Karaf Shell Scripting Caveats - Part I

Karaf Shell Scripting is an incredibly powerful tool - it makes the Karaf platform even more of a very portable operating system riding over the Java Virtual Machine

But I'm learning the pitfalls of upgrading and it impacts shell scripting as well. I recently upgraded from Karaf 4.0.9 to Karaf 4.1.5 and a possibly rash dependence on shell:tac behavior, broke some very critical scripts.

I had created scripts in Karaf 4.0.9 to parse the output of a jdbc:query as follows:

jdbc:query localhost.information_schema "select schema_name from schemata"
The response on screen looks like this:
schema_name
------------------
information_schema
123homeloans
aark_digital
arihant_bak
mysql
performance_schema
sys

I used to parse the output with the following code:
dbList = (jdbc:query $hostName\.information_schema "select schema_name from schemata"  |  tac) ;
each ($dbList split "\n") {echo $it}  

I depended on newlines being inserted by tac. This is no longer the case in Karaf 4.1.5 - you only have spaces between the records

There is also some minor but significant changes in the behavior of scripting around closures - see the following link for a discussion on this: KARAF-5613