Common commands on hadoop

I sorted it out by referring to a person's blog on the Internet:
Start HadoopGo to the HADOOP_HOME directory. Run bin/start-all.sh close Hadoop go to HADOOP_HOME directory execute bin/stop-all.sh

 

1. view the content in the specified directory

Hadoop dfs-ls [file directory]

Eg: hadoop dfs-ls/user/wangkai.pt

2. Open an existing file

Hadoop dfs-cat [file_path]

Eg: hadoop dfs-cat/user/wangkai.pt/data.txt

3. Store Local files to hadoop

Hadoop fs-put [local address] [hadoop Directory]

Hadoop fs-put/home/t/file.txt/user/t

(File.txt is the file name)

4. Store Local folders to hadoop

Hadoop fs-put [local directory] [hadoop Directory]
Hadoop fs-put/home/t/dir_name/user/t

(Dir_name is the folder name)

5. down a file on hadoop to a local directory

Hadoop fs-get [file directory] [local directory]

Hadoop fs-get/user/t/OK .txt/home/t

6. delete a specified file on hadoop

Hadoop fs-rm [file address]

Hadoop fs-rm/user/t/OK .txt

7. Delete specified folders (including subdirectories) on hadoop)

Hadoop fs-rm [directory address]

Hadoop fs-rmr/user/t

8. Create a new directory in the specified directory of hadoop

Hadoop fs-mkdir/user/t

9. Create an empty file under the specified directory of hadoop

Run the touchz command:

Hadoop fs-touchz/user/new.txt

10. rename a file on hadoop

Use the mv command:

Hadoop fs-mv/user/test.txt/user/OK .txt (rename test.txt as OK .txt)

11. Save all content in the specified hadoop directory as a file and go down to the local directory.

Hadoop dfs-getmerge/user/home/t

12. kill a running hadoop job.

Hadoop job-kill [job-id]

The log information during hadoop startup. In the log folder under the HADOOP_HOME directory, the NameNode and DataNode cannot be started. You can check the log information in the log.