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.
41 * grep for "TODO" and fix (some of them are easy)
42 * special variables (done: PWD, PPID, RANDOM)
45 * follow IFS rules more precisely, including update semantics
46 * builtins mandated by standards we don't support:
47 * [un]alias, command, fc, getopts, newgrp, readonly, times
48 * make complex ${var%...} constructs support optional
49 * make here documents optional
52 * redirection of stdout+stderr: &> and >&
53 * subst operator: ${var/[/]expr/expr}
54 * brace expansion: one/{two,three,four}
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
67 * export builtin should be special, its arguments are assignments
68 * and therefore expansion of them should be "one-word" expansion:
69 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
71 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
72 * ls: cannot access i=a: No such file or directory
73 * ls: cannot access b: No such file or directory
74 * Note1: same applies to local builtin.
75 * Note2: bash 3.2.33(1) does this only if export word itself
77 * $ export i=`echo 'aaa bbb'`; echo "$i"
79 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
82 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
84 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
85 #include <malloc.h> /* for malloc_trim */
87 /* #include <dmalloc.h> */
92 #include "shell_common.h"
95 #if ENABLE_HUSH_RANDOM_SUPPORT
98 # define CLEAR_RANDOM_T(rnd) ((void)0)
101 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
106 #define LEAK_HUNTING 0
107 #define BUILD_AS_NOMMU 0
108 /* Enable/disable sanity checks. Ok to enable in production,
109 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
110 * Keeping 1 for now even in released versions.
113 /* Slightly bigger (+200 bytes), but faster hush.
114 * So far it only enables a trick with counting SIGCHLDs and forks,
115 * which allows us to do fewer waitpid's.
116 * (we can detect a case where neither forks were done nor SIGCHLDs happened
117 * and therefore waitpid will return the same result as last time)
119 #define ENABLE_HUSH_FAST 0
124 # undef USE_FOR_NOMMU
127 # define USE_FOR_NOMMU(...) __VA_ARGS__
128 # define USE_FOR_MMU(...)
131 #define SKIP_definitions 1
132 #include "applet_tables.h"
133 #undef SKIP_definitions
135 /* STANDALONE does not make sense, and won't compile */
136 # undef CONFIG_FEATURE_SH_STANDALONE
137 # undef ENABLE_FEATURE_SH_STANDALONE
138 # undef IF_FEATURE_SH_STANDALONE
139 # undef IF_NOT_FEATURE_SH_STANDALONE
140 # define ENABLE_FEATURE_SH_STANDALONE 0
141 # define IF_FEATURE_SH_STANDALONE(...)
142 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
145 #if !ENABLE_HUSH_INTERACTIVE
146 # undef ENABLE_FEATURE_EDITING
147 # define ENABLE_FEATURE_EDITING 0
148 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
149 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
152 /* Do we support ANY keywords? */
153 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
154 # define HAS_KEYWORDS 1
155 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
156 # define IF_HAS_NO_KEYWORDS(...)
158 # define HAS_KEYWORDS 0
159 # define IF_HAS_KEYWORDS(...)
160 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
163 /* If you comment out one of these below, it will be #defined later
164 * to perform debug printfs to stderr: */
165 #define debug_printf(...) do {} while (0)
166 /* Finer-grained debug switches */
167 #define debug_printf_parse(...) do {} while (0)
168 #define debug_print_tree(a, b) do {} while (0)
169 #define debug_printf_exec(...) do {} while (0)
170 #define debug_printf_env(...) do {} while (0)
171 #define debug_printf_jobs(...) do {} while (0)
172 #define debug_printf_expand(...) do {} while (0)
173 #define debug_printf_varexp(...) do {} while (0)
174 #define debug_printf_glob(...) do {} while (0)
175 #define debug_printf_list(...) do {} while (0)
176 #define debug_printf_subst(...) do {} while (0)
177 #define debug_printf_clean(...) do {} while (0)
179 #define ERR_PTR ((void*)(long)1)
181 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
183 #define _SPECIAL_VARS_STR "_*@$!?#"
184 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
185 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
187 #define SPECIAL_VAR_SYMBOL 3
191 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
193 /* This supports saving pointers malloced in vfork child,
194 * to be freed in the parent.
197 typedef struct nommu_save_t {
199 struct variable *old_vars;
201 char **argv_from_re_execing;
205 typedef enum reserved_style {
214 #if ENABLE_HUSH_LOOPS
221 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
226 /* three pseudo-keywords support contrived "case" syntax: */
227 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
228 RES_MATCH , /* "word)" */
229 RES_CASE_BODY, /* "this command is inside CASE" */
236 typedef struct o_string {
238 int length; /* position where data is appended */
240 /* Protect newly added chars against globbing
241 * (by prepending \ to *, ?, [, \) */
244 /* At least some part of the string was inside '' or "",
245 * possibly empty one: word"", wo''rd etc. */
247 smallint has_empty_slot;
248 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
251 MAYBE_ASSIGNMENT = 0,
252 DEFINITELY_ASSIGNMENT = 1,
254 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
256 /* Used for initialization: o_string foo = NULL_O_STRING; */
257 #define NULL_O_STRING { NULL }
259 /* I can almost use ordinary FILE*. Is open_memstream() universally
260 * available? Where is it documented? */
261 typedef struct in_str {
263 /* eof_flag=1: last char in ->p is really an EOF */
264 char eof_flag; /* meaningless if ->p == NULL */
266 #if ENABLE_HUSH_INTERACTIVE
268 smallint promptmode; /* 0: PS1, 1: PS2 */
271 int (*get) (struct in_str *) FAST_FUNC;
272 int (*peek) (struct in_str *) FAST_FUNC;
274 #define i_getch(input) ((input)->get(input))
275 #define i_peek(input) ((input)->peek(input))
277 /* The descrip member of this structure is only used to make
278 * debugging output pretty */
279 static const struct {
281 signed char default_fd;
284 { O_RDONLY, 0, "<" },
285 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
286 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
287 { O_CREAT|O_RDWR, 1, "<>" },
288 { O_RDONLY, 0, "<<" },
289 /* Should not be needed. Bogus default_fd helps in debugging */
290 /* { O_RDONLY, 77, "<<" }, */
293 struct redir_struct {
294 struct redir_struct *next;
295 char *rd_filename; /* filename */
296 int rd_fd; /* fd to redirect */
297 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
299 smallint rd_type; /* (enum redir_type) */
300 /* note: for heredocs, rd_filename contains heredoc delimiter,
301 * and subsequently heredoc itself; and rd_dup is a bitmask:
302 * bit 0: do we need to trim leading tabs?
303 * bit 1: is heredoc quoted (<<'delim' syntax) ?
306 typedef enum redir_type {
308 REDIRECT_OVERWRITE = 1,
311 REDIRECT_HEREDOC = 4,
312 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
315 REDIRFD_SYNTAX_ERR = -2,
316 REDIRFD_TO_FILE = -1,
317 /* otherwise, rd_fd is redirected to rd_dup */
319 HEREDOC_SKIPTABS = 1,
325 pid_t pid; /* 0 if exited */
326 int assignment_cnt; /* how many argv[i] are assignments? */
327 smallint is_stopped; /* is the command currently running? */
328 smallint cmd_type; /* CMD_xxx */
330 #define CMD_SUBSHELL 1
332 /* used for "[[ EXPR ]]" */
333 #if ENABLE_HUSH_BASH_COMPAT
334 # define CMD_SINGLEWORD_NOGLOB 2
337 /* used for "export noglob=* glob* a=`echo a b`" */
338 //#define CMD_SINGLEWORD_NOGLOB_COND 3
339 // It is hard to implement correctly, it adds significant amounts of tricky code,
340 // and all this is only useful for really obscure export statements
341 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
342 // guards the code which implements it, but I have doubts it works
343 // in all cases (especially with mixed globbed/non-globbed arguments)
345 #if ENABLE_HUSH_FUNCTIONS
346 # define CMD_FUNCDEF 3
349 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
352 char *group_as_string;
354 #if ENABLE_HUSH_FUNCTIONS
355 struct function *child_func;
356 /* This field is used to prevent a bug here:
357 * while...do f1() {a;}; f1; f1() {b;}; f1; done
358 * When we execute "f1() {a;}" cmd, we create new function and clear
359 * cmd->group, cmd->group_as_string, cmd->argv[0].
360 * When we execute "f1() {b;}", we notice that f1 exists,
361 * and that its "parent cmd" struct is still "alive",
362 * we put those fields back into cmd->xxx
363 * (struct function has ->parent_cmd ptr to facilitate that).
364 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
365 * Without this trick, loop would execute a;b;b;b;...
366 * instead of correct sequence a;b;a;b;...
367 * When command is freed, it severs the link
368 * (sets ->child_func->parent_cmd to NULL).
371 char **argv; /* command name and arguments */
372 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
373 * and on execution these are substituted with their values.
374 * Substitution can make _several_ words out of one argv[n]!
375 * Example: argv[0]=='.^C*^C.' here: echo .$*.
376 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
378 struct redir_struct *redirects; /* I/O redirections */
380 /* Is there anything in this command at all? */
381 #define IS_NULL_CMD(cmd) \
382 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
387 int num_cmds; /* total number of commands in pipe */
388 int alive_cmds; /* number of commands running (not exited) */
389 int stopped_cmds; /* number of commands alive, but stopped */
391 int jobid; /* job number */
392 pid_t pgrp; /* process group ID for the job */
393 char *cmdtext; /* name of job */
395 struct command *cmds; /* array of commands in pipe */
396 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
397 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
398 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
400 typedef enum pipe_style {
406 /* Is there anything in this pipe at all? */
407 #define IS_NULL_PIPE(pi) \
408 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
410 /* This holds pointers to the various results of parsing */
411 struct parse_context {
412 /* linked list of pipes */
413 struct pipe *list_head;
414 /* last pipe (being constructed right now) */
416 /* last command in pipe (being constructed right now) */
417 struct command *command;
418 /* last redirect in command->redirects list */
419 struct redir_struct *pending_redirect;
425 smallint ctx_inverted; /* "! cmd | cmd" */
427 smallint ctx_dsemicolon; /* ";;" seen */
429 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
431 /* group we are enclosed in:
432 * example: "if pipe1; pipe2; then pipe3; fi"
433 * when we see "if" or "then", we malloc and copy current context,
434 * and make ->stack point to it. then we parse pipeN.
435 * when closing "then" / fi" / whatever is found,
436 * we move list_head into ->stack->command->group,
437 * copy ->stack into current context, and delete ->stack.
438 * (parsing of { list } and ( list ) doesn't use this method)
440 struct parse_context *stack;
444 /* On program start, environ points to initial environment.
445 * putenv adds new pointers into it, unsetenv removes them.
446 * Neither of these (de)allocates the strings.
447 * setenv allocates new strings in malloc space and does putenv,
448 * and thus setenv is unusable (leaky) for shell's purposes */
449 #define setenv(...) setenv_is_leaky_dont_use()
451 struct variable *next;
452 char *varstr; /* points to "name=" portion */
453 #if ENABLE_HUSH_LOCAL
454 unsigned func_nest_level;
456 int max_len; /* if > 0, name is part of initial env; else name is malloced */
457 smallint flg_export; /* putenv should be done on this var */
458 smallint flg_read_only;
466 #if ENABLE_HUSH_FUNCTIONS
468 struct function *next;
470 struct command *parent_cmd;
473 char *body_as_string;
479 /* "Globals" within this file */
480 /* Sorted roughly by size (smaller offsets == smaller code) */
482 /* interactive_fd != 0 means we are an interactive shell.
483 * If we are, then saved_tty_pgrp can also be != 0, meaning
484 * that controlling tty is available. With saved_tty_pgrp == 0,
485 * job control still works, but terminal signals
486 * (^C, ^Z, ^Y, ^\) won't work at all, and background
487 * process groups can only be created with "cmd &".
488 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
489 * to give tty to the foreground process group,
490 * and will take it back when the group is stopped (^Z)
493 #if ENABLE_HUSH_INTERACTIVE
494 /* 'interactive_fd' is a fd# open to ctty, if we have one
495 * _AND_ if we decided to act interactively */
499 # define G_interactive_fd (G.interactive_fd)
501 # define G_interactive_fd 0
503 #if ENABLE_FEATURE_EDITING
504 line_input_t *line_input_state;
509 #if ENABLE_HUSH_RANDOM_SUPPORT
515 pid_t saved_tty_pgrp;
516 struct pipe *job_list;
517 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
519 # define G_saved_tty_pgrp 0
521 smallint flag_SIGINT;
522 #if ENABLE_HUSH_LOOPS
523 smallint flag_break_continue;
525 #if ENABLE_HUSH_FUNCTIONS
526 /* 0: outside of a function (or sourced file)
527 * -1: inside of a function, ok to use return builtin
528 * 1: return is invoked, skip all till end of func
530 smallint flag_return_in_progress;
533 smallint exiting; /* used to prevent EXIT trap recursion */
534 /* These four support $?, $#, and $1 */
535 smalluint last_exitcode;
536 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
537 smalluint global_args_malloced;
538 smalluint inherited_set_is_saved;
539 /* how many non-NULL argv's we have. NB: $# + 1 */
543 char *argv0_for_re_execing;
545 #if ENABLE_HUSH_LOOPS
546 unsigned depth_break_continue;
547 unsigned depth_of_loop;
551 struct variable *top_var; /* = &G.shell_ver (set in main()) */
552 struct variable shell_ver;
553 #if ENABLE_HUSH_FUNCTIONS
554 struct function *top_func;
555 # if ENABLE_HUSH_LOCAL
556 struct variable **shadowed_vars_pp;
557 unsigned func_nest_level;
560 /* Signal and trap handling */
562 unsigned count_SIGCHLD;
563 unsigned handled_SIGCHLD;
564 smallint we_have_children;
566 /* which signals have non-DFL handler (even with no traps set)? */
567 unsigned non_DFL_mask;
568 char **traps; /* char *traps[NSIG] */
569 sigset_t blocked_set;
570 sigset_t inherited_set;
572 unsigned long memleak_value;
575 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
577 #define G (*ptr_to_globals)
578 /* Not #defining name to G.name - this quickly gets unwieldy
579 * (too many defines). Also, I actually prefer to see when a variable
580 * is global, thus "G." prefix is a useful hint */
581 #define INIT_G() do { \
582 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
586 /* Function prototypes for builtins */
587 static int builtin_cd(char **argv) FAST_FUNC;
588 static int builtin_echo(char **argv) FAST_FUNC;
589 static int builtin_eval(char **argv) FAST_FUNC;
590 static int builtin_exec(char **argv) FAST_FUNC;
591 static int builtin_exit(char **argv) FAST_FUNC;
592 static int builtin_export(char **argv) FAST_FUNC;
594 static int builtin_fg_bg(char **argv) FAST_FUNC;
595 static int builtin_jobs(char **argv) FAST_FUNC;
598 static int builtin_help(char **argv) FAST_FUNC;
600 #if ENABLE_HUSH_LOCAL
601 static int builtin_local(char **argv) FAST_FUNC;
604 static int builtin_memleak(char **argv) FAST_FUNC;
607 static int builtin_printf(char **argv) FAST_FUNC;
609 static int builtin_pwd(char **argv) FAST_FUNC;
610 static int builtin_read(char **argv) FAST_FUNC;
611 static int builtin_set(char **argv) FAST_FUNC;
612 static int builtin_shift(char **argv) FAST_FUNC;
613 static int builtin_source(char **argv) FAST_FUNC;
614 static int builtin_test(char **argv) FAST_FUNC;
615 static int builtin_trap(char **argv) FAST_FUNC;
616 static int builtin_type(char **argv) FAST_FUNC;
617 static int builtin_true(char **argv) FAST_FUNC;
618 static int builtin_umask(char **argv) FAST_FUNC;
619 static int builtin_unset(char **argv) FAST_FUNC;
620 static int builtin_wait(char **argv) FAST_FUNC;
621 #if ENABLE_HUSH_LOOPS
622 static int builtin_break(char **argv) FAST_FUNC;
623 static int builtin_continue(char **argv) FAST_FUNC;
625 #if ENABLE_HUSH_FUNCTIONS
626 static int builtin_return(char **argv) FAST_FUNC;
629 /* Table of built-in functions. They can be forked or not, depending on
630 * context: within pipes, they fork. As simple commands, they do not.
631 * When used in non-forking context, they can change global variables
632 * in the parent shell process. If forked, of course they cannot.
633 * For example, 'unset foo | whatever' will parse and run, but foo will
634 * still be set at the end. */
635 struct built_in_command {
637 int (*b_function)(char **argv) FAST_FUNC;
640 # define BLTIN(cmd, func, help) { cmd, func, help }
642 # define BLTIN(cmd, func, help) { cmd, func }
646 static const struct built_in_command bltins1[] = {
647 BLTIN("." , builtin_source , "Run commands in a file"),
648 BLTIN(":" , builtin_true , NULL),
650 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
652 #if ENABLE_HUSH_LOOPS
653 BLTIN("break" , builtin_break , "Exit from a loop"),
655 BLTIN("cd" , builtin_cd , "Change directory"),
656 #if ENABLE_HUSH_LOOPS
657 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
659 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
660 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
661 BLTIN("exit" , builtin_exit , "Exit"),
662 BLTIN("export" , builtin_export , "Set environment variables"),
664 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
667 BLTIN("help" , builtin_help , NULL),
670 BLTIN("jobs" , builtin_jobs , "List jobs"),
672 #if ENABLE_HUSH_LOCAL
673 BLTIN("local" , builtin_local , "Set local variables"),
676 BLTIN("memleak" , builtin_memleak , NULL),
678 BLTIN("read" , builtin_read , "Input into variable"),
679 #if ENABLE_HUSH_FUNCTIONS
680 BLTIN("return" , builtin_return , "Return from a function"),
682 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
683 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
684 #if ENABLE_HUSH_BASH_COMPAT
685 BLTIN("source" , builtin_source , "Run commands in a file"),
687 BLTIN("trap" , builtin_trap , "Trap signals"),
688 BLTIN("type" , builtin_type , "Show command type"),
689 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
690 BLTIN("umask" , builtin_umask , "Set file creation mask"),
691 BLTIN("unset" , builtin_unset , "Unset variables"),
692 BLTIN("wait" , builtin_wait , "Wait for process"),
694 /* For now, echo and test are unconditionally enabled.
695 * Maybe make it configurable? */
696 static const struct built_in_command bltins2[] = {
697 BLTIN("[" , builtin_test , NULL),
698 BLTIN("echo" , builtin_echo , NULL),
700 BLTIN("printf" , builtin_printf , NULL),
702 BLTIN("pwd" , builtin_pwd , NULL),
703 BLTIN("test" , builtin_test , NULL),
710 /* prevent disasters with G.debug_indent < 0 */
711 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
712 # define debug_enter() (G.debug_indent++)
713 # define debug_leave() (G.debug_indent--)
715 # define indent() ((void)0)
716 # define debug_enter() ((void)0)
717 # define debug_leave() ((void)0)
721 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
724 #ifndef debug_printf_parse
725 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
728 #ifndef debug_printf_exec
729 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
732 #ifndef debug_printf_env
733 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
736 #ifndef debug_printf_jobs
737 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
738 # define DEBUG_JOBS 1
740 # define DEBUG_JOBS 0
743 #ifndef debug_printf_expand
744 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
745 # define DEBUG_EXPAND 1
747 # define DEBUG_EXPAND 0
750 #ifndef debug_printf_varexp
751 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
754 #ifndef debug_printf_glob
755 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
756 # define DEBUG_GLOB 1
758 # define DEBUG_GLOB 0
761 #ifndef debug_printf_list
762 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
765 #ifndef debug_printf_subst
766 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
769 #ifndef debug_printf_clean
770 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
771 # define DEBUG_CLEAN 1
773 # define DEBUG_CLEAN 0
777 static void debug_print_strings(const char *prefix, char **vv)
780 fprintf(stderr, "%s:\n", prefix);
782 fprintf(stderr, " '%s'\n", *vv++);
785 # define debug_print_strings(prefix, vv) ((void)0)
789 /* Leak hunting. Use hush_leaktool.sh for post-processing.
792 static void *xxmalloc(int lineno, size_t size)
794 void *ptr = xmalloc((size + 0xff) & ~0xff);
795 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
798 static void *xxrealloc(int lineno, void *ptr, size_t size)
800 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
801 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
804 static char *xxstrdup(int lineno, const char *str)
806 char *ptr = xstrdup(str);
807 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
810 static void xxfree(void *ptr)
812 fdprintf(2, "free %p\n", ptr);
815 # define xmalloc(s) xxmalloc(__LINE__, s)
816 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
817 # define xstrdup(s) xxstrdup(__LINE__, s)
818 # define free(p) xxfree(p)
822 /* Syntax and runtime errors. They always abort scripts.
823 * In interactive use they usually discard unparsed and/or unexecuted commands
824 * and return to the prompt.
825 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
828 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
829 # define syntax_error(lineno, msg) syntax_error(msg)
830 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
831 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
832 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
833 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
836 static void die_if_script(unsigned lineno, const char *fmt, ...)
841 bb_error_msg("hush.c:%u", lineno);
844 bb_verror_msg(fmt, p, NULL);
846 if (!G_interactive_fd)
850 static void syntax_error(unsigned lineno, const char *msg)
853 die_if_script(lineno, "syntax error: %s", msg);
855 die_if_script(lineno, "syntax error", NULL);
858 static void syntax_error_at(unsigned lineno, const char *msg)
860 die_if_script(lineno, "syntax error at '%s'", msg);
863 static void syntax_error_unterm_str(unsigned lineno, const char *s)
865 die_if_script(lineno, "syntax error: unterminated %s", s);
868 /* It so happens that all such cases are totally fatal
869 * even if shell is interactive: EOF while looking for closing
870 * delimiter. There is nowhere to read stuff from after that,
871 * it's EOF! The only choice is to terminate.
873 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
874 static void syntax_error_unterm_ch(unsigned lineno, char ch)
876 char msg[2] = { ch, '\0' };
877 syntax_error_unterm_str(lineno, msg);
881 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
886 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
890 # undef die_if_script
892 # undef syntax_error_at
893 # undef syntax_error_unterm_ch
894 # undef syntax_error_unterm_str
895 # undef syntax_error_unexpected_ch
897 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
898 # define syntax_error(msg) syntax_error(__LINE__, msg)
899 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
900 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
901 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
902 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
906 #if ENABLE_HUSH_INTERACTIVE
907 static void cmdedit_update_prompt(void);
909 # define cmdedit_update_prompt() ((void)0)
915 /* Replace each \x with x in place, return ptr past NUL. */
916 static char *unbackslash(char *src)
918 char *dst = src = strchrnul(src, '\\');
922 if ((*dst++ = *src++) == '\0')
928 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
949 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
950 v[count1 + count2] = NULL;
953 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
957 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
959 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
960 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
963 #define add_strings_to_strings(strings, add, need_to_dup) \
964 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
967 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
968 static char **add_string_to_strings(char **strings, char *add)
973 return add_strings_to_strings(strings, v, /*dup:*/ 0);
976 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
978 char **ptr = add_string_to_strings(strings, add);
979 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
982 #define add_string_to_strings(strings, add) \
983 xx_add_string_to_strings(__LINE__, strings, add)
986 static void free_strings(char **strings)
1001 /* Helpers for setting new $n and restoring them back
1003 typedef struct save_arg_t {
1007 smallint sv_g_malloced;
1010 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1014 sv->sv_argv0 = argv[0];
1015 sv->sv_g_argv = G.global_argv;
1016 sv->sv_g_argc = G.global_argc;
1017 sv->sv_g_malloced = G.global_args_malloced;
1019 argv[0] = G.global_argv[0]; /* retain $0 */
1020 G.global_argv = argv;
1021 G.global_args_malloced = 0;
1029 static void restore_G_args(save_arg_t *sv, char **argv)
1033 if (G.global_args_malloced) {
1034 /* someone ran "set -- arg1 arg2 ...", undo */
1036 while (*++pp) /* note: does not free $0 */
1038 free(G.global_argv);
1040 argv[0] = sv->sv_argv0;
1041 G.global_argv = sv->sv_g_argv;
1042 G.global_argc = sv->sv_g_argc;
1043 G.global_args_malloced = sv->sv_g_malloced;
1047 /* Basic theory of signal handling in shell
1048 * ========================================
1049 * This does not describe what hush does, rather, it is current understanding
1050 * what it _should_ do. If it doesn't, it's a bug.
1051 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1053 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1054 * is finished or backgrounded. It is the same in interactive and
1055 * non-interactive shells, and is the same regardless of whether
1056 * a user trap handler is installed or a shell special one is in effect.
1057 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1058 * backgrounds (i.e. stops) or kills all members of currently running
1061 * Wait builtin in interruptible by signals for which user trap is set
1062 * or by SIGINT in interactive shell.
1064 * Trap handlers will execute even within trap handlers. (right?)
1066 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1067 * except for handlers set to '' (empty string).
1069 * If job control is off, backgrounded commands ("cmd &")
1070 * have SIGINT, SIGQUIT set to SIG_IGN.
1072 * Commands which are run in command substitution ("`cmd`")
1073 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1075 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1076 * by the shell from its parent.
1078 * Signals which differ from SIG_DFL action
1079 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1082 * SIGTERM (interactive): ignore
1083 * SIGHUP (interactive):
1084 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1085 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1086 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1087 * that all pipe members are stopped. Try this in bash:
1088 * while :; do :; done - ^Z does not background it
1089 * (while :; do :; done) - ^Z backgrounds it
1090 * SIGINT (interactive): wait for last pipe, ignore the rest
1091 * of the command line, show prompt. NB: ^C does not send SIGINT
1092 * to interactive shell while shell is waiting for a pipe,
1093 * since shell is bg'ed (is not in foreground process group).
1094 * Example 1: this waits 5 sec, but does not execute ls:
1095 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1096 * Example 2: this does not wait and does not execute ls:
1097 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1098 * Example 3: this does not wait 5 sec, but executes ls:
1099 * "sleep 5; ls -l" + press ^C
1101 * (What happens to signals which are IGN on shell start?)
1102 * (What happens with signal mask on shell start?)
1104 * Implementation in hush
1105 * ======================
1106 * We use in-kernel pending signal mask to determine which signals were sent.
1107 * We block all signals which we don't want to take action immediately,
1108 * i.e. we block all signals which need to have special handling as described
1109 * above, and all signals which have traps set.
1110 * After each pipe execution, we extract any pending signals via sigtimedwait()
1113 * unsigned non_DFL_mask: a mask of such "special" signals
1114 * sigset_t blocked_set: current blocked signal set
1117 * clear bit in blocked_set unless it is also in non_DFL_mask
1118 * "trap 'cmd' SIGxxx":
1119 * set bit in blocked_set (even if 'cmd' is '')
1120 * after [v]fork, if we plan to be a shell:
1121 * unblock signals with special interactive handling
1122 * (child shell is not interactive),
1123 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1124 * after [v]fork, if we plan to exec:
1125 * POSIX says fork clears pending signal mask in child - no need to clear it.
1126 * Restore blocked signal set to one inherited by shell just prior to exec.
1128 * Note: as a result, we do not use signal handlers much. The only uses
1129 * are to count SIGCHLDs
1130 * and to restore tty pgrp on signal-induced exit.
1133 * Standard says "When a subshell is entered, traps that are not being ignored
1134 * are set to the default actions". bash interprets it so that traps which
1135 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1138 SPECIAL_INTERACTIVE_SIGS = 0
1143 SPECIAL_JOB_SIGS = 0
1151 #if ENABLE_HUSH_FAST
1152 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1155 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1161 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1162 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1163 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1164 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1166 /* Restores tty foreground process group, and exits.
1167 * May be called as signal handler for fatal signal
1168 * (will resend signal to itself, producing correct exit state)
1169 * or called directly with -EXITCODE.
1170 * We also call it if xfunc is exiting. */
1171 static void sigexit(int sig) NORETURN;
1172 static void sigexit(int sig)
1174 /* Disable all signals: job control, SIGPIPE, etc. */
1175 sigprocmask_allsigs(SIG_BLOCK);
1177 /* Careful: we can end up here after [v]fork. Do not restore
1178 * tty pgrp then, only top-level shell process does that */
1179 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1180 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1182 /* Not a signal, just exit */
1186 kill_myself_with_sig(sig); /* does not return */
1190 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1191 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1195 /* Restores tty foreground process group, and exits. */
1196 static void hush_exit(int exitcode) NORETURN;
1197 static void hush_exit(int exitcode)
1199 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1200 /* Prevent recursion:
1201 * trap "echo Hi; exit" EXIT; exit
1203 char *argv[] = { NULL, G.traps[0], NULL };
1212 sigexit(- (exitcode & 0xff));
1218 static int check_and_run_traps(int sig)
1220 static const struct timespec zero_timespec = { 0, 0 };
1221 smalluint save_rcode;
1227 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1232 if (G.traps && G.traps[sig]) {
1233 if (G.traps[sig][0]) {
1234 /* We have user-defined handler */
1235 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1236 save_rcode = G.last_exitcode;
1239 G.last_exitcode = save_rcode;
1240 } /* else: "" trap, ignoring signal */
1243 /* not a trap: special action */
1245 #if ENABLE_HUSH_FAST
1248 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1252 /* Builtin was ^C'ed, make it look prettier: */
1259 /* bash is observed to signal whole process groups,
1260 * not individual processes */
1261 for (job = G.job_list; job; job = job->next) {
1264 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1265 if (kill(- job->pgrp, SIGHUP) == 0)
1266 kill(- job->pgrp, SIGCONT);
1271 default: /* ignored: */
1272 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1280 static const char *get_cwd(int force)
1282 if (force || G.cwd == NULL) {
1283 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1284 * we must not try to free(bb_msg_unknown) */
1285 if (G.cwd == bb_msg_unknown)
1287 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1289 G.cwd = bb_msg_unknown;
1296 * Shell and environment variable support
1298 static struct variable **get_ptr_to_local_var(const char *name)
1300 struct variable **pp;
1301 struct variable *cur;
1306 while ((cur = *pp) != NULL) {
1307 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1314 static struct variable *get_local_var(const char *name)
1316 struct variable **pp = get_ptr_to_local_var(name);
1322 static const char* FAST_FUNC get_local_var_value(const char *name)
1324 struct variable **pp = get_ptr_to_local_var(name);
1326 return strchr((*pp)->varstr, '=') + 1;
1327 if (strcmp(name, "PPID") == 0)
1328 return utoa(G.root_ppid);
1329 // bash compat: UID? EUID?
1330 #if ENABLE_HUSH_RANDOM_SUPPORT
1331 if (strcmp(name, "RANDOM") == 0) {
1332 return utoa(next_random(&G.random_gen));
1338 /* str holds "NAME=VAL" and is expected to be malloced.
1339 * We take ownership of it.
1341 * 0: do not change export flag
1342 * (if creating new variable, flag will be 0)
1343 * 1: set export flag and putenv the variable
1344 * -1: clear export flag and unsetenv the variable
1345 * flg_read_only is set only when we handle -R var=val
1347 #if !BB_MMU && ENABLE_HUSH_LOCAL
1348 /* all params are used */
1349 #elif BB_MMU && ENABLE_HUSH_LOCAL
1350 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1351 set_local_var(str, flg_export, local_lvl)
1352 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1353 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1354 set_local_var(str, flg_export)
1355 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1356 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1357 set_local_var(str, flg_export, flg_read_only)
1359 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1361 struct variable **var_pp;
1362 struct variable *cur;
1366 eq_sign = strchr(str, '=');
1367 if (!eq_sign) { /* not expected to ever happen? */
1372 name_len = eq_sign - str + 1; /* including '=' */
1373 var_pp = &G.top_var;
1374 while ((cur = *var_pp) != NULL) {
1375 if (strncmp(cur->varstr, str, name_len) != 0) {
1376 var_pp = &cur->next;
1379 /* We found an existing var with this name */
1380 if (cur->flg_read_only) {
1384 bb_error_msg("%s: readonly variable", str);
1388 if (flg_export == -1) { // "&& cur->flg_export" ?
1389 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1394 #if ENABLE_HUSH_LOCAL
1395 if (cur->func_nest_level < local_lvl) {
1396 /* New variable is declared as local,
1397 * and existing one is global, or local
1398 * from enclosing function.
1399 * Remove and save old one: */
1400 *var_pp = cur->next;
1401 cur->next = *G.shadowed_vars_pp;
1402 *G.shadowed_vars_pp = cur;
1403 /* bash 3.2.33(1) and exported vars:
1405 * # f() { local z=a; env | grep ^z; }
1411 if (cur->flg_export)
1416 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1421 if (cur->max_len != 0) {
1422 if (cur->max_len >= strlen(str)) {
1423 /* This one is from startup env, reuse space */
1424 strcpy(cur->varstr, str);
1428 /* max_len == 0 signifies "malloced" var, which we can
1429 * (and has to) free */
1433 goto set_str_and_exp;
1436 /* Not found - create new variable struct */
1437 cur = xzalloc(sizeof(*cur));
1438 #if ENABLE_HUSH_LOCAL
1439 cur->func_nest_level = local_lvl;
1441 cur->next = *var_pp;
1447 cur->flg_read_only = flg_read_only;
1450 if (flg_export == 1)
1451 cur->flg_export = 1;
1452 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1453 cmdedit_update_prompt();
1454 if (cur->flg_export) {
1455 if (flg_export == -1) {
1456 cur->flg_export = 0;
1457 /* unsetenv was already done */
1459 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1460 return putenv(cur->varstr);
1466 /* Used at startup and after each cd */
1467 static void set_pwd_var(int exp)
1469 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1470 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1473 static int unset_local_var_len(const char *name, int name_len)
1475 struct variable *cur;
1476 struct variable **var_pp;
1479 return EXIT_SUCCESS;
1480 var_pp = &G.top_var;
1481 while ((cur = *var_pp) != NULL) {
1482 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1483 if (cur->flg_read_only) {
1484 bb_error_msg("%s: readonly variable", name);
1485 return EXIT_FAILURE;
1487 *var_pp = cur->next;
1488 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1489 bb_unsetenv(cur->varstr);
1490 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1491 cmdedit_update_prompt();
1495 return EXIT_SUCCESS;
1497 var_pp = &cur->next;
1499 return EXIT_SUCCESS;
1502 static int unset_local_var(const char *name)
1504 return unset_local_var_len(name, strlen(name));
1507 static void unset_vars(char **strings)
1515 const char *eq = strchrnul(*v, '=');
1516 unset_local_var_len(*v, (int)(eq - *v));
1522 #if ENABLE_SH_MATH_SUPPORT
1523 # define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1524 # define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1525 static char* FAST_FUNC endofname(const char *name)
1533 if (!is_in_name(*p))
1540 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1542 char *var = xasprintf("%s=%s", name, val);
1543 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1548 * Helpers for "var1=val1 var2=val2 cmd" feature
1550 static void add_vars(struct variable *var)
1552 struct variable *next;
1556 var->next = G.top_var;
1558 if (var->flg_export) {
1559 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1560 putenv(var->varstr);
1562 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1568 static struct variable *set_vars_and_save_old(char **strings)
1571 struct variable *old = NULL;
1577 struct variable *var_p;
1578 struct variable **var_pp;
1581 eq = strchr(*s, '=');
1584 var_pp = get_ptr_to_local_var(*s);
1587 /* Remove variable from global linked list */
1589 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1590 *var_pp = var_p->next;
1591 /* Add it to returned list */
1595 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1606 static int FAST_FUNC static_get(struct in_str *i)
1616 static int FAST_FUNC static_peek(struct in_str *i)
1621 #if ENABLE_HUSH_INTERACTIVE
1623 static void cmdedit_update_prompt(void)
1625 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1626 G.PS1 = get_local_var_value("PS1");
1629 G.PS2 = get_local_var_value("PS2");
1637 static const char* setup_prompt_string(int promptmode)
1639 const char *prompt_str;
1640 debug_printf("setup_prompt_string %d ", promptmode);
1641 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1642 /* Set up the prompt */
1643 if (promptmode == 0) { /* PS1 */
1645 /* bash uses $PWD value, even if it is set by user.
1646 * It uses current dir only if PWD is unset.
1647 * We always use current dir. */
1648 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1653 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1654 debug_printf("result '%s'\n", prompt_str);
1658 static void get_user_input(struct in_str *i)
1661 const char *prompt_str;
1663 prompt_str = setup_prompt_string(i->promptmode);
1664 # if ENABLE_FEATURE_EDITING
1665 /* Enable command line editing only while a command line
1666 * is actually being read */
1669 /* buglet: SIGINT will not make new prompt to appear _at once_,
1670 * only after <Enter>. (^C will work) */
1671 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1672 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1673 check_and_run_traps(0);
1674 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1675 i->eof_flag = (r < 0);
1676 if (i->eof_flag) { /* EOF/error detected */
1677 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1678 G.user_input_buf[1] = '\0';
1683 fputs(prompt_str, stdout);
1685 G.user_input_buf[0] = r = fgetc(i->file);
1686 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1687 //do we need check_and_run_traps(0)? (maybe only if stdin)
1688 } while (G.flag_SIGINT);
1689 i->eof_flag = (r == EOF);
1691 i->p = G.user_input_buf;
1694 #endif /* INTERACTIVE */
1696 /* This is the magic location that prints prompts
1697 * and gets data back from the user */
1698 static int FAST_FUNC file_get(struct in_str *i)
1702 /* If there is data waiting, eat it up */
1703 if (i->p && *i->p) {
1704 #if ENABLE_HUSH_INTERACTIVE
1708 if (i->eof_flag && !*i->p)
1710 /* note: ch is never NUL */
1712 /* need to double check i->file because we might be doing something
1713 * more complicated by now, like sourcing or substituting. */
1714 #if ENABLE_HUSH_INTERACTIVE
1715 if (G_interactive_fd && i->promptme && i->file == stdin) {
1718 } while (!*i->p); /* need non-empty line */
1719 i->promptmode = 1; /* PS2 */
1724 do ch = fgetc(i->file); while (ch == '\0');
1726 debug_printf("file_get: got '%c' %d\n", ch, ch);
1727 #if ENABLE_HUSH_INTERACTIVE
1734 /* All callers guarantee this routine will never
1735 * be used right after a newline, so prompting is not needed.
1737 static int FAST_FUNC file_peek(struct in_str *i)
1740 if (i->p && *i->p) {
1741 if (i->eof_flag && !i->p[1])
1744 /* note: ch is never NUL */
1746 do ch = fgetc(i->file); while (ch == '\0');
1747 i->eof_flag = (ch == EOF);
1748 i->peek_buf[0] = ch;
1749 i->peek_buf[1] = '\0';
1751 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1755 static void setup_file_in_str(struct in_str *i, FILE *f)
1757 i->peek = file_peek;
1759 #if ENABLE_HUSH_INTERACTIVE
1761 i->promptmode = 0; /* PS1 */
1767 static void setup_string_in_str(struct in_str *i, const char *s)
1769 i->peek = static_peek;
1770 i->get = static_get;
1771 #if ENABLE_HUSH_INTERACTIVE
1773 i->promptmode = 0; /* PS1 */
1783 #define B_CHUNK (32 * sizeof(char*))
1785 static void o_reset_to_empty_unquoted(o_string *o)
1793 static void o_free(o_string *o)
1796 memset(o, 0, sizeof(*o));
1799 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1804 static void o_grow_by(o_string *o, int len)
1806 if (o->length + len > o->maxlen) {
1807 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1808 o->data = xrealloc(o->data, 1 + o->maxlen);
1812 static void o_addchr(o_string *o, int ch)
1814 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1816 o->data[o->length] = ch;
1818 o->data[o->length] = '\0';
1821 static void o_addblock(o_string *o, const char *str, int len)
1824 memcpy(&o->data[o->length], str, len);
1826 o->data[o->length] = '\0';
1829 static void o_addstr(o_string *o, const char *str)
1831 o_addblock(o, str, strlen(str));
1835 static void nommu_addchr(o_string *o, int ch)
1841 # define nommu_addchr(o, str) ((void)0)
1844 static void o_addstr_with_NUL(o_string *o, const char *str)
1846 o_addblock(o, str, strlen(str) + 1);
1849 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1854 && (*str != '*' && *str != '?' && *str != '[')
1862 #undef HUSH_BRACE_EXP
1864 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1865 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1866 * Apparently, on unquoted $v bash still does globbing
1867 * ("v='*.txt'; echo $v" prints all .txt files),
1868 * but NOT brace expansion! Thus, there should be TWO independent
1869 * quoting mechanisms on $v expansion side: one protects
1870 * $v from brace expansion, and other additionally protects "$v" against globbing.
1871 * We have only second one.
1874 #ifdef HUSH_BRACE_EXP
1875 # define MAYBE_BRACES "{}"
1877 # define MAYBE_BRACES ""
1880 /* My analysis of quoting semantics tells me that state information
1881 * is associated with a destination, not a source.
1883 static void o_addqchr(o_string *o, int ch)
1886 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1891 o->data[o->length] = '\\';
1894 o->data[o->length] = ch;
1896 o->data[o->length] = '\0';
1899 static void o_addQchr(o_string *o, int ch)
1902 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1904 o->data[o->length] = '\\';
1908 o->data[o->length] = ch;
1910 o->data[o->length] = '\0';
1913 static void o_addQstr(o_string *o, const char *str, int len)
1916 o_addblock(o, str, len);
1922 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1923 if (ordinary_cnt > len) /* paranoia */
1925 o_addblock(o, str, ordinary_cnt);
1926 if (ordinary_cnt == len)
1928 str += ordinary_cnt;
1929 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1933 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1935 o->data[o->length] = '\\';
1939 o->data[o->length] = ch;
1941 o->data[o->length] = '\0';
1945 /* A special kind of o_string for $VAR and `cmd` expansion.
1946 * It contains char* list[] at the beginning, which is grown in 16 element
1947 * increments. Actual string data starts at the next multiple of 16 * (char*).
1948 * list[i] contains an INDEX (int!) into this string data.
1949 * It means that if list[] needs to grow, data needs to be moved higher up
1950 * but list[i]'s need not be modified.
1951 * NB: remembering how many list[i]'s you have there is crucial.
1952 * o_finalize_list() operation post-processes this structure - calculates
1953 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1955 #if DEBUG_EXPAND || DEBUG_GLOB
1956 static void debug_print_list(const char *prefix, o_string *o, int n)
1958 char **list = (char**)o->data;
1959 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1963 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1964 prefix, list, n, string_start, o->length, o->maxlen);
1967 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1968 o->data + (int)list[i] + string_start,
1969 o->data + (int)list[i] + string_start);
1973 const char *p = o->data + (int)list[n - 1] + string_start;
1975 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1979 # define debug_print_list(prefix, o, n) ((void)0)
1982 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1983 * in list[n] so that it points past last stored byte so far.
1984 * It returns n+1. */
1985 static int o_save_ptr_helper(o_string *o, int n)
1987 char **list = (char**)o->data;
1991 if (!o->has_empty_slot) {
1992 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1993 string_len = o->length - string_start;
1994 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1995 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1996 /* list[n] points to string_start, make space for 16 more pointers */
1997 o->maxlen += 0x10 * sizeof(list[0]);
1998 o->data = xrealloc(o->data, o->maxlen + 1);
1999 list = (char**)o->data;
2000 memmove(list + n + 0x10, list + n, string_len);
2001 o->length += 0x10 * sizeof(list[0]);
2003 debug_printf_list("list[%d]=%d string_start=%d\n",
2004 n, string_len, string_start);
2007 /* We have empty slot at list[n], reuse without growth */
2008 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2009 string_len = o->length - string_start;
2010 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2011 n, string_len, string_start);
2012 o->has_empty_slot = 0;
2014 list[n] = (char*)(ptrdiff_t)string_len;
2018 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2019 static int o_get_last_ptr(o_string *o, int n)
2021 char **list = (char**)o->data;
2022 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2024 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2027 #ifdef HUSH_BRACE_EXP
2028 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2029 * first, it processes even {a} (no commas), second,
2030 * I didn't manage to make it return strings when they don't match
2031 * existing files. Need to re-implement it.
2035 static int glob_needed(const char *s)
2044 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2050 /* Return pointer to next closing brace or to comma */
2051 static const char *next_brace_sub(const char *cp)
2055 while (*cp != '\0') {
2062 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2064 if (*cp++ == '{') /*}*/
2068 return *cp != '\0' ? cp : NULL;
2070 /* Recursive brace globber. Note: may garble pattern[]. */
2071 static int glob_brace(char *pattern, o_string *o, int n)
2073 char *new_pattern_buf;
2080 debug_printf_glob("glob_brace('%s')\n", pattern);
2086 if (*begin == '{') /*}*/ {
2087 /* Find the first sub-pattern and at the same time
2088 * find the rest after the closing brace */
2089 next = next_brace_sub(begin);
2091 /* An illegal expression */
2094 /*{*/ if (*next == '}') {
2095 /* "{abc}" with no commas - illegal
2096 * brace expr, disregard and skip it */
2102 if (*begin == '\\' && begin[1] != '\0')
2106 debug_printf_glob("begin:%s\n", begin);
2107 debug_printf_glob("next:%s\n", next);
2109 /* Now find the end of the whole brace expression */
2111 /*{*/ while (*rest != '}') {
2112 rest = next_brace_sub(rest);
2114 /* An illegal expression */
2117 debug_printf_glob("rest:%s\n", rest);
2119 rest_len = strlen(++rest) + 1;
2121 /* We are sure the brace expression is well-formed */
2123 /* Allocate working buffer large enough for our work */
2124 new_pattern_buf = xmalloc(strlen(pattern));
2126 /* We have a brace expression. BEGIN points to the opening {,
2127 * NEXT points past the terminator of the first element, and REST
2128 * points past the final }. We will accumulate result names from
2129 * recursive runs for each brace alternative in the buffer using
2134 /* Construct the new glob expression */
2137 mempcpy(new_pattern_buf,
2138 /* We know the prefix for all sub-patterns */
2139 pattern, begin - pattern),
2143 /* Note: glob_brace() may garble new_pattern_buf[].
2144 * That's why we re-copy prefix every time (1st memcpy above).
2146 n = glob_brace(new_pattern_buf, o, n);
2147 /*{*/ if (*next == '}') {
2148 /* We saw the last entry */
2152 next = next_brace_sub(next);
2154 free(new_pattern_buf);
2162 memset(&globdata, 0, sizeof(globdata));
2163 gr = glob(pattern, 0, NULL, &globdata);
2164 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2166 if (gr == GLOB_NOMATCH) {
2167 globfree(&globdata);
2168 /* NB: garbles parameter */
2169 unbackslash(pattern);
2170 o_addstr_with_NUL(o, pattern);
2171 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2172 return o_save_ptr_helper(o, n);
2174 if (gr == GLOB_NOSPACE)
2175 bb_error_msg_and_die(bb_msg_memory_exhausted);
2176 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2177 * but we didn't specify it. Paranoia again. */
2178 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2180 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2181 char **argv = globdata.gl_pathv;
2183 o_addstr_with_NUL(o, *argv);
2184 n = o_save_ptr_helper(o, n);
2190 globfree(&globdata);
2194 /* Performs globbing on last list[],
2195 * saving each result as a new list[].
2197 static int o_glob(o_string *o, int n)
2199 char *pattern, *copy;
2201 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2203 return o_save_ptr_helper(o, n);
2204 pattern = o->data + o_get_last_ptr(o, n);
2205 debug_printf_glob("glob pattern '%s'\n", pattern);
2206 if (!glob_needed(pattern)) {
2207 /* unbackslash last string in o in place, fix length */
2208 o->length = unbackslash(pattern) - o->data;
2209 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2210 return o_save_ptr_helper(o, n);
2213 copy = xstrdup(pattern);
2214 /* "forget" pattern in o */
2215 o->length = pattern - o->data;
2216 n = glob_brace(copy, o, n);
2219 debug_print_list("o_glob returning", o, n);
2223 #else /* !HUSH_BRACE_EXP */
2226 static int glob_needed(const char *s)
2235 if (*s == '*' || *s == '[' || *s == '?')
2241 /* Performs globbing on last list[],
2242 * saving each result as a new list[].
2244 static int o_glob(o_string *o, int n)
2250 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2252 return o_save_ptr_helper(o, n);
2253 pattern = o->data + o_get_last_ptr(o, n);
2254 debug_printf_glob("glob pattern '%s'\n", pattern);
2255 if (!glob_needed(pattern)) {
2257 /* unbackslash last string in o in place, fix length */
2258 o->length = unbackslash(pattern) - o->data;
2259 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2260 return o_save_ptr_helper(o, n);
2263 memset(&globdata, 0, sizeof(globdata));
2264 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2265 * If we glob "*.\*" and don't find anything, we need
2266 * to fall back to using literal "*.*", but GLOB_NOCHECK
2267 * will return "*.\*"!
2269 gr = glob(pattern, 0, NULL, &globdata);
2270 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2272 if (gr == GLOB_NOMATCH) {
2273 globfree(&globdata);
2276 if (gr == GLOB_NOSPACE)
2277 bb_error_msg_and_die(bb_msg_memory_exhausted);
2278 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2279 * but we didn't specify it. Paranoia again. */
2280 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2282 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2283 char **argv = globdata.gl_pathv;
2284 /* "forget" pattern in o */
2285 o->length = pattern - o->data;
2287 o_addstr_with_NUL(o, *argv);
2288 n = o_save_ptr_helper(o, n);
2294 globfree(&globdata);
2296 debug_print_list("o_glob returning", o, n);
2300 #endif /* !HUSH_BRACE_EXP */
2302 /* If o->o_glob == 1, glob the string so far remembered.
2303 * Otherwise, just finish current list[] and start new */
2304 static int o_save_ptr(o_string *o, int n)
2306 if (o->o_glob) { /* if globbing is requested */
2307 /* If o->has_empty_slot, list[n] was already globbed
2308 * (if it was requested back then when it was filled)
2309 * so don't do that again! */
2310 if (!o->has_empty_slot)
2311 return o_glob(o, n); /* o_save_ptr_helper is inside */
2313 return o_save_ptr_helper(o, n);
2316 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2317 static char **o_finalize_list(o_string *o, int n)
2322 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2324 debug_print_list("finalized", o, n);
2325 debug_printf_expand("finalized n:%d\n", n);
2326 list = (char**)o->data;
2327 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2331 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2337 /* Expansion can recurse */
2338 #if ENABLE_HUSH_TICK
2339 static int process_command_subs(o_string *dest, const char *s);
2341 static char *expand_string_to_string(const char *str);
2343 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2344 parse_stream_dquoted(dest, input, dquote_end)
2346 static int parse_stream_dquoted(o_string *as_string,
2348 struct in_str *input,
2351 /* expand_strvec_to_strvec() takes a list of strings, expands
2352 * all variable references within and returns a pointer to
2353 * a list of expanded strings, possibly with larger number
2354 * of strings. (Think VAR="a b"; echo $VAR).
2355 * This new list is allocated as a single malloc block.
2356 * NULL-terminated list of char* pointers is at the beginning of it,
2357 * followed by strings themself.
2358 * Caller can deallocate entire list by single free(list). */
2360 /* Store given string, finalizing the word and starting new one whenever
2361 * we encounter IFS char(s). This is used for expanding variable values.
2362 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2363 static int expand_on_ifs(o_string *output, int n, const char *str)
2366 int word_len = strcspn(str, G.ifs);
2368 if (output->o_escape || !output->o_glob)
2369 o_addQstr(output, str, word_len);
2370 else /* protect backslashes against globbing up :) */
2371 o_addblock_duplicate_backslash(output, str, word_len);
2374 if (!*str) /* EOL - do not finalize word */
2376 o_addchr(output, '\0');
2377 debug_print_list("expand_on_ifs", output, n);
2378 n = o_save_ptr(output, n);
2379 str += strspn(str, G.ifs); /* skip ifs chars */
2381 debug_print_list("expand_on_ifs[1]", output, n);
2385 /* Helper to expand $((...)) and heredoc body. These act as if
2386 * they are in double quotes, with the exception that they are not :).
2387 * Just the rules are similar: "expand only $var and `cmd`"
2389 * Returns malloced string.
2390 * As an optimization, we return NULL if expansion is not needed.
2392 static char *expand_pseudo_dquoted(const char *str)
2395 struct in_str input;
2396 o_string dest = NULL_O_STRING;
2398 if (strchr(str, '$') == NULL
2399 #if ENABLE_HUSH_TICK
2400 && strchr(str, '`') == NULL
2406 /* We need to expand. Example:
2407 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2409 setup_string_in_str(&input, str);
2410 parse_stream_dquoted(NULL, &dest, &input, EOF);
2411 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2412 exp_str = expand_string_to_string(dest.data);
2413 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2414 o_free_unsafe(&dest);
2418 #if ENABLE_SH_MATH_SUPPORT
2419 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
2421 arith_eval_hooks_t hooks;
2425 hooks.lookupvar = get_local_var_value;
2426 hooks.setvar = set_local_var_from_halves;
2427 hooks.endofname = endofname;
2428 exp_str = expand_pseudo_dquoted(arg);
2429 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
2435 /* Expand all variable references in given string, adding words to list[]
2436 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2437 * to be filled). This routine is extremely tricky: has to deal with
2438 * variables/parameters with whitespace, $* and $@, and constructs like
2439 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2440 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2442 /* or_mask is either 0 (normal case) or 0x80 -
2443 * expansion of right-hand side of assignment == 1-element expand.
2444 * It will also do no globbing, and thus we must not backslash-quote!
2451 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2452 debug_print_list("expand_vars_to_list", output, n);
2453 n = o_save_ptr(output, n);
2454 debug_print_list("expand_vars_to_list[0]", output, n);
2456 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2459 char *to_be_freed = NULL;
2460 const char *val = NULL;
2461 #if ENABLE_HUSH_TICK
2462 o_string subst_result = NULL_O_STRING;
2464 #if ENABLE_SH_MATH_SUPPORT
2465 char arith_buf[sizeof(arith_t)*3 + 2];
2467 o_addblock(output, arg, p - arg);
2468 debug_print_list("expand_vars_to_list[1]", output, n);
2470 p = strchr(p, SPECIAL_VAR_SYMBOL);
2472 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2473 /* "$@" is special. Even if quoted, it can still
2474 * expand to nothing (not even an empty string) */
2475 if ((first_ch & 0x7f) != '@')
2476 ored_ch |= first_ch;
2478 switch (first_ch & 0x7f) {
2479 /* Highest bit in first_ch indicates that var is double-quoted */
2483 if (!G.global_argv[i])
2485 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2486 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2487 smallint sv = output->o_escape;
2488 /* unquoted var's contents should be globbed, so don't escape */
2489 output->o_escape = 0;
2490 while (G.global_argv[i]) {
2491 n = expand_on_ifs(output, n, G.global_argv[i]);
2492 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2493 if (G.global_argv[i++][0] && G.global_argv[i]) {
2494 /* this argv[] is not empty and not last:
2495 * put terminating NUL, start new word */
2496 o_addchr(output, '\0');
2497 debug_print_list("expand_vars_to_list[2]", output, n);
2498 n = o_save_ptr(output, n);
2499 debug_print_list("expand_vars_to_list[3]", output, n);
2502 output->o_escape = sv;
2504 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2505 * and in this case should treat it like '$*' - see 'else...' below */
2506 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2508 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2509 if (++i >= G.global_argc)
2511 o_addchr(output, '\0');
2512 debug_print_list("expand_vars_to_list[4]", output, n);
2513 n = o_save_ptr(output, n);
2515 } else { /* quoted $*: add as one word */
2517 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2518 if (!G.global_argv[++i])
2521 o_addchr(output, G.ifs[0]);
2525 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2526 /* "Empty variable", used to make "" etc to not disappear */
2530 #if ENABLE_HUSH_TICK
2531 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2534 /* Can't just stuff it into output o_string,
2535 * expanded result may need to be globbed
2536 * and $IFS-splitted */
2537 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2538 G.last_exitcode = process_command_subs(&subst_result, arg);
2539 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2540 val = subst_result.data;
2543 #if ENABLE_SH_MATH_SUPPORT
2544 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2548 arg++; /* skip '+' */
2549 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2550 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2551 res = expand_and_evaluate_arith(arg, &errcode);
2554 const char *msg = "error in arithmetic";
2557 msg = "exponent less than 0";
2560 msg = "divide by 0";
2563 msg = "expression recursion loop detected";
2568 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2569 sprintf(arith_buf, arith_t_fmt, res);
2574 default: { /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2578 char exp_save = exp_save; /* for compiler */
2579 char *exp_saveptr; /* points to expansion operator */
2580 char *exp_word = exp_word; /* for compiler */
2584 exp_saveptr = arg[1] ? strchr("%#:-=+?", arg[1]) : NULL;
2585 first_char = arg[0] = first_ch & 0x7f;
2588 if (first_char == '#' && arg[1] && !exp_saveptr) {
2589 /* handle length expansion ${#var} */
2593 /* maybe handle parameter expansion */
2594 if (exp_saveptr /* if 2nd char is one of expansion operators */
2595 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
2597 /* ${?:0}, ${#[:]%0} etc */
2598 exp_saveptr = var + 1;
2600 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
2601 exp_saveptr = var+1 + strcspn(var+1, "%#:-=+?");
2603 exp_op = exp_save = *exp_saveptr;
2605 exp_word = exp_saveptr + 1;
2606 if (exp_op == ':') {
2607 exp_op = *exp_word++;
2608 if (ENABLE_HUSH_BASH_COMPAT
2609 && (exp_op == '\0' || !strchr("%#:-=+?"+3, exp_op))
2611 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
2616 *exp_saveptr = '\0';
2617 } /* else: it's not an expansion op, but bare ${var} */
2620 /* lookup the variable in question */
2621 if (isdigit(var[0])) {
2622 /* parse_dollar() should have vetted var for us */
2624 if (i < G.global_argc)
2625 val = G.global_argv[i];
2626 /* else val remains NULL: $N with too big N */
2630 val = utoa(G.root_pid);
2632 case '!': /* bg pid */
2633 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2635 case '?': /* exitcode */
2636 val = utoa(G.last_exitcode);
2638 case '#': /* argc */
2639 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2642 val = get_local_var_value(var);
2646 /* handle any expansions */
2647 if (exp_op == 'L') {
2648 debug_printf_expand("expand: length(%s)=", val);
2649 val = utoa(val ? strlen(val) : 0);
2650 debug_printf_expand("%s\n", val);
2651 } else if (exp_op) {
2652 if (exp_op == '%' || exp_op == '#') {
2653 /* Standard-mandated substring removal ops:
2654 * ${parameter%word} - remove smallest suffix pattern
2655 * ${parameter%%word} - remove largest suffix pattern
2656 * ${parameter#word} - remove smallest prefix pattern
2657 * ${parameter##word} - remove largest prefix pattern
2659 * Word is expanded to produce a glob pattern.
2660 * Then var's value is matched to it and matching part removed.
2665 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2666 if (exp_op == *exp_word) /* ## or %% */
2668 val = to_be_freed = xstrdup(val);
2670 char *exp_exp_word = expand_pseudo_dquoted(exp_word);
2672 exp_word = exp_exp_word;
2673 loc = scan(to_be_freed, exp_word, match_at_left);
2674 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
2675 // exp_op, to_be_freed, exp_word, loc);
2678 if (loc) { /* match was found */
2679 if (match_at_left) /* # or ## */
2685 } else if (exp_op == ':') {
2686 #if ENABLE_HUSH_BASH_COMPAT
2687 /* It's ${var:N[:M]} bashism.
2688 * Note that in encoded form it has TWO parts:
2689 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
2694 beg = expand_and_evaluate_arith(exp_word, &errcode);
2695 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
2696 *p++ = SPECIAL_VAR_SYMBOL;
2698 p = strchr(p, SPECIAL_VAR_SYMBOL);
2700 len = expand_and_evaluate_arith(exp_word, &errcode);
2701 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
2703 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
2704 if (beg < 0) /* bash compat */
2706 debug_printf_varexp("from val:'%s'\n", val);
2707 if (len == 0 || !val || beg >= strlen(val))
2710 /* Paranoia. What if user entered 9999999999999
2711 * which fits in arith_t but not int? */
2714 val = to_be_freed = xstrndup(val + beg, len);
2716 debug_printf_varexp("val:'%s'\n", val);
2720 die_if_script("malformed ${%s:...}", var);
2723 } else { /* one of "-=+?" */
2724 /* Standard-mandated substitution ops:
2725 * ${var?word} - indicate error if unset
2726 * If var is unset, word (or a message indicating it is unset
2727 * if word is null) is written to standard error
2728 * and the shell exits with a non-zero exit status.
2729 * Otherwise, the value of var is substituted.
2730 * ${var-word} - use default value
2731 * If var is unset, word is substituted.
2732 * ${var=word} - assign and use default value
2733 * If var is unset, word is assigned to var.
2734 * In all cases, final value of var is substituted.
2735 * ${var+word} - use alternative value
2736 * If var is unset, null is substituted.
2737 * Otherwise, word is substituted.
2739 * Word is subjected to tilde expansion, parameter expansion,
2740 * command substitution, and arithmetic expansion.
2741 * If word is not needed, it is not expanded.
2743 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2744 * but also treat null var as if it is unset.
2746 int use_word = (!val || ((exp_save == ':') && !val[0]));
2748 use_word = !use_word;
2749 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2750 (exp_save == ':') ? "true" : "false", use_word);
2752 to_be_freed = expand_pseudo_dquoted(exp_word);
2754 exp_word = to_be_freed;
2755 if (exp_op == '?') {
2756 /* mimic bash message */
2757 die_if_script("%s: %s",
2759 exp_word[0] ? exp_word : "parameter null or not set"
2761 //TODO: how interactive bash aborts expansion mid-command?
2766 if (exp_op == '=') {
2767 /* ${var=[word]} or ${var:=[word]} */
2768 if (isdigit(var[0]) || var[0] == '#') {
2769 /* mimic bash message */
2770 die_if_script("$%s: cannot assign in this way", var);
2773 char *new_var = xasprintf("%s=%s", var, val);
2774 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2778 } /* one of "-=+?" */
2780 *exp_saveptr = exp_save;
2784 #if ENABLE_HUSH_TICK
2787 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2788 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2790 /* unquoted var's contents should be globbed, so don't escape */
2791 smallint sv = output->o_escape;
2792 output->o_escape = 0;
2793 n = expand_on_ifs(output, n, val);
2795 output->o_escape = sv;
2797 } else { /* quoted $VAR, val will be appended below */
2798 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2801 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2804 o_addQstr(output, val, strlen(val));
2807 /* Do the check to avoid writing to a const string */
2808 if (*p != SPECIAL_VAR_SYMBOL)
2809 *p = SPECIAL_VAR_SYMBOL;
2811 #if ENABLE_HUSH_TICK
2812 o_free(&subst_result);
2815 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2818 debug_print_list("expand_vars_to_list[a]", output, n);
2819 /* this part is literal, and it was already pre-quoted
2820 * if needed (much earlier), do not use o_addQstr here! */
2821 o_addstr_with_NUL(output, arg);
2822 debug_print_list("expand_vars_to_list[b]", output, n);
2823 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2824 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2827 /* allow to reuse list[n] later without re-growth */
2828 output->has_empty_slot = 1;
2830 o_addchr(output, '\0');
2835 static char **expand_variables(char **argv, int or_mask)
2840 o_string output = NULL_O_STRING;
2842 if (or_mask & 0x100) {
2843 output.o_escape = 1; /* protect against globbing for "$var" */
2844 /* (unquoted $var will temporarily switch it off) */
2851 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2854 debug_print_list("expand_variables", &output, n);
2856 /* output.data (malloced in one block) gets returned in "list" */
2857 list = o_finalize_list(&output, n);
2858 debug_print_strings("expand_variables[1]", list);
2862 static char **expand_strvec_to_strvec(char **argv)
2864 return expand_variables(argv, 0x100);
2867 #if ENABLE_HUSH_BASH_COMPAT
2868 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2870 return expand_variables(argv, 0x80);
2874 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2875 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2880 o_string output = NULL_O_STRING;
2885 int is_var = is_well_formed_var_name(*v, '=');
2886 /* is_var * 0x80: singleword expansion for vars */
2887 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2889 /* Subtle! expand_vars_to_list did not glob last word yet.
2890 * It does this only when fed with further data.
2891 * Therefore we set globbing flags AFTER it, not before:
2894 /* if it is not recognizably abc=...; then: */
2895 output.o_escape = !is_var; /* protect against globbing for "$var" */
2896 /* (unquoted $var will temporarily switch it off) */
2897 output.o_glob = !is_var; /* and indeed do globbing */
2900 debug_print_list("expand_cond", &output, n);
2902 /* output.data (malloced in one block) gets returned in "list" */
2903 list = o_finalize_list(&output, n);
2904 debug_print_strings("expand_cond[1]", list);
2909 /* Used for expansion of right hand of assignments */
2910 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2912 static char *expand_string_to_string(const char *str)
2914 char *argv[2], **list;
2916 argv[0] = (char*)str;
2918 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2920 if (!list[0] || list[1])
2921 bb_error_msg_and_die("BUG in varexp2");
2922 /* actually, just move string 2*sizeof(char*) bytes back */
2923 overlapping_strcpy((char*)list, list[0]);
2924 unbackslash((char*)list);
2925 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2929 /* Used for "eval" builtin */
2930 static char* expand_strvec_to_string(char **argv)
2934 list = expand_variables(argv, 0x80);
2935 /* Convert all NULs to spaces */
2940 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2941 bb_error_msg_and_die("BUG in varexp3");
2942 /* bash uses ' ' regardless of $IFS contents */
2947 overlapping_strcpy((char*)list, list[0]);
2948 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2952 static char **expand_assignments(char **argv, int count)
2956 /* Expand assignments into one string each */
2957 for (i = 0; i < count; i++) {
2958 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2966 void re_execute_shell(char ***to_free, const char *s,
2967 char *g_argv0, char **g_argv,
2968 char **builtin_argv) NORETURN;
2970 static void reset_traps_to_defaults(void)
2972 /* This function is always called in a child shell
2973 * after fork (not vfork, NOMMU doesn't use this function).
2978 /* Child shells are not interactive.
2979 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2980 * Testcase: (while :; do :; done) + ^Z should background.
2981 * Same goes for SIGTERM, SIGHUP, SIGINT.
2983 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2984 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2986 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2987 * Stupid. It can be done with *single* &= op, but we can't use
2988 * the fact that G.blocked_set is implemented as a bitmask
2990 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2994 /* Careful. Only if no trap or trap is not "" */
2995 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2996 sigdelset(&G.blocked_set, sig);
3003 /* Our homegrown sig mask is saner to work with :) */
3004 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
3006 /* Resetting all traps to default except empty ones */
3007 mask = G.non_DFL_mask;
3008 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
3009 if (!G.traps[sig] || !G.traps[sig][0])
3012 G.traps[sig] = NULL;
3013 /* There is no signal for 0 (EXIT) */
3016 /* There was a trap handler, we just removed it.
3017 * But if sig still has non-DFL handling,
3018 * we should not unblock the sig. */
3021 sigdelset(&G.blocked_set, sig);
3023 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
3028 static void re_execute_shell(char ***to_free, const char *s,
3029 char *g_argv0, char **g_argv,
3030 char **builtin_argv) NORETURN;
3031 static void re_execute_shell(char ***to_free, const char *s,
3032 char *g_argv0, char **g_argv,
3033 char **builtin_argv)
3035 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
3036 /* delims + 2 * (number of bytes in printed hex numbers) */
3037 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
3038 char *heredoc_argv[4];
3039 struct variable *cur;
3040 # if ENABLE_HUSH_FUNCTIONS
3041 struct function *funcp;
3045 unsigned long long empty_trap_mask;
3047 if (!g_argv0) { /* heredoc */
3048 argv = heredoc_argv;
3049 argv[0] = (char *) G.argv0_for_re_execing;
3050 argv[1] = (char *) "-<";
3051 argv[2] = (char *) s;
3053 pp = &argv[3]; /* used as pointer to empty environment */
3059 if (pp) while (*pp++)
3062 empty_trap_mask = 0;
3065 for (sig = 1; sig < NSIG; sig++) {
3066 if (G.traps[sig] && !G.traps[sig][0])
3067 empty_trap_mask |= 1LL << sig;
3071 sprintf(param_buf, NOMMU_HACK_FMT
3072 , (unsigned) G.root_pid
3073 , (unsigned) G.root_ppid
3074 , (unsigned) G.last_bg_pid
3075 , (unsigned) G.last_exitcode
3078 IF_HUSH_LOOPS(, G.depth_of_loop)
3080 # undef NOMMU_HACK_FMT
3081 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3082 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3085 for (cur = G.top_var; cur; cur = cur->next) {
3086 if (!cur->flg_export || cur->flg_read_only)
3089 # if ENABLE_HUSH_FUNCTIONS
3090 for (funcp = G.top_func; funcp; funcp = funcp->next)
3096 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3097 *pp++ = (char *) G.argv0_for_re_execing;
3099 for (cur = G.top_var; cur; cur = cur->next) {
3100 if (cur->varstr == hush_version_str)
3102 if (cur->flg_read_only) {
3103 *pp++ = (char *) "-R";
3104 *pp++ = cur->varstr;
3105 } else if (!cur->flg_export) {
3106 *pp++ = (char *) "-V";
3107 *pp++ = cur->varstr;
3110 # if ENABLE_HUSH_FUNCTIONS
3111 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3112 *pp++ = (char *) "-F";
3113 *pp++ = funcp->name;
3114 *pp++ = funcp->body_as_string;
3117 /* We can pass activated traps here. Say, -Tnn:trap_string
3119 * However, POSIX says that subshells reset signals with traps
3121 * I tested bash-3.2 and it not only does that with true subshells
3122 * of the form ( list ), but with any forked children shells.
3123 * I set trap "echo W" WINCH; and then tried:
3125 * { echo 1; sleep 20; echo 2; } &
3126 * while true; do echo 1; sleep 20; echo 2; break; done &
3127 * true | { echo 1; sleep 20; echo 2; } | cat
3129 * In all these cases sending SIGWINCH to the child shell
3130 * did not run the trap. If I add trap "echo V" WINCH;
3131 * _inside_ group (just before echo 1), it works.
3133 * I conclude it means we don't need to pass active traps here.
3134 * Even if we would use signal handlers instead of signal masking
3135 * in order to implement trap handling,
3136 * exec syscall below resets signals to SIG_DFL for us.
3138 *pp++ = (char *) "-c";
3141 while (*++builtin_argv)
3142 *pp++ = *builtin_argv;
3143 *pp++ = (char *) "";
3148 /* *pp = NULL; - is already there */
3152 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3153 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3154 execve(bb_busybox_exec_path, argv, pp);
3155 /* Fallback. Useful for init=/bin/hush usage etc */
3156 if (argv[0][0] == '/')
3157 execve(argv[0], argv, pp);
3158 xfunc_error_retval = 127;
3159 bb_error_msg_and_die("can't re-execute the shell");
3161 #endif /* !BB_MMU */
3164 static void setup_heredoc(struct redir_struct *redir)
3166 struct fd_pair pair;
3169 /* the _body_ of heredoc (misleading field name) */
3170 const char *heredoc = redir->rd_filename;
3177 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3178 expanded = expand_pseudo_dquoted(heredoc);
3182 len = strlen(heredoc);
3184 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3186 xmove_fd(pair.rd, redir->rd_fd);
3188 /* Try writing without forking. Newer kernels have
3189 * dynamically growing pipes. Must use non-blocking write! */
3192 written = write(pair.wr, heredoc, len);
3203 ndelay_off(pair.wr);
3205 /* Okay, pipe buffer was not big enough */
3206 /* Note: we must not create a stray child (bastard? :)
3207 * for the unsuspecting parent process. Child creates a grandchild
3208 * and exits before parent execs the process which consumes heredoc
3209 * (that exec happens after we return from this function) */
3215 bb_perror_msg_and_die("vfork");
3218 disable_restore_tty_pgrp_on_exit();
3219 pid = BB_MMU ? fork() : vfork();
3221 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3225 close(redir->rd_fd); /* read side of the pipe */
3227 full_write(pair.wr, heredoc, len); /* may loop or block */
3230 /* Delegate blocking writes to another process */
3231 xmove_fd(pair.wr, STDOUT_FILENO);
3232 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3236 #if ENABLE_HUSH_FAST
3238 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3240 enable_restore_tty_pgrp_on_exit();
3246 wait(NULL); /* wait till child has died */
3249 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3250 * and stderr if they are redirected. */
3251 static int setup_redirects(struct command *prog, int squirrel[])
3254 struct redir_struct *redir;
3256 for (redir = prog->redirects; redir; redir = redir->next) {
3257 if (redir->rd_type == REDIRECT_HEREDOC2) {
3258 /* rd_fd<<HERE case */
3259 if (squirrel && redir->rd_fd < 3
3260 && squirrel[redir->rd_fd] < 0
3262 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3264 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3266 debug_printf_parse("set heredoc '%s'\n",
3267 redir->rd_filename);
3268 setup_heredoc(redir);
3272 if (redir->rd_dup == REDIRFD_TO_FILE) {
3273 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3275 if (redir->rd_filename == NULL) {
3276 /* Something went wrong in the parse.
3277 * Pretend it didn't happen */
3278 bb_error_msg("bug in redirect parse");
3281 mode = redir_table[redir->rd_type].mode;
3282 p = expand_string_to_string(redir->rd_filename);
3283 openfd = open_or_warn(p, mode);
3286 /* this could get lost if stderr has been redirected, but
3287 * bash and ash both lose it as well (though zsh doesn't!) */
3288 //what the above comment tries to say?
3292 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3293 openfd = redir->rd_dup;
3296 if (openfd != redir->rd_fd) {
3297 if (squirrel && redir->rd_fd < 3
3298 && squirrel[redir->rd_fd] < 0
3300 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3302 if (openfd == REDIRFD_CLOSE) {
3303 /* "n>-" means "close me" */
3304 close(redir->rd_fd);
3306 xdup2(openfd, redir->rd_fd);
3307 if (redir->rd_dup == REDIRFD_TO_FILE)
3315 static void restore_redirects(int squirrel[])
3318 for (i = 0; i < 3; i++) {
3321 /* We simply die on error */
3328 static void free_pipe_list(struct pipe *head);
3330 /* Return code is the exit status of the pipe */
3331 static void free_pipe(struct pipe *pi)
3334 struct command *command;
3335 struct redir_struct *r, *rnext;
3338 if (pi->stopped_cmds > 0) /* why? */
3340 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3341 for (i = 0; i < pi->num_cmds; i++) {
3342 command = &pi->cmds[i];
3343 debug_printf_clean(" command %d:\n", i);
3344 if (command->argv) {
3345 for (a = 0, p = command->argv; *p; a++, p++) {
3346 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3348 free_strings(command->argv);
3349 command->argv = NULL;
3351 /* not "else if": on syntax error, we may have both! */
3352 if (command->group) {
3353 debug_printf_clean(" begin group (cmd_type:%d)\n",
3355 free_pipe_list(command->group);
3356 debug_printf_clean(" end group\n");
3357 command->group = NULL;
3359 /* else is crucial here.
3360 * If group != NULL, child_func is meaningless */
3361 #if ENABLE_HUSH_FUNCTIONS
3362 else if (command->child_func) {
3363 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3364 command->child_func->parent_cmd = NULL;
3368 free(command->group_as_string);
3369 command->group_as_string = NULL;
3371 for (r = command->redirects; r; r = rnext) {
3372 debug_printf_clean(" redirect %d%s",
3373 r->rd_fd, redir_table[r->rd_type].descrip);
3374 /* guard against the case >$FOO, where foo is unset or blank */
3375 if (r->rd_filename) {
3376 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3377 free(r->rd_filename);
3378 r->rd_filename = NULL;
3380 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3384 command->redirects = NULL;
3386 free(pi->cmds); /* children are an array, they get freed all at once */
3394 static void free_pipe_list(struct pipe *head)
3396 struct pipe *pi, *next;
3398 for (pi = head; pi; pi = next) {
3400 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3403 debug_printf_clean("pipe followup code %d\n", pi->followup);
3405 /*pi->next = NULL;*/
3411 static int run_list(struct pipe *pi);
3413 #define parse_stream(pstring, input, end_trigger) \
3414 parse_stream(input, end_trigger)
3416 static struct pipe *parse_stream(char **pstring,
3417 struct in_str *input,
3419 static void parse_and_run_string(const char *s);
3422 static char *find_in_path(const char *arg)
3425 const char *PATH = get_local_var_value("PATH");
3431 const char *end = strchrnul(PATH, ':');
3432 int sz = end - PATH; /* must be int! */
3436 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3438 /* We have xxx::yyyy in $PATH,
3439 * it means "use current dir" */
3442 if (access(ret, F_OK) == 0)
3455 static const struct built_in_command* find_builtin_helper(const char *name,
3456 const struct built_in_command *x,
3457 const struct built_in_command *end)
3460 if (strcmp(name, x->b_cmd) != 0) {
3464 debug_printf_exec("found builtin '%s'\n", name);
3469 static const struct built_in_command* find_builtin1(const char *name)
3471 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3473 static const struct built_in_command* find_builtin(const char *name)
3475 const struct built_in_command *x = find_builtin1(name);
3478 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3481 #if ENABLE_HUSH_FUNCTIONS
3482 static struct function **find_function_slot(const char *name)
3484 struct function **funcpp = &G.top_func;
3486 if (strcmp(name, (*funcpp)->name) == 0) {
3489 funcpp = &(*funcpp)->next;
3494 static const struct function *find_function(const char *name)
3496 const struct function *funcp = *find_function_slot(name);
3498 debug_printf_exec("found function '%s'\n", name);
3502 /* Note: takes ownership on name ptr */
3503 static struct function *new_function(char *name)
3505 struct function **funcpp = find_function_slot(name);
3506 struct function *funcp = *funcpp;
3508 if (funcp != NULL) {
3509 struct command *cmd = funcp->parent_cmd;
3510 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3512 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3514 /* Note: if !funcp->body, do not free body_as_string!
3515 * This is a special case of "-F name body" function:
3516 * body_as_string was not malloced! */
3518 free_pipe_list(funcp->body);
3520 free(funcp->body_as_string);
3524 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3525 cmd->argv[0] = funcp->name;
3526 cmd->group = funcp->body;
3528 cmd->group_as_string = funcp->body_as_string;
3532 debug_printf_exec("remembering new function '%s'\n", name);
3533 funcp = *funcpp = xzalloc(sizeof(*funcp));
3534 /*funcp->next = NULL;*/
3541 static void unset_func(const char *name)
3543 struct function **funcpp = find_function_slot(name);
3544 struct function *funcp = *funcpp;
3546 if (funcp != NULL) {
3547 debug_printf_exec("freeing function '%s'\n", funcp->name);
3548 *funcpp = funcp->next;
3549 /* funcp is unlinked now, deleting it.
3550 * Note: if !funcp->body, the function was created by
3551 * "-F name body", do not free ->body_as_string
3552 * and ->name as they were not malloced. */
3554 free_pipe_list(funcp->body);
3557 free(funcp->body_as_string);
3565 #define exec_function(to_free, funcp, argv) \
3566 exec_function(funcp, argv)
3568 static void exec_function(char ***to_free,
3569 const struct function *funcp,
3570 char **argv) NORETURN;
3571 static void exec_function(char ***to_free,
3572 const struct function *funcp,
3578 argv[0] = G.global_argv[0];
3579 G.global_argv = argv;
3583 /* On MMU, funcp->body is always non-NULL */
3584 n = run_list(funcp->body);
3588 re_execute_shell(to_free,
3589 funcp->body_as_string,
3596 static int run_function(const struct function *funcp, char **argv)
3602 save_and_replace_G_args(&sv, argv);
3604 /* "we are in function, ok to use return" */
3605 sv_flg = G.flag_return_in_progress;
3606 G.flag_return_in_progress = -1;
3607 # if ENABLE_HUSH_LOCAL
3608 G.func_nest_level++;
3611 /* On MMU, funcp->body is always non-NULL */
3614 /* Function defined by -F */
3615 parse_and_run_string(funcp->body_as_string);
3616 rc = G.last_exitcode;
3620 rc = run_list(funcp->body);
3623 # if ENABLE_HUSH_LOCAL
3625 struct variable *var;
3626 struct variable **var_pp;
3628 var_pp = &G.top_var;
3629 while ((var = *var_pp) != NULL) {
3630 if (var->func_nest_level < G.func_nest_level) {
3631 var_pp = &var->next;
3635 if (var->flg_export)
3636 bb_unsetenv(var->varstr);
3637 /* Remove from global list */
3638 *var_pp = var->next;
3644 G.func_nest_level--;
3647 G.flag_return_in_progress = sv_flg;
3649 restore_G_args(&sv, argv);
3653 #endif /* ENABLE_HUSH_FUNCTIONS */
3657 #define exec_builtin(to_free, x, argv) \
3658 exec_builtin(x, argv)
3660 #define exec_builtin(to_free, x, argv) \
3661 exec_builtin(to_free, argv)
3663 static void exec_builtin(char ***to_free,
3664 const struct built_in_command *x,
3665 char **argv) NORETURN;
3666 static void exec_builtin(char ***to_free,
3667 const struct built_in_command *x,
3671 int rcode = x->b_function(argv);
3675 /* On NOMMU, we must never block!
3676 * Example: { sleep 99 | read line; } & echo Ok
3678 re_execute_shell(to_free,
3687 static void execvp_or_die(char **argv) NORETURN;
3688 static void execvp_or_die(char **argv)
3690 debug_printf_exec("execing '%s'\n", argv[0]);
3691 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3692 execvp(argv[0], argv);
3693 bb_perror_msg("can't execute '%s'", argv[0]);
3694 _exit(127); /* bash compat */
3698 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3699 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3700 #define pseudo_exec(nommu_save, command, argv_expanded) \
3701 pseudo_exec(command, argv_expanded)
3704 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3706 * Don't exit() here. If you don't exec, use _exit instead.
3707 * The at_exit handlers apparently confuse the calling process,
3708 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3709 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3710 char **argv, int assignment_cnt,
3711 char **argv_expanded) NORETURN;
3712 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3713 char **argv, int assignment_cnt,
3714 char **argv_expanded)
3718 /* Case when we are here: ... | var=val | ... */
3719 if (!argv[assignment_cnt])
3720 _exit(EXIT_SUCCESS);
3722 new_env = expand_assignments(argv, assignment_cnt);
3724 set_vars_and_save_old(new_env);
3725 free(new_env); /* optional */
3726 /* we can also destroy set_vars_and_save_old's return value,
3729 nommu_save->new_env = new_env;
3730 nommu_save->old_vars = set_vars_and_save_old(new_env);
3732 if (argv_expanded) {
3733 argv = argv_expanded;
3735 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3737 nommu_save->argv = argv;
3741 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3742 if (strchr(argv[0], '/') != NULL)
3746 /* Check if the command matches any of the builtins.
3747 * Depending on context, this might be redundant. But it's
3748 * easier to waste a few CPU cycles than it is to figure out
3749 * if this is one of those cases.
3752 /* On NOMMU, it is more expensive to re-execute shell
3753 * just in order to run echo or test builtin.
3754 * It's better to skip it here and run corresponding
3755 * non-builtin later. */
3756 const struct built_in_command *x;
3757 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3759 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3762 #if ENABLE_HUSH_FUNCTIONS
3763 /* Check if the command matches any functions */
3765 const struct function *funcp = find_function(argv[0]);
3767 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3772 #if ENABLE_FEATURE_SH_STANDALONE
3773 /* Check if the command matches any busybox applets */
3775 int a = find_applet_by_name(argv[0]);
3777 # if BB_MMU /* see above why on NOMMU it is not allowed */
3778 if (APPLET_IS_NOEXEC(a)) {
3779 debug_printf_exec("running applet '%s'\n", argv[0]);
3780 run_applet_no_and_exit(a, argv);
3783 /* Re-exec ourselves */
3784 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3785 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3786 execv(bb_busybox_exec_path, argv);
3787 /* If they called chroot or otherwise made the binary no longer
3788 * executable, fall through */
3793 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3796 execvp_or_die(argv);
3799 /* Called after [v]fork() in run_pipe
3801 static void pseudo_exec(nommu_save_t *nommu_save,
3802 struct command *command,
3803 char **argv_expanded) NORETURN;
3804 static void pseudo_exec(nommu_save_t *nommu_save,
3805 struct command *command,
3806 char **argv_expanded)
3808 if (command->argv) {
3809 pseudo_exec_argv(nommu_save, command->argv,
3810 command->assignment_cnt, argv_expanded);
3813 if (command->group) {
3814 /* Cases when we are here:
3817 * ... | ( list ) | ...
3818 * ... | { list } | ...
3822 debug_printf_exec("pseudo_exec: run_list\n");
3823 reset_traps_to_defaults();
3824 rcode = run_list(command->group);
3825 /* OK to leak memory by not calling free_pipe_list,
3826 * since this process is about to exit */
3829 re_execute_shell(&nommu_save->argv_from_re_execing,
3830 command->group_as_string,
3837 /* Case when we are here: ... | >file */
3838 debug_printf_exec("pseudo_exec'ed null command\n");
3839 _exit(EXIT_SUCCESS);
3843 static const char *get_cmdtext(struct pipe *pi)
3849 /* This is subtle. ->cmdtext is created only on first backgrounding.
3850 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3851 * On subsequent bg argv is trashed, but we won't use it */
3854 argv = pi->cmds[0].argv;
3855 if (!argv || !argv[0]) {
3856 pi->cmdtext = xzalloc(1);
3862 len += strlen(*argv) + 1;
3866 argv = pi->cmds[0].argv;
3868 len = strlen(*argv);
3869 memcpy(p, *argv, len);
3877 static void insert_bg_job(struct pipe *pi)
3879 struct pipe *job, **jobp;
3882 /* Linear search for the ID of the job to use */
3884 for (job = G.job_list; job; job = job->next)
3885 if (job->jobid >= pi->jobid)
3886 pi->jobid = job->jobid + 1;
3888 /* Add job to the list of running jobs */
3890 while ((job = *jobp) != NULL)
3892 job = *jobp = xmalloc(sizeof(*job));
3894 *job = *pi; /* physical copy */
3896 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3897 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3898 for (i = 0; i < pi->num_cmds; i++) {
3899 job->cmds[i].pid = pi->cmds[i].pid;
3900 /* all other fields are not used and stay zero */
3902 job->cmdtext = xstrdup(get_cmdtext(pi));
3904 if (G_interactive_fd)
3905 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3906 /* Last command's pid goes to $! */
3907 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3908 G.last_jobid = job->jobid;
3911 static void remove_bg_job(struct pipe *pi)
3913 struct pipe *prev_pipe;
3915 if (pi == G.job_list) {
3916 G.job_list = pi->next;
3918 prev_pipe = G.job_list;
3919 while (prev_pipe->next != pi)
3920 prev_pipe = prev_pipe->next;
3921 prev_pipe->next = pi->next;
3924 G.last_jobid = G.job_list->jobid;
3929 /* Remove a backgrounded job */
3930 static void delete_finished_bg_job(struct pipe *pi)
3933 pi->stopped_cmds = 0;
3939 /* Check to see if any processes have exited -- if they
3940 * have, figure out why and see if a job has completed */
3941 static int checkjobs(struct pipe* fg_pipe)
3951 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3953 attributes = WUNTRACED;
3954 if (fg_pipe == NULL)
3955 attributes |= WNOHANG;
3958 #if ENABLE_HUSH_FAST
3959 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3960 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3961 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3962 /* There was neither fork nor SIGCHLD since last waitpid */
3963 /* Avoid doing waitpid syscall if possible */
3964 if (!G.we_have_children) {
3968 if (fg_pipe == NULL) { /* is WNOHANG set? */
3969 /* We have children, but they did not exit
3970 * or stop yet (we saw no SIGCHLD) */
3973 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3977 /* Do we do this right?
3978 * bash-3.00# sleep 20 | false
3980 * [3]+ Stopped sleep 20 | false
3981 * bash-3.00# echo $?
3982 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3983 * [hush 1.14.0: yes we do it right]
3990 #if ENABLE_HUSH_FAST
3991 i = G.count_SIGCHLD;
3993 childpid = waitpid(-1, &status, attributes);
3994 if (childpid <= 0) {
3995 if (childpid && errno != ECHILD)
3996 bb_perror_msg("waitpid");
3997 #if ENABLE_HUSH_FAST
3998 else { /* Until next SIGCHLD, waitpid's are useless */
3999 G.we_have_children = (childpid == 0);
4000 G.handled_SIGCHLD = i;
4001 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4006 dead = WIFEXITED(status) || WIFSIGNALED(status);
4009 if (WIFSTOPPED(status))
4010 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
4011 childpid, WSTOPSIG(status), WEXITSTATUS(status));
4012 if (WIFSIGNALED(status))
4013 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
4014 childpid, WTERMSIG(status), WEXITSTATUS(status));
4015 if (WIFEXITED(status))
4016 debug_printf_jobs("pid %d exited, exitcode %d\n",
4017 childpid, WEXITSTATUS(status));
4019 /* Were we asked to wait for fg pipe? */
4021 for (i = 0; i < fg_pipe->num_cmds; i++) {
4022 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
4023 if (fg_pipe->cmds[i].pid != childpid)
4026 fg_pipe->cmds[i].pid = 0;
4027 fg_pipe->alive_cmds--;
4028 if (i == fg_pipe->num_cmds - 1) {
4029 /* last process gives overall exitstatus */
4030 rcode = WEXITSTATUS(status);
4031 /* bash prints killer signal's name for *last*
4032 * process in pipe (prints just newline for SIGINT).
4033 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
4035 if (WIFSIGNALED(status)) {
4036 int sig = WTERMSIG(status);
4037 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
4038 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
4039 * Maybe we need to use sig | 128? */
4042 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
4045 fg_pipe->cmds[i].is_stopped = 1;
4046 fg_pipe->stopped_cmds++;
4048 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
4049 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
4050 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
4051 /* All processes in fg pipe have exited or stopped */
4052 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4053 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4054 * and "killall -STOP cat" */
4055 if (G_interactive_fd) {
4057 if (fg_pipe->alive_cmds)
4058 insert_bg_job(fg_pipe);
4062 if (!fg_pipe->alive_cmds)
4065 /* There are still running processes in the fg pipe */
4066 goto wait_more; /* do waitpid again */
4068 /* it wasnt fg_pipe, look for process in bg pipes */
4072 /* We asked to wait for bg or orphaned children */
4073 /* No need to remember exitcode in this case */
4074 for (pi = G.job_list; pi; pi = pi->next) {
4075 for (i = 0; i < pi->num_cmds; i++) {
4076 if (pi->cmds[i].pid == childpid)
4077 goto found_pi_and_prognum;
4080 /* Happens when shell is used as init process (init=/bin/sh) */
4081 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4082 continue; /* do waitpid again */
4084 found_pi_and_prognum:
4087 pi->cmds[i].pid = 0;
4089 if (!pi->alive_cmds) {
4090 if (G_interactive_fd)
4091 printf(JOB_STATUS_FORMAT, pi->jobid,
4092 "Done", pi->cmdtext);
4093 delete_finished_bg_job(pi);
4097 pi->cmds[i].is_stopped = 1;
4101 } /* while (waitpid succeeds)... */
4107 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4110 int rcode = checkjobs(fg_pipe);
4111 if (G_saved_tty_pgrp) {
4112 /* Job finished, move the shell to the foreground */
4113 p = getpgrp(); /* our process group id */
4114 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4115 tcsetpgrp(G_interactive_fd, p);
4121 /* Start all the jobs, but don't wait for anything to finish.
4124 * Return code is normally -1, when the caller has to wait for children
4125 * to finish to determine the exit status of the pipe. If the pipe
4126 * is a simple builtin command, however, the action is done by the
4127 * time run_pipe returns, and the exit code is provided as the
4130 * Returns -1 only if started some children. IOW: we have to
4131 * mask out retvals of builtins etc with 0xff!
4133 * The only case when we do not need to [v]fork is when the pipe
4134 * is single, non-backgrounded, non-subshell command. Examples:
4135 * cmd ; ... { list } ; ...
4136 * cmd && ... { list } && ...
4137 * cmd || ... { list } || ...
4138 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4139 * or (if SH_STANDALONE) an applet, and we can run the { list }
4140 * with run_list. If it isn't one of these, we fork and exec cmd.
4142 * Cases when we must fork:
4143 * non-single: cmd | cmd
4144 * backgrounded: cmd & { list } &
4145 * subshell: ( list ) [&]
4147 static NOINLINE int run_pipe(struct pipe *pi)
4149 static const char *const null_ptr = NULL;
4152 struct command *command;
4153 char **argv_expanded;
4156 /* it is not always needed, but we aim to smaller code */
4157 int squirrel[] = { -1, -1, -1 };
4160 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4163 IF_HUSH_JOB(pi->pgrp = -1;)
4164 pi->stopped_cmds = 0;
4165 command = &(pi->cmds[0]);
4166 argv_expanded = NULL;
4168 if (pi->num_cmds != 1
4169 || pi->followup == PIPE_BG
4170 || command->cmd_type == CMD_SUBSHELL
4177 debug_printf_exec(": group:%p argv:'%s'\n",
4178 command->group, command->argv ? command->argv[0] : "NONE");
4180 if (command->group) {
4181 #if ENABLE_HUSH_FUNCTIONS
4182 if (command->cmd_type == CMD_FUNCDEF) {
4183 /* "executing" func () { list } */
4184 struct function *funcp;
4186 funcp = new_function(command->argv[0]);
4187 /* funcp->name is already set to argv[0] */
4188 funcp->body = command->group;
4190 funcp->body_as_string = command->group_as_string;
4191 command->group_as_string = NULL;
4193 command->group = NULL;
4194 command->argv[0] = NULL;
4195 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4196 funcp->parent_cmd = command;
4197 command->child_func = funcp;
4199 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4201 return EXIT_SUCCESS;
4205 debug_printf("non-subshell group\n");
4206 rcode = 1; /* exitcode if redir failed */
4207 if (setup_redirects(command, squirrel) == 0) {
4208 debug_printf_exec(": run_list\n");
4209 rcode = run_list(command->group) & 0xff;
4211 restore_redirects(squirrel);
4212 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4214 debug_printf_exec("run_pipe: return %d\n", rcode);
4218 argv = command->argv ? command->argv : (char **) &null_ptr;
4220 const struct built_in_command *x;
4221 #if ENABLE_HUSH_FUNCTIONS
4222 const struct function *funcp;
4226 char **new_env = NULL;
4227 struct variable *old_vars = NULL;
4229 if (argv[command->assignment_cnt] == NULL) {
4230 /* Assignments, but no command */
4231 /* Ensure redirects take effect (that is, create files).
4232 * Try "a=t >file": */
4233 rcode = setup_redirects(command, squirrel);
4234 restore_redirects(squirrel);
4235 /* Set shell variables */
4237 p = expand_string_to_string(*argv);
4238 debug_printf_exec("set shell var:'%s'->'%s'\n",
4240 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4243 /* Redirect error sets $? to 1. Othervise,
4244 * if evaluating assignment value set $?, retain it.
4245 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4247 rcode = G.last_exitcode;
4248 /* Do we need to flag set_local_var() errors?
4249 * "assignment to readonly var" and "putenv error"
4251 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4253 debug_printf_exec("run_pipe: return %d\n", rcode);
4257 /* Expand the rest into (possibly) many strings each */
4259 #if ENABLE_HUSH_BASH_COMPAT
4260 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4261 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4264 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4265 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4266 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4271 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4274 /* if someone gives us an empty string: `cmd with empty output` */
4275 if (!argv_expanded[0]) {
4276 free(argv_expanded);
4278 return G.last_exitcode;
4281 x = find_builtin(argv_expanded[0]);
4282 #if ENABLE_HUSH_FUNCTIONS
4285 funcp = find_function(argv_expanded[0]);
4289 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4290 debug_printf("exec with redirects only\n");
4291 rcode = setup_redirects(command, NULL);
4292 goto clean_up_and_ret1;
4295 /* setup_redirects acts on file descriptors, not FILEs.
4296 * This is perfect for work that comes after exec().
4297 * Is it really safe for inline use? Experimentally,
4298 * things seem to work. */
4299 rcode = setup_redirects(command, squirrel);
4301 new_env = expand_assignments(argv, command->assignment_cnt);
4302 old_vars = set_vars_and_save_old(new_env);
4304 debug_printf_exec(": builtin '%s' '%s'...\n",
4305 x->b_cmd, argv_expanded[1]);
4306 rcode = x->b_function(argv_expanded) & 0xff;
4309 #if ENABLE_HUSH_FUNCTIONS
4311 # if ENABLE_HUSH_LOCAL
4312 struct variable **sv;
4313 sv = G.shadowed_vars_pp;
4314 G.shadowed_vars_pp = &old_vars;
4316 debug_printf_exec(": function '%s' '%s'...\n",
4317 funcp->name, argv_expanded[1]);
4318 rcode = run_function(funcp, argv_expanded) & 0xff;
4319 # if ENABLE_HUSH_LOCAL
4320 G.shadowed_vars_pp = sv;
4325 #if ENABLE_FEATURE_SH_STANDALONE
4328 restore_redirects(squirrel);
4329 unset_vars(new_env);
4332 free(argv_expanded);
4333 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4335 debug_printf_exec("run_pipe return %d\n", rcode);
4339 #if ENABLE_FEATURE_SH_STANDALONE
4340 i = find_applet_by_name(argv_expanded[0]);
4341 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4342 rcode = setup_redirects(command, squirrel);
4344 new_env = expand_assignments(argv, command->assignment_cnt);
4345 old_vars = set_vars_and_save_old(new_env);
4346 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4347 argv_expanded[0], argv_expanded[1]);
4348 rcode = run_nofork_applet(i, argv_expanded);
4350 goto clean_up_and_ret;
4353 /* It is neither builtin nor applet. We must fork. */
4357 /* NB: argv_expanded may already be created, and that
4358 * might include `cmd` runs! Do not rerun it! We *must*
4359 * use argv_expanded if it's non-NULL */
4361 /* Going to fork a child per each pipe member */
4365 for (i = 0; i < pi->num_cmds; i++) {
4366 struct fd_pair pipefds;
4368 volatile nommu_save_t nommu_save;
4369 nommu_save.new_env = NULL;
4370 nommu_save.old_vars = NULL;
4371 nommu_save.argv = NULL;
4372 nommu_save.argv_from_re_execing = NULL;
4374 command = &(pi->cmds[i]);
4375 if (command->argv) {
4376 debug_printf_exec(": pipe member '%s' '%s'...\n",
4377 command->argv[0], command->argv[1]);
4379 debug_printf_exec(": pipe member with no argv\n");
4382 /* pipes are inserted between pairs of commands */
4385 if ((i + 1) < pi->num_cmds)
4386 xpiped_pair(pipefds);
4388 command->pid = BB_MMU ? fork() : vfork();
4389 if (!command->pid) { /* child */
4391 disable_restore_tty_pgrp_on_exit();
4392 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4394 /* Every child adds itself to new process group
4395 * with pgid == pid_of_first_child_in_pipe */
4396 if (G.run_list_level == 1 && G_interactive_fd) {
4399 if (pgrp < 0) /* true for 1st process only */
4401 if (setpgid(0, pgrp) == 0
4402 && pi->followup != PIPE_BG
4403 && G_saved_tty_pgrp /* we have ctty */
4405 /* We do it in *every* child, not just first,
4407 tcsetpgrp(G_interactive_fd, pgrp);
4411 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4412 /* 1st cmd in backgrounded pipe
4413 * should have its stdin /dev/null'ed */
4415 if (open(bb_dev_null, O_RDONLY))
4416 xopen("/", O_RDONLY);
4418 xmove_fd(nextin, 0);
4420 xmove_fd(pipefds.wr, 1);
4423 /* Like bash, explicit redirects override pipes,
4424 * and the pipe fd is available for dup'ing. */
4425 if (setup_redirects(command, NULL))
4428 /* Restore default handlers just prior to exec */
4429 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4431 /* Stores to nommu_save list of env vars putenv'ed
4432 * (NOMMU, on MMU we don't need that) */
4433 /* cast away volatility... */
4434 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4435 /* pseudo_exec() does not return */
4438 /* parent or error */
4439 #if ENABLE_HUSH_FAST
4441 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4443 enable_restore_tty_pgrp_on_exit();
4445 /* Clean up after vforked child */
4446 free(nommu_save.argv);
4447 free(nommu_save.argv_from_re_execing);
4448 unset_vars(nommu_save.new_env);
4449 add_vars(nommu_save.old_vars);
4451 free(argv_expanded);
4452 argv_expanded = NULL;
4453 if (command->pid < 0) { /* [v]fork failed */
4454 /* Clearly indicate, was it fork or vfork */
4455 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4459 /* Second and next children need to know pid of first one */
4461 pi->pgrp = command->pid;
4467 if ((i + 1) < pi->num_cmds)
4469 /* Pass read (output) pipe end to next iteration */
4470 nextin = pipefds.rd;
4473 if (!pi->alive_cmds) {
4475 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4480 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4484 #ifndef debug_print_tree
4485 static void debug_print_tree(struct pipe *pi, int lvl)
4487 static const char *const PIPE[] = {
4493 static const char *RES[] = {
4494 [RES_NONE ] = "NONE" ,
4497 [RES_THEN ] = "THEN" ,
4498 [RES_ELIF ] = "ELIF" ,
4499 [RES_ELSE ] = "ELSE" ,
4502 # if ENABLE_HUSH_LOOPS
4503 [RES_FOR ] = "FOR" ,
4504 [RES_WHILE] = "WHILE",
4505 [RES_UNTIL] = "UNTIL",
4507 [RES_DONE ] = "DONE" ,
4509 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4512 # if ENABLE_HUSH_CASE
4513 [RES_CASE ] = "CASE" ,
4514 [RES_CASE_IN ] = "CASE_IN" ,
4515 [RES_MATCH] = "MATCH",
4516 [RES_CASE_BODY] = "CASE_BODY",
4517 [RES_ESAC ] = "ESAC" ,
4519 [RES_XXXX ] = "XXXX" ,
4520 [RES_SNTX ] = "SNTX" ,
4522 static const char *const CMDTYPE[] = {
4526 # if ENABLE_HUSH_FUNCTIONS
4535 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4536 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4538 while (prn < pi->num_cmds) {
4539 struct command *command = &pi->cmds[prn];
4540 char **argv = command->argv;
4542 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4544 command->assignment_cnt);
4545 if (command->group) {
4546 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4547 CMDTYPE[command->cmd_type],
4550 , " group_as_string:", command->group_as_string
4555 debug_print_tree(command->group, lvl+1);
4559 if (argv) while (*argv) {
4560 fprintf(stderr, " '%s'", *argv);
4563 fprintf(stderr, "\n");
4570 #endif /* debug_print_tree */
4572 /* NB: called by pseudo_exec, and therefore must not modify any
4573 * global data until exec/_exit (we can be a child after vfork!) */
4574 static int run_list(struct pipe *pi)
4576 #if ENABLE_HUSH_CASE
4577 char *case_word = NULL;
4579 #if ENABLE_HUSH_LOOPS
4580 struct pipe *loop_top = NULL;
4581 char **for_lcur = NULL;
4582 char **for_list = NULL;
4584 smallint last_followup;
4586 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4587 smalluint cond_code = 0;
4589 enum { cond_code = 0 };
4592 smallint rword; /* enum reserved_style */
4593 smallint last_rword; /* ditto */
4596 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4599 #if ENABLE_HUSH_LOOPS
4600 /* Check syntax for "for" */
4601 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4602 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4604 /* current word is FOR or IN (BOLD in comments below) */
4605 if (cpipe->next == NULL) {
4606 syntax_error("malformed for");
4608 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4611 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4612 if (cpipe->next->res_word == RES_DO)
4614 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4615 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4616 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4618 syntax_error("malformed for");
4620 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4626 /* Past this point, all code paths should jump to ret: label
4627 * in order to return, no direct "return" statements please.
4628 * This helps to ensure that no memory is leaked. */
4636 last_rword = RES_XXXX;
4638 last_followup = PIPE_SEQ;
4639 rcode = G.last_exitcode;
4641 /* Go through list of pipes, (maybe) executing them. */
4642 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4646 IF_HAS_KEYWORDS(rword = pi->res_word;)
4647 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4648 rword, cond_code, last_rword);
4649 #if ENABLE_HUSH_LOOPS
4650 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4651 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4653 /* start of a loop: remember where loop starts */
4658 /* Still in the same "if...", "then..." or "do..." branch? */
4659 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4660 if ((rcode == 0 && last_followup == PIPE_OR)
4661 || (rcode != 0 && last_followup == PIPE_AND)
4663 /* It is "<true> || CMD" or "<false> && CMD"
4664 * and we should not execute CMD */
4665 debug_printf_exec("skipped cmd because of || or &&\n");
4666 last_followup = pi->followup;
4670 last_followup = pi->followup;
4671 IF_HAS_KEYWORDS(last_rword = rword;)
4674 if (rword == RES_THEN) {
4675 /* if false; then ... fi has exitcode 0! */
4676 G.last_exitcode = rcode = EXIT_SUCCESS;
4677 /* "if <false> THEN cmd": skip cmd */
4681 if (rword == RES_ELSE || rword == RES_ELIF) {
4682 /* "if <true> then ... ELSE/ELIF cmd":
4683 * skip cmd and all following ones */
4688 #if ENABLE_HUSH_LOOPS
4689 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4691 /* first loop through for */
4693 static const char encoded_dollar_at[] ALIGN1 = {
4694 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4695 }; /* encoded representation of "$@" */
4696 static const char *const encoded_dollar_at_argv[] = {
4697 encoded_dollar_at, NULL
4698 }; /* argv list with one element: "$@" */
4701 vals = (char**)encoded_dollar_at_argv;
4702 if (pi->next->res_word == RES_IN) {
4703 /* if no variable values after "in" we skip "for" */
4704 if (!pi->next->cmds[0].argv) {
4705 G.last_exitcode = rcode = EXIT_SUCCESS;
4706 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4709 vals = pi->next->cmds[0].argv;
4710 } /* else: "for var; do..." -> assume "$@" list */
4711 /* create list of variable values */
4712 debug_print_strings("for_list made from", vals);
4713 for_list = expand_strvec_to_strvec(vals);
4714 for_lcur = for_list;
4715 debug_print_strings("for_list", for_list);
4718 /* "for" loop is over, clean up */
4724 /* Insert next value from for_lcur */
4725 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4726 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4729 if (rword == RES_IN) {
4730 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4732 if (rword == RES_DONE) {
4733 continue; /* "done" has no cmds too */
4736 #if ENABLE_HUSH_CASE
4737 if (rword == RES_CASE) {
4738 case_word = expand_strvec_to_string(pi->cmds->argv);
4741 if (rword == RES_MATCH) {
4744 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4746 /* all prev words didn't match, does this one match? */
4747 argv = pi->cmds->argv;
4749 char *pattern = expand_string_to_string(*argv);
4750 /* TODO: which FNM_xxx flags to use? */
4751 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4753 if (cond_code == 0) { /* match! we will execute this branch */
4754 free(case_word); /* make future "word)" stop */
4762 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4764 continue; /* not matched yet, skip this pipe */
4767 /* Just pressing <enter> in shell should check for jobs.
4768 * OTOH, in non-interactive shell this is useless
4769 * and only leads to extra job checks */
4770 if (pi->num_cmds == 0) {
4771 if (G_interactive_fd)
4772 goto check_jobs_and_continue;
4776 /* After analyzing all keywords and conditions, we decided
4777 * to execute this pipe. NB: have to do checkjobs(NULL)
4778 * after run_pipe to collect any background children,
4779 * even if list execution is to be stopped. */
4780 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4783 #if ENABLE_HUSH_LOOPS
4784 G.flag_break_continue = 0;
4786 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4788 /* We ran a builtin, function, or group.
4789 * rcode is already known
4790 * and we don't need to wait for anything. */
4791 G.last_exitcode = rcode;
4792 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4793 check_and_run_traps(0);
4794 #if ENABLE_HUSH_LOOPS
4795 /* Was it "break" or "continue"? */
4796 if (G.flag_break_continue) {
4797 smallint fbc = G.flag_break_continue;
4798 /* We might fall into outer *loop*,
4799 * don't want to break it too */
4801 G.depth_break_continue--;
4802 if (G.depth_break_continue == 0)
4803 G.flag_break_continue = 0;
4804 /* else: e.g. "continue 2" should *break* once, *then* continue */
4805 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4806 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4807 goto check_jobs_and_break;
4808 /* "continue": simulate end of loop */
4813 #if ENABLE_HUSH_FUNCTIONS
4814 if (G.flag_return_in_progress == 1) {
4815 /* same as "goto check_jobs_and_break" */
4820 } else if (pi->followup == PIPE_BG) {
4821 /* What does bash do with attempts to background builtins? */
4822 /* even bash 3.2 doesn't do that well with nested bg:
4823 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4824 * I'm NOT treating inner &'s as jobs */
4825 check_and_run_traps(0);
4827 if (G.run_list_level == 1)
4830 G.last_exitcode = rcode = EXIT_SUCCESS;
4831 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4834 if (G.run_list_level == 1 && G_interactive_fd) {
4835 /* Waits for completion, then fg's main shell */
4836 rcode = checkjobs_and_fg_shell(pi);
4837 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4838 check_and_run_traps(0);
4841 { /* This one just waits for completion */
4842 rcode = checkjobs(pi);
4843 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4844 check_and_run_traps(0);
4846 G.last_exitcode = rcode;
4850 /* Analyze how result affects subsequent commands */
4852 if (rword == RES_IF || rword == RES_ELIF)
4855 #if ENABLE_HUSH_LOOPS
4856 /* Beware of "while false; true; do ..."! */
4857 if (pi->next && pi->next->res_word == RES_DO) {
4858 if (rword == RES_WHILE) {
4860 /* "while false; do...done" - exitcode 0 */
4861 G.last_exitcode = rcode = EXIT_SUCCESS;
4862 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4863 goto check_jobs_and_break;
4866 if (rword == RES_UNTIL) {
4868 debug_printf_exec(": until expr is true: breaking\n");
4869 check_jobs_and_break:
4877 check_jobs_and_continue:
4884 #if ENABLE_HUSH_LOOPS
4889 #if ENABLE_HUSH_CASE
4893 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4897 /* Select which version we will use */
4898 static int run_and_free_list(struct pipe *pi)
4901 debug_printf_exec("run_and_free_list entered\n");
4903 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4904 rcode = run_list(pi);
4906 /* free_pipe_list has the side effect of clearing memory.
4907 * In the long run that function can be merged with run_list,
4908 * but doing that now would hobble the debugging effort. */
4910 debug_printf_exec("run_and_free_list return %d\n", rcode);
4915 static struct pipe *new_pipe(void)
4918 pi = xzalloc(sizeof(struct pipe));
4919 /*pi->followup = 0; - deliberately invalid value */
4920 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4924 /* Command (member of a pipe) is complete, or we start a new pipe
4925 * if ctx->command is NULL.
4926 * No errors possible here.
4928 static int done_command(struct parse_context *ctx)
4930 /* The command is really already in the pipe structure, so
4931 * advance the pipe counter and make a new, null command. */
4932 struct pipe *pi = ctx->pipe;
4933 struct command *command = ctx->command;
4936 if (IS_NULL_CMD(command)) {
4937 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4941 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4942 //debug_print_tree(ctx->list_head, 20);
4944 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4947 /* Only real trickiness here is that the uncommitted
4948 * command structure is not counted in pi->num_cmds. */
4949 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4950 ctx->command = command = &pi->cmds[pi->num_cmds];
4952 memset(command, 0, sizeof(*command));
4953 return pi->num_cmds; /* used only for 0/nonzero check */
4956 static void done_pipe(struct parse_context *ctx, pipe_style type)
4960 debug_printf_parse("done_pipe entered, followup %d\n", type);
4961 /* Close previous command */
4962 not_null = done_command(ctx);
4963 ctx->pipe->followup = type;
4965 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4966 ctx->ctx_inverted = 0;
4967 ctx->pipe->res_word = ctx->ctx_res_w;
4970 /* Without this check, even just <enter> on command line generates
4971 * tree of three NOPs (!). Which is harmless but annoying.
4972 * IOW: it is safe to do it unconditionally. */
4975 || ctx->ctx_res_w == RES_FI
4977 #if ENABLE_HUSH_LOOPS
4978 || ctx->ctx_res_w == RES_DONE
4979 || ctx->ctx_res_w == RES_FOR
4980 || ctx->ctx_res_w == RES_IN
4982 #if ENABLE_HUSH_CASE
4983 || ctx->ctx_res_w == RES_ESAC
4987 debug_printf_parse("done_pipe: adding new pipe: "
4988 "not_null:%d ctx->ctx_res_w:%d\n",
4989 not_null, ctx->ctx_res_w);
4991 ctx->pipe->next = new_p;
4993 /* RES_THEN, RES_DO etc are "sticky" -
4994 * they remain set for pipes inside if/while.
4995 * This is used to control execution.
4996 * RES_FOR and RES_IN are NOT sticky (needed to support
4997 * cases where variable or value happens to match a keyword):
4999 #if ENABLE_HUSH_LOOPS
5000 if (ctx->ctx_res_w == RES_FOR
5001 || ctx->ctx_res_w == RES_IN)
5002 ctx->ctx_res_w = RES_NONE;
5004 #if ENABLE_HUSH_CASE
5005 if (ctx->ctx_res_w == RES_MATCH)
5006 ctx->ctx_res_w = RES_CASE_BODY;
5007 if (ctx->ctx_res_w == RES_CASE)
5008 ctx->ctx_res_w = RES_CASE_IN;
5010 ctx->command = NULL; /* trick done_command below */
5011 /* Create the memory for command, roughly:
5012 * ctx->pipe->cmds = new struct command;
5013 * ctx->command = &ctx->pipe->cmds[0];
5016 //debug_print_tree(ctx->list_head, 10);
5018 debug_printf_parse("done_pipe return\n");
5021 static void initialize_context(struct parse_context *ctx)
5023 memset(ctx, 0, sizeof(*ctx));
5024 ctx->pipe = ctx->list_head = new_pipe();
5025 /* Create the memory for command, roughly:
5026 * ctx->pipe->cmds = new struct command;
5027 * ctx->command = &ctx->pipe->cmds[0];
5032 /* If a reserved word is found and processed, parse context is modified
5033 * and 1 is returned.
5036 struct reserved_combo {
5039 unsigned char assignment_flag;
5043 FLAG_END = (1 << RES_NONE ),
5045 FLAG_IF = (1 << RES_IF ),
5046 FLAG_THEN = (1 << RES_THEN ),
5047 FLAG_ELIF = (1 << RES_ELIF ),
5048 FLAG_ELSE = (1 << RES_ELSE ),
5049 FLAG_FI = (1 << RES_FI ),
5051 # if ENABLE_HUSH_LOOPS
5052 FLAG_FOR = (1 << RES_FOR ),
5053 FLAG_WHILE = (1 << RES_WHILE),
5054 FLAG_UNTIL = (1 << RES_UNTIL),
5055 FLAG_DO = (1 << RES_DO ),
5056 FLAG_DONE = (1 << RES_DONE ),
5057 FLAG_IN = (1 << RES_IN ),
5059 # if ENABLE_HUSH_CASE
5060 FLAG_MATCH = (1 << RES_MATCH),
5061 FLAG_ESAC = (1 << RES_ESAC ),
5063 FLAG_START = (1 << RES_XXXX ),
5066 static const struct reserved_combo* match_reserved_word(o_string *word)
5068 /* Mostly a list of accepted follow-up reserved words.
5069 * FLAG_END means we are done with the sequence, and are ready
5070 * to turn the compound list into a command.
5071 * FLAG_START means the word must start a new compound list.
5073 static const struct reserved_combo reserved_list[] = {
5075 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5076 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5077 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5078 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5079 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5080 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5082 # if ENABLE_HUSH_LOOPS
5083 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5084 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5085 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5086 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5087 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5088 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5090 # if ENABLE_HUSH_CASE
5091 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5092 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5095 const struct reserved_combo *r;
5097 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5098 if (strcmp(word->data, r->literal) == 0)
5103 /* Return 0: not a keyword, 1: keyword
5105 static int reserved_word(o_string *word, struct parse_context *ctx)
5107 # if ENABLE_HUSH_CASE
5108 static const struct reserved_combo reserved_match = {
5109 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5112 const struct reserved_combo *r;
5116 r = match_reserved_word(word);
5120 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5121 # if ENABLE_HUSH_CASE
5122 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5123 /* "case word IN ..." - IN part starts first MATCH part */
5124 r = &reserved_match;
5127 if (r->flag == 0) { /* '!' */
5128 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5129 syntax_error("! ! command");
5130 ctx->ctx_res_w = RES_SNTX;
5132 ctx->ctx_inverted = 1;
5135 if (r->flag & FLAG_START) {
5136 struct parse_context *old;
5138 old = xmalloc(sizeof(*old));
5139 debug_printf_parse("push stack %p\n", old);
5140 *old = *ctx; /* physical copy */
5141 initialize_context(ctx);
5143 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5144 syntax_error_at(word->data);
5145 ctx->ctx_res_w = RES_SNTX;
5148 /* "{...} fi" is ok. "{...} if" is not
5150 * if { echo foo; } then { echo bar; } fi */
5151 if (ctx->command->group)
5152 done_pipe(ctx, PIPE_SEQ);
5155 ctx->ctx_res_w = r->res;
5156 ctx->old_flag = r->flag;
5157 word->o_assignment = r->assignment_flag;
5159 if (ctx->old_flag & FLAG_END) {
5160 struct parse_context *old;
5162 done_pipe(ctx, PIPE_SEQ);
5163 debug_printf_parse("pop stack %p\n", ctx->stack);
5165 old->command->group = ctx->list_head;
5166 old->command->cmd_type = CMD_NORMAL;
5168 o_addstr(&old->as_string, ctx->as_string.data);
5169 o_free_unsafe(&ctx->as_string);
5170 old->command->group_as_string = xstrdup(old->as_string.data);
5171 debug_printf_parse("pop, remembering as:'%s'\n",
5172 old->command->group_as_string);
5174 *ctx = *old; /* physical copy */
5179 #endif /* HAS_KEYWORDS */
5181 /* Word is complete, look at it and update parsing context.
5182 * Normal return is 0. Syntax errors return 1.
5183 * Note: on return, word is reset, but not o_free'd!
5185 static int done_word(o_string *word, struct parse_context *ctx)
5187 struct command *command = ctx->command;
5189 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5190 if (word->length == 0 && word->o_quoted == 0) {
5191 debug_printf_parse("done_word return 0: true null, ignored\n");
5195 if (ctx->pending_redirect) {
5196 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5197 * only if run as "bash", not "sh" */
5198 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5200 * ...the word that follows the redirection operator
5201 * shall be subjected to tilde expansion, parameter expansion,
5202 * command substitution, arithmetic expansion, and quote
5203 * removal. Pathname expansion shall not be performed
5204 * on the word by a non-interactive shell; an interactive
5205 * shell may perform it, but shall do so only when
5206 * the expansion would result in one word."
5208 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5209 /* Cater for >\file case:
5210 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5211 * Same with heredocs:
5212 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5214 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5215 unbackslash(ctx->pending_redirect->rd_filename);
5216 /* Is it <<"HEREDOC"? */
5217 if (word->o_quoted) {
5218 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5221 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5222 ctx->pending_redirect = NULL;
5224 /* If this word wasn't an assignment, next ones definitely
5225 * can't be assignments. Even if they look like ones. */
5226 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5227 && word->o_assignment != WORD_IS_KEYWORD
5229 word->o_assignment = NOT_ASSIGNMENT;
5231 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5232 command->assignment_cnt++;
5233 word->o_assignment = MAYBE_ASSIGNMENT;
5237 # if ENABLE_HUSH_CASE
5238 if (ctx->ctx_dsemicolon
5239 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5241 /* already done when ctx_dsemicolon was set to 1: */
5242 /* ctx->ctx_res_w = RES_MATCH; */
5243 ctx->ctx_dsemicolon = 0;
5246 if (!command->argv /* if it's the first word... */
5247 # if ENABLE_HUSH_LOOPS
5248 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5249 && ctx->ctx_res_w != RES_IN
5251 # if ENABLE_HUSH_CASE
5252 && ctx->ctx_res_w != RES_CASE
5255 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5256 if (reserved_word(word, ctx)) {
5257 o_reset_to_empty_unquoted(word);
5258 debug_printf_parse("done_word return %d\n",
5259 (ctx->ctx_res_w == RES_SNTX));
5260 return (ctx->ctx_res_w == RES_SNTX);
5262 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5263 if (strcmp(word->data, "export") == 0
5264 # if ENABLE_HUSH_LOCAL
5265 || strcmp(word->data, "local") == 0
5268 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5271 # if ENABLE_HUSH_BASH_COMPAT
5272 if (strcmp(word->data, "[[") == 0) {
5273 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5279 if (command->group) {
5280 /* "{ echo foo; } echo bar" - bad */
5281 syntax_error_at(word->data);
5282 debug_printf_parse("done_word return 1: syntax error, "
5283 "groups and arglists don't mix\n");
5286 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5287 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5288 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5289 /* (otherwise it's known to be not empty and is already safe) */
5291 /* exclude "$@" - it can expand to no word despite "" */
5292 char *p = word->data;
5293 while (p[0] == SPECIAL_VAR_SYMBOL
5294 && (p[1] & 0x7f) == '@'
5295 && p[2] == SPECIAL_VAR_SYMBOL
5299 if (p == word->data || p[0] != '\0') {
5300 /* saw no "$@", or not only "$@" but some
5301 * real text is there too */
5302 /* insert "empty variable" reference, this makes
5303 * e.g. "", $empty"" etc to not disappear */
5304 o_addchr(word, SPECIAL_VAR_SYMBOL);
5305 o_addchr(word, SPECIAL_VAR_SYMBOL);
5308 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5309 debug_print_strings("word appended to argv", command->argv);
5312 #if ENABLE_HUSH_LOOPS
5313 if (ctx->ctx_res_w == RES_FOR) {
5315 || !is_well_formed_var_name(command->argv[0], '\0')
5317 /* bash says just "not a valid identifier" */
5318 syntax_error("not a valid identifier in for");
5321 /* Force FOR to have just one word (variable name) */
5322 /* NB: basically, this makes hush see "for v in ..."
5323 * syntax as if it is "for v; in ...". FOR and IN become
5324 * two pipe structs in parse tree. */
5325 done_pipe(ctx, PIPE_SEQ);
5328 #if ENABLE_HUSH_CASE
5329 /* Force CASE to have just one word */
5330 if (ctx->ctx_res_w == RES_CASE) {
5331 done_pipe(ctx, PIPE_SEQ);
5335 o_reset_to_empty_unquoted(word);
5337 debug_printf_parse("done_word return 0\n");
5342 /* Peek ahead in the input to find out if we have a "&n" construct,
5343 * as in "2>&1", that represents duplicating a file descriptor.
5345 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5346 * REDIRFD_SYNTAX_ERR if syntax error,
5347 * REDIRFD_TO_FILE if no & was seen,
5348 * or the number found.
5351 #define parse_redir_right_fd(as_string, input) \
5352 parse_redir_right_fd(input)
5354 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5360 return REDIRFD_TO_FILE;
5362 ch = i_getch(input); /* get the & */
5363 nommu_addchr(as_string, ch);
5366 ch = i_getch(input);
5367 nommu_addchr(as_string, ch);
5368 return REDIRFD_CLOSE;
5372 while (ch != EOF && isdigit(ch)) {
5373 d = d*10 + (ch-'0');
5375 ch = i_getch(input);
5376 nommu_addchr(as_string, ch);
5381 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5383 bb_error_msg("ambiguous redirect");
5384 return REDIRFD_SYNTAX_ERR;
5387 /* Return code is 0 normal, 1 if a syntax error is detected
5389 static int parse_redirect(struct parse_context *ctx,
5392 struct in_str *input)
5394 struct command *command = ctx->command;
5395 struct redir_struct *redir;
5396 struct redir_struct **redirp;
5399 dup_num = REDIRFD_TO_FILE;
5400 if (style != REDIRECT_HEREDOC) {
5401 /* Check for a '>&1' type redirect */
5402 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5403 if (dup_num == REDIRFD_SYNTAX_ERR)
5406 int ch = i_peek(input);
5407 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5408 if (dup_num) { /* <<-... */
5409 ch = i_getch(input);
5410 nommu_addchr(&ctx->as_string, ch);
5415 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5416 int ch = i_peek(input);
5418 /* >|FILE redirect ("clobbering" >).
5419 * Since we do not support "set -o noclobber" yet,
5420 * >| and > are the same for now. Just eat |.
5422 ch = i_getch(input);
5423 nommu_addchr(&ctx->as_string, ch);
5427 /* Create a new redir_struct and append it to the linked list */
5428 redirp = &command->redirects;
5429 while ((redir = *redirp) != NULL) {
5430 redirp = &(redir->next);
5432 *redirp = redir = xzalloc(sizeof(*redir));
5433 /* redir->next = NULL; */
5434 /* redir->rd_filename = NULL; */
5435 redir->rd_type = style;
5436 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5438 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5439 redir_table[style].descrip);
5441 redir->rd_dup = dup_num;
5442 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5443 /* Erik had a check here that the file descriptor in question
5444 * is legit; I postpone that to "run time"
5445 * A "-" representation of "close me" shows up as a -3 here */
5446 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5447 redir->rd_fd, redir->rd_dup);
5449 /* Set ctx->pending_redirect, so we know what to do at the
5450 * end of the next parsed word. */
5451 ctx->pending_redirect = redir;
5456 /* If a redirect is immediately preceded by a number, that number is
5457 * supposed to tell which file descriptor to redirect. This routine
5458 * looks for such preceding numbers. In an ideal world this routine
5459 * needs to handle all the following classes of redirects...
5460 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5461 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5462 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5463 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5465 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5467 * ... If n is quoted, the number shall not be recognized as part of
5468 * the redirection expression. For example:
5470 * writes the character 2 into file a"
5471 * We are getting it right by setting ->o_quoted on any \<char>
5473 * A -1 return means no valid number was found,
5474 * the caller should use the appropriate default for this redirection.
5476 static int redirect_opt_num(o_string *o)
5480 if (o->data == NULL)
5482 num = bb_strtou(o->data, NULL, 10);
5483 if (errno || num < 0)
5485 o_reset_to_empty_unquoted(o);
5490 #define fetch_till_str(as_string, input, word, skip_tabs) \
5491 fetch_till_str(input, word, skip_tabs)
5493 static char *fetch_till_str(o_string *as_string,
5494 struct in_str *input,
5498 o_string heredoc = NULL_O_STRING;
5504 ch = i_getch(input);
5505 nommu_addchr(as_string, ch);
5507 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5508 heredoc.data[past_EOL] = '\0';
5509 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5510 return heredoc.data;
5513 o_addchr(&heredoc, ch);
5514 past_EOL = heredoc.length;
5517 ch = i_getch(input);
5518 nommu_addchr(as_string, ch);
5519 } while (skip_tabs && ch == '\t');
5520 } while (ch == '\n');
5523 o_free_unsafe(&heredoc);
5526 o_addchr(&heredoc, ch);
5527 nommu_addchr(as_string, ch);
5531 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5532 * and load them all. There should be exactly heredoc_cnt of them.
5534 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5536 struct pipe *pi = ctx->list_head;
5538 while (pi && heredoc_cnt) {
5540 struct command *cmd = pi->cmds;
5542 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5544 cmd->argv ? cmd->argv[0] : "NONE");
5545 for (i = 0; i < pi->num_cmds; i++) {
5546 struct redir_struct *redir = cmd->redirects;
5548 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5549 i, cmd->argv ? cmd->argv[0] : "NONE");
5551 if (redir->rd_type == REDIRECT_HEREDOC) {
5554 redir->rd_type = REDIRECT_HEREDOC2;
5555 /* redir->rd_dup is (ab)used to indicate <<- */
5556 p = fetch_till_str(&ctx->as_string, input,
5557 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5559 syntax_error("unexpected EOF in here document");
5562 free(redir->rd_filename);
5563 redir->rd_filename = p;
5566 redir = redir->next;
5573 /* Should be 0. If it isn't, it's a parse error */
5575 bb_error_msg_and_die("heredoc BUG 2");
5581 #if ENABLE_HUSH_TICK
5582 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5587 char **to_free = NULL;
5591 pid = BB_MMU ? fork() : vfork();
5593 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5595 if (pid == 0) { /* child */
5596 disable_restore_tty_pgrp_on_exit();
5597 /* Process substitution is not considered to be usual
5598 * 'command execution'.
5599 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5606 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5607 close(channel[0]); /* NB: close _first_, then move fd! */
5608 xmove_fd(channel[1], 1);
5609 /* Prevent it from trying to handle ctrl-z etc */
5610 IF_HUSH_JOB(G.run_list_level = 1;)
5611 /* Awful hack for `trap` or $(trap).
5613 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5614 * contains an example where "trap" is executed in a subshell:
5616 * save_traps=$(trap)
5618 * eval "$save_traps"
5620 * Standard does not say that "trap" in subshell shall print
5621 * parent shell's traps. It only says that its output
5622 * must have suitable form, but then, in the above example
5623 * (which is not supposed to be normative), it implies that.
5625 * bash (and probably other shell) does implement it
5626 * (traps are reset to defaults, but "trap" still shows them),
5627 * but as a result, "trap" logic is hopelessly messed up:
5630 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5631 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5632 * # true | trap <--- trap is in subshell - no output (ditto)
5633 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5634 * trap -- 'echo Ho' SIGWINCH
5635 * # echo `(trap)` <--- in subshell in subshell - output
5636 * trap -- 'echo Ho' SIGWINCH
5637 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5638 * trap -- 'echo Ho' SIGWINCH
5640 * The rules when to forget and when to not forget traps
5641 * get really complex and nonsensical.
5643 * Our solution: ONLY bare $(trap) or `trap` is special.
5645 s = skip_whitespace(s);
5646 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5648 static const char *const argv[] = { NULL, NULL };
5649 builtin_trap((char**)argv);
5650 exit(0); /* not _exit() - we need to fflush */
5653 reset_traps_to_defaults();
5654 parse_and_run_string(s);
5655 _exit(G.last_exitcode);
5657 /* We re-execute after vfork on NOMMU. This makes this script safe:
5658 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5659 * huge=`cat BIG` # was blocking here forever
5662 re_execute_shell(&to_free,
5672 # if ENABLE_HUSH_FAST
5674 //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);
5676 enable_restore_tty_pgrp_on_exit();
5681 close_on_exec_on(channel[0]);
5682 return xfdopen_for_read(channel[0]);
5685 /* Return code is exit status of the process that is run. */
5686 static int process_command_subs(o_string *dest, const char *s)
5689 struct in_str pipe_str;
5691 int status, ch, eol_cnt;
5693 fp = generate_stream_from_string(s, &pid);
5695 /* Now send results of command back into original context */
5696 setup_file_in_str(&pipe_str, fp);
5698 while ((ch = i_getch(&pipe_str)) != EOF) {
5704 o_addchr(dest, '\n');
5707 o_addQchr(dest, ch);
5710 debug_printf("done reading from `cmd` pipe, closing it\n");
5712 /* We need to extract exitcode. Test case
5713 * "true; echo `sleep 1; false` $?"
5715 safe_waitpid(pid, &status, 0);
5716 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5717 return WEXITSTATUS(status);
5719 #endif /* ENABLE_HUSH_TICK */
5721 #if !ENABLE_HUSH_FUNCTIONS
5722 #define parse_group(dest, ctx, input, ch) \
5723 parse_group(ctx, input, ch)
5725 static int parse_group(o_string *dest, struct parse_context *ctx,
5726 struct in_str *input, int ch)
5728 /* dest contains characters seen prior to ( or {.
5729 * Typically it's empty, but for function defs,
5730 * it contains function name (without '()'). */
5731 struct pipe *pipe_list;
5733 struct command *command = ctx->command;
5735 debug_printf_parse("parse_group entered\n");
5736 #if ENABLE_HUSH_FUNCTIONS
5737 if (ch == '(' && !dest->o_quoted) {
5739 if (done_word(dest, ctx))
5742 goto skip; /* (... */
5743 if (command->argv[1]) { /* word word ... (... */
5744 syntax_error_unexpected_ch('(');
5747 /* it is "word(..." or "word (..." */
5749 ch = i_getch(input);
5750 while (ch == ' ' || ch == '\t');
5752 syntax_error_unexpected_ch(ch);
5755 nommu_addchr(&ctx->as_string, ch);
5757 ch = i_getch(input);
5758 while (ch == ' ' || ch == '\t' || ch == '\n');
5760 syntax_error_unexpected_ch(ch);
5763 nommu_addchr(&ctx->as_string, ch);
5764 command->cmd_type = CMD_FUNCDEF;
5769 #if 0 /* Prevented by caller */
5770 if (command->argv /* word [word]{... */
5771 || dest->length /* word{... */
5772 || dest->o_quoted /* ""{... */
5775 debug_printf_parse("parse_group return 1: "
5776 "syntax error, groups and arglists don't mix\n");
5781 #if ENABLE_HUSH_FUNCTIONS
5787 command->cmd_type = CMD_SUBSHELL;
5789 /* bash does not allow "{echo...", requires whitespace */
5790 ch = i_getch(input);
5791 if (ch != ' ' && ch != '\t' && ch != '\n') {
5792 syntax_error_unexpected_ch(ch);
5795 nommu_addchr(&ctx->as_string, ch);
5800 # define as_string NULL
5802 char *as_string = NULL;
5804 pipe_list = parse_stream(&as_string, input, endch);
5807 o_addstr(&ctx->as_string, as_string);
5809 /* empty ()/{} or parse error? */
5810 if (!pipe_list || pipe_list == ERR_PTR) {
5811 /* parse_stream already emitted error msg */
5814 debug_printf_parse("parse_group return 1: "
5815 "parse_stream returned %p\n", pipe_list);
5818 command->group = pipe_list;
5820 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5821 command->group_as_string = as_string;
5822 debug_printf_parse("end of group, remembering as:'%s'\n",
5823 command->group_as_string);
5827 debug_printf_parse("parse_group return 0\n");
5829 /* command remains "open", available for possible redirects */
5832 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5833 /* Subroutines for copying $(...) and `...` things */
5834 static void add_till_backquote(o_string *dest, struct in_str *input);
5836 static void add_till_single_quote(o_string *dest, struct in_str *input)
5839 int ch = i_getch(input);
5841 syntax_error_unterm_ch('\'');
5842 /*xfunc_die(); - redundant */
5849 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5850 static void add_till_double_quote(o_string *dest, struct in_str *input)
5853 int ch = i_getch(input);
5855 syntax_error_unterm_ch('"');
5856 /*xfunc_die(); - redundant */
5860 if (ch == '\\') { /* \x. Copy both chars. */
5862 ch = i_getch(input);
5866 add_till_backquote(dest, input);
5870 //if (ch == '$') ...
5873 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5875 * "Within the backquoted style of command substitution, backslash
5876 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5877 * The search for the matching backquote shall be satisfied by the first
5878 * backquote found without a preceding backslash; during this search,
5879 * if a non-escaped backquote is encountered within a shell comment,
5880 * a here-document, an embedded command substitution of the $(command)
5881 * form, or a quoted string, undefined results occur. A single-quoted
5882 * or double-quoted string that begins, but does not end, within the
5883 * "`...`" sequence produces undefined results."
5885 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5887 static void add_till_backquote(o_string *dest, struct in_str *input)
5890 int ch = i_getch(input);
5892 syntax_error_unterm_ch('`');
5893 /*xfunc_die(); - redundant */
5898 /* \x. Copy both chars unless it is \` */
5899 int ch2 = i_getch(input);
5901 syntax_error_unterm_ch('`');
5902 /*xfunc_die(); - redundant */
5904 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5911 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5912 * quoting and nested ()s.
5913 * "With the $(command) style of command substitution, all characters
5914 * following the open parenthesis to the matching closing parenthesis
5915 * constitute the command. Any valid shell script can be used for command,
5916 * except a script consisting solely of redirections which produces
5917 * unspecified results."
5919 * echo $(echo '(TEST)' BEST) (TEST) BEST
5920 * echo $(echo 'TEST)' BEST) TEST) BEST
5921 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5923 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
5924 * can contain arbitrary constructs, just like $(cmd).
5925 * In bash compat mode, it needs to also be able to stop on '}' or ':'
5926 * for ${var:N[:M]} parsing.
5928 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
5929 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
5932 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
5933 #if ENABLE_HUSH_BASH_COMPAT
5934 char end_char2 = end_ch >> 8;
5936 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
5939 ch = i_getch(input);
5941 syntax_error_unterm_ch(end_ch);
5942 /*xfunc_die(); - redundant */
5944 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
5947 /* we look for closing )) of $((EXPR)) */
5948 if (i_peek(input) == end_ch) {
5949 i_getch(input); /* eat second ')' */
5954 if (ch == '(' || ch == '{') {
5955 ch = (ch == '(' ? ')' : '}');
5956 add_till_closing_bracket(dest, input, ch);
5961 add_till_single_quote(dest, input);
5966 add_till_double_quote(dest, input);
5971 add_till_backquote(dest, input);
5976 /* \x. Copy verbatim. Important for \(, \) */
5977 ch = i_getch(input);
5979 syntax_error_unterm_ch(')');
5980 /*xfunc_die(); - redundant */
5988 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5990 /* Return code: 0 for OK, 1 for syntax error */
5992 #define parse_dollar(as_string, dest, input) \
5993 parse_dollar(dest, input)
5994 #define as_string NULL
5996 static int parse_dollar(o_string *as_string,
5998 struct in_str *input)
6000 int ch = i_peek(input); /* first character after the $ */
6001 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
6003 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
6005 ch = i_getch(input);
6006 nommu_addchr(as_string, ch);
6008 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6010 debug_printf_parse(": '%c'\n", ch);
6011 o_addchr(dest, ch | quote_mask);
6014 if (!isalnum(ch) && ch != '_')
6016 ch = i_getch(input);
6017 nommu_addchr(as_string, ch);
6019 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6020 } else if (isdigit(ch)) {
6022 ch = i_getch(input);
6023 nommu_addchr(as_string, ch);
6024 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6025 debug_printf_parse(": '%c'\n", ch);
6026 o_addchr(dest, ch | quote_mask);
6027 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6028 } else switch (ch) {
6030 case '!': /* last bg pid */
6031 case '?': /* last exit code */
6032 case '#': /* number of args */
6033 case '*': /* args */
6034 case '@': /* args */
6035 goto make_one_char_var;
6037 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6039 ch = i_getch(input); /* eat '{' */
6040 nommu_addchr(as_string, ch);
6042 ch = i_getch(input); /* first char after '{' */
6043 nommu_addchr(as_string, ch);
6044 /* It should be ${?}, or ${#var},
6045 * or even ${?+subst} - operator acting on a special variable,
6046 * or the beginning of variable name.
6048 if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
6050 syntax_error_unterm_str("${name}");
6051 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
6056 /* It's possible to just call add_till_closing_bracket() at this point.
6057 * However, this regresses some of our testsuite cases
6058 * which check invalid constructs like ${%}.
6059 * Oh well... let's check that the var name part is fine... */
6065 debug_printf_parse(": '%c'\n", ch);
6067 ch = i_getch(input);
6068 nommu_addchr(as_string, ch);
6072 if (!isalnum(ch) && ch != '_') {
6074 unsigned char last_ch;
6075 /* handle parameter expansions
6076 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6078 if (!strchr("%#:-=+?", ch)) /* ${var<bad_char>... */
6079 goto bad_dollar_syntax;
6082 /* Eat everything until closing '}' (or ':') */
6084 if (ENABLE_HUSH_BASH_COMPAT
6086 && !strchr("%#:-=+?"+3, i_peek(input))
6088 /* It's ${var:N[:M]} thing */
6089 end_ch = '}' * 0x100 + ':';
6094 last_ch = add_till_closing_bracket(dest, input, end_ch);
6096 o_addstr(as_string, dest->data + pos);
6097 o_addchr(as_string, last_ch);
6100 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
6101 /* close the first block: */
6102 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6103 /* while parsing N from ${var:N[:M]}... */
6104 if ((end_ch & 0xff) == last_ch) {
6105 /* ...got ':' - parse the rest */
6109 /* ...got '}', not ':' - it's ${var:N}! emulate :999999999 */
6110 o_addstr(dest, "999999999");
6115 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6118 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6122 ch = i_getch(input);
6123 nommu_addchr(as_string, ch);
6124 # if ENABLE_SH_MATH_SUPPORT
6125 if (i_peek(input) == '(') {
6126 ch = i_getch(input);
6127 nommu_addchr(as_string, ch);
6128 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6129 o_addchr(dest, /*quote_mask |*/ '+');
6132 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
6134 o_addstr(as_string, dest->data + pos);
6135 o_addchr(as_string, ')');
6136 o_addchr(as_string, ')');
6138 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6142 # if ENABLE_HUSH_TICK
6143 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6144 o_addchr(dest, quote_mask | '`');
6147 add_till_closing_bracket(dest, input, ')');
6149 o_addstr(as_string, dest->data + pos);
6150 o_addchr(as_string, ')');
6152 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6158 ch = i_getch(input);
6159 nommu_addchr(as_string, ch);
6161 if (isalnum(ch)) { /* it's $_name or $_123 */
6166 /* TODO: $_ and $-: */
6167 /* $_ Shell or shell script name; or last argument of last command
6168 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6169 * but in command's env, set to full pathname used to invoke it */
6170 /* $- Option flags set by set builtin or shell options (-i etc) */
6172 o_addQchr(dest, '$');
6174 debug_printf_parse("parse_dollar return 0\n");
6180 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6181 parse_stream_dquoted(dest, input, dquote_end)
6182 #define as_string NULL
6184 static int parse_stream_dquoted(o_string *as_string,
6186 struct in_str *input,
6193 ch = i_getch(input);
6195 nommu_addchr(as_string, ch);
6196 if (ch == dquote_end) { /* may be only '"' or EOF */
6197 if (dest->o_assignment == NOT_ASSIGNMENT)
6198 dest->o_escape ^= 1;
6199 debug_printf_parse("parse_stream_dquoted return 0\n");
6202 /* note: can't move it above ch == dquote_end check! */
6204 syntax_error_unterm_ch('"');
6205 /*xfunc_die(); - redundant */
6209 next = i_peek(input);
6211 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6212 ch, ch, dest->o_escape);
6215 syntax_error("\\<eof>");
6219 * "The backslash retains its special meaning [in "..."]
6220 * only when followed by one of the following characters:
6221 * $, `, ", \, or <newline>. A double quote may be quoted
6222 * within double quotes by preceding it with a backslash."
6224 if (strchr("$`\"\\\n", next) != NULL) {
6225 ch = i_getch(input);
6227 o_addqchr(dest, ch);
6228 nommu_addchr(as_string, ch);
6231 o_addqchr(dest, '\\');
6232 nommu_addchr(as_string, '\\');
6237 if (parse_dollar(as_string, dest, input) != 0) {
6238 debug_printf_parse("parse_stream_dquoted return 1: "
6239 "parse_dollar returned non-0\n");
6244 #if ENABLE_HUSH_TICK
6246 //unsigned pos = dest->length;
6247 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6248 o_addchr(dest, 0x80 | '`');
6249 add_till_backquote(dest, input);
6250 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6251 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6255 o_addQchr(dest, ch);
6257 && (dest->o_assignment == MAYBE_ASSIGNMENT
6258 || dest->o_assignment == WORD_IS_KEYWORD)
6259 && is_well_formed_var_name(dest->data, '=')
6261 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6268 * Scan input until EOF or end_trigger char.
6269 * Return a list of pipes to execute, or NULL on EOF
6270 * or if end_trigger character is met.
6271 * On syntax error, exit is shell is not interactive,
6272 * reset parsing machinery and start parsing anew,
6273 * or return ERR_PTR.
6275 static struct pipe *parse_stream(char **pstring,
6276 struct in_str *input,
6279 struct parse_context ctx;
6280 o_string dest = NULL_O_STRING;
6284 /* Double-quote state is handled in the state variable is_in_dquote.
6285 * A single-quote triggers a bypass of the main loop until its mate is
6286 * found. When recursing, quote state is passed in via dest->o_escape.
6288 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6289 end_trigger ? end_trigger : 'X');
6292 /* If very first arg is "" or '', dest.data may end up NULL.
6293 * Preventing this: */
6294 o_addchr(&dest, '\0');
6297 G.ifs = get_local_var_value("IFS");
6302 #if ENABLE_HUSH_INTERACTIVE
6303 input->promptmode = 0; /* PS1 */
6305 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6306 initialize_context(&ctx);
6311 const char *is_special;
6315 redir_type redir_style;
6318 /* dest.o_quoted = 1; - already is (see below) */
6319 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6322 /* We reached closing '"' */
6325 ch = i_getch(input);
6326 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6327 ch, ch, dest.o_escape);
6332 syntax_error_unterm_str("here document");
6335 /* end_trigger == '}' case errors out earlier,
6336 * checking only ')' */
6337 if (end_trigger == ')') {
6338 syntax_error_unterm_ch('('); /* exits */
6339 /* goto parse_error; */
6342 if (done_word(&dest, &ctx)) {
6346 done_pipe(&ctx, PIPE_SEQ);
6348 /* If we got nothing... */
6349 /* (this makes bare "&" cmd a no-op.
6350 * bash says: "syntax error near unexpected token '&'") */
6351 if (pi->num_cmds == 0
6352 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6358 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6360 *pstring = ctx.as_string.data;
6362 o_free_unsafe(&ctx.as_string);
6365 debug_printf_parse("parse_stream return %p\n", pi);
6368 nommu_addchr(&ctx.as_string, ch);
6372 next = i_peek(input);
6374 is_special = "{}<>;&|()#'" /* special outside of "str" */
6375 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6376 /* Are { and } special here? */
6377 if (ctx.command->argv /* word [word]{... - non-special */
6378 || dest.length /* word{... - non-special */
6379 || dest.o_quoted /* ""{... - non-special */
6380 || (next != ';' /* }; - special */
6381 && next != ')' /* }) - special */
6382 && next != '&' /* }& and }&& ... - special */
6383 && next != '|' /* }|| ... - special */
6384 && !strchr(G.ifs, next) /* {word - non-special */
6387 /* They are not special, skip "{}" */
6390 is_special = strchr(is_special, ch);
6391 is_ifs = strchr(G.ifs, ch);
6393 if (!is_special && !is_ifs) { /* ordinary char */
6395 o_addQchr(&dest, ch);
6396 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6397 || dest.o_assignment == WORD_IS_KEYWORD)
6399 && is_well_formed_var_name(dest.data, '=')
6401 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6407 if (done_word(&dest, &ctx)) {
6411 #if ENABLE_HUSH_CASE
6412 /* "case ... in <newline> word) ..." -
6413 * newlines are ignored (but ';' wouldn't be) */
6414 if (ctx.command->argv == NULL
6415 && ctx.ctx_res_w == RES_MATCH
6420 /* Treat newline as a command separator. */
6421 done_pipe(&ctx, PIPE_SEQ);
6422 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6424 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6429 dest.o_assignment = MAYBE_ASSIGNMENT;
6431 /* note: if (is_ifs) continue;
6432 * will still trigger for us */
6436 /* "cmd}" or "cmd }..." without semicolon or &:
6437 * } is an ordinary char in this case, even inside { cmd; }
6438 * Pathological example: { ""}; } should exec "}" cmd
6441 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6442 || dest.length != 0 /* word} */
6443 || dest.o_quoted /* ""} */
6447 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6448 goto skip_end_trigger;
6449 /* else: } does terminate a group */
6452 if (end_trigger && end_trigger == ch
6453 && (ch != ';' || heredoc_cnt == 0)
6454 #if ENABLE_HUSH_CASE
6456 || ctx.ctx_res_w != RES_MATCH
6457 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6462 /* This is technically valid:
6463 * { cat <<HERE; }; echo Ok
6467 * but we don't support this.
6468 * We require heredoc to be in enclosing {}/(),
6471 syntax_error_unterm_str("here document");
6474 if (done_word(&dest, &ctx)) {
6477 done_pipe(&ctx, PIPE_SEQ);
6478 dest.o_assignment = MAYBE_ASSIGNMENT;
6479 /* Do we sit outside of any if's, loops or case's? */
6481 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6485 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6487 *pstring = ctx.as_string.data;
6489 o_free_unsafe(&ctx.as_string);
6492 debug_printf_parse("parse_stream return %p: "
6493 "end_trigger char found\n",
6495 return ctx.list_head;
6502 /* Catch <, > before deciding whether this word is
6503 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6506 redir_fd = redirect_opt_num(&dest);
6507 if (done_word(&dest, &ctx)) {
6510 redir_style = REDIRECT_OVERWRITE;
6512 redir_style = REDIRECT_APPEND;
6513 ch = i_getch(input);
6514 nommu_addchr(&ctx.as_string, ch);
6517 else if (next == '(') {
6518 syntax_error(">(process) not supported");
6522 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6524 continue; /* back to top of while (1) */
6526 redir_fd = redirect_opt_num(&dest);
6527 if (done_word(&dest, &ctx)) {
6530 redir_style = REDIRECT_INPUT;
6532 redir_style = REDIRECT_HEREDOC;
6534 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6535 ch = i_getch(input);
6536 nommu_addchr(&ctx.as_string, ch);
6537 } else if (next == '>') {
6538 redir_style = REDIRECT_IO;
6539 ch = i_getch(input);
6540 nommu_addchr(&ctx.as_string, ch);
6543 else if (next == '(') {
6544 syntax_error("<(process) not supported");
6548 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6550 continue; /* back to top of while (1) */
6553 if (dest.o_assignment == MAYBE_ASSIGNMENT
6554 /* check that we are not in word in "a=1 2>word b=1": */
6555 && !ctx.pending_redirect
6557 /* ch is a special char and thus this word
6558 * cannot be an assignment */
6559 dest.o_assignment = NOT_ASSIGNMENT;
6562 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6566 if (dest.length == 0) {
6569 if (ch == EOF || ch == '\n')
6572 /* note: we do not add it to &ctx.as_string */
6574 nommu_addchr(&ctx.as_string, '\n');
6576 o_addQchr(&dest, ch);
6581 syntax_error("\\<eof>");
6584 ch = i_getch(input);
6586 o_addchr(&dest, '\\');
6587 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6588 o_addchr(&dest, ch);
6589 nommu_addchr(&ctx.as_string, ch);
6590 /* Example: echo Hello \2>file
6591 * we need to know that word 2 is quoted */
6596 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6597 ctx.as_string.data[--ctx.as_string.length] = '\0';
6602 if (parse_dollar(&ctx.as_string, &dest, input) != 0) {
6603 debug_printf_parse("parse_stream parse error: "
6604 "parse_dollar returned non-0\n");
6611 ch = i_getch(input);
6613 syntax_error_unterm_ch('\'');
6614 /*xfunc_die(); - redundant */
6616 nommu_addchr(&ctx.as_string, ch);
6619 o_addqchr(&dest, ch);
6624 is_in_dquote ^= 1; /* invert */
6625 if (dest.o_assignment == NOT_ASSIGNMENT)
6628 #if ENABLE_HUSH_TICK
6632 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6633 o_addchr(&dest, '`');
6635 add_till_backquote(&dest, input);
6637 o_addstr(&ctx.as_string, dest.data + pos);
6638 o_addchr(&ctx.as_string, '`');
6640 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6641 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6646 #if ENABLE_HUSH_CASE
6649 if (done_word(&dest, &ctx)) {
6652 done_pipe(&ctx, PIPE_SEQ);
6653 #if ENABLE_HUSH_CASE
6654 /* Eat multiple semicolons, detect
6655 * whether it means something special */
6660 ch = i_getch(input);
6661 nommu_addchr(&ctx.as_string, ch);
6662 if (ctx.ctx_res_w == RES_CASE_BODY) {
6663 ctx.ctx_dsemicolon = 1;
6664 ctx.ctx_res_w = RES_MATCH;
6670 /* We just finished a cmd. New one may start
6671 * with an assignment */
6672 dest.o_assignment = MAYBE_ASSIGNMENT;
6675 if (done_word(&dest, &ctx)) {
6679 ch = i_getch(input);
6680 nommu_addchr(&ctx.as_string, ch);
6681 done_pipe(&ctx, PIPE_AND);
6683 done_pipe(&ctx, PIPE_BG);
6687 if (done_word(&dest, &ctx)) {
6690 #if ENABLE_HUSH_CASE
6691 if (ctx.ctx_res_w == RES_MATCH)
6692 break; /* we are in case's "word | word)" */
6694 if (next == '|') { /* || */
6695 ch = i_getch(input);
6696 nommu_addchr(&ctx.as_string, ch);
6697 done_pipe(&ctx, PIPE_OR);
6699 /* we could pick up a file descriptor choice here
6700 * with redirect_opt_num(), but bash doesn't do it.
6701 * "echo foo 2| cat" yields "foo 2". */
6704 o_reset_to_empty_unquoted(&ctx.as_string);
6709 #if ENABLE_HUSH_CASE
6710 /* "case... in [(]word)..." - skip '(' */
6711 if (ctx.ctx_res_w == RES_MATCH
6712 && ctx.command->argv == NULL /* not (word|(... */
6713 && dest.length == 0 /* not word(... */
6714 && dest.o_quoted == 0 /* not ""(... */
6720 if (parse_group(&dest, &ctx, input, ch) != 0) {
6725 #if ENABLE_HUSH_CASE
6726 if (ctx.ctx_res_w == RES_MATCH)
6730 /* proper use of this character is caught by end_trigger:
6731 * if we see {, we call parse_group(..., end_trigger='}')
6732 * and it will match } earlier (not here). */
6733 syntax_error_unexpected_ch(ch);
6737 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6743 struct parse_context *pctx;
6744 IF_HAS_KEYWORDS(struct parse_context *p2;)
6746 /* Clean up allocated tree.
6747 * Sample for finding leaks on syntax error recovery path.
6748 * Run it from interactive shell, watch pmap `pidof hush`.
6749 * while if false; then false; fi; do break; fi
6750 * Samples to catch leaks at execution:
6751 * while if (true | {true;}); then echo ok; fi; do break; done
6752 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6756 /* Update pipe/command counts,
6757 * otherwise freeing may miss some */
6758 done_pipe(pctx, PIPE_SEQ);
6759 debug_printf_clean("freeing list %p from ctx %p\n",
6760 pctx->list_head, pctx);
6761 debug_print_tree(pctx->list_head, 0);
6762 free_pipe_list(pctx->list_head);
6763 debug_printf_clean("freed list %p\n", pctx->list_head);
6765 o_free_unsafe(&pctx->as_string);
6767 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6771 IF_HAS_KEYWORDS(pctx = p2;)
6772 } while (HAS_KEYWORDS && pctx);
6773 /* Free text, clear all dest fields */
6775 /* If we are not in top-level parse, we return,
6776 * our caller will propagate error.
6778 if (end_trigger != ';') {
6786 /* Discard cached input, force prompt */
6788 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6793 /* Executing from string: eval, sh -c '...'
6794 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6795 * end_trigger controls how often we stop parsing
6796 * NUL: parse all, execute, return
6797 * ';': parse till ';' or newline, execute, repeat till EOF
6799 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6801 /* Why we need empty flag?
6802 * An obscure corner case "false; ``; echo $?":
6803 * empty command in `` should still set $? to 0.
6804 * But we can't just set $? to 0 at the start,
6805 * this breaks "false; echo `echo $?`" case.
6809 struct pipe *pipe_list;
6811 pipe_list = parse_stream(NULL, inp, end_trigger);
6812 if (!pipe_list) { /* EOF */
6814 G.last_exitcode = 0;
6817 debug_print_tree(pipe_list, 0);
6818 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6819 run_and_free_list(pipe_list);
6824 static void parse_and_run_string(const char *s)
6826 struct in_str input;
6827 setup_string_in_str(&input, s);
6828 parse_and_run_stream(&input, '\0');
6831 static void parse_and_run_file(FILE *f)
6833 struct in_str input;
6834 setup_file_in_str(&input, f);
6835 parse_and_run_stream(&input, ';');
6838 /* Called a few times only (or even once if "sh -c") */
6839 static void init_sigmasks(void)
6843 sigset_t old_blocked_set;
6845 if (!G.inherited_set_is_saved) {
6846 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6847 G.inherited_set = G.blocked_set;
6849 old_blocked_set = G.blocked_set;
6851 mask = (1 << SIGQUIT);
6852 if (G_interactive_fd) {
6853 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6854 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6855 mask |= SPECIAL_JOB_SIGS;
6857 G.non_DFL_mask = mask;
6862 sigaddset(&G.blocked_set, sig);
6866 sigdelset(&G.blocked_set, SIGCHLD);
6868 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6869 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6871 /* POSIX allows shell to re-enable SIGCHLD
6872 * even if it was SIG_IGN on entry */
6873 #if ENABLE_HUSH_FAST
6874 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6875 if (!G.inherited_set_is_saved)
6876 signal(SIGCHLD, SIGCHLD_handler);
6878 if (!G.inherited_set_is_saved)
6879 signal(SIGCHLD, SIG_DFL);
6882 G.inherited_set_is_saved = 1;
6887 static void maybe_set_to_sigexit(int sig)
6889 void (*handler)(int);
6890 /* non_DFL_mask'ed signals are, well, masked,
6891 * no need to set handler for them.
6893 if (!((G.non_DFL_mask >> sig) & 1)) {
6894 handler = signal(sig, sigexit);
6895 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6896 signal(sig, handler);
6899 /* Set handlers to restore tty pgrp and exit */
6900 static void set_fatal_handlers(void)
6902 /* We _must_ restore tty pgrp on fatal signals */
6904 maybe_set_to_sigexit(SIGILL );
6905 maybe_set_to_sigexit(SIGFPE );
6906 maybe_set_to_sigexit(SIGBUS );
6907 maybe_set_to_sigexit(SIGSEGV);
6908 maybe_set_to_sigexit(SIGTRAP);
6909 } /* else: hush is perfect. what SEGV? */
6910 maybe_set_to_sigexit(SIGABRT);
6911 /* bash 3.2 seems to handle these just like 'fatal' ones */
6912 maybe_set_to_sigexit(SIGPIPE);
6913 maybe_set_to_sigexit(SIGALRM);
6914 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6915 * if we aren't interactive... but in this case
6916 * we never want to restore pgrp on exit, and this fn is not called */
6917 /*maybe_set_to_sigexit(SIGHUP );*/
6918 /*maybe_set_to_sigexit(SIGTERM);*/
6919 /*maybe_set_to_sigexit(SIGINT );*/
6923 static int set_mode(const char cstate, const char mode)
6925 int state = (cstate == '-' ? 1 : 0);
6927 case 'n': G.fake_mode = state; break;
6928 case 'x': /*G.debug_mode = state;*/ break;
6929 default: return EXIT_FAILURE;
6931 return EXIT_SUCCESS;
6934 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6935 int hush_main(int argc, char **argv)
6937 static const struct variable const_shell_ver = {
6939 .varstr = (char*)hush_version_str,
6940 .max_len = 1, /* 0 can provoke free(name) */
6945 unsigned builtin_argc;
6947 struct variable *cur_var;
6950 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6951 G.last_exitcode = EXIT_SUCCESS;
6953 G.argv0_for_re_execing = argv[0];
6955 /* Deal with HUSH_VERSION */
6956 G.shell_ver = const_shell_ver; /* copying struct here */
6957 G.top_var = &G.shell_ver;
6958 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6959 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6960 /* Initialize our shell local variables with the values
6961 * currently living in the environment */
6962 cur_var = G.top_var;
6965 char *value = strchr(*e, '=');
6966 if (value) { /* paranoia */
6967 cur_var->next = xzalloc(sizeof(*cur_var));
6968 cur_var = cur_var->next;
6969 cur_var->varstr = *e;
6970 cur_var->max_len = strlen(*e);
6971 cur_var->flg_export = 1;
6975 /* reinstate HUSH_VERSION */
6976 debug_printf_env("putenv '%s'\n", hush_version_str);
6977 putenv((char *)hush_version_str);
6980 set_pwd_var(/*exp:*/ 1);
6981 /* bash also exports SHLVL and _,
6982 * and sets (but doesn't export) the following variables:
6984 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6985 * BASH_VERSION='3.2.0(1)-release'
6987 * MACHTYPE=i386-pc-linux-gnu
6989 * HOSTNAME=<xxxxxxxxxx>
6990 * PPID=<NNNNN> - we also do it elsewhere
7001 * PIPESTATUS=([0]="0")
7002 * HISTFILE=/<xxx>/.bash_history
7006 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7008 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7018 #if ENABLE_FEATURE_EDITING
7019 G.line_input_state = new_line_input_t(FOR_SHELL);
7021 G.global_argc = argc;
7022 G.global_argv = argv;
7023 /* Initialize some more globals to non-zero values */
7024 cmdedit_update_prompt();
7026 if (setjmp(die_jmp)) {
7027 /* xfunc has failed! die die die */
7028 /* no EXIT traps, this is an escape hatch! */
7030 hush_exit(xfunc_error_retval);
7033 /* Shell is non-interactive at first. We need to call
7034 * init_sigmasks() if we are going to execute "sh <script>",
7035 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7036 * If we later decide that we are interactive, we run init_sigmasks()
7037 * in order to intercept (more) signals.
7041 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7044 opt = getopt(argc, argv, "+c:xins"
7047 # if ENABLE_HUSH_FUNCTIONS
7057 * sh ... -c 'script'
7058 * sh ... -c 'script' ARG0 [ARG1...]
7059 * On NOMMU, if builtin_argc != 0,
7060 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7061 * "" needs to be replaced with NULL
7062 * and BARGV vector fed to builtin function.
7063 * Note: the form without ARG0 never happens:
7064 * sh ... -c 'builtin' BARGV... ""
7067 G.root_pid = getpid();
7068 G.root_ppid = getppid();
7070 G.global_argv = argv + optind;
7071 G.global_argc = argc - optind;
7073 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7074 const struct built_in_command *x;
7077 x = find_builtin(optarg);
7078 if (x) { /* paranoia */
7079 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7080 G.global_argv += builtin_argc;
7081 G.global_argv[-1] = NULL; /* replace "" */
7082 G.last_exitcode = x->b_function(argv + optind - 1);
7086 if (!G.global_argv[0]) {
7087 /* -c 'script' (no params): prevent empty $0 */
7088 G.global_argv--; /* points to argv[i] of 'script' */
7089 G.global_argv[0] = argv[0];
7091 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7093 parse_and_run_string(optarg);
7096 /* Well, we cannot just declare interactiveness,
7097 * we have to have some stuff (ctty, etc) */
7098 /* G_interactive_fd++; */
7101 /* "-s" means "read from stdin", but this is how we always
7102 * operate, so simply do nothing here. */
7105 case '<': /* "big heredoc" support */
7106 full_write1_str(optarg);
7109 unsigned long long empty_trap_mask;
7111 G.root_pid = bb_strtou(optarg, &optarg, 16);
7113 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7115 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7117 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7119 builtin_argc = bb_strtou(optarg, &optarg, 16);
7121 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7122 if (empty_trap_mask != 0) {
7125 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7126 for (sig = 1; sig < NSIG; sig++) {
7127 if (empty_trap_mask & (1LL << sig)) {
7128 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7129 sigaddset(&G.blocked_set, sig);
7132 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7134 # if ENABLE_HUSH_LOOPS
7136 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7142 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7144 # if ENABLE_HUSH_FUNCTIONS
7146 struct function *funcp = new_function(optarg);
7147 /* funcp->name is already set to optarg */
7148 /* funcp->body is set to NULL. It's a special case. */
7149 funcp->body_as_string = argv[optind];
7157 if (!set_mode('-', opt))
7161 fprintf(stderr, "Usage: sh [FILE]...\n"
7162 " or: sh -c command [args]...\n\n");
7168 } /* option parsing loop */
7171 G.root_pid = getpid();
7172 G.root_ppid = getppid();
7175 /* If we are login shell... */
7176 if (argv[0] && argv[0][0] == '-') {
7178 debug_printf("sourcing /etc/profile\n");
7179 input = fopen_for_read("/etc/profile");
7180 if (input != NULL) {
7181 close_on_exec_on(fileno(input));
7183 parse_and_run_file(input);
7186 /* bash: after sourcing /etc/profile,
7187 * tries to source (in the given order):
7188 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7189 * stopping on first found. --noprofile turns this off.
7190 * bash also sources ~/.bash_logout on exit.
7191 * If called as sh, skips .bash_XXX files.
7198 * "bash <script>" (which is never interactive (unless -i?))
7199 * sources $BASH_ENV here (without scanning $PATH).
7200 * If called as sh, does the same but with $ENV.
7202 debug_printf("running script '%s'\n", argv[optind]);
7203 G.global_argv = argv + optind;
7204 G.global_argc = argc - optind;
7205 input = xfopen_for_read(argv[optind]);
7206 close_on_exec_on(fileno(input));
7208 parse_and_run_file(input);
7209 #if ENABLE_FEATURE_CLEAN_UP
7215 /* Up to here, shell was non-interactive. Now it may become one.
7216 * NB: don't forget to (re)run init_sigmasks() as needed.
7219 /* A shell is interactive if the '-i' flag was given,
7220 * or if all of the following conditions are met:
7222 * no arguments remaining or the -s flag given
7223 * standard input is a terminal
7224 * standard output is a terminal
7225 * Refer to Posix.2, the description of the 'sh' utility.
7228 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7229 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7230 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7231 if (G_saved_tty_pgrp < 0)
7232 G_saved_tty_pgrp = 0;
7234 /* try to dup stdin to high fd#, >= 255 */
7235 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7236 if (G_interactive_fd < 0) {
7237 /* try to dup to any fd */
7238 G_interactive_fd = dup(STDIN_FILENO);
7239 if (G_interactive_fd < 0) {
7241 G_interactive_fd = 0;
7242 G_saved_tty_pgrp = 0;
7245 // TODO: track & disallow any attempts of user
7246 // to (inadvertently) close/redirect G_interactive_fd
7248 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7249 if (G_interactive_fd) {
7250 close_on_exec_on(G_interactive_fd);
7252 if (G_saved_tty_pgrp) {
7253 /* If we were run as 'hush &', sleep until we are
7254 * in the foreground (tty pgrp == our pgrp).
7255 * If we get started under a job aware app (like bash),
7256 * make sure we are now in charge so we don't fight over
7257 * who gets the foreground */
7259 pid_t shell_pgrp = getpgrp();
7260 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7261 if (G_saved_tty_pgrp == shell_pgrp)
7263 /* send TTIN to ourself (should stop us) */
7264 kill(- shell_pgrp, SIGTTIN);
7268 /* Block some signals */
7271 if (G_saved_tty_pgrp) {
7272 /* Set other signals to restore saved_tty_pgrp */
7273 set_fatal_handlers();
7274 /* Put ourselves in our own process group
7275 * (bash, too, does this only if ctty is available) */
7276 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7277 /* Grab control of the terminal */
7278 tcsetpgrp(G_interactive_fd, getpid());
7280 /* -1 is special - makes xfuncs longjmp, not exit
7281 * (we reset die_sleep = 0 whereever we [v]fork) */
7282 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7286 #elif ENABLE_HUSH_INTERACTIVE
7287 /* No job control compiled in, only prompt/line editing */
7288 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7289 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7290 if (G_interactive_fd < 0) {
7291 /* try to dup to any fd */
7292 G_interactive_fd = dup(STDIN_FILENO);
7293 if (G_interactive_fd < 0)
7295 G_interactive_fd = 0;
7298 if (G_interactive_fd) {
7299 close_on_exec_on(G_interactive_fd);
7303 /* We have interactiveness code disabled */
7307 * if interactive but not a login shell, sources ~/.bashrc
7308 * (--norc turns this off, --rcfile <file> overrides)
7311 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7312 /* note: ash and hush share this string */
7313 printf("\n\n%s %s\n"
7314 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7317 "hush - the humble shell"
7321 parse_and_run_file(stdin);
7324 #if ENABLE_FEATURE_CLEAN_UP
7325 if (G.cwd != bb_msg_unknown)
7327 cur_var = G.top_var->next;
7329 struct variable *tmp = cur_var;
7330 if (!cur_var->max_len)
7331 free(cur_var->varstr);
7332 cur_var = cur_var->next;
7336 hush_exit(G.last_exitcode);
7341 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7342 int lash_main(int argc, char **argv)
7344 bb_error_msg("lash is deprecated, please use hush instead");
7345 return hush_main(argc, argv);
7350 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7351 int msh_main(int argc, char **argv)
7353 //bb_error_msg("msh is deprecated, please use hush instead");
7354 return hush_main(argc, argv);
7362 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7367 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7374 return applet_main_func(argc, argv - argc);
7377 static int FAST_FUNC builtin_test(char **argv)
7379 return run_applet_main(argv, test_main);
7382 static int FAST_FUNC builtin_echo(char **argv)
7384 return run_applet_main(argv, echo_main);
7388 static int FAST_FUNC builtin_printf(char **argv)
7390 return run_applet_main(argv, printf_main);
7394 static char **skip_dash_dash(char **argv)
7397 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7402 static int FAST_FUNC builtin_eval(char **argv)
7404 int rcode = EXIT_SUCCESS;
7406 argv = skip_dash_dash(argv);
7408 char *str = expand_strvec_to_string(argv);
7410 * eval "echo Hi; done" ("done" is syntax error):
7411 * "echo Hi" will not execute too.
7413 parse_and_run_string(str);
7415 rcode = G.last_exitcode;
7420 static int FAST_FUNC builtin_cd(char **argv)
7424 argv = skip_dash_dash(argv);
7426 if (newdir == NULL) {
7427 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7428 * bash says "bash: cd: HOME not set" and does nothing
7431 const char *home = get_local_var_value("HOME");
7432 newdir = home ? home : "/";
7434 if (chdir(newdir)) {
7435 /* Mimic bash message exactly */
7436 bb_perror_msg("cd: %s", newdir);
7437 return EXIT_FAILURE;
7439 /* Read current dir (get_cwd(1) is inside) and set PWD.
7440 * Note: do not enforce exporting. If PWD was unset or unexported,
7441 * set it again, but do not export. bash does the same.
7443 set_pwd_var(/*exp:*/ 0);
7444 return EXIT_SUCCESS;
7447 static int FAST_FUNC builtin_exec(char **argv)
7449 argv = skip_dash_dash(argv);
7450 if (argv[0] == NULL)
7451 return EXIT_SUCCESS; /* bash does this */
7453 /* Careful: we can end up here after [v]fork. Do not restore
7454 * tty pgrp then, only top-level shell process does that */
7455 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7456 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7458 /* TODO: if exec fails, bash does NOT exit! We do.
7459 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7460 * and tcsetpgrp, and this is inherently racy.
7462 execvp_or_die(argv);
7465 static int FAST_FUNC builtin_exit(char **argv)
7467 debug_printf_exec("%s()\n", __func__);
7469 /* interactive bash:
7470 * # trap "echo EEE" EXIT
7473 * There are stopped jobs.
7474 * (if there are _stopped_ jobs, running ones don't count)
7477 # EEE (then bash exits)
7479 * we can use G.exiting = -1 as indicator "last cmd was exit"
7482 /* note: EXIT trap is run by hush_exit */
7483 argv = skip_dash_dash(argv);
7484 if (argv[0] == NULL)
7485 hush_exit(G.last_exitcode);
7486 /* mimic bash: exit 123abc == exit 255 + error msg */
7487 xfunc_error_retval = 255;
7488 /* bash: exit -2 == exit 254, no error msg */
7489 hush_exit(xatoi(argv[0]) & 0xff);
7492 static void print_escaped(const char *s)
7497 const char *p = strchrnul(s, '\'');
7498 /* print 'xxxx', possibly just '' */
7499 printf("'%.*s'", (int)(p - s), s);
7504 /* s points to '; print "'''...'''" */
7506 do putchar('\''); while (*++s == '\'');
7511 #if !ENABLE_HUSH_LOCAL
7512 #define helper_export_local(argv, exp, lvl) \
7513 helper_export_local(argv, exp)
7515 static void helper_export_local(char **argv, int exp, int lvl)
7520 /* So far we do not check that name is valid (TODO?) */
7522 if (strchr(name, '=') == NULL) {
7523 struct variable *var;
7525 var = get_local_var(name);
7526 if (exp == -1) { /* unexporting? */
7527 /* export -n NAME (without =VALUE) */
7529 var->flg_export = 0;
7530 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7532 } /* else: export -n NOT_EXISTING_VAR: no-op */
7535 if (exp == 1) { /* exporting? */
7536 /* export NAME (without =VALUE) */
7538 var->flg_export = 1;
7539 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7540 putenv(var->varstr);
7544 /* Exporting non-existing variable.
7545 * bash does not put it in environment,
7546 * but remembers that it is exported,
7547 * and does put it in env when it is set later.
7548 * We just set it to "" and export. */
7549 /* Or, it's "local NAME" (without =VALUE).
7550 * bash sets the value to "". */
7551 name = xasprintf("%s=", name);
7553 /* (Un)exporting/making local NAME=VALUE */
7554 name = xstrdup(name);
7556 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7560 static int FAST_FUNC builtin_export(char **argv)
7562 unsigned opt_unexport;
7564 #if ENABLE_HUSH_EXPORT_N
7565 /* "!": do not abort on errors */
7566 opt_unexport = getopt32(argv, "!n");
7567 if (opt_unexport == (uint32_t)-1)
7568 return EXIT_FAILURE;
7575 if (argv[0] == NULL) {
7582 /* ash emits: export VAR='VAL'
7583 * bash: declare -x VAR="VAL"
7584 * we follow ash example */
7585 const char *s = *e++;
7586 const char *p = strchr(s, '=');
7588 if (!p) /* wtf? take next variable */
7591 printf("export %.*s", (int)(p - s) + 1, s);
7592 print_escaped(p + 1);
7596 /*fflush_all(); - done after each builtin anyway */
7598 return EXIT_SUCCESS;
7601 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7603 return EXIT_SUCCESS;
7606 #if ENABLE_HUSH_LOCAL
7607 static int FAST_FUNC builtin_local(char **argv)
7609 if (G.func_nest_level == 0) {
7610 bb_error_msg("%s: not in a function", argv[0]);
7611 return EXIT_FAILURE; /* bash compat */
7613 helper_export_local(argv, 0, G.func_nest_level);
7614 return EXIT_SUCCESS;
7618 static int FAST_FUNC builtin_trap(char **argv)
7624 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7629 /* No args: print all trapped */
7630 for (i = 0; i < NSIG; ++i) {
7633 print_escaped(G.traps[i]);
7634 /* note: bash adds "SIG", but only if invoked
7635 * as "bash". If called as "sh", or if set -o posix,
7636 * then it prints short signal names.
7637 * We are printing short names: */
7638 printf(" %s\n", get_signame(i));
7641 /*fflush_all(); - done after each builtin anyway */
7642 return EXIT_SUCCESS;
7646 /* If first arg is a number: reset all specified signals */
7647 sig = bb_strtou(*argv, NULL, 10);
7653 sig = get_signum(*argv++);
7654 if (sig < 0 || sig >= NSIG) {
7656 /* Mimic bash message exactly */
7657 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7662 G.traps[sig] = xstrdup(new_cmd);
7664 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7665 get_signame(sig), sig, G.traps[sig]);
7667 /* There is no signal for 0 (EXIT) */
7672 sigaddset(&G.blocked_set, sig);
7674 /* There was a trap handler, we are removing it
7675 * (if sig has non-DFL handling,
7676 * we don't need to do anything) */
7677 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7679 sigdelset(&G.blocked_set, sig);
7682 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7686 if (!argv[1]) { /* no second arg */
7687 bb_error_msg("trap: invalid arguments");
7688 return EXIT_FAILURE;
7691 /* First arg is "-": reset all specified to default */
7692 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7693 /* Everything else: set arg as signal handler
7694 * (includes "" case, which ignores signal) */
7695 if (argv[0][0] == '-') {
7696 if (argv[0][1] == '\0') { /* "-" */
7697 /* new_cmd remains NULL: "reset these sigs" */
7700 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7703 /* else: "-something", no special meaning */
7708 goto process_sig_list;
7711 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7712 static int FAST_FUNC builtin_type(char **argv)
7714 int ret = EXIT_SUCCESS;
7720 if (0) {} /* make conditional compile easier below */
7721 /*else if (find_alias(*argv))
7722 type = "an alias";*/
7723 #if ENABLE_HUSH_FUNCTIONS
7724 else if (find_function(*argv))
7725 type = "a function";
7727 else if (find_builtin(*argv))
7728 type = "a shell builtin";
7729 else if ((path = find_in_path(*argv)) != NULL)
7732 bb_error_msg("type: %s: not found", *argv);
7737 printf("%s is %s\n", *argv, type);
7745 /* built-in 'fg' and 'bg' handler */
7746 static int FAST_FUNC builtin_fg_bg(char **argv)
7751 if (!G_interactive_fd)
7752 return EXIT_FAILURE;
7754 /* If they gave us no args, assume they want the last backgrounded task */
7756 for (pi = G.job_list; pi; pi = pi->next) {
7757 if (pi->jobid == G.last_jobid) {
7761 bb_error_msg("%s: no current job", argv[0]);
7762 return EXIT_FAILURE;
7764 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7765 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7766 return EXIT_FAILURE;
7768 for (pi = G.job_list; pi; pi = pi->next) {
7769 if (pi->jobid == jobnum) {
7773 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7774 return EXIT_FAILURE;
7776 /* TODO: bash prints a string representation
7777 * of job being foregrounded (like "sleep 1 | cat") */
7778 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7779 /* Put the job into the foreground. */
7780 tcsetpgrp(G_interactive_fd, pi->pgrp);
7783 /* Restart the processes in the job */
7784 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7785 for (i = 0; i < pi->num_cmds; i++) {
7786 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7787 pi->cmds[i].is_stopped = 0;
7789 pi->stopped_cmds = 0;
7791 i = kill(- pi->pgrp, SIGCONT);
7793 if (errno == ESRCH) {
7794 delete_finished_bg_job(pi);
7795 return EXIT_SUCCESS;
7797 bb_perror_msg("kill (SIGCONT)");
7800 if (argv[0][0] == 'f') {
7802 return checkjobs_and_fg_shell(pi);
7804 return EXIT_SUCCESS;
7808 #if ENABLE_HUSH_HELP
7809 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7811 const struct built_in_command *x;
7814 "Built-in commands:\n"
7815 "------------------\n");
7816 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7818 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7821 return EXIT_SUCCESS;
7826 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7829 const char *status_string;
7831 for (job = G.job_list; job; job = job->next) {
7832 if (job->alive_cmds == job->stopped_cmds)
7833 status_string = "Stopped";
7835 status_string = "Running";
7837 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7839 return EXIT_SUCCESS;
7844 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7849 # ifdef M_TRIM_THRESHOLD
7850 /* Optional. Reduces probability of false positives */
7853 /* Crude attempt to find where "free memory" starts,
7854 * sans fragmentation. */
7856 l = (unsigned long)p;
7859 if (l < (unsigned long)p) l = (unsigned long)p;
7862 if (!G.memleak_value)
7863 G.memleak_value = l;
7865 l -= G.memleak_value;
7872 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7877 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7880 return EXIT_SUCCESS;
7883 static int FAST_FUNC builtin_read(char **argv)
7892 /* "!": do not abort on errors.
7893 * Option string must start with "sr" to match BUILTIN_READ_xxx
7895 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7896 if (read_flags == (uint32_t)-1)
7897 return EXIT_FAILURE;
7900 r = shell_builtin_read(set_local_var_from_halves,
7902 get_local_var_value("IFS"), /* can be NULL */
7910 if ((uintptr_t)r > 1) {
7911 bb_error_msg("%s", r);
7912 r = (char*)(uintptr_t)1;
7915 return (uintptr_t)r;
7918 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7919 * built-in 'set' handler
7921 * set [-abCefhmnuvx] [-o option] [argument...]
7922 * set [+abCefhmnuvx] [+o option] [argument...]
7923 * set -- [argument...]
7926 * Implementations shall support the options in both their hyphen and
7927 * plus-sign forms. These options can also be specified as options to sh.
7929 * Write out all variables and their values: set
7930 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7931 * Turn on the -x and -v options: set -xv
7932 * Unset all positional parameters: set --
7933 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7934 * Set the positional parameters to the expansion of x, even if x expands
7935 * with a leading '-' or '+': set -- $x
7937 * So far, we only support "set -- [argument...]" and some of the short names.
7939 static int FAST_FUNC builtin_set(char **argv)
7942 char **pp, **g_argv;
7943 char *arg = *++argv;
7947 for (e = G.top_var; e; e = e->next)
7949 return EXIT_SUCCESS;
7953 if (!strcmp(arg, "--")) {
7957 if (arg[0] != '+' && arg[0] != '-')
7959 for (n = 1; arg[n]; ++n)
7960 if (set_mode(arg[0], arg[n]))
7962 } while ((arg = *++argv) != NULL);
7963 /* Now argv[0] is 1st argument */
7966 return EXIT_SUCCESS;
7969 /* NB: G.global_argv[0] ($0) is never freed/changed */
7970 g_argv = G.global_argv;
7971 if (G.global_args_malloced) {
7977 G.global_args_malloced = 1;
7978 pp = xzalloc(sizeof(pp[0]) * 2);
7979 pp[0] = g_argv[0]; /* retain $0 */
7982 /* This realloc's G.global_argv */
7983 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7990 return EXIT_SUCCESS;
7992 /* Nothing known, so abort */
7994 bb_error_msg("set: %s: invalid option", arg);
7995 return EXIT_FAILURE;
7998 static int FAST_FUNC builtin_shift(char **argv)
8001 argv = skip_dash_dash(argv);
8005 if (n >= 0 && n < G.global_argc) {
8006 if (G.global_args_malloced) {
8009 free(G.global_argv[m++]);
8012 memmove(&G.global_argv[1], &G.global_argv[n+1],
8013 G.global_argc * sizeof(G.global_argv[0]));
8014 return EXIT_SUCCESS;
8016 return EXIT_FAILURE;
8019 static int FAST_FUNC builtin_source(char **argv)
8021 char *arg_path, *filename;
8024 #if ENABLE_HUSH_FUNCTIONS
8028 argv = skip_dash_dash(argv);
8031 /* bash says: "bash: .: filename argument required" */
8032 return 2; /* bash compat */
8035 if (!strchr(filename, '/')) {
8036 arg_path = find_in_path(filename);
8038 filename = arg_path;
8040 input = fopen_or_warn(filename, "r");
8043 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8044 return EXIT_FAILURE;
8046 close_on_exec_on(fileno(input));
8048 #if ENABLE_HUSH_FUNCTIONS
8049 sv_flg = G.flag_return_in_progress;
8050 /* "we are inside sourced file, ok to use return" */
8051 G.flag_return_in_progress = -1;
8053 save_and_replace_G_args(&sv, argv);
8055 parse_and_run_file(input);
8058 restore_G_args(&sv, argv);
8059 #if ENABLE_HUSH_FUNCTIONS
8060 G.flag_return_in_progress = sv_flg;
8063 return G.last_exitcode;
8066 static int FAST_FUNC builtin_umask(char **argv)
8072 argv = skip_dash_dash(argv);
8074 mode_t old_mask = mask;
8077 rc = bb_parse_mode(argv[0], &mask);
8082 * bash: umask: 'q': invalid symbolic mode operator
8083 * bash: umask: 999: octal number out of range
8085 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8090 printf("%04o\n", (unsigned) mask);
8091 /* fall through and restore mask which we set to 0 */
8095 return !rc; /* rc != 0 - success */
8098 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8099 static int FAST_FUNC builtin_unset(char **argv)
8104 /* "!": do not abort on errors */
8105 /* "+": stop at 1st non-option */
8106 opts = getopt32(argv, "!+vf");
8107 if (opts == (unsigned)-1)
8108 return EXIT_FAILURE;
8110 bb_error_msg("unset: -v and -f are exclusive");
8111 return EXIT_FAILURE;
8117 if (!(opts & 2)) { /* not -f */
8118 if (unset_local_var(*argv)) {
8119 /* unset <nonexistent_var> doesn't fail.
8120 * Error is when one tries to unset RO var.
8121 * Message was printed by unset_local_var. */
8125 #if ENABLE_HUSH_FUNCTIONS
8135 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8136 static int FAST_FUNC builtin_wait(char **argv)
8138 int ret = EXIT_SUCCESS;
8141 argv = skip_dash_dash(argv);
8142 if (argv[0] == NULL) {
8143 /* Don't care about wait results */
8144 /* Note 1: must wait until there are no more children */
8145 /* Note 2: must be interruptible */
8147 * $ sleep 3 & sleep 6 & wait
8152 * $ sleep 3 & sleep 6 & wait
8156 * ^C <-- after ~4 sec from keyboard
8159 sigaddset(&G.blocked_set, SIGCHLD);
8160 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8163 if (errno == ECHILD)
8165 /* Wait for SIGCHLD or any other signal of interest */
8166 /* sigtimedwait with infinite timeout: */
8167 sig = sigwaitinfo(&G.blocked_set, NULL);
8169 sig = check_and_run_traps(sig);
8170 if (sig && sig != SIGCHLD) { /* see note 2 */
8176 sigdelset(&G.blocked_set, SIGCHLD);
8177 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8181 /* This is probably buggy wrt interruptible-ness */
8183 pid_t pid = bb_strtou(*argv, NULL, 10);
8185 /* mimic bash message */
8186 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8187 return EXIT_FAILURE;
8189 if (waitpid(pid, &status, 0) == pid) {
8190 if (WIFSIGNALED(status))
8191 ret = 128 + WTERMSIG(status);
8192 else if (WIFEXITED(status))
8193 ret = WEXITSTATUS(status);
8197 bb_perror_msg("wait %s", *argv);
8206 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8207 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8210 def = bb_strtou(argv[1], NULL, 10);
8211 if (errno || def < def_min || argv[2]) {
8212 bb_error_msg("%s: bad arguments", argv[0]);
8220 #if ENABLE_HUSH_LOOPS
8221 static int FAST_FUNC builtin_break(char **argv)
8224 if (G.depth_of_loop == 0) {
8225 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8226 return EXIT_SUCCESS; /* bash compat */
8228 G.flag_break_continue++; /* BC_BREAK = 1 */
8230 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8231 if (depth == UINT_MAX)
8232 G.flag_break_continue = BC_BREAK;
8233 if (G.depth_of_loop < depth)
8234 G.depth_break_continue = G.depth_of_loop;
8236 return EXIT_SUCCESS;
8239 static int FAST_FUNC builtin_continue(char **argv)
8241 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8242 return builtin_break(argv);
8246 #if ENABLE_HUSH_FUNCTIONS
8247 static int FAST_FUNC builtin_return(char **argv)
8251 if (G.flag_return_in_progress != -1) {
8252 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8253 return EXIT_FAILURE; /* bash compat */
8256 G.flag_return_in_progress = 1;
8259 * out of range: wraps around at 256, does not error out
8260 * non-numeric param:
8261 * f() { false; return qwe; }; f; echo $?
8262 * bash: return: qwe: numeric argument required <== we do this
8263 * 255 <== we also do this
8265 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);