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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



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

Commands using tr from sorted by
Terminal - Commands using tr - 287 results
tr '[A-Za-z]' '[N-ZA-Mn-za-m]'
2010-04-30 10:07:27
User: hackerb9
Functions: tr

I noticed some spammer posted an advertisement here for "not bad" encryption. Unfortunately, their software only runs under Microsoft Windows and fails to work from the commandline. My shell script improves upon those two aspects, with no loss in security, using the exact same "military-grade" encryption technology, which has the ultra-cool codename "ROT-13". For extra security, I recommend running ROT-13 twice.

echo "$1" | xxd -p | tr '0-9' '5-90-6'; echo "$1" | tr '0-9' '5-90-6' | xxd -r -p
2010-04-27 03:08:47
User: IsraelTorres
Functions: echo tr

This is N5 sorta like rot13 but with numbers only.


echo "$1" | xxd -p | tr '0-9' '5-90-6'


echo "$1" | tr '0-9' '5-90-6' | xxd -r -p

echo StrinG | tr '[:upper:]' '[:lower:]'
tr -d "\n\r" | grep -ioEm1 "<title[^>]*>[^<]*</title" | cut -f2 -d\> | cut -f1 -d\<
cat /etc/apache2/sites-enabled/* | egrep 'ServerAlias|ServerName' | tr -s ' ' | sed 's/^\s//' | cut -d ' ' -f 2 | sed 's/www.//' | sort | uniq
2010-04-08 15:50:34
User: chronosMark
Functions: cat cut egrep sed sort tr

Get a list of all the unique hostnames from the apache configuration files. Handy to see what sites are running on a server. A slightly shorter version.

cat /etc/apache2/sites-enabled/* | egrep 'ServerAlias|ServerName' | tr -s " " | sed 's/^[ ]//g' | uniq | cut -d ' ' -f 2 | sed 's/www.//g' | sort | uniq
2010-04-08 08:51:17
User: chronosMark
Functions: cat cut egrep sed sort tr uniq

Get a list of all the unique hostnames from the apache configuration files. Handy to see what sites are running on a server.

printf "%`tput cols`s"|tr ' ' '#'
function wherepath () { for DIR in `echo $PATH | tr ":" "\n" | awk '!x[$0]++ {print $0}'`; do ls ${DIR}/$1 2>/dev/null; done }
2010-04-02 20:32:36
User: mscar
Functions: awk ls tr
Tags: find locate PATH

The wherepath function will search all the directories in your PATH and print a unique list of locations in the order they are first found in the PATH. (PATH often has redundant entries.) It will automatically use your 'ls' alias if you have one or you can hardcode your favorite 'ls' options in the function to get a long listing or color output for example.


'whereis' only searches certain fixed locations.

'which -a' searches all the directories in your path but prints duplicates.

'locate' is great but isn't installed everywhere (and it's often too verbose).

seq -s'#' 0 $(tput cols) | tr -d '[:digit:]'
2010-04-01 09:06:44
User: jgc
Functions: seq tput tr
Tags: seq tr tput

Print a row of characters across the terminal. Uses tput to establish the current terminal width, and generates a line of characters just long enough to cross it. In the example '#' is used.

It's possible to use a repeating sequence by dividing the columns by the number of characters in the sequence like this:

seq -s'~-' 0 $(( $(tput cols) /2 )) | tr -d '[:digit:]'


seq -s'-~?' 0 $(( $(tput cols) /3 )) | tr -d '[:digit:]'

You will lose chararacters at the end if the length isn't cleanly divisible.

printf "%.50d" 0 | tr 0 -
seq -s" " -50 -1 | tr -dc -
2010-03-25 06:00:24
Functions: seq tr

Get there by going backwards and forgetting the numbers.

tr '\n' '\t' < inputfile
tr '\t' '\n' < inputfile
grep current_state= /var/log/nagios/status.dat|sort|uniq -c|sed -e "s/[\t ]*\([0-9]*\).*current_state=\([0-9]*\)/\2:\1/"|tr "\n" " "
cat /proc/$(lsof -ti:8888)/cmdline | tr "\0" " "
cat authorized_keys_with_broken_lines | sed 's,^ssh,%ssh,' | tr '\n' '\0' | tr '%' '\n' | sed '1d' | sed "/^$/d" > authorized_keys
2010-02-19 08:32:35
User: pepin
Functions: cat sed tr

when someone mail you his ssh public key, and the lines are broken with '\n', you can reconstruct a new file with one key by line with this command.

curl -s -u $username:$password | grep '<td>.* </td>' | sed 's|\t<td>\(.*\) </td>\r|\1|' | tr '\n' ';' | sed 's/\([^;]*\);\([^;]*\);/\2\t\1\n/g'
2010-02-16 02:27:11
User: matthewbauer
Functions: grep sed tr

Will create a sample etc host file based on your router's dhcp list.

Now I know this won't work on most routers, so please don't downvote it just because it doesn't work for you.

username=matthewbauer; curl -s http://www.commandlinefu.com/commands/by/$username/json | tr '{' '\n' | grep -Eo ',"votes":"[0-9\-]+","' | grep -Eo '[0-9\-]+' | tr '\n' '+' | sed 's/+$/\n/' | bc
2010-02-14 04:32:36
User: matthewbauer
Functions: grep sed tr

This will calculate the your commandlinefu votes (upvotes - downvotes).

Hopefully this will boost my commandlinefu points.

cat file | tr '\n' ''
curl -s -H "Authorization: GoogleLogin auth=$auth" "http://www.google.com/reader/api/0/unread-count?output=json" | tr '{' '\n' | sed 's/.*"count":\([0-9]*\),".*/\1/' | grep -E ^[0-9]+$ | tr '\n' '+' | sed 's/\(.*\)+/\1\n/' | bc
2010-02-11 00:42:57
User: matthewbauer
Functions: grep sed tr

Get Google Reader unread count from the command line.

You'll have to define your auth token with $auth

Or use:

curl -s -H "Authorization: GoogleLogin auth=$(curl -sd "Email=$email&Passwd=$password&service=reader" https://www.google.com/accounts/ClientLogin | grep Auth | sed 's/Auth=\(.*\)/\1/')" "http://www.google.com/reader/api/0/unread-count?output=json" | tr '{' '\n' | sed 's/.*"count":\([0-9]*\),".*/\1/' | grep -E ^[0-9]+$ | tr '\n' '+' | sed 's/\(.*\)+/\1\n/' | bc
wget -q -U busybox -O- "http://www.google.com/search?ie=UTF8&q=define%3A$1" | tr '<' '\n' | sed -n 's/^li>\(.*\)/\1\n/p'
2010-02-01 13:01:47
User: hackerb9
Functions: sed tr wget

This is a minimalistic version of the ubiquitious Google definition screen scraper. This version was designed not only to run fast, but to work using BusyBox. BusyBox is a collection of basic Unix tools that have been compiled into a single binary to save space on tiny installations of Unix. For example, although my phone doesn't have perl or the GNU utilities, it does have BusyBox's stripped down versions of wget, tr, and sed. It turns out that those tools suffice for many tasks.

Known Bugs: This script does not handle HTML entities at all. I don't think there's an easy way to do that within BusyBox, but I'd love to see it if someone could do it. Also, this script can only define a single word, not phrases. (Well, you could if you typed in %20, but that'd be gross.) Lastly, this script does not show the URL where definitions were found. Given the randomness of the Net, that last bit of information is often key.

echo $(( $( cat count.txt | tr "\n" "+" | xargs -I{} echo {} 0 ) ))
2010-01-27 10:02:30
User: glaudiston
Functions: cat echo tr xargs

if you, like me, do not have the numsum, this way can do the same.

paste -d "." <(curl http://.../dist.female.first http://.../dist.male.first | cut -d " " -f 1 | sort -uR) <(curl http://..../dist.all.last | cut -d " " -f 1 | sort -R | head -5163) | tr "[:upper:]" "[:lower:]" | sed [email protected]/g'
2010-01-21 19:52:28
User: connorsy
Functions: cut head paste sed sort tr

** Replace the ... in URLS with:


Couldn't fit in 256

Created on Ubuntu 9.10 but nothing out of the ordinary, should work anywhere with a little tweaking. 5163 is the number of unique first names you get when combine the male and female first name files from. http://www.census.gov/genealogy/www/data/1990surnames/names_files.html

port=8888;pid=$(lsof -Pan -i tcp -i udp | grep ":$port"|tr -s " " | cut -d" " -f2); ps -Afe|grep "$pid"|grep --invert-match grep | sed "s/^\([^ ]*[ ]*\)\{7\}\(.*\)$/\2/g"
2010-01-11 17:49:22
User: glaudiston
Functions: cut grep ps sed tr

A way not so simple but functional for print the command for the process that's listening a specific port.

I got the pid from lsof because I think it's more portable but can be used netstat

netstat -tlnp
printf "%50s\n"|tr ' ' -
2010-01-07 08:49:46
User: rodolfoap
Functions: printf tr

Better -and faster- using bash printf.