Openwrt upgrade script

upgrade

#!/bin/sh /etc/rc.common

START=99
USE_PROCD=1

start_service() {
  if [ -e /root/.upgrade ]
    then exit
    else touch /root/.upgrade
  fi
  after_upgrade
  reboot
}

after_upgrade() {
  opkg update

  listold="$(cat /etc/pkgold.list)"
  list="$(opkg list-installed | cut -f1 -d ' ')"
  gsearch="\b$(echo $listold | sed -e 's/ /\\b\\\|\\b/g')\b"

  for i in $list
    do echo $i
  done | grep -v "$gsearch" |
  xargs opkg remove

  for i in $listold $list
    do echo $i
  done | grep "$gsearch" |
  sort |
  uniq -u |
  xargs opkg install
}

upgrade() {
  opkg list-installed | cut -f1 -d ' ' > /etc/pkgold.list
  cd /tmp
  wget http://downloads.openwrt.org/snapshots/targets/ar71xx/generic/openwrt-ar71xx-generic-archer-c7-v4-squashfs-sysupgrade.bin
  sysupgrade -c openwrt-ar71xx-generic-archer-c7-v4-squashfs-sysupgrade.bin
}