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...
43 #define BB_FEATURE_SH_IF_EXPRESSIONS
45 /* This is currently a little broken... */
46 //#define HANDLE_CONTINUATION_CHARS
48 //For debugging/development on the shell only...
60 #include <sys/ioctl.h>
67 static const int MAX_LINE = 256; /* size of input buffer for cwd data */
68 static const int MAX_READ = 128; /* size of input buffer for `read' builtin */
69 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
72 enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
76 static const unsigned int DEFAULT_CONTEXT=0x1;
77 static const unsigned int IF_TRUE_CONTEXT=0x2;
78 static const unsigned int IF_FALSE_CONTEXT=0x4;
79 static const unsigned int THEN_EXP_CONTEXT=0x8;
80 static const unsigned int ELSE_EXP_CONTEXT=0x10;
84 struct job *head; /* head of list of running jobs */
85 struct job *fg; /* current foreground job */
89 enum redir_type type; /* type of redirection */
90 int fd; /* file descriptor being redirected */
91 char *filename; /* file to redirect fd to */
95 pid_t pid; /* 0 if exited */
96 char **argv; /* program name and arguments */
97 int num_redirects; /* elements in redirection array */
98 struct redir_struct *redirects; /* I/O redirects */
99 glob_t glob_result; /* result of parameter globbing */
100 int free_glob; /* should we globfree(&glob_result)? */
101 int is_stopped; /* is the program currently running? */
102 struct job *family; /* pointer back to the child's parent job */
106 int jobid; /* job number */
107 int num_progs; /* total number of programs in job */
108 int running_progs; /* number of programs running */
109 char *text; /* name of job */
110 char *cmdbuf; /* buffer various argv's point into */
111 pid_t pgrp; /* process group ID for the job */
112 struct child_prog *progs; /* array of programs in job */
113 struct job *next; /* to track background commands */
114 int stopped_progs; /* number of programs alive, but stopped */
115 unsigned int job_context; /* bitmask defining current context */
116 struct jobset *job_list;
119 struct built_in_command {
120 char *cmd; /* name */
121 char *descr; /* description */
122 int (*function) (struct child_prog *); /* function ptr */
127 struct close_me *next;
130 /* function prototypes for builtins */
131 static int builtin_cd(struct child_prog *cmd);
132 static int builtin_env(struct child_prog *dummy);
133 static int builtin_exec(struct child_prog *cmd);
134 static int builtin_exit(struct child_prog *cmd);
135 static int builtin_fg_bg(struct child_prog *cmd);
136 static int builtin_help(struct child_prog *cmd);
137 static int builtin_jobs(struct child_prog *dummy);
138 static int builtin_pwd(struct child_prog *dummy);
139 static int builtin_export(struct child_prog *cmd);
140 static int builtin_source(struct child_prog *cmd);
141 static int builtin_unset(struct child_prog *cmd);
142 static int builtin_read(struct child_prog *cmd);
143 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
144 static int builtin_if(struct child_prog *cmd);
145 static int builtin_then(struct child_prog *cmd);
146 static int builtin_else(struct child_prog *cmd);
147 static int builtin_fi(struct child_prog *cmd);
148 /* function prototypes for shell stuff */
149 static int run_command_predicate(char *cmd);
153 /* function prototypes for shell stuff */
154 static void mark_open(int fd);
155 static void mark_closed(int fd);
156 static void checkjobs(struct jobset *job_list);
157 static int get_command(FILE * source, char *command);
158 static int parse_command(char **command_ptr, struct job *job, int *inbg);
159 static int run_command(struct job *newjob, int inbg, int outpipe[2]);
160 static int pseudo_exec(struct child_prog *cmd) __attribute__ ((noreturn));
161 static int busy_loop(FILE * input);
164 /* Table of built-in functions (these are non-forking builtins, meaning they
165 * can change global variables in the parent shell process but they will not
166 * work with pipes and redirects; 'unset foo | whatever' will not work) */
167 static struct built_in_command bltins[] = {
168 {"bg", "Resume a job in the background", builtin_fg_bg},
169 {"cd", "Change working directory", builtin_cd},
170 {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
171 {"exit", "Exit from shell()", builtin_exit},
172 {"fg", "Bring job into the foreground", builtin_fg_bg},
173 {"jobs", "Lists the active jobs", builtin_jobs},
174 {"export", "Set environment variable", builtin_export},
175 {"unset", "Unset environment variable", builtin_unset},
176 {"read", "Input environment variable", builtin_read},
177 {".", "Source-in and run commands in a file", builtin_source},
178 /* to do: add ulimit */
179 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
180 {"if", NULL, builtin_if},
181 {"then", NULL, builtin_then},
182 {"else", NULL, builtin_else},
183 {"fi", NULL, builtin_fi},
188 /* Table of forking built-in functions (things that fork cannot change global
189 * variables in the parent process, such as the current working directory) */
190 static struct built_in_command bltins_forking[] = {
191 {"env", "Print all environment variables", builtin_env},
192 {"pwd", "Print current directory", builtin_pwd},
193 {"help", "List shell built-in commands", builtin_help},
198 /* Variables we export */
199 unsigned int shell_context; /* Used in cmdedit.c to reset the
200 context when someone hits ^C */
203 /* Globals that are static to this file */
205 static char *local_pending_command = NULL;
206 static struct jobset job_list = { NULL, NULL };
209 static struct close_me *close_me_head = NULL;
210 #ifdef BB_FEATURE_SH_ENVIRONMENT
211 static int last_bg_pid=-1;
212 static int last_return_code=-1;
213 static int show_x_trace=FALSE;
215 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
216 static char syntax_err[]="syntax error near unexpected token";
220 static inline void debug_printf(const char *format, ...)
223 va_start(args, format);
224 vfprintf(stderr, format, args);
228 static inline void debug_printf(const char *format, ...) { }
232 Most builtins need access to the struct child_prog that has
233 their arguments, previously coded as cmd->progs[0]. That coding
234 can exhibit a bug, if the builtin is not the first command in
235 a pipeline: "echo foo | exec sort" will attempt to exec foo.
237 builtin previous use notes
238 ------ ----------------- ---------
241 exec cmd->progs[0] squashed bug: didn't look for applets or forking builtins
243 fg_bg cmd->progs[0], job_list->head, job_list->fg
247 export cmd->progs[0] passes cmd, job_list to builtin_env(), which ignores them
251 if cmd->job_context, cmd->text
252 then cmd->job_context, cmd->text
253 else cmd->job_context, cmd->text
256 The use of cmd->text by if/then/else/fi is hopelessly hacky.
257 Would it work to increment cmd->progs[0]->argv and recurse,
258 somewhat like builtin_exec does?
260 I added "struct job *family;" to struct child_prog,
261 and switched API to builtin_foo(struct child_prog *child);
262 So cmd->text becomes child->family->text
263 cmd->job_context becomes child->family->job_context
264 cmd->progs[0] becomes *child
265 job_list becomes child->family->job_list
268 /* built-in 'cd <path>' handler */
269 static int builtin_cd(struct child_prog *child)
273 if (child->argv[1] == NULL)
274 newdir = getenv("HOME");
276 newdir = child->argv[1];
278 printf("cd: %s: %s\n", newdir, strerror(errno));
281 getcwd(cwd, sizeof(char)*MAX_LINE);
286 /* built-in 'env' handler */
287 static int builtin_env(struct child_prog *dummy)
291 for (e = environ; *e; e++) {
297 /* built-in 'exec' handler */
298 static int builtin_exec(struct child_prog *child)
300 if (child->argv[1] == NULL)
301 return EXIT_SUCCESS; /* Really? */
307 /* built-in 'exit' handler */
308 static int builtin_exit(struct child_prog *child)
310 if (child->argv[1] == NULL)
313 exit (atoi(child->argv[1]));
316 /* built-in 'fg' and 'bg' handler */
317 static int builtin_fg_bg(struct child_prog *child)
320 struct job *job=NULL;
322 if (!child->argv[1] || child->argv[2]) {
323 error_msg("%s: exactly one argument is expected",
328 if (sscanf(child->argv[1], "%%%d", &jobNum) != 1) {
329 error_msg("%s: bad argument '%s'",
330 child->argv[0], child->argv[1]);
334 for (job = child->family->job_list->head; job; job = job->next) {
335 if (job->jobid == jobNum) {
341 error_msg("%s: unknown job %d",
342 child->argv[0], jobNum);
346 if (*child->argv[0] == 'f') {
347 /* Make this job the foreground job */
348 /* suppress messages when run from /linuxrc mag@sysgo.de */
349 if (tcsetpgrp(0, job->pgrp) && errno != ENOTTY)
350 perror_msg("tcsetpgrp");
351 child->family->job_list->fg = job;
354 /* Restart the processes in the job */
355 for (i = 0; i < job->num_progs; i++)
356 job->progs[i].is_stopped = 0;
358 kill(-job->pgrp, SIGCONT);
360 job->stopped_progs = 0;
365 /* built-in 'help' handler */
366 static int builtin_help(struct child_prog *dummy)
368 struct built_in_command *x;
370 printf("\nBuilt-in commands:\n");
371 printf("-------------------\n");
372 for (x = bltins; x->cmd; x++) {
375 printf("%s\t%s\n", x->cmd, x->descr);
377 for (x = bltins_forking; x->cmd; x++) {
380 printf("%s\t%s\n", x->cmd, x->descr);
386 /* built-in 'jobs' handler */
387 static int builtin_jobs(struct child_prog *child)
392 for (job = child->family->job_list->head; job; job = job->next) {
393 if (job->running_progs == job->stopped_progs)
394 status_string = "Stopped";
396 status_string = "Running";
398 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
404 /* built-in 'pwd' handler */
405 static int builtin_pwd(struct child_prog *dummy)
407 getcwd(cwd, MAX_LINE);
408 printf( "%s\n", cwd);
412 /* built-in 'export VAR=value' handler */
413 static int builtin_export(struct child_prog *child)
417 if (child->argv[1] == NULL) {
418 return (builtin_env(child));
420 res = putenv(child->argv[1]);
422 fprintf(stderr, "export: %s\n", strerror(errno));
426 /* built-in 'read VAR' handler */
427 static int builtin_read(struct child_prog *child)
429 int res = 0, len, newlen;
431 char string[MAX_READ];
433 if (child->argv[1]) {
434 /* argument (VAR) given: put "VAR=" into buffer */
435 strcpy(string, child->argv[1]);
436 len = strlen(string);
439 fgets(&string[len], sizeof(string) - len, stdin); /* read string */
440 newlen = strlen(string);
442 string[--newlen] = '\0'; /* chomp trailing newline */
444 ** string should now contain "VAR=<value>"
445 ** copy it (putenv() won't do that, so we must make sure
446 ** the string resides in a static buffer!)
449 if((s = strdup(string)))
452 fprintf(stderr, "read: %s\n", strerror(errno));
455 fgets(string, sizeof(string), stdin);
460 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
461 /* Built-in handler for 'if' commands */
462 static int builtin_if(struct child_prog *child)
464 struct job *cmd = child->family;
466 char* charptr1=cmd->text+3; /* skip over the leading 'if ' */
468 /* Now run the 'if' command */
469 debug_printf( "job=%p entering builtin_if ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
470 status = run_command_predicate(charptr1);
471 debug_printf( "if test returned ");
473 debug_printf( "TRUE\n");
474 cmd->job_context |= IF_TRUE_CONTEXT;
476 debug_printf( "FALSE\n");
477 cmd->job_context |= IF_FALSE_CONTEXT;
479 debug_printf("job=%p builtin_if set job context to %x\n", cmd, cmd->job_context);
485 /* Built-in handler for 'then' (part of the 'if' command) */
486 static int builtin_then(struct child_prog *child)
488 struct job *cmd = child->family;
489 char* charptr1=cmd->text+5; /* skip over the leading 'then ' */
491 debug_printf( "job=%p entering builtin_then ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
492 if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
493 shell_context = 0; /* Reset the shell's context on an error */
494 error_msg("%s `then'", syntax_err);
498 cmd->job_context |= THEN_EXP_CONTEXT;
499 debug_printf("job=%p builtin_then set job context to %x\n", cmd, cmd->job_context);
501 /* If the if result was FALSE, skip the 'then' stuff */
502 if (cmd->job_context & IF_FALSE_CONTEXT) {
506 /* Seems the if result was TRUE, so run the 'then' command */
507 debug_printf( "'then' now running '%s'\n", charptr1);
509 return(run_command_predicate(charptr1));
512 /* Built-in handler for 'else' (part of the 'if' command) */
513 static int builtin_else(struct child_prog *child)
515 struct job *cmd = child->family;
516 char* charptr1=cmd->text+5; /* skip over the leading 'else ' */
518 debug_printf( "job=%p entering builtin_else ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
520 if (! (cmd->job_context & THEN_EXP_CONTEXT)) {
521 shell_context = 0; /* Reset the shell's context on an error */
522 error_msg("%s `else'", syntax_err);
525 /* If the if result was TRUE, skip the 'else' stuff */
526 if (cmd->job_context & IF_TRUE_CONTEXT) {
530 cmd->job_context |= ELSE_EXP_CONTEXT;
531 debug_printf("job=%p builtin_else set job context to %x\n", cmd, cmd->job_context);
533 /* Now run the 'else' command */
534 debug_printf( "'else' now running '%s'\n", charptr1);
535 return(run_command_predicate(charptr1));
538 /* Built-in handler for 'fi' (part of the 'if' command) */
539 static int builtin_fi(struct child_prog *child)
541 struct job *cmd = child->family;
542 debug_printf( "job=%p entering builtin_fi ('%s')-- context=%d\n", cmd, "", cmd->job_context);
543 if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
544 shell_context = 0; /* Reset the shell's context on an error */
545 error_msg("%s `fi'", syntax_err);
548 /* Clear out the if and then context bits */
549 cmd->job_context &= ~(IF_TRUE_CONTEXT|IF_FALSE_CONTEXT|THEN_EXP_CONTEXT|ELSE_EXP_CONTEXT);
550 debug_printf("job=%p builtin_fi set job context to %x\n", cmd, cmd->job_context);
556 /* Built-in '.' handler (read-in and execute commands from file) */
557 static int builtin_source(struct child_prog *child)
563 if (child->argv[1] == NULL)
566 input = fopen(child->argv[1], "r");
568 printf( "Couldn't open file '%s'\n", child->argv[1]);
574 /* Now run the file */
575 status = busy_loop(input);
581 /* built-in 'unset VAR' handler */
582 static int builtin_unset(struct child_prog *child)
584 if (child->argv[1] == NULL) {
585 printf( "unset: parameter required.\n");
588 unsetenv(child->argv[1]);
592 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
593 /* currently used by if/then/else.
595 * Reparsing the command line for this purpose is gross,
596 * incorrect, and fundamentally unfixable; in particular,
597 * think about what happens with command substitution.
598 * We really need to pull out the run, wait, return status
599 * functionality out of busy_loop so we can child->argv++
600 * and use that, without going back through parse_command.
602 static int run_command_predicate(char *cmd)
605 local_pending_command = xmalloc(n+1);
606 strncpy(local_pending_command, cmd, n);
607 local_pending_command[n]='\0';
608 return( busy_loop(NULL));
612 static void mark_open(int fd)
614 struct close_me *new = xmalloc(sizeof(struct close_me));
616 new->next = close_me_head;
620 static void mark_closed(int fd)
622 struct close_me *tmp;
623 if (close_me_head == NULL || close_me_head->fd != fd)
624 error_msg_and_die("corrupt close_me");
626 close_me_head = close_me_head->next;
630 static void close_all()
633 for (c=close_me_head; c; c=c->next) {
636 close_me_head = NULL;
640 /* free up all memory from a job */
641 static void free_job(struct job *cmd)
645 for (i = 0; i < cmd->num_progs; i++) {
646 free(cmd->progs[i].argv);
647 if (cmd->progs[i].redirects)
648 free(cmd->progs[i].redirects);
649 if (cmd->progs[i].free_glob)
650 globfree(&cmd->progs[i].glob_result);
656 memset(cmd, 0, sizeof(struct job));
659 /* remove a job from the job_list */
660 static void remove_job(struct jobset *job_list, struct job *job)
665 if (job == job_list->head) {
666 job_list->head = job->next;
668 prevjob = job_list->head;
669 while (prevjob->next != job)
670 prevjob = prevjob->next;
671 prevjob->next = job->next;
677 /* Checks to see if any background processes have exited -- if they
678 have, figure out why and see if a job has completed */
679 static void checkjobs(struct jobset *job_list)
686 while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
687 for (job = job_list->head; job; job = job->next) {
689 while (prognum < job->num_progs &&
690 job->progs[prognum].pid != childpid) prognum++;
691 if (prognum < job->num_progs)
695 /* This happens on backticked commands */
699 if (WIFEXITED(status) || WIFSIGNALED(status)) {
701 job->running_progs--;
702 job->progs[prognum].pid = 0;
704 if (!job->running_progs) {
705 printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text);
706 remove_job(job_list, job);
710 job->stopped_progs++;
711 job->progs[prognum].is_stopped = 1;
713 if (job->stopped_progs == job->num_progs) {
714 printf(JOB_STATUS_FORMAT, job->jobid, "Stopped",
720 if (childpid == -1 && errno != ECHILD)
721 perror_msg("waitpid");
724 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
725 * and stderr if they are redirected. */
726 static int setup_redirects(struct child_prog *prog, int squirrel[])
731 struct redir_struct *redir = prog->redirects;
733 for (i = 0; i < prog->num_redirects; i++, redir++) {
734 switch (redir->type) {
738 case REDIRECT_OVERWRITE:
739 mode = O_WRONLY | O_CREAT | O_TRUNC;
741 case REDIRECT_APPEND:
742 mode = O_WRONLY | O_CREAT | O_APPEND;
746 openfd = open(redir->filename, mode, 0666);
748 /* this could get lost if stderr has been redirected, but
749 bash and ash both lose it as well (though zsh doesn't!) */
750 error_msg("error opening %s: %s", redir->filename,
755 if (openfd != redir->fd) {
756 if (squirrel && redir->fd < 3) {
757 squirrel[redir->fd] = dup(redir->fd);
759 dup2(openfd, redir->fd);
767 static void restore_redirects(int squirrel[])
770 for (i=0; i<3; i++) {
773 /* No error checking. I sure wouldn't know what
774 * to do with an error if I found one! */
781 #if defined(BB_FEATURE_SH_SIMPLE_PROMPT)
782 static char* setup_prompt_string(int state)
784 char prompt_str[BUFSIZ];
786 /* Set up the prompt */
789 sprintf(prompt_str, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
791 strcpy(prompt_str,"> ");
794 return(strdup(prompt_str)); /* Must free this memory */
799 static char* setup_prompt_string(int state)
801 char user[9],buf[255],*s;
803 char prompt_str[BUFSIZ];
805 /* Set up the prompt */
807 /* get User Name and setup prompt */
808 strcpy(prompt,( geteuid() != 0 ) ? "$ ":"# ");
809 my_getpwuid(user, geteuid());
812 gethostname(buf, 255);
813 s = strchr(buf, '.');
822 snprintf(prompt_str, BUFSIZ-1, "[%s@%s %s]%s", user, buf,
823 get_last_path_component(cwd), prompt);
825 sprintf(prompt_str, "%s", prompt);
827 return(strdup(prompt_str)); /* Must free this memory */
832 static int get_command(FILE * source, char *command)
836 if (source == NULL) {
837 if (local_pending_command) {
838 /* a command specified (-c option): return it & mark it done */
839 strcpy(command, local_pending_command);
840 free(local_pending_command);
841 local_pending_command = NULL;
847 if (source == stdin) {
848 prompt_str = setup_prompt_string(shell_context);
850 #ifdef BB_FEATURE_SH_COMMAND_EDITING
852 ** enable command line editing only while a command line
853 ** is actually being read; otherwise, we'll end up bequeathing
854 ** atexit() handlers and other unwanted stuff to our
855 ** child processes (rob@sysgo.de)
857 cmdedit_read_input(prompt_str, command);
862 fputs(prompt_str, stdout);
867 if (!fgets(command, BUFSIZ - 2, source)) {
873 /* remove trailing newline */
874 command[strlen(command) - 1] = '\0';
879 #ifdef BB_FEATURE_SH_ENVIRONMENT
880 static char* itoa(register int i)
882 static char a[7]; /* Max 7 ints */
883 register char *b = a + sizeof(a) - 1;
891 *--b = '0' + (i % 10);
901 static void expand_argument(struct child_prog *prog, int *argcPtr,
902 int *argv_alloced_ptr)
904 int argc_l = *argcPtr;
905 int argv_alloced = *argv_alloced_ptr;
909 char *src, *dst, *var;
911 if (argc_l > 1) { /* cmd->glob_result is already initialized */
913 i = prog->glob_result.gl_pathc;
919 #ifdef BB_FEATURE_SH_ENVIRONMENT
920 /* do shell variable substitution */
921 src = prog->argv[argc_l - 1];
922 while((dst = strchr(src,'$')) != NULL){
923 if (!(var = getenv(dst + 1))) {
926 var = itoa(last_return_code);
929 var = itoa(getpid());
938 var = itoa(last_bg_pid);
940 case '0':case '1':case '2':case '3':case '4':
941 case '5':case '6':case '7':case '8':case '9':
943 int index=*(dst + 1)-48;
954 int offset = dst-src;
955 #warning I have a memory leak which needs to be plugged somehow
956 src = (char*)xmalloc(strlen(src)-strlen(dst)+strlen(var)+1);
957 strncpy(src, prog->argv[argc_l -1], offset);
958 safe_strncpy(src+offset, var, strlen(var)+1);
959 /* If there are any remaining $ variables in the src string, put them back */
960 if ((dst = strchr(prog->argv[argc_l -1]+offset+1,'$')) != NULL) {
962 safe_strncpy(src+strlen(src), dst, strlen(dst)+1);
964 prog->argv[argc_l -1] = src;
966 memset(dst, 0, strlen(src)-strlen(dst));
971 if (strpbrk(prog->argv[argc_l - 1],"*[]?")!= NULL){
972 rc = glob(prog->argv[argc_l - 1], flags, NULL, &prog->glob_result);
973 if (rc == GLOB_NOSPACE) {
974 error_msg("out of space during glob operation");
976 } else if (rc == GLOB_NOMATCH ||
977 (!rc && (prog->glob_result.gl_pathc - i) == 1 &&
978 strcmp(prog->argv[argc_l - 1],
979 prog->glob_result.gl_pathv[i]) == 0)) {
980 /* we need to remove whatever \ quoting is still present */
981 src = dst = prog->argv[argc_l - 1];
985 *dst++ = process_escape_sequence(&src);
993 argv_alloced += (prog->glob_result.gl_pathc - i);
994 prog->argv = xrealloc(prog->argv, argv_alloced * sizeof(*prog->argv));
995 memcpy(prog->argv + (argc_l - 1), prog->glob_result.gl_pathv + i,
996 sizeof(*(prog->argv)) * (prog->glob_result.gl_pathc - i));
997 argc_l += (prog->glob_result.gl_pathc - i - 1);
1000 src = dst = prog->argv[argc_l - 1];
1004 *dst++ = process_escape_sequence(&src);
1012 prog->glob_result.gl_pathc=0;
1014 prog->glob_result.gl_pathv=NULL;
1016 *argv_alloced_ptr = argv_alloced;
1020 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
1021 line). If a valid command is found, command_ptr is set to point to
1022 the beginning of the next command (if the original command had more
1023 then one job associated with it) or NULL if no more commands are
1025 static int parse_command(char **command_ptr, struct job *job, int *inbg)
1028 char *return_command = NULL;
1029 char *src, *buf, *chptr;
1036 struct child_prog *prog;
1038 /* skip leading white space */
1039 while (**command_ptr && isspace(**command_ptr))
1042 /* this handles empty lines or leading '#' characters */
1043 if (!**command_ptr || (**command_ptr == '#')) {
1050 job->progs = xmalloc(sizeof(*job->progs));
1052 /* We set the argv elements to point inside of this string. The
1053 memory is freed by free_job(). Allocate twice the original
1054 length in case we need to quote every single character.
1056 Getting clean memory relieves us of the task of NULL
1057 terminating things and makes the rest of this look a bit
1058 cleaner (though it is, admittedly, a tad less efficient) */
1059 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
1063 prog->num_redirects = 0;
1064 prog->redirects = NULL;
1065 prog->free_glob = 0;
1066 prog->is_stopped = 0;
1070 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1071 prog->argv[0] = job->cmdbuf;
1075 while (*src && !done) {
1076 if (quote == *src) {
1082 error_msg("character expected after \\");
1087 /* in shell, "\'" should yield \' */
1088 if (*src != quote) {
1092 } else if (*src == '*' || *src == '?' || *src == '[' ||
1093 *src == ']') *buf++ = '\\';
1095 } else if (isspace(*src)) {
1096 if (*prog->argv[argc_l]) {
1098 /* +1 here leaves room for the NULL which ends argv */
1099 if ((argc_l + 1) == argv_alloced) {
1101 prog->argv = xrealloc(prog->argv,
1102 sizeof(*prog->argv) *
1105 expand_argument(prog, &argc_l, &argv_alloced);
1106 prog->argv[argc_l] = buf;
1115 case '#': /* comment */
1122 case '>': /* redirects */
1124 i = prog->num_redirects++;
1125 prog->redirects = xrealloc(prog->redirects,
1126 sizeof(*prog->redirects) *
1129 prog->redirects[i].fd = -1;
1130 if (buf != prog->argv[argc_l]) {
1131 /* the stuff before this character may be the file number
1133 prog->redirects[i].fd =
1134 strtol(prog->argv[argc_l], &chptr, 10);
1136 if (*chptr && *prog->argv[argc_l]) {
1138 expand_argument(prog, &argc_l, &argv_alloced);
1139 prog->argv[argc_l] = buf;
1143 if (prog->redirects[i].fd == -1) {
1145 prog->redirects[i].fd = 1;
1147 prog->redirects[i].fd = 0;
1150 if (*src++ == '>') {
1152 prog->redirects[i].type =
1153 REDIRECT_APPEND, src++;
1155 prog->redirects[i].type = REDIRECT_OVERWRITE;
1157 prog->redirects[i].type = REDIRECT_INPUT;
1160 /* This isn't POSIX sh compliant. Oh well. */
1162 while (isspace(*chptr))
1166 error_msg("file name expected after %c", *src);
1172 prog->redirects[i].filename = buf;
1173 while (*chptr && !isspace(*chptr))
1176 src = chptr - 1; /* we src++ later */
1177 prog->argv[argc_l] = ++buf;
1180 case '|': /* pipe */
1181 /* finish this command */
1182 if (*prog->argv[argc_l])
1185 error_msg("empty command in pipe");
1190 prog->argv[argc_l] = NULL;
1192 /* and start the next */
1194 job->progs = xrealloc(job->progs,
1195 sizeof(*job->progs) * job->num_progs);
1196 prog = job->progs + (job->num_progs - 1);
1197 prog->num_redirects = 0;
1198 prog->redirects = NULL;
1199 prog->free_glob = 0;
1200 prog->is_stopped = 0;
1205 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1206 prog->argv[0] = ++buf;
1209 while (*src && isspace(*src))
1213 error_msg("empty command in pipe");
1218 src--; /* we'll ++ it at the end of the loop */
1222 case '&': /* background */
1224 case ';': /* multiple commands */
1226 return_command = *command_ptr + (src - *command_ptr) + 1;
1229 #ifdef BB_FEATURE_SH_BACKTICKS
1231 /* Exec a backtick-ed command */
1232 /* Besides any previous brokenness, I have not
1233 * updated backtick handling for close_me support.
1234 * I don't know if it needs it or not. -- LRD */
1236 char* charptr1=NULL, *charptr2;
1239 struct jobset njob_list = { NULL, NULL };
1243 ptr=strchr(++src, '`');
1245 fprintf(stderr, "Unmatched '`' in command\n");
1250 /* Make some space to hold just the backticked command */
1251 charptr1 = charptr2 = xmalloc(1+ptr-src);
1252 memcpy(charptr1, src, ptr-src);
1253 charptr1[ptr-src] = '\0';
1254 newjob = xmalloc(sizeof(struct job));
1255 newjob->job_list = &njob_list;
1256 /* Now parse and run the backticked command */
1257 if (!parse_command(&charptr1, newjob, inbg)
1258 && newjob->num_progs) {
1260 run_command(newjob, 0, pipefd);
1262 checkjobs(job->job_list);
1263 free_job(newjob); /* doesn't actually free newjob,
1264 looks like a memory leak */
1267 /* Make a copy of any stuff left over in the command
1268 * line after the second backtick */
1269 charptr2 = xmalloc(strlen(ptr)+1);
1270 memcpy(charptr2, ptr+1, strlen(ptr));
1273 /* Copy the output from the backtick-ed command into the
1274 * command line, making extra room as needed */
1276 charptr1 = xmalloc(BUFSIZ);
1277 while ( (size=full_read(pipefd[0], charptr1, BUFSIZ-1)) >0) {
1278 int newsize=src - *command_ptr + size + 1 + strlen(charptr2);
1279 if (newsize > BUFSIZ) {
1280 *command_ptr=xrealloc(*command_ptr, newsize);
1282 memcpy(src, charptr1, size);
1290 /* Now paste into the *command_ptr all the stuff
1291 * leftover after the second backtick */
1292 memcpy(src, charptr2, strlen(charptr2)+1);
1295 /* Now recursively call parse_command to deal with the new
1296 * and improved version of the command line with the backtick
1297 * results expanded in place... */
1299 struct jobset *jl=job->job_list;
1303 return(parse_command(command_ptr, job, inbg));
1306 #endif // BB_FEATURE_SH_BACKTICKS
1311 /* This is currently a little broken... */
1312 #ifdef HANDLE_CONTINUATION_CHARS
1313 /* They fed us a continuation char, so continue reading stuff
1314 * on the next line, then tack that onto the end of the current
1318 printf("erik: found a continue char at EOL...\n");
1319 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1320 if (get_command(input, command)) {
1321 error_msg("character expected after \\");
1326 newsize = strlen(*command_ptr) + strlen(command) + 2;
1327 if (newsize > BUFSIZ) {
1328 printf("erik: doing realloc\n");
1329 *command_ptr=xrealloc(*command_ptr, newsize);
1331 printf("erik: A: *command_ptr='%s'\n", *command_ptr);
1332 memcpy(--src, command, strlen(command));
1333 printf("erik: B: *command_ptr='%s'\n", *command_ptr);
1337 error_msg("character expected after \\");
1343 if (*src == '*' || *src == '[' || *src == ']'
1344 || *src == '?') *buf++ = '\\';
1353 if (*prog->argv[argc_l]) {
1355 expand_argument(prog, &argc_l, &argv_alloced);
1361 prog->argv[argc_l] = NULL;
1363 if (!return_command) {
1364 job->text = xmalloc(strlen(*command_ptr) + 1);
1365 strcpy(job->text, *command_ptr);
1367 /* This leaves any trailing spaces, which is a bit sloppy */
1368 count = return_command - *command_ptr;
1369 job->text = xmalloc(count + 1);
1370 strncpy(job->text, *command_ptr, count);
1371 job->text[count] = '\0';
1374 *command_ptr = return_command;
1379 /* Run the child_prog, no matter what kind of command it uses.
1381 static int pseudo_exec(struct child_prog *child)
1383 struct built_in_command *x;
1384 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1388 /* Check if the command matches any of the non-forking builtins.
1389 * Depending on context, this might be redundant. But it's
1390 * easier to waste a few CPU cycles than it is to figure out
1391 * if this is one of those cases.
1393 for (x = bltins; x->cmd; x++) {
1394 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1395 exit(x->function(child));
1399 /* Check if the command matches any of the forking builtins. */
1400 for (x = bltins_forking; x->cmd; x++) {
1401 if (strcmp(child->argv[0], x->cmd) == 0) {
1403 exit (x->function(child));
1406 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1407 /* Check if the command matches any busybox internal
1408 * commands ("applets") here. Following discussions from
1409 * November 2000 on busybox@opensource.lineo.com, don't use
1410 * get_last_path_component(). This way explicit (with
1411 * slashes) filenames will never be interpreted as an
1412 * applet, just like with builtins. This way the user can
1413 * override an applet with an explicit filename reference.
1414 * The only downside to this change is that an explicit
1415 * /bin/foo invocation will fork and exec /bin/foo, even if
1416 * /bin/foo is a symlink to busybox.
1418 name = child->argv[0];
1420 #ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1421 /* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then
1422 * if you run /bin/cat, it will use BusyBox cat even if
1423 * /bin/cat exists on the filesystem and is _not_ busybox.
1424 * Some systems want this, others do not. Choose wisely. :-)
1426 name = get_last_path_component(name);
1430 char** argv=child->argv;
1432 for(argc_l=0;*argv!=NULL; argv++, argc_l++);
1434 run_applet_by_name(name, argc_l, child->argv);
1438 execvp(child->argv[0], child->argv);
1439 perror_msg_and_die("%s", child->argv[0]);
1442 static void insert_job(struct job *newjob, int inbg)
1445 struct jobset *job_list=newjob->job_list;
1447 /* find the ID for thejob to use */
1449 for (thejob = job_list->head; thejob; thejob = thejob->next)
1450 if (thejob->jobid >= newjob->jobid)
1451 newjob->jobid = thejob->jobid + 1;
1453 /* add thejob to the list of running jobs */
1454 if (!job_list->head) {
1455 thejob = job_list->head = xmalloc(sizeof(*thejob));
1457 for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1458 thejob->next = xmalloc(sizeof(*thejob));
1459 thejob = thejob->next;
1462 *thejob = *newjob; /* physically copy the struct job */
1463 thejob->next = NULL;
1464 thejob->running_progs = thejob->num_progs;
1465 thejob->stopped_progs = 0;
1468 /* we don't wait for background thejobs to return -- append it
1469 to the list of backgrounded thejobs and leave it alone */
1470 printf("[%d] %d\n", thejob->jobid,
1471 newjob->progs[newjob->num_progs - 1].pid);
1472 #ifdef BB_FEATURE_SH_ENVIRONMENT
1473 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1476 newjob->job_list->fg = thejob;
1478 /* move the new process group into the foreground */
1479 /* suppress messages when run from /linuxrc mag@sysgo.de */
1480 if (tcsetpgrp(0, newjob->pgrp) && errno != ENOTTY)
1481 perror_msg("tcsetpgrp");
1485 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1487 /* struct job *thejob; */
1489 int nextin, nextout;
1490 int pipefds[2]; /* pipefd[0] is for reading */
1491 struct built_in_command *x;
1492 struct child_prog *child;
1494 nextin = 0, nextout = 1;
1495 for (i = 0; i < newjob->num_progs; i++) {
1496 child = & (newjob->progs[i]);
1498 if ((i + 1) < newjob->num_progs) {
1499 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1500 nextout = pipefds[1];
1502 if (outpipe[1]!=-1) {
1503 nextout = outpipe[1];
1509 #ifdef BB_FEATURE_SH_ENVIRONMENT
1510 if (show_x_trace==TRUE) {
1513 for (j = 0; child->argv[j]; j++) {
1515 fputs(child->argv[j], stderr);
1517 fputc('\n', stderr);
1521 /* Check if the command matches any non-forking builtins,
1522 * but only if this is a simple command.
1523 * Non-forking builtins within pipes have to fork anyway,
1524 * and are handled in pseudo_exec. "echo foo | read bar"
1525 * is doomed to failure, and doesn't work on bash, either.
1527 if (newjob->num_progs == 1) {
1528 for (x = bltins; x->cmd; x++) {
1529 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1530 int squirrel[] = {-1, -1, -1};
1532 setup_redirects(child, squirrel);
1533 rcode = x->function(child);
1534 restore_redirects(squirrel);
1540 if (!(child->pid = fork())) {
1541 signal(SIGTTOU, SIG_DFL);
1545 if (outpipe[1]!=-1) {
1555 dup2(nextout, 2); /* Really? */
1560 /* explicit redirects override pipes */
1561 setup_redirects(child,NULL);
1565 if (outpipe[1]!=-1) {
1569 /* put our child in the process group whose leader is the
1570 first process in this pipe */
1571 setpgid(child->pid, newjob->progs[0].pid);
1577 /* If there isn't another process, nextin is garbage
1578 but it doesn't matter */
1579 nextin = pipefds[0];
1582 newjob->pgrp = newjob->progs[0].pid;
1584 insert_job(newjob, inbg);
1589 static int busy_loop(FILE * input)
1592 char *next_command = NULL;
1598 newjob.job_list = &job_list;
1599 newjob.job_context = DEFAULT_CONTEXT;
1601 /* save current owner of TTY so we can restore it on exit */
1602 parent_pgrp = tcgetpgrp(0);
1604 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1606 /* don't pay any attention to this signal; it just confuses
1607 things and isn't really meant for shells anyway */
1608 signal(SIGTTOU, SIG_IGN);
1612 /* no job is in the foreground */
1614 /* see if any background processes have exited */
1615 checkjobs(&job_list);
1617 if (!next_command) {
1618 if (get_command(input, command))
1620 next_command = command;
1623 if (!parse_command(&next_command, &newjob, &inbg) &&
1625 int pipefds[2] = {-1,-1};
1626 debug_printf( "job=%p being fed to run_command by busy_loop()'\n", &newjob);
1627 run_command(&newjob, inbg, pipefds);
1631 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1632 next_command = NULL;
1635 /* a job is running in the foreground; wait for it */
1637 while (!job_list.fg->progs[i].pid ||
1638 job_list.fg->progs[i].is_stopped == 1) i++;
1640 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0)
1641 perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1643 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1644 /* the child exited */
1645 job_list.fg->running_progs--;
1646 job_list.fg->progs[i].pid = 0;
1648 #ifdef BB_FEATURE_SH_ENVIRONMENT
1649 last_return_code=WEXITSTATUS(status);
1651 debug_printf("'%s' exited -- return code %d\n",
1652 job_list.fg->text, last_return_code);
1653 if (!job_list.fg->running_progs) {
1655 remove_job(&job_list, job_list.fg);
1659 /* the child was stopped */
1660 job_list.fg->stopped_progs++;
1661 job_list.fg->progs[i].is_stopped = 1;
1663 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1664 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1665 "Stopped", job_list.fg->text);
1671 /* move the shell to the foreground */
1672 /* suppress messages when run from /linuxrc mag@sysgo.de */
1673 if (tcsetpgrp(0, getpid()) && errno != ENOTTY)
1674 perror_msg("tcsetpgrp");
1680 /* return controlling TTY back to parent process group before exiting */
1681 if (tcsetpgrp(0, parent_pgrp))
1682 perror_msg("tcsetpgrp");
1684 /* return exit status if called with "-c" */
1685 if (input == NULL && WIFEXITED(status))
1686 return WEXITSTATUS(status);
1692 #ifdef BB_FEATURE_CLEAN_UP
1693 void free_memory(void)
1697 if (local_pending_command)
1698 free(local_pending_command);
1700 if (job_list.fg && !job_list.fg->running_progs) {
1701 remove_job(&job_list, job_list.fg);
1707 int shell_main(int argc_l, char **argv_l)
1709 int opt, interactive=FALSE;
1710 FILE *input = stdin;
1716 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1717 /* These variables need re-initializing when recursing */
1718 local_pending_command = NULL;
1719 job_list.head = NULL;
1721 #ifdef BB_FEATURE_SH_ENVIRONMENT
1723 last_return_code=-1;
1728 if (argv[0] && argv[0][0] == '-') {
1730 prof_input = fopen("/etc/profile", "r");
1732 printf( "Couldn't open file '/etc/profile'\n");
1734 int tmp_fd = fileno(prof_input);
1736 /* Now run the file */
1737 busy_loop(prof_input);
1739 mark_closed(tmp_fd);
1743 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1747 if (local_pending_command != 0)
1748 error_msg_and_die("multiple -c arguments");
1749 local_pending_command = xstrdup(argv[optind]);
1753 #ifdef BB_FEATURE_SH_ENVIRONMENT
1755 show_x_trace = TRUE;
1765 /* A shell is interactive if the `-i' flag was given, or if all of
1766 * the following conditions are met:
1768 * no arguments remaining or the -s flag given
1769 * standard input is a terminal
1770 * standard output is a terminal
1771 * Refer to Posix.2, the description of the `sh' utility. */
1772 if (argv[optind]==NULL && input==stdin &&
1773 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
1776 if (interactive==TRUE) {
1777 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1778 /* Looks like they want an interactive shell */
1779 printf( "\n\nBusyBox v%s (%s) Built-in shell (lash)\n", BB_VER, BB_BT);
1780 printf( "Enter 'help' for a list of built-in commands.\n\n");
1781 } else if (local_pending_command==NULL) {
1782 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1783 input = xfopen(argv[optind], "r");
1784 mark_open(fileno(input)); /* be lazy, never mark this closed */
1787 /* initialize the cwd -- this is never freed...*/
1788 cwd=(char*)xmalloc(sizeof(char)*MAX_LINE+1);
1789 getcwd(cwd, sizeof(char)*MAX_LINE);
1791 #ifdef BB_FEATURE_CLEAN_UP
1792 atexit(free_memory);
1795 return (busy_loop(input));