I recently discovered this handy utility called xclip which is command line interface to X selections (clipboard) .
see xclip man page
uptime | xclip
Put your uptime in the X selection. Then middle click in an X application to paste.
xclip -loops 10 -verbose /etc/motd
Exit after /etc/motd (message of the day) has been pasted 10 times. Show how many selection requests (pastes) have been processed.
xclip -o > helloworld.c
Put the contents of the selection into a file.
Note: make sure you are using alias xclip=”xclip -selection c” otherwise you can’t just use to CTRL+v to paste it back in a different place.