expectでsshのパスフレーズ付き鍵認証を自動化

expect_ssh_key_with_passphrase.sh

#! /bin/bash

host=xxx.xxx.xxx.xxx
login_name=hoge
key=/xxxx/xxxx/xxxx/id_rsa
passphrase=xxxxxxxx

if [ -z `ssh-add -l | grep $key | awk '{print $3}'` ]; then
    expect -c "
    set timeout -1
    spawn ssh-add $key
    expect \"Enter passphrase for $key:\"
    send \"$passphrase\n\"
    interact
    "
fi

ssh -l $login_name -i $key $host