# commandlinefu.com by David Winterbottom

# Run the last command as root
sudo !!

# Serve current directory tree at http://$HOSTNAME:8000/
python -m SimpleHTTPServer

# change to the previous working directory
cd -

# Runs previous command but replacing
^foo^bar

# mtr, better than traceroute and ping combined
mtr google.com

# Rapidly invoke an editor to write a long, complex, or tricky command
ctrl-x e

# Execute a command without saving it in the history
<space>command

# Empty a file
> file.txt

# Salvage a borked terminal
reset

# Capture video of a linux desktop
ffmpeg -f x11grab -s wxga -r 25 -i :0.0 -sameq /tmp/out.mpg

# Place the argument of the most recent command on the shell
'ALT+.' or '<ESC> .'

# currently mounted filesystems in nice layout
mount | column -t

# Query Wikipedia via console over DNS
dig +short txt <keyword>.wp.dg.cx

# Execute a command at a given time
echo "ls -l" | at midnight

# start a tunnel from some machine's port 80 to your local post 2001
ssh -N -L2001:localhost:80 somemachine

# Lists all listening ports together with the PID of the associated process
netstat -tlnp

# Quick access to the ascii table.
man ascii

# Runs previous command replacing foo by bar every time that foo appears
!!:gs/foo/bar

# output your microphone to a remote computer's speaker
dd if=/dev/dsp | ssh -c arcfour -C username@host dd of=/dev/dsp

# Get your external IP address
curl ifconfig.me

# Mount a temporary ram partition
mount -t tmpfs tmpfs /mnt -o size=1024m

# Mount folder/filesystem through SSH
sshfs name@server:/path/to/folder /path/to/mount/point

# Update twitter via curl
curl -u user:pass -d status="Tweeting from the shell" http://twitter.com/statuses/update.xml

# Compare a remote file with a local file
ssh user@host cat /path/to/remotefile | diff /path/to/localfile -

# Download an entire website
wget --random-wait -r -p -e robots=off -U mozilla http://www.example.com

# commandlinefu.com by David Winterbottom

# Clear the terminal screen
ctrl-l

# Jump to a directory, execute a command and jump back to current dir
(cd /tmp && ls)

# List the size (in human readable form) of all sub folders from the current location
du -h --max-depth=1

# type partial command, kill this command, check something you forgot, yank the command, resume typing.
<ctrl+u> [...] <ctrl+y>

# A very simple and useful stopwatch
time read (ctrl-d to stop)

# SSH connection through host in the middle
ssh -t reachable_host ssh unreachable_host

# Shutdown a Windows machine from Linux
net rpc shutdown -I ipAddressOfWindowsPC -U username%password

# Make 'less' behave like 'tail -f'.
less +F somelogfile

# Watch Star Wars via telnet
telnet towel.blinkenlights.nl

# Check your unread Gmail from the command line
curl -u username --silent "https://mail.google.com/mail/feed/atom" | perl -ne 'print "\t" if /<name>/; print "$2\n" if /<(title|name)>(.*)<\/\1>/;'

# Simulate typing
echo "You can simulate on-screen typing just like in the movies" | pv -qL 10

# 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>

# Close shell keeping all subprocess running
disown -a && exit

# List of commands you use most often
history | awk '{a[$2]++}END{for(i in a){print a[i] " " i}}' | sort -rn | head

# Display the top ten running processes - sorted by memory usage
ps aux | sort -nk +4 | tail

# 32 bits or 64 bits?
getconf LONG_BIT

# Display a block of text with AWK
awk '/start_pattern/,/stop_pattern/' file.txt

# Set CDPATH to ease navigation
CDPATH=:..:~:~/projects

# Push your present working directory to a stack that you can pop later
pushd /tmp

# Put a console clock in top right corner
while sleep 1;do tput sc;tput cup 0 $(($(tput cols)-29));date;tput rc;done &

# Watch Network Service Activity in Real-time
lsof -i

# Backticks are evil
echo "The date is: $(date +%D)"

# Create a script of the last executed command
echo "!!" > foo.sh

# diff two unsorted files without creating temporary files
diff <(sort file1) <(sort file2)

# commandlinefu.com by David Winterbottom

# Sharing file through http 80 port
nc -v -l 80 < file.ext

# escape any command aliases
\[command]

# Reuse all parameter of the previous command line
!*

# Easy and fast access to often executed commands that are very long and complex.
some_very_long_and_complex_command # label

# Show apps that use internet connection at the moment. (Multi-Language)
lsof -P -i -n

# quickly rename a file
mv filename.{old,new}

# python smtp server
python -m smtpd -n -c DebuggingServer localhost:1025

# Delete all files in a folder that don't match a certain file extension
rm !(*.foo|*.bar|*.baz)

# Google Translate
translate(){ wget -qO- "http://ajax.googleapis.com/ajax/services/language/translate?v=1.0&q=$1&langpair=$2|${3:-en}" | sed 's/.*"translatedText":"\([^"]*\)".*}/\1\n/'; }

# save command output to image
ifconfig | convert label:@- ip.png

# Remove duplicate entries in a file without sorting.
awk '!x[$0]++' <file>

# Extract tarball from internet without local saving
wget -qO - "http://www.tarball.com/tarball.gz" | tar zxvf -

# Kills a process that is locking a file.
fuser -k filename

# Matrix Style
tr -c "[:digit:]" " " < /dev/urandom | dd cbs=$COLUMNS conv=unblock | GREP_COLOR="1;32" grep --color "[^ ]"

# Rip audio from a video file.
mplayer -ao pcm -vo null -vc dummy -dumpaudio -dumpfile <output-file> <input-file>

# Display which distro is installed
cat /etc/issue

# Find the process you are looking for minus the grepped one
ps aux | grep [p]rocess-name

# Insert the last command without the last argument (bash)
!:-

# Inserts the results of an autocompletion in the command line
ESC *

# Add Password Protection to a file your editing in vim.
vim -x <FILENAME>

# Stream YouTube URL directly to mplayer.
i="8uyxVmdaJ-w";mplayer -fs $(curl -s "http://www.youtube.com/get_video_info?&video_id=$i" | echo -e $(sed 's/%/\\x/g;s/.*\(v[0-9]\.lscache.*\)/http:\/\/\1/g') | grep -oP '^[^|,]*')

# Copy your SSH public key on a remote machine for passwordless login - the easy way
ssh-copy-id username@hostname

# A fun thing to do with ram is actually open it up and take a peek. This command will show you all the string (plain text) values in ram
sudo dd if=/dev/mem | cat | strings

# Define a quick calculator function
? () { echo "$*" | bc -l; }

# Show File System Hierarchy
man hier

# commandlinefu.com by David Winterbottom

# Easily search running processes (alias).
alias 'ps?'='ps ax | grep '

# Create a CD/DVD ISO image from disk.
readom dev=/dev/scd0 f=/path/to/image.iso

# Graphical tree of sub-directories
ls -R | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' -e 's/^/   /' -e 's/-/|/'

# Monitor progress of a command
pv access.log | gzip > access.log.gz

# Print all the lines between 10 and 20 of a file
sed -n '10,20p' <filename>

# Make directory including intermediate directories
mkdir -p a/long/directory/path

# Multiple variable assignments from command output in BASH
read day month year <<< $(date +'%d %m %y')

# intercept stdout/stderr of another process
strace -ff -e trace=write -e write=1,2 -p SOME_PID

# Job Control
^Z $bg $disown

# Show apps that use internet connection at the moment. (Multi-Language)
ss -p

# Copy a file using pv and watch its progress
pv sourcefile > destfile

# Send pop-up notifications on Gnome
notify-send ["<title>"] "<body>"

# Edit a file on a remote host using vim
vim scp://username@host//path/to/somefile

# Create a pdf version of a manpage
man -t manpage | ps2pdf - filename.pdf

# replace spaces in filenames with underscores
rename 'y/ /_/' *

# Generate a random password 30 characters long
strings /dev/urandom | grep -o '[[:alnum:]]' | head -n 30 | tr -d '\n'; echo

# Find Duplicate Files (based on size first, then MD5 hash)
find -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate

# Check your unread Gmail from the command line
curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | sed -n "s/<title>\(.*\)<\/title.*name>\(.*\)<\/name>.*/\2 - \1/p"

# Graph # of connections for each hosts.
netstat -an | grep ESTABLISHED | awk '{print $5}' | awk -F: '{print $1}' | sort | uniq -c | awk '{ printf("%s\t%s\t",$2,$1) ; for (i = 0; i < $1; i++) {printf("*")}; print "" }'

# Convert seconds to human-readable format
date -d@1234567890

# Remove all but one specific file
rm -f !(survivior.txt)

# return external ip
curl icanhazip.com

# Display a cool clock on your terminal
watch -t -n1 "date +%T|figlet"

# Monitor the queries being run by MySQL
watch -n 1 mysqladmin --user=<user> --password=<password> processlist

# Mount a .iso file in UNIX/Linux
mount /path/to/file.iso /mnt/cdrom -oloop

# commandlinefu.com by David Winterbottom

# Get the 10 biggest files/folders for the current direcotry
du -s * | sort -n | tail

# Record a screencast and convert it to an mpeg
ffmpeg -f x11grab -r 25 -s 800x600 -i :0.0 /tmp/outputFile.mpg

# Search commandlinefu.com from the command line using the API
cmdfu(){ curl "http://www.commandlinefu.com/commands/matching/$@/$(echo -n $@ | openssl base64)/plaintext"; }

# Open Finder from the current Terminal location
open .

# Processor / memory bandwidthd? in GB/s
dd if=/dev/zero of=/dev/null bs=1M count=32768

# mkdir & cd into it as single command
mkdir /home/foo/doc/bar && cd $_

# Remove a line in a text file. Useful to fix
ssh-keygen -R <the_offending_host>

# Attach screen over ssh
ssh -t remote_host screen -r

# Share a terminal screen with others
% screen -r someuser/

# Create a persistent connection to a machine
ssh -MNf <user>@<host>

# Copy your ssh public key to a server from a machine that doesn't have ssh-copy-id
cat ~/.ssh/id_rsa.pub | ssh user@machine "mkdir ~/.ssh; cat >> ~/.ssh/authorized_keys"

# Makes the permissions of file2 the same as file1
chmod --reference file1 file2

# git remove files which have been deleted
git add -u

# directly ssh to host B that is only accessible through host A
ssh -t hostA ssh hostB

# (Debian/Ubuntu) Discover what package a file belongs to
dpkg -S /usr/bin/ls

# List all bash shortcuts
bind -P

# Draw kernel module dependancy graph.
lsmod | perl -e 'print "digraph \"lsmod\" {";<>;while(<>){@_=split/\s+/; print "\"$_[0]\" -> \"$_\"\n" for split/,/,$_[3]}print "}"' | dot -Tpng | display -

# RTFM function
rtfm() { help $@ || man $@ || $BROWSER "http://www.google.com/search?q=$@"; }

# Show numerical values for each of the 256 colors in bash
for code in {0..255}; do echo -e "\e[38;05;${code}m $code: Test"; done

# To print a specific line from a file
sed -n 5p <file>

# Run a command only when load average is below a certain threshold
echo "rm -rf /unwanted-but-large/folder" | batch

# Download Youtube video with wget!
wget http://www.youtube.com/watch?v=dQw4w9WgXcQ -qO- | sed -n "/fmt_url_map/{s/[\'\"\|]/\n/g;p}" | sed -n '/^fmt_url_map/,/videoplayback/p' | sed -e :a -e '$q;N;5,$D;ba' | tr -d '\n' | sed -e 's/\(.*\),\(.\)\{1,3\}/\1/' | wget -i - -O surprise.flv

# Broadcast your shell thru ports 5000, 5001, 5002 ...
script -qf | tee >(nc -kl 5000) >(nc -kl 5001) >(nc -kl 5002)

# Eavesdrop on your system
diff <(lsof -p 1234) <(sleep 10; lsof -p 1234)

# Remove security limitations from PDF documents using ghostscript
gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=OUTPUT.pdf -c .setpdfwrite -f INPUT.pdf

# commandlinefu.com by David Winterbottom

# Run a file system check on your next boot.
sudo touch /forcefsck

# Release memory used by the Linux kernel on caches
free && sync && echo 3 > /proc/sys/vm/drop_caches && free

# Remove all files previously extracted from a tar(.gz) file.
tar -tf <file.tar.gz> | xargs rm -r

# using `!#$' to referance backward-word
cp /work/host/phone/ui/main.cpp !#$:s/host/target

# Binary Clock
watch -n 1 'echo "obase=2;`date +%s`" | bc'

# List only the directories
ls -d */

# Download all images from a site
wget -r -l1 --no-parent -nH -nd -P/tmp -A".gif,.jpg" http://example.com/images

# Duplicate installed packages from one machine to the other (RPM-based systems)
ssh root@remote.host "rpm -qa" | xargs yum -y install

# Start COMMAND, and kill it if still running after 5 seconds
timeout 5s COMMAND

# Use tee to process a pipe with two or more processes
echo "tee can split a pipe in two"|tee >(rev) >(tr ' ' '_')

# Edit a google doc with vim
google docs edit --title "To-Do List" --editor vim

# Backup all MySQL Databases to individual files
for I in $(mysql -e 'show databases' -s --skip-column-names); do mysqldump $I | gzip > "$I.sql.gz"; done

# Port Knocking!
knock <host> 3000 4000 5000 && ssh -p <port> user@host && knock <host> 5000 4000 3000

# Show a 4-way scrollable process tree with full details.
ps awwfux | less -S

# which program is this port belongs to ?
lsof -i tcp:80

# Sort the size usage of a directory tree by gigabytes, kilobytes, megabytes, then bytes.
du -b --max-depth 1 | sort -nr | perl -pe 's{([0-9]+)}{sprintf "%.1f%s", $1>=2**30? ($1/2**30, "G"): $1>=2**20? ($1/2**20, "M"): $1>=2**10? ($1/2**10, "K"): ($1, "")}e'

# Google text-to-speech in mp3 format
wget -q -U Mozilla -O output.mp3 "http://translate.google.com/translate_tts?ie=UTF-8&tl=en&q=hello+world

# What is my public IP-address?
curl ifconfig.me

# Search recursively to find a word or phrase in certain file types, such as C code
find . -name "*.[ch]" -exec grep -i -H "search pharse" {} \;

# Bring the word under the cursor on the :ex line in Vim
:<C-R><C-W>

# Block known dirty hosts from reaching your machine
wget -qO - http://infiltrated.net/blacklisted|awk '!/#|[a-z]/&&/./{print "iptables -A INPUT -s "$1" -j DROP"}'

# Synchronize date and time with a server over ssh
date --set="$(ssh user@server date)"

# Recursively remove all empty directories
find . -type d -empty -delete

# Add timestamp to history
export HISTTIMEFORMAT="%F %T "

# Rapidly invoke an editor to write a long, complex, or tricky command
fc

# commandlinefu.com by David Winterbottom

# Find out how much data is waiting to be written to disk
grep ^Dirty /proc/meminfo

# Remove a line in a text file. Useful to fix "ssh host key change" warnings
sed -i 8d ~/.ssh/known_hosts

# Search for a <pattern> string inside all files in the current directory
grep -RnisI <pattern> *

# Colorized grep in less
grep --color=always | less -R

# check site ssl certificate dates
echo | openssl s_client -connect www.google.com:443 2>/dev/null |openssl x509 -dates -noout

# Create a quick back-up copy of a file
cp file.txt{,.bak}

# Convert Youtube videos to MP3
youtube-dl -t --extract-audio --audio-format mp3 YOUTUBE_URL_HERE

# Exclude multiple columns using AWK
awk '{$1=$3=""}1' file

# Get the IP of the host your coming from when logged in remotely
echo ${SSH_CLIENT%% *}

# ls not pattern
ls !(*.gz)

# Show apps that use internet connection at the moment.
lsof -P -i -n | cut -f 1 -d " "| uniq | tail -n +2

# Compare two directory trees.
diff <(cd dir1 && find | sort) <(cd dir2 && find | sort)

# exit without saving history
kill -9 $$

# Remind yourself to leave in 15 minutes
leave +15

# make directory tree
mkdir -p work/{d1,d2}/{src,bin,bak}

# Control ssh connection
[enter]~?

# pretend to be busy in office to enjoy a cup of coffee
cat /dev/urandom | hexdump -C | grep "ca fe"

# run complex remote shell cmds over ssh, without escaping quotes
ssh host -l user $(<cmd.txt)

# GREP a PDF file.
pdftotext [file] - | grep 'YourPattern'

# Exclude .svn, .git and other VCS junk for a pristine tarball
tar --exclude-vcs -cf src.tar src/

# delete a line from your shell history
history -d

# Recursively change permissions on files, leave directories alone.
find ./ -type f -exec chmod 644 {} \;

# Convert PDF to JPG
for file in `ls *.pdf`; do convert -verbose -colorspace RGB -resize 800 -interlace none -density 300 -quality 80 $file `echo $file | sed 's/\.pdf$/\.jpg/'`; done

# Prettify an XML file
tidy -xml -i -m [file]

# Quick access to ASCII code of a key
showkey -a

# commandlinefu.com by David Winterbottom

# find files in a date range
find . -type f -newermt "2010-01-01" ! -newermt "2010-06-01"

# notify yourself when a long-running command which has ALREADY STARTED is finished
<ctrl+z> fg; notify_me

# easily find megabyte eating files or directories
alias dush="du -sm *|sort -n|tail"

# prints line numbers
nl

# A robust, modular log coloriser
ccze

# Remove blank lines from a file using grep and save output to new file
grep . filename > newfilename

# Create a directory and change into it at the same time
md () { mkdir -p "$@" && cd "$@"; }

# Save your sessions in vim to resume later
:mksession! <filename>

# How to establish a remote Gnu screen session that you can re-connect to
ssh -t user@some.domain.com /usr/bin/screen -xRR

# Take screenshot through SSH
DISPLAY=:0.0 import -window root /tmp/shot.png

# Lists all listening ports together with the PID of the associated process
lsof -Pan -i tcp -i udp

# Opens vi/vim at pattern in file
vi +/pattern [file]

# Alias HEAD for automatic smart output
alias head='head -n $((${LINES:-`tput lines 2>/dev/null||echo -n 12`} - 2))'

# Create colorized html file from Vim or Vimdiff
:TOhtml

# Colorful man
apt-get install most && update-alternatives --set pager /usr/bin/most

# Pipe stdout and stderr, etc., to separate commands
some_command > >(/bin/cmd_for_stdout) 2> >(/bin/cmd_for_stderr)

# Go to parent directory of filename edited in last command
cd !$:h

# Diff on two variables
diff <(echo "$a") <(echo "$b")

# Draw a Sierpinski triangle
perl -e 'print "P1\n256 256\n", map {$_&($_>>8)?1:0} (0..0xffff)' | display

# Create a nifty overview of the hardware in your computer
lshw -html > hardware.html

# Manually Pause/Unpause Firefox Process with POSIX-Signals
killall -STOP -m firefox

# Gets a random Futurama quote from /.
curl -Is slashdot.org | egrep '^X-(F|B|L)' | cut -d \- -f 2

# Use lynx to run repeating website actions
lynx -accept_all_cookies -cmd_script=/your/keystroke-file

# Intercept, monitor and manipulate a TCP connection.
mkfifo /tmp/fifo; cat /tmp/fifo | nc -l -p 1234 | tee -a to.log | nc machine port | tee -a from.log > /tmp/fifo

# Display a list of committers sorted by the frequency of commits
svn log -q|grep "|"|awk "{print \$3}"|sort|uniq -c|sort -nr

# commandlinefu.com by David Winterbottom

# Copy a MySQL Database to a new Server via SSH with one command
mysqldump --add-drop-table --extended-insert --force --log-error=error.log -uUSER -pPASS OLD_DB_NAME | ssh -C user@newhost "mysql -uUSER -pPASS NEW_DB_NAME"

# Fast, built-in pipe-based data sink
<COMMAND> |:

# Use file(1) to view device information
file -s /dev/sd*

# Find usb device
diff <(lsusb) <(sleep 3s && lsusb)

# Bind a key with a command
bind -x '"\C-l":ls -l'

# copy working directory and compress it on-the-fly while showing progress
tar -cf - . | pv -s $(du -sb . | awk '{print $1}') | gzip > out.tgz

# analyze traffic remotely over ssh w/ wireshark
ssh root@server.com 'tshark -f "port !22" -w -' | wireshark -k -i -

# View the newest xkcd comic.
xkcd(){ wget -qO- http://xkcd.com/|tee >(feh $(grep -Po '(?<=")http://imgs[^/]+/comics/[^"]+\.\w{3}'))|grep -Po '(?<=(\w{3})" title=").*(?=" alt)';}

# convert unixtime to human-readable
date -d @1234567890

# Schedule a script or command in x num hours, silently run in the background even if logged out
( ( sleep 2h; your-command your-args ) & )

# recursive search and replace old with new string, inside files
$ grep -rl oldstring . |xargs sed -i -e 's/oldstring/newstring/'

# Find files that have been modified on your system in the past 60 minutes
sudo find / -mmin 60 -type f

# find geographical location of an ip address
lynx -dump http://www.ip-adress.com/ip_tracer/?QRY=$1|grep address|egrep 'city|state|country'|awk '{print $3,$4,$5,$6,$7,$8}'|sed 's\ip address flag \\'|sed 's\My\\'

# read manpage of a unix command as pdf in preview (Os X)
man -t UNIX_COMMAND | open -f -a preview

# Speed up launch of firefox
find ~ -name '*.sqlite' -exec sqlite3 '{}' 'VACUUM;' \;

# List the number and type of active network connections
netstat -ant | awk '{print $NF}' | grep -v '[a-z]' | sort | uniq -c

# format txt as table not joining empty columns
column -tns: /etc/passwd

# Bind a key with a command
bind '"\C-l":"ls -l\n"'

# prevent accidents while using wildcards
rm *.txt <TAB> <TAB>

# Random Number Between 1 And X
echo $[RANDOM%X+1]

# live ssh network throughput test
yes | pv | ssh $host "cat > /dev/null"

# Press Any Key to Continue
read -sn 1 -p "Press any key to continue..."

# backup all your commandlinefu.com favourites to a plaintext file
clfavs(){ URL="http://www.commandlinefu.com";wget -O - --save-cookies c --post-data "username=$1&password=$2&submit=Let+me+in" $URL/users/signin;for i in `seq 0 25 $3`;do wget -O - --load-cookies c $URL/commands/favourites/plaintext/$i >>$4;done;rm -f c;}

# send echo to socket network
echo "foo" > /dev/tcp/192.168.1.2/25

# Perform a branching conditional
true && { echo success;} || { echo failed; }

# commandlinefu.com by David Winterbottom

# Resume scp of a big file
rsync --partial --progress --rsh=ssh  $file_source $user@$host:$destination_file

# shut of the screen.
xset dpms force standby

# Create a single-use TCP (or UDP) proxy
nc -l -p 2000 -c "nc example.org 3000"

# runs a bash script in debugging mode
bash -x ./post_to_commandlinefu.sh

# Instead of writing a multiline if/then/else/fi construct you can do that by one line
[[ test_condition ]] && if_true_do_this || otherwise_do_that

# Use tee + process substitution to split STDOUT to multiple commands
some_command | tee >(command1) >(command2) >(command3) ... | command4

# Retry the previous command until it exits successfully
until !!; do :; done

# Shell recorder with replay
script -t /tmp/mylog.out 2>/tmp/mylog.time; <do your work>; <CTRL-D>; scriptreplay /tmp/mylog.time /tmp/mylog.out

# A child process which survives the parent's death (for sure)
( command & )

# find all file larger than 500M
find / -type f -size +500M

# exclude a column with cut
cut -f5 --complement

# Recover a deleted file
grep -a -B 25 -A 100 'some string in the file' /dev/sda1 > results.txt

# April Fools' Day Prank
PROMPT_COMMAND='if [ $RANDOM -le 3200 ]; then printf "\0337\033[%d;%dH\033[4%dm \033[m\0338" $((RANDOM%LINES+1)) $((RANDOM%COLUMNS+1)) $((RANDOM%8)); fi'

# Listen to BBC Radio from the command line.
bbcradio() { local s PS3="Select a station: ";select s in 1 1x 2 3 4 5 6 7 "Asian Network an" "Nations & Local lcl";do break;done;s=($s);mplayer -playlist "http://www.bbc.co.uk/radio/listen/live/r"${s[@]: -1}".asx";}

# Monitor bandwidth by pid
nethogs -p eth0

# throttle bandwidth with cstream
tar -cj /backup | cstream -t 777k | ssh host 'tar -xj -C /backup'

# Run a long job and notify me when it's finished
./my-really-long-job.sh && notify-send "Job finished"

# List all files opened by a particular command
lsof -c dhcpd

# Tell local Debian machine to install packages used by remote Debian machine
ssh remotehost 'dpkg --get-selections' | dpkg --set-selections && dselect install

# GRUB2: set Super Mario as startup tune
echo "GRUB_INIT_TUNE=\"1000 334 1 334 1 0 1 334 1 0 1 261 1 334 1 0 1 392 2 0 4 196 2\"" | sudo tee -a /etc/default/grub > /dev/null && sudo update-grub

# Diff remote webpages using wget
diff <(wget -q -O - URL1) <(wget -q -O - URL2)

# Close a hanging ssh session
~.

# List alive hosts in specific subnet
nmap -sP 192.168.1.0/24

# intersection between two files
grep -Fx -f file1 file2

# processes per user counter
ps hax -o user | sort | uniq -c

# commandlinefu.com by David Winterbottom

# Create an audio test CD of sine waves from 1 to 99 Hz
(echo CD_DA; for f in {01..99}; do echo "$f Hz">&2; sox -nt cdda -r44100 -c2 $f.cdda synth 30 sine $f; echo TRACK AUDIO; echo FILE \"$f.cdda\" 0; done) > cdrdao.toc && cdrdao write cdrdao.toc && rm ??.cdda cdrdao.toc

# Show current working directory of a process
pwdx pid

# Quickly (soft-)reboot skipping hardware checks
/sbin/kexec -l /boot/$KERNEL --append="$KERNELPARAMTERS" --initrd=/boot/$INITRD; sync; /sbin/kexec -e

# Nicely display permissions in octal format with filename
stat -c '%A %a %n' *

# Brute force discover
sudo zcat /var/log/auth.log.*.gz | awk '/Failed password/&&!/for invalid user/{a[$9]++}/Failed password for invalid user/{a["*" $11]++}END{for (i in a) printf "%6s\t%s\n", a[i], i|"sort -n"}'

# convert uppercase files to lowercase files
rename 'y/A-Z/a-z/' *

# Check if system is 32bit or 64bit
getconf LONG_BIT

# Limit the cpu usage of a process
sudo cpulimit -p pid -l 50

# Convert seconds into minutes and seconds
bc <<< 'obase=60;299'

# Repoint an existing symlink to a new location
ln -nsf <TARGET> <LINK>

# send a circular
wall <<< "Broadcast This"

# The BOFH Excuse Server
telnet towel.blinkenlights.nl 666

# List files with quotes around each filename
ls -Q

# See udev at work
udevadm monitor

# Get your outgoing IP address
dig +short myip.opendns.com @resolver1.opendns.com

# Makes you look busy
alias busy='my_file=$(find /usr/include -type f | sort -R | head -n 1); my_len=$(wc -l $my_file | awk "{print $1}"); let "r = $RANDOM % $my_len" 2>/dev/null; vim +$r $my_file'

# Insert  the  last  argument  of  the previous command
<ESC> .

# Duplicate several drives concurrently
dd if=/dev/sda | tee >(dd of=/dev/sdb) | dd of=/dev/sdc

# Make sure a script is run in a terminal.
[ -t 0 ] || exit 1

# Get your external IP address
curl ip.appspot.com

# use vim to get colorful diff output
svn diff | view -

# A fun thing to do with ram is actually open it up and take a peek. This command will show you all the string (plain text) values in ram
sudo strings /dev/mem

# find files containing text
grep -lir "some text" *

# Quickly graph a list of numbers
gnuplot -persist <(echo "plot '<(sort -n listOfNumbers.txt)' with lines")

# Analyse an Apache access log for the most common IP addresses
tail -10000 access_log | awk '{print $1}' | sort | uniq -c | sort -n | tail

# commandlinefu.com by David Winterbottom

# prevent large files from being cached in memory (backups!)
nocache <I/O-heavy-command>

# Print diagram of user/groups
awk 'BEGIN{FS=":"; print "digraph{"}{split($4, a, ","); for (i in a) printf "\"%s\" [shape=box]\n\"%s\" -> \"%s\"\n", $1, a[i], $1}END{print "}"}' /etc/group|display

# Create strong, but easy to remember password
read -s pass; echo $pass | md5sum | base64 | cut -c -16

# Generate an XKCD #936 style 4 word password
shuf -n4 /usr/share/dict/words | tr -d '\n'

# Python version 3: Serve current directory tree at http://$HOSTNAME:8000/
python -m http.server

# VI config to save files with +x when a shebang is found on line 1
au BufWritePost * if getline(1) =~ "^#!" | if getline(1) =~ "/bin/" | silent !chmod +x <afile> | endif | endif

# I finally found out how to use notify-send with at or cron
echo "export DISPLAY=:0; export XAUTHORITY=~/.Xauthority; notify-send test" | at now+1minute

# perl one-liner to get the current week number
date +%V

# Execute a command with a timeout
timeout 10 sleep 11

# Find files that were modified by a given command
touch /tmp/file ; $EXECUTECOMMAND ; find /path -newer /tmp/file

# Have an ssh session open forever
autossh -M50000 -t server.example.com 'screen -raAd mysession'

# pipe output of a command to your clipboard
some command|xsel --clipboard

# Recursively compare two directories and output their differences on a readable format
diff -urp /originaldirectory /modifieddirectory

# Make anything more awesome
command | figlet

# When feeling down, this command helps
sl

# List recorded formular fields of Firefox
cd ~/.mozilla/firefox/ && sqlite3 `cat profiles.ini | grep Path | awk -F= '{print $2}'`/formhistory.sqlite "select * from moz_formhistory" && cd - > /dev/null

# Base conversions with bc
echo "obase=2; 27" | bc -l

# ls -hog --> a more compact ls -l
ls -hog

# Start a command on only one CPU core
taskset -c 0 your_command

# Get all the keyboard shortcuts in screen
^A ?

# Switch 2 characters on a command line.
ctrl-t

# Notepad in a browser (type this in the URL bar)
data:text/html, <html contenteditable>

# convert single digit to double digits
for i in ?.ogg; do mv $i 0$i; done

# Annotate tail -f with timestamps
tail -f file | while read; do echo "$(date +%T.%N) $REPLY"; done

# Stamp a text line on top of the pdf pages.
echo "This text gets stamped on the top of the pdf pages." | enscript -B -f Courier-Bold16 -o- | ps2pdf - | pdftk input.pdf stamp - output output.pdf

# commandlinefu.com by David Winterbottom

# Create a file server, listening in port 7000
while true; do nc -l 7000 | tar -xvf -; done

# bypass any aliases and functions for the command
\foo

# cat a bunch of small files with file indication
grep . *

# Find broken symlinks
find -L . -type l

# stderr in color
mycommand 2> >(while read line; do echo -e "\e[01;31m$line\e[0m"; done)

# Stop Flash from tracking everything you do.
for i in ~/.adobe ~/.macromedia ; do ( rm $i/ -rf ; ln -s /dev/null $i ) ; done

# Save a file you edited in vim without the needed permissions (no echo)
:w !sudo tee > /dev/null %

# Delete all empty lines from a file with vim
:g/^$/d

# Remote screenshot
DISPLAY=":0.0" import -window root screenshot.png

# your terminal sings
echo {1..199}" bottles of beer on the wall, cold bottle of beer, take one down, pass it around, one less bottle of beer on the wall,, " | espeak -v english -s 140

# Define words and phrases with google.
define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Po '(?<=<li>)[^<]+'|nl|perl -MHTML::Entities -pe 'decode_entities($_)' 2>/dev/null;}

# Harder, Faster, Stronger SSH clients
ssh -4 -C -c blowfish-cbc

# Clean up poorly named TV shows.
rename -v 's/.*[s,S](\d{2}).*[e,E](\d{2}).*\.avi/SHOWNAME\ S$1E$2.avi/' poorly.named.file.s01e01.avi

# Backup all MySQL Databases to individual files
for db in $(mysql -e 'show databases' -s --skip-column-names); do mysqldump $db | gzip > "/backups/mysqldump-$(hostname)-$db-$(date +%Y-%m-%d-%H.%M.%S).gz"; done

# check open ports
lsof -Pni4 | grep LISTEN

# Triple monitoring in screen
tmpfile=$(mktemp) && echo -e 'startup_message off\nscreen -t top htop\nsplit\nfocus\nscreen -t nethogs nethogs wlan0\nsplit\nfocus\nscreen -t iotop iotop' > $tmpfile && sudo screen -c $tmpfile

# Save an HTML page, and covert it to a .pdf file
wget $URL | htmldoc --webpage -f "$URL".pdf - ; xpdf "$URL".pdf &

# DELETE all those duplicate files but one based on md5 hash comparision in the current directory tree
find . -type f -print0|xargs -0 md5sum|sort|perl -ne 'chomp;$ph=$h;($h,$f)=split(/\s+/,$_,2);print "$f"."\x00" if ($h eq $ph)'|xargs -0 rm -v --

# create an emergency swapfile when the existing swap space is getting tight
sudo dd if=/dev/zero of=/swapfile bs=1024 count=1024000;sudo mkswap /swapfile; sudo swapon /swapfile

# Relocate a file or directory, but keep it accessible on the old location throug a simlink.
mv $1 $2 && ln -s $2/$(basename $1) $(dirname $1)

# a short counter
yes '' | cat -n

# Rsync remote data as root using sudo
rsync --rsync-path 'sudo rsync' username@source:/folder/ /local/

# Transfer SSH public key to another machine in one step
ssh-keygen; ssh-copy-id user@host; ssh user@host

# git remove files which have been deleted
git rm $(git ls-files --deleted)

# Copy stdin to your X11 buffer
ssh user@host cat /path/to/some/file | xclip

# commandlinefu.com by David Winterbottom

# Get info about remote host ports and OS detection
nmap -sS -P0 -sV -O <target>

# List of commands you use most often
history | awk '{print $2}' | sort | uniq -c | sort -rn | head

# Copy a file structure without files
find * -type d -exec mkdir /where/you/wantem/\{\} \;

# Get list of servers with a specific port open
nmap -sT -p 80 -oG - 192.168.1.* | grep open

# Display current time in requested time zones.
zdump Japan America/New_York

# dmesg with colored human-readable dates
dmesg -T|sed -e 's|\(^.*'`date +%Y`']\)\(.*\)|\x1b[0;34m\1\x1b[0m - \2|g'

# Extract audio from Flash video (*.flv) as mp3 file
ffmpeg -i video.flv -vn -ar 44100 -ac 2 -ab 192k -f mp3 audio.mp3

# Share your terminal session real-time
mkfifo foo; script -f foo

# Short and elegant way to backup a single file before you change it.
cp httpd.conf{,.bk}

# clean up memory of unnecessary things (Kernerl 2.6.16 or newer)
sync && echo 1 > /proc/sys/vm/drop_caches

# Find all the links to a file
find -L / -samefile /path/to/file -exec ls -ld {} +

# Recover tmp flash videos (deleted immediately by the browser plugin)
for h in `find /proc/*/fd -ilname "/tmp/Flash*" 2>/dev/null`; do ln -s "$h" `readlink "$h" | cut -d' ' -f1`; done

# Single use vnc-over-ssh connection
ssh -f -L 5900:localhost:5900 your.ssh.server "x11vnc -safer -localhost -nopw -once -display :0"; vinagre localhost:5900

# send a circular
echo "dear admin, please ban eribsskog" | wall

# Visit wikileaks.com
echo 213.251.145.96 wikileaks.com >>/etc/hosts

# List all open ports and their owning executables
lsof -i -P | grep -i "listen"

# Create a single PDF from multiple images with ImageMagick
convert *.jpg output.pdf

# dd with progress bar and statistics
sudo dd if=/dev/sdc bs=4096 | pv -s 2G | sudo dd bs=4096 of=~/USB_BLACK_BACKUP.IMG

# View all date formats, Quick Reference Help Alias
alias dateh='date --help|sed -n "/^ *%%/,/^ *%Z/p"|while read l;do F=${l/% */}; date +%$F:"|'"'"'${F//%n/ }'"'"'|${l#* }";done|sed "s/\ *|\ */|/g" |column -s "|" -t'

# Monitor open connections for httpd including listen, count and sort it per IP
watch "netstat -plan|grep :80|awk {'print \$5'} | cut -d: -f 1 | sort | uniq -c | sort -nk 1"

# output your microphone to a remote computer's speaker
arecord -f dat | ssh -C user@host aplay -f dat

# download and unpack tarball without leaving it sitting on your hard drive
wget -qO - http://example.com/path/to/blah.tar.gz | tar xzf -

# Colored diff ( via vim ) on 2 remotes files on your local computer.
vimdiff scp://root@server-foo.com//etc/snmp/snmpd.conf scp://root@server-bar.com//etc/snmp/snmpd.conf

# Split a tarball into multiple parts
tar cf - <dir>|split -b<max_size>M - <name>.tar.

# Matrix Style
echo -e "\e[32m"; while :; do for i in {1..16}; do r="$(($RANDOM % 2))"; if [[ $(($RANDOM % 5)) == 1 ]]; then if [[ $(($RANDOM % 4)) == 1 ]]; then v+="\e[1m $r   "; else v+="\e[2m $r   "; fi; else v+="     "; fi; done; echo -e "$v"; v=""; done

# commandlinefu.com by David Winterbottom

# Pretty Print a simple csv in the command line
column -s, -t <tmp.csv

# Ultimate current directory usage command
ncdu

# Cleanup firefox's database.
find ~/.mozilla/firefox/ -type f -name "*.sqlite" -exec sqlite3 {} VACUUM \;

# Terminal - Show directories in the PATH, one per line with sed and bash3.X `here string'
tr : '\n' <<<$PATH

# Find Duplicate Files (based on MD5 hash)
find -type f -exec md5sum '{}' ';' | sort | uniq --all-repeated=separate -w 33 | cut -c 35-

# Print a great grey scale demo !
yes "$(seq 232 255;seq 254 -1 233)" | while read i; do printf "\x1b[48;5;${i}m\n"; sleep .01; done

# Smiley Face Bash Prompt
PS1="\`if [ \$? = 0 ]; then echo \e[33\;40m\\\^\\\_\\\^\e[0m; else echo \e[36\;40m\\\-\e[0m\\\_\e[36\;40m\\\-\e[0m; fi\` \u \w:\h)"

# Create a system overview dashboard on F12 key
bind '"\e[24~"':"\"ps -elF;df -h;free -mt;netstat -lnpt;who -a\C-m"""

# coloured tail
tail -f FILE | perl -pe 's/KEYWORD/\e[1;31;43m$&\e[0m/g'

# Search for commands from the command line
clfu-seach <search words>

# Install a Firefox add-on/theme to all users
sudo firefox -install-global-extension /path/to/add-on

# clear current line
CTRL+u

# Convert all MySQL tables and fields to UTF8
mysql --database=dbname -B -N -e "SHOW TABLES"  | awk '{print "ALTER TABLE", $1, "CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;"}' | mysql --database=dbname &

# Put readline into vi mode
set -o vi

# Delete all empty lines from a file with vim
:g!/\S/d

# Backup a remote database to your local filesystem
ssh user@host 'mysqldump dbname | gzip' > /path/to/backups/db-backup-`date +%Y-%m-%d`.sql.gz

# Recursively remove .svn directories from the current location
find . -type d -name '.svn' -print0 | xargs -0 rm -rdf

# Start a new command in a new screen window
alias s='screen -X screen'; s top; s vi; s man ls;

# Efficiently print a line deep in a huge log file
sed '1000000!d;q' < massive-log-file.log

# Encrypted archive with openssl and tar
tar --create --file - --posix --gzip -- <dir> | openssl enc -e -aes256 -out <file>

# Remove a range of lines from a file
sed -i <file> -re '<start>,<end>d'

# Hide the name of a process listed in the `ps` output
exec -a "/sbin/getty 38400 tty7" your_cmd -erase_all_files

# Create a local compressed tarball from remote host directory
ssh user@host "tar -zcf - /path/to/dir" > dir.tar.gz

# convert from hexidecimal or octal to decimal
echo $((0x1fe)) $((033))

# save man-page as pdf
man -t awk | ps2pdf - awk.pdf

# commandlinefu.com by David Winterbottom

# Convert seconds into minutes and seconds
echo 'obase=60;299' | bc

# List by size all of the directories in a given tree.
du -h /path | sort -h

# All IP connected to  my host
netstat -lantp | grep ESTABLISHED |awk '{print $5}' | awk -F: '{print $1}' | sort -u

# df without line wrap on long FS name
df -P | column -t

# rsync instead of scp
rsync --progress --partial --rsh="ssh -p 8322" --bwlimit=100 --ipv4 user@domain.com:~/file.tgz .

# Download a file and uncompress it while it downloads
wget http://URL/FILE.tar.gz -O - | tar xfz -

# Reuse last parameter
!$

# Make sudo forget password instantly
sudo -K

# View user activity per directory.
sudo lsof -u someuser -a +D /etc

# Print a row of characters across the terminal
printf "%`tput cols`s"|tr ' ' '#'

# Limit bandwidth usage by apt-get
sudo apt-get -o Acquire::http::Dl-Limit=30 upgrade

# Convert text to picture
echo -e "Some Text Line1\nSome Text Line 2" | convert -background none -density 196  -resample 72 -unsharp 0x.5 -font "Courier" text:- -trim +repage -bordercolor white -border 3  text.gif

# track flights from the command line
flight_status() { if [[ $# -eq 3 ]];then offset=$3; else offset=0; fi; curl "http://mobile.flightview.com/TrackByRoute.aspx?view=detail&al="$1"&fn="$2"&dpdat=$(date +%Y%m%d -d ${offset}day)" 2>/dev/null |html2text |grep ":"; }

# Tune your guitar from the command line.
for n in E2 A2 D3 G3 B3 E4;do play -n synth 4 pluck $n repeat 2;done

# Remove executable bit from all files in the current directory recursively, excluding other directories
chmod -R -x+X *

# convert filenames in current directory to lowercase
rename 'y/A-Z/a-z/' *

# More precise BASH debugging
env PS4=' ${BASH_SOURCE}:${LINENO}(${FUNCNAME[0]}) ' sh -x /etc/profile

# Remove color codes (special characters) with sed
sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g"

# redirect stdout and stderr each to separate files and print both to the screen
(some_command 2>&1 1>&3 | tee /path/to/errorlog ) 3>&1 1>&2 | tee /path/to/stdoutlog

# get all pdf and zips from a website using wget
wget --reject html,htm --accept pdf,zip -rl1 url

# bash: hotkey to put current commandline to text-editor
bash-hotkey: <CTRL+x+e>

# Use all the cores or CPUs when compiling
make -j 4

# Prints total line count contribution per user for an SVN repository
svn ls -R | egrep -v -e "\/$" | xargs svn blame | awk '{print $2}' | sort | uniq -c | sort -r

# Analyze awk fields
awk '{print NR": "$0; for(i=1;i<=NF;++i)print "\t"i": "$i}'

# Create a list of binary numbers
echo {0..1}{0..1}{0..1}{0..1}

# commandlinefu.com by David Winterbottom

# Run a command, store the output in a pastebin on the internet and place the URL on the xclipboard
ls | curl -F 'sprunge=<-' http://sprunge.us | xclip

# Get your public ip using dyndns
curl -s http://checkip.dyndns.org/ | grep -o "[[:digit:].]\+"

# Start screen in detached mode
screen -d -m [<command>]

# How to run X without any graphics hardware
startx -- `which Xvfb` :1 -screen 0 800x600x24 && DISPLAY=:1 x11vnc

# Cut out a piece of film from a file. Choose an arbitrary length and starting time.
ffmpeg -vcodec copy -acodec copy -i orginalfile -ss 00:01:30 -t 0:0:20 newfile

# iso-8859-1 to utf-8 safe recursive rename
detox -r -s utf_8 /path/to/old/win/files/dir

# List the files any process is using
lsof +p xxxx

# Pipe STDOUT to vim
tail -1000 /some/file | vim -

# Show biggest files/directories, biggest first with 'k,m,g' eyecandy
du --max-depth=1 | sort -r -n | awk '{split("k m g",v); s=1; while($1>1024){$1/=1024; s++} print int($1)" "v[s]"\t"$2}'

# Terminate a frozen SSH-session
RETURN~.

# change directory to actual path instead of symlink path
cd `pwd -P`

# Download an entire static website to your local machine
wget --recursive  --page-requisites --convert-links www.moyagraphix.co.za

# Batch convert files to utf-8
find . -name "*.php" -exec iconv -f ISO-8859-1 -t UTF-8 {} -o ../newdir_utf8/{} \;

# Get http headers for an url
curl -I www.commandlinefu.com

# vi a remote file
vi scp://username@host//path/to/somefile

# Show permissions of current directory and all directories upwards to /
namei -m $(pwd)

# Use top to monitor only all processes with the same name fragment 'foo'
top -p $(pgrep -d , foo)

# delete command line last word
ctrl+w

# move you up one directory quickly
shopt -s autocd

# Remove a line from a file using sed (useful for updating known SSH server keys when they change)
ssh-keygen -R <thehost>

# Show what PID is listening on port 80 on Linux
fuser -v 80/tcp

# Draw kernel module dependancy graph.
lsmod | awk 'BEGIN{print "digraph{"}{split($4, a, ","); for (i in a) print $1, "->", a[i]}END{print "}"}'|display

# Color man pages
echo "export LESS_TERMCAP_mb=$'\E[01;31m'" >> ~/.bashrc

# List files accessed by a command
strace -ff -e trace=file my_command 2>&1 | perl -ne 's/^[^"]+"(([^\\"]|\\[\\"nt])*)".*/$1/ && print'

# Protect directory from an overzealous rm -rf *
cd <directory>; touch ./-i

# commandlinefu.com by David Winterbottom

# Watch RX/TX rate of an interface in kb/s
while [ /bin/true ]; do OLD=$NEW; NEW=`cat /proc/net/dev | grep eth0 | tr -s ' ' | cut -d' ' -f "3 11"`; echo $NEW $OLD | awk '{printf("\rin: % 9.2g\t\tout: % 9.2g", ($1-$3)/1024, ($2-$4)/1024)}'; sleep 1; done

# Figure out what shell you're running
echo $0

# Blink LED Port of NIC Card
ethtool -p eth0

# See where a shortened url takes you before click
check(){ curl -sI $1 | sed -n 's/Location: *//p';}

# Running scripts after a reboot for non-root users .
@reboot <yourscript.sh>

# run command on a group of nodes in parallel
echo "uptime" | tee >(ssh host1) >(ssh host2) >(ssh host3)

# run command on a group of nodes in parallel
echo "uptime" | pee "ssh host1" "ssh host2" "ssh host3"

# Remove Thumbs.db files from folders
find ./ -name Thumbs.db -delete

# Display BIOS Information
# dd if=/dev/mem bs=1k skip=768 count=256 2>/dev/null | strings -n 8

# open path with your default program (on Linux/*BSD)
xdg-open [path]

# Copy an element from the previous command
!:1-3

# use the previous commands params in the current command
!!:[position]

# Mirror a directory structure from websites with an Apache-generated file indexes
lftp -e "mirror -c" http://example.com/foobar/

# Choose from a nice graphical menu which DI.FM radio station to play
zenity --list --width 500 --height 500 --column 'radio' --column 'url' --print-column 2 $(curl -s http://www.di.fm/ | awk -F '"' '/href="http:.*\.pls.*96k/ {print $2}' | sort | awk -F '/|\.' '{print $(NF-1) " " $0}') | xargs mplayer

# Quickly share code or text from vim to others.
:w !curl -F "sprunge=<-" http://sprunge.us | xclip

# copy from host1 to host2, through your host
ssh root@host1 "cd /somedir/tocopy/ && tar -cf - ." | ssh root@host2 "cd /samedir/tocopyto/ && tar -xf -"

# Change prompt to MS-DOS one (joke)
export PS1="C:\$( pwd | sed 's:/:\\\\\\:g' )\\> "

# View network activity of any application or user in realtime
lsof -r 2 -p PID -i -a

# Print a list of standard error codes and descriptions.
perl -le 'print $!+0, "\t", $!++ for 0..127'

# Unbelievable Shell Colors, Shading, Backgrounds, Effects for Non-X
for c in `seq 0 255`;do t=5;[[ $c -lt 108 ]]&&t=0;for i in `seq $t 5`;do echo -e "\e[0;48;$i;${c}m|| $i:$c `seq -s+0 $(($COLUMNS/2))|tr -d '[0-9]'`\e[0m";done;done

# grep -v with multiple patterns.
grep 'test' somefile | grep -vE '(error|critical|warning)'

# Identify long lines in a file
awk 'length>72' file

# Show directories in the PATH, one per line
echo "${PATH//:/$'\n'}"

# Mount the first NTFS partition inside a VDI file (VirtualBox Disk Image)
mount -t ntfs-3g -o ro,loop,uid=user,gid=group,umask=0007,fmask=0117,offset=0x$(hd -n 1000000  image.vdi | grep "eb 52 90 4e 54 46 53" | cut -c 1-8) image.vdi /mnt/vdi-ntfs

# Show me a histogram of the busiest minutes in a log file:
cat /var/log/secure.log | awk '{print substr($0,0,12)}' | uniq -c | sort -nr | awk '{printf("\n%s ",$0) ; for (i = 0; i<$1 ; i++) {printf("*")};}'

# commandlinefu.com by David Winterbottom

# Display current bandwidth statistics
ifstat -nt

# Given process ID print its environment variables
sed 's/\o0/\n/g' /proc/INSERT_PID_HERE/environ

# restoring some data from a corrupted text file
( cat badfile.log ; tac badfile.log | tac ) > goodfile.log

# view the system console remotely
sudo cat /dev/vcs1 | fold -w 80

# Fix Ubuntu's Broken Sound Server
sudo killall -9 pulseaudio; pulseaudio >/dev/null 2>&1 &

# Look up the definition of a word
curl dict://dict.org/d:something

# Diff files on two remote hosts.
diff <(ssh alice cat /etc/apt/sources.list) <(ssh bob cat /etc/apt/sources.list)

# Ctrl+S Ctrl+Q terminal output lock and unlock
Ctrl+S Ctrl+Q

# Redirect STDIN
< /path/to/file.txt grep foo

# I hate `echo X | Y`
base64 -d <<< aHR0cDovL3d3dy50d2l0dGVyc2hlZXAuY29tL3Jlc3VsdHMucGhwP3U9Y29tbWFuZGxpbmVmdQo=

# Schedule a download at a later time
echo 'wget url' | at 01:00

# Send keypresses to an X application
xvkbd -xsendevent -text "Hello world"

# Add calendar to desktop wallpaper
convert -font -misc-fixed-*-*-*-*-*-*-*-*-*-*-*-* -fill black -draw "text 270,260 \" `cal` \"" testpic.jpg newtestpic.jpg

# Browse system RAM in a human readable form
sudo cat /proc/kcore | strings | awk 'length > 20' | less

# Get Cisco network information
tcpdump -nn -v -i eth0 -s 1500 -c 1 'ether[20:2] == 0x2000'

# Quick glance at who's been using your system recently
last  | grep -v "^$" | awk '{ print $1 }' | sort -nr | uniq -c

# Generat a Random MAC address
MAC=`(date; cat /proc/interrupts) | md5sum | sed -r 's/^(.{10}).*$/\1/; s/([0-9a-f]{2})/\1:/g; s/:$//;'`

# ping a range of IP addresses
nmap -sP 192.168.1.100-254

# Check if system is 32bit or 64bit
arch

# Find the most recently changed files (recursively)
find . -type f -printf '%TY-%Tm-%Td %TT %p\n' | sort

# Ask for a password, the passwd-style
read -s -p"Password: " USER_PASSWORD_VARIABLE; echo

# monitor memory usage
watch vmstat -sSM

# Content search.
ff() { local IFS='|'; grep -rinE "$*" . ; }

# List 10 largest directories in current directory
du -hs */ | sort -hr | head

# Stream YouTube URL directly to MPlayer
yt () mplayer -fs -quiet $(youtube-dl -g "$1")

# commandlinefu.com by David Winterbottom

# List open files that have no links to them on the filesystem
lsof +L1

# List of commands you use most often
history | awk '{a[$2]++}END{for(i in a){print a[i] " " i}}' | sort -rn | head > /tmp/cmds | gnuplot -persist <(echo 'plot "/tmp/cmds" using 1:xticlabels(2) with boxes')

# find all active IP addresses in a network
nmap -sP 192.168.1.0/24; arp -n  | grep "192.168.1.[0-9]* *ether"

# Convert all Flac in a directory to Mp3 using maximum quality variable bitrate
for file in *.flac; do flac -cd "$file" | lame -q 0 --vbr-new -V 0 - "${file%.flac}.mp3"; done

# Convert a Nero Image File to ISO
dd bs=1k if=image.nrg of=image.iso skip=300

# Copy with progress
rsync --progress file1 file2

# a shell function to print a ruler the width of the terminal window.
ruler() { for s in '....^....|' '1234567890'; do w=${#s}; str=$( for (( i=1; $i<=$(( ($COLUMNS + $w) / $w )) ; i=$i+1 )); do echo -n $s; done ); str=$(echo $str | cut -c -$COLUMNS) ; echo $str; done; }

# quickest (i blv) way to get the current program name minus the path (BASH)
path_stripped_programname="${0##*/}"

# A function to output a man page as a pdf file
function man2pdf(){ man -t ${1:?Specify man as arg} | ps2pdf -dCompatibility=1.3 - - > ${1}.pdf; }

# a trash function for bash
trash <file>

# Play music from youtube without download
wget -q -O - `youtube-dl -b -g $url`| ffmpeg -i - -f mp3 -vn -acodec libmp3lame -| mpg123  -

# generate a unique and secure password for every website that you login to
sitepass() { echo -n "$@" |  md5sum | sha1sum | sha224sum | sha256sum | sha384sum | sha512sum | gzip - | strings -n 1 | tr -d "[:space:]"  | tr -s '[:print:]' | tr '!-~' 'P-~!-O' | rev | cut -b 2-11; history -d $(($HISTCMD-1)); }

# Replace spaces in filenames with underscores
rename -v 's/ /_/g' *

# find and delete empty dirs, start in current working dir
find . -empty -type d -exec rmdir {} +

# Move all images in a directory into a directory hierarchy based on year, month and day based on exif information
exiftool '-Directory<DateTimeOriginal' -d %Y/%m/%d dir

# Follow tail by name (fix for rolling logs with tail -f)
tail -F file

# Colored SVN diff
svn diff <file> | vim -R -

# Find broken symlinks and delete them
find -L /path/to/check -type l -delete

# Find if the command has an alias
type -all command

# Show a config file without comments
egrep -v "^$|^[[:space:]]*#" /etc/some/file

# Download all Delicious bookmarks
curl -u username -o bookmarks.xml https://api.del.icio.us/v1/posts/all

# beep when a server goes offline
while true; do [ "$(ping -c1W1w1 server-or-ip.com | awk '/received/ {print $4}')" != 1 ] && beep; sleep 1; done

# Number of open connections per ip.
netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

# Create a favicon
convert -colors 256 -resize 16x16 face.jpg face.ppm && ppmtowinicon -output favicon.ico face.ppm

# Quickly generate an MD5 hash for a text string using OpenSSL
echo -n 'text to be encrypted' | openssl md5

# commandlinefu.com by David Winterbottom

# create dir tree
mkdir -p doc/{text/,img/{wallpaper/,photos/}}

# Check Ram Speed and Type in Linux
sudo dmidecode --type 17 | more

# Run any GUI program remotely
ssh -fX <user>@<host> <program>

# Run the Firefox Profile Manager
firefox -no-remote -P

# Delete the specified line
sed -i 8d ~/.ssh/known_hosts

# Backup your hard drive with dd
sudo dd if=/dev/sda of=/media/disk/backup/sda.backup

# Add forgotten changes to the last git commit
git commit --amend

# Sort dotted quads
sort -nt . -k 1,1 -k 2,2 -k 3,3 -k 4,4

# Press ctrl+r in a bash shell and type a few letters of a previous command
^r in bash begins a reverse-search-history with command completion

# Extract audio from a video
ffmpeg -i video.avi -f mp3 audio.mp3

# Get Dell Service Tag Number from a Dell Machine
sudo dmidecode | grep Serial\ Number | head -n1

# Resume aborted scp file transfers
rsync --partial --progress --rsh=ssh SOURCE DESTINATION

# Use last argument of last command
file !$

# Commandline document conversion with Libreoffice
soffice --headless -convert-to odt:"writer8" somefile.docx

# HourGlass
hourglass(){ trap 'tput cnorm' 0 1 2 15 RETURN;local s=$(($SECONDS +$1));(tput civis;while (($SECONDS<$s));do for f in '|' '\' '-' '/';do echo -n "$f";sleep .2s;echo -n $'\b';done;done;);}

# Transfer a file to multiple hosts over ssh
pscp -h hosts.txt -l username /etc/hosts /tmp/hosts

# Verify/edit bash history command before executing it
shopt -s histverify

# Resize an image to at least a specific resolution
convert -resize '1024x600^' image.jpg small-image.jpg

# Print without executing the last command that starts with...
!ssh:p

# Query well known ports list
getent services <<service>>

# Create .pdf from .doc
oowriter -pt pdf your_word_file.doc

# Diff XML files
diffxml() { diff -wb <(xmllint --format "$1") <(xmllint --format "$2"); }

# Gets the english pronunciation of a phrase
say() { mplayer "http://translate.google.com/translate_tts?q=$1"; }

# What is the use of this switch ?
manswitch () { man $1 | less -p "^ +$2"; }

# Save the list of all available commands in your box to a file
compgen -c | sort -u > commands

# commandlinefu.com by David Winterbottom

# clear screen, keep prompt at eye-level (faster than clear(1), tput cl, etc.)
cls(){ printf "\33[2J";} or, if no printf, cat >cls;<ctrl-v><ctrl+[>[2J<enter><ctrl+d> cls(){ cat cls;}

# Down for everyone or just me?
down4me() { wget -qO - "http://www.downforeveryoneorjustme.com/$1" | sed '/just you/!d;s/<[^>]*>//g' ; }

# Run a program transparently, but print a stack trace if it fails
gdb -batch -ex "run" -ex "bt" ${my_program} 2>&1 | grep -v ^"No stack."$

# Compare copies of a file with md5
cmp file1 file2

# backup delicious bookmarks
curl --user login:password -o DeliciousBookmarks.xml -O 'https://api.del.icio.us/v1/posts/all'

# Rename all .jpeg and .JPG files to have .jpg extension
rename 's/\.jpe?g$/.jpg/i' *

# pretend to be busy in office to enjoy a cup of coffee
j=0;while true; do let j=$j+1; for i in $(seq 0 20 100); do echo $i;sleep 1; done | dialog --gauge "Install part $j : `sed $(perl -e "print int rand(99999)")"q;d" /usr/share/dict/words`" 6 40;done

# Generate a Random MAC address
openssl rand -hex 6 | sed 's/\(..\)/\1:/g; s/.$//'

# Purge configuration files of removed packages on  debian based systems
aptitude purge '~c'

# Get all links of a website
lynx -dump http://www.domain.com | awk '/http/{print $2}'

# Find all active ip's in a subnet
sudo arp-scan -I eth0 192.168.1.0/24

# Display BIOS Information
dmidecode -t bios

# Disassemble some shell code
echo -ne "<shellcode>" | x86dis -e 0 -s intel

# make, or run a script, everytime a file in a directory is modified
while true; do inotifywait -r -e MODIFY dir/ && make; done;

# kill process by name
pkill -x firefox

# ignore the .svn directory in filename completion
export FIGNORE=.svn

# Ping scanning without nmap
for i in {1..254}; do ping -c 1 -W 1 10.1.1.$i | grep 'from'; done

# Working random fact generator
wget randomfunfacts.com -O - 2>/dev/null | grep \<strong\> | sed "s;^.*<i>\(.*\)</i>.*$;\1;"

# Remote backups with tar over ssh
tar jcpf - [sourceDirs] |ssh user@host "cat > /path/to/backup/backupfile.tar.bz2"

# Pronounce an English word using Dictionary.com
pronounce(){ wget -qO- $(wget -qO- "http://dictionary.reference.com/browse/$@" | grep 'soundUrl' | head -n 1 | sed 's|.*soundUrl=\([^&]*\)&.*|\1|' | sed 's/%3A/:/g;s/%2F/\//g') | mpg123 -; }

# Make ISO image of a folder
mkisofs -J -allow-lowercase -R -V "OpenCD8806" -iso-level 4 -o OpenCD.iso ~/OpenCD

# Change pidgin status
purple-remote "setstatus?status=away&message=AFK"

# Grep by paragraph instead of by line.
grepp() { [ $# -eq 1 ] && perl -00ne "print if /$1/i" || perl -00ne "print if /$1/i" < "$2";}

# Vim: Switch from Horizontal split to Vertical split
^W-L

# Numbers guessing game
A=1;B=100;X=0;C=0;N=$[$RANDOM%$B+1];until [ $X -eq $N ];do read -p "N between $A and $B. Guess? " X;C=$(($C+1));A=$(($X<$N?$X:$A));B=$(($X>$N?$X:$B));done;echo "Took you $C tries, Einstein";

# commandlinefu.com by David Winterbottom

# generate random password
pwgen -Bs 10 1

# Change user, assume environment, stay in current dir
su -- user

# Testing hard disk reading speed
hdparm -t /dev/sda

# Identify differences between directories (possibly on different servers)
diff <(ssh server01 'cd config; find . -type f -exec md5sum {} \;| sort -k 2') <(ssh server02 'cd config;find . -type f -exec md5sum {} \;| sort -k 2')

# How fast is the connexion to a URL, some stats from curl
URL="http://www.google.com";curl -L --w "$URL\nDNS %{time_namelookup}s  conn %{time_connect}s  time %{time_total}s\nSpeed %{speed_download}bps Size %{size_download}bytes\n" -o/dev/null -s $URL

# move a lot of files over ssh
rsync -az /home/user/test user@sshServer:/tmp/

# List programs with open ports and connections
lsof -i

# Show git branches by date - useful for showing active branches
for k in `git branch|perl -pe s/^..//`;do echo -e `git show --pretty=format:"%Cgreen%ci %Cblue%cr%Creset" $k|head -n 1`\\t$k;done|sort -r

# disable history for current shell session
unset HISTFILE

# Share a 'screen'-session
screen -x

# Show all detected mountable Drives/Partitions/BlockDevices
hwinfo --block --short

# Monitor TCP opened connections
watch -n 1 "netstat -tpanl | grep ESTABLISHED"

# Fibonacci numbers with awk
seq 50| awk 'BEGIN {a=1; b=1} {print a; c=a+b; a=b; b=c}'

# Read the output of a command into the buffer in vim
:r !command

# Calculates the date 2 weeks ago from Saturday the specified format.
date -d '2 weeks ago Saturday' +%Y-%m-%d

# Find broken symlinks
find . -type l ! -exec test -e {} \; -print

# Add your public SSH key to a server in one command
cat .ssh/id_rsa.pub | ssh hostname 'cat >> .ssh/authorized_keys'

# ssh tunnel with auto reconnect ability
while [ ! -f /tmp/stop ]; do ssh -o ExitOnForwardFailure=yes -R 2222:localhost:22 target "while nc -zv localhost 2222; do sleep 5; done"; sleep 5;done

# find process associated with a port
fuser [portnumber]/[proto]

# cycle through a 256 colour palette
yes "$(seq 232 255;seq 254 -1 233)" | while read i; do printf "\x1b[48;5;${i}m\n"; sleep .01; done

# scping files with streamlines compression (tar gzip)
tar czv file1 file2 folder1 | ssh user@server tar zxv -C /destination

# add all files not under version control to repository
svn status |grep '\?' |awk '{print $2}'| xargs svn add

# Count files beneath current directory (including subfolders)
find . -type f | wc -l

# Discover the process start time
ps -eo pid,lstart,cmd

# Run the built in PHP-server in current folder
php -S 127.0.0.1:8080

# commandlinefu.com by David Winterbottom

# Press enter and take a WebCam picture.
read && ffmpeg -y -r 1 -t 3 -f video4linux2 -vframes 1 -s sxga -i /dev/video0 ~/webcam-$(date +%m_%d_%Y_%H_%M).jpeg

# Automatically find and re-attach to a detached screen session
screen -D -R

# ping as traceroute
for i in {1..30}; do  ping -t $i -c 1 google.com; done | grep "Time to live exceeded"

# what model of computer I'm using?
sudo dmidecode | grep Product

# tail a log over ssh
ssh  -t remotebox "tail -f /var/log/remote.log"

# du with colored bar graph
t=$(df|awk 'NR!=1{sum+=$2}END{print sum}');sudo du / --max-depth=1|sed '$d'|sort -rn -k1 | awk -v t=$t 'OFMT="%d" {M=64; for (a=0;a<$1;a++){if (a>c){c=a}}br=a/c;b=M*br;for(x=0;x<b;x++){printf "\033[1;31m" "|" "\033[0m"}print " "$2" "(a/t*100)"% total"}'

# sort the output of the 'du' command by largest first, using human readable output.
du -h --max-depth=1 |sort -rh

# Target a specific column for pattern substitution
awk '{gsub("foo","bar",$5)}1' file

# Discovering all open files/dirs underneath a directory
lsof +D <dirname>

# Substrings a variable
var='123456789'; echo ${var:<start_pos>:<offset>}

# Check syntax for all PHP files in the current directory and all subdirectories
find . -name \*.php -exec php -l "{}" \;

# "Clone" a list of installed packages from one Debian/Ubuntu Server to another
apt-get install `ssh root@host_you_want_to_clone "dpkg -l | grep ii" | awk '{print $2}'`

# Timer with sound alarm
sleep 3s && espeak "wake up, you bastard" 2>/dev/null

# A formatting test for David Winterbottom: improving commandlinefu for submitters
echo "?????, these are the umlauted vowels I sing to you. Oh, and sometimes ?, but I don't sing that one cause it doesn't rhyme."

# Random unsigned integer
echo $(openssl rand 4 | od -DAn)

# kill all process that belongs to you
kill -9 -1

# Continue a current job in the background
<ctrl+z> bg

# Send email with curl and gmail
curl -n --ssl-reqd --mail-from "<user@gmail.com>" --mail-rcpt "<user@server.tld>" --url smtps://smtp.gmail.com:465 -T file.txt

# translates acronyms for you
wtf is <acronym>

# Create an animated gif from a Youtube video
url=http://www.youtube.com/watch?v=V5bYDhZBFLA; youtube-dl -b $url; mplayer $(ls ${url##*=}*| tail -n1) -ss 00:57 -endpos 10 -vo gif89a:fps=5:output=output.gif -vf scale=400:300 -nosound

# Print just line 4 from a textfile
sed -n '4{p;q}'

# Print just line 4 from a textfile
sed -n '4p'

# List bash functions defined in .bash_profile or .bashrc
compgen -A function

# Start a HTTP server which serves Python docs
pydoc -p 8888 & gnome-open http://localhost:8888

# Do some learning...
ls /usr/bin | xargs whatis | grep -v nothing | less

# commandlinefu.com by David Winterbottom

# Insert  the  last  argument  of  the previous command
<ALT> .

# Typing the current date ( or any string ) via a shortcut as if the keys had been actually typed with the hardware keyboard in any application.
xvkbd -xsendevent -text $(date +%Y%m%d)

# recursive search and replace old with new string, inside files
find . -type f -exec sed -i s/oldstring/newstring/g {} +

# Clean your broken terminal
stty sane

# geoip information
curl -s "http://www.geody.com/geoip.php?ip=$(curl -s icanhazip.com)" | sed '/^IP:/!d;s/<[^>][^>]*>//g'

# Backup a local drive into a file on the remote host via ssh
dd if=/dev/sda | ssh user@server 'dd of=sda.img'

# Sort all running processes by their memory & CPU usage
ps aux --sort=%mem,%cpu

# Kill processes that have been running for more than a week
find /proc -user myuser -maxdepth 1 -type d -mtime +7 -exec basename {} \; | xargs kill -9

# Save current layout of top
<Shift + W>

# Show directories in the PATH, one per line
echo $PATH | tr \: \\n

# An easter egg built into python to give you the Zen of Python
python -c 'import this'

# Add prefix onto filenames
rename 's/^/prefix/' *

# Stream YouTube URL directly to mplayer
id="dMH0bHeiRNg";mplayer -fs http://youtube.com/get_video.php?video_id=$id\&t=$(curl -s http://www.youtube.com/watch?v=$id | sed -n 's/.*, "t": "\([^"]*\)", .*/\1/p')

# Get all IPs via ifconfig
ifconfig -a | perl -nle'/(\d+\.\d+\.\d+\.\d+)/ && print $1'

# Pick a random line from a file
shuf -n1 file.txt

# Get all these commands in a text file with description.
for x in `jot - 0 2400 25`; do curl "http://www.commandlinefu.com/commands/browse/sort-by-votes/plaintext/$x"  ; done > commandlinefu.txt

# Stripping ^M at end of each line for files
dos2unix <filenames>

# Use Cygwin to talk to the Windows clipboard
cat /dev/clipboard; $(somecommand) > /dev/clipboard

# Backup files incremental with rsync to a NTFS-Partition
rsync -rtvu --modify-window=1 --progress /media/SOURCE/ /media/TARGET/

# Find removed files still in use via /proc
find -L /proc/*/fd -links 0 2>/dev/null

# Convert "man page" to text file
man ls | col -b > ~/Desktop/man_ls.txt

# Connect to google talk through ssh by setting your IM client to use the localhost 5432 port
ssh -f -N -L 5432:talk.google.com:5222 user@home.network.com

# Find last reboot time
who -b

# Get video information with ffmpeg
ffmpeg -i filename.flv

# for all flv files in a dir, grab the first frame and make a jpg.
for f in *.flv; do ffmpeg -y -i "$f" -f image2 -ss 10 -vframes 1 -an "${f%.flv}.jpg"; done

# commandlinefu.com by David Winterbottom

# Purge configuration files of removed packages on  debian based systems
sudo aptitude purge `dpkg --get-selections | grep deinstall | awk '{print $1}'`

# from within vi, pipe a chunk of lines to a command line and replace the chunk with the result
!}sort

# Using awk to sum/count a column of numbers.
cat count.txt | awk '{ sum+=$1} END {print sum}'

# Append stdout and stderr to a file, and print stderr to the screen [bash]
somecommand 2>&1 >> logfile | tee -a logfile

# quickly change all .html extensions on files in folder to .htm
for i in *.html ; do mv $i ${i%.html}.htm ; done

# Grep for word in directory (recursive)
grep --color=auto -iRnH "$search_word" $directory

# Another Curl your IP command
curl -s http://checkip.dyndns.org | sed 's/[a-zA-Z<>/ :]//g'

# count IPv4 connections per IP
netstat -anp |grep 'tcp\|udp' | awk '{print $5}' | sed s/::ffff:// | cut -d: -f1 | sort | uniq -c | sort -n

# pattern match in awk - no grep
awk '/pattern1/ && /pattern2/ && !/pattern3/ {print}'

# Optimal way of deleting huge numbers of files
find /path/to/dir -type f -print0 | xargs -0 rm

# Convert Shell Text to Upper/Lower Case
ALT-U / ALT-L

# grep processes list avoiding the grep itself
ps axu | grep [a]pache2

# repeat a command every one second
watch -n 1 "do foo"

# Swap the two last arguments of the current command line
<ctrl+e> <esc+t>

# Daemonize nc - Transmit a file like a http server
while ( nc -l 80 < /file.htm > : ) ; do : ; done &

# Redirect  tar extract to another directory
tar xfz filename.tar.gz -C PathToDirectory

# Run a command when a file is changed
while inotifywait -e modify /tmp/myfile; do firefox; done

# Find Malware in the current and sub directories by MD5 hashes
IFS=$'\n' && for f in `find . -type f -exec md5sum "{}" \;`; do echo $f | sed -r 's/^[^ ]+/Checking:/'; echo $f | cut -f1 -d' ' | netcat hash.cymru.com 43 ; done

# Execute a command, convert output to .png file, upload file to imgur.com, then returning the address of the .png.
imgur(){ $*|convert label:@- png:-|curl -F "image=@-" -F "key=1913b4ac473c692372d108209958fd15" http://api.imgur.com/2/upload.xml|grep -Eo "<original>(.)*</original>" | grep -Eo "http://i.imgur.com/[^<]*";}

# RDP through SSH tunnel
ssh -f -L3389:<RDP_HOST>:3389 <SSH_PROXY> "sleep 10" && rdesktop -T'<WINDOW_TITLE>' -uAdministrator -g800x600 -a8 -rsound:off -rclipboard:PRIMARYCLIPBOARD -5 localhost

# Rapidly invoke an editor to write a long, complex, or tricky command
<ESC> v or ctrl-x ctrl-e

# Remote screenshot
ssh user@remote-host "DISPLAY=:0.0 import -window root -format png -"|display -format png -

# List your MACs address
lsmac() { ifconfig -a | sed '/eth\|wl/!d;s/   Link.*HWaddr//' ; }

# ssh to machine behind shared NAT
ssh -NR 0.0.0.0:2222:127.0.0.1:22 user@jump.host.com

# Countdown Clock
MIN=10;for ((i=MIN*60;i>=0;i--));do echo -ne "\r$(date -d"0+$i sec" +%H:%M:%S)";sleep 1;done

# commandlinefu.com by David Winterbottom

# Look up a unicode character by name
egrep -i "^[0-9a-f]{4,} .*$*" $(locate CharName.pm) | while read h d; do /usr/bin/printf "\U$(printf "%08x" 0x$h)\tU+%s\t%s\n" $h "$d"; done

# Generate MD5 hash for a string
md5sum <<<"test"

# Ask user to confirm
Confirm() { read -sn 1 -p "$1 [Y/N]? "; [[ $REPLY = [Yy] ]]; }

# Make a file not writable / immutable by root
sudo chattr +i <file>

# prevent accidents and test your command with echo
echo rm *.txt

# Get My Public IP Address
curl ifconfig.me

# Empty a file
:> file

# Emptying a text file in one shot
:%d

# computes the most frequent used words of a text file
cat WAR_AND_PEACE_By_LeoTolstoi.txt | tr -cs "[:alnum:]" "\n"| tr "[:lower:]" "[:upper:]" | awk '{h[$1]++}END{for (i in h){print h[i]" "i}}'|sort -nr | cat -n | head -n 30

# Quick HTML image gallery from folder contents
find . -iname '*.jpg' -exec echo '<img src="{}">' \; > gallery.html

# check the status of 'dd' in progress (OS X)
killall -INFO dd

# Restrict the bandwidth for the SCP command
scp -l10 pippo@serverciccio:/home/zutaniddu/* .

# List all authors of a particular git project
git log --format='%aN' | sort -u

# live ssh network throughput test
pv /dev/zero|ssh $host 'cat > /dev/null'

# Carriage return for reprinting on the same line
while true; do echo -ne "$(date)\r"; sleep 1; done

# What is my ip?
curl http://www.whatismyip.org/

# Empty a file
truncate -s0 file

# List Network Tools in Linux
apropos network |more

# Function that outputs dots every second until command completes
sleeper(){ while `ps -p $1 &>/dev/null`; do echo -n "${2:-.}"; sleep ${3:-1}; done; }; export -f sleeper

# Search back through previous commands
Ctrl-R <search-text>

# Print text string vertically, one character per line.
echo "vertical text" | grep -o '.'

# Find running binary executables that were not installed using dpkg
cat /var/lib/dpkg/info/*.list > /tmp/listin ; ls /proc/*/exe |xargs -l readlink | grep -xvFf /tmp/listin; rm /tmp/listin

# Cleanup firefox's database.
pgrep -u `id -u` firefox-bin || find ~/.mozilla/firefox -name '*.sqlite'|(while read -e f; do echo 'vacuum;'|sqlite3 "$f" ; done)

# vim easter egg
$ vim ... :help 42

# Find the process you are looking for minus the grepped one
pgrep command_name

# commandlinefu.com by David Winterbottom

# VIM: Replace a string with an incrementing number between marks 'a and 'b (eg, convert string ZZZZ to 1, 2, 3, ...)
:let i=0 | 'a,'bg/ZZZZ/s/ZZZZ/\=i/ | let i=i+1

# Get the canonical, absolute path given a relative and/or noncanonical path
readlink -f ../super/symlink_bon/ahoy

# Create a Multi-Part Archive Without Proprietary Junkware
tar czv Pictures | split -d -a 3 -b 16M - pics.tar.gz.

# wrap long lines of a text
fold -s -w 90 file.txt

# Display last exit status of a command
echo $?

# Enable ** to expand files recursively (>=bash-4.0)
shopt -s globstar

# Command Line to Get the Stock Quote via Yahoo
curl -s 'http://download.finance.yahoo.com/d/quotes.csv?s=csco&f=l1'

# Convert camelCase to underscores (camel_case)
sed -r 's/([a-z]+)([A-Z][a-z]+)/\1_\l\2/g' file.txt

# Set your profile so that you resume or start a screen session on login
echo "screen -DR" >> ~/.bash_profile

# play high-res video files on a slow processor
mplayer -framedrop -vfm ffmpeg -lavdopts lowres=1:fast:skiploopfilter=all

# Grep colorized
grep -i --color=auto

# List your largest installed packages.
wajig large

# Monitor dynamic changes in the dmesg log.
watch "dmesg |tail -15"

# Generate a list of installed packages on Debian-based systems
dpkg --get-selections > LIST_FILE

# find the process that is using a certain port e.g. port 3000
lsof -P | grep ':3000'

# Pause Current Thread
ctrl-z

# Merge *.pdf files
gs -q -sPAPERSIZE=letter -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=out.pdf `ls *.pdf`

# Convert .wma files to .ogg with ffmpeg
find -name '*wma' -exec ffmpeg -i {} -acodec vorbis -ab 128k {}.ogg \;

# Generate Random Passwords
< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6

# Grep without having it show its own process in the results
ps aux | grep "[s]ome_text"

# Find recursively, from current directory down, files and directories whose names contain single or multiple whitespaces and replace each such occurrence with a single underscore.
find  ./  -name '*'  -exec  rename  's/\s+/_/g'  {}  \;

# Files extension change
rename .oldextension .newextension *.oldextension

# archive all files containing local changes (svn)
svn st | cut -c 8- | sed 's/^/\"/;s/$/\"/' | xargs tar -czvf ../backup.tgz

# Just run it ;)
echo SSBMb3ZlIFlvdQo= | base64 -d

# Show which programs are listening on TCP and UDP ports
netstat -plunt

# commandlinefu.com by David Winterbottom

# vim easter egg
$ vim ... :help 42

# copy with progress bar - rsync
rsync -rv <src> <dst> --progress

# find and replace tabs for spaces within files recursively
find ./ -type f -exec sed -i 's/\t/  /g' {} \;

# List your MACs address
cat /sys/class/net/eth0/address

# diff current vi buffer edits against original file
:w !diff -u % -

# Send data securly over the net.
cat /etc/passwd | openssl aes-256-cbc -a -e -pass pass:password | netcat -l -p 8080

# pretend to be busy in office to enjoy a cup of coffee
for i in `seq 0 100`;do timeout 6 dialog --gauge "Install..." 6 40 "$i";done

# JSON processing with Python
curl -s "http://feeds.delicious.com/v2/json?count=5" | python -m json.tool | less -R

# Get your external IP address without curl
wget -qO- icanhazip.com

# cycle through a 256 colour palette
yes "$(seq 1 255)" | while read i; do printf "\x1b[48;5;${i}m\n"; sleep .01; done

# Find all files larger than 500M and less than 1GB
find / -type f -size +500M -size -1G

# extract email adresses from some file (or any other pattern)
grep -Eio '([[:alnum:]_.-]+@[[:alnum:]_.-]+?\.[[:alpha:].]{2,6})'

# command line calculator
calc(){ awk "BEGIN{ print $* }" ;}

# Plays Music from SomaFM
read -p "Which station? "; mplayer --reallyquiet -vo none -ao sdl http://somafm.com/startstream=${REPLY}.pls

# infile search and replace on N files (including backup of the files)
perl -pi.bk -e's/foo/bar/g' file1 file2 fileN

# Create an SSH SOCKS proxy server on localhost:8000 that will re-start itself if something breaks the connection temporarily
autossh -f -M 20000 -D 8000 somehost -N

# Delete all files found in directory A from directory B
for file in <directory A>/*; do rm <directory B>/`basename $file`; done

# Block an IP address from connecting to a server
iptables -A INPUT -s 222.35.138.25/32 -j DROP

# Record microphone input and output to date stamped mp3 file
arecord -q -f cd -r 44100 -c2 -t raw | lame -S -x -h -b 128 - `date +%Y%m%d%H%M`.mp3

# loop over a set of items that contain spaces
ls | while read ITEM; do echo "$ITEM"; done

# Extract tar content without leading parent directory
tar -xaf archive.tar.gz --strip-components=1

# Function to split a string into an array
read -a ARR <<<'world domination now!'; echo ${ARR[2]};

# Update twitter via curl
curl -u user -d status="Tweeting from the shell" http://twitter.com/statuses/update.xml

# Check your spelling
aspell -a <<< '<WORDS>'

# View ~/.ssh/known_hosts key information
ssh-keygen -l -f ~/.ssh/known_hosts

# commandlinefu.com by David Winterbottom

# Binary digits Matrix effect
perl -e '$|++; while (1) { print " " x (rand(35) + 1), int(rand(2)) }'

# print multiplication formulas
seq 9 | sed 'H;g' | awk -v RS='' '{for(i=1;i<=NF;i++)printf("%dx%d=%d%s", i, NR, i*NR, i==NR?"\n":"\t")}'

# Rapidly invoke an editor to write a long, complex, or tricky command
<ESC> v

# add the result of a command into vi
!!command

# Super Speedy Hexadecimal or Octal Calculations and Conversions to Decimal.
echo "$(( 0x10 )) - $(( 010 )) = $(( 0x10 - 010 ))"

# bash shortcut: !$ !^ !* !:3 !:h and !:t
echo foo bar foobar barfoo && echo !$ !^  !:3 !* &&  echo /usr/bin/foobar&& echo !$:h !$:t

# Traceroute w/TCP to get through firewalls.
tcptraceroute www.google.com

# benchmark web server with apache benchmarking tool
ab -n 9000 -c 900 localhost:8080/index.php

# move a lot of files over ssh
tar -cf - /home/user/test | gzip -c | ssh user@sshServer 'cd /tmp; tar xfz -'

# sends a postscript file to a postscript printer using netcat
cat my.ps | nc -q 1 hp4550.mynet.xx 9100

# the same as [Esc] in vim
Ctrl + [

# open a screenshot of a remote desktop via ssh
xloadimage <(ssh USER@HOSTNAME DISPLAY=:0.0 import -window root png:-)

# Displays the attempted user name, ip address, and time of SSH failed logins on Debian machines
awk '/sshd/ && /Failed/ {gsub(/invalid user/,""); printf "%-12s %-16s %s-%s-%s\n", $9, $11, $1, $2, $3}' /var/log/auth.log

# Create a bunch of dummy files for testing
touch {1..10}.txt

# Quickly get summary of sizes for files and folders
du -sh *

# Temporarily ignore mismatched SSH host key
ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no username@host

# back up your commandlinefu contributed commands
curl http://www.commandlinefu.com/commands/by/<your username>/rss|gzip ->commandlinefu-contribs-backup-$(date +%Y-%m-%d-%H.%M.%S).rss.gz

# Find the package a command belongs to on Debian
dpkg -S $( which  ls )

# Replace spaces in filenames with underscorees
ls | while read f; do mv "$f" "${f// /_}";done

# Google text-to-speech in mp3 format
say(){ mplayer -user-agent Mozilla "http://translate.google.com/translate_tts?tl=en&q=$(echo $* | sed 's#\ #\+#g')" > /dev/null 2>&1 ;  }

# Terminal redirection
script /dev/null | tee /dev/pts/3

# Converts to PDF all the OpenOffice.org files in the directory
for i in $(ls *.od{tp}); do unoconv -f pdf $i; done

# Print info about your real user.
who loves mum

# Update twitter via curl (and also set the "from" bit)
curl -u twitter-username -d status="Hello World, Twitter!" -d source="cURL" http://twitter.com/statuses/update.xml

# Escape potential tarbombs
atb() { l=$(tar tf $1); if [ $(echo "$l" | wc -l) -eq $(echo "$l" | grep $(echo "$l" | head -n1) | wc -l) ]; then tar xf $1; else mkdir ${1%.tar.gz} && tar xf $1 -C ${1%.tar.gz}; fi ;}