HP Rp7410 BSD Sockets Interface Programmer's Guide - Page 53

len += len1

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Using Internet Stream Sockets Example Using Internet Stream Sockets exit(1); } /* Go into a loop, receiving requests from the * remote client. After the client has sent the * last request, it will do a shutdown for sending, * which causes an end-of-file condition to appear * on this end of the connection. After all of the * client's requests have been received, the next * recv call will return zero bytes, signalling an * end-of-file condition. This is is how the server * will know that no more requests will follow * and the loop will be exited.*/ while (len = recv(s, buf, 10, 0)) { if (len == -1) goto errout; /* error from recv */ /* 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 beginning * of the next request. */ while (len < 10) { len1 = recv(s, &buf[len], 10-len, 0); if (len1 == -1) goto errout; len += len1; } /* Increment the request count. */ reqcnt++; /* This sleep simulates the processing of * the request that a real server might do. */ sleep(1); /* Send a response back to the client. */ if (send(s, buf, 10, 0) != 10) goto errout; } /* The loop has terminated, because there are no * more requests to be serviced. As above, this * close will block until all of the sent replies * have been received by the remote host. Lingering * on the close is so the server will have a better * idea when the remote has picked up all the data. * This allows the start and finish times printed * in the log file to more accurately reflect * the length of time this connection was used. */ close(s); /* Log a finishing message. */ time (&timevar); Chapter 2 53

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Chapter 2
53
Using Internet Stream Sockets
Example Using Internet Stream Sockets
exit(1);
}
/* Go into a loop, receiving requests from the
* remote client.
After the client has sent the
* last request, it will do a shutdown for sending,
* which causes an end-of-file condition to appear
* on this end of the connection.
After all of the
* client’s requests have been received, the next
* recv call will return zero bytes, signalling an
* end-of-file condition. This is is how the server
* will know that no more requests will follow
* and the loop will be exited.*/
while (len = recv(s, buf, 10, 0)) {
if (len == -1) goto errout; /* error from recv */
/* 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 beginning
* of the next request.
*/
while (len < 10) {
len1 = recv(s, &buf[len], 10-len, 0);
if (len1 == -1) goto errout;
len += len1;
}
/* Increment the request count. */
reqcnt++;
/* This sleep simulates the processing of
* the request that a real server might do.
*/
sleep(1);
/* Send a response back to the client. */
if (send(s, buf, 10, 0) != 10) goto errout;
}
/* The loop has terminated, because there are no
* more requests to be serviced. As above, this
* close will block until all of the sent replies
* have been received by the remote host. Lingering
* on the close is so the server will have a better
* idea when the remote has picked up all the data.
* This allows the start and finish times printed
* in the log file to more accurately reflect
* the length of time this connection was used.
*/
close(s);
/* Log a finishing message. */
time (&timevar);