hadoop学习(六)----HDFS的shell操作

HDFS所有命令：

[uploaduser@rickiyang ~]$ 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]

1> –ls显示当前目录结构（从根路径开始）

[uploaduser@rickiyang ~]$ hadoop fs -ls /

2> -R递归显示目录结构

[uploaduser@rickiyang ~]$ hadoop fs -ls -R /

3> 创建带内容的文本

echo "hello world" > test1.txt

4> 上传文件

上传并重命名
[uploaduser@rickiyang tmp]$ hadoop fs -put t1.txt /tmp/test1.txt
上传文件夹
[uploaduser@rickiyang tmp]$ hadoop fs -put newPkg /tmp/pkg
一次上传多个文件
[uploaduser@rickiyang tmp]$ hadoop fs -put /tmp/t1.txt  /tmp/test1.txt
覆盖上传,如果根目录同一级有同名的文件则会覆盖，-f 表示强制覆盖
[uploaduser@rickiyang tmp]$ hadoop fs -put -f /tmp/test1.txt

5> 追加内容到文件末尾

[uploaduser@rickiyang tmp]$ hadoop fs -appendToFile /tmp/test2.txt
/user/uploadser/test1.txt

6> 查看HDFS某个文件的内容

[uploaduser@rickiyang tmp]$ hadoop fs -cat /user/uploaduser/test1.txt

7> 下载文件/目录

从HDFS到本地文件系统
[uploaduser@rickiyang ~]$ hadoop fs -get  /user/uploaduser/test2.txt /tmp/1.txt
与get等价的命令是copyToLocal
[uploaduser@rickiyang ~]$ hadoop fs -copyToLocal  /user/uploaduser/test2.txt /tmp/1.txt

其余的命令跟正常的linux命令大同小异，在实践中多多尝试。