Technology Tales

Adventures & experiences in contemporary technology

Removing obsolete libraries from Flatpak

1st February 2020

Along with various pieces of software, Flatpak also installs KDE and GNOME libraries needed to support them. However, it does not always remove obsolete versions of those libraries whenever software gets updated. One result is that messages regarding obsolete versions of GNOME may be issued and this has been known to cause confusion because there is the GNOME instance that is part of a Linux distro like Ubuntu and using Flatpak adds another one for its software packages to use. My use of Linux Mint may lesson the chances of misunderstanding.

Thankfully, executing a single command will remove any obsolete Flatpak libraries so the messages no longer appear and there then is no need to touch your actual Linux installation. This then is the command that sorted it for me:

flatpak uninstall --unused && sudo flatpak repair

The first part that removes any unused libraries is run as a normal user so there is no error in the above command. Administrative privileges are needed for the second section that does any repairs that are needed. It might be better if Flatpak did all this for you using the update command but that is not how the thing works. At least, there is a quick way to address this state of affairs and there might be some good reasons for having things work as they do.

Setting the PHP version in .htaccess on Apache web servers

7th September 2014

The default PHP version on my outdoors, travel and photography website is 5.2.17 and that is getting on a bit now since it is no longer supported by the PHP project and has not been thus since 2011. One obvious impact was Piwik, which I used for web analytics and needs at least 5.3.2. WordPress 4.0 even needs 5.2.24 so that upgrade became implausible so I contacted Webfusion’s support team and they showed me how to get to at least 5.3.3 and even as far as 5.5.9. The trick is the addition of a line of code to the .htaccess file (near the top was my choice) like one of the following:

PHP 5.3.x

AddHandler application/x-httpd-php53 .php

PHP 5.5.x

AddHandler application/x-httpd-php55 .php

When I got one of these in place, things started to look promising but for a locked database due to my not watching how big it had got. Replacing it with two additional databases addressed the problem of losing write access though there was a little upheaval caused by this. Using PHP 5.5.9 meant that I spotted messages regarding the deprecation of the mysql_connect function so that needed fixing too (prefixing it with @ might be a temporary fix but a more permanent one always is better so that is what I did in the form of piggybacking off what WordPress uses; MySQLi and PDO_MySQL are other options). Sorting the database issue meant that I saw the upgrade message for WordPress as well as a mix of plugins and themes so all looked better and I need worry less about losing security updates. Also, I am up to the latest version of Piwik too and that’s an even better way to be.

Amazement

1st March 2014

During the latter part of last year, the magazine Linux Format suffered a staff clear-out and I was left wondering why. It was as if a load of folk left at once and, even if I have seen that sort of thing happening at my current place of work, I was asking if something went wrong at Future Publishing.

What had passed me by was that the then staff of Linux Format were working on starting up their own magazine. They then went about crowdfunding the thing on Indiegogo and it only was the appearance of Linux Voice on a shelf in the Macclesfield branch of WHSmith’s that alerted me to what was happening in previous months.

It does sound risky to have an entire bunch of folk from one publisher’s magazine go off on their own and do their own variant of it, especially in these digital days when magazine publishing is not as secure as it once was. The mention of someone being held by no-compete covenant that reminded me of the mindset of where I work for a living. Quite what their old employers must make of it would make interesting reading because mine might be tempted to see me in court if I did something similar, assuming that was a possibility; I too would be bound by a covenant for six months after leaving.

As for the magazine itself, the content is good like it needs to be. There may be the occasional misspelling but articles on OwnCloud and Arch Linux installation would draw my attention along with reviews of Mageia 4 and FreeBSD 10. A lot of the old names from Linux Format appear too so there’s an air of continuity there. The design of the new upstart is less flashy than its longer standing predecessor and it will be interesting to see how they coexist.

It will take time for any new ideas to come to fruition and I wish the new magazine well. Its intentions are good in that half if profits are to go to open source software projects and articles are to be made available to all under a Creative Commons licence. First though, it needs to stay financially viable and the coming months could be interesting. The collective experience of who is behind the magazine should help though and that might stop it becoming like Walking World Ireland and Cycling World, other magazines whose appearance in newsagents is occasional. Having support from an enthusiastic community is a bonus too and there may come a time when I have to decide between Linux Voice and Linux Format as is the case with Linux Magazine and Linux User & Developer.  For what is supposed to be a niche operating system, users of Linux are not badly served when it comes to magazines.

Setting up a WD My Book Live NAS on Ubuntu GNOME 13.10

1st December 2013

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.

A reappraisal of Windows 8 and 8.1 licensing

15th November 2013

With the release of Windows 8 around this time last year, I thought that the full retail version that some of us got for fresh installations on PC’s, real or virtual, had become a thing of the past. In fact, it did seem that every respecting technology news website and magazine was saying just that. The release that you would buy from Microsft or from mainstream computer stores was labelled as an upgrade. That made it look as if you needed the OEM or System Builder edition for those PC’s that needed a new Windows installation and that the licence that you bought was then attached to the machine from when it got installed on there.

As is usual with Microsoft, the situation is less clear cut than that. For instance, there was some back-pedalling to allow OEM editions of Windows to be licensed for personal use on real or virtual PC’s. With Windows & and its predecessors, it even was possible to be able to install afresh on a PC without Windows by first installing on inactivated copy on there and then upgrading that as if it was a previous version of Windows. Of course, an actual licence was of the previous version of Windows was needed for full compliance if not the actual installation. At times, Microsoft muddies waters so as to keep its support costs down.

Even with Microsoft’s track record in mind, it still did surprise me when I noticed that Amazon was selling what appeared to be full versions of both Windows 8.1 and Windows 8.1 Pro. Having set up a 64-bit VirtualBox virtual machine for Windows 8.1, I got to discovering the same for software purchased from the Microsoft web site. However, unlike the DVD versions, you do need an active Windows installation if you fancy a same day installation of the downloaded software. For those without Windows on a machine, this can be as simple as downloading either the 32-bit or the 64-bit 90 day evaluation editions of Windows 8.1 Enterprise and using that as a springboard for the next steps. This not only be an actual in-situ installation but there options to create an ISO or USB image of the installation disk for later installation.

In my case, I created a 64-bit ISO image and used that to reboot the virtual machine that had Windows 8.1 Enterprise on there before continuing with the installation. By all appearances, there seemed to be little need for a pre-existing Windows instance for it to work so it looks as if upgrades have fallen by the wayside and only full editions of Windows 8.1 are available now. The OEM version saves money so long as you are happy to stick with just one machine and most users probably will do that. As for the portability of the full retail version, that is not something that I have tested and I am unsure that I will go beyond what I have done already.

My main machine has seen a change of motherboard, CPU and memory so it could have de-activated a pre-existing Windows licence. However, I run Linux as my main operating system and, apart possibly from one surmountable hiccup, this proves surprisingly resilient in the face of such major system changes. For running Windows, I turn to virtual machines and there were no messages about licence activation during the changeover either. Microsoft is anything but confiding when it comes to declaring what hardware changes inactivate a licence. Changing a virtual machine from VirtualBox to VMware or vice versa definitely so does it so I tend to avoid doing that. One item that is fundamental to either a virtual or a real PC is the mainboard and I have seen suggestions that this is the critical component for Windows licence activation and it would make sense if that was the case.

However, this rule is not hard and fast either since there appears to be room for manoeuvre should your PC break. It might be worth calling Microsoft after a motherboard replacement to see if they can help you and I have seen that it is. All in all, Microsoft often makes what appear to be simple rules only to override them when faced with what happens in the real world. Is that why they can be unclear about some matters at times? Do they still hanker after how they want things to be even when they are impossible to keep like that?

Turning off seccomp sandbox in vsftpd

21st September 2013

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.

WARNING: Engine XPORT does not support SORTEDBY operations. SORTEDBY information cannot be copied.

24th July 2012

When recently creating a transport file using PROC COPY and the XPORT library engine, I found the above message in the log. The code used was similar to the following:

libname tran xport "c:\temp\tran.xpt";

proc copy in=data out=tran;
run;

When I went seeking out the cause on the web, I discovered this SAS Note that dates from before the release of SAS 6.12, putting the issue at more than ten years old. My take on its continuing existence is that we still to use a transport file format that was introduced in SAS 5.x for sake of interoperability, both between SAS versions and across alternatives to the platform.

The SORTEDBY flag in a dataset header holds the keys used to sort the data and it isn’t being copied into the XPORT transport files, hence the warning. To get rid of it, you need to remove the information manually in data step using the SORTEDBY option on the DATA statement or using PROC DATASETS, which avoids rewriting the entire data set.

First up is the data step option:

data test(sortedby=_null_);
set sashelp.class;
run;

Then, there’s PROC DATASETS:

proc datasets;
modify test(sortedby=_null_);
run;
quit;

It might seem counterproductive to exclude the information but it makes no sense to keep what’s being lost anyway. So long as the actual sort order is unchanged, and I believe that the code that that below will not alter it, we can live with its documentation in a specification until transport files created using PROC CPORT are as portable as those from PROC COPY.

Getting Gnome Shell going for Fedora 16 running in VirtualBox

5th December 2011

There are a number of complaints out there about how hard it is to get GNOME Shell running for a Fedora 16 installation in a VirtualBox virtual machine. As with earlier versions of Fedora, preparation remains a matter of having make, gcc and kernel-devel (kernel headers, in other words). While I have got away with just those, adding dkms (dynamic kernel module support) to the list might be no bad idea either. To get all of those instated, it is a matter of running the following command as root or using sudo:

yum -y install make gcc kernel-devel dkms

The -y switch ensures that any Y/N prompts that usually appear are suppressed and that the installation is completed. Just leave it out if you are inclined to get second thoughts. Another item that has been needed with a previous release of Fedora is libgomp but I haven’t had to add this for Fedora 16 if I remember correctly.

Once those are in place, it is time to install the VirtualBox Guest Additions.  Going to Devices > Install Guest Additions… mounts a virtual CD that can be used for the installation of the various drivers that are needed. To do the installation, first go to where the installer is located using the following command:

cd /media/VBOXADDITIONS_4.1.6_74713/

Note that this location will change according to the release and build numbers of VirtualBox but the process essentially will be the same other than this. Once in there, issue the following command as root or using sudo:

./VBoxLinuxAdditions.run

Hopefully, this will complete without errors now with the precursor software that has been added beforehand. However, there is one more thing that needs doing or you will get the GNOME 3 fallback desktop instead. It pertains to SELinux, an old adversary of mine that got in the way when I was setting up a web server on a machine running Fedora. It doesn’t recognise the new VirtualBox drivers as it should so the following command needs executing as root or using sudo:

restorecon -R -v /opt

Doing this restores the SELinux contexts for the /opt directories within which the VirtualBox software directories are found. The -R switch tells it to act recursively and -v makes it verbose. When it has done its work, hopefully successfully, it is time to reboot the virtual machine and you should have a GNOME Shell desktop interface when you log in.

Is Windows 2000 support finished?

30th March 2007

At work, we still use Windows 2000 on our desktop and laptop PC’s. This may (or may not) surprise you but the XP upgrade seems to have been thought a premature move and Vista turned up later than might have been expected. Now that Microsoft is winding down support for Windows 2000, thoughts have started to turn to a Vista upgrade, but the realisation soon dawned that a move to Vista was a major one and it now looks as if we will be on Windows 2000 for a little while yet, until 2008 at least.

I, too, have Windows 2000 lurking around at home as a testing platform, not a work copy I hasten to add, and software vendors increasingly are not supporting the operating system any more. Symantec is one of these with the 2006 versions of its products being the last ones to support Windows 2000. Initially, I was left with the impression that Kaspersky was the same, but this does not seem to be the case. While the open-source community can continue their supply of productivity applications such as OpenOffice, the GIMP and so on, it is the security side that is of most concern as regards the future of Windows 2000. That said, its successors are not the prime targets for cracking but shared code could mean that it falls foul of the same exploits.

I have yet to notice it with the hardware that I am using, but hardware advances may yet put paid to Windows 2000 like they did to members of the Windows 9x line, especially when you consider that the operating system dates from 1999. Then again, you may find that you don’t need the latest hardware, so this might not affect you. This is not all that unreasonable given that the pace of technological progress is less frenzied these days than it was in the nineties when Windows 95 was more or less out of date by the turn of the millennium. Having the gold OEM version of Windows 95 as the basis for a Windows 9x upgrade treadmill meant that my move into the world of NT-based operating systems was a clean break with a full version of my new operating system and not its upgrade edition.

Nevertheless, there remains a feeling that Windows 2000 is being cut off prematurely and that it could last a while longer with a bit of support, even if there is a late nineties feel to the thing. After all, Windows 2000 probably still supports a lot of what people want to do and without the Big Brother tendencies of Vista too.

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