Can a shell script set environment variables of the calling shell? [duplicate]

Answer 1

In my .bash_profile I have :

# No Proxy
function noproxy
{
    /usr/local/sbin/noproxy  #turn off proxy server
    unset http_proxy HTTP_PROXY https_proxy HTTPs_PROXY
}


# Proxy
function setproxy
{
    sh /usr/local/sbin/proxyon  #turn on proxy server 
    http_proxy=http://127.0.0.1:8118/
    HTTP_PROXY=$http_proxy
    https_proxy=$http_proxy
    HTTPS_PROXY=$https_proxy
    export http_proxy https_proxy HTTP_PROXY HTTPS_PROXY
}

So when I want to disable the proxy, the function(s) run in the login shell and sets the variables as expected and wanted.