Spotlight Indexing Status Questions as to Specific Folders

1. When using Terminal to reindex certain folders, is there a way to monitor and see reindexing progress?

2. When receiving the message ‘unknown indexing state,’ is there a way to find out what’ happening and if so, how?

3. When using Terminal to reindex, is there a way to get a text notification when the process is complete and if so, how?

Thank you!