Scan - Making string manipulation efficient

One of the many things that makes iRules so powerful is the ability to inspect data and break it up into custom variables. You can store whatever information you need in your desired format and put i...
Published Apr 24, 2008
Version 1.0
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Al_Carandang_11's avatar
Al_Carandang_11
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May 21, 2008
There is a slight problem with your example

 

 

scan [HTTP::host] %s.%s.%s prefix host suffix

 

 

Since %s reads in all characters until the next whitespace, the whole [HTTP::host] string ends up in the variable 'prefix' and nothing is left to store in the succeeding variables. In addition, rather than setting these other variables to empty strings, they don't get defined at all so any succeeding reference to them generates a TCL error. The following would work

 

 

scan [HTTP::host] %\[^.\].%\[^.\].%s prefix host suffix