NAME

wctrans, wctrans_l - define character mapping

SYNOPSIS

#include <wctype.h>

wctrans_t wctrans(const char *charclass);


[CX] wctrans_t wctrans_l(const char *charclass, locale_t locale);

DESCRIPTION

For wctrans(): ^[CX]  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() ^[CX]  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() ^[CX]  and towctrans_l().

The wctrans() ^[CX]  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 ^[CX]  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.

^[CX] 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() ^[CX]  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() ^[CX]  and towctrans_l().

ERRORS

These functions may fail if:

[EINVAL]

^[CX] The character mapping name pointed to by charclass is not valid in the current locale.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

towctrans

XBD <wctype.h>

CHANGE HISTORY

First released in Issue 5. Derived from ISO/IEC 9899:1990/Amendment 1:1995 (E).

Issue 7

The wctrans_l() function is added from The Open Group Technical Standard, 2006, Extended API Set Part 4.

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0732 [302], XSH/TC1-2008/0733 [289], XSH/TC1-2008/0734 [283], and XSH/TC1-2008/0735 [283] are applied.