This is quite the same technique that chaos_cat suggested before, just a bit more inefficient, since 
print  { $file_handles{$date} } "$_\n";

[download]
can be put outside the conditional opening of the file.

In reply to Re^5: How can you check to see if a file handle is already open? by alexm
in thread How can you check to see if a file handle is already open? by agent_smith

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