We can execute hadoop commands in hive cli. It is very simple.
Just put an exclamation mark (!) before your hadoop command in hive cli and put a semicolon (;) after your command.

Example:

hive> !hadoop fs –ls / ;

drwxr-xr-x   - hdfs supergroup          0 2013-03-20 12:44 /app
drwxrwxrwx   - hdfs supergroup          0 2013-05-23 11:54 /tmp
drwxr-xr-x   - hdfs supergroup          0 2013-05-08 18:47 /user

Very simple.. 🙂