Thread: Reading Lines from a file

Hey everybody, I want to be able to read lines of data from a text document and store it in a array and output the array in a file. does know how to skip whitespace when reading data from a file. The data i want to read is below

Forsyth, Frederick ;The fist of god ;A;102391
Follett, Ken ;The pillars of the earth ;A;103795
Francis, Clare ;Wolf winter ;A;112424
Smith, Wilbur ;A falcon flies ;A;151395
Forsyth, Frederick ;The day of the jackal ;A;159151
Blackmore, R.D. ;Lorna Doone ;A;193292
Smith, Wilbur ;Men of men ;A;292351
Smith, Wilbur ;The angels weep ;A;482315
James, P.D. ;Cover her face ;D;144371
James, P.D. ;Devices and desires ;D;193395
Kellerman, Faye ;Stone kiss ;D;434517
James, P.D. ;The skull beneath the skin ;D;439518
Kelly, Jim ;The water clock ;D;543951
Hoag, Tami ;Dark horse ;D;664333
Cookson, Catherine ;The silent lady ;R;151611
Cookson, Catherine ;Kate hannigans girl ;R;165163
Thompson, E.V. ;The lost years ;R;165213
Steel, Danielle ;The cottage ;R;177516
Binchley, Maeve ;Quentins ;R;261561
Alcott, Louisa ;Little women ;R;395104
Cookson, Catherine ;Rosie of the river ;R;512843
Asimov, Isaac ;Foundation ;S;165108
Barker, Clive ;Imajica ;S;172816
Barker, Clive ;The great and secret show ;S;174427
Barker, Clive ;Weaveworld ;S;282118
Clarke, Arthur C ;2001 A space odessy ;S;294561
Asimov, Isaac ;Foundation and empire ;S;313178
Asimov, Isaac ;Second foundation ;S;549201

And here is the code i have done so far. what i am doing wrong.

Code:

#include <string>
#include <fstream.h>
#include <assert.h>
#include <iostream>
#include <stdlib.h>
using namespace std;

const int max = 5000;

struct book // holds book details
{
  string secondname;
  string firstname;
  string title;
  char cat;
  int bnumber;
};

int main (int argc, char* argv[])
{
  assert (argc >= 1); // type book data filename
  ifstream accfile (argv[1]); //opens book data
  book b[max];
  int counter = 0;
do 
  {
    accfile >> b[counter].secondname >> b[counter].firstname
            >> b[counter].title >> b[counter].cat >> b[counter].bnumber //stores it in array b   
    if (accfile)
      {
	counter++;
      }
  } while (accfile && counter < max);
 cout << counter << " read" << endl;
 accfile.close();

 ofstream oaccfile("search.txt");

 // write data to a new file

 for ( int i = 0; i < counter; i++ )
   {
     oaccfile << b[i].secondname << " " << b[i].firstname << " " << b[i].title
	      << b[i].cat << " " << b[i].bnumber << endl;
   }
 oaccfile.close() ;
 cout << "Output file created: Seacrh.txt" << endl ;
}

>> what i am doing wrong.

First, it should be <fstream>, not <fstream.h>. Second, as willc0de4food mentioned you are missing a semicolon. Once you fix these two things and the code compiles, I assume you are having trouble reading in the data in its current format.

What you should use is getline (not fgets) to read in part of the line without stopping at whitespace. To get the secondname, you would read until you found a comma, which can be done with getline(accfile, b[counter].secondname, ','). The first name would be up to the next semi-colon, so you would do something similar: getline(accfile, b[counter].firstname, ';').

You could do the same for the title, and then use operator >> to read in the category char and the bnumber int. If you sprinkle in a few accfile.get() calls to ignore characters you don't need (like the semicolon between the category and the bnumber or the newline at the end of each line), then you will have it working.

So play around with getline, operator>> and get. If you can understand how they work it won't be too difficult to combine them to get all the data from the file correctly.

Thank you willc0de4food and Daved for your help
i didn't expect such a quick response for my Thread

The code works fine thanks to both responses.