http://www.unix.com – I would like help adding a new column to a large txt file (~10MB) that contains the filename. I have searched other posts but have not found an adequate solution. I need this extra column so I can concatenate >100 files and perform awk searches on this large file. My current txt file look like this Code: #chr_name chr_start chr_end ref_base alt_base hom_het snp_quality tot_depth alt_depth region gene change&n (HowTos)