Archives 2014

EDIT: Flumotion is no longer suitable for modern Ubuntu distros such as Ubuntu 18.04 or 20.04 onwards. Use MistServer instead.

Flumotion Streaming Server is a great open-source application that is available in the Ubuntu repositories that can easily allow you to broadcast a live stream from a video camera, or broadcast pre-recorded media. The end-user can view this media in any capable HTML5 web browser such as Google Chrome.

Unfortunately Flumotion (version 0.10.0-1 at the time of writing) relies on some deprecated Twisted Python network functions that prevent the software from working properly on any release of Ubuntu from 13.04 and upwards.

The obvious solution is to simply install Flumotion under Ubuntu 12.04 but then you will find that Flumotion in the 12.04 repository is buggy and out of date anyway, requiring you to update Flumotion from the official developer PPA to the stable release that is already in Ubuntu 14.04.

There is a way to get Flumotion working properly under Ubuntu 14.04 however, without too much fuss. Essentially all you need to do is downgrade the three affected Twisted Python packages down to 11.1.0, which is the version from Ubuntu 12.04.

Here’s how you do it.

WARNING: Ubuntu has a high reliance on Python. By downgrading to an older release, you run the risk of other parts of Ubuntu that rely on Python either breaking or behaving unusually.

So far I have only found the Flumotion Assistant UI to suffer some minor issues with rendering text fields, preventing you from adding values for things like framerate which will upset Flumotion because that data is missing, but you should be able to get around it by generating the XML configuration elsewhere (I will update this article in due course once I’ve done more testing).

I would recommend that you dedicate a PC to be used as your Flumotion server so you don’t have to install other applications or regularly have to perform updates.

Please also be aware that the next time you perform a package update, Python is likely to be upgraded to the current release automatically again, but you can follow these instructions from Step 3 to downgrade Python again afterwards.

1. First up, install Flumotion as normal:
   
   $ sudo apt-get install flumotion
   
2. Once it is installed, we now need to download three Python packages from Ubuntu 12.04 that we are going to downgrade to:
   
   $ wget -c http://au.archive.ubuntu.com/ubuntu/pool/main/t/twisted/python-twisted-bin_11.1.0-1ubuntu2_amd64.deb
$ wget -c http://au.archive.ubuntu.com/ubuntu/pool/main/t/twisted/python-twisted-core_11.1.0-1ubuntu2_all.deb
$ wget -c http://au.archive.ubuntu.com/ubuntu/pool/main/t/twisted-web/python-twisted-web_11.1.0-1_all.deb
   
   (Note: If you are using 32-bit Ubuntu, change “amd64″ to “i386″ for the “python-twisted-bin” download)
   
3. Now we need to uninstall the newer version of Python components that is currently installed without uninstalling the applications that rely on it (basically we’re going to force the system to break its dependencies):
   
   $ sudo dpkg -r --force-all python-twisted-bin python-twisted-core python-twisted-web
   
4. Now let’s install our replacement downloaded packages:
   
   $ sudo dpkg -i *.deb
   
5. Finally, let’s restart Flumotion:
   
   $ sudo service flumotion restart

That’s basically it. You can now start the Flumotion Administration interface and this time the Manager and Workers will all start without an issue this time (login with the default username and password of “user” and “test” respectively).

As before, remember that installing future system updates to the system will automatically upgrade the three Python packages we just changed to their current releases which will break Flumotion, so just go back to step 3 to undo that and reinstall the older packages.

This issue will be resolved once Flumotion is updated to no longer use the deprecated network-related functions in Twisted Python.

Pat yourself on the back. Job done.

The XScreensaver packages are a series of fancy alternate screensavers that have a popular history. They are much more enjoyable than the boring default Ubuntu screensaver which is just… a black screen.

Unfortunately the XScreensavers package hasn’t really been updated in awhile and doesn’t integrate very nicely into the current flavours of Ubuntu without some manual tweaking, so that’s exactly what I’m going to cover right here.

Issues to deal with

This document will cover the following:

• Installing the XScreensaver packages Configuring Ubuntu to use XScreensaver instead of the default gnome-screensaver
• Configuring Ubuntu to lock the screen with the XScreensaver
• Fixing the bad fonts issue in XScreensaver Setting a custom RSS feed for text-based XScreensaver packages

These instructions have been tested on Ubuntu 12.04 (Precise Pangolin) and 14.04 (Trusty Tahr).

Making it happen

1. Open a terminal.
   
2. Uninstall the boring default Ubuntu screensaver with:
   
   $ sudo apt-get remove gnome-screensaver
   
3. Install the XScreensaver packages with:
   
   $ sudo apt-get install xscreensaver*
   
   (note the asterisk on the end to install all xscreensaver packages)
   
4. Open the Dash (Ubuntu logo at the top-left of screen) and type in the word “start”. An icon will appear referring to “Startup Applications”. Click on it.
   
5. The window that appears shows which applications will be started when you login to your machine. Click on the “Add” button.
   
6. In the new window that appears, type “XScreensaver” into the Name field, then type in “xscreensaver -nosplash” into the Command field, then type in “Start the XScreensaver” into the Comment field.

7. Click on the “Add” button and then click on the Close button on the previous window.
   
8. That takes care of starting the XScreensaver, so now let’s fix the lock screen keyboard shortcut. Click on the Dash again and type in “keyboard” and then click on the “Keyboard” icon.
   
9. In the window that appears, click on the “Shortcuts” tab.
   
10. At the bottom of the left pane, click on “Custom Shortcuts”.
    
11. Click on the “+” button to add a new custom shortcut.
    
12. Give the shortcut a name, eg: “Enable the lockscreen”.
    
13. In the Command field, type in “xscreensaver-command -lock” and then click on the Apply button.
    
14. You will now see your new shortcut listed, but it doesn’t have a keyboard combo for it yet, so click on the word “Disabled” with your mouse and it will change to “New accelerator…”.
    
15. Now using your keyboard, press the key combo you’d like to use to lock your PC and start the XScreensaver. The default combo is CTRL+ALT+L but you can use any combo you like. If you do use CTRL+ALT+L you will be told that it’s already in use by the Gnome-Screensaver (which you uninstalled earlier, remember?), so just tell it to reassign it to your shortcut.
    

16. Close the keyboard settings window.
    
17. Now we need to sort out the fonts. The way XScreensaver looks for fonts is not like any other application. It needs to have a predefined list of available fonts, so we need to provide that list. We will get the “Ubuntu Font Family” (that comes with current releases of Ubuntu) enabled for use in XScreensaver, but you can apply this to any of the font folders on your machine.
    
18. In your terminal, type in the following:
    
    $ cd /usr/share/fonts/truetype/ubuntu-font-family
$ sudo mkfontscale
$ sudo mkfontdir
    
19. Repeat the above for all the fonts you wish to add to your system, eg: substitute the path /usr/share/fonts/truetype/msttcorefonts for the Microsoft fonts from the ubuntu-restricted-packages meta-package or the ttf-mscorefonts-installer package.
    
20. Create a new file (or edit any existing file) as follows:
    
    $ sudo nano /usr/share/X11/xorg.conf.d/50-fonts.conf
    
21. Type/paste in the following into your new file:
    
    Section "Files"
    FontPath "/usr/share/fonts/truetype/ubuntu-font-family"
EndSection
    
22. Add as many FontPath entries you need between the Section/EndSection block for all the fonts you want available that you ran step 18 on.
    
23. Save your changes with CTRL+X, then “Y” and then Enter.
    
24. Now type in the following to enable the fonts now (or simply reboot):
    
    $ xset +fp /usr/share/fonts/truetype/ubuntu-font-family
$ xset fp rehash
    
25. Repeat the xset +fp <path> command as many times as required to add all the fonts you setup in Step 18 before the xset fp rehash command, or simply reboot to do them all in one hit from your X11 config file in step 21.
    
26. Now we’re ready to fix the fonts in XScreensaver. In this example we’re going to fix the fonts in the StarWars screensaver. What exactly is wrong with the fonts in the StarWars screensaver I hear you ask?
    
    Simply this:
    

27. Click on the Dash and then type in “screensaver”. An icon called “Screensaver” will appear below it. Click on it.
    
28. In the Screensaver Preferences window that appears, scroll down the list of available screensavers to find “StarWars”. Click on it to highlight it.

29. A preview of the screensaver will appear in the pane on the right. You will notice that the font in the screensaver looks awful as in the above image.
    
30. Click on the “Settings…” button. A new window will appear.
    
31. In the Settings window, click on the “Advanced>>” button at the bottom. The window content will change.

32. You will see the command line that starts the screensaver. Modify the line so that it looks like:
    
    starwars -root -font "-misc-ubuntu-bold-r-normal--180-0-0-0-p-0-iso8859-1"
    
33. Click OK and repeat this modification to any other screensaver that uses a proportional font in its text, for example the FlipText screensaver.
    
34. Finally, let’s set a custom RSS feed for the screensavers that use text so that they show something useful. Click on the “Advanced” tab in the Screensaver Preferences window.
    

35. At the bottom-left in the “Text Manipulation” section, make sure “URL” is selected and change the URL text to your favourite RSS feed’s URL, for example ITNews’ RSS feed for “all content” is:
    
    http://www.itnews.com.au/RSS/rss.ashx
    
36. Test the StarWars screensaver now by clicking on the “Display Modes” tab and then select “StarWars” from the left pane to make it appear in the preview window. The time the fonts should look much nicer as follows:

37. Now go through the list of screensavers, enabling and disabling those that you want to use. As you click each one, its preview will appear on the right.
    
38. Set the Blank After, Cycle After and Lock Screen After values accordingly, eg: 10 minutes a piece.
    
39. Close the Screensaver Preferences window and test locking your PC by pressing CTRL+ALT+L or whatever combo you set in step 15, and your screen should fade out and start displaying a random screensaver from your list of enabled screensavers. When you move the mouse or press a key, a login prompt should appear.
    
40. Pat yourself on the back. You are done.

Choosing your own font to use instead of the Ubuntu Font Family fonts

1. Choosing your own font is simple. For each set of fonts that you processed in Step 18, type in the following, using the Ubuntu Font Family as this example:
   
   $ cat /usr/share/fonts/truetype/ubuntu-font-family/fonts.dir
   
2. This lists all the possible fonts available for that family. Copy to the clipboard the font description you wish to use.
   
3. Paste the description as the font argument in the command line of the screensaver you wish to modify.Note that you will need to adjust the font size/quality value in your command line because they are rendered as scaled bitmaps, not outlines. For example, in Step 32 we specify the font size to be “180” so that the fonts appear smooth and clean when scaled. If you don’t specify this, then the font will be generated into a bitmap using the smallest size before being scaled up in the screensaver, resulting in pixelated fonts.
   
   SPECIAL NOTE: Some screensavers require proportional fonts to be used and others require fixed-width fonts. If you try to use the wrong type of font, the screensaver will likely crash.
   
4. Choose the appropriate font type from the list of available fonts.
   
5. Preview your screensaver and make adjustments as required. If you’d like to test the screensaver directly without running up the Preferences tool, launch the screensaver binary in a terminal with the font description as an argument.
   
   For example, for the StarWars screensaver, you can run it in a window as follows:
   
   /usr/lib/xscreensaver/starwars -font "-misc-ubuntu-bold-r-normal--180-0-0-0-p-0-iso8859-1"
   
6. Pat yourself on the back again. You are done.

Darik’s Boot and Nuke (abbreviated as DBAN) is a popular tool used by many organisations and individuals to securely erase hard-drives prior to disposal, or perhaps just to fix Windows problems  . It typically comprises a small 15MB ISO image that you can burn to CD or make a bootable USB stick from so you can boot up a PC on it and set about erasing all detected storage devices.

When you’re doing a lot of machines, however, booting a CD is tedious, especially when you accidentally scratch the disc and need to burn a new one. Using a USB stick and either misplacing it, or forgetting to remove it before erasing starts means you lose the content of the boot stick too.

Wouldn’t it be nice to be able to simply boot DBAN from the network so it’s always available whenever you need it and have it automatically use your preferred options instead of being manually run each time?

Pre-requisites

• A copy of DBAN. You can get it from the project site here. I will be using version 2.2.8 in this article.
  
• A working Linux PXE server. If you’ve not built one before, you can use my previous guide here.
  
• A sacrificial hard-drive or a virtual machine to test with. You will be completely destroying the data on the drive. When this exercise is over, there will be nothing recognisable on the drive so operating systems will typically recognise the drive as a brand new, never-before-used drive.
  
• The PC housing the sacrifical drive needs to have the ability to boot from PXE. All modern computers built in the last 15 years should be able to do this.

Let’s get it going

1. First up, we need to extract DBAN’s files from the ISO image since we’re not going to burn it to a disc. Open the downloaded ISO image in Archive Manager by right-clicking on it and choose “Open with Archive Manager”.
   
2. Extract the following files: DBAN.BZI and ISOLINUX.CFG
   
3. On your PXE server, assuming you have all your files under /srv/tftp as per my previous tutorial, make a new folder called “dban” under it:
   
   $ mkdir /srv/tftp/dban
   
4. Now copy over the DBAN.BZI file you extracted in Step 1 to the /srv/tftp/dban directory. You don’t need to copy ISOLINUX.CFG because we’re simply using that for boot command reference.
   
5. Now rename the file so that it’s all in lowercase:
   
   $ mv /srv/tftp/dban/DBAN.BZI /srv/tftp/dban/dban.bzi
   
   (We don’t actually need to do this, but since everything else in the Linux world is typically in lower-case, we may as well do the same here)
   
6. Now make sure that the permissions are set for TFTP correctly:
   
   $ sudo chmod 777 -R /srv/tftp
   
7. Now let’s setup a simple PXE menu boot option that is simply going to write zeros across all detected storage devices when you boot up on it (which is the fastest method of wiping while remaining secure). Open your PXE boot menu config file. If using my previous tutorial, then that will be:
   
   $ nano /srv/tftp/mybootmenu.cfg
   
8. Scroll to the bottom (or insert where you’d like to have it) and add the following lines:
   
   LABEL Auto ^Nuke EVERYTHING With Zeros NOW! No Questions Asked!
KERNEL dban/dban.bzi APPEND nuke="dwipe --autonuke --method zero" silent
   
9. Press CTRL+X, then Y and then Enter to save your changes.
   
10. Boot up your sacrificial system into PXE. When your menu appears, you should see a new entry called “Auto Nuke EVERYTHING With Zeros NOW! No Questions Asked!” and the “N” character will be highlighted to indicate the keyboard shortcut for it.
    
11. Use the arrow keys or the keyboard shortcut to launch DBAN. It should boot quite quickly since it’s such a small application.
    
12. You will see a lot of text appear while the system boots up, enumerating hardware and searching for storage devices. At this time, any attached direct-writable storage mediums such as hard-drives and USB sticks will become targets for DBAN. Network drives/shares and other PC’s on your network will not become targets.

13. Once the system has detected everything it can find, DBAN will begin. All detected storage devices will be listed on their own line and will show their erasure status. You will notice that all this starts automatically and with no further interaction from you.
    
14. Once the system has completed erasing all devices, it will advise accordingly and halt the system. Your drives are now securely erased!

Additional Options

So you might be wondering, what did we need the ISOLINUX.CFG file for if we weren’t going to use it? Will, this is just for your reference – it contains all the command line parameters for all of the other options that DBAN offers you for the truly paranoid data hoarder. Please note that these additional options are superfluous – hard-drives are magnetic devices that can only hold one set of ones and zeros. Overwriting the drive multiple times with sequential or random ones and zeros is not going to make the erasure any more or less secure. Once a drive is wiped with just one pass of ones or zeros or a random combo, it is impossible to recover any data from it, and you certainly cannot “unformat” it or “unwipe” it.

To save you some time, here’s a complete list of the extra options presented as a sub-menu for your PXE boot menu. Simply copy and paste it into your boot menu configuration, or pick and choose the options you want.

Note: To prevent accidental erasing of a system from PXE boot, the default menu option is set to run DBAN in manual mode where you are asked to choose which drives you wish to erase, which gives you a chance to back out.

# ================================================================
# BEGIN: SECURE HDD ERASE OPTIONS
# ================================================================

menu begin Secure HDD erase options
 menu title ^Secure HDD erase options
 label mainmenu
 menu label ^Back..
 menu exit

LABEL Auto ^Nuke EVERYTHING With Zeros NOW! No Questions Asked!
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method zero" silent

LABEL ^Manual Setup of Wipe Options
 MENU default
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe"

LABEL ^Default 3-Pass Random Wipe (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke" silent

LABEL US Dept Defence ^Standard Wipe Method (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method dod522022m" silent

LABEL US Dept Defence ^3-Pass Wipe Method (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method dod3pass" silent

LABEL US Dept Defence Short Wipe Method (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method dodshort" silent

LABEL Peter ^Gutmann Wipe Method (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method gutmann" silent

LABEL ^RCMP TSSIT OPS-II Wipe Method (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method ops2" silent

LABEL ^Paranoid 8x Wipe with Full Verify (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method prng --rounds 8 --verify all" silent

LABEL PRNG Stream ^8x Wipe Method (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method prng --rounds 8" silent

LABEL ^Quick Wipe - Not 100% Secure (AUTO)
 KERNEL dban/dban.bzi
 APPEND nuke="dwipe --autonuke --method quick" silent

menu end

# ================================================================
# END: SECURE HDD ERASE OPTIONS
# ================================================================

Happy erasing! 

IBM Notes (formerly Lotus Notes) is a corporate email and database collaboration tool. It’s still popular and widely used, and at the time of writing is now up to version 9.0.

Unfortunately IBM have a bad habit of assuming no-one uses 64-bit operating systems (yes, even in 2014), so with the exception of the Apple OS X version which doesn’t have a 32-bit version at all, IBM continues to compile the Linux and Windows versions as 32-bit only applications.

Installing the 32-bit Linux version does not work on 64-bit Ubuntu/Debian systems “out of the box” because of some hard-coded 32-bit only pre-requisites. This article will describe how to modify the installer so that it will work on 64-bit systems.

Pre-requisites:

• A copy of the full release of the IBM Notes 9.0 client package for Debian-based Linux distributions. This is a tar file. As this is commercial software, I obviously cannot provide you a link to this, but your company’s Notes Administrator will be able to source this for you.
  
• A 64-bit Ubuntu system to install to. In this article, I will be using the desktop version of Ubuntu Linux 12.04.4 LTS.

PLEASE NOTE: This instruction does NOT work on Ubuntu 14.04 at this time due to missing 32-bit dependencies in the Trusty repository.

Process:

1. Download the IBM Notes 9.0 package for Ubuntu/Debian Linux as normal. It’s a TAR file called NOTES_9.0_LINUX_DI_EN.tar (523MB). Only a 32-bit package is available.
   
2. Extract the content of the tar archive into a working directory:
   
   $ mkdir notes9linux
$ cd notes9linux
$ tar -zxvf /path/to/NOTES_9.0_LINUX_DI_EN.tar
$ ls -l
   
   You should have the following files:
   
   ibm-notes-9.0.i586.deb
ibm-cae-9.0.i586.deb
ibm-connections-4.5.0.i586.deb
ibm-activities-9.0.i586.deb
ibm-sametime-9.0.i586.deb
ibm-opensocial-9.0.i586.deb
licence.tar
smartupgrade.sh
   
3. Delete the “licence.tar” and “smartupgrade.sh” files as we don’t need them.
   
4. Create a new folder in your working folder called “ibm-notes-9.0.i586″ (do not put “.deb” on the end).
   
5. Rename the “ibm-notes-9.0.i586.deb” file to “ibm-notes-9.0.i586_ORIGINAL.deb”.
   
6. Open the “ibm-notes-9.0.i586_ORIGINAL.deb” file in Archive Manager (or any other archive management tool) and extract the contents of it to the “ibm-notes-9.0.i586″ folder you created in Step 4. You should now have the following directories in there:
   
   DEBIAN
opt
usr
   
7. Get into the “DEBIAN” folder.
   
8. Open the “control” file in a text editor.
   
9. Go down and modify the “Depends:” line to REMOVE the following part of that line: “gdb, coreutils, unzip, bash, procps, grep, sed,”. When you’re done, the line should now look like:
   
   Depends: libart-2.0-2, libasound2, libatk1.0-0, libbonobo2-0, libbonoboui2-0, libc6, libcupsys2, libfontconfig1, libfreetype6, libgcc1, libgconf2-4, libgtk2.0-0, libglib2.0-0, libgnome2-0, libgnomecanvas2-0, libgnome-desktop-2 | libgnome-desktop-2-7 | libgnome-desktop-2-11 | libgnome-desktop-2-17 | libgnome-desktop-3-2, libgnomeui-0, libgnomevfs2-0, libglib2.0-0, libice6, libjpeg62, liborbit2, libpam0g, libpango1.0-0, libpng12-0, libpopt0, libsm6, libstdc++6, libx11-6, libxcursor1, libxext6, libxft2, libxi6, libxkbfile1, libxml2, libxp6, libxrender1, libxss1, libxt6, libxtst6, libz1
   
10. Save your changes and close the text editor.
    
11. Open a terminal and change to the root of your working directory where you have the “ibm-notes-9.0.i586″ directory, but don’t actually go into it.
    
12. Now let’s repackage a new deb file from our modified data using the following command:
    
    $ dpkg-deb -b ibm-notes-9.0.i586
    
    …and hit Enter. You will see the following message and the repackage process will take about 30-60 seconds:
    
    dpkg-deb: building package `ibm-notes:i386' in `ibm-notes-9.0.i586.deb'.
    
13. Once the new package has completed building, you will have a new “ibm-notes-9.0.i586.deb” file, ready for installing onto a 64-bit system.

Installing everything on a 64-bit system

1. First we need to install the 32-bit dependencies manually. In a terminal, type in the following and hit Enter:
   
   $ sudo apt-get update; sudo apt-get install ia32-libs libgnomeprint2.2-0:i386 libgnomeprintui2.2-0:i386 libbonobo2-0:i386 libbonoboui2-0:i386 libgconf2-4:i386 libgnome-desktop-2-17:i386 libgnomevfs2-bin:i386 libgnomeui-0:i386 libjpeg62:i386 libpam0g:i386 libxkbfile1:i386 ttf-xfree86-nonfree t1-xfree86-nonfree -y
   
2. Now type in the following and hit Enter (yes, we have technically already installed this but for some reason it doesn’t configure itself until we install it again):
   
   $ sudo apt-get install libgnomeprintui2.2-0:i386 -y
   
3. Now we can start installing the Notes debs in order:
   
   $ sudo dpkg -i ibm-notes-9.0.i586.deb
$ sudo dpkg -i ibm-cae-9.0.i586.deb
$ sudo dpkg -i ibm-connections-4.5.0.i586.deb
$ sudo dpkg -i ibm-activities-9.0.i586.deb
$ sudo dpkg -i ibm-sametime-9.0.i586.deb
$ sudo dpkg -i ibm-opensocial-9.0.i586.deb
   
4. If there were no error messages, IBM Notes 9.0 is now successfully installed and you can now launch it from the Unity Dash (in Ubuntu) and manually add the icon to your Unity launcher.
   
5. Pat yourself on the back. You are done.

So, you’ve procured a number of files that represent a pre-recorded television series and they are typically named something like this:

MyTVShow.Original.S01E01-720p.HDTV.x264-ImAwesome.mkv
MyTVShow.Original.S01E02-720p.HDTV.x264-ImAwesome.mkv
MyTVShow.Original.S01E03-720p.HDTV.x264-ImAwesome.mkv
MyTVShow.Original.S01E04-720p.HDTV.x264-ImAwesome.mkv

You’d like to rename them to look something like this instead:

MyTVShow S01E01.mkv
MyTVShow S01E02.mkv
MyTVShow S01E03.mkv
MyTVShow S01E04.mkv

Normally you’d tediously edit each filename and rename them manually, but to do so individually across a large folder will take a long time. Surely there’s a way to rename them all in a more convenient manner?

There certainly is! And with just one command too…

One command? How can you possibly do that, you ask? Well, Linux commands generally have the ability to accept a regular or Perl expression to allow for complex matching tasks, simplifying your work, and we will utilise that here with the rename command’s ability to parse Perl expressions.

Note: As I understand it, only Debian-based distros such as Ubuntu carry the “rename” command as part of the default command set. Other distros may require you to add the command binary to your system.

The task in this case is to take a string to match on, in this case “MyTVShow.Original.”, take a wildcard match of the “SxxEyy” part (where “xx” and “yy” are any numeric characters), ignore everything after that and then create a new string for the filename that is formatted as “MyTVShow SxxEyy.mkv” and replace “xx” and “yy” with the Season and Episode number picked up in the wildcard match.

And even better than that, we will write this in such a way that we can support any file extension so it doesn’t matter if the folder contains “.mkv” or “.avi” or “.mp4″ files, they will all be preserved in the rename.

This is the command you need:

rename -n 's/MyTVShow\.Original\.[Ss](\d{2})[Ee](\d{2}).+(\.\D{3})/MyTVShow\ S$1E$2$3/' *

When you run it, you will see output as follows:

$ rename -n 's/MyTVShow\.Original\.[Ss](\d{2})[Ee](\d{2}).+(\.\D{3})/MyTVShow\ S$1E$2$3/' *
MyTVShow.Original.S01E01-720p.HDTV.x264-ImAwesome.mkv renamed as MyTVShow S01E01.mkv
MyTVShow.Original.S01E02-720p.HDTV.x264-ImAwesome.mkv renamed as MyTVShow S01E02.mkv
MyTVShow.Original.S01E03-720p.HDTV.x264-ImAwesome.mkv renamed as MyTVShow S01E03.mkv
MyTVShow.Original.S01E04-720p.HDTV.x264-ImAwesome.mkv renamed as MyTVShow S01E04.mkv

But hang on, when I list my files, they’ve still got the old names! What gives?

The “-n” parameter tells the rename command not to actually action any rename, but show you what it would have acted on – good for testing just in case you made a mistake in your match criteria. Once you are ready to commit the rename, either remove the “-n” parameter or if you’d like to see what the rename command is doing, replace it with “-v” for verbose output instead (it’s the same as “-n”‘s output).

So exactly how does this command work? Let’s break it down a bit:

rename -n ‘s/MyTVShow\.Original\.[Ss](\d{2})[Ee](\d{2}).+(\.\D{3})/MyTVShow\ S$1E$2$3/’ *

• The first part specifies the rename command, the parameters to use and specifies the starting string we need to match on. You will notice that there are backslashes before the full stops. This is needed because the full stop character has other functions in an expression and so to specify it as a literal character, we need to “escape” out of the expression mode into “literal” mode, and that is facilitated by the blackslash. The character that follows the backslash is to be taken literally as part of the string we are constructing. If you wanted to literally specify a backslash character, for example, you’d have to specify a double backslash, ie: “\\”.

rename -n ‘s/MyTVShow\.Original\.[Ss](\d{2})[Ee](\d{2}).+(\.\D{3})/MyTVShow\ S$1E$2$3/’ *

• This part matches the “SxxEyy” part of the filename. This is not a literal string in this case because we need to dynamically cater for the different Season and Episode numbers in each filename. In addition to that, Linux filenames are case-sensitive, so we also need to consider that the “S” and “E” parts could be upper or lowercase, so we start with “[Ss]” which means “match either a capital ‘S’ or a lowercase ‘s’ please”, then we specify that we wish to wildcard the next two digits by specifying “(\d{2})”. The “\d” means to match any numerical digit and is essentially a shorthand version of “[0-9]” (it also matches other language numerical digits beyond the English 0-9, but I digress). The “{2}” part means apply that digit match to the next two characters, so we match on “01” or “02” or “03”, etc.We apply the same process to the “Eyy” part of the string, again matching either a capital “E” or a lowercase “e” followed by any two numerical digits.Finally, we accept the remainder of the filename up to the filename extension with the “.” part (because we don’t care what’s here) and explicitly wildcard match the extension with the “+(\.\D{3})” part, which allows us to match any three character file extension (not just numbers), for example “.mkv”, “.MKV”, “.avi”, “.mpg”, etc, however it will NOT match “.mpeg” or “.jpeg” or “.myfilextension” because those are larger than three character extensions that while they form a part of perfectly legal filenames, they are also very uncommon. In this case we will ignore them and assume that we’ll only ever deal with three character file extensions.

rename -n ‘s/MyTVShow\.Original\.[Ss](\d{2})[Ee](\d{2}).+(\.\D{3})/MyTVShow\ S$1E$2$3/’ *

• Now that we’ve specified our matching criteria, what do we do when we’ve found that match? We need to tell the rename command what we’re going to be renaming it to. The first forward slash means we’ve finished specifying our match criteria and are now specifying our rename string and it starts off with “MyTVShow” followed by an escape to be able to specify a space before the “SxxEyy” bit. We then specify the “SxxEyy” bit as “S$1E$2″.Now you didn’t know this, but in the previous matching criteria, the digit wildcard matches were automatically stored as variables because they were surrounded by parenthesis “(” and “”. Variables generated start at $1 and continue up as $2, $3, etc. You can now specify those variables as part of your destination filename and in this case, the Season number that was wildcard matched from the original filename is now specified as the first variable $1 in your destination filename, thus if “03” was in the original filename as the Season number, you can now write “03” as part of your destination filename. Ditto the Episode number as variable $2.Finally, we end the destination string with a straight up “$3″ that will specify the third variable we created which is the filename extension picked up in the wildcard match, which in our tutorial example will be “.mkv”. The beauty of this is that if you had multiple files with different file extensions, those extensions will be completely preserved.

rename -n ‘s/MyTVShow\.Original\.[Ss](\d{2})[Ee](\d{2}).+(\.\D{3})/MyTVShow\ S$1E$2$3/’ *

• And finally, we specify which files the rename command will be applied to as a whole. In this case because we have an expression to do the matching, we don’t need to use traditional filename matching, so we just specify an asterisk to apply to “all files” because any file that does not match the search expression will be ignored.

Optional: Getting slightly trickier, but for good reason…

Let’s say you deal with a lot of these files that you have to rename with different names on a regular basis. While the above tutorial has saved you a fair bit of time, at the moment you’re always having to copy and paste the command down and then modifying it to suit the filename strings you are changing from and to, remembering to escape certain characters so that they are processed properly like the full stops. We can make this process even more convenient by using a Bash script to allow us to simply specify a command followed by old and new strings only and not have to worry about escape characters.

1. Create a new file using your text editor (you can name it anything you like and it does not have to have “.sh” on the end):
   
   $ sudo nano /usr/bin/fixfilenames.sh
   
2. Type or copy and paste in the following:
   
   #!/bin/bash
# =============================================================
# Bulk rename TV series files. Written by HyRax, January 2014
# ==============================================================
if [ $# == 0 ]; then
echo ""
echo "Usage: $0 OLDNAME NEWNAME"
echo ""
echo " Eg: If the original filename is 'MyTVShow.Original.S01E01-720p.HDTV.ImAwesome.mkv' then"
echo " specify the command as '$0 MyTVShow.Original. MyTVShow' which will rename"
echo " all the files into 'MyTVShow SxxEyy.mkv' format. Note that a space is assumed as wanted between"
echo " the new name and the SxxEyy part. The Season and Episode numbers along with the file extensions"
echo " will be preserved in each rename."
echo ""
exit
fi

cmd="rename -v 's/$1[Ss](\d{2})[Ee](\d{2}).+(\.\D{3})/$2 S\$1E\$2\$3/' *"
echo ""
echo "Renaming files... (Renamed files will be listed below. Nothing listed means nothing actioned!)"
eval $cmd
echo "Done."
   
3. Save your changes by pressing CTRL+X, then Y and then Enter.
   
4. Now let’s make the new script executable:
   
   $ sudo chmod +x /usr/bin/fixfilenames.sh
   
5. Now you can rename your files as follows (using the tutorial’s filename example):
   
   $ fixfilenames.sh MyTVShow.Original. MyTVShow
   
6. List your directory and you will see all your files renamed successfully!

Pat yourself on the back. You’re done. If you’d like to explore more about expressions and what they can do, there are dozens of general tutorials around on the web which will easily teach you how to modify your expression to cover even more complex matches should you have that need.