Hadoop-Shell 命令

hadoop fs 和 hadoop dfs 和 hdfs dfs 之间的区别

hadoop fs : 意思是说该命令可以用于其他文件系统，不止是hdfs文件系统内，也就是说该命令的使用范围更广
hadoop dfs : 已经弃用
hdfs dfs : 和hadoop dfs作用相同，相比于上面的命令更为推荐，并且当使用hadoop dfs时内部会被转为hdfs dfs命令

具体hdfs帮助命令

[root@server-1 home]# hdfs dfs -help
Usage: hadoop fs [generic options]
    [-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]
    [-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 <path> ...]
    [-usage [cmd ...]]

查看hdfs文件列表

[root@server-1 ~]# hdfs dfs -ls /
Found 6 items
-rw-r--r--   3 root          supergroup         78 2019-02-16 18:21 /hello.txt
-rw-r--r--   3 root          supergroup         93 2019-02-19 05:46 /input.txt
-rw-r--r--   3 root          supergroup  328530942 2019-02-16 18:18 /mysql-5.6.41-linux-glibc2.12-x86_64.tar.gz
-rw-r--r--   3 Administrator supergroup       8604 2019-02-16 23:27 /nginx.conf
-rw-r--r--   3 root          supergroup         93 2019-02-21 05:05 /wcinput
drwxr-xr-x   - Administrator supergroup          0 2019-02-21 06:17 /wcoutput

上传文件到hdfs

[root@server-1 home]# hdfs dfs -put /home/hadoopworld.txt /
[root@server-1 home]# hdfs dfs -ls /
Found 7 items
-rw-r--r--   3 root          supergroup        101 2019-03-10 07:37 /hadoopworld.txt
-rw-r--r--   3 root          supergroup         78 2019-02-16 18:21 /hello.txt
-rw-r--r--   3 root          supergroup         93 2019-02-19 05:46 /input.txt
-rw-r--r--   3 root          supergroup  328530942 2019-02-16 18:18 /mysql-5.6.41-linux-glibc2.12-x86_64.tar.gz
-rw-r--r--   3 Administrator supergroup       8604 2019-02-16 23:27 /nginx.conf
-rw-r--r--   3 root          supergroup         93 2019-02-21 05:05 /wcinput
drwxr-xr-x   - Administrator supergroup          0 2019-02-21 06:17 /wcoutput

将hdfs上的文件下载到本地

[root@server-1 home]# rm -rf hadoopworld.txt 
[root@server-1 home]# hdfs dfs -get /hadoopworld.txt /home/
[root@server-1 home]# ls
cmake-3.2.0.tar.gz              hadoop-2.6.5.tar.gz   kafka-eagle-web-1.2.4-bin.tar.gz            src
glibc-2.14.tar.bz2              hadoopworld.txt       mysql-5.6.39.tar.gz                         xuzy
glibc-linuxthreads-2.5.tar.bz2  kafka_2.11-2.0.0.tgz  mysql-5.6.41-linux-glibc2.12-x86_64.tar.gz  zookeeper-3.4.12.tar.gz

查看hdfs上的文件内容

[root@server-1 home]# hdfs dfs -cat /hello.txt
werewr
ewtertert
rytryrty
werwerwe
rtret

将本地文件的文件内容以追加的方式追加到hdfs文件中

[root@server-1 home]# echo 'xuzhiyong is a good man' > /home/xuzy.txt
[root@server-1 home]# hdfs dfs -appendToFile xuzy.txt /hello.txt

递归删除hdfs文件目录

[root@server-1 home]# hdfs dfs -rm -r /wcoutput
19/03/10 07:58:22 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 0 minutes, Emptier interval = 0 minutes.
Deleted /wcoutput

在hdfs上创建一个文件

[root@server-1 home]# hdfs dfs -touchz /xuzy.txt
[root@server-1 home]# hdfs dfs -ls /
Found 6 items
-rw-r--r--   3 root          supergroup        101 2019-03-10 07:37 /hadoopworld2.txt
-rw-r--r--   3 root          supergroup        102 2019-03-10 07:49 /hello.txt
-rw-r--r--   3 root          supergroup         93 2019-02-19 05:46 /input.txt
-rw-r--r--   3 root          supergroup  328530942 2019-02-16 18:18 /mysql-5.6.41-linux-glibc2.12-x86_64.tar.gz
-rw-r--r--   3 Administrator supergroup       8604 2019-02-16 23:27 /nginx.conf
-rw-r--r--   3 root          supergroup          0 2019-03-10 07:59 /xuzy.txt

递归创建一个hdfs目录

[root@server-1 home]# hdfs dfs -mkdir -p /xuzhiyong/01

将本地的文件移到hdfs指定文件下

[root@server-1 home]# hdfs dfs -moveFromLocal xuzy01.txt /xuzhiyong/01

为hdfs指定文件或者目录赋予权限

[root@server-1 home]# hdfs dfs -chmod -R 777 /xuzhiyong