Hadoop Basic Commands

Hadoop Commands
No	Command	Command Usage	Description
1	cat	hadoop dfs -cat <path>	prints the file contents
2	chgrp	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.
3	chmod	hadoop dfs -chmod [-R] <MODE[,MODE]... | OCTALMODE> URI
4	chown	hadoop dfs -chown [-R] [OWNER][:[GROUP]] URI [URI ]
5	copyFromLocal	hadoop dfs -copyFromLocal <localsrc> URI
6	copyToLocal	hadoop dfs -copyToLocal [-ignorecrc] [-crc] URI
7	count	hadoop dfs -count [-q] <paths>
8	cp	hadoop dfs -cp URI [URI …] <dest>
9	du	hadoop dfs -du URI [URI …]	Get size of each file in dir
10	dus	hadoop dfs -dus URI [URI …]	Gets total file size
11	expunge	hadoop dfs -expunge	Empty the Trash
12	get	hadoop dfs -get [-ignorecrc] [-crc] <src> <localdst>
13	getmerge	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
14	ls	hadoop dfs -ls path
15	lsr	hadoop dfs -lsr <args>	Recursive version of ls. Similar to Unix ls -R
16	mkdir
17	moveFromLocal
18	moveToLocal
19	mv
20	put
21	rm
22	rmr	hadoop dfs -rmr [-skipTrash] URI [URI …]
23	setrep	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.
24	stat	hadoop dfs -stat URI [URI …]
25	tail	hadoop dfs -tail [-f] URI	Displays last kilobyte of the file to stdout. -f option can be used as in Unix
26	test	hadoop dfs -test -[ezd] URI	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
27	text	hadoop dfs -text <src>	Takes a source file and outputs the file in text format
28	touchz	hadoop dfs -touchz URI [URI …]	Create a file of zero length.
29	jar	hadoop jar	The hadoop jar command runs a JAR file.
30	fsck	hadoop fsck	HDFS supports the fsck command to check for various inconsistencies. It it is designed for reporting problems with various files, for example, missing blocks for a file or under-replicated blocks.
31	job	hadoop job -list