1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
45 * Bash stuff (maybe optionally enable?):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
52 * grep for "TODO" and fix (some of them are easy)
53 * $var refs in function do not pick up values set by "var=val func"
55 * follow IFS rules more precisely, including update semantics
57 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
59 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
61 /* #include <dmalloc.h> */
68 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
72 /* Debug build knobs */
73 #define LEAK_HUNTING 0
74 #define BUILD_AS_NOMMU 0
75 /* Enable/disable sanity checks. Ok to enable in production,
76 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
77 * Keeping 1 for now even in released versions.
87 # define USE_FOR_NOMMU(...) __VA_ARGS__
88 # define USE_FOR_MMU(...)
91 #if defined SINGLE_APPLET_MAIN
92 /* STANDALONE does not make sense, and won't compile */
93 # undef CONFIG_FEATURE_SH_STANDALONE
94 # undef ENABLE_FEATURE_SH_STANDALONE
95 # undef IF_FEATURE_SH_STANDALONE
96 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
97 # define ENABLE_FEATURE_SH_STANDALONE 0
98 # define IF_FEATURE_SH_STANDALONE(...)
99 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
102 #if !ENABLE_HUSH_INTERACTIVE
103 # undef ENABLE_FEATURE_EDITING
104 # define ENABLE_FEATURE_EDITING 0
105 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
106 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
109 /* Do we support ANY keywords? */
110 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
111 # define HAS_KEYWORDS 1
112 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
113 # define IF_HAS_NO_KEYWORDS(...)
115 # define HAS_KEYWORDS 0
116 # define IF_HAS_KEYWORDS(...)
117 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
120 /* If you comment out one of these below, it will be #defined later
121 * to perform debug printfs to stderr: */
122 #define debug_printf(...) do {} while (0)
123 /* Finer-grained debug switches */
124 #define debug_printf_parse(...) do {} while (0)
125 #define debug_print_tree(a, b) do {} while (0)
126 #define debug_printf_exec(...) do {} while (0)
127 #define debug_printf_env(...) do {} while (0)
128 #define debug_printf_jobs(...) do {} while (0)
129 #define debug_printf_expand(...) do {} while (0)
130 #define debug_printf_glob(...) do {} while (0)
131 #define debug_printf_list(...) do {} while (0)
132 #define debug_printf_subst(...) do {} while (0)
133 #define debug_printf_clean(...) do {} while (0)
135 #define ERR_PTR ((void*)(long)1)
137 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
139 #define SPECIAL_VAR_SYMBOL 3
143 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
145 /* This supports saving pointers malloced in vfork child,
146 * to be freed in the parent.
149 typedef struct nommu_save_t {
151 struct variable *old_vars;
153 char **argv_from_re_execing;
157 /* The descrip member of this structure is only used to make
158 * debugging output pretty */
159 static const struct {
161 signed char default_fd;
165 { O_RDONLY, 0, "<" },
166 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
167 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
168 { O_RDONLY, 0, "<<" },
169 { O_CREAT|O_RDWR, 1, "<>" },
170 /* Should not be needed. Bogus default_fd helps in debugging */
171 /* { O_RDONLY, 77, "<<" }, */
174 typedef enum reserved_style {
183 #if ENABLE_HUSH_LOOPS
190 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
195 /* two pseudo-keywords support contrived "case" syntax: */
196 RES_MATCH , /* "word)" */
197 RES_CASEI , /* "this command is inside CASE" */
204 typedef struct o_string {
206 int length; /* position where data is appended */
208 /* Protect newly added chars against globbing
209 * (by prepending \ to *, ?, [, \) */
212 /* At least some part of the string was inside '' or "",
213 * possibly empty one: word"", wo''rd etc. */
215 smallint has_empty_slot;
216 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
219 MAYBE_ASSIGNMENT = 0,
220 DEFINITELY_ASSIGNMENT = 1,
222 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
224 /* Used for initialization: o_string foo = NULL_O_STRING; */
225 #define NULL_O_STRING { NULL }
227 /* I can almost use ordinary FILE*. Is open_memstream() universally
228 * available? Where is it documented? */
229 typedef struct in_str {
231 /* eof_flag=1: last char in ->p is really an EOF */
232 char eof_flag; /* meaningless if ->p == NULL */
234 #if ENABLE_HUSH_INTERACTIVE
236 smallint promptmode; /* 0: PS1, 1: PS2 */
239 int (*get) (struct in_str *);
240 int (*peek) (struct in_str *);
242 #define i_getch(input) ((input)->get(input))
243 #define i_peek(input) ((input)->peek(input))
245 struct redir_struct {
246 struct redir_struct *next;
247 char *rd_filename; /* filename */
248 int rd_fd; /* fd to redirect */
249 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
251 smallint rd_type; /* (enum redir_type) */
252 /* note: for heredocs, rd_filename contains heredoc delimiter,
253 * and subsequently heredoc itself; and rd_dup is a bitmask:
254 * 1: do we need to trim leading tabs?
255 * 2: is heredoc quoted (<<'delim' syntax) ?
258 typedef enum redir_type {
259 REDIRECT_INVALID = 0,
261 REDIRECT_OVERWRITE = 2,
263 REDIRECT_HEREDOC = 4,
265 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
268 REDIRFD_SYNTAX_ERR = -2,
269 REDIRFD_TO_FILE = -1,
270 /* otherwise, rd_fd is redirected to rd_dup */
272 HEREDOC_SKIPTABS = 1,
278 pid_t pid; /* 0 if exited */
279 int assignment_cnt; /* how many argv[i] are assignments? */
280 smallint is_stopped; /* is the command currently running? */
281 smallint grp_type; /* GRP_xxx */
283 #define GRP_SUBSHELL 1
284 #if ENABLE_HUSH_FUNCTIONS
285 # define GRP_FUNCTION 2
287 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
290 char *group_as_string;
292 #if ENABLE_HUSH_FUNCTIONS
293 struct function *child_func;
294 /* This field is used to prevent a bug here:
295 * while...do f1() {a;}; f1; f1 {b;}; f1; done
296 * When we execute "f1() {a;}" cmd, we create new function and clear
297 * cmd->group, cmd->group_as_string, cmd->argv[0].
298 * when we execute "f1 {b;}", we notice that f1 exists,
299 * and that it's "parent cmd" struct is still "alive",
300 * we put those fields back into cmd->xxx
301 * (struct function has ->parent_cmd ptr to facilitate that).
302 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
303 * Without this trick, loop would execute a;b;b;b;...
304 * instead of correct sequence a;b;a;b;...
305 * When command is freed, it severs the link
306 * (sets ->child_func->parent_cmd to NULL).
309 char **argv; /* command name and arguments */
310 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
311 * and on execution these are substituted with their values.
312 * Substitution can make _several_ words out of one argv[n]!
313 * Example: argv[0]=='.^C*^C.' here: echo .$*.
314 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
316 struct redir_struct *redirects; /* I/O redirections */
318 /* Is there anything in this command at all? */
319 #define IS_NULL_CMD(cmd) \
320 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
325 int num_cmds; /* total number of commands in pipe */
326 int alive_cmds; /* number of commands running (not exited) */
327 int stopped_cmds; /* number of commands alive, but stopped */
329 int jobid; /* job number */
330 pid_t pgrp; /* process group ID for the job */
331 char *cmdtext; /* name of job */
333 struct command *cmds; /* array of commands in pipe */
334 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
335 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
336 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
338 typedef enum pipe_style {
344 /* Is there anything in this pipe at all? */
345 #define IS_NULL_PIPE(pi) \
346 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
348 /* This holds pointers to the various results of parsing */
349 struct parse_context {
350 /* linked list of pipes */
351 struct pipe *list_head;
352 /* last pipe (being constructed right now) */
354 /* last command in pipe (being constructed right now) */
355 struct command *command;
356 /* last redirect in command->redirects list */
357 struct redir_struct *pending_redirect;
363 smallint ctx_inverted; /* "! cmd | cmd" */
365 smallint ctx_dsemicolon; /* ";;" seen */
367 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
369 /* group we are enclosed in:
370 * example: "if pipe1; pipe2; then pipe3; fi"
371 * when we see "if" or "then", we malloc and copy current context,
372 * and make ->stack point to it. then we parse pipeN.
373 * when closing "then" / fi" / whatever is found,
374 * we move list_head into ->stack->command->group,
375 * copy ->stack into current context, and delete ->stack.
376 * (parsing of { list } and ( list ) doesn't use this method)
378 struct parse_context *stack;
382 /* On program start, environ points to initial environment.
383 * putenv adds new pointers into it, unsetenv removes them.
384 * Neither of these (de)allocates the strings.
385 * setenv allocates new strings in malloc space and does putenv,
386 * and thus setenv is unusable (leaky) for shell's purposes */
387 #define setenv(...) setenv_is_leaky_dont_use()
389 struct variable *next;
390 char *varstr; /* points to "name=" portion */
391 int max_len; /* if > 0, name is part of initial env; else name is malloced */
392 smallint flg_export; /* putenv should be done on this var */
393 smallint flg_read_only;
401 #if ENABLE_HUSH_FUNCTIONS
403 struct function *next;
405 struct command *parent_cmd;
408 char *body_as_string;
414 /* "Globals" within this file */
415 /* Sorted roughly by size (smaller offsets == smaller code) */
417 /* interactive_fd != 0 means we are an interactive shell.
418 * If we are, then saved_tty_pgrp can also be != 0, meaning
419 * that controlling tty is available. With saved_tty_pgrp == 0,
420 * job control still works, but terminal signals
421 * (^C, ^Z, ^Y, ^\) won't work at all, and background
422 * process groups can only be created with "cmd &".
423 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
424 * to give tty to the foreground process group,
425 * and will take it back when the group is stopped (^Z)
428 #if ENABLE_HUSH_INTERACTIVE
429 /* 'interactive_fd' is a fd# open to ctty, if we have one
430 * _AND_ if we decided to act interactively */
434 # define G_interactive_fd (G.interactive_fd)
436 # define G_interactive_fd 0
438 #if ENABLE_FEATURE_EDITING
439 line_input_t *line_input_state;
446 pid_t saved_tty_pgrp;
447 struct pipe *job_list;
449 smallint flag_SIGINT;
450 #if ENABLE_HUSH_LOOPS
451 smallint flag_break_continue;
453 #if ENABLE_HUSH_FUNCTIONS
454 /* 0: outside of a function (or sourced file)
455 * -1: inside of a function, ok to use return builtin
456 * 1: return is invoked, skip all till end of func
458 smallint flag_return_in_progress;
461 smallint exiting; /* used to prevent EXIT trap recursion */
462 /* These four support $?, $#, and $1 */
463 smalluint last_exitcode;
464 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
465 smalluint global_args_malloced;
466 /* how many non-NULL argv's we have. NB: $# + 1 */
470 char *argv0_for_re_execing;
472 #if ENABLE_HUSH_LOOPS
473 unsigned depth_break_continue;
474 unsigned depth_of_loop;
478 struct variable *top_var; /* = &G.shell_ver (set in main()) */
479 struct variable shell_ver;
480 #if ENABLE_HUSH_FUNCTIONS
481 struct function *top_func;
483 /* Signal and trap handling */
484 // unsigned count_SIGCHLD;
485 // unsigned handled_SIGCHLD;
486 /* which signals have non-DFL handler (even with no traps set)? */
487 unsigned non_DFL_mask;
488 char **traps; /* char *traps[NSIG] */
489 sigset_t blocked_set;
490 sigset_t inherited_set;
492 unsigned long memleak_value;
495 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
497 #define G (*ptr_to_globals)
498 /* Not #defining name to G.name - this quickly gets unwieldy
499 * (too many defines). Also, I actually prefer to see when a variable
500 * is global, thus "G." prefix is a useful hint */
501 #define INIT_G() do { \
502 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
506 /* Function prototypes for builtins */
507 static int builtin_cd(char **argv);
508 static int builtin_echo(char **argv);
509 static int builtin_eval(char **argv);
510 static int builtin_exec(char **argv);
511 static int builtin_exit(char **argv);
512 static int builtin_export(char **argv);
514 static int builtin_fg_bg(char **argv);
515 static int builtin_jobs(char **argv);
518 static int builtin_help(char **argv);
521 static int builtin_memleak(char **argv);
523 static int builtin_pwd(char **argv);
524 static int builtin_read(char **argv);
525 static int builtin_set(char **argv);
526 static int builtin_shift(char **argv);
527 static int builtin_source(char **argv);
528 static int builtin_test(char **argv);
529 static int builtin_trap(char **argv);
530 static int builtin_true(char **argv);
531 static int builtin_umask(char **argv);
532 static int builtin_unset(char **argv);
533 static int builtin_wait(char **argv);
534 #if ENABLE_HUSH_LOOPS
535 static int builtin_break(char **argv);
536 static int builtin_continue(char **argv);
538 #if ENABLE_HUSH_FUNCTIONS
539 static int builtin_return(char **argv);
542 /* Table of built-in functions. They can be forked or not, depending on
543 * context: within pipes, they fork. As simple commands, they do not.
544 * When used in non-forking context, they can change global variables
545 * in the parent shell process. If forked, of course they cannot.
546 * For example, 'unset foo | whatever' will parse and run, but foo will
547 * still be set at the end. */
548 struct built_in_command {
550 int (*function)(char **argv);
553 #define BLTIN(cmd, func, help) { cmd, func, help }
555 #define BLTIN(cmd, func, help) { cmd, func }
559 /* For now, echo and test are unconditionally enabled.
560 * Maybe make it configurable? */
561 static const struct built_in_command bltins[] = {
562 BLTIN("." , builtin_source , "Run commands in a file"),
563 BLTIN(":" , builtin_true , "No-op"),
564 BLTIN("[" , builtin_test , "Test condition"),
566 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
568 #if ENABLE_HUSH_LOOPS
569 BLTIN("break" , builtin_break , "Exit from a loop"),
571 BLTIN("cd" , builtin_cd , "Change directory"),
572 #if ENABLE_HUSH_LOOPS
573 BLTIN("continue", builtin_continue, "Start new loop iteration"),
575 BLTIN("echo" , builtin_echo , "Write to stdout"),
576 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
577 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
578 BLTIN("exit" , builtin_exit , "Exit"),
579 BLTIN("export" , builtin_export , "Set environment variable"),
581 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
584 BLTIN("help" , builtin_help , "List shell built-in commands"),
587 BLTIN("jobs" , builtin_jobs , "List active jobs"),
590 BLTIN("memleak" , builtin_memleak , "Debug tool"),
592 BLTIN("pwd" , builtin_pwd , "Print current directory"),
593 BLTIN("read" , builtin_read , "Input environment variable"),
594 #if ENABLE_HUSH_FUNCTIONS
595 BLTIN("return" , builtin_return , "Return from a function"),
597 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
598 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
599 BLTIN("test" , builtin_test , "Test condition"),
600 BLTIN("trap" , builtin_trap , "Trap signals"),
601 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
602 BLTIN("umask" , builtin_umask , "Set file creation mask"),
603 BLTIN("unset" , builtin_unset , "Unset environment variable"),
604 BLTIN("wait" , builtin_wait , "Wait for process"),
611 /* prevent disasters with G.debug_indent < 0 */
612 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
613 # define debug_enter() (G.debug_indent++)
614 # define debug_leave() (G.debug_indent--)
616 # define indent() ((void)0)
617 # define debug_enter() ((void)0)
618 # define debug_leave() ((void)0)
622 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
625 #ifndef debug_printf_parse
626 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
629 #ifndef debug_printf_exec
630 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
633 #ifndef debug_printf_env
634 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
637 #ifndef debug_printf_jobs
638 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
639 # define DEBUG_JOBS 1
641 # define DEBUG_JOBS 0
644 #ifndef debug_printf_expand
645 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
646 # define DEBUG_EXPAND 1
648 # define DEBUG_EXPAND 0
651 #ifndef debug_printf_glob
652 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
653 # define DEBUG_GLOB 1
655 # define DEBUG_GLOB 0
658 #ifndef debug_printf_list
659 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
662 #ifndef debug_printf_subst
663 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
666 #ifndef debug_printf_clean
667 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
668 # define DEBUG_CLEAN 1
670 # define DEBUG_CLEAN 0
674 static void debug_print_strings(const char *prefix, char **vv)
677 fprintf(stderr, "%s:\n", prefix);
679 fprintf(stderr, " '%s'\n", *vv++);
682 #define debug_print_strings(prefix, vv) ((void)0)
686 /* Leak hunting. Use hush_leaktool.sh for post-processing.
689 static void *xxmalloc(int lineno, size_t size)
691 void *ptr = xmalloc((size + 0xff) & ~0xff);
692 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
695 static void *xxrealloc(int lineno, void *ptr, size_t size)
697 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
698 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
701 static char *xxstrdup(int lineno, const char *str)
703 char *ptr = xstrdup(str);
704 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
707 static void xxfree(void *ptr)
709 fdprintf(2, "free %p\n", ptr);
712 #define xmalloc(s) xxmalloc(__LINE__, s)
713 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
714 #define xstrdup(s) xxstrdup(__LINE__, s)
715 #define free(p) xxfree(p)
719 /* Syntax and runtime errors. They always abort scripts.
720 * In interactive use they usually discard unparsed and/or unexecuted commands
721 * and return to the prompt.
722 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
725 # define die_if_script(lineno, fmt...) die_if_script(fmt)
726 # define syntax_error(lineno, msg) syntax_error(msg)
727 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
728 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
729 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
730 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
733 static void die_if_script(unsigned lineno, const char *fmt, ...)
738 bb_error_msg("hush.c:%u", lineno);
741 bb_verror_msg(fmt, p, NULL);
743 if (!G_interactive_fd)
747 static void syntax_error(unsigned lineno, const char *msg)
750 die_if_script(lineno, "syntax error: %s", msg);
752 die_if_script(lineno, "syntax error", NULL);
755 static void syntax_error_at(unsigned lineno, const char *msg)
757 die_if_script(lineno, "syntax error at '%s'", msg);
760 /* It so happens that all such cases are totally fatal
761 * even if shell is interactive: EOF while looking for closing
762 * delimiter. There is nowhere to read stuff from after that,
763 * it's EOF! The only choice is to terminate.
765 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
766 static void syntax_error_unterm_ch(unsigned lineno, char ch)
771 die_if_script(lineno, "syntax error: unterminated %s", msg);
775 static void syntax_error_unterm_str(unsigned lineno, const char *s)
777 die_if_script(lineno, "syntax error: unterminated %s", s);
780 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
785 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
789 # undef die_if_script
791 # undef syntax_error_at
792 # undef syntax_error_unterm_ch
793 # undef syntax_error_unterm_str
794 # undef syntax_error_unexpected_ch
796 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
797 # define syntax_error(msg) syntax_error(__LINE__, msg)
798 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
799 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
800 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
801 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
805 #if ENABLE_HUSH_INTERACTIVE
806 static void cmdedit_update_prompt(void);
808 # define cmdedit_update_prompt()
814 static int glob_needed(const char *s)
819 if (*s == '*' || *s == '[' || *s == '?')
826 static int is_well_formed_var_name(const char *s, char terminator)
828 if (!s || !(isalpha(*s) || *s == '_'))
831 while (isalnum(*s) || *s == '_')
833 return *s == terminator;
836 /* Replace each \x with x in place, return ptr past NUL. */
837 static char *unbackslash(char *src)
843 if ((*dst++ = *src++) == '\0')
849 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
870 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
871 v[count1 + count2] = NULL;
874 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
878 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
880 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
881 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
884 #define add_strings_to_strings(strings, add, need_to_dup) \
885 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
888 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
889 static char **add_string_to_strings(char **strings, char *add)
894 return add_strings_to_strings(strings, v, /*dup:*/ 0);
897 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
899 char **ptr = add_string_to_strings(strings, add);
900 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
903 #define add_string_to_strings(strings, add) \
904 xx_add_string_to_strings(__LINE__, strings, add)
907 static void free_strings(char **strings)
922 /* Helpers for setting new $n and restoring them back
924 typedef struct save_arg_t {
928 smallint sv_g_malloced;
931 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
935 sv->sv_argv0 = argv[0];
936 sv->sv_g_argv = G.global_argv;
937 sv->sv_g_argc = G.global_argc;
938 sv->sv_g_malloced = G.global_args_malloced;
940 argv[0] = G.global_argv[0]; /* retain $0 */
941 G.global_argv = argv;
942 G.global_args_malloced = 0;
950 static void restore_G_args(save_arg_t *sv, char **argv)
954 if (G.global_args_malloced) {
955 /* someone ran "set -- arg1 arg2 ...", undo */
957 while (*++pp) /* note: does not free $0 */
961 argv[0] = sv->sv_argv0;
962 G.global_argv = sv->sv_g_argv;
963 G.global_argc = sv->sv_g_argc;
964 G.global_args_malloced = sv->sv_g_malloced;
968 /* Basic theory of signal handling in shell
969 * ========================================
970 * This does not describe what hush does, rather, it is current understanding
971 * what it _should_ do. If it doesn't, it's a bug.
972 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
974 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
975 * is finished or backgrounded. It is the same in interactive and
976 * non-interactive shells, and is the same regardless of whether
977 * a user trap handler is installed or a shell special one is in effect.
978 * ^C or ^Z from keyboard seem to execute "at once" because it usually
979 * backgrounds (i.e. stops) or kills all members of currently running
982 * Wait builtin in interruptible by signals for which user trap is set
983 * or by SIGINT in interactive shell.
985 * Trap handlers will execute even within trap handlers. (right?)
987 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
989 * If job control is off, backgrounded commands ("cmd &")
990 * have SIGINT, SIGQUIT set to SIG_IGN.
992 * Commands run in command substitution ("`cmd`")
993 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
995 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
996 * by the shell from its parent.
998 * Siganls which differ from SIG_DFL action
999 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1002 * SIGTERM (interactive): ignore
1003 * SIGHUP (interactive):
1004 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1005 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1006 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1007 * that all pipe members are stopped. Try this in bash:
1008 * while :; do :; done - ^Z does not background it
1009 * (while :; do :; done) - ^Z backgrounds it
1010 * SIGINT (interactive): wait for last pipe, ignore the rest
1011 * of the command line, show prompt. NB: ^C does not send SIGINT
1012 * to interactive shell while shell is waiting for a pipe,
1013 * since shell is bg'ed (is not in foreground process group).
1014 * Example 1: this waits 5 sec, but does not execute ls:
1015 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1016 * Example 2: this does not wait and does not execute ls:
1017 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1018 * Example 3: this does not wait 5 sec, but executes ls:
1019 * "sleep 5; ls -l" + press ^C
1021 * (What happens to signals which are IGN on shell start?)
1022 * (What happens with signal mask on shell start?)
1024 * Implementation in hush
1025 * ======================
1026 * We use in-kernel pending signal mask to determine which signals were sent.
1027 * We block all signals which we don't want to take action immediately,
1028 * i.e. we block all signals which need to have special handling as described
1029 * above, and all signals which have traps set.
1030 * After each pipe execution, we extract any pending signals via sigtimedwait()
1033 * unsigned non_DFL_mask: a mask of such "special" signals
1034 * sigset_t blocked_set: current blocked signal set
1037 * clear bit in blocked_set unless it is also in non_DFL_mask
1038 * "trap 'cmd' SIGxxx":
1039 * set bit in blocked_set (even if 'cmd' is '')
1040 * after [v]fork, if we plan to be a shell:
1041 * unblock signals with special interactive handling
1042 * (child shell is not interactive),
1043 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1044 * after [v]fork, if we plan to exec:
1045 * POSIX says pending signal mask is cleared in child - no need to clear it.
1046 * Restore blocked signal set to one inherited by shell just prior to exec.
1048 * Note: as a result, we do not use signal handlers much. The only uses
1049 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
1050 * and to restore tty pgrp on signal-induced exit.
1053 SPECIAL_INTERACTIVE_SIGS = 0
1059 SPECIAL_JOB_SIGS = 0
1066 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1068 // G.count_SIGCHLD++;
1073 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1074 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1075 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1076 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1078 /* Restores tty foreground process group, and exits.
1079 * May be called as signal handler for fatal signal
1080 * (will resend signal to itself, producing correct exit state)
1081 * or called directly with -EXITCODE.
1082 * We also call it if xfunc is exiting. */
1083 static void sigexit(int sig) NORETURN;
1084 static void sigexit(int sig)
1086 /* Disable all signals: job control, SIGPIPE, etc. */
1087 sigprocmask_allsigs(SIG_BLOCK);
1089 /* Careful: we can end up here after [v]fork. Do not restore
1090 * tty pgrp then, only top-level shell process does that */
1091 if (G.saved_tty_pgrp && getpid() == G.root_pid)
1092 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1094 /* Not a signal, just exit */
1098 kill_myself_with_sig(sig); /* does not return */
1102 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1103 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1107 /* Restores tty foreground process group, and exits. */
1108 static void hush_exit(int exitcode) NORETURN;
1109 static void hush_exit(int exitcode)
1111 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1112 /* Prevent recursion:
1113 * trap "echo Hi; exit" EXIT; exit
1115 char *argv[] = { NULL, G.traps[0], NULL };
1123 fflush(NULL); /* flush all streams */
1124 sigexit(- (exitcode & 0xff));
1130 static int check_and_run_traps(int sig)
1132 static const struct timespec zero_timespec = { 0, 0 };
1133 smalluint save_rcode;
1139 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1144 if (G.traps && G.traps[sig]) {
1145 if (G.traps[sig][0]) {
1146 /* We have user-defined handler */
1147 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1148 save_rcode = G.last_exitcode;
1151 G.last_exitcode = save_rcode;
1152 } /* else: "" trap, ignoring signal */
1155 /* not a trap: special action */
1158 // G.count_SIGCHLD++;
1161 /* Builtin was ^C'ed, make it look prettier: */
1168 /* bash is observed to signal whole process groups,
1169 * not individual processes */
1170 for (job = G.job_list; job; job = job->next) {
1173 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1174 if (kill(- job->pgrp, SIGHUP) == 0)
1175 kill(- job->pgrp, SIGCONT);
1180 default: /* ignored: */
1181 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1189 static const char *set_cwd(void)
1191 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1192 * we must not try to free(bb_msg_unknown) */
1193 if (G.cwd == bb_msg_unknown)
1195 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1197 G.cwd = bb_msg_unknown;
1203 * Shell and environment variable support
1205 static struct variable **get_ptr_to_local_var(const char *name)
1207 struct variable **pp;
1208 struct variable *cur;
1213 while ((cur = *pp) != NULL) {
1214 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1221 static struct variable *get_local_var(const char *name)
1223 struct variable **pp = get_ptr_to_local_var(name);
1229 static const char *get_local_var_value(const char *name)
1231 struct variable **pp = get_ptr_to_local_var(name);
1233 return strchr((*pp)->varstr, '=') + 1;
1237 /* str holds "NAME=VAL" and is expected to be malloced.
1238 * We take ownership of it.
1240 * 0: do not change export flag
1241 * (if creating new variable, flag will be 0)
1242 * 1: set export flag and putenv the variable
1243 * -1: clear export flag and unsetenv the variable
1244 * flg_read_only is set only when we handle -R var=val
1247 #define set_local_var(str, flg_export, flg_read_only) \
1248 set_local_var(str, flg_export)
1250 static int set_local_var(char *str, int flg_export, int flg_read_only)
1252 struct variable *cur;
1256 eq_sign = strchr(str, '=');
1257 if (!eq_sign) { /* not expected to ever happen? */
1262 name_len = eq_sign - str + 1; /* including '=' */
1263 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1265 if (strncmp(cur->varstr, str, name_len) != 0) {
1267 /* Bail out. Note that now cur points
1268 * to last var in linked list */
1274 /* We found an existing var with this name */
1275 if (cur->flg_read_only) {
1279 bb_error_msg("%s: readonly variable", str);
1283 if (flg_export == -1) {
1284 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1289 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1294 if (cur->max_len >= strlen(str)) {
1295 /* This one is from startup env, reuse space */
1296 strcpy(cur->varstr, str);
1299 /* max_len == 0 signifies "malloced" var, which we can
1300 * (and has to) free */
1304 goto set_str_and_exp;
1307 /* Not found - create next variable struct */
1308 cur->next = xzalloc(sizeof(*cur));
1314 cur->flg_read_only = flg_read_only;
1317 if (flg_export == 1)
1318 cur->flg_export = 1;
1319 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1320 cmdedit_update_prompt();
1321 if (cur->flg_export) {
1322 if (flg_export == -1) {
1323 cur->flg_export = 0;
1324 /* unsetenv was already done */
1326 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1327 return putenv(cur->varstr);
1333 static int unset_local_var_len(const char *name, int name_len)
1335 struct variable *cur;
1336 struct variable **var_pp;
1339 return EXIT_SUCCESS;
1340 var_pp = &G.top_var;
1341 while ((cur = *var_pp) != NULL) {
1342 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1343 if (cur->flg_read_only) {
1344 bb_error_msg("%s: readonly variable", name);
1345 return EXIT_FAILURE;
1347 *var_pp = cur->next;
1348 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1349 bb_unsetenv(cur->varstr);
1350 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1351 cmdedit_update_prompt();
1355 return EXIT_SUCCESS;
1357 var_pp = &cur->next;
1359 return EXIT_SUCCESS;
1362 static int unset_local_var(const char *name)
1364 return unset_local_var_len(name, strlen(name));
1367 static void unset_vars(char **strings)
1375 const char *eq = strchrnul(*v, '=');
1376 unset_local_var_len(*v, (int)(eq - *v));
1382 #if ENABLE_SH_MATH_SUPPORT
1383 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1384 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1385 static char *endofname(const char *name)
1393 if (!is_in_name(*p))
1399 static void arith_set_local_var(const char *name, const char *val, int flags)
1401 /* arith code doesnt malloc space, so do it for it */
1402 char *var = xasprintf("%s=%s", name, val);
1403 set_local_var(var, flags, 0);
1409 * Helpers for "var1=val1 var2=val2 cmd" feature
1411 static void add_vars(struct variable *var)
1413 struct variable *next;
1417 var->next = G.top_var;
1419 if (var->flg_export) {
1420 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1421 putenv(var->varstr);
1423 debug_printf_env("%s: restoring local '%s'\n", __func__, var->varstr);
1429 static struct variable *set_vars_and_save_old(char **strings)
1432 struct variable *old = NULL;
1438 struct variable *var_p;
1439 struct variable **var_pp;
1442 eq = strchr(*s, '=');
1445 var_pp = get_ptr_to_local_var(*s);
1448 /* Remove variable from global linked list */
1450 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1451 *var_pp = var_p->next;
1452 /* Add it to returned list */
1456 set_local_var(*s, 1, 0);
1467 static int static_get(struct in_str *i)
1476 static int static_peek(struct in_str *i)
1481 #if ENABLE_HUSH_INTERACTIVE
1483 static void cmdedit_update_prompt(void)
1485 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1486 G.PS1 = get_local_var_value("PS1");
1489 G.PS2 = get_local_var_value("PS2");
1497 static const char* setup_prompt_string(int promptmode)
1499 const char *prompt_str;
1500 debug_printf("setup_prompt_string %d ", promptmode);
1501 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1502 /* Set up the prompt */
1503 if (promptmode == 0) { /* PS1 */
1505 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1510 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1511 debug_printf("result '%s'\n", prompt_str);
1515 static void get_user_input(struct in_str *i)
1518 const char *prompt_str;
1520 prompt_str = setup_prompt_string(i->promptmode);
1521 #if ENABLE_FEATURE_EDITING
1522 /* Enable command line editing only while a command line
1523 * is actually being read */
1526 /* buglet: SIGINT will not make new prompt to appear _at once_,
1527 * only after <Enter>. (^C will work) */
1528 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1529 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1530 check_and_run_traps(0);
1531 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1532 i->eof_flag = (r < 0);
1533 if (i->eof_flag) { /* EOF/error detected */
1534 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1535 G.user_input_buf[1] = '\0';
1540 fputs(prompt_str, stdout);
1542 G.user_input_buf[0] = r = fgetc(i->file);
1543 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1544 //do we need check_and_run_traps(0)? (maybe only if stdin)
1545 } while (G.flag_SIGINT);
1546 i->eof_flag = (r == EOF);
1548 i->p = G.user_input_buf;
1551 #endif /* INTERACTIVE */
1553 /* This is the magic location that prints prompts
1554 * and gets data back from the user */
1555 static int file_get(struct in_str *i)
1559 /* If there is data waiting, eat it up */
1560 if (i->p && *i->p) {
1561 #if ENABLE_HUSH_INTERACTIVE
1565 if (i->eof_flag && !*i->p)
1567 /* note: ch is never NUL */
1569 /* need to double check i->file because we might be doing something
1570 * more complicated by now, like sourcing or substituting. */
1571 #if ENABLE_HUSH_INTERACTIVE
1572 if (G_interactive_fd && i->promptme && i->file == stdin) {
1575 } while (!*i->p); /* need non-empty line */
1576 i->promptmode = 1; /* PS2 */
1581 do ch = fgetc(i->file); while (ch == '\0');
1583 debug_printf("file_get: got '%c' %d\n", ch, ch);
1584 #if ENABLE_HUSH_INTERACTIVE
1591 /* All callers guarantee this routine will never
1592 * be used right after a newline, so prompting is not needed.
1594 static int file_peek(struct in_str *i)
1597 if (i->p && *i->p) {
1598 if (i->eof_flag && !i->p[1])
1601 /* note: ch is never NUL */
1603 do ch = fgetc(i->file); while (ch == '\0');
1604 i->eof_flag = (ch == EOF);
1605 i->peek_buf[0] = ch;
1606 i->peek_buf[1] = '\0';
1608 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1612 static void setup_file_in_str(struct in_str *i, FILE *f)
1614 i->peek = file_peek;
1616 #if ENABLE_HUSH_INTERACTIVE
1618 i->promptmode = 0; /* PS1 */
1624 static void setup_string_in_str(struct in_str *i, const char *s)
1626 i->peek = static_peek;
1627 i->get = static_get;
1628 #if ENABLE_HUSH_INTERACTIVE
1630 i->promptmode = 0; /* PS1 */
1640 #define B_CHUNK (32 * sizeof(char*))
1642 static void o_reset_to_empty_unquoted(o_string *o)
1650 static void o_free(o_string *o)
1653 memset(o, 0, sizeof(*o));
1656 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1661 static void o_grow_by(o_string *o, int len)
1663 if (o->length + len > o->maxlen) {
1664 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1665 o->data = xrealloc(o->data, 1 + o->maxlen);
1669 static void o_addchr(o_string *o, int ch)
1671 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1673 o->data[o->length] = ch;
1675 o->data[o->length] = '\0';
1678 static void o_addblock(o_string *o, const char *str, int len)
1681 memcpy(&o->data[o->length], str, len);
1683 o->data[o->length] = '\0';
1687 static void o_addstr(o_string *o, const char *str)
1689 o_addblock(o, str, strlen(str));
1691 static void nommu_addchr(o_string *o, int ch)
1697 #define nommu_addchr(o, str) ((void)0)
1700 static void o_addstr_with_NUL(o_string *o, const char *str)
1702 o_addblock(o, str, strlen(str) + 1);
1705 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1710 && (*str != '*' && *str != '?' && *str != '[')
1718 /* My analysis of quoting semantics tells me that state information
1719 * is associated with a destination, not a source.
1721 static void o_addqchr(o_string *o, int ch)
1724 char *found = strchr("*?[\\", ch);
1729 o->data[o->length] = '\\';
1732 o->data[o->length] = ch;
1734 o->data[o->length] = '\0';
1737 static void o_addQchr(o_string *o, int ch)
1740 if (o->o_escape && strchr("*?[\\", ch)) {
1742 o->data[o->length] = '\\';
1746 o->data[o->length] = ch;
1748 o->data[o->length] = '\0';
1751 static void o_addQstr(o_string *o, const char *str, int len)
1754 o_addblock(o, str, len);
1760 int ordinary_cnt = strcspn(str, "*?[\\");
1761 if (ordinary_cnt > len) /* paranoia */
1763 o_addblock(o, str, ordinary_cnt);
1764 if (ordinary_cnt == len)
1766 str += ordinary_cnt;
1767 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1771 if (ch) { /* it is necessarily one of "*?[\\" */
1773 o->data[o->length] = '\\';
1777 o->data[o->length] = ch;
1779 o->data[o->length] = '\0';
1783 /* A special kind of o_string for $VAR and `cmd` expansion.
1784 * It contains char* list[] at the beginning, which is grown in 16 element
1785 * increments. Actual string data starts at the next multiple of 16 * (char*).
1786 * list[i] contains an INDEX (int!) into this string data.
1787 * It means that if list[] needs to grow, data needs to be moved higher up
1788 * but list[i]'s need not be modified.
1789 * NB: remembering how many list[i]'s you have there is crucial.
1790 * o_finalize_list() operation post-processes this structure - calculates
1791 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1793 #if DEBUG_EXPAND || DEBUG_GLOB
1794 static void debug_print_list(const char *prefix, o_string *o, int n)
1796 char **list = (char**)o->data;
1797 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1801 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1802 prefix, list, n, string_start, o->length, o->maxlen);
1805 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1806 o->data + (int)list[i] + string_start,
1807 o->data + (int)list[i] + string_start);
1811 const char *p = o->data + (int)list[n - 1] + string_start;
1813 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1817 #define debug_print_list(prefix, o, n) ((void)0)
1820 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1821 * in list[n] so that it points past last stored byte so far.
1822 * It returns n+1. */
1823 static int o_save_ptr_helper(o_string *o, int n)
1825 char **list = (char**)o->data;
1829 if (!o->has_empty_slot) {
1830 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1831 string_len = o->length - string_start;
1832 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1833 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1834 /* list[n] points to string_start, make space for 16 more pointers */
1835 o->maxlen += 0x10 * sizeof(list[0]);
1836 o->data = xrealloc(o->data, o->maxlen + 1);
1837 list = (char**)o->data;
1838 memmove(list + n + 0x10, list + n, string_len);
1839 o->length += 0x10 * sizeof(list[0]);
1841 debug_printf_list("list[%d]=%d string_start=%d\n",
1842 n, string_len, string_start);
1845 /* We have empty slot at list[n], reuse without growth */
1846 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1847 string_len = o->length - string_start;
1848 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1849 n, string_len, string_start);
1850 o->has_empty_slot = 0;
1852 list[n] = (char*)(ptrdiff_t)string_len;
1856 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1857 static int o_get_last_ptr(o_string *o, int n)
1859 char **list = (char**)o->data;
1860 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1862 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1865 /* o_glob performs globbing on last list[], saving each result
1866 * as a new list[]. */
1867 static int o_glob(o_string *o, int n)
1873 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1875 return o_save_ptr_helper(o, n);
1876 pattern = o->data + o_get_last_ptr(o, n);
1877 debug_printf_glob("glob pattern '%s'\n", pattern);
1878 if (!glob_needed(pattern)) {
1880 o->length = unbackslash(pattern) - o->data;
1881 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1882 return o_save_ptr_helper(o, n);
1885 memset(&globdata, 0, sizeof(globdata));
1886 gr = glob(pattern, 0, NULL, &globdata);
1887 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1888 if (gr == GLOB_NOSPACE)
1889 bb_error_msg_and_die("out of memory during glob");
1890 if (gr == GLOB_NOMATCH) {
1891 globfree(&globdata);
1894 if (gr != 0) { /* GLOB_ABORTED ? */
1895 /* TODO: testcase for bad glob pattern behavior */
1896 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1898 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1899 char **argv = globdata.gl_pathv;
1900 o->length = pattern - o->data; /* "forget" pattern */
1902 o_addstr_with_NUL(o, *argv);
1903 n = o_save_ptr_helper(o, n);
1909 globfree(&globdata);
1911 debug_print_list("o_glob returning", o, n);
1915 /* If o->o_glob == 1, glob the string so far remembered.
1916 * Otherwise, just finish current list[] and start new */
1917 static int o_save_ptr(o_string *o, int n)
1919 if (o->o_glob) { /* if globbing is requested */
1920 /* If o->has_empty_slot, list[n] was already globbed
1921 * (if it was requested back then when it was filled)
1922 * so don't do that again! */
1923 if (!o->has_empty_slot)
1924 return o_glob(o, n); /* o_save_ptr_helper is inside */
1926 return o_save_ptr_helper(o, n);
1929 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1930 static char **o_finalize_list(o_string *o, int n)
1935 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1937 debug_print_list("finalized", o, n);
1938 debug_printf_expand("finalized n:%d\n", n);
1939 list = (char**)o->data;
1940 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1944 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1950 /* Expansion can recurse */
1951 #if ENABLE_HUSH_TICK
1952 static int process_command_subs(o_string *dest, const char *s);
1954 static char *expand_string_to_string(const char *str);
1956 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1957 parse_stream_dquoted(dest, input, dquote_end)
1959 static int parse_stream_dquoted(o_string *as_string,
1961 struct in_str *input,
1964 /* expand_strvec_to_strvec() takes a list of strings, expands
1965 * all variable references within and returns a pointer to
1966 * a list of expanded strings, possibly with larger number
1967 * of strings. (Think VAR="a b"; echo $VAR).
1968 * This new list is allocated as a single malloc block.
1969 * NULL-terminated list of char* pointers is at the beginning of it,
1970 * followed by strings themself.
1971 * Caller can deallocate entire list by single free(list). */
1973 /* Store given string, finalizing the word and starting new one whenever
1974 * we encounter IFS char(s). This is used for expanding variable values.
1975 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1976 static int expand_on_ifs(o_string *output, int n, const char *str)
1979 int word_len = strcspn(str, G.ifs);
1981 if (output->o_escape || !output->o_glob)
1982 o_addQstr(output, str, word_len);
1983 else /* protect backslashes against globbing up :) */
1984 o_addblock_duplicate_backslash(output, str, word_len);
1987 if (!*str) /* EOL - do not finalize word */
1989 o_addchr(output, '\0');
1990 debug_print_list("expand_on_ifs", output, n);
1991 n = o_save_ptr(output, n);
1992 str += strspn(str, G.ifs); /* skip ifs chars */
1994 debug_print_list("expand_on_ifs[1]", output, n);
1998 /* Helper to expand $((...)) and heredoc body. These act as if
1999 * they are in double quotes, with the exception that they are not :).
2000 * Just the rules are similar: "expand only $var and `cmd`"
2002 * Returns malloced string.
2003 * As an optimization, we return NULL if expansion is not needed.
2005 static char *expand_pseudo_dquoted(const char *str)
2008 struct in_str input;
2009 o_string dest = NULL_O_STRING;
2011 if (strchr(str, '$') == NULL
2012 #if ENABLE_HUSH_TICK
2013 && strchr(str, '`') == NULL
2019 /* We need to expand. Example:
2020 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2022 setup_string_in_str(&input, str);
2023 parse_stream_dquoted(NULL, &dest, &input, EOF);
2024 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2025 exp_str = expand_string_to_string(dest.data);
2026 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2027 o_free_unsafe(&dest);
2031 /* Expand all variable references in given string, adding words to list[]
2032 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2033 * to be filled). This routine is extremely tricky: has to deal with
2034 * variables/parameters with whitespace, $* and $@, and constructs like
2035 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2036 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2038 /* or_mask is either 0 (normal case) or 0x80
2039 * (expansion of right-hand side of assignment == 1-element expand.
2040 * It will also do no globbing, and thus we must not backslash-quote!) */
2047 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
2048 debug_print_list("expand_vars_to_list", output, n);
2049 n = o_save_ptr(output, n);
2050 debug_print_list("expand_vars_to_list[0]", output, n);
2052 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2055 char *dyn_val = NULL;
2056 const char *val = NULL;
2057 #if ENABLE_HUSH_TICK
2058 o_string subst_result = NULL_O_STRING;
2060 #if ENABLE_SH_MATH_SUPPORT
2061 char arith_buf[sizeof(arith_t)*3 + 2];
2063 o_addblock(output, arg, p - arg);
2064 debug_print_list("expand_vars_to_list[1]", output, n);
2066 p = strchr(p, SPECIAL_VAR_SYMBOL);
2068 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2069 /* "$@" is special. Even if quoted, it can still
2070 * expand to nothing (not even an empty string) */
2071 if ((first_ch & 0x7f) != '@')
2072 ored_ch |= first_ch;
2074 switch (first_ch & 0x7f) {
2075 /* Highest bit in first_ch indicates that var is double-quoted */
2077 val = utoa(G.root_pid);
2079 case '!': /* bg pid */
2080 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2082 case '?': /* exitcode */
2083 val = utoa(G.last_exitcode);
2085 case '#': /* argc */
2086 if (arg[1] != SPECIAL_VAR_SYMBOL)
2087 /* actually, it's a ${#var} */
2089 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2094 if (!G.global_argv[i])
2096 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2097 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2098 smallint sv = output->o_escape;
2099 /* unquoted var's contents should be globbed, so don't escape */
2100 output->o_escape = 0;
2101 while (G.global_argv[i]) {
2102 n = expand_on_ifs(output, n, G.global_argv[i]);
2103 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2104 if (G.global_argv[i++][0] && G.global_argv[i]) {
2105 /* this argv[] is not empty and not last:
2106 * put terminating NUL, start new word */
2107 o_addchr(output, '\0');
2108 debug_print_list("expand_vars_to_list[2]", output, n);
2109 n = o_save_ptr(output, n);
2110 debug_print_list("expand_vars_to_list[3]", output, n);
2113 output->o_escape = sv;
2115 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2116 * and in this case should treat it like '$*' - see 'else...' below */
2117 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2119 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2120 if (++i >= G.global_argc)
2122 o_addchr(output, '\0');
2123 debug_print_list("expand_vars_to_list[4]", output, n);
2124 n = o_save_ptr(output, n);
2126 } else { /* quoted $*: add as one word */
2128 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2129 if (!G.global_argv[++i])
2132 o_addchr(output, G.ifs[0]);
2136 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2137 /* "Empty variable", used to make "" etc to not disappear */
2141 #if ENABLE_HUSH_TICK
2142 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2145 /* Can't just stuff it into output o_string,
2146 * expanded result may need to be globbed
2147 * and $IFS-splitted */
2148 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2149 process_command_subs(&subst_result, arg);
2150 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2151 val = subst_result.data;
2154 #if ENABLE_SH_MATH_SUPPORT
2155 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2156 arith_eval_hooks_t hooks;
2161 arg++; /* skip '+' */
2162 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2163 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2165 exp_str = expand_pseudo_dquoted(arg);
2166 hooks.lookupvar = get_local_var_value;
2167 hooks.setvar = arith_set_local_var;
2168 hooks.endofname = endofname;
2169 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2173 const char *msg = "error in arithmetic";
2176 msg = "exponent less than 0";
2179 msg = "divide by 0";
2182 msg = "expression recursion loop detected";
2187 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2188 sprintf(arith_buf, arith_t_fmt, res);
2193 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2195 bool exp_len = false;
2196 bool exp_null = false;
2198 char exp_save = exp_save; /* for compiler */
2199 char exp_op = exp_op; /* for compiler */
2200 char *exp_word = exp_word; /* for compiler */
2204 arg[0] = first_ch & 0x7f;
2206 /* prepare for expansions */
2207 if (var[0] == '#') {
2208 /* handle length expansion ${#var} */
2212 /* maybe handle parameter expansion */
2213 exp_off = strcspn(var, ":-=+?%#");
2217 exp_save = var[exp_off];
2218 exp_null = exp_save == ':';
2219 exp_word = var + exp_off;
2222 exp_op = *exp_word++;
2223 var[exp_off] = '\0';
2227 /* lookup the variable in question */
2228 if (isdigit(var[0])) {
2229 /* handle_dollar() should have vetted var for us */
2231 if (i < G.global_argc)
2232 val = G.global_argv[i];
2233 /* else val remains NULL: $N with too big N */
2235 val = get_local_var_value(var);
2237 /* handle any expansions */
2239 debug_printf_expand("expand: length of '%s' = ", val);
2240 val = utoa(val ? strlen(val) : 0);
2241 debug_printf_expand("%s\n", val);
2242 } else if (exp_off) {
2243 if (exp_op == '%' || exp_op == '#') {
2245 /* we need to do a pattern match */
2248 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2249 if (exp_op == *exp_word) /* ## or %% */
2251 val = dyn_val = xstrdup(val);
2252 loc = scan(dyn_val, exp_word, match_at_left);
2253 if (match_at_left) /* # or ## */
2255 else if (loc) /* % or %% and match was found */
2259 /* we need to do an expansion */
2260 int exp_test = (!val || (exp_null && !val[0]));
2262 exp_test = !exp_test;
2263 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2264 exp_null ? "true" : "false", exp_test);
2266 if (exp_op == '?') {
2267 //TODO: how interactive bash aborts expansion mid-command?
2268 /* ${var?[error_msg_if_unset]} */
2269 /* ${var:?[error_msg_if_unset_or_null]} */
2270 /* mimic bash message */
2271 die_if_script("%s: %s",
2273 exp_word[0] ? exp_word : "parameter null or not set"
2279 if (exp_op == '=') {
2280 /* ${var=[word]} or ${var:=[word]} */
2281 if (isdigit(var[0]) || var[0] == '#') {
2282 /* mimic bash message */
2283 die_if_script("$%s: cannot assign in this way", var);
2286 char *new_var = xasprintf("%s=%s", var, val);
2287 set_local_var(new_var, 0, 0);
2293 var[exp_off] = exp_save;
2297 #if ENABLE_HUSH_TICK
2300 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2301 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2303 /* unquoted var's contents should be globbed, so don't escape */
2304 smallint sv = output->o_escape;
2305 output->o_escape = 0;
2306 n = expand_on_ifs(output, n, val);
2308 output->o_escape = sv;
2310 } else { /* quoted $VAR, val will be appended below */
2311 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2314 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2317 o_addQstr(output, val, strlen(val));
2320 /* Do the check to avoid writing to a const string */
2321 if (*p != SPECIAL_VAR_SYMBOL)
2322 *p = SPECIAL_VAR_SYMBOL;
2324 #if ENABLE_HUSH_TICK
2325 o_free(&subst_result);
2328 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2331 debug_print_list("expand_vars_to_list[a]", output, n);
2332 /* this part is literal, and it was already pre-quoted
2333 * if needed (much earlier), do not use o_addQstr here! */
2334 o_addstr_with_NUL(output, arg);
2335 debug_print_list("expand_vars_to_list[b]", output, n);
2336 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2337 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2340 /* allow to reuse list[n] later without re-growth */
2341 output->has_empty_slot = 1;
2343 o_addchr(output, '\0');
2348 static char **expand_variables(char **argv, int or_mask)
2353 o_string output = NULL_O_STRING;
2355 if (or_mask & 0x100) {
2356 output.o_escape = 1; /* protect against globbing for "$var" */
2357 /* (unquoted $var will temporarily switch it off) */
2364 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2367 debug_print_list("expand_variables", &output, n);
2369 /* output.data (malloced in one block) gets returned in "list" */
2370 list = o_finalize_list(&output, n);
2371 debug_print_strings("expand_variables[1]", list);
2375 static char **expand_strvec_to_strvec(char **argv)
2377 return expand_variables(argv, 0x100);
2380 /* Used for expansion of right hand of assignments */
2381 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2383 static char *expand_string_to_string(const char *str)
2385 char *argv[2], **list;
2387 argv[0] = (char*)str;
2389 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2391 if (!list[0] || list[1])
2392 bb_error_msg_and_die("BUG in varexp2");
2393 /* actually, just move string 2*sizeof(char*) bytes back */
2394 overlapping_strcpy((char*)list, list[0]);
2395 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2399 /* Used for "eval" builtin */
2400 static char* expand_strvec_to_string(char **argv)
2404 list = expand_variables(argv, 0x80);
2405 /* Convert all NULs to spaces */
2410 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2411 bb_error_msg_and_die("BUG in varexp3");
2412 /* bash uses ' ' regardless of $IFS contents */
2417 overlapping_strcpy((char*)list, list[0]);
2418 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2422 static char **expand_assignments(char **argv, int count)
2426 /* Expand assignments into one string each */
2427 for (i = 0; i < count; i++) {
2428 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2436 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2438 static void reset_traps_to_defaults(void)
2440 /* This function is always called in a child shell
2441 * after fork (not vfork, NOMMU doesn't use this function).
2442 * Child shells are not interactive.
2443 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2444 * Testcase: (while :; do :; done) + ^Z should background.
2445 * Same goes for SIGTERM, SIGHUP, SIGINT.
2450 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2453 /* Stupid. It can be done with *single* &= op, but we can't use
2454 * the fact that G.blocked_set is implemented as a bitmask... */
2455 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2459 sigdelset(&G.blocked_set, sig);
2466 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2467 mask = G.non_DFL_mask;
2468 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2472 G.traps[sig] = NULL;
2473 /* There is no signal for 0 (EXIT) */
2476 /* There was a trap handler, we are removing it.
2477 * But if sig still has non-DFL handling,
2478 * we should not unblock it. */
2481 sigdelset(&G.blocked_set, sig);
2483 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2488 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2489 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2491 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2492 char *heredoc_argv[4];
2493 struct variable *cur;
2494 #if ENABLE_HUSH_FUNCTIONS
2495 struct function *funcp;
2500 if (!g_argv0) { /* heredoc */
2501 argv = heredoc_argv;
2502 argv[0] = (char *) G.argv0_for_re_execing;
2503 argv[1] = (char *) "-<";
2504 argv[2] = (char *) s;
2506 pp = &argv[3]; /* used as pointer to empty environment */
2510 sprintf(param_buf, "-$%x:%x:%x" IF_HUSH_LOOPS(":%x")
2511 , (unsigned) G.root_pid
2512 , (unsigned) G.last_bg_pid
2513 , (unsigned) G.last_exitcode
2514 IF_HUSH_LOOPS(, G.depth_of_loop)
2516 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2517 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2520 for (cur = G.top_var; cur; cur = cur->next) {
2521 if (!cur->flg_export || cur->flg_read_only)
2524 #if ENABLE_HUSH_FUNCTIONS
2525 for (funcp = G.top_func; funcp; funcp = funcp->next)
2531 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2532 *pp++ = (char *) G.argv0_for_re_execing;
2534 for (cur = G.top_var; cur; cur = cur->next) {
2535 if (cur->varstr == hush_version_str)
2537 if (cur->flg_read_only) {
2538 *pp++ = (char *) "-R";
2539 *pp++ = cur->varstr;
2540 } else if (!cur->flg_export) {
2541 *pp++ = (char *) "-V";
2542 *pp++ = cur->varstr;
2545 #if ENABLE_HUSH_FUNCTIONS
2546 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2547 *pp++ = (char *) "-F";
2548 *pp++ = funcp->name;
2549 *pp++ = funcp->body_as_string;
2552 /* We can pass activated traps here. Say, -Tnn:trap_string
2554 * However, POSIX says that subshells reset signals with traps
2556 * I tested bash-3.2 and it not only does that with true subshells
2557 * of the form ( list ), but with any forked children shells.
2558 * I set trap "echo W" WINCH; and then tried:
2560 * { echo 1; sleep 20; echo 2; } &
2561 * while true; do echo 1; sleep 20; echo 2; break; done &
2562 * true | { echo 1; sleep 20; echo 2; } | cat
2564 * In all these cases sending SIGWINCH to the child shell
2565 * did not run the trap. If I add trap "echo V" WINCH;
2566 * _inside_ group (just before echo 1), it works.
2568 * I conclude it means we don't need to pass active traps here.
2569 * exec syscall below resets them to SIG_DFL for us.
2571 *pp++ = (char *) "-c";
2576 /* *pp = NULL; - is already there */
2580 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2581 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2582 execve(bb_busybox_exec_path, argv, pp);
2583 /* Fallback. Useful for init=/bin/hush usage etc */
2584 if (argv[0][0] == '/')
2585 execve(argv[0], argv, pp);
2586 xfunc_error_retval = 127;
2587 bb_error_msg_and_die("can't re-execute the shell");
2589 #endif /* !BB_MMU */
2592 static void setup_heredoc(struct redir_struct *redir)
2594 struct fd_pair pair;
2597 /* the _body_ of heredoc (misleading field name) */
2598 const char *heredoc = redir->rd_filename;
2605 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2606 expanded = expand_pseudo_dquoted(heredoc);
2610 len = strlen(heredoc);
2612 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2614 xmove_fd(pair.rd, redir->rd_fd);
2616 /* Try writing without forking. Newer kernels have
2617 * dynamically growing pipes. Must use non-blocking write! */
2620 written = write(pair.wr, heredoc, len);
2631 ndelay_off(pair.wr);
2633 /* Okay, pipe buffer was not big enough */
2634 /* Note: we must not create a stray child (bastard? :)
2635 * for the unsuspecting parent process. Child creates a grandchild
2636 * and exits before parent execs the process which consumes heredoc
2637 * (that exec happens after we return from this function) */
2643 bb_perror_msg_and_die("vfork");
2646 disable_restore_tty_pgrp_on_exit();
2647 pid = BB_MMU ? fork() : vfork();
2649 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2653 close(redir->rd_fd); /* read side of the pipe */
2655 full_write(pair.wr, heredoc, len); /* may loop or block */
2658 /* Delegate blocking writes to another process */
2659 xmove_fd(pair.wr, STDOUT_FILENO);
2660 re_execute_shell(&to_free, heredoc, NULL, NULL);
2664 enable_restore_tty_pgrp_on_exit();
2670 wait(NULL); /* wait till child has died */
2673 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2674 * and stderr if they are redirected. */
2675 static int setup_redirects(struct command *prog, int squirrel[])
2678 struct redir_struct *redir;
2680 for (redir = prog->redirects; redir; redir = redir->next) {
2681 if (redir->rd_type == REDIRECT_HEREDOC2) {
2682 /* rd_fd<<HERE case */
2683 if (squirrel && redir->rd_fd < 3
2684 && squirrel[redir->rd_fd] < 0
2686 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2688 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2690 debug_printf_parse("set heredoc '%s'\n",
2691 redir->rd_filename);
2692 setup_heredoc(redir);
2696 if (redir->rd_dup == REDIRFD_TO_FILE) {
2697 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2699 if (redir->rd_filename == NULL) {
2700 /* Something went wrong in the parse.
2701 * Pretend it didn't happen */
2702 bb_error_msg("bug in redirect parse");
2705 mode = redir_table[redir->rd_type].mode;
2706 p = expand_string_to_string(redir->rd_filename);
2707 openfd = open_or_warn(p, mode);
2710 /* this could get lost if stderr has been redirected, but
2711 * bash and ash both lose it as well (though zsh doesn't!) */
2712 //what the above comment tries to say?
2716 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2717 openfd = redir->rd_dup;
2720 if (openfd != redir->rd_fd) {
2721 if (squirrel && redir->rd_fd < 3
2722 && squirrel[redir->rd_fd] < 0
2724 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2726 if (openfd == REDIRFD_CLOSE) {
2727 /* "n>-" means "close me" */
2728 close(redir->rd_fd);
2730 xdup2(openfd, redir->rd_fd);
2731 if (redir->rd_dup == REDIRFD_TO_FILE)
2739 static void restore_redirects(int squirrel[])
2742 for (i = 0; i < 3; i++) {
2745 /* We simply die on error */
2752 static void free_pipe_list(struct pipe *head);
2754 /* Return code is the exit status of the pipe */
2755 static void free_pipe(struct pipe *pi)
2758 struct command *command;
2759 struct redir_struct *r, *rnext;
2762 if (pi->stopped_cmds > 0) /* why? */
2764 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2765 for (i = 0; i < pi->num_cmds; i++) {
2766 command = &pi->cmds[i];
2767 debug_printf_clean(" command %d:\n", i);
2768 if (command->argv) {
2769 for (a = 0, p = command->argv; *p; a++, p++) {
2770 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2772 free_strings(command->argv);
2773 command->argv = NULL;
2775 /* not "else if": on syntax error, we may have both! */
2776 if (command->group) {
2777 debug_printf_clean(" begin group (grp_type:%d)\n",
2779 free_pipe_list(command->group);
2780 debug_printf_clean(" end group\n");
2781 command->group = NULL;
2783 /* else is crucial here.
2784 * If group != NULL, child_func is meaningless */
2785 #if ENABLE_HUSH_FUNCTIONS
2786 else if (command->child_func) {
2787 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2788 command->child_func->parent_cmd = NULL;
2792 free(command->group_as_string);
2793 command->group_as_string = NULL;
2795 for (r = command->redirects; r; r = rnext) {
2796 debug_printf_clean(" redirect %d%s",
2797 r->rd_fd, redir_table[r->rd_type].descrip);
2798 /* guard against the case >$FOO, where foo is unset or blank */
2799 if (r->rd_filename) {
2800 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2801 free(r->rd_filename);
2802 r->rd_filename = NULL;
2804 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2808 command->redirects = NULL;
2810 free(pi->cmds); /* children are an array, they get freed all at once */
2818 static void free_pipe_list(struct pipe *head)
2820 struct pipe *pi, *next;
2822 for (pi = head; pi; pi = next) {
2824 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2827 debug_printf_clean("pipe followup code %d\n", pi->followup);
2829 /*pi->next = NULL;*/
2835 static int run_list(struct pipe *pi);
2837 #define parse_stream(pstring, input, end_trigger) \
2838 parse_stream(input, end_trigger)
2840 static struct pipe *parse_stream(char **pstring,
2841 struct in_str *input,
2843 static void parse_and_run_string(const char *s);
2846 static const struct built_in_command* find_builtin(const char *name)
2848 const struct built_in_command *x;
2849 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2850 if (strcmp(name, x->cmd) != 0)
2852 debug_printf_exec("found builtin '%s'\n", name);
2858 #if ENABLE_HUSH_FUNCTIONS
2859 static const struct function *find_function(const char *name)
2861 const struct function *funcp = G.top_func;
2863 if (strcmp(name, funcp->name) == 0) {
2866 funcp = funcp->next;
2869 debug_printf_exec("found function '%s'\n", name);
2873 /* Note: takes ownership on name ptr */
2874 static struct function *new_function(char *name)
2876 struct function *funcp;
2877 struct function **funcpp = &G.top_func;
2879 while ((funcp = *funcpp) != NULL) {
2880 struct command *cmd;
2882 if (strcmp(funcp->name, name) != 0) {
2883 funcpp = &funcp->next;
2887 cmd = funcp->parent_cmd;
2888 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2890 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2892 /* Note: if !funcp->body, do not free body_as_string!
2893 * This is a special case of "-F name body" function:
2894 * body_as_string was not malloced! */
2896 free_pipe_list(funcp->body);
2898 free(funcp->body_as_string);
2902 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2903 cmd->argv[0] = funcp->name;
2904 cmd->group = funcp->body;
2906 cmd->group_as_string = funcp->body_as_string;
2911 debug_printf_exec("remembering new function '%s'\n", name);
2912 funcp = *funcpp = xzalloc(sizeof(*funcp));
2913 /*funcp->next = NULL;*/
2919 static void unset_func(const char *name)
2921 struct function *funcp;
2922 struct function **funcpp = &G.top_func;
2924 while ((funcp = *funcpp) != NULL) {
2925 if (strcmp(funcp->name, name) == 0) {
2926 *funcpp = funcp->next;
2927 /* funcp is unlinked now, deleting it */
2929 /* Note: if !funcp->body, do not free body_as_string!
2930 * This is a special case of "-F name body" function:
2931 * body_as_string was not malloced! */
2933 free_pipe_list(funcp->body);
2935 free(funcp->body_as_string);
2941 funcpp = &funcp->next;
2946 #define exec_function(nommu_save, funcp, argv) \
2947 exec_function(funcp, argv)
2949 static void exec_function(nommu_save_t *nommu_save,
2950 const struct function *funcp,
2951 char **argv) NORETURN;
2952 static void exec_function(nommu_save_t *nommu_save,
2953 const struct function *funcp,
2959 argv[0] = G.global_argv[0];
2960 G.global_argv = argv;
2964 /* On MMU, funcp->body is always non-NULL */
2965 n = run_list(funcp->body);
2969 re_execute_shell(&nommu_save->argv_from_re_execing,
2970 funcp->body_as_string,
2976 static int run_function(const struct function *funcp, char **argv)
2982 save_and_replace_G_args(&sv, argv);
2983 /* "we are in function, ok to use return" */
2984 sv_flg = G.flag_return_in_progress;
2985 G.flag_return_in_progress = -1;
2987 /* On MMU, funcp->body is always non-NULL */
2990 /* Function defined by -F */
2991 parse_and_run_string(funcp->body_as_string);
2992 rc = G.last_exitcode;
2996 rc = run_list(funcp->body);
2999 G.flag_return_in_progress = sv_flg;
3000 restore_G_args(&sv, argv);
3004 #endif /* ENABLE_HUSH_FUNCTIONS */
3008 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3009 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3010 #define pseudo_exec(nommu_save, command, argv_expanded) \
3011 pseudo_exec(command, argv_expanded)
3014 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3016 * Don't exit() here. If you don't exec, use _exit instead.
3017 * The at_exit handlers apparently confuse the calling process,
3018 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3019 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3020 char **argv, int assignment_cnt,
3021 char **argv_expanded) NORETURN;
3022 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3023 char **argv, int assignment_cnt,
3024 char **argv_expanded)
3028 /* Case when we are here: ... | var=val | ... */
3029 if (!argv[assignment_cnt])
3030 _exit(EXIT_SUCCESS);
3032 new_env = expand_assignments(argv, assignment_cnt);
3034 set_vars_and_save_old(new_env);
3035 free(new_env); /* optional */
3036 /* we can also destroy set_vars_and_save_old's return value,
3039 nommu_save->new_env = new_env;
3040 nommu_save->old_vars = set_vars_and_save_old(new_env);
3042 if (argv_expanded) {
3043 argv = argv_expanded;
3045 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3047 nommu_save->argv = argv;
3051 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3052 if (strchr(argv[0], '/') != NULL)
3056 /* On NOMMU, we must never block!
3057 * Example: { sleep 99999 | read line } & echo Ok
3058 * read builtin will block on read syscall, leaving parent blocked
3059 * in vfork. Therefore we can't do this:
3062 /* Check if the command matches any of the builtins.
3063 * Depending on context, this might be redundant. But it's
3064 * easier to waste a few CPU cycles than it is to figure out
3065 * if this is one of those cases.
3069 const struct built_in_command *x = find_builtin(argv[0]);
3071 rcode = x->function(argv);
3077 #if ENABLE_HUSH_FUNCTIONS
3078 /* Check if the command matches any functions */
3080 const struct function *funcp = find_function(argv[0]);
3082 exec_function(nommu_save, funcp, argv);
3087 #if ENABLE_FEATURE_SH_STANDALONE
3088 /* Check if the command matches any busybox applets */
3090 int a = find_applet_by_name(argv[0]);
3092 # if BB_MMU /* see above why on NOMMU it is not allowed */
3093 if (APPLET_IS_NOEXEC(a)) {
3094 debug_printf_exec("running applet '%s'\n", argv[0]);
3095 run_applet_no_and_exit(a, argv);
3098 /* Re-exec ourselves */
3099 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3100 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3101 execv(bb_busybox_exec_path, argv);
3102 /* If they called chroot or otherwise made the binary no longer
3103 * executable, fall through */
3108 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3111 debug_printf_exec("execing '%s'\n", argv[0]);
3112 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3113 execvp(argv[0], argv);
3114 bb_perror_msg("can't execute '%s'", argv[0]);
3115 _exit(EXIT_FAILURE);
3118 /* Called after [v]fork() in run_pipe
3120 static void pseudo_exec(nommu_save_t *nommu_save,
3121 struct command *command,
3122 char **argv_expanded) NORETURN;
3123 static void pseudo_exec(nommu_save_t *nommu_save,
3124 struct command *command,
3125 char **argv_expanded)
3127 if (command->argv) {
3128 pseudo_exec_argv(nommu_save, command->argv,
3129 command->assignment_cnt, argv_expanded);
3132 if (command->group) {
3133 /* Cases when we are here:
3136 * ... | ( list ) | ...
3137 * ... | { list } | ...
3141 debug_printf_exec("pseudo_exec: run_list\n");
3142 reset_traps_to_defaults();
3143 rcode = run_list(command->group);
3144 /* OK to leak memory by not calling free_pipe_list,
3145 * since this process is about to exit */
3148 re_execute_shell(&nommu_save->argv_from_re_execing,
3149 command->group_as_string,
3155 /* Case when we are here: ... | >file */
3156 debug_printf_exec("pseudo_exec'ed null command\n");
3157 _exit(EXIT_SUCCESS);
3161 static const char *get_cmdtext(struct pipe *pi)
3167 /* This is subtle. ->cmdtext is created only on first backgrounding.
3168 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3169 * On subsequent bg argv is trashed, but we won't use it */
3172 argv = pi->cmds[0].argv;
3173 if (!argv || !argv[0]) {
3174 pi->cmdtext = xzalloc(1);
3180 len += strlen(*argv) + 1;
3184 argv = pi->cmds[0].argv;
3186 len = strlen(*argv);
3187 memcpy(p, *argv, len);
3195 static void insert_bg_job(struct pipe *pi)
3197 struct pipe *job, **jobp;
3200 /* Linear search for the ID of the job to use */
3202 for (job = G.job_list; job; job = job->next)
3203 if (job->jobid >= pi->jobid)
3204 pi->jobid = job->jobid + 1;
3206 /* Add job to the list of running jobs */
3208 while ((job = *jobp) != NULL)
3210 job = *jobp = xmalloc(sizeof(*job));
3212 *job = *pi; /* physical copy */
3214 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3215 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3216 for (i = 0; i < pi->num_cmds; i++) {
3217 job->cmds[i].pid = pi->cmds[i].pid;
3218 /* all other fields are not used and stay zero */
3220 job->cmdtext = xstrdup(get_cmdtext(pi));
3222 if (G_interactive_fd)
3223 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3224 /* Last command's pid goes to $! */
3225 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3226 G.last_jobid = job->jobid;
3229 static void remove_bg_job(struct pipe *pi)
3231 struct pipe *prev_pipe;
3233 if (pi == G.job_list) {
3234 G.job_list = pi->next;
3236 prev_pipe = G.job_list;
3237 while (prev_pipe->next != pi)
3238 prev_pipe = prev_pipe->next;
3239 prev_pipe->next = pi->next;
3242 G.last_jobid = G.job_list->jobid;
3247 /* Remove a backgrounded job */
3248 static void delete_finished_bg_job(struct pipe *pi)
3251 pi->stopped_cmds = 0;
3257 /* Check to see if any processes have exited -- if they
3258 * have, figure out why and see if a job has completed */
3259 static int checkjobs(struct pipe* fg_pipe)
3269 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3272 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3273 // /* avoid doing syscall, nothing there anyway */
3276 attributes = WUNTRACED;
3277 if (fg_pipe == NULL)
3278 attributes |= WNOHANG;
3280 /* Do we do this right?
3281 * bash-3.00# sleep 20 | false
3283 * [3]+ Stopped sleep 20 | false
3284 * bash-3.00# echo $?
3285 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3286 * [hush 1.14.0: yes we do it right]
3293 // i = G.count_SIGCHLD;
3294 childpid = waitpid(-1, &status, attributes);
3295 if (childpid <= 0) {
3296 if (childpid && errno != ECHILD)
3297 bb_perror_msg("waitpid");
3298 // else /* Until next SIGCHLD, waitpid's are useless */
3299 // G.handled_SIGCHLD = i;
3302 dead = WIFEXITED(status) || WIFSIGNALED(status);
3305 if (WIFSTOPPED(status))
3306 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3307 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3308 if (WIFSIGNALED(status))
3309 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3310 childpid, WTERMSIG(status), WEXITSTATUS(status));
3311 if (WIFEXITED(status))
3312 debug_printf_jobs("pid %d exited, exitcode %d\n",
3313 childpid, WEXITSTATUS(status));
3315 /* Were we asked to wait for fg pipe? */
3317 for (i = 0; i < fg_pipe->num_cmds; i++) {
3318 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3319 if (fg_pipe->cmds[i].pid != childpid)
3322 fg_pipe->cmds[i].pid = 0;
3323 fg_pipe->alive_cmds--;
3324 if (i == fg_pipe->num_cmds - 1) {
3325 /* last process gives overall exitstatus */
3326 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3327 rcode = WEXITSTATUS(status);
3328 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3329 /* bash prints killing signal's name for *last*
3330 * process in pipe (prints just newline for SIGINT).
3331 * Mimic this. Example: "sleep 5" + ^\
3333 if (WIFSIGNALED(status)) {
3334 int sig = WTERMSIG(status);
3335 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3339 fg_pipe->cmds[i].is_stopped = 1;
3340 fg_pipe->stopped_cmds++;
3342 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3343 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3344 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3345 /* All processes in fg pipe have exited or stopped */
3346 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3347 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3348 * and "killall -STOP cat" */
3349 if (G_interactive_fd) {
3351 if (fg_pipe->alive_cmds)
3352 insert_bg_job(fg_pipe);
3357 /* There are still running processes in the fg pipe */
3358 goto wait_more; /* do waitpid again */
3360 /* it wasnt fg_pipe, look for process in bg pipes */
3364 /* We asked to wait for bg or orphaned children */
3365 /* No need to remember exitcode in this case */
3366 for (pi = G.job_list; pi; pi = pi->next) {
3367 for (i = 0; i < pi->num_cmds; i++) {
3368 if (pi->cmds[i].pid == childpid)
3369 goto found_pi_and_prognum;
3372 /* Happens when shell is used as init process (init=/bin/sh) */
3373 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3374 continue; /* do waitpid again */
3376 found_pi_and_prognum:
3379 pi->cmds[i].pid = 0;
3381 if (!pi->alive_cmds) {
3382 if (G_interactive_fd)
3383 printf(JOB_STATUS_FORMAT, pi->jobid,
3384 "Done", pi->cmdtext);
3385 delete_finished_bg_job(pi);
3389 pi->cmds[i].is_stopped = 1;
3393 } /* while (waitpid succeeds)... */
3399 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3402 int rcode = checkjobs(fg_pipe);
3403 if (G.saved_tty_pgrp) {
3404 /* Job finished, move the shell to the foreground */
3405 p = getpgrp(); /* our process group id */
3406 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3407 tcsetpgrp(G_interactive_fd, p);
3413 /* Start all the jobs, but don't wait for anything to finish.
3416 * Return code is normally -1, when the caller has to wait for children
3417 * to finish to determine the exit status of the pipe. If the pipe
3418 * is a simple builtin command, however, the action is done by the
3419 * time run_pipe returns, and the exit code is provided as the
3422 * Returns -1 only if started some children. IOW: we have to
3423 * mask out retvals of builtins etc with 0xff!
3425 * The only case when we do not need to [v]fork is when the pipe
3426 * is single, non-backgrounded, non-subshell command. Examples:
3427 * cmd ; ... { list } ; ...
3428 * cmd && ... { list } && ...
3429 * cmd || ... { list } || ...
3430 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3431 * or (if SH_STANDALONE) an applet, and we can run the { list }
3432 * with run_list. If it isn't one of these, we fork and exec cmd.
3434 * Cases when we must fork:
3435 * non-single: cmd | cmd
3436 * backgrounded: cmd & { list } &
3437 * subshell: ( list ) [&]
3439 static int run_pipe(struct pipe *pi)
3441 static const char *const null_ptr = NULL;
3444 struct command *command;
3445 char **argv_expanded;
3448 /* it is not always needed, but we aim to smaller code */
3449 int squirrel[] = { -1, -1, -1 };
3452 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3455 IF_HUSH_JOB(pi->pgrp = -1;)
3456 pi->stopped_cmds = 0;
3457 command = &(pi->cmds[0]);
3458 argv_expanded = NULL;
3460 if (pi->num_cmds != 1
3461 || pi->followup == PIPE_BG
3462 || command->grp_type == GRP_SUBSHELL
3469 debug_printf_exec(": group:%p argv:'%s'\n",
3470 command->group, command->argv ? command->argv[0] : "NONE");
3472 if (command->group) {
3473 #if ENABLE_HUSH_FUNCTIONS
3474 if (command->grp_type == GRP_FUNCTION) {
3475 /* "executing" func () { list } */
3476 struct function *funcp;
3478 funcp = new_function(command->argv[0]);
3479 /* funcp->name is already set to argv[0] */
3480 funcp->body = command->group;
3482 funcp->body_as_string = command->group_as_string;
3483 command->group_as_string = NULL;
3485 command->group = NULL;
3486 command->argv[0] = NULL;
3487 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3488 funcp->parent_cmd = command;
3489 command->child_func = funcp;
3491 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3493 return EXIT_SUCCESS;
3497 debug_printf("non-subshell group\n");
3498 rcode = 1; /* exitcode if redir failed */
3499 if (setup_redirects(command, squirrel) == 0) {
3500 debug_printf_exec(": run_list\n");
3501 rcode = run_list(command->group) & 0xff;
3503 restore_redirects(squirrel);
3504 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3506 debug_printf_exec("run_pipe: return %d\n", rcode);
3510 argv = command->argv ? command->argv : (char **) &null_ptr;
3512 const struct built_in_command *x;
3513 #if ENABLE_HUSH_FUNCTIONS
3514 const struct function *funcp;
3518 char **new_env = NULL;
3519 struct variable *old_vars = NULL;
3521 if (argv[command->assignment_cnt] == NULL) {
3522 /* Assignments, but no command */
3523 /* Ensure redirects take effect. Try "a=t >file" */
3524 rcode = setup_redirects(command, squirrel);
3525 restore_redirects(squirrel);
3526 /* Set shell variables */
3528 p = expand_string_to_string(*argv);
3529 debug_printf_exec("set shell var:'%s'->'%s'\n",
3531 set_local_var(p, 0, 0);
3534 /* Do we need to flag set_local_var() errors?
3535 * "assignment to readonly var" and "putenv error"
3537 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3539 debug_printf_exec("run_pipe: return %d\n", rcode);
3543 /* Expand the rest into (possibly) many strings each */
3544 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3546 x = find_builtin(argv_expanded[0]);
3547 #if ENABLE_HUSH_FUNCTIONS
3550 funcp = find_function(argv_expanded[0]);
3554 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3555 debug_printf("exec with redirects only\n");
3556 rcode = setup_redirects(command, NULL);
3557 goto clean_up_and_ret1;
3560 /* setup_redirects acts on file descriptors, not FILEs.
3561 * This is perfect for work that comes after exec().
3562 * Is it really safe for inline use? Experimentally,
3563 * things seem to work. */
3564 rcode = setup_redirects(command, squirrel);
3566 new_env = expand_assignments(argv, command->assignment_cnt);
3567 old_vars = set_vars_and_save_old(new_env);
3569 debug_printf_exec(": builtin '%s' '%s'...\n",
3570 x->cmd, argv_expanded[1]);
3571 rcode = x->function(argv_expanded) & 0xff;
3574 #if ENABLE_HUSH_FUNCTIONS
3576 debug_printf_exec(": function '%s' '%s'...\n",
3577 funcp->name, argv_expanded[1]);
3578 rcode = run_function(funcp, argv_expanded) & 0xff;
3582 #if ENABLE_FEATURE_SH_STANDALONE
3585 restore_redirects(squirrel);
3586 unset_vars(new_env);
3589 free(argv_expanded);
3590 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3592 debug_printf_exec("run_pipe return %d\n", rcode);
3596 #if ENABLE_FEATURE_SH_STANDALONE
3597 i = find_applet_by_name(argv_expanded[0]);
3598 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3599 rcode = setup_redirects(command, squirrel);
3601 new_env = expand_assignments(argv, command->assignment_cnt);
3602 old_vars = set_vars_and_save_old(new_env);
3603 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3604 argv_expanded[0], argv_expanded[1]);
3605 rcode = run_nofork_applet(i, argv_expanded);
3607 goto clean_up_and_ret;
3610 /* It is neither builtin nor applet. We must fork. */
3614 /* NB: argv_expanded may already be created, and that
3615 * might include `cmd` runs! Do not rerun it! We *must*
3616 * use argv_expanded if it's non-NULL */
3618 /* Going to fork a child per each pipe member */
3622 for (i = 0; i < pi->num_cmds; i++) {
3623 struct fd_pair pipefds;
3625 volatile nommu_save_t nommu_save;
3626 nommu_save.new_env = NULL;
3627 nommu_save.old_vars = NULL;
3628 nommu_save.argv = NULL;
3629 nommu_save.argv_from_re_execing = NULL;
3631 command = &(pi->cmds[i]);
3632 if (command->argv) {
3633 debug_printf_exec(": pipe member '%s' '%s'...\n",
3634 command->argv[0], command->argv[1]);
3636 debug_printf_exec(": pipe member with no argv\n");
3639 /* pipes are inserted between pairs of commands */
3642 if ((i + 1) < pi->num_cmds)
3643 xpiped_pair(pipefds);
3645 command->pid = BB_MMU ? fork() : vfork();
3646 if (!command->pid) { /* child */
3648 disable_restore_tty_pgrp_on_exit();
3650 /* Every child adds itself to new process group
3651 * with pgid == pid_of_first_child_in_pipe */
3652 if (G.run_list_level == 1 && G_interactive_fd) {
3655 if (pgrp < 0) /* true for 1st process only */
3657 if (setpgid(0, pgrp) == 0
3658 && pi->followup != PIPE_BG
3659 && G.saved_tty_pgrp /* we have ctty */
3661 /* We do it in *every* child, not just first,
3663 tcsetpgrp(G_interactive_fd, pgrp);
3667 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
3668 /* 1st cmd in backgrounded pipe
3669 * should have its stdin /dev/null'ed */
3671 if (open(bb_dev_null, O_RDONLY))
3672 xopen("/", O_RDONLY);
3674 xmove_fd(nextin, 0);
3676 xmove_fd(pipefds.wr, 1);
3679 /* Like bash, explicit redirects override pipes,
3680 * and the pipe fd is available for dup'ing. */
3681 if (setup_redirects(command, NULL))
3684 /* Restore default handlers just prior to exec */
3685 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3687 /* Stores to nommu_save list of env vars putenv'ed
3688 * (NOMMU, on MMU we don't need that) */
3689 /* cast away volatility... */
3690 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3691 /* pseudo_exec() does not return */
3694 /* parent or error */
3695 enable_restore_tty_pgrp_on_exit();
3697 /* Clean up after vforked child */
3698 free(nommu_save.argv);
3699 free(nommu_save.argv_from_re_execing);
3700 unset_vars(nommu_save.new_env);
3701 add_vars(nommu_save.old_vars);
3703 free(argv_expanded);
3704 argv_expanded = NULL;
3705 if (command->pid < 0) { /* [v]fork failed */
3706 /* Clearly indicate, was it fork or vfork */
3707 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3711 /* Second and next children need to know pid of first one */
3713 pi->pgrp = command->pid;
3719 if ((i + 1) < pi->num_cmds)
3721 /* Pass read (output) pipe end to next iteration */
3722 nextin = pipefds.rd;
3725 if (!pi->alive_cmds) {
3727 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3732 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3736 #ifndef debug_print_tree
3737 static void debug_print_tree(struct pipe *pi, int lvl)
3739 static const char *const PIPE[] = {
3745 static const char *RES[] = {
3746 [RES_NONE ] = "NONE" ,
3749 [RES_THEN ] = "THEN" ,
3750 [RES_ELIF ] = "ELIF" ,
3751 [RES_ELSE ] = "ELSE" ,
3754 #if ENABLE_HUSH_LOOPS
3755 [RES_FOR ] = "FOR" ,
3756 [RES_WHILE] = "WHILE",
3757 [RES_UNTIL] = "UNTIL",
3759 [RES_DONE ] = "DONE" ,
3761 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3764 #if ENABLE_HUSH_CASE
3765 [RES_CASE ] = "CASE" ,
3766 [RES_MATCH] = "MATCH",
3767 [RES_CASEI] = "CASEI",
3768 [RES_ESAC ] = "ESAC" ,
3770 [RES_XXXX ] = "XXXX" ,
3771 [RES_SNTX ] = "SNTX" ,
3773 static const char *const GRPTYPE[] = {
3776 #if ENABLE_HUSH_FUNCTIONS
3785 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3786 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3788 while (prn < pi->num_cmds) {
3789 struct command *command = &pi->cmds[prn];
3790 char **argv = command->argv;
3792 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3794 command->assignment_cnt);
3795 if (command->group) {
3796 fprintf(stderr, " group %s: (argv=%p)\n",
3797 GRPTYPE[command->grp_type],
3799 debug_print_tree(command->group, lvl+1);
3803 if (argv) while (*argv) {
3804 fprintf(stderr, " '%s'", *argv);
3807 fprintf(stderr, "\n");
3816 /* NB: called by pseudo_exec, and therefore must not modify any
3817 * global data until exec/_exit (we can be a child after vfork!) */
3818 static int run_list(struct pipe *pi)
3820 #if ENABLE_HUSH_CASE
3821 char *case_word = NULL;
3823 #if ENABLE_HUSH_LOOPS
3824 struct pipe *loop_top = NULL;
3825 char *for_varname = NULL;
3826 char **for_lcur = NULL;
3827 char **for_list = NULL;
3829 smallint last_followup;
3831 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3832 smalluint cond_code = 0;
3834 enum { cond_code = 0 };
3837 smallint rword; /* enum reserved_style */
3838 smallint last_rword; /* ditto */
3841 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3844 #if ENABLE_HUSH_LOOPS
3845 /* Check syntax for "for" */
3846 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3847 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3849 /* current word is FOR or IN (BOLD in comments below) */
3850 if (cpipe->next == NULL) {
3851 syntax_error("malformed for");
3853 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3856 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3857 if (cpipe->next->res_word == RES_DO)
3859 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3860 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3861 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3863 syntax_error("malformed for");
3865 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3871 /* Past this point, all code paths should jump to ret: label
3872 * in order to return, no direct "return" statements please.
3873 * This helps to ensure that no memory is leaked. */
3881 last_rword = RES_XXXX;
3883 last_followup = PIPE_SEQ;
3884 rcode = G.last_exitcode;
3886 /* Go through list of pipes, (maybe) executing them. */
3887 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3891 IF_HAS_KEYWORDS(rword = pi->res_word;)
3892 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3893 rword, cond_code, last_rword);
3894 #if ENABLE_HUSH_LOOPS
3895 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3896 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3898 /* start of a loop: remember where loop starts */
3903 /* Still in the same "if...", "then..." or "do..." branch? */
3904 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3905 if ((rcode == 0 && last_followup == PIPE_OR)
3906 || (rcode != 0 && last_followup == PIPE_AND)
3908 /* It is "<true> || CMD" or "<false> && CMD"
3909 * and we should not execute CMD */
3910 debug_printf_exec("skipped cmd because of || or &&\n");
3911 last_followup = pi->followup;
3915 last_followup = pi->followup;
3916 IF_HAS_KEYWORDS(last_rword = rword;)
3919 if (rword == RES_THEN) {
3920 /* if false; then ... fi has exitcode 0! */
3921 G.last_exitcode = rcode = EXIT_SUCCESS;
3922 /* "if <false> THEN cmd": skip cmd */
3926 if (rword == RES_ELSE || rword == RES_ELIF) {
3927 /* "if <true> then ... ELSE/ELIF cmd":
3928 * skip cmd and all following ones */
3933 #if ENABLE_HUSH_LOOPS
3934 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3936 /* first loop through for */
3938 static const char encoded_dollar_at[] ALIGN1 = {
3939 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3940 }; /* encoded representation of "$@" */
3941 static const char *const encoded_dollar_at_argv[] = {
3942 encoded_dollar_at, NULL
3943 }; /* argv list with one element: "$@" */
3946 vals = (char**)encoded_dollar_at_argv;
3947 if (pi->next->res_word == RES_IN) {
3948 /* if no variable values after "in" we skip "for" */
3949 if (!pi->next->cmds[0].argv) {
3950 G.last_exitcode = rcode = EXIT_SUCCESS;
3951 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3954 vals = pi->next->cmds[0].argv;
3955 } /* else: "for var; do..." -> assume "$@" list */
3956 /* create list of variable values */
3957 debug_print_strings("for_list made from", vals);
3958 for_list = expand_strvec_to_strvec(vals);
3959 for_lcur = for_list;
3960 debug_print_strings("for_list", for_list);
3961 for_varname = pi->cmds[0].argv[0];
3962 pi->cmds[0].argv[0] = NULL;
3964 free(pi->cmds[0].argv[0]);
3966 /* "for" loop is over, clean up */
3970 pi->cmds[0].argv[0] = for_varname;
3973 /* Insert next value from for_lcur */
3974 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3975 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3976 pi->cmds[0].assignment_cnt = 1;
3978 if (rword == RES_IN) {
3979 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3981 if (rword == RES_DONE) {
3982 continue; /* "done" has no cmds too */
3985 #if ENABLE_HUSH_CASE
3986 if (rword == RES_CASE) {
3987 case_word = expand_strvec_to_string(pi->cmds->argv);
3990 if (rword == RES_MATCH) {
3993 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3995 /* all prev words didn't match, does this one match? */
3996 argv = pi->cmds->argv;
3998 char *pattern = expand_string_to_string(*argv);
3999 /* TODO: which FNM_xxx flags to use? */
4000 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4002 if (cond_code == 0) { /* match! we will execute this branch */
4003 free(case_word); /* make future "word)" stop */
4011 if (rword == RES_CASEI) { /* inside of a case branch */
4013 continue; /* not matched yet, skip this pipe */
4016 /* Just pressing <enter> in shell should check for jobs.
4017 * OTOH, in non-interactive shell this is useless
4018 * and only leads to extra job checks */
4019 if (pi->num_cmds == 0) {
4020 if (G_interactive_fd)
4021 goto check_jobs_and_continue;
4025 /* After analyzing all keywords and conditions, we decided
4026 * to execute this pipe. NB: have to do checkjobs(NULL)
4027 * after run_pipe to collect any background children,
4028 * even if list execution is to be stopped. */
4029 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4032 #if ENABLE_HUSH_LOOPS
4033 G.flag_break_continue = 0;
4035 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4037 /* We ran a builtin, function, or group.
4038 * rcode is already known
4039 * and we don't need to wait for anything. */
4040 G.last_exitcode = rcode;
4041 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4042 check_and_run_traps(0);
4043 #if ENABLE_HUSH_LOOPS
4044 /* Was it "break" or "continue"? */
4045 if (G.flag_break_continue) {
4046 smallint fbc = G.flag_break_continue;
4047 /* We might fall into outer *loop*,
4048 * don't want to break it too */
4050 G.depth_break_continue--;
4051 if (G.depth_break_continue == 0)
4052 G.flag_break_continue = 0;
4053 /* else: e.g. "continue 2" should *break* once, *then* continue */
4054 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4055 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4056 goto check_jobs_and_break;
4057 /* "continue": simulate end of loop */
4062 #if ENABLE_HUSH_FUNCTIONS
4063 if (G.flag_return_in_progress == 1)
4064 goto check_jobs_and_break;
4066 } else if (pi->followup == PIPE_BG) {
4067 /* What does bash do with attempts to background builtins? */
4068 /* even bash 3.2 doesn't do that well with nested bg:
4069 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4070 * I'm NOT treating inner &'s as jobs */
4071 check_and_run_traps(0);
4073 if (G.run_list_level == 1)
4076 G.last_exitcode = rcode = EXIT_SUCCESS;
4077 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4080 if (G.run_list_level == 1 && G_interactive_fd) {
4081 /* Waits for completion, then fg's main shell */
4082 rcode = checkjobs_and_fg_shell(pi);
4083 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4084 check_and_run_traps(0);
4087 { /* This one just waits for completion */
4088 rcode = checkjobs(pi);
4089 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4090 check_and_run_traps(0);
4092 G.last_exitcode = rcode;
4096 /* Analyze how result affects subsequent commands */
4098 if (rword == RES_IF || rword == RES_ELIF)
4101 #if ENABLE_HUSH_LOOPS
4102 /* Beware of "while false; true; do ..."! */
4103 if (pi->next && pi->next->res_word == RES_DO) {
4104 if (rword == RES_WHILE) {
4106 /* "while false; do...done" - exitcode 0 */
4107 G.last_exitcode = rcode = EXIT_SUCCESS;
4108 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4109 goto check_jobs_and_break;
4112 if (rword == RES_UNTIL) {
4114 debug_printf_exec(": until expr is true: breaking\n");
4115 check_jobs_and_break:
4123 check_jobs_and_continue:
4130 #if ENABLE_HUSH_LOOPS
4135 #if ENABLE_HUSH_CASE
4139 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4143 /* Select which version we will use */
4144 static int run_and_free_list(struct pipe *pi)
4147 debug_printf_exec("run_and_free_list entered\n");
4149 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4150 rcode = run_list(pi);
4152 /* free_pipe_list has the side effect of clearing memory.
4153 * In the long run that function can be merged with run_list,
4154 * but doing that now would hobble the debugging effort. */
4156 debug_printf_exec("run_and_free_list return %d\n", rcode);
4161 static struct pipe *new_pipe(void)
4164 pi = xzalloc(sizeof(struct pipe));
4165 /*pi->followup = 0; - deliberately invalid value */
4166 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4170 /* Command (member of a pipe) is complete, or we start a new pipe
4171 * if ctx->command is NULL.
4172 * No errors possible here.
4174 static int done_command(struct parse_context *ctx)
4176 /* The command is really already in the pipe structure, so
4177 * advance the pipe counter and make a new, null command. */
4178 struct pipe *pi = ctx->pipe;
4179 struct command *command = ctx->command;
4182 if (IS_NULL_CMD(command)) {
4183 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4187 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4188 //debug_print_tree(ctx->list_head, 20);
4190 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4193 /* Only real trickiness here is that the uncommitted
4194 * command structure is not counted in pi->num_cmds. */
4195 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4196 ctx->command = command = &pi->cmds[pi->num_cmds];
4198 memset(command, 0, sizeof(*command));
4199 return pi->num_cmds; /* used only for 0/nonzero check */
4202 static void done_pipe(struct parse_context *ctx, pipe_style type)
4206 debug_printf_parse("done_pipe entered, followup %d\n", type);
4207 /* Close previous command */
4208 not_null = done_command(ctx);
4209 ctx->pipe->followup = type;
4211 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4212 ctx->ctx_inverted = 0;
4213 ctx->pipe->res_word = ctx->ctx_res_w;
4216 /* Without this check, even just <enter> on command line generates
4217 * tree of three NOPs (!). Which is harmless but annoying.
4218 * IOW: it is safe to do it unconditionally. */
4221 || ctx->ctx_res_w == RES_FI
4223 #if ENABLE_HUSH_LOOPS
4224 || ctx->ctx_res_w == RES_DONE
4225 || ctx->ctx_res_w == RES_FOR
4226 || ctx->ctx_res_w == RES_IN
4228 #if ENABLE_HUSH_CASE
4229 || ctx->ctx_res_w == RES_ESAC
4233 debug_printf_parse("done_pipe: adding new pipe: "
4234 "not_null:%d ctx->ctx_res_w:%d\n",
4235 not_null, ctx->ctx_res_w);
4237 ctx->pipe->next = new_p;
4239 /* RES_THEN, RES_DO etc are "sticky" -
4240 * they remain set for pipes inside if/while.
4241 * This is used to control execution.
4242 * RES_FOR and RES_IN are NOT sticky (needed to support
4243 * cases where variable or value happens to match a keyword):
4245 #if ENABLE_HUSH_LOOPS
4246 if (ctx->ctx_res_w == RES_FOR
4247 || ctx->ctx_res_w == RES_IN)
4248 ctx->ctx_res_w = RES_NONE;
4250 #if ENABLE_HUSH_CASE
4251 if (ctx->ctx_res_w == RES_MATCH)
4252 ctx->ctx_res_w = RES_CASEI;
4254 ctx->command = NULL; /* trick done_command below */
4255 /* Create the memory for command, roughly:
4256 * ctx->pipe->cmds = new struct command;
4257 * ctx->command = &ctx->pipe->cmds[0];
4260 //debug_print_tree(ctx->list_head, 10);
4262 debug_printf_parse("done_pipe return\n");
4265 static void initialize_context(struct parse_context *ctx)
4267 memset(ctx, 0, sizeof(*ctx));
4268 ctx->pipe = ctx->list_head = new_pipe();
4269 /* Create the memory for command, roughly:
4270 * ctx->pipe->cmds = new struct command;
4271 * ctx->command = &ctx->pipe->cmds[0];
4276 /* If a reserved word is found and processed, parse context is modified
4277 * and 1 is returned.
4280 struct reserved_combo {
4283 unsigned char assignment_flag;
4287 FLAG_END = (1 << RES_NONE ),
4289 FLAG_IF = (1 << RES_IF ),
4290 FLAG_THEN = (1 << RES_THEN ),
4291 FLAG_ELIF = (1 << RES_ELIF ),
4292 FLAG_ELSE = (1 << RES_ELSE ),
4293 FLAG_FI = (1 << RES_FI ),
4295 #if ENABLE_HUSH_LOOPS
4296 FLAG_FOR = (1 << RES_FOR ),
4297 FLAG_WHILE = (1 << RES_WHILE),
4298 FLAG_UNTIL = (1 << RES_UNTIL),
4299 FLAG_DO = (1 << RES_DO ),
4300 FLAG_DONE = (1 << RES_DONE ),
4301 FLAG_IN = (1 << RES_IN ),
4303 #if ENABLE_HUSH_CASE
4304 FLAG_MATCH = (1 << RES_MATCH),
4305 FLAG_ESAC = (1 << RES_ESAC ),
4307 FLAG_START = (1 << RES_XXXX ),
4310 static const struct reserved_combo* match_reserved_word(o_string *word)
4312 /* Mostly a list of accepted follow-up reserved words.
4313 * FLAG_END means we are done with the sequence, and are ready
4314 * to turn the compound list into a command.
4315 * FLAG_START means the word must start a new compound list.
4317 static const struct reserved_combo reserved_list[] = {
4319 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4320 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4321 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4322 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4323 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4324 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4326 #if ENABLE_HUSH_LOOPS
4327 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4328 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4329 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4330 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4331 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4332 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4334 #if ENABLE_HUSH_CASE
4335 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4336 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4339 const struct reserved_combo *r;
4341 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4342 if (strcmp(word->data, r->literal) == 0)
4347 /* Return 0: not a keyword, 1: keyword
4349 static int reserved_word(o_string *word, struct parse_context *ctx)
4351 #if ENABLE_HUSH_CASE
4352 static const struct reserved_combo reserved_match = {
4353 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4356 const struct reserved_combo *r;
4360 r = match_reserved_word(word);
4364 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4365 #if ENABLE_HUSH_CASE
4366 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4367 /* "case word IN ..." - IN part starts first match part */
4368 r = &reserved_match;
4371 if (r->flag == 0) { /* '!' */
4372 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4373 syntax_error("! ! command");
4374 ctx->ctx_res_w = RES_SNTX;
4376 ctx->ctx_inverted = 1;
4379 if (r->flag & FLAG_START) {
4380 struct parse_context *old;
4382 old = xmalloc(sizeof(*old));
4383 debug_printf_parse("push stack %p\n", old);
4384 *old = *ctx; /* physical copy */
4385 initialize_context(ctx);
4387 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4388 syntax_error_at(word->data);
4389 ctx->ctx_res_w = RES_SNTX;
4392 /* "{...} fi" is ok. "{...} if" is not
4394 * if { echo foo; } then { echo bar; } fi */
4395 if (ctx->command->group)
4396 done_pipe(ctx, PIPE_SEQ);
4399 ctx->ctx_res_w = r->res;
4400 ctx->old_flag = r->flag;
4401 word->o_assignment = r->assignment_flag;
4403 if (ctx->old_flag & FLAG_END) {
4404 struct parse_context *old;
4406 done_pipe(ctx, PIPE_SEQ);
4407 debug_printf_parse("pop stack %p\n", ctx->stack);
4409 old->command->group = ctx->list_head;
4410 old->command->grp_type = GRP_NORMAL;
4412 o_addstr(&old->as_string, ctx->as_string.data);
4413 o_free_unsafe(&ctx->as_string);
4414 old->command->group_as_string = xstrdup(old->as_string.data);
4415 debug_printf_parse("pop, remembering as:'%s'\n",
4416 old->command->group_as_string);
4418 *ctx = *old; /* physical copy */
4425 /* Word is complete, look at it and update parsing context.
4426 * Normal return is 0. Syntax errors return 1.
4427 * Note: on return, word is reset, but not o_free'd!
4429 static int done_word(o_string *word, struct parse_context *ctx)
4431 struct command *command = ctx->command;
4433 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4434 if (word->length == 0 && word->o_quoted == 0) {
4435 debug_printf_parse("done_word return 0: true null, ignored\n");
4439 if (ctx->pending_redirect) {
4440 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4441 * only if run as "bash", not "sh" */
4442 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4444 * ...the word that follows the redirection operator
4445 * shall be subjected to tilde expansion, parameter expansion,
4446 * command substitution, arithmetic expansion, and quote
4447 * removal. Pathname expansion shall not be performed
4448 * on the word by a non-interactive shell; an interactive
4449 * shell may perform it, but shall do so only when
4450 * the expansion would result in one word."
4452 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4453 /* Cater for >\file case:
4454 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4455 * Same with heredocs:
4456 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4458 unbackslash(ctx->pending_redirect->rd_filename);
4459 /* Is it <<"HEREDOC"? */
4460 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4463 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4465 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4466 ctx->pending_redirect = NULL;
4468 /* If this word wasn't an assignment, next ones definitely
4469 * can't be assignments. Even if they look like ones. */
4470 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4471 && word->o_assignment != WORD_IS_KEYWORD
4473 word->o_assignment = NOT_ASSIGNMENT;
4475 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4476 command->assignment_cnt++;
4477 word->o_assignment = MAYBE_ASSIGNMENT;
4481 # if ENABLE_HUSH_CASE
4482 if (ctx->ctx_dsemicolon
4483 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4485 /* already done when ctx_dsemicolon was set to 1: */
4486 /* ctx->ctx_res_w = RES_MATCH; */
4487 ctx->ctx_dsemicolon = 0;
4490 if (!command->argv /* if it's the first word... */
4491 # if ENABLE_HUSH_LOOPS
4492 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4493 && ctx->ctx_res_w != RES_IN
4496 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4497 if (reserved_word(word, ctx)) {
4498 o_reset_to_empty_unquoted(word);
4499 debug_printf_parse("done_word return %d\n",
4500 (ctx->ctx_res_w == RES_SNTX));
4501 return (ctx->ctx_res_w == RES_SNTX);
4505 if (command->group) {
4506 /* "{ echo foo; } echo bar" - bad */
4507 syntax_error_at(word->data);
4508 debug_printf_parse("done_word return 1: syntax error, "
4509 "groups and arglists don't mix\n");
4512 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4513 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4514 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4515 /* (otherwise it's known to be not empty and is already safe) */
4517 /* exclude "$@" - it can expand to no word despite "" */
4518 char *p = word->data;
4519 while (p[0] == SPECIAL_VAR_SYMBOL
4520 && (p[1] & 0x7f) == '@'
4521 && p[2] == SPECIAL_VAR_SYMBOL
4525 if (p == word->data || p[0] != '\0') {
4526 /* saw no "$@", or not only "$@" but some
4527 * real text is there too */
4528 /* insert "empty variable" reference, this makes
4529 * e.g. "", $empty"" etc to not disappear */
4530 o_addchr(word, SPECIAL_VAR_SYMBOL);
4531 o_addchr(word, SPECIAL_VAR_SYMBOL);
4534 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4535 debug_print_strings("word appended to argv", command->argv);
4538 #if ENABLE_HUSH_LOOPS
4539 if (ctx->ctx_res_w == RES_FOR) {
4541 || !is_well_formed_var_name(command->argv[0], '\0')
4543 /* bash says just "not a valid identifier" */
4544 syntax_error("not a valid identifier in for");
4547 /* Force FOR to have just one word (variable name) */
4548 /* NB: basically, this makes hush see "for v in ..."
4549 * syntax as if it is "for v; in ...". FOR and IN become
4550 * two pipe structs in parse tree. */
4551 done_pipe(ctx, PIPE_SEQ);
4554 #if ENABLE_HUSH_CASE
4555 /* Force CASE to have just one word */
4556 if (ctx->ctx_res_w == RES_CASE) {
4557 done_pipe(ctx, PIPE_SEQ);
4561 o_reset_to_empty_unquoted(word);
4563 debug_printf_parse("done_word return 0\n");
4568 /* Peek ahead in the input to find out if we have a "&n" construct,
4569 * as in "2>&1", that represents duplicating a file descriptor.
4571 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4572 * REDIRFD_SYNTAX_ERR if syntax error,
4573 * REDIRFD_TO_FILE if no & was seen,
4574 * or the number found.
4577 #define parse_redir_right_fd(as_string, input) \
4578 parse_redir_right_fd(input)
4580 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4586 return REDIRFD_TO_FILE;
4588 ch = i_getch(input); /* get the & */
4589 nommu_addchr(as_string, ch);
4592 ch = i_getch(input);
4593 nommu_addchr(as_string, ch);
4594 return REDIRFD_CLOSE;
4598 while (ch != EOF && isdigit(ch)) {
4599 d = d*10 + (ch-'0');
4601 ch = i_getch(input);
4602 nommu_addchr(as_string, ch);
4607 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4609 bb_error_msg("ambiguous redirect");
4610 return REDIRFD_SYNTAX_ERR;
4613 /* Return code is 0 normal, 1 if a syntax error is detected
4615 static int parse_redirect(struct parse_context *ctx,
4618 struct in_str *input)
4620 struct command *command = ctx->command;
4621 struct redir_struct *redir;
4622 struct redir_struct **redirp;
4625 dup_num = REDIRFD_TO_FILE;
4626 if (style != REDIRECT_HEREDOC) {
4627 /* Check for a '>&1' type redirect */
4628 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4629 if (dup_num == REDIRFD_SYNTAX_ERR)
4632 int ch = i_peek(input);
4633 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4634 if (dup_num) { /* <<-... */
4635 ch = i_getch(input);
4636 nommu_addchr(&ctx->as_string, ch);
4641 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4642 int ch = i_peek(input);
4644 /* >|FILE redirect ("clobbering" >).
4645 * Since we do not support "set -o noclobber" yet,
4646 * >| and > are the same for now. Just eat |.
4648 ch = i_getch(input);
4649 nommu_addchr(&ctx->as_string, ch);
4653 /* Create a new redir_struct and append it to the linked list */
4654 redirp = &command->redirects;
4655 while ((redir = *redirp) != NULL) {
4656 redirp = &(redir->next);
4658 *redirp = redir = xzalloc(sizeof(*redir));
4659 /* redir->next = NULL; */
4660 /* redir->rd_filename = NULL; */
4661 redir->rd_type = style;
4662 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4664 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4665 redir_table[style].descrip);
4667 redir->rd_dup = dup_num;
4668 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4669 /* Erik had a check here that the file descriptor in question
4670 * is legit; I postpone that to "run time"
4671 * A "-" representation of "close me" shows up as a -3 here */
4672 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4673 redir->rd_fd, redir->rd_dup);
4675 /* Set ctx->pending_redirect, so we know what to do at the
4676 * end of the next parsed word. */
4677 ctx->pending_redirect = redir;
4682 /* If a redirect is immediately preceded by a number, that number is
4683 * supposed to tell which file descriptor to redirect. This routine
4684 * looks for such preceding numbers. In an ideal world this routine
4685 * needs to handle all the following classes of redirects...
4686 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4687 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4688 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4689 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4691 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4693 * ... If n is quoted, the number shall not be recognized as part of
4694 * the redirection expression. For example:
4696 * writes the character 2 into file a"
4697 * We are getting it right by setting ->o_quoted on any \<char>
4699 * A -1 return means no valid number was found,
4700 * the caller should use the appropriate default for this redirection.
4702 static int redirect_opt_num(o_string *o)
4706 if (o->data == NULL)
4708 num = bb_strtou(o->data, NULL, 10);
4709 if (errno || num < 0)
4711 o_reset_to_empty_unquoted(o);
4716 #define fetch_till_str(as_string, input, word, skip_tabs) \
4717 fetch_till_str(input, word, skip_tabs)
4719 static char *fetch_till_str(o_string *as_string,
4720 struct in_str *input,
4724 o_string heredoc = NULL_O_STRING;
4730 ch = i_getch(input);
4731 nommu_addchr(as_string, ch);
4733 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4734 heredoc.data[past_EOL] = '\0';
4735 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4736 return heredoc.data;
4739 o_addchr(&heredoc, ch);
4740 past_EOL = heredoc.length;
4743 ch = i_getch(input);
4744 nommu_addchr(as_string, ch);
4745 } while (skip_tabs && ch == '\t');
4746 } while (ch == '\n');
4749 o_free_unsafe(&heredoc);
4752 o_addchr(&heredoc, ch);
4753 nommu_addchr(as_string, ch);
4757 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4758 * and load them all. There should be exactly heredoc_cnt of them.
4760 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4762 struct pipe *pi = ctx->list_head;
4764 while (pi && heredoc_cnt) {
4766 struct command *cmd = pi->cmds;
4768 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4770 cmd->argv ? cmd->argv[0] : "NONE");
4771 for (i = 0; i < pi->num_cmds; i++) {
4772 struct redir_struct *redir = cmd->redirects;
4774 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4775 i, cmd->argv ? cmd->argv[0] : "NONE");
4777 if (redir->rd_type == REDIRECT_HEREDOC) {
4780 redir->rd_type = REDIRECT_HEREDOC2;
4781 /* redir->dup is (ab)used to indicate <<- */
4782 p = fetch_till_str(&ctx->as_string, input,
4783 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4785 syntax_error("unexpected EOF in here document");
4788 free(redir->rd_filename);
4789 redir->rd_filename = p;
4792 redir = redir->next;
4799 /* Should be 0. If it isn't, it's a parse error */
4801 bb_error_msg_and_die("heredoc BUG 2");
4807 #if ENABLE_HUSH_TICK
4808 static FILE *generate_stream_from_string(const char *s)
4811 int pid, channel[2];
4817 pid = BB_MMU ? fork() : vfork();
4819 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4821 if (pid == 0) { /* child */
4822 disable_restore_tty_pgrp_on_exit();
4823 /* Process substitution is not considered to be usual
4824 * 'command execution'.
4825 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4832 close(channel[0]); /* NB: close _first_, then move fd! */
4833 xmove_fd(channel[1], 1);
4834 /* Prevent it from trying to handle ctrl-z etc */
4835 IF_HUSH_JOB(G.run_list_level = 1;)
4837 reset_traps_to_defaults();
4838 parse_and_run_string(s);
4839 _exit(G.last_exitcode);
4841 /* We re-execute after vfork on NOMMU. This makes this script safe:
4842 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4843 * huge=`cat BIG` # was blocking here forever
4846 re_execute_shell(&to_free,
4854 enable_restore_tty_pgrp_on_exit();
4859 pf = fdopen(channel[0], "r");
4863 /* Return code is exit status of the process that is run. */
4864 static int process_command_subs(o_string *dest, const char *s)
4867 struct in_str pipe_str;
4870 pf = generate_stream_from_string(s);
4873 close_on_exec_on(fileno(pf));
4875 /* Now send results of command back into original context */
4876 setup_file_in_str(&pipe_str, pf);
4878 while ((ch = i_getch(&pipe_str)) != EOF) {
4884 o_addchr(dest, '\n');
4887 o_addQchr(dest, ch);
4890 debug_printf("done reading from pipe, pclose()ing\n");
4891 /* Note: we got EOF, and we just close the read end of the pipe.
4892 * We do not wait for the `cmd` child to terminate. bash and ash do.
4894 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4895 * `false`; echo $? - bash outputs "1"
4898 debug_printf("closed FILE from child. return 0\n");
4903 static int parse_group(o_string *dest, struct parse_context *ctx,
4904 struct in_str *input, int ch)
4906 /* dest contains characters seen prior to ( or {.
4907 * Typically it's empty, but for function defs,
4908 * it contains function name (without '()'). */
4909 struct pipe *pipe_list;
4911 struct command *command = ctx->command;
4913 debug_printf_parse("parse_group entered\n");
4914 #if ENABLE_HUSH_FUNCTIONS
4915 if (ch == '(' && !dest->o_quoted) {
4917 if (done_word(dest, ctx))
4920 goto skip; /* (... */
4921 if (command->argv[1]) { /* word word ... (... */
4922 syntax_error_unexpected_ch('(');
4925 /* it is "word(..." or "word (..." */
4927 ch = i_getch(input);
4928 while (ch == ' ' || ch == '\t');
4930 syntax_error_unexpected_ch(ch);
4933 nommu_addchr(&ctx->as_string, ch);
4935 ch = i_getch(input);
4936 while (ch == ' ' || ch == '\t' || ch == '\n');
4938 syntax_error_unexpected_ch(ch);
4941 nommu_addchr(&ctx->as_string, ch);
4942 command->grp_type = GRP_FUNCTION;
4946 if (command->argv /* word [word]{... */
4947 || dest->length /* word{... */
4948 || dest->o_quoted /* ""{... */
4951 debug_printf_parse("parse_group return 1: "
4952 "syntax error, groups and arglists don't mix\n");
4956 #if ENABLE_HUSH_FUNCTIONS
4962 command->grp_type = GRP_SUBSHELL;
4964 /* bash does not allow "{echo...", requires whitespace */
4965 ch = i_getch(input);
4966 if (ch != ' ' && ch != '\t' && ch != '\n') {
4967 syntax_error_unexpected_ch(ch);
4970 nommu_addchr(&ctx->as_string, ch);
4975 char *as_string = NULL;
4977 pipe_list = parse_stream(&as_string, input, endch);
4980 o_addstr(&ctx->as_string, as_string);
4982 /* empty ()/{} or parse error? */
4983 if (!pipe_list || pipe_list == ERR_PTR) {
4984 /* parse_stream already emitted error msg */
4988 debug_printf_parse("parse_group return 1: "
4989 "parse_stream returned %p\n", pipe_list);
4992 command->group = pipe_list;
4994 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4995 command->group_as_string = as_string;
4996 debug_printf_parse("end of group, remembering as:'%s'\n",
4997 command->group_as_string);
5000 debug_printf_parse("parse_group return 0\n");
5002 /* command remains "open", available for possible redirects */
5005 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5006 /* Subroutines for copying $(...) and `...` things */
5007 static void add_till_backquote(o_string *dest, struct in_str *input);
5009 static void add_till_single_quote(o_string *dest, struct in_str *input)
5012 int ch = i_getch(input);
5014 syntax_error_unterm_ch('\'');
5015 /*xfunc_die(); - redundant */
5022 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5023 static void add_till_double_quote(o_string *dest, struct in_str *input)
5026 int ch = i_getch(input);
5028 syntax_error_unterm_ch('"');
5029 /*xfunc_die(); - redundant */
5033 if (ch == '\\') { /* \x. Copy both chars. */
5035 ch = i_getch(input);
5039 add_till_backquote(dest, input);
5043 //if (ch == '$') ...
5046 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5048 * "Within the backquoted style of command substitution, backslash
5049 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5050 * The search for the matching backquote shall be satisfied by the first
5051 * backquote found without a preceding backslash; during this search,
5052 * if a non-escaped backquote is encountered within a shell comment,
5053 * a here-document, an embedded command substitution of the $(command)
5054 * form, or a quoted string, undefined results occur. A single-quoted
5055 * or double-quoted string that begins, but does not end, within the
5056 * "`...`" sequence produces undefined results."
5058 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5060 static void add_till_backquote(o_string *dest, struct in_str *input)
5063 int ch = i_getch(input);
5065 syntax_error_unterm_ch('`');
5066 /*xfunc_die(); - redundant */
5071 /* \x. Copy both chars unless it is \` */
5072 int ch2 = i_getch(input);
5074 syntax_error_unterm_ch('`');
5075 /*xfunc_die(); - redundant */
5077 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5084 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5085 * quoting and nested ()s.
5086 * "With the $(command) style of command substitution, all characters
5087 * following the open parenthesis to the matching closing parenthesis
5088 * constitute the command. Any valid shell script can be used for command,
5089 * except a script consisting solely of redirections which produces
5090 * unspecified results."
5092 * echo $(echo '(TEST)' BEST) (TEST) BEST
5093 * echo $(echo 'TEST)' BEST) TEST) BEST
5094 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5096 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5100 int ch = i_getch(input);
5102 syntax_error_unterm_ch(')');
5103 /*xfunc_die(); - redundant */
5111 if (i_peek(input) == ')') {
5119 add_till_single_quote(dest, input);
5124 add_till_double_quote(dest, input);
5129 /* \x. Copy verbatim. Important for \(, \) */
5130 ch = i_getch(input);
5132 syntax_error_unterm_ch(')');
5133 /*xfunc_die(); - redundant */
5140 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5142 /* Return code: 0 for OK, 1 for syntax error */
5144 #define handle_dollar(as_string, dest, input) \
5145 handle_dollar(dest, input)
5147 static int handle_dollar(o_string *as_string,
5149 struct in_str *input)
5152 int ch = i_peek(input); /* first character after the $ */
5153 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5155 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5157 ch = i_getch(input);
5158 nommu_addchr(as_string, ch);
5160 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5162 debug_printf_parse(": '%c'\n", ch);
5163 o_addchr(dest, ch | quote_mask);
5166 if (!isalnum(ch) && ch != '_')
5168 ch = i_getch(input);
5169 nommu_addchr(as_string, ch);
5171 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5172 } else if (isdigit(ch)) {
5174 ch = i_getch(input);
5175 nommu_addchr(as_string, ch);
5176 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5177 debug_printf_parse(": '%c'\n", ch);
5178 o_addchr(dest, ch | quote_mask);
5179 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5180 } else switch (ch) {
5182 case '!': /* last bg pid */
5183 case '?': /* last exit code */
5184 case '#': /* number of args */
5185 case '*': /* args */
5186 case '@': /* args */
5187 goto make_one_char_var;
5189 bool first_char, all_digits;
5191 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5192 ch = i_getch(input);
5193 nommu_addchr(as_string, ch);
5194 /* TODO: maybe someone will try to escape the '}' */
5199 ch = i_getch(input);
5200 nommu_addchr(as_string, ch);
5207 /* ${#var}: length of var contents */
5217 && ( (all_digits && !isdigit(ch))
5218 || (!all_digits && !isalnum(ch) && ch != '_')
5221 /* handle parameter expansions
5222 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5227 case ':': /* null modifier */
5228 if (expansion == 0) {
5229 debug_printf_parse(": null modifier\n");
5234 case '#': /* remove prefix */
5235 case '%': /* remove suffix */
5236 if (expansion == 0) {
5237 debug_printf_parse(": remove suffix/prefix\n");
5242 case '-': /* default value */
5243 case '=': /* assign default */
5244 case '+': /* alternative */
5245 case '?': /* error indicate */
5246 debug_printf_parse(": parameter expansion\n");
5251 syntax_error_unterm_str("${name}");
5252 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5257 debug_printf_parse(": '%c'\n", ch);
5258 o_addchr(dest, ch | quote_mask);
5262 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5265 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5270 ch = i_getch(input);
5271 nommu_addchr(as_string, ch);
5272 # if ENABLE_SH_MATH_SUPPORT
5273 if (i_peek(input) == '(') {
5274 ch = i_getch(input);
5275 nommu_addchr(as_string, ch);
5276 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5277 o_addchr(dest, /*quote_mask |*/ '+');
5281 add_till_closing_paren(dest, input, true);
5284 o_addstr(as_string, dest->data + pos);
5285 o_addchr(as_string, ')');
5286 o_addchr(as_string, ')');
5289 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5293 # if ENABLE_HUSH_TICK
5294 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5295 o_addchr(dest, quote_mask | '`');
5299 add_till_closing_paren(dest, input, false);
5302 o_addstr(as_string, dest->data + pos);
5303 o_addchr(as_string, '`');
5306 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5312 ch = i_getch(input);
5313 nommu_addchr(as_string, ch);
5315 if (isalnum(ch)) { /* it's $_name or $_123 */
5321 /* $_ Shell or shell script name; or last cmd name */
5322 /* $- Option flags set by set builtin or shell options (-i etc) */
5324 o_addQchr(dest, '$');
5326 debug_printf_parse("handle_dollar return 0\n");
5331 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5332 parse_stream_dquoted(dest, input, dquote_end)
5334 static int parse_stream_dquoted(o_string *as_string,
5336 struct in_str *input,
5343 ch = i_getch(input);
5345 nommu_addchr(as_string, ch);
5346 if (ch == dquote_end) { /* may be only '"' or EOF */
5347 if (dest->o_assignment == NOT_ASSIGNMENT)
5348 dest->o_escape ^= 1;
5349 debug_printf_parse("parse_stream_dquoted return 0\n");
5352 /* note: can't move it above ch == dquote_end check! */
5354 syntax_error_unterm_ch('"');
5355 /*xfunc_die(); - redundant */
5359 next = i_peek(input);
5361 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5362 ch, ch, dest->o_escape);
5365 syntax_error("\\<eof>");
5369 * "The backslash retains its special meaning [in "..."]
5370 * only when followed by one of the following characters:
5371 * $, `, ", \, or <newline>. A double quote may be quoted
5372 * within double quotes by preceding it with a backslash.
5374 if (strchr("$`\"\\\n", next) != NULL) {
5375 ch = i_getch(input);
5377 o_addqchr(dest, ch);
5378 nommu_addchr(as_string, ch);
5381 o_addqchr(dest, '\\');
5382 nommu_addchr(as_string, '\\');
5387 if (handle_dollar(as_string, dest, input) != 0) {
5388 debug_printf_parse("parse_stream_dquoted return 1: "
5389 "handle_dollar returned non-0\n");
5394 #if ENABLE_HUSH_TICK
5396 //int pos = dest->length;
5397 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5398 o_addchr(dest, 0x80 | '`');
5399 add_till_backquote(dest, input);
5400 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5401 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5405 o_addQchr(dest, ch);
5407 && (dest->o_assignment == MAYBE_ASSIGNMENT
5408 || dest->o_assignment == WORD_IS_KEYWORD)
5409 && is_well_formed_var_name(dest->data, '=')
5411 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5417 * Scan input until EOF or end_trigger char.
5418 * Return a list of pipes to execute, or NULL on EOF
5419 * or if end_trigger character is met.
5420 * On syntax error, exit is shell is not interactive,
5421 * reset parsing machinery and start parsing anew,
5422 * or return ERR_PTR.
5424 static struct pipe *parse_stream(char **pstring,
5425 struct in_str *input,
5428 struct parse_context ctx;
5429 o_string dest = NULL_O_STRING;
5433 /* Double-quote state is handled in the state variable is_in_dquote.
5434 * A single-quote triggers a bypass of the main loop until its mate is
5435 * found. When recursing, quote state is passed in via dest->o_escape.
5437 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5438 end_trigger ? : 'X');
5441 G.ifs = get_local_var_value("IFS");
5446 #if ENABLE_HUSH_INTERACTIVE
5447 input->promptmode = 0; /* PS1 */
5449 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5450 initialize_context(&ctx);
5455 const char *is_special;
5459 redir_type redir_style;
5462 /* dest.o_quoted = 1; - already is (see below) */
5463 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5466 /* We reached closing '"' */
5469 ch = i_getch(input);
5470 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5471 ch, ch, dest.o_escape);
5476 syntax_error_unterm_str("here document");
5479 /* end_trigger == '}' case errors out earlier,
5480 * checking only ')' */
5481 if (end_trigger == ')') {
5482 syntax_error_unterm_ch('('); /* exits */
5483 /* goto parse_error; */
5486 if (done_word(&dest, &ctx)) {
5490 done_pipe(&ctx, PIPE_SEQ);
5492 /* If we got nothing... */
5493 /* (this makes bare "&" cmd a no-op.
5494 * bash says: "syntax error near unexpected token '&'") */
5495 if (pi->num_cmds == 0
5496 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5502 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5504 *pstring = ctx.as_string.data;
5506 o_free_unsafe(&ctx.as_string);
5509 debug_printf_parse("parse_stream return %p\n", pi);
5512 nommu_addchr(&ctx.as_string, ch);
5513 is_ifs = strchr(G.ifs, ch);
5514 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5515 "\\$\"" IF_HUSH_TICK("`") /* always special */
5518 if (!is_special && !is_ifs) { /* ordinary char */
5520 o_addQchr(&dest, ch);
5521 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5522 || dest.o_assignment == WORD_IS_KEYWORD)
5524 && is_well_formed_var_name(dest.data, '=')
5526 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5532 if (done_word(&dest, &ctx)) {
5536 #if ENABLE_HUSH_CASE
5537 /* "case ... in <newline> word) ..." -
5538 * newlines are ignored (but ';' wouldn't be) */
5539 if (ctx.command->argv == NULL
5540 && ctx.ctx_res_w == RES_MATCH
5545 /* Treat newline as a command separator. */
5546 done_pipe(&ctx, PIPE_SEQ);
5547 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5549 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5554 dest.o_assignment = MAYBE_ASSIGNMENT;
5556 /* note: if (is_ifs) continue;
5557 * will still trigger for us */
5561 /* "cmd}" or "cmd }..." without semicolon or &:
5562 * } is an ordinary char in this case, even inside { cmd; }
5563 * Pathological example: { ""}; } should exec "}" cmd
5566 if (!IS_NULL_CMD(ctx.command) /* cmd } */
5567 || dest.length != 0 /* word} */
5568 || dest.o_quoted /* ""} */
5572 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5573 goto skip_end_trigger;
5574 /* else: } does terminate a group */
5577 if (end_trigger && end_trigger == ch
5578 && (heredoc_cnt == 0 || end_trigger != ';')
5581 /* This is technically valid:
5582 * { cat <<HERE; }; echo Ok
5586 * but we don't support this.
5587 * We require heredoc to be in enclosing {}/(),
5590 syntax_error_unterm_str("here document");
5593 if (done_word(&dest, &ctx)) {
5596 done_pipe(&ctx, PIPE_SEQ);
5597 dest.o_assignment = MAYBE_ASSIGNMENT;
5598 /* Do we sit outside of any if's, loops or case's? */
5600 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5604 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5606 *pstring = ctx.as_string.data;
5608 o_free_unsafe(&ctx.as_string);
5611 debug_printf_parse("parse_stream return %p: "
5612 "end_trigger char found\n",
5614 return ctx.list_head;
5623 next = i_peek(input);
5626 /* Catch <, > before deciding whether this word is
5627 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5630 redir_fd = redirect_opt_num(&dest);
5631 if (done_word(&dest, &ctx)) {
5634 redir_style = REDIRECT_OVERWRITE;
5636 redir_style = REDIRECT_APPEND;
5637 ch = i_getch(input);
5638 nommu_addchr(&ctx.as_string, ch);
5641 else if (next == '(') {
5642 syntax_error(">(process) not supported");
5646 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5648 continue; /* back to top of while (1) */
5650 redir_fd = redirect_opt_num(&dest);
5651 if (done_word(&dest, &ctx)) {
5654 redir_style = REDIRECT_INPUT;
5656 redir_style = REDIRECT_HEREDOC;
5658 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5659 ch = i_getch(input);
5660 nommu_addchr(&ctx.as_string, ch);
5661 } else if (next == '>') {
5662 redir_style = REDIRECT_IO;
5663 ch = i_getch(input);
5664 nommu_addchr(&ctx.as_string, ch);
5667 else if (next == '(') {
5668 syntax_error("<(process) not supported");
5672 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5674 continue; /* back to top of while (1) */
5677 if (dest.o_assignment == MAYBE_ASSIGNMENT
5678 /* check that we are not in word in "a=1 2>word b=1": */
5679 && !ctx.pending_redirect
5681 /* ch is a special char and thus this word
5682 * cannot be an assignment */
5683 dest.o_assignment = NOT_ASSIGNMENT;
5688 if (dest.length == 0) {
5691 if (ch == EOF || ch == '\n')
5694 /* note: we do not add it to &ctx.as_string */
5696 nommu_addchr(&ctx.as_string, '\n');
5698 o_addQchr(&dest, ch);
5703 syntax_error("\\<eof>");
5706 ch = i_getch(input);
5708 o_addchr(&dest, '\\');
5709 nommu_addchr(&ctx.as_string, '\\');
5710 o_addchr(&dest, ch);
5711 nommu_addchr(&ctx.as_string, ch);
5712 /* Example: echo Hello \2>file
5713 * we need to know that word 2 is quoted */
5718 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5719 debug_printf_parse("parse_stream parse error: "
5720 "handle_dollar returned non-0\n");
5727 ch = i_getch(input);
5729 syntax_error_unterm_ch('\'');
5730 /*xfunc_die(); - redundant */
5732 nommu_addchr(&ctx.as_string, ch);
5735 if (dest.o_assignment == NOT_ASSIGNMENT)
5736 o_addqchr(&dest, ch);
5738 o_addchr(&dest, ch);
5743 is_in_dquote ^= 1; /* invert */
5744 if (dest.o_assignment == NOT_ASSIGNMENT)
5747 #if ENABLE_HUSH_TICK
5752 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5753 o_addchr(&dest, '`');
5757 add_till_backquote(&dest, input);
5759 o_addstr(&ctx.as_string, dest.data + pos);
5760 o_addchr(&ctx.as_string, '`');
5762 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5763 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5768 #if ENABLE_HUSH_CASE
5771 if (done_word(&dest, &ctx)) {
5774 done_pipe(&ctx, PIPE_SEQ);
5775 #if ENABLE_HUSH_CASE
5776 /* Eat multiple semicolons, detect
5777 * whether it means something special */
5782 ch = i_getch(input);
5783 nommu_addchr(&ctx.as_string, ch);
5784 if (ctx.ctx_res_w == RES_CASEI) {
5785 ctx.ctx_dsemicolon = 1;
5786 ctx.ctx_res_w = RES_MATCH;
5792 /* We just finished a cmd. New one may start
5793 * with an assignment */
5794 dest.o_assignment = MAYBE_ASSIGNMENT;
5797 if (done_word(&dest, &ctx)) {
5801 ch = i_getch(input);
5802 nommu_addchr(&ctx.as_string, ch);
5803 done_pipe(&ctx, PIPE_AND);
5805 done_pipe(&ctx, PIPE_BG);
5809 if (done_word(&dest, &ctx)) {
5812 #if ENABLE_HUSH_CASE
5813 if (ctx.ctx_res_w == RES_MATCH)
5814 break; /* we are in case's "word | word)" */
5816 if (next == '|') { /* || */
5817 ch = i_getch(input);
5818 nommu_addchr(&ctx.as_string, ch);
5819 done_pipe(&ctx, PIPE_OR);
5821 /* we could pick up a file descriptor choice here
5822 * with redirect_opt_num(), but bash doesn't do it.
5823 * "echo foo 2| cat" yields "foo 2". */
5828 #if ENABLE_HUSH_CASE
5829 /* "case... in [(]word)..." - skip '(' */
5830 if (ctx.ctx_res_w == RES_MATCH
5831 && ctx.command->argv == NULL /* not (word|(... */
5832 && dest.length == 0 /* not word(... */
5833 && dest.o_quoted == 0 /* not ""(... */
5839 if (parse_group(&dest, &ctx, input, ch) != 0) {
5844 #if ENABLE_HUSH_CASE
5845 if (ctx.ctx_res_w == RES_MATCH)
5849 /* proper use of this character is caught by end_trigger:
5850 * if we see {, we call parse_group(..., end_trigger='}')
5851 * and it will match } earlier (not here). */
5852 syntax_error_unexpected_ch(ch);
5856 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5862 struct parse_context *pctx;
5863 IF_HAS_KEYWORDS(struct parse_context *p2;)
5865 /* Clean up allocated tree.
5866 * Samples for finding leaks on syntax error recovery path.
5867 * Run them from interactive shell, watch pmap `pidof hush`.
5868 * while if false; then false; fi do break; done
5870 * while if false; then false; fi; do break; fi
5871 * Samples to catch leaks at execution:
5872 * while if (true | {true;}); then echo ok; fi; do break; done
5873 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5877 /* Update pipe/command counts,
5878 * otherwise freeing may miss some */
5879 done_pipe(pctx, PIPE_SEQ);
5880 debug_printf_clean("freeing list %p from ctx %p\n",
5881 pctx->list_head, pctx);
5882 debug_print_tree(pctx->list_head, 0);
5883 free_pipe_list(pctx->list_head);
5884 debug_printf_clean("freed list %p\n", pctx->list_head);
5886 o_free_unsafe(&pctx->as_string);
5888 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5892 IF_HAS_KEYWORDS(pctx = p2;)
5893 } while (HAS_KEYWORDS && pctx);
5894 /* Free text, clear all dest fields */
5896 /* If we are not in top-level parse, we return,
5897 * our caller will propagate error.
5899 if (end_trigger != ';') {
5907 /* Discard cached input, force prompt */
5909 IF_HUSH_INTERACTIVE(input->promptme = 1;)
5914 /* Executing from string: eval, sh -c '...'
5915 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5916 * end_trigger controls how often we stop parsing
5917 * NUL: parse all, execute, return
5918 * ';': parse till ';' or newline, execute, repeat till EOF
5920 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5923 struct pipe *pipe_list;
5925 pipe_list = parse_stream(NULL, inp, end_trigger);
5926 if (!pipe_list) /* EOF */
5928 debug_print_tree(pipe_list, 0);
5929 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5930 run_and_free_list(pipe_list);
5934 static void parse_and_run_string(const char *s)
5936 struct in_str input;
5937 setup_string_in_str(&input, s);
5938 parse_and_run_stream(&input, '\0');
5941 static void parse_and_run_file(FILE *f)
5943 struct in_str input;
5944 setup_file_in_str(&input, f);
5945 parse_and_run_stream(&input, ';');
5948 /* Called a few times only (or even once if "sh -c") */
5949 static void block_signals(int second_time)
5954 mask = (1 << SIGQUIT);
5955 if (G_interactive_fd) {
5956 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
5957 if (G.saved_tty_pgrp) /* we have ctty, job control sigs work */
5958 mask |= SPECIAL_JOB_SIGS;
5960 G.non_DFL_mask = mask;
5963 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5967 sigaddset(&G.blocked_set, sig);
5971 sigdelset(&G.blocked_set, SIGCHLD);
5973 sigprocmask(SIG_SETMASK, &G.blocked_set,
5974 second_time ? NULL : &G.inherited_set);
5975 /* POSIX allows shell to re-enable SIGCHLD
5976 * even if it was SIG_IGN on entry */
5977 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5979 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5984 static void maybe_set_to_sigexit(int sig)
5986 void (*handler)(int);
5987 /* non_DFL_mask'ed signals are, well, masked,
5988 * no need to set handler for them.
5990 if (!((G.non_DFL_mask >> sig) & 1)) {
5991 handler = signal(sig, sigexit);
5992 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5993 signal(sig, handler);
5996 /* Set handlers to restore tty pgrp and exit */
5997 static void set_fatal_handlers(void)
5999 /* We _must_ restore tty pgrp on fatal signals */
6001 maybe_set_to_sigexit(SIGILL );
6002 maybe_set_to_sigexit(SIGFPE );
6003 maybe_set_to_sigexit(SIGBUS );
6004 maybe_set_to_sigexit(SIGSEGV);
6005 maybe_set_to_sigexit(SIGTRAP);
6006 } /* else: hush is perfect. what SEGV? */
6007 maybe_set_to_sigexit(SIGABRT);
6008 /* bash 3.2 seems to handle these just like 'fatal' ones */
6009 maybe_set_to_sigexit(SIGPIPE);
6010 maybe_set_to_sigexit(SIGALRM);
6011 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6012 * if we aren't interactive... but in this case
6013 * we never want to restore pgrp on exit, and this fn is not called */
6014 /*maybe_set_to_sigexit(SIGHUP );*/
6015 /*maybe_set_to_sigexit(SIGTERM);*/
6016 /*maybe_set_to_sigexit(SIGINT );*/
6020 static int set_mode(const char cstate, const char mode)
6022 int state = (cstate == '-' ? 1 : 0);
6024 case 'n': G.fake_mode = state; break;
6025 case 'x': /*G.debug_mode = state;*/ break;
6026 default: return EXIT_FAILURE;
6028 return EXIT_SUCCESS;
6031 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6032 int hush_main(int argc, char **argv)
6034 static const struct variable const_shell_ver = {
6036 .varstr = (char*)hush_version_str,
6037 .max_len = 1, /* 0 can provoke free(name) */
6041 int signal_mask_is_inited = 0;
6044 struct variable *cur_var;
6047 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6048 G.last_exitcode = EXIT_SUCCESS;
6050 G.argv0_for_re_execing = argv[0];
6052 /* Deal with HUSH_VERSION */
6053 G.shell_ver = const_shell_ver; /* copying struct here */
6054 G.top_var = &G.shell_ver;
6055 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6056 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6057 /* Initialize our shell local variables with the values
6058 * currently living in the environment */
6059 cur_var = G.top_var;
6062 char *value = strchr(*e, '=');
6063 if (value) { /* paranoia */
6064 cur_var->next = xzalloc(sizeof(*cur_var));
6065 cur_var = cur_var->next;
6066 cur_var->varstr = *e;
6067 cur_var->max_len = strlen(*e);
6068 cur_var->flg_export = 1;
6072 debug_printf_env("putenv '%s'\n", hush_version_str);
6073 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
6074 #if ENABLE_FEATURE_EDITING
6075 G.line_input_state = new_line_input_t(FOR_SHELL);
6077 G.global_argc = argc;
6078 G.global_argv = argv;
6079 /* Initialize some more globals to non-zero values */
6081 cmdedit_update_prompt();
6083 if (setjmp(die_jmp)) {
6084 /* xfunc has failed! die die die */
6085 /* no EXIT traps, this is an escape hatch! */
6087 hush_exit(xfunc_error_retval);
6090 /* Shell is non-interactive at first. We need to call
6091 * block_signals(0) if we are going to execute "sh <script>",
6092 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6093 * If we later decide that we are interactive, we run block_signals(0)
6094 * (or re-run block_signals(1) if we ran block_signals(0) before)
6095 * in order to intercept (more) signals.
6099 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6101 opt = getopt(argc, argv, "c:xins"
6104 # if ENABLE_HUSH_FUNCTIONS
6114 G.root_pid = getpid();
6115 G.global_argv = argv + optind;
6116 if (!argv[optind]) {
6117 /* -c 'script' (no params): prevent empty $0 */
6118 *--G.global_argv = argv[0];
6120 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
6121 G.global_argc = argc - optind;
6122 block_signals(0); /* 0: called 1st time */
6123 parse_and_run_string(optarg);
6126 /* Well, we cannot just declare interactiveness,
6127 * we have to have some stuff (ctty, etc) */
6128 /* G_interactive_fd++; */
6131 /* "-s" means "read from stdin", but this is how we always
6132 * operate, so simply do nothing here. */
6135 case '<': /* "big heredoc" support */
6136 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6139 G.root_pid = bb_strtou(optarg, &optarg, 16);
6141 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6143 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6144 # if ENABLE_HUSH_LOOPS
6146 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6151 set_local_var(xstrdup(optarg), 0, opt == 'R');
6153 # if ENABLE_HUSH_FUNCTIONS
6155 struct function *funcp = new_function(optarg);
6156 /* funcp->name is already set to optarg */
6157 /* funcp->body is set to NULL. It's a special case. */
6158 funcp->body_as_string = argv[optind];
6166 if (!set_mode('-', opt))
6170 fprintf(stderr, "Usage: sh [FILE]...\n"
6171 " or: sh -c command [args]...\n\n");
6177 } /* option parsing loop */
6180 G.root_pid = getpid();
6182 /* If we are login shell... */
6183 if (argv[0] && argv[0][0] == '-') {
6185 debug_printf("sourcing /etc/profile\n");
6186 input = fopen_for_read("/etc/profile");
6187 if (input != NULL) {
6188 close_on_exec_on(fileno(input));
6189 block_signals(0); /* 0: called 1st time */
6190 signal_mask_is_inited = 1;
6191 parse_and_run_file(input);
6194 /* bash: after sourcing /etc/profile,
6195 * tries to source (in the given order):
6196 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6197 * stopping of first found. --noprofile turns this off.
6198 * bash also sources ~/.bash_logout on exit.
6199 * If called as sh, skips .bash_XXX files.
6206 * "bash <script>" (which is never interactive (unless -i?))
6207 * sources $BASH_ENV here (without scanning $PATH).
6208 * If called as sh, does the same but with $ENV.
6210 debug_printf("running script '%s'\n", argv[optind]);
6211 G.global_argv = argv + optind;
6212 G.global_argc = argc - optind;
6213 input = xfopen_for_read(argv[optind]);
6214 close_on_exec_on(fileno(input));
6215 if (!signal_mask_is_inited)
6216 block_signals(0); /* 0: called 1st time */
6217 parse_and_run_file(input);
6218 #if ENABLE_FEATURE_CLEAN_UP
6224 /* Up to here, shell was non-interactive. Now it may become one.
6225 * NB: don't forget to (re)run block_signals(0/1) as needed.
6228 /* A shell is interactive if the '-i' flag was given, or if all of
6229 * the following conditions are met:
6231 * no arguments remaining or the -s flag given
6232 * standard input is a terminal
6233 * standard output is a terminal
6234 * Refer to Posix.2, the description of the 'sh' utility.
6237 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6238 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6239 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6240 if (G.saved_tty_pgrp < 0)
6241 G.saved_tty_pgrp = 0;
6243 /* try to dup stdin to high fd#, >= 255 */
6244 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6245 if (G_interactive_fd < 0) {
6246 /* try to dup to any fd */
6247 G_interactive_fd = dup(STDIN_FILENO);
6248 if (G_interactive_fd < 0) {
6250 G_interactive_fd = 0;
6251 G.saved_tty_pgrp = 0;
6254 // TODO: track & disallow any attempts of user
6255 // to (inadvertently) close/redirect G_interactive_fd
6257 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6258 if (G_interactive_fd) {
6259 close_on_exec_on(G_interactive_fd);
6261 if (G.saved_tty_pgrp) {
6262 /* If we were run as 'hush &', sleep until we are
6263 * in the foreground (tty pgrp == our pgrp).
6264 * If we get started under a job aware app (like bash),
6265 * make sure we are now in charge so we don't fight over
6266 * who gets the foreground */
6268 pid_t shell_pgrp = getpgrp();
6269 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6270 if (G.saved_tty_pgrp == shell_pgrp)
6272 /* send TTIN to ourself (should stop us) */
6273 kill(- shell_pgrp, SIGTTIN);
6277 /* Block some signals */
6278 block_signals(signal_mask_is_inited);
6280 if (G.saved_tty_pgrp) {
6281 /* Set other signals to restore saved_tty_pgrp */
6282 set_fatal_handlers();
6283 /* Put ourselves in our own process group
6284 * (bash, too, does this only if ctty is available) */
6285 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6286 /* Grab control of the terminal */
6287 tcsetpgrp(G_interactive_fd, getpid());
6289 /* -1 is special - makes xfuncs longjmp, not exit
6290 * (we reset die_sleep = 0 whereever we [v]fork) */
6291 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6292 } else if (!signal_mask_is_inited) {
6293 block_signals(0); /* 0: called 1st time */
6294 } /* else: block_signals(0) was done before */
6295 #elif ENABLE_HUSH_INTERACTIVE
6296 /* No job control compiled in, only prompt/line editing */
6297 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6298 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6299 if (G_interactive_fd < 0) {
6300 /* try to dup to any fd */
6301 G_interactive_fd = dup(STDIN_FILENO);
6302 if (G_interactive_fd < 0)
6304 G_interactive_fd = 0;
6307 if (G_interactive_fd) {
6308 close_on_exec_on(G_interactive_fd);
6309 block_signals(signal_mask_is_inited);
6310 } else if (!signal_mask_is_inited) {
6314 /* We have interactiveness code disabled */
6315 if (!signal_mask_is_inited) {
6320 * if interactive but not a login shell, sources ~/.bashrc
6321 * (--norc turns this off, --rcfile <file> overrides)
6324 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6325 printf("\n\n%s hush - the humble shell\n", bb_banner);
6326 if (ENABLE_HUSH_HELP)
6327 puts("Enter 'help' for a list of built-in commands.");
6331 parse_and_run_file(stdin);
6334 #if ENABLE_FEATURE_CLEAN_UP
6335 if (G.cwd != bb_msg_unknown)
6337 cur_var = G.top_var->next;
6339 struct variable *tmp = cur_var;
6340 if (!cur_var->max_len)
6341 free(cur_var->varstr);
6342 cur_var = cur_var->next;
6346 hush_exit(G.last_exitcode);
6351 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6352 int lash_main(int argc, char **argv)
6354 //bb_error_msg("lash is deprecated, please use hush instead");
6355 return hush_main(argc, argv);
6363 static int builtin_true(char **argv UNUSED_PARAM)
6368 static int builtin_test(char **argv)
6375 return test_main(argc, argv - argc);
6378 static int builtin_echo(char **argv)
6385 return echo_main(argc, argv - argc);
6388 static int builtin_eval(char **argv)
6390 int rcode = EXIT_SUCCESS;
6393 char *str = expand_strvec_to_string(argv);
6395 * eval "echo Hi; done" ("done" is syntax error):
6396 * "echo Hi" will not execute too.
6398 parse_and_run_string(str);
6400 rcode = G.last_exitcode;
6405 static int builtin_cd(char **argv)
6407 const char *newdir = argv[1];
6408 if (newdir == NULL) {
6409 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6410 * bash says "bash: cd: HOME not set" and does nothing
6413 newdir = get_local_var_value("HOME") ? : "/";
6415 if (chdir(newdir)) {
6416 /* Mimic bash message exactly */
6417 bb_perror_msg("cd: %s", newdir);
6418 return EXIT_FAILURE;
6421 return EXIT_SUCCESS;
6424 static int builtin_exec(char **argv)
6426 if (*++argv == NULL)
6427 return EXIT_SUCCESS; /* bash does this */
6432 /* TODO: if exec fails, bash does NOT exit! We do... */
6433 pseudo_exec_argv(&dummy, argv, 0, NULL);
6438 static int builtin_exit(char **argv)
6440 debug_printf_exec("%s()\n", __func__);
6442 /* interactive bash:
6443 * # trap "echo EEE" EXIT
6446 * There are stopped jobs.
6447 * (if there are _stopped_ jobs, running ones don't count)
6450 # EEE (then bash exits)
6452 * we can use G.exiting = -1 as indicator "last cmd was exit"
6455 /* note: EXIT trap is run by hush_exit */
6456 if (*++argv == NULL)
6457 hush_exit(G.last_exitcode);
6458 /* mimic bash: exit 123abc == exit 255 + error msg */
6459 xfunc_error_retval = 255;
6460 /* bash: exit -2 == exit 254, no error msg */
6461 hush_exit(xatoi(*argv) & 0xff);
6464 static void print_escaped(const char *s)
6470 p = strchrnul(s, '\'');
6471 /* print 'xxxx', possibly just '' */
6472 printf("'%.*s'", (int)(p - s), s);
6477 /* s points to '; print "'''...'''" */
6479 do putchar('\''); while (*++s == '\'');
6484 static int builtin_export(char **argv)
6486 unsigned opt_unexport;
6488 if (argv[1] == NULL) {
6495 /* ash emits: export VAR='VAL'
6496 * bash: declare -x VAR="VAL"
6497 * we follow ash example */
6498 const char *s = *e++;
6499 const char *p = strchr(s, '=');
6501 if (!p) /* wtf? take next variable */
6504 printf("export %.*s", (int)(p - s) + 1, s);
6505 print_escaped(p + 1);
6509 /*fflush(stdout); - done after each builtin anyway */
6511 return EXIT_SUCCESS;
6514 #if ENABLE_HUSH_EXPORT_N
6515 /* "!": do not abort on errors */
6516 /* "+": stop at 1st non-option */
6517 opt_unexport = getopt32(argv, "!+n");
6518 if (opt_unexport == (unsigned)-1)
6519 return EXIT_FAILURE;
6529 /* So far we do not check that name is valid (TODO?) */
6531 if (strchr(name, '=') == NULL) {
6532 struct variable *var;
6534 var = get_local_var(name);
6536 /* export -n NAME (without =VALUE) */
6538 var->flg_export = 0;
6539 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
6541 } /* else: export -n NOT_EXISTING_VAR: no-op */
6544 /* export NAME (without =VALUE) */
6546 var->flg_export = 1;
6547 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6548 putenv(var->varstr);
6551 /* Exporting non-existing variable.
6552 * bash does not put it in environment,
6553 * but remembers that it is exported,
6554 * and does put it in env when it is set later.
6555 * We just set it to "" and export. */
6556 name = xasprintf("%s=", name);
6558 /* (Un)exporting NAME=VALUE */
6559 name = xstrdup(name);
6562 /*export:*/ (opt_unexport ? -1 : 1),
6567 return EXIT_SUCCESS;
6570 static int builtin_trap(char **argv)
6576 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6581 /* No args: print all trapped */
6582 for (i = 0; i < NSIG; ++i) {
6585 print_escaped(G.traps[i]);
6586 printf(" %s\n", get_signame(i));
6589 /*fflush(stdout); - done after each builtin anyway */
6590 return EXIT_SUCCESS;
6594 /* If first arg is a number: reset all specified signals */
6595 sig = bb_strtou(*argv, NULL, 10);
6601 sig = get_signum(*argv++);
6602 if (sig < 0 || sig >= NSIG) {
6604 /* Mimic bash message exactly */
6605 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
6610 G.traps[sig] = xstrdup(new_cmd);
6612 debug_printf("trap: setting SIG%s (%i) to '%s'",
6613 get_signame(sig), sig, G.traps[sig]);
6615 /* There is no signal for 0 (EXIT) */
6620 sigaddset(&G.blocked_set, sig);
6622 /* There was a trap handler, we are removing it
6623 * (if sig has non-DFL handling,
6624 * we don't need to do anything) */
6625 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6627 sigdelset(&G.blocked_set, sig);
6630 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6634 if (!argv[1]) { /* no second arg */
6635 bb_error_msg("trap: invalid arguments");
6636 return EXIT_FAILURE;
6639 /* First arg is "-": reset all specified to default */
6640 /* First arg is "--": skip it, the rest is "handler SIGs..." */
6641 /* Everything else: set arg as signal handler
6642 * (includes "" case, which ignores signal) */
6643 if (argv[0][0] == '-') {
6644 if (argv[0][1] == '\0') { /* "-" */
6645 /* new_cmd remains NULL: "reset these sigs" */
6648 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
6651 /* else: "-something", no special meaning */
6656 goto process_sig_list;
6660 /* built-in 'fg' and 'bg' handler */
6661 static int builtin_fg_bg(char **argv)
6666 if (!G_interactive_fd)
6667 return EXIT_FAILURE;
6669 /* If they gave us no args, assume they want the last backgrounded task */
6671 for (pi = G.job_list; pi; pi = pi->next) {
6672 if (pi->jobid == G.last_jobid) {
6676 bb_error_msg("%s: no current job", argv[0]);
6677 return EXIT_FAILURE;
6679 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6680 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6681 return EXIT_FAILURE;
6683 for (pi = G.job_list; pi; pi = pi->next) {
6684 if (pi->jobid == jobnum) {
6688 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6689 return EXIT_FAILURE;
6691 /* TODO: bash prints a string representation
6692 * of job being foregrounded (like "sleep 1 | cat") */
6693 if (argv[0][0] == 'f' && G.saved_tty_pgrp) {
6694 /* Put the job into the foreground. */
6695 tcsetpgrp(G_interactive_fd, pi->pgrp);
6698 /* Restart the processes in the job */
6699 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6700 for (i = 0; i < pi->num_cmds; i++) {
6701 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6702 pi->cmds[i].is_stopped = 0;
6704 pi->stopped_cmds = 0;
6706 i = kill(- pi->pgrp, SIGCONT);
6708 if (errno == ESRCH) {
6709 delete_finished_bg_job(pi);
6710 return EXIT_SUCCESS;
6712 bb_perror_msg("kill (SIGCONT)");
6715 if (argv[0][0] == 'f') {
6717 return checkjobs_and_fg_shell(pi);
6719 return EXIT_SUCCESS;
6723 #if ENABLE_HUSH_HELP
6724 static int builtin_help(char **argv UNUSED_PARAM)
6726 const struct built_in_command *x;
6729 "Built-in commands:\n"
6730 "------------------\n");
6731 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6732 printf("%s\t%s\n", x->cmd, x->descr);
6735 return EXIT_SUCCESS;
6740 static int builtin_jobs(char **argv UNUSED_PARAM)
6743 const char *status_string;
6745 for (job = G.job_list; job; job = job->next) {
6746 if (job->alive_cmds == job->stopped_cmds)
6747 status_string = "Stopped";
6749 status_string = "Running";
6751 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6753 return EXIT_SUCCESS;
6758 static int builtin_memleak(char **argv UNUSED_PARAM)
6763 /* Crude attempt to find where "free memory" starts,
6764 * sans fragmentation. */
6766 l = (unsigned long)p;
6769 if (l < (unsigned long)p) l = (unsigned long)p;
6772 if (!G.memleak_value)
6773 G.memleak_value = l;
6775 l -= G.memleak_value;
6782 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6787 static int builtin_pwd(char **argv UNUSED_PARAM)
6790 return EXIT_SUCCESS;
6793 static int builtin_read(char **argv)
6796 const char *name = "REPLY";
6800 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6801 * and _after_ that_ it will complain */
6802 if (!is_well_formed_var_name(name, '\0')) {
6803 /* Mimic bash message */
6804 bb_error_msg("read: '%s': not a valid identifier", name);
6809 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6811 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6812 return set_local_var(string, 0, 0);
6815 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6816 * built-in 'set' handler
6818 * set [-abCefhmnuvx] [-o option] [argument...]
6819 * set [+abCefhmnuvx] [+o option] [argument...]
6820 * set -- [argument...]
6823 * Implementations shall support the options in both their hyphen and
6824 * plus-sign forms. These options can also be specified as options to sh.
6826 * Write out all variables and their values: set
6827 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6828 * Turn on the -x and -v options: set -xv
6829 * Unset all positional parameters: set --
6830 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6831 * Set the positional parameters to the expansion of x, even if x expands
6832 * with a leading '-' or '+': set -- $x
6834 * So far, we only support "set -- [argument...]" and some of the short names.
6836 static int builtin_set(char **argv)
6839 char **pp, **g_argv;
6840 char *arg = *++argv;
6844 for (e = G.top_var; e; e = e->next)
6846 return EXIT_SUCCESS;
6850 if (!strcmp(arg, "--")) {
6854 if (arg[0] != '+' && arg[0] != '-')
6856 for (n = 1; arg[n]; ++n)
6857 if (set_mode(arg[0], arg[n]))
6859 } while ((arg = *++argv) != NULL);
6860 /* Now argv[0] is 1st argument */
6863 return EXIT_SUCCESS;
6866 /* NB: G.global_argv[0] ($0) is never freed/changed */
6867 g_argv = G.global_argv;
6868 if (G.global_args_malloced) {
6874 G.global_args_malloced = 1;
6875 pp = xzalloc(sizeof(pp[0]) * 2);
6876 pp[0] = g_argv[0]; /* retain $0 */
6879 /* This realloc's G.global_argv */
6880 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6887 return EXIT_SUCCESS;
6889 /* Nothing known, so abort */
6891 bb_error_msg("set: %s: invalid option", arg);
6892 return EXIT_FAILURE;
6895 static int builtin_shift(char **argv)
6901 if (n >= 0 && n < G.global_argc) {
6902 if (G.global_args_malloced) {
6905 free(G.global_argv[m++]);
6908 memmove(&G.global_argv[1], &G.global_argv[n+1],
6909 G.global_argc * sizeof(G.global_argv[0]));
6910 return EXIT_SUCCESS;
6912 return EXIT_FAILURE;
6915 static int builtin_source(char **argv)
6920 #if ENABLE_HUSH_FUNCTIONS
6924 if (*++argv == NULL)
6925 return EXIT_FAILURE;
6927 if (strchr(*argv, '/') == NULL
6928 && (PATH = get_local_var_value("PATH")) != NULL
6930 /* Search through $PATH */
6932 const char *end = strchrnul(PATH, ':');
6933 int sz = end - PATH; /* must be int! */
6936 char *tmp = xasprintf("%.*s/%s", sz, PATH, *argv);
6937 input = fopen_for_read(tmp);
6940 /* We have xxx::yyyy in $PATH,
6941 * it means "use current dir" */
6942 input = fopen_for_read(*argv);
6951 input = fopen_or_warn(*argv, "r");
6953 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6954 return EXIT_FAILURE;
6957 close_on_exec_on(fileno(input));
6959 #if ENABLE_HUSH_FUNCTIONS
6960 sv_flg = G.flag_return_in_progress;
6961 /* "we are inside sourced file, ok to use return" */
6962 G.flag_return_in_progress = -1;
6964 save_and_replace_G_args(&sv, argv);
6966 parse_and_run_file(input);
6969 restore_G_args(&sv, argv);
6970 #if ENABLE_HUSH_FUNCTIONS
6971 G.flag_return_in_progress = sv_flg;
6974 return G.last_exitcode;
6977 static int builtin_umask(char **argv)
6984 mode_t old_mask = mask;
6987 rc = bb_parse_mode(argv[1], &mask);
6992 * bash: umask: 'q': invalid symbolic mode operator
6993 * bash: umask: 999: octal number out of range
6995 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7000 printf("%04o\n", (unsigned) mask);
7001 /* fall through and restore mask which we set to 0 */
7005 return !rc; /* rc != 0 - success */
7008 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7009 static int builtin_unset(char **argv)
7014 /* "!": do not abort on errors */
7015 /* "+": stop at 1st non-option */
7016 opts = getopt32(argv, "!+vf");
7017 if (opts == (unsigned)-1)
7018 return EXIT_FAILURE;
7020 bb_error_msg("unset: -v and -f are exclusive");
7021 return EXIT_FAILURE;
7027 if (!(opts & 2)) { /* not -f */
7028 if (unset_local_var(*argv)) {
7029 /* unset <nonexistent_var> doesn't fail.
7030 * Error is when one tries to unset RO var.
7031 * Message was printed by unset_local_var. */
7035 #if ENABLE_HUSH_FUNCTIONS
7045 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7046 static int builtin_wait(char **argv)
7048 int ret = EXIT_SUCCESS;
7051 if (*++argv == NULL) {
7052 /* Don't care about wait results */
7053 /* Note 1: must wait until there are no more children */
7054 /* Note 2: must be interruptible */
7056 * $ sleep 3 & sleep 6 & wait
7061 * $ sleep 3 & sleep 6 & wait
7065 * ^C <-- after ~4 sec from keyboard
7068 sigaddset(&G.blocked_set, SIGCHLD);
7069 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7072 if (errno == ECHILD)
7074 /* Wait for SIGCHLD or any other signal of interest */
7075 /* sigtimedwait with infinite timeout: */
7076 sig = sigwaitinfo(&G.blocked_set, NULL);
7078 sig = check_and_run_traps(sig);
7079 if (sig && sig != SIGCHLD) { /* see note 2 */
7085 sigdelset(&G.blocked_set, SIGCHLD);
7086 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7090 /* This is probably buggy wrt interruptible-ness */
7092 pid_t pid = bb_strtou(*argv, NULL, 10);
7094 /* mimic bash message */
7095 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
7096 return EXIT_FAILURE;
7098 if (waitpid(pid, &status, 0) == pid) {
7099 if (WIFSIGNALED(status))
7100 ret = 128 + WTERMSIG(status);
7101 else if (WIFEXITED(status))
7102 ret = WEXITSTATUS(status);
7106 bb_perror_msg("wait %s", *argv);
7115 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
7116 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
7119 def = bb_strtou(argv[1], NULL, 10);
7120 if (errno || def < def_min || argv[2]) {
7121 bb_error_msg("%s: bad arguments", argv[0]);
7129 #if ENABLE_HUSH_LOOPS
7130 static int builtin_break(char **argv)
7133 if (G.depth_of_loop == 0) {
7134 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7135 return EXIT_SUCCESS; /* bash compat */
7137 G.flag_break_continue++; /* BC_BREAK = 1 */
7139 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
7140 if (depth == UINT_MAX)
7141 G.flag_break_continue = BC_BREAK;
7142 if (G.depth_of_loop < depth)
7143 G.depth_break_continue = G.depth_of_loop;
7145 return EXIT_SUCCESS;
7148 static int builtin_continue(char **argv)
7150 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
7151 return builtin_break(argv);
7155 #if ENABLE_HUSH_FUNCTIONS
7156 static int builtin_return(char **argv)
7160 if (G.flag_return_in_progress != -1) {
7161 bb_error_msg("%s: not in a function or sourced script", argv[0]);
7162 return EXIT_FAILURE; /* bash compat */
7165 G.flag_return_in_progress = 1;
7168 * out of range: wraps around at 256, does not error out
7169 * non-numeric param:
7170 * f() { false; return qwe; }; f; echo $?
7171 * bash: return: qwe: numeric argument required <== we do this
7172 * 255 <== we also do this
7174 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);