rename

#!/bin/bash -e
typeset -i i;
typeset -ig N=10000
for ((i = (N + 1) / 2 + 1; i <= N; i++)); do
  echo mv $((i)).pdf $((i))save.pdf
done
for ((i = 1; i <= (N + 1) / 2; i++)); do
  if ((i == (N + 1) / 2));then continue; fi
  echo mv $((i)).pdf $((N + 1 - i)).pdf
done
for ((i = (N + 1) / 2 + 1; i <= N; i++)); do
  echo mv $((i))save.pdf $((N + 1 - i)).pdf
done