http://www.unix.com – Hi all, I'm looking for a way to merge multiple columns (from one file) into a single column in an output file. The file I have looks somewhat like this: Code: @HWI-ST212 1:N:0 AGTCCTACCGGGAGT + @@@DDDDDHHHHHII @HWI-ST212 1:N:0 CGTTTAAAAATTTCT + @;@B;DDDDH?:F;F @HWI-ST212 1:N:0 TCGGAGATTCCGTAC (HowTos)