Cheat sheet · 12 commands

Processes

Everything running on a machine is a process with a PID. ps and pgrep find them, kill sends them signals, and job control lets one terminal juggle several tasks at once.

The 3 you will use every day

Every running process

Find PIDs by command line

Ask a process to close cleanly

The full sheet

Every running processguide ›
Top memory consumersguide ›
Find PIDs by command lineguide ›
Live monitor (htop is friendlier)guide ›
Ask a process to close cleanlyguide ›
Force termination: last resort, nothing is savedguide ›
Signal processes matching a patternguide ›
Tell a daemon to reload its configurationguide ›
Run in the backgroundguide ›
List, foreground, resume background jobsguide ›
Keep running after you log outguide ›
Suspend the current foreground jobguide ›

Practise these for real in the interactive course, or keep every sheet, chapter and fix in one book: The Linux Command Line Handbook.