Function count_files_with_progress 

pub fn count_files_with_progress<F>(path: &Path, on_progress: F) -> u64
where
    F: Fn(u64),

Count files in a directory with progress callback.

The callback is invoked every 100 files with the current count. This allows updating a progress display during enumeration of large directories.

• If path is a file: returns 1
• If path is a directory: returns count of all files recursively
• If path doesn’t exist or is a symlink: returns 0

Arguments

• path - Path to count files in
• on_progress - Callback invoked every 100 files with current count

Returns

Total file count