code/trunk/get.c

/*************************************************
*      Perl-Compatible Regular Expressions       *
*************************************************/

/*
This is a library of functions to support regular expressions whose syntax
and semantics are as close as possible to those of the Perl 5 language. See
the file Tech.Notes for some information on the internals.

Written by: Philip Hazel <ph10@cam.ac.uk>

           Copyright (c) 1997-2001 University of Cambridge

-----------------------------------------------------------------------------
Permission is granted to anyone to use this software for any purpose on any
computer system, and to redistribute it freely, subject to the following
restrictions:

1. This software is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

2. The origin of this software must not be misrepresented, either by
   explicit claim or by omission.

3. Altered versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

4. If PCRE is embedded in any software that is released under the GNU
   General Purpose Licence (GPL), then the terms of that licence shall
   supersede any condition above with which it is incompatible.
-----------------------------------------------------------------------------
*/

/* This module contains some convenience functions for extracting substrings
from the subject string after a regex match has succeeded. The original idea
for these functions came from Scott Wimer <scottw@cgibuilder.com>. */


/* Include the internals header, which itself includes Standard C headers plus
the external pcre header. */

#include "internal.h"


/*************************************************
*      Copy captured string to given buffer      *
*************************************************/

/* This function copies a single captured substring into a given buffer.
Note that we use memcpy() rather than strncpy() in case there are binary zeros
in the string.

Arguments:
  subject        the subject string that was matched
  ovector        pointer to the offsets table
  stringcount    the number of substrings that were captured
                   (i.e. the yield of the pcre_exec call, unless
                   that was zero, in which case it should be 1/3
                   of the offset table size)
  stringnumber   the number of the required substring
  buffer         where to put the substring
  size           the size of the buffer

Returns:         if successful:
                   the length of the copied string, not including the zero
                   that is put on the end; can be zero
                 if not successful:
                   PCRE_ERROR_NOMEMORY (-6) buffer too small
                   PCRE_ERROR_NOSUBSTRING (-7) no such captured substring
*/

int
pcre_copy_substring(const char *subject, int *ovector, int stringcount,
  int stringnumber, char *buffer, int size)
{
int yield;
if (stringnumber < 0 || stringnumber >= stringcount)
  return PCRE_ERROR_NOSUBSTRING;
stringnumber *= 2;
yield = ovector[stringnumber+1] - ovector[stringnumber];
if (size < yield + 1) return PCRE_ERROR_NOMEMORY;
memcpy(buffer, subject + ovector[stringnumber], yield);
buffer[yield] = 0;
return yield;
}


/*************************************************
*      Copy all captured strings to new store    *
*************************************************/

/* This function gets one chunk of store and builds a list of pointers and all
of the captured substrings in it. A NULL pointer is put on the end of the list.

Arguments:
  subject        the subject string that was matched
  ovector        pointer to the offsets table
  stringcount    the number of substrings that were captured
                   (i.e. the yield of the pcre_exec call, unless
                   that was zero, in which case it should be 1/3
                   of the offset table size)
  listptr        set to point to the list of pointers

Returns:         if successful: 0
                 if not successful:
                   PCRE_ERROR_NOMEMORY (-6) failed to get store
*/

int
pcre_get_substring_list(const char *subject, int *ovector, int stringcount,
  const char ***listptr)
{
int i;
int size = sizeof(char *);
int double_count = stringcount * 2;
char **stringlist;
char *p;

for (i = 0; i < double_count; i += 2)
  size += sizeof(char *) + ovector[i+1] - ovector[i] + 1;

stringlist = (char **)(pcre_malloc)(size);
if (stringlist == NULL) return PCRE_ERROR_NOMEMORY;

*listptr = (const char **)stringlist;
p = (char *)(stringlist + stringcount + 1);

for (i = 0; i < double_count; i += 2)
  {
  int len = ovector[i+1] - ovector[i];
  memcpy(p, subject + ovector[i], len);
  *stringlist++ = p;
  p += len;
  *p++ = 0;
  }

*stringlist = NULL;
return 0;
}


/*************************************************
*   Free store obtained by get_substring_list    *
*************************************************/

/* This function exists for the benefit of people calling PCRE from non-C
programs that can call its functions, but not free() or (pcre_free)() directly.

Argument:   the result of a previous pcre_get_substring_list()
Returns:    nothing
*/

void
pcre_free_substring_list(const char **pointer)
{
(pcre_free)((void *)pointer);
}


/*************************************************
*      Copy captured string to new store         *
*************************************************/

/* This function copies a single captured substring into a piece of new
store

Arguments:
  subject        the subject string that was matched
  ovector        pointer to the offsets table
  stringcount    the number of substrings that were captured
                   (i.e. the yield of the pcre_exec call, unless
                   that was zero, in which case it should be 1/3
                   of the offset table size)
  stringnumber   the number of the required substring
  stringptr      where to put a pointer to the substring

Returns:         if successful:
                   the length of the string, not including the zero that
                   is put on the end; can be zero
                 if not successful:
                   PCRE_ERROR_NOMEMORY (-6) failed to get store
                   PCRE_ERROR_NOSUBSTRING (-7) substring not present
*/

int
pcre_get_substring(const char *subject, int *ovector, int stringcount,
  int stringnumber, const char **stringptr)
{
int yield;
char *substring;
if (stringnumber < 0 || stringnumber >= stringcount)
  return PCRE_ERROR_NOSUBSTRING;
stringnumber *= 2;
yield = ovector[stringnumber+1] - ovector[stringnumber];
substring = (char *)(pcre_malloc)(yield + 1);
if (substring == NULL) return PCRE_ERROR_NOMEMORY;
memcpy(substring, subject + ovector[stringnumber], yield);
substring[yield] = 0;
*stringptr = substring;
return yield;
}


/*************************************************
*       Free store obtained by get_substring     *
*************************************************/

/* This function exists for the benefit of people calling PCRE from non-C
programs that can call its functions, but not free() or (pcre_free)() directly.

Argument:   the result of a previous pcre_get_substring()
Returns:    nothing
*/

void
pcre_free_substring(const char *pointer)
{
(pcre_free)((void *)pointer);
}

/* End of get.c */
1	/*************************************************
2	* Perl-Compatible Regular Expressions *
3	*************************************************/
4
5	/*
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.
9
10	Written by: Philip Hazel <ph10@cam.ac.uk>
11
12	Copyright (c) 1997-2001 University of Cambridge
13
14	-----------------------------------------------------------------------------
15	Permission is granted to anyone to use this software for any purpose on any
16	computer system, and to redistribute it freely, subject to the following
17	restrictions:
18
19	1. This software is distributed in the hope that it will be useful,
20	but WITHOUT ANY WARRANTY; without even the implied warranty of
21	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22
23	2. The origin of this software must not be misrepresented, either by
24	explicit claim or by omission.
25
26	3. Altered versions must be plainly marked as such, and must not be
27	misrepresented as being the original software.
28
29	4. If PCRE is embedded in any software that is released under the GNU
30	General Purpose Licence (GPL), then the terms of that licence shall
31	supersede any condition above with which it is incompatible.
32	-----------------------------------------------------------------------------
33	*/
34
35	/* This module contains some convenience functions for extracting substrings
36	from the subject string after a regex match has succeeded. The original idea
37	for these functions came from Scott Wimer <scottw@cgibuilder.com>. */
38
39
40	/* Include the internals header, which itself includes Standard C headers plus
41	the external pcre header. */
42
43	#include "internal.h"
44
45
46
47	/*************************************************
48	* Copy captured string to given buffer *
49	*************************************************/
50
51	/* This function copies a single captured substring into a given buffer.
52	Note that we use memcpy() rather than strncpy() in case there are binary zeros
53	in the string.
54
55	Arguments:
56	subject the subject string that was matched
57	ovector pointer to the offsets table
58	stringcount the number of substrings that were captured
59	(i.e. the yield of the pcre_exec call, unless
60	that was zero, in which case it should be 1/3
61	of the offset table size)
62	stringnumber the number of the required substring
63	buffer where to put the substring
64	size the size of the buffer
65
66	Returns: if successful:
67	the length of the copied string, not including the zero
68	that is put on the end; can be zero
69	if not successful:
70	PCRE_ERROR_NOMEMORY (-6) buffer too small
71	PCRE_ERROR_NOSUBSTRING (-7) no such captured substring
72	*/
73
74	int
75	pcre_copy_substring(const char subject, int ovector, int stringcount,
76	int stringnumber, char *buffer, int size)
77	{
78	int yield;
79	if (stringnumber < 0 \|\| stringnumber >= stringcount)
80	return PCRE_ERROR_NOSUBSTRING;
81	stringnumber *= 2;
82	yield = ovector[stringnumber+1] - ovector[stringnumber];
83	if (size < yield + 1) return PCRE_ERROR_NOMEMORY;
84	memcpy(buffer, subject + ovector[stringnumber], yield);
85	buffer[yield] = 0;
86	return yield;
87	}
88
89
90
91	/*************************************************
92	* Copy all captured strings to new store *
93	*************************************************/
94
95	/* This function gets one chunk of store and builds a list of pointers and all
96	of the captured substrings in it. A NULL pointer is put on the end of the list.
97
98	Arguments:
99	subject the subject string that was matched
100	ovector pointer to the offsets table
101	stringcount the number of substrings that were captured
102	(i.e. the yield of the pcre_exec call, unless
103	that was zero, in which case it should be 1/3
104	of the offset table size)
105	listptr set to point to the list of pointers
106
107	Returns: if successful: 0
108	if not successful:
109	PCRE_ERROR_NOMEMORY (-6) failed to get store
110	*/
111
112	int
113	pcre_get_substring_list(const char subject, int ovector, int stringcount,
114	const char ***listptr)
115	{
116	int i;
117	int size = sizeof(char *);
118	int double_count = stringcount * 2;
119	char **stringlist;
120	char *p;
121
122	for (i = 0; i < double_count; i += 2)
123	size += sizeof(char *) + ovector[i+1] - ovector[i] + 1;
124
125	stringlist = (char **)(pcre_malloc)(size);
126	if (stringlist == NULL) return PCRE_ERROR_NOMEMORY;
127
128	listptr = (const char *)stringlist;
129	p = (char *)(stringlist + stringcount + 1);
130
131	for (i = 0; i < double_count; i += 2)
132	{
133	int len = ovector[i+1] - ovector[i];
134	memcpy(p, subject + ovector[i], len);
135	*stringlist++ = p;
136	p += len;
137	*p++ = 0;
138	}
139
140	*stringlist = NULL;
141	return 0;
142	}
143
144
145
146	/*************************************************
147	* Free store obtained by get_substring_list *
148	*************************************************/
149
150	/* This function exists for the benefit of people calling PCRE from non-C
151	programs that can call its functions, but not free() or (pcre_free)() directly.
152
153	Argument: the result of a previous pcre_get_substring_list()
154	Returns: nothing
155	*/
156
157	void
158	pcre_free_substring_list(const char **pointer)
159	{
160	(pcre_free)((void *)pointer);
161	}
162
163
164
165	/*************************************************
166	* Copy captured string to new store *
167	*************************************************/
168
169	/* This function copies a single captured substring into a piece of new
170	store
171
172	Arguments:
173	subject the subject string that was matched
174	ovector pointer to the offsets table
175	stringcount the number of substrings that were captured
176	(i.e. the yield of the pcre_exec call, unless
177	that was zero, in which case it should be 1/3
178	of the offset table size)
179	stringnumber the number of the required substring
180	stringptr where to put a pointer to the substring
181
182	Returns: if successful:
183	the length of the string, not including the zero that
184	is put on the end; can be zero
185	if not successful:
186	PCRE_ERROR_NOMEMORY (-6) failed to get store
187	PCRE_ERROR_NOSUBSTRING (-7) substring not present
188	*/
189
190	int
191	pcre_get_substring(const char subject, int ovector, int stringcount,
192	int stringnumber, const char **stringptr)
193	{
194	int yield;
195	char *substring;
196	if (stringnumber < 0 \|\| stringnumber >= stringcount)
197	return PCRE_ERROR_NOSUBSTRING;
198	stringnumber *= 2;
199	yield = ovector[stringnumber+1] - ovector[stringnumber];
200	substring = (char *)(pcre_malloc)(yield + 1);
201	if (substring == NULL) return PCRE_ERROR_NOMEMORY;
202	memcpy(substring, subject + ovector[stringnumber], yield);
203	substring[yield] = 0;
204	*stringptr = substring;
205	return yield;
206	}
207
208
209
210	/*************************************************
211	* Free store obtained by get_substring *
212	*************************************************/
213
214	/* This function exists for the benefit of people calling PCRE from non-C
215	programs that can call its functions, but not free() or (pcre_free)() directly.
216
217	Argument: the result of a previous pcre_get_substring()
218	Returns: nothing
219	*/
220
221	void
222	pcre_free_substring(const char *pointer)
223	{
224	(pcre_free)((void *)pointer);
225	}
226
227	/* End of get.c */