Automatically enable/disable proxy settings from command line

.bashrc

# Show proxy settings
function proxy_show(){
   env | grep -e _PROXY -e _proxy | sort
}

# Configure proxy
function proxy_on(){
   # You may need to hardcode your password, proxy server, and proxy port
   # if the following variables do not exist
   export HTTP_PROXY="http://$USERNAME:$PASSWORD@$PROXY_SERVER:$PROXY_PORT"
   export HTTPS_PROXY=$HTTP_PROXY
   export FTP_PROXY=$HTTP_PROXY
   export http_proxy=$HTTP_PROXY
   export https_proxy=$HTTP_PROXY
   export ftp_proxy=$HTTP_PROXY
   # export SOCKS_PROXY=$HTTP_PROXY
   # export no_proxy="localhost,127.0.0.1,$USERDNSDOMAIN"
   export no_proxy="localhost,127.0.0.0/8,::1"

   # Update git and npm to use the proxy
   if hash git 2>/dev/null; then
     git config --global http.proxy $HTTP_PROXY
     git config --global https.proxy $HTTP_PROXY
   fi
   
   if hash npm 2>/dev/null; then
     npm config set proxy $HTTP_PROXY
     npm config set https-proxy $HTTP_PROXY
     # npm config set strict-ssl false
     # npm config set registry "http://registry.npmjs.org/"
   fi

   proxy_show
   echo -e "\nProxy-related environment variables set."

   # clear
}

# Enable proxy settings immediately
# proxy_on

# Disable proxy settings
function proxy_off(){
   variables=( \
      "HTTP_PROXY" "HTTPS_PROXY" "FTP_PROXY" \
      "no_proxy" "http_proxy" "https_proxy" "ftp_proxy" \
   )

   for i in "${variables[@]}"
   do
      unset $i
   done
   
   # Update git and npm to disable the proxy
   if hash git 2>/dev/null; then
     git config --global --unset http.proxy
     git config --global --unset https.proxy
   fi
   
   if hash npm 2>/dev/null; then
     npm config rm proxy
     npm config rm https-proxy
     # npm config set strict-ssl false
     # npm config set registry "http://registry.npmjs.org/"
   fi

   proxy_show
   echo -e "\nProxy-related environment variables removed."
}

Readme.md

At any time you can type proxy_on/proxy_off to enable/disable proxy.

You may need to hardcode your password, proxy server, and proxy port on line 11. Just replace each $VAR_NAME with the actual value.

Put this file in your home directory. Make sure the file is called .bashrc. Append this to the file if it already exists.