Method diveToFile

Marlin/src/sd/cardreader.cpp:1165–1248

* Dive to the given DOS 8.3 file path, with optional echo of the dive paths. * * On entry: * - The workDir points to the last-set navigation target by cd, cdup, cdroot, or diveToFile(true, ...) * * On exit: * - Your curDir pointer contains an MediaFile reference to the file's directory. * - If update_cwd was 'true' the workDir now points to the file's directory. * * Returns a pointer t

 *       returned filename will be blank (points to the end of the path).
 */
const char* CardReader::diveToFile(const bool update_cwd, MediaFile* &inDirPtr, const char * const path, const bool echo/*=false*/) {
  DEBUG_SECTION(est, "diveToFile", true);

  // Track both parent and subfolder
  static MediaFile newDir1, newDir2;
  MediaFile *sub = &newDir1, *startDirPtr;

  // Parsing the path string
  const char *atom_ptr = path;

  DEBUG_ECHOLNPGM(" path = '", path, "'");

  if (path[0] == '/') {               // Starting at the root directory?
    inDirPtr = &root;
    atom_ptr++;
    DEBUG_ECHOLNPGM(" CWD to root: ", hex_address(inDirPtr));
    if (update_cwd) workDirDepth = 0; // The cwd can be updated for the benefit of sub-programs
  }
  else
    inDirPtr = &workDir;              // Dive from workDir (as set by the UI)

  startDirPtr = inDirPtr;

  DEBUG_ECHOLNPGM(" startDirPtr = ", hex_address(startDirPtr));

  while (atom_ptr) {
    // Find next subdirectory delimiter
    const char * const name_end = strchr(atom_ptr, '/');

    // Last atom in the path? Item found.
    if (name_end <= atom_ptr) break;

    // Isolate the next subitem name
    const uint8_t len = name_end - atom_ptr;
    char dosSubdirname[len + 1];
    strlcpy(dosSubdirname, atom_ptr, len + 1);

    if (echo) SERIAL_ECHOLN(dosSubdirname);

    DEBUG_ECHOLNPGM(" sub = ", hex_address(sub));

    // Open inDirPtr (closing first)
    sub->close();
    if (!sub->open(inDirPtr, dosSubdirname, O_READ)) {
      openFailed(dosSubdirname);
      atom_ptr = nullptr;
      break;
    }

    // Close inDirPtr if not at starting-point
    if (inDirPtr != startDirPtr) {
      DEBUG_ECHOLNPGM(" closing inDirPtr: ", hex_address(inDirPtr));
      inDirPtr->close();
    }

    // inDirPtr now subDir
    inDirPtr = sub;
    DEBUG_ECHOLNPGM(" inDirPtr = sub: ", hex_address(inDirPtr));