Robert Elz <[email protected]> wrote: > Date: Wed, 01 Aug 2018 10:56:28 +0100 > From: Robert Swindells <[email protected]> > Message-ID: <[email protected]> > > | Does it matter if ioctl(2) numbers overlap so long as they are in > | different groups ? > >To expand on thorpej's answer ... an "ioctl nulmber" is a 32 bit >constant which we typically build from a character (8 bits) an >integer (8 bits) and an argument size (13 bits), with 3 more bits >of no-copy, copy-in, copy-out. > >If the 32 bit result is different from all others, all is fine.
I understand how ioctl works. I asked because it looked as if there was a convention within that file that numbers be unique, even if they were in different groups. Robert Swindells
