Depends what exactly you mean by a 'blank line'. Assuming that you mean a line that contains only white space characters then you can do something like this:

while (<>) {
  print if /\S/;
}
[download]

And you can do the same thing from the command line

perl -i.bak -n -e "print if /\S/" filename
[download]

--
<http://www.dave.org.uk>

European Perl Conference - Sept 22/24 2000, ICA, London
<http://www.yapc.org/Europe/>