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2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.

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Commands using tr from sorted by
Terminal - Commands using tr - 278 results
openssl rand -hex 1 | tr '[:lower:]' '[:upper:]' | xargs echo "obase=2;ibase=16;" | bc | cut -c1-6 | sed 's/$/00/' | xargs echo "obase=16;ibase=2;" | bc | sed "s/$/:$(openssl rand -hex 5 | sed 's/\(..\)/\1:/g; s/.$//' | tr '[:lower:]' '[:upper:]')/"
2013-10-22 08:40:46
User: 4fd
Functions: bc cut echo sed tr xargs

I did not come up with this one myself, but found this somewhere else several months ago.

t2s() { wget -q -U Mozilla -O $(tr ' ' _ <<< "$1"| cut -b 1-15).mp3 "http://translate.google.com/translate_tts?ie=UTF-8&tl=en&q=$(tr ' ' + <<< "$1")"; }
2013-10-16 23:29:59
User: snipertyler
Functions: cut tr wget

Usage: t2s 'How are you?'

Nice because it automatically names the mp3 file up to 15 characters

Modified (uses bash manip instead of tr)

t2s() { wget -q -U Mozilla -O $(cut -b 1-15

(date "+%d-%m-%Y %H:%M:%S";curl -s --interface lo:1 ifconfig.me| xargs -t geoiplookup 2>&1)|sed -e 's/geoiplookup/IP:/g' -e 's/GeoIP Country Edition/Country/g'|tr -s "\n" " "|sed 'a\ '
2013-10-07 15:28:55
User: guerito
Functions: date sed tr xargs

My first command :) I made this command to log public addresses of a virtual interface who connects random VPN servers around the world.

shuf /usr/share/dict/words |grep "^[^']\{3,6\}$" |head -n4 | sed -e "s/\b\(.\)/\u\1/g" | tr -d '\n'; echo
2013-09-06 03:05:31
User: chijonutor
Functions: grep head sed tr
Tags: tr xkcd shuf

Took one of the samples, added capitalization and removes in between spaces.

The final "echo" is just for readability.


shuf -n4 /usr/share/dict/words | tr '\n' ' '
sudo /usr/sbin/exim -bp | sed -n '/\*\*\* frozen \*\*\*/,+1!p' | awk '{print $1}' | tr -d [:blank:] | grep @ | sort | uniq -c | sort -n
curl -s http://www.reddit.com/user/$USER/about.json | tr "," "\n" | grep "link_karma" | tr ": " "\n" | grep -E "[0-9]+" | sed s/"^"/"Link Karma: "/
2013-05-13 15:36:59
User: iiAtlas
Functions: grep sed tr
Tags: curl

Replace $USER with the username of the Reddit user in question. To get comment karma instead run...

curl -s http://www.reddit.com/user/$USER/about.json | tr "," "\n" | grep "comment_karma" | tr ": " "\n" | grep -E "[0-9]+" | sed s/"^"/"Comment Karma: "/
echo lowercaseword | tr '[a-z]' '[A-Z]'
svn ls -R | egrep -v -e "\/$" | tr '\n' '\0' | xargs -0 svn blame | awk '{print $2}' | sort | uniq -c | sort -nr
2013-04-10 19:37:53
User: rymo
Functions: awk egrep ls sort tr uniq xargs
Tags: svn count

make usable on OSX with filenames containing spaces. note: will still break if filenames contain newlines... possible, but who does that?!

rsync --progress user@host:/path/to/source /path/to/target/ | stdbuf -oL tr '\r' '\n' >> rsyncprogress.txt
2013-03-26 11:06:45
User: MessedUpHare
Functions: rsync tr

This line unbuffers the interactive output of rsync's --progress flag

creating a new line for every update.

This output can now be used within a script to make actions (or possibly piped into a GUI generator for a progress bar)

tr -dc 'A-Za-z0-9!@#$%^&*' < /dev/urandom | fold -w 12 | head -n 1
tr '[:upper:]' '[:lower:]' < input.txt > output.txt
dd if=/dev/urandom | tr -d -c [:print:] | tr -d " " | dd count=1 bs=20 2> /dev/null; echo
2013-03-01 22:42:29
User: Progent
Functions: dd tr

It will produce passwords with length of 20 printable characters within a reasonable time.

For shorter or longer passwords just change the 20 in bs=20 to something more convenient.

To create only alpha numeric passwords change [:print:] to [:alnum:]

nmap -sP 192.168.0.* | grep Host | tr "(" ")" | cut -d\) -f2
while true; do (date | tr "\n" ";") && ping -q -c 1 www.google.com|tail -1|cut -d/ -f5 ;sleep 1; done >> uptime.csv
2013-02-06 22:06:09
User: fanchok
Functions: cut date ping sleep tail tr

Used in OS X.

tr "\n" ";"

may be replaced by

echo ";"

with linux versions of date.

I reused

ping -q -c 1 www.google.com|tail -1|cut -d/ -f5

dd if=/dev/zero of=T bs=1024 count=10240;mkfs.ext3 -q T;E=$(echo 'read O;mount -o loop,offset=$O F /mnt;'|base64|tr -d '\n');echo "E=\$(echo $E|base64 -d);eval \$E;exit;">F;cat <(dd if=/dev/zero bs=$(echo 9191-$(stat -c%s F)|bc) count=1) <(cat T;rm T)>>F
2013-01-31 01:38:30
User: rodolfoap

This is just a proof of concept: A FILE WHICH CAN AUTOMOUNT ITSELF through a SIMPLY ENCODED script. It takes advantage of the OFFSET option of mount, and uses it as a password (see that 9191? just change it to something similar, around 9k). It works fine, mounts, gets modified, updated, and can be moved by just copying it.


The file is composed of three parts:

a) The legible script (about 242 bytes)

b) A random text fill to reach the OFFSET size (equals PASSWORD minus 242)

c) The actual filesystem

Logically, (a)+(b) = PASSWORD, that means OFFSET, and mount uses that option.

PLEASE NOTE: THIS IS NOT AN ENCRYPTED FILESYSTEM. To improve it, it can be mounted with a better encryption script and used with encfs or cryptfs. The idea was just to test the concept... with one line :)

It applies the original idea of http://www.commandlinefu.com/commands/view/7382/command-for-john-cons for encrypting the file.

The embedded bash script can be grown, of course, and the offset recalculation goes fine. I have my own version with bash --init-file to startup a bashrc with a well-defined environment, aliases, variables.

ls -l /dev/disk/by-id | egrep ata-.*`hdparm -i /dev/sda | grep SerialNo | sed 's/.*SerialNo=//' | tr -d "\n"`.*sda$ | sed -e 's/.*ata-/ata-/' -e 's|[ ].*||' | tr -d "\n"
2013-01-07 10:20:25
Functions: egrep grep ls sed tr
Tags: Ubuntu

This was tested on Ubuntu 12.04 (Precise) LTS Server. It returns the name of the symlink within /dev/disk/by-id for the physical drive you specify. Change /dev/sda to the one you want, and replace ata- with scsi- or the appropriate type for your drive.

I used this to pre-configure grub-pc during a non-interactive install because I had to tell it which disk to install grub on, and physical disks don't have a UUID such as that blkid provides.

tr -s ' \t' <1.txt >2.txt
2012-12-19 07:36:00
User: knoppix5
Functions: tr

Remove empty lines additionally:

tr -s ' \t\n' <1.txt >2.txt

identical with:

tr -s '[:space:]' <1.txt >2.txt

To "clean perfectly" a text or code file, You can combine this command with

another one:

while read l; do echo -e "$l"; done <1.txt >2.txt

(= remove all leading and trailing spaces or tabs from all lines of a text file)

export DISPLAY=$(tr '\000' '\n' < /proc/`pidof Xorg`/cmdline | egrep '^:[0-9]+')
2012-12-18 07:26:16
User: oernii2
Functions: egrep export tr

Not always does Xorg run on :0. For times like those, this script allows you to find out which it is.

dig @resolver1.opendns.com myip.opendns.com | grep ^myip.opendns.com | tr '\t' : | cut -d: -f5
cd ~/.msf4/loot && cat *mscache* | cut -d '"' -f 2,4 | sed s/\"/\:/g | tr -cd '\11\12\40-\176' | grep -v Username | cut -d : -f 1,2 | awk -F':' '{print $2,$1}' | sed 's/ /:/g' > final.dcc.hash
tr -dc '[:print:]' < <file>
2012-11-22 06:29:26
User: seb1245
Functions: tr
Tags: printing tr

tr has some predefined sets of characters that are more convenient to use than characters codes

cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 18 | head -1 | python -c "import sys,crypt; stdin=sys.stdin.readline().rstrip('\n'); print stdin;print crypt.crypt(stdin)"
2012-11-09 00:40:22
User: cnyg
Functions: cat fold head python tr

Generate a 18 character password from character set a-zA-Z0-9 from /dev/urandom, pipe the output to Python which prints the password on standard out and in crypt sha512 form.

tr -d '\r' < <input> > <output>
echo "your string here" | tr '\!-~' 'P-~\!-O'
2012-11-06 12:49:00
User: DevEd
Functions: echo tr

This command will encode a string using the ROT47 cipher.