ISLOWER(3)

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.

April 17, 2008 | NetBSD 7.1