$not
If value is “true”, it returns “false”. If value is “false”, it returns “true”.
Syntax:
$not( value )
Parameters:
value – it indicates true or false
Returns:
true – if the value is false
false – if the value is true
Version Since:
2.2
Where the function can be used:
- Preliminary rules
- Regular rules
Examples:
$not( $localhost ) = true
If the packet is not sent from localhost. It is same as the following definition.
$localhost = false