Working from the command line I extract the contents of a JAR file with "jar xf jar-file" and then I want to create another JAR file being the same as the file I extracted. Since the JAR file already has a manifest I use the command "jar cmf existing-manifest jar-file input-file(s)".

The problem I'm having is that the extracted JAR file has a TIMESTAMP file. At the same time I can't use the wild card * symbol for the "input-file(s)" argument since I don't want the manifest file to be included in the JAR twice.
I could simply type in the names of what needs to be JARed as the arguments for the "input-file(s)", but I don't know what extension the TIMESTAMP file is.

What I'd like to know is:
-what is the extension of a TIMESTAMP file?
-could I prevent a manifest file from being included twice with the wild card symbol *?
-is the above practice of what I've described okay? What I mean is, would my created JAR be the same as the original with regards to it being installed and working properly?

I've done some searching, but not finding the above info. Mostly I've learned what JAR/JAD is, and so I thought that since I could extract the files, I should be able to re-package them as well.
On another note, could I simply zip them and rename the ending to be .jar?

Thanks for your patience ...