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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 * Arithmetic Expansion
47 * <(list) and >(list) Process Substitution
48 * reserved words: if, then, elif, else, fi, while, until, for,
49 * do, done, case
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 * incomplete reserved word sequence doesn't request more lines of input
56 * to-do:
57 * port selected bugfixes from post-0.49 busybox lash
58 * finish implementing reserved words
59 * handle children going into background
60 * clean up recognition of null pipes
61 * have builtin_exec set flag to avoid restore_redirects
62 * figure out if "echo foo}" is fixable
63 * check setting of global_argc and global_argv
64 * control-C handling, probably with longjmp
65 * VAR=value prefix for simple commands
66 * follow IFS rules more precisely, including update semantics
67 * write builtin_eval, builtin_ulimit, builtin_umask
68 * figure out what to do with backslash-newline
69 * explain why we use signal instead of sigaction
70 * propagate syntax errors, die on resource errors?
71 * continuation lines, both explicit and implicit - done?
72 * memory leak finding and plugging - done?
73 * more testing, especially quoting rules and redirection
74 * maybe change map[] to use 2-bit entries
75 * (eventually) remove all the printf's
76 * more integration with BusyBox: prompts, cmdedit, applets
77 *
78 * This program is free software; you can redistribute it and/or modify
79 * it under the terms of the GNU General Public License as published by
80 * the Free Software Foundation; either version 2 of the License, or
81 * (at your option) any later version.
82 *
83 * This program is distributed in the hope that it will be useful,
84 * but WITHOUT ANY WARRANTY; without even the implied warranty of
85 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
86 * General Public License for more details.
87 *
88 * You should have received a copy of the GNU General Public License
89 * along with this program; if not, write to the Free Software
90 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
91 */
92#include <ctype.h> /* isalpha, isdigit */
93#include <unistd.h> /* getpid */
94#include <stdlib.h> /* getenv, atoi */
95#include <string.h> /* strchr */
96#include <stdio.h> /* popen etc. */
97#include <glob.h> /* glob, of course */
98#include <stdarg.h> /* va_list */
99#include <errno.h>
100#include <fcntl.h>
101#include <getopt.h> /* should be pretty obvious */
102
103#include <sys/types.h>
104#include <sys/wait.h>
105#include <signal.h>
106
107/* #include <dmalloc.h> */
108/* #define DEBUG_SHELL */
109
110#ifdef BB_VER
111#include "busybox.h"
112#include "cmdedit.h"
113#else
114/* in place of #include "busybox.h"; much of this is indeed
115 * pasted in from the copy of busybox.h in busybox-0.49pre */
116
117#define xrealloc realloc
118#define applet_name "hush"
119#define shell_main main
120
121extern void *xmalloc(size_t size)
122{
123 void *ptr = malloc(size);
124
125 if (!ptr) {
126 fprintf(stderr, "memory_exhausted\n");
127 exit (EXIT_FAILURE);
128 }
129 return ptr;
130}
131
132extern void usage(const char *usage)
133{
134 fprintf(stderr, "Usage: %s\n", usage);
135 exit(EXIT_FAILURE);
136}
137
138static void verror_msg(const char *s, va_list p)
139{
140 fflush(stdout);
141 fprintf(stderr, "%s: ", applet_name);
142 vfprintf(stderr, s, p);
143 fflush(stderr);
144}
145
146extern void error_msg(const char *s, ...)
147{
148 va_list p;
149
150 va_start(p, s);
151 verror_msg(s, p);
152 va_end(p);
153}
154
155extern void error_msg_and_die(const char *s, ...)
156{
157 va_list p;
158
159 va_start(p, s);
160 verror_msg(s, p);
161 va_end(p);
162 exit(EXIT_FAILURE);
163}
164
165static void vperror_msg(const char *s, va_list p)
166{
167 fflush(stdout);
168 fprintf(stderr, "%s: ", applet_name);
169 if (s && *s) {
170 vfprintf(stderr, s, p);
171 fputs(": ", stderr);
172 }
173 fprintf(stderr, "%s\n", strerror(errno));
174 fflush(stderr);
175}
176
177extern void perror_msg(const char *s, ...)
178{
179 va_list p;
180
181 va_start(p, s);
182 vperror_msg(s, p);
183 va_end(p);
184}
185
186extern void perror_msg_and_die(const char *s, ...)
187{
188 va_list p;
189
190 va_start(p, s);
191 vperror_msg(s, p);
192 va_end(p);
193 exit(EXIT_FAILURE);
194}
195
196FILE *xfopen(const char *path, const char *mode)
197{
198 FILE *fp;
199 if ((fp = fopen(path, mode)) == NULL)
200 perror_msg_and_die(path);
201 return fp;
202}
203#endif /* of busybox.h replacement */
204
205typedef enum {
206 REDIRECT_INPUT = 1,
207 REDIRECT_OVERWRITE = 2,
208 REDIRECT_APPEND = 3,
209 REDIRECT_HEREIS = 4,
210 REDIRECT_IO = 5
211} redir_type;
212
213/* The descrip member of this structure is only used to make debugging
214 * output pretty */
215struct {int mode; int default_fd; char *descrip;} redir_table[] = {
216 { 0, 0, "()" },
217 { O_RDONLY, 0, "<" },
218 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
219 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
220 { O_RDONLY, -1, "<<" },
221 { O_RDWR, 1, "<>" }
222};
223
224typedef enum {
225 PIPE_SEQ = 1,
226 PIPE_AND = 2,
227 PIPE_OR = 3,
228 PIPE_BG = 4,
229} pipe_style;
230
231/* might eventually control execution */
232typedef enum {
233 RES_NONE = 0,
234 RES_IF = 1,
235 RES_THEN = 2,
236 RES_ELIF = 3,
237 RES_ELSE = 4,
238 RES_FI = 5,
239 RES_FOR = 6,
240 RES_WHILE = 7,
241 RES_UNTIL = 8,
242 RES_DO = 9,
243 RES_DONE = 10,
244 RES_XXXX = 11
245} reserved_style;
246#define FLAG_END (1<<RES_NONE)
247#define FLAG_IF (1<<RES_IF)
248#define FLAG_THEN (1<<RES_THEN)
249#define FLAG_ELIF (1<<RES_ELIF)
250#define FLAG_ELSE (1<<RES_ELSE)
251#define FLAG_FI (1<<RES_FI)
252#define FLAG_FOR (1<<RES_FOR)
253#define FLAG_WHILE (1<<RES_WHILE)
254#define FLAG_UNTIL (1<<RES_UNTIL)
255#define FLAG_DO (1<<RES_DO)
256#define FLAG_DONE (1<<RES_DONE)
257#define FLAG_START (1<<RES_XXXX)
258
259/* This holds pointers to the various results of parsing */
260struct p_context {
261 struct child_prog *child;
262 struct pipe *list_head;
263 struct pipe *pipe;
264 struct redir_struct *pending_redirect;
265 reserved_style w;
266 int old_flag; /* for figuring out valid reserved words */
267 struct p_context *stack;
268 /* How about quoting status? */
269};
270
271struct redir_struct {
272 redir_type type; /* type of redirection */
273 int fd; /* file descriptor being redirected */
274 int dup; /* -1, or file descriptor being duplicated */
275 struct redir_struct *next; /* pointer to the next redirect in the list */
276 glob_t word; /* *word.gl_pathv is the filename */
277};
278
279struct child_prog {
280 pid_t pid; /* 0 if exited */
281 char **argv; /* program name and arguments */
282 struct pipe *group; /* if non-NULL, first in group or subshell */
283 int subshell; /* flag, non-zero if group must be forked */
284 struct redir_struct *redirects; /* I/O redirections */
285 glob_t glob_result; /* result of parameter globbing */
286 int is_stopped; /* is the program currently running? */
287 struct pipe *family; /* pointer back to the child's parent pipe */
288};
289
290struct pipe {
291 int jobid; /* job number */
292 int num_progs; /* total number of programs in job */
293 int running_progs; /* number of programs running */
294 char *text; /* name of job */
295 char *cmdbuf; /* buffer various argv's point into */
296 pid_t pgrp; /* process group ID for the job */
297 struct child_prog *progs; /* array of commands in pipe */
298 struct pipe *next; /* to track background commands */
299 int stopped_progs; /* number of programs alive, but stopped */
300 int job_context; /* bitmask defining current context */
301 pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
302 reserved_style r_mode; /* supports if, for, while, until */
303 struct jobset *job_list;
304};
305
306struct jobset {
307 struct pipe *head; /* head of list of running jobs */
308 struct pipe *fg; /* current foreground job */
309};
310
311struct close_me {
312 int fd;
313 struct close_me *next;
314};
315
316/* globals, connect us to the outside world
317 * the first three support $?, $#, and $1 */
318char **global_argv;
319unsigned int global_argc;
320unsigned int last_return_code;
321extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
322
323/* Variables we export */
324unsigned int shell_context; /* Used in cmdedit.c to reset the
325 * context when someone hits ^C */
326
327/* "globals" within this file */
328static char *ifs=NULL;
329static char map[256];
330static int fake_mode=0;
331static int interactive=0;
332static struct close_me *close_me_head = NULL;
333static char *cwd;
334static struct jobset job_list = { NULL, NULL };
335static unsigned int last_bg_pid=0;
336static char *PS1;
337static char *PS2 = "> ";
338
339#define B_CHUNK (100)
340#define B_NOSPAC 1
341#define MAX_LINE 256 /* for cwd */
342#define MAX_READ 256 /* for builtin_read */
343
344typedef struct {
345 char *data;
346 int length;
347 int maxlen;
348 int quote;
349 int nonnull;
350} o_string;
351#define NULL_O_STRING {NULL,0,0,0,0}
352/* used for initialization:
353 o_string foo = NULL_O_STRING; */
354
355/* I can almost use ordinary FILE *. Is open_memstream() universally
356 * available? Where is it documented? */
357struct in_str {
358 const char *p;
359 int __promptme;
360 int promptmode;
361 FILE *file;
362 int (*get) (struct in_str *);
363 int (*peek) (struct in_str *);
364};
365#define b_getch(input) ((input)->get(input))
366#define b_peek(input) ((input)->peek(input))
367
368#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
369
370struct built_in_command {
371 char *cmd; /* name */
372 char *descr; /* description */
373 int (*function) (struct child_prog *); /* function ptr */
374};
375
376/* belongs in busybox.h */
377static inline int max(int a, int b) {
378 return (a>b)?a:b;
379}
380
381/* This should be in utility.c */
382#ifdef DEBUG_SHELL
383static void debug_printf(const char *format, ...)
384{
385 va_list args;
386 va_start(args, format);
387 vfprintf(stderr, format, args);
388 va_end(args);
389}
390#else
391static void debug_printf(const char *format, ...) { }
392#endif
393#define final_printf debug_printf
394
395void __syntax(char *file, int line) {
396 fprintf(stderr,"syntax error %s:%d\n",file,line);
397}
398#define syntax() __syntax(__FILE__, __LINE__)
399
400/* Index of subroutines: */
401/* function prototypes for builtins */
402static int builtin_cd(struct child_prog *child);
403static int builtin_env(struct child_prog *child);
404static int builtin_exec(struct child_prog *child);
405static int builtin_exit(struct child_prog *child);
406static int builtin_export(struct child_prog *child);
407static int builtin_fg_bg(struct child_prog *child);
408static int builtin_help(struct child_prog *child);
409static int builtin_jobs(struct child_prog *child);
410static int builtin_pwd(struct child_prog *child);
411static int builtin_read(struct child_prog *child);
412static int builtin_shift(struct child_prog *child);
413static int builtin_source(struct child_prog *child);
414static int builtin_ulimit(struct child_prog *child);
415static int builtin_umask(struct child_prog *child);
416static int builtin_unset(struct child_prog *child);
417/* o_string manipulation: */
418static int b_check_space(o_string *o, int len);
419static int b_addchr(o_string *o, int ch);
420static void b_reset(o_string *o);
421static int b_addqchr(o_string *o, int ch, int quote);
422static int b_adduint(o_string *o, unsigned int i);
423/* in_str manipulations: */
424static int static_get(struct in_str *i);
425static int static_peek(struct in_str *i);
426static int file_get(struct in_str *i);
427static int file_peek(struct in_str *i);
428static void setup_file_in_str(struct in_str *i, FILE *f);
429static void setup_string_in_str(struct in_str *i, const char *s);
430/* close_me manipulations: */
431static void mark_open(int fd);
432static void mark_closed(int fd);
433static void close_all();
434/* "run" the final data structures: */
435static char *indenter(int i);
436static int run_list_test(struct pipe *head, int indent);
437static int run_pipe_test(struct pipe *pi, int indent);
438/* really run the final data structures: */
439static int setup_redirects(struct child_prog *prog, int squirrel[]);
440static int pipe_wait(struct pipe *pi);
441static int run_list_real(struct pipe *pi);
442static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
443static int run_pipe_real(struct pipe *pi);
444/* extended glob support: */
445static int globhack(const char *src, int flags, glob_t *pglob);
446static int glob_needed(const char *s);
447static int xglob(o_string *dest, int flags, glob_t *pglob);
448/* data structure manipulation: */
449static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
450static void initialize_context(struct p_context *ctx);
451static int done_word(o_string *dest, struct p_context *ctx);
452static int done_command(struct p_context *ctx);
453static int done_pipe(struct p_context *ctx, pipe_style type);
454/* primary string parsing: */
455static int redirect_dup_num(struct in_str *input);
456static int redirect_opt_num(o_string *o);
457static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
458static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
459static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src);
460static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
461static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
462static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
463/* setup: */
464static int parse_stream_outer(struct in_str *inp);
465static int parse_string_outer(const char *s);
466static int parse_file_outer(FILE *f);
467
468/* Table of built-in functions. They can be forked or not, depending on
469 * context: within pipes, they fork. As simple commands, they do not.
470 * When used in non-forking context, they can change global variables
471 * in the parent shell process. If forked, of course they can not.
472 * For example, 'unset foo | whatever' will parse and run, but foo will
473 * still be set at the end. */
474static struct built_in_command bltins[] = {
475 {"bg", "Resume a job in the background", builtin_fg_bg},
476 {"cd", "Change working directory", builtin_cd},
477 {"env", "Print all environment variables", builtin_env},
478 {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
479 {"exit", "Exit from shell()", builtin_exit},
480 {"export", "Set environment variable", builtin_export},
481 {"fg", "Bring job into the foreground", builtin_fg_bg},
482 {"jobs", "Lists the active jobs", builtin_jobs},
483 {"pwd", "Print current directory", builtin_pwd},
484 {"read", "Input environment variable", builtin_read},
485 {"shift", "Shift positional parameters", builtin_shift},
486 {"ulimit","Controls resource limits", builtin_ulimit},
487 {"umask","Sets file creation mask", builtin_umask},
488 {"unset", "Unset environment variable", builtin_unset},
489 {".", "Source-in and run commands in a file", builtin_source},
490 {"help", "List shell built-in commands", builtin_help},
491 {NULL, NULL, NULL}
492};
493
494/* built-in 'cd <path>' handler */
495static int builtin_cd(struct child_prog *child)
496{
497 char *newdir;
498 if (child->argv[1] == NULL)
499 newdir = getenv("HOME");
500 else
501 newdir = child->argv[1];
502 if (chdir(newdir)) {
503 printf("cd: %s: %s\n", newdir, strerror(errno));
504 return EXIT_FAILURE;
505 }
506 getcwd(cwd, sizeof(char)*MAX_LINE);
507 return EXIT_SUCCESS;
508}
509
510/* built-in 'env' handler */
511static int builtin_env(struct child_prog *dummy)
512{
513 char **e = environ;
514 if (e == NULL) return EXIT_FAILURE;
515 for (; *e; e++) {
516 puts(*e);
517 }
518 return EXIT_SUCCESS;
519}
520
521/* built-in 'exec' handler */
522static int builtin_exec(struct child_prog *child)
523{
524 if (child->argv[1] == NULL)
525 return EXIT_SUCCESS; /* Really? */
526 child->argv++;
527 pseudo_exec(child);
528 /* never returns */
529}
530
531/* built-in 'exit' handler */
532static int builtin_exit(struct child_prog *child)
533{
534 if (child->argv[1] == NULL)
535 exit(EXIT_SUCCESS);
536 exit (atoi(child->argv[1]));
537}
538
539/* built-in 'export VAR=value' handler */
540static int builtin_export(struct child_prog *child)
541{
542 int res;
543
544 if (child->argv[1] == NULL) {
545 return (builtin_env(child));
546 }
547 res = putenv(child->argv[1]);
548 if (res)
549 fprintf(stderr, "export: %s\n", strerror(errno));
550 return (res);
551}
552
553/* built-in 'fg' and 'bg' handler */
554static int builtin_fg_bg(struct child_prog *child)
555{
556 int i, jobNum;
557 struct pipe *job=NULL;
558
559 if (!child->argv[1] || child->argv[2]) {
560 error_msg("%s: exactly one argument is expected\n",
561 child->argv[0]);
562 return EXIT_FAILURE;
563 }
564
565 if (sscanf(child->argv[1], "%%%d", &jobNum) != 1) {
566 error_msg("%s: bad argument '%s'\n",
567 child->argv[0], child->argv[1]);
568 return EXIT_FAILURE;
569 }
570
571 for (job = child->family->job_list->head; job; job = job->next) {
572 if (job->jobid == jobNum) {
573 break;
574 }
575 }
576
577 if (!job) {
578 error_msg("%s: unknown job %d\n",
579 child->argv[0], jobNum);
580 return EXIT_FAILURE;
581 }
582
583 if (*child->argv[0] == 'f') {
584 /* Make this job the foreground job */
585 /* suppress messages when run from /linuxrc mag@sysgo.de */
586 if (tcsetpgrp(0, job->pgrp) && errno != ENOTTY)
587 perror_msg("tcsetpgrp");
588 child->family->job_list->fg = job;
589 }
590
591 /* Restart the processes in the job */
592 for (i = 0; i < job->num_progs; i++)
593 job->progs[i].is_stopped = 0;
594
595 kill(-job->pgrp, SIGCONT);
596
597 job->stopped_progs = 0;
598 return EXIT_SUCCESS;
599}
600
601/* built-in 'help' handler */
602static int builtin_help(struct child_prog *dummy)
603{
604 struct built_in_command *x;
605
606 printf("\nBuilt-in commands:\n");
607 printf("-------------------\n");
608 for (x = bltins; x->cmd; x++) {
609 if (x->descr==NULL)
610 continue;
611 printf("%s\t%s\n", x->cmd, x->descr);
612 }
613 printf("\n\n");
614 return EXIT_SUCCESS;
615}
616
617/* built-in 'jobs' handler */
618static int builtin_jobs(struct child_prog *child)
619{
620 struct pipe *job;
621 char *status_string;
622
623 for (job = child->family->job_list->head; job; job = job->next) {
624 if (job->running_progs == job->stopped_progs)
625 status_string = "Stopped";
626 else
627 status_string = "Running";
628 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
629 }
630 return EXIT_SUCCESS;
631}
632
633
634/* built-in 'pwd' handler */
635static int builtin_pwd(struct child_prog *dummy)
636{
637 getcwd(cwd, MAX_LINE);
638 puts(cwd);
639 return EXIT_SUCCESS;
640}
641
642/* built-in 'read VAR' handler */
643static int builtin_read(struct child_prog *child)
644{
645 int res = 0, len, newlen;
646 char *s;
647 char string[MAX_READ];
648
649 if (child->argv[1]) {
650 /* argument (VAR) given: put "VAR=" into buffer */
651 strcpy(string, child->argv[1]);
652 len = strlen(string);
653 string[len++] = '=';
654 string[len] = '\0';
655 /* XXX would it be better to go through in_str? */
656 fgets(&string[len], sizeof(string) - len, stdin); /* read string */
657 newlen = strlen(string);
658 if(newlen > len)
659 string[--newlen] = '\0'; /* chomp trailing newline */
660 /*
661 ** string should now contain "VAR=<value>"
662 ** copy it (putenv() won't do that, so we must make sure
663 ** the string resides in a static buffer!)
664 */
665 res = -1;
666 if((s = strdup(string)))
667 res = putenv(s);
668 if (res)
669 fprintf(stderr, "read: %s\n", strerror(errno));
670 }
671 else
672 fgets(string, sizeof(string), stdin);
673
674 return (res);
675}
676
677/* Built-in 'shift' handler */
678static int builtin_shift(struct child_prog *child)
679{
680 int n=1;
681 if (child->argv[1]) {
682 n=atoi(child->argv[1]);
683 }
684 if (n>=0 && n<global_argc) {
685 /* XXX This probably breaks $0 */
686 global_argc -= n;
687 global_argv += n;
688 return EXIT_SUCCESS;
689 } else {
690 return EXIT_FAILURE;
691 }
692}
693
694/* Built-in '.' handler (read-in and execute commands from file) */
695static int builtin_source(struct child_prog *child)
696{
697 FILE *input;
698 int status;
699
700 if (child->argv[1] == NULL)
701 return EXIT_FAILURE;
702
703 /* XXX search through $PATH is missing */
704 input = fopen(child->argv[1], "r");
705 if (!input) {
706 fprintf(stderr, "Couldn't open file '%s'\n", child->argv[1]);
707 return EXIT_FAILURE;
708 }
709
710 /* Now run the file */
711 /* XXX argv and argc are broken; need to save old global_argv
712 * (pointer only is OK!) on this stack frame,
713 * set global_argv=child->argv+1, recurse, and restore. */
714 mark_open(fileno(input));
715 status = parse_file_outer(input);
716 mark_closed(fileno(input));
717 fclose(input);
718 return (status);
719}
720
721static int builtin_ulimit(struct child_prog *child)
722{
723 printf("builtin_ulimit not written\n");
724 return EXIT_FAILURE;
725}
726
727static int builtin_umask(struct child_prog *child)
728{
729 printf("builtin_umask not written\n");
730 return EXIT_FAILURE;
731}
732
733/* built-in 'unset VAR' handler */
734static int builtin_unset(struct child_prog *child)
735{
736 if (child->argv[1] == NULL) {
737 fprintf(stderr, "unset: parameter required.\n");
738 return EXIT_FAILURE;
739 }
740 unsetenv(child->argv[1]);
741 return EXIT_SUCCESS;
742}
743
744static int b_check_space(o_string *o, int len)
745{
746 /* It would be easy to drop a more restrictive policy
747 * in here, such as setting a maximum string length */
748 if (o->length + len > o->maxlen) {
749 char *old_data = o->data;
750 /* assert (data == NULL || o->maxlen != 0); */
751 o->maxlen += max(2*len, B_CHUNK);
752 o->data = realloc(o->data, 1 + o->maxlen);
753 if (o->data == NULL) {
754 free(old_data);
755 }
756 }
757 return o->data == NULL;
758}
759
760static int b_addchr(o_string *o, int ch)
761{
762 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
763 if (b_check_space(o, 1)) return B_NOSPAC;
764 o->data[o->length] = ch;
765 o->length++;
766 o->data[o->length] = '\0';
767 return 0;
768}
769
770static void b_reset(o_string *o)
771{
772 o->length = 0;
773 o->nonnull = 0;
774 if (o->data != NULL) *o->data = '\0';
775}
776
777static void b_free(o_string *o)
778{
779 b_reset(o);
780 if (o->data != NULL) free(o->data);
781 o->data = NULL;
782 o->maxlen = 0;
783}
784
785/* My analysis of quoting semantics tells me that state information
786 * is associated with a destination, not a source.
787 */
788static int b_addqchr(o_string *o, int ch, int quote)
789{
790 if (quote && strchr("*?[\\",ch)) {
791 int rc;
792 rc = b_addchr(o, '\\');
793 if (rc) return rc;
794 }
795 return b_addchr(o, ch);
796}
797
798/* belongs in utility.c */
799char *simple_itoa(unsigned int i)
800{
801 /* 21 digits plus null terminator, good for 64-bit or smaller ints */
802 static char local[22];
803 char *p = &local[21];
804 *p-- = '\0';
805 do {
806 *p-- = '0' + i % 10;
807 i /= 10;
808 } while (i > 0);
809 return p + 1;
810}
811
812static int b_adduint(o_string *o, unsigned int i)
813{
814 int r;
815 char *p = simple_itoa(i);
816 /* no escape checking necessary */
817 do r=b_addchr(o, *p++); while (r==0 && *p);
818 return r;
819}
820
821static int static_get(struct in_str *i)
822{
823 int ch=*i->p++;
824 if (ch=='\0') return EOF;
825 return ch;
826}
827
828static int static_peek(struct in_str *i)
829{
830 return *i->p;
831}
832
833static inline void cmdedit_set_initial_prompt(void)
834{
835#ifdef BB_FEATURE_SH_SIMPLE_PROMPT
836 PS1 = NULL;
837#else
838 PS1 = getenv("PS1");
839 if(PS1==0)
840 PS1 = "\\w \\$ ";
841#endif
842}
843
844static inline void setup_prompt_string(int promptmode, char **prompt_str)
845{
846#ifdef BB_FEATURE_SH_SIMPLE_PROMPT
847 /* Set up the prompt */
848 if (promptmode == 1) {
849 if (PS1)
850 free(PS1);
851 PS1=xmalloc(strlen(cwd)+4);
852 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
853 *prompt_str = PS1;
854 } else {
855 *prompt_str = PS2;
856 }
857#else
858 *prompt_str = (promptmode==0)? PS1 : PS2;
859#endif
860}
861
862static void get_user_input(struct in_str *i)
863{
864 char *prompt_str;
865 static char the_command[MAX_LINE];
866
867 setup_prompt_string(i->promptmode, &prompt_str);
868#ifdef BB_FEATURE_COMMAND_EDITING
869 /*
870 ** enable command line editing only while a command line
871 ** is actually being read; otherwise, we'll end up bequeathing
872 ** atexit() handlers and other unwanted stuff to our
873 ** child processes (rob@sysgo.de)
874 */
875 cmdedit_read_input(prompt_str, the_command);
876 cmdedit_terminate();
877#else
878 fputs(prompt_str, stdout);
879 fflush(stdout);
880 the_command[0]=fgetc(i->file);
881 the_command[1]='\0';
882#endif
883 i->p = the_command;
884}
885
886/* This is the magic location that prints prompts
887 * and gets data back from the user */
888static int file_get(struct in_str *i)
889{
890 int ch;
891
892 ch = 0;
893 /* If there is data waiting, eat it up */
894 if (i->p && *i->p) {
895 ch=*i->p++;
896 } else {
897 /* need to double check i->file because we might be doing something
898 * more complicated by now, like sourcing or substituting. */
899 if (i->__promptme && interactive && i->file == stdin) {
900 get_user_input(i);
901 i->promptmode=2;
902 }
903 i->__promptme = 0;
904
905 if (i->p && *i->p) {
906 ch=*i->p++;
907 }
908 debug_printf("b_getch: got a %d\n", ch);
909 }
910 if (ch == '\n') i->__promptme=1;
911 return ch;
912}
913
914/* All the callers guarantee this routine will never be
915 * used right after a newline, so prompting is not needed.
916 */
917static int file_peek(struct in_str *i)
918{
919 if (i->p && *i->p) {
920 return *i->p;
921 } else {
922 static char buffer;
923 buffer = fgetc(i->file);
924 i->p = &buffer;
925 debug_printf("b_peek: got a %d\n", *i->p);
926 return *i->p;
927 }
928}
929
930static void setup_file_in_str(struct in_str *i, FILE *f)
931{
932 i->peek = file_peek;
933 i->get = file_get;
934 i->__promptme=1;
935 i->promptmode=1;
936 i->file = f;
937 i->p = NULL;
938}
939
940static void setup_string_in_str(struct in_str *i, const char *s)
941{
942 i->peek = static_peek;
943 i->get = static_get;
944 i->__promptme=1;
945 i->promptmode=1;
946 i->p = s;
947}
948
949static void mark_open(int fd)
950{
951 struct close_me *new = xmalloc(sizeof(struct close_me));
952 new->fd = fd;
953 new->next = close_me_head;
954 close_me_head = new;
955}
956
957static void mark_closed(int fd)
958{
959 struct close_me *tmp;
960 if (close_me_head == NULL || close_me_head->fd != fd)
961 error_msg_and_die("corrupt close_me");
962 tmp = close_me_head;
963 close_me_head = close_me_head->next;
964 free(tmp);
965}
966
967static void close_all()
968{
969 struct close_me *c;
970 for (c=close_me_head; c; c=c->next) {
971 close(c->fd);
972 }
973 close_me_head = NULL;
974}
975
976/* squirrel != NULL means we squirrel away copies of stdin, stdout,
977 * and stderr if they are redirected. */
978static int setup_redirects(struct child_prog *prog, int squirrel[])
979{
980 int openfd, mode;
981 struct redir_struct *redir;
982
983 for (redir=prog->redirects; redir; redir=redir->next) {
984 if (redir->dup == -1) {
985 mode=redir_table[redir->type].mode;
986 openfd = open(redir->word.gl_pathv[0], mode, 0666);
987 if (openfd < 0) {
988 /* this could get lost if stderr has been redirected, but
989 bash and ash both lose it as well (though zsh doesn't!) */
990 fprintf(stderr,"error opening %s: %s\n", redir->word.gl_pathv[0],
991 strerror(errno));
992 return 1;
993 }
994 } else {
995 openfd = redir->dup;
996 }
997
998 if (openfd != redir->fd) {
999 if (squirrel && redir->fd < 3) {
1000 squirrel[redir->fd] = dup(redir->fd);
1001 }
1002 dup2(openfd, redir->fd);
1003 close(openfd);
1004 }
1005 }
1006 return 0;
1007}
1008
1009static void restore_redirects(int squirrel[])
1010{
1011 int i, fd;
1012 for (i=0; i<3; i++) {
1013 fd = squirrel[i];
1014 if (fd != -1) {
1015 /* No error checking. I sure wouldn't know what
1016 * to do with an error if I found one! */
1017 dup2(fd, i);
1018 close(fd);
1019 }
1020 }
1021}
1022
1023/* XXX this definitely needs some more thought, work, and
1024 * cribbing from other shells */
1025static int pipe_wait(struct pipe *pi)
1026{
1027 int rcode=0, i, pid, running, status;
1028 running = pi->num_progs;
1029 while (running) {
1030 pid=waitpid(-1, &status, 0);
1031 if (pid < 0) perror_msg_and_die("waitpid");
1032 for (i=0; i < pi->num_progs; i++) {
1033 if (pi->progs[i].pid == pid) {
1034 if (i==pi->num_progs-1) rcode=WEXITSTATUS(status);
1035 pi->progs[i].pid = 0;
1036 running--;
1037 break;
1038 }
1039 }
1040 }
1041 return rcode;
1042}
1043
1044/* very simple version for testing */
1045static void pseudo_exec(struct child_prog *child)
1046{
1047 int rcode;
1048 struct built_in_command *x;
1049 if (child->argv) {
1050 /*
1051 * Check if the command matches any of the builtins.
1052 * Depending on context, this might be redundant. But it's
1053 * easier to waste a few CPU cycles than it is to figure out
1054 * if this is one of those cases.
1055 */
1056 for (x = bltins; x->cmd; x++) {
1057 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1058 debug_printf("builtin exec %s\n", child->argv[0]);
1059 exit(x->function(child));
1060 }
1061 }
1062 debug_printf("exec of %s\n",child->argv[0]);
1063 execvp(child->argv[0],child->argv);
1064 perror("execvp");
1065 exit(1);
1066 } else if (child->group) {
1067 debug_printf("runtime nesting to group\n");
1068 interactive=0; /* crucial!!!! */
1069 rcode = run_list_real(child->group);
1070 /* OK to leak memory by not calling run_list_test,
1071 * since this process is about to exit */
1072 exit(rcode);
1073 } else {
1074 /* Can happen. See what bash does with ">foo" by itself. */
1075 debug_printf("trying to pseudo_exec null command\n");
1076 exit(EXIT_SUCCESS);
1077 }
1078}
1079
1080/* run_pipe_real() starts all the jobs, but doesn't wait for anything
1081 * to finish. See pipe_wait().
1082 *
1083 * return code is normally -1, when the caller has to wait for children
1084 * to finish to determine the exit status of the pipe. If the pipe
1085 * is a simple builtin command, however, the action is done by the
1086 * time run_pipe_real returns, and the exit code is provided as the
1087 * return value.
1088 *
1089 * The input of the pipe is always stdin, the output is always
1090 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1091 * because it tries to avoid running the command substitution in
1092 * subshell, when that is in fact necessary. The subshell process
1093 * now has its stdout directed to the input of the appropriate pipe,
1094 * so this routine is noticeably simpler.
1095 */
1096static int run_pipe_real(struct pipe *pi)
1097{
1098 int i;
1099 int nextin, nextout;
1100 int pipefds[2]; /* pipefds[0] is for reading */
1101 struct child_prog *child;
1102 struct built_in_command *x;
1103
1104 nextin = 0;
1105 pi->pgrp = 0;
1106
1107 /* Check if this is a simple builtin (not part of a pipe).
1108 * Builtins within pipes have to fork anyway, and are handled in
1109 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1110 */
1111 if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1112 child = & (pi->progs[0]);
1113 if (child->group && ! child->subshell) {
1114 int squirrel[] = {-1, -1, -1};
1115 int rcode;
1116 debug_printf("non-subshell grouping\n");
1117 setup_redirects(child, squirrel);
1118 /* XXX could we merge code with following builtin case,
1119 * by creating a pseudo builtin that calls run_list_real? */
1120 rcode = run_list_real(child->group);
1121 restore_redirects(squirrel);
1122 return rcode;
1123 }
1124 for (x = bltins; x->cmd; x++) {
1125 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1126 int squirrel[] = {-1, -1, -1};
1127 int rcode;
1128 debug_printf("builtin inline %s\n", child->argv[0]);
1129 /* XXX setup_redirects acts on file descriptors, not FILEs.
1130 * This is perfect for work that comes after exec().
1131 * Is it really safe for inline use? Experimentally,
1132 * things seem to work with glibc. */
1133 setup_redirects(child, squirrel);
1134 rcode = x->function(child);
1135 restore_redirects(squirrel);
1136 return rcode;
1137 }
1138 }
1139 }
1140
1141 for (i = 0; i < pi->num_progs; i++) {
1142 child = & (pi->progs[i]);
1143
1144 /* pipes are inserted between pairs of commands */
1145 if ((i + 1) < pi->num_progs) {
1146 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1147 nextout = pipefds[1];
1148 } else {
1149 nextout=1;
1150 pipefds[0] = -1;
1151 }
1152
1153 /* XXX test for failed fork()? */
1154 if (!(child->pid = fork())) {
1155 close_all();
1156
1157 if (nextin != 0) {
1158 dup2(nextin, 0);
1159 close(nextin);
1160 }
1161 if (nextout != 1) {
1162 dup2(nextout, 1);
1163 close(nextout);
1164 }
1165 if (pipefds[0]!=-1) {
1166 close(pipefds[0]); /* opposite end of our output pipe */
1167 }
1168
1169 /* Like bash, explicit redirects override pipes,
1170 * and the pipe fd is available for dup'ing. */
1171 setup_redirects(child,NULL);
1172
1173 pseudo_exec(child);
1174 }
1175 if (interactive) {
1176 /* Put our child in the process group whose leader is the
1177 * first process in this pipe. */
1178 if (pi->pgrp==0) {
1179 pi->pgrp = child->pid;
1180 }
1181 /* Don't check for errors. The child may be dead already,
1182 * in which case setpgid returns error code EACCES. */
1183 setpgid(child->pid, pi->pgrp);
1184 }
1185 /* In the non-interactive case, do nothing. Leave the children
1186 * with the process group that they inherited from us. */
1187
1188 if (nextin != 0)
1189 close(nextin);
1190 if (nextout != 1)
1191 close(nextout);
1192
1193 /* If there isn't another process, nextin is garbage
1194 but it doesn't matter */
1195 nextin = pipefds[0];
1196 }
1197 return -1;
1198}
1199
1200static int run_list_real(struct pipe *pi)
1201{
1202 int rcode=0;
1203 int if_code=0, next_if_code=0; /* need double-buffer to handle elif */
1204 reserved_style rmode=RES_NONE;
1205 for (;pi;pi=pi->next) {
1206 rmode = pi->r_mode;
1207 debug_printf("rmode=%d if_code=%d next_if_code=%d\n", rmode, if_code, next_if_code);
1208 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1209 if (rmode == RES_THEN && if_code) continue;
1210 if (rmode == RES_ELSE && !if_code) continue;
1211 if (rmode == RES_ELIF && !if_code) continue;
1212 if (pi->num_progs == 0) break;
1213 rcode = run_pipe_real(pi);
1214 if (rcode!=-1) {
1215 /* We only ran a builtin: rcode was set by the return value
1216 * of run_pipe_real(), and we don't need to wait for anything. */
1217 } else if (pi->followup==PIPE_BG) {
1218 /* XXX check bash's behavior with nontrivial pipes */
1219 /* XXX compute jobid */
1220 /* XXX what does bash do with attempts to background builtins? */
1221 printf("[%d] %d\n", pi->jobid, pi->pgrp);
1222 last_bg_pid = pi->pgrp;
1223 rcode = EXIT_SUCCESS;
1224 } else {
1225 if (interactive) {
1226 /* move the new process group into the foreground */
1227 /* suppress messages when run from /linuxrc mag@sysgo.de */
1228 signal(SIGTTIN, SIG_IGN);
1229 signal(SIGTTOU, SIG_IGN);
1230 if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY)
1231 perror_msg("tcsetpgrp");
1232 rcode = pipe_wait(pi);
1233 if (tcsetpgrp(0, getpid()) && errno != ENOTTY)
1234 perror_msg("tcsetpgrp");
1235 signal(SIGTTIN, SIG_DFL);
1236 signal(SIGTTOU, SIG_DFL);
1237 } else {
1238 rcode = pipe_wait(pi);
1239 }
1240 }
1241 last_return_code=rcode;
1242 if ( rmode == RES_IF || rmode == RES_ELIF )
1243 next_if_code=rcode; /* can be overwritten a number of times */
1244 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1245 (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1246 return rcode; /* XXX broken if list is part of if/then/else */
1247 }
1248 return rcode;
1249}
1250
1251/* broken, of course, but OK for testing */
1252static char *indenter(int i)
1253{
1254 static char blanks[]=" ";
1255 return &blanks[sizeof(blanks)-i-1];
1256}
1257
1258/* return code is the exit status of the pipe */
1259static int run_pipe_test(struct pipe *pi, int indent)
1260{
1261 char **p;
1262 struct child_prog *child;
1263 struct redir_struct *r, *rnext;
1264 int a, i, ret_code=0;
1265 char *ind = indenter(indent);
1266 final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1267 for (i=0; i<pi->num_progs; i++) {
1268 child = &pi->progs[i];
1269 final_printf("%s command %d:\n",ind,i);
1270 if (child->argv) {
1271 for (a=0,p=child->argv; *p; a++,p++) {
1272 final_printf("%s argv[%d] = %s\n",ind,a,*p);
1273 }
1274 globfree(&child->glob_result);
1275 child->argv=NULL;
1276 } else if (child->group) {
1277 final_printf("%s begin group (subshell:%d)\n",ind, child->subshell);
1278 ret_code = run_list_test(child->group,indent+3);
1279 final_printf("%s end group\n",ind);
1280 } else {
1281 final_printf("%s (nil)\n",ind);
1282 }
1283 for (r=child->redirects; r; r=rnext) {
1284 final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1285 if (r->dup == -1) {
1286 final_printf(" %s\n", *r->word.gl_pathv);
1287 globfree(&r->word);
1288 } else {
1289 final_printf("&%d\n", r->dup);
1290 }
1291 rnext=r->next;
1292 free(r);
1293 }
1294 child->redirects=NULL;
1295 }
1296 free(pi->progs); /* children are an array, they get freed all at once */
1297 pi->progs=NULL;
1298 return ret_code;
1299}
1300
1301static int run_list_test(struct pipe *head, int indent)
1302{
1303 int rcode=0; /* if list has no members */
1304 struct pipe *pi, *next;
1305 char *ind = indenter(indent);
1306 for (pi=head; pi; pi=next) {
1307 if (pi->num_progs == 0) break;
1308 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1309 rcode = run_pipe_test(pi, indent);
1310 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1311 next=pi->next;
1312 pi->next=NULL;
1313 free(pi);
1314 }
1315 return rcode;
1316}
1317
1318/* Select which version we will use */
1319static int run_list(struct pipe *pi)
1320{
1321 int rcode=0;
1322 if (fake_mode==0) {
1323 rcode = run_list_real(pi);
1324 }
1325 /* run_list_test has the side effect of clearing memory
1326 * In the long run that function can be merged with run_list_real,
1327 * but doing that now would hobble the debugging effort. */
1328 run_list_test(pi,0);
1329 return rcode;
1330}
1331
1332/* The API for glob is arguably broken. This routine pushes a non-matching
1333 * string into the output structure, removing non-backslashed backslashes.
1334 * If someone can prove me wrong, by performing this function within the
1335 * original glob(3) api, feel free to rewrite this routine into oblivion.
1336 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1337 * XXX broken if the last character is '\\', check that before calling.
1338 */
1339static int globhack(const char *src, int flags, glob_t *pglob)
1340{
1341 int cnt, pathc;
1342 const char *s;
1343 char *dest;
1344 for (cnt=1, s=src; *s; s++) {
1345 if (*s == '\\') s++;
1346 cnt++;
1347 }
1348 dest = malloc(cnt);
1349 if (!dest) return GLOB_NOSPACE;
1350 if (!(flags & GLOB_APPEND)) {
1351 pglob->gl_pathv=NULL;
1352 pglob->gl_pathc=0;
1353 pglob->gl_offs=0;
1354 pglob->gl_offs=0;
1355 }
1356 pathc = ++pglob->gl_pathc;
1357 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1358 if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
1359 pglob->gl_pathv[pathc-1]=dest;
1360 pglob->gl_pathv[pathc]=NULL;
1361 for (s=src; *s; s++, dest++) {
1362 if (*s == '\\') s++;
1363 *dest = *s;
1364 }
1365 *dest='\0';
1366 return 0;
1367}
1368
1369/* XXX broken if the last character is '\\', check that before calling */
1370static int glob_needed(const char *s)
1371{
1372 for (; *s; s++) {
1373 if (*s == '\\') s++;
1374 if (strchr("*[?",*s)) return 1;
1375 }
1376 return 0;
1377}
1378
1379#if 0
1380static void globprint(glob_t *pglob)
1381{
1382 int i;
1383 debug_printf("glob_t at %p:\n", pglob);
1384 debug_printf(" gl_pathc=%d gl_pathv=%p gl_offs=%d gl_flags=%d\n",
1385 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
1386 for (i=0; i<pglob->gl_pathc; i++)
1387 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
1388 pglob->gl_pathv[i], pglob->gl_pathv[i]);
1389}
1390#endif
1391
1392static int xglob(o_string *dest, int flags, glob_t *pglob)
1393{
1394 int gr;
1395
1396 /* short-circuit for null word */
1397 /* we can code this better when the debug_printf's are gone */
1398 if (dest->length == 0) {
1399 if (dest->nonnull) {
1400 /* bash man page calls this an "explicit" null */
1401 gr = globhack(dest->data, flags, pglob);
1402 debug_printf("globhack returned %d\n",gr);
1403 } else {
1404 return 0;
1405 }
1406 } else if (glob_needed(dest->data)) {
1407 gr = glob(dest->data, flags, NULL, pglob);
1408 debug_printf("glob returned %d\n",gr);
1409 if (gr == GLOB_NOMATCH) {
1410 /* quote removal, or more accurately, backslash removal */
1411 gr = globhack(dest->data, flags, pglob);
1412 debug_printf("globhack returned %d\n",gr);
1413 }
1414 } else {
1415 gr = globhack(dest->data, flags, pglob);
1416 debug_printf("globhack returned %d\n",gr);
1417 }
1418 if (gr == GLOB_NOSPACE) {
1419 fprintf(stderr,"out of memory during glob\n");
1420 exit(1);
1421 }
1422 if (gr != 0) { /* GLOB_ABORTED ? */
1423 fprintf(stderr,"glob(3) error %d\n",gr);
1424 }
1425 /* globprint(glob_target); */
1426 return gr;
1427}
1428
1429/* the src parameter allows us to peek forward to a possible &n syntax
1430 * for file descriptor duplication, e.g., "2>&1".
1431 * Return code is 0 normally, 1 if a syntax error is detected in src.
1432 * Resource errors (in xmalloc) cause the process to exit */
1433static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1434 struct in_str *input)
1435{
1436 struct child_prog *child=ctx->child;
1437 struct redir_struct *redir = child->redirects;
1438 struct redir_struct *last_redir=NULL;
1439
1440 /* Create a new redir_struct and drop it onto the end of the linked list */
1441 while(redir) {
1442 last_redir=redir;
1443 redir=redir->next;
1444 }
1445 redir = xmalloc(sizeof(struct redir_struct));
1446 redir->next=NULL;
1447 if (last_redir) {
1448 last_redir->next=redir;
1449 } else {
1450 child->redirects=redir;
1451 }
1452
1453 redir->type=style;
1454 redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
1455
1456 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1457
1458 /* Check for a '2>&1' type redirect */
1459 redir->dup = redirect_dup_num(input);
1460 if (redir->dup == -2) return 1; /* syntax error */
1461 if (redir->dup != -1) {
1462 /* Erik had a check here that the file descriptor in question
1463 * is legit; I postpone that to "run time" */
1464 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
1465 } else {
1466 /* We do _not_ try to open the file that src points to,
1467 * since we need to return and let src be expanded first.
1468 * Set ctx->pending_redirect, so we know what to do at the
1469 * end of the next parsed word.
1470 */
1471 ctx->pending_redirect = redir;
1472 }
1473 return 0;
1474}
1475
1476struct pipe *new_pipe(void) {
1477 struct pipe *pi;
1478 pi = xmalloc(sizeof(struct pipe));
1479 pi->num_progs = 0;
1480 pi->progs = NULL;
1481 pi->next = NULL;
1482 pi->followup = 0; /* invalid */
1483 return pi;
1484}
1485
1486static void initialize_context(struct p_context *ctx)
1487{
1488 ctx->pipe=NULL;
1489 ctx->pending_redirect=NULL;
1490 ctx->child=NULL;
1491 ctx->list_head=new_pipe();
1492 ctx->pipe=ctx->list_head;
1493 ctx->w=RES_NONE;
1494 ctx->stack=NULL;
1495 done_command(ctx); /* creates the memory for working child */
1496}
1497
1498/* normal return is 0
1499 * if a reserved word is found, and processed, return 1
1500 * should handle if, then, elif, else, fi, for, while, until, do, done.
1501 * case, function, and select are obnoxious, save those for later.
1502 */
1503int reserved_word(o_string *dest, struct p_context *ctx)
1504{
1505 struct reserved_combo {
1506 char *literal;
1507 int code;
1508 long flag;
1509 };
1510 /* Mostly a list of accepted follow-up reserved words.
1511 * FLAG_END means we are done with the sequence, and are ready
1512 * to turn the compound list into a command.
1513 * FLAG_START means the word must start a new compound list.
1514 */
1515 static struct reserved_combo reserved_list[] = {
1516 { "if", RES_IF, FLAG_THEN | FLAG_START },
1517 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
1518 { "elif", RES_ELIF, FLAG_THEN },
1519 { "else", RES_ELSE, FLAG_FI },
1520 { "fi", RES_FI, FLAG_END },
1521 { "for", RES_FOR, FLAG_DO | FLAG_START },
1522 { "while", RES_WHILE, FLAG_DO | FLAG_START },
1523 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
1524 { "do", RES_DO, FLAG_DONE },
1525 { "done", RES_DONE, FLAG_END }
1526 };
1527 struct reserved_combo *r;
1528 for (r=reserved_list;
1529#define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
1530 r<reserved_list+NRES; r++) {
1531 if (strcmp(dest->data, r->literal) == 0) {
1532 debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
1533 if (r->flag & FLAG_START) {
1534 struct p_context *new = xmalloc(sizeof(struct p_context));
1535 debug_printf("push stack\n");
1536 *new = *ctx; /* physical copy */
1537 initialize_context(ctx);
1538 ctx->stack=new;
1539 } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
1540 syntax(); /* XXX how do we get out? */
1541 }
1542 ctx->w=r->code;
1543 ctx->old_flag = r->flag;
1544 if (ctx->old_flag & FLAG_END) {
1545 struct p_context *old;
1546 debug_printf("pop stack\n");
1547 old = ctx->stack;
1548 old->child->group = ctx->list_head;
1549 *ctx = *old; /* physical copy */
1550 free(old);
1551 ctx->w=RES_NONE;
1552 }
1553 b_reset (dest);
1554 return 1;
1555 }
1556 }
1557 return 0;
1558}
1559
1560/* normal return is 0.
1561 * Syntax or xglob errors return 1. */
1562static int done_word(o_string *dest, struct p_context *ctx)
1563{
1564 struct child_prog *child=ctx->child;
1565 glob_t *glob_target;
1566 int gr, flags = 0;
1567
1568 debug_printf("done_word: %s %p\n", dest->data, child);
1569 if (dest->length == 0 && !dest->nonnull) {
1570 debug_printf(" true null, ignored\n");
1571 return 0;
1572 }
1573 if (ctx->pending_redirect) {
1574 glob_target = &ctx->pending_redirect->word;
1575 } else {
1576 if (child->group) {
1577 syntax();
1578 return 1; /* syntax error, groups and arglists don't mix */
1579 }
1580 if (!child->argv) {
1581 debug_printf("checking %s for reserved-ness\n",dest->data);
1582 if (reserved_word(dest,ctx)) return 0;
1583 }
1584 glob_target = &child->glob_result;
1585 if (child->argv) flags |= GLOB_APPEND;
1586 }
1587 gr = xglob(dest, flags, glob_target);
1588 if (gr != 0) return 1;
1589
1590 b_reset(dest);
1591 if (ctx->pending_redirect) {
1592 ctx->pending_redirect=NULL;
1593 if (glob_target->gl_pathc != 1) {
1594 fprintf(stderr, "ambiguous redirect\n");
1595 return 1;
1596 }
1597 } else {
1598 child->argv = glob_target->gl_pathv;
1599 }
1600 return 0;
1601}
1602
1603/* The only possible error here is out of memory, in which case
1604 * xmalloc exits. */
1605static int done_command(struct p_context *ctx)
1606{
1607 /* The child is really already in the pipe structure, so
1608 * advance the pipe counter and make a new, null child.
1609 * Only real trickiness here is that the uncommitted
1610 * child structure, to which ctx->child points, is not
1611 * counted in pi->num_progs. */
1612 struct pipe *pi=ctx->pipe;
1613 struct child_prog *prog=ctx->child;
1614
1615 if (prog && prog->group == NULL
1616 && prog->argv == NULL
1617 && prog->redirects == NULL) {
1618 debug_printf("done_command: skipping null command\n");
1619 return 0;
1620 } else if (prog) {
1621 pi->num_progs++;
1622 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
1623 } else {
1624 debug_printf("done_command: initializing\n");
1625 }
1626 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
1627
1628 prog = pi->progs + pi->num_progs;
1629 prog->redirects = NULL;
1630 prog->argv = NULL;
1631 prog->is_stopped = 0;
1632 prog->group = NULL;
1633 prog->glob_result.gl_pathv = NULL;
1634 prog->family = pi;
1635
1636 ctx->child=prog;
1637 /* but ctx->pipe and ctx->list_head remain unchanged */
1638 return 0;
1639}
1640
1641static int done_pipe(struct p_context *ctx, pipe_style type)
1642{
1643 struct pipe *new_p;
1644 done_command(ctx); /* implicit closure of previous command */
1645 debug_printf("done_pipe, type %d\n", type);
1646 ctx->pipe->followup = type;
1647 ctx->pipe->r_mode = ctx->w;
1648 new_p=new_pipe();
1649 ctx->pipe->next = new_p;
1650 ctx->pipe = new_p;
1651 ctx->child = NULL;
1652 done_command(ctx); /* set up new pipe to accept commands */
1653 return 0;
1654}
1655
1656/* peek ahead in the in_str to find out if we have a "&n" construct,
1657 * as in "2>&1", that represents duplicating a file descriptor.
1658 * returns either -2 (syntax error), -1 (no &), or the number found.
1659 */
1660static int redirect_dup_num(struct in_str *input)
1661{
1662 int ch, d=0, ok=0;
1663 ch = b_peek(input);
1664 if (ch != '&') return -1;
1665
1666 b_getch(input); /* get the & */
1667 while (ch=b_peek(input),isdigit(ch)) {
1668 d = d*10+(ch-'0');
1669 ok=1;
1670 b_getch(input);
1671 }
1672 if (ok) return d;
1673
1674 fprintf(stderr, "ambiguous redirect\n");
1675 return -2;
1676}
1677
1678/* If a redirect is immediately preceded by a number, that number is
1679 * supposed to tell which file descriptor to redirect. This routine
1680 * looks for such preceding numbers. In an ideal world this routine
1681 * needs to handle all the following classes of redirects...
1682 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
1683 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
1684 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
1685 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
1686 * A -1 output from this program means no valid number was found, so the
1687 * caller should use the appropriate default for this redirection.
1688 */
1689static int redirect_opt_num(o_string *o)
1690{
1691 int num;
1692
1693 if (o->length==0) return -1;
1694 for(num=0; num<o->length; num++) {
1695 if (!isdigit(*(o->data+num))) {
1696 return -1;
1697 }
1698 }
1699 /* reuse num (and save an int) */
1700 num=atoi(o->data);
1701 b_reset(o);
1702 return num;
1703}
1704
1705FILE *generate_stream_from_list(struct pipe *head)
1706{
1707 FILE *pf;
1708#if 1
1709 int pid, channel[2];
1710 if (pipe(channel)<0) perror_msg_and_die("pipe");
1711 pid=fork();
1712 if (pid<0) {
1713 perror_msg_and_die("fork");
1714 } else if (pid==0) {
1715 close(channel[0]);
1716 if (channel[1] != 1) {
1717 dup2(channel[1],1);
1718 close(channel[1]);
1719 }
1720#if 0
1721#define SURROGATE "surrogate response"
1722 write(1,SURROGATE,sizeof(SURROGATE));
1723 exit(run_list(head));
1724#else
1725 exit(run_list_real(head)); /* leaks memory */
1726#endif
1727 }
1728 debug_printf("forked child %d\n",pid);
1729 close(channel[1]);
1730 pf = fdopen(channel[0],"r");
1731 debug_printf("pipe on FILE *%p\n",pf);
1732#else
1733 run_list_test(head,0);
1734 pf=popen("echo surrogate response","r");
1735 debug_printf("started fake pipe on FILE *%p\n",pf);
1736#endif
1737 return pf;
1738}
1739
1740/* this version hacked for testing purposes */
1741/* return code is exit status of the process that is run. */
1742static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
1743{
1744 int retcode;
1745 o_string result=NULL_O_STRING;
1746 struct p_context inner;
1747 FILE *p;
1748 struct in_str pipe_str;
1749 initialize_context(&inner);
1750
1751 /* recursion to generate command */
1752 retcode = parse_stream(&result, &inner, input, subst_end);
1753 if (retcode != 0) return retcode; /* syntax error or EOF */
1754 done_word(&result, &inner);
1755 done_pipe(&inner, PIPE_SEQ);
1756 b_free(&result);
1757
1758 p=generate_stream_from_list(inner.list_head);
1759 if (p==NULL) return 1;
1760 mark_open(fileno(p));
1761 setup_file_in_str(&pipe_str, p);
1762
1763 /* now send results of command back into original context */
1764 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
1765 /* XXX In case of a syntax error, should we try to kill the child?
1766 * That would be tough to do right, so just read until EOF. */
1767 if (retcode == 1) {
1768 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
1769 }
1770
1771 debug_printf("done reading from pipe, pclose()ing\n");
1772 /* This is the step that wait()s for the child. Should be pretty
1773 * safe, since we just read an EOF from its stdout. We could try
1774 * to better, by using wait(), and keeping track of background jobs
1775 * at the same time. That would be a lot of work, and contrary
1776 * to the KISS philosophy of this program. */
1777 mark_closed(fileno(p));
1778 retcode=pclose(p);
1779 debug_printf("pclosed, retcode=%d\n",retcode);
1780 /* XXX this process fails to trim a single trailing newline */
1781 return retcode;
1782}
1783
1784static int parse_group(o_string *dest, struct p_context *ctx,
1785 struct in_str *input, int ch)
1786{
1787 int rcode, endch=0;
1788 struct p_context sub;
1789 struct child_prog *child = ctx->child;
1790 if (child->argv) {
1791 syntax();
1792 return 1; /* syntax error, groups and arglists don't mix */
1793 }
1794 initialize_context(&sub);
1795 switch(ch) {
1796 case '(': endch=')'; child->subshell=1; break;
1797 case '{': endch='}'; break;
1798 default: syntax(); /* really logic error */
1799 }
1800 rcode=parse_stream(dest,&sub,input,endch);
1801 done_word(dest,&sub); /* finish off the final word in the subcontext */
1802 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
1803 child->group = sub.list_head;
1804 return rcode;
1805 /* child remains "open", available for possible redirects */
1806}
1807
1808/* basically useful version until someone wants to get fancier,
1809 * see the bash man page under "Parameter Expansion" */
1810static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src)
1811{
1812 const char *p=NULL;
1813 if (src->data) p = getenv(src->data);
1814 if (p) parse_string(dest, ctx, p); /* recursion */
1815 b_free(src);
1816}
1817
1818/* return code: 0 for OK, 1 for syntax error */
1819static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
1820{
1821 int i, advance=0;
1822 o_string alt=NULL_O_STRING;
1823 char sep[]=" ";
1824 int ch = input->peek(input); /* first character after the $ */
1825 debug_printf("handle_dollar: ch=%c\n",ch);
1826 if (isalpha(ch)) {
1827 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
1828 b_getch(input);
1829 b_addchr(&alt,ch);
1830 }
1831 lookup_param(dest, ctx, &alt);
1832 } else if (isdigit(ch)) {
1833 i = ch-'0'; /* XXX is $0 special? */
1834 if (i<global_argc) {
1835 parse_string(dest, ctx, global_argv[i]); /* recursion */
1836 }
1837 advance = 1;
1838 } else switch (ch) {
1839 case '$':
1840 b_adduint(dest,getpid());
1841 advance = 1;
1842 break;
1843 case '!':
1844 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
1845 advance = 1;
1846 break;
1847 case '?':
1848 b_adduint(dest,last_return_code);
1849 advance = 1;
1850 break;
1851 case '#':
1852 b_adduint(dest,global_argc ? global_argc-1 : 0);
1853 advance = 1;
1854 break;
1855 case '{':
1856 b_getch(input);
1857 /* XXX maybe someone will try to escape the '}' */
1858 while(ch=b_getch(input),ch!=EOF && ch!='}') {
1859 b_addchr(&alt,ch);
1860 }
1861 if (ch != '}') {
1862 syntax();
1863 return 1;
1864 }
1865 lookup_param(dest, ctx, &alt);
1866 break;
1867 case '(':
1868 process_command_subs(dest, ctx, input, ')');
1869 break;
1870 case '*':
1871 sep[0]=ifs[0];
1872 for (i=1; i<global_argc; i++) {
1873 parse_string(dest, ctx, global_argv[i]);
1874 if (i+1 < global_argc) parse_string(dest, ctx, sep);
1875 }
1876 break;
1877 case '@':
1878 case '-':
1879 case '_':
1880 /* still unhandled, but should be eventually */
1881 fprintf(stderr,"unhandled syntax: $%c\n",ch);
1882 return 1;
1883 break;
1884 default:
1885 b_addqchr(dest,'$',dest->quote);
1886 }
1887 /* Eat the character if the flag was set. If the compiler
1888 * is smart enough, we could substitute "b_getch(input);"
1889 * for all the "advance = 1;" above, and also end up with
1890 * a nice size-optimized program. Hah! That'll be the day.
1891 */
1892 if (advance) b_getch(input);
1893 return 0;
1894}
1895
1896int parse_string(o_string *dest, struct p_context *ctx, const char *src)
1897{
1898 struct in_str foo;
1899 setup_string_in_str(&foo, src);
1900 return parse_stream(dest, ctx, &foo, '\0');
1901}
1902
1903/* return code is 0 for normal exit, 1 for syntax error */
1904int parse_stream(o_string *dest, struct p_context *ctx,
1905 struct in_str *input, int end_trigger)
1906{
1907 unsigned int ch, m;
1908 int redir_fd;
1909 redir_type redir_style;
1910 int next;
1911
1912 /* Only double-quote state is handled in the state variable dest->quote.
1913 * A single-quote triggers a bypass of the main loop until its mate is
1914 * found. When recursing, quote state is passed in via dest->quote. */
1915
1916 debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
1917 while ((ch=b_getch(input))!=EOF) {
1918 m = map[ch];
1919 next = (ch == '\n') ? 0 : b_peek(input);
1920 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
1921 ch,ch,m,dest->quote);
1922 if (m==0 || ((m==1 || m==2) && dest->quote)) {
1923 b_addqchr(dest, ch, dest->quote);
1924 } else if (ch == end_trigger && !dest->quote) {
1925 debug_printf("leaving parse_stream\n");
1926 return 0;
1927 } else if (m==2 && !dest->quote) { /* IFS */
1928 done_word(dest, ctx);
1929#if 0
1930 if (ch=='\n') {
1931 /* Yahoo! Time to run with it! */
1932 done_pipe(ctx,PIPE_SEQ);
1933 run_list(ctx->list_head);
1934 initialize_context(ctx);
1935 }
1936#endif
1937 } else switch (ch) {
1938 case '#':
1939 if (dest->length == 0 && !dest->quote) {
1940 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
1941 } else {
1942 b_addqchr(dest, ch, dest->quote);
1943 }
1944 break;
1945 case '\\':
1946 if (next == EOF) {
1947 syntax();
1948 return 1;
1949 }
1950 b_addqchr(dest, '\\', dest->quote);
1951 b_addqchr(dest, b_getch(input), dest->quote);
1952 break;
1953 case '$':
1954 if (handle_dollar(dest, ctx, input)!=0) return 1;
1955 break;
1956 case '\'':
1957 dest->nonnull = 1;
1958 while(ch=b_getch(input),ch!=EOF && ch!='\'') {
1959 b_addchr(dest,ch);
1960 }
1961 if (ch==EOF) {
1962 syntax();
1963 return 1;
1964 }
1965 break;
1966 case '"':
1967 dest->nonnull = 1;
1968 dest->quote = !dest->quote;
1969 break;
1970 case '`':
1971 process_command_subs(dest, ctx, input, '`');
1972 break;
1973 case '>':
1974 redir_fd = redirect_opt_num(dest);
1975 done_word(dest, ctx);
1976 redir_style=REDIRECT_OVERWRITE;
1977 if (next == '>') {
1978 redir_style=REDIRECT_APPEND;
1979 b_getch(input);
1980 } else if (next == '(') {
1981 syntax(); /* until we support >(list) Process Substitution */
1982 return 1;
1983 }
1984 setup_redirect(ctx, redir_fd, redir_style, input);
1985 break;
1986 case '<':
1987 redir_fd = redirect_opt_num(dest);
1988 done_word(dest, ctx);
1989 redir_style=REDIRECT_INPUT;
1990 if (next == '<') {
1991 redir_style=REDIRECT_HEREIS;
1992 b_getch(input);
1993 } else if (next == '>') {
1994 redir_style=REDIRECT_IO;
1995 b_getch(input);
1996 } else if (next == '(') {
1997 syntax(); /* until we support <(list) Process Substitution */
1998 return 1;
1999 }
2000 setup_redirect(ctx, redir_fd, redir_style, input);
2001 break;
2002 case ';':
2003 done_word(dest, ctx);
2004 done_pipe(ctx,PIPE_SEQ);
2005 break;
2006 case '&':
2007 done_word(dest, ctx);
2008 if (next=='&') {
2009 b_getch(input);
2010 done_pipe(ctx,PIPE_AND);
2011 } else {
2012 done_pipe(ctx,PIPE_BG);
2013 }
2014 break;
2015 case '|':
2016 done_word(dest, ctx);
2017 if (next=='|') {
2018 b_getch(input);
2019 done_pipe(ctx,PIPE_OR);
2020 } else {
2021 /* we could pick up a file descriptor choice here
2022 * with redirect_opt_num(), but bash doesn't do it.
2023 * "echo foo 2| cat" yields "foo 2". */
2024 done_command(ctx);
2025 }
2026 break;
2027 case '(':
2028 case '{':
2029 if (parse_group(dest, ctx, input, ch)!=0) return 1;
2030 break;
2031 case ')':
2032 case '}':
2033 syntax(); /* Proper use of this character caught by end_trigger */
2034 return 1;
2035 break;
2036 default:
2037 syntax(); /* this is really an internal logic error */
2038 return 1;
2039 }
2040 }
2041 /* complain if quote? No, maybe we just finished a command substitution
2042 * that was quoted. Example:
2043 * $ echo "`cat foo` plus more"
2044 * and we just got the EOF generated by the subshell that ran "cat foo"
2045 * The only real complaint is if we got an EOF when end_trigger != '\0',
2046 * that is, we were really supposed to get end_trigger, and never got
2047 * one before the EOF. Can't use the standard "syntax error" return code,
2048 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
2049 if (end_trigger != '\0') return -1;
2050 return 0;
2051}
2052
2053void mapset(const unsigned char *set, int code)
2054{
2055 const unsigned char *s;
2056 for (s=set; *s; s++) map[*s] = code;
2057}
2058
2059void update_ifs_map(void)
2060{
2061 /* char *ifs and char map[256] are both globals. */
2062 ifs = getenv("IFS");
2063 if (ifs == NULL) ifs=" \t\n";
2064 /* Precompute a list of 'flow through' behavior so it can be treated
2065 * quickly up front. Computation is necessary because of IFS.
2066 * Special case handling of IFS == " \t\n" is not implemented.
2067 * The map[] array only really needs two bits each, and on most machines
2068 * that would be faster because of the reduced L1 cache footprint.
2069 */
2070 memset(map,0,256); /* most characters flow through always */
2071 mapset("\\$'\"`", 3); /* never flow through */
2072 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2073 mapset(ifs, 2); /* also flow through if quoted */
2074}
2075
2076/* most recursion does not come through here, the exeception is
2077 * from builtin_source() */
2078int parse_stream_outer(struct in_str *inp)
2079{
2080
2081 struct p_context ctx;
2082 o_string temp=NULL_O_STRING;
2083 int rcode;
2084 do {
2085 initialize_context(&ctx);
2086 update_ifs_map();
2087 inp->promptmode=1;
2088 rcode = parse_stream(&temp, &ctx, inp, '\n');
2089 done_word(&temp, &ctx);
2090 done_pipe(&ctx,PIPE_SEQ);
2091 run_list(ctx.list_head);
2092 } while (rcode != -1); /* loop on syntax errors, return on EOF */
2093 return 0;
2094}
2095
2096static int parse_string_outer(const char *s)
2097{
2098 struct in_str input;
2099 setup_string_in_str(&input, s);
2100 return parse_stream_outer(&input);
2101}
2102
2103static int parse_file_outer(FILE *f)
2104{
2105 int rcode;
2106 struct in_str input;
2107 setup_file_in_str(&input, f);
2108 rcode = parse_stream_outer(&input);
2109 return rcode;
2110}
2111
2112int shell_main(int argc, char **argv)
2113{
2114 int opt;
2115 FILE *input;
2116
2117 /* XXX what should these be while sourcing /etc/profile? */
2118 global_argc = argc;
2119 global_argv = argv;
2120
2121 if (argv[0] && argv[0][0] == '-') {
2122 debug_printf("\nsourcing /etc/profile\n");
2123 input = xfopen("/etc/profile", "r");
2124 mark_open(fileno(input));
2125 parse_file_outer(input);
2126 mark_closed(fileno(input));
2127 fclose(input);
2128 }
2129 input=stdin;
2130
2131 /* initialize the cwd -- this is never freed...*/
2132 cwd = xgetcwd(0);
2133#ifdef BB_FEATURE_COMMAND_EDITING
2134 cmdedit_set_initial_prompt();
2135#else
2136 PS1 = NULL;
2137#endif
2138
2139 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2140 switch (opt) {
2141 case 'c':
2142 {
2143 global_argv = argv+optind;
2144 global_argc = argc-optind;
2145 opt = parse_string_outer(optarg);
2146 exit(opt);
2147 }
2148 break;
2149 case 'i':
2150 interactive++;
2151 break;
2152 case 'f':
2153 fake_mode++;
2154 break;
2155 default:
2156 fprintf(stderr, "Usage: sh [FILE]...\n"
2157 " or: sh -c command [args]...\n\n");
2158 exit(EXIT_FAILURE);
2159 }
2160 }
2161 /* A shell is interactive if the `-i' flag was given, or if all of
2162 * the following conditions are met:
2163 * no -c command
2164 * no arguments remaining or the -s flag given
2165 * standard input is a terminal
2166 * standard output is a terminal
2167 * Refer to Posix.2, the description of the `sh' utility. */
2168 if (argv[optind]==NULL && input==stdin &&
2169 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
2170 interactive++;
2171 }
2172
2173 if (interactive) {
2174 /* Looks like they want an interactive shell */
2175 fprintf(stdout, "\nhush -- the humble shell v0.01 (testing)\n\n");
2176 exit(parse_file_outer(stdin));
2177 }
2178 debug_printf("\ninteractive=%d\n", interactive);
2179
2180 debug_printf("\nrunning script '%s'\n", argv[optind]);
2181 global_argv = argv+optind;
2182 global_argc = argc-optind;
2183 input = xfopen(argv[optind], "r");
2184 opt = parse_file_outer(input);
2185
2186#ifdef BB_FEATURE_CLEAN_UP
2187 fclose(input.file);
2188#endif
2189
2190 return(opt);
2191}
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-03-24 00:47:20 +0000