write some shell script

I have an epos system which connects to multiple printers and cashdrawer the printer are from multipe manufacturers and use EPSON ESC/P our database get updated with the status of printing of order the the script should check database for any update and print or process action of cashdrawer port . the printers development document will be provided and we curently have this process developed in android environment and source code example can be provided the script will be called printing precess and will run in the centos system as a system process and if it failes will notify via email if database connectivity fails it needs to keep on trying until database connection is available if this faile also needs to send email every 5 min there is another part to this but can be done as seprate project we need to do network caller id on that linux centos system and when calls pickedup needs to update database of a caller id record only bid if you are expers shell script developer payment will only be made when fully working script is tested and approved . I am also open to solution on development