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 "pcreposix.h"
52 /* Corresponding tables of PCRE error messages and POSIX error codes. */
54 static const char *const estring[] = {
55 ERR1, ERR2, ERR3, ERR4, ERR5, ERR6, ERR7, ERR8, ERR9, ERR10,
56 ERR11, ERR12, ERR13, ERR14, ERR15, ERR16, ERR17, ERR18, ERR19, ERR20,
57 ERR21, ERR22, ERR23, ERR24, ERR25, ERR26, ERR27, ERR29, ERR29, ERR30,
58 ERR31, ERR32, ERR33, ERR34, ERR35, ERR36, ERR37, ERR38, ERR39, ERR40,
59 ERR41, ERR42, ERR43, ERR44, ERR45, ERR46, ERR47 };
61 static const int eint[] = {
62 REG_EESCAPE, /* "\\ at end of pattern" */
63 REG_EESCAPE, /* "\\c at end of pattern" */
64 REG_EESCAPE, /* "unrecognized character follows \\" */
65 REG_BADBR, /* "numbers out of order in {} quantifier" */
66 REG_BADBR, /* "number too big in {} quantifier" */
67 REG_EBRACK, /* "missing terminating ] for character class" */
68 REG_ECTYPE, /* "invalid escape sequence in character class" */
69 REG_ERANGE, /* "range out of order in character class" */
70 REG_BADRPT, /* "nothing to repeat" */
71 REG_BADRPT, /* "operand of unlimited repeat could match the empty string" */
72 REG_ASSERT, /* "internal error: unexpected repeat" */
73 REG_BADPAT, /* "unrecognized character after (?" */
74 REG_BADPAT, /* "POSIX named classes are supported only within a class" */
75 REG_EPAREN, /* "missing )" */
76 REG_ESUBREG, /* "reference to non-existent subpattern" */
77 REG_INVARG, /* "erroffset passed as NULL" */
78 REG_INVARG, /* "unknown option bit(s) set" */
79 REG_EPAREN, /* "missing ) after comment" */
80 REG_ESIZE, /* "parentheses nested too deeply" */
81 REG_ESIZE, /* "regular expression too large" */
82 REG_ESPACE, /* "failed to get memory" */
83 REG_EPAREN, /* "unmatched brackets" */
84 REG_ASSERT, /* "internal error: code overflow" */
85 REG_BADPAT, /* "unrecognized character after (?<" */
86 REG_BADPAT, /* "lookbehind assertion is not fixed length" */
87 REG_BADPAT, /* "malformed number after (?(" */
88 REG_BADPAT, /* "conditional group containe more than two branches" */
89 REG_BADPAT, /* "assertion expected after (?(" */
90 REG_BADPAT, /* "(?R or (?digits must be followed by )" */
91 REG_ECTYPE, /* "unknown POSIX class name" */
92 REG_BADPAT, /* "POSIX collating elements are not supported" */
93 REG_INVARG, /* "this version of PCRE is not compiled with PCRE_UTF8 support" */
94 REG_BADPAT, /* "spare error" */
95 REG_BADPAT, /* "character value in \x{...} sequence is too large" */
96 REG_BADPAT, /* "invalid condition (?(0)" */
97 REG_BADPAT, /* "\\C not allowed in lookbehind assertion" */
98 REG_EESCAPE, /* "PCRE does not support \\L, \\l, \\N, \\U, or \\u" */
99 REG_BADPAT, /* "number after (?C is > 255" */
100 REG_BADPAT, /* "closing ) for (?C expected" */
101 REG_BADPAT, /* "recursive call could loop indefinitely" */
102 REG_BADPAT, /* "unrecognized character after (?P" */
103 REG_BADPAT, /* "syntax error after (?P" */
104 REG_BADPAT, /* "two named groups have the same name" */
105 REG_BADPAT, /* "invalid UTF-8 string" */
106 REG_BADPAT, /* "support for \\P, \\p, and \\X has not been compiled" */
107 REG_BADPAT, /* "malformed \\P or \\p sequence" */
108 REG_BADPAT /* "unknown property name after \\P or \\p" */
111 /* Table of texts corresponding to POSIX error codes */
113 static const char *const pstring[] = {
114 "", /* Dummy for value 0 */
115 "internal error", /* REG_ASSERT */
116 "invalid repeat counts in {}", /* BADBR */
117 "pattern error", /* BADPAT */
118 "? * + invalid", /* BADRPT */
119 "unbalanced {}", /* EBRACE */
120 "unbalanced []", /* EBRACK */
121 "collation error - not relevant", /* ECOLLATE */
122 "bad class", /* ECTYPE */
123 "bad escape sequence", /* EESCAPE */
124 "empty expression", /* EMPTY */
125 "unbalanced ()", /* EPAREN */
126 "bad range inside []", /* ERANGE */
127 "expression too big", /* ESIZE */
128 "failed to get memory", /* ESPACE */
129 "bad back reference", /* ESUBREG */
130 "bad argument", /* INVARG */
131 "match failed" /* NOMATCH */
137 /*************************************************
138 * Translate PCRE text code to int *
139 *************************************************/
141 /* PCRE compile-time errors are given as strings defined as macros. We can just
142 look them up in a table to turn them into POSIX-style error codes. */
145 pcre_posix_error_code(const char *s)
148 for (i = 0; i < sizeof(estring)/sizeof(char *); i++)
149 if (strcmp(s, estring[i]) == 0) return eint[i];
155 /*************************************************
156 * Translate error code to string *
157 *************************************************/
160 regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
162 const char *message, *addmessage;
163 size_t length, addlength;
165 message = (errcode >= (int)(sizeof(pstring)/sizeof(char *)))?
166 "unknown error code" : pstring[errcode];
167 length = strlen(message) + 1;
169 addmessage = " at offset ";
170 addlength = (preg != NULL && (int)preg->re_erroffset != -1)?
171 strlen(addmessage) + 6 : 0;
175 if (addlength > 0 && errbuf_size >= length + addlength)
176 sprintf(errbuf, "%s%s%-6d", message, addmessage, (int)preg->re_erroffset);
179 strncpy(errbuf, message, errbuf_size - 1);
180 errbuf[errbuf_size-1] = 0;
184 return length + addlength;
190 /*************************************************
191 * Free store held by a regex *
192 *************************************************/
195 regfree(regex_t *preg)
197 (pcre_free)(preg->re_pcre);
203 /*************************************************
204 * Compile a regular expression *
205 *************************************************/
209 preg points to a structure for recording the compiled expression
210 pattern the pattern to compile
211 cflags compilation flags
213 Returns: 0 on success
214 various non-zero codes on failure
218 regcomp(regex_t *preg, const char *pattern, int cflags)
220 const char *errorptr;
224 if ((cflags & REG_ICASE) != 0) options |= PCRE_CASELESS;
225 if ((cflags & REG_NEWLINE) != 0) options |= PCRE_MULTILINE;
227 preg->re_pcre = pcre_compile(pattern, options, &errorptr, &erroffset, NULL);
228 preg->re_erroffset = erroffset;
230 if (preg->re_pcre == NULL) return pcre_posix_error_code(errorptr);
232 preg->re_nsub = pcre_info((const pcre *)preg->re_pcre, NULL, NULL);
239 /*************************************************
240 * Match a regular expression *
241 *************************************************/
243 /* Unfortunately, PCRE requires 3 ints of working space for each captured
244 substring, so we have to get and release working store instead of just using
245 the POSIX structures as was done in earlier releases when PCRE needed only 2
246 ints. However, if the number of possible capturing brackets is small, use a
247 block of store on the stack, to reduce the use of malloc/free. The threshold is
248 in a macro that can be changed at configure time. */
251 regexec(const regex_t *preg, const char *string, size_t nmatch,
252 regmatch_t pmatch[], int eflags)
257 int small_ovector[POSIX_MALLOC_THRESHOLD * 3];
258 BOOL allocated_ovector = FALSE;
260 if ((eflags & REG_NOTBOL) != 0) options |= PCRE_NOTBOL;
261 if ((eflags & REG_NOTEOL) != 0) options |= PCRE_NOTEOL;
263 ((regex_t *)preg)->re_erroffset = (size_t)(-1); /* Only has meaning after compile */
267 if (nmatch <= POSIX_MALLOC_THRESHOLD)
269 ovector = &(small_ovector[0]);
273 ovector = (int *)malloc(sizeof(int) * nmatch * 3);
274 if (ovector == NULL) return REG_ESPACE;
275 allocated_ovector = TRUE;
279 rc = pcre_exec((const pcre *)preg->re_pcre, NULL, string, (int)strlen(string),
280 0, options, ovector, nmatch * 3);
282 if (rc == 0) rc = nmatch; /* All captured slots were filled in */
287 for (i = 0; i < (size_t)rc; i++)
289 pmatch[i].rm_so = ovector[i*2];
290 pmatch[i].rm_eo = ovector[i*2+1];
292 if (allocated_ovector) free(ovector);
293 for (; i < nmatch; i++) pmatch[i].rm_so = pmatch[i].rm_eo = -1;
299 if (allocated_ovector) free(ovector);
302 case PCRE_ERROR_NOMATCH: return REG_NOMATCH;
303 case PCRE_ERROR_NULL: return REG_INVARG;
304 case PCRE_ERROR_BADOPTION: return REG_INVARG;
305 case PCRE_ERROR_BADMAGIC: return REG_INVARG;
306 case PCRE_ERROR_UNKNOWN_NODE: return REG_ASSERT;
307 case PCRE_ERROR_NOMEMORY: return REG_ESPACE;
308 case PCRE_ERROR_MATCHLIMIT: return REG_ESPACE;
309 case PCRE_ERROR_BADUTF8: return REG_INVARG;
310 case PCRE_ERROR_BADUTF8_OFFSET: return REG_INVARG;
311 default: return REG_ASSERT;
316 /* End of pcreposix.c */