1 /* vi: set sw=4 ts=4: */
3 * lash -- the BusyBox Lame-Ass SHell
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 * Based in part on ladsh.c by Michael K. Johnson and Erik W. Troan, which is
8 * under the following liberal license: "We have placed this source code in the
9 * public domain. Use it in any project, free or commercial."
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 /* This shell's parsing engine is officially at a dead-end. Future
28 * work shell work should be done using hush, msh, or ash. This is
29 * still a very useful, small shell -- it just don't need any more
30 * features beyond what it already has...
33 //For debugging/development on the shell only...
44 #include <sys/ioctl.h>
52 #ifdef CONFIG_LOCALE_SUPPORT
57 #define expand_t glob_t
59 /* Always enable for the moment... */
60 #define CONFIG_LASH_PIPE_N_REDIRECTS
61 #define CONFIG_LASH_JOB_CONTROL
63 static const int MAX_READ = 128; /* size of input buffer for `read' builtin */
64 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
67 #ifdef CONFIG_LASH_PIPE_N_REDIRECTS
68 enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
73 static const unsigned int DEFAULT_CONTEXT=0x1;
74 static const unsigned int IF_TRUE_CONTEXT=0x2;
75 static const unsigned int IF_FALSE_CONTEXT=0x4;
76 static const unsigned int THEN_EXP_CONTEXT=0x8;
77 static const unsigned int ELSE_EXP_CONTEXT=0x10;
79 #ifdef CONFIG_LASH_PIPE_N_REDIRECTS
81 enum redir_type type; /* type of redirection */
82 int fd; /* file descriptor being redirected */
83 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 int is_stopped; /* is the program currently running? */
92 struct job *family; /* pointer back to the child's parent job */
93 #ifdef CONFIG_LASH_PIPE_N_REDIRECTS
94 struct redir_struct *redirects; /* I/O redirects */
99 struct job *head; /* head of list of running jobs */
100 struct job *fg; /* current foreground job */
104 int jobid; /* job number */
105 int num_progs; /* total number of programs in job */
106 int running_progs; /* number of programs running */
107 char *text; /* name of job */
108 char *cmdbuf; /* buffer various argv's point into */
109 pid_t pgrp; /* process group ID for the job */
110 struct child_prog *progs; /* array of programs in job */
111 struct job *next; /* to track background commands */
112 int stopped_progs; /* number of programs alive, but stopped */
113 unsigned int job_context; /* bitmask defining current context */
114 struct jobset *job_list;
117 struct built_in_command {
118 char *cmd; /* name */
119 char *descr; /* description */
120 int (*function) (struct child_prog *); /* function ptr */
125 struct close_me *next;
128 /* function prototypes for builtins */
129 static int builtin_cd(struct child_prog *cmd);
130 static int builtin_exec(struct child_prog *cmd);
131 static int builtin_exit(struct child_prog *cmd);
132 static int builtin_fg_bg(struct child_prog *cmd);
133 static int builtin_help(struct child_prog *cmd);
134 static int builtin_jobs(struct child_prog *dummy);
135 static int builtin_pwd(struct child_prog *dummy);
136 static int builtin_export(struct child_prog *cmd);
137 static int builtin_source(struct child_prog *cmd);
138 static int builtin_unset(struct child_prog *cmd);
139 static int builtin_read(struct child_prog *cmd);
142 /* function prototypes for shell stuff */
143 static void mark_open(int fd);
144 static void mark_closed(int fd);
145 static void close_all(void);
146 static void checkjobs(struct jobset *job_list);
147 static void remove_job(struct jobset *j_list, struct job *job);
148 static int get_command(FILE * source, char *command);
149 static int parse_command(char **command_ptr, struct job *job, int *inbg);
150 static int run_command(struct job *newjob, int inbg, int outpipe[2]);
151 static int pseudo_exec(struct child_prog *cmd) __attribute__ ((noreturn));
152 static int busy_loop(FILE * input);
155 /* Table of built-in functions (these are non-forking builtins, meaning they
156 * can change global variables in the parent shell process but they will not
157 * work with pipes and redirects; 'unset foo | whatever' will not work) */
158 static struct built_in_command bltins[] = {
159 {"bg", "Resume a job in the background", builtin_fg_bg},
160 {"cd", "Change working directory", builtin_cd},
161 {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
162 {"exit", "Exit from shell()", builtin_exit},
163 {"fg", "Bring job into the foreground", builtin_fg_bg},
164 {"jobs", "Lists the active jobs", builtin_jobs},
165 {"export", "Set environment variable", builtin_export},
166 {"unset", "Unset environment variable", builtin_unset},
167 {"read", "Input environment variable", builtin_read},
168 {".", "Source-in and run commands in a file", builtin_source},
169 /* to do: add ulimit */
173 /* Table of forking built-in functions (things that fork cannot change global
174 * variables in the parent process, such as the current working directory) */
175 static struct built_in_command bltins_forking[] = {
176 {"pwd", "Print current directory", builtin_pwd},
177 {"help", "List shell built-in commands", builtin_help},
182 static int shell_context; /* Type prompt trigger (PS1 or PS2) */
185 /* Globals that are static to this file */
186 static const char *cwd;
187 static char *local_pending_command = NULL;
188 static struct jobset job_list = { NULL, NULL };
191 static struct close_me *close_me_head;
192 static int last_return_code;
193 static int last_bg_pid;
194 static unsigned int last_jobid;
195 static int shell_terminal;
197 static char *PS2 = "> ";
201 static inline void debug_printf(const char *format, ...)
204 va_start(args, format);
205 vfprintf(stderr, format, args);
209 static inline void debug_printf(const char *format, ...) { }
213 Most builtins need access to the struct child_prog that has
214 their arguments, previously coded as cmd->progs[0]. That coding
215 can exhibit a bug, if the builtin is not the first command in
216 a pipeline: "echo foo | exec sort" will attempt to exec foo.
218 builtin previous use notes
219 ------ ----------------- ---------
221 exec cmd->progs[0] squashed bug: didn't look for applets or forking builtins
223 fg_bg cmd->progs[0], job_list->head, job_list->fg
232 I added "struct job *family;" to struct child_prog,
233 and switched API to builtin_foo(struct child_prog *child);
234 So cmd->text becomes child->family->text
235 cmd->job_context becomes child->family->job_context
236 cmd->progs[0] becomes *child
237 job_list becomes child->family->job_list
240 /* built-in 'cd <path>' handler */
241 static int builtin_cd(struct child_prog *child)
245 if (child->argv[1] == NULL)
246 newdir = getenv("HOME");
248 newdir = child->argv[1];
250 printf("cd: %s: %m\n", newdir);
253 cwd = xgetcwd((char *)cwd);
255 cwd = bb_msg_unknown;
259 /* built-in 'exec' handler */
260 static int builtin_exec(struct child_prog *child)
262 if (child->argv[1] == NULL)
263 return EXIT_SUCCESS; /* Really? */
270 /* built-in 'exit' handler */
271 static int builtin_exit(struct child_prog *child)
273 if (child->argv[1] == NULL)
276 exit (atoi(child->argv[1]));
279 /* built-in 'fg' and 'bg' handler */
280 static int builtin_fg_bg(struct child_prog *child)
283 struct job *job=NULL;
285 /* If they gave us no args, assume they want the last backgrounded task */
286 if (!child->argv[1]) {
287 for (job = child->family->job_list->head; job; job = job->next) {
288 if (job->jobid == last_jobid) {
293 bb_error_msg("%s: no current job", child->argv[0]);
297 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
298 bb_error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
301 for (job = child->family->job_list->head; job; job = job->next) {
302 if (job->jobid == jobnum) {
307 bb_error_msg("%s: %d: no such job", child->argv[0], jobnum);
312 if (*child->argv[0] == 'f') {
313 /* Put the job into the foreground. */
314 tcsetpgrp(shell_terminal, job->pgrp);
316 child->family->job_list->fg = job;
319 /* Restart the processes in the job */
320 for (i = 0; i < job->num_progs; i++)
321 job->progs[i].is_stopped = 0;
323 job->stopped_progs = 0;
325 if ( (i=kill(- job->pgrp, SIGCONT)) < 0) {
327 remove_job(&job_list, job);
329 bb_perror_msg("kill (SIGCONT)");
336 /* built-in 'help' handler */
337 static int builtin_help(struct child_prog *dummy)
339 struct built_in_command *x;
341 printf("\nBuilt-in commands:\n");
342 printf("-------------------\n");
343 for (x = bltins; x->cmd; x++) {
346 printf("%s\t%s\n", x->cmd, x->descr);
348 for (x = bltins_forking; x->cmd; x++) {
351 printf("%s\t%s\n", x->cmd, x->descr);
357 /* built-in 'jobs' handler */
358 static int builtin_jobs(struct child_prog *child)
363 for (job = child->family->job_list->head; job; job = job->next) {
364 if (job->running_progs == job->stopped_progs)
365 status_string = "Stopped";
367 status_string = "Running";
369 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
375 /* built-in 'pwd' handler */
376 static int builtin_pwd(struct child_prog *dummy)
378 cwd = xgetcwd((char *)cwd);
380 cwd = bb_msg_unknown;
385 /* built-in 'export VAR=value' handler */
386 static int builtin_export(struct child_prog *child)
389 char *v = child->argv[1];
393 for (e = environ; *e; e++) {
400 fprintf(stderr, "export: %m\n");
401 #ifdef CONFIG_FEATURE_SH_FANCY_PROMPT
402 if (strncmp(v, "PS1=", 4)==0)
406 #ifdef CONFIG_LOCALE_SUPPORT
407 if(strncmp(v, "LC_ALL=", 7)==0)
408 setlocale(LC_ALL, getenv("LC_ALL"));
409 if(strncmp(v, "LC_CTYPE=", 9)==0)
410 setlocale(LC_CTYPE, getenv("LC_CTYPE"));
416 /* built-in 'read VAR' handler */
417 static int builtin_read(struct child_prog *child)
419 int res = 0, len, newlen;
421 char string[MAX_READ];
423 if (child->argv[1]) {
424 /* argument (VAR) given: put "VAR=" into buffer */
425 safe_strncpy(string, child->argv[1], MAX_READ-1);
426 len = strlen(string);
429 fgets(&string[len], sizeof(string) - len, stdin); /* read string */
430 newlen = strlen(string);
432 string[--newlen] = '\0'; /* chomp trailing newline */
434 ** string should now contain "VAR=<value>"
435 ** copy it (putenv() won't do that, so we must make sure
436 ** the string resides in a static buffer!)
439 if((s = strdup(string)))
442 fprintf(stderr, "read: %m\n");
445 fgets(string, sizeof(string), stdin);
450 /* Built-in '.' handler (read-in and execute commands from file) */
451 static int builtin_source(struct child_prog *child)
457 if (child->argv[1] == NULL)
460 input = fopen(child->argv[1], "r");
462 printf( "Couldn't open file '%s'\n", child->argv[1]);
468 /* Now run the file */
469 status = busy_loop(input);
475 /* built-in 'unset VAR' handler */
476 static int builtin_unset(struct child_prog *child)
478 if (child->argv[1] == NULL) {
479 printf( "unset: parameter required.\n");
482 unsetenv(child->argv[1]);
486 static void mark_open(int fd)
488 struct close_me *new = xmalloc(sizeof(struct close_me));
490 new->next = close_me_head;
494 static void mark_closed(int fd)
496 struct close_me *tmp;
497 if (close_me_head == NULL || close_me_head->fd != fd)
498 bb_error_msg_and_die("corrupt close_me");
500 close_me_head = close_me_head->next;
504 static void close_all()
506 struct close_me *c, *tmp;
507 for (c=close_me_head; c; c=tmp) {
512 close_me_head = NULL;
516 #ifdef CONFIG_LASH_JOB_CONTROL
517 /* free up all memory from a job */
518 static void free_job(struct job *cmd)
523 for (i = 0; i < cmd->num_progs; i++) {
524 free(cmd->progs[i].argv);
525 #ifdef CONFIG_LASH_PIPE_N_REDIRECTS
526 if (cmd->progs[i].redirects)
527 free(cmd->progs[i].redirects);
533 keep = cmd->job_list;
534 memset(cmd, 0, sizeof(struct job));
535 cmd->job_list = keep;
538 /* remove a job from a jobset */
539 static void remove_job(struct jobset *j_list, struct job *job)
544 if (job == j_list->head) {
545 j_list->head = job->next;
547 prevjob = j_list->head;
548 while (prevjob->next != job)
549 prevjob = prevjob->next;
550 prevjob->next = job->next;
554 last_jobid = j_list->head->jobid;
561 /* Checks to see if any background processes have exited -- if they
562 have, figure out why and see if a job has completed */
563 static void checkjobs(struct jobset *j_list)
570 while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
571 for (job = j_list->head; job; job = job->next) {
573 while (prognum < job->num_progs &&
574 job->progs[prognum].pid != childpid) prognum++;
575 if (prognum < job->num_progs)
579 /* This happens on backticked commands */
583 if (WIFEXITED(status) || WIFSIGNALED(status)) {
585 job->running_progs--;
586 job->progs[prognum].pid = 0;
588 if (!job->running_progs) {
589 printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text);
591 remove_job(j_list, job);
595 job->stopped_progs++;
596 job->progs[prognum].is_stopped = 1;
599 /* Printing this stuff is a pain, since it tends to
600 * overwrite the prompt an inconveinient moments. So
602 if (job->stopped_progs == job->num_progs) {
603 printf(JOB_STATUS_FORMAT, job->jobid, "Stopped",
610 if (childpid == -1 && errno != ECHILD)
611 bb_perror_msg("waitpid");
614 static void checkjobs(struct jobset *j_list)
617 static void free_job(struct job *cmd)
620 static void remove_job(struct jobset *j_list, struct job *job)
625 #ifdef CONFIG_LASH_PIPE_N_REDIRECTS
626 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
627 * and stderr if they are redirected. */
628 static int setup_redirects(struct child_prog *prog, int squirrel[])
633 struct redir_struct *redir = prog->redirects;
635 for (i = 0; i < prog->num_redirects; i++, redir++) {
636 switch (redir->type) {
640 case REDIRECT_OVERWRITE:
641 mode = O_WRONLY | O_CREAT | O_TRUNC;
643 case REDIRECT_APPEND:
644 mode = O_WRONLY | O_CREAT | O_APPEND;
648 openfd = open(redir->filename, mode, 0666);
650 /* this could get lost if stderr has been redirected, but
651 bash and ash both lose it as well (though zsh doesn't!) */
652 bb_perror_msg("error opening %s", redir->filename);
656 if (openfd != redir->fd) {
657 if (squirrel && redir->fd < 3) {
658 squirrel[redir->fd] = dup(redir->fd);
659 fcntl (squirrel[redir->fd], F_SETFD, FD_CLOEXEC);
661 dup2(openfd, redir->fd);
669 static void restore_redirects(int squirrel[])
672 for (i=0; i<3; i++) {
675 /* No error checking. I sure wouldn't know what
676 * to do with an error if I found one! */
683 static inline int setup_redirects(struct child_prog *prog, int squirrel[])
687 static inline void restore_redirects(int squirrel[])
692 static inline void cmdedit_set_initial_prompt(void)
694 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
703 static inline void setup_prompt_string(char **prompt_str)
705 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
706 /* Set up the prompt */
707 if (shell_context == 0) {
709 PS1=xmalloc(strlen(cwd)+4);
710 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
716 *prompt_str = (shell_context==0)? PS1 : PS2;
720 static int get_command(FILE * source, char *command)
724 if (source == NULL) {
725 if (local_pending_command) {
726 /* a command specified (-c option): return it & mark it done */
727 strcpy(command, local_pending_command);
728 free(local_pending_command);
729 local_pending_command = NULL;
735 if (source == stdin) {
736 setup_prompt_string(&prompt_str);
738 #ifdef CONFIG_FEATURE_COMMAND_EDITING
740 ** enable command line editing only while a command line
741 ** is actually being read; otherwise, we'll end up bequeathing
742 ** atexit() handlers and other unwanted stuff to our
743 ** child processes (rob@sysgo.de)
745 cmdedit_read_input(prompt_str, command);
748 fputs(prompt_str, stdout);
752 if (!fgets(command, BUFSIZ - 2, source)) {
761 static char* itoa(register int i)
763 static char a[7]; /* Max 7 ints */
764 register char *b = a + sizeof(a) - 1;
772 *--b = '0' + (i % 10);
781 char * strsep_space( char *string, int * ix)
787 /* Short circuit the trivial case */
788 if ( !string || ! string[*ix])
791 /* Find the end of the token. */
792 while( string && string[*ix] && !isspace(string[*ix]) ) {
796 /* Find the end of any whitespace trailing behind
797 * the token and let that be part of the token */
798 while( string && string[*ix] && isspace(string[*ix]) ) {
802 if (! string && *ix==0) {
803 /* Nothing useful was found */
807 token = xmalloc(*ix+1);
809 strncpy(token, string, *ix);
814 static int expand_arguments(char *command)
816 int total_length=0, length, i, retval, ix = 0;
817 expand_t expand_result;
818 char *tmpcmd, *cmd, *cmd_copy;
819 char *src, *dst, *var;
820 const char *out_of_space = "out of space during expansion";
821 int flags = GLOB_NOCHECK
830 /* get rid of the terminating \n */
833 /* Fix up escape sequences to be the Real Thing(tm) */
834 while( command && command[ix]) {
835 if (command[ix] == '\\') {
836 const char *tmp = command+ix+1;
837 command[ix] = bb_process_escape_sequence( &tmp );
838 memmove(command+ix + 1, tmp, strlen(tmp)+1);
842 /* Use glob and then fixup environment variables and such */
844 /* It turns out that glob is very stupid. We have to feed it one word at a
845 * time since it can't cope with a full string. Here we convert command
846 * (char*) into cmd (char**, one word per string) */
848 /* We need a clean copy, so strsep can mess up the copy while
849 * we write stuff into the original (in a minute) */
850 cmd = cmd_copy = bb_xstrdup(command);
852 for (ix = 0, tmpcmd = cmd;
853 (tmpcmd = strsep_space(cmd, &ix)) != NULL; cmd += ix, ix=0) {
856 /* we need to trim() the result for glob! */
858 retval = glob(tmpcmd, flags, NULL, &expand_result);
859 free(tmpcmd); /* Free mem allocated by strsep_space */
860 if (retval == GLOB_NOSPACE) {
861 /* Mem may have been allocated... */
862 globfree (&expand_result);
863 bb_error_msg(out_of_space);
865 } else if (retval != 0) {
866 /* Some other error. GLOB_NOMATCH shouldn't
867 * happen because of the GLOB_NOCHECK flag in
869 bb_error_msg("syntax error");
872 /* Convert from char** (one word per string) to a simple char*,
873 * but don't overflow command which is BUFSIZ in length */
874 for (i=0; i < expand_result.gl_pathc; i++) {
875 length=strlen(expand_result.gl_pathv[i]);
876 if (total_length+length+1 >= BUFSIZ) {
877 bb_error_msg(out_of_space);
880 strcat(command+total_length, " ");
882 strcat(command+total_length, expand_result.gl_pathv[i]);
883 total_length+=length;
885 globfree (&expand_result);
891 /* Now do the shell variable substitutions which
892 * wordexp can't do for us, namely $? and $! */
894 while((dst = strchr(src,'$')) != NULL){
898 var = itoa(last_return_code);
904 var = itoa(last_bg_pid);
906 /* Everything else like $$, $#, $[0-9], etc. should all be
907 * expanded by wordexp(), so we can in theory skip that stuff
908 * here, but just to be on the safe side (i.e., since uClibc
909 * wordexp doesn't do this stuff yet), lets leave it in for
912 var = itoa(getpid());
917 case '0':case '1':case '2':case '3':case '4':
918 case '5':case '6':case '7':case '8':case '9':
920 int ixx=*(dst+1)-48+1;
931 /* a single character construction was found, and
932 * already handled in the case statement */
935 /* Looks like an environment variable */
937 int num_skip_chars=0;
938 int dstlen = strlen(dst);
939 /* Is this a ${foo} type variable? */
940 if (dstlen >=2 && *(dst+1) == '{') {
941 src=strchr(dst+1, '}');
945 while(isalnum(*src) || *src=='_') src++;
951 *src='\0'; /* temporary */
952 var = getenv(dst + 1 + num_skip_chars);
954 src += num_skip_chars;
957 /* Seems we got an un-expandable variable. So delete it. */
961 int subst_len = strlen(var);
962 int trail_len = strlen(src);
963 if (dst+subst_len+trail_len >= command+BUFSIZ) {
964 bb_error_msg(out_of_space);
967 /* Move stuff to the end of the string to accommodate
968 * filling the created gap with the new stuff */
969 memmove(dst+subst_len, src, trail_len+1);
970 /* Now copy in the new stuff */
971 memcpy(dst, var, subst_len);
979 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
980 line). If a valid command is found, command_ptr is set to point to
981 the beginning of the next command (if the original command had more
982 then one job associated with it) or NULL if no more commands are
984 static int parse_command(char **command_ptr, struct job *job, int *inbg)
987 char *return_command = NULL;
995 struct child_prog *prog;
996 #ifdef CONFIG_LASH_PIPE_N_REDIRECTS
1001 /* skip leading white space */
1002 while (**command_ptr && isspace(**command_ptr))
1005 /* this handles empty lines or leading '#' characters */
1006 if (!**command_ptr || (**command_ptr == '#')) {
1013 job->progs = xmalloc(sizeof(*job->progs));
1015 /* We set the argv elements to point inside of this string. The
1016 memory is freed by free_job(). Allocate twice the original
1017 length in case we need to quote every single character.
1019 Getting clean memory relieves us of the task of NULL
1020 terminating things and makes the rest of this look a bit
1021 cleaner (though it is, admittedly, a tad less efficient) */
1022 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
1026 prog->num_redirects = 0;
1027 prog->is_stopped = 0;
1029 #ifdef CONFIG_LASH_PIPE_N_REDIRECTS
1030 prog->redirects = NULL;
1034 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1035 prog->argv[0] = job->cmdbuf;
1039 while (*src && !done) {
1040 if (quote == *src) {
1046 bb_error_msg("character expected after \\");
1051 /* in shell, "\'" should yield \' */
1052 if (*src != quote) {
1056 } else if (*src == '*' || *src == '?' || *src == '[' ||
1057 *src == ']') *buf++ = '\\';
1059 } else if (isspace(*src)) {
1060 if (*prog->argv[argc_l] || saw_quote) {
1062 /* +1 here leaves room for the NULL which ends argv */
1063 if ((argc_l + 1) == argv_alloced) {
1065 prog->argv = xrealloc(prog->argv,
1066 sizeof(*prog->argv) *
1069 prog->argv[argc_l] = buf;
1080 case '#': /* comment */
1087 #ifdef CONFIG_LASH_PIPE_N_REDIRECTS
1088 case '>': /* redirects */
1090 i = prog->num_redirects++;
1091 prog->redirects = xrealloc(prog->redirects,
1092 sizeof(*prog->redirects) *
1095 prog->redirects[i].fd = -1;
1096 if (buf != prog->argv[argc_l]) {
1097 /* the stuff before this character may be the file number
1099 prog->redirects[i].fd =
1100 strtol(prog->argv[argc_l], &chptr, 10);
1102 if (*chptr && *prog->argv[argc_l]) {
1104 prog->argv[argc_l] = buf;
1108 if (prog->redirects[i].fd == -1) {
1110 prog->redirects[i].fd = 1;
1112 prog->redirects[i].fd = 0;
1115 if (*src++ == '>') {
1117 prog->redirects[i].type =
1118 REDIRECT_APPEND, src++;
1120 prog->redirects[i].type = REDIRECT_OVERWRITE;
1122 prog->redirects[i].type = REDIRECT_INPUT;
1125 /* This isn't POSIX sh compliant. Oh well. */
1127 while (isspace(*chptr))
1131 bb_error_msg("file name expected after %c", *(src-1));
1137 prog->redirects[i].filename = buf;
1138 while (*chptr && !isspace(*chptr))
1141 src = chptr - 1; /* we src++ later */
1142 prog->argv[argc_l] = ++buf;
1145 case '|': /* pipe */
1146 /* finish this command */
1147 if (*prog->argv[argc_l] || saw_quote)
1150 bb_error_msg("empty command in pipe");
1155 prog->argv[argc_l] = NULL;
1157 /* and start the next */
1159 job->progs = xrealloc(job->progs,
1160 sizeof(*job->progs) * job->num_progs);
1161 prog = job->progs + (job->num_progs - 1);
1162 prog->num_redirects = 0;
1163 prog->redirects = NULL;
1164 prog->is_stopped = 0;
1169 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1170 prog->argv[0] = ++buf;
1173 while (*src && isspace(*src))
1177 bb_error_msg("empty command in pipe");
1182 src--; /* we'll ++ it at the end of the loop */
1187 #ifdef CONFIG_LASH_JOB_CONTROL
1188 case '&': /* background */
1191 case ';': /* multiple commands */
1193 return_command = *command_ptr + (src - *command_ptr) + 1;
1199 bb_error_msg("character expected after \\");
1203 if (*src == '*' || *src == '[' || *src == ']'
1204 || *src == '?') *buf++ = '\\';
1213 if (*prog->argv[argc_l] || saw_quote) {
1220 prog->argv[argc_l] = NULL;
1222 if (!return_command) {
1223 job->text = xmalloc(strlen(*command_ptr) + 1);
1224 strcpy(job->text, *command_ptr);
1226 /* This leaves any trailing spaces, which is a bit sloppy */
1227 count = return_command - *command_ptr;
1228 job->text = xmalloc(count + 1);
1229 strncpy(job->text, *command_ptr, count);
1230 job->text[count] = '\0';
1233 *command_ptr = return_command;
1238 /* Run the child_prog, no matter what kind of command it uses.
1240 static int pseudo_exec(struct child_prog *child)
1242 struct built_in_command *x;
1243 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1247 /* Check if the command matches any of the non-forking builtins.
1248 * Depending on context, this might be redundant. But it's
1249 * easier to waste a few CPU cycles than it is to figure out
1250 * if this is one of those cases.
1252 for (x = bltins; x->cmd; x++) {
1253 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1254 _exit(x->function(child));
1258 /* Check if the command matches any of the forking builtins. */
1259 for (x = bltins_forking; x->cmd; x++) {
1260 if (strcmp(child->argv[0], x->cmd) == 0) {
1261 bb_applet_name=x->cmd;
1262 _exit (x->function(child));
1265 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1266 /* Check if the command matches any busybox internal
1267 * commands ("applets") here. Following discussions from
1268 * November 2000 on busybox@busybox.net, don't use
1269 * bb_get_last_path_component(). This way explicit (with
1270 * slashes) filenames will never be interpreted as an
1271 * applet, just like with builtins. This way the user can
1272 * override an applet with an explicit filename reference.
1273 * The only downside to this change is that an explicit
1274 * /bin/foo invocation will fork and exec /bin/foo, even if
1275 * /bin/foo is a symlink to busybox.
1277 name = child->argv[0];
1280 char** argv_l=child->argv;
1282 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1284 run_applet_by_name(name, argc_l, child->argv);
1288 execvp(child->argv[0], child->argv);
1290 /* Do not use bb_perror_msg_and_die() here, since we must not
1291 * call exit() but should call _exit() instead */
1292 fprintf(stderr, "%s: %m\n", child->argv[0]);
1293 _exit(EXIT_FAILURE);
1296 static void insert_job(struct job *newjob, int inbg)
1299 struct jobset *j_list=newjob->job_list;
1301 /* find the ID for thejob to use */
1303 for (thejob = j_list->head; thejob; thejob = thejob->next)
1304 if (thejob->jobid >= newjob->jobid)
1305 newjob->jobid = thejob->jobid + 1;
1307 /* add thejob to the list of running jobs */
1308 if (!j_list->head) {
1309 thejob = j_list->head = xmalloc(sizeof(*thejob));
1311 for (thejob = j_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1312 thejob->next = xmalloc(sizeof(*thejob));
1313 thejob = thejob->next;
1316 *thejob = *newjob; /* physically copy the struct job */
1317 thejob->next = NULL;
1318 thejob->running_progs = thejob->num_progs;
1319 thejob->stopped_progs = 0;
1321 #ifdef CONFIG_LASH_JOB_CONTROL
1323 /* we don't wait for background thejobs to return -- append it
1324 to the list of backgrounded thejobs and leave it alone */
1325 printf("[%d] %d\n", thejob->jobid,
1326 newjob->progs[newjob->num_progs - 1].pid);
1327 last_jobid = newjob->jobid;
1328 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1330 newjob->job_list->fg = thejob;
1332 /* move the new process group into the foreground */
1333 /* suppress messages when run from /linuxrc mag@sysgo.de */
1334 if (tcsetpgrp(shell_terminal, newjob->pgrp) && errno != ENOTTY)
1335 bb_perror_msg("tcsetpgrp");
1340 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1342 /* struct job *thejob; */
1344 int nextin, nextout;
1345 int pipefds[2]; /* pipefd[0] is for reading */
1346 struct built_in_command *x;
1347 struct child_prog *child;
1349 nextin = 0, nextout = 1;
1350 for (i = 0; i < newjob->num_progs; i++) {
1351 child = & (newjob->progs[i]);
1353 if ((i + 1) < newjob->num_progs) {
1354 if (pipe(pipefds)<0) bb_perror_msg_and_die("pipe");
1355 nextout = pipefds[1];
1357 if (outpipe[1]!=-1) {
1358 nextout = outpipe[1];
1365 /* Check if the command matches any non-forking builtins,
1366 * but only if this is a simple command.
1367 * Non-forking builtins within pipes have to fork anyway,
1368 * and are handled in pseudo_exec. "echo foo | read bar"
1369 * is doomed to failure, and doesn't work on bash, either.
1371 if (newjob->num_progs == 1) {
1372 for (x = bltins; x->cmd; x++) {
1373 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1375 int squirrel[] = {-1, -1, -1};
1376 setup_redirects(child, squirrel);
1377 rcode = x->function(child);
1378 restore_redirects(squirrel);
1384 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
1385 if (!(child->pid = fork()))
1387 if (!(child->pid = vfork()))
1390 /* Set the handling for job control signals back to the default. */
1391 signal(SIGINT, SIG_DFL);
1392 signal(SIGQUIT, SIG_DFL);
1393 signal(SIGTSTP, SIG_DFL);
1394 signal(SIGTTIN, SIG_DFL);
1395 signal(SIGTTOU, SIG_DFL);
1396 signal(SIGCHLD, SIG_DFL);
1400 if (outpipe[1]!=-1) {
1410 dup2(nextout, 2); /* Really? */
1415 /* explicit redirects override pipes */
1416 setup_redirects(child,NULL);
1420 if (outpipe[1]!=-1) {
1424 /* put our child in the process group whose leader is the
1425 first process in this pipe */
1426 setpgid(child->pid, newjob->progs[0].pid);
1432 /* If there isn't another process, nextin is garbage
1433 but it doesn't matter */
1434 nextin = pipefds[0];
1437 newjob->pgrp = newjob->progs[0].pid;
1439 insert_job(newjob, inbg);
1444 static int busy_loop(FILE * input)
1447 char *next_command = NULL;
1452 #ifdef CONFIG_LASH_JOB_CONTROL
1454 /* save current owner of TTY so we can restore it on exit */
1455 parent_pgrp = tcgetpgrp(shell_terminal);
1457 newjob.job_list = &job_list;
1458 newjob.job_context = DEFAULT_CONTEXT;
1460 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1464 /* no job is in the foreground */
1466 /* see if any background processes have exited */
1467 checkjobs(&job_list);
1469 if (!next_command) {
1470 if (get_command(input, command))
1472 next_command = command;
1475 if (! expand_arguments(next_command)) {
1477 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1478 next_command = NULL;
1482 if (!parse_command(&next_command, &newjob, &inbg) &&
1484 int pipefds[2] = {-1,-1};
1485 debug_printf( "job=%p fed to run_command by busy_loop()'\n",
1487 run_command(&newjob, inbg, pipefds);
1491 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1492 next_command = NULL;
1495 /* a job is running in the foreground; wait for it */
1497 while (!job_list.fg->progs[i].pid ||
1498 job_list.fg->progs[i].is_stopped == 1) i++;
1500 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0) {
1501 if (errno != ECHILD) {
1502 bb_perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1506 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1507 /* the child exited */
1508 job_list.fg->running_progs--;
1509 job_list.fg->progs[i].pid = 0;
1511 last_return_code=WEXITSTATUS(status);
1513 if (!job_list.fg->running_progs) {
1515 remove_job(&job_list, job_list.fg);
1519 #ifdef CONFIG_LASH_JOB_CONTROL
1521 /* the child was stopped */
1522 job_list.fg->stopped_progs++;
1523 job_list.fg->progs[i].is_stopped = 1;
1525 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1526 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1527 "Stopped", job_list.fg->text);
1533 /* move the shell to the foreground */
1534 /* suppress messages when run from /linuxrc mag@sysgo.de */
1535 if (tcsetpgrp(shell_terminal, getpgrp()) && errno != ENOTTY)
1536 bb_perror_msg("tcsetpgrp");
1543 #ifdef CONFIG_LASH_JOB_CONTROL
1544 /* return controlling TTY back to parent process group before exiting */
1545 if (tcsetpgrp(shell_terminal, parent_pgrp) && errno != ENOTTY)
1546 bb_perror_msg("tcsetpgrp");
1549 /* return exit status if called with "-c" */
1550 if (input == NULL && WIFEXITED(status))
1551 return WEXITSTATUS(status);
1556 #ifdef CONFIG_FEATURE_CLEAN_UP
1557 void free_memory(void)
1559 if (cwd && cwd!=bb_msg_unknown) {
1562 if (local_pending_command)
1563 free(local_pending_command);
1565 if (job_list.fg && !job_list.fg->running_progs) {
1566 remove_job(&job_list, job_list.fg);
1571 #ifdef CONFIG_LASH_JOB_CONTROL
1572 /* Make sure we have a controlling tty. If we get started under a job
1573 * aware app (like bash for example), make sure we are now in charge so
1574 * we don't fight over who gets the foreground */
1575 static void setup_job_control(void)
1580 /* Loop until we are in the foreground. */
1581 while ((status = tcgetpgrp (shell_terminal)) >= 0) {
1582 if (status == (shell_pgrp = getpgrp ())) {
1585 kill (- shell_pgrp, SIGTTIN);
1588 /* Ignore interactive and job-control signals. */
1589 signal(SIGINT, SIG_IGN);
1590 signal(SIGQUIT, SIG_IGN);
1591 signal(SIGTSTP, SIG_IGN);
1592 signal(SIGTTIN, SIG_IGN);
1593 signal(SIGTTOU, SIG_IGN);
1594 signal(SIGCHLD, SIG_IGN);
1596 /* Put ourselves in our own process group. */
1598 shell_pgrp = getpid ();
1599 setpgid (shell_pgrp, shell_pgrp);
1601 /* Grab control of the terminal. */
1602 tcsetpgrp(shell_terminal, shell_pgrp);
1605 static inline void setup_job_control(void)
1610 int lash_main(int argc_l, char **argv_l)
1612 int opt, interactive=FALSE;
1613 FILE *input = stdin;
1617 /* These variables need re-initializing when recursing */
1619 local_pending_command = NULL;
1620 close_me_head = NULL;
1621 job_list.head = NULL;
1625 if (argv[0] && argv[0][0] == '-') {
1627 prof_input = fopen("/etc/profile", "r");
1629 int tmp_fd = fileno(prof_input);
1631 /* Now run the file */
1632 busy_loop(prof_input);
1634 mark_closed(tmp_fd);
1638 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1642 if (local_pending_command != 0)
1643 bb_error_msg_and_die("multiple -c arguments");
1644 local_pending_command = bb_xstrdup(argv[optind]);
1655 /* A shell is interactive if the `-i' flag was given, or if all of
1656 * the following conditions are met:
1658 * no arguments remaining or the -s flag given
1659 * standard input is a terminal
1660 * standard output is a terminal
1661 * Refer to Posix.2, the description of the `sh' utility. */
1662 if (argv[optind]==NULL && input==stdin &&
1663 isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
1666 setup_job_control();
1667 if (interactive==TRUE) {
1668 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1669 /* Looks like they want an interactive shell */
1670 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
1671 printf( "\n\n" BB_BANNER " Built-in shell (lash)\n");
1672 printf( "Enter 'help' for a list of built-in commands.\n\n");
1674 } else if (local_pending_command==NULL) {
1675 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1676 input = bb_xfopen(argv[optind], "r");
1677 mark_open(fileno(input)); /* be lazy, never mark this closed */
1680 /* initialize the cwd -- this is never freed...*/
1683 cwd = bb_msg_unknown;
1685 #ifdef CONFIG_FEATURE_CLEAN_UP
1686 atexit(free_memory);
1689 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1690 cmdedit_set_initial_prompt();
1695 return (busy_loop(input));