Editing Agrep

{{lowercase|title=agrep}}
{{Infobox software
| name                   = agrep
| logo                   = <!-- Image name is enough -->
| logo caption           = 
| logo_size              = 
| logo_alt               = 
| screenshot             = <!-- Image name is enough -->
| caption                = 
| screenshot_size        = 
| screenshot_alt         = 
| collapsible            = 
| developer              = {{Plainlist|
* [[Udi Manber]]
* Sun Wu
}}
| released               = {{Start date and age|1988}}
| discontinued           = 
| latest release version = 3.41.5
| latest release date    = <!-- {{Start date and age|YYYY|MM|DD|df=yes/no}} -->
| latest preview version = 
| latest preview date    = <!-- {{Start date and age|YYYY|MM|DD|df=yes/no}} -->
| programming language   = C
| operating system       = {{Plainlist|
* [[Unix-like]]
* [[OS/2]]
* [[DOS]]
* [[Microsoft Windows]]
}}
| platform               = 
| size                   = 
| language               = 
| language footnote      = 
| genre                  = [[Pattern matching]]
| license                = [https://raw.githubusercontent.com/Wikinaut/agrep/master/COPYRIGHT ISC open source license]
| standard               = 
| website                = {{URL|http://www.tgries.de/agrep}}
}}
'''agrep''' (approximate [[grep]]) is an [[open-source software|open-source]] [[approximate string matching]] program, developed by [[Udi Manber]] and Sun Wu between 1988 and 1991,<ref>{{cite conference |title=Agrep -- a fast approximate pattern-matching tool |last1=Wu |first1=Sun |last2=Manber |first2=Udi |date=20–24 January 1992 |location=San Francisco, California |conference=1992 Winter USENIX Conference |citeseerx = 10.1.1.89.5424}}</ref> for use with the [[Unix]] operating system. It was later ported to [[OS/2]], [[DOS]], and [[Microsoft Windows|Windows]].

It selects the best-suited algorithm for the current query from a variety of the known fastest (built-in) [[string searching algorithm]]s, including Manber and Wu's [[bitap algorithm]] based on [[Levenshtein distance]]s.

agrep is also the [[Search engine (computing)|search engine]] in the indexer program GLIMPSE. agrep is under a free [[ISC License]].<ref>[http://webglimpse.net/sublicensing/licensing.html WebGlimpse, Glimpse and also AGREP license] since 18.09.2014 ([http://opensource.org/licenses/ISC ISC License]).</ref>

==Alternative implementations==
A more recent agrep is the command-line tool provided with the [[TRE (computing)|TRE]] regular expression library. TRE agrep is more powerful than Wu-Manber agrep since it allows weights and total costs to be assigned separately to individual groups in the pattern. It can also handle Unicode.<ref>{{cite web | title=TRE - TRE regexp matching package - Features | url=http://laurikari.net/tre/about }}</ref> Unlike Wu-Manber agrep, TRE agrep is licensed under a [[BSD licenses#BSD-style licenses|2-clause BSD-like license]].

FREJ (Fuzzy Regular Expressions for Java) open-source library provides command-line interface which could be used in the way similar to agrep. Unlike agrep or TRE it could be used for constructing complex substitutions for matched text.<ref>{{cite web | title=FREJ - Fuzzy Regular Expressions for Java - Guide and Examples | url=http://frej.sf.net/rules.html }}</ref> However its syntax and matching abilities differs significantly from ones of ordinary [[regular expression]]s.

==See also==
* [[Bitap algorithm]]
* [[TRE (computing)]]

==References==
{{Reflist}}

==External links==
* Wu-Manber agrep
**[http://www.tgries.de/agrep AGREP home page]
**[https://web.archive.org/web/20170706092701/ftp://ftp.cs.arizona.edu/agrep For Unix]  (To compile under OSX 10.8, add <code>-Wno-return-type</code> to the <code>CFLAGs  = -O</code> line in the Makefile)
*See also
**[http://laurikari.net/tre TRE regexp matching package]
**[https://web.archive.org/web/20080513225010/http://www1.bell-labs.com/project/wwexptools/cgrep/ cgrep a defunct command line approximate string matching tool]
**[http://www.dcc.uchile.cl/~gnavarro/software/ nrgrep] a command line approximate string matching tool
**[http://finzi.psych.upenn.edu/R/library/base/html/agrep.html agrep as implemented in R]

[[Category:Information retrieval systems]]
[[Category:Unix text processing utilities]]
[[Category:Software using the ISC license]]