illumos: manual page: wcsxfrm.3c

WCSXFRM(3C) Standard C Library Functions WCSXFRM(3C)

NAME

wcsxfrm, wsxfrm - wide character string transformation

SYNOPSIS

#include <wchar.h>

size_t wcsxfrm(wchar_t *ws1, const wchar_t *ws2, size_t n);

size_t wsxfrm(wchar_t *ws1, const wchar_t *ws2, size_t n);

DESCRIPTION

The wcsxfrm() and wcsxfrm() functions transform the wide character string
pointed to by ws2 and place the resulting wide character string into the
array pointed to by ws1. The transformation is such that if either the
wcscmp(3C) or wscmp(3C) functions are applied to two transformed wide
strings, they return a value greater than, equal to, or less than 0,
corresponding to the result of the wcscoll(3C) or wscoll(3C) function
applied to the same two original wide character strings. No more than n
wide-character codes are placed into the resulting array pointed to by
ws1, including the terminating null wide-character code. If n is 0, ws1
is permitted to be a null pointer. If copying takes place between objects
that overlap, the behavior is undefined.

The wcsxfrm() and wsxfrm() functions do not change the setting of errno
if successful.

Since no return value is reserved to indicate an error, an application
wishing to check for error situations should set errno to 0, then call
wcsxfrm() or wsxfrm(), then check errno.

RETURN VALUES

The wcsxfrm() and wsxfrm() functions return the length of the transformed
wide character string (not including the terminating null wide-character
code). If the value returned is n or more, the contents of the array
pointed to by ws1 are indeterminate.

On error, wcsxfrm() and wsxfrm() may set errno but no return value is
reserved to indicate an error.

ERRORS

The wcsxfrm() and wsxfrm() functions may fail if:

EINVAL
The wide character string pointed to by ws2 contains wide-
character codes outside the domain of the collating sequence.

USAGE

The transformation function is such that two transformed wide character
strings can be ordered by the wcscmp() or wscmp() functions as
appropriate to collating sequence information in the program's locale
(category LC_COLLATE).

The fact that when n is 0, ws1 is permitted to be a null pointer, is
useful to determine the size of the ws1 array prior to making the
transformation.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

+--------------------+-------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------------+
|CSI | Enabled |
+--------------------+-------------------------+
|Interface Stability | wcsxfrm() is Standard |
+--------------------+-------------------------+
|MT-Level | MT-Safe with exceptions |
+--------------------+-------------------------+

The wcsxfrm() and wsxfrm() functions can be used safely in multithreaded
applications as long as setlocale(3C) is not being called to change the
locale.