Trying to open a file in C++, but the file cannot be found - clion

Question

I have an algorithm in C++ (main.cpp) and I use CLion to compile and run it. Algorithm would read strings from text file, but there is a mistake:
Could not open data.txt (file exists and placed in one folder with main.cpp)
How can I fix it and make this file "visible" to CLion?

Answer 1

If you are using fopen or something similar and just passing "data.txt", it is assumed that that file is in the current working directory of the running program (the one you just compiled).
So, either
Give a full path instead, like fopen("/full/path/to/data.txt"), where you use the actual full path
(not preferable), Move data.txt to the directory where CLion runs its compiled programs from.
(for #2, here's a hacky way to get that directory)
char buf[1024]; // hack, but fine for this
printf("%s\n", getcwd(buf, 1024));

Answer 2

Run/Edit configurations...
Select your application (on the lefthandside of the window)
Specify Working directory
Apply
Now you can fopen relatively from working directory.

Answer 3

I found another way to solve this problem.
#Lou Franco's solution may affect the project structure. For example, if I deploy code on a server, I should move the resource file to specific directory.
What I do is modify the CmakeLists.txt, on Windows, using
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "D:\\science\\code\\English-Prediction")
CMAKE_RUNTIME_OUTPUT_DIRECTORY is a CMake variable, it assigns the work directory of CLion work directory.

Answer 4

Continuing with the CMAKE_RUNTIME_OUTPUT_DIRECTORY CMakeLists variables, I do the following. In the root directory of my project, I create a directory, e.g., out. Then, in my CMakeLists.txt I set the CMAKE_RUNTIME_OUTPUT_DIRECTORY to that directory:
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_SOURCE_DIR}/out)
Note, that must come before you have
add_executable(YourProject ${SOURCE_FILES})
I might also add that instead of using fopen() I would keep it more object-oriented by using std::ifstream:
std::ifstream inFile("data.txt");
// check if it opened without issue...
if (!inFile) {
processError(); // a user-defined function to deal with the issue
} else {
// All is good, carry on...
// and when you're done don't forget
inFile.close();
}