Product Documentation

Sample usage

To understand the usage of pattern sets in expressions, consider the example of a pattern set named “imagetypes.”

Patterns Index value
svg 1
bmp 2
png 3
gif 4
tiff 5
jpg 6

Table 1. Pattern set “imagetypes”

Example 1: Determine whether the suffix of an HTTP request is one of the file extensions defined in the “imagetypes” pattern set.

  • Expression. HTTP.REQ.URL.SUFFIX.EQUALS_ANY(“imagetypes”)
  • Sample URL. http://www.example.com/homepageicon.jpg
  • Result. TRUE

Example 2: Determine whether the suffix of an HTTP request is one of the file extensions defined in the “imagetypes” pattern set, and return the index of that pattern.

  • Expression. HTTP.REQ.URL.SUFFIX.EQUALS_INDEX(“imagetypes”)
  • Sample URL. http://www.example.com/mylogo.gif
  • Result. 4 (The index value of the pattern “gif”.)

Example 3: Use the index value of a pattern to determine whether the URL suffix is within a specified index-value range.

  • Expression. HTTP.REQ.URL.SUFFIX.EQUALS_INDEX(“imagetypes”).GE(3) && HTTP.REQ.URL.SUFFIX.EQUALS_INDEX(“imagetypes”).LE(5)
  • Sample URL. http://www.example.com/mylogo.gif
  • Result. TRUE (The index value of gif file types is 4.)

Example 4: Implement one set of policies for file extensions bmp, jpg, and png, and a different set of policies for gif, tiff, and svg files.

An expression that returns the index of a matched pattern can be used to define traffic subsets for a web application. The following two expressions could be used in content switching policies for a content switching virtual server:

  • HTTP.REQ.URL.SUFFIX.EQUALS_INDEX(“imagetypes”).LE(3)
  • HTTP.REQ.URL.SUFFIX.EQUALS_INDEX(“imagetypes”).GE(4)

Sample usage

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