Hadoop Linux Commands Reference

File/Directory Basics -

Command	→	Description
mkdir	→	Making Directory
cd	→	Change the Directory
clear	→	Clear Commands
pwd	→	Present Working Directory
date	→	Display Date
who am I	→	Display the user name
rm	→	Delete files
ls	→	list files
cp	→	Copy files CP <source-path> <destination-path>
mv	→	Renaming the files mv <source-path> <renaming-path>
ln	→	Link files
rmdir	→	Remove directory

File Viewing Commands -

Command	→	Description
cat	→	View files
less	→	page through files
head	→	view file from beginning (1st 10 records will be displayed)
tail	→	view file ending (last 10 records will be displayed)
nl	→	displays number of lines
od	→	view the binary data
xxd	→	view hexa binary data
gv	→	view post script/pdf files
xdvi	→	view text dvi files

File Creation & Editing -

Command	→	Description
emacs	→	text editor
pico	→	text editor
vi	→	text editor
umask	→	set default file protections
abiword	→	edit word documents
gnumeric	→	edit excel documents

File properties -

Command	→	Description
stat	→	display file attributes
wc	→	count bytes/words/lines
du	→	measure disk usage
file	→	identify file types
touch	→	change the file stamps
chown	→	change the file owner
chgrp	→	change the file group
chmod	→	change file protections
chattr	→	change advance file attributes
lsattr	→	list advance file attributes

File Searching -

Command	→	Description
find	→	locate files
s locate	→	locate files via index
which	→	locate commands
whereis	→	locate standard files

File text manipulation -

Command	→	Description
grep	→	search text for matching lines
cut	→	extract columns
paste	→	append columns
tr	→	translate characters
sort	→	sort lines
uniq	→	locate identical lines
tee	→	copy stdin to a file and to stdout simultaneously

File compression -

Command	→	Description
gzip	→	compress files (GN Zip)
compress	→	compress files(unix)
bzip2	→	compress files(bzip2)
zip	→	compress files(windows zip)

File comparison -

Command	→	Description
diff	→	compare files line by line
comm	→	compare sorted files
cmp	→	compare files byte by byte
md5sum	→	compute check sums

Spelling operations -

Command	→	Description
look	→	lookup spelling
aspell	→	check spelling interactively
spell	→	check spelling in batch

Disk and file systems -

Command	→	Description
df	→	show free space
mount	→	make a disk available
fsck	→	check the disk for errors
sync	→	flush disk caches

Backups and remote storage -

Command	→	Description
mt	→	control a tape device
dump	→	backup a disk
restore	→	restore a dump
tar	→	read/write tape archives
cd record	→	burn a cd
rsync	→	mirror a set of files

Printing -

Command	→	Description
lpr	→	print files
lpq	→	view print queue
lprm	→	remove print jobs

Audio & video -

Command	→	Description
grip	→	play CDs & ripmp3
xmms	→	Play Audi files

Processes -

Command	→	Description
ps	→	List all processes
w	→	List user’s processes
uptime	→	view the system load
top	→	monitor processes
xload	→	monitor system load
free	→	display free memory
kill	→	terminate process
nice	→	Set process priorities
renice	→	change process priorities

Scheduling jobs -

Command	→	Description
sleep	→	wait for some time
watch	→	run programs at set intervals
at	→	schedule a job
crontab	→	Schedule repeated jobs

Hosts -

Command	→	Description
uname	→	print the system information
hostname	→	print the system’s hostname
ifconfig	→	set/display network information
host	→	lookup DNS
who is	→	lookup domain registrants.
Ping	→	check if the host is reachable
Trace route	→	view network path to host

Networking -

Command	→	Description
Ssh	→	securely login into remote hosts
telnet	→	log into remote hosts
scp	→	securely copy files between hosts
sftp	→	securely copy files between hosts
ftp	→	copy the files between shots
evolution	→	GUI email client
mutt	→	text-based email client
mail	→	minimal email client
Mozilla	→	web browser
Lynx	→	text only web browser
Wget	→	retrieve web pages to disk
Srln	→	read UseNet news
Gaim	→	instant messaging/IRC
Talk	→	linux/unix chat
Write	→	send mesgs to terminal
Mesg	→	prohibit talk/write

---