It largely depends from whom you learn. Most people google and run with the first thing google throws up and perl has many, MANY (due to its age) really shitty learning resources. Even the most popular one, the book Learning Perl, has as of its 6th edition (2013), grave flaws and miseducates newbies severely.

Some comment from the position of someone familiar with Modern Perl, which is largely what's practiced on CPAN:

> shift() shifts @_ by default

This is discouraged, precisely because it messes with @_. It has valid uses, but people tend to make sure it's clear from the code why it's used. (Mainly in OO helper stuff.)

> <> iterates over @ARGV

Almost nobody uses that, precisely because it's very unreadable. It only exists for compatibility reasons and was made to serve people used to sed/awk.

> chomp chomps $_

I haven't seen code use chomp in ages. I've never used it myself.

> Messing with @INC changes library search paths, etc.

This is rarely used as well. Mainly only when doing release engineering. It's also most often done via `use lib 'whatever';`.

    push(@{$TV{$family}{kids}},"anotherkid");

That is an outdated way to write that. In a decent modern style it would be written like this:

    push @{ $TV{ $family }{kids} }, "anotherkid";

And with a more modern Perl, this:

    push $TV{ $family }{kids}, "anotherkid";