Updating Files from an External Resource

[Bioshox]

Like Wordpress does via the update

Download files from an external resource
Upload and Replace current Files and Folders on the server
Done

Use as a software updater

How would this be done?!

[Orjan]

Most likely, it's done with curl, or get_file_contents or similar, then stored on disk and after that unpacked/untared/unzipped with either own php code using the built in libraries, or using system calls to perform it.