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C++17 File Open
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// Requires at least C++17 | |
#include <filesystem> | |
#include <fstream> | |
#include <iostream> | |
#include <string> | |
int main() { | |
// Path is relative to executable. | |
std::filesystem::path filePath = "./out.txt"; | |
if (std::filesystem::exists(filePath)) { | |
std::cout << "File already exists!" << std::endl; | |
std::ifstream inFile; | |
inFile.open(filePath); | |
if (inFile.is_open()) { | |
std::cout << "Here are the contents of the file:" << std::endl; | |
for (std::string buffer; std::getline(inFile, buffer); std::cout << buffer); | |
} else { | |
std::cerr << "Unable to open file!\n"; | |
return 1; | |
} | |
} else { | |
std::cout << "File does not exist!\nCreating it now..." << std::endl; | |
std::ofstream outFile; | |
outFile.open(filePath, std::ios::trunc); | |
if (outFile.is_open()) { | |
outFile << "Hello, World!" << std::endl; | |
} else { | |
std::cerr << "Unable to open file!\n"; | |
return 1; | |
} | |
outFile.close(); | |
std::cout << "Wrote to file." << std::endl; | |
} | |
return 0; | |
} |
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