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63 lines
2.8 KiB
Markdown
63 lines
2.8 KiB
Markdown
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The [INPUT$](INPUT$) function is used to receive data from the user's keyboard, an open file or an open port.
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## Syntax
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> result$ = [INPUT$](INPUT$)(numberOfBytes%[, fileOrPortNumber])
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* Keyboard input is limited to the [INTEGER](INTEGER) numberOfBytes% (characters) designated by program.
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* The keyboard is the default device when a file or port number is omitted. The numberOfBytes% is number of key presses to read.
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* INPUT$ will wait until the number of bytes are read from the keyboard or port. One byte per loop is recommended with ports.
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* [RANDOM](RANDOM) opened file bytes can be up to the [LEN](LEN) = recordLength statement, or 128 if no statement is used.
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* fileOrPortNumber is the number that was used in the [OPEN](OPEN) AS statement.
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* Returns [STRING](STRING) values including spaces or even extended [ASCII](ASCII) characters.
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* Backspace key results in the [CHR$](CHR$)(8) character being added to an entry.
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* Use `[LOCATE](LOCATE) , , 1` to view the cursor entry. Turn the cursor off using `LOCATE , , 0`.
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* Use [_DEST](_DEST) [_CONSOLE](_CONSOLE) before INPUT$ is used to receive input from a [$CONSOLE]($CONSOLE) window.
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## QBasic
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* numberOfBytes% could not exceed 32767 in [BINARY](BINARY) files or a QBasic error would occur.
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* Ctrl + Break would not interrupt the QBasic program until there was a full INPUT$ key entry. In **QB64** Ctrl + Break will immediately exit a running program.
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## Example(s)
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A keyboard limited length entry can be made with a fixed blinking cursor. Entry must be completed before it can be shown.
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```vb
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LOCATE 10, 10, 1 'display fixed cursor at location
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year$ = INPUT$(4) 'waits until all 4 digits are entered
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PRINT year$ 'display the text entry
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```
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Reading bytes from a text file for an 80 wide screen mode.
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```vb
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LOCATE 5, 5, 1 'locate and display cursor
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OPEN "Diary.txt" FOR INPUT AS #1 'open existing text file
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text$ = INPUT$(70, 1)
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LOCATE 5, 6, 0: PRINT text$ 'print text and turn cursor off
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```
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Getting the entire text file data as one string value.
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```vb
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OPEN "Diary.txt FOR BINARY AS #1 'open an existing file up to 32767 bytes
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IF LOF(1) <= 32767 THEN Text$ = INPUT$(LOF(1), 1)
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CLOSE #1
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```
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> *Explanation:* The IF statement gets the entire contents when the file size is less than 32768. The program can then work with the string by using [MID$](MID$) or [INSTR](INSTR). Note: A text file string will also have **CrLf** line break end characters [CHR$](CHR$)(13) + [CHR$](CHR$)(10).
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## See Also
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* [INPUT](INPUT), [LINE INPUT](LINE-INPUT) (keyboard input)
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* [INPUT (file mode)](INPUT-(file-mode)), [INPUT (file statement)](INPUT-(file-statement)), [LINE INPUT (file statement)](LINE-INPUT-(file-statement)) (file input)
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* [OPEN](OPEN), [LOC](LOC) (file)
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* [LOCATE](LOCATE) (cursor on/off)
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