Tutorial on using fc, a UNIX and Linux command for editing and re-executing commands previously entered into an interactive shell. Examples of editing and re-executing the last command, editing and executing a previous command, setting the text editor to be used, listing previous commands and executing a command without editing it.
Tutorial on using cal, a UNIX and Linux command for displaying a calendar in the console. Examples of displaying a single month, multiple months, showing week numbers, Julian dates and arbitrary dates passed as arguments.
Tutorial on using du, a UNIX and Linux command for estimating file space usage. Examples of showing a disk usage summary, outputting a human readable format, showing the size of a directory and showing the ten largest files or folders on a system.