please don't call curl_init directly.

Please don't initate curl_init() directly but use Moodle's own "curl" class which is a wrapper on PHP's curl functions.

It's not documented well, but do a search on core moodle code for "curl" and you'll see examples of how it's used.

Many organisations put their moodle site behind a web proxy and the internal curl wrapper takes care of this and a number of security related settings.