man: systemctl: clarify that --lines=0 is allowed (#10375)

The term “positive” is often read to exclude 0 (though “strictly
positive” is sometimes used to clarify this), so let’s explicitly state
that --lines=0 is legal and completely disables journal output.

Motivated by an answer on StackExchange [1].

[1]: https://unix.stackexchange.com/a/475068/44049

diff --git a/man/systemctl.xml b/man/systemctl.xml
index b16efb8701a879527d311b96580f24dd9aaaf6e4..e32ee6cacb5e68e2562c8b3e26ad5690b6c0611a 100644 (file)
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -590,9 +590,8 @@
         <term><option>--lines=</option></term>
 
         <listitem>
-          <para>When used with <command>status</command>, controls the
-          number of journal lines to show, counting from the most
-          recent ones. Takes a positive integer argument. Defaults to
+          <para>When used with <command>status</command>, controls the number of journal lines to show, counting from
+          the most recent ones. Takes a positive integer argument, or 0 to disable journal output. Defaults to
           10.</para>
         </listitem>
       </varlistentry>