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 * brace expansion: one/{two,three,four}
54 * reserved words: function select
55 * advanced test: [[ ]]
56 * process substitution: <(list) and >(list)
59 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
60 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
61 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
63 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
64 * This is exactly equivalent to let "EXPR".
65 * $[EXPR]: synonym for $((EXPR))
66 * export builtin should be special, its arguments are assignments
67 * and therefore expansion of them should be "one-word" expansion:
68 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
70 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
71 * ls: cannot access i=a: No such file or directory
72 * ls: cannot access b: No such file or directory
73 * Note1: same applies to local builtin.
74 * Note2: bash 3.2.33(1) does this only if export word itself
76 * $ export i=`echo 'aaa bbb'`; echo "$i"
78 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
81 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
83 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
84 #include <malloc.h> /* for malloc_trim */
86 /* #include <dmalloc.h> */
91 #include "shell_common.h"
92 #include "builtin_read.h"
93 #include "builtin_ulimit.h"
96 #if ENABLE_HUSH_RANDOM_SUPPORT
99 # define CLEAR_RANDOM_T(rnd) ((void)0)
102 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
107 #define LEAK_HUNTING 0
108 #define BUILD_AS_NOMMU 0
109 /* Enable/disable sanity checks. Ok to enable in production,
110 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
111 * Keeping 1 for now even in released versions.
114 /* Slightly bigger (+200 bytes), but faster hush.
115 * So far it only enables a trick with counting SIGCHLDs and forks,
116 * which allows us to do fewer waitpid's.
117 * (we can detect a case where neither forks were done nor SIGCHLDs happened
118 * and therefore waitpid will return the same result as last time)
120 #define ENABLE_HUSH_FAST 0
125 # undef USE_FOR_NOMMU
128 # define USE_FOR_NOMMU(...) __VA_ARGS__
129 # define USE_FOR_MMU(...)
132 #define SKIP_definitions 1
133 #include "applet_tables.h"
134 #undef SKIP_definitions
136 /* STANDALONE does not make sense, and won't compile */
137 # undef CONFIG_FEATURE_SH_STANDALONE
138 # undef ENABLE_FEATURE_SH_STANDALONE
139 # undef IF_FEATURE_SH_STANDALONE
140 # undef IF_NOT_FEATURE_SH_STANDALONE
141 # define ENABLE_FEATURE_SH_STANDALONE 0
142 # define IF_FEATURE_SH_STANDALONE(...)
143 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
146 #if !ENABLE_HUSH_INTERACTIVE
147 # undef ENABLE_FEATURE_EDITING
148 # define ENABLE_FEATURE_EDITING 0
149 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
150 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
153 /* Do we support ANY keywords? */
154 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
155 # define HAS_KEYWORDS 1
156 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
157 # define IF_HAS_NO_KEYWORDS(...)
159 # define HAS_KEYWORDS 0
160 # define IF_HAS_KEYWORDS(...)
161 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
164 /* If you comment out one of these below, it will be #defined later
165 * to perform debug printfs to stderr: */
166 #define debug_printf(...) do {} while (0)
167 /* Finer-grained debug switches */
168 #define debug_printf_parse(...) do {} while (0)
169 #define debug_print_tree(a, b) do {} while (0)
170 #define debug_printf_exec(...) do {} while (0)
171 #define debug_printf_env(...) do {} while (0)
172 #define debug_printf_jobs(...) do {} while (0)
173 #define debug_printf_expand(...) do {} while (0)
174 #define debug_printf_glob(...) do {} while (0)
175 #define debug_printf_list(...) do {} while (0)
176 #define debug_printf_subst(...) do {} while (0)
177 #define debug_printf_clean(...) do {} while (0)
179 #define ERR_PTR ((void*)(long)1)
181 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
183 #define SPECIAL_VAR_SYMBOL 3
187 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
189 /* This supports saving pointers malloced in vfork child,
190 * to be freed in the parent.
193 typedef struct nommu_save_t {
195 struct variable *old_vars;
197 char **argv_from_re_execing;
201 typedef enum reserved_style {
210 #if ENABLE_HUSH_LOOPS
217 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
222 /* three pseudo-keywords support contrived "case" syntax: */
223 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
224 RES_MATCH , /* "word)" */
225 RES_CASE_BODY, /* "this command is inside CASE" */
232 typedef struct o_string {
234 int length; /* position where data is appended */
236 /* Protect newly added chars against globbing
237 * (by prepending \ to *, ?, [, \) */
240 /* At least some part of the string was inside '' or "",
241 * possibly empty one: word"", wo''rd etc. */
243 smallint has_empty_slot;
244 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
247 MAYBE_ASSIGNMENT = 0,
248 DEFINITELY_ASSIGNMENT = 1,
250 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
252 /* Used for initialization: o_string foo = NULL_O_STRING; */
253 #define NULL_O_STRING { NULL }
255 /* I can almost use ordinary FILE*. Is open_memstream() universally
256 * available? Where is it documented? */
257 typedef struct in_str {
259 /* eof_flag=1: last char in ->p is really an EOF */
260 char eof_flag; /* meaningless if ->p == NULL */
262 #if ENABLE_HUSH_INTERACTIVE
264 smallint promptmode; /* 0: PS1, 1: PS2 */
267 int (*get) (struct in_str *) FAST_FUNC;
268 int (*peek) (struct in_str *) FAST_FUNC;
270 #define i_getch(input) ((input)->get(input))
271 #define i_peek(input) ((input)->peek(input))
273 /* The descrip member of this structure is only used to make
274 * debugging output pretty */
275 static const struct {
277 signed char default_fd;
280 { O_RDONLY, 0, "<" },
281 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
282 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
283 { O_CREAT|O_RDWR, 1, "<>" },
284 { O_RDONLY, 0, "<<" },
285 /* Should not be needed. Bogus default_fd helps in debugging */
286 /* { O_RDONLY, 77, "<<" }, */
289 struct redir_struct {
290 struct redir_struct *next;
291 char *rd_filename; /* filename */
292 int rd_fd; /* fd to redirect */
293 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
295 smallint rd_type; /* (enum redir_type) */
296 /* note: for heredocs, rd_filename contains heredoc delimiter,
297 * and subsequently heredoc itself; and rd_dup is a bitmask:
298 * bit 0: do we need to trim leading tabs?
299 * bit 1: is heredoc quoted (<<'delim' syntax) ?
302 typedef enum redir_type {
304 REDIRECT_OVERWRITE = 1,
307 REDIRECT_HEREDOC = 4,
308 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
311 REDIRFD_SYNTAX_ERR = -2,
312 REDIRFD_TO_FILE = -1,
313 /* otherwise, rd_fd is redirected to rd_dup */
315 HEREDOC_SKIPTABS = 1,
321 pid_t pid; /* 0 if exited */
322 int assignment_cnt; /* how many argv[i] are assignments? */
323 smallint is_stopped; /* is the command currently running? */
324 smallint cmd_type; /* CMD_xxx */
326 #define CMD_SUBSHELL 1
328 /* used for "[[ EXPR ]]" */
329 #if ENABLE_HUSH_BASH_COMPAT
330 # define CMD_SINGLEWORD_NOGLOB 2
333 /* used for "export noglob=* glob* a=`echo a b`" */
334 //#define CMD_SINGLEWORD_NOGLOB_COND 3
335 // It is hard to implement correctly, it adds significant amounts of tricky code,
336 // and all this is only useful for really obscure export statements
337 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
338 // guards the code which implements it, but I have doubts it works
339 // in all cases (especially with mixed globbed/non-globbed arguments)
341 #if ENABLE_HUSH_FUNCTIONS
342 # define CMD_FUNCDEF 3
345 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
348 char *group_as_string;
350 #if ENABLE_HUSH_FUNCTIONS
351 struct function *child_func;
352 /* This field is used to prevent a bug here:
353 * while...do f1() {a;}; f1; f1() {b;}; f1; done
354 * When we execute "f1() {a;}" cmd, we create new function and clear
355 * cmd->group, cmd->group_as_string, cmd->argv[0].
356 * When we execute "f1() {b;}", we notice that f1 exists,
357 * and that its "parent cmd" struct is still "alive",
358 * we put those fields back into cmd->xxx
359 * (struct function has ->parent_cmd ptr to facilitate that).
360 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
361 * Without this trick, loop would execute a;b;b;b;...
362 * instead of correct sequence a;b;a;b;...
363 * When command is freed, it severs the link
364 * (sets ->child_func->parent_cmd to NULL).
367 char **argv; /* command name and arguments */
368 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
369 * and on execution these are substituted with their values.
370 * Substitution can make _several_ words out of one argv[n]!
371 * Example: argv[0]=='.^C*^C.' here: echo .$*.
372 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
374 struct redir_struct *redirects; /* I/O redirections */
376 /* Is there anything in this command at all? */
377 #define IS_NULL_CMD(cmd) \
378 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
383 int num_cmds; /* total number of commands in pipe */
384 int alive_cmds; /* number of commands running (not exited) */
385 int stopped_cmds; /* number of commands alive, but stopped */
387 int jobid; /* job number */
388 pid_t pgrp; /* process group ID for the job */
389 char *cmdtext; /* name of job */
391 struct command *cmds; /* array of commands in pipe */
392 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
393 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
394 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
396 typedef enum pipe_style {
402 /* Is there anything in this pipe at all? */
403 #define IS_NULL_PIPE(pi) \
404 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
406 /* This holds pointers to the various results of parsing */
407 struct parse_context {
408 /* linked list of pipes */
409 struct pipe *list_head;
410 /* last pipe (being constructed right now) */
412 /* last command in pipe (being constructed right now) */
413 struct command *command;
414 /* last redirect in command->redirects list */
415 struct redir_struct *pending_redirect;
421 smallint ctx_inverted; /* "! cmd | cmd" */
423 smallint ctx_dsemicolon; /* ";;" seen */
425 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
427 /* group we are enclosed in:
428 * example: "if pipe1; pipe2; then pipe3; fi"
429 * when we see "if" or "then", we malloc and copy current context,
430 * and make ->stack point to it. then we parse pipeN.
431 * when closing "then" / fi" / whatever is found,
432 * we move list_head into ->stack->command->group,
433 * copy ->stack into current context, and delete ->stack.
434 * (parsing of { list } and ( list ) doesn't use this method)
436 struct parse_context *stack;
440 /* On program start, environ points to initial environment.
441 * putenv adds new pointers into it, unsetenv removes them.
442 * Neither of these (de)allocates the strings.
443 * setenv allocates new strings in malloc space and does putenv,
444 * and thus setenv is unusable (leaky) for shell's purposes */
445 #define setenv(...) setenv_is_leaky_dont_use()
447 struct variable *next;
448 char *varstr; /* points to "name=" portion */
449 #if ENABLE_HUSH_LOCAL
450 unsigned func_nest_level;
452 int max_len; /* if > 0, name is part of initial env; else name is malloced */
453 smallint flg_export; /* putenv should be done on this var */
454 smallint flg_read_only;
462 #if ENABLE_HUSH_FUNCTIONS
464 struct function *next;
466 struct command *parent_cmd;
469 char *body_as_string;
475 /* "Globals" within this file */
476 /* Sorted roughly by size (smaller offsets == smaller code) */
478 /* interactive_fd != 0 means we are an interactive shell.
479 * If we are, then saved_tty_pgrp can also be != 0, meaning
480 * that controlling tty is available. With saved_tty_pgrp == 0,
481 * job control still works, but terminal signals
482 * (^C, ^Z, ^Y, ^\) won't work at all, and background
483 * process groups can only be created with "cmd &".
484 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
485 * to give tty to the foreground process group,
486 * and will take it back when the group is stopped (^Z)
489 #if ENABLE_HUSH_INTERACTIVE
490 /* 'interactive_fd' is a fd# open to ctty, if we have one
491 * _AND_ if we decided to act interactively */
495 # define G_interactive_fd (G.interactive_fd)
497 # define G_interactive_fd 0
499 #if ENABLE_FEATURE_EDITING
500 line_input_t *line_input_state;
505 #if ENABLE_HUSH_RANDOM_SUPPORT
511 pid_t saved_tty_pgrp;
512 struct pipe *job_list;
513 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
515 # define G_saved_tty_pgrp 0
517 smallint flag_SIGINT;
518 #if ENABLE_HUSH_LOOPS
519 smallint flag_break_continue;
521 #if ENABLE_HUSH_FUNCTIONS
522 /* 0: outside of a function (or sourced file)
523 * -1: inside of a function, ok to use return builtin
524 * 1: return is invoked, skip all till end of func
526 smallint flag_return_in_progress;
529 smallint exiting; /* used to prevent EXIT trap recursion */
530 /* These four support $?, $#, and $1 */
531 smalluint last_exitcode;
532 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
533 smalluint global_args_malloced;
534 smalluint inherited_set_is_saved;
535 /* how many non-NULL argv's we have. NB: $# + 1 */
539 char *argv0_for_re_execing;
541 #if ENABLE_HUSH_LOOPS
542 unsigned depth_break_continue;
543 unsigned depth_of_loop;
547 struct variable *top_var; /* = &G.shell_ver (set in main()) */
548 struct variable shell_ver;
549 #if ENABLE_HUSH_FUNCTIONS
550 struct function *top_func;
551 # if ENABLE_HUSH_LOCAL
552 struct variable **shadowed_vars_pp;
553 unsigned func_nest_level;
556 /* Signal and trap handling */
558 unsigned count_SIGCHLD;
559 unsigned handled_SIGCHLD;
560 smallint we_have_children;
562 /* which signals have non-DFL handler (even with no traps set)? */
563 unsigned non_DFL_mask;
564 char **traps; /* char *traps[NSIG] */
565 sigset_t blocked_set;
566 sigset_t inherited_set;
568 unsigned long memleak_value;
571 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
573 #define G (*ptr_to_globals)
574 /* Not #defining name to G.name - this quickly gets unwieldy
575 * (too many defines). Also, I actually prefer to see when a variable
576 * is global, thus "G." prefix is a useful hint */
577 #define INIT_G() do { \
578 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
582 /* Function prototypes for builtins */
583 static int builtin_cd(char **argv) FAST_FUNC;
584 static int builtin_echo(char **argv) FAST_FUNC;
585 static int builtin_eval(char **argv) FAST_FUNC;
586 static int builtin_exec(char **argv) FAST_FUNC;
587 static int builtin_exit(char **argv) FAST_FUNC;
588 static int builtin_export(char **argv) FAST_FUNC;
590 static int builtin_fg_bg(char **argv) FAST_FUNC;
591 static int builtin_jobs(char **argv) FAST_FUNC;
594 static int builtin_help(char **argv) FAST_FUNC;
596 #if ENABLE_HUSH_LOCAL
597 static int builtin_local(char **argv) FAST_FUNC;
600 static int builtin_memleak(char **argv) FAST_FUNC;
603 static int builtin_printf(char **argv) FAST_FUNC;
605 static int builtin_pwd(char **argv) FAST_FUNC;
606 static int builtin_read(char **argv) FAST_FUNC;
607 static int builtin_set(char **argv) FAST_FUNC;
608 static int builtin_shift(char **argv) FAST_FUNC;
609 static int builtin_source(char **argv) FAST_FUNC;
610 static int builtin_test(char **argv) FAST_FUNC;
611 static int builtin_trap(char **argv) FAST_FUNC;
612 static int builtin_type(char **argv) FAST_FUNC;
613 static int builtin_true(char **argv) FAST_FUNC;
614 static int builtin_umask(char **argv) FAST_FUNC;
615 static int builtin_unset(char **argv) FAST_FUNC;
616 static int builtin_wait(char **argv) FAST_FUNC;
617 #if ENABLE_HUSH_LOOPS
618 static int builtin_break(char **argv) FAST_FUNC;
619 static int builtin_continue(char **argv) FAST_FUNC;
621 #if ENABLE_HUSH_FUNCTIONS
622 static int builtin_return(char **argv) FAST_FUNC;
625 /* Table of built-in functions. They can be forked or not, depending on
626 * context: within pipes, they fork. As simple commands, they do not.
627 * When used in non-forking context, they can change global variables
628 * in the parent shell process. If forked, of course they cannot.
629 * For example, 'unset foo | whatever' will parse and run, but foo will
630 * still be set at the end. */
631 struct built_in_command {
633 int (*b_function)(char **argv) FAST_FUNC;
636 # define BLTIN(cmd, func, help) { cmd, func, help }
638 # define BLTIN(cmd, func, help) { cmd, func }
642 static const struct built_in_command bltins1[] = {
643 BLTIN("." , builtin_source , "Run commands in a file"),
644 BLTIN(":" , builtin_true , NULL),
646 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
648 #if ENABLE_HUSH_LOOPS
649 BLTIN("break" , builtin_break , "Exit from a loop"),
651 BLTIN("cd" , builtin_cd , "Change directory"),
652 #if ENABLE_HUSH_LOOPS
653 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
655 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
656 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
657 BLTIN("exit" , builtin_exit , "Exit"),
658 BLTIN("export" , builtin_export , "Set environment variables"),
660 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
663 BLTIN("help" , builtin_help , NULL),
666 BLTIN("jobs" , builtin_jobs , "List jobs"),
668 #if ENABLE_HUSH_LOCAL
669 BLTIN("local" , builtin_local , "Set local variables"),
672 BLTIN("memleak" , builtin_memleak , NULL),
674 BLTIN("read" , builtin_read , "Input into variable"),
675 #if ENABLE_HUSH_FUNCTIONS
676 BLTIN("return" , builtin_return , "Return from a function"),
678 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
679 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
680 #if ENABLE_HUSH_BASH_COMPAT
681 BLTIN("source" , builtin_source , "Run commands in a file"),
683 BLTIN("trap" , builtin_trap , "Trap signals"),
684 BLTIN("type" , builtin_type , "Show command type"),
685 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
686 BLTIN("umask" , builtin_umask , "Set file creation mask"),
687 BLTIN("unset" , builtin_unset , "Unset variables"),
688 BLTIN("wait" , builtin_wait , "Wait for process"),
690 /* For now, echo and test are unconditionally enabled.
691 * Maybe make it configurable? */
692 static const struct built_in_command bltins2[] = {
693 BLTIN("[" , builtin_test , NULL),
694 BLTIN("echo" , builtin_echo , NULL),
696 BLTIN("printf" , builtin_printf , NULL),
698 BLTIN("pwd" , builtin_pwd , NULL),
699 BLTIN("test" , builtin_test , NULL),
706 /* prevent disasters with G.debug_indent < 0 */
707 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
708 # define debug_enter() (G.debug_indent++)
709 # define debug_leave() (G.debug_indent--)
711 # define indent() ((void)0)
712 # define debug_enter() ((void)0)
713 # define debug_leave() ((void)0)
717 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
720 #ifndef debug_printf_parse
721 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
724 #ifndef debug_printf_exec
725 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
728 #ifndef debug_printf_env
729 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
732 #ifndef debug_printf_jobs
733 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
734 # define DEBUG_JOBS 1
736 # define DEBUG_JOBS 0
739 #ifndef debug_printf_expand
740 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
741 # define DEBUG_EXPAND 1
743 # define DEBUG_EXPAND 0
746 #ifndef debug_printf_glob
747 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
748 # define DEBUG_GLOB 1
750 # define DEBUG_GLOB 0
753 #ifndef debug_printf_list
754 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
757 #ifndef debug_printf_subst
758 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
761 #ifndef debug_printf_clean
762 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
763 # define DEBUG_CLEAN 1
765 # define DEBUG_CLEAN 0
769 static void debug_print_strings(const char *prefix, char **vv)
772 fprintf(stderr, "%s:\n", prefix);
774 fprintf(stderr, " '%s'\n", *vv++);
777 # define debug_print_strings(prefix, vv) ((void)0)
781 /* Leak hunting. Use hush_leaktool.sh for post-processing.
784 static void *xxmalloc(int lineno, size_t size)
786 void *ptr = xmalloc((size + 0xff) & ~0xff);
787 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
790 static void *xxrealloc(int lineno, void *ptr, size_t size)
792 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
793 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
796 static char *xxstrdup(int lineno, const char *str)
798 char *ptr = xstrdup(str);
799 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
802 static void xxfree(void *ptr)
804 fdprintf(2, "free %p\n", ptr);
807 #define xmalloc(s) xxmalloc(__LINE__, s)
808 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
809 #define xstrdup(s) xxstrdup(__LINE__, s)
810 #define free(p) xxfree(p)
814 /* Syntax and runtime errors. They always abort scripts.
815 * In interactive use they usually discard unparsed and/or unexecuted commands
816 * and return to the prompt.
817 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
820 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
821 # define syntax_error(lineno, msg) syntax_error(msg)
822 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
823 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
824 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
825 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
828 static void die_if_script(unsigned lineno, const char *fmt, ...)
833 bb_error_msg("hush.c:%u", lineno);
836 bb_verror_msg(fmt, p, NULL);
838 if (!G_interactive_fd)
842 static void syntax_error(unsigned lineno, const char *msg)
845 die_if_script(lineno, "syntax error: %s", msg);
847 die_if_script(lineno, "syntax error", NULL);
850 static void syntax_error_at(unsigned lineno, const char *msg)
852 die_if_script(lineno, "syntax error at '%s'", msg);
855 static void syntax_error_unterm_str(unsigned lineno, const char *s)
857 die_if_script(lineno, "syntax error: unterminated %s", s);
860 /* It so happens that all such cases are totally fatal
861 * even if shell is interactive: EOF while looking for closing
862 * delimiter. There is nowhere to read stuff from after that,
863 * it's EOF! The only choice is to terminate.
865 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
866 static void syntax_error_unterm_ch(unsigned lineno, char ch)
868 char msg[2] = { ch, '\0' };
869 syntax_error_unterm_str(lineno, msg);
873 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
878 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
882 # undef die_if_script
884 # undef syntax_error_at
885 # undef syntax_error_unterm_ch
886 # undef syntax_error_unterm_str
887 # undef syntax_error_unexpected_ch
889 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
890 # define syntax_error(msg) syntax_error(__LINE__, msg)
891 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
892 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
893 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
894 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
898 #if ENABLE_HUSH_INTERACTIVE
899 static void cmdedit_update_prompt(void);
901 # define cmdedit_update_prompt() ((void)0)
907 /* Replace each \x with x in place, return ptr past NUL. */
908 static char *unbackslash(char *src)
910 char *dst = src = strchrnul(src, '\\');
914 if ((*dst++ = *src++) == '\0')
920 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
941 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
942 v[count1 + count2] = NULL;
945 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
949 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
951 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
952 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
955 #define add_strings_to_strings(strings, add, need_to_dup) \
956 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
959 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
960 static char **add_string_to_strings(char **strings, char *add)
965 return add_strings_to_strings(strings, v, /*dup:*/ 0);
968 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
970 char **ptr = add_string_to_strings(strings, add);
971 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
974 #define add_string_to_strings(strings, add) \
975 xx_add_string_to_strings(__LINE__, strings, add)
978 static void free_strings(char **strings)
993 /* Helpers for setting new $n and restoring them back
995 typedef struct save_arg_t {
999 smallint sv_g_malloced;
1002 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1006 sv->sv_argv0 = argv[0];
1007 sv->sv_g_argv = G.global_argv;
1008 sv->sv_g_argc = G.global_argc;
1009 sv->sv_g_malloced = G.global_args_malloced;
1011 argv[0] = G.global_argv[0]; /* retain $0 */
1012 G.global_argv = argv;
1013 G.global_args_malloced = 0;
1021 static void restore_G_args(save_arg_t *sv, char **argv)
1025 if (G.global_args_malloced) {
1026 /* someone ran "set -- arg1 arg2 ...", undo */
1028 while (*++pp) /* note: does not free $0 */
1030 free(G.global_argv);
1032 argv[0] = sv->sv_argv0;
1033 G.global_argv = sv->sv_g_argv;
1034 G.global_argc = sv->sv_g_argc;
1035 G.global_args_malloced = sv->sv_g_malloced;
1039 /* Basic theory of signal handling in shell
1040 * ========================================
1041 * This does not describe what hush does, rather, it is current understanding
1042 * what it _should_ do. If it doesn't, it's a bug.
1043 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1045 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1046 * is finished or backgrounded. It is the same in interactive and
1047 * non-interactive shells, and is the same regardless of whether
1048 * a user trap handler is installed or a shell special one is in effect.
1049 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1050 * backgrounds (i.e. stops) or kills all members of currently running
1053 * Wait builtin in interruptible by signals for which user trap is set
1054 * or by SIGINT in interactive shell.
1056 * Trap handlers will execute even within trap handlers. (right?)
1058 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1059 * except for handlers set to '' (empty string).
1061 * If job control is off, backgrounded commands ("cmd &")
1062 * have SIGINT, SIGQUIT set to SIG_IGN.
1064 * Commands which are run in command substitution ("`cmd`")
1065 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1067 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1068 * by the shell from its parent.
1070 * Signals which differ from SIG_DFL action
1071 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1074 * SIGTERM (interactive): ignore
1075 * SIGHUP (interactive):
1076 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1077 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1078 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1079 * that all pipe members are stopped. Try this in bash:
1080 * while :; do :; done - ^Z does not background it
1081 * (while :; do :; done) - ^Z backgrounds it
1082 * SIGINT (interactive): wait for last pipe, ignore the rest
1083 * of the command line, show prompt. NB: ^C does not send SIGINT
1084 * to interactive shell while shell is waiting for a pipe,
1085 * since shell is bg'ed (is not in foreground process group).
1086 * Example 1: this waits 5 sec, but does not execute ls:
1087 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1088 * Example 2: this does not wait and does not execute ls:
1089 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1090 * Example 3: this does not wait 5 sec, but executes ls:
1091 * "sleep 5; ls -l" + press ^C
1093 * (What happens to signals which are IGN on shell start?)
1094 * (What happens with signal mask on shell start?)
1096 * Implementation in hush
1097 * ======================
1098 * We use in-kernel pending signal mask to determine which signals were sent.
1099 * We block all signals which we don't want to take action immediately,
1100 * i.e. we block all signals which need to have special handling as described
1101 * above, and all signals which have traps set.
1102 * After each pipe execution, we extract any pending signals via sigtimedwait()
1105 * unsigned non_DFL_mask: a mask of such "special" signals
1106 * sigset_t blocked_set: current blocked signal set
1109 * clear bit in blocked_set unless it is also in non_DFL_mask
1110 * "trap 'cmd' SIGxxx":
1111 * set bit in blocked_set (even if 'cmd' is '')
1112 * after [v]fork, if we plan to be a shell:
1113 * unblock signals with special interactive handling
1114 * (child shell is not interactive),
1115 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1116 * after [v]fork, if we plan to exec:
1117 * POSIX says fork clears pending signal mask in child - no need to clear it.
1118 * Restore blocked signal set to one inherited by shell just prior to exec.
1120 * Note: as a result, we do not use signal handlers much. The only uses
1121 * are to count SIGCHLDs
1122 * and to restore tty pgrp on signal-induced exit.
1125 * Standard says "When a subshell is entered, traps that are not being ignored
1126 * are set to the default actions". bash interprets it so that traps which
1127 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1130 SPECIAL_INTERACTIVE_SIGS = 0
1135 SPECIAL_JOB_SIGS = 0
1143 #if ENABLE_HUSH_FAST
1144 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1147 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1153 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1154 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1155 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1156 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1158 /* Restores tty foreground process group, and exits.
1159 * May be called as signal handler for fatal signal
1160 * (will resend signal to itself, producing correct exit state)
1161 * or called directly with -EXITCODE.
1162 * We also call it if xfunc is exiting. */
1163 static void sigexit(int sig) NORETURN;
1164 static void sigexit(int sig)
1166 /* Disable all signals: job control, SIGPIPE, etc. */
1167 sigprocmask_allsigs(SIG_BLOCK);
1169 /* Careful: we can end up here after [v]fork. Do not restore
1170 * tty pgrp then, only top-level shell process does that */
1171 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1172 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1174 /* Not a signal, just exit */
1178 kill_myself_with_sig(sig); /* does not return */
1182 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1183 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1187 /* Restores tty foreground process group, and exits. */
1188 static void hush_exit(int exitcode) NORETURN;
1189 static void hush_exit(int exitcode)
1191 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1192 /* Prevent recursion:
1193 * trap "echo Hi; exit" EXIT; exit
1195 char *argv[] = { NULL, G.traps[0], NULL };
1204 sigexit(- (exitcode & 0xff));
1210 static int check_and_run_traps(int sig)
1212 static const struct timespec zero_timespec = { 0, 0 };
1213 smalluint save_rcode;
1219 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1224 if (G.traps && G.traps[sig]) {
1225 if (G.traps[sig][0]) {
1226 /* We have user-defined handler */
1227 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1228 save_rcode = G.last_exitcode;
1231 G.last_exitcode = save_rcode;
1232 } /* else: "" trap, ignoring signal */
1235 /* not a trap: special action */
1237 #if ENABLE_HUSH_FAST
1240 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1244 /* Builtin was ^C'ed, make it look prettier: */
1251 /* bash is observed to signal whole process groups,
1252 * not individual processes */
1253 for (job = G.job_list; job; job = job->next) {
1256 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1257 if (kill(- job->pgrp, SIGHUP) == 0)
1258 kill(- job->pgrp, SIGCONT);
1263 default: /* ignored: */
1264 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1272 static const char *get_cwd(int force)
1274 if (force || G.cwd == NULL) {
1275 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1276 * we must not try to free(bb_msg_unknown) */
1277 if (G.cwd == bb_msg_unknown)
1279 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1281 G.cwd = bb_msg_unknown;
1288 * Shell and environment variable support
1290 static struct variable **get_ptr_to_local_var(const char *name)
1292 struct variable **pp;
1293 struct variable *cur;
1298 while ((cur = *pp) != NULL) {
1299 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1306 static struct variable *get_local_var(const char *name)
1308 struct variable **pp = get_ptr_to_local_var(name);
1314 static const char* FAST_FUNC get_local_var_value(const char *name)
1316 struct variable **pp = get_ptr_to_local_var(name);
1318 return strchr((*pp)->varstr, '=') + 1;
1319 if (strcmp(name, "PPID") == 0)
1320 return utoa(G.root_ppid);
1321 // bash compat: UID? EUID?
1322 #if ENABLE_HUSH_RANDOM_SUPPORT
1323 if (strcmp(name, "RANDOM") == 0) {
1324 return utoa(next_random(&G.random_gen));
1330 /* str holds "NAME=VAL" and is expected to be malloced.
1331 * We take ownership of it.
1333 * 0: do not change export flag
1334 * (if creating new variable, flag will be 0)
1335 * 1: set export flag and putenv the variable
1336 * -1: clear export flag and unsetenv the variable
1337 * flg_read_only is set only when we handle -R var=val
1339 #if !BB_MMU && ENABLE_HUSH_LOCAL
1340 /* all params are used */
1341 #elif BB_MMU && ENABLE_HUSH_LOCAL
1342 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1343 set_local_var(str, flg_export, local_lvl)
1344 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1345 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1346 set_local_var(str, flg_export)
1347 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1348 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1349 set_local_var(str, flg_export, flg_read_only)
1351 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1353 struct variable **var_pp;
1354 struct variable *cur;
1358 eq_sign = strchr(str, '=');
1359 if (!eq_sign) { /* not expected to ever happen? */
1364 name_len = eq_sign - str + 1; /* including '=' */
1365 var_pp = &G.top_var;
1366 while ((cur = *var_pp) != NULL) {
1367 if (strncmp(cur->varstr, str, name_len) != 0) {
1368 var_pp = &cur->next;
1371 /* We found an existing var with this name */
1372 if (cur->flg_read_only) {
1376 bb_error_msg("%s: readonly variable", str);
1380 if (flg_export == -1) { // "&& cur->flg_export" ?
1381 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1386 #if ENABLE_HUSH_LOCAL
1387 if (cur->func_nest_level < local_lvl) {
1388 /* New variable is declared as local,
1389 * and existing one is global, or local
1390 * from enclosing function.
1391 * Remove and save old one: */
1392 *var_pp = cur->next;
1393 cur->next = *G.shadowed_vars_pp;
1394 *G.shadowed_vars_pp = cur;
1395 /* bash 3.2.33(1) and exported vars:
1397 * # f() { local z=a; env | grep ^z; }
1403 if (cur->flg_export)
1408 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1413 if (cur->max_len != 0) {
1414 if (cur->max_len >= strlen(str)) {
1415 /* This one is from startup env, reuse space */
1416 strcpy(cur->varstr, str);
1420 /* max_len == 0 signifies "malloced" var, which we can
1421 * (and has to) free */
1425 goto set_str_and_exp;
1428 /* Not found - create new variable struct */
1429 cur = xzalloc(sizeof(*cur));
1430 #if ENABLE_HUSH_LOCAL
1431 cur->func_nest_level = local_lvl;
1433 cur->next = *var_pp;
1439 cur->flg_read_only = flg_read_only;
1442 if (flg_export == 1)
1443 cur->flg_export = 1;
1444 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1445 cmdedit_update_prompt();
1446 if (cur->flg_export) {
1447 if (flg_export == -1) {
1448 cur->flg_export = 0;
1449 /* unsetenv was already done */
1451 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1452 return putenv(cur->varstr);
1458 /* Used at startup and after each cd */
1459 static void set_pwd_var(int exp)
1461 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1462 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1465 static int unset_local_var_len(const char *name, int name_len)
1467 struct variable *cur;
1468 struct variable **var_pp;
1471 return EXIT_SUCCESS;
1472 var_pp = &G.top_var;
1473 while ((cur = *var_pp) != NULL) {
1474 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1475 if (cur->flg_read_only) {
1476 bb_error_msg("%s: readonly variable", name);
1477 return EXIT_FAILURE;
1479 *var_pp = cur->next;
1480 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1481 bb_unsetenv(cur->varstr);
1482 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1483 cmdedit_update_prompt();
1487 return EXIT_SUCCESS;
1489 var_pp = &cur->next;
1491 return EXIT_SUCCESS;
1494 static int unset_local_var(const char *name)
1496 return unset_local_var_len(name, strlen(name));
1499 static void unset_vars(char **strings)
1507 const char *eq = strchrnul(*v, '=');
1508 unset_local_var_len(*v, (int)(eq - *v));
1514 #if ENABLE_SH_MATH_SUPPORT
1515 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1516 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1517 static char* FAST_FUNC endofname(const char *name)
1525 if (!is_in_name(*p))
1532 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1534 char *var = xasprintf("%s=%s", name, val);
1535 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1540 * Helpers for "var1=val1 var2=val2 cmd" feature
1542 static void add_vars(struct variable *var)
1544 struct variable *next;
1548 var->next = G.top_var;
1550 if (var->flg_export) {
1551 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1552 putenv(var->varstr);
1554 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1560 static struct variable *set_vars_and_save_old(char **strings)
1563 struct variable *old = NULL;
1569 struct variable *var_p;
1570 struct variable **var_pp;
1573 eq = strchr(*s, '=');
1576 var_pp = get_ptr_to_local_var(*s);
1579 /* Remove variable from global linked list */
1581 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1582 *var_pp = var_p->next;
1583 /* Add it to returned list */
1587 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1598 static int FAST_FUNC static_get(struct in_str *i)
1607 static int FAST_FUNC static_peek(struct in_str *i)
1612 #if ENABLE_HUSH_INTERACTIVE
1614 static void cmdedit_update_prompt(void)
1616 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1617 G.PS1 = get_local_var_value("PS1");
1620 G.PS2 = get_local_var_value("PS2");
1628 static const char* setup_prompt_string(int promptmode)
1630 const char *prompt_str;
1631 debug_printf("setup_prompt_string %d ", promptmode);
1632 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1633 /* Set up the prompt */
1634 if (promptmode == 0) { /* PS1 */
1636 /* bash uses $PWD value, even if it is set by user.
1637 * It uses current dir only if PWD is unset.
1638 * We always use current dir. */
1639 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1644 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1645 debug_printf("result '%s'\n", prompt_str);
1649 static void get_user_input(struct in_str *i)
1652 const char *prompt_str;
1654 prompt_str = setup_prompt_string(i->promptmode);
1655 #if ENABLE_FEATURE_EDITING
1656 /* Enable command line editing only while a command line
1657 * is actually being read */
1660 /* buglet: SIGINT will not make new prompt to appear _at once_,
1661 * only after <Enter>. (^C will work) */
1662 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1663 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1664 check_and_run_traps(0);
1665 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1666 i->eof_flag = (r < 0);
1667 if (i->eof_flag) { /* EOF/error detected */
1668 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1669 G.user_input_buf[1] = '\0';
1674 fputs(prompt_str, stdout);
1676 G.user_input_buf[0] = r = fgetc(i->file);
1677 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1678 //do we need check_and_run_traps(0)? (maybe only if stdin)
1679 } while (G.flag_SIGINT);
1680 i->eof_flag = (r == EOF);
1682 i->p = G.user_input_buf;
1685 #endif /* INTERACTIVE */
1687 /* This is the magic location that prints prompts
1688 * and gets data back from the user */
1689 static int FAST_FUNC file_get(struct in_str *i)
1693 /* If there is data waiting, eat it up */
1694 if (i->p && *i->p) {
1695 #if ENABLE_HUSH_INTERACTIVE
1699 if (i->eof_flag && !*i->p)
1701 /* note: ch is never NUL */
1703 /* need to double check i->file because we might be doing something
1704 * more complicated by now, like sourcing or substituting. */
1705 #if ENABLE_HUSH_INTERACTIVE
1706 if (G_interactive_fd && i->promptme && i->file == stdin) {
1709 } while (!*i->p); /* need non-empty line */
1710 i->promptmode = 1; /* PS2 */
1715 do ch = fgetc(i->file); while (ch == '\0');
1717 debug_printf("file_get: got '%c' %d\n", ch, ch);
1718 #if ENABLE_HUSH_INTERACTIVE
1725 /* All callers guarantee this routine will never
1726 * be used right after a newline, so prompting is not needed.
1728 static int FAST_FUNC file_peek(struct in_str *i)
1731 if (i->p && *i->p) {
1732 if (i->eof_flag && !i->p[1])
1735 /* note: ch is never NUL */
1737 do ch = fgetc(i->file); while (ch == '\0');
1738 i->eof_flag = (ch == EOF);
1739 i->peek_buf[0] = ch;
1740 i->peek_buf[1] = '\0';
1742 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1746 static void setup_file_in_str(struct in_str *i, FILE *f)
1748 i->peek = file_peek;
1750 #if ENABLE_HUSH_INTERACTIVE
1752 i->promptmode = 0; /* PS1 */
1758 static void setup_string_in_str(struct in_str *i, const char *s)
1760 i->peek = static_peek;
1761 i->get = static_get;
1762 #if ENABLE_HUSH_INTERACTIVE
1764 i->promptmode = 0; /* PS1 */
1774 #define B_CHUNK (32 * sizeof(char*))
1776 static void o_reset_to_empty_unquoted(o_string *o)
1784 static void o_free(o_string *o)
1787 memset(o, 0, sizeof(*o));
1790 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1795 static void o_grow_by(o_string *o, int len)
1797 if (o->length + len > o->maxlen) {
1798 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1799 o->data = xrealloc(o->data, 1 + o->maxlen);
1803 static void o_addchr(o_string *o, int ch)
1805 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1807 o->data[o->length] = ch;
1809 o->data[o->length] = '\0';
1812 static void o_addblock(o_string *o, const char *str, int len)
1815 memcpy(&o->data[o->length], str, len);
1817 o->data[o->length] = '\0';
1821 static void o_addstr(o_string *o, const char *str)
1823 o_addblock(o, str, strlen(str));
1825 static void nommu_addchr(o_string *o, int ch)
1831 # define nommu_addchr(o, str) ((void)0)
1834 static void o_addstr_with_NUL(o_string *o, const char *str)
1836 o_addblock(o, str, strlen(str) + 1);
1839 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1844 && (*str != '*' && *str != '?' && *str != '[')
1852 #undef HUSH_BRACE_EXP
1854 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1855 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1856 * Apparently, on unquoted $v bash still does globbing
1857 * ("v='*.txt'; echo $v" prints all .txt files),
1858 * but NOT brace expansion! Thus, there should be TWO independent
1859 * quoting mechanisms on $v expansion side: one protects
1860 * $v from brace expansion, and other additionally protects "$v" against globbing.
1861 * We have only second one.
1864 #ifdef HUSH_BRACE_EXP
1865 # define MAYBE_BRACES "{}"
1867 # define MAYBE_BRACES ""
1870 /* My analysis of quoting semantics tells me that state information
1871 * is associated with a destination, not a source.
1873 static void o_addqchr(o_string *o, int ch)
1876 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1881 o->data[o->length] = '\\';
1884 o->data[o->length] = ch;
1886 o->data[o->length] = '\0';
1889 static void o_addQchr(o_string *o, int ch)
1892 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1894 o->data[o->length] = '\\';
1898 o->data[o->length] = ch;
1900 o->data[o->length] = '\0';
1903 static void o_addQstr(o_string *o, const char *str, int len)
1906 o_addblock(o, str, len);
1912 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1913 if (ordinary_cnt > len) /* paranoia */
1915 o_addblock(o, str, ordinary_cnt);
1916 if (ordinary_cnt == len)
1918 str += ordinary_cnt;
1919 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1923 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1925 o->data[o->length] = '\\';
1929 o->data[o->length] = ch;
1931 o->data[o->length] = '\0';
1935 /* A special kind of o_string for $VAR and `cmd` expansion.
1936 * It contains char* list[] at the beginning, which is grown in 16 element
1937 * increments. Actual string data starts at the next multiple of 16 * (char*).
1938 * list[i] contains an INDEX (int!) into this string data.
1939 * It means that if list[] needs to grow, data needs to be moved higher up
1940 * but list[i]'s need not be modified.
1941 * NB: remembering how many list[i]'s you have there is crucial.
1942 * o_finalize_list() operation post-processes this structure - calculates
1943 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1945 #if DEBUG_EXPAND || DEBUG_GLOB
1946 static void debug_print_list(const char *prefix, o_string *o, int n)
1948 char **list = (char**)o->data;
1949 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1953 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1954 prefix, list, n, string_start, o->length, o->maxlen);
1957 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1958 o->data + (int)list[i] + string_start,
1959 o->data + (int)list[i] + string_start);
1963 const char *p = o->data + (int)list[n - 1] + string_start;
1965 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1969 # define debug_print_list(prefix, o, n) ((void)0)
1972 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1973 * in list[n] so that it points past last stored byte so far.
1974 * It returns n+1. */
1975 static int o_save_ptr_helper(o_string *o, int n)
1977 char **list = (char**)o->data;
1981 if (!o->has_empty_slot) {
1982 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1983 string_len = o->length - string_start;
1984 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1985 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1986 /* list[n] points to string_start, make space for 16 more pointers */
1987 o->maxlen += 0x10 * sizeof(list[0]);
1988 o->data = xrealloc(o->data, o->maxlen + 1);
1989 list = (char**)o->data;
1990 memmove(list + n + 0x10, list + n, string_len);
1991 o->length += 0x10 * sizeof(list[0]);
1993 debug_printf_list("list[%d]=%d string_start=%d\n",
1994 n, string_len, string_start);
1997 /* We have empty slot at list[n], reuse without growth */
1998 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1999 string_len = o->length - string_start;
2000 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2001 n, string_len, string_start);
2002 o->has_empty_slot = 0;
2004 list[n] = (char*)(ptrdiff_t)string_len;
2008 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2009 static int o_get_last_ptr(o_string *o, int n)
2011 char **list = (char**)o->data;
2012 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2014 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2017 #ifdef HUSH_BRACE_EXP
2018 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2019 * first, it processes even {a} (no commas), second,
2020 * I didn't manage to make it return strings when they don't match
2021 * existing files. Need to re-implement it.
2025 static int glob_needed(const char *s)
2034 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2040 /* Return pointer to next closing brace or to comma */
2041 static const char *next_brace_sub(const char *cp)
2045 while (*cp != '\0') {
2052 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2054 if (*cp++ == '{') /*}*/
2058 return *cp != '\0' ? cp : NULL;
2060 /* Recursive brace globber. Note: may garble pattern[]. */
2061 static int glob_brace(char *pattern, o_string *o, int n)
2063 char *new_pattern_buf;
2070 debug_printf_glob("glob_brace('%s')\n", pattern);
2076 if (*begin == '{') /*}*/ {
2077 /* Find the first sub-pattern and at the same time
2078 * find the rest after the closing brace */
2079 next = next_brace_sub(begin);
2081 /* An illegal expression */
2084 /*{*/ if (*next == '}') {
2085 /* "{abc}" with no commas - illegal
2086 * brace expr, disregard and skip it */
2092 if (*begin == '\\' && begin[1] != '\0')
2096 debug_printf_glob("begin:%s\n", begin);
2097 debug_printf_glob("next:%s\n", next);
2099 /* Now find the end of the whole brace expression */
2101 /*{*/ while (*rest != '}') {
2102 rest = next_brace_sub(rest);
2104 /* An illegal expression */
2107 debug_printf_glob("rest:%s\n", rest);
2109 rest_len = strlen(++rest) + 1;
2111 /* We are sure the brace expression is well-formed */
2113 /* Allocate working buffer large enough for our work */
2114 new_pattern_buf = xmalloc(strlen(pattern));
2116 /* We have a brace expression. BEGIN points to the opening {,
2117 * NEXT points past the terminator of the first element, and REST
2118 * points past the final }. We will accumulate result names from
2119 * recursive runs for each brace alternative in the buffer using
2124 /* Construct the new glob expression */
2127 mempcpy(new_pattern_buf,
2128 /* We know the prefix for all sub-patterns */
2129 pattern, begin - pattern),
2133 /* Note: glob_brace() may garble new_pattern_buf[].
2134 * That's why we re-copy prefix every time (1st memcpy above).
2136 n = glob_brace(new_pattern_buf, o, n);
2137 /*{*/ if (*next == '}') {
2138 /* We saw the last entry */
2142 next = next_brace_sub(next);
2144 free(new_pattern_buf);
2152 memset(&globdata, 0, sizeof(globdata));
2153 gr = glob(pattern, 0, NULL, &globdata);
2154 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2156 if (gr == GLOB_NOMATCH) {
2157 globfree(&globdata);
2158 /* NB: garbles parameter */
2159 unbackslash(pattern);
2160 o_addstr_with_NUL(o, pattern);
2161 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2162 return o_save_ptr_helper(o, n);
2164 if (gr == GLOB_NOSPACE)
2165 bb_error_msg_and_die(bb_msg_memory_exhausted);
2166 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2167 * but we didn't specify it. Paranoia again. */
2168 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2170 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2171 char **argv = globdata.gl_pathv;
2173 o_addstr_with_NUL(o, *argv);
2174 n = o_save_ptr_helper(o, n);
2180 globfree(&globdata);
2184 /* Performs globbing on last list[],
2185 * saving each result as a new list[].
2187 static int o_glob(o_string *o, int n)
2189 char *pattern, *copy;
2191 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2193 return o_save_ptr_helper(o, n);
2194 pattern = o->data + o_get_last_ptr(o, n);
2195 debug_printf_glob("glob pattern '%s'\n", pattern);
2196 if (!glob_needed(pattern)) {
2197 /* unbackslash last string in o in place, fix length */
2198 o->length = unbackslash(pattern) - o->data;
2199 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2200 return o_save_ptr_helper(o, n);
2203 copy = xstrdup(pattern);
2204 /* "forget" pattern in o */
2205 o->length = pattern - o->data;
2206 n = glob_brace(copy, o, n);
2209 debug_print_list("o_glob returning", o, n);
2216 static int glob_needed(const char *s)
2225 if (*s == '*' || *s == '[' || *s == '?')
2231 /* Performs globbing on last list[],
2232 * saving each result as a new list[].
2234 static int o_glob(o_string *o, int n)
2240 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2242 return o_save_ptr_helper(o, n);
2243 pattern = o->data + o_get_last_ptr(o, n);
2244 debug_printf_glob("glob pattern '%s'\n", pattern);
2245 if (!glob_needed(pattern)) {
2247 /* unbackslash last string in o in place, fix length */
2248 o->length = unbackslash(pattern) - o->data;
2249 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2250 return o_save_ptr_helper(o, n);
2253 memset(&globdata, 0, sizeof(globdata));
2254 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2255 * If we glob "*.\*" and don't find anything, we need
2256 * to fall back to using literal "*.*", but GLOB_NOCHECK
2257 * will return "*.\*"!
2259 gr = glob(pattern, 0, NULL, &globdata);
2260 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2262 if (gr == GLOB_NOMATCH) {
2263 globfree(&globdata);
2266 if (gr == GLOB_NOSPACE)
2267 bb_error_msg_and_die(bb_msg_memory_exhausted);
2268 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2269 * but we didn't specify it. Paranoia again. */
2270 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2272 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2273 char **argv = globdata.gl_pathv;
2274 /* "forget" pattern in o */
2275 o->length = pattern - o->data;
2277 o_addstr_with_NUL(o, *argv);
2278 n = o_save_ptr_helper(o, n);
2284 globfree(&globdata);
2286 debug_print_list("o_glob returning", o, n);
2292 /* If o->o_glob == 1, glob the string so far remembered.
2293 * Otherwise, just finish current list[] and start new */
2294 static int o_save_ptr(o_string *o, int n)
2296 if (o->o_glob) { /* if globbing is requested */
2297 /* If o->has_empty_slot, list[n] was already globbed
2298 * (if it was requested back then when it was filled)
2299 * so don't do that again! */
2300 if (!o->has_empty_slot)
2301 return o_glob(o, n); /* o_save_ptr_helper is inside */
2303 return o_save_ptr_helper(o, n);
2306 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2307 static char **o_finalize_list(o_string *o, int n)
2312 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2314 debug_print_list("finalized", o, n);
2315 debug_printf_expand("finalized n:%d\n", n);
2316 list = (char**)o->data;
2317 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2321 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2327 /* Expansion can recurse */
2328 #if ENABLE_HUSH_TICK
2329 static int process_command_subs(o_string *dest, const char *s);
2331 static char *expand_string_to_string(const char *str);
2333 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2334 parse_stream_dquoted(dest, input, dquote_end)
2336 static int parse_stream_dquoted(o_string *as_string,
2338 struct in_str *input,
2341 /* expand_strvec_to_strvec() takes a list of strings, expands
2342 * all variable references within and returns a pointer to
2343 * a list of expanded strings, possibly with larger number
2344 * of strings. (Think VAR="a b"; echo $VAR).
2345 * This new list is allocated as a single malloc block.
2346 * NULL-terminated list of char* pointers is at the beginning of it,
2347 * followed by strings themself.
2348 * Caller can deallocate entire list by single free(list). */
2350 /* Store given string, finalizing the word and starting new one whenever
2351 * we encounter IFS char(s). This is used for expanding variable values.
2352 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2353 static int expand_on_ifs(o_string *output, int n, const char *str)
2356 int word_len = strcspn(str, G.ifs);
2358 if (output->o_escape || !output->o_glob)
2359 o_addQstr(output, str, word_len);
2360 else /* protect backslashes against globbing up :) */
2361 o_addblock_duplicate_backslash(output, str, word_len);
2364 if (!*str) /* EOL - do not finalize word */
2366 o_addchr(output, '\0');
2367 debug_print_list("expand_on_ifs", output, n);
2368 n = o_save_ptr(output, n);
2369 str += strspn(str, G.ifs); /* skip ifs chars */
2371 debug_print_list("expand_on_ifs[1]", output, n);
2375 /* Helper to expand $((...)) and heredoc body. These act as if
2376 * they are in double quotes, with the exception that they are not :).
2377 * Just the rules are similar: "expand only $var and `cmd`"
2379 * Returns malloced string.
2380 * As an optimization, we return NULL if expansion is not needed.
2382 static char *expand_pseudo_dquoted(const char *str)
2385 struct in_str input;
2386 o_string dest = NULL_O_STRING;
2388 if (strchr(str, '$') == NULL
2389 #if ENABLE_HUSH_TICK
2390 && strchr(str, '`') == NULL
2396 /* We need to expand. Example:
2397 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2399 setup_string_in_str(&input, str);
2400 parse_stream_dquoted(NULL, &dest, &input, EOF);
2401 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2402 exp_str = expand_string_to_string(dest.data);
2403 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2404 o_free_unsafe(&dest);
2408 #if ENABLE_SH_MATH_SUPPORT
2409 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
2411 arith_eval_hooks_t hooks;
2415 hooks.lookupvar = get_local_var_value;
2416 hooks.setvar = set_local_var_from_halves;
2417 hooks.endofname = endofname;
2418 exp_str = expand_pseudo_dquoted(arg);
2419 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
2425 /* Expand all variable references in given string, adding words to list[]
2426 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2427 * to be filled). This routine is extremely tricky: has to deal with
2428 * variables/parameters with whitespace, $* and $@, and constructs like
2429 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2430 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2432 /* or_mask is either 0 (normal case) or 0x80 -
2433 * expansion of right-hand side of assignment == 1-element expand.
2434 * It will also do no globbing, and thus we must not backslash-quote!
2441 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2442 debug_print_list("expand_vars_to_list", output, n);
2443 n = o_save_ptr(output, n);
2444 debug_print_list("expand_vars_to_list[0]", output, n);
2446 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2449 char *to_be_freed = NULL;
2450 const char *val = NULL;
2451 #if ENABLE_HUSH_TICK
2452 o_string subst_result = NULL_O_STRING;
2454 #if ENABLE_SH_MATH_SUPPORT
2455 char arith_buf[sizeof(arith_t)*3 + 2];
2457 o_addblock(output, arg, p - arg);
2458 debug_print_list("expand_vars_to_list[1]", output, n);
2460 p = strchr(p, SPECIAL_VAR_SYMBOL);
2462 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2463 /* "$@" is special. Even if quoted, it can still
2464 * expand to nothing (not even an empty string) */
2465 if ((first_ch & 0x7f) != '@')
2466 ored_ch |= first_ch;
2468 switch (first_ch & 0x7f) {
2469 /* Highest bit in first_ch indicates that var is double-quoted */
2471 val = utoa(G.root_pid);
2473 case '!': /* bg pid */
2474 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2476 case '?': /* exitcode */
2477 val = utoa(G.last_exitcode);
2479 case '#': /* argc */
2480 if (arg[1] != SPECIAL_VAR_SYMBOL)
2481 /* actually, it's a ${#var} */
2483 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2488 if (!G.global_argv[i])
2490 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2491 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2492 smallint sv = output->o_escape;
2493 /* unquoted var's contents should be globbed, so don't escape */
2494 output->o_escape = 0;
2495 while (G.global_argv[i]) {
2496 n = expand_on_ifs(output, n, G.global_argv[i]);
2497 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2498 if (G.global_argv[i++][0] && G.global_argv[i]) {
2499 /* this argv[] is not empty and not last:
2500 * put terminating NUL, start new word */
2501 o_addchr(output, '\0');
2502 debug_print_list("expand_vars_to_list[2]", output, n);
2503 n = o_save_ptr(output, n);
2504 debug_print_list("expand_vars_to_list[3]", output, n);
2507 output->o_escape = sv;
2509 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2510 * and in this case should treat it like '$*' - see 'else...' below */
2511 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2513 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2514 if (++i >= G.global_argc)
2516 o_addchr(output, '\0');
2517 debug_print_list("expand_vars_to_list[4]", output, n);
2518 n = o_save_ptr(output, n);
2520 } else { /* quoted $*: add as one word */
2522 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2523 if (!G.global_argv[++i])
2526 o_addchr(output, G.ifs[0]);
2530 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2531 /* "Empty variable", used to make "" etc to not disappear */
2535 #if ENABLE_HUSH_TICK
2536 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2539 /* Can't just stuff it into output o_string,
2540 * expanded result may need to be globbed
2541 * and $IFS-splitted */
2542 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2543 G.last_exitcode = process_command_subs(&subst_result, arg);
2544 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2545 val = subst_result.data;
2548 #if ENABLE_SH_MATH_SUPPORT
2549 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2553 arg++; /* skip '+' */
2554 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2555 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2556 res = expand_and_evaluate_arith(arg, &errcode);
2559 const char *msg = "error in arithmetic";
2562 msg = "exponent less than 0";
2565 msg = "divide by 0";
2568 msg = "expression recursion loop detected";
2573 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2574 sprintf(arith_buf, arith_t_fmt, res);
2579 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2582 char exp_len; /* '#' if it's ${#var} */
2584 char exp_save = exp_save; /* for compiler */
2585 char *exp_saveptr = exp_saveptr; /* points to expansion operator */
2586 char *exp_word = exp_word; /* for compiler */
2589 arg[0] = first_ch & 0x7f;
2591 /* prepare for expansions */
2594 if (exp_len == '#') {
2595 /* handle length expansion ${#var} */
2598 /* maybe handle parameter expansion */
2599 exp_saveptr = var + strcspn(var, "%#:-=+?");
2600 exp_save = *exp_saveptr;
2602 exp_word = exp_saveptr;
2603 if (exp_save == ':')
2605 exp_op = *exp_word++;
2606 *exp_saveptr = '\0';
2610 /* lookup the variable in question */
2611 if (isdigit(var[0])) {
2612 /* handle_dollar() should have vetted var for us */
2614 if (i < G.global_argc)
2615 val = G.global_argv[i];
2616 /* else val remains NULL: $N with too big N */
2618 val = get_local_var_value(var);
2620 /* handle any expansions */
2621 if (exp_len == '#') {
2622 debug_printf_expand("expand: length(%s)=", val);
2623 val = utoa(val ? strlen(val) : 0);
2624 debug_printf_expand("%s\n", val);
2625 } else if (exp_op) {
2626 if (exp_op == '%' || exp_op == '#') {
2627 /* Standard-mandated substring removal ops:
2628 * ${parameter%word} - remove smallest suffix pattern
2629 * ${parameter%%word} - remove largest suffix pattern
2630 * ${parameter#word} - remove smallest prefix pattern
2631 * ${parameter##word} - remove largest prefix pattern
2633 * Word is expanded to produce a glob pattern.
2634 * Then var's value is matched to it and matching part removed.
2639 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2640 if (exp_op == *exp_word) /* ## or %% */
2642 val = to_be_freed = xstrdup(val);
2644 char *exp_exp_word = expand_pseudo_dquoted(exp_word);
2646 exp_word = exp_exp_word;
2647 loc = scan(to_be_freed, exp_word, match_at_left);
2648 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
2649 // exp_op, to_be_freed, exp_word, loc);
2652 if (loc) { /* match was found */
2653 if (match_at_left) /* # or ## */
2659 } else if (!strchr("%#:-=+?"+3, exp_op)) {
2660 #if ENABLE_HUSH_BASH_COMPAT
2661 /* exp_op is ':' and next char isn't a subst operator.
2662 * Assuming it's ${var:[N][:M]} bashism.
2663 * TODO: N, M can be expressions similar to $((EXPR)): 2+2, 2+var etc
2666 unsigned len = INT_MAX;
2669 if (*exp_word != ':') /* not ${var::...} */
2670 beg = bb_strtou(exp_word, &end, 0);
2671 //bb_error_msg("beg:'%s'=%u end:'%s'", exp_word, beg, end);
2673 if (end[1] != '\0') /* not ${var:NUM:} */
2674 len = bb_strtou(end + 1, &end, 0);
2679 //bb_error_msg("len:%u end:'%s'", len, end);
2682 //bb_error_msg("from val:'%s'", val);
2683 if (len == 0 || !val || beg >= strlen(val))
2686 val = to_be_freed = xstrndup(val + beg, len);
2687 //bb_error_msg("val:'%s'", val);
2691 die_if_script("malformed ${%s...}", var);
2694 } else { /* one of "-=+?" */
2695 /* Standard-mandated substitution ops:
2696 * ${var?word} - indicate error if unset
2697 * If var is unset, word (or a message indicating it is unset
2698 * if word is null) is written to standard error
2699 * and the shell exits with a non-zero exit status.
2700 * Otherwise, the value of var is substituted.
2701 * ${var-word} - use default value
2702 * If var is unset, word is substituted.
2703 * ${var=word} - assign and use default value
2704 * If var is unset, word is assigned to var.
2705 * In all cases, final value of var is substituted.
2706 * ${var+word} - use alternative value
2707 * If var is unset, null is substituted.
2708 * Otherwise, word is substituted.
2710 * Word is subjected to tilde expansion, parameter expansion,
2711 * command substitution, and arithmetic expansion.
2712 * If word is not needed, it is not expanded.
2714 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2715 * but also treat null var as if it is unset.
2717 int use_word = (!val || ((exp_save == ':') && !val[0]));
2719 use_word = !use_word;
2720 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2721 (exp_save == ':') ? "true" : "false", use_word);
2723 to_be_freed = expand_pseudo_dquoted(exp_word);
2725 exp_word = to_be_freed;
2726 if (exp_op == '?') {
2727 /* mimic bash message */
2728 die_if_script("%s: %s",
2730 exp_word[0] ? exp_word : "parameter null or not set"
2732 //TODO: how interactive bash aborts expansion mid-command?
2737 if (exp_op == '=') {
2738 /* ${var=[word]} or ${var:=[word]} */
2739 if (isdigit(var[0]) || var[0] == '#') {
2740 /* mimic bash message */
2741 die_if_script("$%s: cannot assign in this way", var);
2744 char *new_var = xasprintf("%s=%s", var, val);
2745 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2751 *exp_saveptr = exp_save;
2755 #if ENABLE_HUSH_TICK
2758 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2759 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2761 /* unquoted var's contents should be globbed, so don't escape */
2762 smallint sv = output->o_escape;
2763 output->o_escape = 0;
2764 n = expand_on_ifs(output, n, val);
2766 output->o_escape = sv;
2768 } else { /* quoted $VAR, val will be appended below */
2769 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2772 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2775 o_addQstr(output, val, strlen(val));
2778 /* Do the check to avoid writing to a const string */
2779 if (*p != SPECIAL_VAR_SYMBOL)
2780 *p = SPECIAL_VAR_SYMBOL;
2782 #if ENABLE_HUSH_TICK
2783 o_free(&subst_result);
2786 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2789 debug_print_list("expand_vars_to_list[a]", output, n);
2790 /* this part is literal, and it was already pre-quoted
2791 * if needed (much earlier), do not use o_addQstr here! */
2792 o_addstr_with_NUL(output, arg);
2793 debug_print_list("expand_vars_to_list[b]", output, n);
2794 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2795 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2798 /* allow to reuse list[n] later without re-growth */
2799 output->has_empty_slot = 1;
2801 o_addchr(output, '\0');
2806 static char **expand_variables(char **argv, int or_mask)
2811 o_string output = NULL_O_STRING;
2813 if (or_mask & 0x100) {
2814 output.o_escape = 1; /* protect against globbing for "$var" */
2815 /* (unquoted $var will temporarily switch it off) */
2822 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2825 debug_print_list("expand_variables", &output, n);
2827 /* output.data (malloced in one block) gets returned in "list" */
2828 list = o_finalize_list(&output, n);
2829 debug_print_strings("expand_variables[1]", list);
2833 static char **expand_strvec_to_strvec(char **argv)
2835 return expand_variables(argv, 0x100);
2838 #if ENABLE_HUSH_BASH_COMPAT
2839 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2841 return expand_variables(argv, 0x80);
2845 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2846 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2851 o_string output = NULL_O_STRING;
2856 int is_var = is_well_formed_var_name(*v, '=');
2857 /* is_var * 0x80: singleword expansion for vars */
2858 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2860 /* Subtle! expand_vars_to_list did not glob last word yet.
2861 * It does this only when fed with further data.
2862 * Therefore we set globbing flags AFTER it, not before:
2865 /* if it is not recognizably abc=...; then: */
2866 output.o_escape = !is_var; /* protect against globbing for "$var" */
2867 /* (unquoted $var will temporarily switch it off) */
2868 output.o_glob = !is_var; /* and indeed do globbing */
2871 debug_print_list("expand_cond", &output, n);
2873 /* output.data (malloced in one block) gets returned in "list" */
2874 list = o_finalize_list(&output, n);
2875 debug_print_strings("expand_cond[1]", list);
2880 /* Used for expansion of right hand of assignments */
2881 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2883 static char *expand_string_to_string(const char *str)
2885 char *argv[2], **list;
2887 argv[0] = (char*)str;
2889 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2891 if (!list[0] || list[1])
2892 bb_error_msg_and_die("BUG in varexp2");
2893 /* actually, just move string 2*sizeof(char*) bytes back */
2894 overlapping_strcpy((char*)list, list[0]);
2895 unbackslash((char*)list);
2896 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2900 /* Used for "eval" builtin */
2901 static char* expand_strvec_to_string(char **argv)
2905 list = expand_variables(argv, 0x80);
2906 /* Convert all NULs to spaces */
2911 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2912 bb_error_msg_and_die("BUG in varexp3");
2913 /* bash uses ' ' regardless of $IFS contents */
2918 overlapping_strcpy((char*)list, list[0]);
2919 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2923 static char **expand_assignments(char **argv, int count)
2927 /* Expand assignments into one string each */
2928 for (i = 0; i < count; i++) {
2929 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2937 void re_execute_shell(char ***to_free, const char *s,
2938 char *g_argv0, char **g_argv,
2939 char **builtin_argv) NORETURN;
2941 static void reset_traps_to_defaults(void)
2943 /* This function is always called in a child shell
2944 * after fork (not vfork, NOMMU doesn't use this function).
2949 /* Child shells are not interactive.
2950 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2951 * Testcase: (while :; do :; done) + ^Z should background.
2952 * Same goes for SIGTERM, SIGHUP, SIGINT.
2954 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2955 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2957 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2958 * Stupid. It can be done with *single* &= op, but we can't use
2959 * the fact that G.blocked_set is implemented as a bitmask
2961 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2965 /* Careful. Only if no trap or trap is not "" */
2966 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2967 sigdelset(&G.blocked_set, sig);
2974 /* Our homegrown sig mask is saner to work with :) */
2975 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2977 /* Resetting all traps to default except empty ones */
2978 mask = G.non_DFL_mask;
2979 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2980 if (!G.traps[sig] || !G.traps[sig][0])
2983 G.traps[sig] = NULL;
2984 /* There is no signal for 0 (EXIT) */
2987 /* There was a trap handler, we just removed it.
2988 * But if sig still has non-DFL handling,
2989 * we should not unblock the sig. */
2992 sigdelset(&G.blocked_set, sig);
2994 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2999 static void re_execute_shell(char ***to_free, const char *s,
3000 char *g_argv0, char **g_argv,
3001 char **builtin_argv) NORETURN;
3002 static void re_execute_shell(char ***to_free, const char *s,
3003 char *g_argv0, char **g_argv,
3004 char **builtin_argv)
3006 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
3007 /* delims + 2 * (number of bytes in printed hex numbers) */
3008 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
3009 char *heredoc_argv[4];
3010 struct variable *cur;
3011 # if ENABLE_HUSH_FUNCTIONS
3012 struct function *funcp;
3016 unsigned long long empty_trap_mask;
3018 if (!g_argv0) { /* heredoc */
3019 argv = heredoc_argv;
3020 argv[0] = (char *) G.argv0_for_re_execing;
3021 argv[1] = (char *) "-<";
3022 argv[2] = (char *) s;
3024 pp = &argv[3]; /* used as pointer to empty environment */
3030 if (pp) while (*pp++)
3033 empty_trap_mask = 0;
3036 for (sig = 1; sig < NSIG; sig++) {
3037 if (G.traps[sig] && !G.traps[sig][0])
3038 empty_trap_mask |= 1LL << sig;
3042 sprintf(param_buf, NOMMU_HACK_FMT
3043 , (unsigned) G.root_pid
3044 , (unsigned) G.root_ppid
3045 , (unsigned) G.last_bg_pid
3046 , (unsigned) G.last_exitcode
3049 IF_HUSH_LOOPS(, G.depth_of_loop)
3051 #undef NOMMU_HACK_FMT
3052 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3053 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3056 for (cur = G.top_var; cur; cur = cur->next) {
3057 if (!cur->flg_export || cur->flg_read_only)
3060 # if ENABLE_HUSH_FUNCTIONS
3061 for (funcp = G.top_func; funcp; funcp = funcp->next)
3067 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3068 *pp++ = (char *) G.argv0_for_re_execing;
3070 for (cur = G.top_var; cur; cur = cur->next) {
3071 if (cur->varstr == hush_version_str)
3073 if (cur->flg_read_only) {
3074 *pp++ = (char *) "-R";
3075 *pp++ = cur->varstr;
3076 } else if (!cur->flg_export) {
3077 *pp++ = (char *) "-V";
3078 *pp++ = cur->varstr;
3081 # if ENABLE_HUSH_FUNCTIONS
3082 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3083 *pp++ = (char *) "-F";
3084 *pp++ = funcp->name;
3085 *pp++ = funcp->body_as_string;
3088 /* We can pass activated traps here. Say, -Tnn:trap_string
3090 * However, POSIX says that subshells reset signals with traps
3092 * I tested bash-3.2 and it not only does that with true subshells
3093 * of the form ( list ), but with any forked children shells.
3094 * I set trap "echo W" WINCH; and then tried:
3096 * { echo 1; sleep 20; echo 2; } &
3097 * while true; do echo 1; sleep 20; echo 2; break; done &
3098 * true | { echo 1; sleep 20; echo 2; } | cat
3100 * In all these cases sending SIGWINCH to the child shell
3101 * did not run the trap. If I add trap "echo V" WINCH;
3102 * _inside_ group (just before echo 1), it works.
3104 * I conclude it means we don't need to pass active traps here.
3105 * Even if we would use signal handlers instead of signal masking
3106 * in order to implement trap handling,
3107 * exec syscall below resets signals to SIG_DFL for us.
3109 *pp++ = (char *) "-c";
3112 while (*++builtin_argv)
3113 *pp++ = *builtin_argv;
3114 *pp++ = (char *) "";
3119 /* *pp = NULL; - is already there */
3123 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3124 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3125 execve(bb_busybox_exec_path, argv, pp);
3126 /* Fallback. Useful for init=/bin/hush usage etc */
3127 if (argv[0][0] == '/')
3128 execve(argv[0], argv, pp);
3129 xfunc_error_retval = 127;
3130 bb_error_msg_and_die("can't re-execute the shell");
3132 #endif /* !BB_MMU */
3135 static void setup_heredoc(struct redir_struct *redir)
3137 struct fd_pair pair;
3140 /* the _body_ of heredoc (misleading field name) */
3141 const char *heredoc = redir->rd_filename;
3148 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3149 expanded = expand_pseudo_dquoted(heredoc);
3153 len = strlen(heredoc);
3155 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3157 xmove_fd(pair.rd, redir->rd_fd);
3159 /* Try writing without forking. Newer kernels have
3160 * dynamically growing pipes. Must use non-blocking write! */
3163 written = write(pair.wr, heredoc, len);
3174 ndelay_off(pair.wr);
3176 /* Okay, pipe buffer was not big enough */
3177 /* Note: we must not create a stray child (bastard? :)
3178 * for the unsuspecting parent process. Child creates a grandchild
3179 * and exits before parent execs the process which consumes heredoc
3180 * (that exec happens after we return from this function) */
3186 bb_perror_msg_and_die("vfork");
3189 disable_restore_tty_pgrp_on_exit();
3190 pid = BB_MMU ? fork() : vfork();
3192 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3196 close(redir->rd_fd); /* read side of the pipe */
3198 full_write(pair.wr, heredoc, len); /* may loop or block */
3201 /* Delegate blocking writes to another process */
3202 xmove_fd(pair.wr, STDOUT_FILENO);
3203 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3207 #if ENABLE_HUSH_FAST
3209 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3211 enable_restore_tty_pgrp_on_exit();
3217 wait(NULL); /* wait till child has died */
3220 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3221 * and stderr if they are redirected. */
3222 static int setup_redirects(struct command *prog, int squirrel[])
3225 struct redir_struct *redir;
3227 for (redir = prog->redirects; redir; redir = redir->next) {
3228 if (redir->rd_type == REDIRECT_HEREDOC2) {
3229 /* rd_fd<<HERE case */
3230 if (squirrel && redir->rd_fd < 3
3231 && squirrel[redir->rd_fd] < 0
3233 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3235 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3237 debug_printf_parse("set heredoc '%s'\n",
3238 redir->rd_filename);
3239 setup_heredoc(redir);
3243 if (redir->rd_dup == REDIRFD_TO_FILE) {
3244 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3246 if (redir->rd_filename == NULL) {
3247 /* Something went wrong in the parse.
3248 * Pretend it didn't happen */
3249 bb_error_msg("bug in redirect parse");
3252 mode = redir_table[redir->rd_type].mode;
3253 p = expand_string_to_string(redir->rd_filename);
3254 openfd = open_or_warn(p, mode);
3257 /* this could get lost if stderr has been redirected, but
3258 * bash and ash both lose it as well (though zsh doesn't!) */
3259 //what the above comment tries to say?
3263 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3264 openfd = redir->rd_dup;
3267 if (openfd != redir->rd_fd) {
3268 if (squirrel && redir->rd_fd < 3
3269 && squirrel[redir->rd_fd] < 0
3271 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3273 if (openfd == REDIRFD_CLOSE) {
3274 /* "n>-" means "close me" */
3275 close(redir->rd_fd);
3277 xdup2(openfd, redir->rd_fd);
3278 if (redir->rd_dup == REDIRFD_TO_FILE)
3286 static void restore_redirects(int squirrel[])
3289 for (i = 0; i < 3; i++) {
3292 /* We simply die on error */
3299 static void free_pipe_list(struct pipe *head);
3301 /* Return code is the exit status of the pipe */
3302 static void free_pipe(struct pipe *pi)
3305 struct command *command;
3306 struct redir_struct *r, *rnext;
3309 if (pi->stopped_cmds > 0) /* why? */
3311 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3312 for (i = 0; i < pi->num_cmds; i++) {
3313 command = &pi->cmds[i];
3314 debug_printf_clean(" command %d:\n", i);
3315 if (command->argv) {
3316 for (a = 0, p = command->argv; *p; a++, p++) {
3317 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3319 free_strings(command->argv);
3320 command->argv = NULL;
3322 /* not "else if": on syntax error, we may have both! */
3323 if (command->group) {
3324 debug_printf_clean(" begin group (cmd_type:%d)\n",
3326 free_pipe_list(command->group);
3327 debug_printf_clean(" end group\n");
3328 command->group = NULL;
3330 /* else is crucial here.
3331 * If group != NULL, child_func is meaningless */
3332 #if ENABLE_HUSH_FUNCTIONS
3333 else if (command->child_func) {
3334 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3335 command->child_func->parent_cmd = NULL;
3339 free(command->group_as_string);
3340 command->group_as_string = NULL;
3342 for (r = command->redirects; r; r = rnext) {
3343 debug_printf_clean(" redirect %d%s",
3344 r->rd_fd, redir_table[r->rd_type].descrip);
3345 /* guard against the case >$FOO, where foo is unset or blank */
3346 if (r->rd_filename) {
3347 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3348 free(r->rd_filename);
3349 r->rd_filename = NULL;
3351 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3355 command->redirects = NULL;
3357 free(pi->cmds); /* children are an array, they get freed all at once */
3365 static void free_pipe_list(struct pipe *head)
3367 struct pipe *pi, *next;
3369 for (pi = head; pi; pi = next) {
3371 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3374 debug_printf_clean("pipe followup code %d\n", pi->followup);
3376 /*pi->next = NULL;*/
3382 static int run_list(struct pipe *pi);
3384 #define parse_stream(pstring, input, end_trigger) \
3385 parse_stream(input, end_trigger)
3387 static struct pipe *parse_stream(char **pstring,
3388 struct in_str *input,
3390 static void parse_and_run_string(const char *s);
3393 static char *find_in_path(const char *arg)
3396 const char *PATH = get_local_var_value("PATH");
3402 const char *end = strchrnul(PATH, ':');
3403 int sz = end - PATH; /* must be int! */
3407 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3409 /* We have xxx::yyyy in $PATH,
3410 * it means "use current dir" */
3413 if (access(ret, F_OK) == 0)
3426 static const struct built_in_command* find_builtin_helper(const char *name,
3427 const struct built_in_command *x,
3428 const struct built_in_command *end)
3431 if (strcmp(name, x->b_cmd) != 0) {
3435 debug_printf_exec("found builtin '%s'\n", name);
3440 static const struct built_in_command* find_builtin1(const char *name)
3442 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3444 static const struct built_in_command* find_builtin(const char *name)
3446 const struct built_in_command *x = find_builtin1(name);
3449 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3452 #if ENABLE_HUSH_FUNCTIONS
3453 static struct function **find_function_slot(const char *name)
3455 struct function **funcpp = &G.top_func;
3457 if (strcmp(name, (*funcpp)->name) == 0) {
3460 funcpp = &(*funcpp)->next;
3465 static const struct function *find_function(const char *name)
3467 const struct function *funcp = *find_function_slot(name);
3469 debug_printf_exec("found function '%s'\n", name);
3473 /* Note: takes ownership on name ptr */
3474 static struct function *new_function(char *name)
3476 struct function **funcpp = find_function_slot(name);
3477 struct function *funcp = *funcpp;
3479 if (funcp != NULL) {
3480 struct command *cmd = funcp->parent_cmd;
3481 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3483 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3485 /* Note: if !funcp->body, do not free body_as_string!
3486 * This is a special case of "-F name body" function:
3487 * body_as_string was not malloced! */
3489 free_pipe_list(funcp->body);
3491 free(funcp->body_as_string);
3495 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3496 cmd->argv[0] = funcp->name;
3497 cmd->group = funcp->body;
3499 cmd->group_as_string = funcp->body_as_string;
3503 debug_printf_exec("remembering new function '%s'\n", name);
3504 funcp = *funcpp = xzalloc(sizeof(*funcp));
3505 /*funcp->next = NULL;*/
3512 static void unset_func(const char *name)
3514 struct function **funcpp = find_function_slot(name);
3515 struct function *funcp = *funcpp;
3517 if (funcp != NULL) {
3518 debug_printf_exec("freeing function '%s'\n", funcp->name);
3519 *funcpp = funcp->next;
3520 /* funcp is unlinked now, deleting it.
3521 * Note: if !funcp->body, the function was created by
3522 * "-F name body", do not free ->body_as_string
3523 * and ->name as they were not malloced. */
3525 free_pipe_list(funcp->body);
3528 free(funcp->body_as_string);
3536 #define exec_function(to_free, funcp, argv) \
3537 exec_function(funcp, argv)
3539 static void exec_function(char ***to_free,
3540 const struct function *funcp,
3541 char **argv) NORETURN;
3542 static void exec_function(char ***to_free,
3543 const struct function *funcp,
3549 argv[0] = G.global_argv[0];
3550 G.global_argv = argv;
3554 /* On MMU, funcp->body is always non-NULL */
3555 n = run_list(funcp->body);
3559 re_execute_shell(to_free,
3560 funcp->body_as_string,
3567 static int run_function(const struct function *funcp, char **argv)
3573 save_and_replace_G_args(&sv, argv);
3575 /* "we are in function, ok to use return" */
3576 sv_flg = G.flag_return_in_progress;
3577 G.flag_return_in_progress = -1;
3578 # if ENABLE_HUSH_LOCAL
3579 G.func_nest_level++;
3582 /* On MMU, funcp->body is always non-NULL */
3585 /* Function defined by -F */
3586 parse_and_run_string(funcp->body_as_string);
3587 rc = G.last_exitcode;
3591 rc = run_list(funcp->body);
3594 # if ENABLE_HUSH_LOCAL
3596 struct variable *var;
3597 struct variable **var_pp;
3599 var_pp = &G.top_var;
3600 while ((var = *var_pp) != NULL) {
3601 if (var->func_nest_level < G.func_nest_level) {
3602 var_pp = &var->next;
3606 if (var->flg_export)
3607 bb_unsetenv(var->varstr);
3608 /* Remove from global list */
3609 *var_pp = var->next;
3615 G.func_nest_level--;
3618 G.flag_return_in_progress = sv_flg;
3620 restore_G_args(&sv, argv);
3624 #endif /* ENABLE_HUSH_FUNCTIONS */
3628 #define exec_builtin(to_free, x, argv) \
3629 exec_builtin(x, argv)
3631 #define exec_builtin(to_free, x, argv) \
3632 exec_builtin(to_free, argv)
3634 static void exec_builtin(char ***to_free,
3635 const struct built_in_command *x,
3636 char **argv) NORETURN;
3637 static void exec_builtin(char ***to_free,
3638 const struct built_in_command *x,
3642 int rcode = x->b_function(argv);
3646 /* On NOMMU, we must never block!
3647 * Example: { sleep 99 | read line; } & echo Ok
3649 re_execute_shell(to_free,
3658 static void execvp_or_die(char **argv) NORETURN;
3659 static void execvp_or_die(char **argv)
3661 debug_printf_exec("execing '%s'\n", argv[0]);
3662 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3663 execvp(argv[0], argv);
3664 bb_perror_msg("can't execute '%s'", argv[0]);
3665 _exit(127); /* bash compat */
3669 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3670 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3671 #define pseudo_exec(nommu_save, command, argv_expanded) \
3672 pseudo_exec(command, argv_expanded)
3675 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3677 * Don't exit() here. If you don't exec, use _exit instead.
3678 * The at_exit handlers apparently confuse the calling process,
3679 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3680 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3681 char **argv, int assignment_cnt,
3682 char **argv_expanded) NORETURN;
3683 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3684 char **argv, int assignment_cnt,
3685 char **argv_expanded)
3689 /* Case when we are here: ... | var=val | ... */
3690 if (!argv[assignment_cnt])
3691 _exit(EXIT_SUCCESS);
3693 new_env = expand_assignments(argv, assignment_cnt);
3695 set_vars_and_save_old(new_env);
3696 free(new_env); /* optional */
3697 /* we can also destroy set_vars_and_save_old's return value,
3700 nommu_save->new_env = new_env;
3701 nommu_save->old_vars = set_vars_and_save_old(new_env);
3703 if (argv_expanded) {
3704 argv = argv_expanded;
3706 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3708 nommu_save->argv = argv;
3712 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3713 if (strchr(argv[0], '/') != NULL)
3717 /* Check if the command matches any of the builtins.
3718 * Depending on context, this might be redundant. But it's
3719 * easier to waste a few CPU cycles than it is to figure out
3720 * if this is one of those cases.
3723 /* On NOMMU, it is more expensive to re-execute shell
3724 * just in order to run echo or test builtin.
3725 * It's better to skip it here and run corresponding
3726 * non-builtin later. */
3727 const struct built_in_command *x;
3728 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3730 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3733 #if ENABLE_HUSH_FUNCTIONS
3734 /* Check if the command matches any functions */
3736 const struct function *funcp = find_function(argv[0]);
3738 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3743 #if ENABLE_FEATURE_SH_STANDALONE
3744 /* Check if the command matches any busybox applets */
3746 int a = find_applet_by_name(argv[0]);
3748 # if BB_MMU /* see above why on NOMMU it is not allowed */
3749 if (APPLET_IS_NOEXEC(a)) {
3750 debug_printf_exec("running applet '%s'\n", argv[0]);
3751 run_applet_no_and_exit(a, argv);
3754 /* Re-exec ourselves */
3755 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3756 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3757 execv(bb_busybox_exec_path, argv);
3758 /* If they called chroot or otherwise made the binary no longer
3759 * executable, fall through */
3764 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3767 execvp_or_die(argv);
3770 /* Called after [v]fork() in run_pipe
3772 static void pseudo_exec(nommu_save_t *nommu_save,
3773 struct command *command,
3774 char **argv_expanded) NORETURN;
3775 static void pseudo_exec(nommu_save_t *nommu_save,
3776 struct command *command,
3777 char **argv_expanded)
3779 if (command->argv) {
3780 pseudo_exec_argv(nommu_save, command->argv,
3781 command->assignment_cnt, argv_expanded);
3784 if (command->group) {
3785 /* Cases when we are here:
3788 * ... | ( list ) | ...
3789 * ... | { list } | ...
3793 debug_printf_exec("pseudo_exec: run_list\n");
3794 reset_traps_to_defaults();
3795 rcode = run_list(command->group);
3796 /* OK to leak memory by not calling free_pipe_list,
3797 * since this process is about to exit */
3800 re_execute_shell(&nommu_save->argv_from_re_execing,
3801 command->group_as_string,
3808 /* Case when we are here: ... | >file */
3809 debug_printf_exec("pseudo_exec'ed null command\n");
3810 _exit(EXIT_SUCCESS);
3814 static const char *get_cmdtext(struct pipe *pi)
3820 /* This is subtle. ->cmdtext is created only on first backgrounding.
3821 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3822 * On subsequent bg argv is trashed, but we won't use it */
3825 argv = pi->cmds[0].argv;
3826 if (!argv || !argv[0]) {
3827 pi->cmdtext = xzalloc(1);
3833 len += strlen(*argv) + 1;
3837 argv = pi->cmds[0].argv;
3839 len = strlen(*argv);
3840 memcpy(p, *argv, len);
3848 static void insert_bg_job(struct pipe *pi)
3850 struct pipe *job, **jobp;
3853 /* Linear search for the ID of the job to use */
3855 for (job = G.job_list; job; job = job->next)
3856 if (job->jobid >= pi->jobid)
3857 pi->jobid = job->jobid + 1;
3859 /* Add job to the list of running jobs */
3861 while ((job = *jobp) != NULL)
3863 job = *jobp = xmalloc(sizeof(*job));
3865 *job = *pi; /* physical copy */
3867 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3868 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3869 for (i = 0; i < pi->num_cmds; i++) {
3870 job->cmds[i].pid = pi->cmds[i].pid;
3871 /* all other fields are not used and stay zero */
3873 job->cmdtext = xstrdup(get_cmdtext(pi));
3875 if (G_interactive_fd)
3876 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3877 /* Last command's pid goes to $! */
3878 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3879 G.last_jobid = job->jobid;
3882 static void remove_bg_job(struct pipe *pi)
3884 struct pipe *prev_pipe;
3886 if (pi == G.job_list) {
3887 G.job_list = pi->next;
3889 prev_pipe = G.job_list;
3890 while (prev_pipe->next != pi)
3891 prev_pipe = prev_pipe->next;
3892 prev_pipe->next = pi->next;
3895 G.last_jobid = G.job_list->jobid;
3900 /* Remove a backgrounded job */
3901 static void delete_finished_bg_job(struct pipe *pi)
3904 pi->stopped_cmds = 0;
3910 /* Check to see if any processes have exited -- if they
3911 * have, figure out why and see if a job has completed */
3912 static int checkjobs(struct pipe* fg_pipe)
3922 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3924 attributes = WUNTRACED;
3925 if (fg_pipe == NULL)
3926 attributes |= WNOHANG;
3929 #if ENABLE_HUSH_FAST
3930 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3931 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3932 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3933 /* There was neither fork nor SIGCHLD since last waitpid */
3934 /* Avoid doing waitpid syscall if possible */
3935 if (!G.we_have_children) {
3939 if (fg_pipe == NULL) { /* is WNOHANG set? */
3940 /* We have children, but they did not exit
3941 * or stop yet (we saw no SIGCHLD) */
3944 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3948 /* Do we do this right?
3949 * bash-3.00# sleep 20 | false
3951 * [3]+ Stopped sleep 20 | false
3952 * bash-3.00# echo $?
3953 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3954 * [hush 1.14.0: yes we do it right]
3961 #if ENABLE_HUSH_FAST
3962 i = G.count_SIGCHLD;
3964 childpid = waitpid(-1, &status, attributes);
3965 if (childpid <= 0) {
3966 if (childpid && errno != ECHILD)
3967 bb_perror_msg("waitpid");
3968 #if ENABLE_HUSH_FAST
3969 else { /* Until next SIGCHLD, waitpid's are useless */
3970 G.we_have_children = (childpid == 0);
3971 G.handled_SIGCHLD = i;
3972 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3977 dead = WIFEXITED(status) || WIFSIGNALED(status);
3980 if (WIFSTOPPED(status))
3981 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3982 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3983 if (WIFSIGNALED(status))
3984 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3985 childpid, WTERMSIG(status), WEXITSTATUS(status));
3986 if (WIFEXITED(status))
3987 debug_printf_jobs("pid %d exited, exitcode %d\n",
3988 childpid, WEXITSTATUS(status));
3990 /* Were we asked to wait for fg pipe? */
3992 for (i = 0; i < fg_pipe->num_cmds; i++) {
3993 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3994 if (fg_pipe->cmds[i].pid != childpid)
3997 fg_pipe->cmds[i].pid = 0;
3998 fg_pipe->alive_cmds--;
3999 if (i == fg_pipe->num_cmds - 1) {
4000 /* last process gives overall exitstatus */
4001 rcode = WEXITSTATUS(status);
4002 /* bash prints killer signal's name for *last*
4003 * process in pipe (prints just newline for SIGINT).
4004 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
4006 if (WIFSIGNALED(status)) {
4007 int sig = WTERMSIG(status);
4008 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
4009 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
4010 * Maybe we need to use sig | 128? */
4013 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
4016 fg_pipe->cmds[i].is_stopped = 1;
4017 fg_pipe->stopped_cmds++;
4019 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
4020 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
4021 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
4022 /* All processes in fg pipe have exited or stopped */
4023 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4024 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4025 * and "killall -STOP cat" */
4026 if (G_interactive_fd) {
4028 if (fg_pipe->alive_cmds)
4029 insert_bg_job(fg_pipe);
4033 if (!fg_pipe->alive_cmds)
4036 /* There are still running processes in the fg pipe */
4037 goto wait_more; /* do waitpid again */
4039 /* it wasnt fg_pipe, look for process in bg pipes */
4043 /* We asked to wait for bg or orphaned children */
4044 /* No need to remember exitcode in this case */
4045 for (pi = G.job_list; pi; pi = pi->next) {
4046 for (i = 0; i < pi->num_cmds; i++) {
4047 if (pi->cmds[i].pid == childpid)
4048 goto found_pi_and_prognum;
4051 /* Happens when shell is used as init process (init=/bin/sh) */
4052 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4053 continue; /* do waitpid again */
4055 found_pi_and_prognum:
4058 pi->cmds[i].pid = 0;
4060 if (!pi->alive_cmds) {
4061 if (G_interactive_fd)
4062 printf(JOB_STATUS_FORMAT, pi->jobid,
4063 "Done", pi->cmdtext);
4064 delete_finished_bg_job(pi);
4068 pi->cmds[i].is_stopped = 1;
4072 } /* while (waitpid succeeds)... */
4078 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4081 int rcode = checkjobs(fg_pipe);
4082 if (G_saved_tty_pgrp) {
4083 /* Job finished, move the shell to the foreground */
4084 p = getpgrp(); /* our process group id */
4085 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4086 tcsetpgrp(G_interactive_fd, p);
4092 /* Start all the jobs, but don't wait for anything to finish.
4095 * Return code is normally -1, when the caller has to wait for children
4096 * to finish to determine the exit status of the pipe. If the pipe
4097 * is a simple builtin command, however, the action is done by the
4098 * time run_pipe returns, and the exit code is provided as the
4101 * Returns -1 only if started some children. IOW: we have to
4102 * mask out retvals of builtins etc with 0xff!
4104 * The only case when we do not need to [v]fork is when the pipe
4105 * is single, non-backgrounded, non-subshell command. Examples:
4106 * cmd ; ... { list } ; ...
4107 * cmd && ... { list } && ...
4108 * cmd || ... { list } || ...
4109 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4110 * or (if SH_STANDALONE) an applet, and we can run the { list }
4111 * with run_list. If it isn't one of these, we fork and exec cmd.
4113 * Cases when we must fork:
4114 * non-single: cmd | cmd
4115 * backgrounded: cmd & { list } &
4116 * subshell: ( list ) [&]
4118 static NOINLINE int run_pipe(struct pipe *pi)
4120 static const char *const null_ptr = NULL;
4123 struct command *command;
4124 char **argv_expanded;
4127 /* it is not always needed, but we aim to smaller code */
4128 int squirrel[] = { -1, -1, -1 };
4131 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4134 IF_HUSH_JOB(pi->pgrp = -1;)
4135 pi->stopped_cmds = 0;
4136 command = &(pi->cmds[0]);
4137 argv_expanded = NULL;
4139 if (pi->num_cmds != 1
4140 || pi->followup == PIPE_BG
4141 || command->cmd_type == CMD_SUBSHELL
4148 debug_printf_exec(": group:%p argv:'%s'\n",
4149 command->group, command->argv ? command->argv[0] : "NONE");
4151 if (command->group) {
4152 #if ENABLE_HUSH_FUNCTIONS
4153 if (command->cmd_type == CMD_FUNCDEF) {
4154 /* "executing" func () { list } */
4155 struct function *funcp;
4157 funcp = new_function(command->argv[0]);
4158 /* funcp->name is already set to argv[0] */
4159 funcp->body = command->group;
4161 funcp->body_as_string = command->group_as_string;
4162 command->group_as_string = NULL;
4164 command->group = NULL;
4165 command->argv[0] = NULL;
4166 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4167 funcp->parent_cmd = command;
4168 command->child_func = funcp;
4170 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4172 return EXIT_SUCCESS;
4176 debug_printf("non-subshell group\n");
4177 rcode = 1; /* exitcode if redir failed */
4178 if (setup_redirects(command, squirrel) == 0) {
4179 debug_printf_exec(": run_list\n");
4180 rcode = run_list(command->group) & 0xff;
4182 restore_redirects(squirrel);
4183 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4185 debug_printf_exec("run_pipe: return %d\n", rcode);
4189 argv = command->argv ? command->argv : (char **) &null_ptr;
4191 const struct built_in_command *x;
4192 #if ENABLE_HUSH_FUNCTIONS
4193 const struct function *funcp;
4197 char **new_env = NULL;
4198 struct variable *old_vars = NULL;
4200 if (argv[command->assignment_cnt] == NULL) {
4201 /* Assignments, but no command */
4202 /* Ensure redirects take effect (that is, create files).
4203 * Try "a=t >file": */
4204 rcode = setup_redirects(command, squirrel);
4205 restore_redirects(squirrel);
4206 /* Set shell variables */
4208 p = expand_string_to_string(*argv);
4209 debug_printf_exec("set shell var:'%s'->'%s'\n",
4211 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4214 /* Redirect error sets $? to 1. Othervise,
4215 * if evaluating assignment value set $?, retain it.
4216 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4218 rcode = G.last_exitcode;
4219 /* Do we need to flag set_local_var() errors?
4220 * "assignment to readonly var" and "putenv error"
4222 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4224 debug_printf_exec("run_pipe: return %d\n", rcode);
4228 /* Expand the rest into (possibly) many strings each */
4230 #if ENABLE_HUSH_BASH_COMPAT
4231 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4232 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4235 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4236 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4237 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4242 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4245 /* if someone gives us an empty string: `cmd with empty output` */
4246 if (!argv_expanded[0]) {
4247 free(argv_expanded);
4249 return G.last_exitcode;
4252 x = find_builtin(argv_expanded[0]);
4253 #if ENABLE_HUSH_FUNCTIONS
4256 funcp = find_function(argv_expanded[0]);
4260 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4261 debug_printf("exec with redirects only\n");
4262 rcode = setup_redirects(command, NULL);
4263 goto clean_up_and_ret1;
4266 /* setup_redirects acts on file descriptors, not FILEs.
4267 * This is perfect for work that comes after exec().
4268 * Is it really safe for inline use? Experimentally,
4269 * things seem to work. */
4270 rcode = setup_redirects(command, squirrel);
4272 new_env = expand_assignments(argv, command->assignment_cnt);
4273 old_vars = set_vars_and_save_old(new_env);
4275 debug_printf_exec(": builtin '%s' '%s'...\n",
4276 x->b_cmd, argv_expanded[1]);
4277 rcode = x->b_function(argv_expanded) & 0xff;
4280 #if ENABLE_HUSH_FUNCTIONS
4282 # if ENABLE_HUSH_LOCAL
4283 struct variable **sv;
4284 sv = G.shadowed_vars_pp;
4285 G.shadowed_vars_pp = &old_vars;
4287 debug_printf_exec(": function '%s' '%s'...\n",
4288 funcp->name, argv_expanded[1]);
4289 rcode = run_function(funcp, argv_expanded) & 0xff;
4290 # if ENABLE_HUSH_LOCAL
4291 G.shadowed_vars_pp = sv;
4296 #if ENABLE_FEATURE_SH_STANDALONE
4299 restore_redirects(squirrel);
4300 unset_vars(new_env);
4303 free(argv_expanded);
4304 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4306 debug_printf_exec("run_pipe return %d\n", rcode);
4310 #if ENABLE_FEATURE_SH_STANDALONE
4311 i = find_applet_by_name(argv_expanded[0]);
4312 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4313 rcode = setup_redirects(command, squirrel);
4315 new_env = expand_assignments(argv, command->assignment_cnt);
4316 old_vars = set_vars_and_save_old(new_env);
4317 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4318 argv_expanded[0], argv_expanded[1]);
4319 rcode = run_nofork_applet(i, argv_expanded);
4321 goto clean_up_and_ret;
4324 /* It is neither builtin nor applet. We must fork. */
4328 /* NB: argv_expanded may already be created, and that
4329 * might include `cmd` runs! Do not rerun it! We *must*
4330 * use argv_expanded if it's non-NULL */
4332 /* Going to fork a child per each pipe member */
4336 for (i = 0; i < pi->num_cmds; i++) {
4337 struct fd_pair pipefds;
4339 volatile nommu_save_t nommu_save;
4340 nommu_save.new_env = NULL;
4341 nommu_save.old_vars = NULL;
4342 nommu_save.argv = NULL;
4343 nommu_save.argv_from_re_execing = NULL;
4345 command = &(pi->cmds[i]);
4346 if (command->argv) {
4347 debug_printf_exec(": pipe member '%s' '%s'...\n",
4348 command->argv[0], command->argv[1]);
4350 debug_printf_exec(": pipe member with no argv\n");
4353 /* pipes are inserted between pairs of commands */
4356 if ((i + 1) < pi->num_cmds)
4357 xpiped_pair(pipefds);
4359 command->pid = BB_MMU ? fork() : vfork();
4360 if (!command->pid) { /* child */
4362 disable_restore_tty_pgrp_on_exit();
4363 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4365 /* Every child adds itself to new process group
4366 * with pgid == pid_of_first_child_in_pipe */
4367 if (G.run_list_level == 1 && G_interactive_fd) {
4370 if (pgrp < 0) /* true for 1st process only */
4372 if (setpgid(0, pgrp) == 0
4373 && pi->followup != PIPE_BG
4374 && G_saved_tty_pgrp /* we have ctty */
4376 /* We do it in *every* child, not just first,
4378 tcsetpgrp(G_interactive_fd, pgrp);
4382 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4383 /* 1st cmd in backgrounded pipe
4384 * should have its stdin /dev/null'ed */
4386 if (open(bb_dev_null, O_RDONLY))
4387 xopen("/", O_RDONLY);
4389 xmove_fd(nextin, 0);
4391 xmove_fd(pipefds.wr, 1);
4394 /* Like bash, explicit redirects override pipes,
4395 * and the pipe fd is available for dup'ing. */
4396 if (setup_redirects(command, NULL))
4399 /* Restore default handlers just prior to exec */
4400 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4402 /* Stores to nommu_save list of env vars putenv'ed
4403 * (NOMMU, on MMU we don't need that) */
4404 /* cast away volatility... */
4405 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4406 /* pseudo_exec() does not return */
4409 /* parent or error */
4410 #if ENABLE_HUSH_FAST
4412 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4414 enable_restore_tty_pgrp_on_exit();
4416 /* Clean up after vforked child */
4417 free(nommu_save.argv);
4418 free(nommu_save.argv_from_re_execing);
4419 unset_vars(nommu_save.new_env);
4420 add_vars(nommu_save.old_vars);
4422 free(argv_expanded);
4423 argv_expanded = NULL;
4424 if (command->pid < 0) { /* [v]fork failed */
4425 /* Clearly indicate, was it fork or vfork */
4426 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4430 /* Second and next children need to know pid of first one */
4432 pi->pgrp = command->pid;
4438 if ((i + 1) < pi->num_cmds)
4440 /* Pass read (output) pipe end to next iteration */
4441 nextin = pipefds.rd;
4444 if (!pi->alive_cmds) {
4446 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4451 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4455 #ifndef debug_print_tree
4456 static void debug_print_tree(struct pipe *pi, int lvl)
4458 static const char *const PIPE[] = {
4464 static const char *RES[] = {
4465 [RES_NONE ] = "NONE" ,
4468 [RES_THEN ] = "THEN" ,
4469 [RES_ELIF ] = "ELIF" ,
4470 [RES_ELSE ] = "ELSE" ,
4473 # if ENABLE_HUSH_LOOPS
4474 [RES_FOR ] = "FOR" ,
4475 [RES_WHILE] = "WHILE",
4476 [RES_UNTIL] = "UNTIL",
4478 [RES_DONE ] = "DONE" ,
4480 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4483 # if ENABLE_HUSH_CASE
4484 [RES_CASE ] = "CASE" ,
4485 [RES_CASE_IN ] = "CASE_IN" ,
4486 [RES_MATCH] = "MATCH",
4487 [RES_CASE_BODY] = "CASE_BODY",
4488 [RES_ESAC ] = "ESAC" ,
4490 [RES_XXXX ] = "XXXX" ,
4491 [RES_SNTX ] = "SNTX" ,
4493 static const char *const CMDTYPE[] = {
4497 # if ENABLE_HUSH_FUNCTIONS
4506 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4507 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4509 while (prn < pi->num_cmds) {
4510 struct command *command = &pi->cmds[prn];
4511 char **argv = command->argv;
4513 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4515 command->assignment_cnt);
4516 if (command->group) {
4517 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4518 CMDTYPE[command->cmd_type],
4521 , " group_as_string:", command->group_as_string
4526 debug_print_tree(command->group, lvl+1);
4530 if (argv) while (*argv) {
4531 fprintf(stderr, " '%s'", *argv);
4534 fprintf(stderr, "\n");
4541 #endif /* debug_print_tree */
4543 /* NB: called by pseudo_exec, and therefore must not modify any
4544 * global data until exec/_exit (we can be a child after vfork!) */
4545 static int run_list(struct pipe *pi)
4547 #if ENABLE_HUSH_CASE
4548 char *case_word = NULL;
4550 #if ENABLE_HUSH_LOOPS
4551 struct pipe *loop_top = NULL;
4552 char **for_lcur = NULL;
4553 char **for_list = NULL;
4555 smallint last_followup;
4557 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4558 smalluint cond_code = 0;
4560 enum { cond_code = 0 };
4563 smallint rword; /* enum reserved_style */
4564 smallint last_rword; /* ditto */
4567 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4570 #if ENABLE_HUSH_LOOPS
4571 /* Check syntax for "for" */
4572 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4573 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4575 /* current word is FOR or IN (BOLD in comments below) */
4576 if (cpipe->next == NULL) {
4577 syntax_error("malformed for");
4579 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4582 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4583 if (cpipe->next->res_word == RES_DO)
4585 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4586 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4587 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4589 syntax_error("malformed for");
4591 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4597 /* Past this point, all code paths should jump to ret: label
4598 * in order to return, no direct "return" statements please.
4599 * This helps to ensure that no memory is leaked. */
4607 last_rword = RES_XXXX;
4609 last_followup = PIPE_SEQ;
4610 rcode = G.last_exitcode;
4612 /* Go through list of pipes, (maybe) executing them. */
4613 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4617 IF_HAS_KEYWORDS(rword = pi->res_word;)
4618 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4619 rword, cond_code, last_rword);
4620 #if ENABLE_HUSH_LOOPS
4621 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4622 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4624 /* start of a loop: remember where loop starts */
4629 /* Still in the same "if...", "then..." or "do..." branch? */
4630 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4631 if ((rcode == 0 && last_followup == PIPE_OR)
4632 || (rcode != 0 && last_followup == PIPE_AND)
4634 /* It is "<true> || CMD" or "<false> && CMD"
4635 * and we should not execute CMD */
4636 debug_printf_exec("skipped cmd because of || or &&\n");
4637 last_followup = pi->followup;
4641 last_followup = pi->followup;
4642 IF_HAS_KEYWORDS(last_rword = rword;)
4645 if (rword == RES_THEN) {
4646 /* if false; then ... fi has exitcode 0! */
4647 G.last_exitcode = rcode = EXIT_SUCCESS;
4648 /* "if <false> THEN cmd": skip cmd */
4652 if (rword == RES_ELSE || rword == RES_ELIF) {
4653 /* "if <true> then ... ELSE/ELIF cmd":
4654 * skip cmd and all following ones */
4659 #if ENABLE_HUSH_LOOPS
4660 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4662 /* first loop through for */
4664 static const char encoded_dollar_at[] ALIGN1 = {
4665 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4666 }; /* encoded representation of "$@" */
4667 static const char *const encoded_dollar_at_argv[] = {
4668 encoded_dollar_at, NULL
4669 }; /* argv list with one element: "$@" */
4672 vals = (char**)encoded_dollar_at_argv;
4673 if (pi->next->res_word == RES_IN) {
4674 /* if no variable values after "in" we skip "for" */
4675 if (!pi->next->cmds[0].argv) {
4676 G.last_exitcode = rcode = EXIT_SUCCESS;
4677 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4680 vals = pi->next->cmds[0].argv;
4681 } /* else: "for var; do..." -> assume "$@" list */
4682 /* create list of variable values */
4683 debug_print_strings("for_list made from", vals);
4684 for_list = expand_strvec_to_strvec(vals);
4685 for_lcur = for_list;
4686 debug_print_strings("for_list", for_list);
4689 /* "for" loop is over, clean up */
4695 /* Insert next value from for_lcur */
4696 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4697 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4700 if (rword == RES_IN) {
4701 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4703 if (rword == RES_DONE) {
4704 continue; /* "done" has no cmds too */
4707 #if ENABLE_HUSH_CASE
4708 if (rword == RES_CASE) {
4709 case_word = expand_strvec_to_string(pi->cmds->argv);
4712 if (rword == RES_MATCH) {
4715 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4717 /* all prev words didn't match, does this one match? */
4718 argv = pi->cmds->argv;
4720 char *pattern = expand_string_to_string(*argv);
4721 /* TODO: which FNM_xxx flags to use? */
4722 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4724 if (cond_code == 0) { /* match! we will execute this branch */
4725 free(case_word); /* make future "word)" stop */
4733 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4735 continue; /* not matched yet, skip this pipe */
4738 /* Just pressing <enter> in shell should check for jobs.
4739 * OTOH, in non-interactive shell this is useless
4740 * and only leads to extra job checks */
4741 if (pi->num_cmds == 0) {
4742 if (G_interactive_fd)
4743 goto check_jobs_and_continue;
4747 /* After analyzing all keywords and conditions, we decided
4748 * to execute this pipe. NB: have to do checkjobs(NULL)
4749 * after run_pipe to collect any background children,
4750 * even if list execution is to be stopped. */
4751 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4754 #if ENABLE_HUSH_LOOPS
4755 G.flag_break_continue = 0;
4757 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4759 /* We ran a builtin, function, or group.
4760 * rcode is already known
4761 * and we don't need to wait for anything. */
4762 G.last_exitcode = rcode;
4763 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4764 check_and_run_traps(0);
4765 #if ENABLE_HUSH_LOOPS
4766 /* Was it "break" or "continue"? */
4767 if (G.flag_break_continue) {
4768 smallint fbc = G.flag_break_continue;
4769 /* We might fall into outer *loop*,
4770 * don't want to break it too */
4772 G.depth_break_continue--;
4773 if (G.depth_break_continue == 0)
4774 G.flag_break_continue = 0;
4775 /* else: e.g. "continue 2" should *break* once, *then* continue */
4776 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4777 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4778 goto check_jobs_and_break;
4779 /* "continue": simulate end of loop */
4784 #if ENABLE_HUSH_FUNCTIONS
4785 if (G.flag_return_in_progress == 1) {
4786 /* same as "goto check_jobs_and_break" */
4791 } else if (pi->followup == PIPE_BG) {
4792 /* What does bash do with attempts to background builtins? */
4793 /* even bash 3.2 doesn't do that well with nested bg:
4794 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4795 * I'm NOT treating inner &'s as jobs */
4796 check_and_run_traps(0);
4798 if (G.run_list_level == 1)
4801 G.last_exitcode = rcode = EXIT_SUCCESS;
4802 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4805 if (G.run_list_level == 1 && G_interactive_fd) {
4806 /* Waits for completion, then fg's main shell */
4807 rcode = checkjobs_and_fg_shell(pi);
4808 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4809 check_and_run_traps(0);
4812 { /* This one just waits for completion */
4813 rcode = checkjobs(pi);
4814 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4815 check_and_run_traps(0);
4817 G.last_exitcode = rcode;
4821 /* Analyze how result affects subsequent commands */
4823 if (rword == RES_IF || rword == RES_ELIF)
4826 #if ENABLE_HUSH_LOOPS
4827 /* Beware of "while false; true; do ..."! */
4828 if (pi->next && pi->next->res_word == RES_DO) {
4829 if (rword == RES_WHILE) {
4831 /* "while false; do...done" - exitcode 0 */
4832 G.last_exitcode = rcode = EXIT_SUCCESS;
4833 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4834 goto check_jobs_and_break;
4837 if (rword == RES_UNTIL) {
4839 debug_printf_exec(": until expr is true: breaking\n");
4840 check_jobs_and_break:
4848 check_jobs_and_continue:
4855 #if ENABLE_HUSH_LOOPS
4860 #if ENABLE_HUSH_CASE
4864 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4868 /* Select which version we will use */
4869 static int run_and_free_list(struct pipe *pi)
4872 debug_printf_exec("run_and_free_list entered\n");
4874 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4875 rcode = run_list(pi);
4877 /* free_pipe_list has the side effect of clearing memory.
4878 * In the long run that function can be merged with run_list,
4879 * but doing that now would hobble the debugging effort. */
4881 debug_printf_exec("run_and_free_list return %d\n", rcode);
4886 static struct pipe *new_pipe(void)
4889 pi = xzalloc(sizeof(struct pipe));
4890 /*pi->followup = 0; - deliberately invalid value */
4891 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4895 /* Command (member of a pipe) is complete, or we start a new pipe
4896 * if ctx->command is NULL.
4897 * No errors possible here.
4899 static int done_command(struct parse_context *ctx)
4901 /* The command is really already in the pipe structure, so
4902 * advance the pipe counter and make a new, null command. */
4903 struct pipe *pi = ctx->pipe;
4904 struct command *command = ctx->command;
4907 if (IS_NULL_CMD(command)) {
4908 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4912 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4913 //debug_print_tree(ctx->list_head, 20);
4915 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4918 /* Only real trickiness here is that the uncommitted
4919 * command structure is not counted in pi->num_cmds. */
4920 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4921 ctx->command = command = &pi->cmds[pi->num_cmds];
4923 memset(command, 0, sizeof(*command));
4924 return pi->num_cmds; /* used only for 0/nonzero check */
4927 static void done_pipe(struct parse_context *ctx, pipe_style type)
4931 debug_printf_parse("done_pipe entered, followup %d\n", type);
4932 /* Close previous command */
4933 not_null = done_command(ctx);
4934 ctx->pipe->followup = type;
4936 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4937 ctx->ctx_inverted = 0;
4938 ctx->pipe->res_word = ctx->ctx_res_w;
4941 /* Without this check, even just <enter> on command line generates
4942 * tree of three NOPs (!). Which is harmless but annoying.
4943 * IOW: it is safe to do it unconditionally. */
4946 || ctx->ctx_res_w == RES_FI
4948 #if ENABLE_HUSH_LOOPS
4949 || ctx->ctx_res_w == RES_DONE
4950 || ctx->ctx_res_w == RES_FOR
4951 || ctx->ctx_res_w == RES_IN
4953 #if ENABLE_HUSH_CASE
4954 || ctx->ctx_res_w == RES_ESAC
4958 debug_printf_parse("done_pipe: adding new pipe: "
4959 "not_null:%d ctx->ctx_res_w:%d\n",
4960 not_null, ctx->ctx_res_w);
4962 ctx->pipe->next = new_p;
4964 /* RES_THEN, RES_DO etc are "sticky" -
4965 * they remain set for pipes inside if/while.
4966 * This is used to control execution.
4967 * RES_FOR and RES_IN are NOT sticky (needed to support
4968 * cases where variable or value happens to match a keyword):
4970 #if ENABLE_HUSH_LOOPS
4971 if (ctx->ctx_res_w == RES_FOR
4972 || ctx->ctx_res_w == RES_IN)
4973 ctx->ctx_res_w = RES_NONE;
4975 #if ENABLE_HUSH_CASE
4976 if (ctx->ctx_res_w == RES_MATCH)
4977 ctx->ctx_res_w = RES_CASE_BODY;
4978 if (ctx->ctx_res_w == RES_CASE)
4979 ctx->ctx_res_w = RES_CASE_IN;
4981 ctx->command = NULL; /* trick done_command below */
4982 /* Create the memory for command, roughly:
4983 * ctx->pipe->cmds = new struct command;
4984 * ctx->command = &ctx->pipe->cmds[0];
4987 //debug_print_tree(ctx->list_head, 10);
4989 debug_printf_parse("done_pipe return\n");
4992 static void initialize_context(struct parse_context *ctx)
4994 memset(ctx, 0, sizeof(*ctx));
4995 ctx->pipe = ctx->list_head = new_pipe();
4996 /* Create the memory for command, roughly:
4997 * ctx->pipe->cmds = new struct command;
4998 * ctx->command = &ctx->pipe->cmds[0];
5003 /* If a reserved word is found and processed, parse context is modified
5004 * and 1 is returned.
5007 struct reserved_combo {
5010 unsigned char assignment_flag;
5014 FLAG_END = (1 << RES_NONE ),
5016 FLAG_IF = (1 << RES_IF ),
5017 FLAG_THEN = (1 << RES_THEN ),
5018 FLAG_ELIF = (1 << RES_ELIF ),
5019 FLAG_ELSE = (1 << RES_ELSE ),
5020 FLAG_FI = (1 << RES_FI ),
5022 # if ENABLE_HUSH_LOOPS
5023 FLAG_FOR = (1 << RES_FOR ),
5024 FLAG_WHILE = (1 << RES_WHILE),
5025 FLAG_UNTIL = (1 << RES_UNTIL),
5026 FLAG_DO = (1 << RES_DO ),
5027 FLAG_DONE = (1 << RES_DONE ),
5028 FLAG_IN = (1 << RES_IN ),
5030 # if ENABLE_HUSH_CASE
5031 FLAG_MATCH = (1 << RES_MATCH),
5032 FLAG_ESAC = (1 << RES_ESAC ),
5034 FLAG_START = (1 << RES_XXXX ),
5037 static const struct reserved_combo* match_reserved_word(o_string *word)
5039 /* Mostly a list of accepted follow-up reserved words.
5040 * FLAG_END means we are done with the sequence, and are ready
5041 * to turn the compound list into a command.
5042 * FLAG_START means the word must start a new compound list.
5044 static const struct reserved_combo reserved_list[] = {
5046 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5047 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5048 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5049 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5050 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5051 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5053 # if ENABLE_HUSH_LOOPS
5054 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5055 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5056 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5057 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5058 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5059 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5061 # if ENABLE_HUSH_CASE
5062 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5063 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5066 const struct reserved_combo *r;
5068 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5069 if (strcmp(word->data, r->literal) == 0)
5074 /* Return 0: not a keyword, 1: keyword
5076 static int reserved_word(o_string *word, struct parse_context *ctx)
5078 # if ENABLE_HUSH_CASE
5079 static const struct reserved_combo reserved_match = {
5080 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5083 const struct reserved_combo *r;
5087 r = match_reserved_word(word);
5091 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5092 # if ENABLE_HUSH_CASE
5093 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5094 /* "case word IN ..." - IN part starts first MATCH part */
5095 r = &reserved_match;
5098 if (r->flag == 0) { /* '!' */
5099 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5100 syntax_error("! ! command");
5101 ctx->ctx_res_w = RES_SNTX;
5103 ctx->ctx_inverted = 1;
5106 if (r->flag & FLAG_START) {
5107 struct parse_context *old;
5109 old = xmalloc(sizeof(*old));
5110 debug_printf_parse("push stack %p\n", old);
5111 *old = *ctx; /* physical copy */
5112 initialize_context(ctx);
5114 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5115 syntax_error_at(word->data);
5116 ctx->ctx_res_w = RES_SNTX;
5119 /* "{...} fi" is ok. "{...} if" is not
5121 * if { echo foo; } then { echo bar; } fi */
5122 if (ctx->command->group)
5123 done_pipe(ctx, PIPE_SEQ);
5126 ctx->ctx_res_w = r->res;
5127 ctx->old_flag = r->flag;
5128 word->o_assignment = r->assignment_flag;
5130 if (ctx->old_flag & FLAG_END) {
5131 struct parse_context *old;
5133 done_pipe(ctx, PIPE_SEQ);
5134 debug_printf_parse("pop stack %p\n", ctx->stack);
5136 old->command->group = ctx->list_head;
5137 old->command->cmd_type = CMD_NORMAL;
5139 o_addstr(&old->as_string, ctx->as_string.data);
5140 o_free_unsafe(&ctx->as_string);
5141 old->command->group_as_string = xstrdup(old->as_string.data);
5142 debug_printf_parse("pop, remembering as:'%s'\n",
5143 old->command->group_as_string);
5145 *ctx = *old; /* physical copy */
5150 #endif /* HAS_KEYWORDS */
5152 /* Word is complete, look at it and update parsing context.
5153 * Normal return is 0. Syntax errors return 1.
5154 * Note: on return, word is reset, but not o_free'd!
5156 static int done_word(o_string *word, struct parse_context *ctx)
5158 struct command *command = ctx->command;
5160 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5161 if (word->length == 0 && word->o_quoted == 0) {
5162 debug_printf_parse("done_word return 0: true null, ignored\n");
5166 if (ctx->pending_redirect) {
5167 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5168 * only if run as "bash", not "sh" */
5169 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5171 * ...the word that follows the redirection operator
5172 * shall be subjected to tilde expansion, parameter expansion,
5173 * command substitution, arithmetic expansion, and quote
5174 * removal. Pathname expansion shall not be performed
5175 * on the word by a non-interactive shell; an interactive
5176 * shell may perform it, but shall do so only when
5177 * the expansion would result in one word."
5179 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5180 /* Cater for >\file case:
5181 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5182 * Same with heredocs:
5183 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5185 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5186 unbackslash(ctx->pending_redirect->rd_filename);
5187 /* Is it <<"HEREDOC"? */
5188 if (word->o_quoted) {
5189 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5192 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5193 ctx->pending_redirect = NULL;
5195 /* If this word wasn't an assignment, next ones definitely
5196 * can't be assignments. Even if they look like ones. */
5197 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5198 && word->o_assignment != WORD_IS_KEYWORD
5200 word->o_assignment = NOT_ASSIGNMENT;
5202 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5203 command->assignment_cnt++;
5204 word->o_assignment = MAYBE_ASSIGNMENT;
5208 # if ENABLE_HUSH_CASE
5209 if (ctx->ctx_dsemicolon
5210 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5212 /* already done when ctx_dsemicolon was set to 1: */
5213 /* ctx->ctx_res_w = RES_MATCH; */
5214 ctx->ctx_dsemicolon = 0;
5217 if (!command->argv /* if it's the first word... */
5218 # if ENABLE_HUSH_LOOPS
5219 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5220 && ctx->ctx_res_w != RES_IN
5222 # if ENABLE_HUSH_CASE
5223 && ctx->ctx_res_w != RES_CASE
5226 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5227 if (reserved_word(word, ctx)) {
5228 o_reset_to_empty_unquoted(word);
5229 debug_printf_parse("done_word return %d\n",
5230 (ctx->ctx_res_w == RES_SNTX));
5231 return (ctx->ctx_res_w == RES_SNTX);
5233 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5234 if (strcmp(word->data, "export") == 0
5235 # if ENABLE_HUSH_LOCAL
5236 || strcmp(word->data, "local") == 0
5239 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5242 # if ENABLE_HUSH_BASH_COMPAT
5243 if (strcmp(word->data, "[[") == 0) {
5244 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5250 if (command->group) {
5251 /* "{ echo foo; } echo bar" - bad */
5252 syntax_error_at(word->data);
5253 debug_printf_parse("done_word return 1: syntax error, "
5254 "groups and arglists don't mix\n");
5257 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5258 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5259 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5260 /* (otherwise it's known to be not empty and is already safe) */
5262 /* exclude "$@" - it can expand to no word despite "" */
5263 char *p = word->data;
5264 while (p[0] == SPECIAL_VAR_SYMBOL
5265 && (p[1] & 0x7f) == '@'
5266 && p[2] == SPECIAL_VAR_SYMBOL
5270 if (p == word->data || p[0] != '\0') {
5271 /* saw no "$@", or not only "$@" but some
5272 * real text is there too */
5273 /* insert "empty variable" reference, this makes
5274 * e.g. "", $empty"" etc to not disappear */
5275 o_addchr(word, SPECIAL_VAR_SYMBOL);
5276 o_addchr(word, SPECIAL_VAR_SYMBOL);
5279 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5280 debug_print_strings("word appended to argv", command->argv);
5283 #if ENABLE_HUSH_LOOPS
5284 if (ctx->ctx_res_w == RES_FOR) {
5286 || !is_well_formed_var_name(command->argv[0], '\0')
5288 /* bash says just "not a valid identifier" */
5289 syntax_error("not a valid identifier in for");
5292 /* Force FOR to have just one word (variable name) */
5293 /* NB: basically, this makes hush see "for v in ..."
5294 * syntax as if it is "for v; in ...". FOR and IN become
5295 * two pipe structs in parse tree. */
5296 done_pipe(ctx, PIPE_SEQ);
5299 #if ENABLE_HUSH_CASE
5300 /* Force CASE to have just one word */
5301 if (ctx->ctx_res_w == RES_CASE) {
5302 done_pipe(ctx, PIPE_SEQ);
5306 o_reset_to_empty_unquoted(word);
5308 debug_printf_parse("done_word return 0\n");
5313 /* Peek ahead in the input to find out if we have a "&n" construct,
5314 * as in "2>&1", that represents duplicating a file descriptor.
5316 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5317 * REDIRFD_SYNTAX_ERR if syntax error,
5318 * REDIRFD_TO_FILE if no & was seen,
5319 * or the number found.
5322 #define parse_redir_right_fd(as_string, input) \
5323 parse_redir_right_fd(input)
5325 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5331 return REDIRFD_TO_FILE;
5333 ch = i_getch(input); /* get the & */
5334 nommu_addchr(as_string, ch);
5337 ch = i_getch(input);
5338 nommu_addchr(as_string, ch);
5339 return REDIRFD_CLOSE;
5343 while (ch != EOF && isdigit(ch)) {
5344 d = d*10 + (ch-'0');
5346 ch = i_getch(input);
5347 nommu_addchr(as_string, ch);
5352 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5354 bb_error_msg("ambiguous redirect");
5355 return REDIRFD_SYNTAX_ERR;
5358 /* Return code is 0 normal, 1 if a syntax error is detected
5360 static int parse_redirect(struct parse_context *ctx,
5363 struct in_str *input)
5365 struct command *command = ctx->command;
5366 struct redir_struct *redir;
5367 struct redir_struct **redirp;
5370 dup_num = REDIRFD_TO_FILE;
5371 if (style != REDIRECT_HEREDOC) {
5372 /* Check for a '>&1' type redirect */
5373 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5374 if (dup_num == REDIRFD_SYNTAX_ERR)
5377 int ch = i_peek(input);
5378 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5379 if (dup_num) { /* <<-... */
5380 ch = i_getch(input);
5381 nommu_addchr(&ctx->as_string, ch);
5386 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5387 int ch = i_peek(input);
5389 /* >|FILE redirect ("clobbering" >).
5390 * Since we do not support "set -o noclobber" yet,
5391 * >| and > are the same for now. Just eat |.
5393 ch = i_getch(input);
5394 nommu_addchr(&ctx->as_string, ch);
5398 /* Create a new redir_struct and append it to the linked list */
5399 redirp = &command->redirects;
5400 while ((redir = *redirp) != NULL) {
5401 redirp = &(redir->next);
5403 *redirp = redir = xzalloc(sizeof(*redir));
5404 /* redir->next = NULL; */
5405 /* redir->rd_filename = NULL; */
5406 redir->rd_type = style;
5407 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5409 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5410 redir_table[style].descrip);
5412 redir->rd_dup = dup_num;
5413 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5414 /* Erik had a check here that the file descriptor in question
5415 * is legit; I postpone that to "run time"
5416 * A "-" representation of "close me" shows up as a -3 here */
5417 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5418 redir->rd_fd, redir->rd_dup);
5420 /* Set ctx->pending_redirect, so we know what to do at the
5421 * end of the next parsed word. */
5422 ctx->pending_redirect = redir;
5427 /* If a redirect is immediately preceded by a number, that number is
5428 * supposed to tell which file descriptor to redirect. This routine
5429 * looks for such preceding numbers. In an ideal world this routine
5430 * needs to handle all the following classes of redirects...
5431 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5432 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5433 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5434 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5436 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5438 * ... If n is quoted, the number shall not be recognized as part of
5439 * the redirection expression. For example:
5441 * writes the character 2 into file a"
5442 * We are getting it right by setting ->o_quoted on any \<char>
5444 * A -1 return means no valid number was found,
5445 * the caller should use the appropriate default for this redirection.
5447 static int redirect_opt_num(o_string *o)
5451 if (o->data == NULL)
5453 num = bb_strtou(o->data, NULL, 10);
5454 if (errno || num < 0)
5456 o_reset_to_empty_unquoted(o);
5461 #define fetch_till_str(as_string, input, word, skip_tabs) \
5462 fetch_till_str(input, word, skip_tabs)
5464 static char *fetch_till_str(o_string *as_string,
5465 struct in_str *input,
5469 o_string heredoc = NULL_O_STRING;
5475 ch = i_getch(input);
5476 nommu_addchr(as_string, ch);
5478 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5479 heredoc.data[past_EOL] = '\0';
5480 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5481 return heredoc.data;
5484 o_addchr(&heredoc, ch);
5485 past_EOL = heredoc.length;
5488 ch = i_getch(input);
5489 nommu_addchr(as_string, ch);
5490 } while (skip_tabs && ch == '\t');
5491 } while (ch == '\n');
5494 o_free_unsafe(&heredoc);
5497 o_addchr(&heredoc, ch);
5498 nommu_addchr(as_string, ch);
5502 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5503 * and load them all. There should be exactly heredoc_cnt of them.
5505 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5507 struct pipe *pi = ctx->list_head;
5509 while (pi && heredoc_cnt) {
5511 struct command *cmd = pi->cmds;
5513 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5515 cmd->argv ? cmd->argv[0] : "NONE");
5516 for (i = 0; i < pi->num_cmds; i++) {
5517 struct redir_struct *redir = cmd->redirects;
5519 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5520 i, cmd->argv ? cmd->argv[0] : "NONE");
5522 if (redir->rd_type == REDIRECT_HEREDOC) {
5525 redir->rd_type = REDIRECT_HEREDOC2;
5526 /* redir->rd_dup is (ab)used to indicate <<- */
5527 p = fetch_till_str(&ctx->as_string, input,
5528 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5530 syntax_error("unexpected EOF in here document");
5533 free(redir->rd_filename);
5534 redir->rd_filename = p;
5537 redir = redir->next;
5544 /* Should be 0. If it isn't, it's a parse error */
5546 bb_error_msg_and_die("heredoc BUG 2");
5552 #if ENABLE_HUSH_TICK
5553 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5558 char **to_free = NULL;
5562 pid = BB_MMU ? fork() : vfork();
5564 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5566 if (pid == 0) { /* child */
5567 disable_restore_tty_pgrp_on_exit();
5568 /* Process substitution is not considered to be usual
5569 * 'command execution'.
5570 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5577 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5578 close(channel[0]); /* NB: close _first_, then move fd! */
5579 xmove_fd(channel[1], 1);
5580 /* Prevent it from trying to handle ctrl-z etc */
5581 IF_HUSH_JOB(G.run_list_level = 1;)
5582 /* Awful hack for `trap` or $(trap).
5584 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5585 * contains an example where "trap" is executed in a subshell:
5587 * save_traps=$(trap)
5589 * eval "$save_traps"
5591 * Standard does not say that "trap" in subshell shall print
5592 * parent shell's traps. It only says that its output
5593 * must have suitable form, but then, in the above example
5594 * (which is not supposed to be normative), it implies that.
5596 * bash (and probably other shell) does implement it
5597 * (traps are reset to defaults, but "trap" still shows them),
5598 * but as a result, "trap" logic is hopelessly messed up:
5601 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5602 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5603 * # true | trap <--- trap is in subshell - no output (ditto)
5604 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5605 * trap -- 'echo Ho' SIGWINCH
5606 * # echo `(trap)` <--- in subshell in subshell - output
5607 * trap -- 'echo Ho' SIGWINCH
5608 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5609 * trap -- 'echo Ho' SIGWINCH
5611 * The rules when to forget and when to not forget traps
5612 * get really complex and nonsensical.
5614 * Our solution: ONLY bare $(trap) or `trap` is special.
5616 s = skip_whitespace(s);
5617 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5619 static const char *const argv[] = { NULL, NULL };
5620 builtin_trap((char**)argv);
5621 exit(0); /* not _exit() - we need to fflush */
5624 reset_traps_to_defaults();
5625 parse_and_run_string(s);
5626 _exit(G.last_exitcode);
5628 /* We re-execute after vfork on NOMMU. This makes this script safe:
5629 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5630 * huge=`cat BIG` # was blocking here forever
5633 re_execute_shell(&to_free,
5643 # if ENABLE_HUSH_FAST
5645 //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);
5647 enable_restore_tty_pgrp_on_exit();
5652 close_on_exec_on(channel[0]);
5653 return xfdopen_for_read(channel[0]);
5656 /* Return code is exit status of the process that is run. */
5657 static int process_command_subs(o_string *dest, const char *s)
5660 struct in_str pipe_str;
5662 int status, ch, eol_cnt;
5664 fp = generate_stream_from_string(s, &pid);
5666 /* Now send results of command back into original context */
5667 setup_file_in_str(&pipe_str, fp);
5669 while ((ch = i_getch(&pipe_str)) != EOF) {
5675 o_addchr(dest, '\n');
5678 o_addQchr(dest, ch);
5681 debug_printf("done reading from `cmd` pipe, closing it\n");
5683 /* We need to extract exitcode. Test case
5684 * "true; echo `sleep 1; false` $?"
5686 safe_waitpid(pid, &status, 0);
5687 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5688 return WEXITSTATUS(status);
5690 #endif /* ENABLE_HUSH_TICK */
5692 #if !ENABLE_HUSH_FUNCTIONS
5693 #define parse_group(dest, ctx, input, ch) \
5694 parse_group(ctx, input, ch)
5696 static int parse_group(o_string *dest, struct parse_context *ctx,
5697 struct in_str *input, int ch)
5699 /* dest contains characters seen prior to ( or {.
5700 * Typically it's empty, but for function defs,
5701 * it contains function name (without '()'). */
5702 struct pipe *pipe_list;
5704 struct command *command = ctx->command;
5706 debug_printf_parse("parse_group entered\n");
5707 #if ENABLE_HUSH_FUNCTIONS
5708 if (ch == '(' && !dest->o_quoted) {
5710 if (done_word(dest, ctx))
5713 goto skip; /* (... */
5714 if (command->argv[1]) { /* word word ... (... */
5715 syntax_error_unexpected_ch('(');
5718 /* it is "word(..." or "word (..." */
5720 ch = i_getch(input);
5721 while (ch == ' ' || ch == '\t');
5723 syntax_error_unexpected_ch(ch);
5726 nommu_addchr(&ctx->as_string, ch);
5728 ch = i_getch(input);
5729 while (ch == ' ' || ch == '\t' || ch == '\n');
5731 syntax_error_unexpected_ch(ch);
5734 nommu_addchr(&ctx->as_string, ch);
5735 command->cmd_type = CMD_FUNCDEF;
5740 #if 0 /* Prevented by caller */
5741 if (command->argv /* word [word]{... */
5742 || dest->length /* word{... */
5743 || dest->o_quoted /* ""{... */
5746 debug_printf_parse("parse_group return 1: "
5747 "syntax error, groups and arglists don't mix\n");
5752 #if ENABLE_HUSH_FUNCTIONS
5758 command->cmd_type = CMD_SUBSHELL;
5760 /* bash does not allow "{echo...", requires whitespace */
5761 ch = i_getch(input);
5762 if (ch != ' ' && ch != '\t' && ch != '\n') {
5763 syntax_error_unexpected_ch(ch);
5766 nommu_addchr(&ctx->as_string, ch);
5771 char *as_string = NULL;
5773 pipe_list = parse_stream(&as_string, input, endch);
5776 o_addstr(&ctx->as_string, as_string);
5778 /* empty ()/{} or parse error? */
5779 if (!pipe_list || pipe_list == ERR_PTR) {
5780 /* parse_stream already emitted error msg */
5784 debug_printf_parse("parse_group return 1: "
5785 "parse_stream returned %p\n", pipe_list);
5788 command->group = pipe_list;
5790 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5791 command->group_as_string = as_string;
5792 debug_printf_parse("end of group, remembering as:'%s'\n",
5793 command->group_as_string);
5796 debug_printf_parse("parse_group return 0\n");
5798 /* command remains "open", available for possible redirects */
5801 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5802 /* Subroutines for copying $(...) and `...` things */
5803 static void add_till_backquote(o_string *dest, struct in_str *input);
5805 static void add_till_single_quote(o_string *dest, struct in_str *input)
5808 int ch = i_getch(input);
5810 syntax_error_unterm_ch('\'');
5811 /*xfunc_die(); - redundant */
5818 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5819 static void add_till_double_quote(o_string *dest, struct in_str *input)
5822 int ch = i_getch(input);
5824 syntax_error_unterm_ch('"');
5825 /*xfunc_die(); - redundant */
5829 if (ch == '\\') { /* \x. Copy both chars. */
5831 ch = i_getch(input);
5835 add_till_backquote(dest, input);
5839 //if (ch == '$') ...
5842 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5844 * "Within the backquoted style of command substitution, backslash
5845 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5846 * The search for the matching backquote shall be satisfied by the first
5847 * backquote found without a preceding backslash; during this search,
5848 * if a non-escaped backquote is encountered within a shell comment,
5849 * a here-document, an embedded command substitution of the $(command)
5850 * form, or a quoted string, undefined results occur. A single-quoted
5851 * or double-quoted string that begins, but does not end, within the
5852 * "`...`" sequence produces undefined results."
5854 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5856 static void add_till_backquote(o_string *dest, struct in_str *input)
5859 int ch = i_getch(input);
5861 syntax_error_unterm_ch('`');
5862 /*xfunc_die(); - redundant */
5867 /* \x. Copy both chars unless it is \` */
5868 int ch2 = i_getch(input);
5870 syntax_error_unterm_ch('`');
5871 /*xfunc_die(); - redundant */
5873 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5880 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5881 * quoting and nested ()s.
5882 * "With the $(command) style of command substitution, all characters
5883 * following the open parenthesis to the matching closing parenthesis
5884 * constitute the command. Any valid shell script can be used for command,
5885 * except a script consisting solely of redirections which produces
5886 * unspecified results."
5888 * echo $(echo '(TEST)' BEST) (TEST) BEST
5889 * echo $(echo 'TEST)' BEST) TEST) BEST
5890 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5892 * Also adapted to eat ${var%...} constructs, since ... part
5893 * can contain arbitrary constructs, just like $(cmd).
5895 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
5896 static void add_till_closing_paren(o_string *dest, struct in_str *input, char end_ch)
5898 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
5899 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG-1);
5901 int ch = i_getch(input);
5903 syntax_error_unterm_ch(end_ch);
5904 /*xfunc_die(); - redundant */
5909 /* we look for closing )) of $((EXPR)) */
5910 if (i_peek(input) == end_ch) {
5911 i_getch(input); /* eat second ')' */
5916 if (ch == '(' || ch == '{') {
5917 ch = (ch == '(' ? ')' : '}');
5918 add_till_closing_paren(dest, input, ch);
5923 add_till_single_quote(dest, input);
5928 add_till_double_quote(dest, input);
5933 add_till_backquote(dest, input);
5938 /* \x. Copy verbatim. Important for \(, \) */
5939 ch = i_getch(input);
5941 syntax_error_unterm_ch(')');
5942 /*xfunc_die(); - redundant */
5949 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5951 /* Return code: 0 for OK, 1 for syntax error */
5953 #define handle_dollar(as_string, dest, input) \
5954 handle_dollar(dest, input)
5956 static int handle_dollar(o_string *as_string,
5958 struct in_str *input)
5960 int ch = i_peek(input); /* first character after the $ */
5961 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5963 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5965 ch = i_getch(input);
5966 nommu_addchr(as_string, ch);
5968 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5970 debug_printf_parse(": '%c'\n", ch);
5971 o_addchr(dest, ch | quote_mask);
5974 if (!isalnum(ch) && ch != '_')
5976 ch = i_getch(input);
5977 nommu_addchr(as_string, ch);
5979 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5980 } else if (isdigit(ch)) {
5982 ch = i_getch(input);
5983 nommu_addchr(as_string, ch);
5984 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5985 debug_printf_parse(": '%c'\n", ch);
5986 o_addchr(dest, ch | quote_mask);
5987 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5988 } else switch (ch) {
5990 case '!': /* last bg pid */
5991 case '?': /* last exit code */
5992 case '#': /* number of args */
5993 case '*': /* args */
5994 case '@': /* args */
5995 goto make_one_char_var;
5997 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5999 ch = i_getch(input); /* eat '{' */
6000 nommu_addchr(as_string, ch);
6002 ch = i_getch(input); /* first char after '{' */
6003 nommu_addchr(as_string, ch);
6004 /* It should be ${?}, or ${#var},
6005 * or even ${?+subst} - operator acting on a special variable,
6006 * or the beginning of variable name.
6008 if (!strchr("$!?#*@_", ch) && !isalnum(ch)) { /* not one of those */
6010 syntax_error_unterm_str("${name}");
6011 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
6016 /* It's possible to just call add_till_closing_paren() at this point.
6017 * However, this regresses some of our testsuite cases
6018 * which check invalid constructs like ${%}.
6019 * Oh well... let's check that the var name part is fine... */
6023 debug_printf_parse(": '%c'\n", ch);
6025 ch = i_getch(input);
6026 nommu_addchr(as_string, ch);
6030 if (!isalnum(ch) && ch != '_') {
6031 /* handle parameter expansions
6032 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6034 if (!strchr("%#:-=+?", ch)) /* ${var<bad_char>... */
6035 goto bad_dollar_syntax;
6036 /* Eat everything until closing '}' */
6038 //TODO: add nommu_addchr hack here
6039 add_till_closing_paren(dest, input, '}');
6043 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6046 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6051 ch = i_getch(input);
6052 nommu_addchr(as_string, ch);
6053 # if ENABLE_SH_MATH_SUPPORT
6054 if (i_peek(input) == '(') {
6055 ch = i_getch(input);
6056 nommu_addchr(as_string, ch);
6057 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6058 o_addchr(dest, /*quote_mask |*/ '+');
6062 add_till_closing_paren(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
6065 o_addstr(as_string, dest->data + pos);
6066 o_addchr(as_string, ')');
6067 o_addchr(as_string, ')');
6070 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6074 # if ENABLE_HUSH_TICK
6075 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6076 o_addchr(dest, quote_mask | '`');
6080 add_till_closing_paren(dest, input, ')');
6083 o_addstr(as_string, dest->data + pos);
6084 o_addchr(as_string, ')');
6087 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6093 ch = i_getch(input);
6094 nommu_addchr(as_string, ch);
6096 if (isalnum(ch)) { /* it's $_name or $_123 */
6101 /* TODO: $_ and $-: */
6102 /* $_ Shell or shell script name; or last argument of last command
6103 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6104 * but in command's env, set to full pathname used to invoke it */
6105 /* $- Option flags set by set builtin or shell options (-i etc) */
6107 o_addQchr(dest, '$');
6109 debug_printf_parse("handle_dollar return 0\n");
6114 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6115 parse_stream_dquoted(dest, input, dquote_end)
6117 static int parse_stream_dquoted(o_string *as_string,
6119 struct in_str *input,
6126 ch = i_getch(input);
6128 nommu_addchr(as_string, ch);
6129 if (ch == dquote_end) { /* may be only '"' or EOF */
6130 if (dest->o_assignment == NOT_ASSIGNMENT)
6131 dest->o_escape ^= 1;
6132 debug_printf_parse("parse_stream_dquoted return 0\n");
6135 /* note: can't move it above ch == dquote_end check! */
6137 syntax_error_unterm_ch('"');
6138 /*xfunc_die(); - redundant */
6142 next = i_peek(input);
6144 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6145 ch, ch, dest->o_escape);
6148 syntax_error("\\<eof>");
6152 * "The backslash retains its special meaning [in "..."]
6153 * only when followed by one of the following characters:
6154 * $, `, ", \, or <newline>. A double quote may be quoted
6155 * within double quotes by preceding it with a backslash."
6157 if (strchr("$`\"\\\n", next) != NULL) {
6158 ch = i_getch(input);
6160 o_addqchr(dest, ch);
6161 nommu_addchr(as_string, ch);
6164 o_addqchr(dest, '\\');
6165 nommu_addchr(as_string, '\\');
6170 if (handle_dollar(as_string, dest, input) != 0) {
6171 debug_printf_parse("parse_stream_dquoted return 1: "
6172 "handle_dollar returned non-0\n");
6177 #if ENABLE_HUSH_TICK
6179 //int pos = dest->length;
6180 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6181 o_addchr(dest, 0x80 | '`');
6182 add_till_backquote(dest, input);
6183 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6184 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6188 o_addQchr(dest, ch);
6190 && (dest->o_assignment == MAYBE_ASSIGNMENT
6191 || dest->o_assignment == WORD_IS_KEYWORD)
6192 && is_well_formed_var_name(dest->data, '=')
6194 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6200 * Scan input until EOF or end_trigger char.
6201 * Return a list of pipes to execute, or NULL on EOF
6202 * or if end_trigger character is met.
6203 * On syntax error, exit is shell is not interactive,
6204 * reset parsing machinery and start parsing anew,
6205 * or return ERR_PTR.
6207 static struct pipe *parse_stream(char **pstring,
6208 struct in_str *input,
6211 struct parse_context ctx;
6212 o_string dest = NULL_O_STRING;
6216 /* Double-quote state is handled in the state variable is_in_dquote.
6217 * A single-quote triggers a bypass of the main loop until its mate is
6218 * found. When recursing, quote state is passed in via dest->o_escape.
6220 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6221 end_trigger ? end_trigger : 'X');
6224 /* If very first arg is "" or '', dest.data may end up NULL.
6225 * Preventing this: */
6226 o_addchr(&dest, '\0');
6229 G.ifs = get_local_var_value("IFS");
6234 #if ENABLE_HUSH_INTERACTIVE
6235 input->promptmode = 0; /* PS1 */
6237 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6238 initialize_context(&ctx);
6243 const char *is_special;
6247 redir_type redir_style;
6250 /* dest.o_quoted = 1; - already is (see below) */
6251 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6254 /* We reached closing '"' */
6257 ch = i_getch(input);
6258 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6259 ch, ch, dest.o_escape);
6264 syntax_error_unterm_str("here document");
6267 /* end_trigger == '}' case errors out earlier,
6268 * checking only ')' */
6269 if (end_trigger == ')') {
6270 syntax_error_unterm_ch('('); /* exits */
6271 /* goto parse_error; */
6274 if (done_word(&dest, &ctx)) {
6278 done_pipe(&ctx, PIPE_SEQ);
6280 /* If we got nothing... */
6281 /* (this makes bare "&" cmd a no-op.
6282 * bash says: "syntax error near unexpected token '&'") */
6283 if (pi->num_cmds == 0
6284 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6290 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6292 *pstring = ctx.as_string.data;
6294 o_free_unsafe(&ctx.as_string);
6297 debug_printf_parse("parse_stream return %p\n", pi);
6300 nommu_addchr(&ctx.as_string, ch);
6304 next = i_peek(input);
6306 is_special = "{}<>;&|()#'" /* special outside of "str" */
6307 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6308 /* Are { and } special here? */
6309 if (ctx.command->argv /* word [word]{... - non-special */
6310 || dest.length /* word{... - non-special */
6311 || dest.o_quoted /* ""{... - non-special */
6312 || (next != ';' /* }; - special */
6313 && next != ')' /* }) - special */
6314 && next != '&' /* }& and }&& ... - special */
6315 && next != '|' /* }|| ... - special */
6316 && !strchr(G.ifs, next) /* {word - non-special */
6319 /* They are not special, skip "{}" */
6322 is_special = strchr(is_special, ch);
6323 is_ifs = strchr(G.ifs, ch);
6325 if (!is_special && !is_ifs) { /* ordinary char */
6327 o_addQchr(&dest, ch);
6328 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6329 || dest.o_assignment == WORD_IS_KEYWORD)
6331 && is_well_formed_var_name(dest.data, '=')
6333 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6339 if (done_word(&dest, &ctx)) {
6343 #if ENABLE_HUSH_CASE
6344 /* "case ... in <newline> word) ..." -
6345 * newlines are ignored (but ';' wouldn't be) */
6346 if (ctx.command->argv == NULL
6347 && ctx.ctx_res_w == RES_MATCH
6352 /* Treat newline as a command separator. */
6353 done_pipe(&ctx, PIPE_SEQ);
6354 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6356 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6361 dest.o_assignment = MAYBE_ASSIGNMENT;
6363 /* note: if (is_ifs) continue;
6364 * will still trigger for us */
6368 /* "cmd}" or "cmd }..." without semicolon or &:
6369 * } is an ordinary char in this case, even inside { cmd; }
6370 * Pathological example: { ""}; } should exec "}" cmd
6373 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6374 || dest.length != 0 /* word} */
6375 || dest.o_quoted /* ""} */
6379 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6380 goto skip_end_trigger;
6381 /* else: } does terminate a group */
6384 if (end_trigger && end_trigger == ch
6385 && (ch != ';' || heredoc_cnt == 0)
6386 #if ENABLE_HUSH_CASE
6388 || ctx.ctx_res_w != RES_MATCH
6389 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6394 /* This is technically valid:
6395 * { cat <<HERE; }; echo Ok
6399 * but we don't support this.
6400 * We require heredoc to be in enclosing {}/(),
6403 syntax_error_unterm_str("here document");
6406 if (done_word(&dest, &ctx)) {
6409 done_pipe(&ctx, PIPE_SEQ);
6410 dest.o_assignment = MAYBE_ASSIGNMENT;
6411 /* Do we sit outside of any if's, loops or case's? */
6413 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6417 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6419 *pstring = ctx.as_string.data;
6421 o_free_unsafe(&ctx.as_string);
6424 debug_printf_parse("parse_stream return %p: "
6425 "end_trigger char found\n",
6427 return ctx.list_head;
6434 /* Catch <, > before deciding whether this word is
6435 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6438 redir_fd = redirect_opt_num(&dest);
6439 if (done_word(&dest, &ctx)) {
6442 redir_style = REDIRECT_OVERWRITE;
6444 redir_style = REDIRECT_APPEND;
6445 ch = i_getch(input);
6446 nommu_addchr(&ctx.as_string, ch);
6449 else if (next == '(') {
6450 syntax_error(">(process) not supported");
6454 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6456 continue; /* back to top of while (1) */
6458 redir_fd = redirect_opt_num(&dest);
6459 if (done_word(&dest, &ctx)) {
6462 redir_style = REDIRECT_INPUT;
6464 redir_style = REDIRECT_HEREDOC;
6466 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6467 ch = i_getch(input);
6468 nommu_addchr(&ctx.as_string, ch);
6469 } else if (next == '>') {
6470 redir_style = REDIRECT_IO;
6471 ch = i_getch(input);
6472 nommu_addchr(&ctx.as_string, ch);
6475 else if (next == '(') {
6476 syntax_error("<(process) not supported");
6480 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6482 continue; /* back to top of while (1) */
6485 if (dest.o_assignment == MAYBE_ASSIGNMENT
6486 /* check that we are not in word in "a=1 2>word b=1": */
6487 && !ctx.pending_redirect
6489 /* ch is a special char and thus this word
6490 * cannot be an assignment */
6491 dest.o_assignment = NOT_ASSIGNMENT;
6494 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6498 if (dest.length == 0) {
6501 if (ch == EOF || ch == '\n')
6504 /* note: we do not add it to &ctx.as_string */
6506 nommu_addchr(&ctx.as_string, '\n');
6508 o_addQchr(&dest, ch);
6513 syntax_error("\\<eof>");
6516 ch = i_getch(input);
6518 o_addchr(&dest, '\\');
6519 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6520 o_addchr(&dest, ch);
6521 nommu_addchr(&ctx.as_string, ch);
6522 /* Example: echo Hello \2>file
6523 * we need to know that word 2 is quoted */
6528 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6529 ctx.as_string.data[--ctx.as_string.length] = '\0';
6534 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6535 debug_printf_parse("parse_stream parse error: "
6536 "handle_dollar returned non-0\n");
6543 ch = i_getch(input);
6545 syntax_error_unterm_ch('\'');
6546 /*xfunc_die(); - redundant */
6548 nommu_addchr(&ctx.as_string, ch);
6551 o_addqchr(&dest, ch);
6556 is_in_dquote ^= 1; /* invert */
6557 if (dest.o_assignment == NOT_ASSIGNMENT)
6560 #if ENABLE_HUSH_TICK
6565 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6566 o_addchr(&dest, '`');
6570 add_till_backquote(&dest, input);
6572 o_addstr(&ctx.as_string, dest.data + pos);
6573 o_addchr(&ctx.as_string, '`');
6575 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6576 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6581 #if ENABLE_HUSH_CASE
6584 if (done_word(&dest, &ctx)) {
6587 done_pipe(&ctx, PIPE_SEQ);
6588 #if ENABLE_HUSH_CASE
6589 /* Eat multiple semicolons, detect
6590 * whether it means something special */
6595 ch = i_getch(input);
6596 nommu_addchr(&ctx.as_string, ch);
6597 if (ctx.ctx_res_w == RES_CASE_BODY) {
6598 ctx.ctx_dsemicolon = 1;
6599 ctx.ctx_res_w = RES_MATCH;
6605 /* We just finished a cmd. New one may start
6606 * with an assignment */
6607 dest.o_assignment = MAYBE_ASSIGNMENT;
6610 if (done_word(&dest, &ctx)) {
6614 ch = i_getch(input);
6615 nommu_addchr(&ctx.as_string, ch);
6616 done_pipe(&ctx, PIPE_AND);
6618 done_pipe(&ctx, PIPE_BG);
6622 if (done_word(&dest, &ctx)) {
6625 #if ENABLE_HUSH_CASE
6626 if (ctx.ctx_res_w == RES_MATCH)
6627 break; /* we are in case's "word | word)" */
6629 if (next == '|') { /* || */
6630 ch = i_getch(input);
6631 nommu_addchr(&ctx.as_string, ch);
6632 done_pipe(&ctx, PIPE_OR);
6634 /* we could pick up a file descriptor choice here
6635 * with redirect_opt_num(), but bash doesn't do it.
6636 * "echo foo 2| cat" yields "foo 2". */
6639 o_reset_to_empty_unquoted(&ctx.as_string);
6644 #if ENABLE_HUSH_CASE
6645 /* "case... in [(]word)..." - skip '(' */
6646 if (ctx.ctx_res_w == RES_MATCH
6647 && ctx.command->argv == NULL /* not (word|(... */
6648 && dest.length == 0 /* not word(... */
6649 && dest.o_quoted == 0 /* not ""(... */
6655 if (parse_group(&dest, &ctx, input, ch) != 0) {
6660 #if ENABLE_HUSH_CASE
6661 if (ctx.ctx_res_w == RES_MATCH)
6665 /* proper use of this character is caught by end_trigger:
6666 * if we see {, we call parse_group(..., end_trigger='}')
6667 * and it will match } earlier (not here). */
6668 syntax_error_unexpected_ch(ch);
6672 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6678 struct parse_context *pctx;
6679 IF_HAS_KEYWORDS(struct parse_context *p2;)
6681 /* Clean up allocated tree.
6682 * Sample for finding leaks on syntax error recovery path.
6683 * Run it from interactive shell, watch pmap `pidof hush`.
6684 * while if false; then false; fi; do break; fi
6685 * Samples to catch leaks at execution:
6686 * while if (true | {true;}); then echo ok; fi; do break; done
6687 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6691 /* Update pipe/command counts,
6692 * otherwise freeing may miss some */
6693 done_pipe(pctx, PIPE_SEQ);
6694 debug_printf_clean("freeing list %p from ctx %p\n",
6695 pctx->list_head, pctx);
6696 debug_print_tree(pctx->list_head, 0);
6697 free_pipe_list(pctx->list_head);
6698 debug_printf_clean("freed list %p\n", pctx->list_head);
6700 o_free_unsafe(&pctx->as_string);
6702 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6706 IF_HAS_KEYWORDS(pctx = p2;)
6707 } while (HAS_KEYWORDS && pctx);
6708 /* Free text, clear all dest fields */
6710 /* If we are not in top-level parse, we return,
6711 * our caller will propagate error.
6713 if (end_trigger != ';') {
6721 /* Discard cached input, force prompt */
6723 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6728 /* Executing from string: eval, sh -c '...'
6729 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6730 * end_trigger controls how often we stop parsing
6731 * NUL: parse all, execute, return
6732 * ';': parse till ';' or newline, execute, repeat till EOF
6734 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6736 /* Why we need empty flag?
6737 * An obscure corner case "false; ``; echo $?":
6738 * empty command in `` should still set $? to 0.
6739 * But we can't just set $? to 0 at the start,
6740 * this breaks "false; echo `echo $?`" case.
6744 struct pipe *pipe_list;
6746 pipe_list = parse_stream(NULL, inp, end_trigger);
6747 if (!pipe_list) { /* EOF */
6749 G.last_exitcode = 0;
6752 debug_print_tree(pipe_list, 0);
6753 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6754 run_and_free_list(pipe_list);
6759 static void parse_and_run_string(const char *s)
6761 struct in_str input;
6762 setup_string_in_str(&input, s);
6763 parse_and_run_stream(&input, '\0');
6766 static void parse_and_run_file(FILE *f)
6768 struct in_str input;
6769 setup_file_in_str(&input, f);
6770 parse_and_run_stream(&input, ';');
6773 /* Called a few times only (or even once if "sh -c") */
6774 static void init_sigmasks(void)
6778 sigset_t old_blocked_set;
6780 if (!G.inherited_set_is_saved) {
6781 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6782 G.inherited_set = G.blocked_set;
6784 old_blocked_set = G.blocked_set;
6786 mask = (1 << SIGQUIT);
6787 if (G_interactive_fd) {
6788 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6789 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6790 mask |= SPECIAL_JOB_SIGS;
6792 G.non_DFL_mask = mask;
6797 sigaddset(&G.blocked_set, sig);
6801 sigdelset(&G.blocked_set, SIGCHLD);
6803 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6804 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6806 /* POSIX allows shell to re-enable SIGCHLD
6807 * even if it was SIG_IGN on entry */
6808 #if ENABLE_HUSH_FAST
6809 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6810 if (!G.inherited_set_is_saved)
6811 signal(SIGCHLD, SIGCHLD_handler);
6813 if (!G.inherited_set_is_saved)
6814 signal(SIGCHLD, SIG_DFL);
6817 G.inherited_set_is_saved = 1;
6822 static void maybe_set_to_sigexit(int sig)
6824 void (*handler)(int);
6825 /* non_DFL_mask'ed signals are, well, masked,
6826 * no need to set handler for them.
6828 if (!((G.non_DFL_mask >> sig) & 1)) {
6829 handler = signal(sig, sigexit);
6830 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6831 signal(sig, handler);
6834 /* Set handlers to restore tty pgrp and exit */
6835 static void set_fatal_handlers(void)
6837 /* We _must_ restore tty pgrp on fatal signals */
6839 maybe_set_to_sigexit(SIGILL );
6840 maybe_set_to_sigexit(SIGFPE );
6841 maybe_set_to_sigexit(SIGBUS );
6842 maybe_set_to_sigexit(SIGSEGV);
6843 maybe_set_to_sigexit(SIGTRAP);
6844 } /* else: hush is perfect. what SEGV? */
6845 maybe_set_to_sigexit(SIGABRT);
6846 /* bash 3.2 seems to handle these just like 'fatal' ones */
6847 maybe_set_to_sigexit(SIGPIPE);
6848 maybe_set_to_sigexit(SIGALRM);
6849 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6850 * if we aren't interactive... but in this case
6851 * we never want to restore pgrp on exit, and this fn is not called */
6852 /*maybe_set_to_sigexit(SIGHUP );*/
6853 /*maybe_set_to_sigexit(SIGTERM);*/
6854 /*maybe_set_to_sigexit(SIGINT );*/
6858 static int set_mode(const char cstate, const char mode)
6860 int state = (cstate == '-' ? 1 : 0);
6862 case 'n': G.fake_mode = state; break;
6863 case 'x': /*G.debug_mode = state;*/ break;
6864 default: return EXIT_FAILURE;
6866 return EXIT_SUCCESS;
6869 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6870 int hush_main(int argc, char **argv)
6872 static const struct variable const_shell_ver = {
6874 .varstr = (char*)hush_version_str,
6875 .max_len = 1, /* 0 can provoke free(name) */
6880 unsigned builtin_argc;
6882 struct variable *cur_var;
6885 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6886 G.last_exitcode = EXIT_SUCCESS;
6888 G.argv0_for_re_execing = argv[0];
6890 /* Deal with HUSH_VERSION */
6891 G.shell_ver = const_shell_ver; /* copying struct here */
6892 G.top_var = &G.shell_ver;
6893 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6894 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6895 /* Initialize our shell local variables with the values
6896 * currently living in the environment */
6897 cur_var = G.top_var;
6900 char *value = strchr(*e, '=');
6901 if (value) { /* paranoia */
6902 cur_var->next = xzalloc(sizeof(*cur_var));
6903 cur_var = cur_var->next;
6904 cur_var->varstr = *e;
6905 cur_var->max_len = strlen(*e);
6906 cur_var->flg_export = 1;
6910 /* reinstate HUSH_VERSION */
6911 debug_printf_env("putenv '%s'\n", hush_version_str);
6912 putenv((char *)hush_version_str);
6915 set_pwd_var(/*exp:*/ 1);
6916 /* bash also exports SHLVL and _,
6917 * and sets (but doesn't export) the following variables:
6919 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6920 * BASH_VERSION='3.2.0(1)-release'
6922 * MACHTYPE=i386-pc-linux-gnu
6924 * HOSTNAME=<xxxxxxxxxx>
6925 * PPID=<NNNNN> - we also do it elsewhere
6936 * PIPESTATUS=([0]="0")
6937 * HISTFILE=/<xxx>/.bash_history
6941 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6943 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6953 #if ENABLE_FEATURE_EDITING
6954 G.line_input_state = new_line_input_t(FOR_SHELL);
6956 G.global_argc = argc;
6957 G.global_argv = argv;
6958 /* Initialize some more globals to non-zero values */
6959 cmdedit_update_prompt();
6961 if (setjmp(die_jmp)) {
6962 /* xfunc has failed! die die die */
6963 /* no EXIT traps, this is an escape hatch! */
6965 hush_exit(xfunc_error_retval);
6968 /* Shell is non-interactive at first. We need to call
6969 * init_sigmasks() if we are going to execute "sh <script>",
6970 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6971 * If we later decide that we are interactive, we run init_sigmasks()
6972 * in order to intercept (more) signals.
6976 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6979 opt = getopt(argc, argv, "+c:xins"
6982 # if ENABLE_HUSH_FUNCTIONS
6992 * sh ... -c 'script'
6993 * sh ... -c 'script' ARG0 [ARG1...]
6994 * On NOMMU, if builtin_argc != 0,
6995 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
6996 * "" needs to be replaced with NULL
6997 * and BARGV vector fed to builtin function.
6998 * Note: the form without ARG0 never happens:
6999 * sh ... -c 'builtin' BARGV... ""
7002 G.root_pid = getpid();
7003 G.root_ppid = getppid();
7005 G.global_argv = argv + optind;
7006 G.global_argc = argc - optind;
7008 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7009 const struct built_in_command *x;
7012 x = find_builtin(optarg);
7013 if (x) { /* paranoia */
7014 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7015 G.global_argv += builtin_argc;
7016 G.global_argv[-1] = NULL; /* replace "" */
7017 G.last_exitcode = x->b_function(argv + optind - 1);
7021 if (!G.global_argv[0]) {
7022 /* -c 'script' (no params): prevent empty $0 */
7023 G.global_argv--; /* points to argv[i] of 'script' */
7024 G.global_argv[0] = argv[0];
7026 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7028 parse_and_run_string(optarg);
7031 /* Well, we cannot just declare interactiveness,
7032 * we have to have some stuff (ctty, etc) */
7033 /* G_interactive_fd++; */
7036 /* "-s" means "read from stdin", but this is how we always
7037 * operate, so simply do nothing here. */
7040 case '<': /* "big heredoc" support */
7041 full_write(STDOUT_FILENO, optarg, strlen(optarg));
7044 unsigned long long empty_trap_mask;
7046 G.root_pid = bb_strtou(optarg, &optarg, 16);
7048 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7050 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7052 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7054 builtin_argc = bb_strtou(optarg, &optarg, 16);
7056 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7057 if (empty_trap_mask != 0) {
7060 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7061 for (sig = 1; sig < NSIG; sig++) {
7062 if (empty_trap_mask & (1LL << sig)) {
7063 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7064 sigaddset(&G.blocked_set, sig);
7067 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7069 # if ENABLE_HUSH_LOOPS
7071 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7077 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7079 # if ENABLE_HUSH_FUNCTIONS
7081 struct function *funcp = new_function(optarg);
7082 /* funcp->name is already set to optarg */
7083 /* funcp->body is set to NULL. It's a special case. */
7084 funcp->body_as_string = argv[optind];
7092 if (!set_mode('-', opt))
7096 fprintf(stderr, "Usage: sh [FILE]...\n"
7097 " or: sh -c command [args]...\n\n");
7103 } /* option parsing loop */
7106 G.root_pid = getpid();
7107 G.root_ppid = getppid();
7110 /* If we are login shell... */
7111 if (argv[0] && argv[0][0] == '-') {
7113 debug_printf("sourcing /etc/profile\n");
7114 input = fopen_for_read("/etc/profile");
7115 if (input != NULL) {
7116 close_on_exec_on(fileno(input));
7118 parse_and_run_file(input);
7121 /* bash: after sourcing /etc/profile,
7122 * tries to source (in the given order):
7123 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7124 * stopping on first found. --noprofile turns this off.
7125 * bash also sources ~/.bash_logout on exit.
7126 * If called as sh, skips .bash_XXX files.
7133 * "bash <script>" (which is never interactive (unless -i?))
7134 * sources $BASH_ENV here (without scanning $PATH).
7135 * If called as sh, does the same but with $ENV.
7137 debug_printf("running script '%s'\n", argv[optind]);
7138 G.global_argv = argv + optind;
7139 G.global_argc = argc - optind;
7140 input = xfopen_for_read(argv[optind]);
7141 close_on_exec_on(fileno(input));
7143 parse_and_run_file(input);
7144 #if ENABLE_FEATURE_CLEAN_UP
7150 /* Up to here, shell was non-interactive. Now it may become one.
7151 * NB: don't forget to (re)run init_sigmasks() as needed.
7154 /* A shell is interactive if the '-i' flag was given,
7155 * or if all of the following conditions are met:
7157 * no arguments remaining or the -s flag given
7158 * standard input is a terminal
7159 * standard output is a terminal
7160 * Refer to Posix.2, the description of the 'sh' utility.
7163 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7164 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7165 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7166 if (G_saved_tty_pgrp < 0)
7167 G_saved_tty_pgrp = 0;
7169 /* try to dup stdin to high fd#, >= 255 */
7170 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7171 if (G_interactive_fd < 0) {
7172 /* try to dup to any fd */
7173 G_interactive_fd = dup(STDIN_FILENO);
7174 if (G_interactive_fd < 0) {
7176 G_interactive_fd = 0;
7177 G_saved_tty_pgrp = 0;
7180 // TODO: track & disallow any attempts of user
7181 // to (inadvertently) close/redirect G_interactive_fd
7183 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7184 if (G_interactive_fd) {
7185 close_on_exec_on(G_interactive_fd);
7187 if (G_saved_tty_pgrp) {
7188 /* If we were run as 'hush &', sleep until we are
7189 * in the foreground (tty pgrp == our pgrp).
7190 * If we get started under a job aware app (like bash),
7191 * make sure we are now in charge so we don't fight over
7192 * who gets the foreground */
7194 pid_t shell_pgrp = getpgrp();
7195 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7196 if (G_saved_tty_pgrp == shell_pgrp)
7198 /* send TTIN to ourself (should stop us) */
7199 kill(- shell_pgrp, SIGTTIN);
7203 /* Block some signals */
7206 if (G_saved_tty_pgrp) {
7207 /* Set other signals to restore saved_tty_pgrp */
7208 set_fatal_handlers();
7209 /* Put ourselves in our own process group
7210 * (bash, too, does this only if ctty is available) */
7211 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7212 /* Grab control of the terminal */
7213 tcsetpgrp(G_interactive_fd, getpid());
7215 /* -1 is special - makes xfuncs longjmp, not exit
7216 * (we reset die_sleep = 0 whereever we [v]fork) */
7217 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7221 #elif ENABLE_HUSH_INTERACTIVE
7222 /* No job control compiled in, only prompt/line editing */
7223 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7224 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7225 if (G_interactive_fd < 0) {
7226 /* try to dup to any fd */
7227 G_interactive_fd = dup(STDIN_FILENO);
7228 if (G_interactive_fd < 0)
7230 G_interactive_fd = 0;
7233 if (G_interactive_fd) {
7234 close_on_exec_on(G_interactive_fd);
7238 /* We have interactiveness code disabled */
7242 * if interactive but not a login shell, sources ~/.bashrc
7243 * (--norc turns this off, --rcfile <file> overrides)
7246 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7247 /* note: ash and hush share this string */
7248 printf("\n\n%s %s\n"
7249 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7252 "hush - the humble shell"
7256 parse_and_run_file(stdin);
7259 #if ENABLE_FEATURE_CLEAN_UP
7260 if (G.cwd != bb_msg_unknown)
7262 cur_var = G.top_var->next;
7264 struct variable *tmp = cur_var;
7265 if (!cur_var->max_len)
7266 free(cur_var->varstr);
7267 cur_var = cur_var->next;
7271 hush_exit(G.last_exitcode);
7276 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7277 int lash_main(int argc, char **argv)
7279 bb_error_msg("lash is deprecated, please use hush instead");
7280 return hush_main(argc, argv);
7285 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7286 int msh_main(int argc, char **argv)
7288 //bb_error_msg("msh is deprecated, please use hush instead");
7289 return hush_main(argc, argv);
7297 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7302 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7309 return applet_main_func(argc, argv - argc);
7312 static int FAST_FUNC builtin_test(char **argv)
7314 return run_applet_main(argv, test_main);
7317 static int FAST_FUNC builtin_echo(char **argv)
7319 return run_applet_main(argv, echo_main);
7323 static int FAST_FUNC builtin_printf(char **argv)
7325 return run_applet_main(argv, printf_main);
7329 static char **skip_dash_dash(char **argv)
7332 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7337 static int FAST_FUNC builtin_eval(char **argv)
7339 int rcode = EXIT_SUCCESS;
7341 argv = skip_dash_dash(argv);
7343 char *str = expand_strvec_to_string(argv);
7345 * eval "echo Hi; done" ("done" is syntax error):
7346 * "echo Hi" will not execute too.
7348 parse_and_run_string(str);
7350 rcode = G.last_exitcode;
7355 static int FAST_FUNC builtin_cd(char **argv)
7359 argv = skip_dash_dash(argv);
7361 if (newdir == NULL) {
7362 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7363 * bash says "bash: cd: HOME not set" and does nothing
7366 const char *home = get_local_var_value("HOME");
7367 newdir = home ? home : "/";
7369 if (chdir(newdir)) {
7370 /* Mimic bash message exactly */
7371 bb_perror_msg("cd: %s", newdir);
7372 return EXIT_FAILURE;
7374 /* Read current dir (get_cwd(1) is inside) and set PWD.
7375 * Note: do not enforce exporting. If PWD was unset or unexported,
7376 * set it again, but do not export. bash does the same.
7378 set_pwd_var(/*exp:*/ 0);
7379 return EXIT_SUCCESS;
7382 static int FAST_FUNC builtin_exec(char **argv)
7384 argv = skip_dash_dash(argv);
7385 if (argv[0] == NULL)
7386 return EXIT_SUCCESS; /* bash does this */
7388 /* Careful: we can end up here after [v]fork. Do not restore
7389 * tty pgrp then, only top-level shell process does that */
7390 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7391 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7393 /* TODO: if exec fails, bash does NOT exit! We do.
7394 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7395 * and tcsetpgrp, and this is inherently racy.
7397 execvp_or_die(argv);
7400 static int FAST_FUNC builtin_exit(char **argv)
7402 debug_printf_exec("%s()\n", __func__);
7404 /* interactive bash:
7405 * # trap "echo EEE" EXIT
7408 * There are stopped jobs.
7409 * (if there are _stopped_ jobs, running ones don't count)
7412 # EEE (then bash exits)
7414 * we can use G.exiting = -1 as indicator "last cmd was exit"
7417 /* note: EXIT trap is run by hush_exit */
7418 argv = skip_dash_dash(argv);
7419 if (argv[0] == NULL)
7420 hush_exit(G.last_exitcode);
7421 /* mimic bash: exit 123abc == exit 255 + error msg */
7422 xfunc_error_retval = 255;
7423 /* bash: exit -2 == exit 254, no error msg */
7424 hush_exit(xatoi(argv[0]) & 0xff);
7427 static void print_escaped(const char *s)
7432 const char *p = strchrnul(s, '\'');
7433 /* print 'xxxx', possibly just '' */
7434 printf("'%.*s'", (int)(p - s), s);
7439 /* s points to '; print "'''...'''" */
7441 do putchar('\''); while (*++s == '\'');
7446 #if !ENABLE_HUSH_LOCAL
7447 #define helper_export_local(argv, exp, lvl) \
7448 helper_export_local(argv, exp)
7450 static void helper_export_local(char **argv, int exp, int lvl)
7455 /* So far we do not check that name is valid (TODO?) */
7457 if (strchr(name, '=') == NULL) {
7458 struct variable *var;
7460 var = get_local_var(name);
7461 if (exp == -1) { /* unexporting? */
7462 /* export -n NAME (without =VALUE) */
7464 var->flg_export = 0;
7465 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7467 } /* else: export -n NOT_EXISTING_VAR: no-op */
7470 if (exp == 1) { /* exporting? */
7471 /* export NAME (without =VALUE) */
7473 var->flg_export = 1;
7474 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7475 putenv(var->varstr);
7479 /* Exporting non-existing variable.
7480 * bash does not put it in environment,
7481 * but remembers that it is exported,
7482 * and does put it in env when it is set later.
7483 * We just set it to "" and export. */
7484 /* Or, it's "local NAME" (without =VALUE).
7485 * bash sets the value to "". */
7486 name = xasprintf("%s=", name);
7488 /* (Un)exporting/making local NAME=VALUE */
7489 name = xstrdup(name);
7491 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7495 static int FAST_FUNC builtin_export(char **argv)
7497 unsigned opt_unexport;
7499 #if ENABLE_HUSH_EXPORT_N
7500 /* "!": do not abort on errors */
7501 opt_unexport = getopt32(argv, "!n");
7502 if (opt_unexport == (uint32_t)-1)
7503 return EXIT_FAILURE;
7510 if (argv[0] == NULL) {
7517 /* ash emits: export VAR='VAL'
7518 * bash: declare -x VAR="VAL"
7519 * we follow ash example */
7520 const char *s = *e++;
7521 const char *p = strchr(s, '=');
7523 if (!p) /* wtf? take next variable */
7526 printf("export %.*s", (int)(p - s) + 1, s);
7527 print_escaped(p + 1);
7531 /*fflush_all(); - done after each builtin anyway */
7533 return EXIT_SUCCESS;
7536 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7538 return EXIT_SUCCESS;
7541 #if ENABLE_HUSH_LOCAL
7542 static int FAST_FUNC builtin_local(char **argv)
7544 if (G.func_nest_level == 0) {
7545 bb_error_msg("%s: not in a function", argv[0]);
7546 return EXIT_FAILURE; /* bash compat */
7548 helper_export_local(argv, 0, G.func_nest_level);
7549 return EXIT_SUCCESS;
7553 static int FAST_FUNC builtin_trap(char **argv)
7559 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7564 /* No args: print all trapped */
7565 for (i = 0; i < NSIG; ++i) {
7568 print_escaped(G.traps[i]);
7569 /* note: bash adds "SIG", but only if invoked
7570 * as "bash". If called as "sh", or if set -o posix,
7571 * then it prints short signal names.
7572 * We are printing short names: */
7573 printf(" %s\n", get_signame(i));
7576 /*fflush_all(); - done after each builtin anyway */
7577 return EXIT_SUCCESS;
7581 /* If first arg is a number: reset all specified signals */
7582 sig = bb_strtou(*argv, NULL, 10);
7588 sig = get_signum(*argv++);
7589 if (sig < 0 || sig >= NSIG) {
7591 /* Mimic bash message exactly */
7592 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7597 G.traps[sig] = xstrdup(new_cmd);
7599 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7600 get_signame(sig), sig, G.traps[sig]);
7602 /* There is no signal for 0 (EXIT) */
7607 sigaddset(&G.blocked_set, sig);
7609 /* There was a trap handler, we are removing it
7610 * (if sig has non-DFL handling,
7611 * we don't need to do anything) */
7612 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7614 sigdelset(&G.blocked_set, sig);
7617 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7621 if (!argv[1]) { /* no second arg */
7622 bb_error_msg("trap: invalid arguments");
7623 return EXIT_FAILURE;
7626 /* First arg is "-": reset all specified to default */
7627 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7628 /* Everything else: set arg as signal handler
7629 * (includes "" case, which ignores signal) */
7630 if (argv[0][0] == '-') {
7631 if (argv[0][1] == '\0') { /* "-" */
7632 /* new_cmd remains NULL: "reset these sigs" */
7635 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7638 /* else: "-something", no special meaning */
7643 goto process_sig_list;
7646 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7647 static int FAST_FUNC builtin_type(char **argv)
7649 int ret = EXIT_SUCCESS;
7655 if (0) {} /* make conditional compile easier below */
7656 /*else if (find_alias(*argv))
7657 type = "an alias";*/
7658 #if ENABLE_HUSH_FUNCTIONS
7659 else if (find_function(*argv))
7660 type = "a function";
7662 else if (find_builtin(*argv))
7663 type = "a shell builtin";
7664 else if ((path = find_in_path(*argv)) != NULL)
7667 bb_error_msg("type: %s: not found", *argv);
7672 printf("%s is %s\n", *argv, type);
7680 /* built-in 'fg' and 'bg' handler */
7681 static int FAST_FUNC builtin_fg_bg(char **argv)
7686 if (!G_interactive_fd)
7687 return EXIT_FAILURE;
7689 /* If they gave us no args, assume they want the last backgrounded task */
7691 for (pi = G.job_list; pi; pi = pi->next) {
7692 if (pi->jobid == G.last_jobid) {
7696 bb_error_msg("%s: no current job", argv[0]);
7697 return EXIT_FAILURE;
7699 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7700 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7701 return EXIT_FAILURE;
7703 for (pi = G.job_list; pi; pi = pi->next) {
7704 if (pi->jobid == jobnum) {
7708 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7709 return EXIT_FAILURE;
7711 /* TODO: bash prints a string representation
7712 * of job being foregrounded (like "sleep 1 | cat") */
7713 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7714 /* Put the job into the foreground. */
7715 tcsetpgrp(G_interactive_fd, pi->pgrp);
7718 /* Restart the processes in the job */
7719 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7720 for (i = 0; i < pi->num_cmds; i++) {
7721 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7722 pi->cmds[i].is_stopped = 0;
7724 pi->stopped_cmds = 0;
7726 i = kill(- pi->pgrp, SIGCONT);
7728 if (errno == ESRCH) {
7729 delete_finished_bg_job(pi);
7730 return EXIT_SUCCESS;
7732 bb_perror_msg("kill (SIGCONT)");
7735 if (argv[0][0] == 'f') {
7737 return checkjobs_and_fg_shell(pi);
7739 return EXIT_SUCCESS;
7743 #if ENABLE_HUSH_HELP
7744 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7746 const struct built_in_command *x;
7749 "Built-in commands:\n"
7750 "------------------\n");
7751 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7753 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7756 return EXIT_SUCCESS;
7761 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7764 const char *status_string;
7766 for (job = G.job_list; job; job = job->next) {
7767 if (job->alive_cmds == job->stopped_cmds)
7768 status_string = "Stopped";
7770 status_string = "Running";
7772 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7774 return EXIT_SUCCESS;
7779 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7784 # ifdef M_TRIM_THRESHOLD
7785 /* Optional. Reduces probability of false positives */
7788 /* Crude attempt to find where "free memory" starts,
7789 * sans fragmentation. */
7791 l = (unsigned long)p;
7794 if (l < (unsigned long)p) l = (unsigned long)p;
7797 if (!G.memleak_value)
7798 G.memleak_value = l;
7800 l -= G.memleak_value;
7807 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7812 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7815 return EXIT_SUCCESS;
7818 static int FAST_FUNC builtin_read(char **argv)
7827 /* "!": do not abort on errors.
7828 * Option string must start with "sr" to match BUILTIN_READ_xxx
7830 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7831 if (read_flags == (uint32_t)-1)
7832 return EXIT_FAILURE;
7835 r = shell_builtin_read(set_local_var_from_halves,
7837 get_local_var_value("IFS"), /* can be NULL */
7845 if ((uintptr_t)r > 1) {
7846 bb_error_msg("%s", r);
7847 r = (char*)(uintptr_t)1;
7850 return (uintptr_t)r;
7853 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7854 * built-in 'set' handler
7856 * set [-abCefhmnuvx] [-o option] [argument...]
7857 * set [+abCefhmnuvx] [+o option] [argument...]
7858 * set -- [argument...]
7861 * Implementations shall support the options in both their hyphen and
7862 * plus-sign forms. These options can also be specified as options to sh.
7864 * Write out all variables and their values: set
7865 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7866 * Turn on the -x and -v options: set -xv
7867 * Unset all positional parameters: set --
7868 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7869 * Set the positional parameters to the expansion of x, even if x expands
7870 * with a leading '-' or '+': set -- $x
7872 * So far, we only support "set -- [argument...]" and some of the short names.
7874 static int FAST_FUNC builtin_set(char **argv)
7877 char **pp, **g_argv;
7878 char *arg = *++argv;
7882 for (e = G.top_var; e; e = e->next)
7884 return EXIT_SUCCESS;
7888 if (!strcmp(arg, "--")) {
7892 if (arg[0] != '+' && arg[0] != '-')
7894 for (n = 1; arg[n]; ++n)
7895 if (set_mode(arg[0], arg[n]))
7897 } while ((arg = *++argv) != NULL);
7898 /* Now argv[0] is 1st argument */
7901 return EXIT_SUCCESS;
7904 /* NB: G.global_argv[0] ($0) is never freed/changed */
7905 g_argv = G.global_argv;
7906 if (G.global_args_malloced) {
7912 G.global_args_malloced = 1;
7913 pp = xzalloc(sizeof(pp[0]) * 2);
7914 pp[0] = g_argv[0]; /* retain $0 */
7917 /* This realloc's G.global_argv */
7918 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7925 return EXIT_SUCCESS;
7927 /* Nothing known, so abort */
7929 bb_error_msg("set: %s: invalid option", arg);
7930 return EXIT_FAILURE;
7933 static int FAST_FUNC builtin_shift(char **argv)
7936 argv = skip_dash_dash(argv);
7940 if (n >= 0 && n < G.global_argc) {
7941 if (G.global_args_malloced) {
7944 free(G.global_argv[m++]);
7947 memmove(&G.global_argv[1], &G.global_argv[n+1],
7948 G.global_argc * sizeof(G.global_argv[0]));
7949 return EXIT_SUCCESS;
7951 return EXIT_FAILURE;
7954 static int FAST_FUNC builtin_source(char **argv)
7956 char *arg_path, *filename;
7959 #if ENABLE_HUSH_FUNCTIONS
7963 argv = skip_dash_dash(argv);
7966 /* bash says: "bash: .: filename argument required" */
7967 return 2; /* bash compat */
7970 if (!strchr(filename, '/')) {
7971 arg_path = find_in_path(filename);
7973 filename = arg_path;
7975 input = fopen_or_warn(filename, "r");
7978 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7979 return EXIT_FAILURE;
7981 close_on_exec_on(fileno(input));
7983 #if ENABLE_HUSH_FUNCTIONS
7984 sv_flg = G.flag_return_in_progress;
7985 /* "we are inside sourced file, ok to use return" */
7986 G.flag_return_in_progress = -1;
7988 save_and_replace_G_args(&sv, argv);
7990 parse_and_run_file(input);
7993 restore_G_args(&sv, argv);
7994 #if ENABLE_HUSH_FUNCTIONS
7995 G.flag_return_in_progress = sv_flg;
7998 return G.last_exitcode;
8001 static int FAST_FUNC builtin_umask(char **argv)
8007 argv = skip_dash_dash(argv);
8009 mode_t old_mask = mask;
8012 rc = bb_parse_mode(argv[0], &mask);
8017 * bash: umask: 'q': invalid symbolic mode operator
8018 * bash: umask: 999: octal number out of range
8020 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8025 printf("%04o\n", (unsigned) mask);
8026 /* fall through and restore mask which we set to 0 */
8030 return !rc; /* rc != 0 - success */
8033 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8034 static int FAST_FUNC builtin_unset(char **argv)
8039 /* "!": do not abort on errors */
8040 /* "+": stop at 1st non-option */
8041 opts = getopt32(argv, "!+vf");
8042 if (opts == (unsigned)-1)
8043 return EXIT_FAILURE;
8045 bb_error_msg("unset: -v and -f are exclusive");
8046 return EXIT_FAILURE;
8052 if (!(opts & 2)) { /* not -f */
8053 if (unset_local_var(*argv)) {
8054 /* unset <nonexistent_var> doesn't fail.
8055 * Error is when one tries to unset RO var.
8056 * Message was printed by unset_local_var. */
8060 #if ENABLE_HUSH_FUNCTIONS
8070 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8071 static int FAST_FUNC builtin_wait(char **argv)
8073 int ret = EXIT_SUCCESS;
8076 argv = skip_dash_dash(argv);
8077 if (argv[0] == NULL) {
8078 /* Don't care about wait results */
8079 /* Note 1: must wait until there are no more children */
8080 /* Note 2: must be interruptible */
8082 * $ sleep 3 & sleep 6 & wait
8087 * $ sleep 3 & sleep 6 & wait
8091 * ^C <-- after ~4 sec from keyboard
8094 sigaddset(&G.blocked_set, SIGCHLD);
8095 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8098 if (errno == ECHILD)
8100 /* Wait for SIGCHLD or any other signal of interest */
8101 /* sigtimedwait with infinite timeout: */
8102 sig = sigwaitinfo(&G.blocked_set, NULL);
8104 sig = check_and_run_traps(sig);
8105 if (sig && sig != SIGCHLD) { /* see note 2 */
8111 sigdelset(&G.blocked_set, SIGCHLD);
8112 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8116 /* This is probably buggy wrt interruptible-ness */
8118 pid_t pid = bb_strtou(*argv, NULL, 10);
8120 /* mimic bash message */
8121 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8122 return EXIT_FAILURE;
8124 if (waitpid(pid, &status, 0) == pid) {
8125 if (WIFSIGNALED(status))
8126 ret = 128 + WTERMSIG(status);
8127 else if (WIFEXITED(status))
8128 ret = WEXITSTATUS(status);
8132 bb_perror_msg("wait %s", *argv);
8141 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8142 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8145 def = bb_strtou(argv[1], NULL, 10);
8146 if (errno || def < def_min || argv[2]) {
8147 bb_error_msg("%s: bad arguments", argv[0]);
8155 #if ENABLE_HUSH_LOOPS
8156 static int FAST_FUNC builtin_break(char **argv)
8159 if (G.depth_of_loop == 0) {
8160 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8161 return EXIT_SUCCESS; /* bash compat */
8163 G.flag_break_continue++; /* BC_BREAK = 1 */
8165 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8166 if (depth == UINT_MAX)
8167 G.flag_break_continue = BC_BREAK;
8168 if (G.depth_of_loop < depth)
8169 G.depth_break_continue = G.depth_of_loop;
8171 return EXIT_SUCCESS;
8174 static int FAST_FUNC builtin_continue(char **argv)
8176 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8177 return builtin_break(argv);
8181 #if ENABLE_HUSH_FUNCTIONS
8182 static int FAST_FUNC builtin_return(char **argv)
8186 if (G.flag_return_in_progress != -1) {
8187 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8188 return EXIT_FAILURE; /* bash compat */
8191 G.flag_return_in_progress = 1;
8194 * out of range: wraps around at 256, does not error out
8195 * non-numeric param:
8196 * f() { false; return qwe; }; f; echo $?
8197 * bash: return: qwe: numeric argument required <== we do this
8198 * 255 <== we also do this
8200 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);