Adventures & experiences in contemporary technology
When I recently did my usual system update for the stable version Ubuntu GNOME, there were some updates pertaining to apt and the process failed when I executed the following command:
sudo apt-get upgrade
Usefully, some messages were issued and here’s a flavour:
Setting up apt (0.9.9.1~ubuntu3.1) …
ERROR: Can’t find the archive-keyring
Is the ubuntu-keyring package installed?
dpkg: error processing apt (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
apt
E: Sub-process /usr/bin/dpkg returned an error code (1)
Some searching on the web revealed that the problem was that there were no files in /usr/share/keyring when there should have been and I had not removed them myself so I have no idea how they disappeared. Various remedies were tried and any that needed software installed were non-starters because apt was disabled by the lack of keyring files. The workaround that restored things for me was to take a copy of the files in /usr/share/keyring from an Ubuntu GNOME 14.04 installation in a VirtualBox VM and copy them in to the same location in its Ubuntu GNOME 13.10 host. For those without such resources, I have packaged them in a zip file below. Other remedies like Y PPA also were suggested where I was reading but that software package needed installing beforehand so it was little use to me when the likes of Synaptic were disabled. If there are other remedies that do not involve an operating system re-installation, I would like to know about them too as well as possible causes for the file loss in the first place and how to avoid these.
When I upgraded to Ubuntu GNOME 13.10 and went for the 64-bit variant, I tried a previously tried and tested approach for installing Nightingale that used a PPA only for it not to work. At that point, the repository had not caught up with the latest Ubuntu release (it has by the time of writing) and other pre-compiled packages would not work either. However, there was one further possibility left and that was downloading a copy of the source code and compiling that. My previous experiences of doing that kind of thing have not been universally positive so it was not my first choice but I gave it a go anyway.
In order to get the source code, I first needed to install Git so I could take a copy from the version controlled repository and the following command added the tool and all its dependencies:
sudo apt-get install git autoconf g++ libgtk2.0-dev libdbus-glib-1-dev libtag1-dev libgstreamer-plugins-base0.10-dev zip unzip
With that lot installed, it was time to checkout a copy of the latest source code and I went with the following:
git clone https://github.com/nightingale-media-player/nightingale-hacking.git
The next step was to go into the nightingale-hacking sub-folder and issue the following command:
./build.sh
That should produce a sub-directory named nightingale that contains the compiled executable files. If this exists, it can be copied into /opt. If not, then create a folder named nightingale under /opt using copy the files from ~/nightingale-hacking/compiled/dist into that location. Ubuntu GNOME 13.10 comes with GNOME Shell 3.8, the next step took a little fiddling before it was sorted: adding an icon to application menu or dashboard. This involved adding a file called nightingale.desktop in /usr/share/applications/ with the following contents:
[Desktop Entry]
Name=Nightingale
Comment=Play music
TryExec=/opt/nightingale/nightingale
Exec=/opt/nightingale/nightingale
Icon=/usr/share/pixmaps/nightingale.xpm
Type=Application
X-GNOME-DocPath=nightingale/index.html
X-GNOME-Bugzilla-Bugzilla=Nightingale
X-GNOME-Bugzilla-Product=nightingale
X-GNOME-Bugzilla-Component=BugBuddyBugs
X-GNOME-Bugzilla-Version=1.1.2
Categories=GNOME;Audio;Music;Player;AudioVideo;
StartupNotify=true
OnlyShowIn=GNOME;Unity;
Keywords=Run;
Actions=New
X-Ubuntu-Gettext-Domain=nightingale
[Desktop Action New]
Name=Nightingale
Exec=/opt/nightingale/nightingale
OnlyShowIn=Unity
It was created from a copy of another *.desktop file and the categories in there together with the link to the icon were as important as the title and took a little tinkering before all was in place. Also, you may find that /opt/nightingale/chrome/icons/default/default.xpm needs to be become /usr/share/pixmaps/nightingale.xpm using the cp command before your new menu entry gains an icon to go with it. While the steps that I describe here worked for me, there is more information on the Nightingale wiki if you need it.
More than a decade of computer upgrades and rebuilds can leave obsolete kit in your hands and the arrival of legislation controlling the dumping of electronic goods during this time can leave one wondering how anyone can dispose of them. Thankfully, I discovered that the local council refuse site only a few miles away from me accepts such things for recycling and saw me a good few times over the last summer with obsolete and non-working gadgets that has stayed with me far too long. Some were as bulky as a computer monitor and a printer but others were relatively diminutive.
Disposing of non-working and utterly obsolete equipment is an easy choice but I find this is harder when a device still works as intended and even might have a use yet. When you realise that computer motherboards still come with PS/2, floppy and IDE ports, things get trickier. My Gigabyte Z87-HD3 mainboard just has one PS/2 when predecessors would have had two and the same applies to IDE sockets and there still is a floppy drive socket on there too, a surprising sight for anyone used to thinking that such things are utterly outmoded these days. So, PC technology isn’t relinquishing backwards compatibility just yet since that mainboard is part of a system with an Intel Core i5-4670K CPU and 24 GB of RAM on there.
Even with that presence of an IDE port, I was not tempted to use leftover 10 GB and 20GB hard drives that I have had for just over a decade. Ten years ago, that sort of capacity would been respectable were it not for our voracious appetite for data storage thanks to photography, video and music. Apart from the size constraints, the speed of those drives cannot compare well with what we have today either and I quickly saw that when I replaced a Samsung 160 HD of a similar age with a Samsung SSD.
The result of this line of thought was that I was minded to recycle the drives so I started to think about wiping and Linux has a good tool for this in the form of the dd command. It can overwrite data on the disks so as to render the information virtually irretrievable. Also, Linux has a number of dummy devices that can supply junk data for overwriting purposes. They are like /dev/null which is used to suppress the issuing of output to the command. The first is /dev/zero which supplies octal zeros and I have used this. However, there also is /dev/random and /dev/urandom for those wanting a more random element to the overwriting.
To overwrite data on a disk with zeroes while having feedback on progress, the following command achieves the required result:
sudo dd if=/dev/zero | pv | sudo dd of=/dev/sdd bs=16M
The whole operation needs to be executed with root privileges and the if parameter of dd specifies the input data and this is sent to a pv command that shows a progress bar that dd would not produce by itself while sending the output on to another dd command with the disk to be overwritten specified using the of parameter. The bs parameter in that second dd command specifies the block size for the disk writing job. Unfortunately, pv is not installed by default so you need to add it yourself. On a Debian, Ubuntu or Linux Mint system, the command is the following:
sudo apt-get install pv
That pv sandwich also is invaluable for those times when dd is needed to copy partitions between different physical or virtual (in a virtual machine) disks. Without it, you might wonder what exactly is happening in the silence and that especially is concerning when you are retrying an operation that failed previously and it takes a while to complete each time.
The official line from Western Digital is that they do not support the use of their My Book Live NAS drives with Linux or UNIX. However, what that means is that they only develop tools for accessing their products for Windows and maybe OS X. It still doesn’t mean that you cannot access the drive’s configuration settings by pointing your web browser at http://mybooklive.local/. In fact, not having those extra tools is no drawback at all since the drive can be accessed through your file manager of choice under the Network section and the default name is MyBookLive too so you easily can find the thing once it is connected to a router or switch anyway.
Once you are in the servers web configuration area, you can do things like changing its name, updating its firmware, finding out what network has been assigned to it, creating and deleting file shares, password protecting file shares and other things. These are the kinds of things that come in handy if you are going to have a more permanent connection to the NAS from a PC that runs Linux. The steps that I describe have worked on Ubuntu 12.04 and 13.10 with the GNOME desktop environment.
What I was surprised to discover that you cannot just set up a symbolic link that points to a file share. Instead, it needs to be mounted and this can be done from the command line using mount or at start-up with /etc/fstab. For this to happen, you need the Common Internet File System utilities and these are added as follows if you need them (check on the Software Software or in Synaptic):
sudo apt-get install cifs-utils
Once these are added, you can add a line like the following to /etc/fstab:
//[NAS IP address]/[file share name] /[file system mount point] cifs
credentials=[full file location]/.creds,
iocharset=utf8,
sec=ntlm,
gid=1000,
uid=1000,
file_mode=0775,
dir_mode=0775
0 0
Though I have broken it over several lines above, this is one unwrapped line in /etc/fstab with all the fields in square brackets populated for your system and with no brackets around these. Though there are other ways to specify the server, using its IP address is what has given me the most success and this is found under Settings > Network on the web console. Next up is the actual file share name on the NAS and I have used a custom them instead of the default of Public. The NAS file share needs to be mounted to an actual directory in your file system like /media/nas or whatever you like and you will need to create this beforehand. After that, you have to specify the file system and it is cifs instead of more conventional alternatives like ext4 or swap. After this and before the final two space delimited zeroes in the line comes the chunk that deals with the security of the mount point.
What I have done in my case is to have a password protected file share and the user ID and password have been placed in a file in my home area with only the owner having read and write permissions for it (600 in chmod-speak). Preceding the filename with a “.” also affords extra invisibility. That file then is populated with the user ID and password like the following. Of course, the bracketed values have to be replaced with what you have in your case.
username=[NAS file share user ID]
password=[NAS file share password]
With the credentials file created, its options have to be set. First, there is the character set of the file (usually UTF-8 and I got error code 79 when I mistyped this) and the security that is to be applied to the credentials (ntlm in this case). To save having no write access to the mounted file share, the uid and gid for your user needs specification with 1000 being the values for the first non-root user created on a Linux system. After that, it does no harm to set the file and directory permissions because they only can be set at mount time; using chmod, chown and chgrp later on has no effect whatsoever. Here, I have set permissions to read, write and execute for the owner and the user group while only allowing read and execute access for everyone else (that’s 775 in the world of chmod).
All of what I have described here worked for me and had to gleaned from disparate sources like Mount Windows Shares Permanently from the Ubuntu Wiki, another blog entry regarding the permissions settings for a CIFS mount point and an Ubuntu forum posting on mounting CIFS with UTF-8 support. Because of the scattering of information, I just felt that it needed to all together in one place for others to use and I hope that fulfils someone else’s needs in a similar way to mine.
Installing the latest version of Citrix Receiver (13.0 at the time of writing) on 64-bit Ubuntu should be as simple as downloading the required DEB package and double-clicking on the file so that Ubuntu Software Centre can work its magic. Unfortunately, the 64-bit DEB file is faulty so that means that the Ubuntu community how-to guide for Citrix still is needed. In fact, any user of Linux Mint or another distro that uses Ubuntu as its base would do well to have a look at that Ubuntu link.
For sake of completeness, I still am going to let you in on the process that worked for me. Once the DEB file has been downloaded, the first task is to creating a temporary folder where the DEB file’s contents can be extracted:
mkdir ica_temp
With that in place, it then is time to do the extraction and it needs two commands with the second of these need to extract the control file while the first extracts everything else.
sudo dpkg-deb -x icaclient- ica_temp
sudo dpkg-deb --control icaclient- ica_temp/DEBIAN
It is the control file that has been the cause of all the bother because it refers to unavailable dependencies that it really doesn’t need anyway. To open the file for editing, issue the following command:
sudo gedit ica_temp/DEBIAN/control
Then change line 7 (it should begin with Depends:) to: Depends: libc6-i386 (>= 2.7-1), lib32z1, nspluginwrapper. There are other software packages in there that Ubuntu no longer supports and they are not needed anyway. With the edit made and the file saved, the next step is to build a new DEB package with the corrected control file:
dpkg -b ica_temp icaclient-modified.deb
Once you have the package, the next step is to install it using the following command:
sudo dpkg -i icaclient-modified.deb
If it fails, then you have missing dependencies and the following command should sort these before a re-run of the above command again:
sudo apt-get install libmotif4:i386 nspluginwrapper lib32z1 libc6-i386
With Citrix Receiver installed, there is one more thing that is needed before you can use it freely. This is to put Thawte security certificate files into /opt/Citrix/ICAClient/keystore/cacerts. What I had not realised until recently was that many of these already are in /usr/share/ca-certificates/mozilla and linking to them with the following command makes them available to Citrix receiver:
sudo ln -s /usr/share/ca-certificates/mozilla/* /opt/Citrix/ICAClient/keystore/cacerts/
Another approach is to download the Thawte certificates and extract the archive to /tmp/. From there they can be copied to /opt/Citrix/ICAClient/keystore/cacerts and I copied the Thawte Personal Premium certificate as follows:
sudo cp /tmp/Thawte Root Certificates/Thawte Personal Premium CA/Thawte Personal Premium CA.cer /opt/Citrix/ICAClient/keystore/cacerts/
Until I found out about what was in the Mozilla folder, I simply picked out the certificate mentioned in the Citrix error message and copied it over like the above. Of course, all of this may seem like a lot of work to those who are non-tinkerers and I have added a repaired 64-bit DEB package that incorporates all of the above and should not need any further intervention aside from installing it using GDebi, Ubuntu’s Software Centre, dpkg or anything else that does what’s needed.
There is a handy comand line utility called GNU Parallel that allows you to run Linux commands on more than one CPU core at a time to perform parallel processing of the task at hand. Here is a form of the command that is similar to one that I often use:
ls *.* | parallel gm convert -sharpen 1×3 {} sharpened_images/{}
What it does is pipe a list of files in a folder to GraphicsMagick for sharpening and outputting to a sharpened_images directory. The {} in the command is where the filenames go in the sharpening command.
This worked fine in Ubuntu GNOME 12.10 but stopped doing so after I upgraded to the next version. A look on the web set me to running the following command:
parallel --version
That produced output that included the following line:
WARNING: YOU ARE USING --tollef. IF THINGS ARE ACTING WEIRD USE --gnu.
Rerunning the original command with the --gnu option worked but there was a more permanent solution than using something like this:
ls *.* | parallel --gnu gm convert -sharpen 1×3 {} sharpened_images/{}
That was editing /etc/parallel/config with root privileges to delete the --tollef option from there. With that completed, all was as it should again and it makes me wonder why the change was made in the first place. Perhaps because of it, there even is a discussion about the possibility of removing the --tollef option altogether since it is raising more questions than it answers.
One thing that I like to do is peruse the installed applications on any computer system. In most cases, this is simple enough to do but there are some who appear to believe in doing away with that in favour of text box searching. It also seems that the GNOME have fallen into that trap with version 3.8 of GNOME Shell. You could add the Applications Menu extension that is formally part of the GNOME Shell Classic interface and I have done this too. However, that has been known to freeze the desktop session so I am not that big a big fan of it.
However, there is a setting that brings back those application categories in the overview screen and it can be set using dconf-editor. After opening up the application, navigate to org > gnome > shell using the tree in the left hand panel of the tool. Editing the app-folder-categories entry in the right hand panel is what adds the categories back for you. The default is [‘Utilities’, ‘Sundry’] and this needs to be changed to [‘Utilities’, ‘Games’, ‘Sundry’, ‘Office’, ‘Network’, ‘Internet’, ‘Graphics’, ‘Multimedia’, ‘System’, ‘Development’, ‘Accessories’, ‘System Settings’, ‘Other’].
Once the above has been completed, a change is noticeable in that you get a list of categories in the application overview screen and a split of application icons in the middle and categories down the right hand side. Clicking on a category brings up a new panel that contains the application within it and this can be closed again. Cycling through the categories is a process of opening and closing the different panels. The behaviour may be changed but the functionality remains and I have heard that this will be polished further in release 3.10 of GNOME Shell.
For those wanting to to exit all of this and get something like the old GNOME 2, it is possible to add the Classic Session. In Fedora 19, it’s a matter of issuing something like the following command:
sudo yum -y install gnome-classic-session
In reality, this is a case of adding a number of extensions and changing the panel colour from black to grey but it works without needing the category tweak that I described above. The Application Menu extension does need more stability hardening before I’d trust it completely though. There’s no point having a nicer interface if it’s going to freeze up on you too often.
While I have a previous posting from 2009 that discusses adding Microsoft’s Core Fonts to the then current version of Fedora, it did strike me that I hadn’t laid out the series of command that were used. Instead, I referred to an external and unofficial Fedora FAQ. That’s still there but I also felt that I was leaving things a little to chance given how websites can disappear quite suddenly.
Even after next to four years, it still amazes me that you cannot install Microsoft’s Core Fonts in Fedora as you would in Ubuntu, Linux Mint or even Debian. Therefore, the following series of steps is as necessary now as it was then.
The first step is to add in a number of precursor applications such as wget for command line file downloading from websites, cabextract for extracting the contents of Windows CAB files, rpmbuild for creating RPM installers and utilities for the XFS file system that chkfontpath needs:
sudo yum -y install rpm-build cabextract ttmkfdir wget xfs
Here, I have gone with terminal commands that use sudo but you could become the superuser (root) for all of this and there are those who believe you should. The -y switch tells yum to go ahead with prompting you for permission before it does any installations. The next step is to download the Microsoft fonts package with wget:
sudo wget http://corefonts.sourceforge.net/msttcorefonts-2.0-1.spec
Once that is done, you need to install the chkfontpath package because the RPM for the fonts cannot be built without it:
sudo rpm -ivh http://dl.atrpms.net/all/chkfontpath
Once that is in place, you are ready to create the RPM file using this command:
sudo rpmbuild -ba msttcorefonts-2.0-1.spec
After the RPM has been created, it is time to install it:
sudo yum install --nogpgcheck ~/rpmbuild/RPMS/noarch/msttcorefonts-2.0-1.noarch.rpm
When installation has completed, the process is done. Because I used sudo, all of this happened in my own home area so there was a need for some housekeeping afterwards. If you did it by becoming the root user, then the files would be there instead and that’s the scenario in the online FAQ.
Ever since the Songbird project concentrated its efforts to support only Windows and OS X, the Firefox-based music player has been absent from a Linux user’s world. However, the project is open source and a fork called Nightingale now fulfils the same needs. Intriguingly, it too is available for Windows for OS X users so I am left wondering why that overlap has happened. However, Songbird also is available as a web app and as an app on both Android and iOS while Nightingale sticks to being a desktop application.
To add it to Ubuntu, you need to set up a new repository. That can be done using the Software Centre but issuing a command in a terminal can be so much quicker and cleaner so here it is:
sudo add-apt-repository ppa:nightingaleteam/nightingale-release
Apart from entering your password, there will be prompt to continue by pressing the carriage return key or cancelling with CTRL + C. For our purposes, it is the first action that’s needed and once that’s done the needful, you can execute the following command:
sudo apt-get update && sudo apt-get install nightingale
This is in two parts: the first updates the repositories on your system and second actually installs the software. When that is complete, you are ready run Nightingale and, with the repository, staying up to date is not chore either. In fact, using the above commands brings another advantage and it is that they should in any Ubuntu derivatives such as Linux Mint.
My Epson Perfection 4490 Photo scanner has been in my possession for a while now and its impossible to justify any replacement given that it both works well and digital photography has taken over from its film predecessor for me. Every time I go installing an operating system afresh, I need to reinstate it again and last year’s installation of Ubuntu GNOME Remix 12.04 only saw me do the deed recently. When I did so, it was brought back to me that I’d never gone and documented on here how this was done. Given that I sometimes use this place as a repository of stuff to which I need to refer again in the future, it seemed remiss of me so here it is for you all.
Though I had XSane and SimpleScan already installed on the system, Sane wasn’t on there so I went and added it and a few other extras using the following command:
sudo apt-get install sane sane-utils libsane-extras
Then, it was onto the Epson website for their Perfection 4490 Photo Linux drivers since Sane’s support for this scanner seemingly remains incomplete even though it pre-dates my move to Linux in 2007. Three files were needed and the following commands install them (depending on when you do this, the file names may be different so just change them to whatever they are for you; it can be done with a single command too but there is not enough girth for that here):
sudo dpkg -i iscan-data_1.22.0-1_all.deb
sudo dpkg -i iscan_2.29.1-5~usb0.1.ltdl7_i386.deb
sudo dpkg -i iscan-plugin-gt-x750_2.1.2-1_i386.deb
With those in place, there was one other task that needed doing so that scanning could be done without resorting to running scanning software using sudo privileges. To free up the access to a normal user account, I needed a HAL device information file. These normally are in /usr/share/hal/fdi/ but they change every time an installation so any modifications that you may make are going to be lost. Therefore, there is no point modifying either /usr/share/hal/fdi/preprobe/10osvendor/20-libsane.fdi or /usr/share/hal/fdi/preprobe/10osvendor/20-libsane-extras.fdi where scanner information usually is to be found.
The first task in creating an fdi file was to issue the lsusb command and look for a line corresponding to my scanner. This is the one that I got:
Bus 001 Device 004: ID 04b8:0119 Seiko Epson Corp. Perfection 4490 Photo
From this, I gleaned the manufacturer ID and model ID as 04b8 and 0119, respectively. These are needed later on. Next I needed to create the hal/fdi/preprobe/ folder structure under /etc since it was there. Then, I created epson4490photo.fdi in the bottom folder of the tree (/etc/hal/fdi/preprobe/epson4490photo.fdi) as follows:
cd /etc/hal/fdi/preprobe/ && sudo touch epson4490photo.fdi
Then, I edited the new file using the following command:
gksu gedit epson4490photo.fdi &
When open, I added in the following text:
<?xml version="1.0" encoding="UTF-8"?>
<deviceinfo version="0.2">
<device>
<match key="info.subsystem" string="usb">
<!-- Epson Perfection 4490 Photo -->
<match key="usb.vendor_id" int="0x04b8">
<match key="usb.product_id" int="0x0119">
<append key="info.capabilities" type="strlist">scanner</append>
<merge key="scanner.access_method" type="string">proprietary</merge>
</match>
</match>
</match>
</device>
</deviceinfo>
It’s all in XML so the place to look is immediately beneath the scanner name comment. The int attributes of the two match elements immediately following the comment line are populated using the information from the lsusb command output with 0x prefixing both the manufacturer and model identifiers. The element with a key attribute of usb.vendor_id is the former and that with a key attribute of usb.product_id is the latter. With epson4490photo.fdi saved, I rebooted the machine to restart HAL and all was as I wanted it to be apart maybe from XSane making complaints that seemed not to be of any actual consequence. With Epson’s Image Scan! and Simple Scan on the PC, there’s no need to be bothered with those messages. Choice is good when you have it, especially when you have expended some effort to get that far.