how to check database version in oracle

You can use adident after setting APPS<SID>.env variable in ERP R12 or 11i

adident Header <file name>

Example :

You can give the whole directory path and run this as
[oracle@test server]$ adident Header $JAVA_TOP/oracle/apps/pos/supplier/webui/ByrMngSitesCO.class

$Header ByrMngSitesCO.java 120.22.12010000.8 2009/11/20 19:13:22 atjen ship $

or goto $JAVA_TOP/oracle/apps/pos/supplier/webui directory and type

[oracle@test server]$ cd $JAVA_TOP/oracle/apps/pos/supplier/webui
[oracle@test webui]$ adident Header ByrMngSitesCO.class
ByrMngSitesCO.class:
$Header ByrMngSitesCO.java 120.22.12010000.8 2009/11/20 19:13:22 atjen ship $

The alternate Linux command strings -a and it will return the same result for you

strings -a ByrMngSitesCO.class | grep '$Header'

N$Header: ByrMngSitesCO.java 120.22.12010000.8 2009/11/20 19:13:22 atjen ship $

I hope this helps you understand these two important commands

Thanks in advance,