This bash script enables you to Screen Share with a remote machine using Apple's built-in screen sharing tools.

screen-share.sh

#!/bin/bash

# This will open Apple's Screen Sharing tool and connect to the desired machine
# Replace the username and password with the details of the remote machine you wish to connect to
# That goes for the IP address as well.

# Usage #

# Make the script executable with "chmod +x screen-share.sh" and then run it with: 
# "./screen-share.sh
open -a Finder vnc://username:password@ip_address