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1 | <?xml version='1.0'?> <!--*-nxml-*--> |
2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
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4 | |
5 | <!-- | |
572eb058 | 6 | SPDX-License-Identifier: LGPL-2.1+ |
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7 | --> |
8 | ||
dfdebb1b | 9 | <refentry id="runlevel" |
798d3a52 | 10 | xmlns:xi="http://www.w3.org/2001/XInclude" |
3211da4b | 11 | conditional="ENABLE_UTMP"> |
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12 | |
13 | <refentryinfo> | |
14 | <title>runlevel</title> | |
15 | <productname>systemd</productname> | |
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16 | </refentryinfo> |
17 | ||
18 | <refmeta> | |
19 | <refentrytitle>runlevel</refentrytitle> | |
20 | <manvolnum>8</manvolnum> | |
21 | </refmeta> | |
22 | ||
23 | <refnamediv> | |
24 | <refname>runlevel</refname> | |
25 | <refpurpose>Print previous and current SysV runlevel</refpurpose> | |
26 | </refnamediv> | |
27 | ||
28 | <refsynopsisdiv> | |
29 | <cmdsynopsis> | |
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30 | <command>runlevel</command> |
31 | <arg choice="opt" rep="repeat">options</arg> | |
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32 | </cmdsynopsis> |
33 | </refsynopsisdiv> | |
34 | ||
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35 | <refsect1> |
36 | <title>Overview</title> | |
37 | ||
38 | <para>"Runlevels" are an obsolete way to start and stop groups of | |
39 | services used in SysV init. systemd provides a compatibility layer | |
40 | that maps runlevels to targets, and associated binaries like | |
41 | <command>runlevel</command>. Nevertheless, only one runlevel can | |
42 | be "active" at a given time, while systemd can activate multiple | |
43 | targets concurrently, so the mapping to runlevels is confusing | |
44 | and only approximate. Runlevels should not be used in new code, | |
45 | and are mostly useful as a shorthand way to refer the matching | |
46 | systemd targets in kernel boot parameters.</para> | |
47 | ||
48 | <table> | |
49 | <title>Mapping between runlevels and systemd targets</title> | |
50 | <tgroup cols='2' align='left' colsep='1' rowsep='1'> | |
51 | <colspec colname="runlevel" /> | |
52 | <colspec colname="target" /> | |
53 | <thead> | |
54 | <row> | |
55 | <entry>Runlevel</entry> | |
56 | <entry>Target</entry> | |
57 | </row> | |
58 | </thead> | |
59 | <tbody> | |
60 | <row> | |
61 | <entry>0</entry> | |
62 | <entry><filename>poweroff.target</filename></entry> | |
63 | </row> | |
64 | <row> | |
65 | <entry>1</entry> | |
66 | <entry><filename>rescue.target</filename></entry> | |
67 | </row> | |
68 | <row> | |
69 | <entry>2, 3, 4</entry> | |
70 | <entry><filename>multi-user.target</filename></entry> | |
71 | </row> | |
72 | <row> | |
73 | <entry>5</entry> | |
74 | <entry><filename>graphical.target</filename></entry> | |
75 | </row> | |
76 | <row> | |
77 | <entry>6</entry> | |
78 | <entry><filename>reboot.target</filename></entry> | |
79 | </row> | |
80 | </tbody> | |
81 | </tgroup> | |
82 | </table> | |
83 | </refsect1> | |
84 | ||
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85 | <refsect1> |
86 | <title>Description</title> | |
87 | ||
88 | <para><command>runlevel</command> prints the previous and current | |
89 | SysV runlevel if they are known.</para> | |
90 | ||
91 | <para>The two runlevel characters are separated by a single space | |
92 | character. If a runlevel cannot be determined, N is printed | |
93 | instead. If neither can be determined, the word "unknown" is | |
94 | printed.</para> | |
95 | ||
96 | <para>Unless overridden in the environment, this will check the | |
97 | utmp database for recent runlevel changes.</para> | |
98 | </refsect1> | |
99 | ||
100 | <refsect1> | |
101 | <title>Options</title> | |
102 | ||
103 | <para>The following option is understood:</para> | |
104 | ||
105 | <variablelist> | |
106 | <varlistentry> | |
107 | <term><option>--help</option></term> | |
108 | ||
109 | <xi:include href="standard-options.xml" xpointer="help-text" /> | |
110 | </varlistentry> | |
111 | </variablelist> | |
112 | ||
113 | </refsect1> | |
114 | ||
115 | <refsect1> | |
116 | <title>Exit status</title> | |
117 | ||
118 | <para>If one or both runlevels could be determined, 0 is returned, | |
119 | a non-zero failure code otherwise.</para> | |
120 | ||
121 | </refsect1> | |
122 | ||
123 | <refsect1> | |
124 | <title>Environment</title> | |
125 | ||
126 | <variablelist class='environment-variables'> | |
127 | <varlistentry> | |
128 | <term><varname>$RUNLEVEL</varname></term> | |
129 | ||
130 | <listitem><para>If <varname>$RUNLEVEL</varname> is set, | |
131 | <command>runlevel</command> will print this value as current | |
132 | runlevel and ignore utmp.</para></listitem> | |
133 | </varlistentry> | |
134 | ||
135 | <varlistentry> | |
136 | <term><varname>$PREVLEVEL</varname></term> | |
137 | ||
138 | <listitem><para>If <varname>$PREVLEVEL</varname> is set, | |
139 | <command>runlevel</command> will print this value as previous | |
140 | runlevel and ignore utmp.</para></listitem> | |
141 | </varlistentry> | |
142 | </variablelist> | |
143 | </refsect1> | |
144 | ||
145 | <refsect1> | |
146 | <title>Files</title> | |
147 | ||
148 | <variablelist> | |
149 | <varlistentry> | |
8c095a07 | 150 | <term><filename>/run/utmp</filename></term> |
798d3a52 | 151 | |
8c095a07 | 152 | <listitem><para>The utmp database <command>runlevel</command> reads the previous and current runlevel |
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153 | from.</para></listitem> |
154 | </varlistentry> | |
155 | </variablelist> | |
156 | </refsect1> | |
157 | ||
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158 | <refsect1> |
159 | <title>See Also</title> | |
160 | <para> | |
161 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
9f6434a6 | 162 | <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
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163 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> |
164 | </para> | |
165 | </refsect1> | |
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166 | |
167 | </refentry> |