HDFS的shell命令

ゝ一纸荒年。 2022-08-30 11:19 212阅读 0赞

## 1、启动和帮助命令 ##

1）启动 Hadoop 集群（方便后续的测试）

[yasin@hadoop102 hadoop-3.3.1]$ sbin/start-dfs.sh
    [yasin@hadoop103 hadoop-3.3.1]$ sbin/start-yarn.sh

2）-help：输出这个命令参数

[yasin@hadoop102 hadoop-3.3.1]$ hadoop fs -help rm

3）创建/sanguo 文件夹

[yasin@hadoop102 hadoop-3.3.1]$ hadoop fs -mkdir /sanguo

## 2、上传 ##

1）-moveFromLocal：从本地剪切粘贴到 HDFS

[yasin@hadoop102 hadoop-3.3.1]$ vim shuguo.txt

输入：  
shuguo

[yasin@hadoop102 hadoop-3.3.1]$ hadoop fs -moveFromLocal ./shuguo.txt
    /sanguo

2）-copyFromLocal：从本地文件系统中拷贝文件到 HDFS 路径去

[yasin@hadoop102 hadoop-3.3.1]$ vim weiguo.txt

输入：  
weiguo

[yasin@hadoop102 hadoop-3.3.1]$ hadoop fs -copyFromLocal weiguo.txt
    /sanguo

3）-put：等同于 copyFromLocal，生产环境更习惯用 put  
\[yasin@hadoop102 hadoop-3.3.1\]$ vim wuguo.txt  
输入：  
wuguo

[yasin@hadoop102 hadoop-3.3.1]$ hadoop fs -put ./wuguo.txt /sanguo

4）-appendToFile：追加一个文件到已经存在的文件末尾

[yasin@hadoop102 hadoop-3.3.1]$ vim liubei.txt

输入：  
liubei

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -appendToFile liubei.txt /sanguo/shuguo.txt

## 3、下载 ##

1）-copyToLocal：从 HDFS 拷贝到本地

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -copyToLocal /sanguo/shuguo.txt ./

2）-get：等同于 copyToLocal，生产环境更习惯用 get

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -get /sanguo/shuguo.txt ./shuguo2.txt

## 4、hdfs直接操作 ##

1）-ls: 显示目录信息

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -ls /sanguo
    Found 3 items
    -rw-r--r--   3 yasin supergroup         14 2021-07-19 19:53 /sanguo/shuguo.txt
    -rw-r--r--   3 yasin supergroup          7 2021-07-19 19:50 /sanguo/weiguo.txt
    -rw-r--r--   3 yasin supergroup          6 2021-07-19 19:51 /sanguo/wuguo.txt

2）-cat：显示文件内容

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -cat /sanguo/shuguo.txt
    shuguo
    liubei

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

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -chmod 666 /sanguo/shuguo.txt
    [yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -chown yasin:yasin /sanguo/shuguo.txt

4）-mkdir：创建路径

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -mkdir /jinguo

5）-cp：从 HDFS 的一个路径拷贝到 HDFS 的另一个路径

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -cp /sanguo/shuguo.txt /jinguo

6）-mv：在 HDFS 目录中移动文件

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -mv /sanguo/wuguo.txt /jinguo
    [yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -mv /sanguo/weiguo.txt /jinguo
    /jinguo

7）-tail：显示一个文件的末尾 1kb 的数据

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -tail /jinguo/shuguo.txt
    shuguo
    liubei

8）-rm：删除文件或文件夹

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -rm /sanguo/shuguo.txt
    Deleted /sanguo/shuguo.txt

9）-rm -r：递归删除目录及目录里面内容

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -rm -r /sanguo
    Deleted /sanguo

10）-du 统计文件夹的大小信息

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -du -s -h /jinguo
    27  81  /jinguo

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -du -h /jinguo
    14  42  /jinguo/shuguo.txt
    7   21  /jinguo/weiguo.txt
    6   18  /jinguo/wuguo.txt

说明：27 表示文件大小；81 表示 27\*3 个副本；/jinguo 表示查看的目录

11）-setrep：设置 HDFS 中文件的副本数量

[yasin@haddoop102 hadoop-3.3.1]$ hadoop fs -setrep 10 /jinguo/shuguo.txt
    Replication 10 set: /jinguo/shuguo.txt