Validate Oracle dmp
You can run:
imp file=xxx.dmp show=Y full=y userid=user@dbThis will list the contents of the export file without actually doing any actual import operations. I would assume that if the import utility could make sense of the export file, then it's a valid export file.
EDIT:
"Validate" is a vague term. I have made the assumption that what you want is a tool to make sure the file can be imported at some point in the future. This should do that. If you're looking for something more, like a sanity or consistency check on the actual data, I know of nothing other than to do the export with CONSISTENT=Y, which will give you a read-consistent view of the data as of the time the export started.