD"
3756 * and we should not execute CMD */
3757 debug_printf_exec("skipped cmd because of || or &&\n");
3758 last_followup = pi->followup;
3762 last_followup = pi->followup;
3763 IF_HAS_KEYWORDS(last_rword = rword;)
3766 if (rword == RES_THEN) {
3767 /* if false; then ... fi has exitcode 0! */
3768 G.last_exitcode = rcode = EXIT_SUCCESS;
3769 /* "if <false> THEN cmd": skip cmd */
3773 if (rword == RES_ELSE || rword == RES_ELIF) {
3774 /* "if <true> then ... ELSE/ELIF cmd":
3775 * skip cmd and all following ones */
3780 #if ENABLE_HUSH_LOOPS
3781 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3783 /* first loop through for */
3785 static const char encoded_dollar_at[] ALIGN1 = {
3786 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3787 }; /* encoded representation of "$@" */
3788 static const char *const encoded_dollar_at_argv[] = {
3789 encoded_dollar_at, NULL
3790 }; /* argv list with one element: "$@" */
3793 vals = (char**)encoded_dollar_at_argv;
3794 if (pi->next->res_word == RES_IN) {
3795 /* if no variable values after "in" we skip "for" */
3796 if (!pi->next->cmds[0].argv) {
3797 G.last_exitcode = rcode = EXIT_SUCCESS;
3798 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3801 vals = pi->next->cmds[0].argv;
3802 } /* else: "for var; do..." -> assume "$@" list */
3803 /* create list of variable values */
3804 debug_print_strings("for_list made from", vals);
3805 for_list = expand_strvec_to_strvec(vals);
3806 for_lcur = for_list;
3807 debug_print_strings("for_list", for_list);
3808 for_varname = pi->cmds[0].argv[0];
3809 pi->cmds[0].argv[0] = NULL;
3811 free(pi->cmds[0].argv[0]);
3813 /* "for" loop is over, clean up */
3817 pi->cmds[0].argv[0] = for_varname;
3820 /* Insert next value from for_lcur */
3821 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3822 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3823 pi->cmds[0].assignment_cnt = 1;
3825 if (rword == RES_IN) {
3826 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3828 if (rword == RES_DONE) {
3829 continue; /* "done" has no cmds too */
3832 #if ENABLE_HUSH_CASE
3833 if (rword == RES_CASE) {
3834 case_word = expand_strvec_to_string(pi->cmds->argv);
3837 if (rword == RES_MATCH) {
3840 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3842 /* all prev words didn't match, does this one match? */
3843 argv = pi->cmds->argv;
3845 char *pattern = expand_string_to_string(*argv);
3846 /* TODO: which FNM_xxx flags to use? */
3847 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3849 if (cond_code == 0) { /* match! we will execute this branch */
3850 free(case_word); /* make future "word)" stop */
3858 if (rword == RES_CASEI) { /* inside of a case branch */
3860 continue; /* not matched yet, skip this pipe */
3863 /* Just pressing <enter> in shell should check for jobs.
3864 * OTOH, in non-interactive shell this is useless
3865 * and only leads to extra job checks */
3866 if (pi->num_cmds == 0) {
3867 if (G_interactive_fd)
3868 goto check_jobs_and_continue;
3872 /* After analyzing all keywords and conditions, we decided
3873 * to execute this pipe. NB: have to do checkjobs(NULL)
3874 * after run_pipe to collect any background children,
3875 * even if list execution is to be stopped. */
3876 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3879 #if ENABLE_HUSH_LOOPS
3880 G.flag_break_continue = 0;
3882 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3884 /* We only ran a builtin: rcode is already known
3885 * and we don't need to wait for anything. */
3886 G.last_exitcode = rcode;
3887 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3888 check_and_run_traps(0);
3889 #if ENABLE_HUSH_LOOPS
3890 /* Was it "break" or "continue"? */
3891 if (G.flag_break_continue) {
3892 smallint fbc = G.flag_break_continue;
3893 /* We might fall into outer *loop*,
3894 * don't want to break it too */
3896 G.depth_break_continue--;
3897 if (G.depth_break_continue == 0)
3898 G.flag_break_continue = 0;
3899 /* else: e.g. "continue 2" should *break* once, *then* continue */
3900 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3901 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3902 goto check_jobs_and_break;
3903 /* "continue": simulate end of loop */
3908 } else if (pi->followup == PIPE_BG) {
3909 /* What does bash do with attempts to background builtins? */
3910 /* even bash 3.2 doesn't do that well with nested bg:
3911 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3912 * I'm NOT treating inner &'s as jobs */
3913 check_and_run_traps(0);
3915 if (G.run_list_level == 1)
3918 G.last_exitcode = rcode = EXIT_SUCCESS;
3919 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3922 if (G.run_list_level == 1 && G_interactive_fd) {
3923 /* Waits for completion, then fg's main shell */
3924 rcode = checkjobs_and_fg_shell(pi);
3925 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3926 check_and_run_traps(0);
3929 { /* This one just waits for completion */
3930 rcode = checkjobs(pi);
3931 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3932 check_and_run_traps(0);
3934 G.last_exitcode = rcode;
3938 /* Analyze how result affects subsequent commands */
3940 if (rword == RES_IF || rword == RES_ELIF)
3943 #if ENABLE_HUSH_LOOPS
3944 /* Beware of "while false; true; do ..."! */
3945 if (pi->next && pi->next->res_word == RES_DO) {
3946 if (rword == RES_WHILE) {
3948 /* "while false; do...done" - exitcode 0 */
3949 G.last_exitcode = rcode = EXIT_SUCCESS;
3950 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3951 goto check_jobs_and_break;
3954 if (rword == RES_UNTIL) {
3956 debug_printf_exec(": until expr is true: breaking\n");
3957 check_jobs_and_break:
3965 check_jobs_and_continue:
3970 //// if (G.ctrl_z_flag) {
3971 //// /* ctrl-Z forked somewhere in the past, we are the child,
3972 //// * and now we completed running the list. Exit. */
3978 //// if (!G.run_list_level && G_interactive_fd) {
3979 //// signal(SIGTSTP, SIG_IGN);
3980 //// signal(SIGINT, SIG_IGN);
3983 #if ENABLE_HUSH_LOOPS
3988 #if ENABLE_HUSH_CASE
3992 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3996 /* Select which version we will use */
3997 static int run_and_free_list(struct pipe *pi)
4000 debug_printf_exec("run_and_free_list entered\n");
4002 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4003 rcode = run_list(pi);
4005 /* free_pipe_list has the side effect of clearing memory.
4006 * In the long run that function can be merged with run_list,
4007 * but doing that now would hobble the debugging effort. */
4009 debug_printf_exec("run_and_free_list return %d\n", rcode);
4014 static struct pipe *new_pipe(void)
4017 pi = xzalloc(sizeof(struct pipe));
4018 /*pi->followup = 0; - deliberately invalid value */
4019 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4023 /* Command (member of a pipe) is complete. The only possible error here
4024 * is out of memory, in which case xmalloc exits. */
4025 static int done_command(struct parse_context *ctx)
4027 /* The command is really already in the pipe structure, so
4028 * advance the pipe counter and make a new, null command. */
4029 struct pipe *pi = ctx->pipe;
4030 struct command *command = ctx->command;
4033 if (command->group == NULL
4034 && command->argv == NULL
4035 && command->redirects == NULL
4037 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4038 memset(command, 0, sizeof(*command)); /* paranoia */
4039 return pi->num_cmds;
4042 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4043 //debug_print_tree(ctx->list_head, 20);
4045 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4048 /* Only real trickiness here is that the uncommitted
4049 * command structure is not counted in pi->num_cmds. */
4050 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4051 command = &pi->cmds[pi->num_cmds];
4052 memset(command, 0, sizeof(*command));
4054 ctx->command = command;
4055 /* but ctx->pipe and ctx->list_head remain unchanged */
4057 return pi->num_cmds; /* used only for 0/nonzero check */
4060 static void done_pipe(struct parse_context *ctx, pipe_style type)
4064 debug_printf_parse("done_pipe entered, followup %d\n", type);
4065 /* Close previous command */
4066 not_null = done_command(ctx);
4067 ctx->pipe->followup = type;
4069 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4070 ctx->ctx_inverted = 0;
4071 ctx->pipe->res_word = ctx->ctx_res_w;
4074 /* Without this check, even just <enter> on command line generates
4075 * tree of three NOPs (!). Which is harmless but annoying.
4076 * IOW: it is safe to do it unconditionally.
4077 * RES_NONE case is for "for a in; do ..." (empty IN set)
4078 * and other cases to work. */
4081 || ctx->ctx_res_w == RES_FI
4083 #if ENABLE_HUSH_LOOPS
4084 || ctx->ctx_res_w == RES_DONE
4085 || ctx->ctx_res_w == RES_FOR
4086 || ctx->ctx_res_w == RES_IN
4088 #if ENABLE_HUSH_CASE
4089 || ctx->ctx_res_w == RES_ESAC
4093 debug_printf_parse("done_pipe: adding new pipe: "
4094 "not_null:%d ctx->ctx_res_w:%d\n",
4095 not_null, ctx->ctx_res_w);
4097 ctx->pipe->next = new_p;
4099 /* RES_THEN, RES_DO etc are "sticky" -
4100 * they remain set for commands inside if/while.
4101 * This is used to control execution.
4102 * RES_FOR and RES_IN are NOT sticky (needed to support
4103 * cases where variable or value happens to match a keyword):
4105 #if ENABLE_HUSH_LOOPS
4106 if (ctx->ctx_res_w == RES_FOR
4107 || ctx->ctx_res_w == RES_IN)
4108 ctx->ctx_res_w = RES_NONE;
4110 #if ENABLE_HUSH_CASE
4111 if (ctx->ctx_res_w == RES_MATCH)
4112 ctx->ctx_res_w = RES_CASEI;
4114 ctx->command = NULL; /* trick done_command below */
4115 /* Create the memory for command, roughly:
4116 * ctx->pipe->cmds = new struct command;
4117 * ctx->command = &ctx->pipe->cmds[0];
4120 //debug_print_tree(ctx->list_head, 10);
4122 debug_printf_parse("done_pipe return\n");
4125 static void initialize_context(struct parse_context *ctx)
4127 memset(ctx, 0, sizeof(*ctx));
4128 ctx->pipe = ctx->list_head = new_pipe();
4129 /* Create the memory for command, roughly:
4130 * ctx->pipe->cmds = new struct command;
4131 * ctx->command = &ctx->pipe->cmds[0];
4136 /* If a reserved word is found and processed, parse context is modified
4137 * and 1 is returned.
4140 struct reserved_combo {
4143 unsigned char assignment_flag;
4147 FLAG_END = (1 << RES_NONE ),
4149 FLAG_IF = (1 << RES_IF ),
4150 FLAG_THEN = (1 << RES_THEN ),
4151 FLAG_ELIF = (1 << RES_ELIF ),
4152 FLAG_ELSE = (1 << RES_ELSE ),
4153 FLAG_FI = (1 << RES_FI ),
4155 #if ENABLE_HUSH_LOOPS
4156 FLAG_FOR = (1 << RES_FOR ),
4157 FLAG_WHILE = (1 << RES_WHILE),
4158 FLAG_UNTIL = (1 << RES_UNTIL),
4159 FLAG_DO = (1 << RES_DO ),
4160 FLAG_DONE = (1 << RES_DONE ),
4161 FLAG_IN = (1 << RES_IN ),
4163 #if ENABLE_HUSH_CASE
4164 FLAG_MATCH = (1 << RES_MATCH),
4165 FLAG_ESAC = (1 << RES_ESAC ),
4167 FLAG_START = (1 << RES_XXXX ),
4170 static const struct reserved_combo* match_reserved_word(o_string *word)
4172 /* Mostly a list of accepted follow-up reserved words.
4173 * FLAG_END means we are done with the sequence, and are ready
4174 * to turn the compound list into a command.
4175 * FLAG_START means the word must start a new compound list.
4177 static const struct reserved_combo reserved_list[] = {
4179 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4180 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4181 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4182 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4183 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4184 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4186 #if ENABLE_HUSH_LOOPS
4187 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4188 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4189 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4190 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4191 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4192 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4194 #if ENABLE_HUSH_CASE
4195 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4196 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4199 const struct reserved_combo *r;
4201 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4202 if (strcmp(word->data, r->literal) == 0)
4207 static int reserved_word(o_string *word, struct parse_context *ctx)
4209 #if ENABLE_HUSH_CASE
4210 static const struct reserved_combo reserved_match = {
4211 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4214 const struct reserved_combo *r;
4216 r = match_reserved_word(word);
4220 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4221 #if ENABLE_HUSH_CASE
4222 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4223 /* "case word IN ..." - IN part starts first match part */
4224 r = &reserved_match;
4227 if (r->flag == 0) { /* '!' */
4228 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4229 syntax_error("! ! command");
4230 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
4232 ctx->ctx_inverted = 1;
4235 if (r->flag & FLAG_START) {
4236 struct parse_context *old;
4237 old = xmalloc(sizeof(*old));
4238 debug_printf_parse("push stack %p\n", old);
4239 *old = *ctx; /* physical copy */
4240 initialize_context(ctx);
4242 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4243 syntax_error_at(word->data);
4244 ctx->ctx_res_w = RES_SNTX;
4247 ctx->ctx_res_w = r->res;
4248 ctx->old_flag = r->flag;
4249 if (ctx->old_flag & FLAG_END) {
4250 struct parse_context *old;
4251 done_pipe(ctx, PIPE_SEQ);
4252 debug_printf_parse("pop stack %p\n", ctx->stack);
4254 old->command->group = ctx->list_head;
4255 old->command->grp_type = GRP_NORMAL;
4257 o_addstr(&old->as_string, ctx->as_string.data);
4258 o_free_unsafe(&ctx->as_string);
4259 old->command->group_as_string = xstrdup(old->as_string.data);
4260 debug_printf_parse("pop, remembering as:'%s'\n",
4261 old->command->group_as_string);
4263 *ctx = *old; /* physical copy */
4266 word->o_assignment = r->assignment_flag;
4271 /* Word is complete, look at it and update parsing context.
4272 * Normal return is 0. Syntax errors return 1.
4273 * Note: on return, word is reset, but not o_free'd!
4275 static int done_word(o_string *word, struct parse_context *ctx)
4277 struct command *command = ctx->command;
4279 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4280 if (word->length == 0 && word->o_quoted == 0) {
4281 debug_printf_parse("done_word return 0: true null, ignored\n");
4285 if (ctx->pending_redirect) {
4286 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4287 * only if run as "bash", not "sh" */
4288 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4290 * ...the word that follows the redirection operator
4291 * shall be subjected to tilde expansion, parameter expansion,
4292 * command substitution, arithmetic expansion, and quote
4293 * removal. Pathname expansion shall not be performed
4294 * on the word by a non-interactive shell; an interactive
4295 * shell may perform it, but shall do so only when
4296 * the expansion would result in one word."
4298 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4299 /* Cater for >\file case:
4300 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4301 * Same with heredocs:
4302 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4304 unbackslash(ctx->pending_redirect->rd_filename);
4305 /* Is it <<"HEREDOC"? */
4306 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4309 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4311 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4312 ctx->pending_redirect = NULL;
4314 /* If this word wasn't an assignment, next ones definitely
4315 * can't be assignments. Even if they look like ones. */
4316 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4317 && word->o_assignment != WORD_IS_KEYWORD
4319 word->o_assignment = NOT_ASSIGNMENT;
4321 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4322 command->assignment_cnt++;
4323 word->o_assignment = MAYBE_ASSIGNMENT;
4326 if (command->group) {
4327 /* "{ echo foo; } echo bar" - bad */
4328 /* NB: bash allows e.g.:
4329 * if true; then { echo foo; } fi
4330 * while if false; then false; fi do break; done
4332 * while if false; then false; fi; do; break; done
4334 syntax_error_at(word->data);
4335 debug_printf_parse("done_word return 1: syntax error, "
4336 "groups and arglists don't mix\n");
4340 # if ENABLE_HUSH_CASE
4341 if (ctx->ctx_dsemicolon
4342 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4344 /* already done when ctx_dsemicolon was set to 1: */
4345 /* ctx->ctx_res_w = RES_MATCH; */
4346 ctx->ctx_dsemicolon = 0;
4349 if (!command->argv /* if it's the first word... */
4350 # if ENABLE_HUSH_LOOPS
4351 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4352 && ctx->ctx_res_w != RES_IN
4355 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
4356 if (reserved_word(word, ctx)) {
4357 o_reset_to_empty_unquoted(word);
4358 debug_printf_parse("done_word return %d\n",
4359 (ctx->ctx_res_w == RES_SNTX));
4360 return (ctx->ctx_res_w == RES_SNTX);
4364 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4365 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4366 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4367 /* (otherwise it's known to be not empty and is already safe) */
4369 /* exclude "$@" - it can expand to no word despite "" */
4370 char *p = word->data;
4371 while (p[0] == SPECIAL_VAR_SYMBOL
4372 && (p[1] & 0x7f) == '@'
4373 && p[2] == SPECIAL_VAR_SYMBOL
4377 if (p == word->data || p[0] != '\0') {
4378 /* saw no "$@", or not only "$@" but some
4379 * real text is there too */
4380 /* insert "empty variable" reference, this makes
4381 * e.g. "", $empty"" etc to not disappear */
4382 o_addchr(word, SPECIAL_VAR_SYMBOL);
4383 o_addchr(word, SPECIAL_VAR_SYMBOL);
4386 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4387 //SEGV, but good idea.
4388 // command->argv = add_string_to_strings(command->argv, word->data);
4389 // word->data = NULL;
4390 // word->length = 0;
4391 debug_print_strings("word appended to argv", command->argv);
4394 #if ENABLE_HUSH_LOOPS
4395 if (ctx->ctx_res_w == RES_FOR) {
4397 || !is_well_formed_var_name(command->argv[0], '\0')
4399 /* bash says just "not a valid identifier" */
4400 syntax_error("not a valid identifier in for");
4403 /* Force FOR to have just one word (variable name) */
4404 /* NB: basically, this makes hush see "for v in ..."
4405 * syntax as if it is "for v; in ...". FOR and IN become
4406 * two pipe structs in parse tree. */
4407 done_pipe(ctx, PIPE_SEQ);
4410 #if ENABLE_HUSH_CASE
4411 /* Force CASE to have just one word */
4412 if (ctx->ctx_res_w == RES_CASE) {
4413 done_pipe(ctx, PIPE_SEQ);
4417 o_reset_to_empty_unquoted(word);
4419 debug_printf_parse("done_word return 0\n");
4424 /* Peek ahead in the input to find out if we have a "&n" construct,
4425 * as in "2>&1", that represents duplicating a file descriptor.
4427 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4428 * REDIRFD_SYNTAX_ERR if syntax error,
4429 * REDIRFD_TO_FILE if no & was seen,
4430 * or the number found.
4433 #define parse_redir_right_fd(as_string, input) \
4434 parse_redir_right_fd(input)
4436 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4442 return REDIRFD_TO_FILE;
4444 ch = i_getch(input); /* get the & */
4445 nommu_addchr(as_string, ch);
4448 ch = i_getch(input);
4449 nommu_addchr(as_string, ch);
4450 return REDIRFD_CLOSE;
4454 while (ch != EOF && isdigit(ch)) {
4455 d = d*10 + (ch-'0');
4457 ch = i_getch(input);
4458 nommu_addchr(as_string, ch);
4463 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4465 bb_error_msg("ambiguous redirect");
4466 return REDIRFD_SYNTAX_ERR;
4469 /* Return code is 0 normal, 1 if a syntax error is detected
4471 static int parse_redirect(struct parse_context *ctx,
4474 struct in_str *input)
4476 struct command *command = ctx->command;
4477 struct redir_struct *redir;
4478 struct redir_struct **redirp;
4481 dup_num = REDIRFD_TO_FILE;
4482 if (style != REDIRECT_HEREDOC) {
4483 /* Check for a '>&1' type redirect */
4484 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4485 if (dup_num == REDIRFD_SYNTAX_ERR)
4488 int ch = i_peek(input);
4489 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4490 if (dup_num) { /* <<-... */
4491 ch = i_getch(input);
4492 nommu_addchr(&ctx->as_string, ch);
4497 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4498 int ch = i_peek(input);
4500 /* >|FILE redirect ("clobbering" >).
4501 * Since we do not support "set -o noclobber" yet,
4502 * >| and > are the same for now. Just eat |.
4504 ch = i_getch(input);
4505 nommu_addchr(&ctx->as_string, ch);
4509 /* Create a new redir_struct and append it to the linked list */
4510 redirp = &command->redirects;
4511 while ((redir = *redirp) != NULL) {
4512 redirp = &(redir->next);
4514 *redirp = redir = xzalloc(sizeof(*redir));
4515 /* redir->next = NULL; */
4516 /* redir->rd_filename = NULL; */
4517 redir->rd_type = style;
4518 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4520 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4521 redir_table[style].descrip);
4523 redir->rd_dup = dup_num;
4524 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4525 /* Erik had a check here that the file descriptor in question
4526 * is legit; I postpone that to "run time"
4527 * A "-" representation of "close me" shows up as a -3 here */
4528 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4529 redir->rd_fd, redir->rd_dup);
4531 /* Set ctx->pending_redirect, so we know what to do at the
4532 * end of the next parsed word. */
4533 ctx->pending_redirect = redir;
4538 /* If a redirect is immediately preceded by a number, that number is
4539 * supposed to tell which file descriptor to redirect. This routine
4540 * looks for such preceding numbers. In an ideal world this routine
4541 * needs to handle all the following classes of redirects...
4542 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4543 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4544 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4545 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4547 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4549 * ... If n is quoted, the number shall not be recognized as part of
4550 * the redirection expression. For example:
4552 * writes the character 2 into file a"
4553 * We are getting it right by setting ->o_quoted on any \<char>
4555 * A -1 return means no valid number was found,
4556 * the caller should use the appropriate default for this redirection.
4558 static int redirect_opt_num(o_string *o)
4562 if (o->data == NULL)
4564 num = bb_strtou(o->data, NULL, 10);
4565 if (errno || num < 0)
4567 o_reset_to_empty_unquoted(o);
4572 #define fetch_till_str(as_string, input, word, skip_tabs) \
4573 fetch_till_str(input, word, skip_tabs)
4575 static char *fetch_till_str(o_string *as_string,
4576 struct in_str *input,
4580 o_string heredoc = NULL_O_STRING;
4586 ch = i_getch(input);
4587 nommu_addchr(as_string, ch);
4589 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4590 heredoc.data[past_EOL] = '\0';
4591 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4592 return heredoc.data;
4595 o_addchr(&heredoc, ch);
4596 past_EOL = heredoc.length;
4599 ch = i_getch(input);
4600 nommu_addchr(as_string, ch);
4601 } while (skip_tabs && ch == '\t');
4602 } while (ch == '\n');
4605 o_free_unsafe(&heredoc);
4608 o_addchr(&heredoc, ch);
4609 nommu_addchr(as_string, ch);
4613 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4614 * and load them all. There should be exactly heredoc_cnt of them.
4616 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4618 struct pipe *pi = ctx->list_head;
4620 while (pi && heredoc_cnt) {
4622 struct command *cmd = pi->cmds;
4624 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4626 cmd->argv ? cmd->argv[0] : "NONE");
4627 for (i = 0; i < pi->num_cmds; i++) {
4628 struct redir_struct *redir = cmd->redirects;
4630 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4631 i, cmd->argv ? cmd->argv[0] : "NONE");
4633 if (redir->rd_type == REDIRECT_HEREDOC) {
4636 redir->rd_type = REDIRECT_HEREDOC2;
4637 /* redir->dup is (ab)used to indicate <<- */
4638 p = fetch_till_str(&ctx->as_string, input,
4639 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4641 syntax_error("unexpected EOF in here document");
4644 free(redir->rd_filename);
4645 redir->rd_filename = p;
4648 redir = redir->next;
4655 /* Should be 0. If it isn't, it's a parse error */
4657 bb_error_msg_and_die("heredoc BUG 2");
4663 #if ENABLE_HUSH_TICK
4664 static FILE *generate_stream_from_string(const char *s)
4667 int pid, channel[2];
4673 pid = BB_MMU ? fork() : vfork();
4675 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4677 if (pid == 0) { /* child */
4678 disable_restore_tty_pgrp_on_exit();
4679 /* Process substitution is not considered to be usual
4680 * 'command execution'.
4681 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4688 close(channel[0]); /* NB: close _first_, then move fd! */
4689 xmove_fd(channel[1], 1);
4690 /* Prevent it from trying to handle ctrl-z etc */
4691 USE_HUSH_JOB(G.run_list_level = 1;)
4693 reset_traps_to_defaults();
4694 parse_and_run_string(s);
4695 _exit(G.last_exitcode);
4697 /* We re-execute after vfork on NOMMU. This makes this script safe:
4698 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4699 * huge=`cat BIG` # was blocking here forever
4702 re_execute_shell(&to_free,
4710 enable_restore_tty_pgrp_on_exit();
4715 pf = fdopen(channel[0], "r");
4719 /* Return code is exit status of the process that is run. */
4720 static int process_command_subs(o_string *dest, const char *s)
4723 struct in_str pipe_str;
4726 pf = generate_stream_from_string(s);
4729 close_on_exec_on(fileno(pf));
4731 /* Now send results of command back into original context */
4732 setup_file_in_str(&pipe_str, pf);
4734 while ((ch = i_getch(&pipe_str)) != EOF) {
4740 o_addchr(dest, '\n');
4743 o_addQchr(dest, ch);
4746 debug_printf("done reading from pipe, pclose()ing\n");
4747 /* Note: we got EOF, and we just close the read end of the pipe.
4748 * We do not wait for the `cmd` child to terminate. bash and ash do.
4750 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4751 * `false`; echo $? - bash outputs "1"
4754 debug_printf("closed FILE from child. return 0\n");
4759 static int parse_group(o_string *dest, struct parse_context *ctx,
4760 struct in_str *input, int ch)
4762 /* dest contains characters seen prior to ( or {.
4763 * Typically it's empty, but for function defs,
4764 * it contains function name (without '()'). */
4765 struct pipe *pipe_list;
4767 struct command *command = ctx->command;
4769 debug_printf_parse("parse_group entered\n");
4770 #if ENABLE_HUSH_FUNCTIONS
4771 if (ch == '(' && !dest->o_quoted) {
4773 done_word(dest, ctx);
4775 goto skip; /* (... */
4776 if (command->argv[1]) { /* word word ... (... */
4777 syntax_error_unexpected_ch('(');
4780 /* it is "word(..." or "word (..." */
4782 ch = i_getch(input);
4783 while (ch == ' ' || ch == '\t');
4785 syntax_error_unexpected_ch(ch);
4788 nommu_addchr(&ctx->as_string, ch);
4790 ch = i_getch(input);
4791 while (ch == ' ' || ch == '\t' || ch == '\n');
4793 syntax_error_unexpected_ch(ch);
4796 nommu_addchr(&ctx->as_string, ch);
4797 command->grp_type = GRP_FUNCTION;
4801 if (command->argv /* word [word]{... */
4802 || dest->length /* word{... */
4803 || dest->o_quoted /* ""{... */
4806 debug_printf_parse("parse_group return 1: "
4807 "syntax error, groups and arglists don't mix\n");
4811 #if ENABLE_HUSH_FUNCTIONS
4817 command->grp_type = GRP_SUBSHELL;
4822 char *as_string = NULL;
4824 pipe_list = parse_stream(&as_string, input, endch);
4827 o_addstr(&ctx->as_string, as_string);
4829 /* empty ()/{} or parse error? */
4830 if (!pipe_list || pipe_list == ERR_PTR) {
4835 debug_printf_parse("parse_group return 1: "
4836 "parse_stream returned %p\n", pipe_list);
4839 command->group = pipe_list;
4841 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4842 command->group_as_string = as_string;
4843 debug_printf_parse("end of group, remembering as:'%s'\n",
4844 command->group_as_string);
4847 debug_printf_parse("parse_group return 0\n");
4849 /* command remains "open", available for possible redirects */
4852 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4853 /* Subroutines for copying $(...) and `...` things */
4854 static void add_till_backquote(o_string *dest, struct in_str *input);
4856 static void add_till_single_quote(o_string *dest, struct in_str *input)
4859 int ch = i_getch(input);
4861 syntax_error_unterm_ch('\'');
4862 /*xfunc_die(); - redundant */
4869 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4870 static void add_till_double_quote(o_string *dest, struct in_str *input)
4873 int ch = i_getch(input);
4875 syntax_error_unterm_ch('"');
4876 /*xfunc_die(); - redundant */
4880 if (ch == '\\') { /* \x. Copy both chars. */
4882 ch = i_getch(input);
4886 add_till_backquote(dest, input);
4890 //if (ch == '$') ...
4893 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4895 * "Within the backquoted style of command substitution, backslash
4896 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4897 * The search for the matching backquote shall be satisfied by the first
4898 * backquote found without a preceding backslash; during this search,
4899 * if a non-escaped backquote is encountered within a shell comment,
4900 * a here-document, an embedded command substitution of the $(command)
4901 * form, or a quoted string, undefined results occur. A single-quoted
4902 * or double-quoted string that begins, but does not end, within the
4903 * "`...`" sequence produces undefined results."
4905 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4907 static void add_till_backquote(o_string *dest, struct in_str *input)
4910 int ch = i_getch(input);
4912 syntax_error_unterm_ch('`');
4913 /*xfunc_die(); - redundant */
4918 /* \x. Copy both chars unless it is \` */
4919 int ch2 = i_getch(input);
4921 syntax_error_unterm_ch('`');
4922 /*xfunc_die(); - redundant */
4924 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4931 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4932 * quoting and nested ()s.
4933 * "With the $(command) style of command substitution, all characters
4934 * following the open parenthesis to the matching closing parenthesis
4935 * constitute the command. Any valid shell script can be used for command,
4936 * except a script consisting solely of redirections which produces
4937 * unspecified results."
4939 * echo $(echo '(TEST)' BEST) (TEST) BEST
4940 * echo $(echo 'TEST)' BEST) TEST) BEST
4941 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4943 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4947 int ch = i_getch(input);
4949 syntax_error_unterm_ch(')');
4950 /*xfunc_die(); - redundant */
4958 if (i_peek(input) == ')') {
4966 add_till_single_quote(dest, input);
4971 add_till_double_quote(dest, input);
4976 /* \x. Copy verbatim. Important for \(, \) */
4977 ch = i_getch(input);
4979 syntax_error_unterm_ch(')');
4980 /*xfunc_die(); - redundant */
4987 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4989 /* Return code: 0 for OK, 1 for syntax error */
4991 #define handle_dollar(as_string, dest, input) \
4992 handle_dollar(dest, input)
4994 static int handle_dollar(o_string *as_string,
4996 struct in_str *input)
4999 int ch = i_peek(input); /* first character after the $ */
5000 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5002 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5004 ch = i_getch(input);
5005 nommu_addchr(as_string, ch);
5007 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5009 debug_printf_parse(": '%c'\n", ch);
5010 o_addchr(dest, ch | quote_mask);
5013 if (!isalnum(ch) && ch != '_')
5015 ch = i_getch(input);
5016 nommu_addchr(as_string, ch);
5018 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5019 } else if (isdigit(ch)) {
5021 ch = i_getch(input);
5022 nommu_addchr(as_string, ch);
5023 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5024 debug_printf_parse(": '%c'\n", ch);
5025 o_addchr(dest, ch | quote_mask);
5026 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5027 } else switch (ch) {
5029 case '!': /* last bg pid */
5030 case '?': /* last exit code */
5031 case '#': /* number of args */
5032 case '*': /* args */
5033 case '@': /* args */
5034 goto make_one_char_var;
5036 bool first_char, all_digits;
5038 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5039 ch = i_getch(input);
5040 nommu_addchr(as_string, ch);
5041 /* XXX maybe someone will try to escape the '}' */
5046 ch = i_getch(input);
5047 nommu_addchr(as_string, ch);
5053 /* ${#var}: length of var contents */
5055 else if (isdigit(ch)) {
5062 && ( (all_digits && !isdigit(ch))
5063 || (!all_digits && !isalnum(ch) && ch != '_')
5066 /* handle parameter expansions
5067 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5072 case ':': /* null modifier */
5073 if (expansion == 0) {
5074 debug_printf_parse(": null modifier\n");
5079 case '#': /* remove prefix */
5080 case '%': /* remove suffix */
5081 if (expansion == 0) {
5082 debug_printf_parse(": remove suffix/prefix\n");
5087 case '-': /* default value */
5088 case '=': /* assign default */
5089 case '+': /* alternative */
5090 case '?': /* error indicate */
5091 debug_printf_parse(": parameter expansion\n");
5096 syntax_error_unterm_str("${name}");
5097 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5102 debug_printf_parse(": '%c'\n", ch);
5103 o_addchr(dest, ch | quote_mask);
5107 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5110 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5115 ch = i_getch(input);
5116 nommu_addchr(as_string, ch);
5117 # if ENABLE_SH_MATH_SUPPORT
5118 if (i_peek(input) == '(') {
5119 ch = i_getch(input);
5120 nommu_addchr(as_string, ch);
5121 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5122 o_addchr(dest, /*quote_mask |*/ '+');
5126 add_till_closing_paren(dest, input, true);
5129 o_addstr(as_string, dest->data + pos);
5130 o_addchr(as_string, ')');
5131 o_addchr(as_string, ')');
5134 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5138 # if ENABLE_HUSH_TICK
5139 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5140 o_addchr(dest, quote_mask | '`');
5144 add_till_closing_paren(dest, input, false);
5147 o_addstr(as_string, dest->data + pos);
5148 o_addchr(as_string, '`');
5151 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5157 ch = i_getch(input);
5158 nommu_addchr(as_string, ch);
5160 if (isalnum(ch)) { /* it's $_name or $_123 */
5166 /* $_ Shell or shell script name; or last cmd name */
5167 /* $- Option flags set by set builtin or shell options (-i etc) */
5169 o_addQchr(dest, '$');
5171 debug_printf_parse("handle_dollar return 0\n");
5176 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5177 parse_stream_dquoted(dest, input, dquote_end)
5179 static int parse_stream_dquoted(o_string *as_string,
5181 struct in_str *input,
5188 ch = i_getch(input);
5190 nommu_addchr(as_string, ch);
5191 if (ch == dquote_end) { /* may be only '"' or EOF */
5192 if (dest->o_assignment == NOT_ASSIGNMENT)
5193 dest->o_escape ^= 1;
5194 debug_printf_parse("parse_stream_dquoted return 0\n");
5197 /* note: can't move it above ch == dquote_end check! */
5199 syntax_error_unterm_ch('"');
5200 /*xfunc_die(); - redundant */
5204 next = i_peek(input);
5206 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5207 ch, ch, dest->o_escape);
5210 syntax_error("\\<eof>");
5214 * "The backslash retains its special meaning [in "..."]
5215 * only when followed by one of the following characters:
5216 * $, `, ", \, or <newline>. A double quote may be quoted
5217 * within double quotes by preceding it with a backslash.
5219 if (strchr("$`\"\\", next) != NULL) {
5220 o_addqchr(dest, i_getch(input));
5222 o_addqchr(dest, '\\');
5227 if (handle_dollar(as_string, dest, input) != 0) {
5228 debug_printf_parse("parse_stream_dquoted return 1: "
5229 "handle_dollar returned non-0\n");
5234 #if ENABLE_HUSH_TICK
5236 //int pos = dest->length;
5237 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5238 o_addchr(dest, 0x80 | '`');
5239 add_till_backquote(dest, input);
5240 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5241 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5245 o_addQchr(dest, ch);
5247 && (dest->o_assignment == MAYBE_ASSIGNMENT
5248 || dest->o_assignment == WORD_IS_KEYWORD)
5249 && is_well_formed_var_name(dest->data, '=')
5251 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5257 * Scan input until EOF or end_trigger char.
5258 * Return a list of pipes to execute, or NULL on EOF
5259 * or if end_trigger character is met.
5260 * On syntax error, exit is shell is not interactive,
5261 * reset parsing machinery and start parsing anew,
5262 * or return ERR_PTR.
5264 static struct pipe *parse_stream(char **pstring,
5265 struct in_str *input,
5268 struct parse_context ctx;
5269 o_string dest = NULL_O_STRING;
5273 /* Double-quote state is handled in the state variable is_in_dquote.
5274 * A single-quote triggers a bypass of the main loop until its mate is
5275 * found. When recursing, quote state is passed in via dest->o_escape.
5277 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5278 end_trigger ? : 'X');
5281 G.ifs = get_local_var_value("IFS");
5286 #if ENABLE_HUSH_INTERACTIVE
5287 input->promptmode = 0; /* PS1 */
5289 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5290 initialize_context(&ctx);
5295 const char *is_special;
5299 redir_type redir_style;
5302 /* dest.o_quoted = 1; - already is (see below) */
5303 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5306 /* We reached closing '"' */
5309 ch = i_getch(input);
5310 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5311 ch, ch, dest.o_escape);
5316 syntax_error_unterm_str("here document");
5319 if (done_word(&dest, &ctx)) {
5323 done_pipe(&ctx, PIPE_SEQ);
5325 /* If we got nothing... */
5326 /* (this makes bare "&" cmd a no-op.
5327 * bash says: "syntax error near unexpected token '&'") */
5328 if (pi->num_cmds == 0
5329 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5335 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5337 *pstring = ctx.as_string.data;
5339 o_free_unsafe(&ctx.as_string);
5342 debug_printf_parse("parse_stream return %p\n", pi);
5345 nommu_addchr(&ctx.as_string, ch);
5346 is_ifs = strchr(G.ifs, ch);
5347 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5348 "\\$\"" USE_HUSH_TICK("`") /* always special */
5351 if (!is_special && !is_ifs) { /* ordinary char */
5352 o_addQchr(&dest, ch);
5353 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5354 || dest.o_assignment == WORD_IS_KEYWORD)
5356 && is_well_formed_var_name(dest.data, '=')
5358 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5364 if (done_word(&dest, &ctx)) {
5368 #if ENABLE_HUSH_CASE
5369 /* "case ... in <newline> word) ..." -
5370 * newlines are ignored (but ';' wouldn't be) */
5371 if (ctx.command->argv == NULL
5372 && ctx.ctx_res_w == RES_MATCH
5377 /* Treat newline as a command separator. */
5378 done_pipe(&ctx, PIPE_SEQ);
5379 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5381 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5386 dest.o_assignment = MAYBE_ASSIGNMENT;
5388 /* note: if (is_ifs) continue;
5389 * will still trigger for us */
5392 if (end_trigger && end_trigger == ch
5393 && (heredoc_cnt == 0 || end_trigger != ';')
5395 //TODO: disallow "{ cmd }" without semicolon
5397 /* This is technically valid:
5398 * { cat <<HERE; }; echo Ok
5403 * but we don't support this.
5404 * We require heredoc to be in enclosing {}/(),
5407 syntax_error_unterm_str("here document");
5410 if (done_word(&dest, &ctx)) {
5413 done_pipe(&ctx, PIPE_SEQ);
5414 dest.o_assignment = MAYBE_ASSIGNMENT;
5415 /* Do we sit outside of any if's, loops or case's? */
5417 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5421 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5423 *pstring = ctx.as_string.data;
5425 o_free_unsafe(&ctx.as_string);
5428 debug_printf_parse("parse_stream return %p: "
5429 "end_trigger char found\n",
5431 return ctx.list_head;
5439 next = i_peek(input);
5442 /* Catch <, > before deciding whether this word is
5443 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5446 redir_fd = redirect_opt_num(&dest);
5447 if (done_word(&dest, &ctx)) {
5450 redir_style = REDIRECT_OVERWRITE;
5452 redir_style = REDIRECT_APPEND;
5453 ch = i_getch(input);
5454 nommu_addchr(&ctx.as_string, ch);
5457 else if (next == '(') {
5458 syntax_error(">(process) not supported");
5462 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5464 continue; /* back to top of while (1) */
5466 redir_fd = redirect_opt_num(&dest);
5467 if (done_word(&dest, &ctx)) {
5470 redir_style = REDIRECT_INPUT;
5472 redir_style = REDIRECT_HEREDOC;
5474 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5475 ch = i_getch(input);
5476 nommu_addchr(&ctx.as_string, ch);
5477 } else if (next == '>') {
5478 redir_style = REDIRECT_IO;
5479 ch = i_getch(input);
5480 nommu_addchr(&ctx.as_string, ch);
5483 else if (next == '(') {
5484 syntax_error("<(process) not supported");
5488 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5490 continue; /* back to top of while (1) */
5493 if (dest.o_assignment == MAYBE_ASSIGNMENT
5494 /* check that we are not in word in "a=1 2>word b=1": */
5495 && !ctx.pending_redirect
5497 /* ch is a special char and thus this word
5498 * cannot be an assignment */
5499 dest.o_assignment = NOT_ASSIGNMENT;
5504 if (dest.length == 0) {
5507 if (ch == EOF || ch == '\n')
5510 /* note: we do not add it to &ctx.as_string */
5512 nommu_addchr(&ctx.as_string, '\n');
5514 o_addQchr(&dest, ch);
5519 syntax_error("\\<eof>");
5522 o_addchr(&dest, '\\');
5523 ch = i_getch(input);
5524 nommu_addchr(&ctx.as_string, ch);
5525 o_addchr(&dest, ch);
5526 /* Example: echo Hello \2>file
5527 * we need to know that word 2 is quoted */
5531 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5532 debug_printf_parse("parse_stream parse error: "
5533 "handle_dollar returned non-0\n");
5540 ch = i_getch(input);
5542 syntax_error_unterm_ch('\'');
5543 /*xfunc_die(); - redundant */
5545 nommu_addchr(&ctx.as_string, ch);
5548 if (dest.o_assignment == NOT_ASSIGNMENT)
5549 o_addqchr(&dest, ch);
5551 o_addchr(&dest, ch);
5556 is_in_dquote ^= 1; /* invert */
5557 if (dest.o_assignment == NOT_ASSIGNMENT)
5560 #if ENABLE_HUSH_TICK
5565 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5566 o_addchr(&dest, '`');
5570 add_till_backquote(&dest, input);
5572 o_addstr(&ctx.as_string, dest.data + pos);
5573 o_addchr(&ctx.as_string, '`');
5575 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5576 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5581 #if ENABLE_HUSH_CASE
5584 if (done_word(&dest, &ctx)) {
5587 done_pipe(&ctx, PIPE_SEQ);
5588 #if ENABLE_HUSH_CASE
5589 /* Eat multiple semicolons, detect
5590 * whether it means something special */
5595 ch = i_getch(input);
5596 nommu_addchr(&ctx.as_string, ch);
5597 if (ctx.ctx_res_w == RES_CASEI) {
5598 ctx.ctx_dsemicolon = 1;
5599 ctx.ctx_res_w = RES_MATCH;
5605 /* We just finished a cmd. New one may start
5606 * with an assignment */
5607 dest.o_assignment = MAYBE_ASSIGNMENT;
5610 if (done_word(&dest, &ctx)) {
5614 ch = i_getch(input);
5615 nommu_addchr(&ctx.as_string, ch);
5616 done_pipe(&ctx, PIPE_AND);
5618 done_pipe(&ctx, PIPE_BG);
5622 if (done_word(&dest, &ctx)) {
5625 #if ENABLE_HUSH_CASE
5626 if (ctx.ctx_res_w == RES_MATCH)
5627 break; /* we are in case's "word | word)" */
5629 if (next == '|') { /* || */
5630 ch = i_getch(input);
5631 nommu_addchr(&ctx.as_string, ch);
5632 done_pipe(&ctx, PIPE_OR);
5634 /* we could pick up a file descriptor choice here
5635 * with redirect_opt_num(), but bash doesn't do it.
5636 * "echo foo 2| cat" yields "foo 2". */
5641 #if ENABLE_HUSH_CASE
5642 /* "case... in [(]word)..." - skip '(' */
5643 if (ctx.ctx_res_w == RES_MATCH
5644 && ctx.command->argv == NULL /* not (word|(... */
5645 && dest.length == 0 /* not word(... */
5646 && dest.o_quoted == 0 /* not ""(... */
5652 if (parse_group(&dest, &ctx, input, ch) != 0) {
5657 #if ENABLE_HUSH_CASE
5658 if (ctx.ctx_res_w == RES_MATCH)
5662 /* proper use of this character is caught by end_trigger:
5663 * if we see {, we call parse_group(..., end_trigger='}')
5664 * and it will match } earlier (not here). */
5665 syntax_error_unexpected_ch(ch);
5669 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5675 struct parse_context *pctx;
5676 IF_HAS_KEYWORDS(struct parse_context *p2;)
5678 /* Clean up allocated tree.
5679 * Samples for finding leaks on syntax error recovery path.
5680 * Run them from interactive shell, watch pmap `pidof hush`.
5681 * while if false; then false; fi do break; done
5683 * while if false; then false; fi; do break; fi
5684 * Samples to catch leaks at execution:
5685 * while if (true | {true;}); then echo ok; fi; do break; done
5686 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5690 /* Update pipe/command counts,
5691 * otherwise freeing may miss some */
5692 done_pipe(pctx, PIPE_SEQ);
5693 debug_printf_clean("freeing list %p from ctx %p\n",
5694 pctx->list_head, pctx);
5695 debug_print_tree(pctx->list_head, 0);
5696 free_pipe_list(pctx->list_head);
5697 debug_printf_clean("freed list %p\n", pctx->list_head);
5699 o_free_unsafe(&pctx->as_string);
5701 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5705 IF_HAS_KEYWORDS(pctx = p2;)
5706 } while (HAS_KEYWORDS && pctx);
5707 /* Free text, clear all dest fields */
5709 /* If we are not in top-level parse, we return,
5710 * our caller will propagate error.
5712 if (end_trigger != ';') {
5720 /* Discard cached input, force prompt */
5722 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5727 /* Executing from string: eval, sh -c '...'
5728 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5729 * end_trigger controls how often we stop parsing
5730 * NUL: parse all, execute, return
5731 * ';': parse till ';' or newline, execute, repeat till EOF
5733 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5736 struct pipe *pipe_list;
5738 pipe_list = parse_stream(NULL, inp, end_trigger);
5739 if (!pipe_list) /* EOF */
5741 debug_print_tree(pipe_list, 0);
5742 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5743 run_and_free_list(pipe_list);
5747 static void parse_and_run_string(const char *s)
5749 struct in_str input;
5750 setup_string_in_str(&input, s);
5751 parse_and_run_stream(&input, '\0');
5754 static void parse_and_run_file(FILE *f)
5756 struct in_str input;
5757 setup_file_in_str(&input, f);
5758 parse_and_run_stream(&input, ';');
5761 /* Called a few times only (or even once if "sh -c") */
5762 static void block_signals(int second_time)
5767 mask = (1 << SIGQUIT);
5768 if (G_interactive_fd) {
5772 //TODO | (1 << SIGHUP)
5774 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5779 G.non_DFL_mask = mask;
5782 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5786 sigaddset(&G.blocked_set, sig);
5790 sigdelset(&G.blocked_set, SIGCHLD);
5792 sigprocmask(SIG_SETMASK, &G.blocked_set,
5793 second_time ? NULL : &G.inherited_set);
5794 /* POSIX allows shell to re-enable SIGCHLD
5795 * even if it was SIG_IGN on entry */
5796 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5798 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5803 static void maybe_set_to_sigexit(int sig)
5805 void (*handler)(int);
5806 /* non_DFL_mask'ed signals are, well, masked,
5807 * no need to set handler for them.
5809 if (!((G.non_DFL_mask >> sig) & 1)) {
5810 handler = signal(sig, sigexit);
5811 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5812 signal(sig, handler);
5815 /* Set handlers to restore tty pgrp and exit */
5816 static void set_fatal_handlers(void)
5818 /* We _must_ restore tty pgrp on fatal signals */
5820 maybe_set_to_sigexit(SIGILL );
5821 maybe_set_to_sigexit(SIGFPE );
5822 maybe_set_to_sigexit(SIGBUS );
5823 maybe_set_to_sigexit(SIGSEGV);
5824 maybe_set_to_sigexit(SIGTRAP);
5825 } /* else: hush is perfect. what SEGV? */
5826 maybe_set_to_sigexit(SIGABRT);
5827 /* bash 3.2 seems to handle these just like 'fatal' ones */
5828 maybe_set_to_sigexit(SIGPIPE);
5829 maybe_set_to_sigexit(SIGALRM);
5830 //TODO: disable and move down when proper SIGHUP handling is added
5831 maybe_set_to_sigexit(SIGHUP );
5832 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5833 * if we aren't interactive... but in this case
5834 * we never want to restore pgrp on exit, and this fn is not called */
5835 /*maybe_set_to_sigexit(SIGTERM);*/
5836 /*maybe_set_to_sigexit(SIGINT );*/
5840 static int set_mode(const char cstate, const char mode)
5842 int state = (cstate == '-' ? 1 : 0);
5844 case 'n': G.fake_mode = state; break;
5845 case 'x': /*G.debug_mode = state;*/ break;
5846 default: return EXIT_FAILURE;
5848 return EXIT_SUCCESS;
5851 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5852 int hush_main(int argc, char **argv)
5854 static const struct variable const_shell_ver = {
5856 .varstr = (char*)hush_version_str,
5857 .max_len = 1, /* 0 can provoke free(name) */
5861 int signal_mask_is_inited = 0;
5864 struct variable *cur_var;
5867 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5868 G.last_exitcode = EXIT_SUCCESS;
5870 G.argv0_for_re_execing = argv[0];
5872 /* Deal with HUSH_VERSION */
5873 G.shell_ver = const_shell_ver; /* copying struct here */
5874 G.top_var = &G.shell_ver;
5875 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5876 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5877 /* Initialize our shell local variables with the values
5878 * currently living in the environment */
5879 cur_var = G.top_var;
5882 char *value = strchr(*e, '=');
5883 if (value) { /* paranoia */
5884 cur_var->next = xzalloc(sizeof(*cur_var));
5885 cur_var = cur_var->next;
5886 cur_var->varstr = *e;
5887 cur_var->max_len = strlen(*e);
5888 cur_var->flg_export = 1;
5892 debug_printf_env("putenv '%s'\n", hush_version_str);
5893 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5894 #if ENABLE_FEATURE_EDITING
5895 G.line_input_state = new_line_input_t(FOR_SHELL);
5897 G.global_argc = argc;
5898 G.global_argv = argv;
5899 /* Initialize some more globals to non-zero values */
5901 #if ENABLE_HUSH_INTERACTIVE
5902 if (ENABLE_FEATURE_EDITING)
5903 cmdedit_set_initial_prompt();
5907 if (setjmp(die_jmp)) {
5908 /* xfunc has failed! die die die */
5909 /* no EXIT traps, this is an escape hatch! */
5911 hush_exit(xfunc_error_retval);
5914 /* Shell is non-interactive at first. We need to call
5915 * block_signals(0) if we are going to execute "sh <script>",
5916 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5917 * If we later decide that we are interactive, we run block_signals(0)
5918 * (or re-run block_signals(1) if we ran block_signals(0) before)
5919 * in order to intercept (more) signals.
5923 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5925 opt = getopt(argc, argv, "c:xins"
5928 # if ENABLE_HUSH_FUNCTIONS
5938 G.root_pid = getpid();
5939 G.global_argv = argv + optind;
5940 if (!argv[optind]) {
5941 /* -c 'script' (no params): prevent empty $0 */
5942 *--G.global_argv = argv[0];
5944 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5945 G.global_argc = argc - optind;
5946 block_signals(0); /* 0: called 1st time */
5947 parse_and_run_string(optarg);
5950 /* Well, we cannot just declare interactiveness,
5951 * we have to have some stuff (ctty, etc) */
5952 /* G_interactive_fd++; */
5955 /* "-s" means "read from stdin", but this is how we always
5956 * operate, so simply do nothing here. */
5959 case '<': /* "big heredoc" support */
5960 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5963 G.root_pid = bb_strtou(optarg, &optarg, 16);
5965 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5967 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5968 # if ENABLE_HUSH_LOOPS
5970 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5975 set_local_var(xstrdup(optarg), 0, opt == 'R');
5977 # if ENABLE_HUSH_FUNCTIONS
5979 struct function *funcp = new_function(optarg);
5980 /* funcp->name is already set to optarg */
5981 /* funcp->body is set to NULL. It's a special case. */
5982 funcp->body_as_string = argv[optind];
5990 if (!set_mode('-', opt))
5994 fprintf(stderr, "Usage: sh [FILE]...\n"
5995 " or: sh -c command [args]...\n\n");
6001 } /* option parsing loop */
6004 G.root_pid = getpid();
6006 /* If we are login shell... */
6007 if (argv[0] && argv[0][0] == '-') {
6009 /* XXX what should argv be while sourcing /etc/profile? */
6010 debug_printf("sourcing /etc/profile\n");
6011 input = fopen_for_read("/etc/profile");
6012 if (input != NULL) {
6013 close_on_exec_on(fileno(input));
6014 block_signals(0); /* 0: called 1st time */
6015 signal_mask_is_inited = 1;
6016 parse_and_run_file(input);
6019 /* bash: after sourcing /etc/profile,
6020 * tries to source (in the given order):
6021 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6022 * stopping of first found. --noprofile turns this off.
6023 * bash also sources ~/.bash_logout on exit.
6024 * If called as sh, skips .bash_XXX files.
6031 * "bash <script>" (which is never interactive (unless -i?))
6032 * sources $BASH_ENV here (without scanning $PATH).
6033 * If called as sh, does the same but with $ENV.
6035 debug_printf("running script '%s'\n", argv[optind]);
6036 G.global_argv = argv + optind;
6037 G.global_argc = argc - optind;
6038 input = xfopen_for_read(argv[optind]);
6039 close_on_exec_on(fileno(input));
6040 if (!signal_mask_is_inited)
6041 block_signals(0); /* 0: called 1st time */
6042 parse_and_run_file(input);
6043 #if ENABLE_FEATURE_CLEAN_UP
6049 /* Up to here, shell was non-interactive. Now it may become one.
6050 * NB: don't forget to (re)run block_signals(0/1) as needed.
6053 /* A shell is interactive if the '-i' flag was given, or if all of
6054 * the following conditions are met:
6056 * no arguments remaining or the -s flag given
6057 * standard input is a terminal
6058 * standard output is a terminal
6059 * Refer to Posix.2, the description of the 'sh' utility.
6062 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6063 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6064 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6065 //TODO: "interactive" and "have job control" are two different things.
6066 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6067 //should stay on! Currently, we mix these into one.
6068 if (G.saved_tty_pgrp >= 0) {
6069 /* try to dup stdin to high fd#, >= 255 */
6070 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6071 if (G_interactive_fd < 0) {
6072 /* try to dup to any fd */
6073 G_interactive_fd = dup(STDIN_FILENO);
6074 if (G_interactive_fd < 0)
6076 G_interactive_fd = 0;
6078 // TODO: track & disallow any attempts of user
6079 // to (inadvertently) close/redirect it
6082 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6083 if (G_interactive_fd) {
6086 /* We are indeed interactive shell, and we will perform
6087 * job control. Setting up for that. */
6089 close_on_exec_on(G_interactive_fd);
6090 /* If we were run as 'hush &', sleep until we are
6091 * in the foreground (tty pgrp == our pgrp).
6092 * If we get started under a job aware app (like bash),
6093 * make sure we are now in charge so we don't fight over
6094 * who gets the foreground */
6096 shell_pgrp = getpgrp();
6097 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6098 if (G.saved_tty_pgrp == shell_pgrp)
6100 /* send TTIN to ourself (should stop us) */
6101 kill(- shell_pgrp, SIGTTIN);
6103 /* Block some signals */
6104 block_signals(signal_mask_is_inited);
6105 /* Set other signals to restore saved_tty_pgrp */
6106 set_fatal_handlers();
6107 /* Put ourselves in our own process group */
6108 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6109 /* Grab control of the terminal */
6110 tcsetpgrp(G_interactive_fd, getpid());
6111 /* -1 is special - makes xfuncs longjmp, not exit
6112 * (we reset die_sleep = 0 whereever we [v]fork) */
6113 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6114 } else if (!signal_mask_is_inited) {
6115 block_signals(0); /* 0: called 1st time */
6116 } /* else: block_signals(0) was done before */
6117 #elif ENABLE_HUSH_INTERACTIVE
6118 /* No job control compiled in, only prompt/line editing */
6119 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6120 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6121 if (G_interactive_fd < 0) {
6122 /* try to dup to any fd */
6123 G_interactive_fd = dup(STDIN_FILENO);
6124 if (G_interactive_fd < 0)
6126 G_interactive_fd = 0;
6129 if (G_interactive_fd) {
6130 close_on_exec_on(G_interactive_fd);
6131 block_signals(signal_mask_is_inited);
6132 } else if (!signal_mask_is_inited) {
6136 /* We have interactiveness code disabled */
6137 if (!signal_mask_is_inited) {
6142 * if interactive but not a login shell, sources ~/.bashrc
6143 * (--norc turns this off, --rcfile <file> overrides)
6146 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6147 printf("\n\n%s hush - the humble shell\n", bb_banner);
6148 printf("Enter 'help' for a list of built-in commands.\n\n");
6151 parse_and_run_file(stdin);
6154 #if ENABLE_FEATURE_CLEAN_UP
6155 if (G.cwd != bb_msg_unknown)
6157 cur_var = G.top_var->next;
6159 struct variable *tmp = cur_var;
6160 if (!cur_var->max_len)
6161 free(cur_var->varstr);
6162 cur_var = cur_var->next;
6166 hush_exit(G.last_exitcode);
6171 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6172 int lash_main(int argc, char **argv)
6174 //bb_error_msg("lash is deprecated, please use hush instead");
6175 return hush_main(argc, argv);
6183 static int builtin_trap(char **argv)
6190 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6194 /* No args: print all trapped. This isn't 100% correct as we
6195 * should be escaping the cmd so that it can be pasted back in
6197 for (i = 0; i < NSIG; ++i)
6199 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
6200 return EXIT_SUCCESS;
6205 /* If first arg is decimal: reset all specified signals */
6206 sig = bb_strtou(*argv, NULL, 10);
6212 sig = get_signum(*argv++);
6213 if (sig < 0 || sig >= NSIG) {
6215 /* Mimic bash message exactly */
6216 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
6221 G.traps[sig] = xstrdup(new_cmd);
6223 debug_printf("trap: setting SIG%s (%i) to '%s'",
6224 get_signame(sig), sig, G.traps[sig]);
6226 /* There is no signal for 0 (EXIT) */
6231 sigaddset(&G.blocked_set, sig);
6233 /* There was a trap handler, we are removing it
6234 * (if sig has non-DFL handling,
6235 * we don't need to do anything) */
6236 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6238 sigdelset(&G.blocked_set, sig);
6240 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6245 /* First arg is "-": reset all specified to default */
6246 /* First arg is "": ignore all specified */
6247 /* Everything else: execute first arg upon signal */
6249 bb_error_msg("trap: invalid arguments");
6250 return EXIT_FAILURE;
6252 if (NOT_LONE_DASH(*argv))
6258 static int builtin_true(char **argv UNUSED_PARAM)
6263 static int builtin_test(char **argv)
6270 return test_main(argc, argv - argc);
6273 static int builtin_echo(char **argv)
6280 return echo_main(argc, argv - argc);
6283 static int builtin_eval(char **argv)
6285 int rcode = EXIT_SUCCESS;
6288 char *str = expand_strvec_to_string(argv);
6290 * eval "echo Hi; done" ("done" is syntax error):
6291 * "echo Hi" will not execute too.
6293 parse_and_run_string(str);
6295 rcode = G.last_exitcode;
6300 static int builtin_cd(char **argv)
6302 const char *newdir = argv[1];
6303 if (newdir == NULL) {
6304 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6305 * bash says "bash: cd: HOME not set" and does nothing
6308 newdir = getenv("HOME") ? : "/";
6310 if (chdir(newdir)) {
6311 /* Mimic bash message exactly */
6312 bb_perror_msg("cd: %s", newdir);
6313 return EXIT_FAILURE;
6316 return EXIT_SUCCESS;
6319 static int builtin_exec(char **argv)
6321 if (*++argv == NULL)
6322 return EXIT_SUCCESS; /* bash does this */
6327 // FIXME: if exec fails, bash does NOT exit! We do...
6328 pseudo_exec_argv(&dummy, argv, 0, NULL);
6333 static int builtin_exit(char **argv)
6335 debug_printf_exec("%s()\n", __func__);
6336 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6337 //puts("exit"); /* bash does it */
6338 // TODO: warn if we have background jobs: "There are stopped jobs"
6339 // On second consecutive 'exit', exit anyway.
6340 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6342 /* note: EXIT trap is run by hush_exit */
6343 if (*++argv == NULL)
6344 hush_exit(G.last_exitcode);
6345 /* mimic bash: exit 123abc == exit 255 + error msg */
6346 xfunc_error_retval = 255;
6347 /* bash: exit -2 == exit 254, no error msg */
6348 hush_exit(xatoi(*argv) & 0xff);
6351 static int builtin_export(char **argv)
6353 if (*++argv == NULL) {
6360 /* ash emits: export VAR='VAL'
6361 * bash: declare -x VAR="VAL"
6362 * we follow ash example */
6363 const char *s = *e++;
6364 const char *p = strchr(s, '=');
6366 if (!p) /* wtf? take next variable */
6369 printf("export %.*s", (int)(p - s) + 1, s);
6373 p = strchrnul(s, '\'');
6375 printf("'%.*s'", (int)(p - s), s);
6380 /* s points to '; print ''...'''" */
6382 do putchar('\''); while (*++s == '\'');
6390 return EXIT_SUCCESS;
6397 value = strchr(name, '=');
6399 /* They are exporting something without a =VALUE */
6400 struct variable *var;
6402 var = get_local_var(name);
6404 var->flg_export = 1;
6405 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6406 putenv(var->varstr);
6408 /* bash does not return an error when trying to export
6409 * an undefined variable. Do likewise. */
6412 set_local_var(xstrdup(name), 1, 0);
6415 return EXIT_SUCCESS;
6419 /* built-in 'fg' and 'bg' handler */
6420 static int builtin_fg_bg(char **argv)
6425 if (!G_interactive_fd)
6426 return EXIT_FAILURE;
6427 /* If they gave us no args, assume they want the last backgrounded task */
6429 for (pi = G.job_list; pi; pi = pi->next) {
6430 if (pi->jobid == G.last_jobid) {
6434 bb_error_msg("%s: no current job", argv[0]);
6435 return EXIT_FAILURE;
6437 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6438 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6439 return EXIT_FAILURE;
6441 for (pi = G.job_list; pi; pi = pi->next) {
6442 if (pi->jobid == jobnum) {
6446 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6447 return EXIT_FAILURE;
6449 // TODO: bash prints a string representation
6450 // of job being foregrounded (like "sleep 1 | cat")
6451 if (argv[0][0] == 'f') {
6452 /* Put the job into the foreground. */
6453 tcsetpgrp(G_interactive_fd, pi->pgrp);
6456 /* Restart the processes in the job */
6457 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6458 for (i = 0; i < pi->num_cmds; i++) {
6459 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6460 pi->cmds[i].is_stopped = 0;
6462 pi->stopped_cmds = 0;
6464 i = kill(- pi->pgrp, SIGCONT);
6466 if (errno == ESRCH) {
6467 delete_finished_bg_job(pi);
6468 return EXIT_SUCCESS;
6470 bb_perror_msg("kill (SIGCONT)");
6473 if (argv[0][0] == 'f') {
6475 return checkjobs_and_fg_shell(pi);
6477 return EXIT_SUCCESS;
6481 #if ENABLE_HUSH_HELP
6482 static int builtin_help(char **argv UNUSED_PARAM)
6484 const struct built_in_command *x;
6487 "Built-in commands:\n"
6488 "------------------\n");
6489 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6490 printf("%s\t%s\n", x->cmd, x->descr);
6493 return EXIT_SUCCESS;
6498 static int builtin_jobs(char **argv UNUSED_PARAM)
6501 const char *status_string;
6503 for (job = G.job_list; job; job = job->next) {
6504 if (job->alive_cmds == job->stopped_cmds)
6505 status_string = "Stopped";
6507 status_string = "Running";
6509 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6511 return EXIT_SUCCESS;
6516 static int builtin_memleak(char **argv UNUSED_PARAM)
6521 /* Crude attempt to find where "free memory" starts,
6522 * sans fragmentation. */
6524 l = (unsigned long)p;
6527 if (l < (unsigned long)p) l = (unsigned long)p;
6530 if (!G.memleak_value)
6531 G.memleak_value = l;
6533 l -= G.memleak_value;
6540 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6545 static int builtin_pwd(char **argv UNUSED_PARAM)
6548 return EXIT_SUCCESS;
6551 static int builtin_read(char **argv)
6554 const char *name = "REPLY";
6558 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6559 * and _after_ that_ it will complain */
6560 if (!is_well_formed_var_name(name, '\0')) {
6561 /* Mimic bash message */
6562 bb_error_msg("read: '%s': not a valid identifier", name);
6567 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6569 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6570 return set_local_var(string, 0, 0);
6573 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6574 * built-in 'set' handler
6576 * set [-abCefhmnuvx] [-o option] [argument...]
6577 * set [+abCefhmnuvx] [+o option] [argument...]
6578 * set -- [argument...]
6581 * Implementations shall support the options in both their hyphen and
6582 * plus-sign forms. These options can also be specified as options to sh.
6584 * Write out all variables and their values: set
6585 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6586 * Turn on the -x and -v options: set -xv
6587 * Unset all positional parameters: set --
6588 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6589 * Set the positional parameters to the expansion of x, even if x expands
6590 * with a leading '-' or '+': set -- $x
6592 * So far, we only support "set -- [argument...]" and some of the short names.
6594 static int builtin_set(char **argv)
6597 char **pp, **g_argv;
6598 char *arg = *++argv;
6602 for (e = G.top_var; e; e = e->next)
6604 return EXIT_SUCCESS;
6608 if (!strcmp(arg, "--")) {
6612 if (arg[0] != '+' && arg[0] != '-')
6614 for (n = 1; arg[n]; ++n)
6615 if (set_mode(arg[0], arg[n]))
6617 } while ((arg = *++argv) != NULL);
6618 /* Now argv[0] is 1st argument */
6621 return EXIT_SUCCESS;
6624 /* NB: G.global_argv[0] ($0) is never freed/changed */
6625 g_argv = G.global_argv;
6626 if (G.global_args_malloced) {
6632 G.global_args_malloced = 1;
6633 pp = xzalloc(sizeof(pp[0]) * 2);
6634 pp[0] = g_argv[0]; /* retain $0 */
6637 /* This realloc's G.global_argv */
6638 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6645 return EXIT_SUCCESS;
6647 /* Nothing known, so abort */
6649 bb_error_msg("set: %s: invalid option", arg);
6650 return EXIT_FAILURE;
6653 static int builtin_shift(char **argv)
6659 if (n >= 0 && n < G.global_argc) {
6660 if (G.global_args_malloced) {
6663 free(G.global_argv[m++]);
6666 memmove(&G.global_argv[1], &G.global_argv[n+1],
6667 G.global_argc * sizeof(G.global_argv[0]));
6668 return EXIT_SUCCESS;
6670 return EXIT_FAILURE;
6673 static int builtin_source(char **argv)
6677 if (*++argv == NULL)
6678 return EXIT_FAILURE;
6680 /* XXX search through $PATH is missing */
6681 input = fopen_or_warn(*argv, "r");
6683 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6684 return EXIT_FAILURE;
6686 close_on_exec_on(fileno(input));
6688 /* Now run the file */
6690 /* XXX argv and argc are broken; need to save old G.global_argv
6691 * (pointer only is OK!) on this stack frame,
6692 * set G.global_argv=argv+1, recurse, and restore. */
6693 parse_and_run_file(input);
6695 return G.last_exitcode;
6698 static int builtin_umask(char **argv)
6701 const char *arg = argv[1];
6703 //TODO: umask may take chmod-like symbolic masks
6704 new_umask = bb_strtou(arg, NULL, 8);
6706 //Message? bash examples:
6707 //bash: umask: 'q': invalid symbolic mode operator
6708 //bash: umask: 999: octal number out of range
6709 return EXIT_FAILURE;
6712 new_umask = umask(0);
6713 printf("%.3o\n", (unsigned) new_umask);
6714 /* fall through and restore new_umask which we set to 0 */
6717 return EXIT_SUCCESS;
6720 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6721 static int builtin_unset(char **argv)
6727 return EXIT_SUCCESS;
6730 if (argv[0][0] == '-') {
6731 switch (argv[0][1]) {
6737 bb_error_msg("unset: %s: invalid option", *argv);
6738 return EXIT_FAILURE;
6740 //TODO: disallow "unset -vf ..." too
6747 if (unset_local_var(*argv)) {
6748 /* unset <nonexistent_var> doesn't fail.
6749 * Error is when one tries to unset RO var.
6750 * Message was printed by unset_local_var. */
6754 //#if ENABLE_HUSH_FUNCTIONS
6756 // unset_local_func(*argv);
6764 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6765 static int builtin_wait(char **argv)
6767 int ret = EXIT_SUCCESS;
6770 if (*++argv == NULL) {
6771 /* Don't care about wait results */
6772 /* Note 1: must wait until there are no more children */
6773 /* Note 2: must be interruptible */
6775 * $ sleep 3 & sleep 6 & wait
6780 * $ sleep 3 & sleep 6 & wait
6784 * ^C <-- after ~4 sec from keyboard
6787 sigaddset(&G.blocked_set, SIGCHLD);
6788 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6791 if (errno == ECHILD)
6793 /* Wait for SIGCHLD or any other signal of interest */
6794 /* sigtimedwait with infinite timeout: */
6795 sig = sigwaitinfo(&G.blocked_set, NULL);
6797 sig = check_and_run_traps(sig);
6798 if (sig && sig != SIGCHLD) { /* see note 2 */
6804 sigdelset(&G.blocked_set, SIGCHLD);
6805 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6809 /* This is probably buggy wrt interruptible-ness */
6811 pid_t pid = bb_strtou(*argv, NULL, 10);
6813 /* mimic bash message */
6814 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6815 return EXIT_FAILURE;
6817 if (waitpid(pid, &status, 0) == pid) {
6818 if (WIFSIGNALED(status))
6819 ret = 128 + WTERMSIG(status);
6820 else if (WIFEXITED(status))
6821 ret = WEXITSTATUS(status);
6825 bb_perror_msg("wait %s", *argv);
6834 #if ENABLE_HUSH_LOOPS
6835 static int builtin_break(char **argv)
6837 if (G.depth_of_loop == 0) {
6838 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6839 return EXIT_SUCCESS; /* bash compat */
6841 G.flag_break_continue++; /* BC_BREAK = 1 */
6842 G.depth_break_continue = 1;
6844 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6845 if (errno || !G.depth_break_continue || argv[2]) {
6846 bb_error_msg("%s: bad arguments", argv[0]);
6847 G.flag_break_continue = BC_BREAK;
6848 G.depth_break_continue = UINT_MAX;
6851 if (G.depth_of_loop < G.depth_break_continue)
6852 G.depth_break_continue = G.depth_of_loop;
6853 return EXIT_SUCCESS;
6856 static int builtin_continue(char **argv)
6858 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6859 return builtin_break(argv);