agent="$HOME/.ssh-agent-$USER"
if [ -S "$SSH_AUTH_SOCK" ]; then
    case $SSH_AUTH_SOCK in
        /tmp/*/agent.[0-9]*)
        ln -snf "$SSH_AUTH_SOCK" $agent && export SSH_AUTH_SOCK=$agent
    esac
elif [ -S $agent ]; then
    export SSH_AUTH_SOCK=$agent
else
    echo "no ssh-agent"
fi