SlackBuildsOrg/misc/xclip

Command line interface to the X11 Clipboard

xclip is a command line utility that is designed to run on any system
with an X11 implementation. It provides an interface to X selections
("the clipboard") from the command line. It can read data from standard
in or a file and place it in an X selection for pasting into other X
applications. xclip can also print an X selection to standard out, which
can then be redirected to a file or another program.