2 * Copyright (c) 2002 Tim J. Robbins.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/lib/libc/gen/wordexp.c,v 1.6 2004/06/30 13:55:08 tjr Exp $
29 #include "namespace.h"
30 #include <sys/types.h>
39 #include "un-namespace.h"
41 static int we_askshell(const char *, wordexp_t *, int);
42 static int we_check(const char *, int);
46 * Perform shell word expansion on `words' and place the resulting list
47 * of words in `we'. See wordexp(3).
49 * Specified by IEEE Std. 1003.1-2001.
52 wordexp(const char * __restrict words, wordexp_t * __restrict we, int flags)
56 if (flags & WRDE_REUSE)
58 if ((flags & WRDE_APPEND) == 0) {
61 we->we_strings = NULL;
64 if ((error = we_check(words, flags)) != 0) {
68 if ((error = we_askshell(words, we, flags)) != 0) {
77 * Use the `wordexp' /bin/sh builtin function to do most of the work
78 * in expanding the word string. This function is complicated by
82 we_askshell(const char *words, wordexp_t *we, int flags)
84 int pdes[2]; /* Pipe to child */
85 char bbuf[9]; /* Buffer for byte count */
86 char wbuf[9]; /* Buffer for word count */
87 long nwords, nbytes; /* Number of words, bytes from child */
88 long i; /* Handy integer */
89 size_t sofs; /* Offset into we->we_strings */
90 size_t vofs; /* Offset into we->we_wordv */
91 pid_t pid; /* Process ID of child */
92 int status; /* Child exit status */
93 char *ifs; /* IFS env. var. */
94 char *np, *p; /* Handy pointers */
95 char *nstrings; /* Temporary for realloc() */
96 char **nwv; /* Temporary for realloc() */
98 if ((ifs = getenv("IFS")) == NULL)
102 return (WRDE_NOSPACE); /* XXX */
103 if ((pid = fork()) < 0) {
106 return (WRDE_NOSPACE); /* XXX */
110 * We are the child; just get /bin/sh to run the wordexp
111 * builtin on `words'.
117 if (_dup2(pdes[1], STDOUT_FILENO) < 0)
120 if (asprintf(&cmd, "wordexp%c%s\n", *ifs, words) < 0)
122 if ((flags & WRDE_SHOWERR) == 0) {
123 if ((devnull = _open(_PATH_DEVNULL, O_RDWR, 0666)) < 0)
125 if (_dup2(devnull, STDERR_FILENO) < 0)
129 execl(_PATH_BSHELL, "sh", flags & WRDE_UNDEF ? "-u" : "+u",
135 * We are the parent; read the output of the shell wordexp function,
136 * which is a 32-bit hexadecimal word count, a 32-bit hexadecimal
137 * byte count (not including terminating null bytes), followed by
138 * the expanded words separated by nulls.
141 if (_read(pdes[0], wbuf, 8) != 8 || _read(pdes[0], bbuf, 8) != 8) {
143 _waitpid(pid, &status, 0);
144 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
146 wbuf[8] = bbuf[8] = '\0';
147 nwords = strtol(wbuf, NULL, 16);
148 nbytes = strtol(bbuf, NULL, 16) + nwords;
151 * Allocate or reallocate (when flags & WRDE_APPEND) the word vector
152 * and string storage buffers for the expanded words we're about to
153 * read from the child.
155 sofs = we->we_nbytes;
157 if ((flags & (WRDE_DOOFFS|WRDE_APPEND)) == (WRDE_DOOFFS|WRDE_APPEND))
159 we->we_wordc += nwords;
160 we->we_nbytes += nbytes;
161 if ((nwv = realloc(we->we_wordv, (we->we_wordc + 1 +
162 (flags & WRDE_DOOFFS ? we->we_offs : 0)) *
163 sizeof(char *))) == NULL) {
165 _waitpid(pid, &status, 0);
166 return (WRDE_NOSPACE);
169 if ((nstrings = realloc(we->we_strings, we->we_nbytes)) == NULL) {
171 _waitpid(pid, &status, 0);
172 return (WRDE_NOSPACE);
174 for (i = 0; i < vofs; i++)
175 if (we->we_wordv[i] != NULL)
176 we->we_wordv[i] += nstrings - we->we_strings;
177 we->we_strings = nstrings;
179 if (_read(pdes[0], we->we_strings + sofs, nbytes) != nbytes) {
181 _waitpid(pid, &status, 0);
182 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
185 if (_waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) ||
186 WEXITSTATUS(status) != 0) {
188 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
193 * Break the null-terminated expanded word strings out into
196 if (vofs == 0 && flags & WRDE_DOOFFS)
197 while (vofs < we->we_offs)
198 we->we_wordv[vofs++] = NULL;
199 p = we->we_strings + sofs;
200 while (nwords-- != 0) {
201 we->we_wordv[vofs++] = p;
202 if ((np = memchr(p, '\0', nbytes)) == NULL)
203 return (WRDE_NOSPACE); /* XXX */
204 nbytes -= np - p + 1;
207 we->we_wordv[vofs] = NULL;
214 * Check that the string contains none of the following unquoted
215 * special characters: <newline> |&;<>(){}
216 * or command substitutions when WRDE_NOCMD is set in flags.
219 we_check(const char *words, int flags)
222 int dquote, level, quote, squote;
224 quote = squote = dquote = 0;
225 while ((c = *words++) != '\0') {
231 if (quote + dquote == 0)
235 if (quote + squote == 0)
239 if (quote + squote == 0 && flags & WRDE_NOCMD)
240 return (WRDE_CMDSUB);
241 while ((c = *words++) != '\0' && c != '`')
242 if (c == '\\' && (c = *words++) == '\0')
245 return (WRDE_SYNTAX);
247 case '|': case '&': case ';': case '<': case '>':
248 case '{': case '}': case '(': case ')': case '\n':
249 if (quote + squote + dquote == 0)
250 return (WRDE_BADCHAR);
253 if ((c = *words++) == '\0')
255 else if (quote + squote == 0 && c == '(') {
256 if (flags & WRDE_NOCMD && *words != '(')
257 return (WRDE_CMDSUB);
259 while ((c = *words++) != '\0') {
261 if ((c = *words++) == '\0')
265 else if (c == ')' && --level == 0)
268 if (c == '\0' || level != 0)
269 return (WRDE_SYNTAX);
270 } else if (quote + squote == 0 && c == '{') {
272 while ((c = *words++) != '\0') {
274 if ((c = *words++) == '\0')
278 else if (c == '}' && --level == 0)
281 if (c == '\0' || level != 0)
282 return (WRDE_SYNTAX);
291 if (quote + squote + dquote != 0)
292 return (WRDE_SYNTAX);
299 * Free the result of wordexp(). See wordexp(3).
301 * Specified by IEEE Std. 1003.1-2001.
304 wordfree(wordexp_t *we)
310 free(we->we_strings);
312 we->we_strings = NULL;