How do I read a text file from the second line using fstream?

Question

How can I make my std::fstream object start reading a text file from the second line?

Answer 1

The more efficient way is ignoring strings with std::istream::ignore

for (int currLineNumber = 0; currLineNumber < startLineNumber; ++currLineNumber){
    if (addressesFile.ignore(numeric_limits<streamsize>::max(), addressesFile.widen('\n'))){ 
        //just skipping the line
    } else 
        return HandleReadingLineError(addressesFile, currLineNumber);
}

HandleReadingLineError is not standart but hand-made, of course. The first parameter is maximum number of characters to extract. If this is exactly numeric_limits::max(), there is no limit: Link at cplusplus.com: std::istream::ignore

If you are going to skip a lot of lines you definitely should use it instead of getline: when i needed to skip 100000 lines in my file it took about a second in opposite to 22 seconds with getline.

Answer 2

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

int main () 
{
  char buffer[256];
  ifstream myfile ("test.txt");

  // first line
  myfile.getline (buffer,100);

  // the rest
  while (! myfile.eof() )
  {
    myfile.getline (buffer,100);
    cout << buffer << endl;
  }
  return 0;
}