NAME
towlower —
transliterate uppercase wide-character code to
lowercase
SYNOPSIS
#include
<wctype.h>
wint_t towlower(wint_t wc);
DESCRIPTION
[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 IEEE Std 1003.1-2001 (“POSIX.1”) defers to the ISO C standard.
The towlower () function has
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
() represents an uppercase wide-character code, and there exists a
corresponding lowercase wide-character code (as defined by character type
information in the program locale 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, towlower ()
shall return the lowercase letter corresponding to the argument passed;
otherwise, it shall return the argument unchanged.
ERRORS
No errors are defined.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
setlocale(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), xbd_chap07(7), <wctype.h>, <wchar.h>
CHANGE HISTORY
First released in Issue 4.
Issue 5
The following change has been made in this issue 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 DESCRIPTION is updated to avoid use of the term "must" for application requirements.
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