Ask Ubuntu General Room

3:24 AM

0

I currently have a desktop with a gtx 750ti gpu with a i7-4790k processor. I recently bought a second monitor and had it plugged into video card. So one video card was outputting two displays. However, I recently learned that you are able to enable the integrated graphics to support multi moni...

Ubuntu Questions on U&L

4:47 AM

-1

Q: Unable to ping external IP address but able to ping internal IP from that server only

Unable to ping external IP address but able to ping internal IP from that server only. From externally I am able to ping external IP and also DNS. I am able to see my tomcat8 server from localhost/projectname but unable to see same project from public IP on source machine(machine which having tom...

ubuntu networking tomcat

Motivated

6:15 AM

Hello all. What is the difference between tee > output.log and tee output.log?

Motivated

7:07 AM

Hi there. Why is that the command ls .*/ -d produces a different result to ls */ -d?

dessert

@Motivated there is no difference, tee copies stdin to files and stdout

Motivated

And if i run the command find . for example it lists both visible and hidden directories. Why is that so in comparison to ls .*/ -d and ls */ -d?

@dessert There is though. When it's piped to tee > output.log it does not return the output to the screen.

dessert

@Motivated well that’s just design, use ls -a to include hidden files. if you also use globbing (which is normally not necessary!) you may also want to set the dotglob option (shopt -s dotglob), see man bash

Motivated

@dessert The reason i ask is because ls -d doesn't return any results apart from . However ls .*/ -d and ls */ -d albeit there are different

dessert

@Motivated yes, it’s stdout that’s displayed in the terminal, if you redirect it there’s nothing to display

Motivated

7:17 AM

@dessert Do yo mean to say in all scenarios > doesn't display to screen?

dessert

@Motivated how so? I don’t have your directory here…

Motivated

@dessert If i am in the home directory e.g /home/user and if i run the command ls -d it only returns . If i run the command ls .*/ -d it returns . .. .cache/ etc

dessert

@Motivated no, there’s also stderr, you’d need &>file to redirect every channel

Motivated

@dessert If if run the command ls */ -d it returns Desktop Downloads, etc

@dessert My understanding is that if i have 2>&1 > output.log it only writes stdout and not stderr.

dessert

@Motivated -d is to only “list directories themselves, not their contents” – what were you expecting?

Motivated

7:24 AM

@dessert I would have expected the list of directories i.e. Desktop Downloads, etc. I wouldn't expect the contents contained in the directories based on the description

@dessert - If i run the command ls ./ followed by 2 tabs it lists all the possible options hence i would have though that if i run the command ls ./ -d it would list all the directories

dessert

@Motivated but those directories are contained in your current working directory :)

Motivated

@dessert Sorry dessert. I don't follow.

dessert

@Motivated you run ls -d, it returns the current directory and not its content, thus it returns .

Motivated

@dessert Do you mean to say that the Downloads Desktop directories are considered to be content?

dessert

@Motivated exactly, a normal ls call simply displays the current working directory’s content

Motivated

7:40 AM

@dessert Righto. That's a bit clearer. So what does ls .*/ -d in comparison to ls */ -d mean in the context of current directory?

@dessert - Do .* mean list all files that start with .? Does */ mean all files that end with /?

dessert

if you run ls -d */, the glob expands to every directory in the cwd, thus you effectively run ls -d Desktop/ Downloads/ … and ls now returns every single one of these without returning its content (-d)

@Motivated */ expands to every directory

.* in the context of shell globbing (don’t mix it up with regex!) means every file (and directory) starting with a dot

Motivated

@dessert Are there differences in shell globbing and regular expressions?

dessert

if you run ls -d .*/, the glob expands to every directory beginning with a dot in the cwd, thus you effectively run e.g. ls -d .angband .cache .certs … and ls returns every single one of these without returning its content

@Motivated they are totally different, yes

Motivated

@dessert Ah. I wasn't aware of that. Do you mean so say i can't use regular expressions with the shell?

dessert

@Motivated er… not with the shell itself, yes. there are however commands understanding regex, take grep and find -regex as examples, but that has nothing to do with the shell

Motivated

7:50 AM

@dessert That was very helpful. Thanks for clarifying that.

dessert

talking about bash here, I’m not sure about other shells – I wouldn’t be surprised if zsh would understand regex natively or with a plugin.

Motivated

@dessert That makes sense.

dessert

@Motivated I’m glad to be of help. :)

Motivated

@dessert - I do have another question. Do distributions for example such as Debian and Fedora maintain copies of packages e.g. .deb and .rpm once it has been installed?

@dessert It was very insightful.

Rinzwind

I got a 10+ upvotes in a matter of minutes just now.

Motivated

8:00 AM

@Rinzwind That's great. What was it for?

Rinzwind

@Motivated /var/cache/apt/archives/

@Motivated not really ;-) it tends to be a serial upvoter. Those get banned and the upvotes reverted.

Motivated

@Rinzwind I didn't think there was support for serial up voting.

dessert

@Motivated AFAIK, package management software like apt downloads the package from the server, extracts it to install it and leaves the package file there, there’s apt clean to remove those files (and an equivalent for Fedora I suppose)

Motivated

@dessert Interesting. In an attempt if it does, i ran the command find / -regextype posix-egrep -regex '.*/[a-zA-Z0-9\.\-]+\.rpm' (it's a derivative of Red Hat) and none are found.

Rinzwind

@dessert /var/cache/yum ;-)

dessert

8:07 AM

@Rinzwind I meant for apt clean specifically

Motivated

@Rinzwind So why does find not display it?

dessert

@Motivated try find /var/cache -name "*.rpm"

Motivated

@dessert Is there any reason as to why it won't work if i start at / to find the files in any location?

dessert

@Motivated I suppose the regex is faulty. :)

Motivated

@dessert Or none exist :-)

Rinzwind

8:15 AM

@Motivated it is a cache so could be cleared by you (or the system if Fedora has a procedure for that; Ubuntu does not ;-) )

Motivated

@Rinzwind Interesting. It appears in reading on zypper it deletes it on installation of the package.

Rinzwind

The dir should exist though :)

Motivated

@Rinzwind Yes it does. It's empty.

@dessert On the question of tee > output.log and tee output.log, is the only difference that when using a redirect with tee it won't print to screen. My understanding is tee streams to stdout.

Rinzwind

@Motivated "My understanding is tee streams to stdout" and to the file.

Motivated

@Rinzwind That's what i thought however tee > output.log doesn't stream to stdout. It only redirects to the file.

Rinzwind

8:25 AM

@Motivated oh that last past is about "tee output.log"

that does stdout and the file

Motivated

@Rinzwind Righto.

dessert

8:57 AM

@Motivated if you don’t specify a file tee can stream to, it only outputs to stdout. that’s what’s happening in tee >file, it does output to stdout, just that the shell redirects this output to a file instead of printing it in the terminal. redirection like that is a shell operation, tee has nothing to do with it, doesn’t see the filename and frankly doesn’t even care what you do with its stdout. ;)

Ubuntu Questions on U&L

0

Q: Does Transmission traffic go through Sshuttle tunnel?

Firstly we got sshuttle running in my ubuntu terminal, sudo sshuttle -r root@104.140.00.200 0/0 --dns --python=/usr/bin/python3 -x 104.140.00.200 The torrent file is downloaded by Transmission and the download speed nearly reached the ISP brandwidth, 90 times faster than my web browsing ...

ubuntu ssh transmission

dessert

@Motivated in tee file on the other hand, file is an argument to tee and treated like explained in the manpage, as an output file. tee’s output to stdout again is not affected by that, you may specify none or one or 50 filename arguments and tee still outputs stdin on stdout, which the shell will simply print if you don’t command it do to something different like redirecting, piping or the like.

dessert

9:54 AM

> Synpatic Package Manager

(source) Can we rename it to “Sympathic”? :)

Ubuntu Questions on U&L

10:21 AM

-1

Q: Can't create bootable USB with WoeUSB

When I try to create a Windows 10 bootable USB on my Linux Ubuntu 18.04 with WoeUSB it gives me this error: Installation failed! Exit code: 256 Log: WoeUSB v@@WOEUSB_VERSION@@ ============================== Mounting source filesystem... Error: File "/media/woeusb_source_1548324574_1839/sources/i...

ubuntu usb bootable

PerlDuck

11:03 AM

I'm a bit upset. Today this question came in https://askubuntu.com/q/1112458/504066 from a "new contributor" (member since today). I'm perfectly sure that I already answered that (or almost the same) question to a user with the same name a couple of days ago.

Looking into my history, I cannot find my answer any more. Now I believe that user simply deleted their old question and created a new account to pose the same question again.

Is there a way to view my deleted answers? It was definitely in 2019.

Videonauth

11:29 AM

@PerlDuck yes there is a way to see all your answers which got deleted back till account creation, i hope i have the bookmark still to my old stuff then i can tell you how to do a search on the page

@PerlDuck askubuntu.com/search?q=deleted%3A1

This search only shows stuff you own which got deleted

dessert

11:46 AM

@Videonauth nice – why doesn’t askubuntu.com/help/searching mention the deleted operator?

Videonauth

@dessert hidden features :P

not sure if newcome users could see their own deleted stuff even

dessert

use deleted:1 is:answer to only return answers

PerlDuck

@Videonauth @dessert I used user:me is:answer deleted:1 but it only shows answers that are not deleted. Seems to work only for 10k+ users :-(

The "deleted:1" has no effect for me.

Videonauth

ow well

dessert

@PerlDuck contact a mod, if your answer was deleted although it was helpful a mod should undelete the whole question IMO

PerlDuck

12:02 PM

@dessert Thank you, I'm not interested in undeleting it. The OP doesn't deserve it. They didn't comment or say whether it worked or not but just repeated the question in comments to the question without actually clearing things up.

I was just curious whether I really wrote an answer or just dreamt of it ;-)

@dessert With this pattern user:504066 is:answer created:2019 score:-1..1 deleted:1 I get 4 of my posts (all of which are active) but the deleted one doesn't show up. Never mind.

terdon

@PerlDuck you don't have any recent deleted answers. The most recent one is from November 9th.

dessert

@PerlDuck I suppose you miss askubuntu.com/help/privileges/moderator-tools

terdon

No other user with the same name has any relevant question. And there were no comments on the question you linked to either, so it looks like you're remembering something else.

Could you be thinking of your answer here?

0

A: Split zip into smaller zip files

You need zipsplit which is part of the zip package: zipsplit -n $(( 250 * 1024 * 1024 )) your_zipfile.zip It splits an existing zipfile into smaller chunks. The size of each chunk can be supplied via the -n switch. It defaults to 360000 because years ago floppy disks had a capacity of 360 kB. ...

PerlDuck

12:20 PM

@terdon Thank you all for the effort. I am maybe really remembering something else.

And no, it was not the zipsplit answer. It was about split and some parameters like --additional-suffix, --numeric-suffixes and such.

@dessert Indeed. approx. 4,000 more "internet points" to go ;-)

dessert

@PerlDuck maybe on another site in the network?

PerlDuck

@dessert That's what I thought then, too, but again no luck. There's a view that shows all my posts on all sites and the one I miss wasn't there.

dessert

@PerlDuck mysterious. are you a sleepanswerer? :)

PerlDuck

@dessert Hey, I again had a look on U&L and (despite my 128 rep there) I can see my deleted posts there ... et voila! There it is: unix.stackexchange.com/q/495484/251553

dessert

hooray :) I can’t see it, but it’s nice (and a bit strange) that you can.

PerlDuck

12:30 PM

@dessert I think I can see it because my own answer was deleted.

Ask Ubuntu Meta

0

Q: help/searching doesn’t mention the `deleted` operator

There’s a boolean operator for the search that’s not mentioned on the searching help page: deleted: yes/true/1 returns only posts that have been deleted; the default no/false/0 excludes deleted posts from the search. This operator does only return your own deleted posts regardless of the user o...

feature-request searching help-center

2

dessert

@PerlDuck sounds reasonable

PerlDuck

TIL: Better stick to one site in the network. :-)

dessert

feature-requested it :>

Rinzwind

1:40 PM

and again. someone is serial upvoting. I got 10 upvotes in a matter of minutes

Terrance

Aren't bug reports still off topic? askubuntu.com/questions/1111742/…

And where is it stated that the recommended way to file a bug is through Debian first?

If that were the case, we would be filing all bug reports through Debian first then. So, if this is getting reopened, does that mean that we are going to change the rules then of how to file a bug report in Ubuntu?

Rinzwind

2:28 PM

YES

BUT! If a bug can be answered with a fix it is advised to post an answer @Terrance

Terrance

@Rinzwind True, but where does it state that bugs are supposed to be done to Debian first for Ubuntu packages?

Rinzwind

he is wrong

Terrance

That's what I thought

Rinzwind

it is the Ubuntu teams task to contact upstream

I would believe you need to post a bug on LAUNCHPAD

Terrance

Agreed!

Aaaaand, he's still not getting it.... Hrmmmph

Rinzwind

2:36 PM

I added a comment

haaaaaa -> @Terrance help.ubuntu.com/community/reportbug

Terrance

Thank you!

@Rinzwind WOW! That needs to go. Since 4.10?

Rinzwind

note the "since 4.10" _O-

yeah

Terrance

I will remove all my comments, but I am still very much against reporting bugs to Debian first for Ubuntu packages.

I guess it is his own note taking system. I guess that is fine. Voted to reopen.

Terrance

3:01 PM

But, I did add a note to OP in that question.

Terrance

3:29 PM

Now this is more on topic. askubuntu.com/questions/1111742/… =)

Motivated

3:42 PM

@dessert Thanks dessert. What do you mean by "doesn't even care what you do with its stdout"?

@dessert I didn't realize that tee did not require a file to be specified. What do you mean by "tee still outputs stdin on stdout,"? What is the stdin? Would it be the syntax on the left of the pipe?

Motivated

4:09 PM

@Rinzwind - I'm unclear on the use of pv. Would you mind helping?

dessert

@Motivated exactly, e.g. the string “test” followed by a newline character in echo test | tee >file. in this example, tee is totally unnecessary, as it just assigns its input (stdin) to its output (stdout), which is then redirected to the file file by the shell. echo test >file would do the exact same without the unnecessary tee call.

@Motivated I meant that tee has nothing to do with the redirection, that’s the shell’s business.

Motivated

@dessert That's heaps clearer now. Thanks. I was wondering why it wasn't streaming content to the screen/display.

@dessert I wasn't aware that redirection was a shell function.

@dessert - Would you mind helping me understanding the use of pv? It's unclear. I believe pv can read and write data as well.

dessert

@Motivated I can nothing but recommend reading man bash/REDIRECTION to learn about it, it’s really worth it!

@Motivated sorry, I have to get back to work…

Motivated

@dessert All good. When you do have a break or get the opportunity, that would be awesome.

dessert

@Motivated There’s much more information needed to be able to help you: What exactly are you trying to do, what doesn’t work and what’s unclear? Give an example of what you’re trying to do. Did you read posts that use it, e.g. askubuntu.com/questions/215505/…?

Motivated

4:25 PM

@dessert Sure. The example i am looking at pv access.log | gzip > access.log.gz. I don't understand why the syntax is pv access.log at the start.

terdon

@Motivated Please don't ping specific people for a question (unless you're continuing a previous conversation, of course). Just ask and if anyone can and wants to answer, they will.

Motivated

@terdon Sure terdon. I'll bear that in mind.

terdon

Do you know what pv does?

Motivated

@terdon I have an understanding. My interpretation is that it displays the progress of the time it takes for an action to complete as well as a view of how quickly or slowly the action is performing. The syntax is however confusing as per my example of pv access.log | gzip > access.log.gz

terdon

5:08 PM

@Motivated Sorry, I was in a meeting. So, what exactly is it that is confusing you?

The syntax is pretty standard: commandName inputFile

Have you read man pv?

Motivated

@terdon All good. I don't understand why it's pv access logs | gzip access.log.gz. Why is not gzip access.log.gz | pv

terdon

@Motivated Have you read man pv?

Motivated

@terdon Yes i have and the composition of the construct is confusing. I have read other sources too.

terdon

Did you see this section:

   pv  will  copy  each  supplied FILE in turn to standard output (- means standard
   input), or if no FILEs are specified just standard input is copied. This is  the
   same behaviour as cat(1).

Motivated

@terdon To clarify, do you mean that pv copies access.logs to memory and then supplies that as standard input to the next command?

terdon

5:13 PM

So, pv file will simply print the contents of the file into standard output. Meaning that cat file | pv | gzip > out.gz is equivalent to pv file | gzip > out.gz.

@Motivated No, why to memory? It just means it prints each line of the input file.

Motivated

@terdon What does print mean if the file is for example an ISO?

terdon

@Motivated The same thing. The contents of the file are irrelevant. Why would you expect it to make a difference? All files are just data.

No matter what the file contains, cat (and pv) will open the file, start reading it and print out whatever they read.

If that file is an ISO, then you will see things you cannot read. So cat foo.iso will produce what looks like nonsense to a human. However, cat foo.iso > bar.iso will produce an exact copy of foo.iso. Basically, cp file1 file2 and cat file1> file2 are equivalent.

Motivated

@terdon Does it not read the file into memory and produce the output?

@terdon - If yes, that tells me that pv is copying the file into memory and providing that as an input to the next command in the pipeline.

Rinzwind

@terdon ohayo

and terdon explained it as well as I can :+)

terdon

o/

@Motivated It presumably reads each character into memory, but not the entire file. If it did, trying to cat a file that is larger than your RAM would crash your machine.

Rinzwind

5:27 PM

did england sink into the northsea yet?

terdon

@Motivated No, it's telling you it is printing. Why do you think it is being copied to memory?

@Rinzwind Still waiting.

Rinzwind

Theresa May has a plan B... she did s/A/B/g; :D

terdon

pretty much :)

Rinzwind

someone at work asked how to use replacing in vim so I used that as an example

terdon

@Motivated the basic idea of cat is: read a character; if this character is not the end of the file, print that character. If it is the end of the file, exit.

And that repeats until the end of the file. No need to ever hold more than one character in memory.

Ubuntu Questions on U&L

5:32 PM

0

Q: Hash Bang and Shell Scripting

Generally, shell scripts contain the following comment at the first line of the script file: #!/bin/sh. According to the researches that I made, this is called hash bang and it is conventional comment. This comment informs Unix that this file is executed by Bourne Shell scripter under the directo...

bash shell-script shell ubuntu

Rinzwind

I like dogs more

terdon

heh

If we're being pedantic, cat actually waits until a buffer is full, so it does keep more than a character in memory, but that's not really relevant to the main point.

Rinzwind

less is more :=)

even schrodinger did not like cats >:)

terdon

@Rinzwind But most is lesser.

2

Rinzwind

lesserer :=)

Terrance

5:34 PM

Dogs for the win! :)

Rinzwind

DFTW! :=)

Terrance

I love coming in on partial conversations! They give me minutes of pure enjoyment! ;)

3

Rinzwind

lol

@terdon can I or can you see who upvoted me today?

I got to 200 today in an hour or so. and not on 1 answer

Terrance

WOW!!! I didn't know software could reset SMART errors that are written into the drive firmware? smallbusiness.chron.com/… sarcasm

LOL

Rinzwind

it creates a log with errors and the FS skips those :P

Terrance

5:44 PM

Media errors are not SMART errors. :)

Rinzwind

in windows they are

:=)

Motivated

@terdon Apologies. Had to step away from the desk. Sure that makes sense. I assume pv works the same way. Is that correct? If yes, it then passes the bit to the next command in the pipeline. Would that be also a fair assumption?

Rinzwind

yes it works the same way

Terrance

@Rinzwind LOL! That is awesome! :D

Ubuntu Questions on U&L

0

Q: installing the Kup backup system on Ubuntu

I am trying to backup the Ubuntu 16.04 using Kup backup system. But I cannot find any tutorial online that can assist with the download and installation process of the Kup backup system https://store.kde.org/p/1127689/ It seems like it has alot of dependencies and needs some files in set before...

ubuntu backup

terdon

5:50 PM

@Motivated yep, that sounds right

So pv file | gzip > out.gz basically uses pv as cat, it uses pv to print each line of the file, then pipes to gzip and redirects to out.gz. But because you used pv and not cat, you also get a pretty progress bar.

$ pv file.log | gzip > ff.gz
 900MiB 0:00:07 [ 138MiB/s] [========>                                   ] 22% ETA 0:00:23

Motivated

@terdon Ah. That's so much clearer now. Thanks. So is there reason for pv to redirect e.g. pv > file?

terdon

@Motivated To save the output into a file. if you just run pv file1 > file2, then you have copied file1 to file2.

Motivated

@terdon Is that only so that a progress of the write can be displayed? If yes, why not pv file > output.gz rather than pv file | gzip > file.gz?

terdon

6:17 PM

@Motivated The two commands don't do the same thing. pv file > out will simply make a copy of the data in file and save that as out, while pv file | gzip > out.gz will also compress.

Rinzwind

6:54 PM

AU broke

ah and back :P

Zanna

7:13 PM

haha I had to clear my cookies - maybe that's what did it :P

Ubuntu Questions on U&L

7:42 PM

0

Q: Recommended mutli-tab terminal

I'm using Ubuntu 18 default setup with GNOME Terminal. I can do New Tab, but I'm not finding a way to name/title an existing tab: there is no Set Title option in the Terminal menu, and I can't find a way to get gnome-terminal --tab --title SOMETHING to operate on existing tab. So is there a w...

ubuntu terminal gnome-terminal terminal-emulator

dessert

8:57 PM

those are mutlis

Zanna

yum yum

they look like vada to me but whatevs

TheWanderer

donuts with a half-assed hole

dessert

made of rice

Zanna

where are you eating this?

I see banana leaf, I feel jealous

@TheWanderer think how much chutney you could get into those...

TheWanderer

what type of chutney

Zanna

9:10 PM

looks like tomato or capsicum

dessert

@Zanna I don’t, got the image from here in reaction to chat.stackexchange.com/transcript/message/48678313#48678313.

I assume it’s curry.

TheWanderer

oh you mean the bowl

pretty sure that's curry

Zanna

nah, it's very probably chutney

TheWanderer

chutney is a pretty generic term

Zanna

bet @JourneymanGeek will agree with me

TheWanderer

9:11 PM

you could probably say curry is chutney if you tried hard enough

Zanna

haha idk, I haven't eaten those things, but they look like they should be dipped in chutney

TheWanderer

Kitchery

or however you spell it

I want some

Zanna

are you talking about this or this or this?

@dessert I think that person is confused about what they want. Or maybe they typed it too quickly. Either way, if I were them, I'd be pleasantly surprised when a snack arrived instead of a software recommendation

TheWanderer

second one

khichuri

kedgeree sounds really good though

Ubuntu Questions on U&L

10:38 PM

0

Q: gdm3 not loading at boot

I am trying to get Symless Synergy version 1.8.8 to autostart when my Ubuntu 18.04 client desktop boots up. I have followed these instructions carefully, but Synergy only starts after logging in. https://help.ubuntu.com/community/SynergyHowto I believe this is caused by gdm3 is not loading on ...