I need the Ubuntu codename for generating an apt source.
On Ubuntu, I can use lsb_release --codename --short, which will return (e.g.) trusty.
On (e.g.) Linux Mint, if I use lsb_release -cs, it returns (e.g.) rosa. If I want the upstream codename, I can use lsb_release -csu (which returns trusty).
However, if I use lsb_release -csu on Ubuntu, I get an error lsb_release: error: no such option: -u.
Is there a way to get the upstream-iest Ubuntu codename, including on Ubuntu?
-uin http://manpages.ubuntu.com, http://refspecs.linuxbase.org/LSB_3.0.0/LSB-PDA/LSB-PDA/lsbrelease.html, and https://linux.die.net/man/1/lsb_release. So it seems to me that-uis a modification of the lsb_release code by Mint developers. Maybe Mint's man pages can shed some light on this option. – DK Bose Jun 16 '17 at 12:58