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 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1028 // G.count_SIGCHLD++;
1031 static int check_and_run_traps(int sig)
1033 static const struct timespec zero_timespec = { 0, 0 };
1034 smalluint save_rcode;
1040 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1045 if (G.traps && G.traps[sig]) {
1046 if (G.traps[sig][0]) {
1047 /* We have user-defined handler */
1048 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1049 save_rcode = G.last_exitcode;
1052 G.last_exitcode = save_rcode;
1053 } /* else: "" trap, ignoring signal */
1056 /* not a trap: special action */
1059 // G.count_SIGCHLD++;
1068 default: /* ignored: */
1069 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1078 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1079 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1080 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1081 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1083 /* Restores tty foreground process group, and exits.
1084 * May be called as signal handler for fatal signal
1085 * (will faithfully resend signal to itself, producing correct exit state)
1086 * or called directly with -EXITCODE.
1087 * We also call it if xfunc is exiting. */
1088 static void sigexit(int sig) NORETURN;
1089 static void sigexit(int sig)
1091 /* Disable all signals: job control, SIGPIPE, etc. */
1092 sigprocmask_allsigs(SIG_BLOCK);
1094 /* Careful: we can end up here after [v]fork. Do not restore
1095 * tty pgrp then, only top-level shell process does that */
1096 if (G_interactive_fd && getpid() == G.root_pid)
1097 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1099 /* Not a signal, just exit */
1103 kill_myself_with_sig(sig); /* does not return */
1107 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1108 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1112 /* Restores tty foreground process group, and exits. */
1113 static void hush_exit(int exitcode) NORETURN;
1114 static void hush_exit(int exitcode)
1116 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1117 /* Prevent recursion:
1118 * trap "echo Hi; exit" EXIT; exit
1120 char *argv[] = { NULL, G.traps[0], NULL };
1128 fflush(NULL); /* flush all streams */
1129 sigexit(- (exitcode & 0xff));
1136 static const char *set_cwd(void)
1138 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1139 * we must not try to free(bb_msg_unknown) */
1140 if (G.cwd == bb_msg_unknown)
1142 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1144 G.cwd = bb_msg_unknown;
1149 /* Get/check local shell variables */
1150 static struct variable *get_local_var(const char *name)
1152 struct variable *cur;
1158 for (cur = G.top_var; cur; cur = cur->next) {
1159 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1165 static const char *get_local_var_value(const char *src)
1167 struct variable *var = get_local_var(src);
1169 return strchr(var->varstr, '=') + 1;
1173 /* str holds "NAME=VAL" and is expected to be malloced.
1174 * We take ownership of it.
1178 * -1: if NAME is set, leave export status alone
1179 * if NAME is not set, do not export
1180 * flg_read_only is set only when we handle -R var=val
1183 #define set_local_var(str, flg_export, flg_read_only) \
1184 set_local_var(str, flg_export)
1186 static int set_local_var(char *str, int flg_export, int flg_read_only)
1188 struct variable *cur;
1192 value = strchr(str, '=');
1193 if (!value) { /* not expected to ever happen? */
1198 name_len = value - str + 1; /* including '=' */
1199 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1201 if (strncmp(cur->varstr, str, name_len) != 0) {
1203 /* Bail out. Note that now cur points
1204 * to last var in linked list */
1210 /* We found an existing var with this name */
1212 if (cur->flg_read_only) {
1216 bb_error_msg("%s: readonly variable", str);
1220 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1221 unsetenv(str); /* just in case */
1223 if (strcmp(cur->varstr, str) == 0) {
1228 if (cur->max_len >= strlen(str)) {
1229 /* This one is from startup env, reuse space */
1230 strcpy(cur->varstr, str);
1233 /* max_len == 0 signifies "malloced" var, which we can
1234 * (and has to) free */
1238 goto set_str_and_exp;
1241 /* Not found - create next variable struct */
1242 cur->next = xzalloc(sizeof(*cur));
1248 cur->flg_read_only = flg_read_only;
1251 if (flg_export == 1)
1252 cur->flg_export = 1;
1253 if (cur->flg_export) {
1254 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1255 return putenv(cur->varstr);
1260 static int unset_local_var(const char *name)
1262 struct variable *cur;
1263 struct variable *prev = prev; /* for gcc */
1267 return EXIT_SUCCESS;
1268 name_len = strlen(name);
1271 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1272 if (cur->flg_read_only) {
1273 bb_error_msg("%s: readonly variable", name);
1274 return EXIT_FAILURE;
1276 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1277 * is ro, and we cannot reach this code on the 1st pass */
1278 prev->next = cur->next;
1279 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1280 bb_unsetenv(cur->varstr);
1284 return EXIT_SUCCESS;
1289 return EXIT_SUCCESS;
1292 #if ENABLE_SH_MATH_SUPPORT
1293 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1294 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1295 static char *endofname(const char *name)
1303 if (!is_in_name(*p))
1309 static void arith_set_local_var(const char *name, const char *val, int flags)
1311 /* arith code doesnt malloc space, so do it for it */
1312 char *var = xasprintf("%s=%s", name, val);
1313 set_local_var(var, flags, 0);
1321 static int static_get(struct in_str *i)
1330 static int static_peek(struct in_str *i)
1335 #if ENABLE_HUSH_INTERACTIVE
1337 static void cmdedit_set_initial_prompt(void)
1339 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1340 G.PS1 = getenv("PS1");
1347 static const char* setup_prompt_string(int promptmode)
1349 const char *prompt_str;
1350 debug_printf("setup_prompt_string %d ", promptmode);
1351 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1352 /* Set up the prompt */
1353 if (promptmode == 0) { /* PS1 */
1355 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1360 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1361 debug_printf("result '%s'\n", prompt_str);
1365 static void get_user_input(struct in_str *i)
1368 const char *prompt_str;
1370 prompt_str = setup_prompt_string(i->promptmode);
1371 #if ENABLE_FEATURE_EDITING
1372 /* Enable command line editing only while a command line
1373 * is actually being read */
1376 /* buglet: SIGINT will not make new prompt to appear _at once_,
1377 * only after <Enter>. (^C will work) */
1378 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1379 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1380 check_and_run_traps(0);
1381 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1382 i->eof_flag = (r < 0);
1383 if (i->eof_flag) { /* EOF/error detected */
1384 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1385 G.user_input_buf[1] = '\0';
1390 fputs(prompt_str, stdout);
1392 G.user_input_buf[0] = r = fgetc(i->file);
1393 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1394 //do we need check_and_run_traps(0)? (maybe only if stdin)
1395 } while (G.flag_SIGINT);
1396 i->eof_flag = (r == EOF);
1398 i->p = G.user_input_buf;
1401 #endif /* INTERACTIVE */
1403 /* This is the magic location that prints prompts
1404 * and gets data back from the user */
1405 static int file_get(struct in_str *i)
1409 /* If there is data waiting, eat it up */
1410 if (i->p && *i->p) {
1411 #if ENABLE_HUSH_INTERACTIVE
1415 if (i->eof_flag && !*i->p)
1417 /* note: ch is never NUL */
1419 /* need to double check i->file because we might be doing something
1420 * more complicated by now, like sourcing or substituting. */
1421 #if ENABLE_HUSH_INTERACTIVE
1422 if (G_interactive_fd && i->promptme && i->file == stdin) {
1425 } while (!*i->p); /* need non-empty line */
1426 i->promptmode = 1; /* PS2 */
1431 do ch = fgetc(i->file); while (ch == '\0');
1433 debug_printf("file_get: got '%c' %d\n", ch, ch);
1434 #if ENABLE_HUSH_INTERACTIVE
1441 /* All callers guarantee this routine will never
1442 * be used right after a newline, so prompting is not needed.
1444 static int file_peek(struct in_str *i)
1447 if (i->p && *i->p) {
1448 if (i->eof_flag && !i->p[1])
1451 /* note: ch is never NUL */
1453 do ch = fgetc(i->file); while (ch == '\0');
1454 i->eof_flag = (ch == EOF);
1455 i->peek_buf[0] = ch;
1456 i->peek_buf[1] = '\0';
1458 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1462 static void setup_file_in_str(struct in_str *i, FILE *f)
1464 i->peek = file_peek;
1466 #if ENABLE_HUSH_INTERACTIVE
1468 i->promptmode = 0; /* PS1 */
1474 static void setup_string_in_str(struct in_str *i, const char *s)
1476 i->peek = static_peek;
1477 i->get = static_get;
1478 #if ENABLE_HUSH_INTERACTIVE
1480 i->promptmode = 0; /* PS1 */
1490 #define B_CHUNK (32 * sizeof(char*))
1492 static void o_reset_to_empty_unquoted(o_string *o)
1500 static void o_free(o_string *o)
1503 memset(o, 0, sizeof(*o));
1506 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1511 static void o_grow_by(o_string *o, int len)
1513 if (o->length + len > o->maxlen) {
1514 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1515 o->data = xrealloc(o->data, 1 + o->maxlen);
1519 static void o_addchr(o_string *o, int ch)
1521 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1523 o->data[o->length] = ch;
1525 o->data[o->length] = '\0';
1528 static void o_addblock(o_string *o, const char *str, int len)
1531 memcpy(&o->data[o->length], str, len);
1533 o->data[o->length] = '\0';
1537 static void o_addstr(o_string *o, const char *str)
1539 o_addblock(o, str, strlen(str));
1541 static void nommu_addchr(o_string *o, int ch)
1547 #define nommu_addchr(o, str) ((void)0)
1550 static void o_addstr_with_NUL(o_string *o, const char *str)
1552 o_addblock(o, str, strlen(str) + 1);
1555 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1560 && (*str != '*' && *str != '?' && *str != '[')
1568 /* My analysis of quoting semantics tells me that state information
1569 * is associated with a destination, not a source.
1571 static void o_addqchr(o_string *o, int ch)
1574 char *found = strchr("*?[\\", ch);
1579 o->data[o->length] = '\\';
1582 o->data[o->length] = ch;
1584 o->data[o->length] = '\0';
1587 static void o_addQchr(o_string *o, int ch)
1590 if (o->o_escape && strchr("*?[\\", ch)) {
1592 o->data[o->length] = '\\';
1596 o->data[o->length] = ch;
1598 o->data[o->length] = '\0';
1601 static void o_addQstr(o_string *o, const char *str, int len)
1604 o_addblock(o, str, len);
1610 int ordinary_cnt = strcspn(str, "*?[\\");
1611 if (ordinary_cnt > len) /* paranoia */
1613 o_addblock(o, str, ordinary_cnt);
1614 if (ordinary_cnt == len)
1616 str += ordinary_cnt;
1617 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1621 if (ch) { /* it is necessarily one of "*?[\\" */
1623 o->data[o->length] = '\\';
1627 o->data[o->length] = ch;
1629 o->data[o->length] = '\0';
1633 /* A special kind of o_string for $VAR and `cmd` expansion.
1634 * It contains char* list[] at the beginning, which is grown in 16 element
1635 * increments. Actual string data starts at the next multiple of 16 * (char*).
1636 * list[i] contains an INDEX (int!) into this string data.
1637 * It means that if list[] needs to grow, data needs to be moved higher up
1638 * but list[i]'s need not be modified.
1639 * NB: remembering how many list[i]'s you have there is crucial.
1640 * o_finalize_list() operation post-processes this structure - calculates
1641 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1643 #if DEBUG_EXPAND || DEBUG_GLOB
1644 static void debug_print_list(const char *prefix, o_string *o, int n)
1646 char **list = (char**)o->data;
1647 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1651 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1652 prefix, list, n, string_start, o->length, o->maxlen);
1655 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1656 o->data + (int)list[i] + string_start,
1657 o->data + (int)list[i] + string_start);
1661 const char *p = o->data + (int)list[n - 1] + string_start;
1663 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1667 #define debug_print_list(prefix, o, n) ((void)0)
1670 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1671 * in list[n] so that it points past last stored byte so far.
1672 * It returns n+1. */
1673 static int o_save_ptr_helper(o_string *o, int n)
1675 char **list = (char**)o->data;
1679 if (!o->has_empty_slot) {
1680 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1681 string_len = o->length - string_start;
1682 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1683 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1684 /* list[n] points to string_start, make space for 16 more pointers */
1685 o->maxlen += 0x10 * sizeof(list[0]);
1686 o->data = xrealloc(o->data, o->maxlen + 1);
1687 list = (char**)o->data;
1688 memmove(list + n + 0x10, list + n, string_len);
1689 o->length += 0x10 * sizeof(list[0]);
1691 debug_printf_list("list[%d]=%d string_start=%d\n",
1692 n, string_len, string_start);
1695 /* We have empty slot at list[n], reuse without growth */
1696 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1697 string_len = o->length - string_start;
1698 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1699 n, string_len, string_start);
1700 o->has_empty_slot = 0;
1702 list[n] = (char*)(ptrdiff_t)string_len;
1706 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1707 static int o_get_last_ptr(o_string *o, int n)
1709 char **list = (char**)o->data;
1710 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1712 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1715 /* o_glob performs globbing on last list[], saving each result
1716 * as a new list[]. */
1717 static int o_glob(o_string *o, int n)
1723 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1725 return o_save_ptr_helper(o, n);
1726 pattern = o->data + o_get_last_ptr(o, n);
1727 debug_printf_glob("glob pattern '%s'\n", pattern);
1728 if (!glob_needed(pattern)) {
1730 o->length = unbackslash(pattern) - o->data;
1731 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1732 return o_save_ptr_helper(o, n);
1735 memset(&globdata, 0, sizeof(globdata));
1736 gr = glob(pattern, 0, NULL, &globdata);
1737 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1738 if (gr == GLOB_NOSPACE)
1739 bb_error_msg_and_die("out of memory during glob");
1740 if (gr == GLOB_NOMATCH) {
1741 globfree(&globdata);
1744 if (gr != 0) { /* GLOB_ABORTED ? */
1745 //TODO: testcase for bad glob pattern behavior
1746 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1748 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1749 char **argv = globdata.gl_pathv;
1750 o->length = pattern - o->data; /* "forget" pattern */
1752 o_addstr_with_NUL(o, *argv);
1753 n = o_save_ptr_helper(o, n);
1759 globfree(&globdata);
1761 debug_print_list("o_glob returning", o, n);
1765 /* If o->o_glob == 1, glob the string so far remembered.
1766 * Otherwise, just finish current list[] and start new */
1767 static int o_save_ptr(o_string *o, int n)
1769 if (o->o_glob) { /* if globbing is requested */
1770 /* If o->has_empty_slot, list[n] was already globbed
1771 * (if it was requested back then when it was filled)
1772 * so don't do that again! */
1773 if (!o->has_empty_slot)
1774 return o_glob(o, n); /* o_save_ptr_helper is inside */
1776 return o_save_ptr_helper(o, n);
1779 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1780 static char **o_finalize_list(o_string *o, int n)
1785 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1787 debug_print_list("finalized", o, n);
1788 debug_printf_expand("finalized n:%d\n", n);
1789 list = (char**)o->data;
1790 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1794 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1800 /* Expansion can recurse */
1801 #if ENABLE_HUSH_TICK
1802 static int process_command_subs(o_string *dest, const char *s);
1804 static char *expand_string_to_string(const char *str);
1806 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1807 parse_stream_dquoted(dest, input, dquote_end)
1809 static int parse_stream_dquoted(o_string *as_string,
1811 struct in_str *input,
1814 /* expand_strvec_to_strvec() takes a list of strings, expands
1815 * all variable references within and returns a pointer to
1816 * a list of expanded strings, possibly with larger number
1817 * of strings. (Think VAR="a b"; echo $VAR).
1818 * This new list is allocated as a single malloc block.
1819 * NULL-terminated list of char* pointers is at the beginning of it,
1820 * followed by strings themself.
1821 * Caller can deallocate entire list by single free(list). */
1823 /* Store given string, finalizing the word and starting new one whenever
1824 * we encounter IFS char(s). This is used for expanding variable values.
1825 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1826 static int expand_on_ifs(o_string *output, int n, const char *str)
1829 int word_len = strcspn(str, G.ifs);
1831 if (output->o_escape || !output->o_glob)
1832 o_addQstr(output, str, word_len);
1833 else /* protect backslashes against globbing up :) */
1834 o_addblock_duplicate_backslash(output, str, word_len);
1837 if (!*str) /* EOL - do not finalize word */
1839 o_addchr(output, '\0');
1840 debug_print_list("expand_on_ifs", output, n);
1841 n = o_save_ptr(output, n);
1842 str += strspn(str, G.ifs); /* skip ifs chars */
1844 debug_print_list("expand_on_ifs[1]", output, n);
1848 /* Helper to expand $((...)) and heredoc body. These act as if
1849 * they are in double quotes, with the exception that they are not :).
1850 * Just the rules are similar: "expand only $var and `cmd`"
1852 * Returns malloced string.
1853 * As an optimization, we return NULL if expansion is not needed.
1855 static char *expand_pseudo_dquoted(const char *str)
1858 struct in_str input;
1859 o_string dest = NULL_O_STRING;
1861 if (strchr(str, '$') == NULL
1862 #if ENABLE_HUSH_TICK
1863 && strchr(str, '`') == NULL
1869 /* We need to expand. Example:
1870 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1872 setup_string_in_str(&input, str);
1873 parse_stream_dquoted(NULL, &dest, &input, EOF);
1874 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1875 exp_str = expand_string_to_string(dest.data);
1876 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1877 o_free_unsafe(&dest);
1881 /* Expand all variable references in given string, adding words to list[]
1882 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1883 * to be filled). This routine is extremely tricky: has to deal with
1884 * variables/parameters with whitespace, $* and $@, and constructs like
1885 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1886 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1888 /* or_mask is either 0 (normal case) or 0x80
1889 * (expansion of right-hand side of assignment == 1-element expand.
1890 * It will also do no globbing, and thus we must not backslash-quote!) */
1892 char first_ch, ored_ch;
1900 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1901 debug_print_list("expand_vars_to_list", output, n);
1902 n = o_save_ptr(output, n);
1903 debug_print_list("expand_vars_to_list[0]", output, n);
1905 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1906 #if ENABLE_HUSH_TICK
1907 o_string subst_result = NULL_O_STRING;
1909 #if ENABLE_SH_MATH_SUPPORT
1910 char arith_buf[sizeof(arith_t)*3 + 2];
1912 o_addblock(output, arg, p - arg);
1913 debug_print_list("expand_vars_to_list[1]", output, n);
1915 p = strchr(p, SPECIAL_VAR_SYMBOL);
1917 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1918 /* "$@" is special. Even if quoted, it can still
1919 * expand to nothing (not even an empty string) */
1920 if ((first_ch & 0x7f) != '@')
1921 ored_ch |= first_ch;
1924 switch (first_ch & 0x7f) {
1925 /* Highest bit in first_ch indicates that var is double-quoted */
1927 val = utoa(G.root_pid);
1929 case '!': /* bg pid */
1930 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1932 case '?': /* exitcode */
1933 val = utoa(G.last_exitcode);
1935 case '#': /* argc */
1936 if (arg[1] != SPECIAL_VAR_SYMBOL)
1937 /* actually, it's a ${#var} */
1939 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1944 if (!G.global_argv[i])
1946 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1947 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1948 smallint sv = output->o_escape;
1949 /* unquoted var's contents should be globbed, so don't escape */
1950 output->o_escape = 0;
1951 while (G.global_argv[i]) {
1952 n = expand_on_ifs(output, n, G.global_argv[i]);
1953 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1954 if (G.global_argv[i++][0] && G.global_argv[i]) {
1955 /* this argv[] is not empty and not last:
1956 * put terminating NUL, start new word */
1957 o_addchr(output, '\0');
1958 debug_print_list("expand_vars_to_list[2]", output, n);
1959 n = o_save_ptr(output, n);
1960 debug_print_list("expand_vars_to_list[3]", output, n);
1963 output->o_escape = sv;
1965 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1966 * and in this case should treat it like '$*' - see 'else...' below */
1967 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1969 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1970 if (++i >= G.global_argc)
1972 o_addchr(output, '\0');
1973 debug_print_list("expand_vars_to_list[4]", output, n);
1974 n = o_save_ptr(output, n);
1976 } else { /* quoted $*: add as one word */
1978 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1979 if (!G.global_argv[++i])
1982 o_addchr(output, G.ifs[0]);
1986 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1987 /* "Empty variable", used to make "" etc to not disappear */
1991 #if ENABLE_HUSH_TICK
1992 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1995 //TODO: can we just stuff it into "output" directly?
1996 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1997 process_command_subs(&subst_result, arg);
1998 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1999 val = subst_result.data;
2002 #if ENABLE_SH_MATH_SUPPORT
2003 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2004 arith_eval_hooks_t hooks;
2009 arg++; /* skip '+' */
2010 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2011 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2013 exp_str = expand_pseudo_dquoted(arg);
2014 hooks.lookupvar = get_local_var_value;
2015 hooks.setvar = arith_set_local_var;
2016 hooks.endofname = endofname;
2017 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2021 const char *msg = "error in arithmetic";
2024 msg = "exponent less than 0";
2027 msg = "divide by 0";
2030 msg = "expression recursion loop detected";
2035 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2036 sprintf(arith_buf, arith_t_fmt, res);
2041 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2043 bool exp_len = false;
2044 bool exp_null = false;
2046 char exp_save = exp_save; /* for compiler */
2047 char exp_op = exp_op; /* for compiler */
2048 char *exp_word = exp_word; /* for compiler */
2052 arg[0] = first_ch & 0x7f;
2054 /* prepare for expansions */
2055 if (var[0] == '#') {
2056 /* handle length expansion ${#var} */
2060 /* maybe handle parameter expansion */
2061 exp_off = strcspn(var, ":-=+?%#");
2065 exp_save = var[exp_off];
2066 exp_null = exp_save == ':';
2067 exp_word = var + exp_off;
2070 exp_op = *exp_word++;
2071 var[exp_off] = '\0';
2075 /* lookup the variable in question */
2076 if (isdigit(var[0])) {
2077 /* handle_dollar() should have vetted var for us */
2079 if (i < G.global_argc)
2080 val = G.global_argv[i];
2081 /* else val remains NULL: $N with too big N */
2083 val = get_local_var_value(var);
2085 /* handle any expansions */
2087 debug_printf_expand("expand: length of '%s' = ", val);
2088 val = utoa(val ? strlen(val) : 0);
2089 debug_printf_expand("%s\n", val);
2090 } else if (exp_off) {
2091 if (exp_op == '%' || exp_op == '#') {
2093 /* we need to do a pattern match */
2096 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2097 if (exp_op == *exp_word) /* ## or %% */
2099 val = dyn_val = xstrdup(val);
2100 loc = scan(dyn_val, exp_word, zero);
2107 /* we need to do an expansion */
2108 int exp_test = (!val || (exp_null && !val[0]));
2110 exp_test = !exp_test;
2111 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2112 exp_null ? "true" : "false", exp_test);
2114 if (exp_op == '?') {
2115 //TODO: how interactive bash aborts expansion mid-command?
2116 /* ${var?[error_msg_if_unset]} */
2117 /* ${var:?[error_msg_if_unset_or_null]} */
2118 /* mimic bash message */
2119 die_if_script("%s: %s",
2121 exp_word[0] ? exp_word : "parameter null or not set"
2127 if (exp_op == '=') {
2128 /* ${var=[word]} or ${var:=[word]} */
2129 if (isdigit(var[0]) || var[0] == '#') {
2130 /* mimic bash message */
2131 die_if_script("$%s: cannot assign in this way", var);
2134 char *new_var = xasprintf("%s=%s", var, val);
2135 set_local_var(new_var, -1, 0);
2141 var[exp_off] = exp_save;
2145 #if ENABLE_HUSH_TICK
2148 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2149 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2151 /* unquoted var's contents should be globbed, so don't escape */
2152 smallint sv = output->o_escape;
2153 output->o_escape = 0;
2154 n = expand_on_ifs(output, n, val);
2156 output->o_escape = sv;
2158 } else { /* quoted $VAR, val will be appended below */
2159 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2162 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2164 o_addQstr(output, val, strlen(val));
2168 /* Do the check to avoid writing to a const string */
2169 if (*p != SPECIAL_VAR_SYMBOL)
2170 *p = SPECIAL_VAR_SYMBOL;
2172 #if ENABLE_HUSH_TICK
2173 o_free(&subst_result);
2176 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2179 debug_print_list("expand_vars_to_list[a]", output, n);
2180 /* this part is literal, and it was already pre-quoted
2181 * if needed (much earlier), do not use o_addQstr here! */
2182 o_addstr_with_NUL(output, arg);
2183 debug_print_list("expand_vars_to_list[b]", output, n);
2184 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2185 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2188 /* allow to reuse list[n] later without re-growth */
2189 output->has_empty_slot = 1;
2191 o_addchr(output, '\0');
2196 static char **expand_variables(char **argv, int or_mask)
2201 o_string output = NULL_O_STRING;
2203 if (or_mask & 0x100) {
2204 output.o_escape = 1; /* protect against globbing for "$var" */
2205 /* (unquoted $var will temporarily switch it off) */
2212 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2215 debug_print_list("expand_variables", &output, n);
2217 /* output.data (malloced in one block) gets returned in "list" */
2218 list = o_finalize_list(&output, n);
2219 debug_print_strings("expand_variables[1]", list);
2223 static char **expand_strvec_to_strvec(char **argv)
2225 return expand_variables(argv, 0x100);
2228 /* Used for expansion of right hand of assignments */
2229 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2231 static char *expand_string_to_string(const char *str)
2233 char *argv[2], **list;
2235 argv[0] = (char*)str;
2237 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2239 if (!list[0] || list[1])
2240 bb_error_msg_and_die("BUG in varexp2");
2241 /* actually, just move string 2*sizeof(char*) bytes back */
2242 overlapping_strcpy((char*)list, list[0]);
2243 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2247 /* Used for "eval" builtin */
2248 static char* expand_strvec_to_string(char **argv)
2252 list = expand_variables(argv, 0x80);
2253 /* Convert all NULs to spaces */
2258 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2259 bb_error_msg_and_die("BUG in varexp3");
2260 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2264 overlapping_strcpy((char*)list, list[0]);
2265 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2269 static char **expand_assignments(char **argv, int count)
2273 /* Expand assignments into one string each */
2274 for (i = 0; i < count; i++) {
2275 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2283 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2285 static void reset_traps_to_defaults(void)
2288 JOBSIGS = (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
2292 if (!G.traps && !(G.non_DFL_mask & JOBSIGS))
2295 /* This function is always called in a child shell.
2296 * Child shells are not interactive.
2297 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2298 * Testcase: (while :; do :; done) + ^Z should background.
2300 G.non_DFL_mask &= ~JOBSIGS;
2301 sigdelset(&G.blocked_set, SIGTTIN);
2302 sigdelset(&G.blocked_set, SIGTTOU);
2303 sigdelset(&G.blocked_set, SIGTSTP);
2305 if (G.traps) for (sig = 0; sig < NSIG; sig++) {
2306 if (!G.traps[sig]) {
2310 G.traps[sig] = NULL;
2311 /* There is no signal for 0 (EXIT) */
2314 /* there was a trap handler, we are removing it
2315 * (if sig has non-DFL handling,
2316 * we don't need to do anything) */
2317 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2319 sigdelset(&G.blocked_set, sig);
2321 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2326 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2327 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2329 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2330 char *heredoc_argv[4];
2331 struct variable *cur;
2332 #if ENABLE_HUSH_FUNCTIONS
2333 struct function *funcp;
2338 if (!g_argv0) { /* heredoc */
2339 argv = heredoc_argv;
2340 argv[0] = (char *) G.argv0_for_re_execing;
2341 argv[1] = (char *) "-<";
2342 argv[2] = (char *) s;
2344 pp = &argv[3]; /* used as pointer to empty environment */
2348 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2349 , (unsigned) G.root_pid
2350 , (unsigned) G.last_bg_pid
2351 , (unsigned) G.last_exitcode
2352 USE_HUSH_LOOPS(, G.depth_of_loop)
2354 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2355 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2358 for (cur = G.top_var; cur; cur = cur->next) {
2359 if (!cur->flg_export || cur->flg_read_only)
2362 #if ENABLE_HUSH_FUNCTIONS
2363 for (funcp = G.top_func; funcp; funcp = funcp->next)
2369 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2370 *pp++ = (char *) G.argv0_for_re_execing;
2372 for (cur = G.top_var; cur; cur = cur->next) {
2373 if (cur->varstr == hush_version_str)
2375 if (cur->flg_read_only) {
2376 *pp++ = (char *) "-R";
2377 *pp++ = cur->varstr;
2378 } else if (!cur->flg_export) {
2379 *pp++ = (char *) "-V";
2380 *pp++ = cur->varstr;
2383 #if ENABLE_HUSH_FUNCTIONS
2384 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2385 *pp++ = (char *) "-F";
2386 *pp++ = funcp->name;
2387 *pp++ = funcp->body_as_string;
2390 /* We can pass activated traps here. Say, -Tnn:trap_string
2392 * However, POSIX says that subshells reset signals with traps
2394 * I tested bash-3.2 and it not only does that with true subshells
2395 * of the form ( list ), but with any forked children shells.
2396 * I set trap "echo W" WINCH; and then tried:
2398 * { echo 1; sleep 20; echo 2; } &
2399 * while true; do echo 1; sleep 20; echo 2; break; done &
2400 * true | { echo 1; sleep 20; echo 2; } | cat
2402 * In all these cases sending SIGWINCH to the child shell
2403 * did not run the trap. If I add trap "echo V" WINCH;
2404 * _inside_ group (just before echo 1), it works.
2406 * I conclude it means we don't need to pass active traps here.
2407 * exec syscall below resets them to SIG_DFL for us.
2409 *pp++ = (char *) "-c";
2414 /* *pp = NULL; - is already there */
2418 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2419 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2420 execve(bb_busybox_exec_path, argv, pp);
2421 /* Fallback. Useful for init=/bin/hush usage etc */
2422 if (argv[0][0] == '/')
2423 execve(argv[0], argv, pp);
2424 xfunc_error_retval = 127;
2425 bb_error_msg_and_die("can't re-execute the shell");
2427 #endif /* !BB_MMU */
2430 static void setup_heredoc(struct redir_struct *redir)
2432 struct fd_pair pair;
2435 /* the _body_ of heredoc (misleading field name) */
2436 const char *heredoc = redir->rd_filename;
2443 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2444 expanded = expand_pseudo_dquoted(heredoc);
2448 len = strlen(heredoc);
2450 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2452 xmove_fd(pair.rd, redir->rd_fd);
2454 /* Try writing without forking. Newer kernels have
2455 * dynamically growing pipes. Must use non-blocking write! */
2458 written = write(pair.wr, heredoc, len);
2469 ndelay_off(pair.wr);
2471 /* Okay, pipe buffer was not big enough */
2472 /* Note: we must not create a stray child (bastard? :)
2473 * for the unsuspecting parent process. Child creates a grandchild
2474 * and exits before parent execs the process which consumes heredoc
2475 * (that exec happens after we return from this function) */
2481 bb_perror_msg_and_die("vfork");
2484 disable_restore_tty_pgrp_on_exit();
2485 pid = BB_MMU ? fork() : vfork();
2487 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2491 close(redir->rd_fd); /* read side of the pipe */
2493 full_write(pair.wr, heredoc, len); /* may loop or block */
2496 /* Delegate blocking writes to another process */
2497 xmove_fd(pair.wr, STDOUT_FILENO);
2498 re_execute_shell(&to_free, heredoc, NULL, NULL);
2502 enable_restore_tty_pgrp_on_exit();
2508 wait(NULL); /* wait till child has died */
2511 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2512 * and stderr if they are redirected. */
2513 static int setup_redirects(struct command *prog, int squirrel[])
2516 struct redir_struct *redir;
2518 for (redir = prog->redirects; redir; redir = redir->next) {
2519 if (redir->rd_type == REDIRECT_HEREDOC2) {
2520 /* rd_fd<<HERE case */
2521 if (squirrel && redir->rd_fd < 3) {
2522 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2524 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2526 debug_printf_parse("set heredoc '%s'\n",
2527 redir->rd_filename);
2528 setup_heredoc(redir);
2532 if (redir->rd_dup == REDIRFD_TO_FILE) {
2533 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2535 if (redir->rd_filename == NULL) {
2536 /* Something went wrong in the parse.
2537 * Pretend it didn't happen */
2538 bb_error_msg("bug in redirect parse");
2541 mode = redir_table[redir->rd_type].mode;
2542 p = expand_string_to_string(redir->rd_filename);
2543 openfd = open_or_warn(p, mode);
2546 /* this could get lost if stderr has been redirected, but
2547 * bash and ash both lose it as well (though zsh doesn't!) */
2548 //what the above comment tries to say?
2552 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2553 openfd = redir->rd_dup;
2556 if (openfd != redir->rd_fd) {
2557 if (squirrel && redir->rd_fd < 3) {
2558 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2560 if (openfd == REDIRFD_CLOSE) {
2561 /* "n>-" means "close me" */
2562 close(redir->rd_fd);
2564 xdup2(openfd, redir->rd_fd);
2565 if (redir->rd_dup == REDIRFD_TO_FILE)
2573 static void restore_redirects(int squirrel[])
2576 for (i = 0; i < 3; i++) {
2579 /* We simply die on error */
2586 static void free_pipe_list(struct pipe *head);
2588 /* Return code is the exit status of the pipe */
2589 static void free_pipe(struct pipe *pi)
2592 struct command *command;
2593 struct redir_struct *r, *rnext;
2596 if (pi->stopped_cmds > 0) /* why? */
2598 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2599 for (i = 0; i < pi->num_cmds; i++) {
2600 command = &pi->cmds[i];
2601 debug_printf_clean(" command %d:\n", i);
2602 if (command->argv) {
2603 for (a = 0, p = command->argv; *p; a++, p++) {
2604 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2606 free_strings(command->argv);
2607 command->argv = NULL;
2609 /* not "else if": on syntax error, we may have both! */
2610 if (command->group) {
2611 debug_printf_clean(" begin group (grp_type:%d)\n",
2613 free_pipe_list(command->group);
2614 debug_printf_clean(" end group\n");
2615 command->group = NULL;
2617 /* else is crucial here.
2618 * If group != NULL, child_func is meaningless */
2619 #if ENABLE_HUSH_FUNCTIONS
2620 else if (command->child_func) {
2621 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2622 command->child_func->parent_cmd = NULL;
2626 free(command->group_as_string);
2627 command->group_as_string = NULL;
2629 for (r = command->redirects; r; r = rnext) {
2630 debug_printf_clean(" redirect %d%s",
2631 r->rd_fd, redir_table[r->rd_type].descrip);
2632 /* guard against the case >$FOO, where foo is unset or blank */
2633 if (r->rd_filename) {
2634 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2635 free(r->rd_filename);
2636 r->rd_filename = NULL;
2638 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2642 command->redirects = NULL;
2644 free(pi->cmds); /* children are an array, they get freed all at once */
2652 static void free_pipe_list(struct pipe *head)
2654 struct pipe *pi, *next;
2656 for (pi = head; pi; pi = next) {
2658 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2661 debug_printf_clean("pipe followup code %d\n", pi->followup);
2663 /*pi->next = NULL;*/
2669 static int run_list(struct pipe *pi);
2671 #define parse_stream(pstring, input, end_trigger) \
2672 parse_stream(input, end_trigger)
2674 static struct pipe *parse_stream(char **pstring,
2675 struct in_str *input,
2677 static void parse_and_run_string(const char *s);
2680 static const struct built_in_command* find_builtin(const char *name)
2682 const struct built_in_command *x;
2683 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2684 if (strcmp(name, x->cmd) != 0)
2686 debug_printf_exec("found builtin '%s'\n", name);
2692 #if ENABLE_HUSH_FUNCTIONS
2693 static const struct function *find_function(const char *name)
2695 const struct function *funcp = G.top_func;
2697 if (strcmp(name, funcp->name) == 0) {
2700 funcp = funcp->next;
2702 debug_printf_exec("found function '%s'\n", name);
2706 /* Note: takes ownership on name ptr */
2707 static struct function *new_function(char *name)
2709 struct function *funcp;
2710 struct function **funcpp = &G.top_func;
2712 while ((funcp = *funcpp) != NULL) {
2713 struct command *cmd;
2715 if (strcmp(funcp->name, name) != 0) {
2716 funcpp = &funcp->next;
2720 cmd = funcp->parent_cmd;
2721 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2723 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2725 /* Note: if !funcp->body, do not free body_as_string!
2726 * This is a special case of "-F name body" function:
2727 * body_as_string was not malloced! */
2729 free_pipe_list(funcp->body);
2731 free(funcp->body_as_string);
2735 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2736 cmd->argv[0] = funcp->name;
2737 cmd->group = funcp->body;
2739 cmd->group_as_string = funcp->body_as_string;
2744 debug_printf_exec("remembering new function '%s'\n", command->argv[0]);
2745 funcp = *funcpp = xzalloc(sizeof(*funcp));
2746 /*funcp->next = NULL;*/
2753 #define exec_function(nommu_save, funcp, argv) \
2754 exec_function(funcp, argv)
2756 static void exec_function(nommu_save_t *nommu_save,
2757 const struct function *funcp,
2758 char **argv) NORETURN;
2759 static void exec_function(nommu_save_t *nommu_save,
2760 const struct function *funcp,
2766 argv[0] = G.global_argv[0];
2767 G.global_argv = argv;
2771 /* On MMU, funcp->body is always non-NULL */
2772 n = run_list(funcp->body);
2776 re_execute_shell(&nommu_save->argv_from_re_execing,
2777 funcp->body_as_string,
2783 static int run_function(const struct function *funcp, char **argv)
2788 smallint sv_g_malloced;
2793 sv_g_malloced = G.global_args_malloced;
2794 sv_g_argc = G.global_argc;
2795 sv_g_argv = G.global_argv;
2802 argv[0] = G.global_argv[0]; /* retain $0 */
2803 G.global_args_malloced = 0;
2805 G.global_argv = argv;
2807 /* On MMU, funcp->body is always non-NULL */
2810 /* Function defined by -F */
2811 parse_and_run_string(funcp->body_as_string);
2812 n = G.last_exitcode;
2816 n = run_list(funcp->body);
2819 if (G.global_args_malloced) {
2820 /* function ran "set -- arg1 arg2 ..." */
2824 free(G.global_argv);
2828 G.global_args_malloced = sv_g_malloced;
2829 G.global_argc = sv_g_argc;
2830 G.global_argv = sv_g_argv;
2838 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2839 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2840 #define pseudo_exec(nommu_save, command, argv_expanded) \
2841 pseudo_exec(command, argv_expanded)
2844 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2846 * XXX no exit() here. If you don't exec, use _exit instead.
2847 * The at_exit handlers apparently confuse the calling process,
2848 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2849 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2850 char **argv, int assignment_cnt,
2851 char **argv_expanded) NORETURN;
2852 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2853 char **argv, int assignment_cnt,
2854 char **argv_expanded)
2858 /* Case when we are here: ... | var=val | ... */
2859 if (!argv[assignment_cnt])
2860 _exit(EXIT_SUCCESS);
2862 new_env = expand_assignments(argv, assignment_cnt);
2864 putenv_all(new_env);
2865 free(new_env); /* optional */
2867 nommu_save->new_env = new_env;
2868 nommu_save->old_env = putenv_all_and_save_old(new_env);
2870 if (argv_expanded) {
2871 argv = argv_expanded;
2873 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2875 nommu_save->argv = argv;
2879 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2880 if (strchr(argv[0], '/') != NULL)
2884 /* On NOMMU, we must never block!
2885 * Example: { sleep 99999 | read line } & echo Ok
2886 * read builtin will block on read syscall, leaving parent blocked
2887 * in vfork. Therefore we can't do this:
2890 /* Check if the command matches any of the builtins.
2891 * Depending on context, this might be redundant. But it's
2892 * easier to waste a few CPU cycles than it is to figure out
2893 * if this is one of those cases.
2897 const struct built_in_command *x = find_builtin(argv[0]);
2899 rcode = x->function(argv);
2905 #if ENABLE_HUSH_FUNCTIONS
2906 /* Check if the command matches any functions */
2908 const struct function *funcp = find_function(argv[0]);
2910 exec_function(nommu_save, funcp, argv);
2915 #if ENABLE_FEATURE_SH_STANDALONE
2916 /* Check if the command matches any busybox applets */
2918 int a = find_applet_by_name(argv[0]);
2920 # if BB_MMU /* see above why on NOMMU it is not allowed */
2921 if (APPLET_IS_NOEXEC(a)) {
2922 debug_printf_exec("running applet '%s'\n", argv[0]);
2923 run_applet_no_and_exit(a, argv);
2926 /* Re-exec ourselves */
2927 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2928 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2929 execv(bb_busybox_exec_path, argv);
2930 /* If they called chroot or otherwise made the binary no longer
2931 * executable, fall through */
2936 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2939 debug_printf_exec("execing '%s'\n", argv[0]);
2940 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2941 execvp(argv[0], argv);
2942 bb_perror_msg("can't exec '%s'", argv[0]);
2943 _exit(EXIT_FAILURE);
2946 /* Called after [v]fork() in run_pipe
2948 static void pseudo_exec(nommu_save_t *nommu_save,
2949 struct command *command,
2950 char **argv_expanded) NORETURN;
2951 static void pseudo_exec(nommu_save_t *nommu_save,
2952 struct command *command,
2953 char **argv_expanded)
2955 if (command->argv) {
2956 pseudo_exec_argv(nommu_save, command->argv,
2957 command->assignment_cnt, argv_expanded);
2960 if (command->group) {
2961 /* Cases when we are here:
2964 * ... | ( list ) | ...
2965 * ... | { list } | ...
2969 debug_printf_exec("pseudo_exec: run_list\n");
2970 reset_traps_to_defaults();
2971 rcode = run_list(command->group);
2972 /* OK to leak memory by not calling free_pipe_list,
2973 * since this process is about to exit */
2976 re_execute_shell(&nommu_save->argv_from_re_execing,
2977 command->group_as_string,
2983 /* Case when we are here: ... | >file */
2984 debug_printf_exec("pseudo_exec'ed null command\n");
2985 _exit(EXIT_SUCCESS);
2989 static const char *get_cmdtext(struct pipe *pi)
2995 /* This is subtle. ->cmdtext is created only on first backgrounding.
2996 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2997 * On subsequent bg argv is trashed, but we won't use it */
3000 argv = pi->cmds[0].argv;
3001 if (!argv || !argv[0]) {
3002 pi->cmdtext = xzalloc(1);
3007 do len += strlen(*argv) + 1; while (*++argv);
3008 pi->cmdtext = p = xmalloc(len);
3009 argv = pi->cmds[0].argv;
3011 len = strlen(*argv);
3012 memcpy(p, *argv, len);
3020 static void insert_bg_job(struct pipe *pi)
3022 struct pipe *thejob;
3025 /* Linear search for the ID of the job to use */
3027 for (thejob = G.job_list; thejob; thejob = thejob->next)
3028 if (thejob->jobid >= pi->jobid)
3029 pi->jobid = thejob->jobid + 1;
3031 /* Add thejob to the list of running jobs */
3033 thejob = G.job_list = xmalloc(sizeof(*thejob));
3035 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
3037 thejob->next = xmalloc(sizeof(*thejob));
3038 thejob = thejob->next;
3041 /* Physically copy the struct job */
3042 memcpy(thejob, pi, sizeof(struct pipe));
3043 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3044 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
3045 for (i = 0; i < pi->num_cmds; i++) {
3046 // TODO: do we really need to have so many fields which are just dead weight
3047 // at execution stage?
3048 thejob->cmds[i].pid = pi->cmds[i].pid;
3049 /* all other fields are not used and stay zero */
3051 thejob->next = NULL;
3052 thejob->cmdtext = xstrdup(get_cmdtext(pi));
3054 /* We don't wait for background thejobs to return -- append it
3055 to the list of backgrounded thejobs and leave it alone */
3056 if (G_interactive_fd)
3057 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
3058 G.last_bg_pid = thejob->cmds[0].pid;
3059 G.last_jobid = thejob->jobid;
3062 static void remove_bg_job(struct pipe *pi)
3064 struct pipe *prev_pipe;
3066 if (pi == G.job_list) {
3067 G.job_list = pi->next;
3069 prev_pipe = G.job_list;
3070 while (prev_pipe->next != pi)
3071 prev_pipe = prev_pipe->next;
3072 prev_pipe->next = pi->next;
3075 G.last_jobid = G.job_list->jobid;
3080 /* Remove a backgrounded job */
3081 static void delete_finished_bg_job(struct pipe *pi)
3084 pi->stopped_cmds = 0;
3090 /* Check to see if any processes have exited -- if they
3091 * have, figure out why and see if a job has completed */
3092 static int checkjobs(struct pipe* fg_pipe)
3102 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3105 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3106 // /* avoid doing syscall, nothing there anyway */
3109 attributes = WUNTRACED;
3110 if (fg_pipe == NULL)
3111 attributes |= WNOHANG;
3113 /* Do we do this right?
3114 * bash-3.00# sleep 20 | false
3116 * [3]+ Stopped sleep 20 | false
3117 * bash-3.00# echo $?
3118 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3121 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
3122 //are stopped. Testcase: "cat | cat" in a script (not on command line)
3123 // + killall -STOP cat
3130 // i = G.count_SIGCHLD;
3131 childpid = waitpid(-1, &status, attributes);
3132 if (childpid <= 0) {
3133 if (childpid && errno != ECHILD)
3134 bb_perror_msg("waitpid");
3135 // else /* Until next SIGCHLD, waitpid's are useless */
3136 // G.handled_SIGCHLD = i;
3139 dead = WIFEXITED(status) || WIFSIGNALED(status);
3142 if (WIFSTOPPED(status))
3143 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3144 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3145 if (WIFSIGNALED(status))
3146 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3147 childpid, WTERMSIG(status), WEXITSTATUS(status));
3148 if (WIFEXITED(status))
3149 debug_printf_jobs("pid %d exited, exitcode %d\n",
3150 childpid, WEXITSTATUS(status));
3152 /* Were we asked to wait for fg pipe? */
3154 for (i = 0; i < fg_pipe->num_cmds; i++) {
3155 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3156 if (fg_pipe->cmds[i].pid != childpid)
3158 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
3160 fg_pipe->cmds[i].pid = 0;
3161 fg_pipe->alive_cmds--;
3162 if (i == fg_pipe->num_cmds - 1) {
3163 /* last process gives overall exitstatus */
3164 rcode = WEXITSTATUS(status);
3165 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3168 fg_pipe->cmds[i].is_stopped = 1;
3169 fg_pipe->stopped_cmds++;
3171 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3172 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3173 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3174 /* All processes in fg pipe have exited/stopped */
3176 if (fg_pipe->alive_cmds)
3177 insert_bg_job(fg_pipe);
3181 /* There are still running processes in the fg pipe */
3182 goto wait_more; /* do waitpid again */
3184 /* it wasnt fg_pipe, look for process in bg pipes */
3188 /* We asked to wait for bg or orphaned children */
3189 /* No need to remember exitcode in this case */
3190 for (pi = G.job_list; pi; pi = pi->next) {
3191 for (i = 0; i < pi->num_cmds; i++) {
3192 if (pi->cmds[i].pid == childpid)
3193 goto found_pi_and_prognum;
3196 /* Happens when shell is used as init process (init=/bin/sh) */
3197 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3198 continue; /* do waitpid again */
3200 found_pi_and_prognum:
3203 pi->cmds[i].pid = 0;
3205 if (!pi->alive_cmds) {
3206 if (G_interactive_fd)
3207 printf(JOB_STATUS_FORMAT, pi->jobid,
3208 "Done", pi->cmdtext);
3209 delete_finished_bg_job(pi);
3213 pi->cmds[i].is_stopped = 1;
3217 } /* while (waitpid succeeds)... */
3223 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3226 int rcode = checkjobs(fg_pipe);
3227 /* Job finished, move the shell to the foreground */
3228 p = getpgid(0); /* pgid of our process */
3229 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3230 tcsetpgrp(G_interactive_fd, p);
3235 /* Start all the jobs, but don't wait for anything to finish.
3238 * Return code is normally -1, when the caller has to wait for children
3239 * to finish to determine the exit status of the pipe. If the pipe
3240 * is a simple builtin command, however, the action is done by the
3241 * time run_pipe returns, and the exit code is provided as the
3244 * Returns -1 only if started some children. IOW: we have to
3245 * mask out retvals of builtins etc with 0xff!
3247 * The only case when we do not need to [v]fork is when the pipe
3248 * is single, non-backgrounded, non-subshell command. Examples:
3249 * cmd ; ... { list } ; ...
3250 * cmd && ... { list } && ...
3251 * cmd || ... { list } || ...
3252 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3253 * or (if SH_STANDALONE) an applet, and we can run the { list }
3254 * with run_list(). If it isn't one of these, we fork and exec cmd.
3256 * Cases when we must fork:
3257 * non-single: cmd | cmd
3258 * backgrounded: cmd & { list } &
3259 * subshell: ( list ) [&]
3261 static int run_pipe(struct pipe *pi)
3263 static const char *const null_ptr = NULL;
3266 int pipefds[2]; /* pipefds[0] is for reading */
3267 struct command *command;
3268 char **argv_expanded;
3271 /* it is not always needed, but we aim to smaller code */
3272 int squirrel[] = { -1, -1, -1 };
3275 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3278 USE_HUSH_JOB(pi->pgrp = -1;)
3279 pi->stopped_cmds = 0;
3280 command = &(pi->cmds[0]);
3281 argv_expanded = NULL;
3283 if (pi->num_cmds != 1
3284 || pi->followup == PIPE_BG
3285 || command->grp_type == GRP_SUBSHELL
3292 debug_printf_exec(": group:%p argv:'%s'\n",
3293 command->group, command->argv ? command->argv[0] : "NONE");
3295 if (command->group) {
3296 #if ENABLE_HUSH_FUNCTIONS
3297 if (command->grp_type == GRP_FUNCTION) {
3298 /* "executing" func () { list } */
3299 struct function *funcp;
3301 funcp = new_function(command->argv[0]);
3302 /* funcp->name is already set to argv[0] */
3303 funcp->body = command->group;
3305 funcp->body_as_string = command->group_as_string;
3306 command->group_as_string = NULL;
3308 command->group = NULL;
3309 command->argv[0] = NULL;
3310 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3311 funcp->parent_cmd = command;
3312 command->child_func = funcp;
3314 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3316 return EXIT_SUCCESS;
3320 debug_printf("non-subshell group\n");
3321 rcode = 1; /* exitcode if redir failed */
3322 if (setup_redirects(command, squirrel) == 0) {
3323 debug_printf_exec(": run_list\n");
3324 rcode = run_list(command->group) & 0xff;
3326 restore_redirects(squirrel);
3327 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3329 debug_printf_exec("run_pipe: return %d\n", rcode);
3333 argv = command->argv ? command->argv : (char **) &null_ptr;
3335 const struct built_in_command *x;
3336 #if ENABLE_HUSH_FUNCTIONS
3337 const struct function *funcp;
3341 char **new_env = NULL;
3342 char **old_env = NULL;
3344 if (argv[command->assignment_cnt] == NULL) {
3345 /* Assignments, but no command */
3346 /* Ensure redirects take effect. Try "a=t >file" */
3347 rcode = setup_redirects(command, squirrel);
3348 restore_redirects(squirrel);
3349 /* Set shell variables */
3351 p = expand_string_to_string(*argv);
3352 debug_printf_exec("set shell var:'%s'->'%s'\n",
3354 set_local_var(p, 0, 0);
3357 /* Do we need to flag set_local_var() errors?
3358 * "assignment to readonly var" and "putenv error"
3360 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3362 debug_printf_exec("run_pipe: return %d\n", rcode);
3366 /* Expand the rest into (possibly) many strings each */
3367 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3369 x = find_builtin(argv_expanded[0]);
3370 #if ENABLE_HUSH_FUNCTIONS
3373 funcp = find_function(argv_expanded[0]);
3377 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3378 debug_printf("exec with redirects only\n");
3379 rcode = setup_redirects(command, NULL);
3380 goto clean_up_and_ret1;
3383 /* XXX setup_redirects acts on file descriptors, not FILEs.
3384 * This is perfect for work that comes after exec().
3385 * Is it really safe for inline use? Experimentally,
3386 * things seem to work with glibc. */
3387 rcode = setup_redirects(command, squirrel);
3389 new_env = expand_assignments(argv, command->assignment_cnt);
3390 old_env = putenv_all_and_save_old(new_env);
3392 debug_printf_exec(": builtin '%s' '%s'...\n",
3393 x->cmd, argv_expanded[1]);
3394 rcode = x->function(argv_expanded) & 0xff;
3396 #if ENABLE_HUSH_FUNCTIONS
3398 debug_printf_exec(": function '%s' '%s'...\n",
3399 funcp->name, argv_expanded[1]);
3400 rcode = run_function(funcp, argv_expanded) & 0xff;
3404 #if ENABLE_FEATURE_SH_STANDALONE
3407 restore_redirects(squirrel);
3408 free_strings_and_unsetenv(new_env, 1);
3409 putenv_all(old_env);
3410 /* Free the pointers, but the strings themselves
3411 * are in environ now, don't use free_strings! */
3414 free(argv_expanded);
3415 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3417 debug_printf_exec("run_pipe return %d\n", rcode);
3421 #if ENABLE_FEATURE_SH_STANDALONE
3422 i = find_applet_by_name(argv_expanded[0]);
3423 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3424 rcode = setup_redirects(command, squirrel);
3426 new_env = expand_assignments(argv, command->assignment_cnt);
3427 old_env = putenv_all_and_save_old(new_env);
3428 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3429 argv_expanded[0], argv_expanded[1]);
3430 rcode = run_nofork_applet(i, argv_expanded);
3432 goto clean_up_and_ret;
3435 /* It is neither builtin nor applet. We must fork. */
3439 /* NB: argv_expanded may already be created, and that
3440 * might include `cmd` runs! Do not rerun it! We *must*
3441 * use argv_expanded if it's non-NULL */
3443 /* Going to fork a child per each pipe member */
3447 for (i = 0; i < pi->num_cmds; i++) {
3449 volatile nommu_save_t nommu_save;
3450 nommu_save.new_env = NULL;
3451 nommu_save.old_env = NULL;
3452 nommu_save.argv = NULL;
3453 nommu_save.argv_from_re_execing = NULL;
3455 command = &(pi->cmds[i]);
3456 if (command->argv) {
3457 debug_printf_exec(": pipe member '%s' '%s'...\n",
3458 command->argv[0], command->argv[1]);
3460 debug_printf_exec(": pipe member with no argv\n");
3463 /* pipes are inserted between pairs of commands */
3466 if ((i + 1) < pi->num_cmds)
3469 command->pid = BB_MMU ? fork() : vfork();
3470 if (!command->pid) { /* child */
3472 disable_restore_tty_pgrp_on_exit();
3474 /* Every child adds itself to new process group
3475 * with pgid == pid_of_first_child_in_pipe */
3476 if (G.run_list_level == 1 && G_interactive_fd) {
3479 if (pgrp < 0) /* true for 1st process only */
3481 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3482 /* We do it in *every* child, not just first,
3484 tcsetpgrp(G_interactive_fd, pgrp);
3488 xmove_fd(nextin, 0);
3489 xmove_fd(pipefds[1], 1); /* write end */
3491 close(pipefds[0]); /* read end */
3492 /* Like bash, explicit redirects override pipes,
3493 * and the pipe fd is available for dup'ing. */
3494 if (setup_redirects(command, NULL))
3497 /* Restore default handlers just prior to exec */
3498 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3500 /* Stores to nommu_save list of env vars putenv'ed
3501 * (NOMMU, on MMU we don't need that) */
3502 /* cast away volatility... */
3503 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3504 /* pseudo_exec() does not return */
3507 /* parent or error */
3508 enable_restore_tty_pgrp_on_exit();
3510 /* Clean up after vforked child */
3511 free(nommu_save.argv);
3512 free(nommu_save.argv_from_re_execing);
3513 free_strings_and_unsetenv(nommu_save.new_env, 1);
3514 putenv_all(nommu_save.old_env);
3515 /* Free the pointers, but the strings themselves
3516 * are in environ now, don't use free_strings! */
3517 free(nommu_save.old_env);
3519 free(argv_expanded);
3520 argv_expanded = NULL;
3521 if (command->pid < 0) { /* [v]fork failed */
3522 /* Clearly indicate, was it fork or vfork */
3523 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3527 /* Second and next children need to know pid of first one */
3529 pi->pgrp = command->pid;
3535 if ((i + 1) < pi->num_cmds)
3536 close(pipefds[1]); /* write end */
3537 /* Pass read (output) pipe end to next iteration */
3538 nextin = pipefds[0];
3541 if (!pi->alive_cmds) {
3543 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3548 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3552 #ifndef debug_print_tree
3553 static void debug_print_tree(struct pipe *pi, int lvl)
3555 static const char *const PIPE[] = {
3561 static const char *RES[] = {
3562 [RES_NONE ] = "NONE" ,
3565 [RES_THEN ] = "THEN" ,
3566 [RES_ELIF ] = "ELIF" ,
3567 [RES_ELSE ] = "ELSE" ,
3570 #if ENABLE_HUSH_LOOPS
3571 [RES_FOR ] = "FOR" ,
3572 [RES_WHILE] = "WHILE",
3573 [RES_UNTIL] = "UNTIL",
3575 [RES_DONE ] = "DONE" ,
3577 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3580 #if ENABLE_HUSH_CASE
3581 [RES_CASE ] = "CASE" ,
3582 [RES_MATCH] = "MATCH",
3583 [RES_CASEI] = "CASEI",
3584 [RES_ESAC ] = "ESAC" ,
3586 [RES_XXXX ] = "XXXX" ,
3587 [RES_SNTX ] = "SNTX" ,
3589 static const char *const GRPTYPE[] = {
3592 #if ENABLE_HUSH_FUNCTIONS
3601 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3602 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3604 while (prn < pi->num_cmds) {
3605 struct command *command = &pi->cmds[prn];
3606 char **argv = command->argv;
3608 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3610 command->assignment_cnt);
3611 if (command->group) {
3612 fprintf(stderr, " group %s: (argv=%p)\n",
3613 GRPTYPE[command->grp_type],
3615 debug_print_tree(command->group, lvl+1);
3619 if (argv) while (*argv) {
3620 fprintf(stderr, " '%s'", *argv);
3623 fprintf(stderr, "\n");
3632 /* NB: called by pseudo_exec, and therefore must not modify any
3633 * global data until exec/_exit (we can be a child after vfork!) */
3634 static int run_list(struct pipe *pi)
3636 #if ENABLE_HUSH_CASE
3637 char *case_word = NULL;
3639 #if ENABLE_HUSH_LOOPS
3640 struct pipe *loop_top = NULL;
3641 char *for_varname = NULL;
3642 char **for_lcur = NULL;
3643 char **for_list = NULL;
3645 smallint last_followup;
3647 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3648 smalluint cond_code = 0;
3650 enum { cond_code = 0 };
3653 smallint rword; /* enum reserved_style */
3654 smallint last_rword; /* ditto */
3657 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3660 #if ENABLE_HUSH_LOOPS
3661 /* Check syntax for "for" */
3662 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3663 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3665 /* current word is FOR or IN (BOLD in comments below) */
3666 if (cpipe->next == NULL) {
3667 syntax_error("malformed for");
3669 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3672 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3673 if (cpipe->next->res_word == RES_DO)
3675 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3676 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3677 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3679 syntax_error("malformed for");
3681 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3687 /* Past this point, all code paths should jump to ret: label
3688 * in order to return, no direct "return" statements please.
3689 * This helps to ensure that no memory is leaked. */
3697 last_rword = RES_XXXX;
3699 last_followup = PIPE_SEQ;
3700 rcode = G.last_exitcode;
3702 /* Go through list of pipes, (maybe) executing them. */
3703 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3707 IF_HAS_KEYWORDS(rword = pi->res_word;)
3708 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3709 rword, cond_code, last_rword);
3710 #if ENABLE_HUSH_LOOPS
3711 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3712 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3714 /* start of a loop: remember where loop starts */
3719 /* Still in the same "if...", "then..." or "do..." branch? */
3720 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3721 if ((rcode == 0 && last_followup == PIPE_OR)
3722 || (rcode != 0 && last_followup == PIPE_AND)
3724 /* It is "<true> || CMD" or "<false> && CMD"
3725 * and we should not execute CMD */
3726 debug_printf_exec("skipped cmd because of || or &&\n");
3727 last_followup = pi->followup;
3731 last_followup = pi->followup;
3732 IF_HAS_KEYWORDS(last_rword = rword;)
3735 if (rword == RES_THEN) {
3736 /* if false; then ... fi has exitcode 0! */
3737 G.last_exitcode = rcode = EXIT_SUCCESS;
3738 /* "if <false> THEN cmd": skip cmd */
3742 if (rword == RES_ELSE || rword == RES_ELIF) {
3743 /* "if <true> then ... ELSE/ELIF cmd":
3744 * skip cmd and all following ones */
3749 #if ENABLE_HUSH_LOOPS
3750 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3752 /* first loop through for */
3754 static const char encoded_dollar_at[] ALIGN1 = {
3755 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3756 }; /* encoded representation of "$@" */
3757 static const char *const encoded_dollar_at_argv[] = {
3758 encoded_dollar_at, NULL
3759 }; /* argv list with one element: "$@" */
3762 vals = (char**)encoded_dollar_at_argv;
3763 if (pi->next->res_word == RES_IN) {
3764 /* if no variable values after "in" we skip "for" */
3765 if (!pi->next->cmds[0].argv) {
3766 G.last_exitcode = rcode = EXIT_SUCCESS;
3767 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3770 vals = pi->next->cmds[0].argv;
3771 } /* else: "for var; do..." -> assume "$@" list */
3772 /* create list of variable values */
3773 debug_print_strings("for_list made from", vals);
3774 for_list = expand_strvec_to_strvec(vals);
3775 for_lcur = for_list;
3776 debug_print_strings("for_list", for_list);
3777 for_varname = pi->cmds[0].argv[0];
3778 pi->cmds[0].argv[0] = NULL;
3780 free(pi->cmds[0].argv[0]);
3782 /* "for" loop is over, clean up */
3786 pi->cmds[0].argv[0] = for_varname;
3789 /* Insert next value from for_lcur */
3790 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3791 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3792 pi->cmds[0].assignment_cnt = 1;
3794 if (rword == RES_IN) {
3795 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3797 if (rword == RES_DONE) {
3798 continue; /* "done" has no cmds too */
3801 #if ENABLE_HUSH_CASE
3802 if (rword == RES_CASE) {
3803 case_word = expand_strvec_to_string(pi->cmds->argv);
3806 if (rword == RES_MATCH) {
3809 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3811 /* all prev words didn't match, does this one match? */
3812 argv = pi->cmds->argv;
3814 char *pattern = expand_string_to_string(*argv);
3815 /* TODO: which FNM_xxx flags to use? */
3816 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3818 if (cond_code == 0) { /* match! we will execute this branch */
3819 free(case_word); /* make future "word)" stop */
3827 if (rword == RES_CASEI) { /* inside of a case branch */
3829 continue; /* not matched yet, skip this pipe */
3832 /* Just pressing <enter> in shell should check for jobs.
3833 * OTOH, in non-interactive shell this is useless
3834 * and only leads to extra job checks */
3835 if (pi->num_cmds == 0) {
3836 if (G_interactive_fd)
3837 goto check_jobs_and_continue;
3841 /* After analyzing all keywords and conditions, we decided
3842 * to execute this pipe. NB: have to do checkjobs(NULL)
3843 * after run_pipe to collect any background children,
3844 * even if list execution is to be stopped. */
3845 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3848 #if ENABLE_HUSH_LOOPS
3849 G.flag_break_continue = 0;
3851 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3853 /* We only ran a builtin: rcode is already known
3854 * and we don't need to wait for anything. */
3855 G.last_exitcode = rcode;
3856 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3857 check_and_run_traps(0);
3858 #if ENABLE_HUSH_LOOPS
3859 /* Was it "break" or "continue"? */
3860 if (G.flag_break_continue) {
3861 smallint fbc = G.flag_break_continue;
3862 /* We might fall into outer *loop*,
3863 * don't want to break it too */
3865 G.depth_break_continue--;
3866 if (G.depth_break_continue == 0)
3867 G.flag_break_continue = 0;
3868 /* else: e.g. "continue 2" should *break* once, *then* continue */
3869 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3870 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3871 goto check_jobs_and_break;
3872 /* "continue": simulate end of loop */
3877 } else if (pi->followup == PIPE_BG) {
3878 /* What does bash do with attempts to background builtins? */
3879 /* even bash 3.2 doesn't do that well with nested bg:
3880 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3881 * I'm NOT treating inner &'s as jobs */
3882 check_and_run_traps(0);
3884 if (G.run_list_level == 1)
3887 G.last_exitcode = rcode = EXIT_SUCCESS;
3888 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3891 if (G.run_list_level == 1 && G_interactive_fd) {
3892 /* Waits for completion, then fg's main shell */
3893 rcode = checkjobs_and_fg_shell(pi);
3894 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3895 check_and_run_traps(0);
3898 { /* This one just waits for completion */
3899 rcode = checkjobs(pi);
3900 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3901 check_and_run_traps(0);
3903 G.last_exitcode = rcode;
3907 /* Analyze how result affects subsequent commands */
3909 if (rword == RES_IF || rword == RES_ELIF)
3912 #if ENABLE_HUSH_LOOPS
3913 /* Beware of "while false; true; do ..."! */
3914 if (pi->next && pi->next->res_word == RES_DO) {
3915 if (rword == RES_WHILE) {
3917 /* "while false; do...done" - exitcode 0 */
3918 G.last_exitcode = rcode = EXIT_SUCCESS;
3919 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3920 goto check_jobs_and_break;
3923 if (rword == RES_UNTIL) {
3925 debug_printf_exec(": until expr is true: breaking\n");
3926 check_jobs_and_break:
3934 check_jobs_and_continue:
3941 #if ENABLE_HUSH_LOOPS
3946 #if ENABLE_HUSH_CASE
3950 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3954 /* Select which version we will use */
3955 static int run_and_free_list(struct pipe *pi)
3958 debug_printf_exec("run_and_free_list entered\n");
3960 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3961 rcode = run_list(pi);
3963 /* free_pipe_list has the side effect of clearing memory.
3964 * In the long run that function can be merged with run_list,
3965 * but doing that now would hobble the debugging effort. */
3967 debug_printf_exec("run_and_free_list return %d\n", rcode);
3972 static struct pipe *new_pipe(void)
3975 pi = xzalloc(sizeof(struct pipe));
3976 /*pi->followup = 0; - deliberately invalid value */
3977 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3981 /* Command (member of a pipe) is complete, or we start a new pipe
3982 * if ctx->command is NULL.
3983 * No errors possible here.
3985 static int done_command(struct parse_context *ctx)
3987 /* The command is really already in the pipe structure, so
3988 * advance the pipe counter and make a new, null command. */
3989 struct pipe *pi = ctx->pipe;
3990 struct command *command = ctx->command;
3993 if (IS_NULL_CMD(command)) {
3994 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3998 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3999 //debug_print_tree(ctx->list_head, 20);
4001 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4004 /* Only real trickiness here is that the uncommitted
4005 * command structure is not counted in pi->num_cmds. */
4006 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4007 ctx->command = command = &pi->cmds[pi->num_cmds];
4009 memset(command, 0, sizeof(*command));
4010 return pi->num_cmds; /* used only for 0/nonzero check */
4013 static void done_pipe(struct parse_context *ctx, pipe_style type)
4017 debug_printf_parse("done_pipe entered, followup %d\n", type);
4018 /* Close previous command */
4019 not_null = done_command(ctx);
4020 ctx->pipe->followup = type;
4022 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4023 ctx->ctx_inverted = 0;
4024 ctx->pipe->res_word = ctx->ctx_res_w;
4027 /* Without this check, even just <enter> on command line generates
4028 * tree of three NOPs (!). Which is harmless but annoying.
4029 * IOW: it is safe to do it unconditionally. */
4032 || ctx->ctx_res_w == RES_FI
4034 #if ENABLE_HUSH_LOOPS
4035 || ctx->ctx_res_w == RES_DONE
4036 || ctx->ctx_res_w == RES_FOR
4037 || ctx->ctx_res_w == RES_IN
4039 #if ENABLE_HUSH_CASE
4040 || ctx->ctx_res_w == RES_ESAC
4044 debug_printf_parse("done_pipe: adding new pipe: "
4045 "not_null:%d ctx->ctx_res_w:%d\n",
4046 not_null, ctx->ctx_res_w);
4048 ctx->pipe->next = new_p;
4050 /* RES_THEN, RES_DO etc are "sticky" -
4051 * they remain set for pipes inside if/while.
4052 * This is used to control execution.
4053 * RES_FOR and RES_IN are NOT sticky (needed to support
4054 * cases where variable or value happens to match a keyword):
4056 #if ENABLE_HUSH_LOOPS
4057 if (ctx->ctx_res_w == RES_FOR
4058 || ctx->ctx_res_w == RES_IN)
4059 ctx->ctx_res_w = RES_NONE;
4061 #if ENABLE_HUSH_CASE
4062 if (ctx->ctx_res_w == RES_MATCH)
4063 ctx->ctx_res_w = RES_CASEI;
4065 ctx->command = NULL; /* trick done_command below */
4066 /* Create the memory for command, roughly:
4067 * ctx->pipe->cmds = new struct command;
4068 * ctx->command = &ctx->pipe->cmds[0];
4071 //debug_print_tree(ctx->list_head, 10);
4073 debug_printf_parse("done_pipe return\n");
4076 static void initialize_context(struct parse_context *ctx)
4078 memset(ctx, 0, sizeof(*ctx));
4079 ctx->pipe = ctx->list_head = new_pipe();
4080 /* Create the memory for command, roughly:
4081 * ctx->pipe->cmds = new struct command;
4082 * ctx->command = &ctx->pipe->cmds[0];
4087 /* If a reserved word is found and processed, parse context is modified
4088 * and 1 is returned.
4091 struct reserved_combo {
4094 unsigned char assignment_flag;
4098 FLAG_END = (1 << RES_NONE ),
4100 FLAG_IF = (1 << RES_IF ),
4101 FLAG_THEN = (1 << RES_THEN ),
4102 FLAG_ELIF = (1 << RES_ELIF ),
4103 FLAG_ELSE = (1 << RES_ELSE ),
4104 FLAG_FI = (1 << RES_FI ),
4106 #if ENABLE_HUSH_LOOPS
4107 FLAG_FOR = (1 << RES_FOR ),
4108 FLAG_WHILE = (1 << RES_WHILE),
4109 FLAG_UNTIL = (1 << RES_UNTIL),
4110 FLAG_DO = (1 << RES_DO ),
4111 FLAG_DONE = (1 << RES_DONE ),
4112 FLAG_IN = (1 << RES_IN ),
4114 #if ENABLE_HUSH_CASE
4115 FLAG_MATCH = (1 << RES_MATCH),
4116 FLAG_ESAC = (1 << RES_ESAC ),
4118 FLAG_START = (1 << RES_XXXX ),
4121 static const struct reserved_combo* match_reserved_word(o_string *word)
4123 /* Mostly a list of accepted follow-up reserved words.
4124 * FLAG_END means we are done with the sequence, and are ready
4125 * to turn the compound list into a command.
4126 * FLAG_START means the word must start a new compound list.
4128 static const struct reserved_combo reserved_list[] = {
4130 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4131 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4132 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4133 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4134 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4135 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4137 #if ENABLE_HUSH_LOOPS
4138 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4139 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4140 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4141 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4142 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4143 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4145 #if ENABLE_HUSH_CASE
4146 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4147 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4150 const struct reserved_combo *r;
4152 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4153 if (strcmp(word->data, r->literal) == 0)
4158 /* Return 0: not a keyword, 1: keyword
4160 static int reserved_word(o_string *word, struct parse_context *ctx)
4162 #if ENABLE_HUSH_CASE
4163 static const struct reserved_combo reserved_match = {
4164 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4167 const struct reserved_combo *r;
4171 r = match_reserved_word(word);
4175 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4176 #if ENABLE_HUSH_CASE
4177 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4178 /* "case word IN ..." - IN part starts first match part */
4179 r = &reserved_match;
4182 if (r->flag == 0) { /* '!' */
4183 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4184 syntax_error("! ! command");
4185 ctx->ctx_res_w = RES_SNTX;
4187 ctx->ctx_inverted = 1;
4190 if (r->flag & FLAG_START) {
4191 struct parse_context *old;
4193 old = xmalloc(sizeof(*old));
4194 debug_printf_parse("push stack %p\n", old);
4195 *old = *ctx; /* physical copy */
4196 initialize_context(ctx);
4198 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4199 syntax_error_at(word->data);
4200 ctx->ctx_res_w = RES_SNTX;
4203 /* "{...} fi" is ok. "{...} if" is not
4205 * if { echo foo; } then { echo bar; } fi */
4206 if (ctx->command->group)
4207 done_pipe(ctx, PIPE_SEQ);
4210 ctx->ctx_res_w = r->res;
4211 ctx->old_flag = r->flag;
4212 word->o_assignment = r->assignment_flag;
4214 if (ctx->old_flag & FLAG_END) {
4215 struct parse_context *old;
4217 done_pipe(ctx, PIPE_SEQ);
4218 debug_printf_parse("pop stack %p\n", ctx->stack);
4220 old->command->group = ctx->list_head;
4221 old->command->grp_type = GRP_NORMAL;
4223 o_addstr(&old->as_string, ctx->as_string.data);
4224 o_free_unsafe(&ctx->as_string);
4225 old->command->group_as_string = xstrdup(old->as_string.data);
4226 debug_printf_parse("pop, remembering as:'%s'\n",
4227 old->command->group_as_string);
4229 *ctx = *old; /* physical copy */
4236 /* Word is complete, look at it and update parsing context.
4237 * Normal return is 0. Syntax errors return 1.
4238 * Note: on return, word is reset, but not o_free'd!
4240 static int done_word(o_string *word, struct parse_context *ctx)
4242 struct command *command = ctx->command;
4244 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4245 if (word->length == 0 && word->o_quoted == 0) {
4246 debug_printf_parse("done_word return 0: true null, ignored\n");
4250 if (ctx->pending_redirect) {
4251 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4252 * only if run as "bash", not "sh" */
4253 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4255 * ...the word that follows the redirection operator
4256 * shall be subjected to tilde expansion, parameter expansion,
4257 * command substitution, arithmetic expansion, and quote
4258 * removal. Pathname expansion shall not be performed
4259 * on the word by a non-interactive shell; an interactive
4260 * shell may perform it, but shall do so only when
4261 * the expansion would result in one word."
4263 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4264 /* Cater for >\file case:
4265 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4266 * Same with heredocs:
4267 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4269 unbackslash(ctx->pending_redirect->rd_filename);
4270 /* Is it <<"HEREDOC"? */
4271 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4274 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4276 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4277 ctx->pending_redirect = NULL;
4279 /* If this word wasn't an assignment, next ones definitely
4280 * can't be assignments. Even if they look like ones. */
4281 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4282 && word->o_assignment != WORD_IS_KEYWORD
4284 word->o_assignment = NOT_ASSIGNMENT;
4286 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4287 command->assignment_cnt++;
4288 word->o_assignment = MAYBE_ASSIGNMENT;
4292 # if ENABLE_HUSH_CASE
4293 if (ctx->ctx_dsemicolon
4294 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4296 /* already done when ctx_dsemicolon was set to 1: */
4297 /* ctx->ctx_res_w = RES_MATCH; */
4298 ctx->ctx_dsemicolon = 0;
4301 if (!command->argv /* if it's the first word... */
4302 # if ENABLE_HUSH_LOOPS
4303 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4304 && ctx->ctx_res_w != RES_IN
4307 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4308 if (reserved_word(word, ctx)) {
4309 o_reset_to_empty_unquoted(word);
4310 debug_printf_parse("done_word return %d\n",
4311 (ctx->ctx_res_w == RES_SNTX));
4312 return (ctx->ctx_res_w == RES_SNTX);
4316 if (command->group) {
4317 /* "{ echo foo; } echo bar" - bad */
4318 syntax_error_at(word->data);
4319 debug_printf_parse("done_word return 1: syntax error, "
4320 "groups and arglists don't mix\n");
4323 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4324 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4325 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4326 /* (otherwise it's known to be not empty and is already safe) */
4328 /* exclude "$@" - it can expand to no word despite "" */
4329 char *p = word->data;
4330 while (p[0] == SPECIAL_VAR_SYMBOL
4331 && (p[1] & 0x7f) == '@'
4332 && p[2] == SPECIAL_VAR_SYMBOL
4336 if (p == word->data || p[0] != '\0') {
4337 /* saw no "$@", or not only "$@" but some
4338 * real text is there too */
4339 /* insert "empty variable" reference, this makes
4340 * e.g. "", $empty"" etc to not disappear */
4341 o_addchr(word, SPECIAL_VAR_SYMBOL);
4342 o_addchr(word, SPECIAL_VAR_SYMBOL);
4345 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4346 //SEGV, but good idea.
4347 // command->argv = add_string_to_strings(command->argv, word->data);
4348 // word->data = NULL;
4349 // word->length = 0;
4350 debug_print_strings("word appended to argv", command->argv);
4353 #if ENABLE_HUSH_LOOPS
4354 if (ctx->ctx_res_w == RES_FOR) {
4356 || !is_well_formed_var_name(command->argv[0], '\0')
4358 /* bash says just "not a valid identifier" */
4359 syntax_error("not a valid identifier in for");
4362 /* Force FOR to have just one word (variable name) */
4363 /* NB: basically, this makes hush see "for v in ..."
4364 * syntax as if it is "for v; in ...". FOR and IN become
4365 * two pipe structs in parse tree. */
4366 done_pipe(ctx, PIPE_SEQ);
4369 #if ENABLE_HUSH_CASE
4370 /* Force CASE to have just one word */
4371 if (ctx->ctx_res_w == RES_CASE) {
4372 done_pipe(ctx, PIPE_SEQ);
4376 o_reset_to_empty_unquoted(word);
4378 debug_printf_parse("done_word return 0\n");
4383 /* Peek ahead in the input to find out if we have a "&n" construct,
4384 * as in "2>&1", that represents duplicating a file descriptor.
4386 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4387 * REDIRFD_SYNTAX_ERR if syntax error,
4388 * REDIRFD_TO_FILE if no & was seen,
4389 * or the number found.
4392 #define parse_redir_right_fd(as_string, input) \
4393 parse_redir_right_fd(input)
4395 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4401 return REDIRFD_TO_FILE;
4403 ch = i_getch(input); /* get the & */
4404 nommu_addchr(as_string, ch);
4407 ch = i_getch(input);
4408 nommu_addchr(as_string, ch);
4409 return REDIRFD_CLOSE;
4413 while (ch != EOF && isdigit(ch)) {
4414 d = d*10 + (ch-'0');
4416 ch = i_getch(input);
4417 nommu_addchr(as_string, ch);
4422 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4424 bb_error_msg("ambiguous redirect");
4425 return REDIRFD_SYNTAX_ERR;
4428 /* Return code is 0 normal, 1 if a syntax error is detected
4430 static int parse_redirect(struct parse_context *ctx,
4433 struct in_str *input)
4435 struct command *command = ctx->command;
4436 struct redir_struct *redir;
4437 struct redir_struct **redirp;
4440 dup_num = REDIRFD_TO_FILE;
4441 if (style != REDIRECT_HEREDOC) {
4442 /* Check for a '>&1' type redirect */
4443 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4444 if (dup_num == REDIRFD_SYNTAX_ERR)
4447 int ch = i_peek(input);
4448 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4449 if (dup_num) { /* <<-... */
4450 ch = i_getch(input);
4451 nommu_addchr(&ctx->as_string, ch);
4456 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4457 int ch = i_peek(input);
4459 /* >|FILE redirect ("clobbering" >).
4460 * Since we do not support "set -o noclobber" yet,
4461 * >| and > are the same for now. Just eat |.
4463 ch = i_getch(input);
4464 nommu_addchr(&ctx->as_string, ch);
4468 /* Create a new redir_struct and append it to the linked list */
4469 redirp = &command->redirects;
4470 while ((redir = *redirp) != NULL) {
4471 redirp = &(redir->next);
4473 *redirp = redir = xzalloc(sizeof(*redir));
4474 /* redir->next = NULL; */
4475 /* redir->rd_filename = NULL; */
4476 redir->rd_type = style;
4477 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4479 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4480 redir_table[style].descrip);
4482 redir->rd_dup = dup_num;
4483 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4484 /* Erik had a check here that the file descriptor in question
4485 * is legit; I postpone that to "run time"
4486 * A "-" representation of "close me" shows up as a -3 here */
4487 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4488 redir->rd_fd, redir->rd_dup);
4490 /* Set ctx->pending_redirect, so we know what to do at the
4491 * end of the next parsed word. */
4492 ctx->pending_redirect = redir;
4497 /* If a redirect is immediately preceded by a number, that number is
4498 * supposed to tell which file descriptor to redirect. This routine
4499 * looks for such preceding numbers. In an ideal world this routine
4500 * needs to handle all the following classes of redirects...
4501 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4502 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4503 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4504 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4506 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4508 * ... If n is quoted, the number shall not be recognized as part of
4509 * the redirection expression. For example:
4511 * writes the character 2 into file a"
4512 * We are getting it right by setting ->o_quoted on any \<char>
4514 * A -1 return means no valid number was found,
4515 * the caller should use the appropriate default for this redirection.
4517 static int redirect_opt_num(o_string *o)
4521 if (o->data == NULL)
4523 num = bb_strtou(o->data, NULL, 10);
4524 if (errno || num < 0)
4526 o_reset_to_empty_unquoted(o);
4531 #define fetch_till_str(as_string, input, word, skip_tabs) \
4532 fetch_till_str(input, word, skip_tabs)
4534 static char *fetch_till_str(o_string *as_string,
4535 struct in_str *input,
4539 o_string heredoc = NULL_O_STRING;
4545 ch = i_getch(input);
4546 nommu_addchr(as_string, ch);
4548 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4549 heredoc.data[past_EOL] = '\0';
4550 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4551 return heredoc.data;
4554 o_addchr(&heredoc, ch);
4555 past_EOL = heredoc.length;
4558 ch = i_getch(input);
4559 nommu_addchr(as_string, ch);
4560 } while (skip_tabs && ch == '\t');
4561 } while (ch == '\n');
4564 o_free_unsafe(&heredoc);
4567 o_addchr(&heredoc, ch);
4568 nommu_addchr(as_string, ch);
4572 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4573 * and load them all. There should be exactly heredoc_cnt of them.
4575 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4577 struct pipe *pi = ctx->list_head;
4579 while (pi && heredoc_cnt) {
4581 struct command *cmd = pi->cmds;
4583 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4585 cmd->argv ? cmd->argv[0] : "NONE");
4586 for (i = 0; i < pi->num_cmds; i++) {
4587 struct redir_struct *redir = cmd->redirects;
4589 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4590 i, cmd->argv ? cmd->argv[0] : "NONE");
4592 if (redir->rd_type == REDIRECT_HEREDOC) {
4595 redir->rd_type = REDIRECT_HEREDOC2;
4596 /* redir->dup is (ab)used to indicate <<- */
4597 p = fetch_till_str(&ctx->as_string, input,
4598 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4600 syntax_error("unexpected EOF in here document");
4603 free(redir->rd_filename);
4604 redir->rd_filename = p;
4607 redir = redir->next;
4614 /* Should be 0. If it isn't, it's a parse error */
4616 bb_error_msg_and_die("heredoc BUG 2");
4622 #if ENABLE_HUSH_TICK
4623 static FILE *generate_stream_from_string(const char *s)
4626 int pid, channel[2];
4632 pid = BB_MMU ? fork() : vfork();
4634 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4636 if (pid == 0) { /* child */
4637 disable_restore_tty_pgrp_on_exit();
4638 /* Process substitution is not considered to be usual
4639 * 'command execution'.
4640 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4647 close(channel[0]); /* NB: close _first_, then move fd! */
4648 xmove_fd(channel[1], 1);
4649 /* Prevent it from trying to handle ctrl-z etc */
4650 USE_HUSH_JOB(G.run_list_level = 1;)
4652 reset_traps_to_defaults();
4653 parse_and_run_string(s);
4654 _exit(G.last_exitcode);
4656 /* We re-execute after vfork on NOMMU. This makes this script safe:
4657 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4658 * huge=`cat BIG` # was blocking here forever
4661 re_execute_shell(&to_free,
4669 enable_restore_tty_pgrp_on_exit();
4674 pf = fdopen(channel[0], "r");
4678 /* Return code is exit status of the process that is run. */
4679 static int process_command_subs(o_string *dest, const char *s)
4682 struct in_str pipe_str;
4685 pf = generate_stream_from_string(s);
4688 close_on_exec_on(fileno(pf));
4690 /* Now send results of command back into original context */
4691 setup_file_in_str(&pipe_str, pf);
4693 while ((ch = i_getch(&pipe_str)) != EOF) {
4699 o_addchr(dest, '\n');
4702 o_addQchr(dest, ch);
4705 debug_printf("done reading from pipe, pclose()ing\n");
4706 /* Note: we got EOF, and we just close the read end of the pipe.
4707 * We do not wait for the `cmd` child to terminate. bash and ash do.
4709 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4710 * `false`; echo $? - bash outputs "1"
4713 debug_printf("closed FILE from child. return 0\n");
4718 static int parse_group(o_string *dest, struct parse_context *ctx,
4719 struct in_str *input, int ch)
4721 /* dest contains characters seen prior to ( or {.
4722 * Typically it's empty, but for function defs,
4723 * it contains function name (without '()'). */
4724 struct pipe *pipe_list;
4726 struct command *command = ctx->command;
4728 debug_printf_parse("parse_group entered\n");
4729 #if ENABLE_HUSH_FUNCTIONS
4730 if (ch == '(' && !dest->o_quoted) {
4732 if (done_word(dest, ctx))
4735 goto skip; /* (... */
4736 if (command->argv[1]) { /* word word ... (... */
4737 syntax_error_unexpected_ch('(');
4740 /* it is "word(..." or "word (..." */
4742 ch = i_getch(input);
4743 while (ch == ' ' || ch == '\t');
4745 syntax_error_unexpected_ch(ch);
4748 nommu_addchr(&ctx->as_string, ch);
4750 ch = i_getch(input);
4751 while (ch == ' ' || ch == '\t' || ch == '\n');
4753 syntax_error_unexpected_ch(ch);
4756 nommu_addchr(&ctx->as_string, ch);
4757 command->grp_type = GRP_FUNCTION;
4761 if (command->argv /* word [word]{... */
4762 || dest->length /* word{... */
4763 || dest->o_quoted /* ""{... */
4766 debug_printf_parse("parse_group return 1: "
4767 "syntax error, groups and arglists don't mix\n");
4771 #if ENABLE_HUSH_FUNCTIONS
4777 command->grp_type = GRP_SUBSHELL;
4779 /* bash does not allow "{echo...", requires whitespace */
4780 ch = i_getch(input);
4781 if (ch != ' ' && ch != '\t' && ch != '\n') {
4782 syntax_error_unexpected_ch(ch);
4785 nommu_addchr(&ctx->as_string, ch);
4790 char *as_string = NULL;
4792 pipe_list = parse_stream(&as_string, input, endch);
4795 o_addstr(&ctx->as_string, as_string);
4797 /* empty ()/{} or parse error? */
4798 if (!pipe_list || pipe_list == ERR_PTR) {
4799 /* parse_stream already emitted error msg */
4803 debug_printf_parse("parse_group return 1: "
4804 "parse_stream returned %p\n", pipe_list);
4807 command->group = pipe_list;
4809 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4810 command->group_as_string = as_string;
4811 debug_printf_parse("end of group, remembering as:'%s'\n",
4812 command->group_as_string);
4815 debug_printf_parse("parse_group return 0\n");
4817 /* command remains "open", available for possible redirects */
4820 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4821 /* Subroutines for copying $(...) and `...` things */
4822 static void add_till_backquote(o_string *dest, struct in_str *input);
4824 static void add_till_single_quote(o_string *dest, struct in_str *input)
4827 int ch = i_getch(input);
4829 syntax_error_unterm_ch('\'');
4830 /*xfunc_die(); - redundant */
4837 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4838 static void add_till_double_quote(o_string *dest, struct in_str *input)
4841 int ch = i_getch(input);
4843 syntax_error_unterm_ch('"');
4844 /*xfunc_die(); - redundant */
4848 if (ch == '\\') { /* \x. Copy both chars. */
4850 ch = i_getch(input);
4854 add_till_backquote(dest, input);
4858 //if (ch == '$') ...
4861 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4863 * "Within the backquoted style of command substitution, backslash
4864 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4865 * The search for the matching backquote shall be satisfied by the first
4866 * backquote found without a preceding backslash; during this search,
4867 * if a non-escaped backquote is encountered within a shell comment,
4868 * a here-document, an embedded command substitution of the $(command)
4869 * form, or a quoted string, undefined results occur. A single-quoted
4870 * or double-quoted string that begins, but does not end, within the
4871 * "`...`" sequence produces undefined results."
4873 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4875 static void add_till_backquote(o_string *dest, struct in_str *input)
4878 int ch = i_getch(input);
4880 syntax_error_unterm_ch('`');
4881 /*xfunc_die(); - redundant */
4886 /* \x. Copy both chars unless it is \` */
4887 int ch2 = i_getch(input);
4889 syntax_error_unterm_ch('`');
4890 /*xfunc_die(); - redundant */
4892 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4899 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4900 * quoting and nested ()s.
4901 * "With the $(command) style of command substitution, all characters
4902 * following the open parenthesis to the matching closing parenthesis
4903 * constitute the command. Any valid shell script can be used for command,
4904 * except a script consisting solely of redirections which produces
4905 * unspecified results."
4907 * echo $(echo '(TEST)' BEST) (TEST) BEST
4908 * echo $(echo 'TEST)' BEST) TEST) BEST
4909 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4911 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4915 int ch = i_getch(input);
4917 syntax_error_unterm_ch(')');
4918 /*xfunc_die(); - redundant */
4926 if (i_peek(input) == ')') {
4934 add_till_single_quote(dest, input);
4939 add_till_double_quote(dest, input);
4944 /* \x. Copy verbatim. Important for \(, \) */
4945 ch = i_getch(input);
4947 syntax_error_unterm_ch(')');
4948 /*xfunc_die(); - redundant */
4955 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4957 /* Return code: 0 for OK, 1 for syntax error */
4959 #define handle_dollar(as_string, dest, input) \
4960 handle_dollar(dest, input)
4962 static int handle_dollar(o_string *as_string,
4964 struct in_str *input)
4967 int ch = i_peek(input); /* first character after the $ */
4968 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4970 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4972 ch = i_getch(input);
4973 nommu_addchr(as_string, ch);
4975 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4977 debug_printf_parse(": '%c'\n", ch);
4978 o_addchr(dest, ch | quote_mask);
4981 if (!isalnum(ch) && ch != '_')
4983 ch = i_getch(input);
4984 nommu_addchr(as_string, ch);
4986 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4987 } else if (isdigit(ch)) {
4989 ch = i_getch(input);
4990 nommu_addchr(as_string, ch);
4991 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4992 debug_printf_parse(": '%c'\n", ch);
4993 o_addchr(dest, ch | quote_mask);
4994 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4995 } else switch (ch) {
4997 case '!': /* last bg pid */
4998 case '?': /* last exit code */
4999 case '#': /* number of args */
5000 case '*': /* args */
5001 case '@': /* args */
5002 goto make_one_char_var;
5004 bool first_char, all_digits;
5006 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5007 ch = i_getch(input);
5008 nommu_addchr(as_string, ch);
5009 /* XXX maybe someone will try to escape the '}' */
5014 ch = i_getch(input);
5015 nommu_addchr(as_string, ch);
5021 /* ${#var}: length of var contents */
5023 else if (isdigit(ch)) {
5030 && ( (all_digits && !isdigit(ch))
5031 || (!all_digits && !isalnum(ch) && ch != '_')
5034 /* handle parameter expansions
5035 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5040 case ':': /* null modifier */
5041 if (expansion == 0) {
5042 debug_printf_parse(": null modifier\n");
5047 case '#': /* remove prefix */
5048 case '%': /* remove suffix */
5049 if (expansion == 0) {
5050 debug_printf_parse(": remove suffix/prefix\n");
5055 case '-': /* default value */
5056 case '=': /* assign default */
5057 case '+': /* alternative */
5058 case '?': /* error indicate */
5059 debug_printf_parse(": parameter expansion\n");
5064 syntax_error_unterm_str("${name}");
5065 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5070 debug_printf_parse(": '%c'\n", ch);
5071 o_addchr(dest, ch | quote_mask);
5075 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5078 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5083 ch = i_getch(input);
5084 nommu_addchr(as_string, ch);
5085 # if ENABLE_SH_MATH_SUPPORT
5086 if (i_peek(input) == '(') {
5087 ch = i_getch(input);
5088 nommu_addchr(as_string, ch);
5089 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5090 o_addchr(dest, /*quote_mask |*/ '+');
5094 add_till_closing_paren(dest, input, true);
5097 o_addstr(as_string, dest->data + pos);
5098 o_addchr(as_string, ')');
5099 o_addchr(as_string, ')');
5102 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5106 # if ENABLE_HUSH_TICK
5107 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5108 o_addchr(dest, quote_mask | '`');
5112 add_till_closing_paren(dest, input, false);
5115 o_addstr(as_string, dest->data + pos);
5116 o_addchr(as_string, '`');
5119 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5125 ch = i_getch(input);
5126 nommu_addchr(as_string, ch);
5128 if (isalnum(ch)) { /* it's $_name or $_123 */
5134 /* $_ Shell or shell script name; or last cmd name */
5135 /* $- Option flags set by set builtin or shell options (-i etc) */
5137 o_addQchr(dest, '$');
5139 debug_printf_parse("handle_dollar return 0\n");
5144 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5145 parse_stream_dquoted(dest, input, dquote_end)
5147 static int parse_stream_dquoted(o_string *as_string,
5149 struct in_str *input,
5156 ch = i_getch(input);
5158 nommu_addchr(as_string, ch);
5159 if (ch == dquote_end) { /* may be only '"' or EOF */
5160 if (dest->o_assignment == NOT_ASSIGNMENT)
5161 dest->o_escape ^= 1;
5162 debug_printf_parse("parse_stream_dquoted return 0\n");
5165 /* note: can't move it above ch == dquote_end check! */
5167 syntax_error_unterm_ch('"');
5168 /*xfunc_die(); - redundant */
5172 next = i_peek(input);
5174 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5175 ch, ch, dest->o_escape);
5178 syntax_error("\\<eof>");
5182 * "The backslash retains its special meaning [in "..."]
5183 * only when followed by one of the following characters:
5184 * $, `, ", \, or <newline>. A double quote may be quoted
5185 * within double quotes by preceding it with a backslash.
5187 if (strchr("$`\"\\", next) != NULL) {
5188 o_addqchr(dest, i_getch(input));
5190 o_addqchr(dest, '\\');
5195 if (handle_dollar(as_string, dest, input) != 0) {
5196 debug_printf_parse("parse_stream_dquoted return 1: "
5197 "handle_dollar returned non-0\n");
5202 #if ENABLE_HUSH_TICK
5204 //int pos = dest->length;
5205 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5206 o_addchr(dest, 0x80 | '`');
5207 add_till_backquote(dest, input);
5208 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5209 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5213 o_addQchr(dest, ch);
5215 && (dest->o_assignment == MAYBE_ASSIGNMENT
5216 || dest->o_assignment == WORD_IS_KEYWORD)
5217 && is_well_formed_var_name(dest->data, '=')
5219 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5225 * Scan input until EOF or end_trigger char.
5226 * Return a list of pipes to execute, or NULL on EOF
5227 * or if end_trigger character is met.
5228 * On syntax error, exit is shell is not interactive,
5229 * reset parsing machinery and start parsing anew,
5230 * or return ERR_PTR.
5232 static struct pipe *parse_stream(char **pstring,
5233 struct in_str *input,
5236 struct parse_context ctx;
5237 o_string dest = NULL_O_STRING;
5241 /* Double-quote state is handled in the state variable is_in_dquote.
5242 * A single-quote triggers a bypass of the main loop until its mate is
5243 * found. When recursing, quote state is passed in via dest->o_escape.
5245 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5246 end_trigger ? : 'X');
5249 G.ifs = get_local_var_value("IFS");
5254 #if ENABLE_HUSH_INTERACTIVE
5255 input->promptmode = 0; /* PS1 */
5257 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5258 initialize_context(&ctx);
5263 const char *is_special;
5267 redir_type redir_style;
5270 /* dest.o_quoted = 1; - already is (see below) */
5271 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5274 /* We reached closing '"' */
5277 ch = i_getch(input);
5278 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5279 ch, ch, dest.o_escape);
5284 syntax_error_unterm_str("here document");
5287 if (done_word(&dest, &ctx)) {
5291 done_pipe(&ctx, PIPE_SEQ);
5293 /* If we got nothing... */
5294 /* (this makes bare "&" cmd a no-op.
5295 * bash says: "syntax error near unexpected token '&'") */
5296 if (pi->num_cmds == 0
5297 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5303 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5305 *pstring = ctx.as_string.data;
5307 o_free_unsafe(&ctx.as_string);
5310 debug_printf_parse("parse_stream return %p\n", pi);
5313 nommu_addchr(&ctx.as_string, ch);
5314 is_ifs = strchr(G.ifs, ch);
5315 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5316 "\\$\"" USE_HUSH_TICK("`") /* always special */
5319 if (!is_special && !is_ifs) { /* ordinary char */
5320 o_addQchr(&dest, ch);
5321 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5322 || dest.o_assignment == WORD_IS_KEYWORD)
5324 && is_well_formed_var_name(dest.data, '=')
5326 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5332 if (done_word(&dest, &ctx)) {
5336 #if ENABLE_HUSH_CASE
5337 /* "case ... in <newline> word) ..." -
5338 * newlines are ignored (but ';' wouldn't be) */
5339 if (ctx.command->argv == NULL
5340 && ctx.ctx_res_w == RES_MATCH
5345 /* Treat newline as a command separator. */
5346 done_pipe(&ctx, PIPE_SEQ);
5347 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5349 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5354 dest.o_assignment = MAYBE_ASSIGNMENT;
5356 /* note: if (is_ifs) continue;
5357 * will still trigger for us */
5360 if (end_trigger && end_trigger == ch
5361 && (heredoc_cnt == 0 || end_trigger != ';')
5364 /* This is technically valid:
5365 * { cat <<HERE; }; echo Ok
5369 * but we don't support this.
5370 * We require heredoc to be in enclosing {}/(),
5373 syntax_error_unterm_str("here document");
5376 if (done_word(&dest, &ctx)) {
5379 /* Disallow "{ cmd }" without semicolon or & */
5380 //debug_printf_parse("null pi %d\n", IS_NULL_PIPE(ctx.pipe))
5381 //debug_printf_parse("null cmd %d\n", IS_NULL_CMD(ctx.command))
5383 && !(IS_NULL_PIPE(ctx.pipe) && IS_NULL_CMD(ctx.command))
5385 syntax_error_unexpected_ch(ch);
5388 done_pipe(&ctx, PIPE_SEQ);
5389 dest.o_assignment = MAYBE_ASSIGNMENT;
5390 /* Do we sit outside of any if's, loops or case's? */
5392 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5396 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5398 *pstring = ctx.as_string.data;
5400 o_free_unsafe(&ctx.as_string);
5403 debug_printf_parse("parse_stream return %p: "
5404 "end_trigger char found\n",
5406 return ctx.list_head;
5414 next = i_peek(input);
5417 /* Catch <, > before deciding whether this word is
5418 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5421 redir_fd = redirect_opt_num(&dest);
5422 if (done_word(&dest, &ctx)) {
5425 redir_style = REDIRECT_OVERWRITE;
5427 redir_style = REDIRECT_APPEND;
5428 ch = i_getch(input);
5429 nommu_addchr(&ctx.as_string, ch);
5432 else if (next == '(') {
5433 syntax_error(">(process) not supported");
5437 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5439 continue; /* back to top of while (1) */
5441 redir_fd = redirect_opt_num(&dest);
5442 if (done_word(&dest, &ctx)) {
5445 redir_style = REDIRECT_INPUT;
5447 redir_style = REDIRECT_HEREDOC;
5449 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5450 ch = i_getch(input);
5451 nommu_addchr(&ctx.as_string, ch);
5452 } else if (next == '>') {
5453 redir_style = REDIRECT_IO;
5454 ch = i_getch(input);
5455 nommu_addchr(&ctx.as_string, ch);
5458 else if (next == '(') {
5459 syntax_error("<(process) not supported");
5463 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5465 continue; /* back to top of while (1) */
5468 if (dest.o_assignment == MAYBE_ASSIGNMENT
5469 /* check that we are not in word in "a=1 2>word b=1": */
5470 && !ctx.pending_redirect
5472 /* ch is a special char and thus this word
5473 * cannot be an assignment */
5474 dest.o_assignment = NOT_ASSIGNMENT;
5479 if (dest.length == 0) {
5482 if (ch == EOF || ch == '\n')
5485 /* note: we do not add it to &ctx.as_string */
5487 nommu_addchr(&ctx.as_string, '\n');
5489 o_addQchr(&dest, ch);
5494 syntax_error("\\<eof>");
5497 o_addchr(&dest, '\\');
5498 ch = i_getch(input);
5499 nommu_addchr(&ctx.as_string, ch);
5500 o_addchr(&dest, ch);
5501 /* Example: echo Hello \2>file
5502 * we need to know that word 2 is quoted */
5506 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5507 debug_printf_parse("parse_stream parse error: "
5508 "handle_dollar returned non-0\n");
5515 ch = i_getch(input);
5517 syntax_error_unterm_ch('\'');
5518 /*xfunc_die(); - redundant */
5520 nommu_addchr(&ctx.as_string, ch);
5523 if (dest.o_assignment == NOT_ASSIGNMENT)
5524 o_addqchr(&dest, ch);
5526 o_addchr(&dest, ch);
5531 is_in_dquote ^= 1; /* invert */
5532 if (dest.o_assignment == NOT_ASSIGNMENT)
5535 #if ENABLE_HUSH_TICK
5540 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5541 o_addchr(&dest, '`');
5545 add_till_backquote(&dest, input);
5547 o_addstr(&ctx.as_string, dest.data + pos);
5548 o_addchr(&ctx.as_string, '`');
5550 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5551 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5556 #if ENABLE_HUSH_CASE
5559 if (done_word(&dest, &ctx)) {
5562 done_pipe(&ctx, PIPE_SEQ);
5563 #if ENABLE_HUSH_CASE
5564 /* Eat multiple semicolons, detect
5565 * whether it means something special */
5570 ch = i_getch(input);
5571 nommu_addchr(&ctx.as_string, ch);
5572 if (ctx.ctx_res_w == RES_CASEI) {
5573 ctx.ctx_dsemicolon = 1;
5574 ctx.ctx_res_w = RES_MATCH;
5580 /* We just finished a cmd. New one may start
5581 * with an assignment */
5582 dest.o_assignment = MAYBE_ASSIGNMENT;
5585 if (done_word(&dest, &ctx)) {
5589 ch = i_getch(input);
5590 nommu_addchr(&ctx.as_string, ch);
5591 done_pipe(&ctx, PIPE_AND);
5593 done_pipe(&ctx, PIPE_BG);
5597 if (done_word(&dest, &ctx)) {
5600 #if ENABLE_HUSH_CASE
5601 if (ctx.ctx_res_w == RES_MATCH)
5602 break; /* we are in case's "word | word)" */
5604 if (next == '|') { /* || */
5605 ch = i_getch(input);
5606 nommu_addchr(&ctx.as_string, ch);
5607 done_pipe(&ctx, PIPE_OR);
5609 /* we could pick up a file descriptor choice here
5610 * with redirect_opt_num(), but bash doesn't do it.
5611 * "echo foo 2| cat" yields "foo 2". */
5616 #if ENABLE_HUSH_CASE
5617 /* "case... in [(]word)..." - skip '(' */
5618 if (ctx.ctx_res_w == RES_MATCH
5619 && ctx.command->argv == NULL /* not (word|(... */
5620 && dest.length == 0 /* not word(... */
5621 && dest.o_quoted == 0 /* not ""(... */
5627 if (parse_group(&dest, &ctx, input, ch) != 0) {
5632 #if ENABLE_HUSH_CASE
5633 if (ctx.ctx_res_w == RES_MATCH)
5637 /* proper use of this character is caught by end_trigger:
5638 * if we see {, we call parse_group(..., end_trigger='}')
5639 * and it will match } earlier (not here). */
5640 syntax_error_unexpected_ch(ch);
5644 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5650 struct parse_context *pctx;
5651 IF_HAS_KEYWORDS(struct parse_context *p2;)
5653 /* Clean up allocated tree.
5654 * Samples for finding leaks on syntax error recovery path.
5655 * Run them from interactive shell, watch pmap `pidof hush`.
5656 * while if false; then false; fi do break; done
5658 * while if false; then false; fi; do break; fi
5659 * Samples to catch leaks at execution:
5660 * while if (true | {true;}); then echo ok; fi; do break; done
5661 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5665 /* Update pipe/command counts,
5666 * otherwise freeing may miss some */
5667 done_pipe(pctx, PIPE_SEQ);
5668 debug_printf_clean("freeing list %p from ctx %p\n",
5669 pctx->list_head, pctx);
5670 debug_print_tree(pctx->list_head, 0);
5671 free_pipe_list(pctx->list_head);
5672 debug_printf_clean("freed list %p\n", pctx->list_head);
5674 o_free_unsafe(&pctx->as_string);
5676 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5680 IF_HAS_KEYWORDS(pctx = p2;)
5681 } while (HAS_KEYWORDS && pctx);
5682 /* Free text, clear all dest fields */
5684 /* If we are not in top-level parse, we return,
5685 * our caller will propagate error.
5687 if (end_trigger != ';') {
5695 /* Discard cached input, force prompt */
5697 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5702 /* Executing from string: eval, sh -c '...'
5703 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5704 * end_trigger controls how often we stop parsing
5705 * NUL: parse all, execute, return
5706 * ';': parse till ';' or newline, execute, repeat till EOF
5708 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5711 struct pipe *pipe_list;
5713 pipe_list = parse_stream(NULL, inp, end_trigger);
5714 if (!pipe_list) /* EOF */
5716 debug_print_tree(pipe_list, 0);
5717 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5718 run_and_free_list(pipe_list);
5722 static void parse_and_run_string(const char *s)
5724 struct in_str input;
5725 setup_string_in_str(&input, s);
5726 parse_and_run_stream(&input, '\0');
5729 static void parse_and_run_file(FILE *f)
5731 struct in_str input;
5732 setup_file_in_str(&input, f);
5733 parse_and_run_stream(&input, ';');
5736 /* Called a few times only (or even once if "sh -c") */
5737 static void block_signals(int second_time)
5742 mask = (1 << SIGQUIT);
5743 if (G_interactive_fd) {
5747 //TODO | (1 << SIGHUP)
5749 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5754 G.non_DFL_mask = mask;
5757 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5761 sigaddset(&G.blocked_set, sig);
5765 sigdelset(&G.blocked_set, SIGCHLD);
5767 sigprocmask(SIG_SETMASK, &G.blocked_set,
5768 second_time ? NULL : &G.inherited_set);
5769 /* POSIX allows shell to re-enable SIGCHLD
5770 * even if it was SIG_IGN on entry */
5771 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5773 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5778 static void maybe_set_to_sigexit(int sig)
5780 void (*handler)(int);
5781 /* non_DFL_mask'ed signals are, well, masked,
5782 * no need to set handler for them.
5784 if (!((G.non_DFL_mask >> sig) & 1)) {
5785 handler = signal(sig, sigexit);
5786 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5787 signal(sig, handler);
5790 /* Set handlers to restore tty pgrp and exit */
5791 static void set_fatal_handlers(void)
5793 /* We _must_ restore tty pgrp on fatal signals */
5795 maybe_set_to_sigexit(SIGILL );
5796 maybe_set_to_sigexit(SIGFPE );
5797 maybe_set_to_sigexit(SIGBUS );
5798 maybe_set_to_sigexit(SIGSEGV);
5799 maybe_set_to_sigexit(SIGTRAP);
5800 } /* else: hush is perfect. what SEGV? */
5801 maybe_set_to_sigexit(SIGABRT);
5802 /* bash 3.2 seems to handle these just like 'fatal' ones */
5803 maybe_set_to_sigexit(SIGPIPE);
5804 maybe_set_to_sigexit(SIGALRM);
5805 //TODO: disable and move down when proper SIGHUP handling is added
5806 maybe_set_to_sigexit(SIGHUP );
5807 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5808 * if we aren't interactive... but in this case
5809 * we never want to restore pgrp on exit, and this fn is not called */
5810 /*maybe_set_to_sigexit(SIGTERM);*/
5811 /*maybe_set_to_sigexit(SIGINT );*/
5815 static int set_mode(const char cstate, const char mode)
5817 int state = (cstate == '-' ? 1 : 0);
5819 case 'n': G.fake_mode = state; break;
5820 case 'x': /*G.debug_mode = state;*/ break;
5821 default: return EXIT_FAILURE;
5823 return EXIT_SUCCESS;
5826 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5827 int hush_main(int argc, char **argv)
5829 static const struct variable const_shell_ver = {
5831 .varstr = (char*)hush_version_str,
5832 .max_len = 1, /* 0 can provoke free(name) */
5836 int signal_mask_is_inited = 0;
5839 struct variable *cur_var;
5842 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5843 G.last_exitcode = EXIT_SUCCESS;
5845 G.argv0_for_re_execing = argv[0];
5847 /* Deal with HUSH_VERSION */
5848 G.shell_ver = const_shell_ver; /* copying struct here */
5849 G.top_var = &G.shell_ver;
5850 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5851 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5852 /* Initialize our shell local variables with the values
5853 * currently living in the environment */
5854 cur_var = G.top_var;
5857 char *value = strchr(*e, '=');
5858 if (value) { /* paranoia */
5859 cur_var->next = xzalloc(sizeof(*cur_var));
5860 cur_var = cur_var->next;
5861 cur_var->varstr = *e;
5862 cur_var->max_len = strlen(*e);
5863 cur_var->flg_export = 1;
5867 debug_printf_env("putenv '%s'\n", hush_version_str);
5868 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5869 #if ENABLE_FEATURE_EDITING
5870 G.line_input_state = new_line_input_t(FOR_SHELL);
5872 G.global_argc = argc;
5873 G.global_argv = argv;
5874 /* Initialize some more globals to non-zero values */
5876 #if ENABLE_HUSH_INTERACTIVE
5877 if (ENABLE_FEATURE_EDITING)
5878 cmdedit_set_initial_prompt();
5882 if (setjmp(die_jmp)) {
5883 /* xfunc has failed! die die die */
5884 /* no EXIT traps, this is an escape hatch! */
5886 hush_exit(xfunc_error_retval);
5889 /* Shell is non-interactive at first. We need to call
5890 * block_signals(0) if we are going to execute "sh <script>",
5891 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5892 * If we later decide that we are interactive, we run block_signals(0)
5893 * (or re-run block_signals(1) if we ran block_signals(0) before)
5894 * in order to intercept (more) signals.
5898 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5900 opt = getopt(argc, argv, "c:xins"
5903 # if ENABLE_HUSH_FUNCTIONS
5913 G.root_pid = getpid();
5914 G.global_argv = argv + optind;
5915 if (!argv[optind]) {
5916 /* -c 'script' (no params): prevent empty $0 */
5917 *--G.global_argv = argv[0];
5919 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5920 G.global_argc = argc - optind;
5921 block_signals(0); /* 0: called 1st time */
5922 parse_and_run_string(optarg);
5925 /* Well, we cannot just declare interactiveness,
5926 * we have to have some stuff (ctty, etc) */
5927 /* G_interactive_fd++; */
5930 /* "-s" means "read from stdin", but this is how we always
5931 * operate, so simply do nothing here. */
5934 case '<': /* "big heredoc" support */
5935 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5938 G.root_pid = bb_strtou(optarg, &optarg, 16);
5940 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5942 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5943 # if ENABLE_HUSH_LOOPS
5945 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5950 set_local_var(xstrdup(optarg), 0, opt == 'R');
5952 # if ENABLE_HUSH_FUNCTIONS
5954 struct function *funcp = new_function(optarg);
5955 /* funcp->name is already set to optarg */
5956 /* funcp->body is set to NULL. It's a special case. */
5957 funcp->body_as_string = argv[optind];
5965 if (!set_mode('-', opt))
5969 fprintf(stderr, "Usage: sh [FILE]...\n"
5970 " or: sh -c command [args]...\n\n");
5976 } /* option parsing loop */
5979 G.root_pid = getpid();
5981 /* If we are login shell... */
5982 if (argv[0] && argv[0][0] == '-') {
5984 /* XXX what should argv be while sourcing /etc/profile? */
5985 debug_printf("sourcing /etc/profile\n");
5986 input = fopen_for_read("/etc/profile");
5987 if (input != NULL) {
5988 close_on_exec_on(fileno(input));
5989 block_signals(0); /* 0: called 1st time */
5990 signal_mask_is_inited = 1;
5991 parse_and_run_file(input);
5994 /* bash: after sourcing /etc/profile,
5995 * tries to source (in the given order):
5996 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5997 * stopping of first found. --noprofile turns this off.
5998 * bash also sources ~/.bash_logout on exit.
5999 * If called as sh, skips .bash_XXX files.
6006 * "bash <script>" (which is never interactive (unless -i?))
6007 * sources $BASH_ENV here (without scanning $PATH).
6008 * If called as sh, does the same but with $ENV.
6010 debug_printf("running script '%s'\n", argv[optind]);
6011 G.global_argv = argv + optind;
6012 G.global_argc = argc - optind;
6013 input = xfopen_for_read(argv[optind]);
6014 close_on_exec_on(fileno(input));
6015 if (!signal_mask_is_inited)
6016 block_signals(0); /* 0: called 1st time */
6017 parse_and_run_file(input);
6018 #if ENABLE_FEATURE_CLEAN_UP
6024 /* Up to here, shell was non-interactive. Now it may become one.
6025 * NB: don't forget to (re)run block_signals(0/1) as needed.
6028 /* A shell is interactive if the '-i' flag was given, or if all of
6029 * the following conditions are met:
6031 * no arguments remaining or the -s flag given
6032 * standard input is a terminal
6033 * standard output is a terminal
6034 * Refer to Posix.2, the description of the 'sh' utility.
6037 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6038 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6039 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6040 //TODO: "interactive" and "have job control" are two different things.
6041 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6042 //should stay on! Currently, we mix these into one.
6043 if (G.saved_tty_pgrp >= 0) {
6044 /* try to dup stdin to high fd#, >= 255 */
6045 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6046 if (G_interactive_fd < 0) {
6047 /* try to dup to any fd */
6048 G_interactive_fd = dup(STDIN_FILENO);
6049 if (G_interactive_fd < 0)
6051 G_interactive_fd = 0;
6053 // TODO: track & disallow any attempts of user
6054 // to (inadvertently) close/redirect it
6057 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6058 if (G_interactive_fd) {
6061 /* We are indeed interactive shell, and we will perform
6062 * job control. Setting up for that. */
6064 close_on_exec_on(G_interactive_fd);
6065 /* If we were run as 'hush &', sleep until we are
6066 * in the foreground (tty pgrp == our pgrp).
6067 * If we get started under a job aware app (like bash),
6068 * make sure we are now in charge so we don't fight over
6069 * who gets the foreground */
6071 shell_pgrp = getpgrp();
6072 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6073 if (G.saved_tty_pgrp == shell_pgrp)
6075 /* send TTIN to ourself (should stop us) */
6076 kill(- shell_pgrp, SIGTTIN);
6078 /* Block some signals */
6079 block_signals(signal_mask_is_inited);
6080 /* Set other signals to restore saved_tty_pgrp */
6081 set_fatal_handlers();
6082 /* Put ourselves in our own process group */
6083 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6084 /* Grab control of the terminal */
6085 tcsetpgrp(G_interactive_fd, getpid());
6086 /* -1 is special - makes xfuncs longjmp, not exit
6087 * (we reset die_sleep = 0 whereever we [v]fork) */
6088 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6089 } else if (!signal_mask_is_inited) {
6090 block_signals(0); /* 0: called 1st time */
6091 } /* else: block_signals(0) was done before */
6092 #elif ENABLE_HUSH_INTERACTIVE
6093 /* No job control compiled in, only prompt/line editing */
6094 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6095 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6096 if (G_interactive_fd < 0) {
6097 /* try to dup to any fd */
6098 G_interactive_fd = dup(STDIN_FILENO);
6099 if (G_interactive_fd < 0)
6101 G_interactive_fd = 0;
6104 if (G_interactive_fd) {
6105 close_on_exec_on(G_interactive_fd);
6106 block_signals(signal_mask_is_inited);
6107 } else if (!signal_mask_is_inited) {
6111 /* We have interactiveness code disabled */
6112 if (!signal_mask_is_inited) {
6117 * if interactive but not a login shell, sources ~/.bashrc
6118 * (--norc turns this off, --rcfile <file> overrides)
6121 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6122 printf("\n\n%s hush - the humble shell\n", bb_banner);
6123 printf("Enter 'help' for a list of built-in commands.\n\n");
6126 parse_and_run_file(stdin);
6129 #if ENABLE_FEATURE_CLEAN_UP
6130 if (G.cwd != bb_msg_unknown)
6132 cur_var = G.top_var->next;
6134 struct variable *tmp = cur_var;
6135 if (!cur_var->max_len)
6136 free(cur_var->varstr);
6137 cur_var = cur_var->next;
6141 hush_exit(G.last_exitcode);
6146 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6147 int lash_main(int argc, char **argv)
6149 //bb_error_msg("lash is deprecated, please use hush instead");
6150 return hush_main(argc, argv);
6158 static int builtin_trap(char **argv)
6165 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6169 /* No args: print all trapped. This isn't 100% correct as we
6170 * should be escaping the cmd so that it can be pasted back in
6172 for (i = 0; i < NSIG; ++i)
6174 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
6175 return EXIT_SUCCESS;
6180 /* If first arg is decimal: reset all specified signals */
6181 sig = bb_strtou(*argv, NULL, 10);
6187 sig = get_signum(*argv++);
6188 if (sig < 0 || sig >= NSIG) {
6190 /* Mimic bash message exactly */
6191 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
6196 G.traps[sig] = xstrdup(new_cmd);
6198 debug_printf("trap: setting SIG%s (%i) to '%s'",
6199 get_signame(sig), sig, G.traps[sig]);
6201 /* There is no signal for 0 (EXIT) */
6206 sigaddset(&G.blocked_set, sig);
6208 /* There was a trap handler, we are removing it
6209 * (if sig has non-DFL handling,
6210 * we don't need to do anything) */
6211 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6213 sigdelset(&G.blocked_set, sig);
6215 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6220 /* First arg is "-": reset all specified to default */
6221 /* First arg is "": ignore all specified */
6222 /* Everything else: execute first arg upon signal */
6224 bb_error_msg("trap: invalid arguments");
6225 return EXIT_FAILURE;
6227 if (NOT_LONE_DASH(*argv))
6233 static int builtin_true(char **argv UNUSED_PARAM)
6238 static int builtin_test(char **argv)
6245 return test_main(argc, argv - argc);
6248 static int builtin_echo(char **argv)
6255 return echo_main(argc, argv - argc);
6258 static int builtin_eval(char **argv)
6260 int rcode = EXIT_SUCCESS;
6263 char *str = expand_strvec_to_string(argv);
6265 * eval "echo Hi; done" ("done" is syntax error):
6266 * "echo Hi" will not execute too.
6268 parse_and_run_string(str);
6270 rcode = G.last_exitcode;
6275 static int builtin_cd(char **argv)
6277 const char *newdir = argv[1];
6278 if (newdir == NULL) {
6279 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6280 * bash says "bash: cd: HOME not set" and does nothing
6283 newdir = getenv("HOME") ? : "/";
6285 if (chdir(newdir)) {
6286 /* Mimic bash message exactly */
6287 bb_perror_msg("cd: %s", newdir);
6288 return EXIT_FAILURE;
6291 return EXIT_SUCCESS;
6294 static int builtin_exec(char **argv)
6296 if (*++argv == NULL)
6297 return EXIT_SUCCESS; /* bash does this */
6302 // FIXME: if exec fails, bash does NOT exit! We do...
6303 pseudo_exec_argv(&dummy, argv, 0, NULL);
6308 static int builtin_exit(char **argv)
6310 debug_printf_exec("%s()\n", __func__);
6311 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6312 //puts("exit"); /* bash does it */
6313 // TODO: warn if we have background jobs: "There are stopped jobs"
6314 // On second consecutive 'exit', exit anyway.
6315 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6317 /* note: EXIT trap is run by hush_exit */
6318 if (*++argv == NULL)
6319 hush_exit(G.last_exitcode);
6320 /* mimic bash: exit 123abc == exit 255 + error msg */
6321 xfunc_error_retval = 255;
6322 /* bash: exit -2 == exit 254, no error msg */
6323 hush_exit(xatoi(*argv) & 0xff);
6326 static int builtin_export(char **argv)
6328 if (*++argv == NULL) {
6335 /* ash emits: export VAR='VAL'
6336 * bash: declare -x VAR="VAL"
6337 * we follow ash example */
6338 const char *s = *e++;
6339 const char *p = strchr(s, '=');
6341 if (!p) /* wtf? take next variable */
6344 printf("export %.*s", (int)(p - s) + 1, s);
6348 p = strchrnul(s, '\'');
6350 printf("'%.*s'", (int)(p - s), s);
6355 /* s points to '; print ''...'''" */
6357 do putchar('\''); while (*++s == '\'');
6365 return EXIT_SUCCESS;
6372 value = strchr(name, '=');
6374 /* They are exporting something without a =VALUE */
6375 struct variable *var;
6377 var = get_local_var(name);
6379 var->flg_export = 1;
6380 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6381 putenv(var->varstr);
6383 /* bash does not return an error when trying to export
6384 * an undefined variable. Do likewise. */
6387 set_local_var(xstrdup(name), 1, 0);
6390 return EXIT_SUCCESS;
6394 /* built-in 'fg' and 'bg' handler */
6395 static int builtin_fg_bg(char **argv)
6400 if (!G_interactive_fd)
6401 return EXIT_FAILURE;
6402 /* If they gave us no args, assume they want the last backgrounded task */
6404 for (pi = G.job_list; pi; pi = pi->next) {
6405 if (pi->jobid == G.last_jobid) {
6409 bb_error_msg("%s: no current job", argv[0]);
6410 return EXIT_FAILURE;
6412 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6413 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6414 return EXIT_FAILURE;
6416 for (pi = G.job_list; pi; pi = pi->next) {
6417 if (pi->jobid == jobnum) {
6421 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6422 return EXIT_FAILURE;
6424 // TODO: bash prints a string representation
6425 // of job being foregrounded (like "sleep 1 | cat")
6426 if (argv[0][0] == 'f') {
6427 /* Put the job into the foreground. */
6428 tcsetpgrp(G_interactive_fd, pi->pgrp);
6431 /* Restart the processes in the job */
6432 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6433 for (i = 0; i < pi->num_cmds; i++) {
6434 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6435 pi->cmds[i].is_stopped = 0;
6437 pi->stopped_cmds = 0;
6439 i = kill(- pi->pgrp, SIGCONT);
6441 if (errno == ESRCH) {
6442 delete_finished_bg_job(pi);
6443 return EXIT_SUCCESS;
6445 bb_perror_msg("kill (SIGCONT)");
6448 if (argv[0][0] == 'f') {
6450 return checkjobs_and_fg_shell(pi);
6452 return EXIT_SUCCESS;
6456 #if ENABLE_HUSH_HELP
6457 static int builtin_help(char **argv UNUSED_PARAM)
6459 const struct built_in_command *x;
6462 "Built-in commands:\n"
6463 "------------------\n");
6464 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6465 printf("%s\t%s\n", x->cmd, x->descr);
6468 return EXIT_SUCCESS;
6473 static int builtin_jobs(char **argv UNUSED_PARAM)
6476 const char *status_string;
6478 for (job = G.job_list; job; job = job->next) {
6479 if (job->alive_cmds == job->stopped_cmds)
6480 status_string = "Stopped";
6482 status_string = "Running";
6484 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6486 return EXIT_SUCCESS;
6491 static int builtin_memleak(char **argv UNUSED_PARAM)
6496 /* Crude attempt to find where "free memory" starts,
6497 * sans fragmentation. */
6499 l = (unsigned long)p;
6502 if (l < (unsigned long)p) l = (unsigned long)p;
6505 if (!G.memleak_value)
6506 G.memleak_value = l;
6508 l -= G.memleak_value;
6515 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6520 static int builtin_pwd(char **argv UNUSED_PARAM)
6523 return EXIT_SUCCESS;
6526 static int builtin_read(char **argv)
6529 const char *name = "REPLY";
6533 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6534 * and _after_ that_ it will complain */
6535 if (!is_well_formed_var_name(name, '\0')) {
6536 /* Mimic bash message */
6537 bb_error_msg("read: '%s': not a valid identifier", name);
6542 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6544 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6545 return set_local_var(string, 0, 0);
6548 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6549 * built-in 'set' handler
6551 * set [-abCefhmnuvx] [-o option] [argument...]
6552 * set [+abCefhmnuvx] [+o option] [argument...]
6553 * set -- [argument...]
6556 * Implementations shall support the options in both their hyphen and
6557 * plus-sign forms. These options can also be specified as options to sh.
6559 * Write out all variables and their values: set
6560 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6561 * Turn on the -x and -v options: set -xv
6562 * Unset all positional parameters: set --
6563 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6564 * Set the positional parameters to the expansion of x, even if x expands
6565 * with a leading '-' or '+': set -- $x
6567 * So far, we only support "set -- [argument...]" and some of the short names.
6569 static int builtin_set(char **argv)
6572 char **pp, **g_argv;
6573 char *arg = *++argv;
6577 for (e = G.top_var; e; e = e->next)
6579 return EXIT_SUCCESS;
6583 if (!strcmp(arg, "--")) {
6587 if (arg[0] != '+' && arg[0] != '-')
6589 for (n = 1; arg[n]; ++n)
6590 if (set_mode(arg[0], arg[n]))
6592 } while ((arg = *++argv) != NULL);
6593 /* Now argv[0] is 1st argument */
6596 return EXIT_SUCCESS;
6599 /* NB: G.global_argv[0] ($0) is never freed/changed */
6600 g_argv = G.global_argv;
6601 if (G.global_args_malloced) {
6607 G.global_args_malloced = 1;
6608 pp = xzalloc(sizeof(pp[0]) * 2);
6609 pp[0] = g_argv[0]; /* retain $0 */
6612 /* This realloc's G.global_argv */
6613 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6620 return EXIT_SUCCESS;
6622 /* Nothing known, so abort */
6624 bb_error_msg("set: %s: invalid option", arg);
6625 return EXIT_FAILURE;
6628 static int builtin_shift(char **argv)
6634 if (n >= 0 && n < G.global_argc) {
6635 if (G.global_args_malloced) {
6638 free(G.global_argv[m++]);
6641 memmove(&G.global_argv[1], &G.global_argv[n+1],
6642 G.global_argc * sizeof(G.global_argv[0]));
6643 return EXIT_SUCCESS;
6645 return EXIT_FAILURE;
6648 static int builtin_source(char **argv)
6652 if (*++argv == NULL)
6653 return EXIT_FAILURE;
6655 /* XXX search through $PATH is missing */
6656 input = fopen_or_warn(*argv, "r");
6658 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6659 return EXIT_FAILURE;
6661 close_on_exec_on(fileno(input));
6663 /* Now run the file */
6665 /* XXX argv and argc are broken; need to save old G.global_argv
6666 * (pointer only is OK!) on this stack frame,
6667 * set G.global_argv=argv+1, recurse, and restore. */
6668 parse_and_run_file(input);
6670 return G.last_exitcode;
6673 static int builtin_umask(char **argv)
6676 const char *arg = argv[1];
6678 //TODO: umask may take chmod-like symbolic masks
6679 new_umask = bb_strtou(arg, NULL, 8);
6681 //Message? bash examples:
6682 //bash: umask: 'q': invalid symbolic mode operator
6683 //bash: umask: 999: octal number out of range
6684 return EXIT_FAILURE;
6687 new_umask = umask(0);
6688 printf("%.3o\n", (unsigned) new_umask);
6689 /* fall through and restore new_umask which we set to 0 */
6692 return EXIT_SUCCESS;
6695 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6696 static int builtin_unset(char **argv)
6702 return EXIT_SUCCESS;
6705 if (argv[0][0] == '-') {
6706 switch (argv[0][1]) {
6712 bb_error_msg("unset: %s: invalid option", *argv);
6713 return EXIT_FAILURE;
6715 //TODO: disallow "unset -vf ..." too
6722 if (unset_local_var(*argv)) {
6723 /* unset <nonexistent_var> doesn't fail.
6724 * Error is when one tries to unset RO var.
6725 * Message was printed by unset_local_var. */
6729 //#if ENABLE_HUSH_FUNCTIONS
6731 // unset_local_func(*argv);
6739 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6740 static int builtin_wait(char **argv)
6742 int ret = EXIT_SUCCESS;
6745 if (*++argv == NULL) {
6746 /* Don't care about wait results */
6747 /* Note 1: must wait until there are no more children */
6748 /* Note 2: must be interruptible */
6750 * $ sleep 3 & sleep 6 & wait
6755 * $ sleep 3 & sleep 6 & wait
6759 * ^C <-- after ~4 sec from keyboard
6762 sigaddset(&G.blocked_set, SIGCHLD);
6763 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6766 if (errno == ECHILD)
6768 /* Wait for SIGCHLD or any other signal of interest */
6769 /* sigtimedwait with infinite timeout: */
6770 sig = sigwaitinfo(&G.blocked_set, NULL);
6772 sig = check_and_run_traps(sig);
6773 if (sig && sig != SIGCHLD) { /* see note 2 */
6779 sigdelset(&G.blocked_set, SIGCHLD);
6780 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6784 /* This is probably buggy wrt interruptible-ness */
6786 pid_t pid = bb_strtou(*argv, NULL, 10);
6788 /* mimic bash message */
6789 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6790 return EXIT_FAILURE;
6792 if (waitpid(pid, &status, 0) == pid) {
6793 if (WIFSIGNALED(status))
6794 ret = 128 + WTERMSIG(status);
6795 else if (WIFEXITED(status))
6796 ret = WEXITSTATUS(status);
6800 bb_perror_msg("wait %s", *argv);
6809 #if ENABLE_HUSH_LOOPS
6810 static int builtin_break(char **argv)
6812 if (G.depth_of_loop == 0) {
6813 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6814 return EXIT_SUCCESS; /* bash compat */
6816 G.flag_break_continue++; /* BC_BREAK = 1 */
6817 G.depth_break_continue = 1;
6819 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6820 if (errno || !G.depth_break_continue || argv[2]) {
6821 bb_error_msg("%s: bad arguments", argv[0]);
6822 G.flag_break_continue = BC_BREAK;
6823 G.depth_break_continue = UINT_MAX;
6826 if (G.depth_of_loop < G.depth_break_continue)
6827 G.depth_break_continue = G.depth_of_loop;
6828 return EXIT_SUCCESS;
6831 static int builtin_continue(char **argv)
6833 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6834 return builtin_break(argv);