<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation"> <title>getservbyname_r()--Get Port Number for Service Name</title> <!-- 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. --> <!-- Begin Header Records ========================================== --> <!-- Unix8 SCRIPT J converted by B2H R4.1 (346) (CMS) by V2KEA304 --> <!-- at RCHVMW2 on 17 Feb 1999 at 11:05:09 --> <!--End Header Records --> <!-- Edited by Kersten Feb 02 --> <link rel="stylesheet" type="text/css" href="../rzahg/ic.css"> </head> <body> <a name="Top_Of_Page"></a> <!-- Java sync-link --> <script type="text/javascript" language="Javascript" src="../rzahg/synch.js"> </script> <h2>getservbyname_r()--Get Port Number for Service Name</h2> <div class="box" style="width: 60%;"> <br> Syntax<br> <pre> #include <netdb.h> int getservbyname_r(char *<em>service_name</em>, char *<em>protocol_name</em>, struct servent *<em>servent_struct_addr</em>, struct servent_data *<em>servent_data_struct_addr</em>) </pre> <br> Service Program Name: QSOSRV2<br> <!-- iddvc RMBR --> <br> Default Public Authority: *USE<br> <!-- iddvc RMBR --> <br> Threadsafe: Yes<br> <!-- iddvc RMBR --> <br> </div> <p>The <em>getservbyname_r()</em> function is used to retrieve information about services: the protocol being used by the service and the port number assigned for the service. The information is retrieved from the service database file.</p> <h3>Parameters</h3> <dl> <dt>char *<strong>service_name</strong> (input) </dt> <dd>Specifies the pointer to the character string that contains the name of the service for which information is to be retrieved (for example, telnet).<br> <br> </dd> <dt>char *<strong>protocol_name</strong> (input) </dt> <dd>Specifies the pointer to the character string that contains the name of the protocol that further qualifies the search search criteria. For example, if the <em>service_name</em> is telnet, and the <em>protocol_name</em> is tcp, then the call will return the telnet server that uses the TCP protocol. If this parameter is set to NULL, then the first telnet server is returned, regardless of the protocol used.<br> <br> </dd> <dt>struct servent *<strong>servent_struct_addr</strong> (input/output) </dt> <dd>Specifies the pointer to a servent structure where the results will be placed. All results must be referenced through this structure.<br> <br> </dd> <dt>struct servent_data *<strong>servent_data_struct_addr</strong> (input/output) </dt> <dd>Specifies the pointer to the servent_data structure, which is used to pass and preserve results between function calls. The field serve_control_blk in the servent_data structure must be initialized with hexadecimal zeros before its initial use. If compatibility with other platforms is required, then the entire servent_data structure must be initialized with hexadecimal zeros before initial use.</dd> </dl> <br> <h3>Authorities</h3> <p>No authorization is required.</p> <br> <h3>Return Value</h3> <p>The <em>getservbyname_r()</em> function returns an integer. Possible values are:</p> <ul> <li>-1 (unsuccessful call)</li> <li>0 (successful call)</li> </ul> <p>The <strong>struct servent</strong> denoted by <strong><em>servent_struct_addr</em></strong> and <strong>struct servent_data</strong>denoted by <strong><em>servent_data_struct_addr</em></strong> are both defined in <strong><netdb.h></strong>. The structure <strong>struct servent</strong>is defined as:</p> <pre> struct servent [ char *s_name; char **s_aliases; int s_port; char *s_proto ]; </pre> <p><em>s_name</em> points to the character string that contains the name of the service. <em>s_aliases</em> is a pointer to a NULL-terminated list of pointers, each of which points to a character string that represents an alternative name for the service. <em>s_port</em> is the port number assigned to the service. <em>s_proto</em> is a pointer to a character string that contains the name of the protocol being used by the service.</p> <br> <h3>Error Conditions</h3> <p>When the <em>getservbyname_r()</em> function fails, <em>errno</em> can be set to:</p> <dl> <dt><em>[EINVAL]</em></dt> <dd><p>?The servent_data structure was not properly initialized with hexadecimal zeros before initial use. For corrective action, see the description for structure servent_data.</p></dd> </dl> <br> <h3>Usage Notes</h3> <ol> <li>The iSeries Navigator or the following CL commands can be used to access the services database file:<br> <br> <ul> <li>WRKSRVTBLE (Work with Service Table Entries)</li> <li>ADDSRVTBLE (Add Service Table Entry)</li> <li>RMVSRVTBLE (Remove Service Table Entry)</li> </ul> <br> </li> <li>When the service information is obtained from the service database file, the file is opened and the service information is retrieved (if it exists) from the file. The file is then closed only if a <em>setservent_r()</em> call with a non-zero parameter value was not previously done.<br> <br> </li> <li>A coded character set identifier (CCSID) of 65535 for the job requests that no database translation be performed. For translation to occur for the following, the job CCSID must be something other than 65535:<br> <br> <ul> <li>The service name and the protocol name, specified by the <em>service_name</em> and <em>protocol_name</em> parameters, respectively</li> <li>The service names returned in the servent structure</li> </ul> </li> </ol> <br> <h3>Related Information</h3> <ul> <li><a href="tsgservp.htm">getservbyport_r()</a>--Get Service Name for Port Number<br> <br> </li> <li><a href="tsgserve.htm">getservent_r()</a>--Get Next Entry from Service Database<br> <br> </li> <li><a href="tssserve.htm">setservent_r()</a>--Open Service Database<br> <br> </li> <li><a href="tseserve.htm">endservent_r()</a>--Close Service Database</li> </ul> <br> <hr> API introduced: V3R1 <hr> <center> <table cellpadding="2" cellspacing="2"> <tr align="center"> <td valign="middle" align="center"><a href="#Top_Of_Page">Top</a> | <a href= "unix.htm">UNIX-Type APIs</a> | <a href="aplist.htm">APIs by category</a> </td> </tr> </table> </center> </body> </html>