jar command

[Wang Yu <wa...@gmail.com>]

Hi,all
In the wiki of hadoop, I see the following command:
bin/hadoop jar hadoop-0.14.2-examples.jar wordcount gutenberg gutenberg-output

what is the meaning of the command jar?  And jar has no option like c or x, why?

Thanks!

-- 
National Research Center for Intelligent Computing Systems
Institute of Computing Technology, Chinese Academy of Sciences

Re: jar command

[Adrian Woodhead <ad...@last.fm>]

The purpose is to tell hadoop which jar file to look inside of to find 
the launcher class for starting the named map/reduce program (in this 
example "wordcount"). So it is not like the standard jar command for 
creating and extracting files, but is rather an argument passed to the 
hadoop command.

Wang Yu wrote:
> Hi,all
> In the wiki of hadoop, I see the following command:
> bin/hadoop jar hadoop-0.14.2-examples.jar wordcount gutenberg gutenberg-output
>
> what is the meaning of the command jar?  And jar has no option like c or x, why?
>
> Thanks!
>
>