.sh-ssh

# From https://bitbucket.org/snippets/Rockin4Life33/xAaqBn

# Note: ~/.ssh/environment should not be used, as it already has a different purpose in SSH,
#       if the file `agent.env` does not exist it will be created and populated
SSH_ENV=~/.ssh/agent.env

agent_is_running() {
    if [ "$SSH_AUTH_SOCK" ]; then
        # ssh-add returns:
        #   0 = agent running, has keys
        #   1 = agent running, no keys
        #   2 = agent not running
        ssh-add -l > /dev/null 2>&1 || [ $? -eq 1 ]
    else
        false
    fi
}

agent_has_keys() {
    ssh-add -l > /dev/null 2>&1
}

agent_load_env() {
    . "$SSH_ENV" > /dev/null 2>&1
}

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

if ! agent_is_running; then
    agent_load_env
fi

if ! agent_is_running; then
    agent_start
    ssh-add ~/.ssh/id_rsa
elif ! agent_has_keys; then
    ssh-add ~/.ssh/id_rsa
fi

unset SSH_ENV