1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
41 * grep for "TODO" and fix (some of them are easy)
42 * special variables (done: PWD, PPID, RANDOM)
45 * follow IFS rules more precisely, including update semantics
46 * builtins mandated by standards we don't support:
47 * [un]alias, command, fc, getopts, newgrp, readonly, times
48 * make complex ${var%...} constructs support optional
49 * make here documents optional
52 * redirection of stdout+stderr: &> and >&
53 * brace expansion: one/{two,three,four}
54 * reserved words: function select
55 * advanced test: [[ ]]
56 * process substitution: <(list) and >(list)
59 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
60 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
61 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
63 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
64 * This is exactly equivalent to let "EXPR".
65 * $[EXPR]: synonym for $((EXPR))
66 * export builtin should be special, its arguments are assignments
67 * and therefore expansion of them should be "one-word" expansion:
68 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
70 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
71 * ls: cannot access i=a: No such file or directory
72 * ls: cannot access b: No such file or directory
73 * Note1: same applies to local builtin.
74 * Note2: bash 3.2.33(1) does this only if export word itself
76 * $ export i=`echo 'aaa bbb'`; echo "$i"
78 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
81 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
83 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
84 #include <malloc.h> /* for malloc_trim */
86 /* #include <dmalloc.h> */
91 #include "shell_common.h"
92 #include "builtin_read.h"
93 #include "builtin_ulimit.h"
96 #if ENABLE_HUSH_RANDOM_SUPPORT
99 # define CLEAR_RANDOM_T(rnd) ((void)0)
102 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
107 #define LEAK_HUNTING 0
108 #define BUILD_AS_NOMMU 0
109 /* Enable/disable sanity checks. Ok to enable in production,
110 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
111 * Keeping 1 for now even in released versions.
114 /* Slightly bigger (+200 bytes), but faster hush.
115 * So far it only enables a trick with counting SIGCHLDs and forks,
116 * which allows us to do fewer waitpid's.
117 * (we can detect a case where neither forks were done nor SIGCHLDs happened
118 * and therefore waitpid will return the same result as last time)
120 #define ENABLE_HUSH_FAST 0
125 # undef USE_FOR_NOMMU
128 # define USE_FOR_NOMMU(...) __VA_ARGS__
129 # define USE_FOR_MMU(...)
132 #define SKIP_definitions 1
133 #include "applet_tables.h"
134 #undef SKIP_definitions
136 /* STANDALONE does not make sense, and won't compile */
137 # undef CONFIG_FEATURE_SH_STANDALONE
138 # undef ENABLE_FEATURE_SH_STANDALONE
139 # undef IF_FEATURE_SH_STANDALONE
140 # undef IF_NOT_FEATURE_SH_STANDALONE
141 # define ENABLE_FEATURE_SH_STANDALONE 0
142 # define IF_FEATURE_SH_STANDALONE(...)
143 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
146 #if !ENABLE_HUSH_INTERACTIVE
147 # undef ENABLE_FEATURE_EDITING
148 # define ENABLE_FEATURE_EDITING 0
149 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
150 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
153 /* Do we support ANY keywords? */
154 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
155 # define HAS_KEYWORDS 1
156 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
157 # define IF_HAS_NO_KEYWORDS(...)
159 # define HAS_KEYWORDS 0
160 # define IF_HAS_KEYWORDS(...)
161 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
164 /* If you comment out one of these below, it will be #defined later
165 * to perform debug printfs to stderr: */
166 #define debug_printf(...) do {} while (0)
167 /* Finer-grained debug switches */
168 #define debug_printf_parse(...) do {} while (0)
169 #define debug_print_tree(a, b) do {} while (0)
170 #define debug_printf_exec(...) do {} while (0)
171 #define debug_printf_env(...) do {} while (0)
172 #define debug_printf_jobs(...) do {} while (0)
173 #define debug_printf_expand(...) do {} while (0)
174 #define debug_printf_varexp(...) do {} while (0)
175 #define debug_printf_glob(...) do {} while (0)
176 #define debug_printf_list(...) do {} while (0)
177 #define debug_printf_subst(...) do {} while (0)
178 #define debug_printf_clean(...) do {} while (0)
180 #define ERR_PTR ((void*)(long)1)
182 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
184 #define _SPECIAL_VARS_STR "_*@$!?#"
185 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
186 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
188 #define SPECIAL_VAR_SYMBOL 3
192 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
194 /* This supports saving pointers malloced in vfork child,
195 * to be freed in the parent.
198 typedef struct nommu_save_t {
200 struct variable *old_vars;
202 char **argv_from_re_execing;
206 typedef enum reserved_style {
215 #if ENABLE_HUSH_LOOPS
222 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
227 /* three pseudo-keywords support contrived "case" syntax: */
228 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
229 RES_MATCH , /* "word)" */
230 RES_CASE_BODY, /* "this command is inside CASE" */
237 typedef struct o_string {
239 int length; /* position where data is appended */
241 /* Protect newly added chars against globbing
242 * (by prepending \ to *, ?, [, \) */
245 /* At least some part of the string was inside '' or "",
246 * possibly empty one: word"", wo''rd etc. */
248 smallint has_empty_slot;
249 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
252 MAYBE_ASSIGNMENT = 0,
253 DEFINITELY_ASSIGNMENT = 1,
255 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
257 /* Used for initialization: o_string foo = NULL_O_STRING; */
258 #define NULL_O_STRING { NULL }
260 /* I can almost use ordinary FILE*. Is open_memstream() universally
261 * available? Where is it documented? */
262 typedef struct in_str {
264 /* eof_flag=1: last char in ->p is really an EOF */
265 char eof_flag; /* meaningless if ->p == NULL */
267 #if ENABLE_HUSH_INTERACTIVE
269 smallint promptmode; /* 0: PS1, 1: PS2 */
272 int (*get) (struct in_str *) FAST_FUNC;
273 int (*peek) (struct in_str *) FAST_FUNC;
275 #define i_getch(input) ((input)->get(input))
276 #define i_peek(input) ((input)->peek(input))
278 /* The descrip member of this structure is only used to make
279 * debugging output pretty */
280 static const struct {
282 signed char default_fd;
285 { O_RDONLY, 0, "<" },
286 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
287 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
288 { O_CREAT|O_RDWR, 1, "<>" },
289 { O_RDONLY, 0, "<<" },
290 /* Should not be needed. Bogus default_fd helps in debugging */
291 /* { O_RDONLY, 77, "<<" }, */
294 struct redir_struct {
295 struct redir_struct *next;
296 char *rd_filename; /* filename */
297 int rd_fd; /* fd to redirect */
298 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
300 smallint rd_type; /* (enum redir_type) */
301 /* note: for heredocs, rd_filename contains heredoc delimiter,
302 * and subsequently heredoc itself; and rd_dup is a bitmask:
303 * bit 0: do we need to trim leading tabs?
304 * bit 1: is heredoc quoted (<<'delim' syntax) ?
307 typedef enum redir_type {
309 REDIRECT_OVERWRITE = 1,
312 REDIRECT_HEREDOC = 4,
313 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
316 REDIRFD_SYNTAX_ERR = -2,
317 REDIRFD_TO_FILE = -1,
318 /* otherwise, rd_fd is redirected to rd_dup */
320 HEREDOC_SKIPTABS = 1,
326 pid_t pid; /* 0 if exited */
327 int assignment_cnt; /* how many argv[i] are assignments? */
328 smallint is_stopped; /* is the command currently running? */
329 smallint cmd_type; /* CMD_xxx */
331 #define CMD_SUBSHELL 1
333 /* used for "[[ EXPR ]]" */
334 #if ENABLE_HUSH_BASH_COMPAT
335 # define CMD_SINGLEWORD_NOGLOB 2
338 /* used for "export noglob=* glob* a=`echo a b`" */
339 //#define CMD_SINGLEWORD_NOGLOB_COND 3
340 // It is hard to implement correctly, it adds significant amounts of tricky code,
341 // and all this is only useful for really obscure export statements
342 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
343 // guards the code which implements it, but I have doubts it works
344 // in all cases (especially with mixed globbed/non-globbed arguments)
346 #if ENABLE_HUSH_FUNCTIONS
347 # define CMD_FUNCDEF 3
350 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
353 char *group_as_string;
355 #if ENABLE_HUSH_FUNCTIONS
356 struct function *child_func;
357 /* This field is used to prevent a bug here:
358 * while...do f1() {a;}; f1; f1() {b;}; f1; done
359 * When we execute "f1() {a;}" cmd, we create new function and clear
360 * cmd->group, cmd->group_as_string, cmd->argv[0].
361 * When we execute "f1() {b;}", we notice that f1 exists,
362 * and that its "parent cmd" struct is still "alive",
363 * we put those fields back into cmd->xxx
364 * (struct function has ->parent_cmd ptr to facilitate that).
365 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
366 * Without this trick, loop would execute a;b;b;b;...
367 * instead of correct sequence a;b;a;b;...
368 * When command is freed, it severs the link
369 * (sets ->child_func->parent_cmd to NULL).
372 char **argv; /* command name and arguments */
373 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
374 * and on execution these are substituted with their values.
375 * Substitution can make _several_ words out of one argv[n]!
376 * Example: argv[0]=='.^C*^C.' here: echo .$*.
377 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
379 struct redir_struct *redirects; /* I/O redirections */
381 /* Is there anything in this command at all? */
382 #define IS_NULL_CMD(cmd) \
383 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
388 int num_cmds; /* total number of commands in pipe */
389 int alive_cmds; /* number of commands running (not exited) */
390 int stopped_cmds; /* number of commands alive, but stopped */
392 int jobid; /* job number */
393 pid_t pgrp; /* process group ID for the job */
394 char *cmdtext; /* name of job */
396 struct command *cmds; /* array of commands in pipe */
397 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
398 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
399 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
401 typedef enum pipe_style {
407 /* Is there anything in this pipe at all? */
408 #define IS_NULL_PIPE(pi) \
409 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
411 /* This holds pointers to the various results of parsing */
412 struct parse_context {
413 /* linked list of pipes */
414 struct pipe *list_head;
415 /* last pipe (being constructed right now) */
417 /* last command in pipe (being constructed right now) */
418 struct command *command;
419 /* last redirect in command->redirects list */
420 struct redir_struct *pending_redirect;
426 smallint ctx_inverted; /* "! cmd | cmd" */
428 smallint ctx_dsemicolon; /* ";;" seen */
430 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
432 /* group we are enclosed in:
433 * example: "if pipe1; pipe2; then pipe3; fi"
434 * when we see "if" or "then", we malloc and copy current context,
435 * and make ->stack point to it. then we parse pipeN.
436 * when closing "then" / fi" / whatever is found,
437 * we move list_head into ->stack->command->group,
438 * copy ->stack into current context, and delete ->stack.
439 * (parsing of { list } and ( list ) doesn't use this method)
441 struct parse_context *stack;
445 /* On program start, environ points to initial environment.
446 * putenv adds new pointers into it, unsetenv removes them.
447 * Neither of these (de)allocates the strings.
448 * setenv allocates new strings in malloc space and does putenv,
449 * and thus setenv is unusable (leaky) for shell's purposes */
450 #define setenv(...) setenv_is_leaky_dont_use()
452 struct variable *next;
453 char *varstr; /* points to "name=" portion */
454 #if ENABLE_HUSH_LOCAL
455 unsigned func_nest_level;
457 int max_len; /* if > 0, name is part of initial env; else name is malloced */
458 smallint flg_export; /* putenv should be done on this var */
459 smallint flg_read_only;
467 #if ENABLE_HUSH_FUNCTIONS
469 struct function *next;
471 struct command *parent_cmd;
474 char *body_as_string;
480 /* "Globals" within this file */
481 /* Sorted roughly by size (smaller offsets == smaller code) */
483 /* interactive_fd != 0 means we are an interactive shell.
484 * If we are, then saved_tty_pgrp can also be != 0, meaning
485 * that controlling tty is available. With saved_tty_pgrp == 0,
486 * job control still works, but terminal signals
487 * (^C, ^Z, ^Y, ^\) won't work at all, and background
488 * process groups can only be created with "cmd &".
489 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
490 * to give tty to the foreground process group,
491 * and will take it back when the group is stopped (^Z)
494 #if ENABLE_HUSH_INTERACTIVE
495 /* 'interactive_fd' is a fd# open to ctty, if we have one
496 * _AND_ if we decided to act interactively */
500 # define G_interactive_fd (G.interactive_fd)
502 # define G_interactive_fd 0
504 #if ENABLE_FEATURE_EDITING
505 line_input_t *line_input_state;
510 #if ENABLE_HUSH_RANDOM_SUPPORT
516 pid_t saved_tty_pgrp;
517 struct pipe *job_list;
518 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
520 # define G_saved_tty_pgrp 0
522 smallint flag_SIGINT;
523 #if ENABLE_HUSH_LOOPS
524 smallint flag_break_continue;
526 #if ENABLE_HUSH_FUNCTIONS
527 /* 0: outside of a function (or sourced file)
528 * -1: inside of a function, ok to use return builtin
529 * 1: return is invoked, skip all till end of func
531 smallint flag_return_in_progress;
534 smallint exiting; /* used to prevent EXIT trap recursion */
535 /* These four support $?, $#, and $1 */
536 smalluint last_exitcode;
537 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
538 smalluint global_args_malloced;
539 smalluint inherited_set_is_saved;
540 /* how many non-NULL argv's we have. NB: $# + 1 */
544 char *argv0_for_re_execing;
546 #if ENABLE_HUSH_LOOPS
547 unsigned depth_break_continue;
548 unsigned depth_of_loop;
552 struct variable *top_var; /* = &G.shell_ver (set in main()) */
553 struct variable shell_ver;
554 #if ENABLE_HUSH_FUNCTIONS
555 struct function *top_func;
556 # if ENABLE_HUSH_LOCAL
557 struct variable **shadowed_vars_pp;
558 unsigned func_nest_level;
561 /* Signal and trap handling */
563 unsigned count_SIGCHLD;
564 unsigned handled_SIGCHLD;
565 smallint we_have_children;
567 /* which signals have non-DFL handler (even with no traps set)? */
568 unsigned non_DFL_mask;
569 char **traps; /* char *traps[NSIG] */
570 sigset_t blocked_set;
571 sigset_t inherited_set;
573 unsigned long memleak_value;
576 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
578 #define G (*ptr_to_globals)
579 /* Not #defining name to G.name - this quickly gets unwieldy
580 * (too many defines). Also, I actually prefer to see when a variable
581 * is global, thus "G." prefix is a useful hint */
582 #define INIT_G() do { \
583 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
587 /* Function prototypes for builtins */
588 static int builtin_cd(char **argv) FAST_FUNC;
589 static int builtin_echo(char **argv) FAST_FUNC;
590 static int builtin_eval(char **argv) FAST_FUNC;
591 static int builtin_exec(char **argv) FAST_FUNC;
592 static int builtin_exit(char **argv) FAST_FUNC;
593 static int builtin_export(char **argv) FAST_FUNC;
595 static int builtin_fg_bg(char **argv) FAST_FUNC;
596 static int builtin_jobs(char **argv) FAST_FUNC;
599 static int builtin_help(char **argv) FAST_FUNC;
601 #if ENABLE_HUSH_LOCAL
602 static int builtin_local(char **argv) FAST_FUNC;
605 static int builtin_memleak(char **argv) FAST_FUNC;
608 static int builtin_printf(char **argv) FAST_FUNC;
610 static int builtin_pwd(char **argv) FAST_FUNC;
611 static int builtin_read(char **argv) FAST_FUNC;
612 static int builtin_set(char **argv) FAST_FUNC;
613 static int builtin_shift(char **argv) FAST_FUNC;
614 static int builtin_source(char **argv) FAST_FUNC;
615 static int builtin_test(char **argv) FAST_FUNC;
616 static int builtin_trap(char **argv) FAST_FUNC;
617 static int builtin_type(char **argv) FAST_FUNC;
618 static int builtin_true(char **argv) FAST_FUNC;
619 static int builtin_umask(char **argv) FAST_FUNC;
620 static int builtin_unset(char **argv) FAST_FUNC;
621 static int builtin_wait(char **argv) FAST_FUNC;
622 #if ENABLE_HUSH_LOOPS
623 static int builtin_break(char **argv) FAST_FUNC;
624 static int builtin_continue(char **argv) FAST_FUNC;
626 #if ENABLE_HUSH_FUNCTIONS
627 static int builtin_return(char **argv) FAST_FUNC;
630 /* Table of built-in functions. They can be forked or not, depending on
631 * context: within pipes, they fork. As simple commands, they do not.
632 * When used in non-forking context, they can change global variables
633 * in the parent shell process. If forked, of course they cannot.
634 * For example, 'unset foo | whatever' will parse and run, but foo will
635 * still be set at the end. */
636 struct built_in_command {
638 int (*b_function)(char **argv) FAST_FUNC;
641 # define BLTIN(cmd, func, help) { cmd, func, help }
643 # define BLTIN(cmd, func, help) { cmd, func }
647 static const struct built_in_command bltins1[] = {
648 BLTIN("." , builtin_source , "Run commands in a file"),
649 BLTIN(":" , builtin_true , NULL),
651 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
653 #if ENABLE_HUSH_LOOPS
654 BLTIN("break" , builtin_break , "Exit from a loop"),
656 BLTIN("cd" , builtin_cd , "Change directory"),
657 #if ENABLE_HUSH_LOOPS
658 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
660 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
661 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
662 BLTIN("exit" , builtin_exit , "Exit"),
663 BLTIN("export" , builtin_export , "Set environment variables"),
665 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
668 BLTIN("help" , builtin_help , NULL),
671 BLTIN("jobs" , builtin_jobs , "List jobs"),
673 #if ENABLE_HUSH_LOCAL
674 BLTIN("local" , builtin_local , "Set local variables"),
677 BLTIN("memleak" , builtin_memleak , NULL),
679 BLTIN("read" , builtin_read , "Input into variable"),
680 #if ENABLE_HUSH_FUNCTIONS
681 BLTIN("return" , builtin_return , "Return from a function"),
683 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
684 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
685 #if ENABLE_HUSH_BASH_COMPAT
686 BLTIN("source" , builtin_source , "Run commands in a file"),
688 BLTIN("trap" , builtin_trap , "Trap signals"),
689 BLTIN("type" , builtin_type , "Show command type"),
690 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
691 BLTIN("umask" , builtin_umask , "Set file creation mask"),
692 BLTIN("unset" , builtin_unset , "Unset variables"),
693 BLTIN("wait" , builtin_wait , "Wait for process"),
695 /* For now, echo and test are unconditionally enabled.
696 * Maybe make it configurable? */
697 static const struct built_in_command bltins2[] = {
698 BLTIN("[" , builtin_test , NULL),
699 BLTIN("echo" , builtin_echo , NULL),
701 BLTIN("printf" , builtin_printf , NULL),
703 BLTIN("pwd" , builtin_pwd , NULL),
704 BLTIN("test" , builtin_test , NULL),
711 /* prevent disasters with G.debug_indent < 0 */
712 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
713 # define debug_enter() (G.debug_indent++)
714 # define debug_leave() (G.debug_indent--)
716 # define indent() ((void)0)
717 # define debug_enter() ((void)0)
718 # define debug_leave() ((void)0)
722 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
725 #ifndef debug_printf_parse
726 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
729 #ifndef debug_printf_exec
730 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
733 #ifndef debug_printf_env
734 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
737 #ifndef debug_printf_jobs
738 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
739 # define DEBUG_JOBS 1
741 # define DEBUG_JOBS 0
744 #ifndef debug_printf_expand
745 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
746 # define DEBUG_EXPAND 1
748 # define DEBUG_EXPAND 0
751 #ifndef debug_printf_varexp
752 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
755 #ifndef debug_printf_glob
756 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
757 # define DEBUG_GLOB 1
759 # define DEBUG_GLOB 0
762 #ifndef debug_printf_list
763 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
766 #ifndef debug_printf_subst
767 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
770 #ifndef debug_printf_clean
771 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
772 # define DEBUG_CLEAN 1
774 # define DEBUG_CLEAN 0
778 static void debug_print_strings(const char *prefix, char **vv)
781 fprintf(stderr, "%s:\n", prefix);
783 fprintf(stderr, " '%s'\n", *vv++);
786 # define debug_print_strings(prefix, vv) ((void)0)
790 /* Leak hunting. Use hush_leaktool.sh for post-processing.
793 static void *xxmalloc(int lineno, size_t size)
795 void *ptr = xmalloc((size + 0xff) & ~0xff);
796 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
799 static void *xxrealloc(int lineno, void *ptr, size_t size)
801 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
802 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
805 static char *xxstrdup(int lineno, const char *str)
807 char *ptr = xstrdup(str);
808 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
811 static void xxfree(void *ptr)
813 fdprintf(2, "free %p\n", ptr);
816 #define xmalloc(s) xxmalloc(__LINE__, s)
817 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
818 #define xstrdup(s) xxstrdup(__LINE__, s)
819 #define free(p) xxfree(p)
823 /* Syntax and runtime errors. They always abort scripts.
824 * In interactive use they usually discard unparsed and/or unexecuted commands
825 * and return to the prompt.
826 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
829 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
830 # define syntax_error(lineno, msg) syntax_error(msg)
831 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
832 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
833 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
834 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
837 static void die_if_script(unsigned lineno, const char *fmt, ...)
842 bb_error_msg("hush.c:%u", lineno);
845 bb_verror_msg(fmt, p, NULL);
847 if (!G_interactive_fd)
851 static void syntax_error(unsigned lineno, const char *msg)
854 die_if_script(lineno, "syntax error: %s", msg);
856 die_if_script(lineno, "syntax error", NULL);
859 static void syntax_error_at(unsigned lineno, const char *msg)
861 die_if_script(lineno, "syntax error at '%s'", msg);
864 static void syntax_error_unterm_str(unsigned lineno, const char *s)
866 die_if_script(lineno, "syntax error: unterminated %s", s);
869 /* It so happens that all such cases are totally fatal
870 * even if shell is interactive: EOF while looking for closing
871 * delimiter. There is nowhere to read stuff from after that,
872 * it's EOF! The only choice is to terminate.
874 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
875 static void syntax_error_unterm_ch(unsigned lineno, char ch)
877 char msg[2] = { ch, '\0' };
878 syntax_error_unterm_str(lineno, msg);
882 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
887 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
891 # undef die_if_script
893 # undef syntax_error_at
894 # undef syntax_error_unterm_ch
895 # undef syntax_error_unterm_str
896 # undef syntax_error_unexpected_ch
898 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
899 # define syntax_error(msg) syntax_error(__LINE__, msg)
900 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
901 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
902 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
903 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
907 #if ENABLE_HUSH_INTERACTIVE
908 static void cmdedit_update_prompt(void);
910 # define cmdedit_update_prompt() ((void)0)
916 /* Replace each \x with x in place, return ptr past NUL. */
917 static char *unbackslash(char *src)
919 char *dst = src = strchrnul(src, '\\');
923 if ((*dst++ = *src++) == '\0')
929 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
950 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
951 v[count1 + count2] = NULL;
954 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
958 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
960 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
961 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
964 #define add_strings_to_strings(strings, add, need_to_dup) \
965 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
968 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
969 static char **add_string_to_strings(char **strings, char *add)
974 return add_strings_to_strings(strings, v, /*dup:*/ 0);
977 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
979 char **ptr = add_string_to_strings(strings, add);
980 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
983 #define add_string_to_strings(strings, add) \
984 xx_add_string_to_strings(__LINE__, strings, add)
987 static void free_strings(char **strings)
1002 /* Helpers for setting new $n and restoring them back
1004 typedef struct save_arg_t {
1008 smallint sv_g_malloced;
1011 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1015 sv->sv_argv0 = argv[0];
1016 sv->sv_g_argv = G.global_argv;
1017 sv->sv_g_argc = G.global_argc;
1018 sv->sv_g_malloced = G.global_args_malloced;
1020 argv[0] = G.global_argv[0]; /* retain $0 */
1021 G.global_argv = argv;
1022 G.global_args_malloced = 0;
1030 static void restore_G_args(save_arg_t *sv, char **argv)
1034 if (G.global_args_malloced) {
1035 /* someone ran "set -- arg1 arg2 ...", undo */
1037 while (*++pp) /* note: does not free $0 */
1039 free(G.global_argv);
1041 argv[0] = sv->sv_argv0;
1042 G.global_argv = sv->sv_g_argv;
1043 G.global_argc = sv->sv_g_argc;
1044 G.global_args_malloced = sv->sv_g_malloced;
1048 /* Basic theory of signal handling in shell
1049 * ========================================
1050 * This does not describe what hush does, rather, it is current understanding
1051 * what it _should_ do. If it doesn't, it's a bug.
1052 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1054 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1055 * is finished or backgrounded. It is the same in interactive and
1056 * non-interactive shells, and is the same regardless of whether
1057 * a user trap handler is installed or a shell special one is in effect.
1058 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1059 * backgrounds (i.e. stops) or kills all members of currently running
1062 * Wait builtin in interruptible by signals for which user trap is set
1063 * or by SIGINT in interactive shell.
1065 * Trap handlers will execute even within trap handlers. (right?)
1067 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1068 * except for handlers set to '' (empty string).
1070 * If job control is off, backgrounded commands ("cmd &")
1071 * have SIGINT, SIGQUIT set to SIG_IGN.
1073 * Commands which are run in command substitution ("`cmd`")
1074 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1076 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1077 * by the shell from its parent.
1079 * Signals which differ from SIG_DFL action
1080 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1083 * SIGTERM (interactive): ignore
1084 * SIGHUP (interactive):
1085 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1086 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1087 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1088 * that all pipe members are stopped. Try this in bash:
1089 * while :; do :; done - ^Z does not background it
1090 * (while :; do :; done) - ^Z backgrounds it
1091 * SIGINT (interactive): wait for last pipe, ignore the rest
1092 * of the command line, show prompt. NB: ^C does not send SIGINT
1093 * to interactive shell while shell is waiting for a pipe,
1094 * since shell is bg'ed (is not in foreground process group).
1095 * Example 1: this waits 5 sec, but does not execute ls:
1096 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1097 * Example 2: this does not wait and does not execute ls:
1098 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1099 * Example 3: this does not wait 5 sec, but executes ls:
1100 * "sleep 5; ls -l" + press ^C
1102 * (What happens to signals which are IGN on shell start?)
1103 * (What happens with signal mask on shell start?)
1105 * Implementation in hush
1106 * ======================
1107 * We use in-kernel pending signal mask to determine which signals were sent.
1108 * We block all signals which we don't want to take action immediately,
1109 * i.e. we block all signals which need to have special handling as described
1110 * above, and all signals which have traps set.
1111 * After each pipe execution, we extract any pending signals via sigtimedwait()
1114 * unsigned non_DFL_mask: a mask of such "special" signals
1115 * sigset_t blocked_set: current blocked signal set
1118 * clear bit in blocked_set unless it is also in non_DFL_mask
1119 * "trap 'cmd' SIGxxx":
1120 * set bit in blocked_set (even if 'cmd' is '')
1121 * after [v]fork, if we plan to be a shell:
1122 * unblock signals with special interactive handling
1123 * (child shell is not interactive),
1124 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1125 * after [v]fork, if we plan to exec:
1126 * POSIX says fork clears pending signal mask in child - no need to clear it.
1127 * Restore blocked signal set to one inherited by shell just prior to exec.
1129 * Note: as a result, we do not use signal handlers much. The only uses
1130 * are to count SIGCHLDs
1131 * and to restore tty pgrp on signal-induced exit.
1134 * Standard says "When a subshell is entered, traps that are not being ignored
1135 * are set to the default actions". bash interprets it so that traps which
1136 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1139 SPECIAL_INTERACTIVE_SIGS = 0
1144 SPECIAL_JOB_SIGS = 0
1152 #if ENABLE_HUSH_FAST
1153 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1156 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1162 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1163 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1164 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1165 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1167 /* Restores tty foreground process group, and exits.
1168 * May be called as signal handler for fatal signal
1169 * (will resend signal to itself, producing correct exit state)
1170 * or called directly with -EXITCODE.
1171 * We also call it if xfunc is exiting. */
1172 static void sigexit(int sig) NORETURN;
1173 static void sigexit(int sig)
1175 /* Disable all signals: job control, SIGPIPE, etc. */
1176 sigprocmask_allsigs(SIG_BLOCK);
1178 /* Careful: we can end up here after [v]fork. Do not restore
1179 * tty pgrp then, only top-level shell process does that */
1180 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1181 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1183 /* Not a signal, just exit */
1187 kill_myself_with_sig(sig); /* does not return */
1191 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1192 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1196 /* Restores tty foreground process group, and exits. */
1197 static void hush_exit(int exitcode) NORETURN;
1198 static void hush_exit(int exitcode)
1200 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1201 /* Prevent recursion:
1202 * trap "echo Hi; exit" EXIT; exit
1204 char *argv[] = { NULL, G.traps[0], NULL };
1213 sigexit(- (exitcode & 0xff));
1219 static int check_and_run_traps(int sig)
1221 static const struct timespec zero_timespec = { 0, 0 };
1222 smalluint save_rcode;
1228 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1233 if (G.traps && G.traps[sig]) {
1234 if (G.traps[sig][0]) {
1235 /* We have user-defined handler */
1236 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1237 save_rcode = G.last_exitcode;
1240 G.last_exitcode = save_rcode;
1241 } /* else: "" trap, ignoring signal */
1244 /* not a trap: special action */
1246 #if ENABLE_HUSH_FAST
1249 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1253 /* Builtin was ^C'ed, make it look prettier: */
1260 /* bash is observed to signal whole process groups,
1261 * not individual processes */
1262 for (job = G.job_list; job; job = job->next) {
1265 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1266 if (kill(- job->pgrp, SIGHUP) == 0)
1267 kill(- job->pgrp, SIGCONT);
1272 default: /* ignored: */
1273 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1281 static const char *get_cwd(int force)
1283 if (force || G.cwd == NULL) {
1284 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1285 * we must not try to free(bb_msg_unknown) */
1286 if (G.cwd == bb_msg_unknown)
1288 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1290 G.cwd = bb_msg_unknown;
1297 * Shell and environment variable support
1299 static struct variable **get_ptr_to_local_var(const char *name)
1301 struct variable **pp;
1302 struct variable *cur;
1307 while ((cur = *pp) != NULL) {
1308 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1315 static struct variable *get_local_var(const char *name)
1317 struct variable **pp = get_ptr_to_local_var(name);
1323 static const char* FAST_FUNC get_local_var_value(const char *name)
1325 struct variable **pp = get_ptr_to_local_var(name);
1327 return strchr((*pp)->varstr, '=') + 1;
1328 if (strcmp(name, "PPID") == 0)
1329 return utoa(G.root_ppid);
1330 // bash compat: UID? EUID?
1331 #if ENABLE_HUSH_RANDOM_SUPPORT
1332 if (strcmp(name, "RANDOM") == 0) {
1333 return utoa(next_random(&G.random_gen));
1339 /* str holds "NAME=VAL" and is expected to be malloced.
1340 * We take ownership of it.
1342 * 0: do not change export flag
1343 * (if creating new variable, flag will be 0)
1344 * 1: set export flag and putenv the variable
1345 * -1: clear export flag and unsetenv the variable
1346 * flg_read_only is set only when we handle -R var=val
1348 #if !BB_MMU && ENABLE_HUSH_LOCAL
1349 /* all params are used */
1350 #elif BB_MMU && ENABLE_HUSH_LOCAL
1351 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1352 set_local_var(str, flg_export, local_lvl)
1353 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1354 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1355 set_local_var(str, flg_export)
1356 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1357 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1358 set_local_var(str, flg_export, flg_read_only)
1360 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1362 struct variable **var_pp;
1363 struct variable *cur;
1367 eq_sign = strchr(str, '=');
1368 if (!eq_sign) { /* not expected to ever happen? */
1373 name_len = eq_sign - str + 1; /* including '=' */
1374 var_pp = &G.top_var;
1375 while ((cur = *var_pp) != NULL) {
1376 if (strncmp(cur->varstr, str, name_len) != 0) {
1377 var_pp = &cur->next;
1380 /* We found an existing var with this name */
1381 if (cur->flg_read_only) {
1385 bb_error_msg("%s: readonly variable", str);
1389 if (flg_export == -1) { // "&& cur->flg_export" ?
1390 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1395 #if ENABLE_HUSH_LOCAL
1396 if (cur->func_nest_level < local_lvl) {
1397 /* New variable is declared as local,
1398 * and existing one is global, or local
1399 * from enclosing function.
1400 * Remove and save old one: */
1401 *var_pp = cur->next;
1402 cur->next = *G.shadowed_vars_pp;
1403 *G.shadowed_vars_pp = cur;
1404 /* bash 3.2.33(1) and exported vars:
1406 * # f() { local z=a; env | grep ^z; }
1412 if (cur->flg_export)
1417 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1422 if (cur->max_len != 0) {
1423 if (cur->max_len >= strlen(str)) {
1424 /* This one is from startup env, reuse space */
1425 strcpy(cur->varstr, str);
1429 /* max_len == 0 signifies "malloced" var, which we can
1430 * (and has to) free */
1434 goto set_str_and_exp;
1437 /* Not found - create new variable struct */
1438 cur = xzalloc(sizeof(*cur));
1439 #if ENABLE_HUSH_LOCAL
1440 cur->func_nest_level = local_lvl;
1442 cur->next = *var_pp;
1448 cur->flg_read_only = flg_read_only;
1451 if (flg_export == 1)
1452 cur->flg_export = 1;
1453 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1454 cmdedit_update_prompt();
1455 if (cur->flg_export) {
1456 if (flg_export == -1) {
1457 cur->flg_export = 0;
1458 /* unsetenv was already done */
1460 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1461 return putenv(cur->varstr);
1467 /* Used at startup and after each cd */
1468 static void set_pwd_var(int exp)
1470 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1471 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1474 static int unset_local_var_len(const char *name, int name_len)
1476 struct variable *cur;
1477 struct variable **var_pp;
1480 return EXIT_SUCCESS;
1481 var_pp = &G.top_var;
1482 while ((cur = *var_pp) != NULL) {
1483 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1484 if (cur->flg_read_only) {
1485 bb_error_msg("%s: readonly variable", name);
1486 return EXIT_FAILURE;
1488 *var_pp = cur->next;
1489 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1490 bb_unsetenv(cur->varstr);
1491 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1492 cmdedit_update_prompt();
1496 return EXIT_SUCCESS;
1498 var_pp = &cur->next;
1500 return EXIT_SUCCESS;
1503 static int unset_local_var(const char *name)
1505 return unset_local_var_len(name, strlen(name));
1508 static void unset_vars(char **strings)
1516 const char *eq = strchrnul(*v, '=');
1517 unset_local_var_len(*v, (int)(eq - *v));
1523 #if ENABLE_SH_MATH_SUPPORT
1524 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1525 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1526 static char* FAST_FUNC endofname(const char *name)
1534 if (!is_in_name(*p))
1541 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1543 char *var = xasprintf("%s=%s", name, val);
1544 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1549 * Helpers for "var1=val1 var2=val2 cmd" feature
1551 static void add_vars(struct variable *var)
1553 struct variable *next;
1557 var->next = G.top_var;
1559 if (var->flg_export) {
1560 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1561 putenv(var->varstr);
1563 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1569 static struct variable *set_vars_and_save_old(char **strings)
1572 struct variable *old = NULL;
1578 struct variable *var_p;
1579 struct variable **var_pp;
1582 eq = strchr(*s, '=');
1585 var_pp = get_ptr_to_local_var(*s);
1588 /* Remove variable from global linked list */
1590 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1591 *var_pp = var_p->next;
1592 /* Add it to returned list */
1596 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1607 static int FAST_FUNC static_get(struct in_str *i)
1616 static int FAST_FUNC static_peek(struct in_str *i)
1621 #if ENABLE_HUSH_INTERACTIVE
1623 static void cmdedit_update_prompt(void)
1625 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1626 G.PS1 = get_local_var_value("PS1");
1629 G.PS2 = get_local_var_value("PS2");
1637 static const char* setup_prompt_string(int promptmode)
1639 const char *prompt_str;
1640 debug_printf("setup_prompt_string %d ", promptmode);
1641 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1642 /* Set up the prompt */
1643 if (promptmode == 0) { /* PS1 */
1645 /* bash uses $PWD value, even if it is set by user.
1646 * It uses current dir only if PWD is unset.
1647 * We always use current dir. */
1648 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1653 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1654 debug_printf("result '%s'\n", prompt_str);
1658 static void get_user_input(struct in_str *i)
1661 const char *prompt_str;
1663 prompt_str = setup_prompt_string(i->promptmode);
1664 #if ENABLE_FEATURE_EDITING
1665 /* Enable command line editing only while a command line
1666 * is actually being read */
1669 /* buglet: SIGINT will not make new prompt to appear _at once_,
1670 * only after <Enter>. (^C will work) */
1671 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1672 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1673 check_and_run_traps(0);
1674 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1675 i->eof_flag = (r < 0);
1676 if (i->eof_flag) { /* EOF/error detected */
1677 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1678 G.user_input_buf[1] = '\0';
1683 fputs(prompt_str, stdout);
1685 G.user_input_buf[0] = r = fgetc(i->file);
1686 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1687 //do we need check_and_run_traps(0)? (maybe only if stdin)
1688 } while (G.flag_SIGINT);
1689 i->eof_flag = (r == EOF);
1691 i->p = G.user_input_buf;
1694 #endif /* INTERACTIVE */
1696 /* This is the magic location that prints prompts
1697 * and gets data back from the user */
1698 static int FAST_FUNC file_get(struct in_str *i)
1702 /* If there is data waiting, eat it up */
1703 if (i->p && *i->p) {
1704 #if ENABLE_HUSH_INTERACTIVE
1708 if (i->eof_flag && !*i->p)
1710 /* note: ch is never NUL */
1712 /* need to double check i->file because we might be doing something
1713 * more complicated by now, like sourcing or substituting. */
1714 #if ENABLE_HUSH_INTERACTIVE
1715 if (G_interactive_fd && i->promptme && i->file == stdin) {
1718 } while (!*i->p); /* need non-empty line */
1719 i->promptmode = 1; /* PS2 */
1724 do ch = fgetc(i->file); while (ch == '\0');
1726 debug_printf("file_get: got '%c' %d\n", ch, ch);
1727 #if ENABLE_HUSH_INTERACTIVE
1734 /* All callers guarantee this routine will never
1735 * be used right after a newline, so prompting is not needed.
1737 static int FAST_FUNC file_peek(struct in_str *i)
1740 if (i->p && *i->p) {
1741 if (i->eof_flag && !i->p[1])
1744 /* note: ch is never NUL */
1746 do ch = fgetc(i->file); while (ch == '\0');
1747 i->eof_flag = (ch == EOF);
1748 i->peek_buf[0] = ch;
1749 i->peek_buf[1] = '\0';
1751 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1755 static void setup_file_in_str(struct in_str *i, FILE *f)
1757 i->peek = file_peek;
1759 #if ENABLE_HUSH_INTERACTIVE
1761 i->promptmode = 0; /* PS1 */
1767 static void setup_string_in_str(struct in_str *i, const char *s)
1769 i->peek = static_peek;
1770 i->get = static_get;
1771 #if ENABLE_HUSH_INTERACTIVE
1773 i->promptmode = 0; /* PS1 */
1783 #define B_CHUNK (32 * sizeof(char*))
1785 static void o_reset_to_empty_unquoted(o_string *o)
1793 static void o_free(o_string *o)
1796 memset(o, 0, sizeof(*o));
1799 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1804 static void o_grow_by(o_string *o, int len)
1806 if (o->length + len > o->maxlen) {
1807 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1808 o->data = xrealloc(o->data, 1 + o->maxlen);
1812 static void o_addchr(o_string *o, int ch)
1814 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1816 o->data[o->length] = ch;
1818 o->data[o->length] = '\0';
1821 static void o_addblock(o_string *o, const char *str, int len)
1824 memcpy(&o->data[o->length], str, len);
1826 o->data[o->length] = '\0';
1829 static void o_addstr(o_string *o, const char *str)
1831 o_addblock(o, str, strlen(str));
1834 static void nommu_addchr(o_string *o, int ch)
1840 # define nommu_addchr(o, str) ((void)0)
1843 static void o_addstr_with_NUL(o_string *o, const char *str)
1845 o_addblock(o, str, strlen(str) + 1);
1848 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1853 && (*str != '*' && *str != '?' && *str != '[')
1861 #undef HUSH_BRACE_EXP
1863 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
1864 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
1865 * Apparently, on unquoted $v bash still does globbing
1866 * ("v='*.txt'; echo $v" prints all .txt files),
1867 * but NOT brace expansion! Thus, there should be TWO independent
1868 * quoting mechanisms on $v expansion side: one protects
1869 * $v from brace expansion, and other additionally protects "$v" against globbing.
1870 * We have only second one.
1873 #ifdef HUSH_BRACE_EXP
1874 # define MAYBE_BRACES "{}"
1876 # define MAYBE_BRACES ""
1879 /* My analysis of quoting semantics tells me that state information
1880 * is associated with a destination, not a source.
1882 static void o_addqchr(o_string *o, int ch)
1885 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
1890 o->data[o->length] = '\\';
1893 o->data[o->length] = ch;
1895 o->data[o->length] = '\0';
1898 static void o_addQchr(o_string *o, int ch)
1901 if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
1903 o->data[o->length] = '\\';
1907 o->data[o->length] = ch;
1909 o->data[o->length] = '\0';
1912 static void o_addQstr(o_string *o, const char *str, int len)
1915 o_addblock(o, str, len);
1921 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
1922 if (ordinary_cnt > len) /* paranoia */
1924 o_addblock(o, str, ordinary_cnt);
1925 if (ordinary_cnt == len)
1927 str += ordinary_cnt;
1928 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1932 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
1934 o->data[o->length] = '\\';
1938 o->data[o->length] = ch;
1940 o->data[o->length] = '\0';
1944 /* A special kind of o_string for $VAR and `cmd` expansion.
1945 * It contains char* list[] at the beginning, which is grown in 16 element
1946 * increments. Actual string data starts at the next multiple of 16 * (char*).
1947 * list[i] contains an INDEX (int!) into this string data.
1948 * It means that if list[] needs to grow, data needs to be moved higher up
1949 * but list[i]'s need not be modified.
1950 * NB: remembering how many list[i]'s you have there is crucial.
1951 * o_finalize_list() operation post-processes this structure - calculates
1952 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1954 #if DEBUG_EXPAND || DEBUG_GLOB
1955 static void debug_print_list(const char *prefix, o_string *o, int n)
1957 char **list = (char**)o->data;
1958 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1962 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1963 prefix, list, n, string_start, o->length, o->maxlen);
1966 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1967 o->data + (int)list[i] + string_start,
1968 o->data + (int)list[i] + string_start);
1972 const char *p = o->data + (int)list[n - 1] + string_start;
1974 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1978 # define debug_print_list(prefix, o, n) ((void)0)
1981 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1982 * in list[n] so that it points past last stored byte so far.
1983 * It returns n+1. */
1984 static int o_save_ptr_helper(o_string *o, int n)
1986 char **list = (char**)o->data;
1990 if (!o->has_empty_slot) {
1991 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1992 string_len = o->length - string_start;
1993 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1994 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1995 /* list[n] points to string_start, make space for 16 more pointers */
1996 o->maxlen += 0x10 * sizeof(list[0]);
1997 o->data = xrealloc(o->data, o->maxlen + 1);
1998 list = (char**)o->data;
1999 memmove(list + n + 0x10, list + n, string_len);
2000 o->length += 0x10 * sizeof(list[0]);
2002 debug_printf_list("list[%d]=%d string_start=%d\n",
2003 n, string_len, string_start);
2006 /* We have empty slot at list[n], reuse without growth */
2007 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2008 string_len = o->length - string_start;
2009 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2010 n, string_len, string_start);
2011 o->has_empty_slot = 0;
2013 list[n] = (char*)(ptrdiff_t)string_len;
2017 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2018 static int o_get_last_ptr(o_string *o, int n)
2020 char **list = (char**)o->data;
2021 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2023 return ((int)(ptrdiff_t)list[n-1]) + string_start;
2026 #ifdef HUSH_BRACE_EXP
2027 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2028 * first, it processes even {a} (no commas), second,
2029 * I didn't manage to make it return strings when they don't match
2030 * existing files. Need to re-implement it.
2034 static int glob_needed(const char *s)
2043 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2049 /* Return pointer to next closing brace or to comma */
2050 static const char *next_brace_sub(const char *cp)
2054 while (*cp != '\0') {
2061 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2063 if (*cp++ == '{') /*}*/
2067 return *cp != '\0' ? cp : NULL;
2069 /* Recursive brace globber. Note: may garble pattern[]. */
2070 static int glob_brace(char *pattern, o_string *o, int n)
2072 char *new_pattern_buf;
2079 debug_printf_glob("glob_brace('%s')\n", pattern);
2085 if (*begin == '{') /*}*/ {
2086 /* Find the first sub-pattern and at the same time
2087 * find the rest after the closing brace */
2088 next = next_brace_sub(begin);
2090 /* An illegal expression */
2093 /*{*/ if (*next == '}') {
2094 /* "{abc}" with no commas - illegal
2095 * brace expr, disregard and skip it */
2101 if (*begin == '\\' && begin[1] != '\0')
2105 debug_printf_glob("begin:%s\n", begin);
2106 debug_printf_glob("next:%s\n", next);
2108 /* Now find the end of the whole brace expression */
2110 /*{*/ while (*rest != '}') {
2111 rest = next_brace_sub(rest);
2113 /* An illegal expression */
2116 debug_printf_glob("rest:%s\n", rest);
2118 rest_len = strlen(++rest) + 1;
2120 /* We are sure the brace expression is well-formed */
2122 /* Allocate working buffer large enough for our work */
2123 new_pattern_buf = xmalloc(strlen(pattern));
2125 /* We have a brace expression. BEGIN points to the opening {,
2126 * NEXT points past the terminator of the first element, and REST
2127 * points past the final }. We will accumulate result names from
2128 * recursive runs for each brace alternative in the buffer using
2133 /* Construct the new glob expression */
2136 mempcpy(new_pattern_buf,
2137 /* We know the prefix for all sub-patterns */
2138 pattern, begin - pattern),
2142 /* Note: glob_brace() may garble new_pattern_buf[].
2143 * That's why we re-copy prefix every time (1st memcpy above).
2145 n = glob_brace(new_pattern_buf, o, n);
2146 /*{*/ if (*next == '}') {
2147 /* We saw the last entry */
2151 next = next_brace_sub(next);
2153 free(new_pattern_buf);
2161 memset(&globdata, 0, sizeof(globdata));
2162 gr = glob(pattern, 0, NULL, &globdata);
2163 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2165 if (gr == GLOB_NOMATCH) {
2166 globfree(&globdata);
2167 /* NB: garbles parameter */
2168 unbackslash(pattern);
2169 o_addstr_with_NUL(o, pattern);
2170 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2171 return o_save_ptr_helper(o, n);
2173 if (gr == GLOB_NOSPACE)
2174 bb_error_msg_and_die(bb_msg_memory_exhausted);
2175 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2176 * but we didn't specify it. Paranoia again. */
2177 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2179 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2180 char **argv = globdata.gl_pathv;
2182 o_addstr_with_NUL(o, *argv);
2183 n = o_save_ptr_helper(o, n);
2189 globfree(&globdata);
2193 /* Performs globbing on last list[],
2194 * saving each result as a new list[].
2196 static int o_glob(o_string *o, int n)
2198 char *pattern, *copy;
2200 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2202 return o_save_ptr_helper(o, n);
2203 pattern = o->data + o_get_last_ptr(o, n);
2204 debug_printf_glob("glob pattern '%s'\n", pattern);
2205 if (!glob_needed(pattern)) {
2206 /* unbackslash last string in o in place, fix length */
2207 o->length = unbackslash(pattern) - o->data;
2208 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2209 return o_save_ptr_helper(o, n);
2212 copy = xstrdup(pattern);
2213 /* "forget" pattern in o */
2214 o->length = pattern - o->data;
2215 n = glob_brace(copy, o, n);
2218 debug_print_list("o_glob returning", o, n);
2225 static int glob_needed(const char *s)
2234 if (*s == '*' || *s == '[' || *s == '?')
2240 /* Performs globbing on last list[],
2241 * saving each result as a new list[].
2243 static int o_glob(o_string *o, int n)
2249 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
2251 return o_save_ptr_helper(o, n);
2252 pattern = o->data + o_get_last_ptr(o, n);
2253 debug_printf_glob("glob pattern '%s'\n", pattern);
2254 if (!glob_needed(pattern)) {
2256 /* unbackslash last string in o in place, fix length */
2257 o->length = unbackslash(pattern) - o->data;
2258 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2259 return o_save_ptr_helper(o, n);
2262 memset(&globdata, 0, sizeof(globdata));
2263 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2264 * If we glob "*.\*" and don't find anything, we need
2265 * to fall back to using literal "*.*", but GLOB_NOCHECK
2266 * will return "*.\*"!
2268 gr = glob(pattern, 0, NULL, &globdata);
2269 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2271 if (gr == GLOB_NOMATCH) {
2272 globfree(&globdata);
2275 if (gr == GLOB_NOSPACE)
2276 bb_error_msg_and_die(bb_msg_memory_exhausted);
2277 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2278 * but we didn't specify it. Paranoia again. */
2279 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2281 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2282 char **argv = globdata.gl_pathv;
2283 /* "forget" pattern in o */
2284 o->length = pattern - o->data;
2286 o_addstr_with_NUL(o, *argv);
2287 n = o_save_ptr_helper(o, n);
2293 globfree(&globdata);
2295 debug_print_list("o_glob returning", o, n);
2301 /* If o->o_glob == 1, glob the string so far remembered.
2302 * Otherwise, just finish current list[] and start new */
2303 static int o_save_ptr(o_string *o, int n)
2305 if (o->o_glob) { /* if globbing is requested */
2306 /* If o->has_empty_slot, list[n] was already globbed
2307 * (if it was requested back then when it was filled)
2308 * so don't do that again! */
2309 if (!o->has_empty_slot)
2310 return o_glob(o, n); /* o_save_ptr_helper is inside */
2312 return o_save_ptr_helper(o, n);
2315 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2316 static char **o_finalize_list(o_string *o, int n)
2321 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2323 debug_print_list("finalized", o, n);
2324 debug_printf_expand("finalized n:%d\n", n);
2325 list = (char**)o->data;
2326 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2330 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2336 /* Expansion can recurse */
2337 #if ENABLE_HUSH_TICK
2338 static int process_command_subs(o_string *dest, const char *s);
2340 static char *expand_string_to_string(const char *str);
2342 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2343 parse_stream_dquoted(dest, input, dquote_end)
2345 static int parse_stream_dquoted(o_string *as_string,
2347 struct in_str *input,
2350 /* expand_strvec_to_strvec() takes a list of strings, expands
2351 * all variable references within and returns a pointer to
2352 * a list of expanded strings, possibly with larger number
2353 * of strings. (Think VAR="a b"; echo $VAR).
2354 * This new list is allocated as a single malloc block.
2355 * NULL-terminated list of char* pointers is at the beginning of it,
2356 * followed by strings themself.
2357 * Caller can deallocate entire list by single free(list). */
2359 /* Store given string, finalizing the word and starting new one whenever
2360 * we encounter IFS char(s). This is used for expanding variable values.
2361 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2362 static int expand_on_ifs(o_string *output, int n, const char *str)
2365 int word_len = strcspn(str, G.ifs);
2367 if (output->o_escape || !output->o_glob)
2368 o_addQstr(output, str, word_len);
2369 else /* protect backslashes against globbing up :) */
2370 o_addblock_duplicate_backslash(output, str, word_len);
2373 if (!*str) /* EOL - do not finalize word */
2375 o_addchr(output, '\0');
2376 debug_print_list("expand_on_ifs", output, n);
2377 n = o_save_ptr(output, n);
2378 str += strspn(str, G.ifs); /* skip ifs chars */
2380 debug_print_list("expand_on_ifs[1]", output, n);
2384 /* Helper to expand $((...)) and heredoc body. These act as if
2385 * they are in double quotes, with the exception that they are not :).
2386 * Just the rules are similar: "expand only $var and `cmd`"
2388 * Returns malloced string.
2389 * As an optimization, we return NULL if expansion is not needed.
2391 static char *expand_pseudo_dquoted(const char *str)
2394 struct in_str input;
2395 o_string dest = NULL_O_STRING;
2397 if (strchr(str, '$') == NULL
2398 #if ENABLE_HUSH_TICK
2399 && strchr(str, '`') == NULL
2405 /* We need to expand. Example:
2406 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2408 setup_string_in_str(&input, str);
2409 parse_stream_dquoted(NULL, &dest, &input, EOF);
2410 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2411 exp_str = expand_string_to_string(dest.data);
2412 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2413 o_free_unsafe(&dest);
2417 #if ENABLE_SH_MATH_SUPPORT
2418 static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
2420 arith_eval_hooks_t hooks;
2424 hooks.lookupvar = get_local_var_value;
2425 hooks.setvar = set_local_var_from_halves;
2426 hooks.endofname = endofname;
2427 exp_str = expand_pseudo_dquoted(arg);
2428 res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
2434 /* Expand all variable references in given string, adding words to list[]
2435 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2436 * to be filled). This routine is extremely tricky: has to deal with
2437 * variables/parameters with whitespace, $* and $@, and constructs like
2438 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2439 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2441 /* or_mask is either 0 (normal case) or 0x80 -
2442 * expansion of right-hand side of assignment == 1-element expand.
2443 * It will also do no globbing, and thus we must not backslash-quote!
2450 debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
2451 debug_print_list("expand_vars_to_list", output, n);
2452 n = o_save_ptr(output, n);
2453 debug_print_list("expand_vars_to_list[0]", output, n);
2455 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2458 char *to_be_freed = NULL;
2459 const char *val = NULL;
2460 #if ENABLE_HUSH_TICK
2461 o_string subst_result = NULL_O_STRING;
2463 #if ENABLE_SH_MATH_SUPPORT
2464 char arith_buf[sizeof(arith_t)*3 + 2];
2466 o_addblock(output, arg, p - arg);
2467 debug_print_list("expand_vars_to_list[1]", output, n);
2469 p = strchr(p, SPECIAL_VAR_SYMBOL);
2471 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2472 /* "$@" is special. Even if quoted, it can still
2473 * expand to nothing (not even an empty string) */
2474 if ((first_ch & 0x7f) != '@')
2475 ored_ch |= first_ch;
2477 switch (first_ch & 0x7f) {
2478 /* Highest bit in first_ch indicates that var is double-quoted */
2482 if (!G.global_argv[i])
2484 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2485 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2486 smallint sv = output->o_escape;
2487 /* unquoted var's contents should be globbed, so don't escape */
2488 output->o_escape = 0;
2489 while (G.global_argv[i]) {
2490 n = expand_on_ifs(output, n, G.global_argv[i]);
2491 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2492 if (G.global_argv[i++][0] && G.global_argv[i]) {
2493 /* this argv[] is not empty and not last:
2494 * put terminating NUL, start new word */
2495 o_addchr(output, '\0');
2496 debug_print_list("expand_vars_to_list[2]", output, n);
2497 n = o_save_ptr(output, n);
2498 debug_print_list("expand_vars_to_list[3]", output, n);
2501 output->o_escape = sv;
2503 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2504 * and in this case should treat it like '$*' - see 'else...' below */
2505 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2507 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2508 if (++i >= G.global_argc)
2510 o_addchr(output, '\0');
2511 debug_print_list("expand_vars_to_list[4]", output, n);
2512 n = o_save_ptr(output, n);
2514 } else { /* quoted $*: add as one word */
2516 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2517 if (!G.global_argv[++i])
2520 o_addchr(output, G.ifs[0]);
2524 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2525 /* "Empty variable", used to make "" etc to not disappear */
2529 #if ENABLE_HUSH_TICK
2530 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2533 /* Can't just stuff it into output o_string,
2534 * expanded result may need to be globbed
2535 * and $IFS-splitted */
2536 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2537 G.last_exitcode = process_command_subs(&subst_result, arg);
2538 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
2539 val = subst_result.data;
2542 #if ENABLE_SH_MATH_SUPPORT
2543 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2547 arg++; /* skip '+' */
2548 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2549 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2550 res = expand_and_evaluate_arith(arg, &errcode);
2553 const char *msg = "error in arithmetic";
2556 msg = "exponent less than 0";
2559 msg = "divide by 0";
2562 msg = "expression recursion loop detected";
2567 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2568 sprintf(arith_buf, arith_t_fmt, res);
2573 default: { /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2577 char exp_save = exp_save; /* for compiler */
2578 char *exp_saveptr; /* points to expansion operator */
2579 char *exp_word = exp_word; /* for compiler */
2583 exp_saveptr = arg[1] ? strchr("%#:-=+?", arg[1]) : NULL;
2584 first_char = arg[0] = first_ch & 0x7f;
2587 if (first_char == '#' && arg[1] && !exp_saveptr) {
2588 /* handle length expansion ${#var} */
2592 /* maybe handle parameter expansion */
2593 if (exp_saveptr /* if 2nd char is one of expansion operators */
2594 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
2596 /* ${?:0}, ${#[:]%0} etc */
2597 exp_saveptr = var + 1;
2599 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
2600 exp_saveptr = var+1 + strcspn(var+1, "%#:-=+?");
2602 exp_op = exp_save = *exp_saveptr;
2604 exp_word = exp_saveptr + 1;
2605 if (exp_op == ':') {
2606 exp_op = *exp_word++;
2607 if (ENABLE_HUSH_BASH_COMPAT
2608 && (exp_op == '\0' || !strchr("%#:-=+?"+3, exp_op))
2610 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
2615 *exp_saveptr = '\0';
2616 } /* else: it's not an expansion op, but bare ${var} */
2619 /* lookup the variable in question */
2620 if (isdigit(var[0])) {
2621 /* handle_dollar() should have vetted var for us */
2623 if (i < G.global_argc)
2624 val = G.global_argv[i];
2625 /* else val remains NULL: $N with too big N */
2629 val = utoa(G.root_pid);
2631 case '!': /* bg pid */
2632 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2634 case '?': /* exitcode */
2635 val = utoa(G.last_exitcode);
2637 case '#': /* argc */
2638 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2641 val = get_local_var_value(var);
2645 /* handle any expansions */
2646 if (exp_op == 'L') {
2647 debug_printf_expand("expand: length(%s)=", val);
2648 val = utoa(val ? strlen(val) : 0);
2649 debug_printf_expand("%s\n", val);
2650 } else if (exp_op) {
2651 if (exp_op == '%' || exp_op == '#') {
2652 /* Standard-mandated substring removal ops:
2653 * ${parameter%word} - remove smallest suffix pattern
2654 * ${parameter%%word} - remove largest suffix pattern
2655 * ${parameter#word} - remove smallest prefix pattern
2656 * ${parameter##word} - remove largest prefix pattern
2658 * Word is expanded to produce a glob pattern.
2659 * Then var's value is matched to it and matching part removed.
2664 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2665 if (exp_op == *exp_word) /* ## or %% */
2667 val = to_be_freed = xstrdup(val);
2669 char *exp_exp_word = expand_pseudo_dquoted(exp_word);
2671 exp_word = exp_exp_word;
2672 loc = scan(to_be_freed, exp_word, match_at_left);
2673 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
2674 // exp_op, to_be_freed, exp_word, loc);
2677 if (loc) { /* match was found */
2678 if (match_at_left) /* # or ## */
2684 } else if (exp_op == ':') {
2685 #if ENABLE_HUSH_BASH_COMPAT
2686 /* It's ${var:N[:M]} bashism.
2687 * Note that in encoded form it has TWO parts:
2688 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
2693 beg = expand_and_evaluate_arith(exp_word, &errcode);
2694 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
2695 *p++ = SPECIAL_VAR_SYMBOL;
2697 p = strchr(p, SPECIAL_VAR_SYMBOL);
2699 len = expand_and_evaluate_arith(exp_word, &errcode);
2700 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
2702 if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
2703 if (beg < 0) /* bash compat */
2705 debug_printf_varexp("from val:'%s'\n", val);
2706 if (len == 0 || !val || beg >= strlen(val))
2709 /* Paranoia. What if user entered 9999999999999
2710 * which fits in arith_t but not int? */
2713 val = to_be_freed = xstrndup(val + beg, len);
2715 debug_printf_varexp("val:'%s'\n", val);
2719 die_if_script("malformed ${%s:...}", var);
2722 } else { /* one of "-=+?" */
2723 /* Standard-mandated substitution ops:
2724 * ${var?word} - indicate error if unset
2725 * If var is unset, word (or a message indicating it is unset
2726 * if word is null) is written to standard error
2727 * and the shell exits with a non-zero exit status.
2728 * Otherwise, the value of var is substituted.
2729 * ${var-word} - use default value
2730 * If var is unset, word is substituted.
2731 * ${var=word} - assign and use default value
2732 * If var is unset, word is assigned to var.
2733 * In all cases, final value of var is substituted.
2734 * ${var+word} - use alternative value
2735 * If var is unset, null is substituted.
2736 * Otherwise, word is substituted.
2738 * Word is subjected to tilde expansion, parameter expansion,
2739 * command substitution, and arithmetic expansion.
2740 * If word is not needed, it is not expanded.
2742 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
2743 * but also treat null var as if it is unset.
2745 int use_word = (!val || ((exp_save == ':') && !val[0]));
2747 use_word = !use_word;
2748 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2749 (exp_save == ':') ? "true" : "false", use_word);
2751 to_be_freed = expand_pseudo_dquoted(exp_word);
2753 exp_word = to_be_freed;
2754 if (exp_op == '?') {
2755 /* mimic bash message */
2756 die_if_script("%s: %s",
2758 exp_word[0] ? exp_word : "parameter null or not set"
2760 //TODO: how interactive bash aborts expansion mid-command?
2765 if (exp_op == '=') {
2766 /* ${var=[word]} or ${var:=[word]} */
2767 if (isdigit(var[0]) || var[0] == '#') {
2768 /* mimic bash message */
2769 die_if_script("$%s: cannot assign in this way", var);
2772 char *new_var = xasprintf("%s=%s", var, val);
2773 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2777 } /* one of "-=+?" */
2779 *exp_saveptr = exp_save;
2783 #if ENABLE_HUSH_TICK
2786 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2787 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2789 /* unquoted var's contents should be globbed, so don't escape */
2790 smallint sv = output->o_escape;
2791 output->o_escape = 0;
2792 n = expand_on_ifs(output, n, val);
2794 output->o_escape = sv;
2796 } else { /* quoted $VAR, val will be appended below */
2797 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2800 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2803 o_addQstr(output, val, strlen(val));
2806 /* Do the check to avoid writing to a const string */
2807 if (*p != SPECIAL_VAR_SYMBOL)
2808 *p = SPECIAL_VAR_SYMBOL;
2810 #if ENABLE_HUSH_TICK
2811 o_free(&subst_result);
2814 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2817 debug_print_list("expand_vars_to_list[a]", output, n);
2818 /* this part is literal, and it was already pre-quoted
2819 * if needed (much earlier), do not use o_addQstr here! */
2820 o_addstr_with_NUL(output, arg);
2821 debug_print_list("expand_vars_to_list[b]", output, n);
2822 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2823 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2826 /* allow to reuse list[n] later without re-growth */
2827 output->has_empty_slot = 1;
2829 o_addchr(output, '\0');
2834 static char **expand_variables(char **argv, int or_mask)
2839 o_string output = NULL_O_STRING;
2841 if (or_mask & 0x100) {
2842 output.o_escape = 1; /* protect against globbing for "$var" */
2843 /* (unquoted $var will temporarily switch it off) */
2850 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2853 debug_print_list("expand_variables", &output, n);
2855 /* output.data (malloced in one block) gets returned in "list" */
2856 list = o_finalize_list(&output, n);
2857 debug_print_strings("expand_variables[1]", list);
2861 static char **expand_strvec_to_strvec(char **argv)
2863 return expand_variables(argv, 0x100);
2866 #if ENABLE_HUSH_BASH_COMPAT
2867 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2869 return expand_variables(argv, 0x80);
2873 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2874 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2879 o_string output = NULL_O_STRING;
2884 int is_var = is_well_formed_var_name(*v, '=');
2885 /* is_var * 0x80: singleword expansion for vars */
2886 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2888 /* Subtle! expand_vars_to_list did not glob last word yet.
2889 * It does this only when fed with further data.
2890 * Therefore we set globbing flags AFTER it, not before:
2893 /* if it is not recognizably abc=...; then: */
2894 output.o_escape = !is_var; /* protect against globbing for "$var" */
2895 /* (unquoted $var will temporarily switch it off) */
2896 output.o_glob = !is_var; /* and indeed do globbing */
2899 debug_print_list("expand_cond", &output, n);
2901 /* output.data (malloced in one block) gets returned in "list" */
2902 list = o_finalize_list(&output, n);
2903 debug_print_strings("expand_cond[1]", list);
2908 /* Used for expansion of right hand of assignments */
2909 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2911 static char *expand_string_to_string(const char *str)
2913 char *argv[2], **list;
2915 argv[0] = (char*)str;
2917 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2919 if (!list[0] || list[1])
2920 bb_error_msg_and_die("BUG in varexp2");
2921 /* actually, just move string 2*sizeof(char*) bytes back */
2922 overlapping_strcpy((char*)list, list[0]);
2923 unbackslash((char*)list);
2924 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2928 /* Used for "eval" builtin */
2929 static char* expand_strvec_to_string(char **argv)
2933 list = expand_variables(argv, 0x80);
2934 /* Convert all NULs to spaces */
2939 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2940 bb_error_msg_and_die("BUG in varexp3");
2941 /* bash uses ' ' regardless of $IFS contents */
2946 overlapping_strcpy((char*)list, list[0]);
2947 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2951 static char **expand_assignments(char **argv, int count)
2955 /* Expand assignments into one string each */
2956 for (i = 0; i < count; i++) {
2957 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2965 void re_execute_shell(char ***to_free, const char *s,
2966 char *g_argv0, char **g_argv,
2967 char **builtin_argv) NORETURN;
2969 static void reset_traps_to_defaults(void)
2971 /* This function is always called in a child shell
2972 * after fork (not vfork, NOMMU doesn't use this function).
2977 /* Child shells are not interactive.
2978 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2979 * Testcase: (while :; do :; done) + ^Z should background.
2980 * Same goes for SIGTERM, SIGHUP, SIGINT.
2982 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2983 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
2985 /* Switching off SPECIAL_INTERACTIVE_SIGS.
2986 * Stupid. It can be done with *single* &= op, but we can't use
2987 * the fact that G.blocked_set is implemented as a bitmask
2989 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2993 /* Careful. Only if no trap or trap is not "" */
2994 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
2995 sigdelset(&G.blocked_set, sig);
3002 /* Our homegrown sig mask is saner to work with :) */
3003 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
3005 /* Resetting all traps to default except empty ones */
3006 mask = G.non_DFL_mask;
3007 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
3008 if (!G.traps[sig] || !G.traps[sig][0])
3011 G.traps[sig] = NULL;
3012 /* There is no signal for 0 (EXIT) */
3015 /* There was a trap handler, we just removed it.
3016 * But if sig still has non-DFL handling,
3017 * we should not unblock the sig. */
3020 sigdelset(&G.blocked_set, sig);
3022 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
3027 static void re_execute_shell(char ***to_free, const char *s,
3028 char *g_argv0, char **g_argv,
3029 char **builtin_argv) NORETURN;
3030 static void re_execute_shell(char ***to_free, const char *s,
3031 char *g_argv0, char **g_argv,
3032 char **builtin_argv)
3034 #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
3035 /* delims + 2 * (number of bytes in printed hex numbers) */
3036 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
3037 char *heredoc_argv[4];
3038 struct variable *cur;
3039 # if ENABLE_HUSH_FUNCTIONS
3040 struct function *funcp;
3044 unsigned long long empty_trap_mask;
3046 if (!g_argv0) { /* heredoc */
3047 argv = heredoc_argv;
3048 argv[0] = (char *) G.argv0_for_re_execing;
3049 argv[1] = (char *) "-<";
3050 argv[2] = (char *) s;
3052 pp = &argv[3]; /* used as pointer to empty environment */
3058 if (pp) while (*pp++)
3061 empty_trap_mask = 0;
3064 for (sig = 1; sig < NSIG; sig++) {
3065 if (G.traps[sig] && !G.traps[sig][0])
3066 empty_trap_mask |= 1LL << sig;
3070 sprintf(param_buf, NOMMU_HACK_FMT
3071 , (unsigned) G.root_pid
3072 , (unsigned) G.root_ppid
3073 , (unsigned) G.last_bg_pid
3074 , (unsigned) G.last_exitcode
3077 IF_HUSH_LOOPS(, G.depth_of_loop)
3079 #undef NOMMU_HACK_FMT
3080 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
3081 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
3084 for (cur = G.top_var; cur; cur = cur->next) {
3085 if (!cur->flg_export || cur->flg_read_only)
3088 # if ENABLE_HUSH_FUNCTIONS
3089 for (funcp = G.top_func; funcp; funcp = funcp->next)
3095 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
3096 *pp++ = (char *) G.argv0_for_re_execing;
3098 for (cur = G.top_var; cur; cur = cur->next) {
3099 if (cur->varstr == hush_version_str)
3101 if (cur->flg_read_only) {
3102 *pp++ = (char *) "-R";
3103 *pp++ = cur->varstr;
3104 } else if (!cur->flg_export) {
3105 *pp++ = (char *) "-V";
3106 *pp++ = cur->varstr;
3109 # if ENABLE_HUSH_FUNCTIONS
3110 for (funcp = G.top_func; funcp; funcp = funcp->next) {
3111 *pp++ = (char *) "-F";
3112 *pp++ = funcp->name;
3113 *pp++ = funcp->body_as_string;
3116 /* We can pass activated traps here. Say, -Tnn:trap_string
3118 * However, POSIX says that subshells reset signals with traps
3120 * I tested bash-3.2 and it not only does that with true subshells
3121 * of the form ( list ), but with any forked children shells.
3122 * I set trap "echo W" WINCH; and then tried:
3124 * { echo 1; sleep 20; echo 2; } &
3125 * while true; do echo 1; sleep 20; echo 2; break; done &
3126 * true | { echo 1; sleep 20; echo 2; } | cat
3128 * In all these cases sending SIGWINCH to the child shell
3129 * did not run the trap. If I add trap "echo V" WINCH;
3130 * _inside_ group (just before echo 1), it works.
3132 * I conclude it means we don't need to pass active traps here.
3133 * Even if we would use signal handlers instead of signal masking
3134 * in order to implement trap handling,
3135 * exec syscall below resets signals to SIG_DFL for us.
3137 *pp++ = (char *) "-c";
3140 while (*++builtin_argv)
3141 *pp++ = *builtin_argv;
3142 *pp++ = (char *) "";
3147 /* *pp = NULL; - is already there */
3151 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
3152 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3153 execve(bb_busybox_exec_path, argv, pp);
3154 /* Fallback. Useful for init=/bin/hush usage etc */
3155 if (argv[0][0] == '/')
3156 execve(argv[0], argv, pp);
3157 xfunc_error_retval = 127;
3158 bb_error_msg_and_die("can't re-execute the shell");
3160 #endif /* !BB_MMU */
3163 static void setup_heredoc(struct redir_struct *redir)
3165 struct fd_pair pair;
3168 /* the _body_ of heredoc (misleading field name) */
3169 const char *heredoc = redir->rd_filename;
3176 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
3177 expanded = expand_pseudo_dquoted(heredoc);
3181 len = strlen(heredoc);
3183 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
3185 xmove_fd(pair.rd, redir->rd_fd);
3187 /* Try writing without forking. Newer kernels have
3188 * dynamically growing pipes. Must use non-blocking write! */
3191 written = write(pair.wr, heredoc, len);
3202 ndelay_off(pair.wr);
3204 /* Okay, pipe buffer was not big enough */
3205 /* Note: we must not create a stray child (bastard? :)
3206 * for the unsuspecting parent process. Child creates a grandchild
3207 * and exits before parent execs the process which consumes heredoc
3208 * (that exec happens after we return from this function) */
3214 bb_perror_msg_and_die("vfork");
3217 disable_restore_tty_pgrp_on_exit();
3218 pid = BB_MMU ? fork() : vfork();
3220 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3224 close(redir->rd_fd); /* read side of the pipe */
3226 full_write(pair.wr, heredoc, len); /* may loop or block */
3229 /* Delegate blocking writes to another process */
3230 xmove_fd(pair.wr, STDOUT_FILENO);
3231 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
3235 #if ENABLE_HUSH_FAST
3237 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3239 enable_restore_tty_pgrp_on_exit();
3245 wait(NULL); /* wait till child has died */
3248 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
3249 * and stderr if they are redirected. */
3250 static int setup_redirects(struct command *prog, int squirrel[])
3253 struct redir_struct *redir;
3255 for (redir = prog->redirects; redir; redir = redir->next) {
3256 if (redir->rd_type == REDIRECT_HEREDOC2) {
3257 /* rd_fd<<HERE case */
3258 if (squirrel && redir->rd_fd < 3
3259 && squirrel[redir->rd_fd] < 0
3261 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3263 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
3265 debug_printf_parse("set heredoc '%s'\n",
3266 redir->rd_filename);
3267 setup_heredoc(redir);
3271 if (redir->rd_dup == REDIRFD_TO_FILE) {
3272 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
3274 if (redir->rd_filename == NULL) {
3275 /* Something went wrong in the parse.
3276 * Pretend it didn't happen */
3277 bb_error_msg("bug in redirect parse");
3280 mode = redir_table[redir->rd_type].mode;
3281 p = expand_string_to_string(redir->rd_filename);
3282 openfd = open_or_warn(p, mode);
3285 /* this could get lost if stderr has been redirected, but
3286 * bash and ash both lose it as well (though zsh doesn't!) */
3287 //what the above comment tries to say?
3291 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
3292 openfd = redir->rd_dup;
3295 if (openfd != redir->rd_fd) {
3296 if (squirrel && redir->rd_fd < 3
3297 && squirrel[redir->rd_fd] < 0
3299 squirrel[redir->rd_fd] = dup(redir->rd_fd);
3301 if (openfd == REDIRFD_CLOSE) {
3302 /* "n>-" means "close me" */
3303 close(redir->rd_fd);
3305 xdup2(openfd, redir->rd_fd);
3306 if (redir->rd_dup == REDIRFD_TO_FILE)
3314 static void restore_redirects(int squirrel[])
3317 for (i = 0; i < 3; i++) {
3320 /* We simply die on error */
3327 static void free_pipe_list(struct pipe *head);
3329 /* Return code is the exit status of the pipe */
3330 static void free_pipe(struct pipe *pi)
3333 struct command *command;
3334 struct redir_struct *r, *rnext;
3337 if (pi->stopped_cmds > 0) /* why? */
3339 debug_printf_clean("run pipe: (pid %d)\n", getpid());
3340 for (i = 0; i < pi->num_cmds; i++) {
3341 command = &pi->cmds[i];
3342 debug_printf_clean(" command %d:\n", i);
3343 if (command->argv) {
3344 for (a = 0, p = command->argv; *p; a++, p++) {
3345 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3347 free_strings(command->argv);
3348 command->argv = NULL;
3350 /* not "else if": on syntax error, we may have both! */
3351 if (command->group) {
3352 debug_printf_clean(" begin group (cmd_type:%d)\n",
3354 free_pipe_list(command->group);
3355 debug_printf_clean(" end group\n");
3356 command->group = NULL;
3358 /* else is crucial here.
3359 * If group != NULL, child_func is meaningless */
3360 #if ENABLE_HUSH_FUNCTIONS
3361 else if (command->child_func) {
3362 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3363 command->child_func->parent_cmd = NULL;
3367 free(command->group_as_string);
3368 command->group_as_string = NULL;
3370 for (r = command->redirects; r; r = rnext) {
3371 debug_printf_clean(" redirect %d%s",
3372 r->rd_fd, redir_table[r->rd_type].descrip);
3373 /* guard against the case >$FOO, where foo is unset or blank */
3374 if (r->rd_filename) {
3375 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3376 free(r->rd_filename);
3377 r->rd_filename = NULL;
3379 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3383 command->redirects = NULL;
3385 free(pi->cmds); /* children are an array, they get freed all at once */
3393 static void free_pipe_list(struct pipe *head)
3395 struct pipe *pi, *next;
3397 for (pi = head; pi; pi = next) {
3399 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
3402 debug_printf_clean("pipe followup code %d\n", pi->followup);
3404 /*pi->next = NULL;*/
3410 static int run_list(struct pipe *pi);
3412 #define parse_stream(pstring, input, end_trigger) \
3413 parse_stream(input, end_trigger)
3415 static struct pipe *parse_stream(char **pstring,
3416 struct in_str *input,
3418 static void parse_and_run_string(const char *s);
3421 static char *find_in_path(const char *arg)
3424 const char *PATH = get_local_var_value("PATH");
3430 const char *end = strchrnul(PATH, ':');
3431 int sz = end - PATH; /* must be int! */
3435 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3437 /* We have xxx::yyyy in $PATH,
3438 * it means "use current dir" */
3441 if (access(ret, F_OK) == 0)
3454 static const struct built_in_command* find_builtin_helper(const char *name,
3455 const struct built_in_command *x,
3456 const struct built_in_command *end)
3459 if (strcmp(name, x->b_cmd) != 0) {
3463 debug_printf_exec("found builtin '%s'\n", name);
3468 static const struct built_in_command* find_builtin1(const char *name)
3470 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3472 static const struct built_in_command* find_builtin(const char *name)
3474 const struct built_in_command *x = find_builtin1(name);
3477 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3480 #if ENABLE_HUSH_FUNCTIONS
3481 static struct function **find_function_slot(const char *name)
3483 struct function **funcpp = &G.top_func;
3485 if (strcmp(name, (*funcpp)->name) == 0) {
3488 funcpp = &(*funcpp)->next;
3493 static const struct function *find_function(const char *name)
3495 const struct function *funcp = *find_function_slot(name);
3497 debug_printf_exec("found function '%s'\n", name);
3501 /* Note: takes ownership on name ptr */
3502 static struct function *new_function(char *name)
3504 struct function **funcpp = find_function_slot(name);
3505 struct function *funcp = *funcpp;
3507 if (funcp != NULL) {
3508 struct command *cmd = funcp->parent_cmd;
3509 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3511 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3513 /* Note: if !funcp->body, do not free body_as_string!
3514 * This is a special case of "-F name body" function:
3515 * body_as_string was not malloced! */
3517 free_pipe_list(funcp->body);
3519 free(funcp->body_as_string);
3523 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3524 cmd->argv[0] = funcp->name;
3525 cmd->group = funcp->body;
3527 cmd->group_as_string = funcp->body_as_string;
3531 debug_printf_exec("remembering new function '%s'\n", name);
3532 funcp = *funcpp = xzalloc(sizeof(*funcp));
3533 /*funcp->next = NULL;*/
3540 static void unset_func(const char *name)
3542 struct function **funcpp = find_function_slot(name);
3543 struct function *funcp = *funcpp;
3545 if (funcp != NULL) {
3546 debug_printf_exec("freeing function '%s'\n", funcp->name);
3547 *funcpp = funcp->next;
3548 /* funcp is unlinked now, deleting it.
3549 * Note: if !funcp->body, the function was created by
3550 * "-F name body", do not free ->body_as_string
3551 * and ->name as they were not malloced. */
3553 free_pipe_list(funcp->body);
3556 free(funcp->body_as_string);
3564 #define exec_function(to_free, funcp, argv) \
3565 exec_function(funcp, argv)
3567 static void exec_function(char ***to_free,
3568 const struct function *funcp,
3569 char **argv) NORETURN;
3570 static void exec_function(char ***to_free,
3571 const struct function *funcp,
3577 argv[0] = G.global_argv[0];
3578 G.global_argv = argv;
3582 /* On MMU, funcp->body is always non-NULL */
3583 n = run_list(funcp->body);
3587 re_execute_shell(to_free,
3588 funcp->body_as_string,
3595 static int run_function(const struct function *funcp, char **argv)
3601 save_and_replace_G_args(&sv, argv);
3603 /* "we are in function, ok to use return" */
3604 sv_flg = G.flag_return_in_progress;
3605 G.flag_return_in_progress = -1;
3606 # if ENABLE_HUSH_LOCAL
3607 G.func_nest_level++;
3610 /* On MMU, funcp->body is always non-NULL */
3613 /* Function defined by -F */
3614 parse_and_run_string(funcp->body_as_string);
3615 rc = G.last_exitcode;
3619 rc = run_list(funcp->body);
3622 # if ENABLE_HUSH_LOCAL
3624 struct variable *var;
3625 struct variable **var_pp;
3627 var_pp = &G.top_var;
3628 while ((var = *var_pp) != NULL) {
3629 if (var->func_nest_level < G.func_nest_level) {
3630 var_pp = &var->next;
3634 if (var->flg_export)
3635 bb_unsetenv(var->varstr);
3636 /* Remove from global list */
3637 *var_pp = var->next;
3643 G.func_nest_level--;
3646 G.flag_return_in_progress = sv_flg;
3648 restore_G_args(&sv, argv);
3652 #endif /* ENABLE_HUSH_FUNCTIONS */
3656 #define exec_builtin(to_free, x, argv) \
3657 exec_builtin(x, argv)
3659 #define exec_builtin(to_free, x, argv) \
3660 exec_builtin(to_free, argv)
3662 static void exec_builtin(char ***to_free,
3663 const struct built_in_command *x,
3664 char **argv) NORETURN;
3665 static void exec_builtin(char ***to_free,
3666 const struct built_in_command *x,
3670 int rcode = x->b_function(argv);
3674 /* On NOMMU, we must never block!
3675 * Example: { sleep 99 | read line; } & echo Ok
3677 re_execute_shell(to_free,
3686 static void execvp_or_die(char **argv) NORETURN;
3687 static void execvp_or_die(char **argv)
3689 debug_printf_exec("execing '%s'\n", argv[0]);
3690 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3691 execvp(argv[0], argv);
3692 bb_perror_msg("can't execute '%s'", argv[0]);
3693 _exit(127); /* bash compat */
3697 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3698 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3699 #define pseudo_exec(nommu_save, command, argv_expanded) \
3700 pseudo_exec(command, argv_expanded)
3703 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3705 * Don't exit() here. If you don't exec, use _exit instead.
3706 * The at_exit handlers apparently confuse the calling process,
3707 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3708 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3709 char **argv, int assignment_cnt,
3710 char **argv_expanded) NORETURN;
3711 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
3712 char **argv, int assignment_cnt,
3713 char **argv_expanded)
3717 /* Case when we are here: ... | var=val | ... */
3718 if (!argv[assignment_cnt])
3719 _exit(EXIT_SUCCESS);
3721 new_env = expand_assignments(argv, assignment_cnt);
3723 set_vars_and_save_old(new_env);
3724 free(new_env); /* optional */
3725 /* we can also destroy set_vars_and_save_old's return value,
3728 nommu_save->new_env = new_env;
3729 nommu_save->old_vars = set_vars_and_save_old(new_env);
3731 if (argv_expanded) {
3732 argv = argv_expanded;
3734 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3736 nommu_save->argv = argv;
3740 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3741 if (strchr(argv[0], '/') != NULL)
3745 /* Check if the command matches any of the builtins.
3746 * Depending on context, this might be redundant. But it's
3747 * easier to waste a few CPU cycles than it is to figure out
3748 * if this is one of those cases.
3751 /* On NOMMU, it is more expensive to re-execute shell
3752 * just in order to run echo or test builtin.
3753 * It's better to skip it here and run corresponding
3754 * non-builtin later. */
3755 const struct built_in_command *x;
3756 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3758 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3761 #if ENABLE_HUSH_FUNCTIONS
3762 /* Check if the command matches any functions */
3764 const struct function *funcp = find_function(argv[0]);
3766 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3771 #if ENABLE_FEATURE_SH_STANDALONE
3772 /* Check if the command matches any busybox applets */
3774 int a = find_applet_by_name(argv[0]);
3776 # if BB_MMU /* see above why on NOMMU it is not allowed */
3777 if (APPLET_IS_NOEXEC(a)) {
3778 debug_printf_exec("running applet '%s'\n", argv[0]);
3779 run_applet_no_and_exit(a, argv);
3782 /* Re-exec ourselves */
3783 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3784 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3785 execv(bb_busybox_exec_path, argv);
3786 /* If they called chroot or otherwise made the binary no longer
3787 * executable, fall through */
3792 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3795 execvp_or_die(argv);
3798 /* Called after [v]fork() in run_pipe
3800 static void pseudo_exec(nommu_save_t *nommu_save,
3801 struct command *command,
3802 char **argv_expanded) NORETURN;
3803 static void pseudo_exec(nommu_save_t *nommu_save,
3804 struct command *command,
3805 char **argv_expanded)
3807 if (command->argv) {
3808 pseudo_exec_argv(nommu_save, command->argv,
3809 command->assignment_cnt, argv_expanded);
3812 if (command->group) {
3813 /* Cases when we are here:
3816 * ... | ( list ) | ...
3817 * ... | { list } | ...
3821 debug_printf_exec("pseudo_exec: run_list\n");
3822 reset_traps_to_defaults();
3823 rcode = run_list(command->group);
3824 /* OK to leak memory by not calling free_pipe_list,
3825 * since this process is about to exit */
3828 re_execute_shell(&nommu_save->argv_from_re_execing,
3829 command->group_as_string,
3836 /* Case when we are here: ... | >file */
3837 debug_printf_exec("pseudo_exec'ed null command\n");
3838 _exit(EXIT_SUCCESS);
3842 static const char *get_cmdtext(struct pipe *pi)
3848 /* This is subtle. ->cmdtext is created only on first backgrounding.
3849 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3850 * On subsequent bg argv is trashed, but we won't use it */
3853 argv = pi->cmds[0].argv;
3854 if (!argv || !argv[0]) {
3855 pi->cmdtext = xzalloc(1);
3861 len += strlen(*argv) + 1;
3865 argv = pi->cmds[0].argv;
3867 len = strlen(*argv);
3868 memcpy(p, *argv, len);
3876 static void insert_bg_job(struct pipe *pi)
3878 struct pipe *job, **jobp;
3881 /* Linear search for the ID of the job to use */
3883 for (job = G.job_list; job; job = job->next)
3884 if (job->jobid >= pi->jobid)
3885 pi->jobid = job->jobid + 1;
3887 /* Add job to the list of running jobs */
3889 while ((job = *jobp) != NULL)
3891 job = *jobp = xmalloc(sizeof(*job));
3893 *job = *pi; /* physical copy */
3895 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3896 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3897 for (i = 0; i < pi->num_cmds; i++) {
3898 job->cmds[i].pid = pi->cmds[i].pid;
3899 /* all other fields are not used and stay zero */
3901 job->cmdtext = xstrdup(get_cmdtext(pi));
3903 if (G_interactive_fd)
3904 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3905 /* Last command's pid goes to $! */
3906 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3907 G.last_jobid = job->jobid;
3910 static void remove_bg_job(struct pipe *pi)
3912 struct pipe *prev_pipe;
3914 if (pi == G.job_list) {
3915 G.job_list = pi->next;
3917 prev_pipe = G.job_list;
3918 while (prev_pipe->next != pi)
3919 prev_pipe = prev_pipe->next;
3920 prev_pipe->next = pi->next;
3923 G.last_jobid = G.job_list->jobid;
3928 /* Remove a backgrounded job */
3929 static void delete_finished_bg_job(struct pipe *pi)
3932 pi->stopped_cmds = 0;
3938 /* Check to see if any processes have exited -- if they
3939 * have, figure out why and see if a job has completed */
3940 static int checkjobs(struct pipe* fg_pipe)
3950 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3952 attributes = WUNTRACED;
3953 if (fg_pipe == NULL)
3954 attributes |= WNOHANG;
3957 #if ENABLE_HUSH_FAST
3958 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3959 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3960 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3961 /* There was neither fork nor SIGCHLD since last waitpid */
3962 /* Avoid doing waitpid syscall if possible */
3963 if (!G.we_have_children) {
3967 if (fg_pipe == NULL) { /* is WNOHANG set? */
3968 /* We have children, but they did not exit
3969 * or stop yet (we saw no SIGCHLD) */
3972 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3976 /* Do we do this right?
3977 * bash-3.00# sleep 20 | false
3979 * [3]+ Stopped sleep 20 | false
3980 * bash-3.00# echo $?
3981 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3982 * [hush 1.14.0: yes we do it right]
3989 #if ENABLE_HUSH_FAST
3990 i = G.count_SIGCHLD;
3992 childpid = waitpid(-1, &status, attributes);
3993 if (childpid <= 0) {
3994 if (childpid && errno != ECHILD)
3995 bb_perror_msg("waitpid");
3996 #if ENABLE_HUSH_FAST
3997 else { /* Until next SIGCHLD, waitpid's are useless */
3998 G.we_have_children = (childpid == 0);
3999 G.handled_SIGCHLD = i;
4000 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4005 dead = WIFEXITED(status) || WIFSIGNALED(status);
4008 if (WIFSTOPPED(status))
4009 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
4010 childpid, WSTOPSIG(status), WEXITSTATUS(status));
4011 if (WIFSIGNALED(status))
4012 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
4013 childpid, WTERMSIG(status), WEXITSTATUS(status));
4014 if (WIFEXITED(status))
4015 debug_printf_jobs("pid %d exited, exitcode %d\n",
4016 childpid, WEXITSTATUS(status));
4018 /* Were we asked to wait for fg pipe? */
4020 for (i = 0; i < fg_pipe->num_cmds; i++) {
4021 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
4022 if (fg_pipe->cmds[i].pid != childpid)
4025 fg_pipe->cmds[i].pid = 0;
4026 fg_pipe->alive_cmds--;
4027 if (i == fg_pipe->num_cmds - 1) {
4028 /* last process gives overall exitstatus */
4029 rcode = WEXITSTATUS(status);
4030 /* bash prints killer signal's name for *last*
4031 * process in pipe (prints just newline for SIGINT).
4032 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
4034 if (WIFSIGNALED(status)) {
4035 int sig = WTERMSIG(status);
4036 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
4037 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
4038 * Maybe we need to use sig | 128? */
4041 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
4044 fg_pipe->cmds[i].is_stopped = 1;
4045 fg_pipe->stopped_cmds++;
4047 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
4048 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
4049 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
4050 /* All processes in fg pipe have exited or stopped */
4051 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
4052 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
4053 * and "killall -STOP cat" */
4054 if (G_interactive_fd) {
4056 if (fg_pipe->alive_cmds)
4057 insert_bg_job(fg_pipe);
4061 if (!fg_pipe->alive_cmds)
4064 /* There are still running processes in the fg pipe */
4065 goto wait_more; /* do waitpid again */
4067 /* it wasnt fg_pipe, look for process in bg pipes */
4071 /* We asked to wait for bg or orphaned children */
4072 /* No need to remember exitcode in this case */
4073 for (pi = G.job_list; pi; pi = pi->next) {
4074 for (i = 0; i < pi->num_cmds; i++) {
4075 if (pi->cmds[i].pid == childpid)
4076 goto found_pi_and_prognum;
4079 /* Happens when shell is used as init process (init=/bin/sh) */
4080 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
4081 continue; /* do waitpid again */
4083 found_pi_and_prognum:
4086 pi->cmds[i].pid = 0;
4088 if (!pi->alive_cmds) {
4089 if (G_interactive_fd)
4090 printf(JOB_STATUS_FORMAT, pi->jobid,
4091 "Done", pi->cmdtext);
4092 delete_finished_bg_job(pi);
4096 pi->cmds[i].is_stopped = 1;
4100 } /* while (waitpid succeeds)... */
4106 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
4109 int rcode = checkjobs(fg_pipe);
4110 if (G_saved_tty_pgrp) {
4111 /* Job finished, move the shell to the foreground */
4112 p = getpgrp(); /* our process group id */
4113 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
4114 tcsetpgrp(G_interactive_fd, p);
4120 /* Start all the jobs, but don't wait for anything to finish.
4123 * Return code is normally -1, when the caller has to wait for children
4124 * to finish to determine the exit status of the pipe. If the pipe
4125 * is a simple builtin command, however, the action is done by the
4126 * time run_pipe returns, and the exit code is provided as the
4129 * Returns -1 only if started some children. IOW: we have to
4130 * mask out retvals of builtins etc with 0xff!
4132 * The only case when we do not need to [v]fork is when the pipe
4133 * is single, non-backgrounded, non-subshell command. Examples:
4134 * cmd ; ... { list } ; ...
4135 * cmd && ... { list } && ...
4136 * cmd || ... { list } || ...
4137 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
4138 * or (if SH_STANDALONE) an applet, and we can run the { list }
4139 * with run_list. If it isn't one of these, we fork and exec cmd.
4141 * Cases when we must fork:
4142 * non-single: cmd | cmd
4143 * backgrounded: cmd & { list } &
4144 * subshell: ( list ) [&]
4146 static NOINLINE int run_pipe(struct pipe *pi)
4148 static const char *const null_ptr = NULL;
4151 struct command *command;
4152 char **argv_expanded;
4155 /* it is not always needed, but we aim to smaller code */
4156 int squirrel[] = { -1, -1, -1 };
4159 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
4162 IF_HUSH_JOB(pi->pgrp = -1;)
4163 pi->stopped_cmds = 0;
4164 command = &(pi->cmds[0]);
4165 argv_expanded = NULL;
4167 if (pi->num_cmds != 1
4168 || pi->followup == PIPE_BG
4169 || command->cmd_type == CMD_SUBSHELL
4176 debug_printf_exec(": group:%p argv:'%s'\n",
4177 command->group, command->argv ? command->argv[0] : "NONE");
4179 if (command->group) {
4180 #if ENABLE_HUSH_FUNCTIONS
4181 if (command->cmd_type == CMD_FUNCDEF) {
4182 /* "executing" func () { list } */
4183 struct function *funcp;
4185 funcp = new_function(command->argv[0]);
4186 /* funcp->name is already set to argv[0] */
4187 funcp->body = command->group;
4189 funcp->body_as_string = command->group_as_string;
4190 command->group_as_string = NULL;
4192 command->group = NULL;
4193 command->argv[0] = NULL;
4194 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
4195 funcp->parent_cmd = command;
4196 command->child_func = funcp;
4198 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
4200 return EXIT_SUCCESS;
4204 debug_printf("non-subshell group\n");
4205 rcode = 1; /* exitcode if redir failed */
4206 if (setup_redirects(command, squirrel) == 0) {
4207 debug_printf_exec(": run_list\n");
4208 rcode = run_list(command->group) & 0xff;
4210 restore_redirects(squirrel);
4211 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4213 debug_printf_exec("run_pipe: return %d\n", rcode);
4217 argv = command->argv ? command->argv : (char **) &null_ptr;
4219 const struct built_in_command *x;
4220 #if ENABLE_HUSH_FUNCTIONS
4221 const struct function *funcp;
4225 char **new_env = NULL;
4226 struct variable *old_vars = NULL;
4228 if (argv[command->assignment_cnt] == NULL) {
4229 /* Assignments, but no command */
4230 /* Ensure redirects take effect (that is, create files).
4231 * Try "a=t >file": */
4232 rcode = setup_redirects(command, squirrel);
4233 restore_redirects(squirrel);
4234 /* Set shell variables */
4236 p = expand_string_to_string(*argv);
4237 debug_printf_exec("set shell var:'%s'->'%s'\n",
4239 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4242 /* Redirect error sets $? to 1. Othervise,
4243 * if evaluating assignment value set $?, retain it.
4244 * Try "false; q=`exit 2`; echo $?" - should print 2: */
4246 rcode = G.last_exitcode;
4247 /* Do we need to flag set_local_var() errors?
4248 * "assignment to readonly var" and "putenv error"
4250 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4252 debug_printf_exec("run_pipe: return %d\n", rcode);
4256 /* Expand the rest into (possibly) many strings each */
4258 #if ENABLE_HUSH_BASH_COMPAT
4259 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
4260 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
4263 #ifdef CMD_SINGLEWORD_NOGLOB_COND
4264 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
4265 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
4270 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
4273 /* if someone gives us an empty string: `cmd with empty output` */
4274 if (!argv_expanded[0]) {
4275 free(argv_expanded);
4277 return G.last_exitcode;
4280 x = find_builtin(argv_expanded[0]);
4281 #if ENABLE_HUSH_FUNCTIONS
4284 funcp = find_function(argv_expanded[0]);
4288 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
4289 debug_printf("exec with redirects only\n");
4290 rcode = setup_redirects(command, NULL);
4291 goto clean_up_and_ret1;
4294 /* setup_redirects acts on file descriptors, not FILEs.
4295 * This is perfect for work that comes after exec().
4296 * Is it really safe for inline use? Experimentally,
4297 * things seem to work. */
4298 rcode = setup_redirects(command, squirrel);
4300 new_env = expand_assignments(argv, command->assignment_cnt);
4301 old_vars = set_vars_and_save_old(new_env);
4303 debug_printf_exec(": builtin '%s' '%s'...\n",
4304 x->b_cmd, argv_expanded[1]);
4305 rcode = x->b_function(argv_expanded) & 0xff;
4308 #if ENABLE_HUSH_FUNCTIONS
4310 # if ENABLE_HUSH_LOCAL
4311 struct variable **sv;
4312 sv = G.shadowed_vars_pp;
4313 G.shadowed_vars_pp = &old_vars;
4315 debug_printf_exec(": function '%s' '%s'...\n",
4316 funcp->name, argv_expanded[1]);
4317 rcode = run_function(funcp, argv_expanded) & 0xff;
4318 # if ENABLE_HUSH_LOCAL
4319 G.shadowed_vars_pp = sv;
4324 #if ENABLE_FEATURE_SH_STANDALONE
4327 restore_redirects(squirrel);
4328 unset_vars(new_env);
4331 free(argv_expanded);
4332 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
4334 debug_printf_exec("run_pipe return %d\n", rcode);
4338 #if ENABLE_FEATURE_SH_STANDALONE
4339 i = find_applet_by_name(argv_expanded[0]);
4340 if (i >= 0 && APPLET_IS_NOFORK(i)) {
4341 rcode = setup_redirects(command, squirrel);
4343 new_env = expand_assignments(argv, command->assignment_cnt);
4344 old_vars = set_vars_and_save_old(new_env);
4345 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
4346 argv_expanded[0], argv_expanded[1]);
4347 rcode = run_nofork_applet(i, argv_expanded);
4349 goto clean_up_and_ret;
4352 /* It is neither builtin nor applet. We must fork. */
4356 /* NB: argv_expanded may already be created, and that
4357 * might include `cmd` runs! Do not rerun it! We *must*
4358 * use argv_expanded if it's non-NULL */
4360 /* Going to fork a child per each pipe member */
4364 for (i = 0; i < pi->num_cmds; i++) {
4365 struct fd_pair pipefds;
4367 volatile nommu_save_t nommu_save;
4368 nommu_save.new_env = NULL;
4369 nommu_save.old_vars = NULL;
4370 nommu_save.argv = NULL;
4371 nommu_save.argv_from_re_execing = NULL;
4373 command = &(pi->cmds[i]);
4374 if (command->argv) {
4375 debug_printf_exec(": pipe member '%s' '%s'...\n",
4376 command->argv[0], command->argv[1]);
4378 debug_printf_exec(": pipe member with no argv\n");
4381 /* pipes are inserted between pairs of commands */
4384 if ((i + 1) < pi->num_cmds)
4385 xpiped_pair(pipefds);
4387 command->pid = BB_MMU ? fork() : vfork();
4388 if (!command->pid) { /* child */
4390 disable_restore_tty_pgrp_on_exit();
4391 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
4393 /* Every child adds itself to new process group
4394 * with pgid == pid_of_first_child_in_pipe */
4395 if (G.run_list_level == 1 && G_interactive_fd) {
4398 if (pgrp < 0) /* true for 1st process only */
4400 if (setpgid(0, pgrp) == 0
4401 && pi->followup != PIPE_BG
4402 && G_saved_tty_pgrp /* we have ctty */
4404 /* We do it in *every* child, not just first,
4406 tcsetpgrp(G_interactive_fd, pgrp);
4410 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
4411 /* 1st cmd in backgrounded pipe
4412 * should have its stdin /dev/null'ed */
4414 if (open(bb_dev_null, O_RDONLY))
4415 xopen("/", O_RDONLY);
4417 xmove_fd(nextin, 0);
4419 xmove_fd(pipefds.wr, 1);
4422 /* Like bash, explicit redirects override pipes,
4423 * and the pipe fd is available for dup'ing. */
4424 if (setup_redirects(command, NULL))
4427 /* Restore default handlers just prior to exec */
4428 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4430 /* Stores to nommu_save list of env vars putenv'ed
4431 * (NOMMU, on MMU we don't need that) */
4432 /* cast away volatility... */
4433 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4434 /* pseudo_exec() does not return */
4437 /* parent or error */
4438 #if ENABLE_HUSH_FAST
4440 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4442 enable_restore_tty_pgrp_on_exit();
4444 /* Clean up after vforked child */
4445 free(nommu_save.argv);
4446 free(nommu_save.argv_from_re_execing);
4447 unset_vars(nommu_save.new_env);
4448 add_vars(nommu_save.old_vars);
4450 free(argv_expanded);
4451 argv_expanded = NULL;
4452 if (command->pid < 0) { /* [v]fork failed */
4453 /* Clearly indicate, was it fork or vfork */
4454 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4458 /* Second and next children need to know pid of first one */
4460 pi->pgrp = command->pid;
4466 if ((i + 1) < pi->num_cmds)
4468 /* Pass read (output) pipe end to next iteration */
4469 nextin = pipefds.rd;
4472 if (!pi->alive_cmds) {
4474 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4479 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4483 #ifndef debug_print_tree
4484 static void debug_print_tree(struct pipe *pi, int lvl)
4486 static const char *const PIPE[] = {
4492 static const char *RES[] = {
4493 [RES_NONE ] = "NONE" ,
4496 [RES_THEN ] = "THEN" ,
4497 [RES_ELIF ] = "ELIF" ,
4498 [RES_ELSE ] = "ELSE" ,
4501 # if ENABLE_HUSH_LOOPS
4502 [RES_FOR ] = "FOR" ,
4503 [RES_WHILE] = "WHILE",
4504 [RES_UNTIL] = "UNTIL",
4506 [RES_DONE ] = "DONE" ,
4508 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4511 # if ENABLE_HUSH_CASE
4512 [RES_CASE ] = "CASE" ,
4513 [RES_CASE_IN ] = "CASE_IN" ,
4514 [RES_MATCH] = "MATCH",
4515 [RES_CASE_BODY] = "CASE_BODY",
4516 [RES_ESAC ] = "ESAC" ,
4518 [RES_XXXX ] = "XXXX" ,
4519 [RES_SNTX ] = "SNTX" ,
4521 static const char *const CMDTYPE[] = {
4525 # if ENABLE_HUSH_FUNCTIONS
4534 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4535 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4537 while (prn < pi->num_cmds) {
4538 struct command *command = &pi->cmds[prn];
4539 char **argv = command->argv;
4541 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4543 command->assignment_cnt);
4544 if (command->group) {
4545 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
4546 CMDTYPE[command->cmd_type],
4549 , " group_as_string:", command->group_as_string
4554 debug_print_tree(command->group, lvl+1);
4558 if (argv) while (*argv) {
4559 fprintf(stderr, " '%s'", *argv);
4562 fprintf(stderr, "\n");
4569 #endif /* debug_print_tree */
4571 /* NB: called by pseudo_exec, and therefore must not modify any
4572 * global data until exec/_exit (we can be a child after vfork!) */
4573 static int run_list(struct pipe *pi)
4575 #if ENABLE_HUSH_CASE
4576 char *case_word = NULL;
4578 #if ENABLE_HUSH_LOOPS
4579 struct pipe *loop_top = NULL;
4580 char **for_lcur = NULL;
4581 char **for_list = NULL;
4583 smallint last_followup;
4585 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4586 smalluint cond_code = 0;
4588 enum { cond_code = 0 };
4591 smallint rword; /* enum reserved_style */
4592 smallint last_rword; /* ditto */
4595 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4598 #if ENABLE_HUSH_LOOPS
4599 /* Check syntax for "for" */
4600 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4601 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4603 /* current word is FOR or IN (BOLD in comments below) */
4604 if (cpipe->next == NULL) {
4605 syntax_error("malformed for");
4607 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4610 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4611 if (cpipe->next->res_word == RES_DO)
4613 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4614 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4615 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4617 syntax_error("malformed for");
4619 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4625 /* Past this point, all code paths should jump to ret: label
4626 * in order to return, no direct "return" statements please.
4627 * This helps to ensure that no memory is leaked. */
4635 last_rword = RES_XXXX;
4637 last_followup = PIPE_SEQ;
4638 rcode = G.last_exitcode;
4640 /* Go through list of pipes, (maybe) executing them. */
4641 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4645 IF_HAS_KEYWORDS(rword = pi->res_word;)
4646 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4647 rword, cond_code, last_rword);
4648 #if ENABLE_HUSH_LOOPS
4649 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4650 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4652 /* start of a loop: remember where loop starts */
4657 /* Still in the same "if...", "then..." or "do..." branch? */
4658 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4659 if ((rcode == 0 && last_followup == PIPE_OR)
4660 || (rcode != 0 && last_followup == PIPE_AND)
4662 /* It is "<true> || CMD" or "<false> && CMD"
4663 * and we should not execute CMD */
4664 debug_printf_exec("skipped cmd because of || or &&\n");
4665 last_followup = pi->followup;
4669 last_followup = pi->followup;
4670 IF_HAS_KEYWORDS(last_rword = rword;)
4673 if (rword == RES_THEN) {
4674 /* if false; then ... fi has exitcode 0! */
4675 G.last_exitcode = rcode = EXIT_SUCCESS;
4676 /* "if <false> THEN cmd": skip cmd */
4680 if (rword == RES_ELSE || rword == RES_ELIF) {
4681 /* "if <true> then ... ELSE/ELIF cmd":
4682 * skip cmd and all following ones */
4687 #if ENABLE_HUSH_LOOPS
4688 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4690 /* first loop through for */
4692 static const char encoded_dollar_at[] ALIGN1 = {
4693 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4694 }; /* encoded representation of "$@" */
4695 static const char *const encoded_dollar_at_argv[] = {
4696 encoded_dollar_at, NULL
4697 }; /* argv list with one element: "$@" */
4700 vals = (char**)encoded_dollar_at_argv;
4701 if (pi->next->res_word == RES_IN) {
4702 /* if no variable values after "in" we skip "for" */
4703 if (!pi->next->cmds[0].argv) {
4704 G.last_exitcode = rcode = EXIT_SUCCESS;
4705 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4708 vals = pi->next->cmds[0].argv;
4709 } /* else: "for var; do..." -> assume "$@" list */
4710 /* create list of variable values */
4711 debug_print_strings("for_list made from", vals);
4712 for_list = expand_strvec_to_strvec(vals);
4713 for_lcur = for_list;
4714 debug_print_strings("for_list", for_list);
4717 /* "for" loop is over, clean up */
4723 /* Insert next value from for_lcur */
4724 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4725 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4728 if (rword == RES_IN) {
4729 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4731 if (rword == RES_DONE) {
4732 continue; /* "done" has no cmds too */
4735 #if ENABLE_HUSH_CASE
4736 if (rword == RES_CASE) {
4737 case_word = expand_strvec_to_string(pi->cmds->argv);
4740 if (rword == RES_MATCH) {
4743 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4745 /* all prev words didn't match, does this one match? */
4746 argv = pi->cmds->argv;
4748 char *pattern = expand_string_to_string(*argv);
4749 /* TODO: which FNM_xxx flags to use? */
4750 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4752 if (cond_code == 0) { /* match! we will execute this branch */
4753 free(case_word); /* make future "word)" stop */
4761 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4763 continue; /* not matched yet, skip this pipe */
4766 /* Just pressing <enter> in shell should check for jobs.
4767 * OTOH, in non-interactive shell this is useless
4768 * and only leads to extra job checks */
4769 if (pi->num_cmds == 0) {
4770 if (G_interactive_fd)
4771 goto check_jobs_and_continue;
4775 /* After analyzing all keywords and conditions, we decided
4776 * to execute this pipe. NB: have to do checkjobs(NULL)
4777 * after run_pipe to collect any background children,
4778 * even if list execution is to be stopped. */
4779 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4782 #if ENABLE_HUSH_LOOPS
4783 G.flag_break_continue = 0;
4785 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4787 /* We ran a builtin, function, or group.
4788 * rcode is already known
4789 * and we don't need to wait for anything. */
4790 G.last_exitcode = rcode;
4791 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4792 check_and_run_traps(0);
4793 #if ENABLE_HUSH_LOOPS
4794 /* Was it "break" or "continue"? */
4795 if (G.flag_break_continue) {
4796 smallint fbc = G.flag_break_continue;
4797 /* We might fall into outer *loop*,
4798 * don't want to break it too */
4800 G.depth_break_continue--;
4801 if (G.depth_break_continue == 0)
4802 G.flag_break_continue = 0;
4803 /* else: e.g. "continue 2" should *break* once, *then* continue */
4804 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4805 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4806 goto check_jobs_and_break;
4807 /* "continue": simulate end of loop */
4812 #if ENABLE_HUSH_FUNCTIONS
4813 if (G.flag_return_in_progress == 1) {
4814 /* same as "goto check_jobs_and_break" */
4819 } else if (pi->followup == PIPE_BG) {
4820 /* What does bash do with attempts to background builtins? */
4821 /* even bash 3.2 doesn't do that well with nested bg:
4822 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4823 * I'm NOT treating inner &'s as jobs */
4824 check_and_run_traps(0);
4826 if (G.run_list_level == 1)
4829 G.last_exitcode = rcode = EXIT_SUCCESS;
4830 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4833 if (G.run_list_level == 1 && G_interactive_fd) {
4834 /* Waits for completion, then fg's main shell */
4835 rcode = checkjobs_and_fg_shell(pi);
4836 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4837 check_and_run_traps(0);
4840 { /* This one just waits for completion */
4841 rcode = checkjobs(pi);
4842 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4843 check_and_run_traps(0);
4845 G.last_exitcode = rcode;
4849 /* Analyze how result affects subsequent commands */
4851 if (rword == RES_IF || rword == RES_ELIF)
4854 #if ENABLE_HUSH_LOOPS
4855 /* Beware of "while false; true; do ..."! */
4856 if (pi->next && pi->next->res_word == RES_DO) {
4857 if (rword == RES_WHILE) {
4859 /* "while false; do...done" - exitcode 0 */
4860 G.last_exitcode = rcode = EXIT_SUCCESS;
4861 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4862 goto check_jobs_and_break;
4865 if (rword == RES_UNTIL) {
4867 debug_printf_exec(": until expr is true: breaking\n");
4868 check_jobs_and_break:
4876 check_jobs_and_continue:
4883 #if ENABLE_HUSH_LOOPS
4888 #if ENABLE_HUSH_CASE
4892 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4896 /* Select which version we will use */
4897 static int run_and_free_list(struct pipe *pi)
4900 debug_printf_exec("run_and_free_list entered\n");
4902 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4903 rcode = run_list(pi);
4905 /* free_pipe_list has the side effect of clearing memory.
4906 * In the long run that function can be merged with run_list,
4907 * but doing that now would hobble the debugging effort. */
4909 debug_printf_exec("run_and_free_list return %d\n", rcode);
4914 static struct pipe *new_pipe(void)
4917 pi = xzalloc(sizeof(struct pipe));
4918 /*pi->followup = 0; - deliberately invalid value */
4919 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4923 /* Command (member of a pipe) is complete, or we start a new pipe
4924 * if ctx->command is NULL.
4925 * No errors possible here.
4927 static int done_command(struct parse_context *ctx)
4929 /* The command is really already in the pipe structure, so
4930 * advance the pipe counter and make a new, null command. */
4931 struct pipe *pi = ctx->pipe;
4932 struct command *command = ctx->command;
4935 if (IS_NULL_CMD(command)) {
4936 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4940 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4941 //debug_print_tree(ctx->list_head, 20);
4943 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4946 /* Only real trickiness here is that the uncommitted
4947 * command structure is not counted in pi->num_cmds. */
4948 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4949 ctx->command = command = &pi->cmds[pi->num_cmds];
4951 memset(command, 0, sizeof(*command));
4952 return pi->num_cmds; /* used only for 0/nonzero check */
4955 static void done_pipe(struct parse_context *ctx, pipe_style type)
4959 debug_printf_parse("done_pipe entered, followup %d\n", type);
4960 /* Close previous command */
4961 not_null = done_command(ctx);
4962 ctx->pipe->followup = type;
4964 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4965 ctx->ctx_inverted = 0;
4966 ctx->pipe->res_word = ctx->ctx_res_w;
4969 /* Without this check, even just <enter> on command line generates
4970 * tree of three NOPs (!). Which is harmless but annoying.
4971 * IOW: it is safe to do it unconditionally. */
4974 || ctx->ctx_res_w == RES_FI
4976 #if ENABLE_HUSH_LOOPS
4977 || ctx->ctx_res_w == RES_DONE
4978 || ctx->ctx_res_w == RES_FOR
4979 || ctx->ctx_res_w == RES_IN
4981 #if ENABLE_HUSH_CASE
4982 || ctx->ctx_res_w == RES_ESAC
4986 debug_printf_parse("done_pipe: adding new pipe: "
4987 "not_null:%d ctx->ctx_res_w:%d\n",
4988 not_null, ctx->ctx_res_w);
4990 ctx->pipe->next = new_p;
4992 /* RES_THEN, RES_DO etc are "sticky" -
4993 * they remain set for pipes inside if/while.
4994 * This is used to control execution.
4995 * RES_FOR and RES_IN are NOT sticky (needed to support
4996 * cases where variable or value happens to match a keyword):
4998 #if ENABLE_HUSH_LOOPS
4999 if (ctx->ctx_res_w == RES_FOR
5000 || ctx->ctx_res_w == RES_IN)
5001 ctx->ctx_res_w = RES_NONE;
5003 #if ENABLE_HUSH_CASE
5004 if (ctx->ctx_res_w == RES_MATCH)
5005 ctx->ctx_res_w = RES_CASE_BODY;
5006 if (ctx->ctx_res_w == RES_CASE)
5007 ctx->ctx_res_w = RES_CASE_IN;
5009 ctx->command = NULL; /* trick done_command below */
5010 /* Create the memory for command, roughly:
5011 * ctx->pipe->cmds = new struct command;
5012 * ctx->command = &ctx->pipe->cmds[0];
5015 //debug_print_tree(ctx->list_head, 10);
5017 debug_printf_parse("done_pipe return\n");
5020 static void initialize_context(struct parse_context *ctx)
5022 memset(ctx, 0, sizeof(*ctx));
5023 ctx->pipe = ctx->list_head = new_pipe();
5024 /* Create the memory for command, roughly:
5025 * ctx->pipe->cmds = new struct command;
5026 * ctx->command = &ctx->pipe->cmds[0];
5031 /* If a reserved word is found and processed, parse context is modified
5032 * and 1 is returned.
5035 struct reserved_combo {
5038 unsigned char assignment_flag;
5042 FLAG_END = (1 << RES_NONE ),
5044 FLAG_IF = (1 << RES_IF ),
5045 FLAG_THEN = (1 << RES_THEN ),
5046 FLAG_ELIF = (1 << RES_ELIF ),
5047 FLAG_ELSE = (1 << RES_ELSE ),
5048 FLAG_FI = (1 << RES_FI ),
5050 # if ENABLE_HUSH_LOOPS
5051 FLAG_FOR = (1 << RES_FOR ),
5052 FLAG_WHILE = (1 << RES_WHILE),
5053 FLAG_UNTIL = (1 << RES_UNTIL),
5054 FLAG_DO = (1 << RES_DO ),
5055 FLAG_DONE = (1 << RES_DONE ),
5056 FLAG_IN = (1 << RES_IN ),
5058 # if ENABLE_HUSH_CASE
5059 FLAG_MATCH = (1 << RES_MATCH),
5060 FLAG_ESAC = (1 << RES_ESAC ),
5062 FLAG_START = (1 << RES_XXXX ),
5065 static const struct reserved_combo* match_reserved_word(o_string *word)
5067 /* Mostly a list of accepted follow-up reserved words.
5068 * FLAG_END means we are done with the sequence, and are ready
5069 * to turn the compound list into a command.
5070 * FLAG_START means the word must start a new compound list.
5072 static const struct reserved_combo reserved_list[] = {
5074 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
5075 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
5076 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
5077 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
5078 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
5079 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
5081 # if ENABLE_HUSH_LOOPS
5082 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
5083 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5084 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
5085 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
5086 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
5087 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
5089 # if ENABLE_HUSH_CASE
5090 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
5091 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
5094 const struct reserved_combo *r;
5096 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
5097 if (strcmp(word->data, r->literal) == 0)
5102 /* Return 0: not a keyword, 1: keyword
5104 static int reserved_word(o_string *word, struct parse_context *ctx)
5106 # if ENABLE_HUSH_CASE
5107 static const struct reserved_combo reserved_match = {
5108 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
5111 const struct reserved_combo *r;
5115 r = match_reserved_word(word);
5119 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
5120 # if ENABLE_HUSH_CASE
5121 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
5122 /* "case word IN ..." - IN part starts first MATCH part */
5123 r = &reserved_match;
5126 if (r->flag == 0) { /* '!' */
5127 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
5128 syntax_error("! ! command");
5129 ctx->ctx_res_w = RES_SNTX;
5131 ctx->ctx_inverted = 1;
5134 if (r->flag & FLAG_START) {
5135 struct parse_context *old;
5137 old = xmalloc(sizeof(*old));
5138 debug_printf_parse("push stack %p\n", old);
5139 *old = *ctx; /* physical copy */
5140 initialize_context(ctx);
5142 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
5143 syntax_error_at(word->data);
5144 ctx->ctx_res_w = RES_SNTX;
5147 /* "{...} fi" is ok. "{...} if" is not
5149 * if { echo foo; } then { echo bar; } fi */
5150 if (ctx->command->group)
5151 done_pipe(ctx, PIPE_SEQ);
5154 ctx->ctx_res_w = r->res;
5155 ctx->old_flag = r->flag;
5156 word->o_assignment = r->assignment_flag;
5158 if (ctx->old_flag & FLAG_END) {
5159 struct parse_context *old;
5161 done_pipe(ctx, PIPE_SEQ);
5162 debug_printf_parse("pop stack %p\n", ctx->stack);
5164 old->command->group = ctx->list_head;
5165 old->command->cmd_type = CMD_NORMAL;
5167 o_addstr(&old->as_string, ctx->as_string.data);
5168 o_free_unsafe(&ctx->as_string);
5169 old->command->group_as_string = xstrdup(old->as_string.data);
5170 debug_printf_parse("pop, remembering as:'%s'\n",
5171 old->command->group_as_string);
5173 *ctx = *old; /* physical copy */
5178 #endif /* HAS_KEYWORDS */
5180 /* Word is complete, look at it and update parsing context.
5181 * Normal return is 0. Syntax errors return 1.
5182 * Note: on return, word is reset, but not o_free'd!
5184 static int done_word(o_string *word, struct parse_context *ctx)
5186 struct command *command = ctx->command;
5188 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
5189 if (word->length == 0 && word->o_quoted == 0) {
5190 debug_printf_parse("done_word return 0: true null, ignored\n");
5194 if (ctx->pending_redirect) {
5195 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
5196 * only if run as "bash", not "sh" */
5197 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5199 * ...the word that follows the redirection operator
5200 * shall be subjected to tilde expansion, parameter expansion,
5201 * command substitution, arithmetic expansion, and quote
5202 * removal. Pathname expansion shall not be performed
5203 * on the word by a non-interactive shell; an interactive
5204 * shell may perform it, but shall do so only when
5205 * the expansion would result in one word."
5207 ctx->pending_redirect->rd_filename = xstrdup(word->data);
5208 /* Cater for >\file case:
5209 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
5210 * Same with heredocs:
5211 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
5213 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
5214 unbackslash(ctx->pending_redirect->rd_filename);
5215 /* Is it <<"HEREDOC"? */
5216 if (word->o_quoted) {
5217 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
5220 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
5221 ctx->pending_redirect = NULL;
5223 /* If this word wasn't an assignment, next ones definitely
5224 * can't be assignments. Even if they look like ones. */
5225 if (word->o_assignment != DEFINITELY_ASSIGNMENT
5226 && word->o_assignment != WORD_IS_KEYWORD
5228 word->o_assignment = NOT_ASSIGNMENT;
5230 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
5231 command->assignment_cnt++;
5232 word->o_assignment = MAYBE_ASSIGNMENT;
5236 # if ENABLE_HUSH_CASE
5237 if (ctx->ctx_dsemicolon
5238 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
5240 /* already done when ctx_dsemicolon was set to 1: */
5241 /* ctx->ctx_res_w = RES_MATCH; */
5242 ctx->ctx_dsemicolon = 0;
5245 if (!command->argv /* if it's the first word... */
5246 # if ENABLE_HUSH_LOOPS
5247 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
5248 && ctx->ctx_res_w != RES_IN
5250 # if ENABLE_HUSH_CASE
5251 && ctx->ctx_res_w != RES_CASE
5254 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
5255 if (reserved_word(word, ctx)) {
5256 o_reset_to_empty_unquoted(word);
5257 debug_printf_parse("done_word return %d\n",
5258 (ctx->ctx_res_w == RES_SNTX));
5259 return (ctx->ctx_res_w == RES_SNTX);
5261 # ifdef CMD_SINGLEWORD_NOGLOB_COND
5262 if (strcmp(word->data, "export") == 0
5263 # if ENABLE_HUSH_LOCAL
5264 || strcmp(word->data, "local") == 0
5267 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
5270 # if ENABLE_HUSH_BASH_COMPAT
5271 if (strcmp(word->data, "[[") == 0) {
5272 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
5278 if (command->group) {
5279 /* "{ echo foo; } echo bar" - bad */
5280 syntax_error_at(word->data);
5281 debug_printf_parse("done_word return 1: syntax error, "
5282 "groups and arglists don't mix\n");
5285 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
5286 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
5287 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
5288 /* (otherwise it's known to be not empty and is already safe) */
5290 /* exclude "$@" - it can expand to no word despite "" */
5291 char *p = word->data;
5292 while (p[0] == SPECIAL_VAR_SYMBOL
5293 && (p[1] & 0x7f) == '@'
5294 && p[2] == SPECIAL_VAR_SYMBOL
5298 if (p == word->data || p[0] != '\0') {
5299 /* saw no "$@", or not only "$@" but some
5300 * real text is there too */
5301 /* insert "empty variable" reference, this makes
5302 * e.g. "", $empty"" etc to not disappear */
5303 o_addchr(word, SPECIAL_VAR_SYMBOL);
5304 o_addchr(word, SPECIAL_VAR_SYMBOL);
5307 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
5308 debug_print_strings("word appended to argv", command->argv);
5311 #if ENABLE_HUSH_LOOPS
5312 if (ctx->ctx_res_w == RES_FOR) {
5314 || !is_well_formed_var_name(command->argv[0], '\0')
5316 /* bash says just "not a valid identifier" */
5317 syntax_error("not a valid identifier in for");
5320 /* Force FOR to have just one word (variable name) */
5321 /* NB: basically, this makes hush see "for v in ..."
5322 * syntax as if it is "for v; in ...". FOR and IN become
5323 * two pipe structs in parse tree. */
5324 done_pipe(ctx, PIPE_SEQ);
5327 #if ENABLE_HUSH_CASE
5328 /* Force CASE to have just one word */
5329 if (ctx->ctx_res_w == RES_CASE) {
5330 done_pipe(ctx, PIPE_SEQ);
5334 o_reset_to_empty_unquoted(word);
5336 debug_printf_parse("done_word return 0\n");
5341 /* Peek ahead in the input to find out if we have a "&n" construct,
5342 * as in "2>&1", that represents duplicating a file descriptor.
5344 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
5345 * REDIRFD_SYNTAX_ERR if syntax error,
5346 * REDIRFD_TO_FILE if no & was seen,
5347 * or the number found.
5350 #define parse_redir_right_fd(as_string, input) \
5351 parse_redir_right_fd(input)
5353 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
5359 return REDIRFD_TO_FILE;
5361 ch = i_getch(input); /* get the & */
5362 nommu_addchr(as_string, ch);
5365 ch = i_getch(input);
5366 nommu_addchr(as_string, ch);
5367 return REDIRFD_CLOSE;
5371 while (ch != EOF && isdigit(ch)) {
5372 d = d*10 + (ch-'0');
5374 ch = i_getch(input);
5375 nommu_addchr(as_string, ch);
5380 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
5382 bb_error_msg("ambiguous redirect");
5383 return REDIRFD_SYNTAX_ERR;
5386 /* Return code is 0 normal, 1 if a syntax error is detected
5388 static int parse_redirect(struct parse_context *ctx,
5391 struct in_str *input)
5393 struct command *command = ctx->command;
5394 struct redir_struct *redir;
5395 struct redir_struct **redirp;
5398 dup_num = REDIRFD_TO_FILE;
5399 if (style != REDIRECT_HEREDOC) {
5400 /* Check for a '>&1' type redirect */
5401 dup_num = parse_redir_right_fd(&ctx->as_string, input);
5402 if (dup_num == REDIRFD_SYNTAX_ERR)
5405 int ch = i_peek(input);
5406 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
5407 if (dup_num) { /* <<-... */
5408 ch = i_getch(input);
5409 nommu_addchr(&ctx->as_string, ch);
5414 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
5415 int ch = i_peek(input);
5417 /* >|FILE redirect ("clobbering" >).
5418 * Since we do not support "set -o noclobber" yet,
5419 * >| and > are the same for now. Just eat |.
5421 ch = i_getch(input);
5422 nommu_addchr(&ctx->as_string, ch);
5426 /* Create a new redir_struct and append it to the linked list */
5427 redirp = &command->redirects;
5428 while ((redir = *redirp) != NULL) {
5429 redirp = &(redir->next);
5431 *redirp = redir = xzalloc(sizeof(*redir));
5432 /* redir->next = NULL; */
5433 /* redir->rd_filename = NULL; */
5434 redir->rd_type = style;
5435 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5437 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5438 redir_table[style].descrip);
5440 redir->rd_dup = dup_num;
5441 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5442 /* Erik had a check here that the file descriptor in question
5443 * is legit; I postpone that to "run time"
5444 * A "-" representation of "close me" shows up as a -3 here */
5445 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5446 redir->rd_fd, redir->rd_dup);
5448 /* Set ctx->pending_redirect, so we know what to do at the
5449 * end of the next parsed word. */
5450 ctx->pending_redirect = redir;
5455 /* If a redirect is immediately preceded by a number, that number is
5456 * supposed to tell which file descriptor to redirect. This routine
5457 * looks for such preceding numbers. In an ideal world this routine
5458 * needs to handle all the following classes of redirects...
5459 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5460 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5461 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5462 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5464 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5466 * ... If n is quoted, the number shall not be recognized as part of
5467 * the redirection expression. For example:
5469 * writes the character 2 into file a"
5470 * We are getting it right by setting ->o_quoted on any \<char>
5472 * A -1 return means no valid number was found,
5473 * the caller should use the appropriate default for this redirection.
5475 static int redirect_opt_num(o_string *o)
5479 if (o->data == NULL)
5481 num = bb_strtou(o->data, NULL, 10);
5482 if (errno || num < 0)
5484 o_reset_to_empty_unquoted(o);
5489 #define fetch_till_str(as_string, input, word, skip_tabs) \
5490 fetch_till_str(input, word, skip_tabs)
5492 static char *fetch_till_str(o_string *as_string,
5493 struct in_str *input,
5497 o_string heredoc = NULL_O_STRING;
5503 ch = i_getch(input);
5504 nommu_addchr(as_string, ch);
5506 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5507 heredoc.data[past_EOL] = '\0';
5508 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5509 return heredoc.data;
5512 o_addchr(&heredoc, ch);
5513 past_EOL = heredoc.length;
5516 ch = i_getch(input);
5517 nommu_addchr(as_string, ch);
5518 } while (skip_tabs && ch == '\t');
5519 } while (ch == '\n');
5522 o_free_unsafe(&heredoc);
5525 o_addchr(&heredoc, ch);
5526 nommu_addchr(as_string, ch);
5530 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5531 * and load them all. There should be exactly heredoc_cnt of them.
5533 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5535 struct pipe *pi = ctx->list_head;
5537 while (pi && heredoc_cnt) {
5539 struct command *cmd = pi->cmds;
5541 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5543 cmd->argv ? cmd->argv[0] : "NONE");
5544 for (i = 0; i < pi->num_cmds; i++) {
5545 struct redir_struct *redir = cmd->redirects;
5547 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5548 i, cmd->argv ? cmd->argv[0] : "NONE");
5550 if (redir->rd_type == REDIRECT_HEREDOC) {
5553 redir->rd_type = REDIRECT_HEREDOC2;
5554 /* redir->rd_dup is (ab)used to indicate <<- */
5555 p = fetch_till_str(&ctx->as_string, input,
5556 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5558 syntax_error("unexpected EOF in here document");
5561 free(redir->rd_filename);
5562 redir->rd_filename = p;
5565 redir = redir->next;
5572 /* Should be 0. If it isn't, it's a parse error */
5574 bb_error_msg_and_die("heredoc BUG 2");
5580 #if ENABLE_HUSH_TICK
5581 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5586 char **to_free = NULL;
5590 pid = BB_MMU ? fork() : vfork();
5592 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5594 if (pid == 0) { /* child */
5595 disable_restore_tty_pgrp_on_exit();
5596 /* Process substitution is not considered to be usual
5597 * 'command execution'.
5598 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5605 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5606 close(channel[0]); /* NB: close _first_, then move fd! */
5607 xmove_fd(channel[1], 1);
5608 /* Prevent it from trying to handle ctrl-z etc */
5609 IF_HUSH_JOB(G.run_list_level = 1;)
5610 /* Awful hack for `trap` or $(trap).
5612 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5613 * contains an example where "trap" is executed in a subshell:
5615 * save_traps=$(trap)
5617 * eval "$save_traps"
5619 * Standard does not say that "trap" in subshell shall print
5620 * parent shell's traps. It only says that its output
5621 * must have suitable form, but then, in the above example
5622 * (which is not supposed to be normative), it implies that.
5624 * bash (and probably other shell) does implement it
5625 * (traps are reset to defaults, but "trap" still shows them),
5626 * but as a result, "trap" logic is hopelessly messed up:
5629 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5630 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5631 * # true | trap <--- trap is in subshell - no output (ditto)
5632 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5633 * trap -- 'echo Ho' SIGWINCH
5634 * # echo `(trap)` <--- in subshell in subshell - output
5635 * trap -- 'echo Ho' SIGWINCH
5636 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5637 * trap -- 'echo Ho' SIGWINCH
5639 * The rules when to forget and when to not forget traps
5640 * get really complex and nonsensical.
5642 * Our solution: ONLY bare $(trap) or `trap` is special.
5644 s = skip_whitespace(s);
5645 if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
5647 static const char *const argv[] = { NULL, NULL };
5648 builtin_trap((char**)argv);
5649 exit(0); /* not _exit() - we need to fflush */
5652 reset_traps_to_defaults();
5653 parse_and_run_string(s);
5654 _exit(G.last_exitcode);
5656 /* We re-execute after vfork on NOMMU. This makes this script safe:
5657 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5658 * huge=`cat BIG` # was blocking here forever
5661 re_execute_shell(&to_free,
5671 # if ENABLE_HUSH_FAST
5673 //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);
5675 enable_restore_tty_pgrp_on_exit();
5680 close_on_exec_on(channel[0]);
5681 return xfdopen_for_read(channel[0]);
5684 /* Return code is exit status of the process that is run. */
5685 static int process_command_subs(o_string *dest, const char *s)
5688 struct in_str pipe_str;
5690 int status, ch, eol_cnt;
5692 fp = generate_stream_from_string(s, &pid);
5694 /* Now send results of command back into original context */
5695 setup_file_in_str(&pipe_str, fp);
5697 while ((ch = i_getch(&pipe_str)) != EOF) {
5703 o_addchr(dest, '\n');
5706 o_addQchr(dest, ch);
5709 debug_printf("done reading from `cmd` pipe, closing it\n");
5711 /* We need to extract exitcode. Test case
5712 * "true; echo `sleep 1; false` $?"
5714 safe_waitpid(pid, &status, 0);
5715 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5716 return WEXITSTATUS(status);
5718 #endif /* ENABLE_HUSH_TICK */
5720 #if !ENABLE_HUSH_FUNCTIONS
5721 #define parse_group(dest, ctx, input, ch) \
5722 parse_group(ctx, input, ch)
5724 static int parse_group(o_string *dest, struct parse_context *ctx,
5725 struct in_str *input, int ch)
5727 /* dest contains characters seen prior to ( or {.
5728 * Typically it's empty, but for function defs,
5729 * it contains function name (without '()'). */
5730 struct pipe *pipe_list;
5732 struct command *command = ctx->command;
5734 debug_printf_parse("parse_group entered\n");
5735 #if ENABLE_HUSH_FUNCTIONS
5736 if (ch == '(' && !dest->o_quoted) {
5738 if (done_word(dest, ctx))
5741 goto skip; /* (... */
5742 if (command->argv[1]) { /* word word ... (... */
5743 syntax_error_unexpected_ch('(');
5746 /* it is "word(..." or "word (..." */
5748 ch = i_getch(input);
5749 while (ch == ' ' || ch == '\t');
5751 syntax_error_unexpected_ch(ch);
5754 nommu_addchr(&ctx->as_string, ch);
5756 ch = i_getch(input);
5757 while (ch == ' ' || ch == '\t' || ch == '\n');
5759 syntax_error_unexpected_ch(ch);
5762 nommu_addchr(&ctx->as_string, ch);
5763 command->cmd_type = CMD_FUNCDEF;
5768 #if 0 /* Prevented by caller */
5769 if (command->argv /* word [word]{... */
5770 || dest->length /* word{... */
5771 || dest->o_quoted /* ""{... */
5774 debug_printf_parse("parse_group return 1: "
5775 "syntax error, groups and arglists don't mix\n");
5780 #if ENABLE_HUSH_FUNCTIONS
5786 command->cmd_type = CMD_SUBSHELL;
5788 /* bash does not allow "{echo...", requires whitespace */
5789 ch = i_getch(input);
5790 if (ch != ' ' && ch != '\t' && ch != '\n') {
5791 syntax_error_unexpected_ch(ch);
5794 nommu_addchr(&ctx->as_string, ch);
5799 # define as_string NULL
5801 char *as_string = NULL;
5803 pipe_list = parse_stream(&as_string, input, endch);
5806 o_addstr(&ctx->as_string, as_string);
5808 /* empty ()/{} or parse error? */
5809 if (!pipe_list || pipe_list == ERR_PTR) {
5810 /* parse_stream already emitted error msg */
5813 debug_printf_parse("parse_group return 1: "
5814 "parse_stream returned %p\n", pipe_list);
5817 command->group = pipe_list;
5819 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5820 command->group_as_string = as_string;
5821 debug_printf_parse("end of group, remembering as:'%s'\n",
5822 command->group_as_string);
5826 debug_printf_parse("parse_group return 0\n");
5828 /* command remains "open", available for possible redirects */
5831 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5832 /* Subroutines for copying $(...) and `...` things */
5833 static void add_till_backquote(o_string *dest, struct in_str *input);
5835 static void add_till_single_quote(o_string *dest, struct in_str *input)
5838 int ch = i_getch(input);
5840 syntax_error_unterm_ch('\'');
5841 /*xfunc_die(); - redundant */
5848 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5849 static void add_till_double_quote(o_string *dest, struct in_str *input)
5852 int ch = i_getch(input);
5854 syntax_error_unterm_ch('"');
5855 /*xfunc_die(); - redundant */
5859 if (ch == '\\') { /* \x. Copy both chars. */
5861 ch = i_getch(input);
5865 add_till_backquote(dest, input);
5869 //if (ch == '$') ...
5872 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5874 * "Within the backquoted style of command substitution, backslash
5875 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5876 * The search for the matching backquote shall be satisfied by the first
5877 * backquote found without a preceding backslash; during this search,
5878 * if a non-escaped backquote is encountered within a shell comment,
5879 * a here-document, an embedded command substitution of the $(command)
5880 * form, or a quoted string, undefined results occur. A single-quoted
5881 * or double-quoted string that begins, but does not end, within the
5882 * "`...`" sequence produces undefined results."
5884 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5886 static void add_till_backquote(o_string *dest, struct in_str *input)
5889 int ch = i_getch(input);
5891 syntax_error_unterm_ch('`');
5892 /*xfunc_die(); - redundant */
5897 /* \x. Copy both chars unless it is \` */
5898 int ch2 = i_getch(input);
5900 syntax_error_unterm_ch('`');
5901 /*xfunc_die(); - redundant */
5903 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5910 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5911 * quoting and nested ()s.
5912 * "With the $(command) style of command substitution, all characters
5913 * following the open parenthesis to the matching closing parenthesis
5914 * constitute the command. Any valid shell script can be used for command,
5915 * except a script consisting solely of redirections which produces
5916 * unspecified results."
5918 * echo $(echo '(TEST)' BEST) (TEST) BEST
5919 * echo $(echo 'TEST)' BEST) TEST) BEST
5920 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5922 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
5923 * can contain arbitrary constructs, just like $(cmd).
5924 * In bash compat mode, it needs to also be able to stop on '}' or ':'
5925 * for ${var:N[:M]} parsing.
5927 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
5928 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
5931 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
5932 #if ENABLE_HUSH_BASH_COMPAT
5933 char end_char2 = end_ch >> 8;
5935 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
5938 ch = i_getch(input);
5940 syntax_error_unterm_ch(end_ch);
5941 /*xfunc_die(); - redundant */
5943 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
5946 /* we look for closing )) of $((EXPR)) */
5947 if (i_peek(input) == end_ch) {
5948 i_getch(input); /* eat second ')' */
5953 if (ch == '(' || ch == '{') {
5954 ch = (ch == '(' ? ')' : '}');
5955 add_till_closing_bracket(dest, input, ch);
5960 add_till_single_quote(dest, input);
5965 add_till_double_quote(dest, input);
5970 add_till_backquote(dest, input);
5975 /* \x. Copy verbatim. Important for \(, \) */
5976 ch = i_getch(input);
5978 syntax_error_unterm_ch(')');
5979 /*xfunc_die(); - redundant */
5987 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5989 /* Return code: 0 for OK, 1 for syntax error */
5991 #define handle_dollar(as_string, dest, input) \
5992 handle_dollar(dest, input)
5993 #define as_string NULL
5995 static int handle_dollar(o_string *as_string,
5997 struct in_str *input)
5999 int ch = i_peek(input); /* first character after the $ */
6000 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
6002 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
6004 ch = i_getch(input);
6005 nommu_addchr(as_string, ch);
6007 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6009 debug_printf_parse(": '%c'\n", ch);
6010 o_addchr(dest, ch | quote_mask);
6013 if (!isalnum(ch) && ch != '_')
6015 ch = i_getch(input);
6016 nommu_addchr(as_string, ch);
6018 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6019 } else if (isdigit(ch)) {
6021 ch = i_getch(input);
6022 nommu_addchr(as_string, ch);
6023 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6024 debug_printf_parse(": '%c'\n", ch);
6025 o_addchr(dest, ch | quote_mask);
6026 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6027 } else switch (ch) {
6029 case '!': /* last bg pid */
6030 case '?': /* last exit code */
6031 case '#': /* number of args */
6032 case '*': /* args */
6033 case '@': /* args */
6034 goto make_one_char_var;
6036 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6038 ch = i_getch(input); /* eat '{' */
6039 nommu_addchr(as_string, ch);
6041 ch = i_getch(input); /* first char after '{' */
6042 nommu_addchr(as_string, ch);
6043 /* It should be ${?}, or ${#var},
6044 * or even ${?+subst} - operator acting on a special variable,
6045 * or the beginning of variable name.
6047 if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
6049 syntax_error_unterm_str("${name}");
6050 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
6055 /* It's possible to just call add_till_closing_bracket() at this point.
6056 * However, this regresses some of our testsuite cases
6057 * which check invalid constructs like ${%}.
6058 * Oh well... let's check that the var name part is fine... */
6064 debug_printf_parse(": '%c'\n", ch);
6066 ch = i_getch(input);
6067 nommu_addchr(as_string, ch);
6071 if (!isalnum(ch) && ch != '_') {
6073 unsigned char last_ch;
6074 /* handle parameter expansions
6075 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
6077 if (!strchr("%#:-=+?", ch)) /* ${var<bad_char>... */
6078 goto bad_dollar_syntax;
6081 /* Eat everything until closing '}' (or ':') */
6083 if (ENABLE_HUSH_BASH_COMPAT
6085 && !strchr("%#:-=+?"+3, i_peek(input))
6087 /* It's ${var:N[:M]} thing */
6088 end_ch = '}' * 0x100 + ':';
6093 last_ch = add_till_closing_bracket(dest, input, end_ch);
6095 o_addstr(as_string, dest->data + pos);
6096 o_addchr(as_string, last_ch);
6099 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
6100 /* close the first block: */
6101 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6102 /* while parsing N from ${var:N[:M]}... */
6103 if ((end_ch & 0xff) == last_ch) {
6104 /* ...got ':' - parse the rest */
6108 /* ...got '}', not ':' - it's ${var:N}! emulate :999999999 */
6109 o_addstr(dest, "999999999");
6114 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6117 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
6121 ch = i_getch(input);
6122 nommu_addchr(as_string, ch);
6123 # if ENABLE_SH_MATH_SUPPORT
6124 if (i_peek(input) == '(') {
6125 ch = i_getch(input);
6126 nommu_addchr(as_string, ch);
6127 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6128 o_addchr(dest, /*quote_mask |*/ '+');
6131 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
6134 o_addstr(as_string, dest->data + pos);
6135 o_addchr(as_string, ')');
6136 o_addchr(as_string, ')');
6139 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6143 # if ENABLE_HUSH_TICK
6144 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6145 o_addchr(dest, quote_mask | '`');
6148 add_till_closing_bracket(dest, input, ')');
6151 o_addstr(as_string, dest->data + pos);
6152 o_addchr(as_string, ')');
6155 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6161 ch = i_getch(input);
6162 nommu_addchr(as_string, ch);
6164 if (isalnum(ch)) { /* it's $_name or $_123 */
6169 /* TODO: $_ and $-: */
6170 /* $_ Shell or shell script name; or last argument of last command
6171 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
6172 * but in command's env, set to full pathname used to invoke it */
6173 /* $- Option flags set by set builtin or shell options (-i etc) */
6175 o_addQchr(dest, '$');
6177 debug_printf_parse("handle_dollar return 0\n");
6183 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
6184 parse_stream_dquoted(dest, input, dquote_end)
6185 #define as_string NULL
6187 static int parse_stream_dquoted(o_string *as_string,
6189 struct in_str *input,
6196 ch = i_getch(input);
6198 nommu_addchr(as_string, ch);
6199 if (ch == dquote_end) { /* may be only '"' or EOF */
6200 if (dest->o_assignment == NOT_ASSIGNMENT)
6201 dest->o_escape ^= 1;
6202 debug_printf_parse("parse_stream_dquoted return 0\n");
6205 /* note: can't move it above ch == dquote_end check! */
6207 syntax_error_unterm_ch('"');
6208 /*xfunc_die(); - redundant */
6212 next = i_peek(input);
6214 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
6215 ch, ch, dest->o_escape);
6218 syntax_error("\\<eof>");
6222 * "The backslash retains its special meaning [in "..."]
6223 * only when followed by one of the following characters:
6224 * $, `, ", \, or <newline>. A double quote may be quoted
6225 * within double quotes by preceding it with a backslash."
6227 if (strchr("$`\"\\\n", next) != NULL) {
6228 ch = i_getch(input);
6230 o_addqchr(dest, ch);
6231 nommu_addchr(as_string, ch);
6234 o_addqchr(dest, '\\');
6235 nommu_addchr(as_string, '\\');
6240 if (handle_dollar(as_string, dest, input) != 0) {
6241 debug_printf_parse("parse_stream_dquoted return 1: "
6242 "handle_dollar returned non-0\n");
6247 #if ENABLE_HUSH_TICK
6249 //unsigned pos = dest->length;
6250 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6251 o_addchr(dest, 0x80 | '`');
6252 add_till_backquote(dest, input);
6253 o_addchr(dest, SPECIAL_VAR_SYMBOL);
6254 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
6258 o_addQchr(dest, ch);
6260 && (dest->o_assignment == MAYBE_ASSIGNMENT
6261 || dest->o_assignment == WORD_IS_KEYWORD)
6262 && is_well_formed_var_name(dest->data, '=')
6264 dest->o_assignment = DEFINITELY_ASSIGNMENT;
6271 * Scan input until EOF or end_trigger char.
6272 * Return a list of pipes to execute, or NULL on EOF
6273 * or if end_trigger character is met.
6274 * On syntax error, exit is shell is not interactive,
6275 * reset parsing machinery and start parsing anew,
6276 * or return ERR_PTR.
6278 static struct pipe *parse_stream(char **pstring,
6279 struct in_str *input,
6282 struct parse_context ctx;
6283 o_string dest = NULL_O_STRING;
6287 /* Double-quote state is handled in the state variable is_in_dquote.
6288 * A single-quote triggers a bypass of the main loop until its mate is
6289 * found. When recursing, quote state is passed in via dest->o_escape.
6291 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
6292 end_trigger ? end_trigger : 'X');
6295 /* If very first arg is "" or '', dest.data may end up NULL.
6296 * Preventing this: */
6297 o_addchr(&dest, '\0');
6300 G.ifs = get_local_var_value("IFS");
6305 #if ENABLE_HUSH_INTERACTIVE
6306 input->promptmode = 0; /* PS1 */
6308 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
6309 initialize_context(&ctx);
6314 const char *is_special;
6318 redir_type redir_style;
6321 /* dest.o_quoted = 1; - already is (see below) */
6322 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
6325 /* We reached closing '"' */
6328 ch = i_getch(input);
6329 debug_printf_parse(": ch=%c (%d) escape=%d\n",
6330 ch, ch, dest.o_escape);
6335 syntax_error_unterm_str("here document");
6338 /* end_trigger == '}' case errors out earlier,
6339 * checking only ')' */
6340 if (end_trigger == ')') {
6341 syntax_error_unterm_ch('('); /* exits */
6342 /* goto parse_error; */
6345 if (done_word(&dest, &ctx)) {
6349 done_pipe(&ctx, PIPE_SEQ);
6351 /* If we got nothing... */
6352 /* (this makes bare "&" cmd a no-op.
6353 * bash says: "syntax error near unexpected token '&'") */
6354 if (pi->num_cmds == 0
6355 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
6361 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6363 *pstring = ctx.as_string.data;
6365 o_free_unsafe(&ctx.as_string);
6368 debug_printf_parse("parse_stream return %p\n", pi);
6371 nommu_addchr(&ctx.as_string, ch);
6375 next = i_peek(input);
6377 is_special = "{}<>;&|()#'" /* special outside of "str" */
6378 "\\$\"" IF_HUSH_TICK("`"); /* always special */
6379 /* Are { and } special here? */
6380 if (ctx.command->argv /* word [word]{... - non-special */
6381 || dest.length /* word{... - non-special */
6382 || dest.o_quoted /* ""{... - non-special */
6383 || (next != ';' /* }; - special */
6384 && next != ')' /* }) - special */
6385 && next != '&' /* }& and }&& ... - special */
6386 && next != '|' /* }|| ... - special */
6387 && !strchr(G.ifs, next) /* {word - non-special */
6390 /* They are not special, skip "{}" */
6393 is_special = strchr(is_special, ch);
6394 is_ifs = strchr(G.ifs, ch);
6396 if (!is_special && !is_ifs) { /* ordinary char */
6398 o_addQchr(&dest, ch);
6399 if ((dest.o_assignment == MAYBE_ASSIGNMENT
6400 || dest.o_assignment == WORD_IS_KEYWORD)
6402 && is_well_formed_var_name(dest.data, '=')
6404 dest.o_assignment = DEFINITELY_ASSIGNMENT;
6410 if (done_word(&dest, &ctx)) {
6414 #if ENABLE_HUSH_CASE
6415 /* "case ... in <newline> word) ..." -
6416 * newlines are ignored (but ';' wouldn't be) */
6417 if (ctx.command->argv == NULL
6418 && ctx.ctx_res_w == RES_MATCH
6423 /* Treat newline as a command separator. */
6424 done_pipe(&ctx, PIPE_SEQ);
6425 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
6427 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
6432 dest.o_assignment = MAYBE_ASSIGNMENT;
6434 /* note: if (is_ifs) continue;
6435 * will still trigger for us */
6439 /* "cmd}" or "cmd }..." without semicolon or &:
6440 * } is an ordinary char in this case, even inside { cmd; }
6441 * Pathological example: { ""}; } should exec "}" cmd
6444 if (!IS_NULL_CMD(ctx.command) /* cmd } */
6445 || dest.length != 0 /* word} */
6446 || dest.o_quoted /* ""} */
6450 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
6451 goto skip_end_trigger;
6452 /* else: } does terminate a group */
6455 if (end_trigger && end_trigger == ch
6456 && (ch != ';' || heredoc_cnt == 0)
6457 #if ENABLE_HUSH_CASE
6459 || ctx.ctx_res_w != RES_MATCH
6460 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
6465 /* This is technically valid:
6466 * { cat <<HERE; }; echo Ok
6470 * but we don't support this.
6471 * We require heredoc to be in enclosing {}/(),
6474 syntax_error_unterm_str("here document");
6477 if (done_word(&dest, &ctx)) {
6480 done_pipe(&ctx, PIPE_SEQ);
6481 dest.o_assignment = MAYBE_ASSIGNMENT;
6482 /* Do we sit outside of any if's, loops or case's? */
6484 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
6488 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
6490 *pstring = ctx.as_string.data;
6492 o_free_unsafe(&ctx.as_string);
6495 debug_printf_parse("parse_stream return %p: "
6496 "end_trigger char found\n",
6498 return ctx.list_head;
6505 /* Catch <, > before deciding whether this word is
6506 * an assignment. a=1 2>z b=2: b=2 is still assignment */
6509 redir_fd = redirect_opt_num(&dest);
6510 if (done_word(&dest, &ctx)) {
6513 redir_style = REDIRECT_OVERWRITE;
6515 redir_style = REDIRECT_APPEND;
6516 ch = i_getch(input);
6517 nommu_addchr(&ctx.as_string, ch);
6520 else if (next == '(') {
6521 syntax_error(">(process) not supported");
6525 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6527 continue; /* back to top of while (1) */
6529 redir_fd = redirect_opt_num(&dest);
6530 if (done_word(&dest, &ctx)) {
6533 redir_style = REDIRECT_INPUT;
6535 redir_style = REDIRECT_HEREDOC;
6537 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6538 ch = i_getch(input);
6539 nommu_addchr(&ctx.as_string, ch);
6540 } else if (next == '>') {
6541 redir_style = REDIRECT_IO;
6542 ch = i_getch(input);
6543 nommu_addchr(&ctx.as_string, ch);
6546 else if (next == '(') {
6547 syntax_error("<(process) not supported");
6551 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6553 continue; /* back to top of while (1) */
6556 if (dest.o_assignment == MAYBE_ASSIGNMENT
6557 /* check that we are not in word in "a=1 2>word b=1": */
6558 && !ctx.pending_redirect
6560 /* ch is a special char and thus this word
6561 * cannot be an assignment */
6562 dest.o_assignment = NOT_ASSIGNMENT;
6565 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6569 if (dest.length == 0) {
6572 if (ch == EOF || ch == '\n')
6575 /* note: we do not add it to &ctx.as_string */
6577 nommu_addchr(&ctx.as_string, '\n');
6579 o_addQchr(&dest, ch);
6584 syntax_error("\\<eof>");
6587 ch = i_getch(input);
6589 o_addchr(&dest, '\\');
6590 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6591 o_addchr(&dest, ch);
6592 nommu_addchr(&ctx.as_string, ch);
6593 /* Example: echo Hello \2>file
6594 * we need to know that word 2 is quoted */
6599 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6600 ctx.as_string.data[--ctx.as_string.length] = '\0';
6605 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6606 debug_printf_parse("parse_stream parse error: "
6607 "handle_dollar returned non-0\n");
6614 ch = i_getch(input);
6616 syntax_error_unterm_ch('\'');
6617 /*xfunc_die(); - redundant */
6619 nommu_addchr(&ctx.as_string, ch);
6622 o_addqchr(&dest, ch);
6627 is_in_dquote ^= 1; /* invert */
6628 if (dest.o_assignment == NOT_ASSIGNMENT)
6631 #if ENABLE_HUSH_TICK
6636 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6637 o_addchr(&dest, '`');
6641 add_till_backquote(&dest, input);
6643 o_addstr(&ctx.as_string, dest.data + pos);
6644 o_addchr(&ctx.as_string, '`');
6646 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6647 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6652 #if ENABLE_HUSH_CASE
6655 if (done_word(&dest, &ctx)) {
6658 done_pipe(&ctx, PIPE_SEQ);
6659 #if ENABLE_HUSH_CASE
6660 /* Eat multiple semicolons, detect
6661 * whether it means something special */
6666 ch = i_getch(input);
6667 nommu_addchr(&ctx.as_string, ch);
6668 if (ctx.ctx_res_w == RES_CASE_BODY) {
6669 ctx.ctx_dsemicolon = 1;
6670 ctx.ctx_res_w = RES_MATCH;
6676 /* We just finished a cmd. New one may start
6677 * with an assignment */
6678 dest.o_assignment = MAYBE_ASSIGNMENT;
6681 if (done_word(&dest, &ctx)) {
6685 ch = i_getch(input);
6686 nommu_addchr(&ctx.as_string, ch);
6687 done_pipe(&ctx, PIPE_AND);
6689 done_pipe(&ctx, PIPE_BG);
6693 if (done_word(&dest, &ctx)) {
6696 #if ENABLE_HUSH_CASE
6697 if (ctx.ctx_res_w == RES_MATCH)
6698 break; /* we are in case's "word | word)" */
6700 if (next == '|') { /* || */
6701 ch = i_getch(input);
6702 nommu_addchr(&ctx.as_string, ch);
6703 done_pipe(&ctx, PIPE_OR);
6705 /* we could pick up a file descriptor choice here
6706 * with redirect_opt_num(), but bash doesn't do it.
6707 * "echo foo 2| cat" yields "foo 2". */
6710 o_reset_to_empty_unquoted(&ctx.as_string);
6715 #if ENABLE_HUSH_CASE
6716 /* "case... in [(]word)..." - skip '(' */
6717 if (ctx.ctx_res_w == RES_MATCH
6718 && ctx.command->argv == NULL /* not (word|(... */
6719 && dest.length == 0 /* not word(... */
6720 && dest.o_quoted == 0 /* not ""(... */
6726 if (parse_group(&dest, &ctx, input, ch) != 0) {
6731 #if ENABLE_HUSH_CASE
6732 if (ctx.ctx_res_w == RES_MATCH)
6736 /* proper use of this character is caught by end_trigger:
6737 * if we see {, we call parse_group(..., end_trigger='}')
6738 * and it will match } earlier (not here). */
6739 syntax_error_unexpected_ch(ch);
6743 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6749 struct parse_context *pctx;
6750 IF_HAS_KEYWORDS(struct parse_context *p2;)
6752 /* Clean up allocated tree.
6753 * Sample for finding leaks on syntax error recovery path.
6754 * Run it from interactive shell, watch pmap `pidof hush`.
6755 * while if false; then false; fi; do break; fi
6756 * Samples to catch leaks at execution:
6757 * while if (true | {true;}); then echo ok; fi; do break; done
6758 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6762 /* Update pipe/command counts,
6763 * otherwise freeing may miss some */
6764 done_pipe(pctx, PIPE_SEQ);
6765 debug_printf_clean("freeing list %p from ctx %p\n",
6766 pctx->list_head, pctx);
6767 debug_print_tree(pctx->list_head, 0);
6768 free_pipe_list(pctx->list_head);
6769 debug_printf_clean("freed list %p\n", pctx->list_head);
6771 o_free_unsafe(&pctx->as_string);
6773 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6777 IF_HAS_KEYWORDS(pctx = p2;)
6778 } while (HAS_KEYWORDS && pctx);
6779 /* Free text, clear all dest fields */
6781 /* If we are not in top-level parse, we return,
6782 * our caller will propagate error.
6784 if (end_trigger != ';') {
6792 /* Discard cached input, force prompt */
6794 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6799 /* Executing from string: eval, sh -c '...'
6800 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6801 * end_trigger controls how often we stop parsing
6802 * NUL: parse all, execute, return
6803 * ';': parse till ';' or newline, execute, repeat till EOF
6805 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6807 /* Why we need empty flag?
6808 * An obscure corner case "false; ``; echo $?":
6809 * empty command in `` should still set $? to 0.
6810 * But we can't just set $? to 0 at the start,
6811 * this breaks "false; echo `echo $?`" case.
6815 struct pipe *pipe_list;
6817 pipe_list = parse_stream(NULL, inp, end_trigger);
6818 if (!pipe_list) { /* EOF */
6820 G.last_exitcode = 0;
6823 debug_print_tree(pipe_list, 0);
6824 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6825 run_and_free_list(pipe_list);
6830 static void parse_and_run_string(const char *s)
6832 struct in_str input;
6833 setup_string_in_str(&input, s);
6834 parse_and_run_stream(&input, '\0');
6837 static void parse_and_run_file(FILE *f)
6839 struct in_str input;
6840 setup_file_in_str(&input, f);
6841 parse_and_run_stream(&input, ';');
6844 /* Called a few times only (or even once if "sh -c") */
6845 static void init_sigmasks(void)
6849 sigset_t old_blocked_set;
6851 if (!G.inherited_set_is_saved) {
6852 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6853 G.inherited_set = G.blocked_set;
6855 old_blocked_set = G.blocked_set;
6857 mask = (1 << SIGQUIT);
6858 if (G_interactive_fd) {
6859 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6860 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6861 mask |= SPECIAL_JOB_SIGS;
6863 G.non_DFL_mask = mask;
6868 sigaddset(&G.blocked_set, sig);
6872 sigdelset(&G.blocked_set, SIGCHLD);
6874 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
6875 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6877 /* POSIX allows shell to re-enable SIGCHLD
6878 * even if it was SIG_IGN on entry */
6879 #if ENABLE_HUSH_FAST
6880 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6881 if (!G.inherited_set_is_saved)
6882 signal(SIGCHLD, SIGCHLD_handler);
6884 if (!G.inherited_set_is_saved)
6885 signal(SIGCHLD, SIG_DFL);
6888 G.inherited_set_is_saved = 1;
6893 static void maybe_set_to_sigexit(int sig)
6895 void (*handler)(int);
6896 /* non_DFL_mask'ed signals are, well, masked,
6897 * no need to set handler for them.
6899 if (!((G.non_DFL_mask >> sig) & 1)) {
6900 handler = signal(sig, sigexit);
6901 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6902 signal(sig, handler);
6905 /* Set handlers to restore tty pgrp and exit */
6906 static void set_fatal_handlers(void)
6908 /* We _must_ restore tty pgrp on fatal signals */
6910 maybe_set_to_sigexit(SIGILL );
6911 maybe_set_to_sigexit(SIGFPE );
6912 maybe_set_to_sigexit(SIGBUS );
6913 maybe_set_to_sigexit(SIGSEGV);
6914 maybe_set_to_sigexit(SIGTRAP);
6915 } /* else: hush is perfect. what SEGV? */
6916 maybe_set_to_sigexit(SIGABRT);
6917 /* bash 3.2 seems to handle these just like 'fatal' ones */
6918 maybe_set_to_sigexit(SIGPIPE);
6919 maybe_set_to_sigexit(SIGALRM);
6920 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6921 * if we aren't interactive... but in this case
6922 * we never want to restore pgrp on exit, and this fn is not called */
6923 /*maybe_set_to_sigexit(SIGHUP );*/
6924 /*maybe_set_to_sigexit(SIGTERM);*/
6925 /*maybe_set_to_sigexit(SIGINT );*/
6929 static int set_mode(const char cstate, const char mode)
6931 int state = (cstate == '-' ? 1 : 0);
6933 case 'n': G.fake_mode = state; break;
6934 case 'x': /*G.debug_mode = state;*/ break;
6935 default: return EXIT_FAILURE;
6937 return EXIT_SUCCESS;
6940 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6941 int hush_main(int argc, char **argv)
6943 static const struct variable const_shell_ver = {
6945 .varstr = (char*)hush_version_str,
6946 .max_len = 1, /* 0 can provoke free(name) */
6951 unsigned builtin_argc;
6953 struct variable *cur_var;
6956 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
6957 G.last_exitcode = EXIT_SUCCESS;
6959 G.argv0_for_re_execing = argv[0];
6961 /* Deal with HUSH_VERSION */
6962 G.shell_ver = const_shell_ver; /* copying struct here */
6963 G.top_var = &G.shell_ver;
6964 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6965 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6966 /* Initialize our shell local variables with the values
6967 * currently living in the environment */
6968 cur_var = G.top_var;
6971 char *value = strchr(*e, '=');
6972 if (value) { /* paranoia */
6973 cur_var->next = xzalloc(sizeof(*cur_var));
6974 cur_var = cur_var->next;
6975 cur_var->varstr = *e;
6976 cur_var->max_len = strlen(*e);
6977 cur_var->flg_export = 1;
6981 /* reinstate HUSH_VERSION */
6982 debug_printf_env("putenv '%s'\n", hush_version_str);
6983 putenv((char *)hush_version_str);
6986 set_pwd_var(/*exp:*/ 1);
6987 /* bash also exports SHLVL and _,
6988 * and sets (but doesn't export) the following variables:
6990 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
6991 * BASH_VERSION='3.2.0(1)-release'
6993 * MACHTYPE=i386-pc-linux-gnu
6995 * HOSTNAME=<xxxxxxxxxx>
6996 * PPID=<NNNNN> - we also do it elsewhere
7007 * PIPESTATUS=([0]="0")
7008 * HISTFILE=/<xxx>/.bash_history
7012 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7014 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7024 #if ENABLE_FEATURE_EDITING
7025 G.line_input_state = new_line_input_t(FOR_SHELL);
7027 G.global_argc = argc;
7028 G.global_argv = argv;
7029 /* Initialize some more globals to non-zero values */
7030 cmdedit_update_prompt();
7032 if (setjmp(die_jmp)) {
7033 /* xfunc has failed! die die die */
7034 /* no EXIT traps, this is an escape hatch! */
7036 hush_exit(xfunc_error_retval);
7039 /* Shell is non-interactive at first. We need to call
7040 * init_sigmasks() if we are going to execute "sh <script>",
7041 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7042 * If we later decide that we are interactive, we run init_sigmasks()
7043 * in order to intercept (more) signals.
7047 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7050 opt = getopt(argc, argv, "+c:xins"
7053 # if ENABLE_HUSH_FUNCTIONS
7063 * sh ... -c 'script'
7064 * sh ... -c 'script' ARG0 [ARG1...]
7065 * On NOMMU, if builtin_argc != 0,
7066 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7067 * "" needs to be replaced with NULL
7068 * and BARGV vector fed to builtin function.
7069 * Note: the form without ARG0 never happens:
7070 * sh ... -c 'builtin' BARGV... ""
7073 G.root_pid = getpid();
7074 G.root_ppid = getppid();
7076 G.global_argv = argv + optind;
7077 G.global_argc = argc - optind;
7079 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7080 const struct built_in_command *x;
7083 x = find_builtin(optarg);
7084 if (x) { /* paranoia */
7085 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7086 G.global_argv += builtin_argc;
7087 G.global_argv[-1] = NULL; /* replace "" */
7088 G.last_exitcode = x->b_function(argv + optind - 1);
7092 if (!G.global_argv[0]) {
7093 /* -c 'script' (no params): prevent empty $0 */
7094 G.global_argv--; /* points to argv[i] of 'script' */
7095 G.global_argv[0] = argv[0];
7096 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7098 parse_and_run_string(optarg);
7101 /* Well, we cannot just declare interactiveness,
7102 * we have to have some stuff (ctty, etc) */
7103 /* G_interactive_fd++; */
7106 /* "-s" means "read from stdin", but this is how we always
7107 * operate, so simply do nothing here. */
7110 case '<': /* "big heredoc" support */
7111 full_write(STDOUT_FILENO, optarg, strlen(optarg));
7114 unsigned long long empty_trap_mask;
7116 G.root_pid = bb_strtou(optarg, &optarg, 16);
7118 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7120 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7122 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7124 builtin_argc = bb_strtou(optarg, &optarg, 16);
7126 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7127 if (empty_trap_mask != 0) {
7130 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7131 for (sig = 1; sig < NSIG; sig++) {
7132 if (empty_trap_mask & (1LL << sig)) {
7133 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7134 sigaddset(&G.blocked_set, sig);
7137 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7139 # if ENABLE_HUSH_LOOPS
7141 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7147 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7149 # if ENABLE_HUSH_FUNCTIONS
7151 struct function *funcp = new_function(optarg);
7152 /* funcp->name is already set to optarg */
7153 /* funcp->body is set to NULL. It's a special case. */
7154 funcp->body_as_string = argv[optind];
7162 if (!set_mode('-', opt))
7166 fprintf(stderr, "Usage: sh [FILE]...\n"
7167 " or: sh -c command [args]...\n\n");
7173 } /* option parsing loop */
7176 G.root_pid = getpid();
7177 G.root_ppid = getppid();
7180 /* If we are login shell... */
7181 if (argv[0] && argv[0][0] == '-') {
7183 debug_printf("sourcing /etc/profile\n");
7184 input = fopen_for_read("/etc/profile");
7185 if (input != NULL) {
7186 close_on_exec_on(fileno(input));
7188 parse_and_run_file(input);
7191 /* bash: after sourcing /etc/profile,
7192 * tries to source (in the given order):
7193 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7194 * stopping on first found. --noprofile turns this off.
7195 * bash also sources ~/.bash_logout on exit.
7196 * If called as sh, skips .bash_XXX files.
7203 * "bash <script>" (which is never interactive (unless -i?))
7204 * sources $BASH_ENV here (without scanning $PATH).
7205 * If called as sh, does the same but with $ENV.
7207 debug_printf("running script '%s'\n", argv[optind]);
7208 G.global_argv = argv + optind;
7209 G.global_argc = argc - optind;
7210 input = xfopen_for_read(argv[optind]);
7211 close_on_exec_on(fileno(input));
7213 parse_and_run_file(input);
7214 #if ENABLE_FEATURE_CLEAN_UP
7220 /* Up to here, shell was non-interactive. Now it may become one.
7221 * NB: don't forget to (re)run init_sigmasks() as needed.
7224 /* A shell is interactive if the '-i' flag was given,
7225 * or if all of the following conditions are met:
7227 * no arguments remaining or the -s flag given
7228 * standard input is a terminal
7229 * standard output is a terminal
7230 * Refer to Posix.2, the description of the 'sh' utility.
7233 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7234 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7235 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7236 if (G_saved_tty_pgrp < 0)
7237 G_saved_tty_pgrp = 0;
7239 /* try to dup stdin to high fd#, >= 255 */
7240 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7241 if (G_interactive_fd < 0) {
7242 /* try to dup to any fd */
7243 G_interactive_fd = dup(STDIN_FILENO);
7244 if (G_interactive_fd < 0) {
7246 G_interactive_fd = 0;
7247 G_saved_tty_pgrp = 0;
7250 // TODO: track & disallow any attempts of user
7251 // to (inadvertently) close/redirect G_interactive_fd
7253 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7254 if (G_interactive_fd) {
7255 close_on_exec_on(G_interactive_fd);
7257 if (G_saved_tty_pgrp) {
7258 /* If we were run as 'hush &', sleep until we are
7259 * in the foreground (tty pgrp == our pgrp).
7260 * If we get started under a job aware app (like bash),
7261 * make sure we are now in charge so we don't fight over
7262 * who gets the foreground */
7264 pid_t shell_pgrp = getpgrp();
7265 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7266 if (G_saved_tty_pgrp == shell_pgrp)
7268 /* send TTIN to ourself (should stop us) */
7269 kill(- shell_pgrp, SIGTTIN);
7273 /* Block some signals */
7276 if (G_saved_tty_pgrp) {
7277 /* Set other signals to restore saved_tty_pgrp */
7278 set_fatal_handlers();
7279 /* Put ourselves in our own process group
7280 * (bash, too, does this only if ctty is available) */
7281 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7282 /* Grab control of the terminal */
7283 tcsetpgrp(G_interactive_fd, getpid());
7285 /* -1 is special - makes xfuncs longjmp, not exit
7286 * (we reset die_sleep = 0 whereever we [v]fork) */
7287 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7291 #elif ENABLE_HUSH_INTERACTIVE
7292 /* No job control compiled in, only prompt/line editing */
7293 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7294 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7295 if (G_interactive_fd < 0) {
7296 /* try to dup to any fd */
7297 G_interactive_fd = dup(STDIN_FILENO);
7298 if (G_interactive_fd < 0)
7300 G_interactive_fd = 0;
7303 if (G_interactive_fd) {
7304 close_on_exec_on(G_interactive_fd);
7308 /* We have interactiveness code disabled */
7312 * if interactive but not a login shell, sources ~/.bashrc
7313 * (--norc turns this off, --rcfile <file> overrides)
7316 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7317 /* note: ash and hush share this string */
7318 printf("\n\n%s %s\n"
7319 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7322 "hush - the humble shell"
7326 parse_and_run_file(stdin);
7329 #if ENABLE_FEATURE_CLEAN_UP
7330 if (G.cwd != bb_msg_unknown)
7332 cur_var = G.top_var->next;
7334 struct variable *tmp = cur_var;
7335 if (!cur_var->max_len)
7336 free(cur_var->varstr);
7337 cur_var = cur_var->next;
7341 hush_exit(G.last_exitcode);
7346 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7347 int lash_main(int argc, char **argv)
7349 bb_error_msg("lash is deprecated, please use hush instead");
7350 return hush_main(argc, argv);
7355 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7356 int msh_main(int argc, char **argv)
7358 //bb_error_msg("msh is deprecated, please use hush instead");
7359 return hush_main(argc, argv);
7367 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7372 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7379 return applet_main_func(argc, argv - argc);
7382 static int FAST_FUNC builtin_test(char **argv)
7384 return run_applet_main(argv, test_main);
7387 static int FAST_FUNC builtin_echo(char **argv)
7389 return run_applet_main(argv, echo_main);
7393 static int FAST_FUNC builtin_printf(char **argv)
7395 return run_applet_main(argv, printf_main);
7399 static char **skip_dash_dash(char **argv)
7402 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7407 static int FAST_FUNC builtin_eval(char **argv)
7409 int rcode = EXIT_SUCCESS;
7411 argv = skip_dash_dash(argv);
7413 char *str = expand_strvec_to_string(argv);
7415 * eval "echo Hi; done" ("done" is syntax error):
7416 * "echo Hi" will not execute too.
7418 parse_and_run_string(str);
7420 rcode = G.last_exitcode;
7425 static int FAST_FUNC builtin_cd(char **argv)
7429 argv = skip_dash_dash(argv);
7431 if (newdir == NULL) {
7432 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7433 * bash says "bash: cd: HOME not set" and does nothing
7436 const char *home = get_local_var_value("HOME");
7437 newdir = home ? home : "/";
7439 if (chdir(newdir)) {
7440 /* Mimic bash message exactly */
7441 bb_perror_msg("cd: %s", newdir);
7442 return EXIT_FAILURE;
7444 /* Read current dir (get_cwd(1) is inside) and set PWD.
7445 * Note: do not enforce exporting. If PWD was unset or unexported,
7446 * set it again, but do not export. bash does the same.
7448 set_pwd_var(/*exp:*/ 0);
7449 return EXIT_SUCCESS;
7452 static int FAST_FUNC builtin_exec(char **argv)
7454 argv = skip_dash_dash(argv);
7455 if (argv[0] == NULL)
7456 return EXIT_SUCCESS; /* bash does this */
7458 /* Careful: we can end up here after [v]fork. Do not restore
7459 * tty pgrp then, only top-level shell process does that */
7460 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7461 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7463 /* TODO: if exec fails, bash does NOT exit! We do.
7464 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7465 * and tcsetpgrp, and this is inherently racy.
7467 execvp_or_die(argv);
7470 static int FAST_FUNC builtin_exit(char **argv)
7472 debug_printf_exec("%s()\n", __func__);
7474 /* interactive bash:
7475 * # trap "echo EEE" EXIT
7478 * There are stopped jobs.
7479 * (if there are _stopped_ jobs, running ones don't count)
7482 # EEE (then bash exits)
7484 * we can use G.exiting = -1 as indicator "last cmd was exit"
7487 /* note: EXIT trap is run by hush_exit */
7488 argv = skip_dash_dash(argv);
7489 if (argv[0] == NULL)
7490 hush_exit(G.last_exitcode);
7491 /* mimic bash: exit 123abc == exit 255 + error msg */
7492 xfunc_error_retval = 255;
7493 /* bash: exit -2 == exit 254, no error msg */
7494 hush_exit(xatoi(argv[0]) & 0xff);
7497 static void print_escaped(const char *s)
7502 const char *p = strchrnul(s, '\'');
7503 /* print 'xxxx', possibly just '' */
7504 printf("'%.*s'", (int)(p - s), s);
7509 /* s points to '; print "'''...'''" */
7511 do putchar('\''); while (*++s == '\'');
7516 #if !ENABLE_HUSH_LOCAL
7517 #define helper_export_local(argv, exp, lvl) \
7518 helper_export_local(argv, exp)
7520 static void helper_export_local(char **argv, int exp, int lvl)
7525 /* So far we do not check that name is valid (TODO?) */
7527 if (strchr(name, '=') == NULL) {
7528 struct variable *var;
7530 var = get_local_var(name);
7531 if (exp == -1) { /* unexporting? */
7532 /* export -n NAME (without =VALUE) */
7534 var->flg_export = 0;
7535 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
7537 } /* else: export -n NOT_EXISTING_VAR: no-op */
7540 if (exp == 1) { /* exporting? */
7541 /* export NAME (without =VALUE) */
7543 var->flg_export = 1;
7544 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
7545 putenv(var->varstr);
7549 /* Exporting non-existing variable.
7550 * bash does not put it in environment,
7551 * but remembers that it is exported,
7552 * and does put it in env when it is set later.
7553 * We just set it to "" and export. */
7554 /* Or, it's "local NAME" (without =VALUE).
7555 * bash sets the value to "". */
7556 name = xasprintf("%s=", name);
7558 /* (Un)exporting/making local NAME=VALUE */
7559 name = xstrdup(name);
7561 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
7565 static int FAST_FUNC builtin_export(char **argv)
7567 unsigned opt_unexport;
7569 #if ENABLE_HUSH_EXPORT_N
7570 /* "!": do not abort on errors */
7571 opt_unexport = getopt32(argv, "!n");
7572 if (opt_unexport == (uint32_t)-1)
7573 return EXIT_FAILURE;
7580 if (argv[0] == NULL) {
7587 /* ash emits: export VAR='VAL'
7588 * bash: declare -x VAR="VAL"
7589 * we follow ash example */
7590 const char *s = *e++;
7591 const char *p = strchr(s, '=');
7593 if (!p) /* wtf? take next variable */
7596 printf("export %.*s", (int)(p - s) + 1, s);
7597 print_escaped(p + 1);
7601 /*fflush_all(); - done after each builtin anyway */
7603 return EXIT_SUCCESS;
7606 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
7608 return EXIT_SUCCESS;
7611 #if ENABLE_HUSH_LOCAL
7612 static int FAST_FUNC builtin_local(char **argv)
7614 if (G.func_nest_level == 0) {
7615 bb_error_msg("%s: not in a function", argv[0]);
7616 return EXIT_FAILURE; /* bash compat */
7618 helper_export_local(argv, 0, G.func_nest_level);
7619 return EXIT_SUCCESS;
7623 static int FAST_FUNC builtin_trap(char **argv)
7629 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7634 /* No args: print all trapped */
7635 for (i = 0; i < NSIG; ++i) {
7638 print_escaped(G.traps[i]);
7639 /* note: bash adds "SIG", but only if invoked
7640 * as "bash". If called as "sh", or if set -o posix,
7641 * then it prints short signal names.
7642 * We are printing short names: */
7643 printf(" %s\n", get_signame(i));
7646 /*fflush_all(); - done after each builtin anyway */
7647 return EXIT_SUCCESS;
7651 /* If first arg is a number: reset all specified signals */
7652 sig = bb_strtou(*argv, NULL, 10);
7658 sig = get_signum(*argv++);
7659 if (sig < 0 || sig >= NSIG) {
7661 /* Mimic bash message exactly */
7662 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7667 G.traps[sig] = xstrdup(new_cmd);
7669 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
7670 get_signame(sig), sig, G.traps[sig]);
7672 /* There is no signal for 0 (EXIT) */
7677 sigaddset(&G.blocked_set, sig);
7679 /* There was a trap handler, we are removing it
7680 * (if sig has non-DFL handling,
7681 * we don't need to do anything) */
7682 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7684 sigdelset(&G.blocked_set, sig);
7687 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7691 if (!argv[1]) { /* no second arg */
7692 bb_error_msg("trap: invalid arguments");
7693 return EXIT_FAILURE;
7696 /* First arg is "-": reset all specified to default */
7697 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7698 /* Everything else: set arg as signal handler
7699 * (includes "" case, which ignores signal) */
7700 if (argv[0][0] == '-') {
7701 if (argv[0][1] == '\0') { /* "-" */
7702 /* new_cmd remains NULL: "reset these sigs" */
7705 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7708 /* else: "-something", no special meaning */
7713 goto process_sig_list;
7716 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7717 static int FAST_FUNC builtin_type(char **argv)
7719 int ret = EXIT_SUCCESS;
7725 if (0) {} /* make conditional compile easier below */
7726 /*else if (find_alias(*argv))
7727 type = "an alias";*/
7728 #if ENABLE_HUSH_FUNCTIONS
7729 else if (find_function(*argv))
7730 type = "a function";
7732 else if (find_builtin(*argv))
7733 type = "a shell builtin";
7734 else if ((path = find_in_path(*argv)) != NULL)
7737 bb_error_msg("type: %s: not found", *argv);
7742 printf("%s is %s\n", *argv, type);
7750 /* built-in 'fg' and 'bg' handler */
7751 static int FAST_FUNC builtin_fg_bg(char **argv)
7756 if (!G_interactive_fd)
7757 return EXIT_FAILURE;
7759 /* If they gave us no args, assume they want the last backgrounded task */
7761 for (pi = G.job_list; pi; pi = pi->next) {
7762 if (pi->jobid == G.last_jobid) {
7766 bb_error_msg("%s: no current job", argv[0]);
7767 return EXIT_FAILURE;
7769 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7770 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7771 return EXIT_FAILURE;
7773 for (pi = G.job_list; pi; pi = pi->next) {
7774 if (pi->jobid == jobnum) {
7778 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7779 return EXIT_FAILURE;
7781 /* TODO: bash prints a string representation
7782 * of job being foregrounded (like "sleep 1 | cat") */
7783 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7784 /* Put the job into the foreground. */
7785 tcsetpgrp(G_interactive_fd, pi->pgrp);
7788 /* Restart the processes in the job */
7789 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7790 for (i = 0; i < pi->num_cmds; i++) {
7791 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7792 pi->cmds[i].is_stopped = 0;
7794 pi->stopped_cmds = 0;
7796 i = kill(- pi->pgrp, SIGCONT);
7798 if (errno == ESRCH) {
7799 delete_finished_bg_job(pi);
7800 return EXIT_SUCCESS;
7802 bb_perror_msg("kill (SIGCONT)");
7805 if (argv[0][0] == 'f') {
7807 return checkjobs_and_fg_shell(pi);
7809 return EXIT_SUCCESS;
7813 #if ENABLE_HUSH_HELP
7814 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7816 const struct built_in_command *x;
7819 "Built-in commands:\n"
7820 "------------------\n");
7821 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7823 printf("%-10s%s\n", x->b_cmd, x->b_descr);
7826 return EXIT_SUCCESS;
7831 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7834 const char *status_string;
7836 for (job = G.job_list; job; job = job->next) {
7837 if (job->alive_cmds == job->stopped_cmds)
7838 status_string = "Stopped";
7840 status_string = "Running";
7842 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7844 return EXIT_SUCCESS;
7849 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7854 # ifdef M_TRIM_THRESHOLD
7855 /* Optional. Reduces probability of false positives */
7858 /* Crude attempt to find where "free memory" starts,
7859 * sans fragmentation. */
7861 l = (unsigned long)p;
7864 if (l < (unsigned long)p) l = (unsigned long)p;
7867 if (!G.memleak_value)
7868 G.memleak_value = l;
7870 l -= G.memleak_value;
7877 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7882 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7885 return EXIT_SUCCESS;
7888 static int FAST_FUNC builtin_read(char **argv)
7897 /* "!": do not abort on errors.
7898 * Option string must start with "sr" to match BUILTIN_READ_xxx
7900 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
7901 if (read_flags == (uint32_t)-1)
7902 return EXIT_FAILURE;
7905 r = shell_builtin_read(set_local_var_from_halves,
7907 get_local_var_value("IFS"), /* can be NULL */
7915 if ((uintptr_t)r > 1) {
7916 bb_error_msg("%s", r);
7917 r = (char*)(uintptr_t)1;
7920 return (uintptr_t)r;
7923 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7924 * built-in 'set' handler
7926 * set [-abCefhmnuvx] [-o option] [argument...]
7927 * set [+abCefhmnuvx] [+o option] [argument...]
7928 * set -- [argument...]
7931 * Implementations shall support the options in both their hyphen and
7932 * plus-sign forms. These options can also be specified as options to sh.
7934 * Write out all variables and their values: set
7935 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7936 * Turn on the -x and -v options: set -xv
7937 * Unset all positional parameters: set --
7938 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7939 * Set the positional parameters to the expansion of x, even if x expands
7940 * with a leading '-' or '+': set -- $x
7942 * So far, we only support "set -- [argument...]" and some of the short names.
7944 static int FAST_FUNC builtin_set(char **argv)
7947 char **pp, **g_argv;
7948 char *arg = *++argv;
7952 for (e = G.top_var; e; e = e->next)
7954 return EXIT_SUCCESS;
7958 if (!strcmp(arg, "--")) {
7962 if (arg[0] != '+' && arg[0] != '-')
7964 for (n = 1; arg[n]; ++n)
7965 if (set_mode(arg[0], arg[n]))
7967 } while ((arg = *++argv) != NULL);
7968 /* Now argv[0] is 1st argument */
7971 return EXIT_SUCCESS;
7974 /* NB: G.global_argv[0] ($0) is never freed/changed */
7975 g_argv = G.global_argv;
7976 if (G.global_args_malloced) {
7982 G.global_args_malloced = 1;
7983 pp = xzalloc(sizeof(pp[0]) * 2);
7984 pp[0] = g_argv[0]; /* retain $0 */
7987 /* This realloc's G.global_argv */
7988 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7995 return EXIT_SUCCESS;
7997 /* Nothing known, so abort */
7999 bb_error_msg("set: %s: invalid option", arg);
8000 return EXIT_FAILURE;
8003 static int FAST_FUNC builtin_shift(char **argv)
8006 argv = skip_dash_dash(argv);
8010 if (n >= 0 && n < G.global_argc) {
8011 if (G.global_args_malloced) {
8014 free(G.global_argv[m++]);
8017 memmove(&G.global_argv[1], &G.global_argv[n+1],
8018 G.global_argc * sizeof(G.global_argv[0]));
8019 return EXIT_SUCCESS;
8021 return EXIT_FAILURE;
8024 static int FAST_FUNC builtin_source(char **argv)
8026 char *arg_path, *filename;
8029 #if ENABLE_HUSH_FUNCTIONS
8033 argv = skip_dash_dash(argv);
8036 /* bash says: "bash: .: filename argument required" */
8037 return 2; /* bash compat */
8040 if (!strchr(filename, '/')) {
8041 arg_path = find_in_path(filename);
8043 filename = arg_path;
8045 input = fopen_or_warn(filename, "r");
8048 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8049 return EXIT_FAILURE;
8051 close_on_exec_on(fileno(input));
8053 #if ENABLE_HUSH_FUNCTIONS
8054 sv_flg = G.flag_return_in_progress;
8055 /* "we are inside sourced file, ok to use return" */
8056 G.flag_return_in_progress = -1;
8058 save_and_replace_G_args(&sv, argv);
8060 parse_and_run_file(input);
8063 restore_G_args(&sv, argv);
8064 #if ENABLE_HUSH_FUNCTIONS
8065 G.flag_return_in_progress = sv_flg;
8068 return G.last_exitcode;
8071 static int FAST_FUNC builtin_umask(char **argv)
8077 argv = skip_dash_dash(argv);
8079 mode_t old_mask = mask;
8082 rc = bb_parse_mode(argv[0], &mask);
8087 * bash: umask: 'q': invalid symbolic mode operator
8088 * bash: umask: 999: octal number out of range
8090 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8095 printf("%04o\n", (unsigned) mask);
8096 /* fall through and restore mask which we set to 0 */
8100 return !rc; /* rc != 0 - success */
8103 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8104 static int FAST_FUNC builtin_unset(char **argv)
8109 /* "!": do not abort on errors */
8110 /* "+": stop at 1st non-option */
8111 opts = getopt32(argv, "!+vf");
8112 if (opts == (unsigned)-1)
8113 return EXIT_FAILURE;
8115 bb_error_msg("unset: -v and -f are exclusive");
8116 return EXIT_FAILURE;
8122 if (!(opts & 2)) { /* not -f */
8123 if (unset_local_var(*argv)) {
8124 /* unset <nonexistent_var> doesn't fail.
8125 * Error is when one tries to unset RO var.
8126 * Message was printed by unset_local_var. */
8130 #if ENABLE_HUSH_FUNCTIONS
8140 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8141 static int FAST_FUNC builtin_wait(char **argv)
8143 int ret = EXIT_SUCCESS;
8146 argv = skip_dash_dash(argv);
8147 if (argv[0] == NULL) {
8148 /* Don't care about wait results */
8149 /* Note 1: must wait until there are no more children */
8150 /* Note 2: must be interruptible */
8152 * $ sleep 3 & sleep 6 & wait
8157 * $ sleep 3 & sleep 6 & wait
8161 * ^C <-- after ~4 sec from keyboard
8164 sigaddset(&G.blocked_set, SIGCHLD);
8165 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8168 if (errno == ECHILD)
8170 /* Wait for SIGCHLD or any other signal of interest */
8171 /* sigtimedwait with infinite timeout: */
8172 sig = sigwaitinfo(&G.blocked_set, NULL);
8174 sig = check_and_run_traps(sig);
8175 if (sig && sig != SIGCHLD) { /* see note 2 */
8181 sigdelset(&G.blocked_set, SIGCHLD);
8182 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8186 /* This is probably buggy wrt interruptible-ness */
8188 pid_t pid = bb_strtou(*argv, NULL, 10);
8190 /* mimic bash message */
8191 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8192 return EXIT_FAILURE;
8194 if (waitpid(pid, &status, 0) == pid) {
8195 if (WIFSIGNALED(status))
8196 ret = 128 + WTERMSIG(status);
8197 else if (WIFEXITED(status))
8198 ret = WEXITSTATUS(status);
8202 bb_perror_msg("wait %s", *argv);
8211 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8212 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8215 def = bb_strtou(argv[1], NULL, 10);
8216 if (errno || def < def_min || argv[2]) {
8217 bb_error_msg("%s: bad arguments", argv[0]);
8225 #if ENABLE_HUSH_LOOPS
8226 static int FAST_FUNC builtin_break(char **argv)
8229 if (G.depth_of_loop == 0) {
8230 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8231 return EXIT_SUCCESS; /* bash compat */
8233 G.flag_break_continue++; /* BC_BREAK = 1 */
8235 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8236 if (depth == UINT_MAX)
8237 G.flag_break_continue = BC_BREAK;
8238 if (G.depth_of_loop < depth)
8239 G.depth_break_continue = G.depth_of_loop;
8241 return EXIT_SUCCESS;
8244 static int FAST_FUNC builtin_continue(char **argv)
8246 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8247 return builtin_break(argv);
8251 #if ENABLE_HUSH_FUNCTIONS
8252 static int FAST_FUNC builtin_return(char **argv)
8256 if (G.flag_return_in_progress != -1) {
8257 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8258 return EXIT_FAILURE; /* bash compat */
8261 G.flag_return_in_progress = 1;
8264 * out of range: wraps around at 256, does not error out
8265 * non-numeric param:
8266 * f() { false; return qwe; }; f; echo $?
8267 * bash: return: qwe: numeric argument required <== we do this
8268 * 255 <== we also do this
8270 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);