To be user friendly not always a utility has to have a GUI you know ;-). There are some decent amount of command-line based system monitors in GNU/Linux that one can try. nmon system monitor for instance is an excellent little tool. And another similar one (very popular) is the utility known as “htop”.
Being a command-line based system monitor it uses very little of your system resources while running. Just like with “nmon” it lets you change its appearance and enable/disable monitoring hardware devices.
Once “inside” its window I feel like I’m inside of an Alien space ship too :D. I’m not gonna do all the features here …
But some of its main feature to mention are…
*. CPU, Memory (RAM) and Swap memory info are put on top of the window with “ncursed” based graphical bars which is cool! (supports “Bars”, “Text”, “LED” and “Graphs” output styles).
*. System up-time, Average load and running processes are located on the top right corner. So a glance is enough to get a general idea of the suffering your PC’s going through at the moment ;-).
*. And the rest of the screen is dedicated to the running processes with advanced information such as: User id, process id, NI (“nice value”: represents the priority of a process), CPU and Memory usage, Time elapsed, the path of the process execution and few other details.
*. As you can see from the first screenshot, you can easily change the arrangements and other settings by simply pressing the “F2” key on your keyboard (other “F” keys are also being used to access various features of htop as well).
*. Search for processes.
*. Kill a process.
*. Change the update interval.
You can also change the default look-n-feel (including the top “meter” location etc) of “htop” as it comes with few color themes too.
If interested, you can install “htop” in Ubuntu 12.04 Precise Pangolin, 11.10 Oneiric Ocelot, 11.04 Natty Narwhal, 10.10 and 10.04 by simply entering the below command in your Terminal window.
sudo apt-get install htop
You can easily change the update interval (in seconds) by using the “d” attribute. For instance, if I want updates every second, then I’ll use …
htop -d 1
Just replace “1” with your preferred seconds interval. You can also read its manual by using the below command.
Although I’m not criticizing the default one in Ubuntu but as you can see from the below screenshot, “htop” being a “ncurses” and command-line based tool, it uses like 0.3 MB of RAM and 2% of CPU usage where at the same time Gnome system monitor uses about 7% of CPU and 2.8 MB of RAM.
So when comparing system resources, htop is extremely lightweight too.
So, if you want a fast loading, extremely lightweight system monitor that can be launched through command-line then heck, “htop” is a bloody serious looking utility, thumbs up!.