Switch user in a init script?

Question

Here's my Init script which I have at my Ubuntu workstation. I need to run a command as another user than root, but I just can't get my head around how it should be done. Neither sudo -u or su newuser seems to work.

The script:

respawn
console none

start on runlevel [2345]
stop on runlevel [06]

script
  su "anotherUser" -c ./myCommand
end script

Answer 1

I use this:

su -l $MUSER -c "myCommand args..."

Update: Since there is interest in this answer, I explain the way I use it here.

We run servers as normal linux users, not root. The username contains three parts:

service, customer, stage

This way we can run several services for several customers in one linux OS.

Example: foo_bar_p Service "foo" of customer "bar" and "p" means production

Here is the part of the init script. The init script can be executed as root or as foo_bar_p user:

# /etc/init.d/foo_bar_p-celeryd
# scriptname contains linux username  
SCRIPT_NAME=`basename "$0"`
SYSTEM=${SCRIPT_NAME%*-celeryd}

U=`id -nu`

if [ ! $U == $SYSTEM ]; then
    if [ $U == "root" ]; then
        # use "-l (login)" to delete the environment variables of the calling shell.
        exec su -l $SYSTEM -c "$0 $@"
    fi
    echo "Script must be run from $SYSTEM or root. You are '$U'"
    rc_exit 1
fi

# OK, now I am foo_bar_p
cd
. $HOME/.bashrc
....