Thread: Problems with reading the end of a binary file

Hi,

i was given a binary file that i know the format of, which has three double values per line like this:

Code:

<double>   <double>    <double>
<double>   <double>    <double>
<double>   <double>    <double>
      .                    .                      .                      
      .                    .                      .
      .                    .                      .

The three columns are voltage, current and diameter correspondingly.
What I have to do is to create 6 files , 2 each for voltage, current and diameter which is for capturing alternating rows.

Here is my code so far:

Code:

while(1)
    {
      fread(&voltage,sizeof(double),1,ifp); //reading binary file into temporary variables
      fread(&current,sizeof(double),1,ifp);
      fread(&diameter,sizeof(double),1,ifp);
      
      
      
      if (diameter < 0.00000009)
	{
	  
	  //vertexnum = i;
	  //for(i=0; i<vertexnum; i++)
	  // {
	  //printf("%lf %10.29f %10.14f\n", out[i].voltage, out[i].current, out[i].diameter); 
	  //}
	  test = 1;
	  break;
}
    
      
      fprintf(volt1, "%lf\n", voltage);//printing out the values into the corresponding files
      fprintf(amp1, "%10.29f\n", current);
      fprintf(diam1, "%10.14f\n", diameter);

      if(i ==39)
	{
	  fprintf(volt1, "%lf\n", voltage);//printing out the values into the corresponding files
	  fprintf(amp1, "%10.29f\n", current);
	  fprintf(diam1, "%10.14f\n", diameter);
	  
	}

      fread(&voltage,sizeof(double),1,ifp); //reading binary file into temporary variables
      fread(&current,sizeof(double),1,ifp);
      fread(&diameter,sizeof(double),1,ifp);

      fprintf(volt2, "%lf\n", voltage);//printing out the values into the corresponding files

      fprintf(amp2, "%10.29f\n", current);
      fprintf(diam2, "%10.14f\n", diameter);

      if(i ==39)
	{
     fprintf(volt2, "%lf\n", voltage);//printing out the values into the corresponding files
     fprintf(amp2, "%10.29f\n", current);
     fprintf(diam2, "%10.14f\n", diameter);
     
	}
      
      i++;
      //printf("%lf %10.29f %10.14f\n", out[i].voltage, out[i].current, out[i].diameter); //print to screen for verification

    }

where ifp is the file pointer to the file being read, whereas volt1, volt2, amp1, amp2, diam1 and diam 2 are the file being written on. on i =39, a new point is being written to the file. I am not given the number of lines in the binary file, and I have attempted to break the loop by establishing an if loop that said if diameter < 0.00000009, the loop would break. This was solely based on my hypothesis that when its the end of file, the diameter is zero (i know it wouldn't, but its a form of a desparate move). Apparently it will loop on the last line of the data, but since some of the data repeats too so I can't based on it to end the loop either.

So how can I end the loop when it reaches to the end of the binary file?

Thanks

> So how can I end the loop when it reaches to the end of the binary file?
By looking at the return result of fread(), which you're ignoring at the moment.

nevermind, I fixed it with feof function.

> nevermind, I fixed it with feof function.
Did you read the FAQ?
Did you use feof() as the while condition?