#!/usr/bin/perl -w

my $file;

while($file = shift @ARGV) {
  if ($file =~ m!\.gz$!) {
    my $name = $`;
    print "$file...\n";
    `gunzip $file`;
    `cp $name _$name`;
    `bzip2 $name`;
    `mv _$name $name`;
    `gzip --best $name`;
  } else {
    print STDERR "$file does not seems a gzip file\n";
  }
}