Bash - run remote command as superuser using ssh connection with plink command

In this short article, we would like to show how to run some command as a superuser on remote host, using ssh connection with plink command in Bash.

Quick solution:

plink -pw user_password user@$my-domain.com "su - root -c 'ls -al /root' <<< 'root_password'" 2> /dev/null

Note: motivation to use plink command instead of ssh command is the possibility to pass the password as a parameter (-pw parameter).

Practical example

In this example, all parameters are stored in variables (username and password as a variable in the script).

#!/bin/bash

SERVER_HOST='88.77.55.44'
SERVER_PORT=22

USER_NAME='john'
USER_PASSWORD='secret_john_password'
ADMIN_NAME='root'
ADMIN_PASSWORD='secret_root_password'

REMOTE_COMMAND='ls -al /'

plink -P "${SERVER_PORT}" -pw "${USER_PASSWORD}" "${USER_NAME}@${SERVER_HOST}" "su - '$ADMIN_NAME' -c '${REMOTE_COMMAND}' <<< '${ADMIN_PASSWORD}'" 2> /dev/null

Where main concept is to:

1. get a connection with the server as a normal user,
2. run su command executing some another command,
3. inject superuser password with <<<,
4. ignore Password: prompt with 2> /dev/null - we want to see executed command output only.

plink installation

Under Windows, you can use putty installer (go to MSI (‘Windows Installer’) section).

Under Debian based Linux run:

sudo apt-get update
sudo apt-get install plink