How to receive the image file upload requestpayload on the server

(Note: The segmengtfault tag will automatically help me submit it to the sub-site Q & A. It is not reasonable, so I will rewrite it here) in studying segmentfault file upload, we can see that the request has been constructed normally, as shown in figure: I want to ask the following question: This is constructed according to the standard RFC1867...

(Note: The segmengtfault tag will automatically help me submit it to the sub-site Q & A. No one cares, so I will rewrite it here)
After studying the segmentfault file upload, we can see that the request has been constructed normally, as shown in:

Would you like to ask how the server handles such requests constructed according to the standard RFC 1867, is there a ready-made library for use? Or is it just a common string and various split operations?

Reply content:

(Note: The segmengtfault tag will automatically help me submit it to the sub-site Q & A. No one cares, so I will rewrite it here)
After studying the segmentfault file upload, we can see that the request has been constructed normally, as shown in:

Would you like to ask how the server handles such requests constructed according to the standard RFC 1867, is there a ready-made library for use? Or is it just a common string and various split operations?

Depends on the language and framework used by the server.
Most languages and frameworks do not require programmers to participate in parsing this level of Protocols. A small part of them allow programmers to participate, but all have ready-made libraries available for use.