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diff --git a/doc/rsyslog_conf_nomatch.html b/doc/rsyslog_conf_nomatch.html new file mode 100644 index 00000000..5f25f3e4 --- /dev/null +++ b/doc/rsyslog_conf_nomatch.html @@ -0,0 +1,48 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html><head><title>nomatch mode - property replacer - rsyslog.conf</title></head> +<body> +<h1>nomatch mode - property replacer - rsyslog.con</h1> +<p>This is a part of the <a href="rsyslog_conf.html">rsyslog.conf documentation</a> +of the <a href="property_replacer.html">property replacer</a>.</p> +<p><b>The "nomatch-Mode" specifies which string the property replacer +shall return if a regular expression did not find the search string.</b>. Traditionally, +the string "**NO MATCH**" was returned, but many people complained this was almost never useful. +Still, this mode is support as "<b>DFLT</b>" for legacy configurations. +<p>Three additional and potentially useful modes exist: in one (<b>BLANK</b>) a blank string +is returned. This is probably useful for inserting values into databases where no +value shall be inserted if the expression could not be found. +<p>A similar mode is "<b>ZERO</b>" where the string "0" is returned. This is suitable +for numerical values. A use case may be +that you record a traffic log based on firewall rules and the "bytes transmitted" counter +is extracted via a regular expression. If no "bytes transmitted" counter is available +in the current message, it is probably a good idea to return an empty string, which the +database layer can turn into a zero. +<p>The other mode is "<b>FIELD</b>", in which the complete field is returned. This may be useful +in cases where absense of a match is considered a failure and the message that triggered +it shall be logged. +<p>If in doubt, <b>it is highly suggested to use the +<a href="http://www.rsyslog.com/tool-regex">rsyslog online regular expression +checker and generator</a> to see these options in action</b>. With that online tool, +you can craft regular expressions based on samples and try out the different modes. + +<h2>Summary of nomatch Modes</h2> +<table border="1" cellspacing="0"> +<tr><td><b>Mode</b></td><td><b>Returned</b></td></tr> +<tr><td>DFLT</td><td>"**NO MATCH**"</td></tr> +<tr><td>BLANK</td><td>"" (empty string)</td></tr> +<tr><td>ZERO</td><td>"0"</td></tr> +<tr><td>FIELD</td><td>full content of original field</td></tr> +<tr><td> </td><td><a href="http://www.rsyslog.com/tool-regex">Interactive Tool</a></td></tr> +</table> +<p>[<a href="manual.html">manual index</a>] +[<a href="rsyslog_conf.html">rsyslog.conf</a>] +[<a href="http://www.rsyslog.com/">rsyslog site</a>]</p> +<p><font size="2">This documentation is part of the +<a href="http://www.rsyslog.com/">rsyslog</a> project.<br> +Copyright © 2008 by <a href="http://www.gerhards.net/rainer">Rainer Gerhards</a> and +<a href="http://www.adiscon.com/">Adiscon</a>. Released under the GNU GPL +version 2 or higher.</font></p> +</body> +</html> + + |