G'day dragonchild,

Easy! You can use typeglobs, like this:

if (*package::foo{CODE}) {
    # Function package::foo exists.
} else {
    # Function package::foo does not exist.
}
[download]

Of course, if you want to check if an arbitary function exists, it's not quite as pretty:

my $function = "package::foo";
{
    no strict qw/refs/;   # We're going to use symbolic refs.
    if (*{$function}{CODE}) {
        # Function in $fuction exists.
    } else {
        # Function in $function does not exist.
    }
}
[download]

Hope that you find the above useful.

Cheers,
Paul