Ask Ubuntu General Room

A.B.

3:01 PM

@ParanoidPanda I don't know :)

Serg

@terdon acknowledging that someone is good-looking is sexist ? Mkay . . .

terdon

@ParanoidPanda I thought you said you were a) a supporter of UKIP and b) a communist. Now you're also an anarchist?

Serg

@ByteCommander ever heard of time command ? for esample time lsblk

@ByteCommander also, buddhism is hot !

terdon

@Serg No, posting comments about "hot girls" out of the blue in a public chat room is not something that women are likely to find welcoming. And there is a difference between hot and good looking as well as a question of frequency.

Byte Commander

@Serg Muru was faster! :)

Serg

3:10 PM

@ByteCommander @muru is always fast, that's why he has the rep he has

muru

and mostly lazy

Serg

@muru well you are doing pretty good job at being lazy with 43k . Tell me your secret

muru

Comments! And moar comments.

user136984

@terdon Yeah, that's me! ;D

user136984

@terdon Eclectic.

Serg

3:13 PM

@terdon mkay , I'll try to keep that in mind . . . still , if a female is good-looking ( which is synonymous with hot ) , there's no reason why that shouldn't be acknowledged

user136984

@terdon: Just be a bit more romantic about it, ok? :P

muru

@ByteCommander graphs! Do add graphs!

Byte Commander

@muru Wait! Closing Firefox now for exacter measurement...

BRB

kos

@ByteCommander I was about to do the same! But watch out that the shell caches stuff, there's a way to prevent it but I don't remember

Serg

OK, so unless anybody has a task for me or a question to answer, I'll go do some other stuff . . .

kos

3:19 PM

(Also I think you're more IO bound there)

A.B.

@Serg search for awk questions on Unix & Linux?

:)

Serg

@A.B. I could do those later . . . I was going to spend time doing a web-training for my job . .. unless there's anything more urgent here on AU . . . .

Byte Commander

@kos sync && echo 3 | sudo tee /proc/sys/vm/drop_caches

A.B.

@ByteCommander this again?

Serg

OK, I'm gonna go train my face . . . .ping me if you miss me . . . .

A.B.

3:25 PM

@Serg I miss you :)

Byte Commander

@kos @muru can you tell me the difference between user and sys in the time output? I understand they have to do with CPU, but detail?

@A.B. This what?

Serg

^_^

A.B.

This cache thing @ByteCommander

kos

@ByteCommander Yes!

user139252

Yay! VPN works on my work's connection! No more pesky proxies for images or anything!

kos

3:27 PM

@ByteCommander I don't remember. @muru?

However real is the important thing I think.

Byte Commander

real is time from start to end, including IO and other processes' stuff.

Serg

@ByteCommander en.wikipedia.org/wiki/Time_%28Unix%29

Byte Commander

If I understand stackoverflow.com/q/556405/4464570 right, I should add user and sys to get the total CPU time.

muru

@ByteCommander userspace and kernel space, I suppose

Serg

there is User time vs system time section

muru

3:29 PM

@ByteCommander It shouldn't make much difference. See a comparison I did long ago: unix.stackexchange.com/questions/153286/is-cmp-faster-than-diff-q

2

Q: Is cmp faster than diff -q?

In a recent AU question on checking whether some files have differing content, I saw a comment stating that if the differing sections didn't matter, cmp would be faster than diff. This SO answer concurs, giving the reason that cmp would stop at the first differing byte. However, GNU diff has -q (...

kos

@ByteCommander However you're so IO bound there. I think they'll perform the same.

Byte Commander

I will just write down real time and the sum of user+sys, I think.

muru

@ByteCommander Use /usr/bin/time, it has an option to format the output

Then you can do the calculation in gnuplot directly

github.com/murukeshm/scratchpad/blob/master/diff-cmp/…

user136984

@kos @muru: How come you two never changed your default pictures?

Serg

20

Q: The meaning of real, user, and sys in output of Linux time command

$ time ./Test real 0m2.906s user 0m2.887s sys 0m0.017s Here is the program code: #include <iostream> #include <map> void func_a() { std::map<int, int> m; for (unsigned int i = 0; i < 10000; i++) { m.insert(std::pair<int, int>(i, i)); } } void func_b() { st...

c++ linux time kernel

muru

3:33 PM

@ParanoidPanda dunno. Never felt the need, and then I got used to it.

user136984

@Serg: Is that a picture of you by the way?

kos

@ParanoidPanda I changed it once, and immediately went back. I don't like changes, and I like green. :D

Serg

@ParanoidPanda yessir , that's me . . . With less beard but still me

user136984

Will you ever update it with your beard? :D

Serg

Maybe . . . I need to take care of my profile a little more . . .

terdon

3:38 PM

@ParanoidPanda More like schizophrenic, really. Any two of those are completely contradictory.

@Serg It depends on how you do it. That sort of thing can make people very uncomfortable. And 8 cases in a single year really are a bit too much :)

user136984

@terdon: Well, the main reason I like UKIP is because of the kippers...

terdon

@ParanoidPanda Careful, kippers are dangerous:

Kipper Joy - Fawlty Towers - BBC Comedy Greats

►

user136984

@terdon: It wasn't the kippers that killed him though! He'd been dead half the night already! Basil just didn't notice! :D

terdon

:)

Serg

My friend , who is CIS major, send me one of her assignments . . . and their professor uses a csh script to turn in the assignments . . . Now, i don't know that much about csh, but I've heard it's not that good for scripting . . .And now I don't know what to think of CIS department . . . .

terdon

3:47 PM

@Serg How old is the prof?

As for why it's bad, read Tom's classic take on it:

faqs.org/faqs/unix-faq/shell/csh-whynot

Byte Commander

Argh! Brother converted pumpkin soup into smoke in the kitchen! :P

Serg

AND THEY ARE PARSING LS IN THE SCRIPT !

Blasphemy !

kos

@Serg I've read an extremely upvoted U&L post bashing csh, so I guess it must not be that good overall

Serg

@terdon I don't know . . . my friend said young

terdon

Also, remember that shell scripts are more of a sysadmin thing than a programmer's thing. I wouldn't be surprised if, say, Jon Skeet wrote bad shell scripts. Conversely, a great sysadmin and shell guru could write crap C code.

Serg

3:50 PM

who is Jon Skeet ?

terdon

@Serg o_O?

366

Q: Jon Skeet Facts

I'm looking for Chuck Norris Facts style answers. In case anyone is curious, this question was inspired by Jon's own comment to this question. EDIT: If you're into cryptography, you may enjoy these facts. Now with official sanction from the powers that be!

discussion community fun

A.B.

@Serg ping, miss you >:)

terdon

He's the most famous user on SO.

Serg

Basically in that class all they do is log in to a RHEL server on my university, write a java program, compile with javac, and run script ProgramName to capture output, and then use that csh script to submit the captured output

@A.B. You thought I was weird for using javac and command line . Whole CIS class is using it ^

@A.B. also . . .awwwww, I missed you too, by the way

A.B.

@Serg a whole class can not be wrong. >:)

Serg

3:54 PM

O_O . . . .

A.B.

But, work in this business some years and remember...

user136984

I just suspended my first user! >:D

user136984

By validating a flag that is.

A.B.

Only five minutes and then... Coffee:)

Serg

She said "CIS isn't CS, they make it simple to understand" I don't know if I should head-desk or just punch myself in the face

kos

3:58 PM

@ByteCommander The graphs!

I'm anxious to see the results.

Serg

I think AU and U&L have made me a bit too . . . spoiled I guess ? I was expecting better from CIS department . . .

Byte Commander

@kos Sorry, but the smoke had priority... :-/

Ronnie Marlow

The Java world? Do you trust it or don't trust it?

user136984

@Serg: Ask a Panda to headbutt you! :D

Ronnie Marlow

Come on their has to be some comments about java!

kos

4:03 PM

@ByteCommander There's always food burning in your house, isn't it? :D

Serg

@RonnieMarlow Well, @A.B. just mentioned coffee . . . is that close enough to java ?

@ParanoidPanda nah, I'm good . . .I'll just go drink some coffee and then do my training

kos

@RonnieMarlow Toc Toc... Who's there?

Long pause

Java.

(C) Stack Overflow

user136984

@Serg: Ah, too late, I already dispatched the Panda headbutting service! >:P

Ronnie Marlow

Java is a an area of discussion espcially in the ubuntu world. Because their is alot of developmental jobs in the field.

Serg

@kos that joke would be better years ago . . .java got a bit faster

kos

4:06 PM

@Serg It's always funny. :D

Ronnie Marlow

Do you trust java. Because I don't. Java 8, Java 9.

Serg

lol nice ^

java ate java 9

Ronnie Marlow

I get on a computer automatically it ask's for java updates. Weekly updates

Serg

@kos well, it always is :D

@RonnieMarlow you must be on Windows . . .

Ronnie Marlow

Ubuntu side is safer, versus windows we all have to agree to that

kos

4:07 PM

@RonnieMarlow Lol, good one

Serg

Also . . .now that I think of it, those instructors with their csh script and ls are so dum-dum. ls is used to show user's directory before submitting the file . . . so . . .they never heard of dot files ? student could cheat and hide something . . .it's just plain ls , not even ls -a or ls -l . . .

Ronnie Marlow

@kos, I use jedit or bluebird

kos

I enjoy Atom. Never tried either though

Ronnie Marlow

hmmm

I never used Atom ide.

Serg

Meanwhile, I am learning vim

I chmoded my nano so I cannot use it anymore, so I only have access to vi

kos

4:14 PM

It's very similar to Sublime, but it's open-source (and free). Also I use it as a text editor, for Java you probably want a real IDE

Ronnie Marlow

What's vim

user136984

 ________________________________________
/ FORTUNE PROVIDES QUESTIONS FOR THE     \
| GREAT ANSWERS: #4 A: Go west, young    |
| man, go west! Q: What do wabbits do    |
\ when they get tiwed of wunning awound? /
 ----------------------------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

kos

There we go. :D

Ronnie Marlow

lol

What Ide is the best? @Serg

Serg

@RonnieMarlow I don't use ide, I use command line text editors and compilers . . .such as gcc or javac. . . . vim is command line text editor . . .it is one of the most well known editors for *nix systems, besides emacs

Ronnie Marlow

4:21 PM

I didnt know that

hmm

Im from the small college's of america. Community College

user136984

@RonnieMarlow: The most popular IDEs are: NetBeans, Eclipse, and IntelliJ.

j0h

I inherited some c++ medical imaging source code it seems to want #include "wx/wx.h"
and #include "wx/wx.h" what should I do I saw some wxwidget stuff in the repos, but im not sure what it is

Serg

Watching a video on social engineering . . . .the scenario they show is a phone call where attacker leverages someone into buying fake antivirus . . . More probable example would be those fake windows xp websites with fake malware . . . I don't believe a lot of people would fall for a phone call

j0h

Serg, I know ppl who have fallen for it

user139252

fortune | cowsay?

j0h

4:27 PM

some one calls, and says: your pc is sending out malicious traffic. you need this to fix it

I have gotten that phone call

Ronnie Marlow

I agree with their @Serg . But you know that would be an interesting video to watch on social engineering.

kos

@j0h You can search the APT cache for files using apt-file

hg8

@HeatherBrown
_______________________________________
/ You have an ability to sense and know \
\ higher truth. /
---------------------------------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||

user139252

That is actually pretty applicable. Neat.

Ronnie Marlow

I agree with their @Serg . But you know that would be an interesting video to watch on social engineering.

hg8

4:29 PM

That's a broken cow

user139252

 ________________________________________
< Avoid gunfire in the bathroom tonight. >
 ----------------------------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

hg8

How do you format it properly?

j0h

@kos apt-cache search

Serg

@HeatherBrown I have fortune | cowsay open on one of my 14.04 PCs at home every time I launch terminal. Pretty fun thing . . .

user136984

@Serg: Next time one of those scammers calls me up and try to get access to my system I'm going to give them the details to my honeypot! >:)

Serg

4:30 PM

Also, there's a variety of cows, too

Ronnie Marlow

I got a few questions for everyone. Has anyone meet mark shuttleworth., yeat

j0h

and still I dont know what it is, or where the library comes from

Serg

@ParanoidPanda Hehe, you have a honeypot of malware ?

user136984

@Serg: Well, I'm in the process of setting up a honeypot anyway.

j0h

when I get scam calls, I give them the number of some other scam caller that has previously called, as a better number to contact me at.

or I try to find thier ISP and report abuse

Ronnie Marlow

4:32 PM

I got a few questions for everyone. Has anyone meet mark shuttleworth., yeat

user136984

@hg8:

j0h

I went to lunch with Linus in 2010

kos

@j0h apt-cache looks for packages, apt-file looks for files in packages; I guess you want the second

user136984

user136984

@hg8: That deals with the formatting.

j0h

4:34 PM

apt-file: command not found

hg8

@ParanoidPanda Thanks but where did you got that ?

Ronnie Marlow

cool, that must of have been an honor @j0h

user136984

If you put a cow in the box it should appear next to "upload..." and "send".

j0h

it was at a boston linuxcon. honestly, i had way more fun with the Fedora Dev team

user136984

@j0h: You will need to install that.

user136984

4:35 PM

apt-file

j0h

yeah, Im on it thnx KOS

kos

@j0h Yeah, you need to install it, however I quickly search on mine, you probably want this package: wx3.0-headers

Ronnie Marlow

really amazing. Fedora Dev Team @j0h

j0h

Ill give that try.

Ronnie Marlow

Ok. What does everybody think about the Ubuntu Software Store? Because it leaving us.

j0h

4:42 PM

@RonnieMarlow aw man,... iit only took 5 years for me to warm up to the idea of having it.

Ronnie Marlow

I know that we had it for 5 years or so. But I have enjoyed fully. Easy installation and easy guide for new users and current users.

j0h

I think if ubuntu had greater availability on phones, the store, might have been a bigger hit.

Or, like an ubuntu gift card.

they put the sort on the OS, but didnt really market it elsewhere from what I saw

Ronnie Marlow

That is a fact on my thought of it. Because every system on the globe has a main store that guides them to new software and games and much more. Google Play & Mac Store :)

j0h

Im all for developers getting paid. That has been a difficult thing to address in the linux community. The dynamic of $$$

@RonnieMarlow Yes, thats right.

nick

consultancy is how you get paid :)

j0h

4:46 PM

it is

Ronnie Marlow

We are the leader's of software of generating it to the public and getting some pay for are fine work we do. Like for instance like flappy bird, Jet Pack and much more.

j0h

Licensing is the issue, that needs to get cracked. how to make a profitable license that serves the FOSS/GNU community, while allowing businesses to be profitable.

Ronnie Marlow

True. I agree with @j0h

Byte Commander

3

A: Format usb and confirm all zeros

My suggest would be hexdump. It displays the content of any file or device in hexadecimal format as rows of 16 byte, but if two subsequential lines are equal, it omits them. Here's an example output of the 512 MB file virtualdevice which is filled with zeroes only on the current directory of my ...

Adding times for the optimized solution by @muru in a minute. It seems to be very fast though!

Seth

Am I the only one that thinks the author of this article doesn't really understand what he is writing about?

Serg

5:00 PM

Q: Secure deletion of digital data ensures that the data cannot be recovered. Which of the following is securely deleting digital data most like?

Placing documents in a wastebasket

Obscuring documents with a magic marker

Shredding documents in a shredder

What kind of choices are those oO ???

Also . . . is it me or the grammar in the question is really off ?

Ronnie Marlow

3

Serg

I think their quiz has done goofed

Ronnie Marlow

Yeah

Terrance

3 to me would be the most likely answer.

Serg

It's actually the right answer . . .but with the video, they use an actual , physical shredder . The question asks for digital data . . . so . . . .

Terrance

5:05 PM

Yes, but it asks what "securely deleting digital data" is most like.

Serg

Oh . . . it asks "most similar to " ?

Terrance

Yep

Serg

Duuuuuh, they couldn't make it any easier ?

I mean clearer to understand

Terrance

They love cryptic questions! Try the Apple certification test. Your brain will explode!

user136984

Is anyone here running Ubuntu GNOME 15.10 with GNOME 3.16?

Terrance

5:08 PM

Not me.

Serg

@ParanoidPanda I've Ubuntu 15.10 in VM but not gnome . . . what's up ?

edward torvalds

how can I put shortcut to a mount point in nautilus side panel?

user136984

Oh, I'm just about to post a Q&A on how to install additional language packs on Ubuntu GNOME 15.10, but I am not sure if the feature is in GNOME 3.16 or 3.18.

Serg

Please note that you will not be able to complete this section of the training by clicking on the acceptance statement tick-box until you review the content at the URL.

You will not be able to ?

user136984

Well, I know it's in the latter, but I don't know about the first.

Serg

5:11 PM

Was someone drunk when writing these things ?

muru

@ByteCommander you mean grep -qz . ./virtualdevice?

kos

@ByteCommander How did you test? I get this (everything cached in a tmpfs):

muru

@Seth no, that was seen as a hatchet job by many people

kos

kos (old) run 1
dd if=/dev/zero:    0:02.43    0.36    1.86
kos (old) run 2
dd if=/dev/zero:    0:01.89    0.26    1.44
kos (old) run 3
dd if=/dev/zero:    0:02.39    0.39    1.82
kos run 1
cmp /dev/zero /media/tmpfs/file.dd:    0:02.32    1.96    0.35
kos run 2
cmp /dev/zero /media/tmpfs/file.dd:    0:02.26    1.88    0.38
kos run 3
cmp /dev/zero /media/tmpfs/file.dd:    0:02.32    1.95    0.36
muru run 1
grep -zq . /media/tmpfs/file.dd:    0:00.97    0.83    0.13
muru run 2
grep -zq . /media/tmpfs/file.dd:    0:01.49    1.26    0.22

@muru Also ^^

muru

Plots, my friends, plots

Test for a few sizes and plot the times against each other

That will reveal trends (if any), and make things clearer

kos

5:15 PM

@muru Ok. I think uncached only makes sense enough, since anyway one is IO bound in uncached

muru

Me?

@Seth meet friends in lwn.net/Articles/663338

@kos Store the whole thing in a tmpfs filesystem

Take the cache out of the equation

kos

@muru I can't speak, I meant cached. Yes that's what I did, I don't think reading from the drive makes sense

Yours is clearly the fastest already, but graphs are fun!

Byte Commander

I made my final edit: askubuntu.com/a/699184/367990

No chance I'm going to touch that monstrous answer again or even making graphs for it! :P

muru

@ByteCommander Now we need to experiment with block sizes for dd

bs=1K, bs=1M, bs=100M

Byte Commander

@muru >:P

@muru's grep solution is the fastest, my hexdump and @kos' cmp are about equal. As long as you keep your fingers away from dd everything is fine. Basta!

If anybody of you wants to invest more time and do the tests in a tempfs only and with improved dd block sizes, you can do and if you tell me I can edit it in - but I don't continue myself from here on.

kos

5:24 PM

@ByteCommander I'm making a graph. Mine's faster!

muru

@kos how about it? Trying different block sizes for dd? I think bs of 1M or 10M should easily make it comparable to directly reading

kos

Even with dd!

We're such nerds.

@muru So everything using pipes?

muru

Yep..

Terrance

@kos Hey! I resemble that nerd remark! :P

muru

*resent?

Terrance

5:26 PM

Nope, I resemble it! I'll admit, I am a big nerd. :)

kos

Ok. If it's quick I'll make both at this point

@Terrance Yep :D

RPi Awesomeness

Ugh. Gosh dang Comcast internet

Serg

OK, security training completed. Yay

Byte Commander

My keyboard will soon look like this if I go on writing such crazily enormous answers... :-P

Serg

Image not found . . . you mean your keyboard won't be found as well ?

Byte Commander

5:32 PM

@Serg Re-uploaded it.

And I'm getting votes, but today's maximum is already reached! :-/

Guys, please upvote this answer tomorrow! ;-)

Terrance

That's what my son's keyboard looks like after he plays online steam games! :)

Byte Commander

Uninstalling Ubuntu 12.04 from Widows 10? o.O askubuntu.com/questions/699232/…

That could become a game or tv series title...

Serg

@ByteCommander that dude is doing Wubi . . . AFAIK it's not recommended to be used anymore

RPi Awesomeness

^ it hasn't been supported since 12.04 IIRC

And definitely not for more than Win 7

Byte Commander

@Serg No, but I was laughing about the "widows"...

user136984

5:37 PM

By the way, why are people still running 12.04?

user136984

Ubuntu has changed a lot since then.

RPi Awesomeness

Because it's still technically supported

LTS release, supported until 2017

Serg

Ooooo, the grammar mistake, epiphany moment reached

@ParanoidPanda because it's LTS and because YOLO

user136984

@Serg: YOLO?

Byte Commander

@Serg Actually that's spelling and not grammar, but I think you got it anyway! ;)

(I know I'm nitpicking.)

Terrance

5:41 PM

You Only Live Once

user136984

@Terrance: That statement is incompatible with my beliefs, so is the statement "You Live More Than Once". :P

Terrance

@ParanoidPanda =)

Serg

@ParanoidPanda well, at least now you know what's all that young people are talking about when they say YOLO

Wait a second . . young people ?

I think I just shot myself in the foot there . . . I'm only 25 . . .ugh . . .saying "young people" seems odd . . .

user136984

@RPiAwesomeness: I don't think it really should carry on until 2017...

user136984

@Serg: You're getting old! :P

Byte Commander

5:45 PM

@Serg I'm only 19 and I even started to rant about them some years ago! What's that then? o.O

@A.B. Bounty of +100 crying for your apt-magic! askubuntu.com/q/311911/367990

user136984

@Rinzwind: Oh dear... I've even downloaded my favourite BABYMETAL songs so I can listen to them without the need for an internet connection! :D

Serg

Speaking of babymetal . . . navigates to youtube

user136984

@A.B.: They've added in a built-in language packs option now by the way!

user136984

:)

Oli

Is Launchpad broken? Last two add-apt-ppa's have failed.

user136984

5:50 PM

@Serg: You too? :D

user136984

@Serg: Do you like the song and video called MEGITSUNE?

user136984

I think that's their best one so far! :)

Serg

@ParanoidPanda I haven't listened to them that much, so need to listen a bit more for final judgement

user136984

@Serg: Look at this one:

user136984

BABYMETAL - メギツネ - MEGITSUNE (OFFICIAL)

►

user136984

5:52 PM

They are so cute in that video! :D

user136984

@ByteCommander: What do you think of them? :)

cl-netbox

@ParanoidPanda : here are the first 2 upvotes for your Q+A ! :)

user136984

@cl-netbox: Thanks! :)

cl-netbox

@ParanoidPanda nice graphics ! :)

kos

Ok, here's using pipes for comparison. WIthout pipes another day, this whole thing is a bit too consuming:

kos
#########################################
round #1  |  0:02.42  |  0.94  |  0.00  |
round #2  |  0:03.01  |  1.19  |  0.00  |
round #3  |  0:02.60  |  1.06  |  0.00  |

muru
#########################################
round #1  |  0:01.65  |  0.67  |  0.00  |
round #2  |  0:01.88  |  0.72  |  0.00  |
round #3  |  0:01.89  |  0.72  |  0.00  |

Byte Commander
#########################################
round #1  |  0:04.43  |  1.42  |  0.00  |
round #2  |  0:04.40  |  1.42  |  0.00  |
round #3  |  0:03.11  |  1.12  |  0.00  |

@ByteCommander @muru

user136984

5:55 PM

@Terrance: Have you seen BABYMETAL by the way?

Terrance

@ParanoidPanda Nope, can't say that I have.

kos

(in order Real, Sys, User)

Byte Commander

@kos As I said,I don't really care any more, at least not today.

Terrance

@ParanoidPanda But I will check it out. :)