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?)
40 * $@ (those sure look like weird quoting rules)
42 * ! negation operator for pipes
43 * &> and >& redirection of stdout+stderr
46 * fancy forms of Parameter Expansion
48 * Arithmetic Expansion
49 * <(list) and >(list) Process Substitution
50 * reserved words: case, esac, select, function
51 * Here Documents ( << word )
54 * job handling woefully incomplete and buggy (improved --vda)
55 * reserved word execution woefully incomplete and buggy
57 * port selected bugfixes from post-0.49 busybox lash - done?
58 * finish implementing reserved words: for, while, until, do, done
59 * change { and } from special chars to reserved words
60 * builtins: break, continue, eval, return, set, trap, ulimit
62 * handle children going into background
63 * clean up recognition of null pipes
64 * check setting of global_argc and global_argv
65 * control-C handling, probably with longjmp
66 * follow IFS rules more precisely, including update semantics
67 * figure out what to do with backslash-newline
68 * explain why we use signal instead of sigaction
69 * propagate syntax errors, die on resource errors?
70 * continuation lines, both explicit and implicit - done?
71 * memory leak finding and plugging - done?
72 * more testing, especially quoting rules and redirection
73 * document how quoting rules not precisely followed for variable assignments
74 * maybe change map[] to use 2-bit entries
75 * (eventually) remove all the printf's
77 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
81 #include <glob.h> /* glob, of course */
82 #include <getopt.h> /* should be pretty obvious */
84 /* #include <dmalloc.h> */
86 /* Finer-grained debug switch */
87 //#define DEBUG_SHELL_JOBS
89 #if !ENABLE_HUSH_INTERACTIVE
90 #undef ENABLE_FEATURE_EDITING
91 #define ENABLE_FEATURE_EDITING 0
92 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
93 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
96 #define SPECIAL_VAR_SYMBOL 03
97 #define FLAG_EXIT_FROM_LOOP 1
98 #define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
99 #define FLAG_REPARSING (1 << 2) /* >=2nd pass */
103 REDIRECT_OVERWRITE = 2,
109 /* The descrip member of this structure is only used to make debugging
111 static const struct {
117 { O_RDONLY, 0, "<" },
118 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
119 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
120 { O_RDONLY, -1, "<<" },
131 /* might eventually control execution */
149 FLAG_END = (1 << RES_NONE ),
150 FLAG_IF = (1 << RES_IF ),
151 FLAG_THEN = (1 << RES_THEN ),
152 FLAG_ELIF = (1 << RES_ELIF ),
153 FLAG_ELSE = (1 << RES_ELSE ),
154 FLAG_FI = (1 << RES_FI ),
155 FLAG_FOR = (1 << RES_FOR ),
156 FLAG_WHILE = (1 << RES_WHILE),
157 FLAG_UNTIL = (1 << RES_UNTIL),
158 FLAG_DO = (1 << RES_DO ),
159 FLAG_DONE = (1 << RES_DONE ),
160 FLAG_IN = (1 << RES_IN ),
161 FLAG_START = (1 << RES_XXXX ),
164 /* This holds pointers to the various results of parsing */
166 struct child_prog *child;
167 struct pipe *list_head;
169 struct redir_struct *pending_redirect;
171 int old_flag; /* for figuring out valid reserved words */
172 struct p_context *stack;
173 int type; /* define type of parser : ";$" common or special symbol */
174 /* How about quoting status? */
177 struct redir_struct {
178 struct redir_struct *next; /* pointer to the next redirect in the list */
179 redir_type type; /* type of redirection */
180 int fd; /* file descriptor being redirected */
181 int dup; /* -1, or file descriptor being duplicated */
182 glob_t word; /* *word.gl_pathv is the filename */
186 pid_t pid; /* 0 if exited */
187 char **argv; /* program name and arguments */
188 struct pipe *group; /* if non-NULL, first in group or subshell */
189 int subshell; /* flag, non-zero if group must be forked */
190 struct redir_struct *redirects; /* I/O redirections */
191 glob_t glob_result; /* result of parameter globbing */
192 int is_stopped; /* is the program currently running? */
193 struct pipe *family; /* pointer back to the child's parent pipe */
194 int sp; /* number of SPECIAL_VAR_SYMBOL */
200 int num_progs; /* total number of programs in job */
201 int running_progs; /* number of programs running (not exited) */
202 char *cmdbuf; /* buffer various argv's point into */
204 int jobid; /* job number */
205 char *cmdtext; /* name of job */
206 pid_t pgrp; /* process group ID for the job */
208 struct child_prog *progs; /* array of commands in pipe */
209 int stopped_progs; /* number of programs alive, but stopped */
210 int job_context; /* bitmask defining current context */
211 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
212 reserved_style r_mode; /* supports if, for, while, until */
216 struct close_me *next;
221 struct variables *next;
228 /* globals, connect us to the outside world
229 * the first three support $?, $#, and $1 */
230 static char **global_argv;
231 static int global_argc;
232 static int last_return_code;
233 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
235 /* "globals" within this file */
236 static const char *ifs;
237 static unsigned char map[256];
238 static int fake_mode;
239 static struct close_me *close_me_head;
240 static const char *cwd;
241 static unsigned last_bg_pid;
242 #if !ENABLE_HUSH_INTERACTIVE
243 enum { interactive_fd = 0 };
245 /* 'interactive_fd' is a fd# open to ctty, if we have one
246 * _AND_ if we decided to mess with job control */
247 static int interactive_fd;
249 static pid_t saved_task_pgrp;
250 static pid_t saved_tty_pgrp;
251 static int last_jobid;
252 static struct pipe *job_list;
254 static const char *PS1;
255 static const char *PS2;
258 static struct variables shell_ver = { NULL, "HUSH_VERSION", "0.01", 1, 1 };
259 static struct variables *top_vars = &shell_ver;
271 #define NULL_O_STRING {NULL,0,0,0,0}
272 /* used for initialization:
273 o_string foo = NULL_O_STRING; */
275 /* I can almost use ordinary FILE *. Is open_memstream() universally
276 * available? Where is it documented? */
280 #if ENABLE_HUSH_INTERACTIVE
285 int (*get) (struct in_str *);
286 int (*peek) (struct in_str *);
288 #define b_getch(input) ((input)->get(input))
289 #define b_peek(input) ((input)->peek(input))
291 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
293 struct built_in_command {
294 const char *cmd; /* name */
295 const char *descr; /* description */
296 int (*function) (char **argv); /* function ptr */
299 /* belongs in busybox.h */
300 static int max(int a, int b)
302 return (a > b) ? a : b;
306 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
307 /* broken, of course, but OK for testing */
308 static char *indenter(int i)
310 static char blanks[] = " ";
311 return &blanks[sizeof(blanks) - i - 1];
314 #define debug_printf(...) do {} while (0)
317 #ifdef DEBUG_SHELL_JOBS
318 #define debug_jobs_printf(...) fprintf(stderr, __VA_ARGS__)
320 #define debug_jobs_printf(...) do {} while (0)
323 #define final_printf debug_printf
325 static void __syntax(int line)
327 bb_error_msg("syntax error hush.c:%d", line);
329 #define syntax() __syntax(__LINE__)
331 /* Index of subroutines: */
332 /* function prototypes for builtins */
333 static int builtin_cd(char **argv);
334 static int builtin_env(char **argv);
335 static int builtin_eval(char **argv);
336 static int builtin_exec(char **argv);
337 static int builtin_exit(char **argv);
338 static int builtin_export(char **argv);
340 static int builtin_fg_bg(char **argv);
341 static int builtin_jobs(char **argv);
343 static int builtin_help(char **argv);
344 static int builtin_pwd(char **argv);
345 static int builtin_read(char **argv);
346 static int builtin_set(char **argv);
347 static int builtin_shift(char **argv);
348 static int builtin_source(char **argv);
349 static int builtin_umask(char **argv);
350 static int builtin_unset(char **argv);
351 static int builtin_not_written(char **argv);
352 /* o_string manipulation: */
353 static int b_check_space(o_string *o, int len);
354 static int b_addchr(o_string *o, int ch);
355 static void b_reset(o_string *o);
356 static int b_addqchr(o_string *o, int ch, int quote);
357 static int b_adduint(o_string *o, unsigned i);
358 /* in_str manipulations: */
359 static int static_get(struct in_str *i);
360 static int static_peek(struct in_str *i);
361 static int file_get(struct in_str *i);
362 static int file_peek(struct in_str *i);
363 static void setup_file_in_str(struct in_str *i, FILE *f);
364 static void setup_string_in_str(struct in_str *i, const char *s);
365 /* close_me manipulations: */
366 static void mark_open(int fd);
367 static void mark_closed(int fd);
368 static void close_all(void);
369 /* "run" the final data structures: */
370 static int free_pipe_list(struct pipe *head, int indent);
371 static int free_pipe(struct pipe *pi, int indent);
372 /* really run the final data structures: */
373 static int setup_redirects(struct child_prog *prog, int squirrel[]);
374 static int run_list_real(struct pipe *pi);
375 static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN;
376 static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
377 static int run_pipe_real(struct pipe *pi);
378 /* extended glob support: */
379 static int globhack(const char *src, int flags, glob_t *pglob);
380 static int glob_needed(const char *s);
381 static int xglob(o_string *dest, int flags, glob_t *pglob);
382 /* variable assignment: */
383 static int is_assignment(const char *s);
384 /* data structure manipulation: */
385 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
386 static void initialize_context(struct p_context *ctx);
387 static int done_word(o_string *dest, struct p_context *ctx);
388 static int done_command(struct p_context *ctx);
389 static int done_pipe(struct p_context *ctx, pipe_style type);
390 /* primary string parsing: */
391 static int redirect_dup_num(struct in_str *input);
392 static int redirect_opt_num(o_string *o);
393 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
394 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
395 static const char *lookup_param(const char *src);
396 static char *make_string(char **inp);
397 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
398 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
399 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
401 static int parse_stream_outer(struct in_str *inp, int flag);
402 static int parse_string_outer(const char *s, int flag);
403 static int parse_file_outer(FILE *f);
404 /* job management: */
405 static int checkjobs(struct pipe* fg_pipe);
407 static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
408 static void insert_bg_job(struct pipe *pi);
409 static void remove_bg_job(struct pipe *pi);
410 static void delete_finished_bg_job(struct pipe *pi);
412 int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
414 /* local variable support */
415 static char **make_list_in(char **inp, char *name);
416 static char *insert_var_value(char *inp);
417 static const char *get_local_var(const char *var);
418 static int set_local_var(const char *s, int flg_export);
419 static void unset_local_var(const char *name);
421 /* Table of built-in functions. They can be forked or not, depending on
422 * context: within pipes, they fork. As simple commands, they do not.
423 * When used in non-forking context, they can change global variables
424 * in the parent shell process. If forked, of course they cannot.
425 * For example, 'unset foo | whatever' will parse and run, but foo will
426 * still be set at the end. */
427 static const struct built_in_command bltins[] = {
429 { "bg", "Resume a job in the background", builtin_fg_bg },
431 { "break", "Exit for, while or until loop", builtin_not_written },
432 { "cd", "Change working directory", builtin_cd },
433 { "continue", "Continue for, while or until loop", builtin_not_written },
434 { "env", "Print all environment variables", builtin_env },
435 { "eval", "Construct and run shell command", builtin_eval },
436 { "exec", "Exec command, replacing this shell with the exec'd process",
438 { "exit", "Exit from shell()", builtin_exit },
439 { "export", "Set environment variable", builtin_export },
441 { "fg", "Bring job into the foreground", builtin_fg_bg },
442 { "jobs", "Lists the active jobs", builtin_jobs },
444 { "pwd", "Print current directory", builtin_pwd },
445 { "read", "Input environment variable", builtin_read },
446 { "return", "Return from a function", builtin_not_written },
447 { "set", "Set/unset shell local variables", builtin_set },
448 { "shift", "Shift positional parameters", builtin_shift },
449 { "trap", "Trap signals", builtin_not_written },
450 { "ulimit","Controls resource limits", builtin_not_written },
451 { "umask","Sets file creation mask", builtin_umask },
452 { "unset", "Unset environment variable", builtin_unset },
453 { ".", "Source-in and run commands in a file", builtin_source },
454 { "help", "List shell built-in commands", builtin_help },
460 #if ENABLE_FEATURE_SH_STANDALONE
462 static void signal_SA_RESTART(int sig, void (*handler)(int))
465 sa.sa_handler = handler;
466 sa.sa_flags = SA_RESTART;
467 sigemptyset(&sa.sa_mask);
468 sigaction(sig, &sa, NULL);
472 /* Signals are grouped, we handle them in batches */
473 static void set_fatal_sighandler(void (*handler)(int))
475 signal(SIGILL , handler);
476 signal(SIGTRAP, handler);
477 signal(SIGABRT, handler);
478 signal(SIGFPE , handler);
479 signal(SIGBUS , handler);
480 signal(SIGSEGV, handler);
481 /* bash 3.2 seems to handle these just like 'fatal' ones */
482 signal(SIGHUP , handler);
483 signal(SIGPIPE, handler);
484 signal(SIGALRM, handler);
486 static void set_jobctrl_sighandler(void (*handler)(int))
488 signal(SIGTSTP, handler);
489 signal(SIGTTIN, handler);
490 signal(SIGTTOU, handler);
492 static void set_misc_sighandler(void (*handler)(int))
494 signal(SIGINT , handler);
495 signal(SIGQUIT, handler);
496 signal(SIGTERM, handler);
498 /* SIGCHLD is special and handled separately */
500 #if ENABLE_FEATURE_SH_STANDALONE
501 static void set_every_sighandler(void (*handler)(int))
503 set_fatal_sighandler(handler);
504 set_jobctrl_sighandler(handler);
505 set_misc_sighandler(handler);
506 signal(SIGCHLD, handler);
509 static struct pipe *nofork_pipe;
510 struct nofork_save_area nofork_save;
511 static sigjmp_buf nofork_jb;
513 static void handler_ctrl_c(int sig)
515 debug_jobs_printf("got sig %d\n", sig);
516 // as usual we can have all kinds of nasty problems with leaked malloc data here
517 siglongjmp(nofork_jb, 1);
520 static void handler_ctrl_z(int sig)
524 debug_jobs_printf("got tty sig %d\n", sig);
526 if (pid < 0) /* can't fork. Pretend there were no Ctrl-Z */
528 debug_jobs_printf("bg'ing nofork\n");
529 nofork_save.saved = 0; /* flag the fact that Ctrl-Z was handled */
530 nofork_pipe->running_progs = 1;
531 nofork_pipe->stopped_progs = 0;
532 if (!pid) { /* child */
533 debug_jobs_printf("setting pgrp for child\n");
535 set_every_sighandler(SIG_DFL);
536 raise(SIGTSTP); /* resend TSTP so that child will be stopped */
537 debug_jobs_printf("returning to child\n");
538 /* return to nofork, it will eventually exit now,
539 * not return back to shell */
543 /* finish filling up pipe info */
544 nofork_pipe->pgrp = pid; /* child is in its own pgrp */
545 nofork_pipe->progs[0].pid = pid;
546 nofork_pipe->running_progs = 1;
547 nofork_pipe->stopped_progs = 0;
548 /* parent needs to longjmp out of running nofork.
549 * we will "return" exitcode 0, with child put in background */
550 // as usual we can have all kinds of nasty problems with leaked malloc data here
551 siglongjmp(nofork_jb, 1);
556 /* Restores tty foreground process group, and exits.
557 * May be called as signal handler for fatal signal
558 * (will faithfully resend signal to itself, producing correct exit state)
559 * or called directly with -EXITCODE.
560 * We also call it if xfunc is exiting. */
561 static void sigexit(int sig) ATTRIBUTE_NORETURN;
562 static void sigexit(int sig)
566 /* Disable all signals: job control, SIGPIPE, etc. */
567 sigfillset(&block_all);
568 sigprocmask(SIG_SETMASK, &block_all, NULL);
571 tcsetpgrp(interactive_fd, saved_tty_pgrp);
573 /* Not a signal, just exit */
577 /* Enable only this sig and kill ourself with it */
578 signal(sig, SIG_DFL);
579 sigdelset(&block_all, sig);
580 sigprocmask(SIG_SETMASK, &block_all, NULL);
582 _exit(1); /* Should not reach it */
585 /* Restores tty foreground process group, and exits. */
586 static void hush_exit(int exitcode) ATTRIBUTE_NORETURN;
587 static void hush_exit(int exitcode)
589 fflush(NULL); /* flush all streams */
590 sigexit(- (exitcode & 0xff));
593 #else /* !INTERACTIVE */
595 #define set_fatal_sighandler(handler) ((void)0)
596 #define set_jobctrl_sighandler(handler) ((void)0)
597 #define set_misc_sighandler(handler) ((void)0)
598 #define hush_exit(e) exit(-(e))
600 #endif /* INTERACTIVE */
603 static const char *set_cwd(void)
605 if (cwd == bb_msg_unknown)
606 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
607 cwd = xrealloc_getcwd_or_warn((char *)cwd);
609 cwd = bb_msg_unknown;
613 /* built-in 'eval' handler */
614 static int builtin_eval(char **argv)
617 int rcode = EXIT_SUCCESS;
620 str = make_string(argv + 1);
621 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
622 FLAG_PARSE_SEMICOLON);
624 rcode = last_return_code;
629 /* built-in 'cd <path>' handler */
630 static int builtin_cd(char **argv)
634 newdir = getenv("HOME");
638 printf("cd: %s: %s\n", newdir, strerror(errno));
645 /* built-in 'env' handler */
646 static int builtin_env(char **argv ATTRIBUTE_UNUSED)
648 /* TODO: call env applet's code instead */
658 /* built-in 'exec' handler */
659 static int builtin_exec(char **argv)
662 return EXIT_SUCCESS; /* Really? */
663 pseudo_exec_argv(argv + 1);
667 /* built-in 'exit' handler */
668 static int builtin_exit(char **argv)
670 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
671 //puts("exit"); /* bash does it */
674 hush_exit(last_return_code);
675 /* mimic bash: exit 123abc == exit 255 + error msg */
676 xfunc_error_retval = 255;
677 /* bash: exit -2 == exit 254, no error msg */
678 hush_exit(xatoi(argv[1]));
681 /* built-in 'export VAR=value' handler */
682 static int builtin_export(char **argv)
685 char *name = argv[1];
688 return builtin_env(argv);
694 const char *value = strchr(name, '=');
698 /* They are exporting something without an =VALUE */
700 value = get_local_var(name);
702 size_t ln = strlen(name);
704 tmp = realloc(name, ln+strlen(value)+2);
708 sprintf(tmp+ln, "=%s", value);
712 /* bash does not return an error when trying to export
713 * an undefined variable. Do likewise. */
719 bb_perror_msg("export");
721 res = set_local_var(name, 1);
729 /* built-in 'fg' and 'bg' handler */
730 static int builtin_fg_bg(char **argv)
737 /* If they gave us no args, assume they want the last backgrounded task */
739 for (pi = job_list; pi; pi = pi->next) {
740 if (pi->jobid == last_jobid) {
744 bb_error_msg("%s: no current job", argv[0]);
747 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
748 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
751 for (pi = job_list; pi; pi = pi->next) {
752 if (pi->jobid == jobnum) {
756 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
759 // TODO: bash prints a string representation
760 // of job being foregrounded (like "sleep 1 | cat")
761 if (*argv[0] == 'f') {
762 /* Put the job into the foreground. */
763 tcsetpgrp(interactive_fd, pi->pgrp);
766 /* Restart the processes in the job */
767 debug_jobs_printf("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
768 for (i = 0; i < pi->num_progs; i++) {
769 debug_jobs_printf("reviving pid %d\n", pi->progs[i].pid);
770 pi->progs[i].is_stopped = 0;
772 pi->stopped_progs = 0;
774 i = kill(- pi->pgrp, SIGCONT);
776 if (errno == ESRCH) {
777 delete_finished_bg_job(pi);
780 bb_perror_msg("kill (SIGCONT)");
784 if (*argv[0] == 'f') {
786 return checkjobs_and_fg_shell(pi);
792 /* built-in 'help' handler */
793 static int builtin_help(char **argv ATTRIBUTE_UNUSED)
795 const struct built_in_command *x;
797 printf("\nBuilt-in commands:\n");
798 printf("-------------------\n");
799 for (x = bltins; x->cmd; x++) {
800 if (x->descr == NULL)
802 printf("%s\t%s\n", x->cmd, x->descr);
809 /* built-in 'jobs' handler */
810 static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
813 const char *status_string;
815 for (job = job_list; job; job = job->next) {
816 if (job->running_progs == job->stopped_progs)
817 status_string = "Stopped";
819 status_string = "Running";
821 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
827 /* built-in 'pwd' handler */
828 static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
834 /* built-in 'read VAR' handler */
835 static int builtin_read(char **argv)
843 string[0] = '\0'; /* In case stdin has only EOF */
845 fgets(string, sizeof(string), stdin);
847 var = malloc(strlen(argv[1]) + strlen(string) + 2);
849 sprintf(var, "%s=%s", argv[1], string);
850 res = set_local_var(var, 0);
854 bb_perror_msg("read");
855 free(var); /* So not move up to avoid breaking errno */
858 do res = getchar(); while (res != '\n' && res != EOF);
862 /* built-in 'set VAR=value' handler */
863 static int builtin_set(char **argv)
865 char *temp = argv[1];
869 for (e = top_vars; e; e = e->next)
870 printf("%s=%s\n", e->name, e->value);
872 set_local_var(temp, 0);
878 /* Built-in 'shift' handler */
879 static int builtin_shift(char **argv)
885 if (n >= 0 && n < global_argc) {
886 /* XXX This probably breaks $0 */
894 /* Built-in '.' handler (read-in and execute commands from file) */
895 static int builtin_source(char **argv)
903 /* XXX search through $PATH is missing */
904 input = fopen(argv[1], "r");
906 bb_error_msg("cannot open '%s'", argv[1]);
910 /* Now run the file */
911 /* XXX argv and argc are broken; need to save old global_argv
912 * (pointer only is OK!) on this stack frame,
913 * set global_argv=argv+1, recurse, and restore. */
914 mark_open(fileno(input));
915 status = parse_file_outer(input);
916 mark_closed(fileno(input));
921 static int builtin_umask(char **argv)
924 const char *arg = argv[1];
927 new_umask = strtoul(arg, &end, 8);
928 if (*end != '\0' || end == arg) {
932 new_umask = umask(0);
933 printf("%.3o\n", (unsigned) new_umask);
939 /* built-in 'unset VAR' handler */
940 static int builtin_unset(char **argv)
942 /* bash returned already true */
943 unset_local_var(argv[1]);
947 static int builtin_not_written(char **argv)
949 printf("builtin_%s not written\n", argv[0]);
953 static int b_check_space(o_string *o, int len)
955 /* It would be easy to drop a more restrictive policy
956 * in here, such as setting a maximum string length */
957 if (o->length + len > o->maxlen) {
958 char *old_data = o->data;
959 /* assert(data == NULL || o->maxlen != 0); */
960 o->maxlen += max(2*len, B_CHUNK);
961 o->data = realloc(o->data, 1 + o->maxlen);
962 if (o->data == NULL) {
966 return o->data == NULL;
969 static int b_addchr(o_string *o, int ch)
971 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
972 if (b_check_space(o, 1))
974 o->data[o->length] = ch;
976 o->data[o->length] = '\0';
980 static void b_reset(o_string *o)
988 static void b_free(o_string *o)
996 /* My analysis of quoting semantics tells me that state information
997 * is associated with a destination, not a source.
999 static int b_addqchr(o_string *o, int ch, int quote)
1001 if (quote && strchr("*?[\\", ch)) {
1003 rc = b_addchr(o, '\\');
1007 return b_addchr(o, ch);
1010 static int b_adduint(o_string *o, unsigned i)
1013 char buf[sizeof(unsigned)*3 + 1];
1015 *(utoa_to_buf(i, buf, sizeof(buf))) = '\0';
1016 /* no escape checking necessary */
1017 do r = b_addchr(o, *p++); while (r == 0 && *p);
1021 static int static_get(struct in_str *i)
1024 if (ch == '\0') return EOF;
1028 static int static_peek(struct in_str *i)
1033 #if ENABLE_HUSH_INTERACTIVE
1034 static void cmdedit_set_initial_prompt(void)
1036 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1039 PS1 = getenv("PS1");
1045 static const char* setup_prompt_string(int promptmode)
1047 const char *prompt_str;
1048 debug_printf("setup_prompt_string %d ", promptmode);
1049 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1050 /* Set up the prompt */
1051 if (promptmode == 1) {
1054 ns = xmalloc(strlen(cwd)+4);
1055 sprintf(ns, "%s %s", cwd, (geteuid() != 0) ? "$ " : "# ");
1062 prompt_str = (promptmode == 1) ? PS1 : PS2;
1064 debug_printf("result %s\n", prompt_str);
1069 #if ENABLE_FEATURE_EDITING
1070 static line_input_t *line_input_state;
1073 #if ENABLE_HUSH_INTERACTIVE
1074 static int get_user_input(struct in_str *i)
1076 static char the_command[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
1079 const char *prompt_str;
1080 prompt_str = setup_prompt_string(i->promptmode);
1081 #if ENABLE_FEATURE_EDITING
1083 ** enable command line editing only while a command line
1084 ** is actually being read; otherwise, we'll end up bequeathing
1085 ** atexit() handlers and other unwanted stuff to our
1086 ** child processes (rob@sysgo.de)
1088 r = read_line_input(prompt_str, the_command, BUFSIZ, line_input_state);
1090 fputs(prompt_str, stdout);
1092 the_command[0] = r = fgetc(i->file);
1093 the_command[1] = '\0';
1097 return r; /* < 0 == EOF. Not meaningful otherwise */
1101 /* This is the magic location that prints prompts
1102 * and gets data back from the user */
1103 static int file_get(struct in_str *i)
1108 /* If there is data waiting, eat it up */
1109 if (i->p && *i->p) {
1112 /* need to double check i->file because we might be doing something
1113 * more complicated by now, like sourcing or substituting. */
1114 #if ENABLE_HUSH_INTERACTIVE
1115 if (interactive_fd && i->__promptme && i->file == stdin) {
1116 while (!i->p || !(interactive_fd && i->p[0])) {
1117 if (get_user_input(i) < 0)
1122 if (i->p && *i->p) {
1128 ch = fgetc(i->file);
1130 debug_printf("b_getch: got a %d\n", ch);
1132 #if ENABLE_HUSH_INTERACTIVE
1139 /* All the callers guarantee this routine will never be
1140 * used right after a newline, so prompting is not needed.
1142 static int file_peek(struct in_str *i)
1144 if (i->p && *i->p) {
1147 i->peek_buf[0] = fgetc(i->file);
1148 i->peek_buf[1] = '\0';
1150 debug_printf("b_peek: got a %d\n", *i->p);
1154 static void setup_file_in_str(struct in_str *i, FILE *f)
1156 i->peek = file_peek;
1158 #if ENABLE_HUSH_INTERACTIVE
1166 static void setup_string_in_str(struct in_str *i, const char *s)
1168 i->peek = static_peek;
1169 i->get = static_get;
1170 #if ENABLE_HUSH_INTERACTIVE
1177 static void mark_open(int fd)
1179 struct close_me *new = xmalloc(sizeof(struct close_me));
1181 new->next = close_me_head;
1182 close_me_head = new;
1185 static void mark_closed(int fd)
1187 struct close_me *tmp;
1188 if (close_me_head == NULL || close_me_head->fd != fd)
1189 bb_error_msg_and_die("corrupt close_me");
1190 tmp = close_me_head;
1191 close_me_head = close_me_head->next;
1195 static void close_all(void)
1198 for (c = close_me_head; c; c = c->next) {
1201 close_me_head = NULL;
1204 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1205 * and stderr if they are redirected. */
1206 static int setup_redirects(struct child_prog *prog, int squirrel[])
1209 struct redir_struct *redir;
1211 for (redir = prog->redirects; redir; redir = redir->next) {
1212 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1213 /* something went wrong in the parse. Pretend it didn't happen */
1216 if (redir->dup == -1) {
1217 mode = redir_table[redir->type].mode;
1218 openfd = open_or_warn(redir->word.gl_pathv[0], mode);
1220 /* this could get lost if stderr has been redirected, but
1221 bash and ash both lose it as well (though zsh doesn't!) */
1225 openfd = redir->dup;
1228 if (openfd != redir->fd) {
1229 if (squirrel && redir->fd < 3) {
1230 squirrel[redir->fd] = dup(redir->fd);
1235 dup2(openfd, redir->fd);
1236 if (redir->dup == -1)
1244 static void restore_redirects(int squirrel[])
1247 for (i = 0; i < 3; i++) {
1250 /* No error checking. I sure wouldn't know what
1251 * to do with an error if I found one! */
1259 /* XXX no exit() here. If you don't exec, use _exit instead.
1260 * The at_exit handlers apparently confuse the calling process,
1261 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
1262 static void pseudo_exec_argv(char **argv)
1266 const struct built_in_command *x;
1268 for (i = 0; is_assignment(argv[i]); i++) {
1269 debug_printf("pid %d environment modification: %s\n",
1271 // FIXME: vfork case??
1272 p = insert_var_value(argv[i]);
1278 /* If a variable is assigned in a forest, and nobody listens,
1279 * was it ever really set?
1281 if (argv[0] == NULL) {
1282 _exit(EXIT_SUCCESS);
1286 * Check if the command matches any of the builtins.
1287 * Depending on context, this might be redundant. But it's
1288 * easier to waste a few CPU cycles than it is to figure out
1289 * if this is one of those cases.
1291 for (x = bltins; x->cmd; x++) {
1292 if (strcmp(argv[0], x->cmd) == 0) {
1293 debug_printf("builtin exec %s\n", argv[0]);
1294 rcode = x->function(argv);
1300 /* Check if the command matches any busybox internal commands
1302 * FIXME: This feature is not 100% safe, since
1303 * BusyBox is not fully reentrant, so we have no guarantee the things
1304 * from the .bss are still zeroed, or that things from .data are still
1305 * at their defaults. We could exec ourself from /proc/self/exe, but I
1306 * really dislike relying on /proc for things. We could exec ourself
1307 * from global_argv[0], but if we are in a chroot, we may not be able
1308 * to find ourself... */
1309 #if ENABLE_FEATURE_SH_STANDALONE
1310 debug_printf("running applet %s\n", argv[0]);
1311 run_applet_and_exit(argv[0], argv);
1312 // is it ok that run_applet_and_exit() does exit(), not _exit()?
1313 // NB: IIRC on NOMMU we are after _vfork_, not fork!
1315 debug_printf("exec of %s\n", argv[0]);
1316 execvp(argv[0], argv);
1317 bb_perror_msg("cannot exec '%s'", argv[0]);
1321 static void pseudo_exec(struct child_prog *child)
1326 pseudo_exec_argv(child->argv);
1330 debug_printf("runtime nesting to group\n");
1331 // FIXME: do not modify globals! Think vfork!
1332 #if ENABLE_HUSH_INTERACTIVE
1333 interactive_fd = 0; /* crucial!!!! */
1335 rcode = run_list_real(child->group);
1336 /* OK to leak memory by not calling free_pipe_list,
1337 * since this process is about to exit */
1341 /* Can happen. See what bash does with ">foo" by itself. */
1342 debug_printf("trying to pseudo_exec null command\n");
1343 _exit(EXIT_SUCCESS);
1347 static const char *get_cmdtext(struct pipe *pi)
1353 /* This is subtle. ->cmdtext is created only on first backgrounding.
1354 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
1355 * On subsequent bg argv can be trashed, but we won't use it */
1358 argv = pi->progs[0].argv;
1359 if (!argv || !argv[0])
1360 return (pi->cmdtext = xzalloc(1));
1363 do len += strlen(*argv) + 1; while (*++argv);
1364 pi->cmdtext = p = xmalloc(len);
1365 argv = pi->progs[0].argv;
1367 len = strlen(*argv);
1368 memcpy(p, *argv, len);
1378 static void insert_bg_job(struct pipe *pi)
1380 struct pipe *thejob;
1382 /* Linear search for the ID of the job to use */
1384 for (thejob = job_list; thejob; thejob = thejob->next)
1385 if (thejob->jobid >= pi->jobid)
1386 pi->jobid = thejob->jobid + 1;
1388 /* add thejob to the list of running jobs */
1390 thejob = job_list = xmalloc(sizeof(*thejob));
1392 for (thejob = job_list; thejob->next; thejob = thejob->next)
1394 thejob->next = xmalloc(sizeof(*thejob));
1395 thejob = thejob->next;
1398 /* physically copy the struct job */
1399 memcpy(thejob, pi, sizeof(struct pipe));
1400 thejob->progs = xmalloc(sizeof(pi->progs[0]) * pi->num_progs);
1401 memcpy(thejob->progs, pi->progs, sizeof(pi->progs[0]) * pi->num_progs);
1402 thejob->next = NULL;
1403 /*seems to be wrong:*/
1404 /*thejob->running_progs = thejob->num_progs;*/
1405 /*thejob->stopped_progs = 0;*/
1406 thejob->cmdtext = xstrdup(get_cmdtext(pi));
1408 /* we don't wait for background thejobs to return -- append it
1409 to the list of backgrounded thejobs and leave it alone */
1410 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
1411 last_bg_pid = thejob->progs[0].pid;
1412 last_jobid = thejob->jobid;
1415 static void remove_bg_job(struct pipe *pi)
1417 struct pipe *prev_pipe;
1419 if (pi == job_list) {
1420 job_list = pi->next;
1422 prev_pipe = job_list;
1423 while (prev_pipe->next != pi)
1424 prev_pipe = prev_pipe->next;
1425 prev_pipe->next = pi->next;
1428 last_jobid = job_list->jobid;
1433 /* remove a backgrounded job */
1434 static void delete_finished_bg_job(struct pipe *pi)
1437 pi->stopped_progs = 0;
1443 /* Checks to see if any processes have exited -- if they
1444 have, figure out why and see if a job has completed */
1445 static int checkjobs(struct pipe* fg_pipe)
1456 attributes = WUNTRACED;
1457 if (fg_pipe == NULL) {
1458 attributes |= WNOHANG;
1461 /* Do we do this right?
1462 * bash-3.00# sleep 20 | false
1464 * [3]+ Stopped sleep 20 | false
1465 * bash-3.00# echo $?
1466 * 1 <========== bg pipe is not fully done, but exitcode is already known!
1469 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
1470 //are stopped. Testcase: "cat | cat" in a script (not on command line)
1471 // + killall -STOP cat
1474 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1475 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
1477 #ifdef DEBUG_SHELL_JOBS
1478 if (WIFSTOPPED(status))
1479 debug_jobs_printf("pid %d stopped by sig %d (exitcode %d)\n",
1480 childpid, WSTOPSIG(status), WEXITSTATUS(status));
1481 if (WIFSIGNALED(status))
1482 debug_jobs_printf("pid %d killed by sig %d (exitcode %d)\n",
1483 childpid, WTERMSIG(status), WEXITSTATUS(status));
1484 if (WIFEXITED(status))
1485 debug_jobs_printf("pid %d exited, exitcode %d\n",
1486 childpid, WEXITSTATUS(status));
1488 /* Were we asked to wait for fg pipe? */
1491 for (i = 0; i < fg_pipe->num_progs; i++) {
1492 debug_jobs_printf("check pid %d\n", fg_pipe->progs[i].pid);
1493 if (fg_pipe->progs[i].pid == childpid) {
1494 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
1496 fg_pipe->progs[i].pid = 0;
1497 fg_pipe->running_progs--;
1498 if (i == fg_pipe->num_progs-1)
1499 /* last process gives overall exitstatus */
1500 rcode = WEXITSTATUS(status);
1502 fg_pipe->progs[i].is_stopped = 1;
1503 fg_pipe->stopped_progs++;
1505 debug_jobs_printf("fg_pipe: running_progs %d stopped_progs %d\n",
1506 fg_pipe->running_progs, fg_pipe->stopped_progs);
1507 if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) {
1508 /* All processes in fg pipe have exited/stopped */
1510 if (fg_pipe->running_progs)
1511 insert_bg_job(fg_pipe);
1515 /* There are still running processes in the fg pipe */
1519 /* fall through to searching process in bg pipes */
1523 /* We asked to wait for bg or orphaned children */
1524 /* No need to remember exitcode in this case */
1525 for (pi = job_list; pi; pi = pi->next) {
1527 while (prognum < pi->num_progs) {
1528 if (pi->progs[prognum].pid == childpid)
1529 goto found_pi_and_prognum;
1535 /* Happens when shell is used as init process (init=/bin/sh) */
1536 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1540 found_pi_and_prognum:
1543 pi->progs[prognum].pid = 0;
1544 pi->running_progs--;
1545 if (!pi->running_progs) {
1546 printf(JOB_STATUS_FORMAT, pi->jobid,
1547 "Done", pi->cmdtext);
1548 delete_finished_bg_job(pi);
1552 pi->stopped_progs++;
1553 pi->progs[prognum].is_stopped = 1;
1558 /* wait found no children or failed */
1560 if (childpid && errno != ECHILD)
1561 bb_perror_msg("waitpid");
1563 /* move the shell to the foreground */
1564 //if (interactive_fd && tcsetpgrp(interactive_fd, getpgid(0)))
1565 // bb_perror_msg("tcsetpgrp-2");
1570 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
1573 int rcode = checkjobs(fg_pipe);
1574 /* Job finished, move the shell to the foreground */
1576 debug_printf("fg'ing ourself: getpgid(0)=%d\n", (int)p);
1577 if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
1578 bb_perror_msg("tcsetpgrp-4a");
1583 #if ENABLE_FEATURE_SH_STANDALONE
1584 /* run_pipe_real's helper */
1585 static int run_single_fg_nofork(struct pipe *pi, const struct bb_applet *a,
1590 /* TSTP handler will store pid etc in pi */
1592 save_nofork_data(&nofork_save);
1593 if (sigsetjmp(nofork_jb, 1) == 0) {
1594 signal_SA_RESTART(SIGTSTP, handler_ctrl_z);
1595 signal(SIGINT, handler_ctrl_c);
1596 rcode = run_nofork_applet_prime(&nofork_save, a, argv);
1597 if (--nofork_save.saved != 0) {
1598 /* Ctrl-Z forked, we are child */
1603 /* Ctrl-Z forked, we are parent; or Ctrl-C.
1604 * Sighandler has longjmped us here */
1605 signal(SIGINT, SIG_IGN);
1606 signal(SIGTSTP, SIG_IGN);
1607 debug_jobs_printf("Exiting nofork early\n");
1608 restore_nofork_data(&nofork_save);
1609 if (nofork_save.saved == 0) /* Ctrl-Z, not Ctrl-C */
1612 putchar('\n'); /* bash does this on Ctrl-C */
1615 return run_nofork_applet(a, argv);
1620 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1621 * to finish. See checkjobs().
1623 * return code is normally -1, when the caller has to wait for children
1624 * to finish to determine the exit status of the pipe. If the pipe
1625 * is a simple builtin command, however, the action is done by the
1626 * time run_pipe_real returns, and the exit code is provided as the
1629 * The input of the pipe is always stdin, the output is always
1630 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1631 * because it tries to avoid running the command substitution in
1632 * subshell, when that is in fact necessary. The subshell process
1633 * now has its stdout directed to the input of the appropriate pipe,
1634 * so this routine is noticeably simpler.
1636 static int run_pipe_real(struct pipe *pi)
1639 int nextin, nextout;
1640 int pipefds[2]; /* pipefds[0] is for reading */
1641 struct child_prog *child;
1642 const struct built_in_command *x;
1644 /* it is not always needed, but we aim to smaller code */
1645 int squirrel[] = { -1, -1, -1 };
1647 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
1653 pi->running_progs = 0;
1654 pi->stopped_progs = 0;
1656 /* Check if this is a simple builtin (not part of a pipe).
1657 * Builtins within pipes have to fork anyway, and are handled in
1658 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1660 child = &(pi->progs[0]);
1661 if (single_fg && child->group && child->subshell == 0) {
1662 debug_printf("non-subshell grouping\n");
1663 setup_redirects(child, squirrel);
1664 /* XXX could we merge code with following builtin case,
1665 * by creating a pseudo builtin that calls run_list_real? */
1666 rcode = run_list_real(child->group);
1667 restore_redirects(squirrel);
1671 if (single_fg && child->argv != NULL) {
1672 char **argv = child->argv;
1674 for (i = 0; is_assignment(argv[i]); i++)
1676 if (i != 0 && argv[i] == NULL) {
1677 /* assignments, but no command: set the local environment */
1678 for (i = 0; argv[i] != NULL; i++) {
1679 /* Ok, this case is tricky. We have to decide if this is a
1680 * local variable, or an already exported variable. If it is
1681 * already exported, we have to export the new value. If it is
1682 * not exported, we need only set this as a local variable.
1683 * This junk is all to decide whether or not to export this
1687 name = xstrdup(argv[i]);
1688 debug_printf("Local environment set: %s\n", name);
1689 value = strchr(name, '=');
1692 if (get_local_var(name)) {
1696 p = insert_var_value(argv[i]);
1697 set_local_var(p, export_me);
1701 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1703 for (i = 0; is_assignment(argv[i]); i++) {
1704 p = insert_var_value(argv[i]);
1714 str = make_string(argv + i);
1715 parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1717 return last_return_code;
1719 for (x = bltins; x->cmd; x++) {
1720 if (strcmp(argv[i], x->cmd) == 0) {
1721 if (x->function == builtin_exec && argv[i+1] == NULL) {
1722 debug_printf("magic exec\n");
1723 setup_redirects(child, NULL);
1724 return EXIT_SUCCESS;
1726 debug_printf("builtin inline %s\n", argv[0]);
1727 /* XXX setup_redirects acts on file descriptors, not FILEs.
1728 * This is perfect for work that comes after exec().
1729 * Is it really safe for inline use? Experimentally,
1730 * things seem to work with glibc. */
1731 // TODO: fflush(NULL)?
1732 setup_redirects(child, squirrel);
1733 rcode = x->function(argv + i);
1734 restore_redirects(squirrel);
1738 #if ENABLE_FEATURE_SH_STANDALONE
1740 const struct bb_applet *a = find_applet_by_name(argv[i]);
1741 if (a && a->nofork) {
1742 setup_redirects(child, squirrel);
1743 rcode = run_single_fg_nofork(pi, a, argv + i);
1744 restore_redirects(squirrel);
1751 /* Going to fork a child per each pipe member */
1753 /* Disable job control signals for shell (parent) and
1754 * for initial child code after fork */
1755 set_jobctrl_sighandler(SIG_IGN);
1757 for (i = 0; i < pi->num_progs; i++) {
1758 child = &(pi->progs[i]);
1760 /* pipes are inserted between pairs of commands */
1761 if ((i + 1) < pi->num_progs) {
1762 if (pipe(pipefds) < 0)
1763 bb_perror_msg_and_die("pipe");
1764 nextout = pipefds[1];
1770 /* XXX test for failed fork()? */
1772 child->pid = fork();
1774 child->pid = vfork();
1776 if (!child->pid) { /* child */
1777 /* Every child adds itself to new process group
1778 * with pgid == pid of first child in pipe */
1780 if (interactive_fd) {
1781 /* Don't do pgrp restore anymore on fatal signals */
1782 set_fatal_sighandler(SIG_DFL);
1783 if (pi->pgrp < 0) /* true for 1st process only */
1784 pi->pgrp = getpid();
1785 if (setpgid(0, pi->pgrp) == 0 && pi->followup != PIPE_BG) {
1786 /* We do it in *every* child, not just first,
1788 tcsetpgrp(interactive_fd, pi->pgrp);
1792 // in non-interactive case fatal sigs are already SIG_DFL
1802 if (pipefds[0] != -1) {
1803 close(pipefds[0]); /* opposite end of our output pipe */
1805 /* Like bash, explicit redirects override pipes,
1806 * and the pipe fd is available for dup'ing. */
1807 setup_redirects(child, NULL);
1809 /* Restore default handlers just prior to exec */
1810 set_jobctrl_sighandler(SIG_DFL);
1811 set_misc_sighandler(SIG_DFL);
1812 signal(SIGCHLD, SIG_DFL);
1816 pi->running_progs++;
1819 /* Second and next children need to know pid of first one */
1821 pi->pgrp = child->pid;
1824 /* Don't check for errors. The child may be dead already,
1825 * in which case setpgid returns error code EACCES. */
1826 //why we do it at all?? child does it itself
1827 //if (interactive_fd)
1828 // setpgid(child->pid, pi->pgrp);
1835 /* If there isn't another process, nextin is garbage
1836 but it doesn't matter */
1837 nextin = pipefds[0];
1842 static int run_list_real(struct pipe *pi)
1844 char *save_name = NULL;
1846 char **save_list = NULL;
1850 int rcode = 0, flag_skip = 1;
1851 int flag_restore = 0;
1852 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
1853 reserved_style rmode, skip_more_in_this_rmode = RES_XXXX;
1854 /* check syntax for "for" */
1855 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1856 if ((rpipe->r_mode == RES_IN || rpipe->r_mode == RES_FOR)
1857 && (rpipe->next == NULL)
1862 if ((rpipe->r_mode == RES_IN && rpipe->next->r_mode == RES_IN && rpipe->next->progs->argv != NULL)
1863 || (rpipe->r_mode == RES_FOR && rpipe->next->r_mode != RES_IN)
1869 for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1870 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL
1871 || pi->r_mode == RES_FOR
1880 debug_printf("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n",
1881 rmode, if_code, next_if_code, skip_more_in_this_rmode);
1882 if (rmode == skip_more_in_this_rmode && flag_skip) {
1883 if (pi->followup == PIPE_SEQ)
1888 skip_more_in_this_rmode = RES_XXXX;
1889 if (rmode == RES_THEN || rmode == RES_ELSE)
1890 if_code = next_if_code;
1891 if (rmode == RES_THEN && if_code)
1893 if (rmode == RES_ELSE && !if_code)
1895 if (rmode == RES_ELIF && !if_code)
1897 if (rmode == RES_FOR && pi->num_progs) {
1899 /* if no variable values after "in" we skip "for" */
1900 if (!pi->next->progs->argv)
1902 /* create list of variable values */
1903 list = make_list_in(pi->next->progs->argv,
1904 pi->progs->argv[0]);
1906 save_name = pi->progs->argv[0];
1907 pi->progs->argv[0] = NULL;
1911 free(pi->progs->argv[0]);
1915 pi->progs->argv[0] = save_name;
1916 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
1919 /* insert new value from list for variable */
1920 if (pi->progs->argv[0])
1921 free(pi->progs->argv[0]);
1922 pi->progs->argv[0] = *list++;
1923 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
1925 if (rmode == RES_IN)
1927 if (rmode == RES_DO) {
1931 if (rmode == RES_DONE) {
1938 if (pi->num_progs == 0)
1940 save_num_progs = pi->num_progs; /* save number of programs */
1941 rcode = run_pipe_real(pi);
1942 debug_printf("run_pipe_real returned %d\n", rcode);
1944 /* We only ran a builtin: rcode was set by the return value
1945 * of run_pipe_real(), and we don't need to wait for anything. */
1946 } else if (pi->followup == PIPE_BG) {
1947 /* XXX check bash's behavior with nontrivial pipes */
1948 /* XXX compute jobid */
1949 /* XXX what does bash do with attempts to background builtins? */
1953 rcode = EXIT_SUCCESS;
1956 if (interactive_fd) {
1957 rcode = checkjobs_and_fg_shell(pi);
1961 rcode = checkjobs(pi);
1963 debug_printf("checkjobs returned %d\n", rcode);
1965 last_return_code = rcode;
1966 pi->num_progs = save_num_progs; /* restore number of programs */
1967 if (rmode == RES_IF || rmode == RES_ELIF)
1968 next_if_code = rcode; /* can be overwritten a number of times */
1969 if (rmode == RES_WHILE)
1970 flag_rep = !last_return_code;
1971 if (rmode == RES_UNTIL)
1972 flag_rep = last_return_code;
1973 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
1974 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
1976 skip_more_in_this_rmode = rmode;
1983 /* return code is the exit status of the pipe */
1984 static int free_pipe(struct pipe *pi, int indent)
1987 struct child_prog *child;
1988 struct redir_struct *r, *rnext;
1989 int a, i, ret_code = 0;
1991 if (pi->stopped_progs > 0)
1993 final_printf("%s run pipe: (pid %d)\n", indenter(indent), getpid());
1994 for (i = 0; i < pi->num_progs; i++) {
1995 child = &pi->progs[i];
1996 final_printf("%s command %d:\n", indenter(indent), i);
1998 for (a = 0, p = child->argv; *p; a++, p++) {
1999 final_printf("%s argv[%d] = %s\n", indenter(indent), a, *p);
2001 globfree(&child->glob_result);
2003 } else if (child->group) {
2004 final_printf("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
2005 ret_code = free_pipe_list(child->group, indent+3);
2006 final_printf("%s end group\n", indenter(indent));
2008 final_printf("%s (nil)\n", indenter(indent));
2010 for (r = child->redirects; r; r = rnext) {
2011 final_printf("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
2013 /* guard against the case >$FOO, where foo is unset or blank */
2014 if (r->word.gl_pathv) {
2015 final_printf(" %s\n", *r->word.gl_pathv);
2019 final_printf("&%d\n", r->dup);
2024 child->redirects = NULL;
2026 free(pi->progs); /* children are an array, they get freed all at once */
2035 static int free_pipe_list(struct pipe *head, int indent)
2037 int rcode = 0; /* if list has no members */
2038 struct pipe *pi, *next;
2039 for (pi = head; pi; pi = next) {
2040 final_printf("%s pipe reserved mode %d\n", indenter(indent), pi->r_mode);
2041 rcode = free_pipe(pi, indent);
2042 final_printf("%s pipe followup code %d\n", indenter(indent), pi->followup);
2044 /*pi->next = NULL;*/
2050 /* Select which version we will use */
2051 static int run_list(struct pipe *pi)
2054 if (fake_mode == 0) {
2055 rcode = run_list_real(pi);
2057 /* free_pipe_list has the side effect of clearing memory
2058 * In the long run that function can be merged with run_list_real,
2059 * but doing that now would hobble the debugging effort. */
2060 free_pipe_list(pi,0);
2064 /* The API for glob is arguably broken. This routine pushes a non-matching
2065 * string into the output structure, removing non-backslashed backslashes.
2066 * If someone can prove me wrong, by performing this function within the
2067 * original glob(3) api, feel free to rewrite this routine into oblivion.
2068 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2069 * XXX broken if the last character is '\\', check that before calling.
2071 static int globhack(const char *src, int flags, glob_t *pglob)
2076 for (cnt = 1, s = src; s && *s; s++) {
2077 if (*s == '\\') s++;
2082 return GLOB_NOSPACE;
2083 if (!(flags & GLOB_APPEND)) {
2084 pglob->gl_pathv = NULL;
2085 pglob->gl_pathc = 0;
2089 pathc = ++pglob->gl_pathc;
2090 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2091 if (pglob->gl_pathv == NULL)
2092 return GLOB_NOSPACE;
2093 pglob->gl_pathv[pathc-1] = dest;
2094 pglob->gl_pathv[pathc] = NULL;
2095 for (s = src; s && *s; s++, dest++) {
2096 if (*s == '\\') s++;
2103 /* XXX broken if the last character is '\\', check that before calling */
2104 static int glob_needed(const char *s)
2107 if (*s == '\\') s++;
2108 if (strchr("*[?", *s)) return 1;
2113 static int xglob(o_string *dest, int flags, glob_t *pglob)
2117 /* short-circuit for null word */
2118 /* we can code this better when the debug_printf's are gone */
2119 if (dest->length == 0) {
2120 if (dest->nonnull) {
2121 /* bash man page calls this an "explicit" null */
2122 gr = globhack(dest->data, flags, pglob);
2123 debug_printf("globhack returned %d\n", gr);
2127 } else if (glob_needed(dest->data)) {
2128 gr = glob(dest->data, flags, NULL, pglob);
2129 debug_printf("glob returned %d\n", gr);
2130 if (gr == GLOB_NOMATCH) {
2131 /* quote removal, or more accurately, backslash removal */
2132 gr = globhack(dest->data, flags, pglob);
2133 debug_printf("globhack returned %d\n", gr);
2136 gr = globhack(dest->data, flags, pglob);
2137 debug_printf("globhack returned %d\n", gr);
2139 if (gr == GLOB_NOSPACE)
2140 bb_error_msg_and_die("out of memory during glob");
2141 if (gr != 0) { /* GLOB_ABORTED ? */
2142 bb_error_msg("glob(3) error %d", gr);
2144 /* globprint(glob_target); */
2148 static char **make_list_in(char **inp, char *name)
2151 int name_len = strlen(name);
2156 /* create list of variable values */
2157 list = xmalloc(sizeof(*list));
2158 for (i = 0; inp[i]; i++) {
2159 p3 = insert_var_value(inp[i]);
2166 p2 = strchr(p1, ' ');
2173 /* we use n + 2 in realloc for list, because we add
2174 * new element and then we will add NULL element */
2175 list = xrealloc(list, sizeof(*list) * (n + 2));
2176 list[n] = xmalloc(2 + name_len + len);
2177 strcpy(list[n], name);
2178 strcat(list[n], "=");
2179 strncat(list[n], p1, len);
2180 list[n++][name_len + len + 1] = '\0';
2183 if (p3 != inp[i]) free(p3);
2189 static char *insert_var_value(char *inp)
2191 int res_str_len = 0;
2194 char *p, *res_str = NULL;
2197 while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
2200 res_str = xrealloc(res_str, (res_str_len + len));
2201 strncpy((res_str + res_str_len), inp, len);
2205 p = strchr(inp, SPECIAL_VAR_SYMBOL);
2207 p1 = lookup_param(inp);
2209 len = res_str_len + strlen(p1);
2210 res_str = xrealloc(res_str, (1 + len));
2211 strcpy((res_str + res_str_len), p1);
2214 *p = SPECIAL_VAR_SYMBOL;
2219 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
2220 strcpy((res_str + res_str_len), inp);
2221 while ((p = strchr(res_str, '\n'))) {
2225 return (res_str == NULL) ? inp : res_str;
2228 /* This is used to get/check local shell variables */
2229 static const char *get_local_var(const char *s)
2231 struct variables *cur;
2235 for (cur = top_vars; cur; cur = cur->next)
2236 if (strcmp(cur->name, s) == 0)
2241 /* This is used to set local shell variables
2242 flg_export == 0 if only local (not exporting) variable
2243 flg_export == 1 if "new" exporting environ
2244 flg_export > 1 if current startup environ (not call putenv()) */
2245 static int set_local_var(const char *s, int flg_export)
2249 struct variables *cur;
2253 /* Assume when we enter this function that we are already in
2254 * NAME=VALUE format. So the first order of business is to
2255 * split 's' on the '=' into 'name' and 'value' */
2256 value = strchr(name, '=');
2257 /*if (value == 0 && ++value == 0) ??? -vda */
2258 if (value == NULL || value[1] == '\0') {
2264 for (cur = top_vars; cur; cur = cur->next) {
2265 if (strcmp(cur->name, name) == 0)
2270 if (strcmp(cur->value, value) == 0) {
2271 if (flg_export > 0 && cur->flg_export == 0)
2272 cur->flg_export = flg_export;
2275 } else if (cur->flg_read_only) {
2276 bb_error_msg("%s: readonly variable", name);
2279 if (flg_export > 0 || cur->flg_export > 1)
2280 cur->flg_export = 1;
2281 free((char*)cur->value);
2283 cur->value = strdup(value);
2286 cur = malloc(sizeof(struct variables));
2290 cur->name = strdup(name);
2295 struct variables *bottom = top_vars;
2296 cur->value = strdup(value);
2298 cur->flg_export = flg_export;
2299 cur->flg_read_only = 0;
2300 while (bottom->next)
2301 bottom = bottom->next;
2307 if (result == 0 && cur->flg_export == 1) {
2309 result = putenv(name);
2312 if (result > 0) /* equivalent to previous set */
2318 static void unset_local_var(const char *name)
2320 struct variables *cur, *next;
2324 for (cur = top_vars; cur; cur = cur->next) {
2325 if (strcmp(cur->name, name) == 0) {
2326 if (cur->flg_read_only) {
2327 bb_error_msg("%s: readonly variable", name);
2330 if (cur->flg_export)
2331 unsetenv(cur->name);
2332 free((char*)cur->name);
2333 free((char*)cur->value);
2335 while (next->next != cur)
2337 next->next = cur->next;
2344 static int is_assignment(const char *s)
2346 if (!s || !isalpha(*s))
2349 while (isalnum(*s) || *s == '_')
2354 /* the src parameter allows us to peek forward to a possible &n syntax
2355 * for file descriptor duplication, e.g., "2>&1".
2356 * Return code is 0 normally, 1 if a syntax error is detected in src.
2357 * Resource errors (in xmalloc) cause the process to exit */
2358 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2359 struct in_str *input)
2361 struct child_prog *child = ctx->child;
2362 struct redir_struct *redir = child->redirects;
2363 struct redir_struct *last_redir = NULL;
2365 /* Create a new redir_struct and drop it onto the end of the linked list */
2368 redir = redir->next;
2370 redir = xmalloc(sizeof(struct redir_struct));
2372 redir->word.gl_pathv = NULL;
2374 last_redir->next = redir;
2376 child->redirects = redir;
2379 redir->type = style;
2380 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
2382 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2384 /* Check for a '2>&1' type redirect */
2385 redir->dup = redirect_dup_num(input);
2386 if (redir->dup == -2) return 1; /* syntax error */
2387 if (redir->dup != -1) {
2388 /* Erik had a check here that the file descriptor in question
2389 * is legit; I postpone that to "run time"
2390 * A "-" representation of "close me" shows up as a -3 here */
2391 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2393 /* We do _not_ try to open the file that src points to,
2394 * since we need to return and let src be expanded first.
2395 * Set ctx->pending_redirect, so we know what to do at the
2396 * end of the next parsed word.
2398 ctx->pending_redirect = redir;
2403 static struct pipe *new_pipe(void)
2406 pi = xzalloc(sizeof(struct pipe));
2407 /*pi->num_progs = 0;*/
2408 /*pi->progs = NULL;*/
2409 /*pi->next = NULL;*/
2410 /*pi->followup = 0; invalid */
2412 pi->r_mode = RES_NONE;
2416 static void initialize_context(struct p_context *ctx)
2419 ctx->pending_redirect = NULL;
2421 ctx->list_head = new_pipe();
2422 ctx->pipe = ctx->list_head;
2426 done_command(ctx); /* creates the memory for working child */
2429 /* normal return is 0
2430 * if a reserved word is found, and processed, return 1
2431 * should handle if, then, elif, else, fi, for, while, until, do, done.
2432 * case, function, and select are obnoxious, save those for later.
2434 static int reserved_word(o_string *dest, struct p_context *ctx)
2436 struct reserved_combo {
2441 /* Mostly a list of accepted follow-up reserved words.
2442 * FLAG_END means we are done with the sequence, and are ready
2443 * to turn the compound list into a command.
2444 * FLAG_START means the word must start a new compound list.
2446 static const struct reserved_combo reserved_list[] = {
2447 { "if", RES_IF, FLAG_THEN | FLAG_START },
2448 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2449 { "elif", RES_ELIF, FLAG_THEN },
2450 { "else", RES_ELSE, FLAG_FI },
2451 { "fi", RES_FI, FLAG_END },
2452 { "for", RES_FOR, FLAG_IN | FLAG_START },
2453 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2454 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2455 { "in", RES_IN, FLAG_DO },
2456 { "do", RES_DO, FLAG_DONE },
2457 { "done", RES_DONE, FLAG_END }
2459 enum { NRES = sizeof(reserved_list)/sizeof(reserved_list[0]) };
2460 const struct reserved_combo *r;
2462 for (r = reserved_list; r < reserved_list+NRES; r++) {
2463 if (strcmp(dest->data, r->literal) == 0) {
2464 debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
2465 if (r->flag & FLAG_START) {
2466 struct p_context *new = xmalloc(sizeof(struct p_context));
2467 debug_printf("push stack\n");
2468 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2475 *new = *ctx; /* physical copy */
2476 initialize_context(ctx);
2478 } else if (ctx->w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
2485 ctx->old_flag = r->flag;
2486 if (ctx->old_flag & FLAG_END) {
2487 struct p_context *old;
2488 debug_printf("pop stack\n");
2489 done_pipe(ctx, PIPE_SEQ);
2491 old->child->group = ctx->list_head;
2492 old->child->subshell = 0;
2493 *ctx = *old; /* physical copy */
2503 /* normal return is 0.
2504 * Syntax or xglob errors return 1. */
2505 static int done_word(o_string *dest, struct p_context *ctx)
2507 struct child_prog *child = ctx->child;
2508 glob_t *glob_target;
2511 debug_printf("done_word: %s %p\n", dest->data, child);
2512 if (dest->length == 0 && !dest->nonnull) {
2513 debug_printf(" true null, ignored\n");
2516 if (ctx->pending_redirect) {
2517 glob_target = &ctx->pending_redirect->word;
2521 return 1; /* syntax error, groups and arglists don't mix */
2523 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2524 debug_printf("checking %s for reserved-ness\n", dest->data);
2525 if (reserved_word(dest, ctx))
2526 return (ctx->w == RES_SNTX);
2528 glob_target = &child->glob_result;
2529 if (child->argv) flags |= GLOB_APPEND;
2531 gr = xglob(dest, flags, glob_target);
2532 if (gr != 0) return 1;
2535 if (ctx->pending_redirect) {
2536 ctx->pending_redirect = NULL;
2537 if (glob_target->gl_pathc != 1) {
2538 bb_error_msg("ambiguous redirect");
2542 child->argv = glob_target->gl_pathv;
2544 if (ctx->w == RES_FOR) {
2545 done_word(dest, ctx);
2546 done_pipe(ctx, PIPE_SEQ);
2551 /* The only possible error here is out of memory, in which case
2553 static int done_command(struct p_context *ctx)
2555 /* The child is really already in the pipe structure, so
2556 * advance the pipe counter and make a new, null child.
2557 * Only real trickiness here is that the uncommitted
2558 * child structure, to which ctx->child points, is not
2559 * counted in pi->num_progs. */
2560 struct pipe *pi = ctx->pipe;
2561 struct child_prog *prog = ctx->child;
2563 if (prog && prog->group == NULL
2564 && prog->argv == NULL
2565 && prog->redirects == NULL
2567 debug_printf("done_command: skipping null command\n");
2572 debug_printf("done_command: num_progs incremented to %d\n", pi->num_progs);
2574 debug_printf("done_command: initializing\n");
2576 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2578 prog = pi->progs + pi->num_progs;
2579 memset(prog, 0, sizeof(*prog));
2580 /*prog->redirects = NULL;*/
2581 /*prog->argv = NULL; */
2582 /*prog->is_stopped = 0;*/
2583 /*prog->group = NULL;*/
2584 /*prog->glob_result.gl_pathv = NULL;*/
2588 prog->type = ctx->type;
2590 /* but ctx->pipe and ctx->list_head remain unchanged */
2594 static int done_pipe(struct p_context *ctx, pipe_style type)
2597 done_command(ctx); /* implicit closure of previous command */
2598 debug_printf("done_pipe, type %d\n", type);
2599 ctx->pipe->followup = type;
2600 ctx->pipe->r_mode = ctx->w;
2602 ctx->pipe->next = new_p;
2605 done_command(ctx); /* set up new pipe to accept commands */
2609 /* peek ahead in the in_str to find out if we have a "&n" construct,
2610 * as in "2>&1", that represents duplicating a file descriptor.
2611 * returns either -2 (syntax error), -1 (no &), or the number found.
2613 static int redirect_dup_num(struct in_str *input)
2615 int ch, d = 0, ok = 0;
2617 if (ch != '&') return -1;
2619 b_getch(input); /* get the & */
2623 return -3; /* "-" represents "close me" */
2625 while (isdigit(ch)) {
2626 d = d*10 + (ch-'0');
2633 bb_error_msg("ambiguous redirect");
2637 /* If a redirect is immediately preceded by a number, that number is
2638 * supposed to tell which file descriptor to redirect. This routine
2639 * looks for such preceding numbers. In an ideal world this routine
2640 * needs to handle all the following classes of redirects...
2641 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2642 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2643 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2644 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2645 * A -1 output from this program means no valid number was found, so the
2646 * caller should use the appropriate default for this redirection.
2648 static int redirect_opt_num(o_string *o)
2654 for (num = 0; num < o->length; num++) {
2655 if (!isdigit(*(o->data + num))) {
2659 /* reuse num (and save an int) */
2660 num = atoi(o->data);
2665 static FILE *generate_stream_from_list(struct pipe *head)
2668 int pid, channel[2];
2669 if (pipe(channel) < 0) bb_perror_msg_and_die("pipe");
2676 bb_perror_msg_and_die("fork");
2677 } else if (pid == 0) {
2679 if (channel[1] != 1) {
2680 dup2(channel[1], 1);
2683 _exit(run_list_real(head)); /* leaks memory */
2685 debug_printf("forked child %d\n", pid);
2687 pf = fdopen(channel[0], "r");
2688 debug_printf("pipe on FILE *%p\n", pf);
2692 /* this version hacked for testing purposes */
2693 /* return code is exit status of the process that is run. */
2694 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2697 o_string result = NULL_O_STRING;
2698 struct p_context inner;
2700 struct in_str pipe_str;
2701 initialize_context(&inner);
2703 /* recursion to generate command */
2704 retcode = parse_stream(&result, &inner, input, subst_end);
2705 if (retcode != 0) return retcode; /* syntax error or EOF */
2706 done_word(&result, &inner);
2707 done_pipe(&inner, PIPE_SEQ);
2710 p = generate_stream_from_list(inner.list_head);
2711 if (p == NULL) return 1;
2712 mark_open(fileno(p));
2713 setup_file_in_str(&pipe_str, p);
2715 /* now send results of command back into original context */
2716 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2717 /* XXX In case of a syntax error, should we try to kill the child?
2718 * That would be tough to do right, so just read until EOF. */
2720 while (b_getch(&pipe_str) != EOF)
2724 debug_printf("done reading from pipe, pclose()ing\n");
2725 /* This is the step that wait()s for the child. Should be pretty
2726 * safe, since we just read an EOF from its stdout. We could try
2727 * to better, by using wait(), and keeping track of background jobs
2728 * at the same time. That would be a lot of work, and contrary
2729 * to the KISS philosophy of this program. */
2730 mark_closed(fileno(p));
2731 retcode = pclose(p);
2732 free_pipe_list(inner.list_head, 0);
2733 debug_printf("pclosed, retcode=%d\n", retcode);
2734 /* XXX this process fails to trim a single trailing newline */
2738 static int parse_group(o_string *dest, struct p_context *ctx,
2739 struct in_str *input, int ch)
2741 int rcode, endch = 0;
2742 struct p_context sub;
2743 struct child_prog *child = ctx->child;
2746 return 1; /* syntax error, groups and arglists don't mix */
2748 initialize_context(&sub);
2752 child->subshell = 1;
2758 syntax(); /* really logic error */
2760 rcode = parse_stream(dest, &sub, input, endch);
2761 done_word(dest, &sub); /* finish off the final word in the subcontext */
2762 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2763 child->group = sub.list_head;
2765 /* child remains "open", available for possible redirects */
2768 /* basically useful version until someone wants to get fancier,
2769 * see the bash man page under "Parameter Expansion" */
2770 static const char *lookup_param(const char *src)
2772 const char *p = NULL;
2776 p = get_local_var(src);
2781 /* Make new string for parser */
2782 static char* make_string(char ** inp)
2789 for (n = 0; inp[n]; n++) {
2790 p = insert_var_value(inp[n]);
2791 str = xrealloc(str, (len + strlen(p)));
2798 len = strlen(str) + 3;
2799 if (p != inp[n]) free(p);
2807 /* return code: 0 for OK, 1 for syntax error */
2808 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2812 int ch = input->peek(input); /* first character after the $ */
2813 debug_printf("handle_dollar: ch=%c\n", ch);
2815 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2817 while (ch = b_peek(input), isalnum(ch) || ch == '_') {
2821 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2822 } else if (isdigit(ch)) {
2823 i = ch - '0'; /* XXX is $0 special? */
2824 if (i < global_argc) {
2825 parse_string(dest, ctx, global_argv[i]); /* recursion */
2828 } else switch (ch) {
2830 b_adduint(dest, getpid());
2834 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2838 b_adduint(dest, last_return_code);
2842 b_adduint(dest, global_argc ? global_argc-1 : 0);
2846 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2849 /* XXX maybe someone will try to escape the '}' */
2851 ch = b_getch(input);
2852 if (ch == EOF || ch == '}')
2860 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2864 process_command_subs(dest, ctx, input, ')');
2868 for (i = 1; i < global_argc; i++) {
2869 parse_string(dest, ctx, global_argv[i]);
2870 if (i+1 < global_argc)
2871 parse_string(dest, ctx, sep);
2877 /* still unhandled, but should be eventually */
2878 bb_error_msg("unhandled syntax: $%c", ch);
2882 b_addqchr(dest,'$', dest->quote);
2884 /* Eat the character if the flag was set. If the compiler
2885 * is smart enough, we could substitute "b_getch(input);"
2886 * for all the "advance = 1;" above, and also end up with
2887 * a nice size-optimized program. Hah! That'll be the day.
2889 if (advance) b_getch(input);
2893 static int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2896 setup_string_in_str(&foo, src);
2897 return parse_stream(dest, ctx, &foo, '\0');
2900 /* return code is 0 for normal exit, 1 for syntax error */
2901 static int parse_stream(o_string *dest, struct p_context *ctx,
2902 struct in_str *input, int end_trigger)
2906 redir_type redir_style;
2909 /* Only double-quote state is handled in the state variable dest->quote.
2910 * A single-quote triggers a bypass of the main loop until its mate is
2911 * found. When recursing, quote state is passed in via dest->quote. */
2913 debug_printf("parse_stream, end_trigger=%d\n", end_trigger);
2914 while ((ch = b_getch(input)) != EOF) {
2916 next = (ch == '\n') ? 0 : b_peek(input);
2917 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2918 ch, ch, m, dest->quote);
2919 if (m == 0 || ((m == 1 || m == 2) && dest->quote)) {
2920 b_addqchr(dest, ch, dest->quote);
2923 if (m == 2) { /* unquoted IFS */
2924 if (done_word(dest, ctx)) {
2927 /* If we aren't performing a substitution, treat a newline as a
2928 * command separator. */
2929 if (end_trigger != '\0' && ch == '\n')
2930 done_pipe(ctx, PIPE_SEQ);
2932 if (ch == end_trigger && !dest->quote && ctx->w == RES_NONE) {
2933 debug_printf("leaving parse_stream (triggered)\n");
2940 if (dest->length == 0 && !dest->quote) {
2943 if (ch == EOF || ch == '\n')
2948 b_addqchr(dest, ch, dest->quote);
2956 b_addqchr(dest, '\\', dest->quote);
2957 b_addqchr(dest, b_getch(input), dest->quote);
2960 if (handle_dollar(dest, ctx, input) != 0) return 1;
2965 ch = b_getch(input);
2966 if (ch == EOF || ch == '\'')
2977 dest->quote = !dest->quote;
2980 process_command_subs(dest, ctx, input, '`');
2983 redir_fd = redirect_opt_num(dest);
2984 done_word(dest, ctx);
2985 redir_style = REDIRECT_OVERWRITE;
2987 redir_style = REDIRECT_APPEND;
2989 } else if (next == '(') {
2990 syntax(); /* until we support >(list) Process Substitution */
2993 setup_redirect(ctx, redir_fd, redir_style, input);
2996 redir_fd = redirect_opt_num(dest);
2997 done_word(dest, ctx);
2998 redir_style = REDIRECT_INPUT;
3000 redir_style = REDIRECT_HEREIS;
3002 } else if (next == '>') {
3003 redir_style = REDIRECT_IO;
3005 } else if (next == '(') {
3006 syntax(); /* until we support <(list) Process Substitution */
3009 setup_redirect(ctx, redir_fd, redir_style, input);
3012 done_word(dest, ctx);
3013 done_pipe(ctx, PIPE_SEQ);
3016 done_word(dest, ctx);
3019 done_pipe(ctx, PIPE_AND);
3021 done_pipe(ctx, PIPE_BG);
3025 done_word(dest, ctx);
3028 done_pipe(ctx, PIPE_OR);
3030 /* we could pick up a file descriptor choice here
3031 * with redirect_opt_num(), but bash doesn't do it.
3032 * "echo foo 2| cat" yields "foo 2". */
3038 if (parse_group(dest, ctx, input, ch) != 0)
3043 syntax(); /* Proper use of this character caught by end_trigger */
3046 syntax(); /* this is really an internal logic error */
3050 /* complain if quote? No, maybe we just finished a command substitution
3051 * that was quoted. Example:
3052 * $ echo "`cat foo` plus more"
3053 * and we just got the EOF generated by the subshell that ran "cat foo"
3054 * The only real complaint is if we got an EOF when end_trigger != '\0',
3055 * that is, we were really supposed to get end_trigger, and never got
3056 * one before the EOF. Can't use the standard "syntax error" return code,
3057 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3058 debug_printf("leaving parse_stream (EOF)\n");
3059 if (end_trigger != '\0')
3064 static void mapset(const char *set, int code)
3067 map[(unsigned char)*set++] = code;
3070 static void update_ifs_map(void)
3072 /* char *ifs and char map[256] are both globals. */
3073 ifs = getenv("IFS");
3074 if (ifs == NULL) ifs = " \t\n";
3075 /* Precompute a list of 'flow through' behavior so it can be treated
3076 * quickly up front. Computation is necessary because of IFS.
3077 * Special case handling of IFS == " \t\n" is not implemented.
3078 * The map[] array only really needs two bits each, and on most machines
3079 * that would be faster because of the reduced L1 cache footprint.
3081 memset(map, 0, sizeof(map)); /* most characters flow through always */
3082 mapset("\\$'\"`", 3); /* never flow through */
3083 mapset("<>;&|(){}#", 1); /* flow through if quoted */
3084 mapset(ifs, 2); /* also flow through if quoted */
3087 /* most recursion does not come through here, the exception is
3088 * from builtin_source() */
3089 static int parse_stream_outer(struct in_str *inp, int flag)
3091 struct p_context ctx;
3092 o_string temp = NULL_O_STRING;
3096 initialize_context(&ctx);
3098 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING))
3100 #if ENABLE_HUSH_INTERACTIVE
3101 inp->promptmode = 1;
3103 rcode = parse_stream(&temp, &ctx, inp, '\n');
3104 if (rcode != 1 && ctx.old_flag != 0) {
3107 if (rcode != 1 && ctx.old_flag == 0) {
3108 done_word(&temp, &ctx);
3109 done_pipe(&ctx, PIPE_SEQ);
3110 run_list(ctx.list_head);
3112 if (ctx.old_flag != 0) {
3119 free_pipe_list(ctx.list_head, 0);
3122 } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
3126 static int parse_string_outer(const char *s, int flag)
3128 struct in_str input;
3129 setup_string_in_str(&input, s);
3130 return parse_stream_outer(&input, flag);
3133 static int parse_file_outer(FILE *f)
3136 struct in_str input;
3137 setup_file_in_str(&input, f);
3138 rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3143 /* Make sure we have a controlling tty. If we get started under a job
3144 * aware app (like bash for example), make sure we are now in charge so
3145 * we don't fight over who gets the foreground */
3146 static void setup_job_control(void)
3150 saved_task_pgrp = shell_pgrp = getpgrp();
3151 debug_printf("saved_task_pgrp=%d\n", saved_task_pgrp);
3152 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3154 /* If we were ran as 'hush &',
3155 * sleep until we are in the foreground. */
3156 while (tcgetpgrp(interactive_fd) != shell_pgrp) {
3157 /* Send TTIN to ourself (should stop us) */
3158 kill(- shell_pgrp, SIGTTIN);
3159 shell_pgrp = getpgrp();
3162 /* Ignore job-control and misc signals. */
3163 set_jobctrl_sighandler(SIG_IGN);
3164 set_misc_sighandler(SIG_IGN);
3165 //huh? signal(SIGCHLD, SIG_IGN);
3167 /* We _must_ restore tty pgrp fatal signals */
3168 set_fatal_sighandler(sigexit);
3170 /* Put ourselves in our own process group. */
3171 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
3172 /* Grab control of the terminal. */
3173 tcsetpgrp(interactive_fd, getpid());
3177 int hush_main(int argc, char **argv);
3178 int hush_main(int argc, char **argv)
3184 #if ENABLE_FEATURE_EDITING
3185 line_input_state = new_line_input_t(FOR_SHELL);
3188 /* XXX what should these be while sourcing /etc/profile? */
3192 /* (re?) initialize globals. Sometimes hush_main() ends up calling
3193 * hush_main(), therefore we cannot rely on the BSS to zero out this
3194 * stuff. Reset these to 0 every time. */
3196 /* map[] is taken care of with call to update_ifs_map() */
3198 close_me_head = NULL;
3199 #if ENABLE_HUSH_INTERACTIVE
3208 /* Initialize some more globals to non-zero values */
3210 #if ENABLE_HUSH_INTERACTIVE
3211 #if ENABLE_FEATURE_EDITING
3212 cmdedit_set_initial_prompt();
3218 /* initialize our shell local variables with the values
3219 * currently living in the environment */
3223 set_local_var(*e++, 2); /* without call putenv() */
3225 last_return_code = EXIT_SUCCESS;
3227 if (argv[0] && argv[0][0] == '-') {
3228 debug_printf("\nsourcing /etc/profile\n");
3229 input = fopen("/etc/profile", "r");
3230 if (input != NULL) {
3231 mark_open(fileno(input));
3232 parse_file_outer(input);
3233 mark_closed(fileno(input));
3239 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3242 global_argv = argv + optind;
3243 global_argc = argc - optind;
3244 opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3247 // Well, we cannot just declare interactiveness,
3248 // we have to have some stuff (ctty, etc)
3249 /*interactive_fd++;*/
3256 fprintf(stderr, "Usage: sh [FILE]...\n"
3257 " or: sh -c command [args]...\n\n");
3265 /* A shell is interactive if the '-i' flag was given, or if all of
3266 * the following conditions are met:
3268 * no arguments remaining or the -s flag given
3269 * standard input is a terminal
3270 * standard output is a terminal
3271 * Refer to Posix.2, the description of the 'sh' utility. */
3272 if (argv[optind] == NULL && input == stdin
3273 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3275 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
3276 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
3277 if (saved_tty_pgrp >= 0) {
3278 /* try to dup to high fd#, >= 255 */
3279 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3280 if (interactive_fd < 0) {
3281 /* try to dup to any fd */
3282 interactive_fd = dup(STDIN_FILENO);
3283 if (interactive_fd < 0)
3287 // TODO: track & disallow any attempts of user
3288 // to (inadvertently) close/redirect it
3291 debug_printf("\ninteractive_fd=%d\n", interactive_fd);
3292 if (interactive_fd) {
3293 /* Looks like they want an interactive shell */
3294 setup_job_control();
3295 /* Make xfuncs do cleanup on exit */
3296 die_sleep = -1; /* flag */
3297 if (setjmp(die_jmp)) {
3298 /* xfunc has failed! die die die */
3299 hush_exit(xfunc_error_retval);
3301 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
3302 printf("\n\n%s hush - the humble shell v0.02\n", BB_BANNER);
3303 printf("Enter 'help' for a list of built-in commands.\n\n");
3306 #elif ENABLE_HUSH_INTERACTIVE
3307 /* no job control compiled, only prompt/line editing */
3308 if (argv[optind] == NULL && input == stdin
3309 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3311 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3312 if (interactive_fd < 0) {
3313 /* try to dup to any fd */
3314 interactive_fd = dup(STDIN_FILENO);
3315 if (interactive_fd < 0)
3323 if (argv[optind] == NULL) {
3324 opt = parse_file_outer(stdin);
3328 debug_printf("\nrunning script '%s'\n", argv[optind]);
3329 global_argv = argv + optind;
3330 global_argc = argc - optind;
3331 input = xfopen(argv[optind], "r");
3332 opt = parse_file_outer(input);
3334 #if ENABLE_FEATURE_CLEAN_UP
3336 if (cwd != bb_msg_unknown)
3339 struct variables *cur, *tmp;
3340 for (cur = top_vars; cur; cur = tmp) {
3342 if (!cur->flg_read_only) {
3343 free((char*)cur->name);
3344 free((char*)cur->value);
3352 hush_exit(opt ? opt : last_return_code);