htop is an ncurses text interface task manager that can be controlled by the keyboard. htop can also close unresponsive programs by killing the process.
To view how much RAM is being used on your system is under :guilabel:`Mem` and then a [ number based on how many Gigabytes of memory. The :guilabel:`Swp` line lists how much swap is used. The numbers going down with a bar with a percentage next to them display usage on each of your CPU cores.
:guilabel:`Load average` shows your system load over the past one five and fifteen minute is why there are three numbers see `Wikipedia load (computing) <https://en.wikipedia.org/wiki/Load_(computing)>`_ for more information. :guilabel:`Uptime` shows how long your computer has been booted.
After the bottom there is a green bar that says :guilabel:`PID` for the Process ID of a user, The user the process responds to, :guilabel:`RES` is how much RAM the process is currently using. :guilabel:`CPU%` shows how much as a percent of CPU time the process is using, mem% is a percent of the RAM your process is using. :guilabel:`Time` shows how long the process has been running. :guilabel:`Command` shows the command line command of the process. To view any cut off part of the :guilabel:`Command` field press the :kbd:`Right Arrow` to view the cut off area of the window. To move your window back to where it was press the :kbd:`Left Arrow` key.
To select the process below the currently selected one press :kbd:`Down Arrow` to select the process below. To select the process above the currently selected one press :kbd:`Up Arrow` to select the process above. To select the next group of processes on your screen press :kbd:`Page Down`. To select the previous group of process on your screen press :kbd:`Page up`. To choose the last process on your system press the :kbd:`End` key. To choose the first process press the :kbd:`Home` key.
You can press :kbd:`F1` or :kbd:`?` to bring up a help dialog on htop. Pressing :kbd:`F3` or :kbd:`/` lets you search for a particular process. To reverse sort order press :kbd:`Shift +I`. Pressing :kbd:`F4` makes it so you can only see processes matching a certain pattern. To get out of the view of your search for a pattern press the :kbd:`Escape` key. Pressing :kbd:`F5` is what you press to view the processes in a tree. To get back to the default view press :kbd:`F5` again. Pressing :kbd:`F9` lets you kill a process with different signals to send to the process and 15 will terminate the process while 9 will Kill it. Lastly :kbd:`F10` will quit htop and return you to a terminal.
To change how your process are sorted press :kbd:`F6` which will bring up your own menu to sort by by :guilabel:`PID`, :guilabel:`USER`, :guilabel:`Priority`, :guilabel:`NICE`, :guilabel:`M_Size`, :guilabel:`M_Resident`, :guilabel:`M_Share`, :guilabel:`State`, :guilabel:`Percent_CPU`, :guilabel:`Percent_Mem`, :guilabel:`Time`, or :guilabel:`Command`.
:kbd:`F2` brings about a customizable settings on htop. The :guilabel:`Meters` brings up meters like CPU average. The :guilabel:`Display Options` has option for different ways to display in htop. The :guilabel:`Colors` tab brings up different color schemes for htop.
