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 * $var refs in function do not pick up values set by "var=val func"
55 * builtins: return, ulimit
56 * follow IFS rules more precisely, including update semantics
57 * figure out what to do with backslash-newline
58 * continuation lines, both explicit and implicit - done?
60 * 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.
153 typedef struct nommu_save_t {
157 char **argv_from_re_execing;
161 /* The descrip member of this structure is only used to make
162 * debugging output pretty */
163 static const struct {
165 signed char default_fd;
169 { O_RDONLY, 0, "<" },
170 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
171 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
172 { O_RDONLY, 0, "<<" },
173 { O_CREAT|O_RDWR, 1, "<>" },
174 /* Should not be needed. Bogus default_fd helps in debugging */
175 /* { O_RDONLY, 77, "<<" }, */
178 typedef enum reserved_style {
187 #if ENABLE_HUSH_LOOPS
194 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
199 /* two pseudo-keywords support contrived "case" syntax: */
200 RES_MATCH , /* "word)" */
201 RES_CASEI , /* "this command is inside CASE" */
208 typedef struct o_string {
210 int length; /* position where data is appended */
212 /* Protect newly added chars against globbing
213 * (by prepending \ to *, ?, [, \) */
216 /* At least some part of the string was inside '' or "",
217 * possibly empty one: word"", wo''rd etc. */
219 smallint has_empty_slot;
220 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
223 MAYBE_ASSIGNMENT = 0,
224 DEFINITELY_ASSIGNMENT = 1,
226 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
228 /* Used for initialization: o_string foo = NULL_O_STRING; */
229 #define NULL_O_STRING { NULL }
231 /* I can almost use ordinary FILE*. Is open_memstream() universally
232 * available? Where is it documented? */
233 typedef struct in_str {
235 /* eof_flag=1: last char in ->p is really an EOF */
236 char eof_flag; /* meaningless if ->p == NULL */
238 #if ENABLE_HUSH_INTERACTIVE
240 smallint promptmode; /* 0: PS1, 1: PS2 */
243 int (*get) (struct in_str *);
244 int (*peek) (struct in_str *);
246 #define i_getch(input) ((input)->get(input))
247 #define i_peek(input) ((input)->peek(input))
249 struct redir_struct {
250 struct redir_struct *next;
251 char *rd_filename; /* filename */
252 int rd_fd; /* fd to redirect */
253 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
255 smallint rd_type; /* (enum redir_type) */
256 /* note: for heredocs, rd_filename contains heredoc delimiter,
257 * and subsequently heredoc itself; and rd_dup is a bitmask:
258 * 1: do we need to trim leading tabs?
259 * 2: is heredoc quoted (<<'delim' syntax) ?
262 typedef enum redir_type {
263 REDIRECT_INVALID = 0,
265 REDIRECT_OVERWRITE = 2,
267 REDIRECT_HEREDOC = 4,
269 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
272 REDIRFD_SYNTAX_ERR = -2,
273 REDIRFD_TO_FILE = -1,
274 /* otherwise, rd_fd is redirected to rd_dup */
276 HEREDOC_SKIPTABS = 1,
282 pid_t pid; /* 0 if exited */
283 int assignment_cnt; /* how many argv[i] are assignments? */
284 smallint is_stopped; /* is the command currently running? */
285 smallint grp_type; /* GRP_xxx */
287 #define GRP_SUBSHELL 1
288 #if ENABLE_HUSH_FUNCTIONS
289 # define GRP_FUNCTION 2
291 struct pipe *group; /* if non-NULL, this "command" is { list },
292 * ( list ), or a compound statement */
294 char *group_as_string;
296 #if ENABLE_HUSH_FUNCTIONS
297 struct function *child_func;
298 /* This field is used to prevent a bug here:
299 * while...do f1() {a;}; f1; f1 {b;}; f1; done
300 * When we execute "f1() {a;}" cmd, we create new function and clear
301 * cmd->group, cmd->group_as_string, cmd->argv[0].
302 * when we execute "f1 {b;}", we notice that f1 exists,
303 * and that it's "parent cmd" struct is still "alive",
304 * we put those fields back into cmd->xxx
305 * (struct function has ->parent_cmd ptr to facilitate that).
306 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
307 * Without this trick, loop would execute a;b;b;b;...
308 * instead of correct sequence a;b;a;b;...
309 * When command is freed, it severs the link
310 * (sets ->child_func->parent_cmd to NULL).
313 char **argv; /* command name and arguments */
314 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
315 * and on execution these are substituted with their values.
316 * Substitution can make _several_ words out of one argv[n]!
317 * Example: argv[0]=='.^C*^C.' here: echo .$*.
318 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
320 struct redir_struct *redirects; /* I/O redirections */
322 /* Is there anything in this command at all? */
323 #define IS_NULL_CMD(cmd) \
324 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
329 int num_cmds; /* total number of commands in pipe */
330 int alive_cmds; /* number of commands running (not exited) */
331 int stopped_cmds; /* number of commands alive, but stopped */
333 int jobid; /* job number */
334 pid_t pgrp; /* process group ID for the job */
335 char *cmdtext; /* name of job */
337 struct command *cmds; /* array of commands in pipe */
338 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
339 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
340 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
342 typedef enum pipe_style {
348 /* Is there anything in this pipe at all? */
349 #define IS_NULL_PIPE(pi) \
350 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
352 /* This holds pointers to the various results of parsing */
353 struct parse_context {
354 /* linked list of pipes */
355 struct pipe *list_head;
356 /* last pipe (being constructed right now) */
358 /* last command in pipe (being constructed right now) */
359 struct command *command;
360 /* last redirect in command->redirects list */
361 struct redir_struct *pending_redirect;
367 smallint ctx_inverted; /* "! cmd | cmd" */
369 smallint ctx_dsemicolon; /* ";;" seen */
371 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
373 /* group we are enclosed in:
374 * example: "if pipe1; pipe2; then pipe3; fi"
375 * when we see "if" or "then", we malloc and copy current context,
376 * and make ->stack point to it. then we parse pipeN.
377 * when closing "then" / fi" / whatever is found,
378 * we move list_head into ->stack->command->group,
379 * copy ->stack into current context, and delete ->stack.
380 * (parsing of { list } and ( list ) doesn't use this method)
382 struct parse_context *stack;
386 /* On program start, environ points to initial environment.
387 * putenv adds new pointers into it, unsetenv removes them.
388 * Neither of these (de)allocates the strings.
389 * setenv allocates new strings in malloc space and does putenv,
390 * and thus setenv is unusable (leaky) for shell's purposes */
391 #define setenv(...) setenv_is_leaky_dont_use()
393 struct variable *next;
394 char *varstr; /* points to "name=" portion */
395 int max_len; /* if > 0, name is part of initial env; else name is malloced */
396 smallint flg_export; /* putenv should be done on this var */
397 smallint flg_read_only;
405 #if ENABLE_HUSH_FUNCTIONS
407 struct function *next;
409 struct command *parent_cmd;
412 char *body_as_string;
418 /* "Globals" within this file */
419 /* Sorted roughly by size (smaller offsets == smaller code) */
421 #if ENABLE_HUSH_INTERACTIVE
422 /* 'interactive_fd' is a fd# open to ctty, if we have one
423 * _AND_ if we decided to act interactively */
427 #define G_interactive_fd (G.interactive_fd)
429 #define G_interactive_fd 0
431 #if ENABLE_FEATURE_EDITING
432 line_input_t *line_input_state;
438 pid_t saved_tty_pgrp;
440 struct pipe *job_list;
441 struct pipe *toplevel_list;
443 smallint flag_SIGINT;
444 #if ENABLE_HUSH_LOOPS
445 smallint flag_break_continue;
448 smallint exiting; /* used to prevent EXIT trap recursion */
449 /* These four support $?, $#, and $1 */
450 smalluint last_exitcode;
451 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
452 smalluint global_args_malloced;
453 /* how many non-NULL argv's we have. NB: $# + 1 */
457 char *argv0_for_re_execing;
459 #if ENABLE_HUSH_LOOPS
460 unsigned depth_break_continue;
461 unsigned depth_of_loop;
465 struct variable *top_var; /* = &G.shell_ver (set in main()) */
466 struct variable shell_ver;
467 #if ENABLE_HUSH_FUNCTIONS
468 struct function *top_func;
470 /* Signal and trap handling */
471 // unsigned count_SIGCHLD;
472 // unsigned handled_SIGCHLD;
473 /* which signals have non-DFL handler (even with no traps set)? */
474 unsigned non_DFL_mask;
475 char **traps; /* char *traps[NSIG] */
476 sigset_t blocked_set;
477 sigset_t inherited_set;
479 unsigned long memleak_value;
482 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
484 #define G (*ptr_to_globals)
485 /* Not #defining name to G.name - this quickly gets unwieldy
486 * (too many defines). Also, I actually prefer to see when a variable
487 * is global, thus "G." prefix is a useful hint */
488 #define INIT_G() do { \
489 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
493 /* Function prototypes for builtins */
494 static int builtin_cd(char **argv);
495 static int builtin_echo(char **argv);
496 static int builtin_eval(char **argv);
497 static int builtin_exec(char **argv);
498 static int builtin_exit(char **argv);
499 static int builtin_export(char **argv);
501 static int builtin_fg_bg(char **argv);
502 static int builtin_jobs(char **argv);
505 static int builtin_help(char **argv);
508 static int builtin_memleak(char **argv);
510 static int builtin_pwd(char **argv);
511 static int builtin_read(char **argv);
512 static int builtin_set(char **argv);
513 static int builtin_shift(char **argv);
514 static int builtin_source(char **argv);
515 static int builtin_test(char **argv);
516 static int builtin_trap(char **argv);
517 static int builtin_true(char **argv);
518 static int builtin_umask(char **argv);
519 static int builtin_unset(char **argv);
520 static int builtin_wait(char **argv);
521 #if ENABLE_HUSH_LOOPS
522 static int builtin_break(char **argv);
523 static int builtin_continue(char **argv);
526 /* Table of built-in functions. They can be forked or not, depending on
527 * context: within pipes, they fork. As simple commands, they do not.
528 * When used in non-forking context, they can change global variables
529 * in the parent shell process. If forked, of course they cannot.
530 * For example, 'unset foo | whatever' will parse and run, but foo will
531 * still be set at the end. */
532 struct built_in_command {
534 int (*function)(char **argv);
537 #define BLTIN(cmd, func, help) { cmd, func, help }
539 #define BLTIN(cmd, func, help) { cmd, func }
543 /* For now, echo and test are unconditionally enabled.
544 * Maybe make it configurable? */
545 static const struct built_in_command bltins[] = {
546 BLTIN("." , builtin_source , "Run commands in a file"),
547 BLTIN(":" , builtin_true , "No-op"),
548 BLTIN("[" , builtin_test , "Test condition"),
550 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
552 #if ENABLE_HUSH_LOOPS
553 BLTIN("break" , builtin_break , "Exit from a loop"),
555 BLTIN("cd" , builtin_cd , "Change directory"),
556 #if ENABLE_HUSH_LOOPS
557 BLTIN("continue", builtin_continue, "Start new loop iteration"),
559 BLTIN("echo" , builtin_echo , "Write to stdout"),
560 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
561 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
562 BLTIN("exit" , builtin_exit , "Exit"),
563 BLTIN("export" , builtin_export , "Set environment variable"),
565 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
568 BLTIN("help" , builtin_help , "List shell built-in commands"),
571 BLTIN("jobs" , builtin_jobs , "List active jobs"),
574 BLTIN("memleak" , builtin_memleak , "Debug tool"),
576 BLTIN("pwd" , builtin_pwd , "Print current directory"),
577 BLTIN("read" , builtin_read , "Input environment variable"),
578 // BLTIN("return" , builtin_return , "Return from a function"),
579 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
580 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
581 BLTIN("test" , builtin_test , "Test condition"),
582 BLTIN("trap" , builtin_trap , "Trap signals"),
583 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
584 BLTIN("umask" , builtin_umask , "Set file creation mask"),
585 BLTIN("unset" , builtin_unset , "Unset environment variable"),
586 BLTIN("wait" , builtin_wait , "Wait for process"),
593 /* prevent disasters with G.debug_indent < 0 */
594 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
595 # define debug_enter() (G.debug_indent++)
596 # define debug_leave() (G.debug_indent--)
598 # define indent() ((void)0)
599 # define debug_enter() ((void)0)
600 # define debug_leave() ((void)0)
604 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
607 #ifndef debug_printf_parse
608 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
611 #ifndef debug_printf_exec
612 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
615 #ifndef debug_printf_env
616 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
619 #ifndef debug_printf_jobs
620 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
621 # define DEBUG_JOBS 1
623 # define DEBUG_JOBS 0
626 #ifndef debug_printf_expand
627 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
628 # define DEBUG_EXPAND 1
630 # define DEBUG_EXPAND 0
633 #ifndef debug_printf_glob
634 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
635 # define DEBUG_GLOB 1
637 # define DEBUG_GLOB 0
640 #ifndef debug_printf_list
641 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
644 #ifndef debug_printf_subst
645 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
648 #ifndef debug_printf_clean
649 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
650 # define DEBUG_CLEAN 1
652 # define DEBUG_CLEAN 0
656 static void debug_print_strings(const char *prefix, char **vv)
659 fprintf(stderr, "%s:\n", prefix);
661 fprintf(stderr, " '%s'\n", *vv++);
664 #define debug_print_strings(prefix, vv) ((void)0)
668 /* Leak hunting. Use hush_leaktool.sh for post-processing.
671 static void *xxmalloc(int lineno, size_t size)
673 void *ptr = xmalloc((size + 0xff) & ~0xff);
674 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
677 static void *xxrealloc(int lineno, void *ptr, size_t size)
679 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
680 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
683 static char *xxstrdup(int lineno, const char *str)
685 char *ptr = xstrdup(str);
686 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
689 static void xxfree(void *ptr)
691 fdprintf(2, "free %p\n", ptr);
694 #define xmalloc(s) xxmalloc(__LINE__, s)
695 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
696 #define xstrdup(s) xxstrdup(__LINE__, s)
697 #define free(p) xxfree(p)
701 /* Syntax and runtime errors. They always abort scripts.
702 * In interactive use they usually discard unparsed and/or unexecuted commands
703 * and return to the prompt.
704 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
707 # define die_if_script(lineno, fmt...) die_if_script(fmt)
708 # define syntax_error(lineno, msg) syntax_error(msg)
709 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
710 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
711 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
712 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
715 static void die_if_script(unsigned lineno, const char *fmt, ...)
720 bb_error_msg("hush.c:%u", lineno);
723 bb_verror_msg(fmt, p, NULL);
725 if (!G_interactive_fd)
729 static void syntax_error(unsigned lineno, const char *msg)
732 die_if_script(lineno, "syntax error: %s", msg);
734 die_if_script(lineno, "syntax error", NULL);
737 static void syntax_error_at(unsigned lineno, const char *msg)
739 die_if_script(lineno, "syntax error at '%s'", msg);
742 /* It so happens that all such cases are totally fatal
743 * even if shell is interactive: EOF while looking for closing
744 * delimiter. There is nowhere to read stuff from after that,
745 * it's EOF! The only choice is to terminate.
747 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
748 static void syntax_error_unterm_ch(unsigned lineno, char ch)
753 die_if_script(lineno, "syntax error: unterminated %s", msg);
757 static void syntax_error_unterm_str(unsigned lineno, const char *s)
759 die_if_script(lineno, "syntax error: unterminated %s", s);
762 static void syntax_error_unexpected_ch(unsigned lineno, char ch)
767 die_if_script(lineno, "syntax error: unexpected %s", msg);
771 # undef die_if_script
773 # undef syntax_error_at
774 # undef syntax_error_unterm_ch
775 # undef syntax_error_unterm_str
776 # undef syntax_error_unexpected_ch
778 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
779 # define syntax_error(msg) syntax_error(__LINE__, msg)
780 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
781 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
782 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
783 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
789 static int glob_needed(const char *s)
794 if (*s == '*' || *s == '[' || *s == '?')
801 static int is_well_formed_var_name(const char *s, char terminator)
803 if (!s || !(isalpha(*s) || *s == '_'))
806 while (isalnum(*s) || *s == '_')
808 return *s == terminator;
811 /* Replace each \x with x in place, return ptr past NUL. */
812 static char *unbackslash(char *src)
818 if ((*dst++ = *src++) == '\0')
824 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
845 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
846 v[count1 + count2] = NULL;
849 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
853 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
855 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
856 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
859 #define add_strings_to_strings(strings, add, need_to_dup) \
860 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
863 static char **add_string_to_strings(char **strings, char *add)
868 return add_strings_to_strings(strings, v, /*dup:*/ 0);
871 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
873 char **ptr = add_string_to_strings(strings, add);
874 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
877 #define add_string_to_strings(strings, add) \
878 xx_add_string_to_strings(__LINE__, strings, add)
881 static void putenv_all(char **strings)
886 debug_printf_env("putenv '%s'\n", *strings);
891 static char **putenv_all_and_save_old(char **strings)
901 eq = strchr(*strings, '=');
904 v = getenv(*strings);
907 /* v points to VAL in VAR=VAL, go back to VAR */
908 v -= (eq - *strings) + 1;
909 old = add_string_to_strings(old, v);
918 static void free_strings_and_unsetenv(char **strings, int unset)
928 debug_printf_env("unsetenv '%s'\n", *v);
936 static void free_strings(char **strings)
938 free_strings_and_unsetenv(strings, 0);
942 /* Basic theory of signal handling in shell
943 * ========================================
944 * This does not describe what hush does, rather, it is current understanding
945 * what it _should_ do. If it doesn't, it's a bug.
946 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
948 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
949 * is finished or backgrounded. It is the same in interactive and
950 * non-interactive shells, and is the same regardless of whether
951 * a user trap handler is installed or a shell special one is in effect.
952 * ^C or ^Z from keyboard seem to execute "at once" because it usually
953 * backgrounds (i.e. stops) or kills all members of currently running
956 * Wait builtin in interruptible by signals for which user trap is set
957 * or by SIGINT in interactive shell.
959 * Trap handlers will execute even within trap handlers. (right?)
961 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
963 * If job control is off, backgrounded commands ("cmd &")
964 * have SIGINT, SIGQUIT set to SIG_IGN.
966 * Commands run in command substitution ("`cmd`")
967 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
969 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
970 * by the shell from its parent.
972 * Siganls which differ from SIG_DFL action
973 * (note: child (i.e., [v]forked) shell is not an interactive shell):
976 * SIGTERM (interactive): ignore
977 * SIGHUP (interactive):
978 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
979 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
980 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
981 * that all pipe members are stopped. Try this in bash:
982 * while :; do :; done - ^Z does not background it
983 * (while :; do :; done) - ^Z backgrounds it
984 * SIGINT (interactive): wait for last pipe, ignore the rest
985 * of the command line, show prompt. NB: ^C does not send SIGINT
986 * to interactive shell while shell is waiting for a pipe,
987 * since shell is bg'ed (is not in foreground process group).
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 SPECIAL_INTERACTIVE_SIGS = 0
1028 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
1031 //TODO | (1 << SIGHUP)
1035 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1037 // G.count_SIGCHLD++;
1040 static int check_and_run_traps(int sig)
1042 static const struct timespec zero_timespec = { 0, 0 };
1043 smalluint save_rcode;
1049 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1054 if (G.traps && G.traps[sig]) {
1055 if (G.traps[sig][0]) {
1056 /* We have user-defined handler */
1057 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1058 save_rcode = G.last_exitcode;
1061 G.last_exitcode = save_rcode;
1062 } /* else: "" trap, ignoring signal */
1065 /* not a trap: special action */
1068 // G.count_SIGCHLD++;
1071 //TODO: add putchar('\n') also when we detect that child was killed (sleep 5 + ^C)
1072 /* Builtin was ^C'ed, make it look prettier: */
1079 default: /* ignored: */
1080 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1089 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1090 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1091 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1092 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1094 /* Restores tty foreground process group, and exits.
1095 * May be called as signal handler for fatal signal
1096 * (will faithfully resend signal to itself, producing correct exit state)
1097 * or called directly with -EXITCODE.
1098 * We also call it if xfunc is exiting. */
1099 static void sigexit(int sig) NORETURN;
1100 static void sigexit(int sig)
1102 /* Disable all signals: job control, SIGPIPE, etc. */
1103 sigprocmask_allsigs(SIG_BLOCK);
1105 /* Careful: we can end up here after [v]fork. Do not restore
1106 * tty pgrp then, only top-level shell process does that */
1107 if (G_interactive_fd && getpid() == G.root_pid)
1108 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1110 /* Not a signal, just exit */
1114 kill_myself_with_sig(sig); /* does not return */
1118 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1119 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1123 /* Restores tty foreground process group, and exits. */
1124 static void hush_exit(int exitcode) NORETURN;
1125 static void hush_exit(int exitcode)
1127 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1128 /* Prevent recursion:
1129 * trap "echo Hi; exit" EXIT; exit
1131 char *argv[] = { NULL, G.traps[0], NULL };
1139 fflush(NULL); /* flush all streams */
1140 sigexit(- (exitcode & 0xff));
1147 static const char *set_cwd(void)
1149 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1150 * we must not try to free(bb_msg_unknown) */
1151 if (G.cwd == bb_msg_unknown)
1153 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1155 G.cwd = bb_msg_unknown;
1160 /* Get/check local shell variables */
1161 static struct variable *get_local_var(const char *name)
1163 struct variable *cur;
1169 for (cur = G.top_var; cur; cur = cur->next) {
1170 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1176 static const char *get_local_var_value(const char *src)
1178 struct variable *var = get_local_var(src);
1180 return strchr(var->varstr, '=') + 1;
1184 /* str holds "NAME=VAL" and is expected to be malloced.
1185 * We take ownership of it.
1189 * -1: if NAME is set, leave export status alone
1190 * if NAME is not set, do not export
1191 * flg_read_only is set only when we handle -R var=val
1194 #define set_local_var(str, flg_export, flg_read_only) \
1195 set_local_var(str, flg_export)
1197 static int set_local_var(char *str, int flg_export, int flg_read_only)
1199 struct variable *cur;
1203 value = strchr(str, '=');
1204 if (!value) { /* not expected to ever happen? */
1209 name_len = value - str + 1; /* including '=' */
1210 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1212 if (strncmp(cur->varstr, str, name_len) != 0) {
1214 /* Bail out. Note that now cur points
1215 * to last var in linked list */
1221 /* We found an existing var with this name */
1223 if (cur->flg_read_only) {
1227 bb_error_msg("%s: readonly variable", str);
1231 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1232 unsetenv(str); /* just in case */
1234 if (strcmp(cur->varstr, str) == 0) {
1239 if (cur->max_len >= strlen(str)) {
1240 /* This one is from startup env, reuse space */
1241 strcpy(cur->varstr, str);
1244 /* max_len == 0 signifies "malloced" var, which we can
1245 * (and has to) free */
1249 goto set_str_and_exp;
1252 /* Not found - create next variable struct */
1253 cur->next = xzalloc(sizeof(*cur));
1259 cur->flg_read_only = flg_read_only;
1262 if (flg_export == 1)
1263 cur->flg_export = 1;
1264 if (cur->flg_export) {
1265 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1266 return putenv(cur->varstr);
1271 static int unset_local_var(const char *name)
1273 struct variable *cur;
1274 struct variable *prev = prev; /* for gcc */
1278 return EXIT_SUCCESS;
1279 name_len = strlen(name);
1282 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1283 if (cur->flg_read_only) {
1284 bb_error_msg("%s: readonly variable", name);
1285 return EXIT_FAILURE;
1287 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1288 * is ro, and we cannot reach this code on the 1st pass */
1289 prev->next = cur->next;
1290 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1291 bb_unsetenv(cur->varstr);
1295 return EXIT_SUCCESS;
1300 return EXIT_SUCCESS;
1303 #if ENABLE_SH_MATH_SUPPORT
1304 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1305 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1306 static char *endofname(const char *name)
1314 if (!is_in_name(*p))
1320 static void arith_set_local_var(const char *name, const char *val, int flags)
1322 /* arith code doesnt malloc space, so do it for it */
1323 char *var = xasprintf("%s=%s", name, val);
1324 set_local_var(var, flags, 0);
1332 static int static_get(struct in_str *i)
1341 static int static_peek(struct in_str *i)
1346 #if ENABLE_HUSH_INTERACTIVE
1348 static void cmdedit_set_initial_prompt(void)
1350 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1351 G.PS1 = getenv("PS1");
1358 static const char* setup_prompt_string(int promptmode)
1360 const char *prompt_str;
1361 debug_printf("setup_prompt_string %d ", promptmode);
1362 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1363 /* Set up the prompt */
1364 if (promptmode == 0) { /* PS1 */
1366 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1371 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1372 debug_printf("result '%s'\n", prompt_str);
1376 static void get_user_input(struct in_str *i)
1379 const char *prompt_str;
1381 prompt_str = setup_prompt_string(i->promptmode);
1382 #if ENABLE_FEATURE_EDITING
1383 /* Enable command line editing only while a command line
1384 * is actually being read */
1387 /* buglet: SIGINT will not make new prompt to appear _at once_,
1388 * only after <Enter>. (^C will work) */
1389 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1390 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1391 check_and_run_traps(0);
1392 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1393 i->eof_flag = (r < 0);
1394 if (i->eof_flag) { /* EOF/error detected */
1395 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1396 G.user_input_buf[1] = '\0';
1401 fputs(prompt_str, stdout);
1403 G.user_input_buf[0] = r = fgetc(i->file);
1404 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1405 //do we need check_and_run_traps(0)? (maybe only if stdin)
1406 } while (G.flag_SIGINT);
1407 i->eof_flag = (r == EOF);
1409 i->p = G.user_input_buf;
1412 #endif /* INTERACTIVE */
1414 /* This is the magic location that prints prompts
1415 * and gets data back from the user */
1416 static int file_get(struct in_str *i)
1420 /* If there is data waiting, eat it up */
1421 if (i->p && *i->p) {
1422 #if ENABLE_HUSH_INTERACTIVE
1426 if (i->eof_flag && !*i->p)
1428 /* note: ch is never NUL */
1430 /* need to double check i->file because we might be doing something
1431 * more complicated by now, like sourcing or substituting. */
1432 #if ENABLE_HUSH_INTERACTIVE
1433 if (G_interactive_fd && i->promptme && i->file == stdin) {
1436 } while (!*i->p); /* need non-empty line */
1437 i->promptmode = 1; /* PS2 */
1442 do ch = fgetc(i->file); while (ch == '\0');
1444 debug_printf("file_get: got '%c' %d\n", ch, ch);
1445 #if ENABLE_HUSH_INTERACTIVE
1452 /* All callers guarantee this routine will never
1453 * be used right after a newline, so prompting is not needed.
1455 static int file_peek(struct in_str *i)
1458 if (i->p && *i->p) {
1459 if (i->eof_flag && !i->p[1])
1462 /* note: ch is never NUL */
1464 do ch = fgetc(i->file); while (ch == '\0');
1465 i->eof_flag = (ch == EOF);
1466 i->peek_buf[0] = ch;
1467 i->peek_buf[1] = '\0';
1469 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1473 static void setup_file_in_str(struct in_str *i, FILE *f)
1475 i->peek = file_peek;
1477 #if ENABLE_HUSH_INTERACTIVE
1479 i->promptmode = 0; /* PS1 */
1485 static void setup_string_in_str(struct in_str *i, const char *s)
1487 i->peek = static_peek;
1488 i->get = static_get;
1489 #if ENABLE_HUSH_INTERACTIVE
1491 i->promptmode = 0; /* PS1 */
1501 #define B_CHUNK (32 * sizeof(char*))
1503 static void o_reset_to_empty_unquoted(o_string *o)
1511 static void o_free(o_string *o)
1514 memset(o, 0, sizeof(*o));
1517 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1522 static void o_grow_by(o_string *o, int len)
1524 if (o->length + len > o->maxlen) {
1525 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1526 o->data = xrealloc(o->data, 1 + o->maxlen);
1530 static void o_addchr(o_string *o, int ch)
1532 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1534 o->data[o->length] = ch;
1536 o->data[o->length] = '\0';
1539 static void o_addblock(o_string *o, const char *str, int len)
1542 memcpy(&o->data[o->length], str, len);
1544 o->data[o->length] = '\0';
1548 static void o_addstr(o_string *o, const char *str)
1550 o_addblock(o, str, strlen(str));
1552 static void nommu_addchr(o_string *o, int ch)
1558 #define nommu_addchr(o, str) ((void)0)
1561 static void o_addstr_with_NUL(o_string *o, const char *str)
1563 o_addblock(o, str, strlen(str) + 1);
1566 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1571 && (*str != '*' && *str != '?' && *str != '[')
1579 /* My analysis of quoting semantics tells me that state information
1580 * is associated with a destination, not a source.
1582 static void o_addqchr(o_string *o, int ch)
1585 char *found = strchr("*?[\\", ch);
1590 o->data[o->length] = '\\';
1593 o->data[o->length] = ch;
1595 o->data[o->length] = '\0';
1598 static void o_addQchr(o_string *o, int ch)
1601 if (o->o_escape && strchr("*?[\\", ch)) {
1603 o->data[o->length] = '\\';
1607 o->data[o->length] = ch;
1609 o->data[o->length] = '\0';
1612 static void o_addQstr(o_string *o, const char *str, int len)
1615 o_addblock(o, str, len);
1621 int ordinary_cnt = strcspn(str, "*?[\\");
1622 if (ordinary_cnt > len) /* paranoia */
1624 o_addblock(o, str, ordinary_cnt);
1625 if (ordinary_cnt == len)
1627 str += ordinary_cnt;
1628 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1632 if (ch) { /* it is necessarily one of "*?[\\" */
1634 o->data[o->length] = '\\';
1638 o->data[o->length] = ch;
1640 o->data[o->length] = '\0';
1644 /* A special kind of o_string for $VAR and `cmd` expansion.
1645 * It contains char* list[] at the beginning, which is grown in 16 element
1646 * increments. Actual string data starts at the next multiple of 16 * (char*).
1647 * list[i] contains an INDEX (int!) into this string data.
1648 * It means that if list[] needs to grow, data needs to be moved higher up
1649 * but list[i]'s need not be modified.
1650 * NB: remembering how many list[i]'s you have there is crucial.
1651 * o_finalize_list() operation post-processes this structure - calculates
1652 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1654 #if DEBUG_EXPAND || DEBUG_GLOB
1655 static void debug_print_list(const char *prefix, o_string *o, int n)
1657 char **list = (char**)o->data;
1658 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1662 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1663 prefix, list, n, string_start, o->length, o->maxlen);
1666 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1667 o->data + (int)list[i] + string_start,
1668 o->data + (int)list[i] + string_start);
1672 const char *p = o->data + (int)list[n - 1] + string_start;
1674 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1678 #define debug_print_list(prefix, o, n) ((void)0)
1681 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1682 * in list[n] so that it points past last stored byte so far.
1683 * It returns n+1. */
1684 static int o_save_ptr_helper(o_string *o, int n)
1686 char **list = (char**)o->data;
1690 if (!o->has_empty_slot) {
1691 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1692 string_len = o->length - string_start;
1693 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1694 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1695 /* list[n] points to string_start, make space for 16 more pointers */
1696 o->maxlen += 0x10 * sizeof(list[0]);
1697 o->data = xrealloc(o->data, o->maxlen + 1);
1698 list = (char**)o->data;
1699 memmove(list + n + 0x10, list + n, string_len);
1700 o->length += 0x10 * sizeof(list[0]);
1702 debug_printf_list("list[%d]=%d string_start=%d\n",
1703 n, string_len, string_start);
1706 /* We have empty slot at list[n], reuse without growth */
1707 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1708 string_len = o->length - string_start;
1709 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1710 n, string_len, string_start);
1711 o->has_empty_slot = 0;
1713 list[n] = (char*)(ptrdiff_t)string_len;
1717 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1718 static int o_get_last_ptr(o_string *o, int n)
1720 char **list = (char**)o->data;
1721 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1723 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1726 /* o_glob performs globbing on last list[], saving each result
1727 * as a new list[]. */
1728 static int o_glob(o_string *o, int n)
1734 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1736 return o_save_ptr_helper(o, n);
1737 pattern = o->data + o_get_last_ptr(o, n);
1738 debug_printf_glob("glob pattern '%s'\n", pattern);
1739 if (!glob_needed(pattern)) {
1741 o->length = unbackslash(pattern) - o->data;
1742 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1743 return o_save_ptr_helper(o, n);
1746 memset(&globdata, 0, sizeof(globdata));
1747 gr = glob(pattern, 0, NULL, &globdata);
1748 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1749 if (gr == GLOB_NOSPACE)
1750 bb_error_msg_and_die("out of memory during glob");
1751 if (gr == GLOB_NOMATCH) {
1752 globfree(&globdata);
1755 if (gr != 0) { /* GLOB_ABORTED ? */
1756 //TODO: testcase for bad glob pattern behavior
1757 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1759 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1760 char **argv = globdata.gl_pathv;
1761 o->length = pattern - o->data; /* "forget" pattern */
1763 o_addstr_with_NUL(o, *argv);
1764 n = o_save_ptr_helper(o, n);
1770 globfree(&globdata);
1772 debug_print_list("o_glob returning", o, n);
1776 /* If o->o_glob == 1, glob the string so far remembered.
1777 * Otherwise, just finish current list[] and start new */
1778 static int o_save_ptr(o_string *o, int n)
1780 if (o->o_glob) { /* if globbing is requested */
1781 /* If o->has_empty_slot, list[n] was already globbed
1782 * (if it was requested back then when it was filled)
1783 * so don't do that again! */
1784 if (!o->has_empty_slot)
1785 return o_glob(o, n); /* o_save_ptr_helper is inside */
1787 return o_save_ptr_helper(o, n);
1790 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1791 static char **o_finalize_list(o_string *o, int n)
1796 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1798 debug_print_list("finalized", o, n);
1799 debug_printf_expand("finalized n:%d\n", n);
1800 list = (char**)o->data;
1801 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1805 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1811 /* Expansion can recurse */
1812 #if ENABLE_HUSH_TICK
1813 static int process_command_subs(o_string *dest, const char *s);
1815 static char *expand_string_to_string(const char *str);
1817 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1818 parse_stream_dquoted(dest, input, dquote_end)
1820 static int parse_stream_dquoted(o_string *as_string,
1822 struct in_str *input,
1825 /* expand_strvec_to_strvec() takes a list of strings, expands
1826 * all variable references within and returns a pointer to
1827 * a list of expanded strings, possibly with larger number
1828 * of strings. (Think VAR="a b"; echo $VAR).
1829 * This new list is allocated as a single malloc block.
1830 * NULL-terminated list of char* pointers is at the beginning of it,
1831 * followed by strings themself.
1832 * Caller can deallocate entire list by single free(list). */
1834 /* Store given string, finalizing the word and starting new one whenever
1835 * we encounter IFS char(s). This is used for expanding variable values.
1836 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1837 static int expand_on_ifs(o_string *output, int n, const char *str)
1840 int word_len = strcspn(str, G.ifs);
1842 if (output->o_escape || !output->o_glob)
1843 o_addQstr(output, str, word_len);
1844 else /* protect backslashes against globbing up :) */
1845 o_addblock_duplicate_backslash(output, str, word_len);
1848 if (!*str) /* EOL - do not finalize word */
1850 o_addchr(output, '\0');
1851 debug_print_list("expand_on_ifs", output, n);
1852 n = o_save_ptr(output, n);
1853 str += strspn(str, G.ifs); /* skip ifs chars */
1855 debug_print_list("expand_on_ifs[1]", output, n);
1859 /* Helper to expand $((...)) and heredoc body. These act as if
1860 * they are in double quotes, with the exception that they are not :).
1861 * Just the rules are similar: "expand only $var and `cmd`"
1863 * Returns malloced string.
1864 * As an optimization, we return NULL if expansion is not needed.
1866 static char *expand_pseudo_dquoted(const char *str)
1869 struct in_str input;
1870 o_string dest = NULL_O_STRING;
1872 if (strchr(str, '$') == NULL
1873 #if ENABLE_HUSH_TICK
1874 && strchr(str, '`') == NULL
1880 /* We need to expand. Example:
1881 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1883 setup_string_in_str(&input, str);
1884 parse_stream_dquoted(NULL, &dest, &input, EOF);
1885 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1886 exp_str = expand_string_to_string(dest.data);
1887 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1888 o_free_unsafe(&dest);
1892 /* Expand all variable references in given string, adding words to list[]
1893 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1894 * to be filled). This routine is extremely tricky: has to deal with
1895 * variables/parameters with whitespace, $* and $@, and constructs like
1896 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1897 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1899 /* or_mask is either 0 (normal case) or 0x80
1900 * (expansion of right-hand side of assignment == 1-element expand.
1901 * It will also do no globbing, and thus we must not backslash-quote!) */
1903 char first_ch, ored_ch;
1911 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1912 debug_print_list("expand_vars_to_list", output, n);
1913 n = o_save_ptr(output, n);
1914 debug_print_list("expand_vars_to_list[0]", output, n);
1916 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1917 #if ENABLE_HUSH_TICK
1918 o_string subst_result = NULL_O_STRING;
1920 #if ENABLE_SH_MATH_SUPPORT
1921 char arith_buf[sizeof(arith_t)*3 + 2];
1923 o_addblock(output, arg, p - arg);
1924 debug_print_list("expand_vars_to_list[1]", output, n);
1926 p = strchr(p, SPECIAL_VAR_SYMBOL);
1928 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1929 /* "$@" is special. Even if quoted, it can still
1930 * expand to nothing (not even an empty string) */
1931 if ((first_ch & 0x7f) != '@')
1932 ored_ch |= first_ch;
1935 switch (first_ch & 0x7f) {
1936 /* Highest bit in first_ch indicates that var is double-quoted */
1938 val = utoa(G.root_pid);
1940 case '!': /* bg pid */
1941 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1943 case '?': /* exitcode */
1944 val = utoa(G.last_exitcode);
1946 case '#': /* argc */
1947 if (arg[1] != SPECIAL_VAR_SYMBOL)
1948 /* actually, it's a ${#var} */
1950 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1955 if (!G.global_argv[i])
1957 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1958 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1959 smallint sv = output->o_escape;
1960 /* unquoted var's contents should be globbed, so don't escape */
1961 output->o_escape = 0;
1962 while (G.global_argv[i]) {
1963 n = expand_on_ifs(output, n, G.global_argv[i]);
1964 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1965 if (G.global_argv[i++][0] && G.global_argv[i]) {
1966 /* this argv[] is not empty and not last:
1967 * put terminating NUL, start new word */
1968 o_addchr(output, '\0');
1969 debug_print_list("expand_vars_to_list[2]", output, n);
1970 n = o_save_ptr(output, n);
1971 debug_print_list("expand_vars_to_list[3]", output, n);
1974 output->o_escape = sv;
1976 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1977 * and in this case should treat it like '$*' - see 'else...' below */
1978 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1980 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1981 if (++i >= G.global_argc)
1983 o_addchr(output, '\0');
1984 debug_print_list("expand_vars_to_list[4]", output, n);
1985 n = o_save_ptr(output, n);
1987 } else { /* quoted $*: add as one word */
1989 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1990 if (!G.global_argv[++i])
1993 o_addchr(output, G.ifs[0]);
1997 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1998 /* "Empty variable", used to make "" etc to not disappear */
2002 #if ENABLE_HUSH_TICK
2003 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2006 //TODO: can we just stuff it into "output" directly?
2007 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2008 process_command_subs(&subst_result, arg);
2009 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2010 val = subst_result.data;
2013 #if ENABLE_SH_MATH_SUPPORT
2014 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2015 arith_eval_hooks_t hooks;
2020 arg++; /* skip '+' */
2021 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2022 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2024 exp_str = expand_pseudo_dquoted(arg);
2025 hooks.lookupvar = get_local_var_value;
2026 hooks.setvar = arith_set_local_var;
2027 hooks.endofname = endofname;
2028 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2032 const char *msg = "error in arithmetic";
2035 msg = "exponent less than 0";
2038 msg = "divide by 0";
2041 msg = "expression recursion loop detected";
2046 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2047 sprintf(arith_buf, arith_t_fmt, res);
2052 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2054 bool exp_len = false;
2055 bool exp_null = false;
2057 char exp_save = exp_save; /* for compiler */
2058 char exp_op = exp_op; /* for compiler */
2059 char *exp_word = exp_word; /* for compiler */
2063 arg[0] = first_ch & 0x7f;
2065 /* prepare for expansions */
2066 if (var[0] == '#') {
2067 /* handle length expansion ${#var} */
2071 /* maybe handle parameter expansion */
2072 exp_off = strcspn(var, ":-=+?%#");
2076 exp_save = var[exp_off];
2077 exp_null = exp_save == ':';
2078 exp_word = var + exp_off;
2081 exp_op = *exp_word++;
2082 var[exp_off] = '\0';
2086 /* lookup the variable in question */
2087 if (isdigit(var[0])) {
2088 /* handle_dollar() should have vetted var for us */
2090 if (i < G.global_argc)
2091 val = G.global_argv[i];
2092 /* else val remains NULL: $N with too big N */
2094 val = get_local_var_value(var);
2096 /* handle any expansions */
2098 debug_printf_expand("expand: length of '%s' = ", val);
2099 val = utoa(val ? strlen(val) : 0);
2100 debug_printf_expand("%s\n", val);
2101 } else if (exp_off) {
2102 if (exp_op == '%' || exp_op == '#') {
2104 /* we need to do a pattern match */
2107 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2108 if (exp_op == *exp_word) /* ## or %% */
2110 val = dyn_val = xstrdup(val);
2111 loc = scan(dyn_val, exp_word, zero);
2118 /* we need to do an expansion */
2119 int exp_test = (!val || (exp_null && !val[0]));
2121 exp_test = !exp_test;
2122 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2123 exp_null ? "true" : "false", exp_test);
2125 if (exp_op == '?') {
2126 //TODO: how interactive bash aborts expansion mid-command?
2127 /* ${var?[error_msg_if_unset]} */
2128 /* ${var:?[error_msg_if_unset_or_null]} */
2129 /* mimic bash message */
2130 die_if_script("%s: %s",
2132 exp_word[0] ? exp_word : "parameter null or not set"
2138 if (exp_op == '=') {
2139 /* ${var=[word]} or ${var:=[word]} */
2140 if (isdigit(var[0]) || var[0] == '#') {
2141 /* mimic bash message */
2142 die_if_script("$%s: cannot assign in this way", var);
2145 char *new_var = xasprintf("%s=%s", var, val);
2146 set_local_var(new_var, -1, 0);
2152 var[exp_off] = exp_save;
2156 #if ENABLE_HUSH_TICK
2159 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2160 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2162 /* unquoted var's contents should be globbed, so don't escape */
2163 smallint sv = output->o_escape;
2164 output->o_escape = 0;
2165 n = expand_on_ifs(output, n, val);
2167 output->o_escape = sv;
2169 } else { /* quoted $VAR, val will be appended below */
2170 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2173 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2175 o_addQstr(output, val, strlen(val));
2179 /* Do the check to avoid writing to a const string */
2180 if (*p != SPECIAL_VAR_SYMBOL)
2181 *p = SPECIAL_VAR_SYMBOL;
2183 #if ENABLE_HUSH_TICK
2184 o_free(&subst_result);
2187 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2190 debug_print_list("expand_vars_to_list[a]", output, n);
2191 /* this part is literal, and it was already pre-quoted
2192 * if needed (much earlier), do not use o_addQstr here! */
2193 o_addstr_with_NUL(output, arg);
2194 debug_print_list("expand_vars_to_list[b]", output, n);
2195 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2196 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2199 /* allow to reuse list[n] later without re-growth */
2200 output->has_empty_slot = 1;
2202 o_addchr(output, '\0');
2207 static char **expand_variables(char **argv, int or_mask)
2212 o_string output = NULL_O_STRING;
2214 if (or_mask & 0x100) {
2215 output.o_escape = 1; /* protect against globbing for "$var" */
2216 /* (unquoted $var will temporarily switch it off) */
2223 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2226 debug_print_list("expand_variables", &output, n);
2228 /* output.data (malloced in one block) gets returned in "list" */
2229 list = o_finalize_list(&output, n);
2230 debug_print_strings("expand_variables[1]", list);
2234 static char **expand_strvec_to_strvec(char **argv)
2236 return expand_variables(argv, 0x100);
2239 /* Used for expansion of right hand of assignments */
2240 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2242 static char *expand_string_to_string(const char *str)
2244 char *argv[2], **list;
2246 argv[0] = (char*)str;
2248 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2250 if (!list[0] || list[1])
2251 bb_error_msg_and_die("BUG in varexp2");
2252 /* actually, just move string 2*sizeof(char*) bytes back */
2253 overlapping_strcpy((char*)list, list[0]);
2254 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2258 /* Used for "eval" builtin */
2259 static char* expand_strvec_to_string(char **argv)
2263 list = expand_variables(argv, 0x80);
2264 /* Convert all NULs to spaces */
2269 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2270 bb_error_msg_and_die("BUG in varexp3");
2271 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2275 overlapping_strcpy((char*)list, list[0]);
2276 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2280 static char **expand_assignments(char **argv, int count)
2284 /* Expand assignments into one string each */
2285 for (i = 0; i < count; i++) {
2286 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2294 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2296 static void reset_traps_to_defaults(void)
2298 /* This function is always called in a child shell
2299 * after fork (not vfork, NOMMU doesn't use this function).
2300 * Child shells are not interactive.
2301 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2302 * Testcase: (while :; do :; done) + ^Z should background.
2303 * Same goes for SIGTERM, SIGHUP, SIGINT.
2308 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2311 /* Stupid. It can be done with *single* &= op, but we can't use
2312 * the fact that G.blocked_set is implemented as a bitmask... */
2313 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2317 sigdelset(&G.blocked_set, sig);
2324 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2325 mask = G.non_DFL_mask;
2326 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2330 G.traps[sig] = NULL;
2331 /* There is no signal for 0 (EXIT) */
2334 /* There was a trap handler, we are removing it.
2335 * But if sig still has non-DFL handling,
2336 * we should not unblock it. */
2339 sigdelset(&G.blocked_set, sig);
2341 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2346 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2347 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2349 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2350 char *heredoc_argv[4];
2351 struct variable *cur;
2352 #if ENABLE_HUSH_FUNCTIONS
2353 struct function *funcp;
2358 if (!g_argv0) { /* heredoc */
2359 argv = heredoc_argv;
2360 argv[0] = (char *) G.argv0_for_re_execing;
2361 argv[1] = (char *) "-<";
2362 argv[2] = (char *) s;
2364 pp = &argv[3]; /* used as pointer to empty environment */
2368 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2369 , (unsigned) G.root_pid
2370 , (unsigned) G.last_bg_pid
2371 , (unsigned) G.last_exitcode
2372 USE_HUSH_LOOPS(, G.depth_of_loop)
2374 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2375 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2378 for (cur = G.top_var; cur; cur = cur->next) {
2379 if (!cur->flg_export || cur->flg_read_only)
2382 #if ENABLE_HUSH_FUNCTIONS
2383 for (funcp = G.top_func; funcp; funcp = funcp->next)
2389 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2390 *pp++ = (char *) G.argv0_for_re_execing;
2392 for (cur = G.top_var; cur; cur = cur->next) {
2393 if (cur->varstr == hush_version_str)
2395 if (cur->flg_read_only) {
2396 *pp++ = (char *) "-R";
2397 *pp++ = cur->varstr;
2398 } else if (!cur->flg_export) {
2399 *pp++ = (char *) "-V";
2400 *pp++ = cur->varstr;
2403 #if ENABLE_HUSH_FUNCTIONS
2404 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2405 *pp++ = (char *) "-F";
2406 *pp++ = funcp->name;
2407 *pp++ = funcp->body_as_string;
2410 /* We can pass activated traps here. Say, -Tnn:trap_string
2412 * However, POSIX says that subshells reset signals with traps
2414 * I tested bash-3.2 and it not only does that with true subshells
2415 * of the form ( list ), but with any forked children shells.
2416 * I set trap "echo W" WINCH; and then tried:
2418 * { echo 1; sleep 20; echo 2; } &
2419 * while true; do echo 1; sleep 20; echo 2; break; done &
2420 * true | { echo 1; sleep 20; echo 2; } | cat
2422 * In all these cases sending SIGWINCH to the child shell
2423 * did not run the trap. If I add trap "echo V" WINCH;
2424 * _inside_ group (just before echo 1), it works.
2426 * I conclude it means we don't need to pass active traps here.
2427 * exec syscall below resets them to SIG_DFL for us.
2429 *pp++ = (char *) "-c";
2434 /* *pp = NULL; - is already there */
2438 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2439 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2440 execve(bb_busybox_exec_path, argv, pp);
2441 /* Fallback. Useful for init=/bin/hush usage etc */
2442 if (argv[0][0] == '/')
2443 execve(argv[0], argv, pp);
2444 xfunc_error_retval = 127;
2445 bb_error_msg_and_die("can't re-execute the shell");
2447 #endif /* !BB_MMU */
2450 static void setup_heredoc(struct redir_struct *redir)
2452 struct fd_pair pair;
2455 /* the _body_ of heredoc (misleading field name) */
2456 const char *heredoc = redir->rd_filename;
2463 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2464 expanded = expand_pseudo_dquoted(heredoc);
2468 len = strlen(heredoc);
2470 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2472 xmove_fd(pair.rd, redir->rd_fd);
2474 /* Try writing without forking. Newer kernels have
2475 * dynamically growing pipes. Must use non-blocking write! */
2478 written = write(pair.wr, heredoc, len);
2489 ndelay_off(pair.wr);
2491 /* Okay, pipe buffer was not big enough */
2492 /* Note: we must not create a stray child (bastard? :)
2493 * for the unsuspecting parent process. Child creates a grandchild
2494 * and exits before parent execs the process which consumes heredoc
2495 * (that exec happens after we return from this function) */
2501 bb_perror_msg_and_die("vfork");
2504 disable_restore_tty_pgrp_on_exit();
2505 pid = BB_MMU ? fork() : vfork();
2507 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2511 close(redir->rd_fd); /* read side of the pipe */
2513 full_write(pair.wr, heredoc, len); /* may loop or block */
2516 /* Delegate blocking writes to another process */
2517 xmove_fd(pair.wr, STDOUT_FILENO);
2518 re_execute_shell(&to_free, heredoc, NULL, NULL);
2522 enable_restore_tty_pgrp_on_exit();
2528 wait(NULL); /* wait till child has died */
2531 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2532 * and stderr if they are redirected. */
2533 static int setup_redirects(struct command *prog, int squirrel[])
2536 struct redir_struct *redir;
2538 for (redir = prog->redirects; redir; redir = redir->next) {
2539 if (redir->rd_type == REDIRECT_HEREDOC2) {
2540 /* rd_fd<<HERE case */
2541 if (squirrel && redir->rd_fd < 3) {
2542 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2544 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2546 debug_printf_parse("set heredoc '%s'\n",
2547 redir->rd_filename);
2548 setup_heredoc(redir);
2552 if (redir->rd_dup == REDIRFD_TO_FILE) {
2553 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2555 if (redir->rd_filename == NULL) {
2556 /* Something went wrong in the parse.
2557 * Pretend it didn't happen */
2558 bb_error_msg("bug in redirect parse");
2561 mode = redir_table[redir->rd_type].mode;
2562 p = expand_string_to_string(redir->rd_filename);
2563 openfd = open_or_warn(p, mode);
2566 /* this could get lost if stderr has been redirected, but
2567 * bash and ash both lose it as well (though zsh doesn't!) */
2568 //what the above comment tries to say?
2572 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2573 openfd = redir->rd_dup;
2576 if (openfd != redir->rd_fd) {
2577 if (squirrel && redir->rd_fd < 3) {
2578 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2580 if (openfd == REDIRFD_CLOSE) {
2581 /* "n>-" means "close me" */
2582 close(redir->rd_fd);
2584 xdup2(openfd, redir->rd_fd);
2585 if (redir->rd_dup == REDIRFD_TO_FILE)
2593 static void restore_redirects(int squirrel[])
2596 for (i = 0; i < 3; i++) {
2599 /* We simply die on error */
2606 static void free_pipe_list(struct pipe *head);
2608 /* Return code is the exit status of the pipe */
2609 static void free_pipe(struct pipe *pi)
2612 struct command *command;
2613 struct redir_struct *r, *rnext;
2616 if (pi->stopped_cmds > 0) /* why? */
2618 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2619 for (i = 0; i < pi->num_cmds; i++) {
2620 command = &pi->cmds[i];
2621 debug_printf_clean(" command %d:\n", i);
2622 if (command->argv) {
2623 for (a = 0, p = command->argv; *p; a++, p++) {
2624 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2626 free_strings(command->argv);
2627 command->argv = NULL;
2629 /* not "else if": on syntax error, we may have both! */
2630 if (command->group) {
2631 debug_printf_clean(" begin group (grp_type:%d)\n",
2633 free_pipe_list(command->group);
2634 debug_printf_clean(" end group\n");
2635 command->group = NULL;
2637 /* else is crucial here.
2638 * If group != NULL, child_func is meaningless */
2639 #if ENABLE_HUSH_FUNCTIONS
2640 else if (command->child_func) {
2641 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2642 command->child_func->parent_cmd = NULL;
2646 free(command->group_as_string);
2647 command->group_as_string = NULL;
2649 for (r = command->redirects; r; r = rnext) {
2650 debug_printf_clean(" redirect %d%s",
2651 r->rd_fd, redir_table[r->rd_type].descrip);
2652 /* guard against the case >$FOO, where foo is unset or blank */
2653 if (r->rd_filename) {
2654 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2655 free(r->rd_filename);
2656 r->rd_filename = NULL;
2658 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2662 command->redirects = NULL;
2664 free(pi->cmds); /* children are an array, they get freed all at once */
2672 static void free_pipe_list(struct pipe *head)
2674 struct pipe *pi, *next;
2676 for (pi = head; pi; pi = next) {
2678 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2681 debug_printf_clean("pipe followup code %d\n", pi->followup);
2683 /*pi->next = NULL;*/
2689 static int run_list(struct pipe *pi);
2691 #define parse_stream(pstring, input, end_trigger) \
2692 parse_stream(input, end_trigger)
2694 static struct pipe *parse_stream(char **pstring,
2695 struct in_str *input,
2697 static void parse_and_run_string(const char *s);
2700 static const struct built_in_command* find_builtin(const char *name)
2702 const struct built_in_command *x;
2703 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2704 if (strcmp(name, x->cmd) != 0)
2706 debug_printf_exec("found builtin '%s'\n", name);
2712 #if ENABLE_HUSH_FUNCTIONS
2713 static const struct function *find_function(const char *name)
2715 const struct function *funcp = G.top_func;
2717 if (strcmp(name, funcp->name) == 0) {
2720 funcp = funcp->next;
2722 debug_printf_exec("found function '%s'\n", name);
2726 /* Note: takes ownership on name ptr */
2727 static struct function *new_function(char *name)
2729 struct function *funcp;
2730 struct function **funcpp = &G.top_func;
2732 while ((funcp = *funcpp) != NULL) {
2733 struct command *cmd;
2735 if (strcmp(funcp->name, name) != 0) {
2736 funcpp = &funcp->next;
2740 cmd = funcp->parent_cmd;
2741 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2743 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2745 /* Note: if !funcp->body, do not free body_as_string!
2746 * This is a special case of "-F name body" function:
2747 * body_as_string was not malloced! */
2749 free_pipe_list(funcp->body);
2751 free(funcp->body_as_string);
2755 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2756 cmd->argv[0] = funcp->name;
2757 cmd->group = funcp->body;
2759 cmd->group_as_string = funcp->body_as_string;
2764 debug_printf_exec("remembering new function '%s'\n", command->argv[0]);
2765 funcp = *funcpp = xzalloc(sizeof(*funcp));
2766 /*funcp->next = NULL;*/
2773 #define exec_function(nommu_save, funcp, argv) \
2774 exec_function(funcp, argv)
2776 static void exec_function(nommu_save_t *nommu_save,
2777 const struct function *funcp,
2778 char **argv) NORETURN;
2779 static void exec_function(nommu_save_t *nommu_save,
2780 const struct function *funcp,
2786 argv[0] = G.global_argv[0];
2787 G.global_argv = argv;
2791 /* On MMU, funcp->body is always non-NULL */
2792 n = run_list(funcp->body);
2796 re_execute_shell(&nommu_save->argv_from_re_execing,
2797 funcp->body_as_string,
2803 static int run_function(const struct function *funcp, char **argv)
2808 smallint sv_g_malloced;
2813 sv_g_malloced = G.global_args_malloced;
2814 sv_g_argc = G.global_argc;
2815 sv_g_argv = G.global_argv;
2822 argv[0] = G.global_argv[0]; /* retain $0 */
2823 G.global_args_malloced = 0;
2825 G.global_argv = argv;
2827 /* On MMU, funcp->body is always non-NULL */
2830 /* Function defined by -F */
2831 parse_and_run_string(funcp->body_as_string);
2832 n = G.last_exitcode;
2836 n = run_list(funcp->body);
2839 if (G.global_args_malloced) {
2840 /* function ran "set -- arg1 arg2 ..." */
2844 free(G.global_argv);
2848 G.global_args_malloced = sv_g_malloced;
2849 G.global_argc = sv_g_argc;
2850 G.global_argv = sv_g_argv;
2858 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2859 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2860 #define pseudo_exec(nommu_save, command, argv_expanded) \
2861 pseudo_exec(command, argv_expanded)
2864 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2866 * XXX no exit() here. If you don't exec, use _exit instead.
2867 * The at_exit handlers apparently confuse the calling process,
2868 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2869 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2870 char **argv, int assignment_cnt,
2871 char **argv_expanded) NORETURN;
2872 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2873 char **argv, int assignment_cnt,
2874 char **argv_expanded)
2878 /* Case when we are here: ... | var=val | ... */
2879 if (!argv[assignment_cnt])
2880 _exit(EXIT_SUCCESS);
2882 new_env = expand_assignments(argv, assignment_cnt);
2884 putenv_all(new_env);
2885 free(new_env); /* optional */
2887 nommu_save->new_env = new_env;
2888 nommu_save->old_env = putenv_all_and_save_old(new_env);
2890 if (argv_expanded) {
2891 argv = argv_expanded;
2893 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2895 nommu_save->argv = argv;
2899 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2900 if (strchr(argv[0], '/') != NULL)
2904 /* On NOMMU, we must never block!
2905 * Example: { sleep 99999 | read line } & echo Ok
2906 * read builtin will block on read syscall, leaving parent blocked
2907 * in vfork. Therefore we can't do this:
2910 /* Check if the command matches any of the builtins.
2911 * Depending on context, this might be redundant. But it's
2912 * easier to waste a few CPU cycles than it is to figure out
2913 * if this is one of those cases.
2917 const struct built_in_command *x = find_builtin(argv[0]);
2919 rcode = x->function(argv);
2925 #if ENABLE_HUSH_FUNCTIONS
2926 /* Check if the command matches any functions */
2928 const struct function *funcp = find_function(argv[0]);
2930 exec_function(nommu_save, funcp, argv);
2935 #if ENABLE_FEATURE_SH_STANDALONE
2936 /* Check if the command matches any busybox applets */
2938 int a = find_applet_by_name(argv[0]);
2940 # if BB_MMU /* see above why on NOMMU it is not allowed */
2941 if (APPLET_IS_NOEXEC(a)) {
2942 debug_printf_exec("running applet '%s'\n", argv[0]);
2943 run_applet_no_and_exit(a, argv);
2946 /* Re-exec ourselves */
2947 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2948 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2949 execv(bb_busybox_exec_path, argv);
2950 /* If they called chroot or otherwise made the binary no longer
2951 * executable, fall through */
2956 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2959 debug_printf_exec("execing '%s'\n", argv[0]);
2960 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2961 execvp(argv[0], argv);
2962 bb_perror_msg("can't exec '%s'", argv[0]);
2963 _exit(EXIT_FAILURE);
2966 /* Called after [v]fork() in run_pipe
2968 static void pseudo_exec(nommu_save_t *nommu_save,
2969 struct command *command,
2970 char **argv_expanded) NORETURN;
2971 static void pseudo_exec(nommu_save_t *nommu_save,
2972 struct command *command,
2973 char **argv_expanded)
2975 if (command->argv) {
2976 pseudo_exec_argv(nommu_save, command->argv,
2977 command->assignment_cnt, argv_expanded);
2980 if (command->group) {
2981 /* Cases when we are here:
2984 * ... | ( list ) | ...
2985 * ... | { list } | ...
2989 debug_printf_exec("pseudo_exec: run_list\n");
2990 reset_traps_to_defaults();
2991 rcode = run_list(command->group);
2992 /* OK to leak memory by not calling free_pipe_list,
2993 * since this process is about to exit */
2996 re_execute_shell(&nommu_save->argv_from_re_execing,
2997 command->group_as_string,
3003 /* Case when we are here: ... | >file */
3004 debug_printf_exec("pseudo_exec'ed null command\n");
3005 _exit(EXIT_SUCCESS);
3009 static const char *get_cmdtext(struct pipe *pi)
3015 /* This is subtle. ->cmdtext is created only on first backgrounding.
3016 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3017 * On subsequent bg argv is trashed, but we won't use it */
3020 argv = pi->cmds[0].argv;
3021 if (!argv || !argv[0]) {
3022 pi->cmdtext = xzalloc(1);
3027 do len += strlen(*argv) + 1; while (*++argv);
3028 pi->cmdtext = p = xmalloc(len);
3029 argv = pi->cmds[0].argv;
3031 len = strlen(*argv);
3032 memcpy(p, *argv, len);
3040 static void insert_bg_job(struct pipe *pi)
3042 struct pipe *thejob;
3045 /* Linear search for the ID of the job to use */
3047 for (thejob = G.job_list; thejob; thejob = thejob->next)
3048 if (thejob->jobid >= pi->jobid)
3049 pi->jobid = thejob->jobid + 1;
3051 /* Add thejob to the list of running jobs */
3053 thejob = G.job_list = xmalloc(sizeof(*thejob));
3055 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
3057 thejob->next = xmalloc(sizeof(*thejob));
3058 thejob = thejob->next;
3061 /* Physically copy the struct job */
3062 memcpy(thejob, pi, sizeof(struct pipe));
3063 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3064 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
3065 for (i = 0; i < pi->num_cmds; i++) {
3066 // TODO: do we really need to have so many fields which are just dead weight
3067 // at execution stage?
3068 thejob->cmds[i].pid = pi->cmds[i].pid;
3069 /* all other fields are not used and stay zero */
3071 thejob->next = NULL;
3072 thejob->cmdtext = xstrdup(get_cmdtext(pi));
3074 /* We don't wait for background thejobs to return -- append it
3075 to the list of backgrounded thejobs and leave it alone */
3076 if (G_interactive_fd)
3077 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
3078 G.last_bg_pid = thejob->cmds[0].pid;
3079 G.last_jobid = thejob->jobid;
3082 static void remove_bg_job(struct pipe *pi)
3084 struct pipe *prev_pipe;
3086 if (pi == G.job_list) {
3087 G.job_list = pi->next;
3089 prev_pipe = G.job_list;
3090 while (prev_pipe->next != pi)
3091 prev_pipe = prev_pipe->next;
3092 prev_pipe->next = pi->next;
3095 G.last_jobid = G.job_list->jobid;
3100 /* Remove a backgrounded job */
3101 static void delete_finished_bg_job(struct pipe *pi)
3104 pi->stopped_cmds = 0;
3110 /* Check to see if any processes have exited -- if they
3111 * have, figure out why and see if a job has completed */
3112 static int checkjobs(struct pipe* fg_pipe)
3122 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3125 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3126 // /* avoid doing syscall, nothing there anyway */
3129 attributes = WUNTRACED;
3130 if (fg_pipe == NULL)
3131 attributes |= WNOHANG;
3133 /* Do we do this right?
3134 * bash-3.00# sleep 20 | false
3136 * [3]+ Stopped sleep 20 | false
3137 * bash-3.00# echo $?
3138 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3141 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
3142 //are stopped. Testcase: "cat | cat" in a script (not on command line)
3143 // + killall -STOP cat
3150 // i = G.count_SIGCHLD;
3151 childpid = waitpid(-1, &status, attributes);
3152 if (childpid <= 0) {
3153 if (childpid && errno != ECHILD)
3154 bb_perror_msg("waitpid");
3155 // else /* Until next SIGCHLD, waitpid's are useless */
3156 // G.handled_SIGCHLD = i;
3159 dead = WIFEXITED(status) || WIFSIGNALED(status);
3162 if (WIFSTOPPED(status))
3163 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3164 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3165 if (WIFSIGNALED(status))
3166 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3167 childpid, WTERMSIG(status), WEXITSTATUS(status));
3168 if (WIFEXITED(status))
3169 debug_printf_jobs("pid %d exited, exitcode %d\n",
3170 childpid, WEXITSTATUS(status));
3172 /* Were we asked to wait for fg pipe? */
3174 for (i = 0; i < fg_pipe->num_cmds; i++) {
3175 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3176 if (fg_pipe->cmds[i].pid != childpid)
3178 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
3180 fg_pipe->cmds[i].pid = 0;
3181 fg_pipe->alive_cmds--;
3182 if (i == fg_pipe->num_cmds - 1) {
3183 /* last process gives overall exitstatus */
3184 rcode = WEXITSTATUS(status);
3185 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3188 fg_pipe->cmds[i].is_stopped = 1;
3189 fg_pipe->stopped_cmds++;
3191 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3192 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3193 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3194 /* All processes in fg pipe have exited/stopped */
3196 if (fg_pipe->alive_cmds)
3197 insert_bg_job(fg_pipe);
3201 /* There are still running processes in the fg pipe */
3202 goto wait_more; /* do waitpid again */
3204 /* it wasnt fg_pipe, look for process in bg pipes */
3208 /* We asked to wait for bg or orphaned children */
3209 /* No need to remember exitcode in this case */
3210 for (pi = G.job_list; pi; pi = pi->next) {
3211 for (i = 0; i < pi->num_cmds; i++) {
3212 if (pi->cmds[i].pid == childpid)
3213 goto found_pi_and_prognum;
3216 /* Happens when shell is used as init process (init=/bin/sh) */
3217 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3218 continue; /* do waitpid again */
3220 found_pi_and_prognum:
3223 pi->cmds[i].pid = 0;
3225 if (!pi->alive_cmds) {
3226 if (G_interactive_fd)
3227 printf(JOB_STATUS_FORMAT, pi->jobid,
3228 "Done", pi->cmdtext);
3229 delete_finished_bg_job(pi);
3233 pi->cmds[i].is_stopped = 1;
3237 } /* while (waitpid succeeds)... */
3243 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3246 int rcode = checkjobs(fg_pipe);
3247 /* Job finished, move the shell to the foreground */
3248 p = getpgid(0); /* pgid of our process */
3249 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3250 tcsetpgrp(G_interactive_fd, p);
3255 /* Start all the jobs, but don't wait for anything to finish.
3258 * Return code is normally -1, when the caller has to wait for children
3259 * to finish to determine the exit status of the pipe. If the pipe
3260 * is a simple builtin command, however, the action is done by the
3261 * time run_pipe returns, and the exit code is provided as the
3264 * Returns -1 only if started some children. IOW: we have to
3265 * mask out retvals of builtins etc with 0xff!
3267 * The only case when we do not need to [v]fork is when the pipe
3268 * is single, non-backgrounded, non-subshell command. Examples:
3269 * cmd ; ... { list } ; ...
3270 * cmd && ... { list } && ...
3271 * cmd || ... { list } || ...
3272 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3273 * or (if SH_STANDALONE) an applet, and we can run the { list }
3274 * with run_list(). If it isn't one of these, we fork and exec cmd.
3276 * Cases when we must fork:
3277 * non-single: cmd | cmd
3278 * backgrounded: cmd & { list } &
3279 * subshell: ( list ) [&]
3281 static int run_pipe(struct pipe *pi)
3283 static const char *const null_ptr = NULL;
3286 int pipefds[2]; /* pipefds[0] is for reading */
3287 struct command *command;
3288 char **argv_expanded;
3291 /* it is not always needed, but we aim to smaller code */
3292 int squirrel[] = { -1, -1, -1 };
3295 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3298 USE_HUSH_JOB(pi->pgrp = -1;)
3299 pi->stopped_cmds = 0;
3300 command = &(pi->cmds[0]);
3301 argv_expanded = NULL;
3303 if (pi->num_cmds != 1
3304 || pi->followup == PIPE_BG
3305 || command->grp_type == GRP_SUBSHELL
3312 debug_printf_exec(": group:%p argv:'%s'\n",
3313 command->group, command->argv ? command->argv[0] : "NONE");
3315 if (command->group) {
3316 #if ENABLE_HUSH_FUNCTIONS
3317 if (command->grp_type == GRP_FUNCTION) {
3318 /* "executing" func () { list } */
3319 struct function *funcp;
3321 funcp = new_function(command->argv[0]);
3322 /* funcp->name is already set to argv[0] */
3323 funcp->body = command->group;
3325 funcp->body_as_string = command->group_as_string;
3326 command->group_as_string = NULL;
3328 command->group = NULL;
3329 command->argv[0] = NULL;
3330 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3331 funcp->parent_cmd = command;
3332 command->child_func = funcp;
3334 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3336 return EXIT_SUCCESS;
3340 debug_printf("non-subshell group\n");
3341 rcode = 1; /* exitcode if redir failed */
3342 if (setup_redirects(command, squirrel) == 0) {
3343 debug_printf_exec(": run_list\n");
3344 rcode = run_list(command->group) & 0xff;
3346 restore_redirects(squirrel);
3347 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3349 debug_printf_exec("run_pipe: return %d\n", rcode);
3353 argv = command->argv ? command->argv : (char **) &null_ptr;
3355 const struct built_in_command *x;
3356 #if ENABLE_HUSH_FUNCTIONS
3357 const struct function *funcp;
3361 char **new_env = NULL;
3362 char **old_env = NULL;
3364 if (argv[command->assignment_cnt] == NULL) {
3365 /* Assignments, but no command */
3366 /* Ensure redirects take effect. Try "a=t >file" */
3367 rcode = setup_redirects(command, squirrel);
3368 restore_redirects(squirrel);
3369 /* Set shell variables */
3371 p = expand_string_to_string(*argv);
3372 debug_printf_exec("set shell var:'%s'->'%s'\n",
3374 set_local_var(p, 0, 0);
3377 /* Do we need to flag set_local_var() errors?
3378 * "assignment to readonly var" and "putenv error"
3380 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3382 debug_printf_exec("run_pipe: return %d\n", rcode);
3386 /* Expand the rest into (possibly) many strings each */
3387 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3389 x = find_builtin(argv_expanded[0]);
3390 #if ENABLE_HUSH_FUNCTIONS
3393 funcp = find_function(argv_expanded[0]);
3397 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3398 debug_printf("exec with redirects only\n");
3399 rcode = setup_redirects(command, NULL);
3400 goto clean_up_and_ret1;
3403 /* XXX setup_redirects acts on file descriptors, not FILEs.
3404 * This is perfect for work that comes after exec().
3405 * Is it really safe for inline use? Experimentally,
3406 * things seem to work with glibc. */
3407 rcode = setup_redirects(command, squirrel);
3409 new_env = expand_assignments(argv, command->assignment_cnt);
3410 old_env = putenv_all_and_save_old(new_env);
3412 debug_printf_exec(": builtin '%s' '%s'...\n",
3413 x->cmd, argv_expanded[1]);
3414 rcode = x->function(argv_expanded) & 0xff;
3416 #if ENABLE_HUSH_FUNCTIONS
3418 debug_printf_exec(": function '%s' '%s'...\n",
3419 funcp->name, argv_expanded[1]);
3420 rcode = run_function(funcp, argv_expanded) & 0xff;
3424 #if ENABLE_FEATURE_SH_STANDALONE
3427 restore_redirects(squirrel);
3428 free_strings_and_unsetenv(new_env, 1);
3429 putenv_all(old_env);
3430 /* Free the pointers, but the strings themselves
3431 * are in environ now, don't use free_strings! */
3434 free(argv_expanded);
3435 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3437 debug_printf_exec("run_pipe return %d\n", rcode);
3441 #if ENABLE_FEATURE_SH_STANDALONE
3442 i = find_applet_by_name(argv_expanded[0]);
3443 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3444 rcode = setup_redirects(command, squirrel);
3446 new_env = expand_assignments(argv, command->assignment_cnt);
3447 old_env = putenv_all_and_save_old(new_env);
3448 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3449 argv_expanded[0], argv_expanded[1]);
3450 rcode = run_nofork_applet(i, argv_expanded);
3452 goto clean_up_and_ret;
3455 /* It is neither builtin nor applet. We must fork. */
3459 /* NB: argv_expanded may already be created, and that
3460 * might include `cmd` runs! Do not rerun it! We *must*
3461 * use argv_expanded if it's non-NULL */
3463 /* Going to fork a child per each pipe member */
3467 for (i = 0; i < pi->num_cmds; i++) {
3469 volatile nommu_save_t nommu_save;
3470 nommu_save.new_env = NULL;
3471 nommu_save.old_env = NULL;
3472 nommu_save.argv = NULL;
3473 nommu_save.argv_from_re_execing = NULL;
3475 command = &(pi->cmds[i]);
3476 if (command->argv) {
3477 debug_printf_exec(": pipe member '%s' '%s'...\n",
3478 command->argv[0], command->argv[1]);
3480 debug_printf_exec(": pipe member with no argv\n");
3483 /* pipes are inserted between pairs of commands */
3486 if ((i + 1) < pi->num_cmds)
3489 command->pid = BB_MMU ? fork() : vfork();
3490 if (!command->pid) { /* child */
3492 disable_restore_tty_pgrp_on_exit();
3494 /* Every child adds itself to new process group
3495 * with pgid == pid_of_first_child_in_pipe */
3496 if (G.run_list_level == 1 && G_interactive_fd) {
3499 if (pgrp < 0) /* true for 1st process only */
3501 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3502 /* We do it in *every* child, not just first,
3504 tcsetpgrp(G_interactive_fd, pgrp);
3508 xmove_fd(nextin, 0);
3509 xmove_fd(pipefds[1], 1); /* write end */
3511 close(pipefds[0]); /* read end */
3512 /* Like bash, explicit redirects override pipes,
3513 * and the pipe fd is available for dup'ing. */
3514 if (setup_redirects(command, NULL))
3517 /* Restore default handlers just prior to exec */
3518 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3520 /* Stores to nommu_save list of env vars putenv'ed
3521 * (NOMMU, on MMU we don't need that) */
3522 /* cast away volatility... */
3523 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3524 /* pseudo_exec() does not return */
3527 /* parent or error */
3528 enable_restore_tty_pgrp_on_exit();
3530 /* Clean up after vforked child */
3531 free(nommu_save.argv);
3532 free(nommu_save.argv_from_re_execing);
3533 free_strings_and_unsetenv(nommu_save.new_env, 1);
3534 putenv_all(nommu_save.old_env);
3535 /* Free the pointers, but the strings themselves
3536 * are in environ now, don't use free_strings! */
3537 free(nommu_save.old_env);
3539 free(argv_expanded);
3540 argv_expanded = NULL;
3541 if (command->pid < 0) { /* [v]fork failed */
3542 /* Clearly indicate, was it fork or vfork */
3543 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3547 /* Second and next children need to know pid of first one */
3549 pi->pgrp = command->pid;
3555 if ((i + 1) < pi->num_cmds)
3556 close(pipefds[1]); /* write end */
3557 /* Pass read (output) pipe end to next iteration */
3558 nextin = pipefds[0];
3561 if (!pi->alive_cmds) {
3563 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3568 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3572 #ifndef debug_print_tree
3573 static void debug_print_tree(struct pipe *pi, int lvl)
3575 static const char *const PIPE[] = {
3581 static const char *RES[] = {
3582 [RES_NONE ] = "NONE" ,
3585 [RES_THEN ] = "THEN" ,
3586 [RES_ELIF ] = "ELIF" ,
3587 [RES_ELSE ] = "ELSE" ,
3590 #if ENABLE_HUSH_LOOPS
3591 [RES_FOR ] = "FOR" ,
3592 [RES_WHILE] = "WHILE",
3593 [RES_UNTIL] = "UNTIL",
3595 [RES_DONE ] = "DONE" ,
3597 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3600 #if ENABLE_HUSH_CASE
3601 [RES_CASE ] = "CASE" ,
3602 [RES_MATCH] = "MATCH",
3603 [RES_CASEI] = "CASEI",
3604 [RES_ESAC ] = "ESAC" ,
3606 [RES_XXXX ] = "XXXX" ,
3607 [RES_SNTX ] = "SNTX" ,
3609 static const char *const GRPTYPE[] = {
3612 #if ENABLE_HUSH_FUNCTIONS
3621 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3622 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3624 while (prn < pi->num_cmds) {
3625 struct command *command = &pi->cmds[prn];
3626 char **argv = command->argv;
3628 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3630 command->assignment_cnt);
3631 if (command->group) {
3632 fprintf(stderr, " group %s: (argv=%p)\n",
3633 GRPTYPE[command->grp_type],
3635 debug_print_tree(command->group, lvl+1);
3639 if (argv) while (*argv) {
3640 fprintf(stderr, " '%s'", *argv);
3643 fprintf(stderr, "\n");
3652 /* NB: called by pseudo_exec, and therefore must not modify any
3653 * global data until exec/_exit (we can be a child after vfork!) */
3654 static int run_list(struct pipe *pi)
3656 #if ENABLE_HUSH_CASE
3657 char *case_word = NULL;
3659 #if ENABLE_HUSH_LOOPS
3660 struct pipe *loop_top = NULL;
3661 char *for_varname = NULL;
3662 char **for_lcur = NULL;
3663 char **for_list = NULL;
3665 smallint last_followup;
3667 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3668 smalluint cond_code = 0;
3670 enum { cond_code = 0 };
3673 smallint rword; /* enum reserved_style */
3674 smallint last_rword; /* ditto */
3677 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3680 #if ENABLE_HUSH_LOOPS
3681 /* Check syntax for "for" */
3682 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3683 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3685 /* current word is FOR or IN (BOLD in comments below) */
3686 if (cpipe->next == NULL) {
3687 syntax_error("malformed for");
3689 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3692 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3693 if (cpipe->next->res_word == RES_DO)
3695 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3696 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3697 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3699 syntax_error("malformed for");
3701 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3707 /* Past this point, all code paths should jump to ret: label
3708 * in order to return, no direct "return" statements please.
3709 * This helps to ensure that no memory is leaked. */
3717 last_rword = RES_XXXX;
3719 last_followup = PIPE_SEQ;
3720 rcode = G.last_exitcode;
3722 /* Go through list of pipes, (maybe) executing them. */
3723 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3727 IF_HAS_KEYWORDS(rword = pi->res_word;)
3728 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3729 rword, cond_code, last_rword);
3730 #if ENABLE_HUSH_LOOPS
3731 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3732 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3734 /* start of a loop: remember where loop starts */
3739 /* Still in the same "if...", "then..." or "do..." branch? */
3740 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3741 if ((rcode == 0 && last_followup == PIPE_OR)
3742 || (rcode != 0 && last_followup == PIPE_AND)
3744 /* It is "<true> || CMD" or "<false> && CMD"
3745 * and we should not execute CMD */
3746 debug_printf_exec("skipped cmd because of || or &&\n");
3747 last_followup = pi->followup;
3751 last_followup = pi->followup;
3752 IF_HAS_KEYWORDS(last_rword = rword;)
3755 if (rword == RES_THEN) {
3756 /* if false; then ... fi has exitcode 0! */
3757 G.last_exitcode = rcode = EXIT_SUCCESS;
3758 /* "if <false> THEN cmd": skip cmd */
3762 if (rword == RES_ELSE || rword == RES_ELIF) {
3763 /* "if <true> then ... ELSE/ELIF cmd":
3764 * skip cmd and all following ones */
3769 #if ENABLE_HUSH_LOOPS
3770 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3772 /* first loop through for */
3774 static const char encoded_dollar_at[] ALIGN1 = {
3775 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3776 }; /* encoded representation of "$@" */
3777 static const char *const encoded_dollar_at_argv[] = {
3778 encoded_dollar_at, NULL
3779 }; /* argv list with one element: "$@" */
3782 vals = (char**)encoded_dollar_at_argv;
3783 if (pi->next->res_word == RES_IN) {
3784 /* if no variable values after "in" we skip "for" */
3785 if (!pi->next->cmds[0].argv) {
3786 G.last_exitcode = rcode = EXIT_SUCCESS;
3787 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3790 vals = pi->next->cmds[0].argv;
3791 } /* else: "for var; do..." -> assume "$@" list */
3792 /* create list of variable values */
3793 debug_print_strings("for_list made from", vals);
3794 for_list = expand_strvec_to_strvec(vals);
3795 for_lcur = for_list;
3796 debug_print_strings("for_list", for_list);
3797 for_varname = pi->cmds[0].argv[0];
3798 pi->cmds[0].argv[0] = NULL;
3800 free(pi->cmds[0].argv[0]);
3802 /* "for" loop is over, clean up */
3806 pi->cmds[0].argv[0] = for_varname;
3809 /* Insert next value from for_lcur */
3810 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3811 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3812 pi->cmds[0].assignment_cnt = 1;
3814 if (rword == RES_IN) {
3815 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3817 if (rword == RES_DONE) {
3818 continue; /* "done" has no cmds too */
3821 #if ENABLE_HUSH_CASE
3822 if (rword == RES_CASE) {
3823 case_word = expand_strvec_to_string(pi->cmds->argv);
3826 if (rword == RES_MATCH) {
3829 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3831 /* all prev words didn't match, does this one match? */
3832 argv = pi->cmds->argv;
3834 char *pattern = expand_string_to_string(*argv);
3835 /* TODO: which FNM_xxx flags to use? */
3836 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3838 if (cond_code == 0) { /* match! we will execute this branch */
3839 free(case_word); /* make future "word)" stop */
3847 if (rword == RES_CASEI) { /* inside of a case branch */
3849 continue; /* not matched yet, skip this pipe */
3852 /* Just pressing <enter> in shell should check for jobs.
3853 * OTOH, in non-interactive shell this is useless
3854 * and only leads to extra job checks */
3855 if (pi->num_cmds == 0) {
3856 if (G_interactive_fd)
3857 goto check_jobs_and_continue;
3861 /* After analyzing all keywords and conditions, we decided
3862 * to execute this pipe. NB: have to do checkjobs(NULL)
3863 * after run_pipe to collect any background children,
3864 * even if list execution is to be stopped. */
3865 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3868 #if ENABLE_HUSH_LOOPS
3869 G.flag_break_continue = 0;
3871 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3873 /* We only ran a builtin: rcode is already known
3874 * and we don't need to wait for anything. */
3875 G.last_exitcode = rcode;
3876 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3877 check_and_run_traps(0);
3878 #if ENABLE_HUSH_LOOPS
3879 /* Was it "break" or "continue"? */
3880 if (G.flag_break_continue) {
3881 smallint fbc = G.flag_break_continue;
3882 /* We might fall into outer *loop*,
3883 * don't want to break it too */
3885 G.depth_break_continue--;
3886 if (G.depth_break_continue == 0)
3887 G.flag_break_continue = 0;
3888 /* else: e.g. "continue 2" should *break* once, *then* continue */
3889 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3890 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3891 goto check_jobs_and_break;
3892 /* "continue": simulate end of loop */
3897 } else if (pi->followup == PIPE_BG) {
3898 /* What does bash do with attempts to background builtins? */
3899 /* even bash 3.2 doesn't do that well with nested bg:
3900 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3901 * I'm NOT treating inner &'s as jobs */
3902 check_and_run_traps(0);
3904 if (G.run_list_level == 1)
3907 G.last_exitcode = rcode = EXIT_SUCCESS;
3908 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3911 if (G.run_list_level == 1 && G_interactive_fd) {
3912 /* Waits for completion, then fg's main shell */
3913 rcode = checkjobs_and_fg_shell(pi);
3914 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3915 check_and_run_traps(0);
3918 { /* This one just waits for completion */
3919 rcode = checkjobs(pi);
3920 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3921 check_and_run_traps(0);
3923 G.last_exitcode = rcode;
3927 /* Analyze how result affects subsequent commands */
3929 if (rword == RES_IF || rword == RES_ELIF)
3932 #if ENABLE_HUSH_LOOPS
3933 /* Beware of "while false; true; do ..."! */
3934 if (pi->next && pi->next->res_word == RES_DO) {
3935 if (rword == RES_WHILE) {
3937 /* "while false; do...done" - exitcode 0 */
3938 G.last_exitcode = rcode = EXIT_SUCCESS;
3939 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3940 goto check_jobs_and_break;
3943 if (rword == RES_UNTIL) {
3945 debug_printf_exec(": until expr is true: breaking\n");
3946 check_jobs_and_break:
3954 check_jobs_and_continue:
3961 #if ENABLE_HUSH_LOOPS
3966 #if ENABLE_HUSH_CASE
3970 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3974 /* Select which version we will use */
3975 static int run_and_free_list(struct pipe *pi)
3978 debug_printf_exec("run_and_free_list entered\n");
3980 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3981 rcode = run_list(pi);
3983 /* free_pipe_list has the side effect of clearing memory.
3984 * In the long run that function can be merged with run_list,
3985 * but doing that now would hobble the debugging effort. */
3987 debug_printf_exec("run_and_free_list return %d\n", rcode);
3992 static struct pipe *new_pipe(void)
3995 pi = xzalloc(sizeof(struct pipe));
3996 /*pi->followup = 0; - deliberately invalid value */
3997 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4001 /* Command (member of a pipe) is complete, or we start a new pipe
4002 * if ctx->command is NULL.
4003 * No errors possible here.
4005 static int done_command(struct parse_context *ctx)
4007 /* The command is really already in the pipe structure, so
4008 * advance the pipe counter and make a new, null command. */
4009 struct pipe *pi = ctx->pipe;
4010 struct command *command = ctx->command;
4013 if (IS_NULL_CMD(command)) {
4014 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4018 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4019 //debug_print_tree(ctx->list_head, 20);
4021 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4024 /* Only real trickiness here is that the uncommitted
4025 * command structure is not counted in pi->num_cmds. */
4026 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4027 ctx->command = command = &pi->cmds[pi->num_cmds];
4029 memset(command, 0, sizeof(*command));
4030 return pi->num_cmds; /* used only for 0/nonzero check */
4033 static void done_pipe(struct parse_context *ctx, pipe_style type)
4037 debug_printf_parse("done_pipe entered, followup %d\n", type);
4038 /* Close previous command */
4039 not_null = done_command(ctx);
4040 ctx->pipe->followup = type;
4042 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4043 ctx->ctx_inverted = 0;
4044 ctx->pipe->res_word = ctx->ctx_res_w;
4047 /* Without this check, even just <enter> on command line generates
4048 * tree of three NOPs (!). Which is harmless but annoying.
4049 * IOW: it is safe to do it unconditionally. */
4052 || ctx->ctx_res_w == RES_FI
4054 #if ENABLE_HUSH_LOOPS
4055 || ctx->ctx_res_w == RES_DONE
4056 || ctx->ctx_res_w == RES_FOR
4057 || ctx->ctx_res_w == RES_IN
4059 #if ENABLE_HUSH_CASE
4060 || ctx->ctx_res_w == RES_ESAC
4064 debug_printf_parse("done_pipe: adding new pipe: "
4065 "not_null:%d ctx->ctx_res_w:%d\n",
4066 not_null, ctx->ctx_res_w);
4068 ctx->pipe->next = new_p;
4070 /* RES_THEN, RES_DO etc are "sticky" -
4071 * they remain set for pipes inside if/while.
4072 * This is used to control execution.
4073 * RES_FOR and RES_IN are NOT sticky (needed to support
4074 * cases where variable or value happens to match a keyword):
4076 #if ENABLE_HUSH_LOOPS
4077 if (ctx->ctx_res_w == RES_FOR
4078 || ctx->ctx_res_w == RES_IN)
4079 ctx->ctx_res_w = RES_NONE;
4081 #if ENABLE_HUSH_CASE
4082 if (ctx->ctx_res_w == RES_MATCH)
4083 ctx->ctx_res_w = RES_CASEI;
4085 ctx->command = NULL; /* trick done_command below */
4086 /* Create the memory for command, roughly:
4087 * ctx->pipe->cmds = new struct command;
4088 * ctx->command = &ctx->pipe->cmds[0];
4091 //debug_print_tree(ctx->list_head, 10);
4093 debug_printf_parse("done_pipe return\n");
4096 static void initialize_context(struct parse_context *ctx)
4098 memset(ctx, 0, sizeof(*ctx));
4099 ctx->pipe = ctx->list_head = new_pipe();
4100 /* Create the memory for command, roughly:
4101 * ctx->pipe->cmds = new struct command;
4102 * ctx->command = &ctx->pipe->cmds[0];
4107 /* If a reserved word is found and processed, parse context is modified
4108 * and 1 is returned.
4111 struct reserved_combo {
4114 unsigned char assignment_flag;
4118 FLAG_END = (1 << RES_NONE ),
4120 FLAG_IF = (1 << RES_IF ),
4121 FLAG_THEN = (1 << RES_THEN ),
4122 FLAG_ELIF = (1 << RES_ELIF ),
4123 FLAG_ELSE = (1 << RES_ELSE ),
4124 FLAG_FI = (1 << RES_FI ),
4126 #if ENABLE_HUSH_LOOPS
4127 FLAG_FOR = (1 << RES_FOR ),
4128 FLAG_WHILE = (1 << RES_WHILE),
4129 FLAG_UNTIL = (1 << RES_UNTIL),
4130 FLAG_DO = (1 << RES_DO ),
4131 FLAG_DONE = (1 << RES_DONE ),
4132 FLAG_IN = (1 << RES_IN ),
4134 #if ENABLE_HUSH_CASE
4135 FLAG_MATCH = (1 << RES_MATCH),
4136 FLAG_ESAC = (1 << RES_ESAC ),
4138 FLAG_START = (1 << RES_XXXX ),
4141 static const struct reserved_combo* match_reserved_word(o_string *word)
4143 /* Mostly a list of accepted follow-up reserved words.
4144 * FLAG_END means we are done with the sequence, and are ready
4145 * to turn the compound list into a command.
4146 * FLAG_START means the word must start a new compound list.
4148 static const struct reserved_combo reserved_list[] = {
4150 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4151 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4152 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4153 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4154 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4155 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4157 #if ENABLE_HUSH_LOOPS
4158 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4159 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4160 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4161 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4162 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4163 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4165 #if ENABLE_HUSH_CASE
4166 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4167 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4170 const struct reserved_combo *r;
4172 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4173 if (strcmp(word->data, r->literal) == 0)
4178 /* Return 0: not a keyword, 1: keyword
4180 static int reserved_word(o_string *word, struct parse_context *ctx)
4182 #if ENABLE_HUSH_CASE
4183 static const struct reserved_combo reserved_match = {
4184 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4187 const struct reserved_combo *r;
4191 r = match_reserved_word(word);
4195 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4196 #if ENABLE_HUSH_CASE
4197 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4198 /* "case word IN ..." - IN part starts first match part */
4199 r = &reserved_match;
4202 if (r->flag == 0) { /* '!' */
4203 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4204 syntax_error("! ! command");
4205 ctx->ctx_res_w = RES_SNTX;
4207 ctx->ctx_inverted = 1;
4210 if (r->flag & FLAG_START) {
4211 struct parse_context *old;
4213 old = xmalloc(sizeof(*old));
4214 debug_printf_parse("push stack %p\n", old);
4215 *old = *ctx; /* physical copy */
4216 initialize_context(ctx);
4218 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4219 syntax_error_at(word->data);
4220 ctx->ctx_res_w = RES_SNTX;
4223 /* "{...} fi" is ok. "{...} if" is not
4225 * if { echo foo; } then { echo bar; } fi */
4226 if (ctx->command->group)
4227 done_pipe(ctx, PIPE_SEQ);
4230 ctx->ctx_res_w = r->res;
4231 ctx->old_flag = r->flag;
4232 word->o_assignment = r->assignment_flag;
4234 if (ctx->old_flag & FLAG_END) {
4235 struct parse_context *old;
4237 done_pipe(ctx, PIPE_SEQ);
4238 debug_printf_parse("pop stack %p\n", ctx->stack);
4240 old->command->group = ctx->list_head;
4241 old->command->grp_type = GRP_NORMAL;
4243 o_addstr(&old->as_string, ctx->as_string.data);
4244 o_free_unsafe(&ctx->as_string);
4245 old->command->group_as_string = xstrdup(old->as_string.data);
4246 debug_printf_parse("pop, remembering as:'%s'\n",
4247 old->command->group_as_string);
4249 *ctx = *old; /* physical copy */
4256 /* Word is complete, look at it and update parsing context.
4257 * Normal return is 0. Syntax errors return 1.
4258 * Note: on return, word is reset, but not o_free'd!
4260 static int done_word(o_string *word, struct parse_context *ctx)
4262 struct command *command = ctx->command;
4264 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4265 if (word->length == 0 && word->o_quoted == 0) {
4266 debug_printf_parse("done_word return 0: true null, ignored\n");
4270 if (ctx->pending_redirect) {
4271 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4272 * only if run as "bash", not "sh" */
4273 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4275 * ...the word that follows the redirection operator
4276 * shall be subjected to tilde expansion, parameter expansion,
4277 * command substitution, arithmetic expansion, and quote
4278 * removal. Pathname expansion shall not be performed
4279 * on the word by a non-interactive shell; an interactive
4280 * shell may perform it, but shall do so only when
4281 * the expansion would result in one word."
4283 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4284 /* Cater for >\file case:
4285 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4286 * Same with heredocs:
4287 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4289 unbackslash(ctx->pending_redirect->rd_filename);
4290 /* Is it <<"HEREDOC"? */
4291 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4294 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4296 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4297 ctx->pending_redirect = NULL;
4299 /* If this word wasn't an assignment, next ones definitely
4300 * can't be assignments. Even if they look like ones. */
4301 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4302 && word->o_assignment != WORD_IS_KEYWORD
4304 word->o_assignment = NOT_ASSIGNMENT;
4306 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4307 command->assignment_cnt++;
4308 word->o_assignment = MAYBE_ASSIGNMENT;
4312 # if ENABLE_HUSH_CASE
4313 if (ctx->ctx_dsemicolon
4314 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4316 /* already done when ctx_dsemicolon was set to 1: */
4317 /* ctx->ctx_res_w = RES_MATCH; */
4318 ctx->ctx_dsemicolon = 0;
4321 if (!command->argv /* if it's the first word... */
4322 # if ENABLE_HUSH_LOOPS
4323 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4324 && ctx->ctx_res_w != RES_IN
4327 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4328 if (reserved_word(word, ctx)) {
4329 o_reset_to_empty_unquoted(word);
4330 debug_printf_parse("done_word return %d\n",
4331 (ctx->ctx_res_w == RES_SNTX));
4332 return (ctx->ctx_res_w == RES_SNTX);
4336 if (command->group) {
4337 /* "{ echo foo; } echo bar" - bad */
4338 syntax_error_at(word->data);
4339 debug_printf_parse("done_word return 1: syntax error, "
4340 "groups and arglists don't mix\n");
4343 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4344 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4345 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4346 /* (otherwise it's known to be not empty and is already safe) */
4348 /* exclude "$@" - it can expand to no word despite "" */
4349 char *p = word->data;
4350 while (p[0] == SPECIAL_VAR_SYMBOL
4351 && (p[1] & 0x7f) == '@'
4352 && p[2] == SPECIAL_VAR_SYMBOL
4356 if (p == word->data || p[0] != '\0') {
4357 /* saw no "$@", or not only "$@" but some
4358 * real text is there too */
4359 /* insert "empty variable" reference, this makes
4360 * e.g. "", $empty"" etc to not disappear */
4361 o_addchr(word, SPECIAL_VAR_SYMBOL);
4362 o_addchr(word, SPECIAL_VAR_SYMBOL);
4365 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4366 //SEGV, but good idea.
4367 // command->argv = add_string_to_strings(command->argv, word->data);
4368 // word->data = NULL;
4369 // word->length = 0;
4370 debug_print_strings("word appended to argv", command->argv);
4373 #if ENABLE_HUSH_LOOPS
4374 if (ctx->ctx_res_w == RES_FOR) {
4376 || !is_well_formed_var_name(command->argv[0], '\0')
4378 /* bash says just "not a valid identifier" */
4379 syntax_error("not a valid identifier in for");
4382 /* Force FOR to have just one word (variable name) */
4383 /* NB: basically, this makes hush see "for v in ..."
4384 * syntax as if it is "for v; in ...". FOR and IN become
4385 * two pipe structs in parse tree. */
4386 done_pipe(ctx, PIPE_SEQ);
4389 #if ENABLE_HUSH_CASE
4390 /* Force CASE to have just one word */
4391 if (ctx->ctx_res_w == RES_CASE) {
4392 done_pipe(ctx, PIPE_SEQ);
4396 o_reset_to_empty_unquoted(word);
4398 debug_printf_parse("done_word return 0\n");
4403 /* Peek ahead in the input to find out if we have a "&n" construct,
4404 * as in "2>&1", that represents duplicating a file descriptor.
4406 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4407 * REDIRFD_SYNTAX_ERR if syntax error,
4408 * REDIRFD_TO_FILE if no & was seen,
4409 * or the number found.
4412 #define parse_redir_right_fd(as_string, input) \
4413 parse_redir_right_fd(input)
4415 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4421 return REDIRFD_TO_FILE;
4423 ch = i_getch(input); /* get the & */
4424 nommu_addchr(as_string, ch);
4427 ch = i_getch(input);
4428 nommu_addchr(as_string, ch);
4429 return REDIRFD_CLOSE;
4433 while (ch != EOF && isdigit(ch)) {
4434 d = d*10 + (ch-'0');
4436 ch = i_getch(input);
4437 nommu_addchr(as_string, ch);
4442 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4444 bb_error_msg("ambiguous redirect");
4445 return REDIRFD_SYNTAX_ERR;
4448 /* Return code is 0 normal, 1 if a syntax error is detected
4450 static int parse_redirect(struct parse_context *ctx,
4453 struct in_str *input)
4455 struct command *command = ctx->command;
4456 struct redir_struct *redir;
4457 struct redir_struct **redirp;
4460 dup_num = REDIRFD_TO_FILE;
4461 if (style != REDIRECT_HEREDOC) {
4462 /* Check for a '>&1' type redirect */
4463 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4464 if (dup_num == REDIRFD_SYNTAX_ERR)
4467 int ch = i_peek(input);
4468 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4469 if (dup_num) { /* <<-... */
4470 ch = i_getch(input);
4471 nommu_addchr(&ctx->as_string, ch);
4476 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4477 int ch = i_peek(input);
4479 /* >|FILE redirect ("clobbering" >).
4480 * Since we do not support "set -o noclobber" yet,
4481 * >| and > are the same for now. Just eat |.
4483 ch = i_getch(input);
4484 nommu_addchr(&ctx->as_string, ch);
4488 /* Create a new redir_struct and append it to the linked list */
4489 redirp = &command->redirects;
4490 while ((redir = *redirp) != NULL) {
4491 redirp = &(redir->next);
4493 *redirp = redir = xzalloc(sizeof(*redir));
4494 /* redir->next = NULL; */
4495 /* redir->rd_filename = NULL; */
4496 redir->rd_type = style;
4497 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4499 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4500 redir_table[style].descrip);
4502 redir->rd_dup = dup_num;
4503 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4504 /* Erik had a check here that the file descriptor in question
4505 * is legit; I postpone that to "run time"
4506 * A "-" representation of "close me" shows up as a -3 here */
4507 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4508 redir->rd_fd, redir->rd_dup);
4510 /* Set ctx->pending_redirect, so we know what to do at the
4511 * end of the next parsed word. */
4512 ctx->pending_redirect = redir;
4517 /* If a redirect is immediately preceded by a number, that number is
4518 * supposed to tell which file descriptor to redirect. This routine
4519 * looks for such preceding numbers. In an ideal world this routine
4520 * needs to handle all the following classes of redirects...
4521 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4522 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4523 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4524 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4526 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4528 * ... If n is quoted, the number shall not be recognized as part of
4529 * the redirection expression. For example:
4531 * writes the character 2 into file a"
4532 * We are getting it right by setting ->o_quoted on any \<char>
4534 * A -1 return means no valid number was found,
4535 * the caller should use the appropriate default for this redirection.
4537 static int redirect_opt_num(o_string *o)
4541 if (o->data == NULL)
4543 num = bb_strtou(o->data, NULL, 10);
4544 if (errno || num < 0)
4546 o_reset_to_empty_unquoted(o);
4551 #define fetch_till_str(as_string, input, word, skip_tabs) \
4552 fetch_till_str(input, word, skip_tabs)
4554 static char *fetch_till_str(o_string *as_string,
4555 struct in_str *input,
4559 o_string heredoc = NULL_O_STRING;
4565 ch = i_getch(input);
4566 nommu_addchr(as_string, ch);
4568 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4569 heredoc.data[past_EOL] = '\0';
4570 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4571 return heredoc.data;
4574 o_addchr(&heredoc, ch);
4575 past_EOL = heredoc.length;
4578 ch = i_getch(input);
4579 nommu_addchr(as_string, ch);
4580 } while (skip_tabs && ch == '\t');
4581 } while (ch == '\n');
4584 o_free_unsafe(&heredoc);
4587 o_addchr(&heredoc, ch);
4588 nommu_addchr(as_string, ch);
4592 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4593 * and load them all. There should be exactly heredoc_cnt of them.
4595 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4597 struct pipe *pi = ctx->list_head;
4599 while (pi && heredoc_cnt) {
4601 struct command *cmd = pi->cmds;
4603 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4605 cmd->argv ? cmd->argv[0] : "NONE");
4606 for (i = 0; i < pi->num_cmds; i++) {
4607 struct redir_struct *redir = cmd->redirects;
4609 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4610 i, cmd->argv ? cmd->argv[0] : "NONE");
4612 if (redir->rd_type == REDIRECT_HEREDOC) {
4615 redir->rd_type = REDIRECT_HEREDOC2;
4616 /* redir->dup is (ab)used to indicate <<- */
4617 p = fetch_till_str(&ctx->as_string, input,
4618 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4620 syntax_error("unexpected EOF in here document");
4623 free(redir->rd_filename);
4624 redir->rd_filename = p;
4627 redir = redir->next;
4634 /* Should be 0. If it isn't, it's a parse error */
4636 bb_error_msg_and_die("heredoc BUG 2");
4642 #if ENABLE_HUSH_TICK
4643 static FILE *generate_stream_from_string(const char *s)
4646 int pid, channel[2];
4652 pid = BB_MMU ? fork() : vfork();
4654 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4656 if (pid == 0) { /* child */
4657 disable_restore_tty_pgrp_on_exit();
4658 /* Process substitution is not considered to be usual
4659 * 'command execution'.
4660 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4667 close(channel[0]); /* NB: close _first_, then move fd! */
4668 xmove_fd(channel[1], 1);
4669 /* Prevent it from trying to handle ctrl-z etc */
4670 USE_HUSH_JOB(G.run_list_level = 1;)
4672 reset_traps_to_defaults();
4673 parse_and_run_string(s);
4674 _exit(G.last_exitcode);
4676 /* We re-execute after vfork on NOMMU. This makes this script safe:
4677 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4678 * huge=`cat BIG` # was blocking here forever
4681 re_execute_shell(&to_free,
4689 enable_restore_tty_pgrp_on_exit();
4694 pf = fdopen(channel[0], "r");
4698 /* Return code is exit status of the process that is run. */
4699 static int process_command_subs(o_string *dest, const char *s)
4702 struct in_str pipe_str;
4705 pf = generate_stream_from_string(s);
4708 close_on_exec_on(fileno(pf));
4710 /* Now send results of command back into original context */
4711 setup_file_in_str(&pipe_str, pf);
4713 while ((ch = i_getch(&pipe_str)) != EOF) {
4719 o_addchr(dest, '\n');
4722 o_addQchr(dest, ch);
4725 debug_printf("done reading from pipe, pclose()ing\n");
4726 /* Note: we got EOF, and we just close the read end of the pipe.
4727 * We do not wait for the `cmd` child to terminate. bash and ash do.
4729 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4730 * `false`; echo $? - bash outputs "1"
4733 debug_printf("closed FILE from child. return 0\n");
4738 static int parse_group(o_string *dest, struct parse_context *ctx,
4739 struct in_str *input, int ch)
4741 /* dest contains characters seen prior to ( or {.
4742 * Typically it's empty, but for function defs,
4743 * it contains function name (without '()'). */
4744 struct pipe *pipe_list;
4746 struct command *command = ctx->command;
4748 debug_printf_parse("parse_group entered\n");
4749 #if ENABLE_HUSH_FUNCTIONS
4750 if (ch == '(' && !dest->o_quoted) {
4752 if (done_word(dest, ctx))
4755 goto skip; /* (... */
4756 if (command->argv[1]) { /* word word ... (... */
4757 syntax_error_unexpected_ch('(');
4760 /* it is "word(..." or "word (..." */
4762 ch = i_getch(input);
4763 while (ch == ' ' || ch == '\t');
4765 syntax_error_unexpected_ch(ch);
4768 nommu_addchr(&ctx->as_string, ch);
4770 ch = i_getch(input);
4771 while (ch == ' ' || ch == '\t' || ch == '\n');
4773 syntax_error_unexpected_ch(ch);
4776 nommu_addchr(&ctx->as_string, ch);
4777 command->grp_type = GRP_FUNCTION;
4781 if (command->argv /* word [word]{... */
4782 || dest->length /* word{... */
4783 || dest->o_quoted /* ""{... */
4786 debug_printf_parse("parse_group return 1: "
4787 "syntax error, groups and arglists don't mix\n");
4791 #if ENABLE_HUSH_FUNCTIONS
4797 command->grp_type = GRP_SUBSHELL;
4799 /* bash does not allow "{echo...", requires whitespace */
4800 ch = i_getch(input);
4801 if (ch != ' ' && ch != '\t' && ch != '\n') {
4802 syntax_error_unexpected_ch(ch);
4805 nommu_addchr(&ctx->as_string, ch);
4810 char *as_string = NULL;
4812 pipe_list = parse_stream(&as_string, input, endch);
4815 o_addstr(&ctx->as_string, as_string);
4817 /* empty ()/{} or parse error? */
4818 if (!pipe_list || pipe_list == ERR_PTR) {
4819 /* parse_stream already emitted error msg */
4823 debug_printf_parse("parse_group return 1: "
4824 "parse_stream returned %p\n", pipe_list);
4827 command->group = pipe_list;
4829 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4830 command->group_as_string = as_string;
4831 debug_printf_parse("end of group, remembering as:'%s'\n",
4832 command->group_as_string);
4835 debug_printf_parse("parse_group return 0\n");
4837 /* command remains "open", available for possible redirects */
4840 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4841 /* Subroutines for copying $(...) and `...` things */
4842 static void add_till_backquote(o_string *dest, struct in_str *input);
4844 static void add_till_single_quote(o_string *dest, struct in_str *input)
4847 int ch = i_getch(input);
4849 syntax_error_unterm_ch('\'');
4850 /*xfunc_die(); - redundant */
4857 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4858 static void add_till_double_quote(o_string *dest, struct in_str *input)
4861 int ch = i_getch(input);
4863 syntax_error_unterm_ch('"');
4864 /*xfunc_die(); - redundant */
4868 if (ch == '\\') { /* \x. Copy both chars. */
4870 ch = i_getch(input);
4874 add_till_backquote(dest, input);
4878 //if (ch == '$') ...
4881 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4883 * "Within the backquoted style of command substitution, backslash
4884 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4885 * The search for the matching backquote shall be satisfied by the first
4886 * backquote found without a preceding backslash; during this search,
4887 * if a non-escaped backquote is encountered within a shell comment,
4888 * a here-document, an embedded command substitution of the $(command)
4889 * form, or a quoted string, undefined results occur. A single-quoted
4890 * or double-quoted string that begins, but does not end, within the
4891 * "`...`" sequence produces undefined results."
4893 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4895 static void add_till_backquote(o_string *dest, struct in_str *input)
4898 int ch = i_getch(input);
4900 syntax_error_unterm_ch('`');
4901 /*xfunc_die(); - redundant */
4906 /* \x. Copy both chars unless it is \` */
4907 int ch2 = i_getch(input);
4909 syntax_error_unterm_ch('`');
4910 /*xfunc_die(); - redundant */
4912 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4919 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4920 * quoting and nested ()s.
4921 * "With the $(command) style of command substitution, all characters
4922 * following the open parenthesis to the matching closing parenthesis
4923 * constitute the command. Any valid shell script can be used for command,
4924 * except a script consisting solely of redirections which produces
4925 * unspecified results."
4927 * echo $(echo '(TEST)' BEST) (TEST) BEST
4928 * echo $(echo 'TEST)' BEST) TEST) BEST
4929 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4931 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4935 int ch = i_getch(input);
4937 syntax_error_unterm_ch(')');
4938 /*xfunc_die(); - redundant */
4946 if (i_peek(input) == ')') {
4954 add_till_single_quote(dest, input);
4959 add_till_double_quote(dest, input);
4964 /* \x. Copy verbatim. Important for \(, \) */
4965 ch = i_getch(input);
4967 syntax_error_unterm_ch(')');
4968 /*xfunc_die(); - redundant */
4975 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4977 /* Return code: 0 for OK, 1 for syntax error */
4979 #define handle_dollar(as_string, dest, input) \
4980 handle_dollar(dest, input)
4982 static int handle_dollar(o_string *as_string,
4984 struct in_str *input)
4987 int ch = i_peek(input); /* first character after the $ */
4988 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4990 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4992 ch = i_getch(input);
4993 nommu_addchr(as_string, ch);
4995 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4997 debug_printf_parse(": '%c'\n", ch);
4998 o_addchr(dest, ch | quote_mask);
5001 if (!isalnum(ch) && ch != '_')
5003 ch = i_getch(input);
5004 nommu_addchr(as_string, ch);
5006 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5007 } else if (isdigit(ch)) {
5009 ch = i_getch(input);
5010 nommu_addchr(as_string, ch);
5011 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5012 debug_printf_parse(": '%c'\n", ch);
5013 o_addchr(dest, ch | quote_mask);
5014 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5015 } else switch (ch) {
5017 case '!': /* last bg pid */
5018 case '?': /* last exit code */
5019 case '#': /* number of args */
5020 case '*': /* args */
5021 case '@': /* args */
5022 goto make_one_char_var;
5024 bool first_char, all_digits;
5026 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5027 ch = i_getch(input);
5028 nommu_addchr(as_string, ch);
5029 /* XXX maybe someone will try to escape the '}' */
5034 ch = i_getch(input);
5035 nommu_addchr(as_string, ch);
5041 /* ${#var}: length of var contents */
5043 else if (isdigit(ch)) {
5050 && ( (all_digits && !isdigit(ch))
5051 || (!all_digits && !isalnum(ch) && ch != '_')
5054 /* handle parameter expansions
5055 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5060 case ':': /* null modifier */
5061 if (expansion == 0) {
5062 debug_printf_parse(": null modifier\n");
5067 case '#': /* remove prefix */
5068 case '%': /* remove suffix */
5069 if (expansion == 0) {
5070 debug_printf_parse(": remove suffix/prefix\n");
5075 case '-': /* default value */
5076 case '=': /* assign default */
5077 case '+': /* alternative */
5078 case '?': /* error indicate */
5079 debug_printf_parse(": parameter expansion\n");
5084 syntax_error_unterm_str("${name}");
5085 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5090 debug_printf_parse(": '%c'\n", ch);
5091 o_addchr(dest, ch | quote_mask);
5095 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5098 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5103 ch = i_getch(input);
5104 nommu_addchr(as_string, ch);
5105 # if ENABLE_SH_MATH_SUPPORT
5106 if (i_peek(input) == '(') {
5107 ch = i_getch(input);
5108 nommu_addchr(as_string, ch);
5109 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5110 o_addchr(dest, /*quote_mask |*/ '+');
5114 add_till_closing_paren(dest, input, true);
5117 o_addstr(as_string, dest->data + pos);
5118 o_addchr(as_string, ')');
5119 o_addchr(as_string, ')');
5122 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5126 # if ENABLE_HUSH_TICK
5127 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5128 o_addchr(dest, quote_mask | '`');
5132 add_till_closing_paren(dest, input, false);
5135 o_addstr(as_string, dest->data + pos);
5136 o_addchr(as_string, '`');
5139 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5145 ch = i_getch(input);
5146 nommu_addchr(as_string, ch);
5148 if (isalnum(ch)) { /* it's $_name or $_123 */
5154 /* $_ Shell or shell script name; or last cmd name */
5155 /* $- Option flags set by set builtin or shell options (-i etc) */
5157 o_addQchr(dest, '$');
5159 debug_printf_parse("handle_dollar return 0\n");
5164 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5165 parse_stream_dquoted(dest, input, dquote_end)
5167 static int parse_stream_dquoted(o_string *as_string,
5169 struct in_str *input,
5176 ch = i_getch(input);
5178 nommu_addchr(as_string, ch);
5179 if (ch == dquote_end) { /* may be only '"' or EOF */
5180 if (dest->o_assignment == NOT_ASSIGNMENT)
5181 dest->o_escape ^= 1;
5182 debug_printf_parse("parse_stream_dquoted return 0\n");
5185 /* note: can't move it above ch == dquote_end check! */
5187 syntax_error_unterm_ch('"');
5188 /*xfunc_die(); - redundant */
5192 next = i_peek(input);
5194 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5195 ch, ch, dest->o_escape);
5198 syntax_error("\\<eof>");
5202 * "The backslash retains its special meaning [in "..."]
5203 * only when followed by one of the following characters:
5204 * $, `, ", \, or <newline>. A double quote may be quoted
5205 * within double quotes by preceding it with a backslash.
5207 if (strchr("$`\"\\", next) != NULL) {
5208 o_addqchr(dest, i_getch(input));
5210 o_addqchr(dest, '\\');
5215 if (handle_dollar(as_string, dest, input) != 0) {
5216 debug_printf_parse("parse_stream_dquoted return 1: "
5217 "handle_dollar returned non-0\n");
5222 #if ENABLE_HUSH_TICK
5224 //int pos = dest->length;
5225 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5226 o_addchr(dest, 0x80 | '`');
5227 add_till_backquote(dest, input);
5228 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5229 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5233 o_addQchr(dest, ch);
5235 && (dest->o_assignment == MAYBE_ASSIGNMENT
5236 || dest->o_assignment == WORD_IS_KEYWORD)
5237 && is_well_formed_var_name(dest->data, '=')
5239 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5245 * Scan input until EOF or end_trigger char.
5246 * Return a list of pipes to execute, or NULL on EOF
5247 * or if end_trigger character is met.
5248 * On syntax error, exit is shell is not interactive,
5249 * reset parsing machinery and start parsing anew,
5250 * or return ERR_PTR.
5252 static struct pipe *parse_stream(char **pstring,
5253 struct in_str *input,
5256 struct parse_context ctx;
5257 o_string dest = NULL_O_STRING;
5261 /* Double-quote state is handled in the state variable is_in_dquote.
5262 * A single-quote triggers a bypass of the main loop until its mate is
5263 * found. When recursing, quote state is passed in via dest->o_escape.
5265 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5266 end_trigger ? : 'X');
5269 G.ifs = get_local_var_value("IFS");
5274 #if ENABLE_HUSH_INTERACTIVE
5275 input->promptmode = 0; /* PS1 */
5277 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5278 initialize_context(&ctx);
5283 const char *is_special;
5287 redir_type redir_style;
5290 /* dest.o_quoted = 1; - already is (see below) */
5291 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5294 /* We reached closing '"' */
5297 ch = i_getch(input);
5298 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5299 ch, ch, dest.o_escape);
5304 syntax_error_unterm_str("here document");
5307 if (done_word(&dest, &ctx)) {
5311 done_pipe(&ctx, PIPE_SEQ);
5313 /* If we got nothing... */
5314 /* (this makes bare "&" cmd a no-op.
5315 * bash says: "syntax error near unexpected token '&'") */
5316 if (pi->num_cmds == 0
5317 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5323 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5325 *pstring = ctx.as_string.data;
5327 o_free_unsafe(&ctx.as_string);
5330 debug_printf_parse("parse_stream return %p\n", pi);
5333 nommu_addchr(&ctx.as_string, ch);
5334 is_ifs = strchr(G.ifs, ch);
5335 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5336 "\\$\"" USE_HUSH_TICK("`") /* always special */
5339 if (!is_special && !is_ifs) { /* ordinary char */
5340 o_addQchr(&dest, ch);
5341 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5342 || dest.o_assignment == WORD_IS_KEYWORD)
5344 && is_well_formed_var_name(dest.data, '=')
5346 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5352 if (done_word(&dest, &ctx)) {
5356 #if ENABLE_HUSH_CASE
5357 /* "case ... in <newline> word) ..." -
5358 * newlines are ignored (but ';' wouldn't be) */
5359 if (ctx.command->argv == NULL
5360 && ctx.ctx_res_w == RES_MATCH
5365 /* Treat newline as a command separator. */
5366 done_pipe(&ctx, PIPE_SEQ);
5367 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5369 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5374 dest.o_assignment = MAYBE_ASSIGNMENT;
5376 /* note: if (is_ifs) continue;
5377 * will still trigger for us */
5380 if (end_trigger && end_trigger == ch
5381 && (heredoc_cnt == 0 || end_trigger != ';')
5384 /* This is technically valid:
5385 * { cat <<HERE; }; echo Ok
5389 * but we don't support this.
5390 * We require heredoc to be in enclosing {}/(),
5393 syntax_error_unterm_str("here document");
5396 if (done_word(&dest, &ctx)) {
5399 /* Disallow "{ cmd }" without semicolon or & */
5400 //debug_printf_parse("null pi %d\n", IS_NULL_PIPE(ctx.pipe))
5401 //debug_printf_parse("null cmd %d\n", IS_NULL_CMD(ctx.command))
5403 && !(IS_NULL_PIPE(ctx.pipe) && IS_NULL_CMD(ctx.command))
5405 syntax_error_unexpected_ch(ch);
5408 done_pipe(&ctx, PIPE_SEQ);
5409 dest.o_assignment = MAYBE_ASSIGNMENT;
5410 /* Do we sit outside of any if's, loops or case's? */
5412 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5416 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5418 *pstring = ctx.as_string.data;
5420 o_free_unsafe(&ctx.as_string);
5423 debug_printf_parse("parse_stream return %p: "
5424 "end_trigger char found\n",
5426 return ctx.list_head;
5434 next = i_peek(input);
5437 /* Catch <, > before deciding whether this word is
5438 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5441 redir_fd = redirect_opt_num(&dest);
5442 if (done_word(&dest, &ctx)) {
5445 redir_style = REDIRECT_OVERWRITE;
5447 redir_style = REDIRECT_APPEND;
5448 ch = i_getch(input);
5449 nommu_addchr(&ctx.as_string, ch);
5452 else if (next == '(') {
5453 syntax_error(">(process) not supported");
5457 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5459 continue; /* back to top of while (1) */
5461 redir_fd = redirect_opt_num(&dest);
5462 if (done_word(&dest, &ctx)) {
5465 redir_style = REDIRECT_INPUT;
5467 redir_style = REDIRECT_HEREDOC;
5469 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5470 ch = i_getch(input);
5471 nommu_addchr(&ctx.as_string, ch);
5472 } else if (next == '>') {
5473 redir_style = REDIRECT_IO;
5474 ch = i_getch(input);
5475 nommu_addchr(&ctx.as_string, ch);
5478 else if (next == '(') {
5479 syntax_error("<(process) not supported");
5483 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5485 continue; /* back to top of while (1) */
5488 if (dest.o_assignment == MAYBE_ASSIGNMENT
5489 /* check that we are not in word in "a=1 2>word b=1": */
5490 && !ctx.pending_redirect
5492 /* ch is a special char and thus this word
5493 * cannot be an assignment */
5494 dest.o_assignment = NOT_ASSIGNMENT;
5499 if (dest.length == 0) {
5502 if (ch == EOF || ch == '\n')
5505 /* note: we do not add it to &ctx.as_string */
5507 nommu_addchr(&ctx.as_string, '\n');
5509 o_addQchr(&dest, ch);
5514 syntax_error("\\<eof>");
5517 o_addchr(&dest, '\\');
5518 ch = i_getch(input);
5519 nommu_addchr(&ctx.as_string, ch);
5520 o_addchr(&dest, ch);
5521 /* Example: echo Hello \2>file
5522 * we need to know that word 2 is quoted */
5526 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5527 debug_printf_parse("parse_stream parse error: "
5528 "handle_dollar returned non-0\n");
5535 ch = i_getch(input);
5537 syntax_error_unterm_ch('\'');
5538 /*xfunc_die(); - redundant */
5540 nommu_addchr(&ctx.as_string, ch);
5543 if (dest.o_assignment == NOT_ASSIGNMENT)
5544 o_addqchr(&dest, ch);
5546 o_addchr(&dest, ch);
5551 is_in_dquote ^= 1; /* invert */
5552 if (dest.o_assignment == NOT_ASSIGNMENT)
5555 #if ENABLE_HUSH_TICK
5560 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5561 o_addchr(&dest, '`');
5565 add_till_backquote(&dest, input);
5567 o_addstr(&ctx.as_string, dest.data + pos);
5568 o_addchr(&ctx.as_string, '`');
5570 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5571 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5576 #if ENABLE_HUSH_CASE
5579 if (done_word(&dest, &ctx)) {
5582 done_pipe(&ctx, PIPE_SEQ);
5583 #if ENABLE_HUSH_CASE
5584 /* Eat multiple semicolons, detect
5585 * whether it means something special */
5590 ch = i_getch(input);
5591 nommu_addchr(&ctx.as_string, ch);
5592 if (ctx.ctx_res_w == RES_CASEI) {
5593 ctx.ctx_dsemicolon = 1;
5594 ctx.ctx_res_w = RES_MATCH;
5600 /* We just finished a cmd. New one may start
5601 * with an assignment */
5602 dest.o_assignment = MAYBE_ASSIGNMENT;
5605 if (done_word(&dest, &ctx)) {
5609 ch = i_getch(input);
5610 nommu_addchr(&ctx.as_string, ch);
5611 done_pipe(&ctx, PIPE_AND);
5613 done_pipe(&ctx, PIPE_BG);
5617 if (done_word(&dest, &ctx)) {
5620 #if ENABLE_HUSH_CASE
5621 if (ctx.ctx_res_w == RES_MATCH)
5622 break; /* we are in case's "word | word)" */
5624 if (next == '|') { /* || */
5625 ch = i_getch(input);
5626 nommu_addchr(&ctx.as_string, ch);
5627 done_pipe(&ctx, PIPE_OR);
5629 /* we could pick up a file descriptor choice here
5630 * with redirect_opt_num(), but bash doesn't do it.
5631 * "echo foo 2| cat" yields "foo 2". */
5636 #if ENABLE_HUSH_CASE
5637 /* "case... in [(]word)..." - skip '(' */
5638 if (ctx.ctx_res_w == RES_MATCH
5639 && ctx.command->argv == NULL /* not (word|(... */
5640 && dest.length == 0 /* not word(... */
5641 && dest.o_quoted == 0 /* not ""(... */
5647 if (parse_group(&dest, &ctx, input, ch) != 0) {
5652 #if ENABLE_HUSH_CASE
5653 if (ctx.ctx_res_w == RES_MATCH)
5657 /* proper use of this character is caught by end_trigger:
5658 * if we see {, we call parse_group(..., end_trigger='}')
5659 * and it will match } earlier (not here). */
5660 syntax_error_unexpected_ch(ch);
5664 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5670 struct parse_context *pctx;
5671 IF_HAS_KEYWORDS(struct parse_context *p2;)
5673 /* Clean up allocated tree.
5674 * Samples for finding leaks on syntax error recovery path.
5675 * Run them from interactive shell, watch pmap `pidof hush`.
5676 * while if false; then false; fi do break; done
5678 * while if false; then false; fi; do break; fi
5679 * Samples to catch leaks at execution:
5680 * while if (true | {true;}); then echo ok; fi; do break; done
5681 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5685 /* Update pipe/command counts,
5686 * otherwise freeing may miss some */
5687 done_pipe(pctx, PIPE_SEQ);
5688 debug_printf_clean("freeing list %p from ctx %p\n",
5689 pctx->list_head, pctx);
5690 debug_print_tree(pctx->list_head, 0);
5691 free_pipe_list(pctx->list_head);
5692 debug_printf_clean("freed list %p\n", pctx->list_head);
5694 o_free_unsafe(&pctx->as_string);
5696 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5700 IF_HAS_KEYWORDS(pctx = p2;)
5701 } while (HAS_KEYWORDS && pctx);
5702 /* Free text, clear all dest fields */
5704 /* If we are not in top-level parse, we return,
5705 * our caller will propagate error.
5707 if (end_trigger != ';') {
5715 /* Discard cached input, force prompt */
5717 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5722 /* Executing from string: eval, sh -c '...'
5723 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5724 * end_trigger controls how often we stop parsing
5725 * NUL: parse all, execute, return
5726 * ';': parse till ';' or newline, execute, repeat till EOF
5728 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5731 struct pipe *pipe_list;
5733 pipe_list = parse_stream(NULL, inp, end_trigger);
5734 if (!pipe_list) /* EOF */
5736 debug_print_tree(pipe_list, 0);
5737 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5738 run_and_free_list(pipe_list);
5742 static void parse_and_run_string(const char *s)
5744 struct in_str input;
5745 setup_string_in_str(&input, s);
5746 parse_and_run_stream(&input, '\0');
5749 static void parse_and_run_file(FILE *f)
5751 struct in_str input;
5752 setup_file_in_str(&input, f);
5753 parse_and_run_stream(&input, ';');
5756 /* Called a few times only (or even once if "sh -c") */
5757 static void block_signals(int second_time)
5762 mask = (1 << SIGQUIT);
5763 if (G_interactive_fd)
5764 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
5765 G.non_DFL_mask = mask;
5768 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5772 sigaddset(&G.blocked_set, sig);
5776 sigdelset(&G.blocked_set, SIGCHLD);
5778 sigprocmask(SIG_SETMASK, &G.blocked_set,
5779 second_time ? NULL : &G.inherited_set);
5780 /* POSIX allows shell to re-enable SIGCHLD
5781 * even if it was SIG_IGN on entry */
5782 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5784 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5789 static void maybe_set_to_sigexit(int sig)
5791 void (*handler)(int);
5792 /* non_DFL_mask'ed signals are, well, masked,
5793 * no need to set handler for them.
5795 if (!((G.non_DFL_mask >> sig) & 1)) {
5796 handler = signal(sig, sigexit);
5797 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5798 signal(sig, handler);
5801 /* Set handlers to restore tty pgrp and exit */
5802 static void set_fatal_handlers(void)
5804 /* We _must_ restore tty pgrp on fatal signals */
5806 maybe_set_to_sigexit(SIGILL );
5807 maybe_set_to_sigexit(SIGFPE );
5808 maybe_set_to_sigexit(SIGBUS );
5809 maybe_set_to_sigexit(SIGSEGV);
5810 maybe_set_to_sigexit(SIGTRAP);
5811 } /* else: hush is perfect. what SEGV? */
5812 maybe_set_to_sigexit(SIGABRT);
5813 /* bash 3.2 seems to handle these just like 'fatal' ones */
5814 maybe_set_to_sigexit(SIGPIPE);
5815 maybe_set_to_sigexit(SIGALRM);
5816 //TODO: disable and move down when proper SIGHUP handling is added
5817 maybe_set_to_sigexit(SIGHUP );
5818 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5819 * if we aren't interactive... but in this case
5820 * we never want to restore pgrp on exit, and this fn is not called */
5821 /*maybe_set_to_sigexit(SIGTERM);*/
5822 /*maybe_set_to_sigexit(SIGINT );*/
5826 static int set_mode(const char cstate, const char mode)
5828 int state = (cstate == '-' ? 1 : 0);
5830 case 'n': G.fake_mode = state; break;
5831 case 'x': /*G.debug_mode = state;*/ break;
5832 default: return EXIT_FAILURE;
5834 return EXIT_SUCCESS;
5837 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5838 int hush_main(int argc, char **argv)
5840 static const struct variable const_shell_ver = {
5842 .varstr = (char*)hush_version_str,
5843 .max_len = 1, /* 0 can provoke free(name) */
5847 int signal_mask_is_inited = 0;
5850 struct variable *cur_var;
5853 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5854 G.last_exitcode = EXIT_SUCCESS;
5856 G.argv0_for_re_execing = argv[0];
5858 /* Deal with HUSH_VERSION */
5859 G.shell_ver = const_shell_ver; /* copying struct here */
5860 G.top_var = &G.shell_ver;
5861 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5862 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5863 /* Initialize our shell local variables with the values
5864 * currently living in the environment */
5865 cur_var = G.top_var;
5868 char *value = strchr(*e, '=');
5869 if (value) { /* paranoia */
5870 cur_var->next = xzalloc(sizeof(*cur_var));
5871 cur_var = cur_var->next;
5872 cur_var->varstr = *e;
5873 cur_var->max_len = strlen(*e);
5874 cur_var->flg_export = 1;
5878 debug_printf_env("putenv '%s'\n", hush_version_str);
5879 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5880 #if ENABLE_FEATURE_EDITING
5881 G.line_input_state = new_line_input_t(FOR_SHELL);
5883 G.global_argc = argc;
5884 G.global_argv = argv;
5885 /* Initialize some more globals to non-zero values */
5887 #if ENABLE_HUSH_INTERACTIVE
5888 if (ENABLE_FEATURE_EDITING)
5889 cmdedit_set_initial_prompt();
5893 if (setjmp(die_jmp)) {
5894 /* xfunc has failed! die die die */
5895 /* no EXIT traps, this is an escape hatch! */
5897 hush_exit(xfunc_error_retval);
5900 /* Shell is non-interactive at first. We need to call
5901 * block_signals(0) if we are going to execute "sh <script>",
5902 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5903 * If we later decide that we are interactive, we run block_signals(0)
5904 * (or re-run block_signals(1) if we ran block_signals(0) before)
5905 * in order to intercept (more) signals.
5909 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5911 opt = getopt(argc, argv, "c:xins"
5914 # if ENABLE_HUSH_FUNCTIONS
5924 G.root_pid = getpid();
5925 G.global_argv = argv + optind;
5926 if (!argv[optind]) {
5927 /* -c 'script' (no params): prevent empty $0 */
5928 *--G.global_argv = argv[0];
5930 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5931 G.global_argc = argc - optind;
5932 block_signals(0); /* 0: called 1st time */
5933 parse_and_run_string(optarg);
5936 /* Well, we cannot just declare interactiveness,
5937 * we have to have some stuff (ctty, etc) */
5938 /* G_interactive_fd++; */
5941 /* "-s" means "read from stdin", but this is how we always
5942 * operate, so simply do nothing here. */
5945 case '<': /* "big heredoc" support */
5946 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5949 G.root_pid = bb_strtou(optarg, &optarg, 16);
5951 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5953 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5954 # if ENABLE_HUSH_LOOPS
5956 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5961 set_local_var(xstrdup(optarg), 0, opt == 'R');
5963 # if ENABLE_HUSH_FUNCTIONS
5965 struct function *funcp = new_function(optarg);
5966 /* funcp->name is already set to optarg */
5967 /* funcp->body is set to NULL. It's a special case. */
5968 funcp->body_as_string = argv[optind];
5976 if (!set_mode('-', opt))
5980 fprintf(stderr, "Usage: sh [FILE]...\n"
5981 " or: sh -c command [args]...\n\n");
5987 } /* option parsing loop */
5990 G.root_pid = getpid();
5992 /* If we are login shell... */
5993 if (argv[0] && argv[0][0] == '-') {
5995 /* XXX what should argv be while sourcing /etc/profile? */
5996 debug_printf("sourcing /etc/profile\n");
5997 input = fopen_for_read("/etc/profile");
5998 if (input != NULL) {
5999 close_on_exec_on(fileno(input));
6000 block_signals(0); /* 0: called 1st time */
6001 signal_mask_is_inited = 1;
6002 parse_and_run_file(input);
6005 /* bash: after sourcing /etc/profile,
6006 * tries to source (in the given order):
6007 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6008 * stopping of first found. --noprofile turns this off.
6009 * bash also sources ~/.bash_logout on exit.
6010 * If called as sh, skips .bash_XXX files.
6017 * "bash <script>" (which is never interactive (unless -i?))
6018 * sources $BASH_ENV here (without scanning $PATH).
6019 * If called as sh, does the same but with $ENV.
6021 debug_printf("running script '%s'\n", argv[optind]);
6022 G.global_argv = argv + optind;
6023 G.global_argc = argc - optind;
6024 input = xfopen_for_read(argv[optind]);
6025 close_on_exec_on(fileno(input));
6026 if (!signal_mask_is_inited)
6027 block_signals(0); /* 0: called 1st time */
6028 parse_and_run_file(input);
6029 #if ENABLE_FEATURE_CLEAN_UP
6035 /* Up to here, shell was non-interactive. Now it may become one.
6036 * NB: don't forget to (re)run block_signals(0/1) as needed.
6039 /* A shell is interactive if the '-i' flag was given, or if all of
6040 * the following conditions are met:
6042 * no arguments remaining or the -s flag given
6043 * standard input is a terminal
6044 * standard output is a terminal
6045 * Refer to Posix.2, the description of the 'sh' utility.
6048 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6049 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6050 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6051 //TODO: "interactive" and "have job control" are two different things.
6052 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6053 //should stay on! Currently, we mix these into one.
6054 if (G.saved_tty_pgrp >= 0) {
6055 /* try to dup stdin to high fd#, >= 255 */
6056 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6057 if (G_interactive_fd < 0) {
6058 /* try to dup to any fd */
6059 G_interactive_fd = dup(STDIN_FILENO);
6060 if (G_interactive_fd < 0)
6062 G_interactive_fd = 0;
6064 // TODO: track & disallow any attempts of user
6065 // to (inadvertently) close/redirect it
6068 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6069 if (G_interactive_fd) {
6072 /* We are indeed interactive shell, and we will perform
6073 * job control. Setting up for that. */
6075 close_on_exec_on(G_interactive_fd);
6076 /* If we were run as 'hush &', sleep until we are
6077 * in the foreground (tty pgrp == our pgrp).
6078 * If we get started under a job aware app (like bash),
6079 * make sure we are now in charge so we don't fight over
6080 * who gets the foreground */
6082 shell_pgrp = getpgrp();
6083 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6084 if (G.saved_tty_pgrp == shell_pgrp)
6086 /* send TTIN to ourself (should stop us) */
6087 kill(- shell_pgrp, SIGTTIN);
6089 /* Block some signals */
6090 block_signals(signal_mask_is_inited);
6091 /* Set other signals to restore saved_tty_pgrp */
6092 set_fatal_handlers();
6093 /* Put ourselves in our own process group */
6094 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6095 /* Grab control of the terminal */
6096 tcsetpgrp(G_interactive_fd, getpid());
6097 /* -1 is special - makes xfuncs longjmp, not exit
6098 * (we reset die_sleep = 0 whereever we [v]fork) */
6099 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6100 } else if (!signal_mask_is_inited) {
6101 block_signals(0); /* 0: called 1st time */
6102 } /* else: block_signals(0) was done before */
6103 #elif ENABLE_HUSH_INTERACTIVE
6104 /* No job control compiled in, only prompt/line editing */
6105 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6106 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6107 if (G_interactive_fd < 0) {
6108 /* try to dup to any fd */
6109 G_interactive_fd = dup(STDIN_FILENO);
6110 if (G_interactive_fd < 0)
6112 G_interactive_fd = 0;
6115 if (G_interactive_fd) {
6116 close_on_exec_on(G_interactive_fd);
6117 block_signals(signal_mask_is_inited);
6118 } else if (!signal_mask_is_inited) {
6122 /* We have interactiveness code disabled */
6123 if (!signal_mask_is_inited) {
6128 * if interactive but not a login shell, sources ~/.bashrc
6129 * (--norc turns this off, --rcfile <file> overrides)
6132 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6133 printf("\n\n%s hush - the humble shell\n", bb_banner);
6134 printf("Enter 'help' for a list of built-in commands.\n\n");
6137 parse_and_run_file(stdin);
6140 #if ENABLE_FEATURE_CLEAN_UP
6141 if (G.cwd != bb_msg_unknown)
6143 cur_var = G.top_var->next;
6145 struct variable *tmp = cur_var;
6146 if (!cur_var->max_len)
6147 free(cur_var->varstr);
6148 cur_var = cur_var->next;
6152 hush_exit(G.last_exitcode);
6157 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6158 int lash_main(int argc, char **argv)
6160 //bb_error_msg("lash is deprecated, please use hush instead");
6161 return hush_main(argc, argv);
6169 static int builtin_trap(char **argv)
6176 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6180 /* No args: print all trapped. This isn't 100% correct as we
6181 * should be escaping the cmd so that it can be pasted back in
6183 for (i = 0; i < NSIG; ++i)
6185 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
6186 return EXIT_SUCCESS;
6191 /* If first arg is decimal: reset all specified signals */
6192 sig = bb_strtou(*argv, NULL, 10);
6198 sig = get_signum(*argv++);
6199 if (sig < 0 || sig >= NSIG) {
6201 /* Mimic bash message exactly */
6202 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
6207 G.traps[sig] = xstrdup(new_cmd);
6209 debug_printf("trap: setting SIG%s (%i) to '%s'",
6210 get_signame(sig), sig, G.traps[sig]);
6212 /* There is no signal for 0 (EXIT) */
6217 sigaddset(&G.blocked_set, sig);
6219 /* There was a trap handler, we are removing it
6220 * (if sig has non-DFL handling,
6221 * we don't need to do anything) */
6222 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6224 sigdelset(&G.blocked_set, sig);
6226 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6231 /* First arg is "-": reset all specified to default */
6232 /* First arg is "": ignore all specified */
6233 /* Everything else: execute first arg upon signal */
6235 bb_error_msg("trap: invalid arguments");
6236 return EXIT_FAILURE;
6238 if (NOT_LONE_DASH(*argv))
6244 static int builtin_true(char **argv UNUSED_PARAM)
6249 static int builtin_test(char **argv)
6256 return test_main(argc, argv - argc);
6259 static int builtin_echo(char **argv)
6266 return echo_main(argc, argv - argc);
6269 static int builtin_eval(char **argv)
6271 int rcode = EXIT_SUCCESS;
6274 char *str = expand_strvec_to_string(argv);
6276 * eval "echo Hi; done" ("done" is syntax error):
6277 * "echo Hi" will not execute too.
6279 parse_and_run_string(str);
6281 rcode = G.last_exitcode;
6286 static int builtin_cd(char **argv)
6288 const char *newdir = argv[1];
6289 if (newdir == NULL) {
6290 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6291 * bash says "bash: cd: HOME not set" and does nothing
6294 newdir = getenv("HOME") ? : "/";
6296 if (chdir(newdir)) {
6297 /* Mimic bash message exactly */
6298 bb_perror_msg("cd: %s", newdir);
6299 return EXIT_FAILURE;
6302 return EXIT_SUCCESS;
6305 static int builtin_exec(char **argv)
6307 if (*++argv == NULL)
6308 return EXIT_SUCCESS; /* bash does this */
6313 // FIXME: if exec fails, bash does NOT exit! We do...
6314 pseudo_exec_argv(&dummy, argv, 0, NULL);
6319 static int builtin_exit(char **argv)
6321 debug_printf_exec("%s()\n", __func__);
6322 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6323 //puts("exit"); /* bash does it */
6324 // TODO: warn if we have background jobs: "There are stopped jobs"
6325 // On second consecutive 'exit', exit anyway.
6326 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6328 /* note: EXIT trap is run by hush_exit */
6329 if (*++argv == NULL)
6330 hush_exit(G.last_exitcode);
6331 /* mimic bash: exit 123abc == exit 255 + error msg */
6332 xfunc_error_retval = 255;
6333 /* bash: exit -2 == exit 254, no error msg */
6334 hush_exit(xatoi(*argv) & 0xff);
6337 static int builtin_export(char **argv)
6339 if (*++argv == NULL) {
6346 /* ash emits: export VAR='VAL'
6347 * bash: declare -x VAR="VAL"
6348 * we follow ash example */
6349 const char *s = *e++;
6350 const char *p = strchr(s, '=');
6352 if (!p) /* wtf? take next variable */
6355 printf("export %.*s", (int)(p - s) + 1, s);
6359 p = strchrnul(s, '\'');
6361 printf("'%.*s'", (int)(p - s), s);
6366 /* s points to '; print ''...'''" */
6368 do putchar('\''); while (*++s == '\'');
6376 return EXIT_SUCCESS;
6383 value = strchr(name, '=');
6385 /* They are exporting something without a =VALUE */
6386 struct variable *var;
6388 var = get_local_var(name);
6390 var->flg_export = 1;
6391 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6392 putenv(var->varstr);
6394 /* bash does not return an error when trying to export
6395 * an undefined variable. Do likewise. */
6398 set_local_var(xstrdup(name), 1, 0);
6401 return EXIT_SUCCESS;
6405 /* built-in 'fg' and 'bg' handler */
6406 static int builtin_fg_bg(char **argv)
6411 if (!G_interactive_fd)
6412 return EXIT_FAILURE;
6413 /* If they gave us no args, assume they want the last backgrounded task */
6415 for (pi = G.job_list; pi; pi = pi->next) {
6416 if (pi->jobid == G.last_jobid) {
6420 bb_error_msg("%s: no current job", argv[0]);
6421 return EXIT_FAILURE;
6423 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6424 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6425 return EXIT_FAILURE;
6427 for (pi = G.job_list; pi; pi = pi->next) {
6428 if (pi->jobid == jobnum) {
6432 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6433 return EXIT_FAILURE;
6435 // TODO: bash prints a string representation
6436 // of job being foregrounded (like "sleep 1 | cat")
6437 if (argv[0][0] == 'f') {
6438 /* Put the job into the foreground. */
6439 tcsetpgrp(G_interactive_fd, pi->pgrp);
6442 /* Restart the processes in the job */
6443 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6444 for (i = 0; i < pi->num_cmds; i++) {
6445 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6446 pi->cmds[i].is_stopped = 0;
6448 pi->stopped_cmds = 0;
6450 i = kill(- pi->pgrp, SIGCONT);
6452 if (errno == ESRCH) {
6453 delete_finished_bg_job(pi);
6454 return EXIT_SUCCESS;
6456 bb_perror_msg("kill (SIGCONT)");
6459 if (argv[0][0] == 'f') {
6461 return checkjobs_and_fg_shell(pi);
6463 return EXIT_SUCCESS;
6467 #if ENABLE_HUSH_HELP
6468 static int builtin_help(char **argv UNUSED_PARAM)
6470 const struct built_in_command *x;
6473 "Built-in commands:\n"
6474 "------------------\n");
6475 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6476 printf("%s\t%s\n", x->cmd, x->descr);
6479 return EXIT_SUCCESS;
6484 static int builtin_jobs(char **argv UNUSED_PARAM)
6487 const char *status_string;
6489 for (job = G.job_list; job; job = job->next) {
6490 if (job->alive_cmds == job->stopped_cmds)
6491 status_string = "Stopped";
6493 status_string = "Running";
6495 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6497 return EXIT_SUCCESS;
6502 static int builtin_memleak(char **argv UNUSED_PARAM)
6507 /* Crude attempt to find where "free memory" starts,
6508 * sans fragmentation. */
6510 l = (unsigned long)p;
6513 if (l < (unsigned long)p) l = (unsigned long)p;
6516 if (!G.memleak_value)
6517 G.memleak_value = l;
6519 l -= G.memleak_value;
6526 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6531 static int builtin_pwd(char **argv UNUSED_PARAM)
6534 return EXIT_SUCCESS;
6537 static int builtin_read(char **argv)
6540 const char *name = "REPLY";
6544 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6545 * and _after_ that_ it will complain */
6546 if (!is_well_formed_var_name(name, '\0')) {
6547 /* Mimic bash message */
6548 bb_error_msg("read: '%s': not a valid identifier", name);
6553 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6555 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6556 return set_local_var(string, 0, 0);
6559 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6560 * built-in 'set' handler
6562 * set [-abCefhmnuvx] [-o option] [argument...]
6563 * set [+abCefhmnuvx] [+o option] [argument...]
6564 * set -- [argument...]
6567 * Implementations shall support the options in both their hyphen and
6568 * plus-sign forms. These options can also be specified as options to sh.
6570 * Write out all variables and their values: set
6571 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6572 * Turn on the -x and -v options: set -xv
6573 * Unset all positional parameters: set --
6574 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6575 * Set the positional parameters to the expansion of x, even if x expands
6576 * with a leading '-' or '+': set -- $x
6578 * So far, we only support "set -- [argument...]" and some of the short names.
6580 static int builtin_set(char **argv)
6583 char **pp, **g_argv;
6584 char *arg = *++argv;
6588 for (e = G.top_var; e; e = e->next)
6590 return EXIT_SUCCESS;
6594 if (!strcmp(arg, "--")) {
6598 if (arg[0] != '+' && arg[0] != '-')
6600 for (n = 1; arg[n]; ++n)
6601 if (set_mode(arg[0], arg[n]))
6603 } while ((arg = *++argv) != NULL);
6604 /* Now argv[0] is 1st argument */
6607 return EXIT_SUCCESS;
6610 /* NB: G.global_argv[0] ($0) is never freed/changed */
6611 g_argv = G.global_argv;
6612 if (G.global_args_malloced) {
6618 G.global_args_malloced = 1;
6619 pp = xzalloc(sizeof(pp[0]) * 2);
6620 pp[0] = g_argv[0]; /* retain $0 */
6623 /* This realloc's G.global_argv */
6624 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6631 return EXIT_SUCCESS;
6633 /* Nothing known, so abort */
6635 bb_error_msg("set: %s: invalid option", arg);
6636 return EXIT_FAILURE;
6639 static int builtin_shift(char **argv)
6645 if (n >= 0 && n < G.global_argc) {
6646 if (G.global_args_malloced) {
6649 free(G.global_argv[m++]);
6652 memmove(&G.global_argv[1], &G.global_argv[n+1],
6653 G.global_argc * sizeof(G.global_argv[0]));
6654 return EXIT_SUCCESS;
6656 return EXIT_FAILURE;
6659 static int builtin_source(char **argv)
6663 if (*++argv == NULL)
6664 return EXIT_FAILURE;
6666 /* XXX search through $PATH is missing */
6667 input = fopen_or_warn(*argv, "r");
6669 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6670 return EXIT_FAILURE;
6672 close_on_exec_on(fileno(input));
6674 /* Now run the file */
6676 /* XXX argv and argc are broken; need to save old G.global_argv
6677 * (pointer only is OK!) on this stack frame,
6678 * set G.global_argv=argv+1, recurse, and restore. */
6679 parse_and_run_file(input);
6681 return G.last_exitcode;
6684 static int builtin_umask(char **argv)
6687 const char *arg = argv[1];
6689 //TODO: umask may take chmod-like symbolic masks
6690 new_umask = bb_strtou(arg, NULL, 8);
6692 //Message? bash examples:
6693 //bash: umask: 'q': invalid symbolic mode operator
6694 //bash: umask: 999: octal number out of range
6695 return EXIT_FAILURE;
6698 new_umask = umask(0);
6699 printf("%.3o\n", (unsigned) new_umask);
6700 /* fall through and restore new_umask which we set to 0 */
6703 return EXIT_SUCCESS;
6706 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6707 static int builtin_unset(char **argv)
6713 return EXIT_SUCCESS;
6716 if (argv[0][0] == '-') {
6717 switch (argv[0][1]) {
6723 bb_error_msg("unset: %s: invalid option", *argv);
6724 return EXIT_FAILURE;
6726 //TODO: disallow "unset -vf ..." too
6733 if (unset_local_var(*argv)) {
6734 /* unset <nonexistent_var> doesn't fail.
6735 * Error is when one tries to unset RO var.
6736 * Message was printed by unset_local_var. */
6740 //#if ENABLE_HUSH_FUNCTIONS
6742 // unset_local_func(*argv);
6750 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6751 static int builtin_wait(char **argv)
6753 int ret = EXIT_SUCCESS;
6756 if (*++argv == NULL) {
6757 /* Don't care about wait results */
6758 /* Note 1: must wait until there are no more children */
6759 /* Note 2: must be interruptible */
6761 * $ sleep 3 & sleep 6 & wait
6766 * $ sleep 3 & sleep 6 & wait
6770 * ^C <-- after ~4 sec from keyboard
6773 sigaddset(&G.blocked_set, SIGCHLD);
6774 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6777 if (errno == ECHILD)
6779 /* Wait for SIGCHLD or any other signal of interest */
6780 /* sigtimedwait with infinite timeout: */
6781 sig = sigwaitinfo(&G.blocked_set, NULL);
6783 sig = check_and_run_traps(sig);
6784 if (sig && sig != SIGCHLD) { /* see note 2 */
6790 sigdelset(&G.blocked_set, SIGCHLD);
6791 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6795 /* This is probably buggy wrt interruptible-ness */
6797 pid_t pid = bb_strtou(*argv, NULL, 10);
6799 /* mimic bash message */
6800 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6801 return EXIT_FAILURE;
6803 if (waitpid(pid, &status, 0) == pid) {
6804 if (WIFSIGNALED(status))
6805 ret = 128 + WTERMSIG(status);
6806 else if (WIFEXITED(status))
6807 ret = WEXITSTATUS(status);
6811 bb_perror_msg("wait %s", *argv);
6820 #if ENABLE_HUSH_LOOPS
6821 static int builtin_break(char **argv)
6823 if (G.depth_of_loop == 0) {
6824 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6825 return EXIT_SUCCESS; /* bash compat */
6827 G.flag_break_continue++; /* BC_BREAK = 1 */
6828 G.depth_break_continue = 1;
6830 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6831 if (errno || !G.depth_break_continue || argv[2]) {
6832 bb_error_msg("%s: bad arguments", argv[0]);
6833 G.flag_break_continue = BC_BREAK;
6834 G.depth_break_continue = UINT_MAX;
6837 if (G.depth_of_loop < G.depth_break_continue)
6838 G.depth_break_continue = G.depth_of_loop;
6839 return EXIT_SUCCESS;
6842 static int builtin_continue(char **argv)
6844 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6845 return builtin_break(argv);