The second or third script I wrote in Perl was to "POP before email". It's changed over the years, but is still running on 10+ machines. I could not get one script to run on all *nix versions until I used the 'tell' function to save the location of the last successful read. What the book doesn't mention is that if the log file is smaller than the saved 'tell' location, you should start at the beginning of the file.
"Well done is better than well said." - Benjamin Franklin