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_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_SIMPLE_PROMPT
822 static inline void setup_prompt_string(char **prompt_str)
824 #ifdef BB_FEATURE_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|GLOB_BRACE|GLOB_TILDE;
1014 char *tmpcmd, *cmd, *cmd_copy;
1015 /* We need a clean copy, so strsep can mess up the copy while
1016 * we write stuff into the original (in a minute) */
1017 cmd = cmd_copy = strdup(command);
1019 for (index = 0, tmpcmd = cmd;
1020 (tmpcmd = strsep_space(cmd, &index)) != NULL; cmd += index, index=0) {
1021 if (*tmpcmd == '\0')
1023 retval = glob(tmpcmd, flags, NULL, &expand_result);
1024 free(tmpcmd); /* Free mem allocated by strsep_space */
1025 if (retval == GLOB_NOSPACE) {
1026 /* Mem may have been allocated... */
1027 globfree (&expand_result);
1028 error_msg(out_of_space);
1030 } else if (retval != 0) {
1031 /* Some other error. GLOB_NOMATCH shouldn't
1032 * happen because of the GLOB_NOCHECK flag in
1034 error_msg("syntax error");
1037 /* Convert from char** (one word per string) to a simple char*,
1038 * but don't overflow command which is BUFSIZ in length */
1039 for (i=0; i < expand_result.gl_pathc; i++) {
1040 length=strlen(expand_result.gl_pathv[i])+1;
1041 if (BUFSIZ-total_length-length <= 0) {
1042 error_msg(out_of_space);
1045 strcat(command+total_length, expand_result.gl_pathv[i]);
1046 strcat(command+total_length, " ");
1047 total_length+=length;
1049 globfree (&expand_result);
1058 /* Now do the shell variable substitutions which
1059 * wordexp can't do for us, namely $? and $! */
1061 while((dst = strchr(src,'$')) != NULL){
1065 var = itoa(last_return_code);
1068 if (last_bg_pid==-1)
1071 var = itoa(last_bg_pid);
1073 /* Everything else like $$, $#, $[0-9], etc should all be
1074 * expanded by wordexp(), so we can in theory skip that stuff
1075 * here, but just to be on the safe side (i.e. since uClibc
1076 * wordexp doesn't do this stuff yet), lets leave it in for
1079 var = itoa(getpid());
1084 case '0':case '1':case '2':case '3':case '4':
1085 case '5':case '6':case '7':case '8':case '9':
1087 int index=*(dst + 1)-48;
1088 if (index >= argc) {
1098 /* a single character construction was found, and
1099 * already handled in the case statement */
1102 /* Looks like an environment variable */
1104 int num_skip_chars=1;
1105 int dstlen = strlen(dst);
1106 /* Is this a ${foo} type variable? */
1107 if (dstlen >=2 && *(dst+1) == '{') {
1108 src=strchr(dst+1, '}');
1111 src=strpbrk(dst+1, " \t~`!$^&*()=|\\[];\"'<>?./");
1117 *src='\0'; /* temporary */
1118 var = getenv(dst + num_skip_chars);
1120 if (num_skip_chars==2) {
1125 /* Seems we got an un-expandable variable. So delete it. */
1129 int subst_len = strlen(var);
1130 int trail_len = strlen(src);
1131 if (dst+subst_len+trail_len >= command+BUFSIZ) {
1132 error_msg(out_of_space);
1135 /* Move stuff to the end of the string to accommodate
1136 * filling the created gap with the new stuff */
1137 memmove(dst+subst_len, src, trail_len);
1138 *(dst+subst_len+trail_len)='\0';
1139 /* Now copy in the new stuff */
1140 memcpy(dst, var, subst_len);
1141 src = dst+subst_len;
1149 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
1150 line). If a valid command is found, command_ptr is set to point to
1151 the beginning of the next command (if the original command had more
1152 then one job associated with it) or NULL if no more commands are
1154 static int parse_command(char **command_ptr, struct job *job, int *inbg)
1157 char *return_command = NULL;
1158 char *src, *buf, *chptr;
1165 struct child_prog *prog;
1167 /* skip leading white space */
1168 while (**command_ptr && isspace(**command_ptr))
1171 /* this handles empty lines or leading '#' characters */
1172 if (!**command_ptr || (**command_ptr == '#')) {
1179 job->progs = xmalloc(sizeof(*job->progs));
1181 /* We set the argv elements to point inside of this string. The
1182 memory is freed by free_job(). Allocate twice the original
1183 length in case we need to quote every single character.
1185 Getting clean memory relieves us of the task of NULL
1186 terminating things and makes the rest of this look a bit
1187 cleaner (though it is, admittedly, a tad less efficient) */
1188 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
1192 prog->num_redirects = 0;
1193 prog->redirects = NULL;
1194 prog->is_stopped = 0;
1198 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1199 prog->argv[0] = job->cmdbuf;
1203 while (*src && !done) {
1204 if (quote == *src) {
1210 error_msg("character expected after \\");
1215 /* in shell, "\'" should yield \' */
1216 if (*src != quote) {
1220 } else if (*src == '*' || *src == '?' || *src == '[' ||
1221 *src == ']') *buf++ = '\\';
1223 } else if (isspace(*src)) {
1224 if (*prog->argv[argc_l]) {
1226 /* +1 here leaves room for the NULL which ends argv */
1227 if ((argc_l + 1) == argv_alloced) {
1229 prog->argv = xrealloc(prog->argv,
1230 sizeof(*prog->argv) *
1233 prog->argv[argc_l] = buf;
1242 case '#': /* comment */
1249 case '>': /* redirects */
1251 i = prog->num_redirects++;
1252 prog->redirects = xrealloc(prog->redirects,
1253 sizeof(*prog->redirects) *
1256 prog->redirects[i].fd = -1;
1257 if (buf != prog->argv[argc_l]) {
1258 /* the stuff before this character may be the file number
1260 prog->redirects[i].fd =
1261 strtol(prog->argv[argc_l], &chptr, 10);
1263 if (*chptr && *prog->argv[argc_l]) {
1265 prog->argv[argc_l] = buf;
1269 if (prog->redirects[i].fd == -1) {
1271 prog->redirects[i].fd = 1;
1273 prog->redirects[i].fd = 0;
1276 if (*src++ == '>') {
1278 prog->redirects[i].type =
1279 REDIRECT_APPEND, src++;
1281 prog->redirects[i].type = REDIRECT_OVERWRITE;
1283 prog->redirects[i].type = REDIRECT_INPUT;
1286 /* This isn't POSIX sh compliant. Oh well. */
1288 while (isspace(*chptr))
1292 error_msg("file name expected after %c", *src);
1298 prog->redirects[i].filename = buf;
1299 while (*chptr && !isspace(*chptr))
1302 src = chptr - 1; /* we src++ later */
1303 prog->argv[argc_l] = ++buf;
1306 case '|': /* pipe */
1307 /* finish this command */
1308 if (*prog->argv[argc_l])
1311 error_msg("empty command in pipe");
1316 prog->argv[argc_l] = NULL;
1318 /* and start the next */
1320 job->progs = xrealloc(job->progs,
1321 sizeof(*job->progs) * job->num_progs);
1322 prog = job->progs + (job->num_progs - 1);
1323 prog->num_redirects = 0;
1324 prog->redirects = NULL;
1325 prog->is_stopped = 0;
1330 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1331 prog->argv[0] = ++buf;
1334 while (*src && isspace(*src))
1338 error_msg("empty command in pipe");
1343 src--; /* we'll ++ it at the end of the loop */
1347 case '&': /* background */
1349 case ';': /* multiple commands */
1351 return_command = *command_ptr + (src - *command_ptr) + 1;
1354 #ifdef BB_FEATURE_SH_BACKTICKS
1356 /* Exec a backtick-ed command */
1357 /* Besides any previous brokenness, I have not
1358 * updated backtick handling for close_me support.
1359 * I don't know if it needs it or not. -- LRD */
1361 char* charptr1=NULL, *charptr2;
1364 struct jobset njob_list = { NULL, NULL };
1368 ptr=strchr(++src, '`');
1370 fprintf(stderr, "Unmatched '`' in command\n");
1375 /* Make some space to hold just the backticked command */
1376 charptr1 = charptr2 = xmalloc(1+ptr-src);
1377 memcpy(charptr1, src, ptr-src);
1378 charptr1[ptr-src] = '\0';
1379 newjob = xmalloc(sizeof(struct job));
1380 newjob->job_list = &njob_list;
1381 /* Now parse and run the backticked command */
1382 if (!parse_command(&charptr1, newjob, inbg)
1383 && newjob->num_progs) {
1385 run_command(newjob, 0, pipefd);
1387 checkjobs(job->job_list);
1388 free_job(newjob); /* doesn't actually free newjob,
1389 looks like a memory leak */
1392 /* Make a copy of any stuff left over in the command
1393 * line after the second backtick */
1394 charptr2 = xmalloc(strlen(ptr)+1);
1395 memcpy(charptr2, ptr+1, strlen(ptr));
1398 /* Copy the output from the backtick-ed command into the
1399 * command line, making extra room as needed */
1401 charptr1 = xmalloc(BUFSIZ);
1402 while ( (size=full_read(pipefd[0], charptr1, BUFSIZ-1)) >0) {
1403 int newsize=src - *command_ptr + size + 1 + strlen(charptr2);
1404 if (newsize > BUFSIZ) {
1405 *command_ptr=xrealloc(*command_ptr, newsize);
1407 memcpy(src, charptr1, size);
1415 /* Now paste into the *command_ptr all the stuff
1416 * leftover after the second backtick */
1417 memcpy(src, charptr2, strlen(charptr2)+1);
1420 /* Now recursively call parse_command to deal with the new
1421 * and improved version of the command line with the backtick
1422 * results expanded in place... */
1424 struct jobset *jl=job->job_list;
1428 return(parse_command(command_ptr, job, inbg));
1431 #endif // BB_FEATURE_SH_BACKTICKS
1436 /* This is currently a little broken... */
1437 #ifdef HANDLE_CONTINUATION_CHARS
1438 /* They fed us a continuation char, so continue reading stuff
1439 * on the next line, then tack that onto the end of the current
1443 printf("erik: found a continue char at EOL...\n");
1444 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1445 if (get_command(input, command)) {
1446 error_msg("character expected after \\");
1451 newsize = strlen(*command_ptr) + strlen(command) + 2;
1452 if (newsize > BUFSIZ) {
1453 printf("erik: doing realloc\n");
1454 *command_ptr=xrealloc(*command_ptr, newsize);
1456 printf("erik: A: *command_ptr='%s'\n", *command_ptr);
1457 memcpy(--src, command, strlen(command));
1458 printf("erik: B: *command_ptr='%s'\n", *command_ptr);
1462 error_msg("character expected after \\");
1468 if (*src == '*' || *src == '[' || *src == ']'
1469 || *src == '?') *buf++ = '\\';
1478 if (*prog->argv[argc_l]) {
1485 prog->argv[argc_l] = NULL;
1487 if (!return_command) {
1488 job->text = xmalloc(strlen(*command_ptr) + 1);
1489 strcpy(job->text, *command_ptr);
1491 /* This leaves any trailing spaces, which is a bit sloppy */
1492 count = return_command - *command_ptr;
1493 job->text = xmalloc(count + 1);
1494 strncpy(job->text, *command_ptr, count);
1495 job->text[count] = '\0';
1498 *command_ptr = return_command;
1503 /* Run the child_prog, no matter what kind of command it uses.
1505 static int pseudo_exec(struct child_prog *child)
1507 struct built_in_command *x;
1508 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1512 /* Check if the command matches any of the non-forking builtins.
1513 * Depending on context, this might be redundant. But it's
1514 * easier to waste a few CPU cycles than it is to figure out
1515 * if this is one of those cases.
1517 for (x = bltins; x->cmd; x++) {
1518 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1519 exit(x->function(child));
1523 /* Check if the command matches any of the forking builtins. */
1524 for (x = bltins_forking; x->cmd; x++) {
1525 if (strcmp(child->argv[0], x->cmd) == 0) {
1527 exit (x->function(child));
1530 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1531 /* Check if the command matches any busybox internal
1532 * commands ("applets") here. Following discussions from
1533 * November 2000 on busybox@opensource.lineo.com, don't use
1534 * get_last_path_component(). This way explicit (with
1535 * slashes) filenames will never be interpreted as an
1536 * applet, just like with builtins. This way the user can
1537 * override an applet with an explicit filename reference.
1538 * The only downside to this change is that an explicit
1539 * /bin/foo invocation will fork and exec /bin/foo, even if
1540 * /bin/foo is a symlink to busybox.
1542 name = child->argv[0];
1544 #ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1545 /* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then
1546 * if you run /bin/cat, it will use BusyBox cat even if
1547 * /bin/cat exists on the filesystem and is _not_ busybox.
1548 * Some systems want this, others do not. Choose wisely. :-)
1550 name = get_last_path_component(name);
1554 char** argv=child->argv;
1556 for(argc_l=0;*argv!=NULL; argv++, argc_l++);
1558 run_applet_by_name(name, argc_l, child->argv);
1562 execvp(child->argv[0], child->argv);
1563 perror_msg_and_die("%s", child->argv[0]);
1566 static void insert_job(struct job *newjob, int inbg)
1569 struct jobset *job_list=newjob->job_list;
1571 /* find the ID for thejob to use */
1573 for (thejob = job_list->head; thejob; thejob = thejob->next)
1574 if (thejob->jobid >= newjob->jobid)
1575 newjob->jobid = thejob->jobid + 1;
1577 /* add thejob to the list of running jobs */
1578 if (!job_list->head) {
1579 thejob = job_list->head = xmalloc(sizeof(*thejob));
1581 for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1582 thejob->next = xmalloc(sizeof(*thejob));
1583 thejob = thejob->next;
1586 *thejob = *newjob; /* physically copy the struct job */
1587 thejob->next = NULL;
1588 thejob->running_progs = thejob->num_progs;
1589 thejob->stopped_progs = 0;
1592 /* we don't wait for background thejobs to return -- append it
1593 to the list of backgrounded thejobs and leave it alone */
1594 printf("[%d] %d\n", thejob->jobid,
1595 newjob->progs[newjob->num_progs - 1].pid);
1596 #ifdef BB_FEATURE_SH_ENVIRONMENT
1597 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1600 newjob->job_list->fg = thejob;
1602 /* move the new process group into the foreground */
1603 /* suppress messages when run from /linuxrc mag@sysgo.de */
1604 if (tcsetpgrp(0, newjob->pgrp) && errno != ENOTTY)
1605 perror_msg("tcsetpgrp");
1609 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1611 /* struct job *thejob; */
1613 int nextin, nextout;
1614 int pipefds[2]; /* pipefd[0] is for reading */
1615 struct built_in_command *x;
1616 struct child_prog *child;
1618 nextin = 0, nextout = 1;
1619 for (i = 0; i < newjob->num_progs; i++) {
1620 child = & (newjob->progs[i]);
1622 if ((i + 1) < newjob->num_progs) {
1623 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1624 nextout = pipefds[1];
1626 if (outpipe[1]!=-1) {
1627 nextout = outpipe[1];
1633 #ifdef BB_FEATURE_SH_ENVIRONMENT
1634 if (show_x_trace==TRUE) {
1637 for (j = 0; child->argv[j]; j++) {
1639 fputs(child->argv[j], stderr);
1641 fputc('\n', stderr);
1645 /* Check if the command matches any non-forking builtins,
1646 * but only if this is a simple command.
1647 * Non-forking builtins within pipes have to fork anyway,
1648 * and are handled in pseudo_exec. "echo foo | read bar"
1649 * is doomed to failure, and doesn't work on bash, either.
1651 if (newjob->num_progs == 1) {
1652 for (x = bltins; x->cmd; x++) {
1653 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1654 int squirrel[] = {-1, -1, -1};
1656 setup_redirects(child, squirrel);
1657 rcode = x->function(child);
1658 restore_redirects(squirrel);
1664 if (!(child->pid = fork())) {
1665 signal(SIGTTOU, SIG_DFL);
1669 if (outpipe[1]!=-1) {
1679 dup2(nextout, 2); /* Really? */
1684 /* explicit redirects override pipes */
1685 setup_redirects(child,NULL);
1689 if (outpipe[1]!=-1) {
1693 /* put our child in the process group whose leader is the
1694 first process in this pipe */
1695 setpgid(child->pid, newjob->progs[0].pid);
1701 /* If there isn't another process, nextin is garbage
1702 but it doesn't matter */
1703 nextin = pipefds[0];
1706 newjob->pgrp = newjob->progs[0].pid;
1708 insert_job(newjob, inbg);
1713 static int busy_loop(FILE * input)
1716 char *next_command = NULL;
1722 newjob.job_list = &job_list;
1723 newjob.job_context = DEFAULT_CONTEXT;
1725 /* save current owner of TTY so we can restore it on exit */
1726 parent_pgrp = tcgetpgrp(0);
1728 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1730 /* don't pay any attention to this signal; it just confuses
1731 things and isn't really meant for shells anyway */
1732 signal(SIGTTOU, SIG_IGN);
1736 /* no job is in the foreground */
1738 /* see if any background processes have exited */
1739 checkjobs(&job_list);
1741 if (!next_command) {
1742 if (get_command(input, command))
1744 next_command = command;
1747 if (expand_arguments(next_command) == FALSE) {
1749 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1750 next_command = NULL;
1754 if (!parse_command(&next_command, &newjob, &inbg) &&
1756 int pipefds[2] = {-1,-1};
1757 debug_printf( "job=%p fed to run_command by busy_loop()'\n",
1759 run_command(&newjob, inbg, pipefds);
1763 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1764 next_command = NULL;
1767 /* a job is running in the foreground; wait for it */
1769 while (!job_list.fg->progs[i].pid ||
1770 job_list.fg->progs[i].is_stopped == 1) i++;
1772 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0)
1773 perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1775 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1776 /* the child exited */
1777 job_list.fg->running_progs--;
1778 job_list.fg->progs[i].pid = 0;
1780 #ifdef BB_FEATURE_SH_ENVIRONMENT
1781 last_return_code=WEXITSTATUS(status);
1782 debug_printf("'%s' exited -- return code %d\n",
1783 job_list.fg->text, last_return_code);
1785 if (!job_list.fg->running_progs) {
1787 remove_job(&job_list, job_list.fg);
1791 /* the child was stopped */
1792 job_list.fg->stopped_progs++;
1793 job_list.fg->progs[i].is_stopped = 1;
1795 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1796 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1797 "Stopped", job_list.fg->text);
1803 /* move the shell to the foreground */
1804 /* suppress messages when run from /linuxrc mag@sysgo.de */
1805 if (tcsetpgrp(0, getpid()) && errno != ENOTTY)
1806 perror_msg("tcsetpgrp");
1812 /* return controlling TTY back to parent process group before exiting */
1813 if (tcsetpgrp(0, parent_pgrp))
1814 perror_msg("tcsetpgrp");
1816 /* return exit status if called with "-c" */
1817 if (input == NULL && WIFEXITED(status))
1818 return WEXITSTATUS(status);
1824 #ifdef BB_FEATURE_CLEAN_UP
1825 void free_memory(void)
1829 if (local_pending_command)
1830 free(local_pending_command);
1832 if (job_list.fg && !job_list.fg->running_progs) {
1833 remove_job(&job_list, job_list.fg);
1839 int shell_main(int argc_l, char **argv_l)
1841 int opt, interactive=FALSE;
1842 FILE *input = stdin;
1846 /* These variables need re-initializing when recursing */
1849 local_pending_command = NULL;
1850 close_me_head = NULL;
1851 job_list.head = NULL;
1853 #ifdef BB_FEATURE_SH_ENVIRONMENT
1859 if (argv[0] && argv[0][0] == '-') {
1861 prof_input = fopen("/etc/profile", "r");
1863 printf( "Couldn't open file '/etc/profile'\n");
1865 int tmp_fd = fileno(prof_input);
1867 /* Now run the file */
1868 busy_loop(prof_input);
1870 mark_closed(tmp_fd);
1874 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1878 if (local_pending_command != 0)
1879 error_msg_and_die("multiple -c arguments");
1880 local_pending_command = xstrdup(argv[optind]);
1884 #ifdef BB_FEATURE_SH_ENVIRONMENT
1886 show_x_trace = TRUE;
1896 /* A shell is interactive if the `-i' flag was given, or if all of
1897 * the following conditions are met:
1899 * no arguments remaining or the -s flag given
1900 * standard input is a terminal
1901 * standard output is a terminal
1902 * Refer to Posix.2, the description of the `sh' utility. */
1903 if (argv[optind]==NULL && input==stdin &&
1904 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
1907 if (interactive==TRUE) {
1908 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1909 /* Looks like they want an interactive shell */
1910 printf( "\n\nBusyBox v%s (%s) Built-in shell (lash)\n", BB_VER, BB_BT);
1911 printf( "Enter 'help' for a list of built-in commands.\n\n");
1912 } else if (local_pending_command==NULL) {
1913 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1914 input = xfopen(argv[optind], "r");
1915 mark_open(fileno(input)); /* be lazy, never mark this closed */
1918 /* initialize the cwd -- this is never freed...*/
1919 cwd=(char*)xmalloc(sizeof(char)*MAX_LINE+1);
1920 getcwd(cwd, sizeof(char)*MAX_LINE);
1922 #ifdef BB_FEATURE_CLEAN_UP
1923 atexit(free_memory);
1926 #ifdef BB_FEATURE_COMMAND_EDITING
1927 cmdedit_set_initial_prompt();
1933 return (busy_loop(input));