Tool to search (or test) in a text, a message, or a document by regular expression / rational expression and extract matching substrings.
Regular Expression Search - dCode
Tag(s) : Data Processing
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Regular Expression Search
Regexp Search in a Text
Answers to Questions (FAQ)
What is a regular expression?
A regular expression (or rational expression or regexp) is a string that describes a set of other possible strings in a precise syntax, and is used in computing for search, editing and text control.
Example: a(b|c)[a-z]{3}describes a set of 5 letters beginning with a, followed by b or c and 3 other letters between a and z, in small caps
Example: [0-9]{2}!? describes a set of 2-digit numbers from 00 to 99 followed or not by an exclamation mark
What are the most common regular expressions?
Regular expressions depend heavily on the type of text to be processed:
Lower case name: [a-z0-9_-]{3,16}
Date dd/mm/yyyy: \d{1,2}\/\d{1,2}\/\d{4}
Hexadecimal color: #?([A-Fa-f0-9]){3}(([A-Fa-f0-9]){3})?
E-mail address: [a-z0-9_\.-]+)@([\da-z\.-]+)\.([a-z\.]{2,6}
Internet address:https?:\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?
IP address: (?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)
Source code
dCode retains ownership of the "Regular Expression Search" source code. Any algorithm for the "Regular Expression Search" algorithm, applet or snippet or script (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, breaker, translator), or any "Regular Expression Search" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) or any database download or API access for "Regular Expression Search" or any other element are not public (except explicit open source licence like Creative Commons). Same with the download for offline use on PC, mobile, tablet, iPhone or Android app.
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In a scientific article or book, the recommended bibliographic citation is: Regular Expression Search on dCode.fr [online website], retrieved on 2025-04-15,
