Citrix Systems Network Router 9.2 Benutzerhandbuch

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The prefix http.req.url designates an HTTP URL in URL-
encoded format.

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: Identifies an element in the server that is either processing a 

request or sending a response.

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: Identifies a characteristic of the NetScaler that is processing the 

traffic.

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Represents all the strings that result from a search in the target 

text. This prefix can be used only in the string expression that specifies 
replacement text in a rewrite action. The expression that is used to search 
the target text must be a regular expression, and the type of action must be 
REPLACE_ALL

, INSERT_AFTER_ALL, or INSERT_BEFORE_ALL. 

Any operator that is used with the TARGET prefix operates on all the 
strings that are found in the target text. 

For example, if a search that uses a regular expression finds n occurrences 
of the specified string, and if the action type is REPLACE_ALL, the 
expression TARGET.TO_UPPER changes the case of all n occurrences of 
the string to upper case.

DNS policies support only SYS, CLIENT, and SERVER objects.

In addition, in the Access Gateway, the Clientless VPN function can use the 
following types of prefixes:

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: Identifies any text element in a request or a response.

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: Identifies the target of a connection.

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: Identifies an element in the URL portion of an HTTP request or 

response.

As a general rule of thumb, any expression prefix can be a self-contained 
expression. For example, the following prefix is a complete expression that 
returns the contents of the HTTP header specified in the string argument 
(enclosed in quotation marks): 

http.res.header.("myheader") 

Or you can combine prefixes with simple operations to determine TRUE and 
FALSE values. For example, the following returns a value of TRUE or FALSE:

http.res.header.("myheader").exists 

You can also use complex operations on individual prefixes and multiple prefixes 
within an expression, as in the following example:

http.req.url.length + http.req.cookie.length <= 500