Frequently Asked Question

How is htop better than top, and which keys are worth memorising?

htop is a friendlier rewrite of top by Hisham Muhammad: colourful bars per CPU and memory pool, a scrollable process list, mouse support, tree view, and the ability to send signals, renice, or change a process's CPU affinity from the keyboard without leaving the interface. It reads the same /proc files, so it shows the same data, it just makes the data more legible. On any machine where you can install it, prefer it.

The keys worth knowing: F2 to enter setup (toggle colours, meter layout, what to sort by), F3 to search, F4 to filter, F5 to switch to tree view, F6 to choose a sort column, F9 to send a signal (default SIGTERM, but you can pick any), F10 to quit. t also toggles tree view; H toggles threads; K toggles kernel threads. u filters by user. a sets CPU affinity for the selected process. Once these are in your fingers, investigating "what is this machine doing right now?" takes seconds, not minutes.