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...
61 #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 /* do shell variable substitution */
920 if(*prog->argv[argc_l - 1] == '$') {
921 if ((var = getenv(prog->argv[argc_l - 1] + 1))) {
922 prog->argv[argc_l - 1] = var;
924 #ifdef BB_FEATURE_SH_ENVIRONMENT
926 switch(*(prog->argv[argc_l - 1] + 1)) {
928 prog->argv[argc_l - 1] = itoa(last_return_code);
931 prog->argv[argc_l - 1] = itoa(getpid());
934 prog->argv[argc_l - 1] = itoa(argc-1);
938 *(prog->argv[argc_l - 1])='\0';
940 prog->argv[argc_l - 1] = itoa(last_bg_pid);
942 case '0':case '1':case '2':case '3':case '4':
943 case '5':case '6':case '7':case '8':case '9':
945 int index=*(prog->argv[argc_l - 1] + 1)-48;
947 *(prog->argv[argc_l - 1])='\0';
949 prog->argv[argc_l - 1] = argv[index];
958 if (strpbrk(prog->argv[argc_l - 1],"*[]?")!= NULL){
959 rc = glob(prog->argv[argc_l - 1], flags, NULL, &prog->glob_result);
960 if (rc == GLOB_NOSPACE) {
961 error_msg("out of space during glob operation");
963 } else if (rc == GLOB_NOMATCH ||
964 (!rc && (prog->glob_result.gl_pathc - i) == 1 &&
965 strcmp(prog->argv[argc_l - 1],
966 prog->glob_result.gl_pathv[i]) == 0)) {
967 /* we need to remove whatever \ quoting is still present */
968 src = dst = prog->argv[argc_l - 1];
972 *dst++ = process_escape_sequence(&src);
980 argv_alloced += (prog->glob_result.gl_pathc - i);
981 prog->argv = xrealloc(prog->argv, argv_alloced * sizeof(*prog->argv));
982 memcpy(prog->argv + (argc_l - 1), prog->glob_result.gl_pathv + i,
983 sizeof(*(prog->argv)) * (prog->glob_result.gl_pathc - i));
984 argc_l += (prog->glob_result.gl_pathc - i - 1);
987 src = dst = prog->argv[argc_l - 1];
991 *dst++ = process_escape_sequence(&src);
999 prog->glob_result.gl_pathc=0;
1001 prog->glob_result.gl_pathv=NULL;
1003 *argv_alloced_ptr = argv_alloced;
1007 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
1008 line). If a valid command is found, command_ptr is set to point to
1009 the beginning of the next command (if the original command had more
1010 then one job associated with it) or NULL if no more commands are
1012 static int parse_command(char **command_ptr, struct job *job, int *inbg)
1015 char *return_command = NULL;
1016 char *src, *buf, *chptr;
1023 struct child_prog *prog;
1025 /* skip leading white space */
1026 while (**command_ptr && isspace(**command_ptr))
1029 /* this handles empty lines or leading '#' characters */
1030 if (!**command_ptr || (**command_ptr == '#')) {
1037 job->progs = xmalloc(sizeof(*job->progs));
1039 /* We set the argv elements to point inside of this string. The
1040 memory is freed by free_job(). Allocate twice the original
1041 length in case we need to quote every single character.
1043 Getting clean memory relieves us of the task of NULL
1044 terminating things and makes the rest of this look a bit
1045 cleaner (though it is, admittedly, a tad less efficient) */
1046 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
1050 prog->num_redirects = 0;
1051 prog->redirects = NULL;
1052 prog->free_glob = 0;
1053 prog->is_stopped = 0;
1057 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1058 prog->argv[0] = job->cmdbuf;
1062 while (*src && !done) {
1063 if (quote == *src) {
1069 error_msg("character expected after \\");
1074 /* in shell, "\'" should yield \' */
1075 if (*src != quote) {
1079 } else if (*src == '*' || *src == '?' || *src == '[' ||
1080 *src == ']') *buf++ = '\\';
1082 } else if (isspace(*src)) {
1083 if (*prog->argv[argc_l]) {
1085 /* +1 here leaves room for the NULL which ends argv */
1086 if ((argc_l + 1) == argv_alloced) {
1088 prog->argv = xrealloc(prog->argv,
1089 sizeof(*prog->argv) *
1092 expand_argument(prog, &argc_l, &argv_alloced);
1093 prog->argv[argc_l] = buf;
1102 case '#': /* comment */
1109 case '>': /* redirects */
1111 i = prog->num_redirects++;
1112 prog->redirects = xrealloc(prog->redirects,
1113 sizeof(*prog->redirects) *
1116 prog->redirects[i].fd = -1;
1117 if (buf != prog->argv[argc_l]) {
1118 /* the stuff before this character may be the file number
1120 prog->redirects[i].fd =
1121 strtol(prog->argv[argc_l], &chptr, 10);
1123 if (*chptr && *prog->argv[argc_l]) {
1125 expand_argument(prog, &argc_l, &argv_alloced);
1126 prog->argv[argc_l] = buf;
1130 if (prog->redirects[i].fd == -1) {
1132 prog->redirects[i].fd = 1;
1134 prog->redirects[i].fd = 0;
1137 if (*src++ == '>') {
1139 prog->redirects[i].type =
1140 REDIRECT_APPEND, src++;
1142 prog->redirects[i].type = REDIRECT_OVERWRITE;
1144 prog->redirects[i].type = REDIRECT_INPUT;
1147 /* This isn't POSIX sh compliant. Oh well. */
1149 while (isspace(*chptr))
1153 error_msg("file name expected after %c", *src);
1159 prog->redirects[i].filename = buf;
1160 while (*chptr && !isspace(*chptr))
1163 src = chptr - 1; /* we src++ later */
1164 prog->argv[argc_l] = ++buf;
1167 case '|': /* pipe */
1168 /* finish this command */
1169 if (*prog->argv[argc_l])
1172 error_msg("empty command in pipe");
1177 prog->argv[argc_l] = NULL;
1179 /* and start the next */
1181 job->progs = xrealloc(job->progs,
1182 sizeof(*job->progs) * job->num_progs);
1183 prog = job->progs + (job->num_progs - 1);
1184 prog->num_redirects = 0;
1185 prog->redirects = NULL;
1186 prog->free_glob = 0;
1187 prog->is_stopped = 0;
1192 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1193 prog->argv[0] = ++buf;
1196 while (*src && isspace(*src))
1200 error_msg("empty command in pipe");
1205 src--; /* we'll ++ it at the end of the loop */
1209 case '&': /* background */
1211 case ';': /* multiple commands */
1213 return_command = *command_ptr + (src - *command_ptr) + 1;
1216 #ifdef BB_FEATURE_SH_BACKTICKS
1218 /* Exec a backtick-ed command */
1219 /* Besides any previous brokenness, I have not
1220 * updated backtick handling for close_me support.
1221 * I don't know if it needs it or not. -- LRD */
1223 char* charptr1=NULL, *charptr2;
1226 struct jobset njob_list = { NULL, NULL };
1230 ptr=strchr(++src, '`');
1232 fprintf(stderr, "Unmatched '`' in command\n");
1237 /* Make some space to hold just the backticked command */
1238 charptr1 = charptr2 = xmalloc(1+ptr-src);
1239 memcpy(charptr1, src, ptr-src);
1240 charptr1[ptr-src] = '\0';
1241 newjob = xmalloc(sizeof(struct job));
1242 newjob->job_list = &njob_list;
1243 /* Now parse and run the backticked command */
1244 if (!parse_command(&charptr1, newjob, inbg)
1245 && newjob->num_progs) {
1247 run_command(newjob, 0, pipefd);
1249 checkjobs(job->job_list);
1250 free_job(newjob); /* doesn't actually free newjob,
1251 looks like a memory leak */
1254 /* Make a copy of any stuff left over in the command
1255 * line after the second backtick */
1256 charptr2 = xmalloc(strlen(ptr)+1);
1257 memcpy(charptr2, ptr+1, strlen(ptr));
1260 /* Copy the output from the backtick-ed command into the
1261 * command line, making extra room as needed */
1263 charptr1 = xmalloc(BUFSIZ);
1264 while ( (size=full_read(pipefd[0], charptr1, BUFSIZ-1)) >0) {
1265 int newsize=src - *command_ptr + size + 1 + strlen(charptr2);
1266 if (newsize > BUFSIZ) {
1267 *command_ptr=xrealloc(*command_ptr, newsize);
1269 memcpy(src, charptr1, size);
1277 /* Now paste into the *command_ptr all the stuff
1278 * leftover after the second backtick */
1279 memcpy(src, charptr2, strlen(charptr2)+1);
1282 /* Now recursively call parse_command to deal with the new
1283 * and improved version of the command line with the backtick
1284 * results expanded in place... */
1286 struct jobset *jl=job->job_list;
1290 return(parse_command(command_ptr, job, inbg));
1293 #endif // BB_FEATURE_SH_BACKTICKS
1298 /* This is currently a little broken... */
1299 #ifdef HANDLE_CONTINUATION_CHARS
1300 /* They fed us a continuation char, so continue reading stuff
1301 * on the next line, then tack that onto the end of the current
1305 printf("erik: found a continue char at EOL...\n");
1306 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1307 if (get_command(input, command)) {
1308 error_msg("character expected after \\");
1313 newsize = strlen(*command_ptr) + strlen(command) + 2;
1314 if (newsize > BUFSIZ) {
1315 printf("erik: doing realloc\n");
1316 *command_ptr=xrealloc(*command_ptr, newsize);
1318 printf("erik: A: *command_ptr='%s'\n", *command_ptr);
1319 memcpy(--src, command, strlen(command));
1320 printf("erik: B: *command_ptr='%s'\n", *command_ptr);
1324 error_msg("character expected after \\");
1330 if (*src == '*' || *src == '[' || *src == ']'
1331 || *src == '?') *buf++ = '\\';
1340 if (*prog->argv[argc_l]) {
1342 expand_argument(prog, &argc_l, &argv_alloced);
1348 prog->argv[argc_l] = NULL;
1350 if (!return_command) {
1351 job->text = xmalloc(strlen(*command_ptr) + 1);
1352 strcpy(job->text, *command_ptr);
1354 /* This leaves any trailing spaces, which is a bit sloppy */
1355 count = return_command - *command_ptr;
1356 job->text = xmalloc(count + 1);
1357 strncpy(job->text, *command_ptr, count);
1358 job->text[count] = '\0';
1361 *command_ptr = return_command;
1366 /* Run the child_prog, no matter what kind of command it uses.
1368 static int pseudo_exec(struct child_prog *child)
1370 struct built_in_command *x;
1371 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1375 /* Check if the command matches any of the non-forking builtins.
1376 * Depending on context, this might be redundant. But it's
1377 * easier to waste a few CPU cycles than it is to figure out
1378 * if this is one of those cases.
1380 for (x = bltins; x->cmd; x++) {
1381 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1382 exit(x->function(child));
1386 /* Check if the command matches any of the forking builtins. */
1387 for (x = bltins_forking; x->cmd; x++) {
1388 if (strcmp(child->argv[0], x->cmd) == 0) {
1390 exit (x->function(child));
1393 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1394 /* Check if the command matches any busybox internal
1395 * commands ("applets") here. Following discussions from
1396 * November 2000 on busybox@opensource.lineo.com, don't use
1397 * get_last_path_component(). This way explicit (with
1398 * slashes) filenames will never be interpreted as an
1399 * applet, just like with builtins. This way the user can
1400 * override an applet with an explicit filename reference.
1401 * The only downside to this change is that an explicit
1402 * /bin/foo invocation will fork and exec /bin/foo, even if
1403 * /bin/foo is a symlink to busybox.
1405 name = child->argv[0];
1407 #ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1408 /* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then
1409 * if you run /bin/cat, it will use BusyBox cat even if
1410 * /bin/cat exists on the filesystem and is _not_ busybox.
1411 * Some systems want this, others do not. Choose wisely. :-)
1413 name = get_last_path_component(name);
1417 char** argv=child->argv;
1419 for(argc_l=0;*argv!=NULL; argv++, argc_l++);
1421 run_applet_by_name(name, argc_l, child->argv);
1425 execvp(child->argv[0], child->argv);
1426 perror_msg_and_die("%s", child->argv[0]);
1429 static void insert_job(struct job *newjob, int inbg)
1432 struct jobset *job_list=newjob->job_list;
1434 /* find the ID for thejob to use */
1436 for (thejob = job_list->head; thejob; thejob = thejob->next)
1437 if (thejob->jobid >= newjob->jobid)
1438 newjob->jobid = thejob->jobid + 1;
1440 /* add thejob to the list of running jobs */
1441 if (!job_list->head) {
1442 thejob = job_list->head = xmalloc(sizeof(*thejob));
1444 for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1445 thejob->next = xmalloc(sizeof(*thejob));
1446 thejob = thejob->next;
1449 *thejob = *newjob; /* physically copy the struct job */
1450 thejob->next = NULL;
1451 thejob->running_progs = thejob->num_progs;
1452 thejob->stopped_progs = 0;
1455 /* we don't wait for background thejobs to return -- append it
1456 to the list of backgrounded thejobs and leave it alone */
1457 printf("[%d] %d\n", thejob->jobid,
1458 newjob->progs[newjob->num_progs - 1].pid);
1459 #ifdef BB_FEATURE_SH_ENVIRONMENT
1460 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1463 newjob->job_list->fg = thejob;
1465 /* move the new process group into the foreground */
1466 /* suppress messages when run from /linuxrc mag@sysgo.de */
1467 if (tcsetpgrp(0, newjob->pgrp) && errno != ENOTTY)
1468 perror_msg("tcsetpgrp");
1472 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1474 /* struct job *thejob; */
1476 int nextin, nextout;
1477 int pipefds[2]; /* pipefd[0] is for reading */
1478 struct built_in_command *x;
1479 struct child_prog *child;
1481 nextin = 0, nextout = 1;
1482 for (i = 0; i < newjob->num_progs; i++) {
1483 child = & (newjob->progs[i]);
1485 if ((i + 1) < newjob->num_progs) {
1486 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1487 nextout = pipefds[1];
1489 if (outpipe[1]!=-1) {
1490 nextout = outpipe[1];
1496 #ifdef BB_FEATURE_SH_ENVIRONMENT
1497 if (show_x_trace==TRUE) {
1500 for (j = 0; child->argv[j]; j++) {
1502 fputs(child->argv[j], stderr);
1504 fputc('\n', stderr);
1508 /* Check if the command matches any non-forking builtins,
1509 * but only if this is a simple command.
1510 * Non-forking builtins within pipes have to fork anyway,
1511 * and are handled in pseudo_exec. "echo foo | read bar"
1512 * is doomed to failure, and doesn't work on bash, either.
1514 if (newjob->num_progs == 1) {
1515 for (x = bltins; x->cmd; x++) {
1516 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1517 int squirrel[] = {-1, -1, -1};
1519 setup_redirects(child, squirrel);
1520 rcode = x->function(child);
1521 restore_redirects(squirrel);
1527 if (!(child->pid = fork())) {
1528 signal(SIGTTOU, SIG_DFL);
1532 if (outpipe[1]!=-1) {
1542 dup2(nextout, 2); /* Really? */
1547 /* explicit redirects override pipes */
1548 setup_redirects(child,NULL);
1552 if (outpipe[1]!=-1) {
1556 /* put our child in the process group whose leader is the
1557 first process in this pipe */
1558 setpgid(child->pid, newjob->progs[0].pid);
1564 /* If there isn't another process, nextin is garbage
1565 but it doesn't matter */
1566 nextin = pipefds[0];
1569 newjob->pgrp = newjob->progs[0].pid;
1571 insert_job(newjob, inbg);
1576 static int busy_loop(FILE * input)
1579 char *next_command = NULL;
1585 newjob.job_list = &job_list;
1586 newjob.job_context = DEFAULT_CONTEXT;
1588 /* save current owner of TTY so we can restore it on exit */
1589 parent_pgrp = tcgetpgrp(0);
1591 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1593 /* don't pay any attention to this signal; it just confuses
1594 things and isn't really meant for shells anyway */
1595 signal(SIGTTOU, SIG_IGN);
1599 /* no job is in the foreground */
1601 /* see if any background processes have exited */
1602 checkjobs(&job_list);
1604 if (!next_command) {
1605 if (get_command(input, command))
1607 next_command = command;
1610 if (!parse_command(&next_command, &newjob, &inbg) &&
1612 int pipefds[2] = {-1,-1};
1613 debug_printf( "job=%p being fed to run_command by busy_loop()'\n", &newjob);
1614 run_command(&newjob, inbg, pipefds);
1618 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1619 next_command = NULL;
1622 /* a job is running in the foreground; wait for it */
1624 while (!job_list.fg->progs[i].pid ||
1625 job_list.fg->progs[i].is_stopped == 1) i++;
1627 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0)
1628 perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1630 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1631 /* the child exited */
1632 job_list.fg->running_progs--;
1633 job_list.fg->progs[i].pid = 0;
1635 #ifdef BB_FEATURE_SH_ENVIRONMENT
1636 last_return_code=WEXITSTATUS(status);
1638 debug_printf("'%s' exited -- return code %d\n",
1639 job_list.fg->text, last_return_code);
1640 if (!job_list.fg->running_progs) {
1642 remove_job(&job_list, job_list.fg);
1646 /* the child was stopped */
1647 job_list.fg->stopped_progs++;
1648 job_list.fg->progs[i].is_stopped = 1;
1650 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1651 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1652 "Stopped", job_list.fg->text);
1658 /* move the shell to the foreground */
1659 /* suppress messages when run from /linuxrc mag@sysgo.de */
1660 if (tcsetpgrp(0, getpid()) && errno != ENOTTY)
1661 perror_msg("tcsetpgrp");
1667 /* return controlling TTY back to parent process group before exiting */
1668 if (tcsetpgrp(0, parent_pgrp))
1669 perror_msg("tcsetpgrp");
1671 /* return exit status if called with "-c" */
1672 if (input == NULL && WIFEXITED(status))
1673 return WEXITSTATUS(status);
1679 #ifdef BB_FEATURE_CLEAN_UP
1680 void free_memory(void)
1684 if (local_pending_command)
1685 free(local_pending_command);
1687 if (job_list.fg && !job_list.fg->running_progs) {
1688 remove_job(&job_list, job_list.fg);
1694 int shell_main(int argc_l, char **argv_l)
1696 int opt, interactive=FALSE;
1697 FILE *input = stdin;
1703 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1704 /* These variables need re-initializing when recursing */
1705 local_pending_command = NULL;
1706 job_list.head = NULL;
1708 #ifdef BB_FEATURE_SH_ENVIRONMENT
1710 last_return_code=-1;
1715 if (argv[0] && argv[0][0] == '-') {
1717 prof_input = fopen("/etc/profile", "r");
1719 printf( "Couldn't open file '/etc/profile'\n");
1721 int tmp_fd = fileno(prof_input);
1723 /* Now run the file */
1724 busy_loop(prof_input);
1726 mark_closed(tmp_fd);
1730 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1734 if (local_pending_command != 0)
1735 error_msg_and_die("multiple -c arguments");
1736 local_pending_command = xstrdup(argv[optind]);
1740 #ifdef BB_FEATURE_SH_ENVIRONMENT
1742 show_x_trace = TRUE;
1752 /* A shell is interactive if the `-i' flag was given, or if all of
1753 * the following conditions are met:
1755 * no arguments remaining or the -s flag given
1756 * standard input is a terminal
1757 * standard output is a terminal
1758 * Refer to Posix.2, the description of the `sh' utility. */
1759 if (argv[optind]==NULL && input==stdin &&
1760 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
1763 if (interactive==TRUE) {
1764 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1765 /* Looks like they want an interactive shell */
1766 printf( "\n\nBusyBox v%s (%s) Built-in shell (lash)\n", BB_VER, BB_BT);
1767 printf( "Enter 'help' for a list of built-in commands.\n\n");
1768 } else if (local_pending_command==NULL) {
1769 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1770 input = xfopen(argv[optind], "r");
1771 mark_open(fileno(input)); /* be lazy, never mark this closed */
1774 /* initialize the cwd -- this is never freed...*/
1775 cwd=(char*)xmalloc(sizeof(char)*MAX_LINE+1);
1776 getcwd(cwd, sizeof(char)*MAX_LINE);
1778 #ifdef BB_FEATURE_CLEAN_UP
1779 atexit(free_memory);
1782 return (busy_loop(input));