Zeus cannot bind to port 80. How do I find out what is already bound to it?

A useful utility for discovering which process is bound to a particular port is the tool 'lsof', available from ftp://vic.cc.purdue.edu/pub/tools/unix/lsof.

f can be used for many purposes (mostly to do with investigating open files and network sockets), see the man page for complete documentation; the following merely describes how to use it to determine the process running on a particular port:

lsof -i :[port-number]

Note that you will probably need to be root in order to get any output.

An example is given below:

localhost:~# lsof -i :80COMMAND    PID USER   FD   TYPE  DEVICE SIZE NODE NAMEzeus.web 23020 root   12u  IPv4 1142747       TCP *:www (LISTEN)zeus.web 23025 root   14u  IPv4 1142747       TCP *:www (LISTEN)

Content Manager [Administrator] 19 September 2005