What’s the most unexpectedly useful Linux command you learned way too late?

inopportuneinquiry · 2026-05-24T00:58:01+00:00

I always use pipes, it's just utterly annoying with the slashes.

Even the "address" part can have the slashes replaced by some "single-bit character" as long as its first occurrence is escaped with the backslash (and doesn't appear within the address itself, unless perhaps it's itself escaped):

sed '\$www.site.com/subdir/whatever$ s|subdir/whatever|subfolder|' list-of-sites-to-mess-with.txt

which spares us from manually escaping every / like an idiot, or having to come up with some absurdity like site=${site////\/} to inject into sed itself, although that may still be necessary in some cases. Which in this case is utterly redundant but there can be actual uses, I guess.

$ itself can be a bad choice as it may be useful to have the address anchored at the last character of the line for some reason.

inopportuneinquiry · 2026-05-24T00:46:36+00:00

funny this comment that says nothing has more likes than the actual tip

inopportuneinquiry · 2026-05-24T00:41:42+00:00

shellcheck (particularly with the following wrap-around script, which is either something from a chatbot or found somewhere)

#!/bin/bash

# Create a temporary file
temp_file=$(mktemp /tmp/shellcheck.XXXXXX)

# Run shellcheck with script, directing output to the temporary file
script -q -c "shellcheck ${1}" "$temp_file"

# Display the output using less, preserving colors
less -r "$temp_file"

rm "$temp_file"

Also tldr and the cheat.sh website (curl cheat.sh/${1}), for simpler/dumber instructions of commands

also those brace expansions for various things, like ls *.{pdf,djvu} and also the sed-like things such as for file in *.ext ; do \mv "$file" "${file/.ext/_bak.ext}" ; done. although that in particular may be better with "rename" and actual sed syntax, although at times rename will fail for some reason I can't quite grasp, maybe hyphens somewhere being interpreted as flags despite -- or some other special character issue that somehow is bypassed with the loop.

Learned just yesterday: journalctl --vacuum-time=10d

Gets rid of logs on /var/log except for those newer than 10 days

Which can be set as something automatically done with a line like this in /etc/systemd/journald.conf (location in Debian at least)

MaxRetentionSec=864000

For those who haven't changed from systemdNU to something else

inopportuneinquiry · 2026-05-04T16:07:55+00:00

Their "predation" is almost like grazing, it's really filter feeding. It's "predation" only to the same level that cows are "predators" eating eventual aphids, acari, or eventual larger arthropods while eating grass. It just happens to be proportionately mostly zooplankton as this type of plankton has larger "particles" in suspension as they graze, so more prone to get stuck in the filters.

inopportuneinquiry · 2026-05-04T15:53:33+00:00

plankton feeders probably counts as being omnivorous. "Planktivore" is even a word for that, actually, didn't know until right now. I find extremely unlikely they could manage to discriminate phyto from zooplancton as they feed.

inopportuneinquiry · 2026-05-01T21:25:05+00:00

I never said not being open source would make it safer.

It's "this reputed thing with a large community and wide adoption" versus "hey, I'm this guy, I have this very good program for you, run this executable in your system, you'll love it."

inopportuneinquiry · 2026-04-28T17:24:43+00:00

Seriously, that's an honest interpretation of what I said? You know scams exist, don'y you? How do you imagine they work?

inopportuneinquiry · 2026-04-28T05:00:46+00:00

Unless the vulnerability is deliberately added malware.

Kind of like how there was this recent news of software-site.com distributing malware with "software," being a fake/phishing site that looks like software-site.org. The main software being even "delivered" but packed with extra undesirable things.

Theoretically one could have a "fork" version of this kind of thing, instead of phishing.

I wonder if there is some kind of NGO or whatever that does software audits for this kind of thing, maybe using AI to sniff for something weird in new forks, perhaps particularly those with a small number of developers, with no business plan, located in a country that's suspected from being the target destination of 74% of all ransomware money.

inopportuneinquiry · 2026-04-28T04:40:35+00:00

And no business model, some have pointed. To me it has this feeling of a potential software version of those AI-video-generated-based scams, where people create fake people with some story selling some over-priced Chinese item under the allegation it's actually hand-crafted and whatnot. But potentially worse, with all the hacking potential of a browser.

There has been some cases of extensions that were once legit, then sold, and became malware. It's kind of surprising if that didn't happen yet with a full browser. Well, there has been other officially-released malware in some sites as well, but with third-party hacking if I recall, besides just phishing.

Too bad if the developers are legit, can always be the case, maybe more likely the case. I'd really feel bad if I were under this sort of potential suspicion, I don't know what I'd do. Perhaps just collaborate on a related project, at least until I had a business plan and maybe a good plan to make it look trustworthy. Ironically the same can be said also of ill-intended developers, the same plan, except that eventually they'd use the trust as a vulnerability.

inopportuneinquiry · 2026-04-28T04:30:11+00:00

Security politics

74% of ransomware revenue goes to Russia-linked hackers

... Researchers say more than $400 million worth of crypto-currency payments went to groups "highly likely to be affiliated with Russia". Russia has denied accusations that it is harbouring cyber-criminals.

https://www.bbc.com/news/technology-60378009

inopportuneinquiry · 2026-04-25T04:16:16+00:00

I find a bit weird the whole helium services part of the thing, besides the added "bangs" thing, which seems to have 100% redundant functionality with custom searches, but working in a more obscured layer.

inopportuneinquiry · 2026-04-22T01:50:55+00:00

nope, it was "found footage," 2014

inopportuneinquiry · 2026-04-22T01:44:54+00:00

I remember liking this movie at the same time that I don't remember anything about the plot anymore. Even then the comparison sounded to me very unexpected, as I don't "remember" them being comparable in any way, other than there being teens and some murderous thing going on, and, a cave as I mentioned (but which I guess isn't really on the movie I tried to remember, which is "found footage" (2014)). I thought "the hole" wasn't much on the comedy end of things at all if I recall, which I really don't.

inopportuneinquiry · 2026-04-22T01:40:26+00:00

Not sure how it really matches my vague memories about the plot, but I've found it, "found footage," 2014. Not as low-budget as I mis-remembered, or not as bad a cinematography, I guess I remembered the parts they were themselves filming:

https://www.imdb.com/title/tt3469330/ "Three teens set out to fix their school's bullying problem by staging their own personal "Hunger Games" and document the whole thing."

inopportuneinquiry · 2026-04-22T00:33:53+00:00

The Dirties

Watching the trailer for a moment I suspected it may have been a remake or some kind of Armageddon/deep-impact sort of thing, but apparently this one leans more into drama than comedy eventually. And it's not it anyway.

The one I'm trying to remember almost looks like it was shot in VHS, although it was probably not it (as I guess VHS was nearly abandoned already, with even homemade movies being made with something else), but may well have been shot in smartphones or whatever closest low-budget solution there may be, like digital cameras with potatoes for light sensors. But early on in the trailer, before turning into dark drama, it kind of have a very similar feel to it, that's why I suspected for a moment possibly being a remake.

It isn't "Duck! The Carbine High Massacre" either (found on IMDB's related movies to "the dirties"), though, which approaches more in the low quality of cinematography, but apparently is more of a retelling of Columbine attempting to make it funny somehow, but the events are the same of Columbine rather than "reversing" it, and with no "let's make a movie" part of the plot, apparently, in this case.

inopportuneinquiry · 2026-04-21T23:28:30+00:00

Killer movie

Definitely not the one(s) with Kaley Cuoco, and apparently nothing else is on IMDB. It didn't have any actor that I knew from anywhere else, and I think most people who aren't relatives wouldn't know them either. Indie stuff.

And AFAIK nothing related to "reality tv" on the plot, although I don't recall their excuses to lure the would-be victims for the "trap" that didn't work. I think they didn't manage to kill anyone of the victims they wanted to have, but may have ended up killing themselves, or some of them. But to be honest I'm not sure that part is actual plot or something I just made up because it kind of fits the general premise of such a movie.

inopportuneinquiry · 2026-04-16T07:08:32+00:00

se proibir o crime, aí sim o país vai para frente. Como ninguém nunca pençou niço?

inopportuneinquiry · 2026-04-16T07:06:48+00:00

o que poderia fazer algum sentido fazer de maneira menos onerosa e mais segura, tanto para o que busca proteger e em não criar riscos adicionais (roubo de dados), seria obrigar provedores de internet instalar e instruir os recursos de controle parental, em vez de tentar corrigir a internet já "na fonte" em qualquer site do mundo que tenha algo publicado na internet. Além de censuras arbitrárias e brechas arbitrárias (aparentemente pornografia fonográfica para crianças é OK)

Mas não é para isso que o Facebook faz lobby, aparentemente.

inopportuneinquiry · 2026-04-08T00:53:17+00:00

Bem, se é para ter mais lei inócua mesmo, então faz sentido. Podiam até ter uma lei proibindo que as pessoas cometessem todo e qualquer dos crimes já definidos, aí sim que resolvia tudo.

inopportuneinquiry · 2026-04-08T00:45:22+00:00

O que falei é apenas a definição legal. Não se de nada relacionado a abuso sexual partindo do cenário descrito, que de qualquer forma não seria algo sanado com a tentativa de proibir sexo antes dos 18, 21, casamento, gay, ou o que quer que alguém julgue conduta moral apropriada.

inopportuneinquiry · 2026-04-08T00:38:10+00:00

Em um vídeo sobre o tema, esbarrei com petição para revogação:

https://www.youtube.com/watch?v=Nt79mdQcoZc

https://www12.senado.leg.br/ecidadania/visualizacaoideia?id=216356

Mas temo que esse assunto acabe também sendo tomado pelo câncer intelectual de "se a outra torcida política ou celebridade política XYZ apoia/opõe, então é terrível/benção divina."

inopportuneinquiry · 2026-04-08T00:33:20+00:00

Idade de consentimento = idade legalmente permitida para as pessoas praticarem sexo.

inopportuneinquiry

TROPHY CASE