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.