post_install() {
if [ "$1" = 'configure' ] || [ "$1" = 'abort-upgrade' ] || [ "$1" = 'abort-deconfigure' ] || [ "$1" = 'abort-remove' ] || [ "pacman" = 'pacman' ]; then
  if [ -x "/data/data/com.termux/files/usr/bin/update-alternatives" ]; then
    # vi
    update-alternatives \
      --install "/data/data/com.termux/files/usr/bin/vi" "vi" "/data/data/com.termux/files/usr/libexec/busybox/vi" 10
    # editor
    update-alternatives \
      --install "/data/data/com.termux/files/usr/bin/editor" "editor" "/data/data/com.termux/files/usr/libexec/busybox/vi" 10
    # pager
    update-alternatives \
      --install "/data/data/com.termux/files/usr/bin/pager" "pager" "/data/data/com.termux/files/usr/libexec/busybox/less" 10
    # nc
    update-alternatives \
      --install "/data/data/com.termux/files/usr/bin/nc" "nc" "/data/data/com.termux/files/usr/libexec/busybox/nc" 10 \
      --slave "/data/data/com.termux/files/usr/bin/ncat" "ncat" "/data/data/com.termux/files/usr/libexec/busybox/nc" \
      --slave "/data/data/com.termux/files/usr/bin/netcat" "netcat" "/data/data/com.termux/files/usr/libexec/busybox/nc"
  fi
fi
}
pre_remove() {
if [ "$1" = 'remove' ] || [ "$1" != 'upgrade' ] || [ "pacman" = 'pacman' ]; then
  if [ -x "/data/data/com.termux/files/usr/bin/update-alternatives" ]; then
    update-alternatives --remove "vi" "/data/data/com.termux/files/usr/libexec/busybox/vi"
    update-alternatives --remove "editor" "/data/data/com.termux/files/usr/libexec/busybox/vi"
    update-alternatives --remove "pager" "/data/data/com.termux/files/usr/libexec/busybox/less"
    update-alternatives --remove "nc" "/data/data/com.termux/files/usr/libexec/busybox/nc"
  fi
fi
}
