/dev/chat

Freedo

09:21

can someone help me with sysctl ? been struggling all night... is this allowedhere ?

Stephen Kitt

@Freedo what are you struggling with?

Freedo

I tweaked TCP to improve speeds and it worked. But then I started seeing weird ffmpeg segment fault and "tcp out of memory consider tuning tcp_mem" in dmesg logs. I tried ridiculous large and small values but nothing fixes it

I can reproduce the issue easily by just restarting the server - when it starts everything at once it really creates a lot of load

I know it's not a hardware issue because this start happening with all my servers at once, and I even asked my hosting provider to do all the checks in 1 server

and never at any point my system lacks ram at all, i always have 60gb+ free

this is my current sysctl, the last try I just did pastebin.com/R63TGiVh

Stephen Kitt

ah, this is

0

Q: Is there any side effect of setting rmem_max and wmem_max very high?

I have high traffic load balance servers and I tweaked TCP to get more performance. It worked but now I'm getting kernel messages like "tcp out of memory" I have very high RAM >32GB and barely uses it so I'm not concerned about hardware usage, only max performance. This is my settings right now: ...

sysctl

right?

Freedo

I'm trying to optimize TCP for fat long pipes, my clients are 250-350 ms from my servers and the default linux settings were very bad

yeah it is

I did get a lot of speed improvements tho...like 100% or more in some networks but then I have this weird issues now :(

Stephen Kitt

250-350ms? that’s really high latency

Freedo

09:31

yeah but due to cost i can't get closer to them :( but it does work well

Stephen Kitt

you’re not tuning tcp_mem itself though, have you tried that?

have you seen kernel.org/doc/html/latest/networking/ip-sysctl.html?

Freedo

what do you mean ? net.ipv4.tcp_rmem = 67108864 67108864 67108864 I have this right now

oh I see

Stephen Kitt

tcp_mem, without r or w

Freedo

my values right now are 1540443 2053927 3080886 for this variable

what values do you suggest ?

If those man pages told us a formula or math to calculate the values it would make life so much easier

Stephen Kitt

you could try 67108864, same as your rmem settings

Freedo

09:37

like I have no idea if it should be the same as rmem settings, double, etc

Stephen Kitt

I’m not sure how well things work when all three values are equal though

Freedo

I made all the values equal because I want tcp to send as much as possible as fast as possible due to the high latency. Don't want to waste time starting slow and then increasing...makes sense?

Stephen Kitt

yes, I’m talking about tcp_mem

Freedo

yeah, this is my reasoning for making the values equal for some settings. Don't know if it's ok but doesn't seem to do harm

i'm going to try tcp_mem now thanks!!

but i'm open to any suggestion too :)

for further improvements i mean

it seems 67108864 did not stop the ffmpeg segmentation fault errors will try bigger

net.ipv4.tcp_mem = 134217728 and 268435456 didn't work either. I keep seing the message in my dmesg logs :( don't know what else to do

[ 3611.668801] ffmpeg[292213]: segfault at 19 ip 00000000011597b5 sp 00007ffc82c40490 error 4 in ffmpeg[400000+2704000]
[ 3611.668812] Code: 00 00 00 48 8b 07 c7 44 24 08 18 00 00 00 48 89 4c 24 10 48 8d 4c 24 20 c7 44 24 0c 30 00 00 00 48 85 c0 48 89 4c 24 18 74 1b <81> 78 18 01 0f 32 00 7e 12 83 fe 07 48 63 40 1c 7e 09 85 c0 74 05

I'm getting those errors

Stephen Kitt

10:01

you’d need to figure out why ffmpeg is segfaulting; run it under gdb and look at the output of bt

you might need to install debugging symbols for ffmpeg and any libraries involved

Freedo

it's weird because this only started happening after I made the sysctl changes. so I thought it was that

terdon

@Freedo I just left a comment under your question. It would really help if you could add some detail, there's no explanation there at all.

Freedo

will do

terdon

Please edit your question and add some more detail. What operating system are you using? If Linux, which one and which kernel version? What is the file you are showing us? How are your servers "asking for more RAM"? What symptoms are you seeing? — terdon ♦ 1 min ago

Sorry. I had fixed a typo in the comment and it wasn't showing up!

Freedo

I edited the question. I'm on ubuntu 18.04 and kernel 5.6.4

I just restarted the server with an empty sysctl and it seems the ffmpeg issues continues so I don't even know anymore what could be! Could just be a weird coincidence that this started happening in all my servers after I only changed sysctl

terdon

10:15

@Freedo Thanks, but you still don't tell us what the file you are showing is. And you also give the segfault but don't explain what command you're running. I mean, you never know, maybe the issue is specific to the command you are running, the formats you are giving ffmpeg or whatever. For instance, you don't tell us if this happens only with one specific ffmpeg command or all of them.

Freedo

there are hundred of ffmpeg commands running, so I can't tell

terdon

(note that I don't have the faintest idea what the problem is, I don't know the first thing about this sort of issue, I just figure the more info you give, the better your chances of someone knowing)

Freedo

I'm using dmesg to see the errors

terdon

@Freedo OK, so you see that in dmesg or some other log file? That's relevant information. Basically, don't ever show output or file contents without explaining what output/file you are showing cause otherwise people can't understand what they are reading.

Freedo

I just thought that the tcp memory messages + segfaults were all memory related so the cause would be sysctl

only in dmesg @terdon

terdon

10:19

@Freedo It could well be. Stephen knows a hell of a lot more about that than I do (not hard, I don't know anything about it, as mentioned above). So please edit and i) tell us what file your settings are set in, for all we know you're looking at the wrong file (unlikely, but that's why we need to know) and ii) clarify what your server is doing, why ffmpeg is running. Something like "the server is used to convert media files and is constantly running different ffmpeg commands"

That said, the first thing I would do is to try and reproduce the error by running the ffmpeg command manually so you know exactly where it is coming from.

> [ 3611.668801] ffmpeg[292213]: segfault at 19 ip 00000000011597b5 sp 00007ffc82c40490 error 4 in ffmpeg[400000+2704000]

I think the 292213 is the PID, right? So if you keep track of the PIDs used by the various ffmpeg processes, you should be able to figure out which command is causing the errors. That could help.

Freedo

yes I thought about that, but doing a ps ax | grep ID doesn't give me any results

and yes the server is used to process media so there is a lot of ffmpeg commands running to a tmpfs folder

I can't predict which ffmpeg process will give an error so it's hard to debug...i'm totally lost here and running out of time :(

terdon

@Freedo by that time it has crashed. You would need to monitor the PIDs either as you launch each process or if that isn't possible by running something like this in a loop:

> ffmpeg.pids; while :; do ( cat ffmpeg.pids; ps -ao pid,args ) | sort | uniq > temp.file && mv temp.file ffmpeg.pids; done

Obvious race condition there, so you might miss one or two but that should get most of them. All of them even, in most cases.

Stephen Kitt

Or you could rename the ffmpeg binary, and replace it with a shell script which logs its arguments, tries to run the renamed ffmpeg, and records the exit status (so you can find runs which segfaulted).

Freedo

ok will run that and restart my services, thanks a lot

it's saying ffmpeg pids doesn't exist? the loop doesn't seem to be doing anything

terdon

@Freedo If it says the file doesn't exist, you didn't include the > ffmpeg.pids in the start. But that's fine, it will exist after the first iteration. And it won't print any output, to see if it's working, run tail -f ffmpeg.pids

But Stephen's suggestion is much better.

You would do something like this:

sudo mv /sbin/ffmpeg /sbin/ffmpeg.orig
cat <<EoF > /sbin/ffmpeg
#!/bin/sh
/sbin/ffmpeg.orig "$@" &
echo $! >> /tmp/ffmpeg.pids
EoF
sudo chmod a+x /sbin/ffmpeg

1. rename the existing binary
2. create a simple script named ffmpeg that calls the binary with the arguments you give it and also logs the PID
3. make the script executable

Stephen Kitt

10:33

echo $! : $* >> /tmp/ffmpeg.log would allow matching pids with command-line arguments

Freedo

will try now, it would help a lot to see full ffmpeg command yeah

you guys have the best ideas

terdon

@StephenKitt yes, even better indeed

sudo mv /sbin/ffmpeg /sbin/ffmpeg.orig
cat <<EoF > /sbin/ffmpeg
#!/bin/sh
/sbin/ffmpeg.orig "$@" &
printf 'PID: %s COMMAND: /sbin/ffmpeg.orig %s\n" "$!" "$*" >> /tmp/ffmpeg.pids
EoF
sudo chmod a+x /sbin/ffmpeg

Stephen Kitt

a wait might be helpful too, to avoid increasing load by accidentally parallelising ffmpeg runs

Freedo

I struggled a bit to replace the ffmpeg file because it was in use but got it now. Will run the script now and hopefully will be able to locate the source of the issues

hmm I'm getting unterminated quoted string. think a syntax error somewhere?

my file look like this

cat <<EoF > /usr/bin/ffmpeg
#!/bin/sh
/usr/bin/ffmpeg.bak "$@" &
printf 'PID: %s COMMAND: /usr/bin/ffmpeg.bak %s\n" "$!" "$*" >> /root/ffmpeg.pids
EoF

fra-san

It should be:

printf 'PID: %s COMMAND: /usr/bin/ffmpeg.bak %s\n' "$!" "$*" >> /root/ffmpeg.pids

@Freedo I think.

Freedo

10:45

I'm running that now...waiting for services restart

well this is weird, now it seems like my services are refusing to run ffmpeg? it's not logging anything but if i call ffmpeg -i it's logged correctly.. i'll research what could be happening

terdon

Whoops, yes, sorry @Freedo and thanks @fra-san.

Freedo

my software is calling ffmpeg from another path, will try to log again now

and np terdon lol! i have been a (shitty) linux sys admin for like 2 years now and i'm not even close to your guys lol

terdon

In my defense, I am a biologist! :P

Stephen Kitt

@terdon the script mutated twixt brain and chat

terdon

If anything I say contradicts what Stephen or fra-san say, believe them, they will probably be right.

About *nix stuff anyway. Not about beers. They don't know crap about beer! :P

Stephen Kitt

10:54

mknod /dev/beer — oh wait I need to allocate some numbers

Freedo

well my software was refusing to run ffmpeg because obviously it can't log to /root lol

so dumb

terdon

log to /tmp that's easier

Freedo

ok i got it to run without issues as my non privileged user, but it's not logging the PID? or anything after /usr/bin/ffmpeg.bak

i ran ffmpeg -i to test

fra-san

@terdon Actually, I love IPAs...

And I'm not a professional sysadmin nor I have a CS background. So, to summarize, if what terdon says contradicts what I say... believe what Stephen says :-)

Freedo

my log is only repeating those lines

PID:  COMMAND: /usr/bin/ffmpeg.bak
" "" ""PID:  COMMAND: /usr/bin/ffmpeg.bak
" "" ""PID:  COMMAND: /usr/bin/ffmpeg.bak
" "" ""PID:  COMMAND: /usr/bin/ffmpeg.bak
" "" ""PID:  COMMAND: /usr/bin/ffmpeg.bak

shouldn't it appear my ffmpeg -i there?

well i'm not professional either or studied this...I use google a lot and usually it's enough lol

Stephen Kitt

11:06

what does cat /usr/bin/ffmpeg show?

Freedo

it seems for some reason when i created the file with cat it ate the @

:facepalm:

αғsнιη

@Cbhihe by the way your "about you" commnad should be updated

any characters within bracket expression is just a literal character except some exceptionally

Stephen Kitt

@αғsнιη Cbhihe doesn’t frequent chat and therefore is unlikely to see this

αғsнιη

@StephenKitt but I ping him/her with @, still xe will not get the ping?

that's not working in chat?

terdon

@fra-san I knew I liked you for a reason! :P

αғsнιη

11:16

wait amomnet

Freedo

I made sure the ffmpeg is like you guys said but is still not logging/executing right

fra-san

@αғsнιη It only works for the limited number of "pingable" users.

Freedo

#!/bin/sh
/usr/bin/ffmpeg.bak "$@" &
printf 'PID: %s COMMAND: /usr/bin/ffmpeg.bak %s\n" "$!" "$*"' >> /tmp/ffmpeg.pids

fra-san

Those that have been seen in chat recently, whose name "tab-completes" after you type "@" in a chat message.

They are also listed at chat.stackexchange.com/rooms/pingable/26

αғsнιη

@fra-san 🙄

hmmm, didn't know that. I remember one time I think he was @terdon I'm not sure, he used some power of his Mod and pinged someone

Freedo

11:19

my log is only this now:

PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak
" "$!" "$*"PID:  COMMAND: /usr/bin/ffmpeg.bak

Stephen Kitt

@Freedo your quoting is still wrong

printf 'PID: %s COMMAND: /usr/bin/ffmpeg.bak %s\n' "$!" "$*" >> /tmp/ffmpeg.pids

Andras Deak

5 double quotes in a string are always suspicious

fra-san

My fault, sorry. I previously posted a wrongly quoted line, immediately deleted the message and re-posted a fixed one.

Freedo

oh yeah now i see the ffmpeg commands flowing

terdon

@αғsнιη yes, mods can ping any user but non-mods can only ping the ones who have been in the room in the past 2 or 3 weeks.

αғsнιη

11:22

@StephenKitt test

Stephen Kitt

@αғsнιη that works because I’m pingable

Cbhihe isn’t

αғsнιη

sorry, I was testing something else

Andras Deak

@terdon directed replies always work.

oh that was terdon

αғsнιη

I want to know how can I reply on my own replies here

Andras Deak

edited :P

Stephen Kitt

11:23

@AndrasDeak “directed replies always work” — even on ancient messages whose authors are no longer pingable?

Andras Deak

@StephenKitt my point exactly, yes

Stephen Kitt

@αғsнιη you need to find your message id and start your message with it, prefixed with a colon

Andras Deak

@αғsнιη you need to grab the message ID yourself

Freedo

I see the pids in my dmesg log, but when I grep the log file it doesn't give any results?

Andras Deak

@Freedo buffering?

or what do you mean by "the log file"?

your grep might be broken too

αғsнιη

11:25

@terdon got it, I was thinking for something like pinging using SE global profile Id, with that we can ping? or still no way for us?

Andras Deak

copy a few lines that you want to find into a regular file and then practice grep on that

@αғsнιη that's the mod superping

Freedo

I think i got it now

you guys are the best

now I can at least know which ffmpeg proccess is crashing

αғsнιη

@StephenKitt yes, I did like that but it brought your message id after I hit enter

terdon

@αғsнιη no, you can only ping those who have been in the room recently

Andras Deak

specifically people in chat.stackexchange.com/rooms/pingable/26

terdon

11:27

Ah yes, hurrah for hidden features!

αғsнιη

yes, understood, thanks

@StephenKitt but where to find my message Id? after some grace period there is no way to find the Id seemz

Freedo

ok so now that i can find the problematic commands, how do I debug the segfault? strace?

Andras Deak

@αғsнιη context menu -> permalink

αғsнιη

ahhh, much difficult

Andras Deak

yes

it's manual ;)

Freedo

11:30

why would ffmpeg have a segfault ? with files that never caused a issue before?

αғsнιη

@AndrasDeak thanks

Stephen Kitt

@Freedo run the command with gdb (gdb --args ffmpeg ...), then run, and after it crashes, bt to see where it’s crashing

@Freedo usually it’s a bug, which might have appeared because of updated libraries

αғsнιη

everytime it was harming me that cannot continue reply on my comments 😂

Freedo

weird. because the only thing i really did to those servers recently was sysctl, and apt upgrade

Andras Deak

apt upgrade sounds like "updated libraries"

Have you checked if there's a newer ffmpeg version out since?

apt policy ffmpeg for instance can tell you

Freedo

11:33

my software uses it's own ffmpeg version, so it's pretty old yeah

Stephen Kitt

@Freedo ah, you probably need to rebuild it then, if that’s possible

Andras Deak

@Freedo can you not rely on ffmpeg as an external dependency?

Freedo

do you guys think i should just try to do that instead of debugging further ?

lol the server load is at 1700, this never happened before the ffmpeg wrapper

terdon

@αғsнιη you can also use a userscript to reply. Unfortunately, it isn't maintained anymore but this is the code you can add with tampermonkey or equivalent:

/** @preserve
// ==UserScript==
// @name           Chat Reply Helper for Stack Exchange sites
// @namespace      oliversalzburg.github.com
// @version        2.6.2
// @description    Handle structured conversations more conveniently
// @homepage       github.com/oliversalzburg/se-chat-reply-highlight
// @grant          none
// @include /^https?:\/\/chat\.stackexchange\.com/.*$/
// @include /^https?:\/\/chat\.stackoverflow\.com/.*$/
// @include /^https?:\/\/chat\.meta\.stackexchange\.com/.*$/

pluginsaddonsextensions.com/mozilla-firefox/…

Stephen Kitt

@Freedo that’s because the wrapper starts ffmpeg in the background and finishes immediately

see my wait comment a while ago

αғsнιη

11:41

@terdon ahh, god, what are these codes!

Andras Deak

@αғsнιη partially minified JS

Freedo

I'm going to try to download latest stable ffmpeg and replace my binary and hope for the best, but probably won't work

Andras Deak

it hacks your browser to inject new functionality on certain webpages

Userscripts can also do harm so make sure you trust the person who's giving it to you. In this case it's terdon. Ummm...

αғsнιη

@AndrasDeak I would prefer manual copy'n'paste way

😜

Andras Deak

@αғsнιη so...?

8 mins ago, by Andras Deak

@Freedo can you not rely on ffmpeg as an external dependency?

@αғsнιη when you say "manual copy'n'paste" do you mean "manual rather than copy'n'paste"? Otherwise I have no idea what you're saying, sorry.

Stephen Kitt

11:44

BTW the second draft of the 202x revision of POSIX is out for review, see opengroup.org/austin for details

αғsнιη

@AndrasDeak I mean coping from Permlink

@αғsнιη test

Andras Deak

aaah, OK

yeah, I prefer that too

terdon

@AndrasDeak fair point. I can tell you that the script was originally written by this guy:

Der Hochstapler

81.2k 56 251 296

windows-7 windows linux google-chrome command-line windows-8 ubuntu

And that I've been using it for several years and never had a problem. It was also, at the time, available in the chrome store.

Andras Deak

I'd still grep the code for rm -rf. You know, just to be safe.

Freedo

@AndrasDeak what do you mean you don't like the thrill of running code from strangers on the internet ? :P

Stephen Kitt

11:50

$ rm -rf /
rm: it is dangerous to pull a terdon
rm: use --no-terdon-involved to override this failsafe

2

Andras Deak

@Freedo strangers are one thing. But we're talking about terdon.

Freedo

I was joking lol

Stephen Kitt

Freedo might not be aware of the meme

23

Q: Are there any memes on Ask Ubuntu?

Just curious. After reading about the infamous "Boat Programming" question, I wondered if anything like that has existed on Ask Ubuntu.

discussion fun

Freedo

I'm not!!

ooh lmao

Stephen Kitt

seniority as a sysadmin is measured in how many systems one can destroy inadvertently

Freedo

11:53

it happens to the best

but anyone who spends like 10min in linux should know what rm does lol

terdon

@StephenKitt go drink an IPA or something.

:P

Andras Deak

IPA, the lego of beers

Stephen Kitt

@terdon I’m sure a PPA with a patched version of coreutils would achieve a decent level of popularity on AU

terdon

Andras Deak

heh, I still can't see the original question

Freedo

11:55

I compiled a new ffmpeg version and i'm running it now

crossing my fingers

Andras Deak

I guess we'll never know why you have to vendor ffmpeg yourself

Freedo

and the segfaults continues :(

terdon

in Ask Ubuntu General Room, Jun 23 '15 at 16:43, by Mudit Kapil

@Fabby How can Linux be cruel? I read it somewhere.

Freedo

I'm testing ffmpeg static 4.4 from john now

Stephen Kitt

what’s wrong with your distribution’s ffmpeg?

Andras Deak

12:03

@terdon huh, so I could see the original question

Freedo

idk, i never uses it? must be ancient too probably

Andras Deak

So you answer Stephen just like that? I'm hurt.

Freedo

oh i mean no offense

Andras Deak

but that's also a terrible answer so I'll just phase out :P

Stephen Kitt

@Freedo it might just work though ;-)

Freedo

12:06

with ffmpeg 4.4 it doesn't even run :(

it seems my software uses some ffmpeg flags that are not present in newer versions

Stephen Kitt

@Freedo so perhaps version 3.4.8 as provided in 18.04 would work

Freedo

yeah will try that too

Jeff Schaller

I haven't finished reading this, and it should probably hit our Meta at some point, but FYI:

2

Q: The future of Community Promotion, Open Source, and Hot Network Questions Ads

It's now May, and if Community Promotion or Open Source Ads are something you care about, you may have noticed that there hasn't been a 2021 refresh yet. In case you missed this post, please check it out for some details about why the refresh was pushed back, and why a project around the rethinki...

discussion featured advertising announcements community-promotion-ads

Freedo

yeah no luck with ffmpeg 3.4.8

I think i give up for now, i will probably hire a professional to fix this

thanks for all the info guys I learned a lot

if anyone wants to take it pm me if this is possible here, or leave some form of contact...

ilkkachu

The funny thing about the word "disinfectant", and the M-W definition is that even if it says "especially: a chemical agent that is used especially on hard surfaces", the whole definition of "disinfect" there refers to cleaning non-living things: "1. disinfect: to cleanse (a surface, a device, a supply of water, etc.) ...". All the examples are about cleaning objects or purifying water.

Jeff Schaller

12:22

I think it may be a bit like that gray dress thing; you can interpret comments positively or negatively based on some pre-existing bias. Are they rambling off ideas to help stop a virus? Are they earnestly suggesting that people go off and drink bleach? Again, I'm not in the habit of taking medical advice from politicans (or actors, lawyers, military leaders, etc), so I don't have a dog in this fight.

ilkkachu

Blah, I thought I saw some definition for "disinfect" which basically excluded use on living things, but it was the other way around, Wiktionary says of "antiseptic": "Generally includes only those that are used on living objects (as opposed to disinfectants) and aren't transported by the lymphatic system to destroy bacteria in the body (as opposed to antibiotics)."

but yeah, maybe I should go to English.SE

"some stuff he had heard about and didn't understand"
That part is the/a problem in itself.

Jeff Schaller

or history.SE ;)

ilkkachu

hehe

jesse_b

@ilkkachu I never said there wasn't a problem simply that the problem wasn't nearly as bad as the media made it out to be.

Also I got notified like 25 times as you edited that >.>

ilkkachu

@jesse_b oops, sorry! :D I forgot it pings for edits too. also I hate how the formatting works differently in chat vs. elsewhere

jesse_b

12:32

And really when looking at it I think he is talking about bleach/misc household cleaners when he says disinfectant but then he goes on to say "Is there a way we can do something like that...". Which is just some sort of wishful thinking. Essentially: "Disinfectant works so well on surfaces, can't we just make something like that for humans?"

important things to look at: "Is there a way" (asking) "Something like that" (explicitly not exactly that)

terdon

@AndrasDeak yeah. I only deleted my answer with the dangerous command. I posted the screenshot because it can be seen there (mod thang).

jesse_b

@ilkkachu My problem with it is these things actually give him support. If they had just reported that Trump thinks we should try to make human safe bleach, or that Trump thinks we should just invent a miracle cure all drug (like that hasn't already been tried a million times), etc it would be no issue. But what they did was say "Trump suggests taking bleach for covid" which is just clearly not true. A lot of people just support him more when they see any lie about him.

ilkkachu

12:51

@jesse_b yeah, esp. in cases where reporting only on what was actually said and done would be damning enough. "Trump draws inspiration from household cleaning agents, wonders if medical professionals could develop a cure for Covid" :P

jesse_b

@ilkkachu That's actually perfect lol

Andras Deak

@terdon it was just a peculiar reply to that first message.

ilkkachu

then again, someone would think him saying that means actual professionals never thought about even trying ;D

but yeah, reminds me of the way the media sometimes treats the True Finns up here, and of the latest RMS fiasco.

Andras Deak

filibuster party

Tomasz

13:36

hi, what would you say to a new raku tag for perl6? i could retag a few old posts for a start if you introduce this tag

Jeff Schaller

@Tomasz My initial reaction would be to alias it to perl

sorry, "synonym" is the right word

Tomasz

that's exactly the opposite of my intention

i wonder what's raku's place in U&L today and in the future

this might help in research and anyhow - doesn't it deserve a separate tag?

Jeff Schaller

well, reading about Raku, I see that backwards compatibility is not a goal, so perhaps there's merit to a separate tag.

Tomasz

for a comparison - from what i see python3 is not linked to python

Jeff Schaller

python3 could really use an excerpt and wiki!

Tomasz

13:46

defo

Stephen Kitt

@JeffSchaller yes, Raku is not Perl

Andras Deak

I thought raku was perl 6

@JeffSchaller that's just python

Stephen Kitt

@AndrasDeak right, but IIRC it was decided to drop all semblance of backwards compatibility, hence the change of name, and continue maintaining Perl 5

Tomasz

from what i know pyhon3 is more python than perl6 is perl

Andras Deak

Yes, python 3 is all python

Jeff Schaller

13:53

@AndrasDeak well, perhaps something to make it even more obvious that it's v3? shrug I'm ever the optimist that tag excerpts & wikis will be helpful.

Andras Deak

@JeffSchaller synonym of just python? :P Mind you I haven't checked your questions on the topic.

Jeff Schaller

@AndrasDeak I think we missed a step somewhere. The python3 tag is distinct from the python tag because it's not backwards compatible. The python tag has an excerpt & wiki, but the python3 one does not.

(I was lazily hoping to find out why we had a python3 tag by reading its excerpt & wiki here)

Tomasz

python has very scant tag info too, so in case it's merged with p3 someones might win a double reward

Tomasz

14:08

will someone create the raku tag for my librarian frenzy then, or should i check tomorrow?

Andras Deak

14:21

@JeffSchaller on the contrary. Python 2 is not compatible with python :P

αғsнιη

@AndrasDeak sometimes grep also don't save you from a danger, see for example this basic encrypted script

-4

Q: What does this bash script do?

I found a bash script in the Andronix website, for enabling sound in GNU/Linux rootfs running in Termux. However, the contents of the script seem to be cryptic, and I want to know what commands I am running before I run them. How to decode such a bash script, and what all commands does it run? z=" "

shell-script

Andras Deak

@αғsнιη well we were talking about JS so JSF**k applies

Stephen Kitt

14:38

Is rm -fv * .* | grep \^removed | wc -l a valid answer to question 1 in

0

Q: a couple unix questions I could use help with

I need a UNIX command that counts and outputs the number of ordinary files (hidden as well as non-hidden) under your current working directory. The command may involve two pipes and should simply output one number. I need two Unix commands. The first one should copy the file passwd under /bin ...

linux

Andras Deak

Question is how careful their TA is

Jeff Schaller

@StephenKitt step 0: switch to the root user and cd /bin

Stephen Kitt

@JeffSchaller which would also serve to show that processes in a pipeline can start in parallel!

Jeff Schaller

15:20

Experience is what you get after you need it. We're all about educating our users :)

Stephen Kitt

@JeffSchaller that could be our slogan — “Increase your experience. You might not like everything you’ll learn along the way, but you’ll definitely learn!”

Jeff Schaller

15:42

https://fs.blog/2021/05/advice-for-young-scientists/ -- "Medawar believes it’s unnecessary for scientists to spend an enormous amount of time learning techniques and supporting disciplines before beginning research:

*“As there is no knowing in advance where a research enterprise may lead and what kind of skills it will require as it unfolds, this process of ‘equipping oneself’ has no predeterminable limits and is bad psychological policy….The great incentive to learning a new skill or supporting discipline is needing to use it.”*"

Ironic timing for that blog post :)

jesse_b

Stephen, slayer of worlds and king of all things docker. Do you know why dell's racadm command would fail when I use the default bridged network mode but work when I use host network mode?

I can ping the host and telnet to the host in either network mode but I am going over a vpn

Stephen Kitt

@jesse_b not off the top of my head...

jesse_b

I recently reimaged my mac and that is when this started, prior to that it worked in the default mode and it works in default mode for my other teammates. I thought networking was broken over the vpn altogether but it seems that isn't the case

αғsнιη

I have a big problem that I don't like a line start with uppercase letters except some, like these are OK if they come at the beginning, I don't know the reason yet

Jeff Schaller

@jesse_b there's the problem: your Mac is now thinking different :)

@αғsнιη you and every person writing on the Internet! I'm grumpy about it because I learned that English sentences are capitalized.

αғsнιη

15:58

@αғsнιη these characters only are fine to me I, U, Z, V to start the line

that's why I chose my name first letter lowercase

all uppercase is also fine

most of the times I write my answers first letter lowercase but it gets edited often by editors

that is also fine, I myself really don't like to start with uppercase

except those 4 letters above said, it's a big issue to me I think?

I even don't like even numbers 😂😂

except some

terdon

It isn't really a question of opinion that one. Sentences need to start with a capital letter and end with either a . or a ! or a ?

That's just the rules of the language.

αғsнιη

but I feel uncomfortable when using the thing that I don't like

:/

Stephen Kitt

@terdon shame about the grammar :-P

αғsнιη

16:13

even we have a capslock day for that

🤦🏻‍♀️

@terdon and semicolon? 😝

Prabhjot Singh

What is the difference.
```
awk '{if($1==x){i=i" "$2}else{if(NR>1){print i};i=$0};x=$1;y=$2}' test.cov <(echo)
awk '{if($1==x){i=i" "$2}else{if(NR>1){print i};i=$0};x=$1;y=$2}' test.cov; echo
```

terdon

@αғsнιη Strictly speaking, no. A semicolon doesn't end a sentence.

Prabhjot Singh

@terdon If writing two commands in single line?

αғsнιη

@PrabhjotSingh first one is single command, second is two separate commands

@terdon hmm.

terdon

What @αғsнιη said. The first is using the output of echo (an empty line) as the second input file for your awk command. The second is running your awk on the file test.cov only, and then as a completely separate command, it runs "echo".

> In the English language, a semicolon is most commonly used to link (in a single sentence) two independent clauses that are closely related in thought. When a semicolon joins two or more ideas in one sentence, those ideas are then given equal rank.[2] Semicolons can also be used in place of commas to separate the items in a list, particularly when the elements of that list contain commas.[3]

Prabhjot Singh

16:19

@αғsнιη Thanks. Shukriya

terdon

A semicolon doesn't end a sentence. Usually, it ends a part of a sentence; but allows the sentence to continue until the full stop.

(and that was a bad example of semicolon use, it doesn't make much sense there, it is just to illustrate the point)

αғsнιη

@terdon I also using semicolons a lot in my answers, I don't know if you noticed it or not.

terdon

I haven't, no.

Here's a better quote:

> Although terminal marks (i.e. full stops, exclamation marks, and question marks) indicate the end of a sentence, the comma, semicolon, and colon are normally sentence-internal, making them secondary boundary marks. The semicolon falls between terminal marks and the comma; its strength is equal to that of the colon.[10]

Semicolon

The semicolon or semi-colon ; is a symbol commonly used as orthographic punctuation. In the English language, a semicolon is most commonly used to link (in a single sentence) two independent clauses that are closely related in thought. When a semicolon joins two or more ideas in one sentence, those ideas are then given equal rank. Semicolons can also be used in place of commas to separate the items in a list, particularly when the elements of that list contain commas.The semicolon is likely the least understood of the standard marks, and so it is not used by many English speakers.In the QWERTY...

αғsнιη

good to know! thanks

Andras Deak

16:34

@terdon unless it's a Greek question

>>> '\N{greek question mark}'
';'

jesse_b

A semicolon may not end the sentence but it does end the conversation; good day sir!

terdon

@AndrasDeak Ah well, then I'd be writing έτσι βρε φίλε, σωστά;

Andras Deak

φίλε as in file? :D

terdon

16:51

heh, no. φίλε means friend. "Βρε φίλε" (vre file) is a colloquial way of saying something like "come on, dude".

Andras Deak

17:14

I can read the letters, I just don't know what they mean.

Oh, file as in -phile. Nice.

terdon

Yes, exactly.

Freedo

18:37

@terdon can i hire you ?

Prabhjot Singh

18:58

Disinfectant in Tabers dictionary.

terdon

19:28

@Freedo lol. I take it you found a solution?

jesse_b

Terdon for hire

Will work for IPA

Freedo

19:45

@terdon no luck yet :(

terdon

@jesse_b ha! :P

@Freedo :(

Freedo

It seems to be happening randomly and not specific to any ffmpeg source files, and it seems to be happening only when the load is very high on the tmpfs folder now

jesse_b

22:04

Is my docker question really that bad? :(

Andras Deak

22:24

more data, less rant, obvs

jesse_b

Also my reputation has nothing to do with how stupid I still am ;)

Andras Deak

22:48

I'm so ignorant on the subject that I can't even tell if your question contains enough information, but there's nothing ranty about it.

Michael Homer

That seems like a pretty typical interaction on the site.

jesse_b

23:19

@AndrasDeak Well he made that comment before I made an edit in which I tried to rewrite the question to have less fluff but in my opinion it wasn't really ranty before either. It had a slight amount of potentially extra information but I don't think it's even extra just I don't know of a good way to word it in a concise manner.

jesse_b

23:34

@JeffSchaller: You camp?

Andras Deak

@jesse_b yeah, it was fine

it's not like you pecked their chimney or anything

jesse_b

@AndrasDeak The animals are conspiring against me. This morning there was a rabbit outside the window right behind my monitor and it was actively taunting my cat and my cat was going crazy almost knocking my stuff over

Andras Deak

23:50

awww, bunny

the only things taunting my pet here are doves, which are just pigeons in formal attire as far as I'm concerned

jesse_b

@AndrasDeak There are some pigeons that are incredibly ornate. One of my previous neighbors used to raise and "fly" pigeons and he had some crazy ones that were worth several thousand dollars each

Andras Deak

We only get the "avian sewer rat" kind here

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