Appendix E: Filter File Syntax
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• The only condition available in filter lines is the acl= condition, which is a synonym for the CPL
condition client.address=.
• The only way to specify case-sensitivity is with case_insensitive={yes|no}.
The following are requirements for filter lines:
• A line break is considered to be a new filter line.
• Each line lists a unique URL.
• Comment lines begin with a semicolon (;).
• The maximum length of a line is 4096 bytes.
Important: If you include a period at the beginning of the domain name in a filter, it might not
produce the expected match, for example, .company.com will not match company.com.
This also holds true for filters that specify only the ending part of the domain name; for
example, org works as expected, but .org does not work as you might expect. If you are
using a regular-expression pattern for the filter, a period can be matched by using "\." For
more information about using regular expressions, refer to Appendix E: “Using Regular
Expressions,” in the ProxySG Configuration and Management Guide.
Conditions
In CacheOS 4.x filter files, the only condition is the acl= condition. This condition can be used in a
filter line to test the IP address of the client. The expression can include an IP address or subnet, or the
label of a define acl definition block. (In CPL, this condition is deprecated; use the synonym
client.address= condition along with the define subnet definition block.)
acl={ip_address|acl_label}
where :
•ip_address —The client IP address or subnet; for example, 10.1.198.0.
•subnet_label—Label of a define ACL definition block that binds a number of IP addresses or
subnets.
Properties
Properties in filter files take the following general form: property=value. The following table lists the
property settings that are available.
Table F.1: Properties available in CacheOS 4.x filter files
Property Value Description
always_verify yes | no When set to yes, acts as the equivalent of
always-verify-source configurable through caching settings,
but on a per-URL basis instead of globally. A verification is
performed with the origin server for every request matching the
filter. If there are multiple simultaneous accesses of an object, the
requests are reduced to a single request to the origin server.
advertisement yes | no When set to yes, cache objects at this URL, and request the objects in
the background to maintain the hit count.