Apache Hadoop CLI

HDFS Command Line Interface

Users can interact with HDFS by executing shell like commands.

USAGE:
hadoop fs - <command> - <option> <URI>

Some distributions use dfs instead of fs and hdfs instead of hadoop.

Alternate USAGE:
hdfs dfs - <command> - <option> <URI>

URI format is scheme://host:port/path
e.g hdfs://localhost/ will list files from / directory

Most commands behave like Unix commands.
ls, cat, du

Supports HDFS specific operations. e.g changing replication. To get help type –help or display help for a specific command.
e.g hadoop fs –help <command_name>

Relative path: It works relative to user’s home directory, where home directory is /user/<username>

[-ls <path>]
[-lsr <path>]
[-df [<path>]]
[-du <path>]
[-dus <path>]
[-count[-q] <path>]
[-mv <src> <dst>]
[-cp <src> <dst>]
[-rm [-skipTrash] <path>]
[-rmr [-skipTrash] <path>]
[-expunge]
[-put <localsrc> ... <dst>]
[-copyFromLocal <localsrc> ... <dst>]
[-moveFromLocal <localsrc> ... <dst>]
[-get [-ignoreCrc] [-crc] <src> <localdst>]
[-getmerge <src> <localdst> [addnl]]
[-cat <src>]
[-text <src>]
[-copyToLocal [-ignoreCrc] [-crc] <src> <localdst>]
[-moveToLocal [-crc] <src> <localdst>]
[-mkdir <path>]
[-touchz <path>]
[-test -[ezd] <path>]
[-stat [format] <path>]
[-tail [-f] <file>]
[-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
[-chown [-R] [OWNER][:[GROUP]] PATH...]
[-chgrp [-R] GROUP PATH...]
[-help [cmd]]

cat – stream source to standard output
$ hadoop fs –cat /dir/readme.txt

cp – copy file in hdfs from source to destination
$ hadoop fs –cp /dir/file1 /otherdir/file1

ls – list file/s with stats in a directory
$ hadoop fs –ls /dir