Java™ Application Development on Linux - Dator

5.11 Bundling a Java Program: Put It in a JAR163$ jar cmf manifest payback.jar net$ ls -latotal 20drwxrwxr-x 3 mschwarz mschwarz 4096 Aug 4 18:19 .drwxrwxr-x 7 mschwarz mschwarz 4096 Aug 4 17:57 ..-rw-rw-r-- 1 mschwarz mschwarz 43 Aug 4 18:17 manifestdrwxrwxr-x 3 mschwarz mschwarz 4096 Jul 28 16:16 net-rw-rw-r-- 1 mschwarz mschwarz 7506 Aug 4 18:21 payback.jarThe options to jar tell it what to do. In our case, -c instructs to create aJAR file, -m adds the contents of the file named in the next parameter to theMETA-INF/MANIFEST file, -f and the next parameter is the filename of the JARfile being created. If we had not specified -f, the JAR file would have beenwritten to standard out and an I/O redirect would be needed, but the resultwould have been the same:$ jar cvm manifest net > payback.jar$ ls -latotal 24drwxrwxr-x 3 mschwarz mschwarz 4096 Aug 4 18:24 .drwxrwxr-x 7 mschwarz mschwarz 4096 Aug 4 17:57 ..-rw-rw-r-- 1 mschwarz mschwarz 43 Aug 4 18:17 manifestdrwxrwxr-x 3 mschwarz mschwarz 4096 Jul 28 16:16 net-rw-rw-r-- 1 mschwarz mschwarz 7506 Aug 4 18:27 payback.jarEverything that follows parameters required by option letters is consideredto be a file or directory that is to be added to the JAR file. The option syntaxfor jar is similar to that for pkzip in the DOS/Windows world and the tarutility in the UNIX world.As elsewhere in this chapter, we are just getting you started. See Sun’sdocumentation for details.5.11.2 Basic jar OperationWe have already covered the most common case, using jar to create a “rolledup”Java application. jar has many command options besides -c and we’lldocument a few of them.-c-uCreate a JAR file.Update a JAR file—replace updated files, add missing files.