Programming Perl
Tom Christiansen, Jon Orwant, Larry Wall
From Amazon:
Adopted as the undisputed Perl bible soon after the first edition appeared in 1991, Programming Perl is still the go-to guide for this highly practical language. Perl began life as a super-fueled text processing utility, but quickly evolved into a general purpose programming language that’s helped hundreds of thousands of programmers, system administrators, and enthusiasts, like you, get your job done.
Every week, for over a year, Alessandro asked his friends, colleagues, and acquaintances that are part of his social networks (Twitter and LinkedIn) the following question:
"What is the book that changed your life? (not novels or religious texts)"
I think it's a wonderful way to connect in a less superficial way and learn a little more about each other. It's also a wonderful way to discover new books worth reading.
This is one of them. The full list is here.