Monitoring processes using ps

We have used the command ps in the introduction. Let's learn more about it:

• To list the process associated with our current Bash shell terminal, enter the following command:

  $ ps
  

  
• To list processes along with the parent process ID associated with the current terminal, enter the following command:

  $ ps –f
  

  

  We can see the process ID in the PID column and the parent process ID in the PPID column in the preceding output.

• To list processes with the parent process ID along with the process state, enter the following command:

  $ ps –lf
  

  

  In the preceding output, the column with S (state) shows the current state of a process, such as R for running and S for suspended state.

• To list all the processes running in the operating system including system processes, enter the following command:

  $ ps –ef
  

  

  The process names in [] are kernel threads. If you are interested in more options to learn about the ps command, you can use the following command:

  $ man ps.
  

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