javadyn - invoke different Java based on command line argument

javadyn.rb

#!/usr/bin/env ruby
JAVA8BIN = "/usr/lib/jvm/zulu-8-amd64/bin/java"
JAVA12BIN = "/usr/lib/jvm/zulu-12-amd64/bin/java"
#puts ARGV
if ARGV.include?("--javaver") then
        i1 = ARGV.index("--javaver")
        i2 = i1+1
        if ARGV[i2] == "8" then
#               puts "Using Java 8"
                arr = ARGV.select { |e| ARGV.index(e) != i1 && ARGV.index(e) != i2 }
#               puts "Invoking Java with "
#               puts arr
                Kernel.exec([JAVA8BIN, JAVA8BIN], *arr)
                Kernel.exit(0)
        end
end
#puts "Using Java 12"
Kernel.exec([JAVA12BIN, JAVA12BIN], *ARGV)