connect to hdfs as arbitrary user

[Petru Dimulescu]

Hello,

I would like to connect to hdfs as another user than my unix login. How 
can I do that?

I am most intersted how can I change the current user programmatically 
at DFSClient level; but if there are any command-line options i am 
interested too, I will take a look at the code that implements them.

Thanks
Petru