Top 30 linux shell tricks Cheat Sheet by TME520

Run the last command as root	sudo !!
Serve current directory tree at http://$HOSTNAME:8000/	python -m Simple­HTT­PServer
Runs previous command but replacing	echo "­Hello Morld"
	^Morld­^World
	echo "­Hello World"
Rapidly invoke an editor to write a long command	[ctrl+x e]
Place the argument of the most recent command on the shell	'ALT+.' or '<E­SC> .'
Salvage a borked terminal	reset
List currently mounted filesystems in nice layout	mount | column -t
Get your external IP address	curl ifconf­ig.me
Execute a command at a given time	echo "ls -l" | at midnight
Output your microphone to a remote computer's speaker	dd if=/de­v/dsp | ssh -c arcfour -C userna­me@host dd of=/de­v/dsp
Type partial command, check something, resume typing	vi /etc/ssh/ [ctrl+u]
	ls -lisa /etc/ssh/
	[ctrl+y] vi /etc/s­sh/­ssh­_config
Mount folder/filesystem through SSH	sshfs name@s­erv­er:­/pa­th/­to/­folder /path/­to/­mou­nt/­point
Mount a temporary ram partition	mount -t tmpfs tmpfs /mnt -o size=1024m
Download an entire website	wget --rand­om-wait -r -p -e robots=off -U mozilla http:/­/ww­w.e­xam­ple.com
Clear the terminal screen	[ctrl+l]
Compare a remote file with a local file	ssh user@host cat /path/­to/­rem­otefile | diff /path/­to/­loc­alfile -
Update twitter via curl	curl -u user:pass -d status­="Tw­eeting from the shell" http:/­/tw­itt­er.c­om­/st­atu­ses­/up­dat­e.xml`
SSH connection through host in the middle	ssh -t reacha­ble­_host ssh unreac­hab­le_host
Close shell keeping all subprocess running	disown -a && exit
Make 'less' behave like 'tail -f'	less +F somelo­gfile
Put a console clock in top right corner	while sleep 1;do tput sc;tput cup 0 $(($(tput cols)-­29)­);d­ate­;tput rc;done &
Shutdown a Windows machine from Linux	net rpc shutdown -I ipAddr­ess­OfW­ind­owsPC -U userna­me%­pas­sword
List of commands you use most often	history | awk '{a[$2­]++­}EN­D{for(i in a){print a[i] " " i}}' | sort -rn | head
32 bits or 64 bits?	getconf LONG_BIT
Set audible alarm when an IP address comes online	ping -i 60 -a IP_address
Reboot machine when everything is hanging	<al­t> + <print screen/sys rq> + <R> - <S> - <E> - <I> - <U> - <B>
Simulate typing	echo "You can simulate on-screen typing just like in the movies­" | pv -qL 10
Quickly rename a file	mv filena­me.{­ol­d,new}
Escape any command aliases	\[command]
Delete all files in a folder that don't match a certain file extension	rm !(.foo|.bar|*.baz)

Reuse all parameter of the previous command line	!*
Sharing file through http 80 port	nc -v -l 80 < file.ext
Display a block of text with AWK	awk '/star­t_p­att­ern­/,/­sto­p_p­att­ern/' file.txt
Kills a process that is locking a file	fuser -k filename
Display all current terminal settings	stty -a
Type a string, hit [ctrl+d] and see the ASCII codes	od -cx