changing user for command

Either use sudo, to give user webuser hank's priviledges or use eXpect (http://expect.nist.gov/) to write a script that passes the password.

sudo is probably better, with the NOPASSWD option, man sudo for details

To log on to a server as a different user

ssh -l username server

or

ssh username@server

Im not 100% on what you are trying to achieve are you coping files from one server to another? Or locally copying files once logged in on the remote computer?
If its a local copy the syntax is correct if you are copying from a remote comp to local you need to use

scp -rp user@remote:/path/to/files user@local:/path/to/files

Thanks!

What I am actually trying to accomplish is to get a web script to copy local files to a different local directory.  Because of this there must not be a password prompt.

Looks like sudo should do what I need.

    http://www.courtesan.com/sudo/man/sudo.html


but I can't figure out how to enter the password for "hank"

          sudo -u webadmin -p %U mypassword cp -pr /home/web/mysite.com/html/source /home/web/mysite.com/html/dest

does not work.

How can I proporly pass the username and password values?

Thanks