Regardless of whether you use Linux, macOS, or Windows, the clipboard is one of the most frequently used tools on the desktop. It is a buffer provided by the operating system that temporarily stores, for instance, text snippets which can then be copied and pasted into other applications.

The various desktop environments often have clipboard managers that extend the possibilities of the clipboard. In contrast to the operating system's own clipboard, which resides in RAM and whose contents thus disappear at the next reboot, these small tools help preserve a configurable number of texts beyond a reboot. In KDE Plasma, the corresponding application is known as Klipper, which is loosely derived from the clipboard.

You populate the clipboard by pressing Ctrl+X, Ctrl+C, or by selecting something with the mouse and calling the corresponding item from the context menu. Applications such as screenshot tools or password managers also have a menu item for saving recordings or passwords in Klipper.

In the settings, you specify whether Klipper starts with a blank memory for security reasons or continues to keep the previous contents across sessions. In addition, actions can be specified with saved text sections, such as automatic pasting or including regular expression-based pastebins.

Even though Klipper and its ilk already extend the clipboard's capabilities considerably, there's still far more that can be done. CopyQ [1], an open source clipboard management tool that was first released in 2009, offers a multi-platform solution. Furthermore, CopyQ is the only clipboard manager I know of that stores and displays images in addition to text and rich text (RTF) (Figure 1). Competitors such as Klipper or GPaste only keep references to images and cannot display them.

Figure 1: As a unique selling point, CopyQ lets you display saved images instead of just saving a reference to them.

CopyQ is not only available for Linux but also for Windows and macOS, so you don't have to change horses just because you use different operating systems. CopyQ can be installed from the archive of most Linux distributions and is currently available in version 6.0.1. If the distribution you are using installs the suggested packages ("recommends") with the program, you just need to set up the copyq package; otherwise you also need copyq-plugins.

Long-Term Memory

After installing CopyQ, your computer's new long-term memory is immediately ready for use. It will automatically adopt all clipboard content in the future. If you want to stop this temporarily, switch off the feature in the main menu below File | Disable Clipboard Storing or by Ctrl+Shift+X. You can achieve the same effect with the commands copyq disable and copyq enable in a terminal window.

Using the basic functions turns out to be self-explanatory, while the learning curve is a little steeper for the advanced functions. After checking out the very extensive setting options (Figure 2), you will certainly appreciate some detailed documentation [2].

Figure 2: The existing default settings turn out to be self-explanatory, but some of the advanced features might require studying the detailed documentation.

Regarding everyday operations. CopyQ sits in the system panel with an icon featuring a pair of scissors with green handles. Clicking on the icon opens CopyQ's main window, which you can alternatively access at the command line with the copyq toogle command.

Right-clicking on the icon (or using the copyq menu command) brings up a context menu, as expected; it displays the last five saved entries in the upper area by default and offers access to the settings below, among other things. Invoked in this way, there is also a search bar in focus at the top of the window that you type into directly. The copyq help command shows all commands that CopyQ supports at the command line.

Copy & Paste

By far the most common use case in everyday life is copying and pasting content. If you need recent entries, you can do this in the main window or the context menu, which, as mentioned, displays the last five entries. This number can easily be increased to 10, for example. However, it does not make sense to use more than 10 entries for sake of a better overview. The main window is the better choice if you want more.

No matter which of the two windows you are using, after selecting the desired entry, a double-click beams it to the cursor position in the respective application. To do this, you first need to enable the Paste in current window entry in the settings below Progress. You can copy selected elements back to the clipboard by pressing the Enter key or Ctrl+C.

The Look

For a better overview with many stored entries you can create topic-related tabs. Under the Tabs menu, you define new tabs, rename existing ones, and delete those that are no longer needed. With the left arrow and right arrow keys you switch between tabs. For example, I use a daily tab that holds frequently used shortcuts for quick access. Themes also allow the appearance of the main window to be largely freely determined (Figure 3).

Figure 3: CopyQ comes with eight default themes for visual customization of the software. These can also be edited later.

But back to the entries themselves, which CopyQ refers to as elements: In the main window on the right side you will see a row of small icons that are used to manipulate the elements. If you mouse over them, a short label shows what they are used for. This ranges from manually creating an element to pinning elements to various predefined or self-created tags. Thus, elements can be activated for automated execution of commands, information about the file type of an element can be obtained, or elements can be removed if they are not pinned (Figure 4).

Figure 4: In the toolbar located on the right side of the main window(sporting the forest theme here), you will find the icons for editing the saved elements.