How do I Use the Unix Top Command?

The Unix top command is designed to help users determine which processes are running and which applications are using more memory or processing power than they should be. It is an extremely useful command for those looking to reduce the memory footprint on their Unix installation or for those who like a more responsive, more streamlined computing environment. The Unix top command is a highly useful tool that will come in handy in a variety of situations. Furthermore, by default, the Unix top command will update its findings on a regular basis, usually every few seconds, so that a user can get a real time picture of what the computer is doing at any given moment.


The top command is very easy to use and requires little to no prior knowledge of how Unix commands work. It can be run by anyone, so long as they know how to enter text into the command line or terminal.

How to Run the Unix Top Command

Top can either be run by itself, simply by typing top into the command line, or it can be used with a variety of parameters in mind. Some of the most common, and must used, parameters include: -d which specifies the delay between real time updates, -n which is designed to specify how many iterations to produce before the program automatically ends, and -p which monitors specific process IDs.

While the Unix top command is operating, it can be further controlled through a variety of other keyboard commands. Of these commands, the most important occurs by pressing the "h" or "?" keys to bring up the help menu. This menu will provide you with a quick list of all of the other available commands for easy access. Furthermore, if the user wishes to close the Unix top command at any time, he or she can do so by simply pressing the "q" key to quit the program.