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By TeK, December 10, 2011 04:01

HeyHo, the disc is full, the disc is full…, but i found a great help:

“KDirStat – Directory statistics.

Shows where all your disk space has gone
and helps you clean it up.”

Installation in Debian and Ubuntu:

$  apt-get install k4dirstat

I think the screenshot says it all:

Every cube in the tree-map illustration represents a file or a directory. By their size its instantly visible where all the space is used up. You can click the big blocks to get a direct link to the file in the tree.

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By TeK, January 12, 2011 01:23

A quick tip, how to map web-apps on random ports to the main apache webserver. This way you can run these services on subdomains or sub-directories and support SSL encrypted  https connection, even if it is not directly supported.

Take care to not open a proxy for everybody or it can be abused by spammers. “ProxyPass” combined with “ProxyRequests Off” is save.

If the original port is not used anymore, it can be closed in the firewall. Only for the icecast stream it is s useful to keep :8000 open. By mapping to an internal IP a address of a virtual machine, you can also forward to vservers.

The admin webinterface on /admin/ can be redirected by mod_rewrite to a secure SSL connection.

Example: Icecast ProxyPass to map webinterface on port 8000 to apache subdomoain (port 80)

<VirtualHost *:80>
   ... # your vhost here: ServerName, Logs, etc
   ...
   # Proxy ACL
   ProxyRequests Off
   <Proxy>
      Order allow,deny
      Allow from all
   </Proxy>
   # Proxy directives
   ProxyPass / http://192.168.1.7:8000/
   ProxyPassReverse / http://192.168.1.7:8000/
   ProxyPreserveHost on

   # redirect /admin to https:
   RewriteEngine On
   RewriteRule /admin.*  https://tv.example.com:443/admin/ [R]
</VirtualHost>

Example: Icecast ProxyPass to map admin webinterface on port 8000 to apache subdomoain (port 443)

<VirtualHost *:443>
   ... # your vhost here: ServerName, Logs, etc
   ...
   SSLEngine On

   # Proxy ACL
   ProxyRequests Off
   <Proxy>
      Order allow,deny
      Allow from all
   </Proxy>
   # Proxy directives
   ProxyPass / http://192.168.1.7:8000/
   ProxyPassReverse / http://192.168.1.7:8000/
   ProxyPreserveHost on
</VirtualHost>

• Manual: Apache Module mod_proxy

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By TeK, September 25, 2010 18:35

git-workshop

27.09. – 19:00

nerdcafe.10247.net

This lecture is an introduction to git, mainly from client-site,
but some tricks for servers to control access are also introduced (gitosis).
Furthermore, with git-svn you are able to reach a svn-repo via a git repo.

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By TeK, August 15, 2010 04:04

Here’s a comparison of some programs in debian/ubuntu repositories, that help to keep track of your worktimes

KTimetracker
This is in the Debian and Ubuntu repositories. it is programmed for the KDE window environment, but if you have all the KDE libraries already, just run this in a terminal:

wait! update first

it’s best practise to update the repositories before installing something, to get the latest versions:

sudo apt-get update

btw: sudo is only required in ubuntu, in debian type ‘su’ to get root access

sudo apt-get install ktimetracker

++
+ Nice and simple interface.
+ Timers
You can start and stop a timer when you begin and end a working session so you get the exact time.

+ It can even watch your desktops, including the virtual ones, so you can put all your work windows for example on desktop 2 and switching to 1 is enough to do something else and stop the counter. you will wonder about the short times it tracks (without mailchecks, etc.) !

must test the export..

For me this wins, because of the desktop tracking and  (sub) timers!

Installation in Debian / Ubuntu:

sudo apt-get install gnotime

++
Nice interface with description and “diary” textfields. Nice list of projects and timers to count worktime on a daily basis are integrated.

–
Some things in the interface are broken or not understandable: export does not allow to select a file, maybe something must be created first?

Subprojects? must test..

++
Nice webinterface. Besides Todolist, Calendar, CRM and few more modules, a Time-tracking tool is built into this web groupware.

+ So called “Time-accounts” represent the different projects. You can add “time-sheets” to these projects for every session or ideally the hours of every day. There are filters to show only one project or a relevant period or user. You can save these filter options as a favorite view. That’s really cool and flexible! One problem is, that you cannot redefine the default favorite, which it show at first.

+ Tine can store € per hour, “billable” and more billing infos, so you it automatically calculates the full time and price of a project.

–
There is no counter to start and stop the session times. You can only enter the periods, after you finished the day work. Its useful to keep track of the works of a team, but if you want to track the exact times, you need another timer-software and enter the periods from there to tine  :-/

Must test:  Exports!   It ~should~ export .ods, which would be reaaaaally helpful to present the time-sheet to clients directly or put it in a bill! But maybe i have to fill a bug report on that..

Is a good, old PHP web groupware with many, many modules. The project module interface is not easy to understand, but when you get it, you can even use time counters online.

++
Many functions in the projects module,…

–
EGroupware is a huge system, only for timetracking you do not want to install it. There are many options to setup, specially if there is more than one user, it gets really complicated to give correct permissions to everyone.

still the easiest and best solution?

++
+ Table calculation software offers a nice overview with dynamic calculations: Press [F2] in a table cell and you can enter formulars for calculation. This way, you can, for example, enter exact minutes and get hours by [cell] * 60.

+ In OpenOffice Writer you can keep track of times in a simple table inside a odt text-office document. No need to use Calc, the Table calculation

Also the other programs offer ways to enter billing info like € per hour.

–
- Teamwork? Its not easy to work together on stupid office documents. They are practically always locked by other users

.odt file coming soon..

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By ZBog, July 27, 2010 03:24

>> nerdcafe Vetomat 26.7.2010        snufu/fuzzy speach, Zbog report
SHELL BASICS N°3

$ ncal -w

calendar for the current week (it shows the all month)

$ red

open a (strange) text editor in the terminal to go out: q + enter

$ mcedit filename

the famous midnight-command editor (apt-get install mc)

$ mc

clone of an oldschool filemanager

—————————-

$ tput

initialize a terminal

$ reset

query terminfo database
(clear the complete terminal window)

————————–

$ cp "source" "destination"

copy files in directory (is an automatic paste)
=======================================================================================

$ mkdir "name"

make directory “name”

$ ls -l

list all the files and folders in the directory

(-l)     use a long listing format
as the details mode in a location window

$ ls -l "directory-name"

is giving the list of the called directory

$ pwd

Print Working Directory
shows the actual folder content

$ cd ..

go one level up

$ if cd /somewhere; then date;

Only if there is cd folder called like so then show the date

$ echo mario > test/.secret

with the point on the new name it will create a hidden file that is  normally not shown in the interface and  in the command ls

$ ls -a

to recall a hidden file in a list  -a

$ echo /.*

will call also all the hidden files

./

it represents the current directory

../

it represents the parent directory
—————————

$ rm filename

remove file

$ rm /dir/

remove folder

$ rm -r foldername

empty the directory    (delete the files but keep the folder)
—————————-

$ set -x

$ set +x

set
start the behavior session
+
the commmand string is printed on screen before the execution
-
the command string session will not show anymore the command screen

$ echo foo | cat

“pipe echo foo into cat” write the info foo into the file and show the content (cat)
the 2 commands are connected to eatch other and have the same content

Report of Linux-works shell meeting in Vetomat 26.Juli.2010

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By ZBog, July 20, 2010 03:24

>> nerdcafe Vetomat 19.7.2010        snufu/fuzzy speach, Zbog report
SHELL BASICS N°2

$ nmap 192.168.1.0

scan the local subnet to check for available hosts – nmap returns all IPs of running machines in the specified subnet. 192.168.1.0-100 scans IPs 1-100.

(you ll need to apt-get install nmap)

$ uptime

Shows when the pc started; how many users; load average; how many processes are running

$ date

gives you back a date and time

$ ncal

to call the calendar

#

Comment sign
to insert a not exacutable text, frequently used for human comunication instead of the normal typing in the terminal that is readed by default as a command to the computer

*

is a jolly to ask for existing files/Directory for example

$ echo D*

gave:
Desktop Dokumente…
(every file with the D as first letter in the directory where we are located)

?
$ fsdsf?

if you dont remember the last letter of a data
for example fsdfz
the command returns the possible files you are searching
like the asterisc but applies only on the last letter in doubt

$

the dollar $ itself
means a variable

|

the pipeline | between commands is to add multiple commands without writing multiple lines in the terminal

""

are to consider the string as text

$ rm filename

removes files – take care there is no restore the file will be deleted!

$ clear

clean the monitor terminal from previous output lines

$ iwlist wlan0 scan

scan for avalaible networks with network interface wlan0 (the 1. wlan card,usually)

$ ps

programs running by everybody

$ ps aux

more info about the running programs

$ ps aux | less

pipe the processes output into “less” – just for easy reading

>

to redirect and copy the command output to another program

>>

append
attach the output left of >> to the end of the file right off >>
for example

$ echo hiho > foobar
$ cat echo >> foobar

will give as output
foobar

foobar

<

\

(escape) to take out special meaning and read the value as text
example echo “mb\”r*” gives the output
mb”r

true is 0
and frequently in programming it is the opposite: true is 1 !!

$ wc

words count

$ wc -l

wordcount –lines

Report of Linux-works shell meeting in Vetomat 19.Juli.2010

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By ZBog, July 15, 2010 03:20

>> nerdcafe Vetomat 12.7.2010        snufu/fuzzy speach, TKilla report
SHELL BASICS N°1

LinuxWorks workshop about Linux usage of the terminal.

Weekly appointment every Monday in Vetomat at 19:00. Scharnweberstrasse 35, F’hain, Berlin.

the “shell” is the program in the terminal,
–> Application –>Accessories —>Terminal
where you can run all the commands installed on the system
(the shell is called “bash” or “sh” or similar)

>> nerdcafe Vetomat 12.7.2010        snufu/fuzzy speach;  Tk report
SHELL BASICS N°1
———–

all lines in this text starting with $ can be executed in a terminal
watch the output of the commands!!  (almost) every error is written there!

useful commands:
TAB
Its enough to write few letters and use TAB key — multiple times –
to autocomplete the command!!

history:
arrow-up key     - goes back to the previous command
ctrl+r command    - search in command history

the format of the command is always:

commandname parameter1 parameter2 ..
programname -h          or
programname –help  for a long version

gives a short help and possible parameters of the command

$ man programname

manual of the program – RTFM – read this to know what it does

$ apropos burn cd

tells which programs are doind the task

$ ssh user@hostname

login to another computer by console

$ screen -x

join a shared session (on another computer)
must be connected before to (ssh username@hostname)
screen runs multiple terminals (on a remote system) and you can switch between them

screen commands:
ctrl+a    a    - switch to another terminal
ctrl+a  ESC      - scroll with cursor keys

$ ls

list content of current directoy

$ ls -a

list –all: shows also hidden “.” dot-files (config files mostly)

$ less

shows 1 PAGE of output of a command  (contrast to “more” – that shows more )

$ echo hiho > foobar

write hiho into the variable “foobar”

$ cat myman</pre>
<pre>$ tom

outputs the name of the var

$ cd /
"change dir" to root-dir "/"
"/" is the whole system - including all discs/partitions

[c]$ cd    or  cd ~

“change dir” to your home dir “/home/yourusername/”,

$ echo foo > file1

write “foo” into a textfile file1

$ cat file1

print output of file1

$ head

show first lines of file

$ head -n 50

show first 50 lines of file

pipe command “>”

$ iwconfig > file1

write _standard_ output to file1

$ iwconfig > file1

write _serror_ output to file1 – “2″ is the code for error outputs

$ echo ritual > fileX

add lines to file

$ echo ritual2 >> fileX

$ echo ritual3 >> fileX

connect terminal to remote window system

$ ssh username@hostname

connect to another computer and executes commands there

$ ssh -X username@hostname

activate X11 windowing forward on other computer

$ username@hostname: firefox

starts for example firefox on the remote machine and shows it on your screen

$ mv    file1 newfile

move file1 to another

$ less filename

show content of a text file

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By TeK, February 8, 2010 01:50

prototyping breadboard with Arduino backpack

On 28.1.2010 we had our first workshop to introduce the Arduino Microcontroller plattform in Berlin, FHain.

The session took place in Sama32 cafe and there were ~10 nerds, who were interested in micro-controllers and electronics. We presented some hardware and sketches and introduced the connection from arduino inputs to processing sketches.

Thanx to Todbot for the possibility to use his excellent slides!

Who is interested to join the next workshop?

Workshop Info

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By TeK, July 12, 2008 17:10

Wiimote Control Frontend

This is a frontend to simplify the connection and configuration of a Wiimote and its bluetooth connection.

It is based on Cwii Library and can map axis and buttons of the wiimote to keyboard, mouse and joystick events

It has got different preconfigured modes for web-browsing, various games, TV remote control and presentations.

The config files define events like keyboard presses and map them to wiimote events, like button presses and controller values.

debian package coming soon..

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By TeK, June 8, 2008 05:23

Mirror Bots .: moving visuals projections – standalone & Linux GUI controller

This is a robotic system to move VJmix projections all over the walls.

Video: MirrotBot in Action Köpi, Berlin 11.2008

Beamer projection reflection on mirror

Mirrors are mounted on servo motors to rotate them in front of dia projectors or beamers. This way, the projections are moved across the walls and the ceiling of the room.

A microcontroller system, connected to a netbook, is used to control the mirror-servo-unit movements.

“Hotspots” are defined to project on the best spots on the walls of the location and create an impressive light show of moving rays and projections on all walls and screens.

1.prototype live action with diaprojector & beamer

This system can be installed in rooms of any size.

It is required to use projection glass or there are double projections and very unsharpened results. The beamers must be powerful to show bright images also on the must distant walls. In big rooms, the projections are really big, so the 2 video mixes can work together as moving textures or moving characters.

The proof-of-concept system was first used by Headsquatter Live Visuals in Berlin @MIKZ – Suchtfaktor – 27.09.2008 with great success and continuously enhanced and tested live.

Hardware

We use a common, programmable input/output hardware controller to trigger motors: Arduino Dicemilia.

1.prototype live action -- only left dia is mirrored

Two Mirrors are mounted on  servos to move them in front of two video beamers. This first version can move 2 projections with 2 mirrors on one horizontal axis between 40° and 130° – ca.  It  creates distorted projections depending on the current angle, but works very well with various kinds of video mixes. High contrast images and vectorial animations work specially good. By positioning two projections besides each other there appear many interesting possibilities.

Combined with fog machines the rays become visible and the moving beams look like a laser show with real videos.

The servo-mirror movements are synchronized to the beat of the music and many programs can be selected, to move the projections in various patterns.

VJ Live Mix Box: Wiimote - VJ mixer - Arduino Servo Control - Mirror (+ eeePC ) - Linux Netbook

Software

This MirrorBot is controlled by a linux netbook over serial console via USB cable. The prototype is remote-controlled  by a simple software command line. Various keyboard key presses change program, speed, play/pause mode of the attached servo control box. This works quite good during live visuals mixes, with a mini terminal window in front of a TVtime preview screen of the video mixer.

Pictures by Rue23 in MIKZ 27.09.2008 – Suchtfaktor Party ::

more Pix @