<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html lang="en-us" xml:lang="en-us"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="security" content="public" /> <meta name="Robots" content="index,follow" /> <meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' /> <meta name="DC.Type" content="reference" /> <meta name="DC.Title" content="Example: Generic client" /> <meta name="abstract" content="This code example contains the code for a common client job." /> <meta name="description" content="This code example contains the code for a common client job." /> <meta name="DC.Relation" scheme="URI" content="xcodesigns.htm" /> <meta name="DC.Relation" scheme="URI" content="xip6client.htm" /> <meta name="DC.Relation" scheme="URI" content="xcodesigns.htm" /> <meta name="DC.Relation" scheme="URI" content="xiterative.htm" /> <meta name="DC.Relation" scheme="URI" content="xdescriptors.htm" /> <meta name="DC.Relation" scheme="URI" content="x1descriptors.htm" /> <meta name="DC.Relation" scheme="URI" content="xmultiaccept.htm" /> <meta name="DC.Relation" scheme="URI" content="x1mulitaccept.htm" /> <meta name="DC.Relation" scheme="URI" content="../apis/socket.htm" /> <meta name="DC.Relation" scheme="URI" content="../apis/connec.htm" /> <meta name="DC.Relation" scheme="URI" content="../apis/close.htm" /> <meta name="DC.Relation" scheme="URI" content="../apis/send.htm" /> <meta name="DC.Relation" scheme="URI" content="../apis/recv.htm" /> <meta name="DC.Relation" scheme="URI" content="xasynchi0.htm" /> <meta name="DC.Relation" scheme="URI" content="xnonblock.htm" /> <meta name="copyright" content="(C) Copyright IBM Corporation 2001, 2006" /> <meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2001, 2006" /> <meta name="DC.Format" content="XHTML" /> <meta name="DC.Identifier" content="generic" /> <meta name="DC.Language" content="en-us" /> <!-- All rights reserved. Licensed Materials Property of IBM --> <!-- US Government Users Restricted Rights --> <!-- Use, duplication or disclosure restricted by --> <!-- GSA ADP Schedule Contract with IBM Corp. --> <link rel="stylesheet" type="text/css" href="./ibmdita.css" /> <link rel="stylesheet" type="text/css" href="./ic.css" /> <title>Example: Generic client</title> </head> <body id="generic"><a name="generic"><!-- --></a> <!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script> <h1 class="topictitle1">Example: Generic client</h1> <div><p>This code example contains the code for a common client job.</p> <div class="section"><p>The client job does a <span class="apiname">socket()</span>, <span class="apiname">connect()</span>, <span class="apiname">send()</span>, <span class="apiname">recv()</span>, and <span class="apiname">close()</span> operation. The client job is not aware that the data buffer it sent and received is going to a worker job rather than the server. If you want to create a client application that works whether the server uses the AF_INET address family or AF_INET6 address family, use the IPv4 or IPv6 client example.</p> </div> <div class="section"><p>This client job works with each of these common connection-oriented server designs:</p> </div> <div class="section"><ul><li>An iterative server. See <a href="xiterative.htm#xiterative">Example: Write an iterative server program</a> for a sample program.</li> <li>A spawn server and worker. See <a href="xspawn.htm#xspawn">Example: Use the spawn() API to create child processes</a> for a sample program.</li> <li>A sendmsg() server and rcvmsg() worker. See <a href="x1descriptors.htm#x1descriptors">Example: Server program used for sendmsg() and recvmsg()</a> for a sample program.</li> <li>A multiple accept() design. See <a href="x1mulitaccept.htm#x1mulitaccept">Example: Server program to create a pool of multiple accept() worker jobs </a> for a sample program.</li> <li>A nonblocking I/O and select() design. See <a href="xnonblock.htm#xnonblock">Example: Nonblocking I/O and select()</a> for a sample program.</li> <li>A server that accepts connections from either an IPv4 or IPv6 client.. See <a href="xacceptboth.htm#xacceptboth">Example: Accept connections from both IPv6 and IPv4 clients</a> for a sample program.</li> </ul> </div> <div class="section"><h4 class="sectiontitle">Socket flow of events: Generic client</h4><p>The following sample program uses the following sequence of function calls: </p> <ol><li>The <span class="apiname">socket()</span> function returns a socket descriptor representing an endpoint. The statement also identifies that the INET (Internet Protocol) address family with the TCP transport (SOCK_STREAM) being used for this socket.</li> <li>After the socket descriptor is received, the <span class="apiname">connect()</span> function is used to establish a connection to the server.</li> <li>The <span class="apiname">send() </span> function sends data buffer to the worker job(s). </li> <li>The <span class="apiname">recv()</span> function receives data buffer from the worker job(s).</li> <li> The <span class="apiname">close()</span> function closes any open socket descriptors.</li> </ol> </div> <div class="section"><div class="note"><span class="notetitle">Note:</span> By using the code examples, you agree to the terms of the <a href="codedisclaimer.htm">Code license and disclaimer information</a>.</div> <pre>/**************************************************************************/ /* Generic client example is used with connection-oriented server designs */ /**************************************************************************/ #include <stdio.h> #include <stdlib.h> #include <sys/socket.h> #include <netinet/in.h> #define SERVER_PORT 12345 main (int argc, char *argv[]) { int len, rc; int sockfd; char send_buf[80]; char recv_buf[80]; struct sockaddr_in addr; /*************************************************/ /* Create an AF_INET stream socket */ /*************************************************/ sockfd = socket(AF_INET, SOCK_STREAM, 0); if (sockfd < 0) { perror("socket"); exit(-1); } /*************************************************/ /* Initialize the socket address structure */ /*************************************************/ memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_addr.s_addr = htonl(INADDR_ANY); addr.sin_port = htons(SERVER_PORT); /*************************************************/ /* Connect to the server */ /*************************************************/ rc = connect(sockfd, (struct sockaddr *)&addr, sizeof(struct sockaddr_in)); if (rc < 0) { perror("connect"); close(sockfd); exit(-1); } printf("Connect completed.\n"); /*************************************************/ /* Enter data buffer that is to be sent */ /*************************************************/ printf("Enter message to be sent:\n"); gets(send_buf); /*************************************************/ /* Send data buffer to the worker job */ /*************************************************/ len = send(sockfd, send_buf, strlen(send_buf) + 1, 0); if (len != strlen(send_buf) + 1) { perror("send"); close(sockfd); exit(-1); } printf("%d bytes sent\n", len); /*************************************************/ /* Receive data buffer from the worker job */ /*************************************************/ len = recv(sockfd, recv_buf, sizeof(recv_buf), 0); if (len != strlen(send_buf) + 1) { perror("recv"); close(sockfd); exit(-1); } printf("%d bytes received\n", len); /*************************************************/ /* Close down the socket */ /*************************************************/ close(sockfd); }</pre> </div> </div> <div> <div class="familylinks"> <div class="parentlink"><strong>Parent topic:</strong> <a href="xcodesigns.htm" title="There are a number of ways that you can design a connection-oriented socket server on the iSeries. These example programs can be used to create your own connection-oriented designs.">Examples: Connection-oriented designs</a></div> </div> <div class="relref"><strong>Related reference</strong><br /> <div><a href="xip6client.htm" title="This sample program can be used with the server application that accepts requests from either IPv4 or IPv6 clients.">Example: IPv4 or IPv6 client</a></div> <div><a href="xcodesigns.htm" title="There are a number of ways that you can design a connection-oriented socket server on the iSeries. These example programs can be used to create your own connection-oriented designs.">Examples: Connection-oriented designs</a></div> <div><a href="xiterative.htm" title="Use this example to create a single server job that handles all incoming connections. When the accept() API is completed, the server handles the entire transaction.">Example: Write an iterative server program</a></div> <div><a href="xdescriptors.htm" title="The sendmsg() and recvmsg() examples show how to design a server program that uses these APIs to handle incoming connections.">Example: Pass descriptors between processes</a></div> <div><a href="x1descriptors.htm" title="This example shows how to use the sendmsg() API to create a pool of worker jobs.">Example: Server program used for sendmsg() and recvmsg()</a></div> <div><a href="xmultiaccept.htm" title="These examples show how to design a server program that uses the multiple accept() model for handling incoming connection requests.">Examples: Use multiple accept() APIs to handle incoming requests</a></div> <div><a href="x1mulitaccept.htm" title="This example shows how to use the multiple accept() model to create a pool of worker jobs.">Example: Server program to create a pool of multiple accept() worker jobs</a></div> <div><a href="xasynchi0.htm" title="An application creates an I/O completion port using the QsoCreateIOCompletionPort() API.">Example: Use asynchronous I/O</a></div> <div><a href="xnonblock.htm" title="This sample program uses nonblocking and the select() API.">Example: Nonblocking I/O and select()</a></div> </div> <div class="relinfo"><strong>Related information</strong><br /> <div><a href="../apis/socket.htm">socket()</a></div> <div><a href="../apis/connec.htm">connect()</a></div> <div><a href="../apis/close.htm">close()</a></div> <div><a href="../apis/send.htm">send()</a></div> <div><a href="../apis/recv.htm">recv()</a></div> </div> </div> </body> </html>