use Errno ':POSIX';

{
    no warnings 'redefine', 'once';

    local *CORE::GLOBAL::print = sub {
        $! = ENOSPC;
        return;
    };

    print 'test', $/ or die $!;
}

##</code><code>##

*CORE::GLOBAL::glob = sub {
    my $pat = shift;
    my @got;
    local *D;
    if (opendir D, '.') {
        @got = grep /$pat/, readdir D;
        closedir D;
    }
    return @got;
};

package Whatever;

print <[a-z_]+\.pm>;  #show all pragmas in the current directory