ls -Slh

-S will sort files by size
-l long listing
-h will make the output human-readable
-r will reverse the output

Edit file ~/.bash_aliases

nano ~/.bash_aliases

For example I make alias a. So when I press a it will produce php artisan tinker Here file ~/.bash_aliases

alias a='php artisan tinker'

Load aliases immediately

source ~/.bash_aliases

Show process list sorted by memory usage

ps aux --sort=-%mem | awk 'NR<=800{print $0}'

Show process list with full start date

ps -eo pid,lstart,cmd