Can I trust that every Debian-derived distro will have a 'base-files' package that contains '/etc/debian_version'?

Question

What I want is a quick, reliable command to ascertain that the Linux I'm running in is Debian-based. The following command seems to work. It also returns the Debian version:

dpkg -L base-files 2>/dev/null | grep '^/etc/debian_version$' >/dev/null 2>&1 && cat /etc/debian_version

My previous idea was to use dpkg -S /etc/debian_version to see if it belonged to some package, regardless of name. But dpkg -S is slow.

I only have a lingering doubt: are there older Debian-derivated distros where my assumption doesn't hold? Is there a better way?

Answer 1

A better approach is to test that what you want to do is possible rather than relying on what the distribution is. For example my Ubuntu box claims it is "squeeze/sid". If you want to install something via dpkg, check dpkg is where you expect it an is executable. If you want to modify the networking setup? Check that /etc/networking/interfaces exists. Check for tools like update-rc.d etc.

You should also use /etc/lsb-release rather than /etc/debian_version.

Answer 2

I don't believe you can make that assumption no.

Please see:

• http://serverfault.com/questions/3331/how-do-i-find-out-what-version-of-linux-is-running
• http://serverfault.com/questions/57616/how-do-i-find-out-the-distro-of-a-server
• http://serverfault.com/questions/55834/determining-type-of-linux-machine