F_SETPIPE_SZ undeclared

Question

I have included following headers:

#include 
#include 
#include 
#include 

#include 

        

Answer 1

F_SETPIPE_SZ/F_GETPIPE_SZ are relatively recent. Older kernels (e.g. 2.6.32 as used in RHEL6) don't have them. If you look in /usr/include/linux/fcntl.h and these constants aren't defined, then this API isn't going to work and you'll have to find some way to bypass it in whatever you're building.

Answer 2

So here's the solution, thanks to Chrono Kitsune:

Put

#define _GNU_SOURCE

before any includes.

You should also pay attention to Chrono Kitsune's other comment.