I still cannot figure out hook, the values passed to it(or jus, received (why not passed, or where passed from?)) and what executes it.

Well, CGI explains all that in Progress bars for file uploads and avoiding_temp files but what happens is, CGI has a socket for the upload, every time it reads a chunk from the socket, it calls the hook with the new data, which is where your parameters are coming from.

In reply to Re^8: file upload and IO::Handle by rowdog
in thread file upload and IO::Handle by Anonymous Monk

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