HDFS的shell操作（開發重點)

1．基本文法

bin/hadoop fs 具體指令   OR  bin/hdfs dfs 具體指令

dfs是fs的實作類。

2．指令大全

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] <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 ...]]

3．常用指令實操

（0）啟動Hadoop叢集（友善後續的測試）

sbin/start-dfs.sh
 sbin/start-yarn.sh

（1）-help：輸出這個指令參數

hadoop fs -help rm

（2）-ls: 顯示目錄資訊

hadoop fs -ls /

（3）-mkdir：在HDFS上建立目錄

hadoop fs -mkdir -p /sanguo/shuguo

（4）-moveFromLocal：從本地剪切粘貼到HDFS

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

（5）-appendToFile：追加一個檔案到已經存在的檔案末尾

touch liubei.txt
 vi liubei.txt

輸入

san gu mao lu

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

（6）-cat：顯示檔案内容

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

（7）-chgrp 、-chmod、-chown：Linux檔案系統中的用法一樣，修改檔案所屬權限

hadoop fs  -chmod  666  /sanguo/shuguo/kongming.txt
 hadoop fs  -chown  dev1:dev1   /sanguo/shuguo/kongming.txt

（8）-copyFromLocal：從本地檔案系統中拷貝檔案到HDFS路徑去

hadoop fs -copyFromLocal README.txt /

（9）-copyToLocal：從HDFS拷貝到本地

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

（10）-cp ：從HDFS的一個路徑拷貝到HDFS的另一個路徑

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

（11）-mv：在HDFS目錄中移動檔案

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

（12）-get：等同于copyToLocal，就是從HDFS下載下傳檔案到本地

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

（13）-getmerge：合并下載下傳多個檔案，比如HDFS的目錄 /user/dev1/test下有多個檔案:log.1, log.2,log.3,…

hadoop fs -getmerge /user/dev1/test/* ./zaiyiqi.txt

（14）-put：等同于copyFromLocal

hadoop fs -put ./zaiyiqi.txt /user/dev1/test/

（15）-tail：顯示一個檔案的末尾

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

（16）-rm：删除檔案或檔案夾

hadoop fs -rm /user/dev1/test/jinlian2.txt

（17）-rmdir：删除空目錄

hadoop fs -mkdir /test
 hadoop fs -rmdir /test

（18）-du統計檔案夾的大小資訊

hadoop fs -du -s -h /user/dev1/test

2.7 K /user/dev1/test

hadoop fs -du  -h /user/dev1/test

1.3 K /user/dev1/test/README.txt

15 /user/dev1/test/jinlian.txt

1.4 K /user/dev1/test/zaiyiqi.txt

（19）-setrep：設定HDFS中檔案的副本數量

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

HDFS副本數量如圖

HDFS的shell操作（開發重點)