Usefull script to check if a proxy is alive.
#!/bin/bash
# HTTP Proxy Server's IP Address (or URL)
proxy_server=$1
# HTTP Proxy Server's Port Number
port=$2
# We're trying to reach this url via the given HTTP Proxy Server
# (http://www.google.com by default)
url="http://www.google.com"
# Timeout time (in seconds)
timeout=20
# We're fetching the return code and assigning it to the $result variable
result=`HEAD -d -p http://$proxy_server:$port -t $timeout $url`
# If the return code is 200, we've reached to $url successfully
if [ "$result" = "200 OK" ]; then
echo "1 (proxy works)"
# Otherwise, we've got a problem (either the HTTP Proxy Server does not work
# or the request timed out)
else
echo "0 (proxy does not work or request timed out)"
fi