1 /* vi: set sw=4 ts=4: */
3 * sh.c -- 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>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * b_addchr() derived from similar w_addchar function in glibc-2.2
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen
26 * miscellaneous bugfixes from Matt Kraai
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * Bash grammar not implemented: (how many of these were in original sh?)
41 * ! negation operator for pipes
42 * &> and >& redirection of stdout+stderr
45 * fancy forms of Parameter Expansion
47 * Arithmetic Expansion
48 * <(list) and >(list) Process Substitution
49 * reserved words: case, esac, select, function
50 * Here Documents ( << word )
53 * job handling woefully incomplete and buggy (improved --vda)
54 * reserved word execution woefully incomplete and buggy
56 * port selected bugfixes from post-0.49 busybox lash - done?
57 * finish implementing reserved words: for, while, until, do, done
58 * change { and } from special chars to reserved words
59 * builtins: break, continue, eval, return, set, trap, ulimit
61 * handle children going into background
62 * clean up recognition of null pipes
63 * check setting of global_argc and global_argv
64 * control-C handling, probably with longjmp
65 * follow IFS rules more precisely, including update semantics
66 * figure out what to do with backslash-newline
67 * explain why we use signal instead of sigaction
68 * propagate syntax errors, die on resource errors?
69 * continuation lines, both explicit and implicit - done?
70 * memory leak finding and plugging - done?
71 * more testing, especially quoting rules and redirection
72 * document how quoting rules not precisely followed for variable assignments
73 * maybe change charmap[] to use 2-bit entries
74 * (eventually) remove all the printf's
76 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
80 #include <glob.h> /* glob, of course */
81 #include <getopt.h> /* should be pretty obvious */
82 /* #include <dmalloc.h> */
84 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
88 /* A bit drastic. Can allow some simpler commands
89 * by analysing command in generate_stream_from_list()
91 #undef ENABLE_HUSH_TICK
92 #define ENABLE_HUSH_TICK 0
96 /* If you comment out one of these below, it will be #defined later
97 * to perform debug printfs to stderr: */
98 #define debug_printf(...) do {} while (0)
99 /* Finer-grained debug switches */
100 #define debug_printf_parse(...) do {} while (0)
101 #define debug_print_tree(a, b) do {} while (0)
102 #define debug_printf_exec(...) do {} while (0)
103 #define debug_printf_jobs(...) do {} while (0)
104 #define debug_printf_expand(...) do {} while (0)
105 #define debug_printf_clean(...) do {} while (0)
108 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
111 #ifndef debug_printf_parse
112 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
115 #ifndef debug_printf_exec
116 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
119 #ifndef debug_printf_jobs
120 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
121 #define DEBUG_SHELL_JOBS 1
124 #ifndef debug_printf_expand
125 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
126 #define DEBUG_EXPAND 1
129 /* Keep unconditionally on for now */
130 #define ENABLE_HUSH_DEBUG 1
132 #ifndef debug_printf_clean
133 /* broken, of course, but OK for testing */
134 static const char *indenter(int i)
136 static const char blanks[] ALIGN1 =
138 return &blanks[sizeof(blanks) - i - 1];
140 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
141 #define DEBUG_CLEAN 1
146 * Leak hunting. Use hush_leaktool.sh for post-processing.
148 #ifdef FOR_HUSH_LEAKTOOL
149 void *xxmalloc(int lineno, size_t size)
151 void *ptr = xmalloc((size + 0xff) & ~0xff);
152 fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
155 void *xxrealloc(int lineno, void *ptr, size_t size)
157 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
158 fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
161 char *xxstrdup(int lineno, const char *str)
163 char *ptr = xstrdup(str);
164 fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
167 void xxfree(void *ptr)
169 fprintf(stderr, "free %p\n", ptr);
172 #define xmalloc(s) xxmalloc(__LINE__, s)
173 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
174 #define xstrdup(s) xxstrdup(__LINE__, s)
175 #define free(p) xxfree(p)
179 #if !ENABLE_HUSH_INTERACTIVE
180 #undef ENABLE_FEATURE_EDITING
181 #define ENABLE_FEATURE_EDITING 0
182 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
183 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
186 #define SPECIAL_VAR_SYMBOL 3
188 #define PARSEFLAG_EXIT_FROM_LOOP 1
189 #define PARSEFLAG_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
190 #define PARSEFLAG_REPARSING (1 << 2) /* >= 2nd pass */
194 REDIRECT_OVERWRITE = 2,
200 /* The descrip member of this structure is only used to make debugging
202 static const struct {
204 signed char default_fd;
208 { O_RDONLY, 0, "<" },
209 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
210 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
211 { O_RDONLY, -1, "<<" },
222 /* might eventually control execution */
232 #if ENABLE_HUSH_LOOPS
244 FLAG_END = (1 << RES_NONE ),
246 FLAG_IF = (1 << RES_IF ),
247 FLAG_THEN = (1 << RES_THEN ),
248 FLAG_ELIF = (1 << RES_ELIF ),
249 FLAG_ELSE = (1 << RES_ELSE ),
250 FLAG_FI = (1 << RES_FI ),
252 #if ENABLE_HUSH_LOOPS
253 FLAG_FOR = (1 << RES_FOR ),
254 FLAG_WHILE = (1 << RES_WHILE),
255 FLAG_UNTIL = (1 << RES_UNTIL),
256 FLAG_DO = (1 << RES_DO ),
257 FLAG_DONE = (1 << RES_DONE ),
258 FLAG_IN = (1 << RES_IN ),
260 FLAG_START = (1 << RES_XXXX ),
263 /* This holds pointers to the various results of parsing */
265 struct child_prog *child;
266 struct pipe *list_head;
268 struct redir_struct *pending_redirect;
270 smallint parse_type; /* bitmask of PARSEFLAG_xxx, defines type of parser : ";$" common or special symbol */
271 int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
272 struct p_context *stack;
273 /* How about quoting status? */
276 struct redir_struct {
277 struct redir_struct *next; /* pointer to the next redirect in the list */
278 redir_type type; /* type of redirection */
279 int fd; /* file descriptor being redirected */
280 int dup; /* -1, or file descriptor being duplicated */
281 char **glob_word; /* *word.gl_pathv is the filename */
285 pid_t pid; /* 0 if exited */
286 char **argv; /* program name and arguments */
287 struct pipe *group; /* if non-NULL, first in group or subshell */
288 smallint subshell; /* flag, non-zero if group must be forked */
289 smallint is_stopped; /* is the program currently running? */
290 struct redir_struct *redirects; /* I/O redirections */
291 struct pipe *family; /* pointer back to the child's parent pipe */
292 //sp counting seems to be broken... so commented out, grep for '//sp:'
293 //sp: int sp; /* number of SPECIAL_VAR_SYMBOL */
294 //seems to be unused, grep for '//pt:'
295 //pt: int parse_type;
297 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
298 * and on execution these are substituted with their values.
299 * Substitution can make _several_ words out of one argv[n]!
300 * Example: argv[0]=='.^C*^C.' here: echo .$*.
305 int num_progs; /* total number of programs in job */
306 int running_progs; /* number of programs running (not exited) */
307 int stopped_progs; /* number of programs alive, but stopped */
309 int jobid; /* job number */
310 pid_t pgrp; /* process group ID for the job */
311 char *cmdtext; /* name of job */
313 char *cmdbuf; /* buffer various argv's point into */
314 struct child_prog *progs; /* array of commands in pipe */
315 int job_context; /* bitmask defining current context */
316 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
317 smallint res_word; /* needed for if, for, while, until... */
320 /* On program start, environ points to initial environment.
321 * putenv adds new pointers into it, unsetenv removes them.
322 * Neither of these (de)allocates the strings.
323 * setenv allocates new strings in malloc space and does putenv,
324 * and thus setenv is unusable (leaky) for shell's purposes */
325 #define setenv(...) setenv_is_leaky_dont_use()
327 struct variable *next;
328 char *varstr; /* points to "name=" portion */
329 int max_len; /* if > 0, name is part of initial env; else name is malloced */
330 smallint flg_export; /* putenv should be done on this var */
331 smallint flg_read_only;
341 #define NULL_O_STRING {NULL,0,0,0,0}
342 /* used for initialization: o_string foo = NULL_O_STRING; */
344 /* I can almost use ordinary FILE *. Is open_memstream() universally
345 * available? Where is it documented? */
348 /* eof_flag=1: last char in ->p is really an EOF */
349 char eof_flag; /* meaningless if ->p == NULL */
351 #if ENABLE_HUSH_INTERACTIVE
353 smallint promptmode; /* 0: PS1, 1: PS2 */
356 int (*get) (struct in_str *);
357 int (*peek) (struct in_str *);
359 #define b_getch(input) ((input)->get(input))
360 #define b_peek(input) ((input)->peek(input))
364 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
365 CHAR_IFS = 2, /* treated as ordinary if quoted */
366 CHAR_SPECIAL = 3, /* example: $ */
369 #define HUSH_VER_STR "0.02"
371 /* "Globals" within this file */
373 /* Sorted roughly by size (smaller offsets == smaller code) */
375 #if ENABLE_HUSH_INTERACTIVE
376 /* 'interactive_fd' is a fd# open to ctty, if we have one
377 * _AND_ if we decided to act interactively */
382 #if ENABLE_FEATURE_EDITING
383 line_input_t *line_input_state;
387 pid_t saved_task_pgrp;
388 pid_t saved_tty_pgrp;
390 struct pipe *job_list;
391 struct pipe *toplevel_list;
392 smallint ctrl_z_flag;
395 /* these three support $?, $#, and $1 */
398 int last_return_code;
401 unsigned last_bg_pid;
402 struct variable *top_var; /* = &shell_ver (set in main()) */
403 struct variable shell_ver;
404 #if ENABLE_FEATURE_SH_STANDALONE
405 struct nofork_save_area nofork_save;
408 sigjmp_buf toplevel_jb;
410 unsigned char charmap[256];
411 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
414 #define G (*ptr_to_globals)
416 #if !ENABLE_HUSH_INTERACTIVE
417 enum { interactive_fd = 0 };
420 enum { run_list_level = 0 };
423 #if ENABLE_HUSH_INTERACTIVE
424 #define interactive_fd (G.interactive_fd )
428 #if ENABLE_FEATURE_EDITING
429 #define line_input_state (G.line_input_state)
432 #define run_list_level (G.run_list_level )
433 #define saved_task_pgrp (G.saved_task_pgrp )
434 #define saved_tty_pgrp (G.saved_tty_pgrp )
435 #define last_jobid (G.last_jobid )
436 #define job_list (G.job_list )
437 #define toplevel_list (G.toplevel_list )
438 #define toplevel_jb (G.toplevel_jb )
439 #define ctrl_z_flag (G.ctrl_z_flag )
441 #define global_argv (G.global_argv )
442 #define global_argc (G.global_argc )
443 #define last_return_code (G.last_return_code)
445 #define fake_mode (G.fake_mode )
447 #define last_bg_pid (G.last_bg_pid )
448 #define top_var (G.top_var )
449 #define shell_ver (G.shell_ver )
450 #if ENABLE_FEATURE_SH_STANDALONE
451 #define nofork_save (G.nofork_save )
454 #define toplevel_jb (G.toplevel_jb )
456 #define charmap (G.charmap )
457 #define user_input_buf (G.user_input_buf )
462 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
466 static void syntax(const char *msg)
468 /* Was using fancy stuff:
469 * (interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
470 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
471 void (*fp)(const char *s, ...);
473 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
474 fp(msg ? "%s: %s" : "syntax error", "syntax error", msg);
479 static void syntax_lineno(int line)
481 void (*fp)(const char *s, ...);
483 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
484 fp("syntax error hush.c:%d", line);
486 #define syntax(str) syntax_lineno(__LINE__)
489 /* Index of subroutines: */
490 /* o_string manipulation: */
491 static int b_check_space(o_string *o, int len);
492 static int b_addchr(o_string *o, int ch);
493 static void b_reset(o_string *o);
494 static int b_addqchr(o_string *o, int ch, int quote);
495 /* in_str manipulations: */
496 static int static_get(struct in_str *i);
497 static int static_peek(struct in_str *i);
498 static int file_get(struct in_str *i);
499 static int file_peek(struct in_str *i);
500 static void setup_file_in_str(struct in_str *i, FILE *f);
501 static void setup_string_in_str(struct in_str *i, const char *s);
502 /* "run" the final data structures: */
503 #if !defined(DEBUG_CLEAN)
504 #define free_pipe_list(head, indent) free_pipe_list(head)
505 #define free_pipe(pi, indent) free_pipe(pi)
507 static int free_pipe_list(struct pipe *head, int indent);
508 static int free_pipe(struct pipe *pi, int indent);
509 /* really run the final data structures: */
510 static int setup_redirects(struct child_prog *prog, int squirrel[]);
511 static int run_list_real(struct pipe *pi);
512 static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN;
513 static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
514 static int run_pipe_real(struct pipe *pi);
515 /* extended glob support: */
516 static char **globhack(const char *src, char **strings);
517 static int glob_needed(const char *s);
518 static int xglob(o_string *dest, char ***pglob);
519 /* variable assignment: */
520 static int is_assignment(const char *s);
521 /* data structure manipulation: */
522 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
523 static void initialize_context(struct p_context *ctx);
524 static int done_word(o_string *dest, struct p_context *ctx);
525 static int done_command(struct p_context *ctx);
526 static int done_pipe(struct p_context *ctx, pipe_style type);
527 /* primary string parsing: */
528 static int redirect_dup_num(struct in_str *input);
529 static int redirect_opt_num(o_string *o);
531 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, const char *subst_end);
533 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
534 static const char *lookup_param(const char *src);
535 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
536 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
538 static int parse_and_run_stream(struct in_str *inp, int parse_flag);
539 static int parse_and_run_string(const char *s, int parse_flag);
540 static int parse_and_run_file(FILE *f);
541 /* job management: */
542 static int checkjobs(struct pipe* fg_pipe);
544 static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
545 static void insert_bg_job(struct pipe *pi);
546 static void remove_bg_job(struct pipe *pi);
547 static void delete_finished_bg_job(struct pipe *pi);
549 int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
551 /* local variable support */
552 static char **expand_strvec_to_strvec(char **argv);
554 static char *expand_strvec_to_string(char **argv);
555 /* used for expansion of right hand of assignments */
556 static char *expand_string_to_string(const char *str);
557 static struct variable *get_local_var(const char *name);
558 static int set_local_var(char *str, int flg_export);
559 static void unset_local_var(const char *name);
562 static char **add_strings_to_strings(int need_xstrdup, char **strings, char **add)
583 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
584 v[count1 + count2] = NULL;
587 v[count1 + i] = need_xstrdup ? xstrdup(add[i]) : add[i];
591 /* 'add' should be a malloced pointer */
592 static char **add_string_to_strings(char **strings, char *add)
599 return add_strings_to_strings(0, strings, v);
602 static void free_strings(char **strings)
613 /* Function prototypes for builtins */
614 static int builtin_cd(char **argv);
615 static int builtin_echo(char **argv);
616 static int builtin_eval(char **argv);
617 static int builtin_exec(char **argv);
618 static int builtin_exit(char **argv);
619 static int builtin_export(char **argv);
621 static int builtin_fg_bg(char **argv);
622 static int builtin_jobs(char **argv);
625 static int builtin_help(char **argv);
627 static int builtin_pwd(char **argv);
628 static int builtin_read(char **argv);
629 static int builtin_test(char **argv);
630 static int builtin_set(char **argv);
631 static int builtin_shift(char **argv);
632 static int builtin_source(char **argv);
633 static int builtin_umask(char **argv);
634 static int builtin_unset(char **argv);
635 //static int builtin_not_written(char **argv);
637 /* Table of built-in functions. They can be forked or not, depending on
638 * context: within pipes, they fork. As simple commands, they do not.
639 * When used in non-forking context, they can change global variables
640 * in the parent shell process. If forked, of course they cannot.
641 * For example, 'unset foo | whatever' will parse and run, but foo will
642 * still be set at the end. */
643 struct built_in_command {
644 const char *cmd; /* name */
645 int (*function) (char **argv); /* function ptr */
647 const char *descr; /* description */
648 #define BLTIN(cmd, func, help) { cmd, func, help }
650 #define BLTIN(cmd, func, help) { cmd, func }
654 /* For now, echo and test are unconditionally enabled.
655 * Maybe make it configurable? */
656 static const struct built_in_command bltins[] = {
657 BLTIN("[" , builtin_test, "Test condition"),
658 BLTIN("[[" , builtin_test, "Test condition"),
660 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
662 // BLTIN("break" , builtin_not_written, "Exit for, while or until loop"),
663 BLTIN("cd" , builtin_cd, "Change working directory"),
664 // BLTIN("continue", builtin_not_written, "Continue for, while or until loop"),
665 BLTIN("echo" , builtin_echo, "Write strings to stdout"),
666 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
667 BLTIN("exec" , builtin_exec, "Exec command, replacing this shell with the exec'd process"),
668 BLTIN("exit" , builtin_exit, "Exit from shell"),
669 BLTIN("export", builtin_export, "Set environment variable"),
671 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
672 BLTIN("jobs" , builtin_jobs, "Lists the active jobs"),
674 // TODO: remove pwd? we have it as an applet...
675 BLTIN("pwd" , builtin_pwd, "Print current directory"),
676 BLTIN("read" , builtin_read, "Input environment variable"),
677 // BLTIN("return", builtin_not_written, "Return from a function"),
678 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
679 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
680 // BLTIN("trap" , builtin_not_written, "Trap signals"),
681 BLTIN("test" , builtin_test, "Test condition"),
682 // BLTIN("ulimit", builtin_not_written, "Controls resource limits"),
683 BLTIN("umask" , builtin_umask, "Sets file creation mask"),
684 BLTIN("unset" , builtin_unset, "Unset environment variable"),
685 BLTIN("." , builtin_source, "Source-in and run commands in a file"),
687 BLTIN("help" , builtin_help, "List shell built-in commands"),
689 BLTIN(NULL, NULL, NULL)
695 static void signal_SA_RESTART(int sig, void (*handler)(int))
698 sa.sa_handler = handler;
699 sa.sa_flags = SA_RESTART;
700 sigemptyset(&sa.sa_mask);
701 sigaction(sig, &sa, NULL);
704 /* Signals are grouped, we handle them in batches */
705 static void set_fatal_sighandler(void (*handler)(int))
707 signal(SIGILL , handler);
708 signal(SIGTRAP, handler);
709 signal(SIGABRT, handler);
710 signal(SIGFPE , handler);
711 signal(SIGBUS , handler);
712 signal(SIGSEGV, handler);
713 /* bash 3.2 seems to handle these just like 'fatal' ones */
714 signal(SIGHUP , handler);
715 signal(SIGPIPE, handler);
716 signal(SIGALRM, handler);
718 static void set_jobctrl_sighandler(void (*handler)(int))
720 signal(SIGTSTP, handler);
721 signal(SIGTTIN, handler);
722 signal(SIGTTOU, handler);
724 static void set_misc_sighandler(void (*handler)(int))
726 signal(SIGINT , handler);
727 signal(SIGQUIT, handler);
728 signal(SIGTERM, handler);
730 /* SIGCHLD is special and handled separately */
732 static void set_every_sighandler(void (*handler)(int))
734 set_fatal_sighandler(handler);
735 set_jobctrl_sighandler(handler);
736 set_misc_sighandler(handler);
737 signal(SIGCHLD, handler);
740 static void handler_ctrl_c(int sig)
742 debug_printf_jobs("got sig %d\n", sig);
743 // as usual we can have all kinds of nasty problems with leaked malloc data here
744 siglongjmp(toplevel_jb, 1);
747 static void handler_ctrl_z(int sig)
751 debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
753 if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
756 if (!pid) { /* child */
758 debug_printf_jobs("set pgrp for child %d ok\n", getpid());
759 set_every_sighandler(SIG_DFL);
760 raise(SIGTSTP); /* resend TSTP so that child will be stopped */
761 debug_printf_jobs("returning in child\n");
762 /* return to nofork, it will eventually exit now,
763 * not return back to shell */
767 /* finish filling up pipe info */
768 toplevel_list->pgrp = pid; /* child is in its own pgrp */
769 toplevel_list->progs[0].pid = pid;
770 /* parent needs to longjmp out of running nofork.
771 * we will "return" exitcode 0, with child put in background */
772 // as usual we can have all kinds of nasty problems with leaked malloc data here
773 debug_printf_jobs("siglongjmp in parent\n");
774 siglongjmp(toplevel_jb, 1);
777 /* Restores tty foreground process group, and exits.
778 * May be called as signal handler for fatal signal
779 * (will faithfully resend signal to itself, producing correct exit state)
780 * or called directly with -EXITCODE.
781 * We also call it if xfunc is exiting. */
782 static void sigexit(int sig) ATTRIBUTE_NORETURN;
783 static void sigexit(int sig)
787 /* Disable all signals: job control, SIGPIPE, etc. */
788 sigfillset(&block_all);
789 sigprocmask(SIG_SETMASK, &block_all, NULL);
792 tcsetpgrp(interactive_fd, saved_tty_pgrp);
794 /* Not a signal, just exit */
798 /* Enable only this sig and kill ourself with it */
799 signal(sig, SIG_DFL);
800 sigdelset(&block_all, sig);
801 sigprocmask(SIG_SETMASK, &block_all, NULL);
803 _exit(1); /* Should not reach it */
806 /* Restores tty foreground process group, and exits. */
807 static void hush_exit(int exitcode) ATTRIBUTE_NORETURN;
808 static void hush_exit(int exitcode)
810 fflush(NULL); /* flush all streams */
811 sigexit(- (exitcode & 0xff));
816 #define set_fatal_sighandler(handler) ((void)0)
817 #define set_jobctrl_sighandler(handler) ((void)0)
818 #define set_misc_sighandler(handler) ((void)0)
819 #define hush_exit(e) exit(e)
824 static const char *set_cwd(void)
826 if (cwd == bb_msg_unknown)
827 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
828 cwd = xrealloc_getcwd_or_warn((char *)cwd);
830 cwd = bb_msg_unknown;
835 /* built-in 'test' handler */
836 static int builtin_test(char **argv)
843 return test_main(argc, argv - argc);
846 /* built-in 'test' handler */
847 static int builtin_echo(char **argv)
854 return echo_main(argc, argv - argc);
857 /* built-in 'eval' handler */
858 static int builtin_eval(char **argv)
860 int rcode = EXIT_SUCCESS;
863 char *str = expand_strvec_to_string(argv + 1);
864 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP |
865 PARSEFLAG_SEMICOLON);
867 rcode = last_return_code;
872 /* built-in 'cd <path>' handler */
873 static int builtin_cd(char **argv)
876 if (argv[1] == NULL) {
877 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
878 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
879 newdir = getenv("HOME") ? : "/";
883 printf("cd: %s: %s\n", newdir, strerror(errno));
890 /* built-in 'exec' handler */
891 static int builtin_exec(char **argv)
894 return EXIT_SUCCESS; /* Really? */
895 pseudo_exec_argv(argv + 1);
899 /* built-in 'exit' handler */
900 static int builtin_exit(char **argv)
902 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
903 //puts("exit"); /* bash does it */
904 // TODO: warn if we have background jobs: "There are stopped jobs"
905 // On second consecutive 'exit', exit anyway.
908 hush_exit(last_return_code);
909 /* mimic bash: exit 123abc == exit 255 + error msg */
910 xfunc_error_retval = 255;
911 /* bash: exit -2 == exit 254, no error msg */
912 hush_exit(xatoi(argv[1]) & 0xff);
915 /* built-in 'export VAR=value' handler */
916 static int builtin_export(char **argv)
919 char *name = argv[1];
923 // ash emits: export VAR='VAL'
924 // bash: declare -x VAR="VAL"
925 // (both also escape as needed (quotes, $, etc))
933 value = strchr(name, '=');
935 /* They are exporting something without a =VALUE */
936 struct variable *var;
938 var = get_local_var(name);
943 /* bash does not return an error when trying to export
944 * an undefined variable. Do likewise. */
948 set_local_var(xstrdup(name), 1);
953 /* built-in 'fg' and 'bg' handler */
954 static int builtin_fg_bg(char **argv)
961 /* If they gave us no args, assume they want the last backgrounded task */
963 for (pi = job_list; pi; pi = pi->next) {
964 if (pi->jobid == last_jobid) {
968 bb_error_msg("%s: no current job", argv[0]);
971 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
972 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
975 for (pi = job_list; pi; pi = pi->next) {
976 if (pi->jobid == jobnum) {
980 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
983 // TODO: bash prints a string representation
984 // of job being foregrounded (like "sleep 1 | cat")
985 if (*argv[0] == 'f') {
986 /* Put the job into the foreground. */
987 tcsetpgrp(interactive_fd, pi->pgrp);
990 /* Restart the processes in the job */
991 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
992 for (i = 0; i < pi->num_progs; i++) {
993 debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
994 pi->progs[i].is_stopped = 0;
996 pi->stopped_progs = 0;
998 i = kill(- pi->pgrp, SIGCONT);
1000 if (errno == ESRCH) {
1001 delete_finished_bg_job(pi);
1002 return EXIT_SUCCESS;
1004 bb_perror_msg("kill (SIGCONT)");
1008 if (*argv[0] == 'f') {
1010 return checkjobs_and_fg_shell(pi);
1012 return EXIT_SUCCESS;
1016 /* built-in 'help' handler */
1017 #if ENABLE_HUSH_HELP
1018 static int builtin_help(char **argv ATTRIBUTE_UNUSED)
1020 const struct built_in_command *x;
1022 printf("\nBuilt-in commands:\n");
1023 printf("-------------------\n");
1024 for (x = bltins; x->cmd; x++) {
1025 printf("%s\t%s\n", x->cmd, x->descr);
1028 return EXIT_SUCCESS;
1033 /* built-in 'jobs' handler */
1034 static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
1037 const char *status_string;
1039 for (job = job_list; job; job = job->next) {
1040 if (job->running_progs == job->stopped_progs)
1041 status_string = "Stopped";
1043 status_string = "Running";
1045 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
1047 return EXIT_SUCCESS;
1051 /* built-in 'pwd' handler */
1052 static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
1055 return EXIT_SUCCESS;
1058 /* built-in 'read VAR' handler */
1059 static int builtin_read(char **argv)
1062 const char *name = argv[1] ? argv[1] : "REPLY";
1064 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name));
1065 return set_local_var(string, 0);
1068 /* built-in 'set [VAR=value]' handler */
1069 static int builtin_set(char **argv)
1071 char *temp = argv[1];
1075 for (e = top_var; e; e = e->next)
1078 set_local_var(xstrdup(temp), 0);
1080 return EXIT_SUCCESS;
1084 /* Built-in 'shift' handler */
1085 static int builtin_shift(char **argv)
1091 if (n >= 0 && n < global_argc) {
1092 global_argv[n] = global_argv[0];
1095 return EXIT_SUCCESS;
1097 return EXIT_FAILURE;
1100 /* Built-in '.' handler (read-in and execute commands from file) */
1101 static int builtin_source(char **argv)
1106 if (argv[1] == NULL)
1107 return EXIT_FAILURE;
1109 /* XXX search through $PATH is missing */
1110 input = fopen(argv[1], "r");
1112 bb_error_msg("cannot open '%s'", argv[1]);
1113 return EXIT_FAILURE;
1115 close_on_exec_on(fileno(input));
1117 /* Now run the file */
1118 /* XXX argv and argc are broken; need to save old global_argv
1119 * (pointer only is OK!) on this stack frame,
1120 * set global_argv=argv+1, recurse, and restore. */
1121 status = parse_and_run_file(input);
1126 static int builtin_umask(char **argv)
1129 const char *arg = argv[1];
1132 new_umask = strtoul(arg, &end, 8);
1133 if (*end != '\0' || end == arg) {
1134 return EXIT_FAILURE;
1137 new_umask = umask(0);
1138 printf("%.3o\n", (unsigned) new_umask);
1141 return EXIT_SUCCESS;
1144 /* built-in 'unset VAR' handler */
1145 static int builtin_unset(char **argv)
1147 /* bash always returns true */
1148 unset_local_var(argv[1]);
1149 return EXIT_SUCCESS;
1152 //static int builtin_not_written(char **argv)
1154 // printf("builtin_%s not written\n", argv[0]);
1155 // return EXIT_FAILURE;
1158 static int b_check_space(o_string *o, int len)
1160 /* It would be easy to drop a more restrictive policy
1161 * in here, such as setting a maximum string length */
1162 if (o->length + len > o->maxlen) {
1163 /* assert(data == NULL || o->maxlen != 0); */
1164 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1165 o->data = xrealloc(o->data, 1 + o->maxlen);
1167 return o->data == NULL;
1170 static int b_addchr(o_string *o, int ch)
1172 debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1173 if (b_check_space(o, 1))
1175 o->data[o->length] = ch;
1177 o->data[o->length] = '\0';
1181 static void b_reset(o_string *o)
1189 static void b_free(o_string *o)
1192 memset(o, 0, sizeof(*o));
1195 /* My analysis of quoting semantics tells me that state information
1196 * is associated with a destination, not a source.
1198 static int b_addqchr(o_string *o, int ch, int quote)
1200 if (quote && strchr("*?[\\", ch)) {
1202 rc = b_addchr(o, '\\');
1206 return b_addchr(o, ch);
1209 static int static_get(struct in_str *i)
1212 if (ch == '\0') return EOF;
1216 static int static_peek(struct in_str *i)
1221 #if ENABLE_HUSH_INTERACTIVE
1222 #if ENABLE_FEATURE_EDITING
1223 static void cmdedit_set_initial_prompt(void)
1225 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1228 PS1 = getenv("PS1");
1233 #endif /* EDITING */
1235 static const char* setup_prompt_string(int promptmode)
1237 const char *prompt_str;
1238 debug_printf("setup_prompt_string %d ", promptmode);
1239 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1240 /* Set up the prompt */
1241 if (promptmode == 0) { /* PS1 */
1243 PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#');
1249 prompt_str = (promptmode == 0) ? PS1 : PS2;
1251 debug_printf("result '%s'\n", prompt_str);
1255 static void get_user_input(struct in_str *i)
1258 const char *prompt_str;
1260 prompt_str = setup_prompt_string(i->promptmode);
1261 #if ENABLE_FEATURE_EDITING
1262 /* Enable command line editing only while a command line
1263 * is actually being read; otherwise, we'll end up bequeathing
1264 * atexit() handlers and other unwanted stuff to our
1265 * child processes (rob@sysgo.de) */
1266 r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state);
1267 i->eof_flag = (r < 0);
1268 if (i->eof_flag) { /* EOF/error detected */
1269 user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1270 user_input_buf[1] = '\0';
1273 fputs(prompt_str, stdout);
1275 user_input_buf[0] = r = fgetc(i->file);
1276 /*user_input_buf[1] = '\0'; - already is and never changed */
1277 i->eof_flag = (r == EOF);
1279 i->p = user_input_buf;
1281 #endif /* INTERACTIVE */
1283 /* This is the magic location that prints prompts
1284 * and gets data back from the user */
1285 static int file_get(struct in_str *i)
1289 /* If there is data waiting, eat it up */
1290 if (i->p && *i->p) {
1291 #if ENABLE_HUSH_INTERACTIVE
1295 if (i->eof_flag && !*i->p)
1298 /* need to double check i->file because we might be doing something
1299 * more complicated by now, like sourcing or substituting. */
1300 #if ENABLE_HUSH_INTERACTIVE
1301 if (interactive_fd && i->promptme && i->file == stdin) {
1304 } while (!*i->p); /* need non-empty line */
1305 i->promptmode = 1; /* PS2 */
1310 ch = fgetc(i->file);
1312 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1313 #if ENABLE_HUSH_INTERACTIVE
1320 /* All the callers guarantee this routine will never be
1321 * used right after a newline, so prompting is not needed.
1323 static int file_peek(struct in_str *i)
1326 if (i->p && *i->p) {
1327 if (i->eof_flag && !i->p[1])
1331 ch = fgetc(i->file);
1332 i->eof_flag = (ch == EOF);
1333 i->peek_buf[0] = ch;
1334 i->peek_buf[1] = '\0';
1336 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1340 static void setup_file_in_str(struct in_str *i, FILE *f)
1342 i->peek = file_peek;
1344 #if ENABLE_HUSH_INTERACTIVE
1346 i->promptmode = 0; /* PS1 */
1352 static void setup_string_in_str(struct in_str *i, const char *s)
1354 i->peek = static_peek;
1355 i->get = static_get;
1356 #if ENABLE_HUSH_INTERACTIVE
1358 i->promptmode = 0; /* PS1 */
1364 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1365 * and stderr if they are redirected. */
1366 static int setup_redirects(struct child_prog *prog, int squirrel[])
1369 struct redir_struct *redir;
1371 for (redir = prog->redirects; redir; redir = redir->next) {
1372 if (redir->dup == -1 && redir->glob_word == NULL) {
1373 /* something went wrong in the parse. Pretend it didn't happen */
1376 if (redir->dup == -1) {
1378 mode = redir_table[redir->type].mode;
1379 p = expand_string_to_string(redir->glob_word[0]);
1380 openfd = open_or_warn(p, mode);
1383 /* this could get lost if stderr has been redirected, but
1384 bash and ash both lose it as well (though zsh doesn't!) */
1388 openfd = redir->dup;
1391 if (openfd != redir->fd) {
1392 if (squirrel && redir->fd < 3) {
1393 squirrel[redir->fd] = dup(redir->fd);
1396 //close(openfd); // close(-3) ??!
1398 dup2(openfd, redir->fd);
1399 if (redir->dup == -1)
1407 static void restore_redirects(int squirrel[])
1410 for (i = 0; i < 3; i++) {
1413 /* We simply die on error */
1419 /* Called after [v]fork() in run_pipe_real(), or from builtin_exec().
1421 * XXX no exit() here. If you don't exec, use _exit instead.
1422 * The at_exit handlers apparently confuse the calling process,
1423 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
1424 static void pseudo_exec_argv(char **argv)
1428 const struct built_in_command *x;
1430 for (i = 0; is_assignment(argv[i]); i++) {
1431 debug_printf_exec("pid %d environment modification: %s\n",
1433 // FIXME: vfork case??
1434 p = expand_string_to_string(argv[i]);
1438 /* If a variable is assigned in a forest, and nobody listens,
1439 * was it ever really set?
1441 if (argv[0] == NULL) {
1442 _exit(EXIT_SUCCESS);
1445 argv = expand_strvec_to_strvec(argv);
1448 * Check if the command matches any of the builtins.
1449 * Depending on context, this might be redundant. But it's
1450 * easier to waste a few CPU cycles than it is to figure out
1451 * if this is one of those cases.
1453 for (x = bltins; x->cmd; x++) {
1454 if (strcmp(argv[0], x->cmd) == 0) {
1455 debug_printf_exec("running builtin '%s'\n", argv[0]);
1456 rcode = x->function(argv);
1462 /* Check if the command matches any busybox applets */
1463 #if ENABLE_FEATURE_SH_STANDALONE
1464 if (strchr(argv[0], '/') == NULL) {
1465 int a = find_applet_by_name(argv[0]);
1467 if (APPLET_IS_NOEXEC(a)) {
1468 debug_printf_exec("running applet '%s'\n", argv[0]);
1469 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
1470 run_applet_no_and_exit(a, argv);
1472 /* re-exec ourselves with the new arguments */
1473 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
1474 execvp(bb_busybox_exec_path, argv);
1475 /* If they called chroot or otherwise made the binary no longer
1476 * executable, fall through */
1481 debug_printf_exec("execing '%s'\n", argv[0]);
1482 execvp(argv[0], argv);
1483 bb_perror_msg("cannot exec '%s'", argv[0]);
1487 /* Called after [v]fork() in run_pipe_real()
1489 static void pseudo_exec(struct child_prog *child)
1491 // FIXME: buggy wrt NOMMU! Must not modify any global data
1492 // until it does exec/_exit, but currently it does.
1494 pseudo_exec_argv(child->argv);
1499 bb_error_msg_and_die("nested lists are not supported on NOMMU");
1503 #if ENABLE_HUSH_INTERACTIVE
1504 debug_printf_exec("pseudo_exec: setting interactive_fd=0\n");
1505 interactive_fd = 0; /* crucial!!!! */
1507 debug_printf_exec("pseudo_exec: run_list_real\n");
1508 rcode = run_list_real(child->group);
1509 /* OK to leak memory by not calling free_pipe_list,
1510 * since this process is about to exit */
1515 /* Can happen. See what bash does with ">foo" by itself. */
1516 debug_printf("trying to pseudo_exec null command\n");
1517 _exit(EXIT_SUCCESS);
1521 static const char *get_cmdtext(struct pipe *pi)
1527 /* This is subtle. ->cmdtext is created only on first backgrounding.
1528 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
1529 * On subsequent bg argv is trashed, but we won't use it */
1532 argv = pi->progs[0].argv;
1533 if (!argv || !argv[0])
1534 return (pi->cmdtext = xzalloc(1));
1537 do len += strlen(*argv) + 1; while (*++argv);
1538 pi->cmdtext = p = xmalloc(len);
1539 argv = pi->progs[0].argv;
1541 len = strlen(*argv);
1542 memcpy(p, *argv, len);
1550 static void insert_bg_job(struct pipe *pi)
1552 struct pipe *thejob;
1555 /* Linear search for the ID of the job to use */
1557 for (thejob = job_list; thejob; thejob = thejob->next)
1558 if (thejob->jobid >= pi->jobid)
1559 pi->jobid = thejob->jobid + 1;
1561 /* Add thejob to the list of running jobs */
1563 thejob = job_list = xmalloc(sizeof(*thejob));
1565 for (thejob = job_list; thejob->next; thejob = thejob->next)
1567 thejob->next = xmalloc(sizeof(*thejob));
1568 thejob = thejob->next;
1571 /* Physically copy the struct job */
1572 memcpy(thejob, pi, sizeof(struct pipe));
1573 thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs);
1574 /* We cannot copy entire pi->progs[] vector! Double free()s will happen */
1575 for (i = 0; i < pi->num_progs; i++) {
1576 // TODO: do we really need to have so many fields which are just dead weight
1577 // at execution stage?
1578 thejob->progs[i].pid = pi->progs[i].pid;
1579 /* all other fields are not used and stay zero */
1581 thejob->next = NULL;
1582 thejob->cmdtext = xstrdup(get_cmdtext(pi));
1584 /* We don't wait for background thejobs to return -- append it
1585 to the list of backgrounded thejobs and leave it alone */
1586 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
1587 last_bg_pid = thejob->progs[0].pid;
1588 last_jobid = thejob->jobid;
1591 static void remove_bg_job(struct pipe *pi)
1593 struct pipe *prev_pipe;
1595 if (pi == job_list) {
1596 job_list = pi->next;
1598 prev_pipe = job_list;
1599 while (prev_pipe->next != pi)
1600 prev_pipe = prev_pipe->next;
1601 prev_pipe->next = pi->next;
1604 last_jobid = job_list->jobid;
1609 /* remove a backgrounded job */
1610 static void delete_finished_bg_job(struct pipe *pi)
1613 pi->stopped_progs = 0;
1619 /* Checks to see if any processes have exited -- if they
1620 have, figure out why and see if a job has completed */
1621 static int checkjobs(struct pipe* fg_pipe)
1632 attributes = WUNTRACED;
1633 if (fg_pipe == NULL) {
1634 attributes |= WNOHANG;
1637 /* Do we do this right?
1638 * bash-3.00# sleep 20 | false
1640 * [3]+ Stopped sleep 20 | false
1641 * bash-3.00# echo $?
1642 * 1 <========== bg pipe is not fully done, but exitcode is already known!
1645 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
1646 //are stopped. Testcase: "cat | cat" in a script (not on command line)
1647 // + killall -STOP cat
1650 // TODO: safe_waitpid?
1651 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1652 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
1654 #ifdef DEBUG_SHELL_JOBS
1655 if (WIFSTOPPED(status))
1656 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
1657 childpid, WSTOPSIG(status), WEXITSTATUS(status));
1658 if (WIFSIGNALED(status))
1659 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
1660 childpid, WTERMSIG(status), WEXITSTATUS(status));
1661 if (WIFEXITED(status))
1662 debug_printf_jobs("pid %d exited, exitcode %d\n",
1663 childpid, WEXITSTATUS(status));
1665 /* Were we asked to wait for fg pipe? */
1668 for (i = 0; i < fg_pipe->num_progs; i++) {
1669 debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid);
1670 if (fg_pipe->progs[i].pid == childpid) {
1671 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
1673 fg_pipe->progs[i].pid = 0;
1674 fg_pipe->running_progs--;
1675 if (i == fg_pipe->num_progs-1)
1676 /* last process gives overall exitstatus */
1677 rcode = WEXITSTATUS(status);
1679 fg_pipe->progs[i].is_stopped = 1;
1680 fg_pipe->stopped_progs++;
1682 debug_printf_jobs("fg_pipe: running_progs %d stopped_progs %d\n",
1683 fg_pipe->running_progs, fg_pipe->stopped_progs);
1684 if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) {
1685 /* All processes in fg pipe have exited/stopped */
1687 if (fg_pipe->running_progs)
1688 insert_bg_job(fg_pipe);
1692 /* There are still running processes in the fg pipe */
1696 /* fall through to searching process in bg pipes */
1700 /* We asked to wait for bg or orphaned children */
1701 /* No need to remember exitcode in this case */
1702 for (pi = job_list; pi; pi = pi->next) {
1704 while (prognum < pi->num_progs) {
1705 if (pi->progs[prognum].pid == childpid)
1706 goto found_pi_and_prognum;
1712 /* Happens when shell is used as init process (init=/bin/sh) */
1713 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1717 found_pi_and_prognum:
1720 pi->progs[prognum].pid = 0;
1721 pi->running_progs--;
1722 if (!pi->running_progs) {
1723 printf(JOB_STATUS_FORMAT, pi->jobid,
1724 "Done", pi->cmdtext);
1725 delete_finished_bg_job(pi);
1729 pi->stopped_progs++;
1730 pi->progs[prognum].is_stopped = 1;
1735 /* wait found no children or failed */
1737 if (childpid && errno != ECHILD)
1738 bb_perror_msg("waitpid");
1743 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
1746 int rcode = checkjobs(fg_pipe);
1747 /* Job finished, move the shell to the foreground */
1748 p = getpgid(0); /* pgid of our process */
1749 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
1750 if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
1751 bb_perror_msg("tcsetpgrp-4a");
1756 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1757 * to finish. See checkjobs().
1759 * return code is normally -1, when the caller has to wait for children
1760 * to finish to determine the exit status of the pipe. If the pipe
1761 * is a simple builtin command, however, the action is done by the
1762 * time run_pipe_real returns, and the exit code is provided as the
1765 * The input of the pipe is always stdin, the output is always
1766 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1767 * because it tries to avoid running the command substitution in
1768 * subshell, when that is in fact necessary. The subshell process
1769 * now has its stdout directed to the input of the appropriate pipe,
1770 * so this routine is noticeably simpler.
1772 * Returns -1 only if started some children. IOW: we have to
1773 * mask out retvals of builtins etc with 0xff!
1775 static int run_pipe_real(struct pipe *pi)
1779 int pipefds[2]; /* pipefds[0] is for reading */
1780 struct child_prog *child;
1781 const struct built_in_command *x;
1783 /* it is not always needed, but we aim to smaller code */
1784 int squirrel[] = { -1, -1, -1 };
1786 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
1788 debug_printf_exec("run_pipe_real start: single_fg=%d\n", single_fg);
1793 pi->running_progs = 1;
1794 pi->stopped_progs = 0;
1796 /* Check if this is a simple builtin (not part of a pipe).
1797 * Builtins within pipes have to fork anyway, and are handled in
1798 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1800 child = &(pi->progs[0]);
1801 if (single_fg && child->group && child->subshell == 0) {
1802 debug_printf("non-subshell grouping\n");
1803 setup_redirects(child, squirrel);
1804 debug_printf_exec(": run_list_real\n");
1805 rcode = run_list_real(child->group);
1806 restore_redirects(squirrel);
1807 debug_printf_exec("run_pipe_real return %d\n", rcode);
1808 return rcode; // do we need to add '... & 0xff' ?
1811 if (single_fg && child->argv != NULL) {
1812 char **argv_expanded;
1813 char **argv = child->argv;
1815 for (i = 0; is_assignment(argv[i]); i++)
1817 if (i != 0 && argv[i] == NULL) {
1818 /* assignments, but no command: set the local environment */
1819 for (i = 0; argv[i] != NULL; i++) {
1820 debug_printf("local environment set: %s\n", argv[i]);
1821 p = expand_string_to_string(argv[i]);
1822 set_local_var(p, 0);
1824 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1826 for (i = 0; is_assignment(argv[i]); i++) {
1827 p = expand_string_to_string(argv[i]);
1831 for (x = bltins; x->cmd; x++) {
1832 if (strcmp(argv[i], x->cmd) == 0) {
1833 if (x->function == builtin_exec && argv[i+1] == NULL) {
1834 debug_printf("magic exec\n");
1835 setup_redirects(child, NULL);
1836 return EXIT_SUCCESS;
1838 debug_printf("builtin inline %s\n", argv[0]);
1839 /* XXX setup_redirects acts on file descriptors, not FILEs.
1840 * This is perfect for work that comes after exec().
1841 * Is it really safe for inline use? Experimentally,
1842 * things seem to work with glibc. */
1843 setup_redirects(child, squirrel);
1844 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
1845 //sp: if (child->sp) /* btw we can do it unconditionally... */
1846 argv_expanded = expand_strvec_to_strvec(argv + i);
1847 rcode = x->function(argv_expanded) & 0xff;
1848 free(argv_expanded);
1849 restore_redirects(squirrel);
1850 debug_printf_exec("run_pipe_real return %d\n", rcode);
1854 #if ENABLE_FEATURE_SH_STANDALONE
1856 int a = find_applet_by_name(argv[i]);
1857 if (a >= 0 && APPLET_IS_NOFORK(a)) {
1858 setup_redirects(child, squirrel);
1859 save_nofork_data(&nofork_save);
1860 argv_expanded = argv + i;
1861 //sp: if (child->sp)
1862 argv_expanded = expand_strvec_to_strvec(argv + i);
1863 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
1864 rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded) & 0xff;
1865 free(argv_expanded);
1866 restore_redirects(squirrel);
1867 debug_printf_exec("run_pipe_real return %d\n", rcode);
1874 /* Disable job control signals for shell (parent) and
1875 * for initial child code after fork */
1876 set_jobctrl_sighandler(SIG_IGN);
1878 /* Going to fork a child per each pipe member */
1879 pi->running_progs = 0;
1882 for (i = 0; i < pi->num_progs; i++) {
1883 child = &(pi->progs[i]);
1885 debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
1887 debug_printf_exec(": pipe member with no argv\n");
1889 /* pipes are inserted between pairs of commands */
1892 if ((i + 1) < pi->num_progs)
1896 child->pid = fork();
1898 child->pid = vfork();
1900 if (!child->pid) { /* child */
1902 /* Every child adds itself to new process group
1903 * with pgid == pid of first child in pipe */
1904 if (run_list_level == 1 && interactive_fd) {
1905 /* Don't do pgrp restore anymore on fatal signals */
1906 set_fatal_sighandler(SIG_DFL);
1907 if (pi->pgrp < 0) /* true for 1st process only */
1908 pi->pgrp = getpid();
1909 if (setpgid(0, pi->pgrp) == 0 && pi->followup != PIPE_BG) {
1910 /* We do it in *every* child, not just first,
1912 tcsetpgrp(interactive_fd, pi->pgrp);
1916 xmove_fd(nextin, 0);
1917 xmove_fd(pipefds[1], 1); /* write end */
1919 close(pipefds[0]); /* read end */
1920 /* Like bash, explicit redirects override pipes,
1921 * and the pipe fd is available for dup'ing. */
1922 setup_redirects(child, NULL);
1924 /* Restore default handlers just prior to exec */
1925 set_jobctrl_sighandler(SIG_DFL);
1926 set_misc_sighandler(SIG_DFL);
1927 signal(SIGCHLD, SIG_DFL);
1928 pseudo_exec(child); /* does not return */
1931 if (child->pid < 0) { /* [v]fork failed */
1932 /* Clearly indicate, was it fork or vfork */
1933 bb_perror_msg(BB_MMU ? "cannot fork" : "cannot vfork");
1935 pi->running_progs++;
1937 /* Second and next children need to know pid of first one */
1939 pi->pgrp = child->pid;
1945 if ((i + 1) < pi->num_progs)
1946 close(pipefds[1]); /* write end */
1947 /* Pass read (output) pipe end to next iteration */
1948 nextin = pipefds[0];
1951 debug_printf_exec("run_pipe_real return -1\n");
1955 #ifndef debug_print_tree
1956 static void debug_print_tree(struct pipe *pi, int lvl)
1958 static const char *PIPE[] = {
1964 static const char *RES[] = {
1965 [RES_NONE ] = "NONE" ,
1968 [RES_THEN ] = "THEN" ,
1969 [RES_ELIF ] = "ELIF" ,
1970 [RES_ELSE ] = "ELSE" ,
1973 #if ENABLE_HUSH_LOOPS
1974 [RES_FOR ] = "FOR" ,
1975 [RES_WHILE] = "WHILE",
1976 [RES_UNTIL] = "UNTIL",
1978 [RES_DONE ] = "DONE" ,
1981 [RES_XXXX ] = "XXXX" ,
1982 [RES_SNTX ] = "SNTX" ,
1989 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
1990 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
1992 while (prn < pi->num_progs) {
1993 struct child_prog *child = &pi->progs[prn];
1994 char **argv = child->argv;
1996 fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
1998 fprintf(stderr, " group %s: (argv=%p)\n",
1999 (child->subshell ? "()" : "{}"),
2001 debug_print_tree(child->group, lvl+1);
2005 if (argv) while (*argv) {
2006 fprintf(stderr, " '%s'", *argv);
2009 fprintf(stderr, "\n");
2018 /* NB: called by pseudo_exec, and therefore must not modify any
2019 * global data until exec/_exit (we can be a child after vfork!) */
2020 static int run_list_real(struct pipe *pi)
2023 #if ENABLE_HUSH_LOOPS
2024 char *for_varname = NULL;
2025 char **for_lcur = NULL;
2026 char **for_list = NULL;
2031 int rcode = 0; /* probably for gcc only */
2032 int flag_restore = 0;
2034 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
2036 enum { if_code = 0, next_if_code = 0 };
2038 reserved_style rword;
2039 reserved_style skip_more_for_this_rword = RES_XXXX;
2041 debug_printf_exec("run_list_real start lvl %d\n", run_list_level + 1);
2043 #if ENABLE_HUSH_LOOPS
2044 /* check syntax for "for" */
2045 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
2046 if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR)
2047 && (rpipe->next == NULL)
2049 syntax("malformed for"); /* no IN or no commands after IN */
2050 debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level);
2053 if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL)
2054 || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN)
2056 /* TODO: what is tested in the first condition? */
2057 syntax("malformed for"); /* 2nd condition: not followed by IN */
2058 debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level);
2067 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2068 * We are saving state before entering outermost list ("while...done")
2069 * so that ctrl-Z will correctly background _entire_ outermost list,
2070 * not just a part of it (like "sleep 1 | exit 2") */
2071 if (++run_list_level == 1 && interactive_fd) {
2072 if (sigsetjmp(toplevel_jb, 1)) {
2073 /* ctrl-Z forked and we are parent; or ctrl-C.
2074 * Sighandler has longjmped us here */
2075 signal(SIGINT, SIG_IGN);
2076 signal(SIGTSTP, SIG_IGN);
2077 /* Restore level (we can be coming from deep inside
2080 #if ENABLE_FEATURE_SH_STANDALONE
2081 if (nofork_save.saved) { /* if save area is valid */
2082 debug_printf_jobs("exiting nofork early\n");
2083 restore_nofork_data(&nofork_save);
2087 /* ctrl-Z has forked and stored pid of the child in pi->pid.
2088 * Remember this child as background job */
2091 /* ctrl-C. We just stop doing whatever we were doing */
2097 /* ctrl-Z handler will store pid etc in pi */
2100 #if ENABLE_FEATURE_SH_STANDALONE
2101 nofork_save.saved = 0; /* in case we will run a nofork later */
2103 signal_SA_RESTART(SIGTSTP, handler_ctrl_z);
2104 signal(SIGINT, handler_ctrl_c);
2108 for (; pi; pi = flag_restore ? rpipe : pi->next) {
2109 rword = pi->res_word;
2110 #if ENABLE_HUSH_LOOPS
2111 if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
2119 debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n",
2120 rword, if_code, next_if_code, skip_more_for_this_rword);
2121 if (rword == skip_more_for_this_rword && flag_skip) {
2122 if (pi->followup == PIPE_SEQ)
2127 skip_more_for_this_rword = RES_XXXX;
2129 if (rword == RES_THEN || rword == RES_ELSE)
2130 if_code = next_if_code;
2131 if (rword == RES_THEN && if_code)
2133 if (rword == RES_ELSE && !if_code)
2135 if (rword == RES_ELIF && !if_code)
2138 #if ENABLE_HUSH_LOOPS
2139 if (rword == RES_FOR && pi->num_progs) {
2141 /* first loop through for */
2142 /* if no variable values after "in" we skip "for" */
2143 if (!pi->next->progs->argv)
2145 /* create list of variable values */
2146 for_list = expand_strvec_to_strvec(pi->next->progs->argv);
2147 for_lcur = for_list;
2148 for_varname = pi->progs->argv[0];
2149 pi->progs->argv[0] = NULL;
2152 free(pi->progs->argv[0]);
2154 /* for loop is over, clean up */
2158 pi->progs->argv[0] = for_varname;
2161 /* insert next value from for_lcur */
2162 /* vda: does it need escaping? */
2163 pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
2165 if (rword == RES_IN)
2167 if (rword == RES_DO) {
2171 if (rword == RES_DONE) {
2179 if (pi->num_progs == 0)
2181 save_num_progs = pi->num_progs; /* save number of programs */
2182 debug_printf_exec(": run_pipe_real with %d members\n", pi->num_progs);
2183 rcode = run_pipe_real(pi);
2185 /* We only ran a builtin: rcode was set by the return value
2186 * of run_pipe_real(), and we don't need to wait for anything. */
2187 } else if (pi->followup == PIPE_BG) {
2188 /* What does bash do with attempts to background builtins? */
2189 /* Even bash 3.2 doesn't do that well with nested bg:
2190 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
2191 * I'm NOT treating inner &'s as jobs */
2193 if (run_list_level == 1)
2196 rcode = EXIT_SUCCESS;
2199 /* Paranoia, just "interactive_fd" should be enough? */
2200 if (run_list_level == 1 && interactive_fd) {
2201 /* waits for completion, then fg's main shell */
2202 rcode = checkjobs_and_fg_shell(pi);
2206 /* this one just waits for completion */
2207 rcode = checkjobs(pi);
2209 debug_printf_exec(": checkjobs returned %d\n", rcode);
2211 debug_printf_exec(": setting last_return_code=%d\n", rcode);
2212 last_return_code = rcode;
2213 pi->num_progs = save_num_progs; /* restore number of programs */
2215 if (rword == RES_IF || rword == RES_ELIF)
2216 next_if_code = rcode; /* can be overwritten a number of times */
2218 #if ENABLE_HUSH_LOOPS
2219 if (rword == RES_WHILE)
2220 flag_rep = !last_return_code;
2221 if (rword == RES_UNTIL)
2222 flag_rep = last_return_code;
2224 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
2225 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
2227 skip_more_for_this_rword = rword;
2234 /* ctrl-Z forked somewhere in the past, we are the child,
2235 * and now we completed running the list. Exit. */
2239 if (!--run_list_level && interactive_fd) {
2240 signal(SIGTSTP, SIG_IGN);
2241 signal(SIGINT, SIG_IGN);
2244 debug_printf_exec("run_list_real lvl %d return %d\n", run_list_level + 1, rcode);
2248 /* return code is the exit status of the pipe */
2249 static int free_pipe(struct pipe *pi, int indent)
2252 struct child_prog *child;
2253 struct redir_struct *r, *rnext;
2254 int a, i, ret_code = 0;
2256 if (pi->stopped_progs > 0)
2258 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2259 for (i = 0; i < pi->num_progs; i++) {
2260 child = &pi->progs[i];
2261 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2263 for (a = 0, p = child->argv; *p; a++, p++) {
2264 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2266 free_strings(child->argv);
2268 } else if (child->group) {
2269 debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
2270 ret_code = free_pipe_list(child->group, indent+3);
2271 debug_printf_clean("%s end group\n", indenter(indent));
2273 debug_printf_clean("%s (nil)\n", indenter(indent));
2275 for (r = child->redirects; r; r = rnext) {
2276 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
2278 /* guard against the case >$FOO, where foo is unset or blank */
2280 debug_printf_clean(" %s\n", r->glob_word[0]);
2281 free_strings(r->glob_word);
2282 r->glob_word = NULL;
2285 debug_printf_clean("&%d\n", r->dup);
2290 child->redirects = NULL;
2292 free(pi->progs); /* children are an array, they get freed all at once */
2301 static int free_pipe_list(struct pipe *head, int indent)
2303 int rcode = 0; /* if list has no members */
2304 struct pipe *pi, *next;
2306 for (pi = head; pi; pi = next) {
2307 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2308 rcode = free_pipe(pi, indent);
2309 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2311 /*pi->next = NULL;*/
2317 /* Select which version we will use */
2318 static int run_list(struct pipe *pi)
2321 debug_printf_exec("run_list entered\n");
2322 if (fake_mode == 0) {
2323 debug_printf_exec(": run_list_real with %d members\n", pi->num_progs);
2324 rcode = run_list_real(pi);
2326 /* free_pipe_list has the side effect of clearing memory.
2327 * In the long run that function can be merged with run_list_real,
2328 * but doing that now would hobble the debugging effort. */
2329 free_pipe_list(pi, 0);
2330 debug_printf_exec("run_list return %d\n", rcode);
2334 /* Whoever decided to muck with glob internal data is AN IDIOT! */
2335 /* uclibc happily changed the way it works (and it has rights to do so!),
2336 all hell broke loose (SEGVs) */
2338 /* The API for glob is arguably broken. This routine pushes a non-matching
2339 * string into the output structure, removing non-backslashed backslashes.
2340 * If someone can prove me wrong, by performing this function within the
2341 * original glob(3) api, feel free to rewrite this routine into oblivion.
2342 * XXX broken if the last character is '\\', check that before calling.
2344 static char **globhack(const char *src, char **strings)
2350 for (cnt = 1, s = src; s && *s; s++) {
2351 if (*s == '\\') s++;
2354 v = dest = xmalloc(cnt);
2355 for (s = src; s && *s; s++, dest++) {
2356 if (*s == '\\') s++;
2361 return add_string_to_strings(strings, v);
2364 /* XXX broken if the last character is '\\', check that before calling */
2365 static int glob_needed(const char *s)
2370 if (strchr("*[?", *s))
2376 static int xglob(o_string *dest, char ***pglob)
2378 /* short-circuit for null word */
2379 /* we can code this better when the debug_printf's are gone */
2380 if (dest->length == 0) {
2381 if (dest->nonnull) {
2382 /* bash man page calls this an "explicit" null */
2383 *pglob = globhack(dest->data, *pglob);
2388 if (glob_needed(dest->data)) {
2392 memset(&globdata, 0, sizeof(globdata));
2393 gr = glob(dest->data, 0, NULL, &globdata);
2394 debug_printf("glob returned %d\n", gr);
2395 if (gr == GLOB_NOSPACE)
2396 bb_error_msg_and_die("out of memory during glob");
2397 if (gr == GLOB_NOMATCH) {
2398 debug_printf("globhack returned %d\n", gr);
2399 /* quote removal, or more accurately, backslash removal */
2400 *pglob = globhack(dest->data, *pglob);
2401 globfree(&globdata);
2404 if (gr != 0) { /* GLOB_ABORTED ? */
2405 bb_error_msg("glob(3) error %d", gr);
2407 if (globdata.gl_pathv && globdata.gl_pathv[0])
2408 *pglob = add_strings_to_strings(1, *pglob, globdata.gl_pathv);
2409 globfree(&globdata);
2413 *pglob = globhack(dest->data, *pglob);
2417 /* expand_strvec_to_strvec() takes a list of strings, expands
2418 * all variable references within and returns a pointer to
2419 * a list of expanded strings, possibly with larger number
2420 * of strings. (Think VAR="a b"; echo $VAR).
2421 * This new list is allocated as a single malloc block.
2422 * NULL-terminated list of char* pointers is at the beginning of it,
2423 * followed by strings themself.
2424 * Caller can deallocate entire list by single free(list). */
2427 * count_XXX estimates size of the block we need. It's okay
2428 * to over-estimate sizes a bit, if it makes code simpler */
2429 static int count_ifs(const char *str)
2432 debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs);
2434 str += strcspn(str, ifs);
2436 str++; /* str += strspn(str, ifs); */
2437 cnt++; /* cnt += strspn(str, ifs); - but this code is larger */
2439 debug_printf_expand(" return %d\n", cnt);
2443 static void count_var_expansion_space(int *countp, int *lenp, char *arg)
2448 int count = *countp;
2452 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
2455 p = strchr(p, SPECIAL_VAR_SYMBOL);
2458 switch (first_ch & 0x7f) {
2459 /* high bit in 1st_ch indicates that var is double-quoted */
2461 case '!': /* bg pid */
2462 case '?': /* exitcode */
2463 case '#': /* argc */
2464 len += sizeof(int)*3 + 1; /* enough for int */
2468 for (i = 1; global_argv[i]; i++) {
2469 len += strlen(global_argv[i]) + 1;
2471 if (!(first_ch & 0x80))
2472 count += count_ifs(global_argv[i]);
2477 arg[0] = first_ch & 0x7f;
2478 if (isdigit(arg[0])) {
2481 if (i < global_argc)
2482 val = global_argv[i];
2484 val = lookup_param(arg);
2486 *p = SPECIAL_VAR_SYMBOL;
2489 len += strlen(val) + 1;
2490 if (!(first_ch & 0x80))
2491 count += count_ifs(val);
2497 len += strlen(arg) + 1;
2503 /* Store given string, finalizing the word and starting new one whenever
2504 * we encounter ifs char(s). This is used for expanding variable values.
2505 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2506 static int expand_on_ifs(char **list, int n, char **posp, const char *str)
2510 int word_len = strcspn(str, ifs);
2512 memcpy(pos, str, word_len); /* store non-ifs chars */
2516 if (!*str) /* EOL - do not finalize word */
2519 if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' "
2520 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2521 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2523 str += strspn(str, ifs); /* skip ifs chars */
2529 /* Expand all variable references in given string, adding words to list[]
2530 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2531 * to be filled). This routine is extremely tricky: has to deal with
2532 * variables/parameters with whitespace, $* and $@, and constructs like
2533 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2534 /* NB: another bug is that we cannot detect empty strings yet:
2535 * "" or $empty"" expands to zero words, has to expand to empty word */
2536 static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask)
2538 /* or_mask is either 0 (normal case) or 0x80
2539 * (expansion of right-hand side of assignment == 1-element expand) */
2541 char first_ch, ored_ch;
2549 if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' "
2550 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2551 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2554 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
2555 memcpy(pos, arg, p - arg);
2558 p = strchr(p, SPECIAL_VAR_SYMBOL);
2560 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2561 ored_ch |= first_ch;
2563 switch (first_ch & 0x7f) {
2564 /* Highest bit in first_ch indicates that var is double-quoted */
2566 /* FIXME: (echo $$) should still print pid of main shell */
2567 val = utoa(getpid());
2569 case '!': /* bg pid */
2570 val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
2572 case '?': /* exitcode */
2573 val = utoa(last_return_code);
2575 case '#': /* argc */
2576 val = utoa(global_argc ? global_argc-1 : 0);
2581 if (!global_argv[i])
2583 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2584 while (global_argv[i]) {
2585 n = expand_on_ifs(list, n, &pos, global_argv[i]);
2586 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
2587 if (global_argv[i++][0] && global_argv[i]) {
2588 /* this argv[] is not empty and not last:
2589 * put terminating NUL, start new word */
2591 if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' "
2592 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2593 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2598 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2599 * and in this case should treat it like '$*' - see 'else...' below */
2600 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2602 strcpy(pos, global_argv[i]);
2603 pos += strlen(global_argv[i]);
2604 if (++i >= global_argc)
2607 if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' "
2608 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2609 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2612 } else { /* quoted $*: add as one word */
2614 strcpy(pos, global_argv[i]);
2615 pos += strlen(global_argv[i]);
2616 if (!global_argv[++i])
2625 arg[0] = first_ch & 0x7f;
2626 if (isdigit(arg[0])) {
2629 if (i < global_argc)
2630 val = global_argv[i];
2632 val = lookup_param(arg);
2634 *p = SPECIAL_VAR_SYMBOL;
2635 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2637 n = expand_on_ifs(list, n, &pos, val);
2640 } /* else: quoted $VAR, val will be appended at pos */
2648 debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos);
2650 pos += strlen(arg) + 1;
2651 if (pos == list[n-1] + 1) { /* expansion is empty */
2652 if (!(ored_ch & 0x80)) { /* all vars were not quoted... */
2653 debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n);
2663 static char **expand_variables(char **argv, char or_mask)
2668 char *pos, **v, **list;
2671 if (!*v) debug_printf_expand("count_var_expansion_space: "
2672 "argv[0]=NULL count=%d len=%d alloc_space=%d\n",
2673 count, len, sizeof(char*) * count + len);
2675 count_var_expansion_space(&count, &len, *v);
2676 debug_printf_expand("count_var_expansion_space: "
2677 "'%s' count=%d len=%d alloc_space=%d\n",
2678 *v, count, len, sizeof(char*) * count + len);
2681 len += sizeof(char*) * count; /* total to alloc */
2682 list = xmalloc(len);
2683 pos = (char*)(list + count);
2684 debug_printf_expand("list=%p, list[0] should be %p\n", list, pos);
2688 n = expand_vars_to_list(list, n, &pos, *v++, or_mask);
2690 if (n) debug_printf_expand("finalized list[%d]=%p '%s' "
2691 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2692 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2699 debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]);
2702 debug_printf_expand("used_space=%d\n", pos - (char*)list);
2705 if (ENABLE_HUSH_DEBUG)
2706 if (pos - (char*)list > len)
2707 bb_error_msg_and_die("BUG in varexp");
2711 static char **expand_strvec_to_strvec(char **argv)
2713 return expand_variables(argv, 0);
2716 static char *expand_string_to_string(const char *str)
2718 char *argv[2], **list;
2720 argv[0] = (char*)str;
2722 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2723 if (ENABLE_HUSH_DEBUG)
2724 if (!list[0] || list[1])
2725 bb_error_msg_and_die("BUG in varexp2");
2726 /* actually, just move string 2*sizeof(char*) bytes back */
2727 strcpy((char*)list, list[0]);
2728 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2732 static char* expand_strvec_to_string(char **argv)
2736 list = expand_variables(argv, 0x80);
2737 /* Convert all NULs to spaces */
2741 if (ENABLE_HUSH_DEBUG)
2742 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2743 bb_error_msg_and_die("BUG in varexp3");
2744 list[n][-1] = ' '; /* TODO: or to ifs[0]? */
2748 strcpy((char*)list, list[0]);
2749 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2753 /* This is used to get/check local shell variables */
2754 static struct variable *get_local_var(const char *name)
2756 struct variable *cur;
2762 for (cur = top_var; cur; cur = cur->next) {
2763 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2769 /* str holds "NAME=VAL" and is expected to be malloced.
2770 * We take ownership of it. */
2771 static int set_local_var(char *str, int flg_export)
2773 struct variable *cur;
2777 value = strchr(str, '=');
2778 if (!value) { /* not expected to ever happen? */
2783 name_len = value - str + 1; /* including '=' */
2784 cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
2786 if (strncmp(cur->varstr, str, name_len) != 0) {
2788 /* Bail out. Note that now cur points
2789 * to last var in linked list */
2795 /* We found an existing var with this name */
2797 if (cur->flg_read_only) {
2798 bb_error_msg("%s: readonly variable", str);
2802 unsetenv(str); /* just in case */
2804 if (strcmp(cur->varstr, str) == 0) {
2809 if (cur->max_len >= strlen(str)) {
2810 /* This one is from startup env, reuse space */
2811 strcpy(cur->varstr, str);
2814 /* max_len == 0 signifies "malloced" var, which we can
2815 * (and has to) free */
2819 goto set_str_and_exp;
2822 /* Not found - create next variable struct */
2823 cur->next = xzalloc(sizeof(*cur));
2830 cur->flg_export = 1;
2831 if (cur->flg_export)
2832 return putenv(cur->varstr);
2836 static void unset_local_var(const char *name)
2838 struct variable *cur;
2839 struct variable *prev = prev; /* for gcc */
2844 name_len = strlen(name);
2847 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2848 if (cur->flg_read_only) {
2849 bb_error_msg("%s: readonly variable", name);
2852 /* prev is ok to use here because 1st variable, HUSH_VERSION,
2853 * is ro, and we cannot reach this code on the 1st pass */
2854 prev->next = cur->next;
2855 unsetenv(cur->varstr);
2866 static int is_assignment(const char *s)
2868 if (!s || !isalpha(*s))
2871 while (isalnum(*s) || *s == '_')
2876 /* the src parameter allows us to peek forward to a possible &n syntax
2877 * for file descriptor duplication, e.g., "2>&1".
2878 * Return code is 0 normally, 1 if a syntax error is detected in src.
2879 * Resource errors (in xmalloc) cause the process to exit */
2880 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2881 struct in_str *input)
2883 struct child_prog *child = ctx->child;
2884 struct redir_struct *redir = child->redirects;
2885 struct redir_struct *last_redir = NULL;
2887 /* Create a new redir_struct and drop it onto the end of the linked list */
2890 redir = redir->next;
2892 redir = xzalloc(sizeof(struct redir_struct));
2893 /* redir->next = NULL; */
2894 /* redir->glob_word = NULL; */
2896 last_redir->next = redir;
2898 child->redirects = redir;
2901 redir->type = style;
2902 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
2904 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2906 /* Check for a '2>&1' type redirect */
2907 redir->dup = redirect_dup_num(input);
2908 if (redir->dup == -2) return 1; /* syntax error */
2909 if (redir->dup != -1) {
2910 /* Erik had a check here that the file descriptor in question
2911 * is legit; I postpone that to "run time"
2912 * A "-" representation of "close me" shows up as a -3 here */
2913 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2915 /* We do _not_ try to open the file that src points to,
2916 * since we need to return and let src be expanded first.
2917 * Set ctx->pending_redirect, so we know what to do at the
2918 * end of the next parsed word. */
2919 ctx->pending_redirect = redir;
2924 static struct pipe *new_pipe(void)
2927 pi = xzalloc(sizeof(struct pipe));
2928 /*pi->num_progs = 0;*/
2929 /*pi->progs = NULL;*/
2930 /*pi->next = NULL;*/
2931 /*pi->followup = 0; invalid */
2933 pi->res_word = RES_NONE;
2937 static void initialize_context(struct p_context *ctx)
2940 ctx->pipe = ctx->list_head = new_pipe();
2941 ctx->pending_redirect = NULL;
2942 ctx->res_w = RES_NONE;
2943 //only ctx->parse_type is not touched... is this intentional?
2946 done_command(ctx); /* creates the memory for working child */
2949 /* normal return is 0
2950 * if a reserved word is found, and processed, return 1
2951 * should handle if, then, elif, else, fi, for, while, until, do, done.
2952 * case, function, and select are obnoxious, save those for later.
2954 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS
2955 static int reserved_word(o_string *dest, struct p_context *ctx)
2957 struct reserved_combo {
2962 /* Mostly a list of accepted follow-up reserved words.
2963 * FLAG_END means we are done with the sequence, and are ready
2964 * to turn the compound list into a command.
2965 * FLAG_START means the word must start a new compound list.
2967 static const struct reserved_combo reserved_list[] = {
2969 { "if", RES_IF, FLAG_THEN | FLAG_START },
2970 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2971 { "elif", RES_ELIF, FLAG_THEN },
2972 { "else", RES_ELSE, FLAG_FI },
2973 { "fi", RES_FI, FLAG_END },
2975 #if ENABLE_HUSH_LOOPS
2976 { "for", RES_FOR, FLAG_IN | FLAG_START },
2977 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2978 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2979 { "in", RES_IN, FLAG_DO },
2980 { "do", RES_DO, FLAG_DONE },
2981 { "done", RES_DONE, FLAG_END }
2985 const struct reserved_combo *r;
2987 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2988 if (strcmp(dest->data, r->literal) != 0)
2990 debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
2991 if (r->flag & FLAG_START) {
2992 struct p_context *new;
2993 debug_printf("push stack\n");
2994 #if ENABLE_HUSH_LOOPS
2995 if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) {
2996 syntax("malformed for"); /* example: 'for if' */
2997 ctx->res_w = RES_SNTX;
3002 new = xmalloc(sizeof(*new));
3003 *new = *ctx; /* physical copy */
3004 initialize_context(ctx);
3006 } else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
3008 ctx->res_w = RES_SNTX;
3012 ctx->res_w = r->code;
3013 ctx->old_flag = r->flag;
3014 if (ctx->old_flag & FLAG_END) {
3015 struct p_context *old;
3016 debug_printf("pop stack\n");
3017 done_pipe(ctx, PIPE_SEQ);
3019 old->child->group = ctx->list_head;
3020 old->child->subshell = 0;
3021 *ctx = *old; /* physical copy */
3030 #define reserved_word(dest, ctx) ((int)0)
3033 /* Normal return is 0.
3034 * Syntax or xglob errors return 1. */
3035 static int done_word(o_string *dest, struct p_context *ctx)
3037 struct child_prog *child = ctx->child;
3038 char ***glob_target;
3041 debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child);
3042 if (dest->length == 0 && !dest->nonnull) {
3043 debug_printf_parse("done_word return 0: true null, ignored\n");
3046 if (ctx->pending_redirect) {
3047 glob_target = &ctx->pending_redirect->glob_word;
3051 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3054 if (!child->argv && (ctx->parse_type & PARSEFLAG_SEMICOLON)) {
3055 debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data);
3056 if (reserved_word(dest, ctx)) {
3057 debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX));
3058 return (ctx->res_w == RES_SNTX);
3061 glob_target = &child->argv;
3063 gr = xglob(dest, glob_target);
3065 debug_printf_parse("done_word return 1: xglob returned %d\n", gr);
3070 if (ctx->pending_redirect) {
3071 /* NB: don't free_strings(ctx->pending_redirect->glob_word) here */
3072 if (ctx->pending_redirect->glob_word
3073 && ctx->pending_redirect->glob_word[0]
3074 && ctx->pending_redirect->glob_word[1]
3076 /* more than one word resulted from globbing redir */
3077 ctx->pending_redirect = NULL;
3078 bb_error_msg("ambiguous redirect");
3079 debug_printf_parse("done_word return 1: ambiguous redirect\n");
3082 ctx->pending_redirect = NULL;
3084 #if ENABLE_HUSH_LOOPS
3085 if (ctx->res_w == RES_FOR) {
3086 done_word(dest, ctx);
3087 done_pipe(ctx, PIPE_SEQ);
3090 debug_printf_parse("done_word return 0\n");
3094 /* The only possible error here is out of memory, in which case
3096 static int done_command(struct p_context *ctx)
3098 /* The child is really already in the pipe structure, so
3099 * advance the pipe counter and make a new, null child. */
3100 struct pipe *pi = ctx->pipe;
3101 struct child_prog *child = ctx->child;
3104 if (child->group == NULL
3105 && child->argv == NULL
3106 && child->redirects == NULL
3108 debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
3109 return pi->num_progs;
3112 debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
3114 debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
3117 /* Only real trickiness here is that the uncommitted
3118 * child structure is not counted in pi->num_progs. */
3119 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
3120 child = &pi->progs[pi->num_progs];
3122 memset(child, 0, sizeof(*child));
3123 /*child->redirects = NULL;*/
3124 /*child->argv = NULL;*/
3125 /*child->is_stopped = 0;*/
3126 /*child->group = NULL;*/
3128 //sp: /*child->sp = 0;*/
3129 //pt: child->parse_type = ctx->parse_type;
3132 /* but ctx->pipe and ctx->list_head remain unchanged */
3134 return pi->num_progs; /* used only for 0/nonzero check */
3137 static int done_pipe(struct p_context *ctx, pipe_style type)
3142 debug_printf_parse("done_pipe entered, followup %d\n", type);
3143 not_null = done_command(ctx); /* implicit closure of previous command */
3144 ctx->pipe->followup = type;
3145 ctx->pipe->res_word = ctx->res_w;
3146 /* Without this check, even just <enter> on command line generates
3147 * tree of three NOPs (!). Which is harmless but annoying.
3148 * IOW: it is safe to do it unconditionally. */
3151 ctx->pipe->next = new_p;
3154 done_command(ctx); /* set up new pipe to accept commands */
3156 debug_printf_parse("done_pipe return 0\n");
3160 /* peek ahead in the in_str to find out if we have a "&n" construct,
3161 * as in "2>&1", that represents duplicating a file descriptor.
3162 * returns either -2 (syntax error), -1 (no &), or the number found.
3164 static int redirect_dup_num(struct in_str *input)
3166 int ch, d = 0, ok = 0;
3168 if (ch != '&') return -1;
3170 b_getch(input); /* get the & */
3174 return -3; /* "-" represents "close me" */
3176 while (isdigit(ch)) {
3177 d = d*10 + (ch-'0');
3184 bb_error_msg("ambiguous redirect");
3188 /* If a redirect is immediately preceded by a number, that number is
3189 * supposed to tell which file descriptor to redirect. This routine
3190 * looks for such preceding numbers. In an ideal world this routine
3191 * needs to handle all the following classes of redirects...
3192 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3193 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3194 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3195 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3196 * A -1 output from this program means no valid number was found, so the
3197 * caller should use the appropriate default for this redirection.
3199 static int redirect_opt_num(o_string *o)
3205 for (num = 0; num < o->length; num++) {
3206 if (!isdigit(*(o->data + num))) {
3210 /* reuse num (and save an int) */
3211 num = atoi(o->data);
3216 #if ENABLE_HUSH_TICK
3217 /* NB: currently disabled on NOMMU */
3218 static FILE *generate_stream_from_list(struct pipe *head)
3221 int pid, channel[2];
3226 bb_perror_msg_and_die("fork");
3227 } else if (pid == 0) {
3229 if (channel[1] != 1) {
3230 dup2(channel[1], 1);
3233 /* Prevent it from trying to handle ctrl-z etc */
3237 /* Process substitution is not considered to be usual
3238 * 'command execution'.
3239 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
3240 /* Not needed, we are relying on it being disabled
3241 * everywhere outside actual command execution. */
3242 /*set_jobctrl_sighandler(SIG_IGN);*/
3243 set_misc_sighandler(SIG_DFL);
3244 _exit(run_list_real(head)); /* leaks memory */
3247 pf = fdopen(channel[0], "r");
3251 /* Return code is exit status of the process that is run. */
3252 static int process_command_subs(o_string *dest, struct p_context *ctx,
3253 struct in_str *input, const char *subst_end)
3255 int retcode, ch, eol_cnt;
3256 o_string result = NULL_O_STRING;
3257 struct p_context inner;
3259 struct in_str pipe_str;
3261 initialize_context(&inner);
3263 /* recursion to generate command */
3264 retcode = parse_stream(&result, &inner, input, subst_end);
3266 return retcode; /* syntax error or EOF */
3267 done_word(&result, &inner);
3268 done_pipe(&inner, PIPE_SEQ);
3271 p = generate_stream_from_list(inner.list_head);
3272 if (p == NULL) return 1;
3273 close_on_exec_on(fileno(p));
3274 setup_file_in_str(&pipe_str, p);
3276 /* now send results of command back into original context */
3278 while ((ch = b_getch(&pipe_str)) != EOF) {
3284 b_addqchr(dest, '\n', dest->o_quote);
3287 b_addqchr(dest, ch, dest->o_quote);
3290 debug_printf("done reading from pipe, pclose()ing\n");
3291 /* This is the step that wait()s for the child. Should be pretty
3292 * safe, since we just read an EOF from its stdout. We could try
3293 * to do better, by using wait(), and keeping track of background jobs
3294 * at the same time. That would be a lot of work, and contrary
3295 * to the KISS philosophy of this program. */
3296 retcode = fclose(p);
3297 free_pipe_list(inner.list_head, 0);
3298 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3303 static int parse_group(o_string *dest, struct p_context *ctx,
3304 struct in_str *input, int ch)
3307 const char *endch = NULL;
3308 struct p_context sub;
3309 struct child_prog *child = ctx->child;
3311 debug_printf_parse("parse_group entered\n");
3314 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3317 initialize_context(&sub);
3321 child->subshell = 1;
3323 rcode = parse_stream(dest, &sub, input, endch);
3325 done_word(dest, &sub); /* finish off the final word in the subcontext */
3326 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3327 child->group = sub.list_head;
3329 debug_printf_parse("parse_group return %d\n", rcode);
3331 /* child remains "open", available for possible redirects */
3334 /* Basically useful version until someone wants to get fancier,
3335 * see the bash man page under "Parameter Expansion" */
3336 static const char *lookup_param(const char *src)
3338 struct variable *var = get_local_var(src);
3340 return strchr(var->varstr, '=') + 1;
3344 /* return code: 0 for OK, 1 for syntax error */
3345 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
3347 int ch = b_peek(input); /* first character after the $ */
3348 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3350 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3352 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3353 //sp: ctx->child->sp++;
3355 debug_printf_parse(": '%c'\n", ch);
3357 b_addchr(dest, ch | quote_mask);
3360 if (!isalnum(ch) && ch != '_')
3363 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3364 } else if (isdigit(ch)) {
3366 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3367 //sp: ctx->child->sp++;
3368 debug_printf_parse(": '%c'\n", ch);
3370 b_addchr(dest, ch | quote_mask);
3371 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3372 } else switch (ch) {
3374 case '!': /* last bg pid */
3375 case '?': /* last exit code */
3376 case '#': /* number of args */
3377 case '*': /* args */
3378 case '@': /* args */
3379 goto make_one_char_var;
3381 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3382 //sp: ctx->child->sp++;
3384 /* XXX maybe someone will try to escape the '}' */
3386 ch = b_getch(input);
3389 if (!isalnum(ch) && ch != '_') {
3390 syntax("unterminated ${name}");
3391 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3394 debug_printf_parse(": '%c'\n", ch);
3395 b_addchr(dest, ch | quote_mask);
3398 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3400 #if ENABLE_HUSH_TICK
3403 process_command_subs(dest, ctx, input, ")");
3408 /* still unhandled, but should be eventually */
3409 bb_error_msg("unhandled syntax: $%c", ch);
3413 b_addqchr(dest, '$', dest->o_quote);
3415 debug_printf_parse("handle_dollar return 0\n");
3419 /* return code is 0 for normal exit, 1 for syntax error */
3420 static int parse_stream(o_string *dest, struct p_context *ctx,
3421 struct in_str *input, const char *end_trigger)
3425 redir_type redir_style;
3428 /* Only double-quote state is handled in the state variable dest->o_quote.
3429 * A single-quote triggers a bypass of the main loop until its mate is
3430 * found. When recursing, quote state is passed in via dest->o_quote. */
3432 debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
3437 ch = b_getch(input);
3441 next = b_peek(input);
3443 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
3444 ch, ch, m, dest->o_quote);
3445 if (m == CHAR_ORDINARY
3446 || (m != CHAR_SPECIAL && dest->o_quote)
3449 syntax("unterminated \"");
3450 debug_printf_parse("parse_stream return 1: unterminated \"\n");
3453 b_addqchr(dest, ch, dest->o_quote);
3456 if (m == CHAR_IFS) {
3457 if (done_word(dest, ctx)) {
3458 debug_printf_parse("parse_stream return 1: done_word!=0\n");
3463 /* If we aren't performing a substitution, treat
3464 * a newline as a command separator.
3465 * [why we don't handle it exactly like ';'? --vda] */
3466 if (end_trigger && ch == '\n') {
3467 done_pipe(ctx, PIPE_SEQ);
3470 if ((end_trigger && strchr(end_trigger, ch))
3471 && !dest->o_quote && ctx->res_w == RES_NONE
3473 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
3480 if (dest->length == 0 && !dest->o_quote) {
3483 if (ch == EOF || ch == '\n')
3488 b_addqchr(dest, ch, dest->o_quote);
3494 debug_printf_parse("parse_stream return 1: \\<eof>\n");
3497 b_addqchr(dest, '\\', dest->o_quote);
3498 b_addqchr(dest, b_getch(input), dest->o_quote);
3501 if (handle_dollar(dest, ctx, input) != 0) {
3502 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
3509 ch = b_getch(input);
3510 if (ch == EOF || ch == '\'')
3515 syntax("unterminated '");
3516 debug_printf_parse("parse_stream return 1: unterminated '\n");
3522 dest->o_quote ^= 1; /* invert */
3524 #if ENABLE_HUSH_TICK
3526 process_command_subs(dest, ctx, input, "`");
3530 redir_fd = redirect_opt_num(dest);
3531 done_word(dest, ctx);
3532 redir_style = REDIRECT_OVERWRITE;
3534 redir_style = REDIRECT_APPEND;
3538 else if (next == '(') {
3539 syntax(">(process) not supported");
3540 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
3544 setup_redirect(ctx, redir_fd, redir_style, input);
3547 redir_fd = redirect_opt_num(dest);
3548 done_word(dest, ctx);
3549 redir_style = REDIRECT_INPUT;
3551 redir_style = REDIRECT_HEREIS;
3553 } else if (next == '>') {
3554 redir_style = REDIRECT_IO;
3558 else if (next == '(') {
3559 syntax("<(process) not supported");
3560 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
3564 setup_redirect(ctx, redir_fd, redir_style, input);
3567 done_word(dest, ctx);
3568 done_pipe(ctx, PIPE_SEQ);
3571 done_word(dest, ctx);
3574 done_pipe(ctx, PIPE_AND);
3576 done_pipe(ctx, PIPE_BG);
3580 done_word(dest, ctx);
3583 done_pipe(ctx, PIPE_OR);
3585 /* we could pick up a file descriptor choice here
3586 * with redirect_opt_num(), but bash doesn't do it.
3587 * "echo foo 2| cat" yields "foo 2". */
3593 if (parse_group(dest, ctx, input, ch) != 0) {
3594 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
3600 syntax("unexpected }"); /* Proper use of this character is caught by end_trigger */
3601 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
3604 if (ENABLE_HUSH_DEBUG)
3605 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
3608 /* Complain if quote? No, maybe we just finished a command substitution
3609 * that was quoted. Example:
3610 * $ echo "`cat foo` plus more"
3611 * and we just got the EOF generated by the subshell that ran "cat foo"
3612 * The only real complaint is if we got an EOF when end_trigger != NULL,
3613 * that is, we were really supposed to get end_trigger, and never got
3614 * one before the EOF. Can't use the standard "syntax error" return code,
3615 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3616 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
3622 static void set_in_charmap(const char *set, int code)
3625 charmap[(unsigned char)*set++] = code;
3628 static void update_charmap(void)
3630 /* char *ifs and char charmap[256] are both globals. */
3631 ifs = getenv("IFS");
3634 /* Precompute a list of 'flow through' behavior so it can be treated
3635 * quickly up front. Computation is necessary because of IFS.
3636 * Special case handling of IFS == " \t\n" is not implemented.
3637 * The charmap[] array only really needs two bits each,
3638 * and on most machines that would be faster (reduced L1 cache use).
3640 memset(charmap, CHAR_ORDINARY, sizeof(charmap));
3641 #if ENABLE_HUSH_TICK
3642 set_in_charmap("\\$\"`", CHAR_SPECIAL);
3644 set_in_charmap("\\$\"", CHAR_SPECIAL);
3646 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
3647 set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */
3650 /* most recursion does not come through here, the exception is
3651 * from builtin_source() and builtin_eval() */
3652 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
3654 struct p_context ctx;
3655 o_string temp = NULL_O_STRING;
3658 ctx.parse_type = parse_flag;
3659 initialize_context(&ctx);
3661 if (!(parse_flag & PARSEFLAG_SEMICOLON) || (parse_flag & PARSEFLAG_REPARSING))
3662 set_in_charmap(";$&|", CHAR_ORDINARY);
3663 #if ENABLE_HUSH_INTERACTIVE
3664 inp->promptmode = 0; /* PS1 */
3666 /* We will stop & execute after each ';' or '\n'.
3667 * Example: "sleep 9999; echo TEST" + ctrl-C:
3668 * TEST should be printed */
3669 rcode = parse_stream(&temp, &ctx, inp, ";\n");
3670 if (rcode != 1 && ctx.old_flag != 0) {
3673 if (rcode != 1 && ctx.old_flag == 0) {
3674 done_word(&temp, &ctx);
3675 done_pipe(&ctx, PIPE_SEQ);
3676 debug_print_tree(ctx.list_head, 0);
3677 debug_printf_exec("parse_stream_outer: run_list\n");
3678 run_list(ctx.list_head);
3680 if (ctx.old_flag != 0) {
3687 free_pipe_list(ctx.list_head, 0);
3690 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
3694 static int parse_and_run_string(const char *s, int parse_flag)
3696 struct in_str input;
3697 setup_string_in_str(&input, s);
3698 return parse_and_run_stream(&input, parse_flag);
3701 static int parse_and_run_file(FILE *f)
3704 struct in_str input;
3705 setup_file_in_str(&input, f);
3706 rcode = parse_and_run_stream(&input, PARSEFLAG_SEMICOLON);
3711 /* Make sure we have a controlling tty. If we get started under a job
3712 * aware app (like bash for example), make sure we are now in charge so
3713 * we don't fight over who gets the foreground */
3714 static void setup_job_control(void)
3718 saved_task_pgrp = shell_pgrp = getpgrp();
3719 debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
3720 close_on_exec_on(interactive_fd);
3722 /* If we were ran as 'hush &',
3723 * sleep until we are in the foreground. */
3724 while (tcgetpgrp(interactive_fd) != shell_pgrp) {
3725 /* Send TTIN to ourself (should stop us) */
3726 kill(- shell_pgrp, SIGTTIN);
3727 shell_pgrp = getpgrp();
3730 /* Ignore job-control and misc signals. */
3731 set_jobctrl_sighandler(SIG_IGN);
3732 set_misc_sighandler(SIG_IGN);
3733 //huh? signal(SIGCHLD, SIG_IGN);
3735 /* We _must_ restore tty pgrp on fatal signals */
3736 set_fatal_sighandler(sigexit);
3738 /* Put ourselves in our own process group. */
3739 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
3740 /* Grab control of the terminal. */
3741 tcsetpgrp(interactive_fd, getpid());
3745 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3746 int hush_main(int argc, char **argv)
3748 static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
3749 static const struct variable const_shell_ver = {
3751 .varstr = (char*)version_str,
3752 .max_len = 1, /* 0 can provoke free(name) */
3760 struct variable *cur_var;
3762 PTR_TO_GLOBALS = xzalloc(sizeof(G));
3764 /* Deal with HUSH_VERSION */
3765 shell_ver = const_shell_ver; /* copying struct here */
3766 top_var = &shell_ver;
3767 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
3768 /* Initialize our shell local variables with the values
3769 * currently living in the environment */
3773 char *value = strchr(*e, '=');
3774 if (value) { /* paranoia */
3775 cur_var->next = xzalloc(sizeof(*cur_var));
3776 cur_var = cur_var->next;
3777 cur_var->varstr = *e;
3778 cur_var->max_len = strlen(*e);
3779 cur_var->flg_export = 1;
3783 putenv((char *)version_str); /* reinstate HUSH_VERSION */
3785 #if ENABLE_FEATURE_EDITING
3786 line_input_state = new_line_input_t(FOR_SHELL);
3788 /* XXX what should these be while sourcing /etc/profile? */
3791 /* Initialize some more globals to non-zero values */
3793 #if ENABLE_HUSH_INTERACTIVE
3794 #if ENABLE_FEATURE_EDITING
3795 cmdedit_set_initial_prompt();
3800 if (EXIT_SUCCESS) /* otherwise is already done */
3801 last_return_code = EXIT_SUCCESS;
3803 if (argv[0] && argv[0][0] == '-') {
3804 debug_printf("sourcing /etc/profile\n");
3805 input = fopen("/etc/profile", "r");
3806 if (input != NULL) {
3807 close_on_exec_on(fileno(input));
3808 parse_and_run_file(input);
3814 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3817 global_argv = argv + optind;
3818 global_argc = argc - optind;
3819 opt = parse_and_run_string(optarg, PARSEFLAG_SEMICOLON);
3822 /* Well, we cannot just declare interactiveness,
3823 * we have to have some stuff (ctty, etc) */
3824 /* interactive_fd++; */
3831 fprintf(stderr, "Usage: sh [FILE]...\n"
3832 " or: sh -c command [args]...\n\n");
3840 /* A shell is interactive if the '-i' flag was given, or if all of
3841 * the following conditions are met:
3843 * no arguments remaining or the -s flag given
3844 * standard input is a terminal
3845 * standard output is a terminal
3846 * Refer to Posix.2, the description of the 'sh' utility. */
3847 if (argv[optind] == NULL && input == stdin
3848 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3850 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
3851 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
3852 if (saved_tty_pgrp >= 0) {
3853 /* try to dup to high fd#, >= 255 */
3854 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3855 if (interactive_fd < 0) {
3856 /* try to dup to any fd */
3857 interactive_fd = dup(STDIN_FILENO);
3858 if (interactive_fd < 0)
3862 // TODO: track & disallow any attempts of user
3863 // to (inadvertently) close/redirect it
3866 debug_printf("interactive_fd=%d\n", interactive_fd);
3867 if (interactive_fd) {
3868 /* Looks like they want an interactive shell */
3869 setup_job_control();
3870 /* Make xfuncs do cleanup on exit */
3871 die_sleep = -1; /* flag */
3872 // FIXME: should we reset die_sleep = 0 whereever we fork?
3873 if (setjmp(die_jmp)) {
3874 /* xfunc has failed! die die die */
3875 hush_exit(xfunc_error_retval);
3877 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
3878 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
3879 printf("Enter 'help' for a list of built-in commands.\n\n");
3882 #elif ENABLE_HUSH_INTERACTIVE
3883 /* no job control compiled, only prompt/line editing */
3884 if (argv[optind] == NULL && input == stdin
3885 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3887 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3888 if (interactive_fd < 0) {
3889 /* try to dup to any fd */
3890 interactive_fd = dup(STDIN_FILENO);
3891 if (interactive_fd < 0)
3899 if (argv[optind] == NULL) {
3900 opt = parse_and_run_file(stdin);
3904 debug_printf("\nrunning script '%s'\n", argv[optind]);
3905 global_argv = argv + optind;
3906 global_argc = argc - optind;
3907 input = xfopen(argv[optind], "r");
3908 opt = parse_and_run_file(input);
3912 #if ENABLE_FEATURE_CLEAN_UP
3914 if (cwd != bb_msg_unknown)
3916 cur_var = top_var->next;
3918 struct variable *tmp = cur_var;
3919 if (!cur_var->max_len)
3920 free(cur_var->varstr);
3921 cur_var = cur_var->next;
3925 hush_exit(opt ? opt : last_return_code);
3930 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3931 int lash_main(int argc, char **argv)
3933 //bb_error_msg("lash is deprecated, please use hush instead");
3934 return hush_main(argc, argv);