libc/string/strspn.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2008  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19
  20 #include <string.h>
  21
  22 size_t strspn (char const *s, char const *accept)
  23 {
  24         const char *p;
  25         const char *a;
  26         size_t count = 0;
  27
  28         for (p = s; *p != '\0'; ++ p) {
  29                 for (a = accept; *a != '\0'; ++ a) {
  30                         if(*p == *a)
  31                                 break;
  32                 }
  33
  34                 if (*a == '\0')
  35                         return count;
  36
  37                 ++ count;
  38         }
  39
  40         return count;
  41 }