Operations
----------
`--append'
`-r'
Appends files to the end of the archive. Note:append.
`--catenate'
`-A'
Same as `--concatenate'. Note:concatenate.
`--compare'
`-d'
Compares archive members with their counterparts in the file
system, and reports differences in file size, mode, owner,
modification date and contents. Note:compare.
`--concatenate'
`-A'
Appends other `tar' archives to the end of the archive. Note:concatenate.
`--create'
`-c'
Creates a new `tar' archive. Note:create.
`--delete'
Deletes members from the archive. Don't try this on a archive on a
tape! Note:delete.
`--diff'
`-d'
Same `--compare'. Note:compare.
`--extract'
`-x'
Extracts members from the archive into the file system. Note:extract.
`--get'
`-x'
Same as `--extract'. Note:extract.
`--list'
`-t'
Lists the members in an archive. Note:list.
`--update'
`-u'
Adds files to the end of the archive, but only if they are newer
than their counterparts already in the archive, or if they do not
already exist in the archive. Note:update.