RSyslog Documentation

exists()

Purpose

exists($!path!varname)

This function checks if the specified variable exists, in other words: contains a value. A variable that once was set and later on unset does also not exist.

The function accepts a single argument, which needs to be a variable. It returns 0 if the variable does not exist and 1 otherwise. The function can be combined with any other expression to form more complec expressions.

New in version 8.2010.10.

Example

if exists(!$path!varname) then ...
if not exists($.local!var) then ...
if exists($!triggervar) and $msg contains "something" then ...

See also

Help with configuring/using Rsyslog:

  • Mailing list - best route for general questions
  • GitHub: rsyslog source project - detailed questions, reporting issues that are believed to be bugs with Rsyslog
  • Stack Exchange (View, Ask) - experimental support from rsyslog community

See also

Contributing to Rsyslog:

Copyright 2008-2020 Rainer Gerhards (Großrinderfeld), and Others.

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