Question

I have a file(both .dat and .txt format) which contains numbers(integers) in rows and columns form. I need to read
numbers(integers) from this file. That data is to be stored in a 2D-array. This array is defined in my C program.
I have tried to use file handling in C to accomplish this, but it is not reading the whole file.
The program stops abruptly at some data in the file and exits the program.
Following is my C code used for this :

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#define EOL '\n'

int main(){

int i = 0,j = 0,array[][];          //i is row and j is column variable, array is the     target 2d matrix 
FILE *homer;
int v;
homer = fopen("homer_matrix.dat","w");   //opening a file named "homer_matrix.dat"
for(i=0;;i++)
  {
   for(j=0;;j++)
    {
            while (fscanf(homer, "%d", &v) == 1)           //scanning for a readable  value in the file
            {
                if(v==EOL)                                      //if End of line occurs , increment the row variable
                   break;
                array[i][j] = v;                                 //saving the integer value in the 2d array defined
            }
        if(v==EOF)
           break;                                                //if end of file occurs , end the reading operation.
    }

  }
fclose(homer);                                                        //close the opened file

for(i=0;i<=1000;i++)
  {
     for(j=0;j<=1200;j++)
        printf(" %d",array[i][j]);                          //printing the values read in the matrix.

   printf("\n");
   }


 }

Thanks Guys for the response, But the issue is something else..
allocated the memory for the 2-d array using the following code:

#define ROW 512

#define CLMN 512


for(i = 0; i <  ROW; i++)

  {

    for(j = 0;  j < CLMN; j++)

        {

array[i][j] = 0;

        }

  }  

Also I modified the permission to ‘r’ in the following code.

homer = fopen(" homer_matrix.txt" , "r"); 

Still, however, I am not able to get the 2-D entries into my variable ‘array’.

p.s. The “homer_matrix.txt” is generated using matlab through following commands:

CODE:

A=imread('homer.jpg');

I=rgb2gray(A);

dlmwrite('homer_matrix.txt',I);

This code will generate the file ‘homer_matrix.txt’ which contains the grayscale values of the image in a 768 X 1024 entry form.

Answer 1

The following code will work for you.
It will calculate exactly how many rows and columns you have in your text file.

do {  //calculating the no. of rows and columns in the text file
    c = getc (fp);

    if((temp != 2) && (c == ' ' || c == '\n'))
    {
        n++;
    }
    if(c == '\n')
    {
        temp =2;
        m++;
    }
} while (c != EOF);
fclose(fp);