The prompt line has two operating modes. In the normal mode, text is read-only. Messages appear on the prompt line to provide information and feedback in many commands. This is ``non-editing'' mode.
In non-editing mode, text can be selected by dragging with button 1 held down. Selected text is available for export to other windows, as the primary selection (see 3.13.3).
The prompt line can handle more text than is visible in the display area. If a string is longer than the display area, initially the rightmost part of the message string will be shown. Clicking in the prompt area with button 1 near the left border will show the start of the string. Clicking in the prompt area near the right border will show the end of the string. Clicking in the interior of the prompt area will show the middle part of the string, proportionate to click location.