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Daniel Briceño
Asked: 2022-03-27 14:18:49 +0800 CST 2022-03-27 14:18:49 +0800 CST

How to know what key the user pressed without stopping the console?

  • 772

I want to make a game in MS-DOS and I'm stuck with a problem:

How to ask the user for input without stopping the console?

I've considered stopping it for a few milliseconds and giving the illusion that the console didn't stop:

@echo off
:inicio
choice /c awds0 /t 0.30 /d 0
if %errorlevel%==1 echo izquierda.
goto inicio
pause
exit

But it gives me an error:

Only a number from -1 to 999 is allowed

I have also tried to place:
choice /c awds0 /t 0 /d 0
But the key is not detected even if I put it in a buclegoto:

@echo off
:inicio
choice /c awds0 /t 0 /d 0
if not %errorlevel%==5 goto end
goto inicio
:end
echo se terminó el programa
pause
exit

input: a....

output: Infinity loop


The other option I think is to capture the click event of the window, but I don't know how and I can't find how to do it.
Note: I use windows 7 32bits. The console that I use is the one that comes by default with the operating system.

External links:

cmd

3 Answers

  1. Best Answer

    Surprise in 2021 a game in command language . You give few clues about the version of (or ) and whether it is 32 or 64 bit .

    So that the command CHOICEcan capture something from the keyboard, and not immediately return the default value, it waits an integer number of seconds: between 1 and 999. If something is typed before the time expires, it captures it and evaluates it as you already know. The minimum is one second (with 0 it would immediately return a default value and not anything we type).

    But since you indicate that YES you can add your own command. This C++ code, once compiled, does what you need:

    #include <conio.h>

int main() {
   if (_kbhit() == 0)
      return 0;
   else
      return _getch();
}

    I compile it for my tests with the name PatxiRBGetKey.exe

    The program when it is executed does NOT stop. If nothing has been typed, it returns a 0. If something has been typed, it consumes a character and returns the ASCII code that corresponds to it (nothing will be displayed on the screen).

    You can see the return value with

    echo %errorlevel%

    For example, if uppercase F was typed errorlevel would have a 70 and if lowercase f had been typed errorlevel would have a 102 and if nothing had been typed errorlevel would have a 0

    Putting it all together and slightly modifying the #Sal BAT

    @echo off
cls
:inicio
PatxiRBGetKey.exe

if %errorlevel%==87 echo W arriba
if %errorlevel%==119 echo W arriba

if %errorlevel%==65 echo A izquierda
if %errorlevel%==97 echo a izquierda

if %errorlevel%==83 echo S derecha
if %errorlevel%==115 echo s derecha

if %errorlevel%==90 echo Z abajo
if %errorlevel%==122 echo z abajo

goto inicio

    test program execution

    Cheer up and good luck.

    • 2

  2. Regarding How to ask the user for input without stopping the console?, I see that you use choice but you get the error

    Only a number from -1 to 999 is allowed

    I suggest you use:

    timeout /t <numero de segundos a esperar>

    For example, this is how you would wait for a key to continue the program:

    @echo off
:inicio
timeout /t 10 & :: Espera 10 segundos
if %errorlevel%==1 echo izquierda.
goto inicio
pause
exit

    enter image description here

    Now with regard to knowing which key the user pressed.

    editing...

    • 2

  3. In input handling is extremely limited, the furthest you'd get would be something like this:

    @echo off
:inicio
cls
if %errorlevel%==0 echo ---
if %errorlevel%==5 echo ---
if %errorlevel%==1 echo izq
if %errorlevel%==2 echo arr
if %errorlevel%==3 echo aba
if %errorlevel%==4 echo der
choice /T 1 /C awsdl /D l
goto inicio
    • 1