usr/src/lib/libast/common/comp/strncasecmp.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 #include <ast.h>
  25
  26 #if _lib_strncasecmp
  27
  28 NoN(strncasecmp)
  29
  30 #else
  31
  32 #include <ctype.h>
  33
  34 #undef  strncasecmp
  35
  36 int
  37 strncasecmp(register const char* a, register const char* b, size_t n)
  38 {
  39         register const char*    e;
  40         register int            ac;
  41         register int            bc;
  42         register int            d;
  43
  44         e = a + n;
  45         for (;;)
  46         {
  47                 if (a >= e)
  48                         return 0;
  49                 ac = *a++;
  50                 if (isupper(ac))
  51                         ac = tolower(ac);
  52                 bc = *b++;
  53                 if (isupper(bc))
  54                         bc = tolower(bc);
  55                 if (d = ac - bc)
  56                         return d;
  57                 if (!ac)
  58                         return 0;
  59         }
  60 }
  61
  62 #endif