hadoop shell命令介绍

Hadoop 文件系统shell使用命令介绍，基本上所有的命令与linux命令相差不大，下面为我的hadoop系统文件夹

查看命令：hadoop fs -ls /home/hadoop/

drwxr-xr-x   - hadoop supergroup          0 2013-11-30 17:51 /home/hadoop/dir

drwxr-xr-x   - hadoop supergroup          0 2013-11-30 17:48 /home/hadoop/input

-rw-r--r--   1 hadoop supergroup         64 2013-11-30 17:50 /home/hadoop/ouput

drwxr-xr-x   - hadoop supergroup          0 2013-11-29 22:50 /home/hadoop/output

drwxr-xr-x   - hadoop supergroup          0 2013-11-29 22:50 /home/hadoop/tmp

查看所有命令帮助：hadoop fs --help

cat

Usage: hadoop fs -cat URI [URI …]

查看fs文件内容

例子:

hadoop fs -cat /home/hadoop/input/content.txt

Returns 0 on success and -1 on error.

chgrp

Usage: hadoop fs -chgrp [-R] GROUP URI [URI …]

Change group association of files. With -R, make the change recursively through
the directory structure. The user must be the owner of files, or else a super-user. Additional information is in the Permissions
User Guide.

chmod

Usage: hadoop fs -chmod [-R] <MODE[,MODE]... | OCTALMODE> URI [URI …]

Change the permissions of files. With -R, make the change recursively through the
directory structure. The user must be the owner of the file, or else a super-user. Additional information is in the Permissions
User Guide.

chown

Usage: hadoop fs -chown [-R] [OWNER][:[GROUP]] URI [URI ]

Change the owner of files. With -R, make the change recursively through the directory
structure. The user must be a super-user. Additional information is in the Permissions User Guide.

copyFromLocal

Usage: hadoop fs -copyFromLocal <localsrc> URI

例子：

hadoop fs -copyFromLocal /home/hadoop/address /home/hadoop/input

Similar to put command,
except that the source is restricted to a local file reference.

copyToLocal

Usage: hadoop fs -copyToLocal [-ignorec
4000
rc] [-crc] URI <localdst>

例子：

hadoop fs -copyToLocal /home/hadoop/input/content.txt /home/hadoop/mylocal

Similar to get command,
except that the destination is restricted to a local file reference.

cp

Usage: hadoop fs -cp URI [URI …] <dest>

Copy files from source to destination. This command allows multiple sources as
well in which case the destination must be a directory. 

例子:

hadoop fs -cp /home/hadoop/input/content.txt /home/hadoop/ouput

hadoop fs -cp /home/hadoop/input/address /home/hadoop/ouput /home/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

du

Usage: hadoop fs -du URI [URI …]

Displays aggregate length of files contained in the directory or the length of
a file in case its just a file.
例子:
hadoop fs -du /home/hadoop/dir /home/hadoop/input

输出结果：

[align=left]Found 2 items[/align]
[align=left]65          hdfs://localhost:9000/home/hadoop/dir/address[/align]
[align=left]64          hdfs://localhost:9000/home/hadoop/dir/ouput[/align]
[align=left]Found 2 items[/align]
[align=left]65          hdfs://localhost:9000/home/hadoop/input/address[/align]
[align=left]64          hdfs://localhost:9000/home/hadoop/input/content.txt[/align]

Exit Code:

Returns 0 on success and -1 on error. 

dus

Usage: hadoop fs -dus <args>

例子：

hadoop fs -dus /home/hadoop/dir

输出：hdfs://localhost:9000/home/hadoop/dir 
      129

Displays a summary of file lengths.

expunge 手动清除fs回收站

Usage: hadoop fs -expunge

Empty the Trash. Refer to HDFS
Design for more information on Trash feature.

get

Usage: hadoop fs -get [-ignorecrc] [-crc] <src> <localdst> 

Copy files to the local file system. Files that fail the CRC check may be copied
with the -ignorecrc option. Files and CRCs may be copied using the -crc option.

例子:

hadoop fs -get /home/hadoop/input/content.txt /home/hadoop/mylocal/

hadoop fs -get hdfs://nn.example.com/user/hadoop/file localfile

Exit Code:

Returns 0 on success and -1 on error.

getmerge

Usage: hadoop fs -getmerge <src> <localdst> [addnl]

Takes a source directory and a destination file as input and concatenates files
in src into the destination local file. Optionally addnl can be set to enable adding a newline character at the end of each file.

ls

Usage: hadoop fs -ls <args>

For a file returns stat on the file with the following format:
filename <number of replicas> filesize modification_date modification_time permissions userid groupid 
For a directory it returns list of its direct children as in unix. A directory is listed as: 
dirname <dir> modification_time modification_time permissions userid groupid 
例子:
hadoop fs -ls /home/hadoop/input/ /home/hadoop/ouput/

输出：

[align=left]Found 2 items[/align]
[align=left]-rw-r--r--   1 hadoop supergroup         65 2013-11-30 17:48 /home/hadoop/input/address[/align]
[align=left]-rw-r--r--   1 hadoop supergroup         64 2013-11-29 22:48 /home/hadoop/input/content.txt[/align]
[align=left]Found 1 items[/align]
[align=left]-rw-r--r--   1 hadoop supergroup         64 2013-11-30 17:50 /home/hadoop/ouput[/align]
Exit Code:
Returns 0 on success and -1 on error. 

lsr

Usage: hadoop fs -lsr <args>

例子：

hadoop fs -lsr /home/hadoop/input/ /home/hadoop/ouput/

输出：

[align=left
f048
]-rw-r--r--   1 hadoop supergroup         65 2013-11-30 17:48 /home/hadoop/input/address[/align]
[align=left]-rw-r--r--   1 hadoop supergroup         64 2013-11-29 22:48 /home/hadoop/input/content.txt[/align]
[align=left]-rw-r--r--   1 hadoop supergroup         64 2013-11-30 17:50 /home/hadoop/ouput[/align]
Recursive version of ls. Similar to Unix ls -R.

mkdir

Usage: hadoop fs -mkdir <paths> 

Takes path uri's as argument and creates directories. The behavior is much like
unix mkdir -p creating parent directories along the path.

例子:

hadoop fs -mkdir /home/hadoop/input/ /home/hadoop/ouput/

hadoop fs -mkdir hdfs://nn1.example.com/user/hadoop/dir hdfs://nn2.example.com/user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

movefromLocal

Usage: dfs -moveFromLocal <src> <dst>

Displays a "not implemented" message.

mv

Usage: hadoop fs -mv URI [URI …] <dest>

Moves files from source to destination. This command allows multiple sources as
well in which case the destination needs to be a directory. Moving files across filesystems is not permitted. 

例子:

hadoop fs -mv /home/hadoop/input/lzw /home/hadoop/output

hadoop fs -mv hdfs://nn.example.com/file1 hdfs://nn.example.com/file2 hdfs://nn.example.com/file3 hdfs://nn.example.com/dir1

Exit Code:

Returns 0 on success and -1 on error.

put

Usage: hadoop fs -put <localsrc> ... <dst>

Copy single src, or multiple srcs from local file system to the destination filesystem.
Also reads input from stdin and writes to destination filesystem.

hadoop fs -put /home/hadoop/lzw /home/hadoop/input

hadoop fs -put /home/hadoop/lzw /home/hadoop/lzw1 /home/hadoop/input

hadoop fs -put localfile hdfs://nn.example.com/hadoop/hadoopfile

hadoop fs -put - hdfs://nn.example.com/hadoop/hadoopfile 

Reads the input from stdin.

Exit Code:

Returns 0 on success and -1 on error.

rm 删除文件

Usage: hadoop fs -rm URI [URI …]

Delete files specified as args. Only deletes non empty directory and files. Refer
to rmr for recursive deletes.

例子:

hadoop fs -rm /home/hadoop/output/lzw

Exit Code:

Returns 0 on success and -1 on error.

rmr 删除文件夹

Usage: hadoop fs -rmr URI [URI …]

Recursive version of delete.

例子:

hadoop fs -rmr /home/hadoop/output

hadoop fs -rmr hdfs://nn.example.com/user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

setrep

Usage: hadoop fs -setrep [-R] <path>

Changes the replication factor of a file. -R option is for recursively increasing
the replication factor of files within a directory.

例子:

hadoop fs -setrep -w 3 -R /user/hadoop/dir1

Exit Code:

Returns 0 on success and -1 on error.

stat

Usage: hadoop fs -stat URI [URI …]

Returns the stat information on the path.

例子:

hadoop fs -stat /home/hadoop/input

输出：

2013-11-30 16:00:27

Exit Code:

Returns 0 on success and -1 on error.

tail

Usage: hadoop fs -tail [-f] URI

Displays last kilobyte of the file to stdout. -f option can be used as in Unix.

例子:

hadoop fs -tail pathname

Exit Code: 

Returns 0 on success and -1 on error.

test

Usage: hadoop fs -test -[ezd] URI

Options: 

-e check to see if the file exists. Return 0 if true. 

-z check to see if the file is zero length. Return 0 if true 

-d check return 1 if the path is directory else return 0. 

例子:

hadoop fs -test -d /home/hadoop/input

hadoop fs -test -e /home/hadoop/input

hadoop fs -test -z /home/hadoop/input

text 查看文件内容，跟cat基本相似

Usage: hadoop fs -text <src>

例子：

hadoop fs -text /home/hadoop/input/address

输出：

[align=left]addressID        addressname[/align]
[align=left]1        Beijing[/align]
[align=left]2        Guangzhou[/align]
[align=left]3        Shenzhen[/align]
[align=left]4        Xian[/align]

Takes a source file and outputs the file in text format. The allowed formats are
zip and TextRecordInputStream.

touchz 创建空文件

Usage: hadoop fs -touchz URI [URI …] 

Create a file of zero length.

例子:

hadoop fs -touchz /home/hadoop/input/lzw

Exit Code:

Returns 0 on success and -1 on error.