pseudo(1)

pseudo -- STREAMS interface for non-STREAMS devices

Synopsis

pseudo [-l] [-m line]

Description

The pseudo command provides a STREAMS interface on non-STREAMS tty devices. It opens a master pseudo-tty device (/dev/ptmx) and a slave pseudo-tty device (/dev/pts/???). It pushes the pseudo-terminal emulation module ptem(7), then a line discipline module, ldterm(7) by default, onto the slave to connect the master and the slave. (The stream may be subsequently manipulated with other commands to provide the desired configuration.) pseudo then forks to become two processes. One reads from the user's tty line and writes to the pseudo-tty; the other reads from the pseudo-tty and writes to the user's tty. On the pseudo-tty side, a shell is executed.

pseudo accepts the following options:

-l: Execute a ``login shell'' (executed as -sh). By default, pseudo executes a simple interactive shell (sh -i).
-m line: Push line discipline module line instead of the default ldterm module. At most one line discipline is pushed.

The effect of running pseudo is that the user obtains an interactive shell with the standard I/O files connected to a STREAMS device that behaves as a real tty. This is useful in situations where a STREAMS device is desired but a non-STREAMS device driver is being used.

When the executed shell exits, pseudo exits and control returns to the original tty with the original termio(7) parameters.

Files

/dev/ptmx: pseudo-terminal master device
/dev/pts/*: pseudo-terminal slave devices

References

ldterm(7), ptem(7), pty(7)