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 (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAME
wcsxfrm, wcsxfrm_l — wide-character string transformation
SYNOPSIS
#include <wchar.h>
size_t wcsxfrm(wchar_t *restrict ws1, const wchar_t *restrict ws2,
size_t n);
size_t wcsxfrm_l(wchar_t *restrict ws1, const wchar_t *restrict ws2,
size_t n, locale_t locale);
DESCRIPTION
For wcsxfrm(): The functionality described on this reference page is
aligned with the ISO C standard. Any conflict between the requirements
described here and the ISO C standard is unintentional. This volume of
POSIX.1‐2008 defers to the ISO C standard.
The wcsxfrm() and wcsxfrm_l() functions shall transform the wide-char‐
acter 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, corre‐
sponding to the result of wcscoll() and wcscoll_l() applied to the same
two original wide-character strings, and the same LC_COLLATE category
of the current locale or the locale object locale, respectively. 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() and wcsxfrm_l() functions 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() or wcsxfrm_l(), then check errno.
The behavior is undefined if the locale argument to wcsxfrm_l() is the
special locale object LC_GLOBAL_LOCALE or is not a valid locale object
handle.
RETURN VALUE
The wcsxfrm() and wcsxfrm_l() functions 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() and wcsxfrm_l() functions may set errno, but no
return value is reserved to indicate an error.
ERRORS
These functions may fail if:
EINVAL The wide-character string pointed to by ws2 contains wide-char‐
acter 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 current locale (category LC_COLLATE).
The fact that when n is 0 ws1 is permitted to be a null pointer is use‐
ful to determine the size of the ws1 array prior to making the trans‐
formation.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSOwcscmp(), wcscoll()
The Base Definitions volume of POSIX.1‐2008, <wchar.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 WCSXFRM(3P)
