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 * change { and } from special chars to reserved words
54 * builtins: return, ulimit
55 * follow IFS rules more precisely, including update semantics
56 * figure out what to do with backslash-newline
57 * continuation lines, both explicit and implicit - done?
59 * ^Z handling (and explain it in comments for mere humans)
60 * separate job control from interactiveness
61 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
63 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
65 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
67 /* #include <dmalloc.h> */
74 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
78 /* Debug build knobs */
79 #define LEAK_HUNTING 0
80 #define BUILD_AS_NOMMU 0
81 /* Enable/disable sanity checks. Ok to enable in production,
82 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
83 * Keeping 1 for now even in released versions.
93 # define USE_FOR_NOMMU(...) __VA_ARGS__
94 # define USE_FOR_MMU(...)
97 #if defined SINGLE_APPLET_MAIN
98 /* STANDALONE does not make sense, and won't compile */
99 # undef CONFIG_FEATURE_SH_STANDALONE
100 # undef ENABLE_FEATURE_SH_STANDALONE
101 # undef USE_FEATURE_SH_STANDALONE
102 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
103 # define ENABLE_FEATURE_SH_STANDALONE 0
104 # define USE_FEATURE_SH_STANDALONE(...)
105 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
108 #if !ENABLE_HUSH_INTERACTIVE
109 # undef ENABLE_FEATURE_EDITING
110 # define ENABLE_FEATURE_EDITING 0
111 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
112 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
115 /* Do we support ANY keywords? */
116 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
117 # define HAS_KEYWORDS 1
118 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
119 # define IF_HAS_NO_KEYWORDS(...)
121 # define HAS_KEYWORDS 0
122 # define IF_HAS_KEYWORDS(...)
123 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
126 /* If you comment out one of these below, it will be #defined later
127 * to perform debug printfs to stderr: */
128 #define debug_printf(...) do {} while (0)
129 /* Finer-grained debug switches */
130 #define debug_printf_parse(...) do {} while (0)
131 #define debug_print_tree(a, b) do {} while (0)
132 #define debug_printf_exec(...) do {} while (0)
133 #define debug_printf_env(...) do {} while (0)
134 #define debug_printf_jobs(...) do {} while (0)
135 #define debug_printf_expand(...) do {} while (0)
136 #define debug_printf_glob(...) do {} while (0)
137 #define debug_printf_list(...) do {} while (0)
138 #define debug_printf_subst(...) do {} while (0)
139 #define debug_printf_clean(...) do {} while (0)
141 #define ERR_PTR ((void*)(long)1)
143 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
145 #define SPECIAL_VAR_SYMBOL 3
147 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
149 /* This supports saving pointers malloced in vfork child,
150 * to be freed in the parent. One pointer is saved in
151 * G.argv_from_re_execing global var instead. TODO: unify.
154 typedef struct nommu_save_t {
158 char **argv_from_re_execing;
162 /* The descrip member of this structure is only used to make
163 * debugging output pretty */
164 static const struct {
166 signed char default_fd;
170 { O_RDONLY, 0, "<" },
171 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
172 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
173 { O_RDONLY, 0, "<<" },
174 { O_CREAT|O_RDWR, 1, "<>" },
175 /* Should not be needed. Bogus default_fd helps in debugging */
176 /* { O_RDONLY, 77, "<<" }, */
179 typedef enum reserved_style {
188 #if ENABLE_HUSH_LOOPS
195 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
200 /* two pseudo-keywords support contrived "case" syntax: */
201 RES_MATCH , /* "word)" */
202 RES_CASEI , /* "this command is inside CASE" */
209 typedef struct o_string {
211 int length; /* position where data is appended */
213 /* Protect newly added chars against globbing
214 * (by prepending \ to *, ?, [, \) */
217 /* At least some part of the string was inside '' or "",
218 * possibly empty one: word"", wo''rd etc. */
220 smallint has_empty_slot;
221 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
224 MAYBE_ASSIGNMENT = 0,
225 DEFINITELY_ASSIGNMENT = 1,
227 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
229 /* Used for initialization: o_string foo = NULL_O_STRING; */
230 #define NULL_O_STRING { NULL }
232 /* I can almost use ordinary FILE*. Is open_memstream() universally
233 * available? Where is it documented? */
234 typedef struct in_str {
236 /* eof_flag=1: last char in ->p is really an EOF */
237 char eof_flag; /* meaningless if ->p == NULL */
239 #if ENABLE_HUSH_INTERACTIVE
241 smallint promptmode; /* 0: PS1, 1: PS2 */
244 int (*get) (struct in_str *);
245 int (*peek) (struct in_str *);
247 #define i_getch(input) ((input)->get(input))
248 #define i_peek(input) ((input)->peek(input))
250 struct redir_struct {
251 struct redir_struct *next;
252 char *rd_filename; /* filename */
253 int rd_fd; /* fd to redirect */
254 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
256 smallint rd_type; /* (enum redir_type) */
257 /* note: for heredocs, rd_filename contains heredoc delimiter,
258 * and subsequently heredoc itself; and rd_dup is a bitmask:
259 * 1: do we need to trim leading tabs?
260 * 2: is heredoc quoted (<<'delim' syntax) ?
263 typedef enum redir_type {
264 REDIRECT_INVALID = 0,
266 REDIRECT_OVERWRITE = 2,
268 REDIRECT_HEREDOC = 4,
270 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
273 REDIRFD_SYNTAX_ERR = -2,
274 REDIRFD_TO_FILE = -1,
275 /* otherwise, rd_fd is redirected to rd_dup */
277 HEREDOC_SKIPTABS = 1,
283 pid_t pid; /* 0 if exited */
284 int assignment_cnt; /* how many argv[i] are assignments? */
285 smallint is_stopped; /* is the command currently running? */
286 smallint grp_type; /* GRP_xxx */
288 #define GRP_SUBSHELL 1
289 #if ENABLE_HUSH_FUNCTIONS
290 # define GRP_FUNCTION 2
292 struct pipe *group; /* if non-NULL, this "command" is { list },
293 * ( list ), or a compound statement */
295 char *group_as_string;
297 #if ENABLE_HUSH_FUNCTIONS
298 struct function *child_func;
299 /* This field is used to prevent a bug here:
300 * while...do f1() {a;}; f1; f1 {b;}; f1; done
301 * When we execute "f1() {a;}" cmd, we create new function and clear
302 * cmd->group, cmd->group_as_string, cmd->argv[0].
303 * when we execute "f1 {b;}", we notice that f1 exists,
304 * and that it's "parent cmd" struct is still "alive",
305 * we put those fields back into cmd->xxx
306 * (struct function has ->parent_cmd ptr to facilitate that).
307 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
308 * Without this trick, loop would execute a;b;b;b;...
309 * instead of correct sequence a;b;a;b;...
310 * When command is freed, it severs the link
311 * (sets ->child_func->parent_cmd to NULL).
314 char **argv; /* command name and arguments */
315 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
316 * and on execution these are substituted with their values.
317 * Substitution can make _several_ words out of one argv[n]!
318 * Example: argv[0]=='.^C*^C.' here: echo .$*.
319 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
321 struct redir_struct *redirects; /* I/O redirections */
326 int num_cmds; /* total number of commands in pipe */
327 int alive_cmds; /* number of commands running (not exited) */
328 int stopped_cmds; /* number of commands alive, but stopped */
330 int jobid; /* job number */
331 pid_t pgrp; /* process group ID for the job */
332 char *cmdtext; /* name of job */
334 struct command *cmds; /* array of commands in pipe */
335 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
336 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
337 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
339 typedef enum pipe_style {
346 /* This holds pointers to the various results of parsing */
347 struct parse_context {
348 /* linked list of pipes */
349 struct pipe *list_head;
350 /* last pipe (being constructed right now) */
352 /* last command in pipe (being constructed right now) */
353 struct command *command;
354 /* last redirect in command->redirects list */
355 struct redir_struct *pending_redirect;
361 smallint ctx_inverted; /* "! cmd | cmd" */
363 smallint ctx_dsemicolon; /* ";;" seen */
365 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
367 /* group we are enclosed in:
368 * example: "if pipe1; pipe2; then pipe3; fi"
369 * when we see "if" or "then", we malloc and copy current context,
370 * and make ->stack point to it. then we parse pipeN.
371 * when closing "then" / fi" / whatever is found,
372 * we move list_head into ->stack->command->group,
373 * copy ->stack into current context, and delete ->stack.
374 * (parsing of { list } and ( list ) doesn't use this method)
376 struct parse_context *stack;
380 /* On program start, environ points to initial environment.
381 * putenv adds new pointers into it, unsetenv removes them.
382 * Neither of these (de)allocates the strings.
383 * setenv allocates new strings in malloc space and does putenv,
384 * and thus setenv is unusable (leaky) for shell's purposes */
385 #define setenv(...) setenv_is_leaky_dont_use()
387 struct variable *next;
388 char *varstr; /* points to "name=" portion */
389 int max_len; /* if > 0, name is part of initial env; else name is malloced */
390 smallint flg_export; /* putenv should be done on this var */
391 smallint flg_read_only;
399 #if ENABLE_HUSH_FUNCTIONS
401 struct function *next;
403 struct command *parent_cmd;
406 char *body_as_string;
412 /* "Globals" within this file */
413 /* Sorted roughly by size (smaller offsets == smaller code) */
415 #if ENABLE_HUSH_INTERACTIVE
416 /* 'interactive_fd' is a fd# open to ctty, if we have one
417 * _AND_ if we decided to act interactively */
421 #define G_interactive_fd (G.interactive_fd)
423 #define G_interactive_fd 0
425 #if ENABLE_FEATURE_EDITING
426 line_input_t *line_input_state;
432 pid_t saved_tty_pgrp;
434 struct pipe *job_list;
435 struct pipe *toplevel_list;
436 //// smallint ctrl_z_flag;
438 smallint flag_SIGINT;
439 #if ENABLE_HUSH_LOOPS
440 smallint flag_break_continue;
443 smallint exiting; /* used to prevent EXIT trap recursion */
444 /* These four support $?, $#, and $1 */
445 smalluint last_exitcode;
446 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
447 smalluint global_args_malloced;
448 /* how many non-NULL argv's we have. NB: $# + 1 */
452 char *argv0_for_re_execing;
454 #if ENABLE_HUSH_LOOPS
455 unsigned depth_break_continue;
456 unsigned depth_of_loop;
460 struct variable *top_var; /* = &G.shell_ver (set in main()) */
461 struct variable shell_ver;
462 #if ENABLE_HUSH_FUNCTIONS
463 struct function *top_func;
465 /* Signal and trap handling */
466 // unsigned count_SIGCHLD;
467 // unsigned handled_SIGCHLD;
468 /* which signals have non-DFL handler (even with no traps set)? */
469 unsigned non_DFL_mask;
470 char **traps; /* char *traps[NSIG] */
471 sigset_t blocked_set;
472 sigset_t inherited_set;
474 unsigned long memleak_value;
477 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
478 #if ENABLE_FEATURE_SH_STANDALONE
479 struct nofork_save_area nofork_save;
482 sigjmp_buf toplevel_jb;
485 #define G (*ptr_to_globals)
486 /* Not #defining name to G.name - this quickly gets unwieldy
487 * (too many defines). Also, I actually prefer to see when a variable
488 * is global, thus "G." prefix is a useful hint */
489 #define INIT_G() do { \
490 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
494 /* Function prototypes for builtins */
495 static int builtin_cd(char **argv);
496 static int builtin_echo(char **argv);
497 static int builtin_eval(char **argv);
498 static int builtin_exec(char **argv);
499 static int builtin_exit(char **argv);
500 static int builtin_export(char **argv);
502 static int builtin_fg_bg(char **argv);
503 static int builtin_jobs(char **argv);
506 static int builtin_help(char **argv);
509 static int builtin_memleak(char **argv);
511 static int builtin_pwd(char **argv);
512 static int builtin_read(char **argv);
513 static int builtin_set(char **argv);
514 static int builtin_shift(char **argv);
515 static int builtin_source(char **argv);
516 static int builtin_test(char **argv);
517 static int builtin_trap(char **argv);
518 static int builtin_true(char **argv);
519 static int builtin_umask(char **argv);
520 static int builtin_unset(char **argv);
521 static int builtin_wait(char **argv);
522 #if ENABLE_HUSH_LOOPS
523 static int builtin_break(char **argv);
524 static int builtin_continue(char **argv);
527 /* Table of built-in functions. They can be forked or not, depending on
528 * context: within pipes, they fork. As simple commands, they do not.
529 * When used in non-forking context, they can change global variables
530 * in the parent shell process. If forked, of course they cannot.
531 * For example, 'unset foo | whatever' will parse and run, but foo will
532 * still be set at the end. */
533 struct built_in_command {
535 int (*function)(char **argv);
538 #define BLTIN(cmd, func, help) { cmd, func, help }
540 #define BLTIN(cmd, func, help) { cmd, func }
544 /* For now, echo and test are unconditionally enabled.
545 * Maybe make it configurable? */
546 static const struct built_in_command bltins[] = {
547 BLTIN("." , builtin_source , "Run commands in a file"),
548 BLTIN(":" , builtin_true , "No-op"),
549 BLTIN("[" , builtin_test , "Test condition"),
551 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
553 #if ENABLE_HUSH_LOOPS
554 BLTIN("break" , builtin_break , "Exit from a loop"),
556 BLTIN("cd" , builtin_cd , "Change directory"),
557 #if ENABLE_HUSH_LOOPS
558 BLTIN("continue", builtin_continue, "Start new loop iteration"),
560 BLTIN("echo" , builtin_echo , "Write to stdout"),
561 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
562 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
563 BLTIN("exit" , builtin_exit , "Exit"),
564 BLTIN("export" , builtin_export , "Set environment variable"),
566 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
569 BLTIN("help" , builtin_help , "List shell built-in commands"),
572 BLTIN("jobs" , builtin_jobs , "List active jobs"),
575 BLTIN("memleak" , builtin_memleak , "Debug tool"),
577 BLTIN("pwd" , builtin_pwd , "Print current directory"),
578 BLTIN("read" , builtin_read , "Input environment variable"),
579 // BLTIN("return" , builtin_return , "Return from a function"),
580 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
581 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
582 BLTIN("test" , builtin_test , "Test condition"),
583 BLTIN("trap" , builtin_trap , "Trap signals"),
584 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
585 BLTIN("umask" , builtin_umask , "Set file creation mask"),
586 BLTIN("unset" , builtin_unset , "Unset environment variable"),
587 BLTIN("wait" , builtin_wait , "Wait for process"),
594 /* prevent disasters with G.debug_indent < 0 */
595 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
596 # define debug_enter() (G.debug_indent++)
597 # define debug_leave() (G.debug_indent--)
599 # define indent() ((void)0)
600 # define debug_enter() ((void)0)
601 # define debug_leave() ((void)0)
605 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
608 #ifndef debug_printf_parse
609 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
612 #ifndef debug_printf_exec
613 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
616 #ifndef debug_printf_env
617 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
620 #ifndef debug_printf_jobs
621 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
622 # define DEBUG_JOBS 1
624 # define DEBUG_JOBS 0
627 #ifndef debug_printf_expand
628 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
629 # define DEBUG_EXPAND 1
631 # define DEBUG_EXPAND 0
634 #ifndef debug_printf_glob
635 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
636 # define DEBUG_GLOB 1
638 # define DEBUG_GLOB 0
641 #ifndef debug_printf_list
642 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
645 #ifndef debug_printf_subst
646 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
649 #ifndef debug_printf_clean
650 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
651 # define DEBUG_CLEAN 1
653 # define DEBUG_CLEAN 0
657 static void debug_print_strings(const char *prefix, char **vv)
660 fprintf(stderr, "%s:\n", prefix);
662 fprintf(stderr, " '%s'\n", *vv++);
665 #define debug_print_strings(prefix, vv) ((void)0)
669 /* Leak hunting. Use hush_leaktool.sh for post-processing.
672 static void *xxmalloc(int lineno, size_t size)
674 void *ptr = xmalloc((size + 0xff) & ~0xff);
675 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
678 static void *xxrealloc(int lineno, void *ptr, size_t size)
680 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
681 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
684 static char *xxstrdup(int lineno, const char *str)
686 char *ptr = xstrdup(str);
687 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
690 static void xxfree(void *ptr)
692 fdprintf(2, "free %p\n", ptr);
695 #define xmalloc(s) xxmalloc(__LINE__, s)
696 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
697 #define xstrdup(s) xxstrdup(__LINE__, s)
698 #define free(p) xxfree(p)
702 /* Syntax and runtime errors. They always abort scripts.
703 * In interactive use they usually discard unparsed and/or unexecuted commands
704 * and return to the prompt.
705 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
708 # define die_if_script(lineno, fmt...) die_if_script(fmt)
709 # define syntax_error(lineno, msg) syntax_error(msg)
710 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
711 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
712 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
713 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
716 static void die_if_script(unsigned lineno, const char *fmt, ...)
721 bb_error_msg("hush.c:%u", lineno);
724 bb_verror_msg(fmt, p, NULL);
726 if (!G_interactive_fd)
730 static void syntax_error(unsigned lineno, const char *msg)
733 die_if_script(lineno, "syntax error: %s", msg);
735 die_if_script(lineno, "syntax error", NULL);
738 static void syntax_error_at(unsigned lineno, const char *msg)
740 die_if_script(lineno, "syntax error at '%s'", msg);
743 /* It so happens that all such cases are totally fatal
744 * even if shell is interactive: EOF while looking for closing
745 * delimiter. There is nowhere to read stuff from after that,
746 * it's EOF! The only choice is to terminate.
748 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
749 static void syntax_error_unterm_ch(unsigned lineno, char ch)
754 die_if_script(lineno, "syntax error: unterminated %s", msg);
758 static void syntax_error_unterm_str(unsigned lineno, const char *s)
760 die_if_script(lineno, "syntax error: unterminated %s", s);
763 static void syntax_error_unexpected_ch(unsigned lineno, char ch)
768 die_if_script(lineno, "syntax error: unexpected %s", msg);
772 # undef die_if_script
774 # undef syntax_error_at
775 # undef syntax_error_unterm_ch
776 # undef syntax_error_unterm_str
777 # undef syntax_error_unexpected_ch
779 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
780 # define syntax_error(msg) syntax_error(__LINE__, msg)
781 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
782 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
783 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
784 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
790 static int glob_needed(const char *s)
795 if (*s == '*' || *s == '[' || *s == '?')
802 static int is_well_formed_var_name(const char *s, char terminator)
804 if (!s || !(isalpha(*s) || *s == '_'))
807 while (isalnum(*s) || *s == '_')
809 return *s == terminator;
812 /* Replace each \x with x in place, return ptr past NUL. */
813 static char *unbackslash(char *src)
819 if ((*dst++ = *src++) == '\0')
825 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
846 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
847 v[count1 + count2] = NULL;
850 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
854 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
856 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
857 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
860 #define add_strings_to_strings(strings, add, need_to_dup) \
861 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
864 static char **add_string_to_strings(char **strings, char *add)
869 return add_strings_to_strings(strings, v, /*dup:*/ 0);
872 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
874 char **ptr = add_string_to_strings(strings, add);
875 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
878 #define add_string_to_strings(strings, add) \
879 xx_add_string_to_strings(__LINE__, strings, add)
882 static void putenv_all(char **strings)
887 debug_printf_env("putenv '%s'\n", *strings);
892 static char **putenv_all_and_save_old(char **strings)
902 eq = strchr(*strings, '=');
905 v = getenv(*strings);
908 /* v points to VAL in VAR=VAL, go back to VAR */
909 v -= (eq - *strings) + 1;
910 old = add_string_to_strings(old, v);
919 static void free_strings_and_unsetenv(char **strings, int unset)
929 debug_printf_env("unsetenv '%s'\n", *v);
937 static void free_strings(char **strings)
939 free_strings_and_unsetenv(strings, 0);
943 /* Basic theory of signal handling in shell
944 * ========================================
945 * This does not describe what hush does, rather, it is current understanding
946 * what it _should_ do. If it doesn't, it's a bug.
947 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
949 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
950 * is finished or backgrounded. It is the same in interactive and
951 * non-interactive shells, and is the same regardless of whether
952 * a user trap handler is installed or a shell special one is in effect.
953 * ^C or ^Z from keyboard seem to execute "at once" because it usually
954 * backgrounds (i.e. stops) or kills all members of currently running
957 * Wait builtin in interruptible by signals for which user trap is set
958 * or by SIGINT in interactive shell.
960 * Trap handlers will execute even within trap handlers. (right?)
962 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
964 * If job control is off, backgrounded commands ("cmd &")
965 * have SIGINT, SIGQUIT set to SIG_IGN.
967 * Commands run in command substitution ("`cmd`")
968 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
970 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
971 * by the shell from its parent.
973 * Siganls which differ from SIG_DFL action
974 * (note: child (i.e., [v]forked) shell is not an interactive shell):
977 * SIGTERM (interactive): ignore
978 * SIGHUP (interactive):
979 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
980 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
981 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
982 * that all pipe members are stopped) (right?)
983 * SIGINT (interactive): wait for last pipe, ignore the rest
984 * of the command line, show prompt. NB: ^C does not send SIGINT
985 * to interactive shell while shell is waiting for a pipe,
986 * since shell is bg'ed (is not in foreground process group).
987 * (check/expand this)
988 * Example 1: this waits 5 sec, but does not execute ls:
989 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
990 * Example 2: this does not wait and does not execute ls:
991 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
992 * Example 3: this does not wait 5 sec, but executes ls:
993 * "sleep 5; ls -l" + press ^C
995 * (What happens to signals which are IGN on shell start?)
996 * (What happens with signal mask on shell start?)
998 * Implementation in hush
999 * ======================
1000 * We use in-kernel pending signal mask to determine which signals were sent.
1001 * We block all signals which we don't want to take action immediately,
1002 * i.e. we block all signals which need to have special handling as described
1003 * above, and all signals which have traps set.
1004 * After each pipe execution, we extract any pending signals via sigtimedwait()
1007 * unsigned non_DFL_mask: a mask of such "special" signals
1008 * sigset_t blocked_set: current blocked signal set
1011 * clear bit in blocked_set unless it is also in non_DFL_mask
1012 * "trap 'cmd' SIGxxx":
1013 * set bit in blocked_set (even if 'cmd' is '')
1014 * after [v]fork, if we plan to be a shell:
1015 * nothing for {} child shell (say, "true | { true; true; } | true")
1016 * unset all traps if () shell.
1017 * after [v]fork, if we plan to exec:
1018 * POSIX says pending signal mask is cleared in child - no need to clear it.
1019 * Restore blocked signal set to one inherited by shell just prior to exec.
1021 * Note: as a result, we do not use signal handlers much. The only uses
1022 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
1023 * and to restore tty pgrp on signal-induced exit.
1026 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1028 // G.count_SIGCHLD++;
1031 static int check_and_run_traps(int sig)
1033 static const struct timespec zero_timespec = { 0, 0 };
1034 smalluint save_rcode;
1040 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1045 if (G.traps && G.traps[sig]) {
1046 if (G.traps[sig][0]) {
1047 /* We have user-defined handler */
1048 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1049 save_rcode = G.last_exitcode;
1052 G.last_exitcode = save_rcode;
1053 } /* else: "" trap, ignoring signal */
1056 /* not a trap: special action */
1059 // G.count_SIGCHLD++;
1068 default: /* ignored: */
1069 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1078 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1079 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1080 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1081 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1083 /* Restores tty foreground process group, and exits.
1084 * May be called as signal handler for fatal signal
1085 * (will faithfully resend signal to itself, producing correct exit state)
1086 * or called directly with -EXITCODE.
1087 * We also call it if xfunc is exiting. */
1088 static void sigexit(int sig) NORETURN;
1089 static void sigexit(int sig)
1091 /* Disable all signals: job control, SIGPIPE, etc. */
1092 sigprocmask_allsigs(SIG_BLOCK);
1094 /* Careful: we can end up here after [v]fork. Do not restore
1095 * tty pgrp then, only top-level shell process does that */
1096 if (G_interactive_fd && getpid() == G.root_pid)
1097 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1099 /* Not a signal, just exit */
1103 kill_myself_with_sig(sig); /* does not return */
1107 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1108 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1112 /* Restores tty foreground process group, and exits. */
1113 static void hush_exit(int exitcode) NORETURN;
1114 static void hush_exit(int exitcode)
1116 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1117 /* Prevent recursion:
1118 * trap "echo Hi; exit" EXIT; exit
1120 char *argv[] = { NULL, G.traps[0], NULL };
1128 fflush(NULL); /* flush all streams */
1129 sigexit(- (exitcode & 0xff));
1136 static const char *set_cwd(void)
1138 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1139 * we must not try to free(bb_msg_unknown) */
1140 if (G.cwd == bb_msg_unknown)
1142 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1144 G.cwd = bb_msg_unknown;
1149 /* Get/check local shell variables */
1150 static struct variable *get_local_var(const char *name)
1152 struct variable *cur;
1158 for (cur = G.top_var; cur; cur = cur->next) {
1159 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1165 static const char *get_local_var_value(const char *src)
1167 struct variable *var = get_local_var(src);
1169 return strchr(var->varstr, '=') + 1;
1173 /* str holds "NAME=VAL" and is expected to be malloced.
1174 * We take ownership of it.
1178 * -1: if NAME is set, leave export status alone
1179 * if NAME is not set, do not export
1180 * flg_read_only is set only when we handle -R var=val
1183 #define set_local_var(str, flg_export, flg_read_only) \
1184 set_local_var(str, flg_export)
1186 static int set_local_var(char *str, int flg_export, int flg_read_only)
1188 struct variable *cur;
1192 value = strchr(str, '=');
1193 if (!value) { /* not expected to ever happen? */
1198 name_len = value - str + 1; /* including '=' */
1199 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1201 if (strncmp(cur->varstr, str, name_len) != 0) {
1203 /* Bail out. Note that now cur points
1204 * to last var in linked list */
1210 /* We found an existing var with this name */
1212 if (cur->flg_read_only) {
1216 bb_error_msg("%s: readonly variable", str);
1220 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1221 unsetenv(str); /* just in case */
1223 if (strcmp(cur->varstr, str) == 0) {
1228 if (cur->max_len >= strlen(str)) {
1229 /* This one is from startup env, reuse space */
1230 strcpy(cur->varstr, str);
1233 /* max_len == 0 signifies "malloced" var, which we can
1234 * (and has to) free */
1238 goto set_str_and_exp;
1241 /* Not found - create next variable struct */
1242 cur->next = xzalloc(sizeof(*cur));
1248 cur->flg_read_only = flg_read_only;
1251 if (flg_export == 1)
1252 cur->flg_export = 1;
1253 if (cur->flg_export) {
1254 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1255 return putenv(cur->varstr);
1260 static int unset_local_var(const char *name)
1262 struct variable *cur;
1263 struct variable *prev = prev; /* for gcc */
1267 return EXIT_SUCCESS;
1268 name_len = strlen(name);
1271 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1272 if (cur->flg_read_only) {
1273 bb_error_msg("%s: readonly variable", name);
1274 return EXIT_FAILURE;
1276 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1277 * is ro, and we cannot reach this code on the 1st pass */
1278 prev->next = cur->next;
1279 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1280 bb_unsetenv(cur->varstr);
1284 return EXIT_SUCCESS;
1289 return EXIT_SUCCESS;
1292 #if ENABLE_SH_MATH_SUPPORT
1293 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1294 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1295 static char *endofname(const char *name)
1303 if (!is_in_name(*p))
1309 static void arith_set_local_var(const char *name, const char *val, int flags)
1311 /* arith code doesnt malloc space, so do it for it */
1312 char *var = xasprintf("%s=%s", name, val);
1313 set_local_var(var, flags, 0);
1321 static int static_get(struct in_str *i)
1330 static int static_peek(struct in_str *i)
1335 #if ENABLE_HUSH_INTERACTIVE
1337 static void cmdedit_set_initial_prompt(void)
1339 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1340 G.PS1 = getenv("PS1");
1347 static const char* setup_prompt_string(int promptmode)
1349 const char *prompt_str;
1350 debug_printf("setup_prompt_string %d ", promptmode);
1351 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1352 /* Set up the prompt */
1353 if (promptmode == 0) { /* PS1 */
1355 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1360 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1361 debug_printf("result '%s'\n", prompt_str);
1365 static void get_user_input(struct in_str *i)
1368 const char *prompt_str;
1370 prompt_str = setup_prompt_string(i->promptmode);
1371 #if ENABLE_FEATURE_EDITING
1372 /* Enable command line editing only while a command line
1373 * is actually being read */
1376 /* buglet: SIGINT will not make new prompt to appear _at once_,
1377 * only after <Enter>. (^C will work) */
1378 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1379 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1380 check_and_run_traps(0);
1381 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1382 i->eof_flag = (r < 0);
1383 if (i->eof_flag) { /* EOF/error detected */
1384 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1385 G.user_input_buf[1] = '\0';
1390 fputs(prompt_str, stdout);
1392 G.user_input_buf[0] = r = fgetc(i->file);
1393 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1394 //do we need check_and_run_traps(0)? (maybe only if stdin)
1395 } while (G.flag_SIGINT);
1396 i->eof_flag = (r == EOF);
1398 i->p = G.user_input_buf;
1401 #endif /* INTERACTIVE */
1403 /* This is the magic location that prints prompts
1404 * and gets data back from the user */
1405 static int file_get(struct in_str *i)
1409 /* If there is data waiting, eat it up */
1410 if (i->p && *i->p) {
1411 #if ENABLE_HUSH_INTERACTIVE
1415 if (i->eof_flag && !*i->p)
1417 /* note: ch is never NUL */
1419 /* need to double check i->file because we might be doing something
1420 * more complicated by now, like sourcing or substituting. */
1421 #if ENABLE_HUSH_INTERACTIVE
1422 if (G_interactive_fd && i->promptme && i->file == stdin) {
1425 } while (!*i->p); /* need non-empty line */
1426 i->promptmode = 1; /* PS2 */
1431 do ch = fgetc(i->file); while (ch == '\0');
1433 debug_printf("file_get: got '%c' %d\n", ch, ch);
1434 #if ENABLE_HUSH_INTERACTIVE
1441 /* All callers guarantee this routine will never
1442 * be used right after a newline, so prompting is not needed.
1444 static int file_peek(struct in_str *i)
1447 if (i->p && *i->p) {
1448 if (i->eof_flag && !i->p[1])
1451 /* note: ch is never NUL */
1453 do ch = fgetc(i->file); while (ch == '\0');
1454 i->eof_flag = (ch == EOF);
1455 i->peek_buf[0] = ch;
1456 i->peek_buf[1] = '\0';
1458 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1462 static void setup_file_in_str(struct in_str *i, FILE *f)
1464 i->peek = file_peek;
1466 #if ENABLE_HUSH_INTERACTIVE
1468 i->promptmode = 0; /* PS1 */
1474 static void setup_string_in_str(struct in_str *i, const char *s)
1476 i->peek = static_peek;
1477 i->get = static_get;
1478 #if ENABLE_HUSH_INTERACTIVE
1480 i->promptmode = 0; /* PS1 */
1490 #define B_CHUNK (32 * sizeof(char*))
1492 static void o_reset_to_empty_unquoted(o_string *o)
1500 static void o_free(o_string *o)
1503 memset(o, 0, sizeof(*o));
1506 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1511 static void o_grow_by(o_string *o, int len)
1513 if (o->length + len > o->maxlen) {
1514 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1515 o->data = xrealloc(o->data, 1 + o->maxlen);
1519 static void o_addchr(o_string *o, int ch)
1521 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1523 o->data[o->length] = ch;
1525 o->data[o->length] = '\0';
1528 static void o_addblock(o_string *o, const char *str, int len)
1531 memcpy(&o->data[o->length], str, len);
1533 o->data[o->length] = '\0';
1537 static void o_addstr(o_string *o, const char *str)
1539 o_addblock(o, str, strlen(str));
1541 static void nommu_addchr(o_string *o, int ch)
1547 #define nommu_addchr(o, str) ((void)0)
1550 static void o_addstr_with_NUL(o_string *o, const char *str)
1552 o_addblock(o, str, strlen(str) + 1);
1555 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1560 && (*str != '*' && *str != '?' && *str != '[')
1568 /* My analysis of quoting semantics tells me that state information
1569 * is associated with a destination, not a source.
1571 static void o_addqchr(o_string *o, int ch)
1574 char *found = strchr("*?[\\", ch);
1579 o->data[o->length] = '\\';
1582 o->data[o->length] = ch;
1584 o->data[o->length] = '\0';
1587 static void o_addQchr(o_string *o, int ch)
1590 if (o->o_escape && strchr("*?[\\", ch)) {
1592 o->data[o->length] = '\\';
1596 o->data[o->length] = ch;
1598 o->data[o->length] = '\0';
1601 static void o_addQstr(o_string *o, const char *str, int len)
1604 o_addblock(o, str, len);
1610 int ordinary_cnt = strcspn(str, "*?[\\");
1611 if (ordinary_cnt > len) /* paranoia */
1613 o_addblock(o, str, ordinary_cnt);
1614 if (ordinary_cnt == len)
1616 str += ordinary_cnt;
1617 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1621 if (ch) { /* it is necessarily one of "*?[\\" */
1623 o->data[o->length] = '\\';
1627 o->data[o->length] = ch;
1629 o->data[o->length] = '\0';
1633 /* A special kind of o_string for $VAR and `cmd` expansion.
1634 * It contains char* list[] at the beginning, which is grown in 16 element
1635 * increments. Actual string data starts at the next multiple of 16 * (char*).
1636 * list[i] contains an INDEX (int!) into this string data.
1637 * It means that if list[] needs to grow, data needs to be moved higher up
1638 * but list[i]'s need not be modified.
1639 * NB: remembering how many list[i]'s you have there is crucial.
1640 * o_finalize_list() operation post-processes this structure - calculates
1641 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1643 #if DEBUG_EXPAND || DEBUG_GLOB
1644 static void debug_print_list(const char *prefix, o_string *o, int n)
1646 char **list = (char**)o->data;
1647 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1651 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1652 prefix, list, n, string_start, o->length, o->maxlen);
1655 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1656 o->data + (int)list[i] + string_start,
1657 o->data + (int)list[i] + string_start);
1661 const char *p = o->data + (int)list[n - 1] + string_start;
1663 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1667 #define debug_print_list(prefix, o, n) ((void)0)
1670 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1671 * in list[n] so that it points past last stored byte so far.
1672 * It returns n+1. */
1673 static int o_save_ptr_helper(o_string *o, int n)
1675 char **list = (char**)o->data;
1679 if (!o->has_empty_slot) {
1680 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1681 string_len = o->length - string_start;
1682 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1683 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1684 /* list[n] points to string_start, make space for 16 more pointers */
1685 o->maxlen += 0x10 * sizeof(list[0]);
1686 o->data = xrealloc(o->data, o->maxlen + 1);
1687 list = (char**)o->data;
1688 memmove(list + n + 0x10, list + n, string_len);
1689 o->length += 0x10 * sizeof(list[0]);
1691 debug_printf_list("list[%d]=%d string_start=%d\n",
1692 n, string_len, string_start);
1695 /* We have empty slot at list[n], reuse without growth */
1696 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1697 string_len = o->length - string_start;
1698 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1699 n, string_len, string_start);
1700 o->has_empty_slot = 0;
1702 list[n] = (char*)(ptrdiff_t)string_len;
1706 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1707 static int o_get_last_ptr(o_string *o, int n)
1709 char **list = (char**)o->data;
1710 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1712 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1715 /* o_glob performs globbing on last list[], saving each result
1716 * as a new list[]. */
1717 static int o_glob(o_string *o, int n)
1723 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1725 return o_save_ptr_helper(o, n);
1726 pattern = o->data + o_get_last_ptr(o, n);
1727 debug_printf_glob("glob pattern '%s'\n", pattern);
1728 if (!glob_needed(pattern)) {
1730 o->length = unbackslash(pattern) - o->data;
1731 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1732 return o_save_ptr_helper(o, n);
1735 memset(&globdata, 0, sizeof(globdata));
1736 gr = glob(pattern, 0, NULL, &globdata);
1737 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1738 if (gr == GLOB_NOSPACE)
1739 bb_error_msg_and_die("out of memory during glob");
1740 if (gr == GLOB_NOMATCH) {
1741 globfree(&globdata);
1744 if (gr != 0) { /* GLOB_ABORTED ? */
1745 //TODO: testcase for bad glob pattern behavior
1746 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1748 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1749 char **argv = globdata.gl_pathv;
1750 o->length = pattern - o->data; /* "forget" pattern */
1752 o_addstr_with_NUL(o, *argv);
1753 n = o_save_ptr_helper(o, n);
1759 globfree(&globdata);
1761 debug_print_list("o_glob returning", o, n);
1765 /* If o->o_glob == 1, glob the string so far remembered.
1766 * Otherwise, just finish current list[] and start new */
1767 static int o_save_ptr(o_string *o, int n)
1769 if (o->o_glob) { /* if globbing is requested */
1770 /* If o->has_empty_slot, list[n] was already globbed
1771 * (if it was requested back then when it was filled)
1772 * so don't do that again! */
1773 if (!o->has_empty_slot)
1774 return o_glob(o, n); /* o_save_ptr_helper is inside */
1776 return o_save_ptr_helper(o, n);
1779 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1780 static char **o_finalize_list(o_string *o, int n)
1785 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1787 debug_print_list("finalized", o, n);
1788 debug_printf_expand("finalized n:%d\n", n);
1789 list = (char**)o->data;
1790 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1794 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1800 /* Expansion can recurse */
1801 #if ENABLE_HUSH_TICK
1802 static int process_command_subs(o_string *dest, const char *s);
1804 static char *expand_string_to_string(const char *str);
1806 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1807 parse_stream_dquoted(dest, input, dquote_end)
1809 static int parse_stream_dquoted(o_string *as_string,
1811 struct in_str *input,
1814 /* expand_strvec_to_strvec() takes a list of strings, expands
1815 * all variable references within and returns a pointer to
1816 * a list of expanded strings, possibly with larger number
1817 * of strings. (Think VAR="a b"; echo $VAR).
1818 * This new list is allocated as a single malloc block.
1819 * NULL-terminated list of char* pointers is at the beginning of it,
1820 * followed by strings themself.
1821 * Caller can deallocate entire list by single free(list). */
1823 /* Store given string, finalizing the word and starting new one whenever
1824 * we encounter IFS char(s). This is used for expanding variable values.
1825 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1826 static int expand_on_ifs(o_string *output, int n, const char *str)
1829 int word_len = strcspn(str, G.ifs);
1831 if (output->o_escape || !output->o_glob)
1832 o_addQstr(output, str, word_len);
1833 else /* protect backslashes against globbing up :) */
1834 o_addblock_duplicate_backslash(output, str, word_len);
1837 if (!*str) /* EOL - do not finalize word */
1839 o_addchr(output, '\0');
1840 debug_print_list("expand_on_ifs", output, n);
1841 n = o_save_ptr(output, n);
1842 str += strspn(str, G.ifs); /* skip ifs chars */
1844 debug_print_list("expand_on_ifs[1]", output, n);
1848 /* Helper to expand $((...)) and heredoc body. These act as if
1849 * they are in double quotes, with the exception that they are not :).
1850 * Just the rules are similar: "expand only $var and `cmd`"
1852 * Returns malloced string.
1853 * As an optimization, we return NULL if expansion is not needed.
1855 static char *expand_pseudo_dquoted(const char *str)
1858 struct in_str input;
1859 o_string dest = NULL_O_STRING;
1861 if (strchr(str, '$') == NULL
1862 #if ENABLE_HUSH_TICK
1863 && strchr(str, '`') == NULL
1869 /* We need to expand. Example:
1870 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1872 setup_string_in_str(&input, str);
1873 parse_stream_dquoted(NULL, &dest, &input, EOF);
1874 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1875 exp_str = expand_string_to_string(dest.data);
1876 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1877 o_free_unsafe(&dest);
1881 /* Expand all variable references in given string, adding words to list[]
1882 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1883 * to be filled). This routine is extremely tricky: has to deal with
1884 * variables/parameters with whitespace, $* and $@, and constructs like
1885 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1886 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1888 /* or_mask is either 0 (normal case) or 0x80
1889 * (expansion of right-hand side of assignment == 1-element expand.
1890 * It will also do no globbing, and thus we must not backslash-quote!) */
1892 char first_ch, ored_ch;
1900 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1901 debug_print_list("expand_vars_to_list", output, n);
1902 n = o_save_ptr(output, n);
1903 debug_print_list("expand_vars_to_list[0]", output, n);
1905 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1906 #if ENABLE_HUSH_TICK
1907 o_string subst_result = NULL_O_STRING;
1909 #if ENABLE_SH_MATH_SUPPORT
1910 char arith_buf[sizeof(arith_t)*3 + 2];
1912 o_addblock(output, arg, p - arg);
1913 debug_print_list("expand_vars_to_list[1]", output, n);
1915 p = strchr(p, SPECIAL_VAR_SYMBOL);
1917 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1918 /* "$@" is special. Even if quoted, it can still
1919 * expand to nothing (not even an empty string) */
1920 if ((first_ch & 0x7f) != '@')
1921 ored_ch |= first_ch;
1924 switch (first_ch & 0x7f) {
1925 /* Highest bit in first_ch indicates that var is double-quoted */
1927 val = utoa(G.root_pid);
1929 case '!': /* bg pid */
1930 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1932 case '?': /* exitcode */
1933 val = utoa(G.last_exitcode);
1935 case '#': /* argc */
1936 if (arg[1] != SPECIAL_VAR_SYMBOL)
1937 /* actually, it's a ${#var} */
1939 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1944 if (!G.global_argv[i])
1946 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1947 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1948 smallint sv = output->o_escape;
1949 /* unquoted var's contents should be globbed, so don't escape */
1950 output->o_escape = 0;
1951 while (G.global_argv[i]) {
1952 n = expand_on_ifs(output, n, G.global_argv[i]);
1953 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1954 if (G.global_argv[i++][0] && G.global_argv[i]) {
1955 /* this argv[] is not empty and not last:
1956 * put terminating NUL, start new word */
1957 o_addchr(output, '\0');
1958 debug_print_list("expand_vars_to_list[2]", output, n);
1959 n = o_save_ptr(output, n);
1960 debug_print_list("expand_vars_to_list[3]", output, n);
1963 output->o_escape = sv;
1965 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1966 * and in this case should treat it like '$*' - see 'else...' below */
1967 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1969 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1970 if (++i >= G.global_argc)
1972 o_addchr(output, '\0');
1973 debug_print_list("expand_vars_to_list[4]", output, n);
1974 n = o_save_ptr(output, n);
1976 } else { /* quoted $*: add as one word */
1978 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1979 if (!G.global_argv[++i])
1982 o_addchr(output, G.ifs[0]);
1986 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1987 /* "Empty variable", used to make "" etc to not disappear */
1991 #if ENABLE_HUSH_TICK
1992 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1995 //TODO: can we just stuff it into "output" directly?
1996 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1997 process_command_subs(&subst_result, arg);
1998 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1999 val = subst_result.data;
2002 #if ENABLE_SH_MATH_SUPPORT
2003 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2004 arith_eval_hooks_t hooks;
2009 arg++; /* skip '+' */
2010 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2011 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2013 exp_str = expand_pseudo_dquoted(arg);
2014 hooks.lookupvar = get_local_var_value;
2015 hooks.setvar = arith_set_local_var;
2016 hooks.endofname = endofname;
2017 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2021 const char *msg = "error in arithmetic";
2024 msg = "exponent less than 0";
2027 msg = "divide by 0";
2030 msg = "expression recursion loop detected";
2035 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2036 sprintf(arith_buf, arith_t_fmt, res);
2041 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2043 bool exp_len = false;
2044 bool exp_null = false;
2046 char exp_save = exp_save; /* for compiler */
2047 char exp_op = exp_op; /* for compiler */
2048 char *exp_word = exp_word; /* for compiler */
2052 arg[0] = first_ch & 0x7f;
2054 /* prepare for expansions */
2055 if (var[0] == '#') {
2056 /* handle length expansion ${#var} */
2060 /* maybe handle parameter expansion */
2061 exp_off = strcspn(var, ":-=+?%#");
2065 exp_save = var[exp_off];
2066 exp_null = exp_save == ':';
2067 exp_word = var + exp_off;
2070 exp_op = *exp_word++;
2071 var[exp_off] = '\0';
2075 /* lookup the variable in question */
2076 if (isdigit(var[0])) {
2077 /* handle_dollar() should have vetted var for us */
2079 if (i < G.global_argc)
2080 val = G.global_argv[i];
2081 /* else val remains NULL: $N with too big N */
2083 val = get_local_var_value(var);
2085 /* handle any expansions */
2087 debug_printf_expand("expand: length of '%s' = ", val);
2088 val = utoa(val ? strlen(val) : 0);
2089 debug_printf_expand("%s\n", val);
2090 } else if (exp_off) {
2091 if (exp_op == '%' || exp_op == '#') {
2093 /* we need to do a pattern match */
2096 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2097 if (exp_op == *exp_word) /* ## or %% */
2099 val = dyn_val = xstrdup(val);
2100 loc = scan(dyn_val, exp_word, zero);
2107 /* we need to do an expansion */
2108 int exp_test = (!val || (exp_null && !val[0]));
2110 exp_test = !exp_test;
2111 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2112 exp_null ? "true" : "false", exp_test);
2114 if (exp_op == '?') {
2115 //TODO: how interactive bash aborts expansion mid-command?
2116 /* ${var?[error_msg_if_unset]} */
2117 /* ${var:?[error_msg_if_unset_or_null]} */
2118 /* mimic bash message */
2119 die_if_script("%s: %s",
2121 exp_word[0] ? exp_word : "parameter null or not set"
2127 if (exp_op == '=') {
2128 /* ${var=[word]} or ${var:=[word]} */
2129 if (isdigit(var[0]) || var[0] == '#') {
2130 /* mimic bash message */
2131 die_if_script("$%s: cannot assign in this way", var);
2134 char *new_var = xasprintf("%s=%s", var, val);
2135 set_local_var(new_var, -1, 0);
2141 var[exp_off] = exp_save;
2145 #if ENABLE_HUSH_TICK
2148 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2149 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2151 /* unquoted var's contents should be globbed, so don't escape */
2152 smallint sv = output->o_escape;
2153 output->o_escape = 0;
2154 n = expand_on_ifs(output, n, val);
2156 output->o_escape = sv;
2158 } else { /* quoted $VAR, val will be appended below */
2159 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2162 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2164 o_addQstr(output, val, strlen(val));
2168 /* Do the check to avoid writing to a const string */
2169 if (*p != SPECIAL_VAR_SYMBOL)
2170 *p = SPECIAL_VAR_SYMBOL;
2172 #if ENABLE_HUSH_TICK
2173 o_free(&subst_result);
2176 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2179 debug_print_list("expand_vars_to_list[a]", output, n);
2180 /* this part is literal, and it was already pre-quoted
2181 * if needed (much earlier), do not use o_addQstr here! */
2182 o_addstr_with_NUL(output, arg);
2183 debug_print_list("expand_vars_to_list[b]", output, n);
2184 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2185 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2188 /* allow to reuse list[n] later without re-growth */
2189 output->has_empty_slot = 1;
2191 o_addchr(output, '\0');
2196 static char **expand_variables(char **argv, int or_mask)
2201 o_string output = NULL_O_STRING;
2203 if (or_mask & 0x100) {
2204 output.o_escape = 1; /* protect against globbing for "$var" */
2205 /* (unquoted $var will temporarily switch it off) */
2212 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2215 debug_print_list("expand_variables", &output, n);
2217 /* output.data (malloced in one block) gets returned in "list" */
2218 list = o_finalize_list(&output, n);
2219 debug_print_strings("expand_variables[1]", list);
2223 static char **expand_strvec_to_strvec(char **argv)
2225 return expand_variables(argv, 0x100);
2228 /* Used for expansion of right hand of assignments */
2229 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2231 static char *expand_string_to_string(const char *str)
2233 char *argv[2], **list;
2235 argv[0] = (char*)str;
2237 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2239 if (!list[0] || list[1])
2240 bb_error_msg_and_die("BUG in varexp2");
2241 /* actually, just move string 2*sizeof(char*) bytes back */
2242 overlapping_strcpy((char*)list, list[0]);
2243 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2247 /* Used for "eval" builtin */
2248 static char* expand_strvec_to_string(char **argv)
2252 list = expand_variables(argv, 0x80);
2253 /* Convert all NULs to spaces */
2258 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2259 bb_error_msg_and_die("BUG in varexp3");
2260 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2264 overlapping_strcpy((char*)list, list[0]);
2265 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2269 static char **expand_assignments(char **argv, int count)
2273 /* Expand assignments into one string each */
2274 for (i = 0; i < count; i++) {
2275 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2283 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2285 static void reset_traps_to_defaults(void)
2293 for (sig = 0; sig < NSIG; sig++) {
2297 G.traps[sig] = NULL;
2298 /* There is no signal for 0 (EXIT) */
2301 /* there was a trap handler, we are removing it
2302 * (if sig has non-DFL handling,
2303 * we don't need to do anything) */
2304 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2306 sigdelset(&G.blocked_set, sig);
2310 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2315 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2316 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2318 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2319 char *heredoc_argv[4];
2320 struct variable *cur;
2321 #if ENABLE_HUSH_FUNCTIONS
2322 struct function *funcp;
2327 if (!g_argv0) { /* heredoc */
2328 argv = heredoc_argv;
2329 argv[0] = (char *) G.argv0_for_re_execing;
2330 argv[1] = (char *) "-<";
2331 argv[2] = (char *) s;
2333 pp = &argv[3]; /* used as pointer to empty environment */
2337 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2338 , (unsigned) G.root_pid
2339 , (unsigned) G.last_bg_pid
2340 , (unsigned) G.last_exitcode
2341 USE_HUSH_LOOPS(, G.depth_of_loop)
2343 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2344 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2347 for (cur = G.top_var; cur; cur = cur->next) {
2348 if (!cur->flg_export || cur->flg_read_only)
2351 #if ENABLE_HUSH_FUNCTIONS
2352 for (funcp = G.top_func; funcp; funcp = funcp->next)
2358 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2359 *pp++ = (char *) G.argv0_for_re_execing;
2361 for (cur = G.top_var; cur; cur = cur->next) {
2362 if (cur->varstr == hush_version_str)
2364 if (cur->flg_read_only) {
2365 *pp++ = (char *) "-R";
2366 *pp++ = cur->varstr;
2367 } else if (!cur->flg_export) {
2368 *pp++ = (char *) "-V";
2369 *pp++ = cur->varstr;
2372 #if ENABLE_HUSH_FUNCTIONS
2373 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2374 *pp++ = (char *) "-F";
2375 *pp++ = funcp->name;
2376 *pp++ = funcp->body_as_string;
2379 /* We can pass activated traps here. Say, -Tnn:trap_string
2381 * However, POSIX says that subshells reset signals with traps
2383 * I tested bash-3.2 and it not only does that with true subshells
2384 * of the form ( list ), but with any forked children shells.
2385 * I set trap "echo W" WINCH; and then tried:
2387 * { echo 1; sleep 20; echo 2; } &
2388 * while true; do echo 1; sleep 20; echo 2; break; done &
2389 * true | { echo 1; sleep 20; echo 2; } | cat
2391 * In all these cases sending SIGWINCH to the child shell
2392 * did not run the trap. If I add trap "echo V" WINCH;
2393 * _inside_ group (just before echo 1), it works.
2395 * I conclude it means we don't need to pass active traps here.
2396 * exec syscall below resets them to SIG_DFL for us.
2398 *pp++ = (char *) "-c";
2403 /* *pp = NULL; - is already there */
2407 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2408 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2409 execve(bb_busybox_exec_path, argv, pp);
2410 /* Fallback. Useful for init=/bin/hush usage etc */
2411 if (argv[0][0] == '/')
2412 execve(argv[0], argv, pp);
2413 xfunc_error_retval = 127;
2414 bb_error_msg_and_die("can't re-execute the shell");
2416 #endif /* !BB_MMU */
2419 static void setup_heredoc(struct redir_struct *redir)
2421 struct fd_pair pair;
2424 /* the _body_ of heredoc (misleading field name) */
2425 const char *heredoc = redir->rd_filename;
2432 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2433 expanded = expand_pseudo_dquoted(heredoc);
2437 len = strlen(heredoc);
2439 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2441 xmove_fd(pair.rd, redir->rd_fd);
2443 /* Try writing without forking. Newer kernels have
2444 * dynamically growing pipes. Must use non-blocking write! */
2447 written = write(pair.wr, heredoc, len);
2458 ndelay_off(pair.wr);
2460 /* Okay, pipe buffer was not big enough */
2461 /* Note: we must not create a stray child (bastard? :)
2462 * for the unsuspecting parent process. Child creates a grandchild
2463 * and exits before parent execs the process which consumes heredoc
2464 * (that exec happens after we return from this function) */
2467 bb_perror_msg_and_die("vfork");
2470 pid = BB_MMU ? fork() : vfork();
2472 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2476 close(redir->rd_fd); /* read side of the pipe */
2478 full_write(pair.wr, heredoc, len); /* may loop or block */
2481 /* Delegate blocking writes to another process */
2482 disable_restore_tty_pgrp_on_exit();
2483 xmove_fd(pair.wr, STDOUT_FILENO);
2484 re_execute_shell(&to_free, heredoc, NULL, NULL);
2488 enable_restore_tty_pgrp_on_exit();
2494 wait(NULL); /* wait till child has died */
2497 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2498 * and stderr if they are redirected. */
2499 static int setup_redirects(struct command *prog, int squirrel[])
2502 struct redir_struct *redir;
2504 for (redir = prog->redirects; redir; redir = redir->next) {
2505 if (redir->rd_type == REDIRECT_HEREDOC2) {
2506 /* rd_fd<<HERE case */
2507 if (squirrel && redir->rd_fd < 3) {
2508 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2510 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2512 debug_printf_parse("set heredoc '%s'\n",
2513 redir->rd_filename);
2514 setup_heredoc(redir);
2518 if (redir->rd_dup == REDIRFD_TO_FILE) {
2519 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2521 if (redir->rd_filename == NULL) {
2522 /* Something went wrong in the parse.
2523 * Pretend it didn't happen */
2524 bb_error_msg("bug in redirect parse");
2527 mode = redir_table[redir->rd_type].mode;
2528 p = expand_string_to_string(redir->rd_filename);
2529 openfd = open_or_warn(p, mode);
2532 /* this could get lost if stderr has been redirected, but
2533 * bash and ash both lose it as well (though zsh doesn't!) */
2534 //what the above comment tries to say?
2538 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2539 openfd = redir->rd_dup;
2542 if (openfd != redir->rd_fd) {
2543 if (squirrel && redir->rd_fd < 3) {
2544 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2546 if (openfd == REDIRFD_CLOSE) {
2547 /* "n>-" means "close me" */
2548 close(redir->rd_fd);
2550 xdup2(openfd, redir->rd_fd);
2551 if (redir->rd_dup == REDIRFD_TO_FILE)
2559 static void restore_redirects(int squirrel[])
2562 for (i = 0; i < 3; i++) {
2565 /* We simply die on error */
2572 static void free_pipe_list(struct pipe *head);
2574 /* Return code is the exit status of the pipe */
2575 static void free_pipe(struct pipe *pi)
2578 struct command *command;
2579 struct redir_struct *r, *rnext;
2582 if (pi->stopped_cmds > 0) /* why? */
2584 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2585 for (i = 0; i < pi->num_cmds; i++) {
2586 command = &pi->cmds[i];
2587 debug_printf_clean(" command %d:\n", i);
2588 if (command->argv) {
2589 for (a = 0, p = command->argv; *p; a++, p++) {
2590 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2592 free_strings(command->argv);
2593 command->argv = NULL;
2595 /* not "else if": on syntax error, we may have both! */
2596 if (command->group) {
2597 debug_printf_clean(" begin group (grp_type:%d)\n",
2599 free_pipe_list(command->group);
2600 debug_printf_clean(" end group\n");
2601 command->group = NULL;
2603 /* else is crucial here.
2604 * If group != NULL, child_func is meaningless */
2605 #if ENABLE_HUSH_FUNCTIONS
2606 else if (command->child_func) {
2607 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2608 command->child_func->parent_cmd = NULL;
2612 free(command->group_as_string);
2613 command->group_as_string = NULL;
2615 for (r = command->redirects; r; r = rnext) {
2616 debug_printf_clean(" redirect %d%s",
2617 r->rd_fd, redir_table[r->rd_type].descrip);
2618 /* guard against the case >$FOO, where foo is unset or blank */
2619 if (r->rd_filename) {
2620 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2621 free(r->rd_filename);
2622 r->rd_filename = NULL;
2624 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2628 command->redirects = NULL;
2630 free(pi->cmds); /* children are an array, they get freed all at once */
2638 static void free_pipe_list(struct pipe *head)
2640 struct pipe *pi, *next;
2642 for (pi = head; pi; pi = next) {
2644 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2647 debug_printf_clean("pipe followup code %d\n", pi->followup);
2649 /*pi->next = NULL;*/
2655 static int run_list(struct pipe *pi);
2657 #define parse_stream(pstring, input, end_trigger) \
2658 parse_stream(input, end_trigger)
2660 static struct pipe *parse_stream(char **pstring,
2661 struct in_str *input,
2663 static void parse_and_run_string(const char *s);
2666 static const struct built_in_command* find_builtin(const char *name)
2668 const struct built_in_command *x;
2669 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2670 if (strcmp(name, x->cmd) != 0)
2672 debug_printf_exec("found builtin '%s'\n", name);
2678 #if ENABLE_HUSH_FUNCTIONS
2679 static const struct function *find_function(const char *name)
2681 const struct function *funcp = G.top_func;
2683 if (strcmp(name, funcp->name) == 0) {
2686 funcp = funcp->next;
2688 debug_printf_exec("found function '%s'\n", name);
2692 /* Note: takes ownership on name ptr */
2693 static struct function *new_function(char *name)
2695 struct function *funcp;
2696 struct function **funcpp = &G.top_func;
2698 while ((funcp = *funcpp) != NULL) {
2699 struct command *cmd;
2701 if (strcmp(funcp->name, name) != 0) {
2702 funcpp = &funcp->next;
2706 cmd = funcp->parent_cmd;
2707 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2709 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2711 /* Note: if !funcp->body, do not free body_as_string!
2712 * This is a special case of "-F name body" function:
2713 * body_as_string was not malloced! */
2715 free_pipe_list(funcp->body);
2717 free(funcp->body_as_string);
2721 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2722 cmd->argv[0] = funcp->name;
2723 cmd->group = funcp->body;
2725 cmd->group_as_string = funcp->body_as_string;
2730 debug_printf_exec("remembering new function '%s'\n", command->argv[0]);
2731 funcp = *funcpp = xzalloc(sizeof(*funcp));
2732 /*funcp->next = NULL;*/
2739 #define exec_function(nommu_save, funcp, argv) \
2740 exec_function(funcp, argv)
2742 static void exec_function(nommu_save_t *nommu_save,
2743 const struct function *funcp,
2744 char **argv) NORETURN;
2745 static void exec_function(nommu_save_t *nommu_save,
2746 const struct function *funcp,
2752 argv[0] = G.global_argv[0];
2753 G.global_argv = argv;
2757 /* On MMU, funcp->body is always non-NULL */
2758 n = run_list(funcp->body);
2762 re_execute_shell(&nommu_save->argv_from_re_execing,
2763 funcp->body_as_string,
2769 static int run_function(const struct function *funcp, char **argv)
2774 smallint sv_g_malloced;
2779 sv_g_malloced = G.global_args_malloced;
2780 sv_g_argc = G.global_argc;
2781 sv_g_argv = G.global_argv;
2788 argv[0] = G.global_argv[0]; /* retain $0 */
2789 G.global_args_malloced = 0;
2791 G.global_argv = argv;
2793 /* On MMU, funcp->body is always non-NULL */
2796 /* Function defined by -F */
2797 parse_and_run_string(funcp->body_as_string);
2798 n = G.last_exitcode;
2802 n = run_list(funcp->body);
2805 if (G.global_args_malloced) {
2806 /* function ran "set -- arg1 arg2 ..." */
2810 free(G.global_argv);
2814 G.global_args_malloced = sv_g_malloced;
2815 G.global_argc = sv_g_argc;
2816 G.global_argv = sv_g_argv;
2824 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2825 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2826 #define pseudo_exec(nommu_save, command, argv_expanded) \
2827 pseudo_exec(command, argv_expanded)
2830 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2832 * XXX no exit() here. If you don't exec, use _exit instead.
2833 * The at_exit handlers apparently confuse the calling process,
2834 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2835 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2836 char **argv, int assignment_cnt,
2837 char **argv_expanded) NORETURN;
2838 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2839 char **argv, int assignment_cnt,
2840 char **argv_expanded)
2844 /* Case when we are here: ... | var=val | ... */
2845 if (!argv[assignment_cnt])
2846 _exit(EXIT_SUCCESS);
2848 new_env = expand_assignments(argv, assignment_cnt);
2850 putenv_all(new_env);
2851 free(new_env); /* optional */
2853 nommu_save->new_env = new_env;
2854 nommu_save->old_env = putenv_all_and_save_old(new_env);
2856 if (argv_expanded) {
2857 argv = argv_expanded;
2859 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2861 nommu_save->argv = argv;
2865 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2866 if (strchr(argv[0], '/') != NULL)
2870 /* On NOMMU, we must never block!
2871 * Example: { sleep 99999 | read line } & echo Ok
2872 * read builtin will block on read syscall, leaving parent blocked
2873 * in vfork. Therefore we can't do this:
2876 /* Check if the command matches any of the builtins.
2877 * Depending on context, this might be redundant. But it's
2878 * easier to waste a few CPU cycles than it is to figure out
2879 * if this is one of those cases.
2883 const struct built_in_command *x = find_builtin(argv[0]);
2885 rcode = x->function(argv);
2891 #if ENABLE_HUSH_FUNCTIONS
2892 /* Check if the command matches any functions */
2894 const struct function *funcp = find_function(argv[0]);
2896 exec_function(nommu_save, funcp, argv);
2901 #if ENABLE_FEATURE_SH_STANDALONE
2902 /* Check if the command matches any busybox applets */
2904 int a = find_applet_by_name(argv[0]);
2906 # if BB_MMU /* see above why on NOMMU it is not allowed */
2907 if (APPLET_IS_NOEXEC(a)) {
2908 debug_printf_exec("running applet '%s'\n", argv[0]);
2909 run_applet_no_and_exit(a, argv);
2912 /* Re-exec ourselves */
2913 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2914 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2915 execv(bb_busybox_exec_path, argv);
2916 /* If they called chroot or otherwise made the binary no longer
2917 * executable, fall through */
2922 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2925 debug_printf_exec("execing '%s'\n", argv[0]);
2926 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2927 execvp(argv[0], argv);
2928 bb_perror_msg("can't exec '%s'", argv[0]);
2929 _exit(EXIT_FAILURE);
2932 /* Called after [v]fork() in run_pipe
2934 static void pseudo_exec(nommu_save_t *nommu_save,
2935 struct command *command,
2936 char **argv_expanded) NORETURN;
2937 static void pseudo_exec(nommu_save_t *nommu_save,
2938 struct command *command,
2939 char **argv_expanded)
2941 if (command->argv) {
2942 pseudo_exec_argv(nommu_save, command->argv,
2943 command->assignment_cnt, argv_expanded);
2946 if (command->group) {
2947 /* Cases when we are here:
2950 * ... | ( list ) | ...
2951 * ... | { list } | ...
2955 debug_printf_exec("pseudo_exec: run_list\n");
2956 reset_traps_to_defaults();
2957 rcode = run_list(command->group);
2958 /* OK to leak memory by not calling free_pipe_list,
2959 * since this process is about to exit */
2962 re_execute_shell(&nommu_save->argv_from_re_execing,
2963 command->group_as_string,
2969 /* Case when we are here: ... | >file */
2970 debug_printf_exec("pseudo_exec'ed null command\n");
2971 _exit(EXIT_SUCCESS);
2975 static const char *get_cmdtext(struct pipe *pi)
2981 /* This is subtle. ->cmdtext is created only on first backgrounding.
2982 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2983 * On subsequent bg argv is trashed, but we won't use it */
2986 argv = pi->cmds[0].argv;
2987 if (!argv || !argv[0]) {
2988 pi->cmdtext = xzalloc(1);
2993 do len += strlen(*argv) + 1; while (*++argv);
2994 pi->cmdtext = p = xmalloc(len);
2995 argv = pi->cmds[0].argv;
2997 len = strlen(*argv);
2998 memcpy(p, *argv, len);
3006 static void insert_bg_job(struct pipe *pi)
3008 struct pipe *thejob;
3011 /* Linear search for the ID of the job to use */
3013 for (thejob = G.job_list; thejob; thejob = thejob->next)
3014 if (thejob->jobid >= pi->jobid)
3015 pi->jobid = thejob->jobid + 1;
3017 /* Add thejob to the list of running jobs */
3019 thejob = G.job_list = xmalloc(sizeof(*thejob));
3021 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
3023 thejob->next = xmalloc(sizeof(*thejob));
3024 thejob = thejob->next;
3027 /* Physically copy the struct job */
3028 memcpy(thejob, pi, sizeof(struct pipe));
3029 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3030 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
3031 for (i = 0; i < pi->num_cmds; i++) {
3032 // TODO: do we really need to have so many fields which are just dead weight
3033 // at execution stage?
3034 thejob->cmds[i].pid = pi->cmds[i].pid;
3035 /* all other fields are not used and stay zero */
3037 thejob->next = NULL;
3038 thejob->cmdtext = xstrdup(get_cmdtext(pi));
3040 /* We don't wait for background thejobs to return -- append it
3041 to the list of backgrounded thejobs and leave it alone */
3042 if (G_interactive_fd)
3043 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
3044 G.last_bg_pid = thejob->cmds[0].pid;
3045 G.last_jobid = thejob->jobid;
3048 static void remove_bg_job(struct pipe *pi)
3050 struct pipe *prev_pipe;
3052 if (pi == G.job_list) {
3053 G.job_list = pi->next;
3055 prev_pipe = G.job_list;
3056 while (prev_pipe->next != pi)
3057 prev_pipe = prev_pipe->next;
3058 prev_pipe->next = pi->next;
3061 G.last_jobid = G.job_list->jobid;
3066 /* Remove a backgrounded job */
3067 static void delete_finished_bg_job(struct pipe *pi)
3070 pi->stopped_cmds = 0;
3076 /* Check to see if any processes have exited -- if they
3077 * have, figure out why and see if a job has completed */
3078 static int checkjobs(struct pipe* fg_pipe)
3088 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3091 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3092 // /* avoid doing syscall, nothing there anyway */
3095 attributes = WUNTRACED;
3096 if (fg_pipe == NULL)
3097 attributes |= WNOHANG;
3099 /* Do we do this right?
3100 * bash-3.00# sleep 20 | false
3102 * [3]+ Stopped sleep 20 | false
3103 * bash-3.00# echo $?
3104 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3107 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
3108 //are stopped. Testcase: "cat | cat" in a script (not on command line)
3109 // + killall -STOP cat
3116 // i = G.count_SIGCHLD;
3117 childpid = waitpid(-1, &status, attributes);
3118 if (childpid <= 0) {
3119 if (childpid && errno != ECHILD)
3120 bb_perror_msg("waitpid");
3121 // else /* Until next SIGCHLD, waitpid's are useless */
3122 // G.handled_SIGCHLD = i;
3125 dead = WIFEXITED(status) || WIFSIGNALED(status);
3128 if (WIFSTOPPED(status))
3129 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3130 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3131 if (WIFSIGNALED(status))
3132 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3133 childpid, WTERMSIG(status), WEXITSTATUS(status));
3134 if (WIFEXITED(status))
3135 debug_printf_jobs("pid %d exited, exitcode %d\n",
3136 childpid, WEXITSTATUS(status));
3138 /* Were we asked to wait for fg pipe? */
3140 for (i = 0; i < fg_pipe->num_cmds; i++) {
3141 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3142 if (fg_pipe->cmds[i].pid != childpid)
3144 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
3146 fg_pipe->cmds[i].pid = 0;
3147 fg_pipe->alive_cmds--;
3148 if (i == fg_pipe->num_cmds - 1) {
3149 /* last process gives overall exitstatus */
3150 rcode = WEXITSTATUS(status);
3151 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3154 fg_pipe->cmds[i].is_stopped = 1;
3155 fg_pipe->stopped_cmds++;
3157 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3158 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3159 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3160 /* All processes in fg pipe have exited/stopped */
3162 if (fg_pipe->alive_cmds)
3163 insert_bg_job(fg_pipe);
3167 /* There are still running processes in the fg pipe */
3168 goto wait_more; /* do waitpid again */
3170 /* it wasnt fg_pipe, look for process in bg pipes */
3174 /* We asked to wait for bg or orphaned children */
3175 /* No need to remember exitcode in this case */
3176 for (pi = G.job_list; pi; pi = pi->next) {
3177 for (i = 0; i < pi->num_cmds; i++) {
3178 if (pi->cmds[i].pid == childpid)
3179 goto found_pi_and_prognum;
3182 /* Happens when shell is used as init process (init=/bin/sh) */
3183 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3184 continue; /* do waitpid again */
3186 found_pi_and_prognum:
3189 pi->cmds[i].pid = 0;
3191 if (!pi->alive_cmds) {
3192 if (G_interactive_fd)
3193 printf(JOB_STATUS_FORMAT, pi->jobid,
3194 "Done", pi->cmdtext);
3195 delete_finished_bg_job(pi);
3199 pi->cmds[i].is_stopped = 1;
3203 } /* while (waitpid succeeds)... */
3209 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3212 int rcode = checkjobs(fg_pipe);
3213 /* Job finished, move the shell to the foreground */
3214 p = getpgid(0); /* pgid of our process */
3215 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3216 tcsetpgrp(G_interactive_fd, p);
3221 /* Start all the jobs, but don't wait for anything to finish.
3224 * Return code is normally -1, when the caller has to wait for children
3225 * to finish to determine the exit status of the pipe. If the pipe
3226 * is a simple builtin command, however, the action is done by the
3227 * time run_pipe returns, and the exit code is provided as the
3230 * Returns -1 only if started some children. IOW: we have to
3231 * mask out retvals of builtins etc with 0xff!
3233 * The only case when we do not need to [v]fork is when the pipe
3234 * is single, non-backgrounded, non-subshell command. Examples:
3235 * cmd ; ... { list } ; ...
3236 * cmd && ... { list } && ...
3237 * cmd || ... { list } || ...
3238 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3239 * or (if SH_STANDALONE) an applet, and we can run the { list }
3240 * with run_list(). If it isn't one of these, we fork and exec cmd.
3242 * Cases when we must fork:
3243 * non-single: cmd | cmd
3244 * backgrounded: cmd & { list } &
3245 * subshell: ( list ) [&]
3247 static int run_pipe(struct pipe *pi)
3249 static const char *const null_ptr = NULL;
3252 int pipefds[2]; /* pipefds[0] is for reading */
3253 struct command *command;
3254 char **argv_expanded;
3257 /* it is not always needed, but we aim to smaller code */
3258 int squirrel[] = { -1, -1, -1 };
3261 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3264 USE_HUSH_JOB(pi->pgrp = -1;)
3265 pi->stopped_cmds = 0;
3266 command = &(pi->cmds[0]);
3267 argv_expanded = NULL;
3269 if (pi->num_cmds != 1
3270 || pi->followup == PIPE_BG
3271 || command->grp_type == GRP_SUBSHELL
3278 debug_printf_exec(": group:%p argv:'%s'\n",
3279 command->group, command->argv ? command->argv[0] : "NONE");
3281 if (command->group) {
3282 #if ENABLE_HUSH_FUNCTIONS
3283 if (command->grp_type == GRP_FUNCTION) {
3284 /* "executing" func () { list } */
3285 struct function *funcp;
3287 funcp = new_function(command->argv[0]);
3288 /* funcp->name is already set to argv[0] */
3289 funcp->body = command->group;
3291 funcp->body_as_string = command->group_as_string;
3292 command->group_as_string = NULL;
3294 command->group = NULL;
3295 command->argv[0] = NULL;
3296 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3297 funcp->parent_cmd = command;
3298 command->child_func = funcp;
3300 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3302 return EXIT_SUCCESS;
3306 debug_printf("non-subshell group\n");
3307 rcode = 1; /* exitcode if redir failed */
3308 if (setup_redirects(command, squirrel) == 0) {
3309 debug_printf_exec(": run_list\n");
3310 rcode = run_list(command->group) & 0xff;
3312 restore_redirects(squirrel);
3313 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3315 debug_printf_exec("run_pipe: return %d\n", rcode);
3319 argv = command->argv ? command->argv : (char **) &null_ptr;
3321 const struct built_in_command *x;
3322 #if ENABLE_HUSH_FUNCTIONS
3323 const struct function *funcp;
3327 char **new_env = NULL;
3328 char **old_env = NULL;
3330 if (argv[command->assignment_cnt] == NULL) {
3331 /* Assignments, but no command */
3332 /* Ensure redirects take effect. Try "a=t >file" */
3333 rcode = setup_redirects(command, squirrel);
3334 restore_redirects(squirrel);
3335 /* Set shell variables */
3337 p = expand_string_to_string(*argv);
3338 debug_printf_exec("set shell var:'%s'->'%s'\n",
3340 set_local_var(p, 0, 0);
3343 /* Do we need to flag set_local_var() errors?
3344 * "assignment to readonly var" and "putenv error"
3346 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3348 debug_printf_exec("run_pipe: return %d\n", rcode);
3352 /* Expand the rest into (possibly) many strings each */
3353 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3355 x = find_builtin(argv_expanded[0]);
3356 #if ENABLE_HUSH_FUNCTIONS
3359 funcp = find_function(argv_expanded[0]);
3363 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3364 debug_printf("exec with redirects only\n");
3365 rcode = setup_redirects(command, NULL);
3366 goto clean_up_and_ret1;
3369 /* XXX setup_redirects acts on file descriptors, not FILEs.
3370 * This is perfect for work that comes after exec().
3371 * Is it really safe for inline use? Experimentally,
3372 * things seem to work with glibc. */
3373 rcode = setup_redirects(command, squirrel);
3375 new_env = expand_assignments(argv, command->assignment_cnt);
3376 old_env = putenv_all_and_save_old(new_env);
3378 debug_printf_exec(": builtin '%s' '%s'...\n",
3379 x->cmd, argv_expanded[1]);
3380 rcode = x->function(argv_expanded) & 0xff;
3382 #if ENABLE_HUSH_FUNCTIONS
3384 debug_printf_exec(": function '%s' '%s'...\n",
3385 funcp->name, argv_expanded[1]);
3386 rcode = run_function(funcp, argv_expanded) & 0xff;
3390 #if ENABLE_FEATURE_SH_STANDALONE
3393 restore_redirects(squirrel);
3394 free_strings_and_unsetenv(new_env, 1);
3395 putenv_all(old_env);
3396 /* Free the pointers, but the strings themselves
3397 * are in environ now, don't use free_strings! */
3400 free(argv_expanded);
3401 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3403 debug_printf_exec("run_pipe return %d\n", rcode);
3407 #if ENABLE_FEATURE_SH_STANDALONE
3408 i = find_applet_by_name(argv_expanded[0]);
3409 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3410 rcode = setup_redirects(command, squirrel);
3412 save_nofork_data(&G.nofork_save);
3413 new_env = expand_assignments(argv, command->assignment_cnt);
3414 old_env = putenv_all_and_save_old(new_env);
3415 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3416 argv_expanded[0], argv_expanded[1]);
3417 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3419 goto clean_up_and_ret;
3422 /* It is neither builtin nor applet. We must fork. */
3426 /* NB: argv_expanded may already be created, and that
3427 * might include `cmd` runs! Do not rerun it! We *must*
3428 * use argv_expanded if it's non-NULL */
3430 /* Going to fork a child per each pipe member */
3434 for (i = 0; i < pi->num_cmds; i++) {
3436 volatile nommu_save_t nommu_save;
3437 nommu_save.new_env = NULL;
3438 nommu_save.old_env = NULL;
3439 nommu_save.argv = NULL;
3440 nommu_save.argv_from_re_execing = NULL;
3442 command = &(pi->cmds[i]);
3443 if (command->argv) {
3444 debug_printf_exec(": pipe member '%s' '%s'...\n",
3445 command->argv[0], command->argv[1]);
3447 debug_printf_exec(": pipe member with no argv\n");
3450 /* pipes are inserted between pairs of commands */
3453 if ((i + 1) < pi->num_cmds)
3456 command->pid = BB_MMU ? fork() : vfork();
3457 if (!command->pid) { /* child */
3459 disable_restore_tty_pgrp_on_exit();
3461 /* Every child adds itself to new process group
3462 * with pgid == pid_of_first_child_in_pipe */
3463 if (G.run_list_level == 1 && G_interactive_fd) {
3466 if (pgrp < 0) /* true for 1st process only */
3468 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3469 /* We do it in *every* child, not just first,
3471 tcsetpgrp(G_interactive_fd, pgrp);
3475 xmove_fd(nextin, 0);
3476 xmove_fd(pipefds[1], 1); /* write end */
3478 close(pipefds[0]); /* read end */
3479 /* Like bash, explicit redirects override pipes,
3480 * and the pipe fd is available for dup'ing. */
3481 if (setup_redirects(command, NULL))
3484 /* Restore default handlers just prior to exec */
3485 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3487 /* Stores to nommu_save list of env vars putenv'ed
3488 * (NOMMU, on MMU we don't need that) */
3489 /* cast away volatility... */
3490 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3491 /* pseudo_exec() does not return */
3494 /* parent or error */
3495 enable_restore_tty_pgrp_on_exit();
3497 /* Clean up after vforked child */
3498 free(nommu_save.argv);
3499 free(nommu_save.argv_from_re_execing);
3500 free_strings_and_unsetenv(nommu_save.new_env, 1);
3501 putenv_all(nommu_save.old_env);
3502 /* Free the pointers, but the strings themselves
3503 * are in environ now, don't use free_strings! */
3504 free(nommu_save.old_env);
3506 free(argv_expanded);
3507 argv_expanded = NULL;
3508 if (command->pid < 0) { /* [v]fork failed */
3509 /* Clearly indicate, was it fork or vfork */
3510 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3514 /* Second and next children need to know pid of first one */
3516 pi->pgrp = command->pid;
3522 if ((i + 1) < pi->num_cmds)
3523 close(pipefds[1]); /* write end */
3524 /* Pass read (output) pipe end to next iteration */
3525 nextin = pipefds[0];
3528 if (!pi->alive_cmds) {
3530 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3535 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3539 #ifndef debug_print_tree
3540 static void debug_print_tree(struct pipe *pi, int lvl)
3542 static const char *const PIPE[] = {
3548 static const char *RES[] = {
3549 [RES_NONE ] = "NONE" ,
3552 [RES_THEN ] = "THEN" ,
3553 [RES_ELIF ] = "ELIF" ,
3554 [RES_ELSE ] = "ELSE" ,
3557 #if ENABLE_HUSH_LOOPS
3558 [RES_FOR ] = "FOR" ,
3559 [RES_WHILE] = "WHILE",
3560 [RES_UNTIL] = "UNTIL",
3562 [RES_DONE ] = "DONE" ,
3564 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3567 #if ENABLE_HUSH_CASE
3568 [RES_CASE ] = "CASE" ,
3569 [RES_MATCH] = "MATCH",
3570 [RES_CASEI] = "CASEI",
3571 [RES_ESAC ] = "ESAC" ,
3573 [RES_XXXX ] = "XXXX" ,
3574 [RES_SNTX ] = "SNTX" ,
3576 static const char *const GRPTYPE[] = {
3579 #if ENABLE_HUSH_FUNCTIONS
3588 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3589 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3591 while (prn < pi->num_cmds) {
3592 struct command *command = &pi->cmds[prn];
3593 char **argv = command->argv;
3595 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3597 command->assignment_cnt);
3598 if (command->group) {
3599 fprintf(stderr, " group %s: (argv=%p)\n",
3600 GRPTYPE[command->grp_type],
3602 debug_print_tree(command->group, lvl+1);
3606 if (argv) while (*argv) {
3607 fprintf(stderr, " '%s'", *argv);
3610 fprintf(stderr, "\n");
3619 /* NB: called by pseudo_exec, and therefore must not modify any
3620 * global data until exec/_exit (we can be a child after vfork!) */
3621 static int run_list(struct pipe *pi)
3623 #if ENABLE_HUSH_CASE
3624 char *case_word = NULL;
3626 #if ENABLE_HUSH_LOOPS
3627 struct pipe *loop_top = NULL;
3628 char *for_varname = NULL;
3629 char **for_lcur = NULL;
3630 char **for_list = NULL;
3632 smallint last_followup;
3634 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3635 smalluint cond_code = 0;
3637 enum { cond_code = 0 };
3640 smallint rword; /* enum reserved_style */
3641 smallint last_rword; /* ditto */
3644 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3647 #if ENABLE_HUSH_LOOPS
3648 /* Check syntax for "for" */
3649 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3650 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3652 /* current word is FOR or IN (BOLD in comments below) */
3653 if (cpipe->next == NULL) {
3654 syntax_error("malformed for");
3656 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3659 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3660 if (cpipe->next->res_word == RES_DO)
3662 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3663 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3664 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3666 syntax_error("malformed for");
3668 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3674 /* Past this point, all code paths should jump to ret: label
3675 * in order to return, no direct "return" statements please.
3676 * This helps to ensure that no memory is leaked. */
3678 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3681 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3682 * We are saving state before entering outermost list ("while...done")
3683 * so that ctrl-Z will correctly background _entire_ outermost list,
3684 * not just a part of it (like "sleep 1 | exit 2") */
3685 if (++G.run_list_level == 1 && G_interactive_fd) {
3686 if (sigsetjmp(G.toplevel_jb, 1)) {
3687 /* ctrl-Z forked and we are parent; or ctrl-C.
3688 * Sighandler has longjmped us here */
3689 signal(SIGINT, SIG_IGN);
3690 signal(SIGTSTP, SIG_IGN);
3691 /* Restore level (we can be coming from deep inside
3693 G.run_list_level = 1;
3694 #if ENABLE_FEATURE_SH_STANDALONE
3695 if (G.nofork_save.saved) { /* if save area is valid */
3696 debug_printf_jobs("exiting nofork early\n");
3697 restore_nofork_data(&G.nofork_save);
3700 //// if (G.ctrl_z_flag) {
3701 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3702 //// * Remember this child as background job */
3703 //// insert_bg_job(pi);
3705 /* ctrl-C. We just stop doing whatever we were doing */
3708 USE_HUSH_LOOPS(loop_top = NULL;)
3709 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3713 //// /* ctrl-Z handler will store pid etc in pi */
3714 //// G.toplevel_list = pi;
3715 //// G.ctrl_z_flag = 0;
3716 #if ENABLE_FEATURE_SH_STANDALONE
3717 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3719 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3720 //// signal(SIGINT, handler_ctrl_c);
3726 last_rword = RES_XXXX;
3728 last_followup = PIPE_SEQ;
3729 rcode = G.last_exitcode;
3731 /* Go through list of pipes, (maybe) executing them. */
3732 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3736 IF_HAS_KEYWORDS(rword = pi->res_word;)
3737 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3738 rword, cond_code, last_rword);
3739 #if ENABLE_HUSH_LOOPS
3740 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3741 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3743 /* start of a loop: remember where loop starts */
3748 /* Still in the same "if...", "then..." or "do..." branch? */
3749 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3750 if ((rcode == 0 && last_followup == PIPE_OR)
3751 || (rcode != 0 && last_followup == PIPE_AND)
3753 /* It is "<true> || CMD" or "<false> && CMD"
3754 * and we should not execute CMD */
3755 debug_printf_exec("skipped cmd because of || or &&\n");
3756 last_followup = pi->followup;
3760 last_followup = pi->followup;
3761 IF_HAS_KEYWORDS(last_rword = rword;)
3764 if (rword == RES_THEN) {
3765 /* if false; then ... fi has exitcode 0! */
3766 G.last_exitcode = rcode = EXIT_SUCCESS;
3767 /* "if <false> THEN cmd": skip cmd */
3771 if (rword == RES_ELSE || rword == RES_ELIF) {
3772 /* "if <true> then ... ELSE/ELIF cmd":
3773 * skip cmd and all following ones */
3778 #if ENABLE_HUSH_LOOPS
3779 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3781 /* first loop through for */
3783 static const char encoded_dollar_at[] ALIGN1 = {
3784 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3785 }; /* encoded representation of "$@" */
3786 static const char *const encoded_dollar_at_argv[] = {
3787 encoded_dollar_at, NULL
3788 }; /* argv list with one element: "$@" */
3791 vals = (char**)encoded_dollar_at_argv;
3792 if (pi->next->res_word == RES_IN) {
3793 /* if no variable values after "in" we skip "for" */
3794 if (!pi->next->cmds[0].argv) {
3795 G.last_exitcode = rcode = EXIT_SUCCESS;
3796 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3799 vals = pi->next->cmds[0].argv;
3800 } /* else: "for var; do..." -> assume "$@" list */
3801 /* create list of variable values */
3802 debug_print_strings("for_list made from", vals);
3803 for_list = expand_strvec_to_strvec(vals);
3804 for_lcur = for_list;
3805 debug_print_strings("for_list", for_list);
3806 for_varname = pi->cmds[0].argv[0];
3807 pi->cmds[0].argv[0] = NULL;
3809 free(pi->cmds[0].argv[0]);
3811 /* "for" loop is over, clean up */
3815 pi->cmds[0].argv[0] = for_varname;
3818 /* Insert next value from for_lcur */
3819 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3820 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3821 pi->cmds[0].assignment_cnt = 1;
3823 if (rword == RES_IN) {
3824 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3826 if (rword == RES_DONE) {
3827 continue; /* "done" has no cmds too */
3830 #if ENABLE_HUSH_CASE
3831 if (rword == RES_CASE) {
3832 case_word = expand_strvec_to_string(pi->cmds->argv);
3835 if (rword == RES_MATCH) {
3838 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3840 /* all prev words didn't match, does this one match? */
3841 argv = pi->cmds->argv;
3843 char *pattern = expand_string_to_string(*argv);
3844 /* TODO: which FNM_xxx flags to use? */
3845 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3847 if (cond_code == 0) { /* match! we will execute this branch */
3848 free(case_word); /* make future "word)" stop */
3856 if (rword == RES_CASEI) { /* inside of a case branch */
3858 continue; /* not matched yet, skip this pipe */
3861 /* Just pressing <enter> in shell should check for jobs.
3862 * OTOH, in non-interactive shell this is useless
3863 * and only leads to extra job checks */
3864 if (pi->num_cmds == 0) {
3865 if (G_interactive_fd)
3866 goto check_jobs_and_continue;
3870 /* After analyzing all keywords and conditions, we decided
3871 * to execute this pipe. NB: have to do checkjobs(NULL)
3872 * after run_pipe to collect any background children,
3873 * even if list execution is to be stopped. */
3874 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3877 #if ENABLE_HUSH_LOOPS
3878 G.flag_break_continue = 0;
3880 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3882 /* We only ran a builtin: rcode is already known
3883 * and we don't need to wait for anything. */
3884 G.last_exitcode = rcode;
3885 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3886 check_and_run_traps(0);
3887 #if ENABLE_HUSH_LOOPS
3888 /* Was it "break" or "continue"? */
3889 if (G.flag_break_continue) {
3890 smallint fbc = G.flag_break_continue;
3891 /* We might fall into outer *loop*,
3892 * don't want to break it too */
3894 G.depth_break_continue--;
3895 if (G.depth_break_continue == 0)
3896 G.flag_break_continue = 0;
3897 /* else: e.g. "continue 2" should *break* once, *then* continue */
3898 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3899 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3900 goto check_jobs_and_break;
3901 /* "continue": simulate end of loop */
3906 } else if (pi->followup == PIPE_BG) {
3907 /* What does bash do with attempts to background builtins? */
3908 /* even bash 3.2 doesn't do that well with nested bg:
3909 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3910 * I'm NOT treating inner &'s as jobs */
3911 check_and_run_traps(0);
3913 if (G.run_list_level == 1)
3916 G.last_exitcode = rcode = EXIT_SUCCESS;
3917 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3920 if (G.run_list_level == 1 && G_interactive_fd) {
3921 /* Waits for completion, then fg's main shell */
3922 rcode = checkjobs_and_fg_shell(pi);
3923 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3924 check_and_run_traps(0);
3927 { /* This one just waits for completion */
3928 rcode = checkjobs(pi);
3929 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3930 check_and_run_traps(0);
3932 G.last_exitcode = rcode;
3936 /* Analyze how result affects subsequent commands */
3938 if (rword == RES_IF || rword == RES_ELIF)
3941 #if ENABLE_HUSH_LOOPS
3942 /* Beware of "while false; true; do ..."! */
3943 if (pi->next && pi->next->res_word == RES_DO) {
3944 if (rword == RES_WHILE) {
3946 /* "while false; do...done" - exitcode 0 */
3947 G.last_exitcode = rcode = EXIT_SUCCESS;
3948 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3949 goto check_jobs_and_break;
3952 if (rword == RES_UNTIL) {
3954 debug_printf_exec(": until expr is true: breaking\n");
3955 check_jobs_and_break:
3963 check_jobs_and_continue:
3968 //// if (G.ctrl_z_flag) {
3969 //// /* ctrl-Z forked somewhere in the past, we are the child,
3970 //// * and now we completed running the list. Exit. */
3976 //// if (!G.run_list_level && G_interactive_fd) {
3977 //// signal(SIGTSTP, SIG_IGN);
3978 //// signal(SIGINT, SIG_IGN);
3981 #if ENABLE_HUSH_LOOPS
3986 #if ENABLE_HUSH_CASE
3990 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3994 /* Select which version we will use */
3995 static int run_and_free_list(struct pipe *pi)
3998 debug_printf_exec("run_and_free_list entered\n");
4000 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4001 rcode = run_list(pi);
4003 /* free_pipe_list has the side effect of clearing memory.
4004 * In the long run that function can be merged with run_list,
4005 * but doing that now would hobble the debugging effort. */
4007 debug_printf_exec("run_and_free_list return %d\n", rcode);
4012 static struct pipe *new_pipe(void)
4015 pi = xzalloc(sizeof(struct pipe));
4016 /*pi->followup = 0; - deliberately invalid value */
4017 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4021 /* Command (member of a pipe) is complete. The only possible error here
4022 * is out of memory, in which case xmalloc exits. */
4023 static int done_command(struct parse_context *ctx)
4025 /* The command is really already in the pipe structure, so
4026 * advance the pipe counter and make a new, null command. */
4027 struct pipe *pi = ctx->pipe;
4028 struct command *command = ctx->command;
4031 if (command->group == NULL
4032 && command->argv == NULL
4033 && command->redirects == NULL
4035 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4036 memset(command, 0, sizeof(*command)); /* paranoia */
4037 return pi->num_cmds;
4040 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4041 //debug_print_tree(ctx->list_head, 20);
4043 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4046 /* Only real trickiness here is that the uncommitted
4047 * command structure is not counted in pi->num_cmds. */
4048 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4049 command = &pi->cmds[pi->num_cmds];
4050 memset(command, 0, sizeof(*command));
4052 ctx->command = command;
4053 /* but ctx->pipe and ctx->list_head remain unchanged */
4055 return pi->num_cmds; /* used only for 0/nonzero check */
4058 static void done_pipe(struct parse_context *ctx, pipe_style type)
4062 debug_printf_parse("done_pipe entered, followup %d\n", type);
4063 /* Close previous command */
4064 not_null = done_command(ctx);
4065 ctx->pipe->followup = type;
4067 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4068 ctx->ctx_inverted = 0;
4069 ctx->pipe->res_word = ctx->ctx_res_w;
4072 /* Without this check, even just <enter> on command line generates
4073 * tree of three NOPs (!). Which is harmless but annoying.
4074 * IOW: it is safe to do it unconditionally.
4075 * RES_NONE case is for "for a in; do ..." (empty IN set)
4076 * and other cases to work. */
4079 || ctx->ctx_res_w == RES_FI
4081 #if ENABLE_HUSH_LOOPS
4082 || ctx->ctx_res_w == RES_DONE
4083 || ctx->ctx_res_w == RES_FOR
4084 || ctx->ctx_res_w == RES_IN
4086 #if ENABLE_HUSH_CASE
4087 || ctx->ctx_res_w == RES_ESAC
4091 debug_printf_parse("done_pipe: adding new pipe: "
4092 "not_null:%d ctx->ctx_res_w:%d\n",
4093 not_null, ctx->ctx_res_w);
4095 ctx->pipe->next = new_p;
4097 /* RES_THEN, RES_DO etc are "sticky" -
4098 * they remain set for commands inside if/while.
4099 * This is used to control execution.
4100 * RES_FOR and RES_IN are NOT sticky (needed to support
4101 * cases where variable or value happens to match a keyword):
4103 #if ENABLE_HUSH_LOOPS
4104 if (ctx->ctx_res_w == RES_FOR
4105 || ctx->ctx_res_w == RES_IN)
4106 ctx->ctx_res_w = RES_NONE;
4108 #if ENABLE_HUSH_CASE
4109 if (ctx->ctx_res_w == RES_MATCH)
4110 ctx->ctx_res_w = RES_CASEI;
4112 ctx->command = NULL; /* trick done_command below */
4113 /* Create the memory for command, roughly:
4114 * ctx->pipe->cmds = new struct command;
4115 * ctx->command = &ctx->pipe->cmds[0];
4118 //debug_print_tree(ctx->list_head, 10);
4120 debug_printf_parse("done_pipe return\n");
4123 static void initialize_context(struct parse_context *ctx)
4125 memset(ctx, 0, sizeof(*ctx));
4126 ctx->pipe = ctx->list_head = new_pipe();
4127 /* Create the memory for command, roughly:
4128 * ctx->pipe->cmds = new struct command;
4129 * ctx->command = &ctx->pipe->cmds[0];
4134 /* If a reserved word is found and processed, parse context is modified
4135 * and 1 is returned.
4138 struct reserved_combo {
4141 unsigned char assignment_flag;
4145 FLAG_END = (1 << RES_NONE ),
4147 FLAG_IF = (1 << RES_IF ),
4148 FLAG_THEN = (1 << RES_THEN ),
4149 FLAG_ELIF = (1 << RES_ELIF ),
4150 FLAG_ELSE = (1 << RES_ELSE ),
4151 FLAG_FI = (1 << RES_FI ),
4153 #if ENABLE_HUSH_LOOPS
4154 FLAG_FOR = (1 << RES_FOR ),
4155 FLAG_WHILE = (1 << RES_WHILE),
4156 FLAG_UNTIL = (1 << RES_UNTIL),
4157 FLAG_DO = (1 << RES_DO ),
4158 FLAG_DONE = (1 << RES_DONE ),
4159 FLAG_IN = (1 << RES_IN ),
4161 #if ENABLE_HUSH_CASE
4162 FLAG_MATCH = (1 << RES_MATCH),
4163 FLAG_ESAC = (1 << RES_ESAC ),
4165 FLAG_START = (1 << RES_XXXX ),
4168 static const struct reserved_combo* match_reserved_word(o_string *word)
4170 /* Mostly a list of accepted follow-up reserved words.
4171 * FLAG_END means we are done with the sequence, and are ready
4172 * to turn the compound list into a command.
4173 * FLAG_START means the word must start a new compound list.
4175 static const struct reserved_combo reserved_list[] = {
4177 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4178 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4179 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4180 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4181 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4182 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4184 #if ENABLE_HUSH_LOOPS
4185 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4186 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4187 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4188 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4189 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4190 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4192 #if ENABLE_HUSH_CASE
4193 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4194 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4197 const struct reserved_combo *r;
4199 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4200 if (strcmp(word->data, r->literal) == 0)
4205 static int reserved_word(o_string *word, struct parse_context *ctx)
4207 #if ENABLE_HUSH_CASE
4208 static const struct reserved_combo reserved_match = {
4209 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4212 const struct reserved_combo *r;
4214 r = match_reserved_word(word);
4218 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4219 #if ENABLE_HUSH_CASE
4220 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4221 /* "case word IN ..." - IN part starts first match part */
4222 r = &reserved_match;
4225 if (r->flag == 0) { /* '!' */
4226 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4227 syntax_error("! ! command");
4228 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
4230 ctx->ctx_inverted = 1;
4233 if (r->flag & FLAG_START) {
4234 struct parse_context *old;
4235 old = xmalloc(sizeof(*old));
4236 debug_printf_parse("push stack %p\n", old);
4237 *old = *ctx; /* physical copy */
4238 initialize_context(ctx);
4240 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4241 syntax_error_at(word->data);
4242 ctx->ctx_res_w = RES_SNTX;
4245 ctx->ctx_res_w = r->res;
4246 ctx->old_flag = r->flag;
4247 if (ctx->old_flag & FLAG_END) {
4248 struct parse_context *old;
4249 done_pipe(ctx, PIPE_SEQ);
4250 debug_printf_parse("pop stack %p\n", ctx->stack);
4252 old->command->group = ctx->list_head;
4253 old->command->grp_type = GRP_NORMAL;
4255 o_addstr(&old->as_string, ctx->as_string.data);
4256 o_free_unsafe(&ctx->as_string);
4257 old->command->group_as_string = xstrdup(old->as_string.data);
4258 debug_printf_parse("pop, remembering as:'%s'\n",
4259 old->command->group_as_string);
4261 *ctx = *old; /* physical copy */
4264 word->o_assignment = r->assignment_flag;
4269 /* Word is complete, look at it and update parsing context.
4270 * Normal return is 0. Syntax errors return 1.
4271 * Note: on return, word is reset, but not o_free'd!
4273 static int done_word(o_string *word, struct parse_context *ctx)
4275 struct command *command = ctx->command;
4277 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4278 if (word->length == 0 && word->o_quoted == 0) {
4279 debug_printf_parse("done_word return 0: true null, ignored\n");
4283 if (ctx->pending_redirect) {
4284 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4285 * only if run as "bash", not "sh" */
4286 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4288 * ...the word that follows the redirection operator
4289 * shall be subjected to tilde expansion, parameter expansion,
4290 * command substitution, arithmetic expansion, and quote
4291 * removal. Pathname expansion shall not be performed
4292 * on the word by a non-interactive shell; an interactive
4293 * shell may perform it, but shall do so only when
4294 * the expansion would result in one word."
4296 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4297 /* Cater for >\file case:
4298 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4299 * Same with heredocs:
4300 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4302 unbackslash(ctx->pending_redirect->rd_filename);
4303 /* Is it <<"HEREDOC"? */
4304 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4307 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4309 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4310 ctx->pending_redirect = NULL;
4312 /* If this word wasn't an assignment, next ones definitely
4313 * can't be assignments. Even if they look like ones. */
4314 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4315 && word->o_assignment != WORD_IS_KEYWORD
4317 word->o_assignment = NOT_ASSIGNMENT;
4319 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4320 command->assignment_cnt++;
4321 word->o_assignment = MAYBE_ASSIGNMENT;
4324 if (command->group) {
4325 /* "{ echo foo; } echo bar" - bad */
4326 /* NB: bash allows e.g.:
4327 * if true; then { echo foo; } fi
4328 * while if false; then false; fi do break; done
4330 * while if false; then false; fi; do; break; done
4332 syntax_error_at(word->data);
4333 debug_printf_parse("done_word return 1: syntax error, "
4334 "groups and arglists don't mix\n");
4338 # if ENABLE_HUSH_CASE
4339 if (ctx->ctx_dsemicolon
4340 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4342 /* already done when ctx_dsemicolon was set to 1: */
4343 /* ctx->ctx_res_w = RES_MATCH; */
4344 ctx->ctx_dsemicolon = 0;
4347 if (!command->argv /* if it's the first word... */
4348 # if ENABLE_HUSH_LOOPS
4349 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4350 && ctx->ctx_res_w != RES_IN
4353 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
4354 if (reserved_word(word, ctx)) {
4355 o_reset_to_empty_unquoted(word);
4356 debug_printf_parse("done_word return %d\n",
4357 (ctx->ctx_res_w == RES_SNTX));
4358 return (ctx->ctx_res_w == RES_SNTX);
4362 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4363 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4364 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4365 /* (otherwise it's known to be not empty and is already safe) */
4367 /* exclude "$@" - it can expand to no word despite "" */
4368 char *p = word->data;
4369 while (p[0] == SPECIAL_VAR_SYMBOL
4370 && (p[1] & 0x7f) == '@'
4371 && p[2] == SPECIAL_VAR_SYMBOL
4375 if (p == word->data || p[0] != '\0') {
4376 /* saw no "$@", or not only "$@" but some
4377 * real text is there too */
4378 /* insert "empty variable" reference, this makes
4379 * e.g. "", $empty"" etc to not disappear */
4380 o_addchr(word, SPECIAL_VAR_SYMBOL);
4381 o_addchr(word, SPECIAL_VAR_SYMBOL);
4384 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4385 //SEGV, but good idea.
4386 // command->argv = add_string_to_strings(command->argv, word->data);
4387 // word->data = NULL;
4388 // word->length = 0;
4389 debug_print_strings("word appended to argv", command->argv);
4392 #if ENABLE_HUSH_LOOPS
4393 if (ctx->ctx_res_w == RES_FOR) {
4395 || !is_well_formed_var_name(command->argv[0], '\0')
4397 /* bash says just "not a valid identifier" */
4398 syntax_error("not a valid identifier in for");
4401 /* Force FOR to have just one word (variable name) */
4402 /* NB: basically, this makes hush see "for v in ..."
4403 * syntax as if it is "for v; in ...". FOR and IN become
4404 * two pipe structs in parse tree. */
4405 done_pipe(ctx, PIPE_SEQ);
4408 #if ENABLE_HUSH_CASE
4409 /* Force CASE to have just one word */
4410 if (ctx->ctx_res_w == RES_CASE) {
4411 done_pipe(ctx, PIPE_SEQ);
4415 o_reset_to_empty_unquoted(word);
4417 debug_printf_parse("done_word return 0\n");
4422 /* Peek ahead in the input to find out if we have a "&n" construct,
4423 * as in "2>&1", that represents duplicating a file descriptor.
4425 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4426 * REDIRFD_SYNTAX_ERR if syntax error,
4427 * REDIRFD_TO_FILE if no & was seen,
4428 * or the number found.
4431 #define parse_redir_right_fd(as_string, input) \
4432 parse_redir_right_fd(input)
4434 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4440 return REDIRFD_TO_FILE;
4442 ch = i_getch(input); /* get the & */
4443 nommu_addchr(as_string, ch);
4446 ch = i_getch(input);
4447 nommu_addchr(as_string, ch);
4448 return REDIRFD_CLOSE;
4452 while (ch != EOF && isdigit(ch)) {
4453 d = d*10 + (ch-'0');
4455 ch = i_getch(input);
4456 nommu_addchr(as_string, ch);
4461 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4463 bb_error_msg("ambiguous redirect");
4464 return REDIRFD_SYNTAX_ERR;
4467 /* Return code is 0 normal, 1 if a syntax error is detected
4469 static int parse_redirect(struct parse_context *ctx,
4472 struct in_str *input)
4474 struct command *command = ctx->command;
4475 struct redir_struct *redir;
4476 struct redir_struct **redirp;
4479 dup_num = REDIRFD_TO_FILE;
4480 if (style != REDIRECT_HEREDOC) {
4481 /* Check for a '>&1' type redirect */
4482 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4483 if (dup_num == REDIRFD_SYNTAX_ERR)
4486 int ch = i_peek(input);
4487 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4488 if (dup_num) { /* <<-... */
4489 ch = i_getch(input);
4490 nommu_addchr(&ctx->as_string, ch);
4495 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4496 int ch = i_peek(input);
4498 /* >|FILE redirect ("clobbering" >).
4499 * Since we do not support "set -o noclobber" yet,
4500 * >| and > are the same for now. Just eat |.
4502 ch = i_getch(input);
4503 nommu_addchr(&ctx->as_string, ch);
4507 /* Create a new redir_struct and append it to the linked list */
4508 redirp = &command->redirects;
4509 while ((redir = *redirp) != NULL) {
4510 redirp = &(redir->next);
4512 *redirp = redir = xzalloc(sizeof(*redir));
4513 /* redir->next = NULL; */
4514 /* redir->rd_filename = NULL; */
4515 redir->rd_type = style;
4516 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4518 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4519 redir_table[style].descrip);
4521 redir->rd_dup = dup_num;
4522 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4523 /* Erik had a check here that the file descriptor in question
4524 * is legit; I postpone that to "run time"
4525 * A "-" representation of "close me" shows up as a -3 here */
4526 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4527 redir->rd_fd, redir->rd_dup);
4529 /* Set ctx->pending_redirect, so we know what to do at the
4530 * end of the next parsed word. */
4531 ctx->pending_redirect = redir;
4536 /* If a redirect is immediately preceded by a number, that number is
4537 * supposed to tell which file descriptor to redirect. This routine
4538 * looks for such preceding numbers. In an ideal world this routine
4539 * needs to handle all the following classes of redirects...
4540 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4541 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4542 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4543 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4545 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4547 * ... If n is quoted, the number shall not be recognized as part of
4548 * the redirection expression. For example:
4550 * writes the character 2 into file a"
4551 * We are getting it right by setting ->o_quoted on any \<char>
4553 * A -1 return means no valid number was found,
4554 * the caller should use the appropriate default for this redirection.
4556 static int redirect_opt_num(o_string *o)
4560 if (o->data == NULL)
4562 num = bb_strtou(o->data, NULL, 10);
4563 if (errno || num < 0)
4565 o_reset_to_empty_unquoted(o);
4570 #define fetch_till_str(as_string, input, word, skip_tabs) \
4571 fetch_till_str(input, word, skip_tabs)
4573 static char *fetch_till_str(o_string *as_string,
4574 struct in_str *input,
4578 o_string heredoc = NULL_O_STRING;
4584 ch = i_getch(input);
4585 nommu_addchr(as_string, ch);
4587 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4588 heredoc.data[past_EOL] = '\0';
4589 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4590 return heredoc.data;
4593 o_addchr(&heredoc, ch);
4594 past_EOL = heredoc.length;
4597 ch = i_getch(input);
4598 nommu_addchr(as_string, ch);
4599 } while (skip_tabs && ch == '\t');
4600 } while (ch == '\n');
4603 o_free_unsafe(&heredoc);
4606 o_addchr(&heredoc, ch);
4607 nommu_addchr(as_string, ch);
4611 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4612 * and load them all. There should be exactly heredoc_cnt of them.
4614 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4616 struct pipe *pi = ctx->list_head;
4618 while (pi && heredoc_cnt) {
4620 struct command *cmd = pi->cmds;
4622 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4624 cmd->argv ? cmd->argv[0] : "NONE");
4625 for (i = 0; i < pi->num_cmds; i++) {
4626 struct redir_struct *redir = cmd->redirects;
4628 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4629 i, cmd->argv ? cmd->argv[0] : "NONE");
4631 if (redir->rd_type == REDIRECT_HEREDOC) {
4634 redir->rd_type = REDIRECT_HEREDOC2;
4635 /* redir->dup is (ab)used to indicate <<- */
4636 p = fetch_till_str(&ctx->as_string, input,
4637 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4639 syntax_error("unexpected EOF in here document");
4642 free(redir->rd_filename);
4643 redir->rd_filename = p;
4646 redir = redir->next;
4653 /* Should be 0. If it isn't, it's a parse error */
4655 bb_error_msg_and_die("heredoc BUG 2");
4661 #if ENABLE_HUSH_TICK
4662 static FILE *generate_stream_from_string(const char *s)
4665 int pid, channel[2];
4671 pid = BB_MMU ? fork() : vfork();
4673 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4675 if (pid == 0) { /* child */
4676 disable_restore_tty_pgrp_on_exit();
4677 /* Process substitution is not considered to be usual
4678 * 'command execution'.
4679 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4686 close(channel[0]); /* NB: close _first_, then move fd! */
4687 xmove_fd(channel[1], 1);
4688 /* Prevent it from trying to handle ctrl-z etc */
4689 USE_HUSH_JOB(G.run_list_level = 1;)
4691 reset_traps_to_defaults();
4692 parse_and_run_string(s);
4693 _exit(G.last_exitcode);
4695 /* We re-execute after vfork on NOMMU. This makes this script safe:
4696 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4697 * huge=`cat BIG` # was blocking here forever
4700 re_execute_shell(&to_free,
4708 enable_restore_tty_pgrp_on_exit();
4713 pf = fdopen(channel[0], "r");
4717 /* Return code is exit status of the process that is run. */
4718 static int process_command_subs(o_string *dest, const char *s)
4721 struct in_str pipe_str;
4724 pf = generate_stream_from_string(s);
4727 close_on_exec_on(fileno(pf));
4729 /* Now send results of command back into original context */
4730 setup_file_in_str(&pipe_str, pf);
4732 while ((ch = i_getch(&pipe_str)) != EOF) {
4738 o_addchr(dest, '\n');
4741 o_addQchr(dest, ch);
4744 debug_printf("done reading from pipe, pclose()ing\n");
4745 /* Note: we got EOF, and we just close the read end of the pipe.
4746 * We do not wait for the `cmd` child to terminate. bash and ash do.
4748 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4749 * `false`; echo $? - bash outputs "1"
4752 debug_printf("closed FILE from child. return 0\n");
4757 static int parse_group(o_string *dest, struct parse_context *ctx,
4758 struct in_str *input, int ch)
4760 /* dest contains characters seen prior to ( or {.
4761 * Typically it's empty, but for function defs,
4762 * it contains function name (without '()'). */
4763 struct pipe *pipe_list;
4765 struct command *command = ctx->command;
4767 debug_printf_parse("parse_group entered\n");
4768 #if ENABLE_HUSH_FUNCTIONS
4769 if (ch == '(' && !dest->o_quoted) {
4771 done_word(dest, ctx);
4773 goto skip; /* (... */
4774 if (command->argv[1]) { /* word word ... (... */
4775 syntax_error_unexpected_ch('(');
4778 /* it is "word(..." or "word (..." */
4780 ch = i_getch(input);
4781 while (ch == ' ' || ch == '\t');
4783 syntax_error_unexpected_ch(ch);
4786 nommu_addchr(&ctx->as_string, ch);
4788 ch = i_getch(input);
4789 while (ch == ' ' || ch == '\t' || ch == '\n');
4791 syntax_error_unexpected_ch(ch);
4794 nommu_addchr(&ctx->as_string, ch);
4795 command->grp_type = GRP_FUNCTION;
4799 if (command->argv /* word [word]{... */
4800 || dest->length /* word{... */
4801 || dest->o_quoted /* ""{... */
4804 debug_printf_parse("parse_group return 1: "
4805 "syntax error, groups and arglists don't mix\n");
4809 #if ENABLE_HUSH_FUNCTIONS
4815 command->grp_type = GRP_SUBSHELL;
4820 char *as_string = NULL;
4822 pipe_list = parse_stream(&as_string, input, endch);
4825 o_addstr(&ctx->as_string, as_string);
4827 /* empty ()/{} or parse error? */
4828 if (!pipe_list || pipe_list == ERR_PTR) {
4833 debug_printf_parse("parse_group return 1: "
4834 "parse_stream returned %p\n", pipe_list);
4837 command->group = pipe_list;
4839 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4840 command->group_as_string = as_string;
4841 debug_printf_parse("end of group, remembering as:'%s'\n",
4842 command->group_as_string);
4845 debug_printf_parse("parse_group return 0\n");
4847 /* command remains "open", available for possible redirects */
4850 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4851 /* Subroutines for copying $(...) and `...` things */
4852 static void add_till_backquote(o_string *dest, struct in_str *input);
4854 static void add_till_single_quote(o_string *dest, struct in_str *input)
4857 int ch = i_getch(input);
4859 syntax_error_unterm_ch('\'');
4860 /*xfunc_die(); - redundant */
4867 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4868 static void add_till_double_quote(o_string *dest, struct in_str *input)
4871 int ch = i_getch(input);
4873 syntax_error_unterm_ch('"');
4874 /*xfunc_die(); - redundant */
4878 if (ch == '\\') { /* \x. Copy both chars. */
4880 ch = i_getch(input);
4884 add_till_backquote(dest, input);
4888 //if (ch == '$') ...
4891 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4893 * "Within the backquoted style of command substitution, backslash
4894 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4895 * The search for the matching backquote shall be satisfied by the first
4896 * backquote found without a preceding backslash; during this search,
4897 * if a non-escaped backquote is encountered within a shell comment,
4898 * a here-document, an embedded command substitution of the $(command)
4899 * form, or a quoted string, undefined results occur. A single-quoted
4900 * or double-quoted string that begins, but does not end, within the
4901 * "`...`" sequence produces undefined results."
4903 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4905 static void add_till_backquote(o_string *dest, struct in_str *input)
4908 int ch = i_getch(input);
4910 syntax_error_unterm_ch('`');
4911 /*xfunc_die(); - redundant */
4916 /* \x. Copy both chars unless it is \` */
4917 int ch2 = i_getch(input);
4919 syntax_error_unterm_ch('`');
4920 /*xfunc_die(); - redundant */
4922 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4929 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4930 * quoting and nested ()s.
4931 * "With the $(command) style of command substitution, all characters
4932 * following the open parenthesis to the matching closing parenthesis
4933 * constitute the command. Any valid shell script can be used for command,
4934 * except a script consisting solely of redirections which produces
4935 * unspecified results."
4937 * echo $(echo '(TEST)' BEST) (TEST) BEST
4938 * echo $(echo 'TEST)' BEST) TEST) BEST
4939 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4941 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4945 int ch = i_getch(input);
4947 syntax_error_unterm_ch(')');
4948 /*xfunc_die(); - redundant */
4956 if (i_peek(input) == ')') {
4964 add_till_single_quote(dest, input);
4969 add_till_double_quote(dest, input);
4974 /* \x. Copy verbatim. Important for \(, \) */
4975 ch = i_getch(input);
4977 syntax_error_unterm_ch(')');
4978 /*xfunc_die(); - redundant */
4985 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4987 /* Return code: 0 for OK, 1 for syntax error */
4989 #define handle_dollar(as_string, dest, input) \
4990 handle_dollar(dest, input)
4992 static int handle_dollar(o_string *as_string,
4994 struct in_str *input)
4997 int ch = i_peek(input); /* first character after the $ */
4998 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5000 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5002 ch = i_getch(input);
5003 nommu_addchr(as_string, ch);
5005 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5007 debug_printf_parse(": '%c'\n", ch);
5008 o_addchr(dest, ch | quote_mask);
5011 if (!isalnum(ch) && ch != '_')
5013 ch = i_getch(input);
5014 nommu_addchr(as_string, ch);
5016 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5017 } else if (isdigit(ch)) {
5019 ch = i_getch(input);
5020 nommu_addchr(as_string, ch);
5021 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5022 debug_printf_parse(": '%c'\n", ch);
5023 o_addchr(dest, ch | quote_mask);
5024 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5025 } else switch (ch) {
5027 case '!': /* last bg pid */
5028 case '?': /* last exit code */
5029 case '#': /* number of args */
5030 case '*': /* args */
5031 case '@': /* args */
5032 goto make_one_char_var;
5034 bool first_char, all_digits;
5036 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5037 ch = i_getch(input);
5038 nommu_addchr(as_string, ch);
5039 /* XXX maybe someone will try to escape the '}' */
5044 ch = i_getch(input);
5045 nommu_addchr(as_string, ch);
5051 /* ${#var}: length of var contents */
5053 else if (isdigit(ch)) {
5060 && ( (all_digits && !isdigit(ch))
5061 || (!all_digits && !isalnum(ch) && ch != '_')
5064 /* handle parameter expansions
5065 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5070 case ':': /* null modifier */
5071 if (expansion == 0) {
5072 debug_printf_parse(": null modifier\n");
5077 case '#': /* remove prefix */
5078 case '%': /* remove suffix */
5079 if (expansion == 0) {
5080 debug_printf_parse(": remove suffix/prefix\n");
5085 case '-': /* default value */
5086 case '=': /* assign default */
5087 case '+': /* alternative */
5088 case '?': /* error indicate */
5089 debug_printf_parse(": parameter expansion\n");
5094 syntax_error_unterm_str("${name}");
5095 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5100 debug_printf_parse(": '%c'\n", ch);
5101 o_addchr(dest, ch | quote_mask);
5105 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5108 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5113 ch = i_getch(input);
5114 nommu_addchr(as_string, ch);
5115 # if ENABLE_SH_MATH_SUPPORT
5116 if (i_peek(input) == '(') {
5117 ch = i_getch(input);
5118 nommu_addchr(as_string, ch);
5119 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5120 o_addchr(dest, /*quote_mask |*/ '+');
5124 add_till_closing_paren(dest, input, true);
5127 o_addstr(as_string, dest->data + pos);
5128 o_addchr(as_string, ')');
5129 o_addchr(as_string, ')');
5132 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5136 # if ENABLE_HUSH_TICK
5137 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5138 o_addchr(dest, quote_mask | '`');
5142 add_till_closing_paren(dest, input, false);
5145 o_addstr(as_string, dest->data + pos);
5146 o_addchr(as_string, '`');
5149 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5155 ch = i_getch(input);
5156 nommu_addchr(as_string, ch);
5158 if (isalnum(ch)) { /* it's $_name or $_123 */
5164 /* $_ Shell or shell script name; or last cmd name */
5165 /* $- Option flags set by set builtin or shell options (-i etc) */
5167 o_addQchr(dest, '$');
5169 debug_printf_parse("handle_dollar return 0\n");
5174 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5175 parse_stream_dquoted(dest, input, dquote_end)
5177 static int parse_stream_dquoted(o_string *as_string,
5179 struct in_str *input,
5186 ch = i_getch(input);
5188 nommu_addchr(as_string, ch);
5189 if (ch == dquote_end) { /* may be only '"' or EOF */
5190 if (dest->o_assignment == NOT_ASSIGNMENT)
5191 dest->o_escape ^= 1;
5192 debug_printf_parse("parse_stream_dquoted return 0\n");
5195 /* note: can't move it above ch == dquote_end check! */
5197 syntax_error_unterm_ch('"');
5198 /*xfunc_die(); - redundant */
5202 next = i_peek(input);
5204 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5205 ch, ch, dest->o_escape);
5208 syntax_error("\\<eof>");
5212 * "The backslash retains its special meaning [in "..."]
5213 * only when followed by one of the following characters:
5214 * $, `, ", \, or <newline>. A double quote may be quoted
5215 * within double quotes by preceding it with a backslash.
5217 if (strchr("$`\"\\", next) != NULL) {
5218 o_addqchr(dest, i_getch(input));
5220 o_addqchr(dest, '\\');
5225 if (handle_dollar(as_string, dest, input) != 0) {
5226 debug_printf_parse("parse_stream_dquoted return 1: "
5227 "handle_dollar returned non-0\n");
5232 #if ENABLE_HUSH_TICK
5234 //int pos = dest->length;
5235 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5236 o_addchr(dest, 0x80 | '`');
5237 add_till_backquote(dest, input);
5238 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5239 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5243 o_addQchr(dest, ch);
5245 && (dest->o_assignment == MAYBE_ASSIGNMENT
5246 || dest->o_assignment == WORD_IS_KEYWORD)
5247 && is_well_formed_var_name(dest->data, '=')
5249 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5255 * Scan input until EOF or end_trigger char.
5256 * Return a list of pipes to execute, or NULL on EOF
5257 * or if end_trigger character is met.
5258 * On syntax error, exit is shell is not interactive,
5259 * reset parsing machinery and start parsing anew,
5260 * or return ERR_PTR.
5262 static struct pipe *parse_stream(char **pstring,
5263 struct in_str *input,
5266 struct parse_context ctx;
5267 o_string dest = NULL_O_STRING;
5271 /* Double-quote state is handled in the state variable is_in_dquote.
5272 * A single-quote triggers a bypass of the main loop until its mate is
5273 * found. When recursing, quote state is passed in via dest->o_escape.
5275 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5276 end_trigger ? : 'X');
5279 G.ifs = get_local_var_value("IFS");
5284 #if ENABLE_HUSH_INTERACTIVE
5285 input->promptmode = 0; /* PS1 */
5287 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5288 initialize_context(&ctx);
5293 const char *is_special;
5297 redir_type redir_style;
5300 /* dest.o_quoted = 1; - already is (see below) */
5301 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5304 /* We reached closing '"' */
5307 ch = i_getch(input);
5308 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5309 ch, ch, dest.o_escape);
5314 syntax_error_unterm_str("here document");
5317 if (done_word(&dest, &ctx)) {
5321 done_pipe(&ctx, PIPE_SEQ);
5323 /* If we got nothing... */
5324 /* (this makes bare "&" cmd a no-op.
5325 * bash says: "syntax error near unexpected token '&'") */
5326 if (pi->num_cmds == 0
5327 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5333 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5335 *pstring = ctx.as_string.data;
5337 o_free_unsafe(&ctx.as_string);
5340 debug_printf_parse("parse_stream return %p\n", pi);
5343 nommu_addchr(&ctx.as_string, ch);
5344 is_ifs = strchr(G.ifs, ch);
5345 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5346 "\\$\"" USE_HUSH_TICK("`") /* always special */
5349 if (!is_special && !is_ifs) { /* ordinary char */
5350 o_addQchr(&dest, ch);
5351 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5352 || dest.o_assignment == WORD_IS_KEYWORD)
5354 && is_well_formed_var_name(dest.data, '=')
5356 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5362 if (done_word(&dest, &ctx)) {
5366 #if ENABLE_HUSH_CASE
5367 /* "case ... in <newline> word) ..." -
5368 * newlines are ignored (but ';' wouldn't be) */
5369 if (ctx.command->argv == NULL
5370 && ctx.ctx_res_w == RES_MATCH
5375 /* Treat newline as a command separator. */
5376 done_pipe(&ctx, PIPE_SEQ);
5377 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5379 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5384 dest.o_assignment = MAYBE_ASSIGNMENT;
5386 /* note: if (is_ifs) continue;
5387 * will still trigger for us */
5390 if (end_trigger && end_trigger == ch
5391 && (heredoc_cnt == 0 || end_trigger != ';')
5393 //TODO: disallow "{ cmd }" without semicolon
5395 /* This is technically valid:
5396 * { cat <<HERE; }; echo Ok
5401 * but we don't support this.
5402 * We require heredoc to be in enclosing {}/(),
5405 syntax_error_unterm_str("here document");
5408 if (done_word(&dest, &ctx)) {
5411 done_pipe(&ctx, PIPE_SEQ);
5412 dest.o_assignment = MAYBE_ASSIGNMENT;
5413 /* Do we sit outside of any if's, loops or case's? */
5415 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5419 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5421 *pstring = ctx.as_string.data;
5423 o_free_unsafe(&ctx.as_string);
5426 debug_printf_parse("parse_stream return %p: "
5427 "end_trigger char found\n",
5429 return ctx.list_head;
5437 next = i_peek(input);
5440 /* Catch <, > before deciding whether this word is
5441 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5444 redir_fd = redirect_opt_num(&dest);
5445 if (done_word(&dest, &ctx)) {
5448 redir_style = REDIRECT_OVERWRITE;
5450 redir_style = REDIRECT_APPEND;
5451 ch = i_getch(input);
5452 nommu_addchr(&ctx.as_string, ch);
5455 else if (next == '(') {
5456 syntax_error(">(process) not supported");
5460 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5462 continue; /* back to top of while (1) */
5464 redir_fd = redirect_opt_num(&dest);
5465 if (done_word(&dest, &ctx)) {
5468 redir_style = REDIRECT_INPUT;
5470 redir_style = REDIRECT_HEREDOC;
5472 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5473 ch = i_getch(input);
5474 nommu_addchr(&ctx.as_string, ch);
5475 } else if (next == '>') {
5476 redir_style = REDIRECT_IO;
5477 ch = i_getch(input);
5478 nommu_addchr(&ctx.as_string, ch);
5481 else if (next == '(') {
5482 syntax_error("<(process) not supported");
5486 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5488 continue; /* back to top of while (1) */
5491 if (dest.o_assignment == MAYBE_ASSIGNMENT
5492 /* check that we are not in word in "a=1 2>word b=1": */
5493 && !ctx.pending_redirect
5495 /* ch is a special char and thus this word
5496 * cannot be an assignment */
5497 dest.o_assignment = NOT_ASSIGNMENT;
5502 if (dest.length == 0) {
5505 if (ch == EOF || ch == '\n')
5508 /* note: we do not add it to &ctx.as_string */
5510 nommu_addchr(&ctx.as_string, '\n');
5512 o_addQchr(&dest, ch);
5517 syntax_error("\\<eof>");
5520 o_addchr(&dest, '\\');
5521 ch = i_getch(input);
5522 nommu_addchr(&ctx.as_string, ch);
5523 o_addchr(&dest, ch);
5524 /* Example: echo Hello \2>file
5525 * we need to know that word 2 is quoted */
5529 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5530 debug_printf_parse("parse_stream parse error: "
5531 "handle_dollar returned non-0\n");
5538 ch = i_getch(input);
5540 syntax_error_unterm_ch('\'');
5541 /*xfunc_die(); - redundant */
5543 nommu_addchr(&ctx.as_string, ch);
5546 if (dest.o_assignment == NOT_ASSIGNMENT)
5547 o_addqchr(&dest, ch);
5549 o_addchr(&dest, ch);
5554 is_in_dquote ^= 1; /* invert */
5555 if (dest.o_assignment == NOT_ASSIGNMENT)
5558 #if ENABLE_HUSH_TICK
5563 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5564 o_addchr(&dest, '`');
5568 add_till_backquote(&dest, input);
5570 o_addstr(&ctx.as_string, dest.data + pos);
5571 o_addchr(&ctx.as_string, '`');
5573 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5574 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5579 #if ENABLE_HUSH_CASE
5582 if (done_word(&dest, &ctx)) {
5585 done_pipe(&ctx, PIPE_SEQ);
5586 #if ENABLE_HUSH_CASE
5587 /* Eat multiple semicolons, detect
5588 * whether it means something special */
5593 ch = i_getch(input);
5594 nommu_addchr(&ctx.as_string, ch);
5595 if (ctx.ctx_res_w == RES_CASEI) {
5596 ctx.ctx_dsemicolon = 1;
5597 ctx.ctx_res_w = RES_MATCH;
5603 /* We just finished a cmd. New one may start
5604 * with an assignment */
5605 dest.o_assignment = MAYBE_ASSIGNMENT;
5608 if (done_word(&dest, &ctx)) {
5612 ch = i_getch(input);
5613 nommu_addchr(&ctx.as_string, ch);
5614 done_pipe(&ctx, PIPE_AND);
5616 done_pipe(&ctx, PIPE_BG);
5620 if (done_word(&dest, &ctx)) {
5623 #if ENABLE_HUSH_CASE
5624 if (ctx.ctx_res_w == RES_MATCH)
5625 break; /* we are in case's "word | word)" */
5627 if (next == '|') { /* || */
5628 ch = i_getch(input);
5629 nommu_addchr(&ctx.as_string, ch);
5630 done_pipe(&ctx, PIPE_OR);
5632 /* we could pick up a file descriptor choice here
5633 * with redirect_opt_num(), but bash doesn't do it.
5634 * "echo foo 2| cat" yields "foo 2". */
5639 #if ENABLE_HUSH_CASE
5640 /* "case... in [(]word)..." - skip '(' */
5641 if (ctx.ctx_res_w == RES_MATCH
5642 && ctx.command->argv == NULL /* not (word|(... */
5643 && dest.length == 0 /* not word(... */
5644 && dest.o_quoted == 0 /* not ""(... */
5650 if (parse_group(&dest, &ctx, input, ch) != 0) {
5655 #if ENABLE_HUSH_CASE
5656 if (ctx.ctx_res_w == RES_MATCH)
5660 /* proper use of this character is caught by end_trigger:
5661 * if we see {, we call parse_group(..., end_trigger='}')
5662 * and it will match } earlier (not here). */
5663 syntax_error_unexpected_ch(ch);
5667 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5673 struct parse_context *pctx;
5674 IF_HAS_KEYWORDS(struct parse_context *p2;)
5676 /* Clean up allocated tree.
5677 * Samples for finding leaks on syntax error recovery path.
5678 * Run them from interactive shell, watch pmap `pidof hush`.
5679 * while if false; then false; fi do break; done
5681 * while if false; then false; fi; do break; fi
5682 * Samples to catch leaks at execution:
5683 * while if (true | {true;}); then echo ok; fi; do break; done
5684 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5688 /* Update pipe/command counts,
5689 * otherwise freeing may miss some */
5690 done_pipe(pctx, PIPE_SEQ);
5691 debug_printf_clean("freeing list %p from ctx %p\n",
5692 pctx->list_head, pctx);
5693 debug_print_tree(pctx->list_head, 0);
5694 free_pipe_list(pctx->list_head);
5695 debug_printf_clean("freed list %p\n", pctx->list_head);
5697 o_free_unsafe(&pctx->as_string);
5699 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5703 IF_HAS_KEYWORDS(pctx = p2;)
5704 } while (HAS_KEYWORDS && pctx);
5705 /* Free text, clear all dest fields */
5707 /* If we are not in top-level parse, we return,
5708 * our caller will propagate error.
5710 if (end_trigger != ';') {
5718 /* Discard cached input, force prompt */
5720 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5725 /* Executing from string: eval, sh -c '...'
5726 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5727 * end_trigger controls how often we stop parsing
5728 * NUL: parse all, execute, return
5729 * ';': parse till ';' or newline, execute, repeat till EOF
5731 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5734 struct pipe *pipe_list;
5736 pipe_list = parse_stream(NULL, inp, end_trigger);
5737 if (!pipe_list) /* EOF */
5739 debug_print_tree(pipe_list, 0);
5740 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5741 run_and_free_list(pipe_list);
5745 static void parse_and_run_string(const char *s)
5747 struct in_str input;
5748 setup_string_in_str(&input, s);
5749 parse_and_run_stream(&input, '\0');
5752 static void parse_and_run_file(FILE *f)
5754 struct in_str input;
5755 setup_file_in_str(&input, f);
5756 parse_and_run_stream(&input, ';');
5759 /* Called a few times only (or even once if "sh -c") */
5760 static void block_signals(int second_time)
5765 mask = (1 << SIGQUIT);
5766 if (G_interactive_fd) {
5770 //TODO | (1 << SIGHUP)
5772 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5777 G.non_DFL_mask = mask;
5780 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5784 sigaddset(&G.blocked_set, sig);
5788 sigdelset(&G.blocked_set, SIGCHLD);
5790 sigprocmask(SIG_SETMASK, &G.blocked_set,
5791 second_time ? NULL : &G.inherited_set);
5792 /* POSIX allows shell to re-enable SIGCHLD
5793 * even if it was SIG_IGN on entry */
5794 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5796 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5801 static void maybe_set_to_sigexit(int sig)
5803 void (*handler)(int);
5804 /* non_DFL_mask'ed signals are, well, masked,
5805 * no need to set handler for them.
5807 if (!((G.non_DFL_mask >> sig) & 1)) {
5808 handler = signal(sig, sigexit);
5809 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5810 signal(sig, handler);
5813 /* Set handlers to restore tty pgrp and exit */
5814 static void set_fatal_handlers(void)
5816 /* We _must_ restore tty pgrp on fatal signals */
5818 maybe_set_to_sigexit(SIGILL );
5819 maybe_set_to_sigexit(SIGFPE );
5820 maybe_set_to_sigexit(SIGBUS );
5821 maybe_set_to_sigexit(SIGSEGV);
5822 maybe_set_to_sigexit(SIGTRAP);
5823 } /* else: hush is perfect. what SEGV? */
5824 maybe_set_to_sigexit(SIGABRT);
5825 /* bash 3.2 seems to handle these just like 'fatal' ones */
5826 maybe_set_to_sigexit(SIGPIPE);
5827 maybe_set_to_sigexit(SIGALRM);
5828 //TODO: disable and move down when proper SIGHUP handling is added
5829 maybe_set_to_sigexit(SIGHUP );
5830 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5831 * if we aren't interactive... but in this case
5832 * we never want to restore pgrp on exit, and this fn is not called */
5833 /*maybe_set_to_sigexit(SIGTERM);*/
5834 /*maybe_set_to_sigexit(SIGINT );*/
5838 static int set_mode(const char cstate, const char mode)
5840 int state = (cstate == '-' ? 1 : 0);
5842 case 'n': G.fake_mode = state; break;
5843 case 'x': /*G.debug_mode = state;*/ break;
5844 default: return EXIT_FAILURE;
5846 return EXIT_SUCCESS;
5849 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5850 int hush_main(int argc, char **argv)
5852 static const struct variable const_shell_ver = {
5854 .varstr = (char*)hush_version_str,
5855 .max_len = 1, /* 0 can provoke free(name) */
5859 int signal_mask_is_inited = 0;
5862 struct variable *cur_var;
5865 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5866 G.last_exitcode = EXIT_SUCCESS;
5868 G.argv0_for_re_execing = argv[0];
5870 /* Deal with HUSH_VERSION */
5871 G.shell_ver = const_shell_ver; /* copying struct here */
5872 G.top_var = &G.shell_ver;
5873 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5874 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5875 /* Initialize our shell local variables with the values
5876 * currently living in the environment */
5877 cur_var = G.top_var;
5880 char *value = strchr(*e, '=');
5881 if (value) { /* paranoia */
5882 cur_var->next = xzalloc(sizeof(*cur_var));
5883 cur_var = cur_var->next;
5884 cur_var->varstr = *e;
5885 cur_var->max_len = strlen(*e);
5886 cur_var->flg_export = 1;
5890 debug_printf_env("putenv '%s'\n", hush_version_str);
5891 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5892 #if ENABLE_FEATURE_EDITING
5893 G.line_input_state = new_line_input_t(FOR_SHELL);
5895 G.global_argc = argc;
5896 G.global_argv = argv;
5897 /* Initialize some more globals to non-zero values */
5899 #if ENABLE_HUSH_INTERACTIVE
5900 if (ENABLE_FEATURE_EDITING)
5901 cmdedit_set_initial_prompt();
5905 if (setjmp(die_jmp)) {
5906 /* xfunc has failed! die die die */
5907 /* no EXIT traps, this is an escape hatch! */
5909 hush_exit(xfunc_error_retval);
5912 /* Shell is non-interactive at first. We need to call
5913 * block_signals(0) if we are going to execute "sh <script>",
5914 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5915 * If we later decide that we are interactive, we run block_signals(0)
5916 * (or re-run block_signals(1) if we ran block_signals(0) before)
5917 * in order to intercept (more) signals.
5921 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5923 opt = getopt(argc, argv, "c:xins"
5926 # if ENABLE_HUSH_FUNCTIONS
5936 G.root_pid = getpid();
5937 G.global_argv = argv + optind;
5938 if (!argv[optind]) {
5939 /* -c 'script' (no params): prevent empty $0 */
5940 *--G.global_argv = argv[0];
5942 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5943 G.global_argc = argc - optind;
5944 block_signals(0); /* 0: called 1st time */
5945 parse_and_run_string(optarg);
5948 /* Well, we cannot just declare interactiveness,
5949 * we have to have some stuff (ctty, etc) */
5950 /* G_interactive_fd++; */
5953 /* "-s" means "read from stdin", but this is how we always
5954 * operate, so simply do nothing here. */
5957 case '<': /* "big heredoc" support */
5958 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5961 G.root_pid = bb_strtou(optarg, &optarg, 16);
5963 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5965 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5966 # if ENABLE_HUSH_LOOPS
5968 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5973 set_local_var(xstrdup(optarg), 0, opt == 'R');
5975 # if ENABLE_HUSH_FUNCTIONS
5977 struct function *funcp = new_function(optarg);
5978 /* funcp->name is already set to optarg */
5979 /* funcp->body is set to NULL. It's a special case. */
5980 funcp->body_as_string = argv[optind];
5988 if (!set_mode('-', opt))
5992 fprintf(stderr, "Usage: sh [FILE]...\n"
5993 " or: sh -c command [args]...\n\n");
5999 } /* option parsing loop */
6002 G.root_pid = getpid();
6004 /* If we are login shell... */
6005 if (argv[0] && argv[0][0] == '-') {
6007 /* XXX what should argv be while sourcing /etc/profile? */
6008 debug_printf("sourcing /etc/profile\n");
6009 input = fopen_for_read("/etc/profile");
6010 if (input != NULL) {
6011 close_on_exec_on(fileno(input));
6012 block_signals(0); /* 0: called 1st time */
6013 signal_mask_is_inited = 1;
6014 parse_and_run_file(input);
6017 /* bash: after sourcing /etc/profile,
6018 * tries to source (in the given order):
6019 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6020 * stopping of first found. --noprofile turns this off.
6021 * bash also sources ~/.bash_logout on exit.
6022 * If called as sh, skips .bash_XXX files.
6029 * "bash <script>" (which is never interactive (unless -i?))
6030 * sources $BASH_ENV here (without scanning $PATH).
6031 * If called as sh, does the same but with $ENV.
6033 debug_printf("running script '%s'\n", argv[optind]);
6034 G.global_argv = argv + optind;
6035 G.global_argc = argc - optind;
6036 input = xfopen_for_read(argv[optind]);
6037 close_on_exec_on(fileno(input));
6038 if (!signal_mask_is_inited)
6039 block_signals(0); /* 0: called 1st time */
6040 parse_and_run_file(input);
6041 #if ENABLE_FEATURE_CLEAN_UP
6047 /* Up to here, shell was non-interactive. Now it may become one.
6048 * NB: don't forget to (re)run block_signals(0/1) as needed.
6051 /* A shell is interactive if the '-i' flag was given, or if all of
6052 * the following conditions are met:
6054 * no arguments remaining or the -s flag given
6055 * standard input is a terminal
6056 * standard output is a terminal
6057 * Refer to Posix.2, the description of the 'sh' utility.
6060 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6061 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6062 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6063 //TODO: "interactive" and "have job control" are two different things.
6064 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6065 //should stay on! Currently, we mix these into one.
6066 if (G.saved_tty_pgrp >= 0) {
6067 /* try to dup stdin to high fd#, >= 255 */
6068 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6069 if (G_interactive_fd < 0) {
6070 /* try to dup to any fd */
6071 G_interactive_fd = dup(STDIN_FILENO);
6072 if (G_interactive_fd < 0)
6074 G_interactive_fd = 0;
6076 // TODO: track & disallow any attempts of user
6077 // to (inadvertently) close/redirect it
6080 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6081 if (G_interactive_fd) {
6084 /* We are indeed interactive shell, and we will perform
6085 * job control. Setting up for that. */
6087 close_on_exec_on(G_interactive_fd);
6088 /* If we were run as 'hush &', sleep until we are
6089 * in the foreground (tty pgrp == our pgrp).
6090 * If we get started under a job aware app (like bash),
6091 * make sure we are now in charge so we don't fight over
6092 * who gets the foreground */
6094 shell_pgrp = getpgrp();
6095 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6096 if (G.saved_tty_pgrp == shell_pgrp)
6098 /* send TTIN to ourself (should stop us) */
6099 kill(- shell_pgrp, SIGTTIN);
6101 /* Block some signals */
6102 block_signals(signal_mask_is_inited);
6103 /* Set other signals to restore saved_tty_pgrp */
6104 set_fatal_handlers();
6105 /* Put ourselves in our own process group */
6106 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6107 /* Grab control of the terminal */
6108 tcsetpgrp(G_interactive_fd, getpid());
6109 /* -1 is special - makes xfuncs longjmp, not exit
6110 * (we reset die_sleep = 0 whereever we [v]fork) */
6111 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6112 } else if (!signal_mask_is_inited) {
6113 block_signals(0); /* 0: called 1st time */
6114 } /* else: block_signals(0) was done before */
6115 #elif ENABLE_HUSH_INTERACTIVE
6116 /* No job control compiled in, only prompt/line editing */
6117 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6118 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6119 if (G_interactive_fd < 0) {
6120 /* try to dup to any fd */
6121 G_interactive_fd = dup(STDIN_FILENO);
6122 if (G_interactive_fd < 0)
6124 G_interactive_fd = 0;
6127 if (G_interactive_fd) {
6128 close_on_exec_on(G_interactive_fd);
6129 block_signals(signal_mask_is_inited);
6130 } else if (!signal_mask_is_inited) {
6134 /* We have interactiveness code disabled */
6135 if (!signal_mask_is_inited) {
6140 * if interactive but not a login shell, sources ~/.bashrc
6141 * (--norc turns this off, --rcfile <file> overrides)
6144 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6145 printf("\n\n%s hush - the humble shell\n", bb_banner);
6146 printf("Enter 'help' for a list of built-in commands.\n\n");
6149 parse_and_run_file(stdin);
6152 #if ENABLE_FEATURE_CLEAN_UP
6153 if (G.cwd != bb_msg_unknown)
6155 cur_var = G.top_var->next;
6157 struct variable *tmp = cur_var;
6158 if (!cur_var->max_len)
6159 free(cur_var->varstr);
6160 cur_var = cur_var->next;
6164 hush_exit(G.last_exitcode);
6169 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6170 int lash_main(int argc, char **argv)
6172 //bb_error_msg("lash is deprecated, please use hush instead");
6173 return hush_main(argc, argv);
6181 static int builtin_trap(char **argv)
6188 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6192 /* No args: print all trapped. This isn't 100% correct as we
6193 * should be escaping the cmd so that it can be pasted back in
6195 for (i = 0; i < NSIG; ++i)
6197 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
6198 return EXIT_SUCCESS;
6203 /* If first arg is decimal: reset all specified signals */
6204 sig = bb_strtou(*argv, NULL, 10);
6210 sig = get_signum(*argv++);
6211 if (sig < 0 || sig >= NSIG) {
6213 /* Mimic bash message exactly */
6214 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
6219 G.traps[sig] = xstrdup(new_cmd);
6221 debug_printf("trap: setting SIG%s (%i) to '%s'",
6222 get_signame(sig), sig, G.traps[sig]);
6224 /* There is no signal for 0 (EXIT) */
6229 sigaddset(&G.blocked_set, sig);
6231 /* There was a trap handler, we are removing it
6232 * (if sig has non-DFL handling,
6233 * we don't need to do anything) */
6234 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6236 sigdelset(&G.blocked_set, sig);
6238 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6243 /* First arg is "-": reset all specified to default */
6244 /* First arg is "": ignore all specified */
6245 /* Everything else: execute first arg upon signal */
6247 bb_error_msg("trap: invalid arguments");
6248 return EXIT_FAILURE;
6250 if (NOT_LONE_DASH(*argv))
6256 static int builtin_true(char **argv UNUSED_PARAM)
6261 static int builtin_test(char **argv)
6268 return test_main(argc, argv - argc);
6271 static int builtin_echo(char **argv)
6278 return echo_main(argc, argv - argc);
6281 static int builtin_eval(char **argv)
6283 int rcode = EXIT_SUCCESS;
6286 char *str = expand_strvec_to_string(argv);
6288 * eval "echo Hi; done" ("done" is syntax error):
6289 * "echo Hi" will not execute too.
6291 parse_and_run_string(str);
6293 rcode = G.last_exitcode;
6298 static int builtin_cd(char **argv)
6300 const char *newdir = argv[1];
6301 if (newdir == NULL) {
6302 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6303 * bash says "bash: cd: HOME not set" and does nothing
6306 newdir = getenv("HOME") ? : "/";
6308 if (chdir(newdir)) {
6309 /* Mimic bash message exactly */
6310 bb_perror_msg("cd: %s", newdir);
6311 return EXIT_FAILURE;
6314 return EXIT_SUCCESS;
6317 static int builtin_exec(char **argv)
6319 if (*++argv == NULL)
6320 return EXIT_SUCCESS; /* bash does this */
6325 // FIXME: if exec fails, bash does NOT exit! We do...
6326 pseudo_exec_argv(&dummy, argv, 0, NULL);
6331 static int builtin_exit(char **argv)
6333 debug_printf_exec("%s()\n", __func__);
6334 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6335 //puts("exit"); /* bash does it */
6336 // TODO: warn if we have background jobs: "There are stopped jobs"
6337 // On second consecutive 'exit', exit anyway.
6338 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6340 /* note: EXIT trap is run by hush_exit */
6341 if (*++argv == NULL)
6342 hush_exit(G.last_exitcode);
6343 /* mimic bash: exit 123abc == exit 255 + error msg */
6344 xfunc_error_retval = 255;
6345 /* bash: exit -2 == exit 254, no error msg */
6346 hush_exit(xatoi(*argv) & 0xff);
6349 static int builtin_export(char **argv)
6351 if (*++argv == NULL) {
6358 /* ash emits: export VAR='VAL'
6359 * bash: declare -x VAR="VAL"
6360 * we follow ash example */
6361 const char *s = *e++;
6362 const char *p = strchr(s, '=');
6364 if (!p) /* wtf? take next variable */
6367 printf("export %.*s", (int)(p - s) + 1, s);
6371 p = strchrnul(s, '\'');
6373 printf("'%.*s'", (int)(p - s), s);
6378 /* s points to '; print ''...'''" */
6380 do putchar('\''); while (*++s == '\'');
6388 return EXIT_SUCCESS;
6395 value = strchr(name, '=');
6397 /* They are exporting something without a =VALUE */
6398 struct variable *var;
6400 var = get_local_var(name);
6402 var->flg_export = 1;
6403 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6404 putenv(var->varstr);
6406 /* bash does not return an error when trying to export
6407 * an undefined variable. Do likewise. */
6410 set_local_var(xstrdup(name), 1, 0);
6413 return EXIT_SUCCESS;
6417 /* built-in 'fg' and 'bg' handler */
6418 static int builtin_fg_bg(char **argv)
6423 if (!G_interactive_fd)
6424 return EXIT_FAILURE;
6425 /* If they gave us no args, assume they want the last backgrounded task */
6427 for (pi = G.job_list; pi; pi = pi->next) {
6428 if (pi->jobid == G.last_jobid) {
6432 bb_error_msg("%s: no current job", argv[0]);
6433 return EXIT_FAILURE;
6435 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6436 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6437 return EXIT_FAILURE;
6439 for (pi = G.job_list; pi; pi = pi->next) {
6440 if (pi->jobid == jobnum) {
6444 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6445 return EXIT_FAILURE;
6447 // TODO: bash prints a string representation
6448 // of job being foregrounded (like "sleep 1 | cat")
6449 if (argv[0][0] == 'f') {
6450 /* Put the job into the foreground. */
6451 tcsetpgrp(G_interactive_fd, pi->pgrp);
6454 /* Restart the processes in the job */
6455 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6456 for (i = 0; i < pi->num_cmds; i++) {
6457 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6458 pi->cmds[i].is_stopped = 0;
6460 pi->stopped_cmds = 0;
6462 i = kill(- pi->pgrp, SIGCONT);
6464 if (errno == ESRCH) {
6465 delete_finished_bg_job(pi);
6466 return EXIT_SUCCESS;
6468 bb_perror_msg("kill (SIGCONT)");
6471 if (argv[0][0] == 'f') {
6473 return checkjobs_and_fg_shell(pi);
6475 return EXIT_SUCCESS;
6479 #if ENABLE_HUSH_HELP
6480 static int builtin_help(char **argv UNUSED_PARAM)
6482 const struct built_in_command *x;
6485 "Built-in commands:\n"
6486 "------------------\n");
6487 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6488 printf("%s\t%s\n", x->cmd, x->descr);
6491 return EXIT_SUCCESS;
6496 static int builtin_jobs(char **argv UNUSED_PARAM)
6499 const char *status_string;
6501 for (job = G.job_list; job; job = job->next) {
6502 if (job->alive_cmds == job->stopped_cmds)
6503 status_string = "Stopped";
6505 status_string = "Running";
6507 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6509 return EXIT_SUCCESS;
6514 static int builtin_memleak(char **argv UNUSED_PARAM)
6519 /* Crude attempt to find where "free memory" starts,
6520 * sans fragmentation. */
6522 l = (unsigned long)p;
6525 if (l < (unsigned long)p) l = (unsigned long)p;
6528 if (!G.memleak_value)
6529 G.memleak_value = l;
6531 l -= G.memleak_value;
6538 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6543 static int builtin_pwd(char **argv UNUSED_PARAM)
6546 return EXIT_SUCCESS;
6549 static int builtin_read(char **argv)
6552 const char *name = "REPLY";
6556 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6557 * and _after_ that_ it will complain */
6558 if (!is_well_formed_var_name(name, '\0')) {
6559 /* Mimic bash message */
6560 bb_error_msg("read: '%s': not a valid identifier", name);
6565 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6567 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6568 return set_local_var(string, 0, 0);
6571 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6572 * built-in 'set' handler
6574 * set [-abCefhmnuvx] [-o option] [argument...]
6575 * set [+abCefhmnuvx] [+o option] [argument...]
6576 * set -- [argument...]
6579 * Implementations shall support the options in both their hyphen and
6580 * plus-sign forms. These options can also be specified as options to sh.
6582 * Write out all variables and their values: set
6583 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6584 * Turn on the -x and -v options: set -xv
6585 * Unset all positional parameters: set --
6586 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6587 * Set the positional parameters to the expansion of x, even if x expands
6588 * with a leading '-' or '+': set -- $x
6590 * So far, we only support "set -- [argument...]" and some of the short names.
6592 static int builtin_set(char **argv)
6595 char **pp, **g_argv;
6596 char *arg = *++argv;
6600 for (e = G.top_var; e; e = e->next)
6602 return EXIT_SUCCESS;
6606 if (!strcmp(arg, "--")) {
6610 if (arg[0] != '+' && arg[0] != '-')
6612 for (n = 1; arg[n]; ++n)
6613 if (set_mode(arg[0], arg[n]))
6615 } while ((arg = *++argv) != NULL);
6616 /* Now argv[0] is 1st argument */
6619 return EXIT_SUCCESS;
6622 /* NB: G.global_argv[0] ($0) is never freed/changed */
6623 g_argv = G.global_argv;
6624 if (G.global_args_malloced) {
6630 G.global_args_malloced = 1;
6631 pp = xzalloc(sizeof(pp[0]) * 2);
6632 pp[0] = g_argv[0]; /* retain $0 */
6635 /* This realloc's G.global_argv */
6636 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6643 return EXIT_SUCCESS;
6645 /* Nothing known, so abort */
6647 bb_error_msg("set: %s: invalid option", arg);
6648 return EXIT_FAILURE;
6651 static int builtin_shift(char **argv)
6657 if (n >= 0 && n < G.global_argc) {
6658 if (G.global_args_malloced) {
6661 free(G.global_argv[m++]);
6664 memmove(&G.global_argv[1], &G.global_argv[n+1],
6665 G.global_argc * sizeof(G.global_argv[0]));
6666 return EXIT_SUCCESS;
6668 return EXIT_FAILURE;
6671 static int builtin_source(char **argv)
6675 if (*++argv == NULL)
6676 return EXIT_FAILURE;
6678 /* XXX search through $PATH is missing */
6679 input = fopen_or_warn(*argv, "r");
6681 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6682 return EXIT_FAILURE;
6684 close_on_exec_on(fileno(input));
6686 /* Now run the file */
6688 /* XXX argv and argc are broken; need to save old G.global_argv
6689 * (pointer only is OK!) on this stack frame,
6690 * set G.global_argv=argv+1, recurse, and restore. */
6691 parse_and_run_file(input);
6693 return G.last_exitcode;
6696 static int builtin_umask(char **argv)
6699 const char *arg = argv[1];
6701 //TODO: umask may take chmod-like symbolic masks
6702 new_umask = bb_strtou(arg, NULL, 8);
6704 //Message? bash examples:
6705 //bash: umask: 'q': invalid symbolic mode operator
6706 //bash: umask: 999: octal number out of range
6707 return EXIT_FAILURE;
6710 new_umask = umask(0);
6711 printf("%.3o\n", (unsigned) new_umask);
6712 /* fall through and restore new_umask which we set to 0 */
6715 return EXIT_SUCCESS;
6718 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6719 static int builtin_unset(char **argv)
6725 return EXIT_SUCCESS;
6728 if (argv[0][0] == '-') {
6729 switch (argv[0][1]) {
6735 bb_error_msg("unset: %s: invalid option", *argv);
6736 return EXIT_FAILURE;
6738 //TODO: disallow "unset -vf ..." too
6745 if (unset_local_var(*argv)) {
6746 /* unset <nonexistent_var> doesn't fail.
6747 * Error is when one tries to unset RO var.
6748 * Message was printed by unset_local_var. */
6752 //#if ENABLE_HUSH_FUNCTIONS
6754 // unset_local_func(*argv);
6762 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6763 static int builtin_wait(char **argv)
6765 int ret = EXIT_SUCCESS;
6768 if (*++argv == NULL) {
6769 /* Don't care about wait results */
6770 /* Note 1: must wait until there are no more children */
6771 /* Note 2: must be interruptible */
6773 * $ sleep 3 & sleep 6 & wait
6778 * $ sleep 3 & sleep 6 & wait
6782 * ^C <-- after ~4 sec from keyboard
6785 sigaddset(&G.blocked_set, SIGCHLD);
6786 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6789 if (errno == ECHILD)
6791 /* Wait for SIGCHLD or any other signal of interest */
6792 /* sigtimedwait with infinite timeout: */
6793 sig = sigwaitinfo(&G.blocked_set, NULL);
6795 sig = check_and_run_traps(sig);
6796 if (sig && sig != SIGCHLD) { /* see note 2 */
6802 sigdelset(&G.blocked_set, SIGCHLD);
6803 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6807 /* This is probably buggy wrt interruptible-ness */
6809 pid_t pid = bb_strtou(*argv, NULL, 10);
6811 /* mimic bash message */
6812 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6813 return EXIT_FAILURE;
6815 if (waitpid(pid, &status, 0) == pid) {
6816 if (WIFSIGNALED(status))
6817 ret = 128 + WTERMSIG(status);
6818 else if (WIFEXITED(status))
6819 ret = WEXITSTATUS(status);
6823 bb_perror_msg("wait %s", *argv);
6832 #if ENABLE_HUSH_LOOPS
6833 static int builtin_break(char **argv)
6835 if (G.depth_of_loop == 0) {
6836 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6837 return EXIT_SUCCESS; /* bash compat */
6839 G.flag_break_continue++; /* BC_BREAK = 1 */
6840 G.depth_break_continue = 1;
6842 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6843 if (errno || !G.depth_break_continue || argv[2]) {
6844 bb_error_msg("%s: bad arguments", argv[0]);
6845 G.flag_break_continue = BC_BREAK;
6846 G.depth_break_continue = UINT_MAX;
6849 if (G.depth_of_loop < G.depth_break_continue)
6850 G.depth_break_continue = G.depth_of_loop;
6851 return EXIT_SUCCESS;
6854 static int builtin_continue(char **argv)
6856 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6857 return builtin_break(argv);