I don't think you can do it as you are trying. According to perlvar, most of the $thingy variables for regexes don't count for regexes within a block, which is how I imagine split() treats them.

The <FILE> should make it so that the newline is always and only at the end. (unless you changed $/)Why not:

while(<FILE>){
    for my $myword  (split(/\s+/)){
        #do stuff
    }
    #There's a newline now
}
[download]

Update: BTW, $/ will always equal "\n" unless you change it. It's the value that the <FILE> constructor uses to split on, not what split uses.