usvfs_del.c

#include <windows.h>
#include <stdio.h>

void PrintErr(LPCWSTR func)
{
    DWORD code = GetLastError();
    LPWSTR errorText;
    FormatMessageW(
        FORMAT_MESSAGE_FROM_SYSTEM
        | FORMAT_MESSAGE_ALLOCATE_BUFFER
        | FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        code,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
        (LPWSTR)&errorText,
        0,
        NULL);
    
    wprintf(L"%s failed (0x%X): %s", func, code, errorText);
}

int wmain(int argc, wchar_t** argv)
{
    if (argc >= 2)
    {
        // Final directory in the path (CustomRegionSaveData) exists only in MO2 VFS.
        if (!SetCurrentDirectoryW(L"D:\\steam_windows\\steamapps\\common\\Rain World\\UserData\\CustomRegionSaveData"))
        {
            PrintErr(L"SetCurrentDirectoryW");
            return 1;
        }
    }

    wchar_t curdir[300];
    GetCurrentDirectoryW(300, curdir);

    wprintf(L"Deleting foo.txt from %s\n", curdir);

    if (!DeleteFileW(L"foo.txt"))
    {
        PrintErr(L"DeleteFileW");
        return 1;
    }

    wprintf(L"Success!\n");
    return 0;
}