TOLOWER(3C) Standard C Library Functions TOLOWER(3C)

NAME

tolower, tolower_l - transliterate upper-case characters to lower-case

SYNOPSIS

#include <ctype.h>

int tolower(int c);

int tolower_l(int c, locale_t loc);

DESCRIPTION

The tolower() function has as a domain of type int, the value of which is
representable as an unsigned char or the value of EOF. If the argument
has any other value, the argument is returned unchanged. If the argument
of tolower() represents an upper-case letter, and there exists a
corresponding lower-case letter (as defined by character type information
in the locale category LC_CTYPE), the result is the corresponding lower-
case letter. All other arguments in the domain are returned unchanged.

The function tolower_l() behaves identically to tolower(), except instead
of operating in the current locale, it operates in the locale specified
by loc.

A macro form, _tolower() exists. It is defined for standards conformance,
particularly with legacy standards. It was deprecated in POSIX 2008
(Issue 7), and its use is discouraged. The macro, on this system, is just
an alias for tolower().

RETURN VALUES

On successful completion, tolower() returns the lower-case letter
corresponding to the argument passed. Otherwise, it returns the argument
unchanged.

ERRORS

No errors are defined.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|CSI | Enabled |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO

newlocale(3C), setlocale(3C), uselocale(3C), attributes(7), standards(7)

October 4, 2015 TOLOWER(3C)