ReadFile/WriteFile crahes - winapi

Question

Something wrong with next ReadFile/WriteFile code.
I need to use copy file by using this functions (yes, it's better to use CopyFile, but now I need it), but it crashed at read/write loop.
What can be wrong?
PS C:\Users\user\Documents\SysLab1\dist\Debug\MinGW-Windows> g++ --version
g++.exe (x86_64-posix-sjlj-rev0, Built by MinGW-W64 project) 4.8.3
I used next code :
#include <windows.h>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#define BLOCK_SIZE 1024
uint32_t copy_c(char* source, char* destination) {...}
uint32_t copy_api_readwrite(char* source, char* destination) {
bool result;
HANDLE input = CreateFile(source, GENERIC_READ, 0, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (input!=INVALID_HANDLE_VALUE) {
HANDLE output = CreateFile(destination, GENERIC_WRITE, 0, NULL,
CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
if(output!=INVALID_HANDLE_VALUE) {
DWORD readed;
char block[BLOCK_SIZE];
while(ReadFile(input, block, BLOCK_SIZE * sizeof(char), &readed, NULL)>0) {
WriteFile(output, block, readed, NULL, NULL);
}
if(GetLastError()==ERROR_HANDLE_EOF) {
result = true;
}
else {
result = false;
}
CloseHandle(output);
}
else {
result = false;
}
CloseHandle(input);
}
else {
result = true;
}
if(result) {
return 0;
}
else {
return GetLastError();
}
return result;
}
uint32_t copy_api(char* source, char* destination) {...}
#define COPY_READWRITE
#ifdef COPY_C
#define COPY copy_c
#else
#ifdef COPY_READWRITE
#define COPY copy_api_readwrite
#else
#ifdef COPY_API
#define COPY copy_api
#endif
#endif
#endif
int main(int argc, char** argv) {
if(argc<3) {
std::cout << "Bad command line arguments\n";
return 1;
}
uint32_t result = COPY(argv[1], argv[2]);
if(result==0) {
std::cout << "Success\n";
return 0;
}
else {
std::cout << "Error : " << result << "\n";
return 2;
}
}

Answer 1

From the documentation of WriteFile:
lpNumberOfBytesWritten
This parameter can be NULL only when the lpOverlapped parameter is not NULL.
You are not meeting that requirement. You will have to pass the address of a DWORD variable into which the number of bytes written will be stored.
Another mistake is in the test of the return value of ReadFile. Instead of testing ReadFile(...) > 0 you must test ReadFile(...) != 0, again as described in the documentation.
You don't check the return value of WriteFile which I also would regard as a mistake.
By definition, sizeof(char) == 1. It is idiomatic to make use of that.
When dealing with binary data, as you are, again it is idiomatic to use unsigned char.
More idiom. Write the assignment of result like this:
result = (GetLastError() == ERROR_HANDLE_EOF);