/dev/ptm
device.
It supports three
ioctl(2)s.
The first is
TIOCPTMGET
,
which allocates a free pseudo-terminal device, sets its user ID to
the calling user,
revoke(2)s
it, and returns the opened file descriptors for both the master
and the slave pseudo-terminal device to the caller in a
struct ptmget.
This struct has the following content:
struct ptmget {
int cfd;
int sfd;
char cn[16];
char sn[16];
};
where cfd and sfd contain the master resp. slave device's file descriptor and cn and sn the corresponding paths in the file system.
The
/dev/ptmx
device supports two more
ioctl(2)s,
TIOCGRANTPT
,
which is used by
grantpt(3),
TIOCPTSNAME
,
which is used by
ptsname(3).
The ptm device is included with the pseudo-device pty(4). It can be disabled by adding ``options NO_DEV_PTM'' to the kernel configuration.
/dev/ptm
/dev/ptmx
/dev/ptm
device appeared in
OpenBSD3.5
and was ported to
NetBSD3.0.