What The Heck Is That?

What The Heck Is That?

Linux is full of little mysteries just waiting for your discovery. Sometimes those mysteries are uncovered with a full description, as in man or info. Sometimes they reveal themselves in the which command. Maybe best of all are the answers that come in a single concise line.

The whatis command does exactly that. Where man and info present all possible information on a command, and which clues you into whether a program is in the path, whatis returns a simple one-line description of a program. For example:

    whatis ps

returns

    ps (1)    - report process status

Simple and to the point.

As you’ve probably guessed, you can also send the output of the whatis command to other Linux tools. Let’s take a look at the contents of my /bin directory:

    cd /bin; whatis * | more

This is a combination of several commands. [C]hange [d]irectory to /bin, then run whatis on all the files in the directory [*], and send the ouput [|] to the more command. Here, in part, is the result:

See - there’s just no reason not to get to know your Linux system.