Short for a regular expression, a regex is a string of text that allows you to create patterns that help match, locate, and manage text. Perl is a great example of a programming language that utilizes regular expressions. However, it's only one of the many places you can find regular expressions. Regular expressions can also be used from the command line and in-text editors to find text within a file.
RegEx allows us to check for patterns in text strings such as trying to match a valid email address or password. One of the great superpowers of RegEx is being able to define your own search criteria for a pattern to fit your needs, and it is like a language of its own.
Regular expression
A regular expression is a sequence of characters that define a search pattern. Usually, such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. It is a technique developed in theoretical computer science and formal language theory.
What is regex used for?
Short for a regular expression, a regex is a string of text that allows you to create patterns that help match, locate, and manage text. Perl is a great example of a programming language that utilizes regular expressions. However, it is only one of the many places you can find regular expressions.
Result
In computing, a regular expression provides a concise and flexible means to "match" (specify and recognize) strings of text, such as particular characters, words, or patterns of characters. Common abbreviations for "regular expression" include regex and regexp. A regular expression is written in a formal language that can be interpreted by a regular expression processor, which is a program that either serves as a parser generator or examines text and identifies parts that match the provided specification. The concept of regular expressions was first popularized by utilities provided by Unix distributions, in particular, the editor ed and the filter grep. Historically, the concept of regular expressions is associated with Kleene's formalism of regular sets, introduced in the 1950s.
Other Options
TEST Search for the specified value and return true or false depending on the result
EXEC Search for a specified value and return the text of the found results
SELECT Highlight matching text
GREP Print lines matching the pattern
REVERSE GREP Print lines not matching the pattern
MODIFY ORIGINAL Show changes in the input window
SHOW ORIGINAL Display source text
