1 /* Copyright (C) 1997, 1998, 1999, 2000, 2001 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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/smob.h"
56 #include "libguile/symbols.h"
57 #include "libguile/vectors.h"
58 #include "libguile/strports.h"
59 #include "libguile/ports.h"
60 #include "libguile/feature.h"
61 #include "libguile/strings.h"
63 #include "libguile/validate.h"
64 #include "libguile/regex-posix.h"
66 /* This is defined by some regex libraries and omitted by others. */
71 scm_t_bits scm_tc16_regex
;
76 regfree (SCM_RGX (obj
));
77 scm_gc_free (SCM_RGX (obj
), sizeof(regex_t
), "regex");
83 SCM_SYMBOL (scm_regexp_error_key
, "regular-expression-syntax");
86 scm_regexp_error_msg (int regerrno
, regex_t
*rx
)
91 /* FIXME: must we wrap any external calls in SCM_DEFER_INTS...SCM_ALLOW_INTS?
92 Or are these only necessary when a SCM object may be left in an
93 undetermined state (half-formed)? If the latter then I believe we
94 may do without the critical section code. -twp */
96 /* We could simply make errmsg a char pointer, and allocate space with
97 malloc. But since we are about to pass the pointer to scm_error, which
98 never returns, we would never have the opportunity to free it. Creating
99 it as a SCM object means that the system will GC it at some point. */
101 errmsg
= scm_make_string (SCM_MAKINUM (80), SCM_UNDEFINED
);
103 l
= regerror (regerrno
, rx
, SCM_STRING_CHARS (errmsg
), 80);
106 errmsg
= scm_make_string (SCM_MAKINUM (l
), SCM_UNDEFINED
);
107 regerror (regerrno
, rx
, SCM_STRING_CHARS (errmsg
), l
);
110 return SCM_STRING_CHARS (errmsg
);
113 SCM_DEFINE (scm_regexp_p
, "regexp?", 1, 0, 0,
115 "Return @code{#t} if @var{obj} is a compiled regular expression,\n"
116 "or @code{#f} otherwise.")
117 #define FUNC_NAME s_scm_regexp_p
119 return SCM_BOOL(SCM_RGXP (obj
));
123 SCM_DEFINE (scm_make_regexp
, "make-regexp", 1, 0, 1,
124 (SCM pat
, SCM flags
),
125 "Compile the regular expression described by @var{pat}, and\n"
126 "return the compiled regexp structure. If @var{pat} does not\n"
127 "describe a legal regular expression, @code{make-regexp} throws\n"
128 "a @code{regular-expression-syntax} error.\n"
130 "The @var{flags} arguments change the behavior of the compiled\n"
131 "regular expression. The following flags may be supplied:\n"
134 "@item regexp/icase\n"
135 "Consider uppercase and lowercase letters to be the same when\n"
137 "@item regexp/newline\n"
138 "If a newline appears in the target string, then permit the\n"
139 "@samp{^} and @samp{$} operators to match immediately after or\n"
140 "immediately before the newline, respectively. Also, the\n"
141 "@samp{.} and @samp{[^...]} operators will never match a newline\n"
142 "character. The intent of this flag is to treat the target\n"
143 "string as a buffer containing many lines of text, and the\n"
144 "regular expression as a pattern that may match a single one of\n"
146 "@item regexp/basic\n"
147 "Compile a basic (``obsolete'') regexp instead of the extended\n"
148 "(``modern'') regexps that are the default. Basic regexps do\n"
149 "not consider @samp{|}, @samp{+} or @samp{?} to be special\n"
150 "characters, and require the @samp{@{...@}} and @samp{(...)}\n"
151 "metacharacters to be backslash-escaped (@pxref{Backslash\n"
152 "Escapes}). There are several other differences between basic\n"
153 "and extended regular expressions, but these are the most\n"
155 "@item regexp/extended\n"
156 "Compile an extended regular expression rather than a basic\n"
157 "regexp. This is the default behavior; this flag will not\n"
158 "usually be needed. If a call to @code{make-regexp} includes\n"
159 "both @code{regexp/basic} and @code{regexp/extended} flags, the\n"
160 "one which comes last will override the earlier one.\n"
162 #define FUNC_NAME s_scm_make_regexp
168 SCM_VALIDATE_STRING (1, pat
);
169 SCM_VALIDATE_REST_ARGUMENT (flags
);
171 /* Examine list of regexp flags. If REG_BASIC is supplied, then
172 turn off REG_EXTENDED flag (on by default). */
173 cflags
= REG_EXTENDED
;
175 while (!SCM_NULLP (flag
))
177 if (SCM_INUM (SCM_CAR (flag
)) == REG_BASIC
)
178 cflags
&= ~REG_EXTENDED
;
180 cflags
|= SCM_INUM (SCM_CAR (flag
));
181 flag
= SCM_CDR (flag
);
184 rx
= scm_gc_malloc (sizeof(regex_t
), "regex");
185 status
= regcomp (rx
, SCM_STRING_CHARS (pat
),
186 /* Make sure they're not passing REG_NOSUB;
187 regexp-exec assumes we're getting match data. */
188 cflags
& ~REG_NOSUB
);
191 scm_error (scm_regexp_error_key
,
193 scm_regexp_error_msg (status
, rx
),
198 SCM_RETURN_NEWSMOB (scm_tc16_regex
, rx
);
202 SCM_DEFINE (scm_regexp_exec
, "regexp-exec", 2, 2, 0,
203 (SCM rx
, SCM str
, SCM start
, SCM flags
),
204 "Match the compiled regular expression @var{rx} against\n"
205 "@code{str}. If the optional integer @var{start} argument is\n"
206 "provided, begin matching from that position in the string.\n"
207 "Return a match structure describing the results of the match,\n"
208 "or @code{#f} if no match could be found.\n"
210 "The @var{flags} arguments change the matching behavior.\n"
211 "The following flags may be supplied:\n"
214 "@item regexp/notbol\n"
215 "Operator @samp{^} always fails (unless @code{regexp/newline}\n"
216 "is used). Use this when the beginning of the string should\n"
217 "not be considered the beginning of a line.\n"
218 "@item regexp/noteol\n"
219 "Operator @samp{$} always fails (unless @code{regexp/newline}\n"
220 "is used). Use this when the end of the string should not be\n"
221 "considered the end of a line.\n"
223 #define FUNC_NAME s_scm_regexp_exec
225 int status
, nmatches
, offset
;
227 SCM mvec
= SCM_BOOL_F
;
229 SCM_VALIDATE_RGXP (1, rx
);
230 SCM_VALIDATE_STRING (2, str
);
231 SCM_VALIDATE_INUM_DEF_COPY (3, start
,0, offset
);
232 SCM_ASSERT_RANGE (3, start
, offset
>= 0 && offset
<= SCM_STRING_LENGTH (str
));
233 if (SCM_UNBNDP (flags
))
235 SCM_VALIDATE_INUM (4, flags
);
237 /* re_nsub doesn't account for the `subexpression' representing the
238 whole regexp, so add 1 to nmatches. */
240 nmatches
= SCM_RGX(rx
)->re_nsub
+ 1;
242 matches
= scm_malloc (sizeof (regmatch_t
) * nmatches
);
243 status
= regexec (SCM_RGX (rx
), SCM_STRING_CHARS (str
) + offset
,
249 /* The match vector must include a cell for the string that was matched,
251 mvec
= scm_c_make_vector (nmatches
+ 1, SCM_UNSPECIFIED
);
252 SCM_VECTOR_SET(mvec
,0, str
);
253 for (i
= 0; i
< nmatches
; ++i
)
254 if (matches
[i
].rm_so
== -1)
255 SCM_VECTOR_SET(mvec
,i
+1, scm_cons (SCM_MAKINUM (-1), SCM_MAKINUM (-1)));
257 SCM_VECTOR_SET(mvec
,i
+1,scm_cons (scm_long2num (matches
[i
].rm_so
+ offset
),
258 scm_long2num (matches
[i
].rm_eo
+ offset
)));
263 if (status
!= 0 && status
!= REG_NOMATCH
)
264 scm_error (scm_regexp_error_key
,
266 scm_regexp_error_msg (status
, SCM_RGX (rx
)),
274 scm_init_regex_posix ()
276 scm_tc16_regex
= scm_make_smob_type ("regexp", sizeof (regex_t
));
277 scm_set_smob_free (scm_tc16_regex
, regex_free
);
279 /* Compilation flags. */
280 scm_c_define ("regexp/basic", scm_long2num (REG_BASIC
));
281 scm_c_define ("regexp/extended", scm_long2num (REG_EXTENDED
));
282 scm_c_define ("regexp/icase", scm_long2num (REG_ICASE
));
283 scm_c_define ("regexp/newline", scm_long2num (REG_NEWLINE
));
285 /* Execution flags. */
286 scm_c_define ("regexp/notbol", scm_long2num (REG_NOTBOL
));
287 scm_c_define ("regexp/noteol", scm_long2num (REG_NOTEOL
));
289 #include "libguile/regex-posix.x"
291 scm_add_feature ("regex");