Picking Up Perl - Regular Expressions Go to the first , previous , next , last section, table of contents . To remedy that, this chapter is devoted completely to regular expressions.
All Regular expressions are a concept borrowed from automata theory.
The term, language , when used in the sense borrowed from automata theory, can be a bit confusing. For the regular expression to have meaning, this set of possible strings that we are defining should have some meaning to us. Regular expressions give us extreme power to do pattern matching on text documents. We can use the regular expression syntax to write a succinct description of the entire, infinite class of strings that fit our specification. In addition, anyone else who understands the description language of regular expressions, can easily read out description and determine what set of strings we want to match.