こんなのを .zshrc とかに入れて幸せをつかむ
SSH_AGENT_PID=`ps ax | grep ssh-agent | grep -v grep | awk '{print $1}'`
if [ x$SSH_AGENT_PID != x ]; then
PID=`expr $SSH_AGENT_PID - 1`
SSH_AUTH_SOCK=`/bin/ls /tmp/ssh-???$PID/agent.$PID`
if [ x$SSH_AUTH_SOCK != x ]; then
export SSH_AGENT_PID SSH_AUTH_SOCK
fi
fi