Serious Data Analysis often Requires Shell Scripting

When working with data, you are sooner or later going to face the need for file manipulation and text processing on a large scale. LinuxCommand.org is an excellent online introduction written by William Shotts, Jr. He is also writing a very exciting book on this topic (and on much more). It is called The Linux Command Line and is available for free. The current version can be downloaded in PDF format at SourceForge.net.