The real question is why does PHP have so many bugs that it's so trivial to exploit?
The last part makes the fact their could be massive security holes like RCE in the core language very worrying.
Going from php 4 to php 8 isn't even that painful and there are twenty years between. It's the one language where what you wrote 20 years ago probably still works today.
Upgrading a php application is one of the least expensive and uneventful things you can do. Try upgrading that java swing application or that react app that's 15 months old. Go, haskell, vue, python 2 to 3 are more difficult because of syntax changes where in php you have some breaking changes like globals being removed or ereg removal or mysql_ being removed. The changes were small like using mysqli instead of mysql or using preg instead of ereg.
There are literally companies stuck on PHP 7 because going to 8 is too painful. And honestly with my decade of experience your claim that going from 4 to 8 isn’t that painful sounds like nonsense and something you haven’t done. And the claim that php 4 code will work on php 8 is 100% nonsense. The syntax for how classes were defined in 4 is not supported in 8.
I’ve upgraded the code to the major versions of other languages without hassle. But they generally had fewer breaking changes in their major versions when I upgraded to Vue3 which was super painless.
And can you point to a minor upgrade where Go changed the syntax to the point the old one no longer works? With Go normally it's the tooling that changes. I can't remember the syntax changing on me. Especially since they have a Compatability Promise[1] it seems weird.
Just use rector
Minor point: classes are using the same syntax but you are right they typically won't work because the constructor have changed, in PHP4 it was a function named the same as the class, in PHP5 and on it's __construct, the PHP4 version was deprecated in PHP 7 and removed in PHP 8.0.
create_function is just gone. So is each(). Oh and HTTP_RAW_POST_DATA. The list is long.
If you have used == and in PHP4 we did that, come on, don't be holier than holy and claim you only used === in PHP4 then PHP8 will have some surprises for you.
In my experience rector became usable last year-ish, if you tried before, give it another whirl.
Usually due to frameworks. Those tend to do play fast and loose with language constructs so small changes can make them not work anymore. And as those same framework will also break a lot more things between version, you cannot easily upgrade them, so you cannot upgrade your php version.
Currently maintaining an internal symfony 1 website so I know the pain. At least the documentation of old symfony is still available unlike many more modern frameworks.
I know that they were still using the old code, just a year or so ago, on PHP 8.
EDIT: Was reminded of another site started in 2000 (start of PHP4) that is still running. I can only see the login page now, but I see the login page is still displaying a particular URL structure that was/is slightly uncommon. If they kept that but rewrote the entire thing internally... that would be odd, because it would be easier to rewrite the whole thing. I've no doubt they've upgraded some internal parts, if only to accomodate new business needs over the past 20+ years (I stopped working with this project in 2003?) but it's still up and running.
Now... that's also a problem in other languages too, but I've found it less so with something like... older Java. Because there are some things that are completely gone from earlier PHP, if people relied on those bits 15 years ago, there's potentially a lot of code touching that needs to happen.
My experience is there's less deprecation of language features in older languages (mostly thinking of Java). There were perhaps less 'wonky' ways of doing dynamic Java stuff in 2006, so 2006 Java will still work today. 2006 PHP can work today (see comments below), but the more 'advanced' your PHP was the more at-risk it will be when trying to upgrade to, say, PHP 8.x.
The other big thing, though, is frameworks. The more you tied your code to, say, ZF1, the bigger an upgrade effort will be (sometimes far bigger than expected). I've been hit by this a couple times in the last few years.
Should be noted that it stopped being the case close to a decade ago now. Since PHP 8 things have changed a lot and it's a significantly better platform, both in terms of usage and the people behind it.
PHP spent a long time running on fumes with little backing. It's now got huge financial backing from Jetbrains, Wordpress Symfony, Laravel etc and theres now people paid to work on it, which has dramaticly improved the quality and quantity of improvements, which are mostly focused around performance and bug fixes.
The performance gains arent just figures on paper either. There was a real world improvement of around 12% on PHP 8.3 alone.
(and all of them much improved over PHP IMO - especially XHP [equivalent to JSX, where HTML is a first-class citizen in the language syntax])
I really think that was a major misstep by the project.
Oh, yeah.
As someone who has written and maintained a lot of "infrastructure-level" stuff, I have come to learn that releasing a project that serves users, or is infrastructure for other projects, is like having children.
Making them is fun. Releasing them, is a pain, but, once they are out there, it is my Responsibility to support them, and accept that they have their own agency.
I can't just go in and pretend that I'm Lord Farquaad, and treat the project as if it's my private fiefdom. It's now a public resource, and my decisions and actions affect a lot of others. I also tend to write software that supports folks with a rather ... pithy ... demeanor, so screwups can result in not-pleasant feedback.
That's a big reason why I don't mind that most of my public repos aren't popular.
The breaking changes section of UPGRADING file for PHP 8.4 is over 200 lines. For 8.3 it was over 100 lines.
And when it went to version 8, there was only 1 full-time developer working on it and as far as I know 0 part-time. The rest were volunteers doing it as a hobby. That full-time developer who was paid by Jetbrains decided he wanted to work on another project. This resulted in the next release being pretty much nothing. At which point, everyone realised this language went from funded to not funded and they created the PHP foundation.
I'm also not seeing 200 on there, though you said "200 lines" are you talking about the length of the article, if so thats not really a helpful metric.
They changed error handling. That is a major impact. If things start throwing errors when they previously didn't it results in your app breaking because how you were handling errors is no longer applicable. Now you have third-party libraries, etc all breaking because the PHP core team can't be bothered to follow industry standards. And yes, SemVar is, at this point, the industry standard to the point people use 8.* in their composer require because they expect SemVar.
And changing error handling in very legacy areas of the code is the worst especially when there isn't even an RFC to say that they would be doing it. The fact it's legacy means people don't expect it to change.
> I'm also not seeing 200 on there, though you said "200 lines" are you talking about the length of the article, if so thats not really a helpful metric.
It's useful in giving an impression of the number of changes. Especially, when given an example of another release to see how they're increasing. And it's extremely useful when comparing to other languages where the breaking changes section either doesn't exist or it's extremely small. 200+ lines even with formatting and some lines taking two ends up with over 100 breaking changes.
I get it, you like PHP and you're protective over your tooling. I use PHP heavily, in fact, I'm building my business on top of it. But that does not remove my ability to look at how everything is compared to other languages and see there is a major problem. On Ubuntu, it has packages for each minor release whereas in Python it's just python3-*. Why? Because PHP's reputation for adding breaking changes whenever (despite the claim that they're really good at it) has been there for so long that even Linux distros know that people need to deal with that pain.
The problem with me being mainly a PHP developer is, I know all the problems. You can't BS me like you can devs who don't work with it so much.
Typically it is features before that causes problems.