Why do the md5 hashes of two tarballs of the same file differ?

Question

I can run:

echo \"asdf\" > testfile
tar czf a.tar.gz testfile
tar czf b.tar.gz testfile
md5sum *.tar.gz

and it turns out that a.ta

Answer 1

For MacOS:

In man tar we can look at --options section and there we will find !timestamp option, which will exclude timestamp from our gzip archive. Usage:

tar --options '!timestamp' -cvzf archive.tgz filename

It will produce same md5 sum for same files with same names