Zip and UnZip a file programmatically in iOS?

Take a look at this SO questions.

And here is a library ziparchive

ziparchive An Objective C class for zip/unzip on iPhone and Mac OSX

Take a look at ZipKit also.

ZipKit is an Objective-C framework for reading and writing Zip archives in Mac OS X and iOS apps, it supports:

• the standard PKZip format
• files larger than 4GB in size using PKZip's zip64 extensions
• optionally, resource forks in a manner compatible with Mac OS X's Archive Utility (in the > Mac OS X targets only)
• clean interruption, so archiving can be cancelled by the invoking object (e.g., a NSOperation or NSThread).