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)
