In order to establish a connection - there needs to be a 1) sender (server) (the owner of the file), waiting for connections, and a 2) receiver (client), who will try to connect to a sender (server). If the requirements are met - a client will connect to a server and the packet exchange will begin.
The server and the client needs to communicate with packets according to certain rules, given by a [protocol](https://github.com/Unbewohnte/FTU/tree/main/protocol).
The packet has its header and body. They are divided into several groups of use by headers, this way we can specify what kind of data is stored inside packet`s body and react accordingly.
Thus, with a connection and a way of communication, the sender will send some packets with necessary information about the file to the receiver that describe a filename, its size and a checksum. The client (receiver) will have the choice of accepting or rejecting the packet. If rejected - the connection will be closed and the program will exit. If accepted - the file will be transferred via packets.
- If `MAXFILEDATASIZE` is bigger than appr. 1024 - the packets on the other end will not be unmarshalled due to error ??; FIXED - [x], unnecessary, wrong, deprecated, **destroyed !!!**
-`go build` - to simply compile for your OS/ARCHITECTURE || `CGO_ENABLED=0 GOOS=os_here GOARCH=arch_here go build` - to cross-compile a static executable for the OS/ARCHITECTURE of your choice (`go tool dist list` - to view the available ones)
### After installation
- You probably want to put the executable in some folder and in order not to use it directly from there all the time - add it to the **$PATH** variable
-`-sharefile` (string) - specifies path to a file you want to share, if given a valid path - sender will offer to download this file to receiver;
-`-downloadto` (string) - specifies path to a folder where the receiver wants to store downloaded file;
### Examples
-`./FTU -sharefile="/home/some_path_here/FILETOSHARE.zip"` - creates a server that will share `FILETOSHARE.zip` on port `8080`
-`./FTU -sharefile="/home/some_path_here/FILETOSHARE.zip" - port=727` - same as before, but on port `727`
-`./FTU -downloadto="/home/some_path_here/Downloads/" -addr="192.168.1.104"` - creates a client (receiver) that will try to connect to `192.168.1.104` (local device) on port `8080` and if successful - downloads a file to given path
-`./FTU -downloadto="/home/some_path_here/Downloads/" -addr=145.125.53.212 -port=8888` - same as before, but will try to connect to `145.125.53.212` on port `8888`
This is NOT intended to be a serious application. I'm learning and this is a product of my curiosity. If you're a beginner too, please don't try to find something useful in my code, I am not an expert.
Also, this utility only works if both the server and the client have a port-forwarding|virtual server enabled and configured. Fortunatelly, locally it works without any port-forwarding|virtual servers.
