1# Rename $1 to $2 only if file content differs. Otherwise just delete $1. 2define mv-if-changed 3 if cmp -s $2 $1; then \ 4 rm -f $1; \ 5 else \ 6 $(cmd-echo-silent) ' UPD $2'; \ 7 mv $1 $2; \ 8 fi 9endef 10