Thread: Where's my seg fault?

Code:

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

int main(void)

{

 
FILE *ofp;

FILE *ifp;


int input;
int sum = 0;
int output[60];
char filename[50];


//Opens the file being printed to
 
ofp = fopen("output.dat", "w");

if(ofp == NULL)
   {

    printf("Unable to open output.dat for writing\n");
    exit(1);

   }


//Opens up the file with numbers in it

ifp = fopen("pix.dat", "r");


if(ifp == NULL)
   {

    printf("Unable to open pix.dat\n");
    exit(1);

   }

int i = 0;

fscanf(ifp, "%d", &input);

while ( !feof(ifp) )
{
  
  printf("test");
  output[i] = input;
  
  i++;
  sum++;
  fscanf(ifp, "%d", &input);
}

Cprogramming.com FAQ > Why it's bad to use feof() to control a loop

Likely "i" is greater than 59

Code:

output[i] = input;

Tim S.

Originally Posted by Tclausex

Cprogramming.com FAQ > Why it's bad to use feof() to control a loop

I know that's bad. That's not where the seg fault is happening though. I'm not focused on proper practice of feof(). Thank you for the useful info though!

Look up fscanf() in your C library documentation (What's that? Don't have it? Get it!) and pay special attention to the value it returns.

Code:

int i, sum;

i = 0;
sum = 0;
while ( fscanf(ifp, "%d", &input) > 0 )
{
  output[i] = input;
  i++;
  sum += input;
}