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Comment by mbreese | Hacker News Reader

Java JAR files are similar, but reversed. You can add anything you want to the beginning of the JAR file (or is it any ZIP file?) so long as it doesn't include the Zip file header "PK". So, I use this to prepend a bash script that ultimately calls

    java -jar $0

It makes it very easy to setup and use Java based command line programs on a server.

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this sounds incredibly useful but I couldn't get it to work. I just get

    java.util.zip.ZipException: invalid CEN header (bad signature)
        at java.base/java.util.zip.ZipFile$Source.zerror(ZipFile.java:1623)

if I try to do anything with a JAR file that has leading text. I'm creating it just using

   echo 'java -jar $0' | cat - test.jar > test.run.jar

Is there more to it?

https://github.com/puniverse/capsule/blob/master/capsule-uti...

This is what the (now defunkt) Capsule project prepends to get this same effect

Technically, you should update the offset to the central directory in the Zip footer, along with the offsets to each file header in each central directory entry. If you don’t, the zip file reader has to apply some heuristics to locate the central directory; not all readers implement these heuristics, and those that do won’t always be robust.

The “unzip” utility can be useful as a sanity check; run “unzip -t” to test the integrity of the file.

Did you add a shebang line?

I have a small bash stub that I use. It’s roughly (I also add JAVA_OPTS, etc…):

    #!/bin/bash
    java -jar $0

Then…

    cat stub.sh myproject.jar > myexec

See: https://github.com/compgen-io/ngsutilsj/blob/master/src/scri...

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