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 * b_addchr() derived from similar w_addchar function in glibc-2.2
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen
26 * miscellaneous bugfixes from Matt Kraai
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * Bash grammar not implemented: (how many of these were in original sh?)
40 * $@ (those sure look like weird quoting rules)
42 * ! negation operator for pipes
43 * &> and >& redirection of stdout+stderr
46 * fancy forms of Parameter Expansion
48 * Arithmetic Expansion
49 * <(list) and >(list) Process Substitution
50 * reserved words: case, esac, select, function
51 * Here Documents ( << word )
54 * job handling woefully incomplete and buggy
55 * reserved word execution woefully incomplete and buggy
57 * port selected bugfixes from post-0.49 busybox lash - done?
58 * finish implementing reserved words: for, while, until, do, done
59 * change { and } from special chars to reserved words
60 * builtins: break, continue, eval, return, set, trap, ulimit
62 * handle children going into background
63 * clean up recognition of null pipes
64 * check setting of global_argc and global_argv
65 * control-C handling, probably with longjmp
66 * follow IFS rules more precisely, including update semantics
67 * figure out what to do with backslash-newline
68 * explain why we use signal instead of sigaction
69 * propagate syntax errors, die on resource errors?
70 * continuation lines, both explicit and implicit - done?
71 * memory leak finding and plugging - done?
72 * more testing, especially quoting rules and redirection
73 * document how quoting rules not precisely followed for variable assignments
74 * maybe change map[] to use 2-bit entries
75 * (eventually) remove all the printf's
77 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
81 #include <glob.h> /* glob, of course */
82 #include <getopt.h> /* should be pretty obvious */
84 //#include <sys/wait.h>
87 /* #include <dmalloc.h> */
88 /* #define DEBUG_SHELL */
91 #define SPECIAL_VAR_SYMBOL 03
92 #define FLAG_EXIT_FROM_LOOP 1
93 #define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
94 #define FLAG_REPARSING (1 << 2) /* >=2nd pass */
98 REDIRECT_OVERWRITE = 2,
104 /* The descrip member of this structure is only used to make debugging
106 static const struct {
112 { O_RDONLY, 0, "<" },
113 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
114 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
115 { O_RDONLY, -1, "<<" },
126 /* might eventually control execution */
144 FLAG_END = (1 << RES_NONE ),
145 FLAG_IF = (1 << RES_IF ),
146 FLAG_THEN = (1 << RES_THEN ),
147 FLAG_ELIF = (1 << RES_ELIF ),
148 FLAG_ELSE = (1 << RES_ELSE ),
149 FLAG_FI = (1 << RES_FI ),
150 FLAG_FOR = (1 << RES_FOR ),
151 FLAG_WHILE = (1 << RES_WHILE),
152 FLAG_UNTIL = (1 << RES_UNTIL),
153 FLAG_DO = (1 << RES_DO ),
154 FLAG_DONE = (1 << RES_DONE ),
155 FLAG_IN = (1 << RES_IN ),
156 FLAG_START = (1 << RES_XXXX ),
159 /* This holds pointers to the various results of parsing */
161 struct child_prog *child;
162 struct pipe *list_head;
164 struct redir_struct *pending_redirect;
166 int old_flag; /* for figuring out valid reserved words */
167 struct p_context *stack;
168 int type; /* define type of parser : ";$" common or special symbol */
169 /* How about quoting status? */
172 struct redir_struct {
173 redir_type type; /* type of redirection */
174 int fd; /* file descriptor being redirected */
175 int dup; /* -1, or file descriptor being duplicated */
176 struct redir_struct *next; /* pointer to the next redirect in the list */
177 glob_t word; /* *word.gl_pathv is the filename */
181 pid_t pid; /* 0 if exited */
182 char **argv; /* program name and arguments */
183 struct pipe *group; /* if non-NULL, first in group or subshell */
184 int subshell; /* flag, non-zero if group must be forked */
185 struct redir_struct *redirects; /* I/O redirections */
186 glob_t glob_result; /* result of parameter globbing */
187 int is_stopped; /* is the program currently running? */
188 struct pipe *family; /* pointer back to the child's parent pipe */
189 int sp; /* number of SPECIAL_VAR_SYMBOL */
194 int jobid; /* job number */
195 int num_progs; /* total number of programs in job */
196 int running_progs; /* number of programs running */
197 char *text; /* name of job */
198 char *cmdbuf; /* buffer various argv's point into */
199 pid_t pgrp; /* process group ID for the job */
200 struct child_prog *progs; /* array of commands in pipe */
201 struct pipe *next; /* to track background commands */
202 int stopped_progs; /* number of programs alive, but stopped */
203 int job_context; /* bitmask defining current context */
204 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
205 reserved_style r_mode; /* supports if, for, while, until */
210 struct close_me *next;
218 struct variables *next;
221 /* globals, connect us to the outside world
222 * the first three support $?, $#, and $1 */
223 static char **global_argv;
224 static int global_argc;
225 static int last_return_code;
226 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
228 /* "globals" within this file */
229 static const char *ifs;
230 static unsigned char map[256];
231 static int fake_mode;
232 static int interactive;
233 static struct close_me *close_me_head;
234 static const char *cwd;
235 static struct pipe *job_list;
236 static unsigned last_bg_pid;
237 static int last_jobid;
238 static unsigned shell_terminal;
239 static const char *PS1;
240 static const char *PS2;
241 static struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
242 static struct variables *top_vars = &shell_ver;
245 #define B_CHUNK (100)
255 #define NULL_O_STRING {NULL,0,0,0,0}
256 /* used for initialization:
257 o_string foo = NULL_O_STRING; */
259 /* I can almost use ordinary FILE *. Is open_memstream() universally
260 * available? Where is it documented? */
267 int (*get) (struct in_str *);
268 int (*peek) (struct in_str *);
270 #define b_getch(input) ((input)->get(input))
271 #define b_peek(input) ((input)->peek(input))
273 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
275 struct built_in_command {
276 const char *cmd; /* name */
277 const char *descr; /* description */
278 int (*function) (struct child_prog *); /* function ptr */
281 /* belongs in busybox.h */
282 static int max(int a, int b)
284 return (a > b) ? a : b;
287 /* This should be in utility.c */
289 static void debug_printf(const char *format, ...)
292 va_start(args, format);
293 vfprintf(stderr, format, args);
296 /* broken, of course, but OK for testing */
297 static char *indenter(int i)
299 static char blanks[] = " ";
300 return &blanks[sizeof(blanks)-i-1];
303 #define debug_printf(...) do {} while (0)
305 #define final_printf debug_printf
307 static void __syntax(const char *file, int line)
309 bb_error_msg("syntax error %s:%d", file, line);
311 // NB: was __FILE__, but that produces full path sometimes, so...
312 #define syntax() __syntax("hush.c", __LINE__)
314 /* Index of subroutines: */
315 /* function prototypes for builtins */
316 static int builtin_cd(struct child_prog *child);
317 static int builtin_env(struct child_prog *child);
318 static int builtin_eval(struct child_prog *child);
319 static int builtin_exec(struct child_prog *child);
320 static int builtin_exit(struct child_prog *child);
321 static int builtin_export(struct child_prog *child);
322 static int builtin_fg_bg(struct child_prog *child);
323 static int builtin_help(struct child_prog *child);
324 static int builtin_jobs(struct child_prog *child);
325 static int builtin_pwd(struct child_prog *child);
326 static int builtin_read(struct child_prog *child);
327 static int builtin_set(struct child_prog *child);
328 static int builtin_shift(struct child_prog *child);
329 static int builtin_source(struct child_prog *child);
330 static int builtin_umask(struct child_prog *child);
331 static int builtin_unset(struct child_prog *child);
332 static int builtin_not_written(struct child_prog *child);
333 /* o_string manipulation: */
334 static int b_check_space(o_string *o, int len);
335 static int b_addchr(o_string *o, int ch);
336 static void b_reset(o_string *o);
337 static int b_addqchr(o_string *o, int ch, int quote);
338 static int b_adduint(o_string *o, unsigned i);
339 /* in_str manipulations: */
340 static int static_get(struct in_str *i);
341 static int static_peek(struct in_str *i);
342 static int file_get(struct in_str *i);
343 static int file_peek(struct in_str *i);
344 static void setup_file_in_str(struct in_str *i, FILE *f);
345 static void setup_string_in_str(struct in_str *i, const char *s);
346 /* close_me manipulations: */
347 static void mark_open(int fd);
348 static void mark_closed(int fd);
349 static void close_all(void);
350 /* "run" the final data structures: */
351 static int free_pipe_list(struct pipe *head, int indent);
352 static int free_pipe(struct pipe *pi, int indent);
353 /* really run the final data structures: */
354 static int setup_redirects(struct child_prog *prog, int squirrel[]);
355 static int run_list_real(struct pipe *pi);
356 static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
357 static int run_pipe_real(struct pipe *pi);
358 /* extended glob support: */
359 static int globhack(const char *src, int flags, glob_t *pglob);
360 static int glob_needed(const char *s);
361 static int xglob(o_string *dest, int flags, glob_t *pglob);
362 /* variable assignment: */
363 static int is_assignment(const char *s);
364 /* data structure manipulation: */
365 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
366 static void initialize_context(struct p_context *ctx);
367 static int done_word(o_string *dest, struct p_context *ctx);
368 static int done_command(struct p_context *ctx);
369 static int done_pipe(struct p_context *ctx, pipe_style type);
370 /* primary string parsing: */
371 static int redirect_dup_num(struct in_str *input);
372 static int redirect_opt_num(o_string *o);
373 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
374 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
375 static const char *lookup_param(const char *src);
376 static char *make_string(char **inp);
377 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
378 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
379 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
381 static int parse_stream_outer(struct in_str *inp, int flag);
382 static int parse_string_outer(const char *s, int flag);
383 static int parse_file_outer(FILE *f);
384 /* job management: */
385 static int checkjobs(struct pipe* fg_pipe);
386 static void insert_bg_job(struct pipe *pi);
387 static void remove_bg_job(struct pipe *pi);
388 /* local variable support */
389 static char **make_list_in(char **inp, char *name);
390 static char *insert_var_value(char *inp);
391 static const char *get_local_var(const char *var);
392 static void unset_local_var(const char *name);
393 static int set_local_var(const char *s, int flg_export);
395 /* Table of built-in functions. They can be forked or not, depending on
396 * context: within pipes, they fork. As simple commands, they do not.
397 * When used in non-forking context, they can change global variables
398 * in the parent shell process. If forked, of course they cannot.
399 * For example, 'unset foo | whatever' will parse and run, but foo will
400 * still be set at the end. */
401 static const struct built_in_command bltins[] = {
402 { "bg", "Resume a job in the background", builtin_fg_bg },
403 { "break", "Exit for, while or until loop", builtin_not_written },
404 { "cd", "Change working directory", builtin_cd },
405 { "continue", "Continue for, while or until loop", builtin_not_written },
406 { "env", "Print all environment variables", builtin_env },
407 { "eval", "Construct and run shell command", builtin_eval },
408 { "exec", "Exec command, replacing this shell with the exec'd process",
410 { "exit", "Exit from shell()", builtin_exit },
411 { "export", "Set environment variable", builtin_export },
412 { "fg", "Bring job into the foreground", builtin_fg_bg },
413 { "jobs", "Lists the active jobs", builtin_jobs },
414 { "pwd", "Print current directory", builtin_pwd },
415 { "read", "Input environment variable", builtin_read },
416 { "return", "Return from a function", builtin_not_written },
417 { "set", "Set/unset shell local variables", builtin_set },
418 { "shift", "Shift positional parameters", builtin_shift },
419 { "trap", "Trap signals", builtin_not_written },
420 { "ulimit","Controls resource limits", builtin_not_written },
421 { "umask","Sets file creation mask", builtin_umask },
422 { "unset", "Unset environment variable", builtin_unset },
423 { ".", "Source-in and run commands in a file", builtin_source },
424 { "help", "List shell built-in commands", builtin_help },
428 static const char *set_cwd(void)
430 if (cwd == bb_msg_unknown)
431 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
432 cwd = xrealloc_getcwd_or_warn((char *)cwd);
434 cwd = bb_msg_unknown;
438 /* built-in 'eval' handler */
439 static int builtin_eval(struct child_prog *child)
442 int rcode = EXIT_SUCCESS;
444 if (child->argv[1]) {
445 str = make_string(child->argv + 1);
446 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
447 FLAG_PARSE_SEMICOLON);
449 rcode = last_return_code;
454 /* built-in 'cd <path>' handler */
455 static int builtin_cd(struct child_prog *child)
458 if (child->argv[1] == NULL)
459 newdir = getenv("HOME");
461 newdir = child->argv[1];
463 printf("cd: %s: %s\n", newdir, strerror(errno));
470 /* built-in 'env' handler */
471 static int builtin_env(struct child_prog *dummy ATTRIBUTE_UNUSED)
473 /* TODO: call env applet's code instead */
483 /* built-in 'exec' handler */
484 static int builtin_exec(struct child_prog *child)
486 if (child->argv[1] == NULL)
487 return EXIT_SUCCESS; /* Really? */
493 /* built-in 'exit' handler */
494 static int builtin_exit(struct child_prog *child)
496 /* bash prints "exit\n" here, then: */
497 if (child->argv[1] == NULL)
498 exit(last_return_code);
499 /* mimic bash: exit 123abc == exit 255 + error msg */
500 xfunc_error_retval = 255;
501 /* bash: exit -2 == exit 254, no error msg */
502 exit(xatoi(child->argv[1]));
505 /* built-in 'export VAR=value' handler */
506 static int builtin_export(struct child_prog *child)
509 char *name = child->argv[1];
512 return builtin_env(child);
518 const char *value = strchr(name, '=');
522 /* They are exporting something without an =VALUE */
524 value = get_local_var(name);
526 size_t ln = strlen(name);
528 tmp = realloc(name, ln+strlen(value)+2);
532 sprintf(tmp+ln, "=%s", value);
536 /* bash does not return an error when trying to export
537 * an undefined variable. Do likewise. */
543 bb_perror_msg("export");
545 res = set_local_var(name, 1);
552 /* built-in 'fg' and 'bg' handler */
553 static int builtin_fg_bg(struct child_prog *child)
560 /* If they gave us no args, assume they want the last backgrounded task */
561 if (!child->argv[1]) {
562 for (pi = job_list; pi; pi = pi->next) {
563 if (pi->jobid == last_jobid) {
567 bb_error_msg("%s: no current job", child->argv[0]);
570 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
571 bb_error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
574 for (pi = job_list; pi; pi = pi->next) {
575 if (pi->jobid == jobnum) {
579 bb_error_msg("%s: %d: no such job", child->argv[0], jobnum);
582 if (*child->argv[0] == 'f') {
583 /* Put the job into the foreground. */
584 tcsetpgrp(shell_terminal, pi->pgrp);
587 /* Restart the processes in the job */
588 for (i = 0; i < pi->num_progs; i++)
589 pi->progs[i].is_stopped = 0;
591 i = kill(- pi->pgrp, SIGCONT);
593 if (errno == ESRCH) {
596 bb_perror_msg("kill (SIGCONT)");
600 pi->stopped_progs = 0;
604 /* built-in 'help' handler */
605 static int builtin_help(struct child_prog *dummy ATTRIBUTE_UNUSED)
607 const struct built_in_command *x;
609 printf("\nBuilt-in commands:\n");
610 printf("-------------------\n");
611 for (x = bltins; x->cmd; x++) {
612 if (x->descr == NULL)
614 printf("%s\t%s\n", x->cmd, x->descr);
620 /* built-in 'jobs' handler */
621 static int builtin_jobs(struct child_prog *child ATTRIBUTE_UNUSED)
624 const char *status_string;
626 for (job = job_list; job; job = job->next) {
627 if (job->running_progs == job->stopped_progs)
628 status_string = "Stopped";
630 status_string = "Running";
632 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
637 /* built-in 'pwd' handler */
638 static int builtin_pwd(struct child_prog *dummy ATTRIBUTE_UNUSED)
644 /* built-in 'read VAR' handler */
645 static int builtin_read(struct child_prog *child)
649 if (child->argv[1]) {
653 string[0] = '\0'; /* In case stdin has only EOF */
655 fgets(string, sizeof(string), stdin);
657 var = malloc(strlen(child->argv[1]) + strlen(string) + 2);
659 sprintf(var, "%s=%s", child->argv[1], string);
660 res = set_local_var(var, 0);
664 bb_perror_msg("read");
665 free(var); /* So not move up to avoid breaking errno */
668 do res = getchar(); while (res != '\n' && res != EOF);
672 /* built-in 'set VAR=value' handler */
673 static int builtin_set(struct child_prog *child)
675 char *temp = child->argv[1];
679 for (e = top_vars; e; e = e->next)
680 printf("%s=%s\n", e->name, e->value);
682 set_local_var(temp, 0);
688 /* Built-in 'shift' handler */
689 static int builtin_shift(struct child_prog *child)
692 if (child->argv[1]) {
693 n = atoi(child->argv[1]);
695 if (n >= 0 && n < global_argc) {
696 /* XXX This probably breaks $0 */
704 /* Built-in '.' handler (read-in and execute commands from file) */
705 static int builtin_source(struct child_prog *child)
710 if (child->argv[1] == NULL)
713 /* XXX search through $PATH is missing */
714 input = fopen(child->argv[1], "r");
716 bb_error_msg("cannot open '%s'", child->argv[1]);
720 /* Now run the file */
721 /* XXX argv and argc are broken; need to save old global_argv
722 * (pointer only is OK!) on this stack frame,
723 * set global_argv=child->argv+1, recurse, and restore. */
724 mark_open(fileno(input));
725 status = parse_file_outer(input);
726 mark_closed(fileno(input));
731 static int builtin_umask(struct child_prog *child)
734 const char *arg = child->argv[1];
737 new_umask = strtoul(arg, &end, 8);
738 if (*end != '\0' || end == arg) {
742 new_umask = umask(0);
743 printf("%.3o\n", (unsigned) new_umask);
749 /* built-in 'unset VAR' handler */
750 static int builtin_unset(struct child_prog *child)
752 /* bash returned already true */
753 unset_local_var(child->argv[1]);
757 static int builtin_not_written(struct child_prog *child)
759 printf("builtin_%s not written\n", child->argv[0]);
763 static int b_check_space(o_string *o, int len)
765 /* It would be easy to drop a more restrictive policy
766 * in here, such as setting a maximum string length */
767 if (o->length + len > o->maxlen) {
768 char *old_data = o->data;
769 /* assert(data == NULL || o->maxlen != 0); */
770 o->maxlen += max(2*len, B_CHUNK);
771 o->data = realloc(o->data, 1 + o->maxlen);
772 if (o->data == NULL) {
776 return o->data == NULL;
779 static int b_addchr(o_string *o, int ch)
781 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
782 if (b_check_space(o, 1))
784 o->data[o->length] = ch;
786 o->data[o->length] = '\0';
790 static void b_reset(o_string *o)
798 static void b_free(o_string *o)
806 /* My analysis of quoting semantics tells me that state information
807 * is associated with a destination, not a source.
809 static int b_addqchr(o_string *o, int ch, int quote)
811 if (quote && strchr("*?[\\", ch)) {
813 rc = b_addchr(o, '\\');
817 return b_addchr(o, ch);
820 static int b_adduint(o_string *o, unsigned i)
823 char buf[sizeof(unsigned)*3 + 1];
825 *(utoa_to_buf(i, buf, sizeof(buf))) = '\0';
826 /* no escape checking necessary */
827 do r = b_addchr(o, *p++); while (r == 0 && *p);
831 static int static_get(struct in_str *i)
834 if (ch == '\0') return EOF;
838 static int static_peek(struct in_str *i)
843 static void cmdedit_set_initial_prompt(void)
845 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
854 static const char* setup_prompt_string(int promptmode)
856 const char *prompt_str;
857 debug_printf("setup_prompt_string %d ", promptmode);
858 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
859 /* Set up the prompt */
860 if (promptmode == 1) {
863 ns = xmalloc(strlen(cwd)+4);
864 sprintf(ns, "%s %s", cwd, (geteuid() != 0) ? "$ " : "# ");
871 prompt_str = (promptmode == 1) ? PS1 : PS2;
873 debug_printf("result %s\n", prompt_str);
877 #if ENABLE_FEATURE_EDITING
878 static line_input_t *line_input_state;
881 static void get_user_input(struct in_str *i)
883 const char *prompt_str;
884 static char the_command[BUFSIZ];
886 prompt_str = setup_prompt_string(i->promptmode);
887 #if ENABLE_FEATURE_EDITING
889 ** enable command line editing only while a command line
890 ** is actually being read; otherwise, we'll end up bequeathing
891 ** atexit() handlers and other unwanted stuff to our
892 ** child processes (rob@sysgo.de)
894 read_line_input(prompt_str, the_command, BUFSIZ, line_input_state);
896 fputs(prompt_str, stdout);
898 the_command[0] = fgetc(i->file);
899 the_command[1] = '\0';
905 /* This is the magic location that prints prompts
906 * and gets data back from the user */
907 static int file_get(struct in_str *i)
912 /* If there is data waiting, eat it up */
916 /* need to double check i->file because we might be doing something
917 * more complicated by now, like sourcing or substituting. */
918 if (i->__promptme && interactive && i->file == stdin) {
919 while (!i->p || !(interactive && strlen(i->p))) {
931 debug_printf("b_getch: got a %d\n", ch);
938 /* All the callers guarantee this routine will never be
939 * used right after a newline, so prompting is not needed.
941 static int file_peek(struct in_str *i)
946 i->peek_buf[0] = fgetc(i->file);
947 i->peek_buf[1] = '\0';
949 debug_printf("b_peek: got a %d\n", *i->p);
953 static void setup_file_in_str(struct in_str *i, FILE *f)
963 static void setup_string_in_str(struct in_str *i, const char *s)
965 i->peek = static_peek;
972 static void mark_open(int fd)
974 struct close_me *new = xmalloc(sizeof(struct close_me));
976 new->next = close_me_head;
980 static void mark_closed(int fd)
982 struct close_me *tmp;
983 if (close_me_head == NULL || close_me_head->fd != fd)
984 bb_error_msg_and_die("corrupt close_me");
986 close_me_head = close_me_head->next;
990 static void close_all(void)
993 for (c = close_me_head; c; c = c->next) {
996 close_me_head = NULL;
999 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1000 * and stderr if they are redirected. */
1001 static int setup_redirects(struct child_prog *prog, int squirrel[])
1004 struct redir_struct *redir;
1006 for (redir = prog->redirects; redir; redir = redir->next) {
1007 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1008 /* something went wrong in the parse. Pretend it didn't happen */
1011 if (redir->dup == -1) {
1012 mode = redir_table[redir->type].mode;
1013 openfd = open_or_warn(redir->word.gl_pathv[0], mode);
1015 /* this could get lost if stderr has been redirected, but
1016 bash and ash both lose it as well (though zsh doesn't!) */
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",
1065 getpid(), child->argv[i]);
1066 p = insert_var_value(child->argv[i]);
1068 if (p != child->argv[i])
1071 child->argv += i; /* XXX this hack isn't so horrible, since we are about
1072 to exit, and therefore don't need to keep data
1073 structures consistent for free() use. */
1074 /* If a variable is assigned in a forest, and nobody listens,
1075 * was it ever really set?
1077 if (child->argv[0] == NULL) {
1078 _exit(EXIT_SUCCESS);
1082 * Check if the command matches any of the builtins.
1083 * Depending on context, this might be redundant. But it's
1084 * easier to waste a few CPU cycles than it is to figure out
1085 * if this is one of those cases.
1087 for (x = bltins; x->cmd; x++) {
1088 if (strcmp(child->argv[0], x->cmd) == 0) {
1089 debug_printf("builtin exec %s\n", child->argv[0]);
1090 rcode = x->function(child);
1096 /* Check if the command matches any busybox internal commands
1098 * FIXME: This feature is not 100% safe, since
1099 * BusyBox is not fully reentrant, so we have no guarantee the things
1100 * from the .bss are still zeroed, or that things from .data are still
1101 * at their defaults. We could exec ourself from /proc/self/exe, but I
1102 * really dislike relying on /proc for things. We could exec ourself
1103 * from global_argv[0], but if we are in a chroot, we may not be able
1104 * to find ourself... */
1105 #if ENABLE_FEATURE_SH_STANDALONE
1106 debug_printf("running applet %s\n", child->argv[0]);
1107 run_applet_and_exit(child->argv[0], child->argv);
1108 // is it ok that run_applet_and_exit() does exit(), not _exit()?
1109 // NB: IIRC on NOMMU we are after _vfork_, not fork!
1111 debug_printf("exec of %s\n", child->argv[0]);
1112 execvp(child->argv[0], child->argv);
1113 bb_perror_msg("cannot exec: %s", child->argv[0]);
1118 debug_printf("runtime nesting to group\n");
1119 interactive = 0; /* crucial!!!! */
1120 rcode = run_list_real(child->group);
1121 /* OK to leak memory by not calling free_pipe_list,
1122 * since this process is about to exit */
1126 /* Can happen. See what bash does with ">foo" by itself. */
1127 debug_printf("trying to pseudo_exec null command\n");
1128 _exit(EXIT_SUCCESS);
1131 static void insert_bg_job(struct pipe *pi)
1133 struct pipe *thejob;
1135 /* Linear search for the ID of the job to use */
1137 for (thejob = job_list; thejob; thejob = thejob->next)
1138 if (thejob->jobid >= pi->jobid)
1139 pi->jobid = thejob->jobid + 1;
1141 /* add thejob to the list of running jobs */
1143 thejob = job_list = xmalloc(sizeof(*thejob));
1145 for (thejob = job_list; thejob->next; thejob = thejob->next)
1147 thejob->next = xmalloc(sizeof(*thejob));
1148 thejob = thejob->next;
1151 /* physically copy the struct job */
1152 memcpy(thejob, pi, sizeof(struct pipe));
1153 thejob->next = NULL;
1154 thejob->running_progs = thejob->num_progs;
1155 thejob->stopped_progs = 0;
1156 thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1158 //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
1160 char *bar = thejob->text;
1161 char **foo = pi->progs[0].argv;
1164 bar += sprintf(bar, "%s ", *foo++);
1167 /* we don't wait for background thejobs to return -- append it
1168 to the list of backgrounded thejobs and leave it alone */
1169 printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1170 last_bg_pid = thejob->progs[0].pid;
1171 last_jobid = thejob->jobid;
1174 /* remove a backgrounded job */
1175 static void remove_bg_job(struct pipe *pi)
1177 struct pipe *prev_pipe;
1179 if (pi == job_list) {
1180 job_list = pi->next;
1182 prev_pipe = job_list;
1183 while (prev_pipe->next != pi)
1184 prev_pipe = prev_pipe->next;
1185 prev_pipe->next = pi->next;
1188 last_jobid = job_list->jobid;
1192 pi->stopped_progs = 0;
1197 /* Checks to see if any processes have exited -- if they
1198 have, figure out why and see if a job has completed */
1199 static int checkjobs(struct pipe* fg_pipe)
1207 attributes = WUNTRACED;
1208 if (fg_pipe == NULL) {
1209 attributes |= WNOHANG;
1212 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1215 for (i = 0; i < fg_pipe->num_progs; i++) {
1216 if (fg_pipe->progs[i].pid == childpid) {
1217 if (i == fg_pipe->num_progs-1)
1218 rcode = WEXITSTATUS(status);
1219 fg_pipe->num_progs--;
1225 for (pi = job_list; pi; pi = pi->next) {
1227 while (prognum < pi->num_progs) {
1228 if (pi->progs[prognum].pid == childpid)
1229 goto found_pi_and_prognum;
1234 /* Happens when shell is used as init process (init=/bin/sh) */
1235 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1238 found_pi_and_prognum:
1239 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1241 pi->running_progs--;
1242 pi->progs[prognum].pid = 0;
1244 if (!pi->running_progs) {
1245 printf(JOB_STATUS_FORMAT, pi->jobid,
1251 pi->stopped_progs++;
1252 pi->progs[prognum].is_stopped = 1;
1256 if (childpid == -1 && errno != ECHILD)
1257 bb_perror_msg("waitpid");
1259 /* move the shell to the foreground */
1260 //if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
1261 // bb_perror_msg("tcsetpgrp-2");
1265 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1266 * to finish. See checkjobs().
1268 * return code is normally -1, when the caller has to wait for children
1269 * to finish to determine the exit status of the pipe. If the pipe
1270 * is a simple builtin command, however, the action is done by the
1271 * time run_pipe_real returns, and the exit code is provided as the
1274 * The input of the pipe is always stdin, the output is always
1275 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1276 * because it tries to avoid running the command substitution in
1277 * subshell, when that is in fact necessary. The subshell process
1278 * now has its stdout directed to the input of the appropriate pipe,
1279 * so this routine is noticeably simpler.
1281 static int run_pipe_real(struct pipe *pi)
1284 int nextin, nextout;
1285 int pipefds[2]; /* pipefds[0] is for reading */
1286 struct child_prog *child;
1287 const struct built_in_command *x;
1289 /* it is not always needed, but we aim to smaller code */
1290 int squirrel[] = { -1, -1, -1 };
1296 /* Check if this is a simple builtin (not part of a pipe).
1297 * Builtins within pipes have to fork anyway, and are handled in
1298 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1300 child = &(pi->progs[0]);
1301 if (pi->num_progs == 1 && child->group && child->subshell == 0) {
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);
1311 if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1312 for (i = 0; is_assignment(child->argv[i]); i++)
1314 if (i != 0 && child->argv[i] == NULL) {
1315 /* assignments, but no command: set the local environment */
1316 for (i = 0; child->argv[i] != NULL; i++) {
1317 /* Ok, this case is tricky. We have to decide if this is a
1318 * local variable, or an already exported variable. If it is
1319 * already exported, we have to export the new value. If it is
1320 * not exported, we need only set this as a local variable.
1321 * This junk is all to decide whether or not to export this
1325 name = xstrdup(child->argv[i]);
1326 debug_printf("Local environment set: %s\n", name);
1327 value = strchr(name, '=');
1330 if (get_local_var(name)) {
1334 p = insert_var_value(child->argv[i]);
1335 set_local_var(p, export_me);
1336 if (p != child->argv[i])
1339 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1341 for (i = 0; is_assignment(child->argv[i]); i++) {
1342 p = insert_var_value(child->argv[i]);
1344 if (p != child->argv[i]) {
1352 str = make_string(child->argv + i);
1353 parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1355 return last_return_code;
1357 for (x = bltins; x->cmd; x++) {
1358 if (strcmp(child->argv[i], x->cmd) == 0) {
1359 if (x->function == builtin_exec && child->argv[i+1] == NULL) {
1360 debug_printf("magic exec\n");
1361 setup_redirects(child, NULL);
1362 return EXIT_SUCCESS;
1364 debug_printf("builtin inline %s\n", child->argv[0]);
1365 /* XXX setup_redirects acts on file descriptors, not FILEs.
1366 * This is perfect for work that comes after exec().
1367 * Is it really safe for inline use? Experimentally,
1368 * things seem to work with glibc. */
1369 setup_redirects(child, squirrel);
1370 child->argv += i; /* XXX horrible hack */
1371 rcode = x->function(child);
1372 child->argv -= i; /* XXX restore hack so free() can work right */
1373 restore_redirects(squirrel);
1377 #if ENABLE_FEATURE_SH_STANDALONE
1379 const struct bb_applet *a = find_applet_by_name(child->argv[i]);
1380 if (a && a->nofork) {
1381 setup_redirects(child, squirrel);
1382 rcode = run_nofork_applet(a, child->argv + i);
1383 restore_redirects(squirrel);
1390 for (i = 0; i < pi->num_progs; i++) {
1391 child = &(pi->progs[i]);
1393 /* pipes are inserted between pairs of commands */
1394 if ((i + 1) < pi->num_progs) {
1395 if (pipe(pipefds) < 0)
1396 bb_perror_msg_and_die("pipe");
1397 nextout = pipefds[1];
1403 /* XXX test for failed fork()? */
1405 child->pid = fork();
1407 child->pid = vfork();
1410 /* Set the handling for job control signals back to the default. */
1411 signal(SIGINT, SIG_DFL);
1412 signal(SIGQUIT, SIG_DFL);
1413 signal(SIGTERM, SIG_DFL);
1414 signal(SIGTSTP, SIG_DFL);
1415 signal(SIGTTIN, SIG_DFL);
1416 signal(SIGTTOU, SIG_DFL);
1417 signal(SIGCHLD, SIG_DFL);
1429 if (pipefds[0] != -1) {
1430 close(pipefds[0]); /* opposite end of our output pipe */
1433 /* Like bash, explicit redirects override pipes,
1434 * and the pipe fd is available for dup'ing. */
1435 setup_redirects(child, NULL);
1437 if (interactive && pi->followup != PIPE_BG) {
1438 /* If we (the child) win the race, put ourselves in the process
1439 * group whose leader is the first process in this pipe. */
1441 pi->pgrp = getpid();
1443 if (setpgid(0, pi->pgrp) == 0) {
1444 tcsetpgrp(2, pi->pgrp);
1451 /* put our child in the process group whose leader is the
1452 first process in this pipe */
1454 pi->pgrp = child->pid;
1456 /* Don't check for errors. The child may be dead already,
1457 * in which case setpgid returns error code EACCES. */
1458 setpgid(child->pid, pi->pgrp);
1465 /* If there isn't another process, nextin is garbage
1466 but it doesn't matter */
1467 nextin = pipefds[0];
1472 static int run_list_real(struct pipe *pi)
1474 char *save_name = NULL;
1476 char **save_list = NULL;
1480 int rcode = 0, flag_skip = 1;
1481 int flag_restore = 0;
1482 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
1483 reserved_style rmode, skip_more_in_this_rmode = RES_XXXX;
1484 /* check syntax for "for" */
1485 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1486 if ((rpipe->r_mode == RES_IN || rpipe->r_mode == RES_FOR)
1487 && (rpipe->next == NULL)
1492 if ((rpipe->r_mode == RES_IN && rpipe->next->r_mode == RES_IN && rpipe->next->progs->argv != NULL)
1493 || (rpipe->r_mode == RES_FOR && rpipe->next->r_mode != RES_IN)
1499 for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1500 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL
1501 || pi->r_mode == RES_FOR
1510 debug_printf("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n",
1511 rmode, if_code, next_if_code, skip_more_in_this_rmode);
1512 if (rmode == skip_more_in_this_rmode && flag_skip) {
1513 if (pi->followup == PIPE_SEQ)
1518 skip_more_in_this_rmode = RES_XXXX;
1519 if (rmode == RES_THEN || rmode == RES_ELSE)
1520 if_code = next_if_code;
1521 if (rmode == RES_THEN && if_code)
1523 if (rmode == RES_ELSE && !if_code)
1525 if (rmode == RES_ELIF && !if_code)
1527 if (rmode == RES_FOR && pi->num_progs) {
1529 /* if no variable values after "in" we skip "for" */
1530 if (!pi->next->progs->argv)
1532 /* create list of variable values */
1533 list = make_list_in(pi->next->progs->argv,
1534 pi->progs->argv[0]);
1536 save_name = pi->progs->argv[0];
1537 pi->progs->argv[0] = NULL;
1541 free(pi->progs->argv[0]);
1545 pi->progs->argv[0] = save_name;
1546 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
1549 /* insert new value from list for variable */
1550 if (pi->progs->argv[0])
1551 free(pi->progs->argv[0]);
1552 pi->progs->argv[0] = *list++;
1553 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
1555 if (rmode == RES_IN)
1557 if (rmode == RES_DO) {
1561 if (rmode == RES_DONE) {
1568 if (pi->num_progs == 0)
1570 save_num_progs = pi->num_progs; /* save number of programs */
1571 rcode = run_pipe_real(pi);
1572 debug_printf("run_pipe_real returned %d\n", rcode);
1574 /* We only ran a builtin: rcode was set by the return value
1575 * of run_pipe_real(), and we don't need to wait for anything. */
1576 } else if (pi->followup == PIPE_BG) {
1577 /* XXX check bash's behavior with nontrivial pipes */
1578 /* XXX compute jobid */
1579 /* XXX what does bash do with attempts to background builtins? */
1581 rcode = EXIT_SUCCESS;
1584 /* move the new process group into the foreground */
1585 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1586 bb_perror_msg("tcsetpgrp-3");
1587 rcode = checkjobs(pi);
1588 /* move the shell to the foreground */
1589 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1590 bb_perror_msg("tcsetpgrp-4");
1592 rcode = checkjobs(pi);
1594 debug_printf("checkjobs returned %d\n", rcode);
1596 last_return_code = rcode;
1597 pi->num_progs = save_num_progs; /* restore number of programs */
1598 if (rmode == RES_IF || rmode == RES_ELIF)
1599 next_if_code = rcode; /* can be overwritten a number of times */
1600 if (rmode == RES_WHILE)
1601 flag_rep = !last_return_code;
1602 if (rmode == RES_UNTIL)
1603 flag_rep = last_return_code;
1604 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
1605 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
1607 skip_more_in_this_rmode = rmode;
1614 /* return code is the exit status of the pipe */
1615 static int free_pipe(struct pipe *pi, int indent)
1618 struct child_prog *child;
1619 struct redir_struct *r, *rnext;
1620 int a, i, ret_code = 0;
1622 if (pi->stopped_progs > 0)
1624 final_printf("%s run pipe: (pid %d)\n", indenter(indent), getpid());
1625 for (i = 0; i < pi->num_progs; i++) {
1626 child = &pi->progs[i];
1627 final_printf("%s command %d:\n", indenter(indent), i);
1629 for (a = 0, p = child->argv; *p; a++, p++) {
1630 final_printf("%s argv[%d] = %s\n", indenter(indent), a, *p);
1632 globfree(&child->glob_result);
1634 } else if (child->group) {
1635 final_printf("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
1636 ret_code = free_pipe_list(child->group, indent+3);
1637 final_printf("%s end group\n", indenter(indent));
1639 final_printf("%s (nil)\n", indenter(indent));
1641 for (r = child->redirects; r; r = rnext) {
1642 final_printf("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
1644 /* guard against the case >$FOO, where foo is unset or blank */
1645 if (r->word.gl_pathv) {
1646 final_printf(" %s\n", *r->word.gl_pathv);
1650 final_printf("&%d\n", r->dup);
1655 child->redirects = NULL;
1657 free(pi->progs); /* children are an array, they get freed all at once */
1662 static int free_pipe_list(struct pipe *head, int indent)
1664 int rcode = 0; /* if list has no members */
1665 struct pipe *pi, *next;
1666 for (pi = head; pi; pi = next) {
1667 final_printf("%s pipe reserved mode %d\n", indenter(indent), pi->r_mode);
1668 rcode = free_pipe(pi, indent);
1669 final_printf("%s pipe followup code %d\n", indenter(indent), pi->followup);
1671 /*pi->next = NULL;*/
1677 /* Select which version we will use */
1678 static int run_list(struct pipe *pi)
1681 if (fake_mode == 0) {
1682 rcode = run_list_real(pi);
1684 /* free_pipe_list has the side effect of clearing memory
1685 * In the long run that function can be merged with run_list_real,
1686 * but doing that now would hobble the debugging effort. */
1687 free_pipe_list(pi,0);
1691 /* The API for glob is arguably broken. This routine pushes a non-matching
1692 * string into the output structure, removing non-backslashed backslashes.
1693 * If someone can prove me wrong, by performing this function within the
1694 * original glob(3) api, feel free to rewrite this routine into oblivion.
1695 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1696 * XXX broken if the last character is '\\', check that before calling.
1698 static int globhack(const char *src, int flags, glob_t *pglob)
1703 for (cnt = 1, s = src; s && *s; s++) {
1704 if (*s == '\\') s++;
1709 return GLOB_NOSPACE;
1710 if (!(flags & GLOB_APPEND)) {
1711 pglob->gl_pathv = NULL;
1712 pglob->gl_pathc = 0;
1716 pathc = ++pglob->gl_pathc;
1717 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1718 if (pglob->gl_pathv == NULL)
1719 return GLOB_NOSPACE;
1720 pglob->gl_pathv[pathc-1] = dest;
1721 pglob->gl_pathv[pathc] = NULL;
1722 for (s = src; s && *s; s++, dest++) {
1723 if (*s == '\\') s++;
1730 /* XXX broken if the last character is '\\', check that before calling */
1731 static int glob_needed(const char *s)
1734 if (*s == '\\') s++;
1735 if (strchr("*[?", *s)) return 1;
1740 static int xglob(o_string *dest, int flags, glob_t *pglob)
1744 /* short-circuit for null word */
1745 /* we can code this better when the debug_printf's are gone */
1746 if (dest->length == 0) {
1747 if (dest->nonnull) {
1748 /* bash man page calls this an "explicit" null */
1749 gr = globhack(dest->data, flags, pglob);
1750 debug_printf("globhack returned %d\n", gr);
1754 } else if (glob_needed(dest->data)) {
1755 gr = glob(dest->data, flags, NULL, pglob);
1756 debug_printf("glob returned %d\n", gr);
1757 if (gr == GLOB_NOMATCH) {
1758 /* quote removal, or more accurately, backslash removal */
1759 gr = globhack(dest->data, flags, pglob);
1760 debug_printf("globhack returned %d\n", gr);
1763 gr = globhack(dest->data, flags, pglob);
1764 debug_printf("globhack returned %d\n", gr);
1766 if (gr == GLOB_NOSPACE)
1767 bb_error_msg_and_die("out of memory during glob");
1768 if (gr != 0) { /* GLOB_ABORTED ? */
1769 bb_error_msg("glob(3) error %d", gr);
1771 /* globprint(glob_target); */
1775 /* This is used to get/check local shell variables */
1776 static const char *get_local_var(const char *s)
1778 struct variables *cur;
1782 for (cur = top_vars; cur; cur = cur->next)
1783 if (strcmp(cur->name, s) == 0)
1788 /* This is used to set local shell variables
1789 flg_export == 0 if only local (not exporting) variable
1790 flg_export == 1 if "new" exporting environ
1791 flg_export > 1 if current startup environ (not call putenv()) */
1792 static int set_local_var(const char *s, int flg_export)
1796 struct variables *cur;
1800 /* Assume when we enter this function that we are already in
1801 * NAME=VALUE format. So the first order of business is to
1802 * split 's' on the '=' into 'name' and 'value' */
1803 value = strchr(name, '=');
1804 /*if (value == 0 && ++value == 0) ??? -vda */
1805 if (value == NULL || value[1] == '\0') {
1811 for (cur = top_vars; cur; cur = cur->next) {
1812 if (strcmp(cur->name, name) == 0)
1817 if (strcmp(cur->value, value) == 0) {
1818 if (flg_export > 0 && cur->flg_export == 0)
1819 cur->flg_export = flg_export;
1822 } else if (cur->flg_read_only) {
1823 bb_error_msg("%s: readonly variable", name);
1826 if (flg_export > 0 || cur->flg_export > 1)
1827 cur->flg_export = 1;
1828 free((char*)cur->value);
1830 cur->value = strdup(value);
1833 cur = malloc(sizeof(struct variables));
1837 cur->name = strdup(name);
1842 struct variables *bottom = top_vars;
1843 cur->value = strdup(value);
1845 cur->flg_export = flg_export;
1846 cur->flg_read_only = 0;
1847 while (bottom->next)
1848 bottom = bottom->next;
1854 if (result == 0 && cur->flg_export == 1) {
1856 result = putenv(name);
1859 if (result > 0) /* equivalent to previous set */
1865 static void unset_local_var(const char *name)
1867 struct variables *cur, *next;
1871 for (cur = top_vars; cur; cur = cur->next) {
1872 if (strcmp(cur->name, name) == 0) {
1873 if (cur->flg_read_only) {
1874 bb_error_msg("%s: readonly variable", name);
1877 if (cur->flg_export)
1878 unsetenv(cur->name);
1879 free((char*)cur->name);
1880 free((char*)cur->value);
1882 while (next->next != cur)
1884 next->next = cur->next;
1891 static int is_assignment(const char *s)
1893 if (!s || !isalpha(*s))
1896 while (isalnum(*s) || *s == '_')
1901 /* the src parameter allows us to peek forward to a possible &n syntax
1902 * for file descriptor duplication, e.g., "2>&1".
1903 * Return code is 0 normally, 1 if a syntax error is detected in src.
1904 * Resource errors (in xmalloc) cause the process to exit */
1905 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1906 struct in_str *input)
1908 struct child_prog *child = ctx->child;
1909 struct redir_struct *redir = child->redirects;
1910 struct redir_struct *last_redir = NULL;
1912 /* Create a new redir_struct and drop it onto the end of the linked list */
1915 redir = redir->next;
1917 redir = xmalloc(sizeof(struct redir_struct));
1919 redir->word.gl_pathv = NULL;
1921 last_redir->next = redir;
1923 child->redirects = redir;
1926 redir->type = style;
1927 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
1929 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1931 /* Check for a '2>&1' type redirect */
1932 redir->dup = redirect_dup_num(input);
1933 if (redir->dup == -2) return 1; /* syntax error */
1934 if (redir->dup != -1) {
1935 /* Erik had a check here that the file descriptor in question
1936 * is legit; I postpone that to "run time"
1937 * A "-" representation of "close me" shows up as a -3 here */
1938 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
1940 /* We do _not_ try to open the file that src points to,
1941 * since we need to return and let src be expanded first.
1942 * Set ctx->pending_redirect, so we know what to do at the
1943 * end of the next parsed word.
1945 ctx->pending_redirect = redir;
1950 static struct pipe *new_pipe(void)
1953 pi = xmalloc(sizeof(struct pipe));
1957 pi->followup = 0; /* invalid */
1958 pi->r_mode = RES_NONE;
1962 static void initialize_context(struct p_context *ctx)
1965 ctx->pending_redirect = NULL;
1967 ctx->list_head = new_pipe();
1968 ctx->pipe = ctx->list_head;
1972 done_command(ctx); /* creates the memory for working child */
1975 /* normal return is 0
1976 * if a reserved word is found, and processed, return 1
1977 * should handle if, then, elif, else, fi, for, while, until, do, done.
1978 * case, function, and select are obnoxious, save those for later.
1980 static int reserved_word(o_string *dest, struct p_context *ctx)
1982 struct reserved_combo {
1987 /* Mostly a list of accepted follow-up reserved words.
1988 * FLAG_END means we are done with the sequence, and are ready
1989 * to turn the compound list into a command.
1990 * FLAG_START means the word must start a new compound list.
1992 static const struct reserved_combo reserved_list[] = {
1993 { "if", RES_IF, FLAG_THEN | FLAG_START },
1994 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
1995 { "elif", RES_ELIF, FLAG_THEN },
1996 { "else", RES_ELSE, FLAG_FI },
1997 { "fi", RES_FI, FLAG_END },
1998 { "for", RES_FOR, FLAG_IN | FLAG_START },
1999 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2000 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2001 { "in", RES_IN, FLAG_DO },
2002 { "do", RES_DO, FLAG_DONE },
2003 { "done", RES_DONE, FLAG_END }
2005 enum { NRES = sizeof(reserved_list)/sizeof(reserved_list[0]) };
2006 const struct reserved_combo *r;
2008 for (r = reserved_list; r < reserved_list+NRES; r++) {
2009 if (strcmp(dest->data, r->literal) == 0) {
2010 debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
2011 if (r->flag & FLAG_START) {
2012 struct p_context *new = xmalloc(sizeof(struct p_context));
2013 debug_printf("push stack\n");
2014 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2021 *new = *ctx; /* physical copy */
2022 initialize_context(ctx);
2024 } else if (ctx->w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
2031 ctx->old_flag = r->flag;
2032 if (ctx->old_flag & FLAG_END) {
2033 struct p_context *old;
2034 debug_printf("pop stack\n");
2035 done_pipe(ctx, PIPE_SEQ);
2037 old->child->group = ctx->list_head;
2038 old->child->subshell = 0;
2039 *ctx = *old; /* physical copy */
2049 /* normal return is 0.
2050 * Syntax or xglob errors return 1. */
2051 static int done_word(o_string *dest, struct p_context *ctx)
2053 struct child_prog *child = ctx->child;
2054 glob_t *glob_target;
2057 debug_printf("done_word: %s %p\n", dest->data, child);
2058 if (dest->length == 0 && !dest->nonnull) {
2059 debug_printf(" true null, ignored\n");
2062 if (ctx->pending_redirect) {
2063 glob_target = &ctx->pending_redirect->word;
2067 return 1; /* syntax error, groups and arglists don't mix */
2069 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2070 debug_printf("checking %s for reserved-ness\n", dest->data);
2071 if (reserved_word(dest, ctx))
2072 return (ctx->w == RES_SNTX);
2074 glob_target = &child->glob_result;
2075 if (child->argv) flags |= GLOB_APPEND;
2077 gr = xglob(dest, flags, glob_target);
2078 if (gr != 0) return 1;
2081 if (ctx->pending_redirect) {
2082 ctx->pending_redirect = NULL;
2083 if (glob_target->gl_pathc != 1) {
2084 bb_error_msg("ambiguous redirect");
2088 child->argv = glob_target->gl_pathv;
2090 if (ctx->w == RES_FOR) {
2091 done_word(dest, ctx);
2092 done_pipe(ctx, PIPE_SEQ);
2097 /* The only possible error here is out of memory, in which case
2099 static int done_command(struct p_context *ctx)
2101 /* The child is really already in the pipe structure, so
2102 * advance the pipe counter and make a new, null child.
2103 * Only real trickiness here is that the uncommitted
2104 * child structure, to which ctx->child points, is not
2105 * counted in pi->num_progs. */
2106 struct pipe *pi = ctx->pipe;
2107 struct child_prog *prog = ctx->child;
2109 if (prog && prog->group == NULL
2110 && prog->argv == NULL
2111 && prog->redirects == NULL
2113 debug_printf("done_command: skipping null command\n");
2118 debug_printf("done_command: num_progs incremented to %d\n", pi->num_progs);
2120 debug_printf("done_command: initializing\n");
2122 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2124 prog = pi->progs + pi->num_progs;
2125 prog->redirects = NULL;
2127 prog->is_stopped = 0;
2129 prog->glob_result.gl_pathv = NULL;
2133 prog->type = ctx->type;
2135 /* but ctx->pipe and ctx->list_head remain unchanged */
2139 static int done_pipe(struct p_context *ctx, pipe_style type)
2142 done_command(ctx); /* implicit closure of previous command */
2143 debug_printf("done_pipe, type %d\n", type);
2144 ctx->pipe->followup = type;
2145 ctx->pipe->r_mode = ctx->w;
2147 ctx->pipe->next = new_p;
2150 done_command(ctx); /* set up new pipe to accept commands */
2154 /* peek ahead in the in_str to find out if we have a "&n" construct,
2155 * as in "2>&1", that represents duplicating a file descriptor.
2156 * returns either -2 (syntax error), -1 (no &), or the number found.
2158 static int redirect_dup_num(struct in_str *input)
2160 int ch, d = 0, ok = 0;
2162 if (ch != '&') return -1;
2164 b_getch(input); /* get the & */
2168 return -3; /* "-" represents "close me" */
2170 while (isdigit(ch)) {
2171 d = d*10 + (ch-'0');
2178 bb_error_msg("ambiguous redirect");
2182 /* If a redirect is immediately preceded by a number, that number is
2183 * supposed to tell which file descriptor to redirect. This routine
2184 * looks for such preceding numbers. In an ideal world this routine
2185 * needs to handle all the following classes of redirects...
2186 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2187 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2188 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2189 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2190 * A -1 output from this program means no valid number was found, so the
2191 * caller should use the appropriate default for this redirection.
2193 static int redirect_opt_num(o_string *o)
2199 for (num = 0; num < o->length; num++) {
2200 if (!isdigit(*(o->data + num))) {
2204 /* reuse num (and save an int) */
2205 num = atoi(o->data);
2210 static FILE *generate_stream_from_list(struct pipe *head)
2213 int pid, channel[2];
2214 if (pipe(channel) < 0) bb_perror_msg_and_die("pipe");
2221 bb_perror_msg_and_die("fork");
2222 } else if (pid == 0) {
2224 if (channel[1] != 1) {
2225 dup2(channel[1], 1);
2228 _exit(run_list_real(head)); /* leaks memory */
2230 debug_printf("forked child %d\n", pid);
2232 pf = fdopen(channel[0], "r");
2233 debug_printf("pipe on FILE *%p\n", pf);
2237 /* this version hacked for testing purposes */
2238 /* return code is exit status of the process that is run. */
2239 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2242 o_string result = NULL_O_STRING;
2243 struct p_context inner;
2245 struct in_str pipe_str;
2246 initialize_context(&inner);
2248 /* recursion to generate command */
2249 retcode = parse_stream(&result, &inner, input, subst_end);
2250 if (retcode != 0) return retcode; /* syntax error or EOF */
2251 done_word(&result, &inner);
2252 done_pipe(&inner, PIPE_SEQ);
2255 p = generate_stream_from_list(inner.list_head);
2256 if (p == NULL) return 1;
2257 mark_open(fileno(p));
2258 setup_file_in_str(&pipe_str, p);
2260 /* now send results of command back into original context */
2261 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2262 /* XXX In case of a syntax error, should we try to kill the child?
2263 * That would be tough to do right, so just read until EOF. */
2265 while (b_getch(&pipe_str) != EOF)
2269 debug_printf("done reading from pipe, pclose()ing\n");
2270 /* This is the step that wait()s for the child. Should be pretty
2271 * safe, since we just read an EOF from its stdout. We could try
2272 * to better, by using wait(), and keeping track of background jobs
2273 * at the same time. That would be a lot of work, and contrary
2274 * to the KISS philosophy of this program. */
2275 mark_closed(fileno(p));
2276 retcode = pclose(p);
2277 free_pipe_list(inner.list_head, 0);
2278 debug_printf("pclosed, retcode=%d\n", retcode);
2279 /* XXX this process fails to trim a single trailing newline */
2283 static int parse_group(o_string *dest, struct p_context *ctx,
2284 struct in_str *input, int ch)
2286 int rcode, endch = 0;
2287 struct p_context sub;
2288 struct child_prog *child = ctx->child;
2291 return 1; /* syntax error, groups and arglists don't mix */
2293 initialize_context(&sub);
2297 child->subshell = 1;
2303 syntax(); /* really logic error */
2305 rcode = parse_stream(dest, &sub, input, endch);
2306 done_word(dest, &sub); /* finish off the final word in the subcontext */
2307 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2308 child->group = sub.list_head;
2310 /* child remains "open", available for possible redirects */
2313 /* basically useful version until someone wants to get fancier,
2314 * see the bash man page under "Parameter Expansion" */
2315 static const char *lookup_param(const char *src)
2317 const char *p = NULL;
2321 p = get_local_var(src);
2326 /* return code: 0 for OK, 1 for syntax error */
2327 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2331 int ch = input->peek(input); /* first character after the $ */
2332 debug_printf("handle_dollar: ch=%c\n", ch);
2334 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2336 while (ch = b_peek(input), isalnum(ch) || ch == '_') {
2340 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2341 } else if (isdigit(ch)) {
2342 i = ch - '0'; /* XXX is $0 special? */
2343 if (i < global_argc) {
2344 parse_string(dest, ctx, global_argv[i]); /* recursion */
2347 } else switch (ch) {
2349 b_adduint(dest, getpid());
2353 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2357 b_adduint(dest, last_return_code);
2361 b_adduint(dest, global_argc ? global_argc-1 : 0);
2365 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2368 /* XXX maybe someone will try to escape the '}' */
2370 ch = b_getch(input);
2371 if (ch == EOF || ch == '}')
2379 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2383 process_command_subs(dest, ctx, input, ')');
2387 for (i = 1; i < global_argc; i++) {
2388 parse_string(dest, ctx, global_argv[i]);
2389 if (i+1 < global_argc)
2390 parse_string(dest, ctx, sep);
2396 /* still unhandled, but should be eventually */
2397 bb_error_msg("unhandled syntax: $%c", ch);
2401 b_addqchr(dest,'$', dest->quote);
2403 /* Eat the character if the flag was set. If the compiler
2404 * is smart enough, we could substitute "b_getch(input);"
2405 * for all the "advance = 1;" above, and also end up with
2406 * a nice size-optimized program. Hah! That'll be the day.
2408 if (advance) b_getch(input);
2412 static int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2415 setup_string_in_str(&foo, src);
2416 return parse_stream(dest, ctx, &foo, '\0');
2419 /* return code is 0 for normal exit, 1 for syntax error */
2420 static int parse_stream(o_string *dest, struct p_context *ctx,
2421 struct in_str *input, int end_trigger)
2425 redir_type redir_style;
2428 /* Only double-quote state is handled in the state variable dest->quote.
2429 * A single-quote triggers a bypass of the main loop until its mate is
2430 * found. When recursing, quote state is passed in via dest->quote. */
2432 debug_printf("parse_stream, end_trigger=%d\n", end_trigger);
2433 while ((ch = b_getch(input)) != EOF) {
2435 next = (ch == '\n') ? 0 : b_peek(input);
2436 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2437 ch, ch, m, dest->quote);
2438 if (m == 0 || ((m == 1 || m == 2) && dest->quote)) {
2439 b_addqchr(dest, ch, dest->quote);
2442 if (m == 2) { /* unquoted IFS */
2443 if (done_word(dest, ctx)) {
2446 /* If we aren't performing a substitution, treat a newline as a
2447 * command separator. */
2448 if (end_trigger != '\0' && ch == '\n')
2449 done_pipe(ctx, PIPE_SEQ);
2451 if (ch == end_trigger && !dest->quote && ctx->w == RES_NONE) {
2452 debug_printf("leaving parse_stream (triggered)\n");
2459 if (dest->length == 0 && !dest->quote) {
2462 if (ch == EOF || ch == '\n')
2467 b_addqchr(dest, ch, dest->quote);
2475 b_addqchr(dest, '\\', dest->quote);
2476 b_addqchr(dest, b_getch(input), dest->quote);
2479 if (handle_dollar(dest, ctx, input) != 0) return 1;
2484 ch = b_getch(input);
2485 if (ch == EOF || ch == '\'')
2496 dest->quote = !dest->quote;
2499 process_command_subs(dest, ctx, input, '`');
2502 redir_fd = redirect_opt_num(dest);
2503 done_word(dest, ctx);
2504 redir_style = REDIRECT_OVERWRITE;
2506 redir_style = REDIRECT_APPEND;
2508 } else if (next == '(') {
2509 syntax(); /* until we support >(list) Process Substitution */
2512 setup_redirect(ctx, redir_fd, redir_style, input);
2515 redir_fd = redirect_opt_num(dest);
2516 done_word(dest, ctx);
2517 redir_style = REDIRECT_INPUT;
2519 redir_style = REDIRECT_HEREIS;
2521 } else if (next == '>') {
2522 redir_style = REDIRECT_IO;
2524 } else if (next == '(') {
2525 syntax(); /* until we support <(list) Process Substitution */
2528 setup_redirect(ctx, redir_fd, redir_style, input);
2531 done_word(dest, ctx);
2532 done_pipe(ctx, PIPE_SEQ);
2535 done_word(dest, ctx);
2538 done_pipe(ctx, PIPE_AND);
2540 done_pipe(ctx, PIPE_BG);
2544 done_word(dest, ctx);
2547 done_pipe(ctx, PIPE_OR);
2549 /* we could pick up a file descriptor choice here
2550 * with redirect_opt_num(), but bash doesn't do it.
2551 * "echo foo 2| cat" yields "foo 2". */
2557 if (parse_group(dest, ctx, input, ch) != 0)
2562 syntax(); /* Proper use of this character caught by end_trigger */
2565 syntax(); /* this is really an internal logic error */
2569 /* complain if quote? No, maybe we just finished a command substitution
2570 * that was quoted. Example:
2571 * $ echo "`cat foo` plus more"
2572 * and we just got the EOF generated by the subshell that ran "cat foo"
2573 * The only real complaint is if we got an EOF when end_trigger != '\0',
2574 * that is, we were really supposed to get end_trigger, and never got
2575 * one before the EOF. Can't use the standard "syntax error" return code,
2576 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
2577 debug_printf("leaving parse_stream (EOF)\n");
2578 if (end_trigger != '\0')
2583 static void mapset(const char *set, int code)
2586 map[(unsigned char)*set++] = code;
2589 static void update_ifs_map(void)
2591 /* char *ifs and char map[256] are both globals. */
2592 ifs = getenv("IFS");
2593 if (ifs == NULL) ifs = " \t\n";
2594 /* Precompute a list of 'flow through' behavior so it can be treated
2595 * quickly up front. Computation is necessary because of IFS.
2596 * Special case handling of IFS == " \t\n" is not implemented.
2597 * The map[] array only really needs two bits each, and on most machines
2598 * that would be faster because of the reduced L1 cache footprint.
2600 memset(map, 0, sizeof(map)); /* most characters flow through always */
2601 mapset("\\$'\"`", 3); /* never flow through */
2602 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2603 mapset(ifs, 2); /* also flow through if quoted */
2606 /* most recursion does not come through here, the exception is
2607 * from builtin_source() */
2608 static int parse_stream_outer(struct in_str *inp, int flag)
2610 struct p_context ctx;
2611 o_string temp = NULL_O_STRING;
2615 initialize_context(&ctx);
2617 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
2618 inp->promptmode = 1;
2619 rcode = parse_stream(&temp, &ctx, inp, '\n');
2620 if (rcode != 1 && ctx.old_flag != 0) {
2623 if (rcode != 1 && ctx.old_flag == 0) {
2624 done_word(&temp, &ctx);
2625 done_pipe(&ctx, PIPE_SEQ);
2626 run_list(ctx.list_head);
2628 if (ctx.old_flag != 0) {
2635 free_pipe_list(ctx.list_head,0);
2638 } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
2642 static int parse_string_outer(const char *s, int flag)
2644 struct in_str input;
2645 setup_string_in_str(&input, s);
2646 return parse_stream_outer(&input, flag);
2649 static int parse_file_outer(FILE *f)
2652 struct in_str input;
2653 setup_file_in_str(&input, f);
2654 rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
2658 /* Make sure we have a controlling tty. If we get started under a job
2659 * aware app (like bash for example), make sure we are now in charge so
2660 * we don't fight over who gets the foreground */
2661 static void setup_job_control(void)
2663 /*static --why?? */ pid_t shell_pgrp;
2665 /* Loop until we are in the foreground. */
2666 while (tcgetpgrp(shell_terminal) != (shell_pgrp = getpgrp()))
2667 kill(- shell_pgrp, SIGTTIN);
2669 /* Ignore interactive and job-control signals. */
2670 signal(SIGINT, SIG_IGN);
2671 signal(SIGQUIT, SIG_IGN);
2672 signal(SIGTERM, SIG_IGN);
2673 signal(SIGTSTP, SIG_IGN);
2674 signal(SIGTTIN, SIG_IGN);
2675 signal(SIGTTOU, SIG_IGN);
2676 signal(SIGCHLD, SIG_IGN);
2678 /* Put ourselves in our own process group. */
2680 shell_pgrp = getpid();
2681 setpgid(shell_pgrp, shell_pgrp);
2683 /* Grab control of the terminal. */
2684 tcsetpgrp(shell_terminal, shell_pgrp);
2687 int hush_main(int argc, char **argv);
2688 int hush_main(int argc, char **argv)
2694 #if ENABLE_FEATURE_EDITING
2695 line_input_state = new_line_input_t(FOR_SHELL);
2698 /* XXX what should these be while sourcing /etc/profile? */
2702 /* (re?) initialize globals. Sometimes hush_main() ends up calling
2703 * hush_main(), therefore we cannot rely on the BSS to zero out this
2704 * stuff. Reset these to 0 every time. */
2706 /* map[] is taken care of with call to update_ifs_map() */
2709 close_me_head = NULL;
2714 /* Initialize some more globals to non-zero values */
2716 if (ENABLE_FEATURE_EDITING)
2717 cmdedit_set_initial_prompt();
2721 /* initialize our shell local variables with the values
2722 * currently living in the environment */
2726 set_local_var(*e++, 2); /* without call putenv() */
2728 last_return_code = EXIT_SUCCESS;
2730 if (argv[0] && argv[0][0] == '-') {
2731 debug_printf("\nsourcing /etc/profile\n");
2732 input = fopen("/etc/profile", "r");
2733 if (input != NULL) {
2734 mark_open(fileno(input));
2735 parse_file_outer(input);
2736 mark_closed(fileno(input));
2742 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2745 global_argv = argv + optind;
2746 global_argc = argc - optind;
2747 opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
2757 fprintf(stderr, "Usage: sh [FILE]...\n"
2758 " or: sh -c command [args]...\n\n");
2765 /* A shell is interactive if the '-i' flag was given, or if all of
2766 * the following conditions are met:
2768 * no arguments remaining or the -s flag given
2769 * standard input is a terminal
2770 * standard output is a terminal
2771 * Refer to Posix.2, the description of the 'sh' utility. */
2772 if (argv[optind] == NULL && input == stdin
2773 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
2778 debug_printf("\ninteractive=%d\n", interactive);
2780 /* Looks like they want an interactive shell */
2781 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
2782 printf( "\n\n%s hush - the humble shell v0.01 (testing)\n",
2784 printf( "Enter 'help' for a list of built-in commands.\n\n");
2786 setup_job_control();
2789 if (argv[optind] == NULL) {
2790 opt = parse_file_outer(stdin);
2794 debug_printf("\nrunning script '%s'\n", argv[optind]);
2795 global_argv = argv + optind;
2796 global_argc = argc - optind;
2797 input = xfopen(argv[optind], "r");
2798 opt = parse_file_outer(input);
2800 #if ENABLE_FEATURE_CLEAN_UP
2802 if (cwd != bb_msg_unknown)
2805 struct variables *cur, *tmp;
2806 for (cur = top_vars; cur; cur = tmp) {
2808 if (!cur->flg_read_only) {
2809 free((char*)cur->name);
2810 free((char*)cur->value);
2818 return opt ? opt : last_return_code;
2821 static char *insert_var_value(char *inp)
2823 int res_str_len = 0;
2826 char *p, *res_str = NULL;
2829 while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
2832 res_str = xrealloc(res_str, (res_str_len + len));
2833 strncpy((res_str + res_str_len), inp, len);
2837 p = strchr(inp, SPECIAL_VAR_SYMBOL);
2839 p1 = lookup_param(inp);
2841 len = res_str_len + strlen(p1);
2842 res_str = xrealloc(res_str, (1 + len));
2843 strcpy((res_str + res_str_len), p1);
2846 *p = SPECIAL_VAR_SYMBOL;
2851 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
2852 strcpy((res_str + res_str_len), inp);
2853 while ((p = strchr(res_str, '\n'))) {
2857 return (res_str == NULL) ? inp : res_str;
2860 static char **make_list_in(char **inp, char *name)
2863 int name_len = strlen(name);
2868 /* create list of variable values */
2869 list = xmalloc(sizeof(*list));
2870 for (i = 0; inp[i]; i++) {
2871 p3 = insert_var_value(inp[i]);
2878 p2 = strchr(p1, ' ');
2885 /* we use n + 2 in realloc for list, because we add
2886 * new element and then we will add NULL element */
2887 list = xrealloc(list, sizeof(*list) * (n + 2));
2888 list[n] = xmalloc(2 + name_len + len);
2889 strcpy(list[n], name);
2890 strcat(list[n], "=");
2891 strncat(list[n], p1, len);
2892 list[n++][name_len + len + 1] = '\0';
2895 if (p3 != inp[i]) free(p3);
2901 /* Make new string for parser */
2902 static char* make_string(char ** inp)
2909 for (n = 0; inp[n]; n++) {
2910 p = insert_var_value(inp[n]);
2911 str = xrealloc(str, (len + strlen(p)));
2918 len = strlen(str) + 3;
2919 if (p != inp[n]) free(p);