syslog-ngfilter

本文介绍了Syslog-ng中过滤器的功能及配置方法。 通过过滤器可以在Syslog-ng中实现日志消息的精细控制，包括如何定义过滤器、使用布尔表达式及正则表达式进行复杂条件筛选等。

Filters are expressions to select, or in other words, filter log messages. They make sure that the right messages reach the right destinations. For example, you can use filters to discard debug level log messages, or make sure that all authentication-rela

As this was not possible on either the firewall or Splunk, I now send the firewall logs to a syslog-ng server which filters out the unwanted messages and forwards the rest of the logs to Splunk via Splunk-forwarder.

This section will guide you through the process of creating a filter function, by going through the files of filter-length, a set of filter functions which filter log messages based on the length of their $ MESSAGE}. $ MESSAGE} refers to the syslog-ng OSE

syslog-ng作為 syslog 的替代 工具，可以完全替代syslog的服務，並且通過定義規則，實現更好的過濾功能。

在这个Syslog-ng示例中，过滤器 f_syslog 定义了只有来自 user 设施且优先级在 debug 到 warning 之间的消息会被处理。 通过上述方法，你可以根据实际需求设置Syslog的过滤规则，以便更有效地管理和分析日志文件。