This works for a couple of subdomains/sites only. If you need to have a load of sites or other settings this is not for you. On the other hand this method needs no web server configuration.

1. In your systems hosts file (Windows: In your favourite text editor open %SYSTEMROOT%\system32\drivers\etc\hosts and on Linux it’s /etc/hosts.
2. Find the line defining 127.0.0.1, i.e. your local horst, erm localhost and append sitename1.localhost to the end of the line. do so for every site name you need.
3. Go to your apaches/webservers documents folder holding your drupal installation. Say it’s htdocs/drupal than you need folder sites. There should be at least two folders called all and default. Copy default and name it sitename1.localhost, i.e. excactly the string you added to your hosts file (again you need to replace sitename1 by your site’s name but do include the dot!).
4. In your web browser type sitename1.localhost/drupal to test if drupal shows up at all (meaning your OS resolves your “domain name” correctly) and if it shows your old content (meaning it works).

Now you have two options to actually set up your “new site”: Either edit the settings.php that should be in the new folder to use a diferent data base (that should be well-stocked with drupal data) or just install a fresh drupal site. You achieve the later by doing:

1. Delete settings.php. That should leave you with a file named default.settings.php.
2. Point your browser to sitename1.localhost/drupal/install.php and do everything like you did with the first install but use a diferent database (or the same but different database prefix).
3. Done.

Resources

• settings.php

Furthur reading

• Drupal Coder on multisite in subfolders

As described at it’s straight forward:

sudo /bin/hostname mynewhostname

Supplying the path to the binary is for security reasons, I guess, to make sure we have the right bin (eventhough it could have been replaced there, too…).

But the people at debianadmin.com forgot to mention in order to avoid “hostname: Unknown Host” you have to

sudo edit /etc/hosts

and change it there, too!

Straight from Ubuntuguide.org:

You can also get Mouse over preview to work by installing:

sudo apt-get install mpg321
sudo apt-get install mpg123-esd
sudo apt-get install vorbis-tools
sudo apt-get install esound
sudo apt-get install ubuntu-restricted-extras

with this system Skype still functions.

Also, there is a very interesting article at Linux Owns showing three steps to get all your favourite packages (back) fast. I added a fourth step actually saving your package list for later use. Deriving it straight from there (without testing, since unfortunatelly my last machine has been hardyed just a couple of hours ago):

1. integrate medibuntu sources.list

   sudo wget http://www.medibuntu.org/sources.list.d/gutsy.list -O /etc/apt/sources.list.d/medibuntu.list
   

2. add server key

   wget -q http://packages.medibuntu.org/medibuntu-key.gpg -O- | sudo apt-key add - && sudo apt-get update
   

3. write a text file listing all package names you wish installed separated with spaces — you should be able to instead put every package name in one line with trailing \\ (double back-slash) but as I said: I haven’t tested it, yet! Name it, say, most_important_debs.

4. sudo aptitude --assume-yes install < most_important_debs
   

   You might want to approve the package list before install. In that case omit –assume-yes

Let me know it someone used it (hopefully with success).

Update 2008/05/15: It does help to read and think before you speak (or write for that matter). I got it completely wring. The linked article is about packages from Medibuntu only. OK then, if it’s like this I just alter 1, 2, 4 and 3 -> 1

1. build a list of your (most important, enduser) packages
2. update-manager -d, i.e. dist-upgrade your system
3. employ aptitude to read in your file (to be exact it’s bash that redirect from the file…)

Of course, this method still does not solve the problem of saving your personal settings but still get all the system settings from the new distro release. But this shouldn’t be that hard for release maintainers since they (potentially) know which package version had what config files delivered or generated. From there it should be easy to determine if a system config file has been changed be the user -> show diff. Or do I overlook something once again?

Update 2008/05/15: Even better looks aptitude-run-state-bundle:

DESCRIPTION
aptitude-create-state-bundle produces a compressed archive storing the files that are required to replicate the current
package archive state.  The following files and directories are included in the bundle:
·      $HOME/.aptitude
·      /var/lib/aptitude
·      /var/lib/apt
·      /var/cache/apt/*.bin
·      /etc/apt
·      /var/lib/dpkg/status
The output of this program can be used as an argument to aptitude-run-state-bundle(1).

Update 2008/05/15: A good starting point would be either

dpkg -l | grep ^i | editor

or if you don’t use aptitude this also shows (only currently) installed packages

dpkg -l | grep ^i | editor

One needs to remove non-package-name strings, though. As I haven’t come around to learn sed (line editing) I cannot show how to deploy sed to do it. Anyone?

There is a neat cheat sheet out in PDF format from FOSS covering, among many others, the new Ubuntu Uncomplicated Firewall ufw, special packages, of course apt-family package management, services a.k.a init scripts and daemons, …

It’s released under CC-BY-SA 3.0. By the way, did you know

Type the phrase “REISUB” while
holding down Alt and SysRq (PrintScrn) with
about 1 second between each letter. Your system
will reboot.

You can do Dist-Upgrades not only with the GUI update-manager but also via do-release-update. The tool tells me what awaits me (I have 6000 kB/s):

66 packages are going to be removed. 193 new packages are going to be
installed. 1269 packages are going to be upgraded.

You have to download a total of 1005M. This download will take about
23 minutes with your connection.

Fetching and installing the upgrade can take several hours. Once the
download has finished, the process cannot be cancelled.

So, let’s see.

Btw do-release-update by itself notices if you are connected via ssh and asks if you want to proceed. If you do you’ll get a second sshd on Port 9904. Using screen it shouldn’t be a problem for me but very nice of the tool to ask

After I created a new user testuser

sudo adduser testuser

I couldn log in this new user via

ssh newuser@localhost

SSH told me “Permission denied, please try again.” If I’d only switch users with

su - newuser

login was granted. So I had a look at

sudo vim /etc/ssh/sshd_config

and looked for

AllowUsers

and appended the new user in that line. Now I needed to reload (in case you are logged in via ssh) the server:

sudo /etc/init.d/ssh reload

and access is granted!

Ressources

• None

Allthough I haven’t found some shiny GUI somewhat like Netlimiter there is Wonder shaper (and shaper and trickle and squid for http and …) where a single command line sets your over-all bandwidth for network interface X. And, isn’t that all you really need?:

sudo wondershaper ethX downlink(kbit/s) uplink(kbit/s)

This is, from the perspective of the host doing the shaping. For example to set download to 10000kb (750*8 = 6000 DSL but don’t limit intranet connections on 1Mb Ethernet) but limit upload to, say, 35kB (~280kb) — e.g. if you have a server running on the same connection you do your daily internetting, you do:

sudo wondershaper eth0 10000 280

Ressources

• Ubuntuusers.de Forum (German)
• Traffic Shaping (German)
• Squid Delay Pools (German)
• Bandwidth Limiting HOWTO
• man (8 ) wondershaper

Sit back, watch the video

and read more and more or more.

I’m not quite sure, yet, what I think of it, but putting the “Can it really be realised/implemented?” question aside, his idea really sounds stamin! I’ll definitely will have an eye on it and would love to see those ideas aroused!

By the way, the Drupal module it obviously started with is Activity Stream.

Side note: What do I tag this with? Where is wordpress’s option for the infinity-all-possible-ever-thought-of-tag?

In Drupal 6 this can be done with core modules like this:

1. enable Trigger module
2. add an action
3. add advanced action at the bottom and choose “Redirect to URL”
4. use description regardless of how you will use it but rather describing what this action does; e.g. “redirect to start node”
5. as URL apply “node” (without the quotation marks). Instead of node you can redirect to any url you like. See my screenshot for how it could look.
6. set-up the appropriate trigger
7. from the drop-down list at “Trigger: After a user has logged in” select your new action from just now
8. log out and back in again to test it

Note: In the links provided you need to change “your-domain-path-to-drupal” with your actual domain name to become something like http://example.com/admin. Or navigate as usual if you now where to find the settings pages in Drupal 6. If you happen to have clean urls disabled you might know already that you need to prefix the admin path (as every other path) by “?q=” so it all together looks like this: http://example.com/?q=admin. This, however, doesn’t concern the node parameter where you redirect to. That’s always an internal relative path without the leading slash; or some full url of corse.

Update 05/2009: If you want a simple module to do that for you useLogin Destination. To redirect user/1 to /admin and site users “back” to the page they logged in from the following PHP snippet should work for Drupal 6 (not tested, feedback welcome!):

global $user;
  if ($user->uid == 1) {
    // Redirect the Administrator
    return 'admin';
  } else {
    return ($_REQUEST['q']);
  }

Resources

• HowTo trigger Emails when Comment has been posted
• for advanced redirects see Login Destination module or Token module

All you need is the Windows Installer itself. Hit Win+R (command line dialog) and execute the following line (change file name and target folder, of course):

msiexec /a c:\tmp\MSIFileName.msi /qb TARGETDIR="c:\tmp\msitmp\"

You’ll find all files in your target folder.

Here are some more or less useful mashups (-lists) I stumbled upon that seam to be nice:

• Last.fm Mashups
• list of 36 last.fm mashups with short description

last.fm’s events function together with fusecal could be very usefull for bands’ websites to give visiters an easy way to be noticed only for concerts around there home town, e.g.

If you ever wanted to move your (very large) file that contains a Virtualbox’s guest hard drive (file extension is .vdi) to another location and did so just like that Virtualbox wouldn’t find it the next time you wanted to boot into your guest system. The only thing Virtualbox needs to be pointed to is the new location of that file.

The standart location of VDI files is (for Linux) ~/.VirtualBox/VDI/ (see global settings, where you could also change this if that’s all you want). Remember the old file name and close Virtualbox, just in case it would overwrite settings when closed after the following changes. Now let’s move one file to, say, /media/USBDrive/virtualbox/. Now do:

1. Use your favorite editor to open ~/.VirtualBox/Virtualbox.xml
2. Find the line that says something like:

   <VirtualDiskImage filePath="VDI/old file name.vdi"/>
   

3. Change it to point to your new location. So it should read something like:

   <VirtualDiskImage filePath="/media/USBDrive/new file name.vdi"/>
   

4. Done.

You need:

1. Old/original Windows XP installation CD (any of SP0 to SP2 will do even though only those from SP2 are supported officially). Make sure to use build 5512 or above.
2. Microsoft Windows SP3
3. unzipper like WinRar, unrar for  Linux / Ubuntu or the like
4. ISO creator / CD burn program like mkisofs, InfraRecorder, UltraISO, Basero (or others) or even old school
5. Boot image exctracted using BBIE or use this (also see Box.net box below)
6. ~ 1 GB free tmp space on disk

You do:

1. Extract / copy old Windows CD’s content (including hidden files!) to one folder (e.g. c:\XPCD)
2. extract SP3’s content to another folder (e.g. c:\XPSP3) using e.g. unrar, winrar or hit Win+R and type

   c:\XPSP3\windowsxp-kb936929-sp3-x86-enu.exe –x
   

   and select target folder, here c:\XPSP3

3. To slipstream the old CD do Win+R and copy+paste or type

   c:\XPSP3\i386\update\update.exe /integrate:c:\XPCD
   

4. Create bootable CD image or CD using the boot image and your updated folder c:\XPCD. I recommend using mkisofs (Windows or Linux executable) using

   mkisofs \
       -b cdboot/msboot.img -no-emul-boot -boot-load-seg 1984 -boot-load-size 4 \
       -iso-level 2 -J -l -D -N -joliet-long -relaxed-filenames \
       -V "WINSP" \
       -o ../winsp.iso .
   

   from within the root folder of the CD to be, i.e. c:\XPCD. You need to extract the El Torito image first. Create a new folder there and drop your boot image, i.e. cdboot/msboot.img. This can be done under Linux for example using geteltorito /dev/scd0 > cdboot/msboot.img (or use BBIE or IsoBuster in Windows or Wine).

5. Done.

You might want to try booting from the image using VirtualBox.

Resources:

• apcmag.com
• How to create a Windows bootable CD with mkisofs
• Command-line switches for Windows software update packages
• Windows XP SP3 final (5512) download
• Slipstream using Linux
• Slipstreaming Windows CD under Linux on Linux tune-up
• Slipstreaming Windows XP with Service Pack 3 in Linux from Jeremy Visser

Isn’t this just splendid?

If you ever wandered who was first, Firefox (FF) or Opera, in implementing the full text history search accessed in the address bar. In both, Opera and Firefox, the search covers at least page titles in addition to URLs. Bay the way I’m not talking about the feature called “nickname” or “keyword” in Opera and Firefox, respectively.

So far so good, as it’s a really nice feature and it doesn’t harm at all to have it in the best two browsers there are. But never the less I was curious as of who was actually the first to introduce the feature. Not that it’ll happen like with tabbed browsing or other really helpful function introduced to “the masses” by Opera.

Excursion on tabbed browsing

Only by the fact that people switching from IE to FF in lack of knowledge about Opera, Firefox has been awarded with being the inventor. Well, actually, it was more complicated than the simple FF vs. Opera. A project called NetCaptor in 1998 had tabbed browsing before others all though it was not a fully featured http web browser instead it used IE’s socalled Tradient Layout Engine. Opera had Multi Document Interface (MDI) before other browsers but tabbed browsing is claimed to have been in mozillas trunk before Opera extended their concept of multi docoment views. So I will close this side leap by breaking it down by a term by Adam Stiles:

“Actually, tabbed browsing is over 7 years old – Firefox, Mozilla, Opera, Safari and others can all trace their tabbed browsing DNA back to NetCaptor at some level.”

Back to Full Text History Search:

For one Opera 9.5 Alpha 3 introduced this feature publicly for the Norwegian browser in Sept. 2007. And as Pavel Studený lines out Opera not only searches URLs and page titles but also complete page contents (plus shows the last visit date in the result list). From trying out without knowing better so far FF 3 only searches URLs and page titles. Does any one know better about Firefox 3?

Sidenote: In Opera the index size for pages indexed in cache can be tuned through the Preference Editor by MaxVisitedPagesIndexSize (supposingly in KB, -1 means unlimited, i.e. limited by cache size I presume and 0 means deactivated). By the way, there is another way to access history search if you’d like to focus more on prettier results overview. And yet another hint for the use of Opera’s version: It sorts the results by hits on URLs followed by those in page titles and the like, thereby ignoring punctuations (all?). Hence, if you know right away you want to search titles or descriptions of pages only start with a punctuation like so: ;opera.

As much as I’m into open source and don’t like the consept of closed source software, Opera clearly is an exception! They even do really good ads:

(or download it)

Well, there am I trying to convince joomla 1.5 to use my template’s favicon instead of the default jommla flower . But no matter what it wouldn’t let me replace it by my own. What I’ve done so far:

• create the .ico file with Gimp, 32×32 (tried 16×16 also), 4 bpp 16-slot palette
• placed it in ../templates/my_template/favicon.ico
• reloaded page in browser

But still no favicon is shown in neither Opera nor Firefox under Windows.

Update: It seams I somehow used wrong colour palette, layer or whatever optioins. After I uploaded a png file to FavIcon and used the result it at least shows in Firefox. Opera seams to chuck up on the HTML header created by Joomla:

<head>
  [...]
 <title>Welcome to the Frontpage</title>

  [...]
  <link href="/joomla/templates/div_template/favicon.ico" rel="shortcut icon" type="image/x-icon" />
  [... repeated multiple times somehow ...]
  <link rel="stylesheet" href="http://localhost/joomla/templates/div_template/css/template_css.css" type="text/css"/>
  <link rel="shortcut icon" href="http://localhost/joomla/images/favicon.ico" />
  <link href="/joomla/css/template.css" rel="stylesheet" type="text/css" />
</head>

As far as my understanding goes Opera doesn’t mistaken as to overwrite the earlier favicon.ico link with the later and hence (as Opera does) show the correct, i.e. intended favicon for a glimpse of a second and than show none as the /joomla/images/ one is not there. If I place a copy in that directory on the server Opera also shows the icon — I asume the wrong one though!

Well, anyway, now I know where the rub is…

Update 2008/05/08: I should have digged into templating a bit further and not just take it “as is”. Now in the html header of .../templates/my_template/index.php I just leave out the line where it points to the joomla template but rather only have one “shortcut icon” href as below:

<head>
	<jdoc:include type="head" />

	<link rel="stylesheet" href="<?php echo $this->baseurl ?>/templates/system/css/system.css" type="text/css" />
	<link rel="stylesheet" href="<?php echo $this->baseurl ?>/templates/system/css/general.css" type="text/css" />

	<link rel="stylesheet" href="<?php echo $this->baseurl ?>/templates/<?php echo $this->template ?>/css/layout.css" type="text/css" />
	<link rel="stylesheet" href="<?php echo $this->baseurl ?>/templates/<?php echo $this->template ?>/css/typography.css" type="text/css" />
	<link rel="stylesheet" href="<?php echo $this->baseurl ?>/templates/<?php echo $this->template ?>/css/browserhacks.css" type="text/css" />
	<link rel="shortcut icon" href="<?php echo $this->baseurl ?>/templates/<?php echo $this->template ?>/icon/favicon.ico" />
</head>

Here is a forum post on how to make all incoming connections to your apache web server redirect to https, i.e. take encripted connections via ssl by using apache’s rewrite module.

Note 08/01/08: There have been issues after the original plugin has been updated. See Ubuntu Forum, Bug description (workaround or fixed deb for firefox only which is version 9.0.115!) or comments below for more. Components have been removed that also opera needs! Yet another example why closed source is bad… Hence you might want to give gnash a go, i.e. open source flash. The new Flash version is meant to work with opera version > 9.50 Beta, though (see bottom note). Anyway, here it goes for Flash version 9.0.48.0:

Note 2008/04/19: Before you get all frustrated about Flash and Opera you might enjoy operas’ ads.

Here we go

To install Adobe Flash Player after you installed Opera in Ubuntu, I found the best way is to, once again, use the debian way:

sudo aptitude install flashplugin-nonfree

After the install routine is done you need to add the path to plugins options in opera. Alternatively you could link there. To find where the new binaries are located do:

dpkg -S flashplugin-nonfree
app-install-data: /usr/share/app-install/desktop/flashplugin-nonfree.desktop
flashplugin-nonfree: /usr/lib/flashplugin-nonfree
flashplugin-nonfree: /var/cache/flashplugin-nonfree
flashplugin-nonfree: /usr/share/lintian/overrides/flashplugin-nonfree
flashplugin-nonfree: /usr/share/doc/flashplugin-nonfree
flashplugin-nonfree: /usr/share/doc/flashplugin-nonfree/changelog.gz
flashplugin-nonfree: /usr/share/doc/flashplugin-nonfree/copyright

Update 2008/04/16: The correct “list flag” for dpkg would be -L instead of -S:

dpkg -L flashplugin-nonfree | grep -i 'lib'
/usr/lib
/usr/lib/xulrunner
/usr/lib/xulrunner/plugins
/usr/lib/mozilla
/usr/lib/mozilla/plugins
/usr/lib/iceape
/usr/lib/iceape/plugins
/usr/lib/iceweasel
/usr/lib/iceweasel/plugins
/usr/lib/firefox
/usr/lib/firefox/plugins
/usr/lib/midbrowser
/usr/lib/midbrowser/plugins
/usr/lib/xulrunner-addons
/usr/lib/xulrunner-addons/plugins
/usr/lib/flashplugin-nonfree
/var/lib
/var/lib/flashplugin-nonfree

/Update

Alternatively you could link the lib’s binary to Opera’s plugin directory:

sudo ln /usr/lib/flashplugin-nonfree/libflashplayer.so /usr/lib/opera/plugins/

Some say you may need to restart opera in order for plugins to actually work. Fortunally, for me it work right away. In opera’s address field type opera:plugins to see what opera knows about flash.Update: See this blog on bleeding edge info on plugin’s development status if interested.

Ressources:

• as always: man pages
• Launchpad bug report
• Adobe’s Linux Flash blog
• Ubuntu Community Help on restricted formats
• Ubuntu Community Help on Opera browser flash problems

Update: This works for 7.04, a.k.a. Feisty Fawn, and 7.10, a.k.a. Gutsy Gibbon.

Update 2008/04/16: On a side note: There is the option reinstall for aptitude if one wants to make sure the newest files are all in the right places.

Update 2008/04/19:I stumbled upon the close to be release of Opera 9.5 which is currently in beta state (and has even more great features once again before Firefox has them ). Supposingly the Debian package should get flash working. I tried the i386 version for Gutsy and it did work for me.

Update 2008/06/28: Here are some command line parameters you can start Opera with. Especially useful would be -debugplugin. To use it you have to open a terminal to see the additional information:

opera -debugplugin [Enter/Return Key]

This will show what needs to be set-up and installed to use a secure line from a Linux box (eg. Ubuntu) to a Windows box via SSH-tunneled VNC but without the load of Cygwin installed on Windows. I used the nicely small package SSHWindows.

SSH server for Windows (on Windows machine)

1. Download SSHWindows and run the installer. An alternative could be WinSSHD from bitvise. It’s 30 days trail and closed, though. You’ll be prompted with the warning to edit the passwd file. Read quickinstall.txt or readme.txt for more details located in the install folder for %PROGRAMFILES%\OpenSSH\docs (hit WIN-KEY+R and copy&paste the path there for quick access).
2. From a prompt cd to %PROGRAMFILES%\OpenSSH\bin. (WIN+R and type cmd, hit ENTER, c: ENTER, cd %PROGRAMFILES%\OpenSSH\bin)
3. Run the following (replace <username> with the Windows username that should log in from Ubuntu):
   mkgroup -l >> ..\etc\group
mkpasswd -l -u <username> >> ..\etc\passwd
4. Start opensshd as Windows service:
   net start opensshd
5. Open incoming port in Windows firewall:
   netsh firewall add portopening TCP 22 "OpenSSHd"
   The “OpenSSHd” bit can be chosen individually; it’s only a string to identify this entry.
6. Test login locally with eg. PuTTY and than test it from the Linux box (ssh winuser@winip). You might need to do some firewall (Windows and/or iptable) config. If your Linux box has to go through some kind of router/firewall machine you’ll most likely have to add port forwarding on that firewall to pass port 22 (SSH port) to the windows machine’s IP.

Install TightVNC (on Windows machine):

1. Don’t forgett to click the options to setup VNCServer as Windows service and start it after installation.
2. Open TCP port 5900 temporarily for testing like for opensshd:
   netsh firewall add portopening TCP 5900 "VNCincoming"
3. Test it from Ubuntu with vncviewer <windows-machine-ip>
4. If it works close the port in Windows firewall. You won’t need that hole any longer:
   netsh firewall delete portopening TCP 5900

• Configure tunneling VNC through SSH (on Linux box):

1. ssh -L <local port>:<remote computer>:<remote port> <user>@<remote ip> and vncviewer 127.0.0.1
2. Test vnc connection again using -via option: vncviewer -via user@host localhost:0

• Use compression in ssh?
• GNOME applet/shell skript?

References:

• Ubuntu guide to set up Ubuntu and Windows using Cygwin
• Tunnel VNC through SSH
• SSHWindows
• TightVNC (VNC Server for Windows) with their Win32-Documentation
• VNC over SSH : securing the remote desktop
• Command Line Manipulation of Windows XP SP2 Firewall
• Information on the vncviewer -via option
• SSH Tunneling Made Easy
• Using VNC Tunneling over SSH

While compressing a set of single files is fairly easy (one only needs to add ‘.gz’ or similar to the end of “file name strings”) the oposite is not so easy. Nevertheless it can be done doing:

for i in *.gz; do echo extracting $i ...; sudo su -c "gzip -dc $i > ${i:0:${#i}-3}"; done && ls *xpm

sudo su -c "" is for Ubuntu systems, ${#i}-3 sais “length of i minus 3″ which makes ${i:0:${#i}-3} to become each file name without trailing .gz.

Ressources

• Bash by Example
• man 8 bash section “Parameter Expansion” -> “Substring Expansion”

One important thing to know before doing anything else:

Every byte written to partitions in question will decrease chances to get data back since deletion of files and even partitions does not automatically mean actually deleting that data on disk. In most cases it only means deleting administrative entries in file or partition tables. But writing new files or partitions on the very same disk might actually overwrite data blocks containing pieces associated with files still intact! The second thing you might want to consider: If you mistakenly deleted single files or even a bunch of them look somewhere else but better not reboot until you really know why you have to do so as rebooting in those cases will sometimes also mess up chances to get back your data. Here I will only handle partition or hard drive errors.

So the very first step will be to get hold of extra storage (like USB drives), boot up some Live CD, e.g. your Ubuntu installation cd. If you have liability to paranoia you might even want to physically detach your hard drive and use some USB case to access it instead. First of all do something like

ddrescue -vr-1 /dev/sda recovered_data_blocks.img gddrescue.log

using gddrescue. Adjust parameters to your needs, especially /dev/sda (complete drive) or /dev/sda1 (partition in question). For Ubuntu you need to install gddrescue (= GNU ddrescue) package first. gddrescue will create an image trying hard to copy every data block still intact so you can, at any point, restore the drive stage where you first discovered you lost data. This, or course, can be used with any block-oriented medium such as CD-ROMs or DVDs. You might want to specify “-b 2048″ for CDs. Also use -n to get the most data on first run. For subsequent attempts you might want -rX where X is the number of retries for erroneous areas. I recommend to use -vr-1 for verbose infinite retries. gddrescue first reads as many as possible intact blocks and then splits error areas with each subsequent run. Note though for partitions or even complete hard drives it will take hours so be patient and make sure to use gddrescue’s log file option! With other tools I tried it took even more time which makes sense since gddrescue reads only blocks that really need to be read.

Second you should — just in case — save your partition geometries with fdisk (output similar):

$ sudo fdisk -ls
Password:

Disk /dev/hda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1        9145    73457181    b  W95 FAT32
/dev/hda2            9146       19106    80011732+  83  Linux
/dev/hda3           19107       19457     2819407+   5  Extended
/dev/hda5           19107       19457     2819376   82  Linux swap / Solaris

Disk /dev/hdb: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System

Disk /dev/hdc: 20.8 GB, 20847697920 bytes
255 heads, 63 sectors/track, 2534 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hdc1   *           1        2427    19494846   83  Linux
/dev/hdc2            2428        2534      859477+   5  Extended
/dev/hdc5            2428        2534      859446   82  Linux swap / Solaris

After ddrescue has finished try TestDisk for lost partitions which, among others, looks for back up partition tables, inode tables, and the like. To restore plain data there are heaps of tools. Most notably foremost and PhotoRec. Note though that for lost partitions there is no way to really know what file type found blocks belong to or even the name of associated files’ paths, at least as far as I can imagine. File names really are — in all file systems I know — only attributes of a data segment called file (or inode) such as access date, ownership and such. Sometimes file names are even stored in special files (directories or folders) which means there data blocks need to be intact and it has to be known where they are! The scenario I ran into was I mistakenly installed Ubuntu on top of Windows XP (NTFS partition) instead of resizing the partition as intended. TestDisk even though listing a NTFS partition (from it’s back-up MFT located at the end of NTFS partitions) couldn’t however restore the partition as such. Running Microsoft’s chkdsk stored a bunch of files with their filenames several folders into one called found.000 (I ran it inMicrosoft’s recovery command line from CD after manually through fdisk changed partition type to NTFS/HPFS, e.g. x07). Using the above mentioned tools I could restore some more but without there original path or file names. All together I recovered ~40 GB out of probably 60 GB data (which included system files).

Resources

• Tincho’s Debian Package of the Day: gddrescue
• Pat Patterson’s article on Ubuntu hard drive recovery (stating John Gilmore to suggest GNU shred instead of /dev/urandom to securely shred data on dead hard drives)
• Find deleted or lost partitions using testdisk
• Ubuntu Wiki on Data Recovery
• On toad.com: “Disk drive recovery“
• Heaps of info on filesystems and mounting (especially section about FS checking) as part of a larger site about Ubuntu/Windows dual-boot set-ups; has a section on TestDisk with illustrated walk-throughs
• hachoir-subfile is a tool based on hachoir-parser to find subfiles in any binary stream.
• About damaged Superblocks (extfs based), what superblocks are and how to use backups of them stored throughout the partition
• From German Ubuntu User Wiki: “Notfall“, “Festplatten Problembehebung“
• From German Linuxwiki: “verlorene Partition finden“
• man pages from ntfsprogs in Linux-NTFS Wiki (ntfsck is not ready, yet)

Further reading:

• On a side note: Why *nix FS don’t need defragmentation and on Fragmentation and Unix file systems
• Another side note: Ubuntu Forum entry on the various mount/fstab options
• Easiest Way To Restore Deleted FAT and NTFS Logical Drives

Google Analytics is a fairly new service from google for site administrators/webdevelopers to monitor their site usage easily and free of charge. This is done by appanding a script tag in your html file (or so your site script’s add it to the code they produce) right before the end of the </body> (the UA-something is your individual Google Analytics user agent id so I x’ed it out not to vilify the source):

<script src="http://www.google-analytics.com/urchin.js"; type="text/javascript">
</script>
<script type="text/javascript">
_uacct = "UA-xxxxxxxx-1";
urchinTracker();
</script>

However some might not want to reveal such information (or data in the first place). You can direct your browser via a locally installed instance of privoxy and set a roule in user.action saying:

{ +block +handle-as-empty-document }
.google-analytics.com/urchin.js

Daniel even suggests to filter it out in the first place so to not even load the html code needed to get the script of googles’ site:

FILTER: google-analytics Remove Google Analytics JS.
s|<script\s[^>]*?google-analytics.com/urchin.js[^>]*>.*?</script>||gis
s|\burchinTracker\(\);||gis

This would go into the file default.filter.In privoxy’s version 3.0.5-beta-1 this issue is supposed to be included, anyway. But unfortunatelly it seamed not to work for me. At leased the html source code still includes the relevant script section. Maybe privoxy filters out the communication. But on the other hand privoxy doesn’t normally know about communication done via java (and java script also?). I’m uncertain here and would love clarification from readers. If you run privoxy you’ll get more information on your instance by calling config.privoxy.org (which really is filtered out by your local proxy and run locally, since you most likely will have opted to enable bypassing proxy on local traffic in your browser this is somewhat consequent). I’m new to privoxy but this looks like the script should be blocked. But why is it still there? So I tested it and found bypassing the proxy when calling the remote script directly you get the script’s source code displayed — nothing special so far. But when I turned on proxy settings in my browser with only the above user.action lines I only get a blank page. So I guess it means it will only block the content of the script not occurrences in <script>-tags. But the important thing here is the script never makes it into my local memory so it can’t be executed.
Ressources:

• Documentation on block

Just a short note on this right now:

Audio can be extracted with mplayer using -dumpaudio option (low quality), ffmpeg tool with -ab and -ar options or online for youtube videos at vixy.net.

Quick video converter flv2mpg using ffmpeg is shown at Linux by Example, too.

Update: Another great open source program is MediaCoder which even has a special audio edition.

Ressources

• Linux by Example audio
• Linux by Example video
• online extraction at vixy.net

While searching for a promt command for bash to trimm long pwds (current working directory) I stumbled uppon “Blog.ubrious“. After a little hacking I adopted it to work for linux bash. It also cuts off leading characters when pwd is longer than 20 characters with build-in commands only. Plus I opted to use a ‘@’ as dilimeter between user name and host name so to rather have ssh style. Here is what I came up with:

PROMPT_COMMAND='PS1="\[33[0;33m\][\!]\`if [[ \$? = "0" ]]; then echo "\\[\33[32m\\]"; else echo "\\[\33[31m\\]"; fi\`[\u'@'\h: \`if [[ ${#PWD} > 20 ]]; then echo ${PWD:$((${#PWD}-20))}; else echo "\\w"; fi\`]\$\[33[0m\] "; echo -ne "33]0;`hostname -s`:`pwd`07"'

If wordpress does mess up the code (which I hope does not happen) please visit the original blogger’s post since he was able to upload a text file (I’m not, unfortunatelly).Here is a small list on what it can do for you and a little demo:

1. Changes to red if the last command didn’t have a return code of 0
2. Includes your bash history # for easy history command repeating. Follow the link to find out how to use !!, !$ and !number.
3. Makes sure path length doesn’t exceed 30 regardless of what the base name is (bit after last fwd slash).

The only small hassle about it is even though it uses \w it wouldn’t abreveate my home directory as ‘~’ for me.

Note 2008/05/14: If you want to use this promt command with screen, too, make sure to test $TERM for ’screen’. For example mine reads:

case "$TERM" in
xterm*|rxvt*|screen*)
     PROMPT_COMMAND=...