The File System (FS) shell includes various shell-like commands that directly interact with the Hadoop Distributed File System (HDFS) as well as other file systems that Hadoop supports, such as Local FS, HFTP FS, S3 FS, and others. The FS shell is invoked by:
bin/hadoop fs <args>
All FS shell commands take path URIs as arguments. The URI format is scheme://authority/path. For HDFS the scheme is hdfs, and for the Local FS 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://namenodehost/parent/child or simply as /parent/child (given that your configuration is set to point to hdfs://namenodehost).
Most of the commands in FS 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: hdfs dfs -cat URI [URI ...]
Copies source paths to stdout.
Example:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs 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 Guide.
Usage: hdfs 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 Guide.
Usage: hdfs 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 Guide.
Usage: hdfs dfs -copyFromLocal <localsrc> URI
Similar to put command, except that the source is restricted to a local file reference.
Usage: hdfs dfs -copyToLocal [-ignorecrc] [-crc] URI <localdst>
Similar to get command, except that the destination is restricted to a local file reference.
Usage: hdfs dfs -count [-q] <paths>
Count the number of directories, files and bytes under the paths that match the specified file pattern. The output columns with -count are: DIR_COUNT, FILE_COUNT, CONTENT_SIZE FILE_NAME
The output columns with -count -q are: QUOTA, REMAINING_QUATA, SPACE_QUOTA, REMAINING_SPACE_QUOTA, DIR_COUNT, FILE_COUNT, CONTENT_SIZE, FILE_NAME
Example:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs 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:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs dfs -du [-s] [-h] URI [URI ...]
Displays sizes of files and directories contained in the given directory or the length of a file in case its just a file.
Options:
Example:
Exit Code: Returns 0 on success and -1 on error.
Usage: hdfs dfs -dus <args>
Displays a summary of file lengths. This is an alternate form of hdfs dfs -du -s.
Usage: hdfs dfs -expunge
Empty the Trash. Refer to the HDFS Architecture Guide for more information on the Trash feature.
Usage: hdfs 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:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs 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: hdfs dfs -ls <args>
For a file returns stat on the file with the following format:
permissions number_of_replicas userid groupid filesize modification_date modification_time filename
For a directory it returns list of its direct children as in unix.A directory is listed as:
permissions userid groupid modification_date modification_time dirname
Example:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs dfs -mkdir [-p] <paths>
Takes path uri's as argument and creates directories. With -p the behavior is much like unix mkdir -p creating parent directories along the path.
Example:
Exit Code:
Returns 0 on success and -1 on error.
Usage: dfs -moveFromLocal <localsrc> <dst>
Similar to put command, except that the source localsrc is deleted after it's copied.
Usage: hdfs dfs -moveToLocal [-crc] <src> <dst>
Displays a "Not implemented yet" message.
Usage: hdfs 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 file systems is not permitted.
Example:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs dfs -put <localsrc> ... <dst>
Copy single src, or multiple srcs from local file system to the destination file system. Also reads input from stdin and writes to destination file system.
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs dfs -rm [-skipTrash] URI [URI ...]
Delete files specified as args. Only deletes non empty directory and files. If the -skipTrash option is specified, the trash, if enabled, will be bypassed and the specified file(s) deleted immediately. This can be useful when it is necessary to delete files from an over-quota directory. Refer to rmr for recursive deletes.
Example:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs dfs -rmr [-skipTrash] URI [URI ...]
Recursive version of delete. If the -skipTrash option is specified, the trash, if enabled, will be bypassed and the specified file(s) deleted immediately. This can be useful when it is necessary to delete files from an over-quota directory.
Example:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs 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:
Exit Code:
Returns 0 on success and -1 on error.
Usage: hdfs dfs -stat URI [URI ...]
Returns the stat information on the path.
Example:
Exit Code: Returns 0 on success and -1 on error.
Usage: hdfs dfs -tail [-f] URI
Displays last kilobyte of the file to stdout. -f option can be used as in Unix.
Example:
Exit Code: Returns 0 on success and -1 on error.
Usage: hdfs 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 to see if the path is directory. Return 0 if true. |
Example: