HP Rp7410 BSD Sockets Interface Programmer's Guide - Page 57

Using Internet Stream Sockets Example Using Internet Stream Sockets if (shutdown(s, 1) == -1) { perror(argv[0]); fprintf(stderr, "%s: unable to shutdown socket\n",argv[0]); exit(1); } /* Start receiving all the replys from the server. * This loop will terminate when the recv returns * zero, which is an end-of-file condition. This * will happen after the server has sent all of its * replies, and closed its end of the connection. */ while (i = recv(s, buf, 10, 0)) { if (i == -1) { errout: perror(argv[0]); fprintf(stderr, "%s: error reading result\n",argv[0]); exit(1); } /* The reason this while loop exists is that there * is a remote possibility of the above recv returning * less than 10 bytes. This is because a recv returns * as soon as there is some data, and will not wait for * all of the requested data to arrive. Since 10 bytes * is relatively small compared to the allowed TCP * packet sizes, a partial receive is unlikely. If * this example had used 2048 bytes requests instead, * a partial receive would be far more likely. * This loop will keep receiving until all 10 bytes * have been received, thus guaranteeing that the * next recv at the top of the loop will * start at the begining of the next reply. */ while (i < 10) { j = recv(s, &buf[i], 10-i, 0); if (j == -1) goto errout; i += j; } /* Print out message indicating the * identity of this reply. */ printf("Received result number %d\n", *(int *)buf); } /* Print message indicating completion of task. */ time(&timevar); printf("All done at %s", ctime(&timevar)); } Chapter 2 57