Enhancing efficiency with history

The versatile Bash history command can save you time and effort at the command line.

If you work in a terminal, you’ve likely used Bash’s history command to save yourself the trouble of retyping a command [1] (Figure 1). However, if you’re like most people, your use of history may have been confined to scrolling through the list of previously used commands. If all you are interested in are the most recently used commands, the arrow keys may be all that you need. However, the history command is capable of doing much more and in an economical way – especially if you have a good memory. You can start by adjusting history‘s environmental variables and then learn how to modify history entries for easier searching and for repurposing them using three types of editing options: event designators, word designators, and modifiers. The flexibility of all these options can be combined so that, with a little memorization, you can make the Bash history work for you to save time with minimal effort.

Environmental Variables

The history commmand has several environmental variables. All are added or modified in .profile or .bashrc in your home directory, depending on the distribution. The size of the history file is limited by HISTSIZE, which sets the number of entries in the history, and/or by HISTFILESIZE, the maximum memory to allot for the history. Both have similar structures:

HISTSIZE=NUMBER
HISTFILESIZE=NUMBER

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