Awk in 20 Minutes
Fred T-H (via Hacker News):
Awk is a tiny programming language and a command line tool. It’s particularly appropriate for log parsing on servers, mostly because Awk will operate on files, usually structured in lines of human-readable text.
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An Awk script is structured simply, as a sequence of patterns and actions[…]Every line of the document to scan will have to go through each of the patterns, one at a time.
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Finally, the last kind of pattern is a bit hard to classify. It’s halfway between variables and special values, and they’re called Fields, which deserve a section of their own.