Hide

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

OpenID

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

Hide

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)
» commands matching random password

Hide

News

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.

Hide

Functions

Hide

Credits

Site by David Winterbottom (user root).

Commands matching random password

Terminal - Commands matching random password - 47 results

env LC_CTYPE=C tr -dc "a-zA-Z0-9-_\$\?" < /dev/urandom | head -c 10

2011-02-22 17:09:44

User: aerickson

Functions: env head tr

Tags: password random generate mac os x

Up
Down

generate random password (works on Mac OS X)

Prepending

env LC_CTYPE=C

fixes a problem with bad bytes in /dev/urandom on Mac OS X

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

jot 4 | awk '{ print "wc -l /usr/share/dict/words | awk '"'"'{ print \"echo $[ $RANDOM * $RANDOM % \" $1 \"]\" }'"'"' | bash | awk '"'"'{ print \"sed -n \" $1 \"p /usr/share/dict/words\" }'"'"' | bash" }' | bash | tr -d '\n' | sed 's/$/\n/'

2011-08-16 00:26:56

User: fathwad

Functions: awk bash sed tr

Tags: tr xkcd

Up
Down

Generate an XKCD #936 style 4 word password

So I use OSX and don't have the shuf command. This is what I could come up with.

This command assumes /usr/share/dict/words does not surpass 137,817,948 lines and line selection is NOT uniformly random.

openssl rand 6 -base64

2011-10-05 14:24:41

User: Le_Jax

Up
Down

Generate Random Passwords

just change 6 to 9 or 12 or more (multiple of 3) to have bigger password

slpappasswd

2011-10-13 14:46:03

User: evolix

Tags: ldap password hash generate

Up
Down

Simply generate a password for userPassword in ldap

Permit to generate a password for userPassword in ldap.

Use ?slappasswd -g? to generate a random passowrd.

false; while [ $? != 0 ]; do apg -c /dev/urandom -n1 -E oOlL10 | egrep '^[[:alnum:]]+$'; done

2012-04-24 08:30:28

User: evolix

Functions: egrep false

Tags: password random generate apg

Up
Down

Generate random password, human readable with no special characters.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

pwgen 10 # generate a table of 10 character random passwords

2012-10-26 08:57:47

User: mpb

Up
Down

generate a random 10 character password

Generate a table of random 10 character passwords

tr -dc 'a-zA-Z0-9' < /dev/urandom | head -c10

2009-12-01 14:22:20

User: Phil

Functions: head tr

-1

Up
Down

generate random password

A slightly shorter version. Also doesn't put a return character at the end of the password

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

RANGE=`wc -l /usr/share/dict/words | sed 's/^$[0-9]*$ .*$/\1/'`; for i in {1..4}; do let "N = $RANDOM % $RANGE"; sed -n -e "${N}p" /usr/share/dict/words | tr -d '\n'; done; RANGE=100; let "N = $RANDOM % $RANGE"; echo $N

2011-08-16 07:04:57

User: unixmonkey24597

Functions: echo sed tr

Tags: bash xkcd

-1

Up
Down

creates a xkcd #936-style password

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

awk 'BEGIN {srand} /^[a-z]{4,8}$/ {w[i++]=$0} END {while (j++<4) print w[int(rand*i)]}' /usr/share/dict/words

2011-08-18 02:09:42

User: putnamhill

Functions: awk

Tags: awk xkcd

-1

Up
Down

Generate an XKCD #936 style 4 word password

If you do not have shuf or an -R option in sort, you can fall back on awk. This provides maximum portability IMO. The command first collects words from the dictionary that match the criteria - in this case: lower case words with no punctuation that are 4 to 8 characters long. It then prints 4 random entries. I decided to print each word on a separate line to improve readability.

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

genpassdeep() { cat /dev/urandom | tr -dc [:alnum:] | head -c64 | sha256deep; echo; }

2012-11-09 00:33:22

User: malathion

Functions: cat head tr

Tags: Security password sha256 /dev/urandom md5deep

-1

Up
Down

Create a secure password using /dev/urandom and sha256

/dev/urandom relies on operator input to set the random seed. By itself, this may not contain enough random bits to produce high entropy output, especially if the system was recently restarted. Therefore, key stretching through a hash reduces the risk of using low-entropy output as a security key.

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

-1

Up
Down

Create random password in reasonable time

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:]

head -c $((<pw-lenght>-2)) /dev/urandom | uuencode -m - | sed -e '1d' -e '3d' | sed -e 's/=.*$//g'

2009-03-24 20:05:16

User: P17

Functions: head sed uuencode

-2

Up
Down

Creates a random passwort from /dev/urandom [0-9A-za-z]

Replace < pw-length > with the desired password-length.

The password-length is not always correct, but wayne...

Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

tr -dc 'a-zA-Z0-9' < /dev/urandom | fold -w 10 | sed 1q

2009-12-01 11:14:16

User: unixmonkey7109

Functions: fold sed tr

-2

Up
Down

generate random password

no need that useless cat.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

makepasswd --char=32

2010-09-29 06:01:32

User: zed

Tags: password makepasswd

-2

Up
Down

Generate a random password 32 characters long :)

A more robust password creation utility

# Create passwords in batch

makepasswd --char=32 --count=10

# To learn more about the options you can use

man makepasswd

genpassdeep() { cat /dev/urandom | tr -dc [:alnum:] | head -c64 | whirlpooldeep; echo; }

2012-11-11 19:19:29

User: malathion

Functions: cat head tr

Tags: Security password sha256 /dev/urandom md5deep whirlpool

-2

Up
Down

Create a secure password using /dev/urandom and whirlpool

2009-12-29 17:18:25

User: _eirik

Functions: cut tr

Tags: Security openssl password

-3

Up
Down

generate random password

eliminates "l" and "o" characters change length by changing 'x' here: cut -c 1-x

mkpasswd() { head -c $(($1)) /dev/urandom | uuencode - | sed -n 's/.//;2s/$.\{'$1'\}$.*/\1/p' ;}

2009-11-19 14:27:52

User: taliver

Functions: head sed uuencode

-3

Up
Down

Random password generating function

This uses urandom to produce a random password. The random values are uuencoded to ensure only printable characters. This only works for a number of characters between 1 and 60.

pwgen 30

2010-09-28 12:49:10

User: flojo

Tags: tr fold

-3

Up
Down

Generate a random password 30 characters long

pwgen 30

date | md5sum

2010-09-28 20:20:17

User: yababay

Functions: date

Tags: tr fold

-4

Up
Down

Generate a random password 32 characters long :)

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

perl -e 'print crypt("PASSWORD",int(rand(128))).$/;'

2010-09-30 12:58:39

User: cicatriz

Functions: perl

-4

Up
Down

Creating a pseudo-random password

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

for i in {21..79};do echo -e "\x$i";done | tr " " "\n" | shuf | tr -d "\n"

2011-04-14 01:43:40

User: hunterm

Functions: echo tr

Tags: echo password tr for shuf for loop generator alpha symbols digit

-4

Up
Down

Random Password Generator (uses all chars, no repeated chars)

Generates a password using symbols, alpha, and digits. No repeating chars.

dd bs=1 count=32 if=/dev/random 2> /dev/null | md5 | grep -o '\w*'

2009-02-15 23:22:46

User: neW1

Functions: dd grep

-5

Up
Down

Generate random password

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate

< 1 2