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"
93 #include "builtin_read.h"
94 #include "builtin_ulimit.h"
97 #if ENABLE_HUSH_RANDOM_SUPPORT
100 # define CLEAR_RANDOM_T(rnd) ((void)0)
103 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
108 #define LEAK_HUNTING 0
109 #define BUILD_AS_NOMMU 0
110 /* Enable/disable sanity checks. Ok to enable in production,
111 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
112 * Keeping 1 for now even in released versions.
115 /* Slightly bigger (+200 bytes), but faster hush.
116 * So far it only enables a trick with counting SIGCHLDs and forks,
117 * which allows us to do fewer waitpid's.
118 * (we can detect a case where neither forks were done nor SIGCHLDs happened
119 * and therefore waitpid will return the same result as last time)
121 #define ENABLE_HUSH_FAST 0
126 # undef USE_FOR_NOMMU
129 # define USE_FOR_NOMMU(...) __VA_ARGS__
130 # define USE_FOR_MMU(...)
133 #define SKIP_definitions 1
134 #include "applet_tables.h"
135 #undef SKIP_definitions
137 /* STANDALONE does not make sense, and won't compile */
138 # undef CONFIG_FEATURE_SH_STANDALONE
139 # undef ENABLE_FEATURE_SH_STANDALONE
140 # undef IF_FEATURE_SH_STANDALONE
141 # undef IF_NOT_FEATURE_SH_STANDALONE
142 # define ENABLE_FEATURE_SH_STANDALONE 0
143 # define IF_FEATURE_SH_STANDALONE(...)
144 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
147 #if !ENABLE_HUSH_INTERACTIVE
148 # undef ENABLE_FEATURE_EDITING
149 # define ENABLE_FEATURE_EDITING 0
150 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
151 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
154 /* Do we support ANY keywords? */
155 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
156 # define HAS_KEYWORDS 1
157 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
158 # define IF_HAS_NO_KEYWORDS(...)
160 # define HAS_KEYWORDS 0
161 # define IF_HAS_KEYWORDS(...)
162 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
165 /* If you comment out one of these below, it will be #defined later
166 * to perform debug printfs to stderr: */
167 #define debug_printf(...) do {} while (0)
168 /* Finer-grained debug switches */
169 #define debug_printf_parse(...) do {} while (0)
170 #define debug_print_tree(a, b) do {} while (0)
171 #define debug_printf_exec(...) do {} while (0)
172 #define debug_printf_env(...) do {} while (0)
173 #define debug_printf_jobs(...) do {} while (0)
174 #define debug_printf_expand(...) do {} while (0)
175 #define debug_printf_varexp(...) do {} while (0)
176 #define debug_printf_glob(...) do {} while (0)
177 #define debug_printf_list(...) do {} while (0)
178 #define debug_printf_subst(...) do {} while (0)
179 #define debug_printf_clean(...) do {} while (0)
181 #define ERR_PTR ((void*)(long)1)
183 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
185 #define _SPECIAL_VARS_STR "_*@$!?#"
186 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
187 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
189 #define SPECIAL_VAR_SYMBOL 3
193 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
195 /* This supports saving pointers malloced in vfork child,
196 * to be freed in the parent.
199 typedef struct nommu_save_t {
201 struct variable *old_vars;
203 char **argv_from_re_execing;
207 typedef enum reserved_style {
216 #if ENABLE_HUSH_LOOPS
223 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
228 /* three pseudo-keywords support contrived "case" syntax: */
229 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
230 RES_MATCH , /* "word)" */
231 RES_CASE_BODY, /* "this command is inside CASE" */
238 typedef struct o_string {
240 int length; /* position where data is appended */
242 /* Protect newly added chars against globbing
243 * (by prepending \ to *, ?, [, \) */
246 /* At least some part of the string was inside '' or "",
247 * possibly empty one: word"", wo''rd etc. */
249 smallint has_empty_slot;
250 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
253 MAYBE_ASSIGNMENT = 0,
254 DEFINITELY_ASSIGNMENT = 1,
256 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
258 /* Used for initialization: o_string foo = NULL_O_STRING; */
259 #define NULL_O_STRING { NULL }
261 /* I can almost use ordinary FILE*. Is open_memstream() universally
262 * available? Where is it documented? */
263 typedef struct in_str {
265 /* eof_flag=1: last char in ->p is really an EOF */
266 char eof_flag; /* meaningless if ->p == NULL */
268 #if ENABLE_HUSH_INTERACTIVE
270 smallint promptmode; /* 0: PS1, 1: PS2 */
273 int (*get) (struct in_str *) FAST_FUNC;
274 int (*peek) (struct in_str *) FAST_FUNC;
276 #define i_getch(input) ((input)->get(input))
277 #define i_peek(input) ((input)->peek(input))
279 /* The descrip member of this structure is only used to make
280 * debugging output pretty */
281 static const struct {
283 signed char default_fd;
286 { O_RDONLY, 0, "<" },
287 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
288 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
289 { O_CREAT|O_RDWR, 1, "<>" },
290 { O_RDONLY, 0, "<<" },
291 /* Should not be needed. Bogus default_fd helps in debugging */
292 /* { O_RDONLY, 77, "<<" }, */
295 struct redir_struct {
296 struct redir_struct *next;
297 char *rd_filename; /* filename */
298 int rd_fd; /* fd to redirect */
299 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
301 smallint rd_type; /* (enum redir_type) */
302 /* note: for heredocs, rd_filename contains heredoc delimiter,
303 * and subsequently heredoc itself; and rd_dup is a bitmask:
304 * bit 0: do we need to trim leading tabs?
305 * bit 1: is heredoc quoted (<<'delim' syntax) ?
308 typedef enum redir_type {
310 REDIRECT_OVERWRITE = 1,
313 REDIRECT_HEREDOC = 4,
314 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
317 REDIRFD_SYNTAX_ERR = -2,
318 REDIRFD_TO_FILE = -1,
319 /* otherwise, rd_fd is redirected to rd_dup */
321 HEREDOC_SKIPTABS = 1,
327 pid_t pid; /* 0 if exited */
328 int assignment_cnt; /* how many argv[i] are assignments? */
329 smallint is_stopped; /* is the command currently running? */
330 smallint cmd_type; /* CMD_xxx */
332 #define CMD_SUBSHELL 1
334 /* used for "[[ EXPR ]]" */
335 #if ENABLE_HUSH_BASH_COMPAT
336 # define CMD_SINGLEWORD_NOGLOB 2
339 /* used for "export noglob=* glob* a=`echo a b`" */
340 //#define CMD_SINGLEWORD_NOGLOB_COND 3
341 // It is hard to implement correctly, it adds significant amounts of tricky code,
342 // and all this is only useful for really obscure export statements
343 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
344 // guards the code which implements it, but I have doubts it works
345 // in all cases (especially with mixed globbed/non-globbed arguments)
347 #if ENABLE_HUSH_FUNCTIONS
348 # define CMD_FUNCDEF 3
351 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
354 char *group_as_string;
356 #if ENABLE_HUSH_FUNCTIONS
357 struct function *child_func;
358 /* This field is used to prevent a bug here:
359 * while...do f1() {a;}; f1; f1() {b;}; f1; done
360 * When we execute "f1() {a;}" cmd, we create new function and clear
361 * cmd->group, cmd->group_as_string, cmd->argv[0].
362 * When we execute "f1() {b;}", we notice that f1 exists,
363 * and that its "parent cmd" struct is still "alive",
364 * we put those fields back into cmd->xxx
365 * (struct function has ->parent_cmd ptr to facilitate that).
366 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
367 * Without this trick, loop would execute a;b;b;b;...
368 * instead of correct sequence a;b;a;b;...
369 * When command is freed, it severs the link
370 * (sets ->child_func->parent_cmd to NULL).
373 char **argv; /* command name and arguments */
374 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
375 * and on execution these are substituted with their values.
376 * Substitution can make _several_ words out of one argv[n]!
377 * Example: argv[0]=='.^C*^C.' here: echo .$*.
378 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
380 struct redir_struct *redirects; /* I/O redirections */
382 /* Is there anything in this command at all? */
383 #define IS_NULL_CMD(cmd) \
384 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
389 int num_cmds; /* total number of commands in pipe */
390 int alive_cmds; /* number of commands running (not exited) */
391 int stopped_cmds; /* number of commands alive, but stopped */
393 int jobid; /* job number */
394 pid_t pgrp; /* process group ID for the job */
395 char *cmdtext; /* name of job */
397 struct command *cmds; /* array of commands in pipe */
398 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
399 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
400 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
402 typedef enum pipe_style {
408 /* Is there anything in this pipe at all? */
409 #define IS_NULL_PIPE(pi) \
410 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
412 /* This holds pointers to the various results of parsing */
413 struct parse_context {
414 /* linked list of pipes */
415 struct pipe *list_head;
416 /* last pipe (being constructed right now) */
418 /* last command in pipe (being constructed right now) */
419 struct command *command;
420 /* last redirect in command->redirects list */
421 struct redir_struct *pending_redirect;
427 smallint ctx_inverted; /* "! cmd | cmd" */
429 smallint ctx_dsemicolon; /* ";;" seen */
431 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
433 /* group we are enclosed in:
434 * example: "if pipe1; pipe2; then pipe3; fi"
435 * when we see "if" or "then", we malloc and copy current context,
436 * and make ->stack point to it. then we parse pipeN.
437 * when closing "then" / fi" / whatever is found,
438 * we move list_head into ->stack->command->group,
439 * copy ->stack into current context, and delete ->stack.
440 * (parsing of { list } and ( list ) doesn't use this method)
442 struct parse_context *stack;
446 /* On program start, environ points to initial environment.
447 * putenv adds new pointers into it, unsetenv removes them.
448 * Neither of these (de)allocates the strings.
449 * setenv allocates new strings in malloc space and does putenv,
450 * and thus setenv is unusable (leaky) for shell's purposes */
451 #define setenv(...) setenv_is_leaky_dont_use()
453 struct variable *next;
454 char *varstr; /* points to "name=" portion */
455 #if ENABLE_HUSH_LOCAL
456 unsigned func_nest_level;
458 int max_len; /* if > 0, name is part of initial env; else name is malloced */
459 smallint flg_export; /* putenv should be done on this var */
460 smallint flg_read_only;
468 #if ENABLE_HUSH_FUNCTIONS
470 struct function *next;
472 struct command *parent_cmd;
475 char *body_as_string;
481 /* "Globals" within this file */
482 /* Sorted roughly by size (smaller offsets == smaller code) */
484 /* interactive_fd != 0 means we are an interactive shell.
485 * If we are, then saved_tty_pgrp can also be != 0, meaning
486 * that controlling tty is available. With saved_tty_pgrp == 0,
487 * job control still works, but terminal signals
488 * (^C, ^Z, ^Y, ^\) won't work at all, and background
489 * process groups can only be created with "cmd &".
490 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
491 * to give tty to the foreground process group,
492 * and will take it back when the group is stopped (^Z)
495 #if ENABLE_HUSH_INTERACTIVE
496 /* 'interactive_fd' is a fd# open to ctty, if we have one
497 * _AND_ if we decided to act interactively */
501 # define G_interactive_fd (G.interactive_fd)
503 # define G_interactive_fd 0
505 #if ENABLE_FEATURE_EDITING
506 line_input_t *line_input_state;
511 #if ENABLE_HUSH_RANDOM_SUPPORT
517 pid_t saved_tty_pgrp;
518 struct pipe *job_list;
519 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
521 # define G_saved_tty_pgrp 0
523 smallint flag_SIGINT;
524 #if ENABLE_HUSH_LOOPS
525 smallint flag_break_continue;
527 #if ENABLE_HUSH_FUNCTIONS
528 /* 0: outside of a function (or sourced file)
529 * -1: inside of a function, ok to use return builtin
530 * 1: return is invoked, skip all till end of func
532 smallint flag_return_in_progress;
535 smallint exiting; /* used to prevent EXIT trap recursion */
536 /* These four support $?, $#, and $1 */
537 smalluint last_exitcode;
538 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
539 smalluint global_args_malloced;
540 smalluint inherited_set_is_saved;
541 /* how many non-NULL argv's we have. NB: $# + 1 */
545 char *argv0_for_re_execing;
547 #if ENABLE_HUSH_LOOPS
548 unsigned depth_break_continue;
549 unsigned depth_of_loop;
553 struct variable *top_var; /* = &G.shell_ver (set in main()) */
554 struct variable shell_ver;
555 #if ENABLE_HUSH_FUNCTIONS
556 struct function *top_func;
557 # if ENABLE_HUSH_LOCAL
558 struct variable **shadowed_vars_pp;
559 unsigned func_nest_level;
562 /* Signal and trap handling */
564 unsigned count_SIGCHLD;
565 unsigned handled_SIGCHLD;
566 smallint we_have_children;
568 /* which signals have non-DFL handler (even with no traps set)? */
569 unsigned non_DFL_mask;
570 char **traps; /* char *traps[NSIG] */
571 sigset_t blocked_set;
572 sigset_t inherited_set;
574 unsigned long memleak_value;
577 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
579 #define G (*ptr_to_globals)
580 /* Not #defining name to G.name - this quickly gets unwieldy
581 * (too many defines). Also, I actually prefer to see when a variable
582 * is global, thus "G." prefix is a useful hint */
583 #define INIT_G() do { \
584 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
588 /* Function prototypes for builtins */
589 static int builtin_cd(char **argv) FAST_FUNC;
590 static int builtin_echo(char **argv) FAST_FUNC;
591 static int builtin_eval(char **argv) FAST_FUNC;
592 static int builtin_exec(char **argv) FAST_FUNC;
593 static int builtin_exit(char **argv) FAST_FUNC;
594 static int builtin_export(char **argv) FAST_FUNC;
596 static int builtin_fg_bg(char **argv) FAST_FUNC;
597 static int builtin_jobs(char **argv) FAST_FUNC;
600 static int builtin_help(char **argv) FAST_FUNC;
602 #if ENABLE_HUSH_LOCAL
603 static int builtin_local(char **argv) FAST_FUNC;
606 static int builtin_memleak(char **argv) FAST_FUNC;
609 static int builtin_printf(char **argv) FAST_FUNC;
611 static int builtin_pwd(char **argv) FAST_FUNC;
612 static int builtin_read(char **argv) FAST_FUNC;
613 static int builtin_set(char **argv) FAST_FUNC;
614 static int builtin_shift(char **argv) FAST_FUNC;
615 static int builtin_source(char **argv) FAST_FUNC;
616 static int builtin_test(char **argv) FAST_FUNC;
617 static int builtin_trap(char **argv) FAST_FUNC;
618 static int builtin_type(char **argv) FAST_FUNC;
619 static int builtin_true(char **argv) FAST_FUNC;
620 static int builtin_umask(char **argv) FAST_FUNC;
621 static int builtin_unset(char **argv) FAST_FUNC;
622 static int builtin_wait(char **argv) FAST_FUNC;
623 #if ENABLE_HUSH_LOOPS
624 static int builtin_break(char **argv) FAST_FUNC;
625 static int builtin_continue(char **argv) FAST_FUNC;
627 #if ENABLE_HUSH_FUNCTIONS
628 static int builtin_return(char **argv) FAST_FUNC;
631 /* Table of built-in functions. They can be forked or not, depending on
632 * context: within pipes, they fork. As simple commands, they do not.
633 * When used in non-forking context, they can change global variables
634 * in the parent shell process. If forked, of course they cannot.
635 * For example, 'unset foo | whatever' will parse and run, but foo will
636 * still be set at the end. */
637 struct built_in_command {
639 int (*b_function)(char **argv) FAST_FUNC;
642 # define BLTIN(cmd, func, help) { cmd, func, help }
644 # define BLTIN(cmd, func, help) { cmd, func }
648 static const struct built_in_command bltins1[] = {
649 BLTIN("." , builtin_source , "Run commands in a file"),
650 BLTIN(":" , builtin_true , NULL),
652 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
654 #if ENABLE_HUSH_LOOPS
655 BLTIN("break" , builtin_break , "Exit from a loop"),
657 BLTIN("cd" , builtin_cd , "Change directory"),
658 #if ENABLE_HUSH_LOOPS
659 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
661 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
662 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
663 BLTIN("exit" , builtin_exit , "Exit"),
664 BLTIN("export" , builtin_export , "Set environment variables"),
666 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
669 BLTIN("help" , builtin_help , NULL),
672 BLTIN("jobs" , builtin_jobs , "List jobs"),
674 #if ENABLE_HUSH_LOCAL
675 BLTIN("local" , builtin_local , "Set local variables"),
678 BLTIN("memleak" , builtin_memleak , NULL),
680 BLTIN("read" , builtin_read , "Input into variable"),
681 #if ENABLE_HUSH_FUNCTIONS
682 BLTIN("return" , builtin_return , "Return from a function"),
684 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
685 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
686 #if ENABLE_HUSH_BASH_COMPAT
687 BLTIN("source" , builtin_source , "Run commands in a file"),
689 BLTIN("trap" , builtin_trap , "Trap signals"),
690 BLTIN("type" , builtin_type , "Show command type"),
691 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
692 BLTIN("umask" , builtin_umask , "Set file creation mask"),
693 BLTIN("unset" , builtin_unset , "Unset variables"),
694 BLTIN("wait" , builtin_wait , "Wait for process"),
696 /* For now, echo and test are unconditionally enabled.
697 * Maybe make it configurable? */
698 static const struct built_in_command bltins2[] = {
699 BLTIN("[" , builtin_test , NULL),
700 BLTIN("echo" , builtin_echo , NULL),
702 BLTIN("printf" , builtin_printf , NULL),
704 BLTIN("pwd" , builtin_pwd , NULL),
705 BLTIN("test" , builtin_test , NULL),
712 /* prevent disasters with G.debug_indent < 0 */
713 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
714 # define debug_enter() (G.debug_indent++)
715 # define debug_leave() (G.debug_indent--)
717 # define indent() ((void)0)
718 # define debug_enter() ((void)0)
719 # define debug_leave() ((void)0)
723 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
726 #ifndef debug_printf_parse
727 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
730 #ifndef debug_printf_exec
731 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
734 #ifndef debug_printf_env
735 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
738 #ifndef debug_printf_jobs
739 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
740 # define DEBUG_JOBS 1
742 # define DEBUG_JOBS 0
745 #ifndef debug_printf_expand
746 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
747 # define DEBUG_EXPAND 1
749 # define DEBUG_EXPAND 0
752 #ifndef debug_printf_varexp
753 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
756 #ifndef debug_printf_glob
757 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
758 # define DEBUG_GLOB 1
760 # define DEBUG_GLOB 0
763 #ifndef debug_printf_list
764 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
767 #ifndef debug_printf_subst
768 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
771 #ifndef debug_printf_clean
772 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
773 # define DEBUG_CLEAN 1
775 # define DEBUG_CLEAN 0
779 static void debug_print_strings(const char *prefix, char **vv)
782 fprintf(stderr, "%s:\n", prefix);
784 fprintf(stderr, " '%s'\n", *vv++);
787 # define debug_print_strings(prefix, vv) ((void)0)
791 /* Leak hunting. Use hush_leaktool.sh for post-processing.
794 static void *xxmalloc(int lineno, size_t size)
796 void *ptr = xmalloc((size + 0xff) & ~0xff);
797 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
800 static void *xxrealloc(int lineno, void *ptr, size_t size)
802 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
803 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
806 static char *xxstrdup(int lineno, const char *str)
808 char *ptr = xstrdup(str);
809 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
812 static void xxfree(void *ptr)
814 fdprintf(2, "free %p\n", ptr);
817 #define xmalloc(s) xxmalloc(__LINE__, s)
818 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
819 #define xstrdup(s) xxstrdup(__LINE__, s)
820 #define free(p) xxfree(p)
824 /* Syntax and runtime errors. They always abort scripts.
825 * In interactive use they usually discard unparsed and/or unexecuted commands
826 * and return to the prompt.
827 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
830 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
831 # define syntax_error(lineno, msg) syntax_error(msg)
832 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
833 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
834 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
835 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
838 static void die_if_script(unsigned lineno, const char *fmt, ...)
843 bb_error_msg("hush.c:%u", lineno);
846 bb_verror_msg(fmt, p, NULL);
848 if (!G_interactive_fd)
852 static void syntax_error(unsigned lineno, const char *msg)
855 die_if_script(lineno, "syntax error: %s", msg);
857 die_if_script(lineno, "syntax error", NULL);
860 static void syntax_error_at(unsigned lineno, const char *msg)
862 die_if_script(lineno, "syntax error at '%s'", msg);
865 static void syntax_error_unterm_str(unsigned lineno, const char *s)
867 die_if_script(lineno, "syntax error: unterminated %s", s);
870 /* It so happens that all such cases are totally fatal
871 * even if shell is interactive: EOF while looking for closing
872 * delimiter. There is nowhere to read stuff from after that,
873 * it's EOF! The only choice is to terminate.
875 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
876 static void syntax_error_unterm_ch(unsigned lineno, char ch)
878 char msg[2] = { ch, '\0' };
879 syntax_error_unterm_str(lineno, msg);
883 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
888 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
892 # undef die_if_script
894 # undef syntax_error_at
895 # undef syntax_error_unterm_ch
896 # undef syntax_error_unterm_str
897 # undef syntax_error_unexpected_ch
899 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
900 # define syntax_error(msg) syntax_error(__LINE__, msg)
901 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
902 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
903 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
904 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
908 #if ENABLE_HUSH_INTERACTIVE
909 static void cmdedit_update_prompt(void);
911 # define cmdedit_update_prompt() ((void)0)
917 /* Replace each \x with x in place, return ptr past NUL. */
918 static char *unbackslash(char *src)
920 char *dst = src = strchrnul(src, '\\');
924 if ((*dst++ = *src++) == '\0')
930 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
951 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
952 v[count1 + count2] = NULL;
955 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
959 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
961 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
962 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
965 #define add_strings_to_strings(strings, add, need_to_dup) \
966 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
969 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
970 static char **add_string_to_strings(char **strings, char *add)
975 return add_strings_to_strings(strings, v, /*dup:*/ 0);
978 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
980 char **ptr = add_string_to_strings(strings, add);
981 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
984 #define add_string_to_strings(strings, add) \
985 xx_add_string_to_strings(__LINE__, strings, add)
988 static void free_strings(char **strings)
1003 /* Helpers for setting new $n and restoring them back
1005 typedef struct save_arg_t {
1009 smallint sv_g_malloced;
1012 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1016 sv->sv_argv0 = argv[0];
1017 sv->sv_g_argv = G.global_argv;
1018 sv->sv_g_argc = G.global_argc;
1019 sv->sv_g_malloced = G.global_args_malloced;
1021 argv[0] = G.global_argv[0]; /* retain $0 */
1022 G.global_argv = argv;
1023 G.global_args_malloced = 0;
1031 static void restore_G_args(save_arg_t *sv, char **argv)
1035 if (G.global_args_malloced) {
1036 /* someone ran "set -- arg1 arg2 ...", undo */
1038 while (*++pp) /* note: does not free $0 */
1040 free(G.global_argv);
1042 argv[0] = sv->sv_argv0;
1043 G.global_argv = sv->sv_g_argv;
1044 G.global_argc = sv->sv_g_argc;
1045 G.global_args_malloced = sv->sv_g_malloced;
1049 /* Basic theory of signal handling in shell
1050 * ========================================
1051 * This does not describe what hush does, rather, it is current understanding
1052 * what it _should_ do. If it doesn't, it's a bug.
1053 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1055 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1056 * is finished or backgrounded. It is the same in interactive and
1057 * non-interactive shells, and is the same regardless of whether
1058 * a user trap handler is installed or a shell special one is in effect.
1059 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1060 * backgrounds (i.e. stops) or kills all members of currently running
1063 * Wait builtin in interruptible by signals for which user trap is set
1064 * or by SIGINT in interactive shell.
1066 * Trap handlers will execute even within trap handlers. (right?)
1068 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1069 * except for handlers set to '' (empty string).
1071 * If job control is off, backgrounded commands ("cmd &")
1072 * have SIGINT, SIGQUIT set to SIG_IGN.
1074 * Commands which are run in command substitution ("`cmd`")
1075 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1077 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1078 * by the shell from its parent.
1080 * Signals which differ from SIG_DFL action
1081 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1084 * SIGTERM (interactive): ignore
1085 * SIGHUP (interactive):
1086 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1087 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1088 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1089 * that all pipe members are stopped. Try this in bash:
1090 * while :; do :; done - ^Z does not background it
1091 * (while :; do :; done) - ^Z backgrounds it
1092 * SIGINT (interactive): wait for last pipe, ignore the rest
1093 * of the command line, show prompt. NB: ^C does not send SIGINT
1094 * to interactive shell while shell is waiting for a pipe,
1095 * since shell is bg'ed (is not in foreground process group).
1096 * Example 1: this waits 5 sec, but does not execute ls:
1097 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1098 * Example 2: this does not wait and does not execute ls:
1099 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1100 * Example 3: this does not wait 5 sec, but executes ls:
1101 * "sleep 5; ls -l" + press ^C
1103 * (What happens to signals which are IGN on shell start?)
1104 * (What happens with signal mask on shell start?)
1106 * Implementation in hush
1107 * ======================
1108 * We use in-kernel pending signal mask to determine which signals were sent.
1109 * We block all signals which we don't want to take action immediately,
1110 * i.e. we block all signals which need to have special handling as described
1111 * above, and all signals which have traps set.
1112 * After each pipe execution, we extract any pending signals via sigtimedwait()
1115 * unsigned non_DFL_mask: a mask of such "special" signals
1116 * sigset_t blocked_set: current blocked signal set
1119 * clear bit in blocked_set unless it is also in non_DFL_mask
1120 * "trap 'cmd' SIGxxx":
1121 * set bit in blocked_set (even if 'cmd' is '')
1122 * after [v]fork, if we plan to be a shell:
1123 * unblock signals with special interactive handling
1124 * (child shell is not interactive),
1125 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1126 * after [v]fork, if we plan to exec:
1127 * POSIX says fork clears pending signal mask in child - no need to clear it.
1128 * Restore blocked signal set to one inherited by shell just prior to exec.
1130 * Note: as a result, we do not use signal handlers much. The only uses
1131 * are to count SIGCHLDs
1132 * and to restore tty pgrp on signal-induced exit.
1135 * Standard says "When a subshell is entered, traps that are not being ignored
1136 * are set to the default actions". bash interprets it so that traps which
1137 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1140 SPECIAL_INTERACTIVE_SIGS = 0
1145 SPECIAL_JOB_SIGS = 0
1153 #if ENABLE_HUSH_FAST
1154 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1157 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1163 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1164 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1165 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1166 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1168 /* Restores tty foreground process group, and exits.
1169 * May be called as signal handler for fatal signal
1170 * (will resend signal to itself, producing correct exit state)
1171 * or called directly with -EXITCODE.
1172 * We also call it if xfunc is exiting. */
1173 static void sigexit(int sig) NORETURN;
1174 static void sigexit(int sig)
1176 /* Disable all signals: job control, SIGPIPE, etc. */
1177 sigprocmask_allsigs(SIG_BLOCK);
1179 /* Careful: we can end up here after [v]fork. Do not restore
1180 * tty pgrp then, only top-level shell process does that */
1181 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1182 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1184 /* Not a signal, just exit */
1188 kill_myself_with_sig(sig); /* does not return */
1192 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1193 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1197 /* Restores tty foreground process group, and exits. */
1198 static void hush_exit(int exitcode) NORETURN;
1199 static void hush_exit(int exitcode)
1201 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1202 /* Prevent recursion:
1203 * trap "echo Hi; exit" EXIT; exit
1205 char *argv[] = { NULL, G.traps[0], NULL };
1214 sigexit(- (exitcode & 0xff));
1220 static int check_and_run_traps(int sig)
1222 static const struct timespec zero_timespec = { 0, 0 };
1223 smalluint save_rcode;
1229 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1234 if (G.traps && G.traps[sig]) {
1235 if (G.traps[sig][0]) {
1236 /* We have user-defined handler */
1237 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1238 save_rcode = G.last_exitcode;
1241 G.last_exitcode = save_rcode;
1242 } /* else: "" trap, ignoring signal */
1245 /* not a trap: special action */
1247 #if ENABLE_HUSH_FAST
1250 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1254 /* Builtin was ^C'ed, make it look prettier: */
1261 /* bash is observed to signal whole process groups,
1262 * not individual processes */
1263 for (job = G.job_list; job; job = job->next) {
1266 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1267 if (kill(- job->pgrp, SIGHUP) == 0)
1268 kill(- job->pgrp, SIGCONT);
1273 default: /* ignored: */
1274 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1282 static const char *get_cwd(int force)
1284 if (force || G.cwd == NULL) {
1285 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1286 * we must not try to free(bb_msg_unknown) */
1287 if (G.cwd == bb_msg_unknown)
1289 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1291 G.cwd = bb_msg_unknown;
1298 * Shell and environment variable support
1300 static struct variable **get_ptr_to_local_var(const char *name)
1302 struct variable **pp;
1303 struct variable *cur;
1308 while ((cur = *pp) != NULL) {
1309 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1316 static struct variable *get_local_var(const char *name)
1318 struct variable **pp = get_ptr_to_local_var(name);
1324 static const char* FAST_FUNC get_local_var_value(const char *name)
1326 struct variable **pp = get_ptr_to_local_var(name);
1328 return strchr((*pp)->varstr, '=') + 1;
1329 if (strcmp(name, "PPID") == 0)
1330 return utoa(G.root_ppid);
1331 // bash compat: UID? EUID?
1332 #if ENABLE_HUSH_RANDOM_SUPPORT
1333 if (strcmp(name, "RANDOM") == 0) {
1334 return utoa(next_random(&G.random_gen));
1340 /* str holds "NAME=VAL" and is expected to be malloced.
1341 * We take ownership of it.
1343 * 0: do not change export flag
1344 * (if creating new variable, flag will be 0)
1345 * 1: set export flag and putenv the variable
1346 * -1: clear export flag and unsetenv the variable
1347 * flg_read_only is set only when we handle -R var=val
1349 #if !BB_MMU && ENABLE_HUSH_LOCAL
1350 /* all params are used */
1351 #elif BB_MMU && ENABLE_HUSH_LOCAL
1352 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1353 set_local_var(str, flg_export, local_lvl)
1354 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1355 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1356 set_local_var(str, flg_export)
1357 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1358 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1359 set_local_var(str, flg_export, flg_read_only)
1361 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1363 struct variable **var_pp;
1364 struct variable *cur;
1368 eq_sign = strchr(str, '=');
1369 if (!eq_sign) { /* not expected to ever happen? */
1374 name_len = eq_sign - str + 1; /* including '=' */
1375 var_pp = &G.top_var;
1376 while ((cur = *var_pp) != NULL) {
1377 if (strncmp(cur->varstr, str, name_len) != 0) {
1378 var_pp = &cur->next;
1381 /* We found an existing var with this name */
1382 if (cur->flg_read_only) {
1386 bb_error_msg("%s: readonly variable", str);
1390 if (flg_export == -1) { // "&& cur->flg_export" ?
1391 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1396 #if ENABLE_HUSH_LOCAL
1397 if (cur->func_nest_level < local_lvl) {
1398 /* New variable is declared as local,
1399 * and existing one is global, or local
1400 * from enclosing function.
1401 * Remove and save old one: */
1402 *var_pp = cur->next;
1403 cur->next = *G.shadowed_vars_pp;
1404 *G.shadowed_vars_pp = cur;
1405 /* bash 3.2.33(1) and exported vars:
1407 * # f() { local z=a; env | grep ^z; }
1413 if (cur->flg_export)
1418 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1423 if (cur->max_len != 0) {
1424 if (cur->max_len >= strlen(str)) {
1425 /* This one is from startup env, reuse space */
1426 strcpy(cur->varstr, str);
1430 /* max_len == 0 signifies "malloced" var, which we can
1431 * (and has to) free */
1435 goto set_str_and_exp;
1438 /* Not found - create new variable struct */
1439 cur = xzalloc(sizeof(*cur));
1440 #if ENABLE_HUSH_LOCAL
1441 cur->func_nest_level = local_lvl;
1443 cur->next = *var_pp;
1449 cur->flg_read_only = flg_read_only;
1452 if (flg_export == 1)
1453 cur->flg_export = 1;
1454 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1455 cmdedit_update_prompt();
1456 if (cur->flg_export) {
1457 if (flg_export == -1) {
1458 cur->flg_export = 0;
1459 /* unsetenv was already done */
1461 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1462 return putenv(cur->varstr);
1468 /* Used at startup and after each cd */
1469 static void set_pwd_var(int exp)
1471 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1472 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1475 static int unset_local_var_len(const char *name, int name_len)
1477 struct variable *cur;
1478 struct variable **var_pp;
1481 return EXIT_SUCCESS;
1482 var_pp = &G.top_var;
1483 while ((cur = *var_pp) != NULL) {
1484 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1485 if (cur->flg_read_only) {
1486 bb_error_msg("%s: readonly variable", name);
1487 return EXIT_FAILURE;
1489 *var_pp = cur->next;
1490 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1491 bb_unsetenv(cur->varstr);
1492 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1493 cmdedit_update_prompt();
1497 return EXIT_SUCCESS;
1499 var_pp = &cur->next;
1501 return EXIT_SUCCESS;
1504 static int unset_local_var(const char *name)
1506 return unset_local_var_len(name, strlen(name));
1509 static void unset_vars(char **strings)
1517 const char *eq = strchrnul(*v, '=');
1518 unset_local_var_len(*v, (int)(eq - *v));
1524 #if ENABLE_SH_MATH_SUPPORT
1525 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1526 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1527 static char* FAST_FUNC endofname(const char *name)
1535 if (!is_in_name(*p))
1542 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1544 char *var = xasprintf("%s=%s", name, val);
1545 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1550 * Helpers for "var1=val1 var2=val2 cmd" feature
1552 static void add_vars(struct variable *var)
1554 struct variable *next;
1558 var->next = G.top_var;
1560 if (var->flg_export) {
1561 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1562 putenv(var->varstr);
1564 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1570 static struct variable *set_vars_and_save_old(char **strings)
1573 struct variable *old = NULL;
1579 struct variable *var_p;
1580 struct variable **var_pp;
1583 eq = strchr(*s, '=');
1586 var_pp = get_ptr_to_local_var(*s);
1589 /* Remove variable from global linked list */
1591 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1592 *var_pp = var_p->next;
1593 /* Add it to returned list */
1597 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1608 static int FAST_FUNC static_get(struct in_str *i)
1617 static int FAST_FUNC static_peek(struct in_str *i)
1622 #if ENABLE_HUSH_INTERACTIVE
1624 static void cmdedit_update_prompt(void)
1626 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1627 G.PS1 = get_local_var_value("PS1");
1630 G.PS2 = get_local_var_value("PS2");
1638 static const char* setup_prompt_string(int promptmode)
1640 const char *prompt_str;
1641 debug_printf("setup_prompt_string %d ", promptmode);
1642 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1643 /* Set up the prompt */
1644 if (promptmode == 0) { /* PS1 */
1646 /* bash uses $PWD value, even if it is set by user.
1647 * It uses current dir only if PWD is unset.
1648 * We always use current dir. */
1649 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1654 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1655 debug_printf("result '%s'\n", prompt_str);
1659 static void get_user_input(struct in_str *i)
1662 const char *prompt_str;
1664 prompt_str = setup_prompt_string(i->promptmode);
1665 #if ENABLE_FEATURE_EDITING
1666 /* Enable command line editing only while a command line
1667 * is actually being read */
1670 /* buglet: SIGINT will not make new prompt to appear _at once_,
1671 * only after <Enter>. (^C will work) */
1672 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1673 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1674 check_and_run_traps(0);
1675 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1676 i->eof_flag = (r < 0);
1677 if (i->eof_flag) { /* EOF/error detected */
1678 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1679 G.user_input_buf[1] = '\0';
1684 fputs(prompt_str, stdout);
1686 G.user_input_buf[0] = r = fgetc(i->file);
1687 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1688 //do we need check_and_run_traps(0)? (maybe only if stdin)
1689 } while (G.flag_SIGINT);
1690 i->eof_flag = (r == EOF);
1692 i->p = G.user_input_buf;
1695 #endif /* INTERACTIVE */
1697 /* This is the magic location that prints prompts
1698 * and gets data back from the user */
1699 static int FAST_FUNC file_get(struct in_str *i)
1703 /* If there is data waiting, eat it up */
1704 if (i->p && *i->p) {
1705 #if ENABLE_HUSH_INTERACTIVE
1709 if (i->eof_flag && !*i->p)
1711 /* note: ch is never NUL */
1713 /* need to double check i->file because we might be doing something
1714 * more complicated by now, like sourcing or substituting. */
1715 #if ENABLE_HUSH_INTERACTIVE
1716 if (G_interactive_fd && i->promptme && i->file == stdin) {
1719 } while (!*i->p); /* need non-empty line */
1720 i->promptmode = 1; /* PS2 */
1725 do ch = fgetc(i->file); while (ch == '\0');
1727 debug_printf("file_get: got '%c' %d\n", ch, ch);
1728 #if ENABLE_HUSH_INTERACTIVE
1735 /* All callers guarantee this routine will never
1736 * be used right after a newline, so prompting is not needed.
1738 static int FAST_FUNC file_peek(struct in_str *i)
1741 if (i->p && *i->p) {
1742 if (i->eof_flag && !i->p[1])
1745 /* note: ch is never NUL */
1747 do ch = fgetc(i->file); while (ch == '\0');
1748 i->eof_flag = (ch == EOF);
1749 i->peek_buf[0] = ch;
1750 i->peek_buf[1] = '\0';
1752 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1756 static void setup_file_in_str(struct in_str *i, FILE *f)
1758 i->peek = file_peek;
1760 #if ENABLE_HUSH_INTERACTIVE
1762 i->promptmode = 0; /* PS1 */
1768 static void setup_string_in_str(struct in_str *i, const char *s)
1770 i->peek = static_peek;
1771 i->get = static_get;
1772 #if ENABLE_HUSH_INTERACTIVE
1774 i->promptmode = 0; /* PS1 */
1784 #define B_CHUNK (32 * sizeof(char*))
1786 static void o_reset_to_empty_unquoted(o_string *o)
1794 static void o_free(o_string *o)
1797 memset(o, 0, sizeof(*o));
1800 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1805 static void o_grow_by(o_string *o, int len)
1807 if (o->length + len > o->maxlen) {
1808 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1809 o->data = xrealloc(o->data, 1 + o->maxlen);
1813 static void o_addchr(o_string *o, int ch)
1815 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1817 o->data[o->length] = ch;
1819 o->data[o->length] = '\0';
1822 static void o_addblock(o_string *o, const char *str, int len)
1825 memcpy(&o->data[o->length], str, len);
1827 o->data[o->length] = '\0';
1830 static void o_addstr(o_string *o, const char *str)
1832 o_addblock(o, str, strlen(str));
1836 static void nommu_addchr(o_string *o, int ch)
1842 # define nommu_addchr(o, str) ((void)0)
1845 static void o_addstr_with_NUL(o_string *o, const char *str)
1847 o_addblock(o, str, strlen(str) + 1);
1850 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1855 && (*str != '*' && *str != '?' && *str != '[')
1863 #undef HUSH_BRACE_EXP
1865 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1866 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1867 * Apparently, on unquoted $v bash still does globbing
1868 * ("v='*.txt'; echo $v" prints all .txt files),
1869 * but NOT brace expansion! Thus, there should be TWO independent
1870 * quoting mechanisms on $v expansion side: one protects
1871 * $v from brace expansion, and other additionally protects "$v" against globbing.
1872 * We have only second one.
1875 #ifdef HUSH_BRACE_EXP
1876 # define MAYBE_BRACES "{}"
1878 # define MAYBE_BRACES ""
1881 /* My analysis of quoting semantics tells me that state information
1882 * is associated with a destination, not a source.
1884 static void o_addqchr(o_string *o, int ch)
1887 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1892 o->data[o->length] = '\\';
1895 o->data[o->length] = ch;
1897 o->data[o->length] = '\0';
1900 static void o_addQchr(o_string *o, int ch)
1903 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1905 o->data[o->length] = '\\';
1909 o->data[o->length] = ch;
1911 o->data[o->length] = '\0';
1914 static void o_addQstr(o_string *o, const char *str, int len)
1917 o_addblock(o, str, len);
1923 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1924 if (ordinary_cnt > len) /* paranoia */
1926 o_addblock(o, str, ordinary_cnt);
1927 if (ordinary_cnt == len)
1929 str += ordinary_cnt;
1930 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1934 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1936 o->data[o->length] = '\\';
1940 o->data[o->length] = ch;
1942 o->data[o->length] = '\0';
1946 /* A special kind of o_string for $VAR and `cmd` expansion.
1947 * It contains char* list[] at the beginning, which is grown in 16 element
1948 * increments. Actual string data starts at the next multiple of 16 * (char*).
1949 * list[i] contains an INDEX (int!) into this string data.
1950 * It means that if list[] needs to grow, data needs to be moved higher up
1951 * but list[i]'s need not be modified.
1952 * NB: remembering how many list[i]'s you have there is crucial.
1953 * o_finalize_list() operation post-processes this structure - calculates
1954 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1956 #if DEBUG_EXPAND || DEBUG_GLOB
1957 static void debug_print_list(const char *prefix, o_string *o, int n)
1959 char **list = (char**)o->data;
1960 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1964 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1965 prefix, list, n, string_start, o->length, o->maxlen);
1968 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1969 o->data + (int)list[i] + string_start,
1970 o->data + (int)list[i] + string_start);
1974 const char *p = o->data + (int)list[n - 1] + string_start;
1976 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1980 # define debug_print_list(prefix, o, n) ((void)0)
1983 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1984 * in list[n] so that it points past last stored byte so far.
1985 * It returns n+1. */
1986 static int o_save_ptr_helper(o_string *o, int n)
1988 char **list = (char**)o->data;
1992 if (!o->has_empty_slot) {
1993 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1994 string_len = o->length - string_start;
1995 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1996 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1997 /* list[n] points to string_start, make space for 16 more pointers */
1998 o->maxlen += 0x10 * sizeof(list[0]);
1999 o->data = xrealloc(o->data, o->maxlen + 1);
2000 list = (char**)o->data;
2001 memmove(list + n + 0x10, list + n, string_len);
2002 o->length += 0x10 * sizeof(list[0]);
2004 debug_printf_list("list[%d]=%d string_start=%d\n",
2005 n, string_len, string_start);
2008 /* We have empty slot at list[n], reuse without growth */
2009 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2010 string_len = o->length - string_start;
2011 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2012 n, string_len, string_start);
2013 o->has_empty_slot = 0;
2015 list[n] = (char*)(ptrdiff_t)string_len;
2019 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2020 static int o_get_last_ptr(o_string *o, int n)
2022 char **list = (char**)o->data;
2023 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2025 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2028 #ifdef HUSH_BRACE_EXP
2029 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2030 * first, it processes even {a} (no commas), second,
2031 * I didn't manage to make it return strings when they don't match
2032 * existing files. Need to re-implement it.
2036 static int glob_needed(const char *s)
2045 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2051 /* Return pointer to next closing brace or to comma */
2052 static const char *next_brace_sub(const char *cp)
2056 while (*cp != '\0') {
2063 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2065 if (*cp++ == '{') /*}*/
2069 return *cp != '\0' ? cp : NULL;
2071 /* Recursive brace globber. Note: may garble pattern[]. */
2072 static int glob_brace(char *pattern, o_string *o, int n)
2074 char *new_pattern_buf;
2081 debug_printf_glob("glob_brace('%s')\n", pattern);
2087 if (*begin == '{') /*}*/ {
2088 /* Find the first sub-pattern and at the same time
2089 * find the rest after the closing brace */
2090 next = next_brace_sub(begin);
2092 /* An illegal expression */
2095 /*{*/ if (*next == '}') {
2096 /* "{abc}" with no commas - illegal
2097 * brace expr, disregard and skip it */
2103 if (*begin == '\\' && begin[1] != '\0')
2107 debug_printf_glob("begin:%s\n", begin);
2108 debug_printf_glob("next:%s\n", next);
2110 /* Now find the end of the whole brace expression */
2112 /*{*/ while (*rest != '}') {
2113 rest = next_brace_sub(rest);
2115 /* An illegal expression */
2118 debug_printf_glob("rest:%s\n", rest);
2120 rest_len = strlen(++rest) + 1;
2122 /* We are sure the brace expression is well-formed */
2124 /* Allocate working buffer large enough for our work */
2125 new_pattern_buf = xmalloc(strlen(pattern));
2127 /* We have a brace expression. BEGIN points to the opening {,
2128 * NEXT points past the terminator of the first element, and REST
2129 * points past the final }. We will accumulate result names from
2130 * recursive runs for each brace alternative in the buffer using
2135 /* Construct the new glob expression */
2138 mempcpy(new_pattern_buf,
2139 /* We know the prefix for all sub-patterns */
2140 pattern, begin - pattern),
2144 /* Note: glob_brace() may garble new_pattern_buf[].
2145 * That's why we re-copy prefix every time (1st memcpy above).
2147 n = glob_brace(new_pattern_buf, o, n);
2148 /*{*/ if (*next == '}') {
2149 /* We saw the last entry */
2153 next = next_brace_sub(next);
2155 free(new_pattern_buf);
2163 memset(&globdata, 0, sizeof(globdata));
2164 gr = glob(pattern, 0, NULL, &globdata);
2165 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2167 if (gr == GLOB_NOMATCH) {
2168 globfree(&globdata);
2169 /* NB: garbles parameter */
2170 unbackslash(pattern);
2171 o_addstr_with_NUL(o, pattern);
2172 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2173 return o_save_ptr_helper(o, n);
2175 if (gr == GLOB_NOSPACE)
2176 bb_error_msg_and_die(bb_msg_memory_exhausted);
2177 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2178 * but we didn't specify it. Paranoia again. */
2179 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2181 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2182 char **argv = globdata.gl_pathv;
2184 o_addstr_with_NUL(o, *argv);
2185 n = o_save_ptr_helper(o, n);
2191 globfree(&globdata);
2195 /* Performs globbing on last list[],
2196 * saving each result as a new list[].
2198 static int o_glob(o_string *o, int n)
2200 char *pattern, *copy;
2202 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2204 return o_save_ptr_helper(o, n);
2205 pattern = o->data + o_get_last_ptr(o, n);
2206 debug_printf_glob("glob pattern '%s'\n", pattern);
2207 if (!glob_needed(pattern)) {
2208 /* unbackslash last string in o in place, fix length */
2209 o->length = unbackslash(pattern) - o->data;
2210 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2211 return o_save_ptr_helper(o, n);
2214 copy = xstrdup(pattern);
2215 /* "forget" pattern in o */
2216 o->length = pattern - o->data;
2217 n = glob_brace(copy, o, n);
2220 debug_print_list("o_glob returning", o, n);
2227 static int glob_needed(const char *s)
2236 if (*s == '*' || *s == '[' || *s == '?')
2242 /* Performs globbing on last list[],
2243 * saving each result as a new list[].
2245 static int o_glob(o_string *o, int n)
2251 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2253 return o_save_ptr_helper(o, n);
2254 pattern = o->data + o_get_last_ptr(o, n);
2255 debug_printf_glob("glob pattern '%s'\n", pattern);
2256 if (!glob_needed(pattern)) {
2258 /* unbackslash last string in o in place, fix length */
2259 o->length = unbackslash(pattern) - o->data;
2260 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2261 return o_save_ptr_helper(o, n);
2264 memset(&globdata, 0, sizeof(globdata));
2265 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2266 * If we glob "*.\*" and don't find anything, we need
2267 * to fall back to using literal "*.*", but GLOB_NOCHECK
2268 * will return "*.\*"!
2270 gr = glob(pattern, 0, NULL, &globdata);
2271 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2273 if (gr == GLOB_NOMATCH) {
2274 globfree(&globdata);
2277 if (gr == GLOB_NOSPACE)
2278 bb_error_msg_and_die(bb_msg_memory_exhausted);
2279 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2280 * but we didn't specify it. Paranoia again. */
2281 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2283 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2284 char **argv = globdata.gl_pathv;
2285 /* "forget" pattern in o */
2286 o->length = pattern - o->data;
2288 o_addstr_with_NUL(o, *argv);
2289 n = o_save_ptr_helper(o, n);
2295 globfree(&globdata);
2297 debug_print_list("o_glob returning", o, n);
2303 /* If o->o_glob == 1, glob the string so far remembered.
2304 * Otherwise, just finish current list[] and start new */
2305 static int o_save_ptr(o_string *o, int n)
2307 if (o->o_glob) { /* if globbing is requested */
2308 /* If o->has_empty_slot, list[n] was already globbed
2309 * (if it was requested back then when it was filled)
2310 * so don't do that again! */
2311 if (!o->has_empty_slot)
2312 return o_glob(o, n); /* o_save_ptr_helper is inside */
2314 return o_save_ptr_helper(o, n);
2317 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2318 static char **o_finalize_list(o_string *o, int n)
2323 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2325 debug_print_list("finalized", o, n);
2326 debug_printf_expand("finalized n:%d\n", n);
2327 list = (char**)o->data;
2328 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2332 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2338 /* Expansion can recurse */
2339 #if ENABLE_HUSH_TICK
2340 static int process_command_subs(o_string *dest, const char *s);
2342 static char *expand_string_to_string(const char *str);
2344 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2345 parse_stream_dquoted(dest, input, dquote_end)
2347 static int parse_stream_dquoted(o_string *as_string,
2349 struct in_str *input,
2352 /* expand_strvec_to_strvec() takes a list of strings, expands
2353 * all variable references within and returns a pointer to
2354 * a list of expanded strings, possibly with larger number
2355 * of strings. (Think VAR="a b"; echo $VAR).
2356 * This new list is allocated as a single malloc block.
2357 * NULL-terminated list of char* pointers is at the beginning of it,
2358 * followed by strings themself.
2359 * Caller can deallocate entire list by single free(list). */
2361 /* Store given string, finalizing the word and starting new one whenever
2362 * we encounter IFS char(s). This is used for expanding variable values.
2363 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2364 static int expand_on_ifs(o_string *output, int n, const char *str)
2367 int word_len = strcspn(str, G.ifs);
2369 if (output->o_escape || !output->o_glob)
2370 o_addQstr(output, str, word_len);
2371 else /* protect backslashes against globbing up :) */
2372 o_addblock_duplicate_backslash(output, str, word_len);
2375 if (!*str) /* EOL - do not finalize word */
2377 o_addchr(output, '\0');
2378 debug_print_list("expand_on_ifs", output, n);
2379 n = o_save_ptr(output, n);
2380 str += strspn(str, G.ifs); /* skip ifs chars */
2382 debug_print_list("expand_on_ifs[1]", output, n);
2386 /* Helper to expand $((...)) and heredoc body. These act as if
2387 * they are in double quotes, with the exception that they are not :).
2388 * Just the rules are similar: "expand only $var and `cmd`"
2390 * Returns malloced string.
2391 * As an optimization, we return NULL if expansion is not needed.
2393 static char *expand_pseudo_dquoted(const char *str)
2396 struct in_str input;
2397 o_string dest = NULL_O_STRING;
2399 if (strchr(str, '$') == NULL
2400 #if ENABLE_HUSH_TICK
2401 && strchr(str, '`') == NULL
2407 /* We need to expand. Example:
2408 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2410 setup_string_in_str(&input, str);
2411 parse_stream_dquoted(NULL, &dest, &input, EOF);
2412 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2413 exp_str = expand_string_to_string(dest.data);
2414 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2415 o_free_unsafe(&dest);
2419 #if ENABLE_SH_MATH_SUPPORT
2420 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
2422 arith_eval_hooks_t hooks;
2426 hooks.lookupvar = get_local_var_value;
2427 hooks.setvar = set_local_var_from_halves;
2428 hooks.endofname = endofname;
2429 exp_str = expand_pseudo_dquoted(arg);
2430 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
2436 /* Expand all variable references in given string, adding words to list[]
2437 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2438 * to be filled). This routine is extremely tricky: has to deal with
2439 * variables/parameters with whitespace, $* and $@, and constructs like
2440 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2441 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2443 /* or_mask is either 0 (normal case) or 0x80 -
2444 * expansion of right-hand side of assignment == 1-element expand.
2445 * It will also do no globbing, and thus we must not backslash-quote!
2452 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2453 debug_print_list("expand_vars_to_list", output, n);
2454 n = o_save_ptr(output, n);
2455 debug_print_list("expand_vars_to_list[0]", output, n);
2457 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2460 char *to_be_freed = NULL;
2461 const char *val = NULL;
2462 #if ENABLE_HUSH_TICK
2463 o_string subst_result = NULL_O_STRING;
2465 #if ENABLE_SH_MATH_SUPPORT
2466 char arith_buf[sizeof(arith_t)*3 + 2];
2468 o_addblock(output, arg, p - arg);
2469 debug_print_list("expand_vars_to_list[1]", output, n);
2471 p = strchr(p, SPECIAL_VAR_SYMBOL);
2473 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2474 /* "$@" is special. Even if quoted, it can still
2475 * expand to nothing (not even an empty string) */
2476 if ((first_ch & 0x7f) != '@')
2477 ored_ch |= first_ch;
2479 switch (first_ch & 0x7f) {
2480 /* Highest bit in first_ch indicates that var is double-quoted */
2484 if (!G.global_argv[i])
2486 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2487 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2488 smallint sv = output->o_escape;
2489 /* unquoted var's contents should be globbed, so don't escape */
2490 output->o_escape = 0;
2491 while (G.global_argv[i]) {
2492 n = expand_on_ifs(output, n, G.global_argv[i]);
2493 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2494 if (G.global_argv[i++][0] && G.global_argv[i]) {
2495 /* this argv[] is not empty and not last:
2496 * put terminating NUL, start new word */
2497 o_addchr(output, '\0');
2498 debug_print_list("expand_vars_to_list[2]", output, n);
2499 n = o_save_ptr(output, n);
2500 debug_print_list("expand_vars_to_list[3]", output, n);
2503 output->o_escape = sv;
2505 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2506 * and in this case should treat it like '$*' - see 'else...' below */
2507 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2509 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2510 if (++i >= G.global_argc)
2512 o_addchr(output, '\0');
2513 debug_print_list("expand_vars_to_list[4]", output, n);
2514 n = o_save_ptr(output, n);
2516 } else { /* quoted $*: add as one word */
2518 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2519 if (!G.global_argv[++i])
2522 o_addchr(output, G.ifs[0]);
2526 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2527 /* "Empty variable", used to make "" etc to not disappear */
2531 #if ENABLE_HUSH_TICK
2532 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2535 /* Can't just stuff it into output o_string,
2536 * expanded result may need to be globbed
2537 * and $IFS-splitted */
2538 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2539 G.last_exitcode = process_command_subs(&subst_result, arg);
2540 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2541 val = subst_result.data;
2544 #if ENABLE_SH_MATH_SUPPORT
2545 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2549 arg++; /* skip '+' */
2550 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2551 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2552 res = expand_and_evaluate_arith(arg, &errcode);
2555 const char *msg = "error in arithmetic";
2558 msg = "exponent less than 0";
2561 msg = "divide by 0";
2564 msg = "expression recursion loop detected";
2569 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2570 sprintf(arith_buf, arith_t_fmt, res);
2575 default: { /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2579 char exp_save = exp_save; /* for compiler */
2580 char *exp_saveptr; /* points to expansion operator */
2581 char *exp_word = exp_word; /* for compiler */
2585 exp_saveptr = arg[1] ? strchr("%#:-=+?", arg[1]) : NULL;
2586 first_char = arg[0] = first_ch & 0x7f;
2589 if (first_char == '#' && arg[1] && !exp_saveptr) {
2590 /* handle length expansion ${#var} */
2594 /* maybe handle parameter expansion */
2595 if (exp_saveptr /* if 2nd char is one of expansion operators */
2596 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
2598 /* ${?:0}, ${#[:]%0} etc */
2599 exp_saveptr = var + 1;
2601 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
2602 exp_saveptr = var+1 + strcspn(var+1, "%#:-=+?");
2604 exp_op = exp_save = *exp_saveptr;
2606 exp_word = exp_saveptr + 1;
2607 if (exp_op == ':') {
2608 exp_op = *exp_word++;
2609 if (ENABLE_HUSH_BASH_COMPAT
2610 && (exp_op == '\0' || !strchr("%#:-=+?"+3, exp_op))
2612 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
2617 *exp_saveptr = '\0';
2618 } /* else: it's not an expansion op, but bare ${var} */
2621 /* lookup the variable in question */
2622 if (isdigit(var[0])) {
2623 /* parse_dollar() should have vetted var for us */
2625 if (i < G.global_argc)
2626 val = G.global_argv[i];
2627 /* else val remains NULL: $N with too big N */
2631 val = utoa(G.root_pid);
2633 case '!': /* bg pid */
2634 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2636 case '?': /* exitcode */
2637 val = utoa(G.last_exitcode);
2639 case '#': /* argc */
2640 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2643 val = get_local_var_value(var);
2647 /* handle any expansions */
2648 if (exp_op == 'L') {
2649 debug_printf_expand("expand: length(%s)=", val);
2650 val = utoa(val ? strlen(val) : 0);
2651 debug_printf_expand("%s\n", val);
2652 } else if (exp_op) {
2653 if (exp_op == '%' || exp_op == '#') {
2654 /* Standard-mandated substring removal ops:
2655 * ${parameter%word} - remove smallest suffix pattern
2656 * ${parameter%%word} - remove largest suffix pattern
2657 * ${parameter#word} - remove smallest prefix pattern
2658 * ${parameter##word} - remove largest prefix pattern
2660 * Word is expanded to produce a glob pattern.
2661 * Then var's value is matched to it and matching part removed.
2666 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2667 if (exp_op == *exp_word) /* ## or %% */
2669 val = to_be_freed = xstrdup(val);
2671 char *exp_exp_word = expand_pseudo_dquoted(exp_word);
2673 exp_word = exp_exp_word;
2674 loc = scan(to_be_freed, exp_word, match_at_left);
2675 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
2676 // exp_op, to_be_freed, exp_word, loc);
2679 if (loc) { /* match was found */
2680 if (match_at_left) /* # or ## */
2686 } else if (exp_op == ':') {
2687 #if ENABLE_HUSH_BASH_COMPAT
2688 /* It's ${var:N[:M]} bashism.
2689 * Note that in encoded form it has TWO parts:
2690 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
2695 beg = expand_and_evaluate_arith(exp_word, &errcode);
2696 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
2697 *p++ = SPECIAL_VAR_SYMBOL;
2699 p = strchr(p, SPECIAL_VAR_SYMBOL);
2701 len = expand_and_evaluate_arith(exp_word, &errcode);
2702 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
2704 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
2705 if (beg < 0) /* bash compat */
2707 debug_printf_varexp("from val:'%s'\n", val);
2708 if (len == 0 || !val || beg >= strlen(val))
2711 /* Paranoia. What if user entered 9999999999999
2712 * which fits in arith_t but not int? */
2715 val = to_be_freed = xstrndup(val + beg, len);
2717 debug_printf_varexp("val:'%s'\n", val);
2721 die_if_script("malformed ${%s:...}", var);
2724 } else { /* one of "-=+?" */
2725 /* Standard-mandated substitution ops:
2726 * ${var?word} - indicate error if unset
2727 * If var is unset, word (or a message indicating it is unset
2728 * if word is null) is written to standard error
2729 * and the shell exits with a non-zero exit status.
2730 * Otherwise, the value of var is substituted.
2731 * ${var-word} - use default value
2732 * If var is unset, word is substituted.
2733 * ${var=word} - assign and use default value
2734 * If var is unset, word is assigned to var.
2735 * In all cases, final value of var is substituted.
2736 * ${var+word} - use alternative value
2737 * If var is unset, null is substituted.
2738 * Otherwise, word is substituted.
2740 * Word is subjected to tilde expansion, parameter expansion,
2741 * command substitution, and arithmetic expansion.
2742 * If word is not needed, it is not expanded.
2744 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2745 * but also treat null var as if it is unset.
2747 int use_word = (!val || ((exp_save == ':') && !val[0]));
2749 use_word = !use_word;
2750 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2751 (exp_save == ':') ? "true" : "false", use_word);
2753 to_be_freed = expand_pseudo_dquoted(exp_word);
2755 exp_word = to_be_freed;
2756 if (exp_op == '?') {
2757 /* mimic bash message */
2758 die_if_script("%s: %s",
2760 exp_word[0] ? exp_word : "parameter null or not set"
2762 //TODO: how interactive bash aborts expansion mid-command?
2767 if (exp_op == '=') {
2768 /* ${var=[word]} or ${var:=[word]} */
2769 if (isdigit(var[0]) || var[0] == '#') {
2770 /* mimic bash message */
2771 die_if_script("$%s: cannot assign in this way", var);
2774 char *new_var = xasprintf("%s=%s", var, val);
2775 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2779 } /* one of "-=+?" */
2781 *exp_saveptr = exp_save;
2785 #if ENABLE_HUSH_TICK
2788 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2789 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2791 /* unquoted var's contents should be globbed, so don't escape */
2792 smallint sv = output->o_escape;
2793 output->o_escape = 0;
2794 n = expand_on_ifs(output, n, val);
2796 output->o_escape = sv;
2798 } else { /* quoted $VAR, val will be appended below */
2799 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2802 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2805 o_addQstr(output, val, strlen(val));
2808 /* Do the check to avoid writing to a const string */
2809 if (*p != SPECIAL_VAR_SYMBOL)
2810 *p = SPECIAL_VAR_SYMBOL;
2812 #if ENABLE_HUSH_TICK
2813 o_free(&subst_result);
2816 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2819 debug_print_list("expand_vars_to_list[a]", output, n);
2820 /* this part is literal, and it was already pre-quoted
2821 * if needed (much earlier), do not use o_addQstr here! */
2822 o_addstr_with_NUL(output, arg);
2823 debug_print_list("expand_vars_to_list[b]", output, n);
2824 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2825 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2828 /* allow to reuse list[n] later without re-growth */
2829 output->has_empty_slot = 1;
2831 o_addchr(output, '\0');
2836 static char **expand_variables(char **argv, int or_mask)
2841 o_string output = NULL_O_STRING;
2843 if (or_mask & 0x100) {
2844 output.o_escape = 1; /* protect against globbing for "$var" */
2845 /* (unquoted $var will temporarily switch it off) */
2852 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2855 debug_print_list("expand_variables", &output, n);
2857 /* output.data (malloced in one block) gets returned in "list" */
2858 list = o_finalize_list(&output, n);
2859 debug_print_strings("expand_variables[1]", list);
2863 static char **expand_strvec_to_strvec(char **argv)
2865 return expand_variables(argv, 0x100);
2868 #if ENABLE_HUSH_BASH_COMPAT
2869 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2871 return expand_variables(argv, 0x80);
2875 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2876 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2881 o_string output = NULL_O_STRING;
2886 int is_var = is_well_formed_var_name(*v, '=');
2887 /* is_var * 0x80: singleword expansion for vars */
2888 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2890 /* Subtle! expand_vars_to_list did not glob last word yet.
2891 * It does this only when fed with further data.
2892 * Therefore we set globbing flags AFTER it, not before:
2895 /* if it is not recognizably abc=...; then: */
2896 output.o_escape = !is_var; /* protect against globbing for "$var" */
2897 /* (unquoted $var will temporarily switch it off) */
2898 output.o_glob = !is_var; /* and indeed do globbing */
2901 debug_print_list("expand_cond", &output, n);
2903 /* output.data (malloced in one block) gets returned in "list" */
2904 list = o_finalize_list(&output, n);
2905 debug_print_strings("expand_cond[1]", list);
2910 /* Used for expansion of right hand of assignments */
2911 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2913 static char *expand_string_to_string(const char *str)
2915 char *argv[2], **list;
2917 argv[0] = (char*)str;
2919 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2921 if (!list[0] || list[1])
2922 bb_error_msg_and_die("BUG in varexp2");
2923 /* actually, just move string 2*sizeof(char*) bytes back */
2924 overlapping_strcpy((char*)list, list[0]);
2925 unbackslash((char*)list);
2926 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2930 /* Used for "eval" builtin */
2931 static char* expand_strvec_to_string(char **argv)
2935 list = expand_variables(argv, 0x80);
2936 /* Convert all NULs to spaces */
2941 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2942 bb_error_msg_and_die("BUG in varexp3");
2943 /* bash uses ' ' regardless of $IFS contents */
2948 overlapping_strcpy((char*)list, list[0]);
2949 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2953 static char **expand_assignments(char **argv, int count)
2957 /* Expand assignments into one string each */
2958 for (i = 0; i < count; i++) {
2959 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2967 void re_execute_shell(char ***to_free, const char *s,
2968 char *g_argv0, char **g_argv,
2969 char **builtin_argv) NORETURN;
2971 static void reset_traps_to_defaults(void)
2973 /* This function is always called in a child shell
2974 * after fork (not vfork, NOMMU doesn't use this function).
2979 /* Child shells are not interactive.
2980 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2981 * Testcase: (while :; do :; done) + ^Z should background.
2982 * Same goes for SIGTERM, SIGHUP, SIGINT.
2984 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2985 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2987 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2988 * Stupid. It can be done with *single* &= op, but we can't use
2989 * the fact that G.blocked_set is implemented as a bitmask
2991 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2995 /* Careful. Only if no trap or trap is not "" */
2996 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2997 sigdelset(&G.blocked_set, sig);
3004 /* Our homegrown sig mask is saner to work with :) */
3005 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
3007 /* Resetting all traps to default except empty ones */
3008 mask = G.non_DFL_mask;
3009 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
3010 if (!G.traps[sig] || !G.traps[sig][0])
3013 G.traps[sig] = NULL;
3014 /* There is no signal for 0 (EXIT) */
3017 /* There was a trap handler, we just removed it.
3018 * But if sig still has non-DFL handling,
3019 * we should not unblock the sig. */
3022 sigdelset(&G.blocked_set, sig);
3024 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
3029 static void re_execute_shell(char ***to_free, const char *s,
3030 char *g_argv0, char **g_argv,
3031 char **builtin_argv) NORETURN;
3032 static void re_execute_shell(char ***to_free, const char *s,
3033 char *g_argv0, char **g_argv,
3034 char **builtin_argv)
3036 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
3037 /* delims + 2 * (number of bytes in printed hex numbers) */
3038 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
3039 char *heredoc_argv[4];
3040 struct variable *cur;
3041 # if ENABLE_HUSH_FUNCTIONS
3042 struct function *funcp;
3046 unsigned long long empty_trap_mask;
3048 if (!g_argv0) { /* heredoc */
3049 argv = heredoc_argv;
3050 argv[0] = (char *) G.argv0_for_re_execing;
3051 argv[1] = (char *) "-<";
3052 argv[2] = (char *) s;
3054 pp = &argv[3]; /* used as pointer to empty environment */
3060 if (pp) while (*pp++)
3063 empty_trap_mask = 0;
3066 for (sig = 1; sig < NSIG; sig++) {
3067 if (G.traps[sig] && !G.traps[sig][0])
3068 empty_trap_mask |= 1LL << sig;
3072 sprintf(param_buf, NOMMU_HACK_FMT
3073 , (unsigned) G.root_pid
3074 , (unsigned) G.root_ppid
3075 , (unsigned) G.last_bg_pid
3076 , (unsigned) G.last_exitcode
3079 IF_HUSH_LOOPS(, G.depth_of_loop)
3081 #undef NOMMU_HACK_FMT
3082 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3083 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3086 for (cur = G.top_var; cur; cur = cur->next) {
3087 if (!cur->flg_export || cur->flg_read_only)
3090 # if ENABLE_HUSH_FUNCTIONS
3091 for (funcp = G.top_func; funcp; funcp = funcp->next)
3097 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3098 *pp++ = (char *) G.argv0_for_re_execing;
3100 for (cur = G.top_var; cur; cur = cur->next) {
3101 if (cur->varstr == hush_version_str)
3103 if (cur->flg_read_only) {
3104 *pp++ = (char *) "-R";
3105 *pp++ = cur->varstr;
3106 } else if (!cur->flg_export) {
3107 *pp++ = (char *) "-V";
3108 *pp++ = cur->varstr;
3111 # if ENABLE_HUSH_FUNCTIONS
3112 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3113 *pp++ = (char *) "-F";
3114 *pp++ = funcp->name;
3115 *pp++ = funcp->body_as_string;
3118 /* We can pass activated traps here. Say, -Tnn:trap_string
3120 * However, POSIX says that subshells reset signals with traps
3122 * I tested bash-3.2 and it not only does that with true subshells
3123 * of the form ( list ), but with any forked children shells.
3124 * I set trap "echo W" WINCH; and then tried:
3126 * { echo 1; sleep 20; echo 2; } &
3127 * while true; do echo 1; sleep 20; echo 2; break; done &
3128 * true | { echo 1; sleep 20; echo 2; } | cat
3130 * In all these cases sending SIGWINCH to the child shell
3131 * did not run the trap. If I add trap "echo V" WINCH;
3132 * _inside_ group (just before echo 1), it works.
3134 * I conclude it means we don't need to pass active traps here.
3135 * Even if we would use signal handlers instead of signal masking
3136 * in order to implement trap handling,
3137 * exec syscall below resets signals to SIG_DFL for us.
3139 *pp++ = (char *) "-c";
3142 while (*++builtin_argv)
3143 *pp++ = *builtin_argv;
3144 *pp++ = (char *) "";
3149 /* *pp = NULL; - is already there */
3153 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3154 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3155 execve(bb_busybox_exec_path, argv, pp);
3156 /* Fallback. Useful for init=/bin/hush usage etc */
3157 if (argv[0][0] == '/')
3158 execve(argv[0], argv, pp);
3159 xfunc_error_retval = 127;
3160 bb_error_msg_and_die("can't re-execute the shell");
3162 #endif /* !BB_MMU */
3165 static void setup_heredoc(struct redir_struct *redir)
3167 struct fd_pair pair;
3170 /* the _body_ of heredoc (misleading field name) */
3171 const char *heredoc = redir->rd_filename;
3178 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3179 expanded = expand_pseudo_dquoted(heredoc);
3183 len = strlen(heredoc);
3185 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3187 xmove_fd(pair.rd, redir->rd_fd);
3189 /* Try writing without forking. Newer kernels have
3190 * dynamically growing pipes. Must use non-blocking write! */
3193 written = write(pair.wr, heredoc, len);
3204 ndelay_off(pair.wr);
3206 /* Okay, pipe buffer was not big enough */
3207 /* Note: we must not create a stray child (bastard? :)
3208 * for the unsuspecting parent process. Child creates a grandchild
3209 * and exits before parent execs the process which consumes heredoc
3210 * (that exec happens after we return from this function) */
3216 bb_perror_msg_and_die("vfork");
3219 disable_restore_tty_pgrp_on_exit();
3220 pid = BB_MMU ? fork() : vfork();
3222 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3226 close(redir->rd_fd); /* read side of the pipe */
3228 full_write(pair.wr, heredoc, len); /* may loop or block */
3231 /* Delegate blocking writes to another process */
3232 xmove_fd(pair.wr, STDOUT_FILENO);
3233 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3237 #if ENABLE_HUSH_FAST
3239 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3241 enable_restore_tty_pgrp_on_exit();
3247 wait(NULL); /* wait till child has died */
3250 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3251 * and stderr if they are redirected. */
3252 static int setup_redirects(struct command *prog, int squirrel[])
3255 struct redir_struct *redir;
3257 for (redir = prog->redirects; redir; redir = redir->next) {
3258 if (redir->rd_type == REDIRECT_HEREDOC2) {
3259 /* rd_fd<<HERE case */
3260 if (squirrel && redir->rd_fd < 3
3261 && squirrel[redir->rd_fd] < 0
3263 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3265 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3267 debug_printf_parse("set heredoc '%s'\n",
3268 redir->rd_filename);
3269 setup_heredoc(redir);
3273 if (redir->rd_dup == REDIRFD_TO_FILE) {
3274 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3276 if (redir->rd_filename == NULL) {
3277 /* Something went wrong in the parse.
3278 * Pretend it didn't happen */
3279 bb_error_msg("bug in redirect parse");
3282 mode = redir_table[redir->rd_type].mode;
3283 p = expand_string_to_string(redir->rd_filename);
3284 openfd = open_or_warn(p, mode);
3287 /* this could get lost if stderr has been redirected, but
3288 * bash and ash both lose it as well (though zsh doesn't!) */
3289 //what the above comment tries to say?
3293 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3294 openfd = redir->rd_dup;
3297 if (openfd != redir->rd_fd) {
3298 if (squirrel && redir->rd_fd < 3
3299 && squirrel[redir->rd_fd] < 0
3301 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3303 if (openfd == REDIRFD_CLOSE) {
3304 /* "n>-" means "close me" */
3305 close(redir->rd_fd);
3307 xdup2(openfd, redir->rd_fd);
3308 if (redir->rd_dup == REDIRFD_TO_FILE)
3316 static void restore_redirects(int squirrel[])
3319 for (i = 0; i < 3; i++) {
3322 /* We simply die on error */
3329 static void free_pipe_list(struct pipe *head);
3331 /* Return code is the exit status of the pipe */
3332 static void free_pipe(struct pipe *pi)
3335 struct command *command;
3336 struct redir_struct *r, *rnext;
3339 if (pi->stopped_cmds > 0) /* why? */
3341 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3342 for (i = 0; i < pi->num_cmds; i++) {
3343 command = &pi->cmds[i];
3344 debug_printf_clean(" command %d:\n", i);
3345 if (command->argv) {
3346 for (a = 0, p = command->argv; *p; a++, p++) {
3347 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3349 free_strings(command->argv);
3350 command->argv = NULL;
3352 /* not "else if": on syntax error, we may have both! */
3353 if (command->group) {
3354 debug_printf_clean(" begin group (cmd_type:%d)\n",
3356 free_pipe_list(command->group);
3357 debug_printf_clean(" end group\n");
3358 command->group = NULL;
3360 /* else is crucial here.
3361 * If group != NULL, child_func is meaningless */
3362 #if ENABLE_HUSH_FUNCTIONS
3363 else if (command->child_func) {
3364 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3365 command->child_func->parent_cmd = NULL;
3369 free(command->group_as_string);
3370 command->group_as_string = NULL;
3372 for (r = command->redirects; r; r = rnext) {
3373 debug_printf_clean(" redirect %d%s",
3374 r->rd_fd, redir_table[r->rd_type].descrip);
3375 /* guard against the case >$FOO, where foo is unset or blank */
3376 if (r->rd_filename) {
3377 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3378 free(r->rd_filename);
3379 r->rd_filename = NULL;
3381 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3385 command->redirects = NULL;
3387 free(pi->cmds); /* children are an array, they get freed all at once */
3395 static void free_pipe_list(struct pipe *head)
3397 struct pipe *pi, *next;
3399 for (pi = head; pi; pi = next) {
3401 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3404 debug_printf_clean("pipe followup code %d\n", pi->followup);
3406 /*pi->next = NULL;*/
3412 static int run_list(struct pipe *pi);
3414 #define parse_stream(pstring, input, end_trigger) \
3415 parse_stream(input, end_trigger)
3417 static struct pipe *parse_stream(char **pstring,
3418 struct in_str *input,
3420 static void parse_and_run_string(const char *s);
3423 static char *find_in_path(const char *arg)
3426 const char *PATH = get_local_var_value("PATH");
3432 const char *end = strchrnul(PATH, ':');
3433 int sz = end - PATH; /* must be int! */
3437 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3439 /* We have xxx::yyyy in $PATH,
3440 * it means "use current dir" */
3443 if (access(ret, F_OK) == 0)
3456 static const struct built_in_command* find_builtin_helper(const char *name,
3457 const struct built_in_command *x,
3458 const struct built_in_command *end)
3461 if (strcmp(name, x->b_cmd) != 0) {
3465 debug_printf_exec("found builtin '%s'\n", name);
3470 static const struct built_in_command* find_builtin1(const char *name)
3472 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3474 static const struct built_in_command* find_builtin(const char *name)
3476 const struct built_in_command *x = find_builtin1(name);
3479 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3482 #if ENABLE_HUSH_FUNCTIONS
3483 static struct function **find_function_slot(const char *name)
3485 struct function **funcpp = &G.top_func;
3487 if (strcmp(name, (*funcpp)->name) == 0) {
3490 funcpp = &(*funcpp)->next;
3495 static const struct function *find_function(const char *name)
3497 const struct function *funcp = *find_function_slot(name);
3499 debug_printf_exec("found function '%s'\n", name);
3503 /* Note: takes ownership on name ptr */
3504 static struct function *new_function(char *name)
3506 struct function **funcpp = find_function_slot(name);
3507 struct function *funcp = *funcpp;
3509 if (funcp != NULL) {
3510 struct command *cmd = funcp->parent_cmd;
3511 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3513 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3515 /* Note: if !funcp->body, do not free body_as_string!
3516 * This is a special case of "-F name body" function:
3517 * body_as_string was not malloced! */
3519 free_pipe_list(funcp->body);
3521 free(funcp->body_as_string);
3525 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3526 cmd->argv[0] = funcp->name;
3527 cmd->group = funcp->body;
3529 cmd->group_as_string = funcp->body_as_string;
3533 debug_printf_exec("remembering new function '%s'\n", name);
3534 funcp = *funcpp = xzalloc(sizeof(*funcp));
3535 /*funcp->next = NULL;*/
3542 static void unset_func(const char *name)
3544 struct function **funcpp = find_function_slot(name);
3545 struct function *funcp = *funcpp;
3547 if (funcp != NULL) {
3548 debug_printf_exec("freeing function '%s'\n", funcp->name);
3549 *funcpp = funcp->next;
3550 /* funcp is unlinked now, deleting it.
3551 * Note: if !funcp->body, the function was created by
3552 * "-F name body", do not free ->body_as_string
3553 * and ->name as they were not malloced. */
3555 free_pipe_list(funcp->body);
3558 free(funcp->body_as_string);
3566 #define exec_function(to_free, funcp, argv) \
3567 exec_function(funcp, argv)
3569 static void exec_function(char ***to_free,
3570 const struct function *funcp,
3571 char **argv) NORETURN;
3572 static void exec_function(char ***to_free,
3573 const struct function *funcp,
3579 argv[0] = G.global_argv[0];
3580 G.global_argv = argv;
3584 /* On MMU, funcp->body is always non-NULL */
3585 n = run_list(funcp->body);
3589 re_execute_shell(to_free,
3590 funcp->body_as_string,
3597 static int run_function(const struct function *funcp, char **argv)
3603 save_and_replace_G_args(&sv, argv);
3605 /* "we are in function, ok to use return" */
3606 sv_flg = G.flag_return_in_progress;
3607 G.flag_return_in_progress = -1;
3608 # if ENABLE_HUSH_LOCAL
3609 G.func_nest_level++;
3612 /* On MMU, funcp->body is always non-NULL */
3615 /* Function defined by -F */
3616 parse_and_run_string(funcp->body_as_string);
3617 rc = G.last_exitcode;
3621 rc = run_list(funcp->body);
3624 # if ENABLE_HUSH_LOCAL
3626 struct variable *var;
3627 struct variable **var_pp;
3629 var_pp = &G.top_var;
3630 while ((var = *var_pp) != NULL) {
3631 if (var->func_nest_level < G.func_nest_level) {
3632 var_pp = &var->next;
3636 if (var->flg_export)
3637 bb_unsetenv(var->varstr);
3638 /* Remove from global list */
3639 *var_pp = var->next;
3645 G.func_nest_level--;
3648 G.flag_return_in_progress = sv_flg;
3650 restore_G_args(&sv, argv);
3654 #endif /* ENABLE_HUSH_FUNCTIONS */
3658 #define exec_builtin(to_free, x, argv) \
3659 exec_builtin(x, argv)
3661 #define exec_builtin(to_free, x, argv) \
3662 exec_builtin(to_free, argv)
3664 static void exec_builtin(char ***to_free,
3665 const struct built_in_command *x,
3666 char **argv) NORETURN;
3667 static void exec_builtin(char ***to_free,
3668 const struct built_in_command *x,
3672 int rcode = x->b_function(argv);
3676 /* On NOMMU, we must never block!
3677 * Example: { sleep 99 | read line; } & echo Ok
3679 re_execute_shell(to_free,
3688 static void execvp_or_die(char **argv) NORETURN;
3689 static void execvp_or_die(char **argv)
3691 debug_printf_exec("execing '%s'\n", argv[0]);
3692 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3693 execvp(argv[0], argv);
3694 bb_perror_msg("can't execute '%s'", argv[0]);
3695 _exit(127); /* bash compat */
3699 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3700 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3701 #define pseudo_exec(nommu_save, command, argv_expanded) \
3702 pseudo_exec(command, argv_expanded)
3705 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3707 * Don't exit() here. If you don't exec, use _exit instead.
3708 * The at_exit handlers apparently confuse the calling process,
3709 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3710 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3711 char **argv, int assignment_cnt,
3712 char **argv_expanded) NORETURN;
3713 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3714 char **argv, int assignment_cnt,
3715 char **argv_expanded)
3719 /* Case when we are here: ... | var=val | ... */
3720 if (!argv[assignment_cnt])
3721 _exit(EXIT_SUCCESS);
3723 new_env = expand_assignments(argv, assignment_cnt);
3725 set_vars_and_save_old(new_env);
3726 free(new_env); /* optional */
3727 /* we can also destroy set_vars_and_save_old's return value,
3730 nommu_save->new_env = new_env;
3731 nommu_save->old_vars = set_vars_and_save_old(new_env);
3733 if (argv_expanded) {
3734 argv = argv_expanded;
3736 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3738 nommu_save->argv = argv;
3742 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3743 if (strchr(argv[0], '/') != NULL)
3747 /* Check if the command matches any of the builtins.
3748 * Depending on context, this might be redundant. But it's
3749 * easier to waste a few CPU cycles than it is to figure out
3750 * if this is one of those cases.
3753 /* On NOMMU, it is more expensive to re-execute shell
3754 * just in order to run echo or test builtin.
3755 * It's better to skip it here and run corresponding
3756 * non-builtin later. */
3757 const struct built_in_command *x;
3758 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3760 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3763 #if ENABLE_HUSH_FUNCTIONS
3764 /* Check if the command matches any functions */
3766 const struct function *funcp = find_function(argv[0]);
3768 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3773 #if ENABLE_FEATURE_SH_STANDALONE
3774 /* Check if the command matches any busybox applets */
3776 int a = find_applet_by_name(argv[0]);
3778 # if BB_MMU /* see above why on NOMMU it is not allowed */
3779 if (APPLET_IS_NOEXEC(a)) {
3780 debug_printf_exec("running applet '%s'\n", argv[0]);
3781 run_applet_no_and_exit(a, argv);
3784 /* Re-exec ourselves */
3785 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3786 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3787 execv(bb_busybox_exec_path, argv);
3788 /* If they called chroot or otherwise made the binary no longer
3789 * executable, fall through */
3794 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3797 execvp_or_die(argv);
3800 /* Called after [v]fork() in run_pipe
3802 static void pseudo_exec(nommu_save_t *nommu_save,
3803 struct command *command,
3804 char **argv_expanded) NORETURN;
3805 static void pseudo_exec(nommu_save_t *nommu_save,
3806 struct command *command,
3807 char **argv_expanded)
3809 if (command->argv) {
3810 pseudo_exec_argv(nommu_save, command->argv,
3811 command->assignment_cnt, argv_expanded);
3814 if (command->group) {
3815 /* Cases when we are here:
3818 * ... | ( list ) | ...
3819 * ... | { list } | ...
3823 debug_printf_exec("pseudo_exec: run_list\n");
3824 reset_traps_to_defaults();
3825 rcode = run_list(command->group);
3826 /* OK to leak memory by not calling free_pipe_list,
3827 * since this process is about to exit */
3830 re_execute_shell(&nommu_save->argv_from_re_execing,
3831 command->group_as_string,
3838 /* Case when we are here: ... | >file */
3839 debug_printf_exec("pseudo_exec'ed null command\n");
3840 _exit(EXIT_SUCCESS);
3844 static const char *get_cmdtext(struct pipe *pi)
3850 /* This is subtle. ->cmdtext is created only on first backgrounding.
3851 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3852 * On subsequent bg argv is trashed, but we won't use it */
3855 argv = pi->cmds[0].argv;
3856 if (!argv || !argv[0]) {
3857 pi->cmdtext = xzalloc(1);
3863 len += strlen(*argv) + 1;
3867 argv = pi->cmds[0].argv;
3869 len = strlen(*argv);
3870 memcpy(p, *argv, len);
3878 static void insert_bg_job(struct pipe *pi)
3880 struct pipe *job, **jobp;
3883 /* Linear search for the ID of the job to use */
3885 for (job = G.job_list; job; job = job->next)
3886 if (job->jobid >= pi->jobid)
3887 pi->jobid = job->jobid + 1;
3889 /* Add job to the list of running jobs */
3891 while ((job = *jobp) != NULL)
3893 job = *jobp = xmalloc(sizeof(*job));
3895 *job = *pi; /* physical copy */
3897 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3898 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3899 for (i = 0; i < pi->num_cmds; i++) {
3900 job->cmds[i].pid = pi->cmds[i].pid;
3901 /* all other fields are not used and stay zero */
3903 job->cmdtext = xstrdup(get_cmdtext(pi));
3905 if (G_interactive_fd)
3906 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3907 /* Last command's pid goes to $! */
3908 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3909 G.last_jobid = job->jobid;
3912 static void remove_bg_job(struct pipe *pi)
3914 struct pipe *prev_pipe;
3916 if (pi == G.job_list) {
3917 G.job_list = pi->next;
3919 prev_pipe = G.job_list;
3920 while (prev_pipe->next != pi)
3921 prev_pipe = prev_pipe->next;
3922 prev_pipe->next = pi->next;
3925 G.last_jobid = G.job_list->jobid;
3930 /* Remove a backgrounded job */
3931 static void delete_finished_bg_job(struct pipe *pi)
3934 pi->stopped_cmds = 0;
3940 /* Check to see if any processes have exited -- if they
3941 * have, figure out why and see if a job has completed */
3942 static int checkjobs(struct pipe* fg_pipe)
3952 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3954 attributes = WUNTRACED;
3955 if (fg_pipe == NULL)
3956 attributes |= WNOHANG;
3959 #if ENABLE_HUSH_FAST
3960 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3961 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3962 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3963 /* There was neither fork nor SIGCHLD since last waitpid */
3964 /* Avoid doing waitpid syscall if possible */
3965 if (!G.we_have_children) {
3969 if (fg_pipe == NULL) { /* is WNOHANG set? */
3970 /* We have children, but they did not exit
3971 * or stop yet (we saw no SIGCHLD) */
3974 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3978 /* Do we do this right?
3979 * bash-3.00# sleep 20 | false
3981 * [3]+ Stopped sleep 20 | false
3982 * bash-3.00# echo $?
3983 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3984 * [hush 1.14.0: yes we do it right]
3991 #if ENABLE_HUSH_FAST
3992 i = G.count_SIGCHLD;
3994 childpid = waitpid(-1, &status, attributes);
3995 if (childpid <= 0) {
3996 if (childpid && errno != ECHILD)
3997 bb_perror_msg("waitpid");
3998 #if ENABLE_HUSH_FAST
3999 else { /* Until next SIGCHLD, waitpid's are useless */
4000 G.we_have_children = (childpid == 0);
4001 G.handled_SIGCHLD = i;
4002 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4007 dead = WIFEXITED(status) || WIFSIGNALED(status);
4010 if (WIFSTOPPED(status))
4011 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
4012 childpid, WSTOPSIG(status), WEXITSTATUS(status));
4013 if (WIFSIGNALED(status))
4014 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
4015 childpid, WTERMSIG(status), WEXITSTATUS(status));
4016 if (WIFEXITED(status))
4017 debug_printf_jobs("pid %d exited, exitcode %d\n",
4018 childpid, WEXITSTATUS(status));
4020 /* Were we asked to wait for fg pipe? */
4022 for (i = 0; i < fg_pipe->num_cmds; i++) {
4023 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
4024 if (fg_pipe->cmds[i].pid != childpid)
4027 fg_pipe->cmds[i].pid = 0;
4028 fg_pipe->alive_cmds--;
4029 if (i == fg_pipe->num_cmds - 1) {
4030 /* last process gives overall exitstatus */
4031 rcode = WEXITSTATUS(status);
4032 /* bash prints killer signal's name for *last*
4033 * process in pipe (prints just newline for SIGINT).
4034 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
4036 if (WIFSIGNALED(status)) {
4037 int sig = WTERMSIG(status);
4038 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
4039 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
4040 * Maybe we need to use sig | 128? */
4043 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
4046 fg_pipe->cmds[i].is_stopped = 1;
4047 fg_pipe->stopped_cmds++;
4049 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
4050 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
4051 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
4052 /* All processes in fg pipe have exited or stopped */
4053 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4054 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4055 * and "killall -STOP cat" */
4056 if (G_interactive_fd) {
4058 if (fg_pipe->alive_cmds)
4059 insert_bg_job(fg_pipe);
4063 if (!fg_pipe->alive_cmds)
4066 /* There are still running processes in the fg pipe */
4067 goto wait_more; /* do waitpid again */
4069 /* it wasnt fg_pipe, look for process in bg pipes */
4073 /* We asked to wait for bg or orphaned children */
4074 /* No need to remember exitcode in this case */
4075 for (pi = G.job_list; pi; pi = pi->next) {
4076 for (i = 0; i < pi->num_cmds; i++) {
4077 if (pi->cmds[i].pid == childpid)
4078 goto found_pi_and_prognum;
4081 /* Happens when shell is used as init process (init=/bin/sh) */
4082 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4083 continue; /* do waitpid again */
4085 found_pi_and_prognum:
4088 pi->cmds[i].pid = 0;
4090 if (!pi->alive_cmds) {
4091 if (G_interactive_fd)
4092 printf(JOB_STATUS_FORMAT, pi->jobid,
4093 "Done", pi->cmdtext);
4094 delete_finished_bg_job(pi);
4098 pi->cmds[i].is_stopped = 1;
4102 } /* while (waitpid succeeds)... */
4108 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4111 int rcode = checkjobs(fg_pipe);
4112 if (G_saved_tty_pgrp) {
4113 /* Job finished, move the shell to the foreground */
4114 p = getpgrp(); /* our process group id */
4115 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4116 tcsetpgrp(G_interactive_fd, p);
4122 /* Start all the jobs, but don't wait for anything to finish.
4125 * Return code is normally -1, when the caller has to wait for children
4126 * to finish to determine the exit status of the pipe. If the pipe
4127 * is a simple builtin command, however, the action is done by the
4128 * time run_pipe returns, and the exit code is provided as the
4131 * Returns -1 only if started some children. IOW: we have to
4132 * mask out retvals of builtins etc with 0xff!
4134 * The only case when we do not need to [v]fork is when the pipe
4135 * is single, non-backgrounded, non-subshell command. Examples:
4136 * cmd ; ... { list } ; ...
4137 * cmd && ... { list } && ...
4138 * cmd || ... { list } || ...
4139 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4140 * or (if SH_STANDALONE) an applet, and we can run the { list }
4141 * with run_list. If it isn't one of these, we fork and exec cmd.
4143 * Cases when we must fork:
4144 * non-single: cmd | cmd
4145 * backgrounded: cmd & { list } &
4146 * subshell: ( list ) [&]
4148 static NOINLINE int run_pipe(struct pipe *pi)
4150 static const char *const null_ptr = NULL;
4153 struct command *command;
4154 char **argv_expanded;
4157 /* it is not always needed, but we aim to smaller code */
4158 int squirrel[] = { -1, -1, -1 };
4161 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4164 IF_HUSH_JOB(pi->pgrp = -1;)
4165 pi->stopped_cmds = 0;
4166 command = &(pi->cmds[0]);
4167 argv_expanded = NULL;
4169 if (pi->num_cmds != 1
4170 || pi->followup == PIPE_BG
4171 || command->cmd_type == CMD_SUBSHELL
4178 debug_printf_exec(": group:%p argv:'%s'\n",
4179 command->group, command->argv ? command->argv[0] : "NONE");
4181 if (command->group) {
4182 #if ENABLE_HUSH_FUNCTIONS
4183 if (command->cmd_type == CMD_FUNCDEF) {
4184 /* "executing" func () { list } */
4185 struct function *funcp;
4187 funcp = new_function(command->argv[0]);
4188 /* funcp->name is already set to argv[0] */
4189 funcp->body = command->group;
4191 funcp->body_as_string = command->group_as_string;
4192 command->group_as_string = NULL;
4194 command->group = NULL;
4195 command->argv[0] = NULL;
4196 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4197 funcp->parent_cmd = command;
4198 command->child_func = funcp;
4200 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4202 return EXIT_SUCCESS;
4206 debug_printf("non-subshell group\n");
4207 rcode = 1; /* exitcode if redir failed */
4208 if (setup_redirects(command, squirrel) == 0) {
4209 debug_printf_exec(": run_list\n");
4210 rcode = run_list(command->group) & 0xff;
4212 restore_redirects(squirrel);
4213 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4215 debug_printf_exec("run_pipe: return %d\n", rcode);
4219 argv = command->argv ? command->argv : (char **) &null_ptr;
4221 const struct built_in_command *x;
4222 #if ENABLE_HUSH_FUNCTIONS
4223 const struct function *funcp;
4227 char **new_env = NULL;
4228 struct variable *old_vars = NULL;
4230 if (argv[command->assignment_cnt] == NULL) {
4231 /* Assignments, but no command */
4232 /* Ensure redirects take effect (that is, create files).
4233 * Try "a=t >file": */
4234 rcode = setup_redirects(command, squirrel);
4235 restore_redirects(squirrel);
4236 /* Set shell variables */
4238 p = expand_string_to_string(*argv);
4239 debug_printf_exec("set shell var:'%s'->'%s'\n",
4241 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4244 /* Redirect error sets $? to 1. Othervise,
4245 * if evaluating assignment value set $?, retain it.
4246 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4248 rcode = G.last_exitcode;
4249 /* Do we need to flag set_local_var() errors?
4250 * "assignment to readonly var" and "putenv error"
4252 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4254 debug_printf_exec("run_pipe: return %d\n", rcode);
4258 /* Expand the rest into (possibly) many strings each */
4260 #if ENABLE_HUSH_BASH_COMPAT
4261 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4262 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4265 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4266 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4267 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4272 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4275 /* if someone gives us an empty string: `cmd with empty output` */
4276 if (!argv_expanded[0]) {
4277 free(argv_expanded);
4279 return G.last_exitcode;
4282 x = find_builtin(argv_expanded[0]);
4283 #if ENABLE_HUSH_FUNCTIONS
4286 funcp = find_function(argv_expanded[0]);
4290 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4291 debug_printf("exec with redirects only\n");
4292 rcode = setup_redirects(command, NULL);
4293 goto clean_up_and_ret1;
4296 /* setup_redirects acts on file descriptors, not FILEs.
4297 * This is perfect for work that comes after exec().
4298 * Is it really safe for inline use? Experimentally,
4299 * things seem to work. */
4300 rcode = setup_redirects(command, squirrel);
4302 new_env = expand_assignments(argv, command->assignment_cnt);
4303 old_vars = set_vars_and_save_old(new_env);
4305 debug_printf_exec(": builtin '%s' '%s'...\n",
4306 x->b_cmd, argv_expanded[1]);
4307 rcode = x->b_function(argv_expanded) & 0xff;
4310 #if ENABLE_HUSH_FUNCTIONS
4312 # if ENABLE_HUSH_LOCAL
4313 struct variable **sv;
4314 sv = G.shadowed_vars_pp;
4315 G.shadowed_vars_pp = &old_vars;
4317 debug_printf_exec(": function '%s' '%s'...\n",
4318 funcp->name, argv_expanded[1]);
4319 rcode = run_function(funcp, argv_expanded) & 0xff;
4320 # if ENABLE_HUSH_LOCAL
4321 G.shadowed_vars_pp = sv;
4326 #if ENABLE_FEATURE_SH_STANDALONE
4329 restore_redirects(squirrel);
4330 unset_vars(new_env);
4333 free(argv_expanded);
4334 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4336 debug_printf_exec("run_pipe return %d\n", rcode);
4340 #if ENABLE_FEATURE_SH_STANDALONE
4341 i = find_applet_by_name(argv_expanded[0]);
4342 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4343 rcode = setup_redirects(command, squirrel);
4345 new_env = expand_assignments(argv, command->assignment_cnt);
4346 old_vars = set_vars_and_save_old(new_env);
4347 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4348 argv_expanded[0], argv_expanded[1]);
4349 rcode = run_nofork_applet(i, argv_expanded);
4351 goto clean_up_and_ret;
4354 /* It is neither builtin nor applet. We must fork. */
4358 /* NB: argv_expanded may already be created, and that
4359 * might include `cmd` runs! Do not rerun it! We *must*
4360 * use argv_expanded if it's non-NULL */
4362 /* Going to fork a child per each pipe member */
4366 for (i = 0; i < pi->num_cmds; i++) {
4367 struct fd_pair pipefds;
4369 volatile nommu_save_t nommu_save;
4370 nommu_save.new_env = NULL;
4371 nommu_save.old_vars = NULL;
4372 nommu_save.argv = NULL;
4373 nommu_save.argv_from_re_execing = NULL;
4375 command = &(pi->cmds[i]);
4376 if (command->argv) {
4377 debug_printf_exec(": pipe member '%s' '%s'...\n",
4378 command->argv[0], command->argv[1]);
4380 debug_printf_exec(": pipe member with no argv\n");
4383 /* pipes are inserted between pairs of commands */
4386 if ((i + 1) < pi->num_cmds)
4387 xpiped_pair(pipefds);
4389 command->pid = BB_MMU ? fork() : vfork();
4390 if (!command->pid) { /* child */
4392 disable_restore_tty_pgrp_on_exit();
4393 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4395 /* Every child adds itself to new process group
4396 * with pgid == pid_of_first_child_in_pipe */
4397 if (G.run_list_level == 1 && G_interactive_fd) {
4400 if (pgrp < 0) /* true for 1st process only */
4402 if (setpgid(0, pgrp) == 0
4403 && pi->followup != PIPE_BG
4404 && G_saved_tty_pgrp /* we have ctty */
4406 /* We do it in *every* child, not just first,
4408 tcsetpgrp(G_interactive_fd, pgrp);
4412 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4413 /* 1st cmd in backgrounded pipe
4414 * should have its stdin /dev/null'ed */
4416 if (open(bb_dev_null, O_RDONLY))
4417 xopen("/", O_RDONLY);
4419 xmove_fd(nextin, 0);
4421 xmove_fd(pipefds.wr, 1);
4424 /* Like bash, explicit redirects override pipes,
4425 * and the pipe fd is available for dup'ing. */
4426 if (setup_redirects(command, NULL))
4429 /* Restore default handlers just prior to exec */
4430 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4432 /* Stores to nommu_save list of env vars putenv'ed
4433 * (NOMMU, on MMU we don't need that) */
4434 /* cast away volatility... */
4435 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4436 /* pseudo_exec() does not return */
4439 /* parent or error */
4440 #if ENABLE_HUSH_FAST
4442 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4444 enable_restore_tty_pgrp_on_exit();
4446 /* Clean up after vforked child */
4447 free(nommu_save.argv);
4448 free(nommu_save.argv_from_re_execing);
4449 unset_vars(nommu_save.new_env);
4450 add_vars(nommu_save.old_vars);
4452 free(argv_expanded);
4453 argv_expanded = NULL;
4454 if (command->pid < 0) { /* [v]fork failed */
4455 /* Clearly indicate, was it fork or vfork */
4456 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4460 /* Second and next children need to know pid of first one */
4462 pi->pgrp = command->pid;
4468 if ((i + 1) < pi->num_cmds)
4470 /* Pass read (output) pipe end to next iteration */
4471 nextin = pipefds.rd;
4474 if (!pi->alive_cmds) {
4476 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4481 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4485 #ifndef debug_print_tree
4486 static void debug_print_tree(struct pipe *pi, int lvl)
4488 static const char *const PIPE[] = {
4494 static const char *RES[] = {
4495 [RES_NONE ] = "NONE" ,
4498 [RES_THEN ] = "THEN" ,
4499 [RES_ELIF ] = "ELIF" ,
4500 [RES_ELSE ] = "ELSE" ,
4503 # if ENABLE_HUSH_LOOPS
4504 [RES_FOR ] = "FOR" ,
4505 [RES_WHILE] = "WHILE",
4506 [RES_UNTIL] = "UNTIL",
4508 [RES_DONE ] = "DONE" ,
4510 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4513 # if ENABLE_HUSH_CASE
4514 [RES_CASE ] = "CASE" ,
4515 [RES_CASE_IN ] = "CASE_IN" ,
4516 [RES_MATCH] = "MATCH",
4517 [RES_CASE_BODY] = "CASE_BODY",
4518 [RES_ESAC ] = "ESAC" ,
4520 [RES_XXXX ] = "XXXX" ,
4521 [RES_SNTX ] = "SNTX" ,
4523 static const char *const CMDTYPE[] = {
4527 # if ENABLE_HUSH_FUNCTIONS
4536 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4537 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4539 while (prn < pi->num_cmds) {
4540 struct command *command = &pi->cmds[prn];
4541 char **argv = command->argv;
4543 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4545 command->assignment_cnt);
4546 if (command->group) {
4547 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4548 CMDTYPE[command->cmd_type],
4551 , " group_as_string:", command->group_as_string
4556 debug_print_tree(command->group, lvl+1);
4560 if (argv) while (*argv) {
4561 fprintf(stderr, " '%s'", *argv);
4564 fprintf(stderr, "\n");
4571 #endif /* debug_print_tree */
4573 /* NB: called by pseudo_exec, and therefore must not modify any
4574 * global data until exec/_exit (we can be a child after vfork!) */
4575 static int run_list(struct pipe *pi)
4577 #if ENABLE_HUSH_CASE
4578 char *case_word = NULL;
4580 #if ENABLE_HUSH_LOOPS
4581 struct pipe *loop_top = NULL;
4582 char **for_lcur = NULL;
4583 char **for_list = NULL;
4585 smallint last_followup;
4587 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4588 smalluint cond_code = 0;
4590 enum { cond_code = 0 };
4593 smallint rword; /* enum reserved_style */
4594 smallint last_rword; /* ditto */
4597 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4600 #if ENABLE_HUSH_LOOPS
4601 /* Check syntax for "for" */
4602 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4603 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4605 /* current word is FOR or IN (BOLD in comments below) */
4606 if (cpipe->next == NULL) {
4607 syntax_error("malformed for");
4609 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4612 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4613 if (cpipe->next->res_word == RES_DO)
4615 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4616 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4617 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4619 syntax_error("malformed for");
4621 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4627 /* Past this point, all code paths should jump to ret: label
4628 * in order to return, no direct "return" statements please.
4629 * This helps to ensure that no memory is leaked. */
4637 last_rword = RES_XXXX;
4639 last_followup = PIPE_SEQ;
4640 rcode = G.last_exitcode;
4642 /* Go through list of pipes, (maybe) executing them. */
4643 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4647 IF_HAS_KEYWORDS(rword = pi->res_word;)
4648 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4649 rword, cond_code, last_rword);
4650 #if ENABLE_HUSH_LOOPS
4651 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4652 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4654 /* start of a loop: remember where loop starts */
4659 /* Still in the same "if...", "then..." or "do..." branch? */
4660 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4661 if ((rcode == 0 && last_followup == PIPE_OR)
4662 || (rcode != 0 && last_followup == PIPE_AND)
4664 /* It is "<true> || CMD" or "<false> && CMD"
4665 * and we should not execute CMD */
4666 debug_printf_exec("skipped cmd because of || or &&\n");
4667 last_followup = pi->followup;
4671 last_followup = pi->followup;
4672 IF_HAS_KEYWORDS(last_rword = rword;)
4675 if (rword == RES_THEN) {
4676 /* if false; then ... fi has exitcode 0! */
4677 G.last_exitcode = rcode = EXIT_SUCCESS;
4678 /* "if <false> THEN cmd": skip cmd */
4682 if (rword == RES_ELSE || rword == RES_ELIF) {
4683 /* "if <true> then ... ELSE/ELIF cmd":
4684 * skip cmd and all following ones */
4689 #if ENABLE_HUSH_LOOPS
4690 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4692 /* first loop through for */
4694 static const char encoded_dollar_at[] ALIGN1 = {
4695 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4696 }; /* encoded representation of "$@" */
4697 static const char *const encoded_dollar_at_argv[] = {
4698 encoded_dollar_at, NULL
4699 }; /* argv list with one element: "$@" */
4702 vals = (char**)encoded_dollar_at_argv;
4703 if (pi->next->res_word == RES_IN) {
4704 /* if no variable values after "in" we skip "for" */
4705 if (!pi->next->cmds[0].argv) {
4706 G.last_exitcode = rcode = EXIT_SUCCESS;
4707 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4710 vals = pi->next->cmds[0].argv;
4711 } /* else: "for var; do..." -> assume "$@" list */
4712 /* create list of variable values */
4713 debug_print_strings("for_list made from", vals);
4714 for_list = expand_strvec_to_strvec(vals);
4715 for_lcur = for_list;
4716 debug_print_strings("for_list", for_list);
4719 /* "for" loop is over, clean up */
4725 /* Insert next value from for_lcur */
4726 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4727 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4730 if (rword == RES_IN) {
4731 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4733 if (rword == RES_DONE) {
4734 continue; /* "done" has no cmds too */
4737 #if ENABLE_HUSH_CASE
4738 if (rword == RES_CASE) {
4739 case_word = expand_strvec_to_string(pi->cmds->argv);
4742 if (rword == RES_MATCH) {
4745 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4747 /* all prev words didn't match, does this one match? */
4748 argv = pi->cmds->argv;
4750 char *pattern = expand_string_to_string(*argv);
4751 /* TODO: which FNM_xxx flags to use? */
4752 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4754 if (cond_code == 0) { /* match! we will execute this branch */
4755 free(case_word); /* make future "word)" stop */
4763 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4765 continue; /* not matched yet, skip this pipe */
4768 /* Just pressing <enter> in shell should check for jobs.
4769 * OTOH, in non-interactive shell this is useless
4770 * and only leads to extra job checks */
4771 if (pi->num_cmds == 0) {
4772 if (G_interactive_fd)
4773 goto check_jobs_and_continue;
4777 /* After analyzing all keywords and conditions, we decided
4778 * to execute this pipe. NB: have to do checkjobs(NULL)
4779 * after run_pipe to collect any background children,
4780 * even if list execution is to be stopped. */
4781 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4784 #if ENABLE_HUSH_LOOPS
4785 G.flag_break_continue = 0;
4787 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4789 /* We ran a builtin, function, or group.
4790 * rcode is already known
4791 * and we don't need to wait for anything. */
4792 G.last_exitcode = rcode;
4793 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4794 check_and_run_traps(0);
4795 #if ENABLE_HUSH_LOOPS
4796 /* Was it "break" or "continue"? */
4797 if (G.flag_break_continue) {
4798 smallint fbc = G.flag_break_continue;
4799 /* We might fall into outer *loop*,
4800 * don't want to break it too */
4802 G.depth_break_continue--;
4803 if (G.depth_break_continue == 0)
4804 G.flag_break_continue = 0;
4805 /* else: e.g. "continue 2" should *break* once, *then* continue */
4806 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4807 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4808 goto check_jobs_and_break;
4809 /* "continue": simulate end of loop */
4814 #if ENABLE_HUSH_FUNCTIONS
4815 if (G.flag_return_in_progress == 1) {
4816 /* same as "goto check_jobs_and_break" */
4821 } else if (pi->followup == PIPE_BG) {
4822 /* What does bash do with attempts to background builtins? */
4823 /* even bash 3.2 doesn't do that well with nested bg:
4824 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4825 * I'm NOT treating inner &'s as jobs */
4826 check_and_run_traps(0);
4828 if (G.run_list_level == 1)
4831 G.last_exitcode = rcode = EXIT_SUCCESS;
4832 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4835 if (G.run_list_level == 1 && G_interactive_fd) {
4836 /* Waits for completion, then fg's main shell */
4837 rcode = checkjobs_and_fg_shell(pi);
4838 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4839 check_and_run_traps(0);
4842 { /* This one just waits for completion */
4843 rcode = checkjobs(pi);
4844 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4845 check_and_run_traps(0);
4847 G.last_exitcode = rcode;
4851 /* Analyze how result affects subsequent commands */
4853 if (rword == RES_IF || rword == RES_ELIF)
4856 #if ENABLE_HUSH_LOOPS
4857 /* Beware of "while false; true; do ..."! */
4858 if (pi->next && pi->next->res_word == RES_DO) {
4859 if (rword == RES_WHILE) {
4861 /* "while false; do...done" - exitcode 0 */
4862 G.last_exitcode = rcode = EXIT_SUCCESS;
4863 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4864 goto check_jobs_and_break;
4867 if (rword == RES_UNTIL) {
4869 debug_printf_exec(": until expr is true: breaking\n");
4870 check_jobs_and_break:
4878 check_jobs_and_continue:
4885 #if ENABLE_HUSH_LOOPS
4890 #if ENABLE_HUSH_CASE
4894 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4898 /* Select which version we will use */
4899 static int run_and_free_list(struct pipe *pi)
4902 debug_printf_exec("run_and_free_list entered\n");
4904 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4905 rcode = run_list(pi);
4907 /* free_pipe_list has the side effect of clearing memory.
4908 * In the long run that function can be merged with run_list,
4909 * but doing that now would hobble the debugging effort. */
4911 debug_printf_exec("run_and_free_list return %d\n", rcode);
4916 static struct pipe *new_pipe(void)
4919 pi = xzalloc(sizeof(struct pipe));
4920 /*pi->followup = 0; - deliberately invalid value */
4921 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4925 /* Command (member of a pipe) is complete, or we start a new pipe
4926 * if ctx->command is NULL.
4927 * No errors possible here.
4929 static int done_command(struct parse_context *ctx)
4931 /* The command is really already in the pipe structure, so
4932 * advance the pipe counter and make a new, null command. */
4933 struct pipe *pi = ctx->pipe;
4934 struct command *command = ctx->command;
4937 if (IS_NULL_CMD(command)) {
4938 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4942 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4943 //debug_print_tree(ctx->list_head, 20);
4945 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4948 /* Only real trickiness here is that the uncommitted
4949 * command structure is not counted in pi->num_cmds. */
4950 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4951 ctx->command = command = &pi->cmds[pi->num_cmds];
4953 memset(command, 0, sizeof(*command));
4954 return pi->num_cmds; /* used only for 0/nonzero check */
4957 static void done_pipe(struct parse_context *ctx, pipe_style type)
4961 debug_printf_parse("done_pipe entered, followup %d\n", type);
4962 /* Close previous command */
4963 not_null = done_command(ctx);
4964 ctx->pipe->followup = type;
4966 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4967 ctx->ctx_inverted = 0;
4968 ctx->pipe->res_word = ctx->ctx_res_w;
4971 /* Without this check, even just <enter> on command line generates
4972 * tree of three NOPs (!). Which is harmless but annoying.
4973 * IOW: it is safe to do it unconditionally. */
4976 || ctx->ctx_res_w == RES_FI
4978 #if ENABLE_HUSH_LOOPS
4979 || ctx->ctx_res_w == RES_DONE
4980 || ctx->ctx_res_w == RES_FOR
4981 || ctx->ctx_res_w == RES_IN
4983 #if ENABLE_HUSH_CASE
4984 || ctx->ctx_res_w == RES_ESAC
4988 debug_printf_parse("done_pipe: adding new pipe: "
4989 "not_null:%d ctx->ctx_res_w:%d\n",
4990 not_null, ctx->ctx_res_w);
4992 ctx->pipe->next = new_p;
4994 /* RES_THEN, RES_DO etc are "sticky" -
4995 * they remain set for pipes inside if/while.
4996 * This is used to control execution.
4997 * RES_FOR and RES_IN are NOT sticky (needed to support
4998 * cases where variable or value happens to match a keyword):
5000 #if ENABLE_HUSH_LOOPS
5001 if (ctx->ctx_res_w == RES_FOR
5002 || ctx->ctx_res_w == RES_IN)
5003 ctx->ctx_res_w = RES_NONE;
5005 #if ENABLE_HUSH_CASE
5006 if (ctx->ctx_res_w == RES_MATCH)
5007 ctx->ctx_res_w = RES_CASE_BODY;
5008 if (ctx->ctx_res_w == RES_CASE)
5009 ctx->ctx_res_w = RES_CASE_IN;
5011 ctx->command = NULL; /* trick done_command below */
5012 /* Create the memory for command, roughly:
5013 * ctx->pipe->cmds = new struct command;
5014 * ctx->command = &ctx->pipe->cmds[0];
5017 //debug_print_tree(ctx->list_head, 10);
5019 debug_printf_parse("done_pipe return\n");
5022 static void initialize_context(struct parse_context *ctx)
5024 memset(ctx, 0, sizeof(*ctx));
5025 ctx->pipe = ctx->list_head = new_pipe();
5026 /* Create the memory for command, roughly:
5027 * ctx->pipe->cmds = new struct command;
5028 * ctx->command = &ctx->pipe->cmds[0];
5033 /* If a reserved word is found and processed, parse context is modified
5034 * and 1 is returned.
5037 struct reserved_combo {
5040 unsigned char assignment_flag;
5044 FLAG_END = (1 << RES_NONE ),
5046 FLAG_IF = (1 << RES_IF ),
5047 FLAG_THEN = (1 << RES_THEN ),
5048 FLAG_ELIF = (1 << RES_ELIF ),
5049 FLAG_ELSE = (1 << RES_ELSE ),
5050 FLAG_FI = (1 << RES_FI ),
5052 # if ENABLE_HUSH_LOOPS
5053 FLAG_FOR = (1 << RES_FOR ),
5054 FLAG_WHILE = (1 << RES_WHILE),
5055 FLAG_UNTIL = (1 << RES_UNTIL),
5056 FLAG_DO = (1 << RES_DO ),
5057 FLAG_DONE = (1 << RES_DONE ),
5058 FLAG_IN = (1 << RES_IN ),
5060 # if ENABLE_HUSH_CASE
5061 FLAG_MATCH = (1 << RES_MATCH),
5062 FLAG_ESAC = (1 << RES_ESAC ),
5064 FLAG_START = (1 << RES_XXXX ),
5067 static const struct reserved_combo* match_reserved_word(o_string *word)
5069 /* Mostly a list of accepted follow-up reserved words.
5070 * FLAG_END means we are done with the sequence, and are ready
5071 * to turn the compound list into a command.
5072 * FLAG_START means the word must start a new compound list.
5074 static const struct reserved_combo reserved_list[] = {
5076 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5077 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5078 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5079 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5080 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5081 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5083 # if ENABLE_HUSH_LOOPS
5084 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5085 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5086 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5087 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5088 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5089 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5091 # if ENABLE_HUSH_CASE
5092 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5093 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5096 const struct reserved_combo *r;
5098 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5099 if (strcmp(word->data, r->literal) == 0)
5104 /* Return 0: not a keyword, 1: keyword
5106 static int reserved_word(o_string *word, struct parse_context *ctx)
5108 # if ENABLE_HUSH_CASE
5109 static const struct reserved_combo reserved_match = {
5110 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5113 const struct reserved_combo *r;
5117 r = match_reserved_word(word);
5121 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5122 # if ENABLE_HUSH_CASE
5123 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5124 /* "case word IN ..." - IN part starts first MATCH part */
5125 r = &reserved_match;
5128 if (r->flag == 0) { /* '!' */
5129 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5130 syntax_error("! ! command");
5131 ctx->ctx_res_w = RES_SNTX;
5133 ctx->ctx_inverted = 1;
5136 if (r->flag & FLAG_START) {
5137 struct parse_context *old;
5139 old = xmalloc(sizeof(*old));
5140 debug_printf_parse("push stack %p\n", old);
5141 *old = *ctx; /* physical copy */
5142 initialize_context(ctx);
5144 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5145 syntax_error_at(word->data);
5146 ctx->ctx_res_w = RES_SNTX;
5149 /* "{...} fi" is ok. "{...} if" is not
5151 * if { echo foo; } then { echo bar; } fi */
5152 if (ctx->command->group)
5153 done_pipe(ctx, PIPE_SEQ);
5156 ctx->ctx_res_w = r->res;
5157 ctx->old_flag = r->flag;
5158 word->o_assignment = r->assignment_flag;
5160 if (ctx->old_flag & FLAG_END) {
5161 struct parse_context *old;
5163 done_pipe(ctx, PIPE_SEQ);
5164 debug_printf_parse("pop stack %p\n", ctx->stack);
5166 old->command->group = ctx->list_head;
5167 old->command->cmd_type = CMD_NORMAL;
5169 o_addstr(&old->as_string, ctx->as_string.data);
5170 o_free_unsafe(&ctx->as_string);
5171 old->command->group_as_string = xstrdup(old->as_string.data);
5172 debug_printf_parse("pop, remembering as:'%s'\n",
5173 old->command->group_as_string);
5175 *ctx = *old; /* physical copy */
5180 #endif /* HAS_KEYWORDS */
5182 /* Word is complete, look at it and update parsing context.
5183 * Normal return is 0. Syntax errors return 1.
5184 * Note: on return, word is reset, but not o_free'd!
5186 static int done_word(o_string *word, struct parse_context *ctx)
5188 struct command *command = ctx->command;
5190 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5191 if (word->length == 0 && word->o_quoted == 0) {
5192 debug_printf_parse("done_word return 0: true null, ignored\n");
5196 if (ctx->pending_redirect) {
5197 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5198 * only if run as "bash", not "sh" */
5199 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5201 * ...the word that follows the redirection operator
5202 * shall be subjected to tilde expansion, parameter expansion,
5203 * command substitution, arithmetic expansion, and quote
5204 * removal. Pathname expansion shall not be performed
5205 * on the word by a non-interactive shell; an interactive
5206 * shell may perform it, but shall do so only when
5207 * the expansion would result in one word."
5209 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5210 /* Cater for >\file case:
5211 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5212 * Same with heredocs:
5213 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5215 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5216 unbackslash(ctx->pending_redirect->rd_filename);
5217 /* Is it <<"HEREDOC"? */
5218 if (word->o_quoted) {
5219 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5222 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5223 ctx->pending_redirect = NULL;
5225 /* If this word wasn't an assignment, next ones definitely
5226 * can't be assignments. Even if they look like ones. */
5227 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5228 && word->o_assignment != WORD_IS_KEYWORD
5230 word->o_assignment = NOT_ASSIGNMENT;
5232 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5233 command->assignment_cnt++;
5234 word->o_assignment = MAYBE_ASSIGNMENT;
5238 # if ENABLE_HUSH_CASE
5239 if (ctx->ctx_dsemicolon
5240 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5242 /* already done when ctx_dsemicolon was set to 1: */
5243 /* ctx->ctx_res_w = RES_MATCH; */
5244 ctx->ctx_dsemicolon = 0;
5247 if (!command->argv /* if it's the first word... */
5248 # if ENABLE_HUSH_LOOPS
5249 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5250 && ctx->ctx_res_w != RES_IN
5252 # if ENABLE_HUSH_CASE
5253 && ctx->ctx_res_w != RES_CASE
5256 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5257 if (reserved_word(word, ctx)) {
5258 o_reset_to_empty_unquoted(word);
5259 debug_printf_parse("done_word return %d\n",
5260 (ctx->ctx_res_w == RES_SNTX));
5261 return (ctx->ctx_res_w == RES_SNTX);
5263 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5264 if (strcmp(word->data, "export") == 0
5265 # if ENABLE_HUSH_LOCAL
5266 || strcmp(word->data, "local") == 0
5269 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5272 # if ENABLE_HUSH_BASH_COMPAT
5273 if (strcmp(word->data, "[[") == 0) {
5274 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5280 if (command->group) {
5281 /* "{ echo foo; } echo bar" - bad */
5282 syntax_error_at(word->data);
5283 debug_printf_parse("done_word return 1: syntax error, "
5284 "groups and arglists don't mix\n");
5287 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5288 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5289 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5290 /* (otherwise it's known to be not empty and is already safe) */
5292 /* exclude "$@" - it can expand to no word despite "" */
5293 char *p = word->data;
5294 while (p[0] == SPECIAL_VAR_SYMBOL
5295 && (p[1] & 0x7f) == '@'
5296 && p[2] == SPECIAL_VAR_SYMBOL
5300 if (p == word->data || p[0] != '\0') {
5301 /* saw no "$@", or not only "$@" but some
5302 * real text is there too */
5303 /* insert "empty variable" reference, this makes
5304 * e.g. "", $empty"" etc to not disappear */
5305 o_addchr(word, SPECIAL_VAR_SYMBOL);
5306 o_addchr(word, SPECIAL_VAR_SYMBOL);
5309 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5310 debug_print_strings("word appended to argv", command->argv);
5313 #if ENABLE_HUSH_LOOPS
5314 if (ctx->ctx_res_w == RES_FOR) {
5316 || !is_well_formed_var_name(command->argv[0], '\0')
5318 /* bash says just "not a valid identifier" */
5319 syntax_error("not a valid identifier in for");
5322 /* Force FOR to have just one word (variable name) */
5323 /* NB: basically, this makes hush see "for v in ..."
5324 * syntax as if it is "for v; in ...". FOR and IN become
5325 * two pipe structs in parse tree. */
5326 done_pipe(ctx, PIPE_SEQ);
5329 #if ENABLE_HUSH_CASE
5330 /* Force CASE to have just one word */
5331 if (ctx->ctx_res_w == RES_CASE) {
5332 done_pipe(ctx, PIPE_SEQ);
5336 o_reset_to_empty_unquoted(word);
5338 debug_printf_parse("done_word return 0\n");
5343 /* Peek ahead in the input to find out if we have a "&n" construct,
5344 * as in "2>&1", that represents duplicating a file descriptor.
5346 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5347 * REDIRFD_SYNTAX_ERR if syntax error,
5348 * REDIRFD_TO_FILE if no & was seen,
5349 * or the number found.
5352 #define parse_redir_right_fd(as_string, input) \
5353 parse_redir_right_fd(input)
5355 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5361 return REDIRFD_TO_FILE;
5363 ch = i_getch(input); /* get the & */
5364 nommu_addchr(as_string, ch);
5367 ch = i_getch(input);
5368 nommu_addchr(as_string, ch);
5369 return REDIRFD_CLOSE;
5373 while (ch != EOF && isdigit(ch)) {
5374 d = d*10 + (ch-'0');
5376 ch = i_getch(input);
5377 nommu_addchr(as_string, ch);
5382 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5384 bb_error_msg("ambiguous redirect");
5385 return REDIRFD_SYNTAX_ERR;
5388 /* Return code is 0 normal, 1 if a syntax error is detected
5390 static int parse_redirect(struct parse_context *ctx,
5393 struct in_str *input)
5395 struct command *command = ctx->command;
5396 struct redir_struct *redir;
5397 struct redir_struct **redirp;
5400 dup_num = REDIRFD_TO_FILE;
5401 if (style != REDIRECT_HEREDOC) {
5402 /* Check for a '>&1' type redirect */
5403 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5404 if (dup_num == REDIRFD_SYNTAX_ERR)
5407 int ch = i_peek(input);
5408 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5409 if (dup_num) { /* <<-... */
5410 ch = i_getch(input);
5411 nommu_addchr(&ctx->as_string, ch);
5416 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5417 int ch = i_peek(input);
5419 /* >|FILE redirect ("clobbering" >).
5420 * Since we do not support "set -o noclobber" yet,
5421 * >| and > are the same for now. Just eat |.
5423 ch = i_getch(input);
5424 nommu_addchr(&ctx->as_string, ch);
5428 /* Create a new redir_struct and append it to the linked list */
5429 redirp = &command->redirects;
5430 while ((redir = *redirp) != NULL) {
5431 redirp = &(redir->next);
5433 *redirp = redir = xzalloc(sizeof(*redir));
5434 /* redir->next = NULL; */
5435 /* redir->rd_filename = NULL; */
5436 redir->rd_type = style;
5437 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5439 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5440 redir_table[style].descrip);
5442 redir->rd_dup = dup_num;
5443 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5444 /* Erik had a check here that the file descriptor in question
5445 * is legit; I postpone that to "run time"
5446 * A "-" representation of "close me" shows up as a -3 here */
5447 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5448 redir->rd_fd, redir->rd_dup);
5450 /* Set ctx->pending_redirect, so we know what to do at the
5451 * end of the next parsed word. */
5452 ctx->pending_redirect = redir;
5457 /* If a redirect is immediately preceded by a number, that number is
5458 * supposed to tell which file descriptor to redirect. This routine
5459 * looks for such preceding numbers. In an ideal world this routine
5460 * needs to handle all the following classes of redirects...
5461 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5462 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5463 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5464 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5466 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5468 * ... If n is quoted, the number shall not be recognized as part of
5469 * the redirection expression. For example:
5471 * writes the character 2 into file a"
5472 * We are getting it right by setting ->o_quoted on any \<char>
5474 * A -1 return means no valid number was found,
5475 * the caller should use the appropriate default for this redirection.
5477 static int redirect_opt_num(o_string *o)
5481 if (o->data == NULL)
5483 num = bb_strtou(o->data, NULL, 10);
5484 if (errno || num < 0)
5486 o_reset_to_empty_unquoted(o);
5491 #define fetch_till_str(as_string, input, word, skip_tabs) \
5492 fetch_till_str(input, word, skip_tabs)
5494 static char *fetch_till_str(o_string *as_string,
5495 struct in_str *input,
5499 o_string heredoc = NULL_O_STRING;
5505 ch = i_getch(input);
5506 nommu_addchr(as_string, ch);
5508 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5509 heredoc.data[past_EOL] = '\0';
5510 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5511 return heredoc.data;
5514 o_addchr(&heredoc, ch);
5515 past_EOL = heredoc.length;
5518 ch = i_getch(input);
5519 nommu_addchr(as_string, ch);
5520 } while (skip_tabs && ch == '\t');
5521 } while (ch == '\n');
5524 o_free_unsafe(&heredoc);
5527 o_addchr(&heredoc, ch);
5528 nommu_addchr(as_string, ch);
5532 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5533 * and load them all. There should be exactly heredoc_cnt of them.
5535 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5537 struct pipe *pi = ctx->list_head;
5539 while (pi && heredoc_cnt) {
5541 struct command *cmd = pi->cmds;
5543 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5545 cmd->argv ? cmd->argv[0] : "NONE");
5546 for (i = 0; i < pi->num_cmds; i++) {
5547 struct redir_struct *redir = cmd->redirects;
5549 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5550 i, cmd->argv ? cmd->argv[0] : "NONE");
5552 if (redir->rd_type == REDIRECT_HEREDOC) {
5555 redir->rd_type = REDIRECT_HEREDOC2;
5556 /* redir->rd_dup is (ab)used to indicate <<- */
5557 p = fetch_till_str(&ctx->as_string, input,
5558 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5560 syntax_error("unexpected EOF in here document");
5563 free(redir->rd_filename);
5564 redir->rd_filename = p;
5567 redir = redir->next;
5574 /* Should be 0. If it isn't, it's a parse error */
5576 bb_error_msg_and_die("heredoc BUG 2");
5582 #if ENABLE_HUSH_TICK
5583 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5588 char **to_free = NULL;
5592 pid = BB_MMU ? fork() : vfork();
5594 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5596 if (pid == 0) { /* child */
5597 disable_restore_tty_pgrp_on_exit();
5598 /* Process substitution is not considered to be usual
5599 * 'command execution'.
5600 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5607 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5608 close(channel[0]); /* NB: close _first_, then move fd! */
5609 xmove_fd(channel[1], 1);
5610 /* Prevent it from trying to handle ctrl-z etc */
5611 IF_HUSH_JOB(G.run_list_level = 1;)
5612 /* Awful hack for `trap` or $(trap).
5614 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5615 * contains an example where "trap" is executed in a subshell:
5617 * save_traps=$(trap)
5619 * eval "$save_traps"
5621 * Standard does not say that "trap" in subshell shall print
5622 * parent shell's traps. It only says that its output
5623 * must have suitable form, but then, in the above example
5624 * (which is not supposed to be normative), it implies that.
5626 * bash (and probably other shell) does implement it
5627 * (traps are reset to defaults, but "trap" still shows them),
5628 * but as a result, "trap" logic is hopelessly messed up:
5631 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5632 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5633 * # true | trap <--- trap is in subshell - no output (ditto)
5634 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5635 * trap -- 'echo Ho' SIGWINCH
5636 * # echo `(trap)` <--- in subshell in subshell - output
5637 * trap -- 'echo Ho' SIGWINCH
5638 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5639 * trap -- 'echo Ho' SIGWINCH
5641 * The rules when to forget and when to not forget traps
5642 * get really complex and nonsensical.
5644 * Our solution: ONLY bare $(trap) or `trap` is special.
5646 s = skip_whitespace(s);
5647 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5649 static const char *const argv[] = { NULL, NULL };
5650 builtin_trap((char**)argv);
5651 exit(0); /* not _exit() - we need to fflush */
5654 reset_traps_to_defaults();
5655 parse_and_run_string(s);
5656 _exit(G.last_exitcode);
5658 /* We re-execute after vfork on NOMMU. This makes this script safe:
5659 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5660 * huge=`cat BIG` # was blocking here forever
5663 re_execute_shell(&to_free,
5673 # if ENABLE_HUSH_FAST
5675 //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);
5677 enable_restore_tty_pgrp_on_exit();
5682 close_on_exec_on(channel[0]);
5683 return xfdopen_for_read(channel[0]);
5686 /* Return code is exit status of the process that is run. */
5687 static int process_command_subs(o_string *dest, const char *s)
5690 struct in_str pipe_str;
5692 int status, ch, eol_cnt;
5694 fp = generate_stream_from_string(s, &pid);
5696 /* Now send results of command back into original context */
5697 setup_file_in_str(&pipe_str, fp);
5699 while ((ch = i_getch(&pipe_str)) != EOF) {
5705 o_addchr(dest, '\n');
5708 o_addQchr(dest, ch);
5711 debug_printf("done reading from `cmd` pipe, closing it\n");
5713 /* We need to extract exitcode. Test case
5714 * "true; echo `sleep 1; false` $?"
5716 safe_waitpid(pid, &status, 0);
5717 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5718 return WEXITSTATUS(status);
5720 #endif /* ENABLE_HUSH_TICK */
5722 #if !ENABLE_HUSH_FUNCTIONS
5723 #define parse_group(dest, ctx, input, ch) \
5724 parse_group(ctx, input, ch)
5726 static int parse_group(o_string *dest, struct parse_context *ctx,
5727 struct in_str *input, int ch)
5729 /* dest contains characters seen prior to ( or {.
5730 * Typically it's empty, but for function defs,
5731 * it contains function name (without '()'). */
5732 struct pipe *pipe_list;
5734 struct command *command = ctx->command;
5736 debug_printf_parse("parse_group entered\n");
5737 #if ENABLE_HUSH_FUNCTIONS
5738 if (ch == '(' && !dest->o_quoted) {
5740 if (done_word(dest, ctx))
5743 goto skip; /* (... */
5744 if (command->argv[1]) { /* word word ... (... */
5745 syntax_error_unexpected_ch('(');
5748 /* it is "word(..." or "word (..." */
5750 ch = i_getch(input);
5751 while (ch == ' ' || ch == '\t');
5753 syntax_error_unexpected_ch(ch);
5756 nommu_addchr(&ctx->as_string, ch);
5758 ch = i_getch(input);
5759 while (ch == ' ' || ch == '\t' || ch == '\n');
5761 syntax_error_unexpected_ch(ch);
5764 nommu_addchr(&ctx->as_string, ch);
5765 command->cmd_type = CMD_FUNCDEF;
5770 #if 0 /* Prevented by caller */
5771 if (command->argv /* word [word]{... */
5772 || dest->length /* word{... */
5773 || dest->o_quoted /* ""{... */
5776 debug_printf_parse("parse_group return 1: "
5777 "syntax error, groups and arglists don't mix\n");
5782 #if ENABLE_HUSH_FUNCTIONS
5788 command->cmd_type = CMD_SUBSHELL;
5790 /* bash does not allow "{echo...", requires whitespace */
5791 ch = i_getch(input);
5792 if (ch != ' ' && ch != '\t' && ch != '\n') {
5793 syntax_error_unexpected_ch(ch);
5796 nommu_addchr(&ctx->as_string, ch);
5801 # define as_string NULL
5803 char *as_string = NULL;
5805 pipe_list = parse_stream(&as_string, input, endch);
5808 o_addstr(&ctx->as_string, as_string);
5810 /* empty ()/{} or parse error? */
5811 if (!pipe_list || pipe_list == ERR_PTR) {
5812 /* parse_stream already emitted error msg */
5815 debug_printf_parse("parse_group return 1: "
5816 "parse_stream returned %p\n", pipe_list);
5819 command->group = pipe_list;
5821 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5822 command->group_as_string = as_string;
5823 debug_printf_parse("end of group, remembering as:'%s'\n",
5824 command->group_as_string);
5828 debug_printf_parse("parse_group return 0\n");
5830 /* command remains "open", available for possible redirects */
5833 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5834 /* Subroutines for copying $(...) and `...` things */
5835 static void add_till_backquote(o_string *dest, struct in_str *input);
5837 static void add_till_single_quote(o_string *dest, struct in_str *input)
5840 int ch = i_getch(input);
5842 syntax_error_unterm_ch('\'');
5843 /*xfunc_die(); - redundant */
5850 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5851 static void add_till_double_quote(o_string *dest, struct in_str *input)
5854 int ch = i_getch(input);
5856 syntax_error_unterm_ch('"');
5857 /*xfunc_die(); - redundant */
5861 if (ch == '\\') { /* \x. Copy both chars. */
5863 ch = i_getch(input);
5867 add_till_backquote(dest, input);
5871 //if (ch == '$') ...
5874 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5876 * "Within the backquoted style of command substitution, backslash
5877 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5878 * The search for the matching backquote shall be satisfied by the first
5879 * backquote found without a preceding backslash; during this search,
5880 * if a non-escaped backquote is encountered within a shell comment,
5881 * a here-document, an embedded command substitution of the $(command)
5882 * form, or a quoted string, undefined results occur. A single-quoted
5883 * or double-quoted string that begins, but does not end, within the
5884 * "`...`" sequence produces undefined results."
5886 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5888 static void add_till_backquote(o_string *dest, struct in_str *input)
5891 int ch = i_getch(input);
5893 syntax_error_unterm_ch('`');
5894 /*xfunc_die(); - redundant */
5899 /* \x. Copy both chars unless it is \` */
5900 int ch2 = i_getch(input);
5902 syntax_error_unterm_ch('`');
5903 /*xfunc_die(); - redundant */
5905 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5912 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5913 * quoting and nested ()s.
5914 * "With the $(command) style of command substitution, all characters
5915 * following the open parenthesis to the matching closing parenthesis
5916 * constitute the command. Any valid shell script can be used for command,
5917 * except a script consisting solely of redirections which produces
5918 * unspecified results."
5920 * echo $(echo '(TEST)' BEST) (TEST) BEST
5921 * echo $(echo 'TEST)' BEST) TEST) BEST
5922 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5924 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
5925 * can contain arbitrary constructs, just like $(cmd).
5926 * In bash compat mode, it needs to also be able to stop on '}' or ':'
5927 * for ${var:N[:M]} parsing.
5929 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
5930 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
5933 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
5934 #if ENABLE_HUSH_BASH_COMPAT
5935 char end_char2 = end_ch >> 8;
5937 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
5940 ch = i_getch(input);
5942 syntax_error_unterm_ch(end_ch);
5943 /*xfunc_die(); - redundant */
5945 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
5948 /* we look for closing )) of $((EXPR)) */
5949 if (i_peek(input) == end_ch) {
5950 i_getch(input); /* eat second ')' */
5955 if (ch == '(' || ch == '{') {
5956 ch = (ch == '(' ? ')' : '}');
5957 add_till_closing_bracket(dest, input, ch);
5962 add_till_single_quote(dest, input);
5967 add_till_double_quote(dest, input);
5972 add_till_backquote(dest, input);
5977 /* \x. Copy verbatim. Important for \(, \) */
5978 ch = i_getch(input);
5980 syntax_error_unterm_ch(')');
5981 /*xfunc_die(); - redundant */
5989 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5991 /* Return code: 0 for OK, 1 for syntax error */
5993 #define parse_dollar(as_string, dest, input) \
5994 parse_dollar(dest, input)
5995 #define as_string NULL
5997 static int parse_dollar(o_string *as_string,
5999 struct in_str *input)
6001 int ch = i_peek(input); /* first character after the $ */
6002 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
6004 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
6006 ch = i_getch(input);
6007 nommu_addchr(as_string, ch);
6009 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6011 debug_printf_parse(": '%c'\n", ch);
6012 o_addchr(dest, ch | quote_mask);
6015 if (!isalnum(ch) && ch != '_')
6017 ch = i_getch(input);
6018 nommu_addchr(as_string, ch);
6020 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6021 } else if (isdigit(ch)) {
6023 ch = i_getch(input);
6024 nommu_addchr(as_string, ch);
6025 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6026 debug_printf_parse(": '%c'\n", ch);
6027 o_addchr(dest, ch | quote_mask);
6028 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6029 } else switch (ch) {
6031 case '!': /* last bg pid */
6032 case '?': /* last exit code */
6033 case '#': /* number of args */
6034 case '*': /* args */
6035 case '@': /* args */
6036 goto make_one_char_var;
6038 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6040 ch = i_getch(input); /* eat '{' */
6041 nommu_addchr(as_string, ch);
6043 ch = i_getch(input); /* first char after '{' */
6044 nommu_addchr(as_string, ch);
6045 /* It should be ${?}, or ${#var},
6046 * or even ${?+subst} - operator acting on a special variable,
6047 * or the beginning of variable name.
6049 if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
6051 syntax_error_unterm_str("${name}");
6052 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
6057 /* It's possible to just call add_till_closing_bracket() at this point.
6058 * However, this regresses some of our testsuite cases
6059 * which check invalid constructs like ${%}.
6060 * Oh well... let's check that the var name part is fine... */
6066 debug_printf_parse(": '%c'\n", ch);
6068 ch = i_getch(input);
6069 nommu_addchr(as_string, ch);
6073 if (!isalnum(ch) && ch != '_') {
6075 unsigned char last_ch;
6076 /* handle parameter expansions
6077 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6079 if (!strchr("%#:-=+?", ch)) /* ${var<bad_char>... */
6080 goto bad_dollar_syntax;
6083 /* Eat everything until closing '}' (or ':') */
6085 if (ENABLE_HUSH_BASH_COMPAT
6087 && !strchr("%#:-=+?"+3, i_peek(input))
6089 /* It's ${var:N[:M]} thing */
6090 end_ch = '}' * 0x100 + ':';
6095 last_ch = add_till_closing_bracket(dest, input, end_ch);
6097 o_addstr(as_string, dest->data + pos);
6098 o_addchr(as_string, last_ch);
6101 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
6102 /* close the first block: */
6103 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6104 /* while parsing N from ${var:N[:M]}... */
6105 if ((end_ch & 0xff) == last_ch) {
6106 /* ...got ':' - parse the rest */
6110 /* ...got '}', not ':' - it's ${var:N}! emulate :999999999 */
6111 o_addstr(dest, "999999999");
6116 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6119 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6123 ch = i_getch(input);
6124 nommu_addchr(as_string, ch);
6125 # if ENABLE_SH_MATH_SUPPORT
6126 if (i_peek(input) == '(') {
6127 ch = i_getch(input);
6128 nommu_addchr(as_string, ch);
6129 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6130 o_addchr(dest, /*quote_mask |*/ '+');
6133 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
6135 o_addstr(as_string, dest->data + pos);
6136 o_addchr(as_string, ')');
6137 o_addchr(as_string, ')');
6139 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6143 # if ENABLE_HUSH_TICK
6144 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6145 o_addchr(dest, quote_mask | '`');
6148 add_till_closing_bracket(dest, input, ')');
6150 o_addstr(as_string, dest->data + pos);
6151 o_addchr(as_string, ')');
6153 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6159 ch = i_getch(input);
6160 nommu_addchr(as_string, ch);
6162 if (isalnum(ch)) { /* it's $_name or $_123 */
6167 /* TODO: $_ and $-: */
6168 /* $_ Shell or shell script name; or last argument of last command
6169 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6170 * but in command's env, set to full pathname used to invoke it */
6171 /* $- Option flags set by set builtin or shell options (-i etc) */
6173 o_addQchr(dest, '$');
6175 debug_printf_parse("parse_dollar return 0\n");
6181 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6182 parse_stream_dquoted(dest, input, dquote_end)
6183 #define as_string NULL
6185 static int parse_stream_dquoted(o_string *as_string,
6187 struct in_str *input,
6194 ch = i_getch(input);
6196 nommu_addchr(as_string, ch);
6197 if (ch == dquote_end) { /* may be only '"' or EOF */
6198 if (dest->o_assignment == NOT_ASSIGNMENT)
6199 dest->o_escape ^= 1;
6200 debug_printf_parse("parse_stream_dquoted return 0\n");
6203 /* note: can't move it above ch == dquote_end check! */
6205 syntax_error_unterm_ch('"');
6206 /*xfunc_die(); - redundant */
6210 next = i_peek(input);
6212 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6213 ch, ch, dest->o_escape);
6216 syntax_error("\\<eof>");
6220 * "The backslash retains its special meaning [in "..."]
6221 * only when followed by one of the following characters:
6222 * $, `, ", \, or <newline>. A double quote may be quoted
6223 * within double quotes by preceding it with a backslash."
6225 if (strchr("$`\"\\\n", next) != NULL) {
6226 ch = i_getch(input);
6228 o_addqchr(dest, ch);
6229 nommu_addchr(as_string, ch);
6232 o_addqchr(dest, '\\');
6233 nommu_addchr(as_string, '\\');
6238 if (parse_dollar(as_string, dest, input) != 0) {
6239 debug_printf_parse("parse_stream_dquoted return 1: "
6240 "parse_dollar returned non-0\n");
6245 #if ENABLE_HUSH_TICK
6247 //unsigned pos = dest->length;
6248 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6249 o_addchr(dest, 0x80 | '`');
6250 add_till_backquote(dest, input);
6251 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6252 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6256 o_addQchr(dest, ch);
6258 && (dest->o_assignment == MAYBE_ASSIGNMENT
6259 || dest->o_assignment == WORD_IS_KEYWORD)
6260 && is_well_formed_var_name(dest->data, '=')
6262 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6269 * Scan input until EOF or end_trigger char.
6270 * Return a list of pipes to execute, or NULL on EOF
6271 * or if end_trigger character is met.
6272 * On syntax error, exit is shell is not interactive,
6273 * reset parsing machinery and start parsing anew,
6274 * or return ERR_PTR.
6276 static struct pipe *parse_stream(char **pstring,
6277 struct in_str *input,
6280 struct parse_context ctx;
6281 o_string dest = NULL_O_STRING;
6285 /* Double-quote state is handled in the state variable is_in_dquote.
6286 * A single-quote triggers a bypass of the main loop until its mate is
6287 * found. When recursing, quote state is passed in via dest->o_escape.
6289 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6290 end_trigger ? end_trigger : 'X');
6293 /* If very first arg is "" or '', dest.data may end up NULL.
6294 * Preventing this: */
6295 o_addchr(&dest, '\0');
6298 G.ifs = get_local_var_value("IFS");
6303 #if ENABLE_HUSH_INTERACTIVE
6304 input->promptmode = 0; /* PS1 */
6306 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6307 initialize_context(&ctx);
6312 const char *is_special;
6316 redir_type redir_style;
6319 /* dest.o_quoted = 1; - already is (see below) */
6320 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6323 /* We reached closing '"' */
6326 ch = i_getch(input);
6327 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6328 ch, ch, dest.o_escape);
6333 syntax_error_unterm_str("here document");
6336 /* end_trigger == '}' case errors out earlier,
6337 * checking only ')' */
6338 if (end_trigger == ')') {
6339 syntax_error_unterm_ch('('); /* exits */
6340 /* goto parse_error; */
6343 if (done_word(&dest, &ctx)) {
6347 done_pipe(&ctx, PIPE_SEQ);
6349 /* If we got nothing... */
6350 /* (this makes bare "&" cmd a no-op.
6351 * bash says: "syntax error near unexpected token '&'") */
6352 if (pi->num_cmds == 0
6353 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6359 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6361 *pstring = ctx.as_string.data;
6363 o_free_unsafe(&ctx.as_string);
6366 debug_printf_parse("parse_stream return %p\n", pi);
6369 nommu_addchr(&ctx.as_string, ch);
6373 next = i_peek(input);
6375 is_special = "{}<>;&|()#'" /* special outside of "str" */
6376 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6377 /* Are { and } special here? */
6378 if (ctx.command->argv /* word [word]{... - non-special */
6379 || dest.length /* word{... - non-special */
6380 || dest.o_quoted /* ""{... - non-special */
6381 || (next != ';' /* }; - special */
6382 && next != ')' /* }) - special */
6383 && next != '&' /* }& and }&& ... - special */
6384 && next != '|' /* }|| ... - special */
6385 && !strchr(G.ifs, next) /* {word - non-special */
6388 /* They are not special, skip "{}" */
6391 is_special = strchr(is_special, ch);
6392 is_ifs = strchr(G.ifs, ch);
6394 if (!is_special && !is_ifs) { /* ordinary char */
6396 o_addQchr(&dest, ch);
6397 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6398 || dest.o_assignment == WORD_IS_KEYWORD)
6400 && is_well_formed_var_name(dest.data, '=')
6402 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6408 if (done_word(&dest, &ctx)) {
6412 #if ENABLE_HUSH_CASE
6413 /* "case ... in <newline> word) ..." -
6414 * newlines are ignored (but ';' wouldn't be) */
6415 if (ctx.command->argv == NULL
6416 && ctx.ctx_res_w == RES_MATCH
6421 /* Treat newline as a command separator. */
6422 done_pipe(&ctx, PIPE_SEQ);
6423 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6425 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6430 dest.o_assignment = MAYBE_ASSIGNMENT;
6432 /* note: if (is_ifs) continue;
6433 * will still trigger for us */
6437 /* "cmd}" or "cmd }..." without semicolon or &:
6438 * } is an ordinary char in this case, even inside { cmd; }
6439 * Pathological example: { ""}; } should exec "}" cmd
6442 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6443 || dest.length != 0 /* word} */
6444 || dest.o_quoted /* ""} */
6448 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6449 goto skip_end_trigger;
6450 /* else: } does terminate a group */
6453 if (end_trigger && end_trigger == ch
6454 && (ch != ';' || heredoc_cnt == 0)
6455 #if ENABLE_HUSH_CASE
6457 || ctx.ctx_res_w != RES_MATCH
6458 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6463 /* This is technically valid:
6464 * { cat <<HERE; }; echo Ok
6468 * but we don't support this.
6469 * We require heredoc to be in enclosing {}/(),
6472 syntax_error_unterm_str("here document");
6475 if (done_word(&dest, &ctx)) {
6478 done_pipe(&ctx, PIPE_SEQ);
6479 dest.o_assignment = MAYBE_ASSIGNMENT;
6480 /* Do we sit outside of any if's, loops or case's? */
6482 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6486 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6488 *pstring = ctx.as_string.data;
6490 o_free_unsafe(&ctx.as_string);
6493 debug_printf_parse("parse_stream return %p: "
6494 "end_trigger char found\n",
6496 return ctx.list_head;
6503 /* Catch <, > before deciding whether this word is
6504 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6507 redir_fd = redirect_opt_num(&dest);
6508 if (done_word(&dest, &ctx)) {
6511 redir_style = REDIRECT_OVERWRITE;
6513 redir_style = REDIRECT_APPEND;
6514 ch = i_getch(input);
6515 nommu_addchr(&ctx.as_string, ch);
6518 else if (next == '(') {
6519 syntax_error(">(process) not supported");
6523 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6525 continue; /* back to top of while (1) */
6527 redir_fd = redirect_opt_num(&dest);
6528 if (done_word(&dest, &ctx)) {
6531 redir_style = REDIRECT_INPUT;
6533 redir_style = REDIRECT_HEREDOC;
6535 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6536 ch = i_getch(input);
6537 nommu_addchr(&ctx.as_string, ch);
6538 } else if (next == '>') {
6539 redir_style = REDIRECT_IO;
6540 ch = i_getch(input);
6541 nommu_addchr(&ctx.as_string, ch);
6544 else if (next == '(') {
6545 syntax_error("<(process) not supported");
6549 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6551 continue; /* back to top of while (1) */
6554 if (dest.o_assignment == MAYBE_ASSIGNMENT
6555 /* check that we are not in word in "a=1 2>word b=1": */
6556 && !ctx.pending_redirect
6558 /* ch is a special char and thus this word
6559 * cannot be an assignment */
6560 dest.o_assignment = NOT_ASSIGNMENT;
6563 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6567 if (dest.length == 0) {
6570 if (ch == EOF || ch == '\n')
6573 /* note: we do not add it to &ctx.as_string */
6575 nommu_addchr(&ctx.as_string, '\n');
6577 o_addQchr(&dest, ch);
6582 syntax_error("\\<eof>");
6585 ch = i_getch(input);
6587 o_addchr(&dest, '\\');
6588 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6589 o_addchr(&dest, ch);
6590 nommu_addchr(&ctx.as_string, ch);
6591 /* Example: echo Hello \2>file
6592 * we need to know that word 2 is quoted */
6597 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6598 ctx.as_string.data[--ctx.as_string.length] = '\0';
6603 if (parse_dollar(&ctx.as_string, &dest, input) != 0) {
6604 debug_printf_parse("parse_stream parse error: "
6605 "parse_dollar returned non-0\n");
6612 ch = i_getch(input);
6614 syntax_error_unterm_ch('\'');
6615 /*xfunc_die(); - redundant */
6617 nommu_addchr(&ctx.as_string, ch);
6620 o_addqchr(&dest, ch);
6625 is_in_dquote ^= 1; /* invert */
6626 if (dest.o_assignment == NOT_ASSIGNMENT)
6629 #if ENABLE_HUSH_TICK
6633 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6634 o_addchr(&dest, '`');
6636 add_till_backquote(&dest, input);
6638 o_addstr(&ctx.as_string, dest.data + pos);
6639 o_addchr(&ctx.as_string, '`');
6641 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6642 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6647 #if ENABLE_HUSH_CASE
6650 if (done_word(&dest, &ctx)) {
6653 done_pipe(&ctx, PIPE_SEQ);
6654 #if ENABLE_HUSH_CASE
6655 /* Eat multiple semicolons, detect
6656 * whether it means something special */
6661 ch = i_getch(input);
6662 nommu_addchr(&ctx.as_string, ch);
6663 if (ctx.ctx_res_w == RES_CASE_BODY) {
6664 ctx.ctx_dsemicolon = 1;
6665 ctx.ctx_res_w = RES_MATCH;
6671 /* We just finished a cmd. New one may start
6672 * with an assignment */
6673 dest.o_assignment = MAYBE_ASSIGNMENT;
6676 if (done_word(&dest, &ctx)) {
6680 ch = i_getch(input);
6681 nommu_addchr(&ctx.as_string, ch);
6682 done_pipe(&ctx, PIPE_AND);
6684 done_pipe(&ctx, PIPE_BG);
6688 if (done_word(&dest, &ctx)) {
6691 #if ENABLE_HUSH_CASE
6692 if (ctx.ctx_res_w == RES_MATCH)
6693 break; /* we are in case's "word | word)" */
6695 if (next == '|') { /* || */
6696 ch = i_getch(input);
6697 nommu_addchr(&ctx.as_string, ch);
6698 done_pipe(&ctx, PIPE_OR);
6700 /* we could pick up a file descriptor choice here
6701 * with redirect_opt_num(), but bash doesn't do it.
6702 * "echo foo 2| cat" yields "foo 2". */
6705 o_reset_to_empty_unquoted(&ctx.as_string);
6710 #if ENABLE_HUSH_CASE
6711 /* "case... in [(]word)..." - skip '(' */
6712 if (ctx.ctx_res_w == RES_MATCH
6713 && ctx.command->argv == NULL /* not (word|(... */
6714 && dest.length == 0 /* not word(... */
6715 && dest.o_quoted == 0 /* not ""(... */
6721 if (parse_group(&dest, &ctx, input, ch) != 0) {
6726 #if ENABLE_HUSH_CASE
6727 if (ctx.ctx_res_w == RES_MATCH)
6731 /* proper use of this character is caught by end_trigger:
6732 * if we see {, we call parse_group(..., end_trigger='}')
6733 * and it will match } earlier (not here). */
6734 syntax_error_unexpected_ch(ch);
6738 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6744 struct parse_context *pctx;
6745 IF_HAS_KEYWORDS(struct parse_context *p2;)
6747 /* Clean up allocated tree.
6748 * Sample for finding leaks on syntax error recovery path.
6749 * Run it from interactive shell, watch pmap `pidof hush`.
6750 * while if false; then false; fi; do break; fi
6751 * Samples to catch leaks at execution:
6752 * while if (true | {true;}); then echo ok; fi; do break; done
6753 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6757 /* Update pipe/command counts,
6758 * otherwise freeing may miss some */
6759 done_pipe(pctx, PIPE_SEQ);
6760 debug_printf_clean("freeing list %p from ctx %p\n",
6761 pctx->list_head, pctx);
6762 debug_print_tree(pctx->list_head, 0);
6763 free_pipe_list(pctx->list_head);
6764 debug_printf_clean("freed list %p\n", pctx->list_head);
6766 o_free_unsafe(&pctx->as_string);
6768 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6772 IF_HAS_KEYWORDS(pctx = p2;)
6773 } while (HAS_KEYWORDS && pctx);
6774 /* Free text, clear all dest fields */
6776 /* If we are not in top-level parse, we return,
6777 * our caller will propagate error.
6779 if (end_trigger != ';') {
6787 /* Discard cached input, force prompt */
6789 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6794 /* Executing from string: eval, sh -c '...'
6795 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6796 * end_trigger controls how often we stop parsing
6797 * NUL: parse all, execute, return
6798 * ';': parse till ';' or newline, execute, repeat till EOF
6800 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6802 /* Why we need empty flag?
6803 * An obscure corner case "false; ``; echo $?":
6804 * empty command in `` should still set $? to 0.
6805 * But we can't just set $? to 0 at the start,
6806 * this breaks "false; echo `echo $?`" case.
6810 struct pipe *pipe_list;
6812 pipe_list = parse_stream(NULL, inp, end_trigger);
6813 if (!pipe_list) { /* EOF */
6815 G.last_exitcode = 0;
6818 debug_print_tree(pipe_list, 0);
6819 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6820 run_and_free_list(pipe_list);
6825 static void parse_and_run_string(const char *s)
6827 struct in_str input;
6828 setup_string_in_str(&input, s);
6829 parse_and_run_stream(&input, '\0');
6832 static void parse_and_run_file(FILE *f)
6834 struct in_str input;
6835 setup_file_in_str(&input, f);
6836 parse_and_run_stream(&input, ';');
6839 /* Called a few times only (or even once if "sh -c") */
6840 static void init_sigmasks(void)
6844 sigset_t old_blocked_set;
6846 if (!G.inherited_set_is_saved) {
6847 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6848 G.inherited_set = G.blocked_set;
6850 old_blocked_set = G.blocked_set;
6852 mask = (1 << SIGQUIT);
6853 if (G_interactive_fd) {
6854 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6855 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6856 mask |= SPECIAL_JOB_SIGS;
6858 G.non_DFL_mask = mask;
6863 sigaddset(&G.blocked_set, sig);
6867 sigdelset(&G.blocked_set, SIGCHLD);
6869 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6870 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6872 /* POSIX allows shell to re-enable SIGCHLD
6873 * even if it was SIG_IGN on entry */
6874 #if ENABLE_HUSH_FAST
6875 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6876 if (!G.inherited_set_is_saved)
6877 signal(SIGCHLD, SIGCHLD_handler);
6879 if (!G.inherited_set_is_saved)
6880 signal(SIGCHLD, SIG_DFL);
6883 G.inherited_set_is_saved = 1;
6888 static void maybe_set_to_sigexit(int sig)
6890 void (*handler)(int);
6891 /* non_DFL_mask'ed signals are, well, masked,
6892 * no need to set handler for them.
6894 if (!((G.non_DFL_mask >> sig) & 1)) {
6895 handler = signal(sig, sigexit);
6896 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6897 signal(sig, handler);
6900 /* Set handlers to restore tty pgrp and exit */
6901 static void set_fatal_handlers(void)
6903 /* We _must_ restore tty pgrp on fatal signals */
6905 maybe_set_to_sigexit(SIGILL );
6906 maybe_set_to_sigexit(SIGFPE );
6907 maybe_set_to_sigexit(SIGBUS );
6908 maybe_set_to_sigexit(SIGSEGV);
6909 maybe_set_to_sigexit(SIGTRAP);
6910 } /* else: hush is perfect. what SEGV? */
6911 maybe_set_to_sigexit(SIGABRT);
6912 /* bash 3.2 seems to handle these just like 'fatal' ones */
6913 maybe_set_to_sigexit(SIGPIPE);
6914 maybe_set_to_sigexit(SIGALRM);
6915 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6916 * if we aren't interactive... but in this case
6917 * we never want to restore pgrp on exit, and this fn is not called */
6918 /*maybe_set_to_sigexit(SIGHUP );*/
6919 /*maybe_set_to_sigexit(SIGTERM);*/
6920 /*maybe_set_to_sigexit(SIGINT );*/
6924 static int set_mode(const char cstate, const char mode)
6926 int state = (cstate == '-' ? 1 : 0);
6928 case 'n': G.fake_mode = state; break;
6929 case 'x': /*G.debug_mode = state;*/ break;
6930 default: return EXIT_FAILURE;
6932 return EXIT_SUCCESS;
6935 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6936 int hush_main(int argc, char **argv)
6938 static const struct variable const_shell_ver = {
6940 .varstr = (char*)hush_version_str,
6941 .max_len = 1, /* 0 can provoke free(name) */
6946 unsigned builtin_argc;
6948 struct variable *cur_var;
6951 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6952 G.last_exitcode = EXIT_SUCCESS;
6954 G.argv0_for_re_execing = argv[0];
6956 /* Deal with HUSH_VERSION */
6957 G.shell_ver = const_shell_ver; /* copying struct here */
6958 G.top_var = &G.shell_ver;
6959 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6960 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6961 /* Initialize our shell local variables with the values
6962 * currently living in the environment */
6963 cur_var = G.top_var;
6966 char *value = strchr(*e, '=');
6967 if (value) { /* paranoia */
6968 cur_var->next = xzalloc(sizeof(*cur_var));
6969 cur_var = cur_var->next;
6970 cur_var->varstr = *e;
6971 cur_var->max_len = strlen(*e);
6972 cur_var->flg_export = 1;
6976 /* reinstate HUSH_VERSION */
6977 debug_printf_env("putenv '%s'\n", hush_version_str);
6978 putenv((char *)hush_version_str);
6981 set_pwd_var(/*exp:*/ 1);
6982 /* bash also exports SHLVL and _,
6983 * and sets (but doesn't export) the following variables:
6985 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6986 * BASH_VERSION='3.2.0(1)-release'
6988 * MACHTYPE=i386-pc-linux-gnu
6990 * HOSTNAME=<xxxxxxxxxx>
6991 * PPID=<NNNNN> - we also do it elsewhere
7002 * PIPESTATUS=([0]="0")
7003 * HISTFILE=/<xxx>/.bash_history
7007 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7009 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7019 #if ENABLE_FEATURE_EDITING
7020 G.line_input_state = new_line_input_t(FOR_SHELL);
7022 G.global_argc = argc;
7023 G.global_argv = argv;
7024 /* Initialize some more globals to non-zero values */
7025 cmdedit_update_prompt();
7027 if (setjmp(die_jmp)) {
7028 /* xfunc has failed! die die die */
7029 /* no EXIT traps, this is an escape hatch! */
7031 hush_exit(xfunc_error_retval);
7034 /* Shell is non-interactive at first. We need to call
7035 * init_sigmasks() if we are going to execute "sh <script>",
7036 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7037 * If we later decide that we are interactive, we run init_sigmasks()
7038 * in order to intercept (more) signals.
7042 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7045 opt = getopt(argc, argv, "+c:xins"
7048 # if ENABLE_HUSH_FUNCTIONS
7058 * sh ... -c 'script'
7059 * sh ... -c 'script' ARG0 [ARG1...]
7060 * On NOMMU, if builtin_argc != 0,
7061 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7062 * "" needs to be replaced with NULL
7063 * and BARGV vector fed to builtin function.
7064 * Note: the form without ARG0 never happens:
7065 * sh ... -c 'builtin' BARGV... ""
7068 G.root_pid = getpid();
7069 G.root_ppid = getppid();
7071 G.global_argv = argv + optind;
7072 G.global_argc = argc - optind;
7074 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7075 const struct built_in_command *x;
7078 x = find_builtin(optarg);
7079 if (x) { /* paranoia */
7080 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7081 G.global_argv += builtin_argc;
7082 G.global_argv[-1] = NULL; /* replace "" */
7083 G.last_exitcode = x->b_function(argv + optind - 1);
7087 if (!G.global_argv[0]) {
7088 /* -c 'script' (no params): prevent empty $0 */
7089 G.global_argv--; /* points to argv[i] of 'script' */
7090 G.global_argv[0] = argv[0];
7092 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7094 parse_and_run_string(optarg);
7097 /* Well, we cannot just declare interactiveness,
7098 * we have to have some stuff (ctty, etc) */
7099 /* G_interactive_fd++; */
7102 /* "-s" means "read from stdin", but this is how we always
7103 * operate, so simply do nothing here. */
7106 case '<': /* "big heredoc" support */
7107 full_write(STDOUT_FILENO, optarg, strlen(optarg));
7110 unsigned long long empty_trap_mask;
7112 G.root_pid = bb_strtou(optarg, &optarg, 16);
7114 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7116 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7118 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7120 builtin_argc = bb_strtou(optarg, &optarg, 16);
7122 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7123 if (empty_trap_mask != 0) {
7126 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7127 for (sig = 1; sig < NSIG; sig++) {
7128 if (empty_trap_mask & (1LL << sig)) {
7129 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7130 sigaddset(&G.blocked_set, sig);
7133 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7135 # if ENABLE_HUSH_LOOPS
7137 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7143 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7145 # if ENABLE_HUSH_FUNCTIONS
7147 struct function *funcp = new_function(optarg);
7148 /* funcp->name is already set to optarg */
7149 /* funcp->body is set to NULL. It's a special case. */
7150 funcp->body_as_string = argv[optind];
7158 if (!set_mode('-', opt))
7162 fprintf(stderr, "Usage: sh [FILE]...\n"
7163 " or: sh -c command [args]...\n\n");
7169 } /* option parsing loop */
7172 G.root_pid = getpid();
7173 G.root_ppid = getppid();
7176 /* If we are login shell... */
7177 if (argv[0] && argv[0][0] == '-') {
7179 debug_printf("sourcing /etc/profile\n");
7180 input = fopen_for_read("/etc/profile");
7181 if (input != NULL) {
7182 close_on_exec_on(fileno(input));
7184 parse_and_run_file(input);
7187 /* bash: after sourcing /etc/profile,
7188 * tries to source (in the given order):
7189 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7190 * stopping on first found. --noprofile turns this off.
7191 * bash also sources ~/.bash_logout on exit.
7192 * If called as sh, skips .bash_XXX files.
7199 * "bash <script>" (which is never interactive (unless -i?))
7200 * sources $BASH_ENV here (without scanning $PATH).
7201 * If called as sh, does the same but with $ENV.
7203 debug_printf("running script '%s'\n", argv[optind]);
7204 G.global_argv = argv + optind;
7205 G.global_argc = argc - optind;
7206 input = xfopen_for_read(argv[optind]);
7207 close_on_exec_on(fileno(input));
7209 parse_and_run_file(input);
7210 #if ENABLE_FEATURE_CLEAN_UP
7216 /* Up to here, shell was non-interactive. Now it may become one.
7217 * NB: don't forget to (re)run init_sigmasks() as needed.
7220 /* A shell is interactive if the '-i' flag was given,
7221 * or if all of the following conditions are met:
7223 * no arguments remaining or the -s flag given
7224 * standard input is a terminal
7225 * standard output is a terminal
7226 * Refer to Posix.2, the description of the 'sh' utility.
7229 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7230 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7231 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7232 if (G_saved_tty_pgrp < 0)
7233 G_saved_tty_pgrp = 0;
7235 /* try to dup stdin to high fd#, >= 255 */
7236 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7237 if (G_interactive_fd < 0) {
7238 /* try to dup to any fd */
7239 G_interactive_fd = dup(STDIN_FILENO);
7240 if (G_interactive_fd < 0) {
7242 G_interactive_fd = 0;
7243 G_saved_tty_pgrp = 0;
7246 // TODO: track & disallow any attempts of user
7247 // to (inadvertently) close/redirect G_interactive_fd
7249 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7250 if (G_interactive_fd) {
7251 close_on_exec_on(G_interactive_fd);
7253 if (G_saved_tty_pgrp) {
7254 /* If we were run as 'hush &', sleep until we are
7255 * in the foreground (tty pgrp == our pgrp).
7256 * If we get started under a job aware app (like bash),
7257 * make sure we are now in charge so we don't fight over
7258 * who gets the foreground */
7260 pid_t shell_pgrp = getpgrp();
7261 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7262 if (G_saved_tty_pgrp == shell_pgrp)
7264 /* send TTIN to ourself (should stop us) */
7265 kill(- shell_pgrp, SIGTTIN);
7269 /* Block some signals */
7272 if (G_saved_tty_pgrp) {
7273 /* Set other signals to restore saved_tty_pgrp */
7274 set_fatal_handlers();
7275 /* Put ourselves in our own process group
7276 * (bash, too, does this only if ctty is available) */
7277 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7278 /* Grab control of the terminal */
7279 tcsetpgrp(G_interactive_fd, getpid());
7281 /* -1 is special - makes xfuncs longjmp, not exit
7282 * (we reset die_sleep = 0 whereever we [v]fork) */
7283 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7287 #elif ENABLE_HUSH_INTERACTIVE
7288 /* No job control compiled in, only prompt/line editing */
7289 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7290 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7291 if (G_interactive_fd < 0) {
7292 /* try to dup to any fd */
7293 G_interactive_fd = dup(STDIN_FILENO);
7294 if (G_interactive_fd < 0)
7296 G_interactive_fd = 0;
7299 if (G_interactive_fd) {
7300 close_on_exec_on(G_interactive_fd);
7304 /* We have interactiveness code disabled */
7308 * if interactive but not a login shell, sources ~/.bashrc
7309 * (--norc turns this off, --rcfile <file> overrides)
7312 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7313 /* note: ash and hush share this string */
7314 printf("\n\n%s %s\n"
7315 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7318 "hush - the humble shell"
7322 parse_and_run_file(stdin);
7325 #if ENABLE_FEATURE_CLEAN_UP
7326 if (G.cwd != bb_msg_unknown)
7328 cur_var = G.top_var->next;
7330 struct variable *tmp = cur_var;
7331 if (!cur_var->max_len)
7332 free(cur_var->varstr);
7333 cur_var = cur_var->next;
7337 hush_exit(G.last_exitcode);
7342 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7343 int lash_main(int argc, char **argv)
7345 bb_error_msg("lash is deprecated, please use hush instead");
7346 return hush_main(argc, argv);
7351 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7352 int msh_main(int argc, char **argv)
7354 //bb_error_msg("msh is deprecated, please use hush instead");
7355 return hush_main(argc, argv);
7363 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7368 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7375 return applet_main_func(argc, argv - argc);
7378 static int FAST_FUNC builtin_test(char **argv)
7380 return run_applet_main(argv, test_main);
7383 static int FAST_FUNC builtin_echo(char **argv)
7385 return run_applet_main(argv, echo_main);
7389 static int FAST_FUNC builtin_printf(char **argv)
7391 return run_applet_main(argv, printf_main);
7395 static char **skip_dash_dash(char **argv)
7398 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7403 static int FAST_FUNC builtin_eval(char **argv)
7405 int rcode = EXIT_SUCCESS;
7407 argv = skip_dash_dash(argv);
7409 char *str = expand_strvec_to_string(argv);
7411 * eval "echo Hi; done" ("done" is syntax error):
7412 * "echo Hi" will not execute too.
7414 parse_and_run_string(str);
7416 rcode = G.last_exitcode;
7421 static int FAST_FUNC builtin_cd(char **argv)
7425 argv = skip_dash_dash(argv);
7427 if (newdir == NULL) {
7428 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7429 * bash says "bash: cd: HOME not set" and does nothing
7432 const char *home = get_local_var_value("HOME");
7433 newdir = home ? home : "/";
7435 if (chdir(newdir)) {
7436 /* Mimic bash message exactly */
7437 bb_perror_msg("cd: %s", newdir);
7438 return EXIT_FAILURE;
7440 /* Read current dir (get_cwd(1) is inside) and set PWD.
7441 * Note: do not enforce exporting. If PWD was unset or unexported,
7442 * set it again, but do not export. bash does the same.
7444 set_pwd_var(/*exp:*/ 0);
7445 return EXIT_SUCCESS;
7448 static int FAST_FUNC builtin_exec(char **argv)
7450 argv = skip_dash_dash(argv);
7451 if (argv[0] == NULL)
7452 return EXIT_SUCCESS; /* bash does this */
7454 /* Careful: we can end up here after [v]fork. Do not restore
7455 * tty pgrp then, only top-level shell process does that */
7456 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7457 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7459 /* TODO: if exec fails, bash does NOT exit! We do.
7460 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7461 * and tcsetpgrp, and this is inherently racy.
7463 execvp_or_die(argv);
7466 static int FAST_FUNC builtin_exit(char **argv)
7468 debug_printf_exec("%s()\n", __func__);
7470 /* interactive bash:
7471 * # trap "echo EEE" EXIT
7474 * There are stopped jobs.
7475 * (if there are _stopped_ jobs, running ones don't count)
7478 # EEE (then bash exits)
7480 * we can use G.exiting = -1 as indicator "last cmd was exit"
7483 /* note: EXIT trap is run by hush_exit */
7484 argv = skip_dash_dash(argv);
7485 if (argv[0] == NULL)
7486 hush_exit(G.last_exitcode);
7487 /* mimic bash: exit 123abc == exit 255 + error msg */
7488 xfunc_error_retval = 255;
7489 /* bash: exit -2 == exit 254, no error msg */
7490 hush_exit(xatoi(argv[0]) & 0xff);
7493 static void print_escaped(const char *s)
7498 const char *p = strchrnul(s, '\'');
7499 /* print 'xxxx', possibly just '' */
7500 printf("'%.*s'", (int)(p - s), s);
7505 /* s points to '; print "'''...'''" */
7507 do putchar('\''); while (*++s == '\'');
7512 #if !ENABLE_HUSH_LOCAL
7513 #define helper_export_local(argv, exp, lvl) \
7514 helper_export_local(argv, exp)
7516 static void helper_export_local(char **argv, int exp, int lvl)
7521 /* So far we do not check that name is valid (TODO?) */
7523 if (strchr(name, '=') == NULL) {
7524 struct variable *var;
7526 var = get_local_var(name);
7527 if (exp == -1) { /* unexporting? */
7528 /* export -n NAME (without =VALUE) */
7530 var->flg_export = 0;
7531 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7533 } /* else: export -n NOT_EXISTING_VAR: no-op */
7536 if (exp == 1) { /* exporting? */
7537 /* export NAME (without =VALUE) */
7539 var->flg_export = 1;
7540 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7541 putenv(var->varstr);
7545 /* Exporting non-existing variable.
7546 * bash does not put it in environment,
7547 * but remembers that it is exported,
7548 * and does put it in env when it is set later.
7549 * We just set it to "" and export. */
7550 /* Or, it's "local NAME" (without =VALUE).
7551 * bash sets the value to "". */
7552 name = xasprintf("%s=", name);
7554 /* (Un)exporting/making local NAME=VALUE */
7555 name = xstrdup(name);
7557 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7561 static int FAST_FUNC builtin_export(char **argv)
7563 unsigned opt_unexport;
7565 #if ENABLE_HUSH_EXPORT_N
7566 /* "!": do not abort on errors */
7567 opt_unexport = getopt32(argv, "!n");
7568 if (opt_unexport == (uint32_t)-1)
7569 return EXIT_FAILURE;
7576 if (argv[0] == NULL) {
7583 /* ash emits: export VAR='VAL'
7584 * bash: declare -x VAR="VAL"
7585 * we follow ash example */
7586 const char *s = *e++;
7587 const char *p = strchr(s, '=');
7589 if (!p) /* wtf? take next variable */
7592 printf("export %.*s", (int)(p - s) + 1, s);
7593 print_escaped(p + 1);
7597 /*fflush_all(); - done after each builtin anyway */
7599 return EXIT_SUCCESS;
7602 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7604 return EXIT_SUCCESS;
7607 #if ENABLE_HUSH_LOCAL
7608 static int FAST_FUNC builtin_local(char **argv)
7610 if (G.func_nest_level == 0) {
7611 bb_error_msg("%s: not in a function", argv[0]);
7612 return EXIT_FAILURE; /* bash compat */
7614 helper_export_local(argv, 0, G.func_nest_level);
7615 return EXIT_SUCCESS;
7619 static int FAST_FUNC builtin_trap(char **argv)
7625 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7630 /* No args: print all trapped */
7631 for (i = 0; i < NSIG; ++i) {
7634 print_escaped(G.traps[i]);
7635 /* note: bash adds "SIG", but only if invoked
7636 * as "bash". If called as "sh", or if set -o posix,
7637 * then it prints short signal names.
7638 * We are printing short names: */
7639 printf(" %s\n", get_signame(i));
7642 /*fflush_all(); - done after each builtin anyway */
7643 return EXIT_SUCCESS;
7647 /* If first arg is a number: reset all specified signals */
7648 sig = bb_strtou(*argv, NULL, 10);
7654 sig = get_signum(*argv++);
7655 if (sig < 0 || sig >= NSIG) {
7657 /* Mimic bash message exactly */
7658 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7663 G.traps[sig] = xstrdup(new_cmd);
7665 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7666 get_signame(sig), sig, G.traps[sig]);
7668 /* There is no signal for 0 (EXIT) */
7673 sigaddset(&G.blocked_set, sig);
7675 /* There was a trap handler, we are removing it
7676 * (if sig has non-DFL handling,
7677 * we don't need to do anything) */
7678 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7680 sigdelset(&G.blocked_set, sig);
7683 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7687 if (!argv[1]) { /* no second arg */
7688 bb_error_msg("trap: invalid arguments");
7689 return EXIT_FAILURE;
7692 /* First arg is "-": reset all specified to default */
7693 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7694 /* Everything else: set arg as signal handler
7695 * (includes "" case, which ignores signal) */
7696 if (argv[0][0] == '-') {
7697 if (argv[0][1] == '\0') { /* "-" */
7698 /* new_cmd remains NULL: "reset these sigs" */
7701 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7704 /* else: "-something", no special meaning */
7709 goto process_sig_list;
7712 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7713 static int FAST_FUNC builtin_type(char **argv)
7715 int ret = EXIT_SUCCESS;
7721 if (0) {} /* make conditional compile easier below */
7722 /*else if (find_alias(*argv))
7723 type = "an alias";*/
7724 #if ENABLE_HUSH_FUNCTIONS
7725 else if (find_function(*argv))
7726 type = "a function";
7728 else if (find_builtin(*argv))
7729 type = "a shell builtin";
7730 else if ((path = find_in_path(*argv)) != NULL)
7733 bb_error_msg("type: %s: not found", *argv);
7738 printf("%s is %s\n", *argv, type);
7746 /* built-in 'fg' and 'bg' handler */
7747 static int FAST_FUNC builtin_fg_bg(char **argv)
7752 if (!G_interactive_fd)
7753 return EXIT_FAILURE;
7755 /* If they gave us no args, assume they want the last backgrounded task */
7757 for (pi = G.job_list; pi; pi = pi->next) {
7758 if (pi->jobid == G.last_jobid) {
7762 bb_error_msg("%s: no current job", argv[0]);
7763 return EXIT_FAILURE;
7765 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7766 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7767 return EXIT_FAILURE;
7769 for (pi = G.job_list; pi; pi = pi->next) {
7770 if (pi->jobid == jobnum) {
7774 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7775 return EXIT_FAILURE;
7777 /* TODO: bash prints a string representation
7778 * of job being foregrounded (like "sleep 1 | cat") */
7779 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7780 /* Put the job into the foreground. */
7781 tcsetpgrp(G_interactive_fd, pi->pgrp);
7784 /* Restart the processes in the job */
7785 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7786 for (i = 0; i < pi->num_cmds; i++) {
7787 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7788 pi->cmds[i].is_stopped = 0;
7790 pi->stopped_cmds = 0;
7792 i = kill(- pi->pgrp, SIGCONT);
7794 if (errno == ESRCH) {
7795 delete_finished_bg_job(pi);
7796 return EXIT_SUCCESS;
7798 bb_perror_msg("kill (SIGCONT)");
7801 if (argv[0][0] == 'f') {
7803 return checkjobs_and_fg_shell(pi);
7805 return EXIT_SUCCESS;
7809 #if ENABLE_HUSH_HELP
7810 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7812 const struct built_in_command *x;
7815 "Built-in commands:\n"
7816 "------------------\n");
7817 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7819 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7822 return EXIT_SUCCESS;
7827 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7830 const char *status_string;
7832 for (job = G.job_list; job; job = job->next) {
7833 if (job->alive_cmds == job->stopped_cmds)
7834 status_string = "Stopped";
7836 status_string = "Running";
7838 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7840 return EXIT_SUCCESS;
7845 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7850 # ifdef M_TRIM_THRESHOLD
7851 /* Optional. Reduces probability of false positives */
7854 /* Crude attempt to find where "free memory" starts,
7855 * sans fragmentation. */
7857 l = (unsigned long)p;
7860 if (l < (unsigned long)p) l = (unsigned long)p;
7863 if (!G.memleak_value)
7864 G.memleak_value = l;
7866 l -= G.memleak_value;
7873 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7878 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7881 return EXIT_SUCCESS;
7884 static int FAST_FUNC builtin_read(char **argv)
7893 /* "!": do not abort on errors.
7894 * Option string must start with "sr" to match BUILTIN_READ_xxx
7896 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7897 if (read_flags == (uint32_t)-1)
7898 return EXIT_FAILURE;
7901 r = shell_builtin_read(set_local_var_from_halves,
7903 get_local_var_value("IFS"), /* can be NULL */
7911 if ((uintptr_t)r > 1) {
7912 bb_error_msg("%s", r);
7913 r = (char*)(uintptr_t)1;
7916 return (uintptr_t)r;
7919 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7920 * built-in 'set' handler
7922 * set [-abCefhmnuvx] [-o option] [argument...]
7923 * set [+abCefhmnuvx] [+o option] [argument...]
7924 * set -- [argument...]
7927 * Implementations shall support the options in both their hyphen and
7928 * plus-sign forms. These options can also be specified as options to sh.
7930 * Write out all variables and their values: set
7931 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7932 * Turn on the -x and -v options: set -xv
7933 * Unset all positional parameters: set --
7934 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7935 * Set the positional parameters to the expansion of x, even if x expands
7936 * with a leading '-' or '+': set -- $x
7938 * So far, we only support "set -- [argument...]" and some of the short names.
7940 static int FAST_FUNC builtin_set(char **argv)
7943 char **pp, **g_argv;
7944 char *arg = *++argv;
7948 for (e = G.top_var; e; e = e->next)
7950 return EXIT_SUCCESS;
7954 if (!strcmp(arg, "--")) {
7958 if (arg[0] != '+' && arg[0] != '-')
7960 for (n = 1; arg[n]; ++n)
7961 if (set_mode(arg[0], arg[n]))
7963 } while ((arg = *++argv) != NULL);
7964 /* Now argv[0] is 1st argument */
7967 return EXIT_SUCCESS;
7970 /* NB: G.global_argv[0] ($0) is never freed/changed */
7971 g_argv = G.global_argv;
7972 if (G.global_args_malloced) {
7978 G.global_args_malloced = 1;
7979 pp = xzalloc(sizeof(pp[0]) * 2);
7980 pp[0] = g_argv[0]; /* retain $0 */
7983 /* This realloc's G.global_argv */
7984 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7991 return EXIT_SUCCESS;
7993 /* Nothing known, so abort */
7995 bb_error_msg("set: %s: invalid option", arg);
7996 return EXIT_FAILURE;
7999 static int FAST_FUNC builtin_shift(char **argv)
8002 argv = skip_dash_dash(argv);
8006 if (n >= 0 && n < G.global_argc) {
8007 if (G.global_args_malloced) {
8010 free(G.global_argv[m++]);
8013 memmove(&G.global_argv[1], &G.global_argv[n+1],
8014 G.global_argc * sizeof(G.global_argv[0]));
8015 return EXIT_SUCCESS;
8017 return EXIT_FAILURE;
8020 static int FAST_FUNC builtin_source(char **argv)
8022 char *arg_path, *filename;
8025 #if ENABLE_HUSH_FUNCTIONS
8029 argv = skip_dash_dash(argv);
8032 /* bash says: "bash: .: filename argument required" */
8033 return 2; /* bash compat */
8036 if (!strchr(filename, '/')) {
8037 arg_path = find_in_path(filename);
8039 filename = arg_path;
8041 input = fopen_or_warn(filename, "r");
8044 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8045 return EXIT_FAILURE;
8047 close_on_exec_on(fileno(input));
8049 #if ENABLE_HUSH_FUNCTIONS
8050 sv_flg = G.flag_return_in_progress;
8051 /* "we are inside sourced file, ok to use return" */
8052 G.flag_return_in_progress = -1;
8054 save_and_replace_G_args(&sv, argv);
8056 parse_and_run_file(input);
8059 restore_G_args(&sv, argv);
8060 #if ENABLE_HUSH_FUNCTIONS
8061 G.flag_return_in_progress = sv_flg;
8064 return G.last_exitcode;
8067 static int FAST_FUNC builtin_umask(char **argv)
8073 argv = skip_dash_dash(argv);
8075 mode_t old_mask = mask;
8078 rc = bb_parse_mode(argv[0], &mask);
8083 * bash: umask: 'q': invalid symbolic mode operator
8084 * bash: umask: 999: octal number out of range
8086 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8091 printf("%04o\n", (unsigned) mask);
8092 /* fall through and restore mask which we set to 0 */
8096 return !rc; /* rc != 0 - success */
8099 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8100 static int FAST_FUNC builtin_unset(char **argv)
8105 /* "!": do not abort on errors */
8106 /* "+": stop at 1st non-option */
8107 opts = getopt32(argv, "!+vf");
8108 if (opts == (unsigned)-1)
8109 return EXIT_FAILURE;
8111 bb_error_msg("unset: -v and -f are exclusive");
8112 return EXIT_FAILURE;
8118 if (!(opts & 2)) { /* not -f */
8119 if (unset_local_var(*argv)) {
8120 /* unset <nonexistent_var> doesn't fail.
8121 * Error is when one tries to unset RO var.
8122 * Message was printed by unset_local_var. */
8126 #if ENABLE_HUSH_FUNCTIONS
8136 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8137 static int FAST_FUNC builtin_wait(char **argv)
8139 int ret = EXIT_SUCCESS;
8142 argv = skip_dash_dash(argv);
8143 if (argv[0] == NULL) {
8144 /* Don't care about wait results */
8145 /* Note 1: must wait until there are no more children */
8146 /* Note 2: must be interruptible */
8148 * $ sleep 3 & sleep 6 & wait
8153 * $ sleep 3 & sleep 6 & wait
8157 * ^C <-- after ~4 sec from keyboard
8160 sigaddset(&G.blocked_set, SIGCHLD);
8161 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8164 if (errno == ECHILD)
8166 /* Wait for SIGCHLD or any other signal of interest */
8167 /* sigtimedwait with infinite timeout: */
8168 sig = sigwaitinfo(&G.blocked_set, NULL);
8170 sig = check_and_run_traps(sig);
8171 if (sig && sig != SIGCHLD) { /* see note 2 */
8177 sigdelset(&G.blocked_set, SIGCHLD);
8178 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8182 /* This is probably buggy wrt interruptible-ness */
8184 pid_t pid = bb_strtou(*argv, NULL, 10);
8186 /* mimic bash message */
8187 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8188 return EXIT_FAILURE;
8190 if (waitpid(pid, &status, 0) == pid) {
8191 if (WIFSIGNALED(status))
8192 ret = 128 + WTERMSIG(status);
8193 else if (WIFEXITED(status))
8194 ret = WEXITSTATUS(status);
8198 bb_perror_msg("wait %s", *argv);
8207 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8208 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8211 def = bb_strtou(argv[1], NULL, 10);
8212 if (errno || def < def_min || argv[2]) {
8213 bb_error_msg("%s: bad arguments", argv[0]);
8221 #if ENABLE_HUSH_LOOPS
8222 static int FAST_FUNC builtin_break(char **argv)
8225 if (G.depth_of_loop == 0) {
8226 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8227 return EXIT_SUCCESS; /* bash compat */
8229 G.flag_break_continue++; /* BC_BREAK = 1 */
8231 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8232 if (depth == UINT_MAX)
8233 G.flag_break_continue = BC_BREAK;
8234 if (G.depth_of_loop < depth)
8235 G.depth_break_continue = G.depth_of_loop;
8237 return EXIT_SUCCESS;
8240 static int FAST_FUNC builtin_continue(char **argv)
8242 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8243 return builtin_break(argv);
8247 #if ENABLE_HUSH_FUNCTIONS
8248 static int FAST_FUNC builtin_return(char **argv)
8252 if (G.flag_return_in_progress != -1) {
8253 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8254 return EXIT_FAILURE; /* bash compat */
8257 G.flag_return_in_progress = 1;
8260 * out of range: wraps around at 256, does not error out
8261 * non-numeric param:
8262 * f() { false; return qwe; }; f; echo $?
8263 * bash: return: qwe: numeric argument required <== we do this
8264 * 255 <== we also do this
8266 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);