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  • Hadoop之HDFS的Shell操作

    1、基本语法

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

      dfs 是 fs 的实现类。

    2、命令大全

    [hadoop@hadoop102 hadoop-2.7.2]$ bin/hadoop fs
    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]
        [-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 <path> ...]
        [-truncate [-w] <length> <path> ...]
        [-usage [cmd ...]]
    
    Generic options supported are
    -conf <configuration file>     specify an application configuration file
    -D <property=value>            use value for given property
    -fs <local|namenode:port>      specify a namenode
    -jt <local|resourcemanager:port>    specify a ResourceManager
    -files <comma separated list of files>    specify comma separated files to be copied to the map reduce cluster
    -libjars <comma separated list of jars>    specify comma separated jar files to include in the classpath.
    -archives <comma separated list of archives>    specify comma separated archives to be unarchived on the compute machines.
    
    The general command line syntax is
    bin/hadoop command [genericOptions] [commandOptions]

    3、常用命令操作

      1)-help:输出这个命令参数

    [hadoop@hadoop102 hadoop-2.7.2]$ bin/hadoop fs -help rm

      2)-ls:显示目录信息

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

      3)-mkdir:在HDFS上创建目录

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

      4)-moveFromLocal:从本地剪切粘贴到HDFS

    [hadoop@hadoop102 hadoop-2.7.2]$ touch test.txt
    [hadoop@hadoop102 hadoop-2.7.2]$ hadoop fs  -moveFromLocal  ./test.txt  /hadoop/test

      5)-appendToFile:追加一个文件到已经存在到文件末尾

    [hadoop@hadoop102 hadoop-2.7.2]$ touch liubei.txt
    [hadoop@hadoop102 hadoop-2.7.2]$ vi liubei.txt
    输入
    san gu mao lu
    [hadoop@hadoop102 hadoop-2.7.2]$ hadoop fs -appendToFile liubei.txt /sanguo/shuguo/kongming.txt

      6)-cat:显示文件内容

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

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

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

      注:hadoop文件系统中的文件并不能执行,因此没有执行权限。

      8)-copyFromLocal:从本地文件系统中拷贝文件到HDFS路径中去

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

      9)-copyToLocal:从HDFS拷贝到本地

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

      10)-cp:从HDFS的一个路径拷贝到HDFS的另一个路径

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

      11)-mv:在HDFS目录中移动文件

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

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

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

      13)-getmerge:合并下载多个文件,比如HDFS的目录 /user/hadoop/test 下有多个文件:log1,log2,log3...

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

      14)-put:等同于 copyFromLocal

    [hadoop@hadoop102 hadoop-2.7.2]$ hadoop fs -put ./zhangsan.txt /user/hadoop/test/

      15)-tail:显示一个文件的末尾

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

      16)-rm:删除文件或者文件夹

    [hadoop@hadoop102 hadoop-2.7.2]$ hadoop fs -rm /user/hadoop/test/jinlian2.txt
    [hadoop@hadoop102 hadoop-2.7.2]$ hadoop fs -rm -R /user/hadoop/test  #递归删除文件夹(无论文件夹下是否有文件都会删除)

      17)-rmdir:删除空目录

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

      18)-du:统计文件夹的大小信息

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

      19)-setrep:设置HDFS中文件的副本数量

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

       注意:这里设置的副本数只是记录在NameNode 的元数据中,是否真的会有这么多副本,还得看 DataNode 的数量。因为目前只有3台设备,最多也就3个副本,只有节点数增加到10台时,副本数才能达到10.

      

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  • 原文地址:https://www.cnblogs.com/jiang-chun/p/9932182.html
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