wcscoll() — Language collation string comparison
Standards
| Standards / Extensions | C or C++ | Dependencies |
|---|---|---|
ISO C Amendment
XPG4 XPG4.2 C99 Single UNIX Specification, Version 3 |
both |
Format
#include <wchar.h>
int wcscoll(const wchar_t *wcs1, const wchar_t *wcs2);General description
Compares
the wide-character string pointed to by wcs1 to the
wide-character string pointed to by wcs2, both interpreted
as appropriate to the LC_COLLATE category of the current locale.
Returned value
wcscoll() returns an integer
greater than, equal to, or less than zero, according to whether the
wide string pointed to by wcs1 is greater than, equal
to, or less than the wide-character string pointed to by wcs2,
when both wide-character strings are interpreted as appropriate to
the LC_COLLATE category of the current locale.
wcscoll() differs from wcscmp(). wcscoll() function performs a comparison between two wide character strings based on language collation rules as controlled by the LC_COLLATE category. On the other hand, wcscmp() performs a wide-character code to wide-character code comparison.
wcscoll() indicates error conditions by setting errno; however, there is no returned value to indicate an error. To check for errors, errno should be set to zero, and then checked upon return from wcscoll(). If errno is nonzero, an error has occurred.
The EILSEQ error can be
set to indicate that the wcs1 or wcs2 arguments
contain characters outside the domain of the collating sequence.
Example
/* CELEBW07 */
#include <stdio.h>
#include <wchar.h>
int main(void)
{
int result;
wchar_t *wcs1 = L"first_wide_string";
wchar_t *wcs2 = L"second_wide_string";
result = wcscoll(wcs1, wcs2);
if ( result == 0)
printf("\"%ls\" is identical to \"%ls\"\n", wcs1, wcs2);
else if ( result < 0)
printf("\"%ls\" is less than \"%ls\"\n", wcs1, wcs2);
else
printf("\"%ls\" is greater than \"%ls\"\n", wcs1, wcs2);
}
"first_wide_string" is less than "second_wide_string"