[ale] Best way to disable command-line access?

[ametts2 at mindspring.com (Allan Metts)]

Hi everyone,

What's the best way to preserve the ability to transfer files with scp, but PREVENT someone from using those same ssh credentials to get to a command line?  This is for a single user only -- other users of the same server should be able to log in as usual.

I tried usermod -s <a_script_that_does_nothing> <user>, but this seems to prevent scp file transfers as well.

Is there a user-specific ssh config setting that does this?  Any other ideas?

Thanks in advance,
Allan