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Show the UUID of a filesystem or partition

Shows the UUID of a filesystem or partition that can be used in kernel root options and in fstab. Run it without the -u option to generate more information. eg: ~/ sudo vol_id /dev/sda2 ID_FS_USAGE=other ID_FS_TYPE=swap ID_FS_VERSION=2 ID_FS_UUID=27fca13d-97b7-4d28-882c-6d03353f0a82 ID_FS_UUID_ENC=27fca13d-97b7-4d28-882c-6d03353f0a82 ID_FS_LABEL= ID_FS_LABEL_ENC= Show Sample Output
This is sample output - yours may be different.
```
c0cddfdb-8a0b-4b45-afb1-b904825bf31d
```
3

sudo vol_id -u /dev/sda1

agentk · 2009-04-30 01:40:58 5
Change wallpaper for xfce4 >= 4.6.0

Simply changes the wallpaper of xfce4 from the command line. Not for multiple displays.
This is sample output - yours may be different.
3

xfconf-query -c xfce4-desktop -p /backdrop/screen0/monitor0/image-path -s <image-file>

TheMightyBuzzard · 2009-04-30 01:40:52 11
send Everyone on your machine some love

This works just like write or wall ... cept one thing the sender is anonymous ... if you really want to drive everyone insane replace echo \"The Matrix has you...\" with cat /dev/urandom nice one to do on April fool's day Show Sample Output
This is sample output - yours may be different.
```
The Matrix has you... (on all writable ttys)
```
-12

w | egrep -v '(load|FROM)' | awk '{print $2}' | sed 's/^/tty/' | awk '{print "echo \"The Matrix has you...\" >> /dev/" $1}' | bash

copremesis · 2009-04-29 22:04:56 10
journaling directories

use today's time stamp to make a unique directory for today or an hour ago ... Show Sample Output
This is sample output - yours may be different.
```
Wed_Apr_29_15_53_58_CDT_2009
```
-4

mkdir `date | sed 's/[: ]/_/g'`

copremesis · 2009-04-29 21:28:45 36
Avoiding history file to be overwritten

If histappend options is set in bash, the file .bash_history will not be overwrite and history list is append to it.
This is sample output - yours may be different.
4

shopt -s histappend

servermanaged · 2009-04-29 19:49:53 4
Prevent non-root users from logging in

Also with optional message: echo "no login for you" > /etc/nologin (This doesn't affect your current X session - you're already logged in!)
This is sample output - yours may be different.
2

touch /etc/nologin

udim · 2009-04-29 19:43:14 4
Nice info browser

pinfo package provide a nice info alternative based on ncurses.
This is sample output - yours may be different.
9

pinfo

servermanaged · 2009-04-29 19:08:37 10
Apache memory usage
This is sample output - yours may be different.
4

ps auxf | grep httpd | grep -v grep | grep -v defunct | awk '{sum=sum+$6}; END {print sum/1024}'

empulse · 2009-04-29 17:43:52 32
Display time of accounts connection on a system

Works on CentOS ad OpenBSD too, display time of accounts connection on a system, -p option print individual user's statistics. Show Sample Output
This is sample output - yours may be different.
```
# ac -p
        nastic                               1.17
        root                                22.67
        total                               23.83
```
2

ac -p

servermanaged · 2009-04-29 16:24:07 228
One liner gdb attach to Acrobat
This is sample output - yours may be different.
0

(acroread &);sleep 2;gdb /opt/Adobe/Reader8/Reader/intellinux/bin/acroread `pidof ld-linux.so.2`

rhythmx · 2009-04-29 16:23:48 11
Get file access control list
This is sample output - yours may be different.
3

getfacl /mydir

servermanaged · 2009-04-29 11:57:14 7
Convert ip address in hexadecimal

Show Sample Output
This is sample output - yours may be different.
```
#  gethostip 208.69.34.230 -x
D04522E6
```
0

gethostip 208.69.34.230 -x

servermanaged · 2009-04-29 11:46:30 3
Change Gnome wallpaper

You can use this in a script which rotates wallpapers from a directory at each login.
This is sample output - yours may be different.
2

gconftool-2 -t string -s /desktop/gnome/background/picture_filename <path_to_image>

o6291408 · 2009-04-29 11:19:29 9
Split lossless audio (ape, flac, wav, wv) by cue file

Do you have an entire album in a unique file and want to split it in individual tracks? If you also have the cue file you can do it! Packages for Debian-based systems users: * cuetools shntool * FLAC (.flac): flac * WavPack (.wv): wavpack * Monkey's Audio (.ape): libmac2 monkeys-audio (deb http://www.debian-multimedia.org sid main) NOTE: "sid" packages are unstable, but I didn't have problems with them. If you prefer, use the "stable" version repository. To transfer the tags, you can use this (works with .flac, .ogg and .mp3): cuetag sample.cue split-track*.flac Show Sample Output
This is sample output - yours may be different.
```
cuebreakpoints sample.cue | shnsplit -o flac sample.ape
Splitting [sample.ape] (76:02.37) --> [split-track01.flac] (7:37.17) : 100% OK
Splitting [sample.ape] (76:02.37) --> [split-track02.flac] (4:33.50) : 100% OK
Splitting [sample.ape] (76:02.37) --> [split-track03.flac] (4:18.18) : 100% OK
Splitting [sample.ape] (76:02.37) --> [split-track04.flac] (4:31.17) : 100% OK
Splitting [sample.ape] (76:02.37) --> [split-track05.flac] (3:47.05) : 100% OK
...
```
5

cuebreakpoints <cue file> | shnsplit -o <lossless audio type> <audio file>

o6291408 · 2009-04-29 10:42:57 4
Send pop-up notifications on Gnome

The title is optional. Options: -t: expire time in milliseconds. -u: urgency (low, normal, critical). -i: icon path. On Debian-based systems you may need to install the 'libnotify-bin' package. Useful to advise when a wget download or a simulation ends. Example: wget URL ; notify-send "Done"
This is sample output - yours may be different.
46

notify-send ["<title>"] "<body>"

o6291408 · 2009-04-29 10:05:20 21
Interactively build regular expressions

txt2regex can be interactive or noninteractive and generates regular expressions for a variety of dialects based on user input. In interactive mode, the regex string builds as you select menu options. The sample output here is from noninteractive mode, try running it standalone and see for yourself. It's written in bash and is available as the 'txt2regex' package at least under debian/ubuntu. Show Sample Output
This is sample output - yours may be different.
```
$ txt2regex --make date --prog vi,perl

### date LEVEL 1: mm/dd/yyyy: matches from 00/00/0000 to 99/99/9999

 RegEx vi  : [0-9]\{2\}/[0-9]\{2\}/[0-9]\{4\}
 RegEx perl: [0-9]{2}/[0-9]{2}/[0-9]{4}
```
8

txt2regex

bwoodacre · 2009-04-29 04:00:22 9
Quickly determine lines in terminal

You've opened a terminal window and you've connected off to a remote host that didn't pick up your terminal size, and all your curses and paging apps are screwed up as a result. You need to quickly determine how many lines are in your current terminal view (to feed into "stty rows X"). Show Sample Output
This is sample output - yours may be different.
```
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
```
-2

_llines=100; while [ $_llines -gt 1 ]; do echo $_llines; _llines=$(($_llines-1)); done

romulusnr · 2009-04-29 00:19:45 7
Convert camelCase to underscores (camel_case)

Useful for switching over someone else's coding style who uses camelCase notation to your style using all lowercase with underscores. Show Sample Output
This is sample output - yours may be different.
```
$ cat file.txt
camelCase
$ sed -r 's/([a-z]+)([A-Z][a-z]+)/\1_\l\2/g' file.txt
camel_case
```
11

sed -r 's/([a-z]+)([A-Z][a-z]+)/\1_\l\2/g' file.txt

atoponce · 2009-04-28 22:44:45 15
Clone /

Clone linux installation.
This is sample output - yours may be different.
1

find . -path ./mnt -prune -o -path ./lost+found -prune -o -path ./sys -prune -o -path ./proc -prune -o -print | cpio -pumd /destination && mkdir /destination/mnt/ && mkdir /destination/proc && mkdir /destination/sys

nutria · 2009-04-28 22:14:45 7
Clone current directory into /destination verbosely

Copy every file from current directory to destination preserving modification time.
This is sample output - yours may be different.
3

find . | cpio -pumdv /destination

nutria · 2009-04-28 22:08:30 8
Set your profile so that you resume or start a screen session on login

From screen's manpage: "Attach here and now. In detail this means: If a session is running, then reattach. If necessary detach and logout remotely first. If it was not running create it and notify the user. This is the author's favorite." Toss this in your ~/.bash_profile so that you never have that "oh crap" moment where you wanted to run something in screen and didn't.
This is sample output - yours may be different.
11

echo "screen -DR" >> ~/.bash_profile

sud0er · 2009-04-28 20:45:37 5
Securely destroy data (including whole hard disks)

GNU shred is provided by the coreutils package on most Linux distribution (meaning, you probably have it installed already), and is capable of wiping a device to DoD standards. You can give shred any file to destroy, be it your shell history or a block device file (/dev/hdX, for IDE hard drive X, for example). Shred will overwrite the target 25 times by default, but 3 is enough to prevent most recovery, and 7 passes is enough for the US Department of Defense. Use the -n flag to specify the number of passes, and man shred for even more secure erasing fun. Note that shredding your shell history may not be terribly effective on devices with journaling filesystems, RAID copies or snapshot copies, but if you're wiping a single disk, none of that is a concern. Also, it takes quite a while :)
This is sample output - yours may be different.
5

shred targetfile

sud0er · 2009-04-28 19:57:43 9
Enable Hibernate in OS X
This is sample output - yours may be different.
-3

sudo pmset -a hibernatemode 1

therod · 2009-04-28 19:53:57 5
Install an mpkg from the command line on OSX

Installing most OSX apps is just a matter of dropping it in /Applications, either GUI-wise or with cp -r. However, many packages are distributed in "mpkg" format, and those have to be installed with an installer. If you don't want to go to the trouble of firing up VNC to install an mpkg, you can use the "installer" command. This will install an application from a .mpkg it to /Applications system-wide. To install a program for just one user, replace "-target /" with "-target username".
This is sample output - yours may be different.
4

sudo installer -pkg /Volumes/someapp/someapp.mpkg -target /

sud0er · 2009-04-28 19:43:56 53
Mount a disk image (dmg) file in Mac OSX

To unmount, replace "attach" with "eject"
This is sample output - yours may be different.
5

hdiutil attach somefile.dmg

sud0er · 2009-04-28 19:41:42 5
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Simple top directory usage with du flips for either Linux or base Solaris

No need to type out the full OR clause if you know which OS you're on, but this is easy cut-n-paste or alias to get top ten directories by singleton. To avoid the error output from du -xSk you could always 2>/dev/null but you might miss relevant STDERR.

Resize A Mounted EXT3 File System

Live extension of an ext3 file system on logical volume $v by 200GB without the need to unmount/remount. Requires that you have 1) a version of resize2fs that contains code merged from ext2online, and 2) kernel support for online resizing. (e.g. RHEL 5)

Using column to format a directory listing

This allows you to find a string on a set of files recursivly

The -r is for recursive, -F for fixed strings, --include='*.txt' identifies you want all txt files to be search any wildcard will apply, then the string you are looking for and the final * to ensure you go through all files and folders within the folder you execute it.

Watch the progress of 'dd'

dcfldd is a forensic version of dd that shows a process indicator by default.

Encrypted chat with netcat and openssl (one-liner)

client$ while true; do read -n30 ui; echo $ui |openssl enc -aes-256-ctr -a -k PaSSw ; done | nc localhost 8877 | while read so; do decoded_so=`echo "$so"| openssl enc -d -a -aes-256-ctr -k PaSSw`; echo -e "Incoming: $decoded_so"; done This will establish a simple encrypted chat with AES-256-CTR using netcat and openssl only. More info here https://nixaid.com/encrypted-chat-with-netcat/

Remote screenshot

Admittedly, I'd never have thought of this without the earlier examples, but here's one that you can execute from your workstation to just display the image from another, without separately doing a file transfer, etc. By the way, I hear a loud beep coming from the other room, so I guess it's not too stealthy :-D

find all active IP addresses in a network

You send a unicast ICMP packet to each host. Many firewalls will drop that ICMP. However, in order to send the ICMP, you'll have first done an ARP request and the remote machine is unlikely to ignore that, so the computer will be in your ARP table.

Go up multiple levels of directories quickly and easily.

Change to your taste. Much quicker than having to add 'cd' every time. Add it to your .bashrc or .bash_profile.

Function to output an ASCII character given its decimal equivalent

I've corrected the function. My octal conversion formula was completely wrong. Thanks to pgas at http://mywiki.wooledge.org/BashFAQ/071 for setting me straight. The new function is from pgas and is very fast.

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