blob: a58da189cabdbcdcbe7a49acd072a00ea70b4abb [file] [log] [blame]
Eric Andersen25f27032001-04-26 23:22:31 +00001/* 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
Eric Andersen78a7c992001-05-15 16:30:25 +000046 * aliases
Eric Andersen25f27032001-04-26 23:22:31 +000047 * Arithmetic Expansion
48 * <(list) and >(list) Process Substitution
Eric Andersen83a2ae22001-05-07 17:59:25 +000049 * reserved words: case, esac, select, function
Eric Andersen25f27032001-04-26 23:22:31 +000050 * Here Documents ( << word )
51 * Functions
52 * Major bugs:
53 * job handling woefully incomplete and buggy
54 * reserved word execution woefully incomplete and buggy
Eric Andersen25f27032001-04-26 23:22:31 +000055 * to-do:
Eric Andersen83a2ae22001-05-07 17:59:25 +000056 * 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
Eric Andersen25f27032001-04-26 23:22:31 +000061 * handle children going into background
62 * clean up recognition of null pipes
Eric Andersen25f27032001-04-26 23:22:31 +000063 * check setting of global_argc and global_argv
64 * control-C handling, probably with longjmp
Eric Andersen25f27032001-04-26 23:22:31 +000065 * follow IFS rules more precisely, including update semantics
Eric Andersen25f27032001-04-26 23:22:31 +000066 * 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
Eric Andersen78a7c992001-05-15 16:30:25 +000072 * document how quoting rules not precisely followed for variable assignments
Eric Andersen25f27032001-04-26 23:22:31 +000073 * maybe change map[] to use 2-bit entries
74 * (eventually) remove all the printf's
Eric Andersen25f27032001-04-26 23:22:31 +000075 *
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
Eric Andersen83a2ae22001-05-07 17:59:25 +0000101#include <sys/stat.h> /* ulimit */
Eric Andersen25f27032001-04-26 23:22:31 +0000102#include <sys/types.h>
103#include <sys/wait.h>
104#include <signal.h>
105
106/* #include <dmalloc.h> */
Eric Andersen4ed5e372001-05-01 01:49:50 +0000107/* #define DEBUG_SHELL */
Eric Andersen25f27032001-04-26 23:22:31 +0000108
109#ifdef BB_VER
110#include "busybox.h"
111#include "cmdedit.h"
112#else
Eric Andersen25f27032001-04-26 23:22:31 +0000113#define applet_name "hush"
Eric Andersenaf44a0e2001-04-27 07:26:12 +0000114#include "standalone.h"
Eric Andersen25f27032001-04-26 23:22:31 +0000115#define shell_main main
Eric Andersen004015e2001-05-21 20:30:51 +0000116#undef BB_FEATURE_SH_FANCY_PROMPT
Eric Andersenaf44a0e2001-04-27 07:26:12 +0000117#endif
Eric Andersen25f27032001-04-26 23:22:31 +0000118
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,
Eric Andersenaf44a0e2001-04-27 07:26:12 +0000158 RES_XXXX = 11,
159 RES_SNTX = 12
Eric Andersen25f27032001-04-26 23:22:31 +0000160} 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 */
Eric Andersen25f27032001-04-26 23:22:31 +0000218};
219
220struct jobset {
221 struct pipe *head; /* head of list of running jobs */
222 struct pipe *fg; /* current foreground job */
223};
224
225struct close_me {
226 int fd;
227 struct close_me *next;
228};
229
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000230struct variables {
231 char *name;
232 char *value;
233 int flg_export;
234 int flg_read_only;
235 struct variables *next;
236};
237
Eric Andersen25f27032001-04-26 23:22:31 +0000238/* globals, connect us to the outside world
239 * the first three support $?, $#, and $1 */
240char **global_argv;
241unsigned int global_argc;
242unsigned int last_return_code;
243extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
244
245/* Variables we export */
246unsigned int shell_context; /* Used in cmdedit.c to reset the
247 * context when someone hits ^C */
248
249/* "globals" within this file */
Eric Andersenbc604a22001-05-16 05:24:03 +0000250static char *ifs;
Eric Andersen25f27032001-04-26 23:22:31 +0000251static char map[256];
Eric Andersenbc604a22001-05-16 05:24:03 +0000252static int fake_mode;
253static int interactive;
254static struct close_me *close_me_head;
Eric Andersencfa88ec2001-05-11 18:08:16 +0000255static const char *cwd;
Eric Andersenbafd94f2001-05-02 16:11:59 +0000256static struct jobset *job_list;
Eric Andersenbc604a22001-05-16 05:24:03 +0000257static unsigned int last_bg_pid;
Eric Andersen25f27032001-04-26 23:22:31 +0000258static char *PS1;
Eric Andersen94ac2442001-05-22 19:05:18 +0000259static char *PS2;
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000260struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000261struct variables *top_vars = &shell_ver;
Eric Andersen25f27032001-04-26 23:22:31 +0000262
263#define B_CHUNK (100)
264#define B_NOSPAC 1
Eric Andersen25f27032001-04-26 23:22:31 +0000265
266typedef struct {
267 char *data;
268 int length;
269 int maxlen;
270 int quote;
271 int nonnull;
272} o_string;
273#define NULL_O_STRING {NULL,0,0,0,0}
274/* used for initialization:
275 o_string foo = NULL_O_STRING; */
276
277/* I can almost use ordinary FILE *. Is open_memstream() universally
278 * available? Where is it documented? */
279struct in_str {
280 const char *p;
Matt Kraaibdd4ece2001-05-23 17:43:00 +0000281 char peek_buf[2];
Eric Andersen25f27032001-04-26 23:22:31 +0000282 int __promptme;
283 int promptmode;
284 FILE *file;
285 int (*get) (struct in_str *);
286 int (*peek) (struct in_str *);
287};
288#define b_getch(input) ((input)->get(input))
289#define b_peek(input) ((input)->peek(input))
290
291#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
292
293struct built_in_command {
294 char *cmd; /* name */
295 char *descr; /* description */
296 int (*function) (struct child_prog *); /* function ptr */
297};
298
299/* belongs in busybox.h */
300static inline int max(int a, int b) {
301 return (a>b)?a:b;
302}
303
304/* This should be in utility.c */
305#ifdef DEBUG_SHELL
306static void debug_printf(const char *format, ...)
307{
308 va_list args;
309 va_start(args, format);
310 vfprintf(stderr, format, args);
311 va_end(args);
312}
313#else
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000314static inline void debug_printf(const char *format, ...) { }
Eric Andersen25f27032001-04-26 23:22:31 +0000315#endif
316#define final_printf debug_printf
317
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000318static void __syntax(char *file, int line) {
319 error_msg("syntax error %s:%d", file, line);
Eric Andersen25f27032001-04-26 23:22:31 +0000320}
321#define syntax() __syntax(__FILE__, __LINE__)
322
323/* Index of subroutines: */
324/* function prototypes for builtins */
325static int builtin_cd(struct child_prog *child);
326static int builtin_env(struct child_prog *child);
327static int builtin_exec(struct child_prog *child);
328static int builtin_exit(struct child_prog *child);
329static int builtin_export(struct child_prog *child);
330static int builtin_fg_bg(struct child_prog *child);
331static int builtin_help(struct child_prog *child);
332static int builtin_jobs(struct child_prog *child);
333static int builtin_pwd(struct child_prog *child);
334static int builtin_read(struct child_prog *child);
Eric Andersenf72f5622001-05-15 23:21:41 +0000335static int builtin_set(struct child_prog *child);
Eric Andersen25f27032001-04-26 23:22:31 +0000336static int builtin_shift(struct child_prog *child);
337static int builtin_source(struct child_prog *child);
Eric Andersen25f27032001-04-26 23:22:31 +0000338static int builtin_umask(struct child_prog *child);
339static int builtin_unset(struct child_prog *child);
Eric Andersen83a2ae22001-05-07 17:59:25 +0000340static int builtin_not_written(struct child_prog *child);
Eric Andersen25f27032001-04-26 23:22:31 +0000341/* o_string manipulation: */
342static int b_check_space(o_string *o, int len);
343static int b_addchr(o_string *o, int ch);
344static void b_reset(o_string *o);
345static int b_addqchr(o_string *o, int ch, int quote);
346static int b_adduint(o_string *o, unsigned int i);
347/* in_str manipulations: */
348static int static_get(struct in_str *i);
349static int static_peek(struct in_str *i);
350static int file_get(struct in_str *i);
351static int file_peek(struct in_str *i);
352static void setup_file_in_str(struct in_str *i, FILE *f);
353static void setup_string_in_str(struct in_str *i, const char *s);
354/* close_me manipulations: */
355static void mark_open(int fd);
356static void mark_closed(int fd);
357static void close_all();
358/* "run" the final data structures: */
359static char *indenter(int i);
Eric Andersenbf7df042001-05-23 22:18:35 +0000360static int free_pipe_list(struct pipe *head, int indent);
361static int free_pipe(struct pipe *pi, int indent);
Eric Andersen25f27032001-04-26 23:22:31 +0000362/* really run the final data structures: */
363static int setup_redirects(struct child_prog *prog, int squirrel[]);
364static int pipe_wait(struct pipe *pi);
365static int run_list_real(struct pipe *pi);
366static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
Eric Andersenada18ff2001-05-21 16:18:22 +0000367int controlling_tty(int check_pgrp);
Eric Andersen25f27032001-04-26 23:22:31 +0000368static int run_pipe_real(struct pipe *pi);
369/* extended glob support: */
370static int globhack(const char *src, int flags, glob_t *pglob);
371static int glob_needed(const char *s);
372static int xglob(o_string *dest, int flags, glob_t *pglob);
Eric Andersen78a7c992001-05-15 16:30:25 +0000373/* variable assignment: */
Eric Andersen78a7c992001-05-15 16:30:25 +0000374static int is_assignment(const char *s);
Eric Andersen25f27032001-04-26 23:22:31 +0000375/* data structure manipulation: */
376static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
377static void initialize_context(struct p_context *ctx);
378static int done_word(o_string *dest, struct p_context *ctx);
379static int done_command(struct p_context *ctx);
380static int done_pipe(struct p_context *ctx, pipe_style type);
381/* primary string parsing: */
382static int redirect_dup_num(struct in_str *input);
383static int redirect_opt_num(o_string *o);
384static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
385static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
386static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src);
387static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
388static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
389static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
390/* setup: */
391static int parse_stream_outer(struct in_str *inp);
392static int parse_string_outer(const char *s);
393static int parse_file_outer(FILE *f);
Eric Andersenbafd94f2001-05-02 16:11:59 +0000394/* job management: */
395static void checkjobs();
396static void insert_bg_job(struct pipe *pi);
397static void remove_bg_job(struct pipe *pi);
Eric Andersenf72f5622001-05-15 23:21:41 +0000398/* local variable support */
399static char *get_local_var(const char *var);
Eric Andersenf72f5622001-05-15 23:21:41 +0000400static void unset_local_var(const char *name);
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000401static int set_local_var(const char *s, int flg_export);
Eric Andersenf72f5622001-05-15 23:21:41 +0000402
Eric Andersen25f27032001-04-26 23:22:31 +0000403
404/* Table of built-in functions. They can be forked or not, depending on
405 * context: within pipes, they fork. As simple commands, they do not.
406 * When used in non-forking context, they can change global variables
407 * in the parent shell process. If forked, of course they can not.
408 * For example, 'unset foo | whatever' will parse and run, but foo will
409 * still be set at the end. */
410static struct built_in_command bltins[] = {
411 {"bg", "Resume a job in the background", builtin_fg_bg},
Eric Andersen83a2ae22001-05-07 17:59:25 +0000412 {"break", "Exit for, while or until loop", builtin_not_written},
Eric Andersen25f27032001-04-26 23:22:31 +0000413 {"cd", "Change working directory", builtin_cd},
Eric Andersen83a2ae22001-05-07 17:59:25 +0000414 {"continue", "Continue for, while or until loop", builtin_not_written},
Eric Andersen25f27032001-04-26 23:22:31 +0000415 {"env", "Print all environment variables", builtin_env},
Eric Andersen83a2ae22001-05-07 17:59:25 +0000416 {"eval", "Construct and run shell command", builtin_not_written},
Eric Andersenf72f5622001-05-15 23:21:41 +0000417 {"exec", "Exec command, replacing this shell with the exec'd process",
418 builtin_exec},
Eric Andersen25f27032001-04-26 23:22:31 +0000419 {"exit", "Exit from shell()", builtin_exit},
420 {"export", "Set environment variable", builtin_export},
421 {"fg", "Bring job into the foreground", builtin_fg_bg},
422 {"jobs", "Lists the active jobs", builtin_jobs},
423 {"pwd", "Print current directory", builtin_pwd},
424 {"read", "Input environment variable", builtin_read},
Eric Andersen83a2ae22001-05-07 17:59:25 +0000425 {"return", "Return from a function", builtin_not_written},
Eric Andersenf72f5622001-05-15 23:21:41 +0000426 {"set", "Set/unset shell local variables", builtin_set},
Eric Andersen25f27032001-04-26 23:22:31 +0000427 {"shift", "Shift positional parameters", builtin_shift},
Eric Andersen83a2ae22001-05-07 17:59:25 +0000428 {"trap", "Trap signals", builtin_not_written},
429 {"ulimit","Controls resource limits", builtin_not_written},
Eric Andersen25f27032001-04-26 23:22:31 +0000430 {"umask","Sets file creation mask", builtin_umask},
431 {"unset", "Unset environment variable", builtin_unset},
432 {".", "Source-in and run commands in a file", builtin_source},
433 {"help", "List shell built-in commands", builtin_help},
434 {NULL, NULL, NULL}
435};
436
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000437static const char *set_cwd(void)
438{
439 if(cwd==unknown)
440 cwd = NULL; /* xgetcwd(arg) called free(arg) */
441 cwd = xgetcwd((char *)cwd);
442 if (!cwd)
443 cwd = unknown;
444 return cwd;
445}
446
447
Eric Andersen25f27032001-04-26 23:22:31 +0000448/* built-in 'cd <path>' handler */
449static int builtin_cd(struct child_prog *child)
450{
451 char *newdir;
452 if (child->argv[1] == NULL)
453 newdir = getenv("HOME");
454 else
455 newdir = child->argv[1];
456 if (chdir(newdir)) {
457 printf("cd: %s: %s\n", newdir, strerror(errno));
458 return EXIT_FAILURE;
459 }
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000460 set_cwd();
Eric Andersen25f27032001-04-26 23:22:31 +0000461 return EXIT_SUCCESS;
462}
463
464/* built-in 'env' handler */
465static int builtin_env(struct child_prog *dummy)
466{
467 char **e = environ;
468 if (e == NULL) return EXIT_FAILURE;
469 for (; *e; e++) {
470 puts(*e);
471 }
472 return EXIT_SUCCESS;
473}
474
475/* built-in 'exec' handler */
476static int builtin_exec(struct child_prog *child)
477{
478 if (child->argv[1] == NULL)
479 return EXIT_SUCCESS; /* Really? */
480 child->argv++;
481 pseudo_exec(child);
482 /* never returns */
483}
484
485/* built-in 'exit' handler */
486static int builtin_exit(struct child_prog *child)
487{
488 if (child->argv[1] == NULL)
Eric Andersene67c3ce2001-05-02 02:09:36 +0000489 exit(last_return_code);
Eric Andersen25f27032001-04-26 23:22:31 +0000490 exit (atoi(child->argv[1]));
491}
492
493/* built-in 'export VAR=value' handler */
494static int builtin_export(struct child_prog *child)
495{
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000496 int res = 0;
497 char *name = child->argv[1];
Eric Andersen25f27032001-04-26 23:22:31 +0000498
Eric Andersenf72f5622001-05-15 23:21:41 +0000499 if (name == NULL) {
Eric Andersen25f27032001-04-26 23:22:31 +0000500 return (builtin_env(child));
501 }
Eric Andersenf72f5622001-05-15 23:21:41 +0000502
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000503 name = strdup(name);
Eric Andersenf72f5622001-05-15 23:21:41 +0000504
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000505 if(name) {
Eric Andersen94ac2442001-05-22 19:05:18 +0000506 char *value = strchr(name, '=');
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000507
Eric Andersen94ac2442001-05-22 19:05:18 +0000508 if (!value) {
509 char *tmp;
510 /* They are exporting something without an =VALUE */
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000511
Eric Andersen94ac2442001-05-22 19:05:18 +0000512 value = get_local_var(name);
513 if (value) {
514 size_t ln = strlen(name);
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000515
Eric Andersen94ac2442001-05-22 19:05:18 +0000516 tmp = realloc(name, ln+strlen(value)+2);
517 if(tmp==NULL)
518 res = -1;
519 else {
520 sprintf(tmp+ln, "=%s", value);
521 name = tmp;
522 }
523 } else {
524 /* bash does not return an error when trying to export
525 * an undefined variable. Do likewise. */
526 res = 1;
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000527 }
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000528 }
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000529 }
530 if (res<0)
Eric Andersenf72f5622001-05-15 23:21:41 +0000531 perror_msg("export");
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000532 else if(res==0)
533 res = set_local_var(name, 1);
534 else
535 res = 0;
536 free(name);
537 return res;
Eric Andersen25f27032001-04-26 23:22:31 +0000538}
539
540/* built-in 'fg' and 'bg' handler */
541static int builtin_fg_bg(struct child_prog *child)
542{
Eric Andersen0fcd4472001-05-02 20:12:03 +0000543 int i, jobnum;
544 struct pipe *pi=NULL;
Eric Andersen25f27032001-04-26 23:22:31 +0000545
Eric Andersen0fcd4472001-05-02 20:12:03 +0000546 /* If they gave us no args, assume they want the last backgrounded task */
547 if (!child->argv[1]) {
548 for (pi = job_list->head; pi; pi = pi->next) {
549 if (pi->progs && pi->progs->pid == last_bg_pid) {
550 break;
551 }
552 }
553 if (!pi) {
554 error_msg("%s: no current job", child->argv[0]);
555 return EXIT_FAILURE;
556 }
557 } else {
558 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
559 error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
560 return EXIT_FAILURE;
561 }
Eric Andersen25f27032001-04-26 23:22:31 +0000562
Eric Andersen0fcd4472001-05-02 20:12:03 +0000563 for (pi = job_list->head; pi; pi = pi->next) {
564 if (pi->jobid == jobnum) {
565 break;
566 }
567 }
568 if (!pi) {
569 error_msg("%s: %d: no such job", child->argv[0], jobnum);
570 return EXIT_FAILURE;
Eric Andersen25f27032001-04-26 23:22:31 +0000571 }
572 }
Eric Andersen25f27032001-04-26 23:22:31 +0000573 if (*child->argv[0] == 'f') {
574 /* Make this job the foreground job */
Eric Andersen0fcd4472001-05-02 20:12:03 +0000575 signal(SIGTTOU, SIG_IGN);
Eric Andersen25f27032001-04-26 23:22:31 +0000576 /* suppress messages when run from /linuxrc mag@sysgo.de */
Eric Andersen0fcd4472001-05-02 20:12:03 +0000577 if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY)
Eric Andersenada18ff2001-05-21 16:18:22 +0000578 perror_msg("tcsetpgrp-1");
Eric Andersen0fcd4472001-05-02 20:12:03 +0000579 signal(SIGTTOU, SIG_DFL);
580 job_list->fg = pi;
Eric Andersen25f27032001-04-26 23:22:31 +0000581 }
582
583 /* Restart the processes in the job */
Eric Andersen0fcd4472001-05-02 20:12:03 +0000584 for (i = 0; i < pi->num_progs; i++)
585 pi->progs[i].is_stopped = 0;
Eric Andersen25f27032001-04-26 23:22:31 +0000586
Eric Andersen0fcd4472001-05-02 20:12:03 +0000587 kill(-pi->pgrp, SIGCONT);
Eric Andersen25f27032001-04-26 23:22:31 +0000588
Eric Andersen0fcd4472001-05-02 20:12:03 +0000589 pi->stopped_progs = 0;
Eric Andersen25f27032001-04-26 23:22:31 +0000590 return EXIT_SUCCESS;
591}
592
593/* built-in 'help' handler */
594static int builtin_help(struct child_prog *dummy)
595{
596 struct built_in_command *x;
597
598 printf("\nBuilt-in commands:\n");
599 printf("-------------------\n");
600 for (x = bltins; x->cmd; x++) {
601 if (x->descr==NULL)
602 continue;
603 printf("%s\t%s\n", x->cmd, x->descr);
604 }
605 printf("\n\n");
606 return EXIT_SUCCESS;
607}
608
609/* built-in 'jobs' handler */
610static int builtin_jobs(struct child_prog *child)
611{
612 struct pipe *job;
613 char *status_string;
614
Eric Andersenbafd94f2001-05-02 16:11:59 +0000615 for (job = job_list->head; job; job = job->next) {
Eric Andersen25f27032001-04-26 23:22:31 +0000616 if (job->running_progs == job->stopped_progs)
617 status_string = "Stopped";
618 else
619 status_string = "Running";
620 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
621 }
622 return EXIT_SUCCESS;
623}
624
625
626/* built-in 'pwd' handler */
627static int builtin_pwd(struct child_prog *dummy)
628{
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000629 puts(set_cwd());
Eric Andersen25f27032001-04-26 23:22:31 +0000630 return EXIT_SUCCESS;
631}
632
633/* built-in 'read VAR' handler */
634static int builtin_read(struct child_prog *child)
635{
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000636 int res;
Eric Andersen25f27032001-04-26 23:22:31 +0000637
638 if (child->argv[1]) {
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000639 char string[BUFSIZ];
640 char *var = 0;
Eric Andersen25f27032001-04-26 23:22:31 +0000641
Eric Andersen94ac2442001-05-22 19:05:18 +0000642 string[0] = 0; /* In case stdin has only EOF */
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000643 /* read string */
644 fgets(string, sizeof(string), stdin);
645 chomp(string);
646 var = malloc(strlen(child->argv[1])+strlen(string)+2);
647 if(var) {
648 sprintf(var, "%s=%s", child->argv[1], string);
649 res = set_local_var(var, 0);
650 } else
Eric Andersen94ac2442001-05-22 19:05:18 +0000651 res = -1;
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000652 if (res)
653 fprintf(stderr, "read: %m\n");
Eric Andersen94ac2442001-05-22 19:05:18 +0000654 free(var); /* So not move up to avoid breaking errno */
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000655 return res;
656 } else {
657 do res=getchar(); while(res!='\n' && res!=EOF);
658 return 0;
659 }
Eric Andersen25f27032001-04-26 23:22:31 +0000660}
661
Eric Andersenf72f5622001-05-15 23:21:41 +0000662/* built-in 'set VAR=value' handler */
663static int builtin_set(struct child_prog *child)
664{
Eric Andersenf72f5622001-05-15 23:21:41 +0000665 char *temp = child->argv[1];
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000666 struct variables *e;
Eric Andersenf72f5622001-05-15 23:21:41 +0000667
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000668 if (temp == NULL)
669 for(e = top_vars; e; e=e->next)
670 printf("%s=%s\n", e->name, e->value);
671 else
672 set_local_var(temp, 0);
673
Eric Andersenf72f5622001-05-15 23:21:41 +0000674 return EXIT_SUCCESS;
Eric Andersenf72f5622001-05-15 23:21:41 +0000675}
676
677
Eric Andersen25f27032001-04-26 23:22:31 +0000678/* Built-in 'shift' handler */
679static int builtin_shift(struct child_prog *child)
680{
681 int n=1;
682 if (child->argv[1]) {
683 n=atoi(child->argv[1]);
684 }
685 if (n>=0 && n<global_argc) {
686 /* XXX This probably breaks $0 */
687 global_argc -= n;
688 global_argv += n;
689 return EXIT_SUCCESS;
690 } else {
691 return EXIT_FAILURE;
692 }
693}
694
695/* Built-in '.' handler (read-in and execute commands from file) */
696static int builtin_source(struct child_prog *child)
697{
698 FILE *input;
699 int status;
700
701 if (child->argv[1] == NULL)
702 return EXIT_FAILURE;
703
704 /* XXX search through $PATH is missing */
705 input = fopen(child->argv[1], "r");
706 if (!input) {
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000707 error_msg("Couldn't open file '%s'", child->argv[1]);
Eric Andersen25f27032001-04-26 23:22:31 +0000708 return EXIT_FAILURE;
709 }
710
711 /* Now run the file */
712 /* XXX argv and argc are broken; need to save old global_argv
713 * (pointer only is OK!) on this stack frame,
714 * set global_argv=child->argv+1, recurse, and restore. */
715 mark_open(fileno(input));
716 status = parse_file_outer(input);
717 mark_closed(fileno(input));
718 fclose(input);
719 return (status);
720}
721
Eric Andersen25f27032001-04-26 23:22:31 +0000722static int builtin_umask(struct child_prog *child)
723{
Eric Andersen83a2ae22001-05-07 17:59:25 +0000724 mode_t new_umask;
725 const char *arg = child->argv[1];
726 char *end;
727 if (arg) {
728 new_umask=strtoul(arg, &end, 8);
729 if (*end!='\0' || end == arg) {
730 return EXIT_FAILURE;
731 }
732 } else {
733 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
734 }
735 umask(new_umask);
736 return EXIT_SUCCESS;
Eric Andersen25f27032001-04-26 23:22:31 +0000737}
738
739/* built-in 'unset VAR' handler */
740static int builtin_unset(struct child_prog *child)
741{
Eric Andersen9ffb7dd2001-05-19 03:00:46 +0000742 /* bash returned already true */
Eric Andersenf72f5622001-05-15 23:21:41 +0000743 unset_local_var(child->argv[1]);
Eric Andersen25f27032001-04-26 23:22:31 +0000744 return EXIT_SUCCESS;
745}
746
Eric Andersen83a2ae22001-05-07 17:59:25 +0000747static int builtin_not_written(struct child_prog *child)
748{
749 printf("builtin_%s not written\n",child->argv[0]);
750 return EXIT_FAILURE;
751}
752
Eric Andersen25f27032001-04-26 23:22:31 +0000753static int b_check_space(o_string *o, int len)
754{
755 /* It would be easy to drop a more restrictive policy
756 * in here, such as setting a maximum string length */
757 if (o->length + len > o->maxlen) {
758 char *old_data = o->data;
759 /* assert (data == NULL || o->maxlen != 0); */
760 o->maxlen += max(2*len, B_CHUNK);
761 o->data = realloc(o->data, 1 + o->maxlen);
762 if (o->data == NULL) {
763 free(old_data);
764 }
765 }
766 return o->data == NULL;
767}
768
769static int b_addchr(o_string *o, int ch)
770{
771 debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
772 if (b_check_space(o, 1)) return B_NOSPAC;
773 o->data[o->length] = ch;
774 o->length++;
775 o->data[o->length] = '\0';
776 return 0;
777}
778
779static void b_reset(o_string *o)
780{
781 o->length = 0;
782 o->nonnull = 0;
783 if (o->data != NULL) *o->data = '\0';
784}
785
786static void b_free(o_string *o)
787{
788 b_reset(o);
789 if (o->data != NULL) free(o->data);
790 o->data = NULL;
791 o->maxlen = 0;
792}
793
794/* My analysis of quoting semantics tells me that state information
795 * is associated with a destination, not a source.
796 */
797static int b_addqchr(o_string *o, int ch, int quote)
798{
799 if (quote && strchr("*?[\\",ch)) {
800 int rc;
801 rc = b_addchr(o, '\\');
802 if (rc) return rc;
803 }
804 return b_addchr(o, ch);
805}
806
807/* belongs in utility.c */
808char *simple_itoa(unsigned int i)
809{
810 /* 21 digits plus null terminator, good for 64-bit or smaller ints */
811 static char local[22];
812 char *p = &local[21];
813 *p-- = '\0';
814 do {
815 *p-- = '0' + i % 10;
816 i /= 10;
817 } while (i > 0);
818 return p + 1;
819}
820
821static int b_adduint(o_string *o, unsigned int i)
822{
823 int r;
824 char *p = simple_itoa(i);
825 /* no escape checking necessary */
826 do r=b_addchr(o, *p++); while (r==0 && *p);
827 return r;
828}
829
830static int static_get(struct in_str *i)
831{
832 int ch=*i->p++;
833 if (ch=='\0') return EOF;
834 return ch;
835}
836
837static int static_peek(struct in_str *i)
838{
839 return *i->p;
840}
841
842static inline void cmdedit_set_initial_prompt(void)
843{
Eric Andersen004015e2001-05-21 20:30:51 +0000844#ifndef BB_FEATURE_SH_FANCY_PROMPT
Eric Andersen25f27032001-04-26 23:22:31 +0000845 PS1 = NULL;
846#else
847 PS1 = getenv("PS1");
848 if(PS1==0)
849 PS1 = "\\w \\$ ";
850#endif
851}
852
853static inline void setup_prompt_string(int promptmode, char **prompt_str)
854{
Eric Andersenaf44a0e2001-04-27 07:26:12 +0000855 debug_printf("setup_prompt_string %d ",promptmode);
Eric Andersen004015e2001-05-21 20:30:51 +0000856#ifndef BB_FEATURE_SH_FANCY_PROMPT
Eric Andersen25f27032001-04-26 23:22:31 +0000857 /* Set up the prompt */
858 if (promptmode == 1) {
859 if (PS1)
860 free(PS1);
861 PS1=xmalloc(strlen(cwd)+4);
862 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# ");
863 *prompt_str = PS1;
864 } else {
865 *prompt_str = PS2;
866 }
867#else
868 *prompt_str = (promptmode==0)? PS1 : PS2;
Eric Andersenaf44a0e2001-04-27 07:26:12 +0000869#endif
870 debug_printf("result %s\n",*prompt_str);
Eric Andersen25f27032001-04-26 23:22:31 +0000871}
872
873static void get_user_input(struct in_str *i)
874{
875 char *prompt_str;
Eric Andersen088875f2001-04-27 07:49:41 +0000876 static char the_command[BUFSIZ];
Eric Andersen25f27032001-04-26 23:22:31 +0000877
878 setup_prompt_string(i->promptmode, &prompt_str);
879#ifdef BB_FEATURE_COMMAND_EDITING
880 /*
881 ** enable command line editing only while a command line
882 ** is actually being read; otherwise, we'll end up bequeathing
883 ** atexit() handlers and other unwanted stuff to our
884 ** child processes (rob@sysgo.de)
885 */
886 cmdedit_read_input(prompt_str, the_command);
887 cmdedit_terminate();
888#else
889 fputs(prompt_str, stdout);
890 fflush(stdout);
891 the_command[0]=fgetc(i->file);
892 the_command[1]='\0';
893#endif
Eric Andersen4f6753e2001-05-31 17:17:12 +0000894 fflush(stdout);
Eric Andersen25f27032001-04-26 23:22:31 +0000895 i->p = the_command;
896}
897
898/* This is the magic location that prints prompts
899 * and gets data back from the user */
900static int file_get(struct in_str *i)
901{
902 int ch;
903
904 ch = 0;
905 /* If there is data waiting, eat it up */
906 if (i->p && *i->p) {
907 ch=*i->p++;
908 } else {
909 /* need to double check i->file because we might be doing something
910 * more complicated by now, like sourcing or substituting. */
911 if (i->__promptme && interactive && i->file == stdin) {
Eric Andersen4f6753e2001-05-31 17:17:12 +0000912 while(! i->p || (interactive && strlen(i->p)==0) ) {
913 get_user_input(i);
914 }
Eric Andersen25f27032001-04-26 23:22:31 +0000915 i->promptmode=2;
Eric Andersene67c3ce2001-05-02 02:09:36 +0000916 i->__promptme = 0;
917 if (i->p && *i->p) {
918 ch=*i->p++;
919 }
Eric Andersen4ed5e372001-05-01 01:49:50 +0000920 } else {
Eric Andersene67c3ce2001-05-02 02:09:36 +0000921 ch = fgetc(i->file);
Eric Andersen25f27032001-04-26 23:22:31 +0000922 }
Eric Andersen4ed5e372001-05-01 01:49:50 +0000923
Eric Andersen25f27032001-04-26 23:22:31 +0000924 debug_printf("b_getch: got a %d\n", ch);
925 }
926 if (ch == '\n') i->__promptme=1;
927 return ch;
928}
929
930/* All the callers guarantee this routine will never be
931 * used right after a newline, so prompting is not needed.
932 */
933static int file_peek(struct in_str *i)
934{
935 if (i->p && *i->p) {
936 return *i->p;
937 } else {
Matt Kraaibdd4ece2001-05-23 17:43:00 +0000938 i->peek_buf[0] = fgetc(i->file);
939 i->peek_buf[1] = '\0';
940 i->p = i->peek_buf;
Eric Andersen25f27032001-04-26 23:22:31 +0000941 debug_printf("b_peek: got a %d\n", *i->p);
Matt Kraaibdd4ece2001-05-23 17:43:00 +0000942 return *i->p;
Eric Andersen25f27032001-04-26 23:22:31 +0000943 }
944}
945
946static void setup_file_in_str(struct in_str *i, FILE *f)
947{
948 i->peek = file_peek;
949 i->get = file_get;
950 i->__promptme=1;
951 i->promptmode=1;
952 i->file = f;
953 i->p = NULL;
954}
955
956static void setup_string_in_str(struct in_str *i, const char *s)
957{
958 i->peek = static_peek;
959 i->get = static_get;
960 i->__promptme=1;
961 i->promptmode=1;
962 i->p = s;
963}
964
965static void mark_open(int fd)
966{
967 struct close_me *new = xmalloc(sizeof(struct close_me));
968 new->fd = fd;
969 new->next = close_me_head;
970 close_me_head = new;
971}
972
973static void mark_closed(int fd)
974{
975 struct close_me *tmp;
976 if (close_me_head == NULL || close_me_head->fd != fd)
977 error_msg_and_die("corrupt close_me");
978 tmp = close_me_head;
979 close_me_head = close_me_head->next;
980 free(tmp);
981}
982
983static void close_all()
984{
985 struct close_me *c;
986 for (c=close_me_head; c; c=c->next) {
987 close(c->fd);
988 }
989 close_me_head = NULL;
990}
991
992/* squirrel != NULL means we squirrel away copies of stdin, stdout,
993 * and stderr if they are redirected. */
994static int setup_redirects(struct child_prog *prog, int squirrel[])
995{
996 int openfd, mode;
997 struct redir_struct *redir;
998
999 for (redir=prog->redirects; redir; redir=redir->next) {
1000 if (redir->dup == -1) {
1001 mode=redir_table[redir->type].mode;
1002 openfd = open(redir->word.gl_pathv[0], mode, 0666);
1003 if (openfd < 0) {
1004 /* this could get lost if stderr has been redirected, but
1005 bash and ash both lose it as well (though zsh doesn't!) */
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001006 perror_msg("error opening %s", redir->word.gl_pathv[0]);
Eric Andersen25f27032001-04-26 23:22:31 +00001007 return 1;
1008 }
1009 } else {
1010 openfd = redir->dup;
1011 }
1012
1013 if (openfd != redir->fd) {
1014 if (squirrel && redir->fd < 3) {
1015 squirrel[redir->fd] = dup(redir->fd);
1016 }
Eric Andersen83a2ae22001-05-07 17:59:25 +00001017 if (openfd == -3) {
1018 close(openfd);
1019 } else {
1020 dup2(openfd, redir->fd);
Matt Kraaic616e532001-06-05 16:50:08 +00001021 if (redir->dup == -1)
1022 close (openfd);
Eric Andersen83a2ae22001-05-07 17:59:25 +00001023 }
Eric Andersen25f27032001-04-26 23:22:31 +00001024 }
1025 }
1026 return 0;
1027}
1028
1029static void restore_redirects(int squirrel[])
1030{
1031 int i, fd;
1032 for (i=0; i<3; i++) {
1033 fd = squirrel[i];
1034 if (fd != -1) {
1035 /* No error checking. I sure wouldn't know what
1036 * to do with an error if I found one! */
1037 dup2(fd, i);
1038 close(fd);
1039 }
1040 }
1041}
1042
1043/* XXX this definitely needs some more thought, work, and
1044 * cribbing from other shells */
1045static int pipe_wait(struct pipe *pi)
1046{
1047 int rcode=0, i, pid, running, status;
1048 running = pi->num_progs;
1049 while (running) {
1050 pid=waitpid(-1, &status, 0);
1051 if (pid < 0) perror_msg_and_die("waitpid");
1052 for (i=0; i < pi->num_progs; i++) {
1053 if (pi->progs[i].pid == pid) {
1054 if (i==pi->num_progs-1) rcode=WEXITSTATUS(status);
1055 pi->progs[i].pid = 0;
1056 running--;
1057 break;
1058 }
1059 }
1060 }
1061 return rcode;
1062}
1063
Eric Andersenada18ff2001-05-21 16:18:22 +00001064/* never returns */
Eric Andersen94ac2442001-05-22 19:05:18 +00001065/* XXX no exit() here. If you don't exec, use _exit instead.
1066 * The at_exit handlers apparently confuse the calling process,
1067 * in particular stdin handling. Not sure why? */
Eric Andersen25f27032001-04-26 23:22:31 +00001068static void pseudo_exec(struct child_prog *child)
1069{
Eric Andersen78a7c992001-05-15 16:30:25 +00001070 int i, rcode;
Eric Andersen25f27032001-04-26 23:22:31 +00001071 struct built_in_command *x;
1072 if (child->argv) {
Eric Andersen78a7c992001-05-15 16:30:25 +00001073 for (i=0; is_assignment(child->argv[i]); i++) {
Eric Andersenada18ff2001-05-21 16:18:22 +00001074 debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
Eric Andersen78a7c992001-05-15 16:30:25 +00001075 putenv(strdup(child->argv[i]));
1076 }
1077 child->argv+=i; /* XXX this hack isn't so horrible, since we are about
1078 to exit, and therefore don't need to keep data
1079 structures consistent for free() use. */
1080 /* If a variable is assigned in a forest, and nobody listens,
1081 * was it ever really set?
1082 */
Eric Andersen94ac2442001-05-22 19:05:18 +00001083 if (child->argv[0] == NULL) {
1084 _exit(EXIT_SUCCESS);
1085 }
Eric Andersen78a7c992001-05-15 16:30:25 +00001086
Eric Andersen25f27032001-04-26 23:22:31 +00001087 /*
1088 * Check if the command matches any of the builtins.
1089 * Depending on context, this might be redundant. But it's
1090 * easier to waste a few CPU cycles than it is to figure out
1091 * if this is one of those cases.
1092 */
1093 for (x = bltins; x->cmd; x++) {
1094 if (strcmp(child->argv[0], x->cmd) == 0 ) {
1095 debug_printf("builtin exec %s\n", child->argv[0]);
Eric Andersen57e6a492001-05-22 22:34:51 +00001096 rcode = x->function(child);
1097 fflush(stdout);
1098 _exit(rcode);
Eric Andersen25f27032001-04-26 23:22:31 +00001099 }
1100 }
Eric Andersenaac75e52001-04-30 18:18:45 +00001101
1102 /* Check if the command matches any busybox internal commands
1103 * ("applets") here.
1104 * FIXME: This feature is not 100% safe, since
1105 * BusyBox is not fully reentrant, so we have no guarantee the things
1106 * from the .bss are still zeroed, or that things from .data are still
1107 * at their defaults. We could exec ourself from /proc/self/exe, but I
1108 * really dislike relying on /proc for things. We could exec ourself
1109 * from global_argv[0], but if we are in a chroot, we may not be able
1110 * to find ourself... */
1111#ifdef BB_FEATURE_SH_STANDALONE_SHELL
1112 {
1113 int argc_l;
1114 char** argv_l=child->argv;
1115 char *name = child->argv[0];
1116
1117#ifdef BB_FEATURE_SH_APPLETS_ALWAYS_WIN
1118 /* Following discussions from November 2000 on the busybox mailing
1119 * list, the default configuration, (without
1120 * get_last_path_component()) lets the user force use of an
1121 * external command by specifying the full (with slashes) filename.
1122 * If you enable BB_FEATURE_SH_APPLETS_ALWAYS_WIN, then applets
1123 * _aways_ override external commands, so if you want to run
1124 * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1125 * filesystem and is _not_ busybox. Some systems may want this,
1126 * most do not. */
1127 name = get_last_path_component(name);
1128#endif
1129 /* Count argc for use in a second... */
1130 for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1131 optind = 1;
1132 debug_printf("running applet %s\n", name);
1133 run_applet_by_name(name, argc_l, child->argv);
Eric Andersenaac75e52001-04-30 18:18:45 +00001134 }
1135#endif
Eric Andersen25f27032001-04-26 23:22:31 +00001136 debug_printf("exec of %s\n",child->argv[0]);
1137 execvp(child->argv[0],child->argv);
Eric Andersenada18ff2001-05-21 16:18:22 +00001138 perror_msg("couldn't exec: %s",child->argv[0]);
Eric Andersen94ac2442001-05-22 19:05:18 +00001139 _exit(1);
Eric Andersen25f27032001-04-26 23:22:31 +00001140 } else if (child->group) {
1141 debug_printf("runtime nesting to group\n");
1142 interactive=0; /* crucial!!!! */
1143 rcode = run_list_real(child->group);
Eric Andersenbf7df042001-05-23 22:18:35 +00001144 /* OK to leak memory by not calling free_pipe_list,
Eric Andersen25f27032001-04-26 23:22:31 +00001145 * since this process is about to exit */
Eric Andersen94ac2442001-05-22 19:05:18 +00001146 _exit(rcode);
Eric Andersen25f27032001-04-26 23:22:31 +00001147 } else {
1148 /* Can happen. See what bash does with ">foo" by itself. */
1149 debug_printf("trying to pseudo_exec null command\n");
Eric Andersen94ac2442001-05-22 19:05:18 +00001150 _exit(EXIT_SUCCESS);
Eric Andersen25f27032001-04-26 23:22:31 +00001151 }
1152}
1153
Eric Andersenbafd94f2001-05-02 16:11:59 +00001154static void insert_bg_job(struct pipe *pi)
1155{
1156 struct pipe *thejob;
1157
1158 /* Linear search for the ID of the job to use */
1159 pi->jobid = 1;
1160 for (thejob = job_list->head; thejob; thejob = thejob->next)
1161 if (thejob->jobid >= pi->jobid)
1162 pi->jobid = thejob->jobid + 1;
1163
1164 /* add thejob to the list of running jobs */
1165 if (!job_list->head) {
1166 thejob = job_list->head = xmalloc(sizeof(*thejob));
1167 } else {
1168 for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
1169 thejob->next = xmalloc(sizeof(*thejob));
1170 thejob = thejob->next;
1171 }
1172
1173 /* physically copy the struct job */
Eric Andersen0fcd4472001-05-02 20:12:03 +00001174 memcpy(thejob, pi, sizeof(struct pipe));
Eric Andersenbafd94f2001-05-02 16:11:59 +00001175 thejob->next = NULL;
1176 thejob->running_progs = thejob->num_progs;
1177 thejob->stopped_progs = 0;
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001178 thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
Eric Andersen1a6d39b2001-05-08 05:11:54 +00001179
1180 //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
1181 {
1182 char *bar=thejob->text;
1183 char **foo=pi->progs[0].argv;
1184 while(foo && *foo) {
1185 bar += sprintf(bar, "%s ", *foo++);
1186 }
1187 }
Eric Andersenbafd94f2001-05-02 16:11:59 +00001188
1189 /* we don't wait for background thejobs to return -- append it
1190 to the list of backgrounded thejobs and leave it alone */
Eric Andersen1a6d39b2001-05-08 05:11:54 +00001191 printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1192 last_bg_pid = thejob->progs[0].pid;
Eric Andersenbafd94f2001-05-02 16:11:59 +00001193}
1194
1195/* remove a backgrounded job from a jobset */
1196static void remove_bg_job(struct pipe *pi)
1197{
1198 struct pipe *prev_pipe;
1199
Eric Andersenbafd94f2001-05-02 16:11:59 +00001200 if (pi == job_list->head) {
1201 job_list->head = pi->next;
1202 } else {
1203 prev_pipe = job_list->head;
1204 while (prev_pipe->next != pi)
1205 prev_pipe = prev_pipe->next;
1206 prev_pipe->next = pi->next;
1207 }
1208
Eric Andersenbf7df042001-05-23 22:18:35 +00001209 free_pipe(pi, 0);
Eric Andersenbafd94f2001-05-02 16:11:59 +00001210 free(pi);
1211}
1212
Eric Andersenbafd94f2001-05-02 16:11:59 +00001213/* Checks to see if any background processes have exited -- if they
1214 have, figure out why and see if a job has completed */
1215static void checkjobs()
1216{
Eric Andersenada18ff2001-05-21 16:18:22 +00001217 int status, ctty;
Eric Andersenbafd94f2001-05-02 16:11:59 +00001218 int prognum = 0;
1219 struct pipe *pi;
1220 pid_t childpid;
1221
1222 while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
1223 for (pi = job_list->head; pi; pi = pi->next) {
1224 prognum = 0;
1225 while (prognum < pi->num_progs &&
1226 pi->progs[prognum].pid != childpid) prognum++;
1227 if (prognum < pi->num_progs)
1228 break;
1229 }
1230
Eric Andersen99785762001-05-22 21:37:48 +00001231 if(pi==NULL) {
1232 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1233 continue;
1234 }
Eric Andersenaeb44c42001-05-22 20:29:00 +00001235
Eric Andersenbafd94f2001-05-02 16:11:59 +00001236 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1237 /* child exited */
1238 pi->running_progs--;
1239 pi->progs[prognum].pid = 0;
1240
1241 if (!pi->running_progs) {
1242 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1243 remove_bg_job(pi);
1244 }
1245 } else {
1246 /* child stopped */
1247 pi->stopped_progs++;
1248 pi->progs[prognum].is_stopped = 1;
1249
1250 if (pi->stopped_progs == pi->num_progs) {
Eric Andersen1a6d39b2001-05-08 05:11:54 +00001251 printf(JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
Eric Andersenbafd94f2001-05-02 16:11:59 +00001252 }
1253 }
1254 }
1255
Matt Kraai80abc452001-05-02 21:48:17 +00001256 if (childpid == -1 && errno != ECHILD)
1257 perror_msg("waitpid");
1258
Eric Andersenbafd94f2001-05-02 16:11:59 +00001259 /* move the shell to the foreground */
Eric Andersenada18ff2001-05-21 16:18:22 +00001260 if (interactive && (ctty=controlling_tty(0))!=-1) {
1261 if (tcsetpgrp(ctty, getpgrp()))
1262 perror_msg("tcsetpgrp-2");
1263 }
1264}
1265
1266/* Figure out our controlling tty, checking in order stderr,
1267 * stdin, and stdout. If check_pgrp is set, also check that
1268 * we belong to the foreground process group associated with
1269 * that tty. The value of ctty is needed in order to call
1270 * tcsetpgrp(ctty, ...); */
1271int controlling_tty(int check_pgrp)
1272{
1273 pid_t curpgrp;
1274 int ctty;
1275
1276 if ((curpgrp = tcgetpgrp(ctty = 2)) < 0
1277 && (curpgrp = tcgetpgrp(ctty = 0)) < 0
1278 && (curpgrp = tcgetpgrp(ctty = 1)) < 0)
1279 return errno = ENOTTY, -1;
1280
1281 if (check_pgrp && curpgrp != getpgrp())
1282 return errno = EPERM, -1;
1283
1284 return ctty;
Eric Andersenbafd94f2001-05-02 16:11:59 +00001285}
1286
Eric Andersen25f27032001-04-26 23:22:31 +00001287/* run_pipe_real() starts all the jobs, but doesn't wait for anything
1288 * to finish. See pipe_wait().
1289 *
1290 * return code is normally -1, when the caller has to wait for children
1291 * to finish to determine the exit status of the pipe. If the pipe
1292 * is a simple builtin command, however, the action is done by the
1293 * time run_pipe_real returns, and the exit code is provided as the
1294 * return value.
1295 *
1296 * The input of the pipe is always stdin, the output is always
1297 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1298 * because it tries to avoid running the command substitution in
1299 * subshell, when that is in fact necessary. The subshell process
1300 * now has its stdout directed to the input of the appropriate pipe,
1301 * so this routine is noticeably simpler.
1302 */
1303static int run_pipe_real(struct pipe *pi)
1304{
1305 int i;
Eric Andersen0fcd4472001-05-02 20:12:03 +00001306 int ctty;
Eric Andersen25f27032001-04-26 23:22:31 +00001307 int nextin, nextout;
1308 int pipefds[2]; /* pipefds[0] is for reading */
1309 struct child_prog *child;
1310 struct built_in_command *x;
1311
Eric Andersen0fcd4472001-05-02 20:12:03 +00001312 ctty = -1;
Eric Andersen25f27032001-04-26 23:22:31 +00001313 nextin = 0;
Eric Andersenada18ff2001-05-21 16:18:22 +00001314 pi->pgrp = -1;
Eric Andersen25f27032001-04-26 23:22:31 +00001315
Eric Andersen0fcd4472001-05-02 20:12:03 +00001316 /* Check if we are supposed to run in the foreground */
Eric Andersen2dcfba72001-05-04 22:13:37 +00001317 if (interactive && pi->followup!=PIPE_BG) {
Eric Andersenada18ff2001-05-21 16:18:22 +00001318 if ((ctty = controlling_tty(pi->pgrp<0)) < 0) return -1;
Eric Andersen0fcd4472001-05-02 20:12:03 +00001319 }
1320
Eric Andersen25f27032001-04-26 23:22:31 +00001321 /* Check if this is a simple builtin (not part of a pipe).
1322 * Builtins within pipes have to fork anyway, and are handled in
1323 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1324 */
1325 if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1326 child = & (pi->progs[0]);
1327 if (child->group && ! child->subshell) {
1328 int squirrel[] = {-1, -1, -1};
1329 int rcode;
1330 debug_printf("non-subshell grouping\n");
1331 setup_redirects(child, squirrel);
1332 /* XXX could we merge code with following builtin case,
1333 * by creating a pseudo builtin that calls run_list_real? */
1334 rcode = run_list_real(child->group);
1335 restore_redirects(squirrel);
1336 return rcode;
1337 }
Eric Andersen78a7c992001-05-15 16:30:25 +00001338 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1339 if (i!=0 && child->argv[i]==NULL) {
1340 /* assignments, but no command: set the local environment */
1341 for (i=0; child->argv[i]!=NULL; i++) {
Eric Andersen99785762001-05-22 21:37:48 +00001342
1343 /* Ok, this case is tricky. We have to decide if this is a
1344 * local variable, or an already exported variable. If it is
1345 * already exported, we have to export the new value. If it is
1346 * not exported, we need only set this as a local variable.
1347 * This junk is all to decide whether or not to export this
1348 * variable. */
1349 int export_me=0;
1350 char *name, *value;
1351 name = strdup(child->argv[i]);
1352 value = strchr(name, '=');
1353 if (value)
1354 *value=0;
1355 if ( get_local_var(name)) {
1356 export_me=1;
1357 }
1358 free(name);
1359 set_local_var(child->argv[i], export_me);
Eric Andersen78a7c992001-05-15 16:30:25 +00001360 }
1361 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1362 }
Eric Andersen25f27032001-04-26 23:22:31 +00001363 for (x = bltins; x->cmd; x++) {
Eric Andersen78a7c992001-05-15 16:30:25 +00001364 if (strcmp(child->argv[i], x->cmd) == 0 ) {
Eric Andersen25f27032001-04-26 23:22:31 +00001365 int squirrel[] = {-1, -1, -1};
1366 int rcode;
Eric Andersen78a7c992001-05-15 16:30:25 +00001367 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
Eric Andersen83a2ae22001-05-07 17:59:25 +00001368 debug_printf("magic exec\n");
1369 setup_redirects(child,NULL);
1370 return EXIT_SUCCESS;
1371 }
Eric Andersen25f27032001-04-26 23:22:31 +00001372 debug_printf("builtin inline %s\n", child->argv[0]);
1373 /* XXX setup_redirects acts on file descriptors, not FILEs.
1374 * This is perfect for work that comes after exec().
1375 * Is it really safe for inline use? Experimentally,
1376 * things seem to work with glibc. */
1377 setup_redirects(child, squirrel);
Eric Andersen78a7c992001-05-15 16:30:25 +00001378 for (i=0; is_assignment(child->argv[i]); i++) {
1379 putenv(strdup(child->argv[i]));
1380 }
1381 child->argv+=i; /* XXX horrible hack */
Eric Andersen25f27032001-04-26 23:22:31 +00001382 rcode = x->function(child);
Eric Andersen78a7c992001-05-15 16:30:25 +00001383 child->argv-=i; /* XXX restore hack so free() can work right */
Eric Andersen25f27032001-04-26 23:22:31 +00001384 restore_redirects(squirrel);
1385 return rcode;
1386 }
1387 }
1388 }
1389
1390 for (i = 0; i < pi->num_progs; i++) {
1391 child = & (pi->progs[i]);
1392
1393 /* pipes are inserted between pairs of commands */
1394 if ((i + 1) < pi->num_progs) {
1395 if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1396 nextout = pipefds[1];
1397 } else {
1398 nextout=1;
1399 pipefds[0] = -1;
1400 }
1401
1402 /* XXX test for failed fork()? */
1403 if (!(child->pid = fork())) {
Eric Andersen0fcd4472001-05-02 20:12:03 +00001404
Eric Andersenbafd94f2001-05-02 16:11:59 +00001405 signal(SIGTTOU, SIG_DFL);
1406
Eric Andersen25f27032001-04-26 23:22:31 +00001407 close_all();
1408
1409 if (nextin != 0) {
1410 dup2(nextin, 0);
1411 close(nextin);
1412 }
1413 if (nextout != 1) {
1414 dup2(nextout, 1);
1415 close(nextout);
1416 }
1417 if (pipefds[0]!=-1) {
1418 close(pipefds[0]); /* opposite end of our output pipe */
1419 }
1420
1421 /* Like bash, explicit redirects override pipes,
1422 * and the pipe fd is available for dup'ing. */
1423 setup_redirects(child,NULL);
Eric Andersen0fcd4472001-05-02 20:12:03 +00001424
Eric Andersenada18ff2001-05-21 16:18:22 +00001425 if (interactive && pi->followup!=PIPE_BG) {
Eric Andersenbfae2522001-05-17 00:14:27 +00001426 /* If we (the child) win the race, put ourselves in the process
1427 * group whose leader is the first process in this pipe. */
Eric Andersen0fcd4472001-05-02 20:12:03 +00001428 if (pi->pgrp < 0) {
Eric Andersenada18ff2001-05-21 16:18:22 +00001429 pi->pgrp = getpid();
Eric Andersen0fcd4472001-05-02 20:12:03 +00001430 }
Eric Andersen0fcd4472001-05-02 20:12:03 +00001431 if (setpgid(0, pi->pgrp) == 0) {
1432 signal(SIGTTOU, SIG_IGN);
1433 tcsetpgrp(ctty, pi->pgrp);
1434 signal(SIGTTOU, SIG_DFL);
1435 }
1436 }
Eric Andersen25f27032001-04-26 23:22:31 +00001437
1438 pseudo_exec(child);
1439 }
Eric Andersen0fcd4472001-05-02 20:12:03 +00001440 /* Put our child in the process group whose leader is the
1441 * first process in this pipe. */
1442 if (pi->pgrp < 0) {
1443 pi->pgrp = child->pid;
Eric Andersen25f27032001-04-26 23:22:31 +00001444 }
Eric Andersen0fcd4472001-05-02 20:12:03 +00001445 /* Don't check for errors. The child may be dead already,
1446 * in which case setpgid returns error code EACCES. */
1447 setpgid(child->pid, pi->pgrp);
1448
Eric Andersen25f27032001-04-26 23:22:31 +00001449 if (nextin != 0)
1450 close(nextin);
1451 if (nextout != 1)
1452 close(nextout);
1453
1454 /* If there isn't another process, nextin is garbage
1455 but it doesn't matter */
1456 nextin = pipefds[0];
1457 }
1458 return -1;
1459}
1460
1461static int run_list_real(struct pipe *pi)
1462{
1463 int rcode=0;
1464 int if_code=0, next_if_code=0; /* need double-buffer to handle elif */
Eric Andersen4ed5e372001-05-01 01:49:50 +00001465 reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
Eric Andersen25f27032001-04-26 23:22:31 +00001466 for (;pi;pi=pi->next) {
1467 rmode = pi->r_mode;
Eric Andersen4ed5e372001-05-01 01:49:50 +00001468 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);
1469 if (rmode == skip_more_in_this_rmode) continue;
1470 skip_more_in_this_rmode = RES_XXXX;
Eric Andersen25f27032001-04-26 23:22:31 +00001471 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1472 if (rmode == RES_THEN && if_code) continue;
1473 if (rmode == RES_ELSE && !if_code) continue;
1474 if (rmode == RES_ELIF && !if_code) continue;
Eric Andersen4ed5e372001-05-01 01:49:50 +00001475 if (pi->num_progs == 0) continue;
Eric Andersen25f27032001-04-26 23:22:31 +00001476 rcode = run_pipe_real(pi);
1477 if (rcode!=-1) {
1478 /* We only ran a builtin: rcode was set by the return value
1479 * of run_pipe_real(), and we don't need to wait for anything. */
1480 } else if (pi->followup==PIPE_BG) {
1481 /* XXX check bash's behavior with nontrivial pipes */
1482 /* XXX compute jobid */
1483 /* XXX what does bash do with attempts to background builtins? */
Eric Andersenbafd94f2001-05-02 16:11:59 +00001484 insert_bg_job(pi);
Eric Andersen25f27032001-04-26 23:22:31 +00001485 rcode = EXIT_SUCCESS;
1486 } else {
Eric Andersen0fcd4472001-05-02 20:12:03 +00001487
Eric Andersen25f27032001-04-26 23:22:31 +00001488 if (interactive) {
1489 /* move the new process group into the foreground */
1490 /* suppress messages when run from /linuxrc mag@sysgo.de */
Eric Andersenada18ff2001-05-21 16:18:22 +00001491 /* XXX probably this "0" should come from controlling_tty() */
Eric Andersen25f27032001-04-26 23:22:31 +00001492 if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY)
Eric Andersenada18ff2001-05-21 16:18:22 +00001493 perror_msg("tcsetpgrp-3");
Eric Andersen25f27032001-04-26 23:22:31 +00001494 rcode = pipe_wait(pi);
Matt Kraai1c8a59a2001-05-02 15:37:09 +00001495 if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY)
Eric Andersenada18ff2001-05-21 16:18:22 +00001496 perror_msg("tcsetpgrp-4");
Eric Andersen25f27032001-04-26 23:22:31 +00001497 } else {
1498 rcode = pipe_wait(pi);
1499 }
Matt Kraaibdd4ece2001-05-23 17:43:00 +00001500 debug_printf("pipe_wait returned %d\n",rcode);
Eric Andersen25f27032001-04-26 23:22:31 +00001501 }
1502 last_return_code=rcode;
1503 if ( rmode == RES_IF || rmode == RES_ELIF )
1504 next_if_code=rcode; /* can be overwritten a number of times */
1505 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1506 (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
Eric Andersen4ed5e372001-05-01 01:49:50 +00001507 skip_more_in_this_rmode=rmode;
Eric Andersen25f27032001-04-26 23:22:31 +00001508 }
Eric Andersenbafd94f2001-05-02 16:11:59 +00001509 checkjobs();
Eric Andersen25f27032001-04-26 23:22:31 +00001510 return rcode;
1511}
1512
1513/* broken, of course, but OK for testing */
1514static char *indenter(int i)
1515{
1516 static char blanks[]=" ";
1517 return &blanks[sizeof(blanks)-i-1];
1518}
1519
1520/* return code is the exit status of the pipe */
Eric Andersenbf7df042001-05-23 22:18:35 +00001521static int free_pipe(struct pipe *pi, int indent)
Eric Andersen25f27032001-04-26 23:22:31 +00001522{
1523 char **p;
1524 struct child_prog *child;
1525 struct redir_struct *r, *rnext;
1526 int a, i, ret_code=0;
1527 char *ind = indenter(indent);
1528 final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1529 for (i=0; i<pi->num_progs; i++) {
1530 child = &pi->progs[i];
1531 final_printf("%s command %d:\n",ind,i);
1532 if (child->argv) {
1533 for (a=0,p=child->argv; *p; a++,p++) {
1534 final_printf("%s argv[%d] = %s\n",ind,a,*p);
1535 }
1536 globfree(&child->glob_result);
1537 child->argv=NULL;
1538 } else if (child->group) {
1539 final_printf("%s begin group (subshell:%d)\n",ind, child->subshell);
Eric Andersenbf7df042001-05-23 22:18:35 +00001540 ret_code = free_pipe_list(child->group,indent+3);
Eric Andersen25f27032001-04-26 23:22:31 +00001541 final_printf("%s end group\n",ind);
1542 } else {
1543 final_printf("%s (nil)\n",ind);
1544 }
1545 for (r=child->redirects; r; r=rnext) {
1546 final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1547 if (r->dup == -1) {
1548 final_printf(" %s\n", *r->word.gl_pathv);
1549 globfree(&r->word);
1550 } else {
1551 final_printf("&%d\n", r->dup);
1552 }
1553 rnext=r->next;
1554 free(r);
1555 }
1556 child->redirects=NULL;
1557 }
1558 free(pi->progs); /* children are an array, they get freed all at once */
1559 pi->progs=NULL;
1560 return ret_code;
1561}
1562
Eric Andersenbf7df042001-05-23 22:18:35 +00001563static int free_pipe_list(struct pipe *head, int indent)
Eric Andersen25f27032001-04-26 23:22:31 +00001564{
1565 int rcode=0; /* if list has no members */
1566 struct pipe *pi, *next;
1567 char *ind = indenter(indent);
1568 for (pi=head; pi; pi=next) {
Eric Andersen25f27032001-04-26 23:22:31 +00001569 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
Eric Andersenbf7df042001-05-23 22:18:35 +00001570 rcode = free_pipe(pi, indent);
Eric Andersen25f27032001-04-26 23:22:31 +00001571 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1572 next=pi->next;
1573 pi->next=NULL;
1574 free(pi);
1575 }
1576 return rcode;
1577}
1578
1579/* Select which version we will use */
1580static int run_list(struct pipe *pi)
1581{
1582 int rcode=0;
1583 if (fake_mode==0) {
1584 rcode = run_list_real(pi);
1585 }
Eric Andersenbf7df042001-05-23 22:18:35 +00001586 /* free_pipe_list has the side effect of clearing memory
Eric Andersen25f27032001-04-26 23:22:31 +00001587 * In the long run that function can be merged with run_list_real,
1588 * but doing that now would hobble the debugging effort. */
Eric Andersenbf7df042001-05-23 22:18:35 +00001589 free_pipe_list(pi,0);
Eric Andersen25f27032001-04-26 23:22:31 +00001590 return rcode;
1591}
1592
1593/* The API for glob is arguably broken. This routine pushes a non-matching
1594 * string into the output structure, removing non-backslashed backslashes.
1595 * If someone can prove me wrong, by performing this function within the
1596 * original glob(3) api, feel free to rewrite this routine into oblivion.
1597 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
1598 * XXX broken if the last character is '\\', check that before calling.
1599 */
1600static int globhack(const char *src, int flags, glob_t *pglob)
1601{
1602 int cnt, pathc;
1603 const char *s;
1604 char *dest;
Eric Andersenbafd94f2001-05-02 16:11:59 +00001605 for (cnt=1, s=src; *s; s++) {
Eric Andersen25f27032001-04-26 23:22:31 +00001606 if (*s == '\\') s++;
1607 cnt++;
1608 }
1609 dest = malloc(cnt);
1610 if (!dest) return GLOB_NOSPACE;
1611 if (!(flags & GLOB_APPEND)) {
1612 pglob->gl_pathv=NULL;
1613 pglob->gl_pathc=0;
1614 pglob->gl_offs=0;
1615 pglob->gl_offs=0;
1616 }
1617 pathc = ++pglob->gl_pathc;
1618 pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
1619 if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
1620 pglob->gl_pathv[pathc-1]=dest;
1621 pglob->gl_pathv[pathc]=NULL;
Eric Andersenbafd94f2001-05-02 16:11:59 +00001622 for (s=src; *s; s++, dest++) {
Eric Andersen25f27032001-04-26 23:22:31 +00001623 if (*s == '\\') s++;
1624 *dest = *s;
1625 }
1626 *dest='\0';
1627 return 0;
1628}
1629
1630/* XXX broken if the last character is '\\', check that before calling */
1631static int glob_needed(const char *s)
1632{
1633 for (; *s; s++) {
1634 if (*s == '\\') s++;
1635 if (strchr("*[?",*s)) return 1;
1636 }
1637 return 0;
1638}
1639
1640#if 0
1641static void globprint(glob_t *pglob)
1642{
1643 int i;
1644 debug_printf("glob_t at %p:\n", pglob);
1645 debug_printf(" gl_pathc=%d gl_pathv=%p gl_offs=%d gl_flags=%d\n",
1646 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
1647 for (i=0; i<pglob->gl_pathc; i++)
1648 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
1649 pglob->gl_pathv[i], pglob->gl_pathv[i]);
1650}
1651#endif
1652
1653static int xglob(o_string *dest, int flags, glob_t *pglob)
1654{
1655 int gr;
1656
1657 /* short-circuit for null word */
1658 /* we can code this better when the debug_printf's are gone */
1659 if (dest->length == 0) {
1660 if (dest->nonnull) {
1661 /* bash man page calls this an "explicit" null */
1662 gr = globhack(dest->data, flags, pglob);
1663 debug_printf("globhack returned %d\n",gr);
1664 } else {
1665 return 0;
1666 }
1667 } else if (glob_needed(dest->data)) {
1668 gr = glob(dest->data, flags, NULL, pglob);
1669 debug_printf("glob returned %d\n",gr);
1670 if (gr == GLOB_NOMATCH) {
1671 /* quote removal, or more accurately, backslash removal */
1672 gr = globhack(dest->data, flags, pglob);
1673 debug_printf("globhack returned %d\n",gr);
1674 }
1675 } else {
1676 gr = globhack(dest->data, flags, pglob);
1677 debug_printf("globhack returned %d\n",gr);
1678 }
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001679 if (gr == GLOB_NOSPACE)
1680 error_msg_and_die("out of memory during glob");
Eric Andersen25f27032001-04-26 23:22:31 +00001681 if (gr != 0) { /* GLOB_ABORTED ? */
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001682 error_msg("glob(3) error %d",gr);
Eric Andersen25f27032001-04-26 23:22:31 +00001683 }
1684 /* globprint(glob_target); */
1685 return gr;
1686}
1687
Eric Andersenf72f5622001-05-15 23:21:41 +00001688/* This is used to get/check local shell variables */
1689static char *get_local_var(const char *s)
1690{
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001691 struct variables *cur;
Eric Andersenf72f5622001-05-15 23:21:41 +00001692
1693 if (!s)
1694 return NULL;
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001695 for (cur = top_vars; cur; cur=cur->next)
1696 if(strcmp(cur->name, s)==0)
1697 return cur->value;
Eric Andersenf72f5622001-05-15 23:21:41 +00001698 return NULL;
1699}
1700
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001701/* This is used to set local shell variables
1702 flg_export==0 if only local (not exporting) variable
1703 flg_export==1 if "new" exporting environ
1704 flg_export>1 if current startup environ (not call putenv()) */
1705static int set_local_var(const char *s, int flg_export)
Eric Andersen78a7c992001-05-15 16:30:25 +00001706{
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001707 char *name, *value;
Eric Andersen20a69a72001-05-15 17:24:44 +00001708 int result=0;
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001709 struct variables *cur;
Eric Andersen20a69a72001-05-15 17:24:44 +00001710
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001711 name=strdup(s);
Eric Andersen20a69a72001-05-15 17:24:44 +00001712
1713 /* Assume when we enter this function that we are already in
1714 * NAME=VALUE format. So the first order of business is to
1715 * split 's' on the '=' into 'name' and 'value' */
1716 value = strchr(name, '=');
Eric Andersen99785762001-05-22 21:37:48 +00001717 if (value==0 && ++value==0) {
1718 free(name);
1719 return -1;
1720 }
1721 *value++ = 0;
Eric Andersen20a69a72001-05-15 17:24:44 +00001722
Eric Andersen99785762001-05-22 21:37:48 +00001723 for(cur = top_vars; cur; cur = cur->next) {
1724 if(strcmp(cur->name, name)==0)
1725 break;
1726 }
Eric Andersen20a69a72001-05-15 17:24:44 +00001727
Eric Andersen99785762001-05-22 21:37:48 +00001728 if(cur) {
1729 if(strcmp(cur->value, value)==0) {
1730 if(flg_export>0 && cur->flg_export==0)
1731 cur->flg_export=flg_export;
1732 else
1733 result++;
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001734 } else {
Eric Andersen99785762001-05-22 21:37:48 +00001735 if(cur->flg_read_only) {
1736 error_msg("%s: readonly variable", name);
Eric Andersen20a69a72001-05-15 17:24:44 +00001737 result = -1;
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001738 } else {
Eric Andersen99785762001-05-22 21:37:48 +00001739 if(flg_export>0 || cur->flg_export>1)
1740 cur->flg_export=1;
1741 free(cur->value);
1742
1743 cur->value = strdup(value);
1744 }
1745 }
1746 } else {
1747 cur = malloc(sizeof(struct variables));
1748 if(!cur) {
1749 result = -1;
1750 } else {
1751 cur->name = strdup(name);
1752 if(cur->name == 0) {
1753 free(cur);
1754 result = -1;
1755 } else {
1756 struct variables *bottom = top_vars;
1757 cur->value = strdup(value);
1758 cur->next = 0;
1759 cur->flg_export = flg_export;
1760 cur->flg_read_only = 0;
1761 while(bottom->next) bottom=bottom->next;
1762 bottom->next = cur;
Eric Andersen20a69a72001-05-15 17:24:44 +00001763 }
Eric Andersen20a69a72001-05-15 17:24:44 +00001764 }
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001765 }
Eric Andersen20a69a72001-05-15 17:24:44 +00001766
Eric Andersen94ac2442001-05-22 19:05:18 +00001767 if(result==0 && cur->flg_export==1) {
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001768 *(value-1) = '=';
1769 result = putenv(name);
1770 } else {
Eric Andersen94ac2442001-05-22 19:05:18 +00001771 free(name);
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001772 if(result>0) /* equivalent to previous set */
1773 result = 0;
1774 }
Eric Andersen20a69a72001-05-15 17:24:44 +00001775 return result;
1776}
1777
Eric Andersenf72f5622001-05-15 23:21:41 +00001778static void unset_local_var(const char *name)
Eric Andersen20a69a72001-05-15 17:24:44 +00001779{
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001780 struct variables *cur;
Eric Andersen20a69a72001-05-15 17:24:44 +00001781
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001782 if (name) {
Eric Andersen94ac2442001-05-22 19:05:18 +00001783 for (cur = top_vars; cur; cur=cur->next) {
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001784 if(strcmp(cur->name, name)==0)
1785 break;
Eric Andersen94ac2442001-05-22 19:05:18 +00001786 }
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001787 if(cur!=0) {
1788 struct variables *next = top_vars;
Eric Andersen94ac2442001-05-22 19:05:18 +00001789 if(cur->flg_read_only) {
1790 error_msg("%s: readonly variable", name);
1791 return;
1792 } else {
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001793 if(cur->flg_export)
1794 unsetenv(cur->name);
1795 free(cur->name);
1796 free(cur->value);
1797 while (next->next != cur)
1798 next = next->next;
1799 next->next = cur->next;
1800 }
1801 free(cur);
Eric Andersenf72f5622001-05-15 23:21:41 +00001802 }
Eric Andersen20a69a72001-05-15 17:24:44 +00001803 }
Eric Andersen78a7c992001-05-15 16:30:25 +00001804}
1805
1806static int is_assignment(const char *s)
1807{
1808 if (s==NULL || !isalpha(*s)) return 0;
1809 ++s;
1810 while(isalnum(*s) || *s=='_') ++s;
1811 return *s=='=';
1812}
1813
Eric Andersen25f27032001-04-26 23:22:31 +00001814/* the src parameter allows us to peek forward to a possible &n syntax
1815 * for file descriptor duplication, e.g., "2>&1".
1816 * Return code is 0 normally, 1 if a syntax error is detected in src.
1817 * Resource errors (in xmalloc) cause the process to exit */
1818static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
1819 struct in_str *input)
1820{
1821 struct child_prog *child=ctx->child;
1822 struct redir_struct *redir = child->redirects;
1823 struct redir_struct *last_redir=NULL;
1824
1825 /* Create a new redir_struct and drop it onto the end of the linked list */
1826 while(redir) {
1827 last_redir=redir;
1828 redir=redir->next;
1829 }
1830 redir = xmalloc(sizeof(struct redir_struct));
1831 redir->next=NULL;
1832 if (last_redir) {
1833 last_redir->next=redir;
1834 } else {
1835 child->redirects=redir;
1836 }
1837
1838 redir->type=style;
1839 redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
1840
1841 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
1842
1843 /* Check for a '2>&1' type redirect */
1844 redir->dup = redirect_dup_num(input);
1845 if (redir->dup == -2) return 1; /* syntax error */
1846 if (redir->dup != -1) {
1847 /* Erik had a check here that the file descriptor in question
Eric Andersen83a2ae22001-05-07 17:59:25 +00001848 * is legit; I postpone that to "run time"
1849 * A "-" representation of "close me" shows up as a -3 here */
Eric Andersen25f27032001-04-26 23:22:31 +00001850 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
1851 } else {
1852 /* We do _not_ try to open the file that src points to,
1853 * since we need to return and let src be expanded first.
1854 * Set ctx->pending_redirect, so we know what to do at the
1855 * end of the next parsed word.
1856 */
1857 ctx->pending_redirect = redir;
1858 }
1859 return 0;
1860}
1861
1862struct pipe *new_pipe(void) {
1863 struct pipe *pi;
1864 pi = xmalloc(sizeof(struct pipe));
1865 pi->num_progs = 0;
1866 pi->progs = NULL;
1867 pi->next = NULL;
1868 pi->followup = 0; /* invalid */
1869 return pi;
1870}
1871
1872static void initialize_context(struct p_context *ctx)
1873{
1874 ctx->pipe=NULL;
1875 ctx->pending_redirect=NULL;
1876 ctx->child=NULL;
1877 ctx->list_head=new_pipe();
1878 ctx->pipe=ctx->list_head;
1879 ctx->w=RES_NONE;
1880 ctx->stack=NULL;
1881 done_command(ctx); /* creates the memory for working child */
1882}
1883
1884/* normal return is 0
1885 * if a reserved word is found, and processed, return 1
1886 * should handle if, then, elif, else, fi, for, while, until, do, done.
1887 * case, function, and select are obnoxious, save those for later.
1888 */
1889int reserved_word(o_string *dest, struct p_context *ctx)
1890{
1891 struct reserved_combo {
1892 char *literal;
1893 int code;
1894 long flag;
1895 };
1896 /* Mostly a list of accepted follow-up reserved words.
1897 * FLAG_END means we are done with the sequence, and are ready
1898 * to turn the compound list into a command.
1899 * FLAG_START means the word must start a new compound list.
1900 */
1901 static struct reserved_combo reserved_list[] = {
1902 { "if", RES_IF, FLAG_THEN | FLAG_START },
1903 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
1904 { "elif", RES_ELIF, FLAG_THEN },
1905 { "else", RES_ELSE, FLAG_FI },
1906 { "fi", RES_FI, FLAG_END },
1907 { "for", RES_FOR, FLAG_DO | FLAG_START },
1908 { "while", RES_WHILE, FLAG_DO | FLAG_START },
1909 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
1910 { "do", RES_DO, FLAG_DONE },
1911 { "done", RES_DONE, FLAG_END }
1912 };
1913 struct reserved_combo *r;
1914 for (r=reserved_list;
1915#define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
1916 r<reserved_list+NRES; r++) {
1917 if (strcmp(dest->data, r->literal) == 0) {
1918 debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
1919 if (r->flag & FLAG_START) {
1920 struct p_context *new = xmalloc(sizeof(struct p_context));
1921 debug_printf("push stack\n");
1922 *new = *ctx; /* physical copy */
1923 initialize_context(ctx);
1924 ctx->stack=new;
1925 } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
Eric Andersenaf44a0e2001-04-27 07:26:12 +00001926 syntax();
1927 ctx->w = RES_SNTX;
1928 b_reset (dest);
1929 return 1;
Eric Andersen25f27032001-04-26 23:22:31 +00001930 }
1931 ctx->w=r->code;
1932 ctx->old_flag = r->flag;
1933 if (ctx->old_flag & FLAG_END) {
1934 struct p_context *old;
1935 debug_printf("pop stack\n");
1936 old = ctx->stack;
1937 old->child->group = ctx->list_head;
1938 *ctx = *old; /* physical copy */
1939 free(old);
Eric Andersen25f27032001-04-26 23:22:31 +00001940 }
1941 b_reset (dest);
1942 return 1;
1943 }
1944 }
1945 return 0;
1946}
1947
1948/* normal return is 0.
1949 * Syntax or xglob errors return 1. */
1950static int done_word(o_string *dest, struct p_context *ctx)
1951{
1952 struct child_prog *child=ctx->child;
1953 glob_t *glob_target;
1954 int gr, flags = 0;
1955
1956 debug_printf("done_word: %s %p\n", dest->data, child);
1957 if (dest->length == 0 && !dest->nonnull) {
1958 debug_printf(" true null, ignored\n");
1959 return 0;
1960 }
1961 if (ctx->pending_redirect) {
1962 glob_target = &ctx->pending_redirect->word;
1963 } else {
1964 if (child->group) {
1965 syntax();
1966 return 1; /* syntax error, groups and arglists don't mix */
1967 }
1968 if (!child->argv) {
1969 debug_printf("checking %s for reserved-ness\n",dest->data);
Eric Andersenaf44a0e2001-04-27 07:26:12 +00001970 if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
Eric Andersen25f27032001-04-26 23:22:31 +00001971 }
1972 glob_target = &child->glob_result;
1973 if (child->argv) flags |= GLOB_APPEND;
1974 }
1975 gr = xglob(dest, flags, glob_target);
1976 if (gr != 0) return 1;
1977
1978 b_reset(dest);
1979 if (ctx->pending_redirect) {
1980 ctx->pending_redirect=NULL;
1981 if (glob_target->gl_pathc != 1) {
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00001982 error_msg("ambiguous redirect");
Eric Andersen25f27032001-04-26 23:22:31 +00001983 return 1;
1984 }
1985 } else {
1986 child->argv = glob_target->gl_pathv;
1987 }
1988 return 0;
1989}
1990
1991/* The only possible error here is out of memory, in which case
1992 * xmalloc exits. */
1993static int done_command(struct p_context *ctx)
1994{
1995 /* The child is really already in the pipe structure, so
1996 * advance the pipe counter and make a new, null child.
1997 * Only real trickiness here is that the uncommitted
1998 * child structure, to which ctx->child points, is not
1999 * counted in pi->num_progs. */
2000 struct pipe *pi=ctx->pipe;
2001 struct child_prog *prog=ctx->child;
2002
2003 if (prog && prog->group == NULL
2004 && prog->argv == NULL
2005 && prog->redirects == NULL) {
2006 debug_printf("done_command: skipping null command\n");
2007 return 0;
2008 } else if (prog) {
2009 pi->num_progs++;
2010 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2011 } else {
2012 debug_printf("done_command: initializing\n");
2013 }
2014 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2015
2016 prog = pi->progs + pi->num_progs;
2017 prog->redirects = NULL;
2018 prog->argv = NULL;
2019 prog->is_stopped = 0;
2020 prog->group = NULL;
2021 prog->glob_result.gl_pathv = NULL;
2022 prog->family = pi;
2023
2024 ctx->child=prog;
2025 /* but ctx->pipe and ctx->list_head remain unchanged */
2026 return 0;
2027}
2028
2029static int done_pipe(struct p_context *ctx, pipe_style type)
2030{
2031 struct pipe *new_p;
2032 done_command(ctx); /* implicit closure of previous command */
2033 debug_printf("done_pipe, type %d\n", type);
2034 ctx->pipe->followup = type;
2035 ctx->pipe->r_mode = ctx->w;
2036 new_p=new_pipe();
2037 ctx->pipe->next = new_p;
2038 ctx->pipe = new_p;
2039 ctx->child = NULL;
2040 done_command(ctx); /* set up new pipe to accept commands */
2041 return 0;
2042}
2043
2044/* peek ahead in the in_str to find out if we have a "&n" construct,
2045 * as in "2>&1", that represents duplicating a file descriptor.
2046 * returns either -2 (syntax error), -1 (no &), or the number found.
2047 */
2048static int redirect_dup_num(struct in_str *input)
2049{
2050 int ch, d=0, ok=0;
2051 ch = b_peek(input);
2052 if (ch != '&') return -1;
2053
2054 b_getch(input); /* get the & */
Eric Andersen83a2ae22001-05-07 17:59:25 +00002055 ch=b_peek(input);
2056 if (ch == '-') {
2057 b_getch(input);
2058 return -3; /* "-" represents "close me" */
2059 }
2060 while (isdigit(ch)) {
Eric Andersen25f27032001-04-26 23:22:31 +00002061 d = d*10+(ch-'0');
2062 ok=1;
2063 b_getch(input);
Eric Andersen83a2ae22001-05-07 17:59:25 +00002064 ch = b_peek(input);
Eric Andersen25f27032001-04-26 23:22:31 +00002065 }
2066 if (ok) return d;
2067
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00002068 error_msg("ambiguous redirect");
Eric Andersen25f27032001-04-26 23:22:31 +00002069 return -2;
2070}
2071
2072/* If a redirect is immediately preceded by a number, that number is
2073 * supposed to tell which file descriptor to redirect. This routine
2074 * looks for such preceding numbers. In an ideal world this routine
2075 * needs to handle all the following classes of redirects...
2076 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
2077 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
2078 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
2079 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
2080 * A -1 output from this program means no valid number was found, so the
2081 * caller should use the appropriate default for this redirection.
2082 */
2083static int redirect_opt_num(o_string *o)
2084{
2085 int num;
2086
2087 if (o->length==0) return -1;
2088 for(num=0; num<o->length; num++) {
2089 if (!isdigit(*(o->data+num))) {
2090 return -1;
2091 }
2092 }
2093 /* reuse num (and save an int) */
2094 num=atoi(o->data);
2095 b_reset(o);
2096 return num;
2097}
2098
2099FILE *generate_stream_from_list(struct pipe *head)
2100{
2101 FILE *pf;
2102#if 1
2103 int pid, channel[2];
2104 if (pipe(channel)<0) perror_msg_and_die("pipe");
2105 pid=fork();
2106 if (pid<0) {
2107 perror_msg_and_die("fork");
2108 } else if (pid==0) {
2109 close(channel[0]);
2110 if (channel[1] != 1) {
2111 dup2(channel[1],1);
2112 close(channel[1]);
2113 }
2114#if 0
2115#define SURROGATE "surrogate response"
2116 write(1,SURROGATE,sizeof(SURROGATE));
Eric Andersen94ac2442001-05-22 19:05:18 +00002117 _exit(run_list(head));
Eric Andersen25f27032001-04-26 23:22:31 +00002118#else
Eric Andersen94ac2442001-05-22 19:05:18 +00002119 _exit(run_list_real(head)); /* leaks memory */
Eric Andersen25f27032001-04-26 23:22:31 +00002120#endif
2121 }
2122 debug_printf("forked child %d\n",pid);
2123 close(channel[1]);
2124 pf = fdopen(channel[0],"r");
2125 debug_printf("pipe on FILE *%p\n",pf);
2126#else
Eric Andersenbf7df042001-05-23 22:18:35 +00002127 free_pipe_list(head,0);
Eric Andersen25f27032001-04-26 23:22:31 +00002128 pf=popen("echo surrogate response","r");
2129 debug_printf("started fake pipe on FILE *%p\n",pf);
2130#endif
2131 return pf;
2132}
2133
2134/* this version hacked for testing purposes */
2135/* return code is exit status of the process that is run. */
2136static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2137{
2138 int retcode;
2139 o_string result=NULL_O_STRING;
2140 struct p_context inner;
2141 FILE *p;
2142 struct in_str pipe_str;
2143 initialize_context(&inner);
2144
2145 /* recursion to generate command */
2146 retcode = parse_stream(&result, &inner, input, subst_end);
2147 if (retcode != 0) return retcode; /* syntax error or EOF */
2148 done_word(&result, &inner);
2149 done_pipe(&inner, PIPE_SEQ);
2150 b_free(&result);
2151
2152 p=generate_stream_from_list(inner.list_head);
2153 if (p==NULL) return 1;
2154 mark_open(fileno(p));
2155 setup_file_in_str(&pipe_str, p);
2156
2157 /* now send results of command back into original context */
2158 retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2159 /* XXX In case of a syntax error, should we try to kill the child?
2160 * That would be tough to do right, so just read until EOF. */
2161 if (retcode == 1) {
2162 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2163 }
2164
2165 debug_printf("done reading from pipe, pclose()ing\n");
2166 /* This is the step that wait()s for the child. Should be pretty
2167 * safe, since we just read an EOF from its stdout. We could try
2168 * to better, by using wait(), and keeping track of background jobs
2169 * at the same time. That would be a lot of work, and contrary
2170 * to the KISS philosophy of this program. */
2171 mark_closed(fileno(p));
2172 retcode=pclose(p);
Eric Andersena15dc152001-05-23 23:46:09 +00002173 free_pipe_list(inner.list_head,0);
Eric Andersen25f27032001-04-26 23:22:31 +00002174 debug_printf("pclosed, retcode=%d\n",retcode);
2175 /* XXX this process fails to trim a single trailing newline */
2176 return retcode;
2177}
2178
2179static int parse_group(o_string *dest, struct p_context *ctx,
2180 struct in_str *input, int ch)
2181{
2182 int rcode, endch=0;
2183 struct p_context sub;
2184 struct child_prog *child = ctx->child;
2185 if (child->argv) {
2186 syntax();
2187 return 1; /* syntax error, groups and arglists don't mix */
2188 }
2189 initialize_context(&sub);
2190 switch(ch) {
2191 case '(': endch=')'; child->subshell=1; break;
2192 case '{': endch='}'; break;
2193 default: syntax(); /* really logic error */
2194 }
2195 rcode=parse_stream(dest,&sub,input,endch);
2196 done_word(dest,&sub); /* finish off the final word in the subcontext */
2197 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
2198 child->group = sub.list_head;
2199 return rcode;
2200 /* child remains "open", available for possible redirects */
2201}
2202
2203/* basically useful version until someone wants to get fancier,
2204 * see the bash man page under "Parameter Expansion" */
2205static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src)
2206{
2207 const char *p=NULL;
Eric Andersen20a69a72001-05-15 17:24:44 +00002208 if (src->data) {
Eric Andersenf72f5622001-05-15 23:21:41 +00002209 p = getenv(src->data);
2210 if (!p)
2211 p = get_local_var(src->data);
Eric Andersen20a69a72001-05-15 17:24:44 +00002212 }
Eric Andersen25f27032001-04-26 23:22:31 +00002213 if (p) parse_string(dest, ctx, p); /* recursion */
2214 b_free(src);
2215}
2216
2217/* return code: 0 for OK, 1 for syntax error */
2218static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2219{
2220 int i, advance=0;
2221 o_string alt=NULL_O_STRING;
2222 char sep[]=" ";
2223 int ch = input->peek(input); /* first character after the $ */
2224 debug_printf("handle_dollar: ch=%c\n",ch);
2225 if (isalpha(ch)) {
2226 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2227 b_getch(input);
2228 b_addchr(&alt,ch);
2229 }
2230 lookup_param(dest, ctx, &alt);
2231 } else if (isdigit(ch)) {
2232 i = ch-'0'; /* XXX is $0 special? */
2233 if (i<global_argc) {
2234 parse_string(dest, ctx, global_argv[i]); /* recursion */
2235 }
2236 advance = 1;
2237 } else switch (ch) {
2238 case '$':
2239 b_adduint(dest,getpid());
2240 advance = 1;
2241 break;
2242 case '!':
2243 if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2244 advance = 1;
2245 break;
2246 case '?':
2247 b_adduint(dest,last_return_code);
2248 advance = 1;
2249 break;
2250 case '#':
2251 b_adduint(dest,global_argc ? global_argc-1 : 0);
2252 advance = 1;
2253 break;
2254 case '{':
2255 b_getch(input);
2256 /* XXX maybe someone will try to escape the '}' */
2257 while(ch=b_getch(input),ch!=EOF && ch!='}') {
2258 b_addchr(&alt,ch);
2259 }
2260 if (ch != '}') {
2261 syntax();
2262 return 1;
2263 }
2264 lookup_param(dest, ctx, &alt);
2265 break;
2266 case '(':
Matt Kraai9f8caf12001-05-02 16:26:12 +00002267 b_getch(input);
Eric Andersen25f27032001-04-26 23:22:31 +00002268 process_command_subs(dest, ctx, input, ')');
2269 break;
2270 case '*':
2271 sep[0]=ifs[0];
2272 for (i=1; i<global_argc; i++) {
2273 parse_string(dest, ctx, global_argv[i]);
2274 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2275 }
2276 break;
2277 case '@':
2278 case '-':
2279 case '_':
2280 /* still unhandled, but should be eventually */
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00002281 error_msg("unhandled syntax: $%c",ch);
Eric Andersen25f27032001-04-26 23:22:31 +00002282 return 1;
2283 break;
2284 default:
2285 b_addqchr(dest,'$',dest->quote);
2286 }
2287 /* Eat the character if the flag was set. If the compiler
2288 * is smart enough, we could substitute "b_getch(input);"
2289 * for all the "advance = 1;" above, and also end up with
2290 * a nice size-optimized program. Hah! That'll be the day.
2291 */
2292 if (advance) b_getch(input);
2293 return 0;
2294}
2295
2296int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2297{
2298 struct in_str foo;
2299 setup_string_in_str(&foo, src);
2300 return parse_stream(dest, ctx, &foo, '\0');
2301}
2302
2303/* return code is 0 for normal exit, 1 for syntax error */
2304int parse_stream(o_string *dest, struct p_context *ctx,
2305 struct in_str *input, int end_trigger)
2306{
2307 unsigned int ch, m;
2308 int redir_fd;
2309 redir_type redir_style;
2310 int next;
2311
2312 /* Only double-quote state is handled in the state variable dest->quote.
2313 * A single-quote triggers a bypass of the main loop until its mate is
2314 * found. When recursing, quote state is passed in via dest->quote. */
2315
2316 debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2317 while ((ch=b_getch(input))!=EOF) {
2318 m = map[ch];
2319 next = (ch == '\n') ? 0 : b_peek(input);
2320 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2321 ch,ch,m,dest->quote);
2322 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2323 b_addqchr(dest, ch, dest->quote);
Eric Andersenaac75e52001-04-30 18:18:45 +00002324 } else {
2325 if (m==2) { /* unquoted IFS */
2326 done_word(dest, ctx);
Matt Kraai20a30692001-05-02 17:52:49 +00002327 /* If we aren't performing a substitution, treat a newline as a
2328 * command separator. */
2329 if (end_trigger != '\0' && ch=='\n')
2330 done_pipe(ctx,PIPE_SEQ);
Eric Andersenaac75e52001-04-30 18:18:45 +00002331 }
Eric Andersenaf44a0e2001-04-27 07:26:12 +00002332 if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
Matt Kraaibdd4ece2001-05-23 17:43:00 +00002333 debug_printf("leaving parse_stream (triggered)\n");
Eric Andersenaf44a0e2001-04-27 07:26:12 +00002334 return 0;
2335 }
Eric Andersen25f27032001-04-26 23:22:31 +00002336#if 0
2337 if (ch=='\n') {
2338 /* Yahoo! Time to run with it! */
2339 done_pipe(ctx,PIPE_SEQ);
2340 run_list(ctx->list_head);
2341 initialize_context(ctx);
2342 }
2343#endif
Eric Andersenaac75e52001-04-30 18:18:45 +00002344 if (m!=2) switch (ch) {
Eric Andersen25f27032001-04-26 23:22:31 +00002345 case '#':
2346 if (dest->length == 0 && !dest->quote) {
2347 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2348 } else {
2349 b_addqchr(dest, ch, dest->quote);
2350 }
2351 break;
2352 case '\\':
2353 if (next == EOF) {
2354 syntax();
2355 return 1;
2356 }
2357 b_addqchr(dest, '\\', dest->quote);
2358 b_addqchr(dest, b_getch(input), dest->quote);
2359 break;
2360 case '$':
2361 if (handle_dollar(dest, ctx, input)!=0) return 1;
2362 break;
2363 case '\'':
2364 dest->nonnull = 1;
2365 while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2366 b_addchr(dest,ch);
2367 }
2368 if (ch==EOF) {
2369 syntax();
2370 return 1;
2371 }
2372 break;
2373 case '"':
2374 dest->nonnull = 1;
2375 dest->quote = !dest->quote;
2376 break;
2377 case '`':
2378 process_command_subs(dest, ctx, input, '`');
2379 break;
2380 case '>':
2381 redir_fd = redirect_opt_num(dest);
2382 done_word(dest, ctx);
2383 redir_style=REDIRECT_OVERWRITE;
2384 if (next == '>') {
2385 redir_style=REDIRECT_APPEND;
2386 b_getch(input);
2387 } else if (next == '(') {
2388 syntax(); /* until we support >(list) Process Substitution */
2389 return 1;
2390 }
2391 setup_redirect(ctx, redir_fd, redir_style, input);
2392 break;
2393 case '<':
2394 redir_fd = redirect_opt_num(dest);
2395 done_word(dest, ctx);
2396 redir_style=REDIRECT_INPUT;
2397 if (next == '<') {
2398 redir_style=REDIRECT_HEREIS;
2399 b_getch(input);
2400 } else if (next == '>') {
2401 redir_style=REDIRECT_IO;
2402 b_getch(input);
2403 } else if (next == '(') {
2404 syntax(); /* until we support <(list) Process Substitution */
2405 return 1;
2406 }
2407 setup_redirect(ctx, redir_fd, redir_style, input);
2408 break;
2409 case ';':
2410 done_word(dest, ctx);
2411 done_pipe(ctx,PIPE_SEQ);
2412 break;
2413 case '&':
2414 done_word(dest, ctx);
2415 if (next=='&') {
2416 b_getch(input);
2417 done_pipe(ctx,PIPE_AND);
2418 } else {
2419 done_pipe(ctx,PIPE_BG);
2420 }
2421 break;
2422 case '|':
2423 done_word(dest, ctx);
2424 if (next=='|') {
2425 b_getch(input);
2426 done_pipe(ctx,PIPE_OR);
2427 } else {
2428 /* we could pick up a file descriptor choice here
2429 * with redirect_opt_num(), but bash doesn't do it.
2430 * "echo foo 2| cat" yields "foo 2". */
2431 done_command(ctx);
2432 }
2433 break;
2434 case '(':
2435 case '{':
2436 if (parse_group(dest, ctx, input, ch)!=0) return 1;
2437 break;
2438 case ')':
2439 case '}':
2440 syntax(); /* Proper use of this character caught by end_trigger */
2441 return 1;
2442 break;
2443 default:
2444 syntax(); /* this is really an internal logic error */
2445 return 1;
Eric Andersenaac75e52001-04-30 18:18:45 +00002446 }
Eric Andersen25f27032001-04-26 23:22:31 +00002447 }
2448 }
2449 /* complain if quote? No, maybe we just finished a command substitution
2450 * that was quoted. Example:
2451 * $ echo "`cat foo` plus more"
2452 * and we just got the EOF generated by the subshell that ran "cat foo"
2453 * The only real complaint is if we got an EOF when end_trigger != '\0',
2454 * that is, we were really supposed to get end_trigger, and never got
2455 * one before the EOF. Can't use the standard "syntax error" return code,
2456 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
Matt Kraaibdd4ece2001-05-23 17:43:00 +00002457 debug_printf("leaving parse_stream (EOF)\n");
Eric Andersen25f27032001-04-26 23:22:31 +00002458 if (end_trigger != '\0') return -1;
2459 return 0;
2460}
2461
2462void mapset(const unsigned char *set, int code)
2463{
2464 const unsigned char *s;
2465 for (s=set; *s; s++) map[*s] = code;
2466}
2467
2468void update_ifs_map(void)
2469{
2470 /* char *ifs and char map[256] are both globals. */
2471 ifs = getenv("IFS");
2472 if (ifs == NULL) ifs=" \t\n";
2473 /* Precompute a list of 'flow through' behavior so it can be treated
2474 * quickly up front. Computation is necessary because of IFS.
2475 * Special case handling of IFS == " \t\n" is not implemented.
2476 * The map[] array only really needs two bits each, and on most machines
2477 * that would be faster because of the reduced L1 cache footprint.
2478 */
Eric Andersenaeb44c42001-05-22 20:29:00 +00002479 memset(map,0,sizeof(map)); /* most characters flow through always */
2480 mapset("\\$'\"`", 3); /* never flow through */
2481 mapset("<>;&|(){}#", 1); /* flow through if quoted */
2482 mapset(ifs, 2); /* also flow through if quoted */
Eric Andersen25f27032001-04-26 23:22:31 +00002483}
2484
2485/* most recursion does not come through here, the exeception is
2486 * from builtin_source() */
2487int parse_stream_outer(struct in_str *inp)
2488{
2489
2490 struct p_context ctx;
2491 o_string temp=NULL_O_STRING;
2492 int rcode;
2493 do {
2494 initialize_context(&ctx);
2495 update_ifs_map();
2496 inp->promptmode=1;
2497 rcode = parse_stream(&temp, &ctx, inp, '\n');
2498 done_word(&temp, &ctx);
2499 done_pipe(&ctx,PIPE_SEQ);
2500 run_list(ctx.list_head);
Eric Andersena813afc2001-05-24 16:19:36 +00002501 b_free(&temp);
Eric Andersen25f27032001-04-26 23:22:31 +00002502 } while (rcode != -1); /* loop on syntax errors, return on EOF */
2503 return 0;
2504}
2505
2506static int parse_string_outer(const char *s)
2507{
2508 struct in_str input;
2509 setup_string_in_str(&input, s);
2510 return parse_stream_outer(&input);
2511}
2512
2513static int parse_file_outer(FILE *f)
2514{
2515 int rcode;
2516 struct in_str input;
2517 setup_file_in_str(&input, f);
2518 rcode = parse_stream_outer(&input);
2519 return rcode;
2520}
2521
Eric Andersenada18ff2001-05-21 16:18:22 +00002522
2523/* I think Erik wrote this. It looks imperfect at best */
2524void grab_tty_control(void)
2525{
2526 pid_t initialpgrp;
2527 do {
2528 initialpgrp = tcgetpgrp(fileno(stderr));
2529 if (initialpgrp < 0) {
2530 error_msg("sh: can't access tty; job control disabled\n");
2531 }
2532 if (initialpgrp == -1)
2533 initialpgrp = getpgrp();
2534 else if (initialpgrp != getpgrp()) {
2535 killpg(initialpgrp, SIGTTIN);
2536 continue;
2537 }
2538 } while (0);
2539}
2540
Eric Andersen25f27032001-04-26 23:22:31 +00002541int shell_main(int argc, char **argv)
2542{
2543 int opt;
2544 FILE *input;
Eric Andersenbafd94f2001-05-02 16:11:59 +00002545 struct jobset joblist_end = { NULL, NULL };
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00002546 char **e = environ;
Eric Andersenbc604a22001-05-16 05:24:03 +00002547
Eric Andersen25f27032001-04-26 23:22:31 +00002548 /* XXX what should these be while sourcing /etc/profile? */
2549 global_argc = argc;
2550 global_argv = argv;
Eric Andersen94ac2442001-05-22 19:05:18 +00002551
2552 /* (re?) initialize globals. Sometimes shell_main() ends up calling
2553 * shell_main(), therefore we cannot rely on the BSS to zero out this
2554 * stuff. Reset these to 0 every time. */
2555 ifs = NULL;
Eric Andersenaeb44c42001-05-22 20:29:00 +00002556 /* map[] is taken care of with call to update_ifs_map() */
Eric Andersen94ac2442001-05-22 19:05:18 +00002557 fake_mode = 0;
2558 interactive = 0;
2559 close_me_head = NULL;
2560 last_bg_pid = 0;
2561
2562 /* Initialize some more globals to non-zero values */
2563 set_cwd();
2564 job_list = &joblist_end;
2565#ifdef BB_FEATURE_COMMAND_EDITING
2566 cmdedit_set_initial_prompt();
2567#else
2568 PS1 = NULL;
2569#endif
2570 PS2 = "> ";
2571
2572 /* initialize our shell local variables with the values
2573 * currently living in the environment */
2574 if (e) {
2575 for (; *e; e++)
2576 set_local_var(*e, 2); /* without call putenv() */
2577 }
2578
2579 last_return_code=EXIT_SUCCESS;
2580
Eric Andersen25f27032001-04-26 23:22:31 +00002581
Eric Andersenbfae2522001-05-17 00:14:27 +00002582 /* If we get started under a job aware app (like bash
2583 * for example), make sure we are now in charge so we
2584 * don't fight over who gets the foreground */
Eric Andersenbafd94f2001-05-02 16:11:59 +00002585 /* don't pay any attention to this signal; it just confuses
2586 things and isn't really meant for shells anyway */
2587 signal(SIGTTOU, SIG_IGN);
Eric Andersenbfae2522001-05-17 00:14:27 +00002588 setpgid(0, getpid());
2589 tcsetpgrp(fileno(stderr), getpid());
Eric Andersenbafd94f2001-05-02 16:11:59 +00002590
Eric Andersen25f27032001-04-26 23:22:31 +00002591 if (argv[0] && argv[0][0] == '-') {
2592 debug_printf("\nsourcing /etc/profile\n");
2593 input = xfopen("/etc/profile", "r");
2594 mark_open(fileno(input));
2595 parse_file_outer(input);
2596 mark_closed(fileno(input));
2597 fclose(input);
2598 }
2599 input=stdin;
2600
Eric Andersen25f27032001-04-26 23:22:31 +00002601 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
2602 switch (opt) {
2603 case 'c':
2604 {
2605 global_argv = argv+optind;
2606 global_argc = argc-optind;
2607 opt = parse_string_outer(optarg);
Eric Andersene67c3ce2001-05-02 02:09:36 +00002608 goto final_return;
Eric Andersen25f27032001-04-26 23:22:31 +00002609 }
2610 break;
2611 case 'i':
2612 interactive++;
2613 break;
2614 case 'f':
2615 fake_mode++;
2616 break;
2617 default:
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00002618#ifndef BB_VER
Eric Andersen25f27032001-04-26 23:22:31 +00002619 fprintf(stderr, "Usage: sh [FILE]...\n"
2620 " or: sh -c command [args]...\n\n");
2621 exit(EXIT_FAILURE);
Eric Andersen9ffb7dd2001-05-19 03:00:46 +00002622#else
2623 show_usage();
2624#endif
Eric Andersen25f27032001-04-26 23:22:31 +00002625 }
2626 }
2627 /* A shell is interactive if the `-i' flag was given, or if all of
2628 * the following conditions are met:
2629 * no -c command
2630 * no arguments remaining or the -s flag given
2631 * standard input is a terminal
2632 * standard output is a terminal
2633 * Refer to Posix.2, the description of the `sh' utility. */
2634 if (argv[optind]==NULL && input==stdin &&
2635 isatty(fileno(stdin)) && isatty(fileno(stdout))) {
2636 interactive++;
2637 }
Eric Andersene67c3ce2001-05-02 02:09:36 +00002638
2639 debug_printf("\ninteractive=%d\n", interactive);
Eric Andersen25f27032001-04-26 23:22:31 +00002640 if (interactive) {
2641 /* Looks like they want an interactive shell */
2642 fprintf(stdout, "\nhush -- the humble shell v0.01 (testing)\n\n");
Eric Andersenada18ff2001-05-21 16:18:22 +00002643 grab_tty_control();
2644 }
2645 if (argv[optind]==NULL) {
Eric Andersene67c3ce2001-05-02 02:09:36 +00002646 opt=parse_file_outer(stdin);
2647 goto final_return;
Eric Andersen25f27032001-04-26 23:22:31 +00002648 }
Eric Andersen25f27032001-04-26 23:22:31 +00002649
2650 debug_printf("\nrunning script '%s'\n", argv[optind]);
2651 global_argv = argv+optind;
2652 global_argc = argc-optind;
2653 input = xfopen(argv[optind], "r");
2654 opt = parse_file_outer(input);
2655
2656#ifdef BB_FEATURE_CLEAN_UP
Eric Andersenaeb44c42001-05-22 20:29:00 +00002657 fclose(input);
2658 if (cwd && cwd != unknown)
2659 free((char*)cwd);
2660 {
2661 struct variables *cur, *tmp;
2662 for(cur = top_vars; cur; cur = tmp) {
2663 tmp = cur->next;
2664 if (!cur->flg_read_only) {
2665 free(cur->name);
2666 free(cur->value);
2667 free(cur);
2668 }
2669 }
2670 }
Eric Andersen25f27032001-04-26 23:22:31 +00002671#endif
2672
Eric Andersene67c3ce2001-05-02 02:09:36 +00002673final_return:
2674 return(opt?opt:last_return_code);
Eric Andersen25f27032001-04-26 23:22:31 +00002675}