A new utility oraversion has been introduced in Oracle 18c, Which provides Oracle database version/release related information.

HELP:

oraversion -help
This program prints release version information.
These are its possible arguments:
-compositeVersion: Print the full version number: a.b.c.d.e.
-baseVersion: Print the base version number: a.0.0.0.0.
-majorVersion: Print the major version number: a.
-buildStamp: Print the date/time associated with the build.
-buildDescription: Print a description of the build.
-help: Print this message.

For displaying specific information.

$ oraversion -compositeVersion
18.3.0.0.0

$ oraversion -baseVersion
18.0.0.0.0

$ oraversion -majorVersion
18

$ oraversion -buildStamp
180628094320

$ oraversion -buildDescription
Release_Update