tolower
—
upper case to lower case letter conversion
Standard C Library (libc, -lc)
#include <ctype.h>
int
tolower
(int
c);
The tolower
() function converts an upper-case letter to
the corresponding lower-case letter.
If the argument is an upper-case letter, the tolower
()
function returns the corresponding lower-case letter if there is one;
otherwise the argument is returned unchanged.
ctype(3),
isalnum(3),
isalpha(3),
isascii(3),
iscntrl(3),
isdigit(3),
isgraph(3),
islower(3),
isprint(3),
ispunct(3),
isspace(3),
isupper(3),
isxdigit(3),
stdio(3),
toascii(3),
toupper(3),
ascii(7)
The tolower
() function conforms to ANSI
X3.159-1989 (“ANSI C89”).
The argument to tolower
() must be
EOF
or representable as an unsigned
char; otherwise, the behavior is undefined. See the
CAVEATS section of
ctype(3) for more details.