NAME
isalnum —
alphanumeric character test
SYNOPSIS
#include
<ctype.h>
int
isalnum(int
c);
DESCRIPTION
The
isalnum()
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 or non-zero if the character tests true.
SEE ALSO
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”).
HISTORY
The isalnum() function first appeared in
Version 7 AT&T UNIX.
CAVEATS
The argument to isalnum() must be
EOF or representable as an unsigned
char; otherwise, the result is undefined.