====== read a file by line ======
<code cpp>
#include <iostream>
#include <string>
#include <fstream>

using namespace std;

bool processFile(const char *filename){
	ifstream reader(filename);

	if( !reader )
		return false;

	string line;
	while( true ){
		getline(reader,line);
		if( !reader.eof() ){
			cout << line << endl;
		}else{
			break;
		}
	}

	reader.close();

	return  true;
}

int main(int argc, const char **argv){

	processFile(argv[1]);

	return 0;
}
</code>

===== build command =====
<code>
c++ -o readfile readfile.cpp
</code>