xref: /freebsd/lib/libcompat/4.3/re_comp.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*-
2  * Copyright (c) 1992 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * James da Silva at the University of Maryland at College Park.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 /*
37  * Compatibility routines that implement the old re_comp/re_exec interface in
38  * terms of the regcomp/regexec interface.  It's possible that some programs
39  * rely on dark corners of re_comp/re_exec and won't work with this version,
40  * but most programs should be fine.
41  */
42 
43 #if defined(LIBC_SCCS) && !defined(lint)
44 static char sccsid[] = "@(#)regex.c	5.1 (Berkeley) 3/29/92";
45 #endif /* LIBC_SCCS and not lint */
46 
47 #include <regex.h>
48 #include <stddef.h>
49 #include <unistd.h>
50 
51 static regex_t re_regexp;
52 static int re_gotexp;
53 static char re_errstr[100];
54 
55 char *
56 re_comp(const char *s)
57 {
58 	int rc;
59 
60 	if (s == NULL || *s == '\0') {
61 		if (!re_gotexp)
62 			return __DECONST(char *,
63 			    "no previous regular expression");
64 		return (NULL);
65 	}
66 
67 	if (re_gotexp) {
68 		regfree(&re_regexp);
69 		re_gotexp = 0;
70 	}
71 
72 	rc = regcomp(&re_regexp, s, REG_EXTENDED);
73 	if (rc == 0) {
74 		re_gotexp = 1;
75 		return (NULL);
76 	}
77 
78 	regerror(rc, &re_regexp, re_errstr, sizeof(re_errstr));
79 	re_errstr[sizeof(re_errstr) - 1] = '\0';
80 	return (re_errstr);
81 }
82 
83 int
84 re_exec(const char *s)
85 {
86 	int rc;
87 
88 	if (!re_gotexp)
89 		return (-1);
90 	rc = regexec(&re_regexp, s, 0, NULL, 0);
91 	return (rc == 0 ? 1 : 0);
92 }
93