CODEWITHSUNDEEP
c++visual-studiofilebuffer
bodacydo
bodacydo

Reputation: 79539

How do I read the whole file in wchar_t buffer on Win32?

I'm having trouble reading a file in UTF8 encoding into a wchar_t buffer as I don't know the file size in advance.

Does anyone know how I can read the whole file in a buffer?

I imagine I'd have to keep a wchar_t * (pointer) and resize it as I read. However that sounds very scary as I haven't ever resized pointers before.

I'm doing Windows C++ programming with Microsoft Visual Studio.

Upvotes: 1

Views: 3090

Answers (2)

111111
111111

Reputation: 16168

Have you considered using a vector?

#include <vector>
#include <fstream>
#include <iterator>

:::

std::wifstream in(file_name);

//Will automatically reallocate to the require size
std::vector<wchar_t> store {
    std::istream_iterator<wchar_t, wchar_t>(in),
    std::istream_iterator<wchar_t, wchar_t>()};

//to access wchar_t* you can call data();
my_func(store.data());

Upvotes: 2

DRVic
DRVic

Reputation: 2491

If you want to allocate a buffer the size of the file you first need to find the file size. To do that, you call the stat() function, with appropriate arguments, and it fills in a field containing the file size.

Suppose you store that size in the variable filesize.

Then you can 

wchar_t *buffer = reinterpret_cast< wchar_t * >new char [ filesize ];

and then read the whole file into that buffer, using read(), after having called open() on it to get a file descriptor, or fread() after having called fopen() to get a FILE *.

Upvotes: -1

Related Questions