Re: Take in a command while doing something else
Stuart Golodetz writes:
Nick W writes:
I will be using a C++ program to control a robot, and would like to
"accept" keyboard-entered commands (strings) while the program is
running and controlling the robot as a part of the control cycle. What
is the best way of doing this please?
The C++ programming language does not define any entity which is
called a "keyboard". Your question is about the specific C++
implementation you are using, rather than the C++ language itself,
and the correct answer to your question depends on your specific C++
implementation and operating system. The answer would be different,
for example, was your application running on Microsoft Windows,
Linux, or Mac.
You can do platform-independent input by just reading from std::cin
Read OP's original message and pay attention. He is asking for reading
cin only when input is available. poll() or select() is not available
Actually he didn't say that - although I agree it's probably what he'll
ultimately want. I did pay attention to what he did say, which was that
he wanted to accept commands entered at the keyboard and use them to
control the robot. As a very hacked-together example:
bool done = false;
// TODO: Do something interesting here
std::cout << "Enter a command: ";
if(cmd == "quit")
done = true;
The fact that the specification for the C++ language (note: not the
language itself) doesn't define what a "keyboard" is doesn't mean that
you can't portably get some sort of input from a keyboard (you might not
Yeah, but that was not the original question.
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