GNU/Linux is designed to be a hands-on operating system. For that reason, most of its configuration files and system logs are written in plain text, making them easy to read from the command line. If you want to alter these files while logged in as the root user, you'll want to use a file editor such as vi, emacs, or nano. But often you won't want to make changes, you'll just want to look quickly to gather information or to see whether the system is operating the way it should.

To help you view information, GNU/Linux includes a number of view commands. For a glimpse into short files, cat might be enough for you. However, for most purposes, you'll want to try more or, preferably, less. If you are especially interested in the start or end of a file, then head or tail might be the tool to use. The basics of all these commands are easy to learn, all the more so because many use similar options, or at least use similar features.

Taking Out the Cat

Its name tells the story of the original purpose of the cat command, which is short for "concatenate." In other words, the command is designed to join files. Although concatenating is still listed in numerous summaries as the main purpose, I suspect that most people use the command today solely for its secondary purpose of reading short files.

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