2 * Copyright (c) 2002 Tim J. Robbins.
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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
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12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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26 * $FreeBSD: src/lib/libc/gen/wordexp.c,v 1.6 2004/06/30 13:55:08 tjr Exp $
27 * $DragonFly: src/lib/libc/gen/wordexp.c,v 1.1 2008/10/06 21:01:37 swildner Exp $
30 #include <sys/types.h>
40 static int we_askshell(const char *, wordexp_t *, int);
41 static int we_check(const char *, int);
45 * Perform shell word expansion on `words' and place the resulting list
46 * of words in `we'. See wordexp(3).
48 * Specified by IEEE Std. 1003.1-2001.
51 wordexp(const char * __restrict words, wordexp_t * __restrict we, int flags)
55 if (flags & WRDE_REUSE)
57 if ((flags & WRDE_APPEND) == 0) {
60 we->we_strings = NULL;
63 if ((error = we_check(words, flags)) != 0) {
67 if ((error = we_askshell(words, we, flags)) != 0) {
76 * Use the `wordexp' /bin/sh builtin function to do most of the work
77 * in expanding the word string. This function is complicated by
81 we_askshell(const char *words, wordexp_t *we, int flags)
83 int pdes[2]; /* Pipe to child */
84 char bbuf[9]; /* Buffer for byte count */
85 char wbuf[9]; /* Buffer for word count */
86 long nwords, nbytes; /* Number of words, bytes from child */
87 long i; /* Handy integer */
88 size_t sofs; /* Offset into we->we_strings */
89 size_t vofs; /* Offset into we->we_wordv */
90 pid_t pid; /* Process ID of child */
91 int status; /* Child exit status */
92 char *ifs; /* IFS env. var. */
93 char *np, *p; /* Handy pointers */
94 char *nstrings; /* Temporary for realloc() */
95 char **nwv; /* Temporary for realloc() */
97 if ((ifs = getenv("IFS")) == NULL)
101 return (WRDE_NOSPACE); /* XXX */
102 if ((pid = fork()) < 0) {
105 return (WRDE_NOSPACE); /* XXX */
109 * We are the child; just get /bin/sh to run the wordexp
110 * builtin on `words'.
116 if (_dup2(pdes[1], STDOUT_FILENO) < 0)
119 if (asprintf(&cmd, "wordexp%c%s\n", *ifs, words) < 0)
121 if ((flags & WRDE_SHOWERR) == 0) {
122 if ((devnull = _open(_PATH_DEVNULL, O_RDWR, 0666)) < 0)
124 if (_dup2(devnull, STDERR_FILENO) < 0)
128 execl(_PATH_BSHELL, "sh", flags & WRDE_UNDEF ? "-u" : "+u",
129 "-c", cmd, (char *)NULL);
134 * We are the parent; read the output of the shell wordexp function,
135 * which is a 32-bit hexadecimal word count, a 32-bit hexadecimal
136 * byte count (not including terminating null bytes), followed by
137 * the expanded words separated by nulls.
140 if (_read(pdes[0], wbuf, 8) != 8 || _read(pdes[0], bbuf, 8) != 8) {
142 _waitpid(pid, &status, 0);
143 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
145 wbuf[8] = bbuf[8] = '\0';
146 nwords = strtol(wbuf, NULL, 16);
147 nbytes = strtol(bbuf, NULL, 16) + nwords;
150 * Allocate or reallocate (when flags & WRDE_APPEND) the word vector
151 * and string storage buffers for the expanded words we're about to
152 * read from the child.
154 sofs = we->we_nbytes;
156 if ((flags & (WRDE_DOOFFS|WRDE_APPEND)) == (WRDE_DOOFFS|WRDE_APPEND))
158 we->we_wordc += nwords;
159 we->we_nbytes += nbytes;
160 if ((nwv = realloc(we->we_wordv, (we->we_wordc + 1 +
161 (flags & WRDE_DOOFFS ? we->we_offs : 0)) *
162 sizeof(char *))) == NULL) {
164 _waitpid(pid, &status, 0);
165 return (WRDE_NOSPACE);
168 if ((nstrings = realloc(we->we_strings, we->we_nbytes)) == NULL) {
170 _waitpid(pid, &status, 0);
171 return (WRDE_NOSPACE);
173 for (i = 0; i < vofs; i++)
174 if (we->we_wordv[i] != NULL)
175 we->we_wordv[i] += nstrings - we->we_strings;
176 we->we_strings = nstrings;
178 if (_read(pdes[0], we->we_strings + sofs, nbytes) != nbytes) {
180 _waitpid(pid, &status, 0);
181 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
184 if (_waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) ||
185 WEXITSTATUS(status) != 0) {
187 return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX);
192 * Break the null-terminated expanded word strings out into
195 if (vofs == 0 && flags & WRDE_DOOFFS)
196 while (vofs < we->we_offs)
197 we->we_wordv[vofs++] = NULL;
198 p = we->we_strings + sofs;
199 while (nwords-- != 0) {
200 we->we_wordv[vofs++] = p;
201 if ((np = memchr(p, '\0', nbytes)) == NULL)
202 return (WRDE_NOSPACE); /* XXX */
203 nbytes -= np - p + 1;
206 we->we_wordv[vofs] = NULL;
213 * Check that the string contains none of the following unquoted
214 * special characters: <newline> |&;<>(){}
215 * or command substitutions when WRDE_NOCMD is set in flags.
218 we_check(const char *words, int flags)
221 int dquote, level, quote, squote;
223 quote = squote = dquote = 0;
224 while ((c = *words++) != '\0') {
230 if (quote + dquote == 0)
234 if (quote + squote == 0)
238 if (quote + squote == 0 && flags & WRDE_NOCMD)
239 return (WRDE_CMDSUB);
240 while ((c = *words++) != '\0' && c != '`')
241 if (c == '\\' && (c = *words++) == '\0')
244 return (WRDE_SYNTAX);
246 case '|': case '&': case ';': case '<': case '>':
247 case '{': case '}': case '(': case ')': case '\n':
248 if (quote + squote + dquote == 0)
249 return (WRDE_BADCHAR);
252 if ((c = *words++) == '\0')
254 else if (quote + squote == 0 && c == '(') {
255 if (flags & WRDE_NOCMD && *words != '(')
256 return (WRDE_CMDSUB);
258 while ((c = *words++) != '\0') {
260 if ((c = *words++) == '\0')
264 else if (c == ')' && --level == 0)
267 if (c == '\0' || level != 0)
268 return (WRDE_SYNTAX);
269 } else if (quote + squote == 0 && c == '{') {
271 while ((c = *words++) != '\0') {
273 if ((c = *words++) == '\0')
277 else if (c == '}' && --level == 0)
280 if (c == '\0' || level != 0)
281 return (WRDE_SYNTAX);
290 if (quote + squote + dquote != 0)
291 return (WRDE_SYNTAX);
298 * Free the result of wordexp(). See wordexp(3).
300 * Specified by IEEE Std. 1003.1-2001.
303 wordfree(wordexp_t *we)
309 free(we->we_strings);
311 we->we_strings = NULL;