Blue Coat Systems Time Clock Proxy SG Manuale Utente
Chapter 3:
Condition Reference
A condition is an expression that yields true or false when evaluated. Conditions can appear in:
•
Policy rules.
•
Section and layer headers, as guards; for example,
[Rule] group=(“bankabc\hr” || “cn=humanresources,ou=groups,o=westernnational”)
•
define condition
,
define domain condition
, and
define prefix
condition
definition
blocks.
Condition Syntax
A condition has the following form:
trigger=pattern-expression
A trigger is the name of a condition variable. It can be simple, such as
url
, or it can contain sub-object
specifiers and modifiers, as in
url.path.case_sensitive
or
request.header.Cookie
.
A trigger
cannot contain white space.
A pattern expression can be either:
•
A simple pattern, which is matched against the trigger value.
•
A Boolean combination of simple patterns, or a parenthesized, comma-separated list of simple
patterns.
patterns.
A pattern expression can be any of the following:
•
String: A string argument must be quoted if it contains whitespace or other special characters. An
example condition expression is
example condition expression is
category=”self help”
.
•
Single argument: Conditions such as
live=
take only a single argument, in this case,
yes
or
no
.
•
Boolean expressions: Conditions such as
server_url.scheme=
can list one or more arguments
together with Boolean operators; for example,
server_url.scheme=!http
.
•
Integer or range of integers: Numeric conditions can use Boolean expressions and double periods
(
(
..
), meaning an inclusive numeric range. Numeric ranges cannot use whitespace. The
minute=
condition is used to show examples of ranges:
❐
minute=10..40—
From 10 minutes to 40 minutes after the hour.
❐
minute=10..—
From 10 minutes after the hour to the end of the hour.
❐
minute=..40—
From the beginning of the hour to 40 minutes after the hour.
❐
minute=40..10
—From 40 minutes after the hour, to 10 minutes after the next hour.
•
Regular expressions: Some header-related conditions and two URL-related conditions take regular
expressions. For more information about writing regular expressions, refer to Appendix E: “Using
Regular Expressions,” in the Blue Coat ProxySG Configuration and Management Guide.
expressions. For more information about writing regular expressions, refer to Appendix E: “Using
Regular Expressions,” in the Blue Coat ProxySG Configuration and Management Guide.
The following is Backus-Naur Form (BNF) grammar: