What Does the "ps aux" Shell Command Do?

The ps command in shell lists all the processes running on the system, and includes information such as the process id, parent process id, process user/owner, CPU usage, memory usage, etc. This can be useful, for example, for identifying and troubleshooting problems with programs or active processes.

The "aux" specified after the ps command is merely different options mixed together, that do the following:

• a — shows processes for all users;
• u — shows the user/owner of processes;
• x — includes processes that are not attached to a terminal.

For example, running the ps aux command in a shell might produce an output like the following:

USER     PID    %CPU %MEM  VSZ    RSS    TTY  STAT START   TIME  COMMAND
nobody   30721  0.0  0.1   220292 10014  ?    S    15:01   0:01  /usr/sbin/httpd
mysql    2116   0.1  4.6   144164 283521 ?    Ssl  Jul01   80:28 /usr/sbin/mysqld
# ...

For detailed information you can run the man ps command in terminal.