clone(M)                        19 June 1992                        clone(M)


 Name

    clone - open any minor device on a STREAMS driver

 Description

    clone is a STREAMS software driver that finds and opens an unused minor
    device on another STREAMS driver.  The minor device passed to clone dur-
    ing the open is interpreted as the major device number of another STREAMS
    driver for which an unused minor device is to be obtained.  Each such
    open results in a separate stream to a previously unused minor device.

    The clone driver consists solely of an open function.  This open function
    performs all of the necessary work so that subsequent system calls
    (including close(S)) require no further involvement of clone.

    clone will generate an ENXIO error, without opening the device, if the
    minor device number provided does not correspond to a valid major device,
    or if the driver indicated is not a STREAMS driver.

    clone will generate an ENODEV error, without opening the device, if a
    pipe cannot be created.

 Warnings

    Multiple opens of the same minor device cannot be done through the clone
    interface.  Executing stat(S) on the file system node for a cloned device
    yields a different result from executing fstat(S) using a file descriptor
    obtained from opening the node.

 See also

    log(M), pipe(ADM), pipe(S)

    STREAMS Programmer's Guide