Friday, April 5, 2013

Remember to remove the GPS data from your images

Many smartphones and cameras today also contain a GPS module, which enables the devices to store the GPS position of the site/location where the picture was taken, inside the picture itself, inside the EXIF data.
This information is then public to everyone when you upload the pictures to the evil www....
Therefore remember to remove the GPS data before uploading image file.
A tool for this is here: www.digitalconfidence.com/downloads.html

Friday, December 28, 2012

NSLU2: How to change the hard drive

To migrate the hard drive of your NSLU2 to a new one perform the two follwing steps:
Step 1: Copy the content of the hard disk to a new hard disk.
Step 2: Expand the partition to fill all the available space on the the new hard disk.


Step 1: Copy the content of the hard disk to a new hard disk.

 (in part from http://linuxcommando.blogspot.com/2008/06/show-progress-during-dd-copy.html )

Copy the content of disk 1 (mounted on /dev/sdb) to disk 2 (mounted on /dev/sdc ) (if adjust sdb, sdc, sdd, etc acording to your own configuration, you might use gparted to check the names). Block size below is 1M (1 mb):
$ dd if=/dev/sdb of=/dev/sdc bs=1M  

Follow the progress forof the process by executing the following command in an other command window:
$ kill -USR1  8789
Find the process ID by running the command (and replace 8789 acordingly):
$ pgrep -l '^dd$'
8789 dd
$

Step 2: Expand the partition to fill all the available space on the the new hard disk.

Install gparted, launch it. Expand the large partition on the disk to fill to take advantage of all the available space.Move the other partitions acordingly. Do not delete og shrink any othe the other partitions.

Tuesday, December 25, 2012

Suspend Ubuntu 12.04 LTS on Asus U32U

Do the following
(all instructions from: http://thecodecentral.com/2011/01/18/fix-ubuntu-10-10-suspendhibernate-not-working-bug):

Step 1

Create a script under /etc/pm/sleep.d/. It can be any name, but to ensure the load order, use the prefix 20_.
gksudo gedit /etc/pm/sleep.d/20_custom-ehci_hcd 

#or the way you would normally do when creating a file as superuser  
 

Step 2

Note that if you use the code from "Step 2 Old" below, please skip this step. This script is contributed by commenter Danne.
Insert the following code into the file you have just created:

#!/bin/sh
#inspired by http://art.ubuntuforums.org/showpost.php?p=9744970&postcount=19
#...and http://thecodecentral.com/2011/01/18/fix-ubuntu-10-10-suspendhibernate-not-working-bug    
# tidied by tqzzaa :)

VERSION=1.1
DEV_LIST=/tmp/usb-dev-list
DRIVERS_DIR=/sys/bus/pci/drivers
DRIVERS="ehci xhci" # ehci_hcd, xhci_hcd
HEX="[[:xdigit:]]"
MAX_BIND_ATTEMPTS=2
BIND_WAIT=0.1

unbindDev() {
  echo -n > $DEV_LIST 2>/dev/null
  for driver in $DRIVERS; do
    DDIR=$DRIVERS_DIR/${driver}_hcd
    for dev in `ls $DDIR 2>/dev/null | egrep "^$HEX+:$HEX+:$HEX"`; do
      echo -n "$dev" > $DDIR/unbind
      echo "$driver $dev" >> $DEV_LIST
    done
  done
}

bindDev() {
  if [ -s $DEV_LIST ]; then
    while read driver dev; do
      DDIR=$DRIVERS_DIR/${driver}_hcd
      while [ $((MAX_BIND_ATTEMPTS)) -gt 0 ]; do
          echo -n "$dev" > $DDIR/bind
          if [ ! -L "$DDIR/$dev" ]; then
            sleep $BIND_WAIT
          else
            break
          fi
          MAX_BIND_ATTEMPTS=$((MAX_BIND_ATTEMPTS-1))
      done  
    done < $DEV_LIST
  fi
  rm $DEV_LIST 2>/dev/null
}

case "$1" in
  hibernate|suspend) unbindDev;;
  resume|thaw)       bindDev;;
esac

Step 3

Add executable permission:
sudo chmod 755 /etc/pm/sleep.d/20_custom-ehci_hcd

Result

Your suspend should be now working as expected. Suggestions on improving this script are welcome.

Thursday, April 7, 2011

Linux on Windows: CYGWIN

In order to setup a working linux environment on Windows try Cygwin. Cygwin is a implementation of a range of linux functions/functionality for Windows.

  1. Go to www.cygwin.com and download the setup file.
  2. Run the file by double click and choose "install from internet".
  3. When prompted I prefer to install Cygwin to "Program Files", which although warned about does not seem to give problems.
  4. When prompted for choosing packages choose:
    • Editors
      • emacs
      • mc
    • Net
      • openssh
      • rsync
  5. Finish the installation. 
  6. Run (double click) the shortcut on the desktop. It will create your home folder in the appropriate location (in this case (english WinXP) "C:\Program Files\cygwin\home\you").
  7. In the Cygwin window run "ssh" which will create the ".ssh" folder in your home folder.

Friday, February 11, 2011

Cygwin: Setting up a trusted ssh-relationship

If you are frequently connecting via ssh to the same server or if you are using rsync to backup your files as will be described in a later guide, you might want to set up a trusted relationship between your local computer and the remote server.

Start by generating a private/public key set.
Run the following command:
$ ssh-keygen -t rsa

Now go to your local .ssh folder.
Then download the "authorized_keys" file from the server
scp user@server.com:/home/user/.ssh/authorized_keys .
then make a backup copy of the file:
$ cp authorized_keys authorized_keys.backup
now merge public key id_rsa.pub into the authorized_keys file
$ cat authorized_keys id_rsa.pub
and upload the authorized_keys file to the server
$ scp authorized_keys user@server.com:/home/user/.ssh

Now try and connect via ssh:
$ ssh user@server.com
It should now not prompt for password.

NSLU2: When the power supply (PSU) dies ...

Problem: My NSLU2 has stopped working. Problem pinned down to being the power supply. The following description matches very well my experience, although my power supply worked 24/7 for 3 years (the first two supplying a 2.5' disc.:

"It showed an interesting mode of failure.... after being used for about 1 year 24/7, the LED still illuminated and the unloaded votlage was 5.0V (good) but when a Slug was switched on, the voltage dropped to about 3V and the Slug could not boot. The Slug's Power LED showed faint 'pulsing' in time with USB Memory stick access attempts (difficult to see with your finger over the Power button though). The power supply was binned. "

Diagnose:
"It has been noticed that the supplied Linksys PSU appears to fail after about a year if supplying two USB powered 2.5" laptop drives from the NSLU2.Symptoms include, but not limited to hard drives not being mounted properly at boot time, although the slug will boot with no disks attached for a while until the supply dies completely." - nslu2-linux.org

My solution:
I bought a "AC Power Adapter/Charger for PSP 1000/2000/3000" from dealextreme.com. Then I exchanged the plug that the Power Adapter/Charger came with the plug from the original NSLU2 PSU. When doing this, BE CAREFUL and use a voltmeter/multimeter to make sure + and - are connected correctly. Double double check, because you might end up destroying your NSLU2 if applying a wrong voltage.

I did all this, and my slug is again running like a charm.

Monday, February 7, 2011

Cygwin: Making a ssh connection with tunnels to your server

To make a ssh connection to a linux server, do the following:
Start by loading Cygwin: Start a cmd prompt and load Cygwin:
C:\folder>loadcygwin (the script is described here).

the run the ssh connect command:
C:\folder>ssh user@server.com

This will prompt for your password before allowing the connecntion. Voilá!

If you want to take advantage of one of the strengths of ssh, namely the tunnels run the command as:
C:\folder>ssh user@server.com -L 123:remotehost:456

which will open port 123 locally (on your computer/localhost) which is tunneled to port 456 on the server remotehost.

You can with benefit put this command into a batch (.cmd) file, such as the following ssh_server_com.cmd.

ssh_server_com.cmd:

@echo off
echo Connecting ...
call loadcygwin.cmd

ssh user@server.com -L1125:localhost:25 
-L22993:imap.gmail.com:993
-L993:imap.gmail.com:993 
-L22995:pop.gmail.com:995 
-L22587:smtp.gmail.com:587
-L8888:localhost:8888 
-L8080:localhost:8080

Cygwin: Setting up the environment and locale

When using Cygwin to connect to linux servers, and when using Cygwin in a windows environment in general, it is important to get the locale right.

I am using Cywin through cmd-sessions, and I load Cygwin manually for each cmd-prompt session, as I do not want to override the Windows/Dos commands by default.
Thus I run the file loadcygwin.cmd each time I want to switch to/load Cygwin.
The content of loadcygwin.cmd is listed below:

loadcygwin.cmd:

@echo off
call setcygwinenvironment.cmd
:: WinXp
set path=c:\Program Files\CygWin\bin;%path%
::Win7
::set path=C:\Program Files (x86)\cygwin\bin;%path%
echo Cygwin now loaded.

In this file I am calling the script setcygwinenvironment.cmd which sets the locale. (As you can see I am living in Denmark, which my locale settings reflect)

setcygwinenvironment.cmd:

echo Setting up CYGWIN environment...

:: Set cygwin locale to the same as windows locale.
set LANG=da_DK-UTF-8
set LC_CTYPE=da_DK.UTF-8
set LC_NUMERIC=da_DK.UTF-8
set LC_TIME=da_DK.UTF-8
set LC_COLLATE=da_DK.UTF-8
set LC_MONETARY=da_DK.UTF-8
set LC_MESSAGES=da_DK.UTF-8
set LC_ALL=da_DK
set CYGWIN=acl nodosfilewarning
echo done.

Monday, November 29, 2010

A sister site : www.tvass.eu

I/we have just launched a sister site to this blog, namely the www.tvass.eu site, which will be featuring the same articles and snippets as this blog, albeit maybe in a more structured form. Please visit the site and support it. And... share with friends.

Saturday, November 20, 2010

Mediaportal: How to install mediaportal

If you (like i did) have an old PC which you do not use and at the same time need a mediacentre, why dont you give mediaportal a shot? It is open source, free and for windows.
Here goes:
  1. Download the latest version here .
  2. Launch the installer file.
  3. Choose your country.
  4. Choose "Start installation now".
  5. If there is ANY chance that you will be using mediaportal to either watch or record TV, answer yes to the question of whether you are going to use mediaportal to watch TV.
  6. Unless you know very well what you are doing (and if you are, you not reading this), choose install all in one click.
  7. If you are installing under Windows Vista or Windows 7, you will be asked which network the TV-server may communicate on. I have chosen only private networks and would recommend this setting.
  8. The setup is now done installing and you will be shown the MediaPortal Manual Documentation .
  9. You are now done installing MediaPortal - Have fun! (I will continue posting articles on how to setup things and features on this blog...)