aboutsummaryrefslogtreecommitdiff
path: root/hush.c
diff options
context:
space:
mode:
Diffstat (limited to 'hush.c')
-rw-r--r--hush.c2695
1 files changed, 0 insertions, 2695 deletions
diff --git a/hush.c b/hush.c
deleted file mode 100644
index cb0e6e980..000000000
--- a/hush.c
+++ /dev/null
@@ -1,2695 +0,0 @@
1/* vi: set sw=4 ts=4: */
2/*
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.
7 *
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 *
10 * Credits:
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle.
13 * The execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash,
15 * which is Copyright (C) 2000 by Lineo, Inc., and
16 * written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
17 * That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
18 * Erik W. Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated rewrites.
20 * Other credits:
21 * simple_itoa() was lifted from boa-0.93.15
22 * b_addchr() derived from similar w_addchar function in glibc-2.2
23 * setup_redirect(), redirect_opt_num(), and big chunks of main()
24 * and many builtins derived from contributions by Erik Andersen
25 * miscellaneous bugfixes from Matt Kraai
26 *
27 * There are two big (and related) architecture differences between
28 * this parser and the lash parser. One is that this version is
29 * actually designed from the ground up to understand nearly all
30 * of the Bourne grammar. The second, consequential change is that
31 * the parser and input reader have been turned inside out. Now,
32 * the parser is in control, and asks for input as needed. The old
33 * way had the input reader in control, and it asked for parsing to
34 * take place as needed. The new way makes it much easier to properly
35 * handle the recursion implicit in the various substitutions, especially
36 * across continuation lines.
37 *
38 * Bash grammar not implemented: (how many of these were in original sh?)
39 * $@ (those sure look like weird quoting rules)
40 * $_
41 * ! negation operator for pipes
42 * &> and >& redirection of stdout+stderr
43 * Brace Expansion
44 * Tilde Expansion
45 * fancy forms of Parameter Expansion
46 * aliases
47 * Arithmetic Expansion
48 * <(list) and >(list) Process Substitution
49 * reserved words: case, esac, select, function
50 * Here Documents ( << word )
51 * Functions
52 * Major bugs:
53 * job handling woefully incomplete and buggy
54 * reserved word execution woefully incomplete and buggy
55 * to-do:
56 * port selected bugfixes from post-0.49 busybox lash - done?
57 * finish implementing reserved words: for, while, until, do, done
58 * change { and } from special chars to reserved words
59 * builtins: break, continue, eval, return, set, trap, ulimit
60 * test magic exec
61 * handle children going into background
62 * clean up recognition of null pipes
63 * check setting of global_argc and global_argv
64 * control-C handling, probably with longjmp
65 * follow IFS rules more precisely, including update semantics
66 * figure out what to do with backslash-newline
67 * explain why we use signal instead of sigaction
68 * propagate syntax errors, die on resource errors?
69 * continuation lines, both explicit and implicit - done?
70 * memory leak finding and plugging - done?
71 * more testing, especially quoting rules and redirection
72 * document how quoting rules not precisely followed for variable assignments
73 * maybe change map[] to use 2-bit entries
74 * (eventually) remove all the printf's
75 *
76 * This program is free software; you can redistribute it and/or modify
77 * it under the terms of the GNU General Public License as published by
78 * the Free Software Foundation; either version 2 of the License, or
79 * (at your option) any later version.
80 *
81 * This program is distributed in the hope that it will be useful,
82 * but WITHOUT ANY WARRANTY; without even the implied warranty of
83 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
84 * General Public License for more details.
85 *
86 * You should have received a copy of the GNU General Public License
87 * along with this program; if not, write to the Free Software
88 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
89 */
90#include <ctype.h> /* isalpha, isdigit */
91#include <unistd.h> /* getpid */
92#include <stdlib.h> /* getenv, atoi */
93#include <string.h> /* strchr */
94#include <stdio.h> /* popen etc. */
95#include <glob.h> /* glob, of course */
96#include <stdarg.h> /* va_list */
97#include <errno.h>
98#include <fcntl.h>
99#include <getopt.h> /* should be pretty obvious */
100
101#include <sys/stat.h> /* ulimit */
102#include <sys/types.h>
103#include <sys/wait.h>
104#include <signal.h>
105
106/* #include <dmalloc.h> */
107/* #define DEBUG_SHELL */
108
109#ifdef BB_VER
110#include "busybox.h"
111#include "cmdedit.h"
112#else
113#define applet_name "hush"
114#include "standalone.h"
115#define hush_main main
116#undef BB_FEATURE_SH_FANCY_PROMPT
117#endif
118
119typedef enum {
120 REDIRECT_INPUT = 1,
121 REDIRECT_OVERWRITE = 2,
122 REDIRECT_APPEND = 3,
123 REDIRECT_HEREIS = 4,
124 REDIRECT_IO = 5
125} redir_type;
126
127/* The descrip member of this structure is only used to make debugging
128 * output pretty */
129struct {int mode; int default_fd; char *descrip;} redir_table[] = {
130 { 0, 0, "()" },
131 { O_RDONLY, 0, "<" },
132 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
133 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
134 { O_RDONLY, -1, "<<" },
135 { O_RDWR, 1, "<>" }
136};
137
138typedef enum {
139 PIPE_SEQ = 1,
140 PIPE_AND = 2,
141 PIPE_OR = 3,
142 PIPE_BG = 4,
143} pipe_style;
144
145/* might eventually control execution */
146typedef enum {
147 RES_NONE = 0,
148 RES_IF = 1,
149 RES_THEN = 2,
150 RES_ELIF = 3,
151 RES_ELSE = 4,
152 RES_FI = 5,
153 RES_FOR = 6,
154 RES_WHILE = 7,
155 RES_UNTIL = 8,
156 RES_DO = 9,
157 RES_DONE = 10,
158 RES_XXXX = 11,
159 RES_SNTX = 12
160} reserved_style;
161#define FLAG_END (1<<RES_NONE)
162#define FLAG_IF (1<<RES_IF)
163#define FLAG_THEN (1<<RES_THEN)
164#define FLAG_ELIF (1<<RES_ELIF)
165#define FLAG_ELSE (1<<RES_ELSE)
166#define FLAG_FI (1<<RES_FI)
167#define FLAG_FOR (1<<RES_FOR)
168#define FLAG_WHILE (1<<RES_WHILE)
169#define FLAG_UNTIL (1<<RES_UNTIL)
170#define FLAG_DO (1<<RES_DO)
171#define FLAG_DONE (1<<RES_DONE)
172#define FLAG_START (1<<RES_XXXX)
173
174/* This holds pointers to the various results of parsing */
175struct p_context {
176 struct child_prog *child;
177 struct pipe *list_head;
178 struct pipe *pipe;
179 struct redir_struct *pending_redirect;
180 reserved_style w;
181 int old_flag; /* for figuring out valid reserved words */
182 struct p_context *stack;
183 /* How about quoting status? */
184};
185
186struct redir_struct {
187 redir_type type; /* type of redirection */
188 int fd; /* file descriptor being redirected */
189 int dup; /* -1, or file descriptor being duplicated */
190 struct redir_struct *next; /* pointer to the next redirect in the list */
191 glob_t word; /* *word.gl_pathv is the filename */
192};
193
194struct child_prog {
195 pid_t pid; /* 0 if exited */
196 char **argv; /* program name and arguments */
197 struct pipe *group; /* if non-NULL, first in group or subshell */
198 int subshell; /* flag, non-zero if group must be forked */
199 struct redir_struct *redirects; /* I/O redirections */
200 glob_t glob_result; /* result of parameter globbing */
201 int is_stopped; /* is the program currently running? */
202 struct pipe *family; /* pointer back to the child's parent pipe */
203};
204
205struct pipe {
206 int jobid; /* job number */
207 int num_progs; /* total number of programs in job */
208 int running_progs; /* number of programs running */
209 char *text; /* name of job */
210 char *cmdbuf; /* buffer various argv's point into */
211 pid_t pgrp; /* process group ID for the job */
212 struct child_prog *progs; /* array of commands in pipe */
213 struct pipe *next; /* to track background commands */
214 int stopped_progs; /* number of programs alive, but stopped */
215 int job_context; /* bitmask defining current context */
216 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
217 reserved_style r_mode; /* supports if, for, while, until */
218};
219
220struct close_me {
221 int fd;
222 struct close_me *next;
223};
224
225struct variables {
226 char *name;
227 char *value;
228 int flg_export;
229 int flg_read_only;
230 struct variables *next;
231};
232
233/* globals, connect us to the outside world
234 * the first three support $?, $#, and $1 */
235char **global_argv;
236unsigned int global_argc;
237unsigned int last_return_code;
238extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
239
240/* "globals" within this file */
241static char *ifs;
242static char map[256];
243static int fake_mode;
244static int interactive;
245static struct close_me *close_me_head;
246static const char *cwd;
247static struct pipe *job_list;
248static unsigned int last_bg_pid;
249static unsigned int last_jobid;
250static unsigned int shell_terminal;
251static char *PS1;
252static char *PS2;
253struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
254struct variables *top_vars = &shell_ver;
255
256
257#define B_CHUNK (100)
258#define B_NOSPAC 1
259
260typedef struct {
261 char *data;
262 int length;
263 int maxlen;
264 int quote;
265 int nonnull;
266} o_string;
267#define NULL_O_STRING {NULL,0,0,0,0}
268/* used for initialization:
269 o_string foo = NULL_O_STRING; */
270
271/* I can almost use ordinary FILE *. Is open_memstream() universally
272 * available? Where is it documented? */
273struct in_str {
274 const char *p;
275 char peek_buf[2];
276 int __promptme;
277 int promptmode;
278 FILE *file;
279 int (*get) (struct in_str *);
280 int (*peek) (struct in_str *);
281};
282#define b_getch(input) ((input)->get(input))
283#define b_peek(input) ((input)->peek(input))
284
285#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
286
287struct built_in_command {
288 char *cmd; /* name */
289 char *descr; /* description */
290 int (*function) (struct child_prog *); /* function ptr */
291};
292
293/* belongs in busybox.h */
294static inline int max(int a, int b) {
295 return (a>b)?a:b;
296}
297
298/* This should be in utility.c */
299#ifdef DEBUG_SHELL
300static void debug_printf(const char *format, ...)
301{
302 va_list args;
303 va_start(args, format);
304 vfprintf(stderr, format, args);
305 va_end(args);
306}
307#else
308static inline void debug_printf(const char *format, ...) { }
309#endif
310#define final_printf debug_printf
311
312static void __syntax(char *file, int line) {
313 error_msg("syntax error %s:%d", file, line);
314}
315#define syntax() __syntax(__FILE__, __LINE__)
316
317/* Index of subroutines: */
318/* function prototypes for builtins */
319static int builtin_cd(struct child_prog *child);
320static int builtin_env(struct child_prog *child);
321static int builtin_exec(struct child_prog *child);
322static int builtin_exit(struct child_prog *child);
323static int builtin_export(struct child_prog *child);
324static int builtin_fg_bg(struct child_prog *child);
325static int builtin_help(struct child_prog *child);
326static int builtin_jobs(struct child_prog *child);
327static int builtin_pwd(struct child_prog *child);
328static int builtin_read(struct child_prog *child);
329static int builtin_set(struct child_prog *child);
330static int builtin_shift(struct child_prog *child);
331static int builtin_source(struct child_prog *child);
332static int builtin_umask(struct child_prog *child);
333static int builtin_unset(struct child_prog *child);
334static int builtin_not_written(struct child_prog *child);
335/* o_string manipulation: */
336static int b_check_space(o_string *o, int len);
337static int b_addchr(o_string *o, int ch);
338static void b_reset(o_string *o);
339static int b_addqchr(o_string *o, int ch, int quote);
340static int b_adduint(o_string *o, unsigned int i);
341/* in_str manipulations: */
342static int static_get(struct in_str *i);
343static int static_peek(struct in_str *i);
344static int file_get(struct in_str *i);
345static int file_peek(struct in_str *i);
346static void setup_file_in_str(struct in_str *i, FILE *f);
347static void setup_string_in_str(struct in_str *i, const char *s);
348/* close_me manipulations: */
349static void mark_open(int fd);
350static void mark_closed(int fd);
351static void close_all();
352/* "run" the final data structures: */
353static char *indenter(int i);
354static int free_pipe_list(struct pipe *head, int indent);
355static int free_pipe(struct pipe *pi, int indent);
356/* really run the final data structures: */
357static int setup_redirects(struct child_prog *prog, int squirrel[]);
358static int run_list_real(struct pipe *pi);
359static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
360static int run_pipe_real(struct pipe *pi);
361/* extended glob support: */
362static int globhack(const char *src, int flags, glob_t *pglob);
363static int glob_needed(const char *s);
364static int xglob(o_string *dest, int flags, glob_t *pglob);
365/* variable assignment: */
366static int is_assignment(const char *s);
367/* data structure manipulation: */
368static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
369static void initialize_context(struct p_context *ctx);
370static int done_word(o_string *dest, struct p_context *ctx);
371static int done_command(struct p_context *ctx);
372static int done_pipe(struct p_context *ctx, pipe_style type);
373/* primary string parsing: */
374static int redirect_dup_num(struct in_str *input);
375static int redirect_opt_num(o_string *o);
376static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
377static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
378static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src);
379static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
380static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
381static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
382/* setup: */
383static int parse_stream_outer(struct in_str *inp);
384static int parse_string_outer(const char *s);
385static int parse_file_outer(FILE *f);
386/* job management: */
387static int checkjobs(struct pipe* fg_pipe);
388static void insert_bg_job(struct pipe *pi);
389static void remove_bg_job(struct pipe *pi);
390/* local variable support */
391static char *get_local_var(const char *var);
392static void unset_local_var(const char *name);
393static int set_local_var(const char *s, int flg_export);
394
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 can not.
399 * For example, 'unset foo | whatever' will parse and run, but foo will
400 * still be set at the end. */
401static 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_not_written},
408 {"exec", "Exec command, replacing this shell with the exec'd process",
409 builtin_exec},
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},
425 {NULL, NULL, NULL}
426};
427
428static const char *set_cwd(void)
429{
430 if(cwd==unknown)
431 cwd = NULL; /* xgetcwd(arg) called free(arg) */
432 cwd = xgetcwd((char *)cwd);
433 if (!cwd)
434 cwd = unknown;
435 return cwd;
436}
437
438
439/* built-in 'cd <path>' handler */
440static int builtin_cd(struct child_prog *child)
441{
442 char *newdir;
443 if (child->argv[1] == NULL)
444 newdir = getenv("HOME");
445 else
446 newdir = child->argv[1];
447 if (chdir(newdir)) {
448 printf("cd: %s: %s\n", newdir, strerror(errno));
449 return EXIT_FAILURE;
450 }
451 set_cwd();
452 return EXIT_SUCCESS;
453}
454
455/* built-in 'env' handler */
456static int builtin_env(struct child_prog *dummy)
457{
458 char **e = environ;
459 if (e == NULL) return EXIT_FAILURE;
460 for (; *e; e++) {
461 puts(*e);
462 }
463 return EXIT_SUCCESS;
464}
465
466/* built-in 'exec' handler */
467static int builtin_exec(struct child_prog *child)
468{
469 if (child->argv[1] == NULL)
470 return EXIT_SUCCESS; /* Really? */
471 child->argv++;
472 pseudo_exec(child);
473 /* never returns */
474}
475
476/* built-in 'exit' handler */
477static int builtin_exit(struct child_prog *child)
478{
479 if (child->argv[1] == NULL)
480 exit(last_return_code);
481 exit (atoi(child->argv[1]));
482}
483
484/* built-in 'export VAR=value' handler */
485static int builtin_export(struct child_prog *child)
486{
487 int res = 0;
488 char *name = child->argv[1];
489
490 if (name == NULL) {
491 return (builtin_env(child));
492 }
493
494 name = strdup(name);
495
496 if(name) {
497 char *value = strchr(name, '=');
498
499 if (!value) {
500 char *tmp;
501 /* They are exporting something without an =VALUE */
502
503 value = get_local_var(name);
504 if (value) {
505 size_t ln = strlen(name);
506
507 tmp = realloc(name, ln+strlen(value)+2);
508 if(tmp==NULL)
509 res = -1;
510 else {
511 sprintf(tmp+ln, "=%s", value);
512 name = tmp;
513 }
514 } else {
515 /* bash does not return an error when trying to export
516 * an undefined variable. Do likewise. */
517 res = 1;
518 }
519 }
520 }
521 if (res<0)
522 perror_msg("export");
523 else if(res==0)
524 res = set_local_var(name, 1);
525 else
526 res = 0;
527 free(name);
528 return res;
529}
530
531/* built-in 'fg' and 'bg' handler */
532static int builtin_fg_bg(struct child_prog *child)
533{
534 int i, jobnum;
535 struct pipe *pi=NULL;
536
537 if (!interactive)
538 return EXIT_FAILURE;
539 /* If they gave us no args, assume they want the last backgrounded task */
540 if (!child->argv[1]) {
541 for (pi = job_list; pi; pi = pi->next) {
542 if (pi->jobid == last_jobid) {
543 break;
544 }
545 }
546 if (!pi) {
547 error_msg("%s: no current job", child->argv[0]);
548 return EXIT_FAILURE;
549 }
550 } else {
551 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
552 error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
553 return EXIT_FAILURE;
554 }
555 for (pi = job_list; pi; pi = pi->next) {
556 if (pi->jobid == jobnum) {
557 break;
558 }
559 }
560 if (!pi) {
561 error_msg("%s: %d: no such job", child->argv[0], jobnum);
562 return EXIT_FAILURE;
563 }
564 }
565
566 if (*child->argv[0] == 'f') {
567 /* Put the job into the foreground. */
568 tcsetpgrp(shell_terminal, pi->pgrp);
569 }
570
571 /* Restart the processes in the job */
572 for (i = 0; i < pi->num_progs; i++)
573 pi->progs[i].is_stopped = 0;
574
575 if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
576 if (i == ESRCH) {
577 remove_bg_job(pi);
578 } else {
579 perror_msg("kill (SIGCONT)");
580 }
581 }
582
583 pi->stopped_progs = 0;
584 return EXIT_SUCCESS;
585}
586
587/* built-in 'help' handler */
588static int builtin_help(struct child_prog *dummy)
589{
590 struct built_in_command *x;
591
592 printf("\nBuilt-in commands:\n");
593 printf("-------------------\n");
594 for (x = bltins; x->cmd; x++) {
595 if (x->descr==NULL)
596 continue;
597 printf("%s\t%s\n", x->cmd, x->descr);
598 }
599 printf("\n\n");
600 return EXIT_SUCCESS;
601}
602
603/* built-in 'jobs' handler */
604static int builtin_jobs(struct child_prog *child)
605{
606 struct pipe *job;
607 char *status_string;
608
609 for (job = job_list; job; job = job->next) {
610 if (job->running_progs == job->stopped_progs)
611 status_string = "Stopped";
612 else
613 status_string = "Running";
614
615 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
616 }
617 return EXIT_SUCCESS;
618}
619
620
621/* built-in 'pwd' handler */
622static int builtin_pwd(struct child_prog *dummy)
623{
624 puts(set_cwd());
625 return EXIT_SUCCESS;
626}
627
628/* built-in 'read VAR' handler */
629static int builtin_read(struct child_prog *child)
630{
631 int res;
632
633 if (child->argv[1]) {
634 char string[BUFSIZ];
635 char *var = 0;
636
637 string[0] = 0; /* In case stdin has only EOF */
638 /* read string */
639 fgets(string, sizeof(string), stdin);
640 chomp(string);
641 var = malloc(strlen(child->argv[1])+strlen(string)+2);
642 if(var) {
643 sprintf(var, "%s=%s", child->argv[1], string);
644 res = set_local_var(var, 0);
645 } else
646 res = -1;
647 if (res)
648 fprintf(stderr, "read: %m\n");
649 free(var); /* So not move up to avoid breaking errno */
650 return res;
651 } else {
652 do res=getchar(); while(res!='\n' && res!=EOF);
653 return 0;
654 }
655}
656
657/* built-in 'set VAR=value' handler */
658static int builtin_set(struct child_prog *child)
659{
660 char *temp = child->argv[1];
661 struct variables *e;
662
663 if (temp == NULL)
664 for(e = top_vars; e; e=e->next)
665 printf("%s=%s\n", e->name, e->value);
666 else
667 set_local_var(temp, 0);
668
669 return EXIT_SUCCESS;
670}
671
672
673/* Built-in 'shift' handler */
674static int builtin_shift(struct child_prog *child)
675{
676 int n=1;
677 if (child->argv[1]) {
678 n=atoi(child->argv[1]);
679 }
680 if (n>=0 && n<global_argc) {
681 /* XXX This probably breaks $0 */
682 global_argc -= n;
683 global_argv += n;
684 return EXIT_SUCCESS;
685 } else {
686 return EXIT_FAILURE;
687 }
688}
689
690/* Built-in '.' handler (read-in and execute commands from file) */
691static int builtin_source(struct child_prog *child)
692{
693 FILE *input;
694 int status;
695
696 if (child->argv[1] == NULL)
697 return EXIT_FAILURE;
698
699 /* XXX search through $PATH is missing */
700 input = fopen(child->argv[1], "r");
701 if (!input) {
702 error_msg("Couldn't open file '%s'", child->argv[1]);
703 return EXIT_FAILURE;
704 }
705
706 /* Now run the file */
707 /* XXX argv and argc are broken; need to save old global_argv
708 * (pointer only is OK!) on this stack frame,
709 * set global_argv=child->argv+1, recurse, and restore. */
710 mark_open(fileno(input));
711 status = parse_file_outer(input);
712 mark_closed(fileno(input));
713 fclose(input);
714 return (status);
715}
716
717static int builtin_umask(struct child_prog *child)
718{
719 mode_t new_umask;
720 const char *arg = child->argv[1];
721 char *end;
722 if (arg) {
723 new_umask=strtoul(arg, &end, 8);
724 if (*end!='\0' || end == arg) {
725 return EXIT_FAILURE;
726 }
727 } else {
728 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
729 }
730 umask(new_umask);
731 return EXIT_SUCCESS;
732}
733
734/* built-in 'unset VAR' handler */
735static int builtin_unset(struct child_prog *child)
736{
737 /* bash returned already true */
738 unset_local_var(child->argv[1]);
739 return EXIT_SUCCESS;
740}
741
742static int builtin_not_written(struct child_prog *child)
743{
744 printf("builtin_%s not written\n",child->argv[0]);
745 return EXIT_FAILURE;
746}
747
748static int b_check_space(o_string *o, int len)
749{
750 /* It would be easy to drop a more restrictive policy
751 * in here, such as setting a maximum string length */
752 if (o->length + len > o->maxlen) {
753 char *old_data = o->data;
754 /* assert (data == NULL || o->maxlen != 0); */
755 o->maxlen += max(2*len, B_CHUNK);
756 o->data = realloc(o->data, 1 + o->maxlen);
757 if (o->data == NULL) {
758 free(old_data);
759 }
760 }
761 return o->data == NULL;
762}
763
764static int b_addchr(o_string *o, int ch)
765{
766 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
767 if (b_check_space(o, 1)) return B_NOSPAC;
768 o->data[o->length] = ch;
769 o->length++;
770 o->data[o->length] = '\0';
771 return 0;
772}
773
774static void b_reset(o_string *o)
775{
776 o->length = 0;
777 o->nonnull = 0;
778 if (o->data != NULL) *o->data = '\0';
779}
780
781static void b_free(o_string *o)
782{
783 b_reset(o);
784 if (o->data != NULL) free(o->data);
785 o->data = NULL;
786 o->maxlen = 0;
787}
788
789/* My analysis of quoting semantics tells me that state information
790 * is associated with a destination, not a source.
791 */
792static int b_addqchr(o_string *o, int ch, int quote)
793{
794 if (quote && strchr("*?[\\",ch)) {
795 int rc;
796 rc = b_addchr(o, '\\');
797 if (rc) return rc;
798 }
799 return b_addchr(o, ch);
800}
801
802/* belongs in utility.c */
803char *simple_itoa(unsigned int i)
804{
805 /* 21 digits plus null terminator, good for 64-bit or smaller ints */
806 static char local[22];
807 char *p = &local[21];
808 *p-- = '\0';
809 do {
810 *p-- = '0' + i % 10;
811 i /= 10;
812 } while (i > 0);
813 return p + 1;
814}
815
816static int b_adduint(o_string *o, unsigned int i)
817{
818 int r;
819 char *p = simple_itoa(i);
820 /* no escape checking necessary */
821 do r=b_addchr(o, *p++); while (r==0 && *p);
822 return r;
823}
824
825static int static_get(struct in_str *i)
826{
827 int ch=*i->p++;
828 if (ch=='\0') return EOF;
829 return ch;
830}
831
832static int static_peek(struct in_str *i)
833{
834 return *i->p;
835}
836
837static inline void cmdedit_set_initial_prompt(void)
838{
839#ifndef BB_FEATURE_SH_FANCY_PROMPT
840 PS1 = NULL;
841#else
842 PS1 = getenv("PS1");
843 if(PS1==0)
844 PS1 = "\\w \\$ ";
845#endif
846}
847
848static inline void setup_prompt_string(int promptmode, char **prompt_str)
849{
850 debug_printf("setup_prompt_string %d ",promptmode);
851#ifndef BB_FEATURE_SH_FANCY_PROMPT
852 /* Set up the prompt */
853 if (promptmode == 1) {
854 if (PS1)
855 free(PS1);
856 PS1=xmalloc(strlen(cwd)+4);
857 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
858 *prompt_str = PS1;
859 } else {
860 *prompt_str = PS2;
861 }
862#else
863 *prompt_str = (promptmode==1)? PS1 : PS2;
864#endif
865 debug_printf("result %s\n",*prompt_str);
866}
867
868static void get_user_input(struct in_str *i)
869{
870 char *prompt_str;
871 static char the_command[BUFSIZ];
872
873 setup_prompt_string(i->promptmode, &prompt_str);
874#ifdef BB_FEATURE_COMMAND_EDITING
875 /*
876 ** enable command line editing only while a command line
877 ** is actually being read; otherwise, we'll end up bequeathing
878 ** atexit() handlers and other unwanted stuff to our
879 ** child processes (rob@sysgo.de)
880 */
881 cmdedit_read_input(prompt_str, the_command);
882#else
883 fputs(prompt_str, stdout);
884 fflush(stdout);
885 the_command[0]=fgetc(i->file);
886 the_command[1]='\0';
887#endif
888 fflush(stdout);
889 i->p = the_command;
890}
891
892/* This is the magic location that prints prompts
893 * and gets data back from the user */
894static int file_get(struct in_str *i)
895{
896 int ch;
897
898 ch = 0;
899 /* If there is data waiting, eat it up */
900 if (i->p && *i->p) {
901 ch=*i->p++;
902 } else {
903 /* need to double check i->file because we might be doing something
904 * more complicated by now, like sourcing or substituting. */
905 if (i->__promptme && interactive && i->file == stdin) {
906 while(! i->p || (interactive && strlen(i->p)==0) ) {
907 get_user_input(i);
908 }
909 i->promptmode=2;
910 i->__promptme = 0;
911 if (i->p && *i->p) {
912 ch=*i->p++;
913 }
914 } else {
915 ch = fgetc(i->file);
916 }
917
918 debug_printf("b_getch: got a %d\n", ch);
919 }
920 if (ch == '\n') i->__promptme=1;
921 return ch;
922}
923
924/* All the callers guarantee this routine will never be
925 * used right after a newline, so prompting is not needed.
926 */
927static int file_peek(struct in_str *i)
928{
929 if (i->p && *i->p) {
930 return *i->p;
931 } else {
932 i->peek_buf[0] = fgetc(i->file);
933 i->peek_buf[1] = '\0';
934 i->p = i->peek_buf;
935 debug_printf("b_peek: got a %d\n", *i->p);
936 return *i->p;
937 }
938}
939
940static void setup_file_in_str(struct in_str *i, FILE *f)
941{
942 i->peek = file_peek;
943 i->get = file_get;
944 i->__promptme=1;
945 i->promptmode=1;
946 i->file = f;
947 i->p = NULL;
948}
949
950static void setup_string_in_str(struct in_str *i, const char *s)
951{
952 i->peek = static_peek;
953 i->get = static_get;
954 i->__promptme=1;
955 i->promptmode=1;
956 i->p = s;
957}
958
959static void mark_open(int fd)
960{
961 struct close_me *new = xmalloc(sizeof(struct close_me));
962 new->fd = fd;
963 new->next = close_me_head;
964 close_me_head = new;
965}
966
967static void mark_closed(int fd)
968{
969 struct close_me *tmp;
970 if (close_me_head == NULL || close_me_head->fd != fd)
971 error_msg_and_die("corrupt close_me");
972 tmp = close_me_head;
973 close_me_head = close_me_head->next;
974 free(tmp);
975}
976
977static void close_all()
978{
979 struct close_me *c;
980 for (c=close_me_head; c; c=c->next) {
981 close(c->fd);
982 }
983 close_me_head = NULL;
984}
985
986/* squirrel != NULL means we squirrel away copies of stdin, stdout,
987 * and stderr if they are redirected. */
988static int setup_redirects(struct child_prog *prog, int squirrel[])
989{
990 int openfd, mode;
991 struct redir_struct *redir;
992
993 for (redir=prog->redirects; redir; redir=redir->next) {
994 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
995 /* something went wrong in the parse. Pretend it didn't happen */
996 continue;
997 }
998 if (redir->dup == -1) {
999 mode=redir_table[redir->type].mode;
1000 openfd = open(redir->word.gl_pathv[0], mode, 0666);
1001 if (openfd < 0) {
1002 /* this could get lost if stderr has been redirected, but
1003 bash and ash both lose it as well (though zsh doesn't!) */
1004 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1005 return 1;
1006 }
1007 } else {
1008 openfd = redir->dup;
1009 }
1010
1011 if (openfd != redir->fd) {
1012 if (squirrel && redir->fd < 3) {
1013 squirrel[redir->fd] = dup(redir->fd);
1014 }
1015 if (openfd == -3) {
1016 close(openfd);
1017 } else {
1018 dup2(openfd, redir->fd);
1019 if (redir->dup == -1)
1020 close (openfd);
1021 }
1022 }
1023 }
1024 return 0;
1025}
1026
1027static void restore_redirects(int squirrel[])
1028{
1029 int i, fd;
1030 for (i=0; i<3; i++) {
1031 fd = squirrel[i];
1032 if (fd != -1) {
1033 /* No error checking. I sure wouldn't know what
1034 * to do with an error if I found one! */
1035 dup2(fd, i);
1036 close(fd);
1037 }
1038 }
1039}
1040
1041/* never returns */
1042/* XXX no exit() here. If you don't exec, use _exit instead.
1043 * The at_exit handlers apparently confuse the calling process,
1044 * in particular stdin handling. Not sure why? */
1045static void pseudo_exec(struct child_prog *child)
1046{
1047 int i, rcode;
1048 struct built_in_command *x;
1049 if (child->argv) {
1050 for (i=0; is_assignment(child->argv[i]); i++) {
1051 debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1052 putenv(strdup(child->argv[i]));
1053 }
1054 child->argv+=i; /* XXX this hack isn't so horrible, since we are about
1055 to exit, and therefore don't need to keep data
1056 structures consistent for free() use. */
1057 /* If a variable is assigned in a forest, and nobody listens,
1058 * was it ever really set?
1059 */
1060 if (child->argv[0] == NULL) {
1061 _exit(EXIT_SUCCESS);
1062 }
1063
1064 /*
1065 * Check if the command matches any of the builtins.
1066 * Depending on context, this might be redundant. But it's
1067 * easier to waste a few CPU cycles than it is to figure out
1068 * if this is one of those cases.
1069 */
1070 for (x = bltins; x->cmd; x++) {
1071 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1072 debug_printf("builtin exec %s\n", child->argv[0]);
1073 rcode = x->function(child);
1074 fflush(stdout);
1075 _exit(rcode);
1076 }
1077 }
1078
1079 /* Check if the command matches any busybox internal commands
1080 * ("applets") here.
1081 * FIXME: This feature is not 100% safe, since
1082 * BusyBox is not fully reentrant, so we have no guarantee the things
1083 * from the .bss are still zeroed, or that things from .data are still
1084 * at their defaults. We could exec ourself from /proc/self/exe, but I
1085 * really dislike relying on /proc for things. We could exec ourself
1086 * from global_argv[0], but if we are in a chroot, we may not be able
1087 * to find ourself... */
1088#ifdef BB_FEATURE_SH_STANDALONE_SHELL
1089 {
1090 int argc_l;
1091 char** argv_l=child->argv;
1092 char *name = child->argv[0];
1093
1094#ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1095 /* Following discussions from November 2000 on the busybox mailing
1096 * list, the default configuration, (without
1097 * get_last_path_component()) lets the user force use of an
1098 * external command by specifying the full (with slashes) filename.
1099 * If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then applets
1100 * _aways_ override external commands, so if you want to run
1101 * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1102 * filesystem and is _not_ busybox. Some systems may want this,
1103 * most do not. */
1104 name = get_last_path_component(name);
1105#endif
1106 /* Count argc for use in a second... */
1107 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1108 optind = 1;
1109 debug_printf("running applet %s\n", name);
1110 run_applet_by_name(name, argc_l, child->argv);
1111 }
1112#endif
1113 debug_printf("exec of %s\n",child->argv[0]);
1114 execvp(child->argv[0],child->argv);
1115 perror_msg("couldn't exec: %s",child->argv[0]);
1116 _exit(1);
1117 } else if (child->group) {
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 */
1123 _exit(rcode);
1124 } else {
1125 /* Can happen. See what bash does with ">foo" by itself. */
1126 debug_printf("trying to pseudo_exec null command\n");
1127 _exit(EXIT_SUCCESS);
1128 }
1129}
1130
1131static void insert_bg_job(struct pipe *pi)
1132{
1133 struct pipe *thejob;
1134
1135 /* Linear search for the ID of the job to use */
1136 pi->jobid = 1;
1137 for (thejob = job_list; thejob; thejob = thejob->next)
1138 if (thejob->jobid >= pi->jobid)
1139 pi->jobid = thejob->jobid + 1;
1140
1141 /* add thejob to the list of running jobs */
1142 if (!job_list) {
1143 thejob = job_list = xmalloc(sizeof(*thejob));
1144 } else {
1145 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1146 thejob->next = xmalloc(sizeof(*thejob));
1147 thejob = thejob->next;
1148 }
1149
1150 /* physically copy the struct job */
1151 memcpy(thejob, pi, sizeof(struct pipe));
1152 thejob->next = NULL;
1153 thejob->running_progs = thejob->num_progs;
1154 thejob->stopped_progs = 0;
1155 thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1156
1157 //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
1158 {
1159 char *bar=thejob->text;
1160 char **foo=pi->progs[0].argv;
1161 while(foo && *foo) {
1162 bar += sprintf(bar, "%s ", *foo++);
1163 }
1164 }
1165
1166 /* we don't wait for background thejobs to return -- append it
1167 to the list of backgrounded thejobs and leave it alone */
1168 printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1169 last_bg_pid = thejob->progs[0].pid;
1170 last_jobid = thejob->jobid;
1171}
1172
1173/* remove a backgrounded job */
1174static void remove_bg_job(struct pipe *pi)
1175{
1176 struct pipe *prev_pipe;
1177
1178 if (pi == job_list) {
1179 job_list = pi->next;
1180 } else {
1181 prev_pipe = job_list;
1182 while (prev_pipe->next != pi)
1183 prev_pipe = prev_pipe->next;
1184 prev_pipe->next = pi->next;
1185 }
1186 if (job_list)
1187 last_jobid = job_list->jobid;
1188 else
1189 last_jobid = 0;
1190
1191 pi->stopped_progs = 0;
1192 free_pipe(pi, 0);
1193 free(pi);
1194}
1195
1196/* Checks to see if any processes have exited -- if they
1197 have, figure out why and see if a job has completed */
1198static int checkjobs(struct pipe* fg_pipe)
1199{
1200 int attributes;
1201 int status;
1202 int prognum = 0;
1203 struct pipe *pi;
1204 pid_t childpid;
1205
1206 attributes = WUNTRACED;
1207 if (fg_pipe==NULL) {
1208 attributes |= WNOHANG;
1209 }
1210
1211 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1212 if (fg_pipe) {
1213 int i, rcode = 0;
1214 for (i=0; i < fg_pipe->num_progs; i++) {
1215 if (fg_pipe->progs[i].pid == childpid) {
1216 if (i==fg_pipe->num_progs-1)
1217 rcode=WEXITSTATUS(status);
1218 (fg_pipe->num_progs)--;
1219 return(rcode);
1220 }
1221 }
1222 }
1223
1224 for (pi = job_list; pi; pi = pi->next) {
1225 prognum = 0;
1226 while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1227 prognum++;
1228 }
1229 if (prognum < pi->num_progs)
1230 break;
1231 }
1232
1233 if(pi==NULL) {
1234 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1235 continue;
1236 }
1237
1238 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1239 /* child exited */
1240 pi->running_progs--;
1241 pi->progs[prognum].pid = 0;
1242
1243 if (!pi->running_progs) {
1244 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1245 remove_bg_job(pi);
1246 }
1247 } else {
1248 /* child stopped */
1249 pi->stopped_progs++;
1250 pi->progs[prognum].is_stopped = 1;
1251
1252#if 0
1253 /* Printing this stuff is a pain, since it tends to
1254 * overwrite the prompt an inconveinient moments. So
1255 * don't do that. */
1256 if (pi->stopped_progs == pi->num_progs) {
1257 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1258 }
1259#endif
1260 }
1261 }
1262
1263 if (childpid == -1 && errno != ECHILD)
1264 perror_msg("waitpid");
1265
1266 /* move the shell to the foreground */
1267 //if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
1268 // perror_msg("tcsetpgrp-2");
1269 return -1;
1270}
1271
1272/* Figure out our controlling tty, checking in order stderr,
1273 * stdin, and stdout. If check_pgrp is set, also check that
1274 * we belong to the foreground process group associated with
1275 * that tty. The value of shell_terminal is needed in order to call
1276 * tcsetpgrp(shell_terminal, ...); */
1277void controlling_tty(int check_pgrp)
1278{
1279 pid_t curpgrp;
1280
1281 if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1282 && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1283 && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1284 goto shell_terminal_error;
1285
1286 if (check_pgrp && curpgrp != getpgid(0))
1287 goto shell_terminal_error;
1288
1289 return;
1290
1291shell_terminal_error:
1292 shell_terminal = -1;
1293 return;
1294}
1295
1296/* run_pipe_real() starts all the jobs, but doesn't wait for anything
1297 * to finish. See checkjobs().
1298 *
1299 * return code is normally -1, when the caller has to wait for children
1300 * to finish to determine the exit status of the pipe. If the pipe
1301 * is a simple builtin command, however, the action is done by the
1302 * time run_pipe_real returns, and the exit code is provided as the
1303 * return value.
1304 *
1305 * The input of the pipe is always stdin, the output is always
1306 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1307 * because it tries to avoid running the command substitution in
1308 * subshell, when that is in fact necessary. The subshell process
1309 * now has its stdout directed to the input of the appropriate pipe,
1310 * so this routine is noticeably simpler.
1311 */
1312static int run_pipe_real(struct pipe *pi)
1313{
1314 int i;
1315 int nextin, nextout;
1316 int pipefds[2]; /* pipefds[0] is for reading */
1317 struct child_prog *child;
1318 struct built_in_command *x;
1319
1320 nextin = 0;
1321 pi->pgrp = -1;
1322
1323 /* Check if this is a simple builtin (not part of a pipe).
1324 * Builtins within pipes have to fork anyway, and are handled in
1325 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1326 */
1327 if (pi->num_progs == 1) child = & (pi->progs[0]);
1328 if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1329 int squirrel[] = {-1, -1, -1};
1330 int rcode;
1331 debug_printf("non-subshell grouping\n");
1332 setup_redirects(child, squirrel);
1333 /* XXX could we merge code with following builtin case,
1334 * by creating a pseudo builtin that calls run_list_real? */
1335 rcode = run_list_real(child->group);
1336 restore_redirects(squirrel);
1337 return rcode;
1338 } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1339 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1340 if (i!=0 && child->argv[i]==NULL) {
1341 /* assignments, but no command: set the local environment */
1342 for (i=0; child->argv[i]!=NULL; i++) {
1343
1344 /* Ok, this case is tricky. We have to decide if this is a
1345 * local variable, or an already exported variable. If it is
1346 * already exported, we have to export the new value. If it is
1347 * not exported, we need only set this as a local variable.
1348 * This junk is all to decide whether or not to export this
1349 * variable. */
1350 int export_me=0;
1351 char *name, *value;
1352 name = xstrdup(child->argv[i]);
1353 debug_printf("Local environment set: %s\n", name);
1354 value = strchr(name, '=');
1355 if (value)
1356 *value=0;
1357 if ( get_local_var(name)) {
1358 export_me=1;
1359 }
1360 free(name);
1361 set_local_var(child->argv[i], export_me);
1362 }
1363 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1364 }
1365 for (x = bltins; x->cmd; x++) {
1366 if (strcmp(child->argv[i], x->cmd) == 0 ) {
1367 int squirrel[] = {-1, -1, -1};
1368 int rcode;
1369 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1370 debug_printf("magic exec\n");
1371 setup_redirects(child,NULL);
1372 return EXIT_SUCCESS;
1373 }
1374 debug_printf("builtin inline %s\n", child->argv[0]);
1375 /* XXX setup_redirects acts on file descriptors, not FILEs.
1376 * This is perfect for work that comes after exec().
1377 * Is it really safe for inline use? Experimentally,
1378 * things seem to work with glibc. */
1379 setup_redirects(child, squirrel);
1380 for (i=0; is_assignment(child->argv[i]); i++) {
1381 putenv(strdup(child->argv[i]));
1382 }
1383 child->argv+=i; /* XXX horrible hack */
1384 rcode = x->function(child);
1385 child->argv-=i; /* XXX restore hack so free() can work right */
1386 restore_redirects(squirrel);
1387 return rcode;
1388 }
1389 }
1390 }
1391
1392 for (i = 0; i < pi->num_progs; i++) {
1393 child = & (pi->progs[i]);
1394
1395 /* pipes are inserted between pairs of commands */
1396 if ((i + 1) < pi->num_progs) {
1397 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1398 nextout = pipefds[1];
1399 } else {
1400 nextout=1;
1401 pipefds[0] = -1;
1402 }
1403
1404 /* XXX test for failed fork()? */
1405 if (!(child->pid = fork())) {
1406 /* Set the handling for job control signals back to the default. */
1407 signal(SIGINT, SIG_DFL);
1408 signal(SIGQUIT, SIG_DFL);
1409 signal(SIGTERM, SIG_DFL);
1410 signal(SIGTSTP, SIG_DFL);
1411 signal(SIGTTIN, SIG_DFL);
1412 signal(SIGTTOU, SIG_DFL);
1413 signal(SIGCHLD, SIG_DFL);
1414
1415 close_all();
1416
1417 if (nextin != 0) {
1418 dup2(nextin, 0);
1419 close(nextin);
1420 }
1421 if (nextout != 1) {
1422 dup2(nextout, 1);
1423 close(nextout);
1424 }
1425 if (pipefds[0]!=-1) {
1426 close(pipefds[0]); /* opposite end of our output pipe */
1427 }
1428
1429 /* Like bash, explicit redirects override pipes,
1430 * and the pipe fd is available for dup'ing. */
1431 setup_redirects(child,NULL);
1432
1433 if (interactive && pi->followup!=PIPE_BG) {
1434 /* If we (the child) win the race, put ourselves in the process
1435 * group whose leader is the first process in this pipe. */
1436 if (pi->pgrp < 0) {
1437 pi->pgrp = getpid();
1438 }
1439 if (setpgid(0, pi->pgrp) == 0) {
1440 tcsetpgrp(2, pi->pgrp);
1441 }
1442 }
1443
1444 pseudo_exec(child);
1445 }
1446
1447
1448 /* put our child in the process group whose leader is the
1449 first process in this pipe */
1450 if (pi->pgrp < 0) {
1451 pi->pgrp = child->pid;
1452 }
1453 /* Don't check for errors. The child may be dead already,
1454 * in which case setpgid returns error code EACCES. */
1455 setpgid(child->pid, pi->pgrp);
1456
1457 if (nextin != 0)
1458 close(nextin);
1459 if (nextout != 1)
1460 close(nextout);
1461
1462 /* If there isn't another process, nextin is garbage
1463 but it doesn't matter */
1464 nextin = pipefds[0];
1465 }
1466 return -1;
1467}
1468
1469static int run_list_real(struct pipe *pi)
1470{
1471 int rcode=0;
1472 int if_code=0, next_if_code=0; /* need double-buffer to handle elif */
1473 reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1474 for (;pi;pi=pi->next) {
1475 rmode = pi->r_mode;
1476 debug_printf("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
1477 if (rmode == skip_more_in_this_rmode) continue;
1478 skip_more_in_this_rmode = RES_XXXX;
1479 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1480 if (rmode == RES_THEN && if_code) continue;
1481 if (rmode == RES_ELSE && !if_code) continue;
1482 if (rmode == RES_ELIF && !if_code) continue;
1483 if (pi->num_progs == 0) continue;
1484 rcode = run_pipe_real(pi);
1485 debug_printf("run_pipe_real returned %d\n",rcode);
1486 if (rcode!=-1) {
1487 /* We only ran a builtin: rcode was set by the return value
1488 * of run_pipe_real(), and we don't need to wait for anything. */
1489 } else if (pi->followup==PIPE_BG) {
1490 /* XXX check bash's behavior with nontrivial pipes */
1491 /* XXX compute jobid */
1492 /* XXX what does bash do with attempts to background builtins? */
1493 insert_bg_job(pi);
1494 rcode = EXIT_SUCCESS;
1495 } else {
1496 if (interactive) {
1497 /* move the new process group into the foreground */
1498 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1499 perror_msg("tcsetpgrp-3");
1500 rcode = checkjobs(pi);
1501 /* move the shell to the foreground */
1502 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1503 perror_msg("tcsetpgrp-4");
1504 } else {
1505 rcode = checkjobs(pi);
1506 }
1507 debug_printf("checkjobs returned %d\n",rcode);
1508 }
1509 last_return_code=rcode;
1510 if ( rmode == RES_IF || rmode == RES_ELIF )
1511 next_if_code=rcode; /* can be overwritten a number of times */
1512 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1513 (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1514 skip_more_in_this_rmode=rmode;
1515 checkjobs(NULL);
1516 }
1517 return rcode;
1518}
1519
1520/* broken, of course, but OK for testing */
1521static char *indenter(int i)
1522{
1523 static char blanks[]=" ";
1524 return &blanks[sizeof(blanks)-i-1];
1525}
1526
1527/* return code is the exit status of the pipe */
1528static int free_pipe(struct pipe *pi, int indent)
1529{
1530 char **p;
1531 struct child_prog *child;
1532 struct redir_struct *r, *rnext;
1533 int a, i, ret_code=0;
1534 char *ind = indenter(indent);
1535
1536 if (pi->stopped_progs > 0)
1537 return ret_code;
1538 final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1539 for (i=0; i<pi->num_progs; i++) {
1540 child = &pi->progs[i];
1541 final_printf("%s command %d:\n",ind,i);
1542 if (child->argv) {
1543 for (a=0,p=child->argv; *p; a++,p++) {
1544 final_printf("%s argv[%d] = %s\n",ind,a,*p);
1545 }
1546 globfree(&child->glob_result);
1547 child->argv=NULL;
1548 } else if (child->group) {
1549 final_printf("%s begin group (subshell:%d)\n",ind, child->subshell);
1550 ret_code = free_pipe_list(child->group,indent+3);
1551 final_printf("%s end group\n",ind);
1552 } else {
1553 final_printf("%s (nil)\n",ind);
1554 }
1555 for (r=child->redirects; r; r=rnext) {
1556 final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1557 if (r->dup == -1) {
1558 /* guard against the case >$FOO, where foo is unset or blank */
1559 if (r->word.gl_pathv) {
1560 final_printf(" %s\n", *r->word.gl_pathv);
1561 globfree(&r->word);
1562 }
1563 } else {
1564 final_printf("&%d\n", r->dup);
1565 }
1566 rnext=r->next;
1567 free(r);
1568 }
1569 child->redirects=NULL;
1570 }
1571 free(pi->progs); /* children are an array, they get freed all at once */
1572 pi->progs=NULL;
1573 return ret_code;
1574}
1575
1576static int free_pipe_list(struct pipe *head, int indent)
1577{
1578 int rcode=0; /* if list has no members */
1579 struct pipe *pi, *next;
1580 char *ind = indenter(indent);
1581 for (pi=head; pi; pi=next) {
1582 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1583 rcode = free_pipe(pi, indent);
1584 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1585 next=pi->next;
1586 pi->next=NULL;
1587 free(pi);
1588 }
1589 return rcode;
1590}
1591
1592/* Select which version we will use */
1593static int run_list(struct pipe *pi)
1594{
1595 int rcode=0;
1596 if (fake_mode==0) {
1597 rcode = run_list_real(pi);
1598 }
1599 /* free_pipe_list has the side effect of clearing memory
1600 * In the long run that function can be merged with run_list_real,
1601 * but doing that now would hobble the debugging effort. */
1602 free_pipe_list(pi,0);
1603 return rcode;
1604}
1605
1606/* The API for glob is arguably broken. This routine pushes a non-matching
1607 * string into the output structure, removing non-backslashed backslashes.
1608 * If someone can prove me wrong, by performing this function within the
1609 * original glob(3) api, feel free to rewrite this routine into oblivion.
1610 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1611 * XXX broken if the last character is '\\', check that before calling.
1612 */
1613static int globhack(const char *src, int flags, glob_t *pglob)
1614{
1615 int cnt=0, pathc;
1616 const char *s;
1617 char *dest;
1618 for (cnt=1, s=src; s && *s; s++) {
1619 if (*s == '\\') s++;
1620 cnt++;
1621 }
1622 dest = malloc(cnt);
1623 if (!dest) return GLOB_NOSPACE;
1624 if (!(flags & GLOB_APPEND)) {
1625 pglob->gl_pathv=NULL;
1626 pglob->gl_pathc=0;
1627 pglob->gl_offs=0;
1628 pglob->gl_offs=0;
1629 }
1630 pathc = ++pglob->gl_pathc;
1631 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1632 if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
1633 pglob->gl_pathv[pathc-1]=dest;
1634 pglob->gl_pathv[pathc]=NULL;
1635 for (s=src; s && *s; s++, dest++) {
1636 if (*s == '\\') s++;
1637 *dest = *s;
1638 }
1639 *dest='\0';
1640 return 0;
1641}
1642
1643/* XXX broken if the last character is '\\', check that before calling */
1644static int glob_needed(const char *s)
1645{
1646 for (; *s; s++) {
1647 if (*s == '\\') s++;
1648 if (strchr("*[?",*s)) return 1;
1649 }
1650 return 0;
1651}
1652
1653#if 0
1654static void globprint(glob_t *pglob)
1655{
1656 int i;
1657 debug_printf("glob_t at %p:\n", pglob);
1658 debug_printf(" gl_pathc=%d gl_pathv=%p gl_offs=%d gl_flags=%d\n",
1659 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
1660 for (i=0; i<pglob->gl_pathc; i++)
1661 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
1662 pglob->gl_pathv[i], pglob->gl_pathv[i]);
1663}
1664#endif
1665
1666static int xglob(o_string *dest, int flags, glob_t *pglob)
1667{
1668 int gr;
1669
1670 /* short-circuit for null word */
1671 /* we can code this better when the debug_printf's are gone */
1672 if (dest->length == 0) {
1673 if (dest->nonnull) {
1674 /* bash man page calls this an "explicit" null */
1675 gr = globhack(dest->data, flags, pglob);
1676 debug_printf("globhack returned %d\n",gr);
1677 } else {
1678 return 0;
1679 }
1680 } else if (glob_needed(dest->data)) {
1681 gr = glob(dest->data, flags, NULL, pglob);
1682 debug_printf("glob returned %d\n",gr);
1683 if (gr == GLOB_NOMATCH) {
1684 /* quote removal, or more accurately, backslash removal */
1685 gr = globhack(dest->data, flags, pglob);
1686 debug_printf("globhack returned %d\n",gr);
1687 }
1688 } else {
1689 gr = globhack(dest->data, flags, pglob);
1690 debug_printf("globhack returned %d\n",gr);
1691 }
1692 if (gr == GLOB_NOSPACE)
1693 error_msg_and_die("out of memory during glob");
1694 if (gr != 0) { /* GLOB_ABORTED ? */
1695 error_msg("glob(3) error %d",gr);
1696 }
1697 /* globprint(glob_target); */
1698 return gr;
1699}
1700
1701/* This is used to get/check local shell variables */
1702static char *get_local_var(const char *s)
1703{
1704 struct variables *cur;
1705
1706 if (!s)
1707 return NULL;
1708 for (cur = top_vars; cur; cur=cur->next)
1709 if(strcmp(cur->name, s)==0)
1710 return cur->value;
1711 return NULL;
1712}
1713
1714/* This is used to set local shell variables
1715 flg_export==0 if only local (not exporting) variable
1716 flg_export==1 if "new" exporting environ
1717 flg_export>1 if current startup environ (not call putenv()) */
1718static int set_local_var(const char *s, int flg_export)
1719{
1720 char *name, *value;
1721 int result=0;
1722 struct variables *cur;
1723
1724 name=strdup(s);
1725
1726 /* Assume when we enter this function that we are already in
1727 * NAME=VALUE format. So the first order of business is to
1728 * split 's' on the '=' into 'name' and 'value' */
1729 value = strchr(name, '=');
1730 if (value==0 && ++value==0) {
1731 free(name);
1732 return -1;
1733 }
1734 *value++ = 0;
1735
1736 for(cur = top_vars; cur; cur = cur->next) {
1737 if(strcmp(cur->name, name)==0)
1738 break;
1739 }
1740
1741 if(cur) {
1742 if(strcmp(cur->value, value)==0) {
1743 if(flg_export>0 && cur->flg_export==0)
1744 cur->flg_export=flg_export;
1745 else
1746 result++;
1747 } else {
1748 if(cur->flg_read_only) {
1749 error_msg("%s: readonly variable", name);
1750 result = -1;
1751 } else {
1752 if(flg_export>0 || cur->flg_export>1)
1753 cur->flg_export=1;
1754 free(cur->value);
1755
1756 cur->value = strdup(value);
1757 }
1758 }
1759 } else {
1760 cur = malloc(sizeof(struct variables));
1761 if(!cur) {
1762 result = -1;
1763 } else {
1764 cur->name = strdup(name);
1765 if(cur->name == 0) {
1766 free(cur);
1767 result = -1;
1768 } else {
1769 struct variables *bottom = top_vars;
1770 cur->value = strdup(value);
1771 cur->next = 0;
1772 cur->flg_export = flg_export;
1773 cur->flg_read_only = 0;
1774 while(bottom->next) bottom=bottom->next;
1775 bottom->next = cur;
1776 }
1777 }
1778 }
1779
1780 if(result==0 && cur->flg_export==1) {
1781 *(value-1) = '=';
1782 result = putenv(name);
1783 } else {
1784 free(name);
1785 if(result>0) /* equivalent to previous set */
1786 result = 0;
1787 }
1788 return result;
1789}
1790
1791static void unset_local_var(const char *name)
1792{
1793 struct variables *cur;
1794
1795 if (name) {
1796 for (cur = top_vars; cur; cur=cur->next) {
1797 if(strcmp(cur->name, name)==0)
1798 break;
1799 }
1800 if(cur!=0) {
1801 struct variables *next = top_vars;
1802 if(cur->flg_read_only) {
1803 error_msg("%s: readonly variable", name);
1804 return;
1805 } else {
1806 if(cur->flg_export)
1807 unsetenv(cur->name);
1808 free(cur->name);
1809 free(cur->value);
1810 while (next->next != cur)
1811 next = next->next;
1812 next->next = cur->next;
1813 }
1814 free(cur);
1815 }
1816 }
1817}
1818
1819static int is_assignment(const char *s)
1820{
1821 if (s==NULL || !isalpha(*s)) return 0;
1822 ++s;
1823 while(isalnum(*s) || *s=='_') ++s;
1824 return *s=='=';
1825}
1826
1827/* the src parameter allows us to peek forward to a possible &n syntax
1828 * for file descriptor duplication, e.g., "2>&1".
1829 * Return code is 0 normally, 1 if a syntax error is detected in src.
1830 * Resource errors (in xmalloc) cause the process to exit */
1831static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1832 struct in_str *input)
1833{
1834 struct child_prog *child=ctx->child;
1835 struct redir_struct *redir = child->redirects;
1836 struct redir_struct *last_redir=NULL;
1837
1838 /* Create a new redir_struct and drop it onto the end of the linked list */
1839 while(redir) {
1840 last_redir=redir;
1841 redir=redir->next;
1842 }
1843 redir = xmalloc(sizeof(struct redir_struct));
1844 redir->next=NULL;
1845 redir->word.gl_pathv=NULL;
1846 if (last_redir) {
1847 last_redir->next=redir;
1848 } else {
1849 child->redirects=redir;
1850 }
1851
1852 redir->type=style;
1853 redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
1854
1855 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1856
1857 /* Check for a '2>&1' type redirect */
1858 redir->dup = redirect_dup_num(input);
1859 if (redir->dup == -2) return 1; /* syntax error */
1860 if (redir->dup != -1) {
1861 /* Erik had a check here that the file descriptor in question
1862 * is legit; I postpone that to "run time"
1863 * A "-" representation of "close me" shows up as a -3 here */
1864 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
1865 } else {
1866 /* We do _not_ try to open the file that src points to,
1867 * since we need to return and let src be expanded first.
1868 * Set ctx->pending_redirect, so we know what to do at the
1869 * end of the next parsed word.
1870 */
1871 ctx->pending_redirect = redir;
1872 }
1873 return 0;
1874}
1875
1876struct pipe *new_pipe(void) {
1877 struct pipe *pi;
1878 pi = xmalloc(sizeof(struct pipe));
1879 pi->num_progs = 0;
1880 pi->progs = NULL;
1881 pi->next = NULL;
1882 pi->followup = 0; /* invalid */
1883 return pi;
1884}
1885
1886static void initialize_context(struct p_context *ctx)
1887{
1888 ctx->pipe=NULL;
1889 ctx->pending_redirect=NULL;
1890 ctx->child=NULL;
1891 ctx->list_head=new_pipe();
1892 ctx->pipe=ctx->list_head;
1893 ctx->w=RES_NONE;
1894 ctx->stack=NULL;
1895 done_command(ctx); /* creates the memory for working child */
1896}
1897
1898/* normal return is 0
1899 * if a reserved word is found, and processed, return 1
1900 * should handle if, then, elif, else, fi, for, while, until, do, done.
1901 * case, function, and select are obnoxious, save those for later.
1902 */
1903int reserved_word(o_string *dest, struct p_context *ctx)
1904{
1905 struct reserved_combo {
1906 char *literal;
1907 int code;
1908 long flag;
1909 };
1910 /* Mostly a list of accepted follow-up reserved words.
1911 * FLAG_END means we are done with the sequence, and are ready
1912 * to turn the compound list into a command.
1913 * FLAG_START means the word must start a new compound list.
1914 */
1915 static struct reserved_combo reserved_list[] = {
1916 { "if", RES_IF, FLAG_THEN | FLAG_START },
1917 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
1918 { "elif", RES_ELIF, FLAG_THEN },
1919 { "else", RES_ELSE, FLAG_FI },
1920 { "fi", RES_FI, FLAG_END },
1921 { "for", RES_FOR, FLAG_DO | FLAG_START },
1922 { "while", RES_WHILE, FLAG_DO | FLAG_START },
1923 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
1924 { "do", RES_DO, FLAG_DONE },
1925 { "done", RES_DONE, FLAG_END }
1926 };
1927 struct reserved_combo *r;
1928 for (r=reserved_list;
1929#define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
1930 r<reserved_list+NRES; r++) {
1931 if (strcmp(dest->data, r->literal) == 0) {
1932 debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
1933 if (r->flag & FLAG_START) {
1934 struct p_context *new = xmalloc(sizeof(struct p_context));
1935 debug_printf("push stack\n");
1936 *new = *ctx; /* physical copy */
1937 initialize_context(ctx);
1938 ctx->stack=new;
1939 } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
1940 syntax();
1941 ctx->w = RES_SNTX;
1942 b_reset (dest);
1943 return 1;
1944 }
1945 ctx->w=r->code;
1946 ctx->old_flag = r->flag;
1947 if (ctx->old_flag & FLAG_END) {
1948 struct p_context *old;
1949 debug_printf("pop stack\n");
1950 old = ctx->stack;
1951 old->child->group = ctx->list_head;
1952 old->child->subshell = 0;
1953 *ctx = *old; /* physical copy */
1954 free(old);
1955 }
1956 b_reset (dest);
1957 return 1;
1958 }
1959 }
1960 return 0;
1961}
1962
1963/* normal return is 0.
1964 * Syntax or xglob errors return 1. */
1965static int done_word(o_string *dest, struct p_context *ctx)
1966{
1967 struct child_prog *child=ctx->child;
1968 glob_t *glob_target;
1969 int gr, flags = 0;
1970
1971 debug_printf("done_word: %s %p\n", dest->data, child);
1972 if (dest->length == 0 && !dest->nonnull) {
1973 debug_printf(" true null, ignored\n");
1974 return 0;
1975 }
1976 if (ctx->pending_redirect) {
1977 glob_target = &ctx->pending_redirect->word;
1978 } else {
1979 if (child->group) {
1980 syntax();
1981 return 1; /* syntax error, groups and arglists don't mix */
1982 }
1983 if (!child->argv) {
1984 debug_printf("checking %s for reserved-ness\n",dest->data);
1985 if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
1986 }
1987 glob_target = &child->glob_result;
1988 if (child->argv) flags |= GLOB_APPEND;
1989 }
1990 gr = xglob(dest, flags, glob_target);
1991 if (gr != 0) return 1;
1992
1993 b_reset(dest);
1994 if (ctx->pending_redirect) {
1995 ctx->pending_redirect=NULL;
1996 if (glob_target->gl_pathc != 1) {
1997 error_msg("ambiguous redirect");
1998 return 1;
1999 }
2000 } else {
2001 child->argv = glob_target->gl_pathv;
2002 }
2003 return 0;
2004}
2005
2006/* The only possible error here is out of memory, in which case
2007 * xmalloc exits. */
2008static int done_command(struct p_context *ctx)
2009{
2010 /* The child is really already in the pipe structure, so
2011 * advance the pipe counter and make a new, null child.
2012 * Only real trickiness here is that the uncommitted
2013 * child structure, to which ctx->child points, is not
2014 * counted in pi->num_progs. */
2015 struct pipe *pi=ctx->pipe;
2016 struct child_prog *prog=ctx->child;
2017
2018 if (prog && prog->group == NULL
2019 && prog->argv == NULL
2020 && prog->redirects == NULL) {
2021 debug_printf("done_command: skipping null command\n");
2022 return 0;
2023 } else if (prog) {
2024 pi->num_progs++;
2025 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2026 } else {
2027 debug_printf("done_command: initializing\n");
2028 }
2029 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2030
2031 prog = pi->progs + pi->num_progs;
2032 prog->redirects = NULL;
2033 prog->argv = NULL;
2034 prog->is_stopped = 0;
2035 prog->group = NULL;
2036 prog->glob_result.gl_pathv = NULL;
2037 prog->family = pi;
2038
2039 ctx->child=prog;
2040 /* but ctx->pipe and ctx->list_head remain unchanged */
2041 return 0;
2042}
2043
2044static int done_pipe(struct p_context *ctx, pipe_style type)
2045{
2046 struct pipe *new_p;
2047 done_command(ctx); /* implicit closure of previous command */
2048 debug_printf("done_pipe, type %d\n", type);
2049 ctx->pipe->followup = type;
2050 ctx->pipe->r_mode = ctx->w;
2051 new_p=new_pipe();
2052 ctx->pipe->next = new_p;
2053 ctx->pipe = new_p;
2054 ctx->child = NULL;
2055 done_command(ctx); /* set up new pipe to accept commands */
2056 return 0;
2057}
2058
2059/* peek ahead in the in_str to find out if we have a "&n" construct,
2060 * as in "2>&1", that represents duplicating a file descriptor.
2061 * returns either -2 (syntax error), -1 (no &), or the number found.
2062 */
2063static int redirect_dup_num(struct in_str *input)
2064{
2065 int ch, d=0, ok=0;
2066 ch = b_peek(input);
2067 if (ch != '&') return -1;
2068
2069 b_getch(input); /* get the & */
2070 ch=b_peek(input);
2071 if (ch == '-') {
2072 b_getch(input);
2073 return -3; /* "-" represents "close me" */
2074 }
2075 while (isdigit(ch)) {
2076 d = d*10+(ch-'0');
2077 ok=1;
2078 b_getch(input);
2079 ch = b_peek(input);
2080 }
2081 if (ok) return d;
2082
2083 error_msg("ambiguous redirect");
2084 return -2;
2085}
2086
2087/* If a redirect is immediately preceded by a number, that number is
2088 * supposed to tell which file descriptor to redirect. This routine
2089 * looks for such preceding numbers. In an ideal world this routine
2090 * needs to handle all the following classes of redirects...
2091 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2092 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2093 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2094 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2095 * A -1 output from this program means no valid number was found, so the
2096 * caller should use the appropriate default for this redirection.
2097 */
2098static int redirect_opt_num(o_string *o)
2099{
2100 int num;
2101
2102 if (o->length==0) return -1;
2103 for(num=0; num<o->length; num++) {
2104 if (!isdigit(*(o->data+num))) {
2105 return -1;
2106 }
2107 }
2108 /* reuse num (and save an int) */
2109 num=atoi(o->data);
2110 b_reset(o);
2111 return num;
2112}
2113
2114FILE *generate_stream_from_list(struct pipe *head)
2115{
2116 FILE *pf;
2117#if 1
2118 int pid, channel[2];
2119 if (pipe(channel)<0) perror_msg_and_die("pipe");
2120 pid=fork();
2121 if (pid<0) {
2122 perror_msg_and_die("fork");
2123 } else if (pid==0) {
2124 close(channel[0]);
2125 if (channel[1] != 1) {
2126 dup2(channel[1],1);
2127 close(channel[1]);
2128 }
2129#if 0
2130#define SURROGATE "surrogate response"
2131 write(1,SURROGATE,sizeof(SURROGATE));
2132 _exit(run_list(head));
2133#else
2134 _exit(run_list_real(head)); /* leaks memory */
2135#endif
2136 }
2137 debug_printf("forked child %d\n",pid);
2138 close(channel[1]);
2139 pf = fdopen(channel[0],"r");
2140 debug_printf("pipe on FILE *%p\n",pf);
2141#else
2142 free_pipe_list(head,0);
2143 pf=popen("echo surrogate response","r");
2144 debug_printf("started fake pipe on FILE *%p\n",pf);
2145#endif
2146 return pf;
2147}
2148
2149/* this version hacked for testing purposes */
2150/* return code is exit status of the process that is run. */
2151static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2152{
2153 int retcode;
2154 o_string result=NULL_O_STRING;
2155 struct p_context inner;
2156 FILE *p;
2157 struct in_str pipe_str;
2158 initialize_context(&inner);
2159
2160 /* recursion to generate command */
2161 retcode = parse_stream(&result, &inner, input, subst_end);
2162 if (retcode != 0) return retcode; /* syntax error or EOF */
2163 done_word(&result, &inner);
2164 done_pipe(&inner, PIPE_SEQ);
2165 b_free(&result);
2166
2167 p=generate_stream_from_list(inner.list_head);
2168 if (p==NULL) return 1;
2169 mark_open(fileno(p));
2170 setup_file_in_str(&pipe_str, p);
2171
2172 /* now send results of command back into original context */
2173 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2174 /* XXX In case of a syntax error, should we try to kill the child?
2175 * That would be tough to do right, so just read until EOF. */
2176 if (retcode == 1) {
2177 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2178 }
2179
2180 debug_printf("done reading from pipe, pclose()ing\n");
2181 /* This is the step that wait()s for the child. Should be pretty
2182 * safe, since we just read an EOF from its stdout. We could try
2183 * to better, by using wait(), and keeping track of background jobs
2184 * at the same time. That would be a lot of work, and contrary
2185 * to the KISS philosophy of this program. */
2186 mark_closed(fileno(p));
2187 retcode=pclose(p);
2188 free_pipe_list(inner.list_head,0);
2189 debug_printf("pclosed, retcode=%d\n",retcode);
2190 /* XXX this process fails to trim a single trailing newline */
2191 return retcode;
2192}
2193
2194static int parse_group(o_string *dest, struct p_context *ctx,
2195 struct in_str *input, int ch)
2196{
2197 int rcode, endch=0;
2198 struct p_context sub;
2199 struct child_prog *child = ctx->child;
2200 if (child->argv) {
2201 syntax();
2202 return 1; /* syntax error, groups and arglists don't mix */
2203 }
2204 initialize_context(&sub);
2205 switch(ch) {
2206 case '(': endch=')'; child->subshell=1; break;
2207 case '{': endch='}'; break;
2208 default: syntax(); /* really logic error */
2209 }
2210 rcode=parse_stream(dest,&sub,input,endch);
2211 done_word(dest,&sub); /* finish off the final word in the subcontext */
2212 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2213 child->group = sub.list_head;
2214 return rcode;
2215 /* child remains "open", available for possible redirects */
2216}
2217
2218/* basically useful version until someone wants to get fancier,
2219 * see the bash man page under "Parameter Expansion" */
2220static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src)
2221{
2222 const char *p=NULL;
2223 if (src->data) {
2224 p = getenv(src->data);
2225 if (!p)
2226 p = get_local_var(src->data);
2227 }
2228 if (p) parse_string(dest, ctx, p); /* recursion */
2229 b_free(src);
2230}
2231
2232/* return code: 0 for OK, 1 for syntax error */
2233static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2234{
2235 int i, advance=0;
2236 o_string alt=NULL_O_STRING;
2237 char sep[]=" ";
2238 int ch = input->peek(input); /* first character after the $ */
2239 debug_printf("handle_dollar: ch=%c\n",ch);
2240 if (isalpha(ch)) {
2241 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2242 b_getch(input);
2243 b_addchr(&alt,ch);
2244 }
2245 lookup_param(dest, ctx, &alt);
2246 } else if (isdigit(ch)) {
2247 i = ch-'0'; /* XXX is $0 special? */
2248 if (i<global_argc) {
2249 parse_string(dest, ctx, global_argv[i]); /* recursion */
2250 }
2251 advance = 1;
2252 } else switch (ch) {
2253 case '$':
2254 b_adduint(dest,getpid());
2255 advance = 1;
2256 break;
2257 case '!':
2258 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2259 advance = 1;
2260 break;
2261 case '?':
2262 b_adduint(dest,last_return_code);
2263 advance = 1;
2264 break;
2265 case '#':
2266 b_adduint(dest,global_argc ? global_argc-1 : 0);
2267 advance = 1;
2268 break;
2269 case '{':
2270 b_getch(input);
2271 /* XXX maybe someone will try to escape the '}' */
2272 while(ch=b_getch(input),ch!=EOF && ch!='}') {
2273 b_addchr(&alt,ch);
2274 }
2275 if (ch != '}') {
2276 syntax();
2277 return 1;
2278 }
2279 lookup_param(dest, ctx, &alt);
2280 break;
2281 case '(':
2282 b_getch(input);
2283 process_command_subs(dest, ctx, input, ')');
2284 break;
2285 case '*':
2286 sep[0]=ifs[0];
2287 for (i=1; i<global_argc; i++) {
2288 parse_string(dest, ctx, global_argv[i]);
2289 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2290 }
2291 break;
2292 case '@':
2293 case '-':
2294 case '_':
2295 /* still unhandled, but should be eventually */
2296 error_msg("unhandled syntax: $%c",ch);
2297 return 1;
2298 break;
2299 default:
2300 b_addqchr(dest,'$',dest->quote);
2301 }
2302 /* Eat the character if the flag was set. If the compiler
2303 * is smart enough, we could substitute "b_getch(input);"
2304 * for all the "advance = 1;" above, and also end up with
2305 * a nice size-optimized program. Hah! That'll be the day.
2306 */
2307 if (advance) b_getch(input);
2308 return 0;
2309}
2310
2311int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2312{
2313 struct in_str foo;
2314 setup_string_in_str(&foo, src);
2315 return parse_stream(dest, ctx, &foo, '\0');
2316}
2317
2318/* return code is 0 for normal exit, 1 for syntax error */
2319int parse_stream(o_string *dest, struct p_context *ctx,
2320 struct in_str *input, int end_trigger)
2321{
2322 unsigned int ch, m;
2323 int redir_fd;
2324 redir_type redir_style;
2325 int next;
2326
2327 /* Only double-quote state is handled in the state variable dest->quote.
2328 * A single-quote triggers a bypass of the main loop until its mate is
2329 * found. When recursing, quote state is passed in via dest->quote. */
2330
2331 debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2332 while ((ch=b_getch(input))!=EOF) {
2333 m = map[ch];
2334 next = (ch == '\n') ? 0 : b_peek(input);
2335 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2336 ch,ch,m,dest->quote);
2337 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2338 b_addqchr(dest, ch, dest->quote);
2339 } else {
2340 if (m==2) { /* unquoted IFS */
2341 done_word(dest, ctx);
2342 /* If we aren't performing a substitution, treat a newline as a
2343 * command separator. */
2344 if (end_trigger != '\0' && ch=='\n')
2345 done_pipe(ctx,PIPE_SEQ);
2346 }
2347 if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2348 debug_printf("leaving parse_stream (triggered)\n");
2349 return 0;
2350 }
2351#if 0
2352 if (ch=='\n') {
2353 /* Yahoo! Time to run with it! */
2354 done_pipe(ctx,PIPE_SEQ);
2355 run_list(ctx->list_head);
2356 initialize_context(ctx);
2357 }
2358#endif
2359 if (m!=2) switch (ch) {
2360 case '#':
2361 if (dest->length == 0 && !dest->quote) {
2362 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2363 } else {
2364 b_addqchr(dest, ch, dest->quote);
2365 }
2366 break;
2367 case '\\':
2368 if (next == EOF) {
2369 syntax();
2370 return 1;
2371 }
2372 b_addqchr(dest, '\\', dest->quote);
2373 b_addqchr(dest, b_getch(input), dest->quote);
2374 break;
2375 case '$':
2376 if (handle_dollar(dest, ctx, input)!=0) return 1;
2377 break;
2378 case '\'':
2379 dest->nonnull = 1;
2380 while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2381 b_addchr(dest,ch);
2382 }
2383 if (ch==EOF) {
2384 syntax();
2385 return 1;
2386 }
2387 break;
2388 case '"':
2389 dest->nonnull = 1;
2390 dest->quote = !dest->quote;
2391 break;
2392 case '`':
2393 process_command_subs(dest, ctx, input, '`');
2394 break;
2395 case '>':
2396 redir_fd = redirect_opt_num(dest);
2397 done_word(dest, ctx);
2398 redir_style=REDIRECT_OVERWRITE;
2399 if (next == '>') {
2400 redir_style=REDIRECT_APPEND;
2401 b_getch(input);
2402 } else if (next == '(') {
2403 syntax(); /* until we support >(list) Process Substitution */
2404 return 1;
2405 }
2406 setup_redirect(ctx, redir_fd, redir_style, input);
2407 break;
2408 case '<':
2409 redir_fd = redirect_opt_num(dest);
2410 done_word(dest, ctx);
2411 redir_style=REDIRECT_INPUT;
2412 if (next == '<') {
2413 redir_style=REDIRECT_HEREIS;
2414 b_getch(input);
2415 } else if (next == '>') {
2416 redir_style=REDIRECT_IO;
2417 b_getch(input);
2418 } else if (next == '(') {
2419 syntax(); /* until we support <(list) Process Substitution */
2420 return 1;
2421 }
2422 setup_redirect(ctx, redir_fd, redir_style, input);
2423 break;
2424 case ';':
2425 done_word(dest, ctx);
2426 done_pipe(ctx,PIPE_SEQ);
2427 break;
2428 case '&':
2429 done_word(dest, ctx);
2430 if (next=='&') {
2431 b_getch(input);
2432 done_pipe(ctx,PIPE_AND);
2433 } else {
2434 done_pipe(ctx,PIPE_BG);
2435 }
2436 break;
2437 case '|':
2438 done_word(dest, ctx);
2439 if (next=='|') {
2440 b_getch(input);
2441 done_pipe(ctx,PIPE_OR);
2442 } else {
2443 /* we could pick up a file descriptor choice here
2444 * with redirect_opt_num(), but bash doesn't do it.
2445 * "echo foo 2| cat" yields "foo 2". */
2446 done_command(ctx);
2447 }
2448 break;
2449 case '(':
2450 case '{':
2451 if (parse_group(dest, ctx, input, ch)!=0) return 1;
2452 break;
2453 case ')':
2454 case '}':
2455 syntax(); /* Proper use of this character caught by end_trigger */
2456 return 1;
2457 break;
2458 default:
2459 syntax(); /* this is really an internal logic error */
2460 return 1;
2461 }
2462 }
2463 }
2464 /* complain if quote? No, maybe we just finished a command substitution
2465 * that was quoted. Example:
2466 * $ echo "`cat foo` plus more"
2467 * and we just got the EOF generated by the subshell that ran "cat foo"
2468 * The only real complaint is if we got an EOF when end_trigger != '\0',
2469 * that is, we were really supposed to get end_trigger, and never got
2470 * one before the EOF. Can't use the standard "syntax error" return code,
2471 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
2472 debug_printf("leaving parse_stream (EOF)\n");
2473 if (end_trigger != '\0') return -1;
2474 return 0;
2475}
2476
2477void mapset(const unsigned char *set, int code)
2478{
2479 const unsigned char *s;
2480 for (s=set; *s; s++) map[*s] = code;
2481}
2482
2483void update_ifs_map(void)
2484{
2485 /* char *ifs and char map[256] are both globals. */
2486 ifs = getenv("IFS");
2487 if (ifs == NULL) ifs=" \t\n";
2488 /* Precompute a list of 'flow through' behavior so it can be treated
2489 * quickly up front. Computation is necessary because of IFS.
2490 * Special case handling of IFS == " \t\n" is not implemented.
2491 * The map[] array only really needs two bits each, and on most machines
2492 * that would be faster because of the reduced L1 cache footprint.
2493 */
2494 memset(map,0,sizeof(map)); /* most characters flow through always */
2495 mapset("\\$'\"`", 3); /* never flow through */
2496 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2497 mapset(ifs, 2); /* also flow through if quoted */
2498}
2499
2500/* most recursion does not come through here, the exeception is
2501 * from builtin_source() */
2502int parse_stream_outer(struct in_str *inp)
2503{
2504
2505 struct p_context ctx;
2506 o_string temp=NULL_O_STRING;
2507 int rcode;
2508 do {
2509 initialize_context(&ctx);
2510 update_ifs_map();
2511 inp->promptmode=1;
2512 rcode = parse_stream(&temp, &ctx, inp, '\n');
2513 done_word(&temp, &ctx);
2514 done_pipe(&ctx,PIPE_SEQ);
2515 run_list(ctx.list_head);
2516 b_free(&temp);
2517 } while (rcode != -1); /* loop on syntax errors, return on EOF */
2518 return 0;
2519}
2520
2521static int parse_string_outer(const char *s)
2522{
2523 struct in_str input;
2524 setup_string_in_str(&input, s);
2525 return parse_stream_outer(&input);
2526}
2527
2528static int parse_file_outer(FILE *f)
2529{
2530 int rcode;
2531 struct in_str input;
2532 setup_file_in_str(&input, f);
2533 rcode = parse_stream_outer(&input);
2534 return rcode;
2535}
2536
2537/* Make sure we have a controlling tty. If we get started under a job
2538 * aware app (like bash for example), make sure we are now in charge so
2539 * we don't fight over who gets the foreground */
2540static void setup_job_control()
2541{
2542 static pid_t shell_pgrp;
2543 /* Loop until we are in the foreground. */
2544 while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
2545 kill (- shell_pgrp, SIGTTIN);
2546
2547 /* Ignore interactive and job-control signals. */
2548 signal(SIGINT, SIG_IGN);
2549 signal(SIGQUIT, SIG_IGN);
2550 signal(SIGTERM, SIG_IGN);
2551 signal(SIGTSTP, SIG_IGN);
2552 signal(SIGTTIN, SIG_IGN);
2553 signal(SIGTTOU, SIG_IGN);
2554 signal(SIGCHLD, SIG_IGN);
2555
2556 /* Put ourselves in our own process group. */
2557 setsid();
2558 shell_pgrp = getpid ();
2559 setpgid (shell_pgrp, shell_pgrp);
2560
2561 /* Grab control of the terminal. */
2562 tcsetpgrp(shell_terminal, shell_pgrp);
2563}
2564
2565int hush_main(int argc, char **argv)
2566{
2567 int opt;
2568 FILE *input;
2569 char **e = environ;
2570
2571 /* XXX what should these be while sourcing /etc/profile? */
2572 global_argc = argc;
2573 global_argv = argv;
2574
2575 /* (re?) initialize globals. Sometimes hush_main() ends up calling
2576 * hush_main(), therefore we cannot rely on the BSS to zero out this
2577 * stuff. Reset these to 0 every time. */
2578 ifs = NULL;
2579 /* map[] is taken care of with call to update_ifs_map() */
2580 fake_mode = 0;
2581 interactive = 0;
2582 close_me_head = NULL;
2583 last_bg_pid = 0;
2584 job_list = NULL;
2585 last_jobid = 0;
2586
2587 /* Initialize some more globals to non-zero values */
2588 set_cwd();
2589#ifdef BB_FEATURE_COMMAND_EDITING
2590 cmdedit_set_initial_prompt();
2591#else
2592 PS1 = NULL;
2593#endif
2594 PS2 = "> ";
2595
2596 /* initialize our shell local variables with the values
2597 * currently living in the environment */
2598 if (e) {
2599 for (; *e; e++)
2600 set_local_var(*e, 2); /* without call putenv() */
2601 }
2602
2603 last_return_code=EXIT_SUCCESS;
2604
2605
2606 if (argv[0] && argv[0][0] == '-') {
2607 debug_printf("\nsourcing /etc/profile\n");
2608 if ((input = fopen("/etc/profile", "r")) != NULL) {
2609 mark_open(fileno(input));
2610 parse_file_outer(input);
2611 mark_closed(fileno(input));
2612 fclose(input);
2613 }
2614 }
2615 input=stdin;
2616
2617 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2618 switch (opt) {
2619 case 'c':
2620 {
2621 global_argv = argv+optind;
2622 global_argc = argc-optind;
2623 opt = parse_string_outer(optarg);
2624 goto final_return;
2625 }
2626 break;
2627 case 'i':
2628 interactive++;
2629 break;
2630 case 'f':
2631 fake_mode++;
2632 break;
2633 default:
2634#ifndef BB_VER
2635 fprintf(stderr, "Usage: sh [FILE]...\n"
2636 " or: sh -c command [args]...\n\n");
2637 exit(EXIT_FAILURE);
2638#else
2639 show_usage();
2640#endif
2641 }
2642 }
2643 /* A shell is interactive if the `-i' flag was given, or if all of
2644 * the following conditions are met:
2645 * no -c command
2646 * no arguments remaining or the -s flag given
2647 * standard input is a terminal
2648 * standard output is a terminal
2649 * Refer to Posix.2, the description of the `sh' utility. */
2650 if (argv[optind]==NULL && input==stdin &&
2651 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
2652 interactive++;
2653 }
2654
2655 debug_printf("\ninteractive=%d\n", interactive);
2656 if (interactive) {
2657 /* Looks like they want an interactive shell */
2658#ifndef BB_FEATURE_SH_EXTRA_QUIET
2659 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
2660 printf( "Enter 'help' for a list of built-in commands.\n\n");
2661#endif
2662 setup_job_control();
2663 }
2664
2665 if (argv[optind]==NULL) {
2666 opt=parse_file_outer(stdin);
2667 goto final_return;
2668 }
2669
2670 debug_printf("\nrunning script '%s'\n", argv[optind]);
2671 global_argv = argv+optind;
2672 global_argc = argc-optind;
2673 input = xfopen(argv[optind], "r");
2674 opt = parse_file_outer(input);
2675
2676#ifdef BB_FEATURE_CLEAN_UP
2677 fclose(input);
2678 if (cwd && cwd != unknown)
2679 free((char*)cwd);
2680 {
2681 struct variables *cur, *tmp;
2682 for(cur = top_vars; cur; cur = tmp) {
2683 tmp = cur->next;
2684 if (!cur->flg_read_only) {
2685 free(cur->name);
2686 free(cur->value);
2687 free(cur);
2688 }
2689 }
2690 }
2691#endif
2692
2693final_return:
2694 return(opt?opt:last_return_code);
2695}
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-03-24 00:52:14 +0000