Citrix Systems Network Router 9.2 User Manual

In this expression, the following is the operator component:

eq("text/html")

This operator causes the NetScaler to evaluate any HTTP requests that 
contain a Content-Type header, and in particular, to determine if the value 
of this header is equal to the string text/html.

•

<compound-operator> is a Boolean or arithmetic operator that forms a 
compound expression from multiple prefix or prefix.operation elements.

For example, consider the following expression:

http.req.header("Content-Type").eq("text/html") && 

http.req.url.contains(".html")

An expression prefix represents a discrete piece of data. For example, an 
expression prefix can represent an HTTP URL, an HTTP Cookie header, or a 
string in the body of an HTTP POST request. An expression prefix can identify 
and return a wide variety of data types, including the following: 

•

A client IP address in a TCP/IP packet

•

NetScaler system time

•

An external callout over HTTP

•

A TCP or UDP record type

In most cases, an expression prefix begins with one of the following keywords: 

•

: Identifies a characteristic of the client that is either sending a 

request or receiving a response, as in the following examples:

•

The prefix client.ip.dst designates the destination IP address 
in the request or response. 

•

The prefix client.ip.src designates the source IP address.

•

: Identifies an element in an HTTP request or a response, as in the 

following examples:

•

The prefix http.req.body(integer) designates the body of 
the HTTP request as a multiline text object, up to the character 
position designated in integer. 

•

The prefix http.req.header(

"

"

) 

designates 

an HTTP header, as specified in header_name.