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Vedio_315956's avatar
Vedio_315956
Icon for Nimbostratus rankNimbostratus
Mar 31, 2017

Substring syntax in iRules

if { [string length [substr [HTTP::uri] 0 "?"]] > 0 }   IN an above statement I can't able to understand what is the purpose of [ Substr 0 "?" ].   give some suggestion or basic idea about that...
application delivery
iRules
LTM
Hectorm's avatar
Hectorm
Icon for Nimbostratus rankNimbostratus
Mar 31, 2017

looking at your rule if{[string length [substr {HTTP::uri] 0 "?"]]>0} this rule is always going to be true since the first character on a HTTP::uri is always "/" therefore the string lengh will always be greater than 0 may be you want to do if{[string length [substr {HTTP::uri] 1 "?"]]>0} this will start the string length after the first character of HTTP::uri which is always "/"

 

set VAR1 "/downloads/hector/file1?V12" set VAR2 [substr [VAR1] 0 "?"]

 

VAR2 will be equal to /downloads/hector/file1 the substr command will start at the beginning and will end when the "?" is matched another example

set VAR3 "/downloads/hector/fil?v13?hello" set VAR4 [substr [VAR1] 0 "?"]

 

VAR3 is equal to /downloads/hector/fil

set VAR5 [[substr [VAR1] 5 "?"]

 

VAR5 is equal loads/hector/fil the substr