The easiest way to list the contents of a .jar file under Linux is using: jar tvf yourjarfile.jar
This is how it looks in practice
hlars@meintempel ~/Downloads $ jar tvf maventutorial1-0.0.1-SNAPSHOT.jar
0 Tue Jan 08 16:18:50 CET 2019 META-INF/
131 Tue Jan 08 16:18:48 CET 2019 META-INF/MANIFEST.MF
0 Tue Jan 08 16:18:48 CET 2019 com/
0 Tue Jan 08 16:18:48 CET 2019 com/denofprogramming/
0 Tue Jan 08 16:18:48 CET 2019 com/denofprogramming/random/
796 Tue Jan 08 16:18:48 CET 2019 com/denofprogramming/random/DefaultRandomGenerator.class
202 Tue Jan 08 16:18:48 CET 2019 com/denofprogramming/random/RandomGenerator.class
1006 Tue Jan 08 16:18:48 CET 2019 com/denofprogramming/random/App.class
0 Tue Jan 08 16:18:50 CET 2019 META-INF/maven/
0 Tue Jan 08 16:18:50 CET 2019 META-INF/maven/com.denofprogramming/
0 Tue Jan 08 16:18:50 CET 2019 META-INF/maven/com.denofprogramming/maventutorial1/
1473 Tue Jan 08 16:17:48 CET 2019 META-INF/maven/com.denofprogramming/maventutorial1/pom.xml
128 Tue Jan 08 16:18:48 CET 2019 META-INF/maven/com.denofprogramming/maventutorial1/pom.properties