INPUT$ - QB64 Wiki

INPUT$

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The INPUT$ function is used for the program input of a certain number of bytes from a user's keyboard input, a file or a port.


Syntax:

INPUT$(bytes%[, file_or_port_number])


  • Keyboard input is limited to the INTEGER number of bytes(characters) designated by program.
  • The keyboard is the default device when a file or port number is omitted. The byte number 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.
  • INPUT$ will display a cursor in a fixed spot if LOCATE , , 1 is used in the cursor parameter previous to a read.
  • Bytes cannot exceed 32767 in BINARY opened files or a Qbasic error will result.
  • RANDOM opened file bytes can be up to the LEN = record length statement or 128 if no statement is used.
  • File or port number is the number that was used in the OPEN AS statement.
  • Returns STRING values including spaces or non letter\number ASCII characters.
  • Backspacing is ignored and will add the CHR$(8) character to an entry!
  • Use LOCATE,,1 to view the cursor entry. Turn off the cursor using LOCATE ,,0.
  • Ctrl + Break will not stop the Qbasic program until there is a full INPUT$ key entry.
  • Use _DEST _CONSOLE before INPUT$ statements to be used in a console window.


Example 1: 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


Example 2: 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


Example 3: 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).


See also:



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