mirror of
https://git.proxmox.com/git/systemd
synced 2026-02-03 16:13:04 +00:00
56 lines
6.0 KiB
HTML
56 lines
6.0 KiB
HTML
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>sd_bus_message_get_cookie</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><style>
|
||
a.headerlink {
|
||
color: #c60f0f;
|
||
font-size: 0.8em;
|
||
padding: 0 4px 0 4px;
|
||
text-decoration: none;
|
||
visibility: hidden;
|
||
}
|
||
|
||
a.headerlink:hover {
|
||
background-color: #c60f0f;
|
||
color: white;
|
||
}
|
||
|
||
h1:hover > a.headerlink, h2:hover > a.headerlink, h3:hover > a.headerlink, dt:hover > a.headerlink {
|
||
visibility: visible;
|
||
}
|
||
</style><a href="index.html">Index </a>·
|
||
<a href="systemd.directives.html">Directives </a>·
|
||
<a href="../python-systemd/index.html">Python </a>·
|
||
<a href="../libudev/index.html">libudev </a>·
|
||
<a href="../libudev/index.html">gudev </a><span style="float:right">systemd 214</span><hr><div class="refentry"><a name="sd_bus_message_get_cookie"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>sd_bus_message_get_cookie, sd_bus_message_get_reply_cookie — Returns the transaction cookie of a message</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><pre class="funcsynopsisinfo">#include <systemd/sd-bus.h></pre><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">sd_bus_message_get_cookie</b>(</code></td><td>sd_bus_message *<var class="pdparam">message</var>, </td></tr><tr><td> </td><td>uint64_t *<var class="pdparam">cookie</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">sd_bus_message_get_reply_cookie</b>(</code></td><td>sd_bus_message *<var class="pdparam">message</var>, </td></tr><tr><td> </td><td>uint64_t *<var class="pdparam">cookie</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="idm214179228944"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p><code class="function">sd_bus_message_get_cookie()</code> returns
|
||
the transaction cookie of a message. The cookie
|
||
uniquely identifies a message within each bus peer,
|
||
but is not globally unique. It is assigned when a
|
||
message is sent.</p><p><code class="function">sd_bus_message_get_reply_cookie()</code>
|
||
returns the transaction cookie of the message the
|
||
specified message is a response to. When a reply
|
||
message is generated for a method call message, its
|
||
cookie is copied over into this field. Note that while
|
||
every message that is transferred is identified by a
|
||
cookie, only response messages carry a reply cookie
|
||
field.</p><p>Both functions take a message object as first
|
||
parameter and a place to store the 64-bit cookie
|
||
in.</p></div><div class="refsect1"><a name="idm214179171968"></a><h2 id="Return Value">Return Value<a class="headerlink" title="Permalink to this headline" href="#Return%20Value">¶</a></h2><p>On success, these calls return 0 or a positive
|
||
integer. On failure, these calls return a negative
|
||
errno-style error code.</p><p>On success, the cookie/reply cookie is returned
|
||
in the specified 64-bit unsigned integer variable.</p></div><div class="refsect1"><a name="idm214179777200"></a><h2 id="Errors">Errors<a class="headerlink" title="Permalink to this headline" href="#Errors">¶</a></h2><p>Returned errors may indicate the following problems:</p><div class="variablelist"><dl class="variablelist"><dt id="-EINVAL"><span class="term"><code class="varname">-EINVAL</code></span><a class="headerlink" title="Permalink to this term" href="#-EINVAL">¶</a></dt><dd><p>A specified parameter
|
||
is invalid.</p></dd><dt id="-ENODATA"><span class="term"><code class="varname">-ENODATA</code></span><a class="headerlink" title="Permalink to this term" href="#-ENODATA">¶</a></dt><dd><p>No cookie has been
|
||
assigned to this message. This either
|
||
indicates that the message has not
|
||
been sent yet and hence has no cookie
|
||
assigned, or that the message is not a
|
||
method response message and hence
|
||
carries a reply cookie
|
||
field.</p></dd></dl></div></div><div class="refsect1"><a name="idm214180026160"></a><h2 id="Notes">Notes<a class="headerlink" title="Permalink to this headline" href="#Notes">¶</a></h2><p>The <code class="function">sd_bus_message_get_cookie()</code>
|
||
and <code class="function">sd_bus_message_get_reply_cookie()</code>
|
||
interfaces are available as a shared library, which can
|
||
be compiled and linked to with the
|
||
<code class="constant">libsystemd</code> <a href="pkg-config.html"><span class="citerefentry"><span class="refentrytitle">pkg-config</span>(1)</span></a>
|
||
file.</p></div><div class="refsect1"><a name="idm214180103824"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
|
||
<a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
|
||
<a href="sd-bus.html"><span class="citerefentry"><span class="refentrytitle">sd-bus</span>(3)</span></a>,
|
||
<a href="sd_bus_new.html"><span class="citerefentry"><span class="refentrytitle">sd_bus_new</span>(3)</span></a>
|
||
</p></div></div></body></html>
|