common/include/ascii-string.h

   1 /* nbdkit
   2  * Copyright Red Hat
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /* Case insensitive string comparison functions (like strcasecmp,
  34  * strncasecmp) which work correctly in any locale.  They can only be
  35  * used for comparison when one or both strings is 7 bit ASCII.
  36  */
  37
  38 #ifndef NBDKIT_ASCII_STRING_H
  39 #define NBDKIT_ASCII_STRING_H
  40
  41 #include "ascii-ctype.h"
  42
  43 static inline int
  44 ascii_strcasecmp (const char *s1, const char *s2)
  45 {
  46   const unsigned char *us1 = (const unsigned char *)s1;
  47   const unsigned char *us2 = (const unsigned char *)s2;
  48
  49   while (ascii_tolower (*us1) == ascii_tolower (*us2)) {
  50     if (*us1++ == '\0')
  51       return 0;
  52     us2++;
  53   }
  54
  55   return ascii_tolower (*us1) - ascii_tolower (*us2);
  56 }
  57
  58 static inline int
  59 ascii_strncasecmp (const char *s1, const char *s2, size_t n)
  60 {
  61   if (n != 0) {
  62     const unsigned char *us1 = (const unsigned char *)s1;
  63     const unsigned char *us2 = (const unsigned char *)s2;
  64
  65     do {
  66       if (ascii_tolower (*us1) != ascii_tolower (*us2))
  67         return ascii_tolower (*us1) - ascii_tolower (*us2);
  68       if (*us1++ == '\0')
  69         break;
  70       us2++;
  71     } while (--n != 0);
  72   }
  73
  74   return 0;
  75 }
  76
  77 #endif /* NBDKIT_ASCII_STRING_H */