"Hadoop" HDFs basic command

1.Create directory
[grid @ master ~] $ hadoop fs -mkdir / test
2. View the file list
[grid @ master ~] $ hadoop fs -ls /
Found 3 items
drwxr-xr-x-grid supergroup 0 2018-01-08 04:37 / test
drwx -------grid supergroup 0 2018-01-07 11:57 / tmp
drwxr-xr-x-grid supergroup 0 2018-01-07 11:46 / user
3. Upload files to HDFS
#New upload directory
[grid @ master ~] $ hadoop fs -mkdir / test / input
#Upload files to the new directory, two commands can upload
(1) hadoop fs -put

[grid @ master ~] $ hadoop fs -put /home/grid/grid.txt /test/input/grid.txt
[grid @ master ~] $ hadoop fs -ls / test / input
Found 1 items
-rw-r--r-- 2 grid supergroup 0 2018-01-08 04:43 /test/input/grid.txt
(2) hadoop fs -copyFromLocal

[grid @ master ~] $ hadoop fs -copyFromLocal -f /home/grid/grid.txt /test/input/grid1.txt

[grid @ master ~] $ hadoop fs -ls / test / input
Found 2 items
-rw-r--r-- 2 grid supergroup 0 2018-01-08 04:43 /test/input/grid.txt
-rw-r--r-- 2 grid supergroup 0 2018-01-08 04:46 /test/input/grid1.txt
4. Download the file locally, two commands
(1) hadoop fs -get

[grid @ master ~] $ hadoop fs -get /test/input/grid.txt /home/grid/grid_local.txt
(2) hadoop fs -copyToLocal

[grid @ master ~] $ hadoop fs -copyToLocal /test/input/grid.txt /home/grid/grid_local_1.txt
5. View HDFS file contents, three commands
(1) hadoop fs -cat

[grid @ master ~] $ hadoop fs -cat /test/input/grid.txt
Welcome to my blog!
I'm NextAction!
(2) hadoop fs -tail

[grid @ master ~] $ hadoop fs -tail /test/input/grid.txt
Welcome to my blog!
I'm NextAction!
(3) hadoop fs -text

[grid @ master ~] $ hadoop fs -text /test/input/grid.txt
Welcome to my blog!
I'm NextAction!
6. Delete HDFS files
[grid @ master ~] $ hadoop fs -rm /test/input/grid.txt
18/01/08 04:58:13 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 0 minutes, Emptier interval = 0 minutes.