Hello! Very new to awk I need to do the following... I have one file looking like this: Probe "AFX_1234_at1" Probe "AFX_554545_at1" Probe "AFX_34342_at2" The I have another file looking like that: Probe_set "AFX_1234_at" Signal "AFX_3336" 125 Probe_set "AFX_554545_at" Signal "AFX_3336" 554 Probe_set "AFX_34342_at" Signal "AFX_3336" 88.2 And I would need to build a file looking like this: Probe "AFX_1234_at1" Signal "AFX_3336" 125 Probe "AFX_554545_at1" Signal "AFX_3336" 554 Probe "AFX_34342_at2" Signal "AFX_3336" 88.2 In other words, I need to have the Probe_set of file 2 replaced by the correponding Probe from file 1, and I need to keep the Signal line. Thanks a lot for your inputs! newtoallthis

A very rough sketch: 1. In your BEGIN block, open and read the first file. Create a dictionary (associative array) by splitting e.g. "AFX_1234_at1" (using substring functions) into "AFX_1234_at" and "1", and put these into an associative array like probe["AFX_1234_at"] = "1". 2. Treat the second file as your main input. /Probe_set/ { print "Probe" $1 probe[$1] } /Signal/ { print } (I haven't tested the above code; you'll have to try it out yourself and fix it.)