Compare two files

Question

I\'m trying to write a function which compares the content of two files.

I want it to return 1 if files are the same, and 0 if different.

ch1 an

Answer 1

Better to use fread and memcmp to avoid \0 character issues. Also, the !feof checks really should be || instead of && since there's a small chance that one file is bigger than the other and the smaller file is divisible by your buffer size..

int compareFile(FILE* f1, FILE* f2) {
  int N = 10000;
  char buf1[N];
  char buf2[N];

  do {
    size_t r1 = fread(buf1, 1, N, f1);
    size_t r2 = fread(buf2, 1, N, f2);

    if (r1 != r2 ||
        memcmp(buf1, buf2, r1)) {
      return 0;
    }
  } while (!feof(f1) || !feof(f2));

  return 1;
}