OS support: Linux

compile: make

usage: ./lab1_file_transfer <tcp | udp> <send | recv> [filename]

note: recv need to startup first, recv don't need filename

ex:
	./lab1_file_transfer tcp recv 127.0.0.1 5566
	./lab1_file_transfer tcp send 127.0.0.1 5566 test_input.txt
	
	./lab1_file_transfer udp recv 127.0.0.1 5566
	./lab1_file_transfer udp send 127.0.0.1 5566 test_input.txt