How to replace tab as spaces in vim?

1. set the options permanently

echo 'set ts=4' >> .exrc
echo 'set shiftwidth=4' >> .exrc
echo 'set sts=4' >> .exrc
echo 'set expandtab' >> .exrc

 

2. set the options every time;

set ts=4
set shiftwidth=4
set sts=4
set expandtab