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OPEN

1977 Version of ANSI Standard

OPEN command

See Open for formal definition.

  1. Result Right Arrow Devnam,
    Null string ("") Right Arrow B.
  2. Result Right Arrow B.
  3. Search the Openlist for the device named in Devnam.
    If found, perform only operation c. below and take no further action.
    Otherwise, perform all the following operations:
    1. Attempt to seize exclusive ownership of the device named in Devnam.
      This operation suspends execution until it succeeds.
    2. Add the specified device to the Openlist.
    3. If B contains any device parameters, find the device named in Devnam in the Devicelist, and change those parameters which appear in Result.
    4. Perform any initiation procedures for the device named in Devnam according to its device parameters in Devicelist.
  4. Set up a timer of Timeout seconds.
    Search the Openlist for the device named in A.
    If found, perform operation 3c and indicate that the timer has not expired.
    Otherwise, attempt to seize exclusive ownership of the device named in Devnam at least once, and then repeatedly until it succeeds, or the timer expires, whichever occurs first.
    If ownership is established prior to expiration of the timer, perform actions 3b, 3c, and 3d.
  5. False Right Arrow Ifswitch $TEST).
  6. True Right Arrow Ifswitch ($TEST).
Button for 1977 Button for 1984 Button for 1990 Button for 1995 Button for MDC Button for notes Button for examples

Copyright © Standard Documents; 1977-2024 MUMPS Development Committee;
Copyright © Examples: 1995-2024 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2024 Ed de Moel.

This page most recently updated on 16-Nov-2023, 10:06:52.

For comments, contact Ed de Moel (demoel@jacquardsystems.com)