Sort::Merge maybe? (Where you need to have the files already sorted, and it merges the contents into one output).. But you'll still need a filehandle for each file.

I'm not sure I understand the "open file handles dynamically" question.. Isn't it always dynamic? If you want to open a list of files, just run in a loop:

foreach my $file (@files)
{
   my $fh;
   open $fh, "<", $file or die "Can't open $file ($!)";
   push @filehandles,  $fh;
}
[download]

C.