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How to stop MAC Address via IPTables

edit the /etc/sysconfig/iptables file and try to work whit this: -A INPUT -i (interface) -m mac (mac address) -j ACCEPT/DROP
This is sample output - yours may be different.
2

-A INPUT -i eth1 -m mac ?mac 00:BB:77:22:33:AA -j ACCEPT

0disse0 · 2010-01-31 15:34:31 6
How to secure delete a file

Instead, install apt-get install secure-delete and you can use: -- srm to delete file and directory on hard disk -- smem to delete file in RAM -- sfill to delete "free space" on hard disk -- sswap to delete all data from swap
This is sample output - yours may be different.
6

shred -u -z -n 17 rubricasegreta.txt

0disse0 · 2010-01-31 15:24:54 6
How to use rysnc over ssh tunnel

Check the ssh_config file and set the variable: StrictHostKeyChecking no
This is sample output - yours may be different.
0

sshpass -p [password] rsync -av -e ssh [utente]@[indirizzoip]:/directorydacopiare/ /directorydidestinazione

0disse0 · 2010-01-31 15:21:14 3
a shell function to print a ruler the width of the terminal window.

A similar version for Bash that doesn't require cut and shortens the function in a few places. And it uses local variables. (similar to a version by eightmillion in a comment on the another version) Show Sample Output
This is sample output - yours may be different.
```
....^....|....^....|....^....|....^....|....^....|....^....|....^....|....^....|
12345678901234567890123456789012345678901234567890123456789012345678901234567890
```
2

ruler() { for s in '....^....|' '1234567890'; do w=${#s}; str=''; for (( i=1; i<=(COLUMNS + w) / $w; i=i+1 )); do str+=$s; done; str=${str:0:COLUMNS} ; echo $str; done; }

dennisw · 2010-01-31 05:55:00 5
grab all commandlinefu shell functions into a single file, suitable for sourcing.

Much simpler but not as many features as the alternative.
This is sample output - yours may be different.
2

curl -s http://www.commandlinefu.com/commands/browse/sort-by-votes/plaintext/[0-2400:25] | grep -oP "^\w+\ *{.*}"

matthewbauer · 2010-01-31 05:14:11 6

Facebook Email Scraper

(Apparently it is too long so I put it in sample output, I hope that is OK.) Run the long command (or put it in your .bashrc) in sample output then run: fbemailscraper YourFBEmail Password Voila! Your contacts' emails will appear. Facebook seems to have gotten rid of the picture encoding of emails and replaced it with a text based version making it easy to scrape! Needs curl to run and it was made pretty quickly so there might be bugs. Show Sample Output

fbemailscraper YourFBEmail Password

dabom · 2010-01-31 00:44:35 45

View the newest xkcd comic.

Add an alias to your .bashrc that allows you to issue the command xkcd to view (with gwenview) the newest xkcd comic... I know there are thousands of them out there but this one is at least replete with installer and also uses a more concise syntax... plus, gwenview shows you the downloading progress as it downloads the comic and gives you a more full featured viewing experience.
This is sample output - yours may be different.
-5

echo alias xkcd="gwenview `w3m -dump http://xkcd.com/|grep png | awk '{print $5}'` 2> /dev/null" >> .bashrc

GinoMan2440 · 2010-01-30 20:38:16 5
grab all commandlinefu shell functions into a single file, suitable for sourcing.

Each shell function has its own summary line, as a comment. If there are multiple shell functions with the same name, the function with the highest number of votes is put into the file. Note: added 'grep -v' to the end of the pipeline, to eliminate extraneous lines containing only '--'. Thanks to matthewbauer for pointing this out.
This is sample output - yours may be different.
8

export QQ=$(mktemp -d);(cd $QQ; curl -s -O http://www.commandlinefu.com/commands/browse/sort-by-votes/plaintext/[0-2400:25];for i in $(perl -ne 'print "$1\n" if( /^(\w+)/ )' *|sort -u);do grep -h -m1 -B1 $i *; done)|grep -v '^--' > clf.sh;rm -r $QQ

bartonski · 2010-01-30 19:47:42 40
Set a posix shell to echo all commands that it's about to execute, after all expansions have been done.

the 'set -x' mode can be exited by typing set +x Show Sample Output
This is sample output - yours may be different.
```
$ set -x
$ pwd
+ pwd
/tmp
$ asdf='x*'
+ asdf='x*'
$ cd ~
+ cd /home/tiger
$ find $OLDPWD -name "$asdf"
+ find /tmp -name 'x*'
...
```
3

set -x

bartonski · 2010-01-30 16:08:54 12
Define words and phrases with google.

This version works on Mac (avoids grep -P, adding a sed step instead, and invokes /usr/bin/perl with full path in case you have another one installed). Still requires that you install perl module HTML::Entities ? here's how: http://www.perlmonks.org/?node_id=640489
This is sample output - yours may be different.
7

define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Eo '<li>[^<]+'|sed 's/^<li>//g'|nl|/usr/bin/perl -MHTML::Entities -pe 'decode_entities($_)';}

gthb · 2010-01-30 13:08:03 14
Pipe music over netcat with mpg123

I think I picked this one up from Hak5 (yeah I know.. kinda lame)
This is sample output - yours may be different.
-3

#Client# cat "The Meters - People Say.mp3" | nc -vv 192.168.1.100 8080; #Server# nc -vv -l -s 192.168.1.100 -p 8080 | mpg123 -v -

Abiden · 2010-01-30 08:50:17 7
Copy the directory you want to specify a comma separated list of directories to copy.
This is sample output - yours may be different.
0

cp -arv ~/Documents/{foo,bar} --target-directory=~/buzz/

sugitaro · 2010-01-30 08:38:54 7
How to backup hard disk timely?

Creates files in $DATE and hardlinks existing files to $PREVDATE. Thus full backup in each directory. Only drawback is changed modification time. Recommend a wrapper script to determine $DATE and $PREVDATE. Works like a charm. (Dirvish handrolled)
This is sample output - yours may be different.
5

rsync -a --link-dest=/media/backup/$HOSTNAME/$PREVDATE '--exclude=/[ps][ry][os]' --exclude=/media/backup/$HOSTNAME / /media/backup/$HOSTNAME/$DATE/

danam · 2010-01-30 08:36:41 38
Rename duplicates from MusicBrainz Picard

Renames duplicates from MusicBrainz Picard, so you get the latest copy and not a bunch of duplicates. Show Sample Output
This is sample output - yours may be different.
```
`abba/forever_gold_(disc_1__abba_gold)/19-waterloo (1).mp3' -> `abba/forever_gold_(disc_1__abba_gold)/19-waterloo.mp3'
```
1

for i in */*/*$1$*; do mv -f "$i" "${i/ (1)}"; done

magenine · 2010-01-30 03:11:55 3
grep (or anything else) many files with multiprocessor power

Parallel does not suffer from the risk of mixing of output that xargs suffers from. -j+0 will run as many jobs in parallel as you have cores. With parallel you only need -0 (and -print0) if your filenames contain a '\n'. Parallel is from https://savannah.nongnu.org/projects/parallel/
This is sample output - yours may be different.
5

find . -type f | parallel -j+0 grep -i foobar

unixmonkey8046 · 2010-01-30 02:08:46 17
diff the same file in two directories.

This is useful when you're diffing two files of the same name in radically different directory trees. For example: Set path1='/some/long/convoluted/path/to/all/of/your/source/from/a/long/dead/machine' then path2='/local/version/of/same/file' then run the command. Much easier on the eyes when you're looking back across your command history, especially if you're doing the same diff over and over again.
This is sample output - yours may be different.
1

diff {$path1,$path2}/file_to_diff

bartonski · 2010-01-29 23:00:57 3
Mirror every lvol in vg00 in hp-ux 11.31

Create one mirror copy of every lvol in the vg00 just after a cold install of an HP-UX 11.31. Cna be used also for 11.23 but remember that in 11iv2 there is no agile view so the disk will be /dev/dsk/cxtxdxs2
This is sample output - yours may be different.
0

for i in in $(vgdisplay -v vg00 | grep "LV Name" | awk '{ print $3 };'); do; lvextend -m 1 $i /dev/disk/<here-goes-the-disk>; done

jreypo · 2010-01-29 22:43:07 3
Validating a file with checksum
This is sample output - yours may be different.
1

[ "c84fa6b830e38ee8a551df61172d53d7" = "$(md5sum myfile | cut -d' ' -f1)" ] && echo OK || echo FAIL

tuxilicious · 2010-01-29 21:46:26 4
Replace spaces in filenames with underscores

It's the rename-tool from debians perl-package.
This is sample output - yours may be different.
8

rename 's/ /_/g' *

tuxilicious · 2010-01-29 21:15:03 8
Replace spaces in filenames with underscores

I realize there's a few of these out there, but none exactly in this form, which seems the cleanest to me
This is sample output - yours may be different.
9

for f in *;do mv "$f" "${f// /_}";done

ethanmiller · 2010-01-29 19:57:16 9
test moduli file generated for openssh

this command test the moduli file generated by the command ssh-keygen -G /tmp/moduli-2048.candidates -b 2048 . The test can be long depend of your cpu power , around 5 minutes to 30 minutes
This is sample output - yours may be different.
1

ssh-keygen -T moduli-2048 -f /tmp/moduli-2048.candidates

eastwind · 2010-01-29 19:35:21 3
generate the moduli file for openssh if lost

if you lost your moduli file in openssh server side you need generate new one with this command then test if the number generated can be used with ssh-keygen -T moduli-2048 -f /tmp/moduli-2048.candidates
This is sample output - yours may be different.
0

ssh-keygen -G /tmp/moduli-2048.candidates -b 2048

eastwind · 2010-01-29 19:33:23 3
Validating a file with checksum

Makes sure the contents of "myfile" are the same contents that the author intended given the author's md5 hash of that file ("c84fa6b830e38ee8a551df61172d53d7").
This is sample output - yours may be different.
2

md5 myfile | awk '{print $4}' | diff <(echo "c84fa6b830e38ee8a551df61172d53d7") -

voidpointer · 2010-01-29 16:57:13 6
Netcat Relay

This is an example of using 3 hosts, in a netcat relay. first host connects to middle host 1 -> 2 Second hosts redirects to target host 1 -> 2 -> 3 I hope this makes sense.
This is sample output - yours may be different.
2

nc -vv $MIDDLEHOST 1234; ## nc -vv -l $IamMIDDLEHOST 1234 | nc $Targethost 1234;## nc -l $IamTargetHost 1234 -e /bin/bash;

Abiden · 2010-01-29 16:45:39 140
Triangular Number
This is sample output - yours may be different.
0

echo $(echo $(seq $MIN $MAX) | sed 's/ /+/g') | bc -l

Abiden · 2010-01-29 16:41:07 3
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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.

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send tweets to twitter (and get user details)

great for outputting tweets from cron jobs and batch scripts

Outputs a 10-digit random number

Generate MD5 of string and output only the hash checksum in a readable format

Generates the md5 hash, without the trailing " -" and with the output "broken" into pairs of hexs.

Job Control

You're running a script, command, whatever.. You don't expect it to take long, now 5pm has rolled around and you're ready to go home... Wait, it's still running... You forgot to nohup it before running it... Suspend it, send it to the background, then disown it... The ouput wont go anywhere, but at least the command will still run...

Recover a deleted file

grep searches through a file and prints out all the lines that match some pattern. Here, the pattern is some string that is known to be in the deleted file. The more specific this string can be, the better. The file being searched by grep (/dev/sda1) is the partition of the hard drive the deleted file used to reside in. The ?-a? flag tells grep to treat the hard drive partition, which is actually a binary file, as text. Since recovering the entire file would be nice instead of just the lines that are already known, context control is used. The flags ?-B 25 -A 100? tell grep to print out 25 lines before a match and 100 lines after a match. Be conservative with estimates on these numbers to ensure the entire file is included (when in doubt, guess bigger numbers). Excess data is easy to trim out of results, but if you find yourself with a truncated or incomplete file, you need to do this all over again. Finally, the ?> results.txt? instructs the computer to store the output of grep in a file called results.txt. Source: http://spin.atomicobject.com/2010/08/18/undelete?utm_source=y-combinator&utm_medium=social-media&utm_campaign=technical

tar.gz with gpg-encryption on the fly

Create a encrypted tar.gz file from a directory on the fly. The encryption is done by GPG with a public key. The resulting filename is tagged with the date of creation. Very usefull for encrypted snapshots of folders.

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Create a new file

Alert on Mac when server is up

When run on a mac, this command will bring up a dialog box in the Terminal when server HOSTNAME first responds to a ping.

Migrate existing Ext3 filesystems to Ext4

Before doing this, back-up all data on any ext3 partitions that are to be converted to ext4. After running previous command you MUST run fsck, is needed to return the filesystem to a consistent state. $ fsck -pDf /dev/yourpartition Edit /etc/fstab and change the 'type' from ext3 to ext4 for any partitions that are converted to ext4.

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