http://www.unix.com – Hi all, i need help to replace certain values in a file. I need the script to check and match the ID and exNum1. if match, values in $3 (file2.txt) need to replace the value for 'START' (file1.txt) for each match. The sample structure is like this:- File1.txt Code: ID P_6 START 235411 END 18763 // ID P_10 START 631012 END 32814 // ID P_133 START 389417 END 314124 // File2.txt Code: ex 21204 22151 P_6 S   (HowTos)