NAME
isalnum —
alphanumeric character test
LIBRARY
library “libc”
SYNOPSIS
#include
<ctype.h>
int
isalnum(int
c);
DESCRIPTION
Theisalnum()
function tests for any character for which
isalpha(3) or
isdigit(3) is true.
RETURN VALUES
The isalnum() function returns zero if the
character tests false and returns non-zero if the character tests true.
SEE ALSO
ctype(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isdigit(3), isgraph(3), islower(3), isprint(3), ispunct(3), isspace(3), isupper(3), isxdigit(3), stdio(3), toascii(3), tolower(3), toupper(3), ascii(7)
STANDARDS
The isalnum() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
CAVEATS
The argument to isalnum() must be
EOF or representable as an unsigned
char; otherwise, the behavior is undefined. See the
CAVEATS section of
ctype(3) for more details.