lib/commonio.c: Rely on the POSIX.1-2008 behavior of realpath(3)

[alejandro-colomar]

Link: #1222 (comment)
Link: https://stackoverflow.com/questions/60802732/are-realpath-portability-concerns-obsolete
Reported-by: @sthibaul

[ikerexxe]

I only have a question here. Is it POSIX.1-2008 or POSIX.1-2018? I would say it is the second but I prefer to have it confirmed.

[alejandro-colomar]

I only have a question here. Is it POSIX.1-2008 or POSIX.1-2018? I would say it is the second but I prefer to have it confirmed.

$ man standards 2>/dev/null | grep '^       POSIX.1'
       POSIX.1‐1988
       POSIX.1‐1990
       POSIX.1b (formerly known as POSIX.4)
       POSIX.1c (formerly known as POSIX.4a)
       POSIX.1d
       POSIX.1g
       POSIX.1j
       POSIX.1‐1996
       POSIX.1‐2001
       POSIX.1‐2008
       POSIX.1‐2017

You're probably asking about POSIX.1-2017. POSIX.1-2008 is the major revision of the POSIX standard. In 2017, a Technical Corrigenda was issued, but which didn't meaningfully change the standard, so we keep referring to the 2008 one. It's similar to C11 and C17. C11 was a major revision of ISO C, and C17 is just the same with a Technical Corrigenda applied.

If you go to the online publication of POSIX.1-2017, it says that at the top (in other words):

The Open Group Base Specifications Issue 7, 2018 edition
IEEE Std 1003.1™-2017 (Revision of IEEE Std 1003.1-2008)

https://pubs.opengroup.org/onlinepubs/9699919799/

(BTW, it is the 2018 edition because it was finally published in 2018, but the name is 2017 because it was finalized in 2017; just like C23 is called C23 even if it was published by ISO in 2024 --because ISO is so slow at publishing what the C Committee handles to them--.)

[ikerexxe]

Thanks for the explanation, now I see why I got confused. LGTM!