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ISLOWER(3) |
Library Functions Manual |
ISLOWER(3) |
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.