Set proxy in a shell.

gistfile1.sh

function proxy () {
    UNSET=""
    PROXY="http://127.0.0.1:8080"
    PROXY_ENV=(http_proxy https_proxy ftp_proxy HTTP_PROXY HTTPS_PROXY FTP_PROXY)
    if [ $1 == on ]; then
        for i in $PROXY_ENV; do
            export $i=$PROXY
        done
        echo "proxy set"
    elif [ $1 == off ]; then
        for i in $PORXY_ENV; do
            unset $i
        done
        echo "proxy unset"
    fi
}