> rename 's/\.c$/.x/' cumbersome?
Come on. s///? Backslash? $? Not one, but two single quotes?
One may as well type for i in *.c ; mv $i ${i/.c(#e)/.x} or
for i (*.c) { mv $i ${i%c}x }
I really would rather type ren *.c *.x. But then, I don't think in
perl.