Random Text generator based on regex [duplicate]

regex

I would like to know if there is software that, given a regex and of course some other constraints like length, produces random text that always matches the given regex. Thanks

Solution 1:

Xeger is capable of doing it:

String regex = "[ab]{4,6}c";
Xeger generator = new Xeger(regex);
String result = generator.generate();
assert result.matches(regex);

Solution 2:

Yes, there exists software that can generate a random match to a regex:

Exrex, Python
Pxeger, Javascript
regex-genex, Haskell
Xeger, Java
Xeger, Python
Generex, Java
rxrdg, C#
String::Random, Perl
regldg, C
paggern, PHP
ReverseRegex, PHP
randexp.js, Javascript
EGRET, Python/C++
MutRex, Java
Fare, C#
rstr, Python
randexp, Ruby
goregen, Go
bfgex, Java
regexgen, Javascript
strgen, Python
random-string, Java
regexp-unfolder, Clojure
string-random, Haskell
rxrdg, C#
Regexp::Genex, Perl
StringGenerator, Python
strrand, Go
regen, Go
Rex, C#
regexp-examples, Ruby
genex.js, JavaScript
genex, Go

Solution 3:

All regular expressions can be expressed as context free grammars. And there is a nice algorithm already worked out for producing random sentences, from any CFG, of a given length. So upconvert the regex to a cfg, apply the algorithm, and wham, you're done.

Solution 4:

If you want a Javascript solution, try randexp.js.