In addition to getting the book, get out on the web and get download other peoples monitoring programs. Go through them and pull out the bits you like. Perl is often used for monitoring things because it is quite easy to grab the output of a program and extract the useful information - when you know how.

Good luck and I recommend against trying to program in shell script - that was my first programming job and I'm glad it's over!

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Jeremy
I didn't believe in evil until I dated it.