SD File Reuse Snippet

[mattgaidica]

@KravitzLab looking at the current function, it appears it could scan a file to infinity (as long as there are newlines)? Here's a suggestion to stop once the target number of lines are met, see while (file.available() && lineCount < 3):

void FED3::getFilename(char *filename) {
  DateTime now = rtc.now();
  filename[3] = FED / 100 + '0';
  filename[4] = FED / 10 + '0';
  filename[5] = FED % 10 + '0';
  filename[7] = now.month() / 10 + '0';
  filename[8] = now.month() % 10 + '0';
  filename[9] = now.day() / 10 + '0';
  filename[10] = now.day() % 10 + '0';
  filename[11] = (now.year() - 2000) / 10 + '0';
  filename[12] = (now.year() - 2000) % 10 + '0';
  filename[16] = '.';
  filename[17] = 'C';
  filename[18] = 'S';
  filename[19] = 'V';
  for (uint8_t i = 0; i < 100; i++) {
    filename[14] = '0' + i / 10;
    filename[15] = '0' + i % 10;
    if (SD.exists(filename)) {
      // Open the file to check its length
      File file = SD.open(filename, FILE_READ);
      if (file) {
        int lineCount = 0;
        while (file.available() && lineCount < 3) {
          if (file.read() == '\n') {
            lineCount++;
          }
        }
        file.close();
        // If the file has less than 3 lines, delete it
        if (lineCount < 3) {
          SD.remove(filename);
          break;
        }
      } else {
        Serial.println("Error opening file for reading.");
      }
    } else {
      // File doesn't exist, use this filename
      break;
    }
  }
  return;
}