9. Process States
Let's take a look at the ps aux command again:
$ ps aux
In the STAT column, you'll see lots of values. A linux process can be in a number of different states. The most common state codes you'll see are described below:
- R: running or runnable, it is just waiting for the CPU to process it
- S: Interruptible sleep, waiting for an event to complete, such as input from the terminal
- D: Uninterruptible sleep, processes that cannot be killed or interrupted with a signal, usually to make them go away you have to reboot or fix the issue
- Z: Zombie, we discussed in a previous lesson that zombies are terminated processes that are waiting to have their statuses collected
- T: Stopped, a process that has been suspended/stopped
Take a look at the running processes on your system and check out their process states.
What STAT code is used to represent an uninterruptible sleep?