You can't do this. When you passed the %new_db to the sub, it got broken apart into a list, which looks like (1, 'gedit', 2, 'ppp'). So when you write $_[1] you are getting the first thing in that list, but you wanted to get the whole thing.

You could fix it by writing @_[1..$#_] to get the whole thing, but that's pretty ugly. You could also write my ($count, %packages) = @_; which is less ugly and does the same thing.

The best thing is to not even break the hash into a list at all. You can do that by passing a reference to the sub. Read about references at http://perldoc.com/perl5.8.0/pod/perlreftut.html