Drag and Drop into a GLUT window

Does anyone have any tips on how to wrap a Drag and Drop
or Cut and Paste interface around a GLUT app for linux
(and OSX as well)? I’ve pulled it off in Windows by
subclassing the GLUT window to convert WM_COPYDATA and
WM_DROPFILES messages into Ctrl-V keystrokes which make
it past the GLUT message filter and into the keyboard
handler function. I feel somewhat guilty that I’m unable
to do the same sort of thing for non-Windows users.

Any ideas?