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.
68 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
69 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
70 //#include "applet_tables.h" doesn't work
72 /* #include <dmalloc.h> */
79 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
82 #ifdef WANT_TO_TEST_NOMMU
87 # define USE_FOR_NOMMU(...) __VA_ARGS__
88 # define USE_FOR_MMU(...)
91 #if defined SINGLE_APPLET_MAIN
92 /* STANDALONE does not make sense, and won't compile */
93 #undef CONFIG_FEATURE_SH_STANDALONE
94 #undef ENABLE_FEATURE_SH_STANDALONE
95 #undef USE_FEATURE_SH_STANDALONE
96 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
97 #define ENABLE_FEATURE_SH_STANDALONE 0
98 #define USE_FEATURE_SH_STANDALONE(...)
99 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
102 #if !ENABLE_HUSH_INTERACTIVE
103 #undef ENABLE_FEATURE_EDITING
104 #define ENABLE_FEATURE_EDITING 0
105 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
106 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
109 /* Do we support ANY keywords? */
110 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
111 #define HAS_KEYWORDS 1
112 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
113 #define IF_HAS_NO_KEYWORDS(...)
115 #define HAS_KEYWORDS 0
116 #define IF_HAS_KEYWORDS(...)
117 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
120 /* Enable/disable sanity checks. Ok to enable in production,
121 * only adds a bit of bloat.
122 * Keeping unconditionally on for now.
126 #define ENABLE_HUSH_FUNCTIONS 0
129 /* If you comment out one of these below, it will be #defined later
130 * to perform debug printfs to stderr: */
131 #define debug_printf(...) do {} while (0)
132 /* Finer-grained debug switches */
133 #define debug_printf_parse(...) do {} while (0)
134 #define debug_print_tree(a, b) do {} while (0)
135 #define debug_printf_exec(...) do {} while (0)
136 #define debug_printf_env(...) do {} while (0)
137 #define debug_printf_jobs(...) do {} while (0)
138 #define debug_printf_expand(...) do {} while (0)
139 #define debug_printf_glob(...) do {} while (0)
140 #define debug_printf_list(...) do {} while (0)
141 #define debug_printf_subst(...) do {} while (0)
142 #define debug_printf_clean(...) do {} while (0)
145 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
148 #ifndef debug_printf_parse
149 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
152 #ifndef debug_printf_exec
153 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
156 #ifndef debug_printf_env
157 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
160 #ifndef debug_printf_jobs
161 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
167 #ifndef debug_printf_expand
168 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
169 #define DEBUG_EXPAND 1
171 #define DEBUG_EXPAND 0
174 #ifndef debug_printf_glob
175 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
181 #ifndef debug_printf_list
182 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
185 #ifndef debug_printf_subst
186 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
189 #ifndef debug_printf_clean
190 /* broken, of course, but OK for testing */
191 static const char *indenter(int i)
193 static const char blanks[] ALIGN1 =
195 return &blanks[sizeof(blanks) - i - 1];
197 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
198 #define DEBUG_CLEAN 1
200 #define DEBUG_CLEAN 0
204 static void debug_print_strings(const char *prefix, char **vv)
206 fprintf(stderr, "%s:\n", prefix);
208 fprintf(stderr, " '%s'\n", *vv++);
211 #define debug_print_strings(prefix, vv) ((void)0)
215 * Leak hunting. Use hush_leaktool.sh for post-processing.
217 #ifdef FOR_HUSH_LEAKTOOL
218 static void *xxmalloc(int lineno, size_t size)
220 void *ptr = xmalloc((size + 0xff) & ~0xff);
221 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
224 static void *xxrealloc(int lineno, void *ptr, size_t size)
226 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
227 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
230 static char *xxstrdup(int lineno, const char *str)
232 char *ptr = xstrdup(str);
233 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
236 static void xxfree(void *ptr)
238 fdprintf(2, "free %p\n", ptr);
241 #define xmalloc(s) xxmalloc(__LINE__, s)
242 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
243 #define xstrdup(s) xxstrdup(__LINE__, s)
244 #define free(p) xxfree(p)
248 #define ERR_PTR ((void*)(long)1)
250 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
252 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
254 #define SPECIAL_VAR_SYMBOL 3
256 /* The descrip member of this structure is only used to make
257 * debugging output pretty */
258 static const struct {
260 signed char default_fd;
264 { O_RDONLY, 0, "<" },
265 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
266 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
267 { O_RDONLY, 0, "<<" },
268 { O_CREAT|O_RDWR, 1, "<>" },
269 /* Should not be needed. Bogus default_fd helps in debugging */
270 /* { O_RDONLY, 77, "<<" }, */
273 typedef enum reserved_style {
282 #if ENABLE_HUSH_LOOPS
289 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
294 /* two pseudo-keywords support contrived "case" syntax: */
295 RES_MATCH , /* "word)" */
296 RES_CASEI , /* "this command is inside CASE" */
303 typedef struct o_string {
305 int length; /* position where data is appended */
307 /* Protect newly added chars against globbing
308 * (by prepending \ to *, ?, [, \) */
311 /* At least some part of the string was inside '' or "",
312 * possibly empty one: word"", wo''rd etc. */
314 smallint has_empty_slot;
315 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
318 MAYBE_ASSIGNMENT = 0,
319 DEFINITELY_ASSIGNMENT = 1,
321 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
323 /* Used for initialization: o_string foo = NULL_O_STRING; */
324 #define NULL_O_STRING { NULL }
326 /* I can almost use ordinary FILE*. Is open_memstream() universally
327 * available? Where is it documented? */
328 typedef struct in_str {
330 /* eof_flag=1: last char in ->p is really an EOF */
331 char eof_flag; /* meaningless if ->p == NULL */
333 #if ENABLE_HUSH_INTERACTIVE
335 smallint promptmode; /* 0: PS1, 1: PS2 */
338 int (*get) (struct in_str *);
339 int (*peek) (struct in_str *);
341 #define i_getch(input) ((input)->get(input))
342 #define i_peek(input) ((input)->peek(input))
344 struct redir_struct {
345 struct redir_struct *next;
346 char *rd_filename; /* filename */
347 int rd_fd; /* fd to redirect */
348 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
350 smallint rd_type; /* (enum redir_type) */
351 /* note: for heredocs, rd_filename contains heredoc delimiter,
352 * and subsequently heredoc itself; and rd_dup is a bitmask:
353 * 1: do we need to trim leading tabs?
354 * 2: is heredoc quoted (<<'dleim' syntax) ?
357 typedef enum redir_type {
358 REDIRECT_INVALID = 0,
360 REDIRECT_OVERWRITE = 2,
362 REDIRECT_HEREDOC = 4,
364 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
366 HEREDOC_SKIPTABS = 1,
372 pid_t pid; /* 0 if exited */
373 int assignment_cnt; /* how many argv[i] are assignments? */
374 smallint is_stopped; /* is the command currently running? */
375 smallint grp_type; /* GRP_xxx */
376 struct pipe *group; /* if non-NULL, this "command" is { list },
377 * ( list ), or a compound statement */
379 char *group_as_string;
381 char **argv; /* command name and arguments */
382 struct redir_struct *redirects; /* I/O redirections */
384 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
385 * and on execution these are substituted with their values.
386 * Substitution can make _several_ words out of one argv[n]!
387 * Example: argv[0]=='.^C*^C.' here: echo .$*.
388 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
391 #define GRP_SUBSHELL 1
392 #if ENABLE_HUSH_FUNCTIONS
393 #define GRP_FUNCTION 2
398 int num_cmds; /* total number of commands in job */
399 int alive_cmds; /* number of commands running (not exited) */
400 int stopped_cmds; /* number of commands alive, but stopped */
402 int jobid; /* job number */
403 pid_t pgrp; /* process group ID for the job */
404 char *cmdtext; /* name of job */
406 struct command *cmds; /* array of commands in pipe */
407 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
408 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
409 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
411 typedef enum pipe_style {
418 /* This holds pointers to the various results of parsing */
419 struct parse_context {
420 /* linked list of pipes */
421 struct pipe *list_head;
422 /* last pipe (being constructed right now) */
424 /* last command in pipe (being constructed right now) */
425 struct command *command;
426 /* last redirect in command->redirects list */
427 struct redir_struct *pending_redirect;
433 smallint ctx_inverted; /* "! cmd | cmd" */
435 smallint ctx_dsemicolon; /* ";;" seen */
437 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
439 /* group we are enclosed in:
440 * example: "if pipe1; pipe2; then pipe3; fi"
441 * when we see "if" or "then", we malloc and copy current context,
442 * and make ->stack point to it. then we parse pipeN.
443 * when closing "then" / fi" / whatever is found,
444 * we move list_head into ->stack->command->group,
445 * copy ->stack into current context, and delete ->stack.
446 * (parsing of { list } and ( list ) doesn't use this method)
448 struct parse_context *stack;
452 /* On program start, environ points to initial environment.
453 * putenv adds new pointers into it, unsetenv removes them.
454 * Neither of these (de)allocates the strings.
455 * setenv allocates new strings in malloc space and does putenv,
456 * and thus setenv is unusable (leaky) for shell's purposes */
457 #define setenv(...) setenv_is_leaky_dont_use()
459 struct variable *next;
460 char *varstr; /* points to "name=" portion */
461 int max_len; /* if > 0, name is part of initial env; else name is malloced */
462 smallint flg_export; /* putenv should be done on this var */
463 smallint flg_read_only;
472 /* "Globals" within this file */
473 /* Sorted roughly by size (smaller offsets == smaller code) */
475 #if ENABLE_HUSH_INTERACTIVE
476 /* 'interactive_fd' is a fd# open to ctty, if we have one
477 * _AND_ if we decided to act interactively */
481 #define G_interactive_fd (G.interactive_fd)
483 #define G_interactive_fd 0
485 #if ENABLE_FEATURE_EDITING
486 line_input_t *line_input_state;
492 pid_t saved_tty_pgrp;
494 struct pipe *job_list;
495 struct pipe *toplevel_list;
496 //// smallint ctrl_z_flag;
498 smallint flag_SIGINT;
499 #if ENABLE_HUSH_LOOPS
500 smallint flag_break_continue;
503 /* These four support $?, $#, and $1 */
504 smalluint last_exitcode;
505 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
506 smalluint global_args_malloced;
507 /* how many non-NULL argv's we have. NB: $# + 1 */
511 char *argv0_for_re_execing;
512 char **argv_from_re_execing;
514 #if ENABLE_HUSH_LOOPS
515 unsigned depth_break_continue;
516 unsigned depth_of_loop;
520 struct variable *top_var; /* = &G.shell_ver (set in main()) */
521 struct variable shell_ver;
522 /* Signal and trap handling */
523 // unsigned count_SIGCHLD;
524 // unsigned handled_SIGCHLD;
525 /* which signals have non-DFL handler (even with no traps set)? */
526 unsigned non_DFL_mask;
527 char **traps; /* char *traps[NSIG] */
528 sigset_t blocked_set;
529 sigset_t inherited_set;
531 unsigned long memleak_value;
533 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
534 #if ENABLE_FEATURE_SH_STANDALONE
535 struct nofork_save_area nofork_save;
538 sigjmp_buf toplevel_jb;
541 #define G (*ptr_to_globals)
542 /* Not #defining name to G.name - this quickly gets unwieldy
543 * (too many defines). Also, I actually prefer to see when a variable
544 * is global, thus "G." prefix is a useful hint */
545 #define INIT_G() do { \
546 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
550 /* Function prototypes for builtins */
551 static int builtin_cd(char **argv);
552 static int builtin_echo(char **argv);
553 static int builtin_eval(char **argv);
554 static int builtin_exec(char **argv);
555 static int builtin_exit(char **argv);
556 static int builtin_export(char **argv);
558 static int builtin_fg_bg(char **argv);
559 static int builtin_jobs(char **argv);
562 static int builtin_help(char **argv);
565 static int builtin_memleak(char **argv);
567 static int builtin_pwd(char **argv);
568 static int builtin_read(char **argv);
569 static int builtin_set(char **argv);
570 static int builtin_shift(char **argv);
571 static int builtin_source(char **argv);
572 static int builtin_test(char **argv);
573 static int builtin_trap(char **argv);
574 static int builtin_true(char **argv);
575 static int builtin_umask(char **argv);
576 static int builtin_unset(char **argv);
577 static int builtin_wait(char **argv);
578 #if ENABLE_HUSH_LOOPS
579 static int builtin_break(char **argv);
580 static int builtin_continue(char **argv);
583 /* Table of built-in functions. They can be forked or not, depending on
584 * context: within pipes, they fork. As simple commands, they do not.
585 * When used in non-forking context, they can change global variables
586 * in the parent shell process. If forked, of course they cannot.
587 * For example, 'unset foo | whatever' will parse and run, but foo will
588 * still be set at the end. */
589 struct built_in_command {
591 int (*function)(char **argv);
594 #define BLTIN(cmd, func, help) { cmd, func, help }
596 #define BLTIN(cmd, func, help) { cmd, func }
600 /* For now, echo and test are unconditionally enabled.
601 * Maybe make it configurable? */
602 static const struct built_in_command bltins[] = {
603 BLTIN("." , builtin_source , "Run commands in a file"),
604 BLTIN(":" , builtin_true , "No-op"),
605 BLTIN("[" , builtin_test , "Test condition"),
607 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
609 #if ENABLE_HUSH_LOOPS
610 BLTIN("break" , builtin_break , "Exit from a loop"),
612 BLTIN("cd" , builtin_cd , "Change directory"),
613 #if ENABLE_HUSH_LOOPS
614 BLTIN("continue", builtin_continue, "Start new loop iteration"),
616 BLTIN("echo" , builtin_echo , "Write to stdout"),
617 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
618 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
619 BLTIN("exit" , builtin_exit , "Exit"),
620 BLTIN("export" , builtin_export , "Set environment variable"),
622 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
625 BLTIN("help" , builtin_help , "List shell built-in commands"),
628 BLTIN("jobs" , builtin_jobs , "List active jobs"),
631 BLTIN("memleak" , builtin_memleak , "Debug tool"),
633 BLTIN("pwd" , builtin_pwd , "Print current directory"),
634 BLTIN("read" , builtin_read , "Input environment variable"),
635 // BLTIN("return" , builtin_return , "Return from a function"),
636 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
637 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
638 BLTIN("test" , builtin_test , "Test condition"),
639 BLTIN("trap" , builtin_trap , "Trap signals"),
640 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
641 BLTIN("umask" , builtin_umask , "Set file creation mask"),
642 BLTIN("unset" , builtin_unset , "Unset environment variable"),
643 BLTIN("wait" , builtin_wait , "Wait for process"),
647 static void maybe_die(const char *notice, const char *msg)
649 /* Was using fancy stuff:
650 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
651 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
652 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
653 #if ENABLE_HUSH_INTERACTIVE
654 if (G_interactive_fd)
657 fp(msg ? "%s: %s" : notice, notice, msg);
660 #define syntax(msg) maybe_die("syntax error", msg);
662 /* Debug -- trick gcc to expand __LINE__ and convert to string */
663 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
664 #define _syntax(msg, line) __syntax(msg, line)
665 #define syntax(msg) _syntax(msg, __LINE__)
669 static int glob_needed(const char *s)
674 if (*s == '*' || *s == '[' || *s == '?')
681 static int is_assignment(const char *s)
683 if (!s || !(isalpha(*s) || *s == '_'))
686 while (isalnum(*s) || *s == '_')
691 /* Replace each \x with x in place, return ptr past NUL. */
692 static char *unbackslash(char *src)
698 if ((*dst++ = *src++) == '\0')
704 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
725 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
726 v[count1 + count2] = NULL;
729 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
733 static char **add_string_to_strings(char **strings, char *add)
738 return add_strings_to_strings(strings, v, /*dup:*/ 0);
741 static void putenv_all(char **strings)
746 debug_printf_env("putenv '%s'\n", *strings);
751 static char **putenv_all_and_save_old(char **strings)
761 eq = strchr(*strings, '=');
764 v = getenv(*strings);
767 /* v points to VAL in VAR=VAL, go back to VAR */
768 v -= (eq - *strings) + 1;
769 old = add_string_to_strings(old, v);
778 static void free_strings_and_unsetenv(char **strings, int unset)
788 debug_printf_env("unsetenv '%s'\n", *v);
796 static void free_strings(char **strings)
798 free_strings_and_unsetenv(strings, 0);
802 /* Basic theory of signal handling in shell
803 * ========================================
804 * This does not describe what hush does, rather, it is current understanding
805 * what it _should_ do. If it doesn't, it's a bug.
806 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
808 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
809 * is finished or backgrounded. It is the same in interactive and
810 * non-interactive shells, and is the same regardless of whether
811 * a user trap handler is installed or a shell special one is in effect.
812 * ^C or ^Z from keyboard seem to execute "at once" because it usually
813 * backgrounds (i.e. stops) or kills all members of currently running
816 * Wait builtin in interruptible by signals for which user trap is set
817 * or by SIGINT in interactive shell.
819 * Trap handlers will execute even within trap handlers. (right?)
821 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
823 * If job control is off, backgrounded commands ("cmd &")
824 * have SIGINT, SIGQUIT set to SIG_IGN.
826 * Commands run in command substitution ("`cmd`")
827 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
829 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
830 * by the shell from its parent.
832 * Siganls which differ from SIG_DFL action
833 * (note: child (i.e., [v]forked) shell is not an interactive shell):
836 * SIGTERM (interactive): ignore
837 * SIGHUP (interactive):
838 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
839 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
840 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
841 * that all pipe members are stopped) (right?)
842 * SIGINT (interactive): wait for last pipe, ignore the rest
843 * of the command line, show prompt. NB: ^C does not send SIGINT
844 * to interactive shell while shell is waiting for a pipe,
845 * since shell is bg'ed (is not in foreground process group).
846 * (check/expand this)
847 * Example 1: this waits 5 sec, but does not execute ls:
848 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
849 * Example 2: this does not wait and does not execute ls:
850 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
851 * Example 3: this does not wait 5 sec, but executes ls:
852 * "sleep 5; ls -l" + press ^C
854 * (What happens to signals which are IGN on shell start?)
855 * (What happens with signal mask on shell start?)
857 * Implementation in hush
858 * ======================
859 * We use in-kernel pending signal mask to determine which signals were sent.
860 * We block all signals which we don't want to take action immediately,
861 * i.e. we block all signals which need to have special handling as described
862 * above, and all signals which have traps set.
863 * After each pipe execution, we extract any pending signals via sigtimedwait()
866 * unsigned non_DFL_mask: a mask of such "special" signals
867 * sigset_t blocked_set: current blocked signal set
870 * clear bit in blocked_set unless it is also in non_DFL_mask
871 * "trap 'cmd' SIGxxx":
872 * set bit in blocked_set (even if 'cmd' is '')
873 * after [v]fork, if we plan to be a shell:
874 * nothing for {} child shell (say, "true | { true; true; } | true")
875 * unset all traps if () shell. [TODO]
876 * after [v]fork, if we plan to exec:
877 * POSIX says pending signal mask is cleared in child - no need to clear it.
878 * Restore blocked signal set to one inherited by shell just prior to exec.
880 * Note: as a result, we do not use signal handlers much. The only uses
881 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
882 * and to restore tty pgrp on signal-induced exit.
885 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
887 // G.count_SIGCHLD++;
890 static int check_and_run_traps(int sig)
892 static const struct timespec zero_timespec = { 0, 0 };
893 smalluint save_rcode;
899 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
904 if (G.traps && G.traps[sig]) {
905 if (G.traps[sig][0]) {
906 /* We have user-defined handler */
907 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
908 save_rcode = G.last_exitcode;
911 G.last_exitcode = save_rcode;
912 } /* else: "" trap, ignoring signal */
915 /* not a trap: special action */
918 // G.count_SIGCHLD++;
927 default: /* ignored: */
928 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
937 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
938 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
939 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
940 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
942 /* Restores tty foreground process group, and exits.
943 * May be called as signal handler for fatal signal
944 * (will faithfully resend signal to itself, producing correct exit state)
945 * or called directly with -EXITCODE.
946 * We also call it if xfunc is exiting. */
947 static void sigexit(int sig) NORETURN;
948 static void sigexit(int sig)
950 /* Disable all signals: job control, SIGPIPE, etc. */
951 sigprocmask_allsigs(SIG_BLOCK);
953 /* Careful: we can end up here after [v]fork. Do not restore
954 * tty pgrp then, only top-level shell process does that */
955 if (G_interactive_fd && getpid() == G.root_pid)
956 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
958 /* Not a signal, just exit */
962 kill_myself_with_sig(sig); /* does not return */
966 #define disable_restore_tty_pgrp_on_exit() ((void)0)
967 #define enable_restore_tty_pgrp_on_exit() ((void)0)
971 /* Restores tty foreground process group, and exits. */
972 static void hush_exit(int exitcode) NORETURN;
973 static void hush_exit(int exitcode)
975 if (G.traps && G.traps[0] && G.traps[0][0]) {
976 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
977 //TODO: do we need to prevent recursion?
983 fflush(NULL); /* flush all streams */
984 sigexit(- (exitcode & 0xff));
991 static const char *set_cwd(void)
993 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
994 * we must not try to free(bb_msg_unknown) */
995 if (G.cwd == bb_msg_unknown)
997 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
999 G.cwd = bb_msg_unknown;
1004 /* Get/check local shell variables */
1005 static struct variable *get_local_var(const char *name)
1007 struct variable *cur;
1013 for (cur = G.top_var; cur; cur = cur->next) {
1014 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1020 static const char *get_local_var_value(const char *src)
1022 struct variable *var = get_local_var(src);
1024 return strchr(var->varstr, '=') + 1;
1028 /* str holds "NAME=VAL" and is expected to be malloced.
1029 * We take ownership of it.
1033 * -1: if NAME is set, leave export status alone
1034 * if NAME is not set, do not export
1035 * flg_read_only is set only when we handle -R var=val
1038 #define set_local_var(str, flg_export, flg_read_only) \
1039 set_local_var(str, flg_export)
1041 static int set_local_var(char *str, int flg_export, int flg_read_only)
1043 struct variable *cur;
1047 value = strchr(str, '=');
1048 if (!value) { /* not expected to ever happen? */
1053 name_len = value - str + 1; /* including '=' */
1054 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1056 if (strncmp(cur->varstr, str, name_len) != 0) {
1058 /* Bail out. Note that now cur points
1059 * to last var in linked list */
1065 /* We found an existing var with this name */
1067 if (cur->flg_read_only) {
1071 bb_error_msg("%s: readonly variable", str);
1075 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1076 unsetenv(str); /* just in case */
1078 if (strcmp(cur->varstr, str) == 0) {
1083 if (cur->max_len >= strlen(str)) {
1084 /* This one is from startup env, reuse space */
1085 strcpy(cur->varstr, str);
1088 /* max_len == 0 signifies "malloced" var, which we can
1089 * (and has to) free */
1093 goto set_str_and_exp;
1096 /* Not found - create next variable struct */
1097 cur->next = xzalloc(sizeof(*cur));
1103 cur->flg_read_only = flg_read_only;
1106 if (flg_export == 1)
1107 cur->flg_export = 1;
1108 if (cur->flg_export) {
1109 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1110 return putenv(cur->varstr);
1115 static int unset_local_var(const char *name)
1117 struct variable *cur;
1118 struct variable *prev = prev; /* for gcc */
1122 return EXIT_SUCCESS;
1123 name_len = strlen(name);
1126 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1127 if (cur->flg_read_only) {
1128 bb_error_msg("%s: readonly variable", name);
1129 return EXIT_FAILURE;
1131 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1132 * is ro, and we cannot reach this code on the 1st pass */
1133 prev->next = cur->next;
1134 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1135 bb_unsetenv(cur->varstr);
1139 return EXIT_SUCCESS;
1144 return EXIT_SUCCESS;
1147 #if ENABLE_SH_MATH_SUPPORT
1148 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1149 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1150 static char *endofname(const char *name)
1158 if (!is_in_name(*p))
1164 static void arith_set_local_var(const char *name, const char *val, int flags)
1166 /* arith code doesnt malloc space, so do it for it */
1167 char *var = xasprintf("%s=%s", name, val);
1168 set_local_var(var, flags, 0);
1176 static int static_get(struct in_str *i)
1185 static int static_peek(struct in_str *i)
1190 #if ENABLE_HUSH_INTERACTIVE
1192 static void cmdedit_set_initial_prompt(void)
1194 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1195 G.PS1 = getenv("PS1");
1202 static const char* setup_prompt_string(int promptmode)
1204 const char *prompt_str;
1205 debug_printf("setup_prompt_string %d ", promptmode);
1206 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1207 /* Set up the prompt */
1208 if (promptmode == 0) { /* PS1 */
1210 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1215 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1216 debug_printf("result '%s'\n", prompt_str);
1220 static void get_user_input(struct in_str *i)
1223 const char *prompt_str;
1225 prompt_str = setup_prompt_string(i->promptmode);
1226 #if ENABLE_FEATURE_EDITING
1227 /* Enable command line editing only while a command line
1228 * is actually being read */
1231 /* buglet: SIGINT will not make new prompt to appear _at once_,
1232 * only after <Enter>. (^C will work) */
1233 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1234 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1235 check_and_run_traps(0);
1236 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1237 i->eof_flag = (r < 0);
1238 if (i->eof_flag) { /* EOF/error detected */
1239 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1240 G.user_input_buf[1] = '\0';
1245 fputs(prompt_str, stdout);
1247 G.user_input_buf[0] = r = fgetc(i->file);
1248 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1249 //do we need check_and_run_traps(0)? (maybe only if stdin)
1250 } while (G.flag_SIGINT);
1251 i->eof_flag = (r == EOF);
1253 i->p = G.user_input_buf;
1256 #endif /* INTERACTIVE */
1258 /* This is the magic location that prints prompts
1259 * and gets data back from the user */
1260 static int file_get(struct in_str *i)
1264 /* If there is data waiting, eat it up */
1265 if (i->p && *i->p) {
1266 #if ENABLE_HUSH_INTERACTIVE
1270 if (i->eof_flag && !*i->p)
1272 /* note: ch is never NUL */
1274 /* need to double check i->file because we might be doing something
1275 * more complicated by now, like sourcing or substituting. */
1276 #if ENABLE_HUSH_INTERACTIVE
1277 if (G_interactive_fd && i->promptme && i->file == stdin) {
1280 } while (!*i->p); /* need non-empty line */
1281 i->promptmode = 1; /* PS2 */
1286 do ch = fgetc(i->file); while (ch == '\0');
1288 debug_printf("file_get: got '%c' %d\n", ch, ch);
1289 #if ENABLE_HUSH_INTERACTIVE
1296 /* All callers guarantee this routine will never
1297 * be used right after a newline, so prompting is not needed.
1299 static int file_peek(struct in_str *i)
1302 if (i->p && *i->p) {
1303 if (i->eof_flag && !i->p[1])
1306 /* note: ch is never NUL */
1308 do ch = fgetc(i->file); while (ch == '\0');
1309 i->eof_flag = (ch == EOF);
1310 i->peek_buf[0] = ch;
1311 i->peek_buf[1] = '\0';
1313 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1317 static void setup_file_in_str(struct in_str *i, FILE *f)
1319 i->peek = file_peek;
1321 #if ENABLE_HUSH_INTERACTIVE
1323 i->promptmode = 0; /* PS1 */
1329 static void setup_string_in_str(struct in_str *i, const char *s)
1331 i->peek = static_peek;
1332 i->get = static_get;
1333 #if ENABLE_HUSH_INTERACTIVE
1335 i->promptmode = 0; /* PS1 */
1345 #define B_CHUNK (32 * sizeof(char*))
1347 static void o_reset(o_string *o)
1355 static void o_free(o_string *o)
1358 memset(o, 0, sizeof(*o));
1361 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1366 static void o_grow_by(o_string *o, int len)
1368 if (o->length + len > o->maxlen) {
1369 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1370 o->data = xrealloc(o->data, 1 + o->maxlen);
1374 static void o_addchr(o_string *o, int ch)
1376 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1378 o->data[o->length] = ch;
1380 o->data[o->length] = '\0';
1383 static void o_addblock(o_string *o, const char *str, int len)
1386 memcpy(&o->data[o->length], str, len);
1388 o->data[o->length] = '\0';
1392 static void o_addstr(o_string *o, const char *str)
1394 o_addblock(o, str, strlen(str));
1396 static void nommu_addchr(o_string *o, int ch)
1402 #define nommu_addchr(o, str) ((void)0)
1405 static void o_addstr_with_NUL(o_string *o, const char *str)
1407 o_addblock(o, str, strlen(str) + 1);
1410 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1415 && (*str != '*' && *str != '?' && *str != '[')
1423 /* My analysis of quoting semantics tells me that state information
1424 * is associated with a destination, not a source.
1426 static void o_addqchr(o_string *o, int ch)
1429 char *found = strchr("*?[\\", ch);
1434 o->data[o->length] = '\\';
1437 o->data[o->length] = ch;
1439 o->data[o->length] = '\0';
1442 static void o_addQchr(o_string *o, int ch)
1445 if (o->o_escape && strchr("*?[\\", ch)) {
1447 o->data[o->length] = '\\';
1451 o->data[o->length] = ch;
1453 o->data[o->length] = '\0';
1456 static void o_addQstr(o_string *o, const char *str, int len)
1459 o_addblock(o, str, len);
1465 int ordinary_cnt = strcspn(str, "*?[\\");
1466 if (ordinary_cnt > len) /* paranoia */
1468 o_addblock(o, str, ordinary_cnt);
1469 if (ordinary_cnt == len)
1471 str += ordinary_cnt;
1472 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1476 if (ch) { /* it is necessarily one of "*?[\\" */
1478 o->data[o->length] = '\\';
1482 o->data[o->length] = ch;
1484 o->data[o->length] = '\0';
1488 /* A special kind of o_string for $VAR and `cmd` expansion.
1489 * It contains char* list[] at the beginning, which is grown in 16 element
1490 * increments. Actual string data starts at the next multiple of 16 * (char*).
1491 * list[i] contains an INDEX (int!) into this string data.
1492 * It means that if list[] needs to grow, data needs to be moved higher up
1493 * but list[i]'s need not be modified.
1494 * NB: remembering how many list[i]'s you have there is crucial.
1495 * o_finalize_list() operation post-processes this structure - calculates
1496 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1498 #if DEBUG_EXPAND || DEBUG_GLOB
1499 static void debug_print_list(const char *prefix, o_string *o, int n)
1501 char **list = (char**)o->data;
1502 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1504 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1505 prefix, list, n, string_start, o->length, o->maxlen);
1507 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1508 o->data + (int)list[i] + string_start,
1509 o->data + (int)list[i] + string_start);
1513 const char *p = o->data + (int)list[n - 1] + string_start;
1514 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1518 #define debug_print_list(prefix, o, n) ((void)0)
1521 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1522 * in list[n] so that it points past last stored byte so far.
1523 * It returns n+1. */
1524 static int o_save_ptr_helper(o_string *o, int n)
1526 char **list = (char**)o->data;
1530 if (!o->has_empty_slot) {
1531 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1532 string_len = o->length - string_start;
1533 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1534 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1535 /* list[n] points to string_start, make space for 16 more pointers */
1536 o->maxlen += 0x10 * sizeof(list[0]);
1537 o->data = xrealloc(o->data, o->maxlen + 1);
1538 list = (char**)o->data;
1539 memmove(list + n + 0x10, list + n, string_len);
1540 o->length += 0x10 * sizeof(list[0]);
1542 debug_printf_list("list[%d]=%d string_start=%d\n",
1543 n, string_len, string_start);
1546 /* We have empty slot at list[n], reuse without growth */
1547 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1548 string_len = o->length - string_start;
1549 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1550 n, string_len, string_start);
1551 o->has_empty_slot = 0;
1553 list[n] = (char*)(ptrdiff_t)string_len;
1557 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1558 static int o_get_last_ptr(o_string *o, int n)
1560 char **list = (char**)o->data;
1561 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1563 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1566 /* o_glob performs globbing on last list[], saving each result
1567 * as a new list[]. */
1568 static int o_glob(o_string *o, int n)
1574 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1576 return o_save_ptr_helper(o, n);
1577 pattern = o->data + o_get_last_ptr(o, n);
1578 debug_printf_glob("glob pattern '%s'\n", pattern);
1579 if (!glob_needed(pattern)) {
1581 o->length = unbackslash(pattern) - o->data;
1582 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1583 return o_save_ptr_helper(o, n);
1586 memset(&globdata, 0, sizeof(globdata));
1587 gr = glob(pattern, 0, NULL, &globdata);
1588 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1589 if (gr == GLOB_NOSPACE)
1590 bb_error_msg_and_die("out of memory during glob");
1591 if (gr == GLOB_NOMATCH) {
1592 globfree(&globdata);
1595 if (gr != 0) { /* GLOB_ABORTED ? */
1596 //TODO: testcase for bad glob pattern behavior
1597 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1599 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1600 char **argv = globdata.gl_pathv;
1601 o->length = pattern - o->data; /* "forget" pattern */
1603 o_addstr_with_NUL(o, *argv);
1604 n = o_save_ptr_helper(o, n);
1610 globfree(&globdata);
1612 debug_print_list("o_glob returning", o, n);
1616 /* If o->o_glob == 1, glob the string so far remembered.
1617 * Otherwise, just finish current list[] and start new */
1618 static int o_save_ptr(o_string *o, int n)
1620 if (o->o_glob) { /* if globbing is requested */
1621 /* If o->has_empty_slot, list[n] was already globbed
1622 * (if it was requested back then when it was filled)
1623 * so don't do that again! */
1624 if (!o->has_empty_slot)
1625 return o_glob(o, n); /* o_save_ptr_helper is inside */
1627 return o_save_ptr_helper(o, n);
1630 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1631 static char **o_finalize_list(o_string *o, int n)
1636 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1638 debug_print_list("finalized", o, n);
1639 debug_printf_expand("finalized n:%d\n", n);
1640 list = (char**)o->data;
1641 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1645 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1651 /* Expansion can recurse */
1652 #if ENABLE_HUSH_TICK
1653 static int process_command_subs(o_string *dest, const char *s);
1655 static char *expand_string_to_string(const char *str);
1657 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1658 parse_stream_dquoted(dest, input, dquote_end)
1660 static int parse_stream_dquoted(o_string *as_string,
1662 struct in_str *input,
1665 /* expand_strvec_to_strvec() takes a list of strings, expands
1666 * all variable references within and returns a pointer to
1667 * a list of expanded strings, possibly with larger number
1668 * of strings. (Think VAR="a b"; echo $VAR).
1669 * This new list is allocated as a single malloc block.
1670 * NULL-terminated list of char* pointers is at the beginning of it,
1671 * followed by strings themself.
1672 * Caller can deallocate entire list by single free(list). */
1674 /* Store given string, finalizing the word and starting new one whenever
1675 * we encounter IFS char(s). This is used for expanding variable values.
1676 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1677 static int expand_on_ifs(o_string *output, int n, const char *str)
1680 int word_len = strcspn(str, G.ifs);
1682 if (output->o_escape || !output->o_glob)
1683 o_addQstr(output, str, word_len);
1684 else /* protect backslashes against globbing up :) */
1685 o_addblock_duplicate_backslash(output, str, word_len);
1688 if (!*str) /* EOL - do not finalize word */
1690 o_addchr(output, '\0');
1691 debug_print_list("expand_on_ifs", output, n);
1692 n = o_save_ptr(output, n);
1693 str += strspn(str, G.ifs); /* skip ifs chars */
1695 debug_print_list("expand_on_ifs[1]", output, n);
1699 /* Helper to expand $((...)) and heredoc body. These act as if
1700 * they are in double quotes, with the exception that they are not :).
1701 * Just the rules are similar: "expand only $var and `cmd`"
1703 * Returns malloced string.
1704 * As an optimization, we return NULL if expansion is not needed.
1706 static char *expand_pseudo_dquoted(const char *str)
1709 struct in_str input;
1710 o_string dest = NULL_O_STRING;
1712 if (strchr(str, '$') == NULL
1713 #if ENABLE_HUSH_TICK
1714 && strchr(str, '`') == NULL
1720 /* We need to expand. Example:
1721 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1723 setup_string_in_str(&input, str);
1724 parse_stream_dquoted(NULL, &dest, &input, EOF);
1725 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1726 exp_str = expand_string_to_string(dest.data);
1727 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1728 o_free_unsafe(&dest);
1732 /* Expand all variable references in given string, adding words to list[]
1733 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1734 * to be filled). This routine is extremely tricky: has to deal with
1735 * variables/parameters with whitespace, $* and $@, and constructs like
1736 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1737 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1739 /* or_mask is either 0 (normal case) or 0x80
1740 * (expansion of right-hand side of assignment == 1-element expand.
1741 * It will also do no globbing, and thus we must not backslash-quote!) */
1743 char first_ch, ored_ch;
1751 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1752 debug_print_list("expand_vars_to_list", output, n);
1753 n = o_save_ptr(output, n);
1754 debug_print_list("expand_vars_to_list[0]", output, n);
1756 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1757 #if ENABLE_HUSH_TICK
1758 o_string subst_result = NULL_O_STRING;
1760 #if ENABLE_SH_MATH_SUPPORT
1761 char arith_buf[sizeof(arith_t)*3 + 2];
1763 o_addblock(output, arg, p - arg);
1764 debug_print_list("expand_vars_to_list[1]", output, n);
1766 p = strchr(p, SPECIAL_VAR_SYMBOL);
1768 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1769 /* "$@" is special. Even if quoted, it can still
1770 * expand to nothing (not even an empty string) */
1771 if ((first_ch & 0x7f) != '@')
1772 ored_ch |= first_ch;
1775 switch (first_ch & 0x7f) {
1776 /* Highest bit in first_ch indicates that var is double-quoted */
1778 val = utoa(G.root_pid);
1780 case '!': /* bg pid */
1781 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1783 case '?': /* exitcode */
1784 val = utoa(G.last_exitcode);
1786 case '#': /* argc */
1787 if (arg[1] != SPECIAL_VAR_SYMBOL)
1788 /* actually, it's a ${#var} */
1790 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1795 if (!G.global_argv[i])
1797 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1798 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1799 smallint sv = output->o_escape;
1800 /* unquoted var's contents should be globbed, so don't escape */
1801 output->o_escape = 0;
1802 while (G.global_argv[i]) {
1803 n = expand_on_ifs(output, n, G.global_argv[i]);
1804 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1805 if (G.global_argv[i++][0] && G.global_argv[i]) {
1806 /* this argv[] is not empty and not last:
1807 * put terminating NUL, start new word */
1808 o_addchr(output, '\0');
1809 debug_print_list("expand_vars_to_list[2]", output, n);
1810 n = o_save_ptr(output, n);
1811 debug_print_list("expand_vars_to_list[3]", output, n);
1814 output->o_escape = sv;
1816 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1817 * and in this case should treat it like '$*' - see 'else...' below */
1818 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1820 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1821 if (++i >= G.global_argc)
1823 o_addchr(output, '\0');
1824 debug_print_list("expand_vars_to_list[4]", output, n);
1825 n = o_save_ptr(output, n);
1827 } else { /* quoted $*: add as one word */
1829 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1830 if (!G.global_argv[++i])
1833 o_addchr(output, G.ifs[0]);
1837 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1838 /* "Empty variable", used to make "" etc to not disappear */
1842 #if ENABLE_HUSH_TICK
1843 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1846 //TODO: can we just stuff it into "output" directly?
1847 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1848 process_command_subs(&subst_result, arg);
1849 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1850 val = subst_result.data;
1853 #if ENABLE_SH_MATH_SUPPORT
1854 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1855 arith_eval_hooks_t hooks;
1860 arg++; /* skip '+' */
1861 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1862 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1864 exp_str = expand_pseudo_dquoted(arg);
1865 hooks.lookupvar = get_local_var_value;
1866 hooks.setvar = arith_set_local_var;
1867 hooks.endofname = endofname;
1868 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1873 case -3: maybe_die("arith", "exponent less than 0"); break;
1874 case -2: maybe_die("arith", "divide by zero"); break;
1875 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1876 default: maybe_die("arith", "syntax error"); break;
1879 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1880 sprintf(arith_buf, arith_t_fmt, res);
1885 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1887 bool exp_len = false;
1888 bool exp_null = false;
1890 char exp_save = exp_save; /* for compiler */
1891 char exp_op = exp_op; /* for compiler */
1892 char *exp_word = exp_word; /* for compiler */
1896 arg[0] = first_ch & 0x7f;
1898 /* prepare for expansions */
1899 if (var[0] == '#') {
1900 /* handle length expansion ${#var} */
1904 /* maybe handle parameter expansion */
1905 exp_off = strcspn(var, ":-=+?%#");
1909 exp_save = var[exp_off];
1910 exp_null = exp_save == ':';
1911 exp_word = var + exp_off;
1912 if (exp_null) ++exp_word;
1913 exp_op = *exp_word++;
1914 var[exp_off] = '\0';
1918 /* lookup the variable in question */
1919 if (isdigit(var[0])) {
1920 /* handle_dollar() should have vetted var for us */
1922 if (i < G.global_argc)
1923 val = G.global_argv[i];
1924 /* else val remains NULL: $N with too big N */
1926 val = get_local_var_value(var);
1928 /* handle any expansions */
1930 debug_printf_expand("expand: length of '%s' = ", val);
1931 val = utoa(val ? strlen(val) : 0);
1932 debug_printf_expand("%s\n", val);
1933 } else if (exp_off) {
1934 if (exp_op == '%' || exp_op == '#') {
1935 /* we need to do a pattern match */
1938 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
1939 if (exp_op == *exp_word) /* ## or %% */
1941 val = dyn_val = xstrdup(val);
1942 loc = scan(dyn_val, exp_word, zero);
1948 /* we need to do an expansion */
1949 int exp_test = (!val || (exp_null && !val[0]));
1951 exp_test = !exp_test;
1952 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1953 exp_null ? "true" : "false", exp_test);
1956 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1960 if (exp_op == '=') {
1961 if (isdigit(var[0]) || var[0] == '#') {
1962 maybe_die(var, "special vars cannot assign in this way");
1965 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1966 sprintf(new_var, "%s=%s", var, val);
1967 set_local_var(new_var, -1, 0);
1973 var[exp_off] = exp_save;
1977 #if ENABLE_HUSH_TICK
1980 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1981 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1983 /* unquoted var's contents should be globbed, so don't escape */
1984 smallint sv = output->o_escape;
1985 output->o_escape = 0;
1986 n = expand_on_ifs(output, n, val);
1988 output->o_escape = sv;
1990 } else { /* quoted $VAR, val will be appended below */
1991 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1994 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1996 o_addQstr(output, val, strlen(val));
2000 /* Do the check to avoid writing to a const string */
2001 if (*p != SPECIAL_VAR_SYMBOL)
2002 *p = SPECIAL_VAR_SYMBOL;
2004 #if ENABLE_HUSH_TICK
2005 o_free(&subst_result);
2008 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2011 debug_print_list("expand_vars_to_list[a]", output, n);
2012 /* this part is literal, and it was already pre-quoted
2013 * if needed (much earlier), do not use o_addQstr here! */
2014 o_addstr_with_NUL(output, arg);
2015 debug_print_list("expand_vars_to_list[b]", output, n);
2016 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2017 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2020 /* allow to reuse list[n] later without re-growth */
2021 output->has_empty_slot = 1;
2023 o_addchr(output, '\0');
2028 static char **expand_variables(char **argv, int or_mask)
2033 o_string output = NULL_O_STRING;
2035 if (or_mask & 0x100) {
2036 output.o_escape = 1; /* protect against globbing for "$var" */
2037 /* (unquoted $var will temporarily switch it off) */
2044 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2047 debug_print_list("expand_variables", &output, n);
2049 /* output.data (malloced in one block) gets returned in "list" */
2050 list = o_finalize_list(&output, n);
2051 debug_print_strings("expand_variables[1]", list);
2055 static char **expand_strvec_to_strvec(char **argv)
2057 return expand_variables(argv, 0x100);
2060 /* Used for expansion of right hand of assignments */
2061 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2063 static char *expand_string_to_string(const char *str)
2065 char *argv[2], **list;
2067 argv[0] = (char*)str;
2069 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2071 if (!list[0] || list[1])
2072 bb_error_msg_and_die("BUG in varexp2");
2073 /* actually, just move string 2*sizeof(char*) bytes back */
2074 overlapping_strcpy((char*)list, list[0]);
2075 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2079 /* Used for "eval" builtin */
2080 static char* expand_strvec_to_string(char **argv)
2084 list = expand_variables(argv, 0x80);
2085 /* Convert all NULs to spaces */
2090 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2091 bb_error_msg_and_die("BUG in varexp3");
2092 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2096 overlapping_strcpy((char*)list, list[0]);
2097 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2101 static char **expand_assignments(char **argv, int count)
2105 /* Expand assignments into one string each */
2106 for (i = 0; i < count; i++) {
2107 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2114 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2115 #define clean_up_after_re_execute() ((void)0)
2116 static void reset_traps_to_defaults(void)
2124 for (sig = 0; sig < NSIG; sig++) {
2128 G.traps[sig] = NULL;
2129 /* There is no signal for 0 (EXIT) */
2132 /* there was a trap handler, we are removing it
2133 * (if sig has non-DFL handling,
2134 * we don't need to do anything) */
2135 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2137 sigdelset(&G.blocked_set, sig);
2141 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2146 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2147 static void re_execute_shell(const char *s, int is_heredoc)
2149 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2150 struct variable *cur;
2151 char **argv, **pp, **pp2;
2154 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2155 , (unsigned) G.root_pid
2156 , (unsigned) G.last_bg_pid
2157 , (unsigned) G.last_exitcode
2158 USE_HUSH_LOOPS(, G.depth_of_loop)
2160 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2161 * 3:-c 4:<cmd> <argN...> 5:NULL
2163 cnt = 5 + G.global_argc;
2164 for (cur = G.top_var; cur; cur = cur->next) {
2165 if (!cur->flg_export || cur->flg_read_only)
2168 G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
2169 *pp++ = (char *) G.argv0_for_re_execing;
2171 for (cur = G.top_var; cur; cur = cur->next) {
2172 if (cur->varstr == hush_version_str)
2174 if (cur->flg_read_only) {
2175 *pp++ = (char *) "-R";
2176 *pp++ = cur->varstr;
2177 } else if (!cur->flg_export) {
2178 *pp++ = (char *) "-V";
2179 *pp++ = cur->varstr;
2182 //TODO: pass functions
2183 /* We can pass activated traps here. Say, -Tnn:trap_string
2185 * However, POSIX says that subshells reset signals with traps
2187 * I tested bash-3.2 and it not only does that with true subshells
2188 * of the form ( list ), but with any forked children shells.
2189 * I set trap "echo W" WINCH; and then tried:
2191 * { echo 1; sleep 20; echo 2; } &
2192 * while true; do echo 1; sleep 20; echo 2; break; done &
2193 * true | { echo 1; sleep 20; echo 2; } | cat
2195 * In all these cases sending SIGWINCH to the child shell
2196 * did not run the trap. If I add trap "echo V" WINCH;
2197 * _inside_ group (just before echo 1), it works.
2199 * I conclude it means we don't need to pass active traps here.
2200 * exec syscall below resets them to SIG_DFL for us.
2202 *pp++ = (char *) (is_heredoc ? "-<" : "-c");
2204 pp2 = G.global_argv;
2207 /* *pp = NULL; - is already there */
2209 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2210 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2211 execv(bb_busybox_exec_path, G.argv_from_re_execing);
2212 /* Fallback. Useful for init=/bin/hush usage etc */
2213 if (G.argv0_for_re_execing[0] == '/')
2214 execv(G.argv0_for_re_execing, G.argv_from_re_execing);
2215 xfunc_error_retval = 127;
2216 bb_error_msg_and_die("can't re-execute the shell");
2219 static void clean_up_after_re_execute(void)
2221 char **pp = G.argv_from_re_execing;
2223 /* Must match re_execute_shell's allocations (if any) */
2225 G.argv_from_re_execing = NULL;
2228 #endif /* !BB_MMU */
2231 static void setup_heredoc(struct redir_struct *redir)
2233 struct fd_pair pair;
2236 /* the _body_ of heredoc (misleading field name) */
2237 const char *heredoc = redir->rd_filename;
2241 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2242 expanded = expand_pseudo_dquoted(heredoc);
2246 len = strlen(heredoc);
2249 xmove_fd(pair.rd, redir->rd_fd);
2251 /* Try writing without forking. Newer kernels have
2252 * dynamically growing pipes. Must use non-blocking write! */
2255 written = write(pair.wr, heredoc, len);
2265 ndelay_off(pair.wr);
2267 /* Okay, pipe buffer was not big enough */
2268 /* Note: we must not create a stray child (bastard? :)
2269 * for the unsuspecting parent process. Child creates a grandchild
2270 * and exits before parent execs the process which consumes heredoc
2271 * (that exec happens after we return from this function) */
2274 bb_perror_msg_and_die("vfork");
2277 pid = BB_MMU ? fork() : vfork();
2279 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2283 close(redir->rd_fd); /* read side of the pipe */
2285 full_write(pair.wr, heredoc, len); /* may loop or block */
2288 /* Delegate blocking writes to another process */
2289 disable_restore_tty_pgrp_on_exit();
2290 xmove_fd(pair.wr, STDOUT_FILENO);
2291 re_execute_shell(heredoc, 1);
2295 enable_restore_tty_pgrp_on_exit();
2296 clean_up_after_re_execute();
2299 wait(NULL); /* wait till child has died */
2302 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2303 * and stderr if they are redirected. */
2304 static int setup_redirects(struct command *prog, int squirrel[])
2306 //TODO: no callers ever check return value - ?!
2308 struct redir_struct *redir;
2310 for (redir = prog->redirects; redir; redir = redir->next) {
2311 if (redir->rd_type == REDIRECT_HEREDOC2) {
2312 if (squirrel && redir->rd_fd < 3) {
2313 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2315 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2317 debug_printf_parse("set heredoc '%s'\n",
2318 redir->rd_filename);
2319 setup_heredoc(redir);
2323 if (redir->rd_dup == -1) {
2325 if (redir->rd_filename == NULL) {
2326 /* Something went wrong in the parse.
2327 * Pretend it didn't happen */
2330 mode = redir_table[redir->rd_type].mode;
2331 //TODO: check redir for names like '\\'
2332 p = expand_string_to_string(redir->rd_filename);
2333 openfd = open_or_warn(p, mode);
2336 /* this could get lost if stderr has been redirected, but
2337 * bash and ash both lose it as well (though zsh doesn't!) */
2338 //what the above comment tries to say?
2342 openfd = redir->rd_dup;
2345 if (openfd != redir->rd_fd) {
2346 if (squirrel && redir->rd_fd < 3) {
2347 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2349 if (openfd == REDIRFD_CLOSE) {
2350 /* "n>-" means "close me" */
2351 close(redir->rd_fd);
2353 xdup2(openfd, redir->rd_fd);
2354 if (redir->rd_dup == -1)
2362 static void restore_redirects(int squirrel[])
2365 for (i = 0; i < 3; i++) {
2368 /* We simply die on error */
2376 #define free_pipe_list(head, indent) free_pipe_list(head)
2377 #define free_pipe(pi, indent) free_pipe(pi)
2379 static void free_pipe_list(struct pipe *head, int indent);
2381 /* Return code is the exit status of the pipe */
2382 static void free_pipe(struct pipe *pi, int indent)
2385 struct command *command;
2386 struct redir_struct *r, *rnext;
2389 if (pi->stopped_cmds > 0) /* why? */
2391 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2392 for (i = 0; i < pi->num_cmds; i++) {
2393 command = &pi->cmds[i];
2394 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2395 if (command->argv) {
2396 for (a = 0, p = command->argv; *p; a++, p++) {
2397 debug_printf_clean("%s argv[%d] = %s\n",
2398 indenter(indent), a, *p);
2400 free_strings(command->argv);
2401 command->argv = NULL;
2403 /* not "else if": on syntax error, we may have both! */
2404 if (command->group) {
2405 debug_printf_clean("%s begin group (grp_type:%d)\n",
2406 indenter(indent), command->grp_type);
2407 free_pipe_list(command->group, indent+3);
2408 debug_printf_clean("%s end group\n", indenter(indent));
2409 command->group = NULL;
2412 free(command->group_as_string);
2413 command->group_as_string = NULL;
2415 for (r = command->redirects; r; r = rnext) {
2416 debug_printf_clean("%s redirect %d%s", indenter(indent),
2417 r->fd, redir_table[r->rd_type].descrip);
2418 /* guard against the case >$FOO, where foo is unset or blank */
2419 if (r->rd_filename) {
2420 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2421 free(r->rd_filename);
2422 r->rd_filename = NULL;
2424 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2428 command->redirects = NULL;
2430 free(pi->cmds); /* children are an array, they get freed all at once */
2438 static void free_pipe_list(struct pipe *head, int indent)
2440 struct pipe *pi, *next;
2442 for (pi = head; pi; pi = next) {
2444 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2446 free_pipe(pi, indent);
2447 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2449 /*pi->next = NULL;*/
2456 typedef struct nommu_save_t {
2462 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2463 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2464 #define pseudo_exec(nommu_save, command, argv_expanded) \
2465 pseudo_exec(command, argv_expanded)
2468 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2470 * XXX no exit() here. If you don't exec, use _exit instead.
2471 * The at_exit handlers apparently confuse the calling process,
2472 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2473 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2474 char **argv, int assignment_cnt,
2475 char **argv_expanded) NORETURN;
2476 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2477 char **argv, int assignment_cnt,
2478 char **argv_expanded)
2482 /* Case when we are here: ... | var=val | ... */
2483 if (!argv[assignment_cnt])
2484 _exit(EXIT_SUCCESS);
2486 new_env = expand_assignments(argv, assignment_cnt);
2488 putenv_all(new_env);
2489 free(new_env); /* optional */
2491 nommu_save->new_env = new_env;
2492 nommu_save->old_env = putenv_all_and_save_old(new_env);
2494 if (argv_expanded) {
2495 argv = argv_expanded;
2497 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2499 nommu_save->argv = argv;
2503 /* On NOMMU, we must never block!
2504 * Example: { sleep 99999 | read line } & echo Ok
2505 * read builtin will block on read syscall, leaving parent blocked
2506 * in vfork. Therefore we can't do this:
2509 /* Check if the command matches any of the builtins.
2510 * Depending on context, this might be redundant. But it's
2511 * easier to waste a few CPU cycles than it is to figure out
2512 * if this is one of those cases.
2516 const struct built_in_command *x;
2517 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2518 if (strcmp(argv[0], x->cmd) == 0) {
2519 debug_printf_exec("running builtin '%s'\n",
2521 rcode = x->function(argv);
2529 #if ENABLE_FEATURE_SH_STANDALONE
2530 /* Check if the command matches any busybox applets */
2531 if (strchr(argv[0], '/') == NULL) {
2532 int a = find_applet_by_name(argv[0]);
2534 #if BB_MMU /* see above why on NOMMU it is not allowed */
2535 if (APPLET_IS_NOEXEC(a)) {
2536 debug_printf_exec("running applet '%s'\n", argv[0]);
2537 run_applet_no_and_exit(a, argv);
2540 /* Re-exec ourselves */
2541 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2542 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2543 execv(bb_busybox_exec_path, argv);
2544 /* If they called chroot or otherwise made the binary no longer
2545 * executable, fall through */
2550 debug_printf_exec("execing '%s'\n", argv[0]);
2551 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2552 execvp(argv[0], argv);
2553 bb_perror_msg("can't exec '%s'", argv[0]);
2554 _exit(EXIT_FAILURE);
2557 static int run_list(struct pipe *pi);
2559 /* Called after [v]fork() in run_pipe
2561 static void pseudo_exec(nommu_save_t *nommu_save,
2562 struct command *command,
2563 char **argv_expanded) NORETURN;
2564 static void pseudo_exec(nommu_save_t *nommu_save,
2565 struct command *command,
2566 char **argv_expanded)
2568 if (command->argv) {
2569 pseudo_exec_argv(nommu_save, command->argv,
2570 command->assignment_cnt, argv_expanded);
2573 if (command->group) {
2574 /* Cases when we are here:
2577 * ... | ( list ) | ...
2578 * ... | { list } | ...
2582 debug_printf_exec("pseudo_exec: run_list\n");
2583 reset_traps_to_defaults();
2584 rcode = run_list(command->group);
2585 /* OK to leak memory by not calling free_pipe_list,
2586 * since this process is about to exit */
2589 re_execute_shell(command->group_as_string, 0);
2593 /* Case when we are here: ... | >file */
2594 debug_printf_exec("pseudo_exec'ed null command\n");
2595 _exit(EXIT_SUCCESS);
2599 static const char *get_cmdtext(struct pipe *pi)
2605 /* This is subtle. ->cmdtext is created only on first backgrounding.
2606 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2607 * On subsequent bg argv is trashed, but we won't use it */
2610 argv = pi->cmds[0].argv;
2611 if (!argv || !argv[0]) {
2612 pi->cmdtext = xzalloc(1);
2617 do len += strlen(*argv) + 1; while (*++argv);
2618 pi->cmdtext = p = xmalloc(len);
2619 argv = pi->cmds[0].argv;
2621 len = strlen(*argv);
2622 memcpy(p, *argv, len);
2630 static void insert_bg_job(struct pipe *pi)
2632 struct pipe *thejob;
2635 /* Linear search for the ID of the job to use */
2637 for (thejob = G.job_list; thejob; thejob = thejob->next)
2638 if (thejob->jobid >= pi->jobid)
2639 pi->jobid = thejob->jobid + 1;
2641 /* Add thejob to the list of running jobs */
2643 thejob = G.job_list = xmalloc(sizeof(*thejob));
2645 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2647 thejob->next = xmalloc(sizeof(*thejob));
2648 thejob = thejob->next;
2651 /* Physically copy the struct job */
2652 memcpy(thejob, pi, sizeof(struct pipe));
2653 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2654 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2655 for (i = 0; i < pi->num_cmds; i++) {
2656 // TODO: do we really need to have so many fields which are just dead weight
2657 // at execution stage?
2658 thejob->cmds[i].pid = pi->cmds[i].pid;
2659 /* all other fields are not used and stay zero */
2661 thejob->next = NULL;
2662 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2664 /* We don't wait for background thejobs to return -- append it
2665 to the list of backgrounded thejobs and leave it alone */
2666 if (G_interactive_fd)
2667 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2668 G.last_bg_pid = thejob->cmds[0].pid;
2669 G.last_jobid = thejob->jobid;
2672 static void remove_bg_job(struct pipe *pi)
2674 struct pipe *prev_pipe;
2676 if (pi == G.job_list) {
2677 G.job_list = pi->next;
2679 prev_pipe = G.job_list;
2680 while (prev_pipe->next != pi)
2681 prev_pipe = prev_pipe->next;
2682 prev_pipe->next = pi->next;
2685 G.last_jobid = G.job_list->jobid;
2690 /* Remove a backgrounded job */
2691 static void delete_finished_bg_job(struct pipe *pi)
2694 pi->stopped_cmds = 0;
2700 /* Check to see if any processes have exited -- if they
2701 * have, figure out why and see if a job has completed */
2702 static int checkjobs(struct pipe* fg_pipe)
2712 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2715 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2716 // /* avoid doing syscall, nothing there anyway */
2719 attributes = WUNTRACED;
2720 if (fg_pipe == NULL)
2721 attributes |= WNOHANG;
2723 /* Do we do this right?
2724 * bash-3.00# sleep 20 | false
2726 * [3]+ Stopped sleep 20 | false
2727 * bash-3.00# echo $?
2728 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2731 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2732 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2733 // + killall -STOP cat
2740 // i = G.count_SIGCHLD;
2741 childpid = waitpid(-1, &status, attributes);
2742 if (childpid <= 0) {
2743 if (childpid && errno != ECHILD)
2744 bb_perror_msg("waitpid");
2745 // else /* Until next SIGCHLD, waitpid's are useless */
2746 // G.handled_SIGCHLD = i;
2749 dead = WIFEXITED(status) || WIFSIGNALED(status);
2752 if (WIFSTOPPED(status))
2753 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2754 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2755 if (WIFSIGNALED(status))
2756 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2757 childpid, WTERMSIG(status), WEXITSTATUS(status));
2758 if (WIFEXITED(status))
2759 debug_printf_jobs("pid %d exited, exitcode %d\n",
2760 childpid, WEXITSTATUS(status));
2762 /* Were we asked to wait for fg pipe? */
2764 for (i = 0; i < fg_pipe->num_cmds; i++) {
2765 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2766 if (fg_pipe->cmds[i].pid != childpid)
2768 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2770 fg_pipe->cmds[i].pid = 0;
2771 fg_pipe->alive_cmds--;
2772 if (i == fg_pipe->num_cmds - 1) {
2773 /* last process gives overall exitstatus */
2774 rcode = WEXITSTATUS(status);
2775 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2778 fg_pipe->cmds[i].is_stopped = 1;
2779 fg_pipe->stopped_cmds++;
2781 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2782 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2783 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2784 /* All processes in fg pipe have exited/stopped */
2786 if (fg_pipe->alive_cmds)
2787 insert_bg_job(fg_pipe);
2791 /* There are still running processes in the fg pipe */
2792 goto wait_more; /* do waitpid again */
2794 /* it wasnt fg_pipe, look for process in bg pipes */
2798 /* We asked to wait for bg or orphaned children */
2799 /* No need to remember exitcode in this case */
2800 for (pi = G.job_list; pi; pi = pi->next) {
2801 for (i = 0; i < pi->num_cmds; i++) {
2802 if (pi->cmds[i].pid == childpid)
2803 goto found_pi_and_prognum;
2806 /* Happens when shell is used as init process (init=/bin/sh) */
2807 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2808 continue; /* do waitpid again */
2810 found_pi_and_prognum:
2813 pi->cmds[i].pid = 0;
2815 if (!pi->alive_cmds) {
2816 if (G_interactive_fd)
2817 printf(JOB_STATUS_FORMAT, pi->jobid,
2818 "Done", pi->cmdtext);
2819 delete_finished_bg_job(pi);
2823 pi->cmds[i].is_stopped = 1;
2827 } /* while (waitpid succeeds)... */
2833 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2836 int rcode = checkjobs(fg_pipe);
2837 /* Job finished, move the shell to the foreground */
2838 p = getpgid(0); /* pgid of our process */
2839 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2840 tcsetpgrp(G_interactive_fd, p);
2845 /* Start all the jobs, but don't wait for anything to finish.
2848 * Return code is normally -1, when the caller has to wait for children
2849 * to finish to determine the exit status of the pipe. If the pipe
2850 * is a simple builtin command, however, the action is done by the
2851 * time run_pipe returns, and the exit code is provided as the
2854 * Returns -1 only if started some children. IOW: we have to
2855 * mask out retvals of builtins etc with 0xff!
2857 * The only case when we do not need to [v]fork is when the pipe
2858 * is single, non-backgrounded, non-subshell command. Examples:
2859 * cmd ; ... { list } ; ...
2860 * cmd && ... { list } && ...
2861 * cmd || ... { list } || ...
2862 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2863 * or (if SH_STANDALONE) an applet, and we can run the { list }
2864 * with run_list(). If it isn't one of these, we fork and exec cmd.
2866 * Cases when we must fork:
2867 * non-single: cmd | cmd
2868 * backgrounded: cmd & { list } &
2869 * subshell: ( list ) [&]
2871 static int run_pipe(struct pipe *pi)
2873 static const char *const null_ptr = NULL;
2876 int pipefds[2]; /* pipefds[0] is for reading */
2877 struct command *command;
2878 char **argv_expanded;
2881 /* it is not always needed, but we aim to smaller code */
2882 int squirrel[] = { -1, -1, -1 };
2885 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2887 USE_HUSH_JOB(pi->pgrp = -1;)
2888 pi->stopped_cmds = 0;
2889 command = &(pi->cmds[0]);
2890 argv_expanded = NULL;
2892 if (pi->num_cmds != 1
2893 || pi->followup == PIPE_BG
2894 || command->grp_type == GRP_SUBSHELL
2901 debug_printf_exec(": group:%p argv:'%s'\n",
2902 command->group, command->argv ? command->argv[0] : "NONE");
2904 if (command->group) {
2905 #if ENABLE_HUSH_FUNCTIONS
2906 if (command->grp_type == GRP_FUNCTION) {
2907 /* func () { list } */
2908 bb_error_msg("here we ought to remember function definition, and go on");
2909 return EXIT_SUCCESS;
2913 debug_printf("non-subshell group\n");
2914 setup_redirects(command, squirrel);
2915 debug_printf_exec(": run_list\n");
2916 rcode = run_list(command->group) & 0xff;
2917 restore_redirects(squirrel);
2918 debug_printf_exec("run_pipe return %d\n", rcode);
2919 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2923 argv = command->argv ? command->argv : (char **) &null_ptr;
2925 const struct built_in_command *x;
2926 char **new_env = NULL;
2927 char **old_env = NULL;
2929 if (argv[command->assignment_cnt] == NULL) {
2930 /* Assignments, but no command */
2931 /* Ensure redirects take effect. Try "a=t >file" */
2932 setup_redirects(command, squirrel);
2933 restore_redirects(squirrel);
2934 /* Set shell variables */
2936 p = expand_string_to_string(*argv);
2937 debug_printf_exec("set shell var:'%s'->'%s'\n",
2939 set_local_var(p, 0, 0);
2942 /* Do we need to flag set_local_var() errors?
2943 * "assignment to readonly var" and "putenv error"
2945 return EXIT_SUCCESS;
2948 /* Expand the rest into (possibly) many strings each */
2949 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2951 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2952 if (strcmp(argv_expanded[0], x->cmd) != 0)
2954 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2955 debug_printf("exec with redirects only\n");
2956 setup_redirects(command, NULL);
2957 rcode = EXIT_SUCCESS;
2958 goto clean_up_and_ret1;
2960 debug_printf("builtin inline %s\n", argv_expanded[0]);
2961 /* XXX setup_redirects acts on file descriptors, not FILEs.
2962 * This is perfect for work that comes after exec().
2963 * Is it really safe for inline use? Experimentally,
2964 * things seem to work with glibc. */
2965 setup_redirects(command, squirrel);
2966 new_env = expand_assignments(argv, command->assignment_cnt);
2967 old_env = putenv_all_and_save_old(new_env);
2968 debug_printf_exec(": builtin '%s' '%s'...\n",
2969 x->cmd, argv_expanded[1]);
2970 rcode = x->function(argv_expanded) & 0xff;
2971 #if ENABLE_FEATURE_SH_STANDALONE
2974 restore_redirects(squirrel);
2975 free_strings_and_unsetenv(new_env, 1);
2976 putenv_all(old_env);
2977 free(old_env); /* not free_strings()! */
2979 free(argv_expanded);
2980 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2981 debug_printf_exec("run_pipe return %d\n", rcode);
2984 #if ENABLE_FEATURE_SH_STANDALONE
2985 i = find_applet_by_name(argv_expanded[0]);
2986 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2987 setup_redirects(command, squirrel);
2988 save_nofork_data(&G.nofork_save);
2989 new_env = expand_assignments(argv, command->assignment_cnt);
2990 old_env = putenv_all_and_save_old(new_env);
2991 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
2992 argv_expanded[0], argv_expanded[1]);
2993 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2994 goto clean_up_and_ret;
2997 /* It is neither builtin nor applet. We must fork. */
3001 /* NB: argv_expanded may already be created, and that
3002 * might include `cmd` runs! Do not rerun it! We *must*
3003 * use argv_expanded if it's non-NULL */
3005 /* Going to fork a child per each pipe member */
3009 for (i = 0; i < pi->num_cmds; i++) {
3011 volatile nommu_save_t nommu_save;
3012 nommu_save.new_env = NULL;
3013 nommu_save.old_env = NULL;
3014 nommu_save.argv = NULL;
3016 command = &(pi->cmds[i]);
3017 if (command->argv) {
3018 debug_printf_exec(": pipe member '%s' '%s'...\n",
3019 command->argv[0], command->argv[1]);
3021 debug_printf_exec(": pipe member with no argv\n");
3024 /* pipes are inserted between pairs of commands */
3027 if ((i + 1) < pi->num_cmds)
3030 command->pid = BB_MMU ? fork() : vfork();
3031 if (!command->pid) { /* child */
3033 disable_restore_tty_pgrp_on_exit();
3035 /* Every child adds itself to new process group
3036 * with pgid == pid_of_first_child_in_pipe */
3037 if (G.run_list_level == 1 && G_interactive_fd) {
3040 if (pgrp < 0) /* true for 1st process only */
3042 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3043 /* We do it in *every* child, not just first,
3045 tcsetpgrp(G_interactive_fd, pgrp);
3049 xmove_fd(nextin, 0);
3050 xmove_fd(pipefds[1], 1); /* write end */
3052 close(pipefds[0]); /* read end */
3053 /* Like bash, explicit redirects override pipes,
3054 * and the pipe fd is available for dup'ing. */
3055 setup_redirects(command, NULL);
3057 /* Restore default handlers just prior to exec */
3058 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3060 /* Stores to nommu_save list of env vars putenv'ed
3061 * (NOMMU, on MMU we don't need that) */
3062 /* cast away volatility... */
3063 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3064 /* pseudo_exec() does not return */
3067 /* parent or error */
3068 enable_restore_tty_pgrp_on_exit();
3070 /* Clean up after vforked child */
3071 clean_up_after_re_execute();
3072 free(nommu_save.argv);
3073 free_strings_and_unsetenv(nommu_save.new_env, 1);
3074 putenv_all(nommu_save.old_env);
3076 free(argv_expanded);
3077 argv_expanded = NULL;
3078 if (command->pid < 0) { /* [v]fork failed */
3079 /* Clearly indicate, was it fork or vfork */
3080 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3084 /* Second and next children need to know pid of first one */
3086 pi->pgrp = command->pid;
3092 if ((i + 1) < pi->num_cmds)
3093 close(pipefds[1]); /* write end */
3094 /* Pass read (output) pipe end to next iteration */
3095 nextin = pipefds[0];
3098 if (!pi->alive_cmds) {
3099 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3103 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3107 #ifndef debug_print_tree
3108 static void debug_print_tree(struct pipe *pi, int lvl)
3110 static const char *const PIPE[] = {
3116 static const char *RES[] = {
3117 [RES_NONE ] = "NONE" ,
3120 [RES_THEN ] = "THEN" ,
3121 [RES_ELIF ] = "ELIF" ,
3122 [RES_ELSE ] = "ELSE" ,
3125 #if ENABLE_HUSH_LOOPS
3126 [RES_FOR ] = "FOR" ,
3127 [RES_WHILE] = "WHILE",
3128 [RES_UNTIL] = "UNTIL",
3130 [RES_DONE ] = "DONE" ,
3132 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3135 #if ENABLE_HUSH_CASE
3136 [RES_CASE ] = "CASE" ,
3137 [RES_MATCH] = "MATCH",
3138 [RES_CASEI] = "CASEI",
3139 [RES_ESAC ] = "ESAC" ,
3141 [RES_XXXX ] = "XXXX" ,
3142 [RES_SNTX ] = "SNTX" ,
3144 static const char *const GRPTYPE[] = {
3147 #if ENABLE_HUSH_FUNCTIONS
3156 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3157 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3159 while (prn < pi->num_cmds) {
3160 struct command *command = &pi->cmds[prn];
3161 char **argv = command->argv;
3163 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3165 command->assignment_cnt);
3166 if (command->group) {
3167 fprintf(stderr, " group %s: (argv=%p)\n",
3168 GRPTYPE[command->grp_type],
3170 debug_print_tree(command->group, lvl+1);
3174 if (argv) while (*argv) {
3175 fprintf(stderr, " '%s'", *argv);
3178 fprintf(stderr, "\n");
3187 /* NB: called by pseudo_exec, and therefore must not modify any
3188 * global data until exec/_exit (we can be a child after vfork!) */
3189 static int run_list(struct pipe *pi)
3191 #if ENABLE_HUSH_CASE
3192 char *case_word = NULL;
3194 #if ENABLE_HUSH_LOOPS
3195 struct pipe *loop_top = NULL;
3196 char *for_varname = NULL;
3197 char **for_lcur = NULL;
3198 char **for_list = NULL;
3200 smallint last_followup;
3202 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3203 smalluint cond_code = 0;
3205 enum { cond_code = 0 };
3208 smallint rword; /* enum reserved_style */
3209 smallint last_rword; /* ditto */
3212 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3214 #if ENABLE_HUSH_LOOPS
3215 /* Check syntax for "for" */
3216 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3217 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3219 /* current word is FOR or IN (BOLD in comments below) */
3220 if (cpipe->next == NULL) {
3221 syntax("malformed for");
3222 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3225 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3226 if (cpipe->next->res_word == RES_DO)
3228 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3229 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3230 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3232 syntax("malformed for");
3233 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3239 /* Past this point, all code paths should jump to ret: label
3240 * in order to return, no direct "return" statements please.
3241 * This helps to ensure that no memory is leaked. */
3243 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3246 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3247 * We are saving state before entering outermost list ("while...done")
3248 * so that ctrl-Z will correctly background _entire_ outermost list,
3249 * not just a part of it (like "sleep 1 | exit 2") */
3250 if (++G.run_list_level == 1 && G_interactive_fd) {
3251 if (sigsetjmp(G.toplevel_jb, 1)) {
3252 /* ctrl-Z forked and we are parent; or ctrl-C.
3253 * Sighandler has longjmped us here */
3254 signal(SIGINT, SIG_IGN);
3255 signal(SIGTSTP, SIG_IGN);
3256 /* Restore level (we can be coming from deep inside
3258 G.run_list_level = 1;
3259 #if ENABLE_FEATURE_SH_STANDALONE
3260 if (G.nofork_save.saved) { /* if save area is valid */
3261 debug_printf_jobs("exiting nofork early\n");
3262 restore_nofork_data(&G.nofork_save);
3265 //// if (G.ctrl_z_flag) {
3266 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3267 //// * Remember this child as background job */
3268 //// insert_bg_job(pi);
3270 /* ctrl-C. We just stop doing whatever we were doing */
3273 USE_HUSH_LOOPS(loop_top = NULL;)
3274 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3278 //// /* ctrl-Z handler will store pid etc in pi */
3279 //// G.toplevel_list = pi;
3280 //// G.ctrl_z_flag = 0;
3281 ////#if ENABLE_FEATURE_SH_STANDALONE
3282 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
3284 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3285 //// signal(SIGINT, handler_ctrl_c);
3291 last_rword = RES_XXXX;
3293 last_followup = PIPE_SEQ;
3294 rcode = G.last_exitcode;
3296 /* Go through list of pipes, (maybe) executing them. */
3297 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3301 IF_HAS_KEYWORDS(rword = pi->res_word;)
3302 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3303 rword, cond_code, last_rword);
3304 #if ENABLE_HUSH_LOOPS
3305 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3306 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3308 /* start of a loop: remember where loop starts */
3313 /* Still in the same "if...", "then..." or "do..." branch? */
3314 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3315 if ((rcode == 0 && last_followup == PIPE_OR)
3316 || (rcode != 0 && last_followup == PIPE_AND)
3318 /* It is "<true> || CMD" or "<false> && CMD"
3319 * and we should not execute CMD */
3320 debug_printf_exec("skipped cmd because of || or &&\n");
3321 last_followup = pi->followup;
3325 last_followup = pi->followup;
3326 IF_HAS_KEYWORDS(last_rword = rword;)
3329 if (rword == RES_THEN) {
3330 /* if false; then ... fi has exitcode 0! */
3331 G.last_exitcode = rcode = EXIT_SUCCESS;
3332 /* "if <false> THEN cmd": skip cmd */
3336 if (rword == RES_ELSE || rword == RES_ELIF) {
3337 /* "if <true> then ... ELSE/ELIF cmd":
3338 * skip cmd and all following ones */
3343 #if ENABLE_HUSH_LOOPS
3344 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3346 /* first loop through for */
3348 static const char encoded_dollar_at[] ALIGN1 = {
3349 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3350 }; /* encoded representation of "$@" */
3351 static const char *const encoded_dollar_at_argv[] = {
3352 encoded_dollar_at, NULL
3353 }; /* argv list with one element: "$@" */
3356 vals = (char**)encoded_dollar_at_argv;
3357 if (pi->next->res_word == RES_IN) {
3358 /* if no variable values after "in" we skip "for" */
3359 if (!pi->next->cmds[0].argv) {
3360 G.last_exitcode = rcode = EXIT_SUCCESS;
3361 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3364 vals = pi->next->cmds[0].argv;
3365 } /* else: "for var; do..." -> assume "$@" list */
3366 /* create list of variable values */
3367 debug_print_strings("for_list made from", vals);
3368 for_list = expand_strvec_to_strvec(vals);
3369 for_lcur = for_list;
3370 debug_print_strings("for_list", for_list);
3371 for_varname = pi->cmds[0].argv[0];
3372 pi->cmds[0].argv[0] = NULL;
3374 free(pi->cmds[0].argv[0]);
3376 /* "for" loop is over, clean up */
3380 pi->cmds[0].argv[0] = for_varname;
3383 /* Insert next value from for_lcur */
3384 //TODO: does it need escaping?
3385 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3386 pi->cmds[0].assignment_cnt = 1;
3388 if (rword == RES_IN) {
3389 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3391 if (rword == RES_DONE) {
3392 continue; /* "done" has no cmds too */
3395 #if ENABLE_HUSH_CASE
3396 if (rword == RES_CASE) {
3397 case_word = expand_strvec_to_string(pi->cmds->argv);
3400 if (rword == RES_MATCH) {
3403 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3405 /* all prev words didn't match, does this one match? */
3406 argv = pi->cmds->argv;
3408 char *pattern = expand_string_to_string(*argv);
3409 /* TODO: which FNM_xxx flags to use? */
3410 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3412 if (cond_code == 0) { /* match! we will execute this branch */
3413 free(case_word); /* make future "word)" stop */
3421 if (rword == RES_CASEI) { /* inside of a case branch */
3423 continue; /* not matched yet, skip this pipe */
3426 /* Just pressing <enter> in shell should check for jobs.
3427 * OTOH, in non-interactive shell this is useless
3428 * and only leads to extra job checks */
3429 if (pi->num_cmds == 0) {
3430 if (G_interactive_fd)
3431 goto check_jobs_and_continue;
3435 /* After analyzing all keywords and conditions, we decided
3436 * to execute this pipe. NB: have to do checkjobs(NULL)
3437 * after run_pipe to collect any background children,
3438 * even if list execution is to be stopped. */
3439 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3442 #if ENABLE_HUSH_LOOPS
3443 G.flag_break_continue = 0;
3445 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3447 /* We only ran a builtin: rcode is already known
3448 * and we don't need to wait for anything. */
3449 G.last_exitcode = rcode;
3450 debug_printf_exec(": builtin exitcode %d\n", rcode);
3451 check_and_run_traps(0);
3452 #if ENABLE_HUSH_LOOPS
3453 /* Was it "break" or "continue"? */
3454 if (G.flag_break_continue) {
3455 smallint fbc = G.flag_break_continue;
3456 /* We might fall into outer *loop*,
3457 * don't want to break it too */
3459 G.depth_break_continue--;
3460 if (G.depth_break_continue == 0)
3461 G.flag_break_continue = 0;
3462 /* else: e.g. "continue 2" should *break* once, *then* continue */
3463 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3464 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3465 goto check_jobs_and_break;
3466 /* "continue": simulate end of loop */
3471 } else if (pi->followup == PIPE_BG) {
3472 /* What does bash do with attempts to background builtins? */
3473 /* even bash 3.2 doesn't do that well with nested bg:
3474 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3475 * I'm NOT treating inner &'s as jobs */
3476 check_and_run_traps(0);
3478 if (G.run_list_level == 1)
3481 G.last_exitcode = rcode = EXIT_SUCCESS;
3482 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3485 if (G.run_list_level == 1 && G_interactive_fd) {
3486 /* Waits for completion, then fg's main shell */
3487 rcode = checkjobs_and_fg_shell(pi);
3488 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3489 check_and_run_traps(0);
3492 { /* This one just waits for completion */
3493 rcode = checkjobs(pi);
3494 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3495 check_and_run_traps(0);
3497 G.last_exitcode = rcode;
3501 /* Analyze how result affects subsequent commands */
3503 if (rword == RES_IF || rword == RES_ELIF)
3506 #if ENABLE_HUSH_LOOPS
3507 /* Beware of "while false; true; do ..."! */
3508 if (pi->next && pi->next->res_word == RES_DO) {
3509 if (rword == RES_WHILE) {
3511 /* "while false; do...done" - exitcode 0 */
3512 G.last_exitcode = rcode = EXIT_SUCCESS;
3513 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3514 goto check_jobs_and_break;
3517 if (rword == RES_UNTIL) {
3519 debug_printf_exec(": until expr is true: breaking\n");
3520 check_jobs_and_break:
3528 check_jobs_and_continue:
3533 //// if (G.ctrl_z_flag) {
3534 //// /* ctrl-Z forked somewhere in the past, we are the child,
3535 //// * and now we completed running the list. Exit. */
3541 //// if (!G.run_list_level && G_interactive_fd) {
3542 //// signal(SIGTSTP, SIG_IGN);
3543 //// signal(SIGINT, SIG_IGN);
3546 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3547 #if ENABLE_HUSH_LOOPS
3552 #if ENABLE_HUSH_CASE
3558 /* Select which version we will use */
3559 static int run_and_free_list(struct pipe *pi)
3562 debug_printf_exec("run_and_free_list entered\n");
3564 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3565 rcode = run_list(pi);
3567 /* free_pipe_list has the side effect of clearing memory.
3568 * In the long run that function can be merged with run_list,
3569 * but doing that now would hobble the debugging effort. */
3570 free_pipe_list(pi, /* indent: */ 0);
3571 debug_printf_exec("run_and_free_list return %d\n", rcode);
3576 static struct pipe *new_pipe(void)
3579 pi = xzalloc(sizeof(struct pipe));
3580 /*pi->followup = 0; - deliberately invalid value */
3581 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3585 /* Command (member of a pipe) is complete. The only possible error here
3586 * is out of memory, in which case xmalloc exits. */
3587 static int done_command(struct parse_context *ctx)
3589 /* The command is really already in the pipe structure, so
3590 * advance the pipe counter and make a new, null command. */
3591 struct pipe *pi = ctx->pipe;
3592 struct command *command = ctx->command;
3595 if (command->group == NULL
3596 && command->argv == NULL
3597 && command->redirects == NULL
3599 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3600 memset(command, 0, sizeof(*command)); /* paranoia */
3601 return pi->num_cmds;
3604 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3605 //debug_print_tree(ctx->list_head, 20);
3607 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3610 /* Only real trickiness here is that the uncommitted
3611 * command structure is not counted in pi->num_cmds. */
3612 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3613 command = &pi->cmds[pi->num_cmds];
3614 memset(command, 0, sizeof(*command));
3616 ctx->command = command;
3617 /* but ctx->pipe and ctx->list_head remain unchanged */
3619 return pi->num_cmds; /* used only for 0/nonzero check */
3622 static void done_pipe(struct parse_context *ctx, pipe_style type)
3626 debug_printf_parse("done_pipe entered, followup %d\n", type);
3627 /* Close previous command */
3628 not_null = done_command(ctx);
3629 ctx->pipe->followup = type;
3631 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3632 ctx->ctx_inverted = 0;
3633 ctx->pipe->res_word = ctx->ctx_res_w;
3636 /* Without this check, even just <enter> on command line generates
3637 * tree of three NOPs (!). Which is harmless but annoying.
3638 * IOW: it is safe to do it unconditionally.
3639 * RES_NONE case is for "for a in; do ..." (empty IN set)
3640 * and other cases to work. */
3643 || ctx->ctx_res_w == RES_FI
3644 || ctx->ctx_res_w == RES_DONE
3645 || ctx->ctx_res_w == RES_FOR
3646 || ctx->ctx_res_w == RES_IN
3647 || ctx->ctx_res_w == RES_ESAC
3651 debug_printf_parse("done_pipe: adding new pipe: "
3652 "not_null:%d ctx->ctx_res_w:%d\n",
3653 not_null, ctx->ctx_res_w);
3655 ctx->pipe->next = new_p;
3657 /* RES_THEN, RES_DO etc are "sticky" -
3658 * they remain set for commands inside if/while.
3659 * This is used to control execution.
3660 * RES_FOR and RES_IN are NOT sticky (needed to support
3661 * cases where variable or value happens to match a keyword):
3663 #if ENABLE_HUSH_LOOPS
3664 if (ctx->ctx_res_w == RES_FOR
3665 || ctx->ctx_res_w == RES_IN)
3666 ctx->ctx_res_w = RES_NONE;
3668 #if ENABLE_HUSH_CASE
3669 if (ctx->ctx_res_w == RES_MATCH)
3670 ctx->ctx_res_w = RES_CASEI;
3672 ctx->command = NULL; /* trick done_command below */
3673 /* Create the memory for command, roughly:
3674 * ctx->pipe->cmds = new struct command;
3675 * ctx->command = &ctx->pipe->cmds[0];
3678 //debug_print_tree(ctx->list_head, 10);
3680 debug_printf_parse("done_pipe return\n");
3683 static void initialize_context(struct parse_context *ctx)
3685 memset(ctx, 0, sizeof(*ctx));
3686 ctx->pipe = ctx->list_head = new_pipe();
3687 /* Create the memory for command, roughly:
3688 * ctx->pipe->cmds = new struct command;
3689 * ctx->command = &ctx->pipe->cmds[0];
3694 /* If a reserved word is found and processed, parse context is modified
3695 * and 1 is returned.
3698 struct reserved_combo {
3701 unsigned char assignment_flag;
3705 FLAG_END = (1 << RES_NONE ),
3707 FLAG_IF = (1 << RES_IF ),
3708 FLAG_THEN = (1 << RES_THEN ),
3709 FLAG_ELIF = (1 << RES_ELIF ),
3710 FLAG_ELSE = (1 << RES_ELSE ),
3711 FLAG_FI = (1 << RES_FI ),
3713 #if ENABLE_HUSH_LOOPS
3714 FLAG_FOR = (1 << RES_FOR ),
3715 FLAG_WHILE = (1 << RES_WHILE),
3716 FLAG_UNTIL = (1 << RES_UNTIL),
3717 FLAG_DO = (1 << RES_DO ),
3718 FLAG_DONE = (1 << RES_DONE ),
3719 FLAG_IN = (1 << RES_IN ),
3721 #if ENABLE_HUSH_CASE
3722 FLAG_MATCH = (1 << RES_MATCH),
3723 FLAG_ESAC = (1 << RES_ESAC ),
3725 FLAG_START = (1 << RES_XXXX ),
3728 static const struct reserved_combo* match_reserved_word(o_string *word)
3730 /* Mostly a list of accepted follow-up reserved words.
3731 * FLAG_END means we are done with the sequence, and are ready
3732 * to turn the compound list into a command.
3733 * FLAG_START means the word must start a new compound list.
3735 static const struct reserved_combo reserved_list[] = {
3737 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3738 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3739 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3740 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3741 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3742 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3744 #if ENABLE_HUSH_LOOPS
3745 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3746 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3747 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3748 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3749 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3750 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3752 #if ENABLE_HUSH_CASE
3753 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3754 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3757 const struct reserved_combo *r;
3759 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3760 if (strcmp(word->data, r->literal) == 0)
3765 static int reserved_word(o_string *word, struct parse_context *ctx)
3767 #if ENABLE_HUSH_CASE
3768 static const struct reserved_combo reserved_match = {
3769 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3772 const struct reserved_combo *r;
3774 r = match_reserved_word(word);
3778 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3779 #if ENABLE_HUSH_CASE
3780 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3781 /* "case word IN ..." - IN part starts first match part */
3782 r = &reserved_match;
3785 if (r->flag == 0) { /* '!' */
3786 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3787 syntax("! ! command");
3788 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3790 ctx->ctx_inverted = 1;
3793 if (r->flag & FLAG_START) {
3794 struct parse_context *old;
3795 old = xmalloc(sizeof(*old));
3796 debug_printf_parse("push stack %p\n", old);
3797 *old = *ctx; /* physical copy */
3798 initialize_context(ctx);
3800 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3802 ctx->ctx_res_w = RES_SNTX;
3805 ctx->ctx_res_w = r->res;
3806 ctx->old_flag = r->flag;
3807 if (ctx->old_flag & FLAG_END) {
3808 struct parse_context *old;
3809 done_pipe(ctx, PIPE_SEQ);
3810 debug_printf_parse("pop stack %p\n", ctx->stack);
3812 old->command->group = ctx->list_head;
3813 old->command->grp_type = GRP_NORMAL;
3815 o_addstr(&old->as_string, ctx->as_string.data);
3816 o_free_unsafe(&ctx->as_string);
3817 old->command->group_as_string = xstrdup(old->as_string.data);
3818 debug_printf_parse("pop, remembering as:'%s'\n",
3819 old->command->group_as_string);
3821 *ctx = *old; /* physical copy */
3824 word->o_assignment = r->assignment_flag;
3829 /* Word is complete, look at it and update parsing context.
3830 * Normal return is 0. Syntax errors return 1.
3831 * Note: on return, word is reset, but not o_free'd!
3833 static int done_word(o_string *word, struct parse_context *ctx)
3835 struct command *command = ctx->command;
3837 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3838 if (word->length == 0 && word->o_quoted == 0) {
3839 debug_printf_parse("done_word return 0: true null, ignored\n");
3842 /* If this word wasn't an assignment, next ones definitely
3843 * can't be assignments. Even if they look like ones. */
3844 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3845 && word->o_assignment != WORD_IS_KEYWORD
3847 word->o_assignment = NOT_ASSIGNMENT;
3849 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3850 command->assignment_cnt++;
3851 word->o_assignment = MAYBE_ASSIGNMENT;
3854 if (ctx->pending_redirect) {
3855 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3856 * only if run as "bash", not "sh" */
3857 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3859 * ...the word that follows the redirection operator
3860 * shall be subjected to tilde expansion, parameter expansion,
3861 * command substitution, arithmetic expansion, and quote
3862 * removal. Pathname expansion shall not be performed
3863 * on the word by a non-interactive shell; an interactive
3864 * shell may perform it, but shall do so only when
3865 * the expansion would result in one word."
3867 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3868 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
3871 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3873 word->o_assignment = NOT_ASSIGNMENT;
3874 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3876 /* "{ echo foo; } echo bar" - bad */
3877 /* NB: bash allows e.g.:
3878 * if true; then { echo foo; } fi
3879 * while if false; then false; fi do break; done
3881 * while if false; then false; fi; do; break; done
3883 if (command->group) {
3885 debug_printf_parse("done_word return 1: syntax error, "
3886 "groups and arglists don't mix\n");
3890 #if ENABLE_HUSH_CASE
3891 if (ctx->ctx_dsemicolon
3892 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3894 /* already done when ctx_dsemicolon was set to 1: */
3895 /* ctx->ctx_res_w = RES_MATCH; */
3896 ctx->ctx_dsemicolon = 0;
3899 if (!command->argv /* if it's the first word... */
3900 #if ENABLE_HUSH_LOOPS
3901 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3902 && ctx->ctx_res_w != RES_IN
3905 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3906 if (reserved_word(word, ctx)) {
3908 debug_printf_parse("done_word return %d\n",
3909 (ctx->ctx_res_w == RES_SNTX));
3910 return (ctx->ctx_res_w == RES_SNTX);
3914 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
3915 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3916 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3917 /* (otherwise it's known to be not empty and is already safe) */
3919 /* exclude "$@" - it can expand to no word despite "" */
3920 char *p = word->data;
3921 while (p[0] == SPECIAL_VAR_SYMBOL
3922 && (p[1] & 0x7f) == '@'
3923 && p[2] == SPECIAL_VAR_SYMBOL
3927 if (p == word->data || p[0] != '\0') {
3928 /* saw no "$@", or not only "$@" but some
3929 * real text is there too */
3930 /* insert "empty variable" reference, this makes
3931 * e.g. "", $empty"" etc to not disappear */
3932 o_addchr(word, SPECIAL_VAR_SYMBOL);
3933 o_addchr(word, SPECIAL_VAR_SYMBOL);
3936 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3937 debug_print_strings("word appended to argv", command->argv);
3941 ctx->pending_redirect = NULL;
3943 #if ENABLE_HUSH_LOOPS
3944 /* Force FOR to have just one word (variable name) */
3945 /* NB: basically, this makes hush see "for v in ..." syntax as if
3946 * as it is "for v; in ...". FOR and IN become two pipe structs
3948 if (ctx->ctx_res_w == RES_FOR) {
3949 //TODO: check that command->argv[0] is a valid variable name!
3950 done_pipe(ctx, PIPE_SEQ);
3953 #if ENABLE_HUSH_CASE
3954 /* Force CASE to have just one word */
3955 if (ctx->ctx_res_w == RES_CASE) {
3956 done_pipe(ctx, PIPE_SEQ);
3959 debug_printf_parse("done_word return 0\n");
3964 /* Peek ahead in the input to find out if we have a "&n" construct,
3965 * as in "2>&1", that represents duplicating a file descriptor.
3966 * Return: REDIRFD_CLOSE (-3) if >&- "close fd" construct is seen,
3967 * -2 (syntax error), -1 if no & was seen, or the number found.
3970 #define redirect_dup_num(as_string, input) \
3971 redirect_dup_num(input)
3973 static int redirect_dup_num(o_string *as_string, struct in_str *input)
3981 ch = i_getch(input); /* get the & */
3982 nommu_addchr(as_string, ch);
3985 ch = i_getch(input);
3986 nommu_addchr(as_string, ch);
3987 return REDIRFD_CLOSE;
3991 while (ch != EOF && isdigit(ch)) {
3992 d = d*10 + (ch-'0');
3994 ch = i_getch(input);
3995 nommu_addchr(as_string, ch);
4000 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4002 bb_error_msg("ambiguous redirect");
4006 /* Return code is 0 normally, 1 if a syntax error is detected
4008 static int parse_redirect(struct parse_context *ctx,
4011 struct in_str *input)
4013 struct command *command = ctx->command;
4014 struct redir_struct *redir;
4015 struct redir_struct **redirp;
4019 if (style != REDIRECT_HEREDOC) {
4020 /* Check for a '2>&1' type redirect */
4021 dup_num = redirect_dup_num(&ctx->as_string, input);
4023 return 1; /* syntax error */
4025 int ch = i_peek(input);
4026 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4027 if (dup_num) { /* <<-... */
4028 ch = i_getch(input);
4029 nommu_addchr(&ctx->as_string, ch);
4032 /* <<[-] word is the same as <<[-]word */
4033 while (ch == ' ' || ch == '\t') {
4034 ch = i_getch(input);
4035 nommu_addchr(&ctx->as_string, ch);
4040 if (style == REDIRECT_OVERWRITE && dup_num == -1) {
4041 int ch = i_peek(input);
4043 /* >|FILE redirect ("clobbering" >).
4044 * Since we do not support "set -o noclobber" yet,
4045 * >| and > are the same for now. Just eat |.
4047 ch = i_getch(input);
4048 nommu_addchr(&ctx->as_string, ch);
4052 /* Create a new redir_struct and append it to the linked list */
4053 redirp = &command->redirects;
4054 while ((redir = *redirp) != NULL) {
4055 redirp = &(redir->next);
4057 *redirp = redir = xzalloc(sizeof(*redir));
4058 /* redir->next = NULL; */
4059 /* redir->rd_filename = NULL; */
4060 redir->rd_type = style;
4061 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4063 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4064 redir_table[style].descrip);
4066 redir->rd_dup = dup_num;
4067 if (style != REDIRECT_HEREDOC && dup_num != -1) {
4068 /* Erik had a check here that the file descriptor in question
4069 * is legit; I postpone that to "run time"
4070 * A "-" representation of "close me" shows up as a -3 here */
4071 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4072 redir->rd_fd, redir->rd_dup);
4074 /* Set ctx->pending_redirect, so we know what to do at the
4075 * end of the next parsed word. */
4076 ctx->pending_redirect = redir;
4081 /* If a redirect is immediately preceded by a number, that number is
4082 * supposed to tell which file descriptor to redirect. This routine
4083 * looks for such preceding numbers. In an ideal world this routine
4084 * needs to handle all the following classes of redirects...
4085 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4086 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4087 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4088 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4090 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4092 * ... If n is quoted, the number shall not be recognized as part of
4093 * the redirection expression. For example:
4095 * writes the character 2 into file a"
4096 * We are getting it right by setting ->o_quoted on any \<char>
4098 * A -1 return means no valid number was found,
4099 * the caller should use the appropriate default for this redirection.
4101 static int redirect_opt_num(o_string *o)
4105 if (o->data == NULL)
4107 num = bb_strtou(o->data, NULL, 10);
4108 if (errno || num < 0)
4115 #define fetch_till_str(as_string, input, word, skip_tabs) \
4116 fetch_till_str(input, word, skip_tabs)
4118 static char *fetch_till_str(o_string *as_string,
4119 struct in_str *input,
4123 o_string heredoc = NULL_O_STRING;
4129 ch = i_getch(input);
4130 nommu_addchr(as_string, ch);
4132 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4133 heredoc.data[past_EOL] = '\0';
4134 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4135 return heredoc.data;
4138 o_addchr(&heredoc, ch);
4139 past_EOL = heredoc.length;
4142 ch = i_getch(input);
4143 nommu_addchr(as_string, ch);
4144 } while (skip_tabs && ch == '\t');
4145 } while (ch == '\n');
4148 o_free_unsafe(&heredoc);
4151 o_addchr(&heredoc, ch);
4152 nommu_addchr(as_string, ch);
4156 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4157 * and load them all. There should be exactly heredoc_cnt of them.
4159 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4161 struct pipe *pi = ctx->list_head;
4165 struct command *cmd = pi->cmds;
4167 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4169 cmd->argv ? cmd->argv[0] : "NONE");
4170 for (i = 0; i < pi->num_cmds; i++) {
4171 struct redir_struct *redir = cmd->redirects;
4173 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4174 i, cmd->argv ? cmd->argv[0] : "NONE");
4176 if (redir->rd_type == REDIRECT_HEREDOC) {
4179 if (heredoc_cnt <= 0) {
4180 syntax("heredoc BUG 1");
4181 return 1; /* error */
4183 redir->rd_type = REDIRECT_HEREDOC2;
4184 /* redir->dup is (ab)used to indicate <<- */
4185 p = fetch_till_str(&ctx->as_string, input,
4186 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4188 syntax("unexpected EOF in here document");
4191 free(redir->rd_filename);
4192 redir->rd_filename = p;
4195 redir = redir->next;
4201 /* Should be 0. If it isn't, it's a parse error */
4203 syntax("heredoc BUG 2");
4209 #define parse_stream(pstring, input, end_trigger) \
4210 parse_stream(input, end_trigger)
4212 static struct pipe *parse_stream(char **pstring,
4213 struct in_str *input,
4215 static void parse_and_run_string(const char *s);
4217 #if ENABLE_HUSH_TICK
4218 static FILE *generate_stream_from_string(const char *s)
4221 int pid, channel[2];
4224 pid = BB_MMU ? fork() : vfork();
4226 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4228 if (pid == 0) { /* child */
4229 disable_restore_tty_pgrp_on_exit();
4230 /* Process substitution is not considered to be usual
4231 * 'command execution'.
4232 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4239 close(channel[0]); /* NB: close _first_, then move fd! */
4240 xmove_fd(channel[1], 1);
4241 /* Prevent it from trying to handle ctrl-z etc */
4242 USE_HUSH_JOB(G.run_list_level = 1;)
4244 reset_traps_to_defaults();
4245 parse_and_run_string(s);
4246 _exit(G.last_exitcode);
4248 /* We re-execute after vfork on NOMMU. This makes this script safe:
4249 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4250 * huge=`cat BIG` # was blocking here forever
4253 re_execute_shell(s, 0);
4258 enable_restore_tty_pgrp_on_exit();
4259 clean_up_after_re_execute();
4261 pf = fdopen(channel[0], "r");
4265 /* Return code is exit status of the process that is run. */
4266 static int process_command_subs(o_string *dest, const char *s)
4269 struct in_str pipe_str;
4272 pf = generate_stream_from_string(s);
4275 close_on_exec_on(fileno(pf));
4277 /* Now send results of command back into original context */
4278 setup_file_in_str(&pipe_str, pf);
4280 while ((ch = i_getch(&pipe_str)) != EOF) {
4286 o_addchr(dest, '\n');
4289 o_addQchr(dest, ch);
4292 debug_printf("done reading from pipe, pclose()ing\n");
4293 /* Note: we got EOF, and we just close the read end of the pipe.
4294 * We do not wait for the `cmd` child to terminate. bash and ash do.
4296 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4297 * `false`; echo $? - bash outputs "1"
4300 debug_printf("closed FILE from child. return 0\n");
4305 static int parse_group(o_string *dest, struct parse_context *ctx,
4306 struct in_str *input, int ch)
4308 /* dest contains characters seen prior to ( or {.
4309 * Typically it's empty, but for function defs,
4310 * it contains function name (without '()'). */
4311 struct pipe *pipe_list;
4313 struct command *command = ctx->command;
4315 debug_printf_parse("parse_group entered\n");
4316 #if ENABLE_HUSH_FUNCTIONS
4317 if (ch == 'F') { /* function definition? */
4318 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4319 //command->fname = dest->data;
4320 command->grp_type = GRP_FUNCTION;
4321 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4322 memset(dest, 0, sizeof(*dest));
4325 if (command->argv /* word [word](... */
4326 || dest->length /* word(... */
4327 || dest->o_quoted /* ""(... */
4330 debug_printf_parse("parse_group return 1: "
4331 "syntax error, groups and arglists don't mix\n");
4337 command->grp_type = GRP_SUBSHELL;
4341 char *as_string = NULL;
4343 pipe_list = parse_stream(&as_string, input, endch);
4346 o_addstr(&ctx->as_string, as_string);
4348 /* empty ()/{} or parse error? */
4349 if (!pipe_list || pipe_list == ERR_PTR) {
4354 debug_printf_parse("parse_group return 1: "
4355 "parse_stream returned %p\n", pipe_list);
4358 command->group = pipe_list;
4360 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4361 command->group_as_string = as_string;
4362 debug_printf_parse("end of group, remembering as:'%s'\n",
4363 command->group_as_string);
4366 debug_printf_parse("parse_group return 0\n");
4368 /* command remains "open", available for possible redirects */
4371 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4372 /* Subroutines for copying $(...) and `...` things */
4373 static void add_till_backquote(o_string *dest, struct in_str *input);
4375 static void add_till_single_quote(o_string *dest, struct in_str *input)
4378 int ch = i_getch(input);
4386 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4387 static void add_till_double_quote(o_string *dest, struct in_str *input)
4390 int ch = i_getch(input);
4393 if (ch == '\\') { /* \x. Copy both chars. */
4395 ch = i_getch(input);
4401 add_till_backquote(dest, input);
4405 //if (ch == '$') ...
4408 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4410 * "Within the backquoted style of command substitution, backslash
4411 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4412 * The search for the matching backquote shall be satisfied by the first
4413 * backquote found without a preceding backslash; during this search,
4414 * if a non-escaped backquote is encountered within a shell comment,
4415 * a here-document, an embedded command substitution of the $(command)
4416 * form, or a quoted string, undefined results occur. A single-quoted
4417 * or double-quoted string that begins, but does not end, within the
4418 * "`...`" sequence produces undefined results."
4420 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4422 static void add_till_backquote(o_string *dest, struct in_str *input)
4425 int ch = i_getch(input);
4428 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
4429 int ch2 = i_getch(input);
4430 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4439 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4440 * quoting and nested ()s.
4441 * "With the $(command) style of command substitution, all characters
4442 * following the open parenthesis to the matching closing parenthesis
4443 * constitute the command. Any valid shell script can be used for command,
4444 * except a script consisting solely of redirections which produces
4445 * unspecified results."
4447 * echo $(echo '(TEST)' BEST) (TEST) BEST
4448 * echo $(echo 'TEST)' BEST) TEST) BEST
4449 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4451 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4455 int ch = i_getch(input);
4464 if (i_peek(input) == ')') {
4472 add_till_single_quote(dest, input);
4477 add_till_double_quote(dest, input);
4481 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
4482 ch = i_getch(input);
4490 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4492 /* Return code: 0 for OK, 1 for syntax error */
4494 #define handle_dollar(as_string, dest, input) \
4495 handle_dollar(dest, input)
4497 static int handle_dollar(o_string *as_string,
4499 struct in_str *input)
4502 int ch = i_peek(input); /* first character after the $ */
4503 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4505 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4507 ch = i_getch(input);
4508 nommu_addchr(as_string, ch);
4510 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4512 debug_printf_parse(": '%c'\n", ch);
4513 o_addchr(dest, ch | quote_mask);
4516 if (!isalnum(ch) && ch != '_')
4518 ch = i_getch(input);
4519 nommu_addchr(as_string, ch);
4521 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4522 } else if (isdigit(ch)) {
4524 ch = i_getch(input);
4525 nommu_addchr(as_string, ch);
4526 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4527 debug_printf_parse(": '%c'\n", ch);
4528 o_addchr(dest, ch | quote_mask);
4529 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4530 } else switch (ch) {
4532 case '!': /* last bg pid */
4533 case '?': /* last exit code */
4534 case '#': /* number of args */
4535 case '*': /* args */
4536 case '@': /* args */
4537 goto make_one_char_var;
4539 bool first_char, all_digits;
4541 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4542 ch = i_getch(input);
4543 nommu_addchr(as_string, ch);
4544 /* XXX maybe someone will try to escape the '}' */
4549 ch = i_getch(input);
4550 nommu_addchr(as_string, ch);
4556 /* ${#var}: length of var contents */
4558 else if (isdigit(ch)) {
4565 && ( (all_digits && !isdigit(ch))
4566 || (!all_digits && !isalnum(ch) && ch != '_')
4569 /* handle parameter expansions
4570 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4575 case ':': /* null modifier */
4576 if (expansion == 0) {
4577 debug_printf_parse(": null modifier\n");
4582 case '#': /* remove prefix */
4583 case '%': /* remove suffix */
4584 if (expansion == 0) {
4585 debug_printf_parse(": remove suffix/prefix\n");
4590 case '-': /* default value */
4591 case '=': /* assign default */
4592 case '+': /* alternative */
4593 case '?': /* error indicate */
4594 debug_printf_parse(": parameter expansion\n");
4599 syntax("unterminated ${name}");
4600 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4605 debug_printf_parse(": '%c'\n", ch);
4606 o_addchr(dest, ch | quote_mask);
4610 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4613 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4618 ch = i_getch(input);
4619 nommu_addchr(as_string, ch);
4620 # if ENABLE_SH_MATH_SUPPORT
4621 if (i_peek(input) == '(') {
4622 ch = i_getch(input);
4623 nommu_addchr(as_string, ch);
4624 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4625 o_addchr(dest, /*quote_mask |*/ '+');
4629 add_till_closing_paren(dest, input, true);
4632 o_addstr(as_string, dest->data + pos);
4633 o_addchr(as_string, ')');
4634 o_addchr(as_string, ')');
4637 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4641 # if ENABLE_HUSH_TICK
4642 //int pos = dest->length;
4643 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4644 o_addchr(dest, quote_mask | '`');
4648 add_till_closing_paren(dest, input, false);
4651 o_addstr(as_string, dest->data + pos);
4652 o_addchr(as_string, '`');
4655 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4656 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4662 ch = i_getch(input);
4663 nommu_addchr(as_string, ch);
4665 if (isalnum(ch)) { /* it's $_name or $_123 */
4671 /* $_ Shell or shell script name; or last cmd name */
4672 /* $- Option flags set by set builtin or shell options (-i etc) */
4674 o_addQchr(dest, '$');
4676 debug_printf_parse("handle_dollar return 0\n");
4681 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4682 parse_stream_dquoted(dest, input, dquote_end)
4684 static int parse_stream_dquoted(o_string *as_string,
4686 struct in_str *input,
4693 ch = i_getch(input);
4695 nommu_addchr(as_string, ch);
4696 if (ch == dquote_end) { /* may be only '"' or EOF */
4697 if (dest->o_assignment == NOT_ASSIGNMENT)
4698 dest->o_escape ^= 1;
4699 debug_printf_parse("parse_stream_dquoted return 0\n");
4702 /* note: can't move it above ch == dquote_end check! */
4704 syntax("unterminated \"");
4705 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4710 next = i_peek(input);
4712 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4713 ch, ch, dest->o_escape);
4717 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4721 * "The backslash retains its special meaning [in "..."]
4722 * only when followed by one of the following characters:
4723 * $, `, ", \, or <newline>. A double quote may be quoted
4724 * within double quotes by preceding it with a backslash.
4725 * If enabled, history expansion will be performed unless
4726 * an ! appearing in double quotes is escaped using
4727 * a backslash. The backslash preceding the ! is not removed."
4729 if (strchr("$`\"\\", next) != NULL) {
4730 o_addqchr(dest, i_getch(input));
4732 o_addqchr(dest, '\\');
4737 if (handle_dollar(as_string, dest, input) != 0) {
4738 debug_printf_parse("parse_stream_dquoted return 1: "
4739 "handle_dollar returned non-0\n");
4744 #if ENABLE_HUSH_TICK
4746 //int pos = dest->length;
4747 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4748 o_addchr(dest, 0x80 | '`');
4749 add_till_backquote(dest, input);
4750 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4751 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4755 o_addQchr(dest, ch);
4757 && (dest->o_assignment == MAYBE_ASSIGNMENT
4758 || dest->o_assignment == WORD_IS_KEYWORD)
4759 && is_assignment(dest->data)
4761 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4767 * Scan input until EOF or end_trigger char.
4768 * Return a list of pipes to execute, or NULL on EOF
4769 * or if end_trigger character is met.
4770 * On syntax error, exit is shell is not interactive,
4771 * reset parsing machinery and start parsing anew,
4772 * or return ERR_PTR.
4774 static struct pipe *parse_stream(char **pstring,
4775 struct in_str *input,
4778 struct parse_context ctx;
4779 o_string dest = NULL_O_STRING;
4783 /* Double-quote state is handled in the state variable is_in_dquote.
4784 * A single-quote triggers a bypass of the main loop until its mate is
4785 * found. When recursing, quote state is passed in via dest->o_escape.
4787 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4788 end_trigger ? : 'X');
4790 G.ifs = get_local_var_value("IFS");
4795 #if ENABLE_HUSH_INTERACTIVE
4796 input->promptmode = 0; /* PS1 */
4798 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4799 initialize_context(&ctx);
4804 const char *is_special;
4808 redir_type redir_style;
4811 /* dest.o_quoted = 1; - already is (see below) */
4812 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4815 /* We reached closing '"' */
4818 ch = i_getch(input);
4819 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4820 ch, ch, dest.o_escape);
4825 syntax("unterminated here document");
4828 if (done_word(&dest, &ctx)) {
4832 done_pipe(&ctx, PIPE_SEQ);
4834 /* If we got nothing... */
4835 // TODO: test script consisting of just "&"
4836 if (pi->num_cmds == 0
4837 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4839 free_pipe_list(pi, 0);
4842 debug_printf_parse("parse_stream return %p\n", pi);
4844 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4846 *pstring = ctx.as_string.data;
4848 o_free_unsafe(&ctx.as_string);
4852 nommu_addchr(&ctx.as_string, ch);
4853 is_ifs = strchr(G.ifs, ch);
4854 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4855 "\\$\"" USE_HUSH_TICK("`") /* always special */
4858 if (!is_special && !is_ifs) { /* ordinary char */
4859 o_addQchr(&dest, ch);
4860 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4861 || dest.o_assignment == WORD_IS_KEYWORD)
4863 && is_assignment(dest.data)
4865 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4871 if (done_word(&dest, &ctx)) {
4875 #if ENABLE_HUSH_CASE
4876 /* "case ... in <newline> word) ..." -
4877 * newlines are ignored (but ';' wouldn't be) */
4878 if (ctx.command->argv == NULL
4879 && ctx.ctx_res_w == RES_MATCH
4884 /* Treat newline as a command separator. */
4885 done_pipe(&ctx, PIPE_SEQ);
4886 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4888 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4893 dest.o_assignment = MAYBE_ASSIGNMENT;
4895 /* note: if (is_ifs) continue;
4896 * will still trigger for us */
4899 if (end_trigger && end_trigger == ch
4900 && (heredoc_cnt == 0 || end_trigger != ';')
4902 //TODO: disallow "{ cmd }" without semicolon
4904 /* This is technically valid:
4905 * { cat <<HERE; }; echo Ok
4910 * but we don't support this.
4911 * We require heredoc to be in enclosing {}/(),
4914 syntax("unterminated here document");
4917 if (done_word(&dest, &ctx)) {
4920 done_pipe(&ctx, PIPE_SEQ);
4921 dest.o_assignment = MAYBE_ASSIGNMENT;
4922 /* Do we sit outside of any if's, loops or case's? */
4924 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4926 debug_printf_parse("parse_stream return %p: "
4927 "end_trigger char found\n",
4931 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4933 *pstring = ctx.as_string.data;
4935 o_free_unsafe(&ctx.as_string);
4937 return ctx.list_head;
4943 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4944 /* ch is a special char and thus this word
4945 * cannot be an assignment */
4946 dest.o_assignment = NOT_ASSIGNMENT;
4951 next = i_peek(input);
4956 if (dest.length == 0) {
4959 if (ch == EOF || ch == '\n')
4962 /* note: we do not add it to &ctx.as_string */
4964 nommu_addchr(&ctx.as_string, '\n');
4966 o_addQchr(&dest, ch);
4974 o_addchr(&dest, '\\');
4975 ch = i_getch(input);
4976 nommu_addchr(&ctx.as_string, ch);
4977 o_addchr(&dest, ch);
4978 /* Example: echo Hello \2>file
4979 * we need to know that word 2 is quoted */
4983 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
4984 debug_printf_parse("parse_stream parse error: "
4985 "handle_dollar returned non-0\n");
4992 ch = i_getch(input);
4994 syntax("unterminated '");
4997 nommu_addchr(&ctx.as_string, ch);
5000 if (dest.o_assignment == NOT_ASSIGNMENT)
5001 o_addqchr(&dest, ch);
5003 o_addchr(&dest, ch);
5008 is_in_dquote ^= 1; /* invert */
5009 if (dest.o_assignment == NOT_ASSIGNMENT)
5012 #if ENABLE_HUSH_TICK
5014 //int pos = dest.length;
5015 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5016 o_addchr(&dest, '`');
5017 add_till_backquote(&dest, input);
5018 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5019 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5024 redir_fd = redirect_opt_num(&dest);
5025 if (done_word(&dest, &ctx)) {
5028 redir_style = REDIRECT_OVERWRITE;
5030 redir_style = REDIRECT_APPEND;
5031 ch = i_getch(input);
5032 nommu_addchr(&ctx.as_string, ch);
5035 else if (next == '(') {
5036 syntax(">(process) not supported");
5040 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5044 redir_fd = redirect_opt_num(&dest);
5045 if (done_word(&dest, &ctx)) {
5048 redir_style = REDIRECT_INPUT;
5050 redir_style = REDIRECT_HEREDOC;
5052 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5053 ch = i_getch(input);
5054 nommu_addchr(&ctx.as_string, ch);
5055 } else if (next == '>') {
5056 redir_style = REDIRECT_IO;
5057 ch = i_getch(input);
5058 nommu_addchr(&ctx.as_string, ch);
5061 else if (next == '(') {
5062 syntax("<(process) not supported");
5066 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5070 #if ENABLE_HUSH_CASE
5073 if (done_word(&dest, &ctx)) {
5076 done_pipe(&ctx, PIPE_SEQ);
5077 #if ENABLE_HUSH_CASE
5078 /* Eat multiple semicolons, detect
5079 * whether it means something special */
5084 ch = i_getch(input);
5085 nommu_addchr(&ctx.as_string, ch);
5086 if (ctx.ctx_res_w == RES_CASEI) {
5087 ctx.ctx_dsemicolon = 1;
5088 ctx.ctx_res_w = RES_MATCH;
5094 /* We just finished a cmd. New one may start
5095 * with an assignment */
5096 dest.o_assignment = MAYBE_ASSIGNMENT;
5099 if (done_word(&dest, &ctx)) {
5103 ch = i_getch(input);
5104 nommu_addchr(&ctx.as_string, ch);
5105 done_pipe(&ctx, PIPE_AND);
5107 done_pipe(&ctx, PIPE_BG);
5111 if (done_word(&dest, &ctx)) {
5114 #if ENABLE_HUSH_CASE
5115 if (ctx.ctx_res_w == RES_MATCH)
5116 break; /* we are in case's "word | word)" */
5118 if (next == '|') { /* || */
5119 ch = i_getch(input);
5120 nommu_addchr(&ctx.as_string, ch);
5121 done_pipe(&ctx, PIPE_OR);
5123 /* we could pick up a file descriptor choice here
5124 * with redirect_opt_num(), but bash doesn't do it.
5125 * "echo foo 2| cat" yields "foo 2". */
5130 #if ENABLE_HUSH_CASE
5131 /* "case... in [(]word)..." - skip '(' */
5132 if (ctx.ctx_res_w == RES_MATCH
5133 && ctx.command->argv == NULL /* not (word|(... */
5134 && dest.length == 0 /* not word(... */
5135 && dest.o_quoted == 0 /* not ""(... */
5140 #if ENABLE_HUSH_FUNCTIONS
5141 if (dest.length != 0 /* not just () but word() */
5142 && dest.o_quoted == 0 /* not a"b"c() */
5143 && ctx.command->argv == NULL /* it's the first word */
5144 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5145 && i_peek(input) == ')'
5146 && !match_reserved_word(&dest)
5148 bb_error_msg("seems like a function definition");
5150 //if !BB_MMU o_addchr(&ctx.as_string...
5152 //TODO: do it properly.
5153 ch = i_getch(input);
5154 } while (ch == ' ' || ch == '\n');
5156 syntax("was expecting {");
5159 ch = 'F'; /* magic value */
5163 if (parse_group(&dest, &ctx, input, ch) != 0) {
5168 #if ENABLE_HUSH_CASE
5169 if (ctx.ctx_res_w == RES_MATCH)
5173 /* proper use of this character is caught by end_trigger:
5174 * if we see {, we call parse_group(..., end_trigger='}')
5175 * and it will match } earlier (not here). */
5176 syntax("unexpected } or )");
5180 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5186 struct parse_context *pctx;
5187 IF_HAS_KEYWORDS(struct parse_context *p2;)
5189 /* Clean up allocated tree.
5190 * Samples for finding leaks on syntax error recovery path.
5191 * Run them from interactive shell, watch pmap `pidof hush`.
5192 * while if false; then false; fi do break; done
5194 * while if false; then false; fi; do break; fi
5195 * Samples to catch leaks at execution:
5196 * while if (true | {true;}); then echo ok; fi; do break; done
5197 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5201 /* Update pipe/command counts,
5202 * otherwise freeing may miss some */
5203 done_pipe(pctx, PIPE_SEQ);
5204 debug_printf_clean("freeing list %p from ctx %p\n",
5205 pctx->list_head, pctx);
5206 debug_print_tree(pctx->list_head, 0);
5207 free_pipe_list(pctx->list_head, 0);
5208 debug_printf_clean("freed list %p\n", pctx->list_head);
5210 o_free_unsafe(&pctx->as_string);
5212 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5216 IF_HAS_KEYWORDS(pctx = p2;)
5217 } while (HAS_KEYWORDS && pctx);
5218 /* Free text, clear all dest fields */
5220 /* If we are not in top-level parse, we return,
5221 * our caller will propagate error.
5223 if (end_trigger != ';') {
5230 /* Discard cached input, force prompt */
5232 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5237 /* Executing from string: eval, sh -c '...'
5238 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5239 * end_trigger controls how often we stop parsing
5240 * NUL: parse all, execute, return
5241 * ';': parse till ';' or newline, execute, repeat till EOF
5243 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5246 struct pipe *pipe_list;
5248 pipe_list = parse_stream(NULL, inp, end_trigger);
5249 if (!pipe_list) /* EOF */
5251 debug_print_tree(pipe_list, 0);
5252 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5253 run_and_free_list(pipe_list);
5257 static void parse_and_run_string(const char *s)
5259 struct in_str input;
5260 setup_string_in_str(&input, s);
5261 parse_and_run_stream(&input, '\0');
5264 static void parse_and_run_file(FILE *f)
5266 struct in_str input;
5267 setup_file_in_str(&input, f);
5268 parse_and_run_stream(&input, ';');
5271 /* Called a few times only (or even once if "sh -c") */
5272 static void block_signals(int second_time)
5277 mask = (1 << SIGQUIT);
5278 if (G_interactive_fd) {
5282 //TODO | (1 << SIGHUP)
5284 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5289 G.non_DFL_mask = mask;
5292 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5296 sigaddset(&G.blocked_set, sig);
5300 sigdelset(&G.blocked_set, SIGCHLD);
5302 sigprocmask(SIG_SETMASK, &G.blocked_set,
5303 second_time ? NULL : &G.inherited_set);
5304 /* POSIX allows shell to re-enable SIGCHLD
5305 * even if it was SIG_IGN on entry */
5306 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5308 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5313 static void maybe_set_to_sigexit(int sig)
5315 void (*handler)(int);
5316 /* non_DFL_mask'ed signals are, well, masked,
5317 * no need to set handler for them.
5319 if (!((G.non_DFL_mask >> sig) & 1)) {
5320 handler = signal(sig, sigexit);
5321 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5322 signal(sig, handler);
5325 /* Set handlers to restore tty pgrp and exit */
5326 static void set_fatal_handlers(void)
5328 /* We _must_ restore tty pgrp on fatal signals */
5330 maybe_set_to_sigexit(SIGILL );
5331 maybe_set_to_sigexit(SIGFPE );
5332 maybe_set_to_sigexit(SIGBUS );
5333 maybe_set_to_sigexit(SIGSEGV);
5334 maybe_set_to_sigexit(SIGTRAP);
5335 } /* else: hush is perfect. what SEGV? */
5336 maybe_set_to_sigexit(SIGABRT);
5337 /* bash 3.2 seems to handle these just like 'fatal' ones */
5338 maybe_set_to_sigexit(SIGPIPE);
5339 maybe_set_to_sigexit(SIGALRM);
5340 //TODO: disable and move down when proper SIGHUP handling is added
5341 maybe_set_to_sigexit(SIGHUP );
5342 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5343 * if we aren't interactive... but in this case
5344 * we never want to restore pgrp on exit, and this fn is not called */
5345 /*maybe_set_to_sigexit(SIGTERM);*/
5346 /*maybe_set_to_sigexit(SIGINT );*/
5350 static int set_mode(const char cstate, const char mode)
5352 int state = (cstate == '-' ? 1 : 0);
5354 case 'n': G.fake_mode = state; break;
5355 case 'x': /*G.debug_mode = state;*/ break;
5356 default: return EXIT_FAILURE;
5358 return EXIT_SUCCESS;
5361 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5362 int hush_main(int argc, char **argv)
5364 static const struct variable const_shell_ver = {
5366 .varstr = (char*)hush_version_str,
5367 .max_len = 1, /* 0 can provoke free(name) */
5371 int signal_mask_is_inited = 0;
5374 struct variable *cur_var;
5377 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5378 G.last_exitcode = EXIT_SUCCESS;
5380 G.argv0_for_re_execing = argv[0];
5382 /* Deal with HUSH_VERSION */
5383 G.shell_ver = const_shell_ver; /* copying struct here */
5384 G.top_var = &G.shell_ver;
5385 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5386 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5387 /* Initialize our shell local variables with the values
5388 * currently living in the environment */
5389 cur_var = G.top_var;
5392 char *value = strchr(*e, '=');
5393 if (value) { /* paranoia */
5394 cur_var->next = xzalloc(sizeof(*cur_var));
5395 cur_var = cur_var->next;
5396 cur_var->varstr = *e;
5397 cur_var->max_len = strlen(*e);
5398 cur_var->flg_export = 1;
5402 debug_printf_env("putenv '%s'\n", hush_version_str);
5403 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5404 #if ENABLE_FEATURE_EDITING
5405 G.line_input_state = new_line_input_t(FOR_SHELL);
5407 G.global_argc = argc;
5408 G.global_argv = argv;
5409 /* Initialize some more globals to non-zero values */
5411 #if ENABLE_HUSH_INTERACTIVE
5412 if (ENABLE_FEATURE_EDITING)
5413 cmdedit_set_initial_prompt();
5417 /* Shell is non-interactive at first. We need to call
5418 * block_signals(0) if we are going to execute "sh <script>",
5419 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5420 * If we later decide that we are interactive, we run block_signals(0)
5421 * (or re-run block_signals(1) if we ran block_signals(0) before)
5422 * in order to intercept (more) signals.
5426 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5428 opt = getopt(argc, argv, "c:xins"
5438 G.root_pid = getpid();
5439 G.global_argv = argv + optind;
5440 if (!argv[optind]) {
5441 /* -c 'script' (no params): prevent empty $0 */
5442 *--G.global_argv = argv[0];
5444 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5445 G.global_argc = argc - optind;
5446 block_signals(0); /* 0: called 1st time */
5447 parse_and_run_string(optarg);
5450 /* Well, we cannot just declare interactiveness,
5451 * we have to have some stuff (ctty, etc) */
5452 /* G_interactive_fd++; */
5455 /* "-s" means "read from stdin", but this is how we always
5456 * operate, so simply do nothing here. */
5459 case '<': /* "big heredoc" support */
5460 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5463 G.root_pid = bb_strtou(optarg, &optarg, 16);
5465 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5467 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5468 # if ENABLE_HUSH_LOOPS
5470 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5475 set_local_var(xstrdup(optarg), 0, opt == 'R');
5480 if (!set_mode('-', opt))
5484 fprintf(stderr, "Usage: sh [FILE]...\n"
5485 " or: sh -c command [args]...\n\n");
5491 } /* option parsing loop */
5494 G.root_pid = getpid();
5496 /* If we are login shell... */
5497 if (argv[0] && argv[0][0] == '-') {
5499 /* XXX what should argv be while sourcing /etc/profile? */
5500 debug_printf("sourcing /etc/profile\n");
5501 input = fopen_for_read("/etc/profile");
5502 if (input != NULL) {
5503 close_on_exec_on(fileno(input));
5504 block_signals(0); /* 0: called 1st time */
5505 signal_mask_is_inited = 1;
5506 parse_and_run_file(input);
5509 /* bash: after sourcing /etc/profile,
5510 * tries to source (in the given order):
5511 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5512 * stopping of first found. --noprofile turns this off.
5513 * bash also sources ~/.bash_logout on exit.
5514 * If called as sh, skips .bash_XXX files.
5521 * "bash <script>" (which is never interactive (unless -i?))
5522 * sources $BASH_ENV here (without scanning $PATH).
5523 * If called as sh, does the same but with $ENV.
5525 debug_printf("running script '%s'\n", argv[optind]);
5526 G.global_argv = argv + optind;
5527 G.global_argc = argc - optind;
5528 input = xfopen_for_read(argv[optind]);
5529 close_on_exec_on(fileno(input));
5530 if (!signal_mask_is_inited)
5531 block_signals(0); /* 0: called 1st time */
5532 parse_and_run_file(input);
5533 #if ENABLE_FEATURE_CLEAN_UP
5539 /* Up to here, shell was non-interactive. Now it may become one.
5540 * NB: don't forget to (re)run block_signals(0/1) as needed.
5543 /* A shell is interactive if the '-i' flag was given, or if all of
5544 * the following conditions are met:
5546 * no arguments remaining or the -s flag given
5547 * standard input is a terminal
5548 * standard output is a terminal
5549 * Refer to Posix.2, the description of the 'sh' utility.
5552 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5553 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5554 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5555 //TODO: "interactive" and "have job control" are two different things.
5556 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5557 //should stay on! Currently, we mix these into one.
5558 if (G.saved_tty_pgrp >= 0) {
5559 /* try to dup stdin to high fd#, >= 255 */
5560 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5561 if (G_interactive_fd < 0) {
5562 /* try to dup to any fd */
5563 G_interactive_fd = dup(STDIN_FILENO);
5564 if (G_interactive_fd < 0)
5566 G_interactive_fd = 0;
5568 // TODO: track & disallow any attempts of user
5569 // to (inadvertently) close/redirect it
5572 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5573 if (G_interactive_fd) {
5576 /* We are indeed interactive shell, and we will perform
5577 * job control. Setting up for that. */
5579 close_on_exec_on(G_interactive_fd);
5580 /* If we were run as 'hush &', sleep until we are
5581 * in the foreground (tty pgrp == our pgrp).
5582 * If we get started under a job aware app (like bash),
5583 * make sure we are now in charge so we don't fight over
5584 * who gets the foreground */
5586 shell_pgrp = getpgrp();
5587 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5588 if (G.saved_tty_pgrp == shell_pgrp)
5590 /* send TTIN to ourself (should stop us) */
5591 kill(- shell_pgrp, SIGTTIN);
5593 /* Block some signals */
5594 block_signals(signal_mask_is_inited);
5595 /* Set other signals to restore saved_tty_pgrp */
5596 set_fatal_handlers();
5597 /* Put ourselves in our own process group */
5598 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5599 /* Grab control of the terminal */
5600 tcsetpgrp(G_interactive_fd, getpid());
5601 /* -1 is special - makes xfuncs longjmp, not exit
5602 * (we reset die_sleep = 0 whereever we [v]fork) */
5603 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5604 if (setjmp(die_jmp)) {
5605 /* xfunc has failed! die die die */
5606 hush_exit(xfunc_error_retval);
5608 } else if (!signal_mask_is_inited) {
5609 block_signals(0); /* 0: called 1st time */
5610 } /* else: block_signals(0) was done before */
5611 #elif ENABLE_HUSH_INTERACTIVE
5612 /* No job control compiled in, only prompt/line editing */
5613 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5614 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5615 if (G_interactive_fd < 0) {
5616 /* try to dup to any fd */
5617 G_interactive_fd = dup(STDIN_FILENO);
5618 if (G_interactive_fd < 0)
5620 G_interactive_fd = 0;
5623 if (G_interactive_fd) {
5624 close_on_exec_on(G_interactive_fd);
5625 block_signals(signal_mask_is_inited);
5626 } else if (!signal_mask_is_inited) {
5630 /* We have interactiveness code disabled */
5631 if (!signal_mask_is_inited) {
5636 * if interactive but not a login shell, sources ~/.bashrc
5637 * (--norc turns this off, --rcfile <file> overrides)
5640 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5641 printf("\n\n%s hush - the humble shell\n", bb_banner);
5642 printf("Enter 'help' for a list of built-in commands.\n\n");
5645 parse_and_run_file(stdin);
5648 #if ENABLE_FEATURE_CLEAN_UP
5649 if (G.cwd != bb_msg_unknown)
5651 cur_var = G.top_var->next;
5653 struct variable *tmp = cur_var;
5654 if (!cur_var->max_len)
5655 free(cur_var->varstr);
5656 cur_var = cur_var->next;
5660 hush_exit(G.last_exitcode);
5665 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5666 int lash_main(int argc, char **argv)
5668 //bb_error_msg("lash is deprecated, please use hush instead");
5669 return hush_main(argc, argv);
5677 static int builtin_trap(char **argv)
5684 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5688 /* No args: print all trapped. This isn't 100% correct as we
5689 * should be escaping the cmd so that it can be pasted back in
5691 for (i = 0; i < NSIG; ++i)
5693 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5694 return EXIT_SUCCESS;
5699 /* If first arg is decimal: reset all specified signals */
5700 sig = bb_strtou(*argv, NULL, 10);
5706 sig = get_signum(*argv++);
5707 if (sig < 0 || sig >= NSIG) {
5709 /* Mimic bash message exactly */
5710 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5715 G.traps[sig] = xstrdup(new_cmd);
5717 debug_printf("trap: setting SIG%s (%i) to '%s'",
5718 get_signame(sig), sig, G.traps[sig]);
5720 /* There is no signal for 0 (EXIT) */
5725 sigaddset(&G.blocked_set, sig);
5727 /* There was a trap handler, we are removing it
5728 * (if sig has non-DFL handling,
5729 * we don't need to do anything) */
5730 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5732 sigdelset(&G.blocked_set, sig);
5734 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5739 /* First arg is "-": reset all specified to default */
5740 /* First arg is "": ignore all specified */
5741 /* Everything else: execute first arg upon signal */
5743 bb_error_msg("trap: invalid arguments");
5744 return EXIT_FAILURE;
5746 if (NOT_LONE_DASH(*argv))
5752 static int builtin_true(char **argv UNUSED_PARAM)
5757 static int builtin_test(char **argv)
5764 return test_main(argc, argv - argc);
5767 static int builtin_echo(char **argv)
5774 return echo_main(argc, argv - argc);
5777 static int builtin_eval(char **argv)
5779 int rcode = EXIT_SUCCESS;
5782 char *str = expand_strvec_to_string(argv);
5784 * eval "echo Hi; done" ("done" is syntax error):
5785 * "echo Hi" will not execute too.
5787 parse_and_run_string(str);
5789 rcode = G.last_exitcode;
5794 static int builtin_cd(char **argv)
5796 const char *newdir = argv[1];
5797 if (newdir == NULL) {
5798 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5799 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5801 newdir = getenv("HOME") ? : "/";
5803 if (chdir(newdir)) {
5804 /* Mimic bash message exactly */
5805 bb_perror_msg("cd: %s", newdir);
5806 return EXIT_FAILURE;
5809 return EXIT_SUCCESS;
5812 static int builtin_exec(char **argv)
5814 if (*++argv == NULL)
5815 return EXIT_SUCCESS; /* bash does this */
5820 // FIXME: if exec fails, bash does NOT exit! We do...
5821 pseudo_exec_argv(&dummy, argv, 0, NULL);
5826 static int builtin_exit(char **argv)
5828 debug_printf_exec("%s()\n", __func__);
5829 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5830 //puts("exit"); /* bash does it */
5831 // TODO: warn if we have background jobs: "There are stopped jobs"
5832 // On second consecutive 'exit', exit anyway.
5833 if (*++argv == NULL)
5834 hush_exit(G.last_exitcode);
5835 /* mimic bash: exit 123abc == exit 255 + error msg */
5836 xfunc_error_retval = 255;
5837 /* bash: exit -2 == exit 254, no error msg */
5838 hush_exit(xatoi(*argv) & 0xff);
5841 static int builtin_export(char **argv)
5843 if (*++argv == NULL) {
5845 // ash emits: export VAR='VAL'
5846 // bash: declare -x VAR="VAL"
5847 // (both also escape as needed (quotes, $, etc))
5852 return EXIT_SUCCESS;
5859 value = strchr(name, '=');
5861 /* They are exporting something without a =VALUE */
5862 struct variable *var;
5864 var = get_local_var(name);
5866 var->flg_export = 1;
5867 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5868 putenv(var->varstr);
5870 /* bash does not return an error when trying to export
5871 * an undefined variable. Do likewise. */
5874 set_local_var(xstrdup(name), 1, 0);
5877 return EXIT_SUCCESS;
5881 /* built-in 'fg' and 'bg' handler */
5882 static int builtin_fg_bg(char **argv)
5887 if (!G_interactive_fd)
5888 return EXIT_FAILURE;
5889 /* If they gave us no args, assume they want the last backgrounded task */
5891 for (pi = G.job_list; pi; pi = pi->next) {
5892 if (pi->jobid == G.last_jobid) {
5896 bb_error_msg("%s: no current job", argv[0]);
5897 return EXIT_FAILURE;
5899 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5900 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5901 return EXIT_FAILURE;
5903 for (pi = G.job_list; pi; pi = pi->next) {
5904 if (pi->jobid == jobnum) {
5908 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5909 return EXIT_FAILURE;
5911 // TODO: bash prints a string representation
5912 // of job being foregrounded (like "sleep 1 | cat")
5913 if (argv[0][0] == 'f') {
5914 /* Put the job into the foreground. */
5915 tcsetpgrp(G_interactive_fd, pi->pgrp);
5918 /* Restart the processes in the job */
5919 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5920 for (i = 0; i < pi->num_cmds; i++) {
5921 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5922 pi->cmds[i].is_stopped = 0;
5924 pi->stopped_cmds = 0;
5926 i = kill(- pi->pgrp, SIGCONT);
5928 if (errno == ESRCH) {
5929 delete_finished_bg_job(pi);
5930 return EXIT_SUCCESS;
5932 bb_perror_msg("kill (SIGCONT)");
5935 if (argv[0][0] == 'f') {
5937 return checkjobs_and_fg_shell(pi);
5939 return EXIT_SUCCESS;
5943 #if ENABLE_HUSH_HELP
5944 static int builtin_help(char **argv UNUSED_PARAM)
5946 const struct built_in_command *x;
5949 "Built-in commands:\n"
5950 "------------------\n");
5951 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5952 printf("%s\t%s\n", x->cmd, x->descr);
5955 return EXIT_SUCCESS;
5960 static int builtin_jobs(char **argv UNUSED_PARAM)
5963 const char *status_string;
5965 for (job = G.job_list; job; job = job->next) {
5966 if (job->alive_cmds == job->stopped_cmds)
5967 status_string = "Stopped";
5969 status_string = "Running";
5971 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5973 return EXIT_SUCCESS;
5978 static int builtin_memleak(char **argv UNUSED_PARAM)
5983 /* Crude attempt to find where "free memory" starts,
5984 * sans fragmentation. */
5986 l = (unsigned long)p;
5989 if (l < (unsigned long)p) l = (unsigned long)p;
5992 if (!G.memleak_value)
5993 G.memleak_value = l;
5995 l -= G.memleak_value;
6002 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6007 static int builtin_pwd(char **argv UNUSED_PARAM)
6010 return EXIT_SUCCESS;
6013 static int builtin_read(char **argv)
6016 const char *name = argv[1] ? argv[1] : "REPLY";
6017 //TODO: check that argv[1] is a valid variable name
6019 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6020 return set_local_var(string, 0, 0);
6023 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6024 * built-in 'set' handler
6026 * set [-abCefhmnuvx] [-o option] [argument...]
6027 * set [+abCefhmnuvx] [+o option] [argument...]
6028 * set -- [argument...]
6031 * Implementations shall support the options in both their hyphen and
6032 * plus-sign forms. These options can also be specified as options to sh.
6034 * Write out all variables and their values: set
6035 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6036 * Turn on the -x and -v options: set -xv
6037 * Unset all positional parameters: set --
6038 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6039 * Set the positional parameters to the expansion of x, even if x expands
6040 * with a leading '-' or '+': set -- $x
6042 * So far, we only support "set -- [argument...]" and some of the short names.
6044 static int builtin_set(char **argv)
6047 char **pp, **g_argv;
6048 char *arg = *++argv;
6052 for (e = G.top_var; e; e = e->next)
6054 return EXIT_SUCCESS;
6058 if (!strcmp(arg, "--")) {
6063 if (arg[0] == '+' || arg[0] == '-') {
6064 for (n = 1; arg[n]; ++n)
6065 if (set_mode(arg[0], arg[n]))
6071 } while ((arg = *++argv) != NULL);
6072 /* Now argv[0] is 1st argument */
6074 /* Only reset global_argv if we didn't process anything */
6076 return EXIT_SUCCESS;
6079 /* NB: G.global_argv[0] ($0) is never freed/changed */
6080 g_argv = G.global_argv;
6081 if (G.global_args_malloced) {
6087 G.global_args_malloced = 1;
6088 pp = xzalloc(sizeof(pp[0]) * 2);
6089 pp[0] = g_argv[0]; /* retain $0 */
6092 /* This realloc's G.global_argv */
6093 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6100 return EXIT_SUCCESS;
6102 /* Nothing known, so abort */
6104 bb_error_msg("set: %s: invalid option", arg);
6105 return EXIT_FAILURE;
6108 static int builtin_shift(char **argv)
6114 if (n >= 0 && n < G.global_argc) {
6115 if (G.global_args_malloced) {
6118 free(G.global_argv[m++]);
6121 memmove(&G.global_argv[1], &G.global_argv[n+1],
6122 G.global_argc * sizeof(G.global_argv[0]));
6123 return EXIT_SUCCESS;
6125 return EXIT_FAILURE;
6128 static int builtin_source(char **argv)
6132 if (*++argv == NULL)
6133 return EXIT_FAILURE;
6135 /* XXX search through $PATH is missing */
6136 input = fopen_or_warn(*argv, "r");
6138 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6139 return EXIT_FAILURE;
6141 close_on_exec_on(fileno(input));
6143 /* Now run the file */
6145 /* XXX argv and argc are broken; need to save old G.global_argv
6146 * (pointer only is OK!) on this stack frame,
6147 * set G.global_argv=argv+1, recurse, and restore. */
6148 parse_and_run_file(input);
6150 return G.last_exitcode;
6153 static int builtin_umask(char **argv)
6156 const char *arg = argv[1];
6158 //TODO: umask may take chmod-like symbolic masks
6159 new_umask = bb_strtou(arg, NULL, 8);
6161 //Message? bash examples:
6162 //bash: umask: 'q': invalid symbolic mode operator
6163 //bash: umask: 999: octal number out of range
6164 return EXIT_FAILURE;
6167 new_umask = umask(0);
6168 printf("%.3o\n", (unsigned) new_umask);
6169 /* fall through and restore new_umask which we set to 0 */
6172 return EXIT_SUCCESS;
6175 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6176 static int builtin_unset(char **argv)
6182 return EXIT_SUCCESS;
6185 if (argv[0][0] == '-') {
6186 switch (argv[0][1]) {
6192 bb_error_msg("unset: %s: invalid option", *argv);
6193 return EXIT_FAILURE;
6195 //TODO: disallow "unset -vf ..." too
6202 if (unset_local_var(*argv)) {
6203 /* unset <nonexistent_var> doesn't fail.
6204 * Error is when one tries to unset RO var.
6205 * Message was printed by unset_local_var. */
6209 #if ENABLE_HUSH_FUNCTIONS
6211 unset_local_func(*argv);
6219 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6220 static int builtin_wait(char **argv)
6222 int ret = EXIT_SUCCESS;
6225 if (*++argv == NULL) {
6226 /* Don't care about wait results */
6227 /* Note 1: must wait until there are no more children */
6228 /* Note 2: must be interruptible */
6230 * $ sleep 3 & sleep 6 & wait
6235 * $ sleep 3 & sleep 6 & wait
6239 * ^C <-- after ~4 sec from keyboard
6242 sigaddset(&G.blocked_set, SIGCHLD);
6243 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6246 if (errno == ECHILD)
6248 /* Wait for SIGCHLD or any other signal of interest */
6249 /* sigtimedwait with infinite timeout: */
6250 sig = sigwaitinfo(&G.blocked_set, NULL);
6252 sig = check_and_run_traps(sig);
6253 if (sig && sig != SIGCHLD) { /* see note 2 */
6259 sigdelset(&G.blocked_set, SIGCHLD);
6260 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6264 /* This is probably buggy wrt interruptible-ness */
6266 pid_t pid = bb_strtou(*argv, NULL, 10);
6268 /* mimic bash message */
6269 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6270 return EXIT_FAILURE;
6272 if (waitpid(pid, &status, 0) == pid) {
6273 if (WIFSIGNALED(status))
6274 ret = 128 + WTERMSIG(status);
6275 else if (WIFEXITED(status))
6276 ret = WEXITSTATUS(status);
6280 bb_perror_msg("wait %s", *argv);
6289 #if ENABLE_HUSH_LOOPS
6290 static int builtin_break(char **argv)
6292 if (G.depth_of_loop == 0) {
6293 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6294 return EXIT_SUCCESS; /* bash compat */
6296 G.flag_break_continue++; /* BC_BREAK = 1 */
6297 G.depth_break_continue = 1;
6299 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6300 if (errno || !G.depth_break_continue || argv[2]) {
6301 bb_error_msg("%s: bad arguments", argv[0]);
6302 G.flag_break_continue = BC_BREAK;
6303 G.depth_break_continue = UINT_MAX;
6306 if (G.depth_of_loop < G.depth_break_continue)
6307 G.depth_break_continue = G.depth_of_loop;
6308 return EXIT_SUCCESS;
6311 static int builtin_continue(char **argv)
6313 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6314 return builtin_break(argv);