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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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FAST Search and Replace for Strings in all Files in Directory

I needed a way to search all files in a web directory that contained a certain string, and replace that string with another string. In the example, I am searching for "askapache" and replacing that string with "htaccess". I wanted this to happen as a cron job, and it was important that this happened as fast as possible while at the same time not hogging the CPU since the machine is a server. So this script uses the nice command to run the sh shell with the command, which makes the whole thing run with priority 19, meaning it won't hog CPU processing. And the -P5 option to the xargs command means it will run 5 separate grep and sed processes simultaneously, so this is much much faster than running a single grep or sed. You may want to do -P0 which is unlimited if you aren't worried about too many processes or if you don't have to deal with process killers in the bg. Also, the -m1 command to grep means stop grepping this file for matches after the first match, which also saves time.

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

Find where a kind of file is stored

In this case searches for where .desktop files are stored. The resulted is a sorted list of the top directories containing such files.

Quickly generate an MD5 hash for a text string using OpenSSL

Here Strings / A variant of here documents, the format is:

Erase DVD RW

Find the package that installed a command

check the status of 'dd' in progress (OS X)

"killall -USR1 dd" does not work in OS X for me. However, sending INFO instead of USR1 works.

positions the mysql slave at a specific master position

say you want to reinitialize the slave database without resetting the master positions. You stop the slave, dump the master database with --master-data=2 then execute the command on the slave and wait for it to stop at the exact position of the dump. reinit the slave db and start the slave. enjoy.

Creates a 'path' command that always prints the full path to any file

The command creates an alias called 'path', so it's useful to add it to your .profile or .bash_profile. The path command then prints the full path of any file, directory, or list of files given. Soft links will be resolved to their true location. This is especially useful if you use scp often to copy files across systems. Now rather then using pwd to get a directory, and then doing a separate cut and paste to get a file's name, you can just type 'path file' and get the full path in one operation.

Host cpu performance

Measure the cpu performance: In-case if the cpu is thermal throttling then you can find it using this command. Check the first line of the output. Example: Doing md5 for 3s on 16 size blocks: 11406892 md5's in 2.98s ? #(When cpu is not throttling) Doing md5 for 3s on 16 size blocks: 110692 md5's in 2.98s ?? #(When cpu is thermal throttling) Practical use case: Once we had cooling outage in data center which caused thermal throttling in some of the worker nodes. We used this tool to prove that some servers are not performing well because of the cpu thermal throttling.

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