SVID msg funcs?

[Ian Lance Taylor]

Barry Clarkson <cheekyscamp@yahoo.co.uk> writes:

> We are porting come code to Linux using gcc...
> 
> gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-49)
> 
> Some of our code includes <sys/msg.h> for the
> definition of 'msgbuf' but it doesn't compile unless
> you use D_GNU_SOURCE.  
> 
> I thought that this was SVID functionality?
> Should we be using <linux/msg.h>?
> When should you use <linux/...h> as opposed to
> <sys/...h>?

This is not a gcc question, as gcc does not provide the header files
or library code.  This is a glibc or GNU/Linux question.  You need to
ask somewhere else.

My general understanding is that you should not use <linux/...h>
unless you are writing kernel code.  My general understanding is
although that msgbuf is not in SVID, although message queues are.  But
I am not an expert, and I am quite likely wrong.

Ian