man/journalctl: mention systemd-cat, make the description more direct

We said "query the journal". This is true but also very generic. Let's say
"print log entries from the journal" instead, so that users who are looking for
"logging" are more likely to figure out that the journalctl is the tool for
them.

Also, mention systemd-journal-remote.service which can write the journal too.
And give some hints how to figure out how to write *to* the journal.

1 files changed, 16 insertions, 7 deletions

diff --git a/man/journalctl.xml b/man/journalctl.xml
index 5ca5bc9740..d9ee51b302 100644
--- a/man/journalctl.xml
+++ b/man/journalctl.xml
@@ -18,7 +18,7 @@
 
   <refnamediv>
     <refname>journalctl</refname>
-    <refpurpose>Query the systemd journal</refpurpose>
+    <refpurpose>Print log entries from the the systemd journal</refpurpose>
   </refnamediv>
 
   <refsynopsisdiv>
@@ -32,13 +32,14 @@
   <refsect1>
     <title>Description</title>
 
-    <para><command>journalctl</command> may be used to query the contents of the
-    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> journal as
-    written by
-    <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
+    <para><command>journalctl</command> is used to print the log entries stored in the journal by
+    <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+    and
+    <citerefentry><refentrytitle>systemd-journal-remote.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+    </para>
 
-    <para>If called without parameters, it will show the full contents of the journal, starting with the
-    oldest entry collected.</para>
+    <para>If called without parameters, it will show the contents of the journal accessible to the calling
+    user, starting with the oldest entry collected.</para>
 
     <para>If one or more match arguments are passed, the output is filtered accordingly. A match is in the
     format <literal>FIELD=VALUE</literal>, e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>, referring to
@@ -93,6 +94,13 @@
     <para>When outputting to a tty, lines are colored according to priority: lines of level ERROR and higher
     are colored red; lines of level NOTICE and higher are highlighted; lines of level DEBUG are colored
     lighter grey; other lines are displayed normally.</para>
+
+    <para>To write entries <emphasis>to</emphasis> the journal, a few methods may be used. In general, output
+    from systemd units is automatically connected to the journal, see
+    <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+    In addition,
+    <citerefentry><refentrytitle>systemd-cat</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    may be used to send messages to the journal directly.</para>
   </refsect1>
 
   <refsect1>
@@ -930,6 +938,7 @@ journalctl _SYSTEMD_CGROUP=/user.slice/user-42.slice/session-c1.scope</programli
     <title>See Also</title>
     <para>
       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemd-cat</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,