1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>sd_is_fifo</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>·
<span style="float:right">systemd 221</span><hr><div class="refentry"><a name="sd_is_fifo"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>sd_is_fifo, sd_is_socket, sd_is_socket_inet, sd_is_socket_unix, sd_is_mq, sd_is_special — Check the type of a file descriptor</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><pre class="funcsynopsisinfo">#include <systemd/sd-daemon.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_is_fifo</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>const char *<var class="pdparam">path</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_is_socket</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">family</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">type</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">listening</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_is_socket_inet</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">family</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">type</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">listening</var>, </td></tr><tr><td> </td><td>uint16_t <var class="pdparam">port</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_is_socket_unix</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">type</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">listening</var>, </td></tr><tr><td> </td><td>const char *<var class="pdparam">path</var>, </td></tr><tr><td> </td><td>size_t <var class="pdparam">length</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_is_mq</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>const char *<var class="pdparam">path</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_is_special</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>const char *<var class="pdparam">path</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="idm47917962894864"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p><code class="function">sd_is_fifo()</code> may be called to check
whether the specified file descriptor refers to a FIFO or pipe. If
the <em class="parameter"><code>path</code></em> parameter is not
<code class="constant">NULL</code>, it is checked whether the FIFO is bound
to the specified file system path.</p><p><code class="function">sd_is_socket()</code> may be called to check
whether the specified file descriptor refers to a socket. If the
<em class="parameter"><code>family</code></em> parameter is not
<code class="constant">AF_UNSPEC</code>, it is checked whether the socket
is of the specified family (AF_UNIX, <code class="constant">AF_INET</code>,
...). If the <em class="parameter"><code>type</code></em> parameter is not 0, it is
checked whether the socket is of the specified type
(<code class="constant">SOCK_STREAM</code>,
<code class="constant">SOCK_DGRAM</code>, ...). If the
<em class="parameter"><code>listening</code></em> parameter is positive, it is
checked whether the socket is in accepting mode, i.e.
<code class="function">listen()</code> has been called for it. If
<em class="parameter"><code>listening</code></em> is 0, it is checked whether the
socket is not in this mode. If the parameter is negative, no such
check is made. The <em class="parameter"><code>listening</code></em> parameter
should only be used for stream sockets and should be set to a
negative value otherwise.</p><p><code class="function">sd_is_socket_inet()</code> is similar to
<code class="function">sd_is_socket()</code>, but optionally checks the
IPv4 or IPv6 port number the socket is bound to, unless
<em class="parameter"><code>port</code></em> is zero. For this call
<em class="parameter"><code>family</code></em> must be passed as either
<code class="constant">AF_UNSPEC</code>, <code class="constant">AF_INET</code>, or
<code class="constant">AF_INET6</code>.</p><p><code class="function">sd_is_socket_unix()</code> is similar to
<code class="function">sd_is_socket()</code> but optionally checks the
<code class="constant">AF_UNIX</code> path the socket is bound to, unless
the <em class="parameter"><code>path</code></em> parameter is
<code class="constant">NULL</code>. For normal file system
<code class="constant">AF_UNIX</code> sockets, set the
<em class="parameter"><code>length</code></em> parameter to 0. For Linux abstract
namespace sockets, set the <em class="parameter"><code>length</code></em> to the
size of the address, including the initial 0 byte, and set the
<em class="parameter"><code>path</code></em> to the initial 0 byte of the socket
address.</p><p><code class="function">sd_is_mq()</code> may be called to check
whether the specified file descriptor refers to a POSIX message
queue. If the <em class="parameter"><code>path</code></em> parameter is not
<code class="constant">NULL</code>, it is checked whether the message queue
is bound to the specified name.</p><p><code class="function">sd_is_special()</code> may be called to check
whether the specified file descriptor refers to a special file. If
the <em class="parameter"><code>path</code></em> parameter is not
<code class="constant">NULL</code>, it is checked whether the file
descriptor is bound to the specified file name. Special files in
this context are character device nodes and files in
<code class="filename">/proc</code> or <code class="filename">/sys</code>.</p></div><div class="refsect1"><a name="idm47917962870336"></a><h2 id="Return Value">Return Value<a class="headerlink" title="Permalink to this headline" href="#Return%20Value">¶</a></h2><p>On failure, these calls return a negative errno-style error
code. If the file descriptor is of the specified type and bound to
the specified address, a positive return value is returned,
otherwise zero.</p></div><div class="refsect1"><a name="idm47917962868960"></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
library, which can be compiled and linked to with the
<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>
file.</p><p>Internally, these function use a combination of
<code class="filename">fstat()</code> and
<code class="filename">getsockname()</code> to check the file descriptor
type and where it is bound to.</p></div><div class="refsect1"><a name="idm47917962865824"></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-daemon.html"><span class="citerefentry"><span class="refentrytitle">sd-daemon</span>(3)</span></a>,
<a href="sd_listen_fds.html"><span class="citerefentry"><span class="refentrytitle">sd_listen_fds</span>(3)</span></a>,
<a href="systemd.service.html"><span class="citerefentry"><span class="refentrytitle">systemd.service</span>(5)</span></a>,
<a href="systemd.socket.html"><span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span></a>
</p></div></div></body></html>
|
