Julia Evans

what are some problems with quitting programs in the terminal you’ve run into? so far I have:

- not knowing how to quit vim (or some other program like nano etc)
- programs not responding to ctrl c
- a background program being killed when you close your shell

what am i missing?

Aug 26, 2024 at 7:08pmWeb
Show threadPete KeenAug 26, 2024
@b0rk I never remember how to exit nano despite the commands literally being printed on the screen at all times. Too many decades of vim/emacs
Show threadDenys DmytriyenkoAug 27, 2024

@zrail @b0rk the ONLY magic incantation I have to remember for the rest of my life to get out of the darkest places is - escape, colon, Q, exclamation-mark, enter

the rest is easy, the rest is straightforward and intuitive, just as calming as a lullaby...

Show threadAnthonyAug 26, 2024
@b0rk accidentally backgrounding a task that prints to stdout/stderr
Show thread/meAug 27, 2024
@stormsweeper @b0rk or backgrounding a task that reads from stdin and thus gets paused
Show threadMichael HansonAug 26, 2024
@b0rk it’s not super common but I have seen various development servers (Python, node) get mysteriously disconnected from their process group and just hang out until I notice and kill -9 ‘em. Usually manifests as a port conflict when I start something up.
Show threadAndrew McHargAug 26, 2024
@b0rk maybe not restoring the terminal to a good state? (Needing to run reset etc)
Show threadwb x64Aug 26, 2024
@AndrewMcHarg @b0rk nslookup is notorious for this, I had to look up and memorize stty sane simply for it after years of pain
Show threadnolenAug 26, 2024
@b0rk I used to get really confused by programs not exiting when i ran `kill $pid` (not knowing about kill -9 / not realizing that kill is "send a signal" more than "stop this thing", etc)
Show threadÖlbaumAug 26, 2024
@eieio @b0rk It’s so obvious, though: KILL: “Kend It Le signaL”
Show threadJulia EvansAug 26, 2024
@eieio thanks!
Show threadnolenAug 26, 2024

@b0rk thinking about it more, I guess my `kill` confusion is basically the same as the "programs not responding to ctrl c" that you mentioned. both are just sending a signal that I used to assume was "close the program" but it's a little more complicated than that.

I'd never considered that before though!

Show threadsamir, an unknown quantityAug 26, 2024
@b0rk On the theme of background programs: accidentally pausing something with Ctrl+Z when I meant Ctrl+C and not knowing how to get it back.
Show threadStefan GastAug 26, 2024
@samir @b0rk Something similar: Backgrounding a graphical application with Ctrl+Z, forgetting that I did it and then thinking that the application just froze. This mostly happens because I forget the & to start them in the background in the first place.
Show threadStefan GastAug 26, 2024
@samir I guess you already know it, but usually a simple fg does the trick. Or fg %1, fg %2 – the jobs command will tell you the number.
Show threadsamir, an unknown quantityAug 26, 2024
@notbobbytables Yep, I am now intimately familiar with bash job control. I'm not sure whether I'm proud or horrified about this. :-p
Show threadStefan GastAug 26, 2024
@samir 😂
Show threadMotAug 26, 2024
@b0rk Accidental Xon/Xoff can be very confusing. Also maybe backgrounding a process
Show threadJan Lehnardt Aug 26, 2024
@b0rk - no response to kill <pid>
Show threadmhdAug 26, 2024
@b0rk Ctrl-S / Ctrl-Q ?
Show threadHarry PercivalAug 26, 2024
@mhd @b0rk omg yes this, so much. It's just a fatfinger usually and your program is totally, inexplicably stuck!! And actually there's nothing wrong, you just need to *know* about ctrl-q...
Show threadFi 🏳️‍⚧️Aug 26, 2024

@b0rk

a background program writing stderr to the terminal while I'm trying to do something else

Show threadFi 🏳️‍⚧️Aug 26, 2024

@b0rk

e.g. I thought it was closed but...

Show threadAaron Brick — אהרן בריקAug 26, 2024
@b0rk Needing to use kill -9, programs that get respawned by their parent after terminating, and determining which one of several similar processes to kill.
Show threadGaëtan DuchaussoisAug 26, 2024
@b0rk you just logged into a machine you expect to have bash or zsh and you accidentally run a built-in command like ls which launch a program you don't know how to leave. This works on openvms default shell
Show threaddr 🛠️🛰️📡🎧Aug 26, 2024

@b0rk Sometimes if C-c doesn't work I'll C-z. In theory, 'jobs' shows that job, but I don't know how to kill from there.

So I use ps | grep, but it can be a hassle.

And if there's a subprocess, I get <defunct>s and a mess.

Show threadWyatt (🏳️‍⚧️♀?)Aug 26, 2024
@davidr @b0rk C-\ is usually the right move if C-c doesn't work. C-z tends to just send stuff to the background.
Show threaddr 🛠️🛰️📡🎧Aug 26, 2024
@wyatt8740 @b0rk Huh, I've never heard of C-\. I'll try to remember that one
Show threadHarry PercivalAug 26, 2024
@davidr @wyatt8740 @b0rk same TILLLLL thank you <3
Show threadWyatt (🏳️‍⚧️♀?)Aug 26, 2024
@davidr @b0rk it sends SIGQUIT which is stronger than SIGINT. :)
C-d for SIGHUP can also be useful to try but sigquit is more likely to worki.
Show threadStephenAug 26, 2024
@davidr @b0rk for the record:

$ kill -9 %1

will kill the first backgrounded job.
Show threadStephenAug 26, 2024
@davidr @b0rk also when I was first learning I suffered the inverse - I was trying "undo" and typed ctrl-z, thereby sending vim into the background, and I had no idea how to bring it back!
Show threaddr 🛠️🛰️📡🎧Aug 26, 2024
@stephen @b0rk MS hijacking C-a to "select all" when I want to edit the beginning of a line has lost me a LOT of email bodies.
Show threadAdrianna TanAug 26, 2024
@b0rk I keep forgetting all the commands that would make things less tedious. Like I remember ctrl a for going to the start of the line but somehow can’t remember the ones about going to the end, or going word by word, or clearing the line
Show threadMad BAug 27, 2024

@skinnylatte
Same ...but Adrianna did you know: option + click puts the terminal cursor wherever you choose on the line?

Maybe you did but that trick is still gold to me
@b0rk

Show threadAdrianna TanAug 28, 2024
@Oaktag @b0rk no, thank you!!
Show threadKim van WykAug 26, 2024
@b0rk not quite the same thing, but I still surprise myself pressing ctrl-z absent mindedly in a vi or other editor session expecting it to undo my action and instead it backgrounds the program. The first many times I did that I had no idea why the editor went away.
Show threadRiley S. FaelanAug 26, 2024
@b0rk The third one is not like the others. Read up about the nohup utility (and possibly about the setsid() and setpgid() syscalls).
Show threadJulia EvansAug 26, 2024
@riley as usual not looking for people to explain these to me (i know why it happens!), just more problems
Show threadChris Lilley 🏴󠁧󠁢󠁳󠁣󠁴󠁿Aug 26, 2024
@riley @b0rk A user survey is not a request for help.
If you disagree, try writing "I think you should already know this" as the answer to any exam question.
You will be right! and also score zero.
Show thread∴ esoterik ∴Aug 26, 2024
@b0rk there's the issue that you might think you've quit the program, but it has left around child processes that become zombies, which might still be doing the task you thought you stopped
Show threadJulia EvansAug 26, 2024
@d6 ugh yea this is such a good one thanks
Show threadThomas AmbergAug 26, 2024
@b0rk "broken" terminal (+1 for @AndrewMcHarg), e.g. after using screen; sometimes stty sane helps
Show threadHarry PercivalAug 26, 2024
@tamberg @b0rk @AndrewMcHarg this - sometimes if I cat a binary file by accident, the terminal gets into a totally weird state. i usually use the "reset" command. (not about quitting programs strictly speaking, apologies)
Show threadAndrew McHargAug 27, 2024
@hjwp @tamberg @b0rk I have done this more times than I can count 🤣. Usually it’s me thinking it might be binary but gambling on my terminal it is not.
Show threadJani NikulaAug 26, 2024
@b0rk Scripts or complex pipelines where ^C just kills one program, and stuff keeps running and you keep hitting ^C.
Show threadEmil VelikovAug 26, 2024
@jani @b0rk for script you can Ctrl+Z + kill. Haven't found a trick for complex pipelines.
Show threadMercAug 26, 2024
@b0rk Programs that leave your terminal in a weird state. Like, they do some graphical things, but don't undo them, leaving the characters "corrupted" or the cursor invisible.
Show threadCees-Jan Kiewiet  Aug 26, 2024
@b0rk kill -9 doesn't work
Show threadCorrel RoushAug 26, 2024
@b0rk sometimes if a program isn't responding to Ctrl+C I can still break out with Ctrl+Z and kill the job, but sometimes that won't work either
Show threadManuel Strehl 🫏Aug 26, 2024

@b0rk a fun one: https://mastodon.social/@boldewyn/112360724911005279

A foreground Apache exits, when you resize your terminal window. By design.

Show threadQuixoticgeekAug 26, 2024

@b0rk the fun of trying to exit telnet or minicom etc... ctrl+[ is not intuitive...

Other fun one is running stuff in screen or nested screen. And different layers catching different bits.

Oh. And what happens when you hit ctrl+s...

Show threadKimAug 26, 2024
@quixoticgeek @b0rk I've seen unfamiliar users caught out by an accidental Ctrl-z, if that counts?
Show threadThomas A. FrederiksenAug 28, 2024
@quixoticgeek @b0rk Even worse: ctrl+[ isn’t possible on a number of non-English keyboard layouts as [ requires modifier keys.
Show threadPulkoMandyAug 26, 2024
@b0rk running a thing that generates a lot of output (cat of a large file for example) in a slow ssh connexion. Control+C will work, but the program has already queued a lot of things to send before it will actually give you your prompt back, so it can take a long time to download and display all that output
Show threadrobrykAug 26, 2024

@b0rk

Ending up with screen-inside-screen and having to figure out how to detach the inner one.

Having a program leave the terminal in some weird state when killed (either without echo, or in that weird alternate charset mode that can be fixed by _outputting_ ^O).

Not having job control at all (i.e. can't kill or suspend anything that I start in foreground) in some kinds of emergency shells (probably due to something like http://lists.busybox.net/pipermail/busybox/2002-June/006397.html).

Problems with terminals that are misconfigured so that control sequences are misinterpreted (most recently I had the issue when sshing to something that didn't understand `TERM=rxvt-unicode`).

[BusyBox] re: CTRL-C over serial console

Show threadÖlbaumAug 26, 2024
@b0rk I learned in one off your other threads about a way to “detach” a process after putting it to the background, so that closing the window does not kill it, but I forgot the term (which means I didn’t really learn.) it was counterintuitive, as it often is. Something like orphanise or some crap.
Show threadJulia EvansAug 26, 2024
@oscherler disown?
Show threadÖlbaumAug 26, 2024
@b0rk Thank you.
Show threadWyatt (🏳️‍⚧️♀?)Aug 26, 2024
@oscherler nohup or disown maybe?
disown isn't POSIX but it's often used in bash and ksh
Show thread🆘Bill Cole 🇺🇦Aug 26, 2024
@b0rk Hung NFS mounts on some systems (Solaris at least thru 10, older Linux) will get anything looking at them hung hard enough to not respond to ^c or anything else, even a KILL signal from other programs. So anything like df or ls is a black hole.