ps Command: Tutorial & Examples
Display information about running processes
ps command is used to display information about the currently running processes on a Linux system. To use it, you can simply type
ps followed by any number of options that
modify the output.
Here are some common options you can use with
-a: Display all processes that are owned by the current user.
-x: Display processes that are not associated with a terminal.
-u: Display the process owner and the process command name.
-e: Display all processes.
For example, to display all processes that are owned by the current user, you could use the following command:
The output of
ps will contain several columns of information about each process. Here is a brief explanation of each column:
- PID: The process ID, a unique number assigned to each process.
- TTY: The terminal associated with the process.
- TIME: The amount of CPU time used by the process.
- CMD: The command that was used to start the process.
For example, the output of
ps -u might look something like this:
PID TTY TIME CMD 123 ? 00:00:01 bash 456 ? 00:00:00 gedit 789 ? 00:00:00 firefox
This shows that there are three processes running: a bash shell, the gedit text editor, and the firefox web browser. The PID column shows the process ID for each process, the TTY column shows the terminal associated with the process, and the TIME column shows the amount of CPU time used by the process.
You can also use the
ps command with the
grep command to search for specific processes. For example, to find all processes with the name "firefox", you
could use the following command:
ps -e | grep firefox
This will display all processes, and
grep will filter the output to only show lines that contain the string "firefox".