Check ORACLE DataPump Dump Version without log file
LINUX or UNIX
strings
$ strings Test.dmp|head -n 10
......
"BACKUP"."SYS_EXPORT_SCHEMA_15"
IBM AIX64/RS6000 V4 - 8.1.0 <-----------------os bit="" p="">ORACLECAIX02:orcl1<-----------------hostname :="" instance_name="" p="">WE8MSWIN1252 <---------------------- p="">11.02.00.04.00 <===== dump file version
001:001:000001:000001