Thread: repeated value in file

#include <stdio.h>
#include <stdlib.h>

int main()
{
int count=0;
float data, compare = -9999.0;

FILE *fptr1, *fptr2;

if((fptr1 = fopen("hello.dat", "r")) == NULL)
{
printf("Error opening file\n");
exit(1);
}

if((fptr2 = fopen("hello1.dat", "w")) == NULL)
{
printf("Error opening file1\n");
exit(1);
}

else
{
while( !feof(fptr1) )
{
fread(&data, sizeof(float), 1, fptr1);

if(data > compare)
compare = data;

fwrite(&data, sizeof(float), 1, fptr2);
count++;
}

fprintf(fptr2, "\n\n%s", "Max float number = ");
fprintf(fptr2, "%d\n\n", compare);
fprintf(fptr2, "%s", "No of float values = ");
fprintf(fptr2, "%d\n", count);

fclose(fptr1);
fclose(fptr2);
}
return 0;
}

Here are my problems:
I don't know why when 'hello1.dat' was created, the last value of 'hello.dat' was repeated twice? I have ensured that no new line was entered at the last value when creating this 'hello.dat' file.

I also don't know why it didn't print out the 'compare' value?

hello.dat is just number of values of float.

Thanks for your help, Quzah!


>>I also don't know why it didn't print out the 'compare' value?
Mistake:

fprintf(fptr2, "%d\n\n", compare);

The conversion specifier should be %f not %d. Anyway, it still couldn't print the largest float numbers eventhough I had changed it to %f.

Are you sure you're reading a binary file, and writing a text file?

You might need
if((fptr1 = fopen("hello.dat", "rb")) == NULL)