[C] Function key 입력 받기

#include <stdio.h>
#include <conio.h>

typedef enum {F1=315,F2,F3} key;
//typedef struct tnode_ {
//        unsigned short a;
//}tnode;

int process_key() {
  int a;
  a = getch();
  if(a == 0) {
    a = getch() + 256;
  }
  return a;
}

int main() {
        while(1) {
                //printf("%d",process_key());
                switch(process_key()) {//! 2바이트 여야함
                        case F1 :
                                printf("\nf1을 눌렀다");
                                break;
                        case F2 :
                                printf("\nf2을 눌렀다");
                                break;
                        default :
                                printf("\n다른키를 눌렀다");
                                break;
                }
                                
        }
        return 0;

}