I mean, come on... Perl is Turing Complete (standard boilerplate regarding assumptions about sufficient storage room, as Turing Machines, technically, have unlimitted memory), and thus can do anything that a Turing Machine is capable of.
Yeah, yeah, yeah. Modern day computers however, aren't Turing
Machines. We also want our programs to run fast (TM's, lacking
random access memory aren't fast) and to interface. Ever tried
reading the output of another program on a TM? Access a database from a TM? Play a DVD on a TM?
While a TM is useful in discussing the solvability of an
algoritmic problem, it's not very useful in discussing what
you can do with a language, as programs do far more than
reading predefined input from a tape and writing output to it.