in reply to What Perl CAN'T do?
Perl is like painting a masterpiece with a thick brush. Everything can be done! And if you are skillful you could get extraordinary results.
What is most important in perl is what brother Merlyn always mentions: the luck of counting with universal readymade-experience that you can always achieve just by downloading one of CPAN's modules. Thanks to this, you don't need to be an expert in networks (for example) to program about such subject. You only need to trust that the modules work as expected.
Years ago, when programing in Assembler, I used to build my own libraries to simplify the job. Then I thought that giving those libraries the same names as perl commands, I would have had my own perl version. Now, if you have such assembly libraries managed by perl, you would be able to program in assembly with perl. So, you would be able to do anything with perl!
I mean, how close to the machine do you need to be to program certain job? That is the real question.