How to List Linux Processes by Memory Usage

Use this command to list Linux processes according to their memory usage in descending order (via Linux Questions):

ps -e -orss=,args= | sort -b -k1,1nr | pr -TW$COLUMNS

The output will look something like this:

181300 /usr/sbin/clamd
64144 amavisd (ch9-avail)
63256 amavisd (ch11-avail)
22196 /usr/sbin/apache2 -k start
21856 /usr/sbin/apache2 -k start
21280 /usr/sbin/apache2 -k start
...
...