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>
40 #include "un-namespace.h"
42 static int we_askshell(const char *, wordexp_t *, int);
43 static int we_check(const char *, int);
47 * Perform shell word expansion on `words' and place the resulting list
48 * of words in `we'. See wordexp(3).
50 * Specified by IEEE Std. 1003.1-2001.
53 wordexp(const char * __restrict words, wordexp_t * __restrict we, int flags)
57 if (flags & WRDE_REUSE)
59 if ((flags & WRDE_APPEND) == 0) {
62 we->we_strings = NULL;
65 if ((error = we_check(words, flags)) != 0) {
69 if ((error = we_askshell(words, we, flags)) != 0) {
78 * Use the `wordexp' /bin/sh builtin function to do most of the work
79 * in expanding the word string. This function is complicated by
83 we_askshell(const char *words, wordexp_t *we, int flags)
85 int pdes[2]; /* Pipe to child */
86 char bbuf[9]; /* Buffer for byte count */
87 char wbuf[9]; /* Buffer for word count */
88 long nwords, nbytes; /* Number of words, bytes from child */
89 long i; /* Handy integer */
90 size_t sofs; /* Offset into we->we_strings */
91 size_t vofs; /* Offset into we->we_wordv */
92 pid_t pid; /* Process ID of child */
93 int status; /* Child exit status */
94 char *ifs; /* IFS env. var. */
95 char *np, *p; /* Handy pointers */
96 char *nstrings; /* Temporary for realloc() */
97 char **nwv; /* Temporary for realloc() */
99 if ((ifs = getenv("IFS")) == NULL)
102 if (pipe2(pdes, O_CLOEXEC) < 0)
103 return (WRDE_NOSPACE); /* XXX */
104 if ((pid = fork()) < 0) {
107 return (WRDE_NOSPACE); /* XXX */
111 * We are the child; just get /bin/sh to run the wordexp
112 * builtin on `words'.
118 _fcntl(pdes[1], F_SETFD, 0);
119 if (_dup2(pdes[1], STDOUT_FILENO) < 0)
122 if (asprintf(&cmd, "wordexp%c%s\n", *ifs, words) < 0)
124 if ((flags & WRDE_SHOWERR) == 0) {
125 if ((devnull = _open(_PATH_DEVNULL, O_RDWR, 0666)) < 0)
127 if (_dup2(devnull, STDERR_FILENO) < 0)
131 execl(_PATH_BSHELL, "sh", flags & WRDE_UNDEF ? "-u" : "+u",
137 * We are the parent; read the output of the shell wordexp function,
138 * which is a 32-bit hexadecimal word count, a 32-bit hexadecimal
139 * byte count (not including terminating null bytes), followed by
140 * the expanded words separated by nulls.
143 if (_read(pdes[0], wbuf, 8) != 8 || _read(pdes[0], bbuf, 8) != 8) {
145 _waitpid(pid, &status, 0);
146 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
148 wbuf[8] = bbuf[8] = '\0';
149 nwords = strtol(wbuf, NULL, 16);
150 nbytes = strtol(bbuf, NULL, 16) + nwords;
153 * Allocate or reallocate (when flags & WRDE_APPEND) the word vector
154 * and string storage buffers for the expanded words we're about to
155 * read from the child.
157 sofs = we->we_nbytes;
159 if ((flags & (WRDE_DOOFFS|WRDE_APPEND)) == (WRDE_DOOFFS|WRDE_APPEND))
161 we->we_wordc += nwords;
162 we->we_nbytes += nbytes;
163 if ((nwv = realloc(we->we_wordv, (we->we_wordc + 1 +
164 (flags & WRDE_DOOFFS ? we->we_offs : 0)) *
165 sizeof(char *))) == NULL) {
167 _waitpid(pid, &status, 0);
168 return (WRDE_NOSPACE);
171 if ((nstrings = realloc(we->we_strings, we->we_nbytes)) == NULL) {
173 _waitpid(pid, &status, 0);
174 return (WRDE_NOSPACE);
176 for (i = 0; i < vofs; i++)
177 if (we->we_wordv[i] != NULL)
178 we->we_wordv[i] += nstrings - we->we_strings;
179 we->we_strings = nstrings;
181 if (_read(pdes[0], we->we_strings + sofs, nbytes) != nbytes) {
183 _waitpid(pid, &status, 0);
184 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
187 if (_waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) ||
188 WEXITSTATUS(status) != 0) {
190 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
195 * Break the null-terminated expanded word strings out into
198 if (vofs == 0 && flags & WRDE_DOOFFS)
199 while (vofs < we->we_offs)
200 we->we_wordv[vofs++] = NULL;
201 p = we->we_strings + sofs;
202 while (nwords-- != 0) {
203 we->we_wordv[vofs++] = p;
204 if ((np = memchr(p, '\0', nbytes)) == NULL)
205 return (WRDE_NOSPACE); /* XXX */
206 nbytes -= np - p + 1;
209 we->we_wordv[vofs] = NULL;
216 * Check that the string contains none of the following unquoted
217 * special characters: <newline> |&;<>(){}
218 * or command substitutions when WRDE_NOCMD is set in flags.
221 we_check(const char *words, int flags)
224 int dquote, level, quote, squote;
226 quote = squote = dquote = 0;
227 while ((c = *words++) != '\0') {
233 if (quote + dquote == 0)
237 if (quote + squote == 0)
241 if (quote + squote == 0 && flags & WRDE_NOCMD)
242 return (WRDE_CMDSUB);
243 while ((c = *words++) != '\0' && c != '`')
244 if (c == '\\' && (c = *words++) == '\0')
247 return (WRDE_SYNTAX);
249 case '|': case '&': case ';': case '<': case '>':
250 case '{': case '}': case '(': case ')': case '\n':
251 if (quote + squote + dquote == 0)
252 return (WRDE_BADCHAR);
255 if ((c = *words++) == '\0')
257 else if (quote + squote == 0 && c == '(') {
258 if (flags & WRDE_NOCMD && *words != '(')
259 return (WRDE_CMDSUB);
261 while ((c = *words++) != '\0') {
263 if ((c = *words++) == '\0')
267 else if (c == ')' && --level == 0)
270 if (c == '\0' || level != 0)
271 return (WRDE_SYNTAX);
272 } else if (quote + squote == 0 && c == '{') {
274 while ((c = *words++) != '\0') {
276 if ((c = *words++) == '\0')
280 else if (c == '}' && --level == 0)
283 if (c == '\0' || level != 0)
284 return (WRDE_SYNTAX);
293 if (quote + squote + dquote != 0)
294 return (WRDE_SYNTAX);
301 * Free the result of wordexp(). See wordexp(3).
303 * Specified by IEEE Std. 1003.1-2001.
306 wordfree(wordexp_t *we)
312 free(we->we_strings);
314 we->we_strings = NULL;