Terminal Hacks - Monitor System Activity
This hack will show you how to display system information (process statistics and resource usage) as well as a real time list of processes and threads that are currently running. An alternative to having to open the Activity Monitor application on your Mac.

Show System Activity Monitor
Open Terminal: Finder > Applications > Utilities
In Terminal, type or paste the following…
top
(return)

By default %CPU is the default sort column (highlighted in white).
To exit the activity monitor, type or paste the following…
q
(return)
Show System Activity Monitor and Define a Column to Sort By
Open Terminal: Finder > Applications > Utilities
In Terminal, type or paste one of the following…
To sort by %CPU [central processing unit usage]top -o cpu
To sort by %MEM [memory usage]top -o mem
To sort by PID [a task's unique process ID]top -o pid
To sort by TIME [the amount of time in hundredths of a second a process has run for since last reboot]top -o time
To sort by COMMAND [the command that initiated the process]top -o command
(return)
::TIP:: you can sort by any column displayed in the activity monitor simply type the columns name after top -o .
Terminating a Process
Make a note of the PID ID number shown in the activity monitor.
Open Terminal: Finder > Applications > Utilities
In Terminal, type or paste one of the following…
kill 0000
[replace 0000 with the PID number of the process you wish to terminate]
(return)
Originally posted 31 January, 2025.