Detect errors in your device.

lserrs.cc

/**
 * Detect errors in your device.
 *
 * Usage: sudo ./lserrs <page size in bytes> <device name>
 */

#include <fcntl.h>
#include <unistd.h>
#include <iostream>
#include <memory>
#include <sstream>

using namespace std;

int main(int argc, char **argv) {
  istringstream is(argv[1]);
  size_t pageSize;
  is >> pageSize;
  auto buffer = make_unique<char[]>(pageSize);
  auto fd = open(argv[2], O_RDONLY);
  auto size = lseek(fd, 0, SEEK_END);
  auto err = false;
  if (size % pageSize) {
    cout << "Wrong page size!" << endl;
    goto fail;
  }
  lseek(fd, 0, SEEK_SET);
  cout << hex;
  for (__off_t i = 0; i < size; i += pageSize) {
    if (err) lseek(fd, i, SEEK_SET);
    if (read(fd, buffer.get(), pageSize) != pageSize) {
      if (err) continue;
      cout << i << '-';
      err = true;
    } else if (err) {
      cout << i << endl;
      err = false;
    }
  }
  if (err) cout << size << endl;
fail:
  close(fd);
  return 0;
}