/[pcre]/code/trunk/pcre_maketables.c
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Contents of /code/trunk/pcre_maketables.c

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Revision 91 - (hide annotations) (download)
Sat Feb 24 21:41:34 2007 UTC (7 years, 5 months ago) by nigel
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File size: 5460 byte(s)
Load pcre-6.7 into code/trunk.

1 nigel 77 /*************************************************
2     * Perl-Compatible Regular Expressions *
3     *************************************************/
4    
5     /* PCRE is a library of functions to support regular expressions whose syntax
6     and semantics are as close as possible to those of the Perl 5 language.
7    
8     Written by Philip Hazel
9 nigel 87 Copyright (c) 1997-2006 University of Cambridge
10 nigel 77
11     -----------------------------------------------------------------------------
12     Redistribution and use in source and binary forms, with or without
13     modification, are permitted provided that the following conditions are met:
14    
15     * Redistributions of source code must retain the above copyright notice,
16     this list of conditions and the following disclaimer.
17    
18     * Redistributions in binary form must reproduce the above copyright
19     notice, this list of conditions and the following disclaimer in the
20     documentation and/or other materials provided with the distribution.
21    
22     * Neither the name of the University of Cambridge nor the names of its
23     contributors may be used to endorse or promote products derived from
24     this software without specific prior written permission.
25    
26     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27     AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29     ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30     LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36     POSSIBILITY OF SUCH DAMAGE.
37     -----------------------------------------------------------------------------
38     */
39    
40    
41     /* This module contains the external function pcre_maketables(), which builds
42     character tables for PCRE in the current locale. The file is compiled on its
43     own as part of the PCRE library. However, it is also included in the
44     compilation of dftables.c, in which case the macro DFTABLES is defined. */
45    
46    
47     #ifndef DFTABLES
48     #include "pcre_internal.h"
49     #endif
50    
51    
52     /*************************************************
53     * Create PCRE character tables *
54     *************************************************/
55    
56     /* This function builds a set of character tables for use by PCRE and returns
57     a pointer to them. They are build using the ctype functions, and consequently
58     their contents will depend upon the current locale setting. When compiled as
59     part of the library, the store is obtained via pcre_malloc(), but when compiled
60     inside dftables, use malloc().
61    
62     Arguments: none
63     Returns: pointer to the contiguous block of data
64     */
65    
66     const unsigned char *
67     pcre_maketables(void)
68     {
69     unsigned char *yield, *p;
70     int i;
71    
72     #ifndef DFTABLES
73     yield = (unsigned char*)(pcre_malloc)(tables_length);
74     #else
75     yield = (unsigned char*)malloc(tables_length);
76     #endif
77    
78     if (yield == NULL) return NULL;
79     p = yield;
80    
81     /* First comes the lower casing table */
82    
83     for (i = 0; i < 256; i++) *p++ = tolower(i);
84    
85     /* Next the case-flipping table */
86    
87     for (i = 0; i < 256; i++) *p++ = islower(i)? toupper(i) : tolower(i);
88    
89 nigel 87 /* Then the character class tables. Don't try to be clever and save effort on
90     exclusive ones - in some locales things may be different. Note that the table
91     for "space" includes everything "isspace" gives, including VT in the default
92     locale. This makes it work for the POSIX class [:space:]. Note also that it is
93     possible for a character to be alnum or alpha without being lower or upper,
94     such as "male and female ordinals" (\xAA and \xBA) in the fr_FR locale (at
95     least under Debian Linux's locales as of 12/2005). So we must test for alnum
96     specially. */
97 nigel 77
98     memset(p, 0, cbit_length);
99     for (i = 0; i < 256; i++)
100     {
101 nigel 87 if (isdigit(i)) p[cbit_digit + i/8] |= 1 << (i&7);
102     if (isupper(i)) p[cbit_upper + i/8] |= 1 << (i&7);
103     if (islower(i)) p[cbit_lower + i/8] |= 1 << (i&7);
104     if (isalnum(i)) p[cbit_word + i/8] |= 1 << (i&7);
105 nigel 77 if (i == '_') p[cbit_word + i/8] |= 1 << (i&7);
106     if (isspace(i)) p[cbit_space + i/8] |= 1 << (i&7);
107     if (isxdigit(i))p[cbit_xdigit + i/8] |= 1 << (i&7);
108     if (isgraph(i)) p[cbit_graph + i/8] |= 1 << (i&7);
109     if (isprint(i)) p[cbit_print + i/8] |= 1 << (i&7);
110     if (ispunct(i)) p[cbit_punct + i/8] |= 1 << (i&7);
111     if (iscntrl(i)) p[cbit_cntrl + i/8] |= 1 << (i&7);
112     }
113     p += cbit_length;
114    
115     /* Finally, the character type table. In this, we exclude VT from the white
116     space chars, because Perl doesn't recognize it as such for \s and for comments
117     within regexes. */
118    
119     for (i = 0; i < 256; i++)
120     {
121     int x = 0;
122     if (i != 0x0b && isspace(i)) x += ctype_space;
123     if (isalpha(i)) x += ctype_letter;
124     if (isdigit(i)) x += ctype_digit;
125     if (isxdigit(i)) x += ctype_xdigit;
126     if (isalnum(i) || i == '_') x += ctype_word;
127    
128     /* Note: strchr includes the terminating zero in the characters it considers.
129     In this instance, that is ok because we want binary zero to be flagged as a
130     meta-character, which in this sense is any character that terminates a run
131     of data characters. */
132    
133 nigel 91 if (strchr("*+?{^.$|()[", i) != 0) x += ctype_meta;
134     *p++ = x;
135     }
136 nigel 77
137     return yield;
138     }
139    
140     /* End of pcre_maketables.c */

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