Allow adding entries to MANIFEST.MF

[helpermethod]

Some tools like PicoCLI provide ways to extract its version from MANIFEST.MF. It would be cool if jbang would provide a way to add additional entries to the JAR's manifest :).

[maxandersen]

We do actually write to manifest.mf various values so could consider it.

Just need to find a decent syntax for it.

Thinking about it should investigate what actually happens if you do //FILE manifest.mf

It might actually break current manifest updating.

[maxandersen]

Turns out we already have support for it.

///usr/bin/env jbang "$0" "$@" ; exit $?

//JAVAAGENT test=42 Specification-Version=4.2.x

import static java.lang.System.*;

public class test {

    public static void main(String... args) {
        out.println("Hello World");
    }
}

could argue might as well just rename //JAVAAGENT to //MANIFEST or at least support both.

[helpermethod]

Is it possible to pass in a value at build time?

[maxandersen]

We could allow usage of properties in the key yes.

Not currently implemented though.

[quintesse]

might as well just rename //JAVAAGENT to //MANIFEST

Almost, the existence of //JAVAAGENT treats the app as a java agent, which is not what you want (it has different main class handling and such). So we'd want both and treat them slightly different.

[maxandersen]

Yes true.

[maxandersen]

Available in 0.98 - thanks for the suggestion!

[quintesse]

Btw, I just remembered that if you add a //GAV line to your source file the information in there will be stored inside a pom.xml file inside the JAR. That might also be an option for you besides adding a custom MANIFEST entry.