"Efficient thumbnailing" programm isn't working on

I reciently installed gentoo-AMD64 on my machine,everything works well but the “efficent thumbnailing” programm which I downloaded from this forum and compiled by myself.
The programm is

$ file thumb
thumb: ELF 64-bit LSB executable, AMD6.9, dynamically linked (uses shared libs), stripped x86-64, version 1 (SYSV), for GNU/Linux 2.

My fvwm config is here:

SetEnv fvwm_icon_size 100
DestroyFunc FuncThumbnail
AddToFunc FuncThumbnail
+ I Raise
+ I SetEnv Icon-$[w.id] $[w.IconFile]
+ I ThisWindow (!Shaded, Iconifiable, !Iconic) PipeRead "$[fvwm_script]/thumb $[
w.id] $[fvwm_icon_size] /dev/shm/icon.tmp.$[w.id].png '$[w.IconFile]'"
+ I Iconify

DestroyFunc FuncDeThumbnail
AddToFunc FuncDeThumbnail
+ I PipeRead "echo WindowStyle Icon \\$\\[Icon-$[w.id]\\]"
+ I UnsetEnv Icon-$[w.id]
+ I Exec exec rm -f /dev/shm/icon.tmp.$[w.id].png
+ I Iconify

When I execute the program there is no error information.
sorry for my Engilish.
Thanks you in advance!

Well, where does this “thumb” program reside? According to your function, there’s some idiotic env var in use:


I assume it either resides in there, or you’ve changed the location as necessary? Note that there’s 1001 different ways of thumbnailing – all of which work differently. This was might be faster, but it might also be the code it uses doesn’t work well on your shiny new AMD64 machine.

Try one of the other ways.

– Thomas Adam

I have solved the problem, I modified the Makefile:
The original Makefile which I download from this forum:


and I modified the code to comport with my 64bit system:

Thanks you all the same