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<center><font size="2">The Open Group Base Specifications Issue 6<br>
IEEE Std 1003.1-2001<br>
Copyright &copy; 2001 The IEEE and The Open Group, All Rights reserved.</font></center>
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<h4><a name="tag_03_265_01"></a>NAME</h4>
<blockquote>htonl, htons, ntohl, ntohs - convert values between host and network byte order</blockquote>
<h4><a name="tag_03_265_02"></a>SYNOPSIS</h4>
<blockquote class="synopsis">
<p><code><tt>#include &lt;<a href="../basedefs/arpa/inet.h.html">arpa/inet.h</a>&gt;<br>
<br>
uint32_t htonl(uint32_t</tt> <i>hostlong</i><tt>);<br>
uint16_t htons(uint16_t</tt> <i>hostshort</i><tt>);<br>
uint32_t ntohl(uint32_t</tt> <i>netlong</i><tt>);<br>
uint16_t ntohs(uint16_t</tt> <i>netshort</i><tt>);<br>
</tt></code></p>
</blockquote>
<h4><a name="tag_03_265_03"></a>DESCRIPTION</h4>
<blockquote>
<p>These functions shall convert 16-bit and 32-bit quantities between network byte order and host byte order.</p>
<p>On some implementations, these functions are defined as macros.</p>
<p>The <b>uint32_t</b> and <b>uint16_t</b> types are defined in <a href=
"../basedefs/inttypes.h.html"><i>&lt;inttypes.h&gt;</i></a>.</p>
</blockquote>
<h4><a name="tag_03_265_04"></a>RETURN VALUE</h4>
<blockquote>
<p>The <i>htonl</i>() and <i>htons</i>() functions shall return the argument value converted from host to network byte order.</p>
<p>The <i>ntohl</i>() and <i>ntohs</i>() functions shall return the argument value converted from network to host byte order.</p>
</blockquote>
<h4><a name="tag_03_265_05"></a>ERRORS</h4>
<blockquote>
<p>No errors are defined.</p>
</blockquote>
<hr>
<div class="box"><em>The following sections are informative.</em></div>
<h4><a name="tag_03_265_06"></a>EXAMPLES</h4>
<blockquote>
<p>None.</p>
</blockquote>
<h4><a name="tag_03_265_07"></a>APPLICATION USAGE</h4>
<blockquote>
<p>These functions are most often used in conjunction with IPv4 addresses and ports as returned by <a href=
"../functions/gethostent.html"><i>gethostent</i>()</a> and <a href="../functions/getservent.html"><i>getservent</i>()</a>.</p>
</blockquote>
<h4><a name="tag_03_265_08"></a>RATIONALE</h4>
<blockquote>
<p>None.</p>
</blockquote>
<h4><a name="tag_03_265_09"></a>FUTURE DIRECTIONS</h4>
<blockquote>
<p>None.</p>
</blockquote>
<h4><a name="tag_03_265_10"></a>SEE ALSO</h4>
<blockquote>
<p><a href="endhostent.html"><i>endhostent</i>()</a> , <a href="endservent.html"><i>endservent</i>()</a> , the Base Definitions
volume of IEEE&nbsp;Std&nbsp;1003.1-2001, <a href="../basedefs/inttypes.h.html"><i>&lt;inttypes.h&gt;</i></a>, <a href=
"../basedefs/arpa/inet.h.html"><i>&lt;arpa/inet.h&gt;</i></a></p>
</blockquote>
<h4><a name="tag_03_265_11"></a>CHANGE HISTORY</h4>
<blockquote>
<p>First released in Issue 6. Derived from the XNS, Issue 5.2 specification.</p>
</blockquote>
<div class="box"><em>End of informative text.</em></div>
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