HDFS basic Commands

HDFs Common commands:
Note: The following execution commands are in the bin directory of the Spark installation directory.
Path src for file path dist to folder
1.-help[cmd] Show Help for commands

./hdfs Dfs-help ls

2.-ls (r) displays all files in the current directory-R layer-by-layer follow-up folder

./hdfs dfs-ls/log/map
./hdfs dfs-lsr/log/   (Recursive)

3,-du (s) displays all file sizes in the directory, or displays the size of this file when only one file is specified

./hdfs Dfs-du/user/hadoop/dir1/user/hadoop/file1 Hdfs://host:port/user/hadoop/dir1

4,-count[-q] Displays all file sizes in the current directory
5.-MV move multiple file directories to the target directory

./hdfs Dfs-mv/user/hadoop/file1/user/hadoop/file2

6.-CP copy multiple files to target directory

./hdfs dfs-cp/user/hadoop/file1/user/hadoop/file2 (Copy the file from the source path to the destination path.)
This command allows for multiple source paths, at which point the destination path must be a directory. )

7.-RM (r) Delete file (clip)

./hdfs dfs-rmr/log/map1  (recursive deletion)

8.-put local file copy to HDFs

./hdfs Dfs-put test.txt/log/map/

9.-copyfromlocal local file copy to HDFs

./hdfs dfs-copyfromlocal/usr/data/text.txt/log/map1/   (Copy the local text.txt to the/log/map1/of HDFs)

10.-movefromlocal local file moved to HDFs

./hdfs dfs-movefromlocal/usr/data/text.txt/log/map1/   (move the local text.txt to the/log/map1/of HDFs)

11,-GET[-IGNORECRC] Copy file to local, can ignore CRC check

./hdfs dfs-get/log/map1/*  . (Copy to local current directory)
/hdfs dfs-get/log/map1/*/usr/data (copy all files under the/log/map1/under HDFs to local/usr/data/)

12.-getmerge[addnl] Merges all the files in the source directory into a single file, accepts a source directory and a destination file as input, and connects all the files in the source directory to the local destination file. ADDNL is optional and is used to specify that a line break is added at the end of each file.

./hdfs dfs-getmerge/log/map1/*/usr/data (Download all files under/log/map1/on HDFs to local/usr/data)

13,-cat in the terminal display file content

./hdfs dfs-cat/log/map1/part-00000  | Head (reads the part-00000 file head parameter under/log/map1 on HDFs    , representing the first 10 rows. )

 /hdfs dfs-tail/log/map1/part-00000 (view the last 1000 lines of the file)

14,-text in the terminal display file content, the source file output as text format. The allowed formats are zip and Textrecordinputstream
15.-COPYTOLOCAL[-IGNORECRC] Copy files to local
16.-movetolocal move files to Local
17.-mkdir Create folder followed by-P to create a parent path that does not exist

./hdfs Dfs-mkdir-p/dir1/dir11/dir111  

18.-touchz Create an empty file

19.-grep Filtering the contents of a line containing a character from HDFs

./hdfs dfs-cat/log/testlog/* | grep filter Field