Pseudo tty pair

Allen, Jack Jack.Allen at
Wed Oct 10 00:00:56 UTC 2007

        I have an old application that is being moved from UNIX to Linux
and it can only open what it thinks is a physical tty device. On the
UNIX system we have a process called ptsd (Pseudo Terminal Server
Daemon). It opens some configured number or Pseudo tty pairs (/dev/ptyp0
+ /dev/ttyp0) and waits for the Application to connection to one of the
slave pseudo ttys (i.e. /dev/ttyp0). Then the ptsd process forks and
runs a copy of itself, that will interact with the user as if they were
connected to a terminal server. It will allow them to make a telnet
connect (I know all about telnet not being secure and everybody should
be using ssh) to some where. It handles the telnet protocol and the
Application just thinks it is reading and writing to a physical tty

        We are running RedHat AS 4.4 and later will be running AS 5.X.
>From what I can tell both have the /dev/ptmx device and the /dev/pts
directory. By opening the /dev/ptmx file with certain options it will
create the next unused number in the /dev/pts directory. The problem is
the Application has to know the name of the pseudo so it can open it. So
I need the old style /dev/ttyp0 + /dev/ptyp0 so they can be configured
and known ahead of time.

        Is there a loadable module that will give this functionality? 

        Do I have to configure the kernel and rebuild the kernel to get
this functionality? 

Jack Allen 

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