NAME
islower —
lower-case character test
LIBRARY
library “libc”
SYNOPSIS
#include
<ctype.h>
int
islower(int
c);
DESCRIPTION
Theislower()
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.