NAME
islower —
lower-case character
test
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <ctype.h>
int
islower(
int
c);
DESCRIPTION
The
islower() function tests for any lower-case letter for
which none of
iscntrl(3),
isdigit(3),
ispunct(3), or
isspace(3) is true. In the
``C'' locale,
islower() returns true only
for the characters defined as lower-case letters.
RETURN VALUES
The
islower() function returns zero if the character tests
false and returns non-zero if the character tests true.
SEE ALSO
ctype(3),
isalnum(3),
isalpha(3),
isascii(3),
isblank(3),
iscntrl(3),
isdigit(3),
isgraph(3),
isprint(3),
ispunct(3),
isspace(3),
isupper(3),
isxdigit(3),
stdio(3),
toascii(3),
tolower(3),
toupper(3),
ascii(7)
STANDARDS
The
islower() function conforms to
ANSI
X3.159-1989 (“ANSI C89”).
CAVEATS
The argument to
islower() must be
EOF
or representable as an
unsigned char; otherwise, the
behavior is undefined. See the
CAVEATS
section of
ctype(3) for more
details.