php_stream_sock_open_unix() attempts to open the Unix domain socket specified by path. pathlen specifies the length of path. If timeout is not NULL, it specifies a timeout period for the connection attempt. persistent indicates if the stream should be opened as a persistent stream. Generally speaking, this parameter will usually be 0.
Note: This function will not work under Windows, which does not implement Unix domain sockets. A possible exception to this rule is if your PHP binary was built using cygwin. You are encouraged to consider this aspect of the portability of your extension before it's release.
Note: This function treats path in a binary safe manner, suitable for use on systems with an abstract namespace (such as Linux), where the first character of path is a NUL character.