sudo: How to switch Linux account user without the target user's password

Did you know if you have been granted sudo access to a remote host with su command, then you may switch to any user without the need to type in their password?

Try this out:

zemian@myhost bash> sudo su - postgres
# When prompted for password, enter your own user account password.

# Now you are in as `postgres` user!
postgres@myhost bash>

Or if you want to switch to the root user directly, simply try:

bash> sudo su -

This is very useful when you need to switch to a user account that was only setup just to run applications (eg: postgres, mysql, oracle, or weblogic etc.) and not intented for real user. In this case, you might not even know what the real password is. Above trick should get you switch into that target user account.