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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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Don't like the cut command? Tired of typing awk '{print $xxx}', try this

Double your disk read performance in a single command

(WARN) This will absolutely not work on all systems, unless you're running large, high speed, hardware RAID arrays. For example, systems using Dell PERC 5/i SAS/SATA arrays. If you have a hardware RAID array, try it. It certainly wont hurt. You may be can test the speed disk with some large file in your system, before and after using this: $ time dd if=/tmp/disk.iso of=/dev/null bs=256k To know the value of block device parameter known as readahead. $ blockdev --getra /dev/sdb And set the a value 1024, 2048, 4096, 8192, and maybe 16384... it really depends on the number of hard disks, their speed, your RAID controller, etc. (see sample)

Monitor cpu in realtime.

Get AWS temporary credentials ready to export based on a MFA virtual appliance

You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

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"

view http traffic

list files recursively by size

Install Linux Kernel Headers on Debian-based systems

Install the Linux kernel headers for currently running kernel version on Debian-based systems via apt-get

Calculating series with awk: add numbers from 1 to 100

"seq 100" outputs 1,2,..,100, separated by newlines. awk adds them up and displays the sum. "seq 1 2 11" outputs 1,3,..,11. Variations: 1+3+...+(2n-1) = n^2 $ seq 1 2 19 | awk '{sum+=$1} END {print sum}' # displays 100 1/2 + 1/4 + ... = 1 $ seq 10 | awk '{sum+=1/(2**$1)} END {print sum}' # displays 0.999023

Send a signed and encrypted email from the command line

A very simple command to send a signed and encrypted message from the command line using GPG Keys

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