1 /* vi: set sw=4 ts=4: */
3 * lash -- the BusyBox Lame-Ass SHell
5 * Copyright (C) 1999,2000 by Lineo, inc. and Erik Andersen
6 * Copyright (C) 1999,2000,2001 by Erik Andersen <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 /* This shell's parsing engine is officially at a dead-end. Future
29 * work shell work should be done using hush, msh, or ash. This is
30 * still a very useful, small shell -- it just don't need any more
31 * features beyond what it already has...
34 //For debugging/development on the shell only...
45 #include <sys/ioctl.h>
53 #ifdef CONFIG_LOCALE_SUPPORT
58 #define expand_t glob_t
61 static const int MAX_READ = 128; /* size of input buffer for `read' builtin */
62 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
65 enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
69 static const unsigned int DEFAULT_CONTEXT=0x1;
70 static const unsigned int IF_TRUE_CONTEXT=0x2;
71 static const unsigned int IF_FALSE_CONTEXT=0x4;
72 static const unsigned int THEN_EXP_CONTEXT=0x8;
73 static const unsigned int ELSE_EXP_CONTEXT=0x10;
77 struct job *head; /* head of list of running jobs */
78 struct job *fg; /* current foreground job */
82 enum redir_type type; /* type of redirection */
83 int fd; /* file descriptor being redirected */
84 char *filename; /* file to redirect fd to */
88 pid_t pid; /* 0 if exited */
89 char **argv; /* program name and arguments */
90 int num_redirects; /* elements in redirection array */
91 struct redir_struct *redirects; /* I/O redirects */
92 int is_stopped; /* is the program currently running? */
93 struct job *family; /* pointer back to the child's parent job */
97 int jobid; /* job number */
98 int num_progs; /* total number of programs in job */
99 int running_progs; /* number of programs running */
100 char *text; /* name of job */
101 char *cmdbuf; /* buffer various argv's point into */
102 pid_t pgrp; /* process group ID for the job */
103 struct child_prog *progs; /* array of programs in job */
104 struct job *next; /* to track background commands */
105 int stopped_progs; /* number of programs alive, but stopped */
106 unsigned int job_context; /* bitmask defining current context */
107 struct jobset *job_list;
110 struct built_in_command {
111 char *cmd; /* name */
112 char *descr; /* description */
113 int (*function) (struct child_prog *); /* function ptr */
118 struct close_me *next;
121 /* function prototypes for builtins */
122 static int builtin_cd(struct child_prog *cmd);
123 static int builtin_exec(struct child_prog *cmd);
124 static int builtin_exit(struct child_prog *cmd);
125 static int builtin_fg_bg(struct child_prog *cmd);
126 static int builtin_help(struct child_prog *cmd);
127 static int builtin_jobs(struct child_prog *dummy);
128 static int builtin_pwd(struct child_prog *dummy);
129 static int builtin_export(struct child_prog *cmd);
130 static int builtin_source(struct child_prog *cmd);
131 static int builtin_unset(struct child_prog *cmd);
132 static int builtin_read(struct child_prog *cmd);
135 /* function prototypes for shell stuff */
136 static void mark_open(int fd);
137 static void mark_closed(int fd);
138 static void close_all(void);
139 static void checkjobs(struct jobset *job_list);
140 static void remove_job(struct jobset *j_list, struct job *job);
141 static int get_command(FILE * source, char *command);
142 static int parse_command(char **command_ptr, struct job *job, int *inbg);
143 static int run_command(struct job *newjob, int inbg, int outpipe[2]);
144 static int pseudo_exec(struct child_prog *cmd) __attribute__ ((noreturn));
145 static int busy_loop(FILE * input);
148 /* Table of built-in functions (these are non-forking builtins, meaning they
149 * can change global variables in the parent shell process but they will not
150 * work with pipes and redirects; 'unset foo | whatever' will not work) */
151 static struct built_in_command bltins[] = {
152 {"bg", "Resume a job in the background", builtin_fg_bg},
153 {"cd", "Change working directory", builtin_cd},
154 {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
155 {"exit", "Exit from shell()", builtin_exit},
156 {"fg", "Bring job into the foreground", builtin_fg_bg},
157 {"jobs", "Lists the active jobs", builtin_jobs},
158 {"export", "Set environment variable", builtin_export},
159 {"unset", "Unset environment variable", builtin_unset},
160 {"read", "Input environment variable", builtin_read},
161 {".", "Source-in and run commands in a file", builtin_source},
162 /* to do: add ulimit */
166 /* Table of forking built-in functions (things that fork cannot change global
167 * variables in the parent process, such as the current working directory) */
168 static struct built_in_command bltins_forking[] = {
169 {"pwd", "Print current directory", builtin_pwd},
170 {"help", "List shell built-in commands", builtin_help},
175 static int shell_context; /* Type prompt trigger (PS1 or PS2) */
178 /* Globals that are static to this file */
179 static const char *cwd;
180 static char *local_pending_command = NULL;
181 static struct jobset job_list = { NULL, NULL };
184 static struct close_me *close_me_head;
185 static int last_return_code;
186 static int last_bg_pid;
187 static unsigned int last_jobid;
188 static int shell_terminal;
189 static pid_t shell_pgrp;
191 static char *PS2 = "> ";
195 static inline void debug_printf(const char *format, ...)
198 va_start(args, format);
199 vfprintf(stderr, format, args);
203 static inline void debug_printf(const char *format, ...) { }
207 Most builtins need access to the struct child_prog that has
208 their arguments, previously coded as cmd->progs[0]. That coding
209 can exhibit a bug, if the builtin is not the first command in
210 a pipeline: "echo foo | exec sort" will attempt to exec foo.
212 builtin previous use notes
213 ------ ----------------- ---------
215 exec cmd->progs[0] squashed bug: didn't look for applets or forking builtins
217 fg_bg cmd->progs[0], job_list->head, job_list->fg
226 I added "struct job *family;" to struct child_prog,
227 and switched API to builtin_foo(struct child_prog *child);
228 So cmd->text becomes child->family->text
229 cmd->job_context becomes child->family->job_context
230 cmd->progs[0] becomes *child
231 job_list becomes child->family->job_list
234 /* built-in 'cd <path>' handler */
235 static int builtin_cd(struct child_prog *child)
239 if (child->argv[1] == NULL)
240 newdir = getenv("HOME");
242 newdir = child->argv[1];
244 printf("cd: %s: %m\n", newdir);
247 cwd = xgetcwd((char *)cwd);
253 /* built-in 'exec' handler */
254 static int builtin_exec(struct child_prog *child)
256 if (child->argv[1] == NULL)
257 return EXIT_SUCCESS; /* Really? */
264 /* built-in 'exit' handler */
265 static int builtin_exit(struct child_prog *child)
267 if (child->argv[1] == NULL)
270 exit (atoi(child->argv[1]));
273 /* built-in 'fg' and 'bg' handler */
274 static int builtin_fg_bg(struct child_prog *child)
277 struct job *job=NULL;
279 /* If they gave us no args, assume they want the last backgrounded task */
280 if (!child->argv[1]) {
281 for (job = child->family->job_list->head; job; job = job->next) {
282 if (job->jobid == last_jobid) {
287 error_msg("%s: no current job", child->argv[0]);
291 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
292 error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
295 for (job = child->family->job_list->head; job; job = job->next) {
296 if (job->jobid == jobnum) {
301 error_msg("%s: %d: no such job", child->argv[0], jobnum);
306 if (*child->argv[0] == 'f') {
307 /* Put the job into the foreground. */
308 tcsetpgrp(shell_terminal, job->pgrp);
310 child->family->job_list->fg = job;
313 /* Restart the processes in the job */
314 for (i = 0; i < job->num_progs; i++)
315 job->progs[i].is_stopped = 0;
317 job->stopped_progs = 0;
319 if ( (i=kill(- job->pgrp, SIGCONT)) < 0) {
321 remove_job(&job_list, job);
323 perror_msg("kill (SIGCONT)");
330 /* built-in 'help' handler */
331 static int builtin_help(struct child_prog *dummy)
333 struct built_in_command *x;
335 printf("\nBuilt-in commands:\n");
336 printf("-------------------\n");
337 for (x = bltins; x->cmd; x++) {
340 printf("%s\t%s\n", x->cmd, x->descr);
342 for (x = bltins_forking; x->cmd; x++) {
345 printf("%s\t%s\n", x->cmd, x->descr);
351 /* built-in 'jobs' handler */
352 static int builtin_jobs(struct child_prog *child)
357 for (job = child->family->job_list->head; job; job = job->next) {
358 if (job->running_progs == job->stopped_progs)
359 status_string = "Stopped";
361 status_string = "Running";
363 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
369 /* built-in 'pwd' handler */
370 static int builtin_pwd(struct child_prog *dummy)
372 cwd = xgetcwd((char *)cwd);
379 /* built-in 'export VAR=value' handler */
380 static int builtin_export(struct child_prog *child)
383 char *v = child->argv[1];
387 for (e = environ; *e; e++) {
394 fprintf(stderr, "export: %m\n");
395 #ifdef CONFIG_FEATURE_SH_FANCY_PROMPT
396 if (strncmp(v, "PS1=", 4)==0)
400 #ifdef CONFIG_LOCALE_SUPPORT
401 if(strncmp(v, "LC_ALL=", 7)==0)
402 setlocale(LC_ALL, getenv("LC_ALL"));
403 if(strncmp(v, "LC_CTYPE=", 9)==0)
404 setlocale(LC_CTYPE, getenv("LC_CTYPE"));
410 /* built-in 'read VAR' handler */
411 static int builtin_read(struct child_prog *child)
413 int res = 0, len, newlen;
415 char string[MAX_READ];
417 if (child->argv[1]) {
418 /* argument (VAR) given: put "VAR=" into buffer */
419 safe_strncpy(string, child->argv[1], MAX_READ-1);
420 len = strlen(string);
423 fgets(&string[len], sizeof(string) - len, stdin); /* read string */
424 newlen = strlen(string);
426 string[--newlen] = '\0'; /* chomp trailing newline */
428 ** string should now contain "VAR=<value>"
429 ** copy it (putenv() won't do that, so we must make sure
430 ** the string resides in a static buffer!)
433 if((s = strdup(string)))
436 fprintf(stderr, "read: %m\n");
439 fgets(string, sizeof(string), stdin);
444 /* Built-in '.' handler (read-in and execute commands from file) */
445 static int builtin_source(struct child_prog *child)
451 if (child->argv[1] == NULL)
454 input = fopen(child->argv[1], "r");
456 printf( "Couldn't open file '%s'\n", child->argv[1]);
462 /* Now run the file */
463 status = busy_loop(input);
469 /* built-in 'unset VAR' handler */
470 static int builtin_unset(struct child_prog *child)
472 if (child->argv[1] == NULL) {
473 printf( "unset: parameter required.\n");
476 unsetenv(child->argv[1]);
480 static void mark_open(int fd)
482 struct close_me *new = xmalloc(sizeof(struct close_me));
484 new->next = close_me_head;
488 static void mark_closed(int fd)
490 struct close_me *tmp;
491 if (close_me_head == NULL || close_me_head->fd != fd)
492 error_msg_and_die("corrupt close_me");
494 close_me_head = close_me_head->next;
498 static void close_all()
500 struct close_me *c, *tmp;
501 for (c=close_me_head; c; c=tmp) {
506 close_me_head = NULL;
510 /* free up all memory from a job */
511 static void free_job(struct job *cmd)
516 for (i = 0; i < cmd->num_progs; i++) {
517 free(cmd->progs[i].argv);
518 if (cmd->progs[i].redirects)
519 free(cmd->progs[i].redirects);
527 keep = cmd->job_list;
528 memset(cmd, 0, sizeof(struct job));
529 cmd->job_list = keep;
532 /* remove a job from a jobset */
533 static void remove_job(struct jobset *j_list, struct job *job)
538 if (job == j_list->head) {
539 j_list->head = job->next;
541 prevjob = j_list->head;
542 while (prevjob->next != job)
543 prevjob = prevjob->next;
544 prevjob->next = job->next;
548 last_jobid = j_list->head->jobid;
555 /* Checks to see if any background processes have exited -- if they
556 have, figure out why and see if a job has completed */
557 static void checkjobs(struct jobset *j_list)
564 while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
565 for (job = j_list->head; job; job = job->next) {
567 while (prognum < job->num_progs &&
568 job->progs[prognum].pid != childpid) prognum++;
569 if (prognum < job->num_progs)
573 /* This happens on backticked commands */
577 if (WIFEXITED(status) || WIFSIGNALED(status)) {
579 job->running_progs--;
580 job->progs[prognum].pid = 0;
582 if (!job->running_progs) {
583 printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text);
585 remove_job(j_list, job);
589 job->stopped_progs++;
590 job->progs[prognum].is_stopped = 1;
593 /* Printing this stuff is a pain, since it tends to
594 * overwrite the prompt an inconveinient moments. So
596 if (job->stopped_progs == job->num_progs) {
597 printf(JOB_STATUS_FORMAT, job->jobid, "Stopped",
604 if (childpid == -1 && errno != ECHILD)
605 perror_msg("waitpid");
608 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
609 * and stderr if they are redirected. */
610 static int setup_redirects(struct child_prog *prog, int squirrel[])
615 struct redir_struct *redir = prog->redirects;
617 for (i = 0; i < prog->num_redirects; i++, redir++) {
618 switch (redir->type) {
622 case REDIRECT_OVERWRITE:
623 mode = O_WRONLY | O_CREAT | O_TRUNC;
625 case REDIRECT_APPEND:
626 mode = O_WRONLY | O_CREAT | O_APPEND;
630 openfd = open(redir->filename, mode, 0666);
632 /* this could get lost if stderr has been redirected, but
633 bash and ash both lose it as well (though zsh doesn't!) */
634 perror_msg("error opening %s", redir->filename);
638 if (openfd != redir->fd) {
639 if (squirrel && redir->fd < 3) {
640 squirrel[redir->fd] = dup(redir->fd);
642 dup2(openfd, redir->fd);
650 static void restore_redirects(int squirrel[])
653 for (i=0; i<3; i++) {
656 /* No error checking. I sure wouldn't know what
657 * to do with an error if I found one! */
664 static inline void cmdedit_set_initial_prompt(void)
666 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
675 static inline void setup_prompt_string(char **prompt_str)
677 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
678 /* Set up the prompt */
679 if (shell_context == 0) {
682 PS1=xmalloc(strlen(cwd)+4);
683 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
689 *prompt_str = (shell_context==0)? PS1 : PS2;
693 static int get_command(FILE * source, char *command)
697 if (source == NULL) {
698 if (local_pending_command) {
699 /* a command specified (-c option): return it & mark it done */
700 strcpy(command, local_pending_command);
701 free(local_pending_command);
702 local_pending_command = NULL;
708 if (source == stdin) {
709 setup_prompt_string(&prompt_str);
711 #ifdef CONFIG_FEATURE_COMMAND_EDITING
713 ** enable command line editing only while a command line
714 ** is actually being read; otherwise, we'll end up bequeathing
715 ** atexit() handlers and other unwanted stuff to our
716 ** child processes (rob@sysgo.de)
718 cmdedit_read_input(prompt_str, command);
721 fputs(prompt_str, stdout);
725 if (!fgets(command, BUFSIZ - 2, source)) {
734 static char* itoa(register int i)
736 static char a[7]; /* Max 7 ints */
737 register char *b = a + sizeof(a) - 1;
745 *--b = '0' + (i % 10);
754 char * strsep_space( char *string, int * ix)
760 /* Short circuit the trivial case */
761 if ( !string || ! string[*ix])
764 /* Find the end of the token. */
765 while( string && string[*ix] && !isspace(string[*ix]) ) {
769 /* Find the end of any whitespace trailing behind
770 * the token and let that be part of the token */
771 while( string && string[*ix] && isspace(string[*ix]) ) {
775 if (! string && *ix==0) {
776 /* Nothing useful was found */
780 token = xmalloc(*ix+1);
782 strncpy(token, string, *ix);
787 static int expand_arguments(char *command)
789 int total_length=0, length, i, retval, ix = 0;
790 expand_t expand_result;
791 char *tmpcmd, *cmd, *cmd_copy;
792 char *src, *dst, *var;
793 const char *out_of_space = "out of space during expansion";
794 int flags = GLOB_NOCHECK
803 /* get rid of the terminating \n */
806 /* Fix up escape sequences to be the Real Thing(tm) */
807 while( command && command[ix]) {
808 if (command[ix] == '\\') {
809 const char *tmp = command+ix+1;
810 command[ix] = process_escape_sequence( &tmp );
811 memmove(command+ix + 1, tmp, strlen(tmp)+1);
815 /* Use glob and then fixup environment variables and such */
817 /* It turns out that glob is very stupid. We have to feed it one word at a
818 * time since it can't cope with a full string. Here we convert command
819 * (char*) into cmd (char**, one word per string) */
821 /* We need a clean copy, so strsep can mess up the copy while
822 * we write stuff into the original (in a minute) */
823 cmd = cmd_copy = xstrdup(command);
825 for (ix = 0, tmpcmd = cmd;
826 (tmpcmd = strsep_space(cmd, &ix)) != NULL; cmd += ix, ix=0) {
829 /* we need to trim() the result for glob! */
831 retval = glob(tmpcmd, flags, NULL, &expand_result);
832 free(tmpcmd); /* Free mem allocated by strsep_space */
833 if (retval == GLOB_NOSPACE) {
834 /* Mem may have been allocated... */
835 globfree (&expand_result);
836 error_msg(out_of_space);
838 } else if (retval != 0) {
839 /* Some other error. GLOB_NOMATCH shouldn't
840 * happen because of the GLOB_NOCHECK flag in
842 error_msg("syntax error");
845 /* Convert from char** (one word per string) to a simple char*,
846 * but don't overflow command which is BUFSIZ in length */
847 for (i=0; i < expand_result.gl_pathc; i++) {
848 length=strlen(expand_result.gl_pathv[i]);
849 if (total_length+length+1 >= BUFSIZ) {
850 error_msg(out_of_space);
853 strcat(command+total_length, " ");
855 strcat(command+total_length, expand_result.gl_pathv[i]);
856 total_length+=length;
858 globfree (&expand_result);
864 /* Now do the shell variable substitutions which
865 * wordexp can't do for us, namely $? and $! */
867 while((dst = strchr(src,'$')) != NULL){
871 var = itoa(last_return_code);
877 var = itoa(last_bg_pid);
879 /* Everything else like $$, $#, $[0-9], etc. should all be
880 * expanded by wordexp(), so we can in theory skip that stuff
881 * here, but just to be on the safe side (i.e., since uClibc
882 * wordexp doesn't do this stuff yet), lets leave it in for
885 var = itoa(getpid());
890 case '0':case '1':case '2':case '3':case '4':
891 case '5':case '6':case '7':case '8':case '9':
893 int ixx=*(dst + 1)-48;
904 /* a single character construction was found, and
905 * already handled in the case statement */
908 /* Looks like an environment variable */
910 int num_skip_chars=0;
911 int dstlen = strlen(dst);
912 /* Is this a ${foo} type variable? */
913 if (dstlen >=2 && *(dst+1) == '{') {
914 src=strchr(dst+1, '}');
918 while(isalnum(*src) || *src=='_') src++;
924 *src='\0'; /* temporary */
925 var = getenv(dst + 1 + num_skip_chars);
927 src += num_skip_chars;
930 /* Seems we got an un-expandable variable. So delete it. */
934 int subst_len = strlen(var);
935 int trail_len = strlen(src);
936 if (dst+subst_len+trail_len >= command+BUFSIZ) {
937 error_msg(out_of_space);
940 /* Move stuff to the end of the string to accommodate
941 * filling the created gap with the new stuff */
942 memmove(dst+subst_len, src, trail_len+1);
943 /* Now copy in the new stuff */
944 memcpy(dst, var, subst_len);
952 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
953 line). If a valid command is found, command_ptr is set to point to
954 the beginning of the next command (if the original command had more
955 then one job associated with it) or NULL if no more commands are
957 static int parse_command(char **command_ptr, struct job *job, int *inbg)
960 char *return_command = NULL;
961 char *src, *buf, *chptr;
965 int i, saw_quote = 0;
968 struct child_prog *prog;
970 /* skip leading white space */
971 while (**command_ptr && isspace(**command_ptr))
974 /* this handles empty lines or leading '#' characters */
975 if (!**command_ptr || (**command_ptr == '#')) {
982 job->progs = xmalloc(sizeof(*job->progs));
984 /* We set the argv elements to point inside of this string. The
985 memory is freed by free_job(). Allocate twice the original
986 length in case we need to quote every single character.
988 Getting clean memory relieves us of the task of NULL
989 terminating things and makes the rest of this look a bit
990 cleaner (though it is, admittedly, a tad less efficient) */
991 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
995 prog->num_redirects = 0;
996 prog->redirects = NULL;
997 prog->is_stopped = 0;
1001 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1002 prog->argv[0] = job->cmdbuf;
1006 while (*src && !done) {
1007 if (quote == *src) {
1013 error_msg("character expected after \\");
1018 /* in shell, "\'" should yield \' */
1019 if (*src != quote) {
1023 } else if (*src == '*' || *src == '?' || *src == '[' ||
1024 *src == ']') *buf++ = '\\';
1026 } else if (isspace(*src)) {
1027 if (*prog->argv[argc_l] || saw_quote) {
1029 /* +1 here leaves room for the NULL which ends argv */
1030 if ((argc_l + 1) == argv_alloced) {
1032 prog->argv = xrealloc(prog->argv,
1033 sizeof(*prog->argv) *
1036 prog->argv[argc_l] = buf;
1047 case '#': /* comment */
1054 case '>': /* redirects */
1056 i = prog->num_redirects++;
1057 prog->redirects = xrealloc(prog->redirects,
1058 sizeof(*prog->redirects) *
1061 prog->redirects[i].fd = -1;
1062 if (buf != prog->argv[argc_l]) {
1063 /* the stuff before this character may be the file number
1065 prog->redirects[i].fd =
1066 strtol(prog->argv[argc_l], &chptr, 10);
1068 if (*chptr && *prog->argv[argc_l]) {
1070 prog->argv[argc_l] = buf;
1074 if (prog->redirects[i].fd == -1) {
1076 prog->redirects[i].fd = 1;
1078 prog->redirects[i].fd = 0;
1081 if (*src++ == '>') {
1083 prog->redirects[i].type =
1084 REDIRECT_APPEND, src++;
1086 prog->redirects[i].type = REDIRECT_OVERWRITE;
1088 prog->redirects[i].type = REDIRECT_INPUT;
1091 /* This isn't POSIX sh compliant. Oh well. */
1093 while (isspace(*chptr))
1097 error_msg("file name expected after %c", *(src-1));
1103 prog->redirects[i].filename = buf;
1104 while (*chptr && !isspace(*chptr))
1107 src = chptr - 1; /* we src++ later */
1108 prog->argv[argc_l] = ++buf;
1111 case '|': /* pipe */
1112 /* finish this command */
1113 if (*prog->argv[argc_l] || saw_quote)
1116 error_msg("empty command in pipe");
1121 prog->argv[argc_l] = NULL;
1123 /* and start the next */
1125 job->progs = xrealloc(job->progs,
1126 sizeof(*job->progs) * job->num_progs);
1127 prog = job->progs + (job->num_progs - 1);
1128 prog->num_redirects = 0;
1129 prog->redirects = NULL;
1130 prog->is_stopped = 0;
1135 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1136 prog->argv[0] = ++buf;
1139 while (*src && isspace(*src))
1143 error_msg("empty command in pipe");
1148 src--; /* we'll ++ it at the end of the loop */
1152 case '&': /* background */
1154 case ';': /* multiple commands */
1156 return_command = *command_ptr + (src - *command_ptr) + 1;
1162 error_msg("character expected after \\");
1166 if (*src == '*' || *src == '[' || *src == ']'
1167 || *src == '?') *buf++ = '\\';
1176 if (*prog->argv[argc_l] || saw_quote) {
1183 prog->argv[argc_l] = NULL;
1185 if (!return_command) {
1186 job->text = xmalloc(strlen(*command_ptr) + 1);
1187 strcpy(job->text, *command_ptr);
1189 /* This leaves any trailing spaces, which is a bit sloppy */
1190 count = return_command - *command_ptr;
1191 job->text = xmalloc(count + 1);
1192 strncpy(job->text, *command_ptr, count);
1193 job->text[count] = '\0';
1196 *command_ptr = return_command;
1201 /* Run the child_prog, no matter what kind of command it uses.
1203 static int pseudo_exec(struct child_prog *child)
1205 struct built_in_command *x;
1206 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1210 /* Check if the command matches any of the non-forking builtins.
1211 * Depending on context, this might be redundant. But it's
1212 * easier to waste a few CPU cycles than it is to figure out
1213 * if this is one of those cases.
1215 for (x = bltins; x->cmd; x++) {
1216 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1217 _exit(x->function(child));
1221 /* Check if the command matches any of the forking builtins. */
1222 for (x = bltins_forking; x->cmd; x++) {
1223 if (strcmp(child->argv[0], x->cmd) == 0) {
1225 _exit (x->function(child));
1228 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1229 /* Check if the command matches any busybox internal
1230 * commands ("applets") here. Following discussions from
1231 * November 2000 on busybox@busybox.net, don't use
1232 * get_last_path_component(). This way explicit (with
1233 * slashes) filenames will never be interpreted as an
1234 * applet, just like with builtins. This way the user can
1235 * override an applet with an explicit filename reference.
1236 * The only downside to this change is that an explicit
1237 * /bin/foo invocation will fork and exec /bin/foo, even if
1238 * /bin/foo is a symlink to busybox.
1240 name = child->argv[0];
1242 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1243 /* If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN, then
1244 * if you run /bin/cat, it will use BusyBox cat even if
1245 * /bin/cat exists on the filesystem and is _not_ busybox.
1246 * Some systems want this, others do not. Choose wisely. :-)
1248 name = get_last_path_component(name);
1252 char** argv_l=child->argv;
1254 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1256 run_applet_by_name(name, argc_l, child->argv);
1260 execvp(child->argv[0], child->argv);
1262 /* Do not use perror_msg_and_die() here, since we must not
1263 * call exit() but should call _exit() instead */
1264 fprintf(stderr, "%s: %m\n", child->argv[0]);
1265 _exit(EXIT_FAILURE);
1268 static void insert_job(struct job *newjob, int inbg)
1271 struct jobset *j_list=newjob->job_list;
1273 /* find the ID for thejob to use */
1275 for (thejob = j_list->head; thejob; thejob = thejob->next)
1276 if (thejob->jobid >= newjob->jobid)
1277 newjob->jobid = thejob->jobid + 1;
1279 /* add thejob to the list of running jobs */
1280 if (!j_list->head) {
1281 thejob = j_list->head = xmalloc(sizeof(*thejob));
1283 for (thejob = j_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1284 thejob->next = xmalloc(sizeof(*thejob));
1285 thejob = thejob->next;
1288 *thejob = *newjob; /* physically copy the struct job */
1289 thejob->next = NULL;
1290 thejob->running_progs = thejob->num_progs;
1291 thejob->stopped_progs = 0;
1294 /* we don't wait for background thejobs to return -- append it
1295 to the list of backgrounded thejobs and leave it alone */
1296 printf("[%d] %d\n", thejob->jobid,
1297 newjob->progs[newjob->num_progs - 1].pid);
1298 last_jobid = newjob->jobid;
1299 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1301 newjob->job_list->fg = thejob;
1303 /* move the new process group into the foreground */
1304 /* suppress messages when run from /linuxrc mag@sysgo.de */
1305 if (tcsetpgrp(shell_terminal, newjob->pgrp) && errno != ENOTTY)
1306 perror_msg("tcsetpgrp");
1310 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1312 /* struct job *thejob; */
1314 int nextin, nextout;
1315 int pipefds[2]; /* pipefd[0] is for reading */
1316 struct built_in_command *x;
1317 struct child_prog *child;
1319 nextin = 0, nextout = 1;
1320 for (i = 0; i < newjob->num_progs; i++) {
1321 child = & (newjob->progs[i]);
1323 if ((i + 1) < newjob->num_progs) {
1324 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1325 nextout = pipefds[1];
1327 if (outpipe[1]!=-1) {
1328 nextout = outpipe[1];
1335 /* Check if the command matches any non-forking builtins,
1336 * but only if this is a simple command.
1337 * Non-forking builtins within pipes have to fork anyway,
1338 * and are handled in pseudo_exec. "echo foo | read bar"
1339 * is doomed to failure, and doesn't work on bash, either.
1341 if (newjob->num_progs == 1) {
1342 for (x = bltins; x->cmd; x++) {
1343 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1344 int squirrel[] = {-1, -1, -1};
1346 setup_redirects(child, squirrel);
1347 rcode = x->function(child);
1348 restore_redirects(squirrel);
1354 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
1355 if (!(child->pid = fork()))
1357 if (!(child->pid = vfork()))
1360 /* Set the handling for job control signals back to the default. */
1361 signal(SIGINT, SIG_DFL);
1362 signal(SIGQUIT, SIG_DFL);
1363 signal(SIGTSTP, SIG_DFL);
1364 signal(SIGTTIN, SIG_DFL);
1365 signal(SIGTTOU, SIG_DFL);
1366 signal(SIGCHLD, SIG_DFL);
1370 if (outpipe[1]!=-1) {
1380 dup2(nextout, 2); /* Really? */
1385 /* explicit redirects override pipes */
1386 setup_redirects(child,NULL);
1390 if (outpipe[1]!=-1) {
1394 /* put our child in the process group whose leader is the
1395 first process in this pipe */
1396 setpgid(child->pid, newjob->progs[0].pid);
1402 /* If there isn't another process, nextin is garbage
1403 but it doesn't matter */
1404 nextin = pipefds[0];
1407 newjob->pgrp = newjob->progs[0].pid;
1409 insert_job(newjob, inbg);
1414 static int busy_loop(FILE * input)
1417 char *next_command = NULL;
1423 newjob.job_list = &job_list;
1424 newjob.job_context = DEFAULT_CONTEXT;
1426 /* save current owner of TTY so we can restore it on exit */
1427 parent_pgrp = tcgetpgrp(shell_terminal);
1429 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1433 /* no job is in the foreground */
1435 /* see if any background processes have exited */
1436 checkjobs(&job_list);
1438 if (!next_command) {
1439 if (get_command(input, command))
1441 next_command = command;
1444 if (! expand_arguments(next_command)) {
1446 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1447 next_command = NULL;
1451 if (!parse_command(&next_command, &newjob, &inbg) &&
1453 int pipefds[2] = {-1,-1};
1454 debug_printf( "job=%p fed to run_command by busy_loop()'\n",
1456 run_command(&newjob, inbg, pipefds);
1460 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1461 next_command = NULL;
1464 /* a job is running in the foreground; wait for it */
1466 while (!job_list.fg->progs[i].pid ||
1467 job_list.fg->progs[i].is_stopped == 1) i++;
1469 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0) {
1470 if (errno != ECHILD) {
1471 perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1475 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1476 /* the child exited */
1477 job_list.fg->running_progs--;
1478 job_list.fg->progs[i].pid = 0;
1480 last_return_code=WEXITSTATUS(status);
1482 if (!job_list.fg->running_progs) {
1484 remove_job(&job_list, job_list.fg);
1488 /* the child was stopped */
1489 job_list.fg->stopped_progs++;
1490 job_list.fg->progs[i].is_stopped = 1;
1492 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1493 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1494 "Stopped", job_list.fg->text);
1500 /* move the shell to the foreground */
1501 /* suppress messages when run from /linuxrc mag@sysgo.de */
1502 if (tcsetpgrp(shell_terminal, getpgrp()) && errno != ENOTTY)
1503 perror_msg("tcsetpgrp");
1509 /* return controlling TTY back to parent process group before exiting */
1510 if (tcsetpgrp(shell_terminal, parent_pgrp) && errno != ENOTTY)
1511 perror_msg("tcsetpgrp");
1513 /* return exit status if called with "-c" */
1514 if (input == NULL && WIFEXITED(status))
1515 return WEXITSTATUS(status);
1521 #ifdef CONFIG_FEATURE_CLEAN_UP
1522 void free_memory(void)
1524 if (cwd && cwd!=unknown) {
1527 if (local_pending_command)
1528 free(local_pending_command);
1530 if (job_list.fg && !job_list.fg->running_progs) {
1531 remove_job(&job_list, job_list.fg);
1536 /* Make sure we have a controlling tty. If we get started under a job
1537 * aware app (like bash for example), make sure we are now in charge so
1538 * we don't fight over who gets the foreground */
1539 static void setup_job_control()
1543 /* Loop until we are in the foreground. */
1544 while ((status = tcgetpgrp (shell_terminal)) >= 0) {
1545 if (status == (shell_pgrp = getpgrp ())) {
1548 kill (- shell_pgrp, SIGTTIN);
1551 /* Ignore interactive and job-control signals. */
1552 signal(SIGINT, SIG_IGN);
1553 signal(SIGQUIT, SIG_IGN);
1554 signal(SIGTSTP, SIG_IGN);
1555 signal(SIGTTIN, SIG_IGN);
1556 signal(SIGTTOU, SIG_IGN);
1557 signal(SIGCHLD, SIG_IGN);
1559 /* Put ourselves in our own process group. */
1561 shell_pgrp = getpid ();
1562 setpgid (shell_pgrp, shell_pgrp);
1564 /* Grab control of the terminal. */
1565 tcsetpgrp(shell_terminal, shell_pgrp);
1568 int lash_main(int argc_l, char **argv_l)
1570 int opt, interactive=FALSE;
1571 FILE *input = stdin;
1575 /* These variables need re-initializing when recursing */
1577 local_pending_command = NULL;
1578 close_me_head = NULL;
1579 job_list.head = NULL;
1583 if (argv[0] && argv[0][0] == '-') {
1585 prof_input = fopen("/etc/profile", "r");
1587 int tmp_fd = fileno(prof_input);
1589 /* Now run the file */
1590 busy_loop(prof_input);
1592 mark_closed(tmp_fd);
1596 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1600 if (local_pending_command != 0)
1601 error_msg_and_die("multiple -c arguments");
1602 local_pending_command = xstrdup(argv[optind]);
1613 /* A shell is interactive if the `-i' flag was given, or if all of
1614 * the following conditions are met:
1616 * no arguments remaining or the -s flag given
1617 * standard input is a terminal
1618 * standard output is a terminal
1619 * Refer to Posix.2, the description of the `sh' utility. */
1620 if (argv[optind]==NULL && input==stdin &&
1621 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
1624 setup_job_control();
1625 if (interactive==TRUE) {
1626 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1627 /* Looks like they want an interactive shell */
1628 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
1629 printf( "\n\n" BB_BANNER " Built-in shell (lash)\n");
1630 printf( "Enter 'help' for a list of built-in commands.\n\n");
1632 } else if (local_pending_command==NULL) {
1633 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1634 input = xfopen(argv[optind], "r");
1635 mark_open(fileno(input)); /* be lazy, never mark this closed */
1638 /* initialize the cwd -- this is never freed...*/
1643 #ifdef CONFIG_FEATURE_CLEAN_UP
1644 atexit(free_memory);
1647 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1648 cmdedit_set_initial_prompt();
1653 return (busy_loop(input));