dotfilesのシェルスクリプトをosごとにかき分ける（linuxはディストリビューションごとに）

分類は以下でできます。
あとは読み込むファイルを分けておいて、
必要に応じてsourceしていけばOKです。

case ${OSTYPE} in
    darwin*)
        echo "Running on OSX"
        source install/brew.sh
        ;;
    linux*)
        if   [ -e /etc/debian_version ] ||
                 [ -e /etc/debian_release ]; then
            # Check Ubuntu or Debian
            if [ -e /etc/lsb-release ]; then
                # Ubuntu
                distri_name="ubuntu"
            else
                # Debian
                distri_name="debian"
            fi
        elif [ -e /etc/fedora-release ]; then
            # Fedra
            distri_name="fedora"
        elif [ -e /etc/redhat-release ]; then
            if [ -e /etc/oracle-release ]; then
                # Oracle Linux
                distri_name="oracle"
            else
                # Red Hat Enterprise Linux
                # CentOS
                distri_name="redhat"
            fi
        elif [ -e /etc/turbolinux-release ]; then
            # Turbolinux
            distri_name="turbol"
        elif [ -e /etc/SuSE-release ]; then
            # SuSE Linux
            distri_name="suse"
        elif [ -e /etc/mandriva-release ]; then
            # Mandriva Linux
            distri_name="mandriva"
        elif [ -e /etc/vine-release ]; then
            # Vine Linux
            distri_name="vine"
        elif [ -e /etc/gentoo-release ]; then
            # Gentoo Linux
            distri_name="gentoo"
        else
            # Other
            echo "unkown distribution"
            distri_name="unkown"
        fi
        ;;
esac