Re: How to tell if a socket is connected

Adam Zey wrote: > Michael W. wrote: >> Hello, >> Can any of you tell me how to tell whether a socket (from fsockopen()) >> is >> connected or not? Specifically, whether the remote server has closed the >> connection? Stream_get_meta_data() does not do it; in my tests, its >> output does not change even when the server closes the stream. >> >> Thank you, >> Michael W. > > If it is a network socket, and the remote end disconnected unexpectedly > (which you MUST assume is a possibility), then the only way to find out > if the connection is still open is by SENDING data. Just trying to read > it won't cut it. > > The thing to understand is that when a remote client/server disconnects, > it normally safely closes the socket and notifies you. But an abrupt > disconnection (Something crashes, loses connectivity, etc) sends no such > thing. The only way to find out that a connection is really lost is to > write some data and see if it times out or not. > > Regards, Adam Zey. How can I tell whether the write timed out? Does fwrite() return false, or do I have to check for the 'timed_out' flag in the return of stream_get_meta_data()? Thanks a lot, Michael W.