From convex to concave: reflections on decades of computer monitor usage
10th March 2025
Within the last week, I changed my monitor and am without an Iiyama in my possession for the first time since 1997. The first one was a 17" CRT screen that accompanied my transition from education into work. Those old screens were not long-lasting, though, especially since it replaced a 15" Dell screen that had started to work less well than I needed; the larger size was an added attraction after I saw someone with a 21" Iiyama at the university where I was pursuing a research degree.
Work saw me using a 21" Philips screen myself for a time before Eizo flat screen displays were given to us as part of a migration to Windows 2000. That inspired me to get a 17" Iiyama counterpart to what I had at work. Collecting that sent me on an errand to a courier's depot on the outskirts of Macclesfield. The same effort may have been accompanied by my dropping my passport, which I was using for identification. That thankfully was handed into the police, so I could get it back from them, even if I was resigned to needing a new one. More care has been taken since then to avoid a repeat.
The screen worked well, though I kept the old one as a backup for perhaps far too long. It took some years to pass before I eventually hauled it to the recycling centre; these days, I might try a nearby charity shop before setting off on such a schlep. In those times, LCD screens lasted so well that they could accumulate if you were not careful. The 17" Iiyama accompanied my migration from Windows to Linux and a period of successful and ill-fated PC upgrades, especially a run of poor luck in 2009.
2010 saw me change my place of work, and a 24" Iiyama was acquired just before then. Again, its predecessor was retained in case anything went awry and eventually went to a charity shop from where I could go into a new life. There was no issue with the new acquisition, and it went on to do nearly twelve years of work for me. A 34" Iiyama replaced it a few years ago, yet I wonder if that decision was the best. Apart from more than a decade of muck on the screen, nothing else was amiss. Even a major workstation upgrade in 2021 did little to challenge it. Even so, it too went to a charity shop searching for a new home.
This year's workstation overhaul did few favours to that 34" successor. While it was always sluggish to wake, it did nothing like going into a cycle of non-responsiveness that it had on numerous occasions in the last few months. Compatibility with a Mac Mini could be better, too. The result is that I am writing these words using a Philips B346C1 instead, and it has few of the issues that beset the Iiyama, save for needing to remove and insert an HDMI cable for a Mac Mini at times.
Screen responsiveness is a big improvement, especially when switching between machines using a KVMP switch. Wake up times are noticeably shorter, and there is much better reliability. However, it did take a deal of time to optimise its settings to my liking. The OSD may be more convenient than the Iiyama, yet having Windows software that did the same thing made configuration at lot easier. While getting acceptable output across Windows, Linux and macOS has been a challenge, there is a feeling that things are nearly there.
Another matter is the fact that this is a curved screen. In some ways, that is akin to the move from a 24" screen to a 34" one when fonts and other items needing enlarging for the bigger screen. After a burst of upheaval, eventually things do settle down and acclimatisation ensues. Even though further tinkering cannot be ruled out, there is a sounder base for computing after the changeover.
Possibly a retrograde way to keep an old scanner going on Linux Mint 22?
5th March 2025
For making a copy of a document for official purposes, I needed to get my scanner going with the new workstation. The device is an Epson Perfection 4490 Photo that I acquired in 2007 after its Canon predecessor, a CanoScan 5000F, began to malfunction. It has served me well since then, though digital photography has meant that scanning images is not something that I do frequently these days, the last time being in early 2022 to get larger images into my online photo gallery.
The age means that software support is an issue, more particularly for Windows 11. However, Linux can leave old devices behind it too. It does not help that there is little incentive for Epson to update its drivers either. Thus, Linux Mint's move from LIBSANE to LIBSANE1 makes things less straightforward when the Epson software needs the former.
While you can take apart a DEB file, re-edit its components before creating a new version, that sounds tricky to me. Nevertheless, it may be the way to go for others. Instead, I downloaded a DEB file for LIBSANE from Ubuntu and installed that instead. With that installed, the Epson software installed fully, allowing VueScan to work as I needed. Thus, the document got copied as I needed, and the rest then could happen as required.
When I went looking up solutions to my conundrum on Perplexity, it kept telling me that it was not the best way to go. However, I still took the chance, knowing that I could roll things back if needed. Computers never know you that well without a multitude of data, so the safety first approach has its merits, even if it can be overly cautious in some cases.
If I ever do need to replace the scanner, I probably would replace the printer with a multi-function device at the same time. The move would save some desk space, and I have had a good experience with such a device elsewhere. For now, though, such a move is on the long finger; securing a new freelance contract is higher up any to-do list.
Upheaval and miniaturisation
4th March 2025
The ongoing AI boom got me refreshing my computer assets. One was a hefty upgrade to my main workstation, still powered by Linux. Along the way, I learned a few lessons:
- Processing with LLM's only works on a graphics card when everything can remain within its onboard memory. It is all too easy to revert to system memory and CPU usage, given the amount of memory you get on consumer graphics cards. That applies even with the latest and greatest from Nvidia, when the main use case is for gaming. Things become prohibitively expensive when you go on from there.
- Even with water cooling, keeping a top of the range CPU cool and its fans running quietly remains a challenge, more so than when I last went for a major upgrade. It takes time for things to settle down.
- My Iiyama monitor now feels flaky with input from the latest technology. This is enough to make me look for a replacement, and it is waking up from dormancy that is the real issue. While it was always slow, plugging out from mains electricity and then back in again is a hack that is needed all too often.
- KVM switches may need upgrading to work with the latest graphical input. The monitor may have been a culprit with the problems that I was getting, yet things were smoother once I replaced the unit that I had been using with another that is more modern.
- AMD Ryzen 9 chips now have onboard graphics, a boon when things are not proceeding too well with a dedicated graphics card. Even though this was not the case when the last major upgrade happened, there were no issues like what I faced this time around.
- Having LED's on a motherboard to tell what might be stopping system startup is invaluable. This helped in July 2021 and averted confusion this time around as well. While only four of them were on offer, knowing which of CPU, DRAM, GPU or system boot needs attention is a big help.
- Optical drives are not needed any longer. Booting off a USB drive was enough to get Linux Mint installed, once I got the image loaded on there properly. Rufus got used, and I needed to select the low-level writing option before things proceeded as I had hoped.
Just like 2021, the 2025 upgrade cycle needed a few weeks for everything to settle down. The previous cycle was more challenging, and this was not just because of an accompanying heatwave. The latest one was not so bedevilled.
Given the above, one might be tempted to go for a less arduous path, like my acquisition of an iMac last year for another place that I own. After all, a Mac Mini packs in quite a lot of power, and it is not the only miniature option. Now that I have one, I have moved image processing off the workstation and onto it. The images are stored on the Linux machine and edited on the Mac, which has plenty of memory and storage of its own. There is also an M4 chip, so processing power is not lacking either.
It could have been used for work affairs, yet I acquired a Geekom A8 for just that. Though seeking work as I write this, my being an incorporated freelancer means that having a dedicated machine that uses my main monitor has its advantages. Virtualisation can allow drift from business affairs to business matters, that is not so easy when a separate machine is involved. There is no shortage of power either with an AMD Ryzen 9 8945HS and Radeon 780M Graphics on board. Add in 32 GB of memory and 2 TB of storage and all is commodious. It can be surprising what a small package can do.
The Iiyama's travails also pop up with these smaller machines, less so on the Geekom than with the Mac. The latter needs the HDMI cable to be removed and reinserted after a delay to sort out things. Maybe that new monitor may not be such an off the wall idea after all.
The Evoluent VerticalMouse 4 and Linux: a worthwhile ergonomic investment
3rd March 2025
For anyone spending long hours at a computer, wrist pain is an occupational hazard that tends to arrive slowly and outstay its welcome. The Evoluent VerticalMouse 4 has built a strong following among people looking to address that discomfort, its design placing the hand upright in a natural handshake position rather than forcing the palm flat against a desk. For Linux users, however, the out-of-the-box experience leaves something to be desired, and a few terminal commands are needed before the mouse behaves as it should.
The Ergonomic Case
The fundamental problem with a conventional mouse is that it holds the hand palm-down, a position that twists the forearm bones and places sustained tension on the wrist and median nerve. Used daily over years, this is a well-established route to RSI and, in more serious cases, carpal tunnel syndrome. The Evoluent addresses this by rotating the mouse through 90 degrees, so the hand rests on its side, eliminating that forearm twist. Terence Eden, writing about his experience with several generations of the device, notes that since adopting the vertical mouse range his wrists have been free of pain, and references an evaluation by a team of physical therapists, ergonomists and medical doctors at the University of California, Berkeley health services clinic, who found that the mouse promoted a neutral wrist and forearm posture.
The VM4R (the right-handed wired version) is the same fundamental shape as the earlier generation 3, but with a wider base and a larger lip along the lower edge to prevent the little finger from dragging on the desk surface. The pointer speed button, which on the generation 3 was located on the underside of the mouse (an awkward place to reach during use), has been moved to the top on the VM4R, where it can be operated without lifting or repositioning the hand. Two thumb buttons are included, a feature that is particularly useful for anyone whose index finger is suffering the effects of years of left-clicking. The chrome finish looks striking, though it does attract fingerprints.
What Linux Gets Right Out of the Box
The basic mouse functions work without any configuration on Linux, confirmed on Ubuntu 9.10 and higher. The cursor moves, the scroll wheel scrolls, and the pointer speed button changes the tracking speed as expected. The one immediate gap is that the scroll wheel click does not perform a middle-click paste, as Linux users might expect, and the additional buttons do not behave intuitively until they are remapped. Since Evoluent provides no Linux driver or configuration utility (their software is Windows-only), all customisation goes through the terminal.
Running xinput list will show the mouse in the list of input devices, typically appearing as:
"Evoluent VerticalMouse 4" id=8 [XExtensionPointer]Despite the mouse reporting 14 buttons, only 6 are physical buttons. The physical layout, as documented by Eden, is as follows: button 1 is the index finger (left click), button 2 is the ring finger (middle click), button 3 is the little finger (right click), buttons 4 and 5 are scroll up and scroll down respectively, button 8 is the upper thumb button, button 9 is the scroll wheel click and button 10 is the lower thumb button.
Remapping the Buttons: the Quick Method
The xinput{target="_blank"} tool allows button remapping in a single command. The following mapping, used by Eden himself, disables the index and ring fingers as direct clickers, makes the lower thumb button act as the primary left click, restores middle-click paste to the scroll wheel click, and sets the little finger as a right click:
xinput set-button-map "Evoluent VerticalMouse 4" 0 3 0 4 5 6 7 0 2 1 2The position of each number in the string corresponds to a button number, and the value at each position is the action that button will perform. Experiment with different values until the layout suits your workflow. This change takes effect immediately, but it is session-only: a reboot will reset the buttons to their defaults.
As MrEricSir notes in his guide to the mouse on Linux, the numeric device ID shown by xinput list will vary from one machine to the next and should not be relied upon in scripts. Using the full device name in quotes, as shown above, is the more reliable approach.
Making the Remapping Permanent: the Xorg Method
To make the button mapping survive a reboot, an Xorg configuration file is the recommended route. The first step is to identify the USB ID of the mouse by running lsusb and looking for the Evoluent entry in the output:
Bus 004 Device 004: ID 1a7c:0191 Evoluent VerticalMouse 4The portion you need is 1a7c:0191, though as MrEricSir points out, this will likely differ on your own system. With that value in hand, create the configuration file:
sudo nano /usr/share/X11/xorg.conf.d/90-evoluent.confPaste in the following block, substituting your own USB ID and preferred button mapping string:
Section "InputClass"
Identifier "Evoluent"
MatchUSBID "1a7c:0191"
Option "ButtonMapping" "0 3 0 4 5 6 7 0 2 1 2"
EndSectionNote that the button mapping string in this file does not begin with the device ID: that was only required for the xinput command. Save, close and reboot, and the mapping will be applied automatically on every subsequent login. The configuration file path above is confirmed to work on Ubuntu; on other distributions, the relevant directory may differ.
One known complication with the Xorg approach is that the USB ID can change if the mouse is plugged into a different USB port, as some systems enumerate devices differently by port. If the mapping stops working after a port change, running lsusb again will confirm whether the ID has changed, and the configuration file will need updating accordingly.
Making the Remapping Permanent: the Script Method
A commenter on Eden's post, Lukas, offers an alternative that sidesteps the USB ID problem entirely by extracting the device's current session ID dynamically at startup using grep:
xinput --set-button-map $(xinput list | grep -i "evoluent verticalmouse" | grep -o "id=[0-9]*" | grep -o '[0-9]*') 1 3 3 4 5 6 7 9 2 8 11 12 13 14This can be saved as a shell script, made executable with chmod +x, and added to the startup applications of your desktop environment. Because xinput needs the display server to be fully initialised before it can act, adding a sleep 5 line at the top of the script is advisable to prevent it from running too early on login.
A Note on the Scroll Wheel
One recurring theme in user reports is that the scroll wheel on the VM4R has a noticeably tactile, audible click with each scroll step. Eden remarks that he personally prefers a free-spinning wheel and found the VM4R's scroll noticeably stiffer than the generation 2 model. A separate user, James, describes a more persistent problem across three separate Evoluent mice: the scroll wheel intermittently loses stability, causing the page to jump unexpectedly rather than scrolling smoothly one step at a time. Eden's suggested remedy is to clean the wheel gently with isopropyl alcohol, as dust and debris can accumulate inside the mechanism over time.
Disabling the LED
The Evoluent logo on the mouse glows constantly during use. For those who find this distracting, particularly in a dark environment, there is a hardware method to disable it that does not require any software. Unplug the mouse, then hold down the negative (−) end of the pointer speed rocker button on the side of the mouse and plug it back in while keeping the button held. The logo light will remain off until the procedure is reversed by holding the positive (+) end of the same button during reconnection. This method is confirmed to work on later production units of the VM4R.
Using the Mouse on Wayland
The methods described above, xinput and Xorg configuration files, are specific to the X11 display server. Wayland is now the default on most major distributions, including Ubuntu and Fedora, and neither approach will work there. The situation under Wayland is, however, somewhat better than it first appears.
For basic use, several users have reported that the Evoluent VerticalMouse 4 works largely as expected under Wayland with no configuration at all, with button behaviour closer to what most users would want out of the box. If that is sufficient for your needs, nothing further is required.
For custom button remapping under Wayland, the modern approach documented by Olivier Mehani in a December 2024 guide uses the hwdb subsystem, which operates at the udev level below the display server entirely. This makes it display-server agnostic and avoids the need for any background daemons or services.
The first step is to identify the scan codes of the buttons you wish to remap. Install evtest and run it as root to observe raw input events from the mouse:
sudo evtestSelect the Evoluent device from the list and press each button you want to remap. The output will show a scan code value in the MSC_SCAN field for each button press. On the VM4R, the lower thumb button has scan code 90004 and the upper thumb button has scan code 90006.
Next, determine the key codes you wish to map those buttons to. The libinput tool can show key codes as you press them:
sudo libinput debug-events --device /dev/input/eventX --show-keycodesSubstitute the correct event device for your keyboard, which can be found by running libinput debug-events without a --device argument and looking for the keyboard in the list. With both the scan codes and the desired key codes identified, create a file in /etc/udev/hwdb.d/. The filename should end in .hwdb, for example 70-evoluent.hwdb. The following example remaps the two thumb buttons to the Shift key and the Super key respectively, as Mehani uses them:
evdev:name:Evoluent VerticalMouse 4:*
ID_INPUT_KEY=1
ID_INPUT_KEYBOARD=1
KEYBOARD_KEY_90004=leftshift
KEYBOARD_KEY_90006=leftmetaThe ID_INPUT_KEY and ID_INPUT_KEYBOARD lines mark the mouse as a device capable of generating key events, which is required for the remapping to take effect. Once the file is saved, rebuild and reload the hardware database:
sudo systemd-hwdb update
sudo udevadm triggerRestart your Wayland session and the new mappings will be active. The key names used in the file are lowercase versions of the Linux input event constants with the KEY_ prefix removed, so KEY_LEFTSHIFT becomes leftshift and KEY_LEFTMETA becomes leftmeta. Adjust the scan codes and key names to suit your own preferred layout.
Worth the Effort
The Evoluent VerticalMouse 4 is a well-considered device for anyone whose wrists are beginning to protest at years of conventional mouse use. For Linux users, the absence of any official configuration software is a genuine gap, but the community has documented reliable workarounds thoroughly. On X11, the xinput command and Xorg configuration files give you a permanent, flexible setup with minimal effort. On Wayland, Mehani's December 2024 guide demonstrates that the hwdb approach provides an equally robust solution that works at the kernel input level, independent of any display server. As Eden observes in his review, the lack of a good mouse configuration interface on Linux is a genuine oversight, but it is one that a little patience can overcome.
Displaying superscripted text in Hugo website content
6th January 2025
In a previous post, there was a discussion about displaying ordinal publishing dates with superscripted suffixes in Hugo and WordPress. Here, I go further with inserting superscripted text into Markdown content. Because of the default set up for the Goldmark Markdown renderer, it is not as simple as adding <sup>...</sup> constructs to your Markdown source file. That will generate a warning like this:
WARN Raw HTML omitted while rendering "[initial location of Markdown file]"; see https://gohugo.io/getting-started/configuration-markup/#rendererunsafe
You can suppress this warning by adding the following to your site configuration:
ignoreLogs = ['warning-goldmark-raw-html']
Because JavaScript can be added using HTML tags, there is an added security hazard that could be overlooked if you switch off the warning as suggested. Also, Goldmark does not interpret Markdown specifications of superscripting without an extension whose incorporation needs some familiarity with Go development.
That leaves using a Shortcode. These go into layouts/shortcodes under your theme area; the file containing mine got called super.html. The content is the following one-liner:
<sup>{{ .Get 0 | markdownify }}/sup>
This then is what is added to the Markdown content:
{{< super "th" >}}
What happens here is that the Shortcode picks up the content within the content within the quotes and encapsulates it with the HTML superscript tags to give the required result. This approach can be extended for subscripts and other similar ways of rendering text, too. All that is required is a use case, and the rest can be put in place.
Adding superscripts to ordinal publishing dates for entries in Hugo and WordPress
5th January 2025
These web publishing tools differ and so the solutions, yet the use case is the same: displaying ordinal dates for entries in a blog or website. Also, the wish is to have the ordinal suffix superscripted as in normal English usage. Let us take each platform in turn.
Hugo
Given that is programming in Go, it is little surprise that Hugo uses Go's time formatting syntax. Thus, my starting point was as follows:
{{ .Date.Format "15:04, January 2, 2006" }}
The result from the above looks like this: 20:56, January 2, 2025. Unfortunately, Go does not support ordinal dates in its time formatting, so adding them needs more extensive conditional logic like what you see below. The default suffix is th, while nd is added for the second and twenty-second days of the month and rd is added for the third and twenty-third days. This how things now look:
{{ .Date.Format "15:04, January 2" }}{{ if eq (.Date.Format "2") "2" }}nd{{ else if eq (.Date.Format "2") "22" }}nd{{ else if eq (.Date.Format "2") "1" }}st{{ else if eq (.Date.Format "2") "21" }}st{{ else if eq (.Date.Format "2") "3" }}rd{{ else if eq (.Date.Format "2") "23" }}rd{{ else }}th{{ end }}, {{ .Date.Format "2006" }}
That gives you something like 20:56, January 2nd, 2025. The handy thing about Hugo is that it primarily is an HTML output engine, so adding superscripting tags in the right places, like below, superscripts the ordinal suffixes as needed. Here, the tags are shown in bold for emphasis.
{{ .Date.Format "15:04, January 2" }}<sup>{{ if eq (.Date.Format "2") "2" }}nd{{ else if eq (.Date.Format "2") "22" }}nd{{ else if eq (.Date.Format "2") "1" }}st{{ else if eq (.Date.Format "2") "21" }}st{{ else if eq (.Date.Format "2") "3" }}rd{{ else if eq (.Date.Format "2") "23" }}rd{{ else }}th{{ end }}</sup>, {{ .Date.Format "2006" }}
Once you have that: this is how things appear: 20:56, January 2nd, 2025, which gets the job done.
WordPress
Hugo produces the website for you to upload it to the web server; it is static after that. In contrast, WordPress is based on PHP and dynamically renders a web page when it is requested. That means that components are generated at that time. Thus, the following code snippet outputs a date when a website post or page has been published:
<?php the_time('jS F Y') ?>
PHP time and date formatting does account for ordinal dates, unlike what you get in Go. Here, the jS F Y format controls how the date gets displayed. The codes do the following: j outputs the day in the month without a leading zero, S adds the ordinal suffix, F adds the full month name and Y adds the four digit year. The result then is something like this: 1st January 2025. To superscript the ordinal suffix, the following change is needed (the addition is emboldened for emphasis):
<?php the_time('j\<\s\u\p\>S\<\/\s\u\p\> F Y') ?>
Here, the HTML superscript tags are inserted into the format with every character escaped by a leading backslash (). While PHP does generate HTML, it needs the escaping to preserve the intended input here. Security considerations like preventing cross-site scripting also matter, though maybe not so much in this context. Regardless of the technicality, the result becomes 1st January 2025, which is what was sought.
Changing tab titles in the macOS Terminal app using the command line
25th December 2024
One thing that I have noticed with the macOS terminal app that I have not seen with its Linux counterparts is that the tab titles can get stuck after an SSH session to a remote server. Thus, I decided to see if they could be changed or reset. Handily, a single command will do just that:
echo -ne "\033]1;New Tab Title\007"
In a UNIX shell (BASH, ZSH, etc.), the echo command outputs text, and it is the text that changes a tab title. Here, the -ne options both negate the generation of a newline (which would be the function of the -n switch if used on its own) and interprets the escape characters included in the text (which would be the function of the -e switch if used on its own).
Within the text string \033 is the octal representation of the escape character that initiates the control sequence that follows it. This is ]1;, the Operating System Sequence (OSC) for setting the tab title in this case, more generally the icon and window title in other circumstances. The text New Tab Title should be self-explanatory, while \007 is the octal representation of the bell character (BEL) that terminates the OSC.
Because I wanted to have the current working directory path as the title, I made a small modification to do this dynamically:
echo -ne "\033]1;$(pwd)\007"
It is the $(pwd) portion that does just that, taking the output of the pwd command and adding it into the string. Thus, I see what is open in each tab. That stopped me ending up in the wrong one, and I even added an alias into the .zshrc file to make it easier to invoke. The functionality may be a more general UNIX or Linux feature, though I have not had opportunity or reason to try it just yet.
Getting Pylance to recognise locally installed packages in VSCode running on Linux Mint
17th December 2024
When using VSCode on Linux Mint, I noticed that it was not finding any Python package installed into my user area, as is my usual way of working. Thus, it was being highlighted as being missing when it was already there.
The solution was to navigate to File > Preferences > Settings and click on the Open Settings (JSON) icon in the top right-hand corner of the app to add something like the following snippet in there.
"python.analysis.extraPaths": [
"/home/[user]/.local/bin"
]
Once you have added your user account to the above, saving the file is the next step. Then, VSCode needs a restart to pick up the new location. After that, the false positives get eliminated.
What to do when the externally-managed environment error appears while using pip to install Python packages on Linux Mint 22
16th December 2024
After upgrading to Linux Mint 22, the following message appeared when attempting to install Python packages using the pip command:
error: externally-managed-environment
× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
python3-xyz, where xyz is the package you are trying to
install.
If you wish to install a non-Debian-packaged Python package,
create a virtual environment using python3 -m venv path/to/venv.
Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
sure you have python3-full installed.
If you wish to install a non-Debian packaged Python application,
it may be easiest to use pipx install xyz, which will manage a
virtual environment for you. Make sure you have pipx installed.
See /usr/share/doc/python3.12/README.venv for more information.
note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.
This will frustrate anyone following how-tos on the web, so users will need to know about it. On something like Linux Mint, the repositories may not be as up-to-date as PyPI, so picking up the very latest version has its advantages. Thus, I initially used the unrecommended --break-system-packages switch to get things going as before, since doing never broke anything before. While the way of working feels like an overkill in some ways, using pipx probably is the way forward as long as things work as I want them to do.
There is wisdom in using virtual environments too, especially when AI models are involved. For most of what I get to do, that may be getting too elaborate. Then, deleting or renaming the message file in /usr/lib/python3.12/EXTERNALLY-MANAGED is tempting if that gets around things, as retrograde as that probably is. After all, I never broke anything before this message started to appear, possibly since my interests are data related.
Something to try when you get a message like this caused by a filename with a leading hyphen: "mv: illegal option -- u"
3rd December 2024
Recently, I downloaded some WEBP files from Ideogram and attempted to move them to another folder. That is when I got the message that you see in the title of this entry. Because I had not looked at the filenames, I baffled when I got this from a simple command that I had been using with some success until then. Because I was using an iMac, I tried the suggestion of installing coreutils to get GNU mv and cp to see if that would help:
brew install coreutils
The above command gave me gmv and gcp for the GNU versions of mv and cp that comes with macOS. Trying gmv only got me the following message:
gmv: cannot combine --backup with --exchange, -n, or --update=none-fail
The ls command could list all files, but not the WEBP ones. Thus, I executed the following to show what I wanted:
ls | grep -i webp
That got around the problem by doing a subset of the directory listing. It was then that I spotted the leading hyphen. To avoid the problem tripping me up again, I renamed the offending file using this command:
mv -- -iunS9U4RFevWpaju6ArIQ.webp iunS9U4RFevWpaju6ArIQ.webp
Here, the -- switch tells the mv command not to look for any more options and only to expect filenames. When I tried enclosing the filename in quotes, I still got problems, even that might have because I was using double quotes instead of single quotes. Another option is to escape the leading hyphen like this:
mv ./-iunS9U4RFevWpaju6ArIQ.webp iunS9U4RFevWpaju6ArIQ.webp
Once the offending file was renamed, I could move the files to their final location. That could have used the -- option too, saving me an extra command, only for my wanting this not to trip me up again. Naturally, working in Finder might have avoided all this as much as not having a file with a leading hyphen in its name, but there would have been nothing to learn then.