Is AF_UNIX really deprecated?

[Erik Trulsson]

Quoting Kevin Lo <kevlo at FreeBSD.org>:

> Hi,
>
> IEEE Std 1003.1g-2000 and later POSIX standards [1] do not include
> AF_LOCAL and mention only AF_UNIX, but according to socket(2) man page it
> mentions AF_UNIX is deprecated, use AF_LOCAL instead.
>
> I'd like to add support -f local to netstat(1), I'm wondering if AF_UNIX
> is really deprecated.
>
> [1]  
> http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_socket.h.html
>
> Thanks,
> Kevin

 From what I can see the socket(2) manpage does not say anything at  
all about AF_UNIX - it talks about PF_UNIX and PF_LOCAL - which happen  
to have the same values as the corresponding AF_ defines.
(It is also worth mentioning that AF_UNIX and AF_LOCAL have the same  
value, so on FreeBSD (and Linux for that matter) it does not matter  
which of those four you use - they all have the same numerical value.)

Historically there seems to have been quite a bit of confusion over  
which variant to use (with the _LOCAL variant probably being older  
than _UNIX) but as you note the latest POSIX standard only mentions  
AF_UNIX so I suggest you use that one.

(It is also perhaps worth mentioning that the socket(2) manpage has  
preferred PF_LOCAL over PF_UNIX for more than a decade now.  I suspect  
neither is going away any time soon.)