Patent ID: 7225188

Claim:
A method for operating a pattern matching engine having a plurality of information storage entries with two or more regular expressions, each regular expression including a plurality of characters and each regular expression associated with a corresponding action to be applied when matching strings are found, the method comprising the steps of: identifying one or more borders within each regular expression, the one or more borders separating the regular expression into a plurality of sub-expressions, each sub-expression having a plurality of sequential characters; loading each entry of the plurality of entries of the pattern matching engine with the plurality of the sequential characters from one of the sub-expressions of the plurality of sub-expressions, wherein the borders are defined by a predetermined sequence of regular expression metacharacters, and the entries stored in content addressable memory (CAM); applying a string from a network message to the entries of the pattern matching engine to search the string simultaneously in parallel for sub-expressions from each of the two or more regular expressions; determining that the sub-expressions of at least one regular expression match the string; and executing the corresponding action associated with that at least one regular expression on the network message.