function changes the mode and owner of the slave pseudo-terminal device
(pty) corresponding to the master pty referred to by
The user ID of the slave is set to the real UID of the calling process.
The group ID is set to an unspecified value (e.g., tty).
The mode of the slave is set to 0620 (crw--w----).
The behavior of
is unspecified if a signal handler is installed to catch
Otherwise, it returns -1 and sets
The corresponding slave pty could not be accessed.
argument is not a valid open file descriptor.
argument is valid but not associated with a master pty.
is provided in glibc since version 2.1.
This is part of the Unix98 pty support, see
Many systems implement this function via a set-user-ID helper binary
With Linux devpts no such helper binary is required.