Technology Tales

File comparison using PowerShell

In the past, I have compared files on the Linux/UNIX command line as well as the legacy Windows command line. Recently, I decided to try it using PowerShell. Here is the command structure:

Compare-Object (Get-Content ".\[name of one text file]") (Get-Content ".\[name of another text file]") > [path and name of output file]

Admittedly, this is more verbose than the others that I have mentioned above. Nevertheless, it does the job and sends everything to a text file for review. The Compare-Object piece does the comparison once the Get-Content portions have read in the content.

Accessing Julia REPL command history

In the BASH shell used on Linux and UNIX, the history command calls up a list of recent commands used and has many uses. There is a .bash_history file in the root of the user folder that logs and provides all this information, so there are times when you need to exclude some commands from there, but that is another story.

The Julia REPL environment works similarly to many operating system command line interfaces, so I wondered if there was a way to recall or refer to the history of commands issued. So far, I have not come across an equivalent to the BASH history command for the REPL itself, but there the command history is retained in a file like .bash_history. The location varies on different operating systems, though. On Linux, it is ~/.julia/logs/repl_history.jl while it is %USERPROFILE%\.julia\logs\repl_history.jl on Windows. While I tend to use scripts that I have written in VSCode rather than entering pieces of code in the REPL, the history retains its uses. Thus, I am sharing it here for others. In the past, the location changed, but these are the ones with Julia 1.8.2, the version that I have at the time of writing.

Quickly changing between virtual desktops in Windows 10

One of the benefits of running Linux is the availability of virtual desktops, and installing VirtuaWin was the only way to get the same functionality on Windows before the launch of Windows 10. For reasons known to Microsoft, they decided against the same sort of implementation as seen in Linux or UNIX. Instead, they put the virtual desktop functionality a click away and rather hides it from most users unless they know what clicking on the Task View button allows. The approach also made switching between desktops slower with a mouse. However, there are keyboard shortcuts that address this once multiple virtual desktops exist.

Using WIN + CTRL + LEFT or WIN + CTRL + RIGHT does this easily once you have mastered the action. Depending on your keyboard setup, WIN is the Windows, Super or Command key while CTRL is the Control key. Then, LEFT is the left arrow key and RIGHT is the right arrow key. For machines with smaller screens where multitasking causes clutter, virtual desktops are a godsend for organising how you work, and having quick key combinations for switching between them adds to their utility.

Keyboard shortcut for Euro currency symbol on Windows 10

Because I now have business dealings in Ireland, there is a need to add in the Euro currency symbol to emails even though I based in the U.K. and use U.K. keyboard settings. While there is the possibility to insert the symbol in Microsoft Office and other applications, using a simple keyboard shortcut is more efficient since it avoids multiple mouse clicks. For some reason, CTRL + SHIFT + E got into my head as the key combination, but that turns on the Track Changes facility in Word. Instead, CTRL + ALT + 4 does the needful and that is what I will be keeping in mind for future usage.

Smarter file renaming using PowerShell

It appears that the Rename-Item commandlet in PowerShell is a very useful tool when it comes to smarter renaming of files. Even text substitution is a possibility, and what follows is an example that takes the output of the Dir command for listing the files in a directory and replaces hyphens with underscores in each one.

Dir | Rename-Item –NewName { $_.name –replace “-“,”_” }

The result is that something like the-file.txt becomes the_file.txt. This behaviour is reminiscent of the rename command found on Linux and UNIX systems, where regular expressions can be used, like in the following example that has the same result as the above:

rename 's/-/_/g' *

In both cases, you do need to be careful as to what files are in a directory for this, though the wildcard syntax on Linux or UNIX will be more familiar to anyone who has worked with files via almost any command line. Another thing to watch in the UNIX world is that * parses the whole directory structure, and that could be something that is not wanted for much of the time.

All of this is a far cry from the capabilities of the ren or rename command used in the days of MS-DOS and what has become the legacy Windows command line. Apart from simple renaming, any attempt at tweaking a filename through substitution ended up with the extra string getting appended to filenames when I tried it. Thus, the PowerShell option looks better in comparison.

Turning off the full height editor option in WordPress 4.0

Though I casually follow WordPress development, it's not nearly as rigorous as when I submitted a patch that earned me a mention on a main WordPress release's contributor list. This may explain why I barely noticed the full editor setting, which is turned on by default.

WordPress has become so mature now that I almost do not expect major revisions like the overhauls received by the administration back-end in 2008. The second interface was got so right that it still is with us, even if there were concerns in my mind at the time as to how usable it would be. Sometimes, those initial suspicions can come to nothing.

However, WordPress 4.0 introduced a major editor change that I'm not sure is successful. A full-height editor sounds good in principle, but its implementation has rough edges that make me wonder if any UX person reviewed it. Scrolling becomes strange, with the editor's toolbar fixing in place when you scroll down far enough. The sidebar then scrolls out of sync with the editor box, creating an odd sensation. Keyboard shortcuts like CTRL + HOME and CTRL + END don't work properly, which convinced me this new arrangement wasn't for me and I wanted to disable it.

A Google search found nothing useful, so I tried the WordPress.org forum. This revealed I should have looked in the screen options dropdown box for "Expand the editor to match the window height" to deselect it. Because of a Visual Editor control there, I'd checked the user profile screen but found nothing, showing the setup logic is poor. Perhaps the Visual Editor option should be a screen option too. Thankfully, the window height editor setting only needs changing once for both posts and pages, covering all situations.

With a distraction-free editing option available, I'm not sure why someone added the full height editor too. If WordPress keeps this feature, it needs refinement to behave more conventionally. I wouldn't build a website with such ill-synchronised scrolling. This needs work, as does the Visual Editor setting location. Perhaps both settings should be at the user level, rather than having one above that level. Before finding the solution, I considered using distraction-free mode permanently and installed the WP Editor plugin. I kept the plugin for its code highlighting, even though entering code view always creates a new revision. Despite this issue, things are now better.

A look at Emacs

It's remarkable what work can bring your way in terms of technology. For me, (GNU) Emacs Has proved to be such a thing recently. It may have been around since 1975, long before my adventures in computing ever started, in fact, but I am asking myself why I never really have used it much. There are vague recollections of my being aware of its existence in the early days of my using UNIX over a decade ago. Was it a shortcut card with loads of seemingly esoteric keyboard shortcuts and commands that put me off it back then? The truth may have been that I got bedazzled with the world of Microsoft Windows instead, and so began a distraction that lingered until very recently. As unlikely as it looks now, Word and Office would have been part of the allure of what some consider as the dark side these days. O how OpenOffice.org and their ilk have changed that state of affairs...

The unfortunate part of the Emacs story might be that its innovations were never taken up as conventions by mainstream computing. If its counterparts elsewhere used the same keyboard shortcuts, it would feel like learning such an unfamiliar tool. Still, it's not as if there isn't logic behind it because it will work both in a terminal session (where I may have met it for the first time) and a desktop application GUI. The latter is the easier to learn, and the menus list equivalent keyboard shortcuts for many of their entries, too. For a fuller experience though, I can recommend the online manual, and you can buy it in paper form too if you prefer.

One thing that I discovered recently is that external factors can sour the impressions of a piece of software. For instance, I was using a UNIX session where the keyboard mapping wasn't optimal. There's nothing like an unfamiliar behaviour for throwing you off track because you feel that your usual habits are being obstructed. For instance, finding that a Backspace key is behaving like a Delete one is such an obstruction. It wasn't the fault of Emacs, and I have found that using Ctrl+K (C-k in the documentation) to delete whole lines is invaluable.

Apart from keyboard mapping niggles, Emacs has to be respected as a powerful piece of software in its own right. It may not have the syntax highlighting capabilities of some, like gedit or NEdit for instance, but I have a hunch that a spot of Lisp programming would address that need. What you get instead is support for version control systems like RCS or CVS, along with integration with GDB for debugging programs written in a number of languages. Then, there are features like file management, email handling, newsgroup browsing, a calendar and a calculator that make you wonder if they tried to turn a text editor into something like an operating system. With Google trying to use Chrome as the basis of one, it almost feels as is Emacs was ahead of its time, though that may have been more due to its needing to work within a UNIX shell in those far-off pre-GUI days. It really is saying something that it has stood the test of time when so much has fallen by the wayside. Like Vi, it looks as if the esteemable piece of software is showing no signs of going away just yet. Maybe it was well-designed in the beginning, and the thing certainly seems more than a text editor with its extras. Well, it has to offer a good reason for making its way into Linux too...

Adding workspaces to Windows

One of the nice things about working with Linux/UNIX is that you can organise your open applications so that they are open in different workspaces or virtual desktops. When I return to working on Windows, having everything open on the same desktop is something that I find less tidy. However, there is an open source application that adds virtual desktops to Windows and very useful it is too.

It is called VirtuaWin, and it adds an icon to the taskbar for switching between workspaces when it is running; there might be a bit of tweaking to be done for it to stay visible all the time, though. You can have it as a startup application in the same way that you have your security software, and I have been using it smoothly on both Windows XP and Windows 7 running in VirtualBox virtual machines. Insofar as I have seen it, you can have as many workspaces as you want and switching from one to another is achievable using keyboard shortcuts. Using CTRL, ALT and one of the arrow keys does it for me, but you can set up your own. All in all, it's a small download that brings a little sense of Windows desktop computing.

Useful keyboard shortcuts for managing the window sizes of Windows applications

Maximising and minimising windows is all part and parcel of using window-based user interfaces, so it's nice to know that there are keyboard shortcuts that reduce the need to use your mouse all the time. Here are a few that work on Windows:

Alt+Space+N   Minimise

Alt+Space+X   Maximise

Alt+Space+R   Restore (set to default)

Keyboard shortcuts for changing desktops in Ubuntu

I am more than a little surprised that I didn't encounter these earlier: Ctrl + Alt + Left Arrow Key moves left, and Ctrl + Alt + Right Arrow Key moves right through your Ubuntu desktops or workspaces. It's always handy to be able to save on mouse work while doing this sort, so these could prove useful. I wouldn't be at all surprised if they applied to other Linux distros too.