PTM(4)                  NetBSD Kernel Interfaces Manual                 PTM(4)

     ptm -- pseudo-terminal multiplexor device

     pseudo-device pty [count]

     The ptm driver is the backend for the /dev/ptm device.  It supports three
     ioctl(2)s.  The first is TIOCPTMGET, which allocates a free pseudo-termi-
     nal 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 dis-
     abled by adding ``options NO_DEV_PTM'' to the kernel configuration.

     /dev/ptm                          ptm access device

     /dev/ptmx                         ptm cloning device, used to implement
                                       Unix98 ptys

     grantpt(3), openpty(3), posix_openpt(3), ptsname(3), unlockpt(3), pty(4)

     The /dev/ptm device appeared in OpenBSD 3.5 and was ported to NetBSD 3.0.

NetBSD 5.0_RC4                 November 12, 2005                NetBSD 5.0_RC4

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