Using age-old UNIX tools like sed is all well and good, but I would personally recommend using Python as a general, everyday-use scripting tool. If you have a CSV, it's really something as simple as:
file_to_open = sys.argv
f = open(file_to_open, 'r')
file_buffer = f.read()
file_buffer = file_buffer.split(',')
In that example, you will be given a list (file_buffer) of all of the values that was previously one, big, comma-separated block o' text.
My other reason for suggesting Python, is that it is super
easy to learn, powerful as all-get-out, and what knowledge you learn in Python (the same could be said for Perl and sed, however) is portable to other systems (Linux, Mac OS X, Windows, etc.)