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<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>sd_bus_message_append_string_memfd</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><style>
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<a href="../libudev/index.html">gudev </a><span style="float:right">systemd 215</span><hr><div class="refentry"><a name="sd_bus_message_append_string_memfd"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>sd_bus_message_append_string_memfd, sd_bus_message_append_string_iovec, sd_bus_message_append_string_space — Attach a string to 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 sd_bus_message_append_string_memfd(</code></td><td>sd_bus_message *<var class="pdparam">m</var>, </td></tr><tr><td> </td><td>sd_memfd *<var class="pdparam">memfd</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 sd_bus_message_append_string_iovec(</code></td><td>sd_bus_message *<var class="pdparam">m</var>, </td></tr><tr><td> </td><td>const struct iovec *<var class="pdparam">iov</var>, </td></tr><tr><td> </td><td>unsigned <var class="pdparam">n</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 sd_bus_message_append_string_space(</code></td><td>sd_bus_message *<var class="pdparam">m</var>, </td></tr><tr><td> </td><td>size_t <var class="pdparam">size</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">s</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="idm214169135024"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p>The functions
<code class="function">sd_bus_message_append_string_memfd</code> and
<code class="function">sd_bus_message_append_string_iovec</code> can be
used to append a single string (item of type "<code class="literal">s</code>")
to message <em class="parameter"><code>m</code></em>.</p><p>In case of
<code class="function">sd_bus_message_append_string_memfd</code>, the
contents of <em class="parameter"><code>memfd</code></em> are the string. They must
satisfy the same constraints as described for the
"<code class="literal">s</code>" type in
<a href="sd_bus_message_append_basic.html"><span class="citerefentry"><span class="refentrytitle">sd_bus_message_append_basic</span>(3)</span></a>.</p><p>In case of
<code class="function">sd_bus_message_append_string_iovec</code>, the
payload of <em class="parameter"><code>iov</code></em> is the string. It must
satisfy the same constraints as described for the
"<code class="literal">s</code>" type in
<a href="sd_bus_message_append_basic.html"><span class="citerefentry"><span class="refentrytitle">sd_bus_message_append_basic</span>(3)</span></a>.</p><p>The <em class="parameter"><code>iov</code></em> argument must point to
<em class="parameter"><code>n</code></em> <span class="structname">struct iovec</span>
structures. Each structure may have the
<span class="structname">iov_base</span> field set, in which case the
memory pointed to will be copied into the message, or unset, in
which case a block of spaces (ASCII 32) of length
<span class="structname">iov_len</span> will be inserted. The
memory pointed at by <em class="parameter"><code>iov</code></em> may be changed
after this call.</p><p>The
<code class="function">sd_bus_message_append_string_space</code> function appends
space for a string to message <em class="parameter"><code>m</code></em>. It behaves
similar to <code class="function">sd_bus_message_append_basic</code> with
type "<code class="literal">s</code>", but instead of copying a string into
the message, it returns a pointer to the destination area to
the caller in pointer <em class="parameter"><code>p</code></em>. Space for the string
of length <em class="parameter"><code>size</code></em> plus the terminating
<code class="constant">NUL</code> is allocated.</p></div><div class="refsect1"><a name="idm214168480256"></a><h2 id="Return Value">Return Value<a class="headerlink" title="Permalink to this headline" href="#Return%20Value">¶</a></h2><p>On success, those calls return 0 or a positive integer. On
failure, they returns a negative errno-style error code.</p></div><div class="refsect1"><a name="errors"></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>Specified parameter is invalid.
</p></dd><dt id="-EPERM"><span class="term"><code class="varname">-EPERM</code></span><a class="headerlink" title="Permalink to this term" href="#-EPERM">¶</a></dt><dd><p>Message has been sealed.
</p></dd><dt id="-ESTALE"><span class="term"><code class="varname">-ESTALE</code></span><a class="headerlink" title="Permalink to this term" href="#-ESTALE">¶</a></dt><dd><p>Message is in invalid state.
</p></dd><dt id="-ENXIO"><span class="term"><code class="varname">-ENXIO</code></span><a class="headerlink" title="Permalink to this term" href="#-ENXIO">¶</a></dt><dd><p>Message cannot be appended to.
</p></dd><dt id="-ENOMEM"><span class="term"><code class="varname">-ENOMEM</code></span><a class="headerlink" title="Permalink to this term" href="#-ENOMEM">¶</a></dt><dd><p>Memory allocation failed.</p></dd></dl></div></div><div class="refsect1"><a name="idm214169750000"></a><h2 id="Notes">Notes<a class="headerlink" title="Permalink to this headline" href="#Notes">¶</a></h2><p>The functions described here 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="idm214167904208"></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_message_append_basic.html"><span class="citerefentry"><span class="refentrytitle">sd_bus_message_append_basic</span>(3)</span></a>,
<a class="ulink" href="http://dbus.freedesktop.org/doc/dbus-specification.html" target="_top">The D-Bus specification</a>
</p></div></div></body></html>
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