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How to stop C++ console application from exiting immediately?
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Closed 5 years ago.
I just started using Visual Studio to write C++ code on Windows 10 and I am using the console application template. My problem is that the console disappears immediately after showing the output of my program even when I simply run a "hello world" example. I tried all kinds of tricks to implement delay but no success.
I usually put a std::cin line just before main returns. This will cause it to wait for input before continuing.
You can do the following( assuming that you are not waiting for user input, in that case you can just follow Rich's answer ) :
Run it in debugging with a breakpoint on the last line before the main returns.
Use a system("pause") at the end before the main returns.( suggesting this just because it's just a hello world program in Visual Studio )
A great way to pause the console in Visual Studios for your purposes is to use system("pause"); Though its not portable to other OS and some anti-virus systems don't like it. For your purposes it should work well and is easy to see what the line does.
Hope this helps.
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Closed 10 years ago.
Possible Duplicate:
How to stop C++ console application from exiting immediately?
Forgive me for my rather extreme newbie-ness in the field of C++ but here goes. :)
When I run say for example this code in a terminal:
int g;
cout << "Please enter an integer value: ";
cin >> g;
cout << "The value you entered is " << g;
...to you C++ experts out there, obviously this accepts a value from the user's input and then displays in the output. However, right after I "submit" my input and click enter, I see the output for a mere millisecond and then the terminal closes. Anyway I could stop the terminal from closing so I could actually have a chance to see the result?
I'm using Visual Studio on Windows 7.
Thanks!
If you're working on Windows, you can add the line system("pause"); at the end of the program.
Or cin.get() if on Linux
Depends on what you're using. For Windows it is common to use a breakpoint (__debugbreak) but for Unix people usually just run it in an existing terminal which does not close.
I don't know what kind of OS do you use, but the function is similary
start a terminal in Linux oder a Commandline in Windows.
Switch with the command "cd" to the directory where the Program lies.
Linux:
./myProgram
Windows
myProgram
The Terminal which you started wouldn't be closed ;)
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
How to stop C++ console application from exiting immediately?
I'm working with c++ and when I run my console program, it instantly exits. I can't read input from in my main method/set breakpoints because the main method is defined in another library.
So, I'm asking how can I prevent the console application from exiting by using a setting in visual studio?
Try running with Ctrl+F5. This will stop the console at the end of the execution.
If I understood correctly you can't read the output of your program because console closes immediately. To prevent this you can call system("pause"); just before returning from main.
int main()
{
// processing...
system("pause");
return 0;
}
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
How to stop C++ console application from exiting immediately?
I'm currently learning C++ and cant figure out how to stop the application from exiting when I want to show the user some data, and have time to read it. How may i do that?
Update: Somehow I pause the application and when the user click a button it exits.
I assume you're on Windows.
This can turn into a long debate, but generally there are two main ways people do it:
(recommended) Add cin.get(); to the end of your program. This will cause your program to stop until the user hits enter, then it will continue and quit.
This will work on Windows and Linux.
Add system("PAUSE"); at the end of your program. This will cause your program to print something like Press any key to continue. . . and when you hit a key, the program will continue and quit.
There is a chance that the PAUSE command doesn't do that and can order pizza, launch the missiles, or something else.
This only works for Windows but you won't need it when you go to linux anyway.
std::cout << "Press enter to exit" << std::endl;
cin.get();
exit(1);
If you want to pause your program until the user presses a key, you can use cin.get(). But really, the program should terminate when it's finished. Otherwise, it's useless in pipelines and the like.
If your program's window goes away when it's finished, then something is wrong with the way you launched it. Whether the window stays when the program is done is up to the thing that launches the program and sets up the window, not the program. This problem is usually caused by launching CLI programs from a GUI. If you want to launch from a GUI, write a GUI program. Otherwise, launch terminal programs from the terminal.
Do not use system("pause");. It makes your program unportable. And if you ever run it on a system whose pause command does something other than what you want, you may have a very angry user on your hands.
Do not use getch. That's a Windows console function and a Curses function. It's not part of C++. (Unless you are specifically developing for a platform that has this function and you are sure it does what you want. But this one function would be a really silly reason to make your program unportable.)
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
How to keep the console window open in visual c++?
I have a program that runs on my home machine, but on another machine it quits instantly when being executed. The console window opens and closes so fast that I can't read the output. How can I make sure this output stays visible, so I can read what it's trying to tell me?
Since it's a console application run it from a cmd window.
You can set Visual Studio to break when an exception is thrown (of course this will only work if an uncaught exception is what is causing your program to terminate early).
Im currently learning c++ from a book called 'Ivor Hortons Beginning Visual c++ 2010'.
In all the examples i've attempted so far I've had to use getch() to hold open the command prompt, and sometimes remove the return 0 statement from the end of the main method.
Is this a vagary of windows 7 and will it cause problems further down the line? It's no problem doing this at the moment but since this is not included in the book I was wondering if it might be something I've set up wrong.
Many Thanks :)
Use _getch() in place of getch()
getch() is not operating system specific, but it is not directly portable. The preferred method for doing this in C++ is to use std::cin.get();.
The main function can return 0 implicitly (you don't need to actually have that code, see below).
int main()
{
// valid, return 0 implied.
}
See this question for more details about the implicit return 0 from main.
When a program ends, any resources created by that program including the terminal window will be released. By using getch you prevent the program from ending. This is normal behavior and should continue to work that way until Windows is a distant memory.
If you start the program from within an already existing command window, the window will not close because it wasn't created by the program.
First, getch() isn't a standard C or C++ function. Even under
Windows, I think its use is deprecated; its semantics go back to CP/M
and early MS-DOS.
Secondly, it really isn't necessary, at least not for console apps (and
I don't think it's available for non-console apps). If you're running
the program from a console window, the window stays open. And if you're
running it from Visual Studios, it's trivial to set a breakpoint on the
return statement, which blocks the program, and keeps the window open
(although there's really no reason for the IDE to close it just because
your program has terminated).