The key is what level is your friend at right now. For example, a programming novice would require general programming knowledge. But, a programming expert who just doesn't know Perl wouldn't need that. Once the Camel book is read and understood, your friend will, most likely, know where to go from there. Remember - you're a resource, not a director.

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We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.