Tricky machine code

#include<cstdio>#include<fstream>#include<iomanip>#include<iostream>using namespace std;int main(){ifstream ifs("L7_F0_P4a.dat",ios::binary);if(!ifs){cout<<"Error opening file\n";return 1; } int len;unsigned char txt[16];while(ifs){ifs.read(reinterpret_cast<char*>(txt),16);//将txt强制转化成指向字符数组的指针 cout<<"txt:"<<txt<<endl;//所以这里是默认变成16进制了！quite funny len=ifs.gcount();cout<<"len:"<<dec<<len<<endl;if(len==0) break;for(int i=0;i<len;i++){//cout <<setfill('0')<<setw<<hex<<static_cast<int>(txt[i]-48)<<" ";cout<<setfill('0')<<setw(2)<<hex<<static_cast<int>(txt[i]-'0')<<" ";}//$$$cout<<"| ";for(int i=0;i<len;i++){if(txt[i]=='\n'||txt[i]=='\r'||txt[i]=='\b'||txt[i]=='\a'){cout<<'.';}else{cout<<txt[i];}}cout<<" |"<<endl;len=0;txt[0]='\0';}ifs.close();return 0;}