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. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * simple_itoa() was lifted from boa-0.93.15
24 * b_addchr() derived from similar w_addchar function in glibc-2.2
25 * setup_redirect(), redirect_opt_num(), and big chunks of main()
26 * and many builtins derived from contributions by Erik Andersen
27 * miscellaneous bugfixes from Matt Kraai
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * Bash grammar not implemented: (how many of these were in original sh?)
41 * $@ (those sure look like weird quoting rules)
43 * ! negation operator for pipes
44 * &> and >& redirection of stdout+stderr
47 * fancy forms of Parameter Expansion
49 * Arithmetic Expansion
50 * <(list) and >(list) Process Substitution
51 * reserved words: case, esac, select, function
52 * Here Documents ( << word )
55 * job handling woefully incomplete and buggy
56 * reserved word execution woefully incomplete and buggy
58 * port selected bugfixes from post-0.49 busybox lash - done?
59 * finish implementing reserved words: for, while, until, do, done
60 * change { and } from special chars to reserved words
61 * builtins: break, continue, eval, return, set, trap, ulimit
63 * handle children going into background
64 * clean up recognition of null pipes
65 * check setting of global_argc and global_argv
66 * control-C handling, probably with longjmp
67 * follow IFS rules more precisely, including update semantics
68 * figure out what to do with backslash-newline
69 * explain why we use signal instead of sigaction
70 * propagate syntax errors, die on resource errors?
71 * continuation lines, both explicit and implicit - done?
72 * memory leak finding and plugging - done?
73 * more testing, especially quoting rules and redirection
74 * document how quoting rules not precisely followed for variable assignments
75 * maybe change map[] to use 2-bit entries
76 * (eventually) remove all the printf's
78 * This program is free software; you can redistribute it and/or modify
79 * it under the terms of the GNU General Public License as published by
80 * the Free Software Foundation; either version 2 of the License, or
81 * (at your option) any later version.
83 * This program is distributed in the hope that it will be useful,
84 * but WITHOUT ANY WARRANTY; without even the implied warranty of
85 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
86 * General Public License for more details.
88 * You should have received a copy of the GNU General Public License
89 * along with this program; if not, write to the Free Software
90 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
92 #include <ctype.h> /* isalpha, isdigit */
93 #include <unistd.h> /* getpid */
94 #include <stdlib.h> /* getenv, atoi */
95 #include <string.h> /* strchr */
96 #include <stdio.h> /* popen etc. */
97 #include <glob.h> /* glob, of course */
98 #include <stdarg.h> /* va_list */
101 #include <getopt.h> /* should be pretty obvious */
103 #include <sys/stat.h> /* ulimit */
104 #include <sys/types.h>
105 #include <sys/wait.h>
108 /* #include <dmalloc.h> */
109 /* #define DEBUG_SHELL */
115 #define bb_applet_name "hush"
116 #include "standalone.h"
117 #define hush_main main
118 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
121 #define SPECIAL_VAR_SYMBOL 03
122 #define FLAG_EXIT_FROM_LOOP 1
123 #define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
124 #define FLAG_REPARSING (1 << 2) /* >=2nd pass */
128 REDIRECT_OVERWRITE = 2,
134 /* The descrip member of this structure is only used to make debugging
136 static const struct {int mode; int default_fd; const char *descrip;} redir_table[] = {
138 { O_RDONLY, 0, "<" },
139 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
140 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
141 { O_RDONLY, -1, "<<" },
152 /* might eventually control execution */
169 #define FLAG_END (1<<RES_NONE)
170 #define FLAG_IF (1<<RES_IF)
171 #define FLAG_THEN (1<<RES_THEN)
172 #define FLAG_ELIF (1<<RES_ELIF)
173 #define FLAG_ELSE (1<<RES_ELSE)
174 #define FLAG_FI (1<<RES_FI)
175 #define FLAG_FOR (1<<RES_FOR)
176 #define FLAG_WHILE (1<<RES_WHILE)
177 #define FLAG_UNTIL (1<<RES_UNTIL)
178 #define FLAG_DO (1<<RES_DO)
179 #define FLAG_DONE (1<<RES_DONE)
180 #define FLAG_IN (1<<RES_IN)
181 #define FLAG_START (1<<RES_XXXX)
183 /* This holds pointers to the various results of parsing */
185 struct child_prog *child;
186 struct pipe *list_head;
188 struct redir_struct *pending_redirect;
190 int old_flag; /* for figuring out valid reserved words */
191 struct p_context *stack;
192 int type; /* define type of parser : ";$" common or special symbol */
193 /* How about quoting status? */
196 struct redir_struct {
197 redir_type type; /* type of redirection */
198 int fd; /* file descriptor being redirected */
199 int dup; /* -1, or file descriptor being duplicated */
200 struct redir_struct *next; /* pointer to the next redirect in the list */
201 glob_t word; /* *word.gl_pathv is the filename */
205 pid_t pid; /* 0 if exited */
206 char **argv; /* program name and arguments */
207 struct pipe *group; /* if non-NULL, first in group or subshell */
208 int subshell; /* flag, non-zero if group must be forked */
209 struct redir_struct *redirects; /* I/O redirections */
210 glob_t glob_result; /* result of parameter globbing */
211 int is_stopped; /* is the program currently running? */
212 struct pipe *family; /* pointer back to the child's parent pipe */
213 int sp; /* number of SPECIAL_VAR_SYMBOL */
218 int jobid; /* job number */
219 int num_progs; /* total number of programs in job */
220 int running_progs; /* number of programs running */
221 char *text; /* name of job */
222 char *cmdbuf; /* buffer various argv's point into */
223 pid_t pgrp; /* process group ID for the job */
224 struct child_prog *progs; /* array of commands in pipe */
225 struct pipe *next; /* to track background commands */
226 int stopped_progs; /* number of programs alive, but stopped */
227 int job_context; /* bitmask defining current context */
228 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
229 reserved_style r_mode; /* supports if, for, while, until */
234 struct close_me *next;
242 struct variables *next;
245 /* globals, connect us to the outside world
246 * the first three support $?, $#, and $1 */
247 static char **global_argv;
248 static unsigned int global_argc;
249 static unsigned int last_return_code;
250 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
252 /* "globals" within this file */
254 static char map[256];
255 static int fake_mode;
256 static int interactive;
257 static struct close_me *close_me_head;
258 static const char *cwd;
259 static struct pipe *job_list;
260 static unsigned int last_bg_pid;
261 static unsigned int last_jobid;
262 static unsigned int shell_terminal;
265 static struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
266 static struct variables *top_vars = &shell_ver;
269 #define B_CHUNK (100)
279 #define NULL_O_STRING {NULL,0,0,0,0}
280 /* used for initialization:
281 o_string foo = NULL_O_STRING; */
283 /* I can almost use ordinary FILE *. Is open_memstream() universally
284 * available? Where is it documented? */
291 int (*get) (struct in_str *);
292 int (*peek) (struct in_str *);
294 #define b_getch(input) ((input)->get(input))
295 #define b_peek(input) ((input)->peek(input))
297 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
299 struct built_in_command {
300 const char *cmd; /* name */
301 const char *descr; /* description */
302 int (*function) (struct child_prog *); /* function ptr */
305 /* belongs in busybox.h */
306 static inline int max(int a, int b) {
310 /* This should be in utility.c */
312 static void debug_printf(const char *format, ...)
315 va_start(args, format);
316 vfprintf(stderr, format, args);
320 static inline void debug_printf(const char *format, ...) { }
322 #define final_printf debug_printf
324 static void __syntax(char *file, int line) {
325 bb_error_msg("syntax error %s:%d", file, line);
327 #define syntax() __syntax(__FILE__, __LINE__)
329 /* Index of subroutines: */
330 /* function prototypes for builtins */
331 static int builtin_cd(struct child_prog *child);
332 static int builtin_env(struct child_prog *child);
333 static int builtin_eval(struct child_prog *child);
334 static int builtin_exec(struct child_prog *child);
335 static int builtin_exit(struct child_prog *child);
336 static int builtin_export(struct child_prog *child);
337 static int builtin_fg_bg(struct child_prog *child);
338 static int builtin_help(struct child_prog *child);
339 static int builtin_jobs(struct child_prog *child);
340 static int builtin_pwd(struct child_prog *child);
341 static int builtin_read(struct child_prog *child);
342 static int builtin_set(struct child_prog *child);
343 static int builtin_shift(struct child_prog *child);
344 static int builtin_source(struct child_prog *child);
345 static int builtin_umask(struct child_prog *child);
346 static int builtin_unset(struct child_prog *child);
347 static int builtin_not_written(struct child_prog *child);
348 /* o_string manipulation: */
349 static int b_check_space(o_string *o, int len);
350 static int b_addchr(o_string *o, int ch);
351 static void b_reset(o_string *o);
352 static int b_addqchr(o_string *o, int ch, int quote);
353 static int b_adduint(o_string *o, unsigned int i);
354 /* in_str manipulations: */
355 static int static_get(struct in_str *i);
356 static int static_peek(struct in_str *i);
357 static int file_get(struct in_str *i);
358 static int file_peek(struct in_str *i);
359 static void setup_file_in_str(struct in_str *i, FILE *f);
360 static void setup_string_in_str(struct in_str *i, const char *s);
361 /* close_me manipulations: */
362 static void mark_open(int fd);
363 static void mark_closed(int fd);
364 static void close_all(void);
365 /* "run" the final data structures: */
366 static char *indenter(int i);
367 static int free_pipe_list(struct pipe *head, int indent);
368 static int free_pipe(struct pipe *pi, int indent);
369 /* really run the final data structures: */
370 static int setup_redirects(struct child_prog *prog, int squirrel[]);
371 static int run_list_real(struct pipe *pi);
372 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
373 static int run_pipe_real(struct pipe *pi);
374 /* extended glob support: */
375 static int globhack(const char *src, int flags, glob_t *pglob);
376 static int glob_needed(const char *s);
377 static int xglob(o_string *dest, int flags, glob_t *pglob);
378 /* variable assignment: */
379 static int is_assignment(const char *s);
380 /* data structure manipulation: */
381 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
382 static void initialize_context(struct p_context *ctx);
383 static int done_word(o_string *dest, struct p_context *ctx);
384 static int done_command(struct p_context *ctx);
385 static int done_pipe(struct p_context *ctx, pipe_style type);
386 /* primary string parsing: */
387 static int redirect_dup_num(struct in_str *input);
388 static int redirect_opt_num(o_string *o);
389 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
390 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
391 static char *lookup_param(char *src);
392 static char *make_string(char **inp);
393 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
394 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
395 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
397 static int parse_stream_outer(struct in_str *inp, int flag);
398 static int parse_string_outer(const char *s, int flag);
399 static int parse_file_outer(FILE *f);
400 /* job management: */
401 static int checkjobs(struct pipe* fg_pipe);
402 static void insert_bg_job(struct pipe *pi);
403 static void remove_bg_job(struct pipe *pi);
404 /* local variable support */
405 static char **make_list_in(char **inp, char *name);
406 static char *insert_var_value(char *inp);
407 static char *get_local_var(const char *var);
408 static void unset_local_var(const char *name);
409 static int set_local_var(const char *s, int flg_export);
411 /* Table of built-in functions. They can be forked or not, depending on
412 * context: within pipes, they fork. As simple commands, they do not.
413 * When used in non-forking context, they can change global variables
414 * in the parent shell process. If forked, of course they can not.
415 * For example, 'unset foo | whatever' will parse and run, but foo will
416 * still be set at the end. */
417 static const struct built_in_command bltins[] = {
418 {"bg", "Resume a job in the background", builtin_fg_bg},
419 {"break", "Exit for, while or until loop", builtin_not_written},
420 {"cd", "Change working directory", builtin_cd},
421 {"continue", "Continue for, while or until loop", builtin_not_written},
422 {"env", "Print all environment variables", builtin_env},
423 {"eval", "Construct and run shell command", builtin_eval},
424 {"exec", "Exec command, replacing this shell with the exec'd process",
426 {"exit", "Exit from shell()", builtin_exit},
427 {"export", "Set environment variable", builtin_export},
428 {"fg", "Bring job into the foreground", builtin_fg_bg},
429 {"jobs", "Lists the active jobs", builtin_jobs},
430 {"pwd", "Print current directory", builtin_pwd},
431 {"read", "Input environment variable", builtin_read},
432 {"return", "Return from a function", builtin_not_written},
433 {"set", "Set/unset shell local variables", builtin_set},
434 {"shift", "Shift positional parameters", builtin_shift},
435 {"trap", "Trap signals", builtin_not_written},
436 {"ulimit","Controls resource limits", builtin_not_written},
437 {"umask","Sets file creation mask", builtin_umask},
438 {"unset", "Unset environment variable", builtin_unset},
439 {".", "Source-in and run commands in a file", builtin_source},
440 {"help", "List shell built-in commands", builtin_help},
444 static const char *set_cwd(void)
446 if(cwd==bb_msg_unknown)
447 cwd = NULL; /* xgetcwd(arg) called free(arg) */
448 cwd = xgetcwd((char *)cwd);
450 cwd = bb_msg_unknown;
454 /* built-in 'eval' handler */
455 static int builtin_eval(struct child_prog *child)
458 int rcode = EXIT_SUCCESS;
460 if (child->argv[1]) {
461 str = make_string(child->argv + 1);
462 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
463 FLAG_PARSE_SEMICOLON);
465 rcode = last_return_code;
470 /* built-in 'cd <path>' handler */
471 static int builtin_cd(struct child_prog *child)
474 if (child->argv[1] == NULL)
475 newdir = getenv("HOME");
477 newdir = child->argv[1];
479 printf("cd: %s: %s\n", newdir, strerror(errno));
486 /* built-in 'env' handler */
487 static int builtin_env(struct child_prog *dummy)
490 if (e == NULL) return EXIT_FAILURE;
497 /* built-in 'exec' handler */
498 static int builtin_exec(struct child_prog *child)
500 if (child->argv[1] == NULL)
501 return EXIT_SUCCESS; /* Really? */
507 /* built-in 'exit' handler */
508 static int builtin_exit(struct child_prog *child)
510 if (child->argv[1] == NULL)
511 exit(last_return_code);
512 exit (atoi(child->argv[1]));
515 /* built-in 'export VAR=value' handler */
516 static int builtin_export(struct child_prog *child)
519 char *name = child->argv[1];
522 return (builtin_env(child));
528 char *value = strchr(name, '=');
532 /* They are exporting something without an =VALUE */
534 value = get_local_var(name);
536 size_t ln = strlen(name);
538 tmp = realloc(name, ln+strlen(value)+2);
542 sprintf(tmp+ln, "=%s", value);
546 /* bash does not return an error when trying to export
547 * an undefined variable. Do likewise. */
553 bb_perror_msg("export");
555 res = set_local_var(name, 1);
562 /* built-in 'fg' and 'bg' handler */
563 static int builtin_fg_bg(struct child_prog *child)
566 struct pipe *pi=NULL;
570 /* If they gave us no args, assume they want the last backgrounded task */
571 if (!child->argv[1]) {
572 for (pi = job_list; pi; pi = pi->next) {
573 if (pi->jobid == last_jobid) {
578 bb_error_msg("%s: no current job", child->argv[0]);
582 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
583 bb_error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
586 for (pi = job_list; pi; pi = pi->next) {
587 if (pi->jobid == jobnum) {
592 bb_error_msg("%s: %d: no such job", child->argv[0], jobnum);
597 if (*child->argv[0] == 'f') {
598 /* Put the job into the foreground. */
599 tcsetpgrp(shell_terminal, pi->pgrp);
602 /* Restart the processes in the job */
603 for (i = 0; i < pi->num_progs; i++)
604 pi->progs[i].is_stopped = 0;
606 if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
610 bb_perror_msg("kill (SIGCONT)");
614 pi->stopped_progs = 0;
618 /* built-in 'help' handler */
619 static int builtin_help(struct child_prog *dummy)
621 const struct built_in_command *x;
623 printf("\nBuilt-in commands:\n");
624 printf("-------------------\n");
625 for (x = bltins; x->cmd; x++) {
628 printf("%s\t%s\n", x->cmd, x->descr);
634 /* built-in 'jobs' handler */
635 static int builtin_jobs(struct child_prog *child)
640 for (job = job_list; job; job = job->next) {
641 if (job->running_progs == job->stopped_progs)
642 status_string = "Stopped";
644 status_string = "Running";
646 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
652 /* built-in 'pwd' handler */
653 static int builtin_pwd(struct child_prog *dummy)
659 /* built-in 'read VAR' handler */
660 static int builtin_read(struct child_prog *child)
664 if (child->argv[1]) {
668 string[0] = 0; /* In case stdin has only EOF */
670 fgets(string, sizeof(string), stdin);
672 var = malloc(strlen(child->argv[1])+strlen(string)+2);
674 sprintf(var, "%s=%s", child->argv[1], string);
675 res = set_local_var(var, 0);
679 fprintf(stderr, "read: %m\n");
680 free(var); /* So not move up to avoid breaking errno */
683 do res=getchar(); while(res!='\n' && res!=EOF);
688 /* built-in 'set VAR=value' handler */
689 static int builtin_set(struct child_prog *child)
691 char *temp = child->argv[1];
695 for(e = top_vars; e; e=e->next)
696 printf("%s=%s\n", e->name, e->value);
698 set_local_var(temp, 0);
704 /* Built-in 'shift' handler */
705 static int builtin_shift(struct child_prog *child)
708 if (child->argv[1]) {
709 n=atoi(child->argv[1]);
711 if (n>=0 && n<global_argc) {
712 /* XXX This probably breaks $0 */
721 /* Built-in '.' handler (read-in and execute commands from file) */
722 static int builtin_source(struct child_prog *child)
727 if (child->argv[1] == NULL)
730 /* XXX search through $PATH is missing */
731 input = fopen(child->argv[1], "r");
733 bb_error_msg("Couldn't open file '%s'", child->argv[1]);
737 /* Now run the file */
738 /* XXX argv and argc are broken; need to save old global_argv
739 * (pointer only is OK!) on this stack frame,
740 * set global_argv=child->argv+1, recurse, and restore. */
741 mark_open(fileno(input));
742 status = parse_file_outer(input);
743 mark_closed(fileno(input));
748 static int builtin_umask(struct child_prog *child)
751 const char *arg = child->argv[1];
754 new_umask=strtoul(arg, &end, 8);
755 if (*end!='\0' || end == arg) {
759 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
765 /* built-in 'unset VAR' handler */
766 static int builtin_unset(struct child_prog *child)
768 /* bash returned already true */
769 unset_local_var(child->argv[1]);
773 static int builtin_not_written(struct child_prog *child)
775 printf("builtin_%s not written\n",child->argv[0]);
779 static int b_check_space(o_string *o, int len)
781 /* It would be easy to drop a more restrictive policy
782 * in here, such as setting a maximum string length */
783 if (o->length + len > o->maxlen) {
784 char *old_data = o->data;
785 /* assert (data == NULL || o->maxlen != 0); */
786 o->maxlen += max(2*len, B_CHUNK);
787 o->data = realloc(o->data, 1 + o->maxlen);
788 if (o->data == NULL) {
792 return o->data == NULL;
795 static int b_addchr(o_string *o, int ch)
797 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
798 if (b_check_space(o, 1)) return B_NOSPAC;
799 o->data[o->length] = ch;
801 o->data[o->length] = '\0';
805 static void b_reset(o_string *o)
809 if (o->data != NULL) *o->data = '\0';
812 static void b_free(o_string *o)
820 /* My analysis of quoting semantics tells me that state information
821 * is associated with a destination, not a source.
823 static int b_addqchr(o_string *o, int ch, int quote)
825 if (quote && strchr("*?[\\",ch)) {
827 rc = b_addchr(o, '\\');
830 return b_addchr(o, ch);
833 /* belongs in utility.c */
834 static char *simple_itoa(unsigned int i)
836 /* 21 digits plus null terminator, good for 64-bit or smaller ints */
837 static char local[22];
838 char *p = &local[21];
847 static int b_adduint(o_string *o, unsigned int i)
850 char *p = simple_itoa(i);
851 /* no escape checking necessary */
852 do r=b_addchr(o, *p++); while (r==0 && *p);
856 static int static_get(struct in_str *i)
859 if (ch=='\0') return EOF;
863 static int static_peek(struct in_str *i)
868 static inline void cmdedit_set_initial_prompt(void)
870 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
879 static inline void setup_prompt_string(int promptmode, char **prompt_str)
881 debug_printf("setup_prompt_string %d ",promptmode);
882 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
883 /* Set up the prompt */
884 if (promptmode == 1) {
886 PS1=xmalloc(strlen(cwd)+4);
887 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
893 *prompt_str = (promptmode==1)? PS1 : PS2;
895 debug_printf("result %s\n",*prompt_str);
898 static void get_user_input(struct in_str *i)
901 static char the_command[BUFSIZ];
903 setup_prompt_string(i->promptmode, &prompt_str);
904 #ifdef CONFIG_FEATURE_COMMAND_EDITING
906 ** enable command line editing only while a command line
907 ** is actually being read; otherwise, we'll end up bequeathing
908 ** atexit() handlers and other unwanted stuff to our
909 ** child processes (rob@sysgo.de)
911 cmdedit_read_input(prompt_str, the_command);
913 fputs(prompt_str, stdout);
915 the_command[0]=fgetc(i->file);
922 /* This is the magic location that prints prompts
923 * and gets data back from the user */
924 static int file_get(struct in_str *i)
929 /* If there is data waiting, eat it up */
933 /* need to double check i->file because we might be doing something
934 * more complicated by now, like sourcing or substituting. */
935 if (i->__promptme && interactive && i->file == stdin) {
936 while(! i->p || (interactive && strlen(i->p)==0) ) {
948 debug_printf("b_getch: got a %d\n", ch);
950 if (ch == '\n') i->__promptme=1;
954 /* All the callers guarantee this routine will never be
955 * used right after a newline, so prompting is not needed.
957 static int file_peek(struct in_str *i)
962 i->peek_buf[0] = fgetc(i->file);
963 i->peek_buf[1] = '\0';
965 debug_printf("b_peek: got a %d\n", *i->p);
970 static void setup_file_in_str(struct in_str *i, FILE *f)
980 static void setup_string_in_str(struct in_str *i, const char *s)
982 i->peek = static_peek;
989 static void mark_open(int fd)
991 struct close_me *new = xmalloc(sizeof(struct close_me));
993 new->next = close_me_head;
997 static void mark_closed(int fd)
999 struct close_me *tmp;
1000 if (close_me_head == NULL || close_me_head->fd != fd)
1001 bb_error_msg_and_die("corrupt close_me");
1002 tmp = close_me_head;
1003 close_me_head = close_me_head->next;
1007 static void close_all(void)
1010 for (c=close_me_head; c; c=c->next) {
1013 close_me_head = NULL;
1016 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1017 * and stderr if they are redirected. */
1018 static int setup_redirects(struct child_prog *prog, int squirrel[])
1021 struct redir_struct *redir;
1023 for (redir=prog->redirects; redir; redir=redir->next) {
1024 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1025 /* something went wrong in the parse. Pretend it didn't happen */
1028 if (redir->dup == -1) {
1029 mode=redir_table[redir->type].mode;
1030 openfd = open(redir->word.gl_pathv[0], mode, 0666);
1032 /* this could get lost if stderr has been redirected, but
1033 bash and ash both lose it as well (though zsh doesn't!) */
1034 bb_perror_msg("error opening %s", redir->word.gl_pathv[0]);
1038 openfd = redir->dup;
1041 if (openfd != redir->fd) {
1042 if (squirrel && redir->fd < 3) {
1043 squirrel[redir->fd] = dup(redir->fd);
1048 dup2(openfd, redir->fd);
1049 if (redir->dup == -1)
1057 static void restore_redirects(int squirrel[])
1060 for (i=0; i<3; i++) {
1063 /* No error checking. I sure wouldn't know what
1064 * to do with an error if I found one! */
1072 /* XXX no exit() here. If you don't exec, use _exit instead.
1073 * The at_exit handlers apparently confuse the calling process,
1074 * in particular stdin handling. Not sure why? */
1075 static void pseudo_exec(struct child_prog *child)
1079 const struct built_in_command *x;
1081 for (i=0; is_assignment(child->argv[i]); i++) {
1082 debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1083 p = insert_var_value(child->argv[i]);
1085 if (p != child->argv[i]) free(p);
1087 child->argv+=i; /* XXX this hack isn't so horrible, since we are about
1088 to exit, and therefore don't need to keep data
1089 structures consistent for free() use. */
1090 /* If a variable is assigned in a forest, and nobody listens,
1091 * was it ever really set?
1093 if (child->argv[0] == NULL) {
1094 _exit(EXIT_SUCCESS);
1098 * Check if the command matches any of the builtins.
1099 * Depending on context, this might be redundant. But it's
1100 * easier to waste a few CPU cycles than it is to figure out
1101 * if this is one of those cases.
1103 for (x = bltins; x->cmd; x++) {
1104 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1105 debug_printf("builtin exec %s\n", child->argv[0]);
1106 rcode = x->function(child);
1112 /* Check if the command matches any busybox internal commands
1114 * FIXME: This feature is not 100% safe, since
1115 * BusyBox is not fully reentrant, so we have no guarantee the things
1116 * from the .bss are still zeroed, or that things from .data are still
1117 * at their defaults. We could exec ourself from /proc/self/exe, but I
1118 * really dislike relying on /proc for things. We could exec ourself
1119 * from global_argv[0], but if we are in a chroot, we may not be able
1120 * to find ourself... */
1121 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1124 char** argv_l=child->argv;
1125 char *name = child->argv[0];
1127 /* Count argc for use in a second... */
1128 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1130 debug_printf("running applet %s\n", name);
1131 run_applet_by_name(name, argc_l, child->argv);
1134 debug_printf("exec of %s\n",child->argv[0]);
1135 execvp(child->argv[0],child->argv);
1136 bb_perror_msg("couldn't exec: %s",child->argv[0]);
1138 } else if (child->group) {
1139 debug_printf("runtime nesting to group\n");
1140 interactive=0; /* crucial!!!! */
1141 rcode = run_list_real(child->group);
1142 /* OK to leak memory by not calling free_pipe_list,
1143 * since this process is about to exit */
1146 /* Can happen. See what bash does with ">foo" by itself. */
1147 debug_printf("trying to pseudo_exec null command\n");
1148 _exit(EXIT_SUCCESS);
1152 static void insert_bg_job(struct pipe *pi)
1154 struct pipe *thejob;
1156 /* Linear search for the ID of the job to use */
1158 for (thejob = job_list; thejob; thejob = thejob->next)
1159 if (thejob->jobid >= pi->jobid)
1160 pi->jobid = thejob->jobid + 1;
1162 /* add thejob to the list of running jobs */
1164 thejob = job_list = xmalloc(sizeof(*thejob));
1166 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1167 thejob->next = xmalloc(sizeof(*thejob));
1168 thejob = thejob->next;
1171 /* physically copy the struct job */
1172 memcpy(thejob, pi, sizeof(struct pipe));
1173 thejob->next = NULL;
1174 thejob->running_progs = thejob->num_progs;
1175 thejob->stopped_progs = 0;
1176 thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1178 //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
1180 char *bar=thejob->text;
1181 char **foo=pi->progs[0].argv;
1182 while(foo && *foo) {
1183 bar += sprintf(bar, "%s ", *foo++);
1187 /* we don't wait for background thejobs to return -- append it
1188 to the list of backgrounded thejobs and leave it alone */
1189 printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1190 last_bg_pid = thejob->progs[0].pid;
1191 last_jobid = thejob->jobid;
1194 /* remove a backgrounded job */
1195 static void remove_bg_job(struct pipe *pi)
1197 struct pipe *prev_pipe;
1199 if (pi == job_list) {
1200 job_list = pi->next;
1202 prev_pipe = job_list;
1203 while (prev_pipe->next != pi)
1204 prev_pipe = prev_pipe->next;
1205 prev_pipe->next = pi->next;
1208 last_jobid = job_list->jobid;
1212 pi->stopped_progs = 0;
1217 /* Checks to see if any processes have exited -- if they
1218 have, figure out why and see if a job has completed */
1219 static int checkjobs(struct pipe* fg_pipe)
1227 attributes = WUNTRACED;
1228 if (fg_pipe==NULL) {
1229 attributes |= WNOHANG;
1232 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1235 for (i=0; i < fg_pipe->num_progs; i++) {
1236 if (fg_pipe->progs[i].pid == childpid) {
1237 if (i==fg_pipe->num_progs-1)
1238 rcode=WEXITSTATUS(status);
1239 (fg_pipe->num_progs)--;
1245 for (pi = job_list; pi; pi = pi->next) {
1247 while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1250 if (prognum < pi->num_progs)
1255 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1259 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1261 pi->running_progs--;
1262 pi->progs[prognum].pid = 0;
1264 if (!pi->running_progs) {
1265 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1270 pi->stopped_progs++;
1271 pi->progs[prognum].is_stopped = 1;
1274 /* Printing this stuff is a pain, since it tends to
1275 * overwrite the prompt an inconveinient moments. So
1277 if (pi->stopped_progs == pi->num_progs) {
1278 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1284 if (childpid == -1 && errno != ECHILD)
1285 bb_perror_msg("waitpid");
1287 /* move the shell to the foreground */
1288 //if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
1289 // bb_perror_msg("tcsetpgrp-2");
1293 /* Figure out our controlling tty, checking in order stderr,
1294 * stdin, and stdout. If check_pgrp is set, also check that
1295 * we belong to the foreground process group associated with
1296 * that tty. The value of shell_terminal is needed in order to call
1297 * tcsetpgrp(shell_terminal, ...); */
1299 static void controlling_tty(int check_pgrp)
1303 if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1304 && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1305 && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1306 goto shell_terminal_error;
1308 if (check_pgrp && curpgrp != getpgid(0))
1309 goto shell_terminal_error;
1313 shell_terminal_error:
1314 shell_terminal = -1;
1319 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1320 * to finish. See checkjobs().
1322 * return code is normally -1, when the caller has to wait for children
1323 * to finish to determine the exit status of the pipe. If the pipe
1324 * is a simple builtin command, however, the action is done by the
1325 * time run_pipe_real returns, and the exit code is provided as the
1328 * The input of the pipe is always stdin, the output is always
1329 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1330 * because it tries to avoid running the command substitution in
1331 * subshell, when that is in fact necessary. The subshell process
1332 * now has its stdout directed to the input of the appropriate pipe,
1333 * so this routine is noticeably simpler.
1335 static int run_pipe_real(struct pipe *pi)
1338 int nextin, nextout;
1339 int pipefds[2]; /* pipefds[0] is for reading */
1340 struct child_prog *child;
1341 const struct built_in_command *x;
1347 /* Check if this is a simple builtin (not part of a pipe).
1348 * Builtins within pipes have to fork anyway, and are handled in
1349 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1351 if (pi->num_progs == 1) child = & (pi->progs[0]);
1352 if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1353 int squirrel[] = {-1, -1, -1};
1355 debug_printf("non-subshell grouping\n");
1356 setup_redirects(child, squirrel);
1357 /* XXX could we merge code with following builtin case,
1358 * by creating a pseudo builtin that calls run_list_real? */
1359 rcode = run_list_real(child->group);
1360 restore_redirects(squirrel);
1362 } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1363 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1364 if (i!=0 && child->argv[i]==NULL) {
1365 /* assignments, but no command: set the local environment */
1366 for (i=0; child->argv[i]!=NULL; i++) {
1368 /* Ok, this case is tricky. We have to decide if this is a
1369 * local variable, or an already exported variable. If it is
1370 * already exported, we have to export the new value. If it is
1371 * not exported, we need only set this as a local variable.
1372 * This junk is all to decide whether or not to export this
1376 name = bb_xstrdup(child->argv[i]);
1377 debug_printf("Local environment set: %s\n", name);
1378 value = strchr(name, '=');
1381 if ( get_local_var(name)) {
1385 p = insert_var_value(child->argv[i]);
1386 set_local_var(p, export_me);
1387 if (p != child->argv[i]) free(p);
1389 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1391 for (i = 0; is_assignment(child->argv[i]); i++) {
1392 p = insert_var_value(child->argv[i]);
1394 if (p != child->argv[i]) {
1402 str = make_string((child->argv + i));
1403 parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1405 return last_return_code;
1407 for (x = bltins; x->cmd; x++) {
1408 if (strcmp(child->argv[i], x->cmd) == 0 ) {
1409 int squirrel[] = {-1, -1, -1};
1411 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1412 debug_printf("magic exec\n");
1413 setup_redirects(child,NULL);
1414 return EXIT_SUCCESS;
1416 debug_printf("builtin inline %s\n", child->argv[0]);
1417 /* XXX setup_redirects acts on file descriptors, not FILEs.
1418 * This is perfect for work that comes after exec().
1419 * Is it really safe for inline use? Experimentally,
1420 * things seem to work with glibc. */
1421 setup_redirects(child, squirrel);
1422 child->argv+=i; /* XXX horrible hack */
1423 rcode = x->function(child);
1424 child->argv-=i; /* XXX restore hack so free() can work right */
1425 restore_redirects(squirrel);
1431 for (i = 0; i < pi->num_progs; i++) {
1432 child = & (pi->progs[i]);
1434 /* pipes are inserted between pairs of commands */
1435 if ((i + 1) < pi->num_progs) {
1436 if (pipe(pipefds)<0) bb_perror_msg_and_die("pipe");
1437 nextout = pipefds[1];
1443 /* XXX test for failed fork()? */
1444 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
1445 if (!(child->pid = fork()))
1447 if (!(child->pid = vfork()))
1450 /* Set the handling for job control signals back to the default. */
1451 signal(SIGINT, SIG_DFL);
1452 signal(SIGQUIT, SIG_DFL);
1453 signal(SIGTERM, SIG_DFL);
1454 signal(SIGTSTP, SIG_DFL);
1455 signal(SIGTTIN, SIG_DFL);
1456 signal(SIGTTOU, SIG_DFL);
1457 signal(SIGCHLD, SIG_DFL);
1469 if (pipefds[0]!=-1) {
1470 close(pipefds[0]); /* opposite end of our output pipe */
1473 /* Like bash, explicit redirects override pipes,
1474 * and the pipe fd is available for dup'ing. */
1475 setup_redirects(child,NULL);
1477 if (interactive && pi->followup!=PIPE_BG) {
1478 /* If we (the child) win the race, put ourselves in the process
1479 * group whose leader is the first process in this pipe. */
1481 pi->pgrp = getpid();
1483 if (setpgid(0, pi->pgrp) == 0) {
1484 tcsetpgrp(2, pi->pgrp);
1492 /* put our child in the process group whose leader is the
1493 first process in this pipe */
1495 pi->pgrp = child->pid;
1497 /* Don't check for errors. The child may be dead already,
1498 * in which case setpgid returns error code EACCES. */
1499 setpgid(child->pid, pi->pgrp);
1506 /* If there isn't another process, nextin is garbage
1507 but it doesn't matter */
1508 nextin = pipefds[0];
1513 static int run_list_real(struct pipe *pi)
1515 char *save_name = NULL;
1517 char **save_list = NULL;
1521 int rcode=0, flag_skip=1;
1522 int flag_restore = 0;
1523 int if_code=0, next_if_code=0; /* need double-buffer to handle elif */
1524 reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1525 /* check syntax for "for" */
1526 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1527 if ((rpipe->r_mode == RES_IN ||
1528 rpipe->r_mode == RES_FOR) &&
1529 (rpipe->next == NULL)) {
1533 if ((rpipe->r_mode == RES_IN &&
1534 (rpipe->next->r_mode == RES_IN &&
1535 rpipe->next->progs->argv != NULL))||
1536 (rpipe->r_mode == RES_FOR &&
1537 rpipe->next->r_mode != RES_IN)) {
1542 for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1543 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1544 pi->r_mode == RES_FOR) {
1552 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);
1553 if (rmode == skip_more_in_this_rmode && flag_skip) {
1554 if (pi->followup == PIPE_SEQ) flag_skip=0;
1558 skip_more_in_this_rmode = RES_XXXX;
1559 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1560 if (rmode == RES_THEN && if_code) continue;
1561 if (rmode == RES_ELSE && !if_code) continue;
1562 if (rmode == RES_ELIF && !if_code) break;
1563 if (rmode == RES_FOR && pi->num_progs) {
1565 /* if no variable values after "in" we skip "for" */
1566 if (!pi->next->progs->argv) continue;
1567 /* create list of variable values */
1568 list = make_list_in(pi->next->progs->argv,
1569 pi->progs->argv[0]);
1571 save_name = pi->progs->argv[0];
1572 pi->progs->argv[0] = NULL;
1576 free(pi->progs->argv[0]);
1580 pi->progs->argv[0] = save_name;
1581 pi->progs->glob_result.gl_pathv[0] =
1585 /* insert new value from list for variable */
1586 if (pi->progs->argv[0])
1587 free(pi->progs->argv[0]);
1588 pi->progs->argv[0] = *list++;
1589 pi->progs->glob_result.gl_pathv[0] =
1593 if (rmode == RES_IN) continue;
1594 if (rmode == RES_DO) {
1595 if (!flag_rep) continue;
1597 if ((rmode == RES_DONE)) {
1604 if (pi->num_progs == 0) continue;
1605 save_num_progs = pi->num_progs; /* save number of programs */
1606 rcode = run_pipe_real(pi);
1607 debug_printf("run_pipe_real returned %d\n",rcode);
1609 /* We only ran a builtin: rcode was set by the return value
1610 * of run_pipe_real(), and we don't need to wait for anything. */
1611 } else if (pi->followup==PIPE_BG) {
1612 /* XXX check bash's behavior with nontrivial pipes */
1613 /* XXX compute jobid */
1614 /* XXX what does bash do with attempts to background builtins? */
1616 rcode = EXIT_SUCCESS;
1619 /* move the new process group into the foreground */
1620 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1621 bb_perror_msg("tcsetpgrp-3");
1622 rcode = checkjobs(pi);
1623 /* move the shell to the foreground */
1624 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1625 bb_perror_msg("tcsetpgrp-4");
1627 rcode = checkjobs(pi);
1629 debug_printf("checkjobs returned %d\n",rcode);
1631 last_return_code=rcode;
1632 pi->num_progs = save_num_progs; /* restore number of programs */
1633 if ( rmode == RES_IF || rmode == RES_ELIF )
1634 next_if_code=rcode; /* can be overwritten a number of times */
1635 if (rmode == RES_WHILE)
1636 flag_rep = !last_return_code;
1637 if (rmode == RES_UNTIL)
1638 flag_rep = last_return_code;
1639 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1640 (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1641 skip_more_in_this_rmode=rmode;
1647 /* broken, of course, but OK for testing */
1648 static char *indenter(int i)
1650 static char blanks[]=" ";
1651 return &blanks[sizeof(blanks)-i-1];
1654 /* return code is the exit status of the pipe */
1655 static int free_pipe(struct pipe *pi, int indent)
1658 struct child_prog *child;
1659 struct redir_struct *r, *rnext;
1660 int a, i, ret_code=0;
1661 char *ind = indenter(indent);
1663 if (pi->stopped_progs > 0)
1665 final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1666 for (i=0; i<pi->num_progs; i++) {
1667 child = &pi->progs[i];
1668 final_printf("%s command %d:\n",ind,i);
1670 for (a=0,p=child->argv; *p; a++,p++) {
1671 final_printf("%s argv[%d] = %s\n",ind,a,*p);
1673 globfree(&child->glob_result);
1675 } else if (child->group) {
1676 final_printf("%s begin group (subshell:%d)\n",ind, child->subshell);
1677 ret_code = free_pipe_list(child->group,indent+3);
1678 final_printf("%s end group\n",ind);
1680 final_printf("%s (nil)\n",ind);
1682 for (r=child->redirects; r; r=rnext) {
1683 final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1685 /* guard against the case >$FOO, where foo is unset or blank */
1686 if (r->word.gl_pathv) {
1687 final_printf(" %s\n", *r->word.gl_pathv);
1691 final_printf("&%d\n", r->dup);
1696 child->redirects=NULL;
1698 free(pi->progs); /* children are an array, they get freed all at once */
1703 static int free_pipe_list(struct pipe *head, int indent)
1705 int rcode=0; /* if list has no members */
1706 struct pipe *pi, *next;
1707 char *ind = indenter(indent);
1708 for (pi=head; pi; pi=next) {
1709 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1710 rcode = free_pipe(pi, indent);
1711 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1719 /* Select which version we will use */
1720 static int run_list(struct pipe *pi)
1724 rcode = run_list_real(pi);
1726 /* free_pipe_list has the side effect of clearing memory
1727 * In the long run that function can be merged with run_list_real,
1728 * but doing that now would hobble the debugging effort. */
1729 free_pipe_list(pi,0);
1733 /* The API for glob is arguably broken. This routine pushes a non-matching
1734 * string into the output structure, removing non-backslashed backslashes.
1735 * If someone can prove me wrong, by performing this function within the
1736 * original glob(3) api, feel free to rewrite this routine into oblivion.
1737 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1738 * XXX broken if the last character is '\\', check that before calling.
1740 static int globhack(const char *src, int flags, glob_t *pglob)
1745 for (cnt=1, s=src; s && *s; s++) {
1746 if (*s == '\\') s++;
1750 if (!dest) return GLOB_NOSPACE;
1751 if (!(flags & GLOB_APPEND)) {
1752 pglob->gl_pathv=NULL;
1757 pathc = ++pglob->gl_pathc;
1758 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1759 if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
1760 pglob->gl_pathv[pathc-1]=dest;
1761 pglob->gl_pathv[pathc]=NULL;
1762 for (s=src; s && *s; s++, dest++) {
1763 if (*s == '\\') s++;
1770 /* XXX broken if the last character is '\\', check that before calling */
1771 static int glob_needed(const char *s)
1774 if (*s == '\\') s++;
1775 if (strchr("*[?",*s)) return 1;
1781 static void globprint(glob_t *pglob)
1784 debug_printf("glob_t at %p:\n", pglob);
1785 debug_printf(" gl_pathc=%d gl_pathv=%p gl_offs=%d gl_flags=%d\n",
1786 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
1787 for (i=0; i<pglob->gl_pathc; i++)
1788 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
1789 pglob->gl_pathv[i], pglob->gl_pathv[i]);
1793 static int xglob(o_string *dest, int flags, glob_t *pglob)
1797 /* short-circuit for null word */
1798 /* we can code this better when the debug_printf's are gone */
1799 if (dest->length == 0) {
1800 if (dest->nonnull) {
1801 /* bash man page calls this an "explicit" null */
1802 gr = globhack(dest->data, flags, pglob);
1803 debug_printf("globhack returned %d\n",gr);
1807 } else if (glob_needed(dest->data)) {
1808 gr = glob(dest->data, flags, NULL, pglob);
1809 debug_printf("glob returned %d\n",gr);
1810 if (gr == GLOB_NOMATCH) {
1811 /* quote removal, or more accurately, backslash removal */
1812 gr = globhack(dest->data, flags, pglob);
1813 debug_printf("globhack returned %d\n",gr);
1816 gr = globhack(dest->data, flags, pglob);
1817 debug_printf("globhack returned %d\n",gr);
1819 if (gr == GLOB_NOSPACE)
1820 bb_error_msg_and_die("out of memory during glob");
1821 if (gr != 0) { /* GLOB_ABORTED ? */
1822 bb_error_msg("glob(3) error %d",gr);
1824 /* globprint(glob_target); */
1828 /* This is used to get/check local shell variables */
1829 static char *get_local_var(const char *s)
1831 struct variables *cur;
1835 for (cur = top_vars; cur; cur=cur->next)
1836 if(strcmp(cur->name, s)==0)
1841 /* This is used to set local shell variables
1842 flg_export==0 if only local (not exporting) variable
1843 flg_export==1 if "new" exporting environ
1844 flg_export>1 if current startup environ (not call putenv()) */
1845 static int set_local_var(const char *s, int flg_export)
1849 struct variables *cur;
1853 /* Assume when we enter this function that we are already in
1854 * NAME=VALUE format. So the first order of business is to
1855 * split 's' on the '=' into 'name' and 'value' */
1856 value = strchr(name, '=');
1857 if (value==0 && ++value==0) {
1863 for(cur = top_vars; cur; cur = cur->next) {
1864 if(strcmp(cur->name, name)==0)
1869 if(strcmp(cur->value, value)==0) {
1870 if(flg_export>0 && cur->flg_export==0)
1871 cur->flg_export=flg_export;
1875 if(cur->flg_read_only) {
1876 bb_error_msg("%s: readonly variable", name);
1879 if(flg_export>0 || cur->flg_export>1)
1883 cur->value = strdup(value);
1887 cur = malloc(sizeof(struct variables));
1891 cur->name = strdup(name);
1892 if(cur->name == 0) {
1896 struct variables *bottom = top_vars;
1897 cur->value = strdup(value);
1899 cur->flg_export = flg_export;
1900 cur->flg_read_only = 0;
1901 while(bottom->next) bottom=bottom->next;
1907 if(result==0 && cur->flg_export==1) {
1909 result = putenv(name);
1912 if(result>0) /* equivalent to previous set */
1918 static void unset_local_var(const char *name)
1920 struct variables *cur;
1923 for (cur = top_vars; cur; cur=cur->next) {
1924 if(strcmp(cur->name, name)==0)
1928 struct variables *next = top_vars;
1929 if(cur->flg_read_only) {
1930 bb_error_msg("%s: readonly variable", name);
1934 unsetenv(cur->name);
1937 while (next->next != cur)
1939 next->next = cur->next;
1946 static int is_assignment(const char *s)
1948 if (s==NULL || !isalpha(*s)) return 0;
1950 while(isalnum(*s) || *s=='_') ++s;
1954 /* the src parameter allows us to peek forward to a possible &n syntax
1955 * for file descriptor duplication, e.g., "2>&1".
1956 * Return code is 0 normally, 1 if a syntax error is detected in src.
1957 * Resource errors (in xmalloc) cause the process to exit */
1958 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1959 struct in_str *input)
1961 struct child_prog *child=ctx->child;
1962 struct redir_struct *redir = child->redirects;
1963 struct redir_struct *last_redir=NULL;
1965 /* Create a new redir_struct and drop it onto the end of the linked list */
1970 redir = xmalloc(sizeof(struct redir_struct));
1972 redir->word.gl_pathv=NULL;
1974 last_redir->next=redir;
1976 child->redirects=redir;
1980 redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
1982 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1984 /* Check for a '2>&1' type redirect */
1985 redir->dup = redirect_dup_num(input);
1986 if (redir->dup == -2) return 1; /* syntax error */
1987 if (redir->dup != -1) {
1988 /* Erik had a check here that the file descriptor in question
1989 * is legit; I postpone that to "run time"
1990 * A "-" representation of "close me" shows up as a -3 here */
1991 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
1993 /* We do _not_ try to open the file that src points to,
1994 * since we need to return and let src be expanded first.
1995 * Set ctx->pending_redirect, so we know what to do at the
1996 * end of the next parsed word.
1998 ctx->pending_redirect = redir;
2003 static struct pipe *new_pipe(void) {
2005 pi = xmalloc(sizeof(struct pipe));
2009 pi->followup = 0; /* invalid */
2013 static void initialize_context(struct p_context *ctx)
2016 ctx->pending_redirect=NULL;
2018 ctx->list_head=new_pipe();
2019 ctx->pipe=ctx->list_head;
2023 done_command(ctx); /* creates the memory for working child */
2026 /* normal return is 0
2027 * if a reserved word is found, and processed, return 1
2028 * should handle if, then, elif, else, fi, for, while, until, do, done.
2029 * case, function, and select are obnoxious, save those for later.
2031 static int reserved_word(o_string *dest, struct p_context *ctx)
2033 struct reserved_combo {
2038 /* Mostly a list of accepted follow-up reserved words.
2039 * FLAG_END means we are done with the sequence, and are ready
2040 * to turn the compound list into a command.
2041 * FLAG_START means the word must start a new compound list.
2043 static struct reserved_combo reserved_list[] = {
2044 { "if", RES_IF, FLAG_THEN | FLAG_START },
2045 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2046 { "elif", RES_ELIF, FLAG_THEN },
2047 { "else", RES_ELSE, FLAG_FI },
2048 { "fi", RES_FI, FLAG_END },
2049 { "for", RES_FOR, FLAG_IN | FLAG_START },
2050 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2051 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2052 { "in", RES_IN, FLAG_DO },
2053 { "do", RES_DO, FLAG_DONE },
2054 { "done", RES_DONE, FLAG_END }
2056 struct reserved_combo *r;
2057 for (r=reserved_list;
2058 #define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
2059 r<reserved_list+NRES; r++) {
2060 if (strcmp(dest->data, r->literal) == 0) {
2061 debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2062 if (r->flag & FLAG_START) {
2063 struct p_context *new = xmalloc(sizeof(struct p_context));
2064 debug_printf("push stack\n");
2065 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2072 *new = *ctx; /* physical copy */
2073 initialize_context(ctx);
2075 } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2082 ctx->old_flag = r->flag;
2083 if (ctx->old_flag & FLAG_END) {
2084 struct p_context *old;
2085 debug_printf("pop stack\n");
2086 done_pipe(ctx,PIPE_SEQ);
2088 old->child->group = ctx->list_head;
2089 old->child->subshell = 0;
2090 *ctx = *old; /* physical copy */
2100 /* normal return is 0.
2101 * Syntax or xglob errors return 1. */
2102 static int done_word(o_string *dest, struct p_context *ctx)
2104 struct child_prog *child=ctx->child;
2105 glob_t *glob_target;
2108 debug_printf("done_word: %s %p\n", dest->data, child);
2109 if (dest->length == 0 && !dest->nonnull) {
2110 debug_printf(" true null, ignored\n");
2113 if (ctx->pending_redirect) {
2114 glob_target = &ctx->pending_redirect->word;
2118 return 1; /* syntax error, groups and arglists don't mix */
2120 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2121 debug_printf("checking %s for reserved-ness\n",dest->data);
2122 if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2124 glob_target = &child->glob_result;
2125 if (child->argv) flags |= GLOB_APPEND;
2127 gr = xglob(dest, flags, glob_target);
2128 if (gr != 0) return 1;
2131 if (ctx->pending_redirect) {
2132 ctx->pending_redirect=NULL;
2133 if (glob_target->gl_pathc != 1) {
2134 bb_error_msg("ambiguous redirect");
2138 child->argv = glob_target->gl_pathv;
2140 if (ctx->w == RES_FOR) {
2141 done_word(dest,ctx);
2142 done_pipe(ctx,PIPE_SEQ);
2147 /* The only possible error here is out of memory, in which case
2149 static int done_command(struct p_context *ctx)
2151 /* The child is really already in the pipe structure, so
2152 * advance the pipe counter and make a new, null child.
2153 * Only real trickiness here is that the uncommitted
2154 * child structure, to which ctx->child points, is not
2155 * counted in pi->num_progs. */
2156 struct pipe *pi=ctx->pipe;
2157 struct child_prog *prog=ctx->child;
2159 if (prog && prog->group == NULL
2160 && prog->argv == NULL
2161 && prog->redirects == NULL) {
2162 debug_printf("done_command: skipping null command\n");
2166 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2168 debug_printf("done_command: initializing\n");
2170 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2172 prog = pi->progs + pi->num_progs;
2173 prog->redirects = NULL;
2175 prog->is_stopped = 0;
2177 prog->glob_result.gl_pathv = NULL;
2181 prog->type = ctx->type;
2183 /* but ctx->pipe and ctx->list_head remain unchanged */
2187 static int done_pipe(struct p_context *ctx, pipe_style type)
2190 done_command(ctx); /* implicit closure of previous command */
2191 debug_printf("done_pipe, type %d\n", type);
2192 ctx->pipe->followup = type;
2193 ctx->pipe->r_mode = ctx->w;
2195 ctx->pipe->next = new_p;
2198 done_command(ctx); /* set up new pipe to accept commands */
2202 /* peek ahead in the in_str to find out if we have a "&n" construct,
2203 * as in "2>&1", that represents duplicating a file descriptor.
2204 * returns either -2 (syntax error), -1 (no &), or the number found.
2206 static int redirect_dup_num(struct in_str *input)
2210 if (ch != '&') return -1;
2212 b_getch(input); /* get the & */
2216 return -3; /* "-" represents "close me" */
2218 while (isdigit(ch)) {
2226 bb_error_msg("ambiguous redirect");
2230 /* If a redirect is immediately preceded by a number, that number is
2231 * supposed to tell which file descriptor to redirect. This routine
2232 * looks for such preceding numbers. In an ideal world this routine
2233 * needs to handle all the following classes of redirects...
2234 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2235 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2236 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2237 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2238 * A -1 output from this program means no valid number was found, so the
2239 * caller should use the appropriate default for this redirection.
2241 static int redirect_opt_num(o_string *o)
2245 if (o->length==0) return -1;
2246 for(num=0; num<o->length; num++) {
2247 if (!isdigit(*(o->data+num))) {
2251 /* reuse num (and save an int) */
2257 static FILE *generate_stream_from_list(struct pipe *head)
2261 int pid, channel[2];
2262 if (pipe(channel)<0) bb_perror_msg_and_die("pipe");
2263 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
2269 bb_perror_msg_and_die("fork");
2270 } else if (pid==0) {
2272 if (channel[1] != 1) {
2277 #define SURROGATE "surrogate response"
2278 write(1,SURROGATE,sizeof(SURROGATE));
2279 _exit(run_list(head));
2281 _exit(run_list_real(head)); /* leaks memory */
2284 debug_printf("forked child %d\n",pid);
2286 pf = fdopen(channel[0],"r");
2287 debug_printf("pipe on FILE *%p\n",pf);
2289 free_pipe_list(head,0);
2290 pf=popen("echo surrogate response","r");
2291 debug_printf("started fake pipe on FILE *%p\n",pf);
2296 /* this version hacked for testing purposes */
2297 /* return code is exit status of the process that is run. */
2298 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2301 o_string result=NULL_O_STRING;
2302 struct p_context inner;
2304 struct in_str pipe_str;
2305 initialize_context(&inner);
2307 /* recursion to generate command */
2308 retcode = parse_stream(&result, &inner, input, subst_end);
2309 if (retcode != 0) return retcode; /* syntax error or EOF */
2310 done_word(&result, &inner);
2311 done_pipe(&inner, PIPE_SEQ);
2314 p=generate_stream_from_list(inner.list_head);
2315 if (p==NULL) return 1;
2316 mark_open(fileno(p));
2317 setup_file_in_str(&pipe_str, p);
2319 /* now send results of command back into original context */
2320 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2321 /* XXX In case of a syntax error, should we try to kill the child?
2322 * That would be tough to do right, so just read until EOF. */
2324 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2327 debug_printf("done reading from pipe, pclose()ing\n");
2328 /* This is the step that wait()s for the child. Should be pretty
2329 * safe, since we just read an EOF from its stdout. We could try
2330 * to better, by using wait(), and keeping track of background jobs
2331 * at the same time. That would be a lot of work, and contrary
2332 * to the KISS philosophy of this program. */
2333 mark_closed(fileno(p));
2335 free_pipe_list(inner.list_head,0);
2336 debug_printf("pclosed, retcode=%d\n",retcode);
2337 /* XXX this process fails to trim a single trailing newline */
2341 static int parse_group(o_string *dest, struct p_context *ctx,
2342 struct in_str *input, int ch)
2345 struct p_context sub;
2346 struct child_prog *child = ctx->child;
2349 return 1; /* syntax error, groups and arglists don't mix */
2351 initialize_context(&sub);
2353 case '(': endch=')'; child->subshell=1; break;
2354 case '{': endch='}'; break;
2355 default: syntax(); /* really logic error */
2357 rcode=parse_stream(dest,&sub,input,endch);
2358 done_word(dest,&sub); /* finish off the final word in the subcontext */
2359 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2360 child->group = sub.list_head;
2362 /* child remains "open", available for possible redirects */
2365 /* basically useful version until someone wants to get fancier,
2366 * see the bash man page under "Parameter Expansion" */
2367 static char *lookup_param(char *src)
2373 p = get_local_var(src);
2378 /* return code: 0 for OK, 1 for syntax error */
2379 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2383 int ch = input->peek(input); /* first character after the $ */
2384 debug_printf("handle_dollar: ch=%c\n",ch);
2386 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2388 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2392 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2393 } else if (isdigit(ch)) {
2394 i = ch-'0'; /* XXX is $0 special? */
2395 if (i<global_argc) {
2396 parse_string(dest, ctx, global_argv[i]); /* recursion */
2399 } else switch (ch) {
2401 b_adduint(dest,getpid());
2405 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2409 b_adduint(dest,last_return_code);
2413 b_adduint(dest,global_argc ? global_argc-1 : 0);
2417 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2420 /* XXX maybe someone will try to escape the '}' */
2421 while(ch=b_getch(input),ch!=EOF && ch!='}') {
2428 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2432 process_command_subs(dest, ctx, input, ')');
2436 for (i=1; i<global_argc; i++) {
2437 parse_string(dest, ctx, global_argv[i]);
2438 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2444 /* still unhandled, but should be eventually */
2445 bb_error_msg("unhandled syntax: $%c",ch);
2449 b_addqchr(dest,'$',dest->quote);
2451 /* Eat the character if the flag was set. If the compiler
2452 * is smart enough, we could substitute "b_getch(input);"
2453 * for all the "advance = 1;" above, and also end up with
2454 * a nice size-optimized program. Hah! That'll be the day.
2456 if (advance) b_getch(input);
2460 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2463 setup_string_in_str(&foo, src);
2464 return parse_stream(dest, ctx, &foo, '\0');
2467 /* return code is 0 for normal exit, 1 for syntax error */
2468 int parse_stream(o_string *dest, struct p_context *ctx,
2469 struct in_str *input, int end_trigger)
2473 redir_type redir_style;
2476 /* Only double-quote state is handled in the state variable dest->quote.
2477 * A single-quote triggers a bypass of the main loop until its mate is
2478 * found. When recursing, quote state is passed in via dest->quote. */
2480 debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2481 while ((ch=b_getch(input))!=EOF) {
2483 next = (ch == '\n') ? 0 : b_peek(input);
2484 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2485 ch,ch,m,dest->quote);
2486 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2487 b_addqchr(dest, ch, dest->quote);
2489 if (m==2) { /* unquoted IFS */
2490 if (done_word(dest, ctx)) {
2493 /* If we aren't performing a substitution, treat a newline as a
2494 * command separator. */
2495 if (end_trigger != '\0' && ch=='\n')
2496 done_pipe(ctx,PIPE_SEQ);
2498 if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2499 debug_printf("leaving parse_stream (triggered)\n");
2504 /* Yahoo! Time to run with it! */
2505 done_pipe(ctx,PIPE_SEQ);
2506 run_list(ctx->list_head);
2507 initialize_context(ctx);
2510 if (m!=2) switch (ch) {
2512 if (dest->length == 0 && !dest->quote) {
2513 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2515 b_addqchr(dest, ch, dest->quote);
2523 b_addqchr(dest, '\\', dest->quote);
2524 b_addqchr(dest, b_getch(input), dest->quote);
2527 if (handle_dollar(dest, ctx, input)!=0) return 1;
2531 while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2541 dest->quote = !dest->quote;
2544 process_command_subs(dest, ctx, input, '`');
2547 redir_fd = redirect_opt_num(dest);
2548 done_word(dest, ctx);
2549 redir_style=REDIRECT_OVERWRITE;
2551 redir_style=REDIRECT_APPEND;
2553 } else if (next == '(') {
2554 syntax(); /* until we support >(list) Process Substitution */
2557 setup_redirect(ctx, redir_fd, redir_style, input);
2560 redir_fd = redirect_opt_num(dest);
2561 done_word(dest, ctx);
2562 redir_style=REDIRECT_INPUT;
2564 redir_style=REDIRECT_HEREIS;
2566 } else if (next == '>') {
2567 redir_style=REDIRECT_IO;
2569 } else if (next == '(') {
2570 syntax(); /* until we support <(list) Process Substitution */
2573 setup_redirect(ctx, redir_fd, redir_style, input);
2576 done_word(dest, ctx);
2577 done_pipe(ctx,PIPE_SEQ);
2580 done_word(dest, ctx);
2583 done_pipe(ctx,PIPE_AND);
2585 done_pipe(ctx,PIPE_BG);
2589 done_word(dest, ctx);
2592 done_pipe(ctx,PIPE_OR);
2594 /* we could pick up a file descriptor choice here
2595 * with redirect_opt_num(), but bash doesn't do it.
2596 * "echo foo 2| cat" yields "foo 2". */
2602 if (parse_group(dest, ctx, input, ch)!=0) return 1;
2606 syntax(); /* Proper use of this character caught by end_trigger */
2610 syntax(); /* this is really an internal logic error */
2615 /* complain if quote? No, maybe we just finished a command substitution
2616 * that was quoted. Example:
2617 * $ echo "`cat foo` plus more"
2618 * and we just got the EOF generated by the subshell that ran "cat foo"
2619 * The only real complaint is if we got an EOF when end_trigger != '\0',
2620 * that is, we were really supposed to get end_trigger, and never got
2621 * one before the EOF. Can't use the standard "syntax error" return code,
2622 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
2623 debug_printf("leaving parse_stream (EOF)\n");
2624 if (end_trigger != '\0') return -1;
2628 static void mapset(const unsigned char *set, int code)
2630 const unsigned char *s;
2631 for (s=set; *s; s++) map[*s] = code;
2634 static void update_ifs_map(void)
2636 /* char *ifs and char map[256] are both globals. */
2637 ifs = getenv("IFS");
2638 if (ifs == NULL) ifs=" \t\n";
2639 /* Precompute a list of 'flow through' behavior so it can be treated
2640 * quickly up front. Computation is necessary because of IFS.
2641 * Special case handling of IFS == " \t\n" is not implemented.
2642 * The map[] array only really needs two bits each, and on most machines
2643 * that would be faster because of the reduced L1 cache footprint.
2645 memset(map,0,sizeof(map)); /* most characters flow through always */
2646 mapset("\\$'\"`", 3); /* never flow through */
2647 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2648 mapset(ifs, 2); /* also flow through if quoted */
2651 /* most recursion does not come through here, the exception is
2652 * from builtin_source() */
2653 int parse_stream_outer(struct in_str *inp, int flag)
2656 struct p_context ctx;
2657 o_string temp=NULL_O_STRING;
2661 initialize_context(&ctx);
2663 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
2665 rcode = parse_stream(&temp, &ctx, inp, '\n');
2666 if (rcode != 1 && ctx.old_flag != 0) {
2669 if (rcode != 1 && ctx.old_flag == 0) {
2670 done_word(&temp, &ctx);
2671 done_pipe(&ctx,PIPE_SEQ);
2672 run_list(ctx.list_head);
2674 if (ctx.old_flag != 0) {
2681 free_pipe_list(ctx.list_head,0);
2684 } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
2688 static int parse_string_outer(const char *s, int flag)
2690 struct in_str input;
2691 setup_string_in_str(&input, s);
2692 return parse_stream_outer(&input, flag);
2695 static int parse_file_outer(FILE *f)
2698 struct in_str input;
2699 setup_file_in_str(&input, f);
2700 rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
2704 /* Make sure we have a controlling tty. If we get started under a job
2705 * aware app (like bash for example), make sure we are now in charge so
2706 * we don't fight over who gets the foreground */
2707 static void setup_job_control(void)
2709 static pid_t shell_pgrp;
2710 /* Loop until we are in the foreground. */
2711 while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
2712 kill (- shell_pgrp, SIGTTIN);
2714 /* Ignore interactive and job-control signals. */
2715 signal(SIGINT, SIG_IGN);
2716 signal(SIGQUIT, SIG_IGN);
2717 signal(SIGTERM, SIG_IGN);
2718 signal(SIGTSTP, SIG_IGN);
2719 signal(SIGTTIN, SIG_IGN);
2720 signal(SIGTTOU, SIG_IGN);
2721 signal(SIGCHLD, SIG_IGN);
2723 /* Put ourselves in our own process group. */
2725 shell_pgrp = getpid ();
2726 setpgid (shell_pgrp, shell_pgrp);
2728 /* Grab control of the terminal. */
2729 tcsetpgrp(shell_terminal, shell_pgrp);
2732 int hush_main(int argc, char **argv)
2738 /* XXX what should these be while sourcing /etc/profile? */
2742 /* (re?) initialize globals. Sometimes hush_main() ends up calling
2743 * hush_main(), therefore we cannot rely on the BSS to zero out this
2744 * stuff. Reset these to 0 every time. */
2746 /* map[] is taken care of with call to update_ifs_map() */
2749 close_me_head = NULL;
2754 /* Initialize some more globals to non-zero values */
2756 #ifdef CONFIG_FEATURE_COMMAND_EDITING
2757 cmdedit_set_initial_prompt();
2763 /* initialize our shell local variables with the values
2764 * currently living in the environment */
2767 set_local_var(*e, 2); /* without call putenv() */
2770 last_return_code=EXIT_SUCCESS;
2773 if (argv[0] && argv[0][0] == '-') {
2774 debug_printf("\nsourcing /etc/profile\n");
2775 if ((input = fopen("/etc/profile", "r")) != NULL) {
2776 mark_open(fileno(input));
2777 parse_file_outer(input);
2778 mark_closed(fileno(input));
2784 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2788 global_argv = argv+optind;
2789 global_argc = argc-optind;
2790 opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
2802 fprintf(stderr, "Usage: sh [FILE]...\n"
2803 " or: sh -c command [args]...\n\n");
2810 /* A shell is interactive if the `-i' flag was given, or if all of
2811 * the following conditions are met:
2813 * no arguments remaining or the -s flag given
2814 * standard input is a terminal
2815 * standard output is a terminal
2816 * Refer to Posix.2, the description of the `sh' utility. */
2817 if (argv[optind]==NULL && input==stdin &&
2818 isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
2822 debug_printf("\ninteractive=%d\n", interactive);
2824 /* Looks like they want an interactive shell */
2825 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
2826 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
2827 printf( "Enter 'help' for a list of built-in commands.\n\n");
2829 setup_job_control();
2832 if (argv[optind]==NULL) {
2833 opt=parse_file_outer(stdin);
2837 debug_printf("\nrunning script '%s'\n", argv[optind]);
2838 global_argv = argv+optind;
2839 global_argc = argc-optind;
2840 input = bb_xfopen(argv[optind], "r");
2841 opt = parse_file_outer(input);
2843 #ifdef CONFIG_FEATURE_CLEAN_UP
2845 if (cwd && cwd != bb_msg_unknown)
2848 struct variables *cur, *tmp;
2849 for(cur = top_vars; cur; cur = tmp) {
2851 if (!cur->flg_read_only) {
2861 return(opt?opt:last_return_code);
2864 static char *insert_var_value(char *inp)
2866 int res_str_len = 0;
2869 char *p, *p1, *res_str = NULL;
2871 while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
2874 res_str = xrealloc(res_str, (res_str_len + len));
2875 strncpy((res_str + res_str_len), inp, len);
2879 p = strchr(inp, SPECIAL_VAR_SYMBOL);
2881 if ((p1 = lookup_param(inp))) {
2882 len = res_str_len + strlen(p1);
2883 res_str = xrealloc(res_str, (1 + len));
2884 strcpy((res_str + res_str_len), p1);
2887 *p = SPECIAL_VAR_SYMBOL;
2892 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
2893 strcpy((res_str + res_str_len), inp);
2894 while ((p = strchr(res_str, '\n'))) {
2898 return (res_str == NULL) ? inp : res_str;
2901 static char **make_list_in(char **inp, char *name)
2904 int name_len = strlen(name);
2909 /* create list of variable values */
2910 list = xmalloc(sizeof(*list));
2911 for (i = 0; inp[i]; i++) {
2912 p3 = insert_var_value(inp[i]);
2919 if ((p2 = strchr(p1, ' '))) {
2925 /* we use n + 2 in realloc for list,because we add
2926 * new element and then we will add NULL element */
2927 list = xrealloc(list, sizeof(*list) * (n + 2));
2928 list[n] = xmalloc(2 + name_len + len);
2929 strcpy(list[n], name);
2930 strcat(list[n], "=");
2931 strncat(list[n], p1, len);
2932 list[n++][name_len + len + 1] = '\0';
2935 if (p3 != inp[i]) free(p3);
2941 /* Make new string for parser */
2942 static char * make_string(char ** inp)
2949 for (n = 0; inp[n]; n++) {
2950 p = insert_var_value(inp[n]);
2951 str = xrealloc(str, (len + strlen(p)));
2958 len = strlen(str) + 3;
2959 if (p != inp[n]) free(p);
2962 *(str + len) = '\n';
2963 *(str + len + 1) = '\0';