WCTRANS(3POSIX)

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
wctrans, wctrans_l — define character mapping

SYNOPSIS

#include <wctype.h>

wctrans_t wctrans(const char *charclass);
wctrans_t wctrans_l(const char *charclass, locale_t locale);

DESCRIPTION
For wctrans(): 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.1-2017 defers to the ISO C standard.

The wctrans() and wctrans_l() functions are defined for valid character mapping names identified in the current locale. The charclass is a string identifying a generic character mapping name for which codeset-specific information is required. The following character mapping names are defined in all locales: tolower and toupper.

These functions shall return a value of type wctrans_t, which can be used as the second argument to subsequent calls of towctrans() and towctrans_l().

The wctrans() and wctrans_l() functions shall determine values of wctrans_t according to the rules of the coded character set defined by character mapping information in the current locale or in the locale represented by locale, respectively (category LC_CTYPE).

The values returned by wctrans() shall be valid until a call to setlocale() that modifies the category LC_CTYPE.

The values returned by wctrans_l() shall be valid only in calls to towctrans_l() with a locale represented by locale with the same LC_CTYPE category value.

The behavior is undefined if the locale argument to wctrans_l() is the special locale object LC_GLOBAL_LOCALE or is not a valid locale object handle.

RETURN VALUE
The wctrans() and wctrans_l() functions shall return 0 and may set errno to indicate the error if the given character mapping name is not valid for the current locale (category LC_CTYPE); otherwise, they shall return a non-zero object of type wctrans_t that can be used in calls to towctrans() and towctrans_l().

ERRORS
These functions may fail if:

EINVAL
    The character mapping name pointed to by charclass is not valid in the current locale.

The following sections are informative.

EXAMPLES
None.

APPLICATION USAGE
None.

RATIONALE
None.

FUTURE DIRECTIONS
None.

SEE ALSO
towctrans()

The Base Definitions volume of POSIX.1-2017, <wctype.h>

COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

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.kernel.org/doc/man-pages/reporting_bugs.html .