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Comment by dragontamer | Hacker News Reader

The Windows Clipboard, for all of its problems, remains one of the easiest program-to-program communication methods to use in modern GUIs.

I can take a screenshot of my Firefox with "PrtScn" button (moving a bitmap of the page into the Clipboard), paste it into Microsoft Paint, edit it a bit, and then copy/paste that into my Discord chat screen for commentary.

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Yes, Linux / *Nix users have pipes and great text processing tools. Yes, Powershell has interesting objects that can be passed round. But practically speaking? Most of my "inter-process communications" is over this silly "Clipboard" Windows has, and it works way better than it probably should.

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Even better, you can copy an attachment in a mail in Outlook, and paste it into an application running on another computer via RDP. The file will be copied over without the applications knowing any better.

We use this so users can attach invoices and other documents they've received through mail to orders in our application. Users typically run Outlook on their laptop/PC, but our application as a published application.

We rely on Excel exposing the data in an XML format on the clipboard to reliably import data from Excel. Same for Open/LibreOffice. Without it it's impossible to handle cells which contain both the quote character and newlines, due to the way Excel formats plaintext.

We don't want to import the whole file, because the users typically only need to import parts of the spreadsheet. This saves us from writing a complex UI to select the data to import.

And FWIW, I've used that with >100k rows of data.

Yea this is a super underrated feature - copy and paste through RDP is awesome. Although in some cases you would probably want to of course disable that for security reasons.

It works several layers deep too. My typical WFH scenario these days is:

    home PC -> 
    RDP to work laptop at home -> 
    VNC to work network -> 
    RDP to work desktop -> 
    RDP to other VMs and PCs at work

I can copy text or a file or a screen shot at any level and paste at any other level. Pretty amazing.

It's clipboards all the way down...

I've had the pleasure of looking at the Windows source code for the clipboard.

Insanely well engineered. It can perform miracles of computing. It damn well has to.

> I can take a screenshot of my Firefox with "PrtScn" button (moving a bitmap of the page into the Clipboard), paste it into Microsoft Paint, edit it a bit, and then copy/paste that into my Discord chat screen for commentary.

All without you worrying about supported image formats or color space encodings! It is insane! Copy from Firefox and then paste into a program that expects 16bit color and it'll probably work. The clipboard stores data in so many duplicate formats and can convert between so many formats, it is nuts.

I've found the clipboard to be a highly flexible tool, that seems under-used. As an example, I've extended my game engine editor to draw any position in 3d that I have in the clipboard. So when problems happen and are displayed in the logs, I select the log, copy to clipboard, boom, position drawn.

This idea has a lot of legs IMO.

There was a browser based game called "Utopia" in the 00s that was reasonably popular. Someone wrote a tool where you'd copy/paste your kingdom homescreen, and get all sorts of calculations / predictions.

It was one of the easiest-to-use calculators I've ever seen. Just enter your webpage to play the game, Ctrl-A (select-all), Ctrl-C (copy), and bam, the Utopia-program would instantly analyze your kingdom and provide advice.

Just all off of the HTML-copy that Clipboard supports.

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Windows developers "know" the clipboard is one of the most important inter-process communication structures of the entire system, and have known for years. Its probably one of the Win32 API's biggest advantages, no joke.

The shear amount of creative solutions I've seen from clipboard manipulations is outstanding.

Since Windows 7 or so, I've noticed more and more instances where you ctrl+C and the clipboard doesn't update. I had a chat with a Windows PM on it opportunistically a while back.

It turns out, more and more applications are locking the clipboard and holding onto the lock inappropriately. Enough that there's a particular telemetry watcher for this condition for MSFT to get an idea on who the guilty parties are.

Everyone has had it happen - I notice it when colleagues are in a rush and send me something they didn't mean to send (because their clipboard didn't update). I don't know who the guilty parties are (since that telemetry is encrypted, and can't be inspected), but I sure hope someone is knocking down some doors to address the problem.

Oooh so that's what that is. I've had it happen numerous times where I was absolutely sure I pressed CTRL+C yet the clipboard was empty. I now use CTRL+X and CTRL+Z just because of that.

That's interesting - that Ctrl+X behaves differently. It shouldn't right?

But you have found that it helps?

It helps because there is visual feedback so you're sure you don't have to go back to the original program and do the copy again. Plus sometimes your original program forgets your selection, with CTRL+X you're sure it's on the clipboard and won't have to return.

One guilty party: some versions of the RealVNC client randomly lock the clipboard.

Genuine question, why is it even possible to lock the clip board?

I have tried to track this down - it seems like at some point it was not possible. My guess is Vista is when the lock was implemented. I've come up blank repeatedly.

I am sure Raymond Chen knows. Looks like comments are allowed on his blog too!

An application doing a paste needs to query the available clipboard formats and then ask for the data from one of them. This wouldn't work reliably if other applications could simultaneously change the clipboard. So the OpenClipboard API locks the clipboard and applications need to remember to call CloseClipboard.

A weird one I've noticed with the clipboard on the Mac, is that the "rich text" clipboard and the "plain text" one seem to be able to get out of sync. This is most noticeable to me when trying to paste text into some dialog boxes in Microsoft Word.

This sounds to me like it's probably a proxy for the rise of GC languages. C#, which I reference because it's popular for windows desktop apps, has IDisposable and using() which helps a lot, but isn't mandatory. If you don't do something like this and there isn't memory pressure, there are low odds of a handle or resource lock being released.

Coming from the other side, most apps don't check the winapi error code when copying text. One app I use (notepad2 maybe?) at least throws up a tiny "Error" dialog box when it fails.

I configured my clipboard manager to make a crinkly paper noise when an app copies, so at least I have some feedback when it fails.

This must be a common issue because now that you say it I realized that I have a habit of always Ctrl-C'ing multiple times. Could also be the keyboard, most of mine had a glass of Coke at some point in time.

IIRC factorio's blueprints are represented, or have one representation, as base64-encoded gzipped JSON on the clipboard (with a version byte as prefix in the b64 form, double-IIRC), meaning you can copy/paste blueprints between the game and anything other that accepts text.

Hearthstone added something similar for decks (even made it human readable):

  ### Starting Party
  # 
  # Cariel Roame
  #   - Tome of Light 4
  # Xyrella
  #   - Robes of Purity 2
  # Rokara
  #   - Helm of Inspiration 1
  # Murky
  #   - Time to Krill 3
  # Millhouse Manastorm
  #   - Arcane Powder 1
  # Deathwing
  #   - Heart of Unliving 3
  # 
  CO+cmQQSDlN0YXJ0aW5nIFBhcnR5GAEiRQoJCBIQiwEYICAACgkIExDKARgjIAAKCQgLEIgBGAsgAAoLCLgCEOMCGLIEIAAKCAgOEB8YFCAACgsIqgIQygIYkgQgACgA
  # 
  # To use this deck, copy it to your clipboard and create a new deck in Hearthstone

I haven't been keeping up with the Windows world. Does Microsoft provide any safeguards or tools for the user to limit access to the clipboard? The clipboard was introduced in the good ol' days when you could basically trust the applications running on your computer. Nowadays, third party (and for those of us more paranoid) first party apps need to be considered attackers. The clipboard is a juicy target that often contains sensitive data I'm sure most apps would like to gobble up and exfiltrate. I know iOS and Android both are starting to introduce restrictions on mobile apps' use of the clipboard. Has this made it into the Windows desktop world?

Windows isn't sandboxed so any per-program restrictions is pretty much pointless because it'll be trivial to bypass.

Regular apps, Windows Store apps are sandboxed. Some of them are quite popular (eg: Netflix).

The rules are completely different if you're running "appstore" apps, which actually have some kind of sandbox.

If it's a regular win32 app, then it has access to all your filesystem (except UAC bits), can read and post keystrokes to other windows, and indeed can just straight up inject code into other processes.

Not true anymore - there are process isolation modes you can enable in Windows 10 as well as kernel isolation where it runs core processes in a VM essentially. And there is also protected folder access.

I've been wondering about this -- I'm making a text editor RPG, and in the medium term I want to make a file picker that builds a procedural dungeon based on your file system. I know such a thing would have been trivially fine in older versions of windows, but I didn't know if going down that road has any foot guns a more educated win developer would know.

Is protected folder access an on-by-default thing, or is it only certain folders?

Quick googling makes me think my plan might trigger windows defender for an exemption request. Hm That's a drag, but understandable I suppose?

You'd trigger Windows Defender's "Controlled Folder Access" only if the user has it on (it's still off by default IIRC due to many, many false positives) and only for write operations. By iterating every file you may trigger its "this might be ransomware" flag but you'll only be stopped when you try to write to a protected folder. (Which is only Documents, Pictures & Videos by default)

But honestly, I've had to whitelist Microsoft's own Windows utilities from CFA in its earlier days, so don't fret about it.

Thank you. I'm deliberately going to be readonly (and most likely only filenames unless the user requests contents) When I'm walking around the filesystem.

Thank you for the info.

Unrelated, but you can actually use Firefox's own screenshot function which is far more robust than PrtScn, allowing you crop the image how you want (including snap to element), you can also save to clipboard or download it for further editing or storing. The key-shortcut is CTRL+LSHIFT+S.

I find WIN + SHIFT + S to be superior, because it is not limited to the browser window, automatically copies to the clipboard, and you can choose to annotate it if you want

I mean, if you are in Windows already you should be using Snip at least since Win7. It has cropping, window snap, and basic annotation, in addition to capture save and copy.

It's cute just how old the concept of the Windows Clipboard is.

The basic APIs were there from the beginning in Windows 1.0, including multiple clipboard formats, application specific formats, and the ability to register for clipboard changes. More standard formats have been added over the years, but it still supports some ancient formats, like Software Arts' Data Interchange Format.

I recently looked at the API docs for Windows 1 because I wanted to see if ExitWindows was there from the start (since that naming really only makes sense if Windows has something to exit to). It wasn’t there until Windows 3, but I was surprised to see just how far back many familiar functions go. I expected the API to be far smaller than it was for 1.0

I'd love to get my hands on old Windows API docs. Are they available online somewhere?

Some are, here's the Win 1.0 and 2.0 SDK documentation:

https://www.os2museum.com/wp/windows-history/windows-library...

> "inter-process communications"

Way back in the 90s, it was possible to put any (+) document inside any sufficiently aware app or document with OLE ("object linking and embedding")

The (+) indicates that there were a lot of terms and conditions applying to this, but you could actually just put an excel spreadsheet in a word document, and it would run a small copy of excel inside word. This is why the original word save format is so horrendous - it's serialized binary objects.

I think OLE used the compound file format which was modeled after a FAT file system image.

https://en.wikipedia.org/wiki/Compound_File_Binary_Format

OLE is an awesome tech that I am sad isn't more widely used. The idea of being applications being portable toolboxes that can be embedded inside of other applications is just so cool. I remember embedding, IIRC, Print Shop Pro media inside of Word and when I clicked on the graphics the PSP UI appeared! Well after 10-20 seconds of hard drive thrashing it appeared, and then operated at about 5 fps.

Cool idea though!

What you describe also works on X11 and probably what MacOS uses too.

I'm not sure why it would be impressive or unusual. The ability to store arbitrary data on the clipboard with metadata that describes what data it is, such as an image file, or an audio file, is very old.

> What you describe also works on X11 and probably what MacOS uses too.

Except its no where near as smooth or universal as in Windows. In Linux, you have to worry about KDE programs vs GNOME programs having different clipboards, for example.

Its also why compatible suites of programs (ie: Adobe) can be so useful when those custom formats come into play. Adobe can copy/paste layers from Photoshop and send them over to other programs. If the photoshop layer isn't understood, it seems to become a Bitmap, which works when I'm on a VBulletin forum over in Firefox land.

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Copy/paste works on files / file-managers, images, text, HTML. Yes, any OS could do the same thing, but they largely don't in my experience.

The conversion behavior you describe is also what happens in MacOS.

>In Linux, you have to worry about KDE programs vs GNOME programs having different clipboards, for example.

I don't worry about this on linux because it's not the case.

I suppose if I were on windows I would have to worry about legacy programs that only understand UCS-2 not being able to talk to modern programs that only understand UTF-8.

>Its also why compatible suites of programs (ie: Adobe) can be so useful when those custom formats come into play. Adobe can copy/paste layers from Photoshop and send them over to other programs. If the photoshop layer isn't understood, it seems to become a Bitmap, which works when I'm on a VBulletin forum over in Firefox land.

I'm able to paste images from GIMP, Krita, and Thunar into forums just fine.

MacOS clipboard is also pretty good, I'm often pleasantly surprised by it. I don't use Windows enough in the right ways to compare them, I wouldn't be shocked if Windows is even better.

But even if old, it's still notable that such an old concept/technology works so well, and there are few newer inter-process communication methods that work as reliably or with as good UX!

Who invented the "clipboard", Xerox PARC? No, wikipedia just credits two individuals, Pentti Kanerva and Larry Tesler .

They're about equal, MacOS generally is better about letting my copy a thing in one application and paste the whole object in another. Windows however has RDP, which I've used as a file transfer mechanism by base64 encoding files, I thought about writing software that would use it as a half duplex communications channel.

Mac also has something that lets you copy/paste clipboard across machines (including between iOS and MacOS), but I don't know how it works technically and haven't actually used it myself.

https://support.apple.com/guide/mac-help/copy-and-paste-betw...

Nah man, clipboard on Linux, mainly KDE, is really good. KDE splits out selected text, and ctrl+c text, into separate clipboards, allowing for some really good workflows.

Selecting text and middle clicking is so much faster than ctrl+c, ctrl+v. Having the two separate, allows you to essentially copy two separate things at once, and paste them separately, which is great for filling out forms.

Also, KDE provides an absolute gem of a clipboard manager, which stores all recent copies in to a list, from which entries can be browsed in order to recopy some text that you may have copied a while ago. IDK where you got the idea that Gnome apps have a different clipboard, as I have never experienced that. Maybe that is an old thing? Definitely not how it is now, thats for sure.

Copy/paste works on files / file-managers, images, text and HTML. This is not a Windows only experience. In fact, the clipboard manager even has little file icons, and image previews, for copied objects.

> Also, KDE provides an absolute gem of a clipboard manager, which stores all recent copies in to a list

In windows 10 and up, win + v to see (and the first time, enable) the clipboard history selector

Yes I love this Windows 10 feature.

Note that KDE has had it pre Windows 10 though.

> KDE splits out selected text, and ctrl+c text, into separate clipboards, allowing for some really good workflows.

Just for completeness & correctness: that's an X11 feature, not related to KDE, and predates KDE by several years. I can't easily find the history of it, but this Keith Packard paper[0] on it is dated 1990 so it's necessarily older than that…

[0] http://keithp.com/~keithp/talks/selection.ps

(pg. 5, "4.1. Selection names" - PRIMARY, SECONDARY, CLIPBOARD. I don't think SECONDARY is used much these days.)

> Except its no where near as smooth or universal as in Windows. In Linux, you have to worry about KDE programs vs GNOME programs having different clipboards, for example.

I am no sure where you get this idea. The clipboard is an X11 shared resource and any program taking control of it removes what any other had on it before.

> Its also why compatible suites of programs (ie: Adobe) can be so useful when those custom formats come into play. Adobe can copy/paste layers from Photoshop and send them over to other programs. If the photoshop layer isn't understood, it seems to become a Bitmap, which works when I'm on a VBulletin forum over in Firefox land.

The same exists on X11, programs can define custom metadata and define a hierarchy of different metadata and associated data on the clipboard and any application can decide for itself which formats it understands and which it does not.

I've personally built software that puts images on clipboards, and falls back with uris to that image if direct images not be supported by whatever reads it.

I love how when you copy something onto the clipboard, it silently and transparently outputs different things depending on where you paste.

For example, copying from Excel can output:

- to a table (when copied into word)

- to rich text when copied into Wordpad

- to plain text when copied into Notepad

- and even an image when copied into Paint.

All without having to select the desired type at the source.

I believe Windows did a lot of things right by just keeping things simple for developers. I use the clipboard to transfer large blobs of data from one program to another when doing exploratory programming -- it's a lot quicker than creating file formats for everything. Of course there's the risk of losing it in the process.

Another under-appreciated Windows feature is how they implement drag-and-drop apps. When you drag a file into an app icon, it just stuffs the file path into the command line arguments and runs the app. In contrast, though MacOS introduced drag-and-drop, actually implementing it in System 7 was a huge complex chore.

On Windows, it's now faster/easier to use the built in Snip+Sketch tool (Win + Shift + S).

It does instant rectangular selection, then pops up a simple editor which you can then copy/paste anywhere you'd like.

I have Win+Shift+S bound to a mouse chord, as well as copy and paste, so I can actually paste an arbitrary rectangle of my screen without touching the keyboard.

I do this exact same thing on linux without any issues. I use a presetup desktop environment, it's fine.

If I used arch or some other power user linux, I suspect I would have to jump through quite a few hoops to get this experience setup as nicely. But as someone who daily drives both a linux distribution and a windows distribution, I see no notable differences in clipboard functionality.

Also really handy sometimes is Win+PrintScreen, which puts the screen image on the clipboard, and also saves it to a numbered file in your Pictures\Screenshots folder. If things are happening fast and you don't want to paste and manipulate each screen shot, this lets you save several in a row to go back and work with later.

For screenshots and edits, I have to say that I love MacOS's tools. CMD-Shift-4 to capture a screen region, click on it in the bottom right, edit it right there, and click 'Done'. Their editing tools are also super intuitive there. Honestly my favorite MacOS tool and I'd love a cross platform equivalent.

FWIW the process is about the same in Windows. The only difference is the keyboard shortcut is Windows-Shift-S.

The only real difference is that Windows introduced the simple way only fairly recently (7 years ago with Windows 10), so lots of people are still used to doing it the old way.

On the current macOS, the screenshot can be edited/annotated when it's previewed on the mac or on a nearby iPad where it automagically appears (with edits propagating back to the mac).

Something similar is available in the more modern Windows 'snipping tool' feature (win-shift-s) but without the tablet magic.

It's also great when you copy some text from Outlook and it pastes it into discord as an image of the text. I believe it has been fixed now but that was happening to me for a while.

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