14.7. Finding Commands Quickly

I was looking at a man page yesterday, but I cannot remember the name of the command I was reading about, and I did not write it down. How do I get the man page back?

The command you used is stored in a file called .bash_history. By default, this file records the last 500 commands you typed at the shell prompt.

You can glimpse the history of your commands by typing history at the shell prompt, but the results are displayed too quickly for you to read every line.

Another way to view .bash_history is with a utility such as less. Type less .bash_history at the shell prompt and the results will display one page at a time. To move forward a screen, press the [Space] bar; to move back a screen, press the [b] key, and to quit, press [q].

Paging through .bash_history to find a command can be tedious. Alternatively, you can search through the file for keywords using grep, a powerful search utility.

Say you were reading the man page the day before, but cannot recall its name. To search for the command, type:

history | grep man

All the commands you typed which have the word man in them are now highlighted.

There are many ways to use your command history. For other tips and tricks, see Section 14.8 Tips on Using Command History.