How to run a command or script after running apt-get command on a Debian or Ubuntu Linux

# This is a list of shell commands to run after invoking dpkg/apt-get #
DPkg::Post-Invoke {"command";};
DPkg::Post-Invoke {"/path/to/sbin/command";};
DPkg::Post-Invoke {"/path/to/script";};

# This is a list of shell commands to run before invoking dpkg/apt-get #
DPkg::Pre-Invoke {"command";};
DPkg::Pre-Invoke {"/path/to/sbin/command";};
DPkg::Pre-Invoke {"/path/to/script";};

   Pre-Invoke {"/bin/mount -o remount,rw /usr/";};
   Post-Invoke {"/bin/mount -o remount,ro /usr/";};

  Update
  {
     Pre-Invoke {"touch /var/lib/apt/pre-update-stamp"; };
     Post-Invoke {"touch /var/lib/apt/post-update-stamp"; };
  };

#!/bin/bash
# Name: /root/bin/php7helper
# Purpose: A shell script to patch php 7 fpm on Ubuntu serer
# Author: Vivek Gite <www.cyberciti.biz> under GPL version 2+
# ------
function update_php7(){
	local u="cyberciti"  # new user name
	local r="www-data"   # old user name
	local f="/usr/lib/tmpfiles.d/php7.0-fpm.conf" # config file
	local wrcmd="/etc/init.d/lighttpd restart"    # restart services
	local prcmd="/etc/init.d/php7.0-fpm restart"
	# patch it
	echo "$0: Patching $f..."
	sed -i "s/$r/$u/g" $f  
	# restart it
	$prcmd
	$wrcmd
}
# main #
update_php7

DPkg::Post-Invoke {"/root/bin/php7helper";};