ps

Whereas top is a continuously updating monitoring tool, ps gives us an instant snapshot of what our system is doing.

The most simple version of ps is to run it without arguments. It will return something like:

When running ps with no arguments, we will get information about processes runing in the particular terminal session that spawned the ps process. This is why the list is so short.

While I think many of these are self evident, an interesting one to talk about is TIME. This refers to how much time the CPU spent processing the command.

Useful commands

• ps x → display all processes running without the requirement to list only those with a TTY. (another way to see it: every process running as my user)
  • A ? in the TTY field means the process was started by the system
  • STAT refers to many things:
    • S means the process can’t be placed to sleep automatically
    • s means its a “process leading” in a process tree
    • R means the process is running
    • T means its stopped
• ps -He → Shows a process hierarchy or relationship.
  • H shows the relationship between processes
  • e shows all processes (same as A)
• ps -aux →