| agrep | |
|---|---|
| Developer(s) | 
  | 
| Initial release | 1988 | 
| Stable release | 3.41.5      | 
| Repository | |
| Written in | C | 
| Operating system | |
| Type | Pattern matching | 
| License | ISC open source license | 
| Website |  www | 
agrep (approximate grep) is an open-source approximate string matching program, developed by Udi Manber and Sun Wu between 1988 and 1991, [1] for use with the Unix operating system. It was later ported to OS/2, DOS, and Windows.
It selects the best-suited algorithm for the current query from a variety of the known fastest (built-in) string searching algorithms, including Manber and Wu's bitap algorithm based on Levenshtein distances.
agrep is also the search engine in the indexer program GLIMPSE. agrep is under a free ISC License. [2]
A more recent agrep is the command-line tool provided with the 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. [3] Unlike Wu-Manber agrep, TRE agrep is licensed under a 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. [4] However its syntax and matching abilities differs significantly from ones of ordinary regular expressions.
-Wno-return-type to the CFLAGs  = -O line in the Makefile)