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
46 * Bash stuff (maybe optionally enable?):
47 * &> and >& redirection of stdout+stderr
49 * reserved words: [[ ]] function select
50 * substrings ${var:1:5}
53 * grep for "TODO" and fix (some of them are easy)
54 * change { and } from special chars to reserved words
55 * builtins: return, ulimit
56 * follow IFS rules more precisely, including update semantics
57 * figure out what to do with backslash-newline
58 * continuation lines, both explicit and implicit - done?
60 * ^Z handling (and explain it in comments for mere humans)
61 * separate job control from interactiveness
62 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
65 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
67 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
69 /* #include <dmalloc.h> */
76 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
80 /* Debug build knobs */
81 #define LEAK_HUNTING 0
82 #define BUILD_AS_NOMMU 0
83 /* Enable/disable sanity checks. Ok to enable in production,
84 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
85 * Keeping 1 for now even in released versions.
89 #define ENABLE_HUSH_FUNCTIONS 1
97 # define USE_FOR_NOMMU(...) __VA_ARGS__
98 # define USE_FOR_MMU(...)
101 #if defined SINGLE_APPLET_MAIN
102 /* STANDALONE does not make sense, and won't compile */
103 # undef CONFIG_FEATURE_SH_STANDALONE
104 # undef ENABLE_FEATURE_SH_STANDALONE
105 # undef USE_FEATURE_SH_STANDALONE
106 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
107 # define ENABLE_FEATURE_SH_STANDALONE 0
108 # define USE_FEATURE_SH_STANDALONE(...)
109 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
112 #if !ENABLE_HUSH_INTERACTIVE
113 # undef ENABLE_FEATURE_EDITING
114 # define ENABLE_FEATURE_EDITING 0
115 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
116 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
119 /* Do we support ANY keywords? */
120 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
121 # define HAS_KEYWORDS 1
122 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
123 # define IF_HAS_NO_KEYWORDS(...)
125 # define HAS_KEYWORDS 0
126 # define IF_HAS_KEYWORDS(...)
127 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
130 /* If you comment out one of these below, it will be #defined later
131 * to perform debug printfs to stderr: */
132 #define debug_printf(...) do {} while (0)
133 /* Finer-grained debug switches */
134 #define debug_printf_parse(...) do {} while (0)
135 #define debug_print_tree(a, b) do {} while (0)
136 #define debug_printf_exec(...) do {} while (0)
137 #define debug_printf_env(...) do {} while (0)
138 #define debug_printf_jobs(...) do {} while (0)
139 #define debug_printf_expand(...) do {} while (0)
140 #define debug_printf_glob(...) do {} while (0)
141 #define debug_printf_list(...) do {} while (0)
142 #define debug_printf_subst(...) do {} while (0)
143 #define debug_printf_clean(...) do {} while (0)
146 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
149 #ifndef debug_printf_parse
150 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
153 #ifndef debug_printf_exec
154 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
157 #ifndef debug_printf_env
158 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
161 #ifndef debug_printf_jobs
162 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
168 #ifndef debug_printf_expand
169 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
170 #define DEBUG_EXPAND 1
172 #define DEBUG_EXPAND 0
175 #ifndef debug_printf_glob
176 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
182 #ifndef debug_printf_list
183 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
186 #ifndef debug_printf_subst
187 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
190 #ifndef debug_printf_clean
191 /* broken, of course, but OK for testing */
192 static const char *indenter(int i)
194 static const char blanks[] ALIGN1 =
196 return &blanks[sizeof(blanks) - i - 1];
198 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
199 #define DEBUG_CLEAN 1
201 #define DEBUG_CLEAN 0
205 static void debug_print_strings(const char *prefix, char **vv)
207 fprintf(stderr, "%s:\n", prefix);
209 fprintf(stderr, " '%s'\n", *vv++);
212 #define debug_print_strings(prefix, vv) ((void)0)
215 #define ERR_PTR ((void*)(long)1)
217 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
219 #define SPECIAL_VAR_SYMBOL 3
221 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
223 /* This supports saving pointers malloced in vfork child,
224 * to be freed in the parent. One pointer is saved in
225 * G.argv_from_re_execing global var instead. TODO: unify.
228 typedef struct nommu_save_t {
235 /* The descrip member of this structure is only used to make
236 * debugging output pretty */
237 static const struct {
239 signed char default_fd;
243 { O_RDONLY, 0, "<" },
244 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
245 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
246 { O_RDONLY, 0, "<<" },
247 { O_CREAT|O_RDWR, 1, "<>" },
248 /* Should not be needed. Bogus default_fd helps in debugging */
249 /* { O_RDONLY, 77, "<<" }, */
252 typedef enum reserved_style {
261 #if ENABLE_HUSH_LOOPS
268 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
273 /* two pseudo-keywords support contrived "case" syntax: */
274 RES_MATCH , /* "word)" */
275 RES_CASEI , /* "this command is inside CASE" */
282 typedef struct o_string {
284 int length; /* position where data is appended */
286 /* Protect newly added chars against globbing
287 * (by prepending \ to *, ?, [, \) */
290 /* At least some part of the string was inside '' or "",
291 * possibly empty one: word"", wo''rd etc. */
293 smallint has_empty_slot;
294 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
297 MAYBE_ASSIGNMENT = 0,
298 DEFINITELY_ASSIGNMENT = 1,
300 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
302 /* Used for initialization: o_string foo = NULL_O_STRING; */
303 #define NULL_O_STRING { NULL }
305 /* I can almost use ordinary FILE*. Is open_memstream() universally
306 * available? Where is it documented? */
307 typedef struct in_str {
309 /* eof_flag=1: last char in ->p is really an EOF */
310 char eof_flag; /* meaningless if ->p == NULL */
312 #if ENABLE_HUSH_INTERACTIVE
314 smallint promptmode; /* 0: PS1, 1: PS2 */
317 int (*get) (struct in_str *);
318 int (*peek) (struct in_str *);
320 #define i_getch(input) ((input)->get(input))
321 #define i_peek(input) ((input)->peek(input))
323 struct redir_struct {
324 struct redir_struct *next;
325 char *rd_filename; /* filename */
326 int rd_fd; /* fd to redirect */
327 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
329 smallint rd_type; /* (enum redir_type) */
330 /* note: for heredocs, rd_filename contains heredoc delimiter,
331 * and subsequently heredoc itself; and rd_dup is a bitmask:
332 * 1: do we need to trim leading tabs?
333 * 2: is heredoc quoted (<<'delim' syntax) ?
336 typedef enum redir_type {
337 REDIRECT_INVALID = 0,
339 REDIRECT_OVERWRITE = 2,
341 REDIRECT_HEREDOC = 4,
343 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
346 REDIRFD_SYNTAX_ERR = -2,
347 REDIRFD_TO_FILE = -1,
348 /* otherwise, rd_fd is redirected to rd_dup */
350 HEREDOC_SKIPTABS = 1,
356 pid_t pid; /* 0 if exited */
357 int assignment_cnt; /* how many argv[i] are assignments? */
358 smallint is_stopped; /* is the command currently running? */
359 smallint grp_type; /* GRP_xxx */
361 #define GRP_SUBSHELL 1
362 #if ENABLE_HUSH_FUNCTIONS
363 # define GRP_FUNCTION 2
365 struct pipe *group; /* if non-NULL, this "command" is { list },
366 * ( list ), or a compound statement */
368 char *group_as_string;
370 #if ENABLE_HUSH_FUNCTIONS
371 struct function *child_func;
372 /* This field is used to prevent a bug here:
373 * while...do f1() {a;}; f1; f1 {b;}; f1; done
374 * When we execute "f1() {a;}" cmd, we create new function and clear
375 * cmd->group, cmd->group_as_string, cmd->argv[0].
376 * when we execute "f1 {b;}", we notice that f1 exists,
377 * and that it's "parent cmd" struct is still "alive",
378 * we put those fields back into cmd->xxx
379 * (struct function has ->parent_cmd ptr to facilitate that).
380 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
381 * Without this trick, loop would execute a;b;b;b;...
382 * instead of correct sequence a;b;a;b;...
383 * When command is freed, it severs the link
384 * (sets ->child_func->parent_cmd to NULL).
387 char **argv; /* command name and arguments */
388 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
389 * and on execution these are substituted with their values.
390 * Substitution can make _several_ words out of one argv[n]!
391 * Example: argv[0]=='.^C*^C.' here: echo .$*.
392 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
394 struct redir_struct *redirects; /* I/O redirections */
399 int num_cmds; /* total number of commands in pipe */
400 int alive_cmds; /* number of commands running (not exited) */
401 int stopped_cmds; /* number of commands alive, but stopped */
403 int jobid; /* job number */
404 pid_t pgrp; /* process group ID for the job */
405 char *cmdtext; /* name of job */
407 struct command *cmds; /* array of commands in pipe */
408 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
409 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
410 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
412 typedef enum pipe_style {
419 /* This holds pointers to the various results of parsing */
420 struct parse_context {
421 /* linked list of pipes */
422 struct pipe *list_head;
423 /* last pipe (being constructed right now) */
425 /* last command in pipe (being constructed right now) */
426 struct command *command;
427 /* last redirect in command->redirects list */
428 struct redir_struct *pending_redirect;
434 smallint ctx_inverted; /* "! cmd | cmd" */
436 smallint ctx_dsemicolon; /* ";;" seen */
438 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
440 /* group we are enclosed in:
441 * example: "if pipe1; pipe2; then pipe3; fi"
442 * when we see "if" or "then", we malloc and copy current context,
443 * and make ->stack point to it. then we parse pipeN.
444 * when closing "then" / fi" / whatever is found,
445 * we move list_head into ->stack->command->group,
446 * copy ->stack into current context, and delete ->stack.
447 * (parsing of { list } and ( list ) doesn't use this method)
449 struct parse_context *stack;
453 /* On program start, environ points to initial environment.
454 * putenv adds new pointers into it, unsetenv removes them.
455 * Neither of these (de)allocates the strings.
456 * setenv allocates new strings in malloc space and does putenv,
457 * and thus setenv is unusable (leaky) for shell's purposes */
458 #define setenv(...) setenv_is_leaky_dont_use()
460 struct variable *next;
461 char *varstr; /* points to "name=" portion */
462 int max_len; /* if > 0, name is part of initial env; else name is malloced */
463 smallint flg_export; /* putenv should be done on this var */
464 smallint flg_read_only;
472 #if ENABLE_HUSH_FUNCTIONS
474 struct function *next;
476 struct command *parent_cmd;
479 char *body_as_string;
485 /* "Globals" within this file */
486 /* Sorted roughly by size (smaller offsets == smaller code) */
488 #if ENABLE_HUSH_INTERACTIVE
489 /* 'interactive_fd' is a fd# open to ctty, if we have one
490 * _AND_ if we decided to act interactively */
494 #define G_interactive_fd (G.interactive_fd)
496 #define G_interactive_fd 0
498 #if ENABLE_FEATURE_EDITING
499 line_input_t *line_input_state;
505 pid_t saved_tty_pgrp;
507 struct pipe *job_list;
508 struct pipe *toplevel_list;
509 //// smallint ctrl_z_flag;
511 smallint flag_SIGINT;
512 #if ENABLE_HUSH_LOOPS
513 smallint flag_break_continue;
516 smallint exiting; /* used to prevent EXIT trap recursion */
517 /* These four support $?, $#, and $1 */
518 smalluint last_exitcode;
519 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
520 smalluint global_args_malloced;
521 /* how many non-NULL argv's we have. NB: $# + 1 */
525 char *argv0_for_re_execing;
526 char **argv_from_re_execing;
528 #if ENABLE_HUSH_LOOPS
529 unsigned depth_break_continue;
530 unsigned depth_of_loop;
534 struct variable *top_var; /* = &G.shell_ver (set in main()) */
535 struct variable shell_ver;
536 #if ENABLE_HUSH_FUNCTIONS
537 struct function *top_func;
539 /* Signal and trap handling */
540 // unsigned count_SIGCHLD;
541 // unsigned handled_SIGCHLD;
542 /* which signals have non-DFL handler (even with no traps set)? */
543 unsigned non_DFL_mask;
544 char **traps; /* char *traps[NSIG] */
545 sigset_t blocked_set;
546 sigset_t inherited_set;
548 unsigned long memleak_value;
550 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
551 #if ENABLE_FEATURE_SH_STANDALONE
552 struct nofork_save_area nofork_save;
555 sigjmp_buf toplevel_jb;
558 #define G (*ptr_to_globals)
559 /* Not #defining name to G.name - this quickly gets unwieldy
560 * (too many defines). Also, I actually prefer to see when a variable
561 * is global, thus "G." prefix is a useful hint */
562 #define INIT_G() do { \
563 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
567 /* Function prototypes for builtins */
568 static int builtin_cd(char **argv);
569 static int builtin_echo(char **argv);
570 static int builtin_eval(char **argv);
571 static int builtin_exec(char **argv);
572 static int builtin_exit(char **argv);
573 static int builtin_export(char **argv);
575 static int builtin_fg_bg(char **argv);
576 static int builtin_jobs(char **argv);
579 static int builtin_help(char **argv);
582 static int builtin_memleak(char **argv);
584 static int builtin_pwd(char **argv);
585 static int builtin_read(char **argv);
586 static int builtin_set(char **argv);
587 static int builtin_shift(char **argv);
588 static int builtin_source(char **argv);
589 static int builtin_test(char **argv);
590 static int builtin_trap(char **argv);
591 static int builtin_true(char **argv);
592 static int builtin_umask(char **argv);
593 static int builtin_unset(char **argv);
594 static int builtin_wait(char **argv);
595 #if ENABLE_HUSH_LOOPS
596 static int builtin_break(char **argv);
597 static int builtin_continue(char **argv);
600 /* Table of built-in functions. They can be forked or not, depending on
601 * context: within pipes, they fork. As simple commands, they do not.
602 * When used in non-forking context, they can change global variables
603 * in the parent shell process. If forked, of course they cannot.
604 * For example, 'unset foo | whatever' will parse and run, but foo will
605 * still be set at the end. */
606 struct built_in_command {
608 int (*function)(char **argv);
611 #define BLTIN(cmd, func, help) { cmd, func, help }
613 #define BLTIN(cmd, func, help) { cmd, func }
617 /* For now, echo and test are unconditionally enabled.
618 * Maybe make it configurable? */
619 static const struct built_in_command bltins[] = {
620 BLTIN("." , builtin_source , "Run commands in a file"),
621 BLTIN(":" , builtin_true , "No-op"),
622 BLTIN("[" , builtin_test , "Test condition"),
624 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
626 #if ENABLE_HUSH_LOOPS
627 BLTIN("break" , builtin_break , "Exit from a loop"),
629 BLTIN("cd" , builtin_cd , "Change directory"),
630 #if ENABLE_HUSH_LOOPS
631 BLTIN("continue", builtin_continue, "Start new loop iteration"),
633 BLTIN("echo" , builtin_echo , "Write to stdout"),
634 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
635 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
636 BLTIN("exit" , builtin_exit , "Exit"),
637 BLTIN("export" , builtin_export , "Set environment variable"),
639 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
642 BLTIN("help" , builtin_help , "List shell built-in commands"),
645 BLTIN("jobs" , builtin_jobs , "List active jobs"),
648 BLTIN("memleak" , builtin_memleak , "Debug tool"),
650 BLTIN("pwd" , builtin_pwd , "Print current directory"),
651 BLTIN("read" , builtin_read , "Input environment variable"),
652 // BLTIN("return" , builtin_return , "Return from a function"),
653 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
654 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
655 BLTIN("test" , builtin_test , "Test condition"),
656 BLTIN("trap" , builtin_trap , "Trap signals"),
657 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
658 BLTIN("umask" , builtin_umask , "Set file creation mask"),
659 BLTIN("unset" , builtin_unset , "Unset environment variable"),
660 BLTIN("wait" , builtin_wait , "Wait for process"),
664 /* Leak hunting. Use hush_leaktool.sh for post-processing.
667 static void *xxmalloc(int lineno, size_t size)
669 void *ptr = xmalloc((size + 0xff) & ~0xff);
670 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
673 static void *xxrealloc(int lineno, void *ptr, size_t size)
675 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
676 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
679 static char *xxstrdup(int lineno, const char *str)
681 char *ptr = xstrdup(str);
682 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
685 static void xxfree(void *ptr)
687 fdprintf(2, "free %p\n", ptr);
690 #define xmalloc(s) xxmalloc(__LINE__, s)
691 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
692 #define xstrdup(s) xxstrdup(__LINE__, s)
693 #define free(p) xxfree(p)
697 /* Syntax and runtime errors. They always abort scripts.
698 * In interactive use they usually discard unparsed and/or unexecuted commands
699 * and return to the prompt.
700 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
703 # define die_if_script(lineno, fmt...) die_if_script(fmt)
704 # define syntax_error(lineno, msg) syntax_error(msg)
705 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
706 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
707 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
708 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
711 static void die_if_script(unsigned lineno, const char *fmt, ...)
716 bb_error_msg("hush.c:%u", lineno);
719 bb_verror_msg(fmt, p, NULL);
721 if (!G_interactive_fd)
725 static void syntax_error(unsigned lineno, const char *msg)
728 die_if_script(lineno, "syntax error: %s", msg);
730 die_if_script(lineno, "syntax error", NULL);
733 static void syntax_error_at(unsigned lineno, const char *msg)
735 die_if_script(lineno, "syntax error at '%s'", msg);
738 /* It so happens that all such cases are totally fatal
739 * even if shell is interactive: EOF while looking for closing
740 * delimiter. There is nowhere to read stuff from after that,
741 * it's EOF! The only choice is to terminate.
743 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
744 static void syntax_error_unterm_ch(unsigned lineno, char ch)
749 die_if_script(lineno, "syntax error: unterminated %s", msg);
753 static void syntax_error_unterm_str(unsigned lineno, const char *s)
755 die_if_script(lineno, "syntax error: unterminated %s", s);
758 static void syntax_error_unexpected_ch(unsigned lineno, char ch)
763 die_if_script(lineno, "syntax error: unexpected %s", msg);
767 # undef die_if_script
769 # undef syntax_error_at
770 # undef syntax_error_unterm_ch
771 # undef syntax_error_unterm_str
772 # undef syntax_error_unexpected_ch
774 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
775 # define syntax_error(msg) syntax_error(__LINE__, msg)
776 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
777 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
778 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
779 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
785 static int glob_needed(const char *s)
790 if (*s == '*' || *s == '[' || *s == '?')
797 static int is_well_formed_var_name(const char *s, char terminator)
799 if (!s || !(isalpha(*s) || *s == '_'))
802 while (isalnum(*s) || *s == '_')
804 return *s == terminator;
807 /* Replace each \x with x in place, return ptr past NUL. */
808 static char *unbackslash(char *src)
814 if ((*dst++ = *src++) == '\0')
820 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
841 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
842 v[count1 + count2] = NULL;
845 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
849 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
851 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
852 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
855 #define add_strings_to_strings(strings, add, need_to_dup) \
856 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
859 static char **add_string_to_strings(char **strings, char *add)
864 return add_strings_to_strings(strings, v, /*dup:*/ 0);
867 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
869 char **ptr = add_string_to_strings(strings, add);
870 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
873 #define add_string_to_strings(strings, add) \
874 xx_add_string_to_strings(__LINE__, strings, add)
877 static void putenv_all(char **strings)
882 debug_printf_env("putenv '%s'\n", *strings);
887 static char **putenv_all_and_save_old(char **strings)
897 eq = strchr(*strings, '=');
900 v = getenv(*strings);
903 /* v points to VAL in VAR=VAL, go back to VAR */
904 v -= (eq - *strings) + 1;
905 old = add_string_to_strings(old, v);
914 static void free_strings_and_unsetenv(char **strings, int unset)
924 debug_printf_env("unsetenv '%s'\n", *v);
932 static void free_strings(char **strings)
934 free_strings_and_unsetenv(strings, 0);
938 /* Basic theory of signal handling in shell
939 * ========================================
940 * This does not describe what hush does, rather, it is current understanding
941 * what it _should_ do. If it doesn't, it's a bug.
942 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
944 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
945 * is finished or backgrounded. It is the same in interactive and
946 * non-interactive shells, and is the same regardless of whether
947 * a user trap handler is installed or a shell special one is in effect.
948 * ^C or ^Z from keyboard seem to execute "at once" because it usually
949 * backgrounds (i.e. stops) or kills all members of currently running
952 * Wait builtin in interruptible by signals for which user trap is set
953 * or by SIGINT in interactive shell.
955 * Trap handlers will execute even within trap handlers. (right?)
957 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
959 * If job control is off, backgrounded commands ("cmd &")
960 * have SIGINT, SIGQUIT set to SIG_IGN.
962 * Commands run in command substitution ("`cmd`")
963 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
965 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
966 * by the shell from its parent.
968 * Siganls which differ from SIG_DFL action
969 * (note: child (i.e., [v]forked) shell is not an interactive shell):
972 * SIGTERM (interactive): ignore
973 * SIGHUP (interactive):
974 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
975 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
976 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
977 * that all pipe members are stopped) (right?)
978 * SIGINT (interactive): wait for last pipe, ignore the rest
979 * of the command line, show prompt. NB: ^C does not send SIGINT
980 * to interactive shell while shell is waiting for a pipe,
981 * since shell is bg'ed (is not in foreground process group).
982 * (check/expand this)
983 * Example 1: this waits 5 sec, but does not execute ls:
984 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
985 * Example 2: this does not wait and does not execute ls:
986 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
987 * Example 3: this does not wait 5 sec, but executes ls:
988 * "sleep 5; ls -l" + press ^C
990 * (What happens to signals which are IGN on shell start?)
991 * (What happens with signal mask on shell start?)
993 * Implementation in hush
994 * ======================
995 * We use in-kernel pending signal mask to determine which signals were sent.
996 * We block all signals which we don't want to take action immediately,
997 * i.e. we block all signals which need to have special handling as described
998 * above, and all signals which have traps set.
999 * After each pipe execution, we extract any pending signals via sigtimedwait()
1002 * unsigned non_DFL_mask: a mask of such "special" signals
1003 * sigset_t blocked_set: current blocked signal set
1006 * clear bit in blocked_set unless it is also in non_DFL_mask
1007 * "trap 'cmd' SIGxxx":
1008 * set bit in blocked_set (even if 'cmd' is '')
1009 * after [v]fork, if we plan to be a shell:
1010 * nothing for {} child shell (say, "true | { true; true; } | true")
1011 * unset all traps if () shell.
1012 * after [v]fork, if we plan to exec:
1013 * POSIX says pending signal mask is cleared in child - no need to clear it.
1014 * Restore blocked signal set to one inherited by shell just prior to exec.
1016 * Note: as a result, we do not use signal handlers much. The only uses
1017 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
1018 * and to restore tty pgrp on signal-induced exit.
1021 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1023 // G.count_SIGCHLD++;
1026 static int check_and_run_traps(int sig)
1028 static const struct timespec zero_timespec = { 0, 0 };
1029 smalluint save_rcode;
1035 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1040 if (G.traps && G.traps[sig]) {
1041 if (G.traps[sig][0]) {
1042 /* We have user-defined handler */
1043 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1044 save_rcode = G.last_exitcode;
1047 G.last_exitcode = save_rcode;
1048 } /* else: "" trap, ignoring signal */
1051 /* not a trap: special action */
1054 // G.count_SIGCHLD++;
1063 default: /* ignored: */
1064 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1073 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1074 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1075 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1076 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1078 /* Restores tty foreground process group, and exits.
1079 * May be called as signal handler for fatal signal
1080 * (will faithfully resend signal to itself, producing correct exit state)
1081 * or called directly with -EXITCODE.
1082 * We also call it if xfunc is exiting. */
1083 static void sigexit(int sig) NORETURN;
1084 static void sigexit(int sig)
1086 /* Disable all signals: job control, SIGPIPE, etc. */
1087 sigprocmask_allsigs(SIG_BLOCK);
1089 /* Careful: we can end up here after [v]fork. Do not restore
1090 * tty pgrp then, only top-level shell process does that */
1091 if (G_interactive_fd && getpid() == G.root_pid)
1092 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1094 /* Not a signal, just exit */
1098 kill_myself_with_sig(sig); /* does not return */
1102 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1103 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1107 /* Restores tty foreground process group, and exits. */
1108 static void hush_exit(int exitcode) NORETURN;
1109 static void hush_exit(int exitcode)
1111 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1112 /* Prevent recursion:
1113 * trap "echo Hi; exit" EXIT; exit
1115 char *argv[] = { NULL, G.traps[0], NULL };
1123 fflush(NULL); /* flush all streams */
1124 sigexit(- (exitcode & 0xff));
1131 static const char *set_cwd(void)
1133 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1134 * we must not try to free(bb_msg_unknown) */
1135 if (G.cwd == bb_msg_unknown)
1137 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1139 G.cwd = bb_msg_unknown;
1144 /* Get/check local shell variables */
1145 static struct variable *get_local_var(const char *name)
1147 struct variable *cur;
1153 for (cur = G.top_var; cur; cur = cur->next) {
1154 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1160 static const char *get_local_var_value(const char *src)
1162 struct variable *var = get_local_var(src);
1164 return strchr(var->varstr, '=') + 1;
1168 /* str holds "NAME=VAL" and is expected to be malloced.
1169 * We take ownership of it.
1173 * -1: if NAME is set, leave export status alone
1174 * if NAME is not set, do not export
1175 * flg_read_only is set only when we handle -R var=val
1178 #define set_local_var(str, flg_export, flg_read_only) \
1179 set_local_var(str, flg_export)
1181 static int set_local_var(char *str, int flg_export, int flg_read_only)
1183 struct variable *cur;
1187 value = strchr(str, '=');
1188 if (!value) { /* not expected to ever happen? */
1193 name_len = value - str + 1; /* including '=' */
1194 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1196 if (strncmp(cur->varstr, str, name_len) != 0) {
1198 /* Bail out. Note that now cur points
1199 * to last var in linked list */
1205 /* We found an existing var with this name */
1207 if (cur->flg_read_only) {
1211 bb_error_msg("%s: readonly variable", str);
1215 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1216 unsetenv(str); /* just in case */
1218 if (strcmp(cur->varstr, str) == 0) {
1223 if (cur->max_len >= strlen(str)) {
1224 /* This one is from startup env, reuse space */
1225 strcpy(cur->varstr, str);
1228 /* max_len == 0 signifies "malloced" var, which we can
1229 * (and has to) free */
1233 goto set_str_and_exp;
1236 /* Not found - create next variable struct */
1237 cur->next = xzalloc(sizeof(*cur));
1243 cur->flg_read_only = flg_read_only;
1246 if (flg_export == 1)
1247 cur->flg_export = 1;
1248 if (cur->flg_export) {
1249 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1250 return putenv(cur->varstr);
1255 static int unset_local_var(const char *name)
1257 struct variable *cur;
1258 struct variable *prev = prev; /* for gcc */
1262 return EXIT_SUCCESS;
1263 name_len = strlen(name);
1266 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1267 if (cur->flg_read_only) {
1268 bb_error_msg("%s: readonly variable", name);
1269 return EXIT_FAILURE;
1271 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1272 * is ro, and we cannot reach this code on the 1st pass */
1273 prev->next = cur->next;
1274 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1275 bb_unsetenv(cur->varstr);
1279 return EXIT_SUCCESS;
1284 return EXIT_SUCCESS;
1287 #if ENABLE_SH_MATH_SUPPORT
1288 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1289 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1290 static char *endofname(const char *name)
1298 if (!is_in_name(*p))
1304 static void arith_set_local_var(const char *name, const char *val, int flags)
1306 /* arith code doesnt malloc space, so do it for it */
1307 char *var = xasprintf("%s=%s", name, val);
1308 set_local_var(var, flags, 0);
1316 static int static_get(struct in_str *i)
1325 static int static_peek(struct in_str *i)
1330 #if ENABLE_HUSH_INTERACTIVE
1332 static void cmdedit_set_initial_prompt(void)
1334 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1335 G.PS1 = getenv("PS1");
1342 static const char* setup_prompt_string(int promptmode)
1344 const char *prompt_str;
1345 debug_printf("setup_prompt_string %d ", promptmode);
1346 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1347 /* Set up the prompt */
1348 if (promptmode == 0) { /* PS1 */
1350 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1355 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1356 debug_printf("result '%s'\n", prompt_str);
1360 static void get_user_input(struct in_str *i)
1363 const char *prompt_str;
1365 prompt_str = setup_prompt_string(i->promptmode);
1366 #if ENABLE_FEATURE_EDITING
1367 /* Enable command line editing only while a command line
1368 * is actually being read */
1371 /* buglet: SIGINT will not make new prompt to appear _at once_,
1372 * only after <Enter>. (^C will work) */
1373 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1374 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1375 check_and_run_traps(0);
1376 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1377 i->eof_flag = (r < 0);
1378 if (i->eof_flag) { /* EOF/error detected */
1379 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1380 G.user_input_buf[1] = '\0';
1385 fputs(prompt_str, stdout);
1387 G.user_input_buf[0] = r = fgetc(i->file);
1388 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1389 //do we need check_and_run_traps(0)? (maybe only if stdin)
1390 } while (G.flag_SIGINT);
1391 i->eof_flag = (r == EOF);
1393 i->p = G.user_input_buf;
1396 #endif /* INTERACTIVE */
1398 /* This is the magic location that prints prompts
1399 * and gets data back from the user */
1400 static int file_get(struct in_str *i)
1404 /* If there is data waiting, eat it up */
1405 if (i->p && *i->p) {
1406 #if ENABLE_HUSH_INTERACTIVE
1410 if (i->eof_flag && !*i->p)
1412 /* note: ch is never NUL */
1414 /* need to double check i->file because we might be doing something
1415 * more complicated by now, like sourcing or substituting. */
1416 #if ENABLE_HUSH_INTERACTIVE
1417 if (G_interactive_fd && i->promptme && i->file == stdin) {
1420 } while (!*i->p); /* need non-empty line */
1421 i->promptmode = 1; /* PS2 */
1426 do ch = fgetc(i->file); while (ch == '\0');
1428 debug_printf("file_get: got '%c' %d\n", ch, ch);
1429 #if ENABLE_HUSH_INTERACTIVE
1436 /* All callers guarantee this routine will never
1437 * be used right after a newline, so prompting is not needed.
1439 static int file_peek(struct in_str *i)
1442 if (i->p && *i->p) {
1443 if (i->eof_flag && !i->p[1])
1446 /* note: ch is never NUL */
1448 do ch = fgetc(i->file); while (ch == '\0');
1449 i->eof_flag = (ch == EOF);
1450 i->peek_buf[0] = ch;
1451 i->peek_buf[1] = '\0';
1453 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1457 static void setup_file_in_str(struct in_str *i, FILE *f)
1459 i->peek = file_peek;
1461 #if ENABLE_HUSH_INTERACTIVE
1463 i->promptmode = 0; /* PS1 */
1469 static void setup_string_in_str(struct in_str *i, const char *s)
1471 i->peek = static_peek;
1472 i->get = static_get;
1473 #if ENABLE_HUSH_INTERACTIVE
1475 i->promptmode = 0; /* PS1 */
1485 #define B_CHUNK (32 * sizeof(char*))
1487 static void o_reset_to_empty_unquoted(o_string *o)
1495 static void o_free(o_string *o)
1498 memset(o, 0, sizeof(*o));
1501 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1506 static void o_grow_by(o_string *o, int len)
1508 if (o->length + len > o->maxlen) {
1509 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1510 o->data = xrealloc(o->data, 1 + o->maxlen);
1514 static void o_addchr(o_string *o, int ch)
1516 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1518 o->data[o->length] = ch;
1520 o->data[o->length] = '\0';
1523 static void o_addblock(o_string *o, const char *str, int len)
1526 memcpy(&o->data[o->length], str, len);
1528 o->data[o->length] = '\0';
1532 static void o_addstr(o_string *o, const char *str)
1534 o_addblock(o, str, strlen(str));
1536 static void nommu_addchr(o_string *o, int ch)
1542 #define nommu_addchr(o, str) ((void)0)
1545 static void o_addstr_with_NUL(o_string *o, const char *str)
1547 o_addblock(o, str, strlen(str) + 1);
1550 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1555 && (*str != '*' && *str != '?' && *str != '[')
1563 /* My analysis of quoting semantics tells me that state information
1564 * is associated with a destination, not a source.
1566 static void o_addqchr(o_string *o, int ch)
1569 char *found = strchr("*?[\\", ch);
1574 o->data[o->length] = '\\';
1577 o->data[o->length] = ch;
1579 o->data[o->length] = '\0';
1582 static void o_addQchr(o_string *o, int ch)
1585 if (o->o_escape && strchr("*?[\\", ch)) {
1587 o->data[o->length] = '\\';
1591 o->data[o->length] = ch;
1593 o->data[o->length] = '\0';
1596 static void o_addQstr(o_string *o, const char *str, int len)
1599 o_addblock(o, str, len);
1605 int ordinary_cnt = strcspn(str, "*?[\\");
1606 if (ordinary_cnt > len) /* paranoia */
1608 o_addblock(o, str, ordinary_cnt);
1609 if (ordinary_cnt == len)
1611 str += ordinary_cnt;
1612 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1616 if (ch) { /* it is necessarily one of "*?[\\" */
1618 o->data[o->length] = '\\';
1622 o->data[o->length] = ch;
1624 o->data[o->length] = '\0';
1628 /* A special kind of o_string for $VAR and `cmd` expansion.
1629 * It contains char* list[] at the beginning, which is grown in 16 element
1630 * increments. Actual string data starts at the next multiple of 16 * (char*).
1631 * list[i] contains an INDEX (int!) into this string data.
1632 * It means that if list[] needs to grow, data needs to be moved higher up
1633 * but list[i]'s need not be modified.
1634 * NB: remembering how many list[i]'s you have there is crucial.
1635 * o_finalize_list() operation post-processes this structure - calculates
1636 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1638 #if DEBUG_EXPAND || DEBUG_GLOB
1639 static void debug_print_list(const char *prefix, o_string *o, int n)
1641 char **list = (char**)o->data;
1642 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1644 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1645 prefix, list, n, string_start, o->length, o->maxlen);
1647 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1648 o->data + (int)list[i] + string_start,
1649 o->data + (int)list[i] + string_start);
1653 const char *p = o->data + (int)list[n - 1] + string_start;
1654 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1658 #define debug_print_list(prefix, o, n) ((void)0)
1661 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1662 * in list[n] so that it points past last stored byte so far.
1663 * It returns n+1. */
1664 static int o_save_ptr_helper(o_string *o, int n)
1666 char **list = (char**)o->data;
1670 if (!o->has_empty_slot) {
1671 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1672 string_len = o->length - string_start;
1673 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1674 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1675 /* list[n] points to string_start, make space for 16 more pointers */
1676 o->maxlen += 0x10 * sizeof(list[0]);
1677 o->data = xrealloc(o->data, o->maxlen + 1);
1678 list = (char**)o->data;
1679 memmove(list + n + 0x10, list + n, string_len);
1680 o->length += 0x10 * sizeof(list[0]);
1682 debug_printf_list("list[%d]=%d string_start=%d\n",
1683 n, string_len, string_start);
1686 /* We have empty slot at list[n], reuse without growth */
1687 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1688 string_len = o->length - string_start;
1689 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1690 n, string_len, string_start);
1691 o->has_empty_slot = 0;
1693 list[n] = (char*)(ptrdiff_t)string_len;
1697 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1698 static int o_get_last_ptr(o_string *o, int n)
1700 char **list = (char**)o->data;
1701 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1703 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1706 /* o_glob performs globbing on last list[], saving each result
1707 * as a new list[]. */
1708 static int o_glob(o_string *o, int n)
1714 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1716 return o_save_ptr_helper(o, n);
1717 pattern = o->data + o_get_last_ptr(o, n);
1718 debug_printf_glob("glob pattern '%s'\n", pattern);
1719 if (!glob_needed(pattern)) {
1721 o->length = unbackslash(pattern) - o->data;
1722 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1723 return o_save_ptr_helper(o, n);
1726 memset(&globdata, 0, sizeof(globdata));
1727 gr = glob(pattern, 0, NULL, &globdata);
1728 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1729 if (gr == GLOB_NOSPACE)
1730 bb_error_msg_and_die("out of memory during glob");
1731 if (gr == GLOB_NOMATCH) {
1732 globfree(&globdata);
1735 if (gr != 0) { /* GLOB_ABORTED ? */
1736 //TODO: testcase for bad glob pattern behavior
1737 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1739 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1740 char **argv = globdata.gl_pathv;
1741 o->length = pattern - o->data; /* "forget" pattern */
1743 o_addstr_with_NUL(o, *argv);
1744 n = o_save_ptr_helper(o, n);
1750 globfree(&globdata);
1752 debug_print_list("o_glob returning", o, n);
1756 /* If o->o_glob == 1, glob the string so far remembered.
1757 * Otherwise, just finish current list[] and start new */
1758 static int o_save_ptr(o_string *o, int n)
1760 if (o->o_glob) { /* if globbing is requested */
1761 /* If o->has_empty_slot, list[n] was already globbed
1762 * (if it was requested back then when it was filled)
1763 * so don't do that again! */
1764 if (!o->has_empty_slot)
1765 return o_glob(o, n); /* o_save_ptr_helper is inside */
1767 return o_save_ptr_helper(o, n);
1770 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1771 static char **o_finalize_list(o_string *o, int n)
1776 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1778 debug_print_list("finalized", o, n);
1779 debug_printf_expand("finalized n:%d\n", n);
1780 list = (char**)o->data;
1781 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1785 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1791 /* Expansion can recurse */
1792 #if ENABLE_HUSH_TICK
1793 static int process_command_subs(o_string *dest, const char *s);
1795 static char *expand_string_to_string(const char *str);
1797 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1798 parse_stream_dquoted(dest, input, dquote_end)
1800 static int parse_stream_dquoted(o_string *as_string,
1802 struct in_str *input,
1805 /* expand_strvec_to_strvec() takes a list of strings, expands
1806 * all variable references within and returns a pointer to
1807 * a list of expanded strings, possibly with larger number
1808 * of strings. (Think VAR="a b"; echo $VAR).
1809 * This new list is allocated as a single malloc block.
1810 * NULL-terminated list of char* pointers is at the beginning of it,
1811 * followed by strings themself.
1812 * Caller can deallocate entire list by single free(list). */
1814 /* Store given string, finalizing the word and starting new one whenever
1815 * we encounter IFS char(s). This is used for expanding variable values.
1816 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1817 static int expand_on_ifs(o_string *output, int n, const char *str)
1820 int word_len = strcspn(str, G.ifs);
1822 if (output->o_escape || !output->o_glob)
1823 o_addQstr(output, str, word_len);
1824 else /* protect backslashes against globbing up :) */
1825 o_addblock_duplicate_backslash(output, str, word_len);
1828 if (!*str) /* EOL - do not finalize word */
1830 o_addchr(output, '\0');
1831 debug_print_list("expand_on_ifs", output, n);
1832 n = o_save_ptr(output, n);
1833 str += strspn(str, G.ifs); /* skip ifs chars */
1835 debug_print_list("expand_on_ifs[1]", output, n);
1839 /* Helper to expand $((...)) and heredoc body. These act as if
1840 * they are in double quotes, with the exception that they are not :).
1841 * Just the rules are similar: "expand only $var and `cmd`"
1843 * Returns malloced string.
1844 * As an optimization, we return NULL if expansion is not needed.
1846 static char *expand_pseudo_dquoted(const char *str)
1849 struct in_str input;
1850 o_string dest = NULL_O_STRING;
1852 if (strchr(str, '$') == NULL
1853 #if ENABLE_HUSH_TICK
1854 && strchr(str, '`') == NULL
1860 /* We need to expand. Example:
1861 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1863 setup_string_in_str(&input, str);
1864 parse_stream_dquoted(NULL, &dest, &input, EOF);
1865 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1866 exp_str = expand_string_to_string(dest.data);
1867 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1868 o_free_unsafe(&dest);
1872 /* Expand all variable references in given string, adding words to list[]
1873 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1874 * to be filled). This routine is extremely tricky: has to deal with
1875 * variables/parameters with whitespace, $* and $@, and constructs like
1876 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1877 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1879 /* or_mask is either 0 (normal case) or 0x80
1880 * (expansion of right-hand side of assignment == 1-element expand.
1881 * It will also do no globbing, and thus we must not backslash-quote!) */
1883 char first_ch, ored_ch;
1891 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1892 debug_print_list("expand_vars_to_list", output, n);
1893 n = o_save_ptr(output, n);
1894 debug_print_list("expand_vars_to_list[0]", output, n);
1896 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1897 #if ENABLE_HUSH_TICK
1898 o_string subst_result = NULL_O_STRING;
1900 #if ENABLE_SH_MATH_SUPPORT
1901 char arith_buf[sizeof(arith_t)*3 + 2];
1903 o_addblock(output, arg, p - arg);
1904 debug_print_list("expand_vars_to_list[1]", output, n);
1906 p = strchr(p, SPECIAL_VAR_SYMBOL);
1908 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1909 /* "$@" is special. Even if quoted, it can still
1910 * expand to nothing (not even an empty string) */
1911 if ((first_ch & 0x7f) != '@')
1912 ored_ch |= first_ch;
1915 switch (first_ch & 0x7f) {
1916 /* Highest bit in first_ch indicates that var is double-quoted */
1918 val = utoa(G.root_pid);
1920 case '!': /* bg pid */
1921 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1923 case '?': /* exitcode */
1924 val = utoa(G.last_exitcode);
1926 case '#': /* argc */
1927 if (arg[1] != SPECIAL_VAR_SYMBOL)
1928 /* actually, it's a ${#var} */
1930 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1935 if (!G.global_argv[i])
1937 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1938 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1939 smallint sv = output->o_escape;
1940 /* unquoted var's contents should be globbed, so don't escape */
1941 output->o_escape = 0;
1942 while (G.global_argv[i]) {
1943 n = expand_on_ifs(output, n, G.global_argv[i]);
1944 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1945 if (G.global_argv[i++][0] && G.global_argv[i]) {
1946 /* this argv[] is not empty and not last:
1947 * put terminating NUL, start new word */
1948 o_addchr(output, '\0');
1949 debug_print_list("expand_vars_to_list[2]", output, n);
1950 n = o_save_ptr(output, n);
1951 debug_print_list("expand_vars_to_list[3]", output, n);
1954 output->o_escape = sv;
1956 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1957 * and in this case should treat it like '$*' - see 'else...' below */
1958 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1960 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1961 if (++i >= G.global_argc)
1963 o_addchr(output, '\0');
1964 debug_print_list("expand_vars_to_list[4]", output, n);
1965 n = o_save_ptr(output, n);
1967 } else { /* quoted $*: add as one word */
1969 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1970 if (!G.global_argv[++i])
1973 o_addchr(output, G.ifs[0]);
1977 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1978 /* "Empty variable", used to make "" etc to not disappear */
1982 #if ENABLE_HUSH_TICK
1983 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1986 //TODO: can we just stuff it into "output" directly?
1987 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1988 process_command_subs(&subst_result, arg);
1989 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1990 val = subst_result.data;
1993 #if ENABLE_SH_MATH_SUPPORT
1994 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1995 arith_eval_hooks_t hooks;
2000 arg++; /* skip '+' */
2001 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2002 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2004 exp_str = expand_pseudo_dquoted(arg);
2005 hooks.lookupvar = get_local_var_value;
2006 hooks.setvar = arith_set_local_var;
2007 hooks.endofname = endofname;
2008 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2012 const char *msg = "error in arithmetic";
2015 msg = "exponent less than 0";
2018 msg = "divide by 0";
2021 msg = "expression recursion loop detected";
2026 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2027 sprintf(arith_buf, arith_t_fmt, res);
2032 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2034 bool exp_len = false;
2035 bool exp_null = false;
2037 char exp_save = exp_save; /* for compiler */
2038 char exp_op = exp_op; /* for compiler */
2039 char *exp_word = exp_word; /* for compiler */
2043 arg[0] = first_ch & 0x7f;
2045 /* prepare for expansions */
2046 if (var[0] == '#') {
2047 /* handle length expansion ${#var} */
2051 /* maybe handle parameter expansion */
2052 exp_off = strcspn(var, ":-=+?%#");
2056 exp_save = var[exp_off];
2057 exp_null = exp_save == ':';
2058 exp_word = var + exp_off;
2061 exp_op = *exp_word++;
2062 var[exp_off] = '\0';
2066 /* lookup the variable in question */
2067 if (isdigit(var[0])) {
2068 /* handle_dollar() should have vetted var for us */
2070 if (i < G.global_argc)
2071 val = G.global_argv[i];
2072 /* else val remains NULL: $N with too big N */
2074 val = get_local_var_value(var);
2076 /* handle any expansions */
2078 debug_printf_expand("expand: length of '%s' = ", val);
2079 val = utoa(val ? strlen(val) : 0);
2080 debug_printf_expand("%s\n", val);
2081 } else if (exp_off) {
2082 if (exp_op == '%' || exp_op == '#') {
2084 /* we need to do a pattern match */
2087 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2088 if (exp_op == *exp_word) /* ## or %% */
2090 val = dyn_val = xstrdup(val);
2091 loc = scan(dyn_val, exp_word, zero);
2098 /* we need to do an expansion */
2099 int exp_test = (!val || (exp_null && !val[0]));
2101 exp_test = !exp_test;
2102 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2103 exp_null ? "true" : "false", exp_test);
2105 if (exp_op == '?') {
2106 //TODO: how interactive bash aborts expansion mid-command?
2107 /* ${var?[error_msg_if_unset]} */
2108 /* ${var:?[error_msg_if_unset_or_null]} */
2109 /* mimic bash message */
2110 die_if_script("%s: %s",
2112 exp_word[0] ? exp_word : "parameter null or not set"
2118 if (exp_op == '=') {
2119 /* ${var=[word]} or ${var:=[word]} */
2120 if (isdigit(var[0]) || var[0] == '#') {
2121 /* mimic bash message */
2122 die_if_script("$%s: cannot assign in this way", var);
2125 char *new_var = xasprintf("%s=%s", var, val);
2126 set_local_var(new_var, -1, 0);
2132 var[exp_off] = exp_save;
2136 #if ENABLE_HUSH_TICK
2139 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2140 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2142 /* unquoted var's contents should be globbed, so don't escape */
2143 smallint sv = output->o_escape;
2144 output->o_escape = 0;
2145 n = expand_on_ifs(output, n, val);
2147 output->o_escape = sv;
2149 } else { /* quoted $VAR, val will be appended below */
2150 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2153 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2155 o_addQstr(output, val, strlen(val));
2159 /* Do the check to avoid writing to a const string */
2160 if (*p != SPECIAL_VAR_SYMBOL)
2161 *p = SPECIAL_VAR_SYMBOL;
2163 #if ENABLE_HUSH_TICK
2164 o_free(&subst_result);
2167 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2170 debug_print_list("expand_vars_to_list[a]", output, n);
2171 /* this part is literal, and it was already pre-quoted
2172 * if needed (much earlier), do not use o_addQstr here! */
2173 o_addstr_with_NUL(output, arg);
2174 debug_print_list("expand_vars_to_list[b]", output, n);
2175 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2176 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2179 /* allow to reuse list[n] later without re-growth */
2180 output->has_empty_slot = 1;
2182 o_addchr(output, '\0');
2187 static char **expand_variables(char **argv, int or_mask)
2192 o_string output = NULL_O_STRING;
2194 if (or_mask & 0x100) {
2195 output.o_escape = 1; /* protect against globbing for "$var" */
2196 /* (unquoted $var will temporarily switch it off) */
2203 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2206 debug_print_list("expand_variables", &output, n);
2208 /* output.data (malloced in one block) gets returned in "list" */
2209 list = o_finalize_list(&output, n);
2210 debug_print_strings("expand_variables[1]", list);
2214 static char **expand_strvec_to_strvec(char **argv)
2216 return expand_variables(argv, 0x100);
2219 /* Used for expansion of right hand of assignments */
2220 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2222 static char *expand_string_to_string(const char *str)
2224 char *argv[2], **list;
2226 argv[0] = (char*)str;
2228 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2230 if (!list[0] || list[1])
2231 bb_error_msg_and_die("BUG in varexp2");
2232 /* actually, just move string 2*sizeof(char*) bytes back */
2233 overlapping_strcpy((char*)list, list[0]);
2234 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2238 /* Used for "eval" builtin */
2239 static char* expand_strvec_to_string(char **argv)
2243 list = expand_variables(argv, 0x80);
2244 /* Convert all NULs to spaces */
2249 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2250 bb_error_msg_and_die("BUG in varexp3");
2251 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2255 overlapping_strcpy((char*)list, list[0]);
2256 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2260 static char **expand_assignments(char **argv, int count)
2264 /* Expand assignments into one string each */
2265 for (i = 0; i < count; i++) {
2266 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2274 void re_execute_shell(const char *s, char *argv0, char **argv);
2276 #define clean_up_after_re_execute() ((void)0)
2278 static void reset_traps_to_defaults(void)
2286 for (sig = 0; sig < NSIG; sig++) {
2290 G.traps[sig] = NULL;
2291 /* There is no signal for 0 (EXIT) */
2294 /* there was a trap handler, we are removing it
2295 * (if sig has non-DFL handling,
2296 * we don't need to do anything) */
2297 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2299 sigdelset(&G.blocked_set, sig);
2303 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2308 static void re_execute_shell(const char *s, char *g_argv0, char **g_argv) NORETURN;
2309 static void re_execute_shell(const char *s, char *g_argv0, char **g_argv)
2311 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2312 char *heredoc_argv[4];
2313 struct variable *cur;
2317 if (!g_argv0) { /* heredoc */
2318 argv = heredoc_argv;
2319 argv[0] = (char *) G.argv0_for_re_execing;
2320 argv[1] = (char *) "-<";
2321 argv[2] = (char *) s;
2323 pp = &argv[3]; /* used as pointer to empty environment */
2327 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2328 , (unsigned) G.root_pid
2329 , (unsigned) G.last_bg_pid
2330 , (unsigned) G.last_exitcode
2331 USE_HUSH_LOOPS(, G.depth_of_loop)
2333 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2334 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2337 for (cur = G.top_var; cur; cur = cur->next) {
2338 if (!cur->flg_export || cur->flg_read_only)
2344 G.argv_from_re_execing = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2345 *pp++ = (char *) G.argv0_for_re_execing;
2347 for (cur = G.top_var; cur; cur = cur->next) {
2348 if (cur->varstr == hush_version_str)
2350 if (cur->flg_read_only) {
2351 *pp++ = (char *) "-R";
2352 *pp++ = cur->varstr;
2353 } else if (!cur->flg_export) {
2354 *pp++ = (char *) "-V";
2355 *pp++ = cur->varstr;
2358 //TODO: pass functions
2359 /* We can pass activated traps here. Say, -Tnn:trap_string
2361 * However, POSIX says that subshells reset signals with traps
2363 * I tested bash-3.2 and it not only does that with true subshells
2364 * of the form ( list ), but with any forked children shells.
2365 * I set trap "echo W" WINCH; and then tried:
2367 * { echo 1; sleep 20; echo 2; } &
2368 * while true; do echo 1; sleep 20; echo 2; break; done &
2369 * true | { echo 1; sleep 20; echo 2; } | cat
2371 * In all these cases sending SIGWINCH to the child shell
2372 * did not run the trap. If I add trap "echo V" WINCH;
2373 * _inside_ group (just before echo 1), it works.
2375 * I conclude it means we don't need to pass active traps here.
2376 * exec syscall below resets them to SIG_DFL for us.
2378 *pp++ = (char *) "-c";
2383 /* *pp = NULL; - is already there */
2387 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2388 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2389 execve(bb_busybox_exec_path, argv, pp);
2390 /* Fallback. Useful for init=/bin/hush usage etc */
2391 if (argv[0][0] == '/')
2392 execve(argv[0], argv, pp);
2393 xfunc_error_retval = 127;
2394 bb_error_msg_and_die("can't re-execute the shell");
2397 static void clean_up_after_re_execute(void)
2399 char **pp = G.argv_from_re_execing;
2401 /* Must match re_execute_shell's allocations (if any) */
2403 G.argv_from_re_execing = NULL;
2406 #endif /* !BB_MMU */
2409 static void setup_heredoc(struct redir_struct *redir)
2411 struct fd_pair pair;
2414 /* the _body_ of heredoc (misleading field name) */
2415 const char *heredoc = redir->rd_filename;
2419 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2420 expanded = expand_pseudo_dquoted(heredoc);
2424 len = strlen(heredoc);
2426 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2428 xmove_fd(pair.rd, redir->rd_fd);
2430 /* Try writing without forking. Newer kernels have
2431 * dynamically growing pipes. Must use non-blocking write! */
2434 written = write(pair.wr, heredoc, len);
2445 ndelay_off(pair.wr);
2447 /* Okay, pipe buffer was not big enough */
2448 /* Note: we must not create a stray child (bastard? :)
2449 * for the unsuspecting parent process. Child creates a grandchild
2450 * and exits before parent execs the process which consumes heredoc
2451 * (that exec happens after we return from this function) */
2454 bb_perror_msg_and_die("vfork");
2457 pid = BB_MMU ? fork() : vfork();
2459 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2463 close(redir->rd_fd); /* read side of the pipe */
2465 full_write(pair.wr, heredoc, len); /* may loop or block */
2468 /* Delegate blocking writes to another process */
2469 disable_restore_tty_pgrp_on_exit();
2470 xmove_fd(pair.wr, STDOUT_FILENO);
2471 re_execute_shell(heredoc, NULL, NULL);
2475 enable_restore_tty_pgrp_on_exit();
2476 clean_up_after_re_execute();
2479 wait(NULL); /* wait till child has died */
2482 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2483 * and stderr if they are redirected. */
2484 static int setup_redirects(struct command *prog, int squirrel[])
2487 struct redir_struct *redir;
2489 for (redir = prog->redirects; redir; redir = redir->next) {
2490 if (redir->rd_type == REDIRECT_HEREDOC2) {
2491 /* rd_fd<<HERE case */
2492 if (squirrel && redir->rd_fd < 3) {
2493 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2495 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2497 debug_printf_parse("set heredoc '%s'\n",
2498 redir->rd_filename);
2499 setup_heredoc(redir);
2503 if (redir->rd_dup == REDIRFD_TO_FILE) {
2504 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2506 if (redir->rd_filename == NULL) {
2507 /* Something went wrong in the parse.
2508 * Pretend it didn't happen */
2509 bb_error_msg("bug in redirect parse");
2512 mode = redir_table[redir->rd_type].mode;
2513 p = expand_string_to_string(redir->rd_filename);
2514 openfd = open_or_warn(p, mode);
2517 /* this could get lost if stderr has been redirected, but
2518 * bash and ash both lose it as well (though zsh doesn't!) */
2519 //what the above comment tries to say?
2523 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2524 openfd = redir->rd_dup;
2527 if (openfd != redir->rd_fd) {
2528 if (squirrel && redir->rd_fd < 3) {
2529 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2531 if (openfd == REDIRFD_CLOSE) {
2532 /* "n>-" means "close me" */
2533 close(redir->rd_fd);
2535 xdup2(openfd, redir->rd_fd);
2536 if (redir->rd_dup == REDIRFD_TO_FILE)
2544 static void restore_redirects(int squirrel[])
2547 for (i = 0; i < 3; i++) {
2550 /* We simply die on error */
2558 #define free_pipe_list(head, indent) free_pipe_list(head)
2559 #define free_pipe(pi, indent) free_pipe(pi)
2561 static void free_pipe_list(struct pipe *head, int indent);
2563 /* Return code is the exit status of the pipe */
2564 static void free_pipe(struct pipe *pi, int indent)
2567 struct command *command;
2568 struct redir_struct *r, *rnext;
2571 if (pi->stopped_cmds > 0) /* why? */
2573 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2574 for (i = 0; i < pi->num_cmds; i++) {
2575 command = &pi->cmds[i];
2576 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2577 if (command->argv) {
2578 for (a = 0, p = command->argv; *p; a++, p++) {
2579 debug_printf_clean("%s argv[%d] = %s\n",
2580 indenter(indent), a, *p);
2582 free_strings(command->argv);
2583 command->argv = NULL;
2585 /* not "else if": on syntax error, we may have both! */
2586 if (command->group) {
2587 debug_printf_clean("%s begin group (grp_type:%d)\n",
2588 indenter(indent), command->grp_type);
2589 free_pipe_list(command->group, indent+3);
2590 debug_printf_clean("%s end group\n", indenter(indent));
2591 command->group = NULL;
2593 /* else is crucial here.
2594 * If group != NULL, child_func is meaningless */
2595 #if ENABLE_HUSH_FUNCTIONS
2596 else if (command->child_func) {
2597 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2598 command->child_func->parent_cmd = NULL;
2602 free(command->group_as_string);
2603 command->group_as_string = NULL;
2605 for (r = command->redirects; r; r = rnext) {
2606 debug_printf_clean("%s redirect %d%s", indenter(indent),
2607 r->fd, redir_table[r->rd_type].descrip);
2608 /* guard against the case >$FOO, where foo is unset or blank */
2609 if (r->rd_filename) {
2610 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2611 free(r->rd_filename);
2612 r->rd_filename = NULL;
2614 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2618 command->redirects = NULL;
2620 free(pi->cmds); /* children are an array, they get freed all at once */
2628 static void free_pipe_list(struct pipe *head, int indent)
2630 struct pipe *pi, *next;
2632 for (pi = head; pi; pi = next) {
2634 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2636 free_pipe(pi, indent);
2637 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2639 /*pi->next = NULL;*/
2645 static int run_list(struct pipe *pi);
2647 static const struct built_in_command* find_builtin(const char *name)
2649 const struct built_in_command *x;
2650 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2651 if (strcmp(name, x->cmd) != 0)
2653 debug_printf_exec("found builtin '%s'\n", name);
2659 #if ENABLE_HUSH_FUNCTIONS
2660 static const struct function *find_function(const char *name)
2662 const struct function *funcp = G.top_func;
2664 if (strcmp(name, funcp->name) == 0) {
2667 funcp = funcp->next;
2669 debug_printf_exec("found function '%s'\n", name);
2673 static void exec_function(const struct function *funcp, char **argv) NORETURN;
2674 static void exec_function(const struct function *funcp, char **argv)
2679 argv[0] = G.global_argv[0];
2680 G.global_argv = argv;
2684 n = run_list(funcp->body);
2688 re_execute_shell(funcp->body_as_string, G.global_argv[0], argv + 1);
2692 static int run_function(const struct function *funcp, char **argv)
2697 smallint sv_g_malloced;
2702 sv_g_malloced = G.global_args_malloced;
2703 sv_g_argc = G.global_argc;
2704 sv_g_argv = G.global_argv;
2711 argv[0] = G.global_argv[0]; /* retain $0 */
2712 G.global_args_malloced = 0;
2714 G.global_argv = argv;
2716 n = run_list(funcp->body);
2718 if (G.global_args_malloced) {
2719 /* function ran "set -- arg1 arg2 ..." */
2723 free(G.global_argv);
2727 G.global_args_malloced = sv_g_malloced;
2728 G.global_argc = sv_g_argc;
2729 G.global_argv = sv_g_argv;
2737 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2738 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2739 #define pseudo_exec(nommu_save, command, argv_expanded) \
2740 pseudo_exec(command, argv_expanded)
2743 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2745 * XXX no exit() here. If you don't exec, use _exit instead.
2746 * The at_exit handlers apparently confuse the calling process,
2747 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2748 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2749 char **argv, int assignment_cnt,
2750 char **argv_expanded) NORETURN;
2751 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2752 char **argv, int assignment_cnt,
2753 char **argv_expanded)
2757 /* Case when we are here: ... | var=val | ... */
2758 if (!argv[assignment_cnt])
2759 _exit(EXIT_SUCCESS);
2761 new_env = expand_assignments(argv, assignment_cnt);
2763 putenv_all(new_env);
2764 free(new_env); /* optional */
2766 nommu_save->new_env = new_env;
2767 nommu_save->old_env = putenv_all_and_save_old(new_env);
2769 if (argv_expanded) {
2770 argv = argv_expanded;
2772 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2774 nommu_save->argv = argv;
2778 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2779 if (strchr(argv[0], '/') != NULL)
2783 /* On NOMMU, we must never block!
2784 * Example: { sleep 99999 | read line } & echo Ok
2785 * read builtin will block on read syscall, leaving parent blocked
2786 * in vfork. Therefore we can't do this:
2789 /* Check if the command matches any of the builtins.
2790 * Depending on context, this might be redundant. But it's
2791 * easier to waste a few CPU cycles than it is to figure out
2792 * if this is one of those cases.
2796 const struct built_in_command *x = find_builtin(argv[0]);
2798 rcode = x->function(argv);
2804 #if ENABLE_HUSH_FUNCTIONS
2805 /* Check if the command matches any functions */
2807 const struct function *funcp = find_function(argv[0]);
2809 exec_function(funcp, argv);
2814 #if ENABLE_FEATURE_SH_STANDALONE
2815 /* Check if the command matches any busybox applets */
2817 int a = find_applet_by_name(argv[0]);
2819 # if BB_MMU /* see above why on NOMMU it is not allowed */
2820 if (APPLET_IS_NOEXEC(a)) {
2821 debug_printf_exec("running applet '%s'\n", argv[0]);
2822 run_applet_no_and_exit(a, argv);
2825 /* Re-exec ourselves */
2826 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2827 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2828 execv(bb_busybox_exec_path, argv);
2829 /* If they called chroot or otherwise made the binary no longer
2830 * executable, fall through */
2835 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2838 debug_printf_exec("execing '%s'\n", argv[0]);
2839 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2840 execvp(argv[0], argv);
2841 bb_perror_msg("can't exec '%s'", argv[0]);
2842 _exit(EXIT_FAILURE);
2845 /* Called after [v]fork() in run_pipe
2847 static void pseudo_exec(nommu_save_t *nommu_save,
2848 struct command *command,
2849 char **argv_expanded) NORETURN;
2850 static void pseudo_exec(nommu_save_t *nommu_save,
2851 struct command *command,
2852 char **argv_expanded)
2854 if (command->argv) {
2855 pseudo_exec_argv(nommu_save, command->argv,
2856 command->assignment_cnt, argv_expanded);
2859 if (command->group) {
2860 /* Cases when we are here:
2863 * ... | ( list ) | ...
2864 * ... | { list } | ...
2868 debug_printf_exec("pseudo_exec: run_list\n");
2869 reset_traps_to_defaults();
2870 rcode = run_list(command->group);
2871 /* OK to leak memory by not calling free_pipe_list,
2872 * since this process is about to exit */
2875 re_execute_shell(command->group_as_string,
2881 /* Case when we are here: ... | >file */
2882 debug_printf_exec("pseudo_exec'ed null command\n");
2883 _exit(EXIT_SUCCESS);
2887 static const char *get_cmdtext(struct pipe *pi)
2893 /* This is subtle. ->cmdtext is created only on first backgrounding.
2894 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2895 * On subsequent bg argv is trashed, but we won't use it */
2898 argv = pi->cmds[0].argv;
2899 if (!argv || !argv[0]) {
2900 pi->cmdtext = xzalloc(1);
2905 do len += strlen(*argv) + 1; while (*++argv);
2906 pi->cmdtext = p = xmalloc(len);
2907 argv = pi->cmds[0].argv;
2909 len = strlen(*argv);
2910 memcpy(p, *argv, len);
2918 static void insert_bg_job(struct pipe *pi)
2920 struct pipe *thejob;
2923 /* Linear search for the ID of the job to use */
2925 for (thejob = G.job_list; thejob; thejob = thejob->next)
2926 if (thejob->jobid >= pi->jobid)
2927 pi->jobid = thejob->jobid + 1;
2929 /* Add thejob to the list of running jobs */
2931 thejob = G.job_list = xmalloc(sizeof(*thejob));
2933 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2935 thejob->next = xmalloc(sizeof(*thejob));
2936 thejob = thejob->next;
2939 /* Physically copy the struct job */
2940 memcpy(thejob, pi, sizeof(struct pipe));
2941 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2942 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2943 for (i = 0; i < pi->num_cmds; i++) {
2944 // TODO: do we really need to have so many fields which are just dead weight
2945 // at execution stage?
2946 thejob->cmds[i].pid = pi->cmds[i].pid;
2947 /* all other fields are not used and stay zero */
2949 thejob->next = NULL;
2950 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2952 /* We don't wait for background thejobs to return -- append it
2953 to the list of backgrounded thejobs and leave it alone */
2954 if (G_interactive_fd)
2955 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2956 G.last_bg_pid = thejob->cmds[0].pid;
2957 G.last_jobid = thejob->jobid;
2960 static void remove_bg_job(struct pipe *pi)
2962 struct pipe *prev_pipe;
2964 if (pi == G.job_list) {
2965 G.job_list = pi->next;
2967 prev_pipe = G.job_list;
2968 while (prev_pipe->next != pi)
2969 prev_pipe = prev_pipe->next;
2970 prev_pipe->next = pi->next;
2973 G.last_jobid = G.job_list->jobid;
2978 /* Remove a backgrounded job */
2979 static void delete_finished_bg_job(struct pipe *pi)
2982 pi->stopped_cmds = 0;
2988 /* Check to see if any processes have exited -- if they
2989 * have, figure out why and see if a job has completed */
2990 static int checkjobs(struct pipe* fg_pipe)
3000 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3003 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3004 // /* avoid doing syscall, nothing there anyway */
3007 attributes = WUNTRACED;
3008 if (fg_pipe == NULL)
3009 attributes |= WNOHANG;
3011 /* Do we do this right?
3012 * bash-3.00# sleep 20 | false
3014 * [3]+ Stopped sleep 20 | false
3015 * bash-3.00# echo $?
3016 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3019 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
3020 //are stopped. Testcase: "cat | cat" in a script (not on command line)
3021 // + killall -STOP cat
3028 // i = G.count_SIGCHLD;
3029 childpid = waitpid(-1, &status, attributes);
3030 if (childpid <= 0) {
3031 if (childpid && errno != ECHILD)
3032 bb_perror_msg("waitpid");
3033 // else /* Until next SIGCHLD, waitpid's are useless */
3034 // G.handled_SIGCHLD = i;
3037 dead = WIFEXITED(status) || WIFSIGNALED(status);
3040 if (WIFSTOPPED(status))
3041 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3042 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3043 if (WIFSIGNALED(status))
3044 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3045 childpid, WTERMSIG(status), WEXITSTATUS(status));
3046 if (WIFEXITED(status))
3047 debug_printf_jobs("pid %d exited, exitcode %d\n",
3048 childpid, WEXITSTATUS(status));
3050 /* Were we asked to wait for fg pipe? */
3052 for (i = 0; i < fg_pipe->num_cmds; i++) {
3053 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3054 if (fg_pipe->cmds[i].pid != childpid)
3056 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
3058 fg_pipe->cmds[i].pid = 0;
3059 fg_pipe->alive_cmds--;
3060 if (i == fg_pipe->num_cmds - 1) {
3061 /* last process gives overall exitstatus */
3062 rcode = WEXITSTATUS(status);
3063 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3066 fg_pipe->cmds[i].is_stopped = 1;
3067 fg_pipe->stopped_cmds++;
3069 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3070 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3071 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3072 /* All processes in fg pipe have exited/stopped */
3074 if (fg_pipe->alive_cmds)
3075 insert_bg_job(fg_pipe);
3079 /* There are still running processes in the fg pipe */
3080 goto wait_more; /* do waitpid again */
3082 /* it wasnt fg_pipe, look for process in bg pipes */
3086 /* We asked to wait for bg or orphaned children */
3087 /* No need to remember exitcode in this case */
3088 for (pi = G.job_list; pi; pi = pi->next) {
3089 for (i = 0; i < pi->num_cmds; i++) {
3090 if (pi->cmds[i].pid == childpid)
3091 goto found_pi_and_prognum;
3094 /* Happens when shell is used as init process (init=/bin/sh) */
3095 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3096 continue; /* do waitpid again */
3098 found_pi_and_prognum:
3101 pi->cmds[i].pid = 0;
3103 if (!pi->alive_cmds) {
3104 if (G_interactive_fd)
3105 printf(JOB_STATUS_FORMAT, pi->jobid,
3106 "Done", pi->cmdtext);
3107 delete_finished_bg_job(pi);
3111 pi->cmds[i].is_stopped = 1;
3115 } /* while (waitpid succeeds)... */
3121 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3124 int rcode = checkjobs(fg_pipe);
3125 /* Job finished, move the shell to the foreground */
3126 p = getpgid(0); /* pgid of our process */
3127 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3128 tcsetpgrp(G_interactive_fd, p);
3133 /* Start all the jobs, but don't wait for anything to finish.
3136 * Return code is normally -1, when the caller has to wait for children
3137 * to finish to determine the exit status of the pipe. If the pipe
3138 * is a simple builtin command, however, the action is done by the
3139 * time run_pipe returns, and the exit code is provided as the
3142 * Returns -1 only if started some children. IOW: we have to
3143 * mask out retvals of builtins etc with 0xff!
3145 * The only case when we do not need to [v]fork is when the pipe
3146 * is single, non-backgrounded, non-subshell command. Examples:
3147 * cmd ; ... { list } ; ...
3148 * cmd && ... { list } && ...
3149 * cmd || ... { list } || ...
3150 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3151 * or (if SH_STANDALONE) an applet, and we can run the { list }
3152 * with run_list(). If it isn't one of these, we fork and exec cmd.
3154 * Cases when we must fork:
3155 * non-single: cmd | cmd
3156 * backgrounded: cmd & { list } &
3157 * subshell: ( list ) [&]
3159 static int run_pipe(struct pipe *pi)
3161 static const char *const null_ptr = NULL;
3164 int pipefds[2]; /* pipefds[0] is for reading */
3165 struct command *command;
3166 char **argv_expanded;
3169 /* it is not always needed, but we aim to smaller code */
3170 int squirrel[] = { -1, -1, -1 };
3173 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3175 USE_HUSH_JOB(pi->pgrp = -1;)
3176 pi->stopped_cmds = 0;
3177 command = &(pi->cmds[0]);
3178 argv_expanded = NULL;
3180 if (pi->num_cmds != 1
3181 || pi->followup == PIPE_BG
3182 || command->grp_type == GRP_SUBSHELL
3189 debug_printf_exec(": group:%p argv:'%s'\n",
3190 command->group, command->argv ? command->argv[0] : "NONE");
3192 if (command->group) {
3193 #if ENABLE_HUSH_FUNCTIONS
3194 if (command->grp_type == GRP_FUNCTION) {
3195 /* "executing" func () { list } */
3196 struct function *funcp;
3197 struct function **funcpp = &G.top_func;
3199 while ((funcp = *funcpp) != NULL) {
3200 if (strcmp(funcp->name, command->argv[0]) == 0) {
3201 struct command *cmd = funcp->parent_cmd;
3203 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3205 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3207 free_pipe_list(funcp->body, /* indent: */ 0);
3209 free(funcp->body_as_string);
3212 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3213 cmd->argv[0] = funcp->name;
3214 cmd->group = funcp->body;
3216 cmd->group_as_string = funcp->body_as_string;
3221 funcpp = &funcp->next;
3223 debug_printf_exec("remembering new function '%s'\n", command->argv[0]);
3224 funcp = *funcpp = xzalloc(sizeof(*funcp));
3225 /*funcp->next = NULL;*/
3227 funcp->name = command->argv[0];
3228 funcp->body = command->group;
3230 funcp->body_as_string = command->group_as_string;
3231 command->group_as_string = NULL;
3233 command->group = NULL;
3234 command->argv[0] = NULL;
3235 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3236 funcp->parent_cmd = command;
3237 command->child_func = funcp;
3239 return EXIT_SUCCESS;
3243 debug_printf("non-subshell group\n");
3244 rcode = 1; /* exitcode if redir failed */
3245 if (setup_redirects(command, squirrel) == 0) {
3246 debug_printf_exec(": run_list\n");
3247 rcode = run_list(command->group) & 0xff;
3248 debug_printf_exec("run_pipe return %d\n", rcode);
3250 restore_redirects(squirrel);
3251 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3255 argv = command->argv ? command->argv : (char **) &null_ptr;
3257 const struct built_in_command *x;
3258 #if ENABLE_HUSH_FUNCTIONS
3259 const struct function *funcp;
3263 char **new_env = NULL;
3264 char **old_env = NULL;
3266 if (argv[command->assignment_cnt] == NULL) {
3267 /* Assignments, but no command */
3268 /* Ensure redirects take effect. Try "a=t >file" */
3269 rcode = setup_redirects(command, squirrel);
3270 restore_redirects(squirrel);
3271 /* Set shell variables */
3273 p = expand_string_to_string(*argv);
3274 debug_printf_exec("set shell var:'%s'->'%s'\n",
3276 set_local_var(p, 0, 0);
3279 /* Do we need to flag set_local_var() errors?
3280 * "assignment to readonly var" and "putenv error"
3282 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3286 /* Expand the rest into (possibly) many strings each */
3287 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3289 x = find_builtin(argv_expanded[0]);
3290 #if ENABLE_HUSH_FUNCTIONS
3293 funcp = find_function(argv_expanded[0]);
3297 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3298 debug_printf("exec with redirects only\n");
3299 rcode = setup_redirects(command, NULL);
3300 goto clean_up_and_ret1;
3303 /* XXX setup_redirects acts on file descriptors, not FILEs.
3304 * This is perfect for work that comes after exec().
3305 * Is it really safe for inline use? Experimentally,
3306 * things seem to work with glibc. */
3307 rcode = setup_redirects(command, squirrel);
3309 new_env = expand_assignments(argv, command->assignment_cnt);
3310 old_env = putenv_all_and_save_old(new_env);
3312 debug_printf_exec(": builtin '%s' '%s'...\n",
3313 x->cmd, argv_expanded[1]);
3314 rcode = x->function(argv_expanded) & 0xff;
3316 #if ENABLE_HUSH_FUNCTIONS
3318 debug_printf_exec(": function '%s' '%s'...\n",
3319 funcp->name, argv_expanded[1]);
3320 rcode = run_function(funcp, argv_expanded) & 0xff;
3324 #if ENABLE_FEATURE_SH_STANDALONE
3327 restore_redirects(squirrel);
3328 free_strings_and_unsetenv(new_env, 1);
3329 putenv_all(old_env);
3330 /* Free the pointers, but the strings themselves
3331 * are in environ now, don't use free_strings! */
3334 free(argv_expanded);
3335 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3336 debug_printf_exec("run_pipe return %d\n", rcode);
3340 #if ENABLE_FEATURE_SH_STANDALONE
3341 i = find_applet_by_name(argv_expanded[0]);
3342 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3343 rcode = setup_redirects(command, squirrel);
3345 save_nofork_data(&G.nofork_save);
3346 new_env = expand_assignments(argv, command->assignment_cnt);
3347 old_env = putenv_all_and_save_old(new_env);
3348 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3349 argv_expanded[0], argv_expanded[1]);
3350 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3352 goto clean_up_and_ret;
3355 /* It is neither builtin nor applet. We must fork. */
3359 /* NB: argv_expanded may already be created, and that
3360 * might include `cmd` runs! Do not rerun it! We *must*
3361 * use argv_expanded if it's non-NULL */
3363 /* Going to fork a child per each pipe member */
3367 for (i = 0; i < pi->num_cmds; i++) {
3369 volatile nommu_save_t nommu_save;
3370 nommu_save.new_env = NULL;
3371 nommu_save.old_env = NULL;
3372 nommu_save.argv = NULL;
3374 command = &(pi->cmds[i]);
3375 if (command->argv) {
3376 debug_printf_exec(": pipe member '%s' '%s'...\n",
3377 command->argv[0], command->argv[1]);
3379 debug_printf_exec(": pipe member with no argv\n");
3382 /* pipes are inserted between pairs of commands */
3385 if ((i + 1) < pi->num_cmds)
3388 command->pid = BB_MMU ? fork() : vfork();
3389 if (!command->pid) { /* child */
3391 disable_restore_tty_pgrp_on_exit();
3393 /* Every child adds itself to new process group
3394 * with pgid == pid_of_first_child_in_pipe */
3395 if (G.run_list_level == 1 && G_interactive_fd) {
3398 if (pgrp < 0) /* true for 1st process only */
3400 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3401 /* We do it in *every* child, not just first,
3403 tcsetpgrp(G_interactive_fd, pgrp);
3407 xmove_fd(nextin, 0);
3408 xmove_fd(pipefds[1], 1); /* write end */
3410 close(pipefds[0]); /* read end */
3411 /* Like bash, explicit redirects override pipes,
3412 * and the pipe fd is available for dup'ing. */
3413 if (setup_redirects(command, NULL))
3416 /* Restore default handlers just prior to exec */
3417 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3419 /* Stores to nommu_save list of env vars putenv'ed
3420 * (NOMMU, on MMU we don't need that) */
3421 /* cast away volatility... */
3422 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3423 /* pseudo_exec() does not return */
3426 /* parent or error */
3427 enable_restore_tty_pgrp_on_exit();
3429 /* Clean up after vforked child */
3430 clean_up_after_re_execute();
3431 free(nommu_save.argv);
3432 free_strings_and_unsetenv(nommu_save.new_env, 1);
3433 putenv_all(nommu_save.old_env);
3434 /* Free the pointers, but the strings themselves
3435 * are in environ now, don't use free_strings! */
3436 free(nommu_save.old_env);
3438 free(argv_expanded);
3439 argv_expanded = NULL;
3440 if (command->pid < 0) { /* [v]fork failed */
3441 /* Clearly indicate, was it fork or vfork */
3442 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3446 /* Second and next children need to know pid of first one */
3448 pi->pgrp = command->pid;
3454 if ((i + 1) < pi->num_cmds)
3455 close(pipefds[1]); /* write end */
3456 /* Pass read (output) pipe end to next iteration */
3457 nextin = pipefds[0];
3460 if (!pi->alive_cmds) {
3461 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3465 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3469 #ifndef debug_print_tree
3470 static void debug_print_tree(struct pipe *pi, int lvl)
3472 static const char *const PIPE[] = {
3478 static const char *RES[] = {
3479 [RES_NONE ] = "NONE" ,
3482 [RES_THEN ] = "THEN" ,
3483 [RES_ELIF ] = "ELIF" ,
3484 [RES_ELSE ] = "ELSE" ,
3487 #if ENABLE_HUSH_LOOPS
3488 [RES_FOR ] = "FOR" ,
3489 [RES_WHILE] = "WHILE",
3490 [RES_UNTIL] = "UNTIL",
3492 [RES_DONE ] = "DONE" ,
3494 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3497 #if ENABLE_HUSH_CASE
3498 [RES_CASE ] = "CASE" ,
3499 [RES_MATCH] = "MATCH",
3500 [RES_CASEI] = "CASEI",
3501 [RES_ESAC ] = "ESAC" ,
3503 [RES_XXXX ] = "XXXX" ,
3504 [RES_SNTX ] = "SNTX" ,
3506 static const char *const GRPTYPE[] = {
3509 #if ENABLE_HUSH_FUNCTIONS
3518 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3519 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3521 while (prn < pi->num_cmds) {
3522 struct command *command = &pi->cmds[prn];
3523 char **argv = command->argv;
3525 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3527 command->assignment_cnt);
3528 if (command->group) {
3529 fprintf(stderr, " group %s: (argv=%p)\n",
3530 GRPTYPE[command->grp_type],
3532 debug_print_tree(command->group, lvl+1);
3536 if (argv) while (*argv) {
3537 fprintf(stderr, " '%s'", *argv);
3540 fprintf(stderr, "\n");
3549 /* NB: called by pseudo_exec, and therefore must not modify any
3550 * global data until exec/_exit (we can be a child after vfork!) */
3551 static int run_list(struct pipe *pi)
3553 #if ENABLE_HUSH_CASE
3554 char *case_word = NULL;
3556 #if ENABLE_HUSH_LOOPS
3557 struct pipe *loop_top = NULL;
3558 char *for_varname = NULL;
3559 char **for_lcur = NULL;
3560 char **for_list = NULL;
3562 smallint last_followup;
3564 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3565 smalluint cond_code = 0;
3567 enum { cond_code = 0 };
3570 smallint rword; /* enum reserved_style */
3571 smallint last_rword; /* ditto */
3574 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3576 #if ENABLE_HUSH_LOOPS
3577 /* Check syntax for "for" */
3578 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3579 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3581 /* current word is FOR or IN (BOLD in comments below) */
3582 if (cpipe->next == NULL) {
3583 syntax_error("malformed for");
3584 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3587 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3588 if (cpipe->next->res_word == RES_DO)
3590 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3591 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3592 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3594 syntax_error("malformed for");
3595 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3601 /* Past this point, all code paths should jump to ret: label
3602 * in order to return, no direct "return" statements please.
3603 * This helps to ensure that no memory is leaked. */
3605 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3608 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3609 * We are saving state before entering outermost list ("while...done")
3610 * so that ctrl-Z will correctly background _entire_ outermost list,
3611 * not just a part of it (like "sleep 1 | exit 2") */
3612 if (++G.run_list_level == 1 && G_interactive_fd) {
3613 if (sigsetjmp(G.toplevel_jb, 1)) {
3614 /* ctrl-Z forked and we are parent; or ctrl-C.
3615 * Sighandler has longjmped us here */
3616 signal(SIGINT, SIG_IGN);
3617 signal(SIGTSTP, SIG_IGN);
3618 /* Restore level (we can be coming from deep inside
3620 G.run_list_level = 1;
3621 #if ENABLE_FEATURE_SH_STANDALONE
3622 if (G.nofork_save.saved) { /* if save area is valid */
3623 debug_printf_jobs("exiting nofork early\n");
3624 restore_nofork_data(&G.nofork_save);
3627 //// if (G.ctrl_z_flag) {
3628 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3629 //// * Remember this child as background job */
3630 //// insert_bg_job(pi);
3632 /* ctrl-C. We just stop doing whatever we were doing */
3635 USE_HUSH_LOOPS(loop_top = NULL;)
3636 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3640 //// /* ctrl-Z handler will store pid etc in pi */
3641 //// G.toplevel_list = pi;
3642 //// G.ctrl_z_flag = 0;
3643 #if ENABLE_FEATURE_SH_STANDALONE
3644 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3646 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3647 //// signal(SIGINT, handler_ctrl_c);
3653 last_rword = RES_XXXX;
3655 last_followup = PIPE_SEQ;
3656 rcode = G.last_exitcode;
3658 /* Go through list of pipes, (maybe) executing them. */
3659 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3663 IF_HAS_KEYWORDS(rword = pi->res_word;)
3664 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3665 rword, cond_code, last_rword);
3666 #if ENABLE_HUSH_LOOPS
3667 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3668 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3670 /* start of a loop: remember where loop starts */
3675 /* Still in the same "if...", "then..." or "do..." branch? */
3676 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3677 if ((rcode == 0 && last_followup == PIPE_OR)
3678 || (rcode != 0 && last_followup == PIPE_AND)
3680 /* It is "<true> || CMD" or "<false> && CMD"
3681 * and we should not execute CMD */
3682 debug_printf_exec("skipped cmd because of || or &&\n");
3683 last_followup = pi->followup;
3687 last_followup = pi->followup;
3688 IF_HAS_KEYWORDS(last_rword = rword;)
3691 if (rword == RES_THEN) {
3692 /* if false; then ... fi has exitcode 0! */
3693 G.last_exitcode = rcode = EXIT_SUCCESS;
3694 /* "if <false> THEN cmd": skip cmd */
3698 if (rword == RES_ELSE || rword == RES_ELIF) {
3699 /* "if <true> then ... ELSE/ELIF cmd":
3700 * skip cmd and all following ones */
3705 #if ENABLE_HUSH_LOOPS
3706 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3708 /* first loop through for */
3710 static const char encoded_dollar_at[] ALIGN1 = {
3711 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3712 }; /* encoded representation of "$@" */
3713 static const char *const encoded_dollar_at_argv[] = {
3714 encoded_dollar_at, NULL
3715 }; /* argv list with one element: "$@" */
3718 vals = (char**)encoded_dollar_at_argv;
3719 if (pi->next->res_word == RES_IN) {
3720 /* if no variable values after "in" we skip "for" */
3721 if (!pi->next->cmds[0].argv) {
3722 G.last_exitcode = rcode = EXIT_SUCCESS;
3723 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3726 vals = pi->next->cmds[0].argv;
3727 } /* else: "for var; do..." -> assume "$@" list */
3728 /* create list of variable values */
3729 debug_print_strings("for_list made from", vals);
3730 for_list = expand_strvec_to_strvec(vals);
3731 for_lcur = for_list;
3732 debug_print_strings("for_list", for_list);
3733 for_varname = pi->cmds[0].argv[0];
3734 pi->cmds[0].argv[0] = NULL;
3736 free(pi->cmds[0].argv[0]);
3738 /* "for" loop is over, clean up */
3742 pi->cmds[0].argv[0] = for_varname;
3745 /* Insert next value from for_lcur */
3746 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3747 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3748 pi->cmds[0].assignment_cnt = 1;
3750 if (rword == RES_IN) {
3751 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3753 if (rword == RES_DONE) {
3754 continue; /* "done" has no cmds too */
3757 #if ENABLE_HUSH_CASE
3758 if (rword == RES_CASE) {
3759 case_word = expand_strvec_to_string(pi->cmds->argv);
3762 if (rword == RES_MATCH) {
3765 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3767 /* all prev words didn't match, does this one match? */
3768 argv = pi->cmds->argv;
3770 char *pattern = expand_string_to_string(*argv);
3771 /* TODO: which FNM_xxx flags to use? */
3772 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3774 if (cond_code == 0) { /* match! we will execute this branch */
3775 free(case_word); /* make future "word)" stop */
3783 if (rword == RES_CASEI) { /* inside of a case branch */
3785 continue; /* not matched yet, skip this pipe */
3788 /* Just pressing <enter> in shell should check for jobs.
3789 * OTOH, in non-interactive shell this is useless
3790 * and only leads to extra job checks */
3791 if (pi->num_cmds == 0) {
3792 if (G_interactive_fd)
3793 goto check_jobs_and_continue;
3797 /* After analyzing all keywords and conditions, we decided
3798 * to execute this pipe. NB: have to do checkjobs(NULL)
3799 * after run_pipe to collect any background children,
3800 * even if list execution is to be stopped. */
3801 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3804 #if ENABLE_HUSH_LOOPS
3805 G.flag_break_continue = 0;
3807 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3809 /* We only ran a builtin: rcode is already known
3810 * and we don't need to wait for anything. */
3811 G.last_exitcode = rcode;
3812 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3813 check_and_run_traps(0);
3814 #if ENABLE_HUSH_LOOPS
3815 /* Was it "break" or "continue"? */
3816 if (G.flag_break_continue) {
3817 smallint fbc = G.flag_break_continue;
3818 /* We might fall into outer *loop*,
3819 * don't want to break it too */
3821 G.depth_break_continue--;
3822 if (G.depth_break_continue == 0)
3823 G.flag_break_continue = 0;
3824 /* else: e.g. "continue 2" should *break* once, *then* continue */
3825 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3826 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3827 goto check_jobs_and_break;
3828 /* "continue": simulate end of loop */
3833 } else if (pi->followup == PIPE_BG) {
3834 /* What does bash do with attempts to background builtins? */
3835 /* even bash 3.2 doesn't do that well with nested bg:
3836 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3837 * I'm NOT treating inner &'s as jobs */
3838 check_and_run_traps(0);
3840 if (G.run_list_level == 1)
3843 G.last_exitcode = rcode = EXIT_SUCCESS;
3844 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3847 if (G.run_list_level == 1 && G_interactive_fd) {
3848 /* Waits for completion, then fg's main shell */
3849 rcode = checkjobs_and_fg_shell(pi);
3850 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3851 check_and_run_traps(0);
3854 { /* This one just waits for completion */
3855 rcode = checkjobs(pi);
3856 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3857 check_and_run_traps(0);
3859 G.last_exitcode = rcode;
3863 /* Analyze how result affects subsequent commands */
3865 if (rword == RES_IF || rword == RES_ELIF)
3868 #if ENABLE_HUSH_LOOPS
3869 /* Beware of "while false; true; do ..."! */
3870 if (pi->next && pi->next->res_word == RES_DO) {
3871 if (rword == RES_WHILE) {
3873 /* "while false; do...done" - exitcode 0 */
3874 G.last_exitcode = rcode = EXIT_SUCCESS;
3875 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3876 goto check_jobs_and_break;
3879 if (rword == RES_UNTIL) {
3881 debug_printf_exec(": until expr is true: breaking\n");
3882 check_jobs_and_break:
3890 check_jobs_and_continue:
3895 //// if (G.ctrl_z_flag) {
3896 //// /* ctrl-Z forked somewhere in the past, we are the child,
3897 //// * and now we completed running the list. Exit. */
3903 //// if (!G.run_list_level && G_interactive_fd) {
3904 //// signal(SIGTSTP, SIG_IGN);
3905 //// signal(SIGINT, SIG_IGN);
3908 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3909 #if ENABLE_HUSH_LOOPS
3914 #if ENABLE_HUSH_CASE
3920 /* Select which version we will use */
3921 static int run_and_free_list(struct pipe *pi)
3924 debug_printf_exec("run_and_free_list entered\n");
3926 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3927 rcode = run_list(pi);
3929 /* free_pipe_list has the side effect of clearing memory.
3930 * In the long run that function can be merged with run_list,
3931 * but doing that now would hobble the debugging effort. */
3932 free_pipe_list(pi, /* indent: */ 0);
3933 debug_printf_exec("run_and_free_list return %d\n", rcode);
3938 static struct pipe *new_pipe(void)
3941 pi = xzalloc(sizeof(struct pipe));
3942 /*pi->followup = 0; - deliberately invalid value */
3943 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3947 /* Command (member of a pipe) is complete. The only possible error here
3948 * is out of memory, in which case xmalloc exits. */
3949 static int done_command(struct parse_context *ctx)
3951 /* The command is really already in the pipe structure, so
3952 * advance the pipe counter and make a new, null command. */
3953 struct pipe *pi = ctx->pipe;
3954 struct command *command = ctx->command;
3957 if (command->group == NULL
3958 && command->argv == NULL
3959 && command->redirects == NULL
3961 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3962 memset(command, 0, sizeof(*command)); /* paranoia */
3963 return pi->num_cmds;
3966 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3967 //debug_print_tree(ctx->list_head, 20);
3969 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3972 /* Only real trickiness here is that the uncommitted
3973 * command structure is not counted in pi->num_cmds. */
3974 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3975 command = &pi->cmds[pi->num_cmds];
3976 memset(command, 0, sizeof(*command));
3978 ctx->command = command;
3979 /* but ctx->pipe and ctx->list_head remain unchanged */
3981 return pi->num_cmds; /* used only for 0/nonzero check */
3984 static void done_pipe(struct parse_context *ctx, pipe_style type)
3988 debug_printf_parse("done_pipe entered, followup %d\n", type);
3989 /* Close previous command */
3990 not_null = done_command(ctx);
3991 ctx->pipe->followup = type;
3993 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3994 ctx->ctx_inverted = 0;
3995 ctx->pipe->res_word = ctx->ctx_res_w;
3998 /* Without this check, even just <enter> on command line generates
3999 * tree of three NOPs (!). Which is harmless but annoying.
4000 * IOW: it is safe to do it unconditionally.
4001 * RES_NONE case is for "for a in; do ..." (empty IN set)
4002 * and other cases to work. */
4005 || ctx->ctx_res_w == RES_FI
4006 || ctx->ctx_res_w == RES_DONE
4007 || ctx->ctx_res_w == RES_FOR
4008 || ctx->ctx_res_w == RES_IN
4009 || ctx->ctx_res_w == RES_ESAC
4013 debug_printf_parse("done_pipe: adding new pipe: "
4014 "not_null:%d ctx->ctx_res_w:%d\n",
4015 not_null, ctx->ctx_res_w);
4017 ctx->pipe->next = new_p;
4019 /* RES_THEN, RES_DO etc are "sticky" -
4020 * they remain set for commands inside if/while.
4021 * This is used to control execution.
4022 * RES_FOR and RES_IN are NOT sticky (needed to support
4023 * cases where variable or value happens to match a keyword):
4025 #if ENABLE_HUSH_LOOPS
4026 if (ctx->ctx_res_w == RES_FOR
4027 || ctx->ctx_res_w == RES_IN)
4028 ctx->ctx_res_w = RES_NONE;
4030 #if ENABLE_HUSH_CASE
4031 if (ctx->ctx_res_w == RES_MATCH)
4032 ctx->ctx_res_w = RES_CASEI;
4034 ctx->command = NULL; /* trick done_command below */
4035 /* Create the memory for command, roughly:
4036 * ctx->pipe->cmds = new struct command;
4037 * ctx->command = &ctx->pipe->cmds[0];
4040 //debug_print_tree(ctx->list_head, 10);
4042 debug_printf_parse("done_pipe return\n");
4045 static void initialize_context(struct parse_context *ctx)
4047 memset(ctx, 0, sizeof(*ctx));
4048 ctx->pipe = ctx->list_head = new_pipe();
4049 /* Create the memory for command, roughly:
4050 * ctx->pipe->cmds = new struct command;
4051 * ctx->command = &ctx->pipe->cmds[0];
4056 /* If a reserved word is found and processed, parse context is modified
4057 * and 1 is returned.
4060 struct reserved_combo {
4063 unsigned char assignment_flag;
4067 FLAG_END = (1 << RES_NONE ),
4069 FLAG_IF = (1 << RES_IF ),
4070 FLAG_THEN = (1 << RES_THEN ),
4071 FLAG_ELIF = (1 << RES_ELIF ),
4072 FLAG_ELSE = (1 << RES_ELSE ),
4073 FLAG_FI = (1 << RES_FI ),
4075 #if ENABLE_HUSH_LOOPS
4076 FLAG_FOR = (1 << RES_FOR ),
4077 FLAG_WHILE = (1 << RES_WHILE),
4078 FLAG_UNTIL = (1 << RES_UNTIL),
4079 FLAG_DO = (1 << RES_DO ),
4080 FLAG_DONE = (1 << RES_DONE ),
4081 FLAG_IN = (1 << RES_IN ),
4083 #if ENABLE_HUSH_CASE
4084 FLAG_MATCH = (1 << RES_MATCH),
4085 FLAG_ESAC = (1 << RES_ESAC ),
4087 FLAG_START = (1 << RES_XXXX ),
4090 static const struct reserved_combo* match_reserved_word(o_string *word)
4092 /* Mostly a list of accepted follow-up reserved words.
4093 * FLAG_END means we are done with the sequence, and are ready
4094 * to turn the compound list into a command.
4095 * FLAG_START means the word must start a new compound list.
4097 static const struct reserved_combo reserved_list[] = {
4099 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4100 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4101 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4102 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4103 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4104 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4106 #if ENABLE_HUSH_LOOPS
4107 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4108 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4109 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4110 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4111 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4112 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4114 #if ENABLE_HUSH_CASE
4115 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4116 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4119 const struct reserved_combo *r;
4121 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4122 if (strcmp(word->data, r->literal) == 0)
4127 static int reserved_word(o_string *word, struct parse_context *ctx)
4129 #if ENABLE_HUSH_CASE
4130 static const struct reserved_combo reserved_match = {
4131 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4134 const struct reserved_combo *r;
4136 r = match_reserved_word(word);
4140 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4141 #if ENABLE_HUSH_CASE
4142 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4143 /* "case word IN ..." - IN part starts first match part */
4144 r = &reserved_match;
4147 if (r->flag == 0) { /* '!' */
4148 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4149 syntax_error("! ! command");
4150 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
4152 ctx->ctx_inverted = 1;
4155 if (r->flag & FLAG_START) {
4156 struct parse_context *old;
4157 old = xmalloc(sizeof(*old));
4158 debug_printf_parse("push stack %p\n", old);
4159 *old = *ctx; /* physical copy */
4160 initialize_context(ctx);
4162 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4163 syntax_error_at(word->data);
4164 ctx->ctx_res_w = RES_SNTX;
4167 ctx->ctx_res_w = r->res;
4168 ctx->old_flag = r->flag;
4169 if (ctx->old_flag & FLAG_END) {
4170 struct parse_context *old;
4171 done_pipe(ctx, PIPE_SEQ);
4172 debug_printf_parse("pop stack %p\n", ctx->stack);
4174 old->command->group = ctx->list_head;
4175 old->command->grp_type = GRP_NORMAL;
4177 o_addstr(&old->as_string, ctx->as_string.data);
4178 o_free_unsafe(&ctx->as_string);
4179 old->command->group_as_string = xstrdup(old->as_string.data);
4180 debug_printf_parse("pop, remembering as:'%s'\n",
4181 old->command->group_as_string);
4183 *ctx = *old; /* physical copy */
4186 word->o_assignment = r->assignment_flag;
4191 /* Word is complete, look at it and update parsing context.
4192 * Normal return is 0. Syntax errors return 1.
4193 * Note: on return, word is reset, but not o_free'd!
4195 static int done_word(o_string *word, struct parse_context *ctx)
4197 struct command *command = ctx->command;
4199 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4200 if (word->length == 0 && word->o_quoted == 0) {
4201 debug_printf_parse("done_word return 0: true null, ignored\n");
4205 if (ctx->pending_redirect) {
4206 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4207 * only if run as "bash", not "sh" */
4208 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4210 * ...the word that follows the redirection operator
4211 * shall be subjected to tilde expansion, parameter expansion,
4212 * command substitution, arithmetic expansion, and quote
4213 * removal. Pathname expansion shall not be performed
4214 * on the word by a non-interactive shell; an interactive
4215 * shell may perform it, but shall do so only when
4216 * the expansion would result in one word."
4218 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4219 /* Cater for >\file case:
4220 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4221 * Same with heredocs:
4222 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4224 unbackslash(ctx->pending_redirect->rd_filename);
4225 /* Is it <<"HEREDOC"? */
4226 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4229 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4231 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4232 ctx->pending_redirect = NULL;
4234 /* If this word wasn't an assignment, next ones definitely
4235 * can't be assignments. Even if they look like ones. */
4236 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4237 && word->o_assignment != WORD_IS_KEYWORD
4239 word->o_assignment = NOT_ASSIGNMENT;
4241 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4242 command->assignment_cnt++;
4243 word->o_assignment = MAYBE_ASSIGNMENT;
4246 if (command->group) {
4247 /* "{ echo foo; } echo bar" - bad */
4248 /* NB: bash allows e.g.:
4249 * if true; then { echo foo; } fi
4250 * while if false; then false; fi do break; done
4252 * while if false; then false; fi; do; break; done
4254 syntax_error_at(word->data);
4255 debug_printf_parse("done_word return 1: syntax error, "
4256 "groups and arglists don't mix\n");
4260 # if ENABLE_HUSH_CASE
4261 if (ctx->ctx_dsemicolon
4262 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4264 /* already done when ctx_dsemicolon was set to 1: */
4265 /* ctx->ctx_res_w = RES_MATCH; */
4266 ctx->ctx_dsemicolon = 0;
4269 if (!command->argv /* if it's the first word... */
4270 # if ENABLE_HUSH_LOOPS
4271 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4272 && ctx->ctx_res_w != RES_IN
4275 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
4276 if (reserved_word(word, ctx)) {
4277 o_reset_to_empty_unquoted(word);
4278 debug_printf_parse("done_word return %d\n",
4279 (ctx->ctx_res_w == RES_SNTX));
4280 return (ctx->ctx_res_w == RES_SNTX);
4284 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4285 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4286 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4287 /* (otherwise it's known to be not empty and is already safe) */
4289 /* exclude "$@" - it can expand to no word despite "" */
4290 char *p = word->data;
4291 while (p[0] == SPECIAL_VAR_SYMBOL
4292 && (p[1] & 0x7f) == '@'
4293 && p[2] == SPECIAL_VAR_SYMBOL
4297 if (p == word->data || p[0] != '\0') {
4298 /* saw no "$@", or not only "$@" but some
4299 * real text is there too */
4300 /* insert "empty variable" reference, this makes
4301 * e.g. "", $empty"" etc to not disappear */
4302 o_addchr(word, SPECIAL_VAR_SYMBOL);
4303 o_addchr(word, SPECIAL_VAR_SYMBOL);
4306 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4307 //SEGV, but good idea.
4308 // command->argv = add_string_to_strings(command->argv, word->data);
4309 // word->data = NULL;
4310 // word->length = 0;
4311 debug_print_strings("word appended to argv", command->argv);
4314 #if ENABLE_HUSH_LOOPS
4315 if (ctx->ctx_res_w == RES_FOR) {
4317 || !is_well_formed_var_name(command->argv[0], '\0')
4319 /* bash says just "not a valid identifier" */
4320 syntax_error("not a valid identifier in for");
4323 /* Force FOR to have just one word (variable name) */
4324 /* NB: basically, this makes hush see "for v in ..."
4325 * syntax as if it is "for v; in ...". FOR and IN become
4326 * two pipe structs in parse tree. */
4327 done_pipe(ctx, PIPE_SEQ);
4330 #if ENABLE_HUSH_CASE
4331 /* Force CASE to have just one word */
4332 if (ctx->ctx_res_w == RES_CASE) {
4333 done_pipe(ctx, PIPE_SEQ);
4337 o_reset_to_empty_unquoted(word);
4339 debug_printf_parse("done_word return 0\n");
4344 /* Peek ahead in the input to find out if we have a "&n" construct,
4345 * as in "2>&1", that represents duplicating a file descriptor.
4347 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4348 * REDIRFD_SYNTAX_ERR if syntax error,
4349 * REDIRFD_TO_FILE if no & was seen,
4350 * or the number found.
4353 #define parse_redir_right_fd(as_string, input) \
4354 parse_redir_right_fd(input)
4356 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4362 return REDIRFD_TO_FILE;
4364 ch = i_getch(input); /* get the & */
4365 nommu_addchr(as_string, ch);
4368 ch = i_getch(input);
4369 nommu_addchr(as_string, ch);
4370 return REDIRFD_CLOSE;
4374 while (ch != EOF && isdigit(ch)) {
4375 d = d*10 + (ch-'0');
4377 ch = i_getch(input);
4378 nommu_addchr(as_string, ch);
4383 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4385 bb_error_msg("ambiguous redirect");
4386 return REDIRFD_SYNTAX_ERR;
4389 /* Return code is 0 normal, 1 if a syntax error is detected
4391 static int parse_redirect(struct parse_context *ctx,
4394 struct in_str *input)
4396 struct command *command = ctx->command;
4397 struct redir_struct *redir;
4398 struct redir_struct **redirp;
4401 dup_num = REDIRFD_TO_FILE;
4402 if (style != REDIRECT_HEREDOC) {
4403 /* Check for a '>&1' type redirect */
4404 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4405 if (dup_num == REDIRFD_SYNTAX_ERR)
4408 int ch = i_peek(input);
4409 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4410 if (dup_num) { /* <<-... */
4411 ch = i_getch(input);
4412 nommu_addchr(&ctx->as_string, ch);
4417 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4418 int ch = i_peek(input);
4420 /* >|FILE redirect ("clobbering" >).
4421 * Since we do not support "set -o noclobber" yet,
4422 * >| and > are the same for now. Just eat |.
4424 ch = i_getch(input);
4425 nommu_addchr(&ctx->as_string, ch);
4429 /* Create a new redir_struct and append it to the linked list */
4430 redirp = &command->redirects;
4431 while ((redir = *redirp) != NULL) {
4432 redirp = &(redir->next);
4434 *redirp = redir = xzalloc(sizeof(*redir));
4435 /* redir->next = NULL; */
4436 /* redir->rd_filename = NULL; */
4437 redir->rd_type = style;
4438 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4440 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4441 redir_table[style].descrip);
4443 redir->rd_dup = dup_num;
4444 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4445 /* Erik had a check here that the file descriptor in question
4446 * is legit; I postpone that to "run time"
4447 * A "-" representation of "close me" shows up as a -3 here */
4448 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4449 redir->rd_fd, redir->rd_dup);
4451 /* Set ctx->pending_redirect, so we know what to do at the
4452 * end of the next parsed word. */
4453 ctx->pending_redirect = redir;
4458 /* If a redirect is immediately preceded by a number, that number is
4459 * supposed to tell which file descriptor to redirect. This routine
4460 * looks for such preceding numbers. In an ideal world this routine
4461 * needs to handle all the following classes of redirects...
4462 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4463 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4464 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4465 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4467 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4469 * ... If n is quoted, the number shall not be recognized as part of
4470 * the redirection expression. For example:
4472 * writes the character 2 into file a"
4473 * We are getting it right by setting ->o_quoted on any \<char>
4475 * A -1 return means no valid number was found,
4476 * the caller should use the appropriate default for this redirection.
4478 static int redirect_opt_num(o_string *o)
4482 if (o->data == NULL)
4484 num = bb_strtou(o->data, NULL, 10);
4485 if (errno || num < 0)
4487 o_reset_to_empty_unquoted(o);
4492 #define fetch_till_str(as_string, input, word, skip_tabs) \
4493 fetch_till_str(input, word, skip_tabs)
4495 static char *fetch_till_str(o_string *as_string,
4496 struct in_str *input,
4500 o_string heredoc = NULL_O_STRING;
4506 ch = i_getch(input);
4507 nommu_addchr(as_string, ch);
4509 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4510 heredoc.data[past_EOL] = '\0';
4511 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4512 return heredoc.data;
4515 o_addchr(&heredoc, ch);
4516 past_EOL = heredoc.length;
4519 ch = i_getch(input);
4520 nommu_addchr(as_string, ch);
4521 } while (skip_tabs && ch == '\t');
4522 } while (ch == '\n');
4525 o_free_unsafe(&heredoc);
4528 o_addchr(&heredoc, ch);
4529 nommu_addchr(as_string, ch);
4533 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4534 * and load them all. There should be exactly heredoc_cnt of them.
4536 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4538 struct pipe *pi = ctx->list_head;
4540 while (pi && heredoc_cnt) {
4542 struct command *cmd = pi->cmds;
4544 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4546 cmd->argv ? cmd->argv[0] : "NONE");
4547 for (i = 0; i < pi->num_cmds; i++) {
4548 struct redir_struct *redir = cmd->redirects;
4550 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4551 i, cmd->argv ? cmd->argv[0] : "NONE");
4553 if (redir->rd_type == REDIRECT_HEREDOC) {
4556 redir->rd_type = REDIRECT_HEREDOC2;
4557 /* redir->dup is (ab)used to indicate <<- */
4558 p = fetch_till_str(&ctx->as_string, input,
4559 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4561 syntax_error("unexpected EOF in here document");
4564 free(redir->rd_filename);
4565 redir->rd_filename = p;
4568 redir = redir->next;
4575 /* Should be 0. If it isn't, it's a parse error */
4577 bb_error_msg_and_die("heredoc BUG 2");
4584 #define parse_stream(pstring, input, end_trigger) \
4585 parse_stream(input, end_trigger)
4587 static struct pipe *parse_stream(char **pstring,
4588 struct in_str *input,
4590 static void parse_and_run_string(const char *s);
4592 #if ENABLE_HUSH_TICK
4593 static FILE *generate_stream_from_string(const char *s)
4596 int pid, channel[2];
4599 pid = BB_MMU ? fork() : vfork();
4601 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4603 if (pid == 0) { /* child */
4604 disable_restore_tty_pgrp_on_exit();
4605 /* Process substitution is not considered to be usual
4606 * 'command execution'.
4607 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4614 close(channel[0]); /* NB: close _first_, then move fd! */
4615 xmove_fd(channel[1], 1);
4616 /* Prevent it from trying to handle ctrl-z etc */
4617 USE_HUSH_JOB(G.run_list_level = 1;)
4619 reset_traps_to_defaults();
4620 parse_and_run_string(s);
4621 _exit(G.last_exitcode);
4623 /* We re-execute after vfork on NOMMU. This makes this script safe:
4624 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4625 * huge=`cat BIG` # was blocking here forever
4635 enable_restore_tty_pgrp_on_exit();
4636 clean_up_after_re_execute();
4638 pf = fdopen(channel[0], "r");
4642 /* Return code is exit status of the process that is run. */
4643 static int process_command_subs(o_string *dest, const char *s)
4646 struct in_str pipe_str;
4649 pf = generate_stream_from_string(s);
4652 close_on_exec_on(fileno(pf));
4654 /* Now send results of command back into original context */
4655 setup_file_in_str(&pipe_str, pf);
4657 while ((ch = i_getch(&pipe_str)) != EOF) {
4663 o_addchr(dest, '\n');
4666 o_addQchr(dest, ch);
4669 debug_printf("done reading from pipe, pclose()ing\n");
4670 /* Note: we got EOF, and we just close the read end of the pipe.
4671 * We do not wait for the `cmd` child to terminate. bash and ash do.
4673 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4674 * `false`; echo $? - bash outputs "1"
4677 debug_printf("closed FILE from child. return 0\n");
4682 static int parse_group(o_string *dest, struct parse_context *ctx,
4683 struct in_str *input, int ch)
4685 /* dest contains characters seen prior to ( or {.
4686 * Typically it's empty, but for function defs,
4687 * it contains function name (without '()'). */
4688 struct pipe *pipe_list;
4690 struct command *command = ctx->command;
4692 debug_printf_parse("parse_group entered\n");
4693 #if ENABLE_HUSH_FUNCTIONS
4694 if (ch == '(' && !dest->o_quoted) {
4696 done_word(dest, ctx);
4698 goto skip; /* (... */
4699 if (command->argv[1]) { /* word word ... (... */
4700 syntax_error_unexpected_ch('(');
4703 /* it is "word(..." or "word (..." */
4705 ch = i_getch(input);
4706 while (ch == ' ' || ch == '\t');
4708 syntax_error_unexpected_ch(ch);
4711 nommu_addchr(&ctx->as_string, ch);
4713 ch = i_getch(input);
4714 while (ch == ' ' || ch == '\t' || ch == '\n');
4716 syntax_error_unexpected_ch(ch);
4719 nommu_addchr(&ctx->as_string, ch);
4720 command->grp_type = GRP_FUNCTION;
4724 if (command->argv /* word [word]{... */
4725 || dest->length /* word{... */
4726 || dest->o_quoted /* ""{... */
4729 debug_printf_parse("parse_group return 1: "
4730 "syntax error, groups and arglists don't mix\n");
4734 #if ENABLE_HUSH_FUNCTIONS
4740 command->grp_type = GRP_SUBSHELL;
4745 char *as_string = NULL;
4747 pipe_list = parse_stream(&as_string, input, endch);
4750 o_addstr(&ctx->as_string, as_string);
4752 /* empty ()/{} or parse error? */
4753 if (!pipe_list || pipe_list == ERR_PTR) {
4758 debug_printf_parse("parse_group return 1: "
4759 "parse_stream returned %p\n", pipe_list);
4762 command->group = pipe_list;
4764 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4765 command->group_as_string = as_string;
4766 debug_printf_parse("end of group, remembering as:'%s'\n",
4767 command->group_as_string);
4770 debug_printf_parse("parse_group return 0\n");
4772 /* command remains "open", available for possible redirects */
4775 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4776 /* Subroutines for copying $(...) and `...` things */
4777 static void add_till_backquote(o_string *dest, struct in_str *input);
4779 static void add_till_single_quote(o_string *dest, struct in_str *input)
4782 int ch = i_getch(input);
4784 syntax_error_unterm_ch('\'');
4785 /*xfunc_die(); - redundant */
4792 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4793 static void add_till_double_quote(o_string *dest, struct in_str *input)
4796 int ch = i_getch(input);
4798 syntax_error_unterm_ch('"');
4799 /*xfunc_die(); - redundant */
4803 if (ch == '\\') { /* \x. Copy both chars. */
4805 ch = i_getch(input);
4809 add_till_backquote(dest, input);
4813 //if (ch == '$') ...
4816 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4818 * "Within the backquoted style of command substitution, backslash
4819 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4820 * The search for the matching backquote shall be satisfied by the first
4821 * backquote found without a preceding backslash; during this search,
4822 * if a non-escaped backquote is encountered within a shell comment,
4823 * a here-document, an embedded command substitution of the $(command)
4824 * form, or a quoted string, undefined results occur. A single-quoted
4825 * or double-quoted string that begins, but does not end, within the
4826 * "`...`" sequence produces undefined results."
4828 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4830 static void add_till_backquote(o_string *dest, struct in_str *input)
4833 int ch = i_getch(input);
4835 syntax_error_unterm_ch('`');
4836 /*xfunc_die(); - redundant */
4841 /* \x. Copy both chars unless it is \` */
4842 int ch2 = i_getch(input);
4844 syntax_error_unterm_ch('`');
4845 /*xfunc_die(); - redundant */
4847 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4854 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4855 * quoting and nested ()s.
4856 * "With the $(command) style of command substitution, all characters
4857 * following the open parenthesis to the matching closing parenthesis
4858 * constitute the command. Any valid shell script can be used for command,
4859 * except a script consisting solely of redirections which produces
4860 * unspecified results."
4862 * echo $(echo '(TEST)' BEST) (TEST) BEST
4863 * echo $(echo 'TEST)' BEST) TEST) BEST
4864 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4866 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4870 int ch = i_getch(input);
4872 syntax_error_unterm_ch(')');
4873 /*xfunc_die(); - redundant */
4881 if (i_peek(input) == ')') {
4889 add_till_single_quote(dest, input);
4894 add_till_double_quote(dest, input);
4899 /* \x. Copy verbatim. Important for \(, \) */
4900 ch = i_getch(input);
4902 syntax_error_unterm_ch(')');
4903 /*xfunc_die(); - redundant */
4910 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4912 /* Return code: 0 for OK, 1 for syntax error */
4914 #define handle_dollar(as_string, dest, input) \
4915 handle_dollar(dest, input)
4917 static int handle_dollar(o_string *as_string,
4919 struct in_str *input)
4922 int ch = i_peek(input); /* first character after the $ */
4923 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4925 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4927 ch = i_getch(input);
4928 nommu_addchr(as_string, ch);
4930 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4932 debug_printf_parse(": '%c'\n", ch);
4933 o_addchr(dest, ch | quote_mask);
4936 if (!isalnum(ch) && ch != '_')
4938 ch = i_getch(input);
4939 nommu_addchr(as_string, ch);
4941 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4942 } else if (isdigit(ch)) {
4944 ch = i_getch(input);
4945 nommu_addchr(as_string, ch);
4946 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4947 debug_printf_parse(": '%c'\n", ch);
4948 o_addchr(dest, ch | quote_mask);
4949 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4950 } else switch (ch) {
4952 case '!': /* last bg pid */
4953 case '?': /* last exit code */
4954 case '#': /* number of args */
4955 case '*': /* args */
4956 case '@': /* args */
4957 goto make_one_char_var;
4959 bool first_char, all_digits;
4961 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4962 ch = i_getch(input);
4963 nommu_addchr(as_string, ch);
4964 /* XXX maybe someone will try to escape the '}' */
4969 ch = i_getch(input);
4970 nommu_addchr(as_string, ch);
4976 /* ${#var}: length of var contents */
4978 else if (isdigit(ch)) {
4985 && ( (all_digits && !isdigit(ch))
4986 || (!all_digits && !isalnum(ch) && ch != '_')
4989 /* handle parameter expansions
4990 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4995 case ':': /* null modifier */
4996 if (expansion == 0) {
4997 debug_printf_parse(": null modifier\n");
5002 case '#': /* remove prefix */
5003 case '%': /* remove suffix */
5004 if (expansion == 0) {
5005 debug_printf_parse(": remove suffix/prefix\n");
5010 case '-': /* default value */
5011 case '=': /* assign default */
5012 case '+': /* alternative */
5013 case '?': /* error indicate */
5014 debug_printf_parse(": parameter expansion\n");
5019 syntax_error_unterm_str("${name}");
5020 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5025 debug_printf_parse(": '%c'\n", ch);
5026 o_addchr(dest, ch | quote_mask);
5030 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5033 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5038 ch = i_getch(input);
5039 nommu_addchr(as_string, ch);
5040 # if ENABLE_SH_MATH_SUPPORT
5041 if (i_peek(input) == '(') {
5042 ch = i_getch(input);
5043 nommu_addchr(as_string, ch);
5044 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5045 o_addchr(dest, /*quote_mask |*/ '+');
5049 add_till_closing_paren(dest, input, true);
5052 o_addstr(as_string, dest->data + pos);
5053 o_addchr(as_string, ')');
5054 o_addchr(as_string, ')');
5057 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5061 # if ENABLE_HUSH_TICK
5062 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5063 o_addchr(dest, quote_mask | '`');
5067 add_till_closing_paren(dest, input, false);
5070 o_addstr(as_string, dest->data + pos);
5071 o_addchr(as_string, '`');
5074 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5080 ch = i_getch(input);
5081 nommu_addchr(as_string, ch);
5083 if (isalnum(ch)) { /* it's $_name or $_123 */
5089 /* $_ Shell or shell script name; or last cmd name */
5090 /* $- Option flags set by set builtin or shell options (-i etc) */
5092 o_addQchr(dest, '$');
5094 debug_printf_parse("handle_dollar return 0\n");
5099 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5100 parse_stream_dquoted(dest, input, dquote_end)
5102 static int parse_stream_dquoted(o_string *as_string,
5104 struct in_str *input,
5111 ch = i_getch(input);
5113 nommu_addchr(as_string, ch);
5114 if (ch == dquote_end) { /* may be only '"' or EOF */
5115 if (dest->o_assignment == NOT_ASSIGNMENT)
5116 dest->o_escape ^= 1;
5117 debug_printf_parse("parse_stream_dquoted return 0\n");
5120 /* note: can't move it above ch == dquote_end check! */
5122 syntax_error_unterm_ch('"');
5123 /*xfunc_die(); - redundant */
5127 next = i_peek(input);
5129 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5130 ch, ch, dest->o_escape);
5133 syntax_error("\\<eof>");
5137 * "The backslash retains its special meaning [in "..."]
5138 * only when followed by one of the following characters:
5139 * $, `, ", \, or <newline>. A double quote may be quoted
5140 * within double quotes by preceding it with a backslash.
5142 if (strchr("$`\"\\", next) != NULL) {
5143 o_addqchr(dest, i_getch(input));
5145 o_addqchr(dest, '\\');
5150 if (handle_dollar(as_string, dest, input) != 0) {
5151 debug_printf_parse("parse_stream_dquoted return 1: "
5152 "handle_dollar returned non-0\n");
5157 #if ENABLE_HUSH_TICK
5159 //int pos = dest->length;
5160 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5161 o_addchr(dest, 0x80 | '`');
5162 add_till_backquote(dest, input);
5163 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5164 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5168 o_addQchr(dest, ch);
5170 && (dest->o_assignment == MAYBE_ASSIGNMENT
5171 || dest->o_assignment == WORD_IS_KEYWORD)
5172 && is_well_formed_var_name(dest->data, '=')
5174 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5180 * Scan input until EOF or end_trigger char.
5181 * Return a list of pipes to execute, or NULL on EOF
5182 * or if end_trigger character is met.
5183 * On syntax error, exit is shell is not interactive,
5184 * reset parsing machinery and start parsing anew,
5185 * or return ERR_PTR.
5187 static struct pipe *parse_stream(char **pstring,
5188 struct in_str *input,
5191 struct parse_context ctx;
5192 o_string dest = NULL_O_STRING;
5196 /* Double-quote state is handled in the state variable is_in_dquote.
5197 * A single-quote triggers a bypass of the main loop until its mate is
5198 * found. When recursing, quote state is passed in via dest->o_escape.
5200 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5201 end_trigger ? : 'X');
5203 G.ifs = get_local_var_value("IFS");
5208 #if ENABLE_HUSH_INTERACTIVE
5209 input->promptmode = 0; /* PS1 */
5211 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5212 initialize_context(&ctx);
5217 const char *is_special;
5221 redir_type redir_style;
5224 /* dest.o_quoted = 1; - already is (see below) */
5225 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5228 /* We reached closing '"' */
5231 ch = i_getch(input);
5232 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5233 ch, ch, dest.o_escape);
5238 syntax_error_unterm_str("here document");
5241 if (done_word(&dest, &ctx)) {
5245 done_pipe(&ctx, PIPE_SEQ);
5247 /* If we got nothing... */
5248 /* (this makes bare "&" cmd a no-op.
5249 * bash says: "syntax error near unexpected token '&'") */
5250 if (pi->num_cmds == 0
5251 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5253 free_pipe_list(pi, 0);
5256 debug_printf_parse("parse_stream return %p\n", pi);
5258 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5260 *pstring = ctx.as_string.data;
5262 o_free_unsafe(&ctx.as_string);
5266 nommu_addchr(&ctx.as_string, ch);
5267 is_ifs = strchr(G.ifs, ch);
5268 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5269 "\\$\"" USE_HUSH_TICK("`") /* always special */
5272 if (!is_special && !is_ifs) { /* ordinary char */
5273 o_addQchr(&dest, ch);
5274 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5275 || dest.o_assignment == WORD_IS_KEYWORD)
5277 && is_well_formed_var_name(dest.data, '=')
5279 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5285 if (done_word(&dest, &ctx)) {
5289 #if ENABLE_HUSH_CASE
5290 /* "case ... in <newline> word) ..." -
5291 * newlines are ignored (but ';' wouldn't be) */
5292 if (ctx.command->argv == NULL
5293 && ctx.ctx_res_w == RES_MATCH
5298 /* Treat newline as a command separator. */
5299 done_pipe(&ctx, PIPE_SEQ);
5300 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5302 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5307 dest.o_assignment = MAYBE_ASSIGNMENT;
5309 /* note: if (is_ifs) continue;
5310 * will still trigger for us */
5313 if (end_trigger && end_trigger == ch
5314 && (heredoc_cnt == 0 || end_trigger != ';')
5316 //TODO: disallow "{ cmd }" without semicolon
5318 /* This is technically valid:
5319 * { cat <<HERE; }; echo Ok
5324 * but we don't support this.
5325 * We require heredoc to be in enclosing {}/(),
5328 syntax_error_unterm_str("here document");
5331 if (done_word(&dest, &ctx)) {
5334 done_pipe(&ctx, PIPE_SEQ);
5335 dest.o_assignment = MAYBE_ASSIGNMENT;
5336 /* Do we sit outside of any if's, loops or case's? */
5338 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5340 debug_printf_parse("parse_stream return %p: "
5341 "end_trigger char found\n",
5345 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5347 *pstring = ctx.as_string.data;
5349 o_free_unsafe(&ctx.as_string);
5351 return ctx.list_head;
5359 next = i_peek(input);
5362 /* Catch <, > before deciding whether this word is
5363 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5366 redir_fd = redirect_opt_num(&dest);
5367 if (done_word(&dest, &ctx)) {
5370 redir_style = REDIRECT_OVERWRITE;
5372 redir_style = REDIRECT_APPEND;
5373 ch = i_getch(input);
5374 nommu_addchr(&ctx.as_string, ch);
5377 else if (next == '(') {
5378 syntax_error(">(process) not supported");
5382 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5384 continue; /* back to top of while (1) */
5386 redir_fd = redirect_opt_num(&dest);
5387 if (done_word(&dest, &ctx)) {
5390 redir_style = REDIRECT_INPUT;
5392 redir_style = REDIRECT_HEREDOC;
5394 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5395 ch = i_getch(input);
5396 nommu_addchr(&ctx.as_string, ch);
5397 } else if (next == '>') {
5398 redir_style = REDIRECT_IO;
5399 ch = i_getch(input);
5400 nommu_addchr(&ctx.as_string, ch);
5403 else if (next == '(') {
5404 syntax_error("<(process) not supported");
5408 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5410 continue; /* back to top of while (1) */
5413 if (dest.o_assignment == MAYBE_ASSIGNMENT
5414 /* check that we are not in word in "a=1 2>word b=1": */
5415 && !ctx.pending_redirect
5417 /* ch is a special char and thus this word
5418 * cannot be an assignment */
5419 dest.o_assignment = NOT_ASSIGNMENT;
5424 if (dest.length == 0) {
5427 if (ch == EOF || ch == '\n')
5430 /* note: we do not add it to &ctx.as_string */
5432 nommu_addchr(&ctx.as_string, '\n');
5434 o_addQchr(&dest, ch);
5439 syntax_error("\\<eof>");
5442 o_addchr(&dest, '\\');
5443 ch = i_getch(input);
5444 nommu_addchr(&ctx.as_string, ch);
5445 o_addchr(&dest, ch);
5446 /* Example: echo Hello \2>file
5447 * we need to know that word 2 is quoted */
5451 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5452 debug_printf_parse("parse_stream parse error: "
5453 "handle_dollar returned non-0\n");
5460 ch = i_getch(input);
5462 syntax_error_unterm_ch('\'');
5463 /*xfunc_die(); - redundant */
5465 nommu_addchr(&ctx.as_string, ch);
5468 if (dest.o_assignment == NOT_ASSIGNMENT)
5469 o_addqchr(&dest, ch);
5471 o_addchr(&dest, ch);
5476 is_in_dquote ^= 1; /* invert */
5477 if (dest.o_assignment == NOT_ASSIGNMENT)
5480 #if ENABLE_HUSH_TICK
5485 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5486 o_addchr(&dest, '`');
5490 add_till_backquote(&dest, input);
5492 o_addstr(&ctx.as_string, dest.data + pos);
5493 o_addchr(&ctx.as_string, '`');
5495 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5496 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5501 #if ENABLE_HUSH_CASE
5504 if (done_word(&dest, &ctx)) {
5507 done_pipe(&ctx, PIPE_SEQ);
5508 #if ENABLE_HUSH_CASE
5509 /* Eat multiple semicolons, detect
5510 * whether it means something special */
5515 ch = i_getch(input);
5516 nommu_addchr(&ctx.as_string, ch);
5517 if (ctx.ctx_res_w == RES_CASEI) {
5518 ctx.ctx_dsemicolon = 1;
5519 ctx.ctx_res_w = RES_MATCH;
5525 /* We just finished a cmd. New one may start
5526 * with an assignment */
5527 dest.o_assignment = MAYBE_ASSIGNMENT;
5530 if (done_word(&dest, &ctx)) {
5534 ch = i_getch(input);
5535 nommu_addchr(&ctx.as_string, ch);
5536 done_pipe(&ctx, PIPE_AND);
5538 done_pipe(&ctx, PIPE_BG);
5542 if (done_word(&dest, &ctx)) {
5545 #if ENABLE_HUSH_CASE
5546 if (ctx.ctx_res_w == RES_MATCH)
5547 break; /* we are in case's "word | word)" */
5549 if (next == '|') { /* || */
5550 ch = i_getch(input);
5551 nommu_addchr(&ctx.as_string, ch);
5552 done_pipe(&ctx, PIPE_OR);
5554 /* we could pick up a file descriptor choice here
5555 * with redirect_opt_num(), but bash doesn't do it.
5556 * "echo foo 2| cat" yields "foo 2". */
5561 #if ENABLE_HUSH_CASE
5562 /* "case... in [(]word)..." - skip '(' */
5563 if (ctx.ctx_res_w == RES_MATCH
5564 && ctx.command->argv == NULL /* not (word|(... */
5565 && dest.length == 0 /* not word(... */
5566 && dest.o_quoted == 0 /* not ""(... */
5572 if (parse_group(&dest, &ctx, input, ch) != 0) {
5577 #if ENABLE_HUSH_CASE
5578 if (ctx.ctx_res_w == RES_MATCH)
5582 /* proper use of this character is caught by end_trigger:
5583 * if we see {, we call parse_group(..., end_trigger='}')
5584 * and it will match } earlier (not here). */
5585 syntax_error_unexpected_ch(ch);
5589 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5595 struct parse_context *pctx;
5596 IF_HAS_KEYWORDS(struct parse_context *p2;)
5598 /* Clean up allocated tree.
5599 * Samples for finding leaks on syntax error recovery path.
5600 * Run them from interactive shell, watch pmap `pidof hush`.
5601 * while if false; then false; fi do break; done
5603 * while if false; then false; fi; do break; fi
5604 * Samples to catch leaks at execution:
5605 * while if (true | {true;}); then echo ok; fi; do break; done
5606 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5610 /* Update pipe/command counts,
5611 * otherwise freeing may miss some */
5612 done_pipe(pctx, PIPE_SEQ);
5613 debug_printf_clean("freeing list %p from ctx %p\n",
5614 pctx->list_head, pctx);
5615 debug_print_tree(pctx->list_head, 0);
5616 free_pipe_list(pctx->list_head, 0);
5617 debug_printf_clean("freed list %p\n", pctx->list_head);
5619 o_free_unsafe(&pctx->as_string);
5621 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5625 IF_HAS_KEYWORDS(pctx = p2;)
5626 } while (HAS_KEYWORDS && pctx);
5627 /* Free text, clear all dest fields */
5629 /* If we are not in top-level parse, we return,
5630 * our caller will propagate error.
5632 if (end_trigger != ';') {
5639 /* Discard cached input, force prompt */
5641 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5646 /* Executing from string: eval, sh -c '...'
5647 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5648 * end_trigger controls how often we stop parsing
5649 * NUL: parse all, execute, return
5650 * ';': parse till ';' or newline, execute, repeat till EOF
5652 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5655 struct pipe *pipe_list;
5657 pipe_list = parse_stream(NULL, inp, end_trigger);
5658 if (!pipe_list) /* EOF */
5660 debug_print_tree(pipe_list, 0);
5661 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5662 run_and_free_list(pipe_list);
5666 static void parse_and_run_string(const char *s)
5668 struct in_str input;
5669 setup_string_in_str(&input, s);
5670 parse_and_run_stream(&input, '\0');
5673 static void parse_and_run_file(FILE *f)
5675 struct in_str input;
5676 setup_file_in_str(&input, f);
5677 parse_and_run_stream(&input, ';');
5680 /* Called a few times only (or even once if "sh -c") */
5681 static void block_signals(int second_time)
5686 mask = (1 << SIGQUIT);
5687 if (G_interactive_fd) {
5691 //TODO | (1 << SIGHUP)
5693 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5698 G.non_DFL_mask = mask;
5701 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5705 sigaddset(&G.blocked_set, sig);
5709 sigdelset(&G.blocked_set, SIGCHLD);
5711 sigprocmask(SIG_SETMASK, &G.blocked_set,
5712 second_time ? NULL : &G.inherited_set);
5713 /* POSIX allows shell to re-enable SIGCHLD
5714 * even if it was SIG_IGN on entry */
5715 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5717 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5722 static void maybe_set_to_sigexit(int sig)
5724 void (*handler)(int);
5725 /* non_DFL_mask'ed signals are, well, masked,
5726 * no need to set handler for them.
5728 if (!((G.non_DFL_mask >> sig) & 1)) {
5729 handler = signal(sig, sigexit);
5730 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5731 signal(sig, handler);
5734 /* Set handlers to restore tty pgrp and exit */
5735 static void set_fatal_handlers(void)
5737 /* We _must_ restore tty pgrp on fatal signals */
5739 maybe_set_to_sigexit(SIGILL );
5740 maybe_set_to_sigexit(SIGFPE );
5741 maybe_set_to_sigexit(SIGBUS );
5742 maybe_set_to_sigexit(SIGSEGV);
5743 maybe_set_to_sigexit(SIGTRAP);
5744 } /* else: hush is perfect. what SEGV? */
5745 maybe_set_to_sigexit(SIGABRT);
5746 /* bash 3.2 seems to handle these just like 'fatal' ones */
5747 maybe_set_to_sigexit(SIGPIPE);
5748 maybe_set_to_sigexit(SIGALRM);
5749 //TODO: disable and move down when proper SIGHUP handling is added
5750 maybe_set_to_sigexit(SIGHUP );
5751 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5752 * if we aren't interactive... but in this case
5753 * we never want to restore pgrp on exit, and this fn is not called */
5754 /*maybe_set_to_sigexit(SIGTERM);*/
5755 /*maybe_set_to_sigexit(SIGINT );*/
5759 static int set_mode(const char cstate, const char mode)
5761 int state = (cstate == '-' ? 1 : 0);
5763 case 'n': G.fake_mode = state; break;
5764 case 'x': /*G.debug_mode = state;*/ break;
5765 default: return EXIT_FAILURE;
5767 return EXIT_SUCCESS;
5770 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5771 int hush_main(int argc, char **argv)
5773 static const struct variable const_shell_ver = {
5775 .varstr = (char*)hush_version_str,
5776 .max_len = 1, /* 0 can provoke free(name) */
5780 int signal_mask_is_inited = 0;
5783 struct variable *cur_var;
5786 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5787 G.last_exitcode = EXIT_SUCCESS;
5789 G.argv0_for_re_execing = argv[0];
5791 /* Deal with HUSH_VERSION */
5792 G.shell_ver = const_shell_ver; /* copying struct here */
5793 G.top_var = &G.shell_ver;
5794 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5795 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5796 /* Initialize our shell local variables with the values
5797 * currently living in the environment */
5798 cur_var = G.top_var;
5801 char *value = strchr(*e, '=');
5802 if (value) { /* paranoia */
5803 cur_var->next = xzalloc(sizeof(*cur_var));
5804 cur_var = cur_var->next;
5805 cur_var->varstr = *e;
5806 cur_var->max_len = strlen(*e);
5807 cur_var->flg_export = 1;
5811 debug_printf_env("putenv '%s'\n", hush_version_str);
5812 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5813 #if ENABLE_FEATURE_EDITING
5814 G.line_input_state = new_line_input_t(FOR_SHELL);
5816 G.global_argc = argc;
5817 G.global_argv = argv;
5818 /* Initialize some more globals to non-zero values */
5820 #if ENABLE_HUSH_INTERACTIVE
5821 if (ENABLE_FEATURE_EDITING)
5822 cmdedit_set_initial_prompt();
5826 if (setjmp(die_jmp)) {
5827 /* xfunc has failed! die die die */
5828 /* no EXIT traps, this is an escape hatch! */
5830 hush_exit(xfunc_error_retval);
5833 /* Shell is non-interactive at first. We need to call
5834 * block_signals(0) if we are going to execute "sh <script>",
5835 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5836 * If we later decide that we are interactive, we run block_signals(0)
5837 * (or re-run block_signals(1) if we ran block_signals(0) before)
5838 * in order to intercept (more) signals.
5842 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5844 opt = getopt(argc, argv, "c:xins"
5854 G.root_pid = getpid();
5855 G.global_argv = argv + optind;
5856 if (!argv[optind]) {
5857 /* -c 'script' (no params): prevent empty $0 */
5858 *--G.global_argv = argv[0];
5860 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5861 G.global_argc = argc - optind;
5862 block_signals(0); /* 0: called 1st time */
5863 parse_and_run_string(optarg);
5866 /* Well, we cannot just declare interactiveness,
5867 * we have to have some stuff (ctty, etc) */
5868 /* G_interactive_fd++; */
5871 /* "-s" means "read from stdin", but this is how we always
5872 * operate, so simply do nothing here. */
5875 case '<': /* "big heredoc" support */
5876 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5879 G.root_pid = bb_strtou(optarg, &optarg, 16);
5881 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5883 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5884 # if ENABLE_HUSH_LOOPS
5886 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5891 set_local_var(xstrdup(optarg), 0, opt == 'R');
5896 if (!set_mode('-', opt))
5900 fprintf(stderr, "Usage: sh [FILE]...\n"
5901 " or: sh -c command [args]...\n\n");
5907 } /* option parsing loop */
5910 G.root_pid = getpid();
5912 /* If we are login shell... */
5913 if (argv[0] && argv[0][0] == '-') {
5915 /* XXX what should argv be while sourcing /etc/profile? */
5916 debug_printf("sourcing /etc/profile\n");
5917 input = fopen_for_read("/etc/profile");
5918 if (input != NULL) {
5919 close_on_exec_on(fileno(input));
5920 block_signals(0); /* 0: called 1st time */
5921 signal_mask_is_inited = 1;
5922 parse_and_run_file(input);
5925 /* bash: after sourcing /etc/profile,
5926 * tries to source (in the given order):
5927 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5928 * stopping of first found. --noprofile turns this off.
5929 * bash also sources ~/.bash_logout on exit.
5930 * If called as sh, skips .bash_XXX files.
5937 * "bash <script>" (which is never interactive (unless -i?))
5938 * sources $BASH_ENV here (without scanning $PATH).
5939 * If called as sh, does the same but with $ENV.
5941 debug_printf("running script '%s'\n", argv[optind]);
5942 G.global_argv = argv + optind;
5943 G.global_argc = argc - optind;
5944 input = xfopen_for_read(argv[optind]);
5945 close_on_exec_on(fileno(input));
5946 if (!signal_mask_is_inited)
5947 block_signals(0); /* 0: called 1st time */
5948 parse_and_run_file(input);
5949 #if ENABLE_FEATURE_CLEAN_UP
5955 /* Up to here, shell was non-interactive. Now it may become one.
5956 * NB: don't forget to (re)run block_signals(0/1) as needed.
5959 /* A shell is interactive if the '-i' flag was given, or if all of
5960 * the following conditions are met:
5962 * no arguments remaining or the -s flag given
5963 * standard input is a terminal
5964 * standard output is a terminal
5965 * Refer to Posix.2, the description of the 'sh' utility.
5968 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5969 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5970 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5971 //TODO: "interactive" and "have job control" are two different things.
5972 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5973 //should stay on! Currently, we mix these into one.
5974 if (G.saved_tty_pgrp >= 0) {
5975 /* try to dup stdin to high fd#, >= 255 */
5976 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5977 if (G_interactive_fd < 0) {
5978 /* try to dup to any fd */
5979 G_interactive_fd = dup(STDIN_FILENO);
5980 if (G_interactive_fd < 0)
5982 G_interactive_fd = 0;
5984 // TODO: track & disallow any attempts of user
5985 // to (inadvertently) close/redirect it
5988 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5989 if (G_interactive_fd) {
5992 /* We are indeed interactive shell, and we will perform
5993 * job control. Setting up for that. */
5995 close_on_exec_on(G_interactive_fd);
5996 /* If we were run as 'hush &', sleep until we are
5997 * in the foreground (tty pgrp == our pgrp).
5998 * If we get started under a job aware app (like bash),
5999 * make sure we are now in charge so we don't fight over
6000 * who gets the foreground */
6002 shell_pgrp = getpgrp();
6003 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6004 if (G.saved_tty_pgrp == shell_pgrp)
6006 /* send TTIN to ourself (should stop us) */
6007 kill(- shell_pgrp, SIGTTIN);
6009 /* Block some signals */
6010 block_signals(signal_mask_is_inited);
6011 /* Set other signals to restore saved_tty_pgrp */
6012 set_fatal_handlers();
6013 /* Put ourselves in our own process group */
6014 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6015 /* Grab control of the terminal */
6016 tcsetpgrp(G_interactive_fd, getpid());
6017 /* -1 is special - makes xfuncs longjmp, not exit
6018 * (we reset die_sleep = 0 whereever we [v]fork) */
6019 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6020 } else if (!signal_mask_is_inited) {
6021 block_signals(0); /* 0: called 1st time */
6022 } /* else: block_signals(0) was done before */
6023 #elif ENABLE_HUSH_INTERACTIVE
6024 /* No job control compiled in, only prompt/line editing */
6025 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6026 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6027 if (G_interactive_fd < 0) {
6028 /* try to dup to any fd */
6029 G_interactive_fd = dup(STDIN_FILENO);
6030 if (G_interactive_fd < 0)
6032 G_interactive_fd = 0;
6035 if (G_interactive_fd) {
6036 close_on_exec_on(G_interactive_fd);
6037 block_signals(signal_mask_is_inited);
6038 } else if (!signal_mask_is_inited) {
6042 /* We have interactiveness code disabled */
6043 if (!signal_mask_is_inited) {
6048 * if interactive but not a login shell, sources ~/.bashrc
6049 * (--norc turns this off, --rcfile <file> overrides)
6052 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6053 printf("\n\n%s hush - the humble shell\n", bb_banner);
6054 printf("Enter 'help' for a list of built-in commands.\n\n");
6057 parse_and_run_file(stdin);
6060 #if ENABLE_FEATURE_CLEAN_UP
6061 if (G.cwd != bb_msg_unknown)
6063 cur_var = G.top_var->next;
6065 struct variable *tmp = cur_var;
6066 if (!cur_var->max_len)
6067 free(cur_var->varstr);
6068 cur_var = cur_var->next;
6072 hush_exit(G.last_exitcode);
6077 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6078 int lash_main(int argc, char **argv)
6080 //bb_error_msg("lash is deprecated, please use hush instead");
6081 return hush_main(argc, argv);
6089 static int builtin_trap(char **argv)
6096 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6100 /* No args: print all trapped. This isn't 100% correct as we
6101 * should be escaping the cmd so that it can be pasted back in
6103 for (i = 0; i < NSIG; ++i)
6105 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
6106 return EXIT_SUCCESS;
6111 /* If first arg is decimal: reset all specified signals */
6112 sig = bb_strtou(*argv, NULL, 10);
6118 sig = get_signum(*argv++);
6119 if (sig < 0 || sig >= NSIG) {
6121 /* Mimic bash message exactly */
6122 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
6127 G.traps[sig] = xstrdup(new_cmd);
6129 debug_printf("trap: setting SIG%s (%i) to '%s'",
6130 get_signame(sig), sig, G.traps[sig]);
6132 /* There is no signal for 0 (EXIT) */
6137 sigaddset(&G.blocked_set, sig);
6139 /* There was a trap handler, we are removing it
6140 * (if sig has non-DFL handling,
6141 * we don't need to do anything) */
6142 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6144 sigdelset(&G.blocked_set, sig);
6146 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6151 /* First arg is "-": reset all specified to default */
6152 /* First arg is "": ignore all specified */
6153 /* Everything else: execute first arg upon signal */
6155 bb_error_msg("trap: invalid arguments");
6156 return EXIT_FAILURE;
6158 if (NOT_LONE_DASH(*argv))
6164 static int builtin_true(char **argv UNUSED_PARAM)
6169 static int builtin_test(char **argv)
6176 return test_main(argc, argv - argc);
6179 static int builtin_echo(char **argv)
6186 return echo_main(argc, argv - argc);
6189 static int builtin_eval(char **argv)
6191 int rcode = EXIT_SUCCESS;
6194 char *str = expand_strvec_to_string(argv);
6196 * eval "echo Hi; done" ("done" is syntax error):
6197 * "echo Hi" will not execute too.
6199 parse_and_run_string(str);
6201 rcode = G.last_exitcode;
6206 static int builtin_cd(char **argv)
6208 const char *newdir = argv[1];
6209 if (newdir == NULL) {
6210 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6211 * bash says "bash: cd: HOME not set" and does nothing
6214 newdir = getenv("HOME") ? : "/";
6216 if (chdir(newdir)) {
6217 /* Mimic bash message exactly */
6218 bb_perror_msg("cd: %s", newdir);
6219 return EXIT_FAILURE;
6222 return EXIT_SUCCESS;
6225 static int builtin_exec(char **argv)
6227 if (*++argv == NULL)
6228 return EXIT_SUCCESS; /* bash does this */
6233 // FIXME: if exec fails, bash does NOT exit! We do...
6234 pseudo_exec_argv(&dummy, argv, 0, NULL);
6239 static int builtin_exit(char **argv)
6241 debug_printf_exec("%s()\n", __func__);
6242 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6243 //puts("exit"); /* bash does it */
6244 // TODO: warn if we have background jobs: "There are stopped jobs"
6245 // On second consecutive 'exit', exit anyway.
6246 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6248 /* note: EXIT trap is run by hush_exit */
6249 if (*++argv == NULL)
6250 hush_exit(G.last_exitcode);
6251 /* mimic bash: exit 123abc == exit 255 + error msg */
6252 xfunc_error_retval = 255;
6253 /* bash: exit -2 == exit 254, no error msg */
6254 hush_exit(xatoi(*argv) & 0xff);
6257 static int builtin_export(char **argv)
6259 if (*++argv == NULL) {
6266 /* ash emits: export VAR='VAL'
6267 * bash: declare -x VAR="VAL"
6268 * we follow ash example */
6269 const char *s = *e++;
6270 const char *p = strchr(s, '=');
6272 if (!p) /* wtf? take next variable */
6275 printf("export %.*s", (int)(p - s) + 1, s);
6279 p = strchrnul(s, '\'');
6281 printf("'%.*s'", (int)(p - s), s);
6286 /* s points to '; print ''...'''" */
6288 do putchar('\''); while (*++s == '\'');
6296 return EXIT_SUCCESS;
6303 value = strchr(name, '=');
6305 /* They are exporting something without a =VALUE */
6306 struct variable *var;
6308 var = get_local_var(name);
6310 var->flg_export = 1;
6311 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6312 putenv(var->varstr);
6314 /* bash does not return an error when trying to export
6315 * an undefined variable. Do likewise. */
6318 set_local_var(xstrdup(name), 1, 0);
6321 return EXIT_SUCCESS;
6325 /* built-in 'fg' and 'bg' handler */
6326 static int builtin_fg_bg(char **argv)
6331 if (!G_interactive_fd)
6332 return EXIT_FAILURE;
6333 /* If they gave us no args, assume they want the last backgrounded task */
6335 for (pi = G.job_list; pi; pi = pi->next) {
6336 if (pi->jobid == G.last_jobid) {
6340 bb_error_msg("%s: no current job", argv[0]);
6341 return EXIT_FAILURE;
6343 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6344 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6345 return EXIT_FAILURE;
6347 for (pi = G.job_list; pi; pi = pi->next) {
6348 if (pi->jobid == jobnum) {
6352 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6353 return EXIT_FAILURE;
6355 // TODO: bash prints a string representation
6356 // of job being foregrounded (like "sleep 1 | cat")
6357 if (argv[0][0] == 'f') {
6358 /* Put the job into the foreground. */
6359 tcsetpgrp(G_interactive_fd, pi->pgrp);
6362 /* Restart the processes in the job */
6363 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6364 for (i = 0; i < pi->num_cmds; i++) {
6365 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6366 pi->cmds[i].is_stopped = 0;
6368 pi->stopped_cmds = 0;
6370 i = kill(- pi->pgrp, SIGCONT);
6372 if (errno == ESRCH) {
6373 delete_finished_bg_job(pi);
6374 return EXIT_SUCCESS;
6376 bb_perror_msg("kill (SIGCONT)");
6379 if (argv[0][0] == 'f') {
6381 return checkjobs_and_fg_shell(pi);
6383 return EXIT_SUCCESS;
6387 #if ENABLE_HUSH_HELP
6388 static int builtin_help(char **argv UNUSED_PARAM)
6390 const struct built_in_command *x;
6393 "Built-in commands:\n"
6394 "------------------\n");
6395 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6396 printf("%s\t%s\n", x->cmd, x->descr);
6399 return EXIT_SUCCESS;
6404 static int builtin_jobs(char **argv UNUSED_PARAM)
6407 const char *status_string;
6409 for (job = G.job_list; job; job = job->next) {
6410 if (job->alive_cmds == job->stopped_cmds)
6411 status_string = "Stopped";
6413 status_string = "Running";
6415 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6417 return EXIT_SUCCESS;
6422 static int builtin_memleak(char **argv UNUSED_PARAM)
6427 /* Crude attempt to find where "free memory" starts,
6428 * sans fragmentation. */
6430 l = (unsigned long)p;
6433 if (l < (unsigned long)p) l = (unsigned long)p;
6436 if (!G.memleak_value)
6437 G.memleak_value = l;
6439 l -= G.memleak_value;
6446 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6451 static int builtin_pwd(char **argv UNUSED_PARAM)
6454 return EXIT_SUCCESS;
6457 static int builtin_read(char **argv)
6460 const char *name = "REPLY";
6464 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6465 * and _after_ that_ it will complain */
6466 if (!is_well_formed_var_name(name, '\0')) {
6467 /* Mimic bash message */
6468 bb_error_msg("read: '%s': not a valid identifier", name);
6473 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6475 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6476 return set_local_var(string, 0, 0);
6479 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6480 * built-in 'set' handler
6482 * set [-abCefhmnuvx] [-o option] [argument...]
6483 * set [+abCefhmnuvx] [+o option] [argument...]
6484 * set -- [argument...]
6487 * Implementations shall support the options in both their hyphen and
6488 * plus-sign forms. These options can also be specified as options to sh.
6490 * Write out all variables and their values: set
6491 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6492 * Turn on the -x and -v options: set -xv
6493 * Unset all positional parameters: set --
6494 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6495 * Set the positional parameters to the expansion of x, even if x expands
6496 * with a leading '-' or '+': set -- $x
6498 * So far, we only support "set -- [argument...]" and some of the short names.
6500 static int builtin_set(char **argv)
6503 char **pp, **g_argv;
6504 char *arg = *++argv;
6508 for (e = G.top_var; e; e = e->next)
6510 return EXIT_SUCCESS;
6514 if (!strcmp(arg, "--")) {
6518 if (arg[0] != '+' && arg[0] != '-')
6520 for (n = 1; arg[n]; ++n)
6521 if (set_mode(arg[0], arg[n]))
6523 } while ((arg = *++argv) != NULL);
6524 /* Now argv[0] is 1st argument */
6527 return EXIT_SUCCESS;
6530 /* NB: G.global_argv[0] ($0) is never freed/changed */
6531 g_argv = G.global_argv;
6532 if (G.global_args_malloced) {
6538 G.global_args_malloced = 1;
6539 pp = xzalloc(sizeof(pp[0]) * 2);
6540 pp[0] = g_argv[0]; /* retain $0 */
6543 /* This realloc's G.global_argv */
6544 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6551 return EXIT_SUCCESS;
6553 /* Nothing known, so abort */
6555 bb_error_msg("set: %s: invalid option", arg);
6556 return EXIT_FAILURE;
6559 static int builtin_shift(char **argv)
6565 if (n >= 0 && n < G.global_argc) {
6566 if (G.global_args_malloced) {
6569 free(G.global_argv[m++]);
6572 memmove(&G.global_argv[1], &G.global_argv[n+1],
6573 G.global_argc * sizeof(G.global_argv[0]));
6574 return EXIT_SUCCESS;
6576 return EXIT_FAILURE;
6579 static int builtin_source(char **argv)
6583 if (*++argv == NULL)
6584 return EXIT_FAILURE;
6586 /* XXX search through $PATH is missing */
6587 input = fopen_or_warn(*argv, "r");
6589 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6590 return EXIT_FAILURE;
6592 close_on_exec_on(fileno(input));
6594 /* Now run the file */
6596 /* XXX argv and argc are broken; need to save old G.global_argv
6597 * (pointer only is OK!) on this stack frame,
6598 * set G.global_argv=argv+1, recurse, and restore. */
6599 parse_and_run_file(input);
6601 return G.last_exitcode;
6604 static int builtin_umask(char **argv)
6607 const char *arg = argv[1];
6609 //TODO: umask may take chmod-like symbolic masks
6610 new_umask = bb_strtou(arg, NULL, 8);
6612 //Message? bash examples:
6613 //bash: umask: 'q': invalid symbolic mode operator
6614 //bash: umask: 999: octal number out of range
6615 return EXIT_FAILURE;
6618 new_umask = umask(0);
6619 printf("%.3o\n", (unsigned) new_umask);
6620 /* fall through and restore new_umask which we set to 0 */
6623 return EXIT_SUCCESS;
6626 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6627 static int builtin_unset(char **argv)
6633 return EXIT_SUCCESS;
6636 if (argv[0][0] == '-') {
6637 switch (argv[0][1]) {
6643 bb_error_msg("unset: %s: invalid option", *argv);
6644 return EXIT_FAILURE;
6646 //TODO: disallow "unset -vf ..." too
6653 if (unset_local_var(*argv)) {
6654 /* unset <nonexistent_var> doesn't fail.
6655 * Error is when one tries to unset RO var.
6656 * Message was printed by unset_local_var. */
6660 //#if ENABLE_HUSH_FUNCTIONS
6662 // unset_local_func(*argv);
6670 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6671 static int builtin_wait(char **argv)
6673 int ret = EXIT_SUCCESS;
6676 if (*++argv == NULL) {
6677 /* Don't care about wait results */
6678 /* Note 1: must wait until there are no more children */
6679 /* Note 2: must be interruptible */
6681 * $ sleep 3 & sleep 6 & wait
6686 * $ sleep 3 & sleep 6 & wait
6690 * ^C <-- after ~4 sec from keyboard
6693 sigaddset(&G.blocked_set, SIGCHLD);
6694 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6697 if (errno == ECHILD)
6699 /* Wait for SIGCHLD or any other signal of interest */
6700 /* sigtimedwait with infinite timeout: */
6701 sig = sigwaitinfo(&G.blocked_set, NULL);
6703 sig = check_and_run_traps(sig);
6704 if (sig && sig != SIGCHLD) { /* see note 2 */
6710 sigdelset(&G.blocked_set, SIGCHLD);
6711 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6715 /* This is probably buggy wrt interruptible-ness */
6717 pid_t pid = bb_strtou(*argv, NULL, 10);
6719 /* mimic bash message */
6720 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6721 return EXIT_FAILURE;
6723 if (waitpid(pid, &status, 0) == pid) {
6724 if (WIFSIGNALED(status))
6725 ret = 128 + WTERMSIG(status);
6726 else if (WIFEXITED(status))
6727 ret = WEXITSTATUS(status);
6731 bb_perror_msg("wait %s", *argv);
6740 #if ENABLE_HUSH_LOOPS
6741 static int builtin_break(char **argv)
6743 if (G.depth_of_loop == 0) {
6744 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6745 return EXIT_SUCCESS; /* bash compat */
6747 G.flag_break_continue++; /* BC_BREAK = 1 */
6748 G.depth_break_continue = 1;
6750 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6751 if (errno || !G.depth_break_continue || argv[2]) {
6752 bb_error_msg("%s: bad arguments", argv[0]);
6753 G.flag_break_continue = BC_BREAK;
6754 G.depth_break_continue = UINT_MAX;
6757 if (G.depth_of_loop < G.depth_break_continue)
6758 G.depth_break_continue = G.depth_of_loop;
6759 return EXIT_SUCCESS;
6762 static int builtin_continue(char **argv)
6764 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6765 return builtin_break(argv);