Random Text generator based on regex [duplicate]

Answer 1

I'm not aware of any, although it should be possible. The usual approach is to write a grammar instead of a regular expression, and then create functions for each non-terminal that randomly decide which production to expand. If you could post a description of the kinds of strings that you want to generate, and what language you are using, we may be able to get you started.

Answer 2

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);

Answer 3

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

Answer 4

Too late but it could help newcomer , here is a useful java library that provide many features for using regex to generate String (random generation ,generate String based on it's index, generate all String..) check it out here .

Example :

    Generex generex = new Generex("[0-3]([a-c]|[e-g]{1,2})");

    // generate the second String in lexicographical order that match the given Regex.
    String secondString = generex.getMatchedString(2);
    System.out.println(secondString);// it print '0b'

    // Generate all String that matches the given Regex.
    List<String> matchedStrs = generex.getAllMatchedStrings();

    // Using Generex iterator
    Iterator iterator = generex.iterator();
    while (iterator.hasNext()) {
        System.out.print(iterator.next() + " ");
    }
    // it print 0a 0b 0c 0e 0ee 0e 0e 0f 0fe 0f 0f 0g 0ge 0g 0g 1a 1b 1c 1e
    // 1ee 1e 1e 1f 1fe 1f 1f 1g 1ge 1g 1g 2a 2b 2c 2e 2ee 2e 2e 2f 2fe 2f 2f 2g
    // 2ge 2g 2g 3a 3b 3c 3e 3ee 3e 3e 3f 3fe 3f 3f 3g 3ge 3g 3g 1ee

    // Generate random String
    String randomStr = generex.random();
    System.out.println(randomStr);// a random value from the previous String list

Answer 5

Instead of starting from a regexp, you should be looking into writing a small context free grammer, this will allow you to easily generate such random text. Unfortunately, I know of no tool which will do it directly for you, so you would need to do a bit of code yourself to actually generate the text. If you have not worked with grammers before, I suggest you read a bit about bnf format and "compiler compilers" before proceeding...

Answer 6

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.