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 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
86 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
90 /* A bit drastic. Can allow some simpler commands
91 * by analysing command in generate_stream_from_list()
93 #undef ENABLE_HUSH_TICK
94 #define ENABLE_HUSH_TICK 0
98 /* If you comment out one of these below, it will be #defined later
99 * to perform debug printfs to stderr: */
100 #define debug_printf(...) do {} while (0)
101 /* Finer-grained debug switches */
102 #define debug_printf_parse(...) do {} while (0)
103 #define debug_print_tree(a, b) do {} while (0)
104 #define debug_printf_exec(...) do {} while (0)
105 #define debug_printf_jobs(...) do {} while (0)
106 #define debug_printf_expand(...) do {} while (0)
107 #define debug_printf_clean(...) do {} while (0)
110 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
113 #ifndef debug_printf_parse
114 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
117 #ifndef debug_printf_exec
118 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
121 #ifndef debug_printf_jobs
122 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
123 #define DEBUG_SHELL_JOBS 1
126 #ifndef debug_printf_expand
127 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
128 #define DEBUG_EXPAND 1
131 /* Keep unconditionally on for now */
132 #define ENABLE_HUSH_DEBUG 1
134 #ifndef debug_printf_clean
135 /* broken, of course, but OK for testing */
136 static const char *indenter(int i)
138 static const char blanks[] ALIGN1 =
140 return &blanks[sizeof(blanks) - i - 1];
142 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
143 #define DEBUG_CLEAN 1
148 * Leak hunting. Use hush_leaktool.sh for post-processing.
150 #ifdef FOR_HUSH_LEAKTOOL
151 void *xxmalloc(int lineno, size_t size)
153 void *ptr = xmalloc((size + 0xff) & ~0xff);
154 fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
157 void *xxrealloc(int lineno, void *ptr, size_t size)
159 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
160 fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
163 char *xxstrdup(int lineno, const char *str)
165 char *ptr = xstrdup(str);
166 fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
169 void xxfree(void *ptr)
171 fprintf(stderr, "free %p\n", ptr);
174 #define xmalloc(s) xxmalloc(__LINE__, s)
175 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
176 #define xstrdup(s) xxstrdup(__LINE__, s)
177 #define free(p) xxfree(p)
181 #if !ENABLE_HUSH_INTERACTIVE
182 #undef ENABLE_FEATURE_EDITING
183 #define ENABLE_FEATURE_EDITING 0
184 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
185 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
188 #define SPECIAL_VAR_SYMBOL 3
190 #define PARSEFLAG_EXIT_FROM_LOOP 1
191 #define PARSEFLAG_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
192 #define PARSEFLAG_REPARSING (1 << 2) /* >= 2nd pass */
196 REDIRECT_OVERWRITE = 2,
202 /* The descrip member of this structure is only used to make debugging
204 static const struct {
206 signed char default_fd;
210 { O_RDONLY, 0, "<" },
211 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
212 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
213 { O_RDONLY, -1, "<<" },
224 /* might eventually control execution */
234 #if ENABLE_HUSH_LOOPS
246 FLAG_END = (1 << RES_NONE ),
248 FLAG_IF = (1 << RES_IF ),
249 FLAG_THEN = (1 << RES_THEN ),
250 FLAG_ELIF = (1 << RES_ELIF ),
251 FLAG_ELSE = (1 << RES_ELSE ),
252 FLAG_FI = (1 << RES_FI ),
254 #if ENABLE_HUSH_LOOPS
255 FLAG_FOR = (1 << RES_FOR ),
256 FLAG_WHILE = (1 << RES_WHILE),
257 FLAG_UNTIL = (1 << RES_UNTIL),
258 FLAG_DO = (1 << RES_DO ),
259 FLAG_DONE = (1 << RES_DONE ),
260 FLAG_IN = (1 << RES_IN ),
262 FLAG_START = (1 << RES_XXXX ),
265 /* This holds pointers to the various results of parsing */
267 struct child_prog *child;
268 struct pipe *list_head;
270 struct redir_struct *pending_redirect;
272 smallint parse_type; /* bitmask of PARSEFLAG_xxx, defines type of parser : ";$" common or special symbol */
273 int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
274 struct p_context *stack;
275 /* How about quoting status? */
278 struct redir_struct {
279 struct redir_struct *next; /* pointer to the next redirect in the list */
280 redir_type type; /* type of redirection */
281 int fd; /* file descriptor being redirected */
282 int dup; /* -1, or file descriptor being duplicated */
283 char **glob_word; /* *word.gl_pathv is the filename */
287 pid_t pid; /* 0 if exited */
288 char **argv; /* program name and arguments */
289 struct pipe *group; /* if non-NULL, first in group or subshell */
290 smallint subshell; /* flag, non-zero if group must be forked */
291 smallint is_stopped; /* is the program currently running? */
292 struct redir_struct *redirects; /* I/O redirections */
293 struct pipe *family; /* pointer back to the child's parent pipe */
294 //sp counting seems to be broken... so commented out, grep for '//sp:'
295 //sp: int sp; /* number of SPECIAL_VAR_SYMBOL */
296 //seems to be unused, grep for '//pt:'
297 //pt: int parse_type;
299 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
300 * and on execution these are substituted with their values.
301 * Substitution can make _several_ words out of one argv[n]!
302 * Example: argv[0]=='.^C*^C.' here: echo .$*.
307 int num_progs; /* total number of programs in job */
308 int running_progs; /* number of programs running (not exited) */
309 int stopped_progs; /* number of programs alive, but stopped */
311 int jobid; /* job number */
312 pid_t pgrp; /* process group ID for the job */
313 char *cmdtext; /* name of job */
315 char *cmdbuf; /* buffer various argv's point into */
316 struct child_prog *progs; /* array of commands in pipe */
317 int job_context; /* bitmask defining current context */
318 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
319 smallint res_word; /* needed for if, for, while, until... */
322 /* On program start, environ points to initial environment.
323 * putenv adds new pointers into it, unsetenv removes them.
324 * Neither of these (de)allocates the strings.
325 * setenv allocates new strings in malloc space and does putenv,
326 * and thus setenv is unusable (leaky) for shell's purposes */
327 #define setenv(...) setenv_is_leaky_dont_use()
329 struct variable *next;
330 char *varstr; /* points to "name=" portion */
331 int max_len; /* if > 0, name is part of initial env; else name is malloced */
332 smallint flg_export; /* putenv should be done on this var */
333 smallint flg_read_only;
343 #define NULL_O_STRING {NULL,0,0,0,0}
344 /* used for initialization: o_string foo = NULL_O_STRING; */
346 /* I can almost use ordinary FILE *. Is open_memstream() universally
347 * available? Where is it documented? */
350 /* eof_flag=1: last char in ->p is really an EOF */
351 char eof_flag; /* meaningless if ->p == NULL */
353 #if ENABLE_HUSH_INTERACTIVE
355 smallint promptmode; /* 0: PS1, 1: PS2 */
358 int (*get) (struct in_str *);
359 int (*peek) (struct in_str *);
361 #define b_getch(input) ((input)->get(input))
362 #define b_peek(input) ((input)->peek(input))
366 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
367 CHAR_IFS = 2, /* treated as ordinary if quoted */
368 CHAR_SPECIAL = 3, /* example: $ */
371 #define HUSH_VER_STR "0.02"
373 /* "Globals" within this file */
375 /* Sorted roughly by size (smaller offsets == smaller code) */
377 #if ENABLE_HUSH_INTERACTIVE
378 /* 'interactive_fd' is a fd# open to ctty, if we have one
379 * _AND_ if we decided to act interactively */
384 #if ENABLE_FEATURE_EDITING
385 line_input_t *line_input_state;
389 pid_t saved_task_pgrp;
390 pid_t saved_tty_pgrp;
392 struct pipe *job_list;
393 struct pipe *toplevel_list;
394 smallint ctrl_z_flag;
397 /* these three support $?, $#, and $1 */
400 int last_return_code;
403 unsigned last_bg_pid;
404 struct variable *top_var; /* = &shell_ver (set in main()) */
405 struct variable shell_ver;
406 #if ENABLE_FEATURE_SH_STANDALONE
407 struct nofork_save_area nofork_save;
410 sigjmp_buf toplevel_jb;
412 unsigned char charmap[256];
413 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
416 #define G (*ptr_to_globals)
418 #if !ENABLE_HUSH_INTERACTIVE
419 enum { interactive_fd = 0 };
422 enum { run_list_level = 0 };
425 #if ENABLE_HUSH_INTERACTIVE
426 #define interactive_fd (G.interactive_fd )
430 #if ENABLE_FEATURE_EDITING
431 #define line_input_state (G.line_input_state)
434 #define run_list_level (G.run_list_level )
435 #define saved_task_pgrp (G.saved_task_pgrp )
436 #define saved_tty_pgrp (G.saved_tty_pgrp )
437 #define last_jobid (G.last_jobid )
438 #define job_list (G.job_list )
439 #define toplevel_list (G.toplevel_list )
440 #define toplevel_jb (G.toplevel_jb )
441 #define ctrl_z_flag (G.ctrl_z_flag )
443 #define global_argv (G.global_argv )
444 #define global_argc (G.global_argc )
445 #define last_return_code (G.last_return_code)
447 #define fake_mode (G.fake_mode )
449 #define last_bg_pid (G.last_bg_pid )
450 #define top_var (G.top_var )
451 #define shell_ver (G.shell_ver )
452 #if ENABLE_FEATURE_SH_STANDALONE
453 #define nofork_save (G.nofork_save )
456 #define toplevel_jb (G.toplevel_jb )
458 #define charmap (G.charmap )
459 #define user_input_buf (G.user_input_buf )
464 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
468 static void syntax(const char *msg)
470 /* Was using fancy stuff:
471 * (interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
472 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
473 void (*fp)(const char *s, ...);
475 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
476 fp(msg ? "%s: %s" : "syntax error", "syntax error", msg);
481 static void syntax_lineno(int line)
483 void (*fp)(const char *s, ...);
485 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
486 fp("syntax error hush.c:%d", line);
488 #define syntax(str) syntax_lineno(__LINE__)
491 /* Index of subroutines: */
492 /* o_string manipulation: */
493 static int b_check_space(o_string *o, int len);
494 static int b_addchr(o_string *o, int ch);
495 static void b_reset(o_string *o);
496 static int b_addqchr(o_string *o, int ch, int quote);
497 /* in_str manipulations: */
498 static int static_get(struct in_str *i);
499 static int static_peek(struct in_str *i);
500 static int file_get(struct in_str *i);
501 static int file_peek(struct in_str *i);
502 static void setup_file_in_str(struct in_str *i, FILE *f);
503 static void setup_string_in_str(struct in_str *i, const char *s);
504 /* "run" the final data structures: */
505 #if !defined(DEBUG_CLEAN)
506 #define free_pipe_list(head, indent) free_pipe_list(head)
507 #define free_pipe(pi, indent) free_pipe(pi)
509 static int free_pipe_list(struct pipe *head, int indent);
510 static int free_pipe(struct pipe *pi, int indent);
511 /* really run the final data structures: */
512 static int setup_redirects(struct child_prog *prog, int squirrel[]);
513 static int run_list_real(struct pipe *pi);
514 static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN;
515 static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
516 static int run_pipe_real(struct pipe *pi);
517 /* extended glob support: */
518 static char **globhack(const char *src, char **strings);
519 static int glob_needed(const char *s);
520 static int xglob(o_string *dest, char ***pglob);
521 /* variable assignment: */
522 static int is_assignment(const char *s);
523 /* data structure manipulation: */
524 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
525 static void initialize_context(struct p_context *ctx);
526 static int done_word(o_string *dest, struct p_context *ctx);
527 static int done_command(struct p_context *ctx);
528 static int done_pipe(struct p_context *ctx, pipe_style type);
529 /* primary string parsing: */
530 static int redirect_dup_num(struct in_str *input);
531 static int redirect_opt_num(o_string *o);
533 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, const char *subst_end);
535 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
536 static const char *lookup_param(const char *src);
537 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
538 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
540 static int parse_and_run_stream(struct in_str *inp, int parse_flag);
541 static int parse_and_run_string(const char *s, int parse_flag);
542 static int parse_and_run_file(FILE *f);
543 /* job management: */
544 static int checkjobs(struct pipe* fg_pipe);
546 static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
547 static void insert_bg_job(struct pipe *pi);
548 static void remove_bg_job(struct pipe *pi);
549 static void delete_finished_bg_job(struct pipe *pi);
551 int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
553 /* local variable support */
554 static char **expand_strvec_to_strvec(char **argv);
556 static char *expand_strvec_to_string(char **argv);
557 /* used for expansion of right hand of assignments */
558 static char *expand_string_to_string(const char *str);
559 static struct variable *get_local_var(const char *name);
560 static int set_local_var(char *str, int flg_export);
561 static void unset_local_var(const char *name);
564 static char **add_strings_to_strings(int need_xstrdup, char **strings, char **add)
585 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
586 v[count1 + count2] = NULL;
589 v[count1 + i] = need_xstrdup ? xstrdup(add[i]) : add[i];
593 /* 'add' should be a malloced pointer */
594 static char **add_string_to_strings(char **strings, char *add)
601 return add_strings_to_strings(0, strings, v);
604 static void free_strings(char **strings)
615 /* Function prototypes for builtins */
616 static int builtin_cd(char **argv);
617 static int builtin_echo(char **argv);
618 static int builtin_eval(char **argv);
619 static int builtin_exec(char **argv);
620 static int builtin_exit(char **argv);
621 static int builtin_export(char **argv);
623 static int builtin_fg_bg(char **argv);
624 static int builtin_jobs(char **argv);
627 static int builtin_help(char **argv);
629 static int builtin_pwd(char **argv);
630 static int builtin_read(char **argv);
631 static int builtin_test(char **argv);
632 static int builtin_set(char **argv);
633 static int builtin_shift(char **argv);
634 static int builtin_source(char **argv);
635 static int builtin_umask(char **argv);
636 static int builtin_unset(char **argv);
637 //static int builtin_not_written(char **argv);
639 /* Table of built-in functions. They can be forked or not, depending on
640 * context: within pipes, they fork. As simple commands, they do not.
641 * When used in non-forking context, they can change global variables
642 * in the parent shell process. If forked, of course they cannot.
643 * For example, 'unset foo | whatever' will parse and run, but foo will
644 * still be set at the end. */
645 struct built_in_command {
646 const char *cmd; /* name */
647 int (*function) (char **argv); /* function ptr */
649 const char *descr; /* description */
650 #define BLTIN(cmd, func, help) { cmd, func, help }
652 #define BLTIN(cmd, func, help) { cmd, func }
656 /* For now, echo and test are unconditionally enabled.
657 * Maybe make it configurable? */
658 static const struct built_in_command bltins[] = {
659 BLTIN("[" , builtin_test, "Test condition"),
660 BLTIN("[[" , builtin_test, "Test condition"),
662 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
664 // BLTIN("break" , builtin_not_written, "Exit for, while or until loop"),
665 BLTIN("cd" , builtin_cd, "Change working directory"),
666 // BLTIN("continue", builtin_not_written, "Continue for, while or until loop"),
667 BLTIN("echo" , builtin_echo, "Write strings to stdout"),
668 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
669 BLTIN("exec" , builtin_exec, "Exec command, replacing this shell with the exec'd process"),
670 BLTIN("exit" , builtin_exit, "Exit from shell"),
671 BLTIN("export", builtin_export, "Set environment variable"),
673 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
674 BLTIN("jobs" , builtin_jobs, "Lists the active jobs"),
676 // TODO: remove pwd? we have it as an applet...
677 BLTIN("pwd" , builtin_pwd, "Print current directory"),
678 BLTIN("read" , builtin_read, "Input environment variable"),
679 // BLTIN("return", builtin_not_written, "Return from a function"),
680 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
681 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
682 // BLTIN("trap" , builtin_not_written, "Trap signals"),
683 BLTIN("test" , builtin_test, "Test condition"),
684 // BLTIN("ulimit", builtin_not_written, "Controls resource limits"),
685 BLTIN("umask" , builtin_umask, "Sets file creation mask"),
686 BLTIN("unset" , builtin_unset, "Unset environment variable"),
687 BLTIN("." , builtin_source, "Source-in and run commands in a file"),
689 BLTIN("help" , builtin_help, "List shell built-in commands"),
691 BLTIN(NULL, NULL, NULL)
697 static void signal_SA_RESTART(int sig, void (*handler)(int))
700 sa.sa_handler = handler;
701 sa.sa_flags = SA_RESTART;
702 sigemptyset(&sa.sa_mask);
703 sigaction(sig, &sa, NULL);
706 /* Signals are grouped, we handle them in batches */
707 static void set_fatal_sighandler(void (*handler)(int))
709 signal(SIGILL , handler);
710 signal(SIGTRAP, handler);
711 signal(SIGABRT, handler);
712 signal(SIGFPE , handler);
713 signal(SIGBUS , handler);
714 signal(SIGSEGV, handler);
715 /* bash 3.2 seems to handle these just like 'fatal' ones */
716 signal(SIGHUP , handler);
717 signal(SIGPIPE, handler);
718 signal(SIGALRM, handler);
720 static void set_jobctrl_sighandler(void (*handler)(int))
722 signal(SIGTSTP, handler);
723 signal(SIGTTIN, handler);
724 signal(SIGTTOU, handler);
726 static void set_misc_sighandler(void (*handler)(int))
728 signal(SIGINT , handler);
729 signal(SIGQUIT, handler);
730 signal(SIGTERM, handler);
732 /* SIGCHLD is special and handled separately */
734 static void set_every_sighandler(void (*handler)(int))
736 set_fatal_sighandler(handler);
737 set_jobctrl_sighandler(handler);
738 set_misc_sighandler(handler);
739 signal(SIGCHLD, handler);
742 static void handler_ctrl_c(int sig)
744 debug_printf_jobs("got sig %d\n", sig);
745 // as usual we can have all kinds of nasty problems with leaked malloc data here
746 siglongjmp(toplevel_jb, 1);
749 static void handler_ctrl_z(int sig)
753 debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
755 if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
758 if (!pid) { /* child */
760 debug_printf_jobs("set pgrp for child %d ok\n", getpid());
761 set_every_sighandler(SIG_DFL);
762 raise(SIGTSTP); /* resend TSTP so that child will be stopped */
763 debug_printf_jobs("returning in child\n");
764 /* return to nofork, it will eventually exit now,
765 * not return back to shell */
769 /* finish filling up pipe info */
770 toplevel_list->pgrp = pid; /* child is in its own pgrp */
771 toplevel_list->progs[0].pid = pid;
772 /* parent needs to longjmp out of running nofork.
773 * we will "return" exitcode 0, with child put in background */
774 // as usual we can have all kinds of nasty problems with leaked malloc data here
775 debug_printf_jobs("siglongjmp in parent\n");
776 siglongjmp(toplevel_jb, 1);
779 /* Restores tty foreground process group, and exits.
780 * May be called as signal handler for fatal signal
781 * (will faithfully resend signal to itself, producing correct exit state)
782 * or called directly with -EXITCODE.
783 * We also call it if xfunc is exiting. */
784 static void sigexit(int sig) ATTRIBUTE_NORETURN;
785 static void sigexit(int sig)
789 /* Disable all signals: job control, SIGPIPE, etc. */
790 sigfillset(&block_all);
791 sigprocmask(SIG_SETMASK, &block_all, NULL);
794 tcsetpgrp(interactive_fd, saved_tty_pgrp);
796 /* Not a signal, just exit */
800 /* Enable only this sig and kill ourself with it */
801 signal(sig, SIG_DFL);
802 sigdelset(&block_all, sig);
803 sigprocmask(SIG_SETMASK, &block_all, NULL);
805 _exit(1); /* Should not reach it */
808 /* Restores tty foreground process group, and exits. */
809 static void hush_exit(int exitcode) ATTRIBUTE_NORETURN;
810 static void hush_exit(int exitcode)
812 fflush(NULL); /* flush all streams */
813 sigexit(- (exitcode & 0xff));
818 #define set_fatal_sighandler(handler) ((void)0)
819 #define set_jobctrl_sighandler(handler) ((void)0)
820 #define set_misc_sighandler(handler) ((void)0)
821 #define hush_exit(e) exit(e)
826 static const char *set_cwd(void)
828 if (cwd == bb_msg_unknown)
829 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
830 cwd = xrealloc_getcwd_or_warn((char *)cwd);
832 cwd = bb_msg_unknown;
837 /* built-in 'test' handler */
838 static int builtin_test(char **argv)
845 return test_main(argc, argv - argc);
848 /* built-in 'test' handler */
849 static int builtin_echo(char **argv)
856 return echo_main(argc, argv - argc);
859 /* built-in 'eval' handler */
860 static int builtin_eval(char **argv)
862 int rcode = EXIT_SUCCESS;
865 char *str = expand_strvec_to_string(argv + 1);
866 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP |
867 PARSEFLAG_SEMICOLON);
869 rcode = last_return_code;
874 /* built-in 'cd <path>' handler */
875 static int builtin_cd(char **argv)
878 if (argv[1] == NULL) {
879 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
880 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
881 newdir = getenv("HOME") ? : "/";
885 printf("cd: %s: %s\n", newdir, strerror(errno));
892 /* built-in 'exec' handler */
893 static int builtin_exec(char **argv)
896 return EXIT_SUCCESS; /* Really? */
897 pseudo_exec_argv(argv + 1);
901 /* built-in 'exit' handler */
902 static int builtin_exit(char **argv)
904 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
905 //puts("exit"); /* bash does it */
906 // TODO: warn if we have background jobs: "There are stopped jobs"
907 // On second consecutive 'exit', exit anyway.
910 hush_exit(last_return_code);
911 /* mimic bash: exit 123abc == exit 255 + error msg */
912 xfunc_error_retval = 255;
913 /* bash: exit -2 == exit 254, no error msg */
914 hush_exit(xatoi(argv[1]) & 0xff);
917 /* built-in 'export VAR=value' handler */
918 static int builtin_export(char **argv)
921 char *name = argv[1];
925 // ash emits: export VAR='VAL'
926 // bash: declare -x VAR="VAL"
927 // (both also escape as needed (quotes, $, etc))
935 value = strchr(name, '=');
937 /* They are exporting something without a =VALUE */
938 struct variable *var;
940 var = get_local_var(name);
945 /* bash does not return an error when trying to export
946 * an undefined variable. Do likewise. */
950 set_local_var(xstrdup(name), 1);
955 /* built-in 'fg' and 'bg' handler */
956 static int builtin_fg_bg(char **argv)
963 /* If they gave us no args, assume they want the last backgrounded task */
965 for (pi = job_list; pi; pi = pi->next) {
966 if (pi->jobid == last_jobid) {
970 bb_error_msg("%s: no current job", argv[0]);
973 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
974 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
977 for (pi = job_list; pi; pi = pi->next) {
978 if (pi->jobid == jobnum) {
982 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
985 // TODO: bash prints a string representation
986 // of job being foregrounded (like "sleep 1 | cat")
987 if (*argv[0] == 'f') {
988 /* Put the job into the foreground. */
989 tcsetpgrp(interactive_fd, pi->pgrp);
992 /* Restart the processes in the job */
993 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
994 for (i = 0; i < pi->num_progs; i++) {
995 debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
996 pi->progs[i].is_stopped = 0;
998 pi->stopped_progs = 0;
1000 i = kill(- pi->pgrp, SIGCONT);
1002 if (errno == ESRCH) {
1003 delete_finished_bg_job(pi);
1004 return EXIT_SUCCESS;
1006 bb_perror_msg("kill (SIGCONT)");
1010 if (*argv[0] == 'f') {
1012 return checkjobs_and_fg_shell(pi);
1014 return EXIT_SUCCESS;
1018 /* built-in 'help' handler */
1019 #if ENABLE_HUSH_HELP
1020 static int builtin_help(char **argv ATTRIBUTE_UNUSED)
1022 const struct built_in_command *x;
1024 printf("\nBuilt-in commands:\n");
1025 printf("-------------------\n");
1026 for (x = bltins; x->cmd; x++) {
1027 printf("%s\t%s\n", x->cmd, x->descr);
1030 return EXIT_SUCCESS;
1035 /* built-in 'jobs' handler */
1036 static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
1039 const char *status_string;
1041 for (job = job_list; job; job = job->next) {
1042 if (job->running_progs == job->stopped_progs)
1043 status_string = "Stopped";
1045 status_string = "Running";
1047 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
1049 return EXIT_SUCCESS;
1053 /* built-in 'pwd' handler */
1054 static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
1057 return EXIT_SUCCESS;
1060 /* built-in 'read VAR' handler */
1061 static int builtin_read(char **argv)
1064 const char *name = argv[1] ? argv[1] : "REPLY";
1066 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name));
1067 return set_local_var(string, 0);
1070 /* built-in 'set [VAR=value]' handler */
1071 static int builtin_set(char **argv)
1073 char *temp = argv[1];
1077 for (e = top_var; e; e = e->next)
1080 set_local_var(xstrdup(temp), 0);
1082 return EXIT_SUCCESS;
1086 /* Built-in 'shift' handler */
1087 static int builtin_shift(char **argv)
1093 if (n >= 0 && n < global_argc) {
1094 global_argv[n] = global_argv[0];
1097 return EXIT_SUCCESS;
1099 return EXIT_FAILURE;
1102 /* Built-in '.' handler (read-in and execute commands from file) */
1103 static int builtin_source(char **argv)
1108 if (argv[1] == NULL)
1109 return EXIT_FAILURE;
1111 /* XXX search through $PATH is missing */
1112 input = fopen(argv[1], "r");
1114 bb_error_msg("cannot open '%s'", argv[1]);
1115 return EXIT_FAILURE;
1117 close_on_exec_on(fileno(input));
1119 /* Now run the file */
1120 /* XXX argv and argc are broken; need to save old global_argv
1121 * (pointer only is OK!) on this stack frame,
1122 * set global_argv=argv+1, recurse, and restore. */
1123 status = parse_and_run_file(input);
1128 static int builtin_umask(char **argv)
1131 const char *arg = argv[1];
1134 new_umask = strtoul(arg, &end, 8);
1135 if (*end != '\0' || end == arg) {
1136 return EXIT_FAILURE;
1139 new_umask = umask(0);
1140 printf("%.3o\n", (unsigned) new_umask);
1143 return EXIT_SUCCESS;
1146 /* built-in 'unset VAR' handler */
1147 static int builtin_unset(char **argv)
1149 /* bash always returns true */
1150 unset_local_var(argv[1]);
1151 return EXIT_SUCCESS;
1154 //static int builtin_not_written(char **argv)
1156 // printf("builtin_%s not written\n", argv[0]);
1157 // return EXIT_FAILURE;
1160 static int b_check_space(o_string *o, int len)
1162 /* It would be easy to drop a more restrictive policy
1163 * in here, such as setting a maximum string length */
1164 if (o->length + len > o->maxlen) {
1165 /* assert(data == NULL || o->maxlen != 0); */
1166 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1167 o->data = xrealloc(o->data, 1 + o->maxlen);
1169 return o->data == NULL;
1172 static int b_addchr(o_string *o, int ch)
1174 debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1175 if (b_check_space(o, 1))
1177 o->data[o->length] = ch;
1179 o->data[o->length] = '\0';
1183 static void b_reset(o_string *o)
1191 static void b_free(o_string *o)
1194 memset(o, 0, sizeof(*o));
1197 /* My analysis of quoting semantics tells me that state information
1198 * is associated with a destination, not a source.
1200 static int b_addqchr(o_string *o, int ch, int quote)
1202 if (quote && strchr("*?[\\", ch)) {
1204 rc = b_addchr(o, '\\');
1208 return b_addchr(o, ch);
1211 static int static_get(struct in_str *i)
1214 if (ch == '\0') return EOF;
1218 static int static_peek(struct in_str *i)
1223 #if ENABLE_HUSH_INTERACTIVE
1224 #if ENABLE_FEATURE_EDITING
1225 static void cmdedit_set_initial_prompt(void)
1227 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1230 PS1 = getenv("PS1");
1235 #endif /* EDITING */
1237 static const char* setup_prompt_string(int promptmode)
1239 const char *prompt_str;
1240 debug_printf("setup_prompt_string %d ", promptmode);
1241 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1242 /* Set up the prompt */
1243 if (promptmode == 0) { /* PS1 */
1245 PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#');
1251 prompt_str = (promptmode == 0) ? PS1 : PS2;
1253 debug_printf("result '%s'\n", prompt_str);
1257 static void get_user_input(struct in_str *i)
1260 const char *prompt_str;
1262 prompt_str = setup_prompt_string(i->promptmode);
1263 #if ENABLE_FEATURE_EDITING
1264 /* Enable command line editing only while a command line
1265 * is actually being read; otherwise, we'll end up bequeathing
1266 * atexit() handlers and other unwanted stuff to our
1267 * child processes (rob@sysgo.de) */
1268 r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state);
1269 i->eof_flag = (r < 0);
1270 if (i->eof_flag) { /* EOF/error detected */
1271 user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1272 user_input_buf[1] = '\0';
1275 fputs(prompt_str, stdout);
1277 user_input_buf[0] = r = fgetc(i->file);
1278 /*user_input_buf[1] = '\0'; - already is and never changed */
1279 i->eof_flag = (r == EOF);
1281 i->p = user_input_buf;
1283 #endif /* INTERACTIVE */
1285 /* This is the magic location that prints prompts
1286 * and gets data back from the user */
1287 static int file_get(struct in_str *i)
1291 /* If there is data waiting, eat it up */
1292 if (i->p && *i->p) {
1293 #if ENABLE_HUSH_INTERACTIVE
1297 if (i->eof_flag && !*i->p)
1300 /* need to double check i->file because we might be doing something
1301 * more complicated by now, like sourcing or substituting. */
1302 #if ENABLE_HUSH_INTERACTIVE
1303 if (interactive_fd && i->promptme && i->file == stdin) {
1306 } while (!*i->p); /* need non-empty line */
1307 i->promptmode = 1; /* PS2 */
1312 ch = fgetc(i->file);
1314 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1315 #if ENABLE_HUSH_INTERACTIVE
1322 /* All the callers guarantee this routine will never be
1323 * used right after a newline, so prompting is not needed.
1325 static int file_peek(struct in_str *i)
1328 if (i->p && *i->p) {
1329 if (i->eof_flag && !i->p[1])
1333 ch = fgetc(i->file);
1334 i->eof_flag = (ch == EOF);
1335 i->peek_buf[0] = ch;
1336 i->peek_buf[1] = '\0';
1338 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1342 static void setup_file_in_str(struct in_str *i, FILE *f)
1344 i->peek = file_peek;
1346 #if ENABLE_HUSH_INTERACTIVE
1348 i->promptmode = 0; /* PS1 */
1354 static void setup_string_in_str(struct in_str *i, const char *s)
1356 i->peek = static_peek;
1357 i->get = static_get;
1358 #if ENABLE_HUSH_INTERACTIVE
1360 i->promptmode = 0; /* PS1 */
1366 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1367 * and stderr if they are redirected. */
1368 static int setup_redirects(struct child_prog *prog, int squirrel[])
1371 struct redir_struct *redir;
1373 for (redir = prog->redirects; redir; redir = redir->next) {
1374 if (redir->dup == -1 && redir->glob_word == NULL) {
1375 /* something went wrong in the parse. Pretend it didn't happen */
1378 if (redir->dup == -1) {
1380 mode = redir_table[redir->type].mode;
1381 p = expand_string_to_string(redir->glob_word[0]);
1382 openfd = open_or_warn(p, mode);
1385 /* this could get lost if stderr has been redirected, but
1386 bash and ash both lose it as well (though zsh doesn't!) */
1390 openfd = redir->dup;
1393 if (openfd != redir->fd) {
1394 if (squirrel && redir->fd < 3) {
1395 squirrel[redir->fd] = dup(redir->fd);
1398 //close(openfd); // close(-3) ??!
1400 dup2(openfd, redir->fd);
1401 if (redir->dup == -1)
1409 static void restore_redirects(int squirrel[])
1412 for (i = 0; i < 3; i++) {
1415 /* We simply die on error */
1421 /* Called after [v]fork() in run_pipe_real(), or from builtin_exec().
1423 * XXX no exit() here. If you don't exec, use _exit instead.
1424 * The at_exit handlers apparently confuse the calling process,
1425 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
1426 static void pseudo_exec_argv(char **argv)
1430 const struct built_in_command *x;
1432 for (i = 0; is_assignment(argv[i]); i++) {
1433 debug_printf_exec("pid %d environment modification: %s\n",
1435 // FIXME: vfork case??
1436 p = expand_string_to_string(argv[i]);
1440 /* If a variable is assigned in a forest, and nobody listens,
1441 * was it ever really set?
1443 if (argv[0] == NULL) {
1444 _exit(EXIT_SUCCESS);
1447 argv = expand_strvec_to_strvec(argv);
1450 * Check if the command matches any of the builtins.
1451 * Depending on context, this might be redundant. But it's
1452 * easier to waste a few CPU cycles than it is to figure out
1453 * if this is one of those cases.
1455 for (x = bltins; x->cmd; x++) {
1456 if (strcmp(argv[0], x->cmd) == 0) {
1457 debug_printf_exec("running builtin '%s'\n", argv[0]);
1458 rcode = x->function(argv);
1464 /* Check if the command matches any busybox applets */
1465 #if ENABLE_FEATURE_SH_STANDALONE
1466 if (strchr(argv[0], '/') == NULL) {
1467 int a = find_applet_by_name(argv[0]);
1469 if (APPLET_IS_NOEXEC(a)) {
1470 debug_printf_exec("running applet '%s'\n", argv[0]);
1471 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
1472 run_applet_no_and_exit(a, argv);
1474 /* re-exec ourselves with the new arguments */
1475 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
1476 execvp(bb_busybox_exec_path, argv);
1477 /* If they called chroot or otherwise made the binary no longer
1478 * executable, fall through */
1483 debug_printf_exec("execing '%s'\n", argv[0]);
1484 execvp(argv[0], argv);
1485 bb_perror_msg("cannot exec '%s'", argv[0]);
1489 /* Called after [v]fork() in run_pipe_real()
1491 static void pseudo_exec(struct child_prog *child)
1493 // FIXME: buggy wrt NOMMU! Must not modify any global data
1494 // until it does exec/_exit, but currently it does.
1498 pseudo_exec_argv(child->argv);
1503 bb_error_msg_and_exit("nested lists are not supported on NOMMU");
1505 #if ENABLE_HUSH_INTERACTIVE
1506 debug_printf_exec("pseudo_exec: setting interactive_fd=0\n");
1507 interactive_fd = 0; /* crucial!!!! */
1509 debug_printf_exec("pseudo_exec: run_list_real\n");
1510 rcode = run_list_real(child->group);
1511 /* OK to leak memory by not calling free_pipe_list,
1512 * since this process is about to exit */
1517 /* Can happen. See what bash does with ">foo" by itself. */
1518 debug_printf("trying to pseudo_exec null command\n");
1519 _exit(EXIT_SUCCESS);
1523 static const char *get_cmdtext(struct pipe *pi)
1529 /* This is subtle. ->cmdtext is created only on first backgrounding.
1530 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
1531 * On subsequent bg argv is trashed, but we won't use it */
1534 argv = pi->progs[0].argv;
1535 if (!argv || !argv[0])
1536 return (pi->cmdtext = xzalloc(1));
1539 do len += strlen(*argv) + 1; while (*++argv);
1540 pi->cmdtext = p = xmalloc(len);
1541 argv = pi->progs[0].argv;
1543 len = strlen(*argv);
1544 memcpy(p, *argv, len);
1552 static void insert_bg_job(struct pipe *pi)
1554 struct pipe *thejob;
1557 /* Linear search for the ID of the job to use */
1559 for (thejob = job_list; thejob; thejob = thejob->next)
1560 if (thejob->jobid >= pi->jobid)
1561 pi->jobid = thejob->jobid + 1;
1563 /* Add thejob to the list of running jobs */
1565 thejob = job_list = xmalloc(sizeof(*thejob));
1567 for (thejob = job_list; thejob->next; thejob = thejob->next)
1569 thejob->next = xmalloc(sizeof(*thejob));
1570 thejob = thejob->next;
1573 /* Physically copy the struct job */
1574 memcpy(thejob, pi, sizeof(struct pipe));
1575 thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs);
1576 /* We cannot copy entire pi->progs[] vector! Double free()s will happen */
1577 for (i = 0; i < pi->num_progs; i++) {
1578 // TODO: do we really need to have so many fields which are just dead weight
1579 // at execution stage?
1580 thejob->progs[i].pid = pi->progs[i].pid;
1581 /* all other fields are not used and stay zero */
1583 thejob->next = NULL;
1584 thejob->cmdtext = xstrdup(get_cmdtext(pi));
1586 /* We don't wait for background thejobs to return -- append it
1587 to the list of backgrounded thejobs and leave it alone */
1588 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
1589 last_bg_pid = thejob->progs[0].pid;
1590 last_jobid = thejob->jobid;
1593 static void remove_bg_job(struct pipe *pi)
1595 struct pipe *prev_pipe;
1597 if (pi == job_list) {
1598 job_list = pi->next;
1600 prev_pipe = job_list;
1601 while (prev_pipe->next != pi)
1602 prev_pipe = prev_pipe->next;
1603 prev_pipe->next = pi->next;
1606 last_jobid = job_list->jobid;
1611 /* remove a backgrounded job */
1612 static void delete_finished_bg_job(struct pipe *pi)
1615 pi->stopped_progs = 0;
1621 /* Checks to see if any processes have exited -- if they
1622 have, figure out why and see if a job has completed */
1623 static int checkjobs(struct pipe* fg_pipe)
1634 attributes = WUNTRACED;
1635 if (fg_pipe == NULL) {
1636 attributes |= WNOHANG;
1639 /* Do we do this right?
1640 * bash-3.00# sleep 20 | false
1642 * [3]+ Stopped sleep 20 | false
1643 * bash-3.00# echo $?
1644 * 1 <========== bg pipe is not fully done, but exitcode is already known!
1647 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
1648 //are stopped. Testcase: "cat | cat" in a script (not on command line)
1649 // + killall -STOP cat
1652 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1653 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
1655 #ifdef DEBUG_SHELL_JOBS
1656 if (WIFSTOPPED(status))
1657 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
1658 childpid, WSTOPSIG(status), WEXITSTATUS(status));
1659 if (WIFSIGNALED(status))
1660 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
1661 childpid, WTERMSIG(status), WEXITSTATUS(status));
1662 if (WIFEXITED(status))
1663 debug_printf_jobs("pid %d exited, exitcode %d\n",
1664 childpid, WEXITSTATUS(status));
1666 /* Were we asked to wait for fg pipe? */
1669 for (i = 0; i < fg_pipe->num_progs; i++) {
1670 debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid);
1671 if (fg_pipe->progs[i].pid == childpid) {
1672 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
1674 fg_pipe->progs[i].pid = 0;
1675 fg_pipe->running_progs--;
1676 if (i == fg_pipe->num_progs-1)
1677 /* last process gives overall exitstatus */
1678 rcode = WEXITSTATUS(status);
1680 fg_pipe->progs[i].is_stopped = 1;
1681 fg_pipe->stopped_progs++;
1683 debug_printf_jobs("fg_pipe: running_progs %d stopped_progs %d\n",
1684 fg_pipe->running_progs, fg_pipe->stopped_progs);
1685 if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) {
1686 /* All processes in fg pipe have exited/stopped */
1688 if (fg_pipe->running_progs)
1689 insert_bg_job(fg_pipe);
1693 /* There are still running processes in the fg pipe */
1697 /* fall through to searching process in bg pipes */
1701 /* We asked to wait for bg or orphaned children */
1702 /* No need to remember exitcode in this case */
1703 for (pi = job_list; pi; pi = pi->next) {
1705 while (prognum < pi->num_progs) {
1706 if (pi->progs[prognum].pid == childpid)
1707 goto found_pi_and_prognum;
1713 /* Happens when shell is used as init process (init=/bin/sh) */
1714 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1718 found_pi_and_prognum:
1721 pi->progs[prognum].pid = 0;
1722 pi->running_progs--;
1723 if (!pi->running_progs) {
1724 printf(JOB_STATUS_FORMAT, pi->jobid,
1725 "Done", pi->cmdtext);
1726 delete_finished_bg_job(pi);
1730 pi->stopped_progs++;
1731 pi->progs[prognum].is_stopped = 1;
1736 /* wait found no children or failed */
1738 if (childpid && errno != ECHILD)
1739 bb_perror_msg("waitpid");
1744 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
1747 int rcode = checkjobs(fg_pipe);
1748 /* Job finished, move the shell to the foreground */
1749 p = getpgid(0); /* pgid of our process */
1750 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
1751 if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
1752 bb_perror_msg("tcsetpgrp-4a");
1757 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1758 * to finish. See checkjobs().
1760 * return code is normally -1, when the caller has to wait for children
1761 * to finish to determine the exit status of the pipe. If the pipe
1762 * is a simple builtin command, however, the action is done by the
1763 * time run_pipe_real returns, and the exit code is provided as the
1766 * The input of the pipe is always stdin, the output is always
1767 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1768 * because it tries to avoid running the command substitution in
1769 * subshell, when that is in fact necessary. The subshell process
1770 * now has its stdout directed to the input of the appropriate pipe,
1771 * so this routine is noticeably simpler.
1773 * Returns -1 only if started some children. IOW: we have to
1774 * mask out retvals of builtins etc with 0xff!
1776 static int run_pipe_real(struct pipe *pi)
1779 int nextin, nextout;
1780 int pipefds[2]; /* pipefds[0] is for reading */
1781 struct child_prog *child;
1782 const struct built_in_command *x;
1784 /* it is not always needed, but we aim to smaller code */
1785 int squirrel[] = { -1, -1, -1 };
1787 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
1789 debug_printf_exec("run_pipe_real start: single_fg=%d\n", single_fg);
1795 pi->running_progs = 1;
1796 pi->stopped_progs = 0;
1798 /* Check if this is a simple builtin (not part of a pipe).
1799 * Builtins within pipes have to fork anyway, and are handled in
1800 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1802 child = &(pi->progs[0]);
1803 if (single_fg && child->group && child->subshell == 0) {
1804 debug_printf("non-subshell grouping\n");
1805 setup_redirects(child, squirrel);
1806 debug_printf_exec(": run_list_real\n");
1807 rcode = run_list_real(child->group);
1808 restore_redirects(squirrel);
1809 debug_printf_exec("run_pipe_real return %d\n", rcode);
1810 return rcode; // do we need to add '... & 0xff' ?
1813 if (single_fg && child->argv != NULL) {
1814 char **argv_expanded;
1815 char **argv = child->argv;
1817 for (i = 0; is_assignment(argv[i]); i++)
1819 if (i != 0 && argv[i] == NULL) {
1820 /* assignments, but no command: set the local environment */
1821 for (i = 0; argv[i] != NULL; i++) {
1822 debug_printf("local environment set: %s\n", argv[i]);
1823 p = expand_string_to_string(argv[i]);
1824 set_local_var(p, 0);
1826 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1828 for (i = 0; is_assignment(argv[i]); i++) {
1829 p = expand_string_to_string(argv[i]);
1833 for (x = bltins; x->cmd; x++) {
1834 if (strcmp(argv[i], x->cmd) == 0) {
1835 if (x->function == builtin_exec && argv[i+1] == NULL) {
1836 debug_printf("magic exec\n");
1837 setup_redirects(child, NULL);
1838 return EXIT_SUCCESS;
1840 debug_printf("builtin inline %s\n", argv[0]);
1841 /* XXX setup_redirects acts on file descriptors, not FILEs.
1842 * This is perfect for work that comes after exec().
1843 * Is it really safe for inline use? Experimentally,
1844 * things seem to work with glibc. */
1845 setup_redirects(child, squirrel);
1846 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
1847 //sp: if (child->sp) /* btw we can do it unconditionally... */
1848 argv_expanded = expand_strvec_to_strvec(argv + i);
1849 rcode = x->function(argv_expanded) & 0xff;
1850 free(argv_expanded);
1851 restore_redirects(squirrel);
1852 debug_printf_exec("run_pipe_real return %d\n", rcode);
1856 #if ENABLE_FEATURE_SH_STANDALONE
1858 int a = find_applet_by_name(argv[i]);
1859 if (a >= 0 && APPLET_IS_NOFORK(a)) {
1860 setup_redirects(child, squirrel);
1861 save_nofork_data(&nofork_save);
1862 argv_expanded = argv + i;
1863 //sp: if (child->sp)
1864 argv_expanded = expand_strvec_to_strvec(argv + i);
1865 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
1866 rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded) & 0xff;
1867 free(argv_expanded);
1868 restore_redirects(squirrel);
1869 debug_printf_exec("run_pipe_real return %d\n", rcode);
1876 /* Going to fork a child per each pipe member */
1877 pi->running_progs = 0;
1879 /* Disable job control signals for shell (parent) and
1880 * for initial child code after fork */
1881 set_jobctrl_sighandler(SIG_IGN);
1883 for (i = 0; i < pi->num_progs; i++) {
1884 child = &(pi->progs[i]);
1886 debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
1888 debug_printf_exec(": pipe member with no argv\n");
1890 /* pipes are inserted between pairs of commands */
1891 if ((i + 1) < pi->num_progs) {
1893 nextout = pipefds[1];
1899 /* XXX test for failed fork()? */
1901 child->pid = fork();
1903 child->pid = vfork();
1905 if (!child->pid) { /* child */
1906 /* Every child adds itself to new process group
1907 * with pgid == pid of first child in pipe */
1909 if (run_list_level == 1 && interactive_fd) {
1910 /* Don't do pgrp restore anymore on fatal signals */
1911 set_fatal_sighandler(SIG_DFL);
1912 if (pi->pgrp < 0) /* true for 1st process only */
1913 pi->pgrp = getpid();
1914 if (setpgid(0, pi->pgrp) == 0 && pi->followup != PIPE_BG) {
1915 /* We do it in *every* child, not just first,
1917 tcsetpgrp(interactive_fd, pi->pgrp);
1921 /* in non-interactive case fatal sigs are already SIG_DFL */
1922 xmove_fd(nextin, 0);
1923 xmove_fd(nextout, 1);
1924 if (pipefds[0] != -1) {
1925 close(pipefds[0]); /* opposite end of our output pipe */
1927 /* Like bash, explicit redirects override pipes,
1928 * and the pipe fd is available for dup'ing. */
1929 setup_redirects(child, NULL);
1931 /* Restore default handlers just prior to exec */
1932 set_jobctrl_sighandler(SIG_DFL);
1933 set_misc_sighandler(SIG_DFL);
1934 signal(SIGCHLD, SIG_DFL);
1938 pi->running_progs++;
1941 /* Second and next children need to know pid of first one */
1943 pi->pgrp = child->pid;
1950 /* If there isn't another process, nextin is garbage
1951 but it doesn't matter */
1952 nextin = pipefds[0];
1954 debug_printf_exec("run_pipe_real return -1\n");
1958 #ifndef debug_print_tree
1959 static void debug_print_tree(struct pipe *pi, int lvl)
1961 static const char *PIPE[] = {
1967 static const char *RES[] = {
1968 [RES_NONE ] = "NONE" ,
1971 [RES_THEN ] = "THEN" ,
1972 [RES_ELIF ] = "ELIF" ,
1973 [RES_ELSE ] = "ELSE" ,
1976 #if ENABLE_HUSH_LOOPS
1977 [RES_FOR ] = "FOR" ,
1978 [RES_WHILE] = "WHILE",
1979 [RES_UNTIL] = "UNTIL",
1981 [RES_DONE ] = "DONE" ,
1984 [RES_XXXX ] = "XXXX" ,
1985 [RES_SNTX ] = "SNTX" ,
1992 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
1993 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
1995 while (prn < pi->num_progs) {
1996 struct child_prog *child = &pi->progs[prn];
1997 char **argv = child->argv;
1999 fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
2001 fprintf(stderr, " group %s: (argv=%p)\n",
2002 (child->subshell ? "()" : "{}"),
2004 debug_print_tree(child->group, lvl+1);
2008 if (argv) while (*argv) {
2009 fprintf(stderr, " '%s'", *argv);
2012 fprintf(stderr, "\n");
2021 /* NB: called by pseudo_exec, and therefore must not modify any
2022 * global data until exec/_exit (we can be a child after vfork!) */
2023 static int run_list_real(struct pipe *pi)
2026 #if ENABLE_HUSH_LOOPS
2027 char *for_varname = NULL;
2028 char **for_lcur = NULL;
2029 char **for_list = NULL;
2034 int rcode = 0; /* probably for gcc only */
2035 int flag_restore = 0;
2037 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
2039 enum { if_code = 0, next_if_code = 0 };
2041 reserved_style rword;
2042 reserved_style skip_more_for_this_rword = RES_XXXX;
2044 debug_printf_exec("run_list_real start lvl %d\n", run_list_level + 1);
2046 #if ENABLE_HUSH_LOOPS
2047 /* check syntax for "for" */
2048 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
2049 if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR)
2050 && (rpipe->next == NULL)
2052 syntax("malformed for"); /* no IN or no commands after IN */
2053 debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level);
2056 if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL)
2057 || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN)
2059 /* TODO: what is tested in the first condition? */
2060 syntax("malformed for"); /* 2nd condition: not followed by IN */
2061 debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level);
2070 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2071 * We are saving state before entering outermost list ("while...done")
2072 * so that ctrl-Z will correctly background _entire_ outermost list,
2073 * not just a part of it (like "sleep 1 | exit 2") */
2074 if (++run_list_level == 1 && interactive_fd) {
2075 if (sigsetjmp(toplevel_jb, 1)) {
2076 /* ctrl-Z forked and we are parent; or ctrl-C.
2077 * Sighandler has longjmped us here */
2078 signal(SIGINT, SIG_IGN);
2079 signal(SIGTSTP, SIG_IGN);
2080 /* Restore level (we can be coming from deep inside
2083 #if ENABLE_FEATURE_SH_STANDALONE
2084 if (nofork_save.saved) { /* if save area is valid */
2085 debug_printf_jobs("exiting nofork early\n");
2086 restore_nofork_data(&nofork_save);
2090 /* ctrl-Z has forked and stored pid of the child in pi->pid.
2091 * Remember this child as background job */
2094 /* ctrl-C. We just stop doing whatever we were doing */
2100 /* ctrl-Z handler will store pid etc in pi */
2103 #if ENABLE_FEATURE_SH_STANDALONE
2104 nofork_save.saved = 0; /* in case we will run a nofork later */
2106 signal_SA_RESTART(SIGTSTP, handler_ctrl_z);
2107 signal(SIGINT, handler_ctrl_c);
2111 for (; pi; pi = flag_restore ? rpipe : pi->next) {
2112 rword = pi->res_word;
2113 #if ENABLE_HUSH_LOOPS
2114 if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
2122 debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n",
2123 rword, if_code, next_if_code, skip_more_for_this_rword);
2124 if (rword == skip_more_for_this_rword && flag_skip) {
2125 if (pi->followup == PIPE_SEQ)
2130 skip_more_for_this_rword = RES_XXXX;
2132 if (rword == RES_THEN || rword == RES_ELSE)
2133 if_code = next_if_code;
2134 if (rword == RES_THEN && if_code)
2136 if (rword == RES_ELSE && !if_code)
2138 if (rword == RES_ELIF && !if_code)
2141 #if ENABLE_HUSH_LOOPS
2142 if (rword == RES_FOR && pi->num_progs) {
2144 /* first loop through for */
2145 /* if no variable values after "in" we skip "for" */
2146 if (!pi->next->progs->argv)
2148 /* create list of variable values */
2149 for_list = expand_strvec_to_strvec(pi->next->progs->argv);
2150 for_lcur = for_list;
2151 for_varname = pi->progs->argv[0];
2152 pi->progs->argv[0] = NULL;
2155 free(pi->progs->argv[0]);
2157 /* for loop is over, clean up */
2161 pi->progs->argv[0] = for_varname;
2164 /* insert next value from for_lcur */
2165 /* vda: does it need escaping? */
2166 pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
2168 if (rword == RES_IN)
2170 if (rword == RES_DO) {
2174 if (rword == RES_DONE) {
2182 if (pi->num_progs == 0)
2184 save_num_progs = pi->num_progs; /* save number of programs */
2185 debug_printf_exec(": run_pipe_real with %d members\n", pi->num_progs);
2186 rcode = run_pipe_real(pi);
2188 /* We only ran a builtin: rcode was set by the return value
2189 * of run_pipe_real(), and we don't need to wait for anything. */
2190 } else if (pi->followup == PIPE_BG) {
2191 /* What does bash do with attempts to background builtins? */
2192 /* Even bash 3.2 doesn't do that well with nested bg:
2193 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
2194 * I'm NOT treating inner &'s as jobs */
2196 if (run_list_level == 1)
2199 rcode = EXIT_SUCCESS;
2202 /* Paranoia, just "interactive_fd" should be enough? */
2203 if (run_list_level == 1 && interactive_fd) {
2204 /* waits for completion, then fg's main shell */
2205 rcode = checkjobs_and_fg_shell(pi);
2209 /* this one just waits for completion */
2210 rcode = checkjobs(pi);
2212 debug_printf_exec(": checkjobs returned %d\n", rcode);
2214 debug_printf_exec(": setting last_return_code=%d\n", rcode);
2215 last_return_code = rcode;
2216 pi->num_progs = save_num_progs; /* restore number of programs */
2218 if (rword == RES_IF || rword == RES_ELIF)
2219 next_if_code = rcode; /* can be overwritten a number of times */
2221 #if ENABLE_HUSH_LOOPS
2222 if (rword == RES_WHILE)
2223 flag_rep = !last_return_code;
2224 if (rword == RES_UNTIL)
2225 flag_rep = last_return_code;
2227 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
2228 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
2230 skip_more_for_this_rword = rword;
2237 /* ctrl-Z forked somewhere in the past, we are the child,
2238 * and now we completed running the list. Exit. */
2242 if (!--run_list_level && interactive_fd) {
2243 signal(SIGTSTP, SIG_IGN);
2244 signal(SIGINT, SIG_IGN);
2247 debug_printf_exec("run_list_real lvl %d return %d\n", run_list_level + 1, rcode);
2251 /* return code is the exit status of the pipe */
2252 static int free_pipe(struct pipe *pi, int indent)
2255 struct child_prog *child;
2256 struct redir_struct *r, *rnext;
2257 int a, i, ret_code = 0;
2259 if (pi->stopped_progs > 0)
2261 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2262 for (i = 0; i < pi->num_progs; i++) {
2263 child = &pi->progs[i];
2264 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2266 for (a = 0, p = child->argv; *p; a++, p++) {
2267 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2269 free_strings(child->argv);
2271 } else if (child->group) {
2272 debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
2273 ret_code = free_pipe_list(child->group, indent+3);
2274 debug_printf_clean("%s end group\n", indenter(indent));
2276 debug_printf_clean("%s (nil)\n", indenter(indent));
2278 for (r = child->redirects; r; r = rnext) {
2279 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
2281 /* guard against the case >$FOO, where foo is unset or blank */
2283 debug_printf_clean(" %s\n", r->glob_word[0]);
2284 free_strings(r->glob_word);
2285 r->glob_word = NULL;
2288 debug_printf_clean("&%d\n", r->dup);
2293 child->redirects = NULL;
2295 free(pi->progs); /* children are an array, they get freed all at once */
2304 static int free_pipe_list(struct pipe *head, int indent)
2306 int rcode = 0; /* if list has no members */
2307 struct pipe *pi, *next;
2309 for (pi = head; pi; pi = next) {
2310 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2311 rcode = free_pipe(pi, indent);
2312 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2314 /*pi->next = NULL;*/
2320 /* Select which version we will use */
2321 static int run_list(struct pipe *pi)
2324 debug_printf_exec("run_list entered\n");
2325 if (fake_mode == 0) {
2326 debug_printf_exec(": run_list_real with %d members\n", pi->num_progs);
2327 rcode = run_list_real(pi);
2329 /* free_pipe_list has the side effect of clearing memory.
2330 * In the long run that function can be merged with run_list_real,
2331 * but doing that now would hobble the debugging effort. */
2332 free_pipe_list(pi, 0);
2333 debug_printf_exec("run_list return %d\n", rcode);
2337 /* Whoever decided to muck with glob internal data is AN IDIOT! */
2338 /* uclibc happily changed the way it works (and it has rights to do so!),
2339 all hell broke loose (SEGVs) */
2341 /* The API for glob is arguably broken. This routine pushes a non-matching
2342 * string into the output structure, removing non-backslashed backslashes.
2343 * If someone can prove me wrong, by performing this function within the
2344 * original glob(3) api, feel free to rewrite this routine into oblivion.
2345 * XXX broken if the last character is '\\', check that before calling.
2347 static char **globhack(const char *src, char **strings)
2353 for (cnt = 1, s = src; s && *s; s++) {
2354 if (*s == '\\') s++;
2357 v = dest = xmalloc(cnt);
2358 for (s = src; s && *s; s++, dest++) {
2359 if (*s == '\\') s++;
2364 return add_string_to_strings(strings, v);
2367 /* XXX broken if the last character is '\\', check that before calling */
2368 static int glob_needed(const char *s)
2373 if (strchr("*[?", *s))
2379 static int xglob(o_string *dest, char ***pglob)
2381 /* short-circuit for null word */
2382 /* we can code this better when the debug_printf's are gone */
2383 if (dest->length == 0) {
2384 if (dest->nonnull) {
2385 /* bash man page calls this an "explicit" null */
2386 *pglob = globhack(dest->data, *pglob);
2391 if (glob_needed(dest->data)) {
2395 memset(&globdata, 0, sizeof(globdata));
2396 gr = glob(dest->data, 0, NULL, &globdata);
2397 debug_printf("glob returned %d\n", gr);
2398 if (gr == GLOB_NOSPACE)
2399 bb_error_msg_and_die("out of memory during glob");
2400 if (gr == GLOB_NOMATCH) {
2401 debug_printf("globhack returned %d\n", gr);
2402 /* quote removal, or more accurately, backslash removal */
2403 *pglob = globhack(dest->data, *pglob);
2404 globfree(&globdata);
2407 if (gr != 0) { /* GLOB_ABORTED ? */
2408 bb_error_msg("glob(3) error %d", gr);
2410 if (globdata.gl_pathv && globdata.gl_pathv[0])
2411 *pglob = add_strings_to_strings(1, *pglob, globdata.gl_pathv);
2412 globfree(&globdata);
2416 *pglob = globhack(dest->data, *pglob);
2420 /* expand_strvec_to_strvec() takes a list of strings, expands
2421 * all variable references within and returns a pointer to
2422 * a list of expanded strings, possibly with larger number
2423 * of strings. (Think VAR="a b"; echo $VAR).
2424 * This new list is allocated as a single malloc block.
2425 * NULL-terminated list of char* pointers is at the beginning of it,
2426 * followed by strings themself.
2427 * Caller can deallocate entire list by single free(list). */
2430 * count_XXX estimates size of the block we need. It's okay
2431 * to over-estimate sizes a bit, if it makes code simpler */
2432 static int count_ifs(const char *str)
2435 debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs);
2437 str += strcspn(str, ifs);
2439 str++; /* str += strspn(str, ifs); */
2440 cnt++; /* cnt += strspn(str, ifs); - but this code is larger */
2442 debug_printf_expand(" return %d\n", cnt);
2446 static void count_var_expansion_space(int *countp, int *lenp, char *arg)
2451 int count = *countp;
2455 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
2458 p = strchr(p, SPECIAL_VAR_SYMBOL);
2461 switch (first_ch & 0x7f) {
2462 /* high bit in 1st_ch indicates that var is double-quoted */
2464 case '!': /* bg pid */
2465 case '?': /* exitcode */
2466 case '#': /* argc */
2467 len += sizeof(int)*3 + 1; /* enough for int */
2471 for (i = 1; global_argv[i]; i++) {
2472 len += strlen(global_argv[i]) + 1;
2474 if (!(first_ch & 0x80))
2475 count += count_ifs(global_argv[i]);
2480 arg[0] = first_ch & 0x7f;
2481 if (isdigit(arg[0])) {
2484 if (i < global_argc)
2485 val = global_argv[i];
2487 val = lookup_param(arg);
2489 *p = SPECIAL_VAR_SYMBOL;
2492 len += strlen(val) + 1;
2493 if (!(first_ch & 0x80))
2494 count += count_ifs(val);
2500 len += strlen(arg) + 1;
2506 /* Store given string, finalizing the word and starting new one whenever
2507 * we encounter ifs char(s). This is used for expanding variable values.
2508 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2509 static int expand_on_ifs(char **list, int n, char **posp, const char *str)
2513 int word_len = strcspn(str, ifs);
2515 memcpy(pos, str, word_len); /* store non-ifs chars */
2519 if (!*str) /* EOL - do not finalize word */
2522 if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' "
2523 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2524 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2526 str += strspn(str, ifs); /* skip ifs chars */
2532 /* Expand all variable references in given string, adding words to list[]
2533 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2534 * to be filled). This routine is extremely tricky: has to deal with
2535 * variables/parameters with whitespace, $* and $@, and constructs like
2536 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2537 /* NB: another bug is that we cannot detect empty strings yet:
2538 * "" or $empty"" expands to zero words, has to expand to empty word */
2539 static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask)
2541 /* or_mask is either 0 (normal case) or 0x80
2542 * (expansion of right-hand side of assignment == 1-element expand) */
2544 char first_ch, ored_ch;
2552 if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' "
2553 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2554 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2557 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
2558 memcpy(pos, arg, p - arg);
2561 p = strchr(p, SPECIAL_VAR_SYMBOL);
2563 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2564 ored_ch |= first_ch;
2566 switch (first_ch & 0x7f) {
2567 /* Highest bit in first_ch indicates that var is double-quoted */
2569 /* FIXME: (echo $$) should still print pid of main shell */
2570 val = utoa(getpid());
2572 case '!': /* bg pid */
2573 val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
2575 case '?': /* exitcode */
2576 val = utoa(last_return_code);
2578 case '#': /* argc */
2579 val = utoa(global_argc ? global_argc-1 : 0);
2584 if (!global_argv[i])
2586 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2587 while (global_argv[i]) {
2588 n = expand_on_ifs(list, n, &pos, global_argv[i]);
2589 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
2590 if (global_argv[i++][0] && global_argv[i]) {
2591 /* this argv[] is not empty and not last:
2592 * put terminating NUL, start new word */
2594 if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' "
2595 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2596 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2601 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2602 * and in this case should treat it like '$*' - see 'else...' below */
2603 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2605 strcpy(pos, global_argv[i]);
2606 pos += strlen(global_argv[i]);
2607 if (++i >= global_argc)
2610 if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' "
2611 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2612 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2615 } else { /* quoted $*: add as one word */
2617 strcpy(pos, global_argv[i]);
2618 pos += strlen(global_argv[i]);
2619 if (!global_argv[++i])
2628 arg[0] = first_ch & 0x7f;
2629 if (isdigit(arg[0])) {
2632 if (i < global_argc)
2633 val = global_argv[i];
2635 val = lookup_param(arg);
2637 *p = SPECIAL_VAR_SYMBOL;
2638 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2640 n = expand_on_ifs(list, n, &pos, val);
2643 } /* else: quoted $VAR, val will be appended at pos */
2651 debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos);
2653 pos += strlen(arg) + 1;
2654 if (pos == list[n-1] + 1) { /* expansion is empty */
2655 if (!(ored_ch & 0x80)) { /* all vars were not quoted... */
2656 debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n);
2666 static char **expand_variables(char **argv, char or_mask)
2671 char *pos, **v, **list;
2674 if (!*v) debug_printf_expand("count_var_expansion_space: "
2675 "argv[0]=NULL count=%d len=%d alloc_space=%d\n",
2676 count, len, sizeof(char*) * count + len);
2678 count_var_expansion_space(&count, &len, *v);
2679 debug_printf_expand("count_var_expansion_space: "
2680 "'%s' count=%d len=%d alloc_space=%d\n",
2681 *v, count, len, sizeof(char*) * count + len);
2684 len += sizeof(char*) * count; /* total to alloc */
2685 list = xmalloc(len);
2686 pos = (char*)(list + count);
2687 debug_printf_expand("list=%p, list[0] should be %p\n", list, pos);
2691 n = expand_vars_to_list(list, n, &pos, *v++, or_mask);
2693 if (n) debug_printf_expand("finalized list[%d]=%p '%s' "
2694 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2695 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2702 debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]);
2705 debug_printf_expand("used_space=%d\n", pos - (char*)list);
2708 if (ENABLE_HUSH_DEBUG)
2709 if (pos - (char*)list > len)
2710 bb_error_msg_and_die("BUG in varexp");
2714 static char **expand_strvec_to_strvec(char **argv)
2716 return expand_variables(argv, 0);
2719 static char *expand_string_to_string(const char *str)
2721 char *argv[2], **list;
2723 argv[0] = (char*)str;
2725 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2726 if (ENABLE_HUSH_DEBUG)
2727 if (!list[0] || list[1])
2728 bb_error_msg_and_die("BUG in varexp2");
2729 /* actually, just move string 2*sizeof(char*) bytes back */
2730 strcpy((char*)list, list[0]);
2731 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2735 static char* expand_strvec_to_string(char **argv)
2739 list = expand_variables(argv, 0x80);
2740 /* Convert all NULs to spaces */
2744 if (ENABLE_HUSH_DEBUG)
2745 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2746 bb_error_msg_and_die("BUG in varexp3");
2747 list[n][-1] = ' '; /* TODO: or to ifs[0]? */
2751 strcpy((char*)list, list[0]);
2752 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2756 /* This is used to get/check local shell variables */
2757 static struct variable *get_local_var(const char *name)
2759 struct variable *cur;
2765 for (cur = top_var; cur; cur = cur->next) {
2766 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2772 /* str holds "NAME=VAL" and is expected to be malloced.
2773 * We take ownership of it. */
2774 static int set_local_var(char *str, int flg_export)
2776 struct variable *cur;
2780 value = strchr(str, '=');
2781 if (!value) { /* not expected to ever happen? */
2786 name_len = value - str + 1; /* including '=' */
2787 cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
2789 if (strncmp(cur->varstr, str, name_len) != 0) {
2791 /* Bail out. Note that now cur points
2792 * to last var in linked list */
2798 /* We found an existing var with this name */
2800 if (cur->flg_read_only) {
2801 bb_error_msg("%s: readonly variable", str);
2805 unsetenv(str); /* just in case */
2807 if (strcmp(cur->varstr, str) == 0) {
2812 if (cur->max_len >= strlen(str)) {
2813 /* This one is from startup env, reuse space */
2814 strcpy(cur->varstr, str);
2817 /* max_len == 0 signifies "malloced" var, which we can
2818 * (and has to) free */
2822 goto set_str_and_exp;
2825 /* Not found - create next variable struct */
2826 cur->next = xzalloc(sizeof(*cur));
2833 cur->flg_export = 1;
2834 if (cur->flg_export)
2835 return putenv(cur->varstr);
2839 static void unset_local_var(const char *name)
2841 struct variable *cur;
2842 struct variable *prev = prev; /* for gcc */
2847 name_len = strlen(name);
2850 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2851 if (cur->flg_read_only) {
2852 bb_error_msg("%s: readonly variable", name);
2855 /* prev is ok to use here because 1st variable, HUSH_VERSION,
2856 * is ro, and we cannot reach this code on the 1st pass */
2857 prev->next = cur->next;
2858 unsetenv(cur->varstr);
2869 static int is_assignment(const char *s)
2871 if (!s || !isalpha(*s))
2874 while (isalnum(*s) || *s == '_')
2879 /* the src parameter allows us to peek forward to a possible &n syntax
2880 * for file descriptor duplication, e.g., "2>&1".
2881 * Return code is 0 normally, 1 if a syntax error is detected in src.
2882 * Resource errors (in xmalloc) cause the process to exit */
2883 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2884 struct in_str *input)
2886 struct child_prog *child = ctx->child;
2887 struct redir_struct *redir = child->redirects;
2888 struct redir_struct *last_redir = NULL;
2890 /* Create a new redir_struct and drop it onto the end of the linked list */
2893 redir = redir->next;
2895 redir = xzalloc(sizeof(struct redir_struct));
2896 /* redir->next = NULL; */
2897 /* redir->glob_word = NULL; */
2899 last_redir->next = redir;
2901 child->redirects = redir;
2904 redir->type = style;
2905 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
2907 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2909 /* Check for a '2>&1' type redirect */
2910 redir->dup = redirect_dup_num(input);
2911 if (redir->dup == -2) return 1; /* syntax error */
2912 if (redir->dup != -1) {
2913 /* Erik had a check here that the file descriptor in question
2914 * is legit; I postpone that to "run time"
2915 * A "-" representation of "close me" shows up as a -3 here */
2916 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2918 /* We do _not_ try to open the file that src points to,
2919 * since we need to return and let src be expanded first.
2920 * Set ctx->pending_redirect, so we know what to do at the
2921 * end of the next parsed word. */
2922 ctx->pending_redirect = redir;
2927 static struct pipe *new_pipe(void)
2930 pi = xzalloc(sizeof(struct pipe));
2931 /*pi->num_progs = 0;*/
2932 /*pi->progs = NULL;*/
2933 /*pi->next = NULL;*/
2934 /*pi->followup = 0; invalid */
2936 pi->res_word = RES_NONE;
2940 static void initialize_context(struct p_context *ctx)
2943 ctx->pipe = ctx->list_head = new_pipe();
2944 ctx->pending_redirect = NULL;
2945 ctx->res_w = RES_NONE;
2946 //only ctx->parse_type is not touched... is this intentional?
2949 done_command(ctx); /* creates the memory for working child */
2952 /* normal return is 0
2953 * if a reserved word is found, and processed, return 1
2954 * should handle if, then, elif, else, fi, for, while, until, do, done.
2955 * case, function, and select are obnoxious, save those for later.
2957 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS
2958 static int reserved_word(o_string *dest, struct p_context *ctx)
2960 struct reserved_combo {
2965 /* Mostly a list of accepted follow-up reserved words.
2966 * FLAG_END means we are done with the sequence, and are ready
2967 * to turn the compound list into a command.
2968 * FLAG_START means the word must start a new compound list.
2970 static const struct reserved_combo reserved_list[] = {
2972 { "if", RES_IF, FLAG_THEN | FLAG_START },
2973 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2974 { "elif", RES_ELIF, FLAG_THEN },
2975 { "else", RES_ELSE, FLAG_FI },
2976 { "fi", RES_FI, FLAG_END },
2978 #if ENABLE_HUSH_LOOPS
2979 { "for", RES_FOR, FLAG_IN | FLAG_START },
2980 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2981 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2982 { "in", RES_IN, FLAG_DO },
2983 { "do", RES_DO, FLAG_DONE },
2984 { "done", RES_DONE, FLAG_END }
2988 const struct reserved_combo *r;
2990 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2991 if (strcmp(dest->data, r->literal) != 0)
2993 debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
2994 if (r->flag & FLAG_START) {
2995 struct p_context *new;
2996 debug_printf("push stack\n");
2997 #if ENABLE_HUSH_LOOPS
2998 if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) {
2999 syntax("malformed for"); /* example: 'for if' */
3000 ctx->res_w = RES_SNTX;
3005 new = xmalloc(sizeof(*new));
3006 *new = *ctx; /* physical copy */
3007 initialize_context(ctx);
3009 } else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
3011 ctx->res_w = RES_SNTX;
3015 ctx->res_w = r->code;
3016 ctx->old_flag = r->flag;
3017 if (ctx->old_flag & FLAG_END) {
3018 struct p_context *old;
3019 debug_printf("pop stack\n");
3020 done_pipe(ctx, PIPE_SEQ);
3022 old->child->group = ctx->list_head;
3023 old->child->subshell = 0;
3024 *ctx = *old; /* physical copy */
3033 #define reserved_word(dest, ctx) ((int)0)
3036 /* Normal return is 0.
3037 * Syntax or xglob errors return 1. */
3038 static int done_word(o_string *dest, struct p_context *ctx)
3040 struct child_prog *child = ctx->child;
3041 char ***glob_target;
3044 debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child);
3045 if (dest->length == 0 && !dest->nonnull) {
3046 debug_printf_parse("done_word return 0: true null, ignored\n");
3049 if (ctx->pending_redirect) {
3050 glob_target = &ctx->pending_redirect->glob_word;
3054 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3057 if (!child->argv && (ctx->parse_type & PARSEFLAG_SEMICOLON)) {
3058 debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data);
3059 if (reserved_word(dest, ctx)) {
3060 debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX));
3061 return (ctx->res_w == RES_SNTX);
3064 glob_target = &child->argv;
3066 gr = xglob(dest, glob_target);
3068 debug_printf_parse("done_word return 1: xglob returned %d\n", gr);
3073 if (ctx->pending_redirect) {
3074 /* NB: don't free_strings(ctx->pending_redirect->glob_word) here */
3075 if (ctx->pending_redirect->glob_word
3076 && ctx->pending_redirect->glob_word[0]
3077 && ctx->pending_redirect->glob_word[1]
3079 /* more than one word resulted from globbing redir */
3080 ctx->pending_redirect = NULL;
3081 bb_error_msg("ambiguous redirect");
3082 debug_printf_parse("done_word return 1: ambiguous redirect\n");
3085 ctx->pending_redirect = NULL;
3087 #if ENABLE_HUSH_LOOPS
3088 if (ctx->res_w == RES_FOR) {
3089 done_word(dest, ctx);
3090 done_pipe(ctx, PIPE_SEQ);
3093 debug_printf_parse("done_word return 0\n");
3097 /* The only possible error here is out of memory, in which case
3099 static int done_command(struct p_context *ctx)
3101 /* The child is really already in the pipe structure, so
3102 * advance the pipe counter and make a new, null child. */
3103 struct pipe *pi = ctx->pipe;
3104 struct child_prog *child = ctx->child;
3107 if (child->group == NULL
3108 && child->argv == NULL
3109 && child->redirects == NULL
3111 debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
3112 return pi->num_progs;
3115 debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
3117 debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
3120 /* Only real trickiness here is that the uncommitted
3121 * child structure is not counted in pi->num_progs. */
3122 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
3123 child = &pi->progs[pi->num_progs];
3125 memset(child, 0, sizeof(*child));
3126 /*child->redirects = NULL;*/
3127 /*child->argv = NULL;*/
3128 /*child->is_stopped = 0;*/
3129 /*child->group = NULL;*/
3131 //sp: /*child->sp = 0;*/
3132 //pt: child->parse_type = ctx->parse_type;
3135 /* but ctx->pipe and ctx->list_head remain unchanged */
3137 return pi->num_progs; /* used only for 0/nonzero check */
3140 static int done_pipe(struct p_context *ctx, pipe_style type)
3145 debug_printf_parse("done_pipe entered, followup %d\n", type);
3146 not_null = done_command(ctx); /* implicit closure of previous command */
3147 ctx->pipe->followup = type;
3148 ctx->pipe->res_word = ctx->res_w;
3149 /* Without this check, even just <enter> on command line generates
3150 * tree of three NOPs (!). Which is harmless but annoying.
3151 * IOW: it is safe to do it unconditionally. */
3154 ctx->pipe->next = new_p;
3157 done_command(ctx); /* set up new pipe to accept commands */
3159 debug_printf_parse("done_pipe return 0\n");
3163 /* peek ahead in the in_str to find out if we have a "&n" construct,
3164 * as in "2>&1", that represents duplicating a file descriptor.
3165 * returns either -2 (syntax error), -1 (no &), or the number found.
3167 static int redirect_dup_num(struct in_str *input)
3169 int ch, d = 0, ok = 0;
3171 if (ch != '&') return -1;
3173 b_getch(input); /* get the & */
3177 return -3; /* "-" represents "close me" */
3179 while (isdigit(ch)) {
3180 d = d*10 + (ch-'0');
3187 bb_error_msg("ambiguous redirect");
3191 /* If a redirect is immediately preceded by a number, that number is
3192 * supposed to tell which file descriptor to redirect. This routine
3193 * looks for such preceding numbers. In an ideal world this routine
3194 * needs to handle all the following classes of redirects...
3195 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3196 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3197 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3198 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3199 * A -1 output from this program means no valid number was found, so the
3200 * caller should use the appropriate default for this redirection.
3202 static int redirect_opt_num(o_string *o)
3208 for (num = 0; num < o->length; num++) {
3209 if (!isdigit(*(o->data + num))) {
3213 /* reuse num (and save an int) */
3214 num = atoi(o->data);
3219 #if ENABLE_HUSH_TICK
3220 /* NB: currently disabled on NOMMU */
3221 static FILE *generate_stream_from_list(struct pipe *head)
3224 int pid, channel[2];
3229 bb_perror_msg_and_die("fork");
3230 } else if (pid == 0) {
3232 if (channel[1] != 1) {
3233 dup2(channel[1], 1);
3236 /* Prevent it from trying to handle ctrl-z etc */
3240 /* Process substitution is not considered to be usual
3241 * 'command execution'.
3242 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
3243 /* Not needed, we are relying on it being disabled
3244 * everywhere outside actual command execution. */
3245 /*set_jobctrl_sighandler(SIG_IGN);*/
3246 set_misc_sighandler(SIG_DFL);
3247 _exit(run_list_real(head)); /* leaks memory */
3250 pf = fdopen(channel[0], "r");
3254 /* Return code is exit status of the process that is run. */
3255 static int process_command_subs(o_string *dest, struct p_context *ctx,
3256 struct in_str *input, const char *subst_end)
3258 int retcode, ch, eol_cnt;
3259 o_string result = NULL_O_STRING;
3260 struct p_context inner;
3262 struct in_str pipe_str;
3264 initialize_context(&inner);
3266 /* recursion to generate command */
3267 retcode = parse_stream(&result, &inner, input, subst_end);
3269 return retcode; /* syntax error or EOF */
3270 done_word(&result, &inner);
3271 done_pipe(&inner, PIPE_SEQ);
3274 p = generate_stream_from_list(inner.list_head);
3275 if (p == NULL) return 1;
3276 close_on_exec_on(fileno(p));
3277 setup_file_in_str(&pipe_str, p);
3279 /* now send results of command back into original context */
3281 while ((ch = b_getch(&pipe_str)) != EOF) {
3287 b_addqchr(dest, '\n', dest->o_quote);
3290 b_addqchr(dest, ch, dest->o_quote);
3293 debug_printf("done reading from pipe, pclose()ing\n");
3294 /* This is the step that wait()s for the child. Should be pretty
3295 * safe, since we just read an EOF from its stdout. We could try
3296 * to do better, by using wait(), and keeping track of background jobs
3297 * at the same time. That would be a lot of work, and contrary
3298 * to the KISS philosophy of this program. */
3299 retcode = fclose(p);
3300 free_pipe_list(inner.list_head, 0);
3301 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3306 static int parse_group(o_string *dest, struct p_context *ctx,
3307 struct in_str *input, int ch)
3310 const char *endch = NULL;
3311 struct p_context sub;
3312 struct child_prog *child = ctx->child;
3314 debug_printf_parse("parse_group entered\n");
3317 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3320 initialize_context(&sub);
3324 child->subshell = 1;
3326 rcode = parse_stream(dest, &sub, input, endch);
3328 done_word(dest, &sub); /* finish off the final word in the subcontext */
3329 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3330 child->group = sub.list_head;
3332 debug_printf_parse("parse_group return %d\n", rcode);
3334 /* child remains "open", available for possible redirects */
3337 /* Basically useful version until someone wants to get fancier,
3338 * see the bash man page under "Parameter Expansion" */
3339 static const char *lookup_param(const char *src)
3341 struct variable *var = get_local_var(src);
3343 return strchr(var->varstr, '=') + 1;
3347 /* return code: 0 for OK, 1 for syntax error */
3348 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
3350 int ch = b_peek(input); /* first character after the $ */
3351 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3353 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3355 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3356 //sp: ctx->child->sp++;
3358 debug_printf_parse(": '%c'\n", ch);
3360 b_addchr(dest, ch | quote_mask);
3363 if (!isalnum(ch) && ch != '_')
3366 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3367 } else if (isdigit(ch)) {
3369 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3370 //sp: ctx->child->sp++;
3371 debug_printf_parse(": '%c'\n", ch);
3373 b_addchr(dest, ch | quote_mask);
3374 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3375 } else switch (ch) {
3377 case '!': /* last bg pid */
3378 case '?': /* last exit code */
3379 case '#': /* number of args */
3380 case '*': /* args */
3381 case '@': /* args */
3382 goto make_one_char_var;
3384 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3385 //sp: ctx->child->sp++;
3387 /* XXX maybe someone will try to escape the '}' */
3389 ch = b_getch(input);
3392 if (!isalnum(ch) && ch != '_') {
3393 syntax("unterminated ${name}");
3394 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3397 debug_printf_parse(": '%c'\n", ch);
3398 b_addchr(dest, ch | quote_mask);
3401 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3403 #if ENABLE_HUSH_TICK
3406 process_command_subs(dest, ctx, input, ")");
3411 /* still unhandled, but should be eventually */
3412 bb_error_msg("unhandled syntax: $%c", ch);
3416 b_addqchr(dest, '$', dest->o_quote);
3418 debug_printf_parse("handle_dollar return 0\n");
3422 /* return code is 0 for normal exit, 1 for syntax error */
3423 static int parse_stream(o_string *dest, struct p_context *ctx,
3424 struct in_str *input, const char *end_trigger)
3428 redir_type redir_style;
3431 /* Only double-quote state is handled in the state variable dest->o_quote.
3432 * A single-quote triggers a bypass of the main loop until its mate is
3433 * found. When recursing, quote state is passed in via dest->o_quote. */
3435 debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
3440 ch = b_getch(input);
3444 next = b_peek(input);
3446 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
3447 ch, ch, m, dest->o_quote);
3448 if (m == CHAR_ORDINARY
3449 || (m != CHAR_SPECIAL && dest->o_quote)
3452 syntax("unterminated \"");
3453 debug_printf_parse("parse_stream return 1: unterminated \"\n");
3456 b_addqchr(dest, ch, dest->o_quote);
3459 if (m == CHAR_IFS) {
3460 if (done_word(dest, ctx)) {
3461 debug_printf_parse("parse_stream return 1: done_word!=0\n");
3466 /* If we aren't performing a substitution, treat
3467 * a newline as a command separator.
3468 * [why we don't handle it exactly like ';'? --vda] */
3469 if (end_trigger && ch == '\n') {
3470 done_pipe(ctx, PIPE_SEQ);
3473 if ((end_trigger && strchr(end_trigger, ch))
3474 && !dest->o_quote && ctx->res_w == RES_NONE
3476 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
3483 if (dest->length == 0 && !dest->o_quote) {
3486 if (ch == EOF || ch == '\n')
3491 b_addqchr(dest, ch, dest->o_quote);
3497 debug_printf_parse("parse_stream return 1: \\<eof>\n");
3500 b_addqchr(dest, '\\', dest->o_quote);
3501 b_addqchr(dest, b_getch(input), dest->o_quote);
3504 if (handle_dollar(dest, ctx, input) != 0) {
3505 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
3512 ch = b_getch(input);
3513 if (ch == EOF || ch == '\'')
3518 syntax("unterminated '");
3519 debug_printf_parse("parse_stream return 1: unterminated '\n");
3525 dest->o_quote ^= 1; /* invert */
3527 #if ENABLE_HUSH_TICK
3529 process_command_subs(dest, ctx, input, "`");
3533 redir_fd = redirect_opt_num(dest);
3534 done_word(dest, ctx);
3535 redir_style = REDIRECT_OVERWRITE;
3537 redir_style = REDIRECT_APPEND;
3541 else if (next == '(') {
3542 syntax(">(process) not supported");
3543 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
3547 setup_redirect(ctx, redir_fd, redir_style, input);
3550 redir_fd = redirect_opt_num(dest);
3551 done_word(dest, ctx);
3552 redir_style = REDIRECT_INPUT;
3554 redir_style = REDIRECT_HEREIS;
3556 } else if (next == '>') {
3557 redir_style = REDIRECT_IO;
3561 else if (next == '(') {
3562 syntax("<(process) not supported");
3563 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
3567 setup_redirect(ctx, redir_fd, redir_style, input);
3570 done_word(dest, ctx);
3571 done_pipe(ctx, PIPE_SEQ);
3574 done_word(dest, ctx);
3577 done_pipe(ctx, PIPE_AND);
3579 done_pipe(ctx, PIPE_BG);
3583 done_word(dest, ctx);
3586 done_pipe(ctx, PIPE_OR);
3588 /* we could pick up a file descriptor choice here
3589 * with redirect_opt_num(), but bash doesn't do it.
3590 * "echo foo 2| cat" yields "foo 2". */
3596 if (parse_group(dest, ctx, input, ch) != 0) {
3597 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
3603 syntax("unexpected }"); /* Proper use of this character is caught by end_trigger */
3604 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
3607 if (ENABLE_HUSH_DEBUG)
3608 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
3611 /* Complain if quote? No, maybe we just finished a command substitution
3612 * that was quoted. Example:
3613 * $ echo "`cat foo` plus more"
3614 * and we just got the EOF generated by the subshell that ran "cat foo"
3615 * The only real complaint is if we got an EOF when end_trigger != NULL,
3616 * that is, we were really supposed to get end_trigger, and never got
3617 * one before the EOF. Can't use the standard "syntax error" return code,
3618 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3619 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
3625 static void set_in_charmap(const char *set, int code)
3628 charmap[(unsigned char)*set++] = code;
3631 static void update_charmap(void)
3633 /* char *ifs and char charmap[256] are both globals. */
3634 ifs = getenv("IFS");
3637 /* Precompute a list of 'flow through' behavior so it can be treated
3638 * quickly up front. Computation is necessary because of IFS.
3639 * Special case handling of IFS == " \t\n" is not implemented.
3640 * The charmap[] array only really needs two bits each,
3641 * and on most machines that would be faster (reduced L1 cache use).
3643 memset(charmap, CHAR_ORDINARY, sizeof(charmap));
3644 #if ENABLE_HUSH_TICK
3645 set_in_charmap("\\$\"`", CHAR_SPECIAL);
3647 set_in_charmap("\\$\"", CHAR_SPECIAL);
3649 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
3650 set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */
3653 /* most recursion does not come through here, the exception is
3654 * from builtin_source() and builtin_eval() */
3655 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
3657 struct p_context ctx;
3658 o_string temp = NULL_O_STRING;
3661 ctx.parse_type = parse_flag;
3662 initialize_context(&ctx);
3664 if (!(parse_flag & PARSEFLAG_SEMICOLON) || (parse_flag & PARSEFLAG_REPARSING))
3665 set_in_charmap(";$&|", CHAR_ORDINARY);
3666 #if ENABLE_HUSH_INTERACTIVE
3667 inp->promptmode = 0; /* PS1 */
3669 /* We will stop & execute after each ';' or '\n'.
3670 * Example: "sleep 9999; echo TEST" + ctrl-C:
3671 * TEST should be printed */
3672 rcode = parse_stream(&temp, &ctx, inp, ";\n");
3673 if (rcode != 1 && ctx.old_flag != 0) {
3676 if (rcode != 1 && ctx.old_flag == 0) {
3677 done_word(&temp, &ctx);
3678 done_pipe(&ctx, PIPE_SEQ);
3679 debug_print_tree(ctx.list_head, 0);
3680 debug_printf_exec("parse_stream_outer: run_list\n");
3681 run_list(ctx.list_head);
3683 if (ctx.old_flag != 0) {
3690 free_pipe_list(ctx.list_head, 0);
3693 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
3697 static int parse_and_run_string(const char *s, int parse_flag)
3699 struct in_str input;
3700 setup_string_in_str(&input, s);
3701 return parse_and_run_stream(&input, parse_flag);
3704 static int parse_and_run_file(FILE *f)
3707 struct in_str input;
3708 setup_file_in_str(&input, f);
3709 rcode = parse_and_run_stream(&input, PARSEFLAG_SEMICOLON);
3714 /* Make sure we have a controlling tty. If we get started under a job
3715 * aware app (like bash for example), make sure we are now in charge so
3716 * we don't fight over who gets the foreground */
3717 static void setup_job_control(void)
3721 saved_task_pgrp = shell_pgrp = getpgrp();
3722 debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
3723 close_on_exec_on(interactive_fd);
3725 /* If we were ran as 'hush &',
3726 * sleep until we are in the foreground. */
3727 while (tcgetpgrp(interactive_fd) != shell_pgrp) {
3728 /* Send TTIN to ourself (should stop us) */
3729 kill(- shell_pgrp, SIGTTIN);
3730 shell_pgrp = getpgrp();
3733 /* Ignore job-control and misc signals. */
3734 set_jobctrl_sighandler(SIG_IGN);
3735 set_misc_sighandler(SIG_IGN);
3736 //huh? signal(SIGCHLD, SIG_IGN);
3738 /* We _must_ restore tty pgrp on fatal signals */
3739 set_fatal_sighandler(sigexit);
3741 /* Put ourselves in our own process group. */
3742 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
3743 /* Grab control of the terminal. */
3744 tcsetpgrp(interactive_fd, getpid());
3748 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3749 int hush_main(int argc, char **argv)
3751 static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
3752 static const struct variable const_shell_ver = {
3754 .varstr = (char*)version_str,
3755 .max_len = 1, /* 0 can provoke free(name) */
3763 struct variable *cur_var;
3765 PTR_TO_GLOBALS = xzalloc(sizeof(G));
3767 /* Deal with HUSH_VERSION */
3768 shell_ver = const_shell_ver; /* copying struct here */
3769 top_var = &shell_ver;
3770 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
3771 /* Initialize our shell local variables with the values
3772 * currently living in the environment */
3776 char *value = strchr(*e, '=');
3777 if (value) { /* paranoia */
3778 cur_var->next = xzalloc(sizeof(*cur_var));
3779 cur_var = cur_var->next;
3780 cur_var->varstr = *e;
3781 cur_var->max_len = strlen(*e);
3782 cur_var->flg_export = 1;
3786 putenv((char *)version_str); /* reinstate HUSH_VERSION */
3788 #if ENABLE_FEATURE_EDITING
3789 line_input_state = new_line_input_t(FOR_SHELL);
3791 /* XXX what should these be while sourcing /etc/profile? */
3794 /* Initialize some more globals to non-zero values */
3796 #if ENABLE_HUSH_INTERACTIVE
3797 #if ENABLE_FEATURE_EDITING
3798 cmdedit_set_initial_prompt();
3803 if (EXIT_SUCCESS) /* otherwise is already done */
3804 last_return_code = EXIT_SUCCESS;
3806 if (argv[0] && argv[0][0] == '-') {
3807 debug_printf("sourcing /etc/profile\n");
3808 input = fopen("/etc/profile", "r");
3809 if (input != NULL) {
3810 close_on_exec_on(fileno(input));
3811 parse_and_run_file(input);
3817 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3820 global_argv = argv + optind;
3821 global_argc = argc - optind;
3822 opt = parse_and_run_string(optarg, PARSEFLAG_SEMICOLON);
3825 /* Well, we cannot just declare interactiveness,
3826 * we have to have some stuff (ctty, etc) */
3827 /* interactive_fd++; */
3834 fprintf(stderr, "Usage: sh [FILE]...\n"
3835 " or: sh -c command [args]...\n\n");
3843 /* A shell is interactive if the '-i' flag was given, or if all of
3844 * the following conditions are met:
3846 * no arguments remaining or the -s flag given
3847 * standard input is a terminal
3848 * standard output is a terminal
3849 * Refer to Posix.2, the description of the 'sh' utility. */
3850 if (argv[optind] == NULL && input == stdin
3851 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3853 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
3854 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
3855 if (saved_tty_pgrp >= 0) {
3856 /* try to dup to high fd#, >= 255 */
3857 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3858 if (interactive_fd < 0) {
3859 /* try to dup to any fd */
3860 interactive_fd = dup(STDIN_FILENO);
3861 if (interactive_fd < 0)
3865 // TODO: track & disallow any attempts of user
3866 // to (inadvertently) close/redirect it
3869 debug_printf("interactive_fd=%d\n", interactive_fd);
3870 if (interactive_fd) {
3871 /* Looks like they want an interactive shell */
3872 setup_job_control();
3873 /* Make xfuncs do cleanup on exit */
3874 die_sleep = -1; /* flag */
3875 // FIXME: should we reset die_sleep = 0 whereever we fork?
3876 if (setjmp(die_jmp)) {
3877 /* xfunc has failed! die die die */
3878 hush_exit(xfunc_error_retval);
3880 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
3881 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
3882 printf("Enter 'help' for a list of built-in commands.\n\n");
3885 #elif ENABLE_HUSH_INTERACTIVE
3886 /* no job control compiled, only prompt/line editing */
3887 if (argv[optind] == NULL && input == stdin
3888 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3890 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3891 if (interactive_fd < 0) {
3892 /* try to dup to any fd */
3893 interactive_fd = dup(STDIN_FILENO);
3894 if (interactive_fd < 0)
3902 if (argv[optind] == NULL) {
3903 opt = parse_and_run_file(stdin);
3907 debug_printf("\nrunning script '%s'\n", argv[optind]);
3908 global_argv = argv + optind;
3909 global_argc = argc - optind;
3910 input = xfopen(argv[optind], "r");
3911 opt = parse_and_run_file(input);
3915 #if ENABLE_FEATURE_CLEAN_UP
3917 if (cwd != bb_msg_unknown)
3919 cur_var = top_var->next;
3921 struct variable *tmp = cur_var;
3922 if (!cur_var->max_len)
3923 free(cur_var->varstr);
3924 cur_var = cur_var->next;
3928 hush_exit(opt ? opt : last_return_code);
3933 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3934 int lash_main(int argc, char **argv)
3936 //bb_error_msg("lash is deprecated, please use hush instead");
3937 return hush_main(argc, argv);