SIMPLE SOLUTIONS

_TOLOWER - reference manual online

Transliterate uppercase characters to lowercase.

Chapter
2013
_TOLOWER(3POSIX)                    POSIX Programmer's Manual                    _TOLOWER(3POSIX)

PROLOG This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
NAME _tolower — transliterate uppercase characters to lowercase
SYNOPSIS #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. The following sections are informative.
EXAMPLES None.
APPLICATION USAGE Applications should use the tolower() function instead of the obsolescent _tolower() func‐ tion.
RATIONALE None.
FUTURE DIRECTIONS The _tolower() function may be removed in a future version.
SEE ALSO tolower(), isupper() The Base Definitions volume of POSIX.1‐2008, Chapter 7, Locale, <ctype.h>
IEEE/The Open Group 2013 _TOLOWER(3POSIX)