Ubuntu Basic Terminal commands Limit output to lines with the desired string
Example
If you are running a command that returns hundreds of lines, but your interest is just on the lines that contains the word <word>, you should definitely use grep! For example try running:
ifconfig -a
Check the output, that could be only a few lines or quite long, if you have a server with multiple network interfaces. To show (for example purpose) only the lines that contain 'HWaddr', try using grep:
ifconfig -a | grep HWaddr
Now the output should be much shorter! Generally speaking, you could use grep in the following way:
<command-with-output> | grep <word>
