267 lines
6.5 KiB
HTML
267 lines
6.5 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<html>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation">
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<title>gethostname()--Retrieve Host Name</title>
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<a name="Top_Of_Page"></a>
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<h2>gethostname()--Retrieve Host Name</h2>
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<div class="box" style="width: 70%;">
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<br>
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BSD 4.3 Syntax<br>
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<pre>
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#include <sys/types.h>
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#include <sys/socket.h>
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int gethostname(char *<em>name</em>,
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int <em>length</em>)
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</pre>
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<br>
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Service Program Name: QSOSRV1<br>
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<!-- iddvc RMBR -->
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<br>
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Default Public Authority: *USE<br>
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<!-- iddvc RMBR -->
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<br>
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Threadsafe: Yes<br>
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<br>
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</div>
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<br>
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<div class="box" style="width: 70%;">
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<br>
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<a href="_xopen_source.htm">UNIX 98 Compatible Syntax</a><br>
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<pre>
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#define _XOPEN_SOURCE 520
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#include <sys/socket.h>
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int gethostname(char *<em>name</em>,
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socklen_t <em>length</em>)
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</pre>
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<br>
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Service Program Name: QSOSRV1<br>
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<!-- iddvc RMBR -->
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<br>
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Default Public Authority: *USE<br>
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<!-- iddvc RMBR -->
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<br>
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Threadsafe: Yes<br>
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<!-- iddvc RMBR -->
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<br>
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</div>
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<br>
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<p>The <em>gethostname()</em> function is used to retrieve the name of the host
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from the system.</p>
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<p> There are two versions of
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the API, as shown above. The base i5/OS API uses BSD 4.3 structures and
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syntax. The other uses syntax and structures compatible with the UNIX 98
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programming interface specifications. You can select the UNIX 98 compatible
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interface with the <a href="_xopen_source.htm">_XOPEN_SOURCE</a> macro.</p>
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<br>
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<h3>Parameters</h3>
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<dl>
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<dt><strong>name</strong></dt>
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<dd>(Output) The pointer to a character array where the host name is to be
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stored. The host name is NULL-terminated unless the length of the host name
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exceeds the length of the <em>name</em> parameter, in which case the host name
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is truncated to the size of the <em>name</em> parameter.<br>
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<br>
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</dd>
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<dt><strong>length</strong></dt>
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<dd>(Input) The length of the <em>name</em> parameter.</dd>
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</dl>
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<br>
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<h3>Authorities</h3>
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<p>No authorization is required.</p>
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<br>
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<h3>Return Value</h3>
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<p><em>gethostname()</em> returns an integer. Possible values are:</p>
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<ul>
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<li>-1 (unsuccessful)<br>
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<br>
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</li>
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<li>0 (successful)</li>
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</ul>
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<br>
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<h3>Error Conditions</h3>
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<p>When <em>gethostname()</em> fails, <em>errno</em> can be set to one of the
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following:</p>
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<table cellpadding="5">
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<!-- cols="15 85" -->
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<tr>
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<td align="left" valign="top"><em>[EFAULT]</em></td>
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<td align="left" valign="top">Bad address.
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<p>The system detected an address which was not valid while attempting to
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access the <em>name</em> parameter.</p>
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</td>
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</tr>
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<tr>
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<td align="left" valign="top"><em>[EINVAL]</em></td>
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<td align="left" valign="top">Parameter not valid.
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<p>The <em>length</em> parameter specifies a negative value.</p>
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</td>
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</tr>
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<tr>
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<td align="left" valign="top"><em>[EIO]</em></td>
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<td align="left" valign="top">Input/output error.</td>
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</tr>
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<tr>
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<td align="left" valign="top"><em>[EUNKNOWN]</em></td>
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<td align="left" valign="top">Unknown system state.</td>
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</tr>
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</table>
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<br>
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<br>
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<h3>Error Messages</h3>
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<table width="100%" cellpadding="5">
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<!-- cols="15 85" -->
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<tr>
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<th align="left" valign="top">Message ID</th>
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<th align="left" valign="top">Error Message Text</th>
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</tr>
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<tr>
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<td width="15%" valign="top">CPE3418 E</td>
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<td width="85%" valign="top">Possible APAR condition or hardware failure.</td>
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</tr>
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<tr>
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<td align="left" valign="top">CPF9872 E</td>
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<td align="left" valign="top">Program or service program &1 in library
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&2 ended. Reason code &3.</td>
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</tr>
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<tr>
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<td align="left" valign="top">CPFA081 E</td>
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<td align="left" valign="top">Unable to set return value or error code.</td>
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</tr>
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</table>
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<br>
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<br>
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<h3>Usage Notes</h3>
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<ol>
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<li>Maximum length of host names is defined by {MAXHOSTNAMELEN} (defined in
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<strong><sys/param.h></strong>).<br>
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<br>
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</li>
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<li>When a process issues a <em>sethostname()</em>, the host name can be
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accessed by any process that issues a <em>gethostname()</em>.<br>
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<br>
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</li>
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<li>On an initial program load, the host name is set to whatever was configured
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using the iSeries Navigator or
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option 12 (Change TCP/IP
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domain information) on the Configure TCP/IP (CFGTCP) menu. The local domain
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name is appended with the local host name and stored in system-wide storage.
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This combined name is the host name that can be retrieved by
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<em>gethostname()</em>. If the local host name and local domain name are not
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set, the host name is set to NULL.<br>
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<br>
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</li>
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<li>The host name is returned in the default coded character set identifier
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(CCSID) currently in effect for the job.<br>
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<br>
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</li>
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<li>When you develop in C-based
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languages and an application is compiled with the _XOPEN_SOURCE macro defined
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to the value 520 or greater, the <em>gethostname()</em> API is mapped to
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<em>qso_gethostname98()</em>.</li>
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</ol>
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<br>
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<h3>Related Information</h3>
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<ul>
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<li><a href="_xopen_source.htm">_XOPEN_SOURCE</a>--Using _XOPEN_SOURCE for the UNIX 98
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compatible interface<br>
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<br>
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</li>
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<li><a href="shostn.htm">sethostname()</a>--Set Host Name<br>
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<br>
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</li>
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<li><a href="ghosti.htm">gethostid()</a>--Retrieve Host ID Address<br>
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<br>
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</li>
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<li><a href="shosti.htm">sethostid()</a>--Set Host ID Address</li>
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</ul>
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<br>
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<hr>
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API introduced: V3R1
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<hr>
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<center>
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<table cellpadding="2" cellspacing="2">
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<tr align="center">
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<td valign="middle" align="center"><a href="#Top_Of_Page">Top</a> | <a href=
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"unix.htm">UNIX-Type APIs</a> | <a href="aplist.htm">APIs by category</a></td>
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</tr>
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</table></center>
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</body>
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</html>
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