I'm running into some trouble with the copy_file function. My program is very simple, I'm just attempting to copy a text file from one spot to another.
The following code brings up a "Debug Error!" because abort() was called.
int main()
{
path src_path = "C:\\src.txt";
path dst_path = "C:\\dst.txt";
cout << "src exists = " << exists( src_path ) << endl; // Prints True
boost::filesystem::copy_file( src_path, dst_path );
return 0;
}
If I look at some other examples of code on Stackoverflow I cannot notice what I'm doing wrong. I feel like I'm missing something obvious here.
I have Boost v1.47 installed and I'm using Visual C++ 2010.
I'm guessing that the target file exists.
The docs:
template <class Path1, class Path2> void copy_file(const Path1& from_fp, const Path2& to_fp);
Requires: Path1::external_string_type and Path2::external_string_type are the same type.
Effects: The contents and attributes of the file from_fp resolves to are copied to the file to_fp resolves to.
Throws: basic_filesystem_error<Path> if from_fp.empty() || to_fp.empty() || !exists(from_fp) || !is_regular_file(from_fp) || exists(to_fp)
A simple test like so:
#include <iostream>
#include <boost/filesystem.hpp>
int main()
{
using namespace boost::filesystem;
path src_path = "test.in";
path dst_path = "test.out";
std::cout << "src exists = " << std::boolalpha << exists( src_path ) << std::endl; // Prints true
try
{
boost::filesystem::copy_file( src_path, dst_path );
} catch (const boost::filesystem::filesystem_error& e)
{
std::cerr << "Error: " << e.what() << std::endl;
}
return 0;
}
Prints:
src exists = true
Error: boost::filesystem::copy_file: File exists: "test.in", "test.out"
on the second run :)
I think if you are using boost::filesystem2 it should be
boost::filesystem2::copy(src_path,dest_path);
copy_file should have been deprecated.
Related
I wrote a program that copy a file from a given path(s) to another. It runs well until it meets special character in directory names or in file names. At that moment it stops and throws the error that "No such file or directory".
This is what I done until now:
#include <iostream>
#include <vector>
#include <filesystem>
#include <cxxabi.h>
#include <string>
#include <sstream>
#include <memory>
#include <windows.h>
#include <chrono>
#include <thread>
using namespace std;
namespace fs = std::filesystem;
int main(int argc, char **argv) {
vector<string> args(argv + 1, argv + argc);
auto target = args[args.size() - 1];
fs::path path = target;
cout << "Destination path: " << target << endl;
args.erase(args.end());
for (const auto &source : args) {
try {
for (const auto &entry : fs::recursive_directory_iterator(source)) {
std::string new_path = target + "\\" + entry.path().relative_path().string();
//if entry is directory:
while (true) {
if (GetDriveType(const_cast<char *>(path.root_path().string().c_str())) != DRIVE_NO_ROOT_DIR) {
if (fs::is_directory(entry)) {
//only if it NOT exists:
if (!fs::exists(new_path)) {
//create it only if not empty:
if (!fs::is_empty(entry)) {
//Creating directory tree structure with empty folders:
try {
fs::create_directories(new_path);
} catch (const std::exception &e) // caught by reference to base
{
std::cout << "When trying to create directory" << new_path
<< "A standard exception was caught, with message '"
<< e.what() << "'\n";
}
}
}
}
break;
} else {
cout << "Destination path is not available. Sleeping for 3 minutes!" << endl;
std::this_thread::sleep_for(180000ms);
}
}
while (true) {
if (GetDriveType(const_cast<char *>(path.root_path().string().c_str())) != DRIVE_NO_ROOT_DIR) {
if ((fs::is_regular_file(entry)) && (fs::exists(entry))) {
if (!fs::is_empty(entry)) {
if (!fs::exists(new_path)) {
//file does NOT exists in new path:
try {
fs::copy_file(entry.path().string(), new_path);
cout << "Copy file: " << entry.path().string() << endl;
fs::remove(entry);
} catch (const std::exception &e) // caught by reference to base
{
std::cout
<< "When trying to get file size and source a standard exception was caught, with message '"
<< e.what() << "'\n";
}
} else {
//if it exists in new path:
//first try to get file size and if this gives an error then do not copy:
if (fs::file_size(entry.path().string()) >
fs::file_size(entry.path().string())) {
try {
fs::copy_file(entry.path().string(), new_path);
cout << "Replacing file: " << entry.path().string() << endl;
fs::remove(entry);
} catch (const std::exception &e) // caught by reference to base
{
std::cout
<< "When trying to get file size and source a standard exception was caught, with message '"
<< e.what() << "'\n";
}
}
}
}
}
break;
} else {
cout << "Destination path is not available. Sleeping for 3 minutes!" << endl;
std::this_thread::sleep_for(180000ms);
}
}//end while!
}
} catch (const std::exception &e) // caught by reference to base
{
std::cout << "When recursive through directory tree a standard exception was caught, with message '"
<< e.what() << "'\n";
}
}
return 0;
}
After searching on Google and mostly on stackoverflow for a solution conclusion is that none works.
I tried adding #define UNICODE and #define _UNICODE at the top of it but it gives even more errors.
I also added -municode flag in CMakeLists in CLion but also not working (it compiles but gives runtime error).
Also tried to replace all possible string to wstring or wchar_t * with L"where possible" and to convert this entry.path().relative_path().string() to entry.path().relative_path().wstring() and also cout to wcout. Still not working.
Also changed main to wmain( int argc, wchar_t *argv[ ]) or to wmain( int argc, wchar_t *argv[ ], wchar_t *envp[ ] ) and still not working.
Also added setlocale(LC_ALL, ""); after the main function as the other article on stackoverflow says and still no improvement.
I am asking for help because I didn't find a solution for this problem and also, more of the other solution are for printing special unicode characters to console but I need more to work with them (read files names and paths that contain special unicode characters) instead of printing them.
More than this, after I tried all of these possible not working solutions I am talking about above and reverted my program back to the original code that I just posted above now it is not working at all. It says "no such file or directory" even for normal latin characters and doesn't copy or delete anything at all anymore.
Go to the header file in which std::filesystem::path is defined.
(possibly in: PATH_TO_MINGW/usr/include/c++/YOUR_VERSION/bits/fs_path)
Look for using value_type =
Look for compiler macros that define which value_type is ultimately used.
an example from the version from my system:
#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
using value_type = wchar_t;
static constexpr value_type preferred_separator = L'\\';
#else
When the macro _GLIBCXX_FILESYSTEM_IS_WINDOWS is set to 1 then a wchar_t will be used, which should solve your issue.
I am using a boost::shared_ptr to point to a plugin class. Plugin is a map <string, shared_ptr>. The first time I find a certain plugin in the map, it works fine. However, any subsequent time I try to find a particular plugin, I get a SIGSEGV error. When stepping through my code, I get to foundPlugin = a->second->onCommand(command);and find that a->second is not accessible anymore. This error only happens when I am running in Linux, however. I have no issues while running in Windows. Is there some sort of issue with boost::shared_ptr and linux? I have tried using std::shared_ptr, but I have to use a boost::dll::import function that returns a boost::shared_ptr, and I haven't found an alternative for that yet. Any insight is greatly appreciated!
I load plugins like this:
bool PluginManager::loadPlugin(std::string pluginPath, std::string
pluginName, std::string pluginType)
{
bool couldLoad = false;
boost::filesystem::path libPath = boost::filesystem::current_path();
boost::shared_ptr<my_plugin_api> plugin;
std::cout << "Loading the plugin " << pluginName << std::endl;
if (pluginName == "")
{
pluginName = "plugName";
}
try
{
plugin = boost::dll::import<my_plugin_api>(
libPath / pluginName,
pluginType,
dll::load_mode::append_decorations
);
Plugin.insert(std::pair<std::string,boost::shared_ptr<my_plugin_api>>
(pluginName, plugin));
std::cout << "Loading the plugin " << pluginName << " (SUCCESS)" <<
std::endl;
couldLoad = true;
}
catch (const std::exception& e)
{
std::cerr << e.what() << std::endl;
}
return couldLoad;
}
After much more testing, I feel like my problems are in the above section of code. the boost::dll::import function acts as if it finds a .so, but does not return anything in the boost::shared_ptr, which in turn causes the second snippet of code to fail. Any ideas of why this boost::dll::import function might be acting weirdly in Linux?
bool PluginManager::onCommand(const char* command, const char* pluginName)
{
bool foundPlugin = false;
auto a = Plugin.find(pluginName);
if (a == Plugin.end())
{
std::cerr << "plugin " << pluginName << " not found" << std::endl;
}
else
{
foundPlugin = a->second->onCommand(command);
}
return foundPlugin;
}
This question already has answers here:
Create a directory if it doesn't exist
(10 answers)
Closed 3 years ago.
I need to create a text file in my program's subdirectory to write some data. The lines below do not work, the folder is not created. The file is not created even if I create the subfolder manually. Without subfolder in line this command works perfectly.
FILE* f;
if (fopen_s(&f, "/Sandbox/OUTPUT.txt", "w"))
return 1; // Nothing happens
if (fopen_s(&f, "//Sandbox//OUTPUT.txt", "w"))
return 1; // Nothing happens
if (fopen_s(&f, "\\Sandbox\\OUTPUT.txt", "w"))
return 1; // Nothing happens
if (fopen_s(&f, "\Sandbox\OUTPUT.txt", "w"))
return 1; // Nothing happens
if (fopen_s(&f, "Sandbox/OUTPUT.txt", "w"))
return 1; // Nothing happens
if (fopen_s(&f, "Sandbox\OUTPUT.txt", "w"))
return 1; // Creates a file named 'SandboxOUTPUT.txt'
How to code this correctly?
If you have a C++17 enabled compiler, make use of std::filesystem. Here's an introduction to some of the things you can do with it that should be pretty self-explanatory, but if anything is unclear, ask and I'll try to clarify.
#include <filesystem>
#include <fstream>
#include <iostream>
namespace fs = std::filesystem;
int main() {
// create a path in an OS agnostic manner
fs::path dir_path = fs::path(".") / "Sandbox";
fs::directory_entry dir(dir_path);
if(dir.exists()) {
std::cout << dir << " already exists\n";
if(dir.is_directory() == false) {
std::cerr << "... but is not a directory\n";
return 1;
}
} else {
std::cout << "creating dir " << dir << "\n";
if(fs::create_directory(dir) == false) {
std::cerr << "failed creating " << dir << "\n";
return 1;
}
}
{
// create a path to your file:
fs::path filename = dir_path / "OUTPUT.txt";
std::cout << "creating file " << filename << "\n";
std::ofstream os(filename);
if(os)
os << "Hello world.\n";
else {
std::cerr << "failed opening " << filename << " for writing\n";
return 1;
}
}
}
I suppose you're working in a Windows environment.
In case the Sandbox folder is a subdirectory of the current directory, you should use "Sandbox\\OUTPUT.txt" or ".\\Sandbox\\OUTPUT.txt".
If it's a folder within the root of the drive, then use "C:\\Sandbox\\OUTPUT.txt".
In other words, a backslash needs to be escaped by means of another backslash.
If you want to create the directory first, then try:
mkdir(".\\Sandbox") or mkdir("C:\\Sandbox").
I am trying to run a cpp program on raspberry pi 3 b+ (from 'pi' user) but when I try to open a file with 'fstream' library it doesn't work.
I am using the following code (from main):
std::ios::sync_with_stdio(false);
std::string path = "/NbData";
std::ofstream nbData(path);
if (!nbData) {
std::cout << "Error during process...";
return 0;
}
nbData.seekp(std::ios::beg);
The program always fails there and stops because no file is created (I don't get a fatal error but the test fails and it outputs 'Error during process' which means no file was created).
I am compiling with the following command (there are no issues when I compile):
g++ -std=c++0x nbFinder.cpp -o nbFinder
I have already tried my program on Xcode and everything worked perfectly...
The problem is your path. You must put the file, you are using just the path and if the path do not exist will throw an error. In your case you just using std::string path = "/NbData";, that is you path not your file.
To be able to open your file you need make sure your path exist. Try use the code bellow, he will check if the path exist case not will create and then try to open your file.
#include <iostream>
#include <fstream>
#include <sys/types.h>
#include <sys/stat.h>
int main() {
std::ios::sync_with_stdio(false);
std::string path = "./test_dir/";
std::string file = "test.txt";
// Will check if thie file exist, if not will creat
struct stat info;
if (stat(path.c_str(), &info) != 0) {
std::cout << "cannot access " << path << std::endl;
system(("mkdir " + path).c_str());
} else if(info.st_mode & S_IFDIR) {
std::cout << "is a directory" << path << std::endl;
} else {
std::cout << "is no directory" << path << std::endl;
system(("mkdir " + path).c_str());
}
std::ofstream nbData(path + file);
if (!nbData) {
std::cout << "Error during process...";
return 0;
}
nbData.seekp(std::ios::beg);
return 0;
}
I'm using visual studio 2017, running with the c++17 ISO Standard(not boost) set to be able to use <filesystem>. I'm running into a wall though because everytime I run, whether in debug or release, file_copy() gives me the error access denied. I've checked the other bits of my code and the only thing that isn't working is file_copy(). Does anyone know why I'm getting this error and how to fix it? I'm the administrative account on my PC.
std::vector<std::string> findAndCopyFiles()
{
std::vector<std::string> fileNames;
std::error_code errCode;
errCode.clear();
fs::current_path("C:\\Users\\kenny\\Desktop\\Engine", errCode);
std::cout << errCode.message() << std::endl; errCode.clear();
fs::path pa = fs::current_path();
pa += "\\TEMP";
std::cout << pa.string() << std::endl;
if (fs::create_directory(pa, errCode))//Create directory for copying all files)
{
std::cout << "Directory created successfully" << std::endl;
std::cout << errCode.message() << std::endl; errCode.clear();
}
fs::path tempDir(pa);
fs::path currentDirectory = fs::current_path();
fs::recursive_directory_iterator dirIter(currentDirectory);
for (auto &p : dirIter)
{
if (p.path().extension() == ".cpp" || p.path().extension() == ".h")
{
//std::string fileContents = getFileContents(p.path().string());
std::string fileName = p.path().stem().string();
if (!fs::copy_file(p.path(), tempDir, fs::copy_options::overwrite_existing, errCode))
{
std::cout << "failed to copy file: " << fileName << " from " << p.path().string() << " to " << tempDir.string() <<std::endl;
}
std::cout << errCode.message() << std::endl; errCode.clear();
//ensures file is a cpp file before adding it to list of fileNames
if (p.path().extension().string() == ".cpp")
{
auto it = std::find(fileNames.begin(), fileNames.end(), fileName); //seaches TEMP folder for file
if (it == fileNames.end())
{//if file was not found in vector of registered file names, add it
fileNames.push_back(fileName);
}
}
}
}
std::cout << "All files found. " << fileNames.size() << " files were found" << std::endl;
return fileNames;
}
As per the comments. You were trying to overwrite a directory with a regular file. From the documentation [trimmed]
o Otherwise, if the destination file already exists...
o Report an error if any of the following is true:
o to and from are the same as determined by equivalent(from, to);
o to is not a regular file as determined by !is_regular_file(to)
So you need to append the filename to the destination directory path using the `std::filesystem::operator/ overload (untested)...
if (!fs::copy_file(p.path(), tempDir / p.filename(), fs::copy_options::overwrite_existing, errCode))