[BioC] Running R without X11?

[Amy Johnson]

Hi, I'm trying to run batch R scripts that is triggered online with PHP code: 

exec(R --no-save -q < myscript.r > output.txt 2>&1);

However, as there are some R libraries, e.g. qvalue, webbioc needs X11 
(tcltk) loaded, I got the following errors:

Loading Tcl/Tk interface ... Error in dyn.load(file, DLLpath = DLLpath, ...) 
: 
  unable to load shared library 
'/usr/local/lib/R/library/tcltk/libs/tcltk.so':
  /usr/lib/libXft.so.2: undefined symbol: FT_GlyphSlot_Embolden
Error : .onLoad failed in 'loadNamespace' for 'tcltk'
Error: package/namespace load failed for 'tcltk'
Execution halted

I have no problem to run the script on the shell when X11 is lauched. How do 
I launch X11 before running R scripts in batch from the web? Is there a way 
to avoid loading tcltk when loading R libraries like qvalue and webbioc? As 
far as I remember, the old versions of qvalue and webbioc do not require 
tcltk.

Thanks

Amy.