There are patches required. Many GNU utilities are very close to the UNIX spec, but not quite the UNIX spec - including glibc. But making a Linux distro that is UNIX certified would likely make it a worse Linux distro for most people since it would be less compatible with what everyone is assuming for a Linux distro. A lot of the differences are subtle edge cases, but do you really want that in your distro?
It's not just about going through a song-and-dance. It's about making an OS that has different behavior - often very tiny differences, but differences that would make the distro worse for most users.
> It's not just about going through a song-and-dance. It's about making an OS that has different behavior - often very tiny differences, but differences that would make the distro worse for most users.
Is this actually true? Can you give a real example of where Huawei EulerOS or Inspur K-UX are inferior to their non-certified base (yet another Red Hat Enterprise Linux clone) due to their UNIX certification?
I'm not sure why you would. I don't think POSIX generally specifies the behavior of command line tools in such a level of detail. FWIW, the regex type used by default by GNU Grep is already POSIX's Basic Regular Expressions. (It also supports POSIX Extended Regular Expressions and PCRE2.)
Afaik, EulerOS and other Unix-certified Linux distros just ship the usual GNU userland.
The Single UNIX Specification does specify the behavior of many command line tools like ed, grep, awk, etc. OpenBSD sometimes notes where their tools vary from the UNIX spec. It's usually very small ways that don't matter to most people, but it does put them outside of the UNIX spec.
