1 /* Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004, 2006 Free Software Foundation, Inc.
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 /* regex-posix.c -- POSIX regular expression support.
23 This code was written against Henry Spencer's famous regex package.
24 The principal reference for POSIX behavior was the man page for this
25 library, not the 1003.2 document itself. Ergo, other `POSIX'
26 libraries which do not agree with the Spencer implementation may
27 produce varying behavior. Sigh. */
33 #include <sys/types.h>
35 #include "libguile/_scm.h"
37 /* Supposedly, this file is never compiled unless we know we have
38 POSIX regular expressions. But we still put this in an #ifdef so
39 the file is CPP'able (for dependency scanning) even on systems that
40 don't have a <regex.h> header. */
46 #include <rxposix.h> /* GNU Rx library */
48 #ifdef HAVE_RX_RXPOSIX_H
49 #include <rx/rxposix.h> /* GNU Rx library on Linux */
55 #include "libguile/async.h"
56 #include "libguile/smob.h"
57 #include "libguile/symbols.h"
58 #include "libguile/vectors.h"
59 #include "libguile/strports.h"
60 #include "libguile/ports.h"
61 #include "libguile/feature.h"
62 #include "libguile/strings.h"
64 #include "libguile/validate.h"
65 #include "libguile/regex-posix.h"
67 /* This is defined by some regex libraries and omitted by others. */
72 scm_t_bits scm_tc16_regex
;
77 regfree (SCM_RGX (obj
));
78 scm_gc_free (SCM_RGX (obj
), sizeof(regex_t
), "regex");
84 SCM_SYMBOL (scm_regexp_error_key
, "regular-expression-syntax");
87 scm_regexp_error_msg (int regerrno
, regex_t
*rx
)
92 errmsg
= scm_malloc (80);
93 l
= regerror (regerrno
, rx
, errmsg
, 80);
97 errmsg
= scm_malloc (l
);
98 regerror (regerrno
, rx
, errmsg
, l
);
100 return scm_take_locale_string (errmsg
);
103 SCM_DEFINE (scm_regexp_p
, "regexp?", 1, 0, 0,
105 "Return @code{#t} if @var{obj} is a compiled regular expression,\n"
106 "or @code{#f} otherwise.")
107 #define FUNC_NAME s_scm_regexp_p
109 return scm_from_bool(SCM_RGXP (obj
));
113 SCM_DEFINE (scm_make_regexp
, "make-regexp", 1, 0, 1,
114 (SCM pat
, SCM flags
),
115 "Compile the regular expression described by @var{pat}, and\n"
116 "return the compiled regexp structure. If @var{pat} does not\n"
117 "describe a legal regular expression, @code{make-regexp} throws\n"
118 "a @code{regular-expression-syntax} error.\n"
120 "The @var{flags} arguments change the behavior of the compiled\n"
121 "regular expression. The following flags may be supplied:\n"
124 "@item regexp/icase\n"
125 "Consider uppercase and lowercase letters to be the same when\n"
127 "@item regexp/newline\n"
128 "If a newline appears in the target string, then permit the\n"
129 "@samp{^} and @samp{$} operators to match immediately after or\n"
130 "immediately before the newline, respectively. Also, the\n"
131 "@samp{.} and @samp{[^...]} operators will never match a newline\n"
132 "character. The intent of this flag is to treat the target\n"
133 "string as a buffer containing many lines of text, and the\n"
134 "regular expression as a pattern that may match a single one of\n"
136 "@item regexp/basic\n"
137 "Compile a basic (``obsolete'') regexp instead of the extended\n"
138 "(``modern'') regexps that are the default. Basic regexps do\n"
139 "not consider @samp{|}, @samp{+} or @samp{?} to be special\n"
140 "characters, and require the @samp{@{...@}} and @samp{(...)}\n"
141 "metacharacters to be backslash-escaped (@pxref{Backslash\n"
142 "Escapes}). There are several other differences between basic\n"
143 "and extended regular expressions, but these are the most\n"
145 "@item regexp/extended\n"
146 "Compile an extended regular expression rather than a basic\n"
147 "regexp. This is the default behavior; this flag will not\n"
148 "usually be needed. If a call to @code{make-regexp} includes\n"
149 "both @code{regexp/basic} and @code{regexp/extended} flags, the\n"
150 "one which comes last will override the earlier one.\n"
152 #define FUNC_NAME s_scm_make_regexp
159 SCM_VALIDATE_STRING (1, pat
);
160 SCM_VALIDATE_REST_ARGUMENT (flags
);
162 /* Examine list of regexp flags. If REG_BASIC is supplied, then
163 turn off REG_EXTENDED flag (on by default). */
164 cflags
= REG_EXTENDED
;
166 while (!scm_is_null (flag
))
168 if (scm_to_int (SCM_CAR (flag
)) == REG_BASIC
)
169 cflags
&= ~REG_EXTENDED
;
171 cflags
|= scm_to_int (SCM_CAR (flag
));
172 flag
= SCM_CDR (flag
);
175 rx
= scm_gc_malloc_pointerless (sizeof (regex_t
), "regex");
176 c_pat
= scm_to_locale_string (pat
);
177 status
= regcomp (rx
, c_pat
,
178 /* Make sure they're not passing REG_NOSUB;
179 regexp-exec assumes we're getting match data. */
180 cflags
& ~REG_NOSUB
);
184 SCM errmsg
= scm_regexp_error_msg (status
, rx
);
185 scm_gc_free (rx
, sizeof(regex_t
), "regex");
186 scm_error_scm (scm_regexp_error_key
,
187 scm_from_locale_string (FUNC_NAME
),
194 SCM_RETURN_NEWSMOB (scm_tc16_regex
, rx
);
198 SCM_DEFINE (scm_regexp_exec
, "regexp-exec", 2, 2, 0,
199 (SCM rx
, SCM str
, SCM start
, SCM flags
),
200 "Match the compiled regular expression @var{rx} against\n"
201 "@code{str}. If the optional integer @var{start} argument is\n"
202 "provided, begin matching from that position in the string.\n"
203 "Return a match structure describing the results of the match,\n"
204 "or @code{#f} if no match could be found.\n"
206 "The @var{flags} arguments change the matching behavior.\n"
207 "The following flags may be supplied:\n"
210 "@item regexp/notbol\n"
211 "Operator @samp{^} always fails (unless @code{regexp/newline}\n"
212 "is used). Use this when the beginning of the string should\n"
213 "not be considered the beginning of a line.\n"
214 "@item regexp/noteol\n"
215 "Operator @samp{$} always fails (unless @code{regexp/newline}\n"
216 "is used). Use this when the end of the string should not be\n"
217 "considered the end of a line.\n"
219 #define FUNC_NAME s_scm_regexp_exec
221 int status
, nmatches
, offset
;
224 SCM mvec
= SCM_BOOL_F
;
227 SCM_VALIDATE_RGXP (1, rx
);
228 SCM_VALIDATE_STRING (2, str
);
230 if (SCM_UNBNDP (start
))
237 substr
= scm_substring (str
, start
, SCM_UNDEFINED
);
238 offset
= scm_to_int (start
);
241 if (SCM_UNBNDP (flags
))
244 /* re_nsub doesn't account for the `subexpression' representing the
245 whole regexp, so add 1 to nmatches. */
247 nmatches
= SCM_RGX(rx
)->re_nsub
+ 1;
248 SCM_CRITICAL_SECTION_START
;
249 matches
= scm_malloc (sizeof (regmatch_t
) * nmatches
);
250 c_str
= scm_to_locale_string (substr
);
251 status
= regexec (SCM_RGX (rx
), c_str
, nmatches
, matches
,
258 /* The match vector must include a cell for the string that was matched,
260 mvec
= scm_c_make_vector (nmatches
+ 1, SCM_UNSPECIFIED
);
261 SCM_SIMPLE_VECTOR_SET(mvec
,0, str
);
262 for (i
= 0; i
< nmatches
; ++i
)
263 if (matches
[i
].rm_so
== -1)
264 SCM_SIMPLE_VECTOR_SET(mvec
, i
+1,
265 scm_cons (scm_from_int (-1), scm_from_int (-1)));
267 SCM_SIMPLE_VECTOR_SET(mvec
, i
+1,
268 scm_cons (scm_from_long (matches
[i
].rm_so
+ offset
),
269 scm_from_long (matches
[i
].rm_eo
+ offset
)));
272 SCM_CRITICAL_SECTION_END
;
274 if (status
!= 0 && status
!= REG_NOMATCH
)
275 scm_error_scm (scm_regexp_error_key
,
276 scm_from_locale_string (FUNC_NAME
),
277 scm_regexp_error_msg (status
, SCM_RGX (rx
)),
278 SCM_BOOL_F
, SCM_BOOL_F
);
284 scm_init_regex_posix ()
286 scm_tc16_regex
= scm_make_smob_type ("regexp", sizeof (regex_t
));
287 scm_set_smob_free (scm_tc16_regex
, regex_free
);
289 /* Compilation flags. */
290 scm_c_define ("regexp/basic", scm_from_long (REG_BASIC
));
291 scm_c_define ("regexp/extended", scm_from_long (REG_EXTENDED
));
292 scm_c_define ("regexp/icase", scm_from_long (REG_ICASE
));
293 scm_c_define ("regexp/newline", scm_from_long (REG_NEWLINE
));
295 /* Execution flags. */
296 scm_c_define ("regexp/notbol", scm_from_long (REG_NOTBOL
));
297 scm_c_define ("regexp/noteol", scm_from_long (REG_NOTEOL
));
299 #include "libguile/regex-posix.x"
301 scm_add_feature ("regex");