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.

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:

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

Tags

Hide

Functions

Commands tagged uuid from sorted by
Terminal - Commands tagged uuid - 9 results
system_profiler SPHardwareDataType | awk '/UUID/ { print $3; }'
2014-07-25 06:54:40
Functions: awk
0

Gets the Hardware UUID of the current machine using system_profiler.

echo "import uuid\nimport sys\nsys.stdout.write(str(uuid.uuid4()))" | python
2014-07-23 07:43:01
User: tippy
Functions: echo
Tags: python uuid
0

piped this to pbcopy (OSX only) you got a uuid in the pasteboard

ls /dev/disk* | xargs -n 1 -t sudo zdb -l | grep GPTE_
2012-10-06 20:19:45
User: grahamperrin
Functions: grep ls sudo xargs
1

Show the UUID-based alternate device names of ZEVO-related partitions on Darwin/OS X. Adapted from the lines by dbrady at http://zevo.getgreenbytes.com/forum/viewtopic.php?p=700#p700 and following the disk device naming scheme at http://zevo.getgreenbytes.com/wiki/pmwiki.php?n=Site.DiskDeviceNames

lsblk -o NAME,TYPE,FSTYPE,LABEL,SIZE,MODEL,MOUNTPOINT
2012-09-12 15:30:25
User: BasketCase
2

Shows all block devices in a tree with descruptions of what they are.

blkid -c /dev/null
2012-09-12 13:34:41
User: mhs
2

`blkid` is an interface to libuuid - it can read Device Mapper, EVMS, LVM, MD, and regular block devices.

-c /dev/null - Do not use cached output from /etc/blkid.tab or /etc/blkid/blkid.tab (RHEL)

-i - Display I/O Limits (aka I/O topology) information (not available in RHEL)

-p - Low-level superblock probing mode (not available in RHEL)

UUID="63b726a0-4c59-45e4-af65-bced5d268456"; echo ${UUID//-/}
2011-11-22 22:49:30
User: flatcap
Functions: echo
0

Remove the dashes from a UUID using bash search and replace.

TEST_UUID=$(blkid /dev/sda6 | sed -rn "s/^.*UUID=\"([a-z0-9]{8}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{12})\".*/\1/p")
blkid /dev/sda7
2010-09-05 12:20:45
User: lineak
Tags: partition uuid
7

Shows the UUID of the given partition (here /dev/sda7). Doesn't need to be root.

printf $(( echo "obase=16;$(echo $$$(date +%s%N))"|bc; ip link show|sed -n '/eth/ {N; p}'|grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'|head -c 17 )|tr -d [:space:][:punct:] |sed 's/[[:xdigit:]]\{2\}/\\x&/g')|sha1sum|head -c 32; echo
2010-07-14 14:04:53
User: camocrazed
Functions: echo grep head link printf sed tr
Tags: uuid
0

first off, if you just want a random UUID, here's the actual command to use:

uuidgen

Your chances of finding a duplicate after running this nonstop for a year are about the same as being hit by a meteorite before finishing this sentence

The reason for the command I have is that it's more provably unique than the one that uuidgen creates. uuidgen creates a random one by default, or an unencrypted one based on time and network address if you give it the -t option.

Mine uses the mac address of the ethernet interface, the process id of the caller, and the system time down to nanosecond resolution, which is provably unique over all computers past, present, and future, subject to collisions in the cryptographic hash used, and the uniqueness of your mac address.

Warning: feel free to experiment, but be warned that the stdin of the hash is binary data at that point, which may mess up your terminal if you don't pipe it into something. If it does mess up though, just type

reset