a short snake demo for a douban friend

simple_snake_demo.c

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <pthread.h>

static void direction_up(void);
static void direction_down(void);
static void direction_left(void);
static void direction_right(void);
static void direction_up(void)
{
    printf("snake going up\n");
}
static void direction_down(void)
{
    printf("snake going down\n");
}
static void direction_left(void)
{
    printf("snake going left\n");
}
static void direction_right(void)
{
    printf("sname going right\n");
}
struct snake {
    void (*snake_move)(void);

};
static struct snake sbsnake;
pthread_t control_thread;
static void *control_routine(void *attr)
{
    while (1) {
        usleep(1000);
        switch(getchar()) {
            case 'a':
                sbsnake.snake_move = direction_left;
                break;
            case 'd':
                sbsnake.snake_move = direction_right;
                break;
            case 's':
                sbsnake.snake_move = direction_down;
                break;
            case 'w':
                sbsnake.snake_move = direction_up;
                break;
        }
    }
}
int main ( int argc, char *argv[] )
{
    pthread_create(&control_thread, NULL, control_routine, NULL);
    sbsnake.snake_move = direction_right;
    while (1) {
        sleep(1);
        sbsnake.snake_move();
    }
    return EXIT_SUCCESS;
}