Commit check script: nproc does not exist on Darwin

I have it installed as part of homebrew - it's part of coreutils - so brew install coreutils would fix this.

OTOH if we are going to replace nproc here we should also replace it in the root composer.json

The suggested change does not work with ddev so will need some logic.

$ ddev ssh
$ vendor/bin/phpcs -ps --parallel=$(sysctl -n hw.logicalcpu) --standard=core/phpcs.xml.dist
sysctl: cannot stat /proc/sys/hw/logicalcpu: No such file or directory
............................................................    60 / 12877 (0%)

For both #5 and #6. Though not sure if it's fixed in #5 how that impacts #6

I think given #6 we're going to need tell mac users to do install something that makes nproc available. It looks like this could be an issue sometimes on linux too - https://www.howtodojo.com/nproc-command-not-found/

Then, lets add, at least, a comment to the script that nproc is needed and how to install it. Or, do an early check for it an output an nice message for the user.

Does this command print the expected output on machines without nproc?

$ nproc 2>/dev/null || sysctl -n hw.logicalcpu
8

On Linux with nproc this works as expected, if this also works on Mac then we can perhaps make it a bit more portable this way.

(This says: run nproc, but do not display errors, and if it fails, run sysctl instead)

I moved my nproc...

nproc 2>/dev/null || sysctl -n hw.logicalcpu
fish: Unknown command: nproc

So that doesn't look like that will work - it'll need to be something longer hand that checks for a commands existence first.

How about:

$ which nproc >/dev/null && nproc || sysctl -n hw.logicalcpu
8

although https://unix.stackexchange.com/questions/85249/why-not-use-which-what-to... implies this is not really solvable across all shells and operating systems.

I think we should consider doing command -v nproc && nproc || sysctl -n hw.logicalcpu - there no piping any error stuff. Works on Darwin and *nix. And we already use it via Symfony in our tests and other places - see usages of \Symfony\Component\Process\ExecutableFinder.

Ah we'll have to do command -q nproc && nproc || sysctl -n hw.logicalcpu ... -v will output stuff we don't want.

Testing...

$ command -q  nproc   && nproc || sysctl -n hw.logicalcpu
10
$ mv /opt/homebrew/bin/nproc /opt/homebrew/bin/nproc2
$ command -q  nproc   && nproc || sysctl -n hw.logicalcpu
10

Ho hum... command -q is a nicety from using fish shell...

So command -v nproc >/dev/null && nproc || sysctl -n hw.logicalcpu looks the best option. We're using a command we're already using and it'll work on Darwin and *nix and doesn't using niceties from fish shell...

#12 and #16 work in ddev.

Is there a reason not to 'hash' like tag.sh does?

if hash pbcopy 2>/dev/null; then
    echo "$notes" | pbcopy
    echo -e "\n** Your releases notes have been copied to the clipboard. **\n"
else
    echo "$notes"
fi

@quietone hash is definitely an option. Better than which... and about equal to command -v imo... prior art for both of them. hash seems to be a little quieter and concise. Tested
hash nproc 2>/dev/null && nproc || sysctl -n hw.logicalcpu
on fish and bash on Darwin without issue.

Yes, definitely quieter which I prefer.

We could always add a final fallback value of 1 right? So if both checks fail just use 1 thread.

#21++ that's a nice idea

So the final version should be something like

hash nproc 2>/dev/null && nproc || sysctl -n hw.logicalcpu 2>/dev/null || echo 1

Or maybe, a simpler idea is to compromise: assume everyone has either 4 or 8 threads/CPUs available, and just set a fixed value?

Or given the renewed interest in maintaining PHPCS, wait for them to automate it like PHPStan already has: https://github.com/PHPCSStandards/PHP_CodeSniffer/issues/10#issuecomment...

I prefer to get a change it quickly here so everyone has working script without having to install extra packages. I would go with '1' for now and if that turns out to be a problem it can be changed.

Let's not change it to only use 1 process - that'll slow builds down on gitlab

I'd do

hash nproc 2>/dev/null && nproc || echo 1

It's more concise and if people want quicker runs on darwin they can install coreutils. I've pushed to the MR to fix it this way.

#30 - my reasoning was because it is something else to maintain that is never run on any of our CIs so will be broken when something changes as inevitably it will.

And FWIW the command has to be hash nproc 2>/dev/null && nproc || hash sysctl 2>/dev/null && sysctl -n hw.logicalcpu 2>/dev/null || echo 1 because if we don't check for sysctl's existence then if a machine does not have nproc or systl it wouldn't echo the 1. You'd get an error about sysctl not existing.

Maybe we should echo something other than 1. There probably is now harm in going for 4 here as most PCs have at least these days. See https://store.steampowered.com/hwsurvey/cpus/

For me 2>/dev/null hides the "command not found" error if I deliberately change the command names, and falls back correctly because "command not found" has a non zero exit code:

hash nprocx 2>/dev/null && nproc || sysctlx -n hw.logicalcpu 2>/dev/null || echo fallback
fallback

Wonder if we can even just shorten it:

$ nprocx 2>/dev/null || sysctlx -n hw.logicalcpu 2>/dev/null || echo fallback
fallback

e.g.

nproc 2>/dev/null || sysctl -n hw.logicalcpu 2>/dev/null || echo 4

I know this doesn't work on the CLI in fish (via #11), but is fish actually used for the shell when run from the composer or commit-code-check script? (which specifies bash in the first line)

Or we could try:

bash -c "nproc 2>/dev/null || sysctl -n hw.logicalcpu 2>/dev/null || echo 4"

Or even:

bash -c "nproc || sysctl -n hw.logicalcpu || echo 4" 2>/dev/null 

There's a space between $( ( due to https://github.com/koalaman/shellcheck/wiki/SC1102

Tested this with ddev and still seems to work there just FYI.

Used this for about a day on a few tickets and at least for ddev I didn't hit any issues.

Committed and pushed to 11.x and 10.2.x, thanks!