HDFS的Shell操作

1、 基本语法

bin/hadoop fs 具体命令   或者   bin/hdfs dfs 具体命令

2、 命令大全

[atguigu@hadoop102 hadoop-3.1.3]$ bin/hadoop fs

Usage: hadoop fs [generic options]
	[-appendToFile  ... ]
	[-cat [-ignoreCrc]  ...]
	[-checksum  ...]
	[-chgrp [-R] GROUP PATH...]
	[-chmod [-R]  PATH...]
	[-chown [-R] [OWNER][:[GROUP]] PATH...]
	[-copyFromLocal [-f] [-p] [-l] [-d] [-t ]  ... ]
	[-copyToLocal [-f] [-p] [-ignoreCrc] [-crc]  ... ]
	[-count [-q] [-h] [-v] [-t []] [-u] [-x] [-e]  ...]
	[-cp [-f] [-p | -p[topax]] [-d]  ... ]
	[-createSnapshot  []]
	[-deleteSnapshot  ]
	[-df [-h] [ ...]]
	[-du [-s] [-h] [-v] [-x]  ...]
	[-expunge]
	[-find  ...  ...]
	[-get [-f] [-p] [-ignoreCrc] [-crc]  ... ]
	[-getfacl [-R] ]
	[-getfattr [-R] {-n name | -d} [-e en] ]
	[-getmerge [-nl] [-skip-empty-file]  ]
	[-head ]
	[-help [cmd ...]]
	[-ls [-C] [-d] [-h] [-q] [-R] [-t] [-S] [-r] [-u] [-e] [ ...]]
	[-mkdir [-p]  ...]
	[-moveFromLocal  ... ]
	[-moveToLocal  ]
	[-mv  ... ]
	[-put [-f] [-p] [-l] [-d]  ... ]
	[-renameSnapshot   ]
	[-rm [-f] [-r|-R] [-skipTrash] [-safely]  ...]
	[-rmdir [--ignore-fail-on-non-empty]  ...]
	[-setfacl [-R] [{-b|-k} {-m|-x } ]|[--set  ]]
	[-setfattr {-n name [-v value] | -x name} ]
	[-setrep [-R] [-w]   ...]
	[-stat [format]  ...]
	[-tail [-f] [-s ] ]
	[-test -[defsz] ]
	[-text [-ignoreCrc]  ...]
	[-touch [-a] [-m] [-t TIMESTAMP ] [-c]  ...]
	[-touchz  ...]
	[-truncate [-w]   ...]
	[-usage [cmd ...]]

Generic options supported are:
-conf         specify an application configuration file
-D                define a value for a given property
-fs  specify default filesystem URL to use, overrides 'fs.defaultFS' property from configurations.
-jt   specify a ResourceManager
-files                 specify a comma-separated list of files to be copied to the map reduce cluster
-libjars                specify a comma-separated list of jar files to be included in the classpath
-archives           specify a comma-separated list of archives to be unarchived on the compute machines

The general command line syntax is:
command [genericOptions] [commandOptions]

3、 常用命令实操

3.1 准备工作

1）启动Hadoop集群（方便后续的测试）

[Mark@hadoop102 hadoop-3.1.3]$ sbin/start-dfs.sh
[Mark@hadoop103 hadoop-3.1.3]$ sbin/start-yarn.sh

2）-help：输出这个命令参数

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -help rm

3.2 上传

1）-moveFromLocal：从本地剪切粘贴到HDFS

[Mark@hadoop102 hadoop-3.1.3]$ touch kongming.txt

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs  -moveFromLocal  ./aa.txt  /aa/bb

2）-copyFromLocal：从本地文件系统中拷贝文件到HDFS路径去

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -copyFromLocal README.txt /

3）-appendToFile：追加一个文件到已经存在的文件末尾

[Mark@hadoop102 hadoop-3.1.3]$ touch liubei.txt
[Mark@hadoop102 hadoop-3.1.3]$ vi liubei.txt

输入
san gu mao lu

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -appendToFile liubei.txt /sanguo/shuguo/kongming.txt

4）-put：等同于copyFromLocal

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -put ./zaiyiqi.txt /user/atguigu/test/

3.3、下载

1）-copyToLocal：从HDFS拷贝到本地

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -copyToLocal /sanguo/shuguo/kongming.txt ./

2）-get：等同于copyToLocal，就是从HDFS下载文件到本地

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -get /sanguo/shuguo/kongming.txt ./

3）-getmerge：合并下载多个文件，比如HDFS的目录 /user/atguigu/test下有多个文件:log.1, log.2,log.3,...

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -getmerge /user/atguigu/test/* ./zaiyiqi.txt

3.4、 HDFS直接操作

1）-ls: 显示目录信息

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -ls /

2）-mkdir：在HDFS上创建目录

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -mkdir -p /sanguo/shuguo

3）-cat：显示文件内容

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -cat /sanguo/shuguo/kongming.txt

4）-chgrp 、-chmod、-chown：Linux文件系统中的用法一样，修改文件所属权限

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs  -chmod  666  /sanguo/shuguo/kongming.txt
[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs  -chown  atguigu:atguigu   /sanguo/shuguo/kongming.txt

5）-cp ：从HDFS的一个路径拷贝到HDFS的另一个路径

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -cp /sanguo/shuguo/kongming.txt /zhuge.txt

6）-mv：在HDFS目录中移动文件

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -mv /zhuge.txt /sanguo/shuguo/

7）-tail：显示一个文件的末尾

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -tail /sanguo/shuguo/kongming.txt

8）-rm：删除文件或文件夹

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -rm /user/atguigu/test/jinlian2.txt

9）-rmdir：删除空目录

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -mkdir /test
[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -rmdir /test

10）-du统计文件夹的大小信息

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -du -s -h /user/atguigu/test
2.7 K  /user/atguigu/test

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -du  -h /user/atguigu/test
1.3 K  /user/atguigu/test/README.txt
15     /user/atguigu/test/jinlian.txt
1.4 K  /user/atguigu/test/zaiyiqi.txt

11）-setrep：设置HDFS中文件的副本数量

[Mark@hadoop102 hadoop-3.1.3]$ hadoop fs -setrep 10 /sanguo/shuguo/kongming.txt