C++ Get all bytes of a file in to a char array?

Question

Given:

const string inputFile = \"C:\\MyFile.csv\";
char buffer[10000];

How do I read the chars of the file in to the above buffer? I have

Answer 1

Another option would be to use a std::vector for the buffer, then use a std::istreambuf_iterator to read from an std::ifstream directly into the std::vector, eg:

const std::string inputFile = "C:\\MyFile.csv";
std::ifstream infile(inputFile, std::ios_base::binary);

std::vector buffer( std::istreambuf_iterator(infile),
                          std::istreambuf_iterator() );

Alternatively:

const std::string inputFile = "C:\\MyFile.csv";
std::ifstream inFile(inputFile, std::ios_base::binary);

inFile.seekg(0, std::ios_base::end);
size_t length = inFile.tellg();
inFile.seekg(0, std::ios_base::beg);

std::vector buffer;
buffer.reserve(length);
std::copy( std::istreambuf_iterator(inFile),
           std::istreambuf_iterator(),
           std::back_inserter(buffer) );

If you go with @user4581301's solution, I would still suggest using std::vector for the buffer, at least:

//open file
std::ifstream infile("C:\\MyFile.csv");
std::vector buffer;

//get length of file
infile.seekg(0, infile.end);
size_t length = infile.tellg();
infile.seekg(0, infile.beg);

//read file
if (length > 0) {
    buffer.resize(length);    
    infile.read(&buffer[0], length);
}