Opens a socket of the specified kind and attaches it to filehandle SOCKET. DOMAIN, TYPE, and PROTOCOL are specified the same as for the syscall of the same name. You should use Socket first to get the proper definitions imported. See the examples in "Sockets: Client/Server Communication" in perlipc.
On systems that support a close-on-exec flag on files, the flag will be set for the newly opened file descriptor, as determined by the value of $^F. See "$^F" in perlvar.