gistfile1.txt

function p() {
    case "$1" in
        up|on)
            export http_proxy="http://proxy:3128"
            export https_proxy="http://proxy:3128"
            export ftp_proxy="http://proxy:3128"
            echo "proxy on!"
            ;;
        down|off)
            unset http_proxy https_proxy ftp_proxy
            echo "proxy off!"
            ;;
        *)
            echo ${http_proxy:-off}
            ;;
    esac
}