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BaltoStar_12467's avatar
BaltoStar_12467
Mar 07, 2015

BIG-IP : iRule test that variable exists and has certain value

F5 BIG-IP Virtual Edition v11.4.1 (Build 635.0) LTM on ESXi What is the simplest most elegant syntax to test that a variable exists and has a certain value ? For example if I want to determine t...
application delivery
design
devops
irule
iRules
LTM
variable
Michael_Jenkins's avatar
Michael_Jenkins
Icon for Cirrostratus rankCirrostratus
Mar 07, 2015

You'll need to use 

[info exists myvariable]
(without the 
$
) to check for variable existence. Then you would do your other conditional check.

So like this in your example

when HTTP_REQUEST {
    set myvariable 0
     conditional processing ...

    set myvariable 1
     more processing ... 
    if {[info exists myvariable] && ($myvariable equals "1")} {
         do something
    }
}

If you know that your variable is going to be an integer, you could just use 

$myvariable
instead of 
($myvariable equals "1")
as it will return a true value for any positive value.