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Replace strings in files

Replace the word 'war' to word 'peace' in every file in the current directory.
This is sample output - yours may be different.
0

sed -i -e 's/war/peace/g' *

tiagofischer · 2010-01-02 13:16:35 3
Shorten url using bit.ly API

It uses curl --url-encode to encode long URLs *properly* and parses XML with xmlstarlet. If ~/.bitlyrc were to contain login:apikey then a script could read the apiKey and login from ~/.bitlyrc like so: login=$(sed 's/:.*//' < $HOME/.bitlyrc) apikey=$(sed 's/[^:]*://' < $HOME/.bitlyrc) curl -s --data-urlencode 'longUrl='$1 --data-urlencode 'login='$login --data-urlencode 'apiKey='$apikey 'http://api.bit.ly/shorten?version=2.0.1&format=xml' | xmlstarlet sel -T -t -m "//shortUrl" -v "." | line Show Sample Output
This is sample output - yours may be different.
```
[16:58][~]$ bitly http://google.com
http://bit.ly/4sloPA
```
0

curl -s --data-urlencode 'longUrl='$1 --data-urlencode 'login='$login --data-urlencode 'apiKey='$apikey 'http://api.bit.ly/shorten?version=2.0.1&format=xml' | xmlstarlet sel -T -t -m "//shortUrl" -v "." | line

jnash · 2010-01-02 11:32:42 3
cd up a number of levels

Instead of typing "cd ../../.." you can type ".. 3". For extremely lazy typists, you can add this alias: alias ...=".. 2" ....=".. 3" - so now you can write just .... !!! NB the .. function needs to be "source"d or included in your startup scripts, perhaps .bashrc.
This is sample output - yours may be different.
4

function ..(){ for ((j=${1:-1},i=0;i<j;i++));do builtin cd ..;done;}

bhepple · 2010-01-02 08:36:12 12
convert wav into mp3 using lame
This is sample output - yours may be different.
1

lame -V2 rec01.wav rec01.mp3

eastwind · 2010-01-01 06:09:46 4
Chage default shell for all users [FreeBSD]

This command will set bash as the default shell for all users in a FreeBSD system.
This is sample output - yours may be different.
6

cd /usr/home && for i in *;do chsh -s bash $i;done

casidiablo · 2009-12-31 18:48:53 6
pipe output to notify-send

Route output to notify-send to show nice messages on the desktop, e.g. title and interpreter of the current radio stream
This is sample output - yours may be different.
2

echo 'Desktop SPAM!!!' | while read SPAM_OUT; do notify-send "$SPAM_OUT"; done

michelsberg · 2009-12-31 15:38:35 3
Display _something_ when an X app fails

When you run an X program from a terminal you can see any errors. But when it's run from another X program (eg from a menu item, from your fluxbox 'keys' file etc) it might just die and you see nothing (except perhaps in .xsession-errors). Instead, launch it via this command and you'll see the termination status, stderr and stdout. eg: "xlaunch firefox" or "xlaunch 'echo stdout; echo stderr >&2; false'": 'echo stdout; echo stderr >&2; false' failed with error 1 STDERR: stderr STDOUT: stdout
This is sample output - yours may be different.
1

xlaunch(){ T=/tmp/$$;sh -c "$@" >$T.1 2>$T.2;S=$?;[ $S -ne 0 ]&&{ echo -e "'$@' failed with error $S\nSTDERR:\n$(cat $T.2)\nSTDOUT:\n$(cat $T.1)\n"|xmessage -file -;};rm -f $T.1 $T.2;}

bhepple · 2009-12-31 06:59:56 3
Setup a persistant SSH tunnel w/ pre-shared key authentication

This creates a persistent ssh -i /path/to/key -ND local-IP:PORT User@Server connection. You may have to install autossh. -f puts in daemon mode. if you are having trouble, try it without -f.
This is sample output - yours may be different.
4

autossh -f -i /path/to/key -ND local-IP:PORT User@Server

fotoflo · 2009-12-31 06:10:03 5
external projector for presentations

i spent way too many hours trying to fiddle with /etc/X11/xorg.conf trying to hook up various external projectors. too bad i didn't know this would solve all my problems.
This is sample output - yours may be different.
8

xrandr --auto

kanzure · 2009-12-30 18:52:02 9
mount an iso

mounts an ISO file to a directory on the target file system
This is sample output - yours may be different.
6

mount -o loop -t iso9660 my.iso /mnt/something

kanzure · 2009-12-30 18:49:30 4
climagic's New Year's Countdown clock

This is the 140 character long new year's countdown timer that was posted to the climagic account on twitter and identi.ca. There are saner ways of doing this of course, but probably none of those would fit. Uses the figlet command, but of course you can replace figlet with just echo if you want. Show Sample Output
This is sample output - yours may be different.
```
 _ ____  _____ ___   ___   __
/ |___ \|___ // _ \ ( _ ) / /_
| | __) | |_ \ (_) |/ _ \| '_ \
| |/ __/ ___) \__, | (_) | (_) |
|_|_____|____/  /_/ \___/ \___/
```
6

while V=$((`date +%s -d"2010-01-01"`-`date +%s`));do if [ $V == 0 ];then figlet 'Happy New Year!';break;else figlet $V;sleep 1;clear;fi;done

deltaray · 2009-12-30 18:42:38 11
Increase mplayer maximum volume

use '0' and '9' to increase/decrease volume. this is useful on laptops with low speaker volume.
This is sample output - yours may be different.
7

mplayer dvd:// -softvol -softvol-max 500

kanzure · 2009-12-30 18:19:44 9
Find and print pattern location from all files on command line from directory and its sub directories.

The command will help to print the location of the pattern. Above command will print all the files which contain variable "$foo" along with line containing that pattern. Specify pattern after "grep"
This is sample output - yours may be different.
-1

find . -exec grep $foo {} \; -print

linuxgeek · 2009-12-30 17:41:44 4
monitor network traffic and throughput in real time

see http://iptraf.seul.org/ for all kinds of documentation and screenshots
This is sample output - yours may be different.
4

iptraf

linuxrawkstar · 2009-12-30 15:41:21 4
Get your public ip

Requires Python; doesn't require a specific server to return your IP.
This is sample output - yours may be different.
-11

python -c "import socket; s=socket.socket(socket.AF_INET, socket.SOCK_DGRAM); s.connect(('google.com', 80)); print s.getsockname()[0]"

whiteinge · 2009-12-29 19:17:03 10
generate random password

eliminates "l" and "o" characters change length by changing 'x' here: cut -c 1-x Show Sample Output
This is sample output - yours may be different.
```
d6pd9625
```
-3

openssl rand -base64 1000 | tr "[:upper:]" "[:lower:]" | tr -cd "[:alnum:]" | tr -d "lo" | cut -c 1-8 | pbcopy

_eirik · 2009-12-29 17:18:25 31
Display the output of a command from the first line until the first instance of a regular expression.

Slightly simpler version of previous sed command that does the same thing. In this case, the output will stop at the command, and the entire command will be terminated as well, instead of proceeding through the whole file.
This is sample output - yours may be different.
1

command | sed '/regex/q'

taliver · 2009-12-29 14:52:41 3
Check if file is greater than 20 bytes, such as an empty gzip archive

If you gzip an empty file it becomes 20 bytes. Some backup checks i do check to see if the file is greater than zero size (-s flag) but this is no good here. Im sure someone has a better check than me for this? No check to see if file exists before checking it's size.
This is sample output - yours may be different.
-2

BACKUP_FILE_SIZE=`eval ls -l ${BACKUP_FILE} | awk {'print $5'}`; if [ $BACKUP_FILE_SIZE -le 20 ]; then echo "its empty"; else echo "its not empty"; fi

Redrocket · 2009-12-29 08:34:37 3
Empty a file
This is sample output - yours may be different.
6

> foobar.txt

unixmonkey7657 · 2009-12-29 08:08:15 4
Empty a file
This is sample output - yours may be different.
-1

truncate foobar.txt

w216 · 2009-12-29 01:52:12 3
find out how much space are occuipied by files smaller than 1024K (sic) - improved

The original didn't use -print0 which fails on weird file names eg with spaces. The original parsed the output of 'ls -l' which is always a bad idea.
This is sample output - yours may be different.
2

find dir -size -1024k -type f -print0 | du --files0-from - -bc

bhepple · 2009-12-29 01:33:55 3
Press Any Key to Continue

how to finish command or script without any output Show Sample Output
This is sample output - yours may be different.
```
root@ubuserver:~# read enterKey

root@ubuserver:~#
```
-4

read enterKey

bbmarek · 2009-12-29 00:18:32 7
reload config

reload a configuration from .bashrc file Show Sample Output
This is sample output - yours may be different.
```
root@ubuserver:~# source .bashrc
root@ubuserver:~#
```
0

source .bashrc

bbmarek · 2009-12-29 00:14:34 17
Get your public ip
This is sample output - yours may be different.
0

curl -s http://icanhazip.com/

w216 · 2009-12-28 23:00:37 3
Read just the IP address of a device
This is sample output - yours may be different.
0

ifconfig -l | xargs -n1 ipconfig getifaddr 2> /dev/null

w216 · 2009-12-28 22:45:45 3
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Repeat a portrait eight times so it can be cut out from a 6"x4" photo and used for visa or passport photos

Yes, You could do it in the GIMP or even use Inkscape to auto-align the clones, but the command line is so much easier. NOTE: The +clone and -clone options are just to shorten the command line instead of typing the same filename eight times. It might also speed up the montage by only processing the image once, but I'm not sure. "+clone" duplicates the previous image, the following two "-clone"s duplicate the first two and then the first four images. NOTE2: The -frame option is just so that I have some lines to cut along. BUG: I haven't bothered to calculate the exact geometry (width and height) of each image since that was not critical for the visa photos I need. If it matters for you, it should be easy enough to set using the -geometry flag near the end of the command. For example, if you have your DPI set to 600, you could use "-geometry 800x1200!" to make each subimage 1⅓ x 2 inches. You may want to use ImageMagick's "-density 600" option to put a flag in the JPEG file cuing the printer that it is a 600 DPI image. BUG2: ImageMagick does not autorotate images based on the EXIF information. Since the portrait photo was taken with the camera sideways, I made the JPEG rotate using jhead like so: jhead -autorot 2007-08-25-3685.jpg

Backticks are evil

This is a simple example of using proper command nesting using $() over ``. There are a number of advantages of $() over backticks. First, they can be easily nested without escapes: $ program1 $(program2 $(program3 $(program4))) versus $ program1 `program2 \`program3 \`program4\`\`` Second, they're easier to read, then trying to decipher the difference between the backtick and the singlequote: `'. The only drawback $() suffers from is lack of total portability. If your script must be portable to the archaic Bourne shell, or old versions of the C-shell or Korn shell, then backticks are appropriate, otherwise, we should all get into the habit of $(). Your future script maintainers will thank you for producing cleaner code.

Extract shortcuts and hostnames from .ssh/config

Spits out table that shows your Host->HostName aliases in ~/.ssh/config

find and delete empty dirs, start in current working dir

Speed up launch of liferea

If you use liferea frequently, you will see obvious speedup after you executed this command.

Paste the contents of OS X clipboard into a new text file

Unix commandline history substitution like ^foo^bar BUT for multiple replacements

#1 You invoked a command chain. #2 You globaly replace the scriptnames and execute them direct #3 The new executed command chain [# ^foo^bar] would only replace the firts match [foo] with [bar].

Find public IP when behind a random router (also see description)

Depends on GET. You can also replace GET with curl, or `wget -qO -` if GET isn't available.

Performance tip: compress /usr/

Periodically run the one-liner above if/when there are significant changes to the files in /usr/ = Before rebooting, add following to /etc/fstab : = $ /squashed/usr/usr.sfs /squashed/usr/ro squashfs loop,ro 0 0 $ usr /usr aufs udba=reval,br:/squashed/usr/rw:/squashed/usr/ro 0 0 No need to delete original /usr/ ! (unless you don't care about recovery). Also AuFS does not work with XFS

Removing images by size

Removes all png files whose geometry is not 280x190 pixels

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