snmp plugin: Fix a possible memory leak.

[collectd.git] / src / collectd-exec.pod

diff --git a/src/collectd-exec.pod b/src/collectd-exec.pod
index fe2fd63..9882601 100644 (file)
--- a/src/collectd-exec.pod
+++ b/src/collectd-exec.pod
@@ -55,21 +55,6 @@ run at once if multiple notifications are received.
 See L<NOTIFICATION DATA FORMAT> below for a description of the data passed to
 these programs.
 
-=begin comment
-
-=item C<NagiosExec>
-
-The executable is treated as a Nagios plugin. That means that the first line
-printed to C<STDOUT> by this program is used as the text of a notification and
-the severity of the notification depends on the exit status of the executable
-only.
-
-For information on how to write Nagios plugins please refer to the Nagios
-documentation. If a plugin works with Nagios but not with collectd please
-complain on the collectd mailing list instead.
-
-=end comment
-
 =back
 
 =head1 EXEC DATA FORMAT
@@ -200,17 +185,19 @@ The notification executables receive values rather than providing them. In
 fact, after the program is started C<STDOUT> is connected to C</dev/null>.
 
 The data is passed to the executables over C<STDIN> in a format very similar to
-HTTP-headers: There is one line per field. Every line consists of a field name,
-ended by a colon, and the associated value until end-of-line. The input is
-ended by two newlines immediately following another.
+HTTP: At first there is a "header" with one line per field. Every line consists
+of a field name, ended by a colon, and the associated value until end-of-line.
+The "header" is ended by two newlines immediately following another,
+i.E<nbsp>e. an empty line. The rest, basically the "body", is the message of
+the notification.
 
 The following is an example notification passed to a program:
 
   Severity: FAILURE
   Time: 1200928930
   Host: myhost.mydomain.org
-  Message: This is a test notification to demonstrate the format
-  <newline>
+  \n
+  This is a test notification to demonstrate the format
 
 The following header files are currently used. Please note, however, that you
 should ignore unknown header files to be as forward-compatible as possible.
@@ -227,15 +214,37 @@ The time in epoch, i.E<nbsp>e. as seconds since 1970-01-01 00:00:00 UTC.
 
 =item B<Host>
 
-Name of the host concerned.
+=item B<Plugin>
+
+=item B<PluginInstance>
 
-=item B<Message>
+=item B<Type>
 
-Message of the notification. This message should be made accessible to the
-user somehow.
+=item B<TypeInstance>
+
+Identification of the performance data this notification is associated with.
+All of these fields are optional because notifications do not B<need> to be
+associated with a certain value.
 
 =back
 
+=head1 USING NAGIOS PLUGINS
+
+Though the interface is far from perfect, there are tons of plugins for Nagios.
+You can use these plugins with collectd by using a simple transition layer,
+C<exec-nagios.px>, which is shipped with the collectd distribution in the
+C<contrib/> directory. It is a simple Perl script that comes with embedded
+documentation. To see it, run the following command:
+
+  perldoc exec-nagios.px
+
+This script expects a configuration file, C<exec-nagios.conf>. You can find an
+example in the C<contrib/> directory, too.
+
+Even a simple mechanism to submit "performance data" to collectd is
+implemented. If you need a more sophisticated setup, please rewrite the plugin
+to make use of collectd's more powerful interface.
+
 =head1 CAVEATS
 
 =over 4