Clipboard (computing)

In many GUI computing environments, the clipboard is used to refer to a portion of memory which is accessed via copy and paste operations. It is an anonymous, temporary block of memory that can be accessed from most or all programs within the environment.

In newer versions of the Microsoft Windows operating system, the contents of the clipboard can be viewed at any time by using the ClipBook Viewer application (clipbrd.exe). (In older versions of MS Windows the common practice was to open a copy of the "Notepad" or "Wordpad" editor, and paste thereto). The keys which copy into the clipboard are: [Ctrl]+[Insert] while cutting into the clipboard is accomplished with [Shift]+[Delete] and [Shift]+[Insert] is to "paste" (copy contents from the clipboard into the current application window or dialog entry field). Often these operations are available from the "Edit" pull down menu and/or they may be available via a pop-up menu, usually accessible by "right clicking" in the window or dialog entry that is to be cut from or pasted into.

Many MS Windows applications also provide MacOS compatible keybindings.

In the Macintosh Operating System the contents can be viewed by choosing the menu option [Edit] > [Show Clipboard]. MacOS conventional keybindings include [Ctrl]+[v] to paste data from the clipboard, and and [Ctrl]+[x] to cut into it. (MacOS users commonly use the key sequence [Ctrl]+[x], [Ctrl]+[v] to "copy" into the clipboard, by cutting and immediately pasting one copy. The data is still available for further copying into other windows).

In the X Window System (the Graphical user interface commonly used on Unix and Linux systems, the conventional use of the clipboard is accomplished by highlighting text in any window, and using the "middle" mouse button to paste it into the target. However, there is great diversity among X applications, toolkits and libraries. Thus the GNOME and KDE environments provide closer analogs to the MS Windows clipboard semantics, and applications like Mozilla also provide their own.

The detailed semantics of the "clipboard" vary from one operating system to another, and also change over time and may be subject to some user preferences settings. This can lead to some degree of user frustration when one becomes accustomed to one set of behaviors and encounters differences on new versions or new platforms.

For example, most environments have traditionally held only one transaction. Each cut or copy over-writes the previous contents. Normally paste operations copy the contents ... leaving the contents available in the clipboard for further pasting operations.

Another difference that users may encounter: data was traditionally sorted as plain text with no information about font, typeface, type style, color or other characteristics of the data. However, some applications in some environments implement more sophisticated storage.

For example cutting a range of cells in a spreadsheet and then pasting them into another sheet or area of the same sheet may preserve all of the underlying formulae and data ... and may even translate intra-cell references (such that a "SUM(...)" calculation on a sub-range of the cells is converted to refer to the newly pasted copies of those cells.

Other examples of this sort of meta-data preservation occur when pasting among web browsers (where the underlying HTML may be stored in the clipboard) or in mail user agents (such as Microsoft's Outlook which uses Rich Text Format).

Usually when such complex data is pasted into a simpler application, such as a text editor, the data is then converted into its plain text representation. Thus cutting and pasting into a copy of "Notepad" is a common way for users to convert small selections of data into plain text for various purposes.

Some environments, particularly newer and more sophisticated ones, provide some sort of Clipboard manager with "multi-clip" features. In this model the clipboard is usually treated as a stack or scrap book, with new cuts and copies being placed "on top" and normal paste operations copying from the top. These generally also provide some means to open a window and selection from earlier data selections, and some provide editing, re-formatting, and searching capabilities.

Most environments do not save the clipboard contents to any persistent storage. Thus when a user logs out or reboots his or her system the clipboard contents are cleared and forgotten.

Standard clipboard keyboard shortcuts

In MS Windows
- Cut - Ctrl+x or Shift+Delete
- Paste - Ctrl+v or Shift+Insert
- Copy - Ctrl+c or Ctrl+Insert (In many other systems Ctrl+c is used for killing the running process)

In MacOS
- Cut - Ctrl+x
- Paste - Ctrl+v
- Copy - Ctrl+x Ctrl+v

External links