newlib-cygwin/newlib/libc/string/strncasecmp.c

64 lines
1.5 KiB
C

/*
FUNCTION
<<strncasecmp>>---case-insensitive character string compare
INDEX
strncasecmp
ANSI_SYNOPSIS
#include <strings.h>
int strncasecmp(const char *<[a]>, const char * <[b]>, size_t <[length]>);
TRAD_SYNOPSIS
#include <strings.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 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
_DEFUN (strncasecmp, (s1, s2, n),
_CONST char *s1 _AND
_CONST char *s2 _AND
size_t n)
{
_CONST unsigned char *ucs1 = (_CONST unsigned char *) s1;
_CONST unsigned char *ucs2 = (_CONST unsigned char *) s2;
int d = 0;
for ( ; n != 0; n--)
{
_CONST int c1 = tolower(*ucs1++);
_CONST int c2 = tolower(*ucs2++);
if (((d = c1 - c2) != 0) || (c2 == '\0'))
break;
}
return d;
}