Loop until a key is pressed

This is a discussion on Loop until a key is pressed within the C++ Programming forums, part of the General Programming Boards category; I am using visual studio 2008. I am trying to write a loop that continues until a user presses the ...

  1. #1
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    Loop until a key is pressed

    I am using visual studio 2008. I am trying to write a loop that continues until a user presses the y or the n key. I can do it if the user types one or the other of these and presses enter, but I want the loop to exit once Y or N is pressed directly. What I am doing is a yes/no prompt like this.

    Code:
    char keyin;
    do
    {
            // Listen for keyboard input.  If Y or N is pressed, terminate loop.
    }
    while (keyin != toupper('y') && keyin != toupper('n');
    Thanks

  2. #2
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    Do you absolutely have to loop "listening" for a key - would calling getchar() and block your CPU usage until the key actually comes in not be a good plan?

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  3. #3
    C++まいる!Cをこわせ! Elysia's Avatar
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    I believe the OP wants a function that blocks until a key is pressed and then returns directly (without having to press enter), similar to the non-standard getch.
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    Quote Originally Posted by Elysia View Post
    I believe the OP wants a function that blocks until a key is pressed and then returns directly (without having to press enter), similar to the non-standard getch.
    In which case there are functions described in the FAQ on "how to read user input without enter" or something along those lines.

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

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