This command provides a Tcl interface to the Tk clipboard, which stores data for later retrieval using
the selection mechanism (via the -selectionCLIPBOARD option). In order to copy data into the clipboard,
clipboardclear must be called, followed by a sequence of one or more calls to clipboardappend. To
ensure that the clipboard is updated atomically, all appends should be completed before returning to the
event loop.
The first argument to clipboard determines the format of the rest of the arguments and the behavior of
the command. The following forms are currently supported:
clipboardappend ?-displayofwindow? ?-formatformat? ?-typetype? ?--? data
Appends data to the clipboard on window's display in the form given by type with the
representation given by format and claims ownership of the clipboard on window's display.
Type specifies the form in which the selection is to be returned (the desired “target” for
conversion, in ICCCM terminology), and should be an atom name such as STRING or FILE_NAME; see the
Inter-Client Communication Conventions Manual for complete details. Type defaults to STRING.
The format argument specifies the representation that should be used to transmit the selection to
the requester (the second column of Table 2 of the ICCCM), and defaults to STRING. If format is
STRING, the selection is transmitted as 8-bit ASCII characters. If format is ATOM, then the data
is divided into fields separated by white space; each field is converted to its atom value, and
the 32-bit atom value is transmitted instead of the atom name. For any other format, data is
divided into fields separated by white space and each field is converted to a 32-bit integer; an
array of integers is transmitted to the selection requester. Note that strings passed to
clipboardappend are concatenated before conversion, so the caller must take care to ensure
appropriate spacing across string boundaries. All items appended to the clipboard with the same
type must have the same format.
The format argument is needed only for compatibility with clipboard requesters that do not use Tk.
If the Tk toolkit is being used to retrieve the CLIPBOARD selection then the value is converted
back to a string at the requesting end, so format is irrelevant.
A -- argument may be specified to mark the end of options: the next argument will always be used
as data. This feature may be convenient if, for example, data starts with a -.
clipboardclear ?-displayofwindow?
Claims ownership of the clipboard on window's display and removes any previous contents. Window
defaults to “.”. Returns an empty string.
clipboardget ?-displayofwindow? ?-typetype?
Retrieve data from the clipboard on window's display. Window defaults to “.”. Type specifies the
form in which the data is to be returned and should be an atom name such as STRING or FILE_NAME.
Type defaults to STRING. This command is equivalent to “selectionget-selectionCLIPBOARD”.
Note that on modern X11 systems, the most useful type to retrieve for transferred strings is not
STRING, but rather UTF8_STRING.