命令模式--示例代码

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef void(*CMD)(void);
void buyCommand(){
  printf("Buy something\n");
}
void sellCommand(){
  printf("Sell something\n");
}
#define CACHE_LEN 5
CMD  cmdCache[CACHE_LEN]={};
void excuteCMD(){
  static int pos=0;
  if(cmdCache[pos]!=NULL){
   (cmdCache[pos])();
    pos++;
    if(pos==CACHE_LEN)pos=0;
  }else{
    printf("No command excuted!\n");
  }
}
void placeCMD(CMD cmd){
    static int pos=0;
    cmdCache[pos]=cmd;
    pos++;
    if(pos==CACHE_LEN)pos=0;
}
int main(){
   excuteCMD();
   placeCMD(buyCommand);
   placeCMD(sellCommand);
   excuteCMD();
   excuteCMD();
  return 0;
}

typedef struct {
    void (*execute)(void);
} Command;

void executeA() { printf("Command A\n"); }
void executeB() { printf("Command B\n"); }
Command cmdA = { .execute = executeA };
Command cmdB = { .execute = executeB };

// 使用
cmdA.execute(); // 输出 "Command A"