Citrix Systems 9.2 manual Prefixes for Cache-Control Headers, Operations for Cache-Control Headers

126Citrix NetScaler Policy Configuration and Reference Guide

Operations That Evaluate HTTP Headers

HTTP Header Operation	Description
http header.	An HTTP header can occur multiple times in a request
VALUE(instance number)	or a response. VALUE(0) selects the value in the last
	instance, VALUE(1) selects the value in the next-to-
	last instance, and so on. 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 "abc\r\n":
	http.res.header("MyHeader").value(1)

Prefixes for Cache-Control Headers

The following prefixes apply specifically to Cache-Control headers.

Prefixes That Extract Cache-Control Headers

HTTP Header Prefix	Description
HTTP.REQ.CACHE_CONTROL	Returns a Cache-Control header in an HTTP
	request.
HTTP.RES.CACHE_CONTROL	Returns a Cache-Control header in an HTTP
	response.

Operations for Cache-Control Headers

You can apply any of the operations for HTTP headers to Cache-Control headers. For more information, see “Operations for HTTP Headers,” on page 122.