X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=man%2Fsystemd.unit.xml;h=a52e3e9ef332d3c372f0aa0d3a714fae87f2ee39;hb=b439c6ee04967fa988d232e0765f972cb27b1877;hp=81634410c15244d4f529cf8cc3e02c4bf55eacb5;hpb=0d624a785aed0423ee87f70d33de97df9662844b;p=elogind.git

diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index 81634410c..a52e3e9ef 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -105,7 +105,7 @@
                 <para>Time span values encoded in unit files can be
                 written in various formats. A stand-alone number
                 specifies a time in seconds. If suffixed with a time
-                unit, the unit is honored. A concatentation of
+                unit, the unit is honored. A concatenation of
                 multiple value with units is supported, in which case
                 the values are added up. Example: "50" refers to 50
                 seconds; "2min 200ms" refers to 2 minutes plus 200
@@ -144,6 +144,47 @@
                 activation which makes dependencies implicit, which
                 both results in a simpler and more flexible
                 system.</para>
+
+                <para>Some unit names reflect paths existing in the
+                file system name space. Example: a device unit
+                <filename>dev-sda.device</filename> refers to a device
+                with the device node <filename>/dev/sda</filename> in
+                the file system namespace. If this applies a special
+                way to escape the path name is used, so that it is
+                usable as part of a file name. Basically, given a
+                path, "/" is replaced by "-", and all unprintable
+                characters and the "-" are replaced by C-style "\x20"
+                escapes. The root directory "/" is encoded as single
+                dash, while otherwise the initial and ending "/" is
+                removed from all paths during transformation. This
+                escaping is reversible.</para>
+
+                <para>Optionally, units may be instantiated from a
+                template file at runtime. This allows creation of
+                multiple units from a single configuration file. If
+                systemd looks for a unit configuration file it will
+                first search for the literal unit name in the
+                filesystem. If that yields no success and the unit
+                name contains an @ character, systemd will look for a
+                unit template that shares the same name but with the
+                instance string (i.e. the part between the @ character
+                and the suffix) removed. Example: if a service
+                <filename>getty@tty3.service</filename> is requested
+                and no file by that name is found, systemd will look
+                for <filename>getty@.service</filename> and
+                instantiate a service from that configuration file if
+                it is found. To refer to the instance string from
+                within the configuration file you may use the special
+                <literal>%i</literal> specifier in many of the
+                configuration options. Other specifiers that may be
+                used are <literal>%n</literal>, <literal>%N</literal>,
+                <literal>%p</literal>, <literal>%P</literal> and
+                <literal>%I</literal>, for the full unit name, the
+                unescaped unit name, the prefix name, the unescaped
+                prefix name and the unescaped instance name,
+                respectively. The prefix name here refers to the
+                string before the @, i.e. "getty" in the example
+                above, where "tty3" is the instance name.</para>
         </refsect1>
 
         <refsect1>