#!/bin/bash
# Set the JAR name
jar = $1

# proofs the given argument
while test -z $jar
do
    echo "There is no argument." 
    echo "You have to type the name of the jar"
    read jar
done 
echo ""
# Loop through the classes (everything ending in .class)
for class in $(jar -tf $jar | grep '.class'); do 
    # Replace /'s with .'s
    class=${class//\//.};
    echo $class;
    # javap
    javap -v -classpath $jar ${class//.class/} | grep major;
done