Citrix Systems 9.2 Booleans in Compound Expressions, Parentheses in Compound Expressions, Compound Operations for Strings

46 Citrix NetScaler Policy Configuration and Reference Guide
You can use parentheses to control the order of evaluation in a compound
expression.
Booleans in Compound Expressions
You configure compound expressions with the following operators:
•&&. This operator is a logical AND. For the expression to evaluate to
TRUE, all components that are joined by the And must evaluate to TRUE.
Following is an example:
http.req.url.hostname.eq("myHost") &&
http.req.header("myHeader").exists
• ||. This operator is a logical OR. If any component of the expression that is
joined by the OR evaluates to TRUE, the entire expression is TRUE.
•!. Performs a logical NOT on the expression.
In some cases, the NetScaler configuration utility offers AND, NOT, and OR
operators in the Add Expression dialog box. However, these are of limited use.
Citrix recommends that you use the operators &&, ||, and ! to configure
compound expressions that use Boolean logic.
Parentheses in Compound Expressions
You can use parentheses to control the order of evaluation of an expression. The
following is an example:
http.req.url.contains("myCompany.com") ||
(http.req.url.hostname.eq("myHost") &&
http.req.header("myHeader").exists)
The following is another example:
(http.req.header("Content-Type").exists &&
http.req.header("Content-Type").eq("text/html")) ||
(http.req.header("Transfer-Encoding").exists ||
http.req.header("Content-Length").exists)
Compound Operations for Strings
The following table describes operators that you can use to configure compound
operations on string data.
String-Based Operations for Compound Advanced Expressions
All string operations
Operations that produce a string value