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 //TODO: rename HUSH_INTERACTIVE -> HUSH_JOB,
90 //create HUSH_INTERACTIVE which controls only prompt + line editing,
91 //make HUSH_JOB dependent on it
93 #if !ENABLE_HUSH_INTERACTIVE
94 #undef ENABLE_FEATURE_EDITING
95 #define ENABLE_FEATURE_EDITING 0
96 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
97 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
100 #define SPECIAL_VAR_SYMBOL 03
101 #define FLAG_EXIT_FROM_LOOP 1
102 #define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
103 #define FLAG_REPARSING (1 << 2) /* >=2nd pass */
107 REDIRECT_OVERWRITE = 2,
113 /* The descrip member of this structure is only used to make debugging
115 static const struct {
121 { O_RDONLY, 0, "<" },
122 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
123 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
124 { O_RDONLY, -1, "<<" },
135 /* might eventually control execution */
153 FLAG_END = (1 << RES_NONE ),
154 FLAG_IF = (1 << RES_IF ),
155 FLAG_THEN = (1 << RES_THEN ),
156 FLAG_ELIF = (1 << RES_ELIF ),
157 FLAG_ELSE = (1 << RES_ELSE ),
158 FLAG_FI = (1 << RES_FI ),
159 FLAG_FOR = (1 << RES_FOR ),
160 FLAG_WHILE = (1 << RES_WHILE),
161 FLAG_UNTIL = (1 << RES_UNTIL),
162 FLAG_DO = (1 << RES_DO ),
163 FLAG_DONE = (1 << RES_DONE ),
164 FLAG_IN = (1 << RES_IN ),
165 FLAG_START = (1 << RES_XXXX ),
168 /* This holds pointers to the various results of parsing */
170 struct child_prog *child;
171 struct pipe *list_head;
173 struct redir_struct *pending_redirect;
175 int old_flag; /* for figuring out valid reserved words */
176 struct p_context *stack;
177 int type; /* define type of parser : ";$" common or special symbol */
178 /* How about quoting status? */
181 struct redir_struct {
182 struct redir_struct *next; /* pointer to the next redirect in the list */
183 redir_type type; /* type of redirection */
184 int fd; /* file descriptor being redirected */
185 int dup; /* -1, or file descriptor being duplicated */
186 glob_t word; /* *word.gl_pathv is the filename */
190 pid_t pid; /* 0 if exited */
191 char **argv; /* program name and arguments */
192 struct pipe *group; /* if non-NULL, first in group or subshell */
193 int subshell; /* flag, non-zero if group must be forked */
194 struct redir_struct *redirects; /* I/O redirections */
195 glob_t glob_result; /* result of parameter globbing */
196 int is_stopped; /* is the program currently running? */
197 struct pipe *family; /* pointer back to the child's parent pipe */
198 int sp; /* number of SPECIAL_VAR_SYMBOL */
204 int num_progs; /* total number of programs in job */
205 int running_progs; /* number of programs running (not exited) */
206 char *cmdbuf; /* buffer various argv's point into */
207 #if ENABLE_HUSH_INTERACTIVE
208 int jobid; /* job number */
209 char *cmdtext; /* name of job */
210 pid_t pgrp; /* process group ID for the job */
212 struct child_prog *progs; /* array of commands in pipe */
213 int stopped_progs; /* number of programs alive, but stopped */
214 int job_context; /* bitmask defining current context */
215 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
216 reserved_style r_mode; /* supports if, for, while, until */
220 struct close_me *next;
225 struct variables *next;
232 /* globals, connect us to the outside world
233 * the first three support $?, $#, and $1 */
234 static char **global_argv;
235 static int global_argc;
236 static int last_return_code;
237 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
239 /* "globals" within this file */
240 static const char *ifs;
241 static unsigned char map[256];
242 static int fake_mode;
243 static struct close_me *close_me_head;
244 static const char *cwd;
245 static unsigned last_bg_pid;
246 #if ENABLE_HUSH_INTERACTIVE
247 static int last_jobid;
248 static struct pipe *job_list;
249 /* 'interactive_fd' is a fd# open to ctty, if we have one
250 * _AND_ if we decided to mess with job control */
251 static int interactive_fd;
252 static pid_t saved_task_pgrp;
253 static pid_t saved_tty_pgrp;
255 enum { interactive_fd = 0 };
258 static const char *PS1;
259 static const char *PS2;
260 static struct variables shell_ver = { NULL, "HUSH_VERSION", "0.01", 1, 1 };
261 static struct variables *top_vars = &shell_ver;
264 #define B_CHUNK (100)
274 #define NULL_O_STRING {NULL,0,0,0,0}
275 /* used for initialization:
276 o_string foo = NULL_O_STRING; */
278 /* I can almost use ordinary FILE *. Is open_memstream() universally
279 * available? Where is it documented? */
286 int (*get) (struct in_str *);
287 int (*peek) (struct in_str *);
289 #define b_getch(input) ((input)->get(input))
290 #define b_peek(input) ((input)->peek(input))
292 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
294 struct built_in_command {
295 const char *cmd; /* name */
296 const char *descr; /* description */
297 int (*function) (char **argv); /* function ptr */
300 /* belongs in busybox.h */
301 static int max(int a, int b)
303 return (a > b) ? a : b;
307 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
308 /* broken, of course, but OK for testing */
309 static char *indenter(int i)
311 static char blanks[] = " ";
312 return &blanks[sizeof(blanks) - i - 1];
315 #define debug_printf(...) do {} while (0)
318 #ifdef DEBUG_SHELL_JOBS
319 #define debug_jobs_printf(...) fprintf(stderr, __VA_ARGS__)
321 #define debug_jobs_printf(...) do {} while (0)
324 #define final_printf debug_printf
326 static void __syntax(const char *file, int line)
328 bb_error_msg("syntax error %s:%d", file, line);
330 /* NB: was __FILE__, but that produces full path sometimes, so... */
331 #define syntax() __syntax("hush.c", __LINE__)
333 /* Index of subroutines: */
334 /* function prototypes for builtins */
335 static int builtin_cd(char **argv);
336 static int builtin_env(char **argv);
337 static int builtin_eval(char **argv);
338 static int builtin_exec(char **argv);
339 static int builtin_exit(char **argv);
340 static int builtin_export(char **argv);
341 #if ENABLE_HUSH_INTERACTIVE
342 static int builtin_fg_bg(char **argv);
343 static int builtin_jobs(char **argv);
345 static int builtin_help(char **argv);
346 static int builtin_pwd(char **argv);
347 static int builtin_read(char **argv);
348 static int builtin_set(char **argv);
349 static int builtin_shift(char **argv);
350 static int builtin_source(char **argv);
351 static int builtin_umask(char **argv);
352 static int builtin_unset(char **argv);
353 static int builtin_not_written(char **argv);
354 /* o_string manipulation: */
355 static int b_check_space(o_string *o, int len);
356 static int b_addchr(o_string *o, int ch);
357 static void b_reset(o_string *o);
358 static int b_addqchr(o_string *o, int ch, int quote);
359 static int b_adduint(o_string *o, unsigned i);
360 /* in_str manipulations: */
361 static int static_get(struct in_str *i);
362 static int static_peek(struct in_str *i);
363 static int file_get(struct in_str *i);
364 static int file_peek(struct in_str *i);
365 static void setup_file_in_str(struct in_str *i, FILE *f);
366 static void setup_string_in_str(struct in_str *i, const char *s);
367 /* close_me manipulations: */
368 static void mark_open(int fd);
369 static void mark_closed(int fd);
370 static void close_all(void);
371 /* "run" the final data structures: */
372 static int free_pipe_list(struct pipe *head, int indent);
373 static int free_pipe(struct pipe *pi, int indent);
374 /* really run the final data structures: */
375 static int setup_redirects(struct child_prog *prog, int squirrel[]);
376 static int run_list_real(struct pipe *pi);
377 static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN;
378 static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
379 static int run_pipe_real(struct pipe *pi);
380 /* extended glob support: */
381 static int globhack(const char *src, int flags, glob_t *pglob);
382 static int glob_needed(const char *s);
383 static int xglob(o_string *dest, int flags, glob_t *pglob);
384 /* variable assignment: */
385 static int is_assignment(const char *s);
386 /* data structure manipulation: */
387 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
388 static void initialize_context(struct p_context *ctx);
389 static int done_word(o_string *dest, struct p_context *ctx);
390 static int done_command(struct p_context *ctx);
391 static int done_pipe(struct p_context *ctx, pipe_style type);
392 /* primary string parsing: */
393 static int redirect_dup_num(struct in_str *input);
394 static int redirect_opt_num(o_string *o);
395 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
396 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
397 static const char *lookup_param(const char *src);
398 static char *make_string(char **inp);
399 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
400 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
401 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
403 static int parse_stream_outer(struct in_str *inp, int flag);
404 static int parse_string_outer(const char *s, int flag);
405 static int parse_file_outer(FILE *f);
406 /* job management: */
407 static int checkjobs(struct pipe* fg_pipe);
408 #if ENABLE_HUSH_INTERACTIVE
409 static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
410 static void insert_bg_job(struct pipe *pi);
411 static void remove_bg_job(struct pipe *pi);
412 static void delete_finished_bg_job(struct pipe *pi);
414 int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
416 /* local variable support */
417 static char **make_list_in(char **inp, char *name);
418 static char *insert_var_value(char *inp);
419 static const char *get_local_var(const char *var);
420 static int set_local_var(const char *s, int flg_export);
421 static void unset_local_var(const char *name);
423 /* Table of built-in functions. They can be forked or not, depending on
424 * context: within pipes, they fork. As simple commands, they do not.
425 * When used in non-forking context, they can change global variables
426 * in the parent shell process. If forked, of course they cannot.
427 * For example, 'unset foo | whatever' will parse and run, but foo will
428 * still be set at the end. */
429 static const struct built_in_command bltins[] = {
430 #if ENABLE_HUSH_INTERACTIVE
431 { "bg", "Resume a job in the background", builtin_fg_bg },
433 { "break", "Exit for, while or until loop", builtin_not_written },
434 { "cd", "Change working directory", builtin_cd },
435 { "continue", "Continue for, while or until loop", builtin_not_written },
436 { "env", "Print all environment variables", builtin_env },
437 { "eval", "Construct and run shell command", builtin_eval },
438 { "exec", "Exec command, replacing this shell with the exec'd process",
440 { "exit", "Exit from shell()", builtin_exit },
441 { "export", "Set environment variable", builtin_export },
442 #if ENABLE_HUSH_INTERACTIVE
443 { "fg", "Bring job into the foreground", builtin_fg_bg },
444 { "jobs", "Lists the active jobs", builtin_jobs },
446 { "pwd", "Print current directory", builtin_pwd },
447 { "read", "Input environment variable", builtin_read },
448 { "return", "Return from a function", builtin_not_written },
449 { "set", "Set/unset shell local variables", builtin_set },
450 { "shift", "Shift positional parameters", builtin_shift },
451 { "trap", "Trap signals", builtin_not_written },
452 { "ulimit","Controls resource limits", builtin_not_written },
453 { "umask","Sets file creation mask", builtin_umask },
454 { "unset", "Unset environment variable", builtin_unset },
455 { ".", "Source-in and run commands in a file", builtin_source },
456 { "help", "List shell built-in commands", builtin_help },
460 #if ENABLE_HUSH_INTERACTIVE
462 #if ENABLE_FEATURE_SH_STANDALONE
464 static void signal_SA_RESTART(int sig, void (*handler)(int))
467 sa.sa_handler = handler;
468 sa.sa_flags = SA_RESTART;
469 sigemptyset(&sa.sa_mask);
470 sigaction(sig, &sa, NULL);
474 /* Signals are grouped, we handle them in batches */
475 static void set_fatal_sighandler(void (*handler)(int))
477 signal(SIGILL , handler);
478 signal(SIGTRAP, handler);
479 signal(SIGABRT, handler);
480 signal(SIGFPE , handler);
481 signal(SIGBUS , handler);
482 signal(SIGSEGV, handler);
483 /* bash 3.2 seems to handle these just like 'fatal' ones */
484 signal(SIGHUP , handler);
485 signal(SIGPIPE, handler);
486 signal(SIGALRM, handler);
488 static void set_jobctrl_sighandler(void (*handler)(int))
490 signal(SIGTSTP, handler);
491 signal(SIGTTIN, handler);
492 signal(SIGTTOU, handler);
494 static void set_misc_sighandler(void (*handler)(int))
496 signal(SIGINT , handler);
497 signal(SIGQUIT, handler);
498 signal(SIGTERM, handler);
500 /* SIGCHLD is special and handled separately */
502 #if ENABLE_FEATURE_SH_STANDALONE
503 static void set_every_sighandler(void (*handler)(int))
505 set_fatal_sighandler(handler);
506 set_jobctrl_sighandler(handler);
507 set_misc_sighandler(handler);
508 signal(SIGCHLD, handler);
511 static struct pipe *nofork_pipe;
512 struct nofork_save_area nofork_save;
513 static sigjmp_buf nofork_jb;
515 static void handler_ctrl_c(int sig)
517 debug_jobs_printf("got sig %d\n", sig);
518 // as usual we can have all kinds of nasty problems with leaked malloc data here
519 siglongjmp(nofork_jb, 1);
522 static void handler_ctrl_z(int sig)
526 debug_jobs_printf("got tty sig %d\n", sig);
528 if (pid < 0) /* can't fork. Pretend there were no Ctrl-Z */
530 debug_jobs_printf("bg'ing nofork\n");
531 nofork_save.saved = 0; /* flag the fact that Ctrl-Z was handled */
532 nofork_pipe->running_progs = 1;
533 nofork_pipe->stopped_progs = 0;
534 if (!pid) { /* child */
535 debug_jobs_printf("setting pgrp for child\n");
537 set_every_sighandler(SIG_DFL);
538 raise(SIGTSTP); /* resend TSTP so that child will be stopped */
539 debug_jobs_printf("returning to child\n");
540 /* return to nofork, it will eventually exit now,
541 * not return back to shell */
545 /* finish filling up pipe info */
546 nofork_pipe->pgrp = pid; /* child is in its own pgrp */
547 nofork_pipe->progs[0].pid = pid;
548 nofork_pipe->running_progs = 1;
549 nofork_pipe->stopped_progs = 0;
550 /* parent needs to longjmp out of running nofork.
551 * we will "return" exitcode 0, with child put in background */
552 // as usual we can have all kinds of nasty problems with leaked malloc data here
553 siglongjmp(nofork_jb, 1);
558 /* Restores tty foreground process group, and exits.
559 * May be called as signal handler for fatal signal
560 * (will faithfully resend signal to itself, producing correct exit state)
561 * or called directly with -EXITCODE.
562 * We also call it if xfunc is exiting. */
563 static void sigexit(int sig) ATTRIBUTE_NORETURN;
564 static void sigexit(int sig)
568 /* Disable all signals: job control, SIGPIPE, etc. */
569 sigfillset(&block_all);
570 sigprocmask(SIG_SETMASK, &block_all, NULL);
573 tcsetpgrp(interactive_fd, saved_tty_pgrp);
575 /* Not a signal, just exit */
579 /* Enable only this sig and kill ourself with it */
580 signal(sig, SIG_DFL);
581 sigdelset(&block_all, sig);
582 sigprocmask(SIG_SETMASK, &block_all, NULL);
584 _exit(1); /* Should not reach it */
587 /* Restores tty foreground process group, and exits. */
588 static void hush_exit(int exitcode) ATTRIBUTE_NORETURN;
589 static void hush_exit(int exitcode)
591 fflush(NULL); /* flush all streams */
592 sigexit(- (exitcode & 0xff));
595 #else /* !INTERACTIVE */
597 #define set_fatal_sighandler(handler) ((void)0)
598 #define set_jobctrl_sighandler(handler) ((void)0)
599 #define set_misc_sighandler(handler) ((void)0)
600 #define hush_exit(e) exit(-(e))
602 #endif /* INTERACTIVE */
605 static const char *set_cwd(void)
607 if (cwd == bb_msg_unknown)
608 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
609 cwd = xrealloc_getcwd_or_warn((char *)cwd);
611 cwd = bb_msg_unknown;
615 /* built-in 'eval' handler */
616 static int builtin_eval(char **argv)
619 int rcode = EXIT_SUCCESS;
622 str = make_string(argv + 1);
623 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
624 FLAG_PARSE_SEMICOLON);
626 rcode = last_return_code;
631 /* built-in 'cd <path>' handler */
632 static int builtin_cd(char **argv)
636 newdir = getenv("HOME");
640 printf("cd: %s: %s\n", newdir, strerror(errno));
647 /* built-in 'env' handler */
648 static int builtin_env(char **argv ATTRIBUTE_UNUSED)
650 /* TODO: call env applet's code instead */
660 /* built-in 'exec' handler */
661 static int builtin_exec(char **argv)
664 return EXIT_SUCCESS; /* Really? */
665 pseudo_exec_argv(argv + 1);
669 /* built-in 'exit' handler */
670 static int builtin_exit(char **argv)
672 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
673 //puts("exit"); /* bash does it */
676 hush_exit(last_return_code);
677 /* mimic bash: exit 123abc == exit 255 + error msg */
678 xfunc_error_retval = 255;
679 /* bash: exit -2 == exit 254, no error msg */
680 hush_exit(xatoi(argv[1]));
683 /* built-in 'export VAR=value' handler */
684 static int builtin_export(char **argv)
687 char *name = argv[1];
690 return builtin_env(argv);
696 const char *value = strchr(name, '=');
700 /* They are exporting something without an =VALUE */
702 value = get_local_var(name);
704 size_t ln = strlen(name);
706 tmp = realloc(name, ln+strlen(value)+2);
710 sprintf(tmp+ln, "=%s", value);
714 /* bash does not return an error when trying to export
715 * an undefined variable. Do likewise. */
721 bb_perror_msg("export");
723 res = set_local_var(name, 1);
730 #if ENABLE_HUSH_INTERACTIVE
731 /* built-in 'fg' and 'bg' handler */
732 static int builtin_fg_bg(char **argv)
739 /* If they gave us no args, assume they want the last backgrounded task */
741 for (pi = job_list; pi; pi = pi->next) {
742 if (pi->jobid == last_jobid) {
746 bb_error_msg("%s: no current job", argv[0]);
749 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
750 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
753 for (pi = job_list; pi; pi = pi->next) {
754 if (pi->jobid == jobnum) {
758 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
761 // TODO: bash prints a string representation
762 // of job being foregrounded (like "sleep 1 | cat")
763 if (*argv[0] == 'f') {
764 /* Put the job into the foreground. */
765 tcsetpgrp(interactive_fd, pi->pgrp);
768 /* Restart the processes in the job */
769 debug_jobs_printf("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
770 for (i = 0; i < pi->num_progs; i++) {
771 debug_jobs_printf("reviving pid %d\n", pi->progs[i].pid);
772 pi->progs[i].is_stopped = 0;
774 pi->stopped_progs = 0;
776 i = kill(- pi->pgrp, SIGCONT);
778 if (errno == ESRCH) {
779 delete_finished_bg_job(pi);
782 bb_perror_msg("kill (SIGCONT)");
786 if (*argv[0] == 'f') {
788 return checkjobs_and_fg_shell(pi);
794 /* built-in 'help' handler */
795 static int builtin_help(char **argv ATTRIBUTE_UNUSED)
797 const struct built_in_command *x;
799 printf("\nBuilt-in commands:\n");
800 printf("-------------------\n");
801 for (x = bltins; x->cmd; x++) {
802 if (x->descr == NULL)
804 printf("%s\t%s\n", x->cmd, x->descr);
810 #if ENABLE_HUSH_INTERACTIVE
811 /* built-in 'jobs' handler */
812 static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
815 const char *status_string;
817 for (job = job_list; job; job = job->next) {
818 if (job->running_progs == job->stopped_progs)
819 status_string = "Stopped";
821 status_string = "Running";
823 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
829 /* built-in 'pwd' handler */
830 static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
836 /* built-in 'read VAR' handler */
837 static int builtin_read(char **argv)
845 string[0] = '\0'; /* In case stdin has only EOF */
847 fgets(string, sizeof(string), stdin);
849 var = malloc(strlen(argv[1]) + strlen(string) + 2);
851 sprintf(var, "%s=%s", argv[1], string);
852 res = set_local_var(var, 0);
856 bb_perror_msg("read");
857 free(var); /* So not move up to avoid breaking errno */
860 do res = getchar(); while (res != '\n' && res != EOF);
864 /* built-in 'set VAR=value' handler */
865 static int builtin_set(char **argv)
867 char *temp = argv[1];
871 for (e = top_vars; e; e = e->next)
872 printf("%s=%s\n", e->name, e->value);
874 set_local_var(temp, 0);
880 /* Built-in 'shift' handler */
881 static int builtin_shift(char **argv)
887 if (n >= 0 && n < global_argc) {
888 /* XXX This probably breaks $0 */
896 /* Built-in '.' handler (read-in and execute commands from file) */
897 static int builtin_source(char **argv)
905 /* XXX search through $PATH is missing */
906 input = fopen(argv[1], "r");
908 bb_error_msg("cannot open '%s'", argv[1]);
912 /* Now run the file */
913 /* XXX argv and argc are broken; need to save old global_argv
914 * (pointer only is OK!) on this stack frame,
915 * set global_argv=argv+1, recurse, and restore. */
916 mark_open(fileno(input));
917 status = parse_file_outer(input);
918 mark_closed(fileno(input));
923 static int builtin_umask(char **argv)
926 const char *arg = argv[1];
929 new_umask = strtoul(arg, &end, 8);
930 if (*end != '\0' || end == arg) {
934 new_umask = umask(0);
935 printf("%.3o\n", (unsigned) new_umask);
941 /* built-in 'unset VAR' handler */
942 static int builtin_unset(char **argv)
944 /* bash returned already true */
945 unset_local_var(argv[1]);
949 static int builtin_not_written(char **argv)
951 printf("builtin_%s not written\n", argv[0]);
955 static int b_check_space(o_string *o, int len)
957 /* It would be easy to drop a more restrictive policy
958 * in here, such as setting a maximum string length */
959 if (o->length + len > o->maxlen) {
960 char *old_data = o->data;
961 /* assert(data == NULL || o->maxlen != 0); */
962 o->maxlen += max(2*len, B_CHUNK);
963 o->data = realloc(o->data, 1 + o->maxlen);
964 if (o->data == NULL) {
968 return o->data == NULL;
971 static int b_addchr(o_string *o, int ch)
973 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
974 if (b_check_space(o, 1))
976 o->data[o->length] = ch;
978 o->data[o->length] = '\0';
982 static void b_reset(o_string *o)
990 static void b_free(o_string *o)
998 /* My analysis of quoting semantics tells me that state information
999 * is associated with a destination, not a source.
1001 static int b_addqchr(o_string *o, int ch, int quote)
1003 if (quote && strchr("*?[\\", ch)) {
1005 rc = b_addchr(o, '\\');
1009 return b_addchr(o, ch);
1012 static int b_adduint(o_string *o, unsigned i)
1015 char buf[sizeof(unsigned)*3 + 1];
1017 *(utoa_to_buf(i, buf, sizeof(buf))) = '\0';
1018 /* no escape checking necessary */
1019 do r = b_addchr(o, *p++); while (r == 0 && *p);
1023 static int static_get(struct in_str *i)
1026 if (ch == '\0') return EOF;
1030 static int static_peek(struct in_str *i)
1035 static void cmdedit_set_initial_prompt(void)
1037 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1040 PS1 = getenv("PS1");
1046 static const char* setup_prompt_string(int promptmode)
1048 const char *prompt_str;
1049 debug_printf("setup_prompt_string %d ", promptmode);
1050 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1051 /* Set up the prompt */
1052 if (promptmode == 1) {
1055 ns = xmalloc(strlen(cwd)+4);
1056 sprintf(ns, "%s %s", cwd, (geteuid() != 0) ? "$ " : "# ");
1063 prompt_str = (promptmode == 1) ? PS1 : PS2;
1065 debug_printf("result %s\n", prompt_str);
1069 #if ENABLE_FEATURE_EDITING
1070 static line_input_t *line_input_state;
1073 static int get_user_input(struct in_str *i)
1076 const char *prompt_str;
1077 static char the_command[BUFSIZ];
1079 prompt_str = setup_prompt_string(i->promptmode);
1080 #if ENABLE_FEATURE_EDITING
1082 ** enable command line editing only while a command line
1083 ** is actually being read; otherwise, we'll end up bequeathing
1084 ** atexit() handlers and other unwanted stuff to our
1085 ** child processes (rob@sysgo.de)
1087 r = read_line_input(prompt_str, the_command, BUFSIZ, line_input_state);
1089 fputs(prompt_str, stdout);
1091 the_command[0] = r = fgetc(i->file);
1092 the_command[1] = '\0';
1096 return r; /* < 0 == EOF. Not meaningful otherwise */
1099 /* This is the magic location that prints prompts
1100 * and gets data back from the user */
1101 static int file_get(struct in_str *i)
1106 /* If there is data waiting, eat it up */
1107 if (i->p && *i->p) {
1110 /* need to double check i->file because we might be doing something
1111 * more complicated by now, like sourcing or substituting. */
1112 if (i->__promptme && interactive_fd && i->file == stdin) {
1113 while (!i->p || !(interactive_fd && i->p[0])) {
1114 if (get_user_input(i) < 0)
1119 if (i->p && *i->p) {
1123 ch = fgetc(i->file);
1126 debug_printf("b_getch: got a %d\n", ch);
1133 /* All the callers guarantee this routine will never be
1134 * used right after a newline, so prompting is not needed.
1136 static int file_peek(struct in_str *i)
1138 if (i->p && *i->p) {
1141 i->peek_buf[0] = fgetc(i->file);
1142 i->peek_buf[1] = '\0';
1144 debug_printf("b_peek: got a %d\n", *i->p);
1148 static void setup_file_in_str(struct in_str *i, FILE *f)
1150 i->peek = file_peek;
1158 static void setup_string_in_str(struct in_str *i, const char *s)
1160 i->peek = static_peek;
1161 i->get = static_get;
1167 static void mark_open(int fd)
1169 struct close_me *new = xmalloc(sizeof(struct close_me));
1171 new->next = close_me_head;
1172 close_me_head = new;
1175 static void mark_closed(int fd)
1177 struct close_me *tmp;
1178 if (close_me_head == NULL || close_me_head->fd != fd)
1179 bb_error_msg_and_die("corrupt close_me");
1180 tmp = close_me_head;
1181 close_me_head = close_me_head->next;
1185 static void close_all(void)
1188 for (c = close_me_head; c; c = c->next) {
1191 close_me_head = NULL;
1194 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1195 * and stderr if they are redirected. */
1196 static int setup_redirects(struct child_prog *prog, int squirrel[])
1199 struct redir_struct *redir;
1201 for (redir = prog->redirects; redir; redir = redir->next) {
1202 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1203 /* something went wrong in the parse. Pretend it didn't happen */
1206 if (redir->dup == -1) {
1207 mode = redir_table[redir->type].mode;
1208 openfd = open_or_warn(redir->word.gl_pathv[0], mode);
1210 /* this could get lost if stderr has been redirected, but
1211 bash and ash both lose it as well (though zsh doesn't!) */
1215 openfd = redir->dup;
1218 if (openfd != redir->fd) {
1219 if (squirrel && redir->fd < 3) {
1220 squirrel[redir->fd] = dup(redir->fd);
1225 dup2(openfd, redir->fd);
1226 if (redir->dup == -1)
1234 static void restore_redirects(int squirrel[])
1237 for (i = 0; i < 3; i++) {
1240 /* No error checking. I sure wouldn't know what
1241 * to do with an error if I found one! */
1249 /* XXX no exit() here. If you don't exec, use _exit instead.
1250 * The at_exit handlers apparently confuse the calling process,
1251 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
1252 static void pseudo_exec_argv(char **argv)
1256 const struct built_in_command *x;
1258 for (i = 0; is_assignment(argv[i]); i++) {
1259 debug_printf("pid %d environment modification: %s\n",
1261 // FIXME: vfork case??
1262 p = insert_var_value(argv[i]);
1268 /* If a variable is assigned in a forest, and nobody listens,
1269 * was it ever really set?
1271 if (argv[0] == NULL) {
1272 _exit(EXIT_SUCCESS);
1276 * Check if the command matches any of the builtins.
1277 * Depending on context, this might be redundant. But it's
1278 * easier to waste a few CPU cycles than it is to figure out
1279 * if this is one of those cases.
1281 for (x = bltins; x->cmd; x++) {
1282 if (strcmp(argv[0], x->cmd) == 0) {
1283 debug_printf("builtin exec %s\n", argv[0]);
1284 rcode = x->function(argv);
1290 /* Check if the command matches any busybox internal commands
1292 * FIXME: This feature is not 100% safe, since
1293 * BusyBox is not fully reentrant, so we have no guarantee the things
1294 * from the .bss are still zeroed, or that things from .data are still
1295 * at their defaults. We could exec ourself from /proc/self/exe, but I
1296 * really dislike relying on /proc for things. We could exec ourself
1297 * from global_argv[0], but if we are in a chroot, we may not be able
1298 * to find ourself... */
1299 #if ENABLE_FEATURE_SH_STANDALONE
1300 debug_printf("running applet %s\n", argv[0]);
1301 run_applet_and_exit(argv[0], argv);
1302 // is it ok that run_applet_and_exit() does exit(), not _exit()?
1303 // NB: IIRC on NOMMU we are after _vfork_, not fork!
1305 debug_printf("exec of %s\n", argv[0]);
1306 execvp(argv[0], argv);
1307 bb_perror_msg("cannot exec '%s'", argv[0]);
1311 static void pseudo_exec(struct child_prog *child)
1316 pseudo_exec_argv(child->argv);
1320 debug_printf("runtime nesting to group\n");
1321 // FIXME: do not modify globals! Think vfork!
1322 #if ENABLE_HUSH_INTERACTIVE
1323 interactive_fd = 0; /* crucial!!!! */
1325 rcode = run_list_real(child->group);
1326 /* OK to leak memory by not calling free_pipe_list,
1327 * since this process is about to exit */
1331 /* Can happen. See what bash does with ">foo" by itself. */
1332 debug_printf("trying to pseudo_exec null command\n");
1333 _exit(EXIT_SUCCESS);
1336 #if ENABLE_HUSH_INTERACTIVE
1337 static const char *get_cmdtext(struct pipe *pi)
1343 /* This is subtle. ->cmdtext is created only on first backgrounding.
1344 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
1345 * On subsequent bg argv can be trashed, but we won't use it */
1348 argv = pi->progs[0].argv;
1349 if (!argv || !argv[0])
1350 return (pi->cmdtext = xzalloc(1));
1353 do len += strlen(*argv) + 1; while (*++argv);
1354 pi->cmdtext = p = xmalloc(len);
1355 argv = pi->progs[0].argv;
1357 len = strlen(*argv);
1358 memcpy(p, *argv, len);
1367 #if ENABLE_HUSH_INTERACTIVE
1368 static void insert_bg_job(struct pipe *pi)
1370 struct pipe *thejob;
1372 /* Linear search for the ID of the job to use */
1374 for (thejob = job_list; thejob; thejob = thejob->next)
1375 if (thejob->jobid >= pi->jobid)
1376 pi->jobid = thejob->jobid + 1;
1378 /* add thejob to the list of running jobs */
1380 thejob = job_list = xmalloc(sizeof(*thejob));
1382 for (thejob = job_list; thejob->next; thejob = thejob->next)
1384 thejob->next = xmalloc(sizeof(*thejob));
1385 thejob = thejob->next;
1388 /* physically copy the struct job */
1389 memcpy(thejob, pi, sizeof(struct pipe));
1390 thejob->progs = xmalloc(sizeof(pi->progs[0]) * pi->num_progs);
1391 memcpy(thejob->progs, pi->progs, sizeof(pi->progs[0]) * pi->num_progs);
1392 thejob->next = NULL;
1393 /*seems to be wrong:*/
1394 /*thejob->running_progs = thejob->num_progs;*/
1395 /*thejob->stopped_progs = 0;*/
1396 thejob->cmdtext = xstrdup(get_cmdtext(pi));
1398 /* we don't wait for background thejobs to return -- append it
1399 to the list of backgrounded thejobs and leave it alone */
1400 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
1401 last_bg_pid = thejob->progs[0].pid;
1402 last_jobid = thejob->jobid;
1405 static void remove_bg_job(struct pipe *pi)
1407 struct pipe *prev_pipe;
1409 if (pi == job_list) {
1410 job_list = pi->next;
1412 prev_pipe = job_list;
1413 while (prev_pipe->next != pi)
1414 prev_pipe = prev_pipe->next;
1415 prev_pipe->next = pi->next;
1418 last_jobid = job_list->jobid;
1423 /* remove a backgrounded job */
1424 static void delete_finished_bg_job(struct pipe *pi)
1427 pi->stopped_progs = 0;
1433 /* Checks to see if any processes have exited -- if they
1434 have, figure out why and see if a job has completed */
1435 static int checkjobs(struct pipe* fg_pipe)
1439 #if ENABLE_HUSH_INTERACTIVE
1446 attributes = WUNTRACED;
1447 if (fg_pipe == NULL) {
1448 attributes |= WNOHANG;
1451 /* Do we do this right?
1452 * bash-3.00# sleep 20 | false
1454 * [3]+ Stopped sleep 20 | false
1455 * bash-3.00# echo $?
1456 * 1 <========== bg pipe is not fully done, but exitcode is already known!
1459 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
1460 //are stopped. Testcase: "cat | cat" in a script (not on command line)
1461 // + killall -STOP cat
1464 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1465 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
1467 #ifdef DEBUG_SHELL_JOBS
1468 if (WIFSTOPPED(status))
1469 debug_jobs_printf("pid %d stopped by sig %d (exitcode %d)\n",
1470 childpid, WSTOPSIG(status), WEXITSTATUS(status));
1471 if (WIFSIGNALED(status))
1472 debug_jobs_printf("pid %d killed by sig %d (exitcode %d)\n",
1473 childpid, WTERMSIG(status), WEXITSTATUS(status));
1474 if (WIFEXITED(status))
1475 debug_jobs_printf("pid %d exited, exitcode %d\n",
1476 childpid, WEXITSTATUS(status));
1478 /* Were we asked to wait for fg pipe? */
1481 for (i = 0; i < fg_pipe->num_progs; i++) {
1482 debug_jobs_printf("check pid %d\n", fg_pipe->progs[i].pid);
1483 if (fg_pipe->progs[i].pid == childpid) {
1484 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
1486 fg_pipe->progs[i].pid = 0;
1487 fg_pipe->running_progs--;
1488 if (i == fg_pipe->num_progs-1)
1489 /* last process gives overall exitstatus */
1490 rcode = WEXITSTATUS(status);
1492 fg_pipe->progs[i].is_stopped = 1;
1493 fg_pipe->stopped_progs++;
1495 debug_jobs_printf("fg_pipe: running_progs %d stopped_progs %d\n",
1496 fg_pipe->running_progs, fg_pipe->stopped_progs);
1497 if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) {
1498 /* All processes in fg pipe have exited/stopped */
1499 #if ENABLE_HUSH_INTERACTIVE
1500 if (fg_pipe->running_progs)
1501 insert_bg_job(fg_pipe);
1505 /* There are still running processes in the fg pipe */
1509 /* fall through to searching process in bg pipes */
1512 #if ENABLE_HUSH_INTERACTIVE
1513 /* We asked to wait for bg or orphaned children */
1514 /* No need to remember exitcode in this case */
1515 for (pi = job_list; pi; pi = pi->next) {
1517 while (prognum < pi->num_progs) {
1518 if (pi->progs[prognum].pid == childpid)
1519 goto found_pi_and_prognum;
1525 /* Happens when shell is used as init process (init=/bin/sh) */
1526 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1529 #if ENABLE_HUSH_INTERACTIVE
1530 found_pi_and_prognum:
1533 pi->progs[prognum].pid = 0;
1534 pi->running_progs--;
1535 if (!pi->running_progs) {
1536 printf(JOB_STATUS_FORMAT, pi->jobid,
1537 "Done", pi->cmdtext);
1538 delete_finished_bg_job(pi);
1542 pi->stopped_progs++;
1543 pi->progs[prognum].is_stopped = 1;
1548 /* wait found no children or failed */
1550 if (childpid && errno != ECHILD)
1551 bb_perror_msg("waitpid");
1553 /* move the shell to the foreground */
1554 //if (interactive_fd && tcsetpgrp(interactive_fd, getpgid(0)))
1555 // bb_perror_msg("tcsetpgrp-2");
1559 #if ENABLE_HUSH_INTERACTIVE
1560 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
1563 int rcode = checkjobs(fg_pipe);
1564 /* Job finished, move the shell to the foreground */
1566 debug_printf("fg'ing ourself: getpgid(0)=%d\n", (int)p);
1567 if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
1568 bb_perror_msg("tcsetpgrp-4a");
1573 #if ENABLE_FEATURE_SH_STANDALONE
1574 /* run_pipe_real's helper */
1575 static int run_single_fg_nofork(struct pipe *pi, const struct bb_applet *a,
1578 #if ENABLE_HUSH_INTERACTIVE
1580 /* TSTP handler will store pid etc in pi */
1582 save_nofork_data(&nofork_save);
1583 if (sigsetjmp(nofork_jb, 1) == 0) {
1584 signal_SA_RESTART(SIGTSTP, handler_ctrl_z);
1585 signal(SIGINT, handler_ctrl_c);
1586 rcode = run_nofork_applet_prime(&nofork_save, a, argv);
1587 if (--nofork_save.saved != 0) {
1588 /* Ctrl-Z forked, we are child */
1593 /* Ctrl-Z forked, we are parent; or Ctrl-C.
1594 * Sighandler has longjmped us here */
1595 signal(SIGINT, SIG_IGN);
1596 signal(SIGTSTP, SIG_IGN);
1597 debug_jobs_printf("Exiting nofork early\n");
1598 restore_nofork_data(&nofork_save);
1599 if (nofork_save.saved == 0) /* Ctrl-Z, not Ctrl-C */
1602 putchar('\n'); /* bash does this on Ctrl-C */
1605 return run_nofork_applet(a, argv);
1610 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1611 * to finish. See checkjobs().
1613 * return code is normally -1, when the caller has to wait for children
1614 * to finish to determine the exit status of the pipe. If the pipe
1615 * is a simple builtin command, however, the action is done by the
1616 * time run_pipe_real returns, and the exit code is provided as the
1619 * The input of the pipe is always stdin, the output is always
1620 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1621 * because it tries to avoid running the command substitution in
1622 * subshell, when that is in fact necessary. The subshell process
1623 * now has its stdout directed to the input of the appropriate pipe,
1624 * so this routine is noticeably simpler.
1626 static int run_pipe_real(struct pipe *pi)
1629 int nextin, nextout;
1630 int pipefds[2]; /* pipefds[0] is for reading */
1631 struct child_prog *child;
1632 const struct built_in_command *x;
1634 /* it is not always needed, but we aim to smaller code */
1635 int squirrel[] = { -1, -1, -1 };
1637 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
1640 #if ENABLE_HUSH_INTERACTIVE
1643 pi->running_progs = 0;
1644 pi->stopped_progs = 0;
1646 /* Check if this is a simple builtin (not part of a pipe).
1647 * Builtins within pipes have to fork anyway, and are handled in
1648 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1650 child = &(pi->progs[0]);
1651 if (single_fg && child->group && child->subshell == 0) {
1652 debug_printf("non-subshell grouping\n");
1653 setup_redirects(child, squirrel);
1654 /* XXX could we merge code with following builtin case,
1655 * by creating a pseudo builtin that calls run_list_real? */
1656 rcode = run_list_real(child->group);
1657 restore_redirects(squirrel);
1661 if (single_fg && child->argv != NULL) {
1662 char **argv = child->argv;
1664 for (i = 0; is_assignment(argv[i]); i++)
1666 if (i != 0 && argv[i] == NULL) {
1667 /* assignments, but no command: set the local environment */
1668 for (i = 0; argv[i] != NULL; i++) {
1669 /* Ok, this case is tricky. We have to decide if this is a
1670 * local variable, or an already exported variable. If it is
1671 * already exported, we have to export the new value. If it is
1672 * not exported, we need only set this as a local variable.
1673 * This junk is all to decide whether or not to export this
1677 name = xstrdup(argv[i]);
1678 debug_printf("Local environment set: %s\n", name);
1679 value = strchr(name, '=');
1682 if (get_local_var(name)) {
1686 p = insert_var_value(argv[i]);
1687 set_local_var(p, export_me);
1691 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1693 for (i = 0; is_assignment(argv[i]); i++) {
1694 p = insert_var_value(argv[i]);
1704 str = make_string(argv + i);
1705 parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1707 return last_return_code;
1709 for (x = bltins; x->cmd; x++) {
1710 if (strcmp(argv[i], x->cmd) == 0) {
1711 if (x->function == builtin_exec && argv[i+1] == NULL) {
1712 debug_printf("magic exec\n");
1713 setup_redirects(child, NULL);
1714 return EXIT_SUCCESS;
1716 debug_printf("builtin inline %s\n", argv[0]);
1717 /* XXX setup_redirects acts on file descriptors, not FILEs.
1718 * This is perfect for work that comes after exec().
1719 * Is it really safe for inline use? Experimentally,
1720 * things seem to work with glibc. */
1721 // TODO: fflush(NULL)?
1722 setup_redirects(child, squirrel);
1723 rcode = x->function(argv + i);
1724 restore_redirects(squirrel);
1728 #if ENABLE_FEATURE_SH_STANDALONE
1730 const struct bb_applet *a = find_applet_by_name(argv[i]);
1731 if (a && a->nofork) {
1732 setup_redirects(child, squirrel);
1733 rcode = run_single_fg_nofork(pi, a, argv + i);
1734 restore_redirects(squirrel);
1741 /* Going to fork a child per each pipe member */
1743 /* Disable job control signals for shell (parent) and
1744 * for initial child code after fork */
1745 set_jobctrl_sighandler(SIG_IGN);
1747 for (i = 0; i < pi->num_progs; i++) {
1748 child = &(pi->progs[i]);
1750 /* pipes are inserted between pairs of commands */
1751 if ((i + 1) < pi->num_progs) {
1752 if (pipe(pipefds) < 0)
1753 bb_perror_msg_and_die("pipe");
1754 nextout = pipefds[1];
1760 /* XXX test for failed fork()? */
1762 child->pid = fork();
1764 child->pid = vfork();
1766 if (!child->pid) { /* child */
1767 /* Every child adds itself to new process group
1768 * with pgid == pid of first child in pipe */
1769 #if ENABLE_HUSH_INTERACTIVE
1770 if (interactive_fd) {
1771 /* Don't do pgrp restore anymore on fatal signals */
1772 set_fatal_sighandler(SIG_DFL);
1773 if (pi->pgrp < 0) /* true for 1st process only */
1774 pi->pgrp = getpid();
1775 if (setpgid(0, pi->pgrp) == 0 && pi->followup != PIPE_BG) {
1776 /* We do it in *every* child, not just first,
1778 tcsetpgrp(interactive_fd, pi->pgrp);
1782 // in non-interactive case fatal sigs are already SIG_DFL
1792 if (pipefds[0] != -1) {
1793 close(pipefds[0]); /* opposite end of our output pipe */
1795 /* Like bash, explicit redirects override pipes,
1796 * and the pipe fd is available for dup'ing. */
1797 setup_redirects(child, NULL);
1799 /* Restore default handlers just prior to exec */
1800 set_jobctrl_sighandler(SIG_DFL);
1801 set_misc_sighandler(SIG_DFL);
1802 signal(SIGCHLD, SIG_DFL);
1806 pi->running_progs++;
1808 #if ENABLE_HUSH_INTERACTIVE
1809 /* Second and next children need to know pid of first one */
1811 pi->pgrp = child->pid;
1814 /* Don't check for errors. The child may be dead already,
1815 * in which case setpgid returns error code EACCES. */
1816 //why we do it at all?? child does it itself
1817 //if (interactive_fd)
1818 // setpgid(child->pid, pi->pgrp);
1825 /* If there isn't another process, nextin is garbage
1826 but it doesn't matter */
1827 nextin = pipefds[0];
1832 static int run_list_real(struct pipe *pi)
1834 char *save_name = NULL;
1836 char **save_list = NULL;
1840 int rcode = 0, flag_skip = 1;
1841 int flag_restore = 0;
1842 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
1843 reserved_style rmode, skip_more_in_this_rmode = RES_XXXX;
1844 /* check syntax for "for" */
1845 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1846 if ((rpipe->r_mode == RES_IN || rpipe->r_mode == RES_FOR)
1847 && (rpipe->next == NULL)
1852 if ((rpipe->r_mode == RES_IN && rpipe->next->r_mode == RES_IN && rpipe->next->progs->argv != NULL)
1853 || (rpipe->r_mode == RES_FOR && rpipe->next->r_mode != RES_IN)
1859 for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1860 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL
1861 || pi->r_mode == RES_FOR
1870 debug_printf("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n",
1871 rmode, if_code, next_if_code, skip_more_in_this_rmode);
1872 if (rmode == skip_more_in_this_rmode && flag_skip) {
1873 if (pi->followup == PIPE_SEQ)
1878 skip_more_in_this_rmode = RES_XXXX;
1879 if (rmode == RES_THEN || rmode == RES_ELSE)
1880 if_code = next_if_code;
1881 if (rmode == RES_THEN && if_code)
1883 if (rmode == RES_ELSE && !if_code)
1885 if (rmode == RES_ELIF && !if_code)
1887 if (rmode == RES_FOR && pi->num_progs) {
1889 /* if no variable values after "in" we skip "for" */
1890 if (!pi->next->progs->argv)
1892 /* create list of variable values */
1893 list = make_list_in(pi->next->progs->argv,
1894 pi->progs->argv[0]);
1896 save_name = pi->progs->argv[0];
1897 pi->progs->argv[0] = NULL;
1901 free(pi->progs->argv[0]);
1905 pi->progs->argv[0] = save_name;
1906 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
1909 /* insert new value from list for variable */
1910 if (pi->progs->argv[0])
1911 free(pi->progs->argv[0]);
1912 pi->progs->argv[0] = *list++;
1913 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
1915 if (rmode == RES_IN)
1917 if (rmode == RES_DO) {
1921 if (rmode == RES_DONE) {
1928 if (pi->num_progs == 0)
1930 save_num_progs = pi->num_progs; /* save number of programs */
1931 rcode = run_pipe_real(pi);
1932 debug_printf("run_pipe_real returned %d\n", rcode);
1934 /* We only ran a builtin: rcode was set by the return value
1935 * of run_pipe_real(), and we don't need to wait for anything. */
1936 } else if (pi->followup == PIPE_BG) {
1937 /* XXX check bash's behavior with nontrivial pipes */
1938 /* XXX compute jobid */
1939 /* XXX what does bash do with attempts to background builtins? */
1940 #if ENABLE_HUSH_INTERACTIVE
1943 rcode = EXIT_SUCCESS;
1945 if (interactive_fd) {
1946 rcode = checkjobs_and_fg_shell(pi);
1948 rcode = checkjobs(pi);
1950 debug_printf("checkjobs returned %d\n", rcode);
1952 last_return_code = rcode;
1953 pi->num_progs = save_num_progs; /* restore number of programs */
1954 if (rmode == RES_IF || rmode == RES_ELIF)
1955 next_if_code = rcode; /* can be overwritten a number of times */
1956 if (rmode == RES_WHILE)
1957 flag_rep = !last_return_code;
1958 if (rmode == RES_UNTIL)
1959 flag_rep = last_return_code;
1960 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
1961 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
1963 skip_more_in_this_rmode = rmode;
1970 /* return code is the exit status of the pipe */
1971 static int free_pipe(struct pipe *pi, int indent)
1974 struct child_prog *child;
1975 struct redir_struct *r, *rnext;
1976 int a, i, ret_code = 0;
1978 if (pi->stopped_progs > 0)
1980 final_printf("%s run pipe: (pid %d)\n", indenter(indent), getpid());
1981 for (i = 0; i < pi->num_progs; i++) {
1982 child = &pi->progs[i];
1983 final_printf("%s command %d:\n", indenter(indent), i);
1985 for (a = 0, p = child->argv; *p; a++, p++) {
1986 final_printf("%s argv[%d] = %s\n", indenter(indent), a, *p);
1988 globfree(&child->glob_result);
1990 } else if (child->group) {
1991 final_printf("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
1992 ret_code = free_pipe_list(child->group, indent+3);
1993 final_printf("%s end group\n", indenter(indent));
1995 final_printf("%s (nil)\n", indenter(indent));
1997 for (r = child->redirects; r; r = rnext) {
1998 final_printf("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
2000 /* guard against the case >$FOO, where foo is unset or blank */
2001 if (r->word.gl_pathv) {
2002 final_printf(" %s\n", *r->word.gl_pathv);
2006 final_printf("&%d\n", r->dup);
2011 child->redirects = NULL;
2013 free(pi->progs); /* children are an array, they get freed all at once */
2015 #if ENABLE_HUSH_INTERACTIVE
2022 static int free_pipe_list(struct pipe *head, int indent)
2024 int rcode = 0; /* if list has no members */
2025 struct pipe *pi, *next;
2026 for (pi = head; pi; pi = next) {
2027 final_printf("%s pipe reserved mode %d\n", indenter(indent), pi->r_mode);
2028 rcode = free_pipe(pi, indent);
2029 final_printf("%s pipe followup code %d\n", indenter(indent), pi->followup);
2031 /*pi->next = NULL;*/
2037 /* Select which version we will use */
2038 static int run_list(struct pipe *pi)
2041 if (fake_mode == 0) {
2042 rcode = run_list_real(pi);
2044 /* free_pipe_list has the side effect of clearing memory
2045 * In the long run that function can be merged with run_list_real,
2046 * but doing that now would hobble the debugging effort. */
2047 free_pipe_list(pi,0);
2051 /* The API for glob is arguably broken. This routine pushes a non-matching
2052 * string into the output structure, removing non-backslashed backslashes.
2053 * If someone can prove me wrong, by performing this function within the
2054 * original glob(3) api, feel free to rewrite this routine into oblivion.
2055 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2056 * XXX broken if the last character is '\\', check that before calling.
2058 static int globhack(const char *src, int flags, glob_t *pglob)
2063 for (cnt = 1, s = src; s && *s; s++) {
2064 if (*s == '\\') s++;
2069 return GLOB_NOSPACE;
2070 if (!(flags & GLOB_APPEND)) {
2071 pglob->gl_pathv = NULL;
2072 pglob->gl_pathc = 0;
2076 pathc = ++pglob->gl_pathc;
2077 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2078 if (pglob->gl_pathv == NULL)
2079 return GLOB_NOSPACE;
2080 pglob->gl_pathv[pathc-1] = dest;
2081 pglob->gl_pathv[pathc] = NULL;
2082 for (s = src; s && *s; s++, dest++) {
2083 if (*s == '\\') s++;
2090 /* XXX broken if the last character is '\\', check that before calling */
2091 static int glob_needed(const char *s)
2094 if (*s == '\\') s++;
2095 if (strchr("*[?", *s)) return 1;
2100 static int xglob(o_string *dest, int flags, glob_t *pglob)
2104 /* short-circuit for null word */
2105 /* we can code this better when the debug_printf's are gone */
2106 if (dest->length == 0) {
2107 if (dest->nonnull) {
2108 /* bash man page calls this an "explicit" null */
2109 gr = globhack(dest->data, flags, pglob);
2110 debug_printf("globhack returned %d\n", gr);
2114 } else if (glob_needed(dest->data)) {
2115 gr = glob(dest->data, flags, NULL, pglob);
2116 debug_printf("glob returned %d\n", gr);
2117 if (gr == GLOB_NOMATCH) {
2118 /* quote removal, or more accurately, backslash removal */
2119 gr = globhack(dest->data, flags, pglob);
2120 debug_printf("globhack returned %d\n", gr);
2123 gr = globhack(dest->data, flags, pglob);
2124 debug_printf("globhack returned %d\n", gr);
2126 if (gr == GLOB_NOSPACE)
2127 bb_error_msg_and_die("out of memory during glob");
2128 if (gr != 0) { /* GLOB_ABORTED ? */
2129 bb_error_msg("glob(3) error %d", gr);
2131 /* globprint(glob_target); */
2135 static char **make_list_in(char **inp, char *name)
2138 int name_len = strlen(name);
2143 /* create list of variable values */
2144 list = xmalloc(sizeof(*list));
2145 for (i = 0; inp[i]; i++) {
2146 p3 = insert_var_value(inp[i]);
2153 p2 = strchr(p1, ' ');
2160 /* we use n + 2 in realloc for list, because we add
2161 * new element and then we will add NULL element */
2162 list = xrealloc(list, sizeof(*list) * (n + 2));
2163 list[n] = xmalloc(2 + name_len + len);
2164 strcpy(list[n], name);
2165 strcat(list[n], "=");
2166 strncat(list[n], p1, len);
2167 list[n++][name_len + len + 1] = '\0';
2170 if (p3 != inp[i]) free(p3);
2176 static char *insert_var_value(char *inp)
2178 int res_str_len = 0;
2181 char *p, *res_str = NULL;
2184 while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
2187 res_str = xrealloc(res_str, (res_str_len + len));
2188 strncpy((res_str + res_str_len), inp, len);
2192 p = strchr(inp, SPECIAL_VAR_SYMBOL);
2194 p1 = lookup_param(inp);
2196 len = res_str_len + strlen(p1);
2197 res_str = xrealloc(res_str, (1 + len));
2198 strcpy((res_str + res_str_len), p1);
2201 *p = SPECIAL_VAR_SYMBOL;
2206 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
2207 strcpy((res_str + res_str_len), inp);
2208 while ((p = strchr(res_str, '\n'))) {
2212 return (res_str == NULL) ? inp : res_str;
2215 /* This is used to get/check local shell variables */
2216 static const char *get_local_var(const char *s)
2218 struct variables *cur;
2222 for (cur = top_vars; cur; cur = cur->next)
2223 if (strcmp(cur->name, s) == 0)
2228 /* This is used to set local shell variables
2229 flg_export == 0 if only local (not exporting) variable
2230 flg_export == 1 if "new" exporting environ
2231 flg_export > 1 if current startup environ (not call putenv()) */
2232 static int set_local_var(const char *s, int flg_export)
2236 struct variables *cur;
2240 /* Assume when we enter this function that we are already in
2241 * NAME=VALUE format. So the first order of business is to
2242 * split 's' on the '=' into 'name' and 'value' */
2243 value = strchr(name, '=');
2244 /*if (value == 0 && ++value == 0) ??? -vda */
2245 if (value == NULL || value[1] == '\0') {
2251 for (cur = top_vars; cur; cur = cur->next) {
2252 if (strcmp(cur->name, name) == 0)
2257 if (strcmp(cur->value, value) == 0) {
2258 if (flg_export > 0 && cur->flg_export == 0)
2259 cur->flg_export = flg_export;
2262 } else if (cur->flg_read_only) {
2263 bb_error_msg("%s: readonly variable", name);
2266 if (flg_export > 0 || cur->flg_export > 1)
2267 cur->flg_export = 1;
2268 free((char*)cur->value);
2270 cur->value = strdup(value);
2273 cur = malloc(sizeof(struct variables));
2277 cur->name = strdup(name);
2282 struct variables *bottom = top_vars;
2283 cur->value = strdup(value);
2285 cur->flg_export = flg_export;
2286 cur->flg_read_only = 0;
2287 while (bottom->next)
2288 bottom = bottom->next;
2294 if (result == 0 && cur->flg_export == 1) {
2296 result = putenv(name);
2299 if (result > 0) /* equivalent to previous set */
2305 static void unset_local_var(const char *name)
2307 struct variables *cur, *next;
2311 for (cur = top_vars; cur; cur = cur->next) {
2312 if (strcmp(cur->name, name) == 0) {
2313 if (cur->flg_read_only) {
2314 bb_error_msg("%s: readonly variable", name);
2317 if (cur->flg_export)
2318 unsetenv(cur->name);
2319 free((char*)cur->name);
2320 free((char*)cur->value);
2322 while (next->next != cur)
2324 next->next = cur->next;
2331 static int is_assignment(const char *s)
2333 if (!s || !isalpha(*s))
2336 while (isalnum(*s) || *s == '_')
2341 /* the src parameter allows us to peek forward to a possible &n syntax
2342 * for file descriptor duplication, e.g., "2>&1".
2343 * Return code is 0 normally, 1 if a syntax error is detected in src.
2344 * Resource errors (in xmalloc) cause the process to exit */
2345 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2346 struct in_str *input)
2348 struct child_prog *child = ctx->child;
2349 struct redir_struct *redir = child->redirects;
2350 struct redir_struct *last_redir = NULL;
2352 /* Create a new redir_struct and drop it onto the end of the linked list */
2355 redir = redir->next;
2357 redir = xmalloc(sizeof(struct redir_struct));
2359 redir->word.gl_pathv = NULL;
2361 last_redir->next = redir;
2363 child->redirects = redir;
2366 redir->type = style;
2367 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
2369 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2371 /* Check for a '2>&1' type redirect */
2372 redir->dup = redirect_dup_num(input);
2373 if (redir->dup == -2) return 1; /* syntax error */
2374 if (redir->dup != -1) {
2375 /* Erik had a check here that the file descriptor in question
2376 * is legit; I postpone that to "run time"
2377 * A "-" representation of "close me" shows up as a -3 here */
2378 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2380 /* We do _not_ try to open the file that src points to,
2381 * since we need to return and let src be expanded first.
2382 * Set ctx->pending_redirect, so we know what to do at the
2383 * end of the next parsed word.
2385 ctx->pending_redirect = redir;
2390 static struct pipe *new_pipe(void)
2393 pi = xzalloc(sizeof(struct pipe));
2394 /*pi->num_progs = 0;*/
2395 /*pi->progs = NULL;*/
2396 /*pi->next = NULL;*/
2397 /*pi->followup = 0; invalid */
2399 pi->r_mode = RES_NONE;
2403 static void initialize_context(struct p_context *ctx)
2406 ctx->pending_redirect = NULL;
2408 ctx->list_head = new_pipe();
2409 ctx->pipe = ctx->list_head;
2413 done_command(ctx); /* creates the memory for working child */
2416 /* normal return is 0
2417 * if a reserved word is found, and processed, return 1
2418 * should handle if, then, elif, else, fi, for, while, until, do, done.
2419 * case, function, and select are obnoxious, save those for later.
2421 static int reserved_word(o_string *dest, struct p_context *ctx)
2423 struct reserved_combo {
2428 /* Mostly a list of accepted follow-up reserved words.
2429 * FLAG_END means we are done with the sequence, and are ready
2430 * to turn the compound list into a command.
2431 * FLAG_START means the word must start a new compound list.
2433 static const struct reserved_combo reserved_list[] = {
2434 { "if", RES_IF, FLAG_THEN | FLAG_START },
2435 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2436 { "elif", RES_ELIF, FLAG_THEN },
2437 { "else", RES_ELSE, FLAG_FI },
2438 { "fi", RES_FI, FLAG_END },
2439 { "for", RES_FOR, FLAG_IN | FLAG_START },
2440 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2441 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2442 { "in", RES_IN, FLAG_DO },
2443 { "do", RES_DO, FLAG_DONE },
2444 { "done", RES_DONE, FLAG_END }
2446 enum { NRES = sizeof(reserved_list)/sizeof(reserved_list[0]) };
2447 const struct reserved_combo *r;
2449 for (r = reserved_list; r < reserved_list+NRES; r++) {
2450 if (strcmp(dest->data, r->literal) == 0) {
2451 debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
2452 if (r->flag & FLAG_START) {
2453 struct p_context *new = xmalloc(sizeof(struct p_context));
2454 debug_printf("push stack\n");
2455 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2462 *new = *ctx; /* physical copy */
2463 initialize_context(ctx);
2465 } else if (ctx->w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
2472 ctx->old_flag = r->flag;
2473 if (ctx->old_flag & FLAG_END) {
2474 struct p_context *old;
2475 debug_printf("pop stack\n");
2476 done_pipe(ctx, PIPE_SEQ);
2478 old->child->group = ctx->list_head;
2479 old->child->subshell = 0;
2480 *ctx = *old; /* physical copy */
2490 /* normal return is 0.
2491 * Syntax or xglob errors return 1. */
2492 static int done_word(o_string *dest, struct p_context *ctx)
2494 struct child_prog *child = ctx->child;
2495 glob_t *glob_target;
2498 debug_printf("done_word: %s %p\n", dest->data, child);
2499 if (dest->length == 0 && !dest->nonnull) {
2500 debug_printf(" true null, ignored\n");
2503 if (ctx->pending_redirect) {
2504 glob_target = &ctx->pending_redirect->word;
2508 return 1; /* syntax error, groups and arglists don't mix */
2510 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2511 debug_printf("checking %s for reserved-ness\n", dest->data);
2512 if (reserved_word(dest, ctx))
2513 return (ctx->w == RES_SNTX);
2515 glob_target = &child->glob_result;
2516 if (child->argv) flags |= GLOB_APPEND;
2518 gr = xglob(dest, flags, glob_target);
2519 if (gr != 0) return 1;
2522 if (ctx->pending_redirect) {
2523 ctx->pending_redirect = NULL;
2524 if (glob_target->gl_pathc != 1) {
2525 bb_error_msg("ambiguous redirect");
2529 child->argv = glob_target->gl_pathv;
2531 if (ctx->w == RES_FOR) {
2532 done_word(dest, ctx);
2533 done_pipe(ctx, PIPE_SEQ);
2538 /* The only possible error here is out of memory, in which case
2540 static int done_command(struct p_context *ctx)
2542 /* The child is really already in the pipe structure, so
2543 * advance the pipe counter and make a new, null child.
2544 * Only real trickiness here is that the uncommitted
2545 * child structure, to which ctx->child points, is not
2546 * counted in pi->num_progs. */
2547 struct pipe *pi = ctx->pipe;
2548 struct child_prog *prog = ctx->child;
2550 if (prog && prog->group == NULL
2551 && prog->argv == NULL
2552 && prog->redirects == NULL
2554 debug_printf("done_command: skipping null command\n");
2559 debug_printf("done_command: num_progs incremented to %d\n", pi->num_progs);
2561 debug_printf("done_command: initializing\n");
2563 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2565 prog = pi->progs + pi->num_progs;
2566 memset(prog, 0, sizeof(*prog));
2567 /*prog->redirects = NULL;*/
2568 /*prog->argv = NULL; */
2569 /*prog->is_stopped = 0;*/
2570 /*prog->group = NULL;*/
2571 /*prog->glob_result.gl_pathv = NULL;*/
2575 prog->type = ctx->type;
2577 /* but ctx->pipe and ctx->list_head remain unchanged */
2581 static int done_pipe(struct p_context *ctx, pipe_style type)
2584 done_command(ctx); /* implicit closure of previous command */
2585 debug_printf("done_pipe, type %d\n", type);
2586 ctx->pipe->followup = type;
2587 ctx->pipe->r_mode = ctx->w;
2589 ctx->pipe->next = new_p;
2592 done_command(ctx); /* set up new pipe to accept commands */
2596 /* peek ahead in the in_str to find out if we have a "&n" construct,
2597 * as in "2>&1", that represents duplicating a file descriptor.
2598 * returns either -2 (syntax error), -1 (no &), or the number found.
2600 static int redirect_dup_num(struct in_str *input)
2602 int ch, d = 0, ok = 0;
2604 if (ch != '&') return -1;
2606 b_getch(input); /* get the & */
2610 return -3; /* "-" represents "close me" */
2612 while (isdigit(ch)) {
2613 d = d*10 + (ch-'0');
2620 bb_error_msg("ambiguous redirect");
2624 /* If a redirect is immediately preceded by a number, that number is
2625 * supposed to tell which file descriptor to redirect. This routine
2626 * looks for such preceding numbers. In an ideal world this routine
2627 * needs to handle all the following classes of redirects...
2628 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2629 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2630 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2631 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2632 * A -1 output from this program means no valid number was found, so the
2633 * caller should use the appropriate default for this redirection.
2635 static int redirect_opt_num(o_string *o)
2641 for (num = 0; num < o->length; num++) {
2642 if (!isdigit(*(o->data + num))) {
2646 /* reuse num (and save an int) */
2647 num = atoi(o->data);
2652 static FILE *generate_stream_from_list(struct pipe *head)
2655 int pid, channel[2];
2656 if (pipe(channel) < 0) bb_perror_msg_and_die("pipe");
2663 bb_perror_msg_and_die("fork");
2664 } else if (pid == 0) {
2666 if (channel[1] != 1) {
2667 dup2(channel[1], 1);
2670 _exit(run_list_real(head)); /* leaks memory */
2672 debug_printf("forked child %d\n", pid);
2674 pf = fdopen(channel[0], "r");
2675 debug_printf("pipe on FILE *%p\n", pf);
2679 /* this version hacked for testing purposes */
2680 /* return code is exit status of the process that is run. */
2681 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2684 o_string result = NULL_O_STRING;
2685 struct p_context inner;
2687 struct in_str pipe_str;
2688 initialize_context(&inner);
2690 /* recursion to generate command */
2691 retcode = parse_stream(&result, &inner, input, subst_end);
2692 if (retcode != 0) return retcode; /* syntax error or EOF */
2693 done_word(&result, &inner);
2694 done_pipe(&inner, PIPE_SEQ);
2697 p = generate_stream_from_list(inner.list_head);
2698 if (p == NULL) return 1;
2699 mark_open(fileno(p));
2700 setup_file_in_str(&pipe_str, p);
2702 /* now send results of command back into original context */
2703 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2704 /* XXX In case of a syntax error, should we try to kill the child?
2705 * That would be tough to do right, so just read until EOF. */
2707 while (b_getch(&pipe_str) != EOF)
2711 debug_printf("done reading from pipe, pclose()ing\n");
2712 /* This is the step that wait()s for the child. Should be pretty
2713 * safe, since we just read an EOF from its stdout. We could try
2714 * to better, by using wait(), and keeping track of background jobs
2715 * at the same time. That would be a lot of work, and contrary
2716 * to the KISS philosophy of this program. */
2717 mark_closed(fileno(p));
2718 retcode = pclose(p);
2719 free_pipe_list(inner.list_head, 0);
2720 debug_printf("pclosed, retcode=%d\n", retcode);
2721 /* XXX this process fails to trim a single trailing newline */
2725 static int parse_group(o_string *dest, struct p_context *ctx,
2726 struct in_str *input, int ch)
2728 int rcode, endch = 0;
2729 struct p_context sub;
2730 struct child_prog *child = ctx->child;
2733 return 1; /* syntax error, groups and arglists don't mix */
2735 initialize_context(&sub);
2739 child->subshell = 1;
2745 syntax(); /* really logic error */
2747 rcode = parse_stream(dest, &sub, input, endch);
2748 done_word(dest, &sub); /* finish off the final word in the subcontext */
2749 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2750 child->group = sub.list_head;
2752 /* child remains "open", available for possible redirects */
2755 /* basically useful version until someone wants to get fancier,
2756 * see the bash man page under "Parameter Expansion" */
2757 static const char *lookup_param(const char *src)
2759 const char *p = NULL;
2763 p = get_local_var(src);
2768 /* Make new string for parser */
2769 static char* make_string(char ** inp)
2776 for (n = 0; inp[n]; n++) {
2777 p = insert_var_value(inp[n]);
2778 str = xrealloc(str, (len + strlen(p)));
2785 len = strlen(str) + 3;
2786 if (p != inp[n]) free(p);
2794 /* return code: 0 for OK, 1 for syntax error */
2795 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2799 int ch = input->peek(input); /* first character after the $ */
2800 debug_printf("handle_dollar: ch=%c\n", ch);
2802 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2804 while (ch = b_peek(input), isalnum(ch) || ch == '_') {
2808 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2809 } else if (isdigit(ch)) {
2810 i = ch - '0'; /* XXX is $0 special? */
2811 if (i < global_argc) {
2812 parse_string(dest, ctx, global_argv[i]); /* recursion */
2815 } else switch (ch) {
2817 b_adduint(dest, getpid());
2821 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2825 b_adduint(dest, last_return_code);
2829 b_adduint(dest, global_argc ? global_argc-1 : 0);
2833 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2836 /* XXX maybe someone will try to escape the '}' */
2838 ch = b_getch(input);
2839 if (ch == EOF || ch == '}')
2847 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2851 process_command_subs(dest, ctx, input, ')');
2855 for (i = 1; i < global_argc; i++) {
2856 parse_string(dest, ctx, global_argv[i]);
2857 if (i+1 < global_argc)
2858 parse_string(dest, ctx, sep);
2864 /* still unhandled, but should be eventually */
2865 bb_error_msg("unhandled syntax: $%c", ch);
2869 b_addqchr(dest,'$', dest->quote);
2871 /* Eat the character if the flag was set. If the compiler
2872 * is smart enough, we could substitute "b_getch(input);"
2873 * for all the "advance = 1;" above, and also end up with
2874 * a nice size-optimized program. Hah! That'll be the day.
2876 if (advance) b_getch(input);
2880 static int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2883 setup_string_in_str(&foo, src);
2884 return parse_stream(dest, ctx, &foo, '\0');
2887 /* return code is 0 for normal exit, 1 for syntax error */
2888 static int parse_stream(o_string *dest, struct p_context *ctx,
2889 struct in_str *input, int end_trigger)
2893 redir_type redir_style;
2896 /* Only double-quote state is handled in the state variable dest->quote.
2897 * A single-quote triggers a bypass of the main loop until its mate is
2898 * found. When recursing, quote state is passed in via dest->quote. */
2900 debug_printf("parse_stream, end_trigger=%d\n", end_trigger);
2901 while ((ch = b_getch(input)) != EOF) {
2903 next = (ch == '\n') ? 0 : b_peek(input);
2904 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2905 ch, ch, m, dest->quote);
2906 if (m == 0 || ((m == 1 || m == 2) && dest->quote)) {
2907 b_addqchr(dest, ch, dest->quote);
2910 if (m == 2) { /* unquoted IFS */
2911 if (done_word(dest, ctx)) {
2914 /* If we aren't performing a substitution, treat a newline as a
2915 * command separator. */
2916 if (end_trigger != '\0' && ch == '\n')
2917 done_pipe(ctx, PIPE_SEQ);
2919 if (ch == end_trigger && !dest->quote && ctx->w == RES_NONE) {
2920 debug_printf("leaving parse_stream (triggered)\n");
2927 if (dest->length == 0 && !dest->quote) {
2930 if (ch == EOF || ch == '\n')
2935 b_addqchr(dest, ch, dest->quote);
2943 b_addqchr(dest, '\\', dest->quote);
2944 b_addqchr(dest, b_getch(input), dest->quote);
2947 if (handle_dollar(dest, ctx, input) != 0) return 1;
2952 ch = b_getch(input);
2953 if (ch == EOF || ch == '\'')
2964 dest->quote = !dest->quote;
2967 process_command_subs(dest, ctx, input, '`');
2970 redir_fd = redirect_opt_num(dest);
2971 done_word(dest, ctx);
2972 redir_style = REDIRECT_OVERWRITE;
2974 redir_style = REDIRECT_APPEND;
2976 } else if (next == '(') {
2977 syntax(); /* until we support >(list) Process Substitution */
2980 setup_redirect(ctx, redir_fd, redir_style, input);
2983 redir_fd = redirect_opt_num(dest);
2984 done_word(dest, ctx);
2985 redir_style = REDIRECT_INPUT;
2987 redir_style = REDIRECT_HEREIS;
2989 } else if (next == '>') {
2990 redir_style = REDIRECT_IO;
2992 } else if (next == '(') {
2993 syntax(); /* until we support <(list) Process Substitution */
2996 setup_redirect(ctx, redir_fd, redir_style, input);
2999 done_word(dest, ctx);
3000 done_pipe(ctx, PIPE_SEQ);
3003 done_word(dest, ctx);
3006 done_pipe(ctx, PIPE_AND);
3008 done_pipe(ctx, PIPE_BG);
3012 done_word(dest, ctx);
3015 done_pipe(ctx, PIPE_OR);
3017 /* we could pick up a file descriptor choice here
3018 * with redirect_opt_num(), but bash doesn't do it.
3019 * "echo foo 2| cat" yields "foo 2". */
3025 if (parse_group(dest, ctx, input, ch) != 0)
3030 syntax(); /* Proper use of this character caught by end_trigger */
3033 syntax(); /* this is really an internal logic error */
3037 /* complain if quote? No, maybe we just finished a command substitution
3038 * that was quoted. Example:
3039 * $ echo "`cat foo` plus more"
3040 * and we just got the EOF generated by the subshell that ran "cat foo"
3041 * The only real complaint is if we got an EOF when end_trigger != '\0',
3042 * that is, we were really supposed to get end_trigger, and never got
3043 * one before the EOF. Can't use the standard "syntax error" return code,
3044 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3045 debug_printf("leaving parse_stream (EOF)\n");
3046 if (end_trigger != '\0')
3051 static void mapset(const char *set, int code)
3054 map[(unsigned char)*set++] = code;
3057 static void update_ifs_map(void)
3059 /* char *ifs and char map[256] are both globals. */
3060 ifs = getenv("IFS");
3061 if (ifs == NULL) ifs = " \t\n";
3062 /* Precompute a list of 'flow through' behavior so it can be treated
3063 * quickly up front. Computation is necessary because of IFS.
3064 * Special case handling of IFS == " \t\n" is not implemented.
3065 * The map[] array only really needs two bits each, and on most machines
3066 * that would be faster because of the reduced L1 cache footprint.
3068 memset(map, 0, sizeof(map)); /* most characters flow through always */
3069 mapset("\\$'\"`", 3); /* never flow through */
3070 mapset("<>;&|(){}#", 1); /* flow through if quoted */
3071 mapset(ifs, 2); /* also flow through if quoted */
3074 /* most recursion does not come through here, the exception is
3075 * from builtin_source() */
3076 static int parse_stream_outer(struct in_str *inp, int flag)
3078 struct p_context ctx;
3079 o_string temp = NULL_O_STRING;
3083 initialize_context(&ctx);
3085 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING))
3087 inp->promptmode = 1;
3088 rcode = parse_stream(&temp, &ctx, inp, '\n');
3089 if (rcode != 1 && ctx.old_flag != 0) {
3092 if (rcode != 1 && ctx.old_flag == 0) {
3093 done_word(&temp, &ctx);
3094 done_pipe(&ctx, PIPE_SEQ);
3095 run_list(ctx.list_head);
3097 if (ctx.old_flag != 0) {
3104 free_pipe_list(ctx.list_head, 0);
3107 } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
3111 static int parse_string_outer(const char *s, int flag)
3113 struct in_str input;
3114 setup_string_in_str(&input, s);
3115 return parse_stream_outer(&input, flag);
3118 static int parse_file_outer(FILE *f)
3121 struct in_str input;
3122 setup_file_in_str(&input, f);
3123 rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3127 #if ENABLE_HUSH_INTERACTIVE
3128 /* Make sure we have a controlling tty. If we get started under a job
3129 * aware app (like bash for example), make sure we are now in charge so
3130 * we don't fight over who gets the foreground */
3131 static void setup_job_control(void)
3135 saved_task_pgrp = shell_pgrp = getpgrp();
3136 debug_printf("saved_task_pgrp=%d\n", saved_task_pgrp);
3137 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3139 /* If we were ran as 'hush &',
3140 * sleep until we are in the foreground. */
3141 while (tcgetpgrp(interactive_fd) != shell_pgrp) {
3142 /* Send TTIN to ourself (should stop us) */
3143 kill(- shell_pgrp, SIGTTIN);
3144 shell_pgrp = getpgrp();
3147 /* Ignore job-control and misc signals. */
3148 set_jobctrl_sighandler(SIG_IGN);
3149 set_misc_sighandler(SIG_IGN);
3150 //huh? signal(SIGCHLD, SIG_IGN);
3152 /* We _must_ restore tty pgrp fatal signals */
3153 set_fatal_sighandler(sigexit);
3155 /* Put ourselves in our own process group. */
3156 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
3157 /* Grab control of the terminal. */
3158 tcsetpgrp(interactive_fd, getpid());
3162 int hush_main(int argc, char **argv);
3163 int hush_main(int argc, char **argv)
3169 #if ENABLE_FEATURE_EDITING
3170 line_input_state = new_line_input_t(FOR_SHELL);
3173 /* XXX what should these be while sourcing /etc/profile? */
3177 /* (re?) initialize globals. Sometimes hush_main() ends up calling
3178 * hush_main(), therefore we cannot rely on the BSS to zero out this
3179 * stuff. Reset these to 0 every time. */
3181 /* map[] is taken care of with call to update_ifs_map() */
3183 close_me_head = NULL;
3184 #if ENABLE_HUSH_INTERACTIVE
3191 /* Initialize some more globals to non-zero values */
3193 if (ENABLE_FEATURE_EDITING)
3194 cmdedit_set_initial_prompt();
3198 /* initialize our shell local variables with the values
3199 * currently living in the environment */
3203 set_local_var(*e++, 2); /* without call putenv() */
3205 last_return_code = EXIT_SUCCESS;
3207 if (argv[0] && argv[0][0] == '-') {
3208 debug_printf("\nsourcing /etc/profile\n");
3209 input = fopen("/etc/profile", "r");
3210 if (input != NULL) {
3211 mark_open(fileno(input));
3212 parse_file_outer(input);
3213 mark_closed(fileno(input));
3219 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3222 global_argv = argv + optind;
3223 global_argc = argc - optind;
3224 opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3227 // Well, we cannot just declare interactiveness,
3228 // we have to have some stuff (ctty, etc)
3229 /*interactive_fd++;*/
3236 fprintf(stderr, "Usage: sh [FILE]...\n"
3237 " or: sh -c command [args]...\n\n");
3244 #if ENABLE_HUSH_INTERACTIVE
3245 /* A shell is interactive if the '-i' flag was given, or if all of
3246 * the following conditions are met:
3248 * no arguments remaining or the -s flag given
3249 * standard input is a terminal
3250 * standard output is a terminal
3251 * Refer to Posix.2, the description of the 'sh' utility. */
3252 if (argv[optind] == NULL && input == stdin
3253 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3255 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
3256 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
3257 if (saved_tty_pgrp >= 0) {
3258 /* try to dup to high fd#, >= 255 */
3259 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3260 if (interactive_fd < 0) {
3261 /* try to dup to any fd */
3262 interactive_fd = dup(STDIN_FILENO);
3263 if (interactive_fd < 0)
3267 // TODO: track & disallow any attempts of user
3268 // to (inadvertently) close/redirect it
3271 debug_printf("\ninteractive_fd=%d\n", interactive_fd);
3272 if (interactive_fd) {
3273 /* Looks like they want an interactive shell */
3274 setup_job_control();
3275 /* Make xfuncs do cleanup on exit */
3276 die_sleep = -1; /* flag */
3277 if (setjmp(die_jmp)) {
3278 /* xfunc has failed! die die die */
3279 hush_exit(xfunc_error_retval);
3281 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
3282 printf("\n\n%s hush - the humble shell v0.02\n", BB_BANNER);
3283 printf("Enter 'help' for a list of built-in commands.\n\n");
3288 if (argv[optind] == NULL) {
3289 opt = parse_file_outer(stdin);
3293 debug_printf("\nrunning script '%s'\n", argv[optind]);
3294 global_argv = argv + optind;
3295 global_argc = argc - optind;
3296 input = xfopen(argv[optind], "r");
3297 opt = parse_file_outer(input);
3299 #if ENABLE_FEATURE_CLEAN_UP
3301 if (cwd != bb_msg_unknown)
3304 struct variables *cur, *tmp;
3305 for (cur = top_vars; cur; cur = tmp) {
3307 if (!cur->flg_read_only) {
3308 free((char*)cur->name);
3309 free((char*)cur->value);
3317 hush_exit(opt ? opt : last_return_code);