wildling

Kotlin library and CLI for pattern-based string generation. Zero third-party dependencies (Kotlin/JVM standard library only; hand-rolled JSON for templates). Targets JVM 11+.

Docs: Website · Sandbox · Syntax · Source

Registry: Maven Central

Example

http://${'dev,stage,prod'}\-${'api,web'}#{0-2}.example.${'com,net,org'}/@.html

(The \- is a literal hyphen; bare - would mean “one letter or digit”. @ is one lowercase letter.)

That builds URL-shaped candidates: scheme http://, then environment × service × optional digits × TLD, then a one-letter path page. Three environments, two services, zero–two digits ('', 0–9, 00–99), three TLDs, and a–z → 51948 strings — the kind of list you generate for fuzzing links or probing staging hosts, not type out.

A few of them:

http://dev-api.example.com/a.html / http://stage-web.example.com/z.html
http://dev-api0.example.net/a.html / http://prod-web9.example.org/m.html
http://dev-api00.example.com/a.html / http://prod-web99.example.org/z.html

Named dictionaries (%{'hosts'}) work the same way when the word lists live in files.

Try it in the sandbox, or see pattern syntax for length ranges, dictionaries, and escapes.

Install

From this repository:

cd kotlin
./build.sh
./bin/wildling "Year 19##"

From a release tag:

git clone --branch v2.0.0 --depth 1 https://github.com/dotmonk/wildling.git
cd wildling
./build.sh kotlin

Registry: Maven Central — io.github.dotmonk:wildling-kotlin

dependencies {
    implementation("io.github.dotmonk:wildling-kotlin:2.0.2")
}

Produces dist/wildling.jar via ./build.sh. Requires a JRE to run (java -jar), or Docker (the launcher falls back to the Temurin image if java is not on PATH).

As a library, add dist/wildling.jar to your classpath:

import wildling.Wildling

val wildling = Wildling.create(listOf("Year 19##"))
var value = wildling.next()
while (value != false) {
    println(value)
    value = wildling.next()
}

CLI

./bin/wildling "Year 19##"
./bin/wildling --dictionary planets:../dictionaries/planets.txt "%{'planets'}"
./bin/wildling --template ./config.json

Help text and --check output follow docs/cli.md / docs/help.txt.

Build

./build.sh   # Docker (Temurin): fetch kotlinc if needed, kotlinc + jar → dist/wildling.jar

Project tests live in ../tests/ and are run with ../test.sh.