for example.. number.txt: (has these contents)
1.75:2.00:3.00
2.00:5.00:7.24
3.00:6.35:1.00
--
my source code is..
#include <stdio.h>
int main()
{
FILE *infile;
double a, b, c;
char d;
double sum;


infile = fopen("number.txt", "r");
if(infile == NULL)
{
printf("number DOES NOT EXISTS!");
}
else
{
while(!foef(infile)) /*here's my problem*/
{
fscanf(infile, "%lf%c%lf%c%lf\n", &a,&d,&b,&d,&c); /*fscanf is used*/
printf("%f %f %f", a, b, c); /*just for checking*/
sum = a + b + c;
printf("sum is %f", sum);
}

}

fclose(infile);
return 0;
}
--
problem is..
if i put the while loop, it won't compile. it has these error message saying "undefined reference to `foef'".
if i remove the while loop, the fscanf reads only the first line.
i would like to read also the other data from line 2 and line 3 and solve their sum respectively.
so how can i loop the the fscanf?(assuming that i don't know how many lines are in the file? or maybe its safe to say to loop the fscanf until EOF?)
thanks a lot!

Oops! you posted the same question twice.

STFW
Here is what I found for you:

while (fscanf(in_fd, "%s", username) != EOF) {
  fprintf(out_fd, "%s\n", username);
}

PS: Remember fscanf returns EOF in case of errors or if it reaches eof. So you can check return value of fscanf instead of feof().