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

57 lines
1.3 KiB
C

/*
FUNCTION
<<wcsncasecmp_l>>---case-insensitive wide character string compare
INDEX
wcsncasecmp_l
SYNOPSIS
#include <wchar.h>
int wcsncasecmp_l(const wchar_t *<[a]>, const wchar_t * <[b]>,
size_t <[length]>, locale_t <[locale]>);
DESCRIPTION
<<wcsncasecmp_l>> compares up to <[length]> wide characters
from the string at <[a]> to the string at <[b]> in a
case-insensitive manner.
if <[locale]> is LC_GLOBAL_LOCALE or not a valid locale object, the
behaviour is undefined.
RETURNS
If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
both are converted to uppercase), <<wcsncasecmp_l>> returns a
number greater than zero. If the two strings are equivalent,
<<wcsncasecmp_l>> returns zero. If <<*<[a]>>> sorts
lexicographically before <<*<[b]>>>, <<wcsncasecmp_l>> returns a
number less than zero.
PORTABILITY
POSIX-1.2008
<<wcsncasecmp_l>> requires no supporting OS subroutines. It uses
tolower() from elsewhere in this library.
QUICKREF
wcsncasecmp_l
*/
#include <wchar.h>
#include <wctype.h>
int
wcsncasecmp_l (const wchar_t *s1, const wchar_t *s2, size_t n,
struct __locale_t *locale)
{
int d = 0;
for ( ; n != 0; n--)
{
const int c1 = towlower_l (*s1++, locale);
const int c2 = towlower_l (*s2++, locale);
if (((d = c1 - c2) != 0) || (c2 == '\0'))
break;
}
return d;
}