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GNU Info (libc.info)Datagram ExampleDatagram Socket Example ----------------------- Here is a set of example programs that send messages over a datagram stream in the local namespace. Both the client and server programs use the `make_named_socket' function that was presented in Note: Local Socket Example, to create and name their sockets. First, here is the server program. It sits in a loop waiting for messages to arrive, bouncing each message back to the sender. Obviously this isn't a particularly useful program, but it does show the general ideas involved. #include <stdio.h> #include <errno.h> #include <stdlib.h> #include <sys/socket.h> #include <sys/un.h> #define SERVER "/tmp/serversocket" #define MAXMSG 512 int main (void) { int sock; char message[MAXMSG]; struct sockaddr_un name; size_t size; int nbytes; /* Remove the filename first, it's ok if the call fails */ unlink (SERVER); /* Make the socket, then loop endlessly. */ sock = make_named_socket (SERVER); while (1) { /* Wait for a datagram. */ size = sizeof (name); nbytes = recvfrom (sock, message, MAXMSG, 0, (struct sockaddr *) & name, &size); if (nbytes < 0) { perror ("recfrom (server)"); exit (EXIT_FAILURE); } /* Give a diagnostic message. */ fprintf (stderr, "Server: got message: %s\n", message); /* Bounce the message back to the sender. */ nbytes = sendto (sock, message, nbytes, 0, (struct sockaddr *) & name, size); if (nbytes < 0) { perror ("sendto (server)"); exit (EXIT_FAILURE); } } } automatically generated by info2www version 1.2.2.9 |