This may be a trivial thing, but this simple code seems to behave oddly: sequences = Bio::FlatFile.auto(ARGF) sequences.each do |seq| puts seq.entry_id end Processes all the files I give it but hangs the script after finishing with the last file. Why would this be? The code above is from the BioRuby site. Thanks for any suggestions. -- Remove surname to reply. http://www.bioinf.ceh.ac.uk/lab/