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)
674 for (i = 0; i < cmd->num_progs; i++) {
675 free(cmd->progs[i].argv);
676 if (cmd->progs[i].redirects)
677 free(cmd->progs[i].redirects);
685 keep = cmd->job_list;
686 memset(cmd, 0, sizeof(struct job));
687 cmd->job_list = keep;
690 /* remove a job from the job_list */
691 static void remove_job(struct jobset *job_list, struct job *job)
696 if (job == job_list->head) {
697 job_list->head = job->next;
699 prevjob = job_list->head;
700 while (prevjob->next != job)
701 prevjob = prevjob->next;
702 prevjob->next = job->next;
708 /* Checks to see if any background processes have exited -- if they
709 have, figure out why and see if a job has completed */
710 static void checkjobs(struct jobset *job_list)
717 while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
718 for (job = job_list->head; job; job = job->next) {
720 while (prognum < job->num_progs &&
721 job->progs[prognum].pid != childpid) prognum++;
722 if (prognum < job->num_progs)
726 /* This happens on backticked commands */
730 if (WIFEXITED(status) || WIFSIGNALED(status)) {
732 job->running_progs--;
733 job->progs[prognum].pid = 0;
735 if (!job->running_progs) {
736 printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text);
737 remove_job(job_list, job);
741 job->stopped_progs++;
742 job->progs[prognum].is_stopped = 1;
744 if (job->stopped_progs == job->num_progs) {
745 printf(JOB_STATUS_FORMAT, job->jobid, "Stopped",
751 if (childpid == -1 && errno != ECHILD)
752 perror_msg("waitpid");
755 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
756 * and stderr if they are redirected. */
757 static int setup_redirects(struct child_prog *prog, int squirrel[])
762 struct redir_struct *redir = prog->redirects;
764 for (i = 0; i < prog->num_redirects; i++, redir++) {
765 switch (redir->type) {
769 case REDIRECT_OVERWRITE:
770 mode = O_WRONLY | O_CREAT | O_TRUNC;
772 case REDIRECT_APPEND:
773 mode = O_WRONLY | O_CREAT | O_APPEND;
777 openfd = open(redir->filename, mode, 0666);
779 /* this could get lost if stderr has been redirected, but
780 bash and ash both lose it as well (though zsh doesn't!) */
781 perror_msg("error opening %s", redir->filename);
785 if (openfd != redir->fd) {
786 if (squirrel && redir->fd < 3) {
787 squirrel[redir->fd] = dup(redir->fd);
789 dup2(openfd, redir->fd);
797 static void restore_redirects(int squirrel[])
800 for (i=0; i<3; i++) {
803 /* No error checking. I sure wouldn't know what
804 * to do with an error if I found one! */
811 static inline void cmdedit_set_initial_prompt(void)
813 #ifdef BB_FEATURE_SH_SIMPLE_PROMPT
827 static inline void setup_prompt_string(char **prompt_str)
829 #ifdef BB_FEATURE_SH_SIMPLE_PROMPT
830 /* Set up the prompt */
831 if (shell_context == 0) {
834 PS1=xmalloc(strlen(cwd)+4);
835 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
841 *prompt_str = (shell_context==0)? PS1 : PS2;
845 static int get_command(FILE * source, char *command)
849 if (source == NULL) {
850 if (local_pending_command) {
851 /* a command specified (-c option): return it & mark it done */
852 strcpy(command, local_pending_command);
853 free(local_pending_command);
854 local_pending_command = NULL;
860 if (source == stdin) {
861 setup_prompt_string(&prompt_str);
863 #ifdef BB_FEATURE_COMMAND_EDITING
865 ** enable command line editing only while a command line
866 ** is actually being read; otherwise, we'll end up bequeathing
867 ** atexit() handlers and other unwanted stuff to our
868 ** child processes (rob@sysgo.de)
870 cmdedit_read_input(prompt_str, command);
874 fputs(prompt_str, stdout);
878 if (!fgets(command, BUFSIZ - 2, source)) {
884 /* remove trailing newline */
890 #ifdef BB_FEATURE_SH_ENVIRONMENT
891 static char* itoa(register int i)
893 static char a[7]; /* Max 7 ints */
894 register char *b = a + sizeof(a) - 1;
902 *--b = '0' + (i % 10);
912 #if defined BB_FEATURE_SH_ENVIRONMENT && ! defined BB_FEATURE_SH_WORDEXP
913 char * strsep_space( char *string, int * index)
919 /* Short circuit the trivial case */
920 if ( !string || ! string[*index])
923 /* Find the end of the token. */
924 while( string && string[*index] && !isspace(string[*index]) ) {
928 /* Find the end of any whitespace trailing behind
929 * the token and let that be part of the token */
930 while( string && string[*index] && isspace(string[*index]) ) {
934 if (! string && *index==0) {
935 /* Nothing useful was found */
939 token = xmalloc(*index+1);
940 token[*index] = '\0';
941 strncpy(token, string, *index);
948 static int expand_arguments(char *command)
950 #ifdef BB_FEATURE_SH_ENVIRONMENT
951 expand_t expand_result;
952 char *src, *dst, *var;
954 int i=0, length, total_length=0, retval;
955 const char *out_of_space = "out of space during expansion";
958 /* get rid of the terminating \n */
961 /* Fix up escape sequences to be the Real Thing(tm) */
962 while( command && command[index]) {
963 if (command[index] == '\\') {
964 char *tmp = command+index+1;
965 command[index+1] = process_escape_sequence( &tmp );
966 memmove(command+index, command+index+1, strlen(command+index));
971 #ifdef BB_FEATURE_SH_ENVIRONMENT
974 #if BB_FEATURE_SH_WORDEXP
975 /* This first part uses wordexp() which is a wonderful C lib
976 * function which expands nearly everything. */
977 retval = wordexp (command, &expand_result, WRDE_SHOWERR);
978 if (retval == WRDE_NOSPACE) {
979 /* Mem may have been allocated... */
980 wordfree (&expand_result);
981 error_msg(out_of_space);
985 /* Some other error. */
986 error_msg("syntax error");
990 if (expand_result.we_wordc > 0) {
991 /* Convert from char** (one word per string) to a simple char*,
992 * but don't overflow command which is BUFSIZ in length */
994 while (i < expand_result.we_wordc && total_length < BUFSIZ) {
995 length=strlen(expand_result.we_wordv[i])+1;
996 if (BUFSIZ-total_length-length <= 0) {
997 error_msg(out_of_space);
1000 strcat(command+total_length, expand_result.we_wordv[i++]);
1001 strcat(command+total_length, " ");
1002 total_length+=length;
1004 wordfree (&expand_result);
1008 /* Ok. They don't have a recent glibc and they don't have uClibc. Chances
1009 * are about 100% they don't have wordexp(). So instead the best we can do
1010 * is use glob and then fixup environment variables and such ourselves.
1011 * This is better then nothing, but certainly not perfect */
1013 /* It turns out that glob is very stupid. We have to feed it one word at a
1014 * time since it can't cope with a full string. Here we convert command
1015 * (char*) into cmd (char**, one word per string) */
1018 int flags = GLOB_NOCHECK
1026 char *tmpcmd, *cmd, *cmd_copy;
1027 /* We need a clean copy, so strsep can mess up the copy while
1028 * we write stuff into the original (in a minute) */
1029 cmd = cmd_copy = strdup(command);
1031 for (index = 0, tmpcmd = cmd;
1032 (tmpcmd = strsep_space(cmd, &index)) != NULL; cmd += index, index=0) {
1033 if (*tmpcmd == '\0')
1035 retval = glob(tmpcmd, flags, NULL, &expand_result);
1036 free(tmpcmd); /* Free mem allocated by strsep_space */
1037 if (retval == GLOB_NOSPACE) {
1038 /* Mem may have been allocated... */
1039 globfree (&expand_result);
1040 error_msg(out_of_space);
1042 } else if (retval != 0) {
1043 /* Some other error. GLOB_NOMATCH shouldn't
1044 * happen because of the GLOB_NOCHECK flag in
1046 error_msg("syntax error");
1049 /* Convert from char** (one word per string) to a simple char*,
1050 * but don't overflow command which is BUFSIZ in length */
1051 for (i=0; i < expand_result.gl_pathc; i++) {
1052 length=strlen(expand_result.gl_pathv[i]);
1053 if (BUFSIZ-total_length-length <= 0) {
1054 error_msg(out_of_space);
1057 strcat(command+total_length, expand_result.gl_pathv[i]);
1058 total_length+=length;
1060 globfree (&expand_result);
1069 /* Now do the shell variable substitutions which
1070 * wordexp can't do for us, namely $? and $! */
1072 while((dst = strchr(src,'$')) != NULL){
1076 var = itoa(last_return_code);
1079 if (last_bg_pid==-1)
1082 var = itoa(last_bg_pid);
1084 /* Everything else like $$, $#, $[0-9], etc should all be
1085 * expanded by wordexp(), so we can in theory skip that stuff
1086 * here, but just to be on the safe side (i.e. since uClibc
1087 * wordexp doesn't do this stuff yet), lets leave it in for
1090 var = itoa(getpid());
1095 case '0':case '1':case '2':case '3':case '4':
1096 case '5':case '6':case '7':case '8':case '9':
1098 int index=*(dst + 1)-48;
1099 if (index >= argc) {
1109 /* a single character construction was found, and
1110 * already handled in the case statement */
1113 /* Looks like an environment variable */
1115 int num_skip_chars=1;
1116 int dstlen = strlen(dst);
1117 /* Is this a ${foo} type variable? */
1118 if (dstlen >=2 && *(dst+1) == '{') {
1119 src=strchr(dst+1, '}');
1122 src=strpbrk(dst+1, " \t~`!$^&*()=|\\[];\"'<>?./");
1128 *src='\0'; /* temporary */
1129 var = getenv(dst + num_skip_chars);
1131 if (num_skip_chars==2) {
1136 /* Seems we got an un-expandable variable. So delete it. */
1140 int subst_len = strlen(var);
1141 int trail_len = strlen(src);
1142 if (dst+subst_len+trail_len >= command+BUFSIZ) {
1143 error_msg(out_of_space);
1146 /* Move stuff to the end of the string to accommodate
1147 * filling the created gap with the new stuff */
1148 memmove(dst+subst_len, src, trail_len);
1149 *(dst+subst_len+trail_len)='\0';
1150 /* Now copy in the new stuff */
1151 memcpy(dst, var, subst_len);
1152 src = dst+subst_len;
1160 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
1161 line). If a valid command is found, command_ptr is set to point to
1162 the beginning of the next command (if the original command had more
1163 then one job associated with it) or NULL if no more commands are
1165 static int parse_command(char **command_ptr, struct job *job, int *inbg)
1168 char *return_command = NULL;
1169 char *src, *buf, *chptr;
1176 struct child_prog *prog;
1178 /* skip leading white space */
1179 while (**command_ptr && isspace(**command_ptr))
1182 /* this handles empty lines or leading '#' characters */
1183 if (!**command_ptr || (**command_ptr == '#')) {
1190 job->progs = xmalloc(sizeof(*job->progs));
1192 /* We set the argv elements to point inside of this string. The
1193 memory is freed by free_job(). Allocate twice the original
1194 length in case we need to quote every single character.
1196 Getting clean memory relieves us of the task of NULL
1197 terminating things and makes the rest of this look a bit
1198 cleaner (though it is, admittedly, a tad less efficient) */
1199 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
1203 prog->num_redirects = 0;
1204 prog->redirects = NULL;
1205 prog->is_stopped = 0;
1209 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1210 prog->argv[0] = job->cmdbuf;
1214 while (*src && !done) {
1215 if (quote == *src) {
1221 error_msg("character expected after \\");
1226 /* in shell, "\'" should yield \' */
1227 if (*src != quote) {
1231 } else if (*src == '*' || *src == '?' || *src == '[' ||
1232 *src == ']') *buf++ = '\\';
1234 } else if (isspace(*src)) {
1235 if (*prog->argv[argc_l]) {
1237 /* +1 here leaves room for the NULL which ends argv */
1238 if ((argc_l + 1) == argv_alloced) {
1240 prog->argv = xrealloc(prog->argv,
1241 sizeof(*prog->argv) *
1244 prog->argv[argc_l] = buf;
1253 case '#': /* comment */
1260 case '>': /* redirects */
1262 i = prog->num_redirects++;
1263 prog->redirects = xrealloc(prog->redirects,
1264 sizeof(*prog->redirects) *
1267 prog->redirects[i].fd = -1;
1268 if (buf != prog->argv[argc_l]) {
1269 /* the stuff before this character may be the file number
1271 prog->redirects[i].fd =
1272 strtol(prog->argv[argc_l], &chptr, 10);
1274 if (*chptr && *prog->argv[argc_l]) {
1276 prog->argv[argc_l] = buf;
1280 if (prog->redirects[i].fd == -1) {
1282 prog->redirects[i].fd = 1;
1284 prog->redirects[i].fd = 0;
1287 if (*src++ == '>') {
1289 prog->redirects[i].type =
1290 REDIRECT_APPEND, src++;
1292 prog->redirects[i].type = REDIRECT_OVERWRITE;
1294 prog->redirects[i].type = REDIRECT_INPUT;
1297 /* This isn't POSIX sh compliant. Oh well. */
1299 while (isspace(*chptr))
1303 error_msg("file name expected after %c", *(src-1));
1309 prog->redirects[i].filename = buf;
1310 while (*chptr && !isspace(*chptr))
1313 src = chptr - 1; /* we src++ later */
1314 prog->argv[argc_l] = ++buf;
1317 case '|': /* pipe */
1318 /* finish this command */
1319 if (*prog->argv[argc_l])
1322 error_msg("empty command in pipe");
1327 prog->argv[argc_l] = NULL;
1329 /* and start the next */
1331 job->progs = xrealloc(job->progs,
1332 sizeof(*job->progs) * job->num_progs);
1333 prog = job->progs + (job->num_progs - 1);
1334 prog->num_redirects = 0;
1335 prog->redirects = NULL;
1336 prog->is_stopped = 0;
1341 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1342 prog->argv[0] = ++buf;
1345 while (*src && isspace(*src))
1349 error_msg("empty command in pipe");
1354 src--; /* we'll ++ it at the end of the loop */
1358 case '&': /* background */
1360 case ';': /* multiple commands */
1362 return_command = *command_ptr + (src - *command_ptr) + 1;
1365 #ifdef BB_FEATURE_SH_BACKTICKS
1367 /* Exec a backtick-ed command */
1368 /* Besides any previous brokenness, I have not
1369 * updated backtick handling for close_me support.
1370 * I don't know if it needs it or not. -- LRD */
1372 char* charptr1=NULL, *charptr2;
1375 struct jobset njob_list = { NULL, NULL };
1379 ptr=strchr(++src, '`');
1381 fprintf(stderr, "Unmatched '`' in command\n");
1386 /* Make some space to hold just the backticked command */
1387 charptr1 = charptr2 = xmalloc(1+ptr-src);
1388 memcpy(charptr1, src, ptr-src);
1389 charptr1[ptr-src] = '\0';
1390 newjob = xmalloc(sizeof(struct job));
1391 newjob->job_list = &njob_list;
1392 /* Now parse and run the backticked command */
1393 if (!parse_command(&charptr1, newjob, inbg)
1394 && newjob->num_progs) {
1396 run_command(newjob, 0, pipefd);
1398 checkjobs(job->job_list);
1399 free_job(newjob); /* doesn't actually free newjob,
1400 looks like a memory leak */
1403 /* Make a copy of any stuff left over in the command
1404 * line after the second backtick */
1405 charptr2 = xmalloc(strlen(ptr)+1);
1406 memcpy(charptr2, ptr+1, strlen(ptr));
1409 /* Copy the output from the backtick-ed command into the
1410 * command line, making extra room as needed */
1412 charptr1 = xmalloc(BUFSIZ);
1413 while ( (size=full_read(pipefd[0], charptr1, BUFSIZ-1)) >0) {
1414 int newsize=src - *command_ptr + size + 1 + strlen(charptr2);
1415 if (newsize > BUFSIZ) {
1416 *command_ptr=xrealloc(*command_ptr, newsize);
1418 memcpy(src, charptr1, size);
1426 /* Now paste into the *command_ptr all the stuff
1427 * leftover after the second backtick */
1428 memcpy(src, charptr2, strlen(charptr2)+1);
1431 /* Now recursively call parse_command to deal with the new
1432 * and improved version of the command line with the backtick
1433 * results expanded in place... */
1435 struct jobset *jl=job->job_list;
1439 return(parse_command(command_ptr, job, inbg));
1442 #endif // BB_FEATURE_SH_BACKTICKS
1447 /* This is currently a little broken... */
1448 #ifdef HANDLE_CONTINUATION_CHARS
1449 /* They fed us a continuation char, so continue reading stuff
1450 * on the next line, then tack that onto the end of the current
1454 printf("erik: found a continue char at EOL...\n");
1455 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1456 if (get_command(input, command)) {
1457 error_msg("character expected after \\");
1462 newsize = strlen(*command_ptr) + strlen(command) + 2;
1463 if (newsize > BUFSIZ) {
1464 printf("erik: doing realloc\n");
1465 *command_ptr=xrealloc(*command_ptr, newsize);
1467 printf("erik: A: *command_ptr='%s'\n", *command_ptr);
1468 memcpy(--src, command, strlen(command));
1469 printf("erik: B: *command_ptr='%s'\n", *command_ptr);
1473 error_msg("character expected after \\");
1479 if (*src == '*' || *src == '[' || *src == ']'
1480 || *src == '?') *buf++ = '\\';
1489 if (*prog->argv[argc_l]) {
1496 prog->argv[argc_l] = NULL;
1498 if (!return_command) {
1499 job->text = xmalloc(strlen(*command_ptr) + 1);
1500 strcpy(job->text, *command_ptr);
1502 /* This leaves any trailing spaces, which is a bit sloppy */
1503 count = return_command - *command_ptr;
1504 job->text = xmalloc(count + 1);
1505 strncpy(job->text, *command_ptr, count);
1506 job->text[count] = '\0';
1509 *command_ptr = return_command;
1514 /* Run the child_prog, no matter what kind of command it uses.
1516 static int pseudo_exec(struct child_prog *child)
1518 struct built_in_command *x;
1519 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1523 /* Check if the command matches any of the non-forking builtins.
1524 * Depending on context, this might be redundant. But it's
1525 * easier to waste a few CPU cycles than it is to figure out
1526 * if this is one of those cases.
1528 for (x = bltins; x->cmd; x++) {
1529 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1530 exit(x->function(child));
1534 /* Check if the command matches any of the forking builtins. */
1535 for (x = bltins_forking; x->cmd; x++) {
1536 if (strcmp(child->argv[0], x->cmd) == 0) {
1538 exit (x->function(child));
1541 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1542 /* Check if the command matches any busybox internal
1543 * commands ("applets") here. Following discussions from
1544 * November 2000 on busybox@opensource.lineo.com, don't use
1545 * get_last_path_component(). This way explicit (with
1546 * slashes) filenames will never be interpreted as an
1547 * applet, just like with builtins. This way the user can
1548 * override an applet with an explicit filename reference.
1549 * The only downside to this change is that an explicit
1550 * /bin/foo invocation will fork and exec /bin/foo, even if
1551 * /bin/foo is a symlink to busybox.
1553 name = child->argv[0];
1555 #ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1556 /* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then
1557 * if you run /bin/cat, it will use BusyBox cat even if
1558 * /bin/cat exists on the filesystem and is _not_ busybox.
1559 * Some systems want this, others do not. Choose wisely. :-)
1561 name = get_last_path_component(name);
1565 char** argv=child->argv;
1567 for(argc_l=0;*argv!=NULL; argv++, argc_l++);
1569 run_applet_by_name(name, argc_l, child->argv);
1573 execvp(child->argv[0], child->argv);
1574 perror_msg_and_die("%s", child->argv[0]);
1577 static void insert_job(struct job *newjob, int inbg)
1580 struct jobset *job_list=newjob->job_list;
1582 /* find the ID for thejob to use */
1584 for (thejob = job_list->head; thejob; thejob = thejob->next)
1585 if (thejob->jobid >= newjob->jobid)
1586 newjob->jobid = thejob->jobid + 1;
1588 /* add thejob to the list of running jobs */
1589 if (!job_list->head) {
1590 thejob = job_list->head = xmalloc(sizeof(*thejob));
1592 for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1593 thejob->next = xmalloc(sizeof(*thejob));
1594 thejob = thejob->next;
1597 *thejob = *newjob; /* physically copy the struct job */
1598 thejob->next = NULL;
1599 thejob->running_progs = thejob->num_progs;
1600 thejob->stopped_progs = 0;
1603 /* we don't wait for background thejobs to return -- append it
1604 to the list of backgrounded thejobs and leave it alone */
1605 printf("[%d] %d\n", thejob->jobid,
1606 newjob->progs[newjob->num_progs - 1].pid);
1607 #ifdef BB_FEATURE_SH_ENVIRONMENT
1608 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1611 newjob->job_list->fg = thejob;
1613 /* move the new process group into the foreground */
1614 /* suppress messages when run from /linuxrc mag@sysgo.de */
1615 if (tcsetpgrp(0, newjob->pgrp) && errno != ENOTTY)
1616 perror_msg("tcsetpgrp");
1620 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1622 /* struct job *thejob; */
1624 int nextin, nextout;
1625 int pipefds[2]; /* pipefd[0] is for reading */
1626 struct built_in_command *x;
1627 struct child_prog *child;
1629 nextin = 0, nextout = 1;
1630 for (i = 0; i < newjob->num_progs; i++) {
1631 child = & (newjob->progs[i]);
1633 if ((i + 1) < newjob->num_progs) {
1634 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1635 nextout = pipefds[1];
1637 if (outpipe[1]!=-1) {
1638 nextout = outpipe[1];
1644 #ifdef BB_FEATURE_SH_ENVIRONMENT
1645 if (show_x_trace==TRUE) {
1648 for (j = 0; child->argv[j]; j++) {
1650 fputs(child->argv[j], stderr);
1652 fputc('\n', stderr);
1656 /* Check if the command matches any non-forking builtins,
1657 * but only if this is a simple command.
1658 * Non-forking builtins within pipes have to fork anyway,
1659 * and are handled in pseudo_exec. "echo foo | read bar"
1660 * is doomed to failure, and doesn't work on bash, either.
1662 if (newjob->num_progs == 1) {
1663 for (x = bltins; x->cmd; x++) {
1664 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1665 int squirrel[] = {-1, -1, -1};
1667 setup_redirects(child, squirrel);
1668 rcode = x->function(child);
1669 restore_redirects(squirrel);
1675 if (!(child->pid = fork())) {
1676 signal(SIGTTOU, SIG_DFL);
1680 if (outpipe[1]!=-1) {
1690 dup2(nextout, 2); /* Really? */
1695 /* explicit redirects override pipes */
1696 setup_redirects(child,NULL);
1700 if (outpipe[1]!=-1) {
1704 /* put our child in the process group whose leader is the
1705 first process in this pipe */
1706 setpgid(child->pid, newjob->progs[0].pid);
1712 /* If there isn't another process, nextin is garbage
1713 but it doesn't matter */
1714 nextin = pipefds[0];
1717 newjob->pgrp = newjob->progs[0].pid;
1719 insert_job(newjob, inbg);
1724 static int busy_loop(FILE * input)
1727 char *next_command = NULL;
1733 newjob.job_list = &job_list;
1734 newjob.job_context = DEFAULT_CONTEXT;
1736 /* save current owner of TTY so we can restore it on exit */
1737 parent_pgrp = tcgetpgrp(0);
1739 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1741 /* don't pay any attention to this signal; it just confuses
1742 things and isn't really meant for shells anyway */
1743 signal(SIGTTOU, SIG_IGN);
1747 /* no job is in the foreground */
1749 /* see if any background processes have exited */
1750 checkjobs(&job_list);
1752 if (!next_command) {
1753 if (get_command(input, command))
1755 next_command = command;
1758 if (expand_arguments(next_command) == FALSE) {
1760 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1761 next_command = NULL;
1765 if (!parse_command(&next_command, &newjob, &inbg) &&
1767 int pipefds[2] = {-1,-1};
1768 debug_printf( "job=%p fed to run_command by busy_loop()'\n",
1770 run_command(&newjob, inbg, pipefds);
1774 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1775 next_command = NULL;
1778 /* a job is running in the foreground; wait for it */
1780 while (!job_list.fg->progs[i].pid ||
1781 job_list.fg->progs[i].is_stopped == 1) i++;
1783 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0)
1784 perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1786 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1787 /* the child exited */
1788 job_list.fg->running_progs--;
1789 job_list.fg->progs[i].pid = 0;
1791 #ifdef BB_FEATURE_SH_ENVIRONMENT
1792 last_return_code=WEXITSTATUS(status);
1793 debug_printf("'%s' exited -- return code %d\n",
1794 job_list.fg->text, last_return_code);
1796 if (!job_list.fg->running_progs) {
1798 remove_job(&job_list, job_list.fg);
1802 /* the child was stopped */
1803 job_list.fg->stopped_progs++;
1804 job_list.fg->progs[i].is_stopped = 1;
1806 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1807 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1808 "Stopped", job_list.fg->text);
1814 /* move the shell to the foreground */
1815 /* suppress messages when run from /linuxrc mag@sysgo.de */
1816 if (tcsetpgrp(0, getpid()) && errno != ENOTTY)
1817 perror_msg("tcsetpgrp");
1823 /* return controlling TTY back to parent process group before exiting */
1824 if (tcsetpgrp(0, parent_pgrp))
1825 perror_msg("tcsetpgrp");
1827 /* return exit status if called with "-c" */
1828 if (input == NULL && WIFEXITED(status))
1829 return WEXITSTATUS(status);
1835 #ifdef BB_FEATURE_CLEAN_UP
1836 void free_memory(void)
1840 if (local_pending_command)
1841 free(local_pending_command);
1843 if (job_list.fg && !job_list.fg->running_progs) {
1844 remove_job(&job_list, job_list.fg);
1850 int shell_main(int argc_l, char **argv_l)
1852 int opt, interactive=FALSE;
1853 FILE *input = stdin;
1857 /* These variables need re-initializing when recursing */
1860 local_pending_command = NULL;
1861 close_me_head = NULL;
1862 job_list.head = NULL;
1864 #ifdef BB_FEATURE_SH_ENVIRONMENT
1870 if (argv[0] && argv[0][0] == '-') {
1872 prof_input = fopen("/etc/profile", "r");
1874 printf( "Couldn't open file '/etc/profile'\n");
1876 int tmp_fd = fileno(prof_input);
1878 /* Now run the file */
1879 busy_loop(prof_input);
1881 mark_closed(tmp_fd);
1885 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1889 if (local_pending_command != 0)
1890 error_msg_and_die("multiple -c arguments");
1891 local_pending_command = xstrdup(argv[optind]);
1895 #ifdef BB_FEATURE_SH_ENVIRONMENT
1897 show_x_trace = TRUE;
1907 /* A shell is interactive if the `-i' flag was given, or if all of
1908 * the following conditions are met:
1910 * no arguments remaining or the -s flag given
1911 * standard input is a terminal
1912 * standard output is a terminal
1913 * Refer to Posix.2, the description of the `sh' utility. */
1914 if (argv[optind]==NULL && input==stdin &&
1915 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
1918 if (interactive==TRUE) {
1919 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1920 /* Looks like they want an interactive shell */
1921 printf( "\n\nBusyBox v%s (%s) Built-in shell (lash)\n", BB_VER, BB_BT);
1922 printf( "Enter 'help' for a list of built-in commands.\n\n");
1923 } else if (local_pending_command==NULL) {
1924 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1925 input = xfopen(argv[optind], "r");
1926 mark_open(fileno(input)); /* be lazy, never mark this closed */
1929 /* initialize the cwd -- this is never freed...*/
1930 cwd=(char*)xmalloc(sizeof(char)*MAX_LINE+1);
1931 getcwd(cwd, sizeof(char)*MAX_LINE);
1933 #ifdef BB_FEATURE_CLEAN_UP
1934 atexit(free_memory);
1937 #ifdef BB_FEATURE_COMMAND_EDITING
1938 cmdedit_set_initial_prompt();
1944 return (busy_loop(input));