./flipflop
Useless use of tell in void context at ./flipflop line 14.
perl -v 
This is perl, version 5.005_03 built for sun4-solaris

...after the above edit....

root@tivpre-master:/home/robinp # ./fixedflop
flipflipflipflop


##</code><code>##

sub logit {
    local $.=1;
    my $line  = shift @_;
    $line =~ s/\0//g;
    return unless (/\S/..0);
    print $line
}