su - switch to another user
$ su [-] [user]
$ su [-] [user] [-c command]su: Switch to another user.
When called with no user-specified, su defaults to switch to the root user. Need to enter the password if the user switch to has one.
-, -l, --login: Start the shell as it was a real login-c, --command: Execute a command using /bin/sh instead of starting an interactive shelluser: User to switch to (defaults to the user with UID 0)Switch to root user
$ suSwitch to another user
$ su nona