2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 SPDX-License-Identifier: LGPL-2.1+
9 <refentry id=
"systemd-socket-activate"
10 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
13 <title>systemd-socket-activate
</title>
14 <productname>systemd
</productname>
18 <refentrytitle>systemd-socket-activate
</refentrytitle>
19 <manvolnum>1</manvolnum>
23 <refname>systemd-socket-activate
</refname>
24 <refpurpose>Test socket activation of daemons
</refpurpose>
29 <command>systemd-socket-activate
</command>
30 <arg choice=
"opt" rep=
"repeat">OPTIONS
</arg>
31 <arg choice=
"plain"><replaceable>daemon
</replaceable></arg>
32 <arg choice=
"opt" rep=
"repeat">OPTIONS
</arg>
37 <title>Description
</title>
39 <para><command>systemd-socket-activate
</command> may be used to launch a socket-activated service program from the
40 command line for testing purposes. It may also be used to launch individual instances of the service program per
44 <para>The daemon to launch and its options should be specified
45 after options intended for
<command>systemd-socket-activate
</command>.
48 <para>If the
<option>--inetd
</option> option is given, the socket file descriptor will be used as the standard
49 input and output of the launched process. Otherwise, standard input and output will be inherited, and sockets will
50 be passed through file descriptors
3 and higher. Sockets passed through
<varname>$LISTEN_FDS
</varname> to
51 <command>systemd-socket-activate
</command> will be passed through to the daemon, in the original positions. Other sockets
52 specified with
<option>--listen=
</option> will use consecutive descriptors. By default,
53 <command>systemd-socket-activate
</command> listens on a stream socket, use
<option>--datagram
</option> and
54 <option>--seqpacket
</option> to listen on datagram or sequential packet sockets instead (see below).
59 <title>Options
</title>
62 <term><option>-l
<replaceable>address
</replaceable></option></term>
63 <term><option>--listen=
<replaceable>address
</replaceable></option></term>
65 <listitem><para>Listen on this
<replaceable>address
</replaceable>.
66 Takes a string like
<literal>2000</literal> or
67 <literal>127.0.0.1:
2001</literal>.
</para>
72 <term><option>-a
</option></term>
73 <term><option>--accept
</option></term>
75 <listitem><para>Launch an instance of the service program for each connection and pass the connection
76 socket.
</para></listitem>
80 <term><option>-d
</option></term>
81 <term><option>--datagram
</option></term>
83 <listitem><para>Listen on a datagram socket (
<constant>SOCK_DGRAM
</constant>), instead of a stream socket
84 (
<constant>SOCK_STREAM
</constant>). May not be combined with
<option>--seqpacket
</option>.
</para></listitem>
88 <term><option>--seqpacket
</option></term>
90 <listitem><para>Listen on a sequential packet socket (
<constant>SOCK_SEQPACKET
</constant>), instead of a stream
91 socket (
<constant>SOCK_STREAM
</constant>). May not be combined with
92 <option>--datagram
</option>.
</para></listitem>
96 <term><option>--inetd
</option></term>
98 <listitem><para>Use the inetd protocol for passing file descriptors, i.e. as standard input and standard
99 output, instead of the new-style protocol for passing file descriptors using
<varname>$LISTEN_FDS
</varname>
100 (see above).
</para></listitem>
104 <term><option>-E
<replaceable>VAR
</replaceable><optional>=
<replaceable>VALUE
</replaceable></optional></option></term>
105 <term><option>--setenv=
<replaceable>VAR
</replaceable><optional>=
<replaceable>VALUE
</replaceable></optional></option></term>
107 <listitem><para>Add this variable to the environment of the
108 launched process. If
<replaceable>VAR
</replaceable> is
109 followed by
<literal>=
</literal>, assume that it is a
110 variable–value pair. Otherwise, obtain the value from the
111 environment of
<command>systemd-socket-activate
</command> itself.
116 <term><option>--fdname=
</option><replaceable>NAME
</replaceable><optional>:
<replaceable>NAME
</replaceable>…
</optional></term>
118 <listitem><para>Specify names for the file descriptors passed. This is equivalent to setting
119 <varname>FileDescriptorName=
</varname> in socket unit files, and enables use of
120 <citerefentry><refentrytitle>sd_listen_fds_with_names
</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
121 Multiple entries may be specifies using separate options or by separating names with colons
122 (
<literal>:
</literal>) in one option. In case more names are given than descriptors, superfluous ones will be
123 ignored. In case less names are given than descriptors, the remaining file descriptors will be unnamed.
127 <xi:include href=
"standard-options.xml" xpointer=
"help" />
128 <xi:include href=
"standard-options.xml" xpointer=
"version" />
133 <title>Environment variables
</title>
134 <variablelist class='environment-variables'
>
136 <term><varname>$LISTEN_FDS
</varname></term>
137 <term><varname>$LISTEN_PID
</varname></term>
138 <term><varname>$LISTEN_FDNAMES
</varname></term>
141 <citerefentry><refentrytitle>sd_listen_fds
</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para></listitem>
145 <term><varname>$SYSTEMD_LOG_TARGET
</varname></term>
146 <term><varname>$SYSTEMD_LOG_LEVEL
</varname></term>
147 <term><varname>$SYSTEMD_LOG_COLOR
</varname></term>
148 <term><varname>$SYSTEMD_LOG_LOCATION
</varname></term>
150 <listitem><para>Same as in
151 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
</para></listitem>
157 <title>Examples
</title>
160 <title>Run an echo server on port
2000</title>
162 <programlisting>$ systemd-socket-activate -l
2000 --inetd -a cat
</programlisting>
166 <title>Run a socket-activated instance of
<citerefentry><refentrytitle>systemd-journal-gatewayd
</refentrytitle><manvolnum>8</manvolnum></citerefentry></title>
168 <programlisting>$ systemd-socket-activate -l
19531 /usr/lib/systemd/systemd-journal-gatewayd
</programlisting>
173 <title>See Also
</title>
175 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
176 <citerefentry><refentrytitle>systemd.socket
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
177 <citerefentry><refentrytitle>systemd.service
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
178 <citerefentry><refentrytitle>systemd-run
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
179 <citerefentry><refentrytitle>sd_listen_fds
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
180 <citerefentry><refentrytitle>sd_listen_fds_with_names
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
181 <citerefentry project='man-pages'
><refentrytitle>cat
</refentrytitle><manvolnum>1</manvolnum></citerefentry>