source: trunk/libs/newlib/src/newlib/libc/string/strncasecmp.c @ 444

/*
FUNCTION
        <<strncasecmp>>---case-insensitive character string compare
        
INDEX
        strncasecmp

SYNOPSIS
        #include <strings.h>
        int strncasecmp(const char *<[a]>, const char * <[b]>, size_t <[length]>);

DESCRIPTION
        <<strncasecmp>> compares up to <[length]> characters
        from the string at <[a]> to the string at <[b]> in a 
        case-insensitive manner.

RETURNS

        If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
        both are converted to lowercase), <<strncasecmp>> returns a
        number greater than zero.  If the two strings are equivalent,
        <<strncasecmp>> returns zero.  If <<*<[a]>>> sorts
        lexicographically before <<*<[b]>>>, <<strncasecmp>> returns a
        number less than zero.

PORTABILITY
<<strncasecmp>> is in the Berkeley Software Distribution.

<<strncasecmp>> requires no supporting OS subroutines. It uses
tolower() from elsewhere in this library.

QUICKREF
        strncasecmp
*/

#include <strings.h>
#include <ctype.h>

int 
strncasecmp (const char *s1,
        const char *s2,
        size_t n)
{
  int d = 0;
  for ( ; n != 0; n--)
    {
      const int c1 = tolower(*s1++);
      const int c2 = tolower(*s2++);
      if (((d = c1 - c2) != 0) || (c2 == '\0'))
        break;
    }
  return d;
}