@NOVARSEG , is this a reply to my library? If so, you are allowed to ask it there. Or, for a quicker response, you can join the Discord server and ask any question about it and I will be able to see your questions sooner.
However, once again, I'm not so sure what it is you are asking. I'll take a stab at it, though. That function call is sending a 1024 byte (1 kilobyte) buffer read from the file to the FTP server.
I'll break the function down for you:
a: a is the return value of the boolean TRUE or FALSE from InternetWriteFile (the function which sends the buffer to the server).
hTransfer: hTransfer is the LONG handle to the session for writing to the file opened by FTPOpenFile
buffer: buffer is the 1024 (1 kilobyte) buffer read from the file
dwWrite: However many bytes are written to the server are then returned in that variable. You can use that to make sure that data is actually written.
I have no clue if I answered your question. If you need more help, reply at the FTP thread (or join the Discord) so when other people have questions then they can see what I answer as well. I'm going to paste the link to this thread in my FTP library thread so it can be found. Let's continue the discussion there.
https://www.qb64.org/forum/index.php?topic=3263.0