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>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * o_addchr() derived from similar w_addchar function in glibc-2.2.
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen.
26 * Miscellaneous bugfixes from Matt Kraai.
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * POSIX syntax not implemented:
41 * Arithmetic Expansion
42 * <(list) and >(list) Process Substitution
43 * Here Documents ( << word )
46 * Parameter Expansion for substring processing ${var#word} ${var%word}
48 * Bash stuff maybe optional enable:
49 * &> and >& redirection of stdout+stderr
51 * reserved words: [[ ]] function select
52 * substrings ${var:1:5}
55 * job handling woefully incomplete and buggy (improved --vda)
57 * port selected bugfixes from post-0.49 busybox lash - done?
58 * change { and } from special chars to reserved words
59 * builtins: return, trap, ulimit
60 * test magic exec with redirection only
61 * follow IFS rules more precisely, including update semantics
62 * figure out what to do with backslash-newline
63 * propagate syntax errors, die on resource errors?
64 * continuation lines, both explicit and implicit - done?
65 * maybe change charmap[] to use 2-bit entries
67 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
70 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
71 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
72 //#include "applet_tables.h" doesn't work
74 /* #include <dmalloc.h> */
81 #define HUSH_VER_STR "0.92"
83 #if defined SINGLE_APPLET_MAIN
84 /* STANDALONE does not make sense, and won't compile */
85 #undef CONFIG_FEATURE_SH_STANDALONE
86 #undef ENABLE_FEATURE_SH_STANDALONE
87 #undef USE_FEATURE_SH_STANDALONE
88 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
89 #define ENABLE_FEATURE_SH_STANDALONE 0
90 #define USE_FEATURE_SH_STANDALONE(...)
91 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
94 #if !BB_MMU && ENABLE_HUSH_TICK
95 //#undef ENABLE_HUSH_TICK
96 //#define ENABLE_HUSH_TICK 0
97 #warning On NOMMU, hush command substitution is dangerous.
98 #warning Dont use it for commands which produce lots of output.
99 #warning For more info see shell/hush.c, generate_stream_from_list().
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 /* Keep unconditionally on for now */
123 #define ENABLE_HUSH_FUNCTIONS 0
126 /* If you comment out one of these below, it will be #defined later
127 * to perform debug printfs to stderr: */
128 #define debug_printf(...) do {} while (0)
129 /* Finer-grained debug switches */
130 #define debug_printf_parse(...) do {} while (0)
131 #define debug_print_tree(a, b) do {} while (0)
132 #define debug_printf_exec(...) do {} while (0)
133 #define debug_printf_env(...) do {} while (0)
134 #define debug_printf_jobs(...) do {} while (0)
135 #define debug_printf_expand(...) do {} while (0)
136 #define debug_printf_glob(...) do {} while (0)
137 #define debug_printf_list(...) do {} while (0)
138 #define debug_printf_subst(...) do {} while (0)
139 #define debug_printf_clean(...) do {} while (0)
142 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
145 #ifndef debug_printf_parse
146 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
149 #ifndef debug_printf_exec
150 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
153 #ifndef debug_printf_env
154 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
157 #ifndef debug_printf_jobs
158 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
164 #ifndef debug_printf_expand
165 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
166 #define DEBUG_EXPAND 1
168 #define DEBUG_EXPAND 0
171 #ifndef debug_printf_glob
172 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
178 #ifndef debug_printf_list
179 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
182 #ifndef debug_printf_subst
183 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
186 #ifndef debug_printf_clean
187 /* broken, of course, but OK for testing */
188 static const char *indenter(int i)
190 static const char blanks[] ALIGN1 =
192 return &blanks[sizeof(blanks) - i - 1];
194 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
195 #define DEBUG_CLEAN 1
199 static void debug_print_strings(const char *prefix, char **vv)
201 fprintf(stderr, "%s:\n", prefix);
203 fprintf(stderr, " '%s'\n", *vv++);
206 #define debug_print_strings(prefix, vv) ((void)0)
210 * Leak hunting. Use hush_leaktool.sh for post-processing.
212 #ifdef FOR_HUSH_LEAKTOOL
213 /* suppress "warning: no previous prototype..." */
214 void *xxmalloc(int lineno, size_t size);
215 void *xxrealloc(int lineno, void *ptr, size_t size);
216 char *xxstrdup(int lineno, const char *str);
217 void xxfree(void *ptr);
218 void *xxmalloc(int lineno, size_t size)
220 void *ptr = xmalloc((size + 0xff) & ~0xff);
221 fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
224 void *xxrealloc(int lineno, void *ptr, size_t size)
226 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
227 fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
230 char *xxstrdup(int lineno, const char *str)
232 char *ptr = xstrdup(str);
233 fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
236 void xxfree(void *ptr)
238 fprintf(stderr, "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 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
250 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
252 #define SPECIAL_VAR_SYMBOL 3
253 #define PARSEFLAG_EXIT_FROM_LOOP 1
255 typedef enum redir_type {
257 REDIRECT_OVERWRITE = 2,
263 /* The descrip member of this structure is only used to make
264 * debugging output pretty */
265 static const struct {
267 signed char default_fd;
271 { O_RDONLY, 0, "<" },
272 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
273 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
274 { O_RDONLY, -1, "<<" },
278 typedef enum pipe_style {
285 typedef enum reserved_style {
294 #if ENABLE_HUSH_LOOPS
301 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
306 /* two pseudo-keywords support contrived "case" syntax: */
307 RES_MATCH , /* "word)" */
308 RES_CASEI , /* "this command is inside CASE" */
315 struct redir_struct {
316 struct redir_struct *next;
317 char *rd_filename; /* filename */
318 int fd; /* file descriptor being redirected */
319 int dup; /* -1, or file descriptor being duplicated */
320 smallint /*enum redir_type*/ rd_type;
324 pid_t pid; /* 0 if exited */
325 int assignment_cnt; /* how many argv[i] are assignments? */
326 smallint is_stopped; /* is the command currently running? */
327 smallint grp_type; /* GRP_xxx */
328 struct pipe *group; /* if non-NULL, this "prog" is {} group,
329 * subshell, or a compound statement */
330 char **argv; /* command name and arguments */
331 struct redir_struct *redirects; /* I/O redirections */
333 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
334 * and on execution these are substituted with their values.
335 * Substitution can make _several_ words out of one argv[n]!
336 * Example: argv[0]=='.^C*^C.' here: echo .$*.
337 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
340 #define GRP_SUBSHELL 1
341 #if ENABLE_HUSH_FUNCTIONS
342 #define GRP_FUNCTION 2
347 int num_cmds; /* total number of commands in job */
348 int alive_cmds; /* number of commands running (not exited) */
349 int stopped_cmds; /* number of commands alive, but stopped */
351 int jobid; /* job number */
352 pid_t pgrp; /* process group ID for the job */
353 char *cmdtext; /* name of job */
355 struct command *cmds; /* array of commands in pipe */
356 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
357 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
358 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
361 /* This holds pointers to the various results of parsing */
362 struct parse_context {
363 struct command *command;
364 struct pipe *list_head;
366 struct redir_struct *pending_redirect;
369 smallint ctx_inverted; /* "! cmd | cmd" */
371 smallint ctx_dsemicolon; /* ";;" seen */
373 int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
374 struct parse_context *stack;
378 /* On program start, environ points to initial environment.
379 * putenv adds new pointers into it, unsetenv removes them.
380 * Neither of these (de)allocates the strings.
381 * setenv allocates new strings in malloc space and does putenv,
382 * and thus setenv is unusable (leaky) for shell's purposes */
383 #define setenv(...) setenv_is_leaky_dont_use()
385 struct variable *next;
386 char *varstr; /* points to "name=" portion */
387 int max_len; /* if > 0, name is part of initial env; else name is malloced */
388 smallint flg_export; /* putenv should be done on this var */
389 smallint flg_read_only;
392 typedef struct o_string {
394 int length; /* position where data is appended */
396 /* Misnomer! it's not "quoting", it's "protection against globbing"!
397 * (by prepending \ to *, ?, [ and to \ too) */
401 smallint has_empty_slot;
402 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
405 MAYBE_ASSIGNMENT = 0,
406 DEFINITELY_ASSIGNMENT = 1,
408 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
410 /* Used for initialization: o_string foo = NULL_O_STRING; */
411 #define NULL_O_STRING { NULL }
413 /* I can almost use ordinary FILE*. Is open_memstream() universally
414 * available? Where is it documented? */
415 typedef struct in_str {
417 /* eof_flag=1: last char in ->p is really an EOF */
418 char eof_flag; /* meaningless if ->p == NULL */
420 #if ENABLE_HUSH_INTERACTIVE
422 smallint promptmode; /* 0: PS1, 1: PS2 */
425 int (*get) (struct in_str *);
426 int (*peek) (struct in_str *);
428 #define i_getch(input) ((input)->get(input))
429 #define i_peek(input) ((input)->peek(input))
433 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
434 CHAR_IFS = 2, /* treated as ordinary if quoted */
435 CHAR_SPECIAL = 3, /* example: $ */
444 /* "Globals" within this file */
445 /* Sorted roughly by size (smaller offsets == smaller code) */
447 #if ENABLE_HUSH_INTERACTIVE
448 /* 'interactive_fd' is a fd# open to ctty, if we have one
449 * _AND_ if we decided to act interactively */
454 #if ENABLE_FEATURE_EDITING
455 line_input_t *line_input_state;
461 pid_t saved_tty_pgrp;
463 struct pipe *job_list;
464 struct pipe *toplevel_list;
465 //// smallint ctrl_z_flag;
467 smallint flag_SIGINT;
468 #if ENABLE_HUSH_LOOPS
469 smallint flag_break_continue;
472 /* These four support $?, $#, and $1 */
473 smalluint last_return_code;
474 /* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
475 smalluint global_args_malloced;
476 /* how many non-NULL argv's we have. NB: $# + 1 */
479 #if ENABLE_HUSH_LOOPS
480 unsigned depth_break_continue;
481 unsigned depth_of_loop;
485 struct variable *top_var; /* = &G.shell_ver (set in main()) */
486 struct variable shell_ver;
487 #if ENABLE_FEATURE_SH_STANDALONE
488 struct nofork_save_area nofork_save;
491 sigjmp_buf toplevel_jb;
493 unsigned char charmap[256];
494 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
495 /* Signal and trap handling */
496 // unsigned count_SIGCHLD;
497 // unsigned handled_SIGCHLD;
498 /* which signals have non-DFL handler (even with no traps set)? */
499 unsigned non_DFL_mask;
500 char **traps; /* char *traps[NSIG] */
501 sigset_t blocked_set;
502 sigset_t inherited_set;
504 #define G (*ptr_to_globals)
505 /* Not #defining name to G.name - this quickly gets unwieldy
506 * (too many defines). Also, I actually prefer to see when a variable
507 * is global, thus "G." prefix is a useful hint */
508 #define INIT_G() do { \
509 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
513 /* Function prototypes for builtins */
514 static int builtin_cd(char **argv);
515 static int builtin_echo(char **argv);
516 static int builtin_eval(char **argv);
517 static int builtin_exec(char **argv);
518 static int builtin_exit(char **argv);
519 static int builtin_export(char **argv);
521 static int builtin_fg_bg(char **argv);
522 static int builtin_jobs(char **argv);
525 static int builtin_help(char **argv);
527 static int builtin_pwd(char **argv);
528 static int builtin_read(char **argv);
529 static int builtin_test(char **argv);
530 static int builtin_trap(char **argv);
531 static int builtin_true(char **argv);
532 static int builtin_set(char **argv);
533 static int builtin_shift(char **argv);
534 static int builtin_source(char **argv);
535 static int builtin_umask(char **argv);
536 static int builtin_unset(char **argv);
537 static int builtin_wait(char **argv);
538 #if ENABLE_HUSH_LOOPS
539 static int builtin_break(char **argv);
540 static int builtin_continue(char **argv);
542 //static int builtin_not_written(char **argv);
544 /* Table of built-in functions. They can be forked or not, depending on
545 * context: within pipes, they fork. As simple commands, they do not.
546 * When used in non-forking context, they can change global variables
547 * in the parent shell process. If forked, of course they cannot.
548 * For example, 'unset foo | whatever' will parse and run, but foo will
549 * still be set at the end. */
550 struct built_in_command {
552 int (*function)(char **argv);
555 #define BLTIN(cmd, func, help) { cmd, func, help }
557 #define BLTIN(cmd, func, help) { cmd, func }
561 /* For now, echo and test are unconditionally enabled.
562 * Maybe make it configurable? */
563 static const struct built_in_command bltins[] = {
564 BLTIN("." , builtin_source, "Run commands in a file"),
565 BLTIN(":" , builtin_true, "No-op"),
566 BLTIN("[" , builtin_test, "Test condition"),
568 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
570 #if ENABLE_HUSH_LOOPS
571 BLTIN("break" , builtin_break, "Exit from a loop"),
573 BLTIN("cd" , builtin_cd, "Change directory"),
574 #if ENABLE_HUSH_LOOPS
575 BLTIN("continue", builtin_continue, "Start new loop iteration"),
577 BLTIN("echo" , builtin_echo, "Write to stdout"),
578 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
579 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
580 BLTIN("exit" , builtin_exit, "Exit"),
581 BLTIN("export", builtin_export, "Set environment variable"),
583 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
584 BLTIN("jobs" , builtin_jobs, "List active jobs"),
586 BLTIN("pwd" , builtin_pwd, "Print current directory"),
587 BLTIN("read" , builtin_read, "Input environment variable"),
588 // BLTIN("return", builtin_not_written, "Return from a function"),
589 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
590 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
591 BLTIN("test" , builtin_test, "Test condition"),
592 BLTIN("trap" , builtin_trap, "Trap signals"),
593 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
594 BLTIN("umask" , builtin_umask, "Set file creation mask"),
595 BLTIN("unset" , builtin_unset, "Unset environment variable"),
596 BLTIN("wait" , builtin_wait, "Wait for process"),
598 BLTIN("help" , builtin_help, "List shell built-in commands"),
604 static void maybe_die(const char *notice, const char *msg)
606 /* Was using fancy stuff:
607 * (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
608 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
609 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
610 #if ENABLE_HUSH_INTERACTIVE
611 fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
613 fp(msg ? "%s: %s" : notice, notice, msg);
616 #define syntax(msg) maybe_die("syntax error", msg);
618 /* Debug -- trick gcc to expand __LINE__ and convert to string */
619 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
620 #define _syntax(msg, line) __syntax(msg, line)
621 #define syntax(msg) _syntax(msg, __LINE__)
624 static int glob_needed(const char *s)
629 if (*s == '*' || *s == '[' || *s == '?')
636 static int is_assignment(const char *s)
638 if (!s || !(isalpha(*s) || *s == '_'))
641 while (isalnum(*s) || *s == '_')
646 /* Replace each \x with x in place, return ptr past NUL. */
647 static char *unbackslash(char *src)
653 if ((*dst++ = *src++) == '\0')
659 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
680 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
681 v[count1 + count2] = NULL;
684 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
688 static char **add_string_to_strings(char **strings, char *add)
693 return add_strings_to_strings(strings, v, /*dup:*/ 0);
696 static void putenv_all(char **strings)
701 debug_printf_env("putenv '%s'\n", *strings);
706 static char **putenv_all_and_save_old(char **strings)
716 eq = strchr(*strings, '=');
719 v = getenv(*strings);
722 /* v points to VAL in VAR=VAL, go back to VAR */
723 v -= (eq - *strings) + 1;
724 old = add_string_to_strings(old, v);
733 static void free_strings_and_unsetenv(char **strings, int unset)
743 debug_printf_env("unsetenv '%s'\n", *v);
751 static void free_strings(char **strings)
753 free_strings_and_unsetenv(strings, 0);
757 /* Basic theory of signal handling in shell
758 * ========================================
759 * This does not describe what hush does, rather, it is current understanding
760 * what it _should_ do. If it doesn't, it's a bug.
761 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
763 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
764 * is finished or backgrounded. It is the same in interactive and
765 * non-interactive shells, and is the same regardless of whether
766 * a user trap handler is installed or a shell special one is in effect.
767 * ^C or ^Z from keyboard seem to execute "at once" because it usually
768 * backgrounds (i.e. stops) or kills all members of currently running
771 * Wait builtin in interruptible by signals for which user trap is set
772 * or by SIGINT in interactive shell.
774 * Trap handlers will execute even within trap handlers. (right?)
776 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
778 * If job control is off, backgrounded commands ("cmd &")
779 * have SIGINT, SIGQUIT set to SIG_IGN.
781 * Commands run in command substitution ("`cmd`")
782 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
784 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
785 * by the shell from its parent.
787 * Siganls which differ from SIG_DFL action
788 * (note: child (i.e., [v]forked) shell is not an interactive shell):
791 * SIGTERM (interactive): ignore
792 * SIGHUP (interactive):
793 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
794 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
795 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
796 * that all pipe members are stopped) (right?)
797 * SIGINT (interactive): wait for last pipe, ignore the rest
798 * of the command line, show prompt. NB: ^C does not send SIGINT
799 * to interactive shell while shell is waiting for a pipe,
800 * since shell is bg'ed (is not in foreground process group).
801 * (check/expand this)
802 * Example 1: this waits 5 sec, but does not execute ls:
803 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
804 * Example 2: this does not wait and does not execute ls:
805 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
806 * Example 3: this does not wait 5 sec, but executes ls:
807 * "sleep 5; ls -l" + press ^C
809 * (What happens to signals which are IGN on shell start?)
810 * (What happens with signal mask on shell start?)
812 * Implementation in hush
813 * ======================
814 * We use in-kernel pending signal mask to determine which signals were sent.
815 * We block all signals which we don't want to take action immediately,
816 * i.e. we block all signals which need to have special handling as described
817 * above, and all signals which have traps set.
818 * After each pipe execution, we extract any pending signals via sigtimedwait()
821 * unsigned non_DFL_mask: a mask of such "special" signals
822 * sigset_t blocked_set: current blocked signal set
825 * clear bit in blocked_set unless it is also in non_DFL
826 * "trap 'cmd' SIGxxx":
827 * set bit in blocked_set (even if 'cmd' is '')
828 * after [v]fork, if we plan to be a shell:
829 * nothing for {} child shell (say, "true | { true; true; } | true")
830 * unset all traps if () shell. [TODO]
831 * after [v]fork, if we plan to exec:
832 * POSIX says pending signal mask is cleared in child - no need to clear it.
833 * Restore blocked signal set to one inherited by shell just prior to exec.
835 * Note: as a result, we do not use signal handlers much. The only uses
836 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
837 * and to restore tty pgrp on signal-induced exit.
839 * TODO: check/fix wait builtin to be interruptible.
842 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
844 // G.count_SIGCHLD++;
847 /* called once at shell init */
848 static void init_signal_mask(void)
851 unsigned mask = (1 << SIGQUIT);
852 #if ENABLE_HUSH_INTERACTIVE
853 if (G.interactive_fd) {
859 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
865 G.non_DFL_mask = mask;
867 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
871 sigaddset(&G.blocked_set, sig);
875 sigdelset(&G.blocked_set, SIGCHLD);
876 sigprocmask(SIG_SETMASK, &G.blocked_set, &G.inherited_set);
879 static int check_and_run_traps(int sig)
881 static const struct timespec zero_timespec = { 0, 0 };
882 smalluint save_rcode;
888 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
893 if (G.traps && G.traps[sig]) {
894 if (G.traps[sig][0]) {
895 /* We have user-defined handler */
896 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
897 save_rcode = G.last_return_code;
900 G.last_return_code = save_rcode;
901 } /* else: "" trap, ignoring signal */
904 /* not a trap: special action */
907 // G.count_SIGCHLD++;
916 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
925 /* Restores tty foreground process group, and exits.
926 * May be called as signal handler for fatal signal
927 * (will faithfully resend signal to itself, producing correct exit state)
928 * or called directly with -EXITCODE.
929 * We also call it if xfunc is exiting. */
930 static void sigexit(int sig) NORETURN;
931 static void sigexit(int sig)
933 /* Disable all signals: job control, SIGPIPE, etc. */
934 sigprocmask_allsigs(SIG_BLOCK);
936 #if ENABLE_HUSH_INTERACTIVE
937 /* Careful: we can end up here after [v]fork. Do not restore
938 * tty pgrp then, only top-level shell process does that */
939 if (G.interactive_fd && getpid() == G.root_pid)
940 tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
943 /* Not a signal, just exit */
947 kill_myself_with_sig(sig); /* does not return */
951 static void maybe_set_sighandler(int sig)
953 void (*handler)(int);
954 /* non_DFL_mask'ed signals are, well, masked,
955 * no need to set handler for them.
957 if (!((G.non_DFL_mask >> sig) & 1)) {
958 handler = signal(sig, sigexit);
959 if (handler == SIG_IGN) /* oops... restore back to IGN! */
960 signal(sig, handler);
963 /* Used only to set handler to restore pgrp on exit */
964 static void set_fatal_signals_to_sigexit(void)
967 maybe_set_sighandler(SIGILL );
968 maybe_set_sighandler(SIGFPE );
969 maybe_set_sighandler(SIGBUS );
970 maybe_set_sighandler(SIGSEGV);
971 maybe_set_sighandler(SIGTRAP);
972 } /* else: hush is perfect. what SEGV? */
974 maybe_set_sighandler(SIGABRT);
976 /* bash 3.2 seems to handle these just like 'fatal' ones */
977 maybe_set_sighandler(SIGPIPE);
978 maybe_set_sighandler(SIGALRM);
979 maybe_set_sighandler(SIGHUP );
981 /* if we aren't interactive... but in this case
982 * we never want to restore pgrp on exit, and this fn is not called */
983 /*maybe_set_sighandler(SIGTERM);*/
984 /*maybe_set_sighandler(SIGINT );*/
986 /* Used only to suppress ^Z in `cmd` */
987 static void set_jobctrl_signals_to_IGN(void)
998 #define set_fatal_signals_to_sigexit(handler) ((void)0)
999 #define set_jobctrl_signals_to_IGN(handler) ((void)0)
1003 /* Restores tty foreground process group, and exits. */
1004 static void hush_exit(int exitcode) NORETURN;
1005 static void hush_exit(int exitcode)
1007 if (G.traps && G.traps[0] && G.traps[0][0]) {
1008 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
1014 fflush(NULL); /* flush all streams */
1015 sigexit(- (exitcode & 0xff));
1022 static const char *set_cwd(void)
1024 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1025 * we must not try to free(bb_msg_unknown) */
1026 if (G.cwd == bb_msg_unknown)
1028 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1030 G.cwd = bb_msg_unknown;
1035 /* Get/check local shell variables */
1036 static struct variable *get_local_var(const char *name)
1038 struct variable *cur;
1044 for (cur = G.top_var; cur; cur = cur->next) {
1045 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1051 /* Basically useful version until someone wants to get fancier,
1052 * see the bash man page under "Parameter Expansion" */
1053 static const char *lookup_param(const char *src)
1055 struct variable *var = get_local_var(src);
1057 return strchr(var->varstr, '=') + 1;
1061 /* str holds "NAME=VAL" and is expected to be malloced.
1062 * We take ownership of it.
1063 * flg_export is used by:
1066 * -1: if NAME is set, leave export status alone
1067 * if NAME is not set, do not export
1069 static int set_local_var(char *str, int flg_export)
1071 struct variable *cur;
1075 value = strchr(str, '=');
1076 if (!value) { /* not expected to ever happen? */
1081 name_len = value - str + 1; /* including '=' */
1082 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1084 if (strncmp(cur->varstr, str, name_len) != 0) {
1086 /* Bail out. Note that now cur points
1087 * to last var in linked list */
1093 /* We found an existing var with this name */
1095 if (cur->flg_read_only) {
1096 bb_error_msg("%s: readonly variable", str);
1100 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1101 unsetenv(str); /* just in case */
1103 if (strcmp(cur->varstr, str) == 0) {
1108 if (cur->max_len >= strlen(str)) {
1109 /* This one is from startup env, reuse space */
1110 strcpy(cur->varstr, str);
1113 /* max_len == 0 signifies "malloced" var, which we can
1114 * (and has to) free */
1118 goto set_str_and_exp;
1121 /* Not found - create next variable struct */
1122 cur->next = xzalloc(sizeof(*cur));
1128 if (flg_export == 1)
1129 cur->flg_export = 1;
1130 if (cur->flg_export) {
1131 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1132 return putenv(cur->varstr);
1137 static int unset_local_var(const char *name)
1139 struct variable *cur;
1140 struct variable *prev = prev; /* for gcc */
1144 return EXIT_SUCCESS;
1145 name_len = strlen(name);
1148 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1149 if (cur->flg_read_only) {
1150 bb_error_msg("%s: readonly variable", name);
1151 return EXIT_FAILURE;
1153 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1154 * is ro, and we cannot reach this code on the 1st pass */
1155 prev->next = cur->next;
1156 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1157 bb_unsetenv(cur->varstr);
1161 return EXIT_SUCCESS;
1166 return EXIT_SUCCESS;
1169 #if ENABLE_SH_MATH_SUPPORT
1170 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1171 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1172 static char *endofname(const char *name)
1180 if (!is_in_name(*p))
1186 static void arith_set_local_var(const char *name, const char *val, int flags)
1188 /* arith code doesnt malloc space, so do it for it */
1189 char *var = xasprintf("%s=%s", name, val);
1190 set_local_var(var, flags);
1198 static int static_get(struct in_str *i)
1201 if (ch == '\0') return EOF;
1205 static int static_peek(struct in_str *i)
1210 #if ENABLE_HUSH_INTERACTIVE
1212 static void cmdedit_set_initial_prompt(void)
1214 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1215 G.PS1 = getenv("PS1");
1222 static const char* setup_prompt_string(int promptmode)
1224 const char *prompt_str;
1225 debug_printf("setup_prompt_string %d ", promptmode);
1226 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1227 /* Set up the prompt */
1228 if (promptmode == 0) { /* PS1 */
1230 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1235 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1236 debug_printf("result '%s'\n", prompt_str);
1240 static void get_user_input(struct in_str *i)
1243 const char *prompt_str;
1245 prompt_str = setup_prompt_string(i->promptmode);
1246 #if ENABLE_FEATURE_EDITING
1247 /* Enable command line editing only while a command line
1248 * is actually being read */
1251 /* buglet: SIGINT will not make new prompt to appear _at once_,
1252 * only after <Enter>. (^C will work) */
1253 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1254 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1255 check_and_run_traps(0);
1256 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1257 i->eof_flag = (r < 0);
1258 if (i->eof_flag) { /* EOF/error detected */
1259 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1260 G.user_input_buf[1] = '\0';
1265 fputs(prompt_str, stdout);
1267 G.user_input_buf[0] = r = fgetc(i->file);
1268 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1269 //do we need check_and_run_traps(0)? (maybe only if stdin)
1270 } while (G.flag_SIGINT);
1271 i->eof_flag = (r == EOF);
1273 i->p = G.user_input_buf;
1276 #endif /* INTERACTIVE */
1278 /* This is the magic location that prints prompts
1279 * and gets data back from the user */
1280 static int file_get(struct in_str *i)
1284 /* If there is data waiting, eat it up */
1285 if (i->p && *i->p) {
1286 #if ENABLE_HUSH_INTERACTIVE
1290 if (i->eof_flag && !*i->p)
1293 /* need to double check i->file because we might be doing something
1294 * more complicated by now, like sourcing or substituting. */
1295 #if ENABLE_HUSH_INTERACTIVE
1296 if (G.interactive_fd && i->promptme && i->file == stdin) {
1299 } while (!*i->p); /* need non-empty line */
1300 i->promptmode = 1; /* PS2 */
1305 ch = fgetc(i->file);
1307 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1308 #if ENABLE_HUSH_INTERACTIVE
1315 /* All the callers guarantee this routine will never be
1316 * used right after a newline, so prompting is not needed.
1318 static int file_peek(struct in_str *i)
1321 if (i->p && *i->p) {
1322 if (i->eof_flag && !i->p[1])
1326 ch = fgetc(i->file);
1327 i->eof_flag = (ch == EOF);
1328 i->peek_buf[0] = ch;
1329 i->peek_buf[1] = '\0';
1331 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1335 static void setup_file_in_str(struct in_str *i, FILE *f)
1337 i->peek = file_peek;
1339 #if ENABLE_HUSH_INTERACTIVE
1341 i->promptmode = 0; /* PS1 */
1347 static void setup_string_in_str(struct in_str *i, const char *s)
1349 i->peek = static_peek;
1350 i->get = static_get;
1351 #if ENABLE_HUSH_INTERACTIVE
1353 i->promptmode = 0; /* PS1 */
1363 #define B_CHUNK (32 * sizeof(char*))
1365 static void o_reset(o_string *o)
1373 static void o_free(o_string *o)
1376 memset(o, 0, sizeof(*o));
1379 static void o_grow_by(o_string *o, int len)
1381 if (o->length + len > o->maxlen) {
1382 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1383 o->data = xrealloc(o->data, 1 + o->maxlen);
1387 static void o_addchr(o_string *o, int ch)
1389 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1391 o->data[o->length] = ch;
1393 o->data[o->length] = '\0';
1396 static void o_addstr(o_string *o, const char *str, int len)
1399 memcpy(&o->data[o->length], str, len);
1401 o->data[o->length] = '\0';
1404 static void o_addstrauto(o_string *o, const char *str)
1406 o_addstr(o, str, strlen(str) + 1);
1409 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
1414 && (*str != '*' && *str != '?' && *str != '[')
1422 /* My analysis of quoting semantics tells me that state information
1423 * is associated with a destination, not a source.
1425 static void o_addqchr(o_string *o, int ch)
1428 char *found = strchr("*?[\\", ch);
1433 o->data[o->length] = '\\';
1436 o->data[o->length] = ch;
1438 o->data[o->length] = '\0';
1441 static void o_addQchr(o_string *o, int ch)
1444 if (o->o_quote && strchr("*?[\\", ch)) {
1446 o->data[o->length] = '\\';
1450 o->data[o->length] = ch;
1452 o->data[o->length] = '\0';
1455 static void o_addQstr(o_string *o, const char *str, int len)
1458 o_addstr(o, str, len);
1464 int ordinary_cnt = strcspn(str, "*?[\\");
1465 if (ordinary_cnt > len) /* paranoia */
1467 o_addstr(o, str, ordinary_cnt);
1468 if (ordinary_cnt == len)
1470 str += ordinary_cnt;
1471 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1475 if (ch) { /* it is necessarily one of "*?[\\" */
1477 o->data[o->length] = '\\';
1481 o->data[o->length] = ch;
1483 o->data[o->length] = '\0';
1487 /* A special kind of o_string for $VAR and `cmd` expansion.
1488 * It contains char* list[] at the beginning, which is grown in 16 element
1489 * increments. Actual string data starts at the next multiple of 16 * (char*).
1490 * list[i] contains an INDEX (int!) into this string data.
1491 * It means that if list[] needs to grow, data needs to be moved higher up
1492 * but list[i]'s need not be modified.
1493 * NB: remembering how many list[i]'s you have there is crucial.
1494 * o_finalize_list() operation post-processes this structure - calculates
1495 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1497 #if DEBUG_EXPAND || DEBUG_GLOB
1498 static void debug_print_list(const char *prefix, o_string *o, int n)
1500 char **list = (char**)o->data;
1501 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1503 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1504 prefix, list, n, string_start, o->length, o->maxlen);
1506 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1507 o->data + (int)list[i] + string_start,
1508 o->data + (int)list[i] + string_start);
1512 const char *p = o->data + (int)list[n - 1] + string_start;
1513 fprintf(stderr, " total_sz:%ld\n", (p + strlen(p) + 1) - o->data);
1517 #define debug_print_list(prefix, o, n) ((void)0)
1520 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1521 * in list[n] so that it points past last stored byte so far.
1522 * It returns n+1. */
1523 static int o_save_ptr_helper(o_string *o, int n)
1525 char **list = (char**)o->data;
1529 if (!o->has_empty_slot) {
1530 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1531 string_len = o->length - string_start;
1532 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1533 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1534 /* list[n] points to string_start, make space for 16 more pointers */
1535 o->maxlen += 0x10 * sizeof(list[0]);
1536 o->data = xrealloc(o->data, o->maxlen + 1);
1537 list = (char**)o->data;
1538 memmove(list + n + 0x10, list + n, string_len);
1539 o->length += 0x10 * sizeof(list[0]);
1541 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1543 /* We have empty slot at list[n], reuse without growth */
1544 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1545 string_len = o->length - string_start;
1546 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1547 o->has_empty_slot = 0;
1549 list[n] = (char*)(ptrdiff_t)string_len;
1553 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1554 static int o_get_last_ptr(o_string *o, int n)
1556 char **list = (char**)o->data;
1557 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1559 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1562 /* o_glob performs globbing on last list[], saving each result
1563 * as a new list[]. */
1564 static int o_glob(o_string *o, int n)
1570 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1572 return o_save_ptr_helper(o, n);
1573 pattern = o->data + o_get_last_ptr(o, n);
1574 debug_printf_glob("glob pattern '%s'\n", pattern);
1575 if (!glob_needed(pattern)) {
1577 o->length = unbackslash(pattern) - o->data;
1578 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1579 return o_save_ptr_helper(o, n);
1582 memset(&globdata, 0, sizeof(globdata));
1583 gr = glob(pattern, 0, NULL, &globdata);
1584 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1585 if (gr == GLOB_NOSPACE)
1586 bb_error_msg_and_die("out of memory during glob");
1587 if (gr == GLOB_NOMATCH) {
1588 globfree(&globdata);
1591 if (gr != 0) { /* GLOB_ABORTED ? */
1592 //TODO: testcase for bad glob pattern behavior
1593 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1595 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1596 char **argv = globdata.gl_pathv;
1597 o->length = pattern - o->data; /* "forget" pattern */
1599 o_addstrauto(o, *argv);
1600 n = o_save_ptr_helper(o, n);
1606 globfree(&globdata);
1608 debug_print_list("o_glob returning", o, n);
1612 /* If o->o_glob == 1, glob the string so far remembered.
1613 * Otherwise, just finish current list[] and start new */
1614 static int o_save_ptr(o_string *o, int n)
1616 if (o->o_glob) { /* if globbing is requested */
1617 /* If o->has_empty_slot, list[n] was already globbed
1618 * (if it was requested back then when it was filled)
1619 * so don't do that again! */
1620 if (!o->has_empty_slot)
1621 return o_glob(o, n); /* o_save_ptr_helper is inside */
1623 return o_save_ptr_helper(o, n);
1626 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1627 static char **o_finalize_list(o_string *o, int n)
1632 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1634 debug_print_list("finalized", o, n);
1635 debug_printf_expand("finalized n:%d\n", n);
1636 list = (char**)o->data;
1637 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1641 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1647 /* expand_strvec_to_strvec() takes a list of strings, expands
1648 * all variable references within and returns a pointer to
1649 * a list of expanded strings, possibly with larger number
1650 * of strings. (Think VAR="a b"; echo $VAR).
1651 * This new list is allocated as a single malloc block.
1652 * NULL-terminated list of char* pointers is at the beginning of it,
1653 * followed by strings themself.
1654 * Caller can deallocate entire list by single free(list). */
1656 /* Store given string, finalizing the word and starting new one whenever
1657 * we encounter IFS char(s). This is used for expanding variable values.
1658 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1659 static int expand_on_ifs(o_string *output, int n, const char *str)
1662 int word_len = strcspn(str, G.ifs);
1664 if (output->o_quote || !output->o_glob)
1665 o_addQstr(output, str, word_len);
1666 else /* protect backslashes against globbing up :) */
1667 o_addstr_duplicate_backslash(output, str, word_len);
1670 if (!*str) /* EOL - do not finalize word */
1672 o_addchr(output, '\0');
1673 debug_print_list("expand_on_ifs", output, n);
1674 n = o_save_ptr(output, n);
1675 str += strspn(str, G.ifs); /* skip ifs chars */
1677 debug_print_list("expand_on_ifs[1]", output, n);
1681 #if ENABLE_HUSH_TICK
1682 static int process_command_subs(o_string *dest,
1683 struct in_str *input, const char *subst_end);
1686 /* Expand all variable references in given string, adding words to list[]
1687 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1688 * to be filled). This routine is extremely tricky: has to deal with
1689 * variables/parameters with whitespace, $* and $@, and constructs like
1690 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1691 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1693 /* or_mask is either 0 (normal case) or 0x80
1694 * (expansion of right-hand side of assignment == 1-element expand.
1695 * It will also do no globbing, and thus we must not backslash-quote!) */
1697 char first_ch, ored_ch;
1704 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1705 debug_print_list("expand_vars_to_list", output, n);
1706 n = o_save_ptr(output, n);
1707 debug_print_list("expand_vars_to_list[0]", output, n);
1709 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1710 #if ENABLE_HUSH_TICK
1711 o_string subst_result = NULL_O_STRING;
1713 o_addstr(output, arg, p - arg);
1714 debug_print_list("expand_vars_to_list[1]", output, n);
1716 p = strchr(p, SPECIAL_VAR_SYMBOL);
1718 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1719 /* "$@" is special. Even if quoted, it can still
1720 * expand to nothing (not even an empty string) */
1721 if ((first_ch & 0x7f) != '@')
1722 ored_ch |= first_ch;
1724 switch (first_ch & 0x7f) {
1725 /* Highest bit in first_ch indicates that var is double-quoted */
1727 val = utoa(G.root_pid);
1729 case '!': /* bg pid */
1730 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1732 case '?': /* exitcode */
1733 val = utoa(G.last_return_code);
1735 case '#': /* argc */
1736 if (arg[1] != SPECIAL_VAR_SYMBOL)
1737 /* actually, it's a ${#var} */
1739 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1744 if (!G.global_argv[i])
1746 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1747 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1748 smallint sv = output->o_quote;
1749 /* unquoted var's contents should be globbed, so don't quote */
1750 output->o_quote = 0;
1751 while (G.global_argv[i]) {
1752 n = expand_on_ifs(output, n, G.global_argv[i]);
1753 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1754 if (G.global_argv[i++][0] && G.global_argv[i]) {
1755 /* this argv[] is not empty and not last:
1756 * put terminating NUL, start new word */
1757 o_addchr(output, '\0');
1758 debug_print_list("expand_vars_to_list[2]", output, n);
1759 n = o_save_ptr(output, n);
1760 debug_print_list("expand_vars_to_list[3]", output, n);
1763 output->o_quote = sv;
1765 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1766 * and in this case should treat it like '$*' - see 'else...' below */
1767 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1769 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1770 if (++i >= G.global_argc)
1772 o_addchr(output, '\0');
1773 debug_print_list("expand_vars_to_list[4]", output, n);
1774 n = o_save_ptr(output, n);
1776 } else { /* quoted $*: add as one word */
1778 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1779 if (!G.global_argv[++i])
1782 o_addchr(output, G.ifs[0]);
1786 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1787 /* "Empty variable", used to make "" etc to not disappear */
1791 #if ENABLE_HUSH_TICK
1792 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1793 struct in_str input;
1796 //TODO: can we just stuff it into "output" directly?
1797 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1798 setup_string_in_str(&input, arg);
1799 process_command_subs(&subst_result, &input, NULL);
1800 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1801 val = subst_result.data;
1805 #if ENABLE_SH_MATH_SUPPORT
1806 case '+': { /* <SPECIAL_VAR_SYMBOL>(cmd<SPECIAL_VAR_SYMBOL> */
1807 arith_eval_hooks_t hooks;
1814 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1815 hooks.lookupvar = lookup_param;
1816 hooks.setvar = arith_set_local_var;
1817 hooks.endofname = endofname;
1818 res = arith(arg, &errcode, &hooks);
1821 case -3: maybe_die("arith", "exponent less than 0"); break;
1822 case -2: maybe_die("arith", "divide by zero"); break;
1823 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1824 default: maybe_die("arith", "syntax error"); break;
1827 sprintf(buf, arith_t_fmt, res);
1828 o_addstrauto(output, buf);
1829 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1833 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1835 bool exp_len = false, exp_null = false;
1836 char *var = arg, exp_save, exp_op, *exp_word;
1839 arg[0] = first_ch & 0x7f;
1841 /* prepare for expansions */
1842 if (var[0] == '#') {
1843 /* handle length expansion ${#var} */
1847 /* maybe handle parameter expansion */
1848 exp_off = strcspn(var, ":-=+?");
1852 exp_save = var[exp_off];
1853 exp_null = exp_save == ':';
1854 exp_word = var + exp_off;
1855 if (exp_null) ++exp_word;
1856 exp_op = *exp_word++;
1857 var[exp_off] = '\0';
1861 /* lookup the variable in question */
1862 if (isdigit(var[0])) {
1863 /* handle_dollar() should have vetted var for us */
1865 if (i < G.global_argc)
1866 val = G.global_argv[i];
1867 /* else val remains NULL: $N with too big N */
1869 val = lookup_param(var);
1871 /* handle any expansions */
1873 debug_printf_expand("expand: length of '%s' = ", val);
1874 val = utoa(val ? strlen(val) : 0);
1875 debug_printf_expand("%s\n", val);
1876 } else if (exp_off) {
1877 /* we need to do an expansion */
1878 int exp_test = (!val || (exp_null && !val[0]));
1880 exp_test = !exp_test;
1881 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1882 exp_null ? "true" : "false", exp_test);
1885 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1889 if (exp_op == '=') {
1890 if (isdigit(var[0]) || var[0] == '#') {
1891 maybe_die(var, "special vars cannot assign in this way");
1894 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1895 sprintf(new_var, "%s=%s", var, val);
1896 set_local_var(new_var, -1);
1900 var[exp_off] = exp_save;
1905 #if ENABLE_HUSH_TICK
1908 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1909 debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
1911 /* unquoted var's contents should be globbed, so don't quote */
1912 smallint sv = output->o_quote;
1913 output->o_quote = 0;
1914 n = expand_on_ifs(output, n, val);
1916 output->o_quote = sv;
1918 } else { /* quoted $VAR, val will be appended below */
1919 debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
1924 o_addQstr(output, val, strlen(val));
1926 /* Do the check to avoid writing to a const string */
1927 if (p && *p != SPECIAL_VAR_SYMBOL)
1928 *p = SPECIAL_VAR_SYMBOL;
1930 #if ENABLE_HUSH_TICK
1931 o_free(&subst_result);
1934 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1937 debug_print_list("expand_vars_to_list[a]", output, n);
1938 /* this part is literal, and it was already pre-quoted
1939 * if needed (much earlier), do not use o_addQstr here! */
1940 o_addstrauto(output, arg);
1941 debug_print_list("expand_vars_to_list[b]", output, n);
1942 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1943 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1946 /* allow to reuse list[n] later without re-growth */
1947 output->has_empty_slot = 1;
1949 o_addchr(output, '\0');
1954 static char **expand_variables(char **argv, int or_mask)
1959 o_string output = NULL_O_STRING;
1961 if (or_mask & 0x100) {
1962 output.o_quote = 1; /* protect against globbing for "$var" */
1963 /* (unquoted $var will temporarily switch it off) */
1970 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1973 debug_print_list("expand_variables", &output, n);
1975 /* output.data (malloced in one block) gets returned in "list" */
1976 list = o_finalize_list(&output, n);
1977 debug_print_strings("expand_variables[1]", list);
1981 static char **expand_strvec_to_strvec(char **argv)
1983 return expand_variables(argv, 0x100);
1986 /* Used for expansion of right hand of assignments */
1987 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
1989 static char *expand_string_to_string(const char *str)
1991 char *argv[2], **list;
1993 argv[0] = (char*)str;
1995 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
1997 if (!list[0] || list[1])
1998 bb_error_msg_and_die("BUG in varexp2");
1999 /* actually, just move string 2*sizeof(char*) bytes back */
2000 overlapping_strcpy((char*)list, list[0]);
2001 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2005 /* Used for "eval" builtin */
2006 static char* expand_strvec_to_string(char **argv)
2010 list = expand_variables(argv, 0x80);
2011 /* Convert all NULs to spaces */
2016 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2017 bb_error_msg_and_die("BUG in varexp3");
2018 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2022 overlapping_strcpy((char*)list, list[0]);
2023 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2027 static char **expand_assignments(char **argv, int count)
2031 /* Expand assignments into one string each */
2032 for (i = 0; i < count; i++) {
2033 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2039 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2040 * and stderr if they are redirected. */
2041 static int setup_redirects(struct command *prog, int squirrel[])
2044 struct redir_struct *redir;
2046 for (redir = prog->redirects; redir; redir = redir->next) {
2047 if (redir->dup == -1 && redir->rd_filename == NULL) {
2048 /* something went wrong in the parse. Pretend it didn't happen */
2051 if (redir->dup == -1) {
2053 mode = redir_table[redir->rd_type].mode;
2054 //TODO: check redir for names like '\\'
2055 p = expand_string_to_string(redir->rd_filename);
2056 openfd = open_or_warn(p, mode);
2059 /* this could get lost if stderr has been redirected, but
2060 bash and ash both lose it as well (though zsh doesn't!) */
2064 openfd = redir->dup;
2067 if (openfd != redir->fd) {
2068 if (squirrel && redir->fd < 3) {
2069 squirrel[redir->fd] = dup(redir->fd);
2072 //close(openfd); // close(-3) ??!
2074 dup2(openfd, redir->fd);
2075 if (redir->dup == -1)
2083 static void restore_redirects(int squirrel[])
2086 for (i = 0; i < 3; i++) {
2089 /* We simply die on error */
2096 #if !defined(DEBUG_CLEAN)
2097 #define free_pipe_list(head, indent) free_pipe_list(head)
2098 #define free_pipe(pi, indent) free_pipe(pi)
2100 static int free_pipe_list(struct pipe *head, int indent);
2102 /* return code is the exit status of the pipe */
2103 static int free_pipe(struct pipe *pi, int indent)
2106 struct command *command;
2107 struct redir_struct *r, *rnext;
2108 int a, i, ret_code = 0;
2110 if (pi->stopped_cmds > 0)
2112 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2113 for (i = 0; i < pi->num_cmds; i++) {
2114 command = &pi->cmds[i];
2115 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2116 if (command->argv) {
2117 for (a = 0, p = command->argv; *p; a++, p++) {
2118 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2120 free_strings(command->argv);
2121 command->argv = NULL;
2122 } else if (command->group) {
2123 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2124 ret_code = free_pipe_list(command->group, indent+3);
2125 debug_printf_clean("%s end group\n", indenter(indent));
2127 debug_printf_clean("%s (nil)\n", indenter(indent));
2129 for (r = command->redirects; r; r = rnext) {
2130 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2132 /* guard against the case >$FOO, where foo is unset or blank */
2133 if (r->rd_filename) {
2134 debug_printf_clean(" %s\n", r->rd_filename);
2135 free(r->rd_filename);
2136 r->rd_filename = NULL;
2139 debug_printf_clean("&%d\n", r->dup);
2144 command->redirects = NULL;
2146 free(pi->cmds); /* children are an array, they get freed all at once */
2155 static int free_pipe_list(struct pipe *head, int indent)
2157 int rcode = 0; /* if list has no members */
2158 struct pipe *pi, *next;
2160 for (pi = head; pi; pi = next) {
2162 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2164 rcode = free_pipe(pi, indent);
2165 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2167 /*pi->next = NULL;*/
2175 typedef struct nommu_save_t {
2181 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2182 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2183 #define pseudo_exec(nommu_save, command, argv_expanded) \
2184 pseudo_exec(command, argv_expanded)
2187 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2189 * XXX no exit() here. If you don't exec, use _exit instead.
2190 * The at_exit handlers apparently confuse the calling process,
2191 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2192 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
2193 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
2197 const struct built_in_command *x;
2199 /* If a variable is assigned in a forest, and nobody listens,
2200 * was it ever really set?
2202 if (!argv[assignment_cnt])
2203 _exit(EXIT_SUCCESS);
2205 new_env = expand_assignments(argv, assignment_cnt);
2207 putenv_all(new_env);
2208 free(new_env); /* optional */
2210 nommu_save->new_env = new_env;
2211 nommu_save->old_env = putenv_all_and_save_old(new_env);
2213 if (argv_expanded) {
2214 argv = argv_expanded;
2216 argv = expand_strvec_to_strvec(argv);
2218 nommu_save->argv = argv;
2223 * Check if the command matches any of the builtins.
2224 * Depending on context, this might be redundant. But it's
2225 * easier to waste a few CPU cycles than it is to figure out
2226 * if this is one of those cases.
2228 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2229 if (strcmp(argv[0], x->cmd) == 0) {
2230 debug_printf_exec("running builtin '%s'\n", argv[0]);
2231 rcode = x->function(argv);
2237 /* Check if the command matches any busybox applets */
2238 #if ENABLE_FEATURE_SH_STANDALONE
2239 if (strchr(argv[0], '/') == NULL) {
2240 int a = find_applet_by_name(argv[0]);
2242 if (APPLET_IS_NOEXEC(a)) {
2243 debug_printf_exec("running applet '%s'\n", argv[0]);
2244 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
2245 run_applet_no_and_exit(a, argv);
2247 /* re-exec ourselves with the new arguments */
2248 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2249 execvp(bb_busybox_exec_path, argv);
2250 /* If they called chroot or otherwise made the binary no longer
2251 * executable, fall through */
2256 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2258 debug_printf_exec("execing '%s'\n", argv[0]);
2259 execvp(argv[0], argv);
2260 bb_perror_msg("can't exec '%s'", argv[0]);
2261 _exit(EXIT_FAILURE);
2264 static int run_list(struct pipe *pi);
2266 /* Called after [v]fork() in run_pipe()
2268 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
2269 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
2272 pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
2274 if (command->group) {
2276 bb_error_msg_and_die("nested lists are not supported on NOMMU");
2279 debug_printf_exec("pseudo_exec: run_list\n");
2280 rcode = run_list(command->group);
2281 /* OK to leak memory by not calling free_pipe_list,
2282 * since this process is about to exit */
2287 /* Can happen. See what bash does with ">foo" by itself. */
2288 debug_printf("trying to pseudo_exec null command\n");
2289 _exit(EXIT_SUCCESS);
2293 static const char *get_cmdtext(struct pipe *pi)
2299 /* This is subtle. ->cmdtext is created only on first backgrounding.
2300 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2301 * On subsequent bg argv is trashed, but we won't use it */
2304 argv = pi->cmds[0].argv;
2305 if (!argv || !argv[0]) {
2306 pi->cmdtext = xzalloc(1);
2311 do len += strlen(*argv) + 1; while (*++argv);
2312 pi->cmdtext = p = xmalloc(len);
2313 argv = pi->cmds[0].argv;
2315 len = strlen(*argv);
2316 memcpy(p, *argv, len);
2324 static void insert_bg_job(struct pipe *pi)
2326 struct pipe *thejob;
2329 /* Linear search for the ID of the job to use */
2331 for (thejob = G.job_list; thejob; thejob = thejob->next)
2332 if (thejob->jobid >= pi->jobid)
2333 pi->jobid = thejob->jobid + 1;
2335 /* Add thejob to the list of running jobs */
2337 thejob = G.job_list = xmalloc(sizeof(*thejob));
2339 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2341 thejob->next = xmalloc(sizeof(*thejob));
2342 thejob = thejob->next;
2345 /* Physically copy the struct job */
2346 memcpy(thejob, pi, sizeof(struct pipe));
2347 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2348 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2349 for (i = 0; i < pi->num_cmds; i++) {
2350 // TODO: do we really need to have so many fields which are just dead weight
2351 // at execution stage?
2352 thejob->cmds[i].pid = pi->cmds[i].pid;
2353 /* all other fields are not used and stay zero */
2355 thejob->next = NULL;
2356 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2358 /* We don't wait for background thejobs to return -- append it
2359 to the list of backgrounded thejobs and leave it alone */
2360 if (G.interactive_fd)
2361 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2362 G.last_bg_pid = thejob->cmds[0].pid;
2363 G.last_jobid = thejob->jobid;
2366 static void remove_bg_job(struct pipe *pi)
2368 struct pipe *prev_pipe;
2370 if (pi == G.job_list) {
2371 G.job_list = pi->next;
2373 prev_pipe = G.job_list;
2374 while (prev_pipe->next != pi)
2375 prev_pipe = prev_pipe->next;
2376 prev_pipe->next = pi->next;
2379 G.last_jobid = G.job_list->jobid;
2384 /* Remove a backgrounded job */
2385 static void delete_finished_bg_job(struct pipe *pi)
2388 pi->stopped_cmds = 0;
2394 /* Check to see if any processes have exited -- if they
2395 * have, figure out why and see if a job has completed */
2396 static int checkjobs(struct pipe* fg_pipe)
2406 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2409 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2410 // /* avoid doing syscall, nothing there anyway */
2413 attributes = WUNTRACED;
2414 if (fg_pipe == NULL)
2415 attributes |= WNOHANG;
2417 /* Do we do this right?
2418 * bash-3.00# sleep 20 | false
2420 * [3]+ Stopped sleep 20 | false
2421 * bash-3.00# echo $?
2422 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2425 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2426 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2427 // + killall -STOP cat
2434 // i = G.count_SIGCHLD;
2435 childpid = waitpid(-1, &status, attributes);
2436 if (childpid <= 0) {
2437 if (childpid && errno != ECHILD)
2438 bb_perror_msg("waitpid");
2439 // else /* Until next SIGCHLD, waitpid's are useless */
2440 // G.handled_SIGCHLD = i;
2443 dead = WIFEXITED(status) || WIFSIGNALED(status);
2446 if (WIFSTOPPED(status))
2447 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2448 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2449 if (WIFSIGNALED(status))
2450 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2451 childpid, WTERMSIG(status), WEXITSTATUS(status));
2452 if (WIFEXITED(status))
2453 debug_printf_jobs("pid %d exited, exitcode %d\n",
2454 childpid, WEXITSTATUS(status));
2456 /* Were we asked to wait for fg pipe? */
2458 for (i = 0; i < fg_pipe->num_cmds; i++) {
2459 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2460 if (fg_pipe->cmds[i].pid != childpid)
2462 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2464 fg_pipe->cmds[i].pid = 0;
2465 fg_pipe->alive_cmds--;
2466 if (i == fg_pipe->num_cmds - 1) {
2467 /* last process gives overall exitstatus */
2468 rcode = WEXITSTATUS(status);
2469 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2472 fg_pipe->cmds[i].is_stopped = 1;
2473 fg_pipe->stopped_cmds++;
2475 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2476 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2477 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2478 /* All processes in fg pipe have exited/stopped */
2480 if (fg_pipe->alive_cmds)
2481 insert_bg_job(fg_pipe);
2485 /* There are still running processes in the fg pipe */
2486 goto wait_more; /* do waitpid again */
2488 /* it wasnt fg_pipe, look for process in bg pipes */
2492 /* We asked to wait for bg or orphaned children */
2493 /* No need to remember exitcode in this case */
2494 for (pi = G.job_list; pi; pi = pi->next) {
2495 for (i = 0; i < pi->num_cmds; i++) {
2496 if (pi->cmds[i].pid == childpid)
2497 goto found_pi_and_prognum;
2500 /* Happens when shell is used as init process (init=/bin/sh) */
2501 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2502 continue; /* do waitpid again */
2504 found_pi_and_prognum:
2507 pi->cmds[i].pid = 0;
2509 if (!pi->alive_cmds) {
2510 if (G.interactive_fd)
2511 printf(JOB_STATUS_FORMAT, pi->jobid,
2512 "Done", pi->cmdtext);
2513 delete_finished_bg_job(pi);
2517 pi->cmds[i].is_stopped = 1;
2521 } /* while (waitpid succeeds)... */
2527 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2530 int rcode = checkjobs(fg_pipe);
2531 /* Job finished, move the shell to the foreground */
2532 p = getpgid(0); /* pgid of our process */
2533 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2534 tcsetpgrp(G.interactive_fd, p);
2539 /* run_pipe() starts all the jobs, but doesn't wait for anything
2540 * to finish. See checkjobs().
2542 * return code is normally -1, when the caller has to wait for children
2543 * to finish to determine the exit status of the pipe. If the pipe
2544 * is a simple builtin command, however, the action is done by the
2545 * time run_pipe returns, and the exit code is provided as the
2548 * The input of the pipe is always stdin, the output is always
2549 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
2550 * because it tries to avoid running the command substitution in
2551 * subshell, when that is in fact necessary. The subshell process
2552 * now has its stdout directed to the input of the appropriate pipe,
2553 * so this routine is noticeably simpler.
2555 * Returns -1 only if started some children. IOW: we have to
2556 * mask out retvals of builtins etc with 0xff!
2558 static int run_pipe(struct pipe *pi)
2562 int pipefds[2]; /* pipefds[0] is for reading */
2563 struct command *command;
2564 char **argv_expanded;
2566 const struct built_in_command *x;
2568 /* it is not always needed, but we aim to smaller code */
2569 int squirrel[] = { -1, -1, -1 };
2571 const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
2573 debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
2579 pi->stopped_cmds = 0;
2581 /* Check if this is a simple builtin (not part of a pipe).
2582 * Builtins within pipes have to fork anyway, and are handled in
2583 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
2585 command = &(pi->cmds[0]);
2587 #if ENABLE_HUSH_FUNCTIONS
2588 if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
2589 /* We "execute" function definition */
2590 bb_error_msg("here we ought to remember function definition, and go on");
2591 return EXIT_SUCCESS;
2595 if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
2596 debug_printf("non-subshell grouping\n");
2597 setup_redirects(command, squirrel);
2598 debug_printf_exec(": run_list\n");
2599 rcode = run_list(command->group) & 0xff;
2600 restore_redirects(squirrel);
2601 debug_printf_exec("run_pipe return %d\n", rcode);
2602 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2606 argv = command->argv;
2607 argv_expanded = NULL;
2609 if (single_and_fg && argv != NULL) {
2610 char **new_env = NULL;
2611 char **old_env = NULL;
2613 i = command->assignment_cnt;
2614 if (i != 0 && argv[i] == NULL) {
2615 /* assignments, but no command: set local environment */
2616 for (i = 0; argv[i] != NULL; i++) {
2617 debug_printf("local environment set: %s\n", argv[i]);
2618 p = expand_string_to_string(argv[i]);
2619 set_local_var(p, 0);
2621 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
2624 /* Expand the rest into (possibly) many strings each */
2625 argv_expanded = expand_strvec_to_strvec(argv + i);
2627 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2628 if (strcmp(argv_expanded[0], x->cmd) != 0)
2630 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2631 debug_printf("exec with redirects only\n");
2632 setup_redirects(command, NULL);
2633 rcode = EXIT_SUCCESS;
2634 goto clean_up_and_ret1;
2636 debug_printf("builtin inline %s\n", argv_expanded[0]);
2637 /* XXX setup_redirects acts on file descriptors, not FILEs.
2638 * This is perfect for work that comes after exec().
2639 * Is it really safe for inline use? Experimentally,
2640 * things seem to work with glibc. */
2641 setup_redirects(command, squirrel);
2642 new_env = expand_assignments(argv, command->assignment_cnt);
2643 old_env = putenv_all_and_save_old(new_env);
2644 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
2645 rcode = x->function(argv_expanded) & 0xff;
2646 #if ENABLE_FEATURE_SH_STANDALONE
2649 restore_redirects(squirrel);
2650 free_strings_and_unsetenv(new_env, 1);
2651 putenv_all(old_env);
2652 free(old_env); /* not free_strings()! */
2654 free(argv_expanded);
2655 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2656 debug_printf_exec("run_pipe return %d\n", rcode);
2659 #if ENABLE_FEATURE_SH_STANDALONE
2660 i = find_applet_by_name(argv_expanded[0]);
2661 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2662 setup_redirects(command, squirrel);
2663 save_nofork_data(&G.nofork_save);
2664 new_env = expand_assignments(argv, command->assignment_cnt);
2665 old_env = putenv_all_and_save_old(new_env);
2666 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
2667 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2668 goto clean_up_and_ret;
2673 /* NB: argv_expanded may already be created, and that
2674 * might include `cmd` runs! Do not rerun it! We *must*
2675 * use argv_expanded if it's non-NULL */
2677 /* Going to fork a child per each pipe member */
2681 for (i = 0; i < pi->num_cmds; i++) {
2683 volatile nommu_save_t nommu_save;
2684 nommu_save.new_env = NULL;
2685 nommu_save.old_env = NULL;
2686 nommu_save.argv = NULL;
2688 command = &(pi->cmds[i]);
2689 if (command->argv) {
2690 debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
2692 debug_printf_exec(": pipe member with no argv\n");
2694 /* pipes are inserted between pairs of commands */
2697 if ((i + 1) < pi->num_cmds)
2700 command->pid = BB_MMU ? fork() : vfork();
2701 if (!command->pid) { /* child */
2703 die_sleep = 0; /* let nofork's xfuncs die */
2705 /* Every child adds itself to new process group
2706 * with pgid == pid_of_first_child_in_pipe */
2707 if (G.run_list_level == 1 && G.interactive_fd) {
2710 if (pgrp < 0) /* true for 1st process only */
2712 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2713 /* We do it in *every* child, not just first,
2715 tcsetpgrp(G.interactive_fd, pgrp);
2719 xmove_fd(nextin, 0);
2720 xmove_fd(pipefds[1], 1); /* write end */
2722 close(pipefds[0]); /* read end */
2723 /* Like bash, explicit redirects override pipes,
2724 * and the pipe fd is available for dup'ing. */
2725 setup_redirects(command, NULL);
2727 /* Restore default handlers just prior to exec */
2728 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2730 /* Stores to nommu_save list of env vars putenv'ed
2731 * (NOMMU, on MMU we don't need that) */
2732 /* cast away volatility... */
2733 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2734 /* pseudo_exec() does not return */
2738 /* Clean up after vforked child */
2739 free(nommu_save.argv);
2740 free_strings_and_unsetenv(nommu_save.new_env, 1);
2741 putenv_all(nommu_save.old_env);
2743 free(argv_expanded);
2744 argv_expanded = NULL;
2745 if (command->pid < 0) { /* [v]fork failed */
2746 /* Clearly indicate, was it fork or vfork */
2747 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2751 /* Second and next children need to know pid of first one */
2753 pi->pgrp = command->pid;
2759 if ((i + 1) < pi->num_cmds)
2760 close(pipefds[1]); /* write end */
2761 /* Pass read (output) pipe end to next iteration */
2762 nextin = pipefds[0];
2765 if (!pi->alive_cmds) {
2766 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2770 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2774 #ifndef debug_print_tree
2775 static void debug_print_tree(struct pipe *pi, int lvl)
2777 static const char *const PIPE[] = {
2783 static const char *RES[] = {
2784 [RES_NONE ] = "NONE" ,
2787 [RES_THEN ] = "THEN" ,
2788 [RES_ELIF ] = "ELIF" ,
2789 [RES_ELSE ] = "ELSE" ,
2792 #if ENABLE_HUSH_LOOPS
2793 [RES_FOR ] = "FOR" ,
2794 [RES_WHILE] = "WHILE",
2795 [RES_UNTIL] = "UNTIL",
2797 [RES_DONE ] = "DONE" ,
2799 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2802 #if ENABLE_HUSH_CASE
2803 [RES_CASE ] = "CASE" ,
2804 [RES_MATCH] = "MATCH",
2805 [RES_CASEI] = "CASEI",
2806 [RES_ESAC ] = "ESAC" ,
2808 [RES_XXXX ] = "XXXX" ,
2809 [RES_SNTX ] = "SNTX" ,
2811 static const char *const GRPTYPE[] = {
2814 #if ENABLE_HUSH_FUNCTIONS
2823 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2824 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2826 while (prn < pi->num_cmds) {
2827 struct command *command = &pi->cmds[prn];
2828 char **argv = command->argv;
2830 fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
2831 if (command->group) {
2832 fprintf(stderr, " group %s: (argv=%p)\n",
2833 GRPTYPE[command->grp_type],
2835 debug_print_tree(command->group, lvl+1);
2839 if (argv) while (*argv) {
2840 fprintf(stderr, " '%s'", *argv);
2843 fprintf(stderr, "\n");
2852 /* NB: called by pseudo_exec, and therefore must not modify any
2853 * global data until exec/_exit (we can be a child after vfork!) */
2854 static int run_list(struct pipe *pi)
2856 #if ENABLE_HUSH_CASE
2857 char *case_word = NULL;
2859 #if ENABLE_HUSH_LOOPS
2860 struct pipe *loop_top = NULL;
2861 char *for_varname = NULL;
2862 char **for_lcur = NULL;
2863 char **for_list = NULL;
2865 smallint flag_skip = 1;
2866 smalluint rcode = 0; /* probably just for compiler */
2867 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2868 smalluint cond_code = 0;
2870 enum { cond_code = 0, };
2872 /*enum reserved_style*/ smallint rword = RES_NONE;
2873 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
2875 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
2877 #if ENABLE_HUSH_LOOPS
2878 /* Check syntax for "for" */
2879 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
2880 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
2882 /* current word is FOR or IN (BOLD in comments below) */
2883 if (cpipe->next == NULL) {
2884 syntax("malformed for");
2885 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2888 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
2889 if (cpipe->next->res_word == RES_DO)
2891 /* next word is not "do". It must be "in" then ("FOR v in ...") */
2892 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
2893 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
2895 syntax("malformed for");
2896 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2902 /* Past this point, all code paths should jump to ret: label
2903 * in order to return, no direct "return" statements please.
2904 * This helps to ensure that no memory is leaked. */
2906 ////TODO: ctrl-Z handling needs re-thinking and re-testing
2909 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2910 * We are saving state before entering outermost list ("while...done")
2911 * so that ctrl-Z will correctly background _entire_ outermost list,
2912 * not just a part of it (like "sleep 1 | exit 2") */
2913 if (++G.run_list_level == 1 && G.interactive_fd) {
2914 if (sigsetjmp(G.toplevel_jb, 1)) {
2915 /* ctrl-Z forked and we are parent; or ctrl-C.
2916 * Sighandler has longjmped us here */
2917 signal(SIGINT, SIG_IGN);
2918 signal(SIGTSTP, SIG_IGN);
2919 /* Restore level (we can be coming from deep inside
2921 G.run_list_level = 1;
2922 #if ENABLE_FEATURE_SH_STANDALONE
2923 if (G.nofork_save.saved) { /* if save area is valid */
2924 debug_printf_jobs("exiting nofork early\n");
2925 restore_nofork_data(&G.nofork_save);
2928 //// if (G.ctrl_z_flag) {
2929 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
2930 //// * Remember this child as background job */
2931 //// insert_bg_job(pi);
2933 /* ctrl-C. We just stop doing whatever we were doing */
2936 USE_HUSH_LOOPS(loop_top = NULL;)
2937 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
2941 //// /* ctrl-Z handler will store pid etc in pi */
2942 //// G.toplevel_list = pi;
2943 //// G.ctrl_z_flag = 0;
2944 ////#if ENABLE_FEATURE_SH_STANDALONE
2945 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
2947 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2948 //// signal(SIGINT, handler_ctrl_c);
2952 /* Go through list of pipes, (maybe) executing them. */
2953 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
2957 IF_HAS_KEYWORDS(rword = pi->res_word;)
2958 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
2959 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
2960 rword, cond_code, skip_more_for_this_rword);
2961 #if ENABLE_HUSH_LOOPS
2962 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
2963 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
2965 /* start of a loop: remember where loop starts */
2970 if (rword == skip_more_for_this_rword && flag_skip) {
2971 if (pi->followup == PIPE_SEQ)
2973 /* it is "<false> && CMD" or "<true> || CMD"
2974 * and we should not execute CMD */
2978 skip_more_for_this_rword = RES_XXXX;
2981 if (rword == RES_THEN) {
2982 /* "if <false> THEN cmd": skip cmd */
2986 if (rword == RES_ELSE || rword == RES_ELIF) {
2987 /* "if <true> then ... ELSE/ELIF cmd":
2988 * skip cmd and all following ones */
2993 #if ENABLE_HUSH_LOOPS
2994 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
2996 /* first loop through for */
2998 static const char encoded_dollar_at[] ALIGN1 = {
2999 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3000 }; /* encoded representation of "$@" */
3001 static const char *const encoded_dollar_at_argv[] = {
3002 encoded_dollar_at, NULL
3003 }; /* argv list with one element: "$@" */
3006 vals = (char**)encoded_dollar_at_argv;
3007 if (pi->next->res_word == RES_IN) {
3008 /* if no variable values after "in" we skip "for" */
3009 if (!pi->next->cmds[0].argv)
3011 vals = pi->next->cmds[0].argv;
3012 } /* else: "for var; do..." -> assume "$@" list */
3013 /* create list of variable values */
3014 debug_print_strings("for_list made from", vals);
3015 for_list = expand_strvec_to_strvec(vals);
3016 for_lcur = for_list;
3017 debug_print_strings("for_list", for_list);
3018 for_varname = pi->cmds[0].argv[0];
3019 pi->cmds[0].argv[0] = NULL;
3021 free(pi->cmds[0].argv[0]);
3023 /* "for" loop is over, clean up */
3027 pi->cmds[0].argv[0] = for_varname;
3030 /* insert next value from for_lcur */
3031 //TODO: does it need escaping?
3032 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3033 pi->cmds[0].assignment_cnt = 1;
3035 if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
3037 if (rword == RES_DONE) {
3038 continue; /* "done" has no cmds too */
3041 #if ENABLE_HUSH_CASE
3042 if (rword == RES_CASE) {
3043 case_word = expand_strvec_to_string(pi->cmds->argv);
3046 if (rword == RES_MATCH) {
3049 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3051 /* all prev words didn't match, does this one match? */
3052 argv = pi->cmds->argv;
3054 char *pattern = expand_string_to_string(*argv);
3055 /* TODO: which FNM_xxx flags to use? */
3056 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3058 if (cond_code == 0) { /* match! we will execute this branch */
3059 free(case_word); /* make future "word)" stop */
3067 if (rword == RES_CASEI) { /* inside of a case branch */
3069 continue; /* not matched yet, skip this pipe */
3072 /* Just pressing <enter> in shell should check for jobs.
3073 * OTOH, in non-interactive shell this is useless
3074 * and only leads to extra job checks */
3075 if (pi->num_cmds == 0) {
3076 if (G.interactive_fd)
3077 goto check_jobs_and_continue;
3081 /* After analyzing all keywords and conditions, we decided
3082 * to execute this pipe. NB: have to do checkjobs(NULL)
3083 * after run_pipe() to collect any background children,
3084 * even if list execution is to be stopped. */
3085 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3088 #if ENABLE_HUSH_LOOPS
3089 G.flag_break_continue = 0;
3091 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3093 /* we only ran a builtin: rcode is already known
3094 * and we don't need to wait for anything. */
3095 check_and_run_traps(0);
3096 #if ENABLE_HUSH_LOOPS
3097 /* was it "break" or "continue"? */
3098 if (G.flag_break_continue) {
3099 smallint fbc = G.flag_break_continue;
3100 /* we might fall into outer *loop*,
3101 * don't want to break it too */
3103 G.depth_break_continue--;
3104 if (G.depth_break_continue == 0)
3105 G.flag_break_continue = 0;
3106 /* else: e.g. "continue 2" should *break* once, *then* continue */
3107 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3108 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3109 goto check_jobs_and_break;
3110 /* "continue": simulate end of loop */
3115 } else if (pi->followup == PIPE_BG) {
3116 /* what does bash do with attempts to background builtins? */
3117 /* even bash 3.2 doesn't do that well with nested bg:
3118 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3119 * I'm NOT treating inner &'s as jobs */
3120 check_and_run_traps(0);
3122 if (G.run_list_level == 1)
3125 rcode = 0; /* EXIT_SUCCESS */
3128 if (G.run_list_level == 1 && G.interactive_fd) {
3129 /* waits for completion, then fg's main shell */
3130 rcode = checkjobs_and_fg_shell(pi);
3131 check_and_run_traps(0);
3132 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3135 { /* this one just waits for completion */
3136 rcode = checkjobs(pi);
3137 check_and_run_traps(0);
3138 debug_printf_exec(": checkjobs returned %d\n", rcode);
3142 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3143 G.last_return_code = rcode;
3145 /* Analyze how result affects subsequent commands */
3147 if (rword == RES_IF || rword == RES_ELIF)
3150 #if ENABLE_HUSH_LOOPS
3151 if (rword == RES_WHILE) {
3153 rcode = 0; /* "while false; do...done" - exitcode 0 */
3154 goto check_jobs_and_break;
3157 if (rword == RES_UNTIL) {
3159 check_jobs_and_break:
3165 if ((rcode == 0 && pi->followup == PIPE_OR)
3166 || (rcode != 0 && pi->followup == PIPE_AND)
3168 skip_more_for_this_rword = rword;
3171 check_jobs_and_continue:
3176 //// if (G.ctrl_z_flag) {
3177 //// /* ctrl-Z forked somewhere in the past, we are the child,
3178 //// * and now we completed running the list. Exit. */
3184 //// if (!G.run_list_level && G.interactive_fd) {
3185 //// signal(SIGTSTP, SIG_IGN);
3186 //// signal(SIGINT, SIG_IGN);
3189 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3190 #if ENABLE_HUSH_LOOPS
3195 #if ENABLE_HUSH_CASE
3201 /* Select which version we will use */
3202 static int run_and_free_list(struct pipe *pi)
3205 debug_printf_exec("run_and_free_list entered\n");
3207 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3208 rcode = run_list(pi);
3210 /* free_pipe_list has the side effect of clearing memory.
3211 * In the long run that function can be merged with run_list,
3212 * but doing that now would hobble the debugging effort. */
3213 free_pipe_list(pi, /* indent: */ 0);
3214 debug_printf_exec("run_and_free_list return %d\n", rcode);
3219 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3220 * as in "2>&1", that represents duplicating a file descriptor.
3221 * Return either -2 (syntax error), -1 (no &), or the number found.
3223 static int redirect_dup_num(struct in_str *input)
3225 int ch, d = 0, ok = 0;
3227 if (ch != '&') return -1;
3229 i_getch(input); /* get the & */
3233 return -3; /* "-" represents "close me" */
3235 while (isdigit(ch)) {
3236 d = d*10 + (ch-'0');
3243 bb_error_msg("ambiguous redirect");
3247 /* The src parameter allows us to peek forward to a possible &n syntax
3248 * for file descriptor duplication, e.g., "2>&1".
3249 * Return code is 0 normally, 1 if a syntax error is detected in src.
3250 * Resource errors (in xmalloc) cause the process to exit */
3251 static int setup_redirect(struct parse_context *ctx, int fd, redir_type style,
3252 struct in_str *input)
3254 struct command *command = ctx->command;
3255 struct redir_struct *redir = command->redirects;
3256 struct redir_struct *last_redir = NULL;
3258 /* Create a new redir_struct and drop it onto the end of the linked list */
3261 redir = redir->next;
3263 redir = xzalloc(sizeof(struct redir_struct));
3264 /* redir->next = NULL; */
3265 /* redir->rd_filename = NULL; */
3267 last_redir->next = redir;
3269 command->redirects = redir;
3272 redir->rd_type = style;
3273 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3275 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3277 /* Check for a '2>&1' type redirect */
3278 redir->dup = redirect_dup_num(input);
3279 if (redir->dup == -2)
3280 return 1; /* syntax error */
3281 if (redir->dup != -1) {
3282 /* Erik had a check here that the file descriptor in question
3283 * is legit; I postpone that to "run time"
3284 * A "-" representation of "close me" shows up as a -3 here */
3285 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3287 /* We do _not_ try to open the file that src points to,
3288 * since we need to return and let src be expanded first.
3289 * Set ctx->pending_redirect, so we know what to do at the
3290 * end of the next parsed word. */
3291 ctx->pending_redirect = redir;
3297 static struct pipe *new_pipe(void)
3300 pi = xzalloc(sizeof(struct pipe));
3301 /*pi->followup = 0; - deliberately invalid value */
3302 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3306 /* Command (member of a pipe) is complete. The only possible error here
3307 * is out of memory, in which case xmalloc exits. */
3308 static int done_command(struct parse_context *ctx)
3310 /* The command is really already in the pipe structure, so
3311 * advance the pipe counter and make a new, null command. */
3312 struct pipe *pi = ctx->pipe;
3313 struct command *command = ctx->command;
3316 if (command->group == NULL
3317 && command->argv == NULL
3318 && command->redirects == NULL
3320 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3321 return pi->num_cmds;
3324 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3326 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3329 /* Only real trickiness here is that the uncommitted
3330 * command structure is not counted in pi->num_cmds. */
3331 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3332 command = &pi->cmds[pi->num_cmds];
3333 memset(command, 0, sizeof(*command));
3335 ctx->command = command;
3336 /* but ctx->pipe and ctx->list_head remain unchanged */
3338 return pi->num_cmds; /* used only for 0/nonzero check */
3341 static void done_pipe(struct parse_context *ctx, pipe_style type)
3345 debug_printf_parse("done_pipe entered, followup %d\n", type);
3346 /* Close previous command */
3347 not_null = done_command(ctx);
3348 ctx->pipe->followup = type;
3349 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3350 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3351 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3353 /* Without this check, even just <enter> on command line generates
3354 * tree of three NOPs (!). Which is harmless but annoying.
3355 * IOW: it is safe to do it unconditionally.
3356 * RES_NONE case is for "for a in; do ..." (empty IN set)
3357 * to work, possibly other cases too. */
3358 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3360 debug_printf_parse("done_pipe: adding new pipe: "
3361 "not_null:%d ctx->ctx_res_w:%d\n",
3362 not_null, ctx->ctx_res_w);
3364 ctx->pipe->next = new_p;
3366 ctx->command = NULL; /* needed! */
3367 /* RES_THEN, RES_DO etc are "sticky" -
3368 * they remain set for commands inside if/while.
3369 * This is used to control execution.
3370 * RES_FOR and RES_IN are NOT sticky (needed to support
3371 * cases where variable or value happens to match a keyword):
3373 #if ENABLE_HUSH_LOOPS
3374 if (ctx->ctx_res_w == RES_FOR
3375 || ctx->ctx_res_w == RES_IN)
3376 ctx->ctx_res_w = RES_NONE;
3378 #if ENABLE_HUSH_CASE
3379 if (ctx->ctx_res_w == RES_MATCH)
3380 ctx->ctx_res_w = RES_CASEI;
3382 /* Create the memory for command, roughly:
3383 * ctx->pipe->cmds = new struct command;
3384 * ctx->command = &ctx->pipe->cmds[0];
3388 debug_printf_parse("done_pipe return\n");
3391 static void initialize_context(struct parse_context *ctx)
3393 memset(ctx, 0, sizeof(*ctx));
3394 ctx->pipe = ctx->list_head = new_pipe();
3395 /* Create the memory for command, roughly:
3396 * ctx->pipe->cmds = new struct command;
3397 * ctx->command = &ctx->pipe->cmds[0];
3403 /* If a reserved word is found and processed, parse context is modified
3404 * and 1 is returned.
3407 struct reserved_combo {
3410 unsigned char assignment_flag;
3414 FLAG_END = (1 << RES_NONE ),
3416 FLAG_IF = (1 << RES_IF ),
3417 FLAG_THEN = (1 << RES_THEN ),
3418 FLAG_ELIF = (1 << RES_ELIF ),
3419 FLAG_ELSE = (1 << RES_ELSE ),
3420 FLAG_FI = (1 << RES_FI ),
3422 #if ENABLE_HUSH_LOOPS
3423 FLAG_FOR = (1 << RES_FOR ),
3424 FLAG_WHILE = (1 << RES_WHILE),
3425 FLAG_UNTIL = (1 << RES_UNTIL),
3426 FLAG_DO = (1 << RES_DO ),
3427 FLAG_DONE = (1 << RES_DONE ),
3428 FLAG_IN = (1 << RES_IN ),
3430 #if ENABLE_HUSH_CASE
3431 FLAG_MATCH = (1 << RES_MATCH),
3432 FLAG_ESAC = (1 << RES_ESAC ),
3434 FLAG_START = (1 << RES_XXXX ),
3437 static const struct reserved_combo* match_reserved_word(o_string *word)
3439 /* Mostly a list of accepted follow-up reserved words.
3440 * FLAG_END means we are done with the sequence, and are ready
3441 * to turn the compound list into a command.
3442 * FLAG_START means the word must start a new compound list.
3444 static const struct reserved_combo reserved_list[] = {
3446 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3447 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3448 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3449 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3450 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3451 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3453 #if ENABLE_HUSH_LOOPS
3454 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3455 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3456 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3457 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3458 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3459 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3461 #if ENABLE_HUSH_CASE
3462 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3463 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3466 const struct reserved_combo *r;
3468 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3469 if (strcmp(word->data, r->literal) == 0)
3474 static int reserved_word(o_string *word, struct parse_context *ctx)
3476 #if ENABLE_HUSH_CASE
3477 static const struct reserved_combo reserved_match = {
3478 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3481 const struct reserved_combo *r;
3483 r = match_reserved_word(word);
3487 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3488 #if ENABLE_HUSH_CASE
3489 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3490 /* "case word IN ..." - IN part starts first match part */
3491 r = &reserved_match;
3494 if (r->flag == 0) { /* '!' */
3495 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3497 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3499 ctx->ctx_inverted = 1;
3502 if (r->flag & FLAG_START) {
3503 struct parse_context *new;
3504 debug_printf("push stack\n");
3505 new = xmalloc(sizeof(*new));
3506 *new = *ctx; /* physical copy */
3507 initialize_context(ctx);
3509 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3511 ctx->ctx_res_w = RES_SNTX;
3514 ctx->ctx_res_w = r->res;
3515 ctx->old_flag = r->flag;
3516 if (ctx->old_flag & FLAG_END) {
3517 struct parse_context *old;
3518 debug_printf("pop stack\n");
3519 done_pipe(ctx, PIPE_SEQ);
3521 old->command->group = ctx->list_head;
3522 old->command->grp_type = GRP_NORMAL;
3523 *ctx = *old; /* physical copy */
3526 word->o_assignment = r->assignment_flag;
3531 //TODO: many, many callers don't check error from done_word()
3533 /* Word is complete, look at it and update parsing context.
3534 * Normal return is 0. Syntax errors return 1. */
3535 static int done_word(o_string *word, struct parse_context *ctx)
3537 struct command *command = ctx->command;
3539 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3540 if (word->length == 0 && word->nonnull == 0) {
3541 debug_printf_parse("done_word return 0: true null, ignored\n");
3544 /* If this word wasn't an assignment, next ones definitely
3545 * can't be assignments. Even if they look like ones. */
3546 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3547 && word->o_assignment != WORD_IS_KEYWORD
3549 word->o_assignment = NOT_ASSIGNMENT;
3551 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3552 command->assignment_cnt++;
3553 word->o_assignment = MAYBE_ASSIGNMENT;
3556 if (ctx->pending_redirect) {
3557 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3558 * only if run as "bash", not "sh" */
3559 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3560 word->o_assignment = NOT_ASSIGNMENT;
3561 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3563 /* "{ echo foo; } echo bar" - bad */
3564 /* NB: bash allows e.g. "if true; then { echo foo; } fi". TODO? */
3565 if (command->group) {
3567 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3571 #if ENABLE_HUSH_CASE
3572 if (ctx->ctx_dsemicolon
3573 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3575 /* already done when ctx_dsemicolon was set to 1: */
3576 /* ctx->ctx_res_w = RES_MATCH; */
3577 ctx->ctx_dsemicolon = 0;
3581 if (!command->argv /* if it's the first word... */
3582 #if ENABLE_HUSH_LOOPS
3583 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3584 && ctx->ctx_res_w != RES_IN
3587 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3588 if (reserved_word(word, ctx)) {
3590 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
3591 return (ctx->ctx_res_w == RES_SNTX);
3595 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3596 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3597 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3598 /* (otherwise it's known to be not empty and is already safe) */
3600 /* exclude "$@" - it can expand to no word despite "" */
3601 char *p = word->data;
3602 while (p[0] == SPECIAL_VAR_SYMBOL
3603 && (p[1] & 0x7f) == '@'
3604 && p[2] == SPECIAL_VAR_SYMBOL
3608 if (p == word->data || p[0] != '\0') {
3609 /* saw no "$@", or not only "$@" but some
3610 * real text is there too */
3611 /* insert "empty variable" reference, this makes
3612 * e.g. "", $empty"" etc to not disappear */
3613 o_addchr(word, SPECIAL_VAR_SYMBOL);
3614 o_addchr(word, SPECIAL_VAR_SYMBOL);
3617 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3618 debug_print_strings("word appended to argv", command->argv);
3622 ctx->pending_redirect = NULL;
3624 #if ENABLE_HUSH_LOOPS
3625 /* Force FOR to have just one word (variable name) */
3626 /* NB: basically, this makes hush see "for v in ..." syntax as if
3627 * as it is "for v; in ...". FOR and IN become two pipe structs
3629 if (ctx->ctx_res_w == RES_FOR) {
3630 //TODO: check that command->argv[0] is a valid variable name!
3631 done_pipe(ctx, PIPE_SEQ);
3634 #if ENABLE_HUSH_CASE
3635 /* Force CASE to have just one word */
3636 if (ctx->ctx_res_w == RES_CASE) {
3637 done_pipe(ctx, PIPE_SEQ);
3640 debug_printf_parse("done_word return 0\n");
3644 /* If a redirect is immediately preceded by a number, that number is
3645 * supposed to tell which file descriptor to redirect. This routine
3646 * looks for such preceding numbers. In an ideal world this routine
3647 * needs to handle all the following classes of redirects...
3648 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3649 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3650 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3651 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3652 * A -1 output from this program means no valid number was found, so the
3653 * caller should use the appropriate default for this redirection.
3655 static int redirect_opt_num(o_string *o)
3661 for (num = 0; num < o->length; num++) {
3662 if (!isdigit(o->data[num])) {
3666 num = atoi(o->data);
3671 static int parse_stream(o_string *dest, struct parse_context *ctx,
3672 struct in_str *input0, const char *end_trigger);
3674 #if ENABLE_HUSH_TICK
3675 static FILE *generate_stream_from_list(struct pipe *head)
3678 int pid, channel[2];
3681 /* *** NOMMU WARNING *** */
3682 /* By using vfork here, we suspend parent till child exits or execs.
3683 * If child will not do it before it fills the pipe, it can block forever
3684 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3686 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3687 * huge=`cat TESTFILE` # will block here forever
3690 pid = BB_MMU ? fork() : vfork();
3692 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3693 if (pid == 0) { /* child */
3694 if (ENABLE_HUSH_JOB)
3695 die_sleep = 0; /* let nofork's xfuncs die */
3696 close(channel[0]); /* NB: close _first_, then move fd! */
3697 xmove_fd(channel[1], 1);
3698 /* Prevent it from trying to handle ctrl-z etc */
3700 G.run_list_level = 1;
3702 /* Process substitution is not considered to be usual
3703 * 'command execution'.
3704 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3706 set_jobctrl_signals_to_IGN();
3708 /* Note: freeing 'head' here would break NOMMU. */
3709 _exit(run_list(head));
3712 pf = fdopen(channel[0], "r");
3714 /* 'head' is freed by the caller */
3717 /* Return code is exit status of the process that is run. */
3718 static int process_command_subs(o_string *dest,
3719 struct in_str *input,
3720 const char *subst_end)
3722 int retcode, ch, eol_cnt;
3723 o_string result = NULL_O_STRING;
3724 struct parse_context inner;
3726 struct in_str pipe_str;
3728 initialize_context(&inner);
3730 /* Recursion to generate command */
3731 retcode = parse_stream(&result, &inner, input, subst_end);
3733 return retcode; /* syntax error or EOF */
3734 done_word(&result, &inner);
3735 done_pipe(&inner, PIPE_SEQ);
3738 p = generate_stream_from_list(inner.list_head);
3741 close_on_exec_on(fileno(p));
3742 setup_file_in_str(&pipe_str, p);
3744 /* Now send results of command back into original context */
3746 while ((ch = i_getch(&pipe_str)) != EOF) {
3752 o_addchr(dest, '\n');
3755 o_addQchr(dest, ch);
3758 debug_printf("done reading from pipe, pclose()ing\n");
3759 /* This is the step that waits for the child. Should be pretty
3760 * safe, since we just read an EOF from its stdout. We could try
3761 * to do better, by using waitpid, and keeping track of background jobs
3762 * at the same time. That would be a lot of work, and contrary
3763 * to the KISS philosophy of this program. */
3764 retcode = fclose(p);
3765 free_pipe_list(inner.list_head, /* indent: */ 0);
3766 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3771 static int parse_group(o_string *dest, struct parse_context *ctx,
3772 struct in_str *input, int ch)
3774 /* dest contains characters seen prior to ( or {.
3775 * Typically it's empty, but for functions defs,
3776 * it contains function name (without '()'). */
3778 const char *endch = NULL;
3779 struct parse_context sub;
3780 struct command *command = ctx->command;
3782 debug_printf_parse("parse_group entered\n");
3783 #if ENABLE_HUSH_FUNCTIONS
3784 if (ch == 'F') { /* function definition? */
3785 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3786 //command->fname = dest->data;
3787 command->grp_type = GRP_FUNCTION;
3788 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3789 memset(dest, 0, sizeof(*dest));
3792 if (command->argv /* word [word](... */
3793 || dest->length /* word(... */
3794 || dest->nonnull /* ""(... */
3797 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3800 initialize_context(&sub);
3804 command->grp_type = GRP_SUBSHELL;
3806 rcode = parse_stream(dest, &sub, input, endch);
3808 done_word(dest, &sub); /* finish off the final word in the subcontext */
3809 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3810 command->group = sub.list_head;
3812 debug_printf_parse("parse_group return %d\n", rcode);
3814 /* command remains "open", available for possible redirects */
3817 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
3818 /* Subroutines for copying $(...) and `...` things */
3819 static void add_till_backquote(o_string *dest, struct in_str *input);
3821 static void add_till_single_quote(o_string *dest, struct in_str *input)
3824 int ch = i_getch(input);
3832 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3833 static void add_till_double_quote(o_string *dest, struct in_str *input)
3836 int ch = i_getch(input);
3839 if (ch == '\\') { /* \x. Copy both chars. */
3841 ch = i_getch(input);
3847 add_till_backquote(dest, input);
3851 //if (ch == '$') ...
3854 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3856 * "Within the backquoted style of command substitution, backslash
3857 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3858 * The search for the matching backquote shall be satisfied by the first
3859 * backquote found without a preceding backslash; during this search,
3860 * if a non-escaped backquote is encountered within a shell comment,
3861 * a here-document, an embedded command substitution of the $(command)
3862 * form, or a quoted string, undefined results occur. A single-quoted
3863 * or double-quoted string that begins, but does not end, within the
3864 * "`...`" sequence produces undefined results."
3866 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3868 static void add_till_backquote(o_string *dest, struct in_str *input)
3871 int ch = i_getch(input);
3874 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3875 int ch2 = i_getch(input);
3876 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3885 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3886 * quoting and nested ()s.
3887 * "With the $(command) style of command substitution, all characters
3888 * following the open parenthesis to the matching closing parenthesis
3889 * constitute the command. Any valid shell script can be used for command,
3890 * except a script consisting solely of redirections which produces
3891 * unspecified results."
3893 * echo $(echo '(TEST)' BEST) (TEST) BEST
3894 * echo $(echo 'TEST)' BEST) TEST) BEST
3895 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3897 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
3901 int ch = i_getch(input);
3910 if (i_peek(input) == ')') {
3917 add_till_single_quote(dest, input);
3922 add_till_double_quote(dest, input);
3926 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3927 ch = i_getch(input);
3935 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
3937 /* Return code: 0 for OK, 1 for syntax error */
3938 static int handle_dollar(o_string *dest, struct in_str *input)
3941 int ch = i_peek(input); /* first character after the $ */
3942 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3944 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3948 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3950 debug_printf_parse(": '%c'\n", ch);
3951 o_addchr(dest, ch | quote_mask);
3954 if (!isalnum(ch) && ch != '_')
3958 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3959 } else if (isdigit(ch)) {
3962 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3963 debug_printf_parse(": '%c'\n", ch);
3964 o_addchr(dest, ch | quote_mask);
3965 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3966 } else switch (ch) {
3968 case '!': /* last bg pid */
3969 case '?': /* last exit code */
3970 case '#': /* number of args */
3971 case '*': /* args */
3972 case '@': /* args */
3973 goto make_one_char_var;
3975 bool first_char, all_digits;
3977 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3979 /* XXX maybe someone will try to escape the '}' */
3984 ch = i_getch(input);
3990 /* ${#var}: length of var contents */
3992 else if (isdigit(ch)) {
3998 if (expansion < 2 &&
3999 ((all_digits && !isdigit(ch)) ||
4000 (!all_digits && !isalnum(ch) && ch != '_')))
4002 /* handle parameter expansions
4003 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4008 case ':': /* null modifier */
4009 if (expansion == 0) {
4010 debug_printf_parse(": null modifier\n");
4016 #if 0 /* not implemented yet :( */
4017 case '#': /* remove prefix */
4018 case '%': /* remove suffix */
4019 if (expansion == 0) {
4020 debug_printf_parse(": remove suffix/prefix\n");
4027 case '-': /* default value */
4028 case '=': /* assign default */
4029 case '+': /* alternative */
4030 case '?': /* error indicate */
4031 debug_printf_parse(": parameter expansion\n");
4037 syntax("unterminated ${name}");
4038 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4044 debug_printf_parse(": '%c'\n", ch);
4045 o_addchr(dest, ch | quote_mask);
4049 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4055 #if ENABLE_SH_MATH_SUPPORT
4056 if (i_peek(input) == '(') {
4058 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4059 o_addchr(dest, quote_mask | '+');
4060 add_till_closing_paren(dest, input, true);
4061 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4066 #if ENABLE_HUSH_TICK
4067 //int pos = dest->length;
4068 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4069 o_addchr(dest, quote_mask | '`');
4070 add_till_closing_paren(dest, input, false);
4071 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4072 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4079 if (isalnum(ch)) { /* it's $_name or $_123 */
4085 /* still unhandled, but should be eventually */
4086 bb_error_msg("unhandled syntax: $%c", ch);
4090 o_addQchr(dest, '$');
4092 debug_printf_parse("handle_dollar return 0\n");
4096 /* Scan input, call done_word() whenever full IFS delimited word was seen.
4097 * Call done_pipe if '\n' was seen (and end_trigger != NULL).
4098 * Return code is 0 if end_trigger char is met,
4099 * -1 on EOF (but if end_trigger == NULL then return 0),
4100 * 1 for syntax error */
4101 static int parse_stream(o_string *dest, struct parse_context *ctx,
4102 struct in_str *input, const char *end_trigger)
4106 redir_type redir_style;
4107 int shadow_quote = dest->o_quote;
4110 /* Only double-quote state is handled in the state variable dest->o_quote.
4111 * A single-quote triggers a bypass of the main loop until its mate is
4112 * found. When recursing, quote state is passed in via dest->o_quote. */
4114 debug_printf_parse("parse_stream entered, end_trigger='%s' dest->o_assignment:%d\n", end_trigger, dest->o_assignment);
4119 ch = i_getch(input);
4123 next = i_peek(input);
4126 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
4127 ch, ch, m, dest->o_quote);
4128 if (m == CHAR_ORDINARY
4129 || (m != CHAR_SPECIAL && shadow_quote)
4132 syntax("unterminated \"");
4133 debug_printf_parse("parse_stream return 1: unterminated \"\n");
4136 o_addQchr(dest, ch);
4137 if ((dest->o_assignment == MAYBE_ASSIGNMENT
4138 || dest->o_assignment == WORD_IS_KEYWORD)
4140 && is_assignment(dest->data)
4142 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4146 if (m == CHAR_IFS) {
4147 if (done_word(dest, ctx)) {
4148 debug_printf_parse("parse_stream return 1: done_word!=0\n");
4153 /* If we aren't performing a substitution, treat
4154 * a newline as a command separator.
4155 * [why we don't handle it exactly like ';'? --vda] */
4156 if (end_trigger && ch == '\n') {
4157 #if ENABLE_HUSH_CASE
4158 /* "case ... in <newline> word) ..." -
4159 * newlines are ignored (but ';' wouldn't be) */
4160 if (dest->length == 0 // && argv[0] == NULL
4161 && ctx->ctx_res_w == RES_MATCH
4166 done_pipe(ctx, PIPE_SEQ);
4167 dest->o_assignment = MAYBE_ASSIGNMENT;
4171 if (!shadow_quote && strchr(end_trigger, ch)) {
4172 /* Special case: (...word) makes last word terminate,
4173 * as if ';' is seen */
4175 done_word(dest, ctx);
4177 done_pipe(ctx, PIPE_SEQ);
4178 dest->o_assignment = MAYBE_ASSIGNMENT;
4181 IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
4183 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
4191 if (dest->o_assignment == MAYBE_ASSIGNMENT) {
4192 /* ch is a special char and thus this word
4193 * cannot be an assignment: */
4194 dest->o_assignment = NOT_ASSIGNMENT;
4199 if (dest->length == 0 && !shadow_quote) {
4202 if (ch == EOF || ch == '\n')
4207 o_addQchr(dest, ch);
4213 debug_printf_parse("parse_stream return 1: \\<eof>\n");
4217 * "The backslash retains its special meaning [in "..."]
4218 * only when followed by one of the following characters:
4219 * $, `, ", \, or <newline>. A double quote may be quoted
4220 * within double quotes by preceding it with a backslash.
4221 * If enabled, history expansion will be performed unless
4222 * an ! appearing in double quotes is escaped using
4223 * a backslash. The backslash preceding the ! is not removed."
4225 if (shadow_quote) { //NOT SURE dest->o_quote) {
4226 if (strchr("$`\"\\", next) != NULL) {
4227 o_addqchr(dest, i_getch(input));
4229 o_addqchr(dest, '\\');
4232 o_addchr(dest, '\\');
4233 o_addchr(dest, i_getch(input));
4237 if (handle_dollar(dest, input) != 0) {
4238 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
4245 ch = i_getch(input);
4247 syntax("unterminated '");
4248 debug_printf_parse("parse_stream return 1: unterminated '\n");
4253 if (dest->o_assignment == NOT_ASSIGNMENT)
4254 o_addqchr(dest, ch);
4261 shadow_quote ^= 1; /* invert */
4262 if (dest->o_assignment == NOT_ASSIGNMENT)
4265 #if ENABLE_HUSH_TICK
4267 //int pos = dest->length;
4268 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4269 o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
4270 add_till_backquote(dest, input);
4271 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4272 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4277 redir_fd = redirect_opt_num(dest);
4278 done_word(dest, ctx);
4279 redir_style = REDIRECT_OVERWRITE;
4281 redir_style = REDIRECT_APPEND;
4285 else if (next == '(') {
4286 syntax(">(process) not supported");
4287 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
4291 setup_redirect(ctx, redir_fd, redir_style, input);
4294 redir_fd = redirect_opt_num(dest);
4295 done_word(dest, ctx);
4296 redir_style = REDIRECT_INPUT;
4298 redir_style = REDIRECT_HEREIS;
4300 } else if (next == '>') {
4301 redir_style = REDIRECT_IO;
4305 else if (next == '(') {
4306 syntax("<(process) not supported");
4307 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
4311 setup_redirect(ctx, redir_fd, redir_style, input);
4314 #if ENABLE_HUSH_CASE
4317 done_word(dest, ctx);
4318 done_pipe(ctx, PIPE_SEQ);
4319 #if ENABLE_HUSH_CASE
4320 /* Eat multiple semicolons, detect
4321 * whether it means something special */
4327 if (ctx->ctx_res_w == RES_CASEI) {
4328 ctx->ctx_dsemicolon = 1;
4329 ctx->ctx_res_w = RES_MATCH;
4335 /* We just finished a cmd. New one may start
4336 * with an assignment */
4337 dest->o_assignment = MAYBE_ASSIGNMENT;
4340 done_word(dest, ctx);
4343 done_pipe(ctx, PIPE_AND);
4345 done_pipe(ctx, PIPE_BG);
4349 done_word(dest, ctx);
4350 #if ENABLE_HUSH_CASE
4351 if (ctx->ctx_res_w == RES_MATCH)
4352 break; /* we are in case's "word | word)" */
4354 if (next == '|') { /* || */
4356 done_pipe(ctx, PIPE_OR);
4358 /* we could pick up a file descriptor choice here
4359 * with redirect_opt_num(), but bash doesn't do it.
4360 * "echo foo 2| cat" yields "foo 2". */
4365 #if ENABLE_HUSH_CASE
4366 /* "case... in [(]word)..." - skip '(' */
4367 if (ctx->ctx_res_w == RES_MATCH
4368 && ctx->command->argv == NULL /* not (word|(... */
4369 && dest->length == 0 /* not word(... */
4370 && dest->nonnull == 0 /* not ""(... */
4375 #if ENABLE_HUSH_FUNCTIONS
4376 if (dest->length != 0 /* not just () but word() */
4377 && dest->nonnull == 0 /* not a"b"c() */
4378 && ctx->command->argv == NULL /* it's the first word */
4379 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4380 && i_peek(input) == ')'
4381 && !match_reserved_word(dest)
4383 bb_error_msg("seems like a function definition");
4386 //TODO: do it properly.
4387 ch = i_getch(input);
4388 } while (ch == ' ' || ch == '\n');
4390 syntax("was expecting {");
4391 debug_printf_parse("parse_stream return 1\n");
4394 ch = 'F'; /* magic value */
4398 if (parse_group(dest, ctx, input, ch) != 0) {
4399 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
4404 #if ENABLE_HUSH_CASE
4405 if (ctx->ctx_res_w == RES_MATCH)
4409 /* proper use of this character is caught by end_trigger:
4410 * if we see {, we call parse_group(..., end_trigger='}')
4411 * and it will match } earlier (not here). */
4412 syntax("unexpected } or )");
4413 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
4417 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4420 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
4426 static void set_in_charmap(const char *set, int code)
4429 G.charmap[(unsigned char)*set++] = code;
4432 static void update_charmap(void)
4434 G.ifs = getenv("IFS");
4437 /* Precompute a list of 'flow through' behavior so it can be treated
4438 * quickly up front. Computation is necessary because of IFS.
4439 * Special case handling of IFS == " \t\n" is not implemented.
4440 * The charmap[] array only really needs two bits each,
4441 * and on most machines that would be faster (reduced L1 cache use).
4443 memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap));
4444 #if ENABLE_HUSH_TICK
4445 set_in_charmap("\\$\"`", CHAR_SPECIAL);
4447 set_in_charmap("\\$\"", CHAR_SPECIAL);
4449 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
4450 set_in_charmap(G.ifs, CHAR_IFS); /* are ordinary if quoted */
4453 /* Most recursion does not come through here, the exception is
4454 * from builtin_source() and builtin_eval() */
4455 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
4457 struct parse_context ctx;
4458 o_string temp = NULL_O_STRING;
4462 initialize_context(&ctx);
4464 #if ENABLE_HUSH_INTERACTIVE
4465 inp->promptmode = 0; /* PS1 */
4467 /* We will stop & execute after each ';' or '\n'.
4468 * Example: "sleep 9999; echo TEST" + ctrl-C:
4469 * TEST should be printed */
4470 temp.o_assignment = MAYBE_ASSIGNMENT;
4471 rcode = parse_stream(&temp, &ctx, inp, ";\n");
4473 if (rcode != 1 && ctx.old_flag != 0) {
4477 if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
4478 done_word(&temp, &ctx);
4479 done_pipe(&ctx, PIPE_SEQ);
4480 debug_print_tree(ctx.list_head, 0);
4481 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
4482 run_and_free_list(ctx.list_head);
4484 /* We arrive here also if rcode == 1 (error in parse_stream) */
4486 if (ctx.old_flag != 0) {
4491 /*temp.nonnull = 0; - o_free does it below */
4492 /*temp.o_quote = 0; - o_free does it below */
4493 free_pipe_list(ctx.list_head, /* indent: */ 0);
4494 /* Discard all unprocessed line input, force prompt on */
4496 #if ENABLE_HUSH_INTERACTIVE
4501 /* loop on syntax errors, return on EOF: */
4502 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
4506 static int parse_and_run_string(const char *s, int parse_flag)
4508 struct in_str input;
4509 setup_string_in_str(&input, s);
4510 return parse_and_run_stream(&input, parse_flag);
4513 static int parse_and_run_file(FILE *f)
4516 struct in_str input;
4517 setup_file_in_str(&input, f);
4518 rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
4523 /* Make sure we have a controlling tty. If we get started under a job
4524 * aware app (like bash for example), make sure we are now in charge so
4525 * we don't fight over who gets the foreground */
4526 static void setup_job_control(void)
4530 shell_pgrp = getpgrp();
4532 /* If we were ran as 'hush &',
4533 * sleep until we are in the foreground. */
4534 while (tcgetpgrp(G.interactive_fd) != shell_pgrp) {
4535 /* Send TTIN to ourself (should stop us) */
4536 kill(- shell_pgrp, SIGTTIN);
4537 shell_pgrp = getpgrp();
4540 /* We _must_ restore tty pgrp on fatal signals */
4541 set_fatal_signals_to_sigexit();
4543 /* Put ourselves in our own process group. */
4544 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
4545 /* Grab control of the terminal. */
4546 tcsetpgrp(G.interactive_fd, getpid());
4550 static int set_mode(const char cstate, const char mode)
4552 int state = (cstate == '-' ? 1 : 0);
4554 case 'n': G.fake_mode = state; break;
4555 case 'x': /*G.debug_mode = state;*/ break;
4556 default: return EXIT_FAILURE;
4558 return EXIT_SUCCESS;
4561 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4562 int hush_main(int argc, char **argv)
4564 static const struct variable const_shell_ver = {
4566 .varstr = (char*)hush_version_str,
4567 .max_len = 1, /* 0 can provoke free(name) */
4575 struct variable *cur_var;
4579 G.root_pid = getpid();
4581 /* Deal with HUSH_VERSION */
4582 G.shell_ver = const_shell_ver; /* copying struct here */
4583 G.top_var = &G.shell_ver;
4584 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4585 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4586 /* Initialize our shell local variables with the values
4587 * currently living in the environment */
4588 cur_var = G.top_var;
4591 char *value = strchr(*e, '=');
4592 if (value) { /* paranoia */
4593 cur_var->next = xzalloc(sizeof(*cur_var));
4594 cur_var = cur_var->next;
4595 cur_var->varstr = *e;
4596 cur_var->max_len = strlen(*e);
4597 cur_var->flg_export = 1;
4601 debug_printf_env("putenv '%s'\n", hush_version_str);
4602 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
4604 #if ENABLE_FEATURE_EDITING
4605 G.line_input_state = new_line_input_t(FOR_SHELL);
4607 /* XXX what should these be while sourcing /etc/profile? */
4608 G.global_argc = argc;
4609 G.global_argv = argv;
4610 /* Initialize some more globals to non-zero values */
4612 #if ENABLE_HUSH_INTERACTIVE
4613 if (ENABLE_FEATURE_EDITING)
4614 cmdedit_set_initial_prompt();
4618 if (EXIT_SUCCESS) /* otherwise is already done */
4619 G.last_return_code = EXIT_SUCCESS;
4621 if (argv[0] && argv[0][0] == '-') {
4622 debug_printf("sourcing /etc/profile\n");
4623 input = fopen_for_read("/etc/profile");
4624 if (input != NULL) {
4625 close_on_exec_on(fileno(input));
4626 parse_and_run_file(input);
4632 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
4633 while ((opt = getopt(argc, argv, "c:xins")) > 0) {
4636 G.global_argv = argv + optind;
4637 if (!argv[optind]) {
4638 /* -c 'script' (no params): prevent empty $0 */
4639 *--G.global_argv = argv[0];
4641 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
4642 G.global_argc = argc - optind;
4643 opt = parse_and_run_string(optarg, 0 /* parse_flag */);
4646 /* Well, we cannot just declare interactiveness,
4647 * we have to have some stuff (ctty, etc) */
4648 /* G.interactive_fd++; */
4651 /* "-s" means "read from stdin", but this is how we always
4652 * operate, so simply do nothing here. */
4656 if (!set_mode('-', opt))
4660 fprintf(stderr, "Usage: sh [FILE]...\n"
4661 " or: sh -c command [args]...\n\n");
4669 /* A shell is interactive if the '-i' flag was given, or if all of
4670 * the following conditions are met:
4672 * no arguments remaining or the -s flag given
4673 * standard input is a terminal
4674 * standard output is a terminal
4675 * Refer to Posix.2, the description of the 'sh' utility. */
4676 if (argv[optind] == NULL && input == stdin
4677 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4679 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
4680 debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
4681 if (G.saved_tty_pgrp >= 0) {
4682 /* try to dup to high fd#, >= 255 */
4683 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4684 if (G.interactive_fd < 0) {
4685 /* try to dup to any fd */
4686 G.interactive_fd = dup(STDIN_FILENO);
4687 if (G.interactive_fd < 0)
4689 G.interactive_fd = 0;
4691 // TODO: track & disallow any attempts of user
4692 // to (inadvertently) close/redirect it
4695 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4696 debug_printf("G.interactive_fd=%d\n", G.interactive_fd);
4697 if (G.interactive_fd) {
4698 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4699 /* Looks like they want an interactive shell */
4700 setup_job_control();
4701 /* -1 is special - makes xfuncs longjmp, not exit
4702 * (we reset die_sleep = 0 whereever we [v]fork) */
4704 if (setjmp(die_jmp)) {
4705 /* xfunc has failed! die die die */
4706 hush_exit(xfunc_error_retval);
4709 #elif ENABLE_HUSH_INTERACTIVE
4710 /* no job control compiled, only prompt/line editing */
4711 if (argv[optind] == NULL && input == stdin
4712 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4714 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4715 if (G.interactive_fd < 0) {
4716 /* try to dup to any fd */
4717 G.interactive_fd = dup(STDIN_FILENO);
4718 if (G.interactive_fd < 0)
4720 G.interactive_fd = 0;
4722 if (G.interactive_fd) {
4723 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4726 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4728 /* POSIX allows shell to re-enable SIGCHLD
4729 * even if it was SIG_IGN on entry */
4730 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
4731 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
4733 #if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
4734 if (G.interactive_fd) {
4735 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
4736 printf("Enter 'help' for a list of built-in commands.\n\n");
4740 if (argv[optind] == NULL) {
4741 opt = parse_and_run_file(stdin);
4743 debug_printf("\nrunning script '%s'\n", argv[optind]);
4744 G.global_argv = argv + optind;
4745 G.global_argc = argc - optind;
4746 input = xfopen_for_read(argv[optind]);
4747 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
4748 opt = parse_and_run_file(input);
4753 #if ENABLE_FEATURE_CLEAN_UP
4755 if (G.cwd != bb_msg_unknown)
4757 cur_var = G.top_var->next;
4759 struct variable *tmp = cur_var;
4760 if (!cur_var->max_len)
4761 free(cur_var->varstr);
4762 cur_var = cur_var->next;
4766 hush_exit(opt ? opt : G.last_return_code);
4771 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4772 int lash_main(int argc, char **argv)
4774 //bb_error_msg("lash is deprecated, please use hush instead");
4775 return hush_main(argc, argv);
4783 static int builtin_trap(char **argv)
4790 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
4793 /* No args: print all trapped. This isn't 100% correct as we should
4794 * be escaping the cmd so that it can be pasted back in ...
4796 for (i = 0; i < NSIG; ++i)
4798 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
4799 return EXIT_SUCCESS;
4804 /* if first arg is decimal: reset all specified */
4805 sig = bb_strtou(*++argv, NULL, 10);
4811 sig = get_signum(*argv++);
4812 if (sig < 0 || sig >= NSIG) {
4814 /* mimic bash message exactly */
4815 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
4820 G.traps[sig] = xstrdup(new_cmd);
4822 debug_printf("trap: setting SIG%s (%i) to '%s'",
4823 get_signame(sig), sig, G.traps[sig]);
4825 /* There is no signal for 0 (EXIT) */
4830 sigaddset(&G.blocked_set, sig);
4832 /* there was a trap handler, we are removing it
4833 * (if sig has non-DFL handling,
4834 * we don't need to do anything) */
4835 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
4837 sigdelset(&G.blocked_set, sig);
4839 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
4844 /* first arg is "-": reset all specified to default */
4845 /* first arg is "": ignore all specified */
4846 /* everything else: execute first arg upon signal */
4848 bb_error_msg("trap: invalid arguments");
4849 return EXIT_FAILURE;
4851 if (LONE_DASH(*argv))
4859 static int builtin_true(char **argv UNUSED_PARAM)
4864 static int builtin_test(char **argv)
4871 return test_main(argc, argv - argc);
4874 static int builtin_echo(char **argv)
4881 return echo_main(argc, argv - argc);
4884 static int builtin_eval(char **argv)
4886 int rcode = EXIT_SUCCESS;
4889 char *str = expand_strvec_to_string(argv + 1);
4890 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
4892 rcode = G.last_return_code;
4897 static int builtin_cd(char **argv)
4900 if (argv[1] == NULL) {
4901 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
4902 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
4903 newdir = getenv("HOME") ? : "/";
4906 if (chdir(newdir)) {
4907 printf("cd: %s: %s\n", newdir, strerror(errno));
4908 return EXIT_FAILURE;
4911 return EXIT_SUCCESS;
4914 static int builtin_exec(char **argv)
4916 if (argv[1] == NULL)
4917 return EXIT_SUCCESS; /* bash does this */
4922 // FIXME: if exec fails, bash does NOT exit! We do...
4923 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
4928 static int builtin_exit(char **argv)
4930 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
4931 //puts("exit"); /* bash does it */
4932 // TODO: warn if we have background jobs: "There are stopped jobs"
4933 // On second consecutive 'exit', exit anyway.
4934 if (argv[1] == NULL)
4935 hush_exit(G.last_return_code);
4936 /* mimic bash: exit 123abc == exit 255 + error msg */
4937 xfunc_error_retval = 255;
4938 /* bash: exit -2 == exit 254, no error msg */
4939 hush_exit(xatoi(argv[1]) & 0xff);
4942 static int builtin_export(char **argv)
4945 char *name = argv[1];
4949 // ash emits: export VAR='VAL'
4950 // bash: declare -x VAR="VAL"
4951 // (both also escape as needed (quotes, $, etc))
4956 return EXIT_SUCCESS;
4959 value = strchr(name, '=');
4961 /* They are exporting something without a =VALUE */
4962 struct variable *var;
4964 var = get_local_var(name);
4966 var->flg_export = 1;
4967 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
4968 putenv(var->varstr);
4970 /* bash does not return an error when trying to export
4971 * an undefined variable. Do likewise. */
4972 return EXIT_SUCCESS;
4975 set_local_var(xstrdup(name), 1);
4976 return EXIT_SUCCESS;
4980 /* built-in 'fg' and 'bg' handler */
4981 static int builtin_fg_bg(char **argv)
4986 if (!G.interactive_fd)
4987 return EXIT_FAILURE;
4988 /* If they gave us no args, assume they want the last backgrounded task */
4990 for (pi = G.job_list; pi; pi = pi->next) {
4991 if (pi->jobid == G.last_jobid) {
4995 bb_error_msg("%s: no current job", argv[0]);
4996 return EXIT_FAILURE;
4998 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
4999 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5000 return EXIT_FAILURE;
5002 for (pi = G.job_list; pi; pi = pi->next) {
5003 if (pi->jobid == jobnum) {
5007 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5008 return EXIT_FAILURE;
5010 // TODO: bash prints a string representation
5011 // of job being foregrounded (like "sleep 1 | cat")
5012 if (*argv[0] == 'f') {
5013 /* Put the job into the foreground. */
5014 tcsetpgrp(G.interactive_fd, pi->pgrp);
5017 /* Restart the processes in the job */
5018 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5019 for (i = 0; i < pi->num_cmds; i++) {
5020 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5021 pi->cmds[i].is_stopped = 0;
5023 pi->stopped_cmds = 0;
5025 i = kill(- pi->pgrp, SIGCONT);
5027 if (errno == ESRCH) {
5028 delete_finished_bg_job(pi);
5029 return EXIT_SUCCESS;
5031 bb_perror_msg("kill (SIGCONT)");
5035 if (*argv[0] == 'f') {
5037 return checkjobs_and_fg_shell(pi);
5039 return EXIT_SUCCESS;
5043 #if ENABLE_HUSH_HELP
5044 static int builtin_help(char **argv UNUSED_PARAM)
5046 const struct built_in_command *x;
5048 printf("\nBuilt-in commands:\n");
5049 printf("-------------------\n");
5050 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5051 printf("%s\t%s\n", x->cmd, x->descr);
5054 return EXIT_SUCCESS;
5059 static int builtin_jobs(char **argv UNUSED_PARAM)
5062 const char *status_string;
5064 for (job = G.job_list; job; job = job->next) {
5065 if (job->alive_cmds == job->stopped_cmds)
5066 status_string = "Stopped";
5068 status_string = "Running";
5070 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5072 return EXIT_SUCCESS;
5076 static int builtin_pwd(char **argv UNUSED_PARAM)
5079 return EXIT_SUCCESS;
5082 static int builtin_read(char **argv)
5085 const char *name = argv[1] ? argv[1] : "REPLY";
5087 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5088 return set_local_var(string, 0);
5091 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5092 * built-in 'set' handler
5094 * set [-abCefhmnuvx] [-o option] [argument...]
5095 * set [+abCefhmnuvx] [+o option] [argument...]
5096 * set -- [argument...]
5099 * Implementations shall support the options in both their hyphen and
5100 * plus-sign forms. These options can also be specified as options to sh.
5102 * Write out all variables and their values: set
5103 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5104 * Turn on the -x and -v options: set -xv
5105 * Unset all positional parameters: set --
5106 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5107 * Set the positional parameters to the expansion of x, even if x expands
5108 * with a leading '-' or '+': set -- $x
5110 * So far, we only support "set -- [argument...]" and some of the short names.
5112 static int builtin_set(char **argv)
5115 char **pp, **g_argv;
5116 char *arg = *++argv;
5120 for (e = G.top_var; e; e = e->next)
5122 return EXIT_SUCCESS;
5126 if (!strcmp(arg, "--")) {
5131 if (arg[0] == '+' || arg[0] == '-') {
5132 for (n = 1; arg[n]; ++n)
5133 if (set_mode(arg[0], arg[n]))
5139 } while ((arg = *++argv) != NULL);
5140 /* Now argv[0] is 1st argument */
5142 /* Only reset global_argv if we didn't process anything */
5144 return EXIT_SUCCESS;
5147 /* NB: G.global_argv[0] ($0) is never freed/changed */
5148 g_argv = G.global_argv;
5149 if (G.global_args_malloced) {
5155 G.global_args_malloced = 1;
5156 pp = xzalloc(sizeof(pp[0]) * 2);
5157 pp[0] = g_argv[0]; /* retain $0 */
5160 /* This realloc's G.global_argv */
5161 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5168 return EXIT_SUCCESS;
5170 /* Nothing known, so abort */
5172 bb_error_msg("set: %s: invalid option", arg);
5173 return EXIT_FAILURE;
5176 static int builtin_shift(char **argv)
5182 if (n >= 0 && n < G.global_argc) {
5183 if (G.global_args_malloced) {
5186 free(G.global_argv[m++]);
5189 memmove(&G.global_argv[1], &G.global_argv[n+1],
5190 G.global_argc * sizeof(G.global_argv[0]));
5191 return EXIT_SUCCESS;
5193 return EXIT_FAILURE;
5196 static int builtin_source(char **argv)
5201 if (argv[1] == NULL)
5202 return EXIT_FAILURE;
5204 /* XXX search through $PATH is missing */
5205 input = fopen_for_read(argv[1]);
5207 bb_error_msg("can't open '%s'", argv[1]);
5208 return EXIT_FAILURE;
5210 close_on_exec_on(fileno(input));
5212 /* Now run the file */
5213 /* XXX argv and argc are broken; need to save old G.global_argv
5214 * (pointer only is OK!) on this stack frame,
5215 * set G.global_argv=argv+1, recurse, and restore. */
5216 status = parse_and_run_file(input);
5221 static int builtin_umask(char **argv)
5224 const char *arg = argv[1];
5226 new_umask = bb_strtou(arg, NULL, 8);
5228 return EXIT_FAILURE;
5230 new_umask = umask(0);
5231 printf("%.3o\n", (unsigned) new_umask);
5234 return EXIT_SUCCESS;
5237 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5238 static int builtin_unset(char **argv)
5245 return EXIT_SUCCESS;
5248 if (argv[1][0] == '-') {
5249 switch (argv[1][1]) {
5251 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5253 bb_error_msg("unset: %s: invalid option", argv[1]);
5254 return EXIT_FAILURE;
5262 if (unset_local_var(argv[i]))
5265 #if ENABLE_HUSH_FUNCTIONS
5267 unset_local_func(argv[i]);
5273 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5274 static int builtin_wait(char **argv)
5276 int ret = EXIT_SUCCESS;
5279 if (*++argv == NULL) {
5280 /* Don't care about wait results */
5281 /* Note 1: must wait until there are no more children */
5282 /* Note 2: must be interruptible */
5284 * $ sleep 3 & sleep 6 & wait
5289 * $ sleep 3 & sleep 6 & wait
5293 * ^C <-- after ~4 sec from keyboard
5296 sigaddset(&G.blocked_set, SIGCHLD);
5297 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5300 if (errno == ECHILD)
5302 /* Wait for SIGCHLD or any other signal of interest */
5303 /* sigtimedwait with infinite timeout: */
5304 sig = sigwaitinfo(&G.blocked_set, NULL);
5306 sig = check_and_run_traps(sig);
5307 if (sig && sig != SIGCHLD) { /* see note 2 */
5313 sigdelset(&G.blocked_set, SIGCHLD);
5314 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5318 /* This is probably buggy wrt interruptible-ness */
5320 pid_t pid = bb_strtou(*argv, NULL, 10);
5322 /* mimic bash message */
5323 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5324 return EXIT_FAILURE;
5326 if (waitpid(pid, &status, 0) == pid) {
5327 if (WIFSIGNALED(status))
5328 ret = 128 + WTERMSIG(status);
5329 else if (WIFEXITED(status))
5330 ret = WEXITSTATUS(status);
5334 bb_perror_msg("wait %s", *argv);
5343 #if ENABLE_HUSH_LOOPS
5344 static int builtin_break(char **argv)
5346 if (G.depth_of_loop == 0) {
5347 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5348 return EXIT_SUCCESS; /* bash compat */
5350 G.flag_break_continue++; /* BC_BREAK = 1 */
5351 G.depth_break_continue = 1;
5353 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5354 if (errno || !G.depth_break_continue || argv[2]) {
5355 bb_error_msg("%s: bad arguments", argv[0]);
5356 G.flag_break_continue = BC_BREAK;
5357 G.depth_break_continue = UINT_MAX;
5360 if (G.depth_of_loop < G.depth_break_continue)
5361 G.depth_break_continue = G.depth_of_loop;
5362 return EXIT_SUCCESS;
5365 static int builtin_continue(char **argv)
5367 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5368 return builtin_break(argv);