Script that allows the ssh-agent to be reused between terminals.
You only need to run it inside .bashrc, .zshrc or similar file as follow.
eval `/your_path/ssh-agent-reuse/ssh-agent-reuse.sh` &> /dev/null
Remember to give permissions to run.
chmod +x /your_path/ssh-agent-reuse/ssh-agent-reuse.sh
Tested in Debian Strecth.