In the computing world there are regular expressions which are used to provide a flexible and concise way to match strings of text like specific words, characters, or character patters. These regular expressions, or Regex, are written in a formal language and can be interpreted by a normal expression processor. An expression processor program can help to examine text and indentify the characters that match the any provided specifications.
A regular expression is also known as a pattern and is used to describe sets of strings. Many times they are used to provide a concise description of a block of code without having to list each element. For example, a set that contains three strings “Haendel”, “Handel”, “Händel” can be interpreted through the pattern H (ä|ae?)ndel. Alternatively, it can be described in away so that the pattern matches each of the three strings.
Regular Expressions are used by many programming languages, utilities, and text editors to manipulate and search for text based on patters. One example of Regular Expressions (Regex) in programming is if a comment appears inside a coded string, the comment ‘regex’ will interpret the text in the string as a comment. Most scripting languages like Tcl, Ruby, Awk, and Perl have Regex engines already built into their scripts.
Regular expressions are very useful when manipulating source code in a Regex processing tool or text editor. The majority of programming languages have similar constructs like strings, comments, and keywords. However, there are some subtle differences that can make it difficult to find the proper Regex. Programmers should learn the various Regex definitions when writing codes and scripts. It is important to remember that various scripts have different Regex interpretations, so the programmer should research for the exact script he/she is dealing in. If they are programming in Pearl or Ruby, then they should find the exact Ruby or Pearl Regex syntax.