1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
45 * Bash stuff (maybe optionally enable?):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
52 * grep for "TODO" and fix (some of them are easy)
54 * follow IFS rules more precisely, including update semantics
56 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
58 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
60 /* #include <dmalloc.h> */
67 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
72 #define LEAK_HUNTING 0
73 #define BUILD_AS_NOMMU 0
74 /* Enable/disable sanity checks. Ok to enable in production,
75 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
76 * Keeping 1 for now even in released versions.
79 /* Slightly bigger (+200 bytes), but faster hush.
80 * So far it only enables a trick with counting SIGCHLDs and forks,
81 * which allows us to do fewer waitpid's.
82 * (we can detect a case where neither forks were done nor SIGCHLDs happened
83 * and therefore waitpid will return the same result as last time)
85 #define ENABLE_HUSH_FAST 0
93 # define USE_FOR_NOMMU(...) __VA_ARGS__
94 # define USE_FOR_MMU(...)
97 #if defined SINGLE_APPLET_MAIN
98 /* STANDALONE does not make sense, and won't compile */
99 # undef CONFIG_FEATURE_SH_STANDALONE
100 # undef ENABLE_FEATURE_SH_STANDALONE
101 # undef IF_FEATURE_SH_STANDALONE
102 # define IF_FEATURE_SH_STANDALONE(...)
103 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
104 # define ENABLE_FEATURE_SH_STANDALONE 0
107 #if !ENABLE_HUSH_INTERACTIVE
108 # undef ENABLE_FEATURE_EDITING
109 # define ENABLE_FEATURE_EDITING 0
110 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
111 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
114 /* Do we support ANY keywords? */
115 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
116 # define HAS_KEYWORDS 1
117 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
118 # define IF_HAS_NO_KEYWORDS(...)
120 # define HAS_KEYWORDS 0
121 # define IF_HAS_KEYWORDS(...)
122 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
125 /* If you comment out one of these below, it will be #defined later
126 * to perform debug printfs to stderr: */
127 #define debug_printf(...) do {} while (0)
128 /* Finer-grained debug switches */
129 #define debug_printf_parse(...) do {} while (0)
130 #define debug_print_tree(a, b) do {} while (0)
131 #define debug_printf_exec(...) do {} while (0)
132 #define debug_printf_env(...) do {} while (0)
133 #define debug_printf_jobs(...) do {} while (0)
134 #define debug_printf_expand(...) do {} while (0)
135 #define debug_printf_glob(...) do {} while (0)
136 #define debug_printf_list(...) do {} while (0)
137 #define debug_printf_subst(...) do {} while (0)
138 #define debug_printf_clean(...) do {} while (0)
140 #define ERR_PTR ((void*)(long)1)
142 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
144 #define SPECIAL_VAR_SYMBOL 3
148 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
150 /* This supports saving pointers malloced in vfork child,
151 * to be freed in the parent.
154 typedef struct nommu_save_t {
156 struct variable *old_vars;
158 char **argv_from_re_execing;
162 /* The descrip member of this structure is only used to make
163 * debugging output pretty */
164 static const struct {
166 signed char default_fd;
170 { O_RDONLY, 0, "<" },
171 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
172 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
173 { O_RDONLY, 0, "<<" },
174 { O_CREAT|O_RDWR, 1, "<>" },
175 /* Should not be needed. Bogus default_fd helps in debugging */
176 /* { O_RDONLY, 77, "<<" }, */
179 typedef enum reserved_style {
188 #if ENABLE_HUSH_LOOPS
195 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
200 /* three pseudo-keywords support contrived "case" syntax: */
201 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
202 RES_MATCH , /* "word)" */
203 RES_CASE_BODY, /* "this command is inside CASE" */
210 typedef struct o_string {
212 int length; /* position where data is appended */
214 /* Protect newly added chars against globbing
215 * (by prepending \ to *, ?, [, \) */
218 /* At least some part of the string was inside '' or "",
219 * possibly empty one: word"", wo''rd etc. */
221 smallint has_empty_slot;
222 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
225 MAYBE_ASSIGNMENT = 0,
226 DEFINITELY_ASSIGNMENT = 1,
228 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
230 /* Used for initialization: o_string foo = NULL_O_STRING; */
231 #define NULL_O_STRING { NULL }
233 /* I can almost use ordinary FILE*. Is open_memstream() universally
234 * available? Where is it documented? */
235 typedef struct in_str {
237 /* eof_flag=1: last char in ->p is really an EOF */
238 char eof_flag; /* meaningless if ->p == NULL */
240 #if ENABLE_HUSH_INTERACTIVE
242 smallint promptmode; /* 0: PS1, 1: PS2 */
245 int (*get) (struct in_str *);
246 int (*peek) (struct in_str *);
248 #define i_getch(input) ((input)->get(input))
249 #define i_peek(input) ((input)->peek(input))
251 struct redir_struct {
252 struct redir_struct *next;
253 char *rd_filename; /* filename */
254 int rd_fd; /* fd to redirect */
255 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
257 smallint rd_type; /* (enum redir_type) */
258 /* note: for heredocs, rd_filename contains heredoc delimiter,
259 * and subsequently heredoc itself; and rd_dup is a bitmask:
260 * 1: do we need to trim leading tabs?
261 * 2: is heredoc quoted (<<'delim' syntax) ?
264 typedef enum redir_type {
265 REDIRECT_INVALID = 0,
267 REDIRECT_OVERWRITE = 2,
269 REDIRECT_HEREDOC = 4,
271 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
274 REDIRFD_SYNTAX_ERR = -2,
275 REDIRFD_TO_FILE = -1,
276 /* otherwise, rd_fd is redirected to rd_dup */
278 HEREDOC_SKIPTABS = 1,
284 pid_t pid; /* 0 if exited */
285 int assignment_cnt; /* how many argv[i] are assignments? */
286 smallint is_stopped; /* is the command currently running? */
287 smallint grp_type; /* GRP_xxx */
289 #define GRP_SUBSHELL 1
290 #if ENABLE_HUSH_FUNCTIONS
291 # define GRP_FUNCTION 2
293 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
296 char *group_as_string;
298 #if ENABLE_HUSH_FUNCTIONS
299 struct function *child_func;
300 /* This field is used to prevent a bug here:
301 * while...do f1() {a;}; f1; f1 {b;}; f1; done
302 * When we execute "f1() {a;}" cmd, we create new function and clear
303 * cmd->group, cmd->group_as_string, cmd->argv[0].
304 * when we execute "f1 {b;}", we notice that f1 exists,
305 * and that it's "parent cmd" struct is still "alive",
306 * we put those fields back into cmd->xxx
307 * (struct function has ->parent_cmd ptr to facilitate that).
308 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
309 * Without this trick, loop would execute a;b;b;b;...
310 * instead of correct sequence a;b;a;b;...
311 * When command is freed, it severs the link
312 * (sets ->child_func->parent_cmd to NULL).
315 char **argv; /* command name and arguments */
316 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
317 * and on execution these are substituted with their values.
318 * Substitution can make _several_ words out of one argv[n]!
319 * Example: argv[0]=='.^C*^C.' here: echo .$*.
320 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
322 struct redir_struct *redirects; /* I/O redirections */
324 /* Is there anything in this command at all? */
325 #define IS_NULL_CMD(cmd) \
326 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
331 int num_cmds; /* total number of commands in pipe */
332 int alive_cmds; /* number of commands running (not exited) */
333 int stopped_cmds; /* number of commands alive, but stopped */
335 int jobid; /* job number */
336 pid_t pgrp; /* process group ID for the job */
337 char *cmdtext; /* name of job */
339 struct command *cmds; /* array of commands in pipe */
340 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
341 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
342 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
344 typedef enum pipe_style {
350 /* Is there anything in this pipe at all? */
351 #define IS_NULL_PIPE(pi) \
352 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
354 /* This holds pointers to the various results of parsing */
355 struct parse_context {
356 /* linked list of pipes */
357 struct pipe *list_head;
358 /* last pipe (being constructed right now) */
360 /* last command in pipe (being constructed right now) */
361 struct command *command;
362 /* last redirect in command->redirects list */
363 struct redir_struct *pending_redirect;
369 smallint ctx_inverted; /* "! cmd | cmd" */
371 smallint ctx_dsemicolon; /* ";;" seen */
373 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
375 /* group we are enclosed in:
376 * example: "if pipe1; pipe2; then pipe3; fi"
377 * when we see "if" or "then", we malloc and copy current context,
378 * and make ->stack point to it. then we parse pipeN.
379 * when closing "then" / fi" / whatever is found,
380 * we move list_head into ->stack->command->group,
381 * copy ->stack into current context, and delete ->stack.
382 * (parsing of { list } and ( list ) doesn't use this method)
384 struct parse_context *stack;
388 /* On program start, environ points to initial environment.
389 * putenv adds new pointers into it, unsetenv removes them.
390 * Neither of these (de)allocates the strings.
391 * setenv allocates new strings in malloc space and does putenv,
392 * and thus setenv is unusable (leaky) for shell's purposes */
393 #define setenv(...) setenv_is_leaky_dont_use()
395 struct variable *next;
396 char *varstr; /* points to "name=" portion */
397 int max_len; /* if > 0, name is part of initial env; else name is malloced */
398 smallint flg_export; /* putenv should be done on this var */
399 smallint flg_read_only;
407 #if ENABLE_HUSH_FUNCTIONS
409 struct function *next;
411 struct command *parent_cmd;
414 char *body_as_string;
420 /* "Globals" within this file */
421 /* Sorted roughly by size (smaller offsets == smaller code) */
423 /* interactive_fd != 0 means we are an interactive shell.
424 * If we are, then saved_tty_pgrp can also be != 0, meaning
425 * that controlling tty is available. With saved_tty_pgrp == 0,
426 * job control still works, but terminal signals
427 * (^C, ^Z, ^Y, ^\) won't work at all, and background
428 * process groups can only be created with "cmd &".
429 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
430 * to give tty to the foreground process group,
431 * and will take it back when the group is stopped (^Z)
434 #if ENABLE_HUSH_INTERACTIVE
435 /* 'interactive_fd' is a fd# open to ctty, if we have one
436 * _AND_ if we decided to act interactively */
440 # define G_interactive_fd (G.interactive_fd)
442 # define G_interactive_fd 0
444 #if ENABLE_FEATURE_EDITING
445 line_input_t *line_input_state;
452 pid_t saved_tty_pgrp;
453 struct pipe *job_list;
454 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
456 # define G_saved_tty_pgrp 0
458 smallint flag_SIGINT;
459 #if ENABLE_HUSH_LOOPS
460 smallint flag_break_continue;
462 #if ENABLE_HUSH_FUNCTIONS
463 /* 0: outside of a function (or sourced file)
464 * -1: inside of a function, ok to use return builtin
465 * 1: return is invoked, skip all till end of func
467 smallint flag_return_in_progress;
470 smallint exiting; /* used to prevent EXIT trap recursion */
471 /* These four support $?, $#, and $1 */
472 smalluint last_exitcode;
473 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
474 smalluint global_args_malloced;
475 /* how many non-NULL argv's we have. NB: $# + 1 */
479 char *argv0_for_re_execing;
481 #if ENABLE_HUSH_LOOPS
482 unsigned depth_break_continue;
483 unsigned depth_of_loop;
487 struct variable *top_var; /* = &G.shell_ver (set in main()) */
488 struct variable shell_ver;
489 #if ENABLE_HUSH_FUNCTIONS
490 struct function *top_func;
492 /* Signal and trap handling */
494 unsigned count_SIGCHLD;
495 unsigned handled_SIGCHLD;
496 smallint we_have_children;
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 unsigned long memleak_value;
507 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
509 #define G (*ptr_to_globals)
510 /* Not #defining name to G.name - this quickly gets unwieldy
511 * (too many defines). Also, I actually prefer to see when a variable
512 * is global, thus "G." prefix is a useful hint */
513 #define INIT_G() do { \
514 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
518 /* Function prototypes for builtins */
519 static int builtin_cd(char **argv);
520 static int builtin_echo(char **argv);
521 static int builtin_eval(char **argv);
522 static int builtin_exec(char **argv);
523 static int builtin_exit(char **argv);
524 static int builtin_export(char **argv);
526 static int builtin_fg_bg(char **argv);
527 static int builtin_jobs(char **argv);
530 static int builtin_help(char **argv);
533 static int builtin_memleak(char **argv);
535 static int builtin_pwd(char **argv);
536 static int builtin_read(char **argv);
537 static int builtin_set(char **argv);
538 static int builtin_shift(char **argv);
539 static int builtin_source(char **argv);
540 static int builtin_test(char **argv);
541 static int builtin_trap(char **argv);
542 static int builtin_type(char **argv);
543 static int builtin_true(char **argv);
544 static int builtin_umask(char **argv);
545 static int builtin_unset(char **argv);
546 static int builtin_wait(char **argv);
547 #if ENABLE_HUSH_LOOPS
548 static int builtin_break(char **argv);
549 static int builtin_continue(char **argv);
551 #if ENABLE_HUSH_FUNCTIONS
552 static int builtin_return(char **argv);
555 /* Table of built-in functions. They can be forked or not, depending on
556 * context: within pipes, they fork. As simple commands, they do not.
557 * When used in non-forking context, they can change global variables
558 * in the parent shell process. If forked, of course they cannot.
559 * For example, 'unset foo | whatever' will parse and run, but foo will
560 * still be set at the end. */
561 struct built_in_command {
563 int (*function)(char **argv);
566 # define BLTIN(cmd, func, help) { cmd, func, help }
568 # define BLTIN(cmd, func, help) { cmd, func }
572 /* For now, echo and test are unconditionally enabled.
573 * Maybe make it configurable? */
574 static const struct built_in_command bltins[] = {
575 BLTIN("." , builtin_source , "Run commands in a file"),
576 BLTIN(":" , builtin_true , "No-op"),
577 BLTIN("[" , builtin_test , "Test condition"),
579 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
581 #if ENABLE_HUSH_LOOPS
582 BLTIN("break" , builtin_break , "Exit from a loop"),
584 BLTIN("cd" , builtin_cd , "Change directory"),
585 #if ENABLE_HUSH_LOOPS
586 BLTIN("continue", builtin_continue, "Start new loop iteration"),
588 BLTIN("echo" , builtin_echo , "Write to stdout"),
589 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
590 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
591 BLTIN("exit" , builtin_exit , "Exit"),
592 BLTIN("export" , builtin_export , "Set environment variable"),
594 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
597 BLTIN("help" , builtin_help , "List shell built-in commands"),
600 BLTIN("jobs" , builtin_jobs , "List active jobs"),
603 BLTIN("memleak" , builtin_memleak , "Debug tool"),
605 BLTIN("pwd" , builtin_pwd , "Print current directory"),
606 BLTIN("read" , builtin_read , "Input environment variable"),
607 #if ENABLE_HUSH_FUNCTIONS
608 BLTIN("return" , builtin_return , "Return from a function"),
610 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
611 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
612 BLTIN("test" , builtin_test , "Test condition"),
613 BLTIN("trap" , builtin_trap , "Trap signals"),
614 BLTIN("type" , builtin_type , "Write a description of command type"),
615 // BLTIN("ulimit" , builtin_ulimit , "Control resource limits"),
616 BLTIN("umask" , builtin_umask , "Set file creation mask"),
617 BLTIN("unset" , builtin_unset , "Unset environment variable"),
618 BLTIN("wait" , builtin_wait , "Wait for process"),
625 /* prevent disasters with G.debug_indent < 0 */
626 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
627 # define debug_enter() (G.debug_indent++)
628 # define debug_leave() (G.debug_indent--)
630 # define indent() ((void)0)
631 # define debug_enter() ((void)0)
632 # define debug_leave() ((void)0)
636 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
639 #ifndef debug_printf_parse
640 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
643 #ifndef debug_printf_exec
644 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
647 #ifndef debug_printf_env
648 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
651 #ifndef debug_printf_jobs
652 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
653 # define DEBUG_JOBS 1
655 # define DEBUG_JOBS 0
658 #ifndef debug_printf_expand
659 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
660 # define DEBUG_EXPAND 1
662 # define DEBUG_EXPAND 0
665 #ifndef debug_printf_glob
666 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
667 # define DEBUG_GLOB 1
669 # define DEBUG_GLOB 0
672 #ifndef debug_printf_list
673 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
676 #ifndef debug_printf_subst
677 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
680 #ifndef debug_printf_clean
681 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
682 # define DEBUG_CLEAN 1
684 # define DEBUG_CLEAN 0
688 static void debug_print_strings(const char *prefix, char **vv)
691 fprintf(stderr, "%s:\n", prefix);
693 fprintf(stderr, " '%s'\n", *vv++);
696 # define debug_print_strings(prefix, vv) ((void)0)
700 /* Leak hunting. Use hush_leaktool.sh for post-processing.
703 static void *xxmalloc(int lineno, size_t size)
705 void *ptr = xmalloc((size + 0xff) & ~0xff);
706 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
709 static void *xxrealloc(int lineno, void *ptr, size_t size)
711 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
712 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
715 static char *xxstrdup(int lineno, const char *str)
717 char *ptr = xstrdup(str);
718 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
721 static void xxfree(void *ptr)
723 fdprintf(2, "free %p\n", ptr);
726 #define xmalloc(s) xxmalloc(__LINE__, s)
727 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
728 #define xstrdup(s) xxstrdup(__LINE__, s)
729 #define free(p) xxfree(p)
733 /* Syntax and runtime errors. They always abort scripts.
734 * In interactive use they usually discard unparsed and/or unexecuted commands
735 * and return to the prompt.
736 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
739 # define die_if_script(lineno, fmt...) die_if_script(fmt)
740 # define syntax_error(lineno, msg) syntax_error(msg)
741 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
742 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
743 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
744 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
747 static void die_if_script(unsigned lineno, const char *fmt, ...)
752 bb_error_msg("hush.c:%u", lineno);
755 bb_verror_msg(fmt, p, NULL);
757 if (!G_interactive_fd)
761 static void syntax_error(unsigned lineno, const char *msg)
764 die_if_script(lineno, "syntax error: %s", msg);
766 die_if_script(lineno, "syntax error", NULL);
769 static void syntax_error_at(unsigned lineno, const char *msg)
771 die_if_script(lineno, "syntax error at '%s'", msg);
774 /* It so happens that all such cases are totally fatal
775 * even if shell is interactive: EOF while looking for closing
776 * delimiter. There is nowhere to read stuff from after that,
777 * it's EOF! The only choice is to terminate.
779 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
780 static void syntax_error_unterm_ch(unsigned lineno, char ch)
785 die_if_script(lineno, "syntax error: unterminated %s", msg);
789 static void syntax_error_unterm_str(unsigned lineno, const char *s)
791 die_if_script(lineno, "syntax error: unterminated %s", s);
794 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
799 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
803 # undef die_if_script
805 # undef syntax_error_at
806 # undef syntax_error_unterm_ch
807 # undef syntax_error_unterm_str
808 # undef syntax_error_unexpected_ch
810 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
811 # define syntax_error(msg) syntax_error(__LINE__, msg)
812 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
813 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
814 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
815 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
819 #if ENABLE_HUSH_INTERACTIVE
820 static void cmdedit_update_prompt(void);
822 # define cmdedit_update_prompt() ((void)0)
828 static int glob_needed(const char *s)
833 if (*s == '*' || *s == '[' || *s == '?')
840 static int is_well_formed_var_name(const char *s, char terminator)
842 if (!s || !(isalpha(*s) || *s == '_'))
845 while (isalnum(*s) || *s == '_')
847 return *s == terminator;
850 /* Replace each \x with x in place, return ptr past NUL. */
851 static char *unbackslash(char *src)
857 if ((*dst++ = *src++) == '\0')
863 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
884 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
885 v[count1 + count2] = NULL;
888 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
892 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
894 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
895 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
898 #define add_strings_to_strings(strings, add, need_to_dup) \
899 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
902 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
903 static char **add_string_to_strings(char **strings, char *add)
908 return add_strings_to_strings(strings, v, /*dup:*/ 0);
911 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
913 char **ptr = add_string_to_strings(strings, add);
914 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
917 #define add_string_to_strings(strings, add) \
918 xx_add_string_to_strings(__LINE__, strings, add)
921 static void free_strings(char **strings)
936 /* Helpers for setting new $n and restoring them back
938 typedef struct save_arg_t {
942 smallint sv_g_malloced;
945 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
949 sv->sv_argv0 = argv[0];
950 sv->sv_g_argv = G.global_argv;
951 sv->sv_g_argc = G.global_argc;
952 sv->sv_g_malloced = G.global_args_malloced;
954 argv[0] = G.global_argv[0]; /* retain $0 */
955 G.global_argv = argv;
956 G.global_args_malloced = 0;
964 static void restore_G_args(save_arg_t *sv, char **argv)
968 if (G.global_args_malloced) {
969 /* someone ran "set -- arg1 arg2 ...", undo */
971 while (*++pp) /* note: does not free $0 */
975 argv[0] = sv->sv_argv0;
976 G.global_argv = sv->sv_g_argv;
977 G.global_argc = sv->sv_g_argc;
978 G.global_args_malloced = sv->sv_g_malloced;
982 /* Basic theory of signal handling in shell
983 * ========================================
984 * This does not describe what hush does, rather, it is current understanding
985 * what it _should_ do. If it doesn't, it's a bug.
986 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
988 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
989 * is finished or backgrounded. It is the same in interactive and
990 * non-interactive shells, and is the same regardless of whether
991 * a user trap handler is installed or a shell special one is in effect.
992 * ^C or ^Z from keyboard seem to execute "at once" because it usually
993 * backgrounds (i.e. stops) or kills all members of currently running
996 * Wait builtin in interruptible by signals for which user trap is set
997 * or by SIGINT in interactive shell.
999 * Trap handlers will execute even within trap handlers. (right?)
1001 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1003 * If job control is off, backgrounded commands ("cmd &")
1004 * have SIGINT, SIGQUIT set to SIG_IGN.
1006 * Commands which are run in command substitution ("`cmd`")
1007 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1009 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1010 * by the shell from its parent.
1012 * Signals which differ from SIG_DFL action
1013 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1016 * SIGTERM (interactive): ignore
1017 * SIGHUP (interactive):
1018 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1019 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1020 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1021 * that all pipe members are stopped. Try this in bash:
1022 * while :; do :; done - ^Z does not background it
1023 * (while :; do :; done) - ^Z backgrounds it
1024 * SIGINT (interactive): wait for last pipe, ignore the rest
1025 * of the command line, show prompt. NB: ^C does not send SIGINT
1026 * to interactive shell while shell is waiting for a pipe,
1027 * since shell is bg'ed (is not in foreground process group).
1028 * Example 1: this waits 5 sec, but does not execute ls:
1029 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1030 * Example 2: this does not wait and does not execute ls:
1031 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1032 * Example 3: this does not wait 5 sec, but executes ls:
1033 * "sleep 5; ls -l" + press ^C
1035 * (What happens to signals which are IGN on shell start?)
1036 * (What happens with signal mask on shell start?)
1038 * Implementation in hush
1039 * ======================
1040 * We use in-kernel pending signal mask to determine which signals were sent.
1041 * We block all signals which we don't want to take action immediately,
1042 * i.e. we block all signals which need to have special handling as described
1043 * above, and all signals which have traps set.
1044 * After each pipe execution, we extract any pending signals via sigtimedwait()
1047 * unsigned non_DFL_mask: a mask of such "special" signals
1048 * sigset_t blocked_set: current blocked signal set
1051 * clear bit in blocked_set unless it is also in non_DFL_mask
1052 * "trap 'cmd' SIGxxx":
1053 * set bit in blocked_set (even if 'cmd' is '')
1054 * after [v]fork, if we plan to be a shell:
1055 * unblock signals with special interactive handling
1056 * (child shell is not interactive),
1057 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1058 * after [v]fork, if we plan to exec:
1059 * POSIX says pending signal mask is cleared in child - no need to clear it.
1060 * Restore blocked signal set to one inherited by shell just prior to exec.
1062 * Note: as a result, we do not use signal handlers much. The only uses
1063 * are to count SIGCHLDs
1064 * and to restore tty pgrp on signal-induced exit.
1067 SPECIAL_INTERACTIVE_SIGS = 0
1072 SPECIAL_JOB_SIGS = 0
1080 #if ENABLE_HUSH_FAST
1081 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1084 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1090 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1091 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1092 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1093 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1095 /* Restores tty foreground process group, and exits.
1096 * May be called as signal handler for fatal signal
1097 * (will resend signal to itself, producing correct exit state)
1098 * or called directly with -EXITCODE.
1099 * We also call it if xfunc is exiting. */
1100 static void sigexit(int sig) NORETURN;
1101 static void sigexit(int sig)
1103 /* Disable all signals: job control, SIGPIPE, etc. */
1104 sigprocmask_allsigs(SIG_BLOCK);
1106 /* Careful: we can end up here after [v]fork. Do not restore
1107 * tty pgrp then, only top-level shell process does that */
1108 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1109 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1111 /* Not a signal, just exit */
1115 kill_myself_with_sig(sig); /* does not return */
1119 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1120 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1124 /* Restores tty foreground process group, and exits. */
1125 static void hush_exit(int exitcode) NORETURN;
1126 static void hush_exit(int exitcode)
1128 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1129 /* Prevent recursion:
1130 * trap "echo Hi; exit" EXIT; exit
1132 char *argv[] = { NULL, G.traps[0], NULL };
1140 fflush(NULL); /* flush all streams */
1141 sigexit(- (exitcode & 0xff));
1147 static int check_and_run_traps(int sig)
1149 static const struct timespec zero_timespec = { 0, 0 };
1150 smalluint save_rcode;
1156 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1161 if (G.traps && G.traps[sig]) {
1162 if (G.traps[sig][0]) {
1163 /* We have user-defined handler */
1164 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1165 save_rcode = G.last_exitcode;
1168 G.last_exitcode = save_rcode;
1169 } /* else: "" trap, ignoring signal */
1172 /* not a trap: special action */
1174 #if ENABLE_HUSH_FAST
1177 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1181 /* Builtin was ^C'ed, make it look prettier: */
1188 /* bash is observed to signal whole process groups,
1189 * not individual processes */
1190 for (job = G.job_list; job; job = job->next) {
1193 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1194 if (kill(- job->pgrp, SIGHUP) == 0)
1195 kill(- job->pgrp, SIGCONT);
1200 default: /* ignored: */
1201 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1209 static const char *set_cwd(void)
1211 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1212 * we must not try to free(bb_msg_unknown) */
1213 if (G.cwd == bb_msg_unknown)
1215 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1217 G.cwd = bb_msg_unknown;
1223 * Shell and environment variable support
1225 static struct variable **get_ptr_to_local_var(const char *name)
1227 struct variable **pp;
1228 struct variable *cur;
1233 while ((cur = *pp) != NULL) {
1234 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1241 static struct variable *get_local_var(const char *name)
1243 struct variable **pp = get_ptr_to_local_var(name);
1249 static const char *get_local_var_value(const char *name)
1251 struct variable **pp = get_ptr_to_local_var(name);
1253 return strchr((*pp)->varstr, '=') + 1;
1257 /* str holds "NAME=VAL" and is expected to be malloced.
1258 * We take ownership of it.
1260 * 0: do not change export flag
1261 * (if creating new variable, flag will be 0)
1262 * 1: set export flag and putenv the variable
1263 * -1: clear export flag and unsetenv the variable
1264 * flg_read_only is set only when we handle -R var=val
1267 #define set_local_var(str, flg_export, flg_read_only) \
1268 set_local_var(str, flg_export)
1270 static int set_local_var(char *str, int flg_export, int flg_read_only)
1272 struct variable *cur;
1276 eq_sign = strchr(str, '=');
1277 if (!eq_sign) { /* not expected to ever happen? */
1282 name_len = eq_sign - str + 1; /* including '=' */
1283 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1285 if (strncmp(cur->varstr, str, name_len) != 0) {
1287 /* Bail out. Note that now cur points
1288 * to the last var in the linked list */
1294 /* We found an existing var with this name */
1295 if (cur->flg_read_only) {
1299 bb_error_msg("%s: readonly variable", str);
1303 if (flg_export == -1) {
1304 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1309 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1314 if (cur->max_len >= strlen(str)) {
1315 /* This one is from startup env, reuse space */
1316 strcpy(cur->varstr, str);
1319 /* max_len == 0 signifies "malloced" var, which we can
1320 * (and has to) free */
1324 goto set_str_and_exp;
1327 /* Not found - create next variable struct */
1328 cur->next = xzalloc(sizeof(*cur));
1334 cur->flg_read_only = flg_read_only;
1337 if (flg_export == 1)
1338 cur->flg_export = 1;
1339 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1340 cmdedit_update_prompt();
1341 if (cur->flg_export) {
1342 if (flg_export == -1) {
1343 cur->flg_export = 0;
1344 /* unsetenv was already done */
1346 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1347 return putenv(cur->varstr);
1353 static int unset_local_var_len(const char *name, int name_len)
1355 struct variable *cur;
1356 struct variable **var_pp;
1359 return EXIT_SUCCESS;
1360 var_pp = &G.top_var;
1361 while ((cur = *var_pp) != NULL) {
1362 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1363 if (cur->flg_read_only) {
1364 bb_error_msg("%s: readonly variable", name);
1365 return EXIT_FAILURE;
1367 *var_pp = cur->next;
1368 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1369 bb_unsetenv(cur->varstr);
1370 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1371 cmdedit_update_prompt();
1375 return EXIT_SUCCESS;
1377 var_pp = &cur->next;
1379 return EXIT_SUCCESS;
1382 static int unset_local_var(const char *name)
1384 return unset_local_var_len(name, strlen(name));
1387 static void unset_vars(char **strings)
1395 const char *eq = strchrnul(*v, '=');
1396 unset_local_var_len(*v, (int)(eq - *v));
1402 #if ENABLE_SH_MATH_SUPPORT
1403 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1404 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1405 static char *endofname(const char *name)
1413 if (!is_in_name(*p))
1419 static void arith_set_local_var(const char *name, const char *val, int flags)
1421 /* arith code doesnt malloc space, so do it for it */
1422 char *var = xasprintf("%s=%s", name, val);
1423 set_local_var(var, flags, 0);
1429 * Helpers for "var1=val1 var2=val2 cmd" feature
1431 static void add_vars(struct variable *var)
1433 struct variable *next;
1437 var->next = G.top_var;
1439 if (var->flg_export) {
1440 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1441 putenv(var->varstr);
1443 debug_printf_env("%s: restoring local '%s'\n", __func__, var->varstr);
1449 static struct variable *set_vars_and_save_old(char **strings)
1452 struct variable *old = NULL;
1458 struct variable *var_p;
1459 struct variable **var_pp;
1462 eq = strchr(*s, '=');
1465 var_pp = get_ptr_to_local_var(*s);
1468 /* Remove variable from global linked list */
1470 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1471 *var_pp = var_p->next;
1472 /* Add it to returned list */
1476 set_local_var(*s, 1, 0);
1487 static int static_get(struct in_str *i)
1496 static int static_peek(struct in_str *i)
1501 #if ENABLE_HUSH_INTERACTIVE
1503 static void cmdedit_update_prompt(void)
1505 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1506 G.PS1 = get_local_var_value("PS1");
1509 G.PS2 = get_local_var_value("PS2");
1517 static const char* setup_prompt_string(int promptmode)
1519 const char *prompt_str;
1520 debug_printf("setup_prompt_string %d ", promptmode);
1521 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1522 /* Set up the prompt */
1523 if (promptmode == 0) { /* PS1 */
1525 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1530 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1531 debug_printf("result '%s'\n", prompt_str);
1535 static void get_user_input(struct in_str *i)
1538 const char *prompt_str;
1540 prompt_str = setup_prompt_string(i->promptmode);
1541 #if ENABLE_FEATURE_EDITING
1542 /* Enable command line editing only while a command line
1543 * is actually being read */
1546 /* buglet: SIGINT will not make new prompt to appear _at once_,
1547 * only after <Enter>. (^C will work) */
1548 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1549 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1550 check_and_run_traps(0);
1551 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1552 i->eof_flag = (r < 0);
1553 if (i->eof_flag) { /* EOF/error detected */
1554 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1555 G.user_input_buf[1] = '\0';
1560 fputs(prompt_str, stdout);
1562 G.user_input_buf[0] = r = fgetc(i->file);
1563 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1564 //do we need check_and_run_traps(0)? (maybe only if stdin)
1565 } while (G.flag_SIGINT);
1566 i->eof_flag = (r == EOF);
1568 i->p = G.user_input_buf;
1571 #endif /* INTERACTIVE */
1573 /* This is the magic location that prints prompts
1574 * and gets data back from the user */
1575 static int file_get(struct in_str *i)
1579 /* If there is data waiting, eat it up */
1580 if (i->p && *i->p) {
1581 #if ENABLE_HUSH_INTERACTIVE
1585 if (i->eof_flag && !*i->p)
1587 /* note: ch is never NUL */
1589 /* need to double check i->file because we might be doing something
1590 * more complicated by now, like sourcing or substituting. */
1591 #if ENABLE_HUSH_INTERACTIVE
1592 if (G_interactive_fd && i->promptme && i->file == stdin) {
1595 } while (!*i->p); /* need non-empty line */
1596 i->promptmode = 1; /* PS2 */
1601 do ch = fgetc(i->file); while (ch == '\0');
1603 debug_printf("file_get: got '%c' %d\n", ch, ch);
1604 #if ENABLE_HUSH_INTERACTIVE
1611 /* All callers guarantee this routine will never
1612 * be used right after a newline, so prompting is not needed.
1614 static int file_peek(struct in_str *i)
1617 if (i->p && *i->p) {
1618 if (i->eof_flag && !i->p[1])
1621 /* note: ch is never NUL */
1623 do ch = fgetc(i->file); while (ch == '\0');
1624 i->eof_flag = (ch == EOF);
1625 i->peek_buf[0] = ch;
1626 i->peek_buf[1] = '\0';
1628 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1632 static void setup_file_in_str(struct in_str *i, FILE *f)
1634 i->peek = file_peek;
1636 #if ENABLE_HUSH_INTERACTIVE
1638 i->promptmode = 0; /* PS1 */
1644 static void setup_string_in_str(struct in_str *i, const char *s)
1646 i->peek = static_peek;
1647 i->get = static_get;
1648 #if ENABLE_HUSH_INTERACTIVE
1650 i->promptmode = 0; /* PS1 */
1660 #define B_CHUNK (32 * sizeof(char*))
1662 static void o_reset_to_empty_unquoted(o_string *o)
1670 static void o_free(o_string *o)
1673 memset(o, 0, sizeof(*o));
1676 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1681 static void o_grow_by(o_string *o, int len)
1683 if (o->length + len > o->maxlen) {
1684 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1685 o->data = xrealloc(o->data, 1 + o->maxlen);
1689 static void o_addchr(o_string *o, int ch)
1691 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1693 o->data[o->length] = ch;
1695 o->data[o->length] = '\0';
1698 static void o_addblock(o_string *o, const char *str, int len)
1701 memcpy(&o->data[o->length], str, len);
1703 o->data[o->length] = '\0';
1707 static void o_addstr(o_string *o, const char *str)
1709 o_addblock(o, str, strlen(str));
1711 static void nommu_addchr(o_string *o, int ch)
1717 # define nommu_addchr(o, str) ((void)0)
1720 static void o_addstr_with_NUL(o_string *o, const char *str)
1722 o_addblock(o, str, strlen(str) + 1);
1725 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1730 && (*str != '*' && *str != '?' && *str != '[')
1738 /* My analysis of quoting semantics tells me that state information
1739 * is associated with a destination, not a source.
1741 static void o_addqchr(o_string *o, int ch)
1744 char *found = strchr("*?[\\", ch);
1749 o->data[o->length] = '\\';
1752 o->data[o->length] = ch;
1754 o->data[o->length] = '\0';
1757 static void o_addQchr(o_string *o, int ch)
1760 if (o->o_escape && strchr("*?[\\", ch)) {
1762 o->data[o->length] = '\\';
1766 o->data[o->length] = ch;
1768 o->data[o->length] = '\0';
1771 static void o_addQstr(o_string *o, const char *str, int len)
1774 o_addblock(o, str, len);
1780 int ordinary_cnt = strcspn(str, "*?[\\");
1781 if (ordinary_cnt > len) /* paranoia */
1783 o_addblock(o, str, ordinary_cnt);
1784 if (ordinary_cnt == len)
1786 str += ordinary_cnt;
1787 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1791 if (ch) { /* it is necessarily one of "*?[\\" */
1793 o->data[o->length] = '\\';
1797 o->data[o->length] = ch;
1799 o->data[o->length] = '\0';
1803 /* A special kind of o_string for $VAR and `cmd` expansion.
1804 * It contains char* list[] at the beginning, which is grown in 16 element
1805 * increments. Actual string data starts at the next multiple of 16 * (char*).
1806 * list[i] contains an INDEX (int!) into this string data.
1807 * It means that if list[] needs to grow, data needs to be moved higher up
1808 * but list[i]'s need not be modified.
1809 * NB: remembering how many list[i]'s you have there is crucial.
1810 * o_finalize_list() operation post-processes this structure - calculates
1811 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1813 #if DEBUG_EXPAND || DEBUG_GLOB
1814 static void debug_print_list(const char *prefix, o_string *o, int n)
1816 char **list = (char**)o->data;
1817 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1821 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1822 prefix, list, n, string_start, o->length, o->maxlen);
1825 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1826 o->data + (int)list[i] + string_start,
1827 o->data + (int)list[i] + string_start);
1831 const char *p = o->data + (int)list[n - 1] + string_start;
1833 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1837 # define debug_print_list(prefix, o, n) ((void)0)
1840 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1841 * in list[n] so that it points past last stored byte so far.
1842 * It returns n+1. */
1843 static int o_save_ptr_helper(o_string *o, int n)
1845 char **list = (char**)o->data;
1849 if (!o->has_empty_slot) {
1850 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1851 string_len = o->length - string_start;
1852 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1853 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1854 /* list[n] points to string_start, make space for 16 more pointers */
1855 o->maxlen += 0x10 * sizeof(list[0]);
1856 o->data = xrealloc(o->data, o->maxlen + 1);
1857 list = (char**)o->data;
1858 memmove(list + n + 0x10, list + n, string_len);
1859 o->length += 0x10 * sizeof(list[0]);
1861 debug_printf_list("list[%d]=%d string_start=%d\n",
1862 n, string_len, string_start);
1865 /* We have empty slot at list[n], reuse without growth */
1866 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1867 string_len = o->length - string_start;
1868 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1869 n, string_len, string_start);
1870 o->has_empty_slot = 0;
1872 list[n] = (char*)(ptrdiff_t)string_len;
1876 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1877 static int o_get_last_ptr(o_string *o, int n)
1879 char **list = (char**)o->data;
1880 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1882 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1885 /* o_glob performs globbing on last list[], saving each result
1886 * as a new list[]. */
1887 static int o_glob(o_string *o, int n)
1893 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1895 return o_save_ptr_helper(o, n);
1896 pattern = o->data + o_get_last_ptr(o, n);
1897 debug_printf_glob("glob pattern '%s'\n", pattern);
1898 if (!glob_needed(pattern)) {
1900 o->length = unbackslash(pattern) - o->data;
1901 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1902 return o_save_ptr_helper(o, n);
1905 memset(&globdata, 0, sizeof(globdata));
1906 gr = glob(pattern, 0, NULL, &globdata);
1907 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1908 if (gr == GLOB_NOSPACE)
1909 bb_error_msg_and_die("out of memory during glob");
1910 if (gr == GLOB_NOMATCH) {
1911 globfree(&globdata);
1914 if (gr != 0) { /* GLOB_ABORTED ? */
1915 /* TODO: testcase for bad glob pattern behavior */
1916 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1918 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1919 char **argv = globdata.gl_pathv;
1920 o->length = pattern - o->data; /* "forget" pattern */
1922 o_addstr_with_NUL(o, *argv);
1923 n = o_save_ptr_helper(o, n);
1929 globfree(&globdata);
1931 debug_print_list("o_glob returning", o, n);
1935 /* If o->o_glob == 1, glob the string so far remembered.
1936 * Otherwise, just finish current list[] and start new */
1937 static int o_save_ptr(o_string *o, int n)
1939 if (o->o_glob) { /* if globbing is requested */
1940 /* If o->has_empty_slot, list[n] was already globbed
1941 * (if it was requested back then when it was filled)
1942 * so don't do that again! */
1943 if (!o->has_empty_slot)
1944 return o_glob(o, n); /* o_save_ptr_helper is inside */
1946 return o_save_ptr_helper(o, n);
1949 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1950 static char **o_finalize_list(o_string *o, int n)
1955 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1957 debug_print_list("finalized", o, n);
1958 debug_printf_expand("finalized n:%d\n", n);
1959 list = (char**)o->data;
1960 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1964 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1970 /* Expansion can recurse */
1971 #if ENABLE_HUSH_TICK
1972 static int process_command_subs(o_string *dest, const char *s);
1974 static char *expand_string_to_string(const char *str);
1976 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1977 parse_stream_dquoted(dest, input, dquote_end)
1979 static int parse_stream_dquoted(o_string *as_string,
1981 struct in_str *input,
1984 /* expand_strvec_to_strvec() takes a list of strings, expands
1985 * all variable references within and returns a pointer to
1986 * a list of expanded strings, possibly with larger number
1987 * of strings. (Think VAR="a b"; echo $VAR).
1988 * This new list is allocated as a single malloc block.
1989 * NULL-terminated list of char* pointers is at the beginning of it,
1990 * followed by strings themself.
1991 * Caller can deallocate entire list by single free(list). */
1993 /* Store given string, finalizing the word and starting new one whenever
1994 * we encounter IFS char(s). This is used for expanding variable values.
1995 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1996 static int expand_on_ifs(o_string *output, int n, const char *str)
1999 int word_len = strcspn(str, G.ifs);
2001 if (output->o_escape || !output->o_glob)
2002 o_addQstr(output, str, word_len);
2003 else /* protect backslashes against globbing up :) */
2004 o_addblock_duplicate_backslash(output, str, word_len);
2007 if (!*str) /* EOL - do not finalize word */
2009 o_addchr(output, '\0');
2010 debug_print_list("expand_on_ifs", output, n);
2011 n = o_save_ptr(output, n);
2012 str += strspn(str, G.ifs); /* skip ifs chars */
2014 debug_print_list("expand_on_ifs[1]", output, n);
2018 /* Helper to expand $((...)) and heredoc body. These act as if
2019 * they are in double quotes, with the exception that they are not :).
2020 * Just the rules are similar: "expand only $var and `cmd`"
2022 * Returns malloced string.
2023 * As an optimization, we return NULL if expansion is not needed.
2025 static char *expand_pseudo_dquoted(const char *str)
2028 struct in_str input;
2029 o_string dest = NULL_O_STRING;
2031 if (strchr(str, '$') == NULL
2032 #if ENABLE_HUSH_TICK
2033 && strchr(str, '`') == NULL
2039 /* We need to expand. Example:
2040 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2042 setup_string_in_str(&input, str);
2043 parse_stream_dquoted(NULL, &dest, &input, EOF);
2044 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2045 exp_str = expand_string_to_string(dest.data);
2046 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2047 o_free_unsafe(&dest);
2051 /* Expand all variable references in given string, adding words to list[]
2052 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2053 * to be filled). This routine is extremely tricky: has to deal with
2054 * variables/parameters with whitespace, $* and $@, and constructs like
2055 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2056 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2058 /* or_mask is either 0 (normal case) or 0x80 -
2059 * expansion of right-hand side of assignment == 1-element expand.
2060 * It will also do no globbing, and thus we must not backslash-quote!
2067 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
2068 debug_print_list("expand_vars_to_list", output, n);
2069 n = o_save_ptr(output, n);
2070 debug_print_list("expand_vars_to_list[0]", output, n);
2072 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2075 char *dyn_val = NULL;
2076 const char *val = NULL;
2077 #if ENABLE_HUSH_TICK
2078 o_string subst_result = NULL_O_STRING;
2080 #if ENABLE_SH_MATH_SUPPORT
2081 char arith_buf[sizeof(arith_t)*3 + 2];
2083 o_addblock(output, arg, p - arg);
2084 debug_print_list("expand_vars_to_list[1]", output, n);
2086 p = strchr(p, SPECIAL_VAR_SYMBOL);
2088 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2089 /* "$@" is special. Even if quoted, it can still
2090 * expand to nothing (not even an empty string) */
2091 if ((first_ch & 0x7f) != '@')
2092 ored_ch |= first_ch;
2094 switch (first_ch & 0x7f) {
2095 /* Highest bit in first_ch indicates that var is double-quoted */
2097 val = utoa(G.root_pid);
2099 case '!': /* bg pid */
2100 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2102 case '?': /* exitcode */
2103 val = utoa(G.last_exitcode);
2105 case '#': /* argc */
2106 if (arg[1] != SPECIAL_VAR_SYMBOL)
2107 /* actually, it's a ${#var} */
2109 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2114 if (!G.global_argv[i])
2116 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2117 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2118 smallint sv = output->o_escape;
2119 /* unquoted var's contents should be globbed, so don't escape */
2120 output->o_escape = 0;
2121 while (G.global_argv[i]) {
2122 n = expand_on_ifs(output, n, G.global_argv[i]);
2123 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2124 if (G.global_argv[i++][0] && G.global_argv[i]) {
2125 /* this argv[] is not empty and not last:
2126 * put terminating NUL, start new word */
2127 o_addchr(output, '\0');
2128 debug_print_list("expand_vars_to_list[2]", output, n);
2129 n = o_save_ptr(output, n);
2130 debug_print_list("expand_vars_to_list[3]", output, n);
2133 output->o_escape = sv;
2135 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2136 * and in this case should treat it like '$*' - see 'else...' below */
2137 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2139 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2140 if (++i >= G.global_argc)
2142 o_addchr(output, '\0');
2143 debug_print_list("expand_vars_to_list[4]", output, n);
2144 n = o_save_ptr(output, n);
2146 } else { /* quoted $*: add as one word */
2148 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2149 if (!G.global_argv[++i])
2152 o_addchr(output, G.ifs[0]);
2156 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2157 /* "Empty variable", used to make "" etc to not disappear */
2161 #if ENABLE_HUSH_TICK
2162 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2165 /* Can't just stuff it into output o_string,
2166 * expanded result may need to be globbed
2167 * and $IFS-splitted */
2168 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2169 process_command_subs(&subst_result, arg);
2170 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2171 val = subst_result.data;
2174 #if ENABLE_SH_MATH_SUPPORT
2175 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2176 arith_eval_hooks_t hooks;
2181 arg++; /* skip '+' */
2182 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2183 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2185 exp_str = expand_pseudo_dquoted(arg);
2186 hooks.lookupvar = get_local_var_value;
2187 hooks.setvar = arith_set_local_var;
2188 hooks.endofname = endofname;
2189 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2193 const char *msg = "error in arithmetic";
2196 msg = "exponent less than 0";
2199 msg = "divide by 0";
2202 msg = "expression recursion loop detected";
2207 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2208 sprintf(arith_buf, arith_t_fmt, res);
2213 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2215 bool exp_len = false;
2216 bool exp_null = false;
2218 char exp_save = exp_save; /* for compiler */
2219 char exp_op = exp_op; /* for compiler */
2220 char *exp_word = exp_word; /* for compiler */
2224 arg[0] = first_ch & 0x7f;
2226 /* prepare for expansions */
2227 if (var[0] == '#') {
2228 /* handle length expansion ${#var} */
2232 /* maybe handle parameter expansion */
2233 exp_off = strcspn(var, ":-=+?%#");
2237 exp_save = var[exp_off];
2238 exp_null = exp_save == ':';
2239 exp_word = var + exp_off;
2242 exp_op = *exp_word++;
2243 var[exp_off] = '\0';
2247 /* lookup the variable in question */
2248 if (isdigit(var[0])) {
2249 /* handle_dollar() should have vetted var for us */
2251 if (i < G.global_argc)
2252 val = G.global_argv[i];
2253 /* else val remains NULL: $N with too big N */
2255 val = get_local_var_value(var);
2257 /* handle any expansions */
2259 debug_printf_expand("expand: length of '%s' = ", val);
2260 val = utoa(val ? strlen(val) : 0);
2261 debug_printf_expand("%s\n", val);
2262 } else if (exp_off) {
2263 if (exp_op == '%' || exp_op == '#') {
2265 /* we need to do a pattern match */
2268 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2269 if (exp_op == *exp_word) /* ## or %% */
2271 val = dyn_val = xstrdup(val);
2272 loc = scan(dyn_val, exp_word, match_at_left);
2273 if (match_at_left) /* # or ## */
2275 else if (loc) /* % or %% and match was found */
2279 /* we need to do an expansion */
2280 int exp_test = (!val || (exp_null && !val[0]));
2282 exp_test = !exp_test;
2283 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2284 exp_null ? "true" : "false", exp_test);
2286 if (exp_op == '?') {
2287 //TODO: how interactive bash aborts expansion mid-command?
2288 /* ${var?[error_msg_if_unset]} */
2289 /* ${var:?[error_msg_if_unset_or_null]} */
2290 /* mimic bash message */
2291 die_if_script("%s: %s",
2293 exp_word[0] ? exp_word : "parameter null or not set"
2299 if (exp_op == '=') {
2300 /* ${var=[word]} or ${var:=[word]} */
2301 if (isdigit(var[0]) || var[0] == '#') {
2302 /* mimic bash message */
2303 die_if_script("$%s: cannot assign in this way", var);
2306 char *new_var = xasprintf("%s=%s", var, val);
2307 set_local_var(new_var, 0, 0);
2313 var[exp_off] = exp_save;
2317 #if ENABLE_HUSH_TICK
2320 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2321 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2323 /* unquoted var's contents should be globbed, so don't escape */
2324 smallint sv = output->o_escape;
2325 output->o_escape = 0;
2326 n = expand_on_ifs(output, n, val);
2328 output->o_escape = sv;
2330 } else { /* quoted $VAR, val will be appended below */
2331 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2334 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2337 o_addQstr(output, val, strlen(val));
2340 /* Do the check to avoid writing to a const string */
2341 if (*p != SPECIAL_VAR_SYMBOL)
2342 *p = SPECIAL_VAR_SYMBOL;
2344 #if ENABLE_HUSH_TICK
2345 o_free(&subst_result);
2348 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2351 debug_print_list("expand_vars_to_list[a]", output, n);
2352 /* this part is literal, and it was already pre-quoted
2353 * if needed (much earlier), do not use o_addQstr here! */
2354 o_addstr_with_NUL(output, arg);
2355 debug_print_list("expand_vars_to_list[b]", output, n);
2356 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2357 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2360 /* allow to reuse list[n] later without re-growth */
2361 output->has_empty_slot = 1;
2363 o_addchr(output, '\0');
2368 static char **expand_variables(char **argv, int or_mask)
2373 o_string output = NULL_O_STRING;
2375 if (or_mask & 0x100) {
2376 output.o_escape = 1; /* protect against globbing for "$var" */
2377 /* (unquoted $var will temporarily switch it off) */
2384 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2387 debug_print_list("expand_variables", &output, n);
2389 /* output.data (malloced in one block) gets returned in "list" */
2390 list = o_finalize_list(&output, n);
2391 debug_print_strings("expand_variables[1]", list);
2395 static char **expand_strvec_to_strvec(char **argv)
2397 return expand_variables(argv, 0x100);
2400 /* Used for expansion of right hand of assignments */
2401 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2403 static char *expand_string_to_string(const char *str)
2405 char *argv[2], **list;
2407 argv[0] = (char*)str;
2409 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2411 if (!list[0] || list[1])
2412 bb_error_msg_and_die("BUG in varexp2");
2413 /* actually, just move string 2*sizeof(char*) bytes back */
2414 overlapping_strcpy((char*)list, list[0]);
2415 unbackslash((char*)list);
2416 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2420 /* Used for "eval" builtin */
2421 static char* expand_strvec_to_string(char **argv)
2425 list = expand_variables(argv, 0x80);
2426 /* Convert all NULs to spaces */
2431 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2432 bb_error_msg_and_die("BUG in varexp3");
2433 /* bash uses ' ' regardless of $IFS contents */
2438 overlapping_strcpy((char*)list, list[0]);
2439 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2443 static char **expand_assignments(char **argv, int count)
2447 /* Expand assignments into one string each */
2448 for (i = 0; i < count; i++) {
2449 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2457 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2459 static void reset_traps_to_defaults(void)
2461 /* This function is always called in a child shell
2462 * after fork (not vfork, NOMMU doesn't use this function).
2463 * Child shells are not interactive.
2464 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2465 * Testcase: (while :; do :; done) + ^Z should background.
2466 * Same goes for SIGTERM, SIGHUP, SIGINT.
2471 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2474 /* Stupid. It can be done with *single* &= op, but we can't use
2475 * the fact that G.blocked_set is implemented as a bitmask... */
2476 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2480 sigdelset(&G.blocked_set, sig);
2487 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2488 mask = G.non_DFL_mask;
2489 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2493 G.traps[sig] = NULL;
2494 /* There is no signal for 0 (EXIT) */
2497 /* There was a trap handler, we are removing it.
2498 * But if sig still has non-DFL handling,
2499 * we should not unblock it. */
2502 sigdelset(&G.blocked_set, sig);
2504 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2509 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2510 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2512 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2513 char *heredoc_argv[4];
2514 struct variable *cur;
2515 #if ENABLE_HUSH_FUNCTIONS
2516 struct function *funcp;
2521 if (!g_argv0) { /* heredoc */
2522 argv = heredoc_argv;
2523 argv[0] = (char *) G.argv0_for_re_execing;
2524 argv[1] = (char *) "-<";
2525 argv[2] = (char *) s;
2527 pp = &argv[3]; /* used as pointer to empty environment */
2531 sprintf(param_buf, "-$%x:%x:%x" IF_HUSH_LOOPS(":%x")
2532 , (unsigned) G.root_pid
2533 , (unsigned) G.last_bg_pid
2534 , (unsigned) G.last_exitcode
2535 IF_HUSH_LOOPS(, G.depth_of_loop)
2537 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2538 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2541 for (cur = G.top_var; cur; cur = cur->next) {
2542 if (!cur->flg_export || cur->flg_read_only)
2545 #if ENABLE_HUSH_FUNCTIONS
2546 for (funcp = G.top_func; funcp; funcp = funcp->next)
2552 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2553 *pp++ = (char *) G.argv0_for_re_execing;
2555 for (cur = G.top_var; cur; cur = cur->next) {
2556 if (cur->varstr == hush_version_str)
2558 if (cur->flg_read_only) {
2559 *pp++ = (char *) "-R";
2560 *pp++ = cur->varstr;
2561 } else if (!cur->flg_export) {
2562 *pp++ = (char *) "-V";
2563 *pp++ = cur->varstr;
2566 #if ENABLE_HUSH_FUNCTIONS
2567 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2568 *pp++ = (char *) "-F";
2569 *pp++ = funcp->name;
2570 *pp++ = funcp->body_as_string;
2573 /* We can pass activated traps here. Say, -Tnn:trap_string
2575 * However, POSIX says that subshells reset signals with traps
2577 * I tested bash-3.2 and it not only does that with true subshells
2578 * of the form ( list ), but with any forked children shells.
2579 * I set trap "echo W" WINCH; and then tried:
2581 * { echo 1; sleep 20; echo 2; } &
2582 * while true; do echo 1; sleep 20; echo 2; break; done &
2583 * true | { echo 1; sleep 20; echo 2; } | cat
2585 * In all these cases sending SIGWINCH to the child shell
2586 * did not run the trap. If I add trap "echo V" WINCH;
2587 * _inside_ group (just before echo 1), it works.
2589 * I conclude it means we don't need to pass active traps here.
2590 * exec syscall below resets them to SIG_DFL for us.
2592 *pp++ = (char *) "-c";
2597 /* *pp = NULL; - is already there */
2601 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2602 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2603 execve(bb_busybox_exec_path, argv, pp);
2604 /* Fallback. Useful for init=/bin/hush usage etc */
2605 if (argv[0][0] == '/')
2606 execve(argv[0], argv, pp);
2607 xfunc_error_retval = 127;
2608 bb_error_msg_and_die("can't re-execute the shell");
2610 #endif /* !BB_MMU */
2613 static void setup_heredoc(struct redir_struct *redir)
2615 struct fd_pair pair;
2618 /* the _body_ of heredoc (misleading field name) */
2619 const char *heredoc = redir->rd_filename;
2626 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2627 expanded = expand_pseudo_dquoted(heredoc);
2631 len = strlen(heredoc);
2633 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2635 xmove_fd(pair.rd, redir->rd_fd);
2637 /* Try writing without forking. Newer kernels have
2638 * dynamically growing pipes. Must use non-blocking write! */
2641 written = write(pair.wr, heredoc, len);
2652 ndelay_off(pair.wr);
2654 /* Okay, pipe buffer was not big enough */
2655 /* Note: we must not create a stray child (bastard? :)
2656 * for the unsuspecting parent process. Child creates a grandchild
2657 * and exits before parent execs the process which consumes heredoc
2658 * (that exec happens after we return from this function) */
2664 bb_perror_msg_and_die("vfork");
2667 disable_restore_tty_pgrp_on_exit();
2668 pid = BB_MMU ? fork() : vfork();
2670 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2674 close(redir->rd_fd); /* read side of the pipe */
2676 full_write(pair.wr, heredoc, len); /* may loop or block */
2679 /* Delegate blocking writes to another process */
2680 xmove_fd(pair.wr, STDOUT_FILENO);
2681 re_execute_shell(&to_free, heredoc, NULL, NULL);
2685 #if ENABLE_HUSH_FAST
2687 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2689 enable_restore_tty_pgrp_on_exit();
2695 wait(NULL); /* wait till child has died */
2698 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2699 * and stderr if they are redirected. */
2700 static int setup_redirects(struct command *prog, int squirrel[])
2703 struct redir_struct *redir;
2705 for (redir = prog->redirects; redir; redir = redir->next) {
2706 if (redir->rd_type == REDIRECT_HEREDOC2) {
2707 /* rd_fd<<HERE case */
2708 if (squirrel && redir->rd_fd < 3
2709 && squirrel[redir->rd_fd] < 0
2711 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2713 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2715 debug_printf_parse("set heredoc '%s'\n",
2716 redir->rd_filename);
2717 setup_heredoc(redir);
2721 if (redir->rd_dup == REDIRFD_TO_FILE) {
2722 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2724 if (redir->rd_filename == NULL) {
2725 /* Something went wrong in the parse.
2726 * Pretend it didn't happen */
2727 bb_error_msg("bug in redirect parse");
2730 mode = redir_table[redir->rd_type].mode;
2731 p = expand_string_to_string(redir->rd_filename);
2732 openfd = open_or_warn(p, mode);
2735 /* this could get lost if stderr has been redirected, but
2736 * bash and ash both lose it as well (though zsh doesn't!) */
2737 //what the above comment tries to say?
2741 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2742 openfd = redir->rd_dup;
2745 if (openfd != redir->rd_fd) {
2746 if (squirrel && redir->rd_fd < 3
2747 && squirrel[redir->rd_fd] < 0
2749 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2751 if (openfd == REDIRFD_CLOSE) {
2752 /* "n>-" means "close me" */
2753 close(redir->rd_fd);
2755 xdup2(openfd, redir->rd_fd);
2756 if (redir->rd_dup == REDIRFD_TO_FILE)
2764 static void restore_redirects(int squirrel[])
2767 for (i = 0; i < 3; i++) {
2770 /* We simply die on error */
2777 static void free_pipe_list(struct pipe *head);
2779 /* Return code is the exit status of the pipe */
2780 static void free_pipe(struct pipe *pi)
2783 struct command *command;
2784 struct redir_struct *r, *rnext;
2787 if (pi->stopped_cmds > 0) /* why? */
2789 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2790 for (i = 0; i < pi->num_cmds; i++) {
2791 command = &pi->cmds[i];
2792 debug_printf_clean(" command %d:\n", i);
2793 if (command->argv) {
2794 for (a = 0, p = command->argv; *p; a++, p++) {
2795 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2797 free_strings(command->argv);
2798 command->argv = NULL;
2800 /* not "else if": on syntax error, we may have both! */
2801 if (command->group) {
2802 debug_printf_clean(" begin group (grp_type:%d)\n",
2804 free_pipe_list(command->group);
2805 debug_printf_clean(" end group\n");
2806 command->group = NULL;
2808 /* else is crucial here.
2809 * If group != NULL, child_func is meaningless */
2810 #if ENABLE_HUSH_FUNCTIONS
2811 else if (command->child_func) {
2812 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2813 command->child_func->parent_cmd = NULL;
2817 free(command->group_as_string);
2818 command->group_as_string = NULL;
2820 for (r = command->redirects; r; r = rnext) {
2821 debug_printf_clean(" redirect %d%s",
2822 r->rd_fd, redir_table[r->rd_type].descrip);
2823 /* guard against the case >$FOO, where foo is unset or blank */
2824 if (r->rd_filename) {
2825 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2826 free(r->rd_filename);
2827 r->rd_filename = NULL;
2829 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2833 command->redirects = NULL;
2835 free(pi->cmds); /* children are an array, they get freed all at once */
2843 static void free_pipe_list(struct pipe *head)
2845 struct pipe *pi, *next;
2847 for (pi = head; pi; pi = next) {
2849 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2852 debug_printf_clean("pipe followup code %d\n", pi->followup);
2854 /*pi->next = NULL;*/
2860 static int run_list(struct pipe *pi);
2862 #define parse_stream(pstring, input, end_trigger) \
2863 parse_stream(input, end_trigger)
2865 static struct pipe *parse_stream(char **pstring,
2866 struct in_str *input,
2868 static void parse_and_run_string(const char *s);
2871 static char *find_in_path(const char *arg)
2874 const char *PATH = get_local_var_value("PATH");
2880 const char *end = strchrnul(PATH, ':');
2881 int sz = end - PATH; /* must be int! */
2885 ret = xasprintf("%.*s/%s", sz, PATH, arg);
2887 /* We have xxx::yyyy in $PATH,
2888 * it means "use current dir" */
2891 if (access(ret, F_OK) == 0)
2904 static const struct built_in_command* find_builtin(const char *name)
2906 const struct built_in_command *x;
2907 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2908 if (strcmp(name, x->cmd) != 0)
2910 debug_printf_exec("found builtin '%s'\n", name);
2916 #if ENABLE_HUSH_FUNCTIONS
2917 static const struct function *find_function(const char *name)
2919 const struct function *funcp = G.top_func;
2921 if (strcmp(name, funcp->name) == 0) {
2924 funcp = funcp->next;
2927 debug_printf_exec("found function '%s'\n", name);
2931 /* Note: takes ownership on name ptr */
2932 static struct function *new_function(char *name)
2934 struct function *funcp;
2935 struct function **funcpp = &G.top_func;
2937 while ((funcp = *funcpp) != NULL) {
2938 struct command *cmd;
2940 if (strcmp(funcp->name, name) != 0) {
2941 funcpp = &funcp->next;
2945 cmd = funcp->parent_cmd;
2946 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2948 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2950 /* Note: if !funcp->body, do not free body_as_string!
2951 * This is a special case of "-F name body" function:
2952 * body_as_string was not malloced! */
2954 free_pipe_list(funcp->body);
2956 free(funcp->body_as_string);
2960 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2961 cmd->argv[0] = funcp->name;
2962 cmd->group = funcp->body;
2964 cmd->group_as_string = funcp->body_as_string;
2969 debug_printf_exec("remembering new function '%s'\n", name);
2970 funcp = *funcpp = xzalloc(sizeof(*funcp));
2971 /*funcp->next = NULL;*/
2977 static void unset_func(const char *name)
2979 struct function *funcp;
2980 struct function **funcpp = &G.top_func;
2982 while ((funcp = *funcpp) != NULL) {
2983 if (strcmp(funcp->name, name) == 0) {
2984 *funcpp = funcp->next;
2985 /* funcp is unlinked now, deleting it.
2986 * Note: if !funcp->body, the function was created by
2987 * "-F name body", do not free ->body_as_string
2988 * and ->name as they were not malloced. */
2990 free_pipe_list(funcp->body);
2993 free(funcp->body_as_string);
2999 funcpp = &funcp->next;
3004 #define exec_function(nommu_save, funcp, argv) \
3005 exec_function(funcp, argv)
3007 static void exec_function(nommu_save_t *nommu_save,
3008 const struct function *funcp,
3009 char **argv) NORETURN;
3010 static void exec_function(nommu_save_t *nommu_save,
3011 const struct function *funcp,
3017 argv[0] = G.global_argv[0];
3018 G.global_argv = argv;
3022 /* On MMU, funcp->body is always non-NULL */
3023 n = run_list(funcp->body);
3027 re_execute_shell(&nommu_save->argv_from_re_execing,
3028 funcp->body_as_string,
3034 static int run_function(const struct function *funcp, char **argv)
3040 save_and_replace_G_args(&sv, argv);
3041 /* "we are in function, ok to use return" */
3042 sv_flg = G.flag_return_in_progress;
3043 G.flag_return_in_progress = -1;
3045 /* On MMU, funcp->body is always non-NULL */
3048 /* Function defined by -F */
3049 parse_and_run_string(funcp->body_as_string);
3050 rc = G.last_exitcode;
3054 rc = run_list(funcp->body);
3057 G.flag_return_in_progress = sv_flg;
3058 restore_G_args(&sv, argv);
3062 #endif /* ENABLE_HUSH_FUNCTIONS */
3066 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3067 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3068 #define pseudo_exec(nommu_save, command, argv_expanded) \
3069 pseudo_exec(command, argv_expanded)
3072 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3074 * Don't exit() here. If you don't exec, use _exit instead.
3075 * The at_exit handlers apparently confuse the calling process,
3076 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3077 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3078 char **argv, int assignment_cnt,
3079 char **argv_expanded) NORETURN;
3080 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3081 char **argv, int assignment_cnt,
3082 char **argv_expanded)
3086 /* Case when we are here: ... | var=val | ... */
3087 if (!argv[assignment_cnt])
3088 _exit(EXIT_SUCCESS);
3090 new_env = expand_assignments(argv, assignment_cnt);
3092 set_vars_and_save_old(new_env);
3093 free(new_env); /* optional */
3094 /* we can also destroy set_vars_and_save_old's return value,
3097 nommu_save->new_env = new_env;
3098 nommu_save->old_vars = set_vars_and_save_old(new_env);
3100 if (argv_expanded) {
3101 argv = argv_expanded;
3103 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3105 nommu_save->argv = argv;
3109 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3110 if (strchr(argv[0], '/') != NULL)
3114 /* On NOMMU, we must never block!
3115 * Example: { sleep 99999 | read line } & echo Ok
3116 * read builtin will block on read syscall, leaving parent blocked
3117 * in vfork. Therefore we can't do this:
3120 /* Check if the command matches any of the builtins.
3121 * Depending on context, this might be redundant. But it's
3122 * easier to waste a few CPU cycles than it is to figure out
3123 * if this is one of those cases.
3127 const struct built_in_command *x = find_builtin(argv[0]);
3129 rcode = x->function(argv);
3135 #if ENABLE_HUSH_FUNCTIONS
3136 /* Check if the command matches any functions */
3138 const struct function *funcp = find_function(argv[0]);
3140 exec_function(nommu_save, funcp, argv);
3145 #if ENABLE_FEATURE_SH_STANDALONE
3146 /* Check if the command matches any busybox applets */
3148 int a = find_applet_by_name(argv[0]);
3150 # if BB_MMU /* see above why on NOMMU it is not allowed */
3151 if (APPLET_IS_NOEXEC(a)) {
3152 debug_printf_exec("running applet '%s'\n", argv[0]);
3153 run_applet_no_and_exit(a, argv);
3156 /* Re-exec ourselves */
3157 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3158 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3159 execv(bb_busybox_exec_path, argv);
3160 /* If they called chroot or otherwise made the binary no longer
3161 * executable, fall through */
3166 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3169 debug_printf_exec("execing '%s'\n", argv[0]);
3170 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3171 execvp(argv[0], argv);
3172 bb_perror_msg("can't execute '%s'", argv[0]);
3173 _exit(EXIT_FAILURE);
3176 /* Called after [v]fork() in run_pipe
3178 static void pseudo_exec(nommu_save_t *nommu_save,
3179 struct command *command,
3180 char **argv_expanded) NORETURN;
3181 static void pseudo_exec(nommu_save_t *nommu_save,
3182 struct command *command,
3183 char **argv_expanded)
3185 if (command->argv) {
3186 pseudo_exec_argv(nommu_save, command->argv,
3187 command->assignment_cnt, argv_expanded);
3190 if (command->group) {
3191 /* Cases when we are here:
3194 * ... | ( list ) | ...
3195 * ... | { list } | ...
3199 debug_printf_exec("pseudo_exec: run_list\n");
3200 reset_traps_to_defaults();
3201 rcode = run_list(command->group);
3202 /* OK to leak memory by not calling free_pipe_list,
3203 * since this process is about to exit */
3206 re_execute_shell(&nommu_save->argv_from_re_execing,
3207 command->group_as_string,
3213 /* Case when we are here: ... | >file */
3214 debug_printf_exec("pseudo_exec'ed null command\n");
3215 _exit(EXIT_SUCCESS);
3219 static const char *get_cmdtext(struct pipe *pi)
3225 /* This is subtle. ->cmdtext is created only on first backgrounding.
3226 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3227 * On subsequent bg argv is trashed, but we won't use it */
3230 argv = pi->cmds[0].argv;
3231 if (!argv || !argv[0]) {
3232 pi->cmdtext = xzalloc(1);
3238 len += strlen(*argv) + 1;
3242 argv = pi->cmds[0].argv;
3244 len = strlen(*argv);
3245 memcpy(p, *argv, len);
3253 static void insert_bg_job(struct pipe *pi)
3255 struct pipe *job, **jobp;
3258 /* Linear search for the ID of the job to use */
3260 for (job = G.job_list; job; job = job->next)
3261 if (job->jobid >= pi->jobid)
3262 pi->jobid = job->jobid + 1;
3264 /* Add job to the list of running jobs */
3266 while ((job = *jobp) != NULL)
3268 job = *jobp = xmalloc(sizeof(*job));
3270 *job = *pi; /* physical copy */
3272 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3273 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3274 for (i = 0; i < pi->num_cmds; i++) {
3275 job->cmds[i].pid = pi->cmds[i].pid;
3276 /* all other fields are not used and stay zero */
3278 job->cmdtext = xstrdup(get_cmdtext(pi));
3280 if (G_interactive_fd)
3281 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3282 /* Last command's pid goes to $! */
3283 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3284 G.last_jobid = job->jobid;
3287 static void remove_bg_job(struct pipe *pi)
3289 struct pipe *prev_pipe;
3291 if (pi == G.job_list) {
3292 G.job_list = pi->next;
3294 prev_pipe = G.job_list;
3295 while (prev_pipe->next != pi)
3296 prev_pipe = prev_pipe->next;
3297 prev_pipe->next = pi->next;
3300 G.last_jobid = G.job_list->jobid;
3305 /* Remove a backgrounded job */
3306 static void delete_finished_bg_job(struct pipe *pi)
3309 pi->stopped_cmds = 0;
3315 /* Check to see if any processes have exited -- if they
3316 * have, figure out why and see if a job has completed */
3317 static int checkjobs(struct pipe* fg_pipe)
3327 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3329 attributes = WUNTRACED;
3330 if (fg_pipe == NULL)
3331 attributes |= WNOHANG;
3334 #if ENABLE_HUSH_FAST
3335 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3336 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3337 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3338 /* There was neither fork nor SIGCHLD since last waitpid */
3339 /* Avoid doing waitpid syscall if possible */
3340 if (!G.we_have_children) {
3344 if (fg_pipe == NULL) { /* is WNOHANG set? */
3345 /* We have children, but they did not exit
3346 * or stop yet (we saw no SIGCHLD) */
3349 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3353 /* Do we do this right?
3354 * bash-3.00# sleep 20 | false
3356 * [3]+ Stopped sleep 20 | false
3357 * bash-3.00# echo $?
3358 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3359 * [hush 1.14.0: yes we do it right]
3366 #if ENABLE_HUSH_FAST
3367 i = G.count_SIGCHLD;
3369 childpid = waitpid(-1, &status, attributes);
3370 if (childpid <= 0) {
3371 if (childpid && errno != ECHILD)
3372 bb_perror_msg("waitpid");
3373 #if ENABLE_HUSH_FAST
3374 else { /* Until next SIGCHLD, waitpid's are useless */
3375 G.we_have_children = (childpid == 0);
3376 G.handled_SIGCHLD = i;
3377 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3382 dead = WIFEXITED(status) || WIFSIGNALED(status);
3385 if (WIFSTOPPED(status))
3386 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3387 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3388 if (WIFSIGNALED(status))
3389 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3390 childpid, WTERMSIG(status), WEXITSTATUS(status));
3391 if (WIFEXITED(status))
3392 debug_printf_jobs("pid %d exited, exitcode %d\n",
3393 childpid, WEXITSTATUS(status));
3395 /* Were we asked to wait for fg pipe? */
3397 for (i = 0; i < fg_pipe->num_cmds; i++) {
3398 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3399 if (fg_pipe->cmds[i].pid != childpid)
3402 fg_pipe->cmds[i].pid = 0;
3403 fg_pipe->alive_cmds--;
3404 if (i == fg_pipe->num_cmds - 1) {
3405 /* last process gives overall exitstatus */
3406 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3407 rcode = WEXITSTATUS(status);
3408 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3409 /* bash prints killing signal's name for *last*
3410 * process in pipe (prints just newline for SIGINT).
3411 * Mimic this. Example: "sleep 5" + ^\
3413 if (WIFSIGNALED(status)) {
3414 int sig = WTERMSIG(status);
3415 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3419 fg_pipe->cmds[i].is_stopped = 1;
3420 fg_pipe->stopped_cmds++;
3422 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3423 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3424 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3425 /* All processes in fg pipe have exited or stopped */
3426 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3427 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3428 * and "killall -STOP cat" */
3429 if (G_interactive_fd) {
3431 if (fg_pipe->alive_cmds)
3432 insert_bg_job(fg_pipe);
3437 /* There are still running processes in the fg pipe */
3438 goto wait_more; /* do waitpid again */
3440 /* it wasnt fg_pipe, look for process in bg pipes */
3444 /* We asked to wait for bg or orphaned children */
3445 /* No need to remember exitcode in this case */
3446 for (pi = G.job_list; pi; pi = pi->next) {
3447 for (i = 0; i < pi->num_cmds; i++) {
3448 if (pi->cmds[i].pid == childpid)
3449 goto found_pi_and_prognum;
3452 /* Happens when shell is used as init process (init=/bin/sh) */
3453 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3454 continue; /* do waitpid again */
3456 found_pi_and_prognum:
3459 pi->cmds[i].pid = 0;
3461 if (!pi->alive_cmds) {
3462 if (G_interactive_fd)
3463 printf(JOB_STATUS_FORMAT, pi->jobid,
3464 "Done", pi->cmdtext);
3465 delete_finished_bg_job(pi);
3469 pi->cmds[i].is_stopped = 1;
3473 } /* while (waitpid succeeds)... */
3479 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3482 int rcode = checkjobs(fg_pipe);
3483 if (G_saved_tty_pgrp) {
3484 /* Job finished, move the shell to the foreground */
3485 p = getpgrp(); /* our process group id */
3486 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3487 tcsetpgrp(G_interactive_fd, p);
3493 /* Start all the jobs, but don't wait for anything to finish.
3496 * Return code is normally -1, when the caller has to wait for children
3497 * to finish to determine the exit status of the pipe. If the pipe
3498 * is a simple builtin command, however, the action is done by the
3499 * time run_pipe returns, and the exit code is provided as the
3502 * Returns -1 only if started some children. IOW: we have to
3503 * mask out retvals of builtins etc with 0xff!
3505 * The only case when we do not need to [v]fork is when the pipe
3506 * is single, non-backgrounded, non-subshell command. Examples:
3507 * cmd ; ... { list } ; ...
3508 * cmd && ... { list } && ...
3509 * cmd || ... { list } || ...
3510 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3511 * or (if SH_STANDALONE) an applet, and we can run the { list }
3512 * with run_list. If it isn't one of these, we fork and exec cmd.
3514 * Cases when we must fork:
3515 * non-single: cmd | cmd
3516 * backgrounded: cmd & { list } &
3517 * subshell: ( list ) [&]
3519 static int run_pipe(struct pipe *pi)
3521 static const char *const null_ptr = NULL;
3524 struct command *command;
3525 char **argv_expanded;
3528 /* it is not always needed, but we aim to smaller code */
3529 int squirrel[] = { -1, -1, -1 };
3532 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3535 IF_HUSH_JOB(pi->pgrp = -1;)
3536 pi->stopped_cmds = 0;
3537 command = &(pi->cmds[0]);
3538 argv_expanded = NULL;
3540 if (pi->num_cmds != 1
3541 || pi->followup == PIPE_BG
3542 || command->grp_type == GRP_SUBSHELL
3549 debug_printf_exec(": group:%p argv:'%s'\n",
3550 command->group, command->argv ? command->argv[0] : "NONE");
3552 if (command->group) {
3553 #if ENABLE_HUSH_FUNCTIONS
3554 if (command->grp_type == GRP_FUNCTION) {
3555 /* "executing" func () { list } */
3556 struct function *funcp;
3558 funcp = new_function(command->argv[0]);
3559 /* funcp->name is already set to argv[0] */
3560 funcp->body = command->group;
3562 funcp->body_as_string = command->group_as_string;
3563 command->group_as_string = NULL;
3565 command->group = NULL;
3566 command->argv[0] = NULL;
3567 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3568 funcp->parent_cmd = command;
3569 command->child_func = funcp;
3571 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3573 return EXIT_SUCCESS;
3577 debug_printf("non-subshell group\n");
3578 rcode = 1; /* exitcode if redir failed */
3579 if (setup_redirects(command, squirrel) == 0) {
3580 debug_printf_exec(": run_list\n");
3581 rcode = run_list(command->group) & 0xff;
3583 restore_redirects(squirrel);
3584 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3586 debug_printf_exec("run_pipe: return %d\n", rcode);
3590 argv = command->argv ? command->argv : (char **) &null_ptr;
3592 const struct built_in_command *x;
3593 #if ENABLE_HUSH_FUNCTIONS
3594 const struct function *funcp;
3598 char **new_env = NULL;
3599 struct variable *old_vars = NULL;
3601 if (argv[command->assignment_cnt] == NULL) {
3602 /* Assignments, but no command */
3603 /* Ensure redirects take effect. Try "a=t >file" */
3604 rcode = setup_redirects(command, squirrel);
3605 restore_redirects(squirrel);
3606 /* Set shell variables */
3608 p = expand_string_to_string(*argv);
3609 debug_printf_exec("set shell var:'%s'->'%s'\n",
3611 set_local_var(p, 0, 0);
3614 /* Do we need to flag set_local_var() errors?
3615 * "assignment to readonly var" and "putenv error"
3617 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3619 debug_printf_exec("run_pipe: return %d\n", rcode);
3623 /* Expand the rest into (possibly) many strings each */
3624 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3626 x = find_builtin(argv_expanded[0]);
3627 #if ENABLE_HUSH_FUNCTIONS
3630 funcp = find_function(argv_expanded[0]);
3634 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3635 debug_printf("exec with redirects only\n");
3636 rcode = setup_redirects(command, NULL);
3637 goto clean_up_and_ret1;
3640 /* setup_redirects acts on file descriptors, not FILEs.
3641 * This is perfect for work that comes after exec().
3642 * Is it really safe for inline use? Experimentally,
3643 * things seem to work. */
3644 rcode = setup_redirects(command, squirrel);
3646 new_env = expand_assignments(argv, command->assignment_cnt);
3647 old_vars = set_vars_and_save_old(new_env);
3649 debug_printf_exec(": builtin '%s' '%s'...\n",
3650 x->cmd, argv_expanded[1]);
3651 rcode = x->function(argv_expanded) & 0xff;
3654 #if ENABLE_HUSH_FUNCTIONS
3656 debug_printf_exec(": function '%s' '%s'...\n",
3657 funcp->name, argv_expanded[1]);
3658 rcode = run_function(funcp, argv_expanded) & 0xff;
3662 #if ENABLE_FEATURE_SH_STANDALONE
3665 restore_redirects(squirrel);
3666 unset_vars(new_env);
3669 free(argv_expanded);
3670 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3672 debug_printf_exec("run_pipe return %d\n", rcode);
3676 #if ENABLE_FEATURE_SH_STANDALONE
3677 i = find_applet_by_name(argv_expanded[0]);
3678 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3679 rcode = setup_redirects(command, squirrel);
3681 new_env = expand_assignments(argv, command->assignment_cnt);
3682 old_vars = set_vars_and_save_old(new_env);
3683 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3684 argv_expanded[0], argv_expanded[1]);
3685 rcode = run_nofork_applet(i, argv_expanded);
3687 goto clean_up_and_ret;
3690 /* It is neither builtin nor applet. We must fork. */
3694 /* NB: argv_expanded may already be created, and that
3695 * might include `cmd` runs! Do not rerun it! We *must*
3696 * use argv_expanded if it's non-NULL */
3698 /* Going to fork a child per each pipe member */
3702 for (i = 0; i < pi->num_cmds; i++) {
3703 struct fd_pair pipefds;
3705 volatile nommu_save_t nommu_save;
3706 nommu_save.new_env = NULL;
3707 nommu_save.old_vars = NULL;
3708 nommu_save.argv = NULL;
3709 nommu_save.argv_from_re_execing = NULL;
3711 command = &(pi->cmds[i]);
3712 if (command->argv) {
3713 debug_printf_exec(": pipe member '%s' '%s'...\n",
3714 command->argv[0], command->argv[1]);
3716 debug_printf_exec(": pipe member with no argv\n");
3719 /* pipes are inserted between pairs of commands */
3722 if ((i + 1) < pi->num_cmds)
3723 xpiped_pair(pipefds);
3725 command->pid = BB_MMU ? fork() : vfork();
3726 if (!command->pid) { /* child */
3728 disable_restore_tty_pgrp_on_exit();
3730 /* Every child adds itself to new process group
3731 * with pgid == pid_of_first_child_in_pipe */
3732 if (G.run_list_level == 1 && G_interactive_fd) {
3735 if (pgrp < 0) /* true for 1st process only */
3737 if (setpgid(0, pgrp) == 0
3738 && pi->followup != PIPE_BG
3739 && G_saved_tty_pgrp /* we have ctty */
3741 /* We do it in *every* child, not just first,
3743 tcsetpgrp(G_interactive_fd, pgrp);
3747 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
3748 /* 1st cmd in backgrounded pipe
3749 * should have its stdin /dev/null'ed */
3751 if (open(bb_dev_null, O_RDONLY))
3752 xopen("/", O_RDONLY);
3754 xmove_fd(nextin, 0);
3756 xmove_fd(pipefds.wr, 1);
3759 /* Like bash, explicit redirects override pipes,
3760 * and the pipe fd is available for dup'ing. */
3761 if (setup_redirects(command, NULL))
3764 /* Restore default handlers just prior to exec */
3765 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3767 /* Stores to nommu_save list of env vars putenv'ed
3768 * (NOMMU, on MMU we don't need that) */
3769 /* cast away volatility... */
3770 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3771 /* pseudo_exec() does not return */
3774 /* parent or error */
3775 #if ENABLE_HUSH_FAST
3777 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3779 enable_restore_tty_pgrp_on_exit();
3781 /* Clean up after vforked child */
3782 free(nommu_save.argv);
3783 free(nommu_save.argv_from_re_execing);
3784 unset_vars(nommu_save.new_env);
3785 add_vars(nommu_save.old_vars);
3787 free(argv_expanded);
3788 argv_expanded = NULL;
3789 if (command->pid < 0) { /* [v]fork failed */
3790 /* Clearly indicate, was it fork or vfork */
3791 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3795 /* Second and next children need to know pid of first one */
3797 pi->pgrp = command->pid;
3803 if ((i + 1) < pi->num_cmds)
3805 /* Pass read (output) pipe end to next iteration */
3806 nextin = pipefds.rd;
3809 if (!pi->alive_cmds) {
3811 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3816 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3820 #ifndef debug_print_tree
3821 static void debug_print_tree(struct pipe *pi, int lvl)
3823 static const char *const PIPE[] = {
3829 static const char *RES[] = {
3830 [RES_NONE ] = "NONE" ,
3833 [RES_THEN ] = "THEN" ,
3834 [RES_ELIF ] = "ELIF" ,
3835 [RES_ELSE ] = "ELSE" ,
3838 #if ENABLE_HUSH_LOOPS
3839 [RES_FOR ] = "FOR" ,
3840 [RES_WHILE] = "WHILE",
3841 [RES_UNTIL] = "UNTIL",
3843 [RES_DONE ] = "DONE" ,
3845 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3848 #if ENABLE_HUSH_CASE
3849 [RES_CASE ] = "CASE" ,
3850 [RES_CASE_IN ] = "CASE_IN" ,
3851 [RES_MATCH] = "MATCH",
3852 [RES_CASE_BODY] = "CASE_BODY",
3853 [RES_ESAC ] = "ESAC" ,
3855 [RES_XXXX ] = "XXXX" ,
3856 [RES_SNTX ] = "SNTX" ,
3858 static const char *const GRPTYPE[] = {
3861 #if ENABLE_HUSH_FUNCTIONS
3870 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3871 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3873 while (prn < pi->num_cmds) {
3874 struct command *command = &pi->cmds[prn];
3875 char **argv = command->argv;
3877 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3879 command->assignment_cnt);
3880 if (command->group) {
3881 fprintf(stderr, " group %s: (argv=%p)\n",
3882 GRPTYPE[command->grp_type],
3884 debug_print_tree(command->group, lvl+1);
3888 if (argv) while (*argv) {
3889 fprintf(stderr, " '%s'", *argv);
3892 fprintf(stderr, "\n");
3901 /* NB: called by pseudo_exec, and therefore must not modify any
3902 * global data until exec/_exit (we can be a child after vfork!) */
3903 static int run_list(struct pipe *pi)
3905 #if ENABLE_HUSH_CASE
3906 char *case_word = NULL;
3908 #if ENABLE_HUSH_LOOPS
3909 struct pipe *loop_top = NULL;
3910 char **for_lcur = NULL;
3911 char **for_list = NULL;
3913 smallint last_followup;
3915 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3916 smalluint cond_code = 0;
3918 enum { cond_code = 0 };
3921 smallint rword; /* enum reserved_style */
3922 smallint last_rword; /* ditto */
3925 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3928 #if ENABLE_HUSH_LOOPS
3929 /* Check syntax for "for" */
3930 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3931 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3933 /* current word is FOR or IN (BOLD in comments below) */
3934 if (cpipe->next == NULL) {
3935 syntax_error("malformed for");
3937 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3940 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3941 if (cpipe->next->res_word == RES_DO)
3943 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3944 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3945 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3947 syntax_error("malformed for");
3949 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3955 /* Past this point, all code paths should jump to ret: label
3956 * in order to return, no direct "return" statements please.
3957 * This helps to ensure that no memory is leaked. */
3965 last_rword = RES_XXXX;
3967 last_followup = PIPE_SEQ;
3968 rcode = G.last_exitcode;
3970 /* Go through list of pipes, (maybe) executing them. */
3971 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3975 IF_HAS_KEYWORDS(rword = pi->res_word;)
3976 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3977 rword, cond_code, last_rword);
3978 #if ENABLE_HUSH_LOOPS
3979 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3980 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3982 /* start of a loop: remember where loop starts */
3987 /* Still in the same "if...", "then..." or "do..." branch? */
3988 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3989 if ((rcode == 0 && last_followup == PIPE_OR)
3990 || (rcode != 0 && last_followup == PIPE_AND)
3992 /* It is "<true> || CMD" or "<false> && CMD"
3993 * and we should not execute CMD */
3994 debug_printf_exec("skipped cmd because of || or &&\n");
3995 last_followup = pi->followup;
3999 last_followup = pi->followup;
4000 IF_HAS_KEYWORDS(last_rword = rword;)
4003 if (rword == RES_THEN) {
4004 /* if false; then ... fi has exitcode 0! */
4005 G.last_exitcode = rcode = EXIT_SUCCESS;
4006 /* "if <false> THEN cmd": skip cmd */
4010 if (rword == RES_ELSE || rword == RES_ELIF) {
4011 /* "if <true> then ... ELSE/ELIF cmd":
4012 * skip cmd and all following ones */
4017 #if ENABLE_HUSH_LOOPS
4018 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4020 /* first loop through for */
4022 static const char encoded_dollar_at[] ALIGN1 = {
4023 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4024 }; /* encoded representation of "$@" */
4025 static const char *const encoded_dollar_at_argv[] = {
4026 encoded_dollar_at, NULL
4027 }; /* argv list with one element: "$@" */
4030 vals = (char**)encoded_dollar_at_argv;
4031 if (pi->next->res_word == RES_IN) {
4032 /* if no variable values after "in" we skip "for" */
4033 if (!pi->next->cmds[0].argv) {
4034 G.last_exitcode = rcode = EXIT_SUCCESS;
4035 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4038 vals = pi->next->cmds[0].argv;
4039 } /* else: "for var; do..." -> assume "$@" list */
4040 /* create list of variable values */
4041 debug_print_strings("for_list made from", vals);
4042 for_list = expand_strvec_to_strvec(vals);
4043 for_lcur = for_list;
4044 debug_print_strings("for_list", for_list);
4047 /* "for" loop is over, clean up */
4053 /* Insert next value from for_lcur */
4054 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4055 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), 0, 0);
4058 if (rword == RES_IN) {
4059 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4061 if (rword == RES_DONE) {
4062 continue; /* "done" has no cmds too */
4065 #if ENABLE_HUSH_CASE
4066 if (rword == RES_CASE) {
4067 case_word = expand_strvec_to_string(pi->cmds->argv);
4070 if (rword == RES_MATCH) {
4073 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4075 /* all prev words didn't match, does this one match? */
4076 argv = pi->cmds->argv;
4078 char *pattern = expand_string_to_string(*argv);
4079 /* TODO: which FNM_xxx flags to use? */
4080 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4082 if (cond_code == 0) { /* match! we will execute this branch */
4083 free(case_word); /* make future "word)" stop */
4091 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4093 continue; /* not matched yet, skip this pipe */
4096 /* Just pressing <enter> in shell should check for jobs.
4097 * OTOH, in non-interactive shell this is useless
4098 * and only leads to extra job checks */
4099 if (pi->num_cmds == 0) {
4100 if (G_interactive_fd)
4101 goto check_jobs_and_continue;
4105 /* After analyzing all keywords and conditions, we decided
4106 * to execute this pipe. NB: have to do checkjobs(NULL)
4107 * after run_pipe to collect any background children,
4108 * even if list execution is to be stopped. */
4109 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4112 #if ENABLE_HUSH_LOOPS
4113 G.flag_break_continue = 0;
4115 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4117 /* We ran a builtin, function, or group.
4118 * rcode is already known
4119 * and we don't need to wait for anything. */
4120 G.last_exitcode = rcode;
4121 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4122 check_and_run_traps(0);
4123 #if ENABLE_HUSH_LOOPS
4124 /* Was it "break" or "continue"? */
4125 if (G.flag_break_continue) {
4126 smallint fbc = G.flag_break_continue;
4127 /* We might fall into outer *loop*,
4128 * don't want to break it too */
4130 G.depth_break_continue--;
4131 if (G.depth_break_continue == 0)
4132 G.flag_break_continue = 0;
4133 /* else: e.g. "continue 2" should *break* once, *then* continue */
4134 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4135 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4136 goto check_jobs_and_break;
4137 /* "continue": simulate end of loop */
4142 #if ENABLE_HUSH_FUNCTIONS
4143 if (G.flag_return_in_progress == 1) {
4144 /* same as "goto check_jobs_and_break" */
4149 } else if (pi->followup == PIPE_BG) {
4150 /* What does bash do with attempts to background builtins? */
4151 /* even bash 3.2 doesn't do that well with nested bg:
4152 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4153 * I'm NOT treating inner &'s as jobs */
4154 check_and_run_traps(0);
4156 if (G.run_list_level == 1)
4159 G.last_exitcode = rcode = EXIT_SUCCESS;
4160 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4163 if (G.run_list_level == 1 && G_interactive_fd) {
4164 /* Waits for completion, then fg's main shell */
4165 rcode = checkjobs_and_fg_shell(pi);
4166 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4167 check_and_run_traps(0);
4170 { /* This one just waits for completion */
4171 rcode = checkjobs(pi);
4172 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4173 check_and_run_traps(0);
4175 G.last_exitcode = rcode;
4179 /* Analyze how result affects subsequent commands */
4181 if (rword == RES_IF || rword == RES_ELIF)
4184 #if ENABLE_HUSH_LOOPS
4185 /* Beware of "while false; true; do ..."! */
4186 if (pi->next && pi->next->res_word == RES_DO) {
4187 if (rword == RES_WHILE) {
4189 /* "while false; do...done" - exitcode 0 */
4190 G.last_exitcode = rcode = EXIT_SUCCESS;
4191 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4192 goto check_jobs_and_break;
4195 if (rword == RES_UNTIL) {
4197 debug_printf_exec(": until expr is true: breaking\n");
4198 check_jobs_and_break:
4206 check_jobs_and_continue:
4213 #if ENABLE_HUSH_LOOPS
4218 #if ENABLE_HUSH_CASE
4222 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4226 /* Select which version we will use */
4227 static int run_and_free_list(struct pipe *pi)
4230 debug_printf_exec("run_and_free_list entered\n");
4232 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4233 rcode = run_list(pi);
4235 /* free_pipe_list has the side effect of clearing memory.
4236 * In the long run that function can be merged with run_list,
4237 * but doing that now would hobble the debugging effort. */
4239 debug_printf_exec("run_and_free_list return %d\n", rcode);
4244 static struct pipe *new_pipe(void)
4247 pi = xzalloc(sizeof(struct pipe));
4248 /*pi->followup = 0; - deliberately invalid value */
4249 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4253 /* Command (member of a pipe) is complete, or we start a new pipe
4254 * if ctx->command is NULL.
4255 * No errors possible here.
4257 static int done_command(struct parse_context *ctx)
4259 /* The command is really already in the pipe structure, so
4260 * advance the pipe counter and make a new, null command. */
4261 struct pipe *pi = ctx->pipe;
4262 struct command *command = ctx->command;
4265 if (IS_NULL_CMD(command)) {
4266 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4270 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4271 //debug_print_tree(ctx->list_head, 20);
4273 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4276 /* Only real trickiness here is that the uncommitted
4277 * command structure is not counted in pi->num_cmds. */
4278 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4279 ctx->command = command = &pi->cmds[pi->num_cmds];
4281 memset(command, 0, sizeof(*command));
4282 return pi->num_cmds; /* used only for 0/nonzero check */
4285 static void done_pipe(struct parse_context *ctx, pipe_style type)
4289 debug_printf_parse("done_pipe entered, followup %d\n", type);
4290 /* Close previous command */
4291 not_null = done_command(ctx);
4292 ctx->pipe->followup = type;
4294 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4295 ctx->ctx_inverted = 0;
4296 ctx->pipe->res_word = ctx->ctx_res_w;
4299 /* Without this check, even just <enter> on command line generates
4300 * tree of three NOPs (!). Which is harmless but annoying.
4301 * IOW: it is safe to do it unconditionally. */
4304 || ctx->ctx_res_w == RES_FI
4306 #if ENABLE_HUSH_LOOPS
4307 || ctx->ctx_res_w == RES_DONE
4308 || ctx->ctx_res_w == RES_FOR
4309 || ctx->ctx_res_w == RES_IN
4311 #if ENABLE_HUSH_CASE
4312 || ctx->ctx_res_w == RES_ESAC
4316 debug_printf_parse("done_pipe: adding new pipe: "
4317 "not_null:%d ctx->ctx_res_w:%d\n",
4318 not_null, ctx->ctx_res_w);
4320 ctx->pipe->next = new_p;
4322 /* RES_THEN, RES_DO etc are "sticky" -
4323 * they remain set for pipes inside if/while.
4324 * This is used to control execution.
4325 * RES_FOR and RES_IN are NOT sticky (needed to support
4326 * cases where variable or value happens to match a keyword):
4328 #if ENABLE_HUSH_LOOPS
4329 if (ctx->ctx_res_w == RES_FOR
4330 || ctx->ctx_res_w == RES_IN)
4331 ctx->ctx_res_w = RES_NONE;
4333 #if ENABLE_HUSH_CASE
4334 if (ctx->ctx_res_w == RES_MATCH)
4335 ctx->ctx_res_w = RES_CASE_BODY;
4336 if (ctx->ctx_res_w == RES_CASE)
4337 ctx->ctx_res_w = RES_CASE_IN;
4339 ctx->command = NULL; /* trick done_command below */
4340 /* Create the memory for command, roughly:
4341 * ctx->pipe->cmds = new struct command;
4342 * ctx->command = &ctx->pipe->cmds[0];
4345 //debug_print_tree(ctx->list_head, 10);
4347 debug_printf_parse("done_pipe return\n");
4350 static void initialize_context(struct parse_context *ctx)
4352 memset(ctx, 0, sizeof(*ctx));
4353 ctx->pipe = ctx->list_head = new_pipe();
4354 /* Create the memory for command, roughly:
4355 * ctx->pipe->cmds = new struct command;
4356 * ctx->command = &ctx->pipe->cmds[0];
4361 /* If a reserved word is found and processed, parse context is modified
4362 * and 1 is returned.
4365 struct reserved_combo {
4368 unsigned char assignment_flag;
4372 FLAG_END = (1 << RES_NONE ),
4374 FLAG_IF = (1 << RES_IF ),
4375 FLAG_THEN = (1 << RES_THEN ),
4376 FLAG_ELIF = (1 << RES_ELIF ),
4377 FLAG_ELSE = (1 << RES_ELSE ),
4378 FLAG_FI = (1 << RES_FI ),
4380 #if ENABLE_HUSH_LOOPS
4381 FLAG_FOR = (1 << RES_FOR ),
4382 FLAG_WHILE = (1 << RES_WHILE),
4383 FLAG_UNTIL = (1 << RES_UNTIL),
4384 FLAG_DO = (1 << RES_DO ),
4385 FLAG_DONE = (1 << RES_DONE ),
4386 FLAG_IN = (1 << RES_IN ),
4388 #if ENABLE_HUSH_CASE
4389 FLAG_MATCH = (1 << RES_MATCH),
4390 FLAG_ESAC = (1 << RES_ESAC ),
4392 FLAG_START = (1 << RES_XXXX ),
4395 static const struct reserved_combo* match_reserved_word(o_string *word)
4397 /* Mostly a list of accepted follow-up reserved words.
4398 * FLAG_END means we are done with the sequence, and are ready
4399 * to turn the compound list into a command.
4400 * FLAG_START means the word must start a new compound list.
4402 static const struct reserved_combo reserved_list[] = {
4404 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4405 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4406 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4407 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4408 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4409 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4411 #if ENABLE_HUSH_LOOPS
4412 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4413 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4414 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4415 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4416 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4417 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4419 #if ENABLE_HUSH_CASE
4420 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4421 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4424 const struct reserved_combo *r;
4426 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4427 if (strcmp(word->data, r->literal) == 0)
4432 /* Return 0: not a keyword, 1: keyword
4434 static int reserved_word(o_string *word, struct parse_context *ctx)
4436 #if ENABLE_HUSH_CASE
4437 static const struct reserved_combo reserved_match = {
4438 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4441 const struct reserved_combo *r;
4445 r = match_reserved_word(word);
4449 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4450 #if ENABLE_HUSH_CASE
4451 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
4452 /* "case word IN ..." - IN part starts first MATCH part */
4453 r = &reserved_match;
4456 if (r->flag == 0) { /* '!' */
4457 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4458 syntax_error("! ! command");
4459 ctx->ctx_res_w = RES_SNTX;
4461 ctx->ctx_inverted = 1;
4464 if (r->flag & FLAG_START) {
4465 struct parse_context *old;
4467 old = xmalloc(sizeof(*old));
4468 debug_printf_parse("push stack %p\n", old);
4469 *old = *ctx; /* physical copy */
4470 initialize_context(ctx);
4472 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4473 syntax_error_at(word->data);
4474 ctx->ctx_res_w = RES_SNTX;
4477 /* "{...} fi" is ok. "{...} if" is not
4479 * if { echo foo; } then { echo bar; } fi */
4480 if (ctx->command->group)
4481 done_pipe(ctx, PIPE_SEQ);
4484 ctx->ctx_res_w = r->res;
4485 ctx->old_flag = r->flag;
4486 word->o_assignment = r->assignment_flag;
4488 if (ctx->old_flag & FLAG_END) {
4489 struct parse_context *old;
4491 done_pipe(ctx, PIPE_SEQ);
4492 debug_printf_parse("pop stack %p\n", ctx->stack);
4494 old->command->group = ctx->list_head;
4495 old->command->grp_type = GRP_NORMAL;
4497 o_addstr(&old->as_string, ctx->as_string.data);
4498 o_free_unsafe(&ctx->as_string);
4499 old->command->group_as_string = xstrdup(old->as_string.data);
4500 debug_printf_parse("pop, remembering as:'%s'\n",
4501 old->command->group_as_string);
4503 *ctx = *old; /* physical copy */
4510 /* Word is complete, look at it and update parsing context.
4511 * Normal return is 0. Syntax errors return 1.
4512 * Note: on return, word is reset, but not o_free'd!
4514 static int done_word(o_string *word, struct parse_context *ctx)
4516 struct command *command = ctx->command;
4518 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4519 if (word->length == 0 && word->o_quoted == 0) {
4520 debug_printf_parse("done_word return 0: true null, ignored\n");
4524 if (ctx->pending_redirect) {
4525 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4526 * only if run as "bash", not "sh" */
4527 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4529 * ...the word that follows the redirection operator
4530 * shall be subjected to tilde expansion, parameter expansion,
4531 * command substitution, arithmetic expansion, and quote
4532 * removal. Pathname expansion shall not be performed
4533 * on the word by a non-interactive shell; an interactive
4534 * shell may perform it, but shall do so only when
4535 * the expansion would result in one word."
4537 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4538 /* Cater for >\file case:
4539 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4540 * Same with heredocs:
4541 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4543 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
4544 unbackslash(ctx->pending_redirect->rd_filename);
4545 /* Is it <<"HEREDOC"? */
4546 if (word->o_quoted) {
4547 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4550 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4551 ctx->pending_redirect = NULL;
4553 /* If this word wasn't an assignment, next ones definitely
4554 * can't be assignments. Even if they look like ones. */
4555 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4556 && word->o_assignment != WORD_IS_KEYWORD
4558 word->o_assignment = NOT_ASSIGNMENT;
4560 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4561 command->assignment_cnt++;
4562 word->o_assignment = MAYBE_ASSIGNMENT;
4566 # if ENABLE_HUSH_CASE
4567 if (ctx->ctx_dsemicolon
4568 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4570 /* already done when ctx_dsemicolon was set to 1: */
4571 /* ctx->ctx_res_w = RES_MATCH; */
4572 ctx->ctx_dsemicolon = 0;
4575 if (!command->argv /* if it's the first word... */
4576 # if ENABLE_HUSH_LOOPS
4577 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4578 && ctx->ctx_res_w != RES_IN
4580 # if ENABLE_HUSH_CASE
4581 && ctx->ctx_res_w != RES_CASE
4584 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4585 if (reserved_word(word, ctx)) {
4586 o_reset_to_empty_unquoted(word);
4587 debug_printf_parse("done_word return %d\n",
4588 (ctx->ctx_res_w == RES_SNTX));
4589 return (ctx->ctx_res_w == RES_SNTX);
4593 if (command->group) {
4594 /* "{ echo foo; } echo bar" - bad */
4595 syntax_error_at(word->data);
4596 debug_printf_parse("done_word return 1: syntax error, "
4597 "groups and arglists don't mix\n");
4600 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4601 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4602 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4603 /* (otherwise it's known to be not empty and is already safe) */
4605 /* exclude "$@" - it can expand to no word despite "" */
4606 char *p = word->data;
4607 while (p[0] == SPECIAL_VAR_SYMBOL
4608 && (p[1] & 0x7f) == '@'
4609 && p[2] == SPECIAL_VAR_SYMBOL
4613 if (p == word->data || p[0] != '\0') {
4614 /* saw no "$@", or not only "$@" but some
4615 * real text is there too */
4616 /* insert "empty variable" reference, this makes
4617 * e.g. "", $empty"" etc to not disappear */
4618 o_addchr(word, SPECIAL_VAR_SYMBOL);
4619 o_addchr(word, SPECIAL_VAR_SYMBOL);
4622 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4623 debug_print_strings("word appended to argv", command->argv);
4626 #if ENABLE_HUSH_LOOPS
4627 if (ctx->ctx_res_w == RES_FOR) {
4629 || !is_well_formed_var_name(command->argv[0], '\0')
4631 /* bash says just "not a valid identifier" */
4632 syntax_error("not a valid identifier in for");
4635 /* Force FOR to have just one word (variable name) */
4636 /* NB: basically, this makes hush see "for v in ..."
4637 * syntax as if it is "for v; in ...". FOR and IN become
4638 * two pipe structs in parse tree. */
4639 done_pipe(ctx, PIPE_SEQ);
4642 #if ENABLE_HUSH_CASE
4643 /* Force CASE to have just one word */
4644 if (ctx->ctx_res_w == RES_CASE) {
4645 done_pipe(ctx, PIPE_SEQ);
4649 o_reset_to_empty_unquoted(word);
4651 debug_printf_parse("done_word return 0\n");
4656 /* Peek ahead in the input to find out if we have a "&n" construct,
4657 * as in "2>&1", that represents duplicating a file descriptor.
4659 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4660 * REDIRFD_SYNTAX_ERR if syntax error,
4661 * REDIRFD_TO_FILE if no & was seen,
4662 * or the number found.
4665 #define parse_redir_right_fd(as_string, input) \
4666 parse_redir_right_fd(input)
4668 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4674 return REDIRFD_TO_FILE;
4676 ch = i_getch(input); /* get the & */
4677 nommu_addchr(as_string, ch);
4680 ch = i_getch(input);
4681 nommu_addchr(as_string, ch);
4682 return REDIRFD_CLOSE;
4686 while (ch != EOF && isdigit(ch)) {
4687 d = d*10 + (ch-'0');
4689 ch = i_getch(input);
4690 nommu_addchr(as_string, ch);
4695 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4697 bb_error_msg("ambiguous redirect");
4698 return REDIRFD_SYNTAX_ERR;
4701 /* Return code is 0 normal, 1 if a syntax error is detected
4703 static int parse_redirect(struct parse_context *ctx,
4706 struct in_str *input)
4708 struct command *command = ctx->command;
4709 struct redir_struct *redir;
4710 struct redir_struct **redirp;
4713 dup_num = REDIRFD_TO_FILE;
4714 if (style != REDIRECT_HEREDOC) {
4715 /* Check for a '>&1' type redirect */
4716 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4717 if (dup_num == REDIRFD_SYNTAX_ERR)
4720 int ch = i_peek(input);
4721 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4722 if (dup_num) { /* <<-... */
4723 ch = i_getch(input);
4724 nommu_addchr(&ctx->as_string, ch);
4729 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4730 int ch = i_peek(input);
4732 /* >|FILE redirect ("clobbering" >).
4733 * Since we do not support "set -o noclobber" yet,
4734 * >| and > are the same for now. Just eat |.
4736 ch = i_getch(input);
4737 nommu_addchr(&ctx->as_string, ch);
4741 /* Create a new redir_struct and append it to the linked list */
4742 redirp = &command->redirects;
4743 while ((redir = *redirp) != NULL) {
4744 redirp = &(redir->next);
4746 *redirp = redir = xzalloc(sizeof(*redir));
4747 /* redir->next = NULL; */
4748 /* redir->rd_filename = NULL; */
4749 redir->rd_type = style;
4750 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4752 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4753 redir_table[style].descrip);
4755 redir->rd_dup = dup_num;
4756 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4757 /* Erik had a check here that the file descriptor in question
4758 * is legit; I postpone that to "run time"
4759 * A "-" representation of "close me" shows up as a -3 here */
4760 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4761 redir->rd_fd, redir->rd_dup);
4763 /* Set ctx->pending_redirect, so we know what to do at the
4764 * end of the next parsed word. */
4765 ctx->pending_redirect = redir;
4770 /* If a redirect is immediately preceded by a number, that number is
4771 * supposed to tell which file descriptor to redirect. This routine
4772 * looks for such preceding numbers. In an ideal world this routine
4773 * needs to handle all the following classes of redirects...
4774 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4775 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4776 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4777 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4779 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4781 * ... If n is quoted, the number shall not be recognized as part of
4782 * the redirection expression. For example:
4784 * writes the character 2 into file a"
4785 * We are getting it right by setting ->o_quoted on any \<char>
4787 * A -1 return means no valid number was found,
4788 * the caller should use the appropriate default for this redirection.
4790 static int redirect_opt_num(o_string *o)
4794 if (o->data == NULL)
4796 num = bb_strtou(o->data, NULL, 10);
4797 if (errno || num < 0)
4799 o_reset_to_empty_unquoted(o);
4804 #define fetch_till_str(as_string, input, word, skip_tabs) \
4805 fetch_till_str(input, word, skip_tabs)
4807 static char *fetch_till_str(o_string *as_string,
4808 struct in_str *input,
4812 o_string heredoc = NULL_O_STRING;
4818 ch = i_getch(input);
4819 nommu_addchr(as_string, ch);
4821 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4822 heredoc.data[past_EOL] = '\0';
4823 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4824 return heredoc.data;
4827 o_addchr(&heredoc, ch);
4828 past_EOL = heredoc.length;
4831 ch = i_getch(input);
4832 nommu_addchr(as_string, ch);
4833 } while (skip_tabs && ch == '\t');
4834 } while (ch == '\n');
4837 o_free_unsafe(&heredoc);
4840 o_addchr(&heredoc, ch);
4841 nommu_addchr(as_string, ch);
4845 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4846 * and load them all. There should be exactly heredoc_cnt of them.
4848 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4850 struct pipe *pi = ctx->list_head;
4852 while (pi && heredoc_cnt) {
4854 struct command *cmd = pi->cmds;
4856 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4858 cmd->argv ? cmd->argv[0] : "NONE");
4859 for (i = 0; i < pi->num_cmds; i++) {
4860 struct redir_struct *redir = cmd->redirects;
4862 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4863 i, cmd->argv ? cmd->argv[0] : "NONE");
4865 if (redir->rd_type == REDIRECT_HEREDOC) {
4868 redir->rd_type = REDIRECT_HEREDOC2;
4869 /* redir->dup is (ab)used to indicate <<- */
4870 p = fetch_till_str(&ctx->as_string, input,
4871 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4873 syntax_error("unexpected EOF in here document");
4876 free(redir->rd_filename);
4877 redir->rd_filename = p;
4880 redir = redir->next;
4887 /* Should be 0. If it isn't, it's a parse error */
4889 bb_error_msg_and_die("heredoc BUG 2");
4895 #if ENABLE_HUSH_TICK
4896 static FILE *generate_stream_from_string(const char *s)
4899 int pid, channel[2];
4905 pid = BB_MMU ? fork() : vfork();
4907 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4909 if (pid == 0) { /* child */
4910 disable_restore_tty_pgrp_on_exit();
4911 /* Process substitution is not considered to be usual
4912 * 'command execution'.
4913 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4920 close(channel[0]); /* NB: close _first_, then move fd! */
4921 xmove_fd(channel[1], 1);
4922 /* Prevent it from trying to handle ctrl-z etc */
4923 IF_HUSH_JOB(G.run_list_level = 1;)
4925 reset_traps_to_defaults();
4926 parse_and_run_string(s);
4927 _exit(G.last_exitcode);
4929 /* We re-execute after vfork on NOMMU. This makes this script safe:
4930 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4931 * huge=`cat BIG` # was blocking here forever
4934 re_execute_shell(&to_free,
4942 #if ENABLE_HUSH_FAST
4944 //bb_error_msg("[%d] fork in generate_stream_from_string: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4946 enable_restore_tty_pgrp_on_exit();
4951 pf = fdopen(channel[0], "r");
4955 /* Return code is exit status of the process that is run. */
4956 static int process_command_subs(o_string *dest, const char *s)
4959 struct in_str pipe_str;
4962 pf = generate_stream_from_string(s);
4965 close_on_exec_on(fileno(pf));
4967 /* Now send results of command back into original context */
4968 setup_file_in_str(&pipe_str, pf);
4970 while ((ch = i_getch(&pipe_str)) != EOF) {
4976 o_addchr(dest, '\n');
4979 o_addQchr(dest, ch);
4982 debug_printf("done reading from pipe, pclose()ing\n");
4983 /* Note: we got EOF, and we just close the read end of the pipe.
4984 * We do not wait for the `cmd` child to terminate. bash and ash do.
4986 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4987 * `false`; echo $? - bash outputs "1"
4990 debug_printf("closed FILE from child. return 0\n");
4995 static int parse_group(o_string *dest, struct parse_context *ctx,
4996 struct in_str *input, int ch)
4998 /* dest contains characters seen prior to ( or {.
4999 * Typically it's empty, but for function defs,
5000 * it contains function name (without '()'). */
5001 struct pipe *pipe_list;
5003 struct command *command = ctx->command;
5005 debug_printf_parse("parse_group entered\n");
5006 #if ENABLE_HUSH_FUNCTIONS
5007 if (ch == '(' && !dest->o_quoted) {
5009 if (done_word(dest, ctx))
5012 goto skip; /* (... */
5013 if (command->argv[1]) { /* word word ... (... */
5014 syntax_error_unexpected_ch('(');
5017 /* it is "word(..." or "word (..." */
5019 ch = i_getch(input);
5020 while (ch == ' ' || ch == '\t');
5022 syntax_error_unexpected_ch(ch);
5025 nommu_addchr(&ctx->as_string, ch);
5027 ch = i_getch(input);
5028 while (ch == ' ' || ch == '\t' || ch == '\n');
5030 syntax_error_unexpected_ch(ch);
5033 nommu_addchr(&ctx->as_string, ch);
5034 command->grp_type = GRP_FUNCTION;
5038 if (command->argv /* word [word]{... */
5039 || dest->length /* word{... */
5040 || dest->o_quoted /* ""{... */
5043 debug_printf_parse("parse_group return 1: "
5044 "syntax error, groups and arglists don't mix\n");
5048 #if ENABLE_HUSH_FUNCTIONS
5054 command->grp_type = GRP_SUBSHELL;
5056 /* bash does not allow "{echo...", requires whitespace */
5057 ch = i_getch(input);
5058 if (ch != ' ' && ch != '\t' && ch != '\n') {
5059 syntax_error_unexpected_ch(ch);
5062 nommu_addchr(&ctx->as_string, ch);
5067 char *as_string = NULL;
5069 pipe_list = parse_stream(&as_string, input, endch);
5072 o_addstr(&ctx->as_string, as_string);
5074 /* empty ()/{} or parse error? */
5075 if (!pipe_list || pipe_list == ERR_PTR) {
5076 /* parse_stream already emitted error msg */
5080 debug_printf_parse("parse_group return 1: "
5081 "parse_stream returned %p\n", pipe_list);
5084 command->group = pipe_list;
5086 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5087 command->group_as_string = as_string;
5088 debug_printf_parse("end of group, remembering as:'%s'\n",
5089 command->group_as_string);
5092 debug_printf_parse("parse_group return 0\n");
5094 /* command remains "open", available for possible redirects */
5097 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5098 /* Subroutines for copying $(...) and `...` things */
5099 static void add_till_backquote(o_string *dest, struct in_str *input);
5101 static void add_till_single_quote(o_string *dest, struct in_str *input)
5104 int ch = i_getch(input);
5106 syntax_error_unterm_ch('\'');
5107 /*xfunc_die(); - redundant */
5114 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5115 static void add_till_double_quote(o_string *dest, struct in_str *input)
5118 int ch = i_getch(input);
5120 syntax_error_unterm_ch('"');
5121 /*xfunc_die(); - redundant */
5125 if (ch == '\\') { /* \x. Copy both chars. */
5127 ch = i_getch(input);
5131 add_till_backquote(dest, input);
5135 //if (ch == '$') ...
5138 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5140 * "Within the backquoted style of command substitution, backslash
5141 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5142 * The search for the matching backquote shall be satisfied by the first
5143 * backquote found without a preceding backslash; during this search,
5144 * if a non-escaped backquote is encountered within a shell comment,
5145 * a here-document, an embedded command substitution of the $(command)
5146 * form, or a quoted string, undefined results occur. A single-quoted
5147 * or double-quoted string that begins, but does not end, within the
5148 * "`...`" sequence produces undefined results."
5150 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5152 static void add_till_backquote(o_string *dest, struct in_str *input)
5155 int ch = i_getch(input);
5157 syntax_error_unterm_ch('`');
5158 /*xfunc_die(); - redundant */
5163 /* \x. Copy both chars unless it is \` */
5164 int ch2 = i_getch(input);
5166 syntax_error_unterm_ch('`');
5167 /*xfunc_die(); - redundant */
5169 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5176 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5177 * quoting and nested ()s.
5178 * "With the $(command) style of command substitution, all characters
5179 * following the open parenthesis to the matching closing parenthesis
5180 * constitute the command. Any valid shell script can be used for command,
5181 * except a script consisting solely of redirections which produces
5182 * unspecified results."
5184 * echo $(echo '(TEST)' BEST) (TEST) BEST
5185 * echo $(echo 'TEST)' BEST) TEST) BEST
5186 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5188 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5192 int ch = i_getch(input);
5194 syntax_error_unterm_ch(')');
5195 /*xfunc_die(); - redundant */
5203 if (i_peek(input) == ')') {
5211 add_till_single_quote(dest, input);
5216 add_till_double_quote(dest, input);
5221 /* \x. Copy verbatim. Important for \(, \) */
5222 ch = i_getch(input);
5224 syntax_error_unterm_ch(')');
5225 /*xfunc_die(); - redundant */
5232 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5234 /* Return code: 0 for OK, 1 for syntax error */
5236 #define handle_dollar(as_string, dest, input) \
5237 handle_dollar(dest, input)
5239 static int handle_dollar(o_string *as_string,
5241 struct in_str *input)
5243 int ch = i_peek(input); /* first character after the $ */
5244 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5246 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5248 ch = i_getch(input);
5249 nommu_addchr(as_string, ch);
5251 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5253 debug_printf_parse(": '%c'\n", ch);
5254 o_addchr(dest, ch | quote_mask);
5257 if (!isalnum(ch) && ch != '_')
5259 ch = i_getch(input);
5260 nommu_addchr(as_string, ch);
5262 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5263 } else if (isdigit(ch)) {
5265 ch = i_getch(input);
5266 nommu_addchr(as_string, ch);
5267 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5268 debug_printf_parse(": '%c'\n", ch);
5269 o_addchr(dest, ch | quote_mask);
5270 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5271 } else switch (ch) {
5273 case '!': /* last bg pid */
5274 case '?': /* last exit code */
5275 case '#': /* number of args */
5276 case '*': /* args */
5277 case '@': /* args */
5278 goto make_one_char_var;
5280 bool first_char, all_digits;
5283 ch = i_getch(input);
5284 nommu_addchr(as_string, ch);
5285 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5287 /* TODO: maybe someone will try to escape the '}' */
5292 ch = i_getch(input);
5293 nommu_addchr(as_string, ch);
5300 /* ${#var}: length of var contents */
5307 /* They're being verbose and doing ${?} */
5308 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5313 && ( (all_digits && !isdigit(ch))
5314 || (!all_digits && !isalnum(ch) && ch != '_')
5317 /* handle parameter expansions
5318 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5323 case ':': /* null modifier */
5324 if (expansion == 0) {
5325 debug_printf_parse(": null modifier\n");
5330 case '#': /* remove prefix */
5331 case '%': /* remove suffix */
5332 if (expansion == 0) {
5333 debug_printf_parse(": remove suffix/prefix\n");
5338 case '-': /* default value */
5339 case '=': /* assign default */
5340 case '+': /* alternative */
5341 case '?': /* error indicate */
5342 debug_printf_parse(": parameter expansion\n");
5347 syntax_error_unterm_str("${name}");
5348 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5353 debug_printf_parse(": '%c'\n", ch);
5354 o_addchr(dest, ch | quote_mask);
5358 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5361 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5366 ch = i_getch(input);
5367 nommu_addchr(as_string, ch);
5368 # if ENABLE_SH_MATH_SUPPORT
5369 if (i_peek(input) == '(') {
5370 ch = i_getch(input);
5371 nommu_addchr(as_string, ch);
5372 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5373 o_addchr(dest, /*quote_mask |*/ '+');
5377 add_till_closing_paren(dest, input, true);
5380 o_addstr(as_string, dest->data + pos);
5381 o_addchr(as_string, ')');
5382 o_addchr(as_string, ')');
5385 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5389 # if ENABLE_HUSH_TICK
5390 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5391 o_addchr(dest, quote_mask | '`');
5395 add_till_closing_paren(dest, input, false);
5398 o_addstr(as_string, dest->data + pos);
5399 o_addchr(as_string, '`');
5402 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5408 ch = i_getch(input);
5409 nommu_addchr(as_string, ch);
5411 if (isalnum(ch)) { /* it's $_name or $_123 */
5417 /* $_ Shell or shell script name; or last cmd name */
5418 /* $- Option flags set by set builtin or shell options (-i etc) */
5420 o_addQchr(dest, '$');
5422 debug_printf_parse("handle_dollar return 0\n");
5427 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5428 parse_stream_dquoted(dest, input, dquote_end)
5430 static int parse_stream_dquoted(o_string *as_string,
5432 struct in_str *input,
5439 ch = i_getch(input);
5441 nommu_addchr(as_string, ch);
5442 if (ch == dquote_end) { /* may be only '"' or EOF */
5443 if (dest->o_assignment == NOT_ASSIGNMENT)
5444 dest->o_escape ^= 1;
5445 debug_printf_parse("parse_stream_dquoted return 0\n");
5448 /* note: can't move it above ch == dquote_end check! */
5450 syntax_error_unterm_ch('"');
5451 /*xfunc_die(); - redundant */
5455 next = i_peek(input);
5457 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5458 ch, ch, dest->o_escape);
5461 syntax_error("\\<eof>");
5465 * "The backslash retains its special meaning [in "..."]
5466 * only when followed by one of the following characters:
5467 * $, `, ", \, or <newline>. A double quote may be quoted
5468 * within double quotes by preceding it with a backslash."
5470 if (strchr("$`\"\\\n", next) != NULL) {
5471 ch = i_getch(input);
5473 o_addqchr(dest, ch);
5474 nommu_addchr(as_string, ch);
5477 o_addqchr(dest, '\\');
5478 nommu_addchr(as_string, '\\');
5483 if (handle_dollar(as_string, dest, input) != 0) {
5484 debug_printf_parse("parse_stream_dquoted return 1: "
5485 "handle_dollar returned non-0\n");
5490 #if ENABLE_HUSH_TICK
5492 //int pos = dest->length;
5493 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5494 o_addchr(dest, 0x80 | '`');
5495 add_till_backquote(dest, input);
5496 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5497 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5501 o_addQchr(dest, ch);
5503 && (dest->o_assignment == MAYBE_ASSIGNMENT
5504 || dest->o_assignment == WORD_IS_KEYWORD)
5505 && is_well_formed_var_name(dest->data, '=')
5507 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5513 * Scan input until EOF or end_trigger char.
5514 * Return a list of pipes to execute, or NULL on EOF
5515 * or if end_trigger character is met.
5516 * On syntax error, exit is shell is not interactive,
5517 * reset parsing machinery and start parsing anew,
5518 * or return ERR_PTR.
5520 static struct pipe *parse_stream(char **pstring,
5521 struct in_str *input,
5524 struct parse_context ctx;
5525 o_string dest = NULL_O_STRING;
5529 /* Double-quote state is handled in the state variable is_in_dquote.
5530 * A single-quote triggers a bypass of the main loop until its mate is
5531 * found. When recursing, quote state is passed in via dest->o_escape.
5533 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5534 end_trigger ? : 'X');
5537 G.ifs = get_local_var_value("IFS");
5542 #if ENABLE_HUSH_INTERACTIVE
5543 input->promptmode = 0; /* PS1 */
5545 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5546 initialize_context(&ctx);
5551 const char *is_special;
5555 redir_type redir_style;
5558 /* dest.o_quoted = 1; - already is (see below) */
5559 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5562 /* We reached closing '"' */
5565 ch = i_getch(input);
5566 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5567 ch, ch, dest.o_escape);
5572 syntax_error_unterm_str("here document");
5575 /* end_trigger == '}' case errors out earlier,
5576 * checking only ')' */
5577 if (end_trigger == ')') {
5578 syntax_error_unterm_ch('('); /* exits */
5579 /* goto parse_error; */
5582 if (done_word(&dest, &ctx)) {
5586 done_pipe(&ctx, PIPE_SEQ);
5588 /* If we got nothing... */
5589 /* (this makes bare "&" cmd a no-op.
5590 * bash says: "syntax error near unexpected token '&'") */
5591 if (pi->num_cmds == 0
5592 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5598 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5600 *pstring = ctx.as_string.data;
5602 o_free_unsafe(&ctx.as_string);
5605 debug_printf_parse("parse_stream return %p\n", pi);
5608 nommu_addchr(&ctx.as_string, ch);
5609 is_ifs = strchr(G.ifs, ch);
5610 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5611 "\\$\"" IF_HUSH_TICK("`") /* always special */
5614 if (!is_special && !is_ifs) { /* ordinary char */
5616 o_addQchr(&dest, ch);
5617 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5618 || dest.o_assignment == WORD_IS_KEYWORD)
5620 && is_well_formed_var_name(dest.data, '=')
5622 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5628 if (done_word(&dest, &ctx)) {
5632 #if ENABLE_HUSH_CASE
5633 /* "case ... in <newline> word) ..." -
5634 * newlines are ignored (but ';' wouldn't be) */
5635 if (ctx.command->argv == NULL
5636 && ctx.ctx_res_w == RES_MATCH
5641 /* Treat newline as a command separator. */
5642 done_pipe(&ctx, PIPE_SEQ);
5643 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5645 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5650 dest.o_assignment = MAYBE_ASSIGNMENT;
5652 /* note: if (is_ifs) continue;
5653 * will still trigger for us */
5657 /* "cmd}" or "cmd }..." without semicolon or &:
5658 * } is an ordinary char in this case, even inside { cmd; }
5659 * Pathological example: { ""}; } should exec "}" cmd
5662 if (!IS_NULL_CMD(ctx.command) /* cmd } */
5663 || dest.length != 0 /* word} */
5664 || dest.o_quoted /* ""} */
5668 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5669 goto skip_end_trigger;
5670 /* else: } does terminate a group */
5673 if (end_trigger && end_trigger == ch
5674 && (ch != ';' || heredoc_cnt == 0)
5675 #if ENABLE_HUSH_CASE
5677 || ctx.ctx_res_w != RES_MATCH
5678 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
5683 /* This is technically valid:
5684 * { cat <<HERE; }; echo Ok
5688 * but we don't support this.
5689 * We require heredoc to be in enclosing {}/(),
5692 syntax_error_unterm_str("here document");
5695 if (done_word(&dest, &ctx)) {
5698 done_pipe(&ctx, PIPE_SEQ);
5699 dest.o_assignment = MAYBE_ASSIGNMENT;
5700 /* Do we sit outside of any if's, loops or case's? */
5702 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5706 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5708 *pstring = ctx.as_string.data;
5710 o_free_unsafe(&ctx.as_string);
5713 debug_printf_parse("parse_stream return %p: "
5714 "end_trigger char found\n",
5716 return ctx.list_head;
5725 next = i_peek(input);
5728 /* Catch <, > before deciding whether this word is
5729 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5732 redir_fd = redirect_opt_num(&dest);
5733 if (done_word(&dest, &ctx)) {
5736 redir_style = REDIRECT_OVERWRITE;
5738 redir_style = REDIRECT_APPEND;
5739 ch = i_getch(input);
5740 nommu_addchr(&ctx.as_string, ch);
5743 else if (next == '(') {
5744 syntax_error(">(process) not supported");
5748 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5750 continue; /* back to top of while (1) */
5752 redir_fd = redirect_opt_num(&dest);
5753 if (done_word(&dest, &ctx)) {
5756 redir_style = REDIRECT_INPUT;
5758 redir_style = REDIRECT_HEREDOC;
5760 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5761 ch = i_getch(input);
5762 nommu_addchr(&ctx.as_string, ch);
5763 } else if (next == '>') {
5764 redir_style = REDIRECT_IO;
5765 ch = i_getch(input);
5766 nommu_addchr(&ctx.as_string, ch);
5769 else if (next == '(') {
5770 syntax_error("<(process) not supported");
5774 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5776 continue; /* back to top of while (1) */
5779 if (dest.o_assignment == MAYBE_ASSIGNMENT
5780 /* check that we are not in word in "a=1 2>word b=1": */
5781 && !ctx.pending_redirect
5783 /* ch is a special char and thus this word
5784 * cannot be an assignment */
5785 dest.o_assignment = NOT_ASSIGNMENT;
5790 if (dest.length == 0) {
5793 if (ch == EOF || ch == '\n')
5796 /* note: we do not add it to &ctx.as_string */
5798 nommu_addchr(&ctx.as_string, '\n');
5800 o_addQchr(&dest, ch);
5805 syntax_error("\\<eof>");
5808 ch = i_getch(input);
5810 o_addchr(&dest, '\\');
5811 nommu_addchr(&ctx.as_string, '\\');
5812 o_addchr(&dest, ch);
5813 nommu_addchr(&ctx.as_string, ch);
5814 /* Example: echo Hello \2>file
5815 * we need to know that word 2 is quoted */
5820 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5821 debug_printf_parse("parse_stream parse error: "
5822 "handle_dollar returned non-0\n");
5829 ch = i_getch(input);
5831 syntax_error_unterm_ch('\'');
5832 /*xfunc_die(); - redundant */
5834 nommu_addchr(&ctx.as_string, ch);
5837 o_addqchr(&dest, ch);
5842 is_in_dquote ^= 1; /* invert */
5843 if (dest.o_assignment == NOT_ASSIGNMENT)
5846 #if ENABLE_HUSH_TICK
5851 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5852 o_addchr(&dest, '`');
5856 add_till_backquote(&dest, input);
5858 o_addstr(&ctx.as_string, dest.data + pos);
5859 o_addchr(&ctx.as_string, '`');
5861 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5862 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5867 #if ENABLE_HUSH_CASE
5870 if (done_word(&dest, &ctx)) {
5873 done_pipe(&ctx, PIPE_SEQ);
5874 #if ENABLE_HUSH_CASE
5875 /* Eat multiple semicolons, detect
5876 * whether it means something special */
5881 ch = i_getch(input);
5882 nommu_addchr(&ctx.as_string, ch);
5883 if (ctx.ctx_res_w == RES_CASE_BODY) {
5884 ctx.ctx_dsemicolon = 1;
5885 ctx.ctx_res_w = RES_MATCH;
5891 /* We just finished a cmd. New one may start
5892 * with an assignment */
5893 dest.o_assignment = MAYBE_ASSIGNMENT;
5896 if (done_word(&dest, &ctx)) {
5900 ch = i_getch(input);
5901 nommu_addchr(&ctx.as_string, ch);
5902 done_pipe(&ctx, PIPE_AND);
5904 done_pipe(&ctx, PIPE_BG);
5908 if (done_word(&dest, &ctx)) {
5911 #if ENABLE_HUSH_CASE
5912 if (ctx.ctx_res_w == RES_MATCH)
5913 break; /* we are in case's "word | word)" */
5915 if (next == '|') { /* || */
5916 ch = i_getch(input);
5917 nommu_addchr(&ctx.as_string, ch);
5918 done_pipe(&ctx, PIPE_OR);
5920 /* we could pick up a file descriptor choice here
5921 * with redirect_opt_num(), but bash doesn't do it.
5922 * "echo foo 2| cat" yields "foo 2". */
5927 #if ENABLE_HUSH_CASE
5928 /* "case... in [(]word)..." - skip '(' */
5929 if (ctx.ctx_res_w == RES_MATCH
5930 && ctx.command->argv == NULL /* not (word|(... */
5931 && dest.length == 0 /* not word(... */
5932 && dest.o_quoted == 0 /* not ""(... */
5938 if (parse_group(&dest, &ctx, input, ch) != 0) {
5943 #if ENABLE_HUSH_CASE
5944 if (ctx.ctx_res_w == RES_MATCH)
5948 /* proper use of this character is caught by end_trigger:
5949 * if we see {, we call parse_group(..., end_trigger='}')
5950 * and it will match } earlier (not here). */
5951 syntax_error_unexpected_ch(ch);
5955 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5961 struct parse_context *pctx;
5962 IF_HAS_KEYWORDS(struct parse_context *p2;)
5964 /* Clean up allocated tree.
5965 * Samples for finding leaks on syntax error recovery path.
5966 * Run them from interactive shell, watch pmap `pidof hush`.
5967 * while if false; then false; fi do break; done
5969 * while if false; then false; fi; do break; fi
5970 * Samples to catch leaks at execution:
5971 * while if (true | {true;}); then echo ok; fi; do break; done
5972 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5976 /* Update pipe/command counts,
5977 * otherwise freeing may miss some */
5978 done_pipe(pctx, PIPE_SEQ);
5979 debug_printf_clean("freeing list %p from ctx %p\n",
5980 pctx->list_head, pctx);
5981 debug_print_tree(pctx->list_head, 0);
5982 free_pipe_list(pctx->list_head);
5983 debug_printf_clean("freed list %p\n", pctx->list_head);
5985 o_free_unsafe(&pctx->as_string);
5987 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5991 IF_HAS_KEYWORDS(pctx = p2;)
5992 } while (HAS_KEYWORDS && pctx);
5993 /* Free text, clear all dest fields */
5995 /* If we are not in top-level parse, we return,
5996 * our caller will propagate error.
5998 if (end_trigger != ';') {
6006 /* Discard cached input, force prompt */
6008 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6013 /* Executing from string: eval, sh -c '...'
6014 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6015 * end_trigger controls how often we stop parsing
6016 * NUL: parse all, execute, return
6017 * ';': parse till ';' or newline, execute, repeat till EOF
6019 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6022 struct pipe *pipe_list;
6024 pipe_list = parse_stream(NULL, inp, end_trigger);
6025 if (!pipe_list) /* EOF */
6027 debug_print_tree(pipe_list, 0);
6028 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6029 run_and_free_list(pipe_list);
6033 static void parse_and_run_string(const char *s)
6035 struct in_str input;
6036 setup_string_in_str(&input, s);
6037 parse_and_run_stream(&input, '\0');
6040 static void parse_and_run_file(FILE *f)
6042 struct in_str input;
6043 setup_file_in_str(&input, f);
6044 parse_and_run_stream(&input, ';');
6047 /* Called a few times only (or even once if "sh -c") */
6048 static void block_signals(int second_time)
6053 mask = (1 << SIGQUIT);
6054 if (G_interactive_fd) {
6055 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6056 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6057 mask |= SPECIAL_JOB_SIGS;
6059 G.non_DFL_mask = mask;
6062 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6066 sigaddset(&G.blocked_set, sig);
6070 sigdelset(&G.blocked_set, SIGCHLD);
6072 sigprocmask(SIG_SETMASK, &G.blocked_set,
6073 second_time ? NULL : &G.inherited_set);
6074 /* POSIX allows shell to re-enable SIGCHLD
6075 * even if it was SIG_IGN on entry */
6076 #if ENABLE_HUSH_FAST
6077 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6079 signal(SIGCHLD, SIGCHLD_handler);
6082 signal(SIGCHLD, SIG_DFL);
6088 static void maybe_set_to_sigexit(int sig)
6090 void (*handler)(int);
6091 /* non_DFL_mask'ed signals are, well, masked,
6092 * no need to set handler for them.
6094 if (!((G.non_DFL_mask >> sig) & 1)) {
6095 handler = signal(sig, sigexit);
6096 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6097 signal(sig, handler);
6100 /* Set handlers to restore tty pgrp and exit */
6101 static void set_fatal_handlers(void)
6103 /* We _must_ restore tty pgrp on fatal signals */
6105 maybe_set_to_sigexit(SIGILL );
6106 maybe_set_to_sigexit(SIGFPE );
6107 maybe_set_to_sigexit(SIGBUS );
6108 maybe_set_to_sigexit(SIGSEGV);
6109 maybe_set_to_sigexit(SIGTRAP);
6110 } /* else: hush is perfect. what SEGV? */
6111 maybe_set_to_sigexit(SIGABRT);
6112 /* bash 3.2 seems to handle these just like 'fatal' ones */
6113 maybe_set_to_sigexit(SIGPIPE);
6114 maybe_set_to_sigexit(SIGALRM);
6115 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6116 * if we aren't interactive... but in this case
6117 * we never want to restore pgrp on exit, and this fn is not called */
6118 /*maybe_set_to_sigexit(SIGHUP );*/
6119 /*maybe_set_to_sigexit(SIGTERM);*/
6120 /*maybe_set_to_sigexit(SIGINT );*/
6124 static int set_mode(const char cstate, const char mode)
6126 int state = (cstate == '-' ? 1 : 0);
6128 case 'n': G.fake_mode = state; break;
6129 case 'x': /*G.debug_mode = state;*/ break;
6130 default: return EXIT_FAILURE;
6132 return EXIT_SUCCESS;
6135 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6136 int hush_main(int argc, char **argv)
6138 static const struct variable const_shell_ver = {
6140 .varstr = (char*)hush_version_str,
6141 .max_len = 1, /* 0 can provoke free(name) */
6145 int signal_mask_is_inited = 0;
6148 struct variable *cur_var;
6151 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6152 G.last_exitcode = EXIT_SUCCESS;
6154 G.argv0_for_re_execing = argv[0];
6156 /* Deal with HUSH_VERSION */
6157 G.shell_ver = const_shell_ver; /* copying struct here */
6158 G.top_var = &G.shell_ver;
6159 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6160 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6161 /* Initialize our shell local variables with the values
6162 * currently living in the environment */
6163 cur_var = G.top_var;
6166 char *value = strchr(*e, '=');
6167 if (value) { /* paranoia */
6168 cur_var->next = xzalloc(sizeof(*cur_var));
6169 cur_var = cur_var->next;
6170 cur_var->varstr = *e;
6171 cur_var->max_len = strlen(*e);
6172 cur_var->flg_export = 1;
6176 debug_printf_env("putenv '%s'\n", hush_version_str);
6177 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
6178 #if ENABLE_FEATURE_EDITING
6179 G.line_input_state = new_line_input_t(FOR_SHELL);
6181 G.global_argc = argc;
6182 G.global_argv = argv;
6183 /* Initialize some more globals to non-zero values */
6185 cmdedit_update_prompt();
6187 if (setjmp(die_jmp)) {
6188 /* xfunc has failed! die die die */
6189 /* no EXIT traps, this is an escape hatch! */
6191 hush_exit(xfunc_error_retval);
6194 /* Shell is non-interactive at first. We need to call
6195 * block_signals(0) if we are going to execute "sh <script>",
6196 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6197 * If we later decide that we are interactive, we run block_signals(0)
6198 * (or re-run block_signals(1) if we ran block_signals(0) before)
6199 * in order to intercept (more) signals.
6203 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6205 opt = getopt(argc, argv, "c:xins"
6208 # if ENABLE_HUSH_FUNCTIONS
6218 G.root_pid = getpid();
6219 G.global_argv = argv + optind;
6220 if (!argv[optind]) {
6221 /* -c 'script' (no params): prevent empty $0 */
6222 *--G.global_argv = argv[0];
6224 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
6225 G.global_argc = argc - optind;
6226 block_signals(0); /* 0: called 1st time */
6227 parse_and_run_string(optarg);
6230 /* Well, we cannot just declare interactiveness,
6231 * we have to have some stuff (ctty, etc) */
6232 /* G_interactive_fd++; */
6235 /* "-s" means "read from stdin", but this is how we always
6236 * operate, so simply do nothing here. */
6239 case '<': /* "big heredoc" support */
6240 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6243 G.root_pid = bb_strtou(optarg, &optarg, 16);
6245 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6247 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6248 # if ENABLE_HUSH_LOOPS
6250 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6255 set_local_var(xstrdup(optarg), 0, opt == 'R');
6257 # if ENABLE_HUSH_FUNCTIONS
6259 struct function *funcp = new_function(optarg);
6260 /* funcp->name is already set to optarg */
6261 /* funcp->body is set to NULL. It's a special case. */
6262 funcp->body_as_string = argv[optind];
6270 if (!set_mode('-', opt))
6274 fprintf(stderr, "Usage: sh [FILE]...\n"
6275 " or: sh -c command [args]...\n\n");
6281 } /* option parsing loop */
6284 G.root_pid = getpid();
6286 /* If we are login shell... */
6287 if (argv[0] && argv[0][0] == '-') {
6289 debug_printf("sourcing /etc/profile\n");
6290 input = fopen_for_read("/etc/profile");
6291 if (input != NULL) {
6292 close_on_exec_on(fileno(input));
6293 block_signals(0); /* 0: called 1st time */
6294 signal_mask_is_inited = 1;
6295 parse_and_run_file(input);
6298 /* bash: after sourcing /etc/profile,
6299 * tries to source (in the given order):
6300 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6301 * stopping on first found. --noprofile turns this off.
6302 * bash also sources ~/.bash_logout on exit.
6303 * If called as sh, skips .bash_XXX files.
6310 * "bash <script>" (which is never interactive (unless -i?))
6311 * sources $BASH_ENV here (without scanning $PATH).
6312 * If called as sh, does the same but with $ENV.
6314 debug_printf("running script '%s'\n", argv[optind]);
6315 G.global_argv = argv + optind;
6316 G.global_argc = argc - optind;
6317 input = xfopen_for_read(argv[optind]);
6318 close_on_exec_on(fileno(input));
6319 if (!signal_mask_is_inited)
6320 block_signals(0); /* 0: called 1st time */
6321 parse_and_run_file(input);
6322 #if ENABLE_FEATURE_CLEAN_UP
6328 /* Up to here, shell was non-interactive. Now it may become one.
6329 * NB: don't forget to (re)run block_signals(0/1) as needed.
6332 /* A shell is interactive if the '-i' flag was given,
6333 * or if all of the following conditions are met:
6335 * no arguments remaining or the -s flag given
6336 * standard input is a terminal
6337 * standard output is a terminal
6338 * Refer to Posix.2, the description of the 'sh' utility.
6341 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6342 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6343 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
6344 if (G_saved_tty_pgrp < 0)
6345 G_saved_tty_pgrp = 0;
6347 /* try to dup stdin to high fd#, >= 255 */
6348 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6349 if (G_interactive_fd < 0) {
6350 /* try to dup to any fd */
6351 G_interactive_fd = dup(STDIN_FILENO);
6352 if (G_interactive_fd < 0) {
6354 G_interactive_fd = 0;
6355 G_saved_tty_pgrp = 0;
6358 // TODO: track & disallow any attempts of user
6359 // to (inadvertently) close/redirect G_interactive_fd
6361 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6362 if (G_interactive_fd) {
6363 close_on_exec_on(G_interactive_fd);
6365 if (G_saved_tty_pgrp) {
6366 /* If we were run as 'hush &', sleep until we are
6367 * in the foreground (tty pgrp == our pgrp).
6368 * If we get started under a job aware app (like bash),
6369 * make sure we are now in charge so we don't fight over
6370 * who gets the foreground */
6372 pid_t shell_pgrp = getpgrp();
6373 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6374 if (G_saved_tty_pgrp == shell_pgrp)
6376 /* send TTIN to ourself (should stop us) */
6377 kill(- shell_pgrp, SIGTTIN);
6381 /* Block some signals */
6382 block_signals(signal_mask_is_inited);
6384 if (G_saved_tty_pgrp) {
6385 /* Set other signals to restore saved_tty_pgrp */
6386 set_fatal_handlers();
6387 /* Put ourselves in our own process group
6388 * (bash, too, does this only if ctty is available) */
6389 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6390 /* Grab control of the terminal */
6391 tcsetpgrp(G_interactive_fd, getpid());
6393 /* -1 is special - makes xfuncs longjmp, not exit
6394 * (we reset die_sleep = 0 whereever we [v]fork) */
6395 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6396 } else if (!signal_mask_is_inited) {
6397 block_signals(0); /* 0: called 1st time */
6398 } /* else: block_signals(0) was done before */
6399 #elif ENABLE_HUSH_INTERACTIVE
6400 /* No job control compiled in, only prompt/line editing */
6401 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6402 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6403 if (G_interactive_fd < 0) {
6404 /* try to dup to any fd */
6405 G_interactive_fd = dup(STDIN_FILENO);
6406 if (G_interactive_fd < 0)
6408 G_interactive_fd = 0;
6411 if (G_interactive_fd) {
6412 close_on_exec_on(G_interactive_fd);
6413 block_signals(signal_mask_is_inited);
6414 } else if (!signal_mask_is_inited) {
6418 /* We have interactiveness code disabled */
6419 if (!signal_mask_is_inited) {
6424 * if interactive but not a login shell, sources ~/.bashrc
6425 * (--norc turns this off, --rcfile <file> overrides)
6428 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6429 printf("\n\n%s hush - the humble shell\n", bb_banner);
6430 if (ENABLE_HUSH_HELP)
6431 puts("Enter 'help' for a list of built-in commands.");
6435 parse_and_run_file(stdin);
6438 #if ENABLE_FEATURE_CLEAN_UP
6439 if (G.cwd != bb_msg_unknown)
6441 cur_var = G.top_var->next;
6443 struct variable *tmp = cur_var;
6444 if (!cur_var->max_len)
6445 free(cur_var->varstr);
6446 cur_var = cur_var->next;
6450 hush_exit(G.last_exitcode);
6455 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6456 int lash_main(int argc, char **argv)
6458 //bb_error_msg("lash is deprecated, please use hush instead");
6459 return hush_main(argc, argv);
6467 static int builtin_true(char **argv UNUSED_PARAM)
6472 static int builtin_test(char **argv)
6479 return test_main(argc, argv - argc);
6482 static int builtin_echo(char **argv)
6489 return echo_main(argc, argv - argc);
6492 static int builtin_eval(char **argv)
6494 int rcode = EXIT_SUCCESS;
6497 char *str = expand_strvec_to_string(argv);
6499 * eval "echo Hi; done" ("done" is syntax error):
6500 * "echo Hi" will not execute too.
6502 parse_and_run_string(str);
6504 rcode = G.last_exitcode;
6509 static int builtin_cd(char **argv)
6511 const char *newdir = argv[1];
6512 if (newdir == NULL) {
6513 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6514 * bash says "bash: cd: HOME not set" and does nothing
6517 newdir = get_local_var_value("HOME") ? : "/";
6519 if (chdir(newdir)) {
6520 /* Mimic bash message exactly */
6521 bb_perror_msg("cd: %s", newdir);
6522 return EXIT_FAILURE;
6525 return EXIT_SUCCESS;
6528 static int builtin_exec(char **argv)
6530 if (*++argv == NULL)
6531 return EXIT_SUCCESS; /* bash does this */
6536 /* TODO: if exec fails, bash does NOT exit! We do... */
6537 pseudo_exec_argv(&dummy, argv, 0, NULL);
6542 static int builtin_exit(char **argv)
6544 debug_printf_exec("%s()\n", __func__);
6546 /* interactive bash:
6547 * # trap "echo EEE" EXIT
6550 * There are stopped jobs.
6551 * (if there are _stopped_ jobs, running ones don't count)
6554 # EEE (then bash exits)
6556 * we can use G.exiting = -1 as indicator "last cmd was exit"
6559 /* note: EXIT trap is run by hush_exit */
6560 if (*++argv == NULL)
6561 hush_exit(G.last_exitcode);
6562 /* mimic bash: exit 123abc == exit 255 + error msg */
6563 xfunc_error_retval = 255;
6564 /* bash: exit -2 == exit 254, no error msg */
6565 hush_exit(xatoi(*argv) & 0xff);
6568 static void print_escaped(const char *s)
6574 p = strchrnul(s, '\'');
6575 /* print 'xxxx', possibly just '' */
6576 printf("'%.*s'", (int)(p - s), s);
6581 /* s points to '; print "'''...'''" */
6583 do putchar('\''); while (*++s == '\'');
6588 static int builtin_export(char **argv)
6590 unsigned opt_unexport;
6592 if (argv[1] == NULL) {
6599 /* ash emits: export VAR='VAL'
6600 * bash: declare -x VAR="VAL"
6601 * we follow ash example */
6602 const char *s = *e++;
6603 const char *p = strchr(s, '=');
6605 if (!p) /* wtf? take next variable */
6608 printf("export %.*s", (int)(p - s) + 1, s);
6609 print_escaped(p + 1);
6613 /*fflush(stdout); - done after each builtin anyway */
6615 return EXIT_SUCCESS;
6618 #if ENABLE_HUSH_EXPORT_N
6619 /* "!": do not abort on errors */
6620 /* "+": stop at 1st non-option */
6621 opt_unexport = getopt32(argv, "!+n");
6622 if (opt_unexport == (unsigned)-1)
6623 return EXIT_FAILURE;
6633 /* So far we do not check that name is valid (TODO?) */
6635 if (strchr(name, '=') == NULL) {
6636 struct variable *var;
6638 var = get_local_var(name);
6640 /* export -n NAME (without =VALUE) */
6642 var->flg_export = 0;
6643 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
6645 } /* else: export -n NOT_EXISTING_VAR: no-op */
6648 /* export NAME (without =VALUE) */
6650 var->flg_export = 1;
6651 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6652 putenv(var->varstr);
6655 /* Exporting non-existing variable.
6656 * bash does not put it in environment,
6657 * but remembers that it is exported,
6658 * and does put it in env when it is set later.
6659 * We just set it to "" and export. */
6660 name = xasprintf("%s=", name);
6662 /* (Un)exporting NAME=VALUE */
6663 name = xstrdup(name);
6666 /*export:*/ (opt_unexport ? -1 : 1),
6671 return EXIT_SUCCESS;
6674 static int builtin_trap(char **argv)
6680 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6685 /* No args: print all trapped */
6686 for (i = 0; i < NSIG; ++i) {
6689 print_escaped(G.traps[i]);
6690 printf(" %s\n", get_signame(i));
6693 /*fflush(stdout); - done after each builtin anyway */
6694 return EXIT_SUCCESS;
6698 /* If first arg is a number: reset all specified signals */
6699 sig = bb_strtou(*argv, NULL, 10);
6705 sig = get_signum(*argv++);
6706 if (sig < 0 || sig >= NSIG) {
6708 /* Mimic bash message exactly */
6709 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
6714 G.traps[sig] = xstrdup(new_cmd);
6716 debug_printf("trap: setting SIG%s (%i) to '%s'",
6717 get_signame(sig), sig, G.traps[sig]);
6719 /* There is no signal for 0 (EXIT) */
6724 sigaddset(&G.blocked_set, sig);
6726 /* There was a trap handler, we are removing it
6727 * (if sig has non-DFL handling,
6728 * we don't need to do anything) */
6729 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6731 sigdelset(&G.blocked_set, sig);
6734 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6738 if (!argv[1]) { /* no second arg */
6739 bb_error_msg("trap: invalid arguments");
6740 return EXIT_FAILURE;
6743 /* First arg is "-": reset all specified to default */
6744 /* First arg is "--": skip it, the rest is "handler SIGs..." */
6745 /* Everything else: set arg as signal handler
6746 * (includes "" case, which ignores signal) */
6747 if (argv[0][0] == '-') {
6748 if (argv[0][1] == '\0') { /* "-" */
6749 /* new_cmd remains NULL: "reset these sigs" */
6752 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
6755 /* else: "-something", no special meaning */
6760 goto process_sig_list;
6763 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
6764 static int builtin_type(char **argv)
6766 int ret = EXIT_SUCCESS;
6772 if (0) {} /* make conditional compile easier below */
6773 /*else if (find_alias(*argv))
6774 type = "an alias";*/
6775 #if ENABLE_HUSH_FUNCTIONS
6776 else if (find_function(*argv))
6777 type = "a function";
6779 else if (find_builtin(*argv))
6780 type = "a shell builtin";
6781 else if ((path = find_in_path(*argv)) != NULL)
6784 bb_error_msg("type: %s: not found", *argv);
6789 printf("%s is %s\n", *argv, type);
6797 /* built-in 'fg' and 'bg' handler */
6798 static int builtin_fg_bg(char **argv)
6803 if (!G_interactive_fd)
6804 return EXIT_FAILURE;
6806 /* If they gave us no args, assume they want the last backgrounded task */
6808 for (pi = G.job_list; pi; pi = pi->next) {
6809 if (pi->jobid == G.last_jobid) {
6813 bb_error_msg("%s: no current job", argv[0]);
6814 return EXIT_FAILURE;
6816 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6817 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6818 return EXIT_FAILURE;
6820 for (pi = G.job_list; pi; pi = pi->next) {
6821 if (pi->jobid == jobnum) {
6825 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6826 return EXIT_FAILURE;
6828 /* TODO: bash prints a string representation
6829 * of job being foregrounded (like "sleep 1 | cat") */
6830 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
6831 /* Put the job into the foreground. */
6832 tcsetpgrp(G_interactive_fd, pi->pgrp);
6835 /* Restart the processes in the job */
6836 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6837 for (i = 0; i < pi->num_cmds; i++) {
6838 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6839 pi->cmds[i].is_stopped = 0;
6841 pi->stopped_cmds = 0;
6843 i = kill(- pi->pgrp, SIGCONT);
6845 if (errno == ESRCH) {
6846 delete_finished_bg_job(pi);
6847 return EXIT_SUCCESS;
6849 bb_perror_msg("kill (SIGCONT)");
6852 if (argv[0][0] == 'f') {
6854 return checkjobs_and_fg_shell(pi);
6856 return EXIT_SUCCESS;
6860 #if ENABLE_HUSH_HELP
6861 static int builtin_help(char **argv UNUSED_PARAM)
6863 const struct built_in_command *x;
6866 "Built-in commands:\n"
6867 "------------------\n");
6868 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6869 printf("%s\t%s\n", x->cmd, x->descr);
6872 return EXIT_SUCCESS;
6877 static int builtin_jobs(char **argv UNUSED_PARAM)
6880 const char *status_string;
6882 for (job = G.job_list; job; job = job->next) {
6883 if (job->alive_cmds == job->stopped_cmds)
6884 status_string = "Stopped";
6886 status_string = "Running";
6888 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6890 return EXIT_SUCCESS;
6895 static int builtin_memleak(char **argv UNUSED_PARAM)
6900 /* Crude attempt to find where "free memory" starts,
6901 * sans fragmentation. */
6903 l = (unsigned long)p;
6906 if (l < (unsigned long)p) l = (unsigned long)p;
6909 if (!G.memleak_value)
6910 G.memleak_value = l;
6912 l -= G.memleak_value;
6919 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6924 static int builtin_pwd(char **argv UNUSED_PARAM)
6927 return EXIT_SUCCESS;
6930 static int builtin_read(char **argv)
6933 const char *name = "REPLY";
6937 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6938 * and _after_ that_ it will complain */
6939 if (!is_well_formed_var_name(name, '\0')) {
6940 /* Mimic bash message */
6941 bb_error_msg("read: '%s': not a valid identifier", name);
6946 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6948 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6949 return set_local_var(string, 0, 0);
6952 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6953 * built-in 'set' handler
6955 * set [-abCefhmnuvx] [-o option] [argument...]
6956 * set [+abCefhmnuvx] [+o option] [argument...]
6957 * set -- [argument...]
6960 * Implementations shall support the options in both their hyphen and
6961 * plus-sign forms. These options can also be specified as options to sh.
6963 * Write out all variables and their values: set
6964 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6965 * Turn on the -x and -v options: set -xv
6966 * Unset all positional parameters: set --
6967 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6968 * Set the positional parameters to the expansion of x, even if x expands
6969 * with a leading '-' or '+': set -- $x
6971 * So far, we only support "set -- [argument...]" and some of the short names.
6973 static int builtin_set(char **argv)
6976 char **pp, **g_argv;
6977 char *arg = *++argv;
6981 for (e = G.top_var; e; e = e->next)
6983 return EXIT_SUCCESS;
6987 if (!strcmp(arg, "--")) {
6991 if (arg[0] != '+' && arg[0] != '-')
6993 for (n = 1; arg[n]; ++n)
6994 if (set_mode(arg[0], arg[n]))
6996 } while ((arg = *++argv) != NULL);
6997 /* Now argv[0] is 1st argument */
7000 return EXIT_SUCCESS;
7003 /* NB: G.global_argv[0] ($0) is never freed/changed */
7004 g_argv = G.global_argv;
7005 if (G.global_args_malloced) {
7011 G.global_args_malloced = 1;
7012 pp = xzalloc(sizeof(pp[0]) * 2);
7013 pp[0] = g_argv[0]; /* retain $0 */
7016 /* This realloc's G.global_argv */
7017 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7024 return EXIT_SUCCESS;
7026 /* Nothing known, so abort */
7028 bb_error_msg("set: %s: invalid option", arg);
7029 return EXIT_FAILURE;
7032 static int builtin_shift(char **argv)
7038 if (n >= 0 && n < G.global_argc) {
7039 if (G.global_args_malloced) {
7042 free(G.global_argv[m++]);
7045 memmove(&G.global_argv[1], &G.global_argv[n+1],
7046 G.global_argc * sizeof(G.global_argv[0]));
7047 return EXIT_SUCCESS;
7049 return EXIT_FAILURE;
7052 static int builtin_source(char **argv)
7057 #if ENABLE_HUSH_FUNCTIONS
7061 if (*++argv == NULL)
7062 return EXIT_FAILURE;
7064 if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
7065 input = fopen_for_read(arg_path);
7068 input = fopen_or_warn(*argv, "r");
7070 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7071 return EXIT_FAILURE;
7073 close_on_exec_on(fileno(input));
7075 #if ENABLE_HUSH_FUNCTIONS
7076 sv_flg = G.flag_return_in_progress;
7077 /* "we are inside sourced file, ok to use return" */
7078 G.flag_return_in_progress = -1;
7080 save_and_replace_G_args(&sv, argv);
7082 parse_and_run_file(input);
7085 restore_G_args(&sv, argv);
7086 #if ENABLE_HUSH_FUNCTIONS
7087 G.flag_return_in_progress = sv_flg;
7090 return G.last_exitcode;
7093 static int builtin_umask(char **argv)
7100 mode_t old_mask = mask;
7103 rc = bb_parse_mode(argv[1], &mask);
7108 * bash: umask: 'q': invalid symbolic mode operator
7109 * bash: umask: 999: octal number out of range
7111 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7116 printf("%04o\n", (unsigned) mask);
7117 /* fall through and restore mask which we set to 0 */
7121 return !rc; /* rc != 0 - success */
7124 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7125 static int builtin_unset(char **argv)
7130 /* "!": do not abort on errors */
7131 /* "+": stop at 1st non-option */
7132 opts = getopt32(argv, "!+vf");
7133 if (opts == (unsigned)-1)
7134 return EXIT_FAILURE;
7136 bb_error_msg("unset: -v and -f are exclusive");
7137 return EXIT_FAILURE;
7143 if (!(opts & 2)) { /* not -f */
7144 if (unset_local_var(*argv)) {
7145 /* unset <nonexistent_var> doesn't fail.
7146 * Error is when one tries to unset RO var.
7147 * Message was printed by unset_local_var. */
7151 #if ENABLE_HUSH_FUNCTIONS
7161 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7162 static int builtin_wait(char **argv)
7164 int ret = EXIT_SUCCESS;
7167 if (*++argv == NULL) {
7168 /* Don't care about wait results */
7169 /* Note 1: must wait until there are no more children */
7170 /* Note 2: must be interruptible */
7172 * $ sleep 3 & sleep 6 & wait
7177 * $ sleep 3 & sleep 6 & wait
7181 * ^C <-- after ~4 sec from keyboard
7184 sigaddset(&G.blocked_set, SIGCHLD);
7185 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7188 if (errno == ECHILD)
7190 /* Wait for SIGCHLD or any other signal of interest */
7191 /* sigtimedwait with infinite timeout: */
7192 sig = sigwaitinfo(&G.blocked_set, NULL);
7194 sig = check_and_run_traps(sig);
7195 if (sig && sig != SIGCHLD) { /* see note 2 */
7201 sigdelset(&G.blocked_set, SIGCHLD);
7202 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7206 /* This is probably buggy wrt interruptible-ness */
7208 pid_t pid = bb_strtou(*argv, NULL, 10);
7210 /* mimic bash message */
7211 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
7212 return EXIT_FAILURE;
7214 if (waitpid(pid, &status, 0) == pid) {
7215 if (WIFSIGNALED(status))
7216 ret = 128 + WTERMSIG(status);
7217 else if (WIFEXITED(status))
7218 ret = WEXITSTATUS(status);
7222 bb_perror_msg("wait %s", *argv);
7231 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
7232 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
7235 def = bb_strtou(argv[1], NULL, 10);
7236 if (errno || def < def_min || argv[2]) {
7237 bb_error_msg("%s: bad arguments", argv[0]);
7245 #if ENABLE_HUSH_LOOPS
7246 static int builtin_break(char **argv)
7249 if (G.depth_of_loop == 0) {
7250 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7251 return EXIT_SUCCESS; /* bash compat */
7253 G.flag_break_continue++; /* BC_BREAK = 1 */
7255 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
7256 if (depth == UINT_MAX)
7257 G.flag_break_continue = BC_BREAK;
7258 if (G.depth_of_loop < depth)
7259 G.depth_break_continue = G.depth_of_loop;
7261 return EXIT_SUCCESS;
7264 static int builtin_continue(char **argv)
7266 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
7267 return builtin_break(argv);
7271 #if ENABLE_HUSH_FUNCTIONS
7272 static int builtin_return(char **argv)
7276 if (G.flag_return_in_progress != -1) {
7277 bb_error_msg("%s: not in a function or sourced script", argv[0]);
7278 return EXIT_FAILURE; /* bash compat */
7281 G.flag_return_in_progress = 1;
7284 * out of range: wraps around at 256, does not error out
7285 * non-numeric param:
7286 * f() { false; return qwe; }; f; echo $?
7287 * bash: return: qwe: numeric argument required <== we do this
7288 * 255 <== we also do this
7290 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);