How do I implement a function to load a dll(aka framework) on Mac OS using C++?
void LoadFramework(const char* frameworkPath)
{
//frameworkPath is the absolute path of the framework
}
Edit:
When I google searched for this problem, I mostly ended up with dlopen solution to load the framework. What I am instead looking for is to use CFBundleCreate to load the framework. It seems to me that there are a bunch of methods needed to be called to construct an URL from const char * path. I found the needed code in pieces, and could not write one comprehensive solution.
It typically is just a few lines of straightforward code to open a framework in Mac, something along the lines of :
bundleURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault,
CFSTR("/System/Library/Frameworks/<your_framework_name.framework>"),
kCFURLPOSIXPathStyle, true);
bundle = CFBundleCreate(kCFAllocatorDefault, bundleURL);
assert(bundle != NULL);
and pretty much everything in that snippet is well documented. I would suggest adding more detail in the question, as to the specifics of what exactly is not working for you.
Why not do this?
using DLL_Namespace;
This should give you access to the DLL.
Related
I have a C++ CLR/CLI project, I wonder how to embed a localized satellite dll into my exe application, I found similar solutions but it's for C# projects which is pretty different from my project structure.
Is it possible to embed it directly into the binary?
By the way I'm getting issues with namespaces, it seems my custom namespace is not linked to my localized resource file.
I've been searching for hours to find a solution for a C++ CLR/CLI project which is pretty different comparing with C# projects which apparently comes with Build Action and Custom Tool Namespace all these options we don't have in a CLR/CLI project, it's really important, especially if we have changed Namespaces so we gotta use Resource Logical Name instead. Here's my answer how to solve Namespace issues, this also works for localized resource files linked to satellite dlls.
After your localized satellite dll is generated, include that in your project as Compiled Managed Resource you can set that by opening its file property and setting the Item Type. In projects such as C# you won't find that but something similar like "Embedded Resource". Anyways this is intended to C++ CLR/CLI projects only. If you have changed namespaces, don't forget to set Resource Logical Name of the respective resource file.
Next step is to do some code in order to embed that dll into our exe application, here's a good one for that:
Since C++ CLR/CLI doesn't support lambda expressions we have to do this way:
private: System::Reflection::Assembly^ currentDomainAssemblyResolve(System::Object^ sender, System::ResolveEventArgs^ args) {
System::Reflection::AssemblyName^ assemblyName = gcnew System::Reflection::AssemblyName(args->Name);
System::String^ resourceName = assemblyName->Name + ".dll";
System::IO::Stream^ stream = System::Reflection::Assembly::GetExecutingAssembly()->GetManifestResourceStream(resourceName);
array<Byte>^ assemblyData = gcnew array<Byte>((unsigned long) stream->Length);
try {
stream->Read(assemblyData, 0, assemblyData->Length);
} finally {
if (stream != nullptr) delete stream;
}
return System::Reflection::Assembly::Load(assemblyData);
}
Usage:
//Put it in your constructor before InitializeComponent()
MyClass(void) {
AppDomain::CurrentDomain->AssemblyResolve += gcnew System::ResolveEventHandler(this, &MyNameSpace::MyClass::currentDomainAssemblyResolve);
InitializeComponent();
}
So now it's no longer necessary satellite dlls to load your localized resources.
Use a free application packer to bundle files into a single exe.
https://enigmaprotector.com/en/aboutvb.html
This one is free, I use it and it works very well for me.
How do I get the list of open file handles by process id in C#?
I'm interested in digging down and getting the file names as well.
Looking for the programmatic equivalent of what process explorer does.
Most likely this will require interop.
Considering adding a bounty on this, the implementation is nasty complicated.
Ouch this is going to be hard to do from managed code.
There is a sample on codeproject
Most of the stuff can be done in interop, but you need a driver to get the filename cause it lives in the kernel's address space. Process Explorer embeds the driver in its resources. Getting this all hooked up from C# and supporting 64bit as well as 32, is going to be a major headache.
You can also run the command line app, Handle, by Mark Rusinovich, and parse the output.
Have a look at this file :
http://vmccontroller.codeplex.com/SourceControl/changeset/view/47386#195318
And use:
DetectOpenFiles.GetOpenFilesEnumerator(processID);
Demo:
using System;
using System.Diagnostics;
namespace OpenFiles
{
class Program
{
static void Main(string[] args)
{
using (var openFiles = VmcController.Services.DetectOpenFiles.GetOpenFilesEnumerator(Process.GetCurrentProcess().Id))
{
while (openFiles.MoveNext())
{
Console.WriteLine(openFiles.Current);
}
}
Console.WriteLine();
Console.ReadKey();
}
}
}
It has dependency over assembly System.EnterpriseServices
You can P/INVOKE into the NtQuerySystemInformation function to query for all handles and then go from there. This Google groups discussion has details.
Take a look at wj32's Process Hacker version 1, which can do what you asked, and more.
Handle is great program, and the link to codeproject is good.
#Brian
The reason for the code is that handle.exe is NOT redistributable. Nor do they release their source.
It looks as if .Net will not easily do this since it appears that an embedded device drive is requried to access the information. This cannot be done in .net without an unmanged DLL. It's relatviely deep kernel code when compared to typical .net coding. I'm surprised that WMI does not expose this.
Perhaps using command line tool:
OpenedFilesView v1.50 - View opened/locked files in your system (sharing violation issues)
http://www.nirsoft.net/utils/opened_files_view.html
In the application that I am developing (using C++ and Qt), I am using QApplication::applicationDirPath() to access some resources, with respect of the application's path.
As an example, since I want to open a HTML manual from the application, I act this way:
void MainWindow::on_actionHelp_triggered()
{
QString link = QApplication::applicationDirPath() + "/Guide/guide.html";
bool r = QDesktopServices::openUrl(QUrl::fromLocalFile(link));
}
This snippet works if the project's structure presents the path "ProjectName/bin/Release/Guide/guide.html" (since the .exe file is in "ProjectName/bin/Release/AppName.exe").
But what can I do to refer to a higher-directory-level resource? As an example, I wish my HTML file to be in "ProjectName/data/Guide/guide.html". But this way, it seems not possible to compose the path in the way I'm acting.
EDIT: After #olive's comment, I wish to clarify a thing:
"Why am I not using '../'?"
Because it won't work from Visual Studio, where I am massively launch the application to test it. From VS, in fact, I shall use "../data/Guide/guide.html", when "from the outside", I'd have to do "../../data/Guide/guide.html".
That's why (I think) QApplication::applicationDirPath() exists. However, I am not an expert, so don't blame me and correct any eventual mistake of mine, please!
Just use ... QApplication::applicationDirPath() + "/../../data/Guide/guide.html" is perfectly valid path!
Of course there is another problem. When the application is installed, the relative path will probably be different again. You either need to configure the paths in visual studio so that the relative path works both during development and after deployment, or you need to detect the layout.
I'm wondering if there is a way to get a reference to the Documents folder on iOS using just C++ (i.e. WITHOUT using ANY code in Objective-C; this because it is a framework implemented only in C++ that can be add as a library in a iOS project).
Please, if it is possible, provide code in your answer.
With code below I able to access cache folder in my app. I think, documents folder in "/Library/Documents", or somewere else.
char *home = getenv("HOME");
char *subdir = "/Library/Caches/subdir";
home + subdir = full path
Next, with full path, you can do usual things to read/write in C++
Yes, you have access to the plain Unix APIs. See Apples iOS manpages here.
Get the path (using Cocoa APIs), then convert it to a C++ string compatible representation using and API such as: CFStringGetFileSystemRepresentation, CFURLGetFileSystemRepresentation, or -[NSString fileSystemRepresentation].
Something like:
// you may need to wrap this in an autorelease pool
NSArray * paths(NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES));
const char* const path([[paths objectAtIndex:0] fileSystemRepresentation]);
if (0 == fsrep) {
uh-oh
}
const std::string result(path);
Then you can simply put that in its own ObjC++ translation and return result from the function (which would be visible to the rest of your C++ sources).
I am currently writing an application that will serve a similar purpose for multiple clients, but requires adaptations to how it will handle the data it is feed. In essence it will serve the same purpose, but hand out data totally differently.
So I decided to prodeed like this:
-Make common engine library that will hold the common functionalities of all ways and present the default interface ensuring that the different engines will respond the same way.
-Write a specific engine for each way of functioning....each one compiles into its own .dll.
So my project will end up with a bunch of libraries with some looking like this:
project_engine_base.dll
project_engine_way1.dll
project_engine_way2.dll
Now in the configuration file that we use for the user preferences there will an engine section so that we may decide which engine to use:
[ENGINE]
Way1
So somewhere in the code we will want to do:
If (this->M_ENGINE == "Way1")
//load dll for way1
Else If (this->M_ENGINE == "Way2")
//load dll for way2
Else
//no engines selected...tell user to modify settings and restart application
The question is...How will I import my dll(s) this way? Is it even possible? If not can I get some suggestions on how to achieve a similar way of functioning?
I am aware I could just import all of the dlls right at the start and just choose which engine to use, but the idea was that I didn't want to import too many engines for nothing and waste resources and we didn't want to have to ship all of those dlls to our customers. One customer will use one engine another will use a different one. Some of our customer will use more than one possibly hence the reason why I wanted to externalize this and allow our users to use a configuration file for engine switching.
Any ideas?
EDIT:
Just realized that even though each of my engine would present the same interface if they are loaded dynamically at runtime and not all referenced in the project, my project would not compile. So I don't have a choice but to include them all in my project don't I?
That also means they all have to be shipped to my customers. The settings in the configuration would only dictate with class I would use to initialize my engine member.
OR
I could have each of these engines be compiled to the same name. Only import one dll in my main project and that particular engine would be used all the time. That would render my customers unable to use our application for multiple clients of their own. Unless they were willing to manually switch dlls. Yuck
Any suggestions?
EDIT #2:
At this point seeing my options, I could also juste make one big dll containing the base engine as well as all the child ones and my configuration to let the user chose. Instead of referencing multiple dlls and shipping them all. Just have one huge one and ship/reference that one only. I am not too fond of this either as it means shipping one big dll to all of my customers instead of just one or two small ones that suit there needs. This is still the best solution that I've come up with though.
I am still looking for better suggestions or answers to my original question.
Thanks.
Use separate DLLs for each engine and use LoadLibrary in your main project to load the specific engine based on the configuration.
Have your engine interface in some common header file that all engines will derive from and this interface will be used in your main project aswell.
It might look like this:
// this should be an abstract class
class engine {
public:
virtual void func1() = 0;
virtual void func2() = 0;
...
};
In each different engine implementation export a function from the DLL, something like this:
// might aswell use auto_ptr here
engine* getEngine() { return new EngineImplementationNumberOne(); }
Now in your main project simply load the DLL you're interested in using LoadLibrary and then GetProcAddress the getEngine function.
string dllname;
if (this->M_ENGINE == "Way1")
dllname = "dllname1.dll";
else if (this->M_ENGINE == "Way2")
dllname = "dllname2.dll";
else
throw configuration_error();
HMODULE h = LoadLibraryA(dllname.c_str());
typedef engine* (*TCreateEngine)();
TCreateEngine func = (TCreateEngine)GetProcAddress(h, "getEngine");
engine* e = func();
The name of the exported function will probably get mangled, so you could either use DEF files or extern "C" in your DLLs, also don't forget to check for errors.
The solution I came to is the following:
Engine_Base^ engine_for_app;
Assembly^ SampleAssembly;
Type^ engineType;
if (this->M_ENGINE == "A")
{
SampleAssembly = Assembly::LoadFrom("path\\Engine_A.dll");
engineType = SampleAssembly->GetType("Engine_A");
engine_for_app = static_cast<Engine_Base^>(Activator::CreateInstance(engineType, param1, param2));
}
else
{
SampleAssembly = Assembly::LoadFrom("path\\Engine_B.dll");
engineType = SampleAssembly->GetType("Engine_B");
engine_for_app = static_cast<Engine_Base^>(Activator::CreateInstance(engineType, param1, param2, param3, param4));
}
I used the answer from Daniel and the comments that were made on his answer. After some extra research I came across the LoadFrom method.