Using expect to pass a password to ssh

Question

How can I use expect to send a password to an ssh connection.

say the password was p@ssword and the ssh command was ssh [email protected]

What would I do with expect to a make it input the password when it says

[email protected]'s password:
?

The proper action of using an SSH key pair isn't an option because I would have to use ssh (scp) to put the key on the server, which would ask for a password.

Answer 1

I always used the "proper" solution, but I used expect in other situations.

Here I found following suggestion:

#!/usr/local/bin/expect
spawn  sftp  -b cmdFile [email protected]
expect "password:"
send "shhh!\n";
interact

Answer 2

Would it not be easier to use public key authentication and use a key with no passphrase?

As the user on the source machine do this to make an RSA key

ssh-keygen -t rsa

Now copy ~/.ssh/id_rsa.pub to the target machine and append it to the authorized_keys file of the target user

Answer 3

Your quickest way forward (unless you want to become a Tcl expert, which would be... unusual... in 2009) is probably to use autoexpect. Here's the man page:

http://expect.nist.gov/example/autoexpect.man.html

In short, fire up autoexpect, run your ssh session, finish up what you need to do, stop autoexpecting and then beat your keyboard over the resulting mess until it works :) I'm assuming you don't need anything more than a quick hack to get your keys sorted out and then, well it sounds like you know the score already with that.

And there's this question which already contains an example close to what you seek.