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Diffstat (limited to 'man/systemd.unit.xml')
| -rw-r--r-- | man/systemd.unit.xml | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml index 81634410c1..da077e2097 100644 --- a/man/systemd.unit.xml +++ b/man/systemd.unit.xml @@ -144,6 +144,44 @@ 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. 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> |