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
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
SPDX-License-Identifier: LGPL-2.1+
-->
<refentry id="runlevel"
xmlns:xi="http://www.w3.org/2001/XInclude"
conditional="ENABLE_UTMP">
<refentryinfo>
<title>runlevel</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>runlevel</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>runlevel</refname>
<refpurpose>Print previous and current SysV runlevel</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>runlevel</command>
<arg choice="opt" rep="repeat">options</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Overview</title>
<para>"Runlevels" are an obsolete way to start and stop groups of
services used in SysV init. systemd provides a compatibility layer
that maps runlevels to targets, and associated binaries like
<command>runlevel</command>. Nevertheless, only one runlevel can
be "active" at a given time, while systemd can activate multiple
targets concurrently, so the mapping to runlevels is confusing
and only approximate. Runlevels should not be used in new code,
and are mostly useful as a shorthand way to refer the matching
systemd targets in kernel boot parameters.</para>
<table>
<title>Mapping between runlevels and systemd targets</title>
<tgroup cols='2' align='left' colsep='1' rowsep='1'>
<colspec colname="runlevel" />
<colspec colname="target" />
<thead>
<row>
<entry>Runlevel</entry>
<entry>Target</entry>
</row>
</thead>
<tbody>
<row>
<entry>0</entry>
<entry><filename>poweroff.target</filename></entry>
</row>
<row>
<entry>1</entry>
<entry><filename>rescue.target</filename></entry>
</row>
<row>
<entry>2, 3, 4</entry>
<entry><filename>multi-user.target</filename></entry>
</row>
<row>
<entry>5</entry>
<entry><filename>graphical.target</filename></entry>
</row>
<row>
<entry>6</entry>
<entry><filename>reboot.target</filename></entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
<title>Description</title>
<para><command>runlevel</command> prints the previous and current
SysV runlevel if they are known.</para>
<para>The two runlevel characters are separated by a single space
character. If a runlevel cannot be determined, N is printed
instead. If neither can be determined, the word "unknown" is
printed.</para>
<para>Unless overridden in the environment, this will check the
utmp database for recent runlevel changes.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following option is understood:</para>
<variablelist>
<varlistentry>
<term><option>--help</option></term>
<xi:include href="standard-options.xml" xpointer="help-text" />
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
<para>If one or both runlevels could be determined, 0 is returned,
a non-zero failure code otherwise.</para>
</refsect1>
<refsect1>
<title>Environment</title>
<variablelist class='environment-variables'>
<varlistentry>
<term><varname>$RUNLEVEL</varname></term>
<listitem><para>If <varname>$RUNLEVEL</varname> is set,
<command>runlevel</command> will print this value as current
runlevel and ignore utmp.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>$PREVLEVEL</varname></term>
<listitem><para>If <varname>$PREVLEVEL</varname> is set,
<command>runlevel</command> will print this value as previous
runlevel and ignore utmp.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Files</title>
<variablelist>
<varlistentry>
<term><filename>/run/utmp</filename></term>
<listitem><para>The utmp database <command>runlevel</command> reads the previous and current runlevel
from.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
|
