usr/src/lib/libast/common/comp/re_comp.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #pragma prototyped
  23 /*
  24  * re_comp implementation
  25  */
  26
  27 #include <ast.h>
  28 #include <re_comp.h>
  29 #include <regex.h>
  30
  31 #undef  error
  32 #undef  valid
  33
  34 static struct
  35 {
  36         char    error[64];
  37         regex_t re;
  38         int     valid;
  39 } state;
  40
  41 char*
  42 re_comp(const char* pattern)
  43 {
  44         register int    r;
  45
  46         if (!pattern || !*pattern)
  47         {
  48                 if (state.valid)
  49                         return 0;
  50                 r = REG_BADPAT;
  51         }
  52         else
  53         {
  54                 if (state.valid)
  55                 {
  56                         state.valid = 0;
  57                         regfree(&state.re);
  58                 }
  59                 if (!(r = regcomp(&state.re, pattern, REG_LENIENT|REG_NOSUB|REG_NULL)))
  60                 {
  61                         state.valid = 1;
  62                         return 0;
  63                 }
  64         }
  65         regerror(r, &state.re, state.error, sizeof(state.error));
  66         return state.error;
  67 }
  68
  69 int
  70 re_exec(const char* subject)
  71 {
  72         if (state.valid && subject)
  73                 switch (regexec(&state.re, subject, 0, NiL, 0))
  74                 {
  75                 case 0:
  76                         return 1;
  77                 case REG_NOMATCH:
  78                         return 0;
  79                 }
  80         return -1;
  81 }