Linux Commands – CyberNing

Command	Description
cat > file	places standard input into file
cd	change to the home directory
cd directory	change directory to directory
cp file1 file2	copy file1 to file2
head file	output the first 10 lines of file
ln -s file link	create symbolic link to file
ls	directory listing
ls -al	formatted directory listing of files (including hidden ones)
mkdir dir	create a directory called dir
more file	output the contents of file
mv file1 file2	rename or move file1 to file2. If file2 is an existing directory, moves file1 into directory file2
pwd	show current directory
rm file	delete file
rm -f file	force remove file
rm -r dir	delete directory dir
rm -rf dir	force remove directory dir — USE WITH EXTREME CAUTION
scp -r [email protected]:directory1 [email protected]:directory2	recursively copies files between servers
tail file	output the last 10 lines of file
tail -f file	output the last 10 lines of file as it grows, starting with the last 10 lines
touch file	create or update file

The owner, group and world permissions for files and directories can be changes using the chmod command

Examples

Command	Description
chmod 777 file	change permissions of file to read, write and execute for all
chmod 755 file	change permissions of file to rwx for owner, rx for group and world

Command	Description
grep pattern files	search for pattern in files
grep -r pattern dir	search recursively for pattern in dir
locate file	find all instances of file

Command	Description
dig domain	get DNS information for domain
dig any @nameserver domain	get DNS information for domain held by nameserver
dig mx domain	get DNS mail information for domain
ping host/domain	ping host or domain and output results
whois domain	get whois information for a domain

Command	Description
ssh [email protected]	connect to host as user
ssh -p port [email protected]	connect to host on port port as user
ssh -copy -d [email protected]	add your key to host for user to enable a keyed or passwordless login

Command	Description
tar cf file.tar files	create a tar named file.tar containing files
tar xf file.tar files	extract the files from file.tar
tar czf file.tar.gz files	create a tar with Gzip compression
tar xzf file.tar.gz files	extract a tar using Gzip
tar cjf file.tar.bz2 files	create a tar with Bzip2 compression
tar xjf file.tar.bz2 files	extract a tar using Bzip2
gzip file	compresses file and renames it file.gz
gzip -d file.gz	decompresses file.gz back to file

Command	Description
Ctrl+C	halts the current command
Ctrl+Z	stops the current command, resume with fg in the foreground or bg in the background
Ctrl+D	log out of the current session, similar to exit
Ctrl+W	erases one word in the current line
Ctrl+U	erases the whole line
R	type to bring up a recent command
!!	repeats the last command
exit	log out of the current session

Command	Description
uptime	show current uptime
w	show who is online
whoami	show who you are logged in as
finger user	display information about user
uname -a	show kernel information
cat /proc/cpuinfo	show CPU information
cat /proc/meminfo	show memory information
man command	show manual for command
df	show disk usage
du	show directory space usage
free	show memory and swap usage
whereis app	show possible locations of app
which app	show which app will be run by default
whois	shows the identity of a domain or IP address
locate	find file or directory

These commands only work for domains still on Begis

Command	Description
dom domain	display web and mail server information for domain
dom domain -f	display hosting features for domain
domm domain	display mailbox information for domain
paccount domain	tools for managing quota/FrontPage/PHP/SSL/MySQL etc
sysadd server masteraccount masteraccountpassword	adds domain to a server
sysclone server domain masteraccount masteraccountpassword	copies a domain from one Debian server to another
updateWhere domain newinternalservername	notifies all of Hostway’s systems where the customer is now located