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 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
82 #include <ctype.h> /* isalpha, isdigit */
83 #include <unistd.h> /* getpid */
84 #include <stdlib.h> /* getenv, atoi */
85 #include <string.h> /* strchr */
86 #include <stdio.h> /* popen etc. */
87 #include <glob.h> /* glob, of course */
88 #include <stdarg.h> /* va_list */
91 #include <getopt.h> /* should be pretty obvious */
93 #include <sys/stat.h> /* ulimit */
94 #include <sys/types.h>
98 /* #include <dmalloc.h> */
99 /* #define DEBUG_SHELL */
103 #define SPECIAL_VAR_SYMBOL 03
104 #define FLAG_EXIT_FROM_LOOP 1
105 #define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
106 #define FLAG_REPARSING (1 << 2) /* >=2nd pass */
110 REDIRECT_OVERWRITE = 2,
116 /* The descrip member of this structure is only used to make debugging
118 static const struct {int mode; int default_fd; const char *descrip;} redir_table[] = {
120 { O_RDONLY, 0, "<" },
121 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
122 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
123 { O_RDONLY, -1, "<<" },
134 /* might eventually control execution */
151 #define FLAG_END (1<<RES_NONE)
152 #define FLAG_IF (1<<RES_IF)
153 #define FLAG_THEN (1<<RES_THEN)
154 #define FLAG_ELIF (1<<RES_ELIF)
155 #define FLAG_ELSE (1<<RES_ELSE)
156 #define FLAG_FI (1<<RES_FI)
157 #define FLAG_FOR (1<<RES_FOR)
158 #define FLAG_WHILE (1<<RES_WHILE)
159 #define FLAG_UNTIL (1<<RES_UNTIL)
160 #define FLAG_DO (1<<RES_DO)
161 #define FLAG_DONE (1<<RES_DONE)
162 #define FLAG_IN (1<<RES_IN)
163 #define FLAG_START (1<<RES_XXXX)
165 /* This holds pointers to the various results of parsing */
167 struct child_prog *child;
168 struct pipe *list_head;
170 struct redir_struct *pending_redirect;
172 int old_flag; /* for figuring out valid reserved words */
173 struct p_context *stack;
174 int type; /* define type of parser : ";$" common or special symbol */
175 /* How about quoting status? */
178 struct redir_struct {
179 redir_type type; /* type of redirection */
180 int fd; /* file descriptor being redirected */
181 int dup; /* -1, or file descriptor being duplicated */
182 struct redir_struct *next; /* pointer to the next redirect in the list */
183 glob_t word; /* *word.gl_pathv is the filename */
187 pid_t pid; /* 0 if exited */
188 char **argv; /* program name and arguments */
189 struct pipe *group; /* if non-NULL, first in group or subshell */
190 int subshell; /* flag, non-zero if group must be forked */
191 struct redir_struct *redirects; /* I/O redirections */
192 glob_t glob_result; /* result of parameter globbing */
193 int is_stopped; /* is the program currently running? */
194 struct pipe *family; /* pointer back to the child's parent pipe */
195 int sp; /* number of SPECIAL_VAR_SYMBOL */
200 int jobid; /* job number */
201 int num_progs; /* total number of programs in job */
202 int running_progs; /* number of programs running */
203 char *text; /* name of job */
204 char *cmdbuf; /* buffer various argv's point into */
205 pid_t pgrp; /* process group ID for the job */
206 struct child_prog *progs; /* array of commands in pipe */
207 struct pipe *next; /* to track background commands */
208 int stopped_progs; /* number of programs alive, but stopped */
209 int job_context; /* bitmask defining current context */
210 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
211 reserved_style r_mode; /* supports if, for, while, until */
216 struct close_me *next;
224 struct variables *next;
227 /* globals, connect us to the outside world
228 * the first three support $?, $#, and $1 */
229 static char **global_argv;
230 static int global_argc;
231 static int last_return_code;
232 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
234 /* "globals" within this file */
236 static unsigned char map[256];
237 static int fake_mode;
238 static int interactive;
239 static struct close_me *close_me_head;
240 static const char *cwd;
241 static struct pipe *job_list;
242 static unsigned int last_bg_pid;
243 static int last_jobid;
244 static unsigned int shell_terminal;
247 static struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
248 static struct variables *top_vars = &shell_ver;
251 #define B_CHUNK (100)
261 #define NULL_O_STRING {NULL,0,0,0,0}
262 /* used for initialization:
263 o_string foo = NULL_O_STRING; */
265 /* I can almost use ordinary FILE *. Is open_memstream() universally
266 * available? Where is it documented? */
273 int (*get) (struct in_str *);
274 int (*peek) (struct in_str *);
276 #define b_getch(input) ((input)->get(input))
277 #define b_peek(input) ((input)->peek(input))
279 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
281 struct built_in_command {
282 const char *cmd; /* name */
283 const char *descr; /* description */
284 int (*function) (struct child_prog *); /* function ptr */
287 /* belongs in busybox.h */
288 static inline int max(int a, int b) {
292 /* This should be in utility.c */
294 static void debug_printf(const char *format, ...)
297 va_start(args, format);
298 vfprintf(stderr, format, args);
302 static inline void debug_printf(const char *format ATTRIBUTE_UNUSED, ...) { }
304 #define final_printf debug_printf
306 static void __syntax(char *file, int line) {
307 bb_error_msg("syntax error %s:%d", file, line);
309 #define syntax() __syntax(__FILE__, __LINE__)
311 /* Index of subroutines: */
312 /* function prototypes for builtins */
313 static int builtin_cd(struct child_prog *child);
314 static int builtin_env(struct child_prog *child);
315 static int builtin_eval(struct child_prog *child);
316 static int builtin_exec(struct child_prog *child);
317 static int builtin_exit(struct child_prog *child);
318 static int builtin_export(struct child_prog *child);
319 static int builtin_fg_bg(struct child_prog *child);
320 static int builtin_help(struct child_prog *child);
321 static int builtin_jobs(struct child_prog *child);
322 static int builtin_pwd(struct child_prog *child);
323 static int builtin_read(struct child_prog *child);
324 static int builtin_set(struct child_prog *child);
325 static int builtin_shift(struct child_prog *child);
326 static int builtin_source(struct child_prog *child);
327 static int builtin_umask(struct child_prog *child);
328 static int builtin_unset(struct child_prog *child);
329 static int builtin_not_written(struct child_prog *child);
330 /* o_string manipulation: */
331 static int b_check_space(o_string *o, int len);
332 static int b_addchr(o_string *o, int ch);
333 static void b_reset(o_string *o);
334 static int b_addqchr(o_string *o, int ch, int quote);
335 static int b_adduint(o_string *o, unsigned int i);
336 /* in_str manipulations: */
337 static int static_get(struct in_str *i);
338 static int static_peek(struct in_str *i);
339 static int file_get(struct in_str *i);
340 static int file_peek(struct in_str *i);
341 static void setup_file_in_str(struct in_str *i, FILE *f);
342 static void setup_string_in_str(struct in_str *i, const char *s);
343 /* close_me manipulations: */
344 static void mark_open(int fd);
345 static void mark_closed(int fd);
346 static void close_all(void);
347 /* "run" the final data structures: */
348 static char *indenter(int i);
349 static int free_pipe_list(struct pipe *head, int indent);
350 static int free_pipe(struct pipe *pi, int indent);
351 /* really run the final data structures: */
352 static int setup_redirects(struct child_prog *prog, int squirrel[]);
353 static int run_list_real(struct pipe *pi);
354 static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
355 static int run_pipe_real(struct pipe *pi);
356 /* extended glob support: */
357 static int globhack(const char *src, int flags, glob_t *pglob);
358 static int glob_needed(const char *s);
359 static int xglob(o_string *dest, int flags, glob_t *pglob);
360 /* variable assignment: */
361 static int is_assignment(const char *s);
362 /* data structure manipulation: */
363 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
364 static void initialize_context(struct p_context *ctx);
365 static int done_word(o_string *dest, struct p_context *ctx);
366 static int done_command(struct p_context *ctx);
367 static int done_pipe(struct p_context *ctx, pipe_style type);
368 /* primary string parsing: */
369 static int redirect_dup_num(struct in_str *input);
370 static int redirect_opt_num(o_string *o);
371 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
372 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
373 static char *lookup_param(char *src);
374 static char *make_string(char **inp);
375 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
376 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
377 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
379 static int parse_stream_outer(struct in_str *inp, int flag);
380 static int parse_string_outer(const char *s, int flag);
381 static int parse_file_outer(FILE *f);
382 /* job management: */
383 static int checkjobs(struct pipe* fg_pipe);
384 static void insert_bg_job(struct pipe *pi);
385 static void remove_bg_job(struct pipe *pi);
386 /* local variable support */
387 static char **make_list_in(char **inp, char *name);
388 static char *insert_var_value(char *inp);
389 static char *get_local_var(const char *var);
390 static void unset_local_var(const char *name);
391 static int set_local_var(const char *s, int flg_export);
393 /* Table of built-in functions. They can be forked or not, depending on
394 * context: within pipes, they fork. As simple commands, they do not.
395 * When used in non-forking context, they can change global variables
396 * in the parent shell process. If forked, of course they can not.
397 * For example, 'unset foo | whatever' will parse and run, but foo will
398 * still be set at the end. */
399 static const struct built_in_command bltins[] = {
400 {"bg", "Resume a job in the background", builtin_fg_bg},
401 {"break", "Exit for, while or until loop", builtin_not_written},
402 {"cd", "Change working directory", builtin_cd},
403 {"continue", "Continue for, while or until loop", builtin_not_written},
404 {"env", "Print all environment variables", builtin_env},
405 {"eval", "Construct and run shell command", builtin_eval},
406 {"exec", "Exec command, replacing this shell with the exec'd process",
408 {"exit", "Exit from shell()", builtin_exit},
409 {"export", "Set environment variable", builtin_export},
410 {"fg", "Bring job into the foreground", builtin_fg_bg},
411 {"jobs", "Lists the active jobs", builtin_jobs},
412 {"pwd", "Print current directory", builtin_pwd},
413 {"read", "Input environment variable", builtin_read},
414 {"return", "Return from a function", builtin_not_written},
415 {"set", "Set/unset shell local variables", builtin_set},
416 {"shift", "Shift positional parameters", builtin_shift},
417 {"trap", "Trap signals", builtin_not_written},
418 {"ulimit","Controls resource limits", builtin_not_written},
419 {"umask","Sets file creation mask", builtin_umask},
420 {"unset", "Unset environment variable", builtin_unset},
421 {".", "Source-in and run commands in a file", builtin_source},
422 {"help", "List shell built-in commands", builtin_help},
426 static const char *set_cwd(void)
428 if(cwd==bb_msg_unknown)
429 cwd = NULL; /* xgetcwd(arg) called free(arg) */
430 cwd = xgetcwd((char *)cwd);
432 cwd = bb_msg_unknown;
436 /* built-in 'eval' handler */
437 static int builtin_eval(struct child_prog *child)
440 int rcode = EXIT_SUCCESS;
442 if (child->argv[1]) {
443 str = make_string(child->argv + 1);
444 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
445 FLAG_PARSE_SEMICOLON);
447 rcode = last_return_code;
452 /* built-in 'cd <path>' handler */
453 static int builtin_cd(struct child_prog *child)
456 if (child->argv[1] == NULL)
457 newdir = getenv("HOME");
459 newdir = child->argv[1];
461 printf("cd: %s: %s\n", newdir, strerror(errno));
468 /* built-in 'env' handler */
469 static int builtin_env(struct child_prog *dummy ATTRIBUTE_UNUSED)
472 if (e == NULL) return EXIT_FAILURE;
479 /* built-in 'exec' handler */
480 static int builtin_exec(struct child_prog *child)
482 if (child->argv[1] == NULL)
483 return EXIT_SUCCESS; /* Really? */
489 /* built-in 'exit' handler */
490 static int builtin_exit(struct child_prog *child)
492 if (child->argv[1] == NULL)
493 exit(last_return_code);
494 exit (atoi(child->argv[1]));
497 /* built-in 'export VAR=value' handler */
498 static int builtin_export(struct child_prog *child)
501 char *name = child->argv[1];
504 return (builtin_env(child));
510 char *value = strchr(name, '=');
514 /* They are exporting something without an =VALUE */
516 value = get_local_var(name);
518 size_t ln = strlen(name);
520 tmp = realloc(name, ln+strlen(value)+2);
524 sprintf(tmp+ln, "=%s", value);
528 /* bash does not return an error when trying to export
529 * an undefined variable. Do likewise. */
535 bb_perror_msg("export");
537 res = set_local_var(name, 1);
544 /* built-in 'fg' and 'bg' handler */
545 static int builtin_fg_bg(struct child_prog *child)
548 struct pipe *pi=NULL;
552 /* If they gave us no args, assume they want the last backgrounded task */
553 if (!child->argv[1]) {
554 for (pi = job_list; pi; pi = pi->next) {
555 if (pi->jobid == last_jobid) {
560 bb_error_msg("%s: no current job", child->argv[0]);
564 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
565 bb_error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
568 for (pi = job_list; pi; pi = pi->next) {
569 if (pi->jobid == jobnum) {
574 bb_error_msg("%s: %d: no such job", child->argv[0], jobnum);
579 if (*child->argv[0] == 'f') {
580 /* Put the job into the foreground. */
581 tcsetpgrp(shell_terminal, pi->pgrp);
584 /* Restart the processes in the job */
585 for (i = 0; i < pi->num_progs; i++)
586 pi->progs[i].is_stopped = 0;
588 if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
592 bb_perror_msg("kill (SIGCONT)");
596 pi->stopped_progs = 0;
600 /* built-in 'help' handler */
601 static int builtin_help(struct child_prog *dummy ATTRIBUTE_UNUSED)
603 const struct built_in_command *x;
605 printf("\nBuilt-in commands:\n");
606 printf("-------------------\n");
607 for (x = bltins; x->cmd; x++) {
610 printf("%s\t%s\n", x->cmd, x->descr);
616 /* built-in 'jobs' handler */
617 static int builtin_jobs(struct child_prog *child ATTRIBUTE_UNUSED)
622 for (job = job_list; job; job = job->next) {
623 if (job->running_progs == job->stopped_progs)
624 status_string = "Stopped";
626 status_string = "Running";
628 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
634 /* built-in 'pwd' handler */
635 static int builtin_pwd(struct child_prog *dummy ATTRIBUTE_UNUSED)
641 /* built-in 'read VAR' handler */
642 static int builtin_read(struct child_prog *child)
646 if (child->argv[1]) {
650 string[0] = 0; /* In case stdin has only EOF */
652 fgets(string, sizeof(string), stdin);
654 var = malloc(strlen(child->argv[1])+strlen(string)+2);
656 sprintf(var, "%s=%s", child->argv[1], string);
657 res = set_local_var(var, 0);
661 bb_perror_msg("read");
662 free(var); /* So not move up to avoid breaking errno */
665 do res=getchar(); while(res!='\n' && res!=EOF);
670 /* built-in 'set VAR=value' handler */
671 static int builtin_set(struct child_prog *child)
673 char *temp = child->argv[1];
677 for(e = top_vars; e; e=e->next)
678 printf("%s=%s\n", e->name, e->value);
680 set_local_var(temp, 0);
686 /* Built-in 'shift' handler */
687 static int builtin_shift(struct child_prog *child)
690 if (child->argv[1]) {
691 n=atoi(child->argv[1]);
693 if (n>=0 && n<global_argc) {
694 /* XXX This probably breaks $0 */
703 /* Built-in '.' handler (read-in and execute commands from file) */
704 static int builtin_source(struct child_prog *child)
709 if (child->argv[1] == NULL)
712 /* XXX search through $PATH is missing */
713 input = fopen(child->argv[1], "r");
715 bb_error_msg("Couldn't open file '%s'", child->argv[1]);
719 /* Now run the file */
720 /* XXX argv and argc are broken; need to save old global_argv
721 * (pointer only is OK!) on this stack frame,
722 * set global_argv=child->argv+1, recurse, and restore. */
723 mark_open(fileno(input));
724 status = parse_file_outer(input);
725 mark_closed(fileno(input));
730 static int builtin_umask(struct child_prog *child)
733 const char *arg = child->argv[1];
736 new_umask=strtoul(arg, &end, 8);
737 if (*end!='\0' || end == arg) {
741 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
747 /* built-in 'unset VAR' handler */
748 static int builtin_unset(struct child_prog *child)
750 /* bash returned already true */
751 unset_local_var(child->argv[1]);
755 static int builtin_not_written(struct child_prog *child)
757 printf("builtin_%s not written\n",child->argv[0]);
761 static int b_check_space(o_string *o, int len)
763 /* It would be easy to drop a more restrictive policy
764 * in here, such as setting a maximum string length */
765 if (o->length + len > o->maxlen) {
766 char *old_data = o->data;
767 /* assert (data == NULL || o->maxlen != 0); */
768 o->maxlen += max(2*len, B_CHUNK);
769 o->data = realloc(o->data, 1 + o->maxlen);
770 if (o->data == NULL) {
774 return o->data == NULL;
777 static int b_addchr(o_string *o, int ch)
779 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
780 if (b_check_space(o, 1)) return B_NOSPAC;
781 o->data[o->length] = ch;
783 o->data[o->length] = '\0';
787 static void b_reset(o_string *o)
791 if (o->data != NULL) *o->data = '\0';
794 static void b_free(o_string *o)
802 /* My analysis of quoting semantics tells me that state information
803 * is associated with a destination, not a source.
805 static int b_addqchr(o_string *o, int ch, int quote)
807 if (quote && strchr("*?[\\",ch)) {
809 rc = b_addchr(o, '\\');
812 return b_addchr(o, ch);
815 /* belongs in utility.c */
816 static char *simple_itoa(unsigned int i)
818 /* 21 digits plus null terminator, good for 64-bit or smaller ints */
819 static char local[22];
820 char *p = &local[21];
829 static int b_adduint(o_string *o, unsigned int i)
832 char *p = simple_itoa(i);
833 /* no escape checking necessary */
834 do r=b_addchr(o, *p++); while (r==0 && *p);
838 static int static_get(struct in_str *i)
841 if (ch=='\0') return EOF;
845 static int static_peek(struct in_str *i)
850 static inline void cmdedit_set_initial_prompt(void)
852 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
861 static inline void setup_prompt_string(int promptmode, char **prompt_str)
863 debug_printf("setup_prompt_string %d ",promptmode);
864 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
865 /* Set up the prompt */
866 if (promptmode == 1) {
868 PS1=xmalloc(strlen(cwd)+4);
869 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
875 *prompt_str = (promptmode==1)? PS1 : PS2;
877 debug_printf("result %s\n",*prompt_str);
880 static void get_user_input(struct in_str *i)
883 static char the_command[BUFSIZ];
885 setup_prompt_string(i->promptmode, &prompt_str);
886 #ifdef CONFIG_FEATURE_COMMAND_EDITING
888 ** enable command line editing only while a command line
889 ** is actually being read; otherwise, we'll end up bequeathing
890 ** atexit() handlers and other unwanted stuff to our
891 ** child processes (rob@sysgo.de)
893 cmdedit_read_input(prompt_str, the_command);
895 fputs(prompt_str, stdout);
897 the_command[0]=fgetc(i->file);
904 /* This is the magic location that prints prompts
905 * and gets data back from the user */
906 static int file_get(struct in_str *i)
911 /* If there is data waiting, eat it up */
915 /* need to double check i->file because we might be doing something
916 * more complicated by now, like sourcing or substituting. */
917 if (i->__promptme && interactive && i->file == stdin) {
918 while(! i->p || (interactive && strlen(i->p)==0) ) {
930 debug_printf("b_getch: got a %d\n", ch);
932 if (ch == '\n') i->__promptme=1;
936 /* All the callers guarantee this routine will never be
937 * used right after a newline, so prompting is not needed.
939 static int file_peek(struct in_str *i)
944 i->peek_buf[0] = fgetc(i->file);
945 i->peek_buf[1] = '\0';
947 debug_printf("b_peek: got a %d\n", *i->p);
952 static void setup_file_in_str(struct in_str *i, FILE *f)
962 static void setup_string_in_str(struct in_str *i, const char *s)
964 i->peek = static_peek;
971 static void mark_open(int fd)
973 struct close_me *new = xmalloc(sizeof(struct close_me));
975 new->next = close_me_head;
979 static void mark_closed(int fd)
981 struct close_me *tmp;
982 if (close_me_head == NULL || close_me_head->fd != fd)
983 bb_error_msg_and_die("corrupt close_me");
985 close_me_head = close_me_head->next;
989 static void close_all(void)
992 for (c=close_me_head; c; c=c->next) {
995 close_me_head = NULL;
998 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
999 * and stderr if they are redirected. */
1000 static int setup_redirects(struct child_prog *prog, int squirrel[])
1003 struct redir_struct *redir;
1005 for (redir=prog->redirects; redir; redir=redir->next) {
1006 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1007 /* something went wrong in the parse. Pretend it didn't happen */
1010 if (redir->dup == -1) {
1011 mode=redir_table[redir->type].mode;
1012 openfd = open(redir->word.gl_pathv[0], mode, 0666);
1014 /* this could get lost if stderr has been redirected, but
1015 bash and ash both lose it as well (though zsh doesn't!) */
1016 bb_perror_msg("error opening %s", redir->word.gl_pathv[0]);
1020 openfd = redir->dup;
1023 if (openfd != redir->fd) {
1024 if (squirrel && redir->fd < 3) {
1025 squirrel[redir->fd] = dup(redir->fd);
1030 dup2(openfd, redir->fd);
1031 if (redir->dup == -1)
1039 static void restore_redirects(int squirrel[])
1042 for (i=0; i<3; i++) {
1045 /* No error checking. I sure wouldn't know what
1046 * to do with an error if I found one! */
1054 /* XXX no exit() here. If you don't exec, use _exit instead.
1055 * The at_exit handlers apparently confuse the calling process,
1056 * in particular stdin handling. Not sure why? */
1057 static void pseudo_exec(struct child_prog *child)
1061 const struct built_in_command *x;
1063 for (i=0; is_assignment(child->argv[i]); i++) {
1064 debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1065 p = insert_var_value(child->argv[i]);
1067 if (p != child->argv[i]) free(p);
1069 child->argv+=i; /* XXX this hack isn't so horrible, since we are about
1070 to exit, and therefore don't need to keep data
1071 structures consistent for free() use. */
1072 /* If a variable is assigned in a forest, and nobody listens,
1073 * was it ever really set?
1075 if (child->argv[0] == NULL) {
1076 _exit(EXIT_SUCCESS);
1080 * Check if the command matches any of the builtins.
1081 * Depending on context, this might be redundant. But it's
1082 * easier to waste a few CPU cycles than it is to figure out
1083 * if this is one of those cases.
1085 for (x = bltins; x->cmd; x++) {
1086 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1087 debug_printf("builtin exec %s\n", child->argv[0]);
1088 rcode = x->function(child);
1094 /* Check if the command matches any busybox internal commands
1096 * FIXME: This feature is not 100% safe, since
1097 * BusyBox is not fully reentrant, so we have no guarantee the things
1098 * from the .bss are still zeroed, or that things from .data are still
1099 * at their defaults. We could exec ourself from /proc/self/exe, but I
1100 * really dislike relying on /proc for things. We could exec ourself
1101 * from global_argv[0], but if we are in a chroot, we may not be able
1102 * to find ourself... */
1103 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1106 char** argv_l=child->argv;
1107 char *name = child->argv[0];
1109 /* Count argc for use in a second... */
1110 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1112 debug_printf("running applet %s\n", name);
1113 run_applet_by_name(name, argc_l, child->argv);
1116 debug_printf("exec of %s\n",child->argv[0]);
1117 execvp(child->argv[0],child->argv);
1118 bb_perror_msg("couldn't exec: %s",child->argv[0]);
1120 } else if (child->group) {
1121 debug_printf("runtime nesting to group\n");
1122 interactive=0; /* crucial!!!! */
1123 rcode = run_list_real(child->group);
1124 /* OK to leak memory by not calling free_pipe_list,
1125 * since this process is about to exit */
1128 /* Can happen. See what bash does with ">foo" by itself. */
1129 debug_printf("trying to pseudo_exec null command\n");
1130 _exit(EXIT_SUCCESS);
1134 static void insert_bg_job(struct pipe *pi)
1136 struct pipe *thejob;
1138 /* Linear search for the ID of the job to use */
1140 for (thejob = job_list; thejob; thejob = thejob->next)
1141 if (thejob->jobid >= pi->jobid)
1142 pi->jobid = thejob->jobid + 1;
1144 /* add thejob to the list of running jobs */
1146 thejob = job_list = xmalloc(sizeof(*thejob));
1148 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1149 thejob->next = xmalloc(sizeof(*thejob));
1150 thejob = thejob->next;
1153 /* physically copy the struct job */
1154 memcpy(thejob, pi, sizeof(struct pipe));
1155 thejob->next = NULL;
1156 thejob->running_progs = thejob->num_progs;
1157 thejob->stopped_progs = 0;
1158 thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1160 //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
1162 char *bar=thejob->text;
1163 char **foo=pi->progs[0].argv;
1164 while(foo && *foo) {
1165 bar += sprintf(bar, "%s ", *foo++);
1169 /* we don't wait for background thejobs to return -- append it
1170 to the list of backgrounded thejobs and leave it alone */
1171 printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1172 last_bg_pid = thejob->progs[0].pid;
1173 last_jobid = thejob->jobid;
1176 /* remove a backgrounded job */
1177 static void remove_bg_job(struct pipe *pi)
1179 struct pipe *prev_pipe;
1181 if (pi == job_list) {
1182 job_list = pi->next;
1184 prev_pipe = job_list;
1185 while (prev_pipe->next != pi)
1186 prev_pipe = prev_pipe->next;
1187 prev_pipe->next = pi->next;
1190 last_jobid = job_list->jobid;
1194 pi->stopped_progs = 0;
1199 /* Checks to see if any processes have exited -- if they
1200 have, figure out why and see if a job has completed */
1201 static int checkjobs(struct pipe* fg_pipe)
1209 attributes = WUNTRACED;
1210 if (fg_pipe==NULL) {
1211 attributes |= WNOHANG;
1214 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1217 for (i=0; i < fg_pipe->num_progs; i++) {
1218 if (fg_pipe->progs[i].pid == childpid) {
1219 if (i==fg_pipe->num_progs-1)
1220 rcode=WEXITSTATUS(status);
1221 (fg_pipe->num_progs)--;
1227 for (pi = job_list; pi; pi = pi->next) {
1229 while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1232 if (prognum < pi->num_progs)
1237 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1241 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1243 pi->running_progs--;
1244 pi->progs[prognum].pid = 0;
1246 if (!pi->running_progs) {
1247 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1252 pi->stopped_progs++;
1253 pi->progs[prognum].is_stopped = 1;
1257 if (childpid == -1 && errno != ECHILD)
1258 bb_perror_msg("waitpid");
1260 /* move the shell to the foreground */
1261 //if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
1262 // bb_perror_msg("tcsetpgrp-2");
1266 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1267 * to finish. See checkjobs().
1269 * return code is normally -1, when the caller has to wait for children
1270 * to finish to determine the exit status of the pipe. If the pipe
1271 * is a simple builtin command, however, the action is done by the
1272 * time run_pipe_real returns, and the exit code is provided as the
1275 * The input of the pipe is always stdin, the output is always
1276 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1277 * because it tries to avoid running the command substitution in
1278 * subshell, when that is in fact necessary. The subshell process
1279 * now has its stdout directed to the input of the appropriate pipe,
1280 * so this routine is noticeably simpler.
1282 static int run_pipe_real(struct pipe *pi)
1285 int nextin, nextout;
1286 int pipefds[2]; /* pipefds[0] is for reading */
1287 struct child_prog *child;
1288 const struct built_in_command *x;
1294 /* Check if this is a simple builtin (not part of a pipe).
1295 * Builtins within pipes have to fork anyway, and are handled in
1296 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1298 if (pi->num_progs == 1) child = & (pi->progs[0]);
1299 if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1300 int squirrel[] = {-1, -1, -1};
1302 debug_printf("non-subshell grouping\n");
1303 setup_redirects(child, squirrel);
1304 /* XXX could we merge code with following builtin case,
1305 * by creating a pseudo builtin that calls run_list_real? */
1306 rcode = run_list_real(child->group);
1307 restore_redirects(squirrel);
1309 } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1310 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1311 if (i!=0 && child->argv[i]==NULL) {
1312 /* assignments, but no command: set the local environment */
1313 for (i=0; child->argv[i]!=NULL; i++) {
1315 /* Ok, this case is tricky. We have to decide if this is a
1316 * local variable, or an already exported variable. If it is
1317 * already exported, we have to export the new value. If it is
1318 * not exported, we need only set this as a local variable.
1319 * This junk is all to decide whether or not to export this
1323 name = bb_xstrdup(child->argv[i]);
1324 debug_printf("Local environment set: %s\n", name);
1325 value = strchr(name, '=');
1328 if ( get_local_var(name)) {
1332 p = insert_var_value(child->argv[i]);
1333 set_local_var(p, export_me);
1334 if (p != child->argv[i]) free(p);
1336 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1338 for (i = 0; is_assignment(child->argv[i]); i++) {
1339 p = insert_var_value(child->argv[i]);
1341 if (p != child->argv[i]) {
1349 str = make_string((child->argv + i));
1350 parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1352 return last_return_code;
1354 for (x = bltins; x->cmd; x++) {
1355 if (strcmp(child->argv[i], x->cmd) == 0 ) {
1356 int squirrel[] = {-1, -1, -1};
1358 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1359 debug_printf("magic exec\n");
1360 setup_redirects(child,NULL);
1361 return EXIT_SUCCESS;
1363 debug_printf("builtin inline %s\n", child->argv[0]);
1364 /* XXX setup_redirects acts on file descriptors, not FILEs.
1365 * This is perfect for work that comes after exec().
1366 * Is it really safe for inline use? Experimentally,
1367 * things seem to work with glibc. */
1368 setup_redirects(child, squirrel);
1369 child->argv+=i; /* XXX horrible hack */
1370 rcode = x->function(child);
1371 child->argv-=i; /* XXX restore hack so free() can work right */
1372 restore_redirects(squirrel);
1378 for (i = 0; i < pi->num_progs; i++) {
1379 child = & (pi->progs[i]);
1381 /* pipes are inserted between pairs of commands */
1382 if ((i + 1) < pi->num_progs) {
1383 if (pipe(pipefds)<0) bb_perror_msg_and_die("pipe");
1384 nextout = pipefds[1];
1390 /* XXX test for failed fork()? */
1391 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
1392 if (!(child->pid = fork()))
1394 if (!(child->pid = vfork()))
1397 /* Set the handling for job control signals back to the default. */
1398 signal(SIGINT, SIG_DFL);
1399 signal(SIGQUIT, SIG_DFL);
1400 signal(SIGTERM, SIG_DFL);
1401 signal(SIGTSTP, SIG_DFL);
1402 signal(SIGTTIN, SIG_DFL);
1403 signal(SIGTTOU, SIG_DFL);
1404 signal(SIGCHLD, SIG_DFL);
1416 if (pipefds[0]!=-1) {
1417 close(pipefds[0]); /* opposite end of our output pipe */
1420 /* Like bash, explicit redirects override pipes,
1421 * and the pipe fd is available for dup'ing. */
1422 setup_redirects(child,NULL);
1424 if (interactive && pi->followup!=PIPE_BG) {
1425 /* If we (the child) win the race, put ourselves in the process
1426 * group whose leader is the first process in this pipe. */
1428 pi->pgrp = getpid();
1430 if (setpgid(0, pi->pgrp) == 0) {
1431 tcsetpgrp(2, pi->pgrp);
1439 /* put our child in the process group whose leader is the
1440 first process in this pipe */
1442 pi->pgrp = child->pid;
1444 /* Don't check for errors. The child may be dead already,
1445 * in which case setpgid returns error code EACCES. */
1446 setpgid(child->pid, pi->pgrp);
1453 /* If there isn't another process, nextin is garbage
1454 but it doesn't matter */
1455 nextin = pipefds[0];
1460 static int run_list_real(struct pipe *pi)
1462 char *save_name = NULL;
1464 char **save_list = NULL;
1468 int rcode=0, flag_skip=1;
1469 int flag_restore = 0;
1470 int if_code=0, next_if_code=0; /* need double-buffer to handle elif */
1471 reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1472 /* check syntax for "for" */
1473 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1474 if ((rpipe->r_mode == RES_IN ||
1475 rpipe->r_mode == RES_FOR) &&
1476 (rpipe->next == NULL)) {
1480 if ((rpipe->r_mode == RES_IN &&
1481 (rpipe->next->r_mode == RES_IN &&
1482 rpipe->next->progs->argv != NULL))||
1483 (rpipe->r_mode == RES_FOR &&
1484 rpipe->next->r_mode != RES_IN)) {
1489 for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1490 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1491 pi->r_mode == RES_FOR) {
1499 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);
1500 if (rmode == skip_more_in_this_rmode && flag_skip) {
1501 if (pi->followup == PIPE_SEQ) flag_skip=0;
1505 skip_more_in_this_rmode = RES_XXXX;
1506 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1507 if (rmode == RES_THEN && if_code) continue;
1508 if (rmode == RES_ELSE && !if_code) continue;
1509 if (rmode == RES_ELIF && !if_code) break;
1510 if (rmode == RES_FOR && pi->num_progs) {
1512 /* if no variable values after "in" we skip "for" */
1513 if (!pi->next->progs->argv) continue;
1514 /* create list of variable values */
1515 list = make_list_in(pi->next->progs->argv,
1516 pi->progs->argv[0]);
1518 save_name = pi->progs->argv[0];
1519 pi->progs->argv[0] = NULL;
1523 free(pi->progs->argv[0]);
1527 pi->progs->argv[0] = save_name;
1528 pi->progs->glob_result.gl_pathv[0] =
1532 /* insert new value from list for variable */
1533 if (pi->progs->argv[0])
1534 free(pi->progs->argv[0]);
1535 pi->progs->argv[0] = *list++;
1536 pi->progs->glob_result.gl_pathv[0] =
1540 if (rmode == RES_IN) continue;
1541 if (rmode == RES_DO) {
1542 if (!flag_rep) continue;
1544 if ((rmode == RES_DONE)) {
1551 if (pi->num_progs == 0) continue;
1552 save_num_progs = pi->num_progs; /* save number of programs */
1553 rcode = run_pipe_real(pi);
1554 debug_printf("run_pipe_real returned %d\n",rcode);
1556 /* We only ran a builtin: rcode was set by the return value
1557 * of run_pipe_real(), and we don't need to wait for anything. */
1558 } else if (pi->followup==PIPE_BG) {
1559 /* XXX check bash's behavior with nontrivial pipes */
1560 /* XXX compute jobid */
1561 /* XXX what does bash do with attempts to background builtins? */
1563 rcode = EXIT_SUCCESS;
1566 /* move the new process group into the foreground */
1567 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1568 bb_perror_msg("tcsetpgrp-3");
1569 rcode = checkjobs(pi);
1570 /* move the shell to the foreground */
1571 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1572 bb_perror_msg("tcsetpgrp-4");
1574 rcode = checkjobs(pi);
1576 debug_printf("checkjobs returned %d\n",rcode);
1578 last_return_code=rcode;
1579 pi->num_progs = save_num_progs; /* restore number of programs */
1580 if ( rmode == RES_IF || rmode == RES_ELIF )
1581 next_if_code=rcode; /* can be overwritten a number of times */
1582 if (rmode == RES_WHILE)
1583 flag_rep = !last_return_code;
1584 if (rmode == RES_UNTIL)
1585 flag_rep = last_return_code;
1586 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1587 (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1588 skip_more_in_this_rmode=rmode;
1594 /* broken, of course, but OK for testing */
1595 static char *indenter(int i)
1597 static char blanks[]=" ";
1598 return &blanks[sizeof(blanks)-i-1];
1601 /* return code is the exit status of the pipe */
1602 static int free_pipe(struct pipe *pi, int indent)
1605 struct child_prog *child;
1606 struct redir_struct *r, *rnext;
1607 int a, i, ret_code=0;
1608 char *ind = indenter(indent);
1610 if (pi->stopped_progs > 0)
1612 final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1613 for (i=0; i<pi->num_progs; i++) {
1614 child = &pi->progs[i];
1615 final_printf("%s command %d:\n",ind,i);
1617 for (a=0,p=child->argv; *p; a++,p++) {
1618 final_printf("%s argv[%d] = %s\n",ind,a,*p);
1620 globfree(&child->glob_result);
1622 } else if (child->group) {
1623 final_printf("%s begin group (subshell:%d)\n",ind, child->subshell);
1624 ret_code = free_pipe_list(child->group,indent+3);
1625 final_printf("%s end group\n",ind);
1627 final_printf("%s (nil)\n",ind);
1629 for (r=child->redirects; r; r=rnext) {
1630 final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1632 /* guard against the case >$FOO, where foo is unset or blank */
1633 if (r->word.gl_pathv) {
1634 final_printf(" %s\n", *r->word.gl_pathv);
1638 final_printf("&%d\n", r->dup);
1643 child->redirects=NULL;
1645 free(pi->progs); /* children are an array, they get freed all at once */
1650 static int free_pipe_list(struct pipe *head, int indent)
1652 int rcode=0; /* if list has no members */
1653 struct pipe *pi, *next;
1654 char *ind = indenter(indent);
1655 for (pi=head; pi; pi=next) {
1656 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1657 rcode = free_pipe(pi, indent);
1658 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1666 /* Select which version we will use */
1667 static int run_list(struct pipe *pi)
1671 rcode = run_list_real(pi);
1673 /* free_pipe_list has the side effect of clearing memory
1674 * In the long run that function can be merged with run_list_real,
1675 * but doing that now would hobble the debugging effort. */
1676 free_pipe_list(pi,0);
1680 /* The API for glob is arguably broken. This routine pushes a non-matching
1681 * string into the output structure, removing non-backslashed backslashes.
1682 * If someone can prove me wrong, by performing this function within the
1683 * original glob(3) api, feel free to rewrite this routine into oblivion.
1684 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1685 * XXX broken if the last character is '\\', check that before calling.
1687 static int globhack(const char *src, int flags, glob_t *pglob)
1692 for (cnt=1, s=src; s && *s; s++) {
1693 if (*s == '\\') s++;
1697 if (!dest) return GLOB_NOSPACE;
1698 if (!(flags & GLOB_APPEND)) {
1699 pglob->gl_pathv=NULL;
1704 pathc = ++pglob->gl_pathc;
1705 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1706 if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
1707 pglob->gl_pathv[pathc-1]=dest;
1708 pglob->gl_pathv[pathc]=NULL;
1709 for (s=src; s && *s; s++, dest++) {
1710 if (*s == '\\') s++;
1717 /* XXX broken if the last character is '\\', check that before calling */
1718 static int glob_needed(const char *s)
1721 if (*s == '\\') s++;
1722 if (strchr("*[?",*s)) return 1;
1727 static int xglob(o_string *dest, int flags, glob_t *pglob)
1731 /* short-circuit for null word */
1732 /* we can code this better when the debug_printf's are gone */
1733 if (dest->length == 0) {
1734 if (dest->nonnull) {
1735 /* bash man page calls this an "explicit" null */
1736 gr = globhack(dest->data, flags, pglob);
1737 debug_printf("globhack returned %d\n",gr);
1741 } else if (glob_needed(dest->data)) {
1742 gr = glob(dest->data, flags, NULL, pglob);
1743 debug_printf("glob returned %d\n",gr);
1744 if (gr == GLOB_NOMATCH) {
1745 /* quote removal, or more accurately, backslash removal */
1746 gr = globhack(dest->data, flags, pglob);
1747 debug_printf("globhack returned %d\n",gr);
1750 gr = globhack(dest->data, flags, pglob);
1751 debug_printf("globhack returned %d\n",gr);
1753 if (gr == GLOB_NOSPACE)
1754 bb_error_msg_and_die("out of memory during glob");
1755 if (gr != 0) { /* GLOB_ABORTED ? */
1756 bb_error_msg("glob(3) error %d",gr);
1758 /* globprint(glob_target); */
1762 /* This is used to get/check local shell variables */
1763 static char *get_local_var(const char *s)
1765 struct variables *cur;
1769 for (cur = top_vars; cur; cur=cur->next)
1770 if(strcmp(cur->name, s)==0)
1775 /* This is used to set local shell variables
1776 flg_export==0 if only local (not exporting) variable
1777 flg_export==1 if "new" exporting environ
1778 flg_export>1 if current startup environ (not call putenv()) */
1779 static int set_local_var(const char *s, int flg_export)
1783 struct variables *cur;
1787 /* Assume when we enter this function that we are already in
1788 * NAME=VALUE format. So the first order of business is to
1789 * split 's' on the '=' into 'name' and 'value' */
1790 value = strchr(name, '=');
1791 if (value==0 && ++value==0) {
1797 for(cur = top_vars; cur; cur = cur->next) {
1798 if(strcmp(cur->name, name)==0)
1803 if(strcmp(cur->value, value)==0) {
1804 if(flg_export>0 && cur->flg_export==0)
1805 cur->flg_export=flg_export;
1809 if(cur->flg_read_only) {
1810 bb_error_msg("%s: readonly variable", name);
1813 if(flg_export>0 || cur->flg_export>1)
1817 cur->value = strdup(value);
1821 cur = malloc(sizeof(struct variables));
1825 cur->name = strdup(name);
1826 if(cur->name == 0) {
1830 struct variables *bottom = top_vars;
1831 cur->value = strdup(value);
1833 cur->flg_export = flg_export;
1834 cur->flg_read_only = 0;
1835 while(bottom->next) bottom=bottom->next;
1841 if(result==0 && cur->flg_export==1) {
1843 result = putenv(name);
1846 if(result>0) /* equivalent to previous set */
1852 static void unset_local_var(const char *name)
1854 struct variables *cur;
1857 for (cur = top_vars; cur; cur=cur->next) {
1858 if(strcmp(cur->name, name)==0)
1862 struct variables *next = top_vars;
1863 if(cur->flg_read_only) {
1864 bb_error_msg("%s: readonly variable", name);
1868 unsetenv(cur->name);
1871 while (next->next != cur)
1873 next->next = cur->next;
1880 static int is_assignment(const char *s)
1882 if (s==NULL || !isalpha(*s)) return 0;
1884 while(isalnum(*s) || *s=='_') ++s;
1888 /* the src parameter allows us to peek forward to a possible &n syntax
1889 * for file descriptor duplication, e.g., "2>&1".
1890 * Return code is 0 normally, 1 if a syntax error is detected in src.
1891 * Resource errors (in xmalloc) cause the process to exit */
1892 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1893 struct in_str *input)
1895 struct child_prog *child=ctx->child;
1896 struct redir_struct *redir = child->redirects;
1897 struct redir_struct *last_redir=NULL;
1899 /* Create a new redir_struct and drop it onto the end of the linked list */
1904 redir = xmalloc(sizeof(struct redir_struct));
1906 redir->word.gl_pathv=NULL;
1908 last_redir->next=redir;
1910 child->redirects=redir;
1914 redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
1916 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1918 /* Check for a '2>&1' type redirect */
1919 redir->dup = redirect_dup_num(input);
1920 if (redir->dup == -2) return 1; /* syntax error */
1921 if (redir->dup != -1) {
1922 /* Erik had a check here that the file descriptor in question
1923 * is legit; I postpone that to "run time"
1924 * A "-" representation of "close me" shows up as a -3 here */
1925 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
1927 /* We do _not_ try to open the file that src points to,
1928 * since we need to return and let src be expanded first.
1929 * Set ctx->pending_redirect, so we know what to do at the
1930 * end of the next parsed word.
1932 ctx->pending_redirect = redir;
1937 static struct pipe *new_pipe(void) {
1939 pi = xmalloc(sizeof(struct pipe));
1943 pi->followup = 0; /* invalid */
1944 pi->r_mode = RES_NONE;
1948 static void initialize_context(struct p_context *ctx)
1951 ctx->pending_redirect=NULL;
1953 ctx->list_head=new_pipe();
1954 ctx->pipe=ctx->list_head;
1958 done_command(ctx); /* creates the memory for working child */
1961 /* normal return is 0
1962 * if a reserved word is found, and processed, return 1
1963 * should handle if, then, elif, else, fi, for, while, until, do, done.
1964 * case, function, and select are obnoxious, save those for later.
1966 static int reserved_word(o_string *dest, struct p_context *ctx)
1968 struct reserved_combo {
1973 /* Mostly a list of accepted follow-up reserved words.
1974 * FLAG_END means we are done with the sequence, and are ready
1975 * to turn the compound list into a command.
1976 * FLAG_START means the word must start a new compound list.
1978 static struct reserved_combo reserved_list[] = {
1979 { "if", RES_IF, FLAG_THEN | FLAG_START },
1980 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
1981 { "elif", RES_ELIF, FLAG_THEN },
1982 { "else", RES_ELSE, FLAG_FI },
1983 { "fi", RES_FI, FLAG_END },
1984 { "for", RES_FOR, FLAG_IN | FLAG_START },
1985 { "while", RES_WHILE, FLAG_DO | FLAG_START },
1986 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
1987 { "in", RES_IN, FLAG_DO },
1988 { "do", RES_DO, FLAG_DONE },
1989 { "done", RES_DONE, FLAG_END }
1991 struct reserved_combo *r;
1992 for (r=reserved_list;
1993 #define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
1994 r<reserved_list+NRES; r++) {
1995 if (strcmp(dest->data, r->literal) == 0) {
1996 debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
1997 if (r->flag & FLAG_START) {
1998 struct p_context *new = xmalloc(sizeof(struct p_context));
1999 debug_printf("push stack\n");
2000 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2007 *new = *ctx; /* physical copy */
2008 initialize_context(ctx);
2010 } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2017 ctx->old_flag = r->flag;
2018 if (ctx->old_flag & FLAG_END) {
2019 struct p_context *old;
2020 debug_printf("pop stack\n");
2021 done_pipe(ctx,PIPE_SEQ);
2023 old->child->group = ctx->list_head;
2024 old->child->subshell = 0;
2025 *ctx = *old; /* physical copy */
2035 /* normal return is 0.
2036 * Syntax or xglob errors return 1. */
2037 static int done_word(o_string *dest, struct p_context *ctx)
2039 struct child_prog *child=ctx->child;
2040 glob_t *glob_target;
2043 debug_printf("done_word: %s %p\n", dest->data, child);
2044 if (dest->length == 0 && !dest->nonnull) {
2045 debug_printf(" true null, ignored\n");
2048 if (ctx->pending_redirect) {
2049 glob_target = &ctx->pending_redirect->word;
2053 return 1; /* syntax error, groups and arglists don't mix */
2055 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2056 debug_printf("checking %s for reserved-ness\n",dest->data);
2057 if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2059 glob_target = &child->glob_result;
2060 if (child->argv) flags |= GLOB_APPEND;
2062 gr = xglob(dest, flags, glob_target);
2063 if (gr != 0) return 1;
2066 if (ctx->pending_redirect) {
2067 ctx->pending_redirect=NULL;
2068 if (glob_target->gl_pathc != 1) {
2069 bb_error_msg("ambiguous redirect");
2073 child->argv = glob_target->gl_pathv;
2075 if (ctx->w == RES_FOR) {
2076 done_word(dest,ctx);
2077 done_pipe(ctx,PIPE_SEQ);
2082 /* The only possible error here is out of memory, in which case
2084 static int done_command(struct p_context *ctx)
2086 /* The child is really already in the pipe structure, so
2087 * advance the pipe counter and make a new, null child.
2088 * Only real trickiness here is that the uncommitted
2089 * child structure, to which ctx->child points, is not
2090 * counted in pi->num_progs. */
2091 struct pipe *pi=ctx->pipe;
2092 struct child_prog *prog=ctx->child;
2094 if (prog && prog->group == NULL
2095 && prog->argv == NULL
2096 && prog->redirects == NULL) {
2097 debug_printf("done_command: skipping null command\n");
2101 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2103 debug_printf("done_command: initializing\n");
2105 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2107 prog = pi->progs + pi->num_progs;
2108 prog->redirects = NULL;
2110 prog->is_stopped = 0;
2112 prog->glob_result.gl_pathv = NULL;
2116 prog->type = ctx->type;
2118 /* but ctx->pipe and ctx->list_head remain unchanged */
2122 static int done_pipe(struct p_context *ctx, pipe_style type)
2125 done_command(ctx); /* implicit closure of previous command */
2126 debug_printf("done_pipe, type %d\n", type);
2127 ctx->pipe->followup = type;
2128 ctx->pipe->r_mode = ctx->w;
2130 ctx->pipe->next = new_p;
2133 done_command(ctx); /* set up new pipe to accept commands */
2137 /* peek ahead in the in_str to find out if we have a "&n" construct,
2138 * as in "2>&1", that represents duplicating a file descriptor.
2139 * returns either -2 (syntax error), -1 (no &), or the number found.
2141 static int redirect_dup_num(struct in_str *input)
2145 if (ch != '&') return -1;
2147 b_getch(input); /* get the & */
2151 return -3; /* "-" represents "close me" */
2153 while (isdigit(ch)) {
2161 bb_error_msg("ambiguous redirect");
2165 /* If a redirect is immediately preceded by a number, that number is
2166 * supposed to tell which file descriptor to redirect. This routine
2167 * looks for such preceding numbers. In an ideal world this routine
2168 * needs to handle all the following classes of redirects...
2169 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2170 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2171 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2172 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2173 * A -1 output from this program means no valid number was found, so the
2174 * caller should use the appropriate default for this redirection.
2176 static int redirect_opt_num(o_string *o)
2180 if (o->length==0) return -1;
2181 for(num=0; num<o->length; num++) {
2182 if (!isdigit(*(o->data+num))) {
2186 /* reuse num (and save an int) */
2192 static FILE *generate_stream_from_list(struct pipe *head)
2195 int pid, channel[2];
2196 if (pipe(channel)<0) bb_perror_msg_and_die("pipe");
2197 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
2203 bb_perror_msg_and_die("fork");
2204 } else if (pid==0) {
2206 if (channel[1] != 1) {
2210 _exit(run_list_real(head)); /* leaks memory */
2212 debug_printf("forked child %d\n",pid);
2214 pf = fdopen(channel[0],"r");
2215 debug_printf("pipe on FILE *%p\n",pf);
2219 /* this version hacked for testing purposes */
2220 /* return code is exit status of the process that is run. */
2221 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2224 o_string result=NULL_O_STRING;
2225 struct p_context inner;
2227 struct in_str pipe_str;
2228 initialize_context(&inner);
2230 /* recursion to generate command */
2231 retcode = parse_stream(&result, &inner, input, subst_end);
2232 if (retcode != 0) return retcode; /* syntax error or EOF */
2233 done_word(&result, &inner);
2234 done_pipe(&inner, PIPE_SEQ);
2237 p=generate_stream_from_list(inner.list_head);
2238 if (p==NULL) return 1;
2239 mark_open(fileno(p));
2240 setup_file_in_str(&pipe_str, p);
2242 /* now send results of command back into original context */
2243 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2244 /* XXX In case of a syntax error, should we try to kill the child?
2245 * That would be tough to do right, so just read until EOF. */
2247 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2250 debug_printf("done reading from pipe, pclose()ing\n");
2251 /* This is the step that wait()s for the child. Should be pretty
2252 * safe, since we just read an EOF from its stdout. We could try
2253 * to better, by using wait(), and keeping track of background jobs
2254 * at the same time. That would be a lot of work, and contrary
2255 * to the KISS philosophy of this program. */
2256 mark_closed(fileno(p));
2258 free_pipe_list(inner.list_head,0);
2259 debug_printf("pclosed, retcode=%d\n",retcode);
2260 /* XXX this process fails to trim a single trailing newline */
2264 static int parse_group(o_string *dest, struct p_context *ctx,
2265 struct in_str *input, int ch)
2268 struct p_context sub;
2269 struct child_prog *child = ctx->child;
2272 return 1; /* syntax error, groups and arglists don't mix */
2274 initialize_context(&sub);
2276 case '(': endch=')'; child->subshell=1; break;
2277 case '{': endch='}'; break;
2278 default: syntax(); /* really logic error */
2280 rcode=parse_stream(dest,&sub,input,endch);
2281 done_word(dest,&sub); /* finish off the final word in the subcontext */
2282 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2283 child->group = sub.list_head;
2285 /* child remains "open", available for possible redirects */
2288 /* basically useful version until someone wants to get fancier,
2289 * see the bash man page under "Parameter Expansion" */
2290 static char *lookup_param(char *src)
2296 p = get_local_var(src);
2301 /* return code: 0 for OK, 1 for syntax error */
2302 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2306 int ch = input->peek(input); /* first character after the $ */
2307 debug_printf("handle_dollar: ch=%c\n",ch);
2309 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2311 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2315 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2316 } else if (isdigit(ch)) {
2317 i = ch-'0'; /* XXX is $0 special? */
2318 if (i<global_argc) {
2319 parse_string(dest, ctx, global_argv[i]); /* recursion */
2322 } else switch (ch) {
2324 b_adduint(dest,getpid());
2328 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2332 b_adduint(dest,last_return_code);
2336 b_adduint(dest,global_argc ? global_argc-1 : 0);
2340 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2343 /* XXX maybe someone will try to escape the '}' */
2344 while(ch=b_getch(input),ch!=EOF && ch!='}') {
2351 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2355 process_command_subs(dest, ctx, input, ')');
2359 for (i=1; i<global_argc; i++) {
2360 parse_string(dest, ctx, global_argv[i]);
2361 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2367 /* still unhandled, but should be eventually */
2368 bb_error_msg("unhandled syntax: $%c",ch);
2372 b_addqchr(dest,'$',dest->quote);
2374 /* Eat the character if the flag was set. If the compiler
2375 * is smart enough, we could substitute "b_getch(input);"
2376 * for all the "advance = 1;" above, and also end up with
2377 * a nice size-optimized program. Hah! That'll be the day.
2379 if (advance) b_getch(input);
2383 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2386 setup_string_in_str(&foo, src);
2387 return parse_stream(dest, ctx, &foo, '\0');
2390 /* return code is 0 for normal exit, 1 for syntax error */
2391 int parse_stream(o_string *dest, struct p_context *ctx,
2392 struct in_str *input, int end_trigger)
2396 redir_type redir_style;
2399 /* Only double-quote state is handled in the state variable dest->quote.
2400 * A single-quote triggers a bypass of the main loop until its mate is
2401 * found. When recursing, quote state is passed in via dest->quote. */
2403 debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2404 while ((ch=b_getch(input))!=EOF) {
2406 next = (ch == '\n') ? 0 : b_peek(input);
2407 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2408 ch,ch,m,dest->quote);
2409 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2410 b_addqchr(dest, ch, dest->quote);
2412 if (m==2) { /* unquoted IFS */
2413 if (done_word(dest, ctx)) {
2416 /* If we aren't performing a substitution, treat a newline as a
2417 * command separator. */
2418 if (end_trigger != '\0' && ch=='\n')
2419 done_pipe(ctx,PIPE_SEQ);
2421 if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2422 debug_printf("leaving parse_stream (triggered)\n");
2425 if (m!=2) switch (ch) {
2427 if (dest->length == 0 && !dest->quote) {
2428 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2430 b_addqchr(dest, ch, dest->quote);
2438 b_addqchr(dest, '\\', dest->quote);
2439 b_addqchr(dest, b_getch(input), dest->quote);
2442 if (handle_dollar(dest, ctx, input)!=0) return 1;
2446 while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2456 dest->quote = !dest->quote;
2459 process_command_subs(dest, ctx, input, '`');
2462 redir_fd = redirect_opt_num(dest);
2463 done_word(dest, ctx);
2464 redir_style=REDIRECT_OVERWRITE;
2466 redir_style=REDIRECT_APPEND;
2468 } else if (next == '(') {
2469 syntax(); /* until we support >(list) Process Substitution */
2472 setup_redirect(ctx, redir_fd, redir_style, input);
2475 redir_fd = redirect_opt_num(dest);
2476 done_word(dest, ctx);
2477 redir_style=REDIRECT_INPUT;
2479 redir_style=REDIRECT_HEREIS;
2481 } else if (next == '>') {
2482 redir_style=REDIRECT_IO;
2484 } else if (next == '(') {
2485 syntax(); /* until we support <(list) Process Substitution */
2488 setup_redirect(ctx, redir_fd, redir_style, input);
2491 done_word(dest, ctx);
2492 done_pipe(ctx,PIPE_SEQ);
2495 done_word(dest, ctx);
2498 done_pipe(ctx,PIPE_AND);
2500 done_pipe(ctx,PIPE_BG);
2504 done_word(dest, ctx);
2507 done_pipe(ctx,PIPE_OR);
2509 /* we could pick up a file descriptor choice here
2510 * with redirect_opt_num(), but bash doesn't do it.
2511 * "echo foo 2| cat" yields "foo 2". */
2517 if (parse_group(dest, ctx, input, ch)!=0) return 1;
2521 syntax(); /* Proper use of this character caught by end_trigger */
2525 syntax(); /* this is really an internal logic error */
2530 /* complain if quote? No, maybe we just finished a command substitution
2531 * that was quoted. Example:
2532 * $ echo "`cat foo` plus more"
2533 * and we just got the EOF generated by the subshell that ran "cat foo"
2534 * The only real complaint is if we got an EOF when end_trigger != '\0',
2535 * that is, we were really supposed to get end_trigger, and never got
2536 * one before the EOF. Can't use the standard "syntax error" return code,
2537 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
2538 debug_printf("leaving parse_stream (EOF)\n");
2539 if (end_trigger != '\0') return -1;
2543 static void mapset(const char *set, int code)
2545 const unsigned char *s;
2546 for (s = (const unsigned char *)set; *s; s++) map[(int)*s] = code;
2549 static void update_ifs_map(void)
2551 /* char *ifs and char map[256] are both globals. */
2552 ifs = getenv("IFS");
2553 if (ifs == NULL) ifs=" \t\n";
2554 /* Precompute a list of 'flow through' behavior so it can be treated
2555 * quickly up front. Computation is necessary because of IFS.
2556 * Special case handling of IFS == " \t\n" is not implemented.
2557 * The map[] array only really needs two bits each, and on most machines
2558 * that would be faster because of the reduced L1 cache footprint.
2560 memset(map,0,sizeof(map)); /* most characters flow through always */
2561 mapset("\\$'\"`", 3); /* never flow through */
2562 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2563 mapset(ifs, 2); /* also flow through if quoted */
2566 /* most recursion does not come through here, the exception is
2567 * from builtin_source() */
2568 int parse_stream_outer(struct in_str *inp, int flag)
2571 struct p_context ctx;
2572 o_string temp=NULL_O_STRING;
2576 initialize_context(&ctx);
2578 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
2580 rcode = parse_stream(&temp, &ctx, inp, '\n');
2581 if (rcode != 1 && ctx.old_flag != 0) {
2584 if (rcode != 1 && ctx.old_flag == 0) {
2585 done_word(&temp, &ctx);
2586 done_pipe(&ctx,PIPE_SEQ);
2587 run_list(ctx.list_head);
2589 if (ctx.old_flag != 0) {
2596 free_pipe_list(ctx.list_head,0);
2599 } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
2603 static int parse_string_outer(const char *s, int flag)
2605 struct in_str input;
2606 setup_string_in_str(&input, s);
2607 return parse_stream_outer(&input, flag);
2610 static int parse_file_outer(FILE *f)
2613 struct in_str input;
2614 setup_file_in_str(&input, f);
2615 rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
2619 /* Make sure we have a controlling tty. If we get started under a job
2620 * aware app (like bash for example), make sure we are now in charge so
2621 * we don't fight over who gets the foreground */
2622 static void setup_job_control(void)
2624 static pid_t shell_pgrp;
2625 /* Loop until we are in the foreground. */
2626 while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
2627 kill (- shell_pgrp, SIGTTIN);
2629 /* Ignore interactive and job-control signals. */
2630 signal(SIGINT, SIG_IGN);
2631 signal(SIGQUIT, SIG_IGN);
2632 signal(SIGTERM, SIG_IGN);
2633 signal(SIGTSTP, SIG_IGN);
2634 signal(SIGTTIN, SIG_IGN);
2635 signal(SIGTTOU, SIG_IGN);
2636 signal(SIGCHLD, SIG_IGN);
2638 /* Put ourselves in our own process group. */
2640 shell_pgrp = getpid ();
2641 setpgid (shell_pgrp, shell_pgrp);
2643 /* Grab control of the terminal. */
2644 tcsetpgrp(shell_terminal, shell_pgrp);
2647 int hush_main(int argc, char **argv)
2653 /* XXX what should these be while sourcing /etc/profile? */
2657 /* (re?) initialize globals. Sometimes hush_main() ends up calling
2658 * hush_main(), therefore we cannot rely on the BSS to zero out this
2659 * stuff. Reset these to 0 every time. */
2661 /* map[] is taken care of with call to update_ifs_map() */
2664 close_me_head = NULL;
2669 /* Initialize some more globals to non-zero values */
2671 #ifdef CONFIG_FEATURE_COMMAND_EDITING
2672 cmdedit_set_initial_prompt();
2678 /* initialize our shell local variables with the values
2679 * currently living in the environment */
2682 set_local_var(*e, 2); /* without call putenv() */
2685 last_return_code=EXIT_SUCCESS;
2688 if (argv[0] && argv[0][0] == '-') {
2689 debug_printf("\nsourcing /etc/profile\n");
2690 if ((input = fopen("/etc/profile", "r")) != NULL) {
2691 mark_open(fileno(input));
2692 parse_file_outer(input);
2693 mark_closed(fileno(input));
2699 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2703 global_argv = argv+optind;
2704 global_argc = argc-optind;
2705 opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
2717 fprintf(stderr, "Usage: sh [FILE]...\n"
2718 " or: sh -c command [args]...\n\n");
2725 /* A shell is interactive if the `-i' flag was given, or if all of
2726 * the following conditions are met:
2728 * no arguments remaining or the -s flag given
2729 * standard input is a terminal
2730 * standard output is a terminal
2731 * Refer to Posix.2, the description of the `sh' utility. */
2732 if (argv[optind]==NULL && input==stdin &&
2733 isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
2737 debug_printf("\ninteractive=%d\n", interactive);
2739 /* Looks like they want an interactive shell */
2740 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
2741 printf( "\n\n%s hush - the humble shell v0.01 (testing)\n",
2743 printf( "Enter 'help' for a list of built-in commands.\n\n");
2745 setup_job_control();
2748 if (argv[optind]==NULL) {
2749 opt=parse_file_outer(stdin);
2753 debug_printf("\nrunning script '%s'\n", argv[optind]);
2754 global_argv = argv+optind;
2755 global_argc = argc-optind;
2756 input = bb_xfopen(argv[optind], "r");
2757 opt = parse_file_outer(input);
2759 #ifdef CONFIG_FEATURE_CLEAN_UP
2761 if (cwd && cwd != bb_msg_unknown)
2764 struct variables *cur, *tmp;
2765 for(cur = top_vars; cur; cur = tmp) {
2767 if (!cur->flg_read_only) {
2777 return(opt?opt:last_return_code);
2780 static char *insert_var_value(char *inp)
2782 int res_str_len = 0;
2785 char *p, *p1, *res_str = NULL;
2787 while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
2790 res_str = xrealloc(res_str, (res_str_len + len));
2791 strncpy((res_str + res_str_len), inp, len);
2795 p = strchr(inp, SPECIAL_VAR_SYMBOL);
2797 if ((p1 = lookup_param(inp))) {
2798 len = res_str_len + strlen(p1);
2799 res_str = xrealloc(res_str, (1 + len));
2800 strcpy((res_str + res_str_len), p1);
2803 *p = SPECIAL_VAR_SYMBOL;
2808 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
2809 strcpy((res_str + res_str_len), inp);
2810 while ((p = strchr(res_str, '\n'))) {
2814 return (res_str == NULL) ? inp : res_str;
2817 static char **make_list_in(char **inp, char *name)
2820 int name_len = strlen(name);
2825 /* create list of variable values */
2826 list = xmalloc(sizeof(*list));
2827 for (i = 0; inp[i]; i++) {
2828 p3 = insert_var_value(inp[i]);
2835 if ((p2 = strchr(p1, ' '))) {
2841 /* we use n + 2 in realloc for list,because we add
2842 * new element and then we will add NULL element */
2843 list = xrealloc(list, sizeof(*list) * (n + 2));
2844 list[n] = xmalloc(2 + name_len + len);
2845 strcpy(list[n], name);
2846 strcat(list[n], "=");
2847 strncat(list[n], p1, len);
2848 list[n++][name_len + len + 1] = '\0';
2851 if (p3 != inp[i]) free(p3);
2857 /* Make new string for parser */
2858 static char * make_string(char ** inp)
2865 for (n = 0; inp[n]; n++) {
2866 p = insert_var_value(inp[n]);
2867 str = xrealloc(str, (len + strlen(p)));
2874 len = strlen(str) + 3;
2875 if (p != inp[n]) free(p);
2878 *(str + len) = '\n';
2879 *(str + len + 1) = '\0';