$ perl5.005_03 -ne '$$_++||print' infile
    here
    comes
    trouble
    Modification of a read-only value attempted at -e line 1, <> chunk 4.


    $ perl5.6.1 -ne '$$_++||print' infile
    here
    comes
    trouble
    Modification of a read-only value attempted at -e line 1, <> chunk 4.

    $ perl5.8.0 -ne '$$_++||print' infile
    here
    comes
    trouble
    1
    2