Linux Quick Reference
SOME USEFUL COMMANDS
File/Directory Basics
ls ------- List files
cp ------- Copy files
mv ------- Rename files
rm ------- Delete files
ln ------- Link files
cd ------- Change directory
pwd ------- Print current directory name
mkdir ------- Create directory
rmdir ------- Delete directory
File Viewing
cat ------- View files
less ------- Page through files
head ------- View file beginning
tail ------- View file ending
nl ------- Number lines
od ------- View binary data
gv ------- View Postscript/PDF files
xdvi ------- View TeX DVI files
File Creation and Editing
emacs ------- Text editor
vim ------- Text editor
umask ------- Set default file protections
soffice ------- Edit Word/Excel/PowerPoint docs
abiword ------- Edit Word documents
gnumeric ------- Edit Excel documents
File Properties
stat ------- Display file attributes
wc ------- Count bytes/words/lines
du ------- Measure disk usage
file ------- Identify file types
touch ------- Change file timestamps
chown ------- Change file owner
chgrp ------- Change file group
chmod ------- Change file protections
chattr ------- Change advanced file attributes
lsattr ------- List advanced file attributes
File Location
find ------- Locate files
slocate ------- Locate files via index
which ------- Locate commands
whereis ------- Locate standard files
File Text Manipulation
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
gzip ------- Compress files (GNU Zip)
compress ------- Compress files (Unix)
bzip2 ------- Compress files (BZip2)
zip ------- Compress files (Windows Zip)
File ------- Comparison
diff ------- Compare files line by line
comm ------- Compare sorted files
cmp ------- Compare files byte by byte
md5sum ------- Compute checksums
Disks and Filesystems
df ------- Show free disk space
mount ------- Make a disk accessible
fsck ------- Check a disk for errors
sync ------- Flush disk caches
Backups and Remote Storage
mt ------- Control a tape drive
dump ------- Back up a disk
restore ------- Restore a dump
tar ------- Read/write tape archives
cdrecord ------- Burn a CD
rsync ------- Mirror a set of files
Printing
lpr ------- Print files
lpq ------- View print queue
lprm ------- Remove print jobs
Spelling Operations
look ------- Look up spelling
aspell ------- Check spelling interactively
spell ------- Check spelling in batch
Processes
ps ------- List all processes
w ------- List users’ processes
uptime ------- View the system load
top ------- Monitor processes
xload ------- Monitor system load
free ------- Display free memory
kill ------- Terminate processes
nice ------- Set process priorities
renice ------- Change process priorities
Scheduling Jobs
sleep ------- Wait for some time
watch ------- Run programs at set intervals
at ------- Schedule a job
crontab ------- Schedule repeated jobs
Hosts
uname ------- Print system information
hostname ------- Print the system’s hostname
ifconfig ------- Set/display network information
host ------- Look up DNS
whois ------- Look up domain registrants
ping ------- Check if host is reachable
traceroute ------- View network path to a host
Networking
ssh ------- Securely log into remote hosts
telnet ------- Log into remote hosts
scp ------- Securely copy files between hosts
sftp ------- Securely copy files between hosts
ftp ------- Copy files between hosts
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
slrn ------- Read Usenet news
gaim ------- Instant messaging/IRC
talk ------- Linux/Unix chat
write ------- Send messages to a terminal
mesg ------- Prohibit talk/write Audio and Video
grip ------- Play CDs and rip MP3s
xmms ------- Play audio files
cdparanoia ------- Rip audio
audacity ------- Edit audio
xcdroast ------- Burn CDs