lsof -i :80
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
gnome-pan 28597 murat 18u IPv4 2907888 0t0 TCP ....
gnome-pan 28597 murat 19u IPv4 2907903 0t0 TCP ....
dropbox 28624 murat 18u IPv4 2755213 0t0 TCP ...
When i list open files with -i switch i found out that some processes have the same fd's.For example above output, 28597 and 28624 pid's have the same fd's.That means these process can reach the same memory space.What is the reason for this ? How can they reach the same area and why ? Also what's the meaning of u (18u) ? Some fd's are end up with w.