HDFS commands for production environment

Q1)To check size of HDFS directory?
Ans: hdfs dfs -count -v -q -h /user/hive/warehouse/test.db/

Q2)To check if file exist or Not:
Ans:
hdfs dfs -test -e /user/hello/test.txt
echo $? =
{
If file exist
0
else
1
}

Q3)To check if file size is zero or not?
Ans:
hdfs dfs -test -z /user/hello/test.txt
echo $? =
{
If file size =0
0
else
1
}

Q4)To set replication factor of a hdfs file?
Ans:
For File:
hdfs dfs -setrep -w 4 /user/hello/test.txt
For Directory: (it will impact to each file inside directory & not to directory.)
hdfs dfs -setrep -w 1 -R /user/hello/testdir

Q5) To delete file from HDFS Trash folder?
Ans:
hdfs dfs -expunge

Q6)To delete file command to by pass Trash folder?
Ans:
For File:(Move to .Trash folder)
hdfs dfs -rm /user/hello/test.txt
For Directory:(Move to .Trash folder)
hdfs dfs -rm -R /user/hello/testdir
For File:(-skipTrash For permanent delete)
hdfs dfs -rm -skipTrash /user/hello/test.txt
For Directory:(-skipTrash For permanent delete)
hdfs dfs -rm -R -skipTrash /user/hello/testdir