1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
45 * Bash stuff (optionally enabled):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
51 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
52 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
53 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
55 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
56 * This is exactly equivalent to let "expression".
59 * grep for "TODO" and fix (some of them are easy)
61 * special variables (PWD etc)
62 * follow IFS rules more precisely, including update semantics
63 * export builtin should be special, its arguments are assignments
64 * and therefore expansion of them should be "one-word" expansion:
65 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
67 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
68 * ls: cannot access i=a: No such file or directory
69 * ls: cannot access b: No such file or directory
70 * Note1: same applies to local builtin.
71 * Note2: bash 3.2.33(1) does this only if export word itself
73 * $ export i=`echo 'aaa bbb'`; echo "$i"
75 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
78 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
80 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
82 /* #include <dmalloc.h> */
89 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
94 #define LEAK_HUNTING 0
95 #define BUILD_AS_NOMMU 0
96 /* Enable/disable sanity checks. Ok to enable in production,
97 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
98 * Keeping 1 for now even in released versions.
101 /* Slightly bigger (+200 bytes), but faster hush.
102 * So far it only enables a trick with counting SIGCHLDs and forks,
103 * which allows us to do fewer waitpid's.
104 * (we can detect a case where neither forks were done nor SIGCHLDs happened
105 * and therefore waitpid will return the same result as last time)
107 #define ENABLE_HUSH_FAST 0
112 # undef USE_FOR_NOMMU
115 # define USE_FOR_NOMMU(...) __VA_ARGS__
116 # define USE_FOR_MMU(...)
119 #if defined SINGLE_APPLET_MAIN
120 /* STANDALONE does not make sense, and won't compile */
121 # undef CONFIG_FEATURE_SH_STANDALONE
122 # undef ENABLE_FEATURE_SH_STANDALONE
123 # undef IF_FEATURE_SH_STANDALONE
124 # define IF_FEATURE_SH_STANDALONE(...)
125 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
126 # define ENABLE_FEATURE_SH_STANDALONE 0
129 #if !ENABLE_HUSH_INTERACTIVE
130 # undef ENABLE_FEATURE_EDITING
131 # define ENABLE_FEATURE_EDITING 0
132 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
133 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
136 /* Do we support ANY keywords? */
137 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
138 # define HAS_KEYWORDS 1
139 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
140 # define IF_HAS_NO_KEYWORDS(...)
142 # define HAS_KEYWORDS 0
143 # define IF_HAS_KEYWORDS(...)
144 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
147 /* If you comment out one of these below, it will be #defined later
148 * to perform debug printfs to stderr: */
149 #define debug_printf(...) do {} while (0)
150 /* Finer-grained debug switches */
151 #define debug_printf_parse(...) do {} while (0)
152 #define debug_print_tree(a, b) do {} while (0)
153 #define debug_printf_exec(...) do {} while (0)
154 #define debug_printf_env(...) do {} while (0)
155 #define debug_printf_jobs(...) do {} while (0)
156 #define debug_printf_expand(...) do {} while (0)
157 #define debug_printf_glob(...) do {} while (0)
158 #define debug_printf_list(...) do {} while (0)
159 #define debug_printf_subst(...) do {} while (0)
160 #define debug_printf_clean(...) do {} while (0)
162 #define ERR_PTR ((void*)(long)1)
164 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
166 #define SPECIAL_VAR_SYMBOL 3
170 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
172 /* This supports saving pointers malloced in vfork child,
173 * to be freed in the parent.
176 typedef struct nommu_save_t {
178 struct variable *old_vars;
180 char **argv_from_re_execing;
184 typedef enum reserved_style {
193 #if ENABLE_HUSH_LOOPS
200 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
205 /* three pseudo-keywords support contrived "case" syntax: */
206 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
207 RES_MATCH , /* "word)" */
208 RES_CASE_BODY, /* "this command is inside CASE" */
215 typedef struct o_string {
217 int length; /* position where data is appended */
219 /* Protect newly added chars against globbing
220 * (by prepending \ to *, ?, [, \) */
223 /* At least some part of the string was inside '' or "",
224 * possibly empty one: word"", wo''rd etc. */
226 smallint has_empty_slot;
227 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
230 MAYBE_ASSIGNMENT = 0,
231 DEFINITELY_ASSIGNMENT = 1,
233 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
235 /* Used for initialization: o_string foo = NULL_O_STRING; */
236 #define NULL_O_STRING { NULL }
238 /* I can almost use ordinary FILE*. Is open_memstream() universally
239 * available? Where is it documented? */
240 typedef struct in_str {
242 /* eof_flag=1: last char in ->p is really an EOF */
243 char eof_flag; /* meaningless if ->p == NULL */
245 #if ENABLE_HUSH_INTERACTIVE
247 smallint promptmode; /* 0: PS1, 1: PS2 */
250 int (*get) (struct in_str *) FAST_FUNC;
251 int (*peek) (struct in_str *) FAST_FUNC;
253 #define i_getch(input) ((input)->get(input))
254 #define i_peek(input) ((input)->peek(input))
256 /* The descrip member of this structure is only used to make
257 * debugging output pretty */
258 static const struct {
260 signed char default_fd;
263 { O_RDONLY, 0, "<" },
264 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
265 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
266 { O_CREAT|O_RDWR, 1, "<>" },
267 { O_RDONLY, 0, "<<" },
268 /* Should not be needed. Bogus default_fd helps in debugging */
269 /* { O_RDONLY, 77, "<<" }, */
272 struct redir_struct {
273 struct redir_struct *next;
274 char *rd_filename; /* filename */
275 int rd_fd; /* fd to redirect */
276 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
278 smallint rd_type; /* (enum redir_type) */
279 /* note: for heredocs, rd_filename contains heredoc delimiter,
280 * and subsequently heredoc itself; and rd_dup is a bitmask:
281 * bit 0: do we need to trim leading tabs?
282 * bit 1: is heredoc quoted (<<'delim' syntax) ?
285 typedef enum redir_type {
287 REDIRECT_OVERWRITE = 1,
290 REDIRECT_HEREDOC = 4,
291 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
294 REDIRFD_SYNTAX_ERR = -2,
295 REDIRFD_TO_FILE = -1,
296 /* otherwise, rd_fd is redirected to rd_dup */
298 HEREDOC_SKIPTABS = 1,
304 pid_t pid; /* 0 if exited */
305 int assignment_cnt; /* how many argv[i] are assignments? */
306 smallint is_stopped; /* is the command currently running? */
307 smallint cmd_type; /* CMD_xxx */
309 #define CMD_SUBSHELL 1
311 /* used for "[[ EXPR ]]" */
312 #if ENABLE_HUSH_BASH_COMPAT
313 # define CMD_SINGLEWORD_NOGLOB 2
316 /* used for "export noglob=* glob* a=`echo a b`" */
317 //#define CMD_SINGLEWORD_NOGLOB_COND 3
318 // It is hard to implement correctly, it adds significant amounts of tricky code,
319 // and all this is only useful for really obscure export statements
320 // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
321 // guards the code which implements it, but I have doubts it works
322 // in all cases (especially with mixed globbed/non-globbed arguments)
324 #if ENABLE_HUSH_FUNCTIONS
325 # define CMD_FUNCDEF 3
328 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
331 char *group_as_string;
333 #if ENABLE_HUSH_FUNCTIONS
334 struct function *child_func;
335 /* This field is used to prevent a bug here:
336 * while...do f1() {a;}; f1; f1() {b;}; f1; done
337 * When we execute "f1() {a;}" cmd, we create new function and clear
338 * cmd->group, cmd->group_as_string, cmd->argv[0].
339 * When we execute "f1() {b;}", we notice that f1 exists,
340 * and that its "parent cmd" struct is still "alive",
341 * we put those fields back into cmd->xxx
342 * (struct function has ->parent_cmd ptr to facilitate that).
343 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
344 * Without this trick, loop would execute a;b;b;b;...
345 * instead of correct sequence a;b;a;b;...
346 * When command is freed, it severs the link
347 * (sets ->child_func->parent_cmd to NULL).
350 char **argv; /* command name and arguments */
351 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
352 * and on execution these are substituted with their values.
353 * Substitution can make _several_ words out of one argv[n]!
354 * Example: argv[0]=='.^C*^C.' here: echo .$*.
355 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
357 struct redir_struct *redirects; /* I/O redirections */
359 /* Is there anything in this command at all? */
360 #define IS_NULL_CMD(cmd) \
361 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
366 int num_cmds; /* total number of commands in pipe */
367 int alive_cmds; /* number of commands running (not exited) */
368 int stopped_cmds; /* number of commands alive, but stopped */
370 int jobid; /* job number */
371 pid_t pgrp; /* process group ID for the job */
372 char *cmdtext; /* name of job */
374 struct command *cmds; /* array of commands in pipe */
375 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
376 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
377 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
379 typedef enum pipe_style {
385 /* Is there anything in this pipe at all? */
386 #define IS_NULL_PIPE(pi) \
387 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
389 /* This holds pointers to the various results of parsing */
390 struct parse_context {
391 /* linked list of pipes */
392 struct pipe *list_head;
393 /* last pipe (being constructed right now) */
395 /* last command in pipe (being constructed right now) */
396 struct command *command;
397 /* last redirect in command->redirects list */
398 struct redir_struct *pending_redirect;
404 smallint ctx_inverted; /* "! cmd | cmd" */
406 smallint ctx_dsemicolon; /* ";;" seen */
408 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
410 /* group we are enclosed in:
411 * example: "if pipe1; pipe2; then pipe3; fi"
412 * when we see "if" or "then", we malloc and copy current context,
413 * and make ->stack point to it. then we parse pipeN.
414 * when closing "then" / fi" / whatever is found,
415 * we move list_head into ->stack->command->group,
416 * copy ->stack into current context, and delete ->stack.
417 * (parsing of { list } and ( list ) doesn't use this method)
419 struct parse_context *stack;
423 /* On program start, environ points to initial environment.
424 * putenv adds new pointers into it, unsetenv removes them.
425 * Neither of these (de)allocates the strings.
426 * setenv allocates new strings in malloc space and does putenv,
427 * and thus setenv is unusable (leaky) for shell's purposes */
428 #define setenv(...) setenv_is_leaky_dont_use()
430 struct variable *next;
431 char *varstr; /* points to "name=" portion */
432 #if ENABLE_HUSH_LOCAL
433 unsigned func_nest_level;
435 int max_len; /* if > 0, name is part of initial env; else name is malloced */
436 smallint flg_export; /* putenv should be done on this var */
437 smallint flg_read_only;
445 #if ENABLE_HUSH_FUNCTIONS
447 struct function *next;
449 struct command *parent_cmd;
452 char *body_as_string;
458 /* "Globals" within this file */
459 /* Sorted roughly by size (smaller offsets == smaller code) */
461 /* interactive_fd != 0 means we are an interactive shell.
462 * If we are, then saved_tty_pgrp can also be != 0, meaning
463 * that controlling tty is available. With saved_tty_pgrp == 0,
464 * job control still works, but terminal signals
465 * (^C, ^Z, ^Y, ^\) won't work at all, and background
466 * process groups can only be created with "cmd &".
467 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
468 * to give tty to the foreground process group,
469 * and will take it back when the group is stopped (^Z)
472 #if ENABLE_HUSH_INTERACTIVE
473 /* 'interactive_fd' is a fd# open to ctty, if we have one
474 * _AND_ if we decided to act interactively */
478 # define G_interactive_fd (G.interactive_fd)
480 # define G_interactive_fd 0
482 #if ENABLE_FEATURE_EDITING
483 line_input_t *line_input_state;
490 pid_t saved_tty_pgrp;
491 struct pipe *job_list;
492 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
494 # define G_saved_tty_pgrp 0
496 smallint flag_SIGINT;
497 #if ENABLE_HUSH_LOOPS
498 smallint flag_break_continue;
500 #if ENABLE_HUSH_FUNCTIONS
501 /* 0: outside of a function (or sourced file)
502 * -1: inside of a function, ok to use return builtin
503 * 1: return is invoked, skip all till end of func
505 smallint flag_return_in_progress;
508 smallint exiting; /* used to prevent EXIT trap recursion */
509 /* These four support $?, $#, and $1 */
510 smalluint last_exitcode;
511 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
512 smalluint global_args_malloced;
513 /* how many non-NULL argv's we have. NB: $# + 1 */
517 char *argv0_for_re_execing;
519 #if ENABLE_HUSH_LOOPS
520 unsigned depth_break_continue;
521 unsigned depth_of_loop;
525 struct variable *top_var; /* = &G.shell_ver (set in main()) */
526 struct variable shell_ver;
527 #if ENABLE_HUSH_FUNCTIONS
528 struct function *top_func;
529 # if ENABLE_HUSH_LOCAL
530 struct variable **shadowed_vars_pp;
531 unsigned func_nest_level;
534 /* Signal and trap handling */
536 unsigned count_SIGCHLD;
537 unsigned handled_SIGCHLD;
538 smallint we_have_children;
540 /* which signals have non-DFL handler (even with no traps set)? */
541 unsigned non_DFL_mask;
542 char **traps; /* char *traps[NSIG] */
543 sigset_t blocked_set;
544 sigset_t inherited_set;
546 unsigned long memleak_value;
549 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
551 #define G (*ptr_to_globals)
552 /* Not #defining name to G.name - this quickly gets unwieldy
553 * (too many defines). Also, I actually prefer to see when a variable
554 * is global, thus "G." prefix is a useful hint */
555 #define INIT_G() do { \
556 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
560 /* Function prototypes for builtins */
561 static int builtin_cd(char **argv) FAST_FUNC;
562 static int builtin_echo(char **argv) FAST_FUNC;
563 static int builtin_eval(char **argv) FAST_FUNC;
564 static int builtin_exec(char **argv) FAST_FUNC;
565 static int builtin_exit(char **argv) FAST_FUNC;
566 static int builtin_export(char **argv) FAST_FUNC;
568 static int builtin_fg_bg(char **argv) FAST_FUNC;
569 static int builtin_jobs(char **argv) FAST_FUNC;
572 static int builtin_help(char **argv) FAST_FUNC;
574 #if ENABLE_HUSH_LOCAL
575 static int builtin_local(char **argv) FAST_FUNC;
578 static int builtin_memleak(char **argv) FAST_FUNC;
580 static int builtin_pwd(char **argv) FAST_FUNC;
581 static int builtin_read(char **argv) FAST_FUNC;
582 static int builtin_set(char **argv) FAST_FUNC;
583 static int builtin_shift(char **argv) FAST_FUNC;
584 static int builtin_source(char **argv) FAST_FUNC;
585 static int builtin_test(char **argv) FAST_FUNC;
586 static int builtin_trap(char **argv) FAST_FUNC;
587 static int builtin_type(char **argv) FAST_FUNC;
588 static int builtin_true(char **argv) FAST_FUNC;
589 static int builtin_umask(char **argv) FAST_FUNC;
590 static int builtin_unset(char **argv) FAST_FUNC;
591 static int builtin_wait(char **argv) FAST_FUNC;
592 #if ENABLE_HUSH_LOOPS
593 static int builtin_break(char **argv) FAST_FUNC;
594 static int builtin_continue(char **argv) FAST_FUNC;
596 #if ENABLE_HUSH_FUNCTIONS
597 static int builtin_return(char **argv) FAST_FUNC;
600 /* Table of built-in functions. They can be forked or not, depending on
601 * context: within pipes, they fork. As simple commands, they do not.
602 * When used in non-forking context, they can change global variables
603 * in the parent shell process. If forked, of course they cannot.
604 * For example, 'unset foo | whatever' will parse and run, but foo will
605 * still be set at the end. */
606 struct built_in_command {
608 int (*function)(char **argv) FAST_FUNC;
611 # define BLTIN(cmd, func, help) { cmd, func, help }
613 # define BLTIN(cmd, func, help) { cmd, func }
617 static const struct built_in_command bltins1[] = {
618 BLTIN("." , builtin_source , "Run commands in a file"),
619 BLTIN(":" , builtin_true , NULL),
621 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
623 #if ENABLE_HUSH_LOOPS
624 BLTIN("break" , builtin_break , "Exit from a loop"),
626 BLTIN("cd" , builtin_cd , "Change directory"),
627 #if ENABLE_HUSH_LOOPS
628 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
630 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
631 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
632 BLTIN("exit" , builtin_exit , "Exit"),
633 BLTIN("export" , builtin_export , "Set environment variables"),
635 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
638 BLTIN("help" , builtin_help , NULL),
641 BLTIN("jobs" , builtin_jobs , "List jobs"),
643 #if ENABLE_HUSH_LOCAL
644 BLTIN("local" , builtin_local , "Set local variables"),
647 BLTIN("memleak" , builtin_memleak , NULL),
649 BLTIN("read" , builtin_read , "Input into variable"),
650 #if ENABLE_HUSH_FUNCTIONS
651 BLTIN("return" , builtin_return , "Return from a function"),
653 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
654 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
655 BLTIN("trap" , builtin_trap , "Trap signals"),
656 BLTIN("type" , builtin_type , "Write a description of command type"),
657 // BLTIN("ulimit" , builtin_ulimit , "Control resource limits"),
658 BLTIN("umask" , builtin_umask , "Set file creation mask"),
659 BLTIN("unset" , builtin_unset , "Unset variables"),
660 BLTIN("wait" , builtin_wait , "Wait for process"),
662 /* For now, echo and test are unconditionally enabled.
663 * Maybe make it configurable? */
664 static const struct built_in_command bltins2[] = {
665 BLTIN("[" , builtin_test , NULL),
666 BLTIN("echo" , builtin_echo , NULL),
667 BLTIN("pwd" , builtin_pwd , NULL),
668 BLTIN("test" , builtin_test , NULL),
675 /* prevent disasters with G.debug_indent < 0 */
676 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
677 # define debug_enter() (G.debug_indent++)
678 # define debug_leave() (G.debug_indent--)
680 # define indent() ((void)0)
681 # define debug_enter() ((void)0)
682 # define debug_leave() ((void)0)
686 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
689 #ifndef debug_printf_parse
690 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
693 #ifndef debug_printf_exec
694 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
697 #ifndef debug_printf_env
698 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
701 #ifndef debug_printf_jobs
702 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
703 # define DEBUG_JOBS 1
705 # define DEBUG_JOBS 0
708 #ifndef debug_printf_expand
709 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
710 # define DEBUG_EXPAND 1
712 # define DEBUG_EXPAND 0
715 #ifndef debug_printf_glob
716 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
717 # define DEBUG_GLOB 1
719 # define DEBUG_GLOB 0
722 #ifndef debug_printf_list
723 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
726 #ifndef debug_printf_subst
727 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
730 #ifndef debug_printf_clean
731 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
732 # define DEBUG_CLEAN 1
734 # define DEBUG_CLEAN 0
738 static void debug_print_strings(const char *prefix, char **vv)
741 fprintf(stderr, "%s:\n", prefix);
743 fprintf(stderr, " '%s'\n", *vv++);
746 # define debug_print_strings(prefix, vv) ((void)0)
750 /* Leak hunting. Use hush_leaktool.sh for post-processing.
753 static void *xxmalloc(int lineno, size_t size)
755 void *ptr = xmalloc((size + 0xff) & ~0xff);
756 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
759 static void *xxrealloc(int lineno, void *ptr, size_t size)
761 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
762 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
765 static char *xxstrdup(int lineno, const char *str)
767 char *ptr = xstrdup(str);
768 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
771 static void xxfree(void *ptr)
773 fdprintf(2, "free %p\n", ptr);
776 #define xmalloc(s) xxmalloc(__LINE__, s)
777 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
778 #define xstrdup(s) xxstrdup(__LINE__, s)
779 #define free(p) xxfree(p)
783 /* Syntax and runtime errors. They always abort scripts.
784 * In interactive use they usually discard unparsed and/or unexecuted commands
785 * and return to the prompt.
786 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
789 # define die_if_script(lineno, fmt...) die_if_script(fmt)
790 # define syntax_error(lineno, msg) syntax_error(msg)
791 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
792 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
793 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
794 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
797 static void die_if_script(unsigned lineno, const char *fmt, ...)
802 bb_error_msg("hush.c:%u", lineno);
805 bb_verror_msg(fmt, p, NULL);
807 if (!G_interactive_fd)
811 static void syntax_error(unsigned lineno, const char *msg)
814 die_if_script(lineno, "syntax error: %s", msg);
816 die_if_script(lineno, "syntax error", NULL);
819 static void syntax_error_at(unsigned lineno, const char *msg)
821 die_if_script(lineno, "syntax error at '%s'", msg);
824 static void syntax_error_unterm_str(unsigned lineno, const char *s)
826 die_if_script(lineno, "syntax error: unterminated %s", s);
829 /* It so happens that all such cases are totally fatal
830 * even if shell is interactive: EOF while looking for closing
831 * delimiter. There is nowhere to read stuff from after that,
832 * it's EOF! The only choice is to terminate.
834 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
835 static void syntax_error_unterm_ch(unsigned lineno, char ch)
837 char msg[2] = { ch, '\0' };
838 syntax_error_unterm_str(lineno, msg);
842 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
847 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
851 # undef die_if_script
853 # undef syntax_error_at
854 # undef syntax_error_unterm_ch
855 # undef syntax_error_unterm_str
856 # undef syntax_error_unexpected_ch
858 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
859 # define syntax_error(msg) syntax_error(__LINE__, msg)
860 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
861 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
862 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
863 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
867 #if ENABLE_HUSH_INTERACTIVE
868 static void cmdedit_update_prompt(void);
870 # define cmdedit_update_prompt() ((void)0)
876 static int glob_needed(const char *s)
881 if (*s == '*' || *s == '[' || *s == '?')
888 static int is_well_formed_var_name(const char *s, char terminator)
890 if (!s || !(isalpha(*s) || *s == '_'))
893 while (isalnum(*s) || *s == '_')
895 return *s == terminator;
898 /* Replace each \x with x in place, return ptr past NUL. */
899 static char *unbackslash(char *src)
905 if ((*dst++ = *src++) == '\0')
911 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
932 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
933 v[count1 + count2] = NULL;
936 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
940 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
942 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
943 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
946 #define add_strings_to_strings(strings, add, need_to_dup) \
947 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
950 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
951 static char **add_string_to_strings(char **strings, char *add)
956 return add_strings_to_strings(strings, v, /*dup:*/ 0);
959 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
961 char **ptr = add_string_to_strings(strings, add);
962 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
965 #define add_string_to_strings(strings, add) \
966 xx_add_string_to_strings(__LINE__, strings, add)
969 static void free_strings(char **strings)
984 /* Helpers for setting new $n and restoring them back
986 typedef struct save_arg_t {
990 smallint sv_g_malloced;
993 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
997 sv->sv_argv0 = argv[0];
998 sv->sv_g_argv = G.global_argv;
999 sv->sv_g_argc = G.global_argc;
1000 sv->sv_g_malloced = G.global_args_malloced;
1002 argv[0] = G.global_argv[0]; /* retain $0 */
1003 G.global_argv = argv;
1004 G.global_args_malloced = 0;
1012 static void restore_G_args(save_arg_t *sv, char **argv)
1016 if (G.global_args_malloced) {
1017 /* someone ran "set -- arg1 arg2 ...", undo */
1019 while (*++pp) /* note: does not free $0 */
1021 free(G.global_argv);
1023 argv[0] = sv->sv_argv0;
1024 G.global_argv = sv->sv_g_argv;
1025 G.global_argc = sv->sv_g_argc;
1026 G.global_args_malloced = sv->sv_g_malloced;
1030 /* Basic theory of signal handling in shell
1031 * ========================================
1032 * This does not describe what hush does, rather, it is current understanding
1033 * what it _should_ do. If it doesn't, it's a bug.
1034 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1036 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1037 * is finished or backgrounded. It is the same in interactive and
1038 * non-interactive shells, and is the same regardless of whether
1039 * a user trap handler is installed or a shell special one is in effect.
1040 * ^C or ^Z from keyboard seem to execute "at once" because it usually
1041 * backgrounds (i.e. stops) or kills all members of currently running
1044 * Wait builtin in interruptible by signals for which user trap is set
1045 * or by SIGINT in interactive shell.
1047 * Trap handlers will execute even within trap handlers. (right?)
1049 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1051 * If job control is off, backgrounded commands ("cmd &")
1052 * have SIGINT, SIGQUIT set to SIG_IGN.
1054 * Commands which are run in command substitution ("`cmd`")
1055 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1057 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1058 * by the shell from its parent.
1060 * Signals which differ from SIG_DFL action
1061 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1064 * SIGTERM (interactive): ignore
1065 * SIGHUP (interactive):
1066 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1067 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1068 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1069 * that all pipe members are stopped. Try this in bash:
1070 * while :; do :; done - ^Z does not background it
1071 * (while :; do :; done) - ^Z backgrounds it
1072 * SIGINT (interactive): wait for last pipe, ignore the rest
1073 * of the command line, show prompt. NB: ^C does not send SIGINT
1074 * to interactive shell while shell is waiting for a pipe,
1075 * since shell is bg'ed (is not in foreground process group).
1076 * Example 1: this waits 5 sec, but does not execute ls:
1077 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1078 * Example 2: this does not wait and does not execute ls:
1079 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1080 * Example 3: this does not wait 5 sec, but executes ls:
1081 * "sleep 5; ls -l" + press ^C
1083 * (What happens to signals which are IGN on shell start?)
1084 * (What happens with signal mask on shell start?)
1086 * Implementation in hush
1087 * ======================
1088 * We use in-kernel pending signal mask to determine which signals were sent.
1089 * We block all signals which we don't want to take action immediately,
1090 * i.e. we block all signals which need to have special handling as described
1091 * above, and all signals which have traps set.
1092 * After each pipe execution, we extract any pending signals via sigtimedwait()
1095 * unsigned non_DFL_mask: a mask of such "special" signals
1096 * sigset_t blocked_set: current blocked signal set
1099 * clear bit in blocked_set unless it is also in non_DFL_mask
1100 * "trap 'cmd' SIGxxx":
1101 * set bit in blocked_set (even if 'cmd' is '')
1102 * after [v]fork, if we plan to be a shell:
1103 * unblock signals with special interactive handling
1104 * (child shell is not interactive),
1105 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1106 * after [v]fork, if we plan to exec:
1107 * POSIX says pending signal mask is cleared in child - no need to clear it.
1108 * Restore blocked signal set to one inherited by shell just prior to exec.
1110 * Note: as a result, we do not use signal handlers much. The only uses
1111 * are to count SIGCHLDs
1112 * and to restore tty pgrp on signal-induced exit.
1115 SPECIAL_INTERACTIVE_SIGS = 0
1120 SPECIAL_JOB_SIGS = 0
1128 #if ENABLE_HUSH_FAST
1129 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1132 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1138 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1139 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1140 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1141 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1143 /* Restores tty foreground process group, and exits.
1144 * May be called as signal handler for fatal signal
1145 * (will resend signal to itself, producing correct exit state)
1146 * or called directly with -EXITCODE.
1147 * We also call it if xfunc is exiting. */
1148 static void sigexit(int sig) NORETURN;
1149 static void sigexit(int sig)
1151 /* Disable all signals: job control, SIGPIPE, etc. */
1152 sigprocmask_allsigs(SIG_BLOCK);
1154 /* Careful: we can end up here after [v]fork. Do not restore
1155 * tty pgrp then, only top-level shell process does that */
1156 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1157 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1159 /* Not a signal, just exit */
1163 kill_myself_with_sig(sig); /* does not return */
1167 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1168 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1172 /* Restores tty foreground process group, and exits. */
1173 static void hush_exit(int exitcode) NORETURN;
1174 static void hush_exit(int exitcode)
1176 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1177 /* Prevent recursion:
1178 * trap "echo Hi; exit" EXIT; exit
1180 char *argv[] = { NULL, G.traps[0], NULL };
1188 fflush(NULL); /* flush all streams */
1189 sigexit(- (exitcode & 0xff));
1195 static int check_and_run_traps(int sig)
1197 static const struct timespec zero_timespec = { 0, 0 };
1198 smalluint save_rcode;
1204 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1209 if (G.traps && G.traps[sig]) {
1210 if (G.traps[sig][0]) {
1211 /* We have user-defined handler */
1212 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1213 save_rcode = G.last_exitcode;
1216 G.last_exitcode = save_rcode;
1217 } /* else: "" trap, ignoring signal */
1220 /* not a trap: special action */
1222 #if ENABLE_HUSH_FAST
1225 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1229 /* Builtin was ^C'ed, make it look prettier: */
1236 /* bash is observed to signal whole process groups,
1237 * not individual processes */
1238 for (job = G.job_list; job; job = job->next) {
1241 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1242 if (kill(- job->pgrp, SIGHUP) == 0)
1243 kill(- job->pgrp, SIGCONT);
1248 default: /* ignored: */
1249 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1257 static const char *get_cwd(int force)
1259 if (force || G.cwd == NULL) {
1260 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1261 * we must not try to free(bb_msg_unknown) */
1262 if (G.cwd == bb_msg_unknown)
1264 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1266 G.cwd = bb_msg_unknown;
1273 * Shell and environment variable support
1275 static struct variable **get_ptr_to_local_var(const char *name)
1277 struct variable **pp;
1278 struct variable *cur;
1283 while ((cur = *pp) != NULL) {
1284 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1291 static struct variable *get_local_var(const char *name)
1293 struct variable **pp = get_ptr_to_local_var(name);
1299 static const char *get_local_var_value(const char *name)
1301 struct variable **pp = get_ptr_to_local_var(name);
1303 return strchr((*pp)->varstr, '=') + 1;
1307 /* str holds "NAME=VAL" and is expected to be malloced.
1308 * We take ownership of it.
1310 * 0: do not change export flag
1311 * (if creating new variable, flag will be 0)
1312 * 1: set export flag and putenv the variable
1313 * -1: clear export flag and unsetenv the variable
1314 * flg_read_only is set only when we handle -R var=val
1316 #if !BB_MMU && ENABLE_HUSH_LOCAL
1317 /* all params are used */
1318 #elif BB_MMU && ENABLE_HUSH_LOCAL
1319 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1320 set_local_var(str, flg_export, local_lvl)
1321 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1322 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1323 set_local_var(str, flg_export)
1324 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1325 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1326 set_local_var(str, flg_export, flg_read_only)
1328 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1330 struct variable **var_pp;
1331 struct variable *cur;
1335 eq_sign = strchr(str, '=');
1336 if (!eq_sign) { /* not expected to ever happen? */
1341 name_len = eq_sign - str + 1; /* including '=' */
1342 var_pp = &G.top_var;
1343 while ((cur = *var_pp) != NULL) {
1344 if (strncmp(cur->varstr, str, name_len) != 0) {
1345 var_pp = &cur->next;
1348 /* We found an existing var with this name */
1349 if (cur->flg_read_only) {
1353 bb_error_msg("%s: readonly variable", str);
1357 if (flg_export == -1) { // "&& cur->flg_export" ?
1358 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1363 #if ENABLE_HUSH_LOCAL
1364 if (cur->func_nest_level < local_lvl) {
1365 /* New variable is declared as local,
1366 * and existing one is global, or local
1367 * from enclosing function.
1368 * Remove and save old one: */
1369 *var_pp = cur->next;
1370 cur->next = *G.shadowed_vars_pp;
1371 *G.shadowed_vars_pp = cur;
1372 /* bash 3.2.33(1) and exported vars:
1374 * # f() { local z=a; env | grep ^z; }
1380 if (cur->flg_export)
1385 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1390 if (cur->max_len != 0) {
1391 if (cur->max_len >= strlen(str)) {
1392 /* This one is from startup env, reuse space */
1393 strcpy(cur->varstr, str);
1397 /* max_len == 0 signifies "malloced" var, which we can
1398 * (and has to) free */
1402 goto set_str_and_exp;
1405 /* Not found - create new variable struct */
1406 cur = xzalloc(sizeof(*cur));
1407 #if ENABLE_HUSH_LOCAL
1408 cur->func_nest_level = local_lvl;
1410 cur->next = *var_pp;
1416 cur->flg_read_only = flg_read_only;
1419 if (flg_export == 1)
1420 cur->flg_export = 1;
1421 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1422 cmdedit_update_prompt();
1423 if (cur->flg_export) {
1424 if (flg_export == -1) {
1425 cur->flg_export = 0;
1426 /* unsetenv was already done */
1428 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1429 return putenv(cur->varstr);
1435 static int unset_local_var_len(const char *name, int name_len)
1437 struct variable *cur;
1438 struct variable **var_pp;
1441 return EXIT_SUCCESS;
1442 var_pp = &G.top_var;
1443 while ((cur = *var_pp) != NULL) {
1444 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1445 if (cur->flg_read_only) {
1446 bb_error_msg("%s: readonly variable", name);
1447 return EXIT_FAILURE;
1449 *var_pp = cur->next;
1450 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1451 bb_unsetenv(cur->varstr);
1452 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1453 cmdedit_update_prompt();
1457 return EXIT_SUCCESS;
1459 var_pp = &cur->next;
1461 return EXIT_SUCCESS;
1464 static int unset_local_var(const char *name)
1466 return unset_local_var_len(name, strlen(name));
1469 static void unset_vars(char **strings)
1477 const char *eq = strchrnul(*v, '=');
1478 unset_local_var_len(*v, (int)(eq - *v));
1484 #if ENABLE_SH_MATH_SUPPORT
1485 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1486 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1487 static char *endofname(const char *name)
1495 if (!is_in_name(*p))
1501 static void arith_set_local_var(const char *name, const char *val, int flags)
1503 /* arith code doesnt malloc space, so do it for it */
1504 char *var = xasprintf("%s=%s", name, val);
1505 set_local_var(var, flags, /*lvl:*/ 0, /*ro:*/ 0);
1511 * Helpers for "var1=val1 var2=val2 cmd" feature
1513 static void add_vars(struct variable *var)
1515 struct variable *next;
1519 var->next = G.top_var;
1521 if (var->flg_export) {
1522 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1523 putenv(var->varstr);
1525 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1531 static struct variable *set_vars_and_save_old(char **strings)
1534 struct variable *old = NULL;
1540 struct variable *var_p;
1541 struct variable **var_pp;
1544 eq = strchr(*s, '=');
1547 var_pp = get_ptr_to_local_var(*s);
1550 /* Remove variable from global linked list */
1552 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1553 *var_pp = var_p->next;
1554 /* Add it to returned list */
1558 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1569 static int FAST_FUNC static_get(struct in_str *i)
1578 static int FAST_FUNC static_peek(struct in_str *i)
1583 #if ENABLE_HUSH_INTERACTIVE
1585 static void cmdedit_update_prompt(void)
1587 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1588 G.PS1 = get_local_var_value("PS1");
1591 G.PS2 = get_local_var_value("PS2");
1599 static const char* setup_prompt_string(int promptmode)
1601 const char *prompt_str;
1602 debug_printf("setup_prompt_string %d ", promptmode);
1603 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1604 /* Set up the prompt */
1605 if (promptmode == 0) { /* PS1 */
1607 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1612 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1613 debug_printf("result '%s'\n", prompt_str);
1617 static void get_user_input(struct in_str *i)
1620 const char *prompt_str;
1622 prompt_str = setup_prompt_string(i->promptmode);
1623 #if ENABLE_FEATURE_EDITING
1624 /* Enable command line editing only while a command line
1625 * is actually being read */
1628 /* buglet: SIGINT will not make new prompt to appear _at once_,
1629 * only after <Enter>. (^C will work) */
1630 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1631 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1632 check_and_run_traps(0);
1633 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1634 i->eof_flag = (r < 0);
1635 if (i->eof_flag) { /* EOF/error detected */
1636 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1637 G.user_input_buf[1] = '\0';
1642 fputs(prompt_str, stdout);
1644 G.user_input_buf[0] = r = fgetc(i->file);
1645 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1646 //do we need check_and_run_traps(0)? (maybe only if stdin)
1647 } while (G.flag_SIGINT);
1648 i->eof_flag = (r == EOF);
1650 i->p = G.user_input_buf;
1653 #endif /* INTERACTIVE */
1655 /* This is the magic location that prints prompts
1656 * and gets data back from the user */
1657 static int FAST_FUNC file_get(struct in_str *i)
1661 /* If there is data waiting, eat it up */
1662 if (i->p && *i->p) {
1663 #if ENABLE_HUSH_INTERACTIVE
1667 if (i->eof_flag && !*i->p)
1669 /* note: ch is never NUL */
1671 /* need to double check i->file because we might be doing something
1672 * more complicated by now, like sourcing or substituting. */
1673 #if ENABLE_HUSH_INTERACTIVE
1674 if (G_interactive_fd && i->promptme && i->file == stdin) {
1677 } while (!*i->p); /* need non-empty line */
1678 i->promptmode = 1; /* PS2 */
1683 do ch = fgetc(i->file); while (ch == '\0');
1685 debug_printf("file_get: got '%c' %d\n", ch, ch);
1686 #if ENABLE_HUSH_INTERACTIVE
1693 /* All callers guarantee this routine will never
1694 * be used right after a newline, so prompting is not needed.
1696 static int FAST_FUNC file_peek(struct in_str *i)
1699 if (i->p && *i->p) {
1700 if (i->eof_flag && !i->p[1])
1703 /* note: ch is never NUL */
1705 do ch = fgetc(i->file); while (ch == '\0');
1706 i->eof_flag = (ch == EOF);
1707 i->peek_buf[0] = ch;
1708 i->peek_buf[1] = '\0';
1710 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1714 static void setup_file_in_str(struct in_str *i, FILE *f)
1716 i->peek = file_peek;
1718 #if ENABLE_HUSH_INTERACTIVE
1720 i->promptmode = 0; /* PS1 */
1726 static void setup_string_in_str(struct in_str *i, const char *s)
1728 i->peek = static_peek;
1729 i->get = static_get;
1730 #if ENABLE_HUSH_INTERACTIVE
1732 i->promptmode = 0; /* PS1 */
1742 #define B_CHUNK (32 * sizeof(char*))
1744 static void o_reset_to_empty_unquoted(o_string *o)
1752 static void o_free(o_string *o)
1755 memset(o, 0, sizeof(*o));
1758 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1763 static void o_grow_by(o_string *o, int len)
1765 if (o->length + len > o->maxlen) {
1766 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1767 o->data = xrealloc(o->data, 1 + o->maxlen);
1771 static void o_addchr(o_string *o, int ch)
1773 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1775 o->data[o->length] = ch;
1777 o->data[o->length] = '\0';
1780 static void o_addblock(o_string *o, const char *str, int len)
1783 memcpy(&o->data[o->length], str, len);
1785 o->data[o->length] = '\0';
1789 static void o_addstr(o_string *o, const char *str)
1791 o_addblock(o, str, strlen(str));
1793 static void nommu_addchr(o_string *o, int ch)
1799 # define nommu_addchr(o, str) ((void)0)
1802 static void o_addstr_with_NUL(o_string *o, const char *str)
1804 o_addblock(o, str, strlen(str) + 1);
1807 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1812 && (*str != '*' && *str != '?' && *str != '[')
1820 /* My analysis of quoting semantics tells me that state information
1821 * is associated with a destination, not a source.
1823 static void o_addqchr(o_string *o, int ch)
1826 char *found = strchr("*?[\\", ch);
1831 o->data[o->length] = '\\';
1834 o->data[o->length] = ch;
1836 o->data[o->length] = '\0';
1839 static void o_addQchr(o_string *o, int ch)
1842 if (o->o_escape && strchr("*?[\\", ch)) {
1844 o->data[o->length] = '\\';
1848 o->data[o->length] = ch;
1850 o->data[o->length] = '\0';
1853 static void o_addQstr(o_string *o, const char *str, int len)
1856 o_addblock(o, str, len);
1862 int ordinary_cnt = strcspn(str, "*?[\\");
1863 if (ordinary_cnt > len) /* paranoia */
1865 o_addblock(o, str, ordinary_cnt);
1866 if (ordinary_cnt == len)
1868 str += ordinary_cnt;
1869 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1873 if (ch) { /* it is necessarily one of "*?[\\" */
1875 o->data[o->length] = '\\';
1879 o->data[o->length] = ch;
1881 o->data[o->length] = '\0';
1885 /* A special kind of o_string for $VAR and `cmd` expansion.
1886 * It contains char* list[] at the beginning, which is grown in 16 element
1887 * increments. Actual string data starts at the next multiple of 16 * (char*).
1888 * list[i] contains an INDEX (int!) into this string data.
1889 * It means that if list[] needs to grow, data needs to be moved higher up
1890 * but list[i]'s need not be modified.
1891 * NB: remembering how many list[i]'s you have there is crucial.
1892 * o_finalize_list() operation post-processes this structure - calculates
1893 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1895 #if DEBUG_EXPAND || DEBUG_GLOB
1896 static void debug_print_list(const char *prefix, o_string *o, int n)
1898 char **list = (char**)o->data;
1899 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1903 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1904 prefix, list, n, string_start, o->length, o->maxlen);
1907 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1908 o->data + (int)list[i] + string_start,
1909 o->data + (int)list[i] + string_start);
1913 const char *p = o->data + (int)list[n - 1] + string_start;
1915 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1919 # define debug_print_list(prefix, o, n) ((void)0)
1922 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1923 * in list[n] so that it points past last stored byte so far.
1924 * It returns n+1. */
1925 static int o_save_ptr_helper(o_string *o, int n)
1927 char **list = (char**)o->data;
1931 if (!o->has_empty_slot) {
1932 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1933 string_len = o->length - string_start;
1934 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1935 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1936 /* list[n] points to string_start, make space for 16 more pointers */
1937 o->maxlen += 0x10 * sizeof(list[0]);
1938 o->data = xrealloc(o->data, o->maxlen + 1);
1939 list = (char**)o->data;
1940 memmove(list + n + 0x10, list + n, string_len);
1941 o->length += 0x10 * sizeof(list[0]);
1943 debug_printf_list("list[%d]=%d string_start=%d\n",
1944 n, string_len, string_start);
1947 /* We have empty slot at list[n], reuse without growth */
1948 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1949 string_len = o->length - string_start;
1950 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1951 n, string_len, string_start);
1952 o->has_empty_slot = 0;
1954 list[n] = (char*)(ptrdiff_t)string_len;
1958 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1959 static int o_get_last_ptr(o_string *o, int n)
1961 char **list = (char**)o->data;
1962 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1964 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1967 /* o_glob performs globbing on last list[], saving each result
1968 * as a new list[]. */
1969 static int o_glob(o_string *o, int n)
1975 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1977 return o_save_ptr_helper(o, n);
1978 pattern = o->data + o_get_last_ptr(o, n);
1979 debug_printf_glob("glob pattern '%s'\n", pattern);
1980 if (!glob_needed(pattern)) {
1982 o->length = unbackslash(pattern) - o->data;
1983 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1984 return o_save_ptr_helper(o, n);
1987 memset(&globdata, 0, sizeof(globdata));
1988 gr = glob(pattern, 0, NULL, &globdata);
1989 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1990 if (gr == GLOB_NOSPACE)
1991 bb_error_msg_and_die("out of memory during glob");
1992 if (gr == GLOB_NOMATCH) {
1993 globfree(&globdata);
1996 if (gr != 0) { /* GLOB_ABORTED ? */
1997 /* TODO: testcase for bad glob pattern behavior */
1998 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
2000 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2001 char **argv = globdata.gl_pathv;
2002 o->length = pattern - o->data; /* "forget" pattern */
2004 o_addstr_with_NUL(o, *argv);
2005 n = o_save_ptr_helper(o, n);
2011 globfree(&globdata);
2013 debug_print_list("o_glob returning", o, n);
2017 /* If o->o_glob == 1, glob the string so far remembered.
2018 * Otherwise, just finish current list[] and start new */
2019 static int o_save_ptr(o_string *o, int n)
2021 if (o->o_glob) { /* if globbing is requested */
2022 /* If o->has_empty_slot, list[n] was already globbed
2023 * (if it was requested back then when it was filled)
2024 * so don't do that again! */
2025 if (!o->has_empty_slot)
2026 return o_glob(o, n); /* o_save_ptr_helper is inside */
2028 return o_save_ptr_helper(o, n);
2031 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2032 static char **o_finalize_list(o_string *o, int n)
2037 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2039 debug_print_list("finalized", o, n);
2040 debug_printf_expand("finalized n:%d\n", n);
2041 list = (char**)o->data;
2042 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2046 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
2052 /* Expansion can recurse */
2053 #if ENABLE_HUSH_TICK
2054 static int process_command_subs(o_string *dest, const char *s);
2056 static char *expand_string_to_string(const char *str);
2058 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
2059 parse_stream_dquoted(dest, input, dquote_end)
2061 static int parse_stream_dquoted(o_string *as_string,
2063 struct in_str *input,
2066 /* expand_strvec_to_strvec() takes a list of strings, expands
2067 * all variable references within and returns a pointer to
2068 * a list of expanded strings, possibly with larger number
2069 * of strings. (Think VAR="a b"; echo $VAR).
2070 * This new list is allocated as a single malloc block.
2071 * NULL-terminated list of char* pointers is at the beginning of it,
2072 * followed by strings themself.
2073 * Caller can deallocate entire list by single free(list). */
2075 /* Store given string, finalizing the word and starting new one whenever
2076 * we encounter IFS char(s). This is used for expanding variable values.
2077 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2078 static int expand_on_ifs(o_string *output, int n, const char *str)
2081 int word_len = strcspn(str, G.ifs);
2083 if (output->o_escape || !output->o_glob)
2084 o_addQstr(output, str, word_len);
2085 else /* protect backslashes against globbing up :) */
2086 o_addblock_duplicate_backslash(output, str, word_len);
2089 if (!*str) /* EOL - do not finalize word */
2091 o_addchr(output, '\0');
2092 debug_print_list("expand_on_ifs", output, n);
2093 n = o_save_ptr(output, n);
2094 str += strspn(str, G.ifs); /* skip ifs chars */
2096 debug_print_list("expand_on_ifs[1]", output, n);
2100 /* Helper to expand $((...)) and heredoc body. These act as if
2101 * they are in double quotes, with the exception that they are not :).
2102 * Just the rules are similar: "expand only $var and `cmd`"
2104 * Returns malloced string.
2105 * As an optimization, we return NULL if expansion is not needed.
2107 static char *expand_pseudo_dquoted(const char *str)
2110 struct in_str input;
2111 o_string dest = NULL_O_STRING;
2113 if (strchr(str, '$') == NULL
2114 #if ENABLE_HUSH_TICK
2115 && strchr(str, '`') == NULL
2121 /* We need to expand. Example:
2122 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
2124 setup_string_in_str(&input, str);
2125 parse_stream_dquoted(NULL, &dest, &input, EOF);
2126 //bb_error_msg("'%s' -> '%s'", str, dest.data);
2127 exp_str = expand_string_to_string(dest.data);
2128 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
2129 o_free_unsafe(&dest);
2133 /* Expand all variable references in given string, adding words to list[]
2134 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2135 * to be filled). This routine is extremely tricky: has to deal with
2136 * variables/parameters with whitespace, $* and $@, and constructs like
2137 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2138 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2140 /* or_mask is either 0 (normal case) or 0x80 -
2141 * expansion of right-hand side of assignment == 1-element expand.
2142 * It will also do no globbing, and thus we must not backslash-quote!
2149 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
2150 debug_print_list("expand_vars_to_list", output, n);
2151 n = o_save_ptr(output, n);
2152 debug_print_list("expand_vars_to_list[0]", output, n);
2154 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2157 char *dyn_val = NULL;
2158 const char *val = NULL;
2159 #if ENABLE_HUSH_TICK
2160 o_string subst_result = NULL_O_STRING;
2162 #if ENABLE_SH_MATH_SUPPORT
2163 char arith_buf[sizeof(arith_t)*3 + 2];
2165 o_addblock(output, arg, p - arg);
2166 debug_print_list("expand_vars_to_list[1]", output, n);
2168 p = strchr(p, SPECIAL_VAR_SYMBOL);
2170 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2171 /* "$@" is special. Even if quoted, it can still
2172 * expand to nothing (not even an empty string) */
2173 if ((first_ch & 0x7f) != '@')
2174 ored_ch |= first_ch;
2176 switch (first_ch & 0x7f) {
2177 /* Highest bit in first_ch indicates that var is double-quoted */
2179 val = utoa(G.root_pid);
2181 case '!': /* bg pid */
2182 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2184 case '?': /* exitcode */
2185 val = utoa(G.last_exitcode);
2187 case '#': /* argc */
2188 if (arg[1] != SPECIAL_VAR_SYMBOL)
2189 /* actually, it's a ${#var} */
2191 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2196 if (!G.global_argv[i])
2198 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2199 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2200 smallint sv = output->o_escape;
2201 /* unquoted var's contents should be globbed, so don't escape */
2202 output->o_escape = 0;
2203 while (G.global_argv[i]) {
2204 n = expand_on_ifs(output, n, G.global_argv[i]);
2205 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2206 if (G.global_argv[i++][0] && G.global_argv[i]) {
2207 /* this argv[] is not empty and not last:
2208 * put terminating NUL, start new word */
2209 o_addchr(output, '\0');
2210 debug_print_list("expand_vars_to_list[2]", output, n);
2211 n = o_save_ptr(output, n);
2212 debug_print_list("expand_vars_to_list[3]", output, n);
2215 output->o_escape = sv;
2217 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2218 * and in this case should treat it like '$*' - see 'else...' below */
2219 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2221 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2222 if (++i >= G.global_argc)
2224 o_addchr(output, '\0');
2225 debug_print_list("expand_vars_to_list[4]", output, n);
2226 n = o_save_ptr(output, n);
2228 } else { /* quoted $*: add as one word */
2230 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2231 if (!G.global_argv[++i])
2234 o_addchr(output, G.ifs[0]);
2238 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2239 /* "Empty variable", used to make "" etc to not disappear */
2243 #if ENABLE_HUSH_TICK
2244 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2247 /* Can't just stuff it into output o_string,
2248 * expanded result may need to be globbed
2249 * and $IFS-splitted */
2250 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2251 process_command_subs(&subst_result, arg);
2252 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2253 val = subst_result.data;
2256 #if ENABLE_SH_MATH_SUPPORT
2257 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2258 arith_eval_hooks_t hooks;
2263 arg++; /* skip '+' */
2264 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2265 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2267 exp_str = expand_pseudo_dquoted(arg);
2268 hooks.lookupvar = get_local_var_value;
2269 hooks.setvar = arith_set_local_var;
2270 hooks.endofname = endofname;
2271 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2275 const char *msg = "error in arithmetic";
2278 msg = "exponent less than 0";
2281 msg = "divide by 0";
2284 msg = "expression recursion loop detected";
2289 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2290 sprintf(arith_buf, arith_t_fmt, res);
2295 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2297 bool exp_len = false;
2298 bool exp_null = false;
2300 char exp_save = exp_save; /* for compiler */
2301 char exp_op = exp_op; /* for compiler */
2302 char *exp_word = exp_word; /* for compiler */
2306 arg[0] = first_ch & 0x7f;
2308 /* prepare for expansions */
2309 if (var[0] == '#') {
2310 /* handle length expansion ${#var} */
2314 /* maybe handle parameter expansion */
2315 exp_off = strcspn(var, ":-=+?%#");
2319 exp_save = var[exp_off];
2320 exp_null = exp_save == ':';
2321 exp_word = var + exp_off;
2324 exp_op = *exp_word++;
2325 var[exp_off] = '\0';
2329 /* lookup the variable in question */
2330 if (isdigit(var[0])) {
2331 /* handle_dollar() should have vetted var for us */
2333 if (i < G.global_argc)
2334 val = G.global_argv[i];
2335 /* else val remains NULL: $N with too big N */
2337 val = get_local_var_value(var);
2339 /* handle any expansions */
2341 debug_printf_expand("expand: length of '%s' = ", val);
2342 val = utoa(val ? strlen(val) : 0);
2343 debug_printf_expand("%s\n", val);
2344 } else if (exp_off) {
2345 if (exp_op == '%' || exp_op == '#') {
2347 /* we need to do a pattern match */
2350 scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2351 if (exp_op == *exp_word) /* ## or %% */
2353 val = dyn_val = xstrdup(val);
2354 loc = scan(dyn_val, exp_word, match_at_left);
2355 if (match_at_left) /* # or ## */
2357 else if (loc) /* % or %% and match was found */
2361 /* we need to do an expansion */
2362 int exp_test = (!val || (exp_null && !val[0]));
2364 exp_test = !exp_test;
2365 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2366 exp_null ? "true" : "false", exp_test);
2368 if (exp_op == '?') {
2369 //TODO: how interactive bash aborts expansion mid-command?
2370 /* ${var?[error_msg_if_unset]} */
2371 /* ${var:?[error_msg_if_unset_or_null]} */
2372 /* mimic bash message */
2373 die_if_script("%s: %s",
2375 exp_word[0] ? exp_word : "parameter null or not set"
2381 if (exp_op == '=') {
2382 /* ${var=[word]} or ${var:=[word]} */
2383 if (isdigit(var[0]) || var[0] == '#') {
2384 /* mimic bash message */
2385 die_if_script("$%s: cannot assign in this way", var);
2388 char *new_var = xasprintf("%s=%s", var, val);
2389 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2395 var[exp_off] = exp_save;
2399 #if ENABLE_HUSH_TICK
2402 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2403 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2405 /* unquoted var's contents should be globbed, so don't escape */
2406 smallint sv = output->o_escape;
2407 output->o_escape = 0;
2408 n = expand_on_ifs(output, n, val);
2410 output->o_escape = sv;
2412 } else { /* quoted $VAR, val will be appended below */
2413 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2416 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2419 o_addQstr(output, val, strlen(val));
2422 /* Do the check to avoid writing to a const string */
2423 if (*p != SPECIAL_VAR_SYMBOL)
2424 *p = SPECIAL_VAR_SYMBOL;
2426 #if ENABLE_HUSH_TICK
2427 o_free(&subst_result);
2430 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2433 debug_print_list("expand_vars_to_list[a]", output, n);
2434 /* this part is literal, and it was already pre-quoted
2435 * if needed (much earlier), do not use o_addQstr here! */
2436 o_addstr_with_NUL(output, arg);
2437 debug_print_list("expand_vars_to_list[b]", output, n);
2438 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2439 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2442 /* allow to reuse list[n] later without re-growth */
2443 output->has_empty_slot = 1;
2445 o_addchr(output, '\0');
2450 static char **expand_variables(char **argv, int or_mask)
2455 o_string output = NULL_O_STRING;
2457 if (or_mask & 0x100) {
2458 output.o_escape = 1; /* protect against globbing for "$var" */
2459 /* (unquoted $var will temporarily switch it off) */
2466 n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
2469 debug_print_list("expand_variables", &output, n);
2471 /* output.data (malloced in one block) gets returned in "list" */
2472 list = o_finalize_list(&output, n);
2473 debug_print_strings("expand_variables[1]", list);
2477 static char **expand_strvec_to_strvec(char **argv)
2479 return expand_variables(argv, 0x100);
2482 #if ENABLE_HUSH_BASH_COMPAT
2483 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
2485 return expand_variables(argv, 0x80);
2489 #ifdef CMD_SINGLEWORD_NOGLOB_COND
2490 static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
2495 o_string output = NULL_O_STRING;
2500 int is_var = is_well_formed_var_name(*v, '=');
2501 /* is_var * 0x80: singleword expansion for vars */
2502 n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
2504 /* Subtle! expand_vars_to_list did not glob last word yet.
2505 * It does this only when fed with further data.
2506 * Therefore we set globbing flags AFTER it, not before:
2509 /* if it is not recognizably abc=...; then: */
2510 output.o_escape = !is_var; /* protect against globbing for "$var" */
2511 /* (unquoted $var will temporarily switch it off) */
2512 output.o_glob = !is_var; /* and indeed do globbing */
2515 debug_print_list("expand_cond", &output, n);
2517 /* output.data (malloced in one block) gets returned in "list" */
2518 list = o_finalize_list(&output, n);
2519 debug_print_strings("expand_cond[1]", list);
2524 /* Used for expansion of right hand of assignments */
2525 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2527 static char *expand_string_to_string(const char *str)
2529 char *argv[2], **list;
2531 argv[0] = (char*)str;
2533 list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
2535 if (!list[0] || list[1])
2536 bb_error_msg_and_die("BUG in varexp2");
2537 /* actually, just move string 2*sizeof(char*) bytes back */
2538 overlapping_strcpy((char*)list, list[0]);
2539 unbackslash((char*)list);
2540 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2544 /* Used for "eval" builtin */
2545 static char* expand_strvec_to_string(char **argv)
2549 list = expand_variables(argv, 0x80);
2550 /* Convert all NULs to spaces */
2555 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2556 bb_error_msg_and_die("BUG in varexp3");
2557 /* bash uses ' ' regardless of $IFS contents */
2562 overlapping_strcpy((char*)list, list[0]);
2563 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2567 static char **expand_assignments(char **argv, int count)
2571 /* Expand assignments into one string each */
2572 for (i = 0; i < count; i++) {
2573 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2581 void re_execute_shell(char ***to_free, const char *s,
2582 char *g_argv0, char **g_argv,
2583 char **builtin_argv) NORETURN;
2585 static void reset_traps_to_defaults(void)
2587 /* This function is always called in a child shell
2588 * after fork (not vfork, NOMMU doesn't use this function).
2589 * Child shells are not interactive.
2590 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2591 * Testcase: (while :; do :; done) + ^Z should background.
2592 * Same goes for SIGTERM, SIGHUP, SIGINT.
2597 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2600 /* Stupid. It can be done with *single* &= op, but we can't use
2601 * the fact that G.blocked_set is implemented as a bitmask... */
2602 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2606 sigdelset(&G.blocked_set, sig);
2613 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2614 mask = G.non_DFL_mask;
2615 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2619 G.traps[sig] = NULL;
2620 /* There is no signal for 0 (EXIT) */
2623 /* There was a trap handler, we are removing it.
2624 * But if sig still has non-DFL handling,
2625 * we should not unblock it. */
2628 sigdelset(&G.blocked_set, sig);
2630 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2635 static void re_execute_shell(char ***to_free, const char *s,
2636 char *g_argv0, char **g_argv,
2637 char **builtin_argv) NORETURN;
2638 static void re_execute_shell(char ***to_free, const char *s,
2639 char *g_argv0, char **g_argv,
2640 char **builtin_argv)
2642 char param_buf[sizeof("-$%x:%x:%x:%x:%x") + sizeof(unsigned) * 2];
2643 char *heredoc_argv[4];
2644 struct variable *cur;
2645 #if ENABLE_HUSH_FUNCTIONS
2646 struct function *funcp;
2651 if (!g_argv0) { /* heredoc */
2652 argv = heredoc_argv;
2653 argv[0] = (char *) G.argv0_for_re_execing;
2654 argv[1] = (char *) "-<";
2655 argv[2] = (char *) s;
2657 pp = &argv[3]; /* used as pointer to empty environment */
2663 if (pp) while (*pp++)
2666 sprintf(param_buf, "-$%x:%x:%x:%x" IF_HUSH_LOOPS(":%x")
2667 , (unsigned) G.root_pid
2668 , (unsigned) G.last_bg_pid
2669 , (unsigned) G.last_exitcode
2671 IF_HUSH_LOOPS(, G.depth_of_loop)
2673 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2674 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2677 for (cur = G.top_var; cur; cur = cur->next) {
2678 if (!cur->flg_export || cur->flg_read_only)
2681 #if ENABLE_HUSH_FUNCTIONS
2682 for (funcp = G.top_func; funcp; funcp = funcp->next)
2688 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2689 *pp++ = (char *) G.argv0_for_re_execing;
2691 for (cur = G.top_var; cur; cur = cur->next) {
2692 if (cur->varstr == hush_version_str)
2694 if (cur->flg_read_only) {
2695 *pp++ = (char *) "-R";
2696 *pp++ = cur->varstr;
2697 } else if (!cur->flg_export) {
2698 *pp++ = (char *) "-V";
2699 *pp++ = cur->varstr;
2702 #if ENABLE_HUSH_FUNCTIONS
2703 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2704 *pp++ = (char *) "-F";
2705 *pp++ = funcp->name;
2706 *pp++ = funcp->body_as_string;
2709 /* We can pass activated traps here. Say, -Tnn:trap_string
2711 * However, POSIX says that subshells reset signals with traps
2713 * I tested bash-3.2 and it not only does that with true subshells
2714 * of the form ( list ), but with any forked children shells.
2715 * I set trap "echo W" WINCH; and then tried:
2717 * { echo 1; sleep 20; echo 2; } &
2718 * while true; do echo 1; sleep 20; echo 2; break; done &
2719 * true | { echo 1; sleep 20; echo 2; } | cat
2721 * In all these cases sending SIGWINCH to the child shell
2722 * did not run the trap. If I add trap "echo V" WINCH;
2723 * _inside_ group (just before echo 1), it works.
2725 * I conclude it means we don't need to pass active traps here.
2726 * exec syscall below resets them to SIG_DFL for us.
2728 *pp++ = (char *) "-c";
2731 while (*++builtin_argv)
2732 *pp++ = *builtin_argv;
2733 *pp++ = (char *) "";
2738 /* *pp = NULL; - is already there */
2742 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2743 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2744 execve(bb_busybox_exec_path, argv, pp);
2745 /* Fallback. Useful for init=/bin/hush usage etc */
2746 if (argv[0][0] == '/')
2747 execve(argv[0], argv, pp);
2748 xfunc_error_retval = 127;
2749 bb_error_msg_and_die("can't re-execute the shell");
2751 #endif /* !BB_MMU */
2754 static void setup_heredoc(struct redir_struct *redir)
2756 struct fd_pair pair;
2759 /* the _body_ of heredoc (misleading field name) */
2760 const char *heredoc = redir->rd_filename;
2767 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2768 expanded = expand_pseudo_dquoted(heredoc);
2772 len = strlen(heredoc);
2774 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2776 xmove_fd(pair.rd, redir->rd_fd);
2778 /* Try writing without forking. Newer kernels have
2779 * dynamically growing pipes. Must use non-blocking write! */
2782 written = write(pair.wr, heredoc, len);
2793 ndelay_off(pair.wr);
2795 /* Okay, pipe buffer was not big enough */
2796 /* Note: we must not create a stray child (bastard? :)
2797 * for the unsuspecting parent process. Child creates a grandchild
2798 * and exits before parent execs the process which consumes heredoc
2799 * (that exec happens after we return from this function) */
2805 bb_perror_msg_and_die("vfork");
2808 disable_restore_tty_pgrp_on_exit();
2809 pid = BB_MMU ? fork() : vfork();
2811 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2815 close(redir->rd_fd); /* read side of the pipe */
2817 full_write(pair.wr, heredoc, len); /* may loop or block */
2820 /* Delegate blocking writes to another process */
2821 xmove_fd(pair.wr, STDOUT_FILENO);
2822 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
2826 #if ENABLE_HUSH_FAST
2828 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2830 enable_restore_tty_pgrp_on_exit();
2836 wait(NULL); /* wait till child has died */
2839 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2840 * and stderr if they are redirected. */
2841 static int setup_redirects(struct command *prog, int squirrel[])
2844 struct redir_struct *redir;
2846 for (redir = prog->redirects; redir; redir = redir->next) {
2847 if (redir->rd_type == REDIRECT_HEREDOC2) {
2848 /* rd_fd<<HERE case */
2849 if (squirrel && redir->rd_fd < 3
2850 && squirrel[redir->rd_fd] < 0
2852 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2854 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2856 debug_printf_parse("set heredoc '%s'\n",
2857 redir->rd_filename);
2858 setup_heredoc(redir);
2862 if (redir->rd_dup == REDIRFD_TO_FILE) {
2863 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2865 if (redir->rd_filename == NULL) {
2866 /* Something went wrong in the parse.
2867 * Pretend it didn't happen */
2868 bb_error_msg("bug in redirect parse");
2871 mode = redir_table[redir->rd_type].mode;
2872 p = expand_string_to_string(redir->rd_filename);
2873 openfd = open_or_warn(p, mode);
2876 /* this could get lost if stderr has been redirected, but
2877 * bash and ash both lose it as well (though zsh doesn't!) */
2878 //what the above comment tries to say?
2882 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2883 openfd = redir->rd_dup;
2886 if (openfd != redir->rd_fd) {
2887 if (squirrel && redir->rd_fd < 3
2888 && squirrel[redir->rd_fd] < 0
2890 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2892 if (openfd == REDIRFD_CLOSE) {
2893 /* "n>-" means "close me" */
2894 close(redir->rd_fd);
2896 xdup2(openfd, redir->rd_fd);
2897 if (redir->rd_dup == REDIRFD_TO_FILE)
2905 static void restore_redirects(int squirrel[])
2908 for (i = 0; i < 3; i++) {
2911 /* We simply die on error */
2918 static void free_pipe_list(struct pipe *head);
2920 /* Return code is the exit status of the pipe */
2921 static void free_pipe(struct pipe *pi)
2924 struct command *command;
2925 struct redir_struct *r, *rnext;
2928 if (pi->stopped_cmds > 0) /* why? */
2930 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2931 for (i = 0; i < pi->num_cmds; i++) {
2932 command = &pi->cmds[i];
2933 debug_printf_clean(" command %d:\n", i);
2934 if (command->argv) {
2935 for (a = 0, p = command->argv; *p; a++, p++) {
2936 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2938 free_strings(command->argv);
2939 command->argv = NULL;
2941 /* not "else if": on syntax error, we may have both! */
2942 if (command->group) {
2943 debug_printf_clean(" begin group (cmd_type:%d)\n",
2945 free_pipe_list(command->group);
2946 debug_printf_clean(" end group\n");
2947 command->group = NULL;
2949 /* else is crucial here.
2950 * If group != NULL, child_func is meaningless */
2951 #if ENABLE_HUSH_FUNCTIONS
2952 else if (command->child_func) {
2953 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2954 command->child_func->parent_cmd = NULL;
2958 free(command->group_as_string);
2959 command->group_as_string = NULL;
2961 for (r = command->redirects; r; r = rnext) {
2962 debug_printf_clean(" redirect %d%s",
2963 r->rd_fd, redir_table[r->rd_type].descrip);
2964 /* guard against the case >$FOO, where foo is unset or blank */
2965 if (r->rd_filename) {
2966 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2967 free(r->rd_filename);
2968 r->rd_filename = NULL;
2970 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2974 command->redirects = NULL;
2976 free(pi->cmds); /* children are an array, they get freed all at once */
2984 static void free_pipe_list(struct pipe *head)
2986 struct pipe *pi, *next;
2988 for (pi = head; pi; pi = next) {
2990 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2993 debug_printf_clean("pipe followup code %d\n", pi->followup);
2995 /*pi->next = NULL;*/
3001 static int run_list(struct pipe *pi);
3003 #define parse_stream(pstring, input, end_trigger) \
3004 parse_stream(input, end_trigger)
3006 static struct pipe *parse_stream(char **pstring,
3007 struct in_str *input,
3009 static void parse_and_run_string(const char *s);
3012 static char *find_in_path(const char *arg)
3015 const char *PATH = get_local_var_value("PATH");
3021 const char *end = strchrnul(PATH, ':');
3022 int sz = end - PATH; /* must be int! */
3026 ret = xasprintf("%.*s/%s", sz, PATH, arg);
3028 /* We have xxx::yyyy in $PATH,
3029 * it means "use current dir" */
3032 if (access(ret, F_OK) == 0)
3045 static const struct built_in_command* find_builtin_helper(const char *name,
3046 const struct built_in_command *x,
3047 const struct built_in_command *end)
3050 if (strcmp(name, x->cmd) != 0) {
3054 debug_printf_exec("found builtin '%s'\n", name);
3059 static const struct built_in_command* find_builtin1(const char *name)
3061 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
3063 static const struct built_in_command* find_builtin(const char *name)
3065 const struct built_in_command *x = find_builtin1(name);
3068 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
3071 #if ENABLE_HUSH_FUNCTIONS
3072 static const struct function *find_function(const char *name)
3074 const struct function *funcp = G.top_func;
3076 if (strcmp(name, funcp->name) == 0) {
3079 funcp = funcp->next;
3082 debug_printf_exec("found function '%s'\n", name);
3086 /* Note: takes ownership on name ptr */
3087 static struct function *new_function(char *name)
3089 struct function *funcp;
3090 struct function **funcpp = &G.top_func;
3092 while ((funcp = *funcpp) != NULL) {
3093 struct command *cmd;
3095 if (strcmp(funcp->name, name) != 0) {
3096 funcpp = &funcp->next;
3100 cmd = funcp->parent_cmd;
3101 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
3103 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
3105 /* Note: if !funcp->body, do not free body_as_string!
3106 * This is a special case of "-F name body" function:
3107 * body_as_string was not malloced! */
3109 free_pipe_list(funcp->body);
3111 free(funcp->body_as_string);
3115 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
3116 cmd->argv[0] = funcp->name;
3117 cmd->group = funcp->body;
3119 cmd->group_as_string = funcp->body_as_string;
3124 debug_printf_exec("remembering new function '%s'\n", name);
3125 funcp = *funcpp = xzalloc(sizeof(*funcp));
3126 /*funcp->next = NULL;*/
3132 static void unset_func(const char *name)
3134 struct function *funcp;
3135 struct function **funcpp = &G.top_func;
3137 while ((funcp = *funcpp) != NULL) {
3138 if (strcmp(funcp->name, name) == 0) {
3139 *funcpp = funcp->next;
3140 /* funcp is unlinked now, deleting it.
3141 * Note: if !funcp->body, the function was created by
3142 * "-F name body", do not free ->body_as_string
3143 * and ->name as they were not malloced. */
3145 free_pipe_list(funcp->body);
3148 free(funcp->body_as_string);
3154 funcpp = &funcp->next;
3159 #define exec_function(to_free, funcp, argv) \
3160 exec_function(funcp, argv)
3162 static void exec_function(char ***to_free,
3163 const struct function *funcp,
3164 char **argv) NORETURN;
3165 static void exec_function(char ***to_free,
3166 const struct function *funcp,
3172 argv[0] = G.global_argv[0];
3173 G.global_argv = argv;
3177 /* On MMU, funcp->body is always non-NULL */
3178 n = run_list(funcp->body);
3182 re_execute_shell(to_free,
3183 funcp->body_as_string,
3190 static int run_function(const struct function *funcp, char **argv)
3196 save_and_replace_G_args(&sv, argv);
3198 /* "we are in function, ok to use return" */
3199 sv_flg = G.flag_return_in_progress;
3200 G.flag_return_in_progress = -1;
3201 #if ENABLE_HUSH_LOCAL
3202 G.func_nest_level++;
3205 /* On MMU, funcp->body is always non-NULL */
3208 /* Function defined by -F */
3209 parse_and_run_string(funcp->body_as_string);
3210 rc = G.last_exitcode;
3214 rc = run_list(funcp->body);
3217 #if ENABLE_HUSH_LOCAL
3219 struct variable *var;
3220 struct variable **var_pp;
3222 var_pp = &G.top_var;
3223 while ((var = *var_pp) != NULL) {
3224 if (var->func_nest_level < G.func_nest_level) {
3225 var_pp = &var->next;
3229 if (var->flg_export)
3230 bb_unsetenv(var->varstr);
3231 /* Remove from global list */
3232 *var_pp = var->next;
3238 G.func_nest_level--;
3241 G.flag_return_in_progress = sv_flg;
3243 restore_G_args(&sv, argv);
3247 #endif /* ENABLE_HUSH_FUNCTIONS */
3251 #define exec_builtin(to_free, x, argv) \
3252 exec_builtin(x, argv)
3254 #define exec_builtin(to_free, x, argv) \
3255 exec_builtin(to_free, argv)
3257 static void exec_builtin(char ***to_free,
3258 const struct built_in_command *x,
3259 char **argv) NORETURN;
3260 static void exec_builtin(char ***to_free,
3261 const struct built_in_command *x,
3265 int rcode = x->function(argv);
3269 /* On NOMMU, we must never block!
3270 * Example: { sleep 99 | read line; } & echo Ok
3272 re_execute_shell(to_free,
3282 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
3283 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
3284 #define pseudo_exec(nommu_save, command, argv_expanded) \
3285 pseudo_exec(command, argv_expanded)
3288 /* Called after [v]fork() in run_pipe, or from builtin_exec.
3290 * Don't exit() here. If you don't exec, use _exit instead.
3291 * The at_exit handlers apparently confuse the calling process,
3292 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
3293 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3294 char **argv, int assignment_cnt,
3295 char **argv_expanded) NORETURN;
3296 static void pseudo_exec_argv(nommu_save_t *nommu_save,
3297 char **argv, int assignment_cnt,
3298 char **argv_expanded)
3302 /* Case when we are here: ... | var=val | ... */
3303 if (!argv[assignment_cnt])
3304 _exit(EXIT_SUCCESS);
3306 new_env = expand_assignments(argv, assignment_cnt);
3308 set_vars_and_save_old(new_env);
3309 free(new_env); /* optional */
3310 /* we can also destroy set_vars_and_save_old's return value,
3313 nommu_save->new_env = new_env;
3314 nommu_save->old_vars = set_vars_and_save_old(new_env);
3316 if (argv_expanded) {
3317 argv = argv_expanded;
3319 argv = expand_strvec_to_strvec(argv + assignment_cnt);
3321 nommu_save->argv = argv;
3325 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3326 if (strchr(argv[0], '/') != NULL)
3330 /* Check if the command matches any of the builtins.
3331 * Depending on context, this might be redundant. But it's
3332 * easier to waste a few CPU cycles than it is to figure out
3333 * if this is one of those cases.
3336 /* On NOMMU, it is more expensive to re-execute shell
3337 * just in order to run echo or test builtin.
3338 * It's better to skip it here and run corresponding
3339 * non-builtin later. */
3340 const struct built_in_command *x;
3341 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
3343 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
3346 #if ENABLE_HUSH_FUNCTIONS
3347 /* Check if the command matches any functions */
3349 const struct function *funcp = find_function(argv[0]);
3351 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
3356 #if ENABLE_FEATURE_SH_STANDALONE
3357 /* Check if the command matches any busybox applets */
3359 int a = find_applet_by_name(argv[0]);
3361 # if BB_MMU /* see above why on NOMMU it is not allowed */
3362 if (APPLET_IS_NOEXEC(a)) {
3363 debug_printf_exec("running applet '%s'\n", argv[0]);
3364 run_applet_no_and_exit(a, argv);
3367 /* Re-exec ourselves */
3368 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3369 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3370 execv(bb_busybox_exec_path, argv);
3371 /* If they called chroot or otherwise made the binary no longer
3372 * executable, fall through */
3377 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3380 debug_printf_exec("execing '%s'\n", argv[0]);
3381 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3382 execvp(argv[0], argv);
3383 bb_perror_msg("can't execute '%s'", argv[0]);
3384 _exit(EXIT_FAILURE);
3387 /* Called after [v]fork() in run_pipe
3389 static void pseudo_exec(nommu_save_t *nommu_save,
3390 struct command *command,
3391 char **argv_expanded) NORETURN;
3392 static void pseudo_exec(nommu_save_t *nommu_save,
3393 struct command *command,
3394 char **argv_expanded)
3396 if (command->argv) {
3397 pseudo_exec_argv(nommu_save, command->argv,
3398 command->assignment_cnt, argv_expanded);
3401 if (command->group) {
3402 /* Cases when we are here:
3405 * ... | ( list ) | ...
3406 * ... | { list } | ...
3410 debug_printf_exec("pseudo_exec: run_list\n");
3411 reset_traps_to_defaults();
3412 rcode = run_list(command->group);
3413 /* OK to leak memory by not calling free_pipe_list,
3414 * since this process is about to exit */
3417 re_execute_shell(&nommu_save->argv_from_re_execing,
3418 command->group_as_string,
3425 /* Case when we are here: ... | >file */
3426 debug_printf_exec("pseudo_exec'ed null command\n");
3427 _exit(EXIT_SUCCESS);
3431 static const char *get_cmdtext(struct pipe *pi)
3437 /* This is subtle. ->cmdtext is created only on first backgrounding.
3438 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3439 * On subsequent bg argv is trashed, but we won't use it */
3442 argv = pi->cmds[0].argv;
3443 if (!argv || !argv[0]) {
3444 pi->cmdtext = xzalloc(1);
3450 len += strlen(*argv) + 1;
3454 argv = pi->cmds[0].argv;
3456 len = strlen(*argv);
3457 memcpy(p, *argv, len);
3465 static void insert_bg_job(struct pipe *pi)
3467 struct pipe *job, **jobp;
3470 /* Linear search for the ID of the job to use */
3472 for (job = G.job_list; job; job = job->next)
3473 if (job->jobid >= pi->jobid)
3474 pi->jobid = job->jobid + 1;
3476 /* Add job to the list of running jobs */
3478 while ((job = *jobp) != NULL)
3480 job = *jobp = xmalloc(sizeof(*job));
3482 *job = *pi; /* physical copy */
3484 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3485 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3486 for (i = 0; i < pi->num_cmds; i++) {
3487 job->cmds[i].pid = pi->cmds[i].pid;
3488 /* all other fields are not used and stay zero */
3490 job->cmdtext = xstrdup(get_cmdtext(pi));
3492 if (G_interactive_fd)
3493 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3494 /* Last command's pid goes to $! */
3495 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3496 G.last_jobid = job->jobid;
3499 static void remove_bg_job(struct pipe *pi)
3501 struct pipe *prev_pipe;
3503 if (pi == G.job_list) {
3504 G.job_list = pi->next;
3506 prev_pipe = G.job_list;
3507 while (prev_pipe->next != pi)
3508 prev_pipe = prev_pipe->next;
3509 prev_pipe->next = pi->next;
3512 G.last_jobid = G.job_list->jobid;
3517 /* Remove a backgrounded job */
3518 static void delete_finished_bg_job(struct pipe *pi)
3521 pi->stopped_cmds = 0;
3527 /* Check to see if any processes have exited -- if they
3528 * have, figure out why and see if a job has completed */
3529 static int checkjobs(struct pipe* fg_pipe)
3539 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3541 attributes = WUNTRACED;
3542 if (fg_pipe == NULL)
3543 attributes |= WNOHANG;
3546 #if ENABLE_HUSH_FAST
3547 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
3548 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
3549 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
3550 /* There was neither fork nor SIGCHLD since last waitpid */
3551 /* Avoid doing waitpid syscall if possible */
3552 if (!G.we_have_children) {
3556 if (fg_pipe == NULL) { /* is WNOHANG set? */
3557 /* We have children, but they did not exit
3558 * or stop yet (we saw no SIGCHLD) */
3561 /* else: !WNOHANG, waitpid will block, can't short-circuit */
3565 /* Do we do this right?
3566 * bash-3.00# sleep 20 | false
3568 * [3]+ Stopped sleep 20 | false
3569 * bash-3.00# echo $?
3570 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3571 * [hush 1.14.0: yes we do it right]
3578 #if ENABLE_HUSH_FAST
3579 i = G.count_SIGCHLD;
3581 childpid = waitpid(-1, &status, attributes);
3582 if (childpid <= 0) {
3583 if (childpid && errno != ECHILD)
3584 bb_perror_msg("waitpid");
3585 #if ENABLE_HUSH_FAST
3586 else { /* Until next SIGCHLD, waitpid's are useless */
3587 G.we_have_children = (childpid == 0);
3588 G.handled_SIGCHLD = i;
3589 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
3594 dead = WIFEXITED(status) || WIFSIGNALED(status);
3597 if (WIFSTOPPED(status))
3598 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3599 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3600 if (WIFSIGNALED(status))
3601 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3602 childpid, WTERMSIG(status), WEXITSTATUS(status));
3603 if (WIFEXITED(status))
3604 debug_printf_jobs("pid %d exited, exitcode %d\n",
3605 childpid, WEXITSTATUS(status));
3607 /* Were we asked to wait for fg pipe? */
3609 for (i = 0; i < fg_pipe->num_cmds; i++) {
3610 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3611 if (fg_pipe->cmds[i].pid != childpid)
3614 fg_pipe->cmds[i].pid = 0;
3615 fg_pipe->alive_cmds--;
3616 if (i == fg_pipe->num_cmds - 1) {
3617 /* last process gives overall exitstatus */
3618 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3619 rcode = WEXITSTATUS(status);
3620 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3621 /* bash prints killing signal's name for *last*
3622 * process in pipe (prints just newline for SIGINT).
3623 * Mimic this. Example: "sleep 5" + ^\
3625 if (WIFSIGNALED(status)) {
3626 int sig = WTERMSIG(status);
3627 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3631 fg_pipe->cmds[i].is_stopped = 1;
3632 fg_pipe->stopped_cmds++;
3634 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3635 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3636 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3637 /* All processes in fg pipe have exited or stopped */
3638 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3639 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3640 * and "killall -STOP cat" */
3641 if (G_interactive_fd) {
3643 if (fg_pipe->alive_cmds)
3644 insert_bg_job(fg_pipe);
3648 if (!fg_pipe->alive_cmds)
3651 /* There are still running processes in the fg pipe */
3652 goto wait_more; /* do waitpid again */
3654 /* it wasnt fg_pipe, look for process in bg pipes */
3658 /* We asked to wait for bg or orphaned children */
3659 /* No need to remember exitcode in this case */
3660 for (pi = G.job_list; pi; pi = pi->next) {
3661 for (i = 0; i < pi->num_cmds; i++) {
3662 if (pi->cmds[i].pid == childpid)
3663 goto found_pi_and_prognum;
3666 /* Happens when shell is used as init process (init=/bin/sh) */
3667 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3668 continue; /* do waitpid again */
3670 found_pi_and_prognum:
3673 pi->cmds[i].pid = 0;
3675 if (!pi->alive_cmds) {
3676 if (G_interactive_fd)
3677 printf(JOB_STATUS_FORMAT, pi->jobid,
3678 "Done", pi->cmdtext);
3679 delete_finished_bg_job(pi);
3683 pi->cmds[i].is_stopped = 1;
3687 } /* while (waitpid succeeds)... */
3693 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3696 int rcode = checkjobs(fg_pipe);
3697 if (G_saved_tty_pgrp) {
3698 /* Job finished, move the shell to the foreground */
3699 p = getpgrp(); /* our process group id */
3700 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
3701 tcsetpgrp(G_interactive_fd, p);
3707 /* Start all the jobs, but don't wait for anything to finish.
3710 * Return code is normally -1, when the caller has to wait for children
3711 * to finish to determine the exit status of the pipe. If the pipe
3712 * is a simple builtin command, however, the action is done by the
3713 * time run_pipe returns, and the exit code is provided as the
3716 * Returns -1 only if started some children. IOW: we have to
3717 * mask out retvals of builtins etc with 0xff!
3719 * The only case when we do not need to [v]fork is when the pipe
3720 * is single, non-backgrounded, non-subshell command. Examples:
3721 * cmd ; ... { list } ; ...
3722 * cmd && ... { list } && ...
3723 * cmd || ... { list } || ...
3724 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3725 * or (if SH_STANDALONE) an applet, and we can run the { list }
3726 * with run_list. If it isn't one of these, we fork and exec cmd.
3728 * Cases when we must fork:
3729 * non-single: cmd | cmd
3730 * backgrounded: cmd & { list } &
3731 * subshell: ( list ) [&]
3733 static int run_pipe(struct pipe *pi)
3735 static const char *const null_ptr = NULL;
3738 struct command *command;
3739 char **argv_expanded;
3742 /* it is not always needed, but we aim to smaller code */
3743 int squirrel[] = { -1, -1, -1 };
3746 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3749 IF_HUSH_JOB(pi->pgrp = -1;)
3750 pi->stopped_cmds = 0;
3751 command = &(pi->cmds[0]);
3752 argv_expanded = NULL;
3754 if (pi->num_cmds != 1
3755 || pi->followup == PIPE_BG
3756 || command->cmd_type == CMD_SUBSHELL
3763 debug_printf_exec(": group:%p argv:'%s'\n",
3764 command->group, command->argv ? command->argv[0] : "NONE");
3766 if (command->group) {
3767 #if ENABLE_HUSH_FUNCTIONS
3768 if (command->cmd_type == CMD_FUNCDEF) {
3769 /* "executing" func () { list } */
3770 struct function *funcp;
3772 funcp = new_function(command->argv[0]);
3773 /* funcp->name is already set to argv[0] */
3774 funcp->body = command->group;
3776 funcp->body_as_string = command->group_as_string;
3777 command->group_as_string = NULL;
3779 command->group = NULL;
3780 command->argv[0] = NULL;
3781 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3782 funcp->parent_cmd = command;
3783 command->child_func = funcp;
3785 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3787 return EXIT_SUCCESS;
3791 debug_printf("non-subshell group\n");
3792 rcode = 1; /* exitcode if redir failed */
3793 if (setup_redirects(command, squirrel) == 0) {
3794 debug_printf_exec(": run_list\n");
3795 rcode = run_list(command->group) & 0xff;
3797 restore_redirects(squirrel);
3798 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3800 debug_printf_exec("run_pipe: return %d\n", rcode);
3804 argv = command->argv ? command->argv : (char **) &null_ptr;
3806 const struct built_in_command *x;
3807 #if ENABLE_HUSH_FUNCTIONS
3808 const struct function *funcp;
3812 char **new_env = NULL;
3813 struct variable *old_vars = NULL;
3815 if (argv[command->assignment_cnt] == NULL) {
3816 /* Assignments, but no command */
3817 /* Ensure redirects take effect. Try "a=t >file" */
3818 rcode = setup_redirects(command, squirrel);
3819 restore_redirects(squirrel);
3820 /* Set shell variables */
3822 p = expand_string_to_string(*argv);
3823 debug_printf_exec("set shell var:'%s'->'%s'\n",
3825 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
3828 /* Do we need to flag set_local_var() errors?
3829 * "assignment to readonly var" and "putenv error"
3831 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3833 debug_printf_exec("run_pipe: return %d\n", rcode);
3837 /* Expand the rest into (possibly) many strings each */
3839 #if ENABLE_HUSH_BASH_COMPAT
3840 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
3841 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
3844 #ifdef CMD_SINGLEWORD_NOGLOB_COND
3845 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
3846 argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
3851 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3854 x = find_builtin(argv_expanded[0]);
3855 #if ENABLE_HUSH_FUNCTIONS
3858 funcp = find_function(argv_expanded[0]);
3862 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3863 debug_printf("exec with redirects only\n");
3864 rcode = setup_redirects(command, NULL);
3865 goto clean_up_and_ret1;
3868 /* setup_redirects acts on file descriptors, not FILEs.
3869 * This is perfect for work that comes after exec().
3870 * Is it really safe for inline use? Experimentally,
3871 * things seem to work. */
3872 rcode = setup_redirects(command, squirrel);
3874 new_env = expand_assignments(argv, command->assignment_cnt);
3875 old_vars = set_vars_and_save_old(new_env);
3877 debug_printf_exec(": builtin '%s' '%s'...\n",
3878 x->cmd, argv_expanded[1]);
3879 rcode = x->function(argv_expanded) & 0xff;
3882 #if ENABLE_HUSH_FUNCTIONS
3884 # if ENABLE_HUSH_LOCAL
3885 struct variable **sv;
3886 sv = G.shadowed_vars_pp;
3887 G.shadowed_vars_pp = &old_vars;
3889 debug_printf_exec(": function '%s' '%s'...\n",
3890 funcp->name, argv_expanded[1]);
3891 rcode = run_function(funcp, argv_expanded) & 0xff;
3892 # if ENABLE_HUSH_LOCAL
3893 G.shadowed_vars_pp = sv;
3898 #if ENABLE_FEATURE_SH_STANDALONE
3901 restore_redirects(squirrel);
3902 unset_vars(new_env);
3905 free(argv_expanded);
3906 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3908 debug_printf_exec("run_pipe return %d\n", rcode);
3912 #if ENABLE_FEATURE_SH_STANDALONE
3913 i = find_applet_by_name(argv_expanded[0]);
3914 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3915 rcode = setup_redirects(command, squirrel);
3917 new_env = expand_assignments(argv, command->assignment_cnt);
3918 old_vars = set_vars_and_save_old(new_env);
3919 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3920 argv_expanded[0], argv_expanded[1]);
3921 rcode = run_nofork_applet(i, argv_expanded);
3923 goto clean_up_and_ret;
3926 /* It is neither builtin nor applet. We must fork. */
3930 /* NB: argv_expanded may already be created, and that
3931 * might include `cmd` runs! Do not rerun it! We *must*
3932 * use argv_expanded if it's non-NULL */
3934 /* Going to fork a child per each pipe member */
3938 for (i = 0; i < pi->num_cmds; i++) {
3939 struct fd_pair pipefds;
3941 volatile nommu_save_t nommu_save;
3942 nommu_save.new_env = NULL;
3943 nommu_save.old_vars = NULL;
3944 nommu_save.argv = NULL;
3945 nommu_save.argv_from_re_execing = NULL;
3947 command = &(pi->cmds[i]);
3948 if (command->argv) {
3949 debug_printf_exec(": pipe member '%s' '%s'...\n",
3950 command->argv[0], command->argv[1]);
3952 debug_printf_exec(": pipe member with no argv\n");
3955 /* pipes are inserted between pairs of commands */
3958 if ((i + 1) < pi->num_cmds)
3959 xpiped_pair(pipefds);
3961 command->pid = BB_MMU ? fork() : vfork();
3962 if (!command->pid) { /* child */
3964 disable_restore_tty_pgrp_on_exit();
3966 /* Every child adds itself to new process group
3967 * with pgid == pid_of_first_child_in_pipe */
3968 if (G.run_list_level == 1 && G_interactive_fd) {
3971 if (pgrp < 0) /* true for 1st process only */
3973 if (setpgid(0, pgrp) == 0
3974 && pi->followup != PIPE_BG
3975 && G_saved_tty_pgrp /* we have ctty */
3977 /* We do it in *every* child, not just first,
3979 tcsetpgrp(G_interactive_fd, pgrp);
3983 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
3984 /* 1st cmd in backgrounded pipe
3985 * should have its stdin /dev/null'ed */
3987 if (open(bb_dev_null, O_RDONLY))
3988 xopen("/", O_RDONLY);
3990 xmove_fd(nextin, 0);
3992 xmove_fd(pipefds.wr, 1);
3995 /* Like bash, explicit redirects override pipes,
3996 * and the pipe fd is available for dup'ing. */
3997 if (setup_redirects(command, NULL))
4000 /* Restore default handlers just prior to exec */
4001 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
4003 /* Stores to nommu_save list of env vars putenv'ed
4004 * (NOMMU, on MMU we don't need that) */
4005 /* cast away volatility... */
4006 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
4007 /* pseudo_exec() does not return */
4010 /* parent or error */
4011 #if ENABLE_HUSH_FAST
4013 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
4015 enable_restore_tty_pgrp_on_exit();
4017 /* Clean up after vforked child */
4018 free(nommu_save.argv);
4019 free(nommu_save.argv_from_re_execing);
4020 unset_vars(nommu_save.new_env);
4021 add_vars(nommu_save.old_vars);
4023 free(argv_expanded);
4024 argv_expanded = NULL;
4025 if (command->pid < 0) { /* [v]fork failed */
4026 /* Clearly indicate, was it fork or vfork */
4027 bb_perror_msg(BB_MMU ? "fork" : "vfork");
4031 /* Second and next children need to know pid of first one */
4033 pi->pgrp = command->pid;
4039 if ((i + 1) < pi->num_cmds)
4041 /* Pass read (output) pipe end to next iteration */
4042 nextin = pipefds.rd;
4045 if (!pi->alive_cmds) {
4047 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
4052 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
4056 #ifndef debug_print_tree
4057 static void debug_print_tree(struct pipe *pi, int lvl)
4059 static const char *const PIPE[] = {
4065 static const char *RES[] = {
4066 [RES_NONE ] = "NONE" ,
4069 [RES_THEN ] = "THEN" ,
4070 [RES_ELIF ] = "ELIF" ,
4071 [RES_ELSE ] = "ELSE" ,
4074 #if ENABLE_HUSH_LOOPS
4075 [RES_FOR ] = "FOR" ,
4076 [RES_WHILE] = "WHILE",
4077 [RES_UNTIL] = "UNTIL",
4079 [RES_DONE ] = "DONE" ,
4081 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
4084 #if ENABLE_HUSH_CASE
4085 [RES_CASE ] = "CASE" ,
4086 [RES_CASE_IN ] = "CASE_IN" ,
4087 [RES_MATCH] = "MATCH",
4088 [RES_CASE_BODY] = "CASE_BODY",
4089 [RES_ESAC ] = "ESAC" ,
4091 [RES_XXXX ] = "XXXX" ,
4092 [RES_SNTX ] = "SNTX" ,
4094 static const char *const CMDTYPE[] = {
4098 #if ENABLE_HUSH_FUNCTIONS
4107 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
4108 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
4110 while (prn < pi->num_cmds) {
4111 struct command *command = &pi->cmds[prn];
4112 char **argv = command->argv;
4114 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
4116 command->assignment_cnt);
4117 if (command->group) {
4118 fprintf(stderr, " group %s: (argv=%p)\n",
4119 CMDTYPE[command->cmd_type],
4121 debug_print_tree(command->group, lvl+1);
4125 if (argv) while (*argv) {
4126 fprintf(stderr, " '%s'", *argv);
4129 fprintf(stderr, "\n");
4138 /* NB: called by pseudo_exec, and therefore must not modify any
4139 * global data until exec/_exit (we can be a child after vfork!) */
4140 static int run_list(struct pipe *pi)
4142 #if ENABLE_HUSH_CASE
4143 char *case_word = NULL;
4145 #if ENABLE_HUSH_LOOPS
4146 struct pipe *loop_top = NULL;
4147 char **for_lcur = NULL;
4148 char **for_list = NULL;
4150 smallint last_followup;
4152 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
4153 smalluint cond_code = 0;
4155 enum { cond_code = 0 };
4158 smallint rword; /* enum reserved_style */
4159 smallint last_rword; /* ditto */
4162 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
4165 #if ENABLE_HUSH_LOOPS
4166 /* Check syntax for "for" */
4167 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
4168 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
4170 /* current word is FOR or IN (BOLD in comments below) */
4171 if (cpipe->next == NULL) {
4172 syntax_error("malformed for");
4174 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4177 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
4178 if (cpipe->next->res_word == RES_DO)
4180 /* next word is not "do". It must be "in" then ("FOR v in ...") */
4181 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
4182 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
4184 syntax_error("malformed for");
4186 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
4192 /* Past this point, all code paths should jump to ret: label
4193 * in order to return, no direct "return" statements please.
4194 * This helps to ensure that no memory is leaked. */
4202 last_rword = RES_XXXX;
4204 last_followup = PIPE_SEQ;
4205 rcode = G.last_exitcode;
4207 /* Go through list of pipes, (maybe) executing them. */
4208 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
4212 IF_HAS_KEYWORDS(rword = pi->res_word;)
4213 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
4214 rword, cond_code, last_rword);
4215 #if ENABLE_HUSH_LOOPS
4216 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
4217 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
4219 /* start of a loop: remember where loop starts */
4224 /* Still in the same "if...", "then..." or "do..." branch? */
4225 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
4226 if ((rcode == 0 && last_followup == PIPE_OR)
4227 || (rcode != 0 && last_followup == PIPE_AND)
4229 /* It is "<true> || CMD" or "<false> && CMD"
4230 * and we should not execute CMD */
4231 debug_printf_exec("skipped cmd because of || or &&\n");
4232 last_followup = pi->followup;
4236 last_followup = pi->followup;
4237 IF_HAS_KEYWORDS(last_rword = rword;)
4240 if (rword == RES_THEN) {
4241 /* if false; then ... fi has exitcode 0! */
4242 G.last_exitcode = rcode = EXIT_SUCCESS;
4243 /* "if <false> THEN cmd": skip cmd */
4247 if (rword == RES_ELSE || rword == RES_ELIF) {
4248 /* "if <true> then ... ELSE/ELIF cmd":
4249 * skip cmd and all following ones */
4254 #if ENABLE_HUSH_LOOPS
4255 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
4257 /* first loop through for */
4259 static const char encoded_dollar_at[] ALIGN1 = {
4260 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
4261 }; /* encoded representation of "$@" */
4262 static const char *const encoded_dollar_at_argv[] = {
4263 encoded_dollar_at, NULL
4264 }; /* argv list with one element: "$@" */
4267 vals = (char**)encoded_dollar_at_argv;
4268 if (pi->next->res_word == RES_IN) {
4269 /* if no variable values after "in" we skip "for" */
4270 if (!pi->next->cmds[0].argv) {
4271 G.last_exitcode = rcode = EXIT_SUCCESS;
4272 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
4275 vals = pi->next->cmds[0].argv;
4276 } /* else: "for var; do..." -> assume "$@" list */
4277 /* create list of variable values */
4278 debug_print_strings("for_list made from", vals);
4279 for_list = expand_strvec_to_strvec(vals);
4280 for_lcur = for_list;
4281 debug_print_strings("for_list", for_list);
4284 /* "for" loop is over, clean up */
4290 /* Insert next value from for_lcur */
4291 /* note: *for_lcur already has quotes removed, $var expanded, etc */
4292 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4295 if (rword == RES_IN) {
4296 continue; /* "for v IN list;..." - "in" has no cmds anyway */
4298 if (rword == RES_DONE) {
4299 continue; /* "done" has no cmds too */
4302 #if ENABLE_HUSH_CASE
4303 if (rword == RES_CASE) {
4304 case_word = expand_strvec_to_string(pi->cmds->argv);
4307 if (rword == RES_MATCH) {
4310 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
4312 /* all prev words didn't match, does this one match? */
4313 argv = pi->cmds->argv;
4315 char *pattern = expand_string_to_string(*argv);
4316 /* TODO: which FNM_xxx flags to use? */
4317 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
4319 if (cond_code == 0) { /* match! we will execute this branch */
4320 free(case_word); /* make future "word)" stop */
4328 if (rword == RES_CASE_BODY) { /* inside of a case branch */
4330 continue; /* not matched yet, skip this pipe */
4333 /* Just pressing <enter> in shell should check for jobs.
4334 * OTOH, in non-interactive shell this is useless
4335 * and only leads to extra job checks */
4336 if (pi->num_cmds == 0) {
4337 if (G_interactive_fd)
4338 goto check_jobs_and_continue;
4342 /* After analyzing all keywords and conditions, we decided
4343 * to execute this pipe. NB: have to do checkjobs(NULL)
4344 * after run_pipe to collect any background children,
4345 * even if list execution is to be stopped. */
4346 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
4349 #if ENABLE_HUSH_LOOPS
4350 G.flag_break_continue = 0;
4352 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
4354 /* We ran a builtin, function, or group.
4355 * rcode is already known
4356 * and we don't need to wait for anything. */
4357 G.last_exitcode = rcode;
4358 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
4359 check_and_run_traps(0);
4360 #if ENABLE_HUSH_LOOPS
4361 /* Was it "break" or "continue"? */
4362 if (G.flag_break_continue) {
4363 smallint fbc = G.flag_break_continue;
4364 /* We might fall into outer *loop*,
4365 * don't want to break it too */
4367 G.depth_break_continue--;
4368 if (G.depth_break_continue == 0)
4369 G.flag_break_continue = 0;
4370 /* else: e.g. "continue 2" should *break* once, *then* continue */
4371 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
4372 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
4373 goto check_jobs_and_break;
4374 /* "continue": simulate end of loop */
4379 #if ENABLE_HUSH_FUNCTIONS
4380 if (G.flag_return_in_progress == 1) {
4381 /* same as "goto check_jobs_and_break" */
4386 } else if (pi->followup == PIPE_BG) {
4387 /* What does bash do with attempts to background builtins? */
4388 /* even bash 3.2 doesn't do that well with nested bg:
4389 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
4390 * I'm NOT treating inner &'s as jobs */
4391 check_and_run_traps(0);
4393 if (G.run_list_level == 1)
4396 G.last_exitcode = rcode = EXIT_SUCCESS;
4397 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4400 if (G.run_list_level == 1 && G_interactive_fd) {
4401 /* Waits for completion, then fg's main shell */
4402 rcode = checkjobs_and_fg_shell(pi);
4403 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4404 check_and_run_traps(0);
4407 { /* This one just waits for completion */
4408 rcode = checkjobs(pi);
4409 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4410 check_and_run_traps(0);
4412 G.last_exitcode = rcode;
4416 /* Analyze how result affects subsequent commands */
4418 if (rword == RES_IF || rword == RES_ELIF)
4421 #if ENABLE_HUSH_LOOPS
4422 /* Beware of "while false; true; do ..."! */
4423 if (pi->next && pi->next->res_word == RES_DO) {
4424 if (rword == RES_WHILE) {
4426 /* "while false; do...done" - exitcode 0 */
4427 G.last_exitcode = rcode = EXIT_SUCCESS;
4428 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4429 goto check_jobs_and_break;
4432 if (rword == RES_UNTIL) {
4434 debug_printf_exec(": until expr is true: breaking\n");
4435 check_jobs_and_break:
4443 check_jobs_and_continue:
4450 #if ENABLE_HUSH_LOOPS
4455 #if ENABLE_HUSH_CASE
4459 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4463 /* Select which version we will use */
4464 static int run_and_free_list(struct pipe *pi)
4467 debug_printf_exec("run_and_free_list entered\n");
4469 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4470 rcode = run_list(pi);
4472 /* free_pipe_list has the side effect of clearing memory.
4473 * In the long run that function can be merged with run_list,
4474 * but doing that now would hobble the debugging effort. */
4476 debug_printf_exec("run_and_free_list return %d\n", rcode);
4481 static struct pipe *new_pipe(void)
4484 pi = xzalloc(sizeof(struct pipe));
4485 /*pi->followup = 0; - deliberately invalid value */
4486 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4490 /* Command (member of a pipe) is complete, or we start a new pipe
4491 * if ctx->command is NULL.
4492 * No errors possible here.
4494 static int done_command(struct parse_context *ctx)
4496 /* The command is really already in the pipe structure, so
4497 * advance the pipe counter and make a new, null command. */
4498 struct pipe *pi = ctx->pipe;
4499 struct command *command = ctx->command;
4502 if (IS_NULL_CMD(command)) {
4503 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4507 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4508 //debug_print_tree(ctx->list_head, 20);
4510 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4513 /* Only real trickiness here is that the uncommitted
4514 * command structure is not counted in pi->num_cmds. */
4515 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4516 ctx->command = command = &pi->cmds[pi->num_cmds];
4518 memset(command, 0, sizeof(*command));
4519 return pi->num_cmds; /* used only for 0/nonzero check */
4522 static void done_pipe(struct parse_context *ctx, pipe_style type)
4526 debug_printf_parse("done_pipe entered, followup %d\n", type);
4527 /* Close previous command */
4528 not_null = done_command(ctx);
4529 ctx->pipe->followup = type;
4531 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4532 ctx->ctx_inverted = 0;
4533 ctx->pipe->res_word = ctx->ctx_res_w;
4536 /* Without this check, even just <enter> on command line generates
4537 * tree of three NOPs (!). Which is harmless but annoying.
4538 * IOW: it is safe to do it unconditionally. */
4541 || ctx->ctx_res_w == RES_FI
4543 #if ENABLE_HUSH_LOOPS
4544 || ctx->ctx_res_w == RES_DONE
4545 || ctx->ctx_res_w == RES_FOR
4546 || ctx->ctx_res_w == RES_IN
4548 #if ENABLE_HUSH_CASE
4549 || ctx->ctx_res_w == RES_ESAC
4553 debug_printf_parse("done_pipe: adding new pipe: "
4554 "not_null:%d ctx->ctx_res_w:%d\n",
4555 not_null, ctx->ctx_res_w);
4557 ctx->pipe->next = new_p;
4559 /* RES_THEN, RES_DO etc are "sticky" -
4560 * they remain set for pipes inside if/while.
4561 * This is used to control execution.
4562 * RES_FOR and RES_IN are NOT sticky (needed to support
4563 * cases where variable or value happens to match a keyword):
4565 #if ENABLE_HUSH_LOOPS
4566 if (ctx->ctx_res_w == RES_FOR
4567 || ctx->ctx_res_w == RES_IN)
4568 ctx->ctx_res_w = RES_NONE;
4570 #if ENABLE_HUSH_CASE
4571 if (ctx->ctx_res_w == RES_MATCH)
4572 ctx->ctx_res_w = RES_CASE_BODY;
4573 if (ctx->ctx_res_w == RES_CASE)
4574 ctx->ctx_res_w = RES_CASE_IN;
4576 ctx->command = NULL; /* trick done_command below */
4577 /* Create the memory for command, roughly:
4578 * ctx->pipe->cmds = new struct command;
4579 * ctx->command = &ctx->pipe->cmds[0];
4582 //debug_print_tree(ctx->list_head, 10);
4584 debug_printf_parse("done_pipe return\n");
4587 static void initialize_context(struct parse_context *ctx)
4589 memset(ctx, 0, sizeof(*ctx));
4590 ctx->pipe = ctx->list_head = new_pipe();
4591 /* Create the memory for command, roughly:
4592 * ctx->pipe->cmds = new struct command;
4593 * ctx->command = &ctx->pipe->cmds[0];
4598 /* If a reserved word is found and processed, parse context is modified
4599 * and 1 is returned.
4602 struct reserved_combo {
4605 unsigned char assignment_flag;
4609 FLAG_END = (1 << RES_NONE ),
4611 FLAG_IF = (1 << RES_IF ),
4612 FLAG_THEN = (1 << RES_THEN ),
4613 FLAG_ELIF = (1 << RES_ELIF ),
4614 FLAG_ELSE = (1 << RES_ELSE ),
4615 FLAG_FI = (1 << RES_FI ),
4617 #if ENABLE_HUSH_LOOPS
4618 FLAG_FOR = (1 << RES_FOR ),
4619 FLAG_WHILE = (1 << RES_WHILE),
4620 FLAG_UNTIL = (1 << RES_UNTIL),
4621 FLAG_DO = (1 << RES_DO ),
4622 FLAG_DONE = (1 << RES_DONE ),
4623 FLAG_IN = (1 << RES_IN ),
4625 #if ENABLE_HUSH_CASE
4626 FLAG_MATCH = (1 << RES_MATCH),
4627 FLAG_ESAC = (1 << RES_ESAC ),
4629 FLAG_START = (1 << RES_XXXX ),
4632 static const struct reserved_combo* match_reserved_word(o_string *word)
4634 /* Mostly a list of accepted follow-up reserved words.
4635 * FLAG_END means we are done with the sequence, and are ready
4636 * to turn the compound list into a command.
4637 * FLAG_START means the word must start a new compound list.
4639 static const struct reserved_combo reserved_list[] = {
4641 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4642 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4643 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4644 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4645 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4646 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4648 #if ENABLE_HUSH_LOOPS
4649 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4650 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4651 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4652 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4653 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4654 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4656 #if ENABLE_HUSH_CASE
4657 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4658 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4661 const struct reserved_combo *r;
4663 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4664 if (strcmp(word->data, r->literal) == 0)
4669 /* Return 0: not a keyword, 1: keyword
4671 static int reserved_word(o_string *word, struct parse_context *ctx)
4673 #if ENABLE_HUSH_CASE
4674 static const struct reserved_combo reserved_match = {
4675 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4678 const struct reserved_combo *r;
4682 r = match_reserved_word(word);
4686 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4687 #if ENABLE_HUSH_CASE
4688 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
4689 /* "case word IN ..." - IN part starts first MATCH part */
4690 r = &reserved_match;
4693 if (r->flag == 0) { /* '!' */
4694 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4695 syntax_error("! ! command");
4696 ctx->ctx_res_w = RES_SNTX;
4698 ctx->ctx_inverted = 1;
4701 if (r->flag & FLAG_START) {
4702 struct parse_context *old;
4704 old = xmalloc(sizeof(*old));
4705 debug_printf_parse("push stack %p\n", old);
4706 *old = *ctx; /* physical copy */
4707 initialize_context(ctx);
4709 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4710 syntax_error_at(word->data);
4711 ctx->ctx_res_w = RES_SNTX;
4714 /* "{...} fi" is ok. "{...} if" is not
4716 * if { echo foo; } then { echo bar; } fi */
4717 if (ctx->command->group)
4718 done_pipe(ctx, PIPE_SEQ);
4721 ctx->ctx_res_w = r->res;
4722 ctx->old_flag = r->flag;
4723 word->o_assignment = r->assignment_flag;
4725 if (ctx->old_flag & FLAG_END) {
4726 struct parse_context *old;
4728 done_pipe(ctx, PIPE_SEQ);
4729 debug_printf_parse("pop stack %p\n", ctx->stack);
4731 old->command->group = ctx->list_head;
4732 old->command->cmd_type = CMD_NORMAL;
4734 o_addstr(&old->as_string, ctx->as_string.data);
4735 o_free_unsafe(&ctx->as_string);
4736 old->command->group_as_string = xstrdup(old->as_string.data);
4737 debug_printf_parse("pop, remembering as:'%s'\n",
4738 old->command->group_as_string);
4740 *ctx = *old; /* physical copy */
4747 /* Word is complete, look at it and update parsing context.
4748 * Normal return is 0. Syntax errors return 1.
4749 * Note: on return, word is reset, but not o_free'd!
4751 static int done_word(o_string *word, struct parse_context *ctx)
4753 struct command *command = ctx->command;
4755 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4756 if (word->length == 0 && word->o_quoted == 0) {
4757 debug_printf_parse("done_word return 0: true null, ignored\n");
4761 if (ctx->pending_redirect) {
4762 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4763 * only if run as "bash", not "sh" */
4764 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4766 * ...the word that follows the redirection operator
4767 * shall be subjected to tilde expansion, parameter expansion,
4768 * command substitution, arithmetic expansion, and quote
4769 * removal. Pathname expansion shall not be performed
4770 * on the word by a non-interactive shell; an interactive
4771 * shell may perform it, but shall do so only when
4772 * the expansion would result in one word."
4774 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4775 /* Cater for >\file case:
4776 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4777 * Same with heredocs:
4778 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4780 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
4781 unbackslash(ctx->pending_redirect->rd_filename);
4782 /* Is it <<"HEREDOC"? */
4783 if (word->o_quoted) {
4784 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4787 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4788 ctx->pending_redirect = NULL;
4790 /* If this word wasn't an assignment, next ones definitely
4791 * can't be assignments. Even if they look like ones. */
4792 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4793 && word->o_assignment != WORD_IS_KEYWORD
4795 word->o_assignment = NOT_ASSIGNMENT;
4797 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4798 command->assignment_cnt++;
4799 word->o_assignment = MAYBE_ASSIGNMENT;
4803 # if ENABLE_HUSH_CASE
4804 if (ctx->ctx_dsemicolon
4805 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4807 /* already done when ctx_dsemicolon was set to 1: */
4808 /* ctx->ctx_res_w = RES_MATCH; */
4809 ctx->ctx_dsemicolon = 0;
4812 if (!command->argv /* if it's the first word... */
4813 # if ENABLE_HUSH_LOOPS
4814 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4815 && ctx->ctx_res_w != RES_IN
4817 # if ENABLE_HUSH_CASE
4818 && ctx->ctx_res_w != RES_CASE
4821 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4822 if (reserved_word(word, ctx)) {
4823 o_reset_to_empty_unquoted(word);
4824 debug_printf_parse("done_word return %d\n",
4825 (ctx->ctx_res_w == RES_SNTX));
4826 return (ctx->ctx_res_w == RES_SNTX);
4828 # ifdef CMD_SINGLEWORD_NOGLOB_COND
4829 if (strcmp(word->data, "export") == 0
4830 # if ENABLE_HUSH_LOCAL
4831 || strcmp(word->data, "local") == 0
4834 command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
4837 # if ENABLE_HUSH_BASH_COMPAT
4838 if (strcmp(word->data, "[[") == 0) {
4839 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
4845 if (command->group) {
4846 /* "{ echo foo; } echo bar" - bad */
4847 syntax_error_at(word->data);
4848 debug_printf_parse("done_word return 1: syntax error, "
4849 "groups and arglists don't mix\n");
4852 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4853 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4854 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4855 /* (otherwise it's known to be not empty and is already safe) */
4857 /* exclude "$@" - it can expand to no word despite "" */
4858 char *p = word->data;
4859 while (p[0] == SPECIAL_VAR_SYMBOL
4860 && (p[1] & 0x7f) == '@'
4861 && p[2] == SPECIAL_VAR_SYMBOL
4865 if (p == word->data || p[0] != '\0') {
4866 /* saw no "$@", or not only "$@" but some
4867 * real text is there too */
4868 /* insert "empty variable" reference, this makes
4869 * e.g. "", $empty"" etc to not disappear */
4870 o_addchr(word, SPECIAL_VAR_SYMBOL);
4871 o_addchr(word, SPECIAL_VAR_SYMBOL);
4874 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4875 debug_print_strings("word appended to argv", command->argv);
4878 #if ENABLE_HUSH_LOOPS
4879 if (ctx->ctx_res_w == RES_FOR) {
4881 || !is_well_formed_var_name(command->argv[0], '\0')
4883 /* bash says just "not a valid identifier" */
4884 syntax_error("not a valid identifier in for");
4887 /* Force FOR to have just one word (variable name) */
4888 /* NB: basically, this makes hush see "for v in ..."
4889 * syntax as if it is "for v; in ...". FOR and IN become
4890 * two pipe structs in parse tree. */
4891 done_pipe(ctx, PIPE_SEQ);
4894 #if ENABLE_HUSH_CASE
4895 /* Force CASE to have just one word */
4896 if (ctx->ctx_res_w == RES_CASE) {
4897 done_pipe(ctx, PIPE_SEQ);
4901 o_reset_to_empty_unquoted(word);
4903 debug_printf_parse("done_word return 0\n");
4908 /* Peek ahead in the input to find out if we have a "&n" construct,
4909 * as in "2>&1", that represents duplicating a file descriptor.
4911 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4912 * REDIRFD_SYNTAX_ERR if syntax error,
4913 * REDIRFD_TO_FILE if no & was seen,
4914 * or the number found.
4917 #define parse_redir_right_fd(as_string, input) \
4918 parse_redir_right_fd(input)
4920 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4926 return REDIRFD_TO_FILE;
4928 ch = i_getch(input); /* get the & */
4929 nommu_addchr(as_string, ch);
4932 ch = i_getch(input);
4933 nommu_addchr(as_string, ch);
4934 return REDIRFD_CLOSE;
4938 while (ch != EOF && isdigit(ch)) {
4939 d = d*10 + (ch-'0');
4941 ch = i_getch(input);
4942 nommu_addchr(as_string, ch);
4947 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4949 bb_error_msg("ambiguous redirect");
4950 return REDIRFD_SYNTAX_ERR;
4953 /* Return code is 0 normal, 1 if a syntax error is detected
4955 static int parse_redirect(struct parse_context *ctx,
4958 struct in_str *input)
4960 struct command *command = ctx->command;
4961 struct redir_struct *redir;
4962 struct redir_struct **redirp;
4965 dup_num = REDIRFD_TO_FILE;
4966 if (style != REDIRECT_HEREDOC) {
4967 /* Check for a '>&1' type redirect */
4968 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4969 if (dup_num == REDIRFD_SYNTAX_ERR)
4972 int ch = i_peek(input);
4973 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4974 if (dup_num) { /* <<-... */
4975 ch = i_getch(input);
4976 nommu_addchr(&ctx->as_string, ch);
4981 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4982 int ch = i_peek(input);
4984 /* >|FILE redirect ("clobbering" >).
4985 * Since we do not support "set -o noclobber" yet,
4986 * >| and > are the same for now. Just eat |.
4988 ch = i_getch(input);
4989 nommu_addchr(&ctx->as_string, ch);
4993 /* Create a new redir_struct and append it to the linked list */
4994 redirp = &command->redirects;
4995 while ((redir = *redirp) != NULL) {
4996 redirp = &(redir->next);
4998 *redirp = redir = xzalloc(sizeof(*redir));
4999 /* redir->next = NULL; */
5000 /* redir->rd_filename = NULL; */
5001 redir->rd_type = style;
5002 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
5004 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
5005 redir_table[style].descrip);
5007 redir->rd_dup = dup_num;
5008 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
5009 /* Erik had a check here that the file descriptor in question
5010 * is legit; I postpone that to "run time"
5011 * A "-" representation of "close me" shows up as a -3 here */
5012 debug_printf_parse("duplicating redirect '%d>&%d'\n",
5013 redir->rd_fd, redir->rd_dup);
5015 /* Set ctx->pending_redirect, so we know what to do at the
5016 * end of the next parsed word. */
5017 ctx->pending_redirect = redir;
5022 /* If a redirect is immediately preceded by a number, that number is
5023 * supposed to tell which file descriptor to redirect. This routine
5024 * looks for such preceding numbers. In an ideal world this routine
5025 * needs to handle all the following classes of redirects...
5026 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
5027 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
5028 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
5029 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
5031 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
5033 * ... If n is quoted, the number shall not be recognized as part of
5034 * the redirection expression. For example:
5036 * writes the character 2 into file a"
5037 * We are getting it right by setting ->o_quoted on any \<char>
5039 * A -1 return means no valid number was found,
5040 * the caller should use the appropriate default for this redirection.
5042 static int redirect_opt_num(o_string *o)
5046 if (o->data == NULL)
5048 num = bb_strtou(o->data, NULL, 10);
5049 if (errno || num < 0)
5051 o_reset_to_empty_unquoted(o);
5056 #define fetch_till_str(as_string, input, word, skip_tabs) \
5057 fetch_till_str(input, word, skip_tabs)
5059 static char *fetch_till_str(o_string *as_string,
5060 struct in_str *input,
5064 o_string heredoc = NULL_O_STRING;
5070 ch = i_getch(input);
5071 nommu_addchr(as_string, ch);
5073 if (strcmp(heredoc.data + past_EOL, word) == 0) {
5074 heredoc.data[past_EOL] = '\0';
5075 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
5076 return heredoc.data;
5079 o_addchr(&heredoc, ch);
5080 past_EOL = heredoc.length;
5083 ch = i_getch(input);
5084 nommu_addchr(as_string, ch);
5085 } while (skip_tabs && ch == '\t');
5086 } while (ch == '\n');
5089 o_free_unsafe(&heredoc);
5092 o_addchr(&heredoc, ch);
5093 nommu_addchr(as_string, ch);
5097 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
5098 * and load them all. There should be exactly heredoc_cnt of them.
5100 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
5102 struct pipe *pi = ctx->list_head;
5104 while (pi && heredoc_cnt) {
5106 struct command *cmd = pi->cmds;
5108 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
5110 cmd->argv ? cmd->argv[0] : "NONE");
5111 for (i = 0; i < pi->num_cmds; i++) {
5112 struct redir_struct *redir = cmd->redirects;
5114 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
5115 i, cmd->argv ? cmd->argv[0] : "NONE");
5117 if (redir->rd_type == REDIRECT_HEREDOC) {
5120 redir->rd_type = REDIRECT_HEREDOC2;
5121 /* redir->rd_dup is (ab)used to indicate <<- */
5122 p = fetch_till_str(&ctx->as_string, input,
5123 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
5125 syntax_error("unexpected EOF in here document");
5128 free(redir->rd_filename);
5129 redir->rd_filename = p;
5132 redir = redir->next;
5139 /* Should be 0. If it isn't, it's a parse error */
5141 bb_error_msg_and_die("heredoc BUG 2");
5147 #if ENABLE_HUSH_TICK
5148 static FILE *generate_stream_from_string(const char *s)
5151 int pid, channel[2];
5157 pid = BB_MMU ? fork() : vfork();
5159 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
5161 if (pid == 0) { /* child */
5162 disable_restore_tty_pgrp_on_exit();
5163 /* Process substitution is not considered to be usual
5164 * 'command execution'.
5165 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5172 close(channel[0]); /* NB: close _first_, then move fd! */
5173 xmove_fd(channel[1], 1);
5174 /* Prevent it from trying to handle ctrl-z etc */
5175 IF_HUSH_JOB(G.run_list_level = 1;)
5177 reset_traps_to_defaults();
5178 parse_and_run_string(s);
5179 _exit(G.last_exitcode);
5181 /* We re-execute after vfork on NOMMU. This makes this script safe:
5182 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5183 * huge=`cat BIG` # was blocking here forever
5186 re_execute_shell(&to_free,
5195 #if ENABLE_HUSH_FAST
5197 //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);
5199 enable_restore_tty_pgrp_on_exit();
5204 pf = fdopen(channel[0], "r");
5208 /* Return code is exit status of the process that is run. */
5209 static int process_command_subs(o_string *dest, const char *s)
5212 struct in_str pipe_str;
5215 pf = generate_stream_from_string(s);
5218 close_on_exec_on(fileno(pf));
5220 /* Now send results of command back into original context */
5221 setup_file_in_str(&pipe_str, pf);
5223 while ((ch = i_getch(&pipe_str)) != EOF) {
5229 o_addchr(dest, '\n');
5232 o_addQchr(dest, ch);
5235 debug_printf("done reading from pipe, pclose()ing\n");
5236 /* Note: we got EOF, and we just close the read end of the pipe.
5237 * We do not wait for the `cmd` child to terminate. bash and ash do.
5239 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
5240 * `false`; echo $? - bash outputs "1"
5243 debug_printf("closed FILE from child. return 0\n");
5248 static int parse_group(o_string *dest, struct parse_context *ctx,
5249 struct in_str *input, int ch)
5251 /* dest contains characters seen prior to ( or {.
5252 * Typically it's empty, but for function defs,
5253 * it contains function name (without '()'). */
5254 struct pipe *pipe_list;
5256 struct command *command = ctx->command;
5258 debug_printf_parse("parse_group entered\n");
5259 #if ENABLE_HUSH_FUNCTIONS
5260 if (ch == '(' && !dest->o_quoted) {
5262 if (done_word(dest, ctx))
5265 goto skip; /* (... */
5266 if (command->argv[1]) { /* word word ... (... */
5267 syntax_error_unexpected_ch('(');
5270 /* it is "word(..." or "word (..." */
5272 ch = i_getch(input);
5273 while (ch == ' ' || ch == '\t');
5275 syntax_error_unexpected_ch(ch);
5278 nommu_addchr(&ctx->as_string, ch);
5280 ch = i_getch(input);
5281 while (ch == ' ' || ch == '\t' || ch == '\n');
5283 syntax_error_unexpected_ch(ch);
5286 nommu_addchr(&ctx->as_string, ch);
5287 command->cmd_type = CMD_FUNCDEF;
5291 if (command->argv /* word [word]{... */
5292 || dest->length /* word{... */
5293 || dest->o_quoted /* ""{... */
5296 debug_printf_parse("parse_group return 1: "
5297 "syntax error, groups and arglists don't mix\n");
5301 #if ENABLE_HUSH_FUNCTIONS
5307 command->cmd_type = CMD_SUBSHELL;
5309 /* bash does not allow "{echo...", requires whitespace */
5310 ch = i_getch(input);
5311 if (ch != ' ' && ch != '\t' && ch != '\n') {
5312 syntax_error_unexpected_ch(ch);
5315 nommu_addchr(&ctx->as_string, ch);
5320 char *as_string = NULL;
5322 pipe_list = parse_stream(&as_string, input, endch);
5325 o_addstr(&ctx->as_string, as_string);
5327 /* empty ()/{} or parse error? */
5328 if (!pipe_list || pipe_list == ERR_PTR) {
5329 /* parse_stream already emitted error msg */
5333 debug_printf_parse("parse_group return 1: "
5334 "parse_stream returned %p\n", pipe_list);
5337 command->group = pipe_list;
5339 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
5340 command->group_as_string = as_string;
5341 debug_printf_parse("end of group, remembering as:'%s'\n",
5342 command->group_as_string);
5345 debug_printf_parse("parse_group return 0\n");
5347 /* command remains "open", available for possible redirects */
5350 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
5351 /* Subroutines for copying $(...) and `...` things */
5352 static void add_till_backquote(o_string *dest, struct in_str *input);
5354 static void add_till_single_quote(o_string *dest, struct in_str *input)
5357 int ch = i_getch(input);
5359 syntax_error_unterm_ch('\'');
5360 /*xfunc_die(); - redundant */
5367 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
5368 static void add_till_double_quote(o_string *dest, struct in_str *input)
5371 int ch = i_getch(input);
5373 syntax_error_unterm_ch('"');
5374 /*xfunc_die(); - redundant */
5378 if (ch == '\\') { /* \x. Copy both chars. */
5380 ch = i_getch(input);
5384 add_till_backquote(dest, input);
5388 //if (ch == '$') ...
5391 /* Process `cmd` - copy contents until "`" is seen. Complicated by
5393 * "Within the backquoted style of command substitution, backslash
5394 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
5395 * The search for the matching backquote shall be satisfied by the first
5396 * backquote found without a preceding backslash; during this search,
5397 * if a non-escaped backquote is encountered within a shell comment,
5398 * a here-document, an embedded command substitution of the $(command)
5399 * form, or a quoted string, undefined results occur. A single-quoted
5400 * or double-quoted string that begins, but does not end, within the
5401 * "`...`" sequence produces undefined results."
5403 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
5405 static void add_till_backquote(o_string *dest, struct in_str *input)
5408 int ch = i_getch(input);
5410 syntax_error_unterm_ch('`');
5411 /*xfunc_die(); - redundant */
5416 /* \x. Copy both chars unless it is \` */
5417 int ch2 = i_getch(input);
5419 syntax_error_unterm_ch('`');
5420 /*xfunc_die(); - redundant */
5422 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5429 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5430 * quoting and nested ()s.
5431 * "With the $(command) style of command substitution, all characters
5432 * following the open parenthesis to the matching closing parenthesis
5433 * constitute the command. Any valid shell script can be used for command,
5434 * except a script consisting solely of redirections which produces
5435 * unspecified results."
5437 * echo $(echo '(TEST)' BEST) (TEST) BEST
5438 * echo $(echo 'TEST)' BEST) TEST) BEST
5439 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5441 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5445 int ch = i_getch(input);
5447 syntax_error_unterm_ch(')');
5448 /*xfunc_die(); - redundant */
5456 if (i_peek(input) == ')') {
5464 add_till_single_quote(dest, input);
5469 add_till_double_quote(dest, input);
5474 /* \x. Copy verbatim. Important for \(, \) */
5475 ch = i_getch(input);
5477 syntax_error_unterm_ch(')');
5478 /*xfunc_die(); - redundant */
5485 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5487 /* Return code: 0 for OK, 1 for syntax error */
5489 #define handle_dollar(as_string, dest, input) \
5490 handle_dollar(dest, input)
5492 static int handle_dollar(o_string *as_string,
5494 struct in_str *input)
5496 int ch = i_peek(input); /* first character after the $ */
5497 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5499 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5501 ch = i_getch(input);
5502 nommu_addchr(as_string, ch);
5504 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5506 debug_printf_parse(": '%c'\n", ch);
5507 o_addchr(dest, ch | quote_mask);
5510 if (!isalnum(ch) && ch != '_')
5512 ch = i_getch(input);
5513 nommu_addchr(as_string, ch);
5515 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5516 } else if (isdigit(ch)) {
5518 ch = i_getch(input);
5519 nommu_addchr(as_string, ch);
5520 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5521 debug_printf_parse(": '%c'\n", ch);
5522 o_addchr(dest, ch | quote_mask);
5523 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5524 } else switch (ch) {
5526 case '!': /* last bg pid */
5527 case '?': /* last exit code */
5528 case '#': /* number of args */
5529 case '*': /* args */
5530 case '@': /* args */
5531 goto make_one_char_var;
5533 bool first_char, all_digits;
5536 ch = i_getch(input);
5537 nommu_addchr(as_string, ch);
5538 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5540 /* TODO: maybe someone will try to escape the '}' */
5545 ch = i_getch(input);
5546 nommu_addchr(as_string, ch);
5553 /* ${#var}: length of var contents */
5560 /* They're being verbose and doing ${?} */
5561 if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
5566 && ( (all_digits && !isdigit(ch))
5567 || (!all_digits && !isalnum(ch) && ch != '_')
5570 /* handle parameter expansions
5571 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5576 case ':': /* null modifier */
5577 if (expansion == 0) {
5578 debug_printf_parse(": null modifier\n");
5583 case '#': /* remove prefix */
5584 case '%': /* remove suffix */
5585 if (expansion == 0) {
5586 debug_printf_parse(": remove suffix/prefix\n");
5591 case '-': /* default value */
5592 case '=': /* assign default */
5593 case '+': /* alternative */
5594 case '?': /* error indicate */
5595 debug_printf_parse(": parameter expansion\n");
5600 syntax_error_unterm_str("${name}");
5601 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5606 debug_printf_parse(": '%c'\n", ch);
5607 o_addchr(dest, ch | quote_mask);
5611 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5614 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5619 ch = i_getch(input);
5620 nommu_addchr(as_string, ch);
5621 # if ENABLE_SH_MATH_SUPPORT
5622 if (i_peek(input) == '(') {
5623 ch = i_getch(input);
5624 nommu_addchr(as_string, ch);
5625 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5626 o_addchr(dest, /*quote_mask |*/ '+');
5630 add_till_closing_paren(dest, input, true);
5633 o_addstr(as_string, dest->data + pos);
5634 o_addchr(as_string, ')');
5635 o_addchr(as_string, ')');
5638 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5642 # if ENABLE_HUSH_TICK
5643 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5644 o_addchr(dest, quote_mask | '`');
5648 add_till_closing_paren(dest, input, false);
5651 o_addstr(as_string, dest->data + pos);
5652 o_addchr(as_string, '`');
5655 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5661 ch = i_getch(input);
5662 nommu_addchr(as_string, ch);
5664 if (isalnum(ch)) { /* it's $_name or $_123 */
5670 /* $_ Shell or shell script name; or last cmd name */
5671 /* $- Option flags set by set builtin or shell options (-i etc) */
5673 o_addQchr(dest, '$');
5675 debug_printf_parse("handle_dollar return 0\n");
5680 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5681 parse_stream_dquoted(dest, input, dquote_end)
5683 static int parse_stream_dquoted(o_string *as_string,
5685 struct in_str *input,
5692 ch = i_getch(input);
5694 nommu_addchr(as_string, ch);
5695 if (ch == dquote_end) { /* may be only '"' or EOF */
5696 if (dest->o_assignment == NOT_ASSIGNMENT)
5697 dest->o_escape ^= 1;
5698 debug_printf_parse("parse_stream_dquoted return 0\n");
5701 /* note: can't move it above ch == dquote_end check! */
5703 syntax_error_unterm_ch('"');
5704 /*xfunc_die(); - redundant */
5708 next = i_peek(input);
5710 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5711 ch, ch, dest->o_escape);
5714 syntax_error("\\<eof>");
5718 * "The backslash retains its special meaning [in "..."]
5719 * only when followed by one of the following characters:
5720 * $, `, ", \, or <newline>. A double quote may be quoted
5721 * within double quotes by preceding it with a backslash."
5723 if (strchr("$`\"\\\n", next) != NULL) {
5724 ch = i_getch(input);
5726 o_addqchr(dest, ch);
5727 nommu_addchr(as_string, ch);
5730 o_addqchr(dest, '\\');
5731 nommu_addchr(as_string, '\\');
5736 if (handle_dollar(as_string, dest, input) != 0) {
5737 debug_printf_parse("parse_stream_dquoted return 1: "
5738 "handle_dollar returned non-0\n");
5743 #if ENABLE_HUSH_TICK
5745 //int pos = dest->length;
5746 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5747 o_addchr(dest, 0x80 | '`');
5748 add_till_backquote(dest, input);
5749 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5750 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5754 o_addQchr(dest, ch);
5756 && (dest->o_assignment == MAYBE_ASSIGNMENT
5757 || dest->o_assignment == WORD_IS_KEYWORD)
5758 && is_well_formed_var_name(dest->data, '=')
5760 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5766 * Scan input until EOF or end_trigger char.
5767 * Return a list of pipes to execute, or NULL on EOF
5768 * or if end_trigger character is met.
5769 * On syntax error, exit is shell is not interactive,
5770 * reset parsing machinery and start parsing anew,
5771 * or return ERR_PTR.
5773 static struct pipe *parse_stream(char **pstring,
5774 struct in_str *input,
5777 struct parse_context ctx;
5778 o_string dest = NULL_O_STRING;
5782 /* Double-quote state is handled in the state variable is_in_dquote.
5783 * A single-quote triggers a bypass of the main loop until its mate is
5784 * found. When recursing, quote state is passed in via dest->o_escape.
5786 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5787 end_trigger ? : 'X');
5790 G.ifs = get_local_var_value("IFS");
5795 #if ENABLE_HUSH_INTERACTIVE
5796 input->promptmode = 0; /* PS1 */
5798 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5799 initialize_context(&ctx);
5804 const char *is_special;
5808 redir_type redir_style;
5811 /* dest.o_quoted = 1; - already is (see below) */
5812 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5815 /* We reached closing '"' */
5818 ch = i_getch(input);
5819 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5820 ch, ch, dest.o_escape);
5825 syntax_error_unterm_str("here document");
5828 /* end_trigger == '}' case errors out earlier,
5829 * checking only ')' */
5830 if (end_trigger == ')') {
5831 syntax_error_unterm_ch('('); /* exits */
5832 /* goto parse_error; */
5835 if (done_word(&dest, &ctx)) {
5839 done_pipe(&ctx, PIPE_SEQ);
5841 /* If we got nothing... */
5842 /* (this makes bare "&" cmd a no-op.
5843 * bash says: "syntax error near unexpected token '&'") */
5844 if (pi->num_cmds == 0
5845 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5851 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5853 *pstring = ctx.as_string.data;
5855 o_free_unsafe(&ctx.as_string);
5858 debug_printf_parse("parse_stream return %p\n", pi);
5861 nommu_addchr(&ctx.as_string, ch);
5862 is_ifs = strchr(G.ifs, ch);
5863 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5864 "\\$\"" IF_HUSH_TICK("`") /* always special */
5867 if (!is_special && !is_ifs) { /* ordinary char */
5869 o_addQchr(&dest, ch);
5870 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5871 || dest.o_assignment == WORD_IS_KEYWORD)
5873 && is_well_formed_var_name(dest.data, '=')
5875 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5881 if (done_word(&dest, &ctx)) {
5885 #if ENABLE_HUSH_CASE
5886 /* "case ... in <newline> word) ..." -
5887 * newlines are ignored (but ';' wouldn't be) */
5888 if (ctx.command->argv == NULL
5889 && ctx.ctx_res_w == RES_MATCH
5894 /* Treat newline as a command separator. */
5895 done_pipe(&ctx, PIPE_SEQ);
5896 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5898 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5903 dest.o_assignment = MAYBE_ASSIGNMENT;
5905 /* note: if (is_ifs) continue;
5906 * will still trigger for us */
5910 /* "cmd}" or "cmd }..." without semicolon or &:
5911 * } is an ordinary char in this case, even inside { cmd; }
5912 * Pathological example: { ""}; } should exec "}" cmd
5915 if (!IS_NULL_CMD(ctx.command) /* cmd } */
5916 || dest.length != 0 /* word} */
5917 || dest.o_quoted /* ""} */
5921 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5922 goto skip_end_trigger;
5923 /* else: } does terminate a group */
5926 if (end_trigger && end_trigger == ch
5927 && (ch != ';' || heredoc_cnt == 0)
5928 #if ENABLE_HUSH_CASE
5930 || ctx.ctx_res_w != RES_MATCH
5931 || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
5936 /* This is technically valid:
5937 * { cat <<HERE; }; echo Ok
5941 * but we don't support this.
5942 * We require heredoc to be in enclosing {}/(),
5945 syntax_error_unterm_str("here document");
5948 if (done_word(&dest, &ctx)) {
5951 done_pipe(&ctx, PIPE_SEQ);
5952 dest.o_assignment = MAYBE_ASSIGNMENT;
5953 /* Do we sit outside of any if's, loops or case's? */
5955 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5959 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5961 *pstring = ctx.as_string.data;
5963 o_free_unsafe(&ctx.as_string);
5966 debug_printf_parse("parse_stream return %p: "
5967 "end_trigger char found\n",
5969 return ctx.list_head;
5978 next = i_peek(input);
5981 /* Catch <, > before deciding whether this word is
5982 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5985 redir_fd = redirect_opt_num(&dest);
5986 if (done_word(&dest, &ctx)) {
5989 redir_style = REDIRECT_OVERWRITE;
5991 redir_style = REDIRECT_APPEND;
5992 ch = i_getch(input);
5993 nommu_addchr(&ctx.as_string, ch);
5996 else if (next == '(') {
5997 syntax_error(">(process) not supported");
6001 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6003 continue; /* back to top of while (1) */
6005 redir_fd = redirect_opt_num(&dest);
6006 if (done_word(&dest, &ctx)) {
6009 redir_style = REDIRECT_INPUT;
6011 redir_style = REDIRECT_HEREDOC;
6013 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
6014 ch = i_getch(input);
6015 nommu_addchr(&ctx.as_string, ch);
6016 } else if (next == '>') {
6017 redir_style = REDIRECT_IO;
6018 ch = i_getch(input);
6019 nommu_addchr(&ctx.as_string, ch);
6022 else if (next == '(') {
6023 syntax_error("<(process) not supported");
6027 if (parse_redirect(&ctx, redir_fd, redir_style, input))
6029 continue; /* back to top of while (1) */
6032 if (dest.o_assignment == MAYBE_ASSIGNMENT
6033 /* check that we are not in word in "a=1 2>word b=1": */
6034 && !ctx.pending_redirect
6036 /* ch is a special char and thus this word
6037 * cannot be an assignment */
6038 dest.o_assignment = NOT_ASSIGNMENT;
6041 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
6045 if (dest.length == 0) {
6048 if (ch == EOF || ch == '\n')
6051 /* note: we do not add it to &ctx.as_string */
6053 nommu_addchr(&ctx.as_string, '\n');
6055 o_addQchr(&dest, ch);
6060 syntax_error("\\<eof>");
6063 ch = i_getch(input);
6065 o_addchr(&dest, '\\');
6066 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
6067 o_addchr(&dest, ch);
6068 nommu_addchr(&ctx.as_string, ch);
6069 /* Example: echo Hello \2>file
6070 * we need to know that word 2 is quoted */
6074 /* It's "\<newline>". Remove trailing '\' from ctx.as_string */
6075 ctx.as_string.data[--ctx.as_string.length] = '\0';
6080 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
6081 debug_printf_parse("parse_stream parse error: "
6082 "handle_dollar returned non-0\n");
6089 ch = i_getch(input);
6091 syntax_error_unterm_ch('\'');
6092 /*xfunc_die(); - redundant */
6094 nommu_addchr(&ctx.as_string, ch);
6097 o_addqchr(&dest, ch);
6102 is_in_dquote ^= 1; /* invert */
6103 if (dest.o_assignment == NOT_ASSIGNMENT)
6106 #if ENABLE_HUSH_TICK
6111 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6112 o_addchr(&dest, '`');
6116 add_till_backquote(&dest, input);
6118 o_addstr(&ctx.as_string, dest.data + pos);
6119 o_addchr(&ctx.as_string, '`');
6121 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
6122 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
6127 #if ENABLE_HUSH_CASE
6130 if (done_word(&dest, &ctx)) {
6133 done_pipe(&ctx, PIPE_SEQ);
6134 #if ENABLE_HUSH_CASE
6135 /* Eat multiple semicolons, detect
6136 * whether it means something special */
6141 ch = i_getch(input);
6142 nommu_addchr(&ctx.as_string, ch);
6143 if (ctx.ctx_res_w == RES_CASE_BODY) {
6144 ctx.ctx_dsemicolon = 1;
6145 ctx.ctx_res_w = RES_MATCH;
6151 /* We just finished a cmd. New one may start
6152 * with an assignment */
6153 dest.o_assignment = MAYBE_ASSIGNMENT;
6156 if (done_word(&dest, &ctx)) {
6160 ch = i_getch(input);
6161 nommu_addchr(&ctx.as_string, ch);
6162 done_pipe(&ctx, PIPE_AND);
6164 done_pipe(&ctx, PIPE_BG);
6168 if (done_word(&dest, &ctx)) {
6171 #if ENABLE_HUSH_CASE
6172 if (ctx.ctx_res_w == RES_MATCH)
6173 break; /* we are in case's "word | word)" */
6175 if (next == '|') { /* || */
6176 ch = i_getch(input);
6177 nommu_addchr(&ctx.as_string, ch);
6178 done_pipe(&ctx, PIPE_OR);
6180 /* we could pick up a file descriptor choice here
6181 * with redirect_opt_num(), but bash doesn't do it.
6182 * "echo foo 2| cat" yields "foo 2". */
6187 #if ENABLE_HUSH_CASE
6188 /* "case... in [(]word)..." - skip '(' */
6189 if (ctx.ctx_res_w == RES_MATCH
6190 && ctx.command->argv == NULL /* not (word|(... */
6191 && dest.length == 0 /* not word(... */
6192 && dest.o_quoted == 0 /* not ""(... */
6198 if (parse_group(&dest, &ctx, input, ch) != 0) {
6203 #if ENABLE_HUSH_CASE
6204 if (ctx.ctx_res_w == RES_MATCH)
6208 /* proper use of this character is caught by end_trigger:
6209 * if we see {, we call parse_group(..., end_trigger='}')
6210 * and it will match } earlier (not here). */
6211 syntax_error_unexpected_ch(ch);
6215 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
6221 struct parse_context *pctx;
6222 IF_HAS_KEYWORDS(struct parse_context *p2;)
6224 /* Clean up allocated tree.
6225 * Sample for finding leaks on syntax error recovery path.
6226 * Run it from interactive shell, watch pmap `pidof hush`.
6227 * while if false; then false; fi; do break; fi
6228 * Samples to catch leaks at execution:
6229 * while if (true | {true;}); then echo ok; fi; do break; done
6230 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
6234 /* Update pipe/command counts,
6235 * otherwise freeing may miss some */
6236 done_pipe(pctx, PIPE_SEQ);
6237 debug_printf_clean("freeing list %p from ctx %p\n",
6238 pctx->list_head, pctx);
6239 debug_print_tree(pctx->list_head, 0);
6240 free_pipe_list(pctx->list_head);
6241 debug_printf_clean("freed list %p\n", pctx->list_head);
6243 o_free_unsafe(&pctx->as_string);
6245 IF_HAS_KEYWORDS(p2 = pctx->stack;)
6249 IF_HAS_KEYWORDS(pctx = p2;)
6250 } while (HAS_KEYWORDS && pctx);
6251 /* Free text, clear all dest fields */
6253 /* If we are not in top-level parse, we return,
6254 * our caller will propagate error.
6256 if (end_trigger != ';') {
6264 /* Discard cached input, force prompt */
6266 IF_HUSH_INTERACTIVE(input->promptme = 1;)
6271 /* Executing from string: eval, sh -c '...'
6272 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6273 * end_trigger controls how often we stop parsing
6274 * NUL: parse all, execute, return
6275 * ';': parse till ';' or newline, execute, repeat till EOF
6277 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6280 struct pipe *pipe_list;
6282 pipe_list = parse_stream(NULL, inp, end_trigger);
6283 if (!pipe_list) /* EOF */
6285 debug_print_tree(pipe_list, 0);
6286 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6287 run_and_free_list(pipe_list);
6291 static void parse_and_run_string(const char *s)
6293 struct in_str input;
6294 setup_string_in_str(&input, s);
6295 parse_and_run_stream(&input, '\0');
6298 static void parse_and_run_file(FILE *f)
6300 struct in_str input;
6301 setup_file_in_str(&input, f);
6302 parse_and_run_stream(&input, ';');
6305 /* Called a few times only (or even once if "sh -c") */
6306 static void block_signals(int second_time)
6311 mask = (1 << SIGQUIT);
6312 if (G_interactive_fd) {
6313 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
6314 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
6315 mask |= SPECIAL_JOB_SIGS;
6317 G.non_DFL_mask = mask;
6320 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
6324 sigaddset(&G.blocked_set, sig);
6328 sigdelset(&G.blocked_set, SIGCHLD);
6330 sigprocmask(SIG_SETMASK, &G.blocked_set,
6331 second_time ? NULL : &G.inherited_set);
6332 /* POSIX allows shell to re-enable SIGCHLD
6333 * even if it was SIG_IGN on entry */
6334 #if ENABLE_HUSH_FAST
6335 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
6337 signal(SIGCHLD, SIGCHLD_handler);
6340 signal(SIGCHLD, SIG_DFL);
6346 static void maybe_set_to_sigexit(int sig)
6348 void (*handler)(int);
6349 /* non_DFL_mask'ed signals are, well, masked,
6350 * no need to set handler for them.
6352 if (!((G.non_DFL_mask >> sig) & 1)) {
6353 handler = signal(sig, sigexit);
6354 if (handler == SIG_IGN) /* oops... restore back to IGN! */
6355 signal(sig, handler);
6358 /* Set handlers to restore tty pgrp and exit */
6359 static void set_fatal_handlers(void)
6361 /* We _must_ restore tty pgrp on fatal signals */
6363 maybe_set_to_sigexit(SIGILL );
6364 maybe_set_to_sigexit(SIGFPE );
6365 maybe_set_to_sigexit(SIGBUS );
6366 maybe_set_to_sigexit(SIGSEGV);
6367 maybe_set_to_sigexit(SIGTRAP);
6368 } /* else: hush is perfect. what SEGV? */
6369 maybe_set_to_sigexit(SIGABRT);
6370 /* bash 3.2 seems to handle these just like 'fatal' ones */
6371 maybe_set_to_sigexit(SIGPIPE);
6372 maybe_set_to_sigexit(SIGALRM);
6373 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
6374 * if we aren't interactive... but in this case
6375 * we never want to restore pgrp on exit, and this fn is not called */
6376 /*maybe_set_to_sigexit(SIGHUP );*/
6377 /*maybe_set_to_sigexit(SIGTERM);*/
6378 /*maybe_set_to_sigexit(SIGINT );*/
6382 static int set_mode(const char cstate, const char mode)
6384 int state = (cstate == '-' ? 1 : 0);
6386 case 'n': G.fake_mode = state; break;
6387 case 'x': /*G.debug_mode = state;*/ break;
6388 default: return EXIT_FAILURE;
6390 return EXIT_SUCCESS;
6393 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6394 int hush_main(int argc, char **argv)
6396 static const struct variable const_shell_ver = {
6398 .varstr = (char*)hush_version_str,
6399 .max_len = 1, /* 0 can provoke free(name) */
6403 int signal_mask_is_inited = 0;
6405 unsigned builtin_argc;
6407 struct variable *cur_var;
6410 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
6411 G.last_exitcode = EXIT_SUCCESS;
6413 G.argv0_for_re_execing = argv[0];
6415 /* Deal with HUSH_VERSION */
6416 G.shell_ver = const_shell_ver; /* copying struct here */
6417 G.top_var = &G.shell_ver;
6418 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
6419 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
6420 /* Initialize our shell local variables with the values
6421 * currently living in the environment */
6422 cur_var = G.top_var;
6425 char *value = strchr(*e, '=');
6426 if (value) { /* paranoia */
6427 cur_var->next = xzalloc(sizeof(*cur_var));
6428 cur_var = cur_var->next;
6429 cur_var->varstr = *e;
6430 cur_var->max_len = strlen(*e);
6431 cur_var->flg_export = 1;
6435 debug_printf_env("putenv '%s'\n", hush_version_str);
6436 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
6437 #if ENABLE_FEATURE_EDITING
6438 G.line_input_state = new_line_input_t(FOR_SHELL);
6440 G.global_argc = argc;
6441 G.global_argv = argv;
6442 /* Initialize some more globals to non-zero values */
6443 cmdedit_update_prompt();
6445 if (setjmp(die_jmp)) {
6446 /* xfunc has failed! die die die */
6447 /* no EXIT traps, this is an escape hatch! */
6449 hush_exit(xfunc_error_retval);
6452 /* Shell is non-interactive at first. We need to call
6453 * block_signals(0) if we are going to execute "sh <script>",
6454 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6455 * If we later decide that we are interactive, we run block_signals(0)
6456 * (or re-run block_signals(1) if we ran block_signals(0) before)
6457 * in order to intercept (more) signals.
6461 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6464 opt = getopt(argc, argv, "+c:xins"
6467 # if ENABLE_HUSH_FUNCTIONS
6477 * sh ... -c 'script'
6478 * sh ... -c 'script' ARG0 [ARG1...]
6479 * On NOMMU, if builtin_argc != 0,
6480 * sh ... -c 'builtin' [BARGV...] "" ARG0 [ARG1...]
6481 * "" needs to be replaced with NULL
6482 * and BARGV vector fed to builtin function.
6483 * Note: this form never happens:
6484 * sh ... -c 'builtin' [BARGV...] ""
6487 G.root_pid = getpid();
6488 G.global_argv = argv + optind;
6489 G.global_argc = argc - optind;
6491 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
6492 const struct built_in_command *x;
6494 block_signals(0); /* 0: called 1st time */
6495 x = find_builtin(optarg);
6496 if (x) { /* paranoia */
6497 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
6498 G.global_argv += builtin_argc;
6499 G.global_argv[-1] = NULL; /* replace "" */
6500 G.last_exitcode = x->function(argv + optind - 1);
6504 if (!G.global_argv[0]) {
6505 /* -c 'script' (no params): prevent empty $0 */
6506 G.global_argv--; /* points to argv[i] of 'script' */
6507 G.global_argv[0] = argv[0];
6509 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
6510 block_signals(0); /* 0: called 1st time */
6511 parse_and_run_string(optarg);
6514 /* Well, we cannot just declare interactiveness,
6515 * we have to have some stuff (ctty, etc) */
6516 /* G_interactive_fd++; */
6519 /* "-s" means "read from stdin", but this is how we always
6520 * operate, so simply do nothing here. */
6523 case '<': /* "big heredoc" support */
6524 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6527 G.root_pid = bb_strtou(optarg, &optarg, 16);
6529 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6531 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6533 builtin_argc = bb_strtou(optarg, &optarg, 16);
6534 # if ENABLE_HUSH_LOOPS
6536 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6541 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
6543 # if ENABLE_HUSH_FUNCTIONS
6545 struct function *funcp = new_function(optarg);
6546 /* funcp->name is already set to optarg */
6547 /* funcp->body is set to NULL. It's a special case. */
6548 funcp->body_as_string = argv[optind];
6556 if (!set_mode('-', opt))
6560 fprintf(stderr, "Usage: sh [FILE]...\n"
6561 " or: sh -c command [args]...\n\n");
6567 } /* option parsing loop */
6570 G.root_pid = getpid();
6572 /* If we are login shell... */
6573 if (argv[0] && argv[0][0] == '-') {
6575 debug_printf("sourcing /etc/profile\n");
6576 input = fopen_for_read("/etc/profile");
6577 if (input != NULL) {
6578 close_on_exec_on(fileno(input));
6579 block_signals(0); /* 0: called 1st time */
6580 signal_mask_is_inited = 1;
6581 parse_and_run_file(input);
6584 /* bash: after sourcing /etc/profile,
6585 * tries to source (in the given order):
6586 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6587 * stopping on first found. --noprofile turns this off.
6588 * bash also sources ~/.bash_logout on exit.
6589 * If called as sh, skips .bash_XXX files.
6596 * "bash <script>" (which is never interactive (unless -i?))
6597 * sources $BASH_ENV here (without scanning $PATH).
6598 * If called as sh, does the same but with $ENV.
6600 debug_printf("running script '%s'\n", argv[optind]);
6601 G.global_argv = argv + optind;
6602 G.global_argc = argc - optind;
6603 input = xfopen_for_read(argv[optind]);
6604 close_on_exec_on(fileno(input));
6605 if (!signal_mask_is_inited)
6606 block_signals(0); /* 0: called 1st time */
6607 parse_and_run_file(input);
6608 #if ENABLE_FEATURE_CLEAN_UP
6614 /* Up to here, shell was non-interactive. Now it may become one.
6615 * NB: don't forget to (re)run block_signals(0/1) as needed.
6618 /* A shell is interactive if the '-i' flag was given,
6619 * or if all of the following conditions are met:
6621 * no arguments remaining or the -s flag given
6622 * standard input is a terminal
6623 * standard output is a terminal
6624 * Refer to Posix.2, the description of the 'sh' utility.
6627 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6628 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6629 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
6630 if (G_saved_tty_pgrp < 0)
6631 G_saved_tty_pgrp = 0;
6633 /* try to dup stdin to high fd#, >= 255 */
6634 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6635 if (G_interactive_fd < 0) {
6636 /* try to dup to any fd */
6637 G_interactive_fd = dup(STDIN_FILENO);
6638 if (G_interactive_fd < 0) {
6640 G_interactive_fd = 0;
6641 G_saved_tty_pgrp = 0;
6644 // TODO: track & disallow any attempts of user
6645 // to (inadvertently) close/redirect G_interactive_fd
6647 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6648 if (G_interactive_fd) {
6649 close_on_exec_on(G_interactive_fd);
6651 if (G_saved_tty_pgrp) {
6652 /* If we were run as 'hush &', sleep until we are
6653 * in the foreground (tty pgrp == our pgrp).
6654 * If we get started under a job aware app (like bash),
6655 * make sure we are now in charge so we don't fight over
6656 * who gets the foreground */
6658 pid_t shell_pgrp = getpgrp();
6659 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6660 if (G_saved_tty_pgrp == shell_pgrp)
6662 /* send TTIN to ourself (should stop us) */
6663 kill(- shell_pgrp, SIGTTIN);
6667 /* Block some signals */
6668 block_signals(signal_mask_is_inited);
6670 if (G_saved_tty_pgrp) {
6671 /* Set other signals to restore saved_tty_pgrp */
6672 set_fatal_handlers();
6673 /* Put ourselves in our own process group
6674 * (bash, too, does this only if ctty is available) */
6675 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6676 /* Grab control of the terminal */
6677 tcsetpgrp(G_interactive_fd, getpid());
6679 /* -1 is special - makes xfuncs longjmp, not exit
6680 * (we reset die_sleep = 0 whereever we [v]fork) */
6681 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6682 } else if (!signal_mask_is_inited) {
6683 block_signals(0); /* 0: called 1st time */
6684 } /* else: block_signals(0) was done before */
6685 #elif ENABLE_HUSH_INTERACTIVE
6686 /* No job control compiled in, only prompt/line editing */
6687 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6688 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6689 if (G_interactive_fd < 0) {
6690 /* try to dup to any fd */
6691 G_interactive_fd = dup(STDIN_FILENO);
6692 if (G_interactive_fd < 0)
6694 G_interactive_fd = 0;
6697 if (G_interactive_fd) {
6698 close_on_exec_on(G_interactive_fd);
6699 block_signals(signal_mask_is_inited);
6700 } else if (!signal_mask_is_inited) {
6704 /* We have interactiveness code disabled */
6705 if (!signal_mask_is_inited) {
6710 * if interactive but not a login shell, sources ~/.bashrc
6711 * (--norc turns this off, --rcfile <file> overrides)
6714 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6715 printf("\n\n%s hush - the humble shell\n", bb_banner);
6716 if (ENABLE_HUSH_HELP)
6717 puts("Enter 'help' for a list of built-in commands.");
6721 parse_and_run_file(stdin);
6724 #if ENABLE_FEATURE_CLEAN_UP
6725 if (G.cwd != bb_msg_unknown)
6727 cur_var = G.top_var->next;
6729 struct variable *tmp = cur_var;
6730 if (!cur_var->max_len)
6731 free(cur_var->varstr);
6732 cur_var = cur_var->next;
6736 hush_exit(G.last_exitcode);
6741 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6742 int lash_main(int argc, char **argv)
6744 //bb_error_msg("lash is deprecated, please use hush instead");
6745 return hush_main(argc, argv);
6753 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
6758 static int FAST_FUNC builtin_test(char **argv)
6765 return test_main(argc, argv - argc);
6768 static int FAST_FUNC builtin_echo(char **argv)
6775 return echo_main(argc, argv - argc);
6778 static int FAST_FUNC builtin_eval(char **argv)
6780 int rcode = EXIT_SUCCESS;
6783 char *str = expand_strvec_to_string(argv);
6785 * eval "echo Hi; done" ("done" is syntax error):
6786 * "echo Hi" will not execute too.
6788 parse_and_run_string(str);
6790 rcode = G.last_exitcode;
6795 static int FAST_FUNC builtin_cd(char **argv)
6797 const char *newdir = argv[1];
6798 if (newdir == NULL) {
6799 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6800 * bash says "bash: cd: HOME not set" and does nothing
6803 newdir = get_local_var_value("HOME") ? : "/";
6805 if (chdir(newdir)) {
6806 /* Mimic bash message exactly */
6807 bb_perror_msg("cd: %s", newdir);
6808 return EXIT_FAILURE;
6811 return EXIT_SUCCESS;
6814 static int FAST_FUNC builtin_exec(char **argv)
6816 if (*++argv == NULL)
6817 return EXIT_SUCCESS; /* bash does this */
6822 /* TODO: if exec fails, bash does NOT exit! We do... */
6823 pseudo_exec_argv(&dummy, argv, 0, NULL);
6828 static int FAST_FUNC builtin_exit(char **argv)
6830 debug_printf_exec("%s()\n", __func__);
6832 /* interactive bash:
6833 * # trap "echo EEE" EXIT
6836 * There are stopped jobs.
6837 * (if there are _stopped_ jobs, running ones don't count)
6840 # EEE (then bash exits)
6842 * we can use G.exiting = -1 as indicator "last cmd was exit"
6845 /* note: EXIT trap is run by hush_exit */
6846 if (*++argv == NULL)
6847 hush_exit(G.last_exitcode);
6848 /* mimic bash: exit 123abc == exit 255 + error msg */
6849 xfunc_error_retval = 255;
6850 /* bash: exit -2 == exit 254, no error msg */
6851 hush_exit(xatoi(*argv) & 0xff);
6854 static void print_escaped(const char *s)
6859 const char *p = strchrnul(s, '\'');
6860 /* print 'xxxx', possibly just '' */
6861 printf("'%.*s'", (int)(p - s), s);
6866 /* s points to '; print "'''...'''" */
6868 do putchar('\''); while (*++s == '\'');
6873 #if !ENABLE_HUSH_LOCAL
6874 #define helper_export_local(argv, exp, lvl) \
6875 helper_export_local(argv, exp)
6877 static void helper_export_local(char **argv, int exp, int lvl)
6882 /* So far we do not check that name is valid (TODO?) */
6884 if (strchr(name, '=') == NULL) {
6885 struct variable *var;
6887 var = get_local_var(name);
6888 if (exp == -1) { /* unexporting? */
6889 /* export -n NAME (without =VALUE) */
6891 var->flg_export = 0;
6892 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
6894 } /* else: export -n NOT_EXISTING_VAR: no-op */
6897 if (exp == 1) { /* exporting? */
6898 /* export NAME (without =VALUE) */
6900 var->flg_export = 1;
6901 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6902 putenv(var->varstr);
6906 /* Exporting non-existing variable.
6907 * bash does not put it in environment,
6908 * but remembers that it is exported,
6909 * and does put it in env when it is set later.
6910 * We just set it to "" and export. */
6911 /* Or, it's "local NAME" (without =VALUE).
6912 * bash sets the value to "". */
6913 name = xasprintf("%s=", name);
6915 /* (Un)exporting/making local NAME=VALUE */
6916 name = xstrdup(name);
6918 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
6922 static int FAST_FUNC builtin_export(char **argv)
6924 unsigned opt_unexport;
6926 #if ENABLE_HUSH_EXPORT_N
6927 /* "!": do not abort on errors */
6928 opt_unexport = getopt32(argv, "!n");
6929 if (opt_unexport == (uint32_t)-1)
6930 return EXIT_FAILURE;
6937 if (argv[0] == NULL) {
6944 /* ash emits: export VAR='VAL'
6945 * bash: declare -x VAR="VAL"
6946 * we follow ash example */
6947 const char *s = *e++;
6948 const char *p = strchr(s, '=');
6950 if (!p) /* wtf? take next variable */
6953 printf("export %.*s", (int)(p - s) + 1, s);
6954 print_escaped(p + 1);
6958 /*fflush(stdout); - done after each builtin anyway */
6960 return EXIT_SUCCESS;
6963 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
6965 return EXIT_SUCCESS;
6968 #if ENABLE_HUSH_LOCAL
6969 static int FAST_FUNC builtin_local(char **argv)
6971 if (G.func_nest_level == 0) {
6972 bb_error_msg("%s: not in a function", argv[0]);
6973 return EXIT_FAILURE; /* bash compat */
6975 helper_export_local(argv, 0, G.func_nest_level);
6976 return EXIT_SUCCESS;
6980 static int FAST_FUNC builtin_trap(char **argv)
6986 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6991 /* No args: print all trapped */
6992 for (i = 0; i < NSIG; ++i) {
6995 print_escaped(G.traps[i]);
6996 printf(" %s\n", get_signame(i));
6999 /*fflush(stdout); - done after each builtin anyway */
7000 return EXIT_SUCCESS;
7004 /* If first arg is a number: reset all specified signals */
7005 sig = bb_strtou(*argv, NULL, 10);
7011 sig = get_signum(*argv++);
7012 if (sig < 0 || sig >= NSIG) {
7014 /* Mimic bash message exactly */
7015 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
7020 G.traps[sig] = xstrdup(new_cmd);
7022 debug_printf("trap: setting SIG%s (%i) to '%s'",
7023 get_signame(sig), sig, G.traps[sig]);
7025 /* There is no signal for 0 (EXIT) */
7030 sigaddset(&G.blocked_set, sig);
7032 /* There was a trap handler, we are removing it
7033 * (if sig has non-DFL handling,
7034 * we don't need to do anything) */
7035 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
7037 sigdelset(&G.blocked_set, sig);
7040 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7044 if (!argv[1]) { /* no second arg */
7045 bb_error_msg("trap: invalid arguments");
7046 return EXIT_FAILURE;
7049 /* First arg is "-": reset all specified to default */
7050 /* First arg is "--": skip it, the rest is "handler SIGs..." */
7051 /* Everything else: set arg as signal handler
7052 * (includes "" case, which ignores signal) */
7053 if (argv[0][0] == '-') {
7054 if (argv[0][1] == '\0') { /* "-" */
7055 /* new_cmd remains NULL: "reset these sigs" */
7058 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
7061 /* else: "-something", no special meaning */
7066 goto process_sig_list;
7069 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
7070 static int FAST_FUNC builtin_type(char **argv)
7072 int ret = EXIT_SUCCESS;
7078 if (0) {} /* make conditional compile easier below */
7079 /*else if (find_alias(*argv))
7080 type = "an alias";*/
7081 #if ENABLE_HUSH_FUNCTIONS
7082 else if (find_function(*argv))
7083 type = "a function";
7085 else if (find_builtin(*argv))
7086 type = "a shell builtin";
7087 else if ((path = find_in_path(*argv)) != NULL)
7090 bb_error_msg("type: %s: not found", *argv);
7095 printf("%s is %s\n", *argv, type);
7103 /* built-in 'fg' and 'bg' handler */
7104 static int FAST_FUNC builtin_fg_bg(char **argv)
7109 if (!G_interactive_fd)
7110 return EXIT_FAILURE;
7112 /* If they gave us no args, assume they want the last backgrounded task */
7114 for (pi = G.job_list; pi; pi = pi->next) {
7115 if (pi->jobid == G.last_jobid) {
7119 bb_error_msg("%s: no current job", argv[0]);
7120 return EXIT_FAILURE;
7122 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
7123 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
7124 return EXIT_FAILURE;
7126 for (pi = G.job_list; pi; pi = pi->next) {
7127 if (pi->jobid == jobnum) {
7131 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
7132 return EXIT_FAILURE;
7134 /* TODO: bash prints a string representation
7135 * of job being foregrounded (like "sleep 1 | cat") */
7136 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
7137 /* Put the job into the foreground. */
7138 tcsetpgrp(G_interactive_fd, pi->pgrp);
7141 /* Restart the processes in the job */
7142 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
7143 for (i = 0; i < pi->num_cmds; i++) {
7144 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
7145 pi->cmds[i].is_stopped = 0;
7147 pi->stopped_cmds = 0;
7149 i = kill(- pi->pgrp, SIGCONT);
7151 if (errno == ESRCH) {
7152 delete_finished_bg_job(pi);
7153 return EXIT_SUCCESS;
7155 bb_perror_msg("kill (SIGCONT)");
7158 if (argv[0][0] == 'f') {
7160 return checkjobs_and_fg_shell(pi);
7162 return EXIT_SUCCESS;
7166 #if ENABLE_HUSH_HELP
7167 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
7169 const struct built_in_command *x;
7172 "Built-in commands:\n"
7173 "------------------\n");
7174 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
7176 printf("%s\t%s\n", x->cmd, x->descr);
7179 return EXIT_SUCCESS;
7184 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
7187 const char *status_string;
7189 for (job = G.job_list; job; job = job->next) {
7190 if (job->alive_cmds == job->stopped_cmds)
7191 status_string = "Stopped";
7193 status_string = "Running";
7195 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
7197 return EXIT_SUCCESS;
7202 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
7207 /* Crude attempt to find where "free memory" starts,
7208 * sans fragmentation. */
7210 l = (unsigned long)p;
7213 if (l < (unsigned long)p) l = (unsigned long)p;
7216 if (!G.memleak_value)
7217 G.memleak_value = l;
7219 l -= G.memleak_value;
7226 /* Exitcode is "how many kilobytes we leaked since 1st call" */
7231 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
7234 return EXIT_SUCCESS;
7237 static int FAST_FUNC builtin_read(char **argv)
7240 const char *name = "REPLY";
7244 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
7245 * and _after_ that_ it will complain */
7246 if (!is_well_formed_var_name(name, '\0')) {
7247 /* Mimic bash message */
7248 bb_error_msg("read: '%s': not a valid identifier", name);
7253 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
7255 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
7256 return set_local_var(string, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7259 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
7260 * built-in 'set' handler
7262 * set [-abCefhmnuvx] [-o option] [argument...]
7263 * set [+abCefhmnuvx] [+o option] [argument...]
7264 * set -- [argument...]
7267 * Implementations shall support the options in both their hyphen and
7268 * plus-sign forms. These options can also be specified as options to sh.
7270 * Write out all variables and their values: set
7271 * Set $1, $2, and $3 and set "$#" to 3: set c a b
7272 * Turn on the -x and -v options: set -xv
7273 * Unset all positional parameters: set --
7274 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
7275 * Set the positional parameters to the expansion of x, even if x expands
7276 * with a leading '-' or '+': set -- $x
7278 * So far, we only support "set -- [argument...]" and some of the short names.
7280 static int FAST_FUNC builtin_set(char **argv)
7283 char **pp, **g_argv;
7284 char *arg = *++argv;
7288 for (e = G.top_var; e; e = e->next)
7290 return EXIT_SUCCESS;
7294 if (!strcmp(arg, "--")) {
7298 if (arg[0] != '+' && arg[0] != '-')
7300 for (n = 1; arg[n]; ++n)
7301 if (set_mode(arg[0], arg[n]))
7303 } while ((arg = *++argv) != NULL);
7304 /* Now argv[0] is 1st argument */
7307 return EXIT_SUCCESS;
7310 /* NB: G.global_argv[0] ($0) is never freed/changed */
7311 g_argv = G.global_argv;
7312 if (G.global_args_malloced) {
7318 G.global_args_malloced = 1;
7319 pp = xzalloc(sizeof(pp[0]) * 2);
7320 pp[0] = g_argv[0]; /* retain $0 */
7323 /* This realloc's G.global_argv */
7324 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
7331 return EXIT_SUCCESS;
7333 /* Nothing known, so abort */
7335 bb_error_msg("set: %s: invalid option", arg);
7336 return EXIT_FAILURE;
7339 static int FAST_FUNC builtin_shift(char **argv)
7345 if (n >= 0 && n < G.global_argc) {
7346 if (G.global_args_malloced) {
7349 free(G.global_argv[m++]);
7352 memmove(&G.global_argv[1], &G.global_argv[n+1],
7353 G.global_argc * sizeof(G.global_argv[0]));
7354 return EXIT_SUCCESS;
7356 return EXIT_FAILURE;
7359 static int FAST_FUNC builtin_source(char **argv)
7364 #if ENABLE_HUSH_FUNCTIONS
7368 if (*++argv == NULL)
7369 return EXIT_FAILURE;
7371 if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
7372 input = fopen_for_read(arg_path);
7375 input = fopen_or_warn(*argv, "r");
7377 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
7378 return EXIT_FAILURE;
7380 close_on_exec_on(fileno(input));
7382 #if ENABLE_HUSH_FUNCTIONS
7383 sv_flg = G.flag_return_in_progress;
7384 /* "we are inside sourced file, ok to use return" */
7385 G.flag_return_in_progress = -1;
7387 save_and_replace_G_args(&sv, argv);
7389 parse_and_run_file(input);
7392 restore_G_args(&sv, argv);
7393 #if ENABLE_HUSH_FUNCTIONS
7394 G.flag_return_in_progress = sv_flg;
7397 return G.last_exitcode;
7400 static int FAST_FUNC builtin_umask(char **argv)
7407 mode_t old_mask = mask;
7410 rc = bb_parse_mode(argv[1], &mask);
7415 * bash: umask: 'q': invalid symbolic mode operator
7416 * bash: umask: 999: octal number out of range
7418 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
7423 printf("%04o\n", (unsigned) mask);
7424 /* fall through and restore mask which we set to 0 */
7428 return !rc; /* rc != 0 - success */
7431 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
7432 static int FAST_FUNC builtin_unset(char **argv)
7437 /* "!": do not abort on errors */
7438 /* "+": stop at 1st non-option */
7439 opts = getopt32(argv, "!+vf");
7440 if (opts == (unsigned)-1)
7441 return EXIT_FAILURE;
7443 bb_error_msg("unset: -v and -f are exclusive");
7444 return EXIT_FAILURE;
7450 if (!(opts & 2)) { /* not -f */
7451 if (unset_local_var(*argv)) {
7452 /* unset <nonexistent_var> doesn't fail.
7453 * Error is when one tries to unset RO var.
7454 * Message was printed by unset_local_var. */
7458 #if ENABLE_HUSH_FUNCTIONS
7468 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
7469 static int FAST_FUNC builtin_wait(char **argv)
7471 int ret = EXIT_SUCCESS;
7474 if (*++argv == NULL) {
7475 /* Don't care about wait results */
7476 /* Note 1: must wait until there are no more children */
7477 /* Note 2: must be interruptible */
7479 * $ sleep 3 & sleep 6 & wait
7484 * $ sleep 3 & sleep 6 & wait
7488 * ^C <-- after ~4 sec from keyboard
7491 sigaddset(&G.blocked_set, SIGCHLD);
7492 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7495 if (errno == ECHILD)
7497 /* Wait for SIGCHLD or any other signal of interest */
7498 /* sigtimedwait with infinite timeout: */
7499 sig = sigwaitinfo(&G.blocked_set, NULL);
7501 sig = check_and_run_traps(sig);
7502 if (sig && sig != SIGCHLD) { /* see note 2 */
7508 sigdelset(&G.blocked_set, SIGCHLD);
7509 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7513 /* This is probably buggy wrt interruptible-ness */
7515 pid_t pid = bb_strtou(*argv, NULL, 10);
7517 /* mimic bash message */
7518 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
7519 return EXIT_FAILURE;
7521 if (waitpid(pid, &status, 0) == pid) {
7522 if (WIFSIGNALED(status))
7523 ret = 128 + WTERMSIG(status);
7524 else if (WIFEXITED(status))
7525 ret = WEXITSTATUS(status);
7529 bb_perror_msg("wait %s", *argv);
7538 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
7539 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
7542 def = bb_strtou(argv[1], NULL, 10);
7543 if (errno || def < def_min || argv[2]) {
7544 bb_error_msg("%s: bad arguments", argv[0]);
7552 #if ENABLE_HUSH_LOOPS
7553 static int FAST_FUNC builtin_break(char **argv)
7556 if (G.depth_of_loop == 0) {
7557 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7558 return EXIT_SUCCESS; /* bash compat */
7560 G.flag_break_continue++; /* BC_BREAK = 1 */
7562 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
7563 if (depth == UINT_MAX)
7564 G.flag_break_continue = BC_BREAK;
7565 if (G.depth_of_loop < depth)
7566 G.depth_break_continue = G.depth_of_loop;
7568 return EXIT_SUCCESS;
7571 static int FAST_FUNC builtin_continue(char **argv)
7573 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
7574 return builtin_break(argv);
7578 #if ENABLE_HUSH_FUNCTIONS
7579 static int FAST_FUNC builtin_return(char **argv)
7583 if (G.flag_return_in_progress != -1) {
7584 bb_error_msg("%s: not in a function or sourced script", argv[0]);
7585 return EXIT_FAILURE; /* bash compat */
7588 G.flag_return_in_progress = 1;
7591 * out of range: wraps around at 256, does not error out
7592 * non-numeric param:
7593 * f() { false; return qwe; }; f; echo $?
7594 * bash: return: qwe: numeric argument required <== we do this
7595 * 255 <== we also do this
7597 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);