fstream Checking if file exists c++ - c++

Question

Hi guys I am working on an rpg project and I am creating player files so they can save their progress and such.
I've made a test program so I can show you on a more simple scale of what I am looking for
Code:
#include <iostream>
#include <fstream>
#include <string>
int main(){
std::string PlayerFileName;
std::cout << "Name Your Player File Name: ";
std::cin >> PlayerFileName;
std::ofstream outputFile;
std::string FileName = "Players/" + PlayerFileName;
outputFile.open(FileName); // This creates the file
// ...
}
I want to check and see if the Player File Name already exists the the Players directory so people cant save over their progress.
Thanks!

Answer 1

I suggest opening the file in binary mode and using seekg() and tellg() to count it's size. If the size is bigger than 0 bytes this means that the file has been opened before and has data written in it:
void checkFile()
{
long checkBytes;
myFile.open(fileName, ios::in | ios::out | ios::binary);
if (!myFile)
{
cout << "\n Error opening file.";
exit(1);
}
myFile.seekg(0, ios::end); // put pointer at end of file
checkBytes = myFile.tellg(); // get file size in bytes, store it in variable "checkBytes";
if (checkBytes > 0) // if file size is bigger than 0 bytes
{
cout << "\n File already exists and has data written in it;
myFile.close();
}
else
{
myFile.seekg(0. ios::beg); // put pointer back at beginning
// write your code here
}
}

Answer 2

Check if file exists like this:
inline bool exists (const std::string& filename) {
struct stat buffer;
return (stat (filename.c_str(), &buffer) == 0);
}
Using this needs to remember to #include <sys/stat.h>.
-
In C++14 it is possible to use this:
#include <experimental/filesystem>
bool exist = std::experimental::filesystem::exists(filename);
& in C++17: (reference)
#include <filesystem>
bool exist = std::filesystem::exists(filename);