vpIoTools.cpp

/*
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2025 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See https://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * Directory management.
 */

 
// At this point, to make scandir() working as expected on armv7 virtualized on a x86-64bit architecture
// (see github/workflow/other-arch-isolated.yml) we need to define _FILE_OFFSET_BITS=64. Otherwise
// testVideo.cpp will fail.
// Since adding here something like:
//   #include <visp3/core/vpConfig.h>
//   #ifdef VISP_DEFINE_FILE_OFFSET_BITS
//   # define _FILE_OFFSET_BITS 64
//   #endif
// where VISP_DEFINE_FILE_OFFSET_BITS is defined in vpConfig.h doesn't work (my explanation is that the define
// should be done before any other includes; in vpConfig.h there is cstdlib that is included), the other way
// that was retained is to add to vpIoTools.cpp COMPILE_DEFINTIONS _FILE_OFFSET_BITS=64 (see CMakeLists.txt)
 
#include <algorithm>
#include <cctype>
#include <cmath>
#include <errno.h>
#include <fcntl.h>
#include <fstream>
#include <functional>
#include <limits> // numeric_limits
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <visp3/core/vpEndian.h>
#include <visp3/core/vpIoException.h>
#include <visp3/core/vpIoTools.h>
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
#include <dirent.h>
#include <unistd.h>
#elif defined(_WIN32)
#include <direct.h>// Mute warning with clang-cl
// warning : non-portable path to file '<Windows.h>'; specified path differs in case from file name on disk [-Wnonportable-system-include-path]
#if defined(__clang__)
#  pragma clang diagnostic push
#  pragma clang diagnostic ignored "-Wnonportable-system-include-path"
#endif
 
#include <windows.h>
 
#if defined(__clang__)
#  pragma clang diagnostic pop
#endif
 
#endif
#if !defined(_WIN32)
#ifdef __ANDROID__
// Like IOS, wordexp.cpp is not defined for Android
#else
#include <wordexp.h>
#endif
#endif
 
#if defined(__APPLE__) && defined(__MACH__) // Apple OSX and iOS (Darwin)
#include <TargetConditionals.h>             // To detect OSX or IOS using TARGET_OS_IOS macro
#endif
 
#ifndef PATH_MAX
#ifdef _MAX_PATH
#define PATH_MAX _MAX_PATH
#else
#define PATH_MAX 1024
#endif
#endif
 
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
#define VP_STAT stat
#elif defined(_WIN32) && defined(__MINGW32__)
#define VP_STAT stat
#elif defined(_WIN32)
#define VP_STAT _stat
#else
#define VP_STAT stat
#endif
namespace
{
// The following code is not working on iOS since wordexp() is not available
// The function is not used on Android
#if defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))
#if (TARGET_OS_IOS == 0) && !defined(__ANDROID__)
void replaceAll(std::string &str, const std::string &search, const std::string &replace)
{
  size_t start_pos = 0;
  while ((start_pos = str.find(search, start_pos)) != std::string::npos) {
    str.replace(start_pos, search.length(), replace);
    start_pos += replace.length(); // Handles case where 'replace' is a
    // substring of 'search'
  }
}
#endif
#endif
} // namespace
 
BEGIN_VISP_NAMESPACE
  const std::string &vpIoTools::getBuildInformation()
{
  VP_ATTRIBUTE_NO_DESTROY static std::string build_info =
#include "version_string.inc"
    ;
  return build_info;
}

std::string vpIoTools::getTempPath()
{
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  std::string username;
  vpIoTools::getUserName(username);
  return "/tmp/" + username;
#elif defined(_WIN32) && !defined(WINRT)
  // https://docs.microsoft.com/en-us/windows/win32/fileio/creating-and-using-a-temporary-file
  //  Gets the temp path env string (no guarantee it's a valid path).
  TCHAR lpTempPathBuffer[MAX_PATH];
  DWORD dwRetVal = GetTempPath(MAX_PATH /* length of the buffer */, lpTempPathBuffer /* buffer for path */);
  if (dwRetVal > MAX_PATH || (dwRetVal == 0)) {
    throw vpIoException(vpIoException::cantGetenv, "Error with GetTempPath() call!");
  }
  std::string temp_path(lpTempPathBuffer);
  if (!temp_path.empty()) {
    if (temp_path.back() == '\\') {
      temp_path.resize(temp_path.size() - 1);
    }
  }
  else {
    temp_path = "C:\temp";
    try {
      vpIoTools::makeDirectory(temp_path);
    }
    catch (...) {
      throw(vpException(vpException::fatalError, "Cannot set temp path to %s", temp_path.c_str()));
    }
  }
  return temp_path;
#else
  throw vpIoException(vpException::fatalError, "Not implemented on this platform!");
#endif
}

void vpIoTools::getUserName(std::string &username)
{
  // With MinGW, UNIX and _WIN32 are defined
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  // Get the user name.
  char *logname = ::getenv("LOGNAME");
  if (!logname) {
    username = "unknown";
  }
  else {
    username = logname;
  }
#elif defined(_WIN32)
#if (!defined(WINRT))
  unsigned int info_buffer_size = 1024;
  TCHAR *infoBuf = new TCHAR[info_buffer_size];
  DWORD bufCharCount = static_cast<DWORD>(info_buffer_size);
  // Get the user name.
  if (!GetUserName(infoBuf, &bufCharCount)) {
    username = "unknown";
  }
  else {
    username = infoBuf;
  }
  delete[] infoBuf;
#else
  // Universal platform
  username = "unknown";
#endif
#else
  username = "unknown";
#endif
}

std::string vpIoTools::getUserName()
{
  std::string username;
  getUserName(username);
  return username;
}

std::string vpIoTools::getenv(const std::string &env)
{
#if defined(_WIN32) && defined(WINRT)
  throw(vpIoException(vpIoException::cantGetenv, "Cannot get the environment variable value: not "
                      "implemented on Universal Windows Platform"));
#else
  std::string value;
  // Get the environment variable value.
  char *v_value = ::getenv(env.c_str());
  if (!v_value) {
    throw(vpIoException(vpIoException::cantGetenv, "Cannot get the environment variable value"));
  }
  value = v_value;
 
  return value;
#endif
}

void vpIoTools::getVersion(const std::string &version, unsigned int &major, unsigned int &minor, unsigned int &patch)
{
  if (version.size() == 0) {
    major = 0;
    minor = 0;
    patch = 0;
  }
  else {
    size_t major_pos = version.find('.');
    std::string major_str = version.substr(0, major_pos);
    major = static_cast<unsigned>(atoi(major_str.c_str()));
 
    if (major_pos != std::string::npos) {
      size_t minor_pos = version.find('.', major_pos + 1);
      std::string minor_str = version.substr(major_pos + 1, (minor_pos - (major_pos + 1)));
      minor = static_cast<unsigned>(atoi(minor_str.c_str()));
 
      if (minor_pos != std::string::npos) {
        std::string patch_str = version.substr(minor_pos + 1);
        patch = static_cast<unsigned>(atoi(patch_str.c_str()));
      }
      else {
        patch = 0;
      }
    }
    else {
      minor = 0;
      patch = 0;
    }
  }
}

bool vpIoTools::checkDirectory(const std::string &dirname)
{
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  struct stat stbuf;
#elif defined(_WIN32) && defined(__MINGW32__)
  struct stat stbuf;
#elif defined(_WIN32)
  struct _stat stbuf;
#endif
 
  if (dirname.empty()) {
    return false;
  }
 
  std::string path_dirname = path(dirname);
 
  if (VP_STAT(path_dirname.c_str(), &stbuf) != 0) {
    // Test adding the separator if not already present
    if (path_dirname.at(path_dirname.size() - 1) != separator) {
      if (VP_STAT((path_dirname + separator).c_str(), &stbuf) != 0) {
        return false;
      }
    }
    // Test removing the separator if already present
    if (path_dirname.at(path_dirname.size() - 1) == separator) {
      if (VP_STAT((path_dirname.substr(0, path_dirname.size() - 1)).c_str(), &stbuf) != 0) {
        return false;
      }
    }
  }
 
#if defined(_WIN32) || (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__)))
  if ((stbuf.st_mode & S_IFDIR) == 0)
#endif
  {
    return false;
  }
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  if ((stbuf.st_mode & S_IWUSR) == 0)
#elif defined(_WIN32)
  if ((stbuf.st_mode & S_IWRITE) == 0)
#endif
  {
    return false;
  }
  return true;
}

bool vpIoTools::checkFifo(const std::string &fifofilename)
{
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  struct stat stbuf;
 
  std::string v_filename = path(fifofilename);
  if (stat(v_filename.c_str(), &stbuf) != 0) {
    return false;
  }
  if ((stbuf.st_mode & S_IFIFO) == 0) {
    return false;
  }
  if ((stbuf.st_mode & S_IRUSR) == 0)
 
  {
    return false;
  }
  return true;
#elif defined(_WIN32)
  (void)fifofilename;
  throw(vpIoException(vpIoException::notImplementedError, "Fifo files are not supported on Windows platforms."));
#endif
}
 
#ifndef DOXYGEN_SHOULD_SKIP_THIS
int vpIoTools::mkdir_p(const std::string &path, int mode)
{
  errno = 0;
  if (path.size() > PATH_MAX) {
    errno = ENAMETOOLONG;
    return -1;
  }
 
  // Iterate over the string
  std::string cpy_path = path;
  std::string sub_path;
  size_t pos = 0;
  while (pos != std::string::npos) {
    sub_path += cpy_path.substr(0, pos + 1);
    // Continue if sub_path = separator
    bool stop_for_loop = false;
    if (pos == 0) {
      cpy_path.erase(0, pos + 1);
      stop_for_loop = true;
    }
    if (!stop_for_loop) {
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__)))
      if (mkdir(sub_path.c_str(), static_cast<mode_t>(mode)) != 0)
#elif defined(_WIN32)
      (void)mode; // var not used
      if (!checkDirectory(sub_path) && _mkdir(sub_path.c_str()) != 0)
#endif
      {
        if (errno != EEXIST) {
          return -1;
        }
      }
      cpy_path.erase(0, pos + 1);
    }
    pos = cpy_path.find(vpIoTools::separator);
  }
 
  if (!cpy_path.empty()) {
    sub_path += cpy_path;
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__)))
    if (mkdir(sub_path.c_str(), static_cast<mode_t>(mode)) != 0)
#elif defined(_WIN32)
 
    if (_mkdir(sub_path.c_str()) != 0)
#endif
    {
      if (errno != EEXIST) {
        return -1;
      }
    }
  }
 
  return 0;
}
 
#endif // #ifndef DOXYGEN_SHOULD_SKIP_THIS

void vpIoTools::makeDirectory(const std::string &dirname)
{
#if ((!defined(__unix__) && !defined(__unix) && (!defined(__APPLE__) || !defined(__MACH__)))) && !defined(_WIN32)
  std::cerr << "Unsupported platform for vpIoTools::makeDirectory()!" << std::endl;
  return;
#endif
 
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  struct stat stbuf;
#elif defined(_WIN32) && defined(__MINGW32__)
  struct stat stbuf;
#elif defined(_WIN32)
  struct _stat stbuf;
#endif
 
  if (dirname.empty()) {
    throw(vpIoException(vpIoException::invalidDirectoryName, "invalid directory name"));
  }
 
  std::string v_dirname = path(dirname);
 
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  if (stat(v_dirname.c_str(), &stbuf) != 0)
#elif defined(_WIN32) && defined(__MINGW32__)
  if (stat(v_dirname.c_str(), &stbuf) != 0)
#elif defined(_WIN32)
  if (_stat(v_dirname.c_str(), &stbuf) != 0)
#endif
  {
    if (vpIoTools::mkdir_p(v_dirname, 0755) != 0) {
      throw(vpIoException(vpIoException::cantCreateDirectory, "Unable to create directory '%s'", dirname.c_str()));
    }
  }
 
  if (checkDirectory(dirname) == false) {
    throw(vpIoException(vpIoException::cantCreateDirectory, "Unable to create directory '%s'", dirname.c_str()));
  }
}

void vpIoTools::makeFifo(const std::string &fifoname)
{
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
 
  // If dirname is a directory, we throw an error
  if (vpIoTools::checkDirectory(fifoname)) {
    throw(vpIoException(vpIoException::invalidDirectoryName,
                        "Unable to create fifo file. '%s' is an existing directory.", fifoname.c_str()));
  }
 
  // If dirname refers to an already existing file, we throw an error
  else if (vpIoTools::checkFilename(fifoname)) {
    throw(vpIoException(vpIoException::invalidDirectoryName, "Unable to create fifo file '%s'. File already exists.",
                        fifoname.c_str()));
    // If dirname refers to an already existing fifo, we throw an error
  }
  else if (vpIoTools::checkFifo(fifoname)) {
    throw(vpIoException(vpIoException::invalidDirectoryName, "Unable to create fifo file '%s'. Fifo already exists.",
                        fifoname.c_str()));
  }
 
  else if (mkfifo(fifoname.c_str(), 0666) < 0) {
    throw(vpIoException(vpIoException::cantCreateDirectory, "Unable to create fifo file '%s'.", fifoname.c_str()));
  }
#elif defined(_WIN32)
  (void)fifoname;
  throw(vpIoException(vpIoException::cantCreateDirectory, "Unable to create fifo on Windows platforms."));
#endif
}
 
#if defined(_WIN32) && !defined(WINRT)
std::string getUuid();
 
std::string getUuid()
{
  UUID uuid;
  if (UuidCreate(&uuid) != RPC_S_OK) {
    throw(vpIoException(vpIoException::fatalError, "UuidCreate() failed!"));
  }
 
  RPC_CSTR stringUuid;
  if (UuidToString(&uuid, &stringUuid) != RPC_S_OK) {
    throw(vpIoException(vpIoException::fatalError, "UuidToString() failed!"));
  }
 
  return reinterpret_cast<char *>(stringUuid);
}
#endif

std::string vpIoTools::makeTempDirectory(const std::string &dirname)
{
#if defined(WINRT) || !defined(_WIN32) && !(defined(__unix__) || defined(__unix) ||                                    \
                                            (defined(__APPLE__) && defined(__MACH__))) // not UNIX and not Windows
  throw(vpIoException(vpIoException::cantCreateDirectory, "makeTempDirectory() is not supported on this platform!"));
#endif
 
  std::string dirname_cpy = std::string(dirname);
  std::string correctEnding = "XXXXXX";
 
  // If dirname is an unexisting directory, it should end with XXXXXX in order to create a temp directory
  if (!vpIoTools::checkDirectory(dirname_cpy)) {
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
    // Check if dirname ends with XXXXXX
    if (dirname_cpy.rfind(correctEnding) == std::string::npos) {
      if (dirname_cpy.at(dirname_cpy.length() - 1) != '/') {
        dirname_cpy = dirname_cpy + "/";
      }
      try {
        vpIoTools::makeDirectory(dirname_cpy);
      }
      catch (...) {
        throw(vpException(vpException::fatalError, "Cannot create temp directory %s", dirname_cpy.c_str()));
      }
 
      dirname_cpy = dirname_cpy + "XXXXXX";
    }
 
#elif defined(_WIN32) && !defined(WINRT)
    // Remove XXXXXX
    dirname_cpy = dirname_cpy.substr(0, dirname_cpy.rfind(correctEnding));
    // Append UUID
    dirname_cpy = dirname_cpy + getUuid();
#endif
 
  }
  else {
    // If dirname is an existing directory, we create a temp directory inside
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
    if (dirname_cpy.at(dirname_cpy.length() - 1) != '/') {
      dirname_cpy = dirname_cpy + "/";
    }
    dirname_cpy = dirname_cpy + "XXXXXX";
#elif defined(_WIN32) && !defined(WINRT)
    dirname_cpy = createFilePath(dirname_cpy, getUuid());
#endif
  }
 
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  char *dirname_char = new char[dirname_cpy.length() + 1];
  strcpy(dirname_char, dirname_cpy.c_str());
 
  char *computedDirname = mkdtemp(dirname_char);
 
  if (!computedDirname) {
    delete[] dirname_char;
    throw(vpIoException(vpIoException::cantCreateDirectory, "Unable to create directory '%s'.", dirname_cpy.c_str()));
  }
 
  std::string res(computedDirname);
  delete[] dirname_char;
  return res;
#elif defined(_WIN32) && !defined(WINRT)
  makeDirectory(dirname_cpy);
  return dirname_cpy;
#endif
}

bool vpIoTools::checkFilename(const std::string &filename)
{
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  struct stat stbuf;
#elif defined(_WIN32)
  struct _stat stbuf;
#endif
 
  if (filename.empty()) {
    return false;
  }
 
  std::string v_filename = path(filename);
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  if (stat(v_filename.c_str(), &stbuf) != 0)
#elif defined(_WIN32)
  if (_stat(v_filename.c_str(), &stbuf) != 0)
#endif
  {
    return false;
  }
  if ((stbuf.st_mode & S_IFREG) == 0) {
    return false;
  }
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  if ((stbuf.st_mode & S_IRUSR) == 0)
#elif defined(_WIN32)
  if ((stbuf.st_mode & S_IREAD) == 0)
#endif
  {
    return false;
  }
  return true;
}

bool vpIoTools::copy(const std::string &src, const std::string &dst)
{
  // Check if we have to consider a file or a directory
  if (vpIoTools::checkFilename(src)) {
    // --comment: std::cout "copy file: " src " in " dst std::endl;
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
#if TARGET_OS_IOS == 0 // The following code is not working on iOS since
                       // wordexp() is not available
    std::stringstream cmd;
    cmd << "cp -p ";
    cmd << src;
    cmd << " ";
    cmd << dst;
    int ret = system(cmd.str().c_str());
    if (ret) {
    } // to avoid a warning
    // std::cout << cmd << " return value: " << ret << std::endl;
    return true;
#else
    throw(vpIoException(vpException::fatalError, "Cannot copy %s in %s: not implemented on iOS Platform", src.c_str(),
                        dst.c_str()));
#endif
#elif defined(_WIN32)
#if (!defined(WINRT))
    std::stringstream cmd;
    cmd << "copy ";
    cmd << vpIoTools::path(src);
    cmd << " ";
    cmd << vpIoTools::path(dst);
    int ret = system(cmd.str().c_str());
    if (ret) {
    } // to avoid a warning
    // std::cout << cmd << " return value: " << ret << std::endl;
    return true;
#else
    throw(vpIoException(vpException::fatalError, "Cannot copy %s in %s: not implemented on Universal Windows Platform",
                        src.c_str(), dst.c_str()));
#endif
#endif
  }
  else if (vpIoTools::checkDirectory(src)) {
    // --comment: std::cout  "copy directory: "  src  " in "  dst
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
#if TARGET_OS_IOS == 0 // The following code is not working on iOS since
                       // wordexp() is not available
    std::stringstream cmd;
    cmd << "cp -p ";
    cmd << src;
    cmd << " ";
    cmd << dst;
    int ret = system(cmd.str().c_str());
    if (ret) {
    } // to avoid a warning
    // std::cout << cmd << " return value: " << ret << std::endl;
    return true;
#else
    throw(vpIoException(vpException::fatalError, "Cannot copy %s in %s: not implemented on iOS Platform", src.c_str(),
                        dst.c_str()));
#endif
#elif defined(_WIN32)
#if (!defined(WINRT))
    std::stringstream cmd;
    cmd << "copy ";
    cmd << vpIoTools::path(src);
    cmd << " ";
    cmd << vpIoTools::path(dst);
    int ret = system(cmd.str().c_str());
    if (ret) {
    } // to avoid a warning
    // std::cout << cmd << " return value: " << ret << std::endl;
    return true;
#else
    throw(vpIoException(vpException::fatalError, "Cannot copy %s in %s: not implemented on Universal Windows Platform",
                        src.c_str(), dst.c_str()));
#endif
#endif
  }
  else {
    std::cout << "Cannot copy: " << src << " in " << dst << std::endl;
    return false;
  }
}

bool vpIoTools::remove(const std::string &file_or_dir)
{
  // Check if we have to consider a file or a directory
  if (vpIoTools::checkFilename(file_or_dir)
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
    || vpIoTools::checkFifo(std::string(file_or_dir))
#endif
    ) {
    if (::remove(file_or_dir.c_str()) != 0) {
      return false;
    }
    else {
      return true;
    }
  }
  else if (vpIoTools::checkDirectory(file_or_dir)) {
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
#if TARGET_OS_IOS == 0 // The following code is not working on iOS since
                       // wordexp() is not available
    std::stringstream cmd;
    cmd << "rm -rf \"";
    cmd << file_or_dir;
    cmd << "\"";
    int ret = system(cmd.str().c_str());
    if (ret) {
    } // to avoid a warning
    // std::cout << cmd << " return value: " << ret << std::endl;
    return true;
#else
    throw(vpIoException(vpException::fatalError, "Cannot remove %s: not implemented on iOS Platform",
                        file_or_dir.c_str()));
#endif
#elif defined(_WIN32)
#if (!defined(WINRT))
    std::stringstream cmd;
    cmd << "rmdir /S /Q ";
    cmd << vpIoTools::path(file_or_dir);
    cmd << "\"";
    int ret = system(cmd.str().c_str());
    if (ret) {
    } // to avoid a warning
    // std::cout << cmd << " return value: " << ret << std::endl;
    return true;
#else
    throw(vpIoException(vpException::fatalError, "Cannot remove %s: not implemented on Universal Windows Platform",
                        file_or_dir.c_str()));
#endif
#endif
  }
  else {
    std::cout << "Cannot remove: " << file_or_dir << std::endl;
    return false;
  }
}

bool vpIoTools::rename(const std::string &oldfilename, const std::string &newfilename)
{
  if (::rename(oldfilename.c_str(), newfilename.c_str()) != 0) {
    return false;
  }
  else {
    return true;
  }
}

std::string vpIoTools::path(const std::string &pathname)
{
  std::string path(pathname);
 
#if defined(_WIN32)
  for (unsigned int i = 0; i < path.length(); ++i)
    if (path[i] == '/')
      path[i] = '\\';
#elif defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))
  unsigned int path_length = path.length();
  for (unsigned int i = 0; i < path_length; ++i) {
    if (path[i] == '\\') {
      path[i] = '/';
    }
  }
#if TARGET_OS_IOS == 0 // The following code is not working on iOS and android since
  // wordexp() is not available
#ifdef __ANDROID__
// Do nothing
#else
  wordexp_t exp_result;
 
  // escape quote character
  replaceAll(path, "'", "'\\''");
  // add quotes to handle special characters like parentheses and spaces
  wordexp(std::string("'" + path + "'").c_str(), &exp_result, 0);
  path = exp_result.we_wordc == 1 ? exp_result.we_wordv[0] : "";
  wordfree(&exp_result);
#endif
#endif
#endif
 
  return path;
}

std::string vpIoTools::getViSPImagesDataPath()
{
  std::string data_path;
  std::string file_to_test("mbt/cube.cao");
  std::string filename;
  // Test if VISP_INPUT_IMAGE_PATH env var is set
  try {
    data_path = vpIoTools::getenv("VISP_INPUT_IMAGE_PATH");
    filename = data_path + "/" + file_to_test;
    if (vpIoTools::checkFilename(filename)) {
      return data_path;
    }
  }
  catch (...) {
  }
  try {
    data_path = vpIoTools::getenv("VISP_INPUT_IMAGE_PATH") + "/ViSP-images";
    filename = data_path + "/" + file_to_test;
    if (vpIoTools::checkFilename(filename)) {
      return data_path;
    }
  }
  catch (...) {
  }
  try {
    data_path = vpIoTools::getenv("VISP_INPUT_IMAGE_PATH") + "/visp-images";
    filename = data_path + "/" + file_to_test;
    if (vpIoTools::checkFilename(filename)) {
      return data_path;
    }
  }
  catch (...) {
  }
 
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  // Test if visp-images-data package is installed (Ubuntu and Debian)
  data_path = "/usr/share/visp-images-data/ViSP-images";
  filename = data_path + "/" + file_to_test;
  if (vpIoTools::checkFilename(filename)) {
    return data_path;
  }
  data_path = "/usr/share/visp-images-data/visp-images";
  filename = data_path + "/" + file_to_test;
  if (vpIoTools::checkFilename(filename)) {
    return data_path;
  }
#endif
  data_path = "";
  return data_path;
}

std::string vpIoTools::getFileExtension(const std::string &pathname, bool checkFile)
{
  if (checkFile && (vpIoTools::checkDirectory(pathname) || (!vpIoTools::checkFilename(pathname)))) {
    return "";
  }
 
#if defined(_WIN32)
  std::string sep = "\\";
  std::string altsep = "/";
  std::string extsep = ".";
#else
  // On Unix, or on the Mac
  std::string sep = "/";
  std::string altsep = "";
  std::string extsep = ".";
#endif
 
  // Python 2.7.8 module.
  // # Split a path in root and extension.
  // # The extension is everything starting at the last dot in the last
  // # pathname component; the root is everything before that.
  // # It is always true that root + ext == p.
  //
  // # Generic implementation of splitext, to be parametrized with
  // # the separators
  // def _splitext(p, sep, altsep, extsep):
  //    """Split the extension from a pathname.
  //
  //    Extension is everything from the last dot to the end, ignoring
  //    leading dots.  Returns "(root, ext)"; ext may be empty."""
  //
  //    sepIndex = p.rfind(sep)
  //    if altsep:
  //        altsepIndex = p.rfind(altsep)
  //        sepIndex = max(sepIndex, altsepIndex)
  //
  //    dotIndex = p.rfind(extsep)
  //    if dotIndex > sepIndex:
  //        # skip all leading dots
  //        filenameIndex = sepIndex + 1
  //        while filenameIndex < dotIndex:
  //            if p[filenameIndex] != extsep:
  //                return p[:dotIndex], p[dotIndex:]
  //            filenameIndex += 1
  //
  //    return p, ''
 
  int sepIndex = static_cast<int>(pathname.rfind(sep));
  if (!altsep.empty()) {
    int altsepIndex = static_cast<int>(pathname.rfind(altsep));
    sepIndex = std::max<int>(sepIndex, altsepIndex);
  }
 
  size_t dotIndex = pathname.rfind(extsep);
  if (dotIndex != std::string::npos) {
    // The extsep character exists
    size_t npos = std::string::npos;
    if (((sepIndex != static_cast<int>(npos)) && (static_cast<int>(dotIndex) > sepIndex)) ||
      (sepIndex == static_cast<int>(npos))) {
      if (sepIndex == static_cast<int>(npos)) {
        sepIndex = 0;
      }
      size_t filenameIndex = static_cast<size_t>(sepIndex) + static_cast<size_t>(1);
 
      while (filenameIndex < dotIndex) {
        if (pathname.compare(filenameIndex, 1, extsep) != 0) {
          return pathname.substr(dotIndex);
        }
        filenameIndex++;
      }
    }
  }
 
  return "";
}

std::string vpIoTools::getName(const std::string &pathname)
{
  if (pathname.size() > 0) {
    std::string convertedPathname = vpIoTools::path(pathname);
 
    size_t index = convertedPathname.find_last_of(vpIoTools::separator);
    if (index != std::string::npos) {
      return convertedPathname.substr(index + 1);
    }
 
    return convertedPathname;
  }
 
  return "";
}

std::string vpIoTools::getNameWE(const std::string &pathname)
{
  std::string name = vpIoTools::getName(pathname);
  size_t found = name.find_last_of(".");
  std::string name_we = name.substr(0, found);
  return name_we;
}

long vpIoTools::getIndex(const std::string &filename, const std::string &format)
{
  size_t indexBegin = format.find_last_of('%');
  size_t indexEnd = format.find_first_of('d', indexBegin);
  size_t suffixLength = format.length() - indexEnd - 1;
  // Extracting index
  if (filename.length() <= (suffixLength + indexBegin)) {
    return -1;
  }
  size_t indexLength = filename.length() - suffixLength - indexBegin;
  std::string indexSubstr = filename.substr(indexBegin, indexLength);
  std::istringstream ss(indexSubstr);
  long index = 0;
  ss >> index;
  if (ss.fail() || (index < 0) || (!ss.eof())) {
    return -1;
  }
 
  // Checking that format with inserted index equals filename
  char nameByFormat[FILENAME_MAX];
  snprintf(nameByFormat, FILENAME_MAX, format.c_str(), index);
  if (std::string(nameByFormat) != filename) {
    return -1;
  }
  return index;
}

std::string vpIoTools::getParent(const std::string &pathname)
{
  if (pathname.size() > 0) {
    std::string convertedPathname = vpIoTools::path(pathname);
 
    size_t index = convertedPathname.find_last_of(vpIoTools::separator);
    if (index != std::string::npos) {
      return convertedPathname.substr(0, index);
    }
 
    return ".";
  }
  else {
    return "";
  }
}

std::string vpIoTools::toLowerCase(const std::string &input)
{
  std::string out;
#if VISP_CXX_STANDARD > VISP_CXX_STANDARD_98
  const std::string::const_iterator it_end = input.cend();
  for (std::string::const_iterator it = input.cbegin(); it != it_end; ++it) {
#else
  const std::string::const_iterator it_end = input.end();
  for (std::string::const_iterator it = input.begin(); it != it_end; ++it) {
#endif
    out += std::tolower(*it);
  }
  return out;
}

std::string vpIoTools::toUpperCase(const std::string &input)
{
  std::string out;
#if VISP_CXX_STANDARD > VISP_CXX_STANDARD_98
  const std::string::const_iterator it_end = input.cend();
  for (std::string::const_iterator it = input.cbegin(); it != it_end; ++it) {
#else
  const std::string::const_iterator it_end = input.end();
  for (std::string::const_iterator it = input.begin(); it != it_end; ++it) {
#endif
    out += std::toupper(*it);
  }
  return out;
}

std::string vpIoTools::formatString(const std::string &name, unsigned int val)
{
  const char *fmt = name.c_str();
  int sz = std::snprintf(nullptr, 0, fmt, val);
  sz += 1; // note +1 for null terminator
  std::vector<char> buf(sz);
  std::snprintf(buf.data(), sz, fmt, val);
  std::string str(buf.begin(), buf.end());
#if (VISP_CXX_STANDARD >= VISP_CXX_STANDARD_11)
  str.pop_back(); // Only since cxx11
#else
  str.erase(str.end()-1, str.end());
#endif
  return str;
}

std::string vpIoTools::getAbsolutePathname(const std::string &pathname)
{
 
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
  std::string real_path_str = pathname;
  char *real_path = realpath(pathname.c_str(), nullptr);
 
  if (real_path) {
    real_path_str = real_path;
    free(real_path);
  }
  return real_path_str;
#elif defined(_WIN32)
#if (!defined(WINRT))
  std::string real_path_str = pathname;
  DWORD retval = 0;
  TCHAR buffer[4096] = TEXT("");
 
  retval = GetFullPathName(pathname.c_str(), 4096, buffer, 0);
  if (retval != 0) {
    real_path_str = buffer;
  }
  return real_path_str;
#else
  throw(vpIoException(vpException::fatalError,
                      "Cannot get absolute path of %s: not implemented on "
                      "Universal Windows Platform",
                      pathname.c_str()));
#endif
#endif
}

std::string vpIoTools::createFilePath(const std::string &parent, const std::string &child)
{
  if ((child.size() == 0) && (parent.size() == 0)) {
    return "";
  }
 
  if (child.size() == 0) {
    return vpIoTools::path(parent);
  }
 
  if (parent.size() == 0) {
    return vpIoTools::path(child);
  }
 
  std::string convertedParent = vpIoTools::path(parent);
  std::string convertedChild = vpIoTools::path(child);
 
  std::stringstream ss;
  ss << vpIoTools::separator;
  std::string stringSeparator;
  ss >> stringSeparator;
 
  std::string lastConvertedParentChar = convertedParent.substr(convertedParent.size() - 1);
  std::string firstConvertedChildChar = convertedChild.substr(0, 1);
 
  if (lastConvertedParentChar == stringSeparator) {
    convertedParent = convertedParent.substr(0, convertedParent.size() - 1);
  }
 
  if (firstConvertedChildChar == stringSeparator) {
    convertedChild = convertedChild.substr(1);
  }
 
  return std::string(convertedParent + vpIoTools::separator + convertedChild);
}

bool vpIoTools::isAbsolutePathname(const std::string &pathname)
{
  // # Inspired by the Python 2.7.8 module.
  // # Return whether a path is absolute.
  // # Trivial in Posix, harder on the Mac or MS-DOS.
  // # For DOS it is absolute if it starts with a slash or backslash (current
  // # volume), or if a pathname after the volume letter and colon / UNC
  //  resource # starts with a slash or backslash.
  //
  //  def isabs(s):
  //     """Test whether a path is absolute"""
  //     s = splitdrive(s)[1]
  //     return s != '' and s[:1] in '/\\'
  std::string path = splitDrive(pathname).second;
  return (path.size() > 0) && ((path.substr(0, 1) == "/") || (path.substr(0, 1) == "\\"));
}

bool vpIoTools::isSamePathname(const std::string &pathname1, const std::string &pathname2)
{
  // Normalize path
  std::string path1_normalize = vpIoTools::path(pathname1);
  std::string path2_normalize = vpIoTools::path(pathname2);
 
  // Get absolute path
  path1_normalize = vpIoTools::getAbsolutePathname(path1_normalize);
  path2_normalize = vpIoTools::getAbsolutePathname(path2_normalize);
 
  return (path1_normalize == path2_normalize);
}

std::pair<std::string, std::string> vpIoTools::splitDrive(const std::string &pathname)
{
  // # Split a path in a drive specification (a drive letter followed by a
  // # colon) and the path specification.
  // # It is always true that drivespec + pathspec == p
  //  def splitdrive(p):
  //     """Split a pathname into drive/UNC sharepoint and relative path
  //     specifiers. Returns a 2-tuple (drive_or_unc, path); either part may be
  //     empty.
  //
  //     If you assign
  //         result = splitdrive(p)
  //     It is always true that:
  //         result[0] + result[1] == p
  //
  //     If the path contained a drive letter, drive_or_unc will contain
  //     everything up to and including the colon.  e.g. splitdrive("c:/dir")
  //     returns ("c:", "/dir")
  //
  //     If the path contained a UNC path, the drive_or_unc will contain the host
  //     name and share up to but not including the fourth directory separator
  //     character. e.g. splitdrive("//host/computer/dir") returns
  //     ("//host/computer", "/dir")
  //
  //     Paths cannot contain both a drive letter and a UNC path.
  //
  //     """
  //     if len(p) > 1:
  //         normp = p.replace(altsep, sep)
  //         if (normp[0:2] == sep*2) and (normp[2] != sep):
  //             # is a UNC path:
  //             # vvvvvvvvvvvvvvvvvvvv drive letter or UNC path
  //             # \\machine\mountpoint\directory\etc\...
  //             #           directory ^^^^^^^^^^^^^^^
  //             index = normp.find(sep, 2)
  //             if index == -1:
  //                 return '', p
  //             index2 = normp.find(sep, index + 1)
  //             # a UNC path can't have two slashes in a row
  //             # (after the initial two)
  //             if index2 == index + 1:
  //                 return '', p
  //             if index2 == -1:
  //                 index2 = len(p)
  //             return p[:index2], p[index2:]
  //         if normp[1] == ':':
  //             return p[:2], p[2:]
  //     return '', p
 
  // On Unix, the drive is always empty.
  // On the Mac, the drive is always empty (don't use the volume name -- it
  // doesn't have the same  syntactic and semantic oddities as DOS drive
  // letters, such as there being a separate current directory per drive).
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__)))
  return std::pair<std::string, std::string>("", pathname);
#else
  const std::string sep = "\\";
  const std::string sepsep = "\\\\";
  const std::string altsep = "/";
 
  if (pathname.size() > 1) {
    std::string normPathname = pathname;
    std::replace(normPathname.begin(), normPathname.end(), *altsep.c_str(), *sep.c_str());
 
    if (normPathname.substr(0, 2) == sepsep && normPathname.substr(2, 1) != sep) {
      // is a UNC path:
      // vvvvvvvvvvvvvvvvvvvv drive letter or UNC path
      // \\machine\mountpoint\directory\etc\...
      //           directory ^^^^^^^^^^^^^^^
      size_t index = normPathname.find(sep, 2);
      if (index == std::string::npos) {
        return std::pair<std::string, std::string>("", pathname);
      }
 
      size_t index2 = normPathname.find(sep, index + 1);
      // # a UNC path can't have two slashes in a row
      // # (after the initial two)
      if (index2 == index + 1) {
        return std::pair<std::string, std::string>("", pathname);
      }
 
      if (index2 == std::string::npos) {
        index2 = pathname.size();
      }
 
      return std::pair<std::string, std::string>(pathname.substr(0, index2), pathname.substr(index2));
    }
 
    if (normPathname[1] == ':') {
      return std::pair<std::string, std::string>(pathname.substr(0, 2), pathname.substr(2));
    }
  }
 
  return std::pair<std::string, std::string>("", pathname);
#endif
}

std::vector<std::string> vpIoTools::splitChain(const std::string &chain, const std::string &sep)
{
  size_t startIndex = 0;
 
  std::string chainToSplit = chain;
  std::vector<std::string> subChain;
  size_t sepIndex = chainToSplit.find(sep);
 
  while (sepIndex != std::string::npos) {
    std::string sub = chainToSplit.substr(startIndex, sepIndex);
    if (!sub.empty()) {
      subChain.push_back(sub);
    }
    chainToSplit = chainToSplit.substr(sepIndex + 1, chain.size() - 1);
 
    sepIndex = chainToSplit.find(sep);
  }
  if (!chainToSplit.empty()) {
    subChain.push_back(chainToSplit);
  }
 
  return subChain;
}

std::vector<std::string> vpIoTools::getDirFiles(const std::string &pathname)
{
 
  if (!checkDirectory(pathname)) {
    throw(vpIoException(vpException::fatalError, "Directory %s doesn't exist'", pathname.c_str()));
  }
  std::string dirName = path(pathname);
 
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
 
  std::vector<std::string> files;
  struct dirent **list = nullptr;
  int filesCount = scandir(dirName.c_str(), &list, nullptr, nullptr);
  if (filesCount == -1) {
    throw(vpIoException(vpException::fatalError, "Cannot read files of directory %s", dirName.c_str()));
  }
  for (int i = 0; i < filesCount; ++i) {
    std::string fileName = list[i]->d_name;
    if ((fileName != ".") && (fileName != "..")) {
      files.push_back(fileName);
    }
    free(list[i]);
  }
  free(list);
  std::sort(files.begin(), files.end());
  return files;
 
#elif defined(_WIN32)
#if (!defined(WINRT))
 
  std::vector<std::string> files;
  std::string fileMask = dirName;
  fileMask.append("\\*");
  WIN32_FIND_DATA FindFileData;
  HANDLE hFind = FindFirstFile(fileMask.c_str(), &FindFileData);
  // Directory is empty
  if (HandleToLong(&hFind) == ERROR_FILE_NOT_FOUND) {
    return files;
  }
  if (hFind == INVALID_HANDLE_VALUE) {
    throw(vpIoException(vpException::fatalError, "Cannot read files of directory %s", dirName.c_str()));
  }
  do {
    std::string fileName = FindFileData.cFileName;
    if (fileName != "." && fileName != "..") {
      files.push_back(fileName);
    }
  } while (FindNextFile(hFind, &FindFileData));
  FindClose(hFind);
  std::sort(files.begin(), files.end());
  return files;
 
#else
  throw(vpIoException(vpException::fatalError,
                      "Cannot read files of directory %s: not implemented on "
                      "Universal Windows Platform",
                      dirName.c_str()));
#endif
#endif
}
 
END_VISP_NAMESPACE