I never knew it was a real thing. Always assumed it was some kind of legacy frozen and dead apis that systems keep insisting on saying they support "posix". Well TIL.
this post was submitted on 14 Jun 2024
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Any highlights from those in the know?
I care mostly about shell scripting, so I'm focusing on those bits. Via the HackerNews thread, mostly from a-french-anon:
Am too surprised that it is an evolving standard, so I was curious to read a little, then...
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What????
Is posix still relevant in any way?
Yes.
Why?
Because it's the foundation of a lot of cross-platform code, from the standard libraries in various programming languages to innumerable shell scripts.
Unless all the computing devices you use run Windows, you probably depend on POSIX, whether you have direct contact with it or not.
Shell scripts were a mistake. The weirdness you have to remember to safely stop executing when something fails is mind-boggling.
I'm so glad nushell exists and doesn't need any configuring to just do the reasonable thing and stop executing when something fails.
Shell scripts were a mistake.
I understand 1000% but I'm not sure I agree. With the peevishness of C and latent autism of assembly, something compiled or otherwise binary isn't always simple and straightforward. Sometimes, you have a task that only needs to be done three times, and just replaying the commands is sufficient.
sh, ash, and bash are all kinda dumb. Absolutely. But there are other shells that are significantly better. csh and zsh are both great. ksh has some history on it but is good too. But "shell scripts" don't have to be in your shell language. The hashbang line will let you make a command file and so long as you can describe the command line you can get most shells to run it. Be that language ~~line noise~~ perl or python or even go.
As a long time former ZSH user, I'll definitely include ZSH in shell languages to avoid for scripting.
The problem is simply the number of rules and incantations to slavishly include everywhere to make your script bail on error. set -e is not enough by far.
Python with plumbum or nushell are definitely better.
All you need to do is set -e at the start of the script to stop on a non-0 exit code. And quote variables to prevent globbing.
Oh you sweet summer child.
If you don't use pipes or command substitutions, set -e gets you a fair part of the way there.
If you're interested, I can look up the rest of the arcane incantations necessary.
Here's a neat tidbit. Using curl without -f --fail will make non-2xx status codes return success, so set -e won't help there.
Yeah, and that's just one of many many things to consider.
Shell scripts were a mistake. The weirdness you have to remember to safely stop executing when something fails is mind-boggling.
nushell scripts aren't shellscripts?
I usually write “POSIXy shell” but I thought that was clear from context this time.
The problem is that exit statuses !=0 aren't treated as error by default (with a way to turn that off for individual expressions). Instead you have to set multiple settings and avoid certain constructs in bash/ZSH/...
Everything that works like a modern programming language by default is fine of course