NAME
wcsxfrm - wide-character string transformation
SYNOPSIS
#include <wchar.h>
size_t wcsxfrm(wchar_t *restrict ws1, const wchar_t *restrict ws2,
size_t n);
DESCRIPTION
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
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(), then check errno.
RETURN VALUE
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.
ERRORS
The wcsxfrm() function may fail if:
EINVAL The wide-character string pointed to by ws2 contains wide-
character codes outside the domain of the collating sequence.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
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
transformation.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
wcscmp() , wcscoll() , the Base Definitions volume of
IEEE Std 1003.1-2001, <wchar.h>
COPYRIGHT
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 .