man/sd_bus_message_append_string_memfd.html

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  22   <span style="float:right">systemd 221</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 &lt;systemd/sd-bus.h&gt;</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>int <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="idm47933616430416"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p>The functions
  23     <code class="function">sd_bus_message_append_string_memfd</code> and
  24     <code class="function">sd_bus_message_append_string_iovec</code> can be
  25     used to append a single string (item of type "<code class="literal">s</code>")
  26     to message <em class="parameter"><code>m</code></em>.</p><p>In case of
  27     <code class="function">sd_bus_message_append_string_memfd</code>, the
  28     contents of <em class="parameter"><code>memfd</code></em> are the string. They must
  29     satisfy the same constraints as described for the
  30     "<code class="literal">s</code>" type in
  31     <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
  32     <code class="function">sd_bus_message_append_string_iovec</code>, the
  33     payload of <em class="parameter"><code>iov</code></em> is the string. It must
  34     satisfy the same constraints as described for the
  35     "<code class="literal">s</code>" type in
  36     <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
  37     <em class="parameter"><code>n</code></em> <span class="structname">struct iovec</span>
  38     structures. Each structure may have the
  39     <span class="structname">iov_base</span> field set, in which case the
  40     memory pointed to will be copied into the message, or unset, in
  41     which case a block of spaces (ASCII 32) of length
  42     <span class="structname">iov_len</span> will be inserted. The
  43     memory pointed at by <em class="parameter"><code>iov</code></em> may be changed
  44     after this call.</p><p>The
  45     <code class="function">sd_bus_message_append_string_space</code> function appends
  46     space for a string to message <em class="parameter"><code>m</code></em>. It behaves
  47     similar to <code class="function">sd_bus_message_append_basic</code> with
  48     type "<code class="literal">s</code>", but instead of copying a string into
  49     the message, it returns a pointer to the destination area to
  50     the caller in pointer <em class="parameter"><code>p</code></em>. Space for the string
  51     of length <em class="parameter"><code>size</code></em> plus the terminating
  52     <code class="constant">NUL</code> is allocated.</p></div><div class="refsect1"><a name="idm47933616412384"></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
  53     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="constant">-EINVAL</code></span><a class="headerlink" title="Permalink to this term" href="#-EINVAL">¶</a></dt><dd><p>Specified parameter is invalid.
  54         </p></dd><dt id="-EPERM"><span class="term"><code class="constant">-EPERM</code></span><a class="headerlink" title="Permalink to this term" href="#-EPERM">¶</a></dt><dd><p>Message has been sealed.
  55         </p></dd><dt id="-ESTALE"><span class="term"><code class="constant">-ESTALE</code></span><a class="headerlink" title="Permalink to this term" href="#-ESTALE">¶</a></dt><dd><p>Message is in invalid state.
  56         </p></dd><dt id="-ENXIO"><span class="term"><code class="constant">-ENXIO</code></span><a class="headerlink" title="Permalink to this term" href="#-ENXIO">¶</a></dt><dd><p>Message cannot be appended to.
  57         </p></dd><dt id="-ENOMEM"><span class="term"><code class="constant">-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="idm47933616410368"></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,
  58     which can be compiled and linked to with the
  59     <code class="constant">libsystemd</code> <a href="http://linux.die.net/man/1/pkg-config"><span class="citerefentry"><span class="refentrytitle">pkg-config</span>(1)</span></a>
  60     file.</p></div><div class="refsect1"><a name="idm47933616407696"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
  61       <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
  62       <a href="sd-bus.html"><span class="citerefentry"><span class="refentrytitle">sd-bus</span>(3)</span></a>,
  63       <a href="sd_bus_message_append_basic.html"><span class="citerefentry"><span class="refentrytitle">sd_bus_message_append_basic</span>(3)</span></a>,
  64       <a class="ulink" href="http://dbus.freedesktop.org/doc/dbus-specification.html" target="_top">The D-Bus specification</a>
  65     </p></div></div></body></html>