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85 lines
3.4 KiB
Plaintext
85 lines
3.4 KiB
Plaintext
#REDIRECT [[OPEN#File_Access_Modes]]
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[[BINARY]] is used in an [[OPEN]] statement to work with the file or port device manipulating its bytes directly.
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{{PageSyntax}}
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:[[OPEN]] {{Parameter|fileName$}} [[FOR]] [[BINARY]] [[AS]] {{Parameter|#fileNumber%}}
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{{PageDescription}}
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* [[OPEN]] FOR BINARY creates the file if the {{Parameter|fileName$}} does not exist.
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* {{Parameter|fileName$}} is the name of the file to open, but could also configure a port.
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* {{Parameter|#fileNumber%}} is the number that will represent the file when performing file operations.
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* BINARY files use [[GET|GET #]] and [[PUT|PUT #]] to read or write the file at any byte position.
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* In '''version 1.000 and up''' you can use [[LINE INPUT]] in [[BINARY]] mode for faster access to text file data.
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* QBasic's [[BSAVE]] or BINARY save files can be read using BINARY mode.
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* BINARY mode ignores any [[LEN]] = recordlength statement in the [[OPEN]] statement.
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* Ports can also be opened in [[BINARY]] mode. See: [[OPEN COM]]
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{{PageExamples}}
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''Example 1:'' Shows how a PUT variable value is converted to an [[ASCII]] string [[_MK$]] format in a BINARY file.
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{{CodeStart}} '' ''
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{{Cl|DIM}} int64 {{Cl|AS}} {{Cl|_INTEGER64}}
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{{Cl|DIM}} byte8 {{Cl|AS}} {{Cl|STRING}} * 8
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int64 = 12345678
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{{Cl|PRINT}} int64
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{{Cl|OPEN}} "temp64.tmp" {{Cl|FOR...NEXT|FOR}} {{Cl|BINARY}} {{Cl|AS}} #1
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{{Cl|PUT}} #1, , int64 'the file size will be 8 bytes
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{{Cl|CLOSE}}
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{{Cl|PRINT}} "Press a key to read the file!"
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K$ = {{Cl|INPUT$}}(1)
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{{Cl|OPEN}} "temp64.tmp" {{Cl|FOR...NEXT|FOR}} {{Cl|BINARY}} {{Cl|AS}} #1
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{{Cl|GET}} #1, , byte8 'GET the value as a string
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{{Cl|PRINT}} "text string: "; byte8 'show that string is in {{Cl|_MK$}} format
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{{Cl|PRINT}} {{Cl|_CV}}({{Cl|_INTEGER64}}, byte8) 'convert to numerical value
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{{Cl|CLOSE}} '' ''
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{{CodeEnd}}
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: ''Note:'' The numerical value does not need to be converted if the file is read using the same numerical variable type as written.
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''Example 2:'' A binary file viewer that can view integer values. The type of value can be changed at [[DIM]].
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{{CodeStart}} '' ''
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{{Cl|SCREEN}} {{Cl|_NEWIMAGE}}(1000, 600, 256)
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{{Cl|_SCREENMOVE}} {{Cl|_SCREENMOVE|_MIDDLE}}
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{{Cl|DIM}} value AS {{Cl|INTEGER}} 'value type can be changed
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{{Cl|LINE INPUT}} ; "Enter a {{Cl|BINARY}} filename to open: ", file$
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{{Cl|PRINT}} " Press S to restart!"
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{{Cl|IF...THEN|IF}} {{Cl|LEN}}(file$) {{Cl|THEN}} {{Cl|OPEN}} file$ {{Cl|FOR...NEXT|FOR}} {{Cl|BINARY}} {{Cl|AS}} #1 {{Cl|ELSE}} {{Cl|END}}
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{{Cl|IF...THEN|IF}} {{Cl|LOF}}(1) = 0 {{Cl|THEN}} {{Cl|PRINT}} "Empty file!": {{Cl|END}}
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DO
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{{Cl|FOR...NEXT|FOR}} i = 1 {{Cl|TO}} 16
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x = x + 1
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{{Cl|GET}} #1, , value
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{{Cl|IF...THEN|IF}} {{Cl|EOF}}(1) {{Cl|THEN}} {{Cl|EXIT DO}}
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{{Cl|PRINT}} value;
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{{Cl|NEXT}}
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{{Cl|PRINT}} {{Cl|CHR$}}(27); x; "@"; row
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K$ = {{Cl|INPUT$}}(1)
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{{Cl|IF...THEN|IF}} {{Cl|UCASE$}}(K$) = "S" {{Cl|THEN}} {{Cl|CLS}}: x = 0: row = 0: {{Cl|PRINT}} "Restarted!": {{Cl|SEEK}} 1, 1
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{{Cl|IF...THEN|IF}} x = 256 {{Cl|THEN}} x = 0: row = row + 1: {{Cl|PRINT}}
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{{Cl|LOOP}} {{Cl|UNTIL}} K$ = {{Cl|CHR$}}(27)
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{{Cl|CLOSE}} #1
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{{Cl|PRINT}} "Press Escape to exit!"
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DO: {{Cl|_LIMIT}} 100
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{{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} = {{Cl|CHR$}}(27)
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{{Cl|SYSTEM}} '' ''
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{{CodeEnd}}
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{{PageSeeAlso}}
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* [[OPEN]], [[CLOSE]]
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* [[GET]], [[PUT]], [[LINE INPUT]]
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* [[SEEK]] (function), [[SEEK (statement)]]
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* [[INPUT (file mode)]], [[RANDOM]], [[APPEND]], [[OUTPUT]]
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* [[Bitmaps]], [[Binary]] (numbers)
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{{PageNavigation}}
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