HDFS 之 Shell 操作

1.基本语法

bin/hadoop fs 具体命令

2.命令大全

[luomk@hadoop102 hadoop-2.7.2]$ bin/hadoop fs

 
   [-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] [-l] <localsrc> ... <dst>] 
  
   [-copyToLocal [-p] [-ignoreCrc] [-crc] <src> ... <localdst>] 
  
   [-count [-q] [-h] <path> ...] 
  
   [-cp [-f] [-p | -p[topax]] <src> ... <dst>] 
  
   [-createSnapshot <snapshotDir> [<snapshotName>]] 
  
   [-deleteSnapshot <snapshotDir> <snapshotName>] 
  
   [-df [-h] [<path> ...]] 
  
   [-du [-s] [-h] <path> ...] 
  
   [-expunge] 
  
   [-find <path> ... <expression> ...] 
  
   [-get [-p] [-ignoreCrc] [-crc] <src> ... <localdst>] 
  
   [-getfacl [-R] <path>] 
  
   [-getfattr [-R] {-n name | -d} [-e en] <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] [-l] <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>]] 
  
   [-setfattr {-n name [-v value] | -x name} <path>] 
  
   [-setrep [-R] [-w] <rep> <path> ...] 
  
   [-stat [format] <path> ...] 
  
   [-tail [-f] <file>] 
  
   [-test -[defsz] <path>] 
  
   [-text [-ignoreCrc] <src> ...] 
  
   [-touchz <路径> ...] 
  
   [-truncate [-w] <length> <path> ...] 
  
   [-usage [cmd ...]]

3.常用命令实操

（0）启动的Hadoop集群（方便后续的测试）

 
   [luomk @ hadoop102 hadoop-2.7.2] $ sbin / start-dfs.sh 
  
   [luomk @ hadoop103 hadoop-2.7.2] $ sbin / start-yarn.sh

（1）-help：输出这个命令参数

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -help rm 
 

（2）-ls：显示目录信息

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -ls / 
 

（3）-mkdir：在HDFS上创建目录

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -mkdir -p / sanguo / shuguo 
 

（4）-moveFromLocal从本地剪切粘贴到hdfs

 
   [luomk @ hadoop102 hadoop-2.7.2] $ touch kongming.txt 
  
   [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -moveFromLocal ./kongming.txt / sanguo / shuguo

（5） - appendToFile：追加一个文件到已经存在的文件末尾

 
   [luomk @ hadoop102 hadoop-2.7.2] $ touch liubei.txt 
  
   [luomk @ hadoop102 hadoop-2.7.2] $ vi liubei.txt 
  
   输入 
  
   三谷毛禄 
  
   [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -appendToFile liubei.txt /sanguo/shuguo/kongming.txt

（6）-cat：显示文件内容

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -cat /sanguo/shuguo/kongming.txt 
 

（7）-tail：显示一个文件的末尾

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -tail /sanguo/shuguo/kongming.txt 
 

（8）-chgrp，-chmod，-chown：linux文件系统中的用法一样，修改文件所属权限

 
   [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -chmod 666 /sanguo/shuguo/kongming.txt 
  
   [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -chown luomk：luomk /sanguo/shuguo/kongming.txt

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

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -copyFromLocal README.txt / 
 

（10）-copyToLocal：从HDFS拷贝到本地

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -copyToLocal /sanguo/shuguo/kongming.txt ./ 
 

（11）-cp：从hdfs的一个路径拷贝到hdfs的另一个路径

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -cp /sanguo/shuguo/kongming.txt /zhuge.txt 
 

（12）-mv：在HDFS目录中移动文件

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -mv /zhuge.txt / sanguo / shuguo / 
 

（13）-get：等同于copyToLocal，就是从HDFS下载文件到本地

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -get /sanguo/shuguo/kongming.txt ./ 
 

（14）-getmerge：合并下载多个文件，比如hdfs的目录/ aaa /下有多个文件：log.1，log.2，log.3，...

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -getmerge / user / luomk / test / * ./zaiyiqi.txt 
 

（15）-put：等同于copyFromLocal

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -put ./zaiyiqi.txt / user / luomk / 
 

（16）-rm：删除文件或文件夹（可以递归全部删除）

 
  [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -rm /user/luomk/test/jinlian2.txt 
 

（17）-rmdir：删除空目录

 
   [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -mkdir / test 
  
   [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -rmdir / test

（18）-du统计文件夹的大小信息

 
   [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -du -s -h / user / luomk / test 
  
         2.7 K /用户/ luomk /测试 
  
   [luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -du -h / user / luomk / test 
  
         1.3 K /user/luomk/test/README.txt 
  
         15 /user/luomk/test/jinlian.txt 
  
         1.4 K /user/luomk/test/zaiyiqi.txt

（19）-setrep：设置HDFS中文件的副本数量

[luomk @ hadoop102 hadoop-2.7.2] $ hadoop fs -setrep 10 /sanguo/shuguo/kongming.txt

这里设置的副本数只是记录在的NameNode的元数据中，是否真的会有这么多副本，还得看数据管理部的数量。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。

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