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Forum Discussion

Andrea_Arquint's avatar
Andrea_Arquint
Icon for Nimbostratus rankNimbostratus
Jun 17, 2013

using variable in a switch statement

Hi,

I would like to test a URI which is defined as a variable ($TEST_VAR):

when HTTP_REQUEST {

   set TEST_VAR "item"

   switch -glob [string tolower [HTTP::path]] {
      "/$TEST_VAR/*" {
         log local0. "Matched pool 2 paths for [HTTP::uri]"
         pool pool2
      }
      default {
         log local0. "Hit default for [HTTP::uri]"
         pool pool_default
      }
   }
}

But this does not work.

How can this be done? Is such thing possible somehow?

Thanx

bb

application delivery
dev
devops
iRules

5 Replies

  • spark_86682's avatar
    spark_86682
    Historic F5 Account
    Jun 17, 2013
    This is possible. In Tcl, curly braces prevent variable substitution, and you have a set of curly braces surrounding the entire body of your switch statement, so "/$TEST_VAR/*" won't have its variable substituted. You should be able to fix this just by removing those outer braces around your switch body: 

     
   switch -glob [string tolower [HTTP::path]]
      "/$TEST_VAR/*" {
         log local0. "Matched pool 2 paths for [HTTP::uri]"
         pool pool2
      }
      default {
         log local0. "Hit default for [HTTP::uri]"
         pool pool_default
      }
  • Andrea_Arquint's avatar
    Andrea_Arquint
    Icon for Nimbostratus rankNimbostratus
    Jun 21, 2013

    hi

     

    I did that. Removed the curly braces as you showed but I could not save the irule within irule editor.

     

    irule editor message: Response is not well-formed XML.

     

    So, Ithink this cannot be done at the moment with irules.

     

    greetins

     

  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jun 23, 2013
    If you add a \ at the end of the first line of the switch statement it should work. Here are two forms of the syntax which allow for variables in the switch cases: 

    
when RULE_INIT {

set case1 "test1"
set case2 "test2"

 Syntax version 1
switch -glob -- "test2string1" $case1 {
log local0. "matched exact \$case1: $case1"
} $case2 {
log local0. "matched exact \$case2: $case2"
} $case2* {
log local0. "matched starts_with \$case2: $case2"
} default {
log local0. "matched default case"
}

 Syntax version 2
switch -glob -- "test2string2" \
$case1 {
log local0. "matched exact \$case1: $case1"
} \
$case2 {
log local0. "matched exact \$case2: $case2"
} \
$case2* {
log local0. "matched starts_with \$case2: $case2"
} \
default {
log local0. "matched default case"
}
}

    Aaron
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    May 02, 2014

    Summarized on the switch wiki page in the last two examples... https://devcentral.f5.com/wiki/iRules.switch.ashx