WCSXFRM(3P)                                         POSIX Programmer's Manual                                        WCSXFRM(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

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  unspeci-
       fied.

       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, Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                   WCSXFRM(3P)