C/stdlib.h/Exit 2

    
//Declaration:  void _Exit(int exit_code); 
    
  
  #include <stdlib.h>
  #include <stdio.h>
  int main(void)
  {
    char choice;
    do {
      printf("Quit (Q)\n");
      choice = getchar();
    } while(!strchr("Q", toupper(choice)));
    if(choice=="Q"){
       _Exit(0);
    }
    return choice;
  }