changeroot

#!/bin/bash

MOUNTS=(/proc /sys /dev /dev/pts)

if [ -n "$1" ]; then
  for f in "${MOUNTS[@]}"; do
    mount --bind $f "$1$f"
  done
fi

chroot "$@" || exit $?

if [ -n "$1" ]; then
  for ((i=${#MOUNTS[@]}-1; i>=0; i--)); do
    umount "$1${MOUNTS[$i]}"
  done
fi