99 lines
3.9 KiB
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99 lines
3.9 KiB
HTML
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<HEAD><TITLE>QuickBASIC 3.0 - Long Entry</TITLE></HEAD>
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<PRE>
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<B>OPEN Allow File or Device I/O</B>
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(1) <B>OPEN</B> <U>filespec</U> [FOR <U>mode</U>] [ACCESS <U>access</U>] [lock] <B>AS</B> [#]<U>filenum</U> [LEN=<U>recl</U>]
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or
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(2) <B>OPEN</B> <U>mode2</U>, [#]<U>filenum</U>, <U>filespec</U> [,<U>recl</U>]
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Makes a file or device available for sequential input, sequential
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output, or random access (either input or output).
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<U>filespec</U> A string expression that follows DOS file naming conventions.
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<U>filenum</U> An integer expression in the range 1 to 255.
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<U>mode</U> (Syntax 1) One of the following (default is RANDOM):
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INPUT Sequential input
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OUTPUT Sequential output
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APPEND Sequential output, beginning at current EOF
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RANDOM Random input/output
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<U>access</U> If included, must be one of the following:
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READ File is opened for reading only.
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WRITE File is opened for writing only.
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READ WRITE File is opened for both reading and writing.
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<U>lock</U> If included, must be one of the following:
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SHARED Any process may read from or write to the file.
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LOCK READ No other process is granted read access to
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the file.
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LOCK WRITE No other process is granted write access to
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the file.
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LOCK READ WRITE No other process is granted either read
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or write access to the file.
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<U>recl</U> An integer expression in the range 1 to 32767. Sets the
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record length for random files and the capacity of the I/O
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buffer for sequential files. Defaults to 128.
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<U>mode2</U> (Syntax 2) A string expression that must evaluate to one
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of the following:
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I Sequential input
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O Sequential output
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A Sequential output at EOF
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R Random input/output
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----------------------------------------------------------------------
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<B>Notes:</B> If a file is opened in RANDOM mode with no ACCESS code
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specified, QuickBASIC tries to open it for read/write
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access. If permission is denied, it then tries write-only
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access, then read-only access.
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The read/write access code can be specified only for files
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opened for APPEND in RANDOM mode.
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The OPEN statement has additional optional arguments when
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the device being opened is COM1: or COM2:. See OPEN COM...
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Opening an existing file for sequential output destroys
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the current file contents; to add to the current file,
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open it for APPEND (the APPEND mode may be used only for
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sequential disk files).
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A file that is already open may not be opened for
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sequential output or append.
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Opening a nonexistent file for APPEND is equivalent to
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opening it for OUTPUT.
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Disk files and printers may be opened for either
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sequential or random access. All other standard devices
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may be opened only for sequential access.
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</PRE>
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<HR>
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<B>See Also:</B>
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<A HREF="ng21818.html">OPEN "COM...</A>
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<HR>
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This page created by ng2html v1.05, the Norton guide to HTML conversion utility.
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Written by <A HREF="http://www.acemake.com/hagbard">Dave Pearson</A>
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