If you are developing this feature within an application, follow this general logic: : Identify if a file ends in .001 .
: Use the 7-Zip SDK or LZMA SDK to handle the underlying decompression.
: Alert the user if any numbered parts in the sequence are missing.
: The system must automatically scan the local directory for subsequent parts (e.g., .7z.002 , .7z.003 ).
: If only the .001 file exists, the archive is incomplete and cannot be opened.