Slartibartfast is on the right track, but tar's default behaviour is to descend into directories, so you may get more than one copy of the same file included in the ...
tar -r is used to append files to the end of the archive, so you would have to change the order of tar commands to achieve what you want.
Files in data.tar depends on filesystem order; Files in data.tar vary with the
For a GNU tar : --sort=ORDER Specify the directory sorting order when reading directories. ORDER may be one of the following: `none' No ...
When this option is used during archive creation, it is order sensitive.
readdir() basically. When tar finds out what files are in a directory, it directly asks the kernel for a file listing via opendir() followed by readdir() ...
XP Home Edition SP3 machine), the order of options is important.
overwrite, introduced · Options Controlling the Overwriting of Existing Files · overwrite, summary · 3.4.2 tar Options
other operations happening in the same directory, and you can't control those.
To see how this policy fits into the overall order of policy enforcement, see ...