Technology Tales

Removing advertisements from uTorrent

BitTorrent may have got some bad press due to its use for downloading copyrighted material such as music and movies but it does have its legitimate uses too. In my case, many a Linux distro has been downloaded in this way and it does take the weight off servers by distributing the load across users instead.

Speaking of Linux, my general choice of client has been Transmission and there are others. In the Windows world, there is a selection that includes BitTorrent, Inc. themselves. However, many favour uTorrent (or μTorrent) so that’s the one that I tried and there free and subscription-based options. To me, the latter feels like overkill when an eternal licence could be made available as an easy way to dispatch the advertisements on display in the free version.

As much as I appreciate the need for ads to provide revenue to a provider of otherwise free software, they do need to be tasteful and those in uTorrent often were for dating websites that had no scruples about exposing folk to images that were unsuitable for a work setting. Those for gaming websites were more tolerable in comparison. With the non-availability of an eternal licence option, I was left pondering alternatives like qBittorrent instead. That is Free Software too so it does have that added advantage.

However, I uncovered an article on LifeHacker that sorted my problem with uTorrent. The trick is to go into Options > Preferences via the menus and then go to the Advanced section in the dialogue box that appears. In there, go looking for each of the following options and set each one to false in turn:

• offers.left_rail_offer_enabled/left_rail_offer
• gui.show_plus_upsell
• offers.sponsored_torrent_offer_enabled/sponsored_torrent_offer_enabled
• bt.enable_pulse
• gui.show_notorrents_node
• offers.content_offer_autoexec

In practice, I found some of the above already set to false and another missing but set those that remained from true to false cleaned up the interface so I hope never to glimpse those unsuitable ads again. The maker of uTorrent need to look at the issue or revenue could get lost and prospective users could see the operation as being cheapened by what is displayed. As for me, I am happy to have gained something in the way of control.

Fixing Background Image Display in GNOME Shell 3.10

On upgrading from Ubuntu GNOME 13.10 to Ubuntu GNOME 14.04, a few rough edges were to be noticed. One was the display of my chosen background image: it was garbled. Later, I discovered that there is a maximum width of 2560 px for background images in GNOME Shell these days and that things get messy beyond that.

In my case, the image width was around 6000 px and I was used to its getting resized in GNOME Shell 3.8 and its predecessors. It seems that the functionality got removed after that though so the workaround of manual image resizing in the GIMP needed to be employed. Though having big images open in memory creates an additional overhead, not handling them very well at all looks like a bug caused by setting 2560 px as a maximum screen width for the GNOME Shell panel and the complete removal of Nautilus from desktop rendering duties. Let’s hope that sense is seen with ever larger screen sizes and resolutions coming our way.

It’s the sort of thing that did get me looking at adding on Cinnamon 2.2 for a while before setting background image scaling using the indispensable GNOME Tweak Tool was discovered. LinuxG.net has a useful tutorial on this for anyone with such an adventurous streak in them. For now though, I am OK with my set up but the GNOME project’s focus on minimalism could affect us in other ways so I can see why Clem Lefebvre started the Cinnamon one primarily for Linux Mint and the desktop environment is appearing elsewhere too. After all, Gedit lost its menu bar in GNOME 3.12 so it’s just as well that we have alternative choices.

Update 2014-05-06: It seems that the desktop image bug that afflicts GNOME Shell 3.10 got sorted for GNOME Shell 3.12. At least, that is the impression that an Antergos instance in a VirtualBox virtual machine gives me.

Turning off seccomp sandbox in vsftpd

Within the last week, I set up virtual web server using Arch Linux to satisfy my own curiosity since the DIY nature of Arch means that you can build up exactly what you need without having any real constraints put upon you. What didn’t surprise me about this was that it took me more work than the virtual server that I created using Ubuntu Server but I didn’t expect ProFTPD to be missing from the main repositories. The package can be found in the AUR but I didn’t fancy the prospect of dragging more work on myself so I went with vsftpd (Very Secure FTP Daemon) instead. In contrast to ProFTPD, this is available in the standard repositories and there is a guide to its use in the Arch user documentation.

However, while vsftpd worked well just after installation, connections to the virtual FTP soon failed with FileZilla  began issuing uninformative messages. In fact, it was the standard command line FTP client on my Ubuntu machine that was more revealing. It issued the following message that let me to the cause after my engaging the services of Google:

500 OOPS: priv_sock_get_cmd

With version 3.0 of vsftpd, a new feature was introduced and it appears that this has caused problems for a few people. That feature is seccomp sandboxing and it can turned off by adding the following line in /etc/vsftpd.conf:

seccomp_sandbox=NO

That solved my problem and version 3.0.2 of vsftpd should address the issue with seccomp sandboxing anyway. In case, this solution isn’t as robust as it should be because seccomp isn’t supported in the Linux kernel that you are using, turning off the new feature still needs to be an option though.

Command Line Processing of EXIF Image Metadata

There is a bill making its way through the U.K. parliament at the moment that could reduce the power of copyright when it comes to images placed on the web. The current situation is that anyone who creates an image automatically holds the copyright for it. However, the new legislation will remove that if it becomes law as it stands. As it happens, the Royal Photographic Society is doing what it can to avoid any changes to what we have now. There may be the barrier of due diligence but how many of us take steps to mark our own intellectual property? For one, I have been less that attentive to this and now wonder if there is anything more that I should be doing. Others may copyleft their images but I don’t want to find myself unable to share my own photos because another party is claiming rights over them. There’s watermarking them but I also want to add something to the image metadata too.

That got me wondering about adding metadata to any images that I post online that assert my status as the copyright holder. It may not be perfect but any action is better than doing nothing at all. Given that I don’t post photos where EXIF metadata is stripped as part of the uploading process, it should be there to see for anyone who bothers to check and there may not be many who do.

Because I also wanted to batch process images, I looked for a command line tool to do the needful and found ExifTool. Being a Perl library, it is cross-platform so you can use it on Linux, Windows and even OS X. To install it on a Debian or Ubuntu based Linux distro, just use the following command:

sudo apt-get install libimage-exiftool-perl

The form of the command that I found useful for adding the actual copyright information is below:

exiftool -p “-copyright=(c) John …” -ext jpg -overwrite_original

The -p switch preserves the timestamp of the image file while the -overwrite_original one ensures that you don’t end up with unwanted backup files. The copyright message goes within the quotes along with the -copyright option. With a little shell scripting, you can traverse a directory structure and change the metadata for any image files contained in different sub-folders. If you wish to do more than this, there’s always the user documentation to be consulted.

Setting up MySQL on Sabayon Linux

For quite a while now, I have offline web servers for doing a spot of tweaking and tinkering away from the gaze of web users that visit what I have on there. Therefore, one of the tests that I apply to any prospective main Linux distro is the ability to set up a web server on there. This is more straightforward for some than for others. For Ubuntu and Linux Mint, it is a matter of installing the required software and doing a small bit of configuration. My experience with Sabayon is that it needs a little more effort than this and I am sharing it here for the installation of MySQL.

The first step is too install the software using the commands that you find below. The first pops the software onto the system while second completes the set up. The --basedir option is need with the latter because it won’t find things without it. It specifies the base location on the system and it’s /usr in my case.

sudo equo install dev-db/mysql
sudo /usr/bin/mysql_install_db --basedir=/usr

With the above complete, it’s time to start the database server and set the password for the root user. That’s what the two following commands achieve. Once your root password is set, you can go about creating databases and adding other users using the MySQL command line

sudo /etc/init.d/mysql start
mysqladmin -u root password ‘password’

The last step is to set the database server to start every time you start your Sabayon system. The first command adds an entry for MySQL to the default run level so that this happens. The purpose of the second command is check that this happened before restarting your computer to discover if it really happens. This procedure also is needed for having an Apache web server behave in the same way so the commands are worth having and even may have a use for other services on your system. ProFTP is another that comes to mind, for instance.

sudo rc-update add mysql default
sudo rc-update show | grep mysql

Renaming multiple files in Linux

The Linux and UNIX command mv has a number of limitations, such as not overwriting destination files and not renaming multiple files using wildcards. The only solution to the first that I can find is one that involves combining the cp and rm commands. For the second, there’s another command: rename. There is a command like it in Windows but this one is a little different in its syntax. Before saying more about that, here’s an example like what I used recently:

rename s/fedora/fedora2/ fedora.*

The first argument in the above command is a regular expression much like what Perl is famous for implementing; in fact, it is Perl-compatible ones (PCRE) that are used. The s before the first slash stands for substitute with fedora being the string that needs to be replaced and fedora being what replaces it. The third command is the file name glob that you want to use, fedora.* in this case. Therefore, all files in a directory named fedora will be renamed fedora2 regardless of the file type. The same sort of operation can be performed for all files with the same extension and it needing changing, htm to html, for instance. Of course, there are other uses but these are handy ones to know.

Sorting out MySQL on Arch Linux

Seeing Arch Linux running so solidly in a VirtualBox virtual box has me contemplating whether I should have it installed on a real PC. Saying that, recent announcements regarding the implementation of GNOME 3 in Linux Mint have caught my interest even if the idea of using a rolling distribution as my main home operating system still has a lot of appeal for me. Having an upheaval come my way every six months when a new version of Linux Mint is released is the main cause of that.

While remaining undecided, I continue to evaluate the idea of Arch Linux acting as my main OS for day-to-day home computing. Towards that end, I have set up a working web server instance on there using the usual combination of Apache, Perl, PHP and MySQL. Of these, it was MySQL that went the least smoothly of all because the daemon wouldn’t start for me.

It was then that I started to turn to Google for inspiration and a range of actions resulted that combined to give the result that I wanted. One problem was a lack of disk space caused by months of software upgrades. Since tools like it in other Linux distros allow you to clear some disk space of obsolete installation files, I decided to see if it was possible to do the same with pacman, the Arch Linux command line package manager. The following command, executed as root, cleared about 2 GB of cruft for me:

pacman -Sc

The S in the switch tells pacman to perform package database synchronization while the c instructs it to clear its cache of obsolete packages. In fact, using the following command as root every time an update is performed both updates software and removes redundant or outmoded packages:

pacman -Syuc

So I don’t forget the needful housekeeping, this will be what I use in future with the y being the switch for a refresh and the u triggering a system upgrade. It’s nice to have everything happen together without too much effort.

To do the required debugging that led me to the above along with other things, I issued the following command:

mysqld_safe --datadir=/var/lib/mysql/ &

This starts up the MySQL daemon in safe mode if all is working properly and it wasn’t in my case. Nevertheless, it creates a useful log file called myhost.err in /var/lib/mysql/. This gave me the messages that allowed the debugging of what was happening. It led me to installing net-tools and inettools using pacman; it was the latter of these that put hostname on my system and got the MySQL server startup a little further along. Other actions included unlocking the ibdata1 data file and removing the ib_logfile0 and ib_logfile1 files so as to gain something of a clean sheet. The kill command was used to shut down any lingering mysqld sessions too. To ensure that the ibdata1 file was unlocked, I executed the following commands:

mv ibdata1 ibdata1.bad
cp -a ibdata1.bad ibdata1

These renamed the original and then crated a new duplicate of it with the -a switch on the cp command forcing copying with greater integrity than normal. Along with the various file operations, I also created a link to my.cnf, the MySQL configuration file on Linux systems, in /etc using the following command executed by root:

ln -s /etc/mysql/ my.cnf /etc/my.cnf

While I am unsure if this made a real difference, uncommenting the lines in the same file that pertained to InnoDB tables. What directed me to these were complaints from mysqld_safe in the myhost.err log file. All I did was to uncomment the lines beginning with “innodb” and these were 116-118, 121-122 and 124-127 in my configuration file but it may be different in yours.

After all the above, the MySQL daemon ran happily and, more importantly, started when I rebooted the virtual machine. Thinking about it now, I believe that was a lack of disk space, the locking of a data file and the lack of InnoDB support that was stopping the MySQL service from running.Running commands like mysqld start weren’t yielding useful messages so a lot of digging was needed to get the result that I needed. In fact, that’s one of the reasons why I am sharing my experiences here.

In the end, creating databases and loading them with data was all that was needed for me to start see functioning websites on my (virtual) Arch Linux system. It turned out to be another step on the way to making it workable as a potential replacement for the Linux distributions that I use most often (Linux Mint, Fedora and Ubuntu).

All Change?

Could 2011 be remembered as the year when the desktop computing interface got a major overhaul? One part of this, Windows 8, won’t be with us until next year but there has been enough happening so far this year that has resulted in a lot of comment. With many if not all of the changes, it is possible to detect the influence of interfaces used on smartphones. After all, the carryover from Windows Phone 7 to the new Metro interface is unmistakeable.

Two developments in the Linux world have spawned a hell of an amount of comment: Canonical’s decision to develop Unity for Ubuntu and the arrival of GNOME 3. While there have been many complaints about the changes made in both, there must be a fair few folk who are just getting on with using them without complaint. Maybe there are many who even quietly like the new interfaces. While I am not so sure about Unity, I surprised myself by taking to GNOME Shell so much that I installed it on Linux Mint. It remains a work in progress as does Unity but it’ll be very interesting to see it mature. Perhaps a good number of the growing collection of GNOME Shell plugins could make it into the main codebase. If that were to happen, I could see it being welcomed by a good few folk.

There was little doubt that the changes in GNOME 3 looked daunting so Ubuntu’s taking a different approach is understandable until you come to realise how change that involves anyway. With GNOME 3 working so well for me, I feel disinclined to dally very much with Unity at all. In fact, I am writing these words on a Toshiba laptop running UGR, effectively Ubuntu running GNOME 3, and that could become my main home computing operating system in time.

For those who find these changes not to their taste, there are alternatives. Some Linux distributions are sticking with GNOME 2 as long as they can and there apparently has been some mention of a fork to keep a GNOME 2 interface available indefinitely. However, there are other possibilities such as LXDE and XFCE out there too. In fact, until GNOME 3 won me over, LXDE was coming to mind as a place of safety until I learned that Linux Mint was retaining its desktop identity. As always, there’s KDE too but I have never warmed to that for some reason.

The latest version of OS X, Lion, also included some changes inspired by iOS, the operating system that powers both the iPhone and iPad. However, while the current edition of PC Pro highlights some disgruntlement in professional circles regarding Apple’s direction, they do not seem to have aroused the kind of ire that has been abroad in the world of Linux. Is it because Linux users want to feel that they are in charge and that iMac and MacBook users are content to have decisions made for them so long as everything just works? Speaking for myself, the former description seems to fit me though having choices means that I can reject decisions that I do not like so much.

At the time of writing, the release of a developer preview of the next version of Windows has been generating a lot of attention. It also appears that changes are headed for the Windows user too. However, I get the sense that a more conservative interface option will be retained and that could be essential for avoiding the alienation of corporate users. After all, I cannot see the Metro interface gaining much favour in the working environment when so many of us have so much to do. Nevertheless, I plan to get my hands on the developer preview to have a look (the weekend proved too short for this). It will be very interesting to see how the next version of Windows develops and I plan to keep an eye on it as it does so.

It now looks as if many will have their work cut out if they are to avoid where desktop computing interfaces are going. Established paradigms are being questioned, particularly as a result of touch interfaces on smartphones and tablets. Wii and Kinect have involved other ways of interacting with computers too so there’s a lot of mileage in rethinking how we work with computers. So far, I have been able to deal with the changes in the world of Linux but I am left wondering at the changes that Microsoft is making. After Vista, they need to be careful and they know that. Maybe, they’ll be better at getting users through changes in computing interfaces than others but it’ll be very interesting to see what happens. Unlike open source community projects, they have the survival of a massive multinational at stake.

Adding GNOME 3 to Linux Mint 11

On the surface of it, this probably sounds a very strange thing to do: choose Linux Mint because they plan to stick with their current desktop interface for the foreseeable future and then stick a brand new one on there. However, that’s what last weekend’s dalliance with Fedora 15 caused. Not only did I find that I could find my way around GNOME Shell but I actually got to like it so much that I missed it on returning to using my Linux Mint machine again.

The result was that I started to look on the web to see if there was anyone else like me who had got the same brainwave. In fact, it was Mint’s being based on Ubuntu that allowed me to get GNOME 3 on there. The task could be summarised as involving three main stages: getting GNOME 3 installed, adding extensions and adding the Cantarell font that is used by default. After these steps, I gained a well-running GNOME 3 desktop running on Linux Mint and it looks set to stay that way unless something untoward has yet to emerge.

Installing GNOME 3

The first step is to add the PPA repository for GNOME 3 using the following command:

sudo add-apt-repository ppa:gnome3-team/gnome3

The, it was a case of issuing my usual update/upgrade command:

sudo apt-get update && sudo apt-get upgrade && sudo apt-get dist-upgrade

When that had done its thing and downloaded and installed quite a few upgrades along the way, it was time to add GNOME Shell using this command:

sudo apt-get install gnome-shell

When that was done, I rebooted my system to be greeted by a login screen very reminiscent of what I had seen in Fedora. While compiling this piece, I noticed that GNOME Session could need to be added before GNOME Shell but I do not recall doing so myself. Maybe dependency resolution kept any problems at bay, but there weren’t any issues that I could remember beyond things not being configured as fully as I would have liked without further work. For the sake of safety, it might be a good idea to run the following before adding GNOME Shell to your PC.

sudo apt-get install gnome-session && sudo apt-get dist-upgrade

Configuration and Customisation

Once I had logged in, the desktop that I saw wasn’t at all unlike the Fedora one and everything seemed stable too. However, there was still work to do before I was truly at home with it. One thing that was needed was the ever useful GNOME Tweak Tool. This came in very handy for changing the theme that was on display to the standard Adwaita one that caught my eye while I was using Fedora 15. Adding buttons to application title bars for minimising and maximising their windows was another job that the tool allowed me to do. The command to get this goodness added in the first place is this:

sudo apt-get install gnome-tweak-tool

The next thing that I wanted to do was add some extensions so I added a repository from which to do this using the command below. Downloading them via Git and compiling them just wasn’t working for me so I needed another approach.

sudo add-apt-repository ppa:ricotz/testing

With that is place, I issued the following commands to gain the Dock, the Alternative Status Menu and the Windows Navigator. The second of these would have added a shutdown option in the me-menu but it seems to have got deactivated after a system update. Holding down the ALT key to change the Suspend entry to Power off… will have to do me for now. Having the dock is the most important and that, thankfully, is staying the course and works exactly as it does for Fedora.

sudo apt-get install gnome-shell-extensions-dock
sudo apt-get install gnome-shell-extensions-alternative-status-menu
sudo apt-get install gnome-shell-extensions-windows-navigator

Adding Cantarell

The default font used by GNOME 3 in various parts of its interface is Cantarell and it was defaulting to that standard sans-serif font on my system because this wasn’t in place. That font didn’t look too well so I set to tracking the freely available Cantarell down on the web.  When that search brought me to Font Squirrel, I downloaded the zip file containing the required TTF files. The next step was to install them and, towards that end, I added Fontmatrix using this command:

sudo apt-get install fontmatrix

That gave me a tool with a nice user interface but I made a mistake when using it. This was because I (wrongly) thought that it would copy files from the folder that I told the import function to use. Extracting the TTF files to /tmp meant that would have had to happen, but Fontmatrix just registered them instead. A reboot confirmed that they hadn’t been copied or moved at all and I had rendered the user interface next to unusable through my own folly; the default action on Ubuntu and Linux Mint is that files are deleted from /tmp on shutdown. The font selection capabilities of the GNOME Tweak Tool came in very handy for helping me to convert useless boxes into letters that I could read.

Another step was to change the font line near the top of the GNOME Shell stylesheet (never thought that CSS usage would end up in places like this…) so that Cantarell wasn’t being sought and text in sans-serif font replaced grey and white boxes. The stylesheet needs to be edited as superuser, so the following command is what’s needed for this and, while I used sudo, gksu is just as useful here if it isn’t what I should have been using.

sudo gedit /usr/share/gnome-shell/theme/gnome-shell.css

Once I had extricated my system from that mess, a more conventional approach was taken and the command sequence below was what I followed, with extensive use of sudo to get done what I wanted. A new directory was created and the TTF files copied in there.

cd /usr/share/fonts/truetype
sudo mkdir ttf-cantarell
cd ttf-cantarell
sudo mv /tmp/*.ttf .

To refresh the font cache, I resorted to the command described in a tutorial in the Ubuntu Wiki:

sudo fc-cache -f -v

Once that was done, it was then time to restore the reference to Cantarell in the GNOME Shell stylesheet and reinstate its usage in application windows using the GNOME Tweak Tool. Since then, I have suffered no mishap or system issue with GNOME 3. Everything seems to be working quietly and I am happy to see that replacement of Unity with the GNOME Shell will become an easier task in Ubuntu 11.10, the first alpha release of which is out at the time of my writing these words. Could it lure me back from my modified instance of Linux Mint yet? While I cannot say that I am sure of those but it certainly cannot be ruled out at this stage.

On Upgrading to Linux Mint 11

For a Linux distribution that focuses on user-friendliness, it does surprise me that Linux Mint offers no seamless upgrade path. In fact, the underlying philosophy is that upgrading an operating system is a risky business. However, I have been doing in-situ upgrades with both Ubuntu and Fedora for a few years without any real calamities. A mishap with a hard drive that resulted in lost data in the days when I mainly was a Windows user places this into sharp relief. These days, I am far more careful but thought nothing of sticking a Fedora DVD into a drive to move my Fedora machine from 14 to 15 recently. Apart from a few rough edges and the need to get used to GNOME 3 together with making a better fit for me, there was no problem to report. The same sort of outcome used to apply to those online Ubuntu upgrades that I was accustomed to doing.

The recommended approach for Linux Mint is to back up your package lists and your data before the upgrade. Doing the former is a boon because it automates adding the extras that a standard CD or DVD installation doesn’t do. While I did do a little backing up of data, it wasn’t total because I know how to identify my drives and take my time over things. Apache settings and the contents of MySQL databases were my main concern because of where these are stored.

When I was ready to do so, I popped a DVD in the drive and carried out a fresh installation into the partition where my operating system files are kept. Being a Live DVD, I was able to set up any drive and partition mappings with reference to Mint’s Disk Utility. What didn’t go so well was the GRUB installation, and it was due to the choice that I made on one of the installation screens. Despite doing an installation of version 10 just over a month ago, I had overlooked an intricacy of the task and placed GRUB on the operating system files partition rather than at the top level for the disk where it is located. Instead of trying to address this manually, I took the easier and more time-consuming step of repeating the installation like I did the last time. If there was a graphical tool for addressing GRUB problems, I might have gone for that instead, but am left wondering at why there isn’t one included at all. Maybe it’s something that the people behind GRUB should consider creating unless there is one out there already about which I know nothing.

With the booting problem sorted, I tried logging in only to find a problem with my desktop that made the system next to unusable. It was back to the DVD and I moved many of the configuration files and folders (the ones with names beginning with a “.”) from my home directory in the belief that there might have been an incompatibility. That action gained me a fully usable desktop environment but I now think that the cause of my problem may have been different to what I initially suspected. Later I discovered that ownership of files in my home area elsewhere wasn’t associated with my user ID though there was no change to it during the installation. As it happened, a few minutes with the chown command were enough to sort out the permissions issue.

The restoration of the extra software that I had added beyond what standardly gets installed was took its share of time but the use of a previously prepared list made things so much easier. That it didn’t work smoothly because some packages couldn’t be found the first time around, so another one was needed. Nevertheless, that is nothing compared to the effort needed to do the same thing by issuing an installation command at a time. Once the usual distribution software updates were in place, all that was left was to update VirtualBox to the latest version, install a Citrix client and add a PHP plugin to NetBeans. Then, next to everything was in place for me.

Next, Apache settings were restored as were the databases that I used for offline web development. That nearly was all that was needed to get offline websites working but for the need to add an alias for localhost.localdomain. That required installation of the Network Settings tool so that I could add the alias in its Hosts tab. With that out of the way, the system had been settled in and was ready for real work.

In light of some of the glitches that I saw, I can understand the level of caution regarding a more automated upgrade process on the part of the Linux Mint team. Even so, I still wonder if the more manual alternative that they have pursued brings its own problems in the form of those that I met. The fact that the whole process took a few hours in comparison to the single hour taken by the in-situ upgrades that I mentioned earlier is another consideration that makes you wonder if it is all worth it every six months or so. Saying that, there is something to letting a user decide when to upgrade rather than luring one along to a new version, a point that is more than pertinent in light of the recent changes made to Ubuntu and Fedora. Whichever approach you care to choose, there are arguments in favour as well as counterarguments too.