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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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Identify name and resolution of all jpgs in current directory

back ssh from firewalled hosts

host B (you) redirects a modem port (62220) to his local ssh. host A is a remote machine (the ones that issues the ssh cmd). once connected port 5497 is in listening mode on host B. host B just do a ssh 127.0.0.1 -p 5497 -l user and reaches the remote host'ssh. This can be used also for vnc and so on.

Test sendmail

test if sendmail is installed and working.

Printable random characters

Reads psuedorandom bytes from /dev/urandom, filtering out non-printable ones. Other character classes can be used, such as [:alpha:], [:digit:] and [:alnum:]. To get a string of 10 lowercase letters: $ tr -dc '[:lower:]' < /dev/urandom | head -c 10

Detect illegal access to kernel space, potentially useful for Meltdown detection

Based on capsule8 agent examples, not rigorously tested

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"

PRINT LINE the width of screen or specified using any char including Colors, Escapes and metachars

One of the first functions programmers learn is how to print a line. This is my 100% bash builtin function to do it, which makes it as optimal as a function can be. The COLUMNS environment variable is also set by bash (including bash resetting its value when you resize your term) so its very efficient. I like pretty-output in my shells and have experimented with several ways to output a line the width of the screen using a minimal amount of code. This is like version 9,000 lol. This function is what I use, though when using colors or other terminal features I create separate functions that call this one, since this is the lowest level type of function. It might be better named printl(), but since I use it so much it's more optimal to have the name contain less chars (both for my programming and for the internal workings). If you do use terminal escapes this will reset to default. $ tput sgr0 For implementation ideas, check my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Bring the word under the cursor on the :ex line in Vim

Very handy to bring the word currently under the cursor into a :s command in Vim. Example: If the cursor was on the word "eggs": :s/ ==> :s/eggs

Copy a file and force owner/group/mode

This is useful when you want to copy a file and also force a user, a group and a mode for that file. Note: if you want to move that file instead of copying it, you can use $install -o user -g group -m 755 /path/to/file /path/to/dir/ && rm -f /path/to/file which will remove the file only if the install command went fine.

Download all images on a 4chan thread

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