控制台窗口的显示菜单

#include <stdio.h>

char get_choice(void);
char get_first(void);
int get_int(void);
void count(void);

int main(void){
    int choice;
    void count(void);

    while ( (choice = get_choice()) != 'q')
    {
        switch (choice)
        {
            case 'a' :  printf(a.\n);
                break;
            case 'b' :  putchar('b');  /* ANSI */
                break;
            case 'c' :  count();
                break;
            default  :  printf(error!\n);
                break;
        }
    }
    printf(Bye.\n);

    return 0;
}

void count(void)
{
    int n,i;
    printf(Enter an integer:\n);
    n = get_int();
    for (i = 1; i <= n; i++)
        printf(%d\n, i);
    while ( getchar() != '\n')
        continue;
}

char get_choice(void)
{
    int ch;

    printf(Enter the letter:\n);
    printf(a. append  b. output\n);
    printf(c. count   q. quit\n);
    ch = get_first();
    while (  (ch < 'a' || ch > 'c') && ch != 'q')
    {
        printf(Please respond with a, b, c, or q.\n);
        ch = get_first();
    }

    return ch;
}

char get_first(void)
{
    int ch;

    ch = getchar();
    while (getchar() != '\n')
        continue;

    return ch;
}

int get_int(void)
{
    int input;
    char ch;

    while (scanf(%d, &input) != 1)
    {
        while ((ch = getchar()) != '\n')
          putchar(ch);  // dispose of bad input
        printf( is not an integer.\n);
    }

    return input;
}