I done lots of googling but I am still unsure on how to proceed.
What's the most common way of reading/write to the clipboard under Linux? I want both support for Gnome & KDE desktops.
Updated: do I take there isn't an easy solution and one must "aggregate" together multiple sources (gnome, kde) in order to craft a solution?
Maybe you can look at xclip and see how they have done it.
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.