★ Sed Introduction and Tutorial

Perform a Google search for “sed” and the top result will be “Sed – An Introduction and Tutorial“. Bruce Barnett has written an excellent document that will help you quickly get up to speed using sed. It’s a must read for systems administrators who want to learn it.
Sed is short for Stream EDitor. It is an application that allows you to write a script to edit a file and provide a file name to be modified ((More about sed can be found on the Sed FAQ )). It is frequently used for quick global substitutions. Along with sed, awk is another tool that should be in your Unix tool box. Lucky for us, Bruce has also written a a guide to awk. He has written several other tutorials on Unix shell programming which can be found on his site