The most common problem is a poorly documented script that is hard to read. Think ahead when you write your sed scripts and you will be glad you did later. Also since time is the great equalizer try to learn a little each day rather than too much at any one time.
It can again as above begin with something that is very basic and expand as you skills improve and you learn to do more with less. There is a great genius in simplicity. Try to make the script as modular as possible as well as think of recycling everything:-)
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