Adventures & experiences in contemporary technology
The changes made to Nautilus, otherwise known as Files, in GNOME Shell 3.6 were contentious and the response of the Linux Mint was to create their own variant called Nemo from the previous version of the application. On the Cinnamon or MATE desktop environments, the then latest version of GNOME’s file manager would have looked like a fish out of water without its application menu in the top panel on the GNOME Shell desktop. It is possible to make a few modifications that help Nautilus to look more at home on those Linux Mint desktops and I have collected them here because they are useful for GNOME Shell users too. Here they are in turn.
Adding Application Menu entries to Location Options Menu
The Location Options menu is what you get on clicking the button with the cog icon on the right-hand side of the application’s location bar. Using Gsettings, it is possible to make that menu include the sort of entries that are in the application menu in the GNOME Shell panel at the top of the screen. These include an entry for closing the whole application as well as setting its preferences (or options). Running the following command does just that (if it does not work as it should, try changing the single and double quotes to those understood by a command shell):
gsettings set org.gnome.settings-daemon.plugins.xsettings overrides '@a{sv} {"Gtk/ShellShowsAppMenu": <int32 0>}'
Adding in the Remove App Menu GNOME Shell extension will clean up the GNOME Shell a little by removing the application menu altogether. If, for some reason, you wish to restore the default behaviour, then the following command does the required reset:
gsettings set org.gnome.settings-daemon.plugins.xsettings overrides '@a{sv} {}'
Stopping Hiding of the Application Title Bar When Maximised
By default, GNOME Shell can hide the application title bars of GNOME applications such as Nautilus on window maximisation and this is Nautilus now works by default. Changing the behaviour so that the title bar is kept on maximised windows can be as simple as adding in the ignore_request_hide_titlebar extension. The trouble with GNOME Shell extensions is that they can stop working when a new version of GNOME Shell is used, so there’s another option: editing metacity-theme-3.xml but /usr/share/themes/Adwaita/metacity-1. The file can be opened using superuser privileges using the following command:
gksudo gedit /usr/share/themes/Adwaita/metacity-1/metacity-theme-3.xml
With the file open, it is a matter of replacing instances of ' has_title="false" ' with ' has_title="true" ', saving it and reloading GNOME Shell. This may persevere across different versions of GNOME Shell should the extension not do so.
Disabling Recursive Search
This discovery is what led me to bundle these customisations in an entry on here in the first place. In Nemo and older versions of Nautilus, just typing with the application open would lead you down a list towards the file that you wanted. This behaviour was replaced by an automatic recursive search from GNOME Shell 3.6 where the search functionality was extended beyond the folder that was open in the file manager to its subdirectories. To change that to subsetting within the open folder or directory, you need to install a patch version of Nautilus using the following commands:
sudo add-apt-repository ppa:dr3mro/personal
sudo apt-get update && sudo apt-get upgrade
The first of these adds a new repository with the patched version of Nautilus while the second combination installs the patched version. With that done, it is time to issue the following command:
gsettings set org.gnome.nautilus.preferences enable-recursive-search false
That sets the value of the new enable-recursive-search option to false for searching within an open directory. It also can be found using Dconf-Editor in the following hierarchy: org -> gnome -> nautilus -> preferences. The obsession of the GNOME project team with minimalism is robbing users of some options and this would be a good one to have by default too. Maybe the others should be treated in the same way even if you need to use Gsettings or Dconf-Editor to change them to avoid clutter. Having GNOME Tweak Tool able to set them all would be even better.
A few years back, I came across a very nice article discussing how you would make a dynamic URL more palatable to a search engine and I made good use of its content for my online photo gallery. The premise was that URL’s that look like that below are no help to search engines indexing a website. Though this is received wisdom in some quarters, it doesn’t seem to have done much to stall the rise of WordPress as a blogging platform.
http://www.mywebsite.com/serversidescript.php?id=394
That said, WordPress does offer a friendlier URL display option too and you can see this in use on this blog; they look a little like the example URL that you see below, and the approach is equally valid for both Perl and PHP. I have been using the same approach for the Perl scripts powering my online phone gallery and now want to apply the same thinking to a gallery written in PHP:
http://www.mywebsite.com/serversidescript.pl/id/394
The way that both expressions work is that a web server will chop pieces from a URL until it reaches a physical file. For a query URL, the extra information after the question mark is retained in its QUERY_STRING variable while extraneous directory path information is passed in the variable PATH_INFO. For both Perl and PHP, these are extracted from the entries in an array; for Perl, this array is called is $ENV and $_SERVER is the PHP equivalent. Thus, $ENV{QUERY_STRING} and $_SERVER{‘QUERY_STRING’} traps what comes after the “?” while $ENV{PATH_INFO} and $_SERVER{‘PATH_INFO’} picks up the extra information following the file name (the “/id/394/” in the example). From there on, the usual rules apply regarding cleaning of any input but changing from one to another should be too arduous.
When I wrote about tidying dynamic URL’s a little while back, I had no inkling that that would be a second part to the tale. My discovery of mod_rewrite, an Apache module that facilitates URL translation. The effect is that one URL is presented to the user in the browser address bar, and the exact same URL is also seen by search engines, while another is passed to the server for processing. It might sound like subterfuge but it works very well once you manage to get it set up properly. The web host for my hillwalking blog/photo gallery has everything configured such it is ready to go but the same did not apply to the offline Apache 2.2.x server that I have going on my own Windows XP box. There were two parts to getting it working there:
Once you have got the above sorted, adding this line to .htaccess: RewriteEngine On. Preceding it with an Options directive to ensure that FollowSymLinks and SymLinksIfOwnerMatch are switched on does no harm at all and may even be needed to get things running. That done, you can set about putting mod_write to work with lines like this:
RewriteRule ^pages/(.*)/?$ pages.php?query=$1
The effect of this is to take http://www.website.com/pages/input and convert it into a form for action by the server; in this case, that is http://www.website.com/pages.php?query=input. Anything contained by a bracket is assigned to the value of a system-named variable. If you have several bracketed sections, they are assigned to sequentially numbered variables as follows: $1 for the first, $2 for the second and so on. It’s all good stuff when you get it going and not only does it make things look much neater but it also possesses an advantage when it comes to future-proofing too. Web addresses can be kept constant over time, even if things change behind the scenes. It means that returning visitors will find what they saw the last time that they visited and surely must ensure good karma in eyes of those all important search engines.
On checking the Site Health page of a WordPress blog, I saw errors that pointed to a problem with its SSL set up. The www subdomain was not included in the site’s certificate and was causing PHP errors as a result though they had no major effect on what visitors saw. Still, it was best to get rid of them so I needed to update the certificate as needed. Execution of a command like the following did the job:
sudo certbot --expand -d existing.com,www.example.com
Using a Let’s Encrypt certificate meant that I could use the certbot command since that already was installed on the server. The --expand and -d switches ensured that the listed domains were added to the certificate to sort out the observed problem. In the above, a dummy domain name is used but this was replaced by the real one to produce the desired effect and make things as they should have been.
There are times when blogs cease to exist and the only place to find the content is on the Wayback Machine. Even then, it is in danger of being lost completely. One such example is the subject of this post.
Though this website makes use of the facilities of Cloudflare for various functions that include the blocking of image hotlinking, the same outcome can be achieved using .htaccess files on Apache web servers. It may work on Nginx to a point too but there are other configuration files that ought to be updated instead of using a .htaccess when some frown upon the approach. In any case, the lines that need adding to .htaccess are listed below though the web address needs to include your own domain in place of the dummy example provided:
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?yourdomain.com(/)?.*$ [NC]
RewriteRule .*\.(gif|jpe?g|png|bmp)$ [F,NC]
The first line turns on the mod_rewrite engine and you may have that done anyway. Of course, the module needs enabling in your Apache configuration for this to work and you have to be allowed to perform the required action as well. This means changing the Apache configuration files. The next pair of lines look at the HTTP referer strings and the third one only allows images to be served from your own web domain and not others. To add more, you need to copy the third line and change the web address accordingly. Any new lines need to precede the last line that defines the file extensions that are to be blocked to other web addresses.
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?yourdomain.com(/)?.*$ [NC]
RewriteRule \.(gif|jpe?g|png|bmp)$ /images/image.gif [L,NC]
Another variant of the previous code involves changing the last line to display a default image showing others what is happening. That may not reduce the bandwidth usage as much as complete blocking but it may be useful for telling others what is happening.
Recent curiosity about Java programming and Groovy scripting got me trying to start up the Eclipse IDE that I had install on my main machine. What I got instead of a successful application startup was a message that included the following:
!MESSAGE Exception launching the Eclipse Platform:
!STACK
java.lang.ClassNotFoundException: org.eclipse.core.runtime.adaptor.EclipseStarter
at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:466)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:566)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:626)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
at org.eclipse.equinox.launcher.Main.run(Main.java:1438)
at org.eclipse.equinox.launcher.Main.main(Main.java:1414)
The cause was a mismatch between Eclipse and the installed version of Java that it needed in order to run. After all, the software itself is written in the Java language and the installed version from the usual software repositories was too old for Java 11. The solution turned out to be installing a newer version as a Snap (Ubuntu’s answer to Flatpak). The following command did the needful since Snapd already was running on my machine:
sudo snap install eclipse --classic
The only part of the command that warrants extra comment is the --classic switch since that is needed for a tool like Eclipse that needs to access a host file system. On executing, the software was downloaded from Snapcraft and then installed within its own bundle of dependencies. The latter adds a certain detachment from the underlying Linux installation and ensures that no messages appear because of incompatibilities like the one near the start of this post.
For all the world, it looks like Microsoft has mined a concept from a not often recalled series of Windows: 3.x. Then, we had a Program Manager for starting all our applications with no sign of a Start Menu. That came with Windows 95 and I cannot anyone mourning the burying of the Program Manager interface either. It was there in Windows 95 if you knew where to look and I do remember starting an instance, possibly out of curiosity.
Every Windows user seems to have taken to the Start Menu regardless of how big they grow when you install a lot of software on your machine. It didn’t matter that Windows NT got it later than Windows 9x ones either; NT 3.51 has the Program Manager too and it was NT 4 that got the then new interface that has been developed and progressed in no less than four subsequent versions of Windows (2000, XP, Vista & 7). Maybe it was because computing was the preserve of fewer folk that the interchange brought little if any sign of a backlash. The zeitgeist of the age reflected the newness of desktop computing and its freshness probably brought an extra level of openness too.
Things are different now, though. You only have to hear of the complaints about changes to Linux desktop environments to realise how attached folk become to certain computer interfaces. Ironically, personal computing has just got exciting again after a fairly stale decade of stasis. Mobile computing devices are aplenty and it no longer is a matter of using a stationary desktop PC or laptop and those brought their own excitement in the 1990’s. In fact, reading a title like Computer Shopper reminds me of how things once were with its still sticking with PC reviews while others are not concentrating on them as much. Of course, the other gadgets get reviewed too so it is not stuck in any rut. Still, it is good to see the desktop PC getting a look in in an age when there is so much competition, especially from phones and tablets.
In this maelstrom, Microsoft has decided to do something dramatic with Windows 8. It has resurrected the Program Manager paradigm in the form of the Start screen and excised the Start Menu from the desktop altogether. For touch screen computing interfaces such as tablets, you can see the sense of this but it’s going to come as a major surprise to many. Removing what lies behind how many people interact with a PC is risky and you have to wonder how it’s going to work out for all concerned.
What reminded me of this was a piece on CNET by Mary Jo Foley. Interestingly, software is turning up that returns the Start Menu (or Button) to Windows 8. One of these is Classic Shell and I decided to give it a go on a Windows 8 Enterprise evaluation instance that I have. Installation is like any Windows program and I limited the options to the menu and updater. At the end of the operation, a button with a shell icon appeared on the desktop’s taskbar. You can make the resultant menu appear like that of Windows XP or Windows 7 if you want. There are other settings like what the Windows key does and what happens when you click on the button with a mouse. By default, both open the new Start Menu and holding down the Shift key when doing either brings up the Start screen. This is customisable so you can have things the other way around if you so desire. Another setting is to switch from the Start screen to the desktop after you log into Windows 8 (you may also have it log in for you automatically but it’s something that I believe anyone should be doing). The Start screen does flash up but things move along quickly; maybe having not appear at all would be better for many.
Classic Shell is free of charge and worked well for me apart from that small rough edge noted above. It also is open source and looks well maintained too. For that reason, it appeals to me more that Stardock’s Start8 (currently in beta release at the time of writing) or Pokki for Windows 8, which really is an App Store that adds a Start Menu. If you encounter Windows 8 on a new computer, then they might be worth trying should you want a Start Menu back. Being an open-minded type, I could get along with the standard Windows 8 interface but it’s always good to have choices too. Most of us want to own our computing experience, it seems, so these tools could have their uses for Windows 8 users.
Being ever curious on the technology front, the release of the first build of a Technical Preview of Windows 10 was enough to get me having a look at what was on offer. The furore regarding Windows 8.x added to the interest so I went to the download page to get a 64-bit installation ISO image.
That got installed into a fresh VirtualBox virtual machine and the process worked smoothly to give something not so far removed from Windows 8.1. However, it took until release 4.3.18 of VirtualBox before the Guest additions had caught up with the Windows prototype so I signed up for the Windows Insider program and got a 64-bit ISO image to install the Enterprise preview of Windows 10 into a VMware virtual machine since and that supported full screen display of the preview while VirtualBox caught up with it.
Of course, the most obvious development was the return of the Start Menu and it works exactly as expected too. Initially, the apparent lack of an easy way to disable App panels had me going to Classic Shell for an acceptable Start Menu. It was only later that it dawned on me that unpinning these panels would deliver to me the undistracting result that I wanted.
Another feature that attracted my interest is the new virtual desktop functionality. Here I was expecting something like what I have used on Linux and UNIX. There, each workspace is a distinct desktop with only the applications open in a given workspace showing on a panel in there. Windows does not work that way with all applications visible on the taskbar regardless of what workspace they occupy, which causes clutter. Another deficiency is not having a desktop indicator on the taskbar instead of the Task View button. On Windows 7 and 8.x, I have been a user of VirtuaWin and this still works largely in the way that I expect of it too, except for any application windows that have some persistence associated with them; the Task Manager is an example and I include some security software in the same category too.
Even so, here are some keyboard shortcuts for anyone who wants to take advantage of the Windows 10 virtual desktop feature:
Otherwise, stability is excellent for a preview of a version of Windows that is early on its road to final release. An upgrade to a whole new build went smoothly when initiated following a prompt from the operating system itself. All installed applications were retained and a new taskbar button for notifications made its appearance alongside the existing Action Centre icon. So far, I am unsure what this does and whether the Action Centre button will be replaced in the fullness of time but I am happy to await where things go with this.
All is polished up to now and there is nothing to suggest that Windows 10 will not be to 8.x what 7 was to Vista. The Start Screen has been dispatched after what has proved to be a misadventure on the part of Microsoft. The PC still is with us and touchscreen devices like tablets are augmenting it instead of replacing it for any tasks involving some sort of creation. If anything, we have seen the PC evolve with laptops perhaps becoming more like the Surface Pro, at least when it comes to hybrid devices. However, we are not as happy smudge our PC screens quite like those on phones and tablets so a return to a more keyboard and mouse centred approach for some devices is a welcome one.
What I have here are just a few observations and there is more elsewhere, including a useful article by Ed Bott on ZDNet. All in all, we are early in the process for Windows 10 and, though it looks favourable so far, I will continue to keep an eye on how it progresses. It needs to be less experimental than Windows 8.x and it certainly is less schizophrenic and should not be a major jump for users of Windows 7.
If you had asked me about getting two or more graphs on a page using SAS/GRAPH procedures, I might have suggested PROC GREPLAY as the means to achieve it. However, I recently came across another way to do the same thing by using ODS. It helped that the graphs were being produced using the PDF destination because I don’t think that what follows will work with the RTF one.
For this three plots on a page example, I first set the orientation to landscape so that the plots can be arranged side by side in a single row:
options orientation=landscape;
Next, the PDF destination was opened with page breaks turned off for the required output file using the STARTPAGE option:
ods pdf file="c:\test.pdf" startpage=off;
The listing destination was turned off as well since it is not needed:
ods listing close;
With that complete, a page or region break gets inserted. This could have been repeated before every procedure to get it popped into the next region on the page but that is the default behaviour for any extra procedural step so it wasn’t needed.
ods pdf startpage=now;
Then, the ODS LAYOUT feature is started so that the layout can be defined on the page:
ods layout start;
For the first plot and the one at the left of the triptych, a region was defined absolutely (grid layouts are available but I didn’t make use of them here) using ODS REGION. Since all plots were to be of the same size, the width was defined as being a third of the page and the bottom left hand corner of the region defined to be the same as that of the plot area on the page. Titles and footnotes usefully lie outside this region in the way that SAS arranges things so there is no further messing. With the region define, it’s a matter of running the required SAS/GRAPH procedure. In my case, this was GPLOT but I am certain that others would work as well. The height was defined as the full possible plot height. This could have a use if I wanted more than one row of graphs on a page with a trellis plot being an example of that sort of arrangement.
ods region x=0pct y=0pct width=33pct height=100pct;
<< SAS/GRAPH Procedure >>
For the middle plot, the starting position is moved a third of the way along the page while the section area has the same dimensions as before. Using percentages in these definitions does make their usage easier.
ods region x=33pct y=0pct width=33pct height=100pct;
<< SAS/GRAPH Procedure >>
Lastly, the right-hand plot has a starting position two-thirds of the width of the page and the other dimensions are as per the other panels:
ods region x=66pct y=0pct width=33pct height=100pct;
<< SAS/GRAPH Procedure >>
With the last graph created, it is time to close ODS LAYOUT and the PDF destination. Then, the listing destination is reopened again.
ods layout end;
ods pdf close;
ods listing;
Update 2012-12-08: Since writing the above, I have learned that ODS LAYOUT and ODS REGION have yet to become production features of SAS with 9.3 as the latest version. However, I have encountered an alternative that uses the STARTPAGE=NEVER ODS PDF option to turn off page breaks and GOPTIONS statements to control the regions occupied by plots. It’s Sample 48569 on the SAS website. Having a production equivalent is better since pre-production features are best avoided in production code. If I had realised the status, I would have used PROC GREPLAY to achieve what I needed to do.
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.