You can use the “hadoop fs -ls command”.
This command displays the list of files in the current directory and all it’s details.In the output of this command, the 5th column displays the size of file in bytes.
For e.g.
command hadoop fs -ls
input gives following output:
Found 1 items
-rw-r--r-- 1 hduser supergroup 36789 2012-07-19 20:57 /user/hduser/input/shivangi
The size of file shivangi is 36789 bytes.