Problem with working with utf-8 text file c++ - c++

Question

lately I approach a problem when trying to get line from file that is utf-8(?) formatted. I also need to copy that string to clipboard and be able to paste it in .txt file.
#include <iostream>
#include <windows.h>
#include <cstdio>
#include <conio.h>
#include <time.h>
#include <string>
#include <fstream>
#include <wchar.h>
using namespace std;
wstring lastLine;
void mesparse()
{
wifstream client("Client.txt");
if(client.is_open())
{
client.seekg(-7,ios_base::end);
int kloop=0;
while (kloop<1)
{
wchar_t ch;
client.get(ch);
if(ch == '\n') {
kloop=1;
}
else {
client.seekg(-4,ios_base::cur);
}}
getline(client,lastLine);
client.close();
}
else
{
cout<<"Unable to open client.txt file.";
}
}
void toClipboard(std::wstring s){
const wchar_t* text = s.c_str();
int len = wcslen(text);
HGLOBAL hMem = GlobalAlloc(GMEM_MOVEABLE, (len + 1) * sizeof(wchar_t));
wchar_t* buffer = (wchar_t*)GlobalLock(hMem);
wcscpy_s(buffer, len + 1, text);
GlobalUnlock(hMem);
OpenClipboard(NULL);
EmptyClipboard();
SetClipboardData(CF_UNICODETEXT, hMem);
CloseClipboard();
}
int main()
{
mesparse();
toClipboard(lastLine);
wcout<<lastLine<<endl;
}
What I'm trying to copy:
йцукaеёśнгшщㅂхфывапрㅊджэячсмитъбюㅗ
йцукaеёśнгшщㅂхфывапрㅊджэя
йцукaеёśнгшщㅂхфывапрㅊ
йцукaеёśнгшщㅂхфыва

Answer 1

CF_UNICODETEXT != UTF-8.
The first is wide chars, the second is 8 bit.
You first have to convert it with MultiByteToWideChar().
Therefore, read all the text to std::string, not to std::wstring. Then get the std::wstring with MultiByteToWideChar() and then copy it to clipboard.
Also, doing character search in UTF-8 text is usually a bad idea (variable encoding).

Answer 2

This is an example code of solution pointed out by #Michael Chourdakis.
string mesparse()
{
string lastLine = "";
ifstream client("Client.txt");
if (client.is_open())
{
client.seekg(-7, ios_base::end);
int kloop = 0;
while (kloop < 1)
{
char ch;
client.get(ch);
if (ch == '\n') {
kloop = 1;
}
else {
client.seekg(-4, ios_base::cur);
}
}
getline(client, lastLine);
client.close();
}
else
{
cout << "Unable to open client.txt file.";
}
return lastLine;
}
void toClipboard(std::string s) {
int len;
// Retrieve the length
len = MultiByteToWideChar(CP_UTF8, MB_PRECOMPOSED, s.c_str(), -1, NULL, 0);
HGLOBAL hMem = GlobalAlloc(GMEM_MOVEABLE, (len) * sizeof(wchar_t));
wchar_t* buffer = (wchar_t*)GlobalLock(hMem);
// Convert to wide char string
len = MultiByteToWideChar(CP_UTF8, MB_PRECOMPOSED, s.c_str(), -1, buffer, len);
GlobalUnlock(hMem);
wcout << buffer << endl;
OpenClipboard(NULL);
EmptyClipboard();
SetClipboardData(CF_UNICODETEXT, hMem);
CloseClipboard();
}
int main()
{
string copiedStr = mesparse();
if (copiedStr.length() == 0)
return 0;
toClipboard(copiedStr);
}