man/SD_NOTICE.html

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  22   <a href="../libudev/index.html">gudev </a><span style="float:right">systemd 214</span><hr><div class="refentry"><a name="sd-daemon"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>sd-daemon, SD_EMERG, SD_ALERT, SD_CRIT, SD_ERR, SD_WARNING, SD_NOTICE, SD_INFO, SD_DEBUG — APIs for
  23                 new-style daemons</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><pre class="funcsynopsisinfo">#include &lt;systemd/sd-daemon.h&gt;</pre></div><div class="cmdsynopsis"><p><code class="command">pkg-config --cflags --libs libsystemd</code> </p></div></div><div class="refsect1"><a name="idm214188016064"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p><code class="filename">sd-daemon.h</code> provide APIs
  24                 for new-style daemons, as implemented by the
  25                 <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>
  26                 init system.</p><p>See
  27                 <a href="sd_listen_fds.html"><span class="citerefentry"><span class="refentrytitle">sd_listen_fds</span>(3)</span></a>,
  28                 <a href="sd_notify.html"><span class="citerefentry"><span class="refentrytitle">sd_notify</span>(3)</span></a>,
  29                 <a href="sd_booted.html"><span class="citerefentry"><span class="refentrytitle">sd_booted</span>(3)</span></a>,
  30                 <a href="sd_is_fifo.html"><span class="citerefentry"><span class="refentrytitle">sd_is_fifo</span>(3)</span></a>,
  31                 <a href="sd_watchdog_enabled.html"><span class="citerefentry"><span class="refentrytitle">sd_watchdog_enabled</span>(3)</span></a>
  32                 for more information about the functions
  33                 implemented. In addition to these functions, a couple
  34                 of logging prefixes are defined as macros:</p><pre class="programlisting">#define SD_EMERG   "&lt;0&gt;"  /* system is unusable */
  35 #define SD_ALERT   "&lt;1&gt;"  /* action must be taken immediately */
  36 #define SD_CRIT    "&lt;2&gt;"  /* critical conditions */
  37 #define SD_ERR     "&lt;3&gt;"  /* error conditions */
  38 #define SD_WARNING "&lt;4&gt;"  /* warning conditions */
  39 #define SD_NOTICE  "&lt;5&gt;"  /* normal but significant condition */
  40 #define SD_INFO    "&lt;6&gt;"  /* informational */
  41 #define SD_DEBUG   "&lt;7&gt;"  /* debug-level messages */</pre><p>These prefixes are intended to be used in
  42                 conjunction with stderr-based logging as implemented
  43                 by systemd. If a systemd service definition file is
  44                 configured with <code class="varname">StandardError=syslog</code>
  45                 or <code class="varname">StandardError=kmsg</code>, these
  46                 prefixes can be used to encode a log level in lines
  47                 printed. This is similar to the kernel
  48                 <code class="function">printk()</code>-style logging. See
  49                 <a href="klogctl.html"><span class="citerefentry"><span class="refentrytitle">klogctl</span>(2)</span></a>
  50                 for more information.</p><p>The log levels are identical to
  51                 <a href="syslog.html"><span class="citerefentry"><span class="refentrytitle">syslog</span>(3)</span></a>'s
  52                 log level system. To use these prefixes simply prefix
  53                 every line with one of these strings. A line that is
  54                 not prefixed will be logged at the default log level
  55                 SD_INFO.</p><div class="example"><a name="idm214184167584"></a><p class="title"><b>Example 1. Hello World</b></p><div class="example-contents"><p>A daemon may log with the log level
  56                         NOTICE by issuing this call:</p><pre class="programlisting">fprintf(stderr, SD_NOTICE "Hello World!\n");</pre></div></div><br class="example-break"></div><div class="refsect1"><a name="idm214180497360"></a><h2 id="Notes">Notes<a class="headerlink" title="Permalink to this headline" href="#Notes">¶</a></h2><p><a name="pkgconfig-text"></a>These APIs are implemented as a shared
  57   library, which can be compiled and linked to with the
  58   <code class="constant">libsystemd</code> <a href="pkg-config.html"><span class="citerefentry"><span class="refentrytitle">pkg-config</span>(1)</span></a>
  59   file.</p></div><div class="refsect1"><a name="idm214184164912"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
  60                         <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
  61                         <a href="sd_listen_fds.html"><span class="citerefentry"><span class="refentrytitle">sd_listen_fds</span>(3)</span></a>,
  62                         <a href="sd_notify.html"><span class="citerefentry"><span class="refentrytitle">sd_notify</span>(3)</span></a>,
  63                         <a href="sd_booted.html"><span class="citerefentry"><span class="refentrytitle">sd_booted</span>(3)</span></a>,
  64                         <a href="sd_is_fifo.html"><span class="citerefentry"><span class="refentrytitle">sd_is_fifo</span>(3)</span></a>,
  65                         <a href="sd_watchdog_enabled.html"><span class="citerefentry"><span class="refentrytitle">sd_watchdog_enabled</span>(3)</span></a>,
  66                         <a href="daemon.html"><span class="citerefentry"><span class="refentrytitle">daemon</span>(7)</span></a>,
  67                         <a href="systemd.service.html"><span class="citerefentry"><span class="refentrytitle">systemd.service</span>(5)</span></a>,
  68                         <a href="systemd.socket.html"><span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span></a>,
  69                         <a href="fprintf.html"><span class="citerefentry"><span class="refentrytitle">fprintf</span>(3)</span></a>,
  70                         <a href="sd-readahead.html"><span class="citerefentry"><span class="refentrytitle">sd-readahead</span>(3)</span></a>,
  71                         <a href="pkg-config.html"><span class="citerefentry"><span class="refentrytitle">pkg-config</span>(1)</span></a>
  72                 </p></div></div></body></html>