Pig already has this! :)
http://pig.apache.org/docs/r0.10.0/cont.html#parameter-sub
Unless I'm really misunderstanding what you mean?
2012/7/26 Haitao Yao <yao.e...@gmail.com>
> Hi, all
> I got an idea about a new feature for pig: define global constants
> in pig script.
> Here's the example like this:
>
> -- define a global constant for storage
> define store_location "/where_you_store_result";
>
> -- then all the following constants reference will be replaced in runtime
> store Result into $$store_location using PigStorage(',');
>
>
> so, in this way, we just write the template scripts and import
> them with the constants defined. A commonly use case is use it to compute
> data for different days.
> Without this feature, I have to use sed to replace the variables
> on the template script to generate the daily pig scripts.
> How do you guy think so?
>
>
> Haitao Yao
> yao.e...@gmail.com
> weibo: @haitao_yao
> Skype: haitao.yao.final
>
>
