test
Performs a file test.
The usage is as follows:
$ hadoop fs -test -[defswrz] URI| -d | If the path is a directory, returns  | 
| -e | If the path exists, returns  | 
| -f | If the path is a file, returns  | 
| -s | If the path is not empty, returns  | 
| -s | If the path exists and write permission is granted, returns  | 
| -r | If the path exists and read permission is granted, returns  | 
| -z | If the file is zero length, returns  | 
Example:
$ hadoop fs -test -e filename