To check performance of the Unix/Linux box top command is used frequently. This is what top‘s output usually looks like:
While top command is very useful, it has very clumsy "human interface". There is a much better alternative to top – htop which is a free (GPL) ncurses-based process viewer. It is similar to top, but allows to scroll the list vertically and horizontally to see all processes and their full command lines. Tasks related to processes (killing, renicing) can be done without entering their PIDs, and of course htop has a much better human interface that looks similar to:
Comparison between htop and top
- In ‘htop’ you can scroll the list vertically and horizontally to see all processes and complete command lines.
- In ‘top’ you are subject to a delay for each unassigned key you press (especially annoying when multi-key escape sequences are triggered by accident).
- ‘htop’ starts faster (‘top’ seems to collect data for a while before displaying anything).
- In ‘htop’ you don’t need to type the process number to kill a process, in ‘top’ you do.
- In ‘htop’ you don’t need to type the process number or the priority value to renice a process, in ‘top’ you do.
- ‘htop’ supports mouse operation, ‘top’ doesn’t
- ‘top’ is older, hence, more used and tested
htop is an Open Source project, hence can be easily downloaded and installed on U/Linux system. For example it can be downloaded and installed on Ubuntu with just one command:
sudo apt-get install htop
Be aware! It appears that although ‘htop’ provides some cool enhancements, ‘top’ remains to be one of the sexiest Unix commands ever according to GOOGLE. Just search for "man top" and along with "Unix Manual Pages for top" get "Man on Top Sex Positions" from GOOGLE. :)