Is it possible to generate an example string based on a regex pattern?

Question

In my application the user can enter his own regex pattern into a text box so he can force a certain input for another user/text box. Is it possible for the user to see an examp

Answer 1

I once needed such thing too, so I created a simple program with gui using xeger lib mentioned above. Simply run .jar from dist folder (jre is required) https://github.com/ogyct/SampleFromRegex

Answer 2

For C# you may also want to look at project Fare. For more details have a look at this answer.

Example

var regex = @"((mailto\:|(news|(ht|f)tp(s?))\://){1}\S+)";
var xeger = new Xeger(regex);

var result = Regex.IsMatch(xeger.Generate(), regex);
// -> Prints 'true'

Answer 3

Check out Xeger. It looks like it can do what you want. It's in Java though.

Here is an example from the test suite:

   @Test
    public void shouldGenerateTextCorrectly() {
        String regex = "[ab]{4,6}c";
        Xeger generator = new Xeger(regex);
        for (int i = 0; i < 100; i++) {
            String text = generator.generate();
            assertTrue(text.matches(regex));
        }
    }

Update: thanks to Nikos Baxevanis, the dk.brics.automaton have been ported to C# at https://github.com/moodmosaic/Fare