ps

ps shows which processes are running

I usually run ps like this: $ ps aux

u means include username column
a+x together show all processes

(ps -ef works too)

w

is for wide. ps auxwww will show all the command like args for each process

e

is for environment. ps auxe will show the environment vars!

wchan

you can choose which columns to show with ps (ps -eo...)

One cool column is ‘wchan’, which tells you the name of the kernel function if the process is sleeping.

try it:
$ ps -eo user,pid,wchan,cmd

process state

Here’s what the letters in ps’s STATE column mean:

• R: running
• S/D: asleep
• Z: zombie
• l: multithreaded
• +: in the foreground

f

is for “forest” :) ps auxf will show you an ASCII art process tree!

pstree can display a process tree, too.

ps has 3 different sets of command line arguments

(broken heart)

1. UNIX (1 dash)
2. BSD (no dash)
3. GNU (2 dashes)

you can write monstrosities like: $ ps f -f

f is “forest” (BSD)
-f is “full format” (UNIX)