1 /* vi: set sw=4 ts=4: */
3 * lash -- the BusyBox Lame-Ass SHell
5 * Copyright (C) 1999,2000,2001 by Lineo, inc.
6 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
8 * Based in part on ladsh.c by Michael K. Johnson and Erik W. Troan, which is
9 * under the following liberal license: "We have placed this source code in the
10 * public domain. Use it in any project, free or commercial."
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28 /* The parsing engine of this program is officially at a dead-end.
29 * Future work in that direction should move to the work posted
30 * at http://doolittle.faludi.com/~larry/parser.html .
31 * A start on the integration of that work with the rest of sh.c
32 * is at http://codepoet.org/sh.c .
35 //This works pretty well now, and is now on by default.
36 #define BB_FEATURE_SH_ENVIRONMENT
38 //Backtick support has some problems, use at your own risk!
39 //#define BB_FEATURE_SH_BACKTICKS
41 //If, then, else, etc. support.. This should now behave basically
42 //like any other Bourne shell -- sortof...
43 #define BB_FEATURE_SH_IF_EXPRESSIONS
45 /* This is currently sortof broken, only for the brave... */
46 #undef HANDLE_CONTINUATION_CHARS
48 /* This would be great -- if wordexp wouldn't strip all quoting
49 * out from the target strings... As is, a parser needs */
50 #undef BB_FEATURE_SH_WORDEXP
52 //For debugging/development on the shell only...
63 #include <sys/ioctl.h>
68 #undef BB_FEATURE_SH_WORDEXP
70 #if BB_FEATURE_SH_WORDEXP
72 #define expand_t wordexp_t
73 #undef BB_FEATURE_SH_BACKTICKS
76 #define expand_t glob_t
82 static const int MAX_LINE = 256; /* size of input buffer for cwd data */
83 static const int MAX_READ = 128; /* size of input buffer for `read' builtin */
84 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
87 enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
91 static const unsigned int DEFAULT_CONTEXT=0x1;
92 static const unsigned int IF_TRUE_CONTEXT=0x2;
93 static const unsigned int IF_FALSE_CONTEXT=0x4;
94 static const unsigned int THEN_EXP_CONTEXT=0x8;
95 static const unsigned int ELSE_EXP_CONTEXT=0x10;
99 struct job *head; /* head of list of running jobs */
100 struct job *fg; /* current foreground job */
103 struct redir_struct {
104 enum redir_type type; /* type of redirection */
105 int fd; /* file descriptor being redirected */
106 char *filename; /* file to redirect fd to */
110 pid_t pid; /* 0 if exited */
111 char **argv; /* program name and arguments */
112 int num_redirects; /* elements in redirection array */
113 struct redir_struct *redirects; /* I/O redirects */
114 int is_stopped; /* is the program currently running? */
115 struct job *family; /* pointer back to the child's parent job */
119 int jobid; /* job number */
120 int num_progs; /* total number of programs in job */
121 int running_progs; /* number of programs running */
122 char *text; /* name of job */
123 char *cmdbuf; /* buffer various argv's point into */
124 pid_t pgrp; /* process group ID for the job */
125 struct child_prog *progs; /* array of programs in job */
126 struct job *next; /* to track background commands */
127 int stopped_progs; /* number of programs alive, but stopped */
128 unsigned int job_context; /* bitmask defining current context */
129 struct jobset *job_list;
132 struct built_in_command {
133 char *cmd; /* name */
134 char *descr; /* description */
135 int (*function) (struct child_prog *); /* function ptr */
140 struct close_me *next;
143 /* function prototypes for builtins */
144 static int builtin_cd(struct child_prog *cmd);
145 static int builtin_env(struct child_prog *dummy);
146 static int builtin_exec(struct child_prog *cmd);
147 static int builtin_exit(struct child_prog *cmd);
148 static int builtin_fg_bg(struct child_prog *cmd);
149 static int builtin_help(struct child_prog *cmd);
150 static int builtin_jobs(struct child_prog *dummy);
151 static int builtin_pwd(struct child_prog *dummy);
152 static int builtin_export(struct child_prog *cmd);
153 static int builtin_source(struct child_prog *cmd);
154 static int builtin_unset(struct child_prog *cmd);
155 static int builtin_read(struct child_prog *cmd);
156 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
157 static int builtin_if(struct child_prog *cmd);
158 static int builtin_then(struct child_prog *cmd);
159 static int builtin_else(struct child_prog *cmd);
160 static int builtin_fi(struct child_prog *cmd);
161 /* function prototypes for shell stuff */
162 static int run_command_predicate(char *cmd);
166 /* function prototypes for shell stuff */
167 static void mark_open(int fd);
168 static void mark_closed(int fd);
169 static void close_all(void);
170 static void checkjobs(struct jobset *job_list);
171 static int get_command(FILE * source, char *command);
172 static int parse_command(char **command_ptr, struct job *job, int *inbg);
173 static int run_command(struct job *newjob, int inbg, int outpipe[2]);
174 static int pseudo_exec(struct child_prog *cmd) __attribute__ ((noreturn));
175 static int busy_loop(FILE * input);
178 /* Table of built-in functions (these are non-forking builtins, meaning they
179 * can change global variables in the parent shell process but they will not
180 * work with pipes and redirects; 'unset foo | whatever' will not work) */
181 static struct built_in_command bltins[] = {
182 {"bg", "Resume a job in the background", builtin_fg_bg},
183 {"cd", "Change working directory", builtin_cd},
184 {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
185 {"exit", "Exit from shell()", builtin_exit},
186 {"fg", "Bring job into the foreground", builtin_fg_bg},
187 {"jobs", "Lists the active jobs", builtin_jobs},
188 {"export", "Set environment variable", builtin_export},
189 {"unset", "Unset environment variable", builtin_unset},
190 {"read", "Input environment variable", builtin_read},
191 {".", "Source-in and run commands in a file", builtin_source},
192 /* to do: add ulimit */
193 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
194 {"if", NULL, builtin_if},
195 {"then", NULL, builtin_then},
196 {"else", NULL, builtin_else},
197 {"fi", NULL, builtin_fi},
202 /* Table of forking built-in functions (things that fork cannot change global
203 * variables in the parent process, such as the current working directory) */
204 static struct built_in_command bltins_forking[] = {
205 {"env", "Print all environment variables", builtin_env},
206 {"pwd", "Print current directory", builtin_pwd},
207 {"help", "List shell built-in commands", builtin_help},
212 /* Variables we export */
213 unsigned int shell_context; /* Used in cmdedit.c to reset the
214 context when someone hits ^C */
217 /* Globals that are static to this file */
219 static char *local_pending_command = NULL;
220 static struct jobset job_list = { NULL, NULL };
223 static struct close_me *close_me_head;
224 #ifdef BB_FEATURE_SH_ENVIRONMENT
225 static int last_bg_pid;
226 static int last_return_code;
227 static int show_x_trace;
229 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
230 static char syntax_err[]="syntax error near unexpected token";
238 static inline void debug_printf(const char *format, ...)
241 va_start(args, format);
242 vfprintf(stderr, format, args);
246 static inline void debug_printf(const char *format, ...) { }
250 Most builtins need access to the struct child_prog that has
251 their arguments, previously coded as cmd->progs[0]. That coding
252 can exhibit a bug, if the builtin is not the first command in
253 a pipeline: "echo foo | exec sort" will attempt to exec foo.
255 builtin previous use notes
256 ------ ----------------- ---------
259 exec cmd->progs[0] squashed bug: didn't look for applets or forking builtins
261 fg_bg cmd->progs[0], job_list->head, job_list->fg
265 export cmd->progs[0] passes cmd, job_list to builtin_env(), which ignores them
269 if cmd->job_context, cmd->text
270 then cmd->job_context, cmd->text
271 else cmd->job_context, cmd->text
274 The use of cmd->text by if/then/else/fi is hopelessly hacky.
275 Would it work to increment cmd->progs[0]->argv and recurse,
276 somewhat like builtin_exec does?
278 I added "struct job *family;" to struct child_prog,
279 and switched API to builtin_foo(struct child_prog *child);
280 So cmd->text becomes child->family->text
281 cmd->job_context becomes child->family->job_context
282 cmd->progs[0] becomes *child
283 job_list becomes child->family->job_list
286 /* built-in 'cd <path>' handler */
287 static int builtin_cd(struct child_prog *child)
291 if (child->argv[1] == NULL)
292 newdir = getenv("HOME");
294 newdir = child->argv[1];
296 printf("cd: %s: %m\n", newdir);
299 getcwd(cwd, sizeof(char)*MAX_LINE);
304 /* built-in 'env' handler */
305 static int builtin_env(struct child_prog *dummy)
309 for (e = environ; *e; e++) {
315 /* built-in 'exec' handler */
316 static int builtin_exec(struct child_prog *child)
318 if (child->argv[1] == NULL)
319 return EXIT_SUCCESS; /* Really? */
326 /* built-in 'exit' handler */
327 static int builtin_exit(struct child_prog *child)
329 if (child->argv[1] == NULL)
332 exit (atoi(child->argv[1]));
335 /* built-in 'fg' and 'bg' handler */
336 static int builtin_fg_bg(struct child_prog *child)
339 struct job *job=NULL;
341 if (!child->argv[1] || child->argv[2]) {
342 error_msg("%s: exactly one argument is expected",
347 if (sscanf(child->argv[1], "%%%d", &jobNum) != 1) {
348 error_msg("%s: bad argument '%s'",
349 child->argv[0], child->argv[1]);
353 for (job = child->family->job_list->head; job; job = job->next) {
354 if (job->jobid == jobNum) {
360 error_msg("%s: unknown job %d",
361 child->argv[0], jobNum);
365 if (*child->argv[0] == 'f') {
366 /* Make this job the foreground job */
367 /* suppress messages when run from /linuxrc mag@sysgo.de */
368 if (tcsetpgrp(0, job->pgrp) && errno != ENOTTY)
369 perror_msg("tcsetpgrp");
370 child->family->job_list->fg = job;
373 /* Restart the processes in the job */
374 for (i = 0; i < job->num_progs; i++)
375 job->progs[i].is_stopped = 0;
377 kill(-job->pgrp, SIGCONT);
379 job->stopped_progs = 0;
384 /* built-in 'help' handler */
385 static int builtin_help(struct child_prog *dummy)
387 struct built_in_command *x;
389 printf("\nBuilt-in commands:\n");
390 printf("-------------------\n");
391 for (x = bltins; x->cmd; x++) {
394 printf("%s\t%s\n", x->cmd, x->descr);
396 for (x = bltins_forking; x->cmd; x++) {
399 printf("%s\t%s\n", x->cmd, x->descr);
405 /* built-in 'jobs' handler */
406 static int builtin_jobs(struct child_prog *child)
411 for (job = child->family->job_list->head; job; job = job->next) {
412 if (job->running_progs == job->stopped_progs)
413 status_string = "Stopped";
415 status_string = "Running";
417 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
423 /* built-in 'pwd' handler */
424 static int builtin_pwd(struct child_prog *dummy)
426 getcwd(cwd, MAX_LINE);
427 printf( "%s\n", cwd);
431 /* built-in 'export VAR=value' handler */
432 static int builtin_export(struct child_prog *child)
435 char *v = child->argv[1];
438 return (builtin_env(child));
442 fprintf(stderr, "export: %m\n");
443 #ifndef BB_FEATURE_SH_SIMPLE_PROMPT
444 if (strncmp(v, "PS1=", 4)==0)
446 else if (strncmp(v, "PS2=", 4)==0)
452 /* built-in 'read VAR' handler */
453 static int builtin_read(struct child_prog *child)
455 int res = 0, len, newlen;
457 char string[MAX_READ];
459 if (child->argv[1]) {
460 /* argument (VAR) given: put "VAR=" into buffer */
461 strcpy(string, child->argv[1]);
462 len = strlen(string);
465 fgets(&string[len], sizeof(string) - len, stdin); /* read string */
466 newlen = strlen(string);
468 string[--newlen] = '\0'; /* chomp trailing newline */
470 ** string should now contain "VAR=<value>"
471 ** copy it (putenv() won't do that, so we must make sure
472 ** the string resides in a static buffer!)
475 if((s = strdup(string)))
478 fprintf(stderr, "read: %m\n");
481 fgets(string, sizeof(string), stdin);
486 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
487 /* Built-in handler for 'if' commands */
488 static int builtin_if(struct child_prog *child)
490 struct job *cmd = child->family;
492 char* charptr1=cmd->text+3; /* skip over the leading 'if ' */
494 /* Now run the 'if' command */
495 debug_printf( "job=%p entering builtin_if ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
496 status = run_command_predicate(charptr1);
497 debug_printf( "if test returned ");
499 debug_printf( "TRUE\n");
500 cmd->job_context |= IF_TRUE_CONTEXT;
502 debug_printf( "FALSE\n");
503 cmd->job_context |= IF_FALSE_CONTEXT;
505 debug_printf("job=%p builtin_if set job context to %x\n", cmd, cmd->job_context);
511 /* Built-in handler for 'then' (part of the 'if' command) */
512 static int builtin_then(struct child_prog *child)
514 struct job *cmd = child->family;
515 char* charptr1=cmd->text+5; /* skip over the leading 'then ' */
517 debug_printf( "job=%p entering builtin_then ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
518 if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
519 shell_context = 0; /* Reset the shell's context on an error */
520 error_msg("%s `then'", syntax_err);
524 cmd->job_context |= THEN_EXP_CONTEXT;
525 debug_printf("job=%p builtin_then set job context to %x\n", cmd, cmd->job_context);
527 /* If the if result was FALSE, skip the 'then' stuff */
528 if (cmd->job_context & IF_FALSE_CONTEXT) {
532 /* Seems the if result was TRUE, so run the 'then' command */
533 debug_printf( "'then' now running '%s'\n", charptr1);
535 return(run_command_predicate(charptr1));
538 /* Built-in handler for 'else' (part of the 'if' command) */
539 static int builtin_else(struct child_prog *child)
541 struct job *cmd = child->family;
542 char* charptr1=cmd->text+5; /* skip over the leading 'else ' */
544 debug_printf( "job=%p entering builtin_else ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
546 if (! (cmd->job_context & THEN_EXP_CONTEXT)) {
547 shell_context = 0; /* Reset the shell's context on an error */
548 error_msg("%s `else'", syntax_err);
551 /* If the if result was TRUE, skip the 'else' stuff */
552 if (cmd->job_context & IF_TRUE_CONTEXT) {
556 cmd->job_context |= ELSE_EXP_CONTEXT;
557 debug_printf("job=%p builtin_else set job context to %x\n", cmd, cmd->job_context);
559 /* Now run the 'else' command */
560 debug_printf( "'else' now running '%s'\n", charptr1);
561 return(run_command_predicate(charptr1));
564 /* Built-in handler for 'fi' (part of the 'if' command) */
565 static int builtin_fi(struct child_prog *child)
567 struct job *cmd = child->family;
568 debug_printf( "job=%p entering builtin_fi ('%s')-- context=%d\n", cmd, "", cmd->job_context);
569 if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
570 shell_context = 0; /* Reset the shell's context on an error */
571 error_msg("%s `fi'", syntax_err);
574 /* Clear out the if and then context bits */
575 cmd->job_context &= ~(IF_TRUE_CONTEXT|IF_FALSE_CONTEXT|THEN_EXP_CONTEXT|ELSE_EXP_CONTEXT);
576 debug_printf("job=%p builtin_fi set job context to %x\n", cmd, cmd->job_context);
582 /* Built-in '.' handler (read-in and execute commands from file) */
583 static int builtin_source(struct child_prog *child)
589 if (child->argv[1] == NULL)
592 input = fopen(child->argv[1], "r");
594 printf( "Couldn't open file '%s'\n", child->argv[1]);
600 /* Now run the file */
601 status = busy_loop(input);
607 /* built-in 'unset VAR' handler */
608 static int builtin_unset(struct child_prog *child)
610 if (child->argv[1] == NULL) {
611 printf( "unset: parameter required.\n");
614 unsetenv(child->argv[1]);
618 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
619 /* currently used by if/then/else.
621 * Reparsing the command line for this purpose is gross,
622 * incorrect, and fundamentally unfixable; in particular,
623 * think about what happens with command substitution.
624 * We really need to pull out the run, wait, return status
625 * functionality out of busy_loop so we can child->argv++
626 * and use that, without going back through parse_command.
628 static int run_command_predicate(char *cmd)
631 local_pending_command = xmalloc(n+1);
632 strncpy(local_pending_command, cmd, n);
633 local_pending_command[n]='\0';
634 return( busy_loop(NULL));
638 static void mark_open(int fd)
640 struct close_me *new = xmalloc(sizeof(struct close_me));
642 new->next = close_me_head;
646 static void mark_closed(int fd)
648 struct close_me *tmp;
649 if (close_me_head == NULL || close_me_head->fd != fd)
650 error_msg_and_die("corrupt close_me");
652 close_me_head = close_me_head->next;
656 static void close_all()
658 struct close_me *c, *tmp;
659 for (c=close_me_head; c; c=tmp) {
664 close_me_head = NULL;
668 /* free up all memory from a job */
669 static void free_job(struct job *cmd)
673 for (i = 0; i < cmd->num_progs; i++) {
674 free(cmd->progs[i].argv);
675 if (cmd->progs[i].redirects)
676 free(cmd->progs[i].redirects);
682 memset(cmd, 0, sizeof(struct job));
685 /* remove a job from the job_list */
686 static void remove_job(struct jobset *job_list, struct job *job)
691 if (job == job_list->head) {
692 job_list->head = job->next;
694 prevjob = job_list->head;
695 while (prevjob->next != job)
696 prevjob = prevjob->next;
697 prevjob->next = job->next;
703 /* Checks to see if any background processes have exited -- if they
704 have, figure out why and see if a job has completed */
705 static void checkjobs(struct jobset *job_list)
712 while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
713 for (job = job_list->head; job; job = job->next) {
715 while (prognum < job->num_progs &&
716 job->progs[prognum].pid != childpid) prognum++;
717 if (prognum < job->num_progs)
721 /* This happens on backticked commands */
725 if (WIFEXITED(status) || WIFSIGNALED(status)) {
727 job->running_progs--;
728 job->progs[prognum].pid = 0;
730 if (!job->running_progs) {
731 printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text);
732 remove_job(job_list, job);
736 job->stopped_progs++;
737 job->progs[prognum].is_stopped = 1;
739 if (job->stopped_progs == job->num_progs) {
740 printf(JOB_STATUS_FORMAT, job->jobid, "Stopped",
746 if (childpid == -1 && errno != ECHILD)
747 perror_msg("waitpid");
750 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
751 * and stderr if they are redirected. */
752 static int setup_redirects(struct child_prog *prog, int squirrel[])
757 struct redir_struct *redir = prog->redirects;
759 for (i = 0; i < prog->num_redirects; i++, redir++) {
760 switch (redir->type) {
764 case REDIRECT_OVERWRITE:
765 mode = O_WRONLY | O_CREAT | O_TRUNC;
767 case REDIRECT_APPEND:
768 mode = O_WRONLY | O_CREAT | O_APPEND;
772 openfd = open(redir->filename, mode, 0666);
774 /* this could get lost if stderr has been redirected, but
775 bash and ash both lose it as well (though zsh doesn't!) */
776 perror_msg("error opening %s", redir->filename);
780 if (openfd != redir->fd) {
781 if (squirrel && redir->fd < 3) {
782 squirrel[redir->fd] = dup(redir->fd);
784 dup2(openfd, redir->fd);
792 static void restore_redirects(int squirrel[])
795 for (i=0; i<3; i++) {
798 /* No error checking. I sure wouldn't know what
799 * to do with an error if I found one! */
806 static inline void cmdedit_set_initial_prompt(void)
808 #ifdef BB_FEATURE_SH_SIMPLE_PROMPT
822 static inline void setup_prompt_string(char **prompt_str)
824 #ifdef BB_FEATURE_SH_SIMPLE_PROMPT
825 /* Set up the prompt */
826 if (shell_context == 0) {
829 PS1=xmalloc(strlen(cwd)+4);
830 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
836 *prompt_str = (shell_context==0)? PS1 : PS2;
840 static int get_command(FILE * source, char *command)
844 if (source == NULL) {
845 if (local_pending_command) {
846 /* a command specified (-c option): return it & mark it done */
847 strcpy(command, local_pending_command);
848 free(local_pending_command);
849 local_pending_command = NULL;
855 if (source == stdin) {
856 setup_prompt_string(&prompt_str);
858 #ifdef BB_FEATURE_COMMAND_EDITING
860 ** enable command line editing only while a command line
861 ** is actually being read; otherwise, we'll end up bequeathing
862 ** atexit() handlers and other unwanted stuff to our
863 ** child processes (rob@sysgo.de)
865 cmdedit_read_input(prompt_str, command);
869 fputs(prompt_str, stdout);
873 if (!fgets(command, BUFSIZ - 2, source)) {
879 /* remove trailing newline */
885 #ifdef BB_FEATURE_SH_ENVIRONMENT
886 static char* itoa(register int i)
888 static char a[7]; /* Max 7 ints */
889 register char *b = a + sizeof(a) - 1;
897 *--b = '0' + (i % 10);
907 #if defined BB_FEATURE_SH_ENVIRONMENT && ! defined BB_FEATURE_SH_WORDEXP
908 char * strsep_space( char *string, int * index)
914 /* Short circuit the trivial case */
915 if ( !string || ! string[*index])
918 /* Find the end of the token. */
919 while( string && string[*index] && !isspace(string[*index]) ) {
923 /* Find the end of any whitespace trailing behind
924 * the token and let that be part of the token */
925 while( string && string[*index] && isspace(string[*index]) ) {
929 if (! string && *index==0) {
930 /* Nothing useful was found */
934 token = xmalloc(*index);
935 token[*index] = '\0';
936 strncpy(token, string, *index);
943 static int expand_arguments(char *command)
945 #ifdef BB_FEATURE_SH_ENVIRONMENT
946 expand_t expand_result;
947 char *src, *dst, *var;
949 int i=0, length, total_length=0, retval;
950 const char *out_of_space = "out of space during expansion";
953 /* get rid of the terminating \n */
956 /* Fix up escape sequences to be the Real Thing(tm) */
957 while( command && command[index]) {
958 if (command[index] == '\\') {
959 char *tmp = command+index+1;
960 command[index+1] = process_escape_sequence( &tmp );
961 memmove(command+index, command+index+1, strlen(command+index));
966 #ifdef BB_FEATURE_SH_ENVIRONMENT
969 #if BB_FEATURE_SH_WORDEXP
970 /* This first part uses wordexp() which is a wonderful C lib
971 * function which expands nearly everything. */
972 retval = wordexp (command, &expand_result, WRDE_SHOWERR);
973 if (retval == WRDE_NOSPACE) {
974 /* Mem may have been allocated... */
975 wordfree (&expand_result);
976 error_msg(out_of_space);
980 /* Some other error. */
981 error_msg("syntax error");
985 if (expand_result.we_wordc > 0) {
986 /* Convert from char** (one word per string) to a simple char*,
987 * but don't overflow command which is BUFSIZ in length */
989 while (i < expand_result.we_wordc && total_length < BUFSIZ) {
990 length=strlen(expand_result.we_wordv[i])+1;
991 if (BUFSIZ-total_length-length <= 0) {
992 error_msg(out_of_space);
995 strcat(command+total_length, expand_result.we_wordv[i++]);
996 strcat(command+total_length, " ");
997 total_length+=length;
999 wordfree (&expand_result);
1003 /* Ok. They don't have a recent glibc and they don't have uClibc. Chances
1004 * are about 100% they don't have wordexp(). So instead the best we can do
1005 * is use glob and then fixup environment variables and such ourselves.
1006 * This is better then nothing, but certainly not perfect */
1008 /* It turns out that glob is very stupid. We have to feed it one word at a
1009 * time since it can't cope with a full string. Here we convert command
1010 * (char*) into cmd (char**, one word per string) */
1013 int flags = GLOB_NOCHECK
1021 char *tmpcmd, *cmd, *cmd_copy;
1022 /* We need a clean copy, so strsep can mess up the copy while
1023 * we write stuff into the original (in a minute) */
1024 cmd = cmd_copy = strdup(command);
1026 for (index = 0, tmpcmd = cmd;
1027 (tmpcmd = strsep_space(cmd, &index)) != NULL; cmd += index, index=0) {
1028 if (*tmpcmd == '\0')
1030 retval = glob(tmpcmd, flags, NULL, &expand_result);
1031 free(tmpcmd); /* Free mem allocated by strsep_space */
1032 if (retval == GLOB_NOSPACE) {
1033 /* Mem may have been allocated... */
1034 globfree (&expand_result);
1035 error_msg(out_of_space);
1037 } else if (retval != 0) {
1038 /* Some other error. GLOB_NOMATCH shouldn't
1039 * happen because of the GLOB_NOCHECK flag in
1041 error_msg("syntax error");
1044 /* Convert from char** (one word per string) to a simple char*,
1045 * but don't overflow command which is BUFSIZ in length */
1046 for (i=0; i < expand_result.gl_pathc; i++) {
1047 length=strlen(expand_result.gl_pathv[i])+1;
1048 if (BUFSIZ-total_length-length <= 0) {
1049 error_msg(out_of_space);
1052 strcat(command+total_length, expand_result.gl_pathv[i]);
1053 strcat(command+total_length, " ");
1054 total_length+=length;
1056 globfree (&expand_result);
1065 /* Now do the shell variable substitutions which
1066 * wordexp can't do for us, namely $? and $! */
1068 while((dst = strchr(src,'$')) != NULL){
1072 var = itoa(last_return_code);
1075 if (last_bg_pid==-1)
1078 var = itoa(last_bg_pid);
1080 /* Everything else like $$, $#, $[0-9], etc should all be
1081 * expanded by wordexp(), so we can in theory skip that stuff
1082 * here, but just to be on the safe side (i.e. since uClibc
1083 * wordexp doesn't do this stuff yet), lets leave it in for
1086 var = itoa(getpid());
1091 case '0':case '1':case '2':case '3':case '4':
1092 case '5':case '6':case '7':case '8':case '9':
1094 int index=*(dst + 1)-48;
1095 if (index >= argc) {
1105 /* a single character construction was found, and
1106 * already handled in the case statement */
1109 /* Looks like an environment variable */
1111 int num_skip_chars=1;
1112 int dstlen = strlen(dst);
1113 /* Is this a ${foo} type variable? */
1114 if (dstlen >=2 && *(dst+1) == '{') {
1115 src=strchr(dst+1, '}');
1118 src=strpbrk(dst+1, " \t~`!$^&*()=|\\[];\"'<>?./");
1124 *src='\0'; /* temporary */
1125 var = getenv(dst + num_skip_chars);
1127 if (num_skip_chars==2) {
1132 /* Seems we got an un-expandable variable. So delete it. */
1136 int subst_len = strlen(var);
1137 int trail_len = strlen(src);
1138 if (dst+subst_len+trail_len >= command+BUFSIZ) {
1139 error_msg(out_of_space);
1142 /* Move stuff to the end of the string to accommodate
1143 * filling the created gap with the new stuff */
1144 memmove(dst+subst_len, src, trail_len);
1145 *(dst+subst_len+trail_len)='\0';
1146 /* Now copy in the new stuff */
1147 memcpy(dst, var, subst_len);
1148 src = dst+subst_len;
1156 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
1157 line). If a valid command is found, command_ptr is set to point to
1158 the beginning of the next command (if the original command had more
1159 then one job associated with it) or NULL if no more commands are
1161 static int parse_command(char **command_ptr, struct job *job, int *inbg)
1164 char *return_command = NULL;
1165 char *src, *buf, *chptr;
1172 struct child_prog *prog;
1174 /* skip leading white space */
1175 while (**command_ptr && isspace(**command_ptr))
1178 /* this handles empty lines or leading '#' characters */
1179 if (!**command_ptr || (**command_ptr == '#')) {
1186 job->progs = xmalloc(sizeof(*job->progs));
1188 /* We set the argv elements to point inside of this string. The
1189 memory is freed by free_job(). Allocate twice the original
1190 length in case we need to quote every single character.
1192 Getting clean memory relieves us of the task of NULL
1193 terminating things and makes the rest of this look a bit
1194 cleaner (though it is, admittedly, a tad less efficient) */
1195 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
1199 prog->num_redirects = 0;
1200 prog->redirects = NULL;
1201 prog->is_stopped = 0;
1205 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1206 prog->argv[0] = job->cmdbuf;
1210 while (*src && !done) {
1211 if (quote == *src) {
1217 error_msg("character expected after \\");
1222 /* in shell, "\'" should yield \' */
1223 if (*src != quote) {
1227 } else if (*src == '*' || *src == '?' || *src == '[' ||
1228 *src == ']') *buf++ = '\\';
1230 } else if (isspace(*src)) {
1231 if (*prog->argv[argc_l]) {
1233 /* +1 here leaves room for the NULL which ends argv */
1234 if ((argc_l + 1) == argv_alloced) {
1236 prog->argv = xrealloc(prog->argv,
1237 sizeof(*prog->argv) *
1240 prog->argv[argc_l] = buf;
1249 case '#': /* comment */
1256 case '>': /* redirects */
1258 i = prog->num_redirects++;
1259 prog->redirects = xrealloc(prog->redirects,
1260 sizeof(*prog->redirects) *
1263 prog->redirects[i].fd = -1;
1264 if (buf != prog->argv[argc_l]) {
1265 /* the stuff before this character may be the file number
1267 prog->redirects[i].fd =
1268 strtol(prog->argv[argc_l], &chptr, 10);
1270 if (*chptr && *prog->argv[argc_l]) {
1272 prog->argv[argc_l] = buf;
1276 if (prog->redirects[i].fd == -1) {
1278 prog->redirects[i].fd = 1;
1280 prog->redirects[i].fd = 0;
1283 if (*src++ == '>') {
1285 prog->redirects[i].type =
1286 REDIRECT_APPEND, src++;
1288 prog->redirects[i].type = REDIRECT_OVERWRITE;
1290 prog->redirects[i].type = REDIRECT_INPUT;
1293 /* This isn't POSIX sh compliant. Oh well. */
1295 while (isspace(*chptr))
1299 error_msg("file name expected after %c", *src);
1305 prog->redirects[i].filename = buf;
1306 while (*chptr && !isspace(*chptr))
1309 src = chptr - 1; /* we src++ later */
1310 prog->argv[argc_l] = ++buf;
1313 case '|': /* pipe */
1314 /* finish this command */
1315 if (*prog->argv[argc_l])
1318 error_msg("empty command in pipe");
1323 prog->argv[argc_l] = NULL;
1325 /* and start the next */
1327 job->progs = xrealloc(job->progs,
1328 sizeof(*job->progs) * job->num_progs);
1329 prog = job->progs + (job->num_progs - 1);
1330 prog->num_redirects = 0;
1331 prog->redirects = NULL;
1332 prog->is_stopped = 0;
1337 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1338 prog->argv[0] = ++buf;
1341 while (*src && isspace(*src))
1345 error_msg("empty command in pipe");
1350 src--; /* we'll ++ it at the end of the loop */
1354 case '&': /* background */
1356 case ';': /* multiple commands */
1358 return_command = *command_ptr + (src - *command_ptr) + 1;
1361 #ifdef BB_FEATURE_SH_BACKTICKS
1363 /* Exec a backtick-ed command */
1364 /* Besides any previous brokenness, I have not
1365 * updated backtick handling for close_me support.
1366 * I don't know if it needs it or not. -- LRD */
1368 char* charptr1=NULL, *charptr2;
1371 struct jobset njob_list = { NULL, NULL };
1375 ptr=strchr(++src, '`');
1377 fprintf(stderr, "Unmatched '`' in command\n");
1382 /* Make some space to hold just the backticked command */
1383 charptr1 = charptr2 = xmalloc(1+ptr-src);
1384 memcpy(charptr1, src, ptr-src);
1385 charptr1[ptr-src] = '\0';
1386 newjob = xmalloc(sizeof(struct job));
1387 newjob->job_list = &njob_list;
1388 /* Now parse and run the backticked command */
1389 if (!parse_command(&charptr1, newjob, inbg)
1390 && newjob->num_progs) {
1392 run_command(newjob, 0, pipefd);
1394 checkjobs(job->job_list);
1395 free_job(newjob); /* doesn't actually free newjob,
1396 looks like a memory leak */
1399 /* Make a copy of any stuff left over in the command
1400 * line after the second backtick */
1401 charptr2 = xmalloc(strlen(ptr)+1);
1402 memcpy(charptr2, ptr+1, strlen(ptr));
1405 /* Copy the output from the backtick-ed command into the
1406 * command line, making extra room as needed */
1408 charptr1 = xmalloc(BUFSIZ);
1409 while ( (size=full_read(pipefd[0], charptr1, BUFSIZ-1)) >0) {
1410 int newsize=src - *command_ptr + size + 1 + strlen(charptr2);
1411 if (newsize > BUFSIZ) {
1412 *command_ptr=xrealloc(*command_ptr, newsize);
1414 memcpy(src, charptr1, size);
1422 /* Now paste into the *command_ptr all the stuff
1423 * leftover after the second backtick */
1424 memcpy(src, charptr2, strlen(charptr2)+1);
1427 /* Now recursively call parse_command to deal with the new
1428 * and improved version of the command line with the backtick
1429 * results expanded in place... */
1431 struct jobset *jl=job->job_list;
1435 return(parse_command(command_ptr, job, inbg));
1438 #endif // BB_FEATURE_SH_BACKTICKS
1443 /* This is currently a little broken... */
1444 #ifdef HANDLE_CONTINUATION_CHARS
1445 /* They fed us a continuation char, so continue reading stuff
1446 * on the next line, then tack that onto the end of the current
1450 printf("erik: found a continue char at EOL...\n");
1451 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1452 if (get_command(input, command)) {
1453 error_msg("character expected after \\");
1458 newsize = strlen(*command_ptr) + strlen(command) + 2;
1459 if (newsize > BUFSIZ) {
1460 printf("erik: doing realloc\n");
1461 *command_ptr=xrealloc(*command_ptr, newsize);
1463 printf("erik: A: *command_ptr='%s'\n", *command_ptr);
1464 memcpy(--src, command, strlen(command));
1465 printf("erik: B: *command_ptr='%s'\n", *command_ptr);
1469 error_msg("character expected after \\");
1475 if (*src == '*' || *src == '[' || *src == ']'
1476 || *src == '?') *buf++ = '\\';
1485 if (*prog->argv[argc_l]) {
1492 prog->argv[argc_l] = NULL;
1494 if (!return_command) {
1495 job->text = xmalloc(strlen(*command_ptr) + 1);
1496 strcpy(job->text, *command_ptr);
1498 /* This leaves any trailing spaces, which is a bit sloppy */
1499 count = return_command - *command_ptr;
1500 job->text = xmalloc(count + 1);
1501 strncpy(job->text, *command_ptr, count);
1502 job->text[count] = '\0';
1505 *command_ptr = return_command;
1510 /* Run the child_prog, no matter what kind of command it uses.
1512 static int pseudo_exec(struct child_prog *child)
1514 struct built_in_command *x;
1515 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1519 /* Check if the command matches any of the non-forking builtins.
1520 * Depending on context, this might be redundant. But it's
1521 * easier to waste a few CPU cycles than it is to figure out
1522 * if this is one of those cases.
1524 for (x = bltins; x->cmd; x++) {
1525 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1526 exit(x->function(child));
1530 /* Check if the command matches any of the forking builtins. */
1531 for (x = bltins_forking; x->cmd; x++) {
1532 if (strcmp(child->argv[0], x->cmd) == 0) {
1534 exit (x->function(child));
1537 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1538 /* Check if the command matches any busybox internal
1539 * commands ("applets") here. Following discussions from
1540 * November 2000 on busybox@opensource.lineo.com, don't use
1541 * get_last_path_component(). This way explicit (with
1542 * slashes) filenames will never be interpreted as an
1543 * applet, just like with builtins. This way the user can
1544 * override an applet with an explicit filename reference.
1545 * The only downside to this change is that an explicit
1546 * /bin/foo invocation will fork and exec /bin/foo, even if
1547 * /bin/foo is a symlink to busybox.
1549 name = child->argv[0];
1551 #ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1552 /* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then
1553 * if you run /bin/cat, it will use BusyBox cat even if
1554 * /bin/cat exists on the filesystem and is _not_ busybox.
1555 * Some systems want this, others do not. Choose wisely. :-)
1557 name = get_last_path_component(name);
1561 char** argv=child->argv;
1563 for(argc_l=0;*argv!=NULL; argv++, argc_l++);
1565 run_applet_by_name(name, argc_l, child->argv);
1569 execvp(child->argv[0], child->argv);
1570 perror_msg_and_die("%s", child->argv[0]);
1573 static void insert_job(struct job *newjob, int inbg)
1576 struct jobset *job_list=newjob->job_list;
1578 /* find the ID for thejob to use */
1580 for (thejob = job_list->head; thejob; thejob = thejob->next)
1581 if (thejob->jobid >= newjob->jobid)
1582 newjob->jobid = thejob->jobid + 1;
1584 /* add thejob to the list of running jobs */
1585 if (!job_list->head) {
1586 thejob = job_list->head = xmalloc(sizeof(*thejob));
1588 for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1589 thejob->next = xmalloc(sizeof(*thejob));
1590 thejob = thejob->next;
1593 *thejob = *newjob; /* physically copy the struct job */
1594 thejob->next = NULL;
1595 thejob->running_progs = thejob->num_progs;
1596 thejob->stopped_progs = 0;
1599 /* we don't wait for background thejobs to return -- append it
1600 to the list of backgrounded thejobs and leave it alone */
1601 printf("[%d] %d\n", thejob->jobid,
1602 newjob->progs[newjob->num_progs - 1].pid);
1603 #ifdef BB_FEATURE_SH_ENVIRONMENT
1604 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1607 newjob->job_list->fg = thejob;
1609 /* move the new process group into the foreground */
1610 /* suppress messages when run from /linuxrc mag@sysgo.de */
1611 if (tcsetpgrp(0, newjob->pgrp) && errno != ENOTTY)
1612 perror_msg("tcsetpgrp");
1616 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1618 /* struct job *thejob; */
1620 int nextin, nextout;
1621 int pipefds[2]; /* pipefd[0] is for reading */
1622 struct built_in_command *x;
1623 struct child_prog *child;
1625 nextin = 0, nextout = 1;
1626 for (i = 0; i < newjob->num_progs; i++) {
1627 child = & (newjob->progs[i]);
1629 if ((i + 1) < newjob->num_progs) {
1630 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1631 nextout = pipefds[1];
1633 if (outpipe[1]!=-1) {
1634 nextout = outpipe[1];
1640 #ifdef BB_FEATURE_SH_ENVIRONMENT
1641 if (show_x_trace==TRUE) {
1644 for (j = 0; child->argv[j]; j++) {
1646 fputs(child->argv[j], stderr);
1648 fputc('\n', stderr);
1652 /* Check if the command matches any non-forking builtins,
1653 * but only if this is a simple command.
1654 * Non-forking builtins within pipes have to fork anyway,
1655 * and are handled in pseudo_exec. "echo foo | read bar"
1656 * is doomed to failure, and doesn't work on bash, either.
1658 if (newjob->num_progs == 1) {
1659 for (x = bltins; x->cmd; x++) {
1660 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1661 int squirrel[] = {-1, -1, -1};
1663 setup_redirects(child, squirrel);
1664 rcode = x->function(child);
1665 restore_redirects(squirrel);
1671 if (!(child->pid = fork())) {
1672 signal(SIGTTOU, SIG_DFL);
1676 if (outpipe[1]!=-1) {
1686 dup2(nextout, 2); /* Really? */
1691 /* explicit redirects override pipes */
1692 setup_redirects(child,NULL);
1696 if (outpipe[1]!=-1) {
1700 /* put our child in the process group whose leader is the
1701 first process in this pipe */
1702 setpgid(child->pid, newjob->progs[0].pid);
1708 /* If there isn't another process, nextin is garbage
1709 but it doesn't matter */
1710 nextin = pipefds[0];
1713 newjob->pgrp = newjob->progs[0].pid;
1715 insert_job(newjob, inbg);
1720 static int busy_loop(FILE * input)
1723 char *next_command = NULL;
1729 newjob.job_list = &job_list;
1730 newjob.job_context = DEFAULT_CONTEXT;
1732 /* save current owner of TTY so we can restore it on exit */
1733 parent_pgrp = tcgetpgrp(0);
1735 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1737 /* don't pay any attention to this signal; it just confuses
1738 things and isn't really meant for shells anyway */
1739 signal(SIGTTOU, SIG_IGN);
1743 /* no job is in the foreground */
1745 /* see if any background processes have exited */
1746 checkjobs(&job_list);
1748 if (!next_command) {
1749 if (get_command(input, command))
1751 next_command = command;
1754 if (expand_arguments(next_command) == FALSE) {
1756 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1757 next_command = NULL;
1761 if (!parse_command(&next_command, &newjob, &inbg) &&
1763 int pipefds[2] = {-1,-1};
1764 debug_printf( "job=%p fed to run_command by busy_loop()'\n",
1766 run_command(&newjob, inbg, pipefds);
1770 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1771 next_command = NULL;
1774 /* a job is running in the foreground; wait for it */
1776 while (!job_list.fg->progs[i].pid ||
1777 job_list.fg->progs[i].is_stopped == 1) i++;
1779 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0)
1780 perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1782 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1783 /* the child exited */
1784 job_list.fg->running_progs--;
1785 job_list.fg->progs[i].pid = 0;
1787 #ifdef BB_FEATURE_SH_ENVIRONMENT
1788 last_return_code=WEXITSTATUS(status);
1789 debug_printf("'%s' exited -- return code %d\n",
1790 job_list.fg->text, last_return_code);
1792 if (!job_list.fg->running_progs) {
1794 remove_job(&job_list, job_list.fg);
1798 /* the child was stopped */
1799 job_list.fg->stopped_progs++;
1800 job_list.fg->progs[i].is_stopped = 1;
1802 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1803 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1804 "Stopped", job_list.fg->text);
1810 /* move the shell to the foreground */
1811 /* suppress messages when run from /linuxrc mag@sysgo.de */
1812 if (tcsetpgrp(0, getpid()) && errno != ENOTTY)
1813 perror_msg("tcsetpgrp");
1819 /* return controlling TTY back to parent process group before exiting */
1820 if (tcsetpgrp(0, parent_pgrp))
1821 perror_msg("tcsetpgrp");
1823 /* return exit status if called with "-c" */
1824 if (input == NULL && WIFEXITED(status))
1825 return WEXITSTATUS(status);
1831 #ifdef BB_FEATURE_CLEAN_UP
1832 void free_memory(void)
1836 if (local_pending_command)
1837 free(local_pending_command);
1839 if (job_list.fg && !job_list.fg->running_progs) {
1840 remove_job(&job_list, job_list.fg);
1846 int shell_main(int argc_l, char **argv_l)
1848 int opt, interactive=FALSE;
1849 FILE *input = stdin;
1853 /* These variables need re-initializing when recursing */
1856 local_pending_command = NULL;
1857 close_me_head = NULL;
1858 job_list.head = NULL;
1860 #ifdef BB_FEATURE_SH_ENVIRONMENT
1866 if (argv[0] && argv[0][0] == '-') {
1868 prof_input = fopen("/etc/profile", "r");
1870 printf( "Couldn't open file '/etc/profile'\n");
1872 int tmp_fd = fileno(prof_input);
1874 /* Now run the file */
1875 busy_loop(prof_input);
1877 mark_closed(tmp_fd);
1881 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1885 if (local_pending_command != 0)
1886 error_msg_and_die("multiple -c arguments");
1887 local_pending_command = xstrdup(argv[optind]);
1891 #ifdef BB_FEATURE_SH_ENVIRONMENT
1893 show_x_trace = TRUE;
1903 /* A shell is interactive if the `-i' flag was given, or if all of
1904 * the following conditions are met:
1906 * no arguments remaining or the -s flag given
1907 * standard input is a terminal
1908 * standard output is a terminal
1909 * Refer to Posix.2, the description of the `sh' utility. */
1910 if (argv[optind]==NULL && input==stdin &&
1911 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
1914 if (interactive==TRUE) {
1915 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1916 /* Looks like they want an interactive shell */
1917 printf( "\n\nBusyBox v%s (%s) Built-in shell (lash)\n", BB_VER, BB_BT);
1918 printf( "Enter 'help' for a list of built-in commands.\n\n");
1919 } else if (local_pending_command==NULL) {
1920 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1921 input = xfopen(argv[optind], "r");
1922 mark_open(fileno(input)); /* be lazy, never mark this closed */
1925 /* initialize the cwd -- this is never freed...*/
1926 cwd=(char*)xmalloc(sizeof(char)*MAX_LINE+1);
1927 getcwd(cwd, sizeof(char)*MAX_LINE);
1929 #ifdef BB_FEATURE_CLEAN_UP
1930 atexit(free_memory);
1933 #ifdef BB_FEATURE_COMMAND_EDITING
1934 cmdedit_set_initial_prompt();
1940 return (busy_loop(input));