It probably won't matter here, but that's a bad idea in general since you open up yourself to a race condition: the file might be created after the -e test but before the open by another process. You need an atomic operation:

if (open FH, "<", $file) {
    # read it and do stuff
    open FH, ">", $file or die "Failed: $! trying to re-open $file\n";
}
else {
    # do stuff
    open FH, ">", $file  or die "Failed: $! trying to create new $file
+\n";
}
[download]

Also, use the three-argument form of open as I've said elsewhere in this thread.

Makeshifts last the longest.