In this article I will show you the steps using which you can control the list of columns you would like to see with the top command.
By default we see the below columns when top is executed without any arguments
11584 root 20 0 116376 1012 844 R 99.9 0.0 18716:08 agetty
1 root 20 0 133792 4156 2552 S 0.0 0.0 0:38.09 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.04 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:01.31 ksoftirqd/0
5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H
7 root rt 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
Adding a new column
Here I would like to add one more field to monitor the "swap" memory usage per process
To do this, press "f" which will show you below list of options
Here if you see some of the options are bright white, these are the fields which are currently enabled by default, to which now we would like to add "SWAP" details
so navigate to the row which contains SWAP as shown below
and press "space" bar to select the highlighted option. Once you hit "space" bar, the highlighted option should turn to bright white color similar to other default options.
To go back to the home screen of top, press "Esc"
So now as you can see, a new column with "SWAP" has appeared at the last column
Similarly you can add any other column from the list of fields
Removing an existing column
To reduce or remove a column also similar steps can be followed as explained above
Press "f" to go to the list of fields and navigate to the option which you would like to remove from the default top home screen
Press "space" bar to un-select the field, by doing this the colour of the field would turn back to normal white colour similar to all other disabled sections as shown below, here I disabled "RES" memory column, press "Esc" to go back
So now the same has vanished from top home screen.
Save the changes permanently
To save the changes what you have made, so that the same is active when you execute top next time
Once you press the same, you should see the above line as shown in the screenshot. The changes will be saved under your home folder using which top was executed
Below is the content of my /root/.toprc
Id:i, Mode_altscr=0, Mode_irixps=1, Delay_time=3.0, Curwin=0
&')*+,-.winflags=193844, sortindx=18, maxtasks=0, graph_cpus=0, graph_mems=0
summclr=1, msgsclr=1, headclr=3, taskclr=1
)*+,-./0winflags=193844, sortindx=0, maxtasks=0, graph_cpus=0, graph_mems=0
summclr=6, msgsclr=6, headclr=7, taskclr=6
winflags=193844, sortindx=21, maxtasks=0, graph_cpus=0, graph_mems=0
summclr=5, msgsclr=5, headclr=4, taskclr=5
)+,-./12winflags=193844, sortindx=3, maxtasks=0, graph_cpus=0, graph_mems=0
summclr=3, msgsclr=3, headclr=2, taskclr=3
Fixed_widest=0, Summ_mscale=0, Task_mscale=0, Zero_suppress=0
I hope the article was useful.