Testing for fopen and cURL

[CyberRanger]

I'd like to be able to test if a site has fopen on and cURL installed. Testing for fopen seems simple enough but how can I test for cURL? Do I need to do phpinfo and search the results cURL? What is phpinfo is not allowed?

Basic code structure:

PHP Code:

if(ini_get('allow_url_fopen') 
 { 
    // fopen is on
 } 
elseif (some test for cURL???)
 {
   // cURL is installed
 }
else
 {
   // neither fopen or cURL are available
 }