1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
45 * Bash stuff (maybe optionally enable?):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
52 * grep for "TODO" and fix (some of them are easy)
53 * $var refs in function do not pick up values set by "var=val func"
55 * follow IFS rules more precisely, including update semantics
57 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
59 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
61 /* #include <dmalloc.h> */
68 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
73 #define LEAK_HUNTING 0
74 #define BUILD_AS_NOMMU 0
75 /* Enable/disable sanity checks. Ok to enable in production,
76 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
77 * Keeping 1 for now even in released versions.
80 /* Slightly bigger (+200 bytes), but faster hush.
81 * So far it only enables a trick with counting SIGCHLDs and forks,
82 * which allows us to do fewer waitpid's.
83 * (we can detect a case where neither forks were done nor SIGCHLDs happened
84 * and therefore waitpid will return the same result as last time)
86 #define ENABLE_HUSH_FAST 0
94 # define USE_FOR_NOMMU(...) __VA_ARGS__
95 # define USE_FOR_MMU(...)
98 #if defined SINGLE_APPLET_MAIN
99 /* STANDALONE does not make sense, and won't compile */
100 # undef CONFIG_FEATURE_SH_STANDALONE
101 # undef ENABLE_FEATURE_SH_STANDALONE
102 # undef IF_FEATURE_SH_STANDALONE
103 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
104 # define ENABLE_FEATURE_SH_STANDALONE 0
105 # define IF_FEATURE_SH_STANDALONE(...)
106 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
109 #if !ENABLE_HUSH_INTERACTIVE
110 # undef ENABLE_FEATURE_EDITING
111 # define ENABLE_FEATURE_EDITING 0
112 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
113 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
116 /* Do we support ANY keywords? */
117 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
118 # define HAS_KEYWORDS 1
119 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
120 # define IF_HAS_NO_KEYWORDS(...)
122 # define HAS_KEYWORDS 0
123 # define IF_HAS_KEYWORDS(...)
124 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
127 /* If you comment out one of these below, it will be #defined later
128 * to perform debug printfs to stderr: */
129 #define debug_printf(...) do {} while (0)
130 /* Finer-grained debug switches */
131 #define debug_printf_parse(...) do {} while (0)
132 #define debug_print_tree(a, b) do {} while (0)
133 #define debug_printf_exec(...) do {} while (0)
134 #define debug_printf_env(...) do {} while (0)
135 #define debug_printf_jobs(...) do {} while (0)
136 #define debug_printf_expand(...) do {} while (0)
137 #define debug_printf_glob(...) do {} while (0)
138 #define debug_printf_list(...) do {} while (0)
139 #define debug_printf_subst(...) do {} while (0)
140 #define debug_printf_clean(...) do {} while (0)
142 #define ERR_PTR ((void*)(long)1)
144 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
146 #define SPECIAL_VAR_SYMBOL 3
150 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
152 /* This supports saving pointers malloced in vfork child,
153 * to be freed in the parent.
156 typedef struct nommu_save_t {
158 struct variable *old_vars;
160 char **argv_from_re_execing;
164 /* The descrip member of this structure is only used to make
165 * debugging output pretty */
166 static const struct {
168 signed char default_fd;
172 { O_RDONLY, 0, "<" },
173 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
174 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
175 { O_RDONLY, 0, "<<" },
176 { O_CREAT|O_RDWR, 1, "<>" },
177 /* Should not be needed. Bogus default_fd helps in debugging */
178 /* { O_RDONLY, 77, "<<" }, */
181 typedef enum reserved_style {
190 #if ENABLE_HUSH_LOOPS
197 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
202 /* three pseudo-keywords support contrived "case" syntax: */
203 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
204 RES_MATCH , /* "word)" */
205 RES_CASE_BODY, /* "this command is inside CASE" */
212 typedef struct o_string {
214 int length; /* position where data is appended */
216 /* Protect newly added chars against globbing
217 * (by prepending \ to *, ?, [, \) */
220 /* At least some part of the string was inside '' or "",
221 * possibly empty one: word"", wo''rd etc. */
223 smallint has_empty_slot;
224 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
227 MAYBE_ASSIGNMENT = 0,
228 DEFINITELY_ASSIGNMENT = 1,
230 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
232 /* Used for initialization: o_string foo = NULL_O_STRING; */
233 #define NULL_O_STRING { NULL }
235 /* I can almost use ordinary FILE*. Is open_memstream() universally
236 * available? Where is it documented? */
237 typedef struct in_str {
239 /* eof_flag=1: last char in ->p is really an EOF */
240 char eof_flag; /* meaningless if ->p == NULL */
242 #if ENABLE_HUSH_INTERACTIVE
244 smallint promptmode; /* 0: PS1, 1: PS2 */
247 int (*get) (struct in_str *);
248 int (*peek) (struct in_str *);
250 #define i_getch(input) ((input)->get(input))
251 #define i_peek(input) ((input)->peek(input))
253 struct redir_struct {
254 struct redir_struct *next;
255 char *rd_filename; /* filename */
256 int rd_fd; /* fd to redirect */
257 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
259 smallint rd_type; /* (enum redir_type) */
260 /* note: for heredocs, rd_filename contains heredoc delimiter,
261 * and subsequently heredoc itself; and rd_dup is a bitmask:
262 * 1: do we need to trim leading tabs?
263 * 2: is heredoc quoted (<<'delim' syntax) ?
266 typedef enum redir_type {
267 REDIRECT_INVALID = 0,
269 REDIRECT_OVERWRITE = 2,
271 REDIRECT_HEREDOC = 4,
273 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
276 REDIRFD_SYNTAX_ERR = -2,
277 REDIRFD_TO_FILE = -1,
278 /* otherwise, rd_fd is redirected to rd_dup */
280 HEREDOC_SKIPTABS = 1,
286 pid_t pid; /* 0 if exited */
287 int assignment_cnt; /* how many argv[i] are assignments? */
288 smallint is_stopped; /* is the command currently running? */
289 smallint grp_type; /* GRP_xxx */
291 #define GRP_SUBSHELL 1
292 #if ENABLE_HUSH_FUNCTIONS
293 # define GRP_FUNCTION 2
295 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
298 char *group_as_string;
300 #if ENABLE_HUSH_FUNCTIONS
301 struct function *child_func;
302 /* This field is used to prevent a bug here:
303 * while...do f1() {a;}; f1; f1 {b;}; f1; done
304 * When we execute "f1() {a;}" cmd, we create new function and clear
305 * cmd->group, cmd->group_as_string, cmd->argv[0].
306 * when we execute "f1 {b;}", we notice that f1 exists,
307 * and that it's "parent cmd" struct is still "alive",
308 * we put those fields back into cmd->xxx
309 * (struct function has ->parent_cmd ptr to facilitate that).
310 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
311 * Without this trick, loop would execute a;b;b;b;...
312 * instead of correct sequence a;b;a;b;...
313 * When command is freed, it severs the link
314 * (sets ->child_func->parent_cmd to NULL).
317 char **argv; /* command name and arguments */
318 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
319 * and on execution these are substituted with their values.
320 * Substitution can make _several_ words out of one argv[n]!
321 * Example: argv[0]=='.^C*^C.' here: echo .$*.
322 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
324 struct redir_struct *redirects; /* I/O redirections */
326 /* Is there anything in this command at all? */
327 #define IS_NULL_CMD(cmd) \
328 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
333 int num_cmds; /* total number of commands in pipe */
334 int alive_cmds; /* number of commands running (not exited) */
335 int stopped_cmds; /* number of commands alive, but stopped */
337 int jobid; /* job number */
338 pid_t pgrp; /* process group ID for the job */
339 char *cmdtext; /* name of job */
341 struct command *cmds; /* array of commands in pipe */
342 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
343 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
344 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
346 typedef enum pipe_style {
352 /* Is there anything in this pipe at all? */
353 #define IS_NULL_PIPE(pi) \
354 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
356 /* This holds pointers to the various results of parsing */
357 struct parse_context {
358 /* linked list of pipes */
359 struct pipe *list_head;
360 /* last pipe (being constructed right now) */
362 /* last command in pipe (being constructed right now) */
363 struct command *command;
364 /* last redirect in command->redirects list */
365 struct redir_struct *pending_redirect;
371 smallint ctx_inverted; /* "! cmd | cmd" */
373 smallint ctx_dsemicolon; /* ";;" seen */
375 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
377 /* group we are enclosed in:
378 * example: "if pipe1; pipe2; then pipe3; fi"
379 * when we see "if" or "then", we malloc and copy current context,
380 * and make ->stack point to it. then we parse pipeN.
381 * when closing "then" / fi" / whatever is found,
382 * we move list_head into ->stack->command->group,
383 * copy ->stack into current context, and delete ->stack.
384 * (parsing of { list } and ( list ) doesn't use this method)
386 struct parse_context *stack;
390 /* On program start, environ points to initial environment.
391 * putenv adds new pointers into it, unsetenv removes them.
392 * Neither of these (de)allocates the strings.
393 * setenv allocates new strings in malloc space and does putenv,
394 * and thus setenv is unusable (leaky) for shell's purposes */
395 #define setenv(...) setenv_is_leaky_dont_use()
397 struct variable *next;
398 char *varstr; /* points to "name=" portion */
399 int max_len; /* if > 0, name is part of initial env; else name is malloced */
400 smallint flg_export; /* putenv should be done on this var */
401 smallint flg_read_only;
409 #if ENABLE_HUSH_FUNCTIONS
411 struct function *next;
413 struct command *parent_cmd;
416 char *body_as_string;
422 /* "Globals" within this file */
423 /* Sorted roughly by size (smaller offsets == smaller code) */
425 /* interactive_fd != 0 means we are an interactive shell.
426 * If we are, then saved_tty_pgrp can also be != 0, meaning
427 * that controlling tty is available. With saved_tty_pgrp == 0,
428 * job control still works, but terminal signals
429 * (^C, ^Z, ^Y, ^\) won't work at all, and background
430 * process groups can only be created with "cmd &".
431 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
432 * to give tty to the foreground process group,
433 * and will take it back when the group is stopped (^Z)
436 #if ENABLE_HUSH_INTERACTIVE
437 /* 'interactive_fd' is a fd# open to ctty, if we have one
438 * _AND_ if we decided to act interactively */
442 # define G_interactive_fd (G.interactive_fd)
444 # define G_interactive_fd 0
446 #if ENABLE_FEATURE_EDITING
447 line_input_t *line_input_state;
454 pid_t saved_tty_pgrp;
455 struct pipe *job_list;
456 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
458 # define G_saved_tty_pgrp 0
460 smallint flag_SIGINT;
461 #if ENABLE_HUSH_LOOPS
462 smallint flag_break_continue;
464 #if ENABLE_HUSH_FUNCTIONS
465 /* 0: outside of a function (or sourced file)
466 * -1: inside of a function, ok to use return builtin
467 * 1: return is invoked, skip all till end of func
469 smallint flag_return_in_progress;
472 smallint exiting; /* used to prevent EXIT trap recursion */
473 /* These four support $?, $#, and $1 */
474 smalluint last_exitcode;
475 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
476 smalluint global_args_malloced;
477 /* how many non-NULL argv's we have. NB: $# + 1 */
481 char *argv0_for_re_execing;
483 #if ENABLE_HUSH_LOOPS
484 unsigned depth_break_continue;
485 unsigned depth_of_loop;
489 struct variable *top_var; /* = &G.shell_ver (set in main()) */
490 struct variable shell_ver;
491 #if ENABLE_HUSH_FUNCTIONS
492 struct function *top_func;
494 /* Signal and trap handling */
496 unsigned count_SIGCHLD;
497 unsigned handled_SIGCHLD;
498 smallint we_have_children;
500 /* which signals have non-DFL handler (even with no traps set)? */
501 unsigned non_DFL_mask;
502 char **traps; /* char *traps[NSIG] */
503 sigset_t blocked_set;
504 sigset_t inherited_set;
506 unsigned long memleak_value;
509 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
511 #define G (*ptr_to_globals)
512 /* Not #defining name to G.name - this quickly gets unwieldy
513 * (too many defines). Also, I actually prefer to see when a variable
514 * is global, thus "G." prefix is a useful hint */
515 #define INIT_G() do { \
516 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
520 /* Function prototypes for builtins */
521 static int builtin_cd(char **argv);
522 static int builtin_echo(char **argv);
523 static int builtin_eval(char **argv);
524 static int builtin_exec(char **argv);
525 static int builtin_exit(char **argv);
526 static int builtin_export(char **argv);
528 static int builtin_fg_bg(char **argv);
529 static int builtin_jobs(char **argv);
532 static int builtin_help(char **argv);
535 static int builtin_memleak(char **argv);
537 static int builtin_pwd(char **argv);
538 static int builtin_read(char **argv);
539 static int builtin_set(char **argv);
540 static int builtin_shift(char **argv);
541 static int builtin_source(char **argv);
542 static int builtin_test(char **argv);
543 static int builtin_trap(char **argv);
544 static int builtin_true(char **argv);
545 static int builtin_umask(char **argv);
546 static int builtin_unset(char **argv);
547 static int builtin_wait(char **argv);
548 #if ENABLE_HUSH_LOOPS
549 static int builtin_break(char **argv);
550 static int builtin_continue(char **argv);
552 #if ENABLE_HUSH_FUNCTIONS
553 static int builtin_return(char **argv);
556 /* Table of built-in functions. They can be forked or not, depending on
557 * context: within pipes, they fork. As simple commands, they do not.
558 * When used in non-forking context, they can change global variables
559 * in the parent shell process. If forked, of course they cannot.
560 * For example, 'unset foo | whatever' will parse and run, but foo will
561 * still be set at the end. */
562 struct built_in_command {
564 int (*function)(char **argv);
567 #define BLTIN(cmd, func, help) { cmd, func, help }
569 #define BLTIN(cmd, func, help) { cmd, func }
573 /* For now, echo and test are unconditionally enabled.
574 * Maybe make it configurable? */
575 static const struct built_in_command bltins[] = {
576 BLTIN("." , builtin_source , "Run commands in a file"),
577 BLTIN(":" , builtin_true , "No-op"),
578 BLTIN("[" , builtin_test , "Test condition"),
580 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
582 #if ENABLE_HUSH_LOOPS
583 BLTIN("break" , builtin_break , "Exit from a loop"),
585 BLTIN("cd" , builtin_cd , "Change directory"),
586 #if ENABLE_HUSH_LOOPS
587 BLTIN("continue", builtin_continue, "Start new loop iteration"),
589 BLTIN("echo" , builtin_echo , "Write to stdout"),
590 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
591 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
592 BLTIN("exit" , builtin_exit , "Exit"),
593 BLTIN("export" , builtin_export , "Set environment variable"),
595 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
598 BLTIN("help" , builtin_help , "List shell built-in commands"),
601 BLTIN("jobs" , builtin_jobs , "List active jobs"),
604 BLTIN("memleak" , builtin_memleak , "Debug tool"),
606 BLTIN("pwd" , builtin_pwd , "Print current directory"),
607 BLTIN("read" , builtin_read , "Input environment variable"),
608 #if ENABLE_HUSH_FUNCTIONS
609 BLTIN("return" , builtin_return , "Return from a function"),
611 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
612 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
613 BLTIN("test" , builtin_test , "Test condition"),
614 BLTIN("trap" , builtin_trap , "Trap signals"),
615 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
616 BLTIN("umask" , builtin_umask , "Set file creation mask"),
617 BLTIN("unset" , builtin_unset , "Unset environment variable"),
618 BLTIN("wait" , builtin_wait , "Wait for process"),
625 /* prevent disasters with G.debug_indent < 0 */
626 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
627 # define debug_enter() (G.debug_indent++)
628 # define debug_leave() (G.debug_indent--)
630 # define indent() ((void)0)
631 # define debug_enter() ((void)0)
632 # define debug_leave() ((void)0)
636 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
639 #ifndef debug_printf_parse
640 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
643 #ifndef debug_printf_exec
644 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
647 #ifndef debug_printf_env
648 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
651 #ifndef debug_printf_jobs
652 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
653 # define DEBUG_JOBS 1
655 # define DEBUG_JOBS 0
658 #ifndef debug_printf_expand
659 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
660 # define DEBUG_EXPAND 1
662 # define DEBUG_EXPAND 0
665 #ifndef debug_printf_glob
666 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
667 # define DEBUG_GLOB 1
669 # define DEBUG_GLOB 0
672 #ifndef debug_printf_list
673 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
676 #ifndef debug_printf_subst
677 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
680 #ifndef debug_printf_clean
681 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
682 # define DEBUG_CLEAN 1
684 # define DEBUG_CLEAN 0
688 static void debug_print_strings(const char *prefix, char **vv)
691 fprintf(stderr, "%s:\n", prefix);
693 fprintf(stderr, " '%s'\n", *vv++);
696 #define debug_print_strings(prefix, vv) ((void)0)
700 /* Leak hunting. Use hush_leaktool.sh for post-processing.
703 static void *xxmalloc(int lineno, size_t size)
705 void *ptr = xmalloc((size + 0xff) & ~0xff);
706 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
709 static void *xxrealloc(int lineno, void *ptr, size_t size)
711 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
712 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
715 static char *xxstrdup(int lineno, const char *str)
717 char *ptr = xstrdup(str);
718 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
721 static void xxfree(void *ptr)
723 fdprintf(2, "free %p\n", ptr);
726 #define xmalloc(s) xxmalloc(__LINE__, s)
727 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
728 #define xstrdup(s) xxstrdup(__LINE__, s)
729 #define free(p) xxfree(p)
733 /* Syntax and runtime errors. They always abort scripts.
734 * In interactive use they usually discard unparsed and/or unexecuted commands
735 * and return to the prompt.
736 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
739 # define die_if_script(lineno, fmt...) die_if_script(fmt)
740 # define syntax_error(lineno, msg) syntax_error(msg)
741 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
742 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
743 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
744 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
747 static void die_if_script(unsigned lineno, const char *fmt, ...)
752 bb_error_msg("hush.c:%u", lineno);
755 bb_verror_msg(fmt, p, NULL);
757 if (!G_interactive_fd)
761 static void syntax_error(unsigned lineno, const char *msg)
764 die_if_script(lineno, "syntax error: %s", msg);
766 die_if_script(lineno, "syntax error", NULL);
769 static void syntax_error_at(unsigned lineno, const char *msg)
771 die_if_script(lineno, "syntax error at '%s'", msg);
774 /* It so happens that all such cases are totally fatal
775 * even if shell is interactive: EOF while looking for closing
776 * delimiter. There is nowhere to read stuff from after that,
777 * it's EOF! The only choice is to terminate.
779 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
780 static void syntax_error_unterm_ch(unsigned lineno, char ch)
785 die_if_script(lineno, "syntax error: unterminated %s", msg);
789 static void syntax_error_unterm_str(unsigned lineno, const char *s)
791 die_if_script(lineno, "syntax error: unterminated %s", s);
794 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
799 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
803 # undef die_if_script
805 # undef syntax_error_at
806 # undef syntax_error_unterm_ch
807 # undef syntax_error_unterm_str
808 # undef syntax_error_unexpected_ch
810 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
811 # define syntax_error(msg) syntax_error(__LINE__, msg)
812 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
813 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
814 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
815 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
819 #if ENABLE_HUSH_INTERACTIVE
820 static void cmdedit_update_prompt(void);
822 # define cmdedit_update_prompt()
828 static int glob_needed(const char *s)
833 if (*s == '*' || *s == '[' || *s == '?')
840 static int is_well_formed_var_name(const char *s, char terminator)
842 if (!s || !(isalpha(*s) || *s == '_'))
845 while (isalnum(*s) || *s == '_')
847 return *s == terminator;
850 /* Replace each \x with x in place, return ptr past NUL. */
851 static char *unbackslash(char *src)
857 if ((*dst++ = *src++) == '\0')
863 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
884 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
885 v[count1 + count2] = NULL;
888 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
892 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
894 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
895 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
898 #define add_strings_to_strings(strings, add, need_to_dup) \
899 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
902 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
903 static char **add_string_to_strings(char **strings, char *add)
908 return add_strings_to_strings(strings, v, /*dup:*/ 0);
911 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
913 char **ptr = add_string_to_strings(strings, add);
914 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
917 #define add_string_to_strings(strings, add) \
918 xx_add_string_to_strings(__LINE__, strings, add)
921 static void free_strings(char **strings)
936 /* Helpers for setting new $n and restoring them back
938 typedef struct save_arg_t {
942 smallint sv_g_malloced;
945 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
949 sv->sv_argv0 = argv[0];
950 sv->sv_g_argv = G.global_argv;
951 sv->sv_g_argc = G.global_argc;
952 sv->sv_g_malloced = G.global_args_malloced;
954 argv[0] = G.global_argv[0]; /* retain $0 */
955 G.global_argv = argv;
956 G.global_args_malloced = 0;
964 static void restore_G_args(save_arg_t *sv, char **argv)
968 if (G.global_args_malloced) {
969 /* someone ran "set -- arg1 arg2 ...", undo */
971 while (*++pp) /* note: does not free $0 */
975 argv[0] = sv->sv_argv0;
976 G.global_argv = sv->sv_g_argv;
977 G.global_argc = sv->sv_g_argc;
978 G.global_args_malloced = sv->sv_g_malloced;
982 /* Basic theory of signal handling in shell
983 * ========================================
984 * This does not describe what hush does, rather, it is current understanding
985 * what it _should_ do. If it doesn't, it's a bug.
986 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
988 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
989 * is finished or backgrounded. It is the same in interactive and
990 * non-interactive shells, and is the same regardless of whether
991 * a user trap handler is installed or a shell special one is in effect.
992 * ^C or ^Z from keyboard seem to execute "at once" because it usually
993 * backgrounds (i.e. stops) or kills all members of currently running
996 * Wait builtin in interruptible by signals for which user trap is set
997 * or by SIGINT in interactive shell.
999 * Trap handlers will execute even within trap handlers. (right?)
1001 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1003 * If job control is off, backgrounded commands ("cmd &")
1004 * have SIGINT, SIGQUIT set to SIG_IGN.
1006 * Commands run in command substitution ("`cmd`")
1007 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1009 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
1010 * by the shell from its parent.
1012 * Siganls which differ from SIG_DFL action
1013 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1016 * SIGTERM (interactive): ignore
1017 * SIGHUP (interactive):
1018 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1019 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1020 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1021 * that all pipe members are stopped. Try this in bash:
1022 * while :; do :; done - ^Z does not background it
1023 * (while :; do :; done) - ^Z backgrounds it
1024 * SIGINT (interactive): wait for last pipe, ignore the rest
1025 * of the command line, show prompt. NB: ^C does not send SIGINT
1026 * to interactive shell while shell is waiting for a pipe,
1027 * since shell is bg'ed (is not in foreground process group).
1028 * Example 1: this waits 5 sec, but does not execute ls:
1029 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1030 * Example 2: this does not wait and does not execute ls:
1031 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1032 * Example 3: this does not wait 5 sec, but executes ls:
1033 * "sleep 5; ls -l" + press ^C
1035 * (What happens to signals which are IGN on shell start?)
1036 * (What happens with signal mask on shell start?)
1038 * Implementation in hush
1039 * ======================
1040 * We use in-kernel pending signal mask to determine which signals were sent.
1041 * We block all signals which we don't want to take action immediately,
1042 * i.e. we block all signals which need to have special handling as described
1043 * above, and all signals which have traps set.
1044 * After each pipe execution, we extract any pending signals via sigtimedwait()
1047 * unsigned non_DFL_mask: a mask of such "special" signals
1048 * sigset_t blocked_set: current blocked signal set
1051 * clear bit in blocked_set unless it is also in non_DFL_mask
1052 * "trap 'cmd' SIGxxx":
1053 * set bit in blocked_set (even if 'cmd' is '')
1054 * after [v]fork, if we plan to be a shell:
1055 * unblock signals with special interactive handling
1056 * (child shell is not interactive),
1057 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1058 * after [v]fork, if we plan to exec:
1059 * POSIX says pending signal mask is cleared in child - no need to clear it.
1060 * Restore blocked signal set to one inherited by shell just prior to exec.
1062 * Note: as a result, we do not use signal handlers much. The only uses
1063 * are to count SIGCHLDs
1064 * and to restore tty pgrp on signal-induced exit.
1067 SPECIAL_INTERACTIVE_SIGS = 0
1072 SPECIAL_JOB_SIGS = 0
1080 #if ENABLE_HUSH_FAST
1081 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1084 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1090 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1091 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1092 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1093 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1095 /* Restores tty foreground process group, and exits.
1096 * May be called as signal handler for fatal signal
1097 * (will resend signal to itself, producing correct exit state)
1098 * or called directly with -EXITCODE.
1099 * We also call it if xfunc is exiting. */
1100 static void sigexit(int sig) NORETURN;
1101 static void sigexit(int sig)
1103 /* Disable all signals: job control, SIGPIPE, etc. */
1104 sigprocmask_allsigs(SIG_BLOCK);
1106 /* Careful: we can end up here after [v]fork. Do not restore
1107 * tty pgrp then, only top-level shell process does that */
1108 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1109 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1111 /* Not a signal, just exit */
1115 kill_myself_with_sig(sig); /* does not return */
1119 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1120 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1124 /* Restores tty foreground process group, and exits. */
1125 static void hush_exit(int exitcode) NORETURN;
1126 static void hush_exit(int exitcode)
1128 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1129 /* Prevent recursion:
1130 * trap "echo Hi; exit" EXIT; exit
1132 char *argv[] = { NULL, G.traps[0], NULL };
1140 fflush(NULL); /* flush all streams */
1141 sigexit(- (exitcode & 0xff));
1147 static int check_and_run_traps(int sig)
1149 static const struct timespec zero_timespec = { 0, 0 };
1150 smalluint save_rcode;
1156 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1161 if (G.traps && G.traps[sig]) {
1162 if (G.traps[sig][0]) {
1163 /* We have user-defined handler */
1164 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1165 save_rcode = G.last_exitcode;
1168 G.last_exitcode = save_rcode;
1169 } /* else: "" trap, ignoring signal */
1172 /* not a trap: special action */
1174 #if ENABLE_HUSH_FAST
1177 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1181 /* Builtin was ^C'ed, make it look prettier: */
1188 /* bash is observed to signal whole process groups,
1189 * not individual processes */
1190 for (job = G.job_list; job; job = job->next) {
1193 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1194 if (kill(- job->pgrp, SIGHUP) == 0)
1195 kill(- job->pgrp, SIGCONT);
1200 default: /* ignored: */
1201 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1209 static const char *set_cwd(void)
1211 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1212 * we must not try to free(bb_msg_unknown) */
1213 if (G.cwd == bb_msg_unknown)
1215 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1217 G.cwd = bb_msg_unknown;
1223 * Shell and environment variable support
1225 static struct variable **get_ptr_to_local_var(const char *name)
1227 struct variable **pp;
1228 struct variable *cur;
1233 while ((cur = *pp) != NULL) {
1234 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1241 static struct variable *get_local_var(const char *name)
1243 struct variable **pp = get_ptr_to_local_var(name);
1249 static const char *get_local_var_value(const char *name)
1251 struct variable **pp = get_ptr_to_local_var(name);
1253 return strchr((*pp)->varstr, '=') + 1;
1257 /* str holds "NAME=VAL" and is expected to be malloced.
1258 * We take ownership of it.
1260 * 0: do not change export flag
1261 * (if creating new variable, flag will be 0)
1262 * 1: set export flag and putenv the variable
1263 * -1: clear export flag and unsetenv the variable
1264 * flg_read_only is set only when we handle -R var=val
1267 #define set_local_var(str, flg_export, flg_read_only) \
1268 set_local_var(str, flg_export)
1270 static int set_local_var(char *str, int flg_export, int flg_read_only)
1272 struct variable *cur;
1276 eq_sign = strchr(str, '=');
1277 if (!eq_sign) { /* not expected to ever happen? */
1282 name_len = eq_sign - str + 1; /* including '=' */
1283 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1285 if (strncmp(cur->varstr, str, name_len) != 0) {
1287 /* Bail out. Note that now cur points
1288 * to last var in linked list */
1294 /* We found an existing var with this name */
1295 if (cur->flg_read_only) {
1299 bb_error_msg("%s: readonly variable", str);
1303 if (flg_export == -1) {
1304 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1309 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1314 if (cur->max_len >= strlen(str)) {
1315 /* This one is from startup env, reuse space */
1316 strcpy(cur->varstr, str);
1319 /* max_len == 0 signifies "malloced" var, which we can
1320 * (and has to) free */
1324 goto set_str_and_exp;
1327 /* Not found - create next variable struct */
1328 cur->next = xzalloc(sizeof(*cur));
1334 cur->flg_read_only = flg_read_only;
1337 if (flg_export == 1)
1338 cur->flg_export = 1;
1339 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1340 cmdedit_update_prompt();
1341 if (cur->flg_export) {
1342 if (flg_export == -1) {
1343 cur->flg_export = 0;
1344 /* unsetenv was already done */
1346 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1347 return putenv(cur->varstr);
1353 static int unset_local_var_len(const char *name, int name_len)
1355 struct variable *cur;
1356 struct variable **var_pp;
1359 return EXIT_SUCCESS;
1360 var_pp = &G.top_var;
1361 while ((cur = *var_pp) != NULL) {
1362 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1363 if (cur->flg_read_only) {
1364 bb_error_msg("%s: readonly variable", name);
1365 return EXIT_FAILURE;
1367 *var_pp = cur->next;
1368 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1369 bb_unsetenv(cur->varstr);
1370 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1371 cmdedit_update_prompt();
1375 return EXIT_SUCCESS;
1377 var_pp = &cur->next;
1379 return EXIT_SUCCESS;
1382 static int unset_local_var(const char *name)
1384 return unset_local_var_len(name, strlen(name));
1387 static void unset_vars(char **strings)
1395 const char *eq = strchrnul(*v, '=');
1396 unset_local_var_len(*v, (int)(eq - *v));
1402 #if ENABLE_SH_MATH_SUPPORT
1403 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1404 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1405 static char *endofname(const char *name)
1413 if (!is_in_name(*p))
1419 static void arith_set_local_var(const char *name, const char *val, int flags)
1421 /* arith code doesnt malloc space, so do it for it */
1422 char *var = xasprintf("%s=%s", name, val);
1423 set_local_var(var, flags, 0);
1429 * Helpers for "var1=val1 var2=val2 cmd" feature
1431 static void add_vars(struct variable *var)
1433 struct variable *next;
1437 var->next = G.top_var;
1439 if (var->flg_export) {
1440 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1441 putenv(var->varstr);
1443 debug_printf_env("%s: restoring local '%s'\n", __func__, var->varstr);
1449 static struct variable *set_vars_and_save_old(char **strings)
1452 struct variable *old = NULL;
1458 struct variable *var_p;
1459 struct variable **var_pp;
1462 eq = strchr(*s, '=');
1465 var_pp = get_ptr_to_local_var(*s);
1468 /* Remove variable from global linked list */
1470 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1471 *var_pp = var_p->next;
1472 /* Add it to returned list */
1476 set_local_var(*s, 1, 0);
1487 static int static_get(struct in_str *i)
1496 static int static_peek(struct in_str *i)
1501 #if ENABLE_HUSH_INTERACTIVE
1503 static void cmdedit_update_prompt(void)
1505 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1506 G.PS1 = get_local_var_value("PS1");
1509 G.PS2 = get_local_var_value("PS2");
1517 static const char* setup_prompt_string(int promptmode)
1519 const char *prompt_str;
1520 debug_printf("setup_prompt_string %d ", promptmode);
1521 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1522 /* Set up the prompt */
1523 if (promptmode == 0) { /* PS1 */
1525 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1530 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1531 debug_printf("result '%s'\n", prompt_str);
1535 static void get_user_input(struct in_str *i)
1538 const char *prompt_str;
1540 prompt_str = setup_prompt_string(i->promptmode);
1541 #if ENABLE_FEATURE_EDITING
1542 /* Enable command line editing only while a command line
1543 * is actually being read */
1546 /* buglet: SIGINT will not make new prompt to appear _at once_,
1547 * only after <Enter>. (^C will work) */
1548 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1549 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1550 check_and_run_traps(0);
1551 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1552 i->eof_flag = (r < 0);
1553 if (i->eof_flag) { /* EOF/error detected */
1554 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1555 G.user_input_buf[1] = '\0';
1560 fputs(prompt_str, stdout);
1562 G.user_input_buf[0] = r = fgetc(i->file);
1563 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1564 //do we need check_and_run_traps(0)? (maybe only if stdin)
1565 } while (G.flag_SIGINT);
1566 i->eof_flag = (r == EOF);
1568 i->p = G.user_input_buf;
1571 #endif /* INTERACTIVE */
1573 /* This is the magic location that prints prompts
1574 * and gets data back from the user */
1575 static int file_get(struct in_str *i)
1579 /* If there is data waiting, eat it up */
1580 if (i->p && *i->p) {
1581 #if ENABLE_HUSH_INTERACTIVE
1585 if (i->eof_flag && !*i->p)
1587 /* note: ch is never NUL */
1589 /* need to double check i->file because we might be doing something
1590 * more complicated by now, like sourcing or substituting. */
1591 #if ENABLE_HUSH_INTERACTIVE
1592 if (G_interactive_fd && i->promptme && i->file == stdin) {
1595 } while (!*i->p); /* need non-empty line */
1596 i->promptmode = 1; /* PS2 */
1601 do ch = fgetc(i->file); while (ch == '\0');
1603 debug_printf("file_get: got '%c' %d\n", ch, ch);
1604 #if ENABLE_HUSH_INTERACTIVE
1611 /* All callers guarantee this routine will never
1612 * be used right after a newline, so prompting is not needed.
1614 static int file_peek(struct in_str *i)
1617 if (i->p && *i->p) {
1618 if (i->eof_flag && !i->p[1])
1621 /* note: ch is never NUL */
1623 do ch = fgetc(i->file); while (ch == '\0');
1624 i->eof_flag = (ch == EOF);
1625 i->peek_buf[0] = ch;
1626 i->peek_buf[1] = '\0';
1628 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1632 static void setup_file_in_str(struct in_str *i, FILE *f)
1634 i->peek = file_peek;
1636 #if ENABLE_HUSH_INTERACTIVE
1638 i->promptmode = 0; /* PS1 */
1644 static void setup_string_in_str(struct in_str *i, const char *s)
1646 i->peek = static_peek;
1647 i->get = static_get;
1648 #if ENABLE_HUSH_INTERACTIVE
1650 i->promptmode = 0; /* PS1 */
1660 #define B_CHUNK (32 * sizeof(char*))
1662 static void o_reset_to_empty_unquoted(o_string *o)
1670 static void o_free(o_string *o)
1673 memset(o, 0, sizeof(*o));
1676 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1681 static void o_grow_by(o_string *o, int len)
1683 if (o->length + len > o->maxlen) {
1684 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1685 o->data = xrealloc(o->data, 1 + o->maxlen);
1689 static void o_addchr(o_string *o, int ch)
1691 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1693 o->data[o->length] = ch;
1695 o->data[o->length] = '\0';
1698 static void o_addblock(o_string *o, const char *str, int len)
1701 memcpy(&o->data[o->length], str, len);
1703 o->data[o->length] = '\0';
1707 static void o_addstr(o_string *o, const char *str)
1709 o_addblock(o, str, strlen(str));
1711 static void nommu_addchr(o_string *o, int ch)
1717 #define nommu_addchr(o, str) ((void)0)
1720 static void o_addstr_with_NUL(o_string *o, const char *str)
1722 o_addblock(o, str, strlen(str) + 1);
1725 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1730 && (*str != '*' && *str != '?' && *str != '[')
1738 /* My analysis of quoting semantics tells me that state information
1739 * is associated with a destination, not a source.
1741 static void o_addqchr(o_string *o, int ch)
1744 char *found = strchr("*?[\\", ch);
1749 o->data[o->length] = '\\';
1752 o->data[o->length] = ch;
1754 o->data[o->length] = '\0';
1757 static void o_addQchr(o_string *o, int ch)
1760 if (o->o_escape && strchr("*?[\\", ch)) {
1762 o->data[o->length] = '\\';
1766 o->data[o->length] = ch;
1768 o->data[o->length] = '\0';
1771 static void o_addQstr(o_string *o, const char *str, int len)
1774 o_addblock(o, str, len);
1780 int ordinary_cnt = strcspn(str, "*?[\\");
1781 if (ordinary_cnt > len) /* paranoia */
1783 o_addblock(o, str, ordinary_cnt);
1784 if (ordinary_cnt == len)
1786 str += ordinary_cnt;
1787 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1791 if (ch) { /* it is necessarily one of "*?[\\" */
1793 o->data[o->length] = '\\';
1797 o->data[o->length] = ch;
1799 o->data[o->length] = '\0';
1803 /* A special kind of o_string for $VAR and `cmd` expansion.
1804 * It contains char* list[] at the beginning, which is grown in 16 element
1805 * increments. Actual string data starts at the next multiple of 16 * (char*).
1806 * list[i] contains an INDEX (int!) into this string data.
1807 * It means that if list[] needs to grow, data needs to be moved higher up
1808 * but list[i]'s need not be modified.
1809 * NB: remembering how many list[i]'s you have there is crucial.
1810 * o_finalize_list() operation post-processes this structure - calculates
1811 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1813 #if DEBUG_EXPAND || DEBUG_GLOB
1814 static void debug_print_list(const char *prefix, o_string *o, int n)
1816 char **list = (char**)o->data;
1817 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1821 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1822 prefix, list, n, string_start, o->length, o->maxlen);
1825 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1826 o->data + (int)list[i] + string_start,
1827 o->data + (int)list[i] + string_start);
1831 const char *p = o->data + (int)list[n - 1] + string_start;
1833 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1837 #define debug_print_list(prefix, o, n) ((void)0)
1840 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1841 * in list[n] so that it points past last stored byte so far.
1842 * It returns n+1. */
1843 static int o_save_ptr_helper(o_string *o, int n)
1845 char **list = (char**)o->data;
1849 if (!o->has_empty_slot) {
1850 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1851 string_len = o->length - string_start;
1852 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1853 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1854 /* list[n] points to string_start, make space for 16 more pointers */
1855 o->maxlen += 0x10 * sizeof(list[0]);
1856 o->data = xrealloc(o->data, o->maxlen + 1);
1857 list = (char**)o->data;
1858 memmove(list + n + 0x10, list + n, string_len);
1859 o->length += 0x10 * sizeof(list[0]);
1861 debug_printf_list("list[%d]=%d string_start=%d\n",
1862 n, string_len, string_start);
1865 /* We have empty slot at list[n], reuse without growth */
1866 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1867 string_len = o->length - string_start;
1868 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1869 n, string_len, string_start);
1870 o->has_empty_slot = 0;
1872 list[n] = (char*)(ptrdiff_t)string_len;
1876 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1877 static int o_get_last_ptr(o_string *o, int n)
1879 char **list = (char**)o->data;
1880 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1882 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1885 /* o_glob performs globbing on last list[], saving each result
1886 * as a new list[]. */
1887 static int o_glob(o_string *o, int n)
1893 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1895 return o_save_ptr_helper(o, n);
1896 pattern = o->data + o_get_last_ptr(o, n);
1897 debug_printf_glob("glob pattern '%s'\n", pattern);
1898 if (!glob_needed(pattern)) {
1900 o->length = unbackslash(pattern) - o->data;
1901 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1902 return o_save_ptr_helper(o, n);
1905 memset(&globdata, 0, sizeof(globdata));
1906 gr = glob(pattern, 0, NULL, &globdata);
1907 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1908 if (gr == GLOB_NOSPACE)
1909 bb_error_msg_and_die("out of memory during glob");
1910 if (gr == GLOB_NOMATCH) {
1911 globfree(&globdata);
1914 if (gr != 0) { /* GLOB_ABORTED ? */
1915 /* TODO: testcase for bad glob pattern behavior */
1916 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1918 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1919 char **argv = globdata.gl_pathv;
1920 o->length = pattern - o->data; /* "forget" pattern */
1922 o_addstr_with_NUL(o, *argv);
1923 n = o_save_ptr_helper(o, n);
1929 globfree(&globdata);
1931 debug_print_list("o_glob returning", o, n);
1935 /* If o->o_glob == 1, glob the string so far remembered.
1936 * Otherwise, just finish current list[] and start new */
1937 static int o_save_ptr(o_string *o, int n)
1939 if (o->o_glob) { /* if globbing is requested */
1940 /* If o->has_empty_slot, list[n] was already globbed
1941 * (if it was requested back then when it was filled)
1942 * so don't do that again! */
1943 if (!o->has_empty_slot)
1944 return o_glob(o, n); /* o_save_ptr_helper is inside */
1946 return o_save_ptr_helper(o, n);
1949 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1950 static char **o_finalize_list(o_string *o, int n)
1955 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1957 debug_print_list("finalized", o, n);
1958 debug_printf_expand("finalized n:%d\n", n);
1959 list = (char**)o->data;
1960 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1964 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1970 /* Expansion can recurse */
1971 #if ENABLE_HUSH_TICK
1972 static int process_command_subs(o_string *dest, const char *s);
1974 static char *expand_string_to_string(const char *str);
1976 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1977 parse_stream_dquoted(dest, input, dquote_end)
1979 static int parse_stream_dquoted(o_string *as_string,
1981 struct in_str *input,
1984 /* expand_strvec_to_strvec() takes a list of strings, expands
1985 * all variable references within and returns a pointer to
1986 * a list of expanded strings, possibly with larger number
1987 * of strings. (Think VAR="a b"; echo $VAR).
1988 * This new list is allocated as a single malloc block.
1989 * NULL-terminated list of char* pointers is at the beginning of it,
1990 * followed by strings themself.
1991 * Caller can deallocate entire list by single free(list). */
1993 /* Store given string, finalizing the word and starting new one whenever
1994 * we encounter IFS char(s). This is used for expanding variable values.
1995 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1996 static int expand_on_ifs(o_string *output, int n, const char *str)
1999 int word_len = strcspn(str, G.ifs);
2001 if (output->o_escape || !output->o_glob)
2002 o_addQstr(output, str, word_len);
2003 else /* protect backslashes against globbing up :) */
2004 o_addblock_duplicate_backslash(output, str, word_len);
2007 if (!*str) /* EOL - do not finalize word */
2009 o_addchr(output, '\0');
2010 debug_print_list("expand_on_ifs", output, n);
2011 n = o_save_ptr(output, n);
2012 str += strspn(str, G.ifs); /* skip ifs chars */
2014 debug_print_list("expand_on_ifs[1]", output, n);
2018 /* Helper to expand $((...)) and heredoc body. These act as if
2019 * they are in double quotes, with the exception that they are not :).
2020 * Just the rules are similar: "expand only $var and `cmd`"
2022 * Returns malloced string.
2023 * As an optimization, we return NULL if expansion is not needed.
2025 static char *expand_pseudo_dquoted(const char *str)
2028 struct in_str input;
2029 o_string dest = NULL_O_STRING;
2031 if (strchr(str, '$') == NULL
2032 #if ENABLE_HUSH_TICK
2033 && strchr(str, '`') == NULL
2039 /* We need to expand. Example:
2040 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2042 setup_string_in_str(&input, str);
2043 parse_stream_dquoted(NULL, &dest, &input, EOF);
2044 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2045 exp_str = expand_string_to_string(dest.data);
2046 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2047 o_free_unsafe(&dest);
2051 /* Expand all variable references in given string, adding words to list[]
2052 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2053 * to be filled). This routine is extremely tricky: has to deal with
2054 * variables/parameters with whitespace, $* and $@, and constructs like
2055 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2056 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2058 /* or_mask is either 0 (normal case) or 0x80
2059 * (expansion of right-hand side of assignment == 1-element expand.
2060 * It will also do no globbing, and thus we must not backslash-quote!) */
2067 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
2068 debug_print_list("expand_vars_to_list", output, n);
2069 n = o_save_ptr(output, n);
2070 debug_print_list("expand_vars_to_list[0]", output, n);
2072 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2075 char *dyn_val = NULL;
2076 const char *val = NULL;
2077 #if ENABLE_HUSH_TICK
2078 o_string subst_result = NULL_O_STRING;
2080 #if ENABLE_SH_MATH_SUPPORT
2081 char arith_buf[sizeof(arith_t)*3 + 2];
2083 o_addblock(output, arg, p - arg);
2084 debug_print_list("expand_vars_to_list[1]", output, n);
2086 p = strchr(p, SPECIAL_VAR_SYMBOL);
2088 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2089 /* "$@" is special. Even if quoted, it can still
2090 * expand to nothing (not even an empty string) */
2091 if ((first_ch & 0x7f) != '@')
2092 ored_ch |= first_ch;
2094 switch (first_ch & 0x7f) {
2095 /* Highest bit in first_ch indicates that var is double-quoted */
2097 val = utoa(G.root_pid);
2099 case '!': /* bg pid */
2100 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2102 case '?': /* exitcode */
2103 val = utoa(G.last_exitcode);
2105 case '#': /* argc */
2106 if (arg[1] != SPECIAL_VAR_SYMBOL)
2107 /* actually, it's a ${#var} */
2109 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2114 if (!G.global_argv[i])
2116 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2117 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2118 smallint sv = output->o_escape;
2119 /* unquoted var's contents should be globbed, so don't escape */
2120 output->o_escape = 0;
2121 while (G.global_argv[i]) {
2122 n = expand_on_ifs(output, n, G.global_argv[i]);
2123 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2124 if (G.global_argv[i++][0] && G.global_argv[i]) {
2125 /* this argv[] is not empty and not last:
2126 * put terminating NUL, start new word */
2127 o_addchr(output, '\0');
2128 debug_print_list("expand_vars_to_list[2]", output, n);
2129 n = o_save_ptr(output, n);
2130 debug_print_list("expand_vars_to_list[3]", output, n);
2133 output->o_escape = sv;
2135 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2136 * and in this case should treat it like '$*' - see 'else...' below */
2137 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2139 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2140 if (++i >= G.global_argc)
2142 o_addchr(output, '\0');
2143 debug_print_list("expand_vars_to_list[4]", output, n);
2144 n = o_save_ptr(output, n);
2146 } else { /* quoted $*: add as one word */
2148 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2149 if (!G.global_argv[++i])
2152 o_addchr(output, G.ifs[0]);
2156 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2157 /* "Empty variable", used to make "" etc to not disappear */
2161 #if ENABLE_HUSH_TICK
2162 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2165 /* Can't just stuff it into output o_string,
2166 * expanded result may need to be globbed
2167 * and $IFS-splitted */
2168 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2169 process_command_subs(&subst_result, arg);
2170 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2171 val = subst_result.data;
2174 #if ENABLE_SH_MATH_SUPPORT
2175 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2176 arith_eval_hooks_t hooks;
2181 arg++; /* skip '+' */
2182 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2183 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2185 exp_str = expand_pseudo_dquoted(arg);
2186 hooks.lookupvar = get_local_var_value;
2187 hooks.setvar = arith_set_local_var;
2188 hooks.endofname = endofname;
2189 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2193 const char *msg = "error in arithmetic";
2196 msg = "exponent less than 0";
2199 msg = "divide by 0";
2202 msg = "expression recursion loop detected";
2207 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2208 sprintf(arith_buf, arith_t_fmt, res);
2213 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2215 bool exp_len = false;
2216 bool exp_null = false;
2218 char exp_save = exp_save; /* for compiler */
2219 char exp_op = exp_op; /* for compiler */
2220 char *exp_word = exp_word; /* for compiler */
2224 arg[0] = first_ch & 0x7f;
2226 /* prepare for expansions */
2227 if (var[0] == '#') {
2228 /* handle length expansion ${#var} */
2232 /* maybe handle parameter expansion */
2233 exp_off = strcspn(var, ":-=+?%#");
2237 exp_save = var[exp_off];
2238 exp_null = exp_save == ':';
2239 exp_word = var + exp_off;
2242 exp_op = *exp_word++;
2243 var[exp_off] = '\0';
2247 /* lookup the variable in question */
2248 if (isdigit(var[0])) {
2249 /* handle_dollar() should have vetted var for us */
2251 if (i < G.global_argc)
2252 val = G.global_argv[i];
2253 /* else val remains NULL: $N with too big N */
2255 val = get_local_var_value(var);
2257 /* handle any expansions */
2259 debug_printf_expand("expand: length of '%s' = ", val);
2260 val = utoa(val ? strlen(val) : 0);
2261 debug_printf_expand("%s\n", val);
2262 } else if (exp_off) {
2263 if (exp_op == '%' || exp_op == '#') {
2265 /* we need to do a pattern match */
2268 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2269 if (exp_op == *exp_word) /* ## or %% */
2271 val = dyn_val = xstrdup(val);
2272 loc = scan(dyn_val, exp_word, match_at_left);
2273 if (match_at_left) /* # or ## */
2275 else if (loc) /* % or %% and match was found */
2279 /* we need to do an expansion */
2280 int exp_test = (!val || (exp_null && !val[0]));
2282 exp_test = !exp_test;
2283 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2284 exp_null ? "true" : "false", exp_test);
2286 if (exp_op == '?') {
2287 //TODO: how interactive bash aborts expansion mid-command?
2288 /* ${var?[error_msg_if_unset]} */
2289 /* ${var:?[error_msg_if_unset_or_null]} */
2290 /* mimic bash message */
2291 die_if_script("%s: %s",
2293 exp_word[0] ? exp_word : "parameter null or not set"
2299 if (exp_op == '=') {
2300 /* ${var=[word]} or ${var:=[word]} */
2301 if (isdigit(var[0]) || var[0] == '#') {
2302 /* mimic bash message */
2303 die_if_script("$%s: cannot assign in this way", var);
2306 char *new_var = xasprintf("%s=%s", var, val);
2307 set_local_var(new_var, 0, 0);
2313 var[exp_off] = exp_save;
2317 #if ENABLE_HUSH_TICK
2320 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2321 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2323 /* unquoted var's contents should be globbed, so don't escape */
2324 smallint sv = output->o_escape;
2325 output->o_escape = 0;
2326 n = expand_on_ifs(output, n, val);
2328 output->o_escape = sv;
2330 } else { /* quoted $VAR, val will be appended below */
2331 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2334 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2337 o_addQstr(output, val, strlen(val));
2340 /* Do the check to avoid writing to a const string */
2341 if (*p != SPECIAL_VAR_SYMBOL)
2342 *p = SPECIAL_VAR_SYMBOL;
2344 #if ENABLE_HUSH_TICK
2345 o_free(&subst_result);
2348 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2351 debug_print_list("expand_vars_to_list[a]", output, n);
2352 /* this part is literal, and it was already pre-quoted
2353 * if needed (much earlier), do not use o_addQstr here! */
2354 o_addstr_with_NUL(output, arg);
2355 debug_print_list("expand_vars_to_list[b]", output, n);
2356 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2357 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2360 /* allow to reuse list[n] later without re-growth */
2361 output->has_empty_slot = 1;
2363 o_addchr(output, '\0');
2368 static char **expand_variables(char **argv, int or_mask)
2373 o_string output = NULL_O_STRING;
2375 if (or_mask & 0x100) {
2376 output.o_escape = 1; /* protect against globbing for "$var" */
2377 /* (unquoted $var will temporarily switch it off) */
2384 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2387 debug_print_list("expand_variables", &output, n);
2389 /* output.data (malloced in one block) gets returned in "list" */
2390 list = o_finalize_list(&output, n);
2391 debug_print_strings("expand_variables[1]", list);
2395 static char **expand_strvec_to_strvec(char **argv)
2397 return expand_variables(argv, 0x100);
2400 /* Used for expansion of right hand of assignments */
2401 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2403 static char *expand_string_to_string(const char *str)
2405 char *argv[2], **list;
2407 argv[0] = (char*)str;
2409 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2411 if (!list[0] || list[1])
2412 bb_error_msg_and_die("BUG in varexp2");
2413 /* actually, just move string 2*sizeof(char*) bytes back */
2414 overlapping_strcpy((char*)list, list[0]);
2415 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2419 /* Used for "eval" builtin */
2420 static char* expand_strvec_to_string(char **argv)
2424 list = expand_variables(argv, 0x80);
2425 /* Convert all NULs to spaces */
2430 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2431 bb_error_msg_and_die("BUG in varexp3");
2432 /* bash uses ' ' regardless of $IFS contents */
2437 overlapping_strcpy((char*)list, list[0]);
2438 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2442 static char **expand_assignments(char **argv, int count)
2446 /* Expand assignments into one string each */
2447 for (i = 0; i < count; i++) {
2448 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2456 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2458 static void reset_traps_to_defaults(void)
2460 /* This function is always called in a child shell
2461 * after fork (not vfork, NOMMU doesn't use this function).
2462 * Child shells are not interactive.
2463 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2464 * Testcase: (while :; do :; done) + ^Z should background.
2465 * Same goes for SIGTERM, SIGHUP, SIGINT.
2470 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2473 /* Stupid. It can be done with *single* &= op, but we can't use
2474 * the fact that G.blocked_set is implemented as a bitmask... */
2475 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2479 sigdelset(&G.blocked_set, sig);
2486 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2487 mask = G.non_DFL_mask;
2488 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2492 G.traps[sig] = NULL;
2493 /* There is no signal for 0 (EXIT) */
2496 /* There was a trap handler, we are removing it.
2497 * But if sig still has non-DFL handling,
2498 * we should not unblock it. */
2501 sigdelset(&G.blocked_set, sig);
2503 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2508 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2509 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2511 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2512 char *heredoc_argv[4];
2513 struct variable *cur;
2514 #if ENABLE_HUSH_FUNCTIONS
2515 struct function *funcp;
2520 if (!g_argv0) { /* heredoc */
2521 argv = heredoc_argv;
2522 argv[0] = (char *) G.argv0_for_re_execing;
2523 argv[1] = (char *) "-<";
2524 argv[2] = (char *) s;
2526 pp = &argv[3]; /* used as pointer to empty environment */
2530 sprintf(param_buf, "-$%x:%x:%x" IF_HUSH_LOOPS(":%x")
2531 , (unsigned) G.root_pid
2532 , (unsigned) G.last_bg_pid
2533 , (unsigned) G.last_exitcode
2534 IF_HUSH_LOOPS(, G.depth_of_loop)
2536 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2537 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2540 for (cur = G.top_var; cur; cur = cur->next) {
2541 if (!cur->flg_export || cur->flg_read_only)
2544 #if ENABLE_HUSH_FUNCTIONS
2545 for (funcp = G.top_func; funcp; funcp = funcp->next)
2551 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2552 *pp++ = (char *) G.argv0_for_re_execing;
2554 for (cur = G.top_var; cur; cur = cur->next) {
2555 if (cur->varstr == hush_version_str)
2557 if (cur->flg_read_only) {
2558 *pp++ = (char *) "-R";
2559 *pp++ = cur->varstr;
2560 } else if (!cur->flg_export) {
2561 *pp++ = (char *) "-V";
2562 *pp++ = cur->varstr;
2565 #if ENABLE_HUSH_FUNCTIONS
2566 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2567 *pp++ = (char *) "-F";
2568 *pp++ = funcp->name;
2569 *pp++ = funcp->body_as_string;
2572 /* We can pass activated traps here. Say, -Tnn:trap_string
2574 * However, POSIX says that subshells reset signals with traps
2576 * I tested bash-3.2 and it not only does that with true subshells
2577 * of the form ( list ), but with any forked children shells.
2578 * I set trap "echo W" WINCH; and then tried:
2580 * { echo 1; sleep 20; echo 2; } &
2581 * while true; do echo 1; sleep 20; echo 2; break; done &
2582 * true | { echo 1; sleep 20; echo 2; } | cat
2584 * In all these cases sending SIGWINCH to the child shell
2585 * did not run the trap. If I add trap "echo V" WINCH;
2586 * _inside_ group (just before echo 1), it works.
2588 * I conclude it means we don't need to pass active traps here.
2589 * exec syscall below resets them to SIG_DFL for us.
2591 *pp++ = (char *) "-c";
2596 /* *pp = NULL; - is already there */
2600 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2601 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2602 execve(bb_busybox_exec_path, argv, pp);
2603 /* Fallback. Useful for init=/bin/hush usage etc */
2604 if (argv[0][0] == '/')
2605 execve(argv[0], argv, pp);
2606 xfunc_error_retval = 127;
2607 bb_error_msg_and_die("can't re-execute the shell");
2609 #endif /* !BB_MMU */
2612 static void setup_heredoc(struct redir_struct *redir)
2614 struct fd_pair pair;
2617 /* the _body_ of heredoc (misleading field name) */
2618 const char *heredoc = redir->rd_filename;
2625 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2626 expanded = expand_pseudo_dquoted(heredoc);
2630 len = strlen(heredoc);
2632 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2634 xmove_fd(pair.rd, redir->rd_fd);
2636 /* Try writing without forking. Newer kernels have
2637 * dynamically growing pipes. Must use non-blocking write! */
2640 written = write(pair.wr, heredoc, len);
2651 ndelay_off(pair.wr);
2653 /* Okay, pipe buffer was not big enough */
2654 /* Note: we must not create a stray child (bastard? :)
2655 * for the unsuspecting parent process. Child creates a grandchild
2656 * and exits before parent execs the process which consumes heredoc
2657 * (that exec happens after we return from this function) */
2663 bb_perror_msg_and_die("vfork");
2666 disable_restore_tty_pgrp_on_exit();
2667 pid = BB_MMU ? fork() : vfork();
2669 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2673 close(redir->rd_fd); /* read side of the pipe */
2675 full_write(pair.wr, heredoc, len); /* may loop or block */
2678 /* Delegate blocking writes to another process */
2679 xmove_fd(pair.wr, STDOUT_FILENO);
2680 re_execute_shell(&to_free, heredoc, NULL, NULL);
2684 #if ENABLE_HUSH_FAST
2686 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2688 enable_restore_tty_pgrp_on_exit();
2694 wait(NULL); /* wait till child has died */
2697 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2698 * and stderr if they are redirected. */
2699 static int setup_redirects(struct command *prog, int squirrel[])
2702 struct redir_struct *redir;
2704 for (redir = prog->redirects; redir; redir = redir->next) {
2705 if (redir->rd_type == REDIRECT_HEREDOC2) {
2706 /* rd_fd<<HERE case */
2707 if (squirrel && redir->rd_fd < 3
2708 && squirrel[redir->rd_fd] < 0
2710 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2712 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2714 debug_printf_parse("set heredoc '%s'\n",
2715 redir->rd_filename);
2716 setup_heredoc(redir);
2720 if (redir->rd_dup == REDIRFD_TO_FILE) {
2721 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2723 if (redir->rd_filename == NULL) {
2724 /* Something went wrong in the parse.
2725 * Pretend it didn't happen */
2726 bb_error_msg("bug in redirect parse");
2729 mode = redir_table[redir->rd_type].mode;
2730 p = expand_string_to_string(redir->rd_filename);
2731 openfd = open_or_warn(p, mode);
2734 /* this could get lost if stderr has been redirected, but
2735 * bash and ash both lose it as well (though zsh doesn't!) */
2736 //what the above comment tries to say?
2740 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2741 openfd = redir->rd_dup;
2744 if (openfd != redir->rd_fd) {
2745 if (squirrel && redir->rd_fd < 3
2746 && squirrel[redir->rd_fd] < 0
2748 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2750 if (openfd == REDIRFD_CLOSE) {
2751 /* "n>-" means "close me" */
2752 close(redir->rd_fd);
2754 xdup2(openfd, redir->rd_fd);
2755 if (redir->rd_dup == REDIRFD_TO_FILE)
2763 static void restore_redirects(int squirrel[])
2766 for (i = 0; i < 3; i++) {
2769 /* We simply die on error */
2776 static void free_pipe_list(struct pipe *head);
2778 /* Return code is the exit status of the pipe */
2779 static void free_pipe(struct pipe *pi)
2782 struct command *command;
2783 struct redir_struct *r, *rnext;
2786 if (pi->stopped_cmds > 0) /* why? */
2788 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2789 for (i = 0; i < pi->num_cmds; i++) {
2790 command = &pi->cmds[i];
2791 debug_printf_clean(" command %d:\n", i);
2792 if (command->argv) {
2793 for (a = 0, p = command->argv; *p; a++, p++) {
2794 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2796 free_strings(command->argv);
2797 command->argv = NULL;
2799 /* not "else if": on syntax error, we may have both! */
2800 if (command->group) {
2801 debug_printf_clean(" begin group (grp_type:%d)\n",
2803 free_pipe_list(command->group);
2804 debug_printf_clean(" end group\n");
2805 command->group = NULL;
2807 /* else is crucial here.
2808 * If group != NULL, child_func is meaningless */
2809 #if ENABLE_HUSH_FUNCTIONS
2810 else if (command->child_func) {
2811 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2812 command->child_func->parent_cmd = NULL;
2816 free(command->group_as_string);
2817 command->group_as_string = NULL;
2819 for (r = command->redirects; r; r = rnext) {
2820 debug_printf_clean(" redirect %d%s",
2821 r->rd_fd, redir_table[r->rd_type].descrip);
2822 /* guard against the case >$FOO, where foo is unset or blank */
2823 if (r->rd_filename) {
2824 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2825 free(r->rd_filename);
2826 r->rd_filename = NULL;
2828 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2832 command->redirects = NULL;
2834 free(pi->cmds); /* children are an array, they get freed all at once */
2842 static void free_pipe_list(struct pipe *head)
2844 struct pipe *pi, *next;
2846 for (pi = head; pi; pi = next) {
2848 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2851 debug_printf_clean("pipe followup code %d\n", pi->followup);
2853 /*pi->next = NULL;*/
2859 static int run_list(struct pipe *pi);
2861 #define parse_stream(pstring, input, end_trigger) \
2862 parse_stream(input, end_trigger)
2864 static struct pipe *parse_stream(char **pstring,
2865 struct in_str *input,
2867 static void parse_and_run_string(const char *s);
2870 static const struct built_in_command* find_builtin(const char *name)
2872 const struct built_in_command *x;
2873 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2874 if (strcmp(name, x->cmd) != 0)
2876 debug_printf_exec("found builtin '%s'\n", name);
2882 #if ENABLE_HUSH_FUNCTIONS
2883 static const struct function *find_function(const char *name)
2885 const struct function *funcp = G.top_func;
2887 if (strcmp(name, funcp->name) == 0) {
2890 funcp = funcp->next;
2893 debug_printf_exec("found function '%s'\n", name);
2897 /* Note: takes ownership on name ptr */
2898 static struct function *new_function(char *name)
2900 struct function *funcp;
2901 struct function **funcpp = &G.top_func;
2903 while ((funcp = *funcpp) != NULL) {
2904 struct command *cmd;
2906 if (strcmp(funcp->name, name) != 0) {
2907 funcpp = &funcp->next;
2911 cmd = funcp->parent_cmd;
2912 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2914 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2916 /* Note: if !funcp->body, do not free body_as_string!
2917 * This is a special case of "-F name body" function:
2918 * body_as_string was not malloced! */
2920 free_pipe_list(funcp->body);
2922 free(funcp->body_as_string);
2926 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2927 cmd->argv[0] = funcp->name;
2928 cmd->group = funcp->body;
2930 cmd->group_as_string = funcp->body_as_string;
2935 debug_printf_exec("remembering new function '%s'\n", name);
2936 funcp = *funcpp = xzalloc(sizeof(*funcp));
2937 /*funcp->next = NULL;*/
2943 static void unset_func(const char *name)
2945 struct function *funcp;
2946 struct function **funcpp = &G.top_func;
2948 while ((funcp = *funcpp) != NULL) {
2949 if (strcmp(funcp->name, name) == 0) {
2950 *funcpp = funcp->next;
2951 /* funcp is unlinked now, deleting it.
2952 * Note: if !funcp->body, the function was created by
2953 * "-F name body", do not free ->body_as_string
2954 * and ->name as they were not malloced. */
2956 free_pipe_list(funcp->body);
2959 free(funcp->body_as_string);
2965 funcpp = &funcp->next;
2970 #define exec_function(nommu_save, funcp, argv) \
2971 exec_function(funcp, argv)
2973 static void exec_function(nommu_save_t *nommu_save,
2974 const struct function *funcp,
2975 char **argv) NORETURN;
2976 static void exec_function(nommu_save_t *nommu_save,
2977 const struct function *funcp,
2983 argv[0] = G.global_argv[0];
2984 G.global_argv = argv;
2988 /* On MMU, funcp->body is always non-NULL */
2989 n = run_list(funcp->body);
2993 re_execute_shell(&nommu_save->argv_from_re_execing,
2994 funcp->body_as_string,
3000 static int run_function(const struct function *funcp, char **argv)
3006 save_and_replace_G_args(&sv, argv);
3007 /* "we are in function, ok to use return" */
3008 sv_flg = G.flag_return_in_progress;
3009 G.flag_return_in_progress = -1;
3011 /* On MMU, funcp->body is always non-NULL */
3014 /* Function defined by -F */
3015 parse_and_run_string(funcp->body_as_string);
3016 rc = G.last_exitcode;
3020 rc = run_list(funcp->body);
3023 G.flag_return_in_progress = sv_flg;
3024 restore_G_args(&sv, argv);
3028 #endif /* ENABLE_HUSH_FUNCTIONS */
3032 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3033 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3034 #define pseudo_exec(nommu_save, command, argv_expanded) \
3035 pseudo_exec(command, argv_expanded)
3038 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3040 * Don't exit() here. If you don't exec, use _exit instead.
3041 * The at_exit handlers apparently confuse the calling process,
3042 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3043 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3044 char **argv, int assignment_cnt,
3045 char **argv_expanded) NORETURN;
3046 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3047 char **argv, int assignment_cnt,
3048 char **argv_expanded)
3052 /* Case when we are here: ... | var=val | ... */
3053 if (!argv[assignment_cnt])
3054 _exit(EXIT_SUCCESS);
3056 new_env = expand_assignments(argv, assignment_cnt);
3058 set_vars_and_save_old(new_env);
3059 free(new_env); /* optional */
3060 /* we can also destroy set_vars_and_save_old's return value,
3063 nommu_save->new_env = new_env;
3064 nommu_save->old_vars = set_vars_and_save_old(new_env);
3066 if (argv_expanded) {
3067 argv = argv_expanded;
3069 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3071 nommu_save->argv = argv;
3075 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3076 if (strchr(argv[0], '/') != NULL)
3080 /* On NOMMU, we must never block!
3081 * Example: { sleep 99999 | read line } & echo Ok
3082 * read builtin will block on read syscall, leaving parent blocked
3083 * in vfork. Therefore we can't do this:
3086 /* Check if the command matches any of the builtins.
3087 * Depending on context, this might be redundant. But it's
3088 * easier to waste a few CPU cycles than it is to figure out
3089 * if this is one of those cases.
3093 const struct built_in_command *x = find_builtin(argv[0]);
3095 rcode = x->function(argv);
3101 #if ENABLE_HUSH_FUNCTIONS
3102 /* Check if the command matches any functions */
3104 const struct function *funcp = find_function(argv[0]);
3106 exec_function(nommu_save, funcp, argv);
3111 #if ENABLE_FEATURE_SH_STANDALONE
3112 /* Check if the command matches any busybox applets */
3114 int a = find_applet_by_name(argv[0]);
3116 # if BB_MMU /* see above why on NOMMU it is not allowed */
3117 if (APPLET_IS_NOEXEC(a)) {
3118 debug_printf_exec("running applet '%s'\n", argv[0]);
3119 run_applet_no_and_exit(a, argv);
3122 /* Re-exec ourselves */
3123 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3124 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3125 execv(bb_busybox_exec_path, argv);
3126 /* If they called chroot or otherwise made the binary no longer
3127 * executable, fall through */
3132 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3135 debug_printf_exec("execing '%s'\n", argv[0]);
3136 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3137 execvp(argv[0], argv);
3138 bb_perror_msg("can't execute '%s'", argv[0]);
3139 _exit(EXIT_FAILURE);
3142 /* Called after [v]fork() in run_pipe
3144 static void pseudo_exec(nommu_save_t *nommu_save,
3145 struct command *command,
3146 char **argv_expanded) NORETURN;
3147 static void pseudo_exec(nommu_save_t *nommu_save,
3148 struct command *command,
3149 char **argv_expanded)
3151 if (command->argv) {
3152 pseudo_exec_argv(nommu_save, command->argv,
3153 command->assignment_cnt, argv_expanded);
3156 if (command->group) {
3157 /* Cases when we are here:
3160 * ... | ( list ) | ...
3161 * ... | { list } | ...
3165 debug_printf_exec("pseudo_exec: run_list\n");
3166 reset_traps_to_defaults();
3167 rcode = run_list(command->group);
3168 /* OK to leak memory by not calling free_pipe_list,
3169 * since this process is about to exit */
3172 re_execute_shell(&nommu_save->argv_from_re_execing,
3173 command->group_as_string,
3179 /* Case when we are here: ... | >file */
3180 debug_printf_exec("pseudo_exec'ed null command\n");
3181 _exit(EXIT_SUCCESS);
3185 static const char *get_cmdtext(struct pipe *pi)
3191 /* This is subtle. ->cmdtext is created only on first backgrounding.
3192 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3193 * On subsequent bg argv is trashed, but we won't use it */
3196 argv = pi->cmds[0].argv;
3197 if (!argv || !argv[0]) {
3198 pi->cmdtext = xzalloc(1);
3204 len += strlen(*argv) + 1;
3208 argv = pi->cmds[0].argv;
3210 len = strlen(*argv);
3211 memcpy(p, *argv, len);
3219 static void insert_bg_job(struct pipe *pi)
3221 struct pipe *job, **jobp;
3224 /* Linear search for the ID of the job to use */
3226 for (job = G.job_list; job; job = job->next)
3227 if (job->jobid >= pi->jobid)
3228 pi->jobid = job->jobid + 1;
3230 /* Add job to the list of running jobs */
3232 while ((job = *jobp) != NULL)
3234 job = *jobp = xmalloc(sizeof(*job));
3236 *job = *pi; /* physical copy */
3238 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3239 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3240 for (i = 0; i < pi->num_cmds; i++) {
3241 job->cmds[i].pid = pi->cmds[i].pid;
3242 /* all other fields are not used and stay zero */
3244 job->cmdtext = xstrdup(get_cmdtext(pi));
3246 if (G_interactive_fd)
3247 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3248 /* Last command's pid goes to $! */
3249 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3250 G.last_jobid = job->jobid;
3253 static void remove_bg_job(struct pipe *pi)
3255 struct pipe *prev_pipe;
3257 if (pi == G.job_list) {
3258 G.job_list = pi->next;
3260 prev_pipe = G.job_list;
3261 while (prev_pipe->next != pi)
3262 prev_pipe = prev_pipe->next;
3263 prev_pipe->next = pi->next;
3266 G.last_jobid = G.job_list->jobid;
3271 /* Remove a backgrounded job */
3272 static void delete_finished_bg_job(struct pipe *pi)
3275 pi->stopped_cmds = 0;
3281 /* Check to see if any processes have exited -- if they
3282 * have, figure out why and see if a job has completed */
3283 static int checkjobs(struct pipe* fg_pipe)
3293 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3295 attributes = WUNTRACED;
3296 if (fg_pipe == NULL)
3297 attributes |= WNOHANG;
3300 #if ENABLE_HUSH_FAST
3301 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3302 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3303 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3304 /* There was neither fork nor SIGCHLD since last waitpid */
3305 /* Avoid doing waitpid syscall if possible */
3306 if (!G.we_have_children) {
3310 if (fg_pipe == NULL) { /* is WNOHANG set? */
3311 /* We have children, but they did not exit
3312 * or stop yet (we saw no SIGCHLD) */
3315 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3319 /* Do we do this right?
3320 * bash-3.00# sleep 20 | false
3322 * [3]+ Stopped sleep 20 | false
3323 * bash-3.00# echo $?
3324 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3325 * [hush 1.14.0: yes we do it right]
3332 #if ENABLE_HUSH_FAST
3333 i = G.count_SIGCHLD;
3335 childpid = waitpid(-1, &status, attributes);
3336 if (childpid <= 0) {
3337 if (childpid && errno != ECHILD)
3338 bb_perror_msg("waitpid");
3339 #if ENABLE_HUSH_FAST
3340 else { /* Until next SIGCHLD, waitpid's are useless */
3341 G.we_have_children = (childpid == 0);
3342 G.handled_SIGCHLD = i;
3343 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3348 dead = WIFEXITED(status) || WIFSIGNALED(status);
3351 if (WIFSTOPPED(status))
3352 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3353 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3354 if (WIFSIGNALED(status))
3355 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3356 childpid, WTERMSIG(status), WEXITSTATUS(status));
3357 if (WIFEXITED(status))
3358 debug_printf_jobs("pid %d exited, exitcode %d\n",
3359 childpid, WEXITSTATUS(status));
3361 /* Were we asked to wait for fg pipe? */
3363 for (i = 0; i < fg_pipe->num_cmds; i++) {
3364 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3365 if (fg_pipe->cmds[i].pid != childpid)
3368 fg_pipe->cmds[i].pid = 0;
3369 fg_pipe->alive_cmds--;
3370 if (i == fg_pipe->num_cmds - 1) {
3371 /* last process gives overall exitstatus */
3372 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3373 rcode = WEXITSTATUS(status);
3374 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3375 /* bash prints killing signal's name for *last*
3376 * process in pipe (prints just newline for SIGINT).
3377 * Mimic this. Example: "sleep 5" + ^\
3379 if (WIFSIGNALED(status)) {
3380 int sig = WTERMSIG(status);
3381 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3385 fg_pipe->cmds[i].is_stopped = 1;
3386 fg_pipe->stopped_cmds++;
3388 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3389 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3390 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3391 /* All processes in fg pipe have exited or stopped */
3392 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3393 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3394 * and "killall -STOP cat" */
3395 if (G_interactive_fd) {
3397 if (fg_pipe->alive_cmds)
3398 insert_bg_job(fg_pipe);
3403 /* There are still running processes in the fg pipe */
3404 goto wait_more; /* do waitpid again */
3406 /* it wasnt fg_pipe, look for process in bg pipes */
3410 /* We asked to wait for bg or orphaned children */
3411 /* No need to remember exitcode in this case */
3412 for (pi = G.job_list; pi; pi = pi->next) {
3413 for (i = 0; i < pi->num_cmds; i++) {
3414 if (pi->cmds[i].pid == childpid)
3415 goto found_pi_and_prognum;
3418 /* Happens when shell is used as init process (init=/bin/sh) */
3419 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3420 continue; /* do waitpid again */
3422 found_pi_and_prognum:
3425 pi->cmds[i].pid = 0;
3427 if (!pi->alive_cmds) {
3428 if (G_interactive_fd)
3429 printf(JOB_STATUS_FORMAT, pi->jobid,
3430 "Done", pi->cmdtext);
3431 delete_finished_bg_job(pi);
3435 pi->cmds[i].is_stopped = 1;
3439 } /* while (waitpid succeeds)... */
3445 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3448 int rcode = checkjobs(fg_pipe);
3449 if (G_saved_tty_pgrp) {
3450 /* Job finished, move the shell to the foreground */
3451 p = getpgrp(); /* our process group id */
3452 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3453 tcsetpgrp(G_interactive_fd, p);
3459 /* Start all the jobs, but don't wait for anything to finish.
3462 * Return code is normally -1, when the caller has to wait for children
3463 * to finish to determine the exit status of the pipe. If the pipe
3464 * is a simple builtin command, however, the action is done by the
3465 * time run_pipe returns, and the exit code is provided as the
3468 * Returns -1 only if started some children. IOW: we have to
3469 * mask out retvals of builtins etc with 0xff!
3471 * The only case when we do not need to [v]fork is when the pipe
3472 * is single, non-backgrounded, non-subshell command. Examples:
3473 * cmd ; ... { list } ; ...
3474 * cmd && ... { list } && ...
3475 * cmd || ... { list } || ...
3476 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3477 * or (if SH_STANDALONE) an applet, and we can run the { list }
3478 * with run_list. If it isn't one of these, we fork and exec cmd.
3480 * Cases when we must fork:
3481 * non-single: cmd | cmd
3482 * backgrounded: cmd & { list } &
3483 * subshell: ( list ) [&]
3485 static int run_pipe(struct pipe *pi)
3487 static const char *const null_ptr = NULL;
3490 struct command *command;
3491 char **argv_expanded;
3494 /* it is not always needed, but we aim to smaller code */
3495 int squirrel[] = { -1, -1, -1 };
3498 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3501 IF_HUSH_JOB(pi->pgrp = -1;)
3502 pi->stopped_cmds = 0;
3503 command = &(pi->cmds[0]);
3504 argv_expanded = NULL;
3506 if (pi->num_cmds != 1
3507 || pi->followup == PIPE_BG
3508 || command->grp_type == GRP_SUBSHELL
3515 debug_printf_exec(": group:%p argv:'%s'\n",
3516 command->group, command->argv ? command->argv[0] : "NONE");
3518 if (command->group) {
3519 #if ENABLE_HUSH_FUNCTIONS
3520 if (command->grp_type == GRP_FUNCTION) {
3521 /* "executing" func () { list } */
3522 struct function *funcp;
3524 funcp = new_function(command->argv[0]);
3525 /* funcp->name is already set to argv[0] */
3526 funcp->body = command->group;
3528 funcp->body_as_string = command->group_as_string;
3529 command->group_as_string = NULL;
3531 command->group = NULL;
3532 command->argv[0] = NULL;
3533 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3534 funcp->parent_cmd = command;
3535 command->child_func = funcp;
3537 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3539 return EXIT_SUCCESS;
3543 debug_printf("non-subshell group\n");
3544 rcode = 1; /* exitcode if redir failed */
3545 if (setup_redirects(command, squirrel) == 0) {
3546 debug_printf_exec(": run_list\n");
3547 rcode = run_list(command->group) & 0xff;
3549 restore_redirects(squirrel);
3550 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3552 debug_printf_exec("run_pipe: return %d\n", rcode);
3556 argv = command->argv ? command->argv : (char **) &null_ptr;
3558 const struct built_in_command *x;
3559 #if ENABLE_HUSH_FUNCTIONS
3560 const struct function *funcp;
3564 char **new_env = NULL;
3565 struct variable *old_vars = NULL;
3567 if (argv[command->assignment_cnt] == NULL) {
3568 /* Assignments, but no command */
3569 /* Ensure redirects take effect. Try "a=t >file" */
3570 rcode = setup_redirects(command, squirrel);
3571 restore_redirects(squirrel);
3572 /* Set shell variables */
3574 p = expand_string_to_string(*argv);
3575 debug_printf_exec("set shell var:'%s'->'%s'\n",
3577 set_local_var(p, 0, 0);
3580 /* Do we need to flag set_local_var() errors?
3581 * "assignment to readonly var" and "putenv error"
3583 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3585 debug_printf_exec("run_pipe: return %d\n", rcode);
3589 /* Expand the rest into (possibly) many strings each */
3590 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3592 x = find_builtin(argv_expanded[0]);
3593 #if ENABLE_HUSH_FUNCTIONS
3596 funcp = find_function(argv_expanded[0]);
3600 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3601 debug_printf("exec with redirects only\n");
3602 rcode = setup_redirects(command, NULL);
3603 goto clean_up_and_ret1;
3606 /* setup_redirects acts on file descriptors, not FILEs.
3607 * This is perfect for work that comes after exec().
3608 * Is it really safe for inline use? Experimentally,
3609 * things seem to work. */
3610 rcode = setup_redirects(command, squirrel);
3612 new_env = expand_assignments(argv, command->assignment_cnt);
3613 old_vars = set_vars_and_save_old(new_env);
3615 debug_printf_exec(": builtin '%s' '%s'...\n",
3616 x->cmd, argv_expanded[1]);
3617 rcode = x->function(argv_expanded) & 0xff;
3620 #if ENABLE_HUSH_FUNCTIONS
3622 debug_printf_exec(": function '%s' '%s'...\n",
3623 funcp->name, argv_expanded[1]);
3624 rcode = run_function(funcp, argv_expanded) & 0xff;
3628 #if ENABLE_FEATURE_SH_STANDALONE
3631 restore_redirects(squirrel);
3632 unset_vars(new_env);
3635 free(argv_expanded);
3636 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3638 debug_printf_exec("run_pipe return %d\n", rcode);
3642 #if ENABLE_FEATURE_SH_STANDALONE
3643 i = find_applet_by_name(argv_expanded[0]);
3644 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3645 rcode = setup_redirects(command, squirrel);
3647 new_env = expand_assignments(argv, command->assignment_cnt);
3648 old_vars = set_vars_and_save_old(new_env);
3649 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3650 argv_expanded[0], argv_expanded[1]);
3651 rcode = run_nofork_applet(i, argv_expanded);
3653 goto clean_up_and_ret;
3656 /* It is neither builtin nor applet. We must fork. */
3660 /* NB: argv_expanded may already be created, and that
3661 * might include `cmd` runs! Do not rerun it! We *must*
3662 * use argv_expanded if it's non-NULL */
3664 /* Going to fork a child per each pipe member */
3668 for (i = 0; i < pi->num_cmds; i++) {
3669 struct fd_pair pipefds;
3671 volatile nommu_save_t nommu_save;
3672 nommu_save.new_env = NULL;
3673 nommu_save.old_vars = NULL;
3674 nommu_save.argv = NULL;
3675 nommu_save.argv_from_re_execing = NULL;
3677 command = &(pi->cmds[i]);
3678 if (command->argv) {
3679 debug_printf_exec(": pipe member '%s' '%s'...\n",
3680 command->argv[0], command->argv[1]);
3682 debug_printf_exec(": pipe member with no argv\n");
3685 /* pipes are inserted between pairs of commands */
3688 if ((i + 1) < pi->num_cmds)
3689 xpiped_pair(pipefds);
3691 command->pid = BB_MMU ? fork() : vfork();
3692 if (!command->pid) { /* child */
3694 disable_restore_tty_pgrp_on_exit();
3696 /* Every child adds itself to new process group
3697 * with pgid == pid_of_first_child_in_pipe */
3698 if (G.run_list_level == 1 && G_interactive_fd) {
3701 if (pgrp < 0) /* true for 1st process only */
3703 if (setpgid(0, pgrp) == 0
3704 && pi->followup != PIPE_BG
3705 && G_saved_tty_pgrp /* we have ctty */
3707 /* We do it in *every* child, not just first,
3709 tcsetpgrp(G_interactive_fd, pgrp);
3713 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
3714 /* 1st cmd in backgrounded pipe
3715 * should have its stdin /dev/null'ed */
3717 if (open(bb_dev_null, O_RDONLY))
3718 xopen("/", O_RDONLY);
3720 xmove_fd(nextin, 0);
3722 xmove_fd(pipefds.wr, 1);
3725 /* Like bash, explicit redirects override pipes,
3726 * and the pipe fd is available for dup'ing. */
3727 if (setup_redirects(command, NULL))
3730 /* Restore default handlers just prior to exec */
3731 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3733 /* Stores to nommu_save list of env vars putenv'ed
3734 * (NOMMU, on MMU we don't need that) */
3735 /* cast away volatility... */
3736 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3737 /* pseudo_exec() does not return */
3740 /* parent or error */
3741 #if ENABLE_HUSH_FAST
3743 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3745 enable_restore_tty_pgrp_on_exit();
3747 /* Clean up after vforked child */
3748 free(nommu_save.argv);
3749 free(nommu_save.argv_from_re_execing);
3750 unset_vars(nommu_save.new_env);
3751 add_vars(nommu_save.old_vars);
3753 free(argv_expanded);
3754 argv_expanded = NULL;
3755 if (command->pid < 0) { /* [v]fork failed */
3756 /* Clearly indicate, was it fork or vfork */
3757 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3761 /* Second and next children need to know pid of first one */
3763 pi->pgrp = command->pid;
3769 if ((i + 1) < pi->num_cmds)
3771 /* Pass read (output) pipe end to next iteration */
3772 nextin = pipefds.rd;
3775 if (!pi->alive_cmds) {
3777 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3782 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3786 #ifndef debug_print_tree
3787 static void debug_print_tree(struct pipe *pi, int lvl)
3789 static const char *const PIPE[] = {
3795 static const char *RES[] = {
3796 [RES_NONE ] = "NONE" ,
3799 [RES_THEN ] = "THEN" ,
3800 [RES_ELIF ] = "ELIF" ,
3801 [RES_ELSE ] = "ELSE" ,
3804 #if ENABLE_HUSH_LOOPS
3805 [RES_FOR ] = "FOR" ,
3806 [RES_WHILE] = "WHILE",
3807 [RES_UNTIL] = "UNTIL",
3809 [RES_DONE ] = "DONE" ,
3811 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3814 #if ENABLE_HUSH_CASE
3815 [RES_CASE ] = "CASE" ,
3816 [RES_CASE_IN ] = "CASE_IN" ,
3817 [RES_MATCH] = "MATCH",
3818 [RES_CASE_BODY] = "CASE_BODY",
3819 [RES_ESAC ] = "ESAC" ,
3821 [RES_XXXX ] = "XXXX" ,
3822 [RES_SNTX ] = "SNTX" ,
3824 static const char *const GRPTYPE[] = {
3827 #if ENABLE_HUSH_FUNCTIONS
3836 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3837 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3839 while (prn < pi->num_cmds) {
3840 struct command *command = &pi->cmds[prn];
3841 char **argv = command->argv;
3843 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3845 command->assignment_cnt);
3846 if (command->group) {
3847 fprintf(stderr, " group %s: (argv=%p)\n",
3848 GRPTYPE[command->grp_type],
3850 debug_print_tree(command->group, lvl+1);
3854 if (argv) while (*argv) {
3855 fprintf(stderr, " '%s'", *argv);
3858 fprintf(stderr, "\n");
3867 /* NB: called by pseudo_exec, and therefore must not modify any
3868 * global data until exec/_exit (we can be a child after vfork!) */
3869 static int run_list(struct pipe *pi)
3871 #if ENABLE_HUSH_CASE
3872 char *case_word = NULL;
3874 #if ENABLE_HUSH_LOOPS
3875 struct pipe *loop_top = NULL;
3876 char *for_varname = NULL;
3877 char **for_lcur = NULL;
3878 char **for_list = NULL;
3880 smallint last_followup;
3882 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3883 smalluint cond_code = 0;
3885 enum { cond_code = 0 };
3888 smallint rword; /* enum reserved_style */
3889 smallint last_rword; /* ditto */
3892 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3895 #if ENABLE_HUSH_LOOPS
3896 /* Check syntax for "for" */
3897 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3898 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3900 /* current word is FOR or IN (BOLD in comments below) */
3901 if (cpipe->next == NULL) {
3902 syntax_error("malformed for");
3904 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3907 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3908 if (cpipe->next->res_word == RES_DO)
3910 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3911 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3912 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3914 syntax_error("malformed for");
3916 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3922 /* Past this point, all code paths should jump to ret: label
3923 * in order to return, no direct "return" statements please.
3924 * This helps to ensure that no memory is leaked. */
3932 last_rword = RES_XXXX;
3934 last_followup = PIPE_SEQ;
3935 rcode = G.last_exitcode;
3937 /* Go through list of pipes, (maybe) executing them. */
3938 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3942 IF_HAS_KEYWORDS(rword = pi->res_word;)
3943 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3944 rword, cond_code, last_rword);
3945 #if ENABLE_HUSH_LOOPS
3946 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3947 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3949 /* start of a loop: remember where loop starts */
3954 /* Still in the same "if...", "then..." or "do..." branch? */
3955 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3956 if ((rcode == 0 && last_followup == PIPE_OR)
3957 || (rcode != 0 && last_followup == PIPE_AND)
3959 /* It is "<true> || CMD" or "<false> && CMD"
3960 * and we should not execute CMD */
3961 debug_printf_exec("skipped cmd because of || or &&\n");
3962 last_followup = pi->followup;
3966 last_followup = pi->followup;
3967 IF_HAS_KEYWORDS(last_rword = rword;)
3970 if (rword == RES_THEN) {
3971 /* if false; then ... fi has exitcode 0! */
3972 G.last_exitcode = rcode = EXIT_SUCCESS;
3973 /* "if <false> THEN cmd": skip cmd */
3977 if (rword == RES_ELSE || rword == RES_ELIF) {
3978 /* "if <true> then ... ELSE/ELIF cmd":
3979 * skip cmd and all following ones */
3984 #if ENABLE_HUSH_LOOPS
3985 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3987 /* first loop through for */
3989 static const char encoded_dollar_at[] ALIGN1 = {
3990 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3991 }; /* encoded representation of "$@" */
3992 static const char *const encoded_dollar_at_argv[] = {
3993 encoded_dollar_at, NULL
3994 }; /* argv list with one element: "$@" */
3997 vals = (char**)encoded_dollar_at_argv;
3998 if (pi->next->res_word == RES_IN) {
3999 /* if no variable values after "in" we skip "for" */
4000 if (!pi->next->cmds[0].argv) {
4001 G.last_exitcode = rcode = EXIT_SUCCESS;
4002 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4005 vals = pi->next->cmds[0].argv;
4006 } /* else: "for var; do..." -> assume "$@" list */
4007 /* create list of variable values */
4008 debug_print_strings("for_list made from", vals);
4009 for_list = expand_strvec_to_strvec(vals);
4010 for_lcur = for_list;
4011 debug_print_strings("for_list", for_list);
4012 for_varname = pi->cmds[0].argv[0];
4013 pi->cmds[0].argv[0] = NULL;
4015 free(pi->cmds[0].argv[0]);
4017 /* "for" loop is over, clean up */
4021 pi->cmds[0].argv[0] = for_varname;
4024 /* Insert next value from for_lcur */
4025 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4026 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
4027 pi->cmds[0].assignment_cnt = 1;
4029 if (rword == RES_IN) {
4030 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4032 if (rword == RES_DONE) {
4033 continue; /* "done" has no cmds too */
4036 #if ENABLE_HUSH_CASE
4037 if (rword == RES_CASE) {
4038 case_word = expand_strvec_to_string(pi->cmds->argv);
4041 if (rword == RES_MATCH) {
4044 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4046 /* all prev words didn't match, does this one match? */
4047 argv = pi->cmds->argv;
4049 char *pattern = expand_string_to_string(*argv);
4050 /* TODO: which FNM_xxx flags to use? */
4051 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4053 if (cond_code == 0) { /* match! we will execute this branch */
4054 free(case_word); /* make future "word)" stop */
4062 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4064 continue; /* not matched yet, skip this pipe */
4067 /* Just pressing <enter> in shell should check for jobs.
4068 * OTOH, in non-interactive shell this is useless
4069 * and only leads to extra job checks */
4070 if (pi->num_cmds == 0) {
4071 if (G_interactive_fd)
4072 goto check_jobs_and_continue;
4076 /* After analyzing all keywords and conditions, we decided
4077 * to execute this pipe. NB: have to do checkjobs(NULL)
4078 * after run_pipe to collect any background children,
4079 * even if list execution is to be stopped. */
4080 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4083 #if ENABLE_HUSH_LOOPS
4084 G.flag_break_continue = 0;
4086 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4088 /* We ran a builtin, function, or group.
4089 * rcode is already known
4090 * and we don't need to wait for anything. */
4091 G.last_exitcode = rcode;
4092 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4093 check_and_run_traps(0);
4094 #if ENABLE_HUSH_LOOPS
4095 /* Was it "break" or "continue"? */
4096 if (G.flag_break_continue) {
4097 smallint fbc = G.flag_break_continue;
4098 /* We might fall into outer *loop*,
4099 * don't want to break it too */
4101 G.depth_break_continue--;
4102 if (G.depth_break_continue == 0)
4103 G.flag_break_continue = 0;
4104 /* else: e.g. "continue 2" should *break* once, *then* continue */
4105 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4106 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4107 goto check_jobs_and_break;
4108 /* "continue": simulate end of loop */
4113 #if ENABLE_HUSH_FUNCTIONS
4114 if (G.flag_return_in_progress == 1)
4115 goto check_jobs_and_break;
4117 } else if (pi->followup == PIPE_BG) {
4118 /* What does bash do with attempts to background builtins? */
4119 /* even bash 3.2 doesn't do that well with nested bg:
4120 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4121 * I'm NOT treating inner &'s as jobs */
4122 check_and_run_traps(0);
4124 if (G.run_list_level == 1)
4127 G.last_exitcode = rcode = EXIT_SUCCESS;
4128 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4131 if (G.run_list_level == 1 && G_interactive_fd) {
4132 /* Waits for completion, then fg's main shell */
4133 rcode = checkjobs_and_fg_shell(pi);
4134 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4135 check_and_run_traps(0);
4138 { /* This one just waits for completion */
4139 rcode = checkjobs(pi);
4140 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4141 check_and_run_traps(0);
4143 G.last_exitcode = rcode;
4147 /* Analyze how result affects subsequent commands */
4149 if (rword == RES_IF || rword == RES_ELIF)
4152 #if ENABLE_HUSH_LOOPS
4153 /* Beware of "while false; true; do ..."! */
4154 if (pi->next && pi->next->res_word == RES_DO) {
4155 if (rword == RES_WHILE) {
4157 /* "while false; do...done" - exitcode 0 */
4158 G.last_exitcode = rcode = EXIT_SUCCESS;
4159 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4160 goto check_jobs_and_break;
4163 if (rword == RES_UNTIL) {
4165 debug_printf_exec(": until expr is true: breaking\n");
4166 check_jobs_and_break:
4174 check_jobs_and_continue:
4181 #if ENABLE_HUSH_LOOPS
4186 #if ENABLE_HUSH_CASE
4190 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4194 /* Select which version we will use */
4195 static int run_and_free_list(struct pipe *pi)
4198 debug_printf_exec("run_and_free_list entered\n");
4200 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4201 rcode = run_list(pi);
4203 /* free_pipe_list has the side effect of clearing memory.
4204 * In the long run that function can be merged with run_list,
4205 * but doing that now would hobble the debugging effort. */
4207 debug_printf_exec("run_and_free_list return %d\n", rcode);
4212 static struct pipe *new_pipe(void)
4215 pi = xzalloc(sizeof(struct pipe));
4216 /*pi->followup = 0; - deliberately invalid value */
4217 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4221 /* Command (member of a pipe) is complete, or we start a new pipe
4222 * if ctx->command is NULL.
4223 * No errors possible here.
4225 static int done_command(struct parse_context *ctx)
4227 /* The command is really already in the pipe structure, so
4228 * advance the pipe counter and make a new, null command. */
4229 struct pipe *pi = ctx->pipe;
4230 struct command *command = ctx->command;
4233 if (IS_NULL_CMD(command)) {
4234 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4238 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4239 //debug_print_tree(ctx->list_head, 20);
4241 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4244 /* Only real trickiness here is that the uncommitted
4245 * command structure is not counted in pi->num_cmds. */
4246 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4247 ctx->command = command = &pi->cmds[pi->num_cmds];
4249 memset(command, 0, sizeof(*command));
4250 return pi->num_cmds; /* used only for 0/nonzero check */
4253 static void done_pipe(struct parse_context *ctx, pipe_style type)
4257 debug_printf_parse("done_pipe entered, followup %d\n", type);
4258 /* Close previous command */
4259 not_null = done_command(ctx);
4260 ctx->pipe->followup = type;
4262 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4263 ctx->ctx_inverted = 0;
4264 ctx->pipe->res_word = ctx->ctx_res_w;
4267 /* Without this check, even just <enter> on command line generates
4268 * tree of three NOPs (!). Which is harmless but annoying.
4269 * IOW: it is safe to do it unconditionally. */
4272 || ctx->ctx_res_w == RES_FI
4274 #if ENABLE_HUSH_LOOPS
4275 || ctx->ctx_res_w == RES_DONE
4276 || ctx->ctx_res_w == RES_FOR
4277 || ctx->ctx_res_w == RES_IN
4279 #if ENABLE_HUSH_CASE
4280 || ctx->ctx_res_w == RES_ESAC
4284 debug_printf_parse("done_pipe: adding new pipe: "
4285 "not_null:%d ctx->ctx_res_w:%d\n",
4286 not_null, ctx->ctx_res_w);
4288 ctx->pipe->next = new_p;
4290 /* RES_THEN, RES_DO etc are "sticky" -
4291 * they remain set for pipes inside if/while.
4292 * This is used to control execution.
4293 * RES_FOR and RES_IN are NOT sticky (needed to support
4294 * cases where variable or value happens to match a keyword):
4296 #if ENABLE_HUSH_LOOPS
4297 if (ctx->ctx_res_w == RES_FOR
4298 || ctx->ctx_res_w == RES_IN)
4299 ctx->ctx_res_w = RES_NONE;
4301 #if ENABLE_HUSH_CASE
4302 if (ctx->ctx_res_w == RES_MATCH)
4303 ctx->ctx_res_w = RES_CASE_BODY;
4304 if (ctx->ctx_res_w == RES_CASE)
4305 ctx->ctx_res_w = RES_CASE_IN;
4307 ctx->command = NULL; /* trick done_command below */
4308 /* Create the memory for command, roughly:
4309 * ctx->pipe->cmds = new struct command;
4310 * ctx->command = &ctx->pipe->cmds[0];
4313 //debug_print_tree(ctx->list_head, 10);
4315 debug_printf_parse("done_pipe return\n");
4318 static void initialize_context(struct parse_context *ctx)
4320 memset(ctx, 0, sizeof(*ctx));
4321 ctx->pipe = ctx->list_head = new_pipe();
4322 /* Create the memory for command, roughly:
4323 * ctx->pipe->cmds = new struct command;
4324 * ctx->command = &ctx->pipe->cmds[0];
4329 /* If a reserved word is found and processed, parse context is modified
4330 * and 1 is returned.
4333 struct reserved_combo {
4336 unsigned char assignment_flag;
4340 FLAG_END = (1 << RES_NONE ),
4342 FLAG_IF = (1 << RES_IF ),
4343 FLAG_THEN = (1 << RES_THEN ),
4344 FLAG_ELIF = (1 << RES_ELIF ),
4345 FLAG_ELSE = (1 << RES_ELSE ),
4346 FLAG_FI = (1 << RES_FI ),
4348 #if ENABLE_HUSH_LOOPS
4349 FLAG_FOR = (1 << RES_FOR ),
4350 FLAG_WHILE = (1 << RES_WHILE),
4351 FLAG_UNTIL = (1 << RES_UNTIL),
4352 FLAG_DO = (1 << RES_DO ),
4353 FLAG_DONE = (1 << RES_DONE ),
4354 FLAG_IN = (1 << RES_IN ),
4356 #if ENABLE_HUSH_CASE
4357 FLAG_MATCH = (1 << RES_MATCH),
4358 FLAG_ESAC = (1 << RES_ESAC ),
4360 FLAG_START = (1 << RES_XXXX ),
4363 static const struct reserved_combo* match_reserved_word(o_string *word)
4365 /* Mostly a list of accepted follow-up reserved words.
4366 * FLAG_END means we are done with the sequence, and are ready
4367 * to turn the compound list into a command.
4368 * FLAG_START means the word must start a new compound list.
4370 static const struct reserved_combo reserved_list[] = {
4372 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4373 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4374 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4375 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4376 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4377 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4379 #if ENABLE_HUSH_LOOPS
4380 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4381 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4382 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4383 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4384 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4385 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4387 #if ENABLE_HUSH_CASE
4388 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4389 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4392 const struct reserved_combo *r;
4394 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4395 if (strcmp(word->data, r->literal) == 0)
4400 /* Return 0: not a keyword, 1: keyword
4402 static int reserved_word(o_string *word, struct parse_context *ctx)
4404 #if ENABLE_HUSH_CASE
4405 static const struct reserved_combo reserved_match = {
4406 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4409 const struct reserved_combo *r;
4413 r = match_reserved_word(word);
4417 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4418 #if ENABLE_HUSH_CASE
4419 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
4420 /* "case word IN ..." - IN part starts first MATCH part */
4421 r = &reserved_match;
4424 if (r->flag == 0) { /* '!' */
4425 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4426 syntax_error("! ! command");
4427 ctx->ctx_res_w = RES_SNTX;
4429 ctx->ctx_inverted = 1;
4432 if (r->flag & FLAG_START) {
4433 struct parse_context *old;
4435 old = xmalloc(sizeof(*old));
4436 debug_printf_parse("push stack %p\n", old);
4437 *old = *ctx; /* physical copy */
4438 initialize_context(ctx);
4440 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4441 syntax_error_at(word->data);
4442 ctx->ctx_res_w = RES_SNTX;
4445 /* "{...} fi" is ok. "{...} if" is not
4447 * if { echo foo; } then { echo bar; } fi */
4448 if (ctx->command->group)
4449 done_pipe(ctx, PIPE_SEQ);
4452 ctx->ctx_res_w = r->res;
4453 ctx->old_flag = r->flag;
4454 word->o_assignment = r->assignment_flag;
4456 if (ctx->old_flag & FLAG_END) {
4457 struct parse_context *old;
4459 done_pipe(ctx, PIPE_SEQ);
4460 debug_printf_parse("pop stack %p\n", ctx->stack);
4462 old->command->group = ctx->list_head;
4463 old->command->grp_type = GRP_NORMAL;
4465 o_addstr(&old->as_string, ctx->as_string.data);
4466 o_free_unsafe(&ctx->as_string);
4467 old->command->group_as_string = xstrdup(old->as_string.data);
4468 debug_printf_parse("pop, remembering as:'%s'\n",
4469 old->command->group_as_string);
4471 *ctx = *old; /* physical copy */
4478 /* Word is complete, look at it and update parsing context.
4479 * Normal return is 0. Syntax errors return 1.
4480 * Note: on return, word is reset, but not o_free'd!
4482 static int done_word(o_string *word, struct parse_context *ctx)
4484 struct command *command = ctx->command;
4486 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4487 if (word->length == 0 && word->o_quoted == 0) {
4488 debug_printf_parse("done_word return 0: true null, ignored\n");
4492 if (ctx->pending_redirect) {
4493 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4494 * only if run as "bash", not "sh" */
4495 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4497 * ...the word that follows the redirection operator
4498 * shall be subjected to tilde expansion, parameter expansion,
4499 * command substitution, arithmetic expansion, and quote
4500 * removal. Pathname expansion shall not be performed
4501 * on the word by a non-interactive shell; an interactive
4502 * shell may perform it, but shall do so only when
4503 * the expansion would result in one word."
4505 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4506 /* Cater for >\file case:
4507 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4508 * Same with heredocs:
4509 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4511 unbackslash(ctx->pending_redirect->rd_filename);
4512 /* Is it <<"HEREDOC"? */
4513 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4516 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4518 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4519 ctx->pending_redirect = NULL;
4521 /* If this word wasn't an assignment, next ones definitely
4522 * can't be assignments. Even if they look like ones. */
4523 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4524 && word->o_assignment != WORD_IS_KEYWORD
4526 word->o_assignment = NOT_ASSIGNMENT;
4528 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4529 command->assignment_cnt++;
4530 word->o_assignment = MAYBE_ASSIGNMENT;
4534 # if ENABLE_HUSH_CASE
4535 if (ctx->ctx_dsemicolon
4536 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4538 /* already done when ctx_dsemicolon was set to 1: */
4539 /* ctx->ctx_res_w = RES_MATCH; */
4540 ctx->ctx_dsemicolon = 0;
4543 if (!command->argv /* if it's the first word... */
4544 # if ENABLE_HUSH_LOOPS
4545 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4546 && ctx->ctx_res_w != RES_IN
4548 # if ENABLE_HUSH_CASE
4549 && ctx->ctx_res_w != RES_CASE
4552 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4553 if (reserved_word(word, ctx)) {
4554 o_reset_to_empty_unquoted(word);
4555 debug_printf_parse("done_word return %d\n",
4556 (ctx->ctx_res_w == RES_SNTX));
4557 return (ctx->ctx_res_w == RES_SNTX);
4561 if (command->group) {
4562 /* "{ echo foo; } echo bar" - bad */
4563 syntax_error_at(word->data);
4564 debug_printf_parse("done_word return 1: syntax error, "
4565 "groups and arglists don't mix\n");
4568 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4569 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4570 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4571 /* (otherwise it's known to be not empty and is already safe) */
4573 /* exclude "$@" - it can expand to no word despite "" */
4574 char *p = word->data;
4575 while (p[0] == SPECIAL_VAR_SYMBOL
4576 && (p[1] & 0x7f) == '@'
4577 && p[2] == SPECIAL_VAR_SYMBOL
4581 if (p == word->data || p[0] != '\0') {
4582 /* saw no "$@", or not only "$@" but some
4583 * real text is there too */
4584 /* insert "empty variable" reference, this makes
4585 * e.g. "", $empty"" etc to not disappear */
4586 o_addchr(word, SPECIAL_VAR_SYMBOL);
4587 o_addchr(word, SPECIAL_VAR_SYMBOL);
4590 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4591 debug_print_strings("word appended to argv", command->argv);
4594 #if ENABLE_HUSH_LOOPS
4595 if (ctx->ctx_res_w == RES_FOR) {
4597 || !is_well_formed_var_name(command->argv[0], '\0')
4599 /* bash says just "not a valid identifier" */
4600 syntax_error("not a valid identifier in for");
4603 /* Force FOR to have just one word (variable name) */
4604 /* NB: basically, this makes hush see "for v in ..."
4605 * syntax as if it is "for v; in ...". FOR and IN become
4606 * two pipe structs in parse tree. */
4607 done_pipe(ctx, PIPE_SEQ);
4610 #if ENABLE_HUSH_CASE
4611 /* Force CASE to have just one word */
4612 if (ctx->ctx_res_w == RES_CASE) {
4613 done_pipe(ctx, PIPE_SEQ);
4617 o_reset_to_empty_unquoted(word);
4619 debug_printf_parse("done_word return 0\n");
4624 /* Peek ahead in the input to find out if we have a "&n" construct,
4625 * as in "2>&1", that represents duplicating a file descriptor.
4627 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4628 * REDIRFD_SYNTAX_ERR if syntax error,
4629 * REDIRFD_TO_FILE if no & was seen,
4630 * or the number found.
4633 #define parse_redir_right_fd(as_string, input) \
4634 parse_redir_right_fd(input)
4636 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4642 return REDIRFD_TO_FILE;
4644 ch = i_getch(input); /* get the & */
4645 nommu_addchr(as_string, ch);
4648 ch = i_getch(input);
4649 nommu_addchr(as_string, ch);
4650 return REDIRFD_CLOSE;
4654 while (ch != EOF && isdigit(ch)) {
4655 d = d*10 + (ch-'0');
4657 ch = i_getch(input);
4658 nommu_addchr(as_string, ch);
4663 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4665 bb_error_msg("ambiguous redirect");
4666 return REDIRFD_SYNTAX_ERR;
4669 /* Return code is 0 normal, 1 if a syntax error is detected
4671 static int parse_redirect(struct parse_context *ctx,
4674 struct in_str *input)
4676 struct command *command = ctx->command;
4677 struct redir_struct *redir;
4678 struct redir_struct **redirp;
4681 dup_num = REDIRFD_TO_FILE;
4682 if (style != REDIRECT_HEREDOC) {
4683 /* Check for a '>&1' type redirect */
4684 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4685 if (dup_num == REDIRFD_SYNTAX_ERR)
4688 int ch = i_peek(input);
4689 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4690 if (dup_num) { /* <<-... */
4691 ch = i_getch(input);
4692 nommu_addchr(&ctx->as_string, ch);
4697 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4698 int ch = i_peek(input);
4700 /* >|FILE redirect ("clobbering" >).
4701 * Since we do not support "set -o noclobber" yet,
4702 * >| and > are the same for now. Just eat |.
4704 ch = i_getch(input);
4705 nommu_addchr(&ctx->as_string, ch);
4709 /* Create a new redir_struct and append it to the linked list */
4710 redirp = &command->redirects;
4711 while ((redir = *redirp) != NULL) {
4712 redirp = &(redir->next);
4714 *redirp = redir = xzalloc(sizeof(*redir));
4715 /* redir->next = NULL; */
4716 /* redir->rd_filename = NULL; */
4717 redir->rd_type = style;
4718 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4720 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4721 redir_table[style].descrip);
4723 redir->rd_dup = dup_num;
4724 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4725 /* Erik had a check here that the file descriptor in question
4726 * is legit; I postpone that to "run time"
4727 * A "-" representation of "close me" shows up as a -3 here */
4728 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4729 redir->rd_fd, redir->rd_dup);
4731 /* Set ctx->pending_redirect, so we know what to do at the
4732 * end of the next parsed word. */
4733 ctx->pending_redirect = redir;
4738 /* If a redirect is immediately preceded by a number, that number is
4739 * supposed to tell which file descriptor to redirect. This routine
4740 * looks for such preceding numbers. In an ideal world this routine
4741 * needs to handle all the following classes of redirects...
4742 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4743 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4744 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4745 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4747 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4749 * ... If n is quoted, the number shall not be recognized as part of
4750 * the redirection expression. For example:
4752 * writes the character 2 into file a"
4753 * We are getting it right by setting ->o_quoted on any \<char>
4755 * A -1 return means no valid number was found,
4756 * the caller should use the appropriate default for this redirection.
4758 static int redirect_opt_num(o_string *o)
4762 if (o->data == NULL)
4764 num = bb_strtou(o->data, NULL, 10);
4765 if (errno || num < 0)
4767 o_reset_to_empty_unquoted(o);
4772 #define fetch_till_str(as_string, input, word, skip_tabs) \
4773 fetch_till_str(input, word, skip_tabs)
4775 static char *fetch_till_str(o_string *as_string,
4776 struct in_str *input,
4780 o_string heredoc = NULL_O_STRING;
4786 ch = i_getch(input);
4787 nommu_addchr(as_string, ch);
4789 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4790 heredoc.data[past_EOL] = '\0';
4791 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4792 return heredoc.data;
4795 o_addchr(&heredoc, ch);
4796 past_EOL = heredoc.length;
4799 ch = i_getch(input);
4800 nommu_addchr(as_string, ch);
4801 } while (skip_tabs && ch == '\t');
4802 } while (ch == '\n');
4805 o_free_unsafe(&heredoc);
4808 o_addchr(&heredoc, ch);
4809 nommu_addchr(as_string, ch);
4813 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4814 * and load them all. There should be exactly heredoc_cnt of them.
4816 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4818 struct pipe *pi = ctx->list_head;
4820 while (pi && heredoc_cnt) {
4822 struct command *cmd = pi->cmds;
4824 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4826 cmd->argv ? cmd->argv[0] : "NONE");
4827 for (i = 0; i < pi->num_cmds; i++) {
4828 struct redir_struct *redir = cmd->redirects;
4830 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4831 i, cmd->argv ? cmd->argv[0] : "NONE");
4833 if (redir->rd_type == REDIRECT_HEREDOC) {
4836 redir->rd_type = REDIRECT_HEREDOC2;
4837 /* redir->dup is (ab)used to indicate <<- */
4838 p = fetch_till_str(&ctx->as_string, input,
4839 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4841 syntax_error("unexpected EOF in here document");
4844 free(redir->rd_filename);
4845 redir->rd_filename = p;
4848 redir = redir->next;
4855 /* Should be 0. If it isn't, it's a parse error */
4857 bb_error_msg_and_die("heredoc BUG 2");
4863 #if ENABLE_HUSH_TICK
4864 static FILE *generate_stream_from_string(const char *s)
4867 int pid, channel[2];
4873 pid = BB_MMU ? fork() : vfork();
4875 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4877 if (pid == 0) { /* child */
4878 disable_restore_tty_pgrp_on_exit();
4879 /* Process substitution is not considered to be usual
4880 * 'command execution'.
4881 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4888 close(channel[0]); /* NB: close _first_, then move fd! */
4889 xmove_fd(channel[1], 1);
4890 /* Prevent it from trying to handle ctrl-z etc */
4891 IF_HUSH_JOB(G.run_list_level = 1;)
4893 reset_traps_to_defaults();
4894 parse_and_run_string(s);
4895 _exit(G.last_exitcode);
4897 /* We re-execute after vfork on NOMMU. This makes this script safe:
4898 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4899 * huge=`cat BIG` # was blocking here forever
4902 re_execute_shell(&to_free,
4910 #if ENABLE_HUSH_FAST
4912 //bb_error_msg("[%d] fork in generate_stream_from_string: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4914 enable_restore_tty_pgrp_on_exit();
4919 pf = fdopen(channel[0], "r");
4923 /* Return code is exit status of the process that is run. */
4924 static int process_command_subs(o_string *dest, const char *s)
4927 struct in_str pipe_str;
4930 pf = generate_stream_from_string(s);
4933 close_on_exec_on(fileno(pf));
4935 /* Now send results of command back into original context */
4936 setup_file_in_str(&pipe_str, pf);
4938 while ((ch = i_getch(&pipe_str)) != EOF) {
4944 o_addchr(dest, '\n');
4947 o_addQchr(dest, ch);
4950 debug_printf("done reading from pipe, pclose()ing\n");
4951 /* Note: we got EOF, and we just close the read end of the pipe.
4952 * We do not wait for the `cmd` child to terminate. bash and ash do.
4954 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4955 * `false`; echo $? - bash outputs "1"
4958 debug_printf("closed FILE from child. return 0\n");
4963 static int parse_group(o_string *dest, struct parse_context *ctx,
4964 struct in_str *input, int ch)
4966 /* dest contains characters seen prior to ( or {.
4967 * Typically it's empty, but for function defs,
4968 * it contains function name (without '()'). */
4969 struct pipe *pipe_list;
4971 struct command *command = ctx->command;
4973 debug_printf_parse("parse_group entered\n");
4974 #if ENABLE_HUSH_FUNCTIONS
4975 if (ch == '(' && !dest->o_quoted) {
4977 if (done_word(dest, ctx))
4980 goto skip; /* (... */
4981 if (command->argv[1]) { /* word word ... (... */
4982 syntax_error_unexpected_ch('(');
4985 /* it is "word(..." or "word (..." */
4987 ch = i_getch(input);
4988 while (ch == ' ' || ch == '\t');
4990 syntax_error_unexpected_ch(ch);
4993 nommu_addchr(&ctx->as_string, ch);
4995 ch = i_getch(input);
4996 while (ch == ' ' || ch == '\t' || ch == '\n');
4998 syntax_error_unexpected_ch(ch);
5001 nommu_addchr(&ctx->as_string, ch);
5002 command->grp_type = GRP_FUNCTION;
5006 if (command->argv /* word [word]{... */
5007 || dest->length /* word{... */
5008 || dest->o_quoted /* ""{... */
5011 debug_printf_parse("parse_group return 1: "
5012 "syntax error, groups and arglists don't mix\n");
5016 #if ENABLE_HUSH_FUNCTIONS
5022 command->grp_type = GRP_SUBSHELL;
5024 /* bash does not allow "{echo...", requires whitespace */
5025 ch = i_getch(input);
5026 if (ch != ' ' && ch != '\t' && ch != '\n') {
5027 syntax_error_unexpected_ch(ch);
5030 nommu_addchr(&ctx->as_string, ch);
5035 char *as_string = NULL;
5037 pipe_list = parse_stream(&as_string, input, endch);
5040 o_addstr(&ctx->as_string, as_string);
5042 /* empty ()/{} or parse error? */
5043 if (!pipe_list || pipe_list == ERR_PTR) {
5044 /* parse_stream already emitted error msg */
5048 debug_printf_parse("parse_group return 1: "
5049 "parse_stream returned %p\n", pipe_list);
5052 command->group = pipe_list;
5054 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5055 command->group_as_string = as_string;
5056 debug_printf_parse("end of group, remembering as:'%s'\n",
5057 command->group_as_string);
5060 debug_printf_parse("parse_group return 0\n");
5062 /* command remains "open", available for possible redirects */
5065 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5066 /* Subroutines for copying $(...) and `...` things */
5067 static void add_till_backquote(o_string *dest, struct in_str *input);
5069 static void add_till_single_quote(o_string *dest, struct in_str *input)
5072 int ch = i_getch(input);
5074 syntax_error_unterm_ch('\'');
5075 /*xfunc_die(); - redundant */
5082 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5083 static void add_till_double_quote(o_string *dest, struct in_str *input)
5086 int ch = i_getch(input);
5088 syntax_error_unterm_ch('"');
5089 /*xfunc_die(); - redundant */
5093 if (ch == '\\') { /* \x. Copy both chars. */
5095 ch = i_getch(input);
5099 add_till_backquote(dest, input);
5103 //if (ch == '$') ...
5106 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5108 * "Within the backquoted style of command substitution, backslash
5109 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5110 * The search for the matching backquote shall be satisfied by the first
5111 * backquote found without a preceding backslash; during this search,
5112 * if a non-escaped backquote is encountered within a shell comment,
5113 * a here-document, an embedded command substitution of the $(command)
5114 * form, or a quoted string, undefined results occur. A single-quoted
5115 * or double-quoted string that begins, but does not end, within the
5116 * "`...`" sequence produces undefined results."
5118 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5120 static void add_till_backquote(o_string *dest, struct in_str *input)
5123 int ch = i_getch(input);
5125 syntax_error_unterm_ch('`');
5126 /*xfunc_die(); - redundant */
5131 /* \x. Copy both chars unless it is \` */
5132 int ch2 = i_getch(input);
5134 syntax_error_unterm_ch('`');
5135 /*xfunc_die(); - redundant */
5137 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5144 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5145 * quoting and nested ()s.
5146 * "With the $(command) style of command substitution, all characters
5147 * following the open parenthesis to the matching closing parenthesis
5148 * constitute the command. Any valid shell script can be used for command,
5149 * except a script consisting solely of redirections which produces
5150 * unspecified results."
5152 * echo $(echo '(TEST)' BEST) (TEST) BEST
5153 * echo $(echo 'TEST)' BEST) TEST) BEST
5154 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5156 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5160 int ch = i_getch(input);
5162 syntax_error_unterm_ch(')');
5163 /*xfunc_die(); - redundant */
5171 if (i_peek(input) == ')') {
5179 add_till_single_quote(dest, input);
5184 add_till_double_quote(dest, input);
5189 /* \x. Copy verbatim. Important for \(, \) */
5190 ch = i_getch(input);
5192 syntax_error_unterm_ch(')');
5193 /*xfunc_die(); - redundant */
5200 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5202 /* Return code: 0 for OK, 1 for syntax error */
5204 #define handle_dollar(as_string, dest, input) \
5205 handle_dollar(dest, input)
5207 static int handle_dollar(o_string *as_string,
5209 struct in_str *input)
5212 int ch = i_peek(input); /* first character after the $ */
5213 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5215 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5217 ch = i_getch(input);
5218 nommu_addchr(as_string, ch);
5220 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5222 debug_printf_parse(": '%c'\n", ch);
5223 o_addchr(dest, ch | quote_mask);
5226 if (!isalnum(ch) && ch != '_')
5228 ch = i_getch(input);
5229 nommu_addchr(as_string, ch);
5231 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5232 } else if (isdigit(ch)) {
5234 ch = i_getch(input);
5235 nommu_addchr(as_string, ch);
5236 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5237 debug_printf_parse(": '%c'\n", ch);
5238 o_addchr(dest, ch | quote_mask);
5239 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5240 } else switch (ch) {
5242 case '!': /* last bg pid */
5243 case '?': /* last exit code */
5244 case '#': /* number of args */
5245 case '*': /* args */
5246 case '@': /* args */
5247 goto make_one_char_var;
5249 bool first_char, all_digits;
5251 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5252 ch = i_getch(input);
5253 nommu_addchr(as_string, ch);
5254 /* TODO: maybe someone will try to escape the '}' */
5259 ch = i_getch(input);
5260 nommu_addchr(as_string, ch);
5267 /* ${#var}: length of var contents */
5277 && ( (all_digits && !isdigit(ch))
5278 || (!all_digits && !isalnum(ch) && ch != '_')
5281 /* handle parameter expansions
5282 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5287 case ':': /* null modifier */
5288 if (expansion == 0) {
5289 debug_printf_parse(": null modifier\n");
5294 case '#': /* remove prefix */
5295 case '%': /* remove suffix */
5296 if (expansion == 0) {
5297 debug_printf_parse(": remove suffix/prefix\n");
5302 case '-': /* default value */
5303 case '=': /* assign default */
5304 case '+': /* alternative */
5305 case '?': /* error indicate */
5306 debug_printf_parse(": parameter expansion\n");
5311 syntax_error_unterm_str("${name}");
5312 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5317 debug_printf_parse(": '%c'\n", ch);
5318 o_addchr(dest, ch | quote_mask);
5322 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5325 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5330 ch = i_getch(input);
5331 nommu_addchr(as_string, ch);
5332 # if ENABLE_SH_MATH_SUPPORT
5333 if (i_peek(input) == '(') {
5334 ch = i_getch(input);
5335 nommu_addchr(as_string, ch);
5336 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5337 o_addchr(dest, /*quote_mask |*/ '+');
5341 add_till_closing_paren(dest, input, true);
5344 o_addstr(as_string, dest->data + pos);
5345 o_addchr(as_string, ')');
5346 o_addchr(as_string, ')');
5349 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5353 # if ENABLE_HUSH_TICK
5354 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5355 o_addchr(dest, quote_mask | '`');
5359 add_till_closing_paren(dest, input, false);
5362 o_addstr(as_string, dest->data + pos);
5363 o_addchr(as_string, '`');
5366 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5372 ch = i_getch(input);
5373 nommu_addchr(as_string, ch);
5375 if (isalnum(ch)) { /* it's $_name or $_123 */
5381 /* $_ Shell or shell script name; or last cmd name */
5382 /* $- Option flags set by set builtin or shell options (-i etc) */
5384 o_addQchr(dest, '$');
5386 debug_printf_parse("handle_dollar return 0\n");
5391 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5392 parse_stream_dquoted(dest, input, dquote_end)
5394 static int parse_stream_dquoted(o_string *as_string,
5396 struct in_str *input,
5403 ch = i_getch(input);
5405 nommu_addchr(as_string, ch);
5406 if (ch == dquote_end) { /* may be only '"' or EOF */
5407 if (dest->o_assignment == NOT_ASSIGNMENT)
5408 dest->o_escape ^= 1;
5409 debug_printf_parse("parse_stream_dquoted return 0\n");
5412 /* note: can't move it above ch == dquote_end check! */
5414 syntax_error_unterm_ch('"');
5415 /*xfunc_die(); - redundant */
5419 next = i_peek(input);
5421 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5422 ch, ch, dest->o_escape);
5425 syntax_error("\\<eof>");
5429 * "The backslash retains its special meaning [in "..."]
5430 * only when followed by one of the following characters:
5431 * $, `, ", \, or <newline>. A double quote may be quoted
5432 * within double quotes by preceding it with a backslash.
5434 if (strchr("$`\"\\\n", next) != NULL) {
5435 ch = i_getch(input);
5437 o_addqchr(dest, ch);
5438 nommu_addchr(as_string, ch);
5441 o_addqchr(dest, '\\');
5442 nommu_addchr(as_string, '\\');
5447 if (handle_dollar(as_string, dest, input) != 0) {
5448 debug_printf_parse("parse_stream_dquoted return 1: "
5449 "handle_dollar returned non-0\n");
5454 #if ENABLE_HUSH_TICK
5456 //int pos = dest->length;
5457 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5458 o_addchr(dest, 0x80 | '`');
5459 add_till_backquote(dest, input);
5460 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5461 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5465 o_addQchr(dest, ch);
5467 && (dest->o_assignment == MAYBE_ASSIGNMENT
5468 || dest->o_assignment == WORD_IS_KEYWORD)
5469 && is_well_formed_var_name(dest->data, '=')
5471 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5477 * Scan input until EOF or end_trigger char.
5478 * Return a list of pipes to execute, or NULL on EOF
5479 * or if end_trigger character is met.
5480 * On syntax error, exit is shell is not interactive,
5481 * reset parsing machinery and start parsing anew,
5482 * or return ERR_PTR.
5484 static struct pipe *parse_stream(char **pstring,
5485 struct in_str *input,
5488 struct parse_context ctx;
5489 o_string dest = NULL_O_STRING;
5493 /* Double-quote state is handled in the state variable is_in_dquote.
5494 * A single-quote triggers a bypass of the main loop until its mate is
5495 * found. When recursing, quote state is passed in via dest->o_escape.
5497 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5498 end_trigger ? : 'X');
5501 G.ifs = get_local_var_value("IFS");
5506 #if ENABLE_HUSH_INTERACTIVE
5507 input->promptmode = 0; /* PS1 */
5509 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5510 initialize_context(&ctx);
5515 const char *is_special;
5519 redir_type redir_style;
5522 /* dest.o_quoted = 1; - already is (see below) */
5523 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5526 /* We reached closing '"' */
5529 ch = i_getch(input);
5530 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5531 ch, ch, dest.o_escape);
5536 syntax_error_unterm_str("here document");
5539 /* end_trigger == '}' case errors out earlier,
5540 * checking only ')' */
5541 if (end_trigger == ')') {
5542 syntax_error_unterm_ch('('); /* exits */
5543 /* goto parse_error; */
5546 if (done_word(&dest, &ctx)) {
5550 done_pipe(&ctx, PIPE_SEQ);
5552 /* If we got nothing... */
5553 /* (this makes bare "&" cmd a no-op.
5554 * bash says: "syntax error near unexpected token '&'") */
5555 if (pi->num_cmds == 0
5556 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5562 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5564 *pstring = ctx.as_string.data;
5566 o_free_unsafe(&ctx.as_string);
5569 debug_printf_parse("parse_stream return %p\n", pi);
5572 nommu_addchr(&ctx.as_string, ch);
5573 is_ifs = strchr(G.ifs, ch);
5574 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5575 "\\$\"" IF_HUSH_TICK("`") /* always special */
5578 if (!is_special && !is_ifs) { /* ordinary char */
5580 o_addQchr(&dest, ch);
5581 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5582 || dest.o_assignment == WORD_IS_KEYWORD)
5584 && is_well_formed_var_name(dest.data, '=')
5586 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5592 if (done_word(&dest, &ctx)) {
5596 #if ENABLE_HUSH_CASE
5597 /* "case ... in <newline> word) ..." -
5598 * newlines are ignored (but ';' wouldn't be) */
5599 if (ctx.command->argv == NULL
5600 && ctx.ctx_res_w == RES_MATCH
5605 /* Treat newline as a command separator. */
5606 done_pipe(&ctx, PIPE_SEQ);
5607 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5609 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5614 dest.o_assignment = MAYBE_ASSIGNMENT;
5616 /* note: if (is_ifs) continue;
5617 * will still trigger for us */
5621 /* "cmd}" or "cmd }..." without semicolon or &:
5622 * } is an ordinary char in this case, even inside { cmd; }
5623 * Pathological example: { ""}; } should exec "}" cmd
5626 if (!IS_NULL_CMD(ctx.command) /* cmd } */
5627 || dest.length != 0 /* word} */
5628 || dest.o_quoted /* ""} */
5632 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5633 goto skip_end_trigger;
5634 /* else: } does terminate a group */
5637 if (end_trigger && end_trigger == ch
5638 && (ch != ';' || heredoc_cnt == 0)
5639 #if ENABLE_HUSH_CASE
5641 || ctx.ctx_res_w != RES_MATCH
5642 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
5647 /* This is technically valid:
5648 * { cat <<HERE; }; echo Ok
5652 * but we don't support this.
5653 * We require heredoc to be in enclosing {}/(),
5656 syntax_error_unterm_str("here document");
5659 if (done_word(&dest, &ctx)) {
5662 done_pipe(&ctx, PIPE_SEQ);
5663 dest.o_assignment = MAYBE_ASSIGNMENT;
5664 /* Do we sit outside of any if's, loops or case's? */
5666 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5670 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5672 *pstring = ctx.as_string.data;
5674 o_free_unsafe(&ctx.as_string);
5677 debug_printf_parse("parse_stream return %p: "
5678 "end_trigger char found\n",
5680 return ctx.list_head;
5689 next = i_peek(input);
5692 /* Catch <, > before deciding whether this word is
5693 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5696 redir_fd = redirect_opt_num(&dest);
5697 if (done_word(&dest, &ctx)) {
5700 redir_style = REDIRECT_OVERWRITE;
5702 redir_style = REDIRECT_APPEND;
5703 ch = i_getch(input);
5704 nommu_addchr(&ctx.as_string, ch);
5707 else if (next == '(') {
5708 syntax_error(">(process) not supported");
5712 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5714 continue; /* back to top of while (1) */
5716 redir_fd = redirect_opt_num(&dest);
5717 if (done_word(&dest, &ctx)) {
5720 redir_style = REDIRECT_INPUT;
5722 redir_style = REDIRECT_HEREDOC;
5724 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5725 ch = i_getch(input);
5726 nommu_addchr(&ctx.as_string, ch);
5727 } else if (next == '>') {
5728 redir_style = REDIRECT_IO;
5729 ch = i_getch(input);
5730 nommu_addchr(&ctx.as_string, ch);
5733 else if (next == '(') {
5734 syntax_error("<(process) not supported");
5738 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5740 continue; /* back to top of while (1) */
5743 if (dest.o_assignment == MAYBE_ASSIGNMENT
5744 /* check that we are not in word in "a=1 2>word b=1": */
5745 && !ctx.pending_redirect
5747 /* ch is a special char and thus this word
5748 * cannot be an assignment */
5749 dest.o_assignment = NOT_ASSIGNMENT;
5754 if (dest.length == 0) {
5757 if (ch == EOF || ch == '\n')
5760 /* note: we do not add it to &ctx.as_string */
5762 nommu_addchr(&ctx.as_string, '\n');
5764 o_addQchr(&dest, ch);
5769 syntax_error("\\<eof>");
5772 ch = i_getch(input);
5774 o_addchr(&dest, '\\');
5775 nommu_addchr(&ctx.as_string, '\\');
5776 o_addchr(&dest, ch);
5777 nommu_addchr(&ctx.as_string, ch);
5778 /* Example: echo Hello \2>file
5779 * we need to know that word 2 is quoted */
5784 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5785 debug_printf_parse("parse_stream parse error: "
5786 "handle_dollar returned non-0\n");
5793 ch = i_getch(input);
5795 syntax_error_unterm_ch('\'');
5796 /*xfunc_die(); - redundant */
5798 nommu_addchr(&ctx.as_string, ch);
5801 if (dest.o_assignment == NOT_ASSIGNMENT)
5802 o_addqchr(&dest, ch);
5804 o_addchr(&dest, ch);
5809 is_in_dquote ^= 1; /* invert */
5810 if (dest.o_assignment == NOT_ASSIGNMENT)
5813 #if ENABLE_HUSH_TICK
5818 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5819 o_addchr(&dest, '`');
5823 add_till_backquote(&dest, input);
5825 o_addstr(&ctx.as_string, dest.data + pos);
5826 o_addchr(&ctx.as_string, '`');
5828 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5829 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5834 #if ENABLE_HUSH_CASE
5837 if (done_word(&dest, &ctx)) {
5840 done_pipe(&ctx, PIPE_SEQ);
5841 #if ENABLE_HUSH_CASE
5842 /* Eat multiple semicolons, detect
5843 * whether it means something special */
5848 ch = i_getch(input);
5849 nommu_addchr(&ctx.as_string, ch);
5850 if (ctx.ctx_res_w == RES_CASE_BODY) {
5851 ctx.ctx_dsemicolon = 1;
5852 ctx.ctx_res_w = RES_MATCH;
5858 /* We just finished a cmd. New one may start
5859 * with an assignment */
5860 dest.o_assignment = MAYBE_ASSIGNMENT;
5863 if (done_word(&dest, &ctx)) {
5867 ch = i_getch(input);
5868 nommu_addchr(&ctx.as_string, ch);
5869 done_pipe(&ctx, PIPE_AND);
5871 done_pipe(&ctx, PIPE_BG);
5875 if (done_word(&dest, &ctx)) {
5878 #if ENABLE_HUSH_CASE
5879 if (ctx.ctx_res_w == RES_MATCH)
5880 break; /* we are in case's "word | word)" */
5882 if (next == '|') { /* || */
5883 ch = i_getch(input);
5884 nommu_addchr(&ctx.as_string, ch);
5885 done_pipe(&ctx, PIPE_OR);
5887 /* we could pick up a file descriptor choice here
5888 * with redirect_opt_num(), but bash doesn't do it.
5889 * "echo foo 2| cat" yields "foo 2". */
5894 #if ENABLE_HUSH_CASE
5895 /* "case... in [(]word)..." - skip '(' */
5896 if (ctx.ctx_res_w == RES_MATCH
5897 && ctx.command->argv == NULL /* not (word|(... */
5898 && dest.length == 0 /* not word(... */
5899 && dest.o_quoted == 0 /* not ""(... */
5905 if (parse_group(&dest, &ctx, input, ch) != 0) {
5910 #if ENABLE_HUSH_CASE
5911 if (ctx.ctx_res_w == RES_MATCH)
5915 /* proper use of this character is caught by end_trigger:
5916 * if we see {, we call parse_group(..., end_trigger='}')
5917 * and it will match } earlier (not here). */
5918 syntax_error_unexpected_ch(ch);
5922 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5928 struct parse_context *pctx;
5929 IF_HAS_KEYWORDS(struct parse_context *p2;)
5931 /* Clean up allocated tree.
5932 * Samples for finding leaks on syntax error recovery path.
5933 * Run them from interactive shell, watch pmap `pidof hush`.
5934 * while if false; then false; fi do break; done
5936 * while if false; then false; fi; do break; fi
5937 * Samples to catch leaks at execution:
5938 * while if (true | {true;}); then echo ok; fi; do break; done
5939 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5943 /* Update pipe/command counts,
5944 * otherwise freeing may miss some */
5945 done_pipe(pctx, PIPE_SEQ);
5946 debug_printf_clean("freeing list %p from ctx %p\n",
5947 pctx->list_head, pctx);
5948 debug_print_tree(pctx->list_head, 0);
5949 free_pipe_list(pctx->list_head);
5950 debug_printf_clean("freed list %p\n", pctx->list_head);
5952 o_free_unsafe(&pctx->as_string);
5954 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5958 IF_HAS_KEYWORDS(pctx = p2;)
5959 } while (HAS_KEYWORDS && pctx);
5960 /* Free text, clear all dest fields */
5962 /* If we are not in top-level parse, we return,
5963 * our caller will propagate error.
5965 if (end_trigger != ';') {
5973 /* Discard cached input, force prompt */
5975 IF_HUSH_INTERACTIVE(input->promptme = 1;)
5980 /* Executing from string: eval, sh -c '...'
5981 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5982 * end_trigger controls how often we stop parsing
5983 * NUL: parse all, execute, return
5984 * ';': parse till ';' or newline, execute, repeat till EOF
5986 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5989 struct pipe *pipe_list;
5991 pipe_list = parse_stream(NULL, inp, end_trigger);
5992 if (!pipe_list) /* EOF */
5994 debug_print_tree(pipe_list, 0);
5995 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5996 run_and_free_list(pipe_list);
6000 static void parse_and_run_string(const char *s)
6002 struct in_str input;
6003 setup_string_in_str(&input, s);
6004 parse_and_run_stream(&input, '\0');
6007 static void parse_and_run_file(FILE *f)
6009 struct in_str input;
6010 setup_file_in_str(&input, f);
6011 parse_and_run_stream(&input, ';');
6014 /* Called a few times only (or even once if "sh -c") */
6015 static void block_signals(int second_time)
6020 mask = (1 << SIGQUIT);
6021 if (G_interactive_fd) {
6022 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6023 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6024 mask |= SPECIAL_JOB_SIGS;
6026 G.non_DFL_mask = mask;
6029 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6033 sigaddset(&G.blocked_set, sig);
6037 sigdelset(&G.blocked_set, SIGCHLD);
6039 sigprocmask(SIG_SETMASK, &G.blocked_set,
6040 second_time ? NULL : &G.inherited_set);
6041 /* POSIX allows shell to re-enable SIGCHLD
6042 * even if it was SIG_IGN on entry */
6043 #if ENABLE_HUSH_FAST
6044 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6046 signal(SIGCHLD, SIGCHLD_handler);
6049 signal(SIGCHLD, SIG_DFL);
6055 static void maybe_set_to_sigexit(int sig)
6057 void (*handler)(int);
6058 /* non_DFL_mask'ed signals are, well, masked,
6059 * no need to set handler for them.
6061 if (!((G.non_DFL_mask >> sig) & 1)) {
6062 handler = signal(sig, sigexit);
6063 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6064 signal(sig, handler);
6067 /* Set handlers to restore tty pgrp and exit */
6068 static void set_fatal_handlers(void)
6070 /* We _must_ restore tty pgrp on fatal signals */
6072 maybe_set_to_sigexit(SIGILL );
6073 maybe_set_to_sigexit(SIGFPE );
6074 maybe_set_to_sigexit(SIGBUS );
6075 maybe_set_to_sigexit(SIGSEGV);
6076 maybe_set_to_sigexit(SIGTRAP);
6077 } /* else: hush is perfect. what SEGV? */
6078 maybe_set_to_sigexit(SIGABRT);
6079 /* bash 3.2 seems to handle these just like 'fatal' ones */
6080 maybe_set_to_sigexit(SIGPIPE);
6081 maybe_set_to_sigexit(SIGALRM);
6082 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6083 * if we aren't interactive... but in this case
6084 * we never want to restore pgrp on exit, and this fn is not called */
6085 /*maybe_set_to_sigexit(SIGHUP );*/
6086 /*maybe_set_to_sigexit(SIGTERM);*/
6087 /*maybe_set_to_sigexit(SIGINT );*/
6091 static int set_mode(const char cstate, const char mode)
6093 int state = (cstate == '-' ? 1 : 0);
6095 case 'n': G.fake_mode = state; break;
6096 case 'x': /*G.debug_mode = state;*/ break;
6097 default: return EXIT_FAILURE;
6099 return EXIT_SUCCESS;
6102 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6103 int hush_main(int argc, char **argv)
6105 static const struct variable const_shell_ver = {
6107 .varstr = (char*)hush_version_str,
6108 .max_len = 1, /* 0 can provoke free(name) */
6112 int signal_mask_is_inited = 0;
6115 struct variable *cur_var;
6118 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6119 G.last_exitcode = EXIT_SUCCESS;
6121 G.argv0_for_re_execing = argv[0];
6123 /* Deal with HUSH_VERSION */
6124 G.shell_ver = const_shell_ver; /* copying struct here */
6125 G.top_var = &G.shell_ver;
6126 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6127 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6128 /* Initialize our shell local variables with the values
6129 * currently living in the environment */
6130 cur_var = G.top_var;
6133 char *value = strchr(*e, '=');
6134 if (value) { /* paranoia */
6135 cur_var->next = xzalloc(sizeof(*cur_var));
6136 cur_var = cur_var->next;
6137 cur_var->varstr = *e;
6138 cur_var->max_len = strlen(*e);
6139 cur_var->flg_export = 1;
6143 debug_printf_env("putenv '%s'\n", hush_version_str);
6144 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
6145 #if ENABLE_FEATURE_EDITING
6146 G.line_input_state = new_line_input_t(FOR_SHELL);
6148 G.global_argc = argc;
6149 G.global_argv = argv;
6150 /* Initialize some more globals to non-zero values */
6152 cmdedit_update_prompt();
6154 if (setjmp(die_jmp)) {
6155 /* xfunc has failed! die die die */
6156 /* no EXIT traps, this is an escape hatch! */
6158 hush_exit(xfunc_error_retval);
6161 /* Shell is non-interactive at first. We need to call
6162 * block_signals(0) if we are going to execute "sh <script>",
6163 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6164 * If we later decide that we are interactive, we run block_signals(0)
6165 * (or re-run block_signals(1) if we ran block_signals(0) before)
6166 * in order to intercept (more) signals.
6170 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6172 opt = getopt(argc, argv, "c:xins"
6175 # if ENABLE_HUSH_FUNCTIONS
6185 G.root_pid = getpid();
6186 G.global_argv = argv + optind;
6187 if (!argv[optind]) {
6188 /* -c 'script' (no params): prevent empty $0 */
6189 *--G.global_argv = argv[0];
6191 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
6192 G.global_argc = argc - optind;
6193 block_signals(0); /* 0: called 1st time */
6194 parse_and_run_string(optarg);
6197 /* Well, we cannot just declare interactiveness,
6198 * we have to have some stuff (ctty, etc) */
6199 /* G_interactive_fd++; */
6202 /* "-s" means "read from stdin", but this is how we always
6203 * operate, so simply do nothing here. */
6206 case '<': /* "big heredoc" support */
6207 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6210 G.root_pid = bb_strtou(optarg, &optarg, 16);
6212 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6214 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6215 # if ENABLE_HUSH_LOOPS
6217 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6222 set_local_var(xstrdup(optarg), 0, opt == 'R');
6224 # if ENABLE_HUSH_FUNCTIONS
6226 struct function *funcp = new_function(optarg);
6227 /* funcp->name is already set to optarg */
6228 /* funcp->body is set to NULL. It's a special case. */
6229 funcp->body_as_string = argv[optind];
6237 if (!set_mode('-', opt))
6241 fprintf(stderr, "Usage: sh [FILE]...\n"
6242 " or: sh -c command [args]...\n\n");
6248 } /* option parsing loop */
6251 G.root_pid = getpid();
6253 /* If we are login shell... */
6254 if (argv[0] && argv[0][0] == '-') {
6256 debug_printf("sourcing /etc/profile\n");
6257 input = fopen_for_read("/etc/profile");
6258 if (input != NULL) {
6259 close_on_exec_on(fileno(input));
6260 block_signals(0); /* 0: called 1st time */
6261 signal_mask_is_inited = 1;
6262 parse_and_run_file(input);
6265 /* bash: after sourcing /etc/profile,
6266 * tries to source (in the given order):
6267 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6268 * stopping of first found. --noprofile turns this off.
6269 * bash also sources ~/.bash_logout on exit.
6270 * If called as sh, skips .bash_XXX files.
6277 * "bash <script>" (which is never interactive (unless -i?))
6278 * sources $BASH_ENV here (without scanning $PATH).
6279 * If called as sh, does the same but with $ENV.
6281 debug_printf("running script '%s'\n", argv[optind]);
6282 G.global_argv = argv + optind;
6283 G.global_argc = argc - optind;
6284 input = xfopen_for_read(argv[optind]);
6285 close_on_exec_on(fileno(input));
6286 if (!signal_mask_is_inited)
6287 block_signals(0); /* 0: called 1st time */
6288 parse_and_run_file(input);
6289 #if ENABLE_FEATURE_CLEAN_UP
6295 /* Up to here, shell was non-interactive. Now it may become one.
6296 * NB: don't forget to (re)run block_signals(0/1) as needed.
6299 /* A shell is interactive if the '-i' flag was given, or if all of
6300 * the following conditions are met:
6302 * no arguments remaining or the -s flag given
6303 * standard input is a terminal
6304 * standard output is a terminal
6305 * Refer to Posix.2, the description of the 'sh' utility.
6308 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6309 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6310 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
6311 if (G_saved_tty_pgrp < 0)
6312 G_saved_tty_pgrp = 0;
6314 /* try to dup stdin to high fd#, >= 255 */
6315 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6316 if (G_interactive_fd < 0) {
6317 /* try to dup to any fd */
6318 G_interactive_fd = dup(STDIN_FILENO);
6319 if (G_interactive_fd < 0) {
6321 G_interactive_fd = 0;
6322 G_saved_tty_pgrp = 0;
6325 // TODO: track & disallow any attempts of user
6326 // to (inadvertently) close/redirect G_interactive_fd
6328 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6329 if (G_interactive_fd) {
6330 close_on_exec_on(G_interactive_fd);
6332 if (G_saved_tty_pgrp) {
6333 /* If we were run as 'hush &', sleep until we are
6334 * in the foreground (tty pgrp == our pgrp).
6335 * If we get started under a job aware app (like bash),
6336 * make sure we are now in charge so we don't fight over
6337 * who gets the foreground */
6339 pid_t shell_pgrp = getpgrp();
6340 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6341 if (G_saved_tty_pgrp == shell_pgrp)
6343 /* send TTIN to ourself (should stop us) */
6344 kill(- shell_pgrp, SIGTTIN);
6348 /* Block some signals */
6349 block_signals(signal_mask_is_inited);
6351 if (G_saved_tty_pgrp) {
6352 /* Set other signals to restore saved_tty_pgrp */
6353 set_fatal_handlers();
6354 /* Put ourselves in our own process group
6355 * (bash, too, does this only if ctty is available) */
6356 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6357 /* Grab control of the terminal */
6358 tcsetpgrp(G_interactive_fd, getpid());
6360 /* -1 is special - makes xfuncs longjmp, not exit
6361 * (we reset die_sleep = 0 whereever we [v]fork) */
6362 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6363 } else if (!signal_mask_is_inited) {
6364 block_signals(0); /* 0: called 1st time */
6365 } /* else: block_signals(0) was done before */
6366 #elif ENABLE_HUSH_INTERACTIVE
6367 /* No job control compiled in, only prompt/line editing */
6368 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6369 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6370 if (G_interactive_fd < 0) {
6371 /* try to dup to any fd */
6372 G_interactive_fd = dup(STDIN_FILENO);
6373 if (G_interactive_fd < 0)
6375 G_interactive_fd = 0;
6378 if (G_interactive_fd) {
6379 close_on_exec_on(G_interactive_fd);
6380 block_signals(signal_mask_is_inited);
6381 } else if (!signal_mask_is_inited) {
6385 /* We have interactiveness code disabled */
6386 if (!signal_mask_is_inited) {
6391 * if interactive but not a login shell, sources ~/.bashrc
6392 * (--norc turns this off, --rcfile <file> overrides)
6395 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6396 printf("\n\n%s hush - the humble shell\n", bb_banner);
6397 if (ENABLE_HUSH_HELP)
6398 puts("Enter 'help' for a list of built-in commands.");
6402 parse_and_run_file(stdin);
6405 #if ENABLE_FEATURE_CLEAN_UP
6406 if (G.cwd != bb_msg_unknown)
6408 cur_var = G.top_var->next;
6410 struct variable *tmp = cur_var;
6411 if (!cur_var->max_len)
6412 free(cur_var->varstr);
6413 cur_var = cur_var->next;
6417 hush_exit(G.last_exitcode);
6422 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6423 int lash_main(int argc, char **argv)
6425 //bb_error_msg("lash is deprecated, please use hush instead");
6426 return hush_main(argc, argv);
6434 static int builtin_true(char **argv UNUSED_PARAM)
6439 static int builtin_test(char **argv)
6446 return test_main(argc, argv - argc);
6449 static int builtin_echo(char **argv)
6456 return echo_main(argc, argv - argc);
6459 static int builtin_eval(char **argv)
6461 int rcode = EXIT_SUCCESS;
6464 char *str = expand_strvec_to_string(argv);
6466 * eval "echo Hi; done" ("done" is syntax error):
6467 * "echo Hi" will not execute too.
6469 parse_and_run_string(str);
6471 rcode = G.last_exitcode;
6476 static int builtin_cd(char **argv)
6478 const char *newdir = argv[1];
6479 if (newdir == NULL) {
6480 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6481 * bash says "bash: cd: HOME not set" and does nothing
6484 newdir = get_local_var_value("HOME") ? : "/";
6486 if (chdir(newdir)) {
6487 /* Mimic bash message exactly */
6488 bb_perror_msg("cd: %s", newdir);
6489 return EXIT_FAILURE;
6492 return EXIT_SUCCESS;
6495 static int builtin_exec(char **argv)
6497 if (*++argv == NULL)
6498 return EXIT_SUCCESS; /* bash does this */
6503 /* TODO: if exec fails, bash does NOT exit! We do... */
6504 pseudo_exec_argv(&dummy, argv, 0, NULL);
6509 static int builtin_exit(char **argv)
6511 debug_printf_exec("%s()\n", __func__);
6513 /* interactive bash:
6514 * # trap "echo EEE" EXIT
6517 * There are stopped jobs.
6518 * (if there are _stopped_ jobs, running ones don't count)
6521 # EEE (then bash exits)
6523 * we can use G.exiting = -1 as indicator "last cmd was exit"
6526 /* note: EXIT trap is run by hush_exit */
6527 if (*++argv == NULL)
6528 hush_exit(G.last_exitcode);
6529 /* mimic bash: exit 123abc == exit 255 + error msg */
6530 xfunc_error_retval = 255;
6531 /* bash: exit -2 == exit 254, no error msg */
6532 hush_exit(xatoi(*argv) & 0xff);
6535 static void print_escaped(const char *s)
6541 p = strchrnul(s, '\'');
6542 /* print 'xxxx', possibly just '' */
6543 printf("'%.*s'", (int)(p - s), s);
6548 /* s points to '; print "'''...'''" */
6550 do putchar('\''); while (*++s == '\'');
6555 static int builtin_export(char **argv)
6557 unsigned opt_unexport;
6559 if (argv[1] == NULL) {
6566 /* ash emits: export VAR='VAL'
6567 * bash: declare -x VAR="VAL"
6568 * we follow ash example */
6569 const char *s = *e++;
6570 const char *p = strchr(s, '=');
6572 if (!p) /* wtf? take next variable */
6575 printf("export %.*s", (int)(p - s) + 1, s);
6576 print_escaped(p + 1);
6580 /*fflush(stdout); - done after each builtin anyway */
6582 return EXIT_SUCCESS;
6585 #if ENABLE_HUSH_EXPORT_N
6586 /* "!": do not abort on errors */
6587 /* "+": stop at 1st non-option */
6588 opt_unexport = getopt32(argv, "!+n");
6589 if (opt_unexport == (unsigned)-1)
6590 return EXIT_FAILURE;
6600 /* So far we do not check that name is valid (TODO?) */
6602 if (strchr(name, '=') == NULL) {
6603 struct variable *var;
6605 var = get_local_var(name);
6607 /* export -n NAME (without =VALUE) */
6609 var->flg_export = 0;
6610 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
6612 } /* else: export -n NOT_EXISTING_VAR: no-op */
6615 /* export NAME (without =VALUE) */
6617 var->flg_export = 1;
6618 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6619 putenv(var->varstr);
6622 /* Exporting non-existing variable.
6623 * bash does not put it in environment,
6624 * but remembers that it is exported,
6625 * and does put it in env when it is set later.
6626 * We just set it to "" and export. */
6627 name = xasprintf("%s=", name);
6629 /* (Un)exporting NAME=VALUE */
6630 name = xstrdup(name);
6633 /*export:*/ (opt_unexport ? -1 : 1),
6638 return EXIT_SUCCESS;
6641 static int builtin_trap(char **argv)
6647 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6652 /* No args: print all trapped */
6653 for (i = 0; i < NSIG; ++i) {
6656 print_escaped(G.traps[i]);
6657 printf(" %s\n", get_signame(i));
6660 /*fflush(stdout); - done after each builtin anyway */
6661 return EXIT_SUCCESS;
6665 /* If first arg is a number: reset all specified signals */
6666 sig = bb_strtou(*argv, NULL, 10);
6672 sig = get_signum(*argv++);
6673 if (sig < 0 || sig >= NSIG) {
6675 /* Mimic bash message exactly */
6676 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
6681 G.traps[sig] = xstrdup(new_cmd);
6683 debug_printf("trap: setting SIG%s (%i) to '%s'",
6684 get_signame(sig), sig, G.traps[sig]);
6686 /* There is no signal for 0 (EXIT) */
6691 sigaddset(&G.blocked_set, sig);
6693 /* There was a trap handler, we are removing it
6694 * (if sig has non-DFL handling,
6695 * we don't need to do anything) */
6696 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6698 sigdelset(&G.blocked_set, sig);
6701 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6705 if (!argv[1]) { /* no second arg */
6706 bb_error_msg("trap: invalid arguments");
6707 return EXIT_FAILURE;
6710 /* First arg is "-": reset all specified to default */
6711 /* First arg is "--": skip it, the rest is "handler SIGs..." */
6712 /* Everything else: set arg as signal handler
6713 * (includes "" case, which ignores signal) */
6714 if (argv[0][0] == '-') {
6715 if (argv[0][1] == '\0') { /* "-" */
6716 /* new_cmd remains NULL: "reset these sigs" */
6719 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
6722 /* else: "-something", no special meaning */
6727 goto process_sig_list;
6731 /* built-in 'fg' and 'bg' handler */
6732 static int builtin_fg_bg(char **argv)
6737 if (!G_interactive_fd)
6738 return EXIT_FAILURE;
6740 /* If they gave us no args, assume they want the last backgrounded task */
6742 for (pi = G.job_list; pi; pi = pi->next) {
6743 if (pi->jobid == G.last_jobid) {
6747 bb_error_msg("%s: no current job", argv[0]);
6748 return EXIT_FAILURE;
6750 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6751 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6752 return EXIT_FAILURE;
6754 for (pi = G.job_list; pi; pi = pi->next) {
6755 if (pi->jobid == jobnum) {
6759 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6760 return EXIT_FAILURE;
6762 /* TODO: bash prints a string representation
6763 * of job being foregrounded (like "sleep 1 | cat") */
6764 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
6765 /* Put the job into the foreground. */
6766 tcsetpgrp(G_interactive_fd, pi->pgrp);
6769 /* Restart the processes in the job */
6770 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6771 for (i = 0; i < pi->num_cmds; i++) {
6772 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6773 pi->cmds[i].is_stopped = 0;
6775 pi->stopped_cmds = 0;
6777 i = kill(- pi->pgrp, SIGCONT);
6779 if (errno == ESRCH) {
6780 delete_finished_bg_job(pi);
6781 return EXIT_SUCCESS;
6783 bb_perror_msg("kill (SIGCONT)");
6786 if (argv[0][0] == 'f') {
6788 return checkjobs_and_fg_shell(pi);
6790 return EXIT_SUCCESS;
6794 #if ENABLE_HUSH_HELP
6795 static int builtin_help(char **argv UNUSED_PARAM)
6797 const struct built_in_command *x;
6800 "Built-in commands:\n"
6801 "------------------\n");
6802 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6803 printf("%s\t%s\n", x->cmd, x->descr);
6806 return EXIT_SUCCESS;
6811 static int builtin_jobs(char **argv UNUSED_PARAM)
6814 const char *status_string;
6816 for (job = G.job_list; job; job = job->next) {
6817 if (job->alive_cmds == job->stopped_cmds)
6818 status_string = "Stopped";
6820 status_string = "Running";
6822 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6824 return EXIT_SUCCESS;
6829 static int builtin_memleak(char **argv UNUSED_PARAM)
6834 /* Crude attempt to find where "free memory" starts,
6835 * sans fragmentation. */
6837 l = (unsigned long)p;
6840 if (l < (unsigned long)p) l = (unsigned long)p;
6843 if (!G.memleak_value)
6844 G.memleak_value = l;
6846 l -= G.memleak_value;
6853 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6858 static int builtin_pwd(char **argv UNUSED_PARAM)
6861 return EXIT_SUCCESS;
6864 static int builtin_read(char **argv)
6867 const char *name = "REPLY";
6871 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6872 * and _after_ that_ it will complain */
6873 if (!is_well_formed_var_name(name, '\0')) {
6874 /* Mimic bash message */
6875 bb_error_msg("read: '%s': not a valid identifier", name);
6880 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6882 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6883 return set_local_var(string, 0, 0);
6886 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6887 * built-in 'set' handler
6889 * set [-abCefhmnuvx] [-o option] [argument...]
6890 * set [+abCefhmnuvx] [+o option] [argument...]
6891 * set -- [argument...]
6894 * Implementations shall support the options in both their hyphen and
6895 * plus-sign forms. These options can also be specified as options to sh.
6897 * Write out all variables and their values: set
6898 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6899 * Turn on the -x and -v options: set -xv
6900 * Unset all positional parameters: set --
6901 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6902 * Set the positional parameters to the expansion of x, even if x expands
6903 * with a leading '-' or '+': set -- $x
6905 * So far, we only support "set -- [argument...]" and some of the short names.
6907 static int builtin_set(char **argv)
6910 char **pp, **g_argv;
6911 char *arg = *++argv;
6915 for (e = G.top_var; e; e = e->next)
6917 return EXIT_SUCCESS;
6921 if (!strcmp(arg, "--")) {
6925 if (arg[0] != '+' && arg[0] != '-')
6927 for (n = 1; arg[n]; ++n)
6928 if (set_mode(arg[0], arg[n]))
6930 } while ((arg = *++argv) != NULL);
6931 /* Now argv[0] is 1st argument */
6934 return EXIT_SUCCESS;
6937 /* NB: G.global_argv[0] ($0) is never freed/changed */
6938 g_argv = G.global_argv;
6939 if (G.global_args_malloced) {
6945 G.global_args_malloced = 1;
6946 pp = xzalloc(sizeof(pp[0]) * 2);
6947 pp[0] = g_argv[0]; /* retain $0 */
6950 /* This realloc's G.global_argv */
6951 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6958 return EXIT_SUCCESS;
6960 /* Nothing known, so abort */
6962 bb_error_msg("set: %s: invalid option", arg);
6963 return EXIT_FAILURE;
6966 static int builtin_shift(char **argv)
6972 if (n >= 0 && n < G.global_argc) {
6973 if (G.global_args_malloced) {
6976 free(G.global_argv[m++]);
6979 memmove(&G.global_argv[1], &G.global_argv[n+1],
6980 G.global_argc * sizeof(G.global_argv[0]));
6981 return EXIT_SUCCESS;
6983 return EXIT_FAILURE;
6986 static int builtin_source(char **argv)
6991 #if ENABLE_HUSH_FUNCTIONS
6995 if (*++argv == NULL)
6996 return EXIT_FAILURE;
6998 if (strchr(*argv, '/') == NULL
6999 && (PATH = get_local_var_value("PATH")) != NULL
7001 /* Search through $PATH */
7003 const char *end = strchrnul(PATH, ':');
7004 int sz = end - PATH; /* must be int! */
7007 char *tmp = xasprintf("%.*s/%s", sz, PATH, *argv);
7008 input = fopen_for_read(tmp);
7011 /* We have xxx::yyyy in $PATH,
7012 * it means "use current dir" */
7013 input = fopen_for_read(*argv);
7022 input = fopen_or_warn(*argv, "r");
7024 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7025 return EXIT_FAILURE;
7028 close_on_exec_on(fileno(input));
7030 #if ENABLE_HUSH_FUNCTIONS
7031 sv_flg = G.flag_return_in_progress;
7032 /* "we are inside sourced file, ok to use return" */
7033 G.flag_return_in_progress = -1;
7035 save_and_replace_G_args(&sv, argv);
7037 parse_and_run_file(input);
7040 restore_G_args(&sv, argv);
7041 #if ENABLE_HUSH_FUNCTIONS
7042 G.flag_return_in_progress = sv_flg;
7045 return G.last_exitcode;
7048 static int builtin_umask(char **argv)
7055 mode_t old_mask = mask;
7058 rc = bb_parse_mode(argv[1], &mask);
7063 * bash: umask: 'q': invalid symbolic mode operator
7064 * bash: umask: 999: octal number out of range
7066 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7071 printf("%04o\n", (unsigned) mask);
7072 /* fall through and restore mask which we set to 0 */
7076 return !rc; /* rc != 0 - success */
7079 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7080 static int builtin_unset(char **argv)
7085 /* "!": do not abort on errors */
7086 /* "+": stop at 1st non-option */
7087 opts = getopt32(argv, "!+vf");
7088 if (opts == (unsigned)-1)
7089 return EXIT_FAILURE;
7091 bb_error_msg("unset: -v and -f are exclusive");
7092 return EXIT_FAILURE;
7098 if (!(opts & 2)) { /* not -f */
7099 if (unset_local_var(*argv)) {
7100 /* unset <nonexistent_var> doesn't fail.
7101 * Error is when one tries to unset RO var.
7102 * Message was printed by unset_local_var. */
7106 #if ENABLE_HUSH_FUNCTIONS
7116 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7117 static int builtin_wait(char **argv)
7119 int ret = EXIT_SUCCESS;
7122 if (*++argv == NULL) {
7123 /* Don't care about wait results */
7124 /* Note 1: must wait until there are no more children */
7125 /* Note 2: must be interruptible */
7127 * $ sleep 3 & sleep 6 & wait
7132 * $ sleep 3 & sleep 6 & wait
7136 * ^C <-- after ~4 sec from keyboard
7139 sigaddset(&G.blocked_set, SIGCHLD);
7140 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7143 if (errno == ECHILD)
7145 /* Wait for SIGCHLD or any other signal of interest */
7146 /* sigtimedwait with infinite timeout: */
7147 sig = sigwaitinfo(&G.blocked_set, NULL);
7149 sig = check_and_run_traps(sig);
7150 if (sig && sig != SIGCHLD) { /* see note 2 */
7156 sigdelset(&G.blocked_set, SIGCHLD);
7157 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7161 /* This is probably buggy wrt interruptible-ness */
7163 pid_t pid = bb_strtou(*argv, NULL, 10);
7165 /* mimic bash message */
7166 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
7167 return EXIT_FAILURE;
7169 if (waitpid(pid, &status, 0) == pid) {
7170 if (WIFSIGNALED(status))
7171 ret = 128 + WTERMSIG(status);
7172 else if (WIFEXITED(status))
7173 ret = WEXITSTATUS(status);
7177 bb_perror_msg("wait %s", *argv);
7186 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
7187 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
7190 def = bb_strtou(argv[1], NULL, 10);
7191 if (errno || def < def_min || argv[2]) {
7192 bb_error_msg("%s: bad arguments", argv[0]);
7200 #if ENABLE_HUSH_LOOPS
7201 static int builtin_break(char **argv)
7204 if (G.depth_of_loop == 0) {
7205 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7206 return EXIT_SUCCESS; /* bash compat */
7208 G.flag_break_continue++; /* BC_BREAK = 1 */
7210 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
7211 if (depth == UINT_MAX)
7212 G.flag_break_continue = BC_BREAK;
7213 if (G.depth_of_loop < depth)
7214 G.depth_break_continue = G.depth_of_loop;
7216 return EXIT_SUCCESS;
7219 static int builtin_continue(char **argv)
7221 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
7222 return builtin_break(argv);
7226 #if ENABLE_HUSH_FUNCTIONS
7227 static int builtin_return(char **argv)
7231 if (G.flag_return_in_progress != -1) {
7232 bb_error_msg("%s: not in a function or sourced script", argv[0]);
7233 return EXIT_FAILURE; /* bash compat */
7236 G.flag_return_in_progress = 1;
7239 * out of range: wraps around at 256, does not error out
7240 * non-numeric param:
7241 * f() { false; return qwe; }; f; echo $?
7242 * bash: return: qwe: numeric argument required <== we do this
7243 * 255 <== we also do this
7245 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);