You have to bare in mind Perls roots are as an awk-like language for the command line. In those instances weird line noise syntax was the idiom and as Perl grew it moved away from that but without breaking compatibility by default.

This leads to serious Perl projects relying on the numerous headers (as described in the very article we are discussing) to ensure everyone applies a more modern coding style.

So you can absolutely stop people from using $|

The point of Perl 7 is to have sane defaults.

Because perl improved over time, but they didn't want to break people's existing code needlessly.

No-one ever deliberately invents 'senseless' things, we just discover better ways over time. Sure, if we could somehow magically always invent the best way first of all, that would be great. But we can't, so we make the best of what we have, and improve when we can. But there's no need to punish the existing users of older, 'worse' things.

Whatever happened to the neophyte raising him/herself up to level of the master? Programming seems to be the only profession in which the beginner is excused learning the language thoroughly and, worse, that he/she expects the language to be dumbed down to make it easier to learn. Can you imagine a budding musician complaining that musical notation should be made "easier for beginners"? If you want to grok Perl learn Perl ... thoroughly.

If what you're saying is true, then why aren't similar criticisms raised against Ruby? Most of the same obscure variables are also present in Ruby.

"If hard-to-read-and-remember syntax exists, people WILL use it"

This statement doesn't appear to hold up under scrutiny.

> If hard-to-read-and-remember syntax exists, people WILL use it. And some people will make a POINT to use it, because it makes them feel cool.

Just like every human language that ever existed. And last time I checked, programming languages aren't used or written by AI's or aliens.

I take it you've never done much shell scripting? This part of perl's baggage comes from its roots as a "better" shell/awk/sed. I don't like it any more than you do, but I must say, I wish people would reserve some of the vitriol they have for perl for the shell. Because I gotta tell you Rabbi, perl is a hell of a lot better than shell scripts. And that's even if you compare perl4 (1991-1994 or so?) to the very latest bash or zsh.

edit:

BTW if $| is really at risk of clashing with a variable you defined... something else is wrong. :)

Compare that with the shell, where names like IFS can do unimaginable things if you don't know about them and set them by mistake. (Or maliciously; it's imported directly from the environment, and stuff like this is why shell scripts can basically never be given untrusted input, whereas perl, with the 'taint' option, can.)

Reflecting on all this it's pretty sad that newbies in 2020 are encouraged to learn bash, and continue creating arcane, unreadable, booby-trap-laden scripts in it, all the while looking down their nose at perl.

That's not so much Perl hijacking a user space variable as Perl having some single character globals that have special behavior. Really, you usually learn about those early (sorting is common), and if you're using strict like you should be, if you define them and use them they will work as expected until you use a custom sort, in which case you'll track down the error.

In Perl, you learn pretty early that single character non-alphanumeric variables ($|, $_, @_ $@) are special and if you encounter them and don't know them, look them up. You also learn that $1 through $9 and $a and $b have special uses, so don't use those without knowing what you're doing either.

> utterly confounding the first time one accidentally runs into it.

Yeah, but every language has some of those. Who remembers "Unexpected T_PAAMAYIM_NEKUDOTAYIM" in PHP? Or giant template error messages in C++? Or just plain segfaults? All paradigms and the languages within them have their own trade-offs and gotchas, and part of learning the language is learning those.