Posix Cheat Sheet (DRAFT) by spartan782

Command	Descri­ption
man <co­mma­nd>	read the manual
apropos	search "­wha­tis­" database
<co­mma­nd> -h	help for specific command
<command> --help	help for specific command
find	find files
locate	find files
whereis	searches man pages and source files for a program
which	Search the user's $path for a program file

Command	Descri­ption
| (pipe)	passes output from one command to another
grep	search file(s) for lines that match a given pattern
egrep	search file(s) for lines that match an extended exp
zgrep	search compressed file(s) for lines that match pattern
sort	sort text files
wc	print byte, word, and line counts
cut	divide a file into several parts
uniq	uniquify files
sed	Stream manipu­lation tool
awk	Progra­mming Language and Text processor

Command	Descri­ption
whoami	print the current user id and name
hostname	print or set system name
date	display or change the date & time
uptime	show time since last reboot / start
users	list users currently logged in
finger	display info about user
who	print all usernames currently logged in
uname	print system inform­ation
df	show disk usage
du	show directory space usage
free	show memory and swap usage

Alias	Descri­ption
. (period)	"­her­e" or current working directory
.. (double period)	up one level from current directory
~	current user's home directory
-	last working directory

Command	Descri­ption
pwd	displays current working dir
ls	list contents
tree	displays dir contents in visual tree
cd	change directory

Command	Descri­ption
id	print user and group id's
useradd	create new user account
passwd	modify a user password
usermod	modify user account
userdel	delete a user account
groups	print group names a user is in
groupadd	add a user security group
groupmod	modify a group
groupdel	delete a group
chown	change file owner and group
chmod	change access permis­sions

Command	Descri­ption
cat	concat­enate and print (display) the content of files
less	display output one screen at a time
tail	output the last part of file (-f to follow)
touch	create a new (empty) file or change file timestamps
nano	create or edit file in nano editor
vim	create / edit file in vim editor
rm	remove file
mkdir	create dir
rmdir	remove dir
ln	create a hard link to file
ln -s	create a symbolic link to a file

Shortcut	Descri­ption
Up/Down Arrow	access previous command history
ctrl + A	move cursor to start of line
ctrl + E	move cursor to end of line
ctrl + U	delete left of cursor
ctrl + K	delete right of cursor
ctrl + W	delete word on left
ctrl + <	jump to left by argument
ctrl + >	jump to right by argument
<TA­B>	completes filename or command
ctrl + R	reverse search history
!!	repeat last command
history	display contents on .bash_­history
!###	rerun specific history entry

ip a	display routing, devices and tunnels
ss	socket statistics (show open / listening ports)
ping	icmp to test connec­tivity
traceroute	trace route to host
dig	DNS lookup
ssh	Secure Shell client (remote login program)
scp	secure copy (remote file copy)
tcpdump	dump traffic on a network
nmtui	textual interface to configure networking

Command	Descri­ption
w	who is logged on
ps	process status
lsof	list open files
kill	kill process
iostat	report CPU and i/o statistics
top	list processes running on the system
htop	intera­ctive process viewer
sudo halt	shutdown system
sudo reboot	reboot system
systemctl	Tool used to interact with Systemd