仿dos.cpp

1

#include<string>
#include<iomanip>
#include<iostream>
#include<fstream>
using namespace std;
int main(int argc, char* argv[])
{
	string str1,str2,str3;
	char ch;
	if (argc == 1)
	{
		cout << "Please input the operation: ";
		getline(cin, str1,' ');
	}
	else
		str1 = argv[1];
	if(str1=="mtype")
	{
	   getline(cin, str2);
	    //fstream constructor opens file
	   ifstream  fcin(str2.c_str());
       if(fcin.fail())
	   {
	  //file not found
	   cout<<"the file could not be opened"<<endl;
	  return 1;
	   }
        else  //filter poiter at the first position
	  fcin.seekg(0);
       while(!fcin.eof())   
	   {
		  fcin.get(ch);
		  cout<<ch;
	   }
	   cout<<endl;
	}else
		if(str1=="mcopy")
		{
	   getline(cin, str2,' ');
	   getline(cin, str3);
	   ifstream  fcin(str2.c_str());
	   ofstream fcout(str3.c_str());
       if(fcin.fail())
	   {
	  //file not found
	   cout<<"the file could not be opened"<<endl;
	  return 1;
	   }
        else
			if(fcout.fail())
	   {
	  //file not saved
	   cout<<"the file could not be saved"<<endl;
	  return 1;
	   }
        else  //filter poiter at the first position
	  fcin.seekg(0);
       while(!fcin.eof())   
	   {
		  fcin.get(ch);
		  if(!fcin.eof())
		  fcout.put(ch);
	   }
	}
	else
		if(str1=="mcompare")
		{
	   string compare1="",compare2="";
	   getline(cin, str2,' ');
	   getline(cin, str3);
	   ifstream  fcin(str2.c_str());
       if(fcin.fail())
	   {
	  //file not found
	   cout<<"the file1 could not be opened"<<endl;
	  return 1;
	   }
	  fcin.seekg(0);
       while(!fcin.eof())   
	   {
		  fcin.get(ch);
		  compare1+=ch;
	   }
       ifstream  fcin2(str3.c_str());
       if(fcin2.fail())
	   {
	  //file not found
	   cout<<"the file2 could not be opened"<<endl;
	  return 1;
	   }
	  fcin2.seekg(0);
       while(!fcin2.eof())   
	   {
		  fcin2.get(ch);
		  compare2+=ch;
	   }
	   int f=compare1.compare(compare2);
	   if(f==0)
		   cout<<"they are the same in the content"<<endl;
		   else
			   cout<<"they are not the same in the content"<<endl;
       if(compare1.length()==compare2.length())
		   cout<<"file1 is the same lengh with file2"<<endl;
	   else if(compare1.length()>compare2.length())
		   cout<<"file1 is longer than file2"<<endl;
	   else
		   cout<<"file2 is longer than file1"<<endl;
	}
		else
	{
		cout<<"can not recognise the operation!"<<endl;
		cout<<"please input the operation--mtype--mcopy--mcompare."<<endl;
	    cout<<"for example:"<<endl;
		cout<<setw(10)<<"mtype 123.txt\n"
			<<setw(10)<<"mcopy 123.txt 234.txt\n"
			<<setw(10)<<"mtype 123.txt 234.txt\n";
	}
    return 0;
}