On Mon, Aug 10, 2020 at 9:21 AM Joerg Schilling <Joerg.Schilling@xxxxxxxxxxxxxxxxxxx> wrote: > Larry Dwyer via austin-group-l at The Open Group <austin-group-l@xxxxxxxxxxxxx> wrote: > > > How about the "control" side and the "terminal" side (of the paired > > device files)? > > The Solaris man pty page since a really long time has this: > > By default, 48 pseudo-terminal pairs are configured as follows: > > /dev/pty[p-r][0-9a-f] controller devices > /dev/tty[p-r][0-9a-f] slave devices > > so I would be OK with "controller" side and "terminal" side. (libc-alpha, Michael - sorry about not responding to any of this thread last week, my actual job has had me swamped. I still mean to give a whack at revising the glibc manual with this terminology but I won't be able to get to it until *next* week at the earliest.) I like "terminal side" for the tty[p-r][0-9a-f] | pts/[0-9]+ devices, but "control(ler) side" still gives the wrong impression IMNSHO. The pty[p-r][0-9a-f] | ptmx devices don't exert any actual control over anything. They are just the other side of a bidirectional communication channel. It's not like USB, where the "master" side is the only one that can initiate a data transfer. The relationship between "real" terminals and "pseudo" terminals is very much like the relationship between remote network sockets and loopback sockets. Data received from, or written to, a "real" terminal is transferred over a hardware communications channel from/to an external device, such as an RS232 serial line or a directly-attached console. With a "pseudo" terminal, on the other hand, the data is transferred over a software queue from/to another program running on the same computer (e.g. sshd, screen, xterm). So I think an inside/outside metaphor is more appropriate: how about "outside", "exterior", or "external" device for the pty[p-r][0-9a-f] | ptmx devices ? zw
