1cp if1.c overunchanged.c 2ls -i overunchanged.c >overunchanged-before 3unifdef -DWEASEL=1 -ooverunchanged.c overunchanged.c 4e=$? 5ls -i overunchanged.c >overunchanged-after 6diff overunchanged-before overunchanged-after 7rm -f overunchanged-before overunchanged-after overunchanged.c 8exit $e 9