The man page for "jar" contains:
Create jar file
jar c[v0Mmfe] [manifest] [jarfile] [entrypoint] [-C dir] inputfiles [-Joption]
Update jar file
jar u[v0Mfe] [manifest] [jarfile] [entrypoint] [-C dir] inputfiles [-Joption]
The command line for "update" is inexplicably missing the "m" flag, even though
the "manifest" argument is there. Probably we need to simply change
v0Mfe to v0Mmfe as in "create".
Create jar file
jar c[v0Mmfe] [manifest] [jarfile] [entrypoint] [-C dir] inputfiles [-Joption]
Update jar file
jar u[v0Mfe] [manifest] [jarfile] [entrypoint] [-C dir] inputfiles [-Joption]
The command line for "update" is inexplicably missing the "m" flag, even though
the "manifest" argument is there. Probably we need to simply change
v0Mfe to v0Mmfe as in "create".