cMatchExpression Class Reference¶

Decides whether an object matches an expression.

Objects must implement, or be wrapped into an instance of, cMatchExpression::Matchable to be used with this class. Fields of the object will be queried via methods of Matchable.

Matches various fields of an object. By default, a pattern must match the "default field" of the object, which will usually be its name. Other fields can be matched with the <fieldname> =~ <pattern> syntax. These elements can be combined with the AND, OR, NOT operators, accepted in both lowercase and uppercase. AND has higher precedence than OR, and parentheses can be used to change the evaluation order.

Patterns are those accepted by cPatternMatcher, that is, *, ?, character ranges as {a-z}, numeric ranges as {0..999}, or bracketed numeric ranges as [0..999] (e.g. *[90..100] matching foo[95]) are accepted.

Field names and patterns that do not contain whitespace, a left or right parenthesis or the =~ sequence can be written without quotation marks. When a field name or pattern is enclosed in quotation marks, it is interpreted similar to a string constant in C/C++ regarding the use of backslashes, i.e. \t becomes a tab, \\ a single backslash, etc.