chiark / gitweb /
machined: optionally, allow registration of pre-existing units (scopes
[elogind.git] / man / tmpfiles.d.xml
index 331fd1b..a304dd0 100644 (file)
@@ -88,8 +88,8 @@
                 the local administrator, who may use this logic to
                 override the configuration files installed by vendor
                 packages. All configuration files are sorted by their
-                filename in lexicographic order, regardless in which
-                of the directories they reside. If multiple files
+                filename in lexicographic order, regardless of which
+                of the directories they reside in. If multiple files
                 specify the same path, the entry in the file with the
                 lexicographically earliest name will be applied, all
                 all other conflicting entries logged as errors.</para>
@@ -113,6 +113,9 @@ L    /tmp/foobar -    -    -    -   /dev/null</programlisting>
                 <refsect2>
                         <title>Type</title>
 
+                        <para>The type consists of a single letter and
+                        optionally an exclamation mark.</para>
+
                         <para>The following line types are understood:</para>
 
                         <variablelist>
@@ -171,7 +174,7 @@ L    /tmp/foobar -    -    -    -   /dev/null</programlisting>
                                         adjust its access mode, group
                                         and user to the specified
                                         values and reset the SELinux
-                                        label. If it does not exist, do
+                                        security context. If it does not exist, do
                                         nothing.</para></listitem>
                                 </varlistentry>
 
@@ -239,7 +242,7 @@ L    /tmp/foobar -    -    -    -   /dev/null</programlisting>
                                 <varlistentry>
                                         <term><varname>z</varname></term>
                                         <listitem><para>Restore
-                                        SELinux security context label
+                                        SELinux security context
                                         and set ownership and access
                                         mode of a file or directory if
                                         it exists.  Lines of this type
@@ -252,7 +255,7 @@ L    /tmp/foobar -    -    -    -   /dev/null</programlisting>
                                         <term><varname>Z</varname></term>
                                         <listitem><para>Recursively
                                         restore SELinux security
-                                        context label and set
+                                        context and set
                                         ownership and access mode of a
                                         path and all its
                                         subdirectories (if it is a
@@ -262,6 +265,28 @@ L    /tmp/foobar -    -    -    -   /dev/null</programlisting>
                                         names.</para></listitem>
                                 </varlistentry>
                         </variablelist>
+
+                        <para>If the exclamation mark is used, this
+                        line is only safe of execute during boot, and
+                        can break a running system. Lines without the
+                        exclamation mark are presumed to be safe to
+                        execute at any time, e.g. on package upgrades.
+                        <command>systemd-tmpfiles</command> will
+                        execute line with an exclamation mark only if
+                        option <option>--boot</option> is given.
+                        </para>
+
+                        <para>For example:
+                        <programlisting>
+# Make sure these are created by default so that nobody else can
+d /tmp/.X11-unix 1777 root root 10d
+
+# Unlink the X11 lock files
+r! /tmp/.X[0-9]*-lock
+                        </programlisting>
+                        The second line in contrast to the first one
+                        would break a running system, and will only be
+                        executed with <option>--boot</option>.</para>
                 </refsect2>
 
                 <refsect2>