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Brian_Kenworthy's avatar
Brian_Kenworthy
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Oct 03, 2006

Inspect URI without Case Senstivity?

Hello all,

 

 

I have created the following rule to redirect traffic based on the URI to another pool, however, I want the rule to ignore case sensitvity within the URI string. Here is my rule:

 

 

when HTTP_REQUEST {

 

set uri [HTTP::uri]

 

if { $uri matches_regex "/_xml/ORS/status.asp*" }{

 

pool mypool_B2B_SSL

 

} else {

 

pool mypool.com_SSL

 

}

 

}

 

 

If I browse using the exact snytax, everything works fine, but it I use a lower case "ors", it fails i.e. https://mydomain/_xml/ors/status.asp I want the rule to fire on any case change that a user puts into the string.

 

 

Thanks in advance for the help.

 

 

Brian
application delivery
dev
devops
iRules

3 Replies

  • Joe_Pruitt's avatar
    Joe_Pruitt
    Oct 03, 2006
    matches_regex is way overkill for a simple string comparison. Regular expressions are very CPU intensive so it's better to not use them if you don't have to.

    As for the case sensitivity, you can use the TCL "string tolower" command in your comparison. I'd go with something like this:

    when HTTP_REQUEST {
  if { [string tolower [HTTP::uri]] starts_with "/_xml/ors/status.asp" }{
    pool mypool_B2B_SSL
  } else {
   pool mypool.com_SSL
  }
}

    Hope this helps...

    -Joe
  • Brian_Kenworthy's avatar
    Brian_Kenworthy
    Icon for Nimbostratus rankNimbostratus
    Oct 03, 2006
    Thanks Joe, that did the trick!!

     

     

    One last question...I have a handful of paths to compare, so I added them to my rule with the "or" clause:

     

     

    when HTTP_REQUEST {

     

    if { [string tolower [HTTP::uri]] starts_with "/_xml/ors/status.asp"

     

    or [string tolower [HTTP::uri]] starts_with "/_xml/vendor/status.asp"

     

    or [string tolower [HTTP::uri]] starts_with "/_xml/client/status.asp" }{

     

    pool mypool_B2B_SSL

     

    } else {

     

    pool mypool.com_SSL

     

    }

     

     

    Is there any better way to write this rule to avoid redundancy? Thanks again.

     

     

  • Joe_Pruitt's avatar
    Joe_Pruitt
    Oct 03, 2006
    I prefer the switch statement myself (or a data group in combination with the matchclass command if you have a lot more strings to match.

    Here's how the switch statement would look:

    when HTTP_REQUEST {
  switch -glob [string tolower [HTTP::uri]] {
    "/_xml/ors/status.asp*" -
    "/_xml/vendor/status.asp*" -
    "_xml/client/status.asp*" {
      POOL mypool_B2B_SSL
    }
    default {
      pool mypool.com_SSL
    }
  }
}

    The -glob makes the switch perform like unix file globbing (wildcarding). This is much less expensive CPU-wise than a regular expresion check and gives you the flexibility to use wildcards in your comparisons. Note that I put a "*" at the end of the strings making it equivalent to a "starts_with" comparison.

    -Joe