Question

I’m trying to write a program that will delete a set of files/folders that are matching a specific naming pattern (wild cards) based on their dates using the windows API

...

    SHFILEOPSTRUCT shFileOpStruct = {
            .hwnd   = NULL,
            .wFunc  = processByDate->op,
            .pTo    = NULL,
            .fFlags = FOF_NOCONFIRMATION | FOF_SILENT
    };

    buildReferenceDate( &refTime, processByDate->nDays );
    hFind = FindFirstFile( processByDate->srcFileName, &findFileData );
    errorCode = GetLastError();

    while ( errorCode == ERROR_SUCCESS ) {
        LONG res = CompareFileTime( &refTime, &findFileData.ftCreationTime );

        if ( (processByDate->nDays ^ res) > 0 ) {
            sprintf( strrchr(processByDate->srcFileName, '\\') + 1, "%s%c",
                                             findFileData.cFileName, '\0');
            shFileOpStruct.pFrom = processByDate->srcFileName;
            fprintf( stdout, "\n%s\n", shFileOpStruct.pFrom);
            fprintf( stdout, "\n0x%x\n", SHFileOperation( &shFileOpStruct ));
        }
        FindNextFile( hFind, &findFileData );
        errorCode = GetLastError();
    }

    if ( errorCode != ERROR_NO_MORE_FILES )
        displayError ( stdout, errorCode );

...    

Only the first matching file is deleted, because FindNextFile terminates with “The handle is invalid.” apparently SHFileOperation somehow invalidates the file handle (or at least so I suppose). The only solution I can think of is to save the name of the matching files/folders and delete them one by one. Is there any other simpler solution?

Thanks

Answer 1

The thread’s last error code is not set when a function succeeds. Instead of calling GetLastError, you have to check the return value of FindNextFile.

If the function succeeds, the return value is nonzero and the lpFindFileData parameter contains information about the next file or directory found.

If the function fails, the return value is zero and the contents of lpFindFileData are indeterminate.

FindNextFile function

The loop should look like this:

HANDLE handle(FindFirstFile(...));
if (handle != INVALID_HANDLE_VALUE)
{
    do
    {
        // filter files here
    }
    while (FindNextFile(handle, ...));
    FindClose(handle);
}