Start ssh-agent on opening shell, if not running yet (Git bash environment)

.bash_profile

# Based on script from Github Help:
# https://docs.github.com/en/free-pro-team@latest/github/authenticating-to-github/working-with-ssh-key-passphrases#auto-launching-ssh-agent-on-git-for-windows

env=~/.ssh/agent.env

agent_load_env () { test -f "$env" && . "$env" >| /dev/null ; }

agent_start () {
    (umask 077; ssh-agent >| "$env")
    . "$env" >| /dev/null ; }

agent_load_env

# agent_run_state: 0=agent running w/ key; 1=agent w/o key; 2= agent not running
agent_run_state=$(ssh-add -l >| /dev/null 2>&1; echo $?)

if [ ! "$SSH_AUTH_SOCK" ] || [ $agent_run_state = 2 ]; then
    agent_start
fi

unset env