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 -- sortof...
43 #define BB_FEATURE_SH_IF_EXPRESSIONS
45 /* This is currently sortof broken, only for the brave... */
46 #undef HANDLE_CONTINUATION_CHARS
48 /* This would be great -- if wordexp wouldn't strip all quoting
49 * out from the target strings... As is, a parser needs */
50 #undef BB_FEATURE_SH_WORDEXP
52 //For debugging/development on the shell only...
63 #include <sys/ioctl.h>
70 #ifdef BB_LOCALE_SUPPORT
74 //#define BB_FEATURE_SH_WORDEXP
76 #ifdef BB_FEATURE_SH_WORDEXP
78 #define expand_t wordexp_t
79 #undef BB_FEATURE_SH_BACKTICKS
82 #define expand_t glob_t
86 static const int MAX_READ = 128; /* size of input buffer for `read' builtin */
87 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
90 enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
94 static const unsigned int DEFAULT_CONTEXT=0x1;
95 static const unsigned int IF_TRUE_CONTEXT=0x2;
96 static const unsigned int IF_FALSE_CONTEXT=0x4;
97 static const unsigned int THEN_EXP_CONTEXT=0x8;
98 static const unsigned int ELSE_EXP_CONTEXT=0x10;
102 struct job *head; /* head of list of running jobs */
103 struct job *fg; /* current foreground job */
106 struct redir_struct {
107 enum redir_type type; /* type of redirection */
108 int fd; /* file descriptor being redirected */
109 char *filename; /* file to redirect fd to */
113 pid_t pid; /* 0 if exited */
114 char **argv; /* program name and arguments */
115 int num_redirects; /* elements in redirection array */
116 struct redir_struct *redirects; /* I/O redirects */
117 int is_stopped; /* is the program currently running? */
118 struct job *family; /* pointer back to the child's parent job */
122 int jobid; /* job number */
123 int num_progs; /* total number of programs in job */
124 int running_progs; /* number of programs running */
125 char *text; /* name of job */
126 char *cmdbuf; /* buffer various argv's point into */
127 pid_t pgrp; /* process group ID for the job */
128 struct child_prog *progs; /* array of programs in job */
129 struct job *next; /* to track background commands */
130 int stopped_progs; /* number of programs alive, but stopped */
131 unsigned int job_context; /* bitmask defining current context */
132 struct jobset *job_list;
135 struct built_in_command {
136 char *cmd; /* name */
137 char *descr; /* description */
138 int (*function) (struct child_prog *); /* function ptr */
143 struct close_me *next;
146 /* function prototypes for builtins */
147 static int builtin_cd(struct child_prog *cmd);
148 static int builtin_exec(struct child_prog *cmd);
149 static int builtin_exit(struct child_prog *cmd);
150 static int builtin_fg_bg(struct child_prog *cmd);
151 static int builtin_help(struct child_prog *cmd);
152 static int builtin_jobs(struct child_prog *dummy);
153 static int builtin_pwd(struct child_prog *dummy);
154 static int builtin_export(struct child_prog *cmd);
155 static int builtin_source(struct child_prog *cmd);
156 static int builtin_unset(struct child_prog *cmd);
157 static int builtin_read(struct child_prog *cmd);
158 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
159 static int builtin_if(struct child_prog *cmd);
160 static int builtin_then(struct child_prog *cmd);
161 static int builtin_else(struct child_prog *cmd);
162 static int builtin_fi(struct child_prog *cmd);
163 /* function prototypes for shell stuff */
164 static int run_command_predicate(char *cmd);
168 /* function prototypes for shell stuff */
169 static void mark_open(int fd);
170 static void mark_closed(int fd);
171 static void close_all(void);
172 static void checkjobs(struct jobset *job_list);
173 static int get_command(FILE * source, char *command);
174 static int parse_command(char **command_ptr, struct job *job, int *inbg);
175 static int run_command(struct job *newjob, int inbg, int outpipe[2]);
176 static int pseudo_exec(struct child_prog *cmd) __attribute__ ((noreturn));
177 static int busy_loop(FILE * input);
180 /* Table of built-in functions (these are non-forking builtins, meaning they
181 * can change global variables in the parent shell process but they will not
182 * work with pipes and redirects; 'unset foo | whatever' will not work) */
183 static struct built_in_command bltins[] = {
184 {"bg", "Resume a job in the background", builtin_fg_bg},
185 {"cd", "Change working directory", builtin_cd},
186 {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
187 {"exit", "Exit from shell()", builtin_exit},
188 {"fg", "Bring job into the foreground", builtin_fg_bg},
189 {"jobs", "Lists the active jobs", builtin_jobs},
190 {"export", "Set environment variable", builtin_export},
191 {"unset", "Unset environment variable", builtin_unset},
192 {"read", "Input environment variable", builtin_read},
193 {".", "Source-in and run commands in a file", builtin_source},
194 /* to do: add ulimit */
195 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
196 {"if", NULL, builtin_if},
197 {"then", NULL, builtin_then},
198 {"else", NULL, builtin_else},
199 {"fi", NULL, builtin_fi},
204 /* Table of forking built-in functions (things that fork cannot change global
205 * variables in the parent process, such as the current working directory) */
206 static struct built_in_command bltins_forking[] = {
207 {"pwd", "Print current directory", builtin_pwd},
208 {"help", "List shell built-in commands", builtin_help},
213 /* Variables we export */
214 unsigned int shell_context; /* Used in cmdedit.c to reset the
215 context when someone hits ^C */
218 /* Globals that are static to this file */
219 static const char *cwd;
220 static char *local_pending_command = NULL;
221 static struct jobset job_list = { NULL, NULL };
224 static struct close_me *close_me_head;
225 #ifdef BB_FEATURE_SH_ENVIRONMENT
226 static int last_bg_pid;
227 static int last_return_code;
228 static int show_x_trace;
230 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
231 static char syntax_err[]="syntax error near unexpected token";
235 static char *PS2 = "> ";
239 static inline void debug_printf(const char *format, ...)
242 va_start(args, format);
243 vfprintf(stderr, format, args);
247 static inline void debug_printf(const char *format, ...) { }
251 Most builtins need access to the struct child_prog that has
252 their arguments, previously coded as cmd->progs[0]. That coding
253 can exhibit a bug, if the builtin is not the first command in
254 a pipeline: "echo foo | exec sort" will attempt to exec foo.
256 builtin previous use notes
257 ------ ----------------- ---------
259 exec cmd->progs[0] squashed bug: didn't look for applets or forking builtins
261 fg_bg cmd->progs[0], job_list->head, job_list->fg
269 if cmd->job_context, cmd->text
270 then cmd->job_context, cmd->text
271 else cmd->job_context, cmd->text
274 The use of cmd->text by if/then/else/fi is hopelessly hacky.
275 Would it work to increment cmd->progs[0]->argv and recurse,
276 somewhat like builtin_exec does?
278 I added "struct job *family;" to struct child_prog,
279 and switched API to builtin_foo(struct child_prog *child);
280 So cmd->text becomes child->family->text
281 cmd->job_context becomes child->family->job_context
282 cmd->progs[0] becomes *child
283 job_list becomes child->family->job_list
286 /* built-in 'cd <path>' handler */
287 static int builtin_cd(struct child_prog *child)
291 if (child->argv[1] == NULL)
292 newdir = getenv("HOME");
294 newdir = child->argv[1];
296 printf("cd: %s: %m\n", newdir);
299 cwd = xgetcwd((char *)cwd);
305 /* built-in 'exec' handler */
306 static int builtin_exec(struct child_prog *child)
308 if (child->argv[1] == NULL)
309 return EXIT_SUCCESS; /* Really? */
316 /* built-in 'exit' handler */
317 static int builtin_exit(struct child_prog *child)
319 if (child->argv[1] == NULL)
322 exit (atoi(child->argv[1]));
325 /* built-in 'fg' and 'bg' handler */
326 static int builtin_fg_bg(struct child_prog *child)
329 struct job *job=NULL;
331 if (!child->argv[1] || child->argv[2]) {
332 error_msg("%s: exactly one argument is expected",
337 if (sscanf(child->argv[1], "%%%d", &jobNum) != 1) {
338 error_msg("%s: bad argument '%s'",
339 child->argv[0], child->argv[1]);
343 for (job = child->family->job_list->head; job; job = job->next) {
344 if (job->jobid == jobNum) {
350 error_msg("%s: unknown job %d",
351 child->argv[0], jobNum);
355 if (*child->argv[0] == 'f') {
356 /* Make this job the foreground job */
357 /* suppress messages when run from /linuxrc mag@sysgo.de */
358 if (tcsetpgrp(0, job->pgrp) && errno != ENOTTY)
359 perror_msg("tcsetpgrp");
360 child->family->job_list->fg = job;
363 /* Restart the processes in the job */
364 for (i = 0; i < job->num_progs; i++)
365 job->progs[i].is_stopped = 0;
367 kill(-job->pgrp, SIGCONT);
369 job->stopped_progs = 0;
374 /* built-in 'help' handler */
375 static int builtin_help(struct child_prog *dummy)
377 struct built_in_command *x;
379 printf("\nBuilt-in commands:\n");
380 printf("-------------------\n");
381 for (x = bltins; x->cmd; x++) {
384 printf("%s\t%s\n", x->cmd, x->descr);
386 for (x = bltins_forking; x->cmd; x++) {
389 printf("%s\t%s\n", x->cmd, x->descr);
395 /* built-in 'jobs' handler */
396 static int builtin_jobs(struct child_prog *child)
401 for (job = child->family->job_list->head; job; job = job->next) {
402 if (job->running_progs == job->stopped_progs)
403 status_string = "Stopped";
405 status_string = "Running";
407 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
413 /* built-in 'pwd' handler */
414 static int builtin_pwd(struct child_prog *dummy)
416 cwd = xgetcwd((char *)cwd);
423 /* built-in 'export VAR=value' handler */
424 static int builtin_export(struct child_prog *child)
427 char *v = child->argv[1];
431 for (e = environ; *e; e++) {
438 fprintf(stderr, "export: %m\n");
439 #ifdef BB_FEATURE_SH_FANCY_PROMPT
440 if (strncmp(v, "PS1=", 4)==0)
444 #ifdef BB_LOCALE_SUPPORT
445 if(strncmp(v, "LC_ALL=", 7)==0)
446 setlocale(LC_ALL, getenv("LC_ALL"));
447 if(strncmp(v, "LC_CTYPE=", 9)==0)
448 setlocale(LC_CTYPE, getenv("LC_CTYPE"));
454 /* built-in 'read VAR' handler */
455 static int builtin_read(struct child_prog *child)
457 int res = 0, len, newlen;
459 char string[MAX_READ];
461 if (child->argv[1]) {
462 /* argument (VAR) given: put "VAR=" into buffer */
463 strcpy(string, child->argv[1]);
464 len = strlen(string);
467 fgets(&string[len], sizeof(string) - len, stdin); /* read string */
468 newlen = strlen(string);
470 string[--newlen] = '\0'; /* chomp trailing newline */
472 ** string should now contain "VAR=<value>"
473 ** copy it (putenv() won't do that, so we must make sure
474 ** the string resides in a static buffer!)
477 if((s = strdup(string)))
480 fprintf(stderr, "read: %m\n");
483 fgets(string, sizeof(string), stdin);
488 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
489 /* Built-in handler for 'if' commands */
490 static int builtin_if(struct child_prog *child)
492 struct job *cmd = child->family;
494 char* charptr1=cmd->text+3; /* skip over the leading 'if ' */
496 /* Now run the 'if' command */
497 debug_printf( "job=%p entering builtin_if ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
498 status = run_command_predicate(charptr1);
499 debug_printf( "if test returned ");
501 debug_printf( "TRUE\n");
502 cmd->job_context |= IF_TRUE_CONTEXT;
504 debug_printf( "FALSE\n");
505 cmd->job_context |= IF_FALSE_CONTEXT;
507 debug_printf("job=%p builtin_if set job context to %x\n", cmd, cmd->job_context);
513 /* Built-in handler for 'then' (part of the 'if' command) */
514 static int builtin_then(struct child_prog *child)
516 struct job *cmd = child->family;
517 char* charptr1=cmd->text+5; /* skip over the leading 'then ' */
519 debug_printf( "job=%p entering builtin_then ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
520 if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
521 shell_context = 0; /* Reset the shell's context on an error */
522 error_msg("%s `then'", syntax_err);
526 cmd->job_context |= THEN_EXP_CONTEXT;
527 debug_printf("job=%p builtin_then set job context to %x\n", cmd, cmd->job_context);
529 /* If the if result was FALSE, skip the 'then' stuff */
530 if (cmd->job_context & IF_FALSE_CONTEXT) {
534 /* Seems the if result was TRUE, so run the 'then' command */
535 debug_printf( "'then' now running '%s'\n", charptr1);
537 return(run_command_predicate(charptr1));
540 /* Built-in handler for 'else' (part of the 'if' command) */
541 static int builtin_else(struct child_prog *child)
543 struct job *cmd = child->family;
544 char* charptr1=cmd->text+5; /* skip over the leading 'else ' */
546 debug_printf( "job=%p entering builtin_else ('%s')-- context=%d\n", cmd, charptr1, cmd->job_context);
548 if (! (cmd->job_context & THEN_EXP_CONTEXT)) {
549 shell_context = 0; /* Reset the shell's context on an error */
550 error_msg("%s `else'", syntax_err);
553 /* If the if result was TRUE, skip the 'else' stuff */
554 if (cmd->job_context & IF_TRUE_CONTEXT) {
558 cmd->job_context |= ELSE_EXP_CONTEXT;
559 debug_printf("job=%p builtin_else set job context to %x\n", cmd, cmd->job_context);
561 /* Now run the 'else' command */
562 debug_printf( "'else' now running '%s'\n", charptr1);
563 return(run_command_predicate(charptr1));
566 /* Built-in handler for 'fi' (part of the 'if' command) */
567 static int builtin_fi(struct child_prog *child)
569 struct job *cmd = child->family;
570 debug_printf( "job=%p entering builtin_fi ('%s')-- context=%d\n", cmd, "", cmd->job_context);
571 if (! (cmd->job_context & (IF_TRUE_CONTEXT|IF_FALSE_CONTEXT))) {
572 shell_context = 0; /* Reset the shell's context on an error */
573 error_msg("%s `fi'", syntax_err);
576 /* Clear out the if and then context bits */
577 cmd->job_context &= ~(IF_TRUE_CONTEXT|IF_FALSE_CONTEXT|THEN_EXP_CONTEXT|ELSE_EXP_CONTEXT);
578 debug_printf("job=%p builtin_fi set job context to %x\n", cmd, cmd->job_context);
584 /* Built-in '.' handler (read-in and execute commands from file) */
585 static int builtin_source(struct child_prog *child)
591 if (child->argv[1] == NULL)
594 input = fopen(child->argv[1], "r");
596 printf( "Couldn't open file '%s'\n", child->argv[1]);
602 /* Now run the file */
603 status = busy_loop(input);
609 /* built-in 'unset VAR' handler */
610 static int builtin_unset(struct child_prog *child)
612 if (child->argv[1] == NULL) {
613 printf( "unset: parameter required.\n");
616 unsetenv(child->argv[1]);
620 #ifdef BB_FEATURE_SH_IF_EXPRESSIONS
621 /* currently used by if/then/else.
623 * Reparsing the command line for this purpose is gross,
624 * incorrect, and fundamentally unfixable; in particular,
625 * think about what happens with command substitution.
626 * We really need to pull out the run, wait, return status
627 * functionality out of busy_loop so we can child->argv++
628 * and use that, without going back through parse_command.
630 static int run_command_predicate(char *cmd)
632 local_pending_command = xstrdup(cmd);
633 return( busy_loop(NULL));
637 static void mark_open(int fd)
639 struct close_me *new = xmalloc(sizeof(struct close_me));
641 new->next = close_me_head;
645 static void mark_closed(int fd)
647 struct close_me *tmp;
648 if (close_me_head == NULL || close_me_head->fd != fd)
649 error_msg_and_die("corrupt close_me");
651 close_me_head = close_me_head->next;
655 static void close_all()
657 struct close_me *c, *tmp;
658 for (c=close_me_head; c; c=tmp) {
663 close_me_head = NULL;
667 /* free up all memory from a job */
668 static void free_job(struct job *cmd)
673 for (i = 0; i < cmd->num_progs; i++) {
674 free(cmd->progs[i].argv);
675 if (cmd->progs[i].redirects)
676 free(cmd->progs[i].redirects);
684 keep = cmd->job_list;
685 memset(cmd, 0, sizeof(struct job));
686 cmd->job_list = keep;
689 /* remove a job from a jobset */
690 static void remove_job(struct jobset *j_list, struct job *job)
695 if (job == j_list->head) {
696 j_list->head = job->next;
698 prevjob = j_list->head;
699 while (prevjob->next != job)
700 prevjob = prevjob->next;
701 prevjob->next = job->next;
707 /* Checks to see if any background processes have exited -- if they
708 have, figure out why and see if a job has completed */
709 static void checkjobs(struct jobset *j_list)
716 while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
717 for (job = j_list->head; job; job = job->next) {
719 while (prognum < job->num_progs &&
720 job->progs[prognum].pid != childpid) prognum++;
721 if (prognum < job->num_progs)
725 /* This happens on backticked commands */
729 if (WIFEXITED(status) || WIFSIGNALED(status)) {
731 job->running_progs--;
732 job->progs[prognum].pid = 0;
734 if (!job->running_progs) {
735 printf(JOB_STATUS_FORMAT, job->jobid, "Done", job->text);
736 remove_job(j_list, job);
740 job->stopped_progs++;
741 job->progs[prognum].is_stopped = 1;
743 if (job->stopped_progs == job->num_progs) {
744 printf(JOB_STATUS_FORMAT, job->jobid, "Stopped",
750 if (childpid == -1 && errno != ECHILD)
751 perror_msg("waitpid");
754 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
755 * and stderr if they are redirected. */
756 static int setup_redirects(struct child_prog *prog, int squirrel[])
761 struct redir_struct *redir = prog->redirects;
763 for (i = 0; i < prog->num_redirects; i++, redir++) {
764 switch (redir->type) {
768 case REDIRECT_OVERWRITE:
769 mode = O_WRONLY | O_CREAT | O_TRUNC;
771 case REDIRECT_APPEND:
772 mode = O_WRONLY | O_CREAT | O_APPEND;
776 openfd = open(redir->filename, mode, 0666);
778 /* this could get lost if stderr has been redirected, but
779 bash and ash both lose it as well (though zsh doesn't!) */
780 perror_msg("error opening %s", redir->filename);
784 if (openfd != redir->fd) {
785 if (squirrel && redir->fd < 3) {
786 squirrel[redir->fd] = dup(redir->fd);
788 dup2(openfd, redir->fd);
796 static void restore_redirects(int squirrel[])
799 for (i=0; i<3; i++) {
802 /* No error checking. I sure wouldn't know what
803 * to do with an error if I found one! */
810 static inline void cmdedit_set_initial_prompt(void)
812 #ifndef BB_FEATURE_SH_FANCY_PROMPT
821 static inline void setup_prompt_string(char **prompt_str)
823 #ifndef BB_FEATURE_SH_FANCY_PROMPT
824 /* Set up the prompt */
825 if (shell_context == 0) {
828 PS1=xmalloc(strlen(cwd)+4);
829 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
835 *prompt_str = (shell_context==0)? PS1 : PS2;
839 static int get_command(FILE * source, char *command)
843 if (source == NULL) {
844 if (local_pending_command) {
845 /* a command specified (-c option): return it & mark it done */
846 strcpy(command, local_pending_command);
847 free(local_pending_command);
848 local_pending_command = NULL;
854 if (source == stdin) {
855 setup_prompt_string(&prompt_str);
857 #ifdef BB_FEATURE_COMMAND_EDITING
859 ** enable command line editing only while a command line
860 ** is actually being read; otherwise, we'll end up bequeathing
861 ** atexit() handlers and other unwanted stuff to our
862 ** child processes (rob@sysgo.de)
864 cmdedit_read_input(prompt_str, command);
868 fputs(prompt_str, stdout);
872 if (!fgets(command, BUFSIZ - 2, source)) {
881 #ifdef BB_FEATURE_SH_ENVIRONMENT
882 static char* itoa(register int i)
884 static char a[7]; /* Max 7 ints */
885 register char *b = a + sizeof(a) - 1;
893 *--b = '0' + (i % 10);
903 #if defined BB_FEATURE_SH_ENVIRONMENT && ! defined BB_FEATURE_SH_WORDEXP
904 char * strsep_space( char *string, int * ix)
910 /* Short circuit the trivial case */
911 if ( !string || ! string[*ix])
914 /* Find the end of the token. */
915 while( string && string[*ix] && !isspace(string[*ix]) ) {
919 /* Find the end of any whitespace trailing behind
920 * the token and let that be part of the token */
921 while( string && string[*ix] && isspace(string[*ix]) ) {
925 if (! string && *ix==0) {
926 /* Nothing useful was found */
930 token = xmalloc(*ix+1);
932 strncpy(token, string, *ix);
939 static int expand_arguments(char *command)
941 #ifdef BB_FEATURE_SH_ENVIRONMENT
942 expand_t expand_result;
943 char *src, *dst, *var;
945 int i=0, length, total_length=0, retval;
946 const char *out_of_space = "out of space during expansion";
949 /* get rid of the terminating \n */
952 /* Fix up escape sequences to be the Real Thing(tm) */
953 while( command && command[ix]) {
954 if (command[ix] == '\\') {
955 const char *tmp = command+ix+1;
956 command[ix] = process_escape_sequence( &tmp );
957 memmove(command+ix + 1, tmp, strlen(tmp)+1);
962 #ifdef BB_FEATURE_SH_ENVIRONMENT
965 #ifdef BB_FEATURE_SH_WORDEXP
966 /* This first part uses wordexp() which is a wonderful C lib
967 * function which expands nearly everything. */
968 retval = wordexp (command, &expand_result, WRDE_SHOWERR);
969 if (retval == WRDE_NOSPACE) {
970 /* Mem may have been allocated... */
971 wordfree (&expand_result);
972 error_msg(out_of_space);
976 /* Some other error. */
977 error_msg("syntax error");
981 if (expand_result.we_wordc > 0) {
982 /* Convert from char** (one word per string) to a simple char*,
983 * but don't overflow command which is BUFSIZ in length */
985 while (i < expand_result.we_wordc && total_length < BUFSIZ) {
986 length=strlen(expand_result.we_wordv[i])+1;
987 if (BUFSIZ-total_length-length <= 0) {
988 error_msg(out_of_space);
991 strcat(command+total_length, expand_result.we_wordv[i++]);
992 strcat(command+total_length, " ");
993 total_length+=length;
995 wordfree (&expand_result);
999 /* Ok. They don't have a recent glibc and they don't have uClibc. Chances
1000 * are about 100% they don't have wordexp(). So instead the best we can do
1001 * is use glob and then fixup environment variables and such ourselves.
1002 * This is better then nothing, but certainly not perfect */
1004 /* It turns out that glob is very stupid. We have to feed it one word at a
1005 * time since it can't cope with a full string. Here we convert command
1006 * (char*) into cmd (char**, one word per string) */
1009 int flags = GLOB_NOCHECK
1017 char *tmpcmd, *cmd, *cmd_copy;
1018 /* We need a clean copy, so strsep can mess up the copy while
1019 * we write stuff into the original (in a minute) */
1020 cmd = cmd_copy = strdup(command);
1022 for (ix = 0, tmpcmd = cmd;
1023 (tmpcmd = strsep_space(cmd, &ix)) != NULL; cmd += ix, ix=0) {
1024 if (*tmpcmd == '\0')
1026 /* we need to trim() the result for glob! */
1028 retval = glob(tmpcmd, flags, NULL, &expand_result);
1029 free(tmpcmd); /* Free mem allocated by strsep_space */
1030 if (retval == GLOB_NOSPACE) {
1031 /* Mem may have been allocated... */
1032 globfree (&expand_result);
1033 error_msg(out_of_space);
1035 } else if (retval != 0) {
1036 /* Some other error. GLOB_NOMATCH shouldn't
1037 * happen because of the GLOB_NOCHECK flag in
1039 error_msg("syntax error");
1042 /* Convert from char** (one word per string) to a simple char*,
1043 * but don't overflow command which is BUFSIZ in length */
1044 for (i=0; i < expand_result.gl_pathc; i++) {
1045 length=strlen(expand_result.gl_pathv[i]);
1046 if (total_length+length+1 >= BUFSIZ) {
1047 error_msg(out_of_space);
1050 strcat(command+total_length, " ");
1052 strcat(command+total_length, expand_result.gl_pathv[i]);
1053 total_length+=length;
1055 globfree (&expand_result);
1064 /* Now do the shell variable substitutions which
1065 * wordexp can't do for us, namely $? and $! */
1067 while((dst = strchr(src,'$')) != NULL){
1071 var = itoa(last_return_code);
1074 if (last_bg_pid==-1)
1077 var = itoa(last_bg_pid);
1079 /* Everything else like $$, $#, $[0-9], etc should all be
1080 * expanded by wordexp(), so we can in theory skip that stuff
1081 * here, but just to be on the safe side (i.e. since uClibc
1082 * wordexp doesn't do this stuff yet), lets leave it in for
1085 var = itoa(getpid());
1090 case '0':case '1':case '2':case '3':case '4':
1091 case '5':case '6':case '7':case '8':case '9':
1093 int ixx=*(dst + 1)-48;
1104 /* a single character construction was found, and
1105 * already handled in the case statement */
1108 /* Looks like an environment variable */
1110 int num_skip_chars=0;
1111 int dstlen = strlen(dst);
1112 /* Is this a ${foo} type variable? */
1113 if (dstlen >=2 && *(dst+1) == '{') {
1114 src=strchr(dst+1, '}');
1118 while(isalnum(*src) || *src=='_') src++;
1124 *src='\0'; /* temporary */
1125 var = getenv(dst + 1 + num_skip_chars);
1127 src += num_skip_chars;
1130 /* Seems we got an un-expandable variable. So delete it. */
1134 int subst_len = strlen(var);
1135 int trail_len = strlen(src);
1136 if (dst+subst_len+trail_len >= command+BUFSIZ) {
1137 error_msg(out_of_space);
1140 /* Move stuff to the end of the string to accommodate
1141 * filling the created gap with the new stuff */
1142 memmove(dst+subst_len, src, trail_len+1);
1143 /* Now copy in the new stuff */
1144 memcpy(dst, var, subst_len);
1145 src = dst+subst_len;
1153 /* Return cmd->num_progs as 0 if no command is present (e.g. an empty
1154 line). If a valid command is found, command_ptr is set to point to
1155 the beginning of the next command (if the original command had more
1156 then one job associated with it) or NULL if no more commands are
1158 static int parse_command(char **command_ptr, struct job *job, int *inbg)
1161 char *return_command = NULL;
1162 char *src, *buf, *chptr;
1166 int i, saw_quote = 0;
1169 struct child_prog *prog;
1171 /* skip leading white space */
1172 while (**command_ptr && isspace(**command_ptr))
1175 /* this handles empty lines or leading '#' characters */
1176 if (!**command_ptr || (**command_ptr == '#')) {
1183 job->progs = xmalloc(sizeof(*job->progs));
1185 /* We set the argv elements to point inside of this string. The
1186 memory is freed by free_job(). Allocate twice the original
1187 length in case we need to quote every single character.
1189 Getting clean memory relieves us of the task of NULL
1190 terminating things and makes the rest of this look a bit
1191 cleaner (though it is, admittedly, a tad less efficient) */
1192 job->cmdbuf = command = xcalloc(2*strlen(*command_ptr) + 1, sizeof(char));
1196 prog->num_redirects = 0;
1197 prog->redirects = NULL;
1198 prog->is_stopped = 0;
1202 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1203 prog->argv[0] = job->cmdbuf;
1207 while (*src && !done) {
1208 if (quote == *src) {
1214 error_msg("character expected after \\");
1219 /* in shell, "\'" should yield \' */
1220 if (*src != quote) {
1224 } else if (*src == '*' || *src == '?' || *src == '[' ||
1225 *src == ']') *buf++ = '\\';
1227 } else if (isspace(*src)) {
1228 if (*prog->argv[argc_l] || saw_quote) {
1230 /* +1 here leaves room for the NULL which ends argv */
1231 if ((argc_l + 1) == argv_alloced) {
1233 prog->argv = xrealloc(prog->argv,
1234 sizeof(*prog->argv) *
1237 prog->argv[argc_l] = buf;
1248 case '#': /* comment */
1255 case '>': /* redirects */
1257 i = prog->num_redirects++;
1258 prog->redirects = xrealloc(prog->redirects,
1259 sizeof(*prog->redirects) *
1262 prog->redirects[i].fd = -1;
1263 if (buf != prog->argv[argc_l]) {
1264 /* the stuff before this character may be the file number
1266 prog->redirects[i].fd =
1267 strtol(prog->argv[argc_l], &chptr, 10);
1269 if (*chptr && *prog->argv[argc_l]) {
1271 prog->argv[argc_l] = buf;
1275 if (prog->redirects[i].fd == -1) {
1277 prog->redirects[i].fd = 1;
1279 prog->redirects[i].fd = 0;
1282 if (*src++ == '>') {
1284 prog->redirects[i].type =
1285 REDIRECT_APPEND, src++;
1287 prog->redirects[i].type = REDIRECT_OVERWRITE;
1289 prog->redirects[i].type = REDIRECT_INPUT;
1292 /* This isn't POSIX sh compliant. Oh well. */
1294 while (isspace(*chptr))
1298 error_msg("file name expected after %c", *(src-1));
1304 prog->redirects[i].filename = buf;
1305 while (*chptr && !isspace(*chptr))
1308 src = chptr - 1; /* we src++ later */
1309 prog->argv[argc_l] = ++buf;
1312 case '|': /* pipe */
1313 /* finish this command */
1314 if (*prog->argv[argc_l] || saw_quote)
1317 error_msg("empty command in pipe");
1322 prog->argv[argc_l] = NULL;
1324 /* and start the next */
1326 job->progs = xrealloc(job->progs,
1327 sizeof(*job->progs) * job->num_progs);
1328 prog = job->progs + (job->num_progs - 1);
1329 prog->num_redirects = 0;
1330 prog->redirects = NULL;
1331 prog->is_stopped = 0;
1336 prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
1337 prog->argv[0] = ++buf;
1340 while (*src && isspace(*src))
1344 error_msg("empty command in pipe");
1349 src--; /* we'll ++ it at the end of the loop */
1353 case '&': /* background */
1355 case ';': /* multiple commands */
1357 return_command = *command_ptr + (src - *command_ptr) + 1;
1360 #ifdef BB_FEATURE_SH_BACKTICKS
1362 /* Exec a backtick-ed command */
1363 /* Besides any previous brokenness, I have not
1364 * updated backtick handling for close_me support.
1365 * I don't know if it needs it or not. -- LRD */
1367 char* charptr1=NULL, *charptr2;
1370 struct jobset njob_list = { NULL, NULL };
1374 ptr=strchr(++src, '`');
1376 fprintf(stderr, "Unmatched '`' in command\n");
1381 /* Make some space to hold just the backticked command */
1382 charptr1 = charptr2 = xmalloc(1+ptr-src);
1383 memcpy(charptr1, src, ptr-src);
1384 charptr1[ptr-src] = '\0';
1385 newjob = xmalloc(sizeof(struct job));
1386 newjob->job_list = &njob_list;
1387 /* Now parse and run the backticked command */
1388 if (!parse_command(&charptr1, newjob, inbg)
1389 && newjob->num_progs) {
1391 run_command(newjob, 0, pipefd);
1393 checkjobs(job->job_list);
1394 free_job(newjob); /* doesn't actually free newjob,
1395 looks like a memory leak */
1398 /* Make a copy of any stuff left over in the command
1399 * line after the second backtick */
1400 charptr2 = xmalloc(strlen(ptr)+1);
1401 memcpy(charptr2, ptr+1, strlen(ptr));
1404 /* Copy the output from the backtick-ed command into the
1405 * command line, making extra room as needed */
1407 charptr1 = xmalloc(BUFSIZ);
1408 while ( (size=full_read(pipefd[0], charptr1, BUFSIZ-1)) >0) {
1409 int newsize=src - *command_ptr + size + 1 + strlen(charptr2);
1410 if (newsize > BUFSIZ) {
1411 *command_ptr=xrealloc(*command_ptr, newsize);
1413 memcpy(src, charptr1, size);
1421 /* Now paste into the *command_ptr all the stuff
1422 * leftover after the second backtick */
1423 memcpy(src, charptr2, strlen(charptr2)+1);
1426 /* Now recursively call parse_command to deal with the new
1427 * and improved version of the command line with the backtick
1428 * results expanded in place... */
1430 struct jobset *jl=job->job_list;
1434 return(parse_command(command_ptr, job, inbg));
1437 #endif // BB_FEATURE_SH_BACKTICKS
1442 /* This is currently a little broken... */
1443 #ifdef HANDLE_CONTINUATION_CHARS
1444 /* They fed us a continuation char, so continue reading stuff
1445 * on the next line, then tack that onto the end of the current
1449 printf("erik: found a continue char at EOL...\n");
1450 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1451 if (get_command(input, command)) {
1452 error_msg("character expected after \\");
1457 newsize = strlen(*command_ptr) + strlen(command) + 2;
1458 if (newsize > BUFSIZ) {
1459 printf("erik: doing realloc\n");
1460 *command_ptr=xrealloc(*command_ptr, newsize);
1462 printf("erik: A: *command_ptr='%s'\n", *command_ptr);
1463 memcpy(--src, command, strlen(command));
1464 printf("erik: B: *command_ptr='%s'\n", *command_ptr);
1468 error_msg("character expected after \\");
1473 if (*src == '*' || *src == '[' || *src == ']'
1474 || *src == '?') *buf++ = '\\';
1483 if (*prog->argv[argc_l] || saw_quote) {
1490 prog->argv[argc_l] = NULL;
1492 if (!return_command) {
1493 job->text = xmalloc(strlen(*command_ptr) + 1);
1494 strcpy(job->text, *command_ptr);
1496 /* This leaves any trailing spaces, which is a bit sloppy */
1497 count = return_command - *command_ptr;
1498 job->text = xmalloc(count + 1);
1499 strncpy(job->text, *command_ptr, count);
1500 job->text[count] = '\0';
1503 *command_ptr = return_command;
1508 /* Run the child_prog, no matter what kind of command it uses.
1510 static int pseudo_exec(struct child_prog *child)
1512 struct built_in_command *x;
1513 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1517 /* Check if the command matches any of the non-forking builtins.
1518 * Depending on context, this might be redundant. But it's
1519 * easier to waste a few CPU cycles than it is to figure out
1520 * if this is one of those cases.
1522 for (x = bltins; x->cmd; x++) {
1523 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1524 exit(x->function(child));
1528 /* Check if the command matches any of the forking builtins. */
1529 for (x = bltins_forking; x->cmd; x++) {
1530 if (strcmp(child->argv[0], x->cmd) == 0) {
1532 exit (x->function(child));
1535 #ifdef BB_FEATURE_SH_STANDALONE_SHELL
1536 /* Check if the command matches any busybox internal
1537 * commands ("applets") here. Following discussions from
1538 * November 2000 on busybox@opensource.lineo.com, don't use
1539 * get_last_path_component(). This way explicit (with
1540 * slashes) filenames will never be interpreted as an
1541 * applet, just like with builtins. This way the user can
1542 * override an applet with an explicit filename reference.
1543 * The only downside to this change is that an explicit
1544 * /bin/foo invocation will fork and exec /bin/foo, even if
1545 * /bin/foo is a symlink to busybox.
1547 name = child->argv[0];
1549 #ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1550 /* If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then
1551 * if you run /bin/cat, it will use BusyBox cat even if
1552 * /bin/cat exists on the filesystem and is _not_ busybox.
1553 * Some systems want this, others do not. Choose wisely. :-)
1555 name = get_last_path_component(name);
1559 char** argv_l=child->argv;
1561 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1563 run_applet_by_name(name, argc_l, child->argv);
1567 execvp(child->argv[0], child->argv);
1568 perror_msg_and_die("%s", child->argv[0]);
1571 static void insert_job(struct job *newjob, int inbg)
1574 struct jobset *j_list=newjob->job_list;
1576 /* find the ID for thejob to use */
1578 for (thejob = j_list->head; thejob; thejob = thejob->next)
1579 if (thejob->jobid >= newjob->jobid)
1580 newjob->jobid = thejob->jobid + 1;
1582 /* add thejob to the list of running jobs */
1583 if (!j_list->head) {
1584 thejob = j_list->head = xmalloc(sizeof(*thejob));
1586 for (thejob = j_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1587 thejob->next = xmalloc(sizeof(*thejob));
1588 thejob = thejob->next;
1591 *thejob = *newjob; /* physically copy the struct job */
1592 thejob->next = NULL;
1593 thejob->running_progs = thejob->num_progs;
1594 thejob->stopped_progs = 0;
1597 /* we don't wait for background thejobs to return -- append it
1598 to the list of backgrounded thejobs and leave it alone */
1599 printf("[%d] %d\n", thejob->jobid,
1600 newjob->progs[newjob->num_progs - 1].pid);
1601 #ifdef BB_FEATURE_SH_ENVIRONMENT
1602 last_bg_pid=newjob->progs[newjob->num_progs - 1].pid;
1605 newjob->job_list->fg = thejob;
1607 /* move the new process group into the foreground */
1608 /* suppress messages when run from /linuxrc mag@sysgo.de */
1609 if (tcsetpgrp(0, newjob->pgrp) && errno != ENOTTY)
1610 perror_msg("tcsetpgrp");
1614 static int run_command(struct job *newjob, int inbg, int outpipe[2])
1616 /* struct job *thejob; */
1618 int nextin, nextout;
1619 int pipefds[2]; /* pipefd[0] is for reading */
1620 struct built_in_command *x;
1621 struct child_prog *child;
1623 nextin = 0, nextout = 1;
1624 for (i = 0; i < newjob->num_progs; i++) {
1625 child = & (newjob->progs[i]);
1627 if ((i + 1) < newjob->num_progs) {
1628 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1629 nextout = pipefds[1];
1631 if (outpipe[1]!=-1) {
1632 nextout = outpipe[1];
1638 #ifdef BB_FEATURE_SH_ENVIRONMENT
1639 if (show_x_trace==TRUE) {
1642 for (j = 0; child->argv[j]; j++) {
1644 fputs(child->argv[j], stderr);
1646 fputc('\n', stderr);
1650 /* Check if the command matches any non-forking builtins,
1651 * but only if this is a simple command.
1652 * Non-forking builtins within pipes have to fork anyway,
1653 * and are handled in pseudo_exec. "echo foo | read bar"
1654 * is doomed to failure, and doesn't work on bash, either.
1656 if (newjob->num_progs == 1) {
1657 for (x = bltins; x->cmd; x++) {
1658 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1659 int squirrel[] = {-1, -1, -1};
1661 setup_redirects(child, squirrel);
1662 rcode = x->function(child);
1663 restore_redirects(squirrel);
1669 if (!(child->pid = fork())) {
1670 signal(SIGTTOU, SIG_DFL);
1674 if (outpipe[1]!=-1) {
1684 dup2(nextout, 2); /* Really? */
1689 /* explicit redirects override pipes */
1690 setup_redirects(child,NULL);
1694 if (outpipe[1]!=-1) {
1698 /* put our child in the process group whose leader is the
1699 first process in this pipe */
1700 setpgid(child->pid, newjob->progs[0].pid);
1706 /* If there isn't another process, nextin is garbage
1707 but it doesn't matter */
1708 nextin = pipefds[0];
1711 newjob->pgrp = newjob->progs[0].pid;
1713 insert_job(newjob, inbg);
1718 static int busy_loop(FILE * input)
1721 char *next_command = NULL;
1727 newjob.job_list = &job_list;
1728 newjob.job_context = DEFAULT_CONTEXT;
1730 /* save current owner of TTY so we can restore it on exit */
1731 parent_pgrp = tcgetpgrp(0);
1733 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1735 /* don't pay any attention to this signal; it just confuses
1736 things and isn't really meant for shells anyway */
1737 signal(SIGTTOU, SIG_IGN);
1741 /* no job is in the foreground */
1743 /* see if any background processes have exited */
1744 checkjobs(&job_list);
1746 if (!next_command) {
1747 if (get_command(input, command))
1749 next_command = command;
1752 if (expand_arguments(next_command) == FALSE) {
1754 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1755 next_command = NULL;
1759 if (!parse_command(&next_command, &newjob, &inbg) &&
1761 int pipefds[2] = {-1,-1};
1762 debug_printf( "job=%p fed to run_command by busy_loop()'\n",
1764 run_command(&newjob, inbg, pipefds);
1768 command = (char *) xcalloc(BUFSIZ, sizeof(char));
1769 next_command = NULL;
1772 /* a job is running in the foreground; wait for it */
1774 while (!job_list.fg->progs[i].pid ||
1775 job_list.fg->progs[i].is_stopped == 1) i++;
1777 if (waitpid(job_list.fg->progs[i].pid, &status, WUNTRACED)<0)
1778 perror_msg_and_die("waitpid(%d)",job_list.fg->progs[i].pid);
1780 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1781 /* the child exited */
1782 job_list.fg->running_progs--;
1783 job_list.fg->progs[i].pid = 0;
1785 #ifdef BB_FEATURE_SH_ENVIRONMENT
1786 last_return_code=WEXITSTATUS(status);
1787 debug_printf("'%s' exited -- return code %d\n",
1788 job_list.fg->text, last_return_code);
1790 if (!job_list.fg->running_progs) {
1792 remove_job(&job_list, job_list.fg);
1796 /* the child was stopped */
1797 job_list.fg->stopped_progs++;
1798 job_list.fg->progs[i].is_stopped = 1;
1800 if (job_list.fg->stopped_progs == job_list.fg->running_progs) {
1801 printf("\n" JOB_STATUS_FORMAT, job_list.fg->jobid,
1802 "Stopped", job_list.fg->text);
1808 /* move the shell to the foreground */
1809 /* suppress messages when run from /linuxrc mag@sysgo.de */
1810 if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY)
1811 perror_msg("tcsetpgrp");
1817 /* return controlling TTY back to parent process group before exiting */
1818 if (tcsetpgrp(0, parent_pgrp))
1819 perror_msg("tcsetpgrp");
1821 /* return exit status if called with "-c" */
1822 if (input == NULL && WIFEXITED(status))
1823 return WEXITSTATUS(status);
1829 #ifdef BB_FEATURE_CLEAN_UP
1830 void free_memory(void)
1835 if (local_pending_command)
1836 free(local_pending_command);
1838 if (job_list.fg && !job_list.fg->running_progs) {
1839 remove_job(&job_list, job_list.fg);
1845 int shell_main(int argc_l, char **argv_l)
1847 int opt, interactive=FALSE;
1848 FILE *input = stdin;
1852 /* These variables need re-initializing when recursing */
1854 local_pending_command = NULL;
1855 close_me_head = NULL;
1856 job_list.head = NULL;
1858 #ifdef BB_FEATURE_SH_ENVIRONMENT
1864 if (argv[0] && argv[0][0] == '-') {
1866 prof_input = fopen("/etc/profile", "r");
1868 printf( "Couldn't open file '/etc/profile'\n");
1870 int tmp_fd = fileno(prof_input);
1872 /* Now run the file */
1873 busy_loop(prof_input);
1875 mark_closed(tmp_fd);
1879 while ((opt = getopt(argc_l, argv_l, "cxi")) > 0) {
1883 if (local_pending_command != 0)
1884 error_msg_and_die("multiple -c arguments");
1885 local_pending_command = xstrdup(argv[optind]);
1889 #ifdef BB_FEATURE_SH_ENVIRONMENT
1891 show_x_trace = TRUE;
1901 /* A shell is interactive if the `-i' flag was given, or if all of
1902 * the following conditions are met:
1904 * no arguments remaining or the -s flag given
1905 * standard input is a terminal
1906 * standard output is a terminal
1907 * Refer to Posix.2, the description of the `sh' utility. */
1908 if (argv[optind]==NULL && input==stdin &&
1909 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
1912 if (interactive==TRUE) {
1913 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1914 /* Looks like they want an interactive shell */
1915 printf( "\n\n" BB_BANNER " Built-in shell (lash)\n");
1916 printf( "Enter 'help' for a list of built-in commands.\n\n");
1917 } else if (local_pending_command==NULL) {
1918 //printf( "optind=%d argv[optind]='%s'\n", optind, argv[optind]);
1919 input = xfopen(argv[optind], "r");
1920 mark_open(fileno(input)); /* be lazy, never mark this closed */
1923 /* initialize the cwd -- this is never freed...*/
1928 #ifdef BB_FEATURE_CLEAN_UP
1929 atexit(free_memory);
1932 #ifdef BB_FEATURE_COMMAND_EDITING
1933 cmdedit_set_initial_prompt();
1938 return (busy_loop(input));