Badabinski

God, can we not though? Haha funni meme and all, but like, I’m so tired of seeing this shit. It sucks for the women in the community, and honestly it sucks for the men too. It’s just such boomer humor.

Eh, I’m fine with man pages. I looked at tldr before, but I’ve been using the command line for many things almost exclusively for like 10+ years now. I usually just need the reference details.

Manpages are great though? They’re not the best if you need examples, but as a reference for the behavior of flags? I love’em.

I genuinely use vim inside of termux on a daily basis. I dunno if I’m sick in the head or what, but I kinda like vim on my phone.

I spend all day at work exploring the inside of the k8s sausage factory so I’m inured to the horrors and can fix basically anything that breaks. The way k8s handles ingress and service discovery makes it absolutely worth it to me. The fact that I can create an HTTPProxy and have external-dns automagically expose it via DNS is really nice. I never have to worry about port conflicts, and I can upgrade my shit whenever with no (or minimal) downtime, which is nice for smart home stuff. Most of what I run tends to be singleton statefulsets or single-leader deployments managed with leases, and I only do horizontal for minimal HA, not at all for perf. If something gives me more trouble running in HA than it does in singleton mode then it’s being run as a singleton.

k8s is a complex system with priorities that diverge from what is ideal for usage at home, but it can be really nice. There are certain things that just get their own VM (Home Assistant is a big one) because they don’t containerize/k8serize well though.

This is why I made the reference to Go. I honestly hate Go, I think exceptions are great and very ergonomic and I wish that language had not become so popular. However, a whole shitload of people apparently disagree, hence the popularity of Go and the acceptance of its (imo) terrible error handling. If developers don’t have a problem with it in Go, I don’t see why they’d have a problem with it in Bash. The error handling is identical to what I posted and the syntax is shockingly similar. You must unpack the return of a func in Go if you’re going to assign, but you’re totally free to just assign an err to _ in Go and be on your way, just like you can ignore errors in Bash. The objectively correct way to write Go is to handle every err that gets returned to you, either by doing something, or passing it up the stack (and possibly wrapping it). It’s a bunch of bubbling up. My scripts end up being that way too. It’s messy, but I’ve found it to be an incredibly reliable strategy. Plus, it’s really easy for me to grep for a log message and get the exact line where I encountered an issue.

This is all just my opinion. I think this is one of those things where the best option is to just agree to disagree. I will admit that it irritates me to see blanket statements saying “your script is bad if you don’t set -euo pipefail”, but I’d be totally fine if more people made a measured recommendation like you did. I likely will never use set -e, but if it gets the bills paid for people then that’s fine. I just think people need to be warned of the footguns.

EDIT: my autocorrect really wanted to fuck up this comment for some reason. Apologies if I have a dumb number of typos.

Yep. Bash was my first programming language so I have absolutely stepped on every single one of those goddamn pedblasters. I love it, but I also hate it, and I am still drawn to using it.

No worries! Bash was my first language, and I still unaccountably love it after 15 years. I hate it and say mean things about it, but I’m usually pleased when I get to write some serious Bash.

I personally don’t believe there’s a case for it in the scripts I write, but I’ve spent years building the || die habit to the point where I don’t even think about it as I’m writing. I’ll probably edit my post to be a little less absolute, now that I’m awake and have some caffeine in me.

One other benefit I forgot to mention to explicit error handling is that you get to actually log a useful error message. Being able to rg 'failed to scrozzle foo.* because service y was not available' and immediately find the exact line in the script that failed is so nice. It’s not quite a stack trace with line numbers, but it’s much nicer than what you have with bash by default or with set -e.

Lol, I love that someone made this. What if your input has newlines tho, gotta use that NUL terminator!

God, I wish more tools had nice NUL-separated output. Looking at you, jq. I dunno why this issue has been open for so long, but it hurts me. Like, they’ve gone back and forth on this so many times…

From https://mywiki.wooledge.org/BashFAQ/105

Once upon a time, a man with a dirty lab coat and long, uncombed hair showed up at the town police station, demanding to see the chief of police. “I’ve done it!” he exclaimed. “I’ve built the perfect criminal-catching robot!”

The police chief was skeptical, but decided that it might be worth the time to see what the man had invented. Also, he secretly thought, it might be a somewhat unwise move to completely alienate the mad scientist and his army of hunter robots.

So, the man explained to the police chief how his invention could tell the difference between a criminal and law-abiding citizen using a series of heuristics. “It’s especially good at spotting recently escaped prisoners!” he said. “Guaranteed non-lethal restraints!”

Frowning and increasingly skeptical, the police chief nevertheless allowed the man to demonstrate one robot for a week. They decided that the robot should patrol around the jail. Sure enough, there was a jailbreak a few days later, and an inmate digging up through the ground outside of the prison facility was grabbed by the robot and carried back inside the prison.

The surprised police chief allowed the robot to patrol a wider area. The next day, the chief received an angry call from the zookeeper. It seems the robot had cut through the bars of one of the animal cages, grabbed the animal, and delivered it to the prison.

The chief confronted the robot’s inventor, who asked what animal it was. “A zebra,” replied the police chief. The man slapped his head and exclaimed, “Curses! It was fooled by the black and white stripes! I shall have to recalibrate!” And so the man set about rewriting the robot’s code. Black and white stripes would indicate an escaped inmate UNLESS the inmate had more than two legs. Then it should be left alone.

The robot was redeployed with the updated code, and seemed to be operating well enough for a few days. Then on Saturday, a mob of children in soccer clothing, followed by their parents, descended on the police station. After the chaos subsided, the chief was told that the robot had absconded with the referee right in the middle of a soccer game.

Scowling, the chief reported this to the scientist, who performed a second calibration. Black and white stripes would indicate an escaped inmate UNLESS the inmate had more than two legs OR had a whistle on a necklace.

Despite the second calibration, the police chief declared that the robot would no longer be allowed to operate in his town. However, the news of the robot had spread, and requests from many larger cities were pouring in. The inventor made dozens more robots, and shipped them off to eager police stations around the nation. Every time a robot grabbed something that wasn’t an escaped inmate, the scientist was consulted, and the robot was recalibrated.

Unfortunately, the inventor was just one man, and he didn’t have the time or the resources to recalibrate EVERY robot whenever one of them went awry. The robot in Shangri-La was recalibrated not to grab a grave-digger working on a cold winter night while wearing a ski mask, and the robot in Xanadu was recalibrated not to capture a black and white television set that showed a movie about a prison break, and so on. But the robot in Xanadu would still grab grave-diggers with ski masks (which it turns out was not common due to Xanadu’s warmer climate), and the robot in Shangri-La was still a menace to old televisions (of which there were very few, the people of Shangri-La being on the average more wealthy than those of Xanadu).

So, after a few years, there were different revisions of the criminal-catching robot in most of the major cities. In some places, a clever criminal could avoid capture by wearing a whistle on a string around the neck. In others, one would be well-advised not to wear orange clothing in certain rural areas, no matter how close to the Harvest Festival it was, unless one also wore the traditional black triangular eye-paint of the Pumpkin King.

Many people thought, “This is lunacy!” But others thought the robots did more good than harm, all things considered, and so in some places the robots are used, while in other places they are shunned.

The end.

The issue with set -e is that it’s hideously broken and inconsistent. Let me copy the examples from the wiki I linked.

Or, “so you think set -e is OK, huh?”

Exercise 1: why doesn’t this example print anything?

#!/usr/bin/env bash
set -e
i=0
let i++
echo "i is $i"

Exercise 2: why does this one sometimes appear to work? In which versions of bash does it work, and in which versions does it fail?

#!/usr/bin/env bash
set -e
i=0
((i++))
echo "i is $i"

Exercise 3: why aren’t these two scripts identical?

#!/usr/bin/env bash
set -e
test -d nosuchdir && echo no dir
echo survived 

#!/usr/bin/env bash
set -e
f() { test -d nosuchdir && echo no dir; }
f
echo survived

Exercise 4: why aren’t these two scripts identical?

set -e
f() { test -d nosuchdir && echo no dir; }
f
echo survived

set -e
f() { if test -d nosuchdir; then echo no dir; fi; }
f
echo survived

Exercise 5: under what conditions will this fail?

set -e
read -r foo < configfile

And now, back to your regularly scheduled comment reply.

set -e would absolutely be more elegant if it worked in a way that was easy to understand. I would be shouting its praises from my rooftop if it could make Bash into less of a pile of flaming plop. Unfortunately , set -e is, by necessity, a labyrinthian mess of fucked up hacks.

Let me leave you with a allegory about set -e copied directly from that same wiki page. It’s too long for me to post it in this comment, so I’ll respond to myself.

I was tempted for years to use it as an occasional try/catch, but learning Go made me realize that exceptions are amazing and I miss them, but that it is possible (but occasionally hideously tedious) to write software without them. Like, I feel like anyone who has written Go competently (i.e. they handle every returned err on an individual or aggregated basis) should be able to write relatively error-handled shell. There are still the billion other footguns built directly into bash that will destroy hopes and dreams, but handling errors isn’t too bad if you just have a little die function and the determination to use it.

People call set -euo pipefail strict mode but, it’s just another footgun in a language full of footguns. Shellcheck is a fucking blessing from heaven though. I wish I could forcibly install it on every developer’s system.

Honestly, the fact that bash exposes low level networking primitives like a TCP socket via /dev/TCP is such a godsend. I’ve written an HTTP client in Bash before when I needed to get some data off of a box that had a fucked up filesystem and only had an emergency shell. I would have been totally fucked without /dev/tcp, so I’m glad things like it exist.

EDIT: oh, the article author is just using netcat, not doing it all in pure bash. That’s a more practical choice, although it’s way less fun and cursed.

EDIT: here’s a webserver written entirely in bash. No netcat, just the /bin/bash binary https://github.com/dzove855/Bash-web-server

set -euo pipefail is, in my opinion, an antipattern. This page does a really good job of explaining why. pipefail is occasionally useful, but should be toggled on and off as needed, not left on. IMO, people should just write shell the way they write go, handling every command that could fail individually. it’s easy if you write a die function like this:

die () {
  message="$1"; shift
  return_code="${1:-1}"
  printf '%s\n' "$message" 1>&2
  exit "$return_code"
}

# we should exit if, say, cd fails
cd /tmp || die "Failed to cd /tmp while attempting to scrozzle foo $foo"
# downloading something? handle the error. Don't like ternary syntax? use if
if ! wget https://someheinousbullshit.com/"$foo"; then
  die "failed to get unscrozzled foo $foo"
fi

It only takes a little bit of extra effort to handle the errors individually, and you get much more reliable shell scripts. To replace -u, just use shellcheck with your editor when writing scripts. I’d also highly recommend https://mywiki.wooledge.org/ as a resource for all things POSIX shell or Bash.

I did some follow-up research and found that subsequent audits found no backdoors. They’re either incredibly sneaky, or the person making these claims wasn’t being entirely honest.

I’m just some idiot on the internet, but please, put a disclaimer of some sort on this. Polymer fume fever is shitty for people and absolutely hideously lethal for birds. I dunno what the LC50 is for birds, but anecdotally, a bird anywhere in the same building has a nonzero chance of dying. Birds in the same room will die. God knows what all those horrible fluorinated fumes will do to people over the long term, but they make you really sick in the short term.

Trolling can be funny, but not when it’s encouraging people to do actively hazardous stuff.

I don’t want an AI shitting up my nice, clean, best-practice following bash.

If you replace fandom.com with breezewiki.com in the URL, you’ll either get an unfucked version of the page, or you’ll get a redirect to a new wiki site that the community actually updates. It’s crazy how fandom doesn’t let communities remove a fandom site, so there are all of these unmaintained and out of date fandom wikis out there.

EDIT: as a demonstration, here’s what happens when you use breezewiki with the Noita fandom page: https://noita.breezewiki.com/wiki/Noita_Wiki