#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;

int main()
{
//---------readin leak current data-------------------
//
int year,month,day,idata=0;
double tempdata,error;
char line[255];
ifstream fin("ifstream_data.txt");
fin.getline(line,sizeof(line)); // reading the 1st line
ofstream fout("ofstream_data.txt");
while(fin>>year>>month>>day>>tempdata>>error)
{
  cout<<idata<<" "<<year<<" "<<month<<" "<<day<<" : "<<tempdata
  <<" +- "<< error<<endl;
  fout<<idata<<setw(5)<<year<<setw(5)<<month<<setw(5)<<day<<" : "
  <<setw(9)<<tempdata <<" +- "<<setw(9)<< error<<endl;
  idata++;
}
fin.close();
fout.close();
//
return 0;
}

//===============ifstream_data.txt===================-
year month day data error
2010 09 01 8.48         0.
2010 10 19 58.06        0.
2010 11 04 124.952      0.238624
2010 12 03 109.264      0.0717784
2011 01 25 88.0198      0.0186264
2011 02 15 79.58        0.59
2011 05 09 769.455      3.07106
2011 06 11 2315.        10.
2011 08 11 5480.74      21.

//===============compile==================
g++ ifstream.cc

//===============results==========================
$ ./a.exe
0 2010 9 1 : 8.48 +- 0
1 2010 10 19 : 58.06 +- 0
2 2010 11 4 : 124.952 +- 0.238624
3 2010 12 3 : 109.264 +- 0.0717784
4 2011 1 25 : 88.0198 +- 0.0186264
5 2011 2 15 : 79.58 +- 0.59
6 2011 5 9 : 769.455 +- 3.07106
7 2011 6 11 : 2315 +- 10
8 2011 8 11 : 5480.74 +- 21


//---------------output file------------------
0 2010    9    1 :      8.48 +-         0
1 2010   10   19 :     58.06 +-         0
2 2010   11    4 :   124.952 +-  0.238624
3 2010   12    3 :   109.264 +- 0.0717784
4 2011    1   25 :   88.0198 +- 0.0186264
5 2011    2   15 :     79.58 +-      0.59
6 2011    5    9 :   769.455 +-   3.07106
7 2011    6   11 :      2315 +-        10
8 2011    8   11 :   5480.74 +-        21