Linux.com: CLI Magic: Information, Please

“There are lots of ways the CLI can help you. Often, you don’t
need to do something so much as you need to know something. This
week we’ll take a quick look at several commands–whereis, whatis,
df, kernelversion, ifconfig, route, and last–that can quickly
answer questions about your system or configuration. Wipe that GUI
mess out of your eyes and meet me at the CLI.

“You know the command is on your system, because you’ve used it
before. But now you can’t remember where it lives. Is it in /sbin?
Or /usr/bin? Somewhere else? The whereis command is designed to
answer that very question. In fact, whereis will tell you not only
where to find the executable command, but the source code–if it’s
present–and man pages as well…”

Complete
Story