iRule to overwrite Page Extension help!

In addition to nmenant's example, here are a couple more options:

Here is a version which looks for any two to four character extension in all caps and sets it to lower case:

when HTTP_REQUEST {
    Get the path (/path/to/file.ext)
      Use URI::basename to get the filename and extension (file.ext).
      Use getfield to split on the period, getting only the extension (ext).
      Prepend a period back to make the string more specific.
   set file_extension .[getfield [URI::basename [HTTP::path]] . 2 ]
    Log the parsed file extension
   log local0. "Original file extension: $file_extension"
    For two to four letter capitalized extensions, update the path with the lower case extension.
   switch -glob $file_extension {
      .[A-Z][A-Z] -
      .[A-Z][A-Z][A-Z] -
      .[A-Z][A-Z][A-Z][A-Z] {
          Set extension to lowercase
         set file_extension_lowered [string tolower $file_extension]
          Update the path by replacing the original file extension with the lowered case version
         HTTP::path [string map "$file_extension $file_extension_lowered" [HTTP::path]]
          Log the updated path (this should be removed when you're done testing).
         log local0. "Updated path: [string map "$file_extension $file_extension_lowered" [HTTP::path]]"
      }
   }
}

If you only wanted to update .JSP or any other mixed case of .jsp to .jsp, you could simplify the rule:

when HTTP_REQUEST {
   HTTP::path [string map -nocase {.jsp .jsp} [HTTP::path]]
}

The second of the two options would be more efficient.

Aaron