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 <glob.h> /* glob, of course */
83 #include <getopt.h> /* should be pretty obvious */
85 //#include <sys/wait.h>
88 /* #include <dmalloc.h> */
89 /* #define DEBUG_SHELL */
92 #define SPECIAL_VAR_SYMBOL 03
93 #define FLAG_EXIT_FROM_LOOP 1
94 #define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
95 #define FLAG_REPARSING (1 << 2) /* >=2nd pass */
99 REDIRECT_OVERWRITE = 2,
105 /* The descrip member of this structure is only used to make debugging
107 static const struct {int mode; int default_fd; const char *descrip;} redir_table[] = {
109 { O_RDONLY, 0, "<" },
110 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
111 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
112 { O_RDONLY, -1, "<<" },
123 /* might eventually control execution */
140 #define FLAG_END (1<<RES_NONE)
141 #define FLAG_IF (1<<RES_IF)
142 #define FLAG_THEN (1<<RES_THEN)
143 #define FLAG_ELIF (1<<RES_ELIF)
144 #define FLAG_ELSE (1<<RES_ELSE)
145 #define FLAG_FI (1<<RES_FI)
146 #define FLAG_FOR (1<<RES_FOR)
147 #define FLAG_WHILE (1<<RES_WHILE)
148 #define FLAG_UNTIL (1<<RES_UNTIL)
149 #define FLAG_DO (1<<RES_DO)
150 #define FLAG_DONE (1<<RES_DONE)
151 #define FLAG_IN (1<<RES_IN)
152 #define FLAG_START (1<<RES_XXXX)
154 /* This holds pointers to the various results of parsing */
156 struct child_prog *child;
157 struct pipe *list_head;
159 struct redir_struct *pending_redirect;
161 int old_flag; /* for figuring out valid reserved words */
162 struct p_context *stack;
163 int type; /* define type of parser : ";$" common or special symbol */
164 /* How about quoting status? */
167 struct redir_struct {
168 redir_type type; /* type of redirection */
169 int fd; /* file descriptor being redirected */
170 int dup; /* -1, or file descriptor being duplicated */
171 struct redir_struct *next; /* pointer to the next redirect in the list */
172 glob_t word; /* *word.gl_pathv is the filename */
176 pid_t pid; /* 0 if exited */
177 char **argv; /* program name and arguments */
178 struct pipe *group; /* if non-NULL, first in group or subshell */
179 int subshell; /* flag, non-zero if group must be forked */
180 struct redir_struct *redirects; /* I/O redirections */
181 glob_t glob_result; /* result of parameter globbing */
182 int is_stopped; /* is the program currently running? */
183 struct pipe *family; /* pointer back to the child's parent pipe */
184 int sp; /* number of SPECIAL_VAR_SYMBOL */
189 int jobid; /* job number */
190 int num_progs; /* total number of programs in job */
191 int running_progs; /* number of programs running */
192 char *text; /* name of job */
193 char *cmdbuf; /* buffer various argv's point into */
194 pid_t pgrp; /* process group ID for the job */
195 struct child_prog *progs; /* array of commands in pipe */
196 struct pipe *next; /* to track background commands */
197 int stopped_progs; /* number of programs alive, but stopped */
198 int job_context; /* bitmask defining current context */
199 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
200 reserved_style r_mode; /* supports if, for, while, until */
205 struct close_me *next;
213 struct variables *next;
216 /* globals, connect us to the outside world
217 * the first three support $?, $#, and $1 */
218 static char **global_argv;
219 static int global_argc;
220 static int last_return_code;
221 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
223 /* "globals" within this file */
224 static const char *ifs;
225 static unsigned char map[256];
226 static int fake_mode;
227 static int interactive;
228 static struct close_me *close_me_head;
229 static const char *cwd;
230 static struct pipe *job_list;
231 static unsigned last_bg_pid;
232 static int last_jobid;
233 static unsigned shell_terminal;
234 static const char *PS1;
235 static const char *PS2;
236 static struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
237 static struct variables *top_vars = &shell_ver;
240 #define B_CHUNK (100)
250 #define NULL_O_STRING {NULL,0,0,0,0}
251 /* used for initialization:
252 o_string foo = NULL_O_STRING; */
254 /* I can almost use ordinary FILE *. Is open_memstream() universally
255 * available? Where is it documented? */
262 int (*get) (struct in_str *);
263 int (*peek) (struct in_str *);
265 #define b_getch(input) ((input)->get(input))
266 #define b_peek(input) ((input)->peek(input))
268 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
270 struct built_in_command {
271 const char *cmd; /* name */
272 const char *descr; /* description */
273 int (*function) (struct child_prog *); /* function ptr */
276 /* belongs in busybox.h */
277 static int max(int a, int b)
282 /* This should be in utility.c */
284 static void debug_printf(const char *format, ...)
287 va_start(args, format);
288 vfprintf(stderr, format, args);
291 /* broken, of course, but OK for testing */
292 static char *indenter(int i)
294 static char blanks[] = " ";
295 return &blanks[sizeof(blanks)-i-1];
298 #define debug_printf(...) do {;} while (0);
300 #define final_printf debug_printf
302 static void __syntax(const char *file, int line)
304 bb_error_msg("syntax error %s:%d", file, line);
306 // NB: was __FILE__, but that produces full path sometimess, so...
307 #define syntax() __syntax("hush.c", __LINE__)
309 /* Index of subroutines: */
310 /* function prototypes for builtins */
311 static int builtin_cd(struct child_prog *child);
312 static int builtin_env(struct child_prog *child);
313 static int builtin_eval(struct child_prog *child);
314 static int builtin_exec(struct child_prog *child);
315 static int builtin_exit(struct child_prog *child);
316 static int builtin_export(struct child_prog *child);
317 static int builtin_fg_bg(struct child_prog *child);
318 static int builtin_help(struct child_prog *child);
319 static int builtin_jobs(struct child_prog *child);
320 static int builtin_pwd(struct child_prog *child);
321 static int builtin_read(struct child_prog *child);
322 static int builtin_set(struct child_prog *child);
323 static int builtin_shift(struct child_prog *child);
324 static int builtin_source(struct child_prog *child);
325 static int builtin_umask(struct child_prog *child);
326 static int builtin_unset(struct child_prog *child);
327 static int builtin_not_written(struct child_prog *child);
328 /* o_string manipulation: */
329 static int b_check_space(o_string *o, int len);
330 static int b_addchr(o_string *o, int ch);
331 static void b_reset(o_string *o);
332 static int b_addqchr(o_string *o, int ch, int quote);
333 static int b_adduint(o_string *o, unsigned i);
334 /* in_str manipulations: */
335 static int static_get(struct in_str *i);
336 static int static_peek(struct in_str *i);
337 static int file_get(struct in_str *i);
338 static int file_peek(struct in_str *i);
339 static void setup_file_in_str(struct in_str *i, FILE *f);
340 static void setup_string_in_str(struct in_str *i, const char *s);
341 /* close_me manipulations: */
342 static void mark_open(int fd);
343 static void mark_closed(int fd);
344 static void close_all(void);
345 /* "run" the final data structures: */
346 static int free_pipe_list(struct pipe *head, int indent);
347 static int free_pipe(struct pipe *pi, int indent);
348 /* really run the final data structures: */
349 static int setup_redirects(struct child_prog *prog, int squirrel[]);
350 static int run_list_real(struct pipe *pi);
351 static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
352 static int run_pipe_real(struct pipe *pi);
353 /* extended glob support: */
354 static int globhack(const char *src, int flags, glob_t *pglob);
355 static int glob_needed(const char *s);
356 static int xglob(o_string *dest, int flags, glob_t *pglob);
357 /* variable assignment: */
358 static int is_assignment(const char *s);
359 /* data structure manipulation: */
360 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
361 static void initialize_context(struct p_context *ctx);
362 static int done_word(o_string *dest, struct p_context *ctx);
363 static int done_command(struct p_context *ctx);
364 static int done_pipe(struct p_context *ctx, pipe_style type);
365 /* primary string parsing: */
366 static int redirect_dup_num(struct in_str *input);
367 static int redirect_opt_num(o_string *o);
368 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
369 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
370 static const char *lookup_param(const char *src);
371 static char *make_string(char **inp);
372 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
373 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
374 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
376 static int parse_stream_outer(struct in_str *inp, int flag);
377 static int parse_string_outer(const char *s, int flag);
378 static int parse_file_outer(FILE *f);
379 /* job management: */
380 static int checkjobs(struct pipe* fg_pipe);
381 static void insert_bg_job(struct pipe *pi);
382 static void remove_bg_job(struct pipe *pi);
383 /* local variable support */
384 static char **make_list_in(char **inp, char *name);
385 static char *insert_var_value(char *inp);
386 static const char *get_local_var(const char *var);
387 static void unset_local_var(const char *name);
388 static int set_local_var(const char *s, int flg_export);
390 /* Table of built-in functions. They can be forked or not, depending on
391 * context: within pipes, they fork. As simple commands, they do not.
392 * When used in non-forking context, they can change global variables
393 * in the parent shell process. If forked, of course they cannot.
394 * For example, 'unset foo | whatever' will parse and run, but foo will
395 * still be set at the end. */
396 static const struct built_in_command bltins[] = {
397 { "bg", "Resume a job in the background", builtin_fg_bg },
398 { "break", "Exit for, while or until loop", builtin_not_written },
399 { "cd", "Change working directory", builtin_cd },
400 { "continue", "Continue for, while or until loop", builtin_not_written },
401 { "env", "Print all environment variables", builtin_env },
402 { "eval", "Construct and run shell command", builtin_eval },
403 { "exec", "Exec command, replacing this shell with the exec'd process",
405 { "exit", "Exit from shell()", builtin_exit },
406 { "export", "Set environment variable", builtin_export },
407 { "fg", "Bring job into the foreground", builtin_fg_bg },
408 { "jobs", "Lists the active jobs", builtin_jobs },
409 { "pwd", "Print current directory", builtin_pwd },
410 { "read", "Input environment variable", builtin_read },
411 { "return", "Return from a function", builtin_not_written },
412 { "set", "Set/unset shell local variables", builtin_set },
413 { "shift", "Shift positional parameters", builtin_shift },
414 { "trap", "Trap signals", builtin_not_written },
415 { "ulimit","Controls resource limits", builtin_not_written },
416 { "umask","Sets file creation mask", builtin_umask },
417 { "unset", "Unset environment variable", builtin_unset },
418 { ".", "Source-in and run commands in a file", builtin_source },
419 { "help", "List shell built-in commands", builtin_help },
423 static const char *set_cwd(void)
425 if (cwd == bb_msg_unknown)
426 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) called free(arg) */
427 cwd = xrealloc_getcwd_or_warn((char *)cwd);
429 cwd = bb_msg_unknown;
433 /* built-in 'eval' handler */
434 static int builtin_eval(struct child_prog *child)
437 int rcode = EXIT_SUCCESS;
439 if (child->argv[1]) {
440 str = make_string(child->argv + 1);
441 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
442 FLAG_PARSE_SEMICOLON);
444 rcode = last_return_code;
449 /* built-in 'cd <path>' handler */
450 static int builtin_cd(struct child_prog *child)
453 if (child->argv[1] == NULL)
454 newdir = getenv("HOME");
456 newdir = child->argv[1];
458 printf("cd: %s: %s\n", newdir, strerror(errno));
465 /* built-in 'env' handler */
466 static int builtin_env(struct child_prog *dummy ATTRIBUTE_UNUSED)
477 /* built-in 'exec' handler */
478 static int builtin_exec(struct child_prog *child)
480 if (child->argv[1] == NULL)
481 return EXIT_SUCCESS; /* Really? */
487 /* built-in 'exit' handler */
488 static int builtin_exit(struct child_prog *child)
490 if (child->argv[1] == NULL)
491 exit(last_return_code);
492 exit (atoi(child->argv[1]));
495 /* built-in 'export VAR=value' handler */
496 static int builtin_export(struct child_prog *child)
499 char *name = child->argv[1];
502 return builtin_env(child);
508 const char *value = strchr(name, '=');
512 /* They are exporting something without an =VALUE */
514 value = get_local_var(name);
516 size_t ln = strlen(name);
518 tmp = realloc(name, ln+strlen(value)+2);
522 sprintf(tmp+ln, "=%s", value);
526 /* bash does not return an error when trying to export
527 * an undefined variable. Do likewise. */
533 bb_perror_msg("export");
535 res = set_local_var(name, 1);
542 /* built-in 'fg' and 'bg' handler */
543 static int builtin_fg_bg(struct child_prog *child)
546 struct pipe *pi = NULL;
550 /* If they gave us no args, assume they want the last backgrounded task */
551 if (!child->argv[1]) {
552 for (pi = job_list; pi; pi = pi->next) {
553 if (pi->jobid == last_jobid) {
558 bb_error_msg("%s: no current job", child->argv[0]);
562 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
563 bb_error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
566 for (pi = job_list; pi; pi = pi->next) {
567 if (pi->jobid == jobnum) {
572 bb_error_msg("%s: %d: no such job", child->argv[0], jobnum);
577 if (*child->argv[0] == 'f') {
578 /* Put the job into the foreground. */
579 tcsetpgrp(shell_terminal, pi->pgrp);
582 /* Restart the processes in the job */
583 for (i = 0; i < pi->num_progs; i++)
584 pi->progs[i].is_stopped = 0;
586 i = kill(- pi->pgrp, SIGCONT);
591 bb_perror_msg("kill (SIGCONT)");
595 pi->stopped_progs = 0;
599 /* built-in 'help' handler */
600 static int builtin_help(struct child_prog *dummy ATTRIBUTE_UNUSED)
602 const struct built_in_command *x;
604 printf("\nBuilt-in commands:\n");
605 printf("-------------------\n");
606 for (x = bltins; x->cmd; x++) {
607 if (x->descr == NULL)
609 printf("%s\t%s\n", x->cmd, x->descr);
615 /* built-in 'jobs' handler */
616 static int builtin_jobs(struct child_prog *child ATTRIBUTE_UNUSED)
619 const char *status_string;
621 for (job = job_list; job; job = job->next) {
622 if (job->running_progs == job->stopped_progs)
623 status_string = "Stopped";
625 status_string = "Running";
627 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
633 /* built-in 'pwd' handler */
634 static int builtin_pwd(struct child_prog *dummy ATTRIBUTE_UNUSED)
640 /* built-in 'read VAR' handler */
641 static int builtin_read(struct child_prog *child)
645 if (child->argv[1]) {
649 string[0] = '\0'; /* In case stdin has only EOF */
651 fgets(string, sizeof(string), stdin);
653 var = malloc(strlen(child->argv[1]) + strlen(string) + 2);
655 sprintf(var, "%s=%s", child->argv[1], string);
656 res = set_local_var(var, 0);
660 bb_perror_msg("read");
661 free(var); /* So not move up to avoid breaking errno */
664 do res = getchar(); while (res != '\n' && res != EOF);
668 /* built-in 'set VAR=value' handler */
669 static int builtin_set(struct child_prog *child)
671 char *temp = child->argv[1];
675 for (e = top_vars; e; e = e->next)
676 printf("%s=%s\n", e->name, e->value);
678 set_local_var(temp, 0);
684 /* Built-in 'shift' handler */
685 static int builtin_shift(struct child_prog *child)
688 if (child->argv[1]) {
689 n = atoi(child->argv[1]);
691 if (n >= 0 && n < global_argc) {
692 /* XXX This probably breaks $0 */
701 /* Built-in '.' handler (read-in and execute commands from file) */
702 static int builtin_source(struct child_prog *child)
707 if (child->argv[1] == NULL)
710 /* XXX search through $PATH is missing */
711 input = fopen(child->argv[1], "r");
713 bb_error_msg("cannot open '%s'", child->argv[1]);
717 /* Now run the file */
718 /* XXX argv and argc are broken; need to save old global_argv
719 * (pointer only is OK!) on this stack frame,
720 * set global_argv=child->argv+1, recurse, and restore. */
721 mark_open(fileno(input));
722 status = parse_file_outer(input);
723 mark_closed(fileno(input));
728 static int builtin_umask(struct child_prog *child)
731 const char *arg = child->argv[1];
734 new_umask = strtoul(arg, &end, 8);
735 if (*end != '\0' || end == arg) {
739 new_umask = umask(0);
740 printf("%.3o\n", (unsigned) new_umask);
746 /* built-in 'unset VAR' handler */
747 static int builtin_unset(struct child_prog *child)
749 /* bash returned already true */
750 unset_local_var(child->argv[1]);
754 static int builtin_not_written(struct child_prog *child)
756 printf("builtin_%s not written\n", child->argv[0]);
760 static int b_check_space(o_string *o, int len)
762 /* It would be easy to drop a more restrictive policy
763 * in here, such as setting a maximum string length */
764 if (o->length + len > o->maxlen) {
765 char *old_data = o->data;
766 /* assert (data == NULL || o->maxlen != 0); */
767 o->maxlen += max(2*len, B_CHUNK);
768 o->data = realloc(o->data, 1 + o->maxlen);
769 if (o->data == NULL) {
773 return o->data == NULL;
776 static int b_addchr(o_string *o, int ch)
778 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
779 if (b_check_space(o, 1))
781 o->data[o->length] = ch;
783 o->data[o->length] = '\0';
787 static void b_reset(o_string *o)
795 static void b_free(o_string *o)
803 /* My analysis of quoting semantics tells me that state information
804 * is associated with a destination, not a source.
806 static int b_addqchr(o_string *o, int ch, int quote)
808 if (quote && strchr("*?[\\",ch)) {
810 rc = b_addchr(o, '\\');
814 return b_addchr(o, ch);
817 /* belongs in utility.c */
818 static char *simple_itoa(unsigned i)
820 static char local[sizeof(int)*3 + 2];
821 char *p = &local[sizeof(int)*3 + 2 - 1];
830 static int b_adduint(o_string *o, unsigned i)
833 char *p = simple_itoa(i);
834 /* no escape checking necessary */
835 do r = b_addchr(o, *p++); while (r == 0 && *p);
839 static int static_get(struct in_str *i)
842 if (ch == '\0') return EOF;
846 static int static_peek(struct in_str *i)
851 static void cmdedit_set_initial_prompt(void)
853 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
862 static const char* setup_prompt_string(int promptmode)
864 const char *prompt_str;
865 debug_printf("setup_prompt_string %d ", promptmode);
866 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
867 /* Set up the prompt */
868 if (promptmode == 1) {
871 ns = xmalloc(strlen(cwd)+4);
872 sprintf(ns, "%s %s", cwd, (geteuid() != 0) ? "$ " : "# ");
879 prompt_str = (promptmode == 1) ? PS1 : PS2;
881 debug_printf("result %s\n", prompt_str);
885 #if ENABLE_FEATURE_EDITING
886 static line_input_t *line_input_state;
889 static void get_user_input(struct in_str *i)
891 const char *prompt_str;
892 static char the_command[BUFSIZ];
894 prompt_str = setup_prompt_string(i->promptmode);
895 #if ENABLE_FEATURE_EDITING
897 ** enable command line editing only while a command line
898 ** is actually being read; otherwise, we'll end up bequeathing
899 ** atexit() handlers and other unwanted stuff to our
900 ** child processes (rob@sysgo.de)
902 read_line_input(prompt_str, the_command, BUFSIZ, line_input_state);
904 fputs(prompt_str, stdout);
906 the_command[0] = fgetc(i->file);
907 the_command[1] = '\0';
913 /* This is the magic location that prints prompts
914 * and gets data back from the user */
915 static int file_get(struct in_str *i)
920 /* If there is data waiting, eat it up */
924 /* need to double check i->file because we might be doing something
925 * more complicated by now, like sourcing or substituting. */
926 if (i->__promptme && interactive && i->file == stdin) {
927 while (!i->p || !(interactive && strlen(i->p))) {
939 debug_printf("b_getch: got a %d\n", ch);
946 /* All the callers guarantee this routine will never be
947 * used right after a newline, so prompting is not needed.
949 static int file_peek(struct in_str *i)
954 i->peek_buf[0] = fgetc(i->file);
955 i->peek_buf[1] = '\0';
957 debug_printf("b_peek: got a %d\n", *i->p);
962 static void setup_file_in_str(struct in_str *i, FILE *f)
972 static void setup_string_in_str(struct in_str *i, const char *s)
974 i->peek = static_peek;
981 static void mark_open(int fd)
983 struct close_me *new = xmalloc(sizeof(struct close_me));
985 new->next = close_me_head;
989 static void mark_closed(int fd)
991 struct close_me *tmp;
992 if (close_me_head == NULL || close_me_head->fd != fd)
993 bb_error_msg_and_die("corrupt close_me");
995 close_me_head = close_me_head->next;
999 static void close_all(void)
1002 for (c = close_me_head; c; c = c->next) {
1005 close_me_head = NULL;
1008 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1009 * and stderr if they are redirected. */
1010 static int setup_redirects(struct child_prog *prog, int squirrel[])
1013 struct redir_struct *redir;
1015 for (redir = prog->redirects; redir; redir = redir->next) {
1016 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1017 /* something went wrong in the parse. Pretend it didn't happen */
1020 if (redir->dup == -1) {
1021 mode = redir_table[redir->type].mode;
1022 openfd = open(redir->word.gl_pathv[0], mode, 0666);
1024 /* this could get lost if stderr has been redirected, but
1025 bash and ash both lose it as well (though zsh doesn't!) */
1026 bb_perror_msg("error opening %s", redir->word.gl_pathv[0]);
1030 openfd = redir->dup;
1033 if (openfd != redir->fd) {
1034 if (squirrel && redir->fd < 3) {
1035 squirrel[redir->fd] = dup(redir->fd);
1040 dup2(openfd, redir->fd);
1041 if (redir->dup == -1)
1049 static void restore_redirects(int squirrel[])
1052 for (i = 0; i < 3; i++) {
1055 /* No error checking. I sure wouldn't know what
1056 * to do with an error if I found one! */
1064 /* XXX no exit() here. If you don't exec, use _exit instead.
1065 * The at_exit handlers apparently confuse the calling process,
1066 * in particular stdin handling. Not sure why? */
1067 static void pseudo_exec(struct child_prog *child)
1071 const struct built_in_command *x;
1073 for (i = 0; is_assignment(child->argv[i]); i++) {
1074 debug_printf("pid %d environment modification: %s\n",
1075 getpid(), child->argv[i]);
1076 p = insert_var_value(child->argv[i]);
1078 if (p != child->argv[i])
1081 child->argv += i; /* XXX this hack isn't so horrible, since we are about
1082 to exit, and therefore don't need to keep data
1083 structures consistent for free() use. */
1084 /* If a variable is assigned in a forest, and nobody listens,
1085 * was it ever really set?
1087 if (child->argv[0] == NULL) {
1088 _exit(EXIT_SUCCESS);
1092 * Check if the command matches any of the builtins.
1093 * Depending on context, this might be redundant. But it's
1094 * easier to waste a few CPU cycles than it is to figure out
1095 * if this is one of those cases.
1097 for (x = bltins; x->cmd; x++) {
1098 if (strcmp(child->argv[0], x->cmd) == 0) {
1099 debug_printf("builtin exec %s\n", child->argv[0]);
1100 rcode = x->function(child);
1106 /* Check if the command matches any busybox internal commands
1108 * FIXME: This feature is not 100% safe, since
1109 * BusyBox is not fully reentrant, so we have no guarantee the things
1110 * from the .bss are still zeroed, or that things from .data are still
1111 * at their defaults. We could exec ourself from /proc/self/exe, but I
1112 * really dislike relying on /proc for things. We could exec ourself
1113 * from global_argv[0], but if we are in a chroot, we may not be able
1114 * to find ourself... */
1115 #if ENABLE_FEATURE_SH_STANDALONE_SHELL
1118 char** argv_l = child->argv;
1119 char *name = child->argv[0];
1121 /* Count argc for use in a second... */
1122 for (argc_l = 0; *argv_l; argv_l++, argc_l++)
1125 debug_printf("running applet %s\n", name);
1126 run_applet_by_name(name, argc_l, child->argv);
1129 debug_printf("exec of %s\n", child->argv[0]);
1130 execvp(child->argv[0], child->argv);
1131 bb_perror_msg("cannot exec: %s", child->argv[0]);
1133 } else if (child->group) {
1134 debug_printf("runtime nesting to group\n");
1135 interactive = 0; /* crucial!!!! */
1136 rcode = run_list_real(child->group);
1137 /* OK to leak memory by not calling free_pipe_list,
1138 * since this process is about to exit */
1141 /* Can happen. See what bash does with ">foo" by itself. */
1142 debug_printf("trying to pseudo_exec null command\n");
1143 _exit(EXIT_SUCCESS);
1147 static void insert_bg_job(struct pipe *pi)
1149 struct pipe *thejob;
1151 /* Linear search for the ID of the job to use */
1153 for (thejob = job_list; thejob; thejob = thejob->next)
1154 if (thejob->jobid >= pi->jobid)
1155 pi->jobid = thejob->jobid + 1;
1157 /* add thejob to the list of running jobs */
1159 thejob = job_list = xmalloc(sizeof(*thejob));
1161 for (thejob = job_list; thejob->next; thejob = thejob->next)
1163 thejob->next = xmalloc(sizeof(*thejob));
1164 thejob = thejob->next;
1167 /* physically copy the struct job */
1168 memcpy(thejob, pi, sizeof(struct pipe));
1169 thejob->next = NULL;
1170 thejob->running_progs = thejob->num_progs;
1171 thejob->stopped_progs = 0;
1172 thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1174 //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
1176 char *bar = thejob->text;
1177 char **foo = pi->progs[0].argv;
1180 bar += sprintf(bar, "%s ", *foo++);
1183 /* we don't wait for background thejobs to return -- append it
1184 to the list of backgrounded thejobs and leave it alone */
1185 printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1186 last_bg_pid = thejob->progs[0].pid;
1187 last_jobid = thejob->jobid;
1190 /* remove a backgrounded job */
1191 static void remove_bg_job(struct pipe *pi)
1193 struct pipe *prev_pipe;
1195 if (pi == job_list) {
1196 job_list = pi->next;
1198 prev_pipe = job_list;
1199 while (prev_pipe->next != pi)
1200 prev_pipe = prev_pipe->next;
1201 prev_pipe->next = pi->next;
1204 last_jobid = job_list->jobid;
1208 pi->stopped_progs = 0;
1213 /* Checks to see if any processes have exited -- if they
1214 have, figure out why and see if a job has completed */
1215 static int checkjobs(struct pipe* fg_pipe)
1223 attributes = WUNTRACED;
1224 if (fg_pipe == NULL) {
1225 attributes |= WNOHANG;
1228 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1231 for (i = 0; i < fg_pipe->num_progs; i++) {
1232 if (fg_pipe->progs[i].pid == childpid) {
1233 if (i == fg_pipe->num_progs-1)
1234 rcode = WEXITSTATUS(status);
1235 fg_pipe->num_progs--;
1241 for (pi = job_list; pi; pi = pi->next) {
1243 while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1246 if (prognum < pi->num_progs)
1251 debug_printf("checkjobs: pid %d was not in our list!\n",
1256 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1258 pi->running_progs--;
1259 pi->progs[prognum].pid = 0;
1261 if (!pi->running_progs) {
1262 printf(JOB_STATUS_FORMAT, pi->jobid,
1268 pi->stopped_progs++;
1269 pi->progs[prognum].is_stopped = 1;
1273 if (childpid == -1 && errno != ECHILD)
1274 bb_perror_msg("waitpid");
1276 /* move the shell to the foreground */
1277 //if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
1278 // bb_perror_msg("tcsetpgrp-2");
1282 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1283 * to finish. See checkjobs().
1285 * return code is normally -1, when the caller has to wait for children
1286 * to finish to determine the exit status of the pipe. If the pipe
1287 * is a simple builtin command, however, the action is done by the
1288 * time run_pipe_real returns, and the exit code is provided as the
1291 * The input of the pipe is always stdin, the output is always
1292 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1293 * because it tries to avoid running the command substitution in
1294 * subshell, when that is in fact necessary. The subshell process
1295 * now has its stdout directed to the input of the appropriate pipe,
1296 * so this routine is noticeably simpler.
1298 static int run_pipe_real(struct pipe *pi)
1301 int nextin, nextout;
1302 int pipefds[2]; /* pipefds[0] is for reading */
1303 struct child_prog *child;
1304 const struct built_in_command *x;
1310 /* Check if this is a simple builtin (not part of a pipe).
1311 * Builtins within pipes have to fork anyway, and are handled in
1312 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1314 child = &(pi->progs[0]);
1315 if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1316 int squirrel[] = { -1, -1, -1 };
1318 debug_printf("non-subshell grouping\n");
1319 setup_redirects(child, squirrel);
1320 /* XXX could we merge code with following builtin case,
1321 * by creating a pseudo builtin that calls run_list_real? */
1322 rcode = run_list_real(child->group);
1323 restore_redirects(squirrel);
1325 } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1326 for (i = 0; is_assignment(child->argv[i]); i++)
1328 if (i != 0 && child->argv[i] == NULL) {
1329 /* assignments, but no command: set the local environment */
1330 for (i = 0; child->argv[i] != NULL; i++) {
1331 /* Ok, this case is tricky. We have to decide if this is a
1332 * local variable, or an already exported variable. If it is
1333 * already exported, we have to export the new value. If it is
1334 * not exported, we need only set this as a local variable.
1335 * This junk is all to decide whether or not to export this
1339 name = xstrdup(child->argv[i]);
1340 debug_printf("Local environment set: %s\n", name);
1341 value = strchr(name, '=');
1344 if (get_local_var(name)) {
1348 p = insert_var_value(child->argv[i]);
1349 set_local_var(p, export_me);
1350 if (p != child->argv[i])
1353 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1355 for (i = 0; is_assignment(child->argv[i]); i++) {
1356 p = insert_var_value(child->argv[i]);
1358 if (p != child->argv[i]) {
1366 str = make_string((child->argv + i));
1367 parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1369 return last_return_code;
1371 for (x = bltins; x->cmd; x++) {
1372 if (strcmp(child->argv[i], x->cmd) == 0) {
1373 int squirrel[] = { -1, -1, -1 };
1375 if (x->function == builtin_exec && child->argv[i+1] == NULL) {
1376 debug_printf("magic exec\n");
1377 setup_redirects(child,NULL);
1378 return EXIT_SUCCESS;
1380 debug_printf("builtin inline %s\n", child->argv[0]);
1381 /* XXX setup_redirects acts on file descriptors, not FILEs.
1382 * This is perfect for work that comes after exec().
1383 * Is it really safe for inline use? Experimentally,
1384 * things seem to work with glibc. */
1385 setup_redirects(child, squirrel);
1386 child->argv += i; /* XXX horrible hack */
1387 rcode = x->function(child);
1388 child->argv -= i; /* XXX restore hack so free() can work right */
1389 restore_redirects(squirrel);
1395 for (i = 0; i < pi->num_progs; i++) {
1396 child = &(pi->progs[i]);
1398 /* pipes are inserted between pairs of commands */
1399 if ((i + 1) < pi->num_progs) {
1400 if (pipe(pipefds) < 0)
1401 bb_perror_msg_and_die("pipe");
1402 nextout = pipefds[1];
1408 /* XXX test for failed fork()? */
1409 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
1410 child->pid = fork();
1412 child->pid = vfork();
1415 /* Set the handling for job control signals back to the default. */
1416 signal(SIGINT, SIG_DFL);
1417 signal(SIGQUIT, SIG_DFL);
1418 signal(SIGTERM, SIG_DFL);
1419 signal(SIGTSTP, SIG_DFL);
1420 signal(SIGTTIN, SIG_DFL);
1421 signal(SIGTTOU, SIG_DFL);
1422 signal(SIGCHLD, SIG_DFL);
1434 if (pipefds[0] != -1) {
1435 close(pipefds[0]); /* opposite end of our output pipe */
1438 /* Like bash, explicit redirects override pipes,
1439 * and the pipe fd is available for dup'ing. */
1440 setup_redirects(child,NULL);
1442 if (interactive && pi->followup != PIPE_BG) {
1443 /* If we (the child) win the race, put ourselves in the process
1444 * group whose leader is the first process in this pipe. */
1446 pi->pgrp = getpid();
1448 if (setpgid(0, pi->pgrp) == 0) {
1449 tcsetpgrp(2, pi->pgrp);
1456 /* put our child in the process group whose leader is the
1457 first process in this pipe */
1459 pi->pgrp = child->pid;
1461 /* Don't check for errors. The child may be dead already,
1462 * in which case setpgid returns error code EACCES. */
1463 setpgid(child->pid, pi->pgrp);
1470 /* If there isn't another process, nextin is garbage
1471 but it doesn't matter */
1472 nextin = pipefds[0];
1477 static int run_list_real(struct pipe *pi)
1479 char *save_name = NULL;
1481 char **save_list = NULL;
1485 int rcode = 0, flag_skip = 1;
1486 int flag_restore = 0;
1487 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
1488 reserved_style rmode, skip_more_in_this_rmode = RES_XXXX;
1489 /* check syntax for "for" */
1490 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1491 if ((rpipe->r_mode == RES_IN || rpipe->r_mode == RES_FOR)
1492 && (rpipe->next == NULL)
1497 if ((rpipe->r_mode == RES_IN && rpipe->next->r_mode == RES_IN && rpipe->next->progs->argv != NULL)
1498 || (rpipe->r_mode == RES_FOR && rpipe->next->r_mode != RES_IN)
1504 for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1505 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL
1506 || pi->r_mode == RES_FOR
1515 debug_printf("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n",
1516 rmode, if_code, next_if_code, skip_more_in_this_rmode);
1517 if (rmode == skip_more_in_this_rmode && flag_skip) {
1518 if (pi->followup == PIPE_SEQ)
1523 skip_more_in_this_rmode = RES_XXXX;
1524 if (rmode == RES_THEN || rmode == RES_ELSE)
1525 if_code = next_if_code;
1526 if (rmode == RES_THEN && if_code)
1528 if (rmode == RES_ELSE && !if_code)
1530 if (rmode == RES_ELIF && !if_code)
1532 if (rmode == RES_FOR && pi->num_progs) {
1534 /* if no variable values after "in" we skip "for" */
1535 if (!pi->next->progs->argv)
1537 /* create list of variable values */
1538 list = make_list_in(pi->next->progs->argv,
1539 pi->progs->argv[0]);
1541 save_name = pi->progs->argv[0];
1542 pi->progs->argv[0] = NULL;
1546 free(pi->progs->argv[0]);
1550 pi->progs->argv[0] = save_name;
1551 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
1554 /* insert new value from list for variable */
1555 if (pi->progs->argv[0])
1556 free(pi->progs->argv[0]);
1557 pi->progs->argv[0] = *list++;
1558 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
1561 if (rmode == RES_IN)
1563 if (rmode == RES_DO) {
1567 if ((rmode == RES_DONE)) {
1574 if (pi->num_progs == 0)
1576 save_num_progs = pi->num_progs; /* save number of programs */
1577 rcode = run_pipe_real(pi);
1578 debug_printf("run_pipe_real returned %d\n",rcode);
1580 /* We only ran a builtin: rcode was set by the return value
1581 * of run_pipe_real(), and we don't need to wait for anything. */
1582 } else if (pi->followup == PIPE_BG) {
1583 /* XXX check bash's behavior with nontrivial pipes */
1584 /* XXX compute jobid */
1585 /* XXX what does bash do with attempts to background builtins? */
1587 rcode = EXIT_SUCCESS;
1590 /* move the new process group into the foreground */
1591 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1592 bb_perror_msg("tcsetpgrp-3");
1593 rcode = checkjobs(pi);
1594 /* move the shell to the foreground */
1595 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1596 bb_perror_msg("tcsetpgrp-4");
1598 rcode = checkjobs(pi);
1600 debug_printf("checkjobs returned %d\n",rcode);
1602 last_return_code = rcode;
1603 pi->num_progs = save_num_progs; /* restore number of programs */
1604 if ( rmode == RES_IF || rmode == RES_ELIF )
1605 next_if_code = rcode; /* can be overwritten a number of times */
1606 if (rmode == RES_WHILE)
1607 flag_rep = !last_return_code;
1608 if (rmode == RES_UNTIL)
1609 flag_rep = last_return_code;
1610 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
1611 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
1613 skip_more_in_this_rmode = rmode;
1620 /* return code is the exit status of the pipe */
1621 static int free_pipe(struct pipe *pi, int indent)
1624 struct child_prog *child;
1625 struct redir_struct *r, *rnext;
1626 int a, i, ret_code = 0;
1628 if (pi->stopped_progs > 0)
1630 final_printf("%s run pipe: (pid %d)\n", indenter(indent), getpid());
1631 for (i = 0; i < pi->num_progs; i++) {
1632 child = &pi->progs[i];
1633 final_printf("%s command %d:\n", indenter(indent), i);
1635 for (a = 0, p = child->argv; *p; a++, p++) {
1636 final_printf("%s argv[%d] = %s\n", indenter(indent), a, *p);
1638 globfree(&child->glob_result);
1640 } else if (child->group) {
1641 final_printf("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
1642 ret_code = free_pipe_list(child->group, indent+3);
1643 final_printf("%s end group\n", indenter(indent));
1645 final_printf("%s (nil)\n", indenter(indent));
1647 for (r = child->redirects; r; r = rnext) {
1648 final_printf("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
1650 /* guard against the case >$FOO, where foo is unset or blank */
1651 if (r->word.gl_pathv) {
1652 final_printf(" %s\n", *r->word.gl_pathv);
1656 final_printf("&%d\n", r->dup);
1661 child->redirects = NULL;
1663 free(pi->progs); /* children are an array, they get freed all at once */
1668 static int free_pipe_list(struct pipe *head, int indent)
1670 int rcode = 0; /* if list has no members */
1671 struct pipe *pi, *next;
1672 for (pi = head; pi; pi = next) {
1673 final_printf("%s pipe reserved mode %d\n", indenter(indent), pi->r_mode);
1674 rcode = free_pipe(pi, indent);
1675 final_printf("%s pipe followup code %d\n", indenter(indent), pi->followup);
1683 /* Select which version we will use */
1684 static int run_list(struct pipe *pi)
1687 if (fake_mode == 0) {
1688 rcode = run_list_real(pi);
1690 /* free_pipe_list has the side effect of clearing memory
1691 * In the long run that function can be merged with run_list_real,
1692 * but doing that now would hobble the debugging effort. */
1693 free_pipe_list(pi,0);
1697 /* The API for glob is arguably broken. This routine pushes a non-matching
1698 * string into the output structure, removing non-backslashed backslashes.
1699 * If someone can prove me wrong, by performing this function within the
1700 * original glob(3) api, feel free to rewrite this routine into oblivion.
1701 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1702 * XXX broken if the last character is '\\', check that before calling.
1704 static int globhack(const char *src, int flags, glob_t *pglob)
1709 for (cnt = 1, s = src; s && *s; s++) {
1710 if (*s == '\\') s++;
1714 if (!dest) return GLOB_NOSPACE;
1715 if (!(flags & GLOB_APPEND)) {
1716 pglob->gl_pathv = NULL;
1717 pglob->gl_pathc = 0;
1721 pathc = ++pglob->gl_pathc;
1722 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1723 if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
1724 pglob->gl_pathv[pathc-1] = dest;
1725 pglob->gl_pathv[pathc] = NULL;
1726 for (s = src; s && *s; s++, dest++) {
1727 if (*s == '\\') s++;
1734 /* XXX broken if the last character is '\\', check that before calling */
1735 static int glob_needed(const char *s)
1738 if (*s == '\\') s++;
1739 if (strchr("*[?", *s)) return 1;
1744 static int xglob(o_string *dest, int flags, glob_t *pglob)
1748 /* short-circuit for null word */
1749 /* we can code this better when the debug_printf's are gone */
1750 if (dest->length == 0) {
1751 if (dest->nonnull) {
1752 /* bash man page calls this an "explicit" null */
1753 gr = globhack(dest->data, flags, pglob);
1754 debug_printf("globhack returned %d\n", gr);
1758 } else if (glob_needed(dest->data)) {
1759 gr = glob(dest->data, flags, NULL, pglob);
1760 debug_printf("glob returned %d\n", gr);
1761 if (gr == GLOB_NOMATCH) {
1762 /* quote removal, or more accurately, backslash removal */
1763 gr = globhack(dest->data, flags, pglob);
1764 debug_printf("globhack returned %d\n", gr);
1767 gr = globhack(dest->data, flags, pglob);
1768 debug_printf("globhack returned %d\n", gr);
1770 if (gr == GLOB_NOSPACE)
1771 bb_error_msg_and_die("out of memory during glob");
1772 if (gr != 0) { /* GLOB_ABORTED ? */
1773 bb_error_msg("glob(3) error %d", gr);
1775 /* globprint(glob_target); */
1779 /* This is used to get/check local shell variables */
1780 static const char *get_local_var(const char *s)
1782 struct variables *cur;
1786 for (cur = top_vars; cur; cur = cur->next)
1787 if (strcmp(cur->name, s) == 0)
1792 /* This is used to set local shell variables
1793 flg_export == 0 if only local (not exporting) variable
1794 flg_export == 1 if "new" exporting environ
1795 flg_export > 1 if current startup environ (not call putenv()) */
1796 static int set_local_var(const char *s, int flg_export)
1800 struct variables *cur;
1804 /* Assume when we enter this function that we are already in
1805 * NAME=VALUE format. So the first order of business is to
1806 * split 's' on the '=' into 'name' and 'value' */
1807 value = strchr(name, '=');
1808 if (value == 0 && ++value == 0) {
1814 for (cur = top_vars; cur; cur = cur->next) {
1815 if (strcmp(cur->name, name) == 0)
1820 if (strcmp(cur->value, value) == 0) {
1821 if (flg_export > 0 && cur->flg_export == 0)
1822 cur->flg_export = flg_export;
1826 if (cur->flg_read_only) {
1827 bb_error_msg("%s: readonly variable", name);
1830 if (flg_export > 0 || cur->flg_export > 1)
1831 cur->flg_export = 1;
1832 free((char*)cur->value);
1834 cur->value = strdup(value);
1838 cur = malloc(sizeof(struct variables));
1842 cur->name = strdup(name);
1847 struct variables *bottom = top_vars;
1848 cur->value = strdup(value);
1850 cur->flg_export = flg_export;
1851 cur->flg_read_only = 0;
1852 while (bottom->next)
1853 bottom = bottom->next;
1859 if (result == 0 && cur->flg_export == 1) {
1861 result = putenv(name);
1864 if (result > 0) /* equivalent to previous set */
1870 static void unset_local_var(const char *name)
1872 struct variables *cur;
1875 for (cur = top_vars; cur; cur = cur->next) {
1876 if (strcmp(cur->name, name) == 0)
1880 struct variables *next = top_vars;
1881 if (cur->flg_read_only) {
1882 bb_error_msg("%s: readonly variable", name);
1885 if (cur->flg_export)
1886 unsetenv(cur->name);
1887 free((char*)cur->name);
1888 free((char*)cur->value);
1889 while (next->next != cur)
1891 next->next = cur->next;
1897 static int is_assignment(const char *s)
1899 if (!s || !isalpha(*s))
1902 while (isalnum(*s) || *s == '_')
1907 /* the src parameter allows us to peek forward to a possible &n syntax
1908 * for file descriptor duplication, e.g., "2>&1".
1909 * Return code is 0 normally, 1 if a syntax error is detected in src.
1910 * Resource errors (in xmalloc) cause the process to exit */
1911 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1912 struct in_str *input)
1914 struct child_prog *child = ctx->child;
1915 struct redir_struct *redir = child->redirects;
1916 struct redir_struct *last_redir = NULL;
1918 /* Create a new redir_struct and drop it onto the end of the linked list */
1921 redir = redir->next;
1923 redir = xmalloc(sizeof(struct redir_struct));
1925 redir->word.gl_pathv = NULL;
1927 last_redir->next = redir;
1929 child->redirects = redir;
1932 redir->type = style;
1933 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
1935 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1937 /* Check for a '2>&1' type redirect */
1938 redir->dup = redirect_dup_num(input);
1939 if (redir->dup == -2) return 1; /* syntax error */
1940 if (redir->dup != -1) {
1941 /* Erik had a check here that the file descriptor in question
1942 * is legit; I postpone that to "run time"
1943 * A "-" representation of "close me" shows up as a -3 here */
1944 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
1946 /* We do _not_ try to open the file that src points to,
1947 * since we need to return and let src be expanded first.
1948 * Set ctx->pending_redirect, so we know what to do at the
1949 * end of the next parsed word.
1951 ctx->pending_redirect = redir;
1956 static struct pipe *new_pipe(void) {
1958 pi = xmalloc(sizeof(struct pipe));
1962 pi->followup = 0; /* invalid */
1963 pi->r_mode = RES_NONE;
1967 static void initialize_context(struct p_context *ctx)
1970 ctx->pending_redirect = NULL;
1972 ctx->list_head = new_pipe();
1973 ctx->pipe = ctx->list_head;
1977 done_command(ctx); /* creates the memory for working child */
1980 /* normal return is 0
1981 * if a reserved word is found, and processed, return 1
1982 * should handle if, then, elif, else, fi, for, while, until, do, done.
1983 * case, function, and select are obnoxious, save those for later.
1985 static int reserved_word(o_string *dest, struct p_context *ctx)
1987 struct reserved_combo {
1988 const char *literal;
1992 /* Mostly a list of accepted follow-up reserved words.
1993 * FLAG_END means we are done with the sequence, and are ready
1994 * to turn the compound list into a command.
1995 * FLAG_START means the word must start a new compound list.
1997 static const struct reserved_combo reserved_list[] = {
1998 { "if", RES_IF, FLAG_THEN | FLAG_START },
1999 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2000 { "elif", RES_ELIF, FLAG_THEN },
2001 { "else", RES_ELSE, FLAG_FI },
2002 { "fi", RES_FI, FLAG_END },
2003 { "for", RES_FOR, FLAG_IN | FLAG_START },
2004 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2005 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2006 { "in", RES_IN, FLAG_DO },
2007 { "do", RES_DO, FLAG_DONE },
2008 { "done", RES_DONE, FLAG_END }
2010 const struct reserved_combo *r;
2011 #define NRES sizeof(reserved_list)/sizeof(reserved_list[0])
2013 for (r = reserved_list; r < reserved_list+NRES; r++) {
2014 if (strcmp(dest->data, r->literal) == 0) {
2015 debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2016 if (r->flag & FLAG_START) {
2017 struct p_context *new = xmalloc(sizeof(struct p_context));
2018 debug_printf("push stack\n");
2019 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2026 *new = *ctx; /* physical copy */
2027 initialize_context(ctx);
2029 } else if (ctx->w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
2036 ctx->old_flag = r->flag;
2037 if (ctx->old_flag & FLAG_END) {
2038 struct p_context *old;
2039 debug_printf("pop stack\n");
2040 done_pipe(ctx,PIPE_SEQ);
2042 old->child->group = ctx->list_head;
2043 old->child->subshell = 0;
2044 *ctx = *old; /* physical copy */
2054 /* normal return is 0.
2055 * Syntax or xglob errors return 1. */
2056 static int done_word(o_string *dest, struct p_context *ctx)
2058 struct child_prog *child = ctx->child;
2059 glob_t *glob_target;
2062 debug_printf("done_word: %s %p\n", dest->data, child);
2063 if (dest->length == 0 && !dest->nonnull) {
2064 debug_printf(" true null, ignored\n");
2067 if (ctx->pending_redirect) {
2068 glob_target = &ctx->pending_redirect->word;
2072 return 1; /* syntax error, groups and arglists don't mix */
2074 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2075 debug_printf("checking %s for reserved-ness\n",dest->data);
2076 if (reserved_word(dest,ctx))
2077 return (ctx->w == RES_SNTX);
2079 glob_target = &child->glob_result;
2080 if (child->argv) flags |= GLOB_APPEND;
2082 gr = xglob(dest, flags, glob_target);
2083 if (gr != 0) return 1;
2086 if (ctx->pending_redirect) {
2087 ctx->pending_redirect = NULL;
2088 if (glob_target->gl_pathc != 1) {
2089 bb_error_msg("ambiguous redirect");
2093 child->argv = glob_target->gl_pathv;
2095 if (ctx->w == RES_FOR) {
2096 done_word(dest,ctx);
2097 done_pipe(ctx,PIPE_SEQ);
2102 /* The only possible error here is out of memory, in which case
2104 static int done_command(struct p_context *ctx)
2106 /* The child is really already in the pipe structure, so
2107 * advance the pipe counter and make a new, null child.
2108 * Only real trickiness here is that the uncommitted
2109 * child structure, to which ctx->child points, is not
2110 * counted in pi->num_progs. */
2111 struct pipe *pi = ctx->pipe;
2112 struct child_prog *prog = ctx->child;
2114 if (prog && prog->group == NULL
2115 && prog->argv == NULL
2116 && prog->redirects == NULL) {
2117 debug_printf("done_command: skipping null command\n");
2121 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2123 debug_printf("done_command: initializing\n");
2125 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2127 prog = pi->progs + pi->num_progs;
2128 prog->redirects = NULL;
2130 prog->is_stopped = 0;
2132 prog->glob_result.gl_pathv = NULL;
2136 prog->type = ctx->type;
2138 /* but ctx->pipe and ctx->list_head remain unchanged */
2142 static int done_pipe(struct p_context *ctx, pipe_style type)
2145 done_command(ctx); /* implicit closure of previous command */
2146 debug_printf("done_pipe, type %d\n", type);
2147 ctx->pipe->followup = type;
2148 ctx->pipe->r_mode = ctx->w;
2150 ctx->pipe->next = new_p;
2153 done_command(ctx); /* set up new pipe to accept commands */
2157 /* peek ahead in the in_str to find out if we have a "&n" construct,
2158 * as in "2>&1", that represents duplicating a file descriptor.
2159 * returns either -2 (syntax error), -1 (no &), or the number found.
2161 static int redirect_dup_num(struct in_str *input)
2163 int ch, d = 0, ok = 0;
2165 if (ch != '&') return -1;
2167 b_getch(input); /* get the & */
2171 return -3; /* "-" represents "close me" */
2173 while (isdigit(ch)) {
2181 bb_error_msg("ambiguous redirect");
2185 /* If a redirect is immediately preceded by a number, that number is
2186 * supposed to tell which file descriptor to redirect. This routine
2187 * looks for such preceding numbers. In an ideal world this routine
2188 * needs to handle all the following classes of redirects...
2189 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2190 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2191 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2192 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2193 * A -1 output from this program means no valid number was found, so the
2194 * caller should use the appropriate default for this redirection.
2196 static int redirect_opt_num(o_string *o)
2202 for (num = 0; num < o->length; num++) {
2203 if (!isdigit(*(o->data + num))) {
2207 /* reuse num (and save an int) */
2208 num = atoi(o->data);
2213 static FILE *generate_stream_from_list(struct pipe *head)
2216 int pid, channel[2];
2217 if (pipe(channel) < 0) bb_perror_msg_and_die("pipe");
2218 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
2224 bb_perror_msg_and_die("fork");
2225 } else if (pid == 0) {
2227 if (channel[1] != 1) {
2231 _exit(run_list_real(head)); /* leaks memory */
2233 debug_printf("forked child %d\n",pid);
2235 pf = fdopen(channel[0],"r");
2236 debug_printf("pipe on FILE *%p\n",pf);
2240 /* this version hacked for testing purposes */
2241 /* return code is exit status of the process that is run. */
2242 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2245 o_string result = NULL_O_STRING;
2246 struct p_context inner;
2248 struct in_str pipe_str;
2249 initialize_context(&inner);
2251 /* recursion to generate command */
2252 retcode = parse_stream(&result, &inner, input, subst_end);
2253 if (retcode != 0) return retcode; /* syntax error or EOF */
2254 done_word(&result, &inner);
2255 done_pipe(&inner, PIPE_SEQ);
2258 p = generate_stream_from_list(inner.list_head);
2259 if (p == NULL) return 1;
2260 mark_open(fileno(p));
2261 setup_file_in_str(&pipe_str, p);
2263 /* now send results of command back into original context */
2264 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2265 /* XXX In case of a syntax error, should we try to kill the child?
2266 * That would be tough to do right, so just read until EOF. */
2268 while (b_getch(&pipe_str) != EOF)
2272 debug_printf("done reading from pipe, pclose()ing\n");
2273 /* This is the step that wait()s for the child. Should be pretty
2274 * safe, since we just read an EOF from its stdout. We could try
2275 * to better, by using wait(), and keeping track of background jobs
2276 * at the same time. That would be a lot of work, and contrary
2277 * to the KISS philosophy of this program. */
2278 mark_closed(fileno(p));
2279 retcode = pclose(p);
2280 free_pipe_list(inner.list_head,0);
2281 debug_printf("pclosed, retcode=%d\n",retcode);
2282 /* XXX this process fails to trim a single trailing newline */
2286 static int parse_group(o_string *dest, struct p_context *ctx,
2287 struct in_str *input, int ch)
2289 int rcode, endch = 0;
2290 struct p_context sub;
2291 struct child_prog *child = ctx->child;
2294 return 1; /* syntax error, groups and arglists don't mix */
2296 initialize_context(&sub);
2300 child->subshell = 1;
2306 syntax(); /* really logic error */
2308 rcode = parse_stream(dest,&sub,input,endch);
2309 done_word(dest,&sub); /* finish off the final word in the subcontext */
2310 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2311 child->group = sub.list_head;
2313 /* child remains "open", available for possible redirects */
2316 /* basically useful version until someone wants to get fancier,
2317 * see the bash man page under "Parameter Expansion" */
2318 static const char *lookup_param(const char *src)
2320 const char *p = NULL;
2324 p = get_local_var(src);
2329 /* return code: 0 for OK, 1 for syntax error */
2330 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2334 int ch = input->peek(input); /* first character after the $ */
2335 debug_printf("handle_dollar: ch=%c\n",ch);
2337 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2339 while (ch = b_peek(input),isalnum(ch) || ch == '_') {
2343 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2344 } else if (isdigit(ch)) {
2345 i = ch-'0'; /* XXX is $0 special? */
2346 if (i < global_argc) {
2347 parse_string(dest, ctx, global_argv[i]); /* recursion */
2350 } else switch (ch) {
2352 b_adduint(dest,getpid());
2356 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2360 b_adduint(dest,last_return_code);
2364 b_adduint(dest,global_argc ? global_argc-1 : 0);
2368 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2371 /* XXX maybe someone will try to escape the '}' */
2373 ch = b_getch(input);
2374 if (ch == EOF || ch == '}')
2382 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2386 process_command_subs(dest, ctx, input, ')');
2390 for (i = 1; i < global_argc; i++) {
2391 parse_string(dest, ctx, global_argv[i]);
2392 if (i+1 < global_argc)
2393 parse_string(dest, ctx, sep);
2399 /* still unhandled, but should be eventually */
2400 bb_error_msg("unhandled syntax: $%c",ch);
2404 b_addqchr(dest,'$',dest->quote);
2406 /* Eat the character if the flag was set. If the compiler
2407 * is smart enough, we could substitute "b_getch(input);"
2408 * for all the "advance = 1;" above, and also end up with
2409 * a nice size-optimized program. Hah! That'll be the day.
2411 if (advance) b_getch(input);
2415 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2418 setup_string_in_str(&foo, src);
2419 return parse_stream(dest, ctx, &foo, '\0');
2422 /* return code is 0 for normal exit, 1 for syntax error */
2423 int parse_stream(o_string *dest, struct p_context *ctx,
2424 struct in_str *input, int end_trigger)
2428 redir_type redir_style;
2431 /* Only double-quote state is handled in the state variable dest->quote.
2432 * A single-quote triggers a bypass of the main loop until its mate is
2433 * found. When recursing, quote state is passed in via dest->quote. */
2435 debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2436 while ((ch = b_getch(input)) != EOF) {
2438 next = (ch == '\n') ? 0 : b_peek(input);
2439 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2440 ch, ch, m, dest->quote);
2441 if (m == 0 || ((m == 1 || m == 2) && dest->quote)) {
2442 b_addqchr(dest, ch, dest->quote);
2445 if (m == 2) { /* unquoted IFS */
2446 if (done_word(dest, ctx)) {
2449 /* If we aren't performing a substitution, treat a newline as a
2450 * command separator. */
2451 if (end_trigger != '\0' && ch == '\n')
2452 done_pipe(ctx,PIPE_SEQ);
2454 if (ch == end_trigger && !dest->quote && ctx->w == RES_NONE) {
2455 debug_printf("leaving parse_stream (triggered)\n");
2462 if (dest->length == 0 && !dest->quote) {
2465 if (ch == EOF || ch == '\n')
2470 b_addqchr(dest, ch, dest->quote);
2478 b_addqchr(dest, '\\', dest->quote);
2479 b_addqchr(dest, b_getch(input), dest->quote);
2482 if (handle_dollar(dest, ctx, input) != 0) return 1;
2487 ch = b_getch(input);
2488 if (ch == EOF || ch == '\'')
2499 dest->quote = !dest->quote;
2502 process_command_subs(dest, ctx, input, '`');
2505 redir_fd = redirect_opt_num(dest);
2506 done_word(dest, ctx);
2507 redir_style = REDIRECT_OVERWRITE;
2509 redir_style = REDIRECT_APPEND;
2511 } else if (next == '(') {
2512 syntax(); /* until we support >(list) Process Substitution */
2515 setup_redirect(ctx, redir_fd, redir_style, input);
2518 redir_fd = redirect_opt_num(dest);
2519 done_word(dest, ctx);
2520 redir_style = REDIRECT_INPUT;
2522 redir_style = REDIRECT_HEREIS;
2524 } else if (next == '>') {
2525 redir_style = REDIRECT_IO;
2527 } else if (next == '(') {
2528 syntax(); /* until we support <(list) Process Substitution */
2531 setup_redirect(ctx, redir_fd, redir_style, input);
2534 done_word(dest, ctx);
2535 done_pipe(ctx,PIPE_SEQ);
2538 done_word(dest, ctx);
2541 done_pipe(ctx,PIPE_AND);
2543 done_pipe(ctx,PIPE_BG);
2547 done_word(dest, ctx);
2550 done_pipe(ctx,PIPE_OR);
2552 /* we could pick up a file descriptor choice here
2553 * with redirect_opt_num(), but bash doesn't do it.
2554 * "echo foo 2| cat" yields "foo 2". */
2560 if (parse_group(dest, ctx, input, ch) != 0)
2565 syntax(); /* Proper use of this character caught by end_trigger */
2568 syntax(); /* this is really an internal logic error */
2572 /* complain if quote? No, maybe we just finished a command substitution
2573 * that was quoted. Example:
2574 * $ echo "`cat foo` plus more"
2575 * and we just got the EOF generated by the subshell that ran "cat foo"
2576 * The only real complaint is if we got an EOF when end_trigger != '\0',
2577 * that is, we were really supposed to get end_trigger, and never got
2578 * one before the EOF. Can't use the standard "syntax error" return code,
2579 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
2580 debug_printf("leaving parse_stream (EOF)\n");
2581 if (end_trigger != '\0') return -1;
2585 static void mapset(const char *set, int code)
2587 const unsigned char *s;
2588 for (s = (const unsigned char *)set; *s; s++) map[(int)*s] = code;
2591 static void update_ifs_map(void)
2593 /* char *ifs and char map[256] are both globals. */
2594 ifs = getenv("IFS");
2595 if (ifs == NULL) ifs = " \t\n";
2596 /* Precompute a list of 'flow through' behavior so it can be treated
2597 * quickly up front. Computation is necessary because of IFS.
2598 * Special case handling of IFS == " \t\n" is not implemented.
2599 * The map[] array only really needs two bits each, and on most machines
2600 * that would be faster because of the reduced L1 cache footprint.
2602 memset(map, 0, sizeof(map)); /* most characters flow through always */
2603 mapset("\\$'\"`", 3); /* never flow through */
2604 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2605 mapset(ifs, 2); /* also flow through if quoted */
2608 /* most recursion does not come through here, the exception is
2609 * from builtin_source() */
2610 int parse_stream_outer(struct in_str *inp, int flag)
2613 struct p_context ctx;
2614 o_string temp = NULL_O_STRING;
2618 initialize_context(&ctx);
2620 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
2621 inp->promptmode = 1;
2622 rcode = parse_stream(&temp, &ctx, inp, '\n');
2623 if (rcode != 1 && ctx.old_flag != 0) {
2626 if (rcode != 1 && ctx.old_flag == 0) {
2627 done_word(&temp, &ctx);
2628 done_pipe(&ctx,PIPE_SEQ);
2629 run_list(ctx.list_head);
2631 if (ctx.old_flag != 0) {
2638 free_pipe_list(ctx.list_head,0);
2641 } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
2645 static int parse_string_outer(const char *s, int flag)
2647 struct in_str input;
2648 setup_string_in_str(&input, s);
2649 return parse_stream_outer(&input, flag);
2652 static int parse_file_outer(FILE *f)
2655 struct in_str input;
2656 setup_file_in_str(&input, f);
2657 rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
2661 /* Make sure we have a controlling tty. If we get started under a job
2662 * aware app (like bash for example), make sure we are now in charge so
2663 * we don't fight over who gets the foreground */
2664 static void setup_job_control(void)
2666 static pid_t shell_pgrp;
2667 /* Loop until we are in the foreground. */
2668 while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
2669 kill (- shell_pgrp, SIGTTIN);
2671 /* Ignore interactive and job-control signals. */
2672 signal(SIGINT, SIG_IGN);
2673 signal(SIGQUIT, SIG_IGN);
2674 signal(SIGTERM, SIG_IGN);
2675 signal(SIGTSTP, SIG_IGN);
2676 signal(SIGTTIN, SIG_IGN);
2677 signal(SIGTTOU, SIG_IGN);
2678 signal(SIGCHLD, SIG_IGN);
2680 /* Put ourselves in our own process group. */
2682 shell_pgrp = getpid();
2683 setpgid(shell_pgrp, shell_pgrp);
2685 /* Grab control of the terminal. */
2686 tcsetpgrp(shell_terminal, shell_pgrp);
2689 int hush_main(int argc, char **argv);
2690 int hush_main(int argc, char **argv)
2696 #if ENABLE_FEATURE_EDITING
2697 line_input_state = new_line_input_t(FOR_SHELL);
2700 /* XXX what should these be while sourcing /etc/profile? */
2704 /* (re?) initialize globals. Sometimes hush_main() ends up calling
2705 * hush_main(), therefore we cannot rely on the BSS to zero out this
2706 * stuff. Reset these to 0 every time. */
2708 /* map[] is taken care of with call to update_ifs_map() */
2711 close_me_head = NULL;
2716 /* Initialize some more globals to non-zero values */
2718 if (ENABLE_FEATURE_EDITING)
2719 cmdedit_set_initial_prompt();
2723 /* initialize our shell local variables with the values
2724 * currently living in the environment */
2727 set_local_var(*e, 2); /* without call putenv() */
2730 last_return_code = EXIT_SUCCESS;
2732 if (argv[0] && argv[0][0] == '-') {
2733 debug_printf("\nsourcing /etc/profile\n");
2734 if ((input = fopen("/etc/profile", "r")) != NULL) {
2735 mark_open(fileno(input));
2736 parse_file_outer(input);
2737 mark_closed(fileno(input));
2743 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2747 global_argv = argv+optind;
2748 global_argc = argc-optind;
2749 opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
2761 fprintf(stderr, "Usage: sh [FILE]...\n"
2762 " or: sh -c command [args]...\n\n");
2769 /* A shell is interactive if the `-i' flag was given, or if all of
2770 * the following conditions are met:
2772 * no arguments remaining or the -s flag given
2773 * standard input is a terminal
2774 * standard output is a terminal
2775 * Refer to Posix.2, the description of the `sh' utility. */
2776 if (argv[optind] == NULL && input == stdin
2777 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
2782 debug_printf("\ninteractive=%d\n", interactive);
2784 /* Looks like they want an interactive shell */
2785 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
2786 printf( "\n\n%s hush - the humble shell v0.01 (testing)\n",
2788 printf( "Enter 'help' for a list of built-in commands.\n\n");
2790 setup_job_control();
2793 if (argv[optind] == NULL) {
2794 opt = parse_file_outer(stdin);
2798 debug_printf("\nrunning script '%s'\n", argv[optind]);
2799 global_argv = argv + optind;
2800 global_argc = argc - optind;
2801 input = xfopen(argv[optind], "r");
2802 opt = parse_file_outer(input);
2804 #if ENABLE_FEATURE_CLEAN_UP
2806 if (cwd && cwd != bb_msg_unknown)
2809 struct variables *cur, *tmp;
2810 for (cur = top_vars; cur; cur = tmp) {
2812 if (!cur->flg_read_only) {
2813 free((char*)cur->name);
2814 free((char*)cur->value);
2822 return opt ? opt : last_return_code;
2825 static char *insert_var_value(char *inp)
2827 int res_str_len = 0;
2830 char *p, *res_str = NULL;
2833 while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
2836 res_str = xrealloc(res_str, (res_str_len + len));
2837 strncpy((res_str + res_str_len), inp, len);
2841 p = strchr(inp, SPECIAL_VAR_SYMBOL);
2843 p1 = lookup_param(inp);
2845 len = res_str_len + strlen(p1);
2846 res_str = xrealloc(res_str, (1 + len));
2847 strcpy((res_str + res_str_len), p1);
2850 *p = SPECIAL_VAR_SYMBOL;
2855 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
2856 strcpy((res_str + res_str_len), inp);
2857 while ((p = strchr(res_str, '\n'))) {
2861 return (res_str == NULL) ? inp : res_str;
2864 static char **make_list_in(char **inp, char *name)
2867 int name_len = strlen(name);
2872 /* create list of variable values */
2873 list = xmalloc(sizeof(*list));
2874 for (i = 0; inp[i]; i++) {
2875 p3 = insert_var_value(inp[i]);
2882 if ((p2 = strchr(p1, ' '))) {
2888 /* we use n + 2 in realloc for list,because we add
2889 * new element and then we will add NULL element */
2890 list = xrealloc(list, sizeof(*list) * (n + 2));
2891 list[n] = xmalloc(2 + name_len + len);
2892 strcpy(list[n], name);
2893 strcat(list[n], "=");
2894 strncat(list[n], p1, len);
2895 list[n++][name_len + len + 1] = '\0';
2898 if (p3 != inp[i]) free(p3);
2904 /* Make new string for parser */
2905 static char* make_string(char ** inp)
2912 for (n = 0; inp[n]; n++) {
2913 p = insert_var_value(inp[n]);
2914 str = xrealloc(str, (len + strlen(p)));
2921 len = strlen(str) + 3;
2922 if (p != inp[n]) free(p);
2925 *(str + len) = '\n';
2926 *(str + len + 1) = '\0';