1 /* Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
8 * This program 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
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this software; see the file COPYING. If not, write to
15 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
16 * Boston, MA 02111-1307 USA
18 * As a special exception, the Free Software Foundation gives permission
19 * for additional uses of the text contained in its release of GUILE.
21 * The exception is that, if you link the GUILE library with other files
22 * to produce an executable, this does not by itself cause the
23 * resulting executable to be covered by the GNU General Public License.
24 * Your use of that executable is in no way restricted on account of
25 * linking the GUILE library code into it.
27 * This exception does not however invalidate any other reasons why
28 * the executable file might be covered by the GNU General Public License.
30 * This exception applies only to the code released by the
31 * Free Software Foundation under the name GUILE. If you copy
32 * code from other Free Software Foundation releases into a copy of
33 * GUILE, as the General Public License permits, the exception does
34 * not apply to the code that you add in this way. To avoid misleading
35 * anyone as to the status of such modified files, you must delete
36 * this exception notice from them.
38 * If you write modifications of your own for GUILE, it is your choice
39 * whether to permit this exception to apply to your modifications.
40 * If you do not wish that, delete this exception notice.
43 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
44 gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
48 /* regex-posix.c -- POSIX regular expression support.
50 This code was written against Henry Spencer's famous regex package.
51 The principal reference for POSIX behavior was the man page for this
52 library, not the 1003.2 document itself. Ergo, other `POSIX'
53 libraries which do not agree with the Spencer implementation may
54 produce varying behavior. Sigh. */
57 #include <sys/types.h>
61 /* Supposedly, this file is never compiled unless we know we have
62 POSIX regular expressions. But we still put this in an #ifdef so
63 the file is CPP'able (for dependency scanning) even on systems that
64 don't have a <regex.h> header. */
70 #include <rxposix.h> /* GNU Rx library */
72 #ifdef HAVE_RX_RXPOSIX_H
73 #include <rx/rxposix.h> /* GNU Rx library on Linux */
86 #include "scm_validate.h"
87 #include "regex-posix.h"
89 /* This is defined by some regex libraries and omitted by others. */
99 regfree (SCM_RGX (obj
));
100 free (SCM_RGX (obj
));
101 return sizeof(regex_t
);
106 SCM_SYMBOL (scm_regexp_error_key
, "regular-expression-syntax");
109 scm_regexp_error_msg (int regerrno
, regex_t
*rx
)
114 /* FIXME: must we wrap any external calls in SCM_DEFER_INTS...SCM_ALLOW_INTS?
115 Or are these only necessary when a SCM object may be left in an
116 undetermined state (half-formed)? If the latter then I believe we
117 may do without the critical section code. -twp */
119 /* We could simply make errmsg a char pointer, and allocate space with
120 malloc. But since we are about to pass the pointer to scm_error, which
121 never returns, we would never have the opportunity to free it. Creating
122 it as a SCM object means that the system will GC it at some point. */
124 errmsg
= scm_make_string (SCM_MAKINUM (80), SCM_UNDEFINED
);
126 l
= regerror (regerrno
, rx
, SCM_CHARS (errmsg
), 80);
129 errmsg
= scm_make_string (SCM_MAKINUM (l
), SCM_UNDEFINED
);
130 regerror (regerrno
, rx
, SCM_CHARS (errmsg
), l
);
133 return SCM_CHARS (errmsg
);
136 GUILE_PROC (scm_regexp_p
, "regexp?", 1, 0, 0,
138 "Return @code{#t} if @var{obj} is a compiled regular expression, or
139 @code{#f} otherwise.")
140 #define FUNC_NAME s_scm_regexp_p
142 return SCM_BOOL(SCM_RGXP (x
));
146 GUILE_PROC (scm_make_regexp
, "make-regexp", 1, 0, 1,
147 (SCM pat
, SCM flags
),
148 "Compile the regular expression described by @var{str}, and return the
149 compiled regexp structure. If @var{str} does not describe a legal
150 regular expression, @code{make-regexp} throws a
151 @code{regular-expression-syntax} error.
153 The @var{flag} arguments change the behavior of the compiled regexp.
154 The following flags may be supplied:
158 Consider uppercase and lowercase letters to be the same when matching.
161 If a newline appears in the target string, then permit the @samp{^} and
162 @samp{$} operators to match immediately after or immediately before the
163 newline, respectively. Also, the @samp{.} and @samp{[^...]} operators
164 will never match a newline character. The intent of this flag is to
165 treat the target string as a buffer containing many lines of text, and
166 the regular expression as a pattern that may match a single one of those
170 Compile a basic (``obsolete'') regexp instead of the extended
171 (``modern'') regexps that are the default. Basic regexps do not
172 consider @samp{|}, @samp{+} or @samp{?} to be special characters, and
173 require the @samp{@{...@}} and @samp{(...)} metacharacters to be
174 backslash-escaped (@pxref{Backslash Escapes}). There are several other
175 differences between basic and extended regular expressions, but these
176 are the most significant.
178 @item regexp/extended
179 Compile an extended regular expression rather than a basic regexp. This
180 is the default behavior; this flag will not usually be needed. If a
181 call to @code{make-regexp} includes both @code{regexp/basic} and
182 @code{regexp/extended} flags, the one which comes last will override
186 #define FUNC_NAME s_scm_make_regexp
192 SCM_VALIDATE_ROSTRING(1,pat
);
193 SCM_COERCE_SUBSTR (pat
);
195 /* Examine list of regexp flags. If REG_BASIC is supplied, then
196 turn off REG_EXTENDED flag (on by default). */
197 cflags
= REG_EXTENDED
;
199 while (SCM_NNULLP (flag
))
201 if (SCM_INUM (SCM_CAR (flag
)) == REG_BASIC
)
202 cflags
&= ~REG_EXTENDED
;
204 cflags
|= SCM_INUM (SCM_CAR (flag
));
205 flag
= SCM_CDR (flag
);
208 rx
= SCM_MUST_MALLOC_TYPE(regex_t
);
209 status
= regcomp (rx
, SCM_ROCHARS (pat
),
210 /* Make sure they're not passing REG_NOSUB;
211 regexp-exec assumes we're getting match data. */
212 cflags
& ~REG_NOSUB
);
215 scm_error (scm_regexp_error_key
,
217 scm_regexp_error_msg (status
, rx
),
222 SCM_RETURN_NEWSMOB (scm_tc16_regex
, rx
);
226 GUILE_PROC (scm_regexp_exec
, "regexp-exec", 2, 2, 0,
227 (SCM rx
, SCM str
, SCM start
, SCM flags
),
228 "Match the compiled regular expression @var{regexp} against @code{str}.
229 If the optional integer @var{start} argument is provided, begin matching
230 from that position in the string. Return a match structure describing
231 the results of the match, or @code{#f} if no match could be found.")
232 #define FUNC_NAME s_scm_regexp_exec
234 int status
, nmatches
, offset
;
236 SCM mvec
= SCM_BOOL_F
;
238 SCM_VALIDATE_RGXP(1,rx
);
239 SCM_VALIDATE_ROSTRING(2,str
);
240 SCM_VALIDATE_INT_DEF_COPY(3,start
,0,offset
);
241 SCM_ASSERT_RANGE (3,start
,offset
>= 0 && (unsigned) offset
<= SCM_LENGTH (str
));
242 if (SCM_UNBNDP (flags
))
244 SCM_VALIDATE_INT(4,flags
);
245 SCM_COERCE_SUBSTR (str
);
247 /* re_nsub doesn't account for the `subexpression' representing the
248 whole regexp, so add 1 to nmatches. */
250 nmatches
= SCM_RGX(rx
)->re_nsub
+ 1;
252 matches
= SCM_MUST_MALLOC_TYPE_NUM (regmatch_t
,nmatches
);
253 status
= regexec (SCM_RGX (rx
), SCM_ROCHARS (str
) + offset
,
259 /* The match vector must include a cell for the string that was matched,
261 mvec
= scm_make_vector (SCM_MAKINUM (nmatches
+ 1), SCM_UNSPECIFIED
);
262 SCM_VELTS(mvec
)[0] = str
;
263 for (i
= 0; i
< nmatches
; ++i
)
264 if (matches
[i
].rm_so
== -1)
265 SCM_VELTS(mvec
)[i
+1] = scm_cons (SCM_MAKINUM (-1), SCM_MAKINUM (-1));
268 = scm_cons(SCM_MAKINUM(matches
[i
].rm_so
+ offset
),
269 SCM_MAKINUM(matches
[i
].rm_eo
+ offset
));
271 scm_must_free ((char *) matches
);
274 if (status
!= 0 && status
!= REG_NOMATCH
)
275 scm_error (scm_regexp_error_key
,
277 scm_regexp_error_msg (status
, SCM_RGX (rx
)),
285 scm_init_regex_posix ()
287 scm_tc16_regex
= scm_make_smob_type_mfpe ("regexp", sizeof (regex_t
),
288 NULL
, free_regex
, NULL
, NULL
);
290 /* Compilation flags. */
291 scm_sysintern ("regexp/basic", scm_long2num (REG_BASIC
));
292 scm_sysintern ("regexp/extended", scm_long2num (REG_EXTENDED
));
293 scm_sysintern ("regexp/icase", scm_long2num (REG_ICASE
));
294 scm_sysintern ("regexp/newline", scm_long2num (REG_NEWLINE
));
296 /* Execution flags. */
297 scm_sysintern ("regexp/notbol", scm_long2num (REG_NOTBOL
));
298 scm_sysintern ("regexp/noteol", scm_long2num (REG_NOTEOL
));
300 #include "regex-posix.x"
302 scm_add_feature ("regex");