How to set memory usage sort in top command as default?
Solution 1:
Start it with
top -o %MEM
You can create an alias: alias top='top -o %MEM' in ~/.bashrc) for this.
Easier method: top can save to a configuration using W.
W :Write-the-Configuration-File This will save all of your options and toggles plus the current display mode and delay time. By issuing this command just before quitting top, you will be able to restart later in exactly that same state.
It saves to ~/.toprc. Going back to default is the same as removing ~/.toprc.