Comment by zmmmmm

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?