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INPUT$

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Samuel Gomes edited this page Nov 8, 2022 · 1 revision

The INPUT$ function is used to receive data from the user's keyboard, an open file or an open port.

Syntax

result$ = INPUT$(numberOfBytes%[, fileOrPortNumber])

  • Keyboard input is limited to the INTEGER numberOfBytes% (characters) designated by program.
  • The keyboard is the default device when a file or port number is omitted. The numberOfBytes% is number of key presses to read.
  • INPUT$ will wait until the number of bytes are read from the keyboard or port. One byte per loop is recommended with ports.
  • RANDOM opened file bytes can be up to the LEN = recordLength statement, or 128 if no statement is used.
  • fileOrPortNumber is the number that was used in the OPEN AS statement.
  • Returns STRING values including spaces or even extended ASCII characters.
  • Backspace key results in the CHR$(8) character being added to an entry.
  • Use [LOCATE](LOCATE) , , 1 to view the cursor entry. Turn the cursor off using LOCATE , , 0.
  • Use _DEST _CONSOLE before INPUT$ is used to receive input from a $CONSOLE window.

QBasic

  • numberOfBytes% could not exceed 32767 in BINARY files or a QBasic error would occur.
  • 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.

Example(s)

A keyboard limited length entry can be made with a fixed blinking cursor. Entry must be completed before it can be shown.

LOCATE 10, 10, 1         'display fixed cursor at location
year$ = INPUT$(4)        'waits until all 4 digits are entered
PRINT year$              'display the text entry

Reading bytes from a text file for an 80 wide screen mode.

LOCATE 5, 5, 1                    'locate and display cursor
OPEN "Diary.txt" FOR INPUT AS #1  'open existing text file
text$ = INPUT$(70, 1)
LOCATE 5, 6, 0: PRINT text$       'print text and turn cursor off

Getting the entire text file data as one string value.

OPEN "Diary.txt FOR BINARY AS #1  'open an existing file up to 32767 bytes
IF LOF(1) <= 32767 THEN Text$ = INPUT$(LOF(1), 1)
CLOSE #1

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$ or INSTR. Note: A text file string will also have CrLf line break end characters CHR$(13) + CHR$(10).

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