http://www.perlmonks.org?node_id=1064472


in reply to merge sequences with new sequence insertion

Perhaps the following will be helpful:

perl -ne 'chomp; $x=0; print if /^(?<!>)\S+$/' input_file.txt >output_ +file.txt

Output on your dataset:

tttgctcggaggggatcgaaaacacttccttattatacaggtaaaccgtatttggataaagctcggaggg +gatcccct

Edit: Sorry... Didn't notice the "insert" spec.