NAME

_tolower - transliterate uppercase characters to lowercase

SYNOPSIS

[OB XSI] #include <ctype.h>

int _tolower(int c);

DESCRIPTION

The _tolower() macro shall be equivalent to tolower(c) except that the application shall ensure that the argument c is an uppercase letter.

RETURN VALUE

Upon successful completion, _tolower() shall return the lowercase letter corresponding to the argument passed.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

Applications should use the tolower() function instead of the obsolescent _tolower() function.

RATIONALE

None.

FUTURE DIRECTIONS

The _tolower() function may be removed in a future version.

SEE ALSO

tolower, isupper

XBD Locale, <ctype.h>

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

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

Issue 7

The _tolower() function is marked obsolescent.