Technology Tales

Overriding replacement of double or triple hyphenation in WordPress

On here, I have posts with example commands that include double hyphens, and they have been displayed merged together, something that has resulted in a comment posted by a visitor to this part of the web. All the while, I have been blaming the fonts that I have been using, only for it to be the fault of WordPress itself.

Changing multiple dashes to something else has been a feature of Word autocorrect, but I never expected to see WordPress aping that behaviour, and it has been doing so for a few years now. The culprit is wptexturize and that cannot be disabled, for it does many other useful things.

What happens is that the wptexturize filter changes '--' (double hyphens) to '–' (– in web entity encoding) and '---' (triple hyphens) to '—' (— in web entity encoding). The solution is to add another filter to the content that changes these back to the way they were, and the following code does this:

add_filter( 'the_content' , 'mh_un_en_dash' , 50 );
function mh_un_en_dash( $content ) {
$content = str_replace( '–' , '--' , $content );
$content = str_replace( '—' , '---' , $content );
return $content;
}

The first line of the segment adds in the new filter that uses the function defined below it. The third and fourth lines above do the required substitution before the function returns the post content for display in the web page. The whole code block can be used to create a plugin or placed in the theme's functions.php file. Either way, things appear without the substitution, confusing your readers. It makes me wonder if a bug report has been created for this because the behaviour looks odd to me.

Compressing a VirtualBox VDI file for a Linux guest

In a previous posting, I talked about compressing a virtual hard disk for a Windows guest system running in VirtualBox on a Linux system. Since then, I have needed to do the same for a Linux guest following some housekeeping. Because the Linux distribution used is Debian, the instructions are relevant to that and maybe its derivatives such as Ubuntu, Linux Mint and their like.

While there are other alternatives like dd, I am going to stick with a utility named zerofree to overwrite the newly freed up disk space with zeroes to aid compression later on in the process for this and the first step is to install it using the following command:

apt-get install zerofree

Once that has been completed, the next step is to unmount the relevant disk partition. Luckily for me, what I needed to compress was an area that I reserved for synchronisation with Dropbox. If it was the root area where the operating system files are kept, a live distro would be needed instead. In any event, the required command takes the following form, with the mount point being whatever it is on your system (/home, for instance):

sudo umount [mount point]

With the disk partition unmounted, zerofree can be run by issuing a command that looks like this:

zerofree -v /dev/sdxN

Above, the -v switch tells zerofree to display its progress and a continually updating percentage count tells you how it is going. The /dev/sdxN piece is generic with the x corresponding to the letter assigned to the disk on which the partition resides (a, b, c or whatever) and the N is the partition number (1, 2, 3 or whatever; before GPT, the maximum was 4). Putting all this together, we get an example like /dev/sdb2.

Once, that had completed, the next step is to shut down the VM and execute a command like the following on the host Linux system ([file location/file name] needs to be replaced with whatever applies on your system):

VBoxManage modifyhd [file location/file name].vdi --compact

With the zero filling in place, there was a lot of space released when I tried this. While it would be nice for dynamic virtual disks to reduce in size automatically, I accept that there may be data integrity risks with those, so the manual process will suffice for now. It has not been needed that often anyway.

Getting rid of Windows 10 notifications about disabling start-up applications

On several Windows 10 machines, I have been seeing messages appearing in its Action Centre pane with the heading Disable apps to help improve performance. It appeared again recently, so I decided to look further into the matter.

What I found was that the solution first involves opening up the Control Panel, which takes a little finding in Windows 10. You could use Cortana to get to it or right-clicking on the Start Menu and left-clicking on the Control Panel menu. Using the Windows key + X will produce the same menu, and choosing the same entry will have the same effect.

Once the Control Panel is open, it makes life a little easier if you change to the Large icons view using the drop-down menu under the Search Control Panel box on the right-hand side. Then, what you need to do is click on the Security and Maintenance icon.

Once in that Security and Maintenance section, you are presented with two subheadings, one for Security and one for Maintenance. So long as you have not dismissed the message in the action centre, you will see a corresponding entry under the Maintenance section. At the bottom of that entry, there will be a link that turns off these messages permanently, and clicking on this will have the desired effect.

Turning off push notifications in Firefox 46

Firefox 44 introduced a feature I only recently noticed when Yahoo Mail offered browser notifications for new emails; I did not need this and could not switch it off permanently for that site. This meant I was bothered each time I checked that email address, an unnecessary irritation. Other websites offered similar push notifications but allowed permanent deactivation, making this a site-specific function unless you take an alternative approach.

Open a new browser tab and enter about:config in the address bar, then press return. If this is your first time, a warning message will appear, which you can dismiss permanently. This reveals a searchable list of options. Find dom.webnotifications.enabled and dom.webnotifications.serviceworker.enabled. By default, these values are set to 'true'. Double-click each one to change them to 'false'. This will prevent push notification offers from web services like Yahoo Mail, reducing intrusions during your browsing.

Compressing a VirtualBox VDI file for a Windows guest running on a Linux Host

Recently, I had a situation where my the VDI files for my Windows 10 virtual machine expanded in size all of a sudden and I needed to reduce them. My downloading maps for use with RouteBuddy may have been the cause, so I moved the ISO installation files onto the underlying Linux Mint drives. With that space, I then set to uncovering how to compact the virtual disk file, and the Sysinternals sdelete tool was recommended for clearing unused space. After downloading, I set it to work in a PowerShell session running on the guest operating system from its directory using the following command:

.\sdelete -z [drive letter designation; E: is an example]

From the command prompt, the following should do:

sdelete -z [drive letter designation; E: is an example]

Once, that had completed, I shut down the VM and executed a command like the following from a bash terminal session:

VBoxManage modifyhd [file location/file name].vdi --compact

Where there was space to release, VDI files were reduced in size to return more disk space. More could be done, so I will look into the Windows 10 drives to see what else needs to be moved out of them.

Killing Windows processes from the command line

During my days at work, I often hear about the need to restart a server because something has gone awry with it. This makes me wonder if you can kill processes from the command line, like you do in Linux and UNIX. A recent need to reset Windows Update on a Windows 10 machine gave me enough reason to answer the question.

Because I already knew the names of the services, I had no need to look at the Services tab in the Task Manager like you otherwise would. Then, it was a matter of opening up a command line session with Administrator privileges and issuing a command like the following (replacing [service name] with the name of the service):

sc queryex [service name]

From the output of the above command, you can find the process identifier, or PID. With that information, you can execute a command like the following in the same command line session (replacing [PID] with the actual numeric value of the PID):

taskkill /f /pid [PID]

After the above, the process no longer exists and the service can be restarted. With any system, you need to find the service that is stuck to kill it, but that would be the subject of another posting. What I have not got to testing is whether these work in PowerShell, since I used them with the legacy command line instead. Along with processes belonging to software applications (think Word, Excel, Firefox, etc.), that may be something else to try should the occasion arise.

WARNING: No bars were drawn. This could have been caused by ORDER= on the AXIS statement. You might wish to use the MIDPOINTS= option on the VBAR statement instead.

What you see above is an error issued by a SAS program, akin to what a colleague at work recently found. The following code will reproduce this, so let us walk through the steps to explain a possible cause for this.

The first stage is to create a test dataset containing variables y and x, for the vertical and midpoint axes, respectively, and populating these using a CARDS statement in a data step:

data a;
    input y x;
    cards;
    1 5
    3 9
    ;
run;

Now, we define an axis with tick marks for particular values that will be used as the definition for the midpoint or horizontal axis of the chart:

axis1 order=(1 3);

Then, we try creating the chart using the GCHART procedure that comes with SAS/GRAPH and this is what results in the error message being issued in the program log:

proc gchart data=a;
    vbar x / freq=y maxis=axis1;
    run;
quit;

The cause is that the midpoint axis tick marks are not included in the data, so changing these to the actual values of the x variable removes the message and allows the creation of the required chart. Thus, the AXIS1 statement needs to become the following:

axis1 order=(5 9);

Another solution is to remove the MAXIS option from the VBAR statement and let GCHART to be data-driven. However, if requirements do not allow this, create a shell dataset with all expected values for the midpoint axis with y set 0 since that is used for presenting frequencies as per the FREQ option in the VBAR statement.

Resolving Windows Update Error 0x80244019 on Windows 10

In Windows 10, the preferred place to look if you fancy prompting an update of the system is in the Update & Security section of the Settings application. At the top is the Windows Update, and the process usually is as simple as pressing the Check for updates button. For most of the time, that has been my experience, but it stopped working on my main Windows 10 virtual machine, so I needed to resolve the problem.

Initially, going into the Advanced Options section and deselecting the tick box for Give me updates for other Microsoft products when I update Windows helped. However, it seemed a non-ideal solution, so I looked further. When it was then that I found that manually resetting a system's Windows Updates components helped others, I tried that and restarted the system.

The first part of the process was to right-click on the Start Menu button and select the Windows PowerShell (Admin) entry from the menu that appeared. This may be replaced by Command Prompt (Admin) on your system on your machine, but the next steps in the process are the same. In fact, you could include any commands you see below in a script file and execute that if you prefer. Here, I will run through each group in succession.

From either PowerShell or the Command Prompt, you need to stop the Windows Update, Cryptographic, BITS (or Background Intelligent Transfer Service) and MSI Installer services. To accomplish this, execute the following commands at a command prompt:

net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver

With the services stopped, it is then possible to rename the SoftwareDistribution and Catroot2 folders so you can refresh everything to remove them. To accomplish this, execute the following pair of commands using either PowerShell or the Command Prompt:

ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 Catroot2.old

Once you have the folders renamed, then you can start the Windows Update, Cryptographic, BITS and MSI Installer services by executing the following commands in either PowerShell or the Command Prompt:

net start wuauserv
net start cryptSvc
net start bits
net start msiserver

Once these have completed, you may close the PowerShell or Command Prompt window that you were using and restart the machine. Going into the Update & Security section of the Settings tool afterwards and pressing the Check for updates button now builds new versions of the folders that you renamed, and this takes a little while longer than the usual update process. Otherwise, you could let your system rebuild things in its own time. As it happens, I opted for manual intervention and all has worked well since then.

Creating soft and hard symbolic links using the Windows command line

In the world of UNIX and Linux, symbolic links are shortcuts, but they do not work like normal Windows shortcuts because you do not jump from one location to another with the file manager's address bar changing what it shows. Instead, it is as if you see the contents of the directory at another quicker to access location in the file system, and the same sort of thinking applies to files too. In some ways, it is like giving files and directories alternative aliases. There are soft links that point to the name of a given directory or file, and hard links that point to actual files or directories.

For a long time, I was under the mistaken impression that such things did not exist on Windows until I came across the mklink command, which came with the launch of Windows Vista at the start of 2007. While this feature might not be widely known, it demonstrates that Windows did adopt some UNIX and Linux capability long before other UNIX-like features, such as virtual desktops, were introduced in Windows 10.

By default, the aforementioned command sets up symbolic links to files and the /D switch allows the same to be done for directories too. The /H switch makes a hard link instead of a soft link, so we get much of the functionality of the ln command in UNIX and Linux. Here is an example that creates a soft symbolic link for a directory:

mklink /D shortcut target_directory

Above, shortcut is the name of the symbolic link file and target_directory is the destination to which it links. In my experience, it works best for destinations beyond your home folder and, from what I have read, hard links may not be possible across different disks either.

Windows commands for setting default applications for opening certain file types

On Friday, I was working on a system where a session is instantiated from a stored virtual machine that produces a fresh session every time, meaning that all previous changes get lost. What I have is a batch script that I run to reinstate what I need, and I encountered another task that I wanted it to do.

Part of my work involves the creation of plain text files with the extension lst and this is getting associated with SAS instead of Notepad. While you can reassign such associations using the GUI, it would be a bonus to do it via the command line too, so the assoc and ftype commands caught my interest. The first of these associates a file with a given extension with a desired file type, while the second shows the available file types together with the associated applications that open them. The assoc command also shows all the associations that are in place when it is executed with no parameters, and the ftype command does the same for file types.

Once you have picked out a file type with the ftype command, then the assoc can be used like the following:

assoc .lst=txtfile

The above associates an extension with a file type. In this, .lst files are going to get opened by Notepad because of the txtfile association. Though it did not do what I wanted on Friday due to system lockdown, it is good to know that this is possible and that even the Windows command line supports goodies like these.