Example: system_dirs_files_manipulation

C++ example source code:

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2021, 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);
        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(getCurrentTime());
    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());
        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;
    }
    catch (...)
    {
        printf("Untyped exception!!");
        return -1;
    }
}