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...
59 #include <sys/ioctl.h>
67 #if ( (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1) ) || defined (__UCLIBC__)
69 #define expand_t wordexp_t
70 #undef BB_FEATURE_SH_BACKTICKS
73 #define expand_t glob_t
79 static const int MAX_LINE = 256; /* size of input buffer for cwd data */
80 static const int MAX_READ = 128; /* size of input buffer for `read' builtin */
81 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
84 enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
88 static const unsigned int DEFAULT_CONTEXT=0x1;
89 static const unsigned int IF_TRUE_CONTEXT=0x2;
90 static const unsigned int IF_FALSE_CONTEXT=0x4;
91 static const unsigned int THEN_EXP_CONTEXT=0x8;
92 static const unsigned int ELSE_EXP_CONTEXT=0x10;
96 struct job *head; /* head of list of running jobs */
97 struct job *fg; /* current foreground job */
100 struct redir_struct {
101 enum redir_type type; /* type of redirection */
102 int fd; /* file descriptor being redirected */
103 char *filename; /* file to redirect fd to */
107 pid_t pid; /* 0 if exited */
108 char **argv; /* program name and arguments */
109 int num_redirects; /* elements in redirection array */
110 struct redir_struct *redirects; /* I/O redirects */
111 int is_stopped; /* is the program currently running? */
112 struct job *family; /* pointer back to the child's parent job */
116 int jobid; /* job number */
117 int num_progs; /* total number of programs in job */
118 int running_progs; /* number of programs running */
119 char *text; /* name of job */
120 char *cmdbuf; /* buffer various argv's point into */
121 pid_t pgrp; /* process group ID for the job */
122 struct child_prog *progs; /* array of programs in job */
123 struct job *next; /* to track background commands */
124 int stopped_progs; /* number of programs alive, but stopped */
125 unsigned int job_context; /* bitmask defining current context */
126 struct jobset *job_list;
129 struct built_in_command {
130 char *cmd; /* name */
131 char *descr; /* description */
132 int (*function) (struct child_prog *); /* function ptr */
137 struct close_me *next;
140 /* function prototypes for builtins */
141 static int builtin_cd(struct child_prog *cmd);
142 static int builtin_env(struct child_prog *dummy);
143 static int builtin_exec(struct child_prog *cmd);
144 static int builtin_exit(struct child_prog *cmd);
145 static int builtin_fg_bg(struct child_prog *cmd);
146 static int builtin_help(struct child_prog *cmd);
147 static int builtin_jobs(struct child_prog *dummy);
148 static int builtin_pwd(struct child_prog *dummy);
149 static int builtin_export(struct child_prog *cmd);
150 static int builtin_source(struct child_prog *cmd);
151 static int builtin_unset(struct child_prog *cmd);
152 static int builtin_read(struct child_prog *cmd);
153 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
154 static int builtin_if(struct child_prog *cmd);
155 static int builtin_then(struct child_prog *cmd);
156 static int builtin_else(struct child_prog *cmd);
157 static int builtin_fi(struct child_prog *cmd);
158 /* function prototypes for shell stuff */
159 static int run_command_predicate(char *cmd);
163 /* function prototypes for shell stuff */
164 static void mark_open(int fd);
165 static void mark_closed(int fd);
166 static void close_all(void);
167 static void checkjobs(struct jobset *job_list);
168 static int get_command(FILE * source, char *command);
169 static int parse_command(char **command_ptr, struct job *job, int *inbg);
170 static int run_command(struct job *newjob, int inbg, int outpipe[2]);
171 static int pseudo_exec(struct child_prog *cmd) __attribute__ ((noreturn));
172 static int busy_loop(FILE * input);
175 /* Table of built-in functions (these are non-forking builtins, meaning they
176 * can change global variables in the parent shell process but they will not
177 * work with pipes and redirects; 'unset foo | whatever' will not work) */
178 static struct built_in_command bltins[] = {
179 {"bg", "Resume a job in the background", builtin_fg_bg},
180 {"cd", "Change working directory", builtin_cd},
181 {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
182 {"exit", "Exit from shell()", builtin_exit},
183 {"fg", "Bring job into the foreground", builtin_fg_bg},
184 {"jobs", "Lists the active jobs", builtin_jobs},
185 {"export", "Set environment variable", builtin_export},
186 {"unset", "Unset environment variable", builtin_unset},
187 {"read", "Input environment variable", builtin_read},
188 {".", "Source-in and run commands in a file", builtin_source},
189 /* to do: add ulimit */
190 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
191 {"if", NULL, builtin_if},
192 {"then", NULL, builtin_then},
193 {"else", NULL, builtin_else},
194 {"fi", NULL, builtin_fi},
199 /* Table of forking built-in functions (things that fork cannot change global
200 * variables in the parent process, such as the current working directory) */
201 static struct built_in_command bltins_forking[] = {
202 {"env", "Print all environment variables", builtin_env},
203 {"pwd", "Print current directory", builtin_pwd},
204 {"help", "List shell built-in commands", builtin_help},
209 /* Variables we export */
210 unsigned int shell_context; /* Used in cmdedit.c to reset the
211 context when someone hits ^C */
214 /* Globals that are static to this file */
216 static char *local_pending_command = NULL;
217 static struct jobset job_list = { NULL, NULL };
220 static struct close_me *close_me_head;
221 #ifdef BB_FEATURE_SH_ENVIRONMENT
222 static int last_bg_pid;
223 static int last_return_code;
224 static int show_x_trace;
226 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
227 static char syntax_err[]="syntax error near unexpected token";
231 static inline void debug_printf(const char *format, ...)
234 va_start(args, format);
235 vfprintf(stderr, format, args);
239 static inline void debug_printf(const char *format, ...) { }
243 Most builtins need access to the struct child_prog that has
244 their arguments, previously coded as cmd->progs[0]. That coding
245 can exhibit a bug, if the builtin is not the first command in
246 a pipeline: "echo foo | exec sort" will attempt to exec foo.
248 builtin previous use notes
249 ------ ----------------- ---------
252 exec cmd->progs[0] squashed bug: didn't look for applets or forking builtins
254 fg_bg cmd->progs[0], job_list->head, job_list->fg
258 export cmd->progs[0] passes cmd, job_list to builtin_env(), which ignores them
262 if cmd->job_context, cmd->text
263 then cmd->job_context, cmd->text
264 else cmd->job_context, cmd->text
267 The use of cmd->text by if/then/else/fi is hopelessly hacky.
268 Would it work to increment cmd->progs[0]->argv and recurse,
269 somewhat like builtin_exec does?
271 I added "struct job *family;" to struct child_prog,
272 and switched API to builtin_foo(struct child_prog *child);
273 So cmd->text becomes child->family->text
274 cmd->job_context becomes child->family->job_context
275 cmd->progs[0] becomes *child
276 job_list becomes child->family->job_list
279 /* built-in 'cd <path>' handler */
280 static int builtin_cd(struct child_prog *child)
284 if (child->argv[1] == NULL)
285 newdir = getenv("HOME");
287 newdir = child->argv[1];
289 printf("cd: %s: %s\n", newdir, strerror(errno));
292 getcwd(cwd, sizeof(char)*MAX_LINE);
297 /* built-in 'env' handler */
298 static int builtin_env(struct child_prog *dummy)
302 for (e = environ; *e; e++) {
308 /* built-in 'exec' handler */
309 static int builtin_exec(struct child_prog *child)
311 if (child->argv[1] == NULL)
312 return EXIT_SUCCESS; /* Really? */
319 /* built-in 'exit' handler */
320 static int builtin_exit(struct child_prog *child)
322 if (child->argv[1] == NULL)
325 exit (atoi(child->argv[1]));
328 /* built-in 'fg' and 'bg' handler */
329 static int builtin_fg_bg(struct child_prog *child)
332 struct job *job=NULL;
334 if (!child->argv[1] || child->argv[2]) {
335 error_msg("%s: exactly one argument is expected",
340 if (sscanf(child->argv[1], "%%%d", &jobNum) != 1) {
341 error_msg("%s: bad argument '%s'",
342 child->argv[0], child->argv[1]);
346 for (job = child->family->job_list->head; job; job = job->next) {
347 if (job->jobid == jobNum) {
353 error_msg("%s: unknown job %d",
354 child->argv[0], jobNum);
358 if (*child->argv[0] == 'f') {
359 /* Make this job the foreground job */
360 /* suppress messages when run from /linuxrc mag@sysgo.de */
361 if (tcsetpgrp(0, job->pgrp) && errno != ENOTTY)
362 perror_msg("tcsetpgrp");
363 child->family->job_list->fg = job;
366 /* Restart the processes in the job */
367 for (i = 0; i < job->num_progs; i++)
368 job->progs[i].is_stopped = 0;
370 kill(-job->pgrp, SIGCONT);
372 job->stopped_progs = 0;
377 /* built-in 'help' handler */
378 static int builtin_help(struct child_prog *dummy)
380 struct built_in_command *x;
382 printf("\nBuilt-in commands:\n");
383 printf("-------------------\n");
384 for (x = bltins; x->cmd; x++) {
387 printf("%s\t%s\n", x->cmd, x->descr);
389 for (x = bltins_forking; x->cmd; x++) {
392 printf("%s\t%s\n", x->cmd, x->descr);
398 /* built-in 'jobs' handler */
399 static int builtin_jobs(struct child_prog *child)
404 for (job = child->family->job_list->head; job; job = job->next) {
405 if (job->running_progs == job->stopped_progs)
406 status_string = "Stopped";
408 status_string = "Running";
410 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
416 /* built-in 'pwd' handler */
417 static int builtin_pwd(struct child_prog *dummy)
419 getcwd(cwd, MAX_LINE);
420 printf( "%s\n", cwd);
424 /* built-in 'export VAR=value' handler */
425 static int builtin_export(struct child_prog *child)
429 if (child->argv[1] == NULL) {
430 return (builtin_env(child));
432 res = putenv(child->argv[1]);
434 fprintf(stderr, "export: %s\n", strerror(errno));
438 /* built-in 'read VAR' handler */
439 static int builtin_read(struct child_prog *child)
441 int res = 0, len, newlen;
443 char string[MAX_READ];
445 if (child->argv[1]) {
446 /* argument (VAR) given: put "VAR=" into buffer */
447 strcpy(string, child->argv[1]);
448 len = strlen(string);
451 fgets(&string[len], sizeof(string) - len, stdin); /* read string */
452 newlen = strlen(string);
454 string[--newlen] = '\0'; /* chomp trailing newline */
456 ** string should now contain "VAR=<value>"
457 ** copy it (putenv() won't do that, so we must make sure
458 ** the string resides in a static buffer!)
461 if((s = strdup(string)))
464 fprintf(stderr, "read: %s\n", strerror(errno));
467 fgets(string, sizeof(string), stdin);
472 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
473 /* Built-in handler for 'if' commands */
474 static int builtin_if(struct child_prog *child)
476 struct job *cmd = child->family;
478 char* charptr1=cmd->text+3; /* skip over the leading 'if ' */
480 /* Now run the 'if' command */
481 debug_printf( "job=%p entering builtin_if ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
482 status = run_command_predicate(charptr1);
483 debug_printf( "if test returned ");
485 debug_printf( "TRUE\n");
486 cmd->job_context |= IF_TRUE_CONTEXT;
488 debug_printf( "FALSE\n");
489 cmd->job_context |= IF_FALSE_CONTEXT;
491 debug_printf("job=%p builtin_if set job context to %x\n", cmd, cmd->job_context);
497 /* Built-in handler for 'then' (part of the 'if' command) */
498 static int builtin_then(struct child_prog *child)
500 struct job *cmd = child->family;
501 char* charptr1=cmd->text+5; /* skip over the leading 'then ' */
503 debug_printf( "job=%p entering builtin_then ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
504 if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
505 shell_context = 0; /* Reset the shell's context on an error */
506 error_msg("%s `then'", syntax_err);
510 cmd->job_context |= THEN_EXP_CONTEXT;
511 debug_printf("job=%p builtin_then set job context to %x\n", cmd, cmd->job_context);
513 /* If the if result was FALSE, skip the 'then' stuff */
514 if (cmd->job_context & IF_FALSE_CONTEXT) {
518 /* Seems the if result was TRUE, so run the 'then' command */
519 debug_printf( "'then' now running '%s'\n", charptr1);
521 return(run_command_predicate(charptr1));
524 /* Built-in handler for 'else' (part of the 'if' command) */
525 static int builtin_else(struct child_prog *child)
527 struct job *cmd = child->family;
528 char* charptr1=cmd->text+5; /* skip over the leading 'else ' */
530 debug_printf( "job=%p entering builtin_else ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
532 if (! (cmd->job_context & THEN_EXP_CONTEXT)) {
533 shell_context = 0; /* Reset the shell's context on an error */
534 error_msg("%s `else'", syntax_err);
537 /* If the if result was TRUE, skip the 'else' stuff */
538 if (cmd->job_context & IF_TRUE_CONTEXT) {
542 cmd->job_context |= ELSE_EXP_CONTEXT;
543 debug_printf("job=%p builtin_else set job context to %x\n", cmd, cmd->job_context);
545 /* Now run the 'else' command */
546 debug_printf( "'else' now running '%s'\n", charptr1);
547 return(run_command_predicate(charptr1));
550 /* Built-in handler for 'fi' (part of the 'if' command) */
551 static int builtin_fi(struct child_prog *child)
553 struct job *cmd = child->family;
554 debug_printf( "job=%p entering builtin_fi ('%s')-- context=%d\n", cmd, "", cmd->job_context);
555 if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
556 shell_context = 0; /* Reset the shell's context on an error */
557 error_msg("%s `fi'", syntax_err);
560 /* Clear out the if and then context bits */
561 cmd->job_context &= ~(IF_TRUE_CONTEXT|IF_FALSE_CONTEXT|THEN_EXP_CONTEXT|ELSE_EXP_CONTEXT);
562 debug_printf("job=%p builtin_fi set job context to %x\n", cmd, cmd->job_context);
568 /* Built-in '.' handler (read-in and execute commands from file) */
569 static int builtin_source(struct child_prog *child)
575 if (child->argv[1] == NULL)
578 input = fopen(child->argv[1], "r");
580 printf( "Couldn't open file '%s'\n", child->argv[1]);
586 /* Now run the file */
587 status = busy_loop(input);
593 /* built-in 'unset VAR' handler */
594 static int builtin_unset(struct child_prog *child)
596 if (child->argv[1] == NULL) {
597 printf( "unset: parameter required.\n");
600 unsetenv(child->argv[1]);
604 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
605 /* currently used by if/then/else.
607 * Reparsing the command line for this purpose is gross,
608 * incorrect, and fundamentally unfixable; in particular,
609 * think about what happens with command substitution.
610 * We really need to pull out the run, wait, return status
611 * functionality out of busy_loop so we can child->argv++
612 * and use that, without going back through parse_command.
614 static int run_command_predicate(char *cmd)
617 local_pending_command = xmalloc(n+1);
618 strncpy(local_pending_command, cmd, n);
619 local_pending_command[n]='\0';
620 return( busy_loop(NULL));
624 static void mark_open(int fd)
626 struct close_me *new = xmalloc(sizeof(struct close_me));
628 new->next = close_me_head;
632 static void mark_closed(int fd)
634 struct close_me *tmp;
635 if (close_me_head == NULL || close_me_head->fd != fd)
636 error_msg_and_die("corrupt close_me");
638 close_me_head = close_me_head->next;
642 static void close_all()
644 struct close_me *c, *tmp;
645 for (c=close_me_head; c; c=tmp) {
650 close_me_head = NULL;
654 /* free up all memory from a job */
655 static void free_job(struct job *cmd)
659 for (i = 0; i < cmd->num_progs; i++) {
660 free(cmd->progs[i].argv);
661 if (cmd->progs[i].redirects)
662 free(cmd->progs[i].redirects);
668 memset(cmd, 0, sizeof(struct job));
671 /* remove a job from the job_list */
672 static void remove_job(struct jobset *job_list, struct job *job)
677 if (job == job_list->head) {
678 job_list->head = job->next;
680 prevjob = job_list->head;
681 while (prevjob->next != job)
682 prevjob = prevjob->next;
683 prevjob->next = job->next;
689 /* Checks to see if any background processes have exited -- if they
690 have, figure out why and see if a job has completed */
691 static void checkjobs(struct jobset *job_list)
698 while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
699 for (job = job_list->head; job; job = job->next) {
701 while (prognum < job->num_progs &&
702 job->progs[prognum].pid != childpid) prognum++;
703 if (prognum < job->num_progs)
707 /* This happens on backticked commands */
711 if (WIFEXITED(status) || WIFSIGNALED(status)) {
713 job->running_progs--;
714 job->progs[prognum].pid = 0;
716 if (!job->running_progs) {
717 printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text);
718 remove_job(job_list, job);
722 job->stopped_progs++;
723 job->progs[prognum].is_stopped = 1;
725 if (job->stopped_progs == job->num_progs) {
726 printf(JOB_STATUS_FORMAT, job->jobid, "Stopped",
732 if (childpid == -1 && errno != ECHILD)
733 perror_msg("waitpid");
736 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
737 * and stderr if they are redirected. */
738 static int setup_redirects(struct child_prog *prog, int squirrel[])
743 struct redir_struct *redir = prog->redirects;
745 for (i = 0; i < prog->num_redirects; i++, redir++) {
746 switch (redir->type) {
750 case REDIRECT_OVERWRITE:
751 mode = O_WRONLY | O_CREAT | O_TRUNC;
753 case REDIRECT_APPEND:
754 mode = O_WRONLY | O_CREAT | O_APPEND;
758 openfd = open(redir->filename, mode, 0666);
760 /* this could get lost if stderr has been redirected, but
761 bash and ash both lose it as well (though zsh doesn't!) */
762 error_msg("error opening %s: %s", redir->filename,
767 if (openfd != redir->fd) {
768 if (squirrel && redir->fd < 3) {
769 squirrel[redir->fd] = dup(redir->fd);
771 dup2(openfd, redir->fd);
779 static void restore_redirects(int squirrel[])
782 for (i=0; i<3; i++) {
785 /* No error checking. I sure wouldn't know what
786 * to do with an error if I found one! */
793 #if defined(BB_FEATURE_SH_SIMPLE_PROMPT)
794 static char* setup_prompt_string(int state)
796 char prompt_str[BUFSIZ];
798 /* Set up the prompt */
801 sprintf(prompt_str, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
803 strcpy(prompt_str,"> ");
806 return(strdup(prompt_str)); /* Must free this memory */
811 static char* setup_prompt_string(int state)
813 char user[9],buf[255],*s;
815 char prompt_str[BUFSIZ];
817 /* Set up the prompt */
819 /* get User Name and setup prompt */
820 strcpy(prompt,( geteuid() != 0 ) ? "$ ":"# ");
821 my_getpwuid(user, geteuid());
824 gethostname(buf, 255);
825 s = strchr(buf, '.');
834 snprintf(prompt_str, BUFSIZ-1, "[%s@%s %s]%s", user, buf,
835 get_last_path_component(cwd), prompt);
837 sprintf(prompt_str, "%s", prompt);
839 return(strdup(prompt_str)); /* Must free this memory */
844 static int get_command(FILE * source, char *command)
848 if (source == NULL) {
849 if (local_pending_command) {
850 /* a command specified (-c option): return it & mark it done */
851 strcpy(command, local_pending_command);
852 free(local_pending_command);
853 local_pending_command = NULL;
859 if (source == stdin) {
860 prompt_str = setup_prompt_string(shell_context);
862 #ifdef BB_FEATURE_SH_COMMAND_EDITING
864 ** enable command line editing only while a command line
865 ** is actually being read; otherwise, we'll end up bequeathing
866 ** atexit() handlers and other unwanted stuff to our
867 ** child processes (rob@sysgo.de)
869 cmdedit_read_input(prompt_str, command);
874 fputs(prompt_str, stdout);
879 if (!fgets(command, BUFSIZ - 2, source)) {
885 /* remove trailing newline */
891 #ifdef BB_FEATURE_SH_ENVIRONMENT
892 static char* itoa(register int i)
894 static char a[7]; /* Max 7 ints */
895 register char *b = a + sizeof(a) - 1;
903 *--b = '0' + (i % 10);
913 static int expand_arguments(char *command)
915 #ifdef BB_FEATURE_SH_ENVIRONMENT
916 expand_t expand_result;
917 char *src, *dst, *var;
918 int i=0, length, total_length=0, retval;
919 const char *out_of_space = "out of space during expansion";
922 /* get rid of the terminating \n */
925 #ifdef BB_FEATURE_SH_ENVIRONMENT
928 #if ( (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1) ) || defined (__UCLIBC__)
929 /* This first part uses wordexp() which is a wonderful C lib
930 * function which expands nearly everything. */
931 retval = wordexp (command, &expand_result, 0);
932 if (retval == WRDE_NOSPACE) {
933 /* Mem may have been allocated... */
934 wordfree (&expand_result);
935 error_msg(out_of_space);
939 /* Some other error. */
940 error_msg("syntax error");
944 /* Convert from char** (one word per string) to a simple char*,
945 * but don't overflow command which is BUFSIZ in length */
947 while (i < expand_result.we_wordc && total_length < BUFSIZ) {
948 length=strlen(expand_result.we_wordv[i])+1;
949 if (BUFSIZ-total_length-length <= 0) {
950 error_msg(out_of_space);
953 strcat(command+total_length, expand_result.we_wordv[i++]);
954 strcat(command+total_length, " ");
955 total_length+=length;
957 wordfree (&expand_result);
960 /* Ok. They don't have a recent glibc and they don't have uClibc. Chances
961 * are about 100% they don't have wordexp(). So instead the best we can do
962 * is use glob and then fixup environment variables and such ourselves.
963 * This is better then nothing, but certainly not perfect */
965 /* It turns out that glob is very stupid. We have to feed it one word at a
966 * time since it can't cope with a full string. Here we convert command
967 * (char*) into cmd (char**, one word per string) */
970 int flags = GLOB_NOCHECK|GLOB_BRACE|GLOB_TILDE;
972 /* We need a clean copy, so strsep can mess up the copy while
973 * we write stuff into the original (in a minute) */
974 char * cmd = strdup(command);
976 for (tmpcmd = cmd; (tmpcmd = strsep(&cmd, " \t")) != NULL;) {
979 retval = glob(tmpcmd, flags, NULL, &expand_result);
980 if (retval == GLOB_NOSPACE) {
981 /* Mem may have been allocated... */
982 globfree (&expand_result);
983 error_msg(out_of_space);
985 } else if (retval != 0) {
986 /* Some other error. GLOB_NOMATCH shouldn't
987 * happen because of the GLOB_NOCHECK flag in
989 error_msg("syntax error");
992 /* Convert from char** (one word per string) to a simple char*,
993 * but don't overflow command which is BUFSIZ in length */
994 for (i=0; i < expand_result.gl_pathc; i++) {
995 length=strlen(expand_result.gl_pathv[i])+1;
996 if (BUFSIZ-total_length-length <= 0) {
997 error_msg(out_of_space);
1000 strcat(command+total_length, expand_result.gl_pathv[i]);
1001 strcat(command+total_length, " ");
1002 total_length+=length;
1004 globfree (&expand_result);
1013 /* Now do the shell variable substitutions which
1014 * wordexp can't do for us, namely $? and $! */
1016 while((dst = strchr(src,'$')) != NULL){
1017 printf("dollar '%s'\n", dst);
1021 var = itoa(last_return_code);
1024 if (last_bg_pid==-1)
1027 var = itoa(last_bg_pid);
1029 /* Everything else like $$, $#, $[0-9], etc should all be
1030 * expanded by wordexp(), so we can in theory skip that stuff
1031 * here, but just to be on the safe side (i.e. since uClibc
1032 * wordexp doesn't do this stuff yet), lets leave it in for
1035 var = itoa(getpid());
1040 case '0':case '1':case '2':case '3':case '4':
1041 case '5':case '6':case '7':case '8':case '9':
1043 int index=*(dst + 1)-48;
1044 if (index >= argc) {
1054 /* a single character construction was found, and
1055 * already handled in the case statement */
1058 /* Looks like an environment variable */
1060 src=strpbrk(dst+1, " \t~`!$^&*()=|\\{}[];\"'<>?.");
1062 src = dst+strlen(dst);
1065 *src='\0'; /* temporary */
1066 var = getenv(dst + 1);
1070 /* Seems we got an un-expandable variable. So delete it. */
1074 int subst_len = strlen(var);
1075 int trail_len = strlen(src);
1076 if (dst+subst_len+trail_len >= command+BUFSIZ) {
1077 error_msg(out_of_space);
1080 /* Move stuff to the end of the string to accommodate
1081 * filling the created gap with the new stuff */
1082 memmove(dst+subst_len, src, trail_len);
1083 *(dst+subst_len+trail_len)='\0';
1084 /* Now copy in the new stuff */
1085 memcpy(dst, var, subst_len);
1086 src = dst+subst_len;
1094 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
1095 line). If a valid command is found, command_ptr is set to point to
1096 the beginning of the next command (if the original command had more
1097 then one job associated with it) or NULL if no more commands are
1099 static int parse_command(char **command_ptr, struct job *job, int *inbg)
1102 char *return_command = NULL;
1103 char *src, *buf, *chptr;
1110 struct child_prog *prog;
1112 /* skip leading white space */
1113 while (**command_ptr && isspace(**command_ptr))
1116 /* this handles empty lines or leading '#' characters */
1117 if (!**command_ptr || (**command_ptr == '#')) {
1124 job->progs = xmalloc(sizeof(*job->progs));
1126 /* We set the argv elements to point inside of this string. The
1127 memory is freed by free_job(). Allocate twice the original
1128 length in case we need to quote every single character.
1130 Getting clean memory relieves us of the task of NULL
1131 terminating things and makes the rest of this look a bit
1132 cleaner (though it is, admittedly, a tad less efficient) */
1133 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
1137 prog->num_redirects = 0;
1138 prog->redirects = NULL;
1139 prog->is_stopped = 0;
1143 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1144 prog->argv[0] = job->cmdbuf;
1148 while (*src && !done) {
1149 if (quote == *src) {
1155 error_msg("character expected after \\");
1160 /* in shell, "\'" should yield \' */
1161 if (*src != quote) {
1165 } else if (*src == '*' || *src == '?' || *src == '[' ||
1166 *src == ']') *buf++ = '\\';
1168 } else if (isspace(*src)) {
1169 if (*prog->argv[argc_l]) {
1171 /* +1 here leaves room for the NULL which ends argv */
1172 if ((argc_l + 1) == argv_alloced) {
1174 prog->argv = xrealloc(prog->argv,
1175 sizeof(*prog->argv) *
1178 prog->argv[argc_l] = buf;
1187 case '#': /* comment */
1194 case '>': /* redirects */
1196 i = prog->num_redirects++;
1197 prog->redirects = xrealloc(prog->redirects,
1198 sizeof(*prog->redirects) *
1201 prog->redirects[i].fd = -1;
1202 if (buf != prog->argv[argc_l]) {
1203 /* the stuff before this character may be the file number
1205 prog->redirects[i].fd =
1206 strtol(prog->argv[argc_l], &chptr, 10);
1208 if (*chptr && *prog->argv[argc_l]) {
1210 prog->argv[argc_l] = buf;
1214 if (prog->redirects[i].fd == -1) {
1216 prog->redirects[i].fd = 1;
1218 prog->redirects[i].fd = 0;
1221 if (*src++ == '>') {
1223 prog->redirects[i].type =
1224 REDIRECT_APPEND, src++;
1226 prog->redirects[i].type = REDIRECT_OVERWRITE;
1228 prog->redirects[i].type = REDIRECT_INPUT;
1231 /* This isn't POSIX sh compliant. Oh well. */
1233 while (isspace(*chptr))
1237 error_msg("file name expected after %c", *src);
1243 prog->redirects[i].filename = buf;
1244 while (*chptr && !isspace(*chptr))
1247 src = chptr - 1; /* we src++ later */
1248 prog->argv[argc_l] = ++buf;
1251 case '|': /* pipe */
1252 /* finish this command */
1253 if (*prog->argv[argc_l])
1256 error_msg("empty command in pipe");
1261 prog->argv[argc_l] = NULL;
1263 /* and start the next */
1265 job->progs = xrealloc(job->progs,
1266 sizeof(*job->progs) * job->num_progs);
1267 prog = job->progs + (job->num_progs - 1);
1268 prog->num_redirects = 0;
1269 prog->redirects = NULL;
1270 prog->is_stopped = 0;
1275 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1276 prog->argv[0] = ++buf;
1279 while (*src && isspace(*src))
1283 error_msg("empty command in pipe");
1288 src--; /* we'll ++ it at the end of the loop */
1292 case '&': /* background */
1294 case ';': /* multiple commands */
1296 return_command = *command_ptr + (src - *command_ptr) + 1;
1299 #ifdef BB_FEATURE_SH_BACKTICKS
1301 /* Exec a backtick-ed command */
1302 /* Besides any previous brokenness, I have not
1303 * updated backtick handling for close_me support.
1304 * I don't know if it needs it or not. -- LRD */
1306 char* charptr1=NULL, *charptr2;
1309 struct jobset njob_list = { NULL, NULL };
1313 ptr=strchr(++src, '`');
1315 fprintf(stderr, "Unmatched '`' in command\n");
1320 /* Make some space to hold just the backticked command */
1321 charptr1 = charptr2 = xmalloc(1+ptr-src);
1322 memcpy(charptr1, src, ptr-src);
1323 charptr1[ptr-src] = '\0';
1324 newjob = xmalloc(sizeof(struct job));
1325 newjob->job_list = &njob_list;
1326 /* Now parse and run the backticked command */
1327 if (!parse_command(&charptr1, newjob, inbg)
1328 && newjob->num_progs) {
1330 run_command(newjob, 0, pipefd);
1332 checkjobs(job->job_list);
1333 free_job(newjob); /* doesn't actually free newjob,
1334 looks like a memory leak */
1337 /* Make a copy of any stuff left over in the command
1338 * line after the second backtick */
1339 charptr2 = xmalloc(strlen(ptr)+1);
1340 memcpy(charptr2, ptr+1, strlen(ptr));
1343 /* Copy the output from the backtick-ed command into the
1344 * command line, making extra room as needed */
1346 charptr1 = xmalloc(BUFSIZ);
1347 while ( (size=full_read(pipefd[0], charptr1, BUFSIZ-1)) >0) {
1348 int newsize=src - *command_ptr + size + 1 + strlen(charptr2);
1349 if (newsize > BUFSIZ) {
1350 *command_ptr=xrealloc(*command_ptr, newsize);
1352 memcpy(src, charptr1, size);
1360 /* Now paste into the *command_ptr all the stuff
1361 * leftover after the second backtick */
1362 memcpy(src, charptr2, strlen(charptr2)+1);
1365 /* Now recursively call parse_command to deal with the new
1366 * and improved version of the command line with the backtick
1367 * results expanded in place... */
1369 struct jobset *jl=job->job_list;
1373 return(parse_command(command_ptr, job, inbg));
1376 #endif // BB_FEATURE_SH_BACKTICKS
1381 /* This is currently a little broken... */
1382 #ifdef HANDLE_CONTINUATION_CHARS
1383 /* They fed us a continuation char, so continue reading stuff
1384 * on the next line, then tack that onto the end of the current
1388 printf("erik: found a continue char at EOL...\n");
1389 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1390 if (get_command(input, command)) {
1391 error_msg("character expected after \\");
1396 newsize = strlen(*command_ptr) + strlen(command) + 2;
1397 if (newsize > BUFSIZ) {
1398 printf("erik: doing realloc\n");
1399 *command_ptr=xrealloc(*command_ptr, newsize);
1401 printf("erik: A: *command_ptr='%s'\n", *command_ptr);
1402 memcpy(--src, command, strlen(command));
1403 printf("erik: B: *command_ptr='%s'\n", *command_ptr);
1407 error_msg("character expected after \\");
1413 if (*src == '*' || *src == '[' || *src == ']'
1414 || *src == '?') *buf++ = '\\';
1423 if (*prog->argv[argc_l]) {
1430 prog->argv[argc_l] = NULL;
1432 if (!return_command) {
1433 job->text = xmalloc(strlen(*command_ptr) + 1);
1434 strcpy(job->text, *command_ptr);
1436 /* This leaves any trailing spaces, which is a bit sloppy */
1437 count = return_command - *command_ptr;
1438 job->text = xmalloc(count + 1);
1439 strncpy(job->text, *command_ptr, count);
1440 job->text[count] = '\0';
1443 *command_ptr = return_command;
1448 /* Run the child_prog, no matter what kind of command it uses.
1450 static int pseudo_exec(struct child_prog *child)
1452 struct built_in_command *x;
1453 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1457 /* Check if the command matches any of the non-forking builtins.
1458 * Depending on context, this might be redundant. But it's
1459 * easier to waste a few CPU cycles than it is to figure out
1460 * if this is one of those cases.
1462 for (x = bltins; x->cmd; x++) {
1463 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1464 exit(x->function(child));
1468 /* Check if the command matches any of the forking builtins. */
1469 for (x = bltins_forking; x->cmd; x++) {
1470 if (strcmp(child->argv[0], x->cmd) == 0) {
1472 exit (x->function(child));
1475 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1476 /* Check if the command matches any busybox internal
1477 * commands ("applets") here. Following discussions from
1478 * November 2000 on busybox@opensource.lineo.com, don't use
1479 * get_last_path_component(). This way explicit (with
1480 * slashes) filenames will never be interpreted as an
1481 * applet, just like with builtins. This way the user can
1482 * override an applet with an explicit filename reference.
1483 * The only downside to this change is that an explicit
1484 * /bin/foo invocation will fork and exec /bin/foo, even if
1485 * /bin/foo is a symlink to busybox.
1487 name = child->argv[0];
1489 #ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1490 /* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then
1491 * if you run /bin/cat, it will use BusyBox cat even if
1492 * /bin/cat exists on the filesystem and is _not_ busybox.
1493 * Some systems want this, others do not. Choose wisely. :-)
1495 name = get_last_path_component(name);
1499 char** argv=child->argv;
1501 for(argc_l=0;*argv!=NULL; argv++, argc_l++);
1503 run_applet_by_name(name, argc_l, child->argv);
1507 execvp(child->argv[0], child->argv);
1508 perror_msg_and_die("%s", child->argv[0]);
1511 static void insert_job(struct job *newjob, int inbg)
1514 struct jobset *job_list=newjob->job_list;
1516 /* find the ID for thejob to use */
1518 for (thejob = job_list->head; thejob; thejob = thejob->next)
1519 if (thejob->jobid >= newjob->jobid)
1520 newjob->jobid = thejob->jobid + 1;
1522 /* add thejob to the list of running jobs */
1523 if (!job_list->head) {
1524 thejob = job_list->head = xmalloc(sizeof(*thejob));
1526 for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1527 thejob->next = xmalloc(sizeof(*thejob));
1528 thejob = thejob->next;
1531 *thejob = *newjob; /* physically copy the struct job */
1532 thejob->next = NULL;
1533 thejob->running_progs = thejob->num_progs;
1534 thejob->stopped_progs = 0;
1537 /* we don't wait for background thejobs to return -- append it
1538 to the list of backgrounded thejobs and leave it alone */
1539 printf("[%d] %d\n", thejob->jobid,
1540 newjob->progs[newjob->num_progs - 1].pid);
1541 #ifdef BB_FEATURE_SH_ENVIRONMENT
1542 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1545 newjob->job_list->fg = thejob;
1547 /* move the new process group into the foreground */
1548 /* suppress messages when run from /linuxrc mag@sysgo.de */
1549 if (tcsetpgrp(0, newjob->pgrp) && errno != ENOTTY)
1550 perror_msg("tcsetpgrp");
1554 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1556 /* struct job *thejob; */
1558 int nextin, nextout;
1559 int pipefds[2]; /* pipefd[0] is for reading */
1560 struct built_in_command *x;
1561 struct child_prog *child;
1563 nextin = 0, nextout = 1;
1564 for (i = 0; i < newjob->num_progs; i++) {
1565 child = & (newjob->progs[i]);
1567 if ((i + 1) < newjob->num_progs) {
1568 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1569 nextout = pipefds[1];
1571 if (outpipe[1]!=-1) {
1572 nextout = outpipe[1];
1578 #ifdef BB_FEATURE_SH_ENVIRONMENT
1579 if (show_x_trace==TRUE) {
1582 for (j = 0; child->argv[j]; j++) {
1584 fputs(child->argv[j], stderr);
1586 fputc('\n', stderr);
1590 /* Check if the command matches any non-forking builtins,
1591 * but only if this is a simple command.
1592 * Non-forking builtins within pipes have to fork anyway,
1593 * and are handled in pseudo_exec. "echo foo | read bar"
1594 * is doomed to failure, and doesn't work on bash, either.
1596 if (newjob->num_progs == 1) {
1597 for (x = bltins; x->cmd; x++) {
1598 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1599 int squirrel[] = {-1, -1, -1};
1601 setup_redirects(child, squirrel);
1602 rcode = x->function(child);
1603 restore_redirects(squirrel);
1609 if (!(child->pid = fork())) {
1610 signal(SIGTTOU, SIG_DFL);
1614 if (outpipe[1]!=-1) {
1624 dup2(nextout, 2); /* Really? */
1629 /* explicit redirects override pipes */
1630 setup_redirects(child,NULL);
1634 if (outpipe[1]!=-1) {
1638 /* put our child in the process group whose leader is the
1639 first process in this pipe */
1640 setpgid(child->pid, newjob->progs[0].pid);
1646 /* If there isn't another process, nextin is garbage
1647 but it doesn't matter */
1648 nextin = pipefds[0];
1651 newjob->pgrp = newjob->progs[0].pid;
1653 insert_job(newjob, inbg);
1658 static int busy_loop(FILE * input)
1661 char *next_command = NULL;
1667 newjob.job_list = &job_list;
1668 newjob.job_context = DEFAULT_CONTEXT;
1670 /* save current owner of TTY so we can restore it on exit */
1671 parent_pgrp = tcgetpgrp(0);
1673 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1675 /* don't pay any attention to this signal; it just confuses
1676 things and isn't really meant for shells anyway */
1677 signal(SIGTTOU, SIG_IGN);
1681 /* no job is in the foreground */
1683 /* see if any background processes have exited */
1684 checkjobs(&job_list);
1686 if (!next_command) {
1687 if (get_command(input, command))
1689 next_command = command;
1692 if (expand_arguments(next_command) == FALSE) {
1694 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1695 next_command = NULL;
1699 if (!parse_command(&next_command, &newjob, &inbg) &&
1701 int pipefds[2] = {-1,-1};
1702 debug_printf( "job=%p being fed to run_command by busy_loop()'\n", &newjob);
1703 run_command(&newjob, inbg, pipefds);
1707 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1708 next_command = NULL;
1711 /* a job is running in the foreground; wait for it */
1713 while (!job_list.fg->progs[i].pid ||
1714 job_list.fg->progs[i].is_stopped == 1) i++;
1716 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0)
1717 perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1719 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1720 /* the child exited */
1721 job_list.fg->running_progs--;
1722 job_list.fg->progs[i].pid = 0;
1724 #ifdef BB_FEATURE_SH_ENVIRONMENT
1725 last_return_code=WEXITSTATUS(status);
1726 debug_printf("'%s' exited -- return code %d\n",
1727 job_list.fg->text, last_return_code);
1729 if (!job_list.fg->running_progs) {
1731 remove_job(&job_list, job_list.fg);
1735 /* the child was stopped */
1736 job_list.fg->stopped_progs++;
1737 job_list.fg->progs[i].is_stopped = 1;
1739 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1740 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1741 "Stopped", job_list.fg->text);
1747 /* move the shell to the foreground */
1748 /* suppress messages when run from /linuxrc mag@sysgo.de */
1749 if (tcsetpgrp(0, getpid()) && errno != ENOTTY)
1750 perror_msg("tcsetpgrp");
1756 /* return controlling TTY back to parent process group before exiting */
1757 if (tcsetpgrp(0, parent_pgrp))
1758 perror_msg("tcsetpgrp");
1760 /* return exit status if called with "-c" */
1761 if (input == NULL && WIFEXITED(status))
1762 return WEXITSTATUS(status);
1768 #ifdef BB_FEATURE_CLEAN_UP
1769 void free_memory(void)
1773 if (local_pending_command)
1774 free(local_pending_command);
1776 if (job_list.fg && !job_list.fg->running_progs) {
1777 remove_job(&job_list, job_list.fg);
1783 int shell_main(int argc_l, char **argv_l)
1785 int opt, interactive=FALSE;
1786 FILE *input = stdin;
1790 /* These variables need re-initializing when recursing */
1793 local_pending_command = NULL;
1794 close_me_head = NULL;
1795 job_list.head = NULL;
1797 #ifdef BB_FEATURE_SH_ENVIRONMENT
1803 if (argv[0] && argv[0][0] == '-') {
1805 prof_input = fopen("/etc/profile", "r");
1807 printf( "Couldn't open file '/etc/profile'\n");
1809 int tmp_fd = fileno(prof_input);
1811 /* Now run the file */
1812 busy_loop(prof_input);
1814 mark_closed(tmp_fd);
1818 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1822 if (local_pending_command != 0)
1823 error_msg_and_die("multiple -c arguments");
1824 local_pending_command = xstrdup(argv[optind]);
1828 #ifdef BB_FEATURE_SH_ENVIRONMENT
1830 show_x_trace = TRUE;
1840 /* A shell is interactive if the `-i' flag was given, or if all of
1841 * the following conditions are met:
1843 * no arguments remaining or the -s flag given
1844 * standard input is a terminal
1845 * standard output is a terminal
1846 * Refer to Posix.2, the description of the `sh' utility. */
1847 if (argv[optind]==NULL && input==stdin &&
1848 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
1851 if (interactive==TRUE) {
1852 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1853 /* Looks like they want an interactive shell */
1854 printf( "\n\nBusyBox v%s (%s) Built-in shell (lash)\n", BB_VER, BB_BT);
1855 printf( "Enter 'help' for a list of built-in commands.\n\n");
1856 } else if (local_pending_command==NULL) {
1857 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1858 input = xfopen(argv[optind], "r");
1859 mark_open(fileno(input)); /* be lazy, never mark this closed */
1862 /* initialize the cwd -- this is never freed...*/
1863 cwd=(char*)xmalloc(sizeof(char)*MAX_LINE+1);
1864 getcwd(cwd, sizeof(char)*MAX_LINE);
1866 #ifdef BB_FEATURE_CLEAN_UP
1867 atexit(free_memory);
1870 return (busy_loop(input));