VMS Help  —  Lexicals  F$UNIQUE
    Valid on Alpha and Integrity server systems only.

    Generates a string that is suitable to be a file name and is
    guaranteed to be unique across the cluster. Unique file names can
    be useful when creating temporary files. (See CLOSE/DISPOSITION
    for an example.)

    The F$UNIQUE function has no arguments, but must be followed by a
    blank pair of parentheses.

    Format

      F$UNIQUE()

1  –  Return Value

    A character string containing the unique string.

2  –  Examples

    1.$ WRITE SYS$OUTPUT F$UNIQUE()
      414853555241159711D7DF797CCF573F
      $
      $ WRITE SYS$OUTPUT F$UNIQUE()
      414853555241509811D7DF797E3F2777
      $

      This example shows how a unique string is returned on
      subsequent WRITE commands.

    2.$ OPEN/WRITE TEMP_FILE 'F$UNIQUE()
      $ DIRECTORY

      Directory WORK1:[TEST]

      594B53554C421C9C11D75463D61F58B7.DAT;1

      Total of 1 file.
      $
      $ CLOSE/DISPOSITION=DELETE TEMP_FILE
      $ DIRECTORY
      %DIRECT-W-NOFILES, no files found
      $

      The first command creates a temporary file and gives it a
      unique name, which is displayed by the subsequent DIRECTORY
      command. After the file is later closed and deleted, it no
      longer shows up in the directory.
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