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https://issues.apache.org/jira/browse/HBASE-11686?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17168088#comment-17168088
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Sean Busbey commented on HBASE-11686:
-------------------------------------

please update the release note to show an example of both "run this script for 
the shell" as well as "use an interactive shell"

> Shell code should create a binding / irb workspace instead of polluting the 
> root namespace
> ------------------------------------------------------------------------------------------
>
>                 Key: HBASE-11686
>                 URL: https://issues.apache.org/jira/browse/HBASE-11686
>             Project: HBase
>          Issue Type: Improvement
>          Components: shell
>            Reporter: Sean Busbey
>            Assignee: Elliot Miller
>            Priority: Minor
>             Fix For: 3.0.0-alpha-1
>
>
> Right now, the shell builds a list of commands and then injects them into the 
> root exectution's context
> bin/hirb.rb
> {code}
> # Add commands to this namespace
> @shell.export_commands(self)
> {code}
> hbase-shell/src/main/ruby/shell.rb
> {code}
>     def export_commands(where)
>       ::Shell.commands.keys.each do |cmd|
>         # here where is the IRB namespace
>         # this method just adds the call to the specified command
>         # which just references back to 'this' shell object
>         # a decently extensible way to add commands
>         where.send :instance_eval, <<-EOF
>           def #{cmd}(*args)
>             ret = @shell.command('#{cmd}', *args)
>             puts
>             return ret
>           end
>         EOF
>       end
>     end
> {code}
> This is an unclean abstraction. For one, it requires that there be an 
> instance variable in the main namespace called '@shell' without making that 
> clear in the docs. Additionally, it complicates maintenance by breaking 
> isolation.
> We should update things so that shell can provide a binding for eval or a 
> workspace for IRB execution and then use it directly when we construct our 
> IRB session.



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