Using shell script how to switch user and change folder

Hi All,

I am new to schell script, I am trying to achieve the following with a shell script, kindly advise, thanks

1) change user say sudo su - oracle
2) the change folder to cd /sw/database
3) tail -f alert.log

Another shell for;

1) change user say sudo su - oracle
2) sqlplus '/as sysdba'
3) startup

change user say sudo su - oracle
2) the change folder to cd /sw/database
3) tail -f alert.log

For the first thing, at least, you should be able to do a one-liner like so:

sudo -u oracle tail -f /sw/database/alert.log

Just put that in a script and run the script.