Thread: EOF Statement in C++

because eof flag is set AFTER the failed read attemp

So 5th successful read will not set the flag even when this record is last one in the file
Next 6th attempt will fail, set the flag to true and leave teh buffer with last read data (from 5th read)

After loop prints that 5th result second time it will exit.

So instead of checking the eof flag - the result of the read operation should be checked

you can implement any other approach that checks the state of the stream before using the read operation result

Code:

   for(;;)
    {
       fileinput >> result;
       if(!fileinput )
       {
          // read failed
          if( fileinput.eof())
          {
             //end of file - just exit the loop
             break;
          }
          if( fileinput.bad())
          {
              //Read/writing error on i/o operation
              //log error and exit the loop

              break;
          }
          if( fileinput.fail())
          {
              //Logical error on i/o operation
              //need to skip mailformed data and continue reading

              ...

              continue;
          }
          break;
       }

       //if we got here - reading was successful - use result
    }

Originally Posted by Vespasian

Thanks.

What other solution is proposed apart from the one mentioned in the link.

I.e. they propose:

while (fileinput >> stream)

Is this the best and only option?

It's certainly not the best. This checks if the read failed, which could be for many reasons.
It's usually a good enough way to do it.