If you still need to find line breaks, you could search for the appropiate line break control characters (CR & LF) in your STRING:
Code:
char *char_array = your_string->chars;
int i;
for (i = 0; char_array[i]; i++)
{
if ((char_array[i] == 13) && (char_array[i + 1] == 10))
{
printf("line break found at position %i", i + 1);
i++;
}
}