2019-01-15 16:13:42 +0100, Joerg Schilling: > Stephane CHAZELAS <[email protected]> wrote: > > > > posh is soooo non-POSIX that even normal tests return incorrect results > > > :-( > > > > "type" is not in the POSIX base (and as a result not in > > the Debian policy) > > http://pubs.opengroup.org/onlinepubs/9699919799/utilities/type.html > > First added with issue 2, which seems to be 1997. > > Note that XSI enhancements only may be omitted in case of a UNIX system for > embedded use. So this is a similar problem as the missing multi byte support > in > "dash" that only would be permitted if dash was used on embedded systems only. [...]
The XSI optional extension is only required for systems who want to use the UNIX trademark. That's the part that comes from XPG for SysV derivatives. Most BSDs don't implement many of those XSI extensions. For instance UNIX/SysV/XPG/XSI "ps -e" conflicts with BSD "ps -e", but there's a POSIX (portable) equivalent: ps -A. POSIXly, you can use "ps -A" to report about all processes. UNIXly, you can use "ps -A" or "ps -e". On BSDs, "ps -e" means something else. Note that even UNIX (POSIX+XSI) certified systems are not compliant. For instance, macOS "/bin/echo" doesn't expand \n, \b... as POSIX+XSI requires. I don't think GNU/Debian systems care about XSI, or the UNIX trademark either. AFAICT, they concern themselves with the POSIX base, and pick XSI extensions when they are useful (and don't break their own backward compatibility). -- Stephane
