The wcsxfrm() function shall 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 shall be such that if
wcscmp() is applied to two transformed wide strings, it shall return a
value greater than, equal to, or less than 0, corresponding to the result of
wcscoll() applied to the same two original wide-character strings. No
more than n wide-character codes shall be 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() function shall not change the setting of errno if
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(), then check errno.
The wcsxfrm() function shall 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 unspecified.
On error, the wcsxfrm() function may set errno, but no return
value is reserved to indicate an error.
The transformation function is such that two transformed wide-character strings
can be ordered by wcscmp() 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
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html