These tools and utilities have regular expressions as the core of their functionality.

grep - The utility from the UNIX world that first made regular expressions popular

General Applications with Notable Support for Regular Expressions

There are a lot of applications these days that support regular expressions in one way or another, enhancing certain part of their functionality. But certain applications stand out from the crowd by implementing a full-featured Perl-style regular expression flavor and allowing regular expressions to be used instead of literal search terms throughout the application.

Programming Languages and Libraries

If you are a programmer, you can save a lot of coding time by using regular expressions. With a regular expression, you can do powerful string parsing in only a handful lines of code, or maybe even just a single line. A regex is faster to write and easier to debug and maintain than dozens or hundreds of lines of code to achieve the same by hand.

Boost - Free C++ source libraries with comprehensive regex support that was later standardized by C++11. But there are significant differences in Boost’s regex flavors and the flavors in std::regex implementations.

Delphi - Delphi XE and later ship with RegularExpressions and RegularExpressionsCore units that wrap the PCRE library. For older Delphi versions, you can use the TPerlRegEx component, which is the unit that the RegularExpressionsCore unit is based on.

Gnulib - Gnulib or the GNU Portability Library includes many modules, including a regex module. It implements both POSIX flavors, as well as these two flavors with added GNU extensions.

Groovy - Groovy uses Java’s java.util.regex package for regular expressions support. Groovy adds only a few language enhancements that allow you to instantiate the Pattern and Matcher classes with far fewer keystrokes.

Java - Java 4 and later include an excellent regular expressions library in the java.util.regex package.

JavaScript - If you use JavaScript to validate user input on a web page at the client side, using JavaScript’s built-in regular expression support will greatly reduce the amount of code you need to write.

.NET (dot net) - Any .NET-based programming language such as C# (C sharp) or VB.NET can use .NET’s excellent support for regular expressions.

PCRE - Popular open source regular expression library written in ANSI C that you can link directly into your C and C++ applications, or use through an .so (UNIX/Linux) or a .dll (Windows).

Perl - The text-processing language that gave regular expressions a second life, and introduced many new features. Regular expressions are an essential part of Perl.

PHP - Popular language for creating dynamic web pages, with three sets of regex functions. Two implement POSIX ERE, while the third is based on PCRE.

POSIX - The POSIX standard defines two regular expression flavors that are implemented in many applications, programming languages and systems.

PowerShell - PowerShell is a programming language from Microsoft that is primarily designed for system administration. Since PowerShell is built on top of .NET, it’s built-in regex operators -match and -replace use the .NET regex flavor. PowerShell can also access the .NET Regex classes directly.

Python - Popular high-level scripting language with a comprehensive built-in regular expression library

R - The R Language is the programming languages used in the R Project for statistical computing. It has built-in support for regular expressions based on POSIX and PCRE.

Ruby - Another popular high-level scripting language with comprehensive regular expression support as a language feature.

std::regex - Regex support part of the standard C++ library defined in C++11 and previously in TR1.

Tcl - Tcl, a popular “glue” language, offers three regex flavors. Two POSIX-compatible flavors, and an “advanced” Perl-style flavor.

VBScript - Microsoft scripting language used in ASP (Active Server Pages) and Windows scripting, with a built-in RegExp object implementing the regex flavor defined in the JavaScript standard.

Visual Basic 6 - Last version of Visual Basic for Win32 development. You can use the VBScript RegExp object in your VB6 applications.

wxWidgets - Popular open source windowing toolkit. The wxRegEx class encapsulates the “Advanced Regular Expression” engine originally developed for Tcl.

XML Schema - The W3C XML Schema standard defines its own regular expression flavor for validating simple types using pattern facets.

Xojo - Cross-platform development tool formerly known as REALbasic, with a built-in RegEx class based on PCRE.

XQuery and XPath - The W3C standard for XQuery 1.0 and XPath 2.0 Functions and Operators extends the XML Schema regex flavor to make it suitable for full text search.

XRegExp - Open source JavaScript library that enhances the regex syntax and eliminates many cross-browser inconsistencies and bugs.

Databases

Modern databases often offer built-in regular expression features that can be used in SQL statements to filter columns using a regular expression. With some databases you can also use regular expressions to extract the useful part of a column, or to modify columns using a search-and-replace.

MySQL - MySQL’s REGEXP operator works just like the LIKE operator, except that it uses a POSIX Extended Regular Expression.

Oracle - Oracle Database 10g adds 4 regular expression functions that can be used in SQL and PL/SQL statements to filter rows and to extract and replace regex matches. Oracle implements POSIX Extended Regular Expressions.

PostgreSQL - PostgreSQL provides matching operators and extraction and substitution functions using the “Advanced Regular Expression” engine also used by Tcl.