Example: system_dirs_files_manipulation

C++ example source code:

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2024, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#include <mrpt/io/CFileOutputStream.h>
#include <mrpt/poses/CPose2D.h>
#include <mrpt/poses/CPosePDF.h>
#include <mrpt/system/datetime.h>
#include <mrpt/system/filesystem.h>

#include <iostream>
#include <sstream>
#include <string>

using namespace mrpt;
using namespace mrpt::poses;
using namespace mrpt::io;
using namespace mrpt::system;
using namespace std;

void setupDirContents()
{
  CFileOutputStream f;

  string dir_name = "dir_a";
  string file_name = "file_b";
  CPose2D a_pose(1, 2, 40.0_deg);

  if (!directoryExists(dir_name))
  {
    cout << "Creating directory... " << endl;
    createDirectory(dir_name);
    f.open(dir_name + "/" + file_name, OpenMode::TRUNCATE);
    if (f.fileOpenCorrectly())
    {  // checking for errors...
      cout << "file was opened correctly" << endl;
      // CSerializable form (binary)
      f.printf("some random text ...\n");
      f.printf("some more random text.\n");
      f.printf("CPose2D: %s", a_pose.asString().c_str());
      f.close();
    }
    else
    {
      cout << "file was NOT opened successfully" << endl;
      return;
    }
  }
  else
  {
    cout << "directory " << dir_name << " exists. " << endl;
    cout << "removing directory altogether... " << endl;
    deleteFilesInDirectory(
        dir_name,
        /* deleteDirectoryAsWell = */ true);
  }
}

void renameDirContents()
{
  string dir_name = "dir_b";
  CFileOutputStream f;
  string fname = "file";
  stringstream ss_tmp;

  // get the current datetime as a string - add it to the renamed fnames
  TTimeStamp cur_time(mrpt::Clock::now());
  string cur_time_str = dateTimeToString(cur_time);
  string cur_time_validstr(fileNameStripInvalidChars(cur_time_str));
  string string_to_add = "_renamed_" + cur_time_validstr;

  bool success;  // flag for specifying whether an operation was successfully
  // completed

  if (!directoryExists(dir_name))
  {
    cout << "directory " << dir_name << " doesn't exist. " << endl;
    cout << "Creating it.. " << endl;
    success = createDirectory(dir_name);
    if (!success)
    {
      THROW_EXCEPTION("There was an error creating the directory: " + dir_name);
    }
  }

  // build the initial directory contents
  for (int i = 0; i < 10; i++)
  {
    ss_tmp.str("");
    ss_tmp << dir_name << "/" << fname << i;
    f.open(ss_tmp.str(), OpenMode::TRUNCATE);
    f.printf("dummy text in file...");
    f.close();
  }

  // rename all the contents (of depth 1)
  for (int i = 0; i < 10; i++)
  {
    ss_tmp.str("");
    ss_tmp << dir_name << "/" << fname << i;
    success = renameFile(
        ss_tmp.str(),
        /*new_name = */ ss_tmp.str() + string_to_add);
  }

  // finally rename the directory itself
  cout << "Renaming directory " << dir_name << " to: " << dir_name << string_to_add << endl;
  string* err_msg = nullptr;  // flag for catching the error msg if any..
  success = renameFile(dir_name, dir_name + string_to_add, err_msg);
  if (success)
  {
    cout << "Directory renaming was successful!" << endl;
  }
  else
  {
    THROW_EXCEPTION("Error while trying to rename directory: " + dir_name);
  }
}

//
// MAIN
//
int main()
{
  try
  {
    cout << "Running setupDirContents fun..." << endl;
    cout << "------------------------------" << endl;
    setupDirContents();
    cout << "Press a key to continue..." << endl;
    // char c=
    getchar();

    cout << "Running RenameDirContents fun..." << endl;
    cout << "------------------------------" << endl;
    renameDirContents();

    return 0;
  }
  catch (const std::exception& e)
  {
    std::cerr << "MRPT error: " << mrpt::exception_to_str(e) << std::endl;
    return -1;
  }
}