OPEN                     Allow File or Device I/O

 (1) OPEN filespec [FOR mode] [ACCESS access] [lock] AS [#]filenum [LEN=recl]

 or

 (2) OPEN mode2, [#]filenum, filespec [,recl]

    Makes a file or device available for sequential input, sequential
    output, or random access (either input or output).

     filespec  A string expression that follows DOS file naming conventions.

     filenum    An integer expression in the range 1 to 255.

        mode    (Syntax 1) One of the following (default is RANDOM):

                INPUT    Sequential input
                OUTPUT   Sequential output
                APPEND   Sequential output, beginning at current EOF
                RANDOM   Random input/output

      access    If included, must be one of the following:

                READ          File is opened for reading only.
                WRITE         File is opened for writing only.
                READ WRITE    File is opened for both reading and writing.

        lock    If included, must be one of the following:

                SHARED   Any process may read from or write to the file.
                LOCK READ     No other process is granted read access to
                    the file.
                LOCK WRITE    No other process is granted write access to
                    the file.
                LOCK READ WRITE    No other process is granted either read
                    or write access to the file.

        recl    An integer expression in the range 1 to 32767. Sets the
                record length for random files and the capacity of the I/O
                buffer for sequential files. Defaults to 128.

       mode2    (Syntax 2) A string expression that must evaluate to one
                of the following:

                I   Sequential input
                O   Sequential output
                A   Sequential output at EOF
                R   Random input/output

   ----------------------------------------------------------------------

      Notes:    If a file is opened in RANDOM mode with no ACCESS code
                specified, QuickBASIC tries to open it for read/write
                access. If permission is denied, it then tries write-only
                access, then read-only access.

                The read/write access code can be specified only for files
                opened for APPEND in RANDOM mode.

                The OPEN statement has additional optional arguments when
                the device being opened is COM1: or COM2:. See OPEN COM...

                Opening an existing file for sequential output destroys
                the current file contents; to add to the current file,
                open it for APPEND (the APPEND mode may be used only for
                sequential disk files).

                A file that is already open may not be opened for
                sequential output or append.

                Opening a nonexistent file for APPEND is equivalent to
                opening it for OUTPUT.

                Disk files and printers may be opened for either
                sequential or random access. All other standard devices
                may be opened only for sequential access.