In addition to the primary selection, the X Window System provides a second similar facility known as the secondary selection. Nowadays, few X applications make use of the secondary selection, but you can access it using the following Emacs commands:
Set the secondary selection, with one end at the place where you press down the button, and the other end at the place where you release it (
mouse-set-secondary). The selected text is highlighted, using the
secondary-selection face, as you drag. The window scrolls automatically if you drag the mouse off the top or bottom of the window, just like
mouse-set-region (see Mouse Commands).
This command does not alter the kill ring.
Set one endpoint for the secondary selection (
M-mouse-3 to set the other end and complete the selection. This command cancels any existing secondary selection, when it starts a new one.
Set the secondary selection (
mouse-secondary-save-then-kill), with one end at the position you click
M-mouse-3, and the other at the position specified previously with
M-mouse-1. This also puts the selected text in the kill ring. A second
M-mouse-3 at the same place kills the text selected by the secondary selection just made.
Insert the secondary selection where you click, placing point at the end of the yanked text (
Double or triple clicking of
M-mouse-1 operates on words and lines, much like
mouse-yank-at-point is non-
M-mouse-2 yanks at point. Then it does not matter precisely where you click, or even which of the frame’s windows you click on. See Mouse Commands.