Need help with a shell script:Config Transparent Proxy using Shell

I want to config Transparent Proxy using Shell Script.
I have more questions<exercise of me :D>:
+ Check that the squid is installed or not install and version is installed
+Allows users to choose to run a transparent proxy or not
+Perform configuration and turn on service in accordance with the requirements of users and the correct version of the squid proxy
+Print out information about user options and configuration parameters corresponding

Are u help me?
Thanks :smiley: