sshpass: Login To SSH Server / Provide SSH Password Using A Shell Script

How do I login over ssh without using password less RSA / DSA public keys? How do I use ssh in a shell script? How do I login non-interactivly performing password authentication with SSH and shell scripts?

You can use sshpass command to provide password for ssh based login. From the man page:

sshpass is a utility designed for running ssh using the mode referred to as "keyboard-interactive" password authentication, but in non-interactive mode.

ssh uses direct TTY access to make sure that the password is indeed issued by an interactive keyboard user. Sshpass runs ssh in a dedicated tty, fooling it into thinking it is getting the password from an interactive user.
The command to run is specified after sshpass' own options. Typically it will be "ssh" with arguments, but it can just as well be any other command. The password prompt used by ssh is, however, currently hardcoded into sshpass.

WARNING! These examples considered the least secure as simple ps command can expose password to all users on the same host. I highly recommend using ssh's public key authentication or keychain software to set up secure passwordless SSH access

Install sshpass under Debian / Ubuntu Linux

Type the following command:
$ sudo apt-get install sshpass

How do I use sshpass?

Login to ssh server called server.example.com with password called t@uyM59bQ:
$ sshpass -p 't@uyM59bQ' ssh username@server.example.com
Under shell script you may need to disable host key checking:
$ sshpass -p 't@uyM59bQ' ssh -o StrictHostKeyChecking=no username@server.example.com

How do I backup /var/www/html using rsync?

Run rsync over SSH using password authentication, passing the password on the command line:
$ rsync --rsh="sshpass -p myPassword ssh -l username" server.example.com:/var/www/html/ /backup/