1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
45 * redirection of stdout+stderr: &> and >&
46 * brace expansion: one/{two,three,four}
47 * reserved words: function select
48 * advanced test: [[ ]]
49 * process substitution: <(list) and >(list)
52 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
53 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
54 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
56 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
57 * This is exactly equivalent to let "EXPR".
58 * $[EXPR]: synonym for $((EXPR))
61 * grep for "TODO" and fix (some of them are easy)
62 * special variables (done: PWD, PPID, RANDOM)
63 * follow IFS rules more precisely, including update semantics
64 * builtins mandated by standards we don't support:
65 * [un]alias, command, fc, getopts, newgrp, readonly, times
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 /* Expand all variable references in given string, adding words to list[]
2409 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2410 * to be filled). This routine is extremely tricky: has to deal with
2411 * variables/parameters with whitespace, $* and $@, and constructs like
2412 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2413 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2415 /* or_mask is either 0 (normal case) or 0x80 -
2416 * expansion of right-hand side of assignment == 1-element expand.
2417 * It will also do no globbing, and thus we must not backslash-quote!
2424 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2425 debug_print_list("expand_vars_to_list", output, n);
2426 n = o_save_ptr(output, n);
2427 debug_print_list("expand_vars_to_list[0]", output, n);
2429 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2432 char *dyn_val = NULL;
2433 const char *val = NULL;
2434 #if ENABLE_HUSH_TICK
2435 o_string subst_result = NULL_O_STRING;
2437 #if ENABLE_SH_MATH_SUPPORT
2438 char arith_buf[sizeof(arith_t)*3 + 2];
2440 o_addblock(output, arg, p - arg);
2441 debug_print_list("expand_vars_to_list[1]", output, n);
2443 p = strchr(p, SPECIAL_VAR_SYMBOL);
2445 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2446 /* "$@" is special. Even if quoted, it can still
2447 * expand to nothing (not even an empty string) */
2448 if ((first_ch & 0x7f) != '@')
2449 ored_ch |= first_ch;
2451 switch (first_ch & 0x7f) {
2452 /* Highest bit in first_ch indicates that var is double-quoted */
2454 val = utoa(G.root_pid);
2456 case '!': /* bg pid */
2457 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2459 case '?': /* exitcode */
2460 val = utoa(G.last_exitcode);
2462 case '#': /* argc */
2463 if (arg[1] != SPECIAL_VAR_SYMBOL)
2464 /* actually, it's a ${#var} */
2466 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2471 if (!G.global_argv[i])
2473 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2474 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2475 smallint sv = output->o_escape;
2476 /* unquoted var's contents should be globbed, so don't escape */
2477 output->o_escape = 0;
2478 while (G.global_argv[i]) {
2479 n = expand_on_ifs(output, n, G.global_argv[i]);
2480 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2481 if (G.global_argv[i++][0] && G.global_argv[i]) {
2482 /* this argv[] is not empty and not last:
2483 * put terminating NUL, start new word */
2484 o_addchr(output, '\0');
2485 debug_print_list("expand_vars_to_list[2]", output, n);
2486 n = o_save_ptr(output, n);
2487 debug_print_list("expand_vars_to_list[3]", output, n);
2490 output->o_escape = sv;
2492 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2493 * and in this case should treat it like '$*' - see 'else...' below */
2494 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2496 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2497 if (++i >= G.global_argc)
2499 o_addchr(output, '\0');
2500 debug_print_list("expand_vars_to_list[4]", output, n);
2501 n = o_save_ptr(output, n);
2503 } else { /* quoted $*: add as one word */
2505 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2506 if (!G.global_argv[++i])
2509 o_addchr(output, G.ifs[0]);
2513 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2514 /* "Empty variable", used to make "" etc to not disappear */
2518 #if ENABLE_HUSH_TICK
2519 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2522 /* Can't just stuff it into output o_string,
2523 * expanded result may need to be globbed
2524 * and $IFS-splitted */
2525 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2526 G.last_exitcode = process_command_subs(&subst_result, arg);
2527 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2528 val = subst_result.data;
2531 #if ENABLE_SH_MATH_SUPPORT
2532 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2533 arith_eval_hooks_t hooks;
2538 arg++; /* skip '+' */
2539 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2540 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2542 exp_str = expand_pseudo_dquoted(arg);
2543 hooks.lookupvar = get_local_var_value;
2544 hooks.setvar = set_local_var_from_halves;
2545 hooks.endofname = endofname;
2546 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2550 const char *msg = "error in arithmetic";
2553 msg = "exponent less than 0";
2556 msg = "divide by 0";
2559 msg = "expression recursion loop detected";
2564 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2565 sprintf(arith_buf, arith_t_fmt, res);
2570 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2573 char exp_len; /* '#' if it's ${#var} */
2575 char exp_save = exp_save; /* for compiler */
2576 char *exp_saveptr = exp_saveptr; /* points to expansion operator */
2577 char *exp_word = exp_word; /* for compiler */
2580 arg[0] = first_ch & 0x7f;
2582 /* prepare for expansions */
2585 if (exp_len == '#') {
2586 /* handle length expansion ${#var} */
2589 /* maybe handle parameter expansion */
2590 exp_saveptr = var + strcspn(var, "%#:-=+?");
2591 exp_save = *exp_saveptr;
2593 exp_word = exp_saveptr;
2594 if (exp_save == ':')
2596 exp_op = *exp_word++;
2597 *exp_saveptr = '\0';
2601 /* lookup the variable in question */
2602 if (isdigit(var[0])) {
2603 /* handle_dollar() should have vetted var for us */
2605 if (i < G.global_argc)
2606 val = G.global_argv[i];
2607 /* else val remains NULL: $N with too big N */
2609 val = get_local_var_value(var);
2611 /* handle any expansions */
2612 if (exp_len == '#') {
2613 debug_printf_expand("expand: length(%s)=", val);
2614 val = utoa(val ? strlen(val) : 0);
2615 debug_printf_expand("%s\n", val);
2616 } else if (exp_op) {
2617 if (exp_op == '%' || exp_op == '#') {
2618 /* Standard-mandated substring removal ops:
2619 * ${parameter%word} - remove smallest suffix pattern
2620 * ${parameter%%word} - remove largest suffix pattern
2621 * ${parameter#word} - remove smallest prefix pattern
2622 * ${parameter##word} - remove largest prefix pattern
2624 * Word is expanded to produce a glob pattern.
2625 * Then var's value is matched to it and matching part removed.
2630 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2631 if (exp_op == *exp_word) /* ## or %% */
2633 val = dyn_val = xstrdup(val);
2634 loc = scan(dyn_val, exp_word, match_at_left);
2635 if (match_at_left) /* # or ## */
2637 else if (loc) /* % or %% and match was found */
2640 } else if (!strchr("%#:-=+?"+3, exp_op)) {
2641 #if ENABLE_HUSH_BASH_COMPAT
2642 /* exp_op is ':' and next char isn't a subst operator.
2643 * Assuming it's ${var:[N][:M]} bashism.
2644 * TODO: N, M can be expressions similar to $((EXPR)): 2+2, 2+var etc
2647 unsigned len = INT_MAX;
2650 if (*exp_word != ':') /* not ${var::...} */
2651 beg = bb_strtou(exp_word, &end, 0);
2652 //bb_error_msg("beg:'%s'=%u end:'%s'", exp_word, beg, end);
2654 if (end[1] != '\0') /* not ${var:NUM:} */
2655 len = bb_strtou(end + 1, &end, 0);
2660 //bb_error_msg("len:%u end:'%s'", len, end);
2663 //bb_error_msg("from val:'%s'", val);
2664 if (len == 0 || !val || beg >= strlen(val))
2667 val = dyn_val = xstrndup(val + beg, len);
2668 //bb_error_msg("val:'%s'", val);
2672 die_if_script("malformed ${%s...}", var);
2675 } else { /* one of "-=+?" */
2676 /* Standard-mandated substitution ops:
2677 * ${var?word} - indicate error if unset
2678 * If var is unset, word (or a message indicating it is unset
2679 * if word is null) is written to standard error
2680 * and the shell exits with a non-zero exit status.
2681 * Otherwise, the value of var is substituted.
2682 * ${var-word} - use default value
2683 * If var is unset, word is substituted.
2684 * ${var=word} - assign and use default value
2685 * If var is unset, word is assigned to var.
2686 * In all cases, final value of var is substituted.
2687 * ${var+word} - use alternative value
2688 * If var is unset, null is substituted.
2689 * Otherwise, word is substituted.
2691 * Word is subjected to tilde expansion, parameter expansion,
2692 * command substitution, and arithmetic expansion.
2693 * If word is not needed, it is not expanded.
2695 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2696 * but also treat null var as if it is unset.
2698 int use_word = (!val || ((exp_save == ':') && !val[0]));
2700 use_word = !use_word;
2701 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2702 (exp_save == ':') ? "true" : "false", use_word);
2704 if (exp_op == '?') {
2705 //TODO: how interactive bash aborts expansion mid-command?
2706 /* mimic bash message */
2707 die_if_script("%s: %s",
2709 exp_word[0] ? exp_word : "parameter null or not set"
2715 if (exp_op == '=') {
2716 /* ${var=[word]} or ${var:=[word]} */
2717 if (isdigit(var[0]) || var[0] == '#') {
2718 /* mimic bash message */
2719 die_if_script("$%s: cannot assign in this way", var);
2722 char *new_var = xasprintf("%s=%s", var, val);
2723 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2729 *exp_saveptr = exp_save;
2733 #if ENABLE_HUSH_TICK
2736 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2737 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2739 /* unquoted var's contents should be globbed, so don't escape */
2740 smallint sv = output->o_escape;
2741 output->o_escape = 0;
2742 n = expand_on_ifs(output, n, val);
2744 output->o_escape = sv;
2746 } else { /* quoted $VAR, val will be appended below */
2747 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2750 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2753 o_addQstr(output, val, strlen(val));
2756 /* Do the check to avoid writing to a const string */
2757 if (*p != SPECIAL_VAR_SYMBOL)
2758 *p = SPECIAL_VAR_SYMBOL;
2760 #if ENABLE_HUSH_TICK
2761 o_free(&subst_result);
2764 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2767 debug_print_list("expand_vars_to_list[a]", output, n);
2768 /* this part is literal, and it was already pre-quoted
2769 * if needed (much earlier), do not use o_addQstr here! */
2770 o_addstr_with_NUL(output, arg);
2771 debug_print_list("expand_vars_to_list[b]", output, n);
2772 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2773 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2776 /* allow to reuse list[n] later without re-growth */
2777 output->has_empty_slot = 1;
2779 o_addchr(output, '\0');
2784 static char **expand_variables(char **argv, int or_mask)
2789 o_string output = NULL_O_STRING;
2791 if (or_mask & 0x100) {
2792 output.o_escape = 1; /* protect against globbing for "$var" */
2793 /* (unquoted $var will temporarily switch it off) */
2800 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2803 debug_print_list("expand_variables", &output, n);
2805 /* output.data (malloced in one block) gets returned in "list" */
2806 list = o_finalize_list(&output, n);
2807 debug_print_strings("expand_variables[1]", list);
2811 static char **expand_strvec_to_strvec(char **argv)
2813 return expand_variables(argv, 0x100);
2816 #if ENABLE_HUSH_BASH_COMPAT
2817 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2819 return expand_variables(argv, 0x80);
2823 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2824 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2829 o_string output = NULL_O_STRING;
2834 int is_var = is_well_formed_var_name(*v, '=');
2835 /* is_var * 0x80: singleword expansion for vars */
2836 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2838 /* Subtle! expand_vars_to_list did not glob last word yet.
2839 * It does this only when fed with further data.
2840 * Therefore we set globbing flags AFTER it, not before:
2843 /* if it is not recognizably abc=...; then: */
2844 output.o_escape = !is_var; /* protect against globbing for "$var" */
2845 /* (unquoted $var will temporarily switch it off) */
2846 output.o_glob = !is_var; /* and indeed do globbing */
2849 debug_print_list("expand_cond", &output, n);
2851 /* output.data (malloced in one block) gets returned in "list" */
2852 list = o_finalize_list(&output, n);
2853 debug_print_strings("expand_cond[1]", list);
2858 /* Used for expansion of right hand of assignments */
2859 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2861 static char *expand_string_to_string(const char *str)
2863 char *argv[2], **list;
2865 argv[0] = (char*)str;
2867 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2869 if (!list[0] || list[1])
2870 bb_error_msg_and_die("BUG in varexp2");
2871 /* actually, just move string 2*sizeof(char*) bytes back */
2872 overlapping_strcpy((char*)list, list[0]);
2873 unbackslash((char*)list);
2874 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2878 /* Used for "eval" builtin */
2879 static char* expand_strvec_to_string(char **argv)
2883 list = expand_variables(argv, 0x80);
2884 /* Convert all NULs to spaces */
2889 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2890 bb_error_msg_and_die("BUG in varexp3");
2891 /* bash uses ' ' regardless of $IFS contents */
2896 overlapping_strcpy((char*)list, list[0]);
2897 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2901 static char **expand_assignments(char **argv, int count)
2905 /* Expand assignments into one string each */
2906 for (i = 0; i < count; i++) {
2907 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2915 void re_execute_shell(char ***to_free, const char *s,
2916 char *g_argv0, char **g_argv,
2917 char **builtin_argv) NORETURN;
2919 static void reset_traps_to_defaults(void)
2921 /* This function is always called in a child shell
2922 * after fork (not vfork, NOMMU doesn't use this function).
2927 /* Child shells are not interactive.
2928 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2929 * Testcase: (while :; do :; done) + ^Z should background.
2930 * Same goes for SIGTERM, SIGHUP, SIGINT.
2932 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2933 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2935 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2936 * Stupid. It can be done with *single* &= op, but we can't use
2937 * the fact that G.blocked_set is implemented as a bitmask
2939 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2943 /* Careful. Only if no trap or trap is not "" */
2944 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2945 sigdelset(&G.blocked_set, sig);
2952 /* Our homegrown sig mask is saner to work with :) */
2953 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2955 /* Resetting all traps to default except empty ones */
2956 mask = G.non_DFL_mask;
2957 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2958 if (!G.traps[sig] || !G.traps[sig][0])
2961 G.traps[sig] = NULL;
2962 /* There is no signal for 0 (EXIT) */
2965 /* There was a trap handler, we just removed it.
2966 * But if sig still has non-DFL handling,
2967 * we should not unblock the sig. */
2970 sigdelset(&G.blocked_set, sig);
2972 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2977 static void re_execute_shell(char ***to_free, const char *s,
2978 char *g_argv0, char **g_argv,
2979 char **builtin_argv) NORETURN;
2980 static void re_execute_shell(char ***to_free, const char *s,
2981 char *g_argv0, char **g_argv,
2982 char **builtin_argv)
2984 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
2985 /* delims + 2 * (number of bytes in printed hex numbers) */
2986 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
2987 char *heredoc_argv[4];
2988 struct variable *cur;
2989 # if ENABLE_HUSH_FUNCTIONS
2990 struct function *funcp;
2994 unsigned long long empty_trap_mask;
2996 if (!g_argv0) { /* heredoc */
2997 argv = heredoc_argv;
2998 argv[0] = (char *) G.argv0_for_re_execing;
2999 argv[1] = (char *) "-<";
3000 argv[2] = (char *) s;
3002 pp = &argv[3]; /* used as pointer to empty environment */
3008 if (pp) while (*pp++)
3011 empty_trap_mask = 0;
3014 for (sig = 1; sig < NSIG; sig++) {
3015 if (G.traps[sig] && !G.traps[sig][0])
3016 empty_trap_mask |= 1LL << sig;
3020 sprintf(param_buf, NOMMU_HACK_FMT
3021 , (unsigned) G.root_pid
3022 , (unsigned) G.root_ppid
3023 , (unsigned) G.last_bg_pid
3024 , (unsigned) G.last_exitcode
3027 IF_HUSH_LOOPS(, G.depth_of_loop)
3029 #undef NOMMU_HACK_FMT
3030 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3031 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3034 for (cur = G.top_var; cur; cur = cur->next) {
3035 if (!cur->flg_export || cur->flg_read_only)
3038 # if ENABLE_HUSH_FUNCTIONS
3039 for (funcp = G.top_func; funcp; funcp = funcp->next)
3045 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3046 *pp++ = (char *) G.argv0_for_re_execing;
3048 for (cur = G.top_var; cur; cur = cur->next) {
3049 if (cur->varstr == hush_version_str)
3051 if (cur->flg_read_only) {
3052 *pp++ = (char *) "-R";
3053 *pp++ = cur->varstr;
3054 } else if (!cur->flg_export) {
3055 *pp++ = (char *) "-V";
3056 *pp++ = cur->varstr;
3059 # if ENABLE_HUSH_FUNCTIONS
3060 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3061 *pp++ = (char *) "-F";
3062 *pp++ = funcp->name;
3063 *pp++ = funcp->body_as_string;
3066 /* We can pass activated traps here. Say, -Tnn:trap_string
3068 * However, POSIX says that subshells reset signals with traps
3070 * I tested bash-3.2 and it not only does that with true subshells
3071 * of the form ( list ), but with any forked children shells.
3072 * I set trap "echo W" WINCH; and then tried:
3074 * { echo 1; sleep 20; echo 2; } &
3075 * while true; do echo 1; sleep 20; echo 2; break; done &
3076 * true | { echo 1; sleep 20; echo 2; } | cat
3078 * In all these cases sending SIGWINCH to the child shell
3079 * did not run the trap. If I add trap "echo V" WINCH;
3080 * _inside_ group (just before echo 1), it works.
3082 * I conclude it means we don't need to pass active traps here.
3083 * Even if we would use signal handlers instead of signal masking
3084 * in order to implement trap handling,
3085 * exec syscall below resets signals to SIG_DFL for us.
3087 *pp++ = (char *) "-c";
3090 while (*++builtin_argv)
3091 *pp++ = *builtin_argv;
3092 *pp++ = (char *) "";
3097 /* *pp = NULL; - is already there */
3101 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3102 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3103 execve(bb_busybox_exec_path, argv, pp);
3104 /* Fallback. Useful for init=/bin/hush usage etc */
3105 if (argv[0][0] == '/')
3106 execve(argv[0], argv, pp);
3107 xfunc_error_retval = 127;
3108 bb_error_msg_and_die("can't re-execute the shell");
3110 #endif /* !BB_MMU */
3113 static void setup_heredoc(struct redir_struct *redir)
3115 struct fd_pair pair;
3118 /* the _body_ of heredoc (misleading field name) */
3119 const char *heredoc = redir->rd_filename;
3126 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3127 expanded = expand_pseudo_dquoted(heredoc);
3131 len = strlen(heredoc);
3133 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3135 xmove_fd(pair.rd, redir->rd_fd);
3137 /* Try writing without forking. Newer kernels have
3138 * dynamically growing pipes. Must use non-blocking write! */
3141 written = write(pair.wr, heredoc, len);
3152 ndelay_off(pair.wr);
3154 /* Okay, pipe buffer was not big enough */
3155 /* Note: we must not create a stray child (bastard? :)
3156 * for the unsuspecting parent process. Child creates a grandchild
3157 * and exits before parent execs the process which consumes heredoc
3158 * (that exec happens after we return from this function) */
3164 bb_perror_msg_and_die("vfork");
3167 disable_restore_tty_pgrp_on_exit();
3168 pid = BB_MMU ? fork() : vfork();
3170 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3174 close(redir->rd_fd); /* read side of the pipe */
3176 full_write(pair.wr, heredoc, len); /* may loop or block */
3179 /* Delegate blocking writes to another process */
3180 xmove_fd(pair.wr, STDOUT_FILENO);
3181 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3185 #if ENABLE_HUSH_FAST
3187 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3189 enable_restore_tty_pgrp_on_exit();
3195 wait(NULL); /* wait till child has died */
3198 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3199 * and stderr if they are redirected. */
3200 static int setup_redirects(struct command *prog, int squirrel[])
3203 struct redir_struct *redir;
3205 for (redir = prog->redirects; redir; redir = redir->next) {
3206 if (redir->rd_type == REDIRECT_HEREDOC2) {
3207 /* rd_fd<<HERE case */
3208 if (squirrel && redir->rd_fd < 3
3209 && squirrel[redir->rd_fd] < 0
3211 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3213 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3215 debug_printf_parse("set heredoc '%s'\n",
3216 redir->rd_filename);
3217 setup_heredoc(redir);
3221 if (redir->rd_dup == REDIRFD_TO_FILE) {
3222 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3224 if (redir->rd_filename == NULL) {
3225 /* Something went wrong in the parse.
3226 * Pretend it didn't happen */
3227 bb_error_msg("bug in redirect parse");
3230 mode = redir_table[redir->rd_type].mode;
3231 p = expand_string_to_string(redir->rd_filename);
3232 openfd = open_or_warn(p, mode);
3235 /* this could get lost if stderr has been redirected, but
3236 * bash and ash both lose it as well (though zsh doesn't!) */
3237 //what the above comment tries to say?
3241 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3242 openfd = redir->rd_dup;
3245 if (openfd != redir->rd_fd) {
3246 if (squirrel && redir->rd_fd < 3
3247 && squirrel[redir->rd_fd] < 0
3249 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3251 if (openfd == REDIRFD_CLOSE) {
3252 /* "n>-" means "close me" */
3253 close(redir->rd_fd);
3255 xdup2(openfd, redir->rd_fd);
3256 if (redir->rd_dup == REDIRFD_TO_FILE)
3264 static void restore_redirects(int squirrel[])
3267 for (i = 0; i < 3; i++) {
3270 /* We simply die on error */
3277 static void free_pipe_list(struct pipe *head);
3279 /* Return code is the exit status of the pipe */
3280 static void free_pipe(struct pipe *pi)
3283 struct command *command;
3284 struct redir_struct *r, *rnext;
3287 if (pi->stopped_cmds > 0) /* why? */
3289 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3290 for (i = 0; i < pi->num_cmds; i++) {
3291 command = &pi->cmds[i];
3292 debug_printf_clean(" command %d:\n", i);
3293 if (command->argv) {
3294 for (a = 0, p = command->argv; *p; a++, p++) {
3295 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3297 free_strings(command->argv);
3298 command->argv = NULL;
3300 /* not "else if": on syntax error, we may have both! */
3301 if (command->group) {
3302 debug_printf_clean(" begin group (cmd_type:%d)\n",
3304 free_pipe_list(command->group);
3305 debug_printf_clean(" end group\n");
3306 command->group = NULL;
3308 /* else is crucial here.
3309 * If group != NULL, child_func is meaningless */
3310 #if ENABLE_HUSH_FUNCTIONS
3311 else if (command->child_func) {
3312 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3313 command->child_func->parent_cmd = NULL;
3317 free(command->group_as_string);
3318 command->group_as_string = NULL;
3320 for (r = command->redirects; r; r = rnext) {
3321 debug_printf_clean(" redirect %d%s",
3322 r->rd_fd, redir_table[r->rd_type].descrip);
3323 /* guard against the case >$FOO, where foo is unset or blank */
3324 if (r->rd_filename) {
3325 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3326 free(r->rd_filename);
3327 r->rd_filename = NULL;
3329 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3333 command->redirects = NULL;
3335 free(pi->cmds); /* children are an array, they get freed all at once */
3343 static void free_pipe_list(struct pipe *head)
3345 struct pipe *pi, *next;
3347 for (pi = head; pi; pi = next) {
3349 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3352 debug_printf_clean("pipe followup code %d\n", pi->followup);
3354 /*pi->next = NULL;*/
3360 static int run_list(struct pipe *pi);
3362 #define parse_stream(pstring, input, end_trigger) \
3363 parse_stream(input, end_trigger)
3365 static struct pipe *parse_stream(char **pstring,
3366 struct in_str *input,
3368 static void parse_and_run_string(const char *s);
3371 static char *find_in_path(const char *arg)
3374 const char *PATH = get_local_var_value("PATH");
3380 const char *end = strchrnul(PATH, ':');
3381 int sz = end - PATH; /* must be int! */
3385 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3387 /* We have xxx::yyyy in $PATH,
3388 * it means "use current dir" */
3391 if (access(ret, F_OK) == 0)
3404 static const struct built_in_command* find_builtin_helper(const char *name,
3405 const struct built_in_command *x,
3406 const struct built_in_command *end)
3409 if (strcmp(name, x->b_cmd) != 0) {
3413 debug_printf_exec("found builtin '%s'\n", name);
3418 static const struct built_in_command* find_builtin1(const char *name)
3420 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3422 static const struct built_in_command* find_builtin(const char *name)
3424 const struct built_in_command *x = find_builtin1(name);
3427 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3430 #if ENABLE_HUSH_FUNCTIONS
3431 static struct function **find_function_slot(const char *name)
3433 struct function **funcpp = &G.top_func;
3435 if (strcmp(name, (*funcpp)->name) == 0) {
3438 funcpp = &(*funcpp)->next;
3443 static const struct function *find_function(const char *name)
3445 const struct function *funcp = *find_function_slot(name);
3447 debug_printf_exec("found function '%s'\n", name);
3451 /* Note: takes ownership on name ptr */
3452 static struct function *new_function(char *name)
3454 struct function **funcpp = find_function_slot(name);
3455 struct function *funcp = *funcpp;
3457 if (funcp != NULL) {
3458 struct command *cmd = funcp->parent_cmd;
3459 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3461 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3463 /* Note: if !funcp->body, do not free body_as_string!
3464 * This is a special case of "-F name body" function:
3465 * body_as_string was not malloced! */
3467 free_pipe_list(funcp->body);
3469 free(funcp->body_as_string);
3473 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3474 cmd->argv[0] = funcp->name;
3475 cmd->group = funcp->body;
3477 cmd->group_as_string = funcp->body_as_string;
3481 debug_printf_exec("remembering new function '%s'\n", name);
3482 funcp = *funcpp = xzalloc(sizeof(*funcp));
3483 /*funcp->next = NULL;*/
3490 static void unset_func(const char *name)
3492 struct function **funcpp = find_function_slot(name);
3493 struct function *funcp = *funcpp;
3495 if (funcp != NULL) {
3496 debug_printf_exec("freeing function '%s'\n", funcp->name);
3497 *funcpp = funcp->next;
3498 /* funcp is unlinked now, deleting it.
3499 * Note: if !funcp->body, the function was created by
3500 * "-F name body", do not free ->body_as_string
3501 * and ->name as they were not malloced. */
3503 free_pipe_list(funcp->body);
3506 free(funcp->body_as_string);
3514 #define exec_function(to_free, funcp, argv) \
3515 exec_function(funcp, argv)
3517 static void exec_function(char ***to_free,
3518 const struct function *funcp,
3519 char **argv) NORETURN;
3520 static void exec_function(char ***to_free,
3521 const struct function *funcp,
3527 argv[0] = G.global_argv[0];
3528 G.global_argv = argv;
3532 /* On MMU, funcp->body is always non-NULL */
3533 n = run_list(funcp->body);
3537 re_execute_shell(to_free,
3538 funcp->body_as_string,
3545 static int run_function(const struct function *funcp, char **argv)
3551 save_and_replace_G_args(&sv, argv);
3553 /* "we are in function, ok to use return" */
3554 sv_flg = G.flag_return_in_progress;
3555 G.flag_return_in_progress = -1;
3556 # if ENABLE_HUSH_LOCAL
3557 G.func_nest_level++;
3560 /* On MMU, funcp->body is always non-NULL */
3563 /* Function defined by -F */
3564 parse_and_run_string(funcp->body_as_string);
3565 rc = G.last_exitcode;
3569 rc = run_list(funcp->body);
3572 # if ENABLE_HUSH_LOCAL
3574 struct variable *var;
3575 struct variable **var_pp;
3577 var_pp = &G.top_var;
3578 while ((var = *var_pp) != NULL) {
3579 if (var->func_nest_level < G.func_nest_level) {
3580 var_pp = &var->next;
3584 if (var->flg_export)
3585 bb_unsetenv(var->varstr);
3586 /* Remove from global list */
3587 *var_pp = var->next;
3593 G.func_nest_level--;
3596 G.flag_return_in_progress = sv_flg;
3598 restore_G_args(&sv, argv);
3602 #endif /* ENABLE_HUSH_FUNCTIONS */
3606 #define exec_builtin(to_free, x, argv) \
3607 exec_builtin(x, argv)
3609 #define exec_builtin(to_free, x, argv) \
3610 exec_builtin(to_free, argv)
3612 static void exec_builtin(char ***to_free,
3613 const struct built_in_command *x,
3614 char **argv) NORETURN;
3615 static void exec_builtin(char ***to_free,
3616 const struct built_in_command *x,
3620 int rcode = x->b_function(argv);
3624 /* On NOMMU, we must never block!
3625 * Example: { sleep 99 | read line; } & echo Ok
3627 re_execute_shell(to_free,
3636 static void execvp_or_die(char **argv) NORETURN;
3637 static void execvp_or_die(char **argv)
3639 debug_printf_exec("execing '%s'\n", argv[0]);
3640 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3641 execvp(argv[0], argv);
3642 bb_perror_msg("can't execute '%s'", argv[0]);
3643 _exit(127); /* bash compat */
3647 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3648 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3649 #define pseudo_exec(nommu_save, command, argv_expanded) \
3650 pseudo_exec(command, argv_expanded)
3653 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3655 * Don't exit() here. If you don't exec, use _exit instead.
3656 * The at_exit handlers apparently confuse the calling process,
3657 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3658 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3659 char **argv, int assignment_cnt,
3660 char **argv_expanded) NORETURN;
3661 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3662 char **argv, int assignment_cnt,
3663 char **argv_expanded)
3667 /* Case when we are here: ... | var=val | ... */
3668 if (!argv[assignment_cnt])
3669 _exit(EXIT_SUCCESS);
3671 new_env = expand_assignments(argv, assignment_cnt);
3673 set_vars_and_save_old(new_env);
3674 free(new_env); /* optional */
3675 /* we can also destroy set_vars_and_save_old's return value,
3678 nommu_save->new_env = new_env;
3679 nommu_save->old_vars = set_vars_and_save_old(new_env);
3681 if (argv_expanded) {
3682 argv = argv_expanded;
3684 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3686 nommu_save->argv = argv;
3690 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3691 if (strchr(argv[0], '/') != NULL)
3695 /* Check if the command matches any of the builtins.
3696 * Depending on context, this might be redundant. But it's
3697 * easier to waste a few CPU cycles than it is to figure out
3698 * if this is one of those cases.
3701 /* On NOMMU, it is more expensive to re-execute shell
3702 * just in order to run echo or test builtin.
3703 * It's better to skip it here and run corresponding
3704 * non-builtin later. */
3705 const struct built_in_command *x;
3706 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3708 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3711 #if ENABLE_HUSH_FUNCTIONS
3712 /* Check if the command matches any functions */
3714 const struct function *funcp = find_function(argv[0]);
3716 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3721 #if ENABLE_FEATURE_SH_STANDALONE
3722 /* Check if the command matches any busybox applets */
3724 int a = find_applet_by_name(argv[0]);
3726 # if BB_MMU /* see above why on NOMMU it is not allowed */
3727 if (APPLET_IS_NOEXEC(a)) {
3728 debug_printf_exec("running applet '%s'\n", argv[0]);
3729 run_applet_no_and_exit(a, argv);
3732 /* Re-exec ourselves */
3733 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3734 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3735 execv(bb_busybox_exec_path, argv);
3736 /* If they called chroot or otherwise made the binary no longer
3737 * executable, fall through */
3742 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3745 execvp_or_die(argv);
3748 /* Called after [v]fork() in run_pipe
3750 static void pseudo_exec(nommu_save_t *nommu_save,
3751 struct command *command,
3752 char **argv_expanded) NORETURN;
3753 static void pseudo_exec(nommu_save_t *nommu_save,
3754 struct command *command,
3755 char **argv_expanded)
3757 if (command->argv) {
3758 pseudo_exec_argv(nommu_save, command->argv,
3759 command->assignment_cnt, argv_expanded);
3762 if (command->group) {
3763 /* Cases when we are here:
3766 * ... | ( list ) | ...
3767 * ... | { list } | ...
3771 debug_printf_exec("pseudo_exec: run_list\n");
3772 reset_traps_to_defaults();
3773 rcode = run_list(command->group);
3774 /* OK to leak memory by not calling free_pipe_list,
3775 * since this process is about to exit */
3778 re_execute_shell(&nommu_save->argv_from_re_execing,
3779 command->group_as_string,
3786 /* Case when we are here: ... | >file */
3787 debug_printf_exec("pseudo_exec'ed null command\n");
3788 _exit(EXIT_SUCCESS);
3792 static const char *get_cmdtext(struct pipe *pi)
3798 /* This is subtle. ->cmdtext is created only on first backgrounding.
3799 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3800 * On subsequent bg argv is trashed, but we won't use it */
3803 argv = pi->cmds[0].argv;
3804 if (!argv || !argv[0]) {
3805 pi->cmdtext = xzalloc(1);
3811 len += strlen(*argv) + 1;
3815 argv = pi->cmds[0].argv;
3817 len = strlen(*argv);
3818 memcpy(p, *argv, len);
3826 static void insert_bg_job(struct pipe *pi)
3828 struct pipe *job, **jobp;
3831 /* Linear search for the ID of the job to use */
3833 for (job = G.job_list; job; job = job->next)
3834 if (job->jobid >= pi->jobid)
3835 pi->jobid = job->jobid + 1;
3837 /* Add job to the list of running jobs */
3839 while ((job = *jobp) != NULL)
3841 job = *jobp = xmalloc(sizeof(*job));
3843 *job = *pi; /* physical copy */
3845 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3846 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3847 for (i = 0; i < pi->num_cmds; i++) {
3848 job->cmds[i].pid = pi->cmds[i].pid;
3849 /* all other fields are not used and stay zero */
3851 job->cmdtext = xstrdup(get_cmdtext(pi));
3853 if (G_interactive_fd)
3854 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3855 /* Last command's pid goes to $! */
3856 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3857 G.last_jobid = job->jobid;
3860 static void remove_bg_job(struct pipe *pi)
3862 struct pipe *prev_pipe;
3864 if (pi == G.job_list) {
3865 G.job_list = pi->next;
3867 prev_pipe = G.job_list;
3868 while (prev_pipe->next != pi)
3869 prev_pipe = prev_pipe->next;
3870 prev_pipe->next = pi->next;
3873 G.last_jobid = G.job_list->jobid;
3878 /* Remove a backgrounded job */
3879 static void delete_finished_bg_job(struct pipe *pi)
3882 pi->stopped_cmds = 0;
3888 /* Check to see if any processes have exited -- if they
3889 * have, figure out why and see if a job has completed */
3890 static int checkjobs(struct pipe* fg_pipe)
3900 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3902 attributes = WUNTRACED;
3903 if (fg_pipe == NULL)
3904 attributes |= WNOHANG;
3907 #if ENABLE_HUSH_FAST
3908 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3909 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3910 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3911 /* There was neither fork nor SIGCHLD since last waitpid */
3912 /* Avoid doing waitpid syscall if possible */
3913 if (!G.we_have_children) {
3917 if (fg_pipe == NULL) { /* is WNOHANG set? */
3918 /* We have children, but they did not exit
3919 * or stop yet (we saw no SIGCHLD) */
3922 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3926 /* Do we do this right?
3927 * bash-3.00# sleep 20 | false
3929 * [3]+ Stopped sleep 20 | false
3930 * bash-3.00# echo $?
3931 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3932 * [hush 1.14.0: yes we do it right]
3939 #if ENABLE_HUSH_FAST
3940 i = G.count_SIGCHLD;
3942 childpid = waitpid(-1, &status, attributes);
3943 if (childpid <= 0) {
3944 if (childpid && errno != ECHILD)
3945 bb_perror_msg("waitpid");
3946 #if ENABLE_HUSH_FAST
3947 else { /* Until next SIGCHLD, waitpid's are useless */
3948 G.we_have_children = (childpid == 0);
3949 G.handled_SIGCHLD = i;
3950 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3955 dead = WIFEXITED(status) || WIFSIGNALED(status);
3958 if (WIFSTOPPED(status))
3959 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3960 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3961 if (WIFSIGNALED(status))
3962 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3963 childpid, WTERMSIG(status), WEXITSTATUS(status));
3964 if (WIFEXITED(status))
3965 debug_printf_jobs("pid %d exited, exitcode %d\n",
3966 childpid, WEXITSTATUS(status));
3968 /* Were we asked to wait for fg pipe? */
3970 for (i = 0; i < fg_pipe->num_cmds; i++) {
3971 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3972 if (fg_pipe->cmds[i].pid != childpid)
3975 fg_pipe->cmds[i].pid = 0;
3976 fg_pipe->alive_cmds--;
3977 if (i == fg_pipe->num_cmds - 1) {
3978 /* last process gives overall exitstatus */
3979 rcode = WEXITSTATUS(status);
3980 /* bash prints killer signal's name for *last*
3981 * process in pipe (prints just newline for SIGINT).
3982 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
3984 if (WIFSIGNALED(status)) {
3985 int sig = WTERMSIG(status);
3986 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3987 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
3988 * Maybe we need to use sig | 128? */
3991 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3994 fg_pipe->cmds[i].is_stopped = 1;
3995 fg_pipe->stopped_cmds++;
3997 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3998 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3999 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
4000 /* All processes in fg pipe have exited or stopped */
4001 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4002 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4003 * and "killall -STOP cat" */
4004 if (G_interactive_fd) {
4006 if (fg_pipe->alive_cmds)
4007 insert_bg_job(fg_pipe);
4011 if (!fg_pipe->alive_cmds)
4014 /* There are still running processes in the fg pipe */
4015 goto wait_more; /* do waitpid again */
4017 /* it wasnt fg_pipe, look for process in bg pipes */
4021 /* We asked to wait for bg or orphaned children */
4022 /* No need to remember exitcode in this case */
4023 for (pi = G.job_list; pi; pi = pi->next) {
4024 for (i = 0; i < pi->num_cmds; i++) {
4025 if (pi->cmds[i].pid == childpid)
4026 goto found_pi_and_prognum;
4029 /* Happens when shell is used as init process (init=/bin/sh) */
4030 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4031 continue; /* do waitpid again */
4033 found_pi_and_prognum:
4036 pi->cmds[i].pid = 0;
4038 if (!pi->alive_cmds) {
4039 if (G_interactive_fd)
4040 printf(JOB_STATUS_FORMAT, pi->jobid,
4041 "Done", pi->cmdtext);
4042 delete_finished_bg_job(pi);
4046 pi->cmds[i].is_stopped = 1;
4050 } /* while (waitpid succeeds)... */
4056 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4059 int rcode = checkjobs(fg_pipe);
4060 if (G_saved_tty_pgrp) {
4061 /* Job finished, move the shell to the foreground */
4062 p = getpgrp(); /* our process group id */
4063 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4064 tcsetpgrp(G_interactive_fd, p);
4070 /* Start all the jobs, but don't wait for anything to finish.
4073 * Return code is normally -1, when the caller has to wait for children
4074 * to finish to determine the exit status of the pipe. If the pipe
4075 * is a simple builtin command, however, the action is done by the
4076 * time run_pipe returns, and the exit code is provided as the
4079 * Returns -1 only if started some children. IOW: we have to
4080 * mask out retvals of builtins etc with 0xff!
4082 * The only case when we do not need to [v]fork is when the pipe
4083 * is single, non-backgrounded, non-subshell command. Examples:
4084 * cmd ; ... { list } ; ...
4085 * cmd && ... { list } && ...
4086 * cmd || ... { list } || ...
4087 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4088 * or (if SH_STANDALONE) an applet, and we can run the { list }
4089 * with run_list. If it isn't one of these, we fork and exec cmd.
4091 * Cases when we must fork:
4092 * non-single: cmd | cmd
4093 * backgrounded: cmd & { list } &
4094 * subshell: ( list ) [&]
4096 static NOINLINE int run_pipe(struct pipe *pi)
4098 static const char *const null_ptr = NULL;
4101 struct command *command;
4102 char **argv_expanded;
4105 /* it is not always needed, but we aim to smaller code */
4106 int squirrel[] = { -1, -1, -1 };
4109 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4112 IF_HUSH_JOB(pi->pgrp = -1;)
4113 pi->stopped_cmds = 0;
4114 command = &(pi->cmds[0]);
4115 argv_expanded = NULL;
4117 if (pi->num_cmds != 1
4118 || pi->followup == PIPE_BG
4119 || command->cmd_type == CMD_SUBSHELL
4126 debug_printf_exec(": group:%p argv:'%s'\n",
4127 command->group, command->argv ? command->argv[0] : "NONE");
4129 if (command->group) {
4130 #if ENABLE_HUSH_FUNCTIONS
4131 if (command->cmd_type == CMD_FUNCDEF) {
4132 /* "executing" func () { list } */
4133 struct function *funcp;
4135 funcp = new_function(command->argv[0]);
4136 /* funcp->name is already set to argv[0] */
4137 funcp->body = command->group;
4139 funcp->body_as_string = command->group_as_string;
4140 command->group_as_string = NULL;
4142 command->group = NULL;
4143 command->argv[0] = NULL;
4144 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4145 funcp->parent_cmd = command;
4146 command->child_func = funcp;
4148 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4150 return EXIT_SUCCESS;
4154 debug_printf("non-subshell group\n");
4155 rcode = 1; /* exitcode if redir failed */
4156 if (setup_redirects(command, squirrel) == 0) {
4157 debug_printf_exec(": run_list\n");
4158 rcode = run_list(command->group) & 0xff;
4160 restore_redirects(squirrel);
4161 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4163 debug_printf_exec("run_pipe: return %d\n", rcode);
4167 argv = command->argv ? command->argv : (char **) &null_ptr;
4169 const struct built_in_command *x;
4170 #if ENABLE_HUSH_FUNCTIONS
4171 const struct function *funcp;
4175 char **new_env = NULL;
4176 struct variable *old_vars = NULL;
4178 if (argv[command->assignment_cnt] == NULL) {
4179 /* Assignments, but no command */
4180 /* Ensure redirects take effect (that is, create files).
4181 * Try "a=t >file": */
4182 rcode = setup_redirects(command, squirrel);
4183 restore_redirects(squirrel);
4184 /* Set shell variables */
4186 p = expand_string_to_string(*argv);
4187 debug_printf_exec("set shell var:'%s'->'%s'\n",
4189 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4192 /* Redirect error sets $? to 1. Othervise,
4193 * if evaluating assignment value set $?, retain it.
4194 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4196 rcode = G.last_exitcode;
4197 /* Do we need to flag set_local_var() errors?
4198 * "assignment to readonly var" and "putenv error"
4200 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4202 debug_printf_exec("run_pipe: return %d\n", rcode);
4206 /* Expand the rest into (possibly) many strings each */
4208 #if ENABLE_HUSH_BASH_COMPAT
4209 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4210 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4213 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4214 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4215 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4220 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4223 /* if someone gives us an empty string: `cmd with empty output` */
4224 if (!argv_expanded[0]) {
4225 free(argv_expanded);
4227 return G.last_exitcode;
4230 x = find_builtin(argv_expanded[0]);
4231 #if ENABLE_HUSH_FUNCTIONS
4234 funcp = find_function(argv_expanded[0]);
4238 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4239 debug_printf("exec with redirects only\n");
4240 rcode = setup_redirects(command, NULL);
4241 goto clean_up_and_ret1;
4244 /* setup_redirects acts on file descriptors, not FILEs.
4245 * This is perfect for work that comes after exec().
4246 * Is it really safe for inline use? Experimentally,
4247 * things seem to work. */
4248 rcode = setup_redirects(command, squirrel);
4250 new_env = expand_assignments(argv, command->assignment_cnt);
4251 old_vars = set_vars_and_save_old(new_env);
4253 debug_printf_exec(": builtin '%s' '%s'...\n",
4254 x->b_cmd, argv_expanded[1]);
4255 rcode = x->b_function(argv_expanded) & 0xff;
4258 #if ENABLE_HUSH_FUNCTIONS
4260 # if ENABLE_HUSH_LOCAL
4261 struct variable **sv;
4262 sv = G.shadowed_vars_pp;
4263 G.shadowed_vars_pp = &old_vars;
4265 debug_printf_exec(": function '%s' '%s'...\n",
4266 funcp->name, argv_expanded[1]);
4267 rcode = run_function(funcp, argv_expanded) & 0xff;
4268 # if ENABLE_HUSH_LOCAL
4269 G.shadowed_vars_pp = sv;
4274 #if ENABLE_FEATURE_SH_STANDALONE
4277 restore_redirects(squirrel);
4278 unset_vars(new_env);
4281 free(argv_expanded);
4282 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4284 debug_printf_exec("run_pipe return %d\n", rcode);
4288 #if ENABLE_FEATURE_SH_STANDALONE
4289 i = find_applet_by_name(argv_expanded[0]);
4290 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4291 rcode = setup_redirects(command, squirrel);
4293 new_env = expand_assignments(argv, command->assignment_cnt);
4294 old_vars = set_vars_and_save_old(new_env);
4295 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4296 argv_expanded[0], argv_expanded[1]);
4297 rcode = run_nofork_applet(i, argv_expanded);
4299 goto clean_up_and_ret;
4302 /* It is neither builtin nor applet. We must fork. */
4306 /* NB: argv_expanded may already be created, and that
4307 * might include `cmd` runs! Do not rerun it! We *must*
4308 * use argv_expanded if it's non-NULL */
4310 /* Going to fork a child per each pipe member */
4314 for (i = 0; i < pi->num_cmds; i++) {
4315 struct fd_pair pipefds;
4317 volatile nommu_save_t nommu_save;
4318 nommu_save.new_env = NULL;
4319 nommu_save.old_vars = NULL;
4320 nommu_save.argv = NULL;
4321 nommu_save.argv_from_re_execing = NULL;
4323 command = &(pi->cmds[i]);
4324 if (command->argv) {
4325 debug_printf_exec(": pipe member '%s' '%s'...\n",
4326 command->argv[0], command->argv[1]);
4328 debug_printf_exec(": pipe member with no argv\n");
4331 /* pipes are inserted between pairs of commands */
4334 if ((i + 1) < pi->num_cmds)
4335 xpiped_pair(pipefds);
4337 command->pid = BB_MMU ? fork() : vfork();
4338 if (!command->pid) { /* child */
4340 disable_restore_tty_pgrp_on_exit();
4341 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4343 /* Every child adds itself to new process group
4344 * with pgid == pid_of_first_child_in_pipe */
4345 if (G.run_list_level == 1 && G_interactive_fd) {
4348 if (pgrp < 0) /* true for 1st process only */
4350 if (setpgid(0, pgrp) == 0
4351 && pi->followup != PIPE_BG
4352 && G_saved_tty_pgrp /* we have ctty */
4354 /* We do it in *every* child, not just first,
4356 tcsetpgrp(G_interactive_fd, pgrp);
4360 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4361 /* 1st cmd in backgrounded pipe
4362 * should have its stdin /dev/null'ed */
4364 if (open(bb_dev_null, O_RDONLY))
4365 xopen("/", O_RDONLY);
4367 xmove_fd(nextin, 0);
4369 xmove_fd(pipefds.wr, 1);
4372 /* Like bash, explicit redirects override pipes,
4373 * and the pipe fd is available for dup'ing. */
4374 if (setup_redirects(command, NULL))
4377 /* Restore default handlers just prior to exec */
4378 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4380 /* Stores to nommu_save list of env vars putenv'ed
4381 * (NOMMU, on MMU we don't need that) */
4382 /* cast away volatility... */
4383 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4384 /* pseudo_exec() does not return */
4387 /* parent or error */
4388 #if ENABLE_HUSH_FAST
4390 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4392 enable_restore_tty_pgrp_on_exit();
4394 /* Clean up after vforked child */
4395 free(nommu_save.argv);
4396 free(nommu_save.argv_from_re_execing);
4397 unset_vars(nommu_save.new_env);
4398 add_vars(nommu_save.old_vars);
4400 free(argv_expanded);
4401 argv_expanded = NULL;
4402 if (command->pid < 0) { /* [v]fork failed */
4403 /* Clearly indicate, was it fork or vfork */
4404 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4408 /* Second and next children need to know pid of first one */
4410 pi->pgrp = command->pid;
4416 if ((i + 1) < pi->num_cmds)
4418 /* Pass read (output) pipe end to next iteration */
4419 nextin = pipefds.rd;
4422 if (!pi->alive_cmds) {
4424 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4429 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4433 #ifndef debug_print_tree
4434 static void debug_print_tree(struct pipe *pi, int lvl)
4436 static const char *const PIPE[] = {
4442 static const char *RES[] = {
4443 [RES_NONE ] = "NONE" ,
4446 [RES_THEN ] = "THEN" ,
4447 [RES_ELIF ] = "ELIF" ,
4448 [RES_ELSE ] = "ELSE" ,
4451 # if ENABLE_HUSH_LOOPS
4452 [RES_FOR ] = "FOR" ,
4453 [RES_WHILE] = "WHILE",
4454 [RES_UNTIL] = "UNTIL",
4456 [RES_DONE ] = "DONE" ,
4458 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4461 # if ENABLE_HUSH_CASE
4462 [RES_CASE ] = "CASE" ,
4463 [RES_CASE_IN ] = "CASE_IN" ,
4464 [RES_MATCH] = "MATCH",
4465 [RES_CASE_BODY] = "CASE_BODY",
4466 [RES_ESAC ] = "ESAC" ,
4468 [RES_XXXX ] = "XXXX" ,
4469 [RES_SNTX ] = "SNTX" ,
4471 static const char *const CMDTYPE[] = {
4475 # if ENABLE_HUSH_FUNCTIONS
4484 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4485 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4487 while (prn < pi->num_cmds) {
4488 struct command *command = &pi->cmds[prn];
4489 char **argv = command->argv;
4491 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4493 command->assignment_cnt);
4494 if (command->group) {
4495 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4496 CMDTYPE[command->cmd_type],
4499 , " group_as_string:", command->group_as_string
4504 debug_print_tree(command->group, lvl+1);
4508 if (argv) while (*argv) {
4509 fprintf(stderr, " '%s'", *argv);
4512 fprintf(stderr, "\n");
4519 #endif /* debug_print_tree */
4521 /* NB: called by pseudo_exec, and therefore must not modify any
4522 * global data until exec/_exit (we can be a child after vfork!) */
4523 static int run_list(struct pipe *pi)
4525 #if ENABLE_HUSH_CASE
4526 char *case_word = NULL;
4528 #if ENABLE_HUSH_LOOPS
4529 struct pipe *loop_top = NULL;
4530 char **for_lcur = NULL;
4531 char **for_list = NULL;
4533 smallint last_followup;
4535 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4536 smalluint cond_code = 0;
4538 enum { cond_code = 0 };
4541 smallint rword; /* enum reserved_style */
4542 smallint last_rword; /* ditto */
4545 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4548 #if ENABLE_HUSH_LOOPS
4549 /* Check syntax for "for" */
4550 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4551 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4553 /* current word is FOR or IN (BOLD in comments below) */
4554 if (cpipe->next == NULL) {
4555 syntax_error("malformed for");
4557 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4560 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4561 if (cpipe->next->res_word == RES_DO)
4563 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4564 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4565 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4567 syntax_error("malformed for");
4569 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4575 /* Past this point, all code paths should jump to ret: label
4576 * in order to return, no direct "return" statements please.
4577 * This helps to ensure that no memory is leaked. */
4585 last_rword = RES_XXXX;
4587 last_followup = PIPE_SEQ;
4588 rcode = G.last_exitcode;
4590 /* Go through list of pipes, (maybe) executing them. */
4591 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4595 IF_HAS_KEYWORDS(rword = pi->res_word;)
4596 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4597 rword, cond_code, last_rword);
4598 #if ENABLE_HUSH_LOOPS
4599 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4600 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4602 /* start of a loop: remember where loop starts */
4607 /* Still in the same "if...", "then..." or "do..." branch? */
4608 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4609 if ((rcode == 0 && last_followup == PIPE_OR)
4610 || (rcode != 0 && last_followup == PIPE_AND)
4612 /* It is "<true> || CMD" or "<false> && CMD"
4613 * and we should not execute CMD */
4614 debug_printf_exec("skipped cmd because of || or &&\n");
4615 last_followup = pi->followup;
4619 last_followup = pi->followup;
4620 IF_HAS_KEYWORDS(last_rword = rword;)
4623 if (rword == RES_THEN) {
4624 /* if false; then ... fi has exitcode 0! */
4625 G.last_exitcode = rcode = EXIT_SUCCESS;
4626 /* "if <false> THEN cmd": skip cmd */
4630 if (rword == RES_ELSE || rword == RES_ELIF) {
4631 /* "if <true> then ... ELSE/ELIF cmd":
4632 * skip cmd and all following ones */
4637 #if ENABLE_HUSH_LOOPS
4638 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4640 /* first loop through for */
4642 static const char encoded_dollar_at[] ALIGN1 = {
4643 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4644 }; /* encoded representation of "$@" */
4645 static const char *const encoded_dollar_at_argv[] = {
4646 encoded_dollar_at, NULL
4647 }; /* argv list with one element: "$@" */
4650 vals = (char**)encoded_dollar_at_argv;
4651 if (pi->next->res_word == RES_IN) {
4652 /* if no variable values after "in" we skip "for" */
4653 if (!pi->next->cmds[0].argv) {
4654 G.last_exitcode = rcode = EXIT_SUCCESS;
4655 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4658 vals = pi->next->cmds[0].argv;
4659 } /* else: "for var; do..." -> assume "$@" list */
4660 /* create list of variable values */
4661 debug_print_strings("for_list made from", vals);
4662 for_list = expand_strvec_to_strvec(vals);
4663 for_lcur = for_list;
4664 debug_print_strings("for_list", for_list);
4667 /* "for" loop is over, clean up */
4673 /* Insert next value from for_lcur */
4674 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4675 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4678 if (rword == RES_IN) {
4679 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4681 if (rword == RES_DONE) {
4682 continue; /* "done" has no cmds too */
4685 #if ENABLE_HUSH_CASE
4686 if (rword == RES_CASE) {
4687 case_word = expand_strvec_to_string(pi->cmds->argv);
4690 if (rword == RES_MATCH) {
4693 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4695 /* all prev words didn't match, does this one match? */
4696 argv = pi->cmds->argv;
4698 char *pattern = expand_string_to_string(*argv);
4699 /* TODO: which FNM_xxx flags to use? */
4700 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4702 if (cond_code == 0) { /* match! we will execute this branch */
4703 free(case_word); /* make future "word)" stop */
4711 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4713 continue; /* not matched yet, skip this pipe */
4716 /* Just pressing <enter> in shell should check for jobs.
4717 * OTOH, in non-interactive shell this is useless
4718 * and only leads to extra job checks */
4719 if (pi->num_cmds == 0) {
4720 if (G_interactive_fd)
4721 goto check_jobs_and_continue;
4725 /* After analyzing all keywords and conditions, we decided
4726 * to execute this pipe. NB: have to do checkjobs(NULL)
4727 * after run_pipe to collect any background children,
4728 * even if list execution is to be stopped. */
4729 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4732 #if ENABLE_HUSH_LOOPS
4733 G.flag_break_continue = 0;
4735 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4737 /* We ran a builtin, function, or group.
4738 * rcode is already known
4739 * and we don't need to wait for anything. */
4740 G.last_exitcode = rcode;
4741 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4742 check_and_run_traps(0);
4743 #if ENABLE_HUSH_LOOPS
4744 /* Was it "break" or "continue"? */
4745 if (G.flag_break_continue) {
4746 smallint fbc = G.flag_break_continue;
4747 /* We might fall into outer *loop*,
4748 * don't want to break it too */
4750 G.depth_break_continue--;
4751 if (G.depth_break_continue == 0)
4752 G.flag_break_continue = 0;
4753 /* else: e.g. "continue 2" should *break* once, *then* continue */
4754 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4755 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4756 goto check_jobs_and_break;
4757 /* "continue": simulate end of loop */
4762 #if ENABLE_HUSH_FUNCTIONS
4763 if (G.flag_return_in_progress == 1) {
4764 /* same as "goto check_jobs_and_break" */
4769 } else if (pi->followup == PIPE_BG) {
4770 /* What does bash do with attempts to background builtins? */
4771 /* even bash 3.2 doesn't do that well with nested bg:
4772 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4773 * I'm NOT treating inner &'s as jobs */
4774 check_and_run_traps(0);
4776 if (G.run_list_level == 1)
4779 G.last_exitcode = rcode = EXIT_SUCCESS;
4780 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4783 if (G.run_list_level == 1 && G_interactive_fd) {
4784 /* Waits for completion, then fg's main shell */
4785 rcode = checkjobs_and_fg_shell(pi);
4786 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4787 check_and_run_traps(0);
4790 { /* This one just waits for completion */
4791 rcode = checkjobs(pi);
4792 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4793 check_and_run_traps(0);
4795 G.last_exitcode = rcode;
4799 /* Analyze how result affects subsequent commands */
4801 if (rword == RES_IF || rword == RES_ELIF)
4804 #if ENABLE_HUSH_LOOPS
4805 /* Beware of "while false; true; do ..."! */
4806 if (pi->next && pi->next->res_word == RES_DO) {
4807 if (rword == RES_WHILE) {
4809 /* "while false; do...done" - exitcode 0 */
4810 G.last_exitcode = rcode = EXIT_SUCCESS;
4811 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4812 goto check_jobs_and_break;
4815 if (rword == RES_UNTIL) {
4817 debug_printf_exec(": until expr is true: breaking\n");
4818 check_jobs_and_break:
4826 check_jobs_and_continue:
4833 #if ENABLE_HUSH_LOOPS
4838 #if ENABLE_HUSH_CASE
4842 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4846 /* Select which version we will use */
4847 static int run_and_free_list(struct pipe *pi)
4850 debug_printf_exec("run_and_free_list entered\n");
4852 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4853 rcode = run_list(pi);
4855 /* free_pipe_list has the side effect of clearing memory.
4856 * In the long run that function can be merged with run_list,
4857 * but doing that now would hobble the debugging effort. */
4859 debug_printf_exec("run_and_free_list return %d\n", rcode);
4864 static struct pipe *new_pipe(void)
4867 pi = xzalloc(sizeof(struct pipe));
4868 /*pi->followup = 0; - deliberately invalid value */
4869 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4873 /* Command (member of a pipe) is complete, or we start a new pipe
4874 * if ctx->command is NULL.
4875 * No errors possible here.
4877 static int done_command(struct parse_context *ctx)
4879 /* The command is really already in the pipe structure, so
4880 * advance the pipe counter and make a new, null command. */
4881 struct pipe *pi = ctx->pipe;
4882 struct command *command = ctx->command;
4885 if (IS_NULL_CMD(command)) {
4886 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4890 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4891 //debug_print_tree(ctx->list_head, 20);
4893 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4896 /* Only real trickiness here is that the uncommitted
4897 * command structure is not counted in pi->num_cmds. */
4898 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4899 ctx->command = command = &pi->cmds[pi->num_cmds];
4901 memset(command, 0, sizeof(*command));
4902 return pi->num_cmds; /* used only for 0/nonzero check */
4905 static void done_pipe(struct parse_context *ctx, pipe_style type)
4909 debug_printf_parse("done_pipe entered, followup %d\n", type);
4910 /* Close previous command */
4911 not_null = done_command(ctx);
4912 ctx->pipe->followup = type;
4914 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4915 ctx->ctx_inverted = 0;
4916 ctx->pipe->res_word = ctx->ctx_res_w;
4919 /* Without this check, even just <enter> on command line generates
4920 * tree of three NOPs (!). Which is harmless but annoying.
4921 * IOW: it is safe to do it unconditionally. */
4924 || ctx->ctx_res_w == RES_FI
4926 #if ENABLE_HUSH_LOOPS
4927 || ctx->ctx_res_w == RES_DONE
4928 || ctx->ctx_res_w == RES_FOR
4929 || ctx->ctx_res_w == RES_IN
4931 #if ENABLE_HUSH_CASE
4932 || ctx->ctx_res_w == RES_ESAC
4936 debug_printf_parse("done_pipe: adding new pipe: "
4937 "not_null:%d ctx->ctx_res_w:%d\n",
4938 not_null, ctx->ctx_res_w);
4940 ctx->pipe->next = new_p;
4942 /* RES_THEN, RES_DO etc are "sticky" -
4943 * they remain set for pipes inside if/while.
4944 * This is used to control execution.
4945 * RES_FOR and RES_IN are NOT sticky (needed to support
4946 * cases where variable or value happens to match a keyword):
4948 #if ENABLE_HUSH_LOOPS
4949 if (ctx->ctx_res_w == RES_FOR
4950 || ctx->ctx_res_w == RES_IN)
4951 ctx->ctx_res_w = RES_NONE;
4953 #if ENABLE_HUSH_CASE
4954 if (ctx->ctx_res_w == RES_MATCH)
4955 ctx->ctx_res_w = RES_CASE_BODY;
4956 if (ctx->ctx_res_w == RES_CASE)
4957 ctx->ctx_res_w = RES_CASE_IN;
4959 ctx->command = NULL; /* trick done_command below */
4960 /* Create the memory for command, roughly:
4961 * ctx->pipe->cmds = new struct command;
4962 * ctx->command = &ctx->pipe->cmds[0];
4965 //debug_print_tree(ctx->list_head, 10);
4967 debug_printf_parse("done_pipe return\n");
4970 static void initialize_context(struct parse_context *ctx)
4972 memset(ctx, 0, sizeof(*ctx));
4973 ctx->pipe = ctx->list_head = new_pipe();
4974 /* Create the memory for command, roughly:
4975 * ctx->pipe->cmds = new struct command;
4976 * ctx->command = &ctx->pipe->cmds[0];
4981 /* If a reserved word is found and processed, parse context is modified
4982 * and 1 is returned.
4985 struct reserved_combo {
4988 unsigned char assignment_flag;
4992 FLAG_END = (1 << RES_NONE ),
4994 FLAG_IF = (1 << RES_IF ),
4995 FLAG_THEN = (1 << RES_THEN ),
4996 FLAG_ELIF = (1 << RES_ELIF ),
4997 FLAG_ELSE = (1 << RES_ELSE ),
4998 FLAG_FI = (1 << RES_FI ),
5000 # if ENABLE_HUSH_LOOPS
5001 FLAG_FOR = (1 << RES_FOR ),
5002 FLAG_WHILE = (1 << RES_WHILE),
5003 FLAG_UNTIL = (1 << RES_UNTIL),
5004 FLAG_DO = (1 << RES_DO ),
5005 FLAG_DONE = (1 << RES_DONE ),
5006 FLAG_IN = (1 << RES_IN ),
5008 # if ENABLE_HUSH_CASE
5009 FLAG_MATCH = (1 << RES_MATCH),
5010 FLAG_ESAC = (1 << RES_ESAC ),
5012 FLAG_START = (1 << RES_XXXX ),
5015 static const struct reserved_combo* match_reserved_word(o_string *word)
5017 /* Mostly a list of accepted follow-up reserved words.
5018 * FLAG_END means we are done with the sequence, and are ready
5019 * to turn the compound list into a command.
5020 * FLAG_START means the word must start a new compound list.
5022 static const struct reserved_combo reserved_list[] = {
5024 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5025 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5026 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5027 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5028 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5029 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5031 # if ENABLE_HUSH_LOOPS
5032 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5033 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5034 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5035 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5036 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5037 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5039 # if ENABLE_HUSH_CASE
5040 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5041 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5044 const struct reserved_combo *r;
5046 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5047 if (strcmp(word->data, r->literal) == 0)
5052 /* Return 0: not a keyword, 1: keyword
5054 static int reserved_word(o_string *word, struct parse_context *ctx)
5056 # if ENABLE_HUSH_CASE
5057 static const struct reserved_combo reserved_match = {
5058 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5061 const struct reserved_combo *r;
5065 r = match_reserved_word(word);
5069 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5070 # if ENABLE_HUSH_CASE
5071 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5072 /* "case word IN ..." - IN part starts first MATCH part */
5073 r = &reserved_match;
5076 if (r->flag == 0) { /* '!' */
5077 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5078 syntax_error("! ! command");
5079 ctx->ctx_res_w = RES_SNTX;
5081 ctx->ctx_inverted = 1;
5084 if (r->flag & FLAG_START) {
5085 struct parse_context *old;
5087 old = xmalloc(sizeof(*old));
5088 debug_printf_parse("push stack %p\n", old);
5089 *old = *ctx; /* physical copy */
5090 initialize_context(ctx);
5092 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5093 syntax_error_at(word->data);
5094 ctx->ctx_res_w = RES_SNTX;
5097 /* "{...} fi" is ok. "{...} if" is not
5099 * if { echo foo; } then { echo bar; } fi */
5100 if (ctx->command->group)
5101 done_pipe(ctx, PIPE_SEQ);
5104 ctx->ctx_res_w = r->res;
5105 ctx->old_flag = r->flag;
5106 word->o_assignment = r->assignment_flag;
5108 if (ctx->old_flag & FLAG_END) {
5109 struct parse_context *old;
5111 done_pipe(ctx, PIPE_SEQ);
5112 debug_printf_parse("pop stack %p\n", ctx->stack);
5114 old->command->group = ctx->list_head;
5115 old->command->cmd_type = CMD_NORMAL;
5117 o_addstr(&old->as_string, ctx->as_string.data);
5118 o_free_unsafe(&ctx->as_string);
5119 old->command->group_as_string = xstrdup(old->as_string.data);
5120 debug_printf_parse("pop, remembering as:'%s'\n",
5121 old->command->group_as_string);
5123 *ctx = *old; /* physical copy */
5128 #endif /* HAS_KEYWORDS */
5130 /* Word is complete, look at it and update parsing context.
5131 * Normal return is 0. Syntax errors return 1.
5132 * Note: on return, word is reset, but not o_free'd!
5134 static int done_word(o_string *word, struct parse_context *ctx)
5136 struct command *command = ctx->command;
5138 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5139 if (word->length == 0 && word->o_quoted == 0) {
5140 debug_printf_parse("done_word return 0: true null, ignored\n");
5144 if (ctx->pending_redirect) {
5145 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5146 * only if run as "bash", not "sh" */
5147 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5149 * ...the word that follows the redirection operator
5150 * shall be subjected to tilde expansion, parameter expansion,
5151 * command substitution, arithmetic expansion, and quote
5152 * removal. Pathname expansion shall not be performed
5153 * on the word by a non-interactive shell; an interactive
5154 * shell may perform it, but shall do so only when
5155 * the expansion would result in one word."
5157 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5158 /* Cater for >\file case:
5159 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5160 * Same with heredocs:
5161 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5163 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5164 unbackslash(ctx->pending_redirect->rd_filename);
5165 /* Is it <<"HEREDOC"? */
5166 if (word->o_quoted) {
5167 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5170 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5171 ctx->pending_redirect = NULL;
5173 /* If this word wasn't an assignment, next ones definitely
5174 * can't be assignments. Even if they look like ones. */
5175 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5176 && word->o_assignment != WORD_IS_KEYWORD
5178 word->o_assignment = NOT_ASSIGNMENT;
5180 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5181 command->assignment_cnt++;
5182 word->o_assignment = MAYBE_ASSIGNMENT;
5186 # if ENABLE_HUSH_CASE
5187 if (ctx->ctx_dsemicolon
5188 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5190 /* already done when ctx_dsemicolon was set to 1: */
5191 /* ctx->ctx_res_w = RES_MATCH; */
5192 ctx->ctx_dsemicolon = 0;
5195 if (!command->argv /* if it's the first word... */
5196 # if ENABLE_HUSH_LOOPS
5197 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5198 && ctx->ctx_res_w != RES_IN
5200 # if ENABLE_HUSH_CASE
5201 && ctx->ctx_res_w != RES_CASE
5204 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5205 if (reserved_word(word, ctx)) {
5206 o_reset_to_empty_unquoted(word);
5207 debug_printf_parse("done_word return %d\n",
5208 (ctx->ctx_res_w == RES_SNTX));
5209 return (ctx->ctx_res_w == RES_SNTX);
5211 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5212 if (strcmp(word->data, "export") == 0
5213 # if ENABLE_HUSH_LOCAL
5214 || strcmp(word->data, "local") == 0
5217 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5220 # if ENABLE_HUSH_BASH_COMPAT
5221 if (strcmp(word->data, "[[") == 0) {
5222 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5228 if (command->group) {
5229 /* "{ echo foo; } echo bar" - bad */
5230 syntax_error_at(word->data);
5231 debug_printf_parse("done_word return 1: syntax error, "
5232 "groups and arglists don't mix\n");
5235 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5236 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5237 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5238 /* (otherwise it's known to be not empty and is already safe) */
5240 /* exclude "$@" - it can expand to no word despite "" */
5241 char *p = word->data;
5242 while (p[0] == SPECIAL_VAR_SYMBOL
5243 && (p[1] & 0x7f) == '@'
5244 && p[2] == SPECIAL_VAR_SYMBOL
5248 if (p == word->data || p[0] != '\0') {
5249 /* saw no "$@", or not only "$@" but some
5250 * real text is there too */
5251 /* insert "empty variable" reference, this makes
5252 * e.g. "", $empty"" etc to not disappear */
5253 o_addchr(word, SPECIAL_VAR_SYMBOL);
5254 o_addchr(word, SPECIAL_VAR_SYMBOL);
5257 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5258 debug_print_strings("word appended to argv", command->argv);
5261 #if ENABLE_HUSH_LOOPS
5262 if (ctx->ctx_res_w == RES_FOR) {
5264 || !is_well_formed_var_name(command->argv[0], '\0')
5266 /* bash says just "not a valid identifier" */
5267 syntax_error("not a valid identifier in for");
5270 /* Force FOR to have just one word (variable name) */
5271 /* NB: basically, this makes hush see "for v in ..."
5272 * syntax as if it is "for v; in ...". FOR and IN become
5273 * two pipe structs in parse tree. */
5274 done_pipe(ctx, PIPE_SEQ);
5277 #if ENABLE_HUSH_CASE
5278 /* Force CASE to have just one word */
5279 if (ctx->ctx_res_w == RES_CASE) {
5280 done_pipe(ctx, PIPE_SEQ);
5284 o_reset_to_empty_unquoted(word);
5286 debug_printf_parse("done_word return 0\n");
5291 /* Peek ahead in the input to find out if we have a "&n" construct,
5292 * as in "2>&1", that represents duplicating a file descriptor.
5294 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5295 * REDIRFD_SYNTAX_ERR if syntax error,
5296 * REDIRFD_TO_FILE if no & was seen,
5297 * or the number found.
5300 #define parse_redir_right_fd(as_string, input) \
5301 parse_redir_right_fd(input)
5303 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5309 return REDIRFD_TO_FILE;
5311 ch = i_getch(input); /* get the & */
5312 nommu_addchr(as_string, ch);
5315 ch = i_getch(input);
5316 nommu_addchr(as_string, ch);
5317 return REDIRFD_CLOSE;
5321 while (ch != EOF && isdigit(ch)) {
5322 d = d*10 + (ch-'0');
5324 ch = i_getch(input);
5325 nommu_addchr(as_string, ch);
5330 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5332 bb_error_msg("ambiguous redirect");
5333 return REDIRFD_SYNTAX_ERR;
5336 /* Return code is 0 normal, 1 if a syntax error is detected
5338 static int parse_redirect(struct parse_context *ctx,
5341 struct in_str *input)
5343 struct command *command = ctx->command;
5344 struct redir_struct *redir;
5345 struct redir_struct **redirp;
5348 dup_num = REDIRFD_TO_FILE;
5349 if (style != REDIRECT_HEREDOC) {
5350 /* Check for a '>&1' type redirect */
5351 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5352 if (dup_num == REDIRFD_SYNTAX_ERR)
5355 int ch = i_peek(input);
5356 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5357 if (dup_num) { /* <<-... */
5358 ch = i_getch(input);
5359 nommu_addchr(&ctx->as_string, ch);
5364 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5365 int ch = i_peek(input);
5367 /* >|FILE redirect ("clobbering" >).
5368 * Since we do not support "set -o noclobber" yet,
5369 * >| and > are the same for now. Just eat |.
5371 ch = i_getch(input);
5372 nommu_addchr(&ctx->as_string, ch);
5376 /* Create a new redir_struct and append it to the linked list */
5377 redirp = &command->redirects;
5378 while ((redir = *redirp) != NULL) {
5379 redirp = &(redir->next);
5381 *redirp = redir = xzalloc(sizeof(*redir));
5382 /* redir->next = NULL; */
5383 /* redir->rd_filename = NULL; */
5384 redir->rd_type = style;
5385 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5387 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5388 redir_table[style].descrip);
5390 redir->rd_dup = dup_num;
5391 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5392 /* Erik had a check here that the file descriptor in question
5393 * is legit; I postpone that to "run time"
5394 * A "-" representation of "close me" shows up as a -3 here */
5395 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5396 redir->rd_fd, redir->rd_dup);
5398 /* Set ctx->pending_redirect, so we know what to do at the
5399 * end of the next parsed word. */
5400 ctx->pending_redirect = redir;
5405 /* If a redirect is immediately preceded by a number, that number is
5406 * supposed to tell which file descriptor to redirect. This routine
5407 * looks for such preceding numbers. In an ideal world this routine
5408 * needs to handle all the following classes of redirects...
5409 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5410 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5411 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5412 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5414 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5416 * ... If n is quoted, the number shall not be recognized as part of
5417 * the redirection expression. For example:
5419 * writes the character 2 into file a"
5420 * We are getting it right by setting ->o_quoted on any \<char>
5422 * A -1 return means no valid number was found,
5423 * the caller should use the appropriate default for this redirection.
5425 static int redirect_opt_num(o_string *o)
5429 if (o->data == NULL)
5431 num = bb_strtou(o->data, NULL, 10);
5432 if (errno || num < 0)
5434 o_reset_to_empty_unquoted(o);
5439 #define fetch_till_str(as_string, input, word, skip_tabs) \
5440 fetch_till_str(input, word, skip_tabs)
5442 static char *fetch_till_str(o_string *as_string,
5443 struct in_str *input,
5447 o_string heredoc = NULL_O_STRING;
5453 ch = i_getch(input);
5454 nommu_addchr(as_string, ch);
5456 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5457 heredoc.data[past_EOL] = '\0';
5458 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5459 return heredoc.data;
5462 o_addchr(&heredoc, ch);
5463 past_EOL = heredoc.length;
5466 ch = i_getch(input);
5467 nommu_addchr(as_string, ch);
5468 } while (skip_tabs && ch == '\t');
5469 } while (ch == '\n');
5472 o_free_unsafe(&heredoc);
5475 o_addchr(&heredoc, ch);
5476 nommu_addchr(as_string, ch);
5480 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5481 * and load them all. There should be exactly heredoc_cnt of them.
5483 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5485 struct pipe *pi = ctx->list_head;
5487 while (pi && heredoc_cnt) {
5489 struct command *cmd = pi->cmds;
5491 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5493 cmd->argv ? cmd->argv[0] : "NONE");
5494 for (i = 0; i < pi->num_cmds; i++) {
5495 struct redir_struct *redir = cmd->redirects;
5497 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5498 i, cmd->argv ? cmd->argv[0] : "NONE");
5500 if (redir->rd_type == REDIRECT_HEREDOC) {
5503 redir->rd_type = REDIRECT_HEREDOC2;
5504 /* redir->rd_dup is (ab)used to indicate <<- */
5505 p = fetch_till_str(&ctx->as_string, input,
5506 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5508 syntax_error("unexpected EOF in here document");
5511 free(redir->rd_filename);
5512 redir->rd_filename = p;
5515 redir = redir->next;
5522 /* Should be 0. If it isn't, it's a parse error */
5524 bb_error_msg_and_die("heredoc BUG 2");
5530 #if ENABLE_HUSH_TICK
5531 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5536 char **to_free = NULL;
5540 pid = BB_MMU ? fork() : vfork();
5542 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5544 if (pid == 0) { /* child */
5545 disable_restore_tty_pgrp_on_exit();
5546 /* Process substitution is not considered to be usual
5547 * 'command execution'.
5548 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5555 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5556 close(channel[0]); /* NB: close _first_, then move fd! */
5557 xmove_fd(channel[1], 1);
5558 /* Prevent it from trying to handle ctrl-z etc */
5559 IF_HUSH_JOB(G.run_list_level = 1;)
5560 /* Awful hack for `trap` or $(trap).
5562 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5563 * contains an example where "trap" is executed in a subshell:
5565 * save_traps=$(trap)
5567 * eval "$save_traps"
5569 * Standard does not say that "trap" in subshell shall print
5570 * parent shell's traps. It only says that its output
5571 * must have suitable form, but then, in the above example
5572 * (which is not supposed to be normative), it implies that.
5574 * bash (and probably other shell) does implement it
5575 * (traps are reset to defaults, but "trap" still shows them),
5576 * but as a result, "trap" logic is hopelessly messed up:
5579 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5580 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5581 * # true | trap <--- trap is in subshell - no output (ditto)
5582 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5583 * trap -- 'echo Ho' SIGWINCH
5584 * # echo `(trap)` <--- in subshell in subshell - output
5585 * trap -- 'echo Ho' SIGWINCH
5586 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5587 * trap -- 'echo Ho' SIGWINCH
5589 * The rules when to forget and when to not forget traps
5590 * get really complex and nonsensical.
5592 * Our solution: ONLY bare $(trap) or `trap` is special.
5594 s = skip_whitespace(s);
5595 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5597 static const char *const argv[] = { NULL, NULL };
5598 builtin_trap((char**)argv);
5599 exit(0); /* not _exit() - we need to fflush */
5602 reset_traps_to_defaults();
5603 parse_and_run_string(s);
5604 _exit(G.last_exitcode);
5606 /* We re-execute after vfork on NOMMU. This makes this script safe:
5607 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5608 * huge=`cat BIG` # was blocking here forever
5611 re_execute_shell(&to_free,
5621 # if ENABLE_HUSH_FAST
5623 //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);
5625 enable_restore_tty_pgrp_on_exit();
5630 close_on_exec_on(channel[0]);
5631 return xfdopen_for_read(channel[0]);
5634 /* Return code is exit status of the process that is run. */
5635 static int process_command_subs(o_string *dest, const char *s)
5638 struct in_str pipe_str;
5640 int status, ch, eol_cnt;
5642 fp = generate_stream_from_string(s, &pid);
5644 /* Now send results of command back into original context */
5645 setup_file_in_str(&pipe_str, fp);
5647 while ((ch = i_getch(&pipe_str)) != EOF) {
5653 o_addchr(dest, '\n');
5656 o_addQchr(dest, ch);
5659 debug_printf("done reading from `cmd` pipe, closing it\n");
5661 /* We need to extract exitcode. Test case
5662 * "true; echo `sleep 1; false` $?"
5664 safe_waitpid(pid, &status, 0);
5665 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5666 return WEXITSTATUS(status);
5668 #endif /* ENABLE_HUSH_TICK */
5670 #if !ENABLE_HUSH_FUNCTIONS
5671 #define parse_group(dest, ctx, input, ch) \
5672 parse_group(ctx, input, ch)
5674 static int parse_group(o_string *dest, struct parse_context *ctx,
5675 struct in_str *input, int ch)
5677 /* dest contains characters seen prior to ( or {.
5678 * Typically it's empty, but for function defs,
5679 * it contains function name (without '()'). */
5680 struct pipe *pipe_list;
5682 struct command *command = ctx->command;
5684 debug_printf_parse("parse_group entered\n");
5685 #if ENABLE_HUSH_FUNCTIONS
5686 if (ch == '(' && !dest->o_quoted) {
5688 if (done_word(dest, ctx))
5691 goto skip; /* (... */
5692 if (command->argv[1]) { /* word word ... (... */
5693 syntax_error_unexpected_ch('(');
5696 /* it is "word(..." or "word (..." */
5698 ch = i_getch(input);
5699 while (ch == ' ' || ch == '\t');
5701 syntax_error_unexpected_ch(ch);
5704 nommu_addchr(&ctx->as_string, ch);
5706 ch = i_getch(input);
5707 while (ch == ' ' || ch == '\t' || ch == '\n');
5709 syntax_error_unexpected_ch(ch);
5712 nommu_addchr(&ctx->as_string, ch);
5713 command->cmd_type = CMD_FUNCDEF;
5718 #if 0 /* Prevented by caller */
5719 if (command->argv /* word [word]{... */
5720 || dest->length /* word{... */
5721 || dest->o_quoted /* ""{... */
5724 debug_printf_parse("parse_group return 1: "
5725 "syntax error, groups and arglists don't mix\n");
5730 #if ENABLE_HUSH_FUNCTIONS
5736 command->cmd_type = CMD_SUBSHELL;
5738 /* bash does not allow "{echo...", requires whitespace */
5739 ch = i_getch(input);
5740 if (ch != ' ' && ch != '\t' && ch != '\n') {
5741 syntax_error_unexpected_ch(ch);
5744 nommu_addchr(&ctx->as_string, ch);
5749 char *as_string = NULL;
5751 pipe_list = parse_stream(&as_string, input, endch);
5754 o_addstr(&ctx->as_string, as_string);
5756 /* empty ()/{} or parse error? */
5757 if (!pipe_list || pipe_list == ERR_PTR) {
5758 /* parse_stream already emitted error msg */
5762 debug_printf_parse("parse_group return 1: "
5763 "parse_stream returned %p\n", pipe_list);
5766 command->group = pipe_list;
5768 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5769 command->group_as_string = as_string;
5770 debug_printf_parse("end of group, remembering as:'%s'\n",
5771 command->group_as_string);
5774 debug_printf_parse("parse_group return 0\n");
5776 /* command remains "open", available for possible redirects */
5779 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5780 /* Subroutines for copying $(...) and `...` things */
5781 static void add_till_backquote(o_string *dest, struct in_str *input);
5783 static void add_till_single_quote(o_string *dest, struct in_str *input)
5786 int ch = i_getch(input);
5788 syntax_error_unterm_ch('\'');
5789 /*xfunc_die(); - redundant */
5796 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5797 static void add_till_double_quote(o_string *dest, struct in_str *input)
5800 int ch = i_getch(input);
5802 syntax_error_unterm_ch('"');
5803 /*xfunc_die(); - redundant */
5807 if (ch == '\\') { /* \x. Copy both chars. */
5809 ch = i_getch(input);
5813 add_till_backquote(dest, input);
5817 //if (ch == '$') ...
5820 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5822 * "Within the backquoted style of command substitution, backslash
5823 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5824 * The search for the matching backquote shall be satisfied by the first
5825 * backquote found without a preceding backslash; during this search,
5826 * if a non-escaped backquote is encountered within a shell comment,
5827 * a here-document, an embedded command substitution of the $(command)
5828 * form, or a quoted string, undefined results occur. A single-quoted
5829 * or double-quoted string that begins, but does not end, within the
5830 * "`...`" sequence produces undefined results."
5832 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5834 static void add_till_backquote(o_string *dest, struct in_str *input)
5837 int ch = i_getch(input);
5839 syntax_error_unterm_ch('`');
5840 /*xfunc_die(); - redundant */
5845 /* \x. Copy both chars unless it is \` */
5846 int ch2 = i_getch(input);
5848 syntax_error_unterm_ch('`');
5849 /*xfunc_die(); - redundant */
5851 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5858 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5859 * quoting and nested ()s.
5860 * "With the $(command) style of command substitution, all characters
5861 * following the open parenthesis to the matching closing parenthesis
5862 * constitute the command. Any valid shell script can be used for command,
5863 * except a script consisting solely of redirections which produces
5864 * unspecified results."
5866 * echo $(echo '(TEST)' BEST) (TEST) BEST
5867 * echo $(echo 'TEST)' BEST) TEST) BEST
5868 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5870 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5874 int ch = i_getch(input);
5876 syntax_error_unterm_ch(')');
5877 /*xfunc_die(); - redundant */
5885 if (i_peek(input) == ')') {
5893 add_till_single_quote(dest, input);
5898 add_till_double_quote(dest, input);
5903 /* \x. Copy verbatim. Important for \(, \) */
5904 ch = i_getch(input);
5906 syntax_error_unterm_ch(')');
5907 /*xfunc_die(); - redundant */
5914 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5916 /* Return code: 0 for OK, 1 for syntax error */
5918 #define handle_dollar(as_string, dest, input) \
5919 handle_dollar(dest, input)
5921 static int handle_dollar(o_string *as_string,
5923 struct in_str *input)
5925 int ch = i_peek(input); /* first character after the $ */
5926 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5928 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5930 ch = i_getch(input);
5931 nommu_addchr(as_string, ch);
5933 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5935 debug_printf_parse(": '%c'\n", ch);
5936 o_addchr(dest, ch | quote_mask);
5939 if (!isalnum(ch) && ch != '_')
5941 ch = i_getch(input);
5942 nommu_addchr(as_string, ch);
5944 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5945 } else if (isdigit(ch)) {
5947 ch = i_getch(input);
5948 nommu_addchr(as_string, ch);
5949 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5950 debug_printf_parse(": '%c'\n", ch);
5951 o_addchr(dest, ch | quote_mask);
5952 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5953 } else switch (ch) {
5955 case '!': /* last bg pid */
5956 case '?': /* last exit code */
5957 case '#': /* number of args */
5958 case '*': /* args */
5959 case '@': /* args */
5960 goto make_one_char_var;
5962 bool first_char, all_digits;
5963 bool in_expansion_param;
5965 ch = i_getch(input);
5966 nommu_addchr(as_string, ch);
5967 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5969 // TODO: need to handle "a=ab}; echo ${a%\}}"
5970 // and "a=abc; c=c; echo ${a%${c}}"
5971 in_expansion_param = false;
5975 ch = i_getch(input);
5976 nommu_addchr(as_string, ch);
5983 /* ${#var}: length of var contents */
5990 /* They're being verbose and doing ${?} */
5991 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5995 if (!in_expansion_param
5996 && ( (all_digits && !isdigit(ch)) /* met non-digit: 123w */
5997 || (!all_digits && !isalnum(ch) && ch != '_') /* met non-name char: abc% */
6000 /* handle parameter expansions
6001 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6003 if (first_char /* bad (empty var name): "${%..." */
6004 || !strchr("%#:-=+?", ch) /* bad: "${var<bad_char>..." */
6006 syntax_error_unterm_str("${name}");
6007 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
6010 in_expansion_param = true;
6013 debug_printf_parse(": '%c'\n", ch);
6014 o_addchr(dest, ch | quote_mask);
6018 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6021 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6026 ch = i_getch(input);
6027 nommu_addchr(as_string, ch);
6028 # if ENABLE_SH_MATH_SUPPORT
6029 if (i_peek(input) == '(') {
6030 ch = i_getch(input);
6031 nommu_addchr(as_string, ch);
6032 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6033 o_addchr(dest, /*quote_mask |*/ '+');
6037 add_till_closing_paren(dest, input, true);
6040 o_addstr(as_string, dest->data + pos);
6041 o_addchr(as_string, ')');
6042 o_addchr(as_string, ')');
6045 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6049 # if ENABLE_HUSH_TICK
6050 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6051 o_addchr(dest, quote_mask | '`');
6055 add_till_closing_paren(dest, input, false);
6058 o_addstr(as_string, dest->data + pos);
6059 o_addchr(as_string, ')');
6062 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6068 ch = i_getch(input);
6069 nommu_addchr(as_string, ch);
6071 if (isalnum(ch)) { /* it's $_name or $_123 */
6076 /* TODO: $_ and $-: */
6077 /* $_ Shell or shell script name; or last argument of last command
6078 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6079 * but in command's env, set to full pathname used to invoke it */
6080 /* $- Option flags set by set builtin or shell options (-i etc) */
6082 o_addQchr(dest, '$');
6084 debug_printf_parse("handle_dollar return 0\n");
6089 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6090 parse_stream_dquoted(dest, input, dquote_end)
6092 static int parse_stream_dquoted(o_string *as_string,
6094 struct in_str *input,
6101 ch = i_getch(input);
6103 nommu_addchr(as_string, ch);
6104 if (ch == dquote_end) { /* may be only '"' or EOF */
6105 if (dest->o_assignment == NOT_ASSIGNMENT)
6106 dest->o_escape ^= 1;
6107 debug_printf_parse("parse_stream_dquoted return 0\n");
6110 /* note: can't move it above ch == dquote_end check! */
6112 syntax_error_unterm_ch('"');
6113 /*xfunc_die(); - redundant */
6117 next = i_peek(input);
6119 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6120 ch, ch, dest->o_escape);
6123 syntax_error("\\<eof>");
6127 * "The backslash retains its special meaning [in "..."]
6128 * only when followed by one of the following characters:
6129 * $, `, ", \, or <newline>. A double quote may be quoted
6130 * within double quotes by preceding it with a backslash."
6132 if (strchr("$`\"\\\n", next) != NULL) {
6133 ch = i_getch(input);
6135 o_addqchr(dest, ch);
6136 nommu_addchr(as_string, ch);
6139 o_addqchr(dest, '\\');
6140 nommu_addchr(as_string, '\\');
6145 if (handle_dollar(as_string, dest, input) != 0) {
6146 debug_printf_parse("parse_stream_dquoted return 1: "
6147 "handle_dollar returned non-0\n");
6152 #if ENABLE_HUSH_TICK
6154 //int pos = dest->length;
6155 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6156 o_addchr(dest, 0x80 | '`');
6157 add_till_backquote(dest, input);
6158 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6159 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6163 o_addQchr(dest, ch);
6165 && (dest->o_assignment == MAYBE_ASSIGNMENT
6166 || dest->o_assignment == WORD_IS_KEYWORD)
6167 && is_well_formed_var_name(dest->data, '=')
6169 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6175 * Scan input until EOF or end_trigger char.
6176 * Return a list of pipes to execute, or NULL on EOF
6177 * or if end_trigger character is met.
6178 * On syntax error, exit is shell is not interactive,
6179 * reset parsing machinery and start parsing anew,
6180 * or return ERR_PTR.
6182 static struct pipe *parse_stream(char **pstring,
6183 struct in_str *input,
6186 struct parse_context ctx;
6187 o_string dest = NULL_O_STRING;
6191 /* Double-quote state is handled in the state variable is_in_dquote.
6192 * A single-quote triggers a bypass of the main loop until its mate is
6193 * found. When recursing, quote state is passed in via dest->o_escape.
6195 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6196 end_trigger ? end_trigger : 'X');
6199 /* If very first arg is "" or '', dest.data may end up NULL.
6200 * Preventing this: */
6201 o_addchr(&dest, '\0');
6204 G.ifs = get_local_var_value("IFS");
6209 #if ENABLE_HUSH_INTERACTIVE
6210 input->promptmode = 0; /* PS1 */
6212 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6213 initialize_context(&ctx);
6218 const char *is_special;
6222 redir_type redir_style;
6225 /* dest.o_quoted = 1; - already is (see below) */
6226 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6229 /* We reached closing '"' */
6232 ch = i_getch(input);
6233 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6234 ch, ch, dest.o_escape);
6239 syntax_error_unterm_str("here document");
6242 /* end_trigger == '}' case errors out earlier,
6243 * checking only ')' */
6244 if (end_trigger == ')') {
6245 syntax_error_unterm_ch('('); /* exits */
6246 /* goto parse_error; */
6249 if (done_word(&dest, &ctx)) {
6253 done_pipe(&ctx, PIPE_SEQ);
6255 /* If we got nothing... */
6256 /* (this makes bare "&" cmd a no-op.
6257 * bash says: "syntax error near unexpected token '&'") */
6258 if (pi->num_cmds == 0
6259 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6265 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6267 *pstring = ctx.as_string.data;
6269 o_free_unsafe(&ctx.as_string);
6272 debug_printf_parse("parse_stream return %p\n", pi);
6275 nommu_addchr(&ctx.as_string, ch);
6279 next = i_peek(input);
6281 is_special = "{}<>;&|()#'" /* special outside of "str" */
6282 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6283 /* Are { and } special here? */
6284 if (ctx.command->argv /* word [word]{... - non-special */
6285 || dest.length /* word{... - non-special */
6286 || dest.o_quoted /* ""{... - non-special */
6287 || (next != ';' /* }; - special */
6288 && next != ')' /* }) - special */
6289 && next != '&' /* }& and }&& ... - special */
6290 && next != '|' /* }|| ... - special */
6291 && !strchr(G.ifs, next) /* {word - non-special */
6294 /* They are not special, skip "{}" */
6297 is_special = strchr(is_special, ch);
6298 is_ifs = strchr(G.ifs, ch);
6300 if (!is_special && !is_ifs) { /* ordinary char */
6302 o_addQchr(&dest, ch);
6303 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6304 || dest.o_assignment == WORD_IS_KEYWORD)
6306 && is_well_formed_var_name(dest.data, '=')
6308 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6314 if (done_word(&dest, &ctx)) {
6318 #if ENABLE_HUSH_CASE
6319 /* "case ... in <newline> word) ..." -
6320 * newlines are ignored (but ';' wouldn't be) */
6321 if (ctx.command->argv == NULL
6322 && ctx.ctx_res_w == RES_MATCH
6327 /* Treat newline as a command separator. */
6328 done_pipe(&ctx, PIPE_SEQ);
6329 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6331 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6336 dest.o_assignment = MAYBE_ASSIGNMENT;
6338 /* note: if (is_ifs) continue;
6339 * will still trigger for us */
6343 /* "cmd}" or "cmd }..." without semicolon or &:
6344 * } is an ordinary char in this case, even inside { cmd; }
6345 * Pathological example: { ""}; } should exec "}" cmd
6348 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6349 || dest.length != 0 /* word} */
6350 || dest.o_quoted /* ""} */
6354 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6355 goto skip_end_trigger;
6356 /* else: } does terminate a group */
6359 if (end_trigger && end_trigger == ch
6360 && (ch != ';' || heredoc_cnt == 0)
6361 #if ENABLE_HUSH_CASE
6363 || ctx.ctx_res_w != RES_MATCH
6364 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6369 /* This is technically valid:
6370 * { cat <<HERE; }; echo Ok
6374 * but we don't support this.
6375 * We require heredoc to be in enclosing {}/(),
6378 syntax_error_unterm_str("here document");
6381 if (done_word(&dest, &ctx)) {
6384 done_pipe(&ctx, PIPE_SEQ);
6385 dest.o_assignment = MAYBE_ASSIGNMENT;
6386 /* Do we sit outside of any if's, loops or case's? */
6388 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6392 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6394 *pstring = ctx.as_string.data;
6396 o_free_unsafe(&ctx.as_string);
6399 debug_printf_parse("parse_stream return %p: "
6400 "end_trigger char found\n",
6402 return ctx.list_head;
6409 /* Catch <, > before deciding whether this word is
6410 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6413 redir_fd = redirect_opt_num(&dest);
6414 if (done_word(&dest, &ctx)) {
6417 redir_style = REDIRECT_OVERWRITE;
6419 redir_style = REDIRECT_APPEND;
6420 ch = i_getch(input);
6421 nommu_addchr(&ctx.as_string, ch);
6424 else if (next == '(') {
6425 syntax_error(">(process) not supported");
6429 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6431 continue; /* back to top of while (1) */
6433 redir_fd = redirect_opt_num(&dest);
6434 if (done_word(&dest, &ctx)) {
6437 redir_style = REDIRECT_INPUT;
6439 redir_style = REDIRECT_HEREDOC;
6441 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6442 ch = i_getch(input);
6443 nommu_addchr(&ctx.as_string, ch);
6444 } else if (next == '>') {
6445 redir_style = REDIRECT_IO;
6446 ch = i_getch(input);
6447 nommu_addchr(&ctx.as_string, ch);
6450 else if (next == '(') {
6451 syntax_error("<(process) not supported");
6455 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6457 continue; /* back to top of while (1) */
6460 if (dest.o_assignment == MAYBE_ASSIGNMENT
6461 /* check that we are not in word in "a=1 2>word b=1": */
6462 && !ctx.pending_redirect
6464 /* ch is a special char and thus this word
6465 * cannot be an assignment */
6466 dest.o_assignment = NOT_ASSIGNMENT;
6469 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6473 if (dest.length == 0) {
6476 if (ch == EOF || ch == '\n')
6479 /* note: we do not add it to &ctx.as_string */
6481 nommu_addchr(&ctx.as_string, '\n');
6483 o_addQchr(&dest, ch);
6488 syntax_error("\\<eof>");
6491 ch = i_getch(input);
6493 o_addchr(&dest, '\\');
6494 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6495 o_addchr(&dest, ch);
6496 nommu_addchr(&ctx.as_string, ch);
6497 /* Example: echo Hello \2>file
6498 * we need to know that word 2 is quoted */
6503 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6504 ctx.as_string.data[--ctx.as_string.length] = '\0';
6509 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6510 debug_printf_parse("parse_stream parse error: "
6511 "handle_dollar returned non-0\n");
6518 ch = i_getch(input);
6520 syntax_error_unterm_ch('\'');
6521 /*xfunc_die(); - redundant */
6523 nommu_addchr(&ctx.as_string, ch);
6526 o_addqchr(&dest, ch);
6531 is_in_dquote ^= 1; /* invert */
6532 if (dest.o_assignment == NOT_ASSIGNMENT)
6535 #if ENABLE_HUSH_TICK
6540 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6541 o_addchr(&dest, '`');
6545 add_till_backquote(&dest, input);
6547 o_addstr(&ctx.as_string, dest.data + pos);
6548 o_addchr(&ctx.as_string, '`');
6550 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6551 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6556 #if ENABLE_HUSH_CASE
6559 if (done_word(&dest, &ctx)) {
6562 done_pipe(&ctx, PIPE_SEQ);
6563 #if ENABLE_HUSH_CASE
6564 /* Eat multiple semicolons, detect
6565 * whether it means something special */
6570 ch = i_getch(input);
6571 nommu_addchr(&ctx.as_string, ch);
6572 if (ctx.ctx_res_w == RES_CASE_BODY) {
6573 ctx.ctx_dsemicolon = 1;
6574 ctx.ctx_res_w = RES_MATCH;
6580 /* We just finished a cmd. New one may start
6581 * with an assignment */
6582 dest.o_assignment = MAYBE_ASSIGNMENT;
6585 if (done_word(&dest, &ctx)) {
6589 ch = i_getch(input);
6590 nommu_addchr(&ctx.as_string, ch);
6591 done_pipe(&ctx, PIPE_AND);
6593 done_pipe(&ctx, PIPE_BG);
6597 if (done_word(&dest, &ctx)) {
6600 #if ENABLE_HUSH_CASE
6601 if (ctx.ctx_res_w == RES_MATCH)
6602 break; /* we are in case's "word | word)" */
6604 if (next == '|') { /* || */
6605 ch = i_getch(input);
6606 nommu_addchr(&ctx.as_string, ch);
6607 done_pipe(&ctx, PIPE_OR);
6609 /* we could pick up a file descriptor choice here
6610 * with redirect_opt_num(), but bash doesn't do it.
6611 * "echo foo 2| cat" yields "foo 2". */
6614 o_reset_to_empty_unquoted(&ctx.as_string);
6619 #if ENABLE_HUSH_CASE
6620 /* "case... in [(]word)..." - skip '(' */
6621 if (ctx.ctx_res_w == RES_MATCH
6622 && ctx.command->argv == NULL /* not (word|(... */
6623 && dest.length == 0 /* not word(... */
6624 && dest.o_quoted == 0 /* not ""(... */
6630 if (parse_group(&dest, &ctx, input, ch) != 0) {
6635 #if ENABLE_HUSH_CASE
6636 if (ctx.ctx_res_w == RES_MATCH)
6640 /* proper use of this character is caught by end_trigger:
6641 * if we see {, we call parse_group(..., end_trigger='}')
6642 * and it will match } earlier (not here). */
6643 syntax_error_unexpected_ch(ch);
6647 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6653 struct parse_context *pctx;
6654 IF_HAS_KEYWORDS(struct parse_context *p2;)
6656 /* Clean up allocated tree.
6657 * Sample for finding leaks on syntax error recovery path.
6658 * Run it from interactive shell, watch pmap `pidof hush`.
6659 * while if false; then false; fi; do break; fi
6660 * Samples to catch leaks at execution:
6661 * while if (true | {true;}); then echo ok; fi; do break; done
6662 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6666 /* Update pipe/command counts,
6667 * otherwise freeing may miss some */
6668 done_pipe(pctx, PIPE_SEQ);
6669 debug_printf_clean("freeing list %p from ctx %p\n",
6670 pctx->list_head, pctx);
6671 debug_print_tree(pctx->list_head, 0);
6672 free_pipe_list(pctx->list_head);
6673 debug_printf_clean("freed list %p\n", pctx->list_head);
6675 o_free_unsafe(&pctx->as_string);
6677 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6681 IF_HAS_KEYWORDS(pctx = p2;)
6682 } while (HAS_KEYWORDS && pctx);
6683 /* Free text, clear all dest fields */
6685 /* If we are not in top-level parse, we return,
6686 * our caller will propagate error.
6688 if (end_trigger != ';') {
6696 /* Discard cached input, force prompt */
6698 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6703 /* Executing from string: eval, sh -c '...'
6704 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6705 * end_trigger controls how often we stop parsing
6706 * NUL: parse all, execute, return
6707 * ';': parse till ';' or newline, execute, repeat till EOF
6709 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6711 /* Why we need empty flag?
6712 * An obscure corner case "false; ``; echo $?":
6713 * empty command in `` should still set $? to 0.
6714 * But we can't just set $? to 0 at the start,
6715 * this breaks "false; echo `echo $?`" case.
6719 struct pipe *pipe_list;
6721 pipe_list = parse_stream(NULL, inp, end_trigger);
6722 if (!pipe_list) { /* EOF */
6724 G.last_exitcode = 0;
6727 debug_print_tree(pipe_list, 0);
6728 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6729 run_and_free_list(pipe_list);
6734 static void parse_and_run_string(const char *s)
6736 struct in_str input;
6737 setup_string_in_str(&input, s);
6738 parse_and_run_stream(&input, '\0');
6741 static void parse_and_run_file(FILE *f)
6743 struct in_str input;
6744 setup_file_in_str(&input, f);
6745 parse_and_run_stream(&input, ';');
6748 /* Called a few times only (or even once if "sh -c") */
6749 static void init_sigmasks(void)
6753 sigset_t old_blocked_set;
6755 if (!G.inherited_set_is_saved) {
6756 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6757 G.inherited_set = G.blocked_set;
6759 old_blocked_set = G.blocked_set;
6761 mask = (1 << SIGQUIT);
6762 if (G_interactive_fd) {
6763 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6764 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6765 mask |= SPECIAL_JOB_SIGS;
6767 G.non_DFL_mask = mask;
6772 sigaddset(&G.blocked_set, sig);
6776 sigdelset(&G.blocked_set, SIGCHLD);
6778 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6779 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6781 /* POSIX allows shell to re-enable SIGCHLD
6782 * even if it was SIG_IGN on entry */
6783 #if ENABLE_HUSH_FAST
6784 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6785 if (!G.inherited_set_is_saved)
6786 signal(SIGCHLD, SIGCHLD_handler);
6788 if (!G.inherited_set_is_saved)
6789 signal(SIGCHLD, SIG_DFL);
6792 G.inherited_set_is_saved = 1;
6797 static void maybe_set_to_sigexit(int sig)
6799 void (*handler)(int);
6800 /* non_DFL_mask'ed signals are, well, masked,
6801 * no need to set handler for them.
6803 if (!((G.non_DFL_mask >> sig) & 1)) {
6804 handler = signal(sig, sigexit);
6805 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6806 signal(sig, handler);
6809 /* Set handlers to restore tty pgrp and exit */
6810 static void set_fatal_handlers(void)
6812 /* We _must_ restore tty pgrp on fatal signals */
6814 maybe_set_to_sigexit(SIGILL );
6815 maybe_set_to_sigexit(SIGFPE );
6816 maybe_set_to_sigexit(SIGBUS );
6817 maybe_set_to_sigexit(SIGSEGV);
6818 maybe_set_to_sigexit(SIGTRAP);
6819 } /* else: hush is perfect. what SEGV? */
6820 maybe_set_to_sigexit(SIGABRT);
6821 /* bash 3.2 seems to handle these just like 'fatal' ones */
6822 maybe_set_to_sigexit(SIGPIPE);
6823 maybe_set_to_sigexit(SIGALRM);
6824 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6825 * if we aren't interactive... but in this case
6826 * we never want to restore pgrp on exit, and this fn is not called */
6827 /*maybe_set_to_sigexit(SIGHUP );*/
6828 /*maybe_set_to_sigexit(SIGTERM);*/
6829 /*maybe_set_to_sigexit(SIGINT );*/
6833 static int set_mode(const char cstate, const char mode)
6835 int state = (cstate == '-' ? 1 : 0);
6837 case 'n': G.fake_mode = state; break;
6838 case 'x': /*G.debug_mode = state;*/ break;
6839 default: return EXIT_FAILURE;
6841 return EXIT_SUCCESS;
6844 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6845 int hush_main(int argc, char **argv)
6847 static const struct variable const_shell_ver = {
6849 .varstr = (char*)hush_version_str,
6850 .max_len = 1, /* 0 can provoke free(name) */
6855 unsigned builtin_argc;
6857 struct variable *cur_var;
6860 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6861 G.last_exitcode = EXIT_SUCCESS;
6863 G.argv0_for_re_execing = argv[0];
6865 /* Deal with HUSH_VERSION */
6866 G.shell_ver = const_shell_ver; /* copying struct here */
6867 G.top_var = &G.shell_ver;
6868 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6869 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6870 /* Initialize our shell local variables with the values
6871 * currently living in the environment */
6872 cur_var = G.top_var;
6875 char *value = strchr(*e, '=');
6876 if (value) { /* paranoia */
6877 cur_var->next = xzalloc(sizeof(*cur_var));
6878 cur_var = cur_var->next;
6879 cur_var->varstr = *e;
6880 cur_var->max_len = strlen(*e);
6881 cur_var->flg_export = 1;
6885 /* reinstate HUSH_VERSION */
6886 debug_printf_env("putenv '%s'\n", hush_version_str);
6887 putenv((char *)hush_version_str);
6890 set_pwd_var(/*exp:*/ 1);
6891 /* bash also exports SHLVL and _,
6892 * and sets (but doesn't export) the following variables:
6894 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6895 * BASH_VERSION='3.2.0(1)-release'
6897 * MACHTYPE=i386-pc-linux-gnu
6899 * HOSTNAME=<xxxxxxxxxx>
6900 * PPID=<NNNNN> - we also do it elsewhere
6911 * PIPESTATUS=([0]="0")
6912 * HISTFILE=/<xxx>/.bash_history
6916 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
6918 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
6928 #if ENABLE_FEATURE_EDITING
6929 G.line_input_state = new_line_input_t(FOR_SHELL);
6931 G.global_argc = argc;
6932 G.global_argv = argv;
6933 /* Initialize some more globals to non-zero values */
6934 cmdedit_update_prompt();
6936 if (setjmp(die_jmp)) {
6937 /* xfunc has failed! die die die */
6938 /* no EXIT traps, this is an escape hatch! */
6940 hush_exit(xfunc_error_retval);
6943 /* Shell is non-interactive at first. We need to call
6944 * init_sigmasks() if we are going to execute "sh <script>",
6945 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6946 * If we later decide that we are interactive, we run init_sigmasks()
6947 * in order to intercept (more) signals.
6951 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6954 opt = getopt(argc, argv, "+c:xins"
6957 # if ENABLE_HUSH_FUNCTIONS
6967 * sh ... -c 'script'
6968 * sh ... -c 'script' ARG0 [ARG1...]
6969 * On NOMMU, if builtin_argc != 0,
6970 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
6971 * "" needs to be replaced with NULL
6972 * and BARGV vector fed to builtin function.
6973 * Note: the form without ARG0 never happens:
6974 * sh ... -c 'builtin' BARGV... ""
6977 G.root_pid = getpid();
6978 G.root_ppid = getppid();
6980 G.global_argv = argv + optind;
6981 G.global_argc = argc - optind;
6983 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6984 const struct built_in_command *x;
6987 x = find_builtin(optarg);
6988 if (x) { /* paranoia */
6989 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6990 G.global_argv += builtin_argc;
6991 G.global_argv[-1] = NULL; /* replace "" */
6992 G.last_exitcode = x->b_function(argv + optind - 1);
6996 if (!G.global_argv[0]) {
6997 /* -c 'script' (no params): prevent empty $0 */
6998 G.global_argv--; /* points to argv[i] of 'script' */
6999 G.global_argv[0] = argv[0];
7001 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7003 parse_and_run_string(optarg);
7006 /* Well, we cannot just declare interactiveness,
7007 * we have to have some stuff (ctty, etc) */
7008 /* G_interactive_fd++; */
7011 /* "-s" means "read from stdin", but this is how we always
7012 * operate, so simply do nothing here. */
7015 case '<': /* "big heredoc" support */
7016 full_write(STDOUT_FILENO, optarg, strlen(optarg));
7019 unsigned long long empty_trap_mask;
7021 G.root_pid = bb_strtou(optarg, &optarg, 16);
7023 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7025 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7027 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7029 builtin_argc = bb_strtou(optarg, &optarg, 16);
7031 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7032 if (empty_trap_mask != 0) {
7035 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7036 for (sig = 1; sig < NSIG; sig++) {
7037 if (empty_trap_mask & (1LL << sig)) {
7038 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7039 sigaddset(&G.blocked_set, sig);
7042 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7044 # if ENABLE_HUSH_LOOPS
7046 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7052 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7054 # if ENABLE_HUSH_FUNCTIONS
7056 struct function *funcp = new_function(optarg);
7057 /* funcp->name is already set to optarg */
7058 /* funcp->body is set to NULL. It's a special case. */
7059 funcp->body_as_string = argv[optind];
7067 if (!set_mode('-', opt))
7071 fprintf(stderr, "Usage: sh [FILE]...\n"
7072 " or: sh -c command [args]...\n\n");
7078 } /* option parsing loop */
7081 G.root_pid = getpid();
7082 G.root_ppid = getppid();
7085 /* If we are login shell... */
7086 if (argv[0] && argv[0][0] == '-') {
7088 debug_printf("sourcing /etc/profile\n");
7089 input = fopen_for_read("/etc/profile");
7090 if (input != NULL) {
7091 close_on_exec_on(fileno(input));
7093 parse_and_run_file(input);
7096 /* bash: after sourcing /etc/profile,
7097 * tries to source (in the given order):
7098 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7099 * stopping on first found. --noprofile turns this off.
7100 * bash also sources ~/.bash_logout on exit.
7101 * If called as sh, skips .bash_XXX files.
7108 * "bash <script>" (which is never interactive (unless -i?))
7109 * sources $BASH_ENV here (without scanning $PATH).
7110 * If called as sh, does the same but with $ENV.
7112 debug_printf("running script '%s'\n", argv[optind]);
7113 G.global_argv = argv + optind;
7114 G.global_argc = argc - optind;
7115 input = xfopen_for_read(argv[optind]);
7116 close_on_exec_on(fileno(input));
7118 parse_and_run_file(input);
7119 #if ENABLE_FEATURE_CLEAN_UP
7125 /* Up to here, shell was non-interactive. Now it may become one.
7126 * NB: don't forget to (re)run init_sigmasks() as needed.
7129 /* A shell is interactive if the '-i' flag was given,
7130 * or if all of the following conditions are met:
7132 * no arguments remaining or the -s flag given
7133 * standard input is a terminal
7134 * standard output is a terminal
7135 * Refer to Posix.2, the description of the 'sh' utility.
7138 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7139 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7140 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7141 if (G_saved_tty_pgrp < 0)
7142 G_saved_tty_pgrp = 0;
7144 /* try to dup stdin to high fd#, >= 255 */
7145 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7146 if (G_interactive_fd < 0) {
7147 /* try to dup to any fd */
7148 G_interactive_fd = dup(STDIN_FILENO);
7149 if (G_interactive_fd < 0) {
7151 G_interactive_fd = 0;
7152 G_saved_tty_pgrp = 0;
7155 // TODO: track & disallow any attempts of user
7156 // to (inadvertently) close/redirect G_interactive_fd
7158 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7159 if (G_interactive_fd) {
7160 close_on_exec_on(G_interactive_fd);
7162 if (G_saved_tty_pgrp) {
7163 /* If we were run as 'hush &', sleep until we are
7164 * in the foreground (tty pgrp == our pgrp).
7165 * If we get started under a job aware app (like bash),
7166 * make sure we are now in charge so we don't fight over
7167 * who gets the foreground */
7169 pid_t shell_pgrp = getpgrp();
7170 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7171 if (G_saved_tty_pgrp == shell_pgrp)
7173 /* send TTIN to ourself (should stop us) */
7174 kill(- shell_pgrp, SIGTTIN);
7178 /* Block some signals */
7181 if (G_saved_tty_pgrp) {
7182 /* Set other signals to restore saved_tty_pgrp */
7183 set_fatal_handlers();
7184 /* Put ourselves in our own process group
7185 * (bash, too, does this only if ctty is available) */
7186 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7187 /* Grab control of the terminal */
7188 tcsetpgrp(G_interactive_fd, getpid());
7190 /* -1 is special - makes xfuncs longjmp, not exit
7191 * (we reset die_sleep = 0 whereever we [v]fork) */
7192 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7196 #elif ENABLE_HUSH_INTERACTIVE
7197 /* No job control compiled in, only prompt/line editing */
7198 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7199 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7200 if (G_interactive_fd < 0) {
7201 /* try to dup to any fd */
7202 G_interactive_fd = dup(STDIN_FILENO);
7203 if (G_interactive_fd < 0)
7205 G_interactive_fd = 0;
7208 if (G_interactive_fd) {
7209 close_on_exec_on(G_interactive_fd);
7213 /* We have interactiveness code disabled */
7217 * if interactive but not a login shell, sources ~/.bashrc
7218 * (--norc turns this off, --rcfile <file> overrides)
7221 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7222 /* note: ash and hush share this string */
7223 printf("\n\n%s %s\n"
7224 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7227 "hush - the humble shell"
7231 parse_and_run_file(stdin);
7234 #if ENABLE_FEATURE_CLEAN_UP
7235 if (G.cwd != bb_msg_unknown)
7237 cur_var = G.top_var->next;
7239 struct variable *tmp = cur_var;
7240 if (!cur_var->max_len)
7241 free(cur_var->varstr);
7242 cur_var = cur_var->next;
7246 hush_exit(G.last_exitcode);
7251 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7252 int lash_main(int argc, char **argv)
7254 bb_error_msg("lash is deprecated, please use hush instead");
7255 return hush_main(argc, argv);
7260 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7261 int msh_main(int argc, char **argv)
7263 //bb_error_msg("msh is deprecated, please use hush instead");
7264 return hush_main(argc, argv);
7272 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7277 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7284 return applet_main_func(argc, argv - argc);
7287 static int FAST_FUNC builtin_test(char **argv)
7289 return run_applet_main(argv, test_main);
7292 static int FAST_FUNC builtin_echo(char **argv)
7294 return run_applet_main(argv, echo_main);
7298 static int FAST_FUNC builtin_printf(char **argv)
7300 return run_applet_main(argv, printf_main);
7304 static char **skip_dash_dash(char **argv)
7307 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7312 static int FAST_FUNC builtin_eval(char **argv)
7314 int rcode = EXIT_SUCCESS;
7316 argv = skip_dash_dash(argv);
7318 char *str = expand_strvec_to_string(argv);
7320 * eval "echo Hi; done" ("done" is syntax error):
7321 * "echo Hi" will not execute too.
7323 parse_and_run_string(str);
7325 rcode = G.last_exitcode;
7330 static int FAST_FUNC builtin_cd(char **argv)
7334 argv = skip_dash_dash(argv);
7336 if (newdir == NULL) {
7337 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7338 * bash says "bash: cd: HOME not set" and does nothing
7341 const char *home = get_local_var_value("HOME");
7342 newdir = home ? home : "/";
7344 if (chdir(newdir)) {
7345 /* Mimic bash message exactly */
7346 bb_perror_msg("cd: %s", newdir);
7347 return EXIT_FAILURE;
7349 /* Read current dir (get_cwd(1) is inside) and set PWD.
7350 * Note: do not enforce exporting. If PWD was unset or unexported,
7351 * set it again, but do not export. bash does the same.
7353 set_pwd_var(/*exp:*/ 0);
7354 return EXIT_SUCCESS;
7357 static int FAST_FUNC builtin_exec(char **argv)
7359 argv = skip_dash_dash(argv);
7360 if (argv[0] == NULL)
7361 return EXIT_SUCCESS; /* bash does this */
7363 /* Careful: we can end up here after [v]fork. Do not restore
7364 * tty pgrp then, only top-level shell process does that */
7365 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7366 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7368 /* TODO: if exec fails, bash does NOT exit! We do.
7369 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7370 * and tcsetpgrp, and this is inherently racy.
7372 execvp_or_die(argv);
7375 static int FAST_FUNC builtin_exit(char **argv)
7377 debug_printf_exec("%s()\n", __func__);
7379 /* interactive bash:
7380 * # trap "echo EEE" EXIT
7383 * There are stopped jobs.
7384 * (if there are _stopped_ jobs, running ones don't count)
7387 # EEE (then bash exits)
7389 * we can use G.exiting = -1 as indicator "last cmd was exit"
7392 /* note: EXIT trap is run by hush_exit */
7393 argv = skip_dash_dash(argv);
7394 if (argv[0] == NULL)
7395 hush_exit(G.last_exitcode);
7396 /* mimic bash: exit 123abc == exit 255 + error msg */
7397 xfunc_error_retval = 255;
7398 /* bash: exit -2 == exit 254, no error msg */
7399 hush_exit(xatoi(argv[0]) & 0xff);
7402 static void print_escaped(const char *s)
7407 const char *p = strchrnul(s, '\'');
7408 /* print 'xxxx', possibly just '' */
7409 printf("'%.*s'", (int)(p - s), s);
7414 /* s points to '; print "'''...'''" */
7416 do putchar('\''); while (*++s == '\'');
7421 #if !ENABLE_HUSH_LOCAL
7422 #define helper_export_local(argv, exp, lvl) \
7423 helper_export_local(argv, exp)
7425 static void helper_export_local(char **argv, int exp, int lvl)
7430 /* So far we do not check that name is valid (TODO?) */
7432 if (strchr(name, '=') == NULL) {
7433 struct variable *var;
7435 var = get_local_var(name);
7436 if (exp == -1) { /* unexporting? */
7437 /* export -n NAME (without =VALUE) */
7439 var->flg_export = 0;
7440 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7442 } /* else: export -n NOT_EXISTING_VAR: no-op */
7445 if (exp == 1) { /* exporting? */
7446 /* export NAME (without =VALUE) */
7448 var->flg_export = 1;
7449 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7450 putenv(var->varstr);
7454 /* Exporting non-existing variable.
7455 * bash does not put it in environment,
7456 * but remembers that it is exported,
7457 * and does put it in env when it is set later.
7458 * We just set it to "" and export. */
7459 /* Or, it's "local NAME" (without =VALUE).
7460 * bash sets the value to "". */
7461 name = xasprintf("%s=", name);
7463 /* (Un)exporting/making local NAME=VALUE */
7464 name = xstrdup(name);
7466 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7470 static int FAST_FUNC builtin_export(char **argv)
7472 unsigned opt_unexport;
7474 #if ENABLE_HUSH_EXPORT_N
7475 /* "!": do not abort on errors */
7476 opt_unexport = getopt32(argv, "!n");
7477 if (opt_unexport == (uint32_t)-1)
7478 return EXIT_FAILURE;
7485 if (argv[0] == NULL) {
7492 /* ash emits: export VAR='VAL'
7493 * bash: declare -x VAR="VAL"
7494 * we follow ash example */
7495 const char *s = *e++;
7496 const char *p = strchr(s, '=');
7498 if (!p) /* wtf? take next variable */
7501 printf("export %.*s", (int)(p - s) + 1, s);
7502 print_escaped(p + 1);
7506 /*fflush_all(); - done after each builtin anyway */
7508 return EXIT_SUCCESS;
7511 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7513 return EXIT_SUCCESS;
7516 #if ENABLE_HUSH_LOCAL
7517 static int FAST_FUNC builtin_local(char **argv)
7519 if (G.func_nest_level == 0) {
7520 bb_error_msg("%s: not in a function", argv[0]);
7521 return EXIT_FAILURE; /* bash compat */
7523 helper_export_local(argv, 0, G.func_nest_level);
7524 return EXIT_SUCCESS;
7528 static int FAST_FUNC builtin_trap(char **argv)
7534 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7539 /* No args: print all trapped */
7540 for (i = 0; i < NSIG; ++i) {
7543 print_escaped(G.traps[i]);
7544 /* note: bash adds "SIG", but only if invoked
7545 * as "bash". If called as "sh", or if set -o posix,
7546 * then it prints short signal names.
7547 * We are printing short names: */
7548 printf(" %s\n", get_signame(i));
7551 /*fflush_all(); - done after each builtin anyway */
7552 return EXIT_SUCCESS;
7556 /* If first arg is a number: reset all specified signals */
7557 sig = bb_strtou(*argv, NULL, 10);
7563 sig = get_signum(*argv++);
7564 if (sig < 0 || sig >= NSIG) {
7566 /* Mimic bash message exactly */
7567 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7572 G.traps[sig] = xstrdup(new_cmd);
7574 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7575 get_signame(sig), sig, G.traps[sig]);
7577 /* There is no signal for 0 (EXIT) */
7582 sigaddset(&G.blocked_set, sig);
7584 /* There was a trap handler, we are removing it
7585 * (if sig has non-DFL handling,
7586 * we don't need to do anything) */
7587 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7589 sigdelset(&G.blocked_set, sig);
7592 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7596 if (!argv[1]) { /* no second arg */
7597 bb_error_msg("trap: invalid arguments");
7598 return EXIT_FAILURE;
7601 /* First arg is "-": reset all specified to default */
7602 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7603 /* Everything else: set arg as signal handler
7604 * (includes "" case, which ignores signal) */
7605 if (argv[0][0] == '-') {
7606 if (argv[0][1] == '\0') { /* "-" */
7607 /* new_cmd remains NULL: "reset these sigs" */
7610 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7613 /* else: "-something", no special meaning */
7618 goto process_sig_list;
7621 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7622 static int FAST_FUNC builtin_type(char **argv)
7624 int ret = EXIT_SUCCESS;
7630 if (0) {} /* make conditional compile easier below */
7631 /*else if (find_alias(*argv))
7632 type = "an alias";*/
7633 #if ENABLE_HUSH_FUNCTIONS
7634 else if (find_function(*argv))
7635 type = "a function";
7637 else if (find_builtin(*argv))
7638 type = "a shell builtin";
7639 else if ((path = find_in_path(*argv)) != NULL)
7642 bb_error_msg("type: %s: not found", *argv);
7647 printf("%s is %s\n", *argv, type);
7655 /* built-in 'fg' and 'bg' handler */
7656 static int FAST_FUNC builtin_fg_bg(char **argv)
7661 if (!G_interactive_fd)
7662 return EXIT_FAILURE;
7664 /* If they gave us no args, assume they want the last backgrounded task */
7666 for (pi = G.job_list; pi; pi = pi->next) {
7667 if (pi->jobid == G.last_jobid) {
7671 bb_error_msg("%s: no current job", argv[0]);
7672 return EXIT_FAILURE;
7674 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7675 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7676 return EXIT_FAILURE;
7678 for (pi = G.job_list; pi; pi = pi->next) {
7679 if (pi->jobid == jobnum) {
7683 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7684 return EXIT_FAILURE;
7686 /* TODO: bash prints a string representation
7687 * of job being foregrounded (like "sleep 1 | cat") */
7688 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7689 /* Put the job into the foreground. */
7690 tcsetpgrp(G_interactive_fd, pi->pgrp);
7693 /* Restart the processes in the job */
7694 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7695 for (i = 0; i < pi->num_cmds; i++) {
7696 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7697 pi->cmds[i].is_stopped = 0;
7699 pi->stopped_cmds = 0;
7701 i = kill(- pi->pgrp, SIGCONT);
7703 if (errno == ESRCH) {
7704 delete_finished_bg_job(pi);
7705 return EXIT_SUCCESS;
7707 bb_perror_msg("kill (SIGCONT)");
7710 if (argv[0][0] == 'f') {
7712 return checkjobs_and_fg_shell(pi);
7714 return EXIT_SUCCESS;
7718 #if ENABLE_HUSH_HELP
7719 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7721 const struct built_in_command *x;
7724 "Built-in commands:\n"
7725 "------------------\n");
7726 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7728 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7731 return EXIT_SUCCESS;
7736 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7739 const char *status_string;
7741 for (job = G.job_list; job; job = job->next) {
7742 if (job->alive_cmds == job->stopped_cmds)
7743 status_string = "Stopped";
7745 status_string = "Running";
7747 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7749 return EXIT_SUCCESS;
7754 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7759 # ifdef M_TRIM_THRESHOLD
7760 /* Optional. Reduces probability of false positives */
7763 /* Crude attempt to find where "free memory" starts,
7764 * sans fragmentation. */
7766 l = (unsigned long)p;
7769 if (l < (unsigned long)p) l = (unsigned long)p;
7772 if (!G.memleak_value)
7773 G.memleak_value = l;
7775 l -= G.memleak_value;
7782 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7787 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7790 return EXIT_SUCCESS;
7793 static int FAST_FUNC builtin_read(char **argv)
7802 /* "!": do not abort on errors.
7803 * Option string must start with "sr" to match BUILTIN_READ_xxx
7805 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7806 if (read_flags == (uint32_t)-1)
7807 return EXIT_FAILURE;
7810 r = shell_builtin_read(set_local_var_from_halves,
7812 get_local_var_value("IFS"), /* can be NULL */
7820 if ((uintptr_t)r > 1) {
7821 bb_error_msg("%s", r);
7822 r = (char*)(uintptr_t)1;
7825 return (uintptr_t)r;
7828 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7829 * built-in 'set' handler
7831 * set [-abCefhmnuvx] [-o option] [argument...]
7832 * set [+abCefhmnuvx] [+o option] [argument...]
7833 * set -- [argument...]
7836 * Implementations shall support the options in both their hyphen and
7837 * plus-sign forms. These options can also be specified as options to sh.
7839 * Write out all variables and their values: set
7840 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7841 * Turn on the -x and -v options: set -xv
7842 * Unset all positional parameters: set --
7843 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7844 * Set the positional parameters to the expansion of x, even if x expands
7845 * with a leading '-' or '+': set -- $x
7847 * So far, we only support "set -- [argument...]" and some of the short names.
7849 static int FAST_FUNC builtin_set(char **argv)
7852 char **pp, **g_argv;
7853 char *arg = *++argv;
7857 for (e = G.top_var; e; e = e->next)
7859 return EXIT_SUCCESS;
7863 if (!strcmp(arg, "--")) {
7867 if (arg[0] != '+' && arg[0] != '-')
7869 for (n = 1; arg[n]; ++n)
7870 if (set_mode(arg[0], arg[n]))
7872 } while ((arg = *++argv) != NULL);
7873 /* Now argv[0] is 1st argument */
7876 return EXIT_SUCCESS;
7879 /* NB: G.global_argv[0] ($0) is never freed/changed */
7880 g_argv = G.global_argv;
7881 if (G.global_args_malloced) {
7887 G.global_args_malloced = 1;
7888 pp = xzalloc(sizeof(pp[0]) * 2);
7889 pp[0] = g_argv[0]; /* retain $0 */
7892 /* This realloc's G.global_argv */
7893 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7900 return EXIT_SUCCESS;
7902 /* Nothing known, so abort */
7904 bb_error_msg("set: %s: invalid option", arg);
7905 return EXIT_FAILURE;
7908 static int FAST_FUNC builtin_shift(char **argv)
7911 argv = skip_dash_dash(argv);
7915 if (n >= 0 && n < G.global_argc) {
7916 if (G.global_args_malloced) {
7919 free(G.global_argv[m++]);
7922 memmove(&G.global_argv[1], &G.global_argv[n+1],
7923 G.global_argc * sizeof(G.global_argv[0]));
7924 return EXIT_SUCCESS;
7926 return EXIT_FAILURE;
7929 static int FAST_FUNC builtin_source(char **argv)
7931 char *arg_path, *filename;
7934 #if ENABLE_HUSH_FUNCTIONS
7938 argv = skip_dash_dash(argv);
7941 /* bash says: "bash: .: filename argument required" */
7942 return 2; /* bash compat */
7945 if (!strchr(filename, '/')) {
7946 arg_path = find_in_path(filename);
7948 filename = arg_path;
7950 input = fopen_or_warn(filename, "r");
7953 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7954 return EXIT_FAILURE;
7956 close_on_exec_on(fileno(input));
7958 #if ENABLE_HUSH_FUNCTIONS
7959 sv_flg = G.flag_return_in_progress;
7960 /* "we are inside sourced file, ok to use return" */
7961 G.flag_return_in_progress = -1;
7963 save_and_replace_G_args(&sv, argv);
7965 parse_and_run_file(input);
7968 restore_G_args(&sv, argv);
7969 #if ENABLE_HUSH_FUNCTIONS
7970 G.flag_return_in_progress = sv_flg;
7973 return G.last_exitcode;
7976 static int FAST_FUNC builtin_umask(char **argv)
7982 argv = skip_dash_dash(argv);
7984 mode_t old_mask = mask;
7987 rc = bb_parse_mode(argv[0], &mask);
7992 * bash: umask: 'q': invalid symbolic mode operator
7993 * bash: umask: 999: octal number out of range
7995 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8000 printf("%04o\n", (unsigned) mask);
8001 /* fall through and restore mask which we set to 0 */
8005 return !rc; /* rc != 0 - success */
8008 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8009 static int FAST_FUNC builtin_unset(char **argv)
8014 /* "!": do not abort on errors */
8015 /* "+": stop at 1st non-option */
8016 opts = getopt32(argv, "!+vf");
8017 if (opts == (unsigned)-1)
8018 return EXIT_FAILURE;
8020 bb_error_msg("unset: -v and -f are exclusive");
8021 return EXIT_FAILURE;
8027 if (!(opts & 2)) { /* not -f */
8028 if (unset_local_var(*argv)) {
8029 /* unset <nonexistent_var> doesn't fail.
8030 * Error is when one tries to unset RO var.
8031 * Message was printed by unset_local_var. */
8035 #if ENABLE_HUSH_FUNCTIONS
8045 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8046 static int FAST_FUNC builtin_wait(char **argv)
8048 int ret = EXIT_SUCCESS;
8051 argv = skip_dash_dash(argv);
8052 if (argv[0] == NULL) {
8053 /* Don't care about wait results */
8054 /* Note 1: must wait until there are no more children */
8055 /* Note 2: must be interruptible */
8057 * $ sleep 3 & sleep 6 & wait
8062 * $ sleep 3 & sleep 6 & wait
8066 * ^C <-- after ~4 sec from keyboard
8069 sigaddset(&G.blocked_set, SIGCHLD);
8070 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8073 if (errno == ECHILD)
8075 /* Wait for SIGCHLD or any other signal of interest */
8076 /* sigtimedwait with infinite timeout: */
8077 sig = sigwaitinfo(&G.blocked_set, NULL);
8079 sig = check_and_run_traps(sig);
8080 if (sig && sig != SIGCHLD) { /* see note 2 */
8086 sigdelset(&G.blocked_set, SIGCHLD);
8087 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8091 /* This is probably buggy wrt interruptible-ness */
8093 pid_t pid = bb_strtou(*argv, NULL, 10);
8095 /* mimic bash message */
8096 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8097 return EXIT_FAILURE;
8099 if (waitpid(pid, &status, 0) == pid) {
8100 if (WIFSIGNALED(status))
8101 ret = 128 + WTERMSIG(status);
8102 else if (WIFEXITED(status))
8103 ret = WEXITSTATUS(status);
8107 bb_perror_msg("wait %s", *argv);
8116 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8117 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8120 def = bb_strtou(argv[1], NULL, 10);
8121 if (errno || def < def_min || argv[2]) {
8122 bb_error_msg("%s: bad arguments", argv[0]);
8130 #if ENABLE_HUSH_LOOPS
8131 static int FAST_FUNC builtin_break(char **argv)
8134 if (G.depth_of_loop == 0) {
8135 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8136 return EXIT_SUCCESS; /* bash compat */
8138 G.flag_break_continue++; /* BC_BREAK = 1 */
8140 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8141 if (depth == UINT_MAX)
8142 G.flag_break_continue = BC_BREAK;
8143 if (G.depth_of_loop < depth)
8144 G.depth_break_continue = G.depth_of_loop;
8146 return EXIT_SUCCESS;
8149 static int FAST_FUNC builtin_continue(char **argv)
8151 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8152 return builtin_break(argv);
8156 #if ENABLE_HUSH_FUNCTIONS
8157 static int FAST_FUNC builtin_return(char **argv)
8161 if (G.flag_return_in_progress != -1) {
8162 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8163 return EXIT_FAILURE; /* bash compat */
8166 G.flag_return_in_progress = 1;
8169 * out of range: wraps around at 256, does not error out
8170 * non-numeric param:
8171 * f() { false; return qwe; }; f; echo $?
8172 * bash: return: qwe: numeric argument required <== we do this
8173 * 255 <== we also do this
8175 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);