Look, it’s really not that hard.

Programs are still in the same place, in %ProgramFiles%, unless you need the 32 bit version, which is in %ProgramFiles(x86)%, except on a 32 bit machine, where it’s still %ProgramFiles%.

All those dll’s are still in %SystemRoot%\System32, just now they’re 64 bit. The 32 bit ones, they’re in %SystemRoot%\SysWOW64. You’re with me so far, right? Oh, and the 16 bit ones are still in %SystemRoot%\System – moving them would just be weird.

Registry settings are in HKLM\Software, unless you mean the settings for the 32 bit programs, in which case they’re in HKLM\Software\Wow6432Node.

So the rule is easy: stick to the 64 bit versions of apps, and you’ll be fine. Apps without a 64 bit version are pretty obscure anyway, Office and Visual Studio for example[1]. Oh, and stick to the 32 bit version of Internet Explorer (which is the default) if you want any of your add-ins to work. The ‘default’ shortcut for everything else is the 64 bit version. Having two shortcuts to everything can be a bit confusing, so sometimes (cmd.exe) there’s only the one (64 bit) and you’ll have to find the other yourself (back in SysWOW64, of course). And don’t forget to ‘Set-ExecutionPolicy RemoteSigned’ in both your 64 bit and 32 bit PowerShell environments.

Always install 64 bit versions of drivers and stuff, unless there isn’t one (MSDORA, JET), or you need both the 32 bit and 64 bit versions (eg to use SMO / SqlCmd from a 32 bit process like MSBuild). Just don’t do this if the 64 bit installer already installs the 32 bit version for you (like Sql Native Client).

Anything with a ‘32’ is for 64 bit. Anything with a ‘64’ is for 32 bit. Except %ProgramW6432% which is the 64 bit ProgramFiles folder in all cases (well, except on a 32 bit machine). Oh and the .net framework didn’t actually move either, but now it has a Framework64 sibling.

I really don’t understand how people get so worked up over it all.

[1] Ok, so there is a 64 bit version of Office 2010, but given the installer pretty much tells you not to install it, it doesn’t count.

Via Cup(Of T).

As I’ve often stated I prefer Linux, using Windows only when I must. However, from an administrative perspective it’s really helpful if while using Linux for various administrative tasks, one can streamline their work environment and engage in some common tasks such as starting or stopping Windows services at will from Linux.

To get a list of all available services on a Windows PC or Server, type the following from your Linux command line:

net rpc service list -I IPADDRESS -U USERNAME%PASSWORD

If you have a complicated password that uses symbols (such as ! # @, etc) you will find that entering the password (even in “quotation marks”) will not work, you will have to leave the @PASSWORD blank, and just enter the USERNAME, you’ll then be prompted to enter the password manually. Also note, some services may have spaces in their name. If so, simply “enclose the service name in quotes” to start or stop that service.

If on a domain . . .

net rpc service list -I IPADDRESS -U "domainname\username"

You will then be prompted for the password. Once you’ve authenticated, the list of services will scroll on your screen.

To stop any service:

net rpc service stop SERVICENAME -I IPADDRESS -U USERNAME%PASSWORD

or if on a domain

net rpc service stop SERVICENAME -I IPADDRESS -U "domainname\username"

To start any service:

net rpc service start SERVICENAME -I IPADDRESS -U USERNAME%PASSWORD

or if on a domain

net rpc service start SERVICENAME -I IPADDRESS -U "domainname\username"

You can do more than stop or start services. This functionality stems from SAMBA on Linux. You can add and remove users remotely, change user passwords, kill print jobs, show all users for a specified group, list all groups, shutdown the server or PC, shutdown-and-restart the server or PC and much much more: just type “man net” for more information, however, here are a few gems . . .

To list all the shares on a PC or Server (example):

net rap share -I 192.168.0.5 -U "mydomain\john"

To list the Print Queue on a PC or Server (example):

net rap printq -I 192.168.0.5 -U "mydomain\john"

To get the name of the server you’re accessing (example):

net rap server name -I 192.168.0.5 -U "mydomain\john"

To list ALL the open SMB/CIFS sessions on the target computer (example):

net rap session -I 192.168.0.5 -U "mydomain\john"

To reboot the server or PC and force all apps to shutdown gracefully:

net rpc shutdown -r -f -I 192.168.0.5 -U "mydomain\john"

These commands can easily be scripted with or without variables (for the IP addresses) to speed up the process.

From their home page:

BleachBit quickly frees disk space, removes hidden junk, and easily guards your privacy. Erase cache, delete cookies, clear Internet history, remove unused localizations, shred logs, and delete temporary files. Designed for Linux and Windows systems, it wipes clean 70 applications including Firefox, Internet Explorer, Flash, Google Chrome, Opera, Safari, Adobe Reader, APT, and more.

It is available for most Linux distributions. Here is a great write-up on it from Linux Magazine.

Once a professor has chosen to customize a textbook, it gets a unique URL allowing students of the class in question to download or publish on-demand the customized textbook. I found the subject catalog a bit limiting right now, but I would expect that to grow over time. This site is still worth examining if one is an educator or student looking for community driven, affordable teaching/learning materials. Some authors also put out podcasts on their books, accessible from the site. I’m also sure Flatworld Knowledge would enjoy hearing from some who are interested in writing a textbook of their own for peer review and publication by them.

I noticed there aren’t any textbooks about computer science: perhaps some out there is willing to change that!

]]> http://www.lylebackenroth.com/blog/2010/04/19/remixable-textbooks-by-peer-reviewed-authors-for-community-use-in-education/feed/ 0 http://www.lylebackenroth.com/blog/2010/04/16/easily-find-your-hardware-specifications-and-some-system-monitoring-commands-in-linux/#utm_source=rss&utm_medium=rss&utm_campaign=easily-find-your-hardware-specifications-and-some-system-monitoring-commands-in-linux http://www.lylebackenroth.com/blog/2010/04/16/easily-find-your-hardware-specifications-and-some-system-monitoring-commands-in-linux/#comments Fri, 16 Apr 2010 12:43:30 +0000 lyle http://www.lylebackenroth.com/blog/?p=582 When a PC or server is running Linux, you often want to know exactly what sort of hardware is actually running inside the box and more importantly whether it is supported by the kernel. Here is a list of commands which should help you to learn about your system and some of its specifications. In some cases, these commands may not work as listed below if you’re running a Red Hat or Fedora based distribution. In those instances simply specify the path to the command which will be /sbin/command.

If any of the output runs off your screen, just add |more to the end of any of these commands to see the output one screen at a time and hit the spacebar to go to the next screen, or Q to quit.

Processor type:
$ cat /proc/cpuinfo

Is the processor using 32 or 64 bit instruction set:
$ cat /proc/cpuinfo | grep flags | grep lm
If you get some output you have a 64 bit CPU. If you receive no output, then you’re using a 32 or even 16 bit CPU. The reason this is the case is that the CPU yields many flags that tell Linux what sort of processor it is, and the lm flag informs Linux that the CPU is a 64 bit processor. Grep as a command filters output. Feel free to run this command without the grep suffixes (cat /proc/cpuinfo) to see the full output of your CPU details.

What hardware (audio, video, disk controllers, etc) is in my Linux box:
$ lspci -tv
(The -t switch groups similar devices together for easy reading and -v offers more verbosity.)

To easily filter out the above command to just show graphic card information:
$ lspci | grep VGA

What USB devices are plugged in:
$ lsusb

Check the size of the hard drive and what hard drives are available in the system.
This command will also list USB drives and sticks. You need a root permissions to execute the fdisk command:
$ sudo fdisk -l | grep GB

Show info about a particular hard disk including firmware revision (replace sda with the appropriate drive as listed from the above command):
Note: This will only work on internal disks, NOT USB drives.
$ sudo hdparm -i /dev/sda

Check what partitions and file system is in use on my hard drives (same as the above command, but essentially more verbose):
$ sudo fdisk -l

Locate CD/DVD-ROM device file which offers a CD/DVD-ROM’s make and model info:
$ wodim –devices
or
$ wodim –scanbus
The above command will scan your entire system bus for attached devices (this won’t include USB Devices as they are not direct-bus-attached devices).

What modules are currently loaded:
$ lsmod

get a information about any particular module:
$ modinfo module_name

remove modules:
$ modprobe –remove module_name

load a modules to the kernel:
$ modprobe module_name

What hardware is using which module.
The -v switch is for vebosity, where -vvv is EXTRA verbosity.
$ lspci -v
or
$ lspci -vvv

Check for PCMCIA cards:
$ lspcmcia

How much RAM is installed in my Linux and how much of it is in use (megabytes).
It will also include swap memory:
$ free -m
There is a gigabyte switch, but it *rounds* it down, so it isn’t very accurate for RAM info:
$ free -g

Check sound card settings. This command will reveal whether your sound card is installed and what modules are in use:
$ cat /dev/sndstat

Available wireless cards:
$ iwconfig

What speed is set to FANs:
$ cat /proc/acpi/ibm/fan
If this command doesn’t work, then feel free to peruse the /proc/acpi directory on your system. You will find info available on your CPU, AC Adapter, Battery, etc. Some info is available here, and your mileage may vary for viewing any of the files in /proc/acpi.

Get a battery information on your laptop (assuming it’s been installed):
$ powersave -b

To find out what Linux Kernel you’r running:
$ uname -a

To find out what distribution of Linux you’re running:
Run any of these commands, as depending on your distribution some may or may not work.
$ cat /etc/issue
$ cat /proc/version
$ dmesg | head -1

Get a recent history of system reboots:
$ last reboot

To open any file from command line using the default application (will launch the correct graphical application for the file, as though you had doubled-clicked the file graphically):
$ xdg-open ./filename

To monitor all active network connections, and update live every second:
$ watch -n.1 ‘netstat -tup’

To passively list all connections, active or inactive:
$ ‘netstat -tupl

http://savevideo.me/

Saves the movie as a .FLV (Flash Video) file.

Current photocopiers can produce copies very rapidly because they scan the page only once and store it digitally on its internal hard disk. It uses that image file to then print copies using similar technology found in laser printers. Indeed, many copiers today can function as a direct printer for your PC (or even e-mail your document directly from the copier) which requires a network connection; this means many units can be addressed remotely and is therefore vulnerable to remote perusal.

For personal and private documents, a personal scanner & printer (at home) might be the wiser choice.

Here are some very useful commands, that any power user would find helpful:

1. Start a simple webserver to serve up any directory as browsable from anywhere (for file transfers):

$ python -m SimpleHTTPServer

I’ve mentioned this in past posts. This is a simple command, that when run from any directory will launch a simple python web server that will serve up the local directory as a browsable directory using a browser such as Firefox or Chrome. Any subdirectories underneath the local directory from which this command is run will also be browsable. You can right-click and save any file or left-click it to attempt to view it on the fly. This works very well over SSH sessions, when you want to transfer a file, but don’t want to engage SSHFS or SCP. You can background the process with a ctrl-z, bg, then pkill python to stop the web server from running, or just leave it running in command prompt and ctrl-c to end it.

2. Record your desktop and pipe the output to an mpeg file.

$ ffmpeg -f x11grab -s wsxga -r 25 -i :0.0 -sameq /home/john/desktop.mpg

• -f allows ffmpeg to grab the data properly from the x11 framebuffer
• -s sets the size of the screen to actually record, starting from the upper left of the screen. Here wsxga denotes a specific preset resolution (in wsxga’s case that would be 1600 x 1024). You can however type any resolution you like in manually (e.g. -s 1024×768). You will need to know the resolution of your desktop to set this correctly.
• -r sets the framerate. This could be left out as 25 is the default.
• -i sets which framebuffer to take, since XWindows can run in multiple sessions, generally you’ll want to leave this setting alone.
• -sameq forces the same quality was what is being fed in by the source (in this case the x11 framebuffer). This is helpful to have a max-quality video, though you may want to try other settings to degrade the quality to keep the file size down. If you’d prefer to reduce the quality on the fly, replace -sameq with -qscale x where x is 1 – 31. These are preset quality settings, with 1 being the highest and 31 being very poor video quality. I have found -qscale 10 to be the sweetspot between quality and file size.
• If you’d like the file to be a bit smaller and if you prefer an .AVI to a raw .MPG, then simply remove the /home/john/desktop.mpg in the command above and replace it with:
  • -vcodec mpeg4 /home/john/desktop.avi
    • This is file will be a bit smaller using the mpeg4 codec in an avi container. You can still use the -qscale option with this change.

3. Copy an entire directory tree through ssh using on the fly compression through an SSH session (no temporary files!):

$ ssh <host> 'tar -cz /<directory>/<subdirectory>' | tar -xvz

Just enter the <host> to SSH to, and the host’s <directory> and <subdirectory> path to compress that subdirectory on the fly at the host, but decompress it as it arrives locally to your current location and path. This will have the advantage of not taking up any extra space at the host (since the files are compressed as they’re transmitted) and easily drops the entire directory tree specified onto the client uncompressed, saving time and bandwidth and transmission time.

This works well for large directory trees and is easy to use for a quick copy where you don’t want to spend a lot of time compressing it at the host manually and transmitting the compressed file, then uncompressing it, then deleting the original compressed file created at the host. Note: This will replicate the full directory path at the client side (desired).

SCP or RSYNC are recommended for automated backup though, this is more appropriate for a 1-shot copy of a large directory.

4. Resize any image files in the current directory to Width x Height specifed (regardless of image format)!

$ for a in `ls`; do echo $a && convert $a -resize <Width>x<Height> $a; done

Simply do a man convert to learn more about the convert program, other options can be added into the command. Also this is a great syntax for doing ANYTHING to any files in a particular directory that would be a batch process consistent with all the files in that directory.

5. Grab a screenshot of the current desktop to the current directory

$ import -pause 5 -window root desktop_screenshot.jpg

This command will wait 5 seconds (assuming you want some time to set up the shot and to get the command prompt out of the way) and take a snapshot of the root (primary) desktop currently running. This command requires imagemagick be installed.

Being an obvious proponent of Open Source (also known as FOSS), I generally use only Linux and Open Source software. I own an Android phone, my home machines run Linux and wherever possible I try to deploy Open Source software professionally where possible & appropriate. I’ve never owned an Apple/MAC or an iAnything. In fact, my Sansa e280 media player runs Rockbox, the Open Source Jukebox Firmware for media players instead of the closed source software shipped with it. I have owned Windows systems and played with DOS in my youth, but once I reached the age of liberation I made a conscious choice to walk down the less trodden path and have reaped the rewards for it.

We’re all interdependent and this fact is ignored by many. Both Microsoft and Apple deny that the very foundations of their closed source products are rooted in the collaboration of the community, rooted in Free and Open Source Software (FOSS). Indeed, Apple’s OS is based on FreeBSD, while .NET (Microsoft’s primary application framework) is clearly drawing its inspiration from JAVA.

UNIX is one of the seminal operating systems which in many ways has influenced the world in which we live and I contend, moreso than Apple or Microsoft. In some of its core applications under the hood, some Windows code is based on FreeBSD. Simply click here for an example of which there are many, or this link, or this link. Although not a majority of it; I wouldn’t want to demean BSD by drawing parallels between the two <smirk>.

Of course as we all know, Apple is based on FreeBSD. Mac OS X is based upon the Mach kernel, parts of  FreeBSD’s and NetBSD’s implementation of Unix were incorporated in Nextstep, the core of Mac OS X. See this link for more info (Wikipedia).

Internalizing these facts in consideration helps me to realize that raw creativity, intelligence, community and ingenuity can provide great fulfillment, certainty and happiness in many spheres.

Having said all of the above, reading this article brought a smile to my face. It is a summary of Jonathan Schwartz’s blog post which can be read in its entirety here.

(Launchpad link):

A dynamic tunnel SSH multiplexer. When heavily using a Dynamic SSH tunnel, this application will open concurrent SSH tunnels to multiplex the load. This is useful when using torrent connections locally, or when using your computer to share internet access via the dynamic proxy.

To install on Ubuntu Karmic:

sudo add-apt-repository ppa:martineve/ppa

sudo apt-get update

sudo apt-get install sshsplit

If no arguments are passed, you can run sshsplit from command line and it will bring up a convenient GUI for on the fly configuration.

In the event of a failure when you need to do a restore, you can order a drive to be mailed back to you (2 day priority) or download the data you need off their servers.

They also offer a nice little interactive table showing their pricing structure against other popular services where you can modify the amount of data you want to store to see how the pricing would change across different providers.

Crashplan offers a variety of plans that either count or don’t count the number of machines being backed up. Accordingly, plans vary from $4.50/month to $8.33/month depending on your needs. I have not yet tried the service, but I may consider it for backing up vital files to a secure off-site location.

I know of some folks who prefer services like Carbonite, but they don’t seem to support Linux. Another alternative, Jungledisk (front end to Amazon’s S3 cloud) has a Linux client for their backup server product, but I’ve never tried it. I have tried Jungledisk for Windows servers, and it works well, but Amazon meters the data being transferred to and from their cloud whereas Crashplan does not.

Ubuntu is running an application called “landscape-common”.

More on this application here. The easy thing to do here is to simply type update-motd – -disable and you can then modify your MOTD. Also I have noticed that sometimes, the contents of motd.tail will overwrite the MOTD, so I would simply make sure whatever you want in /etc/motd is also in /etc/motd.tail. [On Debian systems, the system message of the day is rebuilt at each startup. /etc/motd.tail is the file to edit permanent changes to the message of the day].

Ultimately, I have settled on a system known as eCryptfs. Of course, this runs only on Linux. However Windows/MAC users could access encrypted data on a Linux server if the decrypted data were presented with a SAMBA share.

eCryptfs is a kernel-native, stacked cryptographic filesystem for Linux. This means that it will run seamlessly with an existing Linux install and its filesystem. A stacked filesystem is one that is layered ontop of an existing filesystem (such as a transparency laid over a page beneath). As data is read from or written to the disk, data is encrypted or decrypted on the fly.

The flexible part of eCryptfs is that it embeds the cryptographic metadata into the header of each file. The benefit of storing the cryptographic metadata into each file is that any one file can be given to a friend, or sent through e-mail or copied by any other means and the recipient can conveniently decrypt the file so long as they have correct key (password).

Most encryption programs are not this versatile. They require special software or require that the file be separately encrypted so that it could be transmitted, and even then the recipient needs to jump through many hoops to decrypt the file. The only exception to this is PGP or GPG. GPG makes is very convenient to transmit files, but does not work well on large directories of files. eCryptfs bridges this gap very nicely. Also, since eCryptfs uses a stacked filesystem, there is no limit to what can be put into the directory for encryption, or subdirectories. They will simply and naturally fill the drive like any file would without any preset encrypted container limitations.

In Ubuntu (or any other Debian based distro) the following steps will allow one to easily encrypt an entire drive, directory or file.

To begin encrypting and decrypting your data, simply install the ecryptfs utilities.

sudo apt-get install ecryptfs-utils

Once installed, create a directory mystuff (or any name you like). This will be where you’ll store your data to be encrypted. The directory can be made anywhere, your home directory or any storage device (USB key or USB hard drive). It is important to note that you cannot encrypt a directory with data already in it. The easy way to accomplish this is to follow the steps below, then move the data from the original directory to the newly encrypted directory. You can rename the newly encrypted directory to match the original once the files have been moved and the original directory deleted.

mkdir ./mystuff

To be extra safe here, be sure only your Linux user has rights to the files in the directory. To accomplish this, simply change the permissions on the directory. The commands below assume you’re already in the directory where your new directory was just created (like your home directory). You may need to specify the full path to the directory if you’re not executing the command from that location.

chmod 700 ./mystuff

Now, you just have to leverage the encryption already available in your Linux kernel. To do this, you must layer the encrypted transparency, if you will, over the unencrypted directory. This is done by re-mounting the directory with the encrypted transparency layer.

sudo mount -t ecryptfs ./mystuff ./mystuff

This command simply remounts the exact same directory, however with the encryption overlay in place. From this moment forward, any files written to the mystuff directory will be encrypted. Also any files read from the directory will be decrypted on the fly (until the transparency is removed by unmounting the transparency, but more on this later.) Until the directory is dismounted from its encrypted transparency layer, the files will be easily readable and silently encrypted/decrypted on the fly.

Once the above command is executed, eCryptfs is going to ask some questions. The answers to these questions dictate the nature of the encryption.

It is perfectly safe to keep hitting <enter> on every one of these questions. This will use the defaults which are very well selected. There is one exception however. One question asks if you’d like to enable filename encryption. The default answer here is no. In many cases, the filenames themselves offer a lot of information about its contents and that alone is more than many want revealed. For example, a filename named “Bank Account PIN numbers 2009” would certainly be a target file and while helpful for you in organizing your data, would be too much information to reveal if anyone were able to get a directory listing of the files in question. To prevent this, answer yes when eCryptfs asks to enable filename encryption (again, the default will be to not scramble the filenames).

One other question which might confuse is the plaintext passthrough question. If enabled, this option allows non-encrypted files to be used inside the mount, which to me defeats the purpose of an encrypted directory. Allow for the default answer to this: no.

At the end of the process, eCryptfs will alert that this is the first time you have used your passphrase, and will ask if it can save a hash of it. It is safe to answer yes to this question. If keeping a hash of your passphrase is a source of concern, then I would encourage more research on the subject.

At this point, you may write, delete, read as much data into that directory as you’d like. The files will remain free to access until you dismount the encrypted layer, leaving you with the closed, encrypted files. To dismount the transparency, simply dismount the directory.

sudo umount ./mystuff

At this point, any attempt to read the files will fail. You can browse the encrypted files themselves, but the filenames will be scrambled random characters and the contents will be totally incomprehensible.

To reopen your encrypted files, simply remount the encrypted directory as we first did earlier. However, upon doing this eCryptfs will ask all the same questions it did before (key type, your passphrase, the cipher, and the key length), so it will know the parameters of this particular encrypted directory. It will ask these questions every time you attempt to mount your encrypted directory. Fortunately, this can all be automated (except the passphrase entry obviously) so as to speed up the process.

The command can be given ahead of time and written into an executable script:

sudo mount -t ecryptfs /home/johnny/mystuff /home/johnny/mystuff -o key=passphrase,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_passthrough=n,ecryptfs_enable_filename_crypto=y,ecryptfs_fnek_sig=ed221f243b153323

Be mindful of the last option in the command above, namely ecryptfs_fnek_sig. When you first encrypt your directory, eCryptfs will tell you what the ecryptfs_fnek_sig is for your specific directory (or drive). You’ll need to enter this unique number into your command so that you will have a smooth and quick mounting process. Type this entire command into a text file (obviously replacing /home/johnny/mystuff with the actual path to your encrypted directory and entering your unique ecryptfs_fnek_sig number), save it (I’ll call mine crypt) and make it executable by typing:

chmod +x ./crypt

While you’re at it, create a quick script to dismount the encrypted mount.

sudo umount /home/johnny/mystuff

Then make it executable using the chmod command as shown above.

Of course in Linux you can also create a custom application launcher (a graphic on your taskbar or desktop) that can execute these scripts with the click of the mouse.

Not every EEE PC is built the same, nor do they use the same video drivers. Therefore first, you have to find what the minimum and maximum resolutions are available for your unit. To see this, simply type this in command line:

xrandr

As an aside, the commands below work with any Linux system, EEE or otherwise. This command will tell you the minimum and maximum resolution of your screen plus the available “standard” resolutions.. mine were:

Screen 0 (the local screen): min 320×200 ………. current 1024×600 ……… max 1024.x1024

Available standard modes were: 1024×600, 800×600 and 640×480.

To max out my screen resolution I chose to work with 1024×1024, that would give me the most pixels (+ the most panning) but it would show me more of an application in a glance. Normally working in 1024×600 (native resolution of the EEE PC 1000HE) I’d have to hit F11 to go to full-screen mode in Firefox. Now, running in 1024×1024, I can run without full screen mode and can see a nice portion of my browser window. The panning isn’t much of a bother, and I feel less constrained on the desktop.

To change the resolution to the max specified by running xrandr above, type this:

xrandr --output LVDS --panning 1024x1024

. . . and voila !  Instant pan/scan screen. To change it back to the original resolution …

xrandr --output LVDS --panning 1024x600

Place these two commands in separate scripts with execute rights, then attach to a launcher and place on your taskbar and/or desktop and you can do this in one click.

###

UPDATE: On Ubuntu 9.10, this command WORKS, however, the local display is now LVDS1, not LVDS.

They’re sorted newest-first, so click the <previous entries> at the bottom of the page to see the prior scripts.

Here’s also a few links on learning the basics of shell scripting:

IBM’s extensive site on the subject.

Linuxcommand.org

Simply sudo apt-get install cpulimit. More info can be found here.

Using GNOME

• Get to the System->Preferences->Keyboard menu.
• Select the “Layouts” tab and click on the “Layout Options” button.
• Then select “Key sequence to kill the X server” and enable “Control + Alt + Backspace”.

Click the link below for the full article and how to do it in KDE.

Source: Ubuntu Geek.

I recently had to run a ReiserFsck myself on one of my primary home Linux boxes off a Live-CD; worked very well!

Here’s the link for reference:

NOTE: The above link is just a broad stroke introduction to some of the more commonly used repair functions, a lot more research is needed by the user if in-depth recovery of a hard disk or repair is required.

Don’t forget to chmod +x ./script-name on each.

Script 1

#!/bin/bash
#
# Dump m4a to wav (first step in conversion)
for i in *.m4a
do
mplayer -ao pcm "$i" -aofile "$i.wav"
done

Script 2

#!/bin/bash
#
#Second step... use lame to convert into .mp3

for i in *.wav
do
lame -h -b 192 "$i" "$i.mp3"
done

Script 3

#!/bin/bash
#All the m4a's are now mp3's, however..
#the file will look like "filename.m4a.wav.mp3"
#So, to clean that up we remove extraneous extensions.

for i in *.mp3
do
x=`echo "$i"|sed -e 's/m4a.wav.mp3/mp3/'`
mv "$i" "$x"
done

While FreeNX and NoMachine’s NX server are out there, NoMachine’s NX server is not free, and FreeNX according to Google, was a bit top heavy and difficult to maintain. I see this as an exciting development.

It is now available for download.

Here’s the article on it.

Here’s where you can download it.

To do this simply check out the carrier listing and look for your carrier. Then email TheNumber [at] carrier’s-doman.com (example) and you’ll SMS that phone.

It’s a pretty basic tip, but I’ve met people who think they need a cell phone (or an IM client) to SMS a cell phone and fortunately, this is not true.

The same Wikipedia page explains how to send E-Mails via SMS using a carrier’s special SMS email code.

Cheers.

For videos recorded off TV this command works well and keeps the video scaled properly:

mencoder input_file -o output_file.mp4 -of lavf -lavfopts format=mp4 -ss 1 -vf pp=ci,scale=432:324,crop=432:320,harddup -ovc x264 -x264encopts crf=30.0:nocabac:level_idc=30:global_header:threads=2 -ofps 30000/1001 -oac faac -faacopts mpeg=4:object=2:br=128:raw -channels 2 -srate 44100 -af volnorm

This isn’t an elaborate HowTo, otherwise I might break down each command switch. Check the man pages on mencoder for details on each of the switches. This does work, however.

For videos ripped from DVDs you own, (generally 16:9 ratio), this command works very well (really only the scale of the video has changed):

mencoder input_file -o output_file.mp4 -of lavf -lavfopts format=mp4 -ss 1 -vf pp=ci,scale=480:270,expand=480:272,harddup -ovc x264 -x264encopts crf=30.0:nocabac:level_idc=30:global_header:threads=2 -ofps 30000/1001 -oac faac -faacopts mpeg=4:object=2:br=128:raw -channels 2 -srate 44100 -af volnorm

This will keep the letterbox scale without stretching the video. You can play with the scale= ratios but the numbers in the above commands work pretty well. A 90 minute video ends up transcoded to about 210-220megs, which fit pretty well on today’s micro SD’s (my G1 has an 8gig micro SD). Though I wouldn’t want to watch too many movies on such a small screen (nevermind the battery life issues).

In the case where you may have ripped the entire DVD contents to a hard disk and want to transcode from a hard disk rip to h264, replace the input_file in the above command with the following:

-dvd-device /home/john/rips/GROUNDHOG_DAY/VIDEO_TS dvd://x

Where you replace your path to the rip instead of /home/john/… and where dvd://x is the DVD title (the primary movie is usually 1, so dvd://1). This will transcode the entire move of a ripped DVD to h264. You can also do this directly off a dvd simply by inserting the dvd and in place of input_file in the above command, simply type: dvd://1.

Top 100 open source gems part 1

Top 100 open source gems part 2

While not complete and listing too many games (I’ve never seen Linux as a very good gaming platform), it’s still worthy of a post.

python -m SimpleHTTPServer &

This will launch a very simple web server in the directory from which the command was run, and will establish that directory as root. You can then access it from your local machine by typing in this URL in your browser: http://127.0.0.1:8000/

By default, it starts the web server on port 8000 but that can be changed using:

python -m SimpleHTTPServer 9090

which starts the server on port 9090, and can be accessed via the browser or any HTTP client using:

http://127.0.0.1:9090/

If you want to access these files from outside your home network, I’d recommend SSH with a local port redirect instead of raw port forwarding, which I do talk in a roundabout way here.

For any that are interested, this is my .screenrc

hardstatus alwayslastline
hardstatus string '%{= kG}[ %{G}%H %{g}][%= %{=kw}%?%-Lw%?%{r}(%{W}%n*%f%t%?(%u)%?%{r})%{w}%?%+Lw%?%?%= %{g}][%{B}%Y-%m-%d %{W}%c %{g}]'
#
# Default screens
# syntax: screen -t NameOfScreen ScreenNumber ShellCommand
screen -t "Work SSH" 0 /home/name/workssh
screen -t "Home 1" 1
screen -t "Home 2" 2
screen -t "Home 3" 3
screen -t "Home 4" 4

The hardstatus string gives me the local computer’s hostname on the left, lists the shells themselves in the middle, and on the right offers the date and time.

Line 6 with “Work SSH” executes the shell script “workssh”, labels the window “Work SSH” and assigns it to virtual shell number 0. This shell script allows me to SSH to one of my work servers offering me a series of local listening ports that forward to remote IP’s and ports.

Shells 1-4 are local bash shells.

Assuming you have VirtualBox remote port forwarding engaged (which will forward ports into the VM, for example if you’re running Windows XP as a VirtuaBox VM and you want to RDP into it on port 3389), I discuss port forwarding on VirtualBox hosts, here. Though VirtualBox supports a quick and easy VRDP option to enable for easy RDPing into a box without having to do any of the complex port forwarding, my port-forwarding post explains how to forward other ports to your VM for any other applications or if you want to RDP into your Windows VM on a port other than 3389.

To engage the VM over an SSH session, simply type:

VBoxHeadless -startvm "Name of VM Here"

You can also force VirtualBox’s VRDP (virtual RDP) via command line by adding the switch “–vrdp on”, though it’s usually on by default.

If you’re not sure of the name of the VM, simply type

VBoxManage list vms

Once running, you can simply run …

rdesktop localhost:3389

Assuming you have a -L 3389:ip-address-of-VirtualBox-host:3389 in your original SSH command, and you can now RDP into your Windows XP box which would be running in a VM over Linux.

Source: HowToForge

Of course this 6th sense would be culled from the Internet and its plethora of information, focused sharply into your daily life, as you live it.The video is illustrative of what our world might look like in 20 years and how different it could be from today.

“HOW wonderful that we have met with a paradox. Now we have some hope of making progress.” So said Niels Bohr, one of the founders of quantum mechanics. Since its birth in the 1920s, physicists and philosophers have grappled with the bizarre consequences that his theory has for reality, including the fundamental truth that it is impossible to know everything about the world and, in fact, whether it really exists at all when it is not being observed. Now two groups of physicists, working independently, have demonstrated that nature is indeed real when unobserved. When no one is peeking, however, it acts in a really odd way.

Click the link above for the full article.

Solution 1

We are going to use qemu-img tool to this.QEMU disk image utility

First Install qemu  qemu-img is included with qemu package using the following command

sudo apt-get install qemu

Convert a VMWare Image to VirtualBox Image

Convert VMWare image called whatever.vmdk to /tmp/debian.bin (or a path of your choice).

qemu-img convert debian.vmdk /tmp/debian.bin

Now use VBoxManage to get back image in native format:

VBoxManage convertdd /tmp/debian.bin debian.vdi

Solution 2

VirtualBox can run VMs created by VMware Workstation or Server for this you need to import vmdk files using the following procedure

• Start Virtual Box

• Goto File > Virtual Disk Manager

• Click Add.  Locate and select the copied .vmdk file. Click OK.

• Create a New VM as usual using the added vmdk file

• Boot the VM

lsof +D /media/disk1

This will return the command and process ID of any tasks currently accessing the /media/disk1 directory. You can then locate them, or use the kill command to finish them off.

People sometimes have to do a reinstall of their Ubuntu system for various reasons (been playing/experimenting with configuration/drivers/other packages or just because something is badly broken) but remembering all the extra packages you have installed can be a chore – but here is the simple solution:
On your old system (assuming it is still working), start up Synaptic and go to:

File-Save Markings and choose a file name along with a location (like a USB drive) that you can use when you have installed your new system)

This file contains a list of all your currently installed packages, and when you have installed and booted up your new system (and configured your repositories to the best for your location ) then start up Synaptic and go to:

File-Read Markings and point it at your saved file, and after that has completed then select Apply to kick off the download & installation of all of those packages you had installed previously!

There are also apt-get command line functions that achieve the same outcome, so those who don’t have/use Synaptic can still do this.

You will still have to do any special configuration changes that you had on the old system, but at least all of the packages are now in the new system.

This is also very handy for moving to new hardware/duplicating setups etc.

Be aware that doing this between different Ubuntu versions may cause complications because some packages may not be in a later version or have different names.

Note:- Don’t forget to backup your sources before you reinstall.

sudo cp /etc/apt/sources.list ~/sources.list.backup

Otherwise if you have added any PPAs or other sources, this tip won’t work.

Bonding is creation of a single bonded interface by combining 2 or more ethernet interfaces. This helps in high availability and performance improvement.

How to setup dual-dual bonding (two bonds of two interfaces each) on Ubuntu as quickly as possible.

1. Add two lines to /etc/modules

bonding bond0 -o bond0 mode=1 miimon=100

bonding bond1 -o bond1 mode=1 miimon=100

If you’re very good at managing your time, just remember that miimon’s option determines how often the bond is monitored for failure and that mode can be one of:

0 – Round robin balancing

1 – Active back-up

2 – Transmit based on MAC address for load balancing/fault tolerance

3 – Broadcasting – provides fault tolerance by transmitting on all slave interfaces

4 – Aggregates links, assuming all nics support same speeds and duplex settings

5 – Transmit load balancing – balancing is handled by the bond based on load

6 – Same as 5, but also uses arp to balance load “better

2. Install the ifenslave package if you haven’t already. You can use apt-get to grab it if you don’t:

sudo apt-get install ifenslave-x.x

3. Ensure that the package actually installed:

sudo dpkg –get-selections | grep enslave

ifenslave-x.x install

4. Set up your interface files:

# cat /etc/network/interfaces (only including the parts you probably need – substitute IP addresses, netmasks, etc):

auto lo

iface lo inet loopback

auto bond0

iface bond0 inet static

address 10.10.125.88

netmask 255.255.255.0

network 10.10.125.0

gateway 10.10.125.1

post-up ifenslave bond0 eth0 eth2

pre-down ifenslave -d bond0 eth0 eth2

auto bond1

iface bond1 inet static

address 10.10.127.88

netmask 255.255.255.0

network 10.10.127.0

gateway 10.10.127.1

post-up ifenslave bond1 eth1 eth3

pre-down ifenslave -d bond1 eth1 eth3

5. Add lines to the bottom of your architecture’s modprobe files, reboot
and pray:

sudo cat /etc/modprobe.d/arch/i386

alias bond0 bonding

options bond0 mode=1 miimon=5000 max_bonds=2

alias bond1 bonding

options bond1 mode=1 miimon=5000 max_bonds=2

Most people think you need to kill your SSH session to add a new -L option, then reinitiate the SSH session; this is NOT true.

You can open an internal SSH shell within an SSH session to add new redirects!

From within an SSH session, simply type:

~# then hit <enter>

~C then hit <enter>

Then type: help and <enter>

You’ll see a listing of available commands. To add a new local redirect, just type

-L 4567:192.168.0.12:5900, then hit <enter>

…and voilà, you’ve added a new local redirect. Just hit <enter> once, and you’ll be dropped back into command line.

There are other escape-commands. Just type ~? from within an SSH session for more escape-commands.

FYI: This also works for remote redirects, as well.

Here’s a Google search link offering more info:

Here’s a link to Clonezilla SE (Server Edition).

Ext4 which has now been declared stable, and no longer experimental, will be the successor to the long-standing ext3. It can support a file system up to 1 exabyte in size (that’s 1,048,576 terabytes to everyone else) and single files up to 16TiB.

Ext4 is likely to become the defacto standard file system in most Linux systems, perhaps except the most mission-critical of servers whose admins will likely opt for a file system longer in the tooth (like ext3 or XFS). Ext4 will likely be the file system to go head to head with SUN’s ZFS.

Kernel 2.6.28 will also support laptop disk shock protection, and the minstrel WIFI rate control algorithm.

More details on the other improvements here, and here.

Some more details here, which are easier to digest.

This link explains how it’s used at Last.FM. Read the comments below, as they’re just as insightful as the artcile.

A couple of helpful links to set up your own IRC server.

A very basic how-to, with no advanced configs.

A good Ubuntu Forum discussion on the subject.

General Link 1, General Link 2

Using Screen & IRSSI.

eCryptfs is a POSIX-compliant enterprise-class stacked cryptographic filesystem for Linux.It provides advanced key management and policy features. eCryptfs stores cryptographic metadata in the header of each file written, so that encrypted files can be copied between hosts; the file will be decryptable with the proper key, and there is no need to keep track of any additional information aside from what is already in the encrypted file itself. Think of eCryptfs as a sort of “gnupgfs”.eCryptfs is a native Linux filesystem. The kernel module component of eCryptfs is part of the Linux kernel since 2.6.19.

The author of this Wired article Kevin Poulsen is an editor of Wired magazine and a former hacker who served five years in prison for breaking into FBI computers.

–

A related article from 2001.

Details (PDF): http://tinyurl.com/56j63s.

More here: http://tinyurl.com/8erk74.

From the site:

The attack is essentially a variant of the chopchop attack used against WEP secured networks, which surfaced in early 2005. The name “chopchop attack” is a nod to the KoreK-developed chopchop tool, which allows the user to decrypt an arbitrary encrypted data packet without having to know the WEP key.

This app supports multiple channel (and you can navigate between them simply by swiping your finger left/right) and supports multiple IRC servers.

Project page here:

If you’re looking to convert your videos from .avi or .mpeg format to the highly efficient .3gp format (natively supported by the Google Android OS, running on phones such as T-Mobile’s G1), then look no further than this application. The application runs on Windows & Linux!

Click here for their site, the links to the application are at the bottom of the page.

Click here to conveniently download the Ubuntu .deb file for the application (4.4 megs).

Abstract.

Full text (PDF).

Here’s also a good HowTo crack WPA.

Here’s a video of it:

Here’s the blogpost on it:

It is a complete solution for every organization to create, collaborate, share and publish all its internal and external documents.

You and your team can create and collaborate on:

• Text documents
• Spreadsheets (coming soon)
• Presentations
• Task Lists
• E-mails
• Calendars
• Web Links

All it requires is an xampp server (essentially a Linux server). I am going to test this with some colleagues and see how viable it is for a production environment, but on the surface it looks to be worth evaluation.

You can try a demo here. Once the spreadsheet function is available, this will become much more interesting.