How to copy multiple files with CopyFile function? - c

Question

Here is an example my code to copy file from src to dst:
int main() {
const wchar_t* file[3] = { L"\\abc.txt", L"\\def.txt", L"\\ghi.txt" };
for (int i = 0; i < 3; i++) {
wchar_t* src = funcA();
wchar_t* dst = funcB();
wcscat(dst, file[i]);
wcscat(src, file[i]);
CopyFileW(src, dst, TRUE);
}
}
Is there a better way to do that? Can I optimize the code by not running the funcA and funcB many times?

Answer 1

After you fix the errors, your code is copying the file to itself. It boils down to this:
const wchar_t* file[3] = { L"\\abc.txt", L"\\def.txt", L"\\ghi.txt" };
for(int i = 0; i < _countof(file); i++)
CopyFile(file[i], file[i], TRUE);
It's just copying "\\abc.txt" to "\\abc.txt", and "\\def.txt" to "\\def.txt", etc.
Presumably your intention is to copy multiple files from one directory to another directory. For example copy "abc.txt" to "c:\\target\\abc.txt", etc.
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
int main(void)
{
const wchar_t* files[3] = { L"1.txt", L"2.txt", L"3.txt" };
wchar_t *directory = L"c:\\target";
wchar_t dst[MAX_PATH] = { 0 };
for(int i = 0; i < _countof(files); i++)
{
swprintf(dst, _countof(dst), L"%ls\\%ls", directory, files[i]);
CopyFileW(files[i], dst, TRUE);
}
return 0;
}
Note that I changed the source to "abc.txt" and changed the format specifier in swprintf
In a practical application you may want to copy "c:\\src\\1.txt" to "c:\\dst\\1.txt", like this code:
#define UNICODE
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <Shlwapi.h>
#pragma comment(lib, "Shlwapi.lib")//Add library (Visual Studio specific)
int main(void)
{
const wchar_t* files[3] =
{ L"c:\\src\\1.txt", L"c:\\src\\2.txt", L"c:\\src\\3.txt" };
wchar_t *directory = L"c:\\dst";
wchar_t dst[MAX_PATH] = { 0 };
if(!PathFileExists(directory))
{
wprintf(L"path error\n");
return 0;
}
for(int i = 0; i < _countof(files); i++)
{
swprintf(dst, _countof(dst), L"%ls\\%ls", directory, PathFindFileName(files[i]));
//CopyFile(files[i], dst, TRUE);
wprintf(L"copy %s to %s\n", files[i], dst);
}
return 0;
}