Pattern matching is a basic search mechanism. The term pattern matching refers to the process of locating a specific pattern inside data.

When the pattern of data is a collection of groups of data known as a string (a series of characters that are manipulated as a unit), the pattern matching is called string matching. The location of a certain string having a certain length in a text of much longer length is an example of string matching.

A variety of search formulas, or algorithms, has been devised for string matching. These algorithms make use of a process known as hashing. In hashing, a number, also called a hash, is generated from a string via one of the devised formulas. The mathematical derivation process renders it unlikely that some other string will produce the same value. The number and its corresponding string form an index, called...