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/*
FUNCTION
	<<strncasecmp>>---case-insensitive character string compare
 
INDEX
	strncasecmp
 
ANSI_SYNOPSIS
	#include <string.h>
	int strncasecmp(const char *<[a]>, const char * <[b]>, size_t <[length]>);
 
TRAD_SYNOPSIS
	#include <string.h>
	int strncasecmp(<[a]>, <[b]>, <[length]>)
	char *<[a]>;
	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 uppercase), <<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 <string.h>
#include <ctype.h>
 
int 
_DEFUN (strncasecmp, (s1, s2, n),
	_CONST char *s1 _AND
	_CONST char *s2 _AND
	size_t n)
{
  if (n == 0)
    return 0;
 
  while (n-- != 0 && tolower(*s1) == tolower(*s2))
    {
      if (n == 0 || *s1 == '\0' || *s2 == '\0')
	break;
      s1++;
      s2++;
    }
 
  return tolower(*(unsigned char *) s1) - tolower(*(unsigned char *) s2);
}