Introduction to common command parameters:
-help: output this command parameter manual
[hadoop@hadoop02 ~]$ hadoop -help
[hadoop@hadoop02 ~]$ hadoop fs -help
[hadoop@hadoop02 ~]$ hadoop fs -help ls-ls: Display directory information
hadoop fs -ls hdfs://hadoop02:9000/Note: In these parameters, all hdfs paths can be abbreviated as hadoop fs -ls / equivalent to the effect of the previous command
-mkdir: create a directory on hdfs
hadoop fs -mkdir -p /aa/bb/cc/dd-put: equivalent to copyFromLocal, for file upload
hadoop fs -put /aaa/jdk.tar.gz /bbb/jdk.tar.gz.2-get: equivalent to copyToLocal, which is to download files from hdfs to local
hadoop fs -get /aaa/jdk.tar.gz-getmerge: merge and download multiple files
Example: There are multiple files under the directory /aaa/ of getmerge hdfs: log.1, log.2,log.3,...
hadoop fs -getmerge /aaa/log.* ./log.sum-cp: Copy another path of hdfs from one path of hdfs
hadoop fs -cp /aaa/jdk.tar.gz /bbb/jdk.tar.gz.2-mv: move files in the hdfs directory
hadoop fs -mv /aaa/jdk.tar.gz /-rm: delete files or folders
hadoop fs -rm -r /aaa/bbb/-rmdir: delete empty directories
hadoop fs -rmdir /aaa/bbb/ccc-moveFromLocal: cut from local to hdfs
hadoop fs - moveFromLocal /home/hadoop/a.txt /aa/bb/cc/dd-moveToLocal: cut from hdfs to local
hadoop fs - moveToLocal /aa/bb/cc/dd /home/hadoop/a.txt-copyFromLocal: copy files from the local file system to the hdfs file system
hadoop fs -copyFromLocal ./jdk.tar.gz /aaa/-copyToLocal: copy from hdfs to local
hadoop fs -copyToLocal /aaa/jdk.tar.gz-appendToFile: Append a file to the end of an existing file
hadoop fs -appendToFile ./hello.txt hdfs://hadoop-server01:9000/hello.txt
# 可以简写为：
hadoop fs -appendToFile ./hello.txt /hello.txt-cat: display file content
hadoop fs -cat /hello.txt-tail: display the end of a file
hadoop fs -tail /weblog/access_log.1-text: Print the content of a file in character form
hadoop fs -text /weblog/access_log.1-chgrp, -chmod, -chown: The usage in the linux file system is the same, and the file ownership permissions
hadoop fs -chmod 666 /hello.txt
hadoop fs -chown someuser:somegrp /hello.txt-df: Count the available space information of the file system
hadoop fs -df -h /-du: Statistics about the size of the folder
hadoop fs -du -s -h /aaa/*-count: count the number of file nodes in a specified directory
hadoop fs -count /aaa/-setrep: Set the number of copies of files in hdfs
hadoop fs -setrep 3 /aaa/jdk.tar.gzSupplement: The command to view the working status of the dfs cluster
hdfs dfsadmin -report