682530b4a8
This is a direct port of the kernel %b format. I'm unclear on if (more) non-portable printf extensions will be a problem. I think it's desirable to have userspace formats include all kernel formats, but there may be competing goals I'm not aware of. Reviewed by: no one, unfortunately Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D8426