On Fri, Mar 11, 2022 at 10:16:24PM +0100, Marc Haber wrote:
[^[:alpha:]]chown[[:space:]][^[:space:]]+\.[^[:space:]] is found 829 times in Debian, mostly in docs and comments, but also in a few live scripts. I think that we still have some way to go until we get rid of the dot notation in chown calls.
It also has to be a variable; if it's "root.root" or such, it doesn't matter. I did a similar search, mostly found false positives (e.g., perl or ruby scripts not actually calling chown(1). The one real example I found in a cursory glance is from /usr/bin/humfsify in uml-utilities...but it's also an example of my point about "so many ways to break shell scripts if you don't follow every semi-documented rule every time": find file_metadata -type d | xargs chown $user.$group so, yeah, that'll break if $user has a dot--but it's already broken if there's a file/directory with a space. So are dots the straw that breaks the camel's back?
And remember, there are existing real-world debian systems that have users with dots (regardless of local adduser policy; think ldap/ad for example) so these are already issues that either need to be fixed or don't really matter.