I am first time using Xcode and C++
I wrote a program which has to load some images. I changed the working directory in the Xcode so the files are located correctly.
But after I build the project and compile it as an application, the external file directory is changed to "usr/[myuser]" (i used char * dir = getcwd(NULL, 0); to get the path)
Does any has an idea how to change the file directory?
Or how can I include these files in the project?
Click on the bar above scheme
Click edit scheme
Checkmark Custom working directory
Choose your directory of choice
Files in this directory are now accessible by the project
Related
I have my project where i am using filesystem to retrieve directory of assets.
When i am lunching my program in editor(im using Visual Studio 2019) everything is fine and this code return value of working direcotry of project.
std::string currentPath = std::filesystem::current_path().string();
But when i am lunching app from .exe file this line of code returns path that leads to .exe file.
The same directory called $TargetPath in properties in VS.
So my question is why is that happening and how can i resolve this problem.Becouse of that i cannot automatically load assets when lounching app from .exe file
Because it gives the current working directory, which is set by the environment calling your program (unless your program explicitly changes it).
So, it does what it's designed to do, gives the current working directory:
Returns the absolute path of the current working directory,
So my question is why is that happening
It happens because you've configured the editor to set the working directory to one path, while you're running the program with another working directory outside the editor.
how can i resolve this problem.Becouse of that i cannot automatically load assets when lounching app from .exe file
Here is an approach:
Store the assets in a path that is relative to the exe.
Get path to the exe.
On POSIX, you can use argv[0] from arguments of main
On Windows, the documentation recommends GetModuleFileNameW
Get canonical absolute form of that path (make sure that working directory hasn't been changed before this step if the path to exe is relative).
Get the directory that contains the exe from that canonical path.
Join that directory path with the asset's relative path to get an absolute path to the asset
Load the asset using the absolute path.
I am a "very" beginner of OpenCV. I just downloaded it for my Windows and extracted.
I have read this post: http://opencv-srf.blogspot.ro/2011/09/capturing-images-videos.html about how to read webcam and I copied and pasted the code in a C++ file I created in "include" folder of OpenCV extracted archive.
When I try to run the program I get this error: Error in: /opencv/build/include/opencv2/highgui/highgui.hpp - opencv2/highgui.hpp: No such file or directory.
What should I do?
Thank you all!
EDIT
I opened: "/opencv/build/include/opencv2/highgui/highgui.hpp" and I can see that it includes this path "opencv2/highgui.hpp". If I change it to "../highgui.hpp" it works but I get other errors like this for other files... What should I do?
The problem is that you are not supposed to create your "cpp" file in the OpenCV "include" directory. You need to create it in a separate directory and then add OpenCV "include" as additional include directory for the compilation step.
The way to achieve this depends on your C++ development environment. If you are using Visual Studio, then you need to open project property pages, go to "C/C++ -> General" and add the path to OpenCV "include" directory to "Additional Include Directories". In case of some other compiler/IDE, you can find out how to do this by reading the corresponding documentation.
I'm trying to use fstream to create a file, however the file i'm trying to create wont appear in the .exe directory or anywhere else in the file directory. After searching in my computer for the file, I found that was created in a different directory entirely even though i'm using a relative directory.
This is the code to create the file:
ofstream file;
file.open("something.jpg", ios::out|ios::binary|ios::beg);
Directory of created file: C:\Users\user-pc
Directory of project: D:\Users\user-pc\Documents\Visual Studio 2012\Projects\recvFile
by the way, using an absolute directory works perfectly fine. Could this be a problem with the projects working directory?
In your Visual Studio right-click on your project, click Properties, then go to Configuration Properties, then Debugging. There is a row "Working Directory". You can set the working directory there. If you need to do this programmatically, you can use SetCurrentDirectory .
If you need to create the file in the same directory as the .exe location, you can use this approach: https://stackoverflow.com/a/124901/1915854
Call GetModuleFileName() using 0 as a module handle...
If the .exe is installed in a shared directory like Program Files, then creation of the file in the same directory could require additional permissions and may be a bad idea. If the .exe is just cloned to the directory where it should create files, then there is no such problem.
Try adding "../" to the link:
file.open("../something.jpg", ios::out|ios::binary|ios::beg);
File will be created in Debug/Release folder of your project. try what Timo Rzipa suggested.
I am working on a project which requires me to open an HTML file and use its contents. I added it to Resource files but when I try to open it lie this:
std::ifstream templateFile;
templateFile.open("filename.html", std::ifstream::in);
The operation fails. I checked it by using templateFile.fail().
The above operation works when I provide the full path. The file lies in the project folder along with other files. I tried setting build action to content but still it doesnt work. Please Help.
Output directory, where your executable is compiled and put into differs from the source directory, where you create all your .cpp/.hpp files (I assume there is filename.html file). Local path filename.html is supposed to be local for your executable file, not the source file.
Read more about changing the output directory here: https://msdn.microsoft.com/en-us/library/ms165410.aspx
Under Configuration Properties / Debugging, see what your Working Directory is using the macros dialog box. Move your file into this folder.
Click the button shown in the figure. There, click either Edit or Browse. Browse will take you to the working directory. Edit will expose the link to open the macros box
I've been using windows in a class I've been taking but I am trying to run a basic code to figure out how to open/close/input/output from files on Xcode and the code I usually use on visual studios isn't working any idea why? thanks!
#include <string>
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
ifstream fin;
ofstream fout;
string input;
fin.open("inputFile.txt");
if(fin.fail())
cout << "File failed to open." << endl;
fin >> input;
fout.open("outputFile.txt");
fout << input;
}
Put your .txt files in the same directory where your main.cpp file is (or anywhere you like).
In Xcode go to Product > Scheme > Edit Scheme > Run (on the left) > Options (middle top)
Down under Options for "Working Directory" check “Use custom working directory” and set it to the directory where you .txt files are located.
To work with the files, you will have to specify just file names, e.g. in_file.open("inputFile.txt"); no path is necessary.
Here's a completely different approach: Have Xcode copy the input file for you.
Select your project in Xcode
Select Build Phases
Click the '+' button to create a new Build Phase
Select New Copy Files Build Phase
Select Products Directory
Click the '+' button to add your file
Click Add Other
Select your input file and click Open
Check the Copy items… checkbox and click Finish
Now every time you build your project, the input file will be copied to the same folder as the executable no matter where it is built. Of course, to see the output file, you'll still need to find the executable in Finder.
The answers don't really explain the problem so I thought I'd do that.
When you pass a relative path like "inputFile.txt" to file APIs, it's treated as relative to the working directory when the program is executed. This is the same as the 'working directory' when you use cmd.exe or Terminal.app or command lines in general. The Unix command pwd ("print working directory") displays the current working directory. On Windows running the command cd with no arguments performs the same function. (On Unix running cd with no arguments will change the working directory to the user's home directory.)
When you run a program from the command line, the command line shell sets the program's working directory. When you run a program from within an IDE, the IDE sets the working directory. Since, unlike on a command line, there's no obvious answer for what the IDE should set as the working directory, Visual Studio and Xcode set the working directory to different locations by default: Visual Studio sets the working directory to $(ProjectDir), the directory containing the Visual Studio project file; Xcode sets the working directory to the build products directory, i.e. the location the executable was written to.
Some possible solutions to your problem are:
Do not use a relative path, and therefore don't depend on the working directory. This isn't much help in making the program more portable, because the absolute paths will also differ between platforms, and so you will still have to 'configure' the program for each platform. In fact using an absolute path is worse, because it means your source code must differ, whereas it would be better to keep that difference confined to each platform's build configuration.
Configure the IDE to use your desired working directory. Visual Studio can be configured by right clicking the project, selecting Configuration Properties > Debugging > Working Directory, and setting the working directory to the desired path (potentially using Visual Studio build variables).
nepete's answer describes how to configure the working directly set by Xcode.
Configure the IDE's build process to copy your data files to an appropriate location. In Visual Studio you would do this in a C++ project by configuring the project's Properties > Configuration Properties > Build Events.
SSteve's answer covers how to configure additional build steps in Xcode.
I'm guessing you have inputFile.txt in the folder that contains your source code. That's not going to work. You need to put it in the folder that contains the generated executable. To find that folder, right-click on your app under Products and select Show In Finder.
This image shows what it looks like for a command line program. It also shows the Finder window that was opened. As you can see, it is a different folder than the one containing the source code.
As suggested by nepete, edit the scheme, but use $PROJECT_DIR as the custom working directory. Helps with moving the project around, or working in two different environments (e.g., home and office).
BTW. $PROJECT_DIR is one of the Xcode Environment Variables, and also helps with passing file names as command line arguments to programs (settable under "Arguments" in the scheme).
I've struggled with the same problem today. I wanted to add C code to my Swift project and my file pointer was always NULL.
Unfortunately, in XCode 9 for iOS app, I couldn't change the working directory. Changing Build phases didn't help me either. After 4+ hours of trial and error, that's what I've come up with finally and it works:
when copying files to XCode, I've chosen "Create groups", but I needed to choose "Create folder references":
I created a new objective-c file (.m) and copied all my C code there.
I left untouched .h files (XCode generated bridging header and my own .h file with public functions declaration). Now my project structure looked like this:
In my dict.m file in place of previous plain c fopen part:
FILE *dic = fopen("dictionary.txt", "r");
I added obj-C code:
NSString *filePath = [[NSBundle mainBundle] pathForResource:#"dictionary" ofType:#"txt"];
FILE *dic = fopen([filePath cStringUsingEncoding: NSUTF8StringEncoding], "r");
And it works now without any problem! It's just amazing!
ps I decided to write this answer in case it will help someone like me and will save them some time. If you know how to change working directory in XCode 9 for iOS, please, leave me a comment - now I am really curious why I can't find it.