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 .