Citrix Systems 9.2 manual Or a response. This operation returns the header that, MyHeader abc\r\n

Chapter 6 Advanced Expressions: Parsing HTTP, TCP, and UDP Data 125

Operations That Evaluate HTTP Headers

HTTP Header Operation	Description
http header.	An HTTP header can occur multiple times in a request
INSTANCE(instance	or a response. This operation returns the header that
number)	occurs instance number of places before the final
	instance. For example, instance(0) selects the last
	instance of the current type, instance(1) selects the
	next-to-last instance, and so on. This prefix cannot be
	used in bidirectional policies.
	The instance number argument cannot exceed 14.
	Following is an example of a request with two headers:
	HTTP/1.1 200 OK\r\n
	MyHeader: abc\r\n
	Content-Length: 200\r\n
	MyHeader: def\r\n
	\r\n
	The following returns a text object that refers to
	"MyHeader: abc\r\n":
	http.res.header("MyHeader").instance(1)
http header.	Extracts the text that matches the string argument. The
SUBSTR("string")	headers are evaluated from the last instance to the first.
	Following is an example of a request with two headers
	that contain the string “111”:
	HTTP/1.1 200 OK\r\n
	MyHeader: abc111\r\n
	Content-Length: 200\r\n
	MyHeader: 111def\r\n
	\r\n
	The following returns "111" from the last instance of
	MyHeader. This is the header with the value "111def".
	http.res.header("MyHeader").
	substr("111")