Command
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What It Does
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Usage
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Examples
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dcat
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Copies source paths tostdout.
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hdfsdfs -cat URI [URI …]
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hdfsdfs -cat hdfs:// <path>/file1; hdfs dfs -cat file:///file2 /user/hadoop/file3
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chgrp
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Changes the group association of files. With -R, makes the change recursively by way of the directory structure. The user must be the file owner or the superuser.
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hdfsdfs -chgrp [-R] GROUP URI [URI …]
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chmod
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Changes the permissions of files. With -R, makes the change recursively by way of the directory structure. The user must be the file owner or the superuser.
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hdfsdfs -chmod [-R] <MODE[,MODE]... | OCTALMODE> URI [URI …]
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hdfsdfs -chmod 777 test/data1.txt
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chown
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Changes the owner of files. With -R, makes the change recursively by way of the directory structure. The user must be the superuser.
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hdfsdfs -chown [-R] [OWNER][:[GROUP]] URI [URI ]
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hdfsdfs -chown -R hduser2 /opt/hadoop/logs
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copyFromLocal
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Works similarly to the put command, except that the source is restricted to a local file reference.
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hdfsdfs -copyFromLocal<localsrc> URI
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hdfsdfs -copyFromLocal input/docs/data2.txt hdfs://localhost/user/ rosemary/data2.txt
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copyToLocal
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Works similarly to the getcommand, except that the destination is restricted to a local file reference.
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hdfsdfs -copyToLocal [-ignorecrc] [-crc] URI <localdst>
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hdfsdfs -copyToLocal data2.txt data2.copy.txt
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count
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Counts the number of directories, files, and bytes under the paths that match the specified file pattern.
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hdfsdfs -count [-q] <paths>
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hdfsdfs -count hdfs://nn1.example.com/ file1 hdfs://nn2.example.com/ file2
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cp
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Copies one or more files from a specified source to a specified destination. If you specify multiple sources, the specified destination must be a directory.
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hdfsdfs -cp URI [URI …] <dest>
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hdfsdfs -cp /user/hadoop/file1 /user/hadoop/file2 /user/hadoop/dir
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du
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Displays the size of the specified file, or the sizes of files and directories that are contained in the specified directory. If you specify the-s option, displays an aggregate summary of file sizes rather than individual file sizes. If you specify the-h option, formats the file sizes in a "human-readable" way.
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hdfsdfs -du [-s] [-h] URI [URI …]
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hdfsdfs -du /user/hadoop/dir1 /user/hadoop/file1
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dus
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Displays a summary of file sizes; equivalent to hdfsdfs -du –s.
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hdfsdfs -dus<args>
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expunge
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Empties the trash. When you delete a file, it isn’t removed immediately from HDFS, but is renamed to a file in the /trash directory. As long as the file remains there, you can undelete it if you change your mind, though only the latest copy of the deleted file can be restored.
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hdfsdfs –expunge
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get
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Copies files to the local file system. Files that fail a cyclic redundancy check (CRC) can still be copied if you specify the -ignorecrc option. The CRC is a common technique for detecting data transmission errors. CRC checksum files have the .crc extension and are used to verify the data integrity of another file. These files are copied if you specify the -crcoption.
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hdfsdfs -get [-ignorecrc] [-crc] <src><localdst>
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hdfsdfs -get /user/hadoop/file3 localfile
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getmerge
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Concatenates the files insrc and writes the result to the specified local destination file. To add a newline character at the end of each file, specify theaddnl option.
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hdfsdfs -getmerge<src><localdst> [addnl]
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hdfsdfs -getmerge /user/hadoop/mydir/ ~/result_fileaddnl
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ls
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Returns statistics for the specified files or directories.
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hdfsdfs -ls<args>
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hdfsdfs -ls /user/hadoop/file1
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lsr
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Serves as the recursive version of ls; similar to the Unix command ls -R.
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hdfsdfs -lsr<args>
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hdfsdfs -lsr /user/ hadoop
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mkdir
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Creates directories on one or more specified paths. Its behavior is similar to the Unix mkdir -p command, which creates all directories that lead up to the specified directory if they don’t exist already.
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hdfsdfs -mkdir<paths>
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hdfsdfs -mkdir /user/hadoop/dir5/temp
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moveFromLocal
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Works similarly to the putcommand, except that the source is deleted after it is copied.
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hdfsdfs -moveFromLocal<localsrc><dest>
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hdfsdfs -moveFromLocal localfile1 localfile2 /user/hadoop/hadoopdir
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mv
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Moves one or more files from a specified source to a specified destination. If you specify multiple sources, the specified destination must be a directory. Moving files across file systems isn’t permitted.
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hdfsdfs -mv URI [URI …] <dest>
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hdfsdfs -mv /user/hadoop/file1 /user/hadoop/file2
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put
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Copies files from the local file system to the destination file system. This command can also read input from stdin and write to the destination file system.
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hdfsdfs -put <localsrc> ... <dest>
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hdfsdfs -put localfile1 localfile2 /user/hadoop/hadoopdir; hdfsdfs -put - /user/hadoop/hadoopdir (reads input from stdin)
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rm
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Deletes one or more specified files. This command doesn’t delete empty directories or files. To bypass the trash (if it’s enabled) and delete the specified files immediately, specify the -skipTrashoption.
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hdfsdfs -rm [-skipTrash] URI [URI …]
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hdfsdfs -rm hdfs://nn.example.com/ file9
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rmr
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Serves as the recursive version of –rm.
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hdfsdfs -rmr [-skipTrash] URI [URI …]
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hdfsdfs -rmr /user/hadoop/dir
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setrep
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Changes the replication factor for a specified file or directory. With -R, makes the change recursively by way of the directory structure.
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hdfsdfs -setrep<rep> [-R] <path>
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hdfsdfs -setrep 3 -R /user/hadoop/dir1
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stat
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Displays information about the specified path.
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hdfsdfs -stat URI [URI …]
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hdfsdfs -stat /user/hadoop/dir1
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tail
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Displays the last kilobyte of a specified file to stdout. The syntax supports the Unix -f option, which enables the specified file to be monitored. As new lines are added to the file by another process, tailupdates the display.
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hdfsdfs -tail [-f] URI
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hdfsdfs -tail /user/hadoop/dir1
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test
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Returns attributes of the specified file or directory. Specifies -e to determine whether the file or directory exists; -z to determine whether the file or directory is empty; and -d to determine whether the URI is a directory.
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hdfsdfs -test -[ezd] URI
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hdfsdfs -test /user/hadoop/dir1
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text
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Outputs a specified source file in text format. Valid input file formats are zipandTextRecordInputStream.
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hdfsdfs -text <src>
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hdfsdfs -text /user/hadoop/file8.zip
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touchz
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Creates a new, empty file of size 0 in the specified path.
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hdfsdfs -touchz<path>
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hdfsdfs -touchz /user/hadoop/file12
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