SubstAgent

A Java agent that listens for strings containing environment variables and substitutes them accordingly. It is intended for use with Spigot plugins to enable environment variable support in their configuration files.

How to use

java -javaagent:<path to SubstAgent jar> -Xbootclasspath/a:<path to SubstAgent jar> [rest of your command as normal]
For example:
java -javaagent:./SubstAgent.jar -Xbootclasspath/a:./SubstAgent.jar -jar server.jar nogui
In the above example the SubstAgent jar is called SubstAgent.jar and is in the same directory as server.jar.