How to check if csv file has no data?

Question

I am reading data from a comma delimited csv file. I would like to verify that the file has data before reading and return an error if the file doesn't have any data.

const char* sample_data_file = "sample_data1.csv" ; std::ifstream file(sample_data_file);

Thanks!

Possible duplicate of [Checking for an empty file in C++](http://stackoverflow.com/questions/2390912/checking-for-an-empty-file-in-c) — sashoalm, Nov 25 '16 at 22:49
I tried that, didn't work. std::ifstream file(sample_data_file); if(file.peek() == std::ifstream::traits_type::eof()) cout<<"empty file"< — Steve, Nov 25 '16 at 22:56

score 1 · Answer 1 · answered Nov 25 '16 at 23:49

1

A simple call to stat will tell you if the file is empty. That should be enough to solve your problem.

answered Nov 25 '16 at 23:49

Jesper Juhl

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agent_bean · Answer 2 · 2016-11-25T23:41:48.330

check the size of the file when you open it?

// reading a text file
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main ()
{

  ifstream myfile ("C:/temp/sample1.csv");

  // this gives you the number of bytes in the file.

  if (myfile.is_open())
  {
      long begin, end;

      begin = myfile.tellg();
      myfile.seekg (0, ios::end);
      end = myfile.tellg();

      if(end-begin == 0)
      {
          cout << "file is empty \n";

      }
      else
      {
        cout << "size: " << (end-begin) << " bytes." << endl;
      }

      myfile.close();

  }

  else cout << "Unable to open file \n";

  return 0;
}

How to check if csv file has no data?

2 Answers2