How to exit console screen in C language

Question

I'm trying to exit the console screen i.e close the screen what command can i use to achieve this.

void main()
{
    int n;
    printf("Please enter a number less than 5");
    scanf("%d", &n);
    if(n <= 5)
       printf("good");
     else
     {
        printf("You entered a number above so the program will exit");
        //here i need to call a function or use a command that will close
        // the console screen;
     }
}

Any help will be appreciated thanks

Answer 1

The C11 standard n1570 does not know about the "console screen" (and I guess you speak of the terminal emulator running your program). Notice that C11 does not mention "screens" or "keyboards" (only standard streams, and very often stdout is not a "console") and many computers (e.g. most Internet servers or supercomputers, or even your mobile phone...) don't have both. Also, your program could be run (even on Windows) with redirections or in a pipeline and then it has no console (so your question don't make any sense in such a common case).

So in general, there is no way to do what you want (since it does not make any sense), in a standard way.

Perhaps your operating system provide some (OS specific) way to achieve that. So investigate the OS API relevant to your system (e.g. WinAPI on Windows, or Linux syscalls -listed in syscalls(2)).

Perhaps you want to use some terminal related library like ncurses.

If your terminal follows the ANSI escape code conventions, you might follow them.

Otherwise, consider making your program having some GUI. For that, you practically need some widget toolkit (such as Qt, GTK, etc..)

You might also consider some inter-process communication with your desktop environment. How to do that (or even its possibility) is very operating-system and desktop specific and might be related to session management.

BTW, remember that stdout is often buffered (and perhaps line-buffered). You'll better end your printf control strings with \n and/or call fflush.

Answer 2

In a windowing operating system or execution environment the console window will close immediately the process terminates, so it is not clear what you are asking here since in your example the program terminates regardless of what input is entered.

If you are running the code from an IDE, often the IDE will create a console process and launch your code within that. In that case the console is not "owned" by your application, but is executed as a child process; in which case the window will remain open until the parent process launched by the IDE is closed. Similarly if you launch your program from a command shell. It is probably unreasonable behaviour for a process to attempt to close its parent even if it is possible.

It is possible to "hide" the console window while the process continues to run, which may be what you are asking; the means of doing that is platform specific, and you have not specified; for Windows such a question would be a duplicate of Win32 programming hiding console window. However it is quite possible that these methods will not work if the process is not launched directly but from some other console process.

Answer 3

in Windows you may simply write code on Notepad, then compile and run it through the Command prompt (cmd.exe). If you have GCC installed as compiler (with all the needed packages), then compile your main.c file as:

gcc main.c -o main.exe

If all went fine, as you run "main", there will be all of your output that you can close or step over for more editing. Bye

PS EDIT -- I see your point: when you launch your .exe from itself, the window closes without giving satisfaction of the messages. You may add a workaround like this before the last curly bracket:

    printf("Press any key\n");
    scanf("%d");

}

So the output window will still wait for one more input before closing.

You may check for additional information for eg here: https://www3.ntu.edu.sg/home/ehchua/programming/cpp/gcc_make.html

Bye