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) 1999-2003 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 struct {int mode; int default_fd; 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 */
248 unsigned int global_argc;
249 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 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
266 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 char *cmd; /* name */
301 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 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 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 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 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 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1128 /* Following discussions from November 2000 on the busybox mailing
1129 * list, the default configuration, (without
1130 * bb_get_last_path_component()) lets the user force use of an
1131 * external command by specifying the full (with slashes) filename.
1132 * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN, then applets
1133 * _aways_ override external commands, so if you want to run
1134 * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1135 * filesystem and is _not_ busybox. Some systems may want this,
1137 name = bb_get_last_path_component(name);
1139 /* Count argc for use in a second... */
1140 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1142 debug_printf("running applet %s\n", name);
1143 run_applet_by_name(name, argc_l, child->argv);
1146 debug_printf("exec of %s\n",child->argv[0]);
1147 execvp(child->argv[0],child->argv);
1148 bb_perror_msg("couldn't exec: %s",child->argv[0]);
1150 } else if (child->group) {
1151 debug_printf("runtime nesting to group\n");
1152 interactive=0; /* crucial!!!! */
1153 rcode = run_list_real(child->group);
1154 /* OK to leak memory by not calling free_pipe_list,
1155 * since this process is about to exit */
1158 /* Can happen. See what bash does with ">foo" by itself. */
1159 debug_printf("trying to pseudo_exec null command\n");
1160 _exit(EXIT_SUCCESS);
1164 static void insert_bg_job(struct pipe *pi)
1166 struct pipe *thejob;
1168 /* Linear search for the ID of the job to use */
1170 for (thejob = job_list; thejob; thejob = thejob->next)
1171 if (thejob->jobid >= pi->jobid)
1172 pi->jobid = thejob->jobid + 1;
1174 /* add thejob to the list of running jobs */
1176 thejob = job_list = xmalloc(sizeof(*thejob));
1178 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1179 thejob->next = xmalloc(sizeof(*thejob));
1180 thejob = thejob->next;
1183 /* physically copy the struct job */
1184 memcpy(thejob, pi, sizeof(struct pipe));
1185 thejob->next = NULL;
1186 thejob->running_progs = thejob->num_progs;
1187 thejob->stopped_progs = 0;
1188 thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1190 //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
1192 char *bar=thejob->text;
1193 char **foo=pi->progs[0].argv;
1194 while(foo && *foo) {
1195 bar += sprintf(bar, "%s ", *foo++);
1199 /* we don't wait for background thejobs to return -- append it
1200 to the list of backgrounded thejobs and leave it alone */
1201 printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1202 last_bg_pid = thejob->progs[0].pid;
1203 last_jobid = thejob->jobid;
1206 /* remove a backgrounded job */
1207 static void remove_bg_job(struct pipe *pi)
1209 struct pipe *prev_pipe;
1211 if (pi == job_list) {
1212 job_list = pi->next;
1214 prev_pipe = job_list;
1215 while (prev_pipe->next != pi)
1216 prev_pipe = prev_pipe->next;
1217 prev_pipe->next = pi->next;
1220 last_jobid = job_list->jobid;
1224 pi->stopped_progs = 0;
1229 /* Checks to see if any processes have exited -- if they
1230 have, figure out why and see if a job has completed */
1231 static int checkjobs(struct pipe* fg_pipe)
1239 attributes = WUNTRACED;
1240 if (fg_pipe==NULL) {
1241 attributes |= WNOHANG;
1244 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1247 for (i=0; i < fg_pipe->num_progs; i++) {
1248 if (fg_pipe->progs[i].pid == childpid) {
1249 if (i==fg_pipe->num_progs-1)
1250 rcode=WEXITSTATUS(status);
1251 (fg_pipe->num_progs)--;
1257 for (pi = job_list; pi; pi = pi->next) {
1259 while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1262 if (prognum < pi->num_progs)
1267 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1271 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1273 pi->running_progs--;
1274 pi->progs[prognum].pid = 0;
1276 if (!pi->running_progs) {
1277 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1282 pi->stopped_progs++;
1283 pi->progs[prognum].is_stopped = 1;
1286 /* Printing this stuff is a pain, since it tends to
1287 * overwrite the prompt an inconveinient moments. So
1289 if (pi->stopped_progs == pi->num_progs) {
1290 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1296 if (childpid == -1 && errno != ECHILD)
1297 bb_perror_msg("waitpid");
1299 /* move the shell to the foreground */
1300 //if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
1301 // bb_perror_msg("tcsetpgrp-2");
1305 /* Figure out our controlling tty, checking in order stderr,
1306 * stdin, and stdout. If check_pgrp is set, also check that
1307 * we belong to the foreground process group associated with
1308 * that tty. The value of shell_terminal is needed in order to call
1309 * tcsetpgrp(shell_terminal, ...); */
1310 void controlling_tty(int check_pgrp)
1314 if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1315 && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1316 && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1317 goto shell_terminal_error;
1319 if (check_pgrp && curpgrp != getpgid(0))
1320 goto shell_terminal_error;
1324 shell_terminal_error:
1325 shell_terminal = -1;
1329 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1330 * to finish. See checkjobs().
1332 * return code is normally -1, when the caller has to wait for children
1333 * to finish to determine the exit status of the pipe. If the pipe
1334 * is a simple builtin command, however, the action is done by the
1335 * time run_pipe_real returns, and the exit code is provided as the
1338 * The input of the pipe is always stdin, the output is always
1339 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1340 * because it tries to avoid running the command substitution in
1341 * subshell, when that is in fact necessary. The subshell process
1342 * now has its stdout directed to the input of the appropriate pipe,
1343 * so this routine is noticeably simpler.
1345 static int run_pipe_real(struct pipe *pi)
1348 int nextin, nextout;
1349 int pipefds[2]; /* pipefds[0] is for reading */
1350 struct child_prog *child;
1351 struct built_in_command *x;
1357 /* Check if this is a simple builtin (not part of a pipe).
1358 * Builtins within pipes have to fork anyway, and are handled in
1359 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1361 if (pi->num_progs == 1) child = & (pi->progs[0]);
1362 if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1363 int squirrel[] = {-1, -1, -1};
1365 debug_printf("non-subshell grouping\n");
1366 setup_redirects(child, squirrel);
1367 /* XXX could we merge code with following builtin case,
1368 * by creating a pseudo builtin that calls run_list_real? */
1369 rcode = run_list_real(child->group);
1370 restore_redirects(squirrel);
1372 } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1373 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1374 if (i!=0 && child->argv[i]==NULL) {
1375 /* assignments, but no command: set the local environment */
1376 for (i=0; child->argv[i]!=NULL; i++) {
1378 /* Ok, this case is tricky. We have to decide if this is a
1379 * local variable, or an already exported variable. If it is
1380 * already exported, we have to export the new value. If it is
1381 * not exported, we need only set this as a local variable.
1382 * This junk is all to decide whether or not to export this
1386 name = bb_xstrdup(child->argv[i]);
1387 debug_printf("Local environment set: %s\n", name);
1388 value = strchr(name, '=');
1391 if ( get_local_var(name)) {
1395 p = insert_var_value(child->argv[i]);
1396 set_local_var(p, export_me);
1397 if (p != child->argv[i]) free(p);
1399 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1401 for (i = 0; is_assignment(child->argv[i]); i++) {
1402 p = insert_var_value(child->argv[i]);
1404 if (p != child->argv[i]) {
1412 str = make_string((child->argv + i));
1413 parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1415 return last_return_code;
1417 for (x = bltins; x->cmd; x++) {
1418 if (strcmp(child->argv[i], x->cmd) == 0 ) {
1419 int squirrel[] = {-1, -1, -1};
1421 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1422 debug_printf("magic exec\n");
1423 setup_redirects(child,NULL);
1424 return EXIT_SUCCESS;
1426 debug_printf("builtin inline %s\n", child->argv[0]);
1427 /* XXX setup_redirects acts on file descriptors, not FILEs.
1428 * This is perfect for work that comes after exec().
1429 * Is it really safe for inline use? Experimentally,
1430 * things seem to work with glibc. */
1431 setup_redirects(child, squirrel);
1432 child->argv+=i; /* XXX horrible hack */
1433 rcode = x->function(child);
1434 child->argv-=i; /* XXX restore hack so free() can work right */
1435 restore_redirects(squirrel);
1441 for (i = 0; i < pi->num_progs; i++) {
1442 child = & (pi->progs[i]);
1444 /* pipes are inserted between pairs of commands */
1445 if ((i + 1) < pi->num_progs) {
1446 if (pipe(pipefds)<0) bb_perror_msg_and_die("pipe");
1447 nextout = pipefds[1];
1453 /* XXX test for failed fork()? */
1454 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
1455 if (!(child->pid = fork()))
1457 if (!(child->pid = vfork()))
1460 /* Set the handling for job control signals back to the default. */
1461 signal(SIGINT, SIG_DFL);
1462 signal(SIGQUIT, SIG_DFL);
1463 signal(SIGTERM, SIG_DFL);
1464 signal(SIGTSTP, SIG_DFL);
1465 signal(SIGTTIN, SIG_DFL);
1466 signal(SIGTTOU, SIG_DFL);
1467 signal(SIGCHLD, SIG_DFL);
1479 if (pipefds[0]!=-1) {
1480 close(pipefds[0]); /* opposite end of our output pipe */
1483 /* Like bash, explicit redirects override pipes,
1484 * and the pipe fd is available for dup'ing. */
1485 setup_redirects(child,NULL);
1487 if (interactive && pi->followup!=PIPE_BG) {
1488 /* If we (the child) win the race, put ourselves in the process
1489 * group whose leader is the first process in this pipe. */
1491 pi->pgrp = getpid();
1493 if (setpgid(0, pi->pgrp) == 0) {
1494 tcsetpgrp(2, pi->pgrp);
1502 /* put our child in the process group whose leader is the
1503 first process in this pipe */
1505 pi->pgrp = child->pid;
1507 /* Don't check for errors. The child may be dead already,
1508 * in which case setpgid returns error code EACCES. */
1509 setpgid(child->pid, pi->pgrp);
1516 /* If there isn't another process, nextin is garbage
1517 but it doesn't matter */
1518 nextin = pipefds[0];
1523 static int run_list_real(struct pipe *pi)
1525 char *save_name = NULL;
1527 char **save_list = NULL;
1531 int rcode=0, flag_skip=1;
1532 int flag_restore = 0;
1533 int if_code=0, next_if_code=0; /* need double-buffer to handle elif */
1534 reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1535 /* check syntax for "for" */
1536 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1537 if ((rpipe->r_mode == RES_IN ||
1538 rpipe->r_mode == RES_FOR) &&
1539 (rpipe->next == NULL)) {
1543 if ((rpipe->r_mode == RES_IN &&
1544 (rpipe->next->r_mode == RES_IN &&
1545 rpipe->next->progs->argv != NULL))||
1546 (rpipe->r_mode == RES_FOR &&
1547 rpipe->next->r_mode != RES_IN)) {
1552 for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1553 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1554 pi->r_mode == RES_FOR) {
1562 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);
1563 if (rmode == skip_more_in_this_rmode && flag_skip) {
1564 if (pi->followup == PIPE_SEQ) flag_skip=0;
1568 skip_more_in_this_rmode = RES_XXXX;
1569 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1570 if (rmode == RES_THEN && if_code) continue;
1571 if (rmode == RES_ELSE && !if_code) continue;
1572 if (rmode == RES_ELIF && !if_code) continue;
1573 if (rmode == RES_FOR && pi->num_progs) {
1575 /* if no variable values after "in" we skip "for" */
1576 if (!pi->next->progs->argv) continue;
1577 /* create list of variable values */
1578 list = make_list_in(pi->next->progs->argv,
1579 pi->progs->argv[0]);
1581 save_name = pi->progs->argv[0];
1582 pi->progs->argv[0] = NULL;
1586 free(pi->progs->argv[0]);
1590 pi->progs->argv[0] = save_name;
1591 pi->progs->glob_result.gl_pathv[0] =
1595 /* insert new value from list for variable */
1596 if (pi->progs->argv[0])
1597 free(pi->progs->argv[0]);
1598 pi->progs->argv[0] = *list++;
1599 pi->progs->glob_result.gl_pathv[0] =
1603 if (rmode == RES_IN) continue;
1604 if (rmode == RES_DO) {
1605 if (!flag_rep) continue;
1607 if ((rmode == RES_DONE)) {
1614 if (pi->num_progs == 0) continue;
1615 save_num_progs = pi->num_progs; /* save number of programs */
1616 rcode = run_pipe_real(pi);
1617 debug_printf("run_pipe_real returned %d\n",rcode);
1619 /* We only ran a builtin: rcode was set by the return value
1620 * of run_pipe_real(), and we don't need to wait for anything. */
1621 } else if (pi->followup==PIPE_BG) {
1622 /* XXX check bash's behavior with nontrivial pipes */
1623 /* XXX compute jobid */
1624 /* XXX what does bash do with attempts to background builtins? */
1626 rcode = EXIT_SUCCESS;
1629 /* move the new process group into the foreground */
1630 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1631 bb_perror_msg("tcsetpgrp-3");
1632 rcode = checkjobs(pi);
1633 /* move the shell to the foreground */
1634 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1635 bb_perror_msg("tcsetpgrp-4");
1637 rcode = checkjobs(pi);
1639 debug_printf("checkjobs returned %d\n",rcode);
1641 last_return_code=rcode;
1642 pi->num_progs = save_num_progs; /* restore number of programs */
1643 if ( rmode == RES_IF || rmode == RES_ELIF )
1644 next_if_code=rcode; /* can be overwritten a number of times */
1645 if (rmode == RES_WHILE)
1646 flag_rep = !last_return_code;
1647 if (rmode == RES_UNTIL)
1648 flag_rep = last_return_code;
1649 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1650 (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1651 skip_more_in_this_rmode=rmode;
1657 /* broken, of course, but OK for testing */
1658 static char *indenter(int i)
1660 static char blanks[]=" ";
1661 return &blanks[sizeof(blanks)-i-1];
1664 /* return code is the exit status of the pipe */
1665 static int free_pipe(struct pipe *pi, int indent)
1668 struct child_prog *child;
1669 struct redir_struct *r, *rnext;
1670 int a, i, ret_code=0;
1671 char *ind = indenter(indent);
1673 if (pi->stopped_progs > 0)
1675 final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1676 for (i=0; i<pi->num_progs; i++) {
1677 child = &pi->progs[i];
1678 final_printf("%s command %d:\n",ind,i);
1680 for (a=0,p=child->argv; *p; a++,p++) {
1681 final_printf("%s argv[%d] = %s\n",ind,a,*p);
1683 globfree(&child->glob_result);
1685 } else if (child->group) {
1686 final_printf("%s begin group (subshell:%d)\n",ind, child->subshell);
1687 ret_code = free_pipe_list(child->group,indent+3);
1688 final_printf("%s end group\n",ind);
1690 final_printf("%s (nil)\n",ind);
1692 for (r=child->redirects; r; r=rnext) {
1693 final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1695 /* guard against the case >$FOO, where foo is unset or blank */
1696 if (r->word.gl_pathv) {
1697 final_printf(" %s\n", *r->word.gl_pathv);
1701 final_printf("&%d\n", r->dup);
1706 child->redirects=NULL;
1708 free(pi->progs); /* children are an array, they get freed all at once */
1713 static int free_pipe_list(struct pipe *head, int indent)
1715 int rcode=0; /* if list has no members */
1716 struct pipe *pi, *next;
1717 char *ind = indenter(indent);
1718 for (pi=head; pi; pi=next) {
1719 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1720 rcode = free_pipe(pi, indent);
1721 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1729 /* Select which version we will use */
1730 static int run_list(struct pipe *pi)
1734 rcode = run_list_real(pi);
1736 /* free_pipe_list has the side effect of clearing memory
1737 * In the long run that function can be merged with run_list_real,
1738 * but doing that now would hobble the debugging effort. */
1739 free_pipe_list(pi,0);
1743 /* The API for glob is arguably broken. This routine pushes a non-matching
1744 * string into the output structure, removing non-backslashed backslashes.
1745 * If someone can prove me wrong, by performing this function within the
1746 * original glob(3) api, feel free to rewrite this routine into oblivion.
1747 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1748 * XXX broken if the last character is '\\', check that before calling.
1750 static int globhack(const char *src, int flags, glob_t *pglob)
1755 for (cnt=1, s=src; s && *s; s++) {
1756 if (*s == '\\') s++;
1760 if (!dest) return GLOB_NOSPACE;
1761 if (!(flags & GLOB_APPEND)) {
1762 pglob->gl_pathv=NULL;
1767 pathc = ++pglob->gl_pathc;
1768 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1769 if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
1770 pglob->gl_pathv[pathc-1]=dest;
1771 pglob->gl_pathv[pathc]=NULL;
1772 for (s=src; s && *s; s++, dest++) {
1773 if (*s == '\\') s++;
1780 /* XXX broken if the last character is '\\', check that before calling */
1781 static int glob_needed(const char *s)
1784 if (*s == '\\') s++;
1785 if (strchr("*[?",*s)) return 1;
1791 static void globprint(glob_t *pglob)
1794 debug_printf("glob_t at %p:\n", pglob);
1795 debug_printf(" gl_pathc=%d gl_pathv=%p gl_offs=%d gl_flags=%d\n",
1796 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
1797 for (i=0; i<pglob->gl_pathc; i++)
1798 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
1799 pglob->gl_pathv[i], pglob->gl_pathv[i]);
1803 static int xglob(o_string *dest, int flags, glob_t *pglob)
1807 /* short-circuit for null word */
1808 /* we can code this better when the debug_printf's are gone */
1809 if (dest->length == 0) {
1810 if (dest->nonnull) {
1811 /* bash man page calls this an "explicit" null */
1812 gr = globhack(dest->data, flags, pglob);
1813 debug_printf("globhack returned %d\n",gr);
1817 } else if (glob_needed(dest->data)) {
1818 gr = glob(dest->data, flags, NULL, pglob);
1819 debug_printf("glob returned %d\n",gr);
1820 if (gr == GLOB_NOMATCH) {
1821 /* quote removal, or more accurately, backslash removal */
1822 gr = globhack(dest->data, flags, pglob);
1823 debug_printf("globhack returned %d\n",gr);
1826 gr = globhack(dest->data, flags, pglob);
1827 debug_printf("globhack returned %d\n",gr);
1829 if (gr == GLOB_NOSPACE)
1830 bb_error_msg_and_die("out of memory during glob");
1831 if (gr != 0) { /* GLOB_ABORTED ? */
1832 bb_error_msg("glob(3) error %d",gr);
1834 /* globprint(glob_target); */
1838 /* This is used to get/check local shell variables */
1839 static char *get_local_var(const char *s)
1841 struct variables *cur;
1845 for (cur = top_vars; cur; cur=cur->next)
1846 if(strcmp(cur->name, s)==0)
1851 /* This is used to set local shell variables
1852 flg_export==0 if only local (not exporting) variable
1853 flg_export==1 if "new" exporting environ
1854 flg_export>1 if current startup environ (not call putenv()) */
1855 static int set_local_var(const char *s, int flg_export)
1859 struct variables *cur;
1863 /* Assume when we enter this function that we are already in
1864 * NAME=VALUE format. So the first order of business is to
1865 * split 's' on the '=' into 'name' and 'value' */
1866 value = strchr(name, '=');
1867 if (value==0 && ++value==0) {
1873 for(cur = top_vars; cur; cur = cur->next) {
1874 if(strcmp(cur->name, name)==0)
1879 if(strcmp(cur->value, value)==0) {
1880 if(flg_export>0 && cur->flg_export==0)
1881 cur->flg_export=flg_export;
1885 if(cur->flg_read_only) {
1886 bb_error_msg("%s: readonly variable", name);
1889 if(flg_export>0 || cur->flg_export>1)
1893 cur->value = strdup(value);
1897 cur = malloc(sizeof(struct variables));
1901 cur->name = strdup(name);
1902 if(cur->name == 0) {
1906 struct variables *bottom = top_vars;
1907 cur->value = strdup(value);
1909 cur->flg_export = flg_export;
1910 cur->flg_read_only = 0;
1911 while(bottom->next) bottom=bottom->next;
1917 if(result==0 && cur->flg_export==1) {
1919 result = putenv(name);
1922 if(result>0) /* equivalent to previous set */
1928 static void unset_local_var(const char *name)
1930 struct variables *cur;
1933 for (cur = top_vars; cur; cur=cur->next) {
1934 if(strcmp(cur->name, name)==0)
1938 struct variables *next = top_vars;
1939 if(cur->flg_read_only) {
1940 bb_error_msg("%s: readonly variable", name);
1944 unsetenv(cur->name);
1947 while (next->next != cur)
1949 next->next = cur->next;
1956 static int is_assignment(const char *s)
1958 if (s==NULL || !isalpha(*s)) return 0;
1960 while(isalnum(*s) || *s=='_') ++s;
1964 /* the src parameter allows us to peek forward to a possible &n syntax
1965 * for file descriptor duplication, e.g., "2>&1".
1966 * Return code is 0 normally, 1 if a syntax error is detected in src.
1967 * Resource errors (in xmalloc) cause the process to exit */
1968 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1969 struct in_str *input)
1971 struct child_prog *child=ctx->child;
1972 struct redir_struct *redir = child->redirects;
1973 struct redir_struct *last_redir=NULL;
1975 /* Create a new redir_struct and drop it onto the end of the linked list */
1980 redir = xmalloc(sizeof(struct redir_struct));
1982 redir->word.gl_pathv=NULL;
1984 last_redir->next=redir;
1986 child->redirects=redir;
1990 redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
1992 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1994 /* Check for a '2>&1' type redirect */
1995 redir->dup = redirect_dup_num(input);
1996 if (redir->dup == -2) return 1; /* syntax error */
1997 if (redir->dup != -1) {
1998 /* Erik had a check here that the file descriptor in question
1999 * is legit; I postpone that to "run time"
2000 * A "-" representation of "close me" shows up as a -3 here */
2001 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2003 /* We do _not_ try to open the file that src points to,
2004 * since we need to return and let src be expanded first.
2005 * Set ctx->pending_redirect, so we know what to do at the
2006 * end of the next parsed word.
2008 ctx->pending_redirect = redir;
2013 struct pipe *new_pipe(void) {
2015 pi = xmalloc(sizeof(struct pipe));
2019 pi->followup = 0; /* invalid */
2023 static void initialize_context(struct p_context *ctx)
2026 ctx->pending_redirect=NULL;
2028 ctx->list_head=new_pipe();
2029 ctx->pipe=ctx->list_head;
2033 done_command(ctx); /* creates the memory for working child */
2036 /* normal return is 0
2037 * if a reserved word is found, and processed, return 1
2038 * should handle if, then, elif, else, fi, for, while, until, do, done.
2039 * case, function, and select are obnoxious, save those for later.
2041 int reserved_word(o_string *dest, struct p_context *ctx)
2043 struct reserved_combo {
2048 /* Mostly a list of accepted follow-up reserved words.
2049 * FLAG_END means we are done with the sequence, and are ready
2050 * to turn the compound list into a command.
2051 * FLAG_START means the word must start a new compound list.
2053 static struct reserved_combo reserved_list[] = {
2054 { "if", RES_IF, FLAG_THEN | FLAG_START },
2055 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2056 { "elif", RES_ELIF, FLAG_THEN },
2057 { "else", RES_ELSE, FLAG_FI },
2058 { "fi", RES_FI, FLAG_END },
2059 { "for", RES_FOR, FLAG_IN | FLAG_START },
2060 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2061 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2062 { "in", RES_IN, FLAG_DO },
2063 { "do", RES_DO, FLAG_DONE },
2064 { "done", RES_DONE, FLAG_END }
2066 struct reserved_combo *r;
2067 for (r=reserved_list;
2068 #define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
2069 r<reserved_list+NRES; r++) {
2070 if (strcmp(dest->data, r->literal) == 0) {
2071 debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2072 if (r->flag & FLAG_START) {
2073 struct p_context *new = xmalloc(sizeof(struct p_context));
2074 debug_printf("push stack\n");
2075 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2082 *new = *ctx; /* physical copy */
2083 initialize_context(ctx);
2085 } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2092 ctx->old_flag = r->flag;
2093 if (ctx->old_flag & FLAG_END) {
2094 struct p_context *old;
2095 debug_printf("pop stack\n");
2096 done_pipe(ctx,PIPE_SEQ);
2098 old->child->group = ctx->list_head;
2099 old->child->subshell = 0;
2100 *ctx = *old; /* physical copy */
2110 /* normal return is 0.
2111 * Syntax or xglob errors return 1. */
2112 static int done_word(o_string *dest, struct p_context *ctx)
2114 struct child_prog *child=ctx->child;
2115 glob_t *glob_target;
2118 debug_printf("done_word: %s %p\n", dest->data, child);
2119 if (dest->length == 0 && !dest->nonnull) {
2120 debug_printf(" true null, ignored\n");
2123 if (ctx->pending_redirect) {
2124 glob_target = &ctx->pending_redirect->word;
2128 return 1; /* syntax error, groups and arglists don't mix */
2130 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2131 debug_printf("checking %s for reserved-ness\n",dest->data);
2132 if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2134 glob_target = &child->glob_result;
2135 if (child->argv) flags |= GLOB_APPEND;
2137 gr = xglob(dest, flags, glob_target);
2138 if (gr != 0) return 1;
2141 if (ctx->pending_redirect) {
2142 ctx->pending_redirect=NULL;
2143 if (glob_target->gl_pathc != 1) {
2144 bb_error_msg("ambiguous redirect");
2148 child->argv = glob_target->gl_pathv;
2150 if (ctx->w == RES_FOR) {
2151 done_word(dest,ctx);
2152 done_pipe(ctx,PIPE_SEQ);
2157 /* The only possible error here is out of memory, in which case
2159 static int done_command(struct p_context *ctx)
2161 /* The child is really already in the pipe structure, so
2162 * advance the pipe counter and make a new, null child.
2163 * Only real trickiness here is that the uncommitted
2164 * child structure, to which ctx->child points, is not
2165 * counted in pi->num_progs. */
2166 struct pipe *pi=ctx->pipe;
2167 struct child_prog *prog=ctx->child;
2169 if (prog && prog->group == NULL
2170 && prog->argv == NULL
2171 && prog->redirects == NULL) {
2172 debug_printf("done_command: skipping null command\n");
2176 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2178 debug_printf("done_command: initializing\n");
2180 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2182 prog = pi->progs + pi->num_progs;
2183 prog->redirects = NULL;
2185 prog->is_stopped = 0;
2187 prog->glob_result.gl_pathv = NULL;
2191 prog->type = ctx->type;
2193 /* but ctx->pipe and ctx->list_head remain unchanged */
2197 static int done_pipe(struct p_context *ctx, pipe_style type)
2200 done_command(ctx); /* implicit closure of previous command */
2201 debug_printf("done_pipe, type %d\n", type);
2202 ctx->pipe->followup = type;
2203 ctx->pipe->r_mode = ctx->w;
2205 ctx->pipe->next = new_p;
2208 done_command(ctx); /* set up new pipe to accept commands */
2212 /* peek ahead in the in_str to find out if we have a "&n" construct,
2213 * as in "2>&1", that represents duplicating a file descriptor.
2214 * returns either -2 (syntax error), -1 (no &), or the number found.
2216 static int redirect_dup_num(struct in_str *input)
2220 if (ch != '&') return -1;
2222 b_getch(input); /* get the & */
2226 return -3; /* "-" represents "close me" */
2228 while (isdigit(ch)) {
2236 bb_error_msg("ambiguous redirect");
2240 /* If a redirect is immediately preceded by a number, that number is
2241 * supposed to tell which file descriptor to redirect. This routine
2242 * looks for such preceding numbers. In an ideal world this routine
2243 * needs to handle all the following classes of redirects...
2244 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2245 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2246 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2247 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2248 * A -1 output from this program means no valid number was found, so the
2249 * caller should use the appropriate default for this redirection.
2251 static int redirect_opt_num(o_string *o)
2255 if (o->length==0) return -1;
2256 for(num=0; num<o->length; num++) {
2257 if (!isdigit(*(o->data+num))) {
2261 /* reuse num (and save an int) */
2267 FILE *generate_stream_from_list(struct pipe *head)
2271 int pid, channel[2];
2272 if (pipe(channel)<0) bb_perror_msg_and_die("pipe");
2273 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
2279 bb_perror_msg_and_die("fork");
2280 } else if (pid==0) {
2282 if (channel[1] != 1) {
2287 #define SURROGATE "surrogate response"
2288 write(1,SURROGATE,sizeof(SURROGATE));
2289 _exit(run_list(head));
2291 _exit(run_list_real(head)); /* leaks memory */
2294 debug_printf("forked child %d\n",pid);
2296 pf = fdopen(channel[0],"r");
2297 debug_printf("pipe on FILE *%p\n",pf);
2299 free_pipe_list(head,0);
2300 pf=popen("echo surrogate response","r");
2301 debug_printf("started fake pipe on FILE *%p\n",pf);
2306 /* this version hacked for testing purposes */
2307 /* return code is exit status of the process that is run. */
2308 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2311 o_string result=NULL_O_STRING;
2312 struct p_context inner;
2314 struct in_str pipe_str;
2315 initialize_context(&inner);
2317 /* recursion to generate command */
2318 retcode = parse_stream(&result, &inner, input, subst_end);
2319 if (retcode != 0) return retcode; /* syntax error or EOF */
2320 done_word(&result, &inner);
2321 done_pipe(&inner, PIPE_SEQ);
2324 p=generate_stream_from_list(inner.list_head);
2325 if (p==NULL) return 1;
2326 mark_open(fileno(p));
2327 setup_file_in_str(&pipe_str, p);
2329 /* now send results of command back into original context */
2330 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2331 /* XXX In case of a syntax error, should we try to kill the child?
2332 * That would be tough to do right, so just read until EOF. */
2334 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2337 debug_printf("done reading from pipe, pclose()ing\n");
2338 /* This is the step that wait()s for the child. Should be pretty
2339 * safe, since we just read an EOF from its stdout. We could try
2340 * to better, by using wait(), and keeping track of background jobs
2341 * at the same time. That would be a lot of work, and contrary
2342 * to the KISS philosophy of this program. */
2343 mark_closed(fileno(p));
2345 free_pipe_list(inner.list_head,0);
2346 debug_printf("pclosed, retcode=%d\n",retcode);
2347 /* XXX this process fails to trim a single trailing newline */
2351 static int parse_group(o_string *dest, struct p_context *ctx,
2352 struct in_str *input, int ch)
2355 struct p_context sub;
2356 struct child_prog *child = ctx->child;
2359 return 1; /* syntax error, groups and arglists don't mix */
2361 initialize_context(&sub);
2363 case '(': endch=')'; child->subshell=1; break;
2364 case '{': endch='}'; break;
2365 default: syntax(); /* really logic error */
2367 rcode=parse_stream(dest,&sub,input,endch);
2368 done_word(dest,&sub); /* finish off the final word in the subcontext */
2369 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2370 child->group = sub.list_head;
2372 /* child remains "open", available for possible redirects */
2375 /* basically useful version until someone wants to get fancier,
2376 * see the bash man page under "Parameter Expansion" */
2377 static char *lookup_param(char *src)
2383 p = get_local_var(src);
2388 /* return code: 0 for OK, 1 for syntax error */
2389 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2393 int ch = input->peek(input); /* first character after the $ */
2394 debug_printf("handle_dollar: ch=%c\n",ch);
2396 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2398 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2402 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2403 } else if (isdigit(ch)) {
2404 i = ch-'0'; /* XXX is $0 special? */
2405 if (i<global_argc) {
2406 parse_string(dest, ctx, global_argv[i]); /* recursion */
2409 } else switch (ch) {
2411 b_adduint(dest,getpid());
2415 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2419 b_adduint(dest,last_return_code);
2423 b_adduint(dest,global_argc ? global_argc-1 : 0);
2427 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2430 /* XXX maybe someone will try to escape the '}' */
2431 while(ch=b_getch(input),ch!=EOF && ch!='}') {
2438 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2442 process_command_subs(dest, ctx, input, ')');
2446 for (i=1; i<global_argc; i++) {
2447 parse_string(dest, ctx, global_argv[i]);
2448 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2454 /* still unhandled, but should be eventually */
2455 bb_error_msg("unhandled syntax: $%c",ch);
2459 b_addqchr(dest,'$',dest->quote);
2461 /* Eat the character if the flag was set. If the compiler
2462 * is smart enough, we could substitute "b_getch(input);"
2463 * for all the "advance = 1;" above, and also end up with
2464 * a nice size-optimized program. Hah! That'll be the day.
2466 if (advance) b_getch(input);
2470 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2473 setup_string_in_str(&foo, src);
2474 return parse_stream(dest, ctx, &foo, '\0');
2477 /* return code is 0 for normal exit, 1 for syntax error */
2478 int parse_stream(o_string *dest, struct p_context *ctx,
2479 struct in_str *input, int end_trigger)
2483 redir_type redir_style;
2486 /* Only double-quote state is handled in the state variable dest->quote.
2487 * A single-quote triggers a bypass of the main loop until its mate is
2488 * found. When recursing, quote state is passed in via dest->quote. */
2490 debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2491 while ((ch=b_getch(input))!=EOF) {
2493 next = (ch == '\n') ? 0 : b_peek(input);
2494 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2495 ch,ch,m,dest->quote);
2496 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2497 b_addqchr(dest, ch, dest->quote);
2499 if (m==2) { /* unquoted IFS */
2500 if (done_word(dest, ctx)) {
2503 /* If we aren't performing a substitution, treat a newline as a
2504 * command separator. */
2505 if (end_trigger != '\0' && ch=='\n')
2506 done_pipe(ctx,PIPE_SEQ);
2508 if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2509 debug_printf("leaving parse_stream (triggered)\n");
2514 /* Yahoo! Time to run with it! */
2515 done_pipe(ctx,PIPE_SEQ);
2516 run_list(ctx->list_head);
2517 initialize_context(ctx);
2520 if (m!=2) switch (ch) {
2522 if (dest->length == 0 && !dest->quote) {
2523 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2525 b_addqchr(dest, ch, dest->quote);
2533 b_addqchr(dest, '\\', dest->quote);
2534 b_addqchr(dest, b_getch(input), dest->quote);
2537 if (handle_dollar(dest, ctx, input)!=0) return 1;
2541 while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2551 dest->quote = !dest->quote;
2554 process_command_subs(dest, ctx, input, '`');
2557 redir_fd = redirect_opt_num(dest);
2558 done_word(dest, ctx);
2559 redir_style=REDIRECT_OVERWRITE;
2561 redir_style=REDIRECT_APPEND;
2563 } else if (next == '(') {
2564 syntax(); /* until we support >(list) Process Substitution */
2567 setup_redirect(ctx, redir_fd, redir_style, input);
2570 redir_fd = redirect_opt_num(dest);
2571 done_word(dest, ctx);
2572 redir_style=REDIRECT_INPUT;
2574 redir_style=REDIRECT_HEREIS;
2576 } else if (next == '>') {
2577 redir_style=REDIRECT_IO;
2579 } else if (next == '(') {
2580 syntax(); /* until we support <(list) Process Substitution */
2583 setup_redirect(ctx, redir_fd, redir_style, input);
2586 done_word(dest, ctx);
2587 done_pipe(ctx,PIPE_SEQ);
2590 done_word(dest, ctx);
2593 done_pipe(ctx,PIPE_AND);
2595 done_pipe(ctx,PIPE_BG);
2599 done_word(dest, ctx);
2602 done_pipe(ctx,PIPE_OR);
2604 /* we could pick up a file descriptor choice here
2605 * with redirect_opt_num(), but bash doesn't do it.
2606 * "echo foo 2| cat" yields "foo 2". */
2612 if (parse_group(dest, ctx, input, ch)!=0) return 1;
2616 syntax(); /* Proper use of this character caught by end_trigger */
2620 syntax(); /* this is really an internal logic error */
2625 /* complain if quote? No, maybe we just finished a command substitution
2626 * that was quoted. Example:
2627 * $ echo "`cat foo` plus more"
2628 * and we just got the EOF generated by the subshell that ran "cat foo"
2629 * The only real complaint is if we got an EOF when end_trigger != '\0',
2630 * that is, we were really supposed to get end_trigger, and never got
2631 * one before the EOF. Can't use the standard "syntax error" return code,
2632 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
2633 debug_printf("leaving parse_stream (EOF)\n");
2634 if (end_trigger != '\0') return -1;
2638 void mapset(const unsigned char *set, int code)
2640 const unsigned char *s;
2641 for (s=set; *s; s++) map[*s] = code;
2644 void update_ifs_map(void)
2646 /* char *ifs and char map[256] are both globals. */
2647 ifs = getenv("IFS");
2648 if (ifs == NULL) ifs=" \t\n";
2649 /* Precompute a list of 'flow through' behavior so it can be treated
2650 * quickly up front. Computation is necessary because of IFS.
2651 * Special case handling of IFS == " \t\n" is not implemented.
2652 * The map[] array only really needs two bits each, and on most machines
2653 * that would be faster because of the reduced L1 cache footprint.
2655 memset(map,0,sizeof(map)); /* most characters flow through always */
2656 mapset("\\$'\"`", 3); /* never flow through */
2657 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2658 mapset(ifs, 2); /* also flow through if quoted */
2661 /* most recursion does not come through here, the exeception is
2662 * from builtin_source() */
2663 int parse_stream_outer(struct in_str *inp, int flag)
2666 struct p_context ctx;
2667 o_string temp=NULL_O_STRING;
2671 initialize_context(&ctx);
2673 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
2675 rcode = parse_stream(&temp, &ctx, inp, '\n');
2676 if (rcode != 1 && ctx.old_flag != 0) {
2679 if (rcode != 1 && ctx.old_flag == 0) {
2680 done_word(&temp, &ctx);
2681 done_pipe(&ctx,PIPE_SEQ);
2682 run_list(ctx.list_head);
2684 if (ctx.old_flag != 0) {
2691 free_pipe_list(ctx.list_head,0);
2694 } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
2698 static int parse_string_outer(const char *s, int flag)
2700 struct in_str input;
2701 setup_string_in_str(&input, s);
2702 return parse_stream_outer(&input, flag);
2705 static int parse_file_outer(FILE *f)
2708 struct in_str input;
2709 setup_file_in_str(&input, f);
2710 rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
2714 /* Make sure we have a controlling tty. If we get started under a job
2715 * aware app (like bash for example), make sure we are now in charge so
2716 * we don't fight over who gets the foreground */
2717 static void setup_job_control(void)
2719 static pid_t shell_pgrp;
2720 /* Loop until we are in the foreground. */
2721 while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
2722 kill (- shell_pgrp, SIGTTIN);
2724 /* Ignore interactive and job-control signals. */
2725 signal(SIGINT, SIG_IGN);
2726 signal(SIGQUIT, SIG_IGN);
2727 signal(SIGTERM, SIG_IGN);
2728 signal(SIGTSTP, SIG_IGN);
2729 signal(SIGTTIN, SIG_IGN);
2730 signal(SIGTTOU, SIG_IGN);
2731 signal(SIGCHLD, SIG_IGN);
2733 /* Put ourselves in our own process group. */
2735 shell_pgrp = getpid ();
2736 setpgid (shell_pgrp, shell_pgrp);
2738 /* Grab control of the terminal. */
2739 tcsetpgrp(shell_terminal, shell_pgrp);
2742 int hush_main(int argc, char **argv)
2748 /* XXX what should these be while sourcing /etc/profile? */
2752 /* (re?) initialize globals. Sometimes hush_main() ends up calling
2753 * hush_main(), therefore we cannot rely on the BSS to zero out this
2754 * stuff. Reset these to 0 every time. */
2756 /* map[] is taken care of with call to update_ifs_map() */
2759 close_me_head = NULL;
2764 /* Initialize some more globals to non-zero values */
2766 #ifdef CONFIG_FEATURE_COMMAND_EDITING
2767 cmdedit_set_initial_prompt();
2773 /* initialize our shell local variables with the values
2774 * currently living in the environment */
2777 set_local_var(*e, 2); /* without call putenv() */
2780 last_return_code=EXIT_SUCCESS;
2783 if (argv[0] && argv[0][0] == '-') {
2784 debug_printf("\nsourcing /etc/profile\n");
2785 if ((input = fopen("/etc/profile", "r")) != NULL) {
2786 mark_open(fileno(input));
2787 parse_file_outer(input);
2788 mark_closed(fileno(input));
2794 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2798 global_argv = argv+optind;
2799 global_argc = argc-optind;
2800 opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
2812 fprintf(stderr, "Usage: sh [FILE]...\n"
2813 " or: sh -c command [args]...\n\n");
2820 /* A shell is interactive if the `-i' flag was given, or if all of
2821 * the following conditions are met:
2823 * no arguments remaining or the -s flag given
2824 * standard input is a terminal
2825 * standard output is a terminal
2826 * Refer to Posix.2, the description of the `sh' utility. */
2827 if (argv[optind]==NULL && input==stdin &&
2828 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
2832 debug_printf("\ninteractive=%d\n", interactive);
2834 /* Looks like they want an interactive shell */
2835 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
2836 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
2837 printf( "Enter 'help' for a list of built-in commands.\n\n");
2839 setup_job_control();
2842 if (argv[optind]==NULL) {
2843 opt=parse_file_outer(stdin);
2847 debug_printf("\nrunning script '%s'\n", argv[optind]);
2848 global_argv = argv+optind;
2849 global_argc = argc-optind;
2850 input = bb_xfopen(argv[optind], "r");
2851 opt = parse_file_outer(input);
2853 #ifdef CONFIG_FEATURE_CLEAN_UP
2855 if (cwd && cwd != bb_msg_unknown)
2858 struct variables *cur, *tmp;
2859 for(cur = top_vars; cur; cur = tmp) {
2861 if (!cur->flg_read_only) {
2871 return(opt?opt:last_return_code);
2874 static char *insert_var_value(char *inp)
2876 int res_str_len = 0;
2879 char *p, *p1, *res_str = NULL;
2881 while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
2884 res_str = xrealloc(res_str, (res_str_len + len));
2885 strncpy((res_str + res_str_len), inp, len);
2889 p = strchr(inp, SPECIAL_VAR_SYMBOL);
2891 if ((p1 = lookup_param(inp))) {
2892 len = res_str_len + strlen(p1);
2893 res_str = xrealloc(res_str, (1 + len));
2894 strcpy((res_str + res_str_len), p1);
2897 *p = SPECIAL_VAR_SYMBOL;
2902 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
2903 strcpy((res_str + res_str_len), inp);
2904 while ((p = strchr(res_str, '\n'))) {
2908 return (res_str == NULL) ? inp : res_str;
2911 static char **make_list_in(char **inp, char *name)
2914 int name_len = strlen(name);
2919 /* create list of variable values */
2920 list = xmalloc(sizeof(*list));
2921 for (i = 0; inp[i]; i++) {
2922 p3 = insert_var_value(inp[i]);
2929 if ((p2 = strchr(p1, ' '))) {
2935 /* we use n + 2 in realloc for list,because we add
2936 * new element and then we will add NULL element */
2937 list = xrealloc(list, sizeof(*list) * (n + 2));
2938 list[n] = xmalloc(2 + name_len + len);
2939 strcpy(list[n], name);
2940 strcat(list[n], "=");
2941 strncat(list[n], p1, len);
2942 list[n++][name_len + len + 1] = '\0';
2945 if (p3 != inp[i]) free(p3);
2951 /* Make new string for parser */
2952 static char * make_string(char ** inp)
2959 for (n = 0; inp[n]; n++) {
2960 p = insert_var_value(inp[n]);
2961 str = xrealloc(str, (len + strlen(p)));
2968 len = strlen(str) + 3;
2969 if (p != inp[n]) free(p);
2972 *(str + len) = '\n';
2973 *(str + len + 1) = '\0';