When given the name of an existing zip archive, zip will replace identically named entries in thezip archive or add entries for new names. For example, if fooz.zip exists and contains foo/file1and foo/file2, and the directory foo contains the files foo/file1 and foo/file3, then:
- zip -r fooz foo
- http://linux.about.com/od/commands/l/blcmdl1_zip.htm