2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
6 <refentry id=
"systemd-socket-activate"
7 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
10 <title>systemd-socket-activate
</title>
11 <productname>systemd
</productname>
15 <refentrytitle>systemd-socket-activate
</refentrytitle>
16 <manvolnum>1</manvolnum>
20 <refname>systemd-socket-activate
</refname>
21 <refpurpose>Test socket activation of daemons
</refpurpose>
26 <command>systemd-socket-activate
</command>
27 <arg choice=
"opt" rep=
"repeat">OPTIONS
</arg>
28 <arg choice=
"plain"><replaceable>daemon
</replaceable></arg>
29 <arg choice=
"opt" rep=
"repeat">OPTIONS
</arg>
34 <title>Description
</title>
36 <para><command>systemd-socket-activate
</command> may be used to launch a socket-activated service program from the
37 command line for testing purposes. It may also be used to launch individual instances of the service program per
41 <para>The daemon to launch and its options should be specified
42 after options intended for
<command>systemd-socket-activate
</command>.
45 <para>If the
<option>--inetd
</option> option is given, the socket file descriptor will be used as the standard
46 input and output of the launched process. Otherwise, standard input and output will be inherited, and sockets will
47 be passed through file descriptors
3 and higher. Sockets passed through
<varname>$LISTEN_FDS
</varname> to
48 <command>systemd-socket-activate
</command> will be passed through to the daemon, in the original positions. Other sockets
49 specified with
<option>--listen=
</option> will use consecutive descriptors. By default,
50 <command>systemd-socket-activate
</command> listens on a stream socket, use
<option>--datagram
</option> and
51 <option>--seqpacket
</option> to listen on datagram or sequential packet sockets instead (see below).
56 <title>Options
</title>
59 <term><option>-l
<replaceable>address
</replaceable></option></term>
60 <term><option>--listen=
<replaceable>address
</replaceable></option></term>
62 <listitem><para>Listen on this
<replaceable>address
</replaceable>.
63 Takes a string like
<literal>2000</literal> or
64 <literal>127.0.0.1:
2001</literal>.
</para>
69 <term><option>-a
</option></term>
70 <term><option>--accept
</option></term>
72 <listitem><para>Launch an instance of the service program for each connection and pass the connection
73 socket.
</para></listitem>
77 <term><option>-d
</option></term>
78 <term><option>--datagram
</option></term>
80 <listitem><para>Listen on a datagram socket (
<constant>SOCK_DGRAM
</constant>), instead of a stream socket
81 (
<constant>SOCK_STREAM
</constant>). May not be combined with
<option>--seqpacket
</option>.
</para></listitem>
85 <term><option>--seqpacket
</option></term>
87 <listitem><para>Listen on a sequential packet socket (
<constant>SOCK_SEQPACKET
</constant>), instead of a stream
88 socket (
<constant>SOCK_STREAM
</constant>). May not be combined with
89 <option>--datagram
</option>.
</para></listitem>
93 <term><option>--inetd
</option></term>
95 <listitem><para>Use the inetd protocol for passing file descriptors, i.e. as standard input and standard
96 output, instead of the new-style protocol for passing file descriptors using
<varname>$LISTEN_FDS
</varname>
97 (see above).
</para></listitem>
101 <term><option>-E
<replaceable>VAR
</replaceable><optional>=
<replaceable>VALUE
</replaceable></optional></option></term>
102 <term><option>--setenv=
<replaceable>VAR
</replaceable><optional>=
<replaceable>VALUE
</replaceable></optional></option></term>
104 <listitem><para>Add this variable to the environment of the
105 launched process. If
<replaceable>VAR
</replaceable> is
106 followed by
<literal>=
</literal>, assume that it is a
107 variable–value pair. Otherwise, obtain the value from the
108 environment of
<command>systemd-socket-activate
</command> itself.
113 <term><option>--fdname=
</option><replaceable>NAME
</replaceable><optional>:
<replaceable>NAME
</replaceable>…
</optional></term>
115 <listitem><para>Specify names for the file descriptors passed. This is equivalent to setting
116 <varname>FileDescriptorName=
</varname> in socket unit files, and enables use of
117 <citerefentry><refentrytitle>sd_listen_fds_with_names
</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
118 Multiple entries may be specifies using separate options or by separating names with colons
119 (
<literal>:
</literal>) in one option. In case more names are given than descriptors, superfluous ones will be
120 ignored. In case less names are given than descriptors, the remaining file descriptors will be unnamed.
124 <xi:include href=
"standard-options.xml" xpointer=
"help" />
125 <xi:include href=
"standard-options.xml" xpointer=
"version" />
130 <title>Environment variables
</title>
131 <variablelist class='environment-variables'
>
133 <term><varname>$LISTEN_FDS
</varname></term>
134 <term><varname>$LISTEN_PID
</varname></term>
135 <term><varname>$LISTEN_FDNAMES
</varname></term>
138 <citerefentry><refentrytitle>sd_listen_fds
</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para></listitem>
142 <term><varname>$SYSTEMD_LOG_TARGET
</varname></term>
143 <term><varname>$SYSTEMD_LOG_LEVEL
</varname></term>
144 <term><varname>$SYSTEMD_LOG_COLOR
</varname></term>
145 <term><varname>$SYSTEMD_LOG_LOCATION
</varname></term>
147 <listitem><para>Same as in
148 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
</para></listitem>
154 <title>Examples
</title>
157 <title>Run an echo server on port
2000</title>
159 <programlisting>$ systemd-socket-activate -l
2000 --inetd -a cat
</programlisting>
163 <title>Run a socket-activated instance of
<citerefentry><refentrytitle>systemd-journal-gatewayd
</refentrytitle><manvolnum>8</manvolnum></citerefentry></title>
165 <programlisting>$ systemd-socket-activate -l
19531 /usr/lib/systemd/systemd-journal-gatewayd
</programlisting>
170 <title>See Also
</title>
172 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
173 <citerefentry><refentrytitle>systemd.socket
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
174 <citerefentry><refentrytitle>systemd.service
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
175 <citerefentry><refentrytitle>systemd-run
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
176 <citerefentry><refentrytitle>sd_listen_fds
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
177 <citerefentry><refentrytitle>sd_listen_fds_with_names
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
178 <citerefentry project='man-pages'
><refentrytitle>cat
</refentrytitle><manvolnum>1</manvolnum></citerefentry>