Merge pull request #673 from simon04/patch-1

Improved documentation for CheckLogFile

docs/docs/reference/check/CheckLogFile.md

@@ -97,13 +97,17 @@ They do not denote warning or critical state instead it defines which items are
 Filter which marks items which generates a warning state.
 If anything matches this filter the return status will be escalated to warning.
 
+*Example:* `warning="line LIKE 'WARN'"`
+
 
 
 <h5 id="check_logfile_critical">critical:</h5>
 
 Filter which marks items which generates a critical state.
 If anything matches this filter the return status will be escalated to critical.
 
+*Example:* `warning="line LIKE 'ERROR'"`
+
 
 
 <h5 id="check_logfile_ok">ok:</h5>
@@ -185,6 +189,9 @@ In other words if one file contains an error the entire check will result in err
 
 
 <a name="check_logfile_filter_keys"/>
+
+The following keywords may be used to write a [filter expression](/checks/#expressions).
+
 #### Filter keywords