NAME

isalnum — alphanumeric character test

LIBRARY

Standard C Library (libc, -lc)

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 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.