ptmx(M)                         19 June 1992                         ptmx(M)


 Name

    ptmx, pts??? - STREAMS master pseudo-tty device

 Description

    The file /dev/ptmx is the device node used by applications to open
    STREAMS-based master pseudo-tty devices. This is a single device node
    which allows access to multiple devices via the clone(M) driver. Succes-
    sive open(S) calls to /dev/ptmx return different file descriptors, each
    referring to a new cloned device.

    The master pseudo-tty device opened is used to transfer data between the
    application and one of the slave pseudo-tty nodes /dev/pts???, where ???
    is a 3 digit decimal number with leading zeros.

 Files

    /dev/ptmx
    /dev/pts???

 See also

    clone(M)

    STREAMS Programmer's Guide
    STREAMS Primer

 Notes

    Although /dev/ptmx is referred to as a pseudo-tty, the master device does
    not have tty characteristics and therefore cannot become the controlling
    tty of a process group. The slave side of the connection does have the
    characteristics of a real tty and can become the controlling tty of a
    process group.