A regular expression (regex) engine is a software program that is used to interpret and execute regular expressions. A regular expression is a sequence of characters that defines a search pattern, mainly for use in pattern matching with strings, or string matching, i.e "find and replace"-like operations.
The regex engine takes in a regular expression as input, along with a string or set of strings to be searched. It then applies the search pattern defined by the regular expression to the input string, and returns a result indicating whether or not the pattern was found in the input.
Regex engines are used in a wide variety of contexts, including text editors, command line utilities, programming languages, and many other applications that need to search, extract, or modify text data. They are a powerful tool for working with text and are widely used in data processing, data validation, and data manipulation tasks....