files on unix are referenced counted. and unix sockets are just a type of file. every link adds to the count, a link can be a filesystem name but open file hand

files on unix are referenced counted. and unix sockets are just a type of file. every link adds to the count, a link can be a filesystem name but open file handles are also links. once there are no more links to a file the file can be deleted. so this is opening a unix socket with a no name(the initial null terminates the C style string) thus leaving the only link to it as the file discripter. One trick I used to do was to sneak another link to the file to keep it around before the process ended , The serious real use case for this was if you had accidentally deleted a file but some process was keeping it open somewhere, but I mainly used it back when youtube was flash based it would try and keep the video cache file hidden this way. and you could make a copy of the video by snaging the correct file descriptor.