+ mark to negate the check.</para>
+
+ <para><varname>ConditionACPower=</varname>
+ may be used to check whether the
+ system has AC power, or is exclusively
+ battery powered at the time of
+ activation of the unit. This takes a
+ boolean argument. If set to
+ <varname>true</varname>, the condition
+ will hold only if at least one AC
+ connector of the system is connected
+ to a power source, or if no AC
+ connectors are known. Conversely, if
+ set to <varname>false</varname>, the
+ condition will hold only if there is
+ at least one AC connector known and
+ all AC connectors are disconnected
+ from a power source.</para>
+
+ <para><varname>ConditionNeedsUpdate=</varname>
+ takes one of <filename>/var</filename>
+ or <filename>/etc</filename> as
+ argument, possibly prefixed with a
+ <literal>!</literal> (for inverting
+ the condition). This condition may be
+ used to conditionalize units on
+ whether the specified directory
+ requires an update because
+ <filename>/usr</filename>'s
+ modification time is newer than the
+ stamp file
+ <filename>.updated</filename> in the
+ specified directory. This is useful to
+ implement offline updates of the
+ vendor operating system resources in
+ <filename>/usr</filename> that require
+ updating of <filename>/etc</filename>
+ or <filename>/var</filename> on the
+ next following boot. Units making use
+ of this condition should order
+ themselves before
+ <citerefentry><refentrytitle>systemd-update-done.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ to make sure they run before the stamp
+ files's modification time gets reset
+ indicating a completed update.</para>
+
+ <para><varname>ConditionFirstBoot=</varname>
+ takes a boolean argument. This
+ condition may be used to
+ conditionalize units on whether the
+ system is booting up with an
+ unpopulated <filename>/etc</filename>
+ directory. This may be used to
+ populate <filename>/etc</filename> on
+ the first boot after factory reset, or
+ when a new system instances boots up
+ for the first time.</para>
+
+ <para>With
+ <varname>ConditionPathExists=</varname>
+ a file existence condition is
+ checked before a unit is started. If
+ the specified absolute path name does
+ not exist, the condition will
+ fail. If the absolute path name passed
+ to
+ <varname>ConditionPathExists=</varname>
+ is prefixed with an exclamation mark
+ (<literal>!</literal>), the test is negated, and the unit
+ is only started if the path does not
+ exist.</para>
+
+ <para><varname>ConditionPathExistsGlob=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>,
+ but checks for the existence of at
+ least one file or directory matching
+ the specified globbing pattern.</para>
+
+ <para><varname>ConditionPathIsDirectory=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and is a
+ directory.</para>
+
+ <para><varname>ConditionPathIsSymbolicLink=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and is a symbolic
+ link.</para>
+
+ <para><varname>ConditionPathIsMountPoint=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and is a mount
+ point.</para>
+
+ <para><varname>ConditionPathIsReadWrite=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether the underlying
+ file system is readable and writable
+ (i.e. not mounted
+ read-only).</para>
+
+ <para><varname>ConditionDirectoryNotEmpty=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and is a non-empty
+ directory.</para>
+
+ <para><varname>ConditionFileNotEmpty=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and refers to a regular file
+ with a non-zero size.</para>
+
+ <para><varname>ConditionFileIsExecutable=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists, is a regular file and marked
+ executable.</para>
+
+ <para>Finally,