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pcre

    1: /*************************************************
    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:            Copyright (c) 1997-2008 University of Cambridge
   10: 
   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: #  ifdef HAVE_CONFIG_H
   49: #  include "config.h"
   50: #  endif
   51: #  include "pcre_internal.h"
   52: #endif
   53: 
   54: 
   55: /*************************************************
   56: *           Create PCRE character tables         *
   57: *************************************************/
   58: 
   59: /* This function builds a set of character tables for use by PCRE and returns
   60: a pointer to them. They are build using the ctype functions, and consequently
   61: their contents will depend upon the current locale setting. When compiled as
   62: part of the library, the store is obtained via pcre_malloc(), but when compiled
   63: inside dftables, use malloc().
   64: 
   65: Arguments:   none
   66: Returns:     pointer to the contiguous block of data
   67: */
   68: 
   69: const unsigned char *
   70: pcre_maketables(void)
   71: {
   72: unsigned char *yield, *p;
   73: int i;
   74: 
   75: #ifndef DFTABLES
   76: yield = (unsigned char*)(pcre_malloc)(tables_length);
   77: #else
   78: yield = (unsigned char*)malloc(tables_length);
   79: #endif
   80: 
   81: if (yield == NULL) return NULL;
   82: p = yield;
   83: 
   84: /* First comes the lower casing table */
   85: 
   86: for (i = 0; i < 256; i++) *p++ = tolower(i);
   87: 
   88: /* Next the case-flipping table */
   89: 
   90: for (i = 0; i < 256; i++) *p++ = islower(i)? toupper(i) : tolower(i);
   91: 
   92: /* Then the character class tables. Don't try to be clever and save effort on
   93: exclusive ones - in some locales things may be different. Note that the table
   94: for "space" includes everything "isspace" gives, including VT in the default
   95: locale. This makes it work for the POSIX class [:space:]. Note also that it is
   96: possible for a character to be alnum or alpha without being lower or upper,
   97: such as "male and female ordinals" (\xAA and \xBA) in the fr_FR locale (at
   98: least under Debian Linux's locales as of 12/2005). So we must test for alnum
   99: specially. */
  100: 
  101: memset(p, 0, cbit_length);
  102: for (i = 0; i < 256; i++)
  103:   {
  104:   if (isdigit(i)) p[cbit_digit  + i/8] |= 1 << (i&7);
  105:   if (isupper(i)) p[cbit_upper  + i/8] |= 1 << (i&7);
  106:   if (islower(i)) p[cbit_lower  + i/8] |= 1 << (i&7);
  107:   if (isalnum(i)) p[cbit_word   + i/8] |= 1 << (i&7);
  108:   if (i == '_')   p[cbit_word   + i/8] |= 1 << (i&7);
  109:   if (isspace(i)) p[cbit_space  + i/8] |= 1 << (i&7);
  110:   if (isxdigit(i))p[cbit_xdigit + i/8] |= 1 << (i&7);
  111:   if (isgraph(i)) p[cbit_graph  + i/8] |= 1 << (i&7);
  112:   if (isprint(i)) p[cbit_print  + i/8] |= 1 << (i&7);
  113:   if (ispunct(i)) p[cbit_punct  + i/8] |= 1 << (i&7);
  114:   if (iscntrl(i)) p[cbit_cntrl  + i/8] |= 1 << (i&7);
  115:   }
  116: p += cbit_length;
  117: 
  118: /* Finally, the character type table. In this, we exclude VT from the white
  119: space chars, because Perl doesn't recognize it as such for \s and for comments
  120: within regexes. */
  121: 
  122: for (i = 0; i < 256; i++)
  123:   {
  124:   int x = 0;
  125:   if (i != 0x0b && isspace(i)) x += ctype_space;
  126:   if (isalpha(i)) x += ctype_letter;
  127:   if (isdigit(i)) x += ctype_digit;
  128:   if (isxdigit(i)) x += ctype_xdigit;
  129:   if (isalnum(i) || i == '_') x += ctype_word;
  130: 
  131:   /* Note: strchr includes the terminating zero in the characters it considers.
  132:   In this instance, that is ok because we want binary zero to be flagged as a
  133:   meta-character, which in this sense is any character that terminates a run
  134:   of data characters. */
  135: 
  136:   if (strchr("\\*+?{^.$|()[", i) != 0) x += ctype_meta;
  137:   *p++ = x;
  138:   }
  139: 
  140: return yield;
  141: }
  142: 
  143: /* End of pcre_maketables.c */