hadoop的shelll操作

文章目录

• • 
    
• ​​1.基本语法​​
• ​​2.命令大全​​
  • 
    

1.基本语法

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

dfs是fs的实现类

2.命令大全

[-appendToFile <localsrc> ... <dst>]
        [-cat [-ignoreCrc] <src> ...]
        [-checksum <src> ...]
        [-chgrp [-R] GROUP PATH...]
        [-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
        [-chown [-R] [OWNER][:[GROUP]] PATH...]
        [-copyFromLocal [-f] [-p] <localsrc> ... <dst>]
        [-copyToLocal [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
        [-count [-q] <path> ...]
        [-cp [-f] [-p] <src> ... <dst>]
        [-createSnapshot <snapshotDir> [<snapshotName>]]
        [-deleteSnapshot <snapshotDir> <snapshotName>]
        [-df [-h] [<path> ...]]
        [-du [-s] [-h] <path> ...]
        [-expunge]
        [-get [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
        [-getfacl [-R] <path>]
        [-getmerge [-nl] <src> <localdst>]
        [-help [cmd ...]]
        [-ls [-d] [-h] [-R] [<path> ...]]
        [-mkdir [-p] <path> ...]
        [-moveFromLocal <localsrc> ... <dst>]
        [-moveToLocal <src> <localdst>]
        [-mv <src> ... <dst>]
        [-put [-f] [-p] <localsrc> ... <dst>]
        [-renameSnapshot <snapshotDir> <oldName> <newName>]
        [-rm [-f] [-r|-R] [-skipTrash] <src> ...]
        [-rmdir [--ignore-fail-on-non-empty] <dir> ...]
        [-setfacl [-R] [{-b|-k} {-m|-x <acl_spec>} <path>]|[--set <acl_spec> <path>]]
        [-setrep [-R] [-w] <rep> <path> ...]
        [-stat [format] <path> ...]
        [-tail [-f] <file>]
        [-test -[defsz] <path>]
        [-text [-ignoreCrc] <src> ...]
        [-touchz <path> ...]
        [-usage [cmd ...]]

-help：输出这个命令参数

hadoop fs -help rm

-ls: 显示目录信息

hadoop fs -ls /

-mkdir：在HDFS上创建目录

hadoop fs -mkdir -p /sanguo/shuguo

-moveFromLocal：从本地剪切粘贴到HDFS

hadoop fs -moveFromLocal ./kongming.txt /sanguo/shuguo

-appendToFile：追加一个文件到已经存在的文件末尾

hadoop fs -appendToFile liubei.txt /sanguo/shuguo/kongming.txt

-cat：显示文件内容

hadoop fs -cat /sanguo/shuguo/kongming.txt

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

hadoop fs -chmod 666 /sanguo/shuguo/kongming.txt

-copyFromLocal：从本地文件系统中拷贝文件到HDFS路径去

hadoop fs -copyFromLocal README.txt /

-copyToLocal：从HDFS拷贝到本地

hadoop fs -copyToLocal /sanguo/shuguo/kongming.txt ./

-cp ：从HDFS的一个路径拷贝到HDFS的另一个路径

hadoop fs -cp /sanguo/shuguo/kongming.txt /zhuge.txt

-mv：在HDFS目录中移动文件

hadoop fs -mv /zhuge.txt /sanguo/shuguo/

-get：等同于copyToLocal，就是从HDFS下载文件到本地

hadoop fs -get /sanguo/shuguo/kongming.txt ./

-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,…

hadoop fs -getmerge /user/atguigu/test/* ./zaiyiqi.txt

-put：等同于copyFromLocal

hadoop fs -put ./zaiyiqi.txt /sanguo/shuguo/kongming.txt

-tail：显示一个文件的末尾

hadoop fs -tail /sanguo/shuguo/kongming.txt

-rm：删除文件或文件夹

hadoop fs -rm /user/atguigu/test/jinlian2.txt

-rmdir：删除空目录

hadoop fs -mkdir /test

-du : 统计文件夹的大小信息

hadoop fs -du -s -h /user/atguigu/test

-setrep：设置HDFS中文件的副本数量

hadoop fs -setrep 10 /sanguo/shuguo/kongming.txt

这里的副本数只是记录在NameNode的元数据中,是否真的有那么多副本还要看DataNode的数量,因为目前只有3台设备，最多也就3个副本，只有节点数的增加到10台时，副本数才能达到10