lib/strspn.c

   1 /* Copyright (C) 1991, 1997 Free Software Foundation, Inc.
   2
   3    NOTE: The canonical source of this file is maintained with the GNU
   4    C Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #if HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #if defined _LIBC || HAVE_STRING_H
  25 # include <string.h>
  26 #else
  27 # include <strings.h>
  28 # ifndef strchr
  29 #  define strchr index
  30 # endif
  31 #endif
  32
  33 #undef strspn
  34
  35 /* Return the length of the maximum initial segment
  36    of S which contains only characters in ACCEPT.  */
  37 size_t
  38 strspn (s, accept)
  39      const char *s;
  40      const char *accept;
  41 {
  42   const char *p;
  43   const char *a;
  44   size_t count = 0;
  45
  46   for (p = s; *p != '\0'; ++p)
  47     {
  48       for (a = accept; *a != '\0'; ++a)
  49         if (*p == *a)
  50           break;
  51       if (*a == '\0')
  52         return count;
  53       else
  54         ++count;
  55     }
  56
  57   return count;
  58 }