Ask Ubuntu General Room

reversiblean

06:52

RBENV_ROOT="${RBENV_ROOT:-$(rbenv root)}"

what does this command do?

SOME_VAR="${SOME_VAR:-$(rbenv root)}"

Ubuntu Questions on U&L

09:35

0

Q: linux - List partition labels of partitions residing inside a raw IMG file without mounting the IMG file

I have a multi-partitioned IMG raw disk file and I want to list the partition labels of each partition without mounting it. The command fdisk -l nearly works as I want but does not list the labels: fdisk -l test.img Disk test.img: 200 MiB, 209715200 bytes, 409600 sectors Units: sectors of 1 * ...

Eliah Kagan

12:47

@reversiblean ${RBENV_ROOT:-$(rbenv root)} behaves like $RBENV_ROOT if its expansion would be nonempty, and behaves like $(rbenv root) otherwise. It works in any POSIX-compatible shell.

Ionică Bizău

13:19

Hey! Just wanna say thanks to @Fabby once again for helping me to recover the content from a corrupted SSD. It was a painful process, but the very first impression is that almost everything is in place––at least the important stuff. I opened a bounty to reward Fabby here: askubuntu.com/a/802056/148451

Journeyman Geek

14:17

ooh

'd use something different but if it works.. ;p

@TheWanderer dark matter :(

though it might maybe end up as a coming again

Fabby

14:56

@IonicăBizău 500??? Woohoo! Did you get all your files back???

@JourneymanGeek No; It was a technical help session here

Journeyman Geek

ah

TheWanderer

@JourneymanGeek I thought the plan for that was either a radio season or graphic novel.

Fabby

@JourneymanGeek But instead of him having to post en entirely new question, he offered a bounty on one of my existing answers and I told him "Go here and start using that solution so you will never have to do file recovery in the future any more..."

/shrug

cl-netbox

15:29

Hello :)

Good afternoon @Fabby ! :) Last day of your holidays today ?

Ionică Bizău

@Fabby I did lose some of them, nothing important so far. I have the cloned partition on the HDD, just in case. Yes, 500! :) I thought I'd never get anything back from that SSD.

vidarlo

0

Q: command to install ubuntu from usb

I currently have Q4os installed. What command can I use to install Lubuntu from files on usb? I can't boot install from usb and mini install doesn't have wireless internet installed.

command-line

this should IMHO be reopened, as none of the duplicates listed disucess debootstrap which may be used to bootstrap ubuntu or debian from a running Linux system

If reopened I will make a answer about debootstrap

Eliah Kagan

Would such an answer not be appropriate on either of the questions it's listed as duplicates of?

vidarlo

no

it's not about installing from network, nor booting from a usb medium with a non-ubuntu system

it's installing ubuntu from within e.g. debian or opensuse

and the question is not a duplicate of either of those questions

Zanna

oh I am an idiot

5

Eliah Kagan

15:43

@vidarlo You're right. I was just clicking reopen but it looks like Zanna's taken care of it. :)

vidarlo

:)

Zanna

who tagged that question command-line!!??! tries to pass the blame on to others

vidarlo

@Zanna :}

Eliah Kagan

@Zanna But you weren't one of us who wrongly closed it. I was, but you weren't.

Oh, you mean you're thinking maybe you shouldn't have hammered it open because maybe it's not really a command-line question?

Zanna

I should at least have edited it first which would have included removing the unreasonable tag

I would definitely have voted to reopen it...

@EliahKagan yes exactly

although... I don't know what the title of that question should be... @vidarlo can you suggest something more descriptive?

Eliah Kagan

15:47

I've retagged it and also retitled it but maybe it can be retitled again.

Also, is it an XY problem? Why can't they "boot install from USB"? Perhaps a fix for that would fix the problem.

vidarlo

@EliahKagan I agree the question is not good quality.

Eliah Kagan

@vidarlo I think you should still go ahead and post your debootstrap answer if you think it's useful, though.

Zanna

@EliahKagan that's a lot better

vidarlo

but the close reason was plain wrong :}

Eliah Kagan

Or we (I and the other people who VTC'd it) picked wrong dupe targets anyway. Sorry about that!

Zanna

15:52

someone wanting to post an answer influences me very much towards wanting to reopen/not close if those things are reasonable

Eliah Kagan

@Zanna I'm not sure the command-line tag was totally wrong for it. The OP correctly recognizes that there's probably no reliable way to use a GUI tool to carry out the whole installation from within another OS, so the remaining methods are command-line based. We might even want to put the tag back.

I only removed it because it badly needed some other more important tags, so I was editing it, and you said it shouldn't be tagged that way, and your gold command-line badge means you probably know what should and shouldn't be tagged command-line, so I figured you were probably right. :)

Zanna

haha I had a similar thought when I started editing. I think it would be reasonable for it to have that tag after all

vidarlo

heh

actually quite a lot of fiddling to get debootstrap to work

Eliah Kagan

Perhaps @Videonauth would be interested? I know he's written some stuff about debootstrap.

vidarlo

@EliahKagan ah. Ubuntu's own documentation is wrong at least :]

help.ubuntu.com/lts/installation-guide/powerpc/apds04.html

Zanna

16:08

:o

Eliah Kagan

Have you identified what would need to be changed to fix it? Those pages aren't wiki-editable, but there should be a project on Launchpad against which bugs can be reported.

vidarlo

@EliahKagan they will work if you're running from ubuntu

@EliahKagan but otherwise you have to specify a mirror and so on

TheWanderer

16:30

Is it a good or bad sign if the students at Binghamton are using Gedit and Terminal to build C++ programs?

vidarlo

it's a bad sign

sane people would use emacs

TheWanderer

>_>

No sane person would program exclusively from the CLI

Eliah Kagan

@vidarlo Agreed, but you have misspelled "vim" in a very odd way.

TheWanderer

I'm tempted to see if I can reboot to a root shell...

vidarlo

@EliahKagan vim is certainly a strange way to spell emacs, I totally agree.

Eliah Kagan

16:34

:)

TheWanderer

Why does vim not use any standard key shortcuts?

It seems like it's just being different to be different

Eliah Kagan

It prefers to be modal.

vidarlo

That's the reason we have many consoles

so we can do an alt-f2 and killall -9 vim

Eliah Kagan

@TheWanderer In all seriousness, though, if you mean they're being instructed to use that, I don't know, but I don't think there's anything wrong with writing C++ in Gedit and compiling it in a terminal. Gedit has syntax highlighting for C++. It's fine to use an IDE, or an editor like Vim or Emacs either graphically or in a terminal, or an editor like Gedit. For simple programs, it's fine to compile them with a build system but it's definitely also fine to just run the compiler directly.

vidarlo

@EliahKagan totally agree. A build system is a topic of its own right, and not needed at beginner level programming

TheWanderer

16:36

The guy in front of me has multiple classes, packages, and even some CSV

I'm also still pretty sure I can just reboot to a root shell

TTY isn't blocked

@vidarlo KDE FTW

Byte Commander

Eh, pretty sure you could

would be hard to lock that

vidarlo

@TheWanderer you notice my avatar. Care to guess my DE? :P

Byte Commander

doesn't change that you're still probably not allowed to do that on what sounds to be a school computer

TheWanderer

@ByteCommander these are connected to the domain o_O

Seth

@vidarlo Your DE is simply a fullscreen YaST :P

Eliah Kagan

16:38

@vidarlo I think there are some benefits of using an IDE at the introductory level. If the IDE integrates with a debugger, then students can easily see how control flow works. In many cases, an IDE can figure out the types of expressions and show them. But I think there are benefits of not using one, too. I'm not sure either approach to beginning to learn C++ is objectively better.

TheWanderer

I don't think it would be that hard to do some nasty stuff without being caught

vidarlo

@ByteCommander I was mildly chastised for reinstalling windows 2003 server on a school computer running windows xp. Schools clearly have different rules regarding computers :P

Byte Commander

Haven't seen a useful C debugger yet

printf FTW

TheWanderer

C++ not C

vidarlo

@seth zypper actually beats the pants of apt when it comes to dependency resolution imho

TheWanderer

16:39

@ByteCommander also yes

Who needs breakpoints?

Scrubs, that's who

Eliah Kagan

@TheWanderer std::printf :)

Seth

@vidarlo 'twas only a joke. OpenSUSE is my distro of choice outside of Ubuntu :)

Byte Commander

GNU/printf

wait, no

TheWanderer

I was told never to use printf in C++

Seth

@ByteCommander gdb?

vidarlo

16:40

@TheWanderer breakpoints? You mean system("c:\windows\pause.exe")?

Byte Commander

yikes

TheWanderer

O_o

vidarlo

@seth no offence taken ;)

TheWanderer

Ew European English

Nce, ise, our

vidarlo

askubuntu.com/questions/1027046/… - @zanna I think command-line is an ok tag on that :P

Zanna

16:46

haha sure

vidarlo

the interesting thing is that it actually booted. At least in virtualbox :}

Eliah Kagan

So should I put the command-line tag back?

I failed to capitalize Ubuntu in the title before, so I should probably edit it again anyway.

Zanna

@vidarlo w00t

vidarlo

@zanna ?

Zanna

I mean, awesome, it booted

sorry

vidarlo

16:56

-1

Q: How do i run a simcity game?

i'm wondering about simcity how to download and install simcity mod apk? simcity is an amazing game but i'm unable to download and install it mod.

games

spam

Byte Commander

not sure

Eliah Kagan

To be safe I've downvoted it and voted to close it as off-topic instead. (I also commented.)

And I flagged it VLQ. We'll see how that goes. :)

That migration was quick!

Byte Commander

Ah, look at their other two posts

all link to some *.apk website

eh...

I think that migration was...

Eliah Kagan

Oh, yeah. They're a spammer. So it should be flagged as spam on Android Enthusiasts?

vidarlo

@EliahKagan yeah, it's spam without any real doubt

Eliah Kagan

17:00

We can flag this one on AU too then.

Ubuntu Questions on U&L

0

Q: Broke display settings on Ubuntu, how should I fix this?

I was messing around with my Nvidia Settings for my dual monitor setup. I changed my second monitor to be on a new X display and restarted my computer. Now whenever I click ubuntu in GRUB it just shows me a purple screen on my main display, blank on my other displays. I can't open terminal with c...

ubuntu login nvidia display

Eliah Kagan

This answer of theirs is also blatant spam.

vidarlo

I'm wondering how much malware there's in those apks

Eliah Kagan

I've flagged the migrated post as spam on Android Enthusiasts and, because of the somewhat unusual situation (typically a post of such low quality would not be migrated), I've commented to clarify why it appears to be spam.

So, if a migrated post is deleted as spam on the destination site, does that reject the migration the same way as a non-dupe closure would, and then the post would be unlocked here?

Byte Commander

probably

Eliah Kagan

17:09

Okay. Well, we can flag it again here if that happens.

Byte Commander

got deleted on android just now

Eliah Kagan

Good.

Byte Commander

The migration redirect from the AU link is still intact, leading to an android 404

so maybe it won't come back...

Eliah Kagan

It does still exist on our site. I've flagged it as spam.

I can cast a third delete vote if people are, for whatever reason, uncomfortable flagging it as spam. But given their other posts, I don't think there's any doubt.

Byte Commander

gone

Eliah Kagan

17:15

Ah, good.

Videonauth

I hear debootstrap?

vidarlo

what happens to users that spam? Do they loose the ability to post?

@Videonauth yeah.

Videonauth

whats the problem?

vidarlo

@Videonauth askubuntu.com/questions/1027046/… why do you assume it's a problem? ;P

Eliah Kagan

@Videonauth I figured you might be interested.

Videonauth

17:19

nobody i Know asks about debootstrap and has no problem ;)

2

Byte Commander

@vidarlo first, there's a 100 rep penalty per post. Dunno at which point automatic bans come into action. Normally a mod would destroy the accounts at some time manually.

vidarlo

@ByteCommander but rep is capped at 1 anyway?

Videonauth

@vidarlo the user need to be in more usergroups as only in his own

Byte Commander

it is

vidarlo

@Videonauth good point!

Videonauth

17:21

and before you chroot you need to bind resources

vidarlo

@Videonauth no, you don't

Videonauth

@vidarlo when did you last do an debootstrap install?

vidarlo

@Videonauth I went trough a install from opensuse and booted the result in virtualbox

to write that

without bind mounting

Eliah Kagan

You don't always need to bind resources for chroots in general, but I'm surprised if a full deboostrap install works without doing so.

Videonauth

did you read my instructions eliah posted?

@eliah on ubuntu is doas not work

Eliah Kagan

17:22

@vidarlo Yeah. Users with few upvotes posts are already more vulnerable to being question-banned or answer-banned automatically by the system, though, so I think it more than evens out. I believe an actioned spam flag carries more a of a penalty, in that regard, than any other single event.

vidarlo

@Videonauth ok, interesting, I will have a look at what you wrote :)

Videonauth

i just installed 18.04 per debootstrap about 3 weeks ago

Eliah Kagan

@Videonauth Attempting to install using debootstrap after chrooting in without doing any bind mounts? I'm not sure why that would work on other GNU/Linux systems either.

Videonauth

and i found even a new way to use this debootstrap to create EFi installs

Byte Commander

@Videonauth Btw, on your blog you recommend installing gksu for gksudo gparted - there's a wrapper gparted-pkexec that should be used instead on Ubuntu.

Videonauth

17:24

@EliahKagan debootstrapping is not the problem without binds but making installs like desktop UI and rest you need to put diversions and binds otherwise you have no internet connection etc

Eliah Kagan

Ah ok.

Videonauth

@ByteCommander yes, worte that before this wrapper existed i believe

vidarlo

@Videonauth Updating with bind mounts and making a community wiki answer :)

Videonauth

@vidarlo for makinf it EFI bootable you ned to alter my procedure by a few steaps

1. create about 1ßß MB EFI vfat 32 partiotion, and bind that under mnt/boot/efi

and install grub-efi-64bit or how the package is called

before you install the kernel

thats all :D

only one thing to find out for me right now is, how to make a multibootable version which can boot on legacy or on EFI

vidarlo

mm, was a bit surprised at how streamlined it was

Videonauth

17:28

i love installing with debootstrap, it keeps your system far more clean as the standart ubuntu install

vidarlo

@Videonauth but what I did was mount /sys and /proc inside the chroot - and the result booted :)

Videonauth

sure you can go and install metapackages for the desktop and even then you have less clutter

vidarlo

I typically start with a minimal install

Videonauth

you can try on an USB stick if you want

vidarlo

and apt-get whatever I need

@vid

Videonauth

17:31

as normal

vidarlo

@Videonauth I've never tried the graphical ubuntu installer actually :)

Videonauth

cool thing on debootstrap is, if you know the repository names you can even install kali or debian this way

vidarlo

yep

Videonauth

btw the same procedure is used for arch too but called there pacstrap

vidarlo

how is cross platform support?

Videonauth

17:34

how you mean?

vidarlo

would it be feasible to make for instance an arm image from x86?

or would you have to use bochs or similar?

Videonauth

@vidarlo yes but stressy

you can set up an amd64 (64-bit) system to crosscompile, and then you would have to build every package for arm

kernel itself is very tricky to compile for arm on an non arm chip

doable but tricky

never tried that yet tho

vidarlo

interesting :)

Videonauth

i learned alot about how the system is set up etc while fiddling with arch

Seth

hmm. I have a super old graphics card lying around, but it's Nvidia. Anyone know if it would cause problems if I put it in my newer desktop with my existing radeon card to power the 2nd display?

vidarlo

17:45

@seth totally different kernel modules, so I see no problems there.

Fabby

@cl-netbox Not really: next week off too! :-) I didn't take many holidays in 2017, so ...

:-) :-) :-)

@IonicăBizău Well, start making back-ups. (sad to hear that you didn't get everyting back)

Sorry for both late replies: I was cooking and eating afterwards.

@Videonauth o/

Videonauth

@Fabby \o/

wait you have holliday? finally some time to get the HDD's done?

Fabby

@Videonauth My 2.5 TB drive was DOA

Videonauth

dang

Fabby

Have to get it replaced, but the SSD is ready

Let me see how long it takes to drive over to you from here...

4h.... I think I'll be sending it.

@Videonauth Deutsche post good enough?

Ionică Bizău

18:01

@Fabby I'm not sure how much was lost, but I did install Dropbox and keeping stuff in sync because I realise my SSD is eventually damaged...

Fabby

@Seth can you move all this to a chat room and inform the user, please?

Ionică Bizău

@Fabby See this chat.stackexchange.com/rooms/76332/…

Videonauth

@Fabby sure, why should it not be enough?

Fabby

@Videonauth I'll send it tomorrow: 80GB more...

Videonauth

yep 128 GB more, i will use the hdd from my laptop then on my main system and my alptop gets the ssd as an upgrade

anyways better to not have conventional hdd'S in laptops

Fabby

18:03

@Videonauth nope... Better to have SSDs in a laptop.

(Ah... "not")

/shrug

Videonauth

yep i see it the same, my laptop still uses an 128 GB hdd

Fabby

@Videonauth Wow... small and beautiful!!! :D

Seth

@Fabby The comments on the question or answer?

Videonauth

yep and for the laptop an ssd will make a huge difference speed wise

Fabby

@Seth Question, please...

Thank you!

Seth

18:07

done

Fabby

:* :* :*

:D

That means that the user will have automatic access to that chat room, right?

(You will not believe me, but I've never done this before with a rep 1 user)

Seems to work!!!

Seth

@Fabby yep!

vidarlo

18:34

0

Q: Printing Questions/Responses in READABLE scale

I've posted about this before. I have the Meltdown/Spectre cpu flaw. I'm trying to update the kernel to a patched version. I found an AskUbuntu page I want to print. Printed at "200" the words scroll off the right edge of the page are are unviewable, let alone readable. When I set the print to ...

printing fonts text

lol

Fabby

@vidarlo voted to migrate...

@vidarlo Starred! More close votes needed!

vidarlo

19:02

@fabby did so myself :)

@fabby just that the mention of bandwidth was a bit funny. I can see that smaller fontsizes saves band on dot matrix printers :)

Fabby

I know: the bold was to attract others

@vidarlo :D :D :D

vidarlo

:)

Fabby

19:16

4 close votes!

Ionică Bizău

~~Closed~~ Migrated :)

Fabby

:D

Mersi!!!!

Ionică Bizău

Haha :D

Fabby

That's the only Romanian I know...

Ionică Bizău

See? it's very close to the French version merci :)

Fabby

19:17

I know...

Ionică Bizău

Romanian, French, Spanish and Italian have a lot of similar words

Fabby

Used to work a lot with Romania about 1.5 years ago.

Ionică Bizău

Ah, really? What companies?

Fabby

let's take this somewhere else...

Ionică Bizău

Gotta go to bed now

See you!

Ask Ubuntu Meta

19:32

0

Q: Printing Questions/Responses in READABLE scale

I've posted about this before. I have the Meltdown/Spectre cpu flaw. I'm trying to update the kernel to a patched version. I found an AskUbuntu page I want to print. Printed at "200" the words scroll off the right edge of the page are are unviewable, let alone readable. When I set the print to ...

discussion

Fabby

It's never too late to unstar anything!

Eliah Kagan

I thought the system didn't allow us to remove our stars after some amount of time.

Fabby

Yeah, that's what I'm grumbling about...

@EliahKagan SET IGNORE_MODE="Fabby"

>:-) >:-) >:-)

Eliah Kagan

Ah.

@Fabby Right.

Sorry.

:)

Fabby

@vidarlo why did you convert this to a community answer?

No more rep for you now...

vidarlo

19:42

@fabby to encourage others to chime in :)

@fabby rep is not that interesting

Fabby

I dunno enough about debbootstrap

vidarlo

Above 2k is enough. No more waiting for edits to apply

:)

@fabby I felt that the process of using debootstrap is very wide, and with @Videonauth's expirience and interest, it may become a canonical Q&A for debootstrap with a few revisions :)

Fabby

@Zanna Good to know I'm not the only one...

Videonauth

lol

Zanna

donkeys are awesome though

Fabby

19:45

They are:

much more sturdy then horses and can carry more weight in the mountains.

(where my family lives; they still have one though it doesn't do much work nowadays)

vidarlo

prefers gnus

3

Zanna

they are really smart too

Fabby

Yup... and they know who beats them and who feeds them.

@ThomasWard What I thought about in the meantime: if you upgrade your pipe, you might have to upgrade your router/switch too.

most of them can't really do 1Gbps.

vidarlo

@fabby most switches can do 1Gb/s

as for routers... as long as you don't try to anything fancy, a lot of modern consumer routers will handle it. A mediocre x86_64 will also handle it

Fabby

20:03

@vidarlo Most consumer 50$ router/switch combos will not.

Thomas Ward

21:10

@Fabby my modem and my router and equpiment are full gig capable

dont' forget I don't use consumer-grade equipment

my network is Enterprise-grade equipment

gig switches, gig connection at the border via a virtual pfSense (the line that is the "WAN" and "LAN" and "Wifi/OPT1" are all full gig)

Ebrahim Karimi

Hello

TheWanderer

22:05

@ThomasWard giggity?

Fabby

22:34

@ThomasWard OK, Cool, I didn't know. What are you running then? Cisco?

Just sharing experience with Gbps home networks.

Ubuntu Questions on U&L

23:12

0

Q: Define a Container Per User, Or Create separate Home for each user

I've a scenario like this: 1 Physical Ubuntu Server 16.04 ,16 Core, 32 GB Ram, and a Nvidia Titan X 12GB 4 Console PC for Regular Works and Remote To Server I want to use the server as a deep learning computation server, with some docker containers for individuals who run the codes on server ...

ubuntu nvidia docker xrdp

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Ask Ubuntu General Room