Hadoop Shell Commands

The HDFS shell is invoked by bin/hadoop dfs <args>. All the HDFS shell commands take path URIs as arguments. The URI format is scheme://autority/path. For HDFS the scheme is hdfs, and for the local filesystem the scheme is file. The scheme and authority are optional. If not specified, the default scheme specified in the configuration is used. An HDFS file or directory such as /parent/child can be specified as hdfs://namenode:namenodeport/parent/child or simply as /parent/child (given that your configuration is set to point to namenode:namenodeport). Most of the commands in HDFS shell behave like corresponding Unix commands. Differences are described with each of the commands. Error information is sent to stderr and the output is sent to stdout.

Usage: hadoop dfs -cat URI [URI …]

Copies source paths to stdout.

Example:

• hadoop dfs -cat hdfs://host1:port1/file1 hdfs://host2:port2/file2
• hadoop dfs -cat file:///file3 /user/hadoop/file4

Exit Code:
Returns 0 on success and -1 on error.

Usage: hadoop dfs -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.

Usage: hadoop dfs -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.

Usage: hadoop dfs -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.

Usage: hadoop dfs -copyFromLocal <localsrc> URI

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

Usage: hadoop dfs -copyToLocal [-ignorecrc] [-crc] URI <localdst>

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

Usage: hadoop dfs -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.
Example:

• hadoop dfs -cp /user/hadoop/file1 /user/hadoop/file2
• hadoop dfs -cp /user/hadoop/file1 /user/hadoop/file2 /user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

Usage: hadoop dfs -du URI [URI …]

Displays aggregate length of files contained in the directory or the length of a file in case its just a file.
Example:
hadoop dfs -du /user/hadoop/dir1 /user/hadoop/file1 hdfs://host:port/user/hadoop/dir1
Exit Code:
Returns 0 on success and -1 on error.

Usage: hadoop dfs -dus <args>

Displays a summary of file lengths.

Usage: hadoop dfs -expunge

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

Usage: hadoop dfs -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.

Example:

• hadoop dfs -get /user/hadoop/file localfile
• hadoop dfs -get hdfs://host:port/user/hadoop/file localfile

Exit Code:

Returns 0 on success and -1 on error.

Usage: hadoop dfs -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.

Usage: hadoop dfs -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
Example:
hadoop dfs -ls /user/hadoop/file1 /user/hadoop/file2 hdfs://host:port/user/hadoop/dir1 /nonexistentfile
Exit Code:
Returns 0 on success and -1 on error.

Usage: hadoop dfs -lsr <args>
Recursive version of ls. Similar to Unix ls -R.

Usage: hadoop dfs -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.

Example:

• hadoop dfs -mkdir /user/hadoop/dir1 /user/hadoop/dir2
• hadoop dfs -mkdir hdfs://host1:port1/user/hadoop/dir hdfs://host2:port2/user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

Usage: dfs -moveFromLocal <src> <dst>

Displays a "not implemented" message.

Usage: hadoop dfs -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.
Example:

• hadoop dfs -mv /user/hadoop/file1 /user/hadoop/file2
• hadoop dfs -mv hdfs://host:port/file1 hdfs://host:port/file2 hdfs://host:port/file3 hdfs://host:port/dir1

Exit Code:

Returns 0 on success and -1 on error.

Usage: hadoop dfs -put <localsrc> <dst>

Copy src from local file system to the destination filesystem. Also reads input from stdin and writes to destination filesystem.

• hadoop dfs -put localfile /user/hadoop/hadoopfile
• hadoop dfs -put localfile hdfs://host:port/hadoop/hadoopfile
• hadoop dfs -put - hdfs://host:port/hadoop/hadoopfile
  Reads the input from stdin.

Exit Code:

Returns 0 on success and -1 on error.

Usage: hadoop dfs -rm URI [URI …]

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

• hadoop dfs -rm hdfs://host:port/file /user/hadoop/emptydir

Exit Code:

Returns 0 on success and -1 on error.

Usage: hadoop dfs -rmr URI [URI …]

Recursive version of delete.
Example:

• hadoop dfs -rmr /user/hadoop/dir
• hadoop dfs -rmr hdfs://host:port/user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

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

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

Example:

• hadoop dfs -setrep -w 3 -R /user/hadoop/dir1

Exit Code:

Returns 0 on success and -1 on error.

Usage: hadoop dfs -stat URI [URI …]

Returns the stat information on the path.

Example:

• hadoop dfs -stat path

Exit Code:
Returns 0 on success and -1 on error.

Usage: hadoop dfs -tail [-f] URI

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

Example:

• hadoop dfs -tail pathname

Exit Code:
Returns 0 on success and -1 on error.

Usage: hadoop dfs -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.

Example:

• hadoop dfs -test -e filename

Usage: hadoop dfs -text <src>

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

Usage: hadoop dfs -touchz URI [URI …]

Create a file of zero length.

Example:

• hadoop -touchz pathname

Exit Code:
Returns 0 on success and -1 on error.