1 /*************************************************
2 * Perl-Compatible Regular Expressions *
3 *************************************************/
6 This is a library of functions to support regular expressions whose syntax
7 and semantics are as close as possible to those of the Perl 5 language. See
8 the file Tech.Notes for some information on the internals.
10 This module is a wrapper that provides a POSIX API to the underlying PCRE
13 Written by: Philip Hazel <ph10@cam.ac.uk>
15 Copyright (c) 1997-2004 University of Cambridge
17 -----------------------------------------------------------------------------
18 Redistribution and use in source and binary forms, with or without
19 modification, are permitted provided that the following conditions are met:
21 * Redistributions of source code must retain the above copyright notice,
22 this list of conditions and the following disclaimer.
24 * Redistributions in binary form must reproduce the above copyright
25 notice, this list of conditions and the following disclaimer in the
26 documentation and/or other materials provided with the distribution.
28 * Neither the name of the University of Cambridge nor the names of its
29 contributors may be used to endorse or promote products derived from
30 this software without specific prior written permission.
32 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
33 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
36 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
37 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
38 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
39 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
40 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
41 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 POSSIBILITY OF SUCH DAMAGE.
43 -----------------------------------------------------------------------------
47 #include "apr_strings.h"
50 #define APR_WANT_STRFUNC
53 #ifndef POSIX_MALLOC_THRESHOLD
54 #define POSIX_MALLOC_THRESHOLD (10)
57 /* Table of error strings corresponding to POSIX error codes; must be
58 * kept in synch with include/ap_regex.h's AP_REG_E* definitions. */
60 static const char *const pstring[] = {
61 "", /* Dummy for value 0 */
62 "internal error", /* AP_REG_ASSERT */
63 "failed to get memory", /* AP_REG_ESPACE */
64 "bad argument", /* AP_REG_INVARG */
65 "match failed" /* AP_REG_NOMATCH */
68 AP_DECLARE(apr_size_t) ap_regerror(int errcode, const ap_regex_t *preg,
69 char *errbuf, apr_size_t errbuf_size)
71 const char *message, *addmessage;
72 apr_size_t length, addlength;
74 message = (errcode >= (int)(sizeof(pstring)/sizeof(char *)))?
75 "unknown error code" : pstring[errcode];
76 length = strlen(message) + 1;
78 addmessage = " at offset ";
79 addlength = (preg != NULL && (int)preg->re_erroffset != -1)?
80 strlen(addmessage) + 6 : 0;
84 if (addlength > 0 && errbuf_size >= length + addlength)
85 apr_snprintf(errbuf, sizeof errbuf,
86 "%s%s%-6d", message, addmessage, (int)preg->re_erroffset);
89 strncpy(errbuf, message, errbuf_size - 1);
90 errbuf[errbuf_size-1] = 0;
94 return length + addlength;
100 /*************************************************
101 * Free store held by a regex *
102 *************************************************/
104 AP_DECLARE(void) ap_regfree(ap_regex_t *preg)
106 (pcre_free)(preg->re_pcre);
112 /*************************************************
113 * Compile a regular expression *
114 *************************************************/
118 preg points to a structure for recording the compiled expression
119 pattern the pattern to compile
120 cflags compilation flags
122 Returns: 0 on success
123 various non-zero codes on failure
126 AP_DECLARE(int) ap_regcomp(ap_regex_t *preg, const char *pattern, int cflags)
128 const char *errorptr;
132 if ((cflags & AP_REG_ICASE) != 0) options |= PCRE_CASELESS;
133 if ((cflags & AP_REG_NEWLINE) != 0) options |= PCRE_MULTILINE;
135 preg->re_pcre = pcre_compile(pattern, options, &errorptr, &erroffset, NULL);
136 preg->re_erroffset = erroffset;
138 if (preg->re_pcre == NULL) return AP_REG_INVARG;
140 preg->re_nsub = pcre_info((const pcre *)preg->re_pcre, NULL, NULL);
147 /*************************************************
148 * Match a regular expression *
149 *************************************************/
151 /* Unfortunately, PCRE requires 3 ints of working space for each captured
152 substring, so we have to get and release working store instead of just using
153 the POSIX structures as was done in earlier releases when PCRE needed only 2
154 ints. However, if the number of possible capturing brackets is small, use a
155 block of store on the stack, to reduce the use of malloc/free. The threshold is
156 in a macro that can be changed at configure time. */
158 AP_DECLARE(int) ap_regexec(const ap_regex_t *preg, const char *string,
159 apr_size_t nmatch, ap_regmatch_t pmatch[],
165 int small_ovector[POSIX_MALLOC_THRESHOLD * 3];
166 int allocated_ovector = 0;
168 if ((eflags & AP_REG_NOTBOL) != 0) options |= PCRE_NOTBOL;
169 if ((eflags & AP_REG_NOTEOL) != 0) options |= PCRE_NOTEOL;
171 ((ap_regex_t *)preg)->re_erroffset = (apr_size_t)(-1); /* Only has meaning after compile */
175 if (nmatch <= POSIX_MALLOC_THRESHOLD)
177 ovector = &(small_ovector[0]);
181 ovector = (int *)malloc(sizeof(int) * nmatch * 3);
182 if (ovector == NULL) return AP_REG_ESPACE;
183 allocated_ovector = 1;
187 rc = pcre_exec((const pcre *)preg->re_pcre, NULL, string, (int)strlen(string),
188 0, options, ovector, nmatch * 3);
190 if (rc == 0) rc = nmatch; /* All captured slots were filled in */
195 for (i = 0; i < (apr_size_t)rc; i++)
197 pmatch[i].rm_so = ovector[i*2];
198 pmatch[i].rm_eo = ovector[i*2+1];
200 if (allocated_ovector) free(ovector);
201 for (; i < nmatch; i++) pmatch[i].rm_so = pmatch[i].rm_eo = -1;
207 if (allocated_ovector) free(ovector);
210 case PCRE_ERROR_NOMATCH: return AP_REG_NOMATCH;
211 case PCRE_ERROR_NULL: return AP_REG_INVARG;
212 case PCRE_ERROR_BADOPTION: return AP_REG_INVARG;
213 case PCRE_ERROR_BADMAGIC: return AP_REG_INVARG;
214 case PCRE_ERROR_UNKNOWN_NODE: return AP_REG_ASSERT;
215 case PCRE_ERROR_NOMEMORY: return AP_REG_ESPACE;
216 #ifdef PCRE_ERROR_MATCHLIMIT
217 case PCRE_ERROR_MATCHLIMIT: return AP_REG_ESPACE;
219 #ifdef PCRE_ERROR_BADUTF8
220 case PCRE_ERROR_BADUTF8: return AP_REG_INVARG;
222 #ifdef PCRE_ERROR_BADUTF8_OFFSET
223 case PCRE_ERROR_BADUTF8_OFFSET: return AP_REG_INVARG;
225 default: return AP_REG_ASSERT;
230 /* End of pcreposix.c */