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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

Top Tags





Maintained by Jon H.

Site originally by David Winterbottom (user root).

Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

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Terminal - All commands - 12,388 results
ASN=32934; for s in $(whois -H -h riswhois.ripe.net -- -F -K -i $ASN | grep -v "^$" | grep -v "^%" | awk '{ print $2 }' ); do echo " blocking $s"; sudo iptables -A INPUT -s $s -j REJECT &> /dev/null || sudo ip6tables -A INPUT -s $s -j REJECT; done
ss -t -o state established '( dport = :443 || dport = :80 )' | grep -Po '([0-9a-z:.]*)(?=:http[s])' | sort -u|netcat whois.cymru.com 43|grep -v "AS Name"|sort -t'|' -k3
ss -t -o state established '( dport = :443 || dport = :80 )'|grep tcp|awk '{ print $5 }'|sed s/:http[s]*//g|sort -u|netcat whois.cymru.com 43|grep -v "AS Name"|sort -t'|' -k3
for i in *.flac; do flac -d -c "${i}" |lame -h --preset 196 --ta "Artist Here" --tl "Disc Title Here" --add-id3v2 - "./MP3/$i.mp3"; done
function df_func { local dfts=$(ssh $1 "df -lP | tail -n +2 | sed 's/%//'"); echo $dfts | awk '$5 > 90 {exit 1}' > /dev/null; if [ $? == 1 ]; then echo -n "$1 "; echo $dfts | awk '$5 > 90 {printf "%s %d%%\n", $6, $5}'; fi }
find . -type f -printf '%T@ %TY-%Tm-%Td %TH:%TM:%.2TS %p\n' | sort -nr | head -n 5 | cut -f2- -d" "
2016-03-23 11:56:39
User: paulera
Functions: cut find head sort

The output format is given by the -printf parameter:

%T@ = modify time in seconds since Jan. 1, 1970, 00:00 GMT, with fractional part. Mandatory, hidden in the end.

%TY-%Tm-%Td %TH:%TM:%.2TS = modify time as YYYY-MM-DD HH:MM:SS. Optional.

%p = file path

Refer to http://linux.die.net/man/1/find for more about -printf formatting.


sort -nr = sort numerically and reverse (higher values - most recent timestamp - first)

head -n 5 = get only 5 first lines (change 5 to whatever you want)

cut -f2- -d" " = trim first field (timestamp, used only for sorting)


Very useful for building scripts for detecting malicious files upload and malware injections.

[ $[ $RANDOM % 6 ] == 0 ] && echo 'Bang!' || echo 'Click...'
2016-03-23 11:09:56
User: paulera
Functions: echo
Tags: bash fun

Shows "Bang!" in a chance of 1 out of 6, like in the original game with the gun (spin every round). Otherwise, echoes "Click...". If feeling brave you can also do:

[ $[ $RANDOM % 6 ] == 0 ] && echo 'Bang!' && a really killer command || echo 'Click...'
fortune -s | cowsay -f tux | lolcat -s 64
make your terminal interactive and fun
transfer() { basefile=$(basename "$1" | sed -e 's/[^a-zA-Z0-9._-]/-/g');curl --progress-bar --upload-file "$1" "https://transfer.sh/$basefile"|xsel --clipboard;xsel --clipboard ; }
2016-03-20 19:38:48
User: leftyfb
Functions: basename sed




access to the internet(http://transfer.sh)

This is an alias utilizing the transfer.sh service to make sharing files easier from the command line. I have modified the alias provided by transfer.sh to use xsel to copy the resulting URL to the clipboard.

The full modified alias is as follows since commandlinefu only allows 255 characters:

transfer() { if [ $# -eq 0 ]; then echo "No arguments specified. Usage:\necho transfer /tmp/test.md\ncat /tmp/test.md | transfer test.md"; return 1; fi if tty -s; then basefile=$(basename "$1" | sed -e 's/[^a-zA-Z0-9._-]/-/g'); curl --progress-bar --upload-file "$1" "https://transfer.sh/$basefile" |xsel --clipboard; else curl --progress-bar --upload-file "-" "https://transfer.sh/$1" |xsel --clipboard ; fi; xsel --clipboard; }

rsync -avxHAXW --info=progress2 /old-disk /new-disk/
awk -F= '/^(psk|id)/{print $2}' /etc/NetworkManager/system-connections/"$(iwgetid -r)"
exa -glhrSuU -s size --group-directories-first -@ | less -R
2016-02-27 17:19:43
User: wires
Functions: less size
Tags: ls color exa

nothing fancy

`ls` alternative `exa`, with most info printed and passed through less with the `-R` (raw) option, to preserve colour output https://github.com/ogham/exa

You can add or remove `-@` to print extended attributes for files that have them.

echo /etc/*_ver* /etc/*-rel*; cat /etc/*_ver* /etc/*-rel*
2016-02-19 12:12:38
User: sxiii
Functions: cat echo

Just run this command and it will printout all the info available about your current distribution and package management system.

blank=$(mktemp -d); rsync --delete "$blank/" "bigdir/"; rmdir "$blank"
2016-02-15 11:23:15
User: Natureshadow
Functions: mktemp rmdir rsync
Tags: rsync rm

rsync'ing an empty directory over a directory to be deleted recursively is much faster than using rm -rf, for various reasons. Relevant only for directories with really a lot of files.

egrep -v '^\s*($|#)' $(git grep -l '#!/bin/.*sh' *) | wc -l
2016-02-15 11:15:48
User: Natureshadow
Functions: egrep grep wc
Tags: git grep count code

Uses git grep for speed, relies on a valid she-bang, ignores leading whitespace when stripping comments and blank lines

ps -eo pmem,comm | grep java | awk '{sum+=$1} END {print sum " % of RAM"}'
2016-02-10 09:00:56
User: bugmenot
Functions: awk grep ps sum

This command will add up RAM usage of all processes whose name contains "java" and output the sum of percentages in HRF. Also, unlike the original #15430, it wont fail on processes with a usage of >9.9%.

Pleases note that this command wont work reliably in use cases where a significant portion of processes involved are using less than 0.1% of RAM, because they will be counted as "0", even though a great number of them could add up to significant amounts.

adb shell "screencap -p | base64" | sed 's/\r$//' | base64 -d | display
2016-02-07 18:46:35
User: T4b
Functions: sed

Dependencies on phone: adb access, screencap command, base64 command.

Dependencies on computer: adb, sed, base64, display (from imagemagick, but can substitute other image viewer which reads from stdin).

This should work around adb stupidies (i.e. that it replaces \n with \r\n) with base64.

sudo system-image-cli --switch ubuntu-touch/rc-proposed/ubuntu --build 0
2016-02-07 18:24:28
User: bugmenot
Functions: sudo
Tags: ubuntu-phone

Get the latest and hopefully greatest to test out on the Ubuntu Phone - sometimes broken but always interesting. https://developer.ubuntu.com/en/start/ubuntu-for-devices/image-channels/

sudo mount -o remount,rw /
2016-02-07 17:57:19
User: bugmenot
Functions: mount sudo

Warning this will allow you to write to the system image on the phone, not recommended. But sometimes useful.

gsettings reset com.canonical.Unity.Dash favorite-scopes
2016-02-07 17:50:19
User: bugmenot
Functions: reset

To fix this bug: https://bugs.launchpad.net/ubuntu/+source/unity8/+bug/1389698

fortune | cowsay -f sodomized-sheep
wget https://open.uappexplorer.com/api/download/openstore.openstore-team/openstore.*_*_armhf.click && pkcon install-local --allow-untrusted openstore.*_*_armhf.click
2016-02-04 14:24:46
User: bugmenot
Functions: wget

This will download and install the latest version of the open store on the ubuntu phone, this store includes unconfined applications such as the TweakGeek and the Ubuntu Touch Tweak Tool. You can see the install instructions from here: https://open.uappexplorer.com/docs#install

ssh-keygen -b 4048 -t rsa -C "comment"
2016-02-03 09:37:39
User: erez83
Functions: ssh ssh-keygen
Tags: ssh centos

Generating ssh key

then need to copy public key in to /root/.ssh/authorized_keys

$if [[ "$(sleep 1 | telnet -c <host> <port> 2>&1 | grep '^SSH')" == SSH* ]]; then <command when up>; else <command when down>; fi;
2016-02-02 13:06:51
User: paulera

This command telnet and and looks for a line starting with "SSH" - works for OpenSSH since the SSH banner is something like "SSH-2.0-OpenSSH_6.0p1 Debian-4+deb7u3". Then it triggers an action accordingly.

It can be packed as a script file to echo 0/1 indicating the SSH service availability:

if [[ "$(sleep 1 | telnet -c <host> <port> 2>&1 | grep '^SSH')" == SSH* ]]; then echo 1; else echo 0; fi;

Alternative uses:

Trigger an action when server is UP (using &&):

[[ "$(sleep 1 | telnet -c <host> <port> 2>&1 | grep '^SSH')" == SSH* ]] && <command when up>

Trigger an action when server is DOWN (using ||):

[[ "$(sleep 1 | telnet -c <host> <port> 2>&1 | grep '^SSH')" == SSH* ]] || <command when down>