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.

Universal configuration monitoring and system of record for IT.
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

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!
Hide

Top Tags

Hide

Functions

Hide

Credits

Commands by DaveQB from sorted by
Terminal - Commands by DaveQB - 9 results
watch -n1 'date "+%T"'
2011-02-16 00:33:51
User: DaveQB
Functions: watch
4

A console clock with the current time.

df /media/mountpoint |egrep -o '^[/a-z0-9]*'
2011-01-24 21:14:55
User: DaveQB
Functions: df egrep
Tags: grep,df
-1

Shorter way to find the device for a given mountpoint

sed '/'"<opening tag>"'/,/'"<closing tag>"'/{/'"<closing tag>"'/d;p};d' "<file>"
find * -maxdepth 1 -type f ! -name abc -delete
2010-07-19 00:29:59
User: DaveQB
Functions: find
5

Finds all files in the current directory and deletes them besides file called "abc"

echo "${1}" | egrep '^[[:digit:]]*$' ; if [ "$?" -eq 0 ] ; then sed -i "${1}"d $HOME/.ssh/known_hosts ; else printf "\tYou must enter a number!\n\n" ; exit 1 ; fi
2010-07-11 23:09:11
User: DaveQB
Functions: echo egrep exit printf sed
Tags: sed
-13

I have this as a file called deletekey in my ~/bin.

Makes life a little easier.

free -m | awk '/buffer/ {print $4}'
2010-06-27 23:30:27
User: DaveQB
Functions: awk free
Tags: ram free
3

Here we instead show a more real figure for how much free RAM you have when taking into consideration buffers that can be freed if needed.

Unix machines leave data in memory but marked it free to overwrite, so using the first line from the "free" command will mostly give you back a reading showing you are almost out of memory, but in fact you are not, as the system can free up memory as soon as it is needed.

I just noticed the free command is not on my OpenBSD box.

cd /some/empty/folder/website_diffs/sitename && wget -N http://domain.com/ 2>&1 |grep -q "o newer" || printf "Sites web page appears to have updated.\n\nSuggest you check it out.\n\n"|mail -s "Sites page updated." david@email.com
2010-05-09 07:28:42
User: DaveQB
Functions: cd grep mail printf wget
2

A cronjob command line to email someone when a webpages homepage is updated.

date +%A | cut -c $(( $(date +%A | wc -c) - 1 ))
2010-04-07 00:23:15
User: DaveQB
Functions: cut date wc
Tags: bash echo cut date wc
0

A command to find out what the day ends in. Can be edited slightly to find out what "any" output ends in.

NB: I haven't tested with weird and wonderful output.

INPUT=<input_video> && ffmpeg -i "$INPUT" -vn -f wav - | oggenc -o ${INPUT%%.*}.ogg -
2009-05-19 07:57:43
User: DaveQB
1

Assumes you have ffmpeg and oggenc.

Similar to other scripts here, but this time outputting to Ogg Vorbis.

I added the variable assignment for a nice output name.

This is part of an interactive bash script I have with a few little multimedia tasks in it.

http://www.dward.us/software/VSAK.sh