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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(5) for descriptions of the following attributes:
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ATTRIBUTE TYPE |
ATTRIBUTE VALUE |
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CSI |
Enabled |
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Interface Stability |
Standard |
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MT-Level |
MT-Safe |
SEE ALSO
newlocale(3C), setlocale(3C), uselocale(3C), attributes(5), standards(5)