netbuzz writes: "Whether you prefer to call it “the duct tape of the Internet,” “the Swiss Army chainsaw,” or just its given name, the Perl programming language turns 25 today. Perl 1.0 was released by its creator Larry Wall on Dec. 18, 1987."
egrep patterns are full regular expressions; it uses a fast deterministic
algorithm that sometimes needs exponential space.
-- unix manuals