@pra_big
hbase user is the admin user of hbase one connects to a running instance of HBase using the hbase shell command, located in the bin/ directory of your HBase install. Here the version information that is printed when you start HBase Shell has been omitted. The HBase Shell prompt ends with a > character.
As hbase user
$ ./bin/hbase shell
hbase(main):001:0>
All the below methods will give you access to the HBase shell as the admin user [hbase]
If you have root access
# su - hbase
It will give you the same above
If you have sudo privileges
# sudo su hbase -l
I don't see the reason for changing to bash or didn't I understand your question well?