wide narrow output of command using windows api in c

#include <io.h>
#include <fcntl.h>
#include <windows.h>
#include <stdio.h>
#include <wchar.h>
#include <unistd.h>
 
 
typedef struct Result
{
    char * ptr;
    size_t len;
} Result;
 
 
HANDLE C_IN_R = NULL;
HANDLE C_IN_W = NULL;
HANDLE C_OUT_R = NULL;
HANDLE C_OUT_W = NULL;
HANDLE handle = NULL;
 
// callback
DWORD WINAPI read_output(void * ptr )
{
    BOOL success = FALSE;
    DWORD dwRead, total =0;
 
    Result * out = (Result*)ptr;
    while(1)
    {
        char buffer[64] = {0};
        success = ReadFile(C_OUT_R, buffer, 64, &dwRead, NULL);
        if (!success)
        {
            out->ptr[total] = '\0';
            break;
        }
        out->ptr = realloc(out->ptr, total+64);
        memcpy(out->ptr+total, buffer, dwRead);
        total += dwRead;
        out->len = total;
    }
    return GetLastError();
}
 
int run(wchar_t * cmd)
{
    wchar_t buffer[8192] = {0};
    STARTUPINFOW si;
    PROCESS_INFORMATION pi;
    SECURITY_ATTRIBUTES sa;
    memset(&si, 0, sizeof(STARTUPINFOW));
    memset(&pi, 0, sizeof(PROCESS_INFORMATION));
    memset(&sa, 0, sizeof(SECURITY_ATTRIBUTES));
    sa.nLength = sizeof(SECURITY_ATTRIBUTES);
    sa.bInheritHandle = TRUE;
    sa.lpSecurityDescriptor = NULL;
    wcscat(buffer, L"C:\\windows\\System32\\cmd.exe /u /c ");
    wcscat(buffer, cmd);
    if (!CreatePipe(&C_OUT_R, &C_OUT_W, &sa, 0))
        return GetLastError();
 
    if (!SetHandleInformation(C_OUT_R, HANDLE_FLAG_INHERIT, 0))
        return GetLastError();
 
    si.cb = sizeof(STARTUPINFOW);
    si.hStdOutput = C_OUT_W;
    si.hStdError = C_OUT_W;
    si.dwFlags |= STARTF_USESTDHANDLES;
 
    if (!CreateProcessW(NULL, buffer, NULL,NULL,TRUE,CREATE_NO_WINDOW, NULL,NULL, &si,&pi))
        return GetLastError();
    else
    {
        Result out;
        memset(&out, 0, sizeof(Result));
        handle = CreateThread(0,0, read_output, &out,0,NULL);
        WaitForSingleObject(pi.hThread, INFINITE);
        wprintf(L"%S %ld",out.ptr, out.len);
    }
    return 0;
}
 
int main()
{
    _setmode(fileno(stdout), _O_U8TEXT);
    run(L"dir /b");
    wprintf(L"---------------------------\n");
    run(L"ipconfig");
    return 0; 
}