The Open Group Base Specifications Issue 7, 2018 edition
IEEE Std 1003.1-2017 (Revision of IEEE Std 1003.1-2008)
Copyright © 2001-2018 IEEE and The Open Group

NAME

towlower, towlower_l - transliterate uppercase wide-character code to lowercase

SYNOPSIS

#include <wctype.h>

wint_t towlower(wint_t
wc);

[CX] [Option Start] wint_t towlower_l(wint_t wc, locale_t locale); [Option End]

DESCRIPTION

For towlower(): [CX] [Option Start]  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. [Option End]

The towlower() [CX] [Option Start] and towlower_l() [Option End]  functions have as a domain a type wint_t, the value of which the application shall ensure is a character representable as a wchar_t, and a wide-character code corresponding to a valid character in the locale used by the function or the value of WEOF. If the argument has any other value, the behavior is undefined. If the argument of towlower() [CX] [Option Start]  or towlower_l() [Option End] represents an uppercase wide-character code, and there exists a corresponding lowercase wide-character code as defined by character type information in the current locale [CX] [Option Start]  or in the locale represented by locale, [Option End]  respectively (category LC_CTYPE), the result shall be the corresponding lowercase wide-character code. All other arguments in the domain are returned unchanged.

[CX] [Option Start] The behavior is undefined if the locale argument to towlower_l() is the special locale object LC_GLOBAL_LOCALE or is not a valid locale object handle. [Option End]

RETURN VALUE

Upon successful completion, the towlower() [CX] [Option Start]  and towlower_l() [Option End]  functions shall return the lowercase letter corresponding to the argument passed; otherwise, they shall return the argument unchanged.

ERRORS

No errors are defined.


The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

setlocale, uselocale

XBD Locale, <locale.h>, <wctype.h>

CHANGE HISTORY

First released in Issue 4.

Issue 5

The following change has been made in this version for alignment with ISO/IEC 9899:1990/Amendment 1:1995 (E):

Issue 6

The normative text is updated to avoid use of the term "must" for application requirements.

Issue 7

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

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0678 [302], XSH/TC1-2008/0679 [283], and XSH/TC1-2008/0680 [283] are applied.

POSIX.1-2008, Technical Corrigendum 2, XSH/TC2-2008/0373 [685] is applied.

End of informative text.

 

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