Example: Parsing Log Files

Generally the one-liners that you might find yourself writing fall into two categories: problems that are too simple or too temporary to ever commit to a file, or problems that are exploratory in nature, where you might eventually write a script but aren’t ready to do so just yet.

Let’s look at an example of the latter, a case of exploring a file to gather information about its contents. The file we’ll be looking at is a log file for the popular web server software Apache. Its error logs look something like this:

 
[Tue Dec 30 15:25:20 2014] [error] Directory index forbidden
 
[Tue Dec 30 15:26:11 2014] [notice] caught SIGTERM, shutting down
 
[Tue Dec 30 15:26:14 2014] [notice] Digest: generating secret ...
 
[Tue Dec ...

Get Text Processing with Ruby now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.