#include <iostream>
#include <cstring>using namespace std;class mystring
{char* buf;
public:mystring(); //构造函数mystring(const char* str); //构造函数void show(); //输出函数void setmystr(const mystring str); //设置函数const char* getmystr() const; //获取函数void append(const mystring str); //追加函数int isEqual(const mystring str); // 比较函数~mystring(); //析构函数
};mystring::mystring()
{buf = (char*)calloc(1,1);
}mystring::mystring(const char * str)
{int len = strlen(str);buf = (char*)calloc(1,len+1);strcpy(buf , str);
}void mystring::show()
{cout << buf << endl;
}void mystring::setmystr(const mystring str)
{free(this->buf);int len = strlen(str.buf);this->buf = (char*)calloc(1 , len+1);strcpy(this->buf , str.buf);
}const char* mystring::getmystr() const
{return buf;
}//追加函数
void mystring::append(const mystring str)
{int len1 = strlen(this->buf);char* temp = (char*)calloc(1,len1+1);strcpy(temp , this->buf);free(this->buf);int len2 = strlen(str.buf);this->buf = (char*)calloc(1,len1+len2+1);strcat(this->buf , temp);strcat(this->buf , str.buf);
}//比较函数
int mystring::isEqual(const mystring str)
{if(strcmp(buf , str.buf) > 0){return 1;}else if(strcmp(buf , str.buf) < 0){return -1;}elsereturn 0;/*int i = 0;while(this->buf[i] != '\0' || str.buf[i] != '\0'){if(this->buf[i] < str.buf[i] || this->buf[i] == '\0'){return -1;}else if(this->buf[i] > str.buf[i] || str.buf[i] == '\0'){return 1;}i++;}return 0;*/
}//析构函数
mystring::~mystring()
{free(buf);buf = NULL;
}int main()
{mystring str = "hello world";mystring ptr;str.show();ptr.setmystr("hello kitty");cout << ptr.getmystr() << endl;ptr.append(str);ptr.show();str.show();int res = ptr.isEqual(str);if(res < 0){cout << "ptr < str" <<endl;}else if(res > 0){cout << "ptr > str" <<endl;}else{cout << "ptr = str" <<endl;}return 0;
}

#include <iostream>
#include <cstdio>
#include <cstring>using namespace std;class myfile
{FILE * fp;
public:myfile();FILE * myfopen(const char * pathname , const char * mode);size_t mywrite(const void * buf , size_t size , size_t num);size_t myread(void * buf , size_t size , size_t num);~myfile();
};myfile::myfile()
{fp = NULL;
}FILE * myfile::myfopen(const char *pathname, const char *mode)
{fp = fopen(pathname,mode);if(fp == NULL){return NULL;}return fp;
}size_t myfile::mywrite(const void *buf, size_t size, size_t num)
{size_t res = fwrite(buf , size , num , this->fp);cout << "wres = " << res << endl;if(res == 0 || res < num){return 0;}return 1;
}size_t myfile::myread(void * buf, size_t size, size_t num)
{size_t res = fread(buf , size , num , this->fp);cout << "res = " << res << endl;if(res == 0 || res < num){return 0;}return 1;
}myfile::~myfile()
{fclose(fp);
}int main()
{myfile fp;fp.myfopen("./test1.txt" , "w");while(1){char buf[64] = {0};cout << "请输入：" << endl;cin >> buf;if(strcmp(buf , "quit") == 0){break;}fp.mywrite(buf , 1 , sizeof(buf));}fp.~myfile();fp.myfopen("./test1.txt" , "r");while(1){cout << "111" << endl;char rbuf[64] = {0};size_t res = fp.myread(rbuf , 1 ,sizeof(rbuf));cout << res << endl;if(res == 0){break;}cout << "rbuf = " << rbuf << endl;}return 0;
}