char buf[100];
string buf;
ifstream in("目录.txt");
assert(in);
ofstream out("C++.txt");
assert(out);
int i=1;
while(in.get(buf,100))
{
in.get();
cout <<buf <<endl;
out <<i++ <<" : " <<buf <<endl;
}
assert(argc=2);
ifstream in(argv[1]);
assert(in);
in.seekg(0,ios::end);
streampos sp=in.tellg();
cout <<"file size :" <<sp <<endl;
in.seekg(-sp/2,ios::end);
streampos sp2=in.tellg();
cout <<sp2 <<endl;
in.seekg(0,ios::beg);
cout <<in.rdbuf();
in.seekg(sp2);
cout <<endl <<endl <<in.rdbuf()
ifstream in("内容简介.txt");
ofstream out("out.txt");
out <<in.rdbuf();
in.close();
out.close();
ifstream in2("out.txt",ios_base::in|ios_base::out);
ostream out2(in2.rdbuf());
cout <<in2.rdbuf() <<endl;
out2.seekp(0,ios_base::beg);
out2 <<"where does this end up?";
out2.seekp(20,ios_base::end);
out2 <<"and what about this?";