NAME
towlower
towlower_l — transliterate
uppercase wide-character code to lowercase
SYNOPSIS
#include
<wctype.h>
wint_t towlower(wint_t wc); [CX] wint_t towlower_l(wint_t wc, locale_t locale);
DESCRIPTION
For towlower (): [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.1-2008 defers to the ISO C
standard.
The towlower ()
[CX] and towlower_l () 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 current
locale or the value of WEOF. If the argument has any other value, the
behavior is undefined. If the argument of towlower
() [CX] or towlower_l () represents an
uppercase wide-character code, and there exists a corresponding lowercase
wide-character code as defined by character type information in the locale
of the process [CX] or in the locale represented by
locale,
respectively (category
LC_CTYPE
), the result shall be the corresponding lowercase wide-character
code. All other arguments in the domain are returned unchanged.
RETURN VALUE
Upon successful completion, the towlower
() [CX] and towlower_l () functions
shall return the lowercase letter corresponding to the argument passed;
otherwise, they shall return the argument unchanged.
ERRORS
The towlower_l () function may fail if:
- [EINVAL]
- [CX] locale is not a valid locale object handle.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
XBD V1_chap07(7) , <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/AMD1:1995 (“ISO C90, Amendment 1”) (E):
- The SYNOPSIS has been changed to indicate that this function and associated data types are now made visible by inclusion of the <wctype.h> header rather than <wchar.h>.
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.