I am required to parse a text file in my VS project in mfc in c++. The text file is supposed to be a part of the entire exe product. For that purpose, I placed the text file in my resources folder and set the path in my code as:
char fileName[] = "../myFile.txt";
The problem I'm facing is that VS doesn't find this file in its Resources folder. I added the file in the project file, but that just gave me a corrupt file error. However, the file access works if I provide the absolute path to the file in my code i.e. "C/abc/myFile.txt"
I need the code running on all machines, hence need some method to get VS to read this file using a relative path. Can anybody please provide some assistance? I am a newbie and have tried all that's in my knowledge.
Actually, if it's a resource file it should be copied over to the bin folder, which means your fileName should just be:
char fileName[] = "myFile.txt";
if that doesn't work then, you might need to change the properties of your myFile.txt to ensure it does get copied over with the build process.
Here you can find an answer for your question: http://www.cplusplus.com/forum/general/54255/
Related
I have tried to use QFile to open a text file:
I tried
QFile file("serial_deviceIP.txt");
but the file.open() returns false.
However, if I switched to a global address like:
QFile file("C:/Users/shupeng/Documents/qgroundcontrol_peidong_mod/serial_deviceIP.txt");
it works. Why? How can I solve this?
In the first instance, the path to the file cannot be found.
QFile file("serial_deviceIP.txt");
This specifies the file with a relative path, and will only work if serial_deviceIP.txt is in the current working directory, which is likely to be the directory that contains the executable of your program.
QFile file("C:/Users/shupeng/Documents/qgroundcontrol_peidong_mod/serial_deviceIP.txt");
This is referencing an absolute file path, so the file will be found
You can also use Qt's Resource System to bundle the files with your application.
Create a .qrc file in your project and add any file you wish to use/load in your application to it.
Then you can load your file as:
QFile file( ":myfiles/serial_deviceIP.txt" );
See QT Resource System for more information.
What happens is that when we are developing our code we usually keep our project source dir on mind as the reference so we don't give an absolute path, but after building the current directory will change and it will be the build directory, so our application won't find the files without a absolute path.
A possible solution is to add a Resources in our project including our project directory. So just add the following line in the project_file.pro:
RESOURCES += ./
and then use the character : before the file's name when you go to read it, like it:
QFile foo(":bar.txt")
That just work for read it but not for write. So to write is necessary specify an absolute path.
Is there any way so that i can get extension of a given file.
if suppose there is a file "abc.txt" but after renaming the file name is "abc.exe" now the extension is .exe is there any way that i can get the original extension of a file in which it was created.
I looked for GetFileInformationByHandle but that was not much of help
is there any way that i can get the original extension of a file in which it was created
No, not without any operating system add-ons or a simple backup of the file
.
When I run the Debug in Visual Studio for a project, fopen function works fine. It tries to open a file contained in the project and that I added in the filter "Resources".
But when I run .EXE file of my project, I get the null pointer exception: 0x000005c.
When I added the file to be in the same directory as my .EXE file, the exception disappeared.
This is the instruction I use :
fopen(&filename, "rb");
I know it is adviced to use fopen_s instead, but the file is not found anyway...
Apparently, the file is searched always in the current directory...
So, how to include the file in .EXE and make the path of the file relative to the .EXE, at a way it will be contained in the .EXE and not added to the directory where there is .EXE?
You can't include the file in the .exe. You just need to make sure that the file is in the same directory as the .exe.
If you really, really want to only use one file, you could either:
Zip the .exe and the text file together and make sure you include in a readme that the text file needs to be in the same location as the .exe
Use an array/struct/some other way of storing the contents of the file in the program itself, and reference that instead of using a file (I assume you don't care about users being able to edit this data outside of an instance of the program since you wanted it bundled with an executable, so the file is unnecessary in that case)
The reason the program only works when you put the file in the directory of the .exe is because the path to the file is defined in the program as something like .\file.txt or file.txt. When the file isn't in the same directory as the .exe, the program will try to find it, and will be unable to, which is why you get the error. It works when you debug because you have a copy of the text file in the same location as the debug .exe.
EDIT: I would also ignore the warnings about fopen_s and other variant's that append a _s to the end of a command - these are windows specific, non-standard, and in most cases, pointless. If you know this program will only be used in windows environments and you're not doing something for school where you are required to write standard code, I suggest you use the _s variants for the sake of security, but it will reduce portability of your code.
I need to create a temp file in a specified folder on MAC. However I am able to create the folder at the correct location but not able to create the file inside. I get an error saying it does not have permissions to create the file although i have passed 777 as file permission while creating the folder. please find my code below. I would like to mention that this problem is only on MAC. On windows it executes as expected. please let me know what the issue is.
wxString curDir = SeeWorkingDir() + wxT("Temp\\"); //Gets the working directory
if(!wxFileName::DirExists(curDir)) //Checks if directory exists
wxFileName::Mkdir( curDir, 0777, wxPATH_MKDIR_FULL ); // creates the directory
wxString jobcopy = wxFileName::CreateTempFileName(curDir); // should create temp file
I have absolutely no idea what your "SeeWorkingDir()" function is returning, but if it's returning the application directory then you shouldn't be writing anything into there.
Why not replace "SeeWorkingDir()" with a path to somewhere on the Macintosh that truly is writable, like the "/tmp/" directory?
You have not explained what your function SeeWorkingDir() does.
Maybe you should use wxFileName::GetTempDir to specify the directory where you store the file. This should be platform independent.
Or, in your call wxFileName::CreateTempFileName(curDir), you could specify the fileTemp parameter to open the file directly.
See the documentation:
wxWidgets 2.8.12 - wxFileName
I am working on figuring out how to use Xcode 4 to debug c++ projects.
I have basically copy pasted a working c++ executable that when compiled from the terminal ran fine.
However, i was thinking it might be nice to use Xcode for debugging. So I am trying to migrate the single .cpp file into Xcode as a command line tool.
I need to read in a file called numbers.txt (which I supply through a command line argument) which is located in my project directory, and then out put to a file (whose name I also specify as an argument.)
The problem I am running into is that the files that are supplied as command line arguments are failing to open.
ifstream in;
ofstream out;
in.open(argv[1]);
out.open(argv[2]);
I have checked to make sure that the arguments are being properly passed and are named correctly. The ifstream in is being supplied with `numbers.txt', which I want to open a text file that I already have.
However when I check to make sure the ifstream is open:
if(in.is_open() == false){
cerr << "Unable to open input file" << endl;
return 1;
}
I get the error.
I suspect this has something to do with how Xcode organizes the project.
my numbers.txt file is just sitting in the Xcode project folder, and I have only one .cpp class and one product, the executable.
anyone know what I am missing here?
The executable built by Xcode is in a different folder than the project. Passing in the name of the file without an absolute path before it will cause the executable to look for it in the wrong place, which is why it can't be found. Some of the possible solutions are to include the file as part of the build process (so it ends up in the same directory as the executable) or to pass the file to be opened by its absolute path. There are other ways to solve the problem, too, but hopefully that should be enough to get you started.
Old thread, but i have faced the same problem now, and it is easy to solve. Just copy the file in the build phase.
Here is an screenshot of the final result (note the destination, subpath and checkbox):