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Process management

Each time you run a command or application, you start a process. Each process is given a unique number; called its process ID (PID).

To determine which processes are hogging resources (CPU time and memory), and to kill a rogue process, you have at your disposal the commands, ps, kill, and top.

$ ps - process

ps
Display processes running in current shell session.

TTY is short for teletype (once a major manufacturer of Unix terminals). Here the second console (tty2) is being used. In a (second) terminal window this would appear as pts/2. TIME is the total CPU time spent on the process.

ps aux
Display every process, by all users. (a to display all processes running from a terminal, u to display username with process, x to display all processes not running from a terminal.)

ps aux | grep bash
Display every 'bash' process. Ideal for obtaining the PID in order to kill a rogue process.

$ kill

kill 101
Kill the process with the PID, 101.

$ top

top
Display processes in realtime. Handy for determining what's hogging your CPU and memory.

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