Advanced search and replace

I have a directory full of files that look like this: BWLIMIT=20971520000 DNS=[login to view URL] FEATURELIST=default IP=[login to view URL] MAXADDON=234 MAXFTP=100 OWNER=user PLAN=Professional RS=theme STARTDATE=1040066718 What I need in a script (perl or shell) to edit the files. For example if plan = Professional then: MAXADDON=0 MAXFTP=50 PARKED=2 In this case if the plan = professional then the three lines above would be replaced OR added if they are not there. Nothing else should be changed. If the plan does not = professional nothing should be changed. It would be best if there was an option to check for and make changes to several plans at one time but at times I may only need to make changes to one plan. Example: if plan = reseller do this: if plan = professional do this: if plan = advanced do this: if plan = standard do this: if plan = economy do this: A need a good coder that will delever a fully tested and working script. I don't have time to test your code so I need someone that can delever a bug free script the first time. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Exclusive and complete copyrights to all work purchased. (No GPL, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site). ## Platform Linux