This is a code I made for my Networks project with another friend.

How to Use:

1)Copy the code onto two different machines or two different folders on the same machine 2)Start two different sessions, compile the code ( gcc Transfer.c -o client), and run it (./client)

3. The program asks you to enter the port on which it will listen, enter a value (eg: 5000)
4. Choose the mode (O for TCP and 1 for UDP)
5. Enter the server address to which you want to connect ( Eg: 6000)

Note: Now the program tries to connect with the server listening on this port and will wait till it establishes a connection

6. Once connection is established, the program will work.

Commands - A) Commands to check integrity of data: 1) FileHash CheckAll - Hashes all the files on the server (the OTHER folder/machine) and returns there md5 values 2) FileHash Verify - Hashes the corresponding file in server and prints its md5 when compared to the local copy B) Commands to get index/list of files on server 1) IndexGet ShortList - Gives info about requested file 2) IndexGet LongList - Gives List of all the files on the server 3) IndexGet Regex - Gives info of all the files on the server matching the regex (EG: "IndexGet Regex *.c" lists all C files present on the server)

C) Commands to transfer file data
	1) Upload <filename> - Command uploads a local file to the server. It asks permission from the other user before uploading.
		Eg: User1 : Upload a.txt
		    User2 sees " 
		    		 Someone wants to Upload File a.txt
		    		 Type "Allow" to let them, "Stop" to prevent them.
				"
		    If User2 types "Allow" Transfer happens, else its stopped
	2) Download <filename> - File is downloaded
D) Others
	1) q or Q - if written on a single line, all by itself, asks the local program to shut down. The server continues to run
	2) Any other data is interpreted as text and send as a chat msg. The server prints it out as such

Known Issues- 1) File Transfers (Upload or Download) though working in most cases, hang up while transferring certain kinds of files.[Certain pdfs/mp3 files] 2) Wrong Usage of commands may lead to a hangup 3) q closes the local copy and the client of the server. But the server needs to be closed manually

Use this code as you wish. Suggest changes/ edits to make this better.

Cheers