1 /* vi: set sw=4 ts=4: */
3 * sh.c -- a prototype Bourne shell grammar parser
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle.
13 * The execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash,
15 * which is Copyright (C) 2000 by Lineo, Inc., and
16 * written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
17 * That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
18 * Erik W. Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated rewrites.
21 * simple_itoa() was lifted from boa-0.93.15
22 * b_addchr() derived from similar w_addchar function in glibc-2.2
23 * setup_redirect(), redirect_opt_num(), and big chunks of main()
24 * and many builtins derived from contributions by Erik Andersen
25 * miscellaneous bugfixes from Matt Kraai
27 * There are two big (and related) architecture differences between
28 * this parser and the lash parser. One is that this version is
29 * actually designed from the ground up to understand nearly all
30 * of the Bourne grammar. The second, consequential change is that
31 * the parser and input reader have been turned inside out. Now,
32 * the parser is in control, and asks for input as needed. The old
33 * way had the input reader in control, and it asked for parsing to
34 * take place as needed. The new way makes it much easier to properly
35 * handle the recursion implicit in the various substitutions, especially
36 * across continuation lines.
38 * Bash grammar not implemented: (how many of these were in original sh?)
39 * $@ (those sure look like weird quoting rules)
41 * ! negation operator for pipes
42 * &> and >& redirection of stdout+stderr
45 * fancy forms of Parameter Expansion
47 * Arithmetic Expansion
48 * <(list) and >(list) Process Substitution
49 * reserved words: case, esac, select, function
50 * Here Documents ( << word )
53 * job handling woefully incomplete and buggy
54 * reserved word execution woefully incomplete and buggy
56 * port selected bugfixes from post-0.49 busybox lash - done?
57 * finish implementing reserved words: for, while, until, do, done
58 * change { and } from special chars to reserved words
59 * builtins: break, continue, eval, return, set, trap, ulimit
61 * handle children going into background
62 * clean up recognition of null pipes
63 * check setting of global_argc and global_argv
64 * control-C handling, probably with longjmp
65 * follow IFS rules more precisely, including update semantics
66 * figure out what to do with backslash-newline
67 * explain why we use signal instead of sigaction
68 * propagate syntax errors, die on resource errors?
69 * continuation lines, both explicit and implicit - done?
70 * memory leak finding and plugging - done?
71 * more testing, especially quoting rules and redirection
72 * document how quoting rules not precisely followed for variable assignments
73 * maybe change map[] to use 2-bit entries
74 * (eventually) remove all the printf's
76 * This program is free software; you can redistribute it and/or modify
77 * it under the terms of the GNU General Public License as published by
78 * the Free Software Foundation; either version 2 of the License, or
79 * (at your option) any later version.
81 * This program is distributed in the hope that it will be useful,
82 * but WITHOUT ANY WARRANTY; without even the implied warranty of
83 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
84 * General Public License for more details.
86 * You should have received a copy of the GNU General Public License
87 * along with this program; if not, write to the Free Software
88 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
90 #include <ctype.h> /* isalpha, isdigit */
91 #include <unistd.h> /* getpid */
92 #include <stdlib.h> /* getenv, atoi */
93 #include <string.h> /* strchr */
94 #include <stdio.h> /* popen etc. */
95 #include <glob.h> /* glob, of course */
96 #include <stdarg.h> /* va_list */
99 #include <getopt.h> /* should be pretty obvious */
101 #include <sys/stat.h> /* ulimit */
102 #include <sys/types.h>
103 #include <sys/wait.h>
106 /* #include <dmalloc.h> */
107 /* #define DEBUG_SHELL */
113 #define applet_name "hush"
114 #include "standalone.h"
115 #define hush_main main
116 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
119 #define SPECIAL_VAR_SYMBOL 03
120 #define FLAG_EXIT_FROM_LOOP 1
121 #define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
122 #define FLAG_REPARSING (1 << 2) /* >=2nd pass */
126 REDIRECT_OVERWRITE = 2,
132 /* The descrip member of this structure is only used to make debugging
134 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
136 { O_RDONLY, 0, "<" },
137 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
138 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
139 { O_RDONLY, -1, "<<" },
150 /* might eventually control execution */
167 #define FLAG_END (1<<RES_NONE)
168 #define FLAG_IF (1<<RES_IF)
169 #define FLAG_THEN (1<<RES_THEN)
170 #define FLAG_ELIF (1<<RES_ELIF)
171 #define FLAG_ELSE (1<<RES_ELSE)
172 #define FLAG_FI (1<<RES_FI)
173 #define FLAG_FOR (1<<RES_FOR)
174 #define FLAG_WHILE (1<<RES_WHILE)
175 #define FLAG_UNTIL (1<<RES_UNTIL)
176 #define FLAG_DO (1<<RES_DO)
177 #define FLAG_DONE (1<<RES_DONE)
178 #define FLAG_IN (1<<RES_IN)
179 #define FLAG_START (1<<RES_XXXX)
181 /* This holds pointers to the various results of parsing */
183 struct child_prog *child;
184 struct pipe *list_head;
186 struct redir_struct *pending_redirect;
188 int old_flag; /* for figuring out valid reserved words */
189 struct p_context *stack;
190 int type; /* define type of parser : ";$" common or special symbol */
191 /* How about quoting status? */
194 struct redir_struct {
195 redir_type type; /* type of redirection */
196 int fd; /* file descriptor being redirected */
197 int dup; /* -1, or file descriptor being duplicated */
198 struct redir_struct *next; /* pointer to the next redirect in the list */
199 glob_t word; /* *word.gl_pathv is the filename */
203 pid_t pid; /* 0 if exited */
204 char **argv; /* program name and arguments */
205 struct pipe *group; /* if non-NULL, first in group or subshell */
206 int subshell; /* flag, non-zero if group must be forked */
207 struct redir_struct *redirects; /* I/O redirections */
208 glob_t glob_result; /* result of parameter globbing */
209 int is_stopped; /* is the program currently running? */
210 struct pipe *family; /* pointer back to the child's parent pipe */
211 int sp; /* number of SPECIAL_VAR_SYMBOL */
216 int jobid; /* job number */
217 int num_progs; /* total number of programs in job */
218 int running_progs; /* number of programs running */
219 char *text; /* name of job */
220 char *cmdbuf; /* buffer various argv's point into */
221 pid_t pgrp; /* process group ID for the job */
222 struct child_prog *progs; /* array of commands in pipe */
223 struct pipe *next; /* to track background commands */
224 int stopped_progs; /* number of programs alive, but stopped */
225 int job_context; /* bitmask defining current context */
226 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
227 reserved_style r_mode; /* supports if, for, while, until */
232 struct close_me *next;
240 struct variables *next;
243 /* globals, connect us to the outside world
244 * the first three support $?, $#, and $1 */
246 unsigned int global_argc;
247 unsigned int last_return_code;
248 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
250 /* "globals" within this file */
252 static char map[256];
253 static int fake_mode;
254 static int interactive;
255 static struct close_me *close_me_head;
256 static const char *cwd;
257 static struct pipe *job_list;
258 static unsigned int last_bg_pid;
259 static unsigned int last_jobid;
260 static unsigned int shell_terminal;
263 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
264 struct variables *top_vars = &shell_ver;
267 #define B_CHUNK (100)
277 #define NULL_O_STRING {NULL,0,0,0,0}
278 /* used for initialization:
279 o_string foo = NULL_O_STRING; */
281 /* I can almost use ordinary FILE *. Is open_memstream() universally
282 * available? Where is it documented? */
289 int (*get) (struct in_str *);
290 int (*peek) (struct in_str *);
292 #define b_getch(input) ((input)->get(input))
293 #define b_peek(input) ((input)->peek(input))
295 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
297 struct built_in_command {
298 char *cmd; /* name */
299 char *descr; /* description */
300 int (*function) (struct child_prog *); /* function ptr */
303 /* belongs in busybox.h */
304 static inline int max(int a, int b) {
308 /* This should be in utility.c */
310 static void debug_printf(const char *format, ...)
313 va_start(args, format);
314 vfprintf(stderr, format, args);
318 static inline void debug_printf(const char *format, ...) { }
320 #define final_printf debug_printf
322 static void __syntax(char *file, int line) {
323 error_msg("syntax error %s:%d", file, line);
325 #define syntax() __syntax(__FILE__, __LINE__)
327 /* Index of subroutines: */
328 /* function prototypes for builtins */
329 static int builtin_cd(struct child_prog *child);
330 static int builtin_env(struct child_prog *child);
331 static int builtin_eval(struct child_prog *child);
332 static int builtin_exec(struct child_prog *child);
333 static int builtin_exit(struct child_prog *child);
334 static int builtin_export(struct child_prog *child);
335 static int builtin_fg_bg(struct child_prog *child);
336 static int builtin_help(struct child_prog *child);
337 static int builtin_jobs(struct child_prog *child);
338 static int builtin_pwd(struct child_prog *child);
339 static int builtin_read(struct child_prog *child);
340 static int builtin_set(struct child_prog *child);
341 static int builtin_shift(struct child_prog *child);
342 static int builtin_source(struct child_prog *child);
343 static int builtin_umask(struct child_prog *child);
344 static int builtin_unset(struct child_prog *child);
345 static int builtin_not_written(struct child_prog *child);
346 /* o_string manipulation: */
347 static int b_check_space(o_string *o, int len);
348 static int b_addchr(o_string *o, int ch);
349 static void b_reset(o_string *o);
350 static int b_addqchr(o_string *o, int ch, int quote);
351 static int b_adduint(o_string *o, unsigned int i);
352 /* in_str manipulations: */
353 static int static_get(struct in_str *i);
354 static int static_peek(struct in_str *i);
355 static int file_get(struct in_str *i);
356 static int file_peek(struct in_str *i);
357 static void setup_file_in_str(struct in_str *i, FILE *f);
358 static void setup_string_in_str(struct in_str *i, const char *s);
359 /* close_me manipulations: */
360 static void mark_open(int fd);
361 static void mark_closed(int fd);
362 static void close_all(void);
363 /* "run" the final data structures: */
364 static char *indenter(int i);
365 static int free_pipe_list(struct pipe *head, int indent);
366 static int free_pipe(struct pipe *pi, int indent);
367 /* really run the final data structures: */
368 static int setup_redirects(struct child_prog *prog, int squirrel[]);
369 static int run_list_real(struct pipe *pi);
370 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
371 static int run_pipe_real(struct pipe *pi);
372 /* extended glob support: */
373 static int globhack(const char *src, int flags, glob_t *pglob);
374 static int glob_needed(const char *s);
375 static int xglob(o_string *dest, int flags, glob_t *pglob);
376 /* variable assignment: */
377 static int is_assignment(const char *s);
378 /* data structure manipulation: */
379 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
380 static void initialize_context(struct p_context *ctx);
381 static int done_word(o_string *dest, struct p_context *ctx);
382 static int done_command(struct p_context *ctx);
383 static int done_pipe(struct p_context *ctx, pipe_style type);
384 /* primary string parsing: */
385 static int redirect_dup_num(struct in_str *input);
386 static int redirect_opt_num(o_string *o);
387 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
388 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
389 static char *lookup_param(char *src);
390 static char *make_string(char **inp);
391 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
392 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
393 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
395 static int parse_stream_outer(struct in_str *inp, int flag);
396 static int parse_string_outer(const char *s, int flag);
397 static int parse_file_outer(FILE *f);
398 /* job management: */
399 static int checkjobs(struct pipe* fg_pipe);
400 static void insert_bg_job(struct pipe *pi);
401 static void remove_bg_job(struct pipe *pi);
402 /* local variable support */
403 static char **make_list_in(char **inp, char *name);
404 static char *insert_var_value(char *inp);
405 static char *get_local_var(const char *var);
406 static void unset_local_var(const char *name);
407 static int set_local_var(const char *s, int flg_export);
409 /* Table of built-in functions. They can be forked or not, depending on
410 * context: within pipes, they fork. As simple commands, they do not.
411 * When used in non-forking context, they can change global variables
412 * in the parent shell process. If forked, of course they can not.
413 * For example, 'unset foo | whatever' will parse and run, but foo will
414 * still be set at the end. */
415 static struct built_in_command bltins[] = {
416 {"bg", "Resume a job in the background", builtin_fg_bg},
417 {"break", "Exit for, while or until loop", builtin_not_written},
418 {"cd", "Change working directory", builtin_cd},
419 {"continue", "Continue for, while or until loop", builtin_not_written},
420 {"env", "Print all environment variables", builtin_env},
421 {"eval", "Construct and run shell command", builtin_eval},
422 {"exec", "Exec command, replacing this shell with the exec'd process",
424 {"exit", "Exit from shell()", builtin_exit},
425 {"export", "Set environment variable", builtin_export},
426 {"fg", "Bring job into the foreground", builtin_fg_bg},
427 {"jobs", "Lists the active jobs", builtin_jobs},
428 {"pwd", "Print current directory", builtin_pwd},
429 {"read", "Input environment variable", builtin_read},
430 {"return", "Return from a function", builtin_not_written},
431 {"set", "Set/unset shell local variables", builtin_set},
432 {"shift", "Shift positional parameters", builtin_shift},
433 {"trap", "Trap signals", builtin_not_written},
434 {"ulimit","Controls resource limits", builtin_not_written},
435 {"umask","Sets file creation mask", builtin_umask},
436 {"unset", "Unset environment variable", builtin_unset},
437 {".", "Source-in and run commands in a file", builtin_source},
438 {"help", "List shell built-in commands", builtin_help},
442 static const char *set_cwd(void)
445 cwd = NULL; /* xgetcwd(arg) called free(arg) */
446 cwd = xgetcwd((char *)cwd);
452 /* built-in 'eval' handler */
453 static int builtin_eval(struct child_prog *child)
456 int rcode = EXIT_SUCCESS;
458 if (child->argv[1]) {
459 str = make_string(child->argv + 1);
460 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
461 FLAG_PARSE_SEMICOLON);
463 rcode = last_return_code;
468 /* built-in 'cd <path>' handler */
469 static int builtin_cd(struct child_prog *child)
472 if (child->argv[1] == NULL)
473 newdir = getenv("HOME");
475 newdir = child->argv[1];
477 printf("cd: %s: %s\n", newdir, strerror(errno));
484 /* built-in 'env' handler */
485 static int builtin_env(struct child_prog *dummy)
488 if (e == NULL) return EXIT_FAILURE;
495 /* built-in 'exec' handler */
496 static int builtin_exec(struct child_prog *child)
498 if (child->argv[1] == NULL)
499 return EXIT_SUCCESS; /* Really? */
505 /* built-in 'exit' handler */
506 static int builtin_exit(struct child_prog *child)
508 if (child->argv[1] == NULL)
509 exit(last_return_code);
510 exit (atoi(child->argv[1]));
513 /* built-in 'export VAR=value' handler */
514 static int builtin_export(struct child_prog *child)
517 char *name = child->argv[1];
520 return (builtin_env(child));
526 char *value = strchr(name, '=');
530 /* They are exporting something without an =VALUE */
532 value = get_local_var(name);
534 size_t ln = strlen(name);
536 tmp = realloc(name, ln+strlen(value)+2);
540 sprintf(tmp+ln, "=%s", value);
544 /* bash does not return an error when trying to export
545 * an undefined variable. Do likewise. */
551 perror_msg("export");
553 res = set_local_var(name, 1);
560 /* built-in 'fg' and 'bg' handler */
561 static int builtin_fg_bg(struct child_prog *child)
564 struct pipe *pi=NULL;
568 /* If they gave us no args, assume they want the last backgrounded task */
569 if (!child->argv[1]) {
570 for (pi = job_list; pi; pi = pi->next) {
571 if (pi->jobid == last_jobid) {
576 error_msg("%s: no current job", child->argv[0]);
580 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
581 error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
584 for (pi = job_list; pi; pi = pi->next) {
585 if (pi->jobid == jobnum) {
590 error_msg("%s: %d: no such job", child->argv[0], jobnum);
595 if (*child->argv[0] == 'f') {
596 /* Put the job into the foreground. */
597 tcsetpgrp(shell_terminal, pi->pgrp);
600 /* Restart the processes in the job */
601 for (i = 0; i < pi->num_progs; i++)
602 pi->progs[i].is_stopped = 0;
604 if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
608 perror_msg("kill (SIGCONT)");
612 pi->stopped_progs = 0;
616 /* built-in 'help' handler */
617 static int builtin_help(struct child_prog *dummy)
619 struct built_in_command *x;
621 printf("\nBuilt-in commands:\n");
622 printf("-------------------\n");
623 for (x = bltins; x->cmd; x++) {
626 printf("%s\t%s\n", x->cmd, x->descr);
632 /* built-in 'jobs' handler */
633 static int builtin_jobs(struct child_prog *child)
638 for (job = job_list; job; job = job->next) {
639 if (job->running_progs == job->stopped_progs)
640 status_string = "Stopped";
642 status_string = "Running";
644 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
650 /* built-in 'pwd' handler */
651 static int builtin_pwd(struct child_prog *dummy)
657 /* built-in 'read VAR' handler */
658 static int builtin_read(struct child_prog *child)
662 if (child->argv[1]) {
666 string[0] = 0; /* In case stdin has only EOF */
668 fgets(string, sizeof(string), stdin);
670 var = malloc(strlen(child->argv[1])+strlen(string)+2);
672 sprintf(var, "%s=%s", child->argv[1], string);
673 res = set_local_var(var, 0);
677 fprintf(stderr, "read: %m\n");
678 free(var); /* So not move up to avoid breaking errno */
681 do res=getchar(); while(res!='\n' && res!=EOF);
686 /* built-in 'set VAR=value' handler */
687 static int builtin_set(struct child_prog *child)
689 char *temp = child->argv[1];
693 for(e = top_vars; e; e=e->next)
694 printf("%s=%s\n", e->name, e->value);
696 set_local_var(temp, 0);
702 /* Built-in 'shift' handler */
703 static int builtin_shift(struct child_prog *child)
706 if (child->argv[1]) {
707 n=atoi(child->argv[1]);
709 if (n>=0 && n<global_argc) {
710 /* XXX This probably breaks $0 */
719 /* Built-in '.' handler (read-in and execute commands from file) */
720 static int builtin_source(struct child_prog *child)
725 if (child->argv[1] == NULL)
728 /* XXX search through $PATH is missing */
729 input = fopen(child->argv[1], "r");
731 error_msg("Couldn't open file '%s'", child->argv[1]);
735 /* Now run the file */
736 /* XXX argv and argc are broken; need to save old global_argv
737 * (pointer only is OK!) on this stack frame,
738 * set global_argv=child->argv+1, recurse, and restore. */
739 mark_open(fileno(input));
740 status = parse_file_outer(input);
741 mark_closed(fileno(input));
746 static int builtin_umask(struct child_prog *child)
749 const char *arg = child->argv[1];
752 new_umask=strtoul(arg, &end, 8);
753 if (*end!='\0' || end == arg) {
757 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
763 /* built-in 'unset VAR' handler */
764 static int builtin_unset(struct child_prog *child)
766 /* bash returned already true */
767 unset_local_var(child->argv[1]);
771 static int builtin_not_written(struct child_prog *child)
773 printf("builtin_%s not written\n",child->argv[0]);
777 static int b_check_space(o_string *o, int len)
779 /* It would be easy to drop a more restrictive policy
780 * in here, such as setting a maximum string length */
781 if (o->length + len > o->maxlen) {
782 char *old_data = o->data;
783 /* assert (data == NULL || o->maxlen != 0); */
784 o->maxlen += max(2*len, B_CHUNK);
785 o->data = realloc(o->data, 1 + o->maxlen);
786 if (o->data == NULL) {
790 return o->data == NULL;
793 static int b_addchr(o_string *o, int ch)
795 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
796 if (b_check_space(o, 1)) return B_NOSPAC;
797 o->data[o->length] = ch;
799 o->data[o->length] = '\0';
803 static void b_reset(o_string *o)
807 if (o->data != NULL) *o->data = '\0';
810 static void b_free(o_string *o)
818 /* My analysis of quoting semantics tells me that state information
819 * is associated with a destination, not a source.
821 static int b_addqchr(o_string *o, int ch, int quote)
823 if (quote && strchr("*?[\\",ch)) {
825 rc = b_addchr(o, '\\');
828 return b_addchr(o, ch);
831 /* belongs in utility.c */
832 char *simple_itoa(unsigned int i)
834 /* 21 digits plus null terminator, good for 64-bit or smaller ints */
835 static char local[22];
836 char *p = &local[21];
845 static int b_adduint(o_string *o, unsigned int i)
848 char *p = simple_itoa(i);
849 /* no escape checking necessary */
850 do r=b_addchr(o, *p++); while (r==0 && *p);
854 static int static_get(struct in_str *i)
857 if (ch=='\0') return EOF;
861 static int static_peek(struct in_str *i)
866 static inline void cmdedit_set_initial_prompt(void)
868 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
877 static inline void setup_prompt_string(int promptmode, char **prompt_str)
879 debug_printf("setup_prompt_string %d ",promptmode);
880 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
881 /* Set up the prompt */
882 if (promptmode == 1) {
884 PS1=xmalloc(strlen(cwd)+4);
885 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
891 *prompt_str = (promptmode==1)? PS1 : PS2;
893 debug_printf("result %s\n",*prompt_str);
896 static void get_user_input(struct in_str *i)
899 static char the_command[BUFSIZ];
901 setup_prompt_string(i->promptmode, &prompt_str);
902 #ifdef CONFIG_FEATURE_COMMAND_EDITING
904 ** enable command line editing only while a command line
905 ** is actually being read; otherwise, we'll end up bequeathing
906 ** atexit() handlers and other unwanted stuff to our
907 ** child processes (rob@sysgo.de)
909 cmdedit_read_input(prompt_str, the_command);
911 fputs(prompt_str, stdout);
913 the_command[0]=fgetc(i->file);
920 /* This is the magic location that prints prompts
921 * and gets data back from the user */
922 static int file_get(struct in_str *i)
927 /* If there is data waiting, eat it up */
931 /* need to double check i->file because we might be doing something
932 * more complicated by now, like sourcing or substituting. */
933 if (i->__promptme && interactive && i->file == stdin) {
934 while(! i->p || (interactive && strlen(i->p)==0) ) {
946 debug_printf("b_getch: got a %d\n", ch);
948 if (ch == '\n') i->__promptme=1;
952 /* All the callers guarantee this routine will never be
953 * used right after a newline, so prompting is not needed.
955 static int file_peek(struct in_str *i)
960 i->peek_buf[0] = fgetc(i->file);
961 i->peek_buf[1] = '\0';
963 debug_printf("b_peek: got a %d\n", *i->p);
968 static void setup_file_in_str(struct in_str *i, FILE *f)
978 static void setup_string_in_str(struct in_str *i, const char *s)
980 i->peek = static_peek;
987 static void mark_open(int fd)
989 struct close_me *new = xmalloc(sizeof(struct close_me));
991 new->next = close_me_head;
995 static void mark_closed(int fd)
997 struct close_me *tmp;
998 if (close_me_head == NULL || close_me_head->fd != fd)
999 error_msg_and_die("corrupt close_me");
1000 tmp = close_me_head;
1001 close_me_head = close_me_head->next;
1005 static void close_all(void)
1008 for (c=close_me_head; c; c=c->next) {
1011 close_me_head = NULL;
1014 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1015 * and stderr if they are redirected. */
1016 static int setup_redirects(struct child_prog *prog, int squirrel[])
1019 struct redir_struct *redir;
1021 for (redir=prog->redirects; redir; redir=redir->next) {
1022 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1023 /* something went wrong in the parse. Pretend it didn't happen */
1026 if (redir->dup == -1) {
1027 mode=redir_table[redir->type].mode;
1028 openfd = open(redir->word.gl_pathv[0], mode, 0666);
1030 /* this could get lost if stderr has been redirected, but
1031 bash and ash both lose it as well (though zsh doesn't!) */
1032 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1036 openfd = redir->dup;
1039 if (openfd != redir->fd) {
1040 if (squirrel && redir->fd < 3) {
1041 squirrel[redir->fd] = dup(redir->fd);
1046 dup2(openfd, redir->fd);
1047 if (redir->dup == -1)
1055 static void restore_redirects(int squirrel[])
1058 for (i=0; i<3; i++) {
1061 /* No error checking. I sure wouldn't know what
1062 * to do with an error if I found one! */
1070 /* XXX no exit() here. If you don't exec, use _exit instead.
1071 * The at_exit handlers apparently confuse the calling process,
1072 * in particular stdin handling. Not sure why? */
1073 static void pseudo_exec(struct child_prog *child)
1077 struct built_in_command *x;
1079 for (i=0; is_assignment(child->argv[i]); i++) {
1080 debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1081 p = insert_var_value(child->argv[i]);
1083 if (p != child->argv[i]) free(p);
1085 child->argv+=i; /* XXX this hack isn't so horrible, since we are about
1086 to exit, and therefore don't need to keep data
1087 structures consistent for free() use. */
1088 /* If a variable is assigned in a forest, and nobody listens,
1089 * was it ever really set?
1091 if (child->argv[0] == NULL) {
1092 _exit(EXIT_SUCCESS);
1096 * Check if the command matches any of the builtins.
1097 * Depending on context, this might be redundant. But it's
1098 * easier to waste a few CPU cycles than it is to figure out
1099 * if this is one of those cases.
1101 for (x = bltins; x->cmd; x++) {
1102 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1103 debug_printf("builtin exec %s\n", child->argv[0]);
1104 rcode = x->function(child);
1110 /* Check if the command matches any busybox internal commands
1112 * FIXME: This feature is not 100% safe, since
1113 * BusyBox is not fully reentrant, so we have no guarantee the things
1114 * from the .bss are still zeroed, or that things from .data are still
1115 * at their defaults. We could exec ourself from /proc/self/exe, but I
1116 * really dislike relying on /proc for things. We could exec ourself
1117 * from global_argv[0], but if we are in a chroot, we may not be able
1118 * to find ourself... */
1119 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1122 char** argv_l=child->argv;
1123 char *name = child->argv[0];
1125 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1126 /* Following discussions from November 2000 on the busybox mailing
1127 * list, the default configuration, (without
1128 * get_last_path_component()) lets the user force use of an
1129 * external command by specifying the full (with slashes) filename.
1130 * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN, then applets
1131 * _aways_ override external commands, so if you want to run
1132 * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1133 * filesystem and is _not_ busybox. Some systems may want this,
1135 name = get_last_path_component(name);
1137 /* Count argc for use in a second... */
1138 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1140 debug_printf("running applet %s\n", name);
1141 run_applet_by_name(name, argc_l, child->argv);
1144 debug_printf("exec of %s\n",child->argv[0]);
1145 execvp(child->argv[0],child->argv);
1146 perror_msg("couldn't exec: %s",child->argv[0]);
1148 } else if (child->group) {
1149 debug_printf("runtime nesting to group\n");
1150 interactive=0; /* crucial!!!! */
1151 rcode = run_list_real(child->group);
1152 /* OK to leak memory by not calling free_pipe_list,
1153 * since this process is about to exit */
1156 /* Can happen. See what bash does with ">foo" by itself. */
1157 debug_printf("trying to pseudo_exec null command\n");
1158 _exit(EXIT_SUCCESS);
1162 static void insert_bg_job(struct pipe *pi)
1164 struct pipe *thejob;
1166 /* Linear search for the ID of the job to use */
1168 for (thejob = job_list; thejob; thejob = thejob->next)
1169 if (thejob->jobid >= pi->jobid)
1170 pi->jobid = thejob->jobid + 1;
1172 /* add thejob to the list of running jobs */
1174 thejob = job_list = xmalloc(sizeof(*thejob));
1176 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1177 thejob->next = xmalloc(sizeof(*thejob));
1178 thejob = thejob->next;
1181 /* physically copy the struct job */
1182 memcpy(thejob, pi, sizeof(struct pipe));
1183 thejob->next = NULL;
1184 thejob->running_progs = thejob->num_progs;
1185 thejob->stopped_progs = 0;
1186 thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1188 //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
1190 char *bar=thejob->text;
1191 char **foo=pi->progs[0].argv;
1192 while(foo && *foo) {
1193 bar += sprintf(bar, "%s ", *foo++);
1197 /* we don't wait for background thejobs to return -- append it
1198 to the list of backgrounded thejobs and leave it alone */
1199 printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1200 last_bg_pid = thejob->progs[0].pid;
1201 last_jobid = thejob->jobid;
1204 /* remove a backgrounded job */
1205 static void remove_bg_job(struct pipe *pi)
1207 struct pipe *prev_pipe;
1209 if (pi == job_list) {
1210 job_list = pi->next;
1212 prev_pipe = job_list;
1213 while (prev_pipe->next != pi)
1214 prev_pipe = prev_pipe->next;
1215 prev_pipe->next = pi->next;
1218 last_jobid = job_list->jobid;
1222 pi->stopped_progs = 0;
1227 /* Checks to see if any processes have exited -- if they
1228 have, figure out why and see if a job has completed */
1229 static int checkjobs(struct pipe* fg_pipe)
1237 attributes = WUNTRACED;
1238 if (fg_pipe==NULL) {
1239 attributes |= WNOHANG;
1242 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1245 for (i=0; i < fg_pipe->num_progs; i++) {
1246 if (fg_pipe->progs[i].pid == childpid) {
1247 if (i==fg_pipe->num_progs-1)
1248 rcode=WEXITSTATUS(status);
1249 (fg_pipe->num_progs)--;
1255 for (pi = job_list; pi; pi = pi->next) {
1257 while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1260 if (prognum < pi->num_progs)
1265 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1269 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1271 pi->running_progs--;
1272 pi->progs[prognum].pid = 0;
1274 if (!pi->running_progs) {
1275 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1280 pi->stopped_progs++;
1281 pi->progs[prognum].is_stopped = 1;
1284 /* Printing this stuff is a pain, since it tends to
1285 * overwrite the prompt an inconveinient moments. So
1287 if (pi->stopped_progs == pi->num_progs) {
1288 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1294 if (childpid == -1 && errno != ECHILD)
1295 perror_msg("waitpid");
1297 /* move the shell to the foreground */
1298 //if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
1299 // perror_msg("tcsetpgrp-2");
1303 /* Figure out our controlling tty, checking in order stderr,
1304 * stdin, and stdout. If check_pgrp is set, also check that
1305 * we belong to the foreground process group associated with
1306 * that tty. The value of shell_terminal is needed in order to call
1307 * tcsetpgrp(shell_terminal, ...); */
1308 void controlling_tty(int check_pgrp)
1312 if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1313 && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1314 && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1315 goto shell_terminal_error;
1317 if (check_pgrp && curpgrp != getpgid(0))
1318 goto shell_terminal_error;
1322 shell_terminal_error:
1323 shell_terminal = -1;
1327 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1328 * to finish. See checkjobs().
1330 * return code is normally -1, when the caller has to wait for children
1331 * to finish to determine the exit status of the pipe. If the pipe
1332 * is a simple builtin command, however, the action is done by the
1333 * time run_pipe_real returns, and the exit code is provided as the
1336 * The input of the pipe is always stdin, the output is always
1337 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1338 * because it tries to avoid running the command substitution in
1339 * subshell, when that is in fact necessary. The subshell process
1340 * now has its stdout directed to the input of the appropriate pipe,
1341 * so this routine is noticeably simpler.
1343 static int run_pipe_real(struct pipe *pi)
1346 int nextin, nextout;
1347 int pipefds[2]; /* pipefds[0] is for reading */
1348 struct child_prog *child;
1349 struct built_in_command *x;
1355 /* Check if this is a simple builtin (not part of a pipe).
1356 * Builtins within pipes have to fork anyway, and are handled in
1357 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1359 if (pi->num_progs == 1) child = & (pi->progs[0]);
1360 if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1361 int squirrel[] = {-1, -1, -1};
1363 debug_printf("non-subshell grouping\n");
1364 setup_redirects(child, squirrel);
1365 /* XXX could we merge code with following builtin case,
1366 * by creating a pseudo builtin that calls run_list_real? */
1367 rcode = run_list_real(child->group);
1368 restore_redirects(squirrel);
1370 } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1371 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1372 if (i!=0 && child->argv[i]==NULL) {
1373 /* assignments, but no command: set the local environment */
1374 for (i=0; child->argv[i]!=NULL; i++) {
1376 /* Ok, this case is tricky. We have to decide if this is a
1377 * local variable, or an already exported variable. If it is
1378 * already exported, we have to export the new value. If it is
1379 * not exported, we need only set this as a local variable.
1380 * This junk is all to decide whether or not to export this
1384 name = xstrdup(child->argv[i]);
1385 debug_printf("Local environment set: %s\n", name);
1386 value = strchr(name, '=');
1389 if ( get_local_var(name)) {
1393 p = insert_var_value(child->argv[i]);
1394 set_local_var(p, export_me);
1395 if (p != child->argv[i]) free(p);
1397 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1399 for (i = 0; is_assignment(child->argv[i]); i++) {
1400 p = insert_var_value(child->argv[i]);
1402 if (p != child->argv[i]) {
1410 str = make_string((child->argv + i));
1411 parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1413 return last_return_code;
1415 for (x = bltins; x->cmd; x++) {
1416 if (strcmp(child->argv[i], x->cmd) == 0 ) {
1417 int squirrel[] = {-1, -1, -1};
1419 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1420 debug_printf("magic exec\n");
1421 setup_redirects(child,NULL);
1422 return EXIT_SUCCESS;
1424 debug_printf("builtin inline %s\n", child->argv[0]);
1425 /* XXX setup_redirects acts on file descriptors, not FILEs.
1426 * This is perfect for work that comes after exec().
1427 * Is it really safe for inline use? Experimentally,
1428 * things seem to work with glibc. */
1429 setup_redirects(child, squirrel);
1430 child->argv+=i; /* XXX horrible hack */
1431 rcode = x->function(child);
1432 child->argv-=i; /* XXX restore hack so free() can work right */
1433 restore_redirects(squirrel);
1439 for (i = 0; i < pi->num_progs; i++) {
1440 child = & (pi->progs[i]);
1442 /* pipes are inserted between pairs of commands */
1443 if ((i + 1) < pi->num_progs) {
1444 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1445 nextout = pipefds[1];
1451 /* XXX test for failed fork()? */
1452 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
1453 if (!(child->pid = fork()))
1455 if (!(child->pid = vfork()))
1458 /* Set the handling for job control signals back to the default. */
1459 signal(SIGINT, SIG_DFL);
1460 signal(SIGQUIT, SIG_DFL);
1461 signal(SIGTERM, SIG_DFL);
1462 signal(SIGTSTP, SIG_DFL);
1463 signal(SIGTTIN, SIG_DFL);
1464 signal(SIGTTOU, SIG_DFL);
1465 signal(SIGCHLD, SIG_DFL);
1477 if (pipefds[0]!=-1) {
1478 close(pipefds[0]); /* opposite end of our output pipe */
1481 /* Like bash, explicit redirects override pipes,
1482 * and the pipe fd is available for dup'ing. */
1483 setup_redirects(child,NULL);
1485 if (interactive && pi->followup!=PIPE_BG) {
1486 /* If we (the child) win the race, put ourselves in the process
1487 * group whose leader is the first process in this pipe. */
1489 pi->pgrp = getpid();
1491 if (setpgid(0, pi->pgrp) == 0) {
1492 tcsetpgrp(2, pi->pgrp);
1500 /* put our child in the process group whose leader is the
1501 first process in this pipe */
1503 pi->pgrp = child->pid;
1505 /* Don't check for errors. The child may be dead already,
1506 * in which case setpgid returns error code EACCES. */
1507 setpgid(child->pid, pi->pgrp);
1514 /* If there isn't another process, nextin is garbage
1515 but it doesn't matter */
1516 nextin = pipefds[0];
1521 static int run_list_real(struct pipe *pi)
1523 char *save_name = NULL;
1525 char **save_list = NULL;
1529 int rcode=0, flag_skip=1;
1530 int flag_restore = 0;
1531 int if_code=0, next_if_code=0; /* need double-buffer to handle elif */
1532 reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1533 /* check syntax for "for" */
1534 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1535 if ((rpipe->r_mode == RES_IN ||
1536 rpipe->r_mode == RES_FOR) &&
1537 (rpipe->next == NULL)) {
1541 if ((rpipe->r_mode == RES_IN &&
1542 (rpipe->next->r_mode == RES_IN &&
1543 rpipe->next->progs->argv != NULL))||
1544 (rpipe->r_mode == RES_FOR &&
1545 rpipe->next->r_mode != RES_IN)) {
1550 for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1551 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1552 pi->r_mode == RES_FOR) {
1560 debug_printf("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
1561 if (rmode == skip_more_in_this_rmode && flag_skip) {
1562 if (pi->followup == PIPE_SEQ) flag_skip=0;
1566 skip_more_in_this_rmode = RES_XXXX;
1567 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1568 if (rmode == RES_THEN && if_code) continue;
1569 if (rmode == RES_ELSE && !if_code) continue;
1570 if (rmode == RES_ELIF && !if_code) continue;
1571 if (rmode == RES_FOR && pi->num_progs) {
1573 /* if no variable values after "in" we skip "for" */
1574 if (!pi->next->progs->argv) continue;
1575 /* create list of variable values */
1576 list = make_list_in(pi->next->progs->argv,
1577 pi->progs->argv[0]);
1579 save_name = pi->progs->argv[0];
1580 pi->progs->argv[0] = NULL;
1584 free(pi->progs->argv[0]);
1588 pi->progs->argv[0] = save_name;
1589 pi->progs->glob_result.gl_pathv[0] =
1593 /* insert new value from list for variable */
1594 if (pi->progs->argv[0])
1595 free(pi->progs->argv[0]);
1596 pi->progs->argv[0] = *list++;
1597 pi->progs->glob_result.gl_pathv[0] =
1601 if (rmode == RES_IN) continue;
1602 if (rmode == RES_DO) {
1603 if (!flag_rep) continue;
1605 if ((rmode == RES_DONE)) {
1612 if (pi->num_progs == 0) continue;
1613 save_num_progs = pi->num_progs; /* save number of programs */
1614 rcode = run_pipe_real(pi);
1615 debug_printf("run_pipe_real returned %d\n",rcode);
1617 /* We only ran a builtin: rcode was set by the return value
1618 * of run_pipe_real(), and we don't need to wait for anything. */
1619 } else if (pi->followup==PIPE_BG) {
1620 /* XXX check bash's behavior with nontrivial pipes */
1621 /* XXX compute jobid */
1622 /* XXX what does bash do with attempts to background builtins? */
1624 rcode = EXIT_SUCCESS;
1627 /* move the new process group into the foreground */
1628 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1629 perror_msg("tcsetpgrp-3");
1630 rcode = checkjobs(pi);
1631 /* move the shell to the foreground */
1632 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1633 perror_msg("tcsetpgrp-4");
1635 rcode = checkjobs(pi);
1637 debug_printf("checkjobs returned %d\n",rcode);
1639 last_return_code=rcode;
1640 pi->num_progs = save_num_progs; /* restore number of programs */
1641 if ( rmode == RES_IF || rmode == RES_ELIF )
1642 next_if_code=rcode; /* can be overwritten a number of times */
1643 if (rmode == RES_WHILE)
1644 flag_rep = !last_return_code;
1645 if (rmode == RES_UNTIL)
1646 flag_rep = last_return_code;
1647 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1648 (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1649 skip_more_in_this_rmode=rmode;
1655 /* broken, of course, but OK for testing */
1656 static char *indenter(int i)
1658 static char blanks[]=" ";
1659 return &blanks[sizeof(blanks)-i-1];
1662 /* return code is the exit status of the pipe */
1663 static int free_pipe(struct pipe *pi, int indent)
1666 struct child_prog *child;
1667 struct redir_struct *r, *rnext;
1668 int a, i, ret_code=0;
1669 char *ind = indenter(indent);
1671 if (pi->stopped_progs > 0)
1673 final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1674 for (i=0; i<pi->num_progs; i++) {
1675 child = &pi->progs[i];
1676 final_printf("%s command %d:\n",ind,i);
1678 for (a=0,p=child->argv; *p; a++,p++) {
1679 final_printf("%s argv[%d] = %s\n",ind,a,*p);
1681 globfree(&child->glob_result);
1683 } else if (child->group) {
1684 final_printf("%s begin group (subshell:%d)\n",ind, child->subshell);
1685 ret_code = free_pipe_list(child->group,indent+3);
1686 final_printf("%s end group\n",ind);
1688 final_printf("%s (nil)\n",ind);
1690 for (r=child->redirects; r; r=rnext) {
1691 final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1693 /* guard against the case >$FOO, where foo is unset or blank */
1694 if (r->word.gl_pathv) {
1695 final_printf(" %s\n", *r->word.gl_pathv);
1699 final_printf("&%d\n", r->dup);
1704 child->redirects=NULL;
1706 free(pi->progs); /* children are an array, they get freed all at once */
1711 static int free_pipe_list(struct pipe *head, int indent)
1713 int rcode=0; /* if list has no members */
1714 struct pipe *pi, *next;
1715 char *ind = indenter(indent);
1716 for (pi=head; pi; pi=next) {
1717 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1718 rcode = free_pipe(pi, indent);
1719 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1727 /* Select which version we will use */
1728 static int run_list(struct pipe *pi)
1732 rcode = run_list_real(pi);
1734 /* free_pipe_list has the side effect of clearing memory
1735 * In the long run that function can be merged with run_list_real,
1736 * but doing that now would hobble the debugging effort. */
1737 free_pipe_list(pi,0);
1741 /* The API for glob is arguably broken. This routine pushes a non-matching
1742 * string into the output structure, removing non-backslashed backslashes.
1743 * If someone can prove me wrong, by performing this function within the
1744 * original glob(3) api, feel free to rewrite this routine into oblivion.
1745 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1746 * XXX broken if the last character is '\\', check that before calling.
1748 static int globhack(const char *src, int flags, glob_t *pglob)
1753 for (cnt=1, s=src; s && *s; s++) {
1754 if (*s == '\\') s++;
1758 if (!dest) return GLOB_NOSPACE;
1759 if (!(flags & GLOB_APPEND)) {
1760 pglob->gl_pathv=NULL;
1765 pathc = ++pglob->gl_pathc;
1766 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1767 if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
1768 pglob->gl_pathv[pathc-1]=dest;
1769 pglob->gl_pathv[pathc]=NULL;
1770 for (s=src; s && *s; s++, dest++) {
1771 if (*s == '\\') s++;
1778 /* XXX broken if the last character is '\\', check that before calling */
1779 static int glob_needed(const char *s)
1782 if (*s == '\\') s++;
1783 if (strchr("*[?",*s)) return 1;
1789 static void globprint(glob_t *pglob)
1792 debug_printf("glob_t at %p:\n", pglob);
1793 debug_printf(" gl_pathc=%d gl_pathv=%p gl_offs=%d gl_flags=%d\n",
1794 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
1795 for (i=0; i<pglob->gl_pathc; i++)
1796 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
1797 pglob->gl_pathv[i], pglob->gl_pathv[i]);
1801 static int xglob(o_string *dest, int flags, glob_t *pglob)
1805 /* short-circuit for null word */
1806 /* we can code this better when the debug_printf's are gone */
1807 if (dest->length == 0) {
1808 if (dest->nonnull) {
1809 /* bash man page calls this an "explicit" null */
1810 gr = globhack(dest->data, flags, pglob);
1811 debug_printf("globhack returned %d\n",gr);
1815 } else if (glob_needed(dest->data)) {
1816 gr = glob(dest->data, flags, NULL, pglob);
1817 debug_printf("glob returned %d\n",gr);
1818 if (gr == GLOB_NOMATCH) {
1819 /* quote removal, or more accurately, backslash removal */
1820 gr = globhack(dest->data, flags, pglob);
1821 debug_printf("globhack returned %d\n",gr);
1824 gr = globhack(dest->data, flags, pglob);
1825 debug_printf("globhack returned %d\n",gr);
1827 if (gr == GLOB_NOSPACE)
1828 error_msg_and_die("out of memory during glob");
1829 if (gr != 0) { /* GLOB_ABORTED ? */
1830 error_msg("glob(3) error %d",gr);
1832 /* globprint(glob_target); */
1836 /* This is used to get/check local shell variables */
1837 static char *get_local_var(const char *s)
1839 struct variables *cur;
1843 for (cur = top_vars; cur; cur=cur->next)
1844 if(strcmp(cur->name, s)==0)
1849 /* This is used to set local shell variables
1850 flg_export==0 if only local (not exporting) variable
1851 flg_export==1 if "new" exporting environ
1852 flg_export>1 if current startup environ (not call putenv()) */
1853 static int set_local_var(const char *s, int flg_export)
1857 struct variables *cur;
1861 /* Assume when we enter this function that we are already in
1862 * NAME=VALUE format. So the first order of business is to
1863 * split 's' on the '=' into 'name' and 'value' */
1864 value = strchr(name, '=');
1865 if (value==0 && ++value==0) {
1871 for(cur = top_vars; cur; cur = cur->next) {
1872 if(strcmp(cur->name, name)==0)
1877 if(strcmp(cur->value, value)==0) {
1878 if(flg_export>0 && cur->flg_export==0)
1879 cur->flg_export=flg_export;
1883 if(cur->flg_read_only) {
1884 error_msg("%s: readonly variable", name);
1887 if(flg_export>0 || cur->flg_export>1)
1891 cur->value = strdup(value);
1895 cur = malloc(sizeof(struct variables));
1899 cur->name = strdup(name);
1900 if(cur->name == 0) {
1904 struct variables *bottom = top_vars;
1905 cur->value = strdup(value);
1907 cur->flg_export = flg_export;
1908 cur->flg_read_only = 0;
1909 while(bottom->next) bottom=bottom->next;
1915 if(result==0 && cur->flg_export==1) {
1917 result = putenv(name);
1920 if(result>0) /* equivalent to previous set */
1926 static void unset_local_var(const char *name)
1928 struct variables *cur;
1931 for (cur = top_vars; cur; cur=cur->next) {
1932 if(strcmp(cur->name, name)==0)
1936 struct variables *next = top_vars;
1937 if(cur->flg_read_only) {
1938 error_msg("%s: readonly variable", name);
1942 unsetenv(cur->name);
1945 while (next->next != cur)
1947 next->next = cur->next;
1954 static int is_assignment(const char *s)
1956 if (s==NULL || !isalpha(*s)) return 0;
1958 while(isalnum(*s) || *s=='_') ++s;
1962 /* the src parameter allows us to peek forward to a possible &n syntax
1963 * for file descriptor duplication, e.g., "2>&1".
1964 * Return code is 0 normally, 1 if a syntax error is detected in src.
1965 * Resource errors (in xmalloc) cause the process to exit */
1966 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1967 struct in_str *input)
1969 struct child_prog *child=ctx->child;
1970 struct redir_struct *redir = child->redirects;
1971 struct redir_struct *last_redir=NULL;
1973 /* Create a new redir_struct and drop it onto the end of the linked list */
1978 redir = xmalloc(sizeof(struct redir_struct));
1980 redir->word.gl_pathv=NULL;
1982 last_redir->next=redir;
1984 child->redirects=redir;
1988 redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
1990 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1992 /* Check for a '2>&1' type redirect */
1993 redir->dup = redirect_dup_num(input);
1994 if (redir->dup == -2) return 1; /* syntax error */
1995 if (redir->dup != -1) {
1996 /* Erik had a check here that the file descriptor in question
1997 * is legit; I postpone that to "run time"
1998 * A "-" representation of "close me" shows up as a -3 here */
1999 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2001 /* We do _not_ try to open the file that src points to,
2002 * since we need to return and let src be expanded first.
2003 * Set ctx->pending_redirect, so we know what to do at the
2004 * end of the next parsed word.
2006 ctx->pending_redirect = redir;
2011 struct pipe *new_pipe(void) {
2013 pi = xmalloc(sizeof(struct pipe));
2017 pi->followup = 0; /* invalid */
2021 static void initialize_context(struct p_context *ctx)
2024 ctx->pending_redirect=NULL;
2026 ctx->list_head=new_pipe();
2027 ctx->pipe=ctx->list_head;
2031 done_command(ctx); /* creates the memory for working child */
2034 /* normal return is 0
2035 * if a reserved word is found, and processed, return 1
2036 * should handle if, then, elif, else, fi, for, while, until, do, done.
2037 * case, function, and select are obnoxious, save those for later.
2039 int reserved_word(o_string *dest, struct p_context *ctx)
2041 struct reserved_combo {
2046 /* Mostly a list of accepted follow-up reserved words.
2047 * FLAG_END means we are done with the sequence, and are ready
2048 * to turn the compound list into a command.
2049 * FLAG_START means the word must start a new compound list.
2051 static struct reserved_combo reserved_list[] = {
2052 { "if", RES_IF, FLAG_THEN | FLAG_START },
2053 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2054 { "elif", RES_ELIF, FLAG_THEN },
2055 { "else", RES_ELSE, FLAG_FI },
2056 { "fi", RES_FI, FLAG_END },
2057 { "for", RES_FOR, FLAG_IN | FLAG_START },
2058 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2059 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2060 { "in", RES_IN, FLAG_DO },
2061 { "do", RES_DO, FLAG_DONE },
2062 { "done", RES_DONE, FLAG_END }
2064 struct reserved_combo *r;
2065 for (r=reserved_list;
2066 #define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
2067 r<reserved_list+NRES; r++) {
2068 if (strcmp(dest->data, r->literal) == 0) {
2069 debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2070 if (r->flag & FLAG_START) {
2071 struct p_context *new = xmalloc(sizeof(struct p_context));
2072 debug_printf("push stack\n");
2073 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2080 *new = *ctx; /* physical copy */
2081 initialize_context(ctx);
2083 } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2090 ctx->old_flag = r->flag;
2091 if (ctx->old_flag & FLAG_END) {
2092 struct p_context *old;
2093 debug_printf("pop stack\n");
2094 done_pipe(ctx,PIPE_SEQ);
2096 old->child->group = ctx->list_head;
2097 old->child->subshell = 0;
2098 *ctx = *old; /* physical copy */
2108 /* normal return is 0.
2109 * Syntax or xglob errors return 1. */
2110 static int done_word(o_string *dest, struct p_context *ctx)
2112 struct child_prog *child=ctx->child;
2113 glob_t *glob_target;
2116 debug_printf("done_word: %s %p\n", dest->data, child);
2117 if (dest->length == 0 && !dest->nonnull) {
2118 debug_printf(" true null, ignored\n");
2121 if (ctx->pending_redirect) {
2122 glob_target = &ctx->pending_redirect->word;
2126 return 1; /* syntax error, groups and arglists don't mix */
2128 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2129 debug_printf("checking %s for reserved-ness\n",dest->data);
2130 if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2132 glob_target = &child->glob_result;
2133 if (child->argv) flags |= GLOB_APPEND;
2135 gr = xglob(dest, flags, glob_target);
2136 if (gr != 0) return 1;
2139 if (ctx->pending_redirect) {
2140 ctx->pending_redirect=NULL;
2141 if (glob_target->gl_pathc != 1) {
2142 error_msg("ambiguous redirect");
2146 child->argv = glob_target->gl_pathv;
2148 if (ctx->w == RES_FOR) {
2149 done_word(dest,ctx);
2150 done_pipe(ctx,PIPE_SEQ);
2155 /* The only possible error here is out of memory, in which case
2157 static int done_command(struct p_context *ctx)
2159 /* The child is really already in the pipe structure, so
2160 * advance the pipe counter and make a new, null child.
2161 * Only real trickiness here is that the uncommitted
2162 * child structure, to which ctx->child points, is not
2163 * counted in pi->num_progs. */
2164 struct pipe *pi=ctx->pipe;
2165 struct child_prog *prog=ctx->child;
2167 if (prog && prog->group == NULL
2168 && prog->argv == NULL
2169 && prog->redirects == NULL) {
2170 debug_printf("done_command: skipping null command\n");
2174 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2176 debug_printf("done_command: initializing\n");
2178 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2180 prog = pi->progs + pi->num_progs;
2181 prog->redirects = NULL;
2183 prog->is_stopped = 0;
2185 prog->glob_result.gl_pathv = NULL;
2189 prog->type = ctx->type;
2191 /* but ctx->pipe and ctx->list_head remain unchanged */
2195 static int done_pipe(struct p_context *ctx, pipe_style type)
2198 done_command(ctx); /* implicit closure of previous command */
2199 debug_printf("done_pipe, type %d\n", type);
2200 ctx->pipe->followup = type;
2201 ctx->pipe->r_mode = ctx->w;
2203 ctx->pipe->next = new_p;
2206 done_command(ctx); /* set up new pipe to accept commands */
2210 /* peek ahead in the in_str to find out if we have a "&n" construct,
2211 * as in "2>&1", that represents duplicating a file descriptor.
2212 * returns either -2 (syntax error), -1 (no &), or the number found.
2214 static int redirect_dup_num(struct in_str *input)
2218 if (ch != '&') return -1;
2220 b_getch(input); /* get the & */
2224 return -3; /* "-" represents "close me" */
2226 while (isdigit(ch)) {
2234 error_msg("ambiguous redirect");
2238 /* If a redirect is immediately preceded by a number, that number is
2239 * supposed to tell which file descriptor to redirect. This routine
2240 * looks for such preceding numbers. In an ideal world this routine
2241 * needs to handle all the following classes of redirects...
2242 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2243 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2244 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2245 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2246 * A -1 output from this program means no valid number was found, so the
2247 * caller should use the appropriate default for this redirection.
2249 static int redirect_opt_num(o_string *o)
2253 if (o->length==0) return -1;
2254 for(num=0; num<o->length; num++) {
2255 if (!isdigit(*(o->data+num))) {
2259 /* reuse num (and save an int) */
2265 FILE *generate_stream_from_list(struct pipe *head)
2269 int pid, channel[2];
2270 if (pipe(channel)<0) perror_msg_and_die("pipe");
2271 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
2277 perror_msg_and_die("fork");
2278 } else if (pid==0) {
2280 if (channel[1] != 1) {
2285 #define SURROGATE "surrogate response"
2286 write(1,SURROGATE,sizeof(SURROGATE));
2287 _exit(run_list(head));
2289 _exit(run_list_real(head)); /* leaks memory */
2292 debug_printf("forked child %d\n",pid);
2294 pf = fdopen(channel[0],"r");
2295 debug_printf("pipe on FILE *%p\n",pf);
2297 free_pipe_list(head,0);
2298 pf=popen("echo surrogate response","r");
2299 debug_printf("started fake pipe on FILE *%p\n",pf);
2304 /* this version hacked for testing purposes */
2305 /* return code is exit status of the process that is run. */
2306 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2309 o_string result=NULL_O_STRING;
2310 struct p_context inner;
2312 struct in_str pipe_str;
2313 initialize_context(&inner);
2315 /* recursion to generate command */
2316 retcode = parse_stream(&result, &inner, input, subst_end);
2317 if (retcode != 0) return retcode; /* syntax error or EOF */
2318 done_word(&result, &inner);
2319 done_pipe(&inner, PIPE_SEQ);
2322 p=generate_stream_from_list(inner.list_head);
2323 if (p==NULL) return 1;
2324 mark_open(fileno(p));
2325 setup_file_in_str(&pipe_str, p);
2327 /* now send results of command back into original context */
2328 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2329 /* XXX In case of a syntax error, should we try to kill the child?
2330 * That would be tough to do right, so just read until EOF. */
2332 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2335 debug_printf("done reading from pipe, pclose()ing\n");
2336 /* This is the step that wait()s for the child. Should be pretty
2337 * safe, since we just read an EOF from its stdout. We could try
2338 * to better, by using wait(), and keeping track of background jobs
2339 * at the same time. That would be a lot of work, and contrary
2340 * to the KISS philosophy of this program. */
2341 mark_closed(fileno(p));
2343 free_pipe_list(inner.list_head,0);
2344 debug_printf("pclosed, retcode=%d\n",retcode);
2345 /* XXX this process fails to trim a single trailing newline */
2349 static int parse_group(o_string *dest, struct p_context *ctx,
2350 struct in_str *input, int ch)
2353 struct p_context sub;
2354 struct child_prog *child = ctx->child;
2357 return 1; /* syntax error, groups and arglists don't mix */
2359 initialize_context(&sub);
2361 case '(': endch=')'; child->subshell=1; break;
2362 case '{': endch='}'; break;
2363 default: syntax(); /* really logic error */
2365 rcode=parse_stream(dest,&sub,input,endch);
2366 done_word(dest,&sub); /* finish off the final word in the subcontext */
2367 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2368 child->group = sub.list_head;
2370 /* child remains "open", available for possible redirects */
2373 /* basically useful version until someone wants to get fancier,
2374 * see the bash man page under "Parameter Expansion" */
2375 static char *lookup_param(char *src)
2381 p = get_local_var(src);
2386 /* return code: 0 for OK, 1 for syntax error */
2387 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2391 int ch = input->peek(input); /* first character after the $ */
2392 debug_printf("handle_dollar: ch=%c\n",ch);
2394 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2396 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2400 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2401 } else if (isdigit(ch)) {
2402 i = ch-'0'; /* XXX is $0 special? */
2403 if (i<global_argc) {
2404 parse_string(dest, ctx, global_argv[i]); /* recursion */
2407 } else switch (ch) {
2409 b_adduint(dest,getpid());
2413 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2417 b_adduint(dest,last_return_code);
2421 b_adduint(dest,global_argc ? global_argc-1 : 0);
2425 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2428 /* XXX maybe someone will try to escape the '}' */
2429 while(ch=b_getch(input),ch!=EOF && ch!='}') {
2436 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2440 process_command_subs(dest, ctx, input, ')');
2444 for (i=1; i<global_argc; i++) {
2445 parse_string(dest, ctx, global_argv[i]);
2446 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2452 /* still unhandled, but should be eventually */
2453 error_msg("unhandled syntax: $%c",ch);
2457 b_addqchr(dest,'$',dest->quote);
2459 /* Eat the character if the flag was set. If the compiler
2460 * is smart enough, we could substitute "b_getch(input);"
2461 * for all the "advance = 1;" above, and also end up with
2462 * a nice size-optimized program. Hah! That'll be the day.
2464 if (advance) b_getch(input);
2468 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2471 setup_string_in_str(&foo, src);
2472 return parse_stream(dest, ctx, &foo, '\0');
2475 /* return code is 0 for normal exit, 1 for syntax error */
2476 int parse_stream(o_string *dest, struct p_context *ctx,
2477 struct in_str *input, int end_trigger)
2481 redir_type redir_style;
2484 /* Only double-quote state is handled in the state variable dest->quote.
2485 * A single-quote triggers a bypass of the main loop until its mate is
2486 * found. When recursing, quote state is passed in via dest->quote. */
2488 debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2489 while ((ch=b_getch(input))!=EOF) {
2491 next = (ch == '\n') ? 0 : b_peek(input);
2492 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2493 ch,ch,m,dest->quote);
2494 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2495 b_addqchr(dest, ch, dest->quote);
2497 if (m==2) { /* unquoted IFS */
2498 if (done_word(dest, ctx)) {
2501 /* If we aren't performing a substitution, treat a newline as a
2502 * command separator. */
2503 if (end_trigger != '\0' && ch=='\n')
2504 done_pipe(ctx,PIPE_SEQ);
2506 if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2507 debug_printf("leaving parse_stream (triggered)\n");
2512 /* Yahoo! Time to run with it! */
2513 done_pipe(ctx,PIPE_SEQ);
2514 run_list(ctx->list_head);
2515 initialize_context(ctx);
2518 if (m!=2) switch (ch) {
2520 if (dest->length == 0 && !dest->quote) {
2521 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2523 b_addqchr(dest, ch, dest->quote);
2531 b_addqchr(dest, '\\', dest->quote);
2532 b_addqchr(dest, b_getch(input), dest->quote);
2535 if (handle_dollar(dest, ctx, input)!=0) return 1;
2539 while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2549 dest->quote = !dest->quote;
2552 process_command_subs(dest, ctx, input, '`');
2555 redir_fd = redirect_opt_num(dest);
2556 done_word(dest, ctx);
2557 redir_style=REDIRECT_OVERWRITE;
2559 redir_style=REDIRECT_APPEND;
2561 } else if (next == '(') {
2562 syntax(); /* until we support >(list) Process Substitution */
2565 setup_redirect(ctx, redir_fd, redir_style, input);
2568 redir_fd = redirect_opt_num(dest);
2569 done_word(dest, ctx);
2570 redir_style=REDIRECT_INPUT;
2572 redir_style=REDIRECT_HEREIS;
2574 } else if (next == '>') {
2575 redir_style=REDIRECT_IO;
2577 } else if (next == '(') {
2578 syntax(); /* until we support <(list) Process Substitution */
2581 setup_redirect(ctx, redir_fd, redir_style, input);
2584 done_word(dest, ctx);
2585 done_pipe(ctx,PIPE_SEQ);
2588 done_word(dest, ctx);
2591 done_pipe(ctx,PIPE_AND);
2593 done_pipe(ctx,PIPE_BG);
2597 done_word(dest, ctx);
2600 done_pipe(ctx,PIPE_OR);
2602 /* we could pick up a file descriptor choice here
2603 * with redirect_opt_num(), but bash doesn't do it.
2604 * "echo foo 2| cat" yields "foo 2". */
2610 if (parse_group(dest, ctx, input, ch)!=0) return 1;
2614 syntax(); /* Proper use of this character caught by end_trigger */
2618 syntax(); /* this is really an internal logic error */
2623 /* complain if quote? No, maybe we just finished a command substitution
2624 * that was quoted. Example:
2625 * $ echo "`cat foo` plus more"
2626 * and we just got the EOF generated by the subshell that ran "cat foo"
2627 * The only real complaint is if we got an EOF when end_trigger != '\0',
2628 * that is, we were really supposed to get end_trigger, and never got
2629 * one before the EOF. Can't use the standard "syntax error" return code,
2630 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
2631 debug_printf("leaving parse_stream (EOF)\n");
2632 if (end_trigger != '\0') return -1;
2636 void mapset(const unsigned char *set, int code)
2638 const unsigned char *s;
2639 for (s=set; *s; s++) map[*s] = code;
2642 void update_ifs_map(void)
2644 /* char *ifs and char map[256] are both globals. */
2645 ifs = getenv("IFS");
2646 if (ifs == NULL) ifs=" \t\n";
2647 /* Precompute a list of 'flow through' behavior so it can be treated
2648 * quickly up front. Computation is necessary because of IFS.
2649 * Special case handling of IFS == " \t\n" is not implemented.
2650 * The map[] array only really needs two bits each, and on most machines
2651 * that would be faster because of the reduced L1 cache footprint.
2653 memset(map,0,sizeof(map)); /* most characters flow through always */
2654 mapset("\\$'\"`", 3); /* never flow through */
2655 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2656 mapset(ifs, 2); /* also flow through if quoted */
2659 /* most recursion does not come through here, the exeception is
2660 * from builtin_source() */
2661 int parse_stream_outer(struct in_str *inp, int flag)
2664 struct p_context ctx;
2665 o_string temp=NULL_O_STRING;
2669 initialize_context(&ctx);
2671 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
2673 rcode = parse_stream(&temp, &ctx, inp, '\n');
2674 if (rcode != 1 && ctx.old_flag != 0) {
2677 if (rcode != 1 && ctx.old_flag == 0) {
2678 done_word(&temp, &ctx);
2679 done_pipe(&ctx,PIPE_SEQ);
2680 run_list(ctx.list_head);
2682 if (ctx.old_flag != 0) {
2689 free_pipe_list(ctx.list_head,0);
2692 } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
2696 static int parse_string_outer(const char *s, int flag)
2698 struct in_str input;
2699 setup_string_in_str(&input, s);
2700 return parse_stream_outer(&input, flag);
2703 static int parse_file_outer(FILE *f)
2706 struct in_str input;
2707 setup_file_in_str(&input, f);
2708 rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
2712 /* Make sure we have a controlling tty. If we get started under a job
2713 * aware app (like bash for example), make sure we are now in charge so
2714 * we don't fight over who gets the foreground */
2715 static void setup_job_control(void)
2717 static pid_t shell_pgrp;
2718 /* Loop until we are in the foreground. */
2719 while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
2720 kill (- shell_pgrp, SIGTTIN);
2722 /* Ignore interactive and job-control signals. */
2723 signal(SIGINT, SIG_IGN);
2724 signal(SIGQUIT, SIG_IGN);
2725 signal(SIGTERM, SIG_IGN);
2726 signal(SIGTSTP, SIG_IGN);
2727 signal(SIGTTIN, SIG_IGN);
2728 signal(SIGTTOU, SIG_IGN);
2729 signal(SIGCHLD, SIG_IGN);
2731 /* Put ourselves in our own process group. */
2733 shell_pgrp = getpid ();
2734 setpgid (shell_pgrp, shell_pgrp);
2736 /* Grab control of the terminal. */
2737 tcsetpgrp(shell_terminal, shell_pgrp);
2740 int hush_main(int argc, char **argv)
2746 /* XXX what should these be while sourcing /etc/profile? */
2750 /* (re?) initialize globals. Sometimes hush_main() ends up calling
2751 * hush_main(), therefore we cannot rely on the BSS to zero out this
2752 * stuff. Reset these to 0 every time. */
2754 /* map[] is taken care of with call to update_ifs_map() */
2757 close_me_head = NULL;
2762 /* Initialize some more globals to non-zero values */
2764 #ifdef CONFIG_FEATURE_COMMAND_EDITING
2765 cmdedit_set_initial_prompt();
2771 /* initialize our shell local variables with the values
2772 * currently living in the environment */
2775 set_local_var(*e, 2); /* without call putenv() */
2778 last_return_code=EXIT_SUCCESS;
2781 if (argv[0] && argv[0][0] == '-') {
2782 debug_printf("\nsourcing /etc/profile\n");
2783 if ((input = fopen("/etc/profile", "r")) != NULL) {
2784 mark_open(fileno(input));
2785 parse_file_outer(input);
2786 mark_closed(fileno(input));
2792 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2796 global_argv = argv+optind;
2797 global_argc = argc-optind;
2798 opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
2810 fprintf(stderr, "Usage: sh [FILE]...\n"
2811 " or: sh -c command [args]...\n\n");
2818 /* A shell is interactive if the `-i' flag was given, or if all of
2819 * the following conditions are met:
2821 * no arguments remaining or the -s flag given
2822 * standard input is a terminal
2823 * standard output is a terminal
2824 * Refer to Posix.2, the description of the `sh' utility. */
2825 if (argv[optind]==NULL && input==stdin &&
2826 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
2830 debug_printf("\ninteractive=%d\n", interactive);
2832 /* Looks like they want an interactive shell */
2833 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
2834 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
2835 printf( "Enter 'help' for a list of built-in commands.\n\n");
2837 setup_job_control();
2840 if (argv[optind]==NULL) {
2841 opt=parse_file_outer(stdin);
2845 debug_printf("\nrunning script '%s'\n", argv[optind]);
2846 global_argv = argv+optind;
2847 global_argc = argc-optind;
2848 input = xfopen(argv[optind], "r");
2849 opt = parse_file_outer(input);
2851 #ifdef CONFIG_FEATURE_CLEAN_UP
2853 if (cwd && cwd != unknown)
2856 struct variables *cur, *tmp;
2857 for(cur = top_vars; cur; cur = tmp) {
2859 if (!cur->flg_read_only) {
2869 return(opt?opt:last_return_code);
2872 static char *insert_var_value(char *inp)
2874 int res_str_len = 0;
2877 char *p, *p1, *res_str = NULL;
2879 while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
2882 res_str = xrealloc(res_str, (res_str_len + len));
2883 strncpy((res_str + res_str_len), inp, len);
2887 p = strchr(inp, SPECIAL_VAR_SYMBOL);
2889 if ((p1 = lookup_param(inp))) {
2890 len = res_str_len + strlen(p1);
2891 res_str = xrealloc(res_str, (1 + len));
2892 strcpy((res_str + res_str_len), p1);
2895 *p = SPECIAL_VAR_SYMBOL;
2900 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
2901 strcpy((res_str + res_str_len), inp);
2902 while ((p = strchr(res_str, '\n'))) {
2906 return (res_str == NULL) ? inp : res_str;
2909 static char **make_list_in(char **inp, char *name)
2912 int name_len = strlen(name);
2917 /* create list of variable values */
2918 list = xmalloc(sizeof(*list));
2919 for (i = 0; inp[i]; i++) {
2920 p3 = insert_var_value(inp[i]);
2927 if ((p2 = strchr(p1, ' '))) {
2933 /* we use n + 2 in realloc for list,because we add
2934 * new element and then we will add NULL element */
2935 list = xrealloc(list, sizeof(*list) * (n + 2));
2936 list[n] = xmalloc(2 + name_len + len);
2937 strcpy(list[n], name);
2938 strcat(list[n], "=");
2939 strncat(list[n], p1, len);
2940 list[n++][name_len + len + 1] = '\0';
2943 if (p3 != inp[i]) free(p3);
2949 /* Make new string for parser */
2950 static char * make_string(char ** inp)
2957 for (n = 0; inp[n]; n++) {
2958 p = insert_var_value(inp[n]);
2959 str = xrealloc(str, (len + strlen(p)));
2966 len = strlen(str) + 3;
2967 if (p != inp[n]) free(p);
2970 *(str + len) = '\n';
2971 *(str + len + 1) = '\0';