Chapter 3 Configuring Advanced Expressions: Getting Started 45
The following table summarizes a few of the available types of operations.
Compound Advanced Expressions
You can configure an advanced expression that contains Boolean or arithmetic
operators and multiple atomic operations. The following compound expression
contains a boolean AND:
http.req.hostname.eq("mycompany.com") && http.req.method.eq(post)
The following expression adds the value of two targets, and compares the result
to a third value:
http.req.url.length + http.req.cookie.length <= 500
A compound expression can contain any number of logical and arithmetic
operators. The following expression evaluates the length of an HTTP request on
the basis of its URL and cookie, evaluates text in the header, and performs a
Boolean AND on these two results:
http.req.url.length + http.req.cookie.length <= 500 &&
http.req.header.contains("some text")
GT(<integer>) An object's value is greater than a particular value. Following is
an example:
http.req.content_length.gt(5)
Basic Types of Operations
Operation Type Description
Text operations Match individual strings and sets of strings with any portion
of a target. The target can be an entire string, the start of a
string, or any portion of text in between the start and the end
of the string.
For example, you can extract the string "XYZ" from
"XYZSomeText". Or, you can compare an HTTP header
value with an array of different strings.
You can also transform text into another type of data.
Following are examples:
• Transform a string into an integer value
• Create a list from the query strings in a URL
• Transform a string into a time value
Numeric operations Numeric operations include applying arithmetic operators,
evaluating content length, the number of items in a list,
dates, times, and IP addresses.
Basic Operations for Expressions
Operation Determines whether or not